Receiving sheet
This is a division of application Ser. No. 293,160, filed Sept. 28, 1972; now U.S. Pat. No. 3,880,656; Issued on: Apr. 29, 1975. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a novel color forming electrophotographic method utilizing a toner for electrostatic image containing a color forming agent (A) and a photoconductive photosensitive member or an image receiving sheet containing a color forming agent (B), and further to a particular electrophotographic material used therefor. 
     2. Description of the Prior Art 
     Heretofore, there have been known various electrophotographic processes such as those disclosed in U.S. Pat. No. 2,297,691, Japanese Patent Publication No. 23910/1967 and Japanese Patent Publication No. 24748/1968. In general, these electrophotographic processes comprise utilizing a photoconductive material, forming electric latent images on a photosensitive member, developing the latent images with a toner, if desired, transferring the developed image to an image receiving sheet such as paper and fixing the transferred image by heating or with solvent vapor. 
     It is widely known to use, as a developing toner, finely divided particles of 1 - 20 microns in diameter composed of a coloring pigment such as carbon black dispersed in a binder resin such as styrene resin. Such a toner is usually mixed with a carrier material such as glass beads, iron powder, fur and the like, or dispersed in an insulating liquid, and then attracted to or repulsed by the electrostatic latent image to visualize the negative or positive electric image. 
     The above-mentioned prior art has the following two problems. One is smudging during manufacturing and development since the toner is finely divided black powder. Such finely divided toner is so light that the toner is easily blown up to dirty remarkably hands, feet and clothes as well as room, and further to cause dust pollution outdoors. Dry toner is particularly of high contrast and gives images of high quality, but this dirt problem reduces the usefulness of dry toner. 
     The other is concerned with fixation. In general, toner is fixed by heating, but when a switch is turned on and then immediately the reproduction operation starts, fixation of the resulting image is incomplete and when rubbed, the toner is easily removed. Thus, the fixed portion is preliminarily heated and brought to a sufficient temperature, and then the reproduction operation can start. Particularly, a necessary preliminary heating time is usually 5 - 10 minutes for dry reproduction machine, and when once the machine is switched on, the fixing device should be kept at a constant temperature until the business time is finished. 
     As an electrophotographic method using a color forming system, there may be mentioned that disclosed in Japanese Patent Publication No. 15912/1966 which comprises covering a diazonium compound with wax and the like and combining with a paper coated with a coupler, that disclosed in Japanese Patent Publication No. 989/1967 and Japanese Patent Publication No. 3837/1970 which comprises using a volatile first chemical material as toner and a second chemical material (metal salt) as a reproduction sheet to form a colored image. However, when a diazonium compound is used as toner, there is disadvantageously a danger of explosion during pulverizing procedure and further and alkali treatment is necessary upon forming color, and therefore, it is not practical. Furthermore, in a system using a metal salt it is difficult to obtain clear and sharp color. 
     SUMMARY OF THE INVENTION 
     An object of this invention is to provide an electrophotographic method which can solve the above-mentioned drawbacks of prior art and in which a toner is colorless or of light color and a completely fixed image can be obtained without any waiting time. 
     Another object of this invention is to provide a novel multicolor electrophotographic method comprising forming an image on an image receiving sheet containing a color forming agent (B) infra by using a toner for electrostatic image containing a color forming agent (A) infra and applying a color forming treatment to form a visible image. 
     A further object of this invention is to provide a colorless or light color toner for electrostatic image containing a color forming agent (A) infra which can form color by heating together with a color forming agent (B) infra. 
     Still another object of this invention is to provide an electrophotographic photosensitive member containing a color forming agent (B) infra capable of forming color by reacting with a color forming agent (A) infra contained in a toner for electrostatic image. 
     A still further object of this invention is to provide an image receiving sheet containing a color forming agent (B) infra used for transferring an image formed by a toner for electrostatic image containing a color forming agent (A) infra. 
     Still another object of this invention is to provide an electrostatic transferring paper containing a color forming agent (B) infra. 
     According to this invention, there is provided an electrophotographic method which comprises developing an electric latent image formed on a photosensitive member comprising a photoconductive material and containing a color forming agent (B) in a surface for forming a visible image with a charged toner particle containing a color forming agent (A), and heating to cause a thermal color forming reaction between the color forming agent (A) in the toner and the color forming agent (B) in the photosensitive member resulting information of a colored fixed image on the photosensitive member, the color forming agent (A) being selected from the group consisting of 
     1. diarylphthalides, 
     2. leuco auramines, 
     3. acryl auramines, 
     4. α, β - unsaturated arylketones, 
     5. basic monoazo dyestuff, 
     6. rohdamine B lactams, 
     7. polyarylcarbinols, 
     8. benzoindolino spiropyranes, 
     9. phthalans, and 
     10. spirophthalans, 
     and the color forming agent (B) being selected from the group consisting of 
     1. polymer of phenol and aldehyde, 
     2. polymer of phenol and acetylene, 
     3. rosin modified maleic acid resin, 
     4. hydrolyzed product of copolymer of styrene and maleinic anhydride, 
     5. hydrolyzed product of polymer of carboxy polyethylene, 
     6. hydrolyzed product of copolymer of vinyl methyl ether and maleic anhydride, 
     7. hydrolyzed product of copolymer of ethylene and maleic anhydride, 
     8. Japanese acid clay, 
     9. bentonite, 
     10. diatomaceous earth, 
     11. bisphenol compounds containing carboxyl radical in a molecule, 
     12. polymers of bisphenol compounds containing carboxyl radical in a molecule, and 
     13. phenolic material. 
     According to another aspect of this invention, there is provided an electrophotographic method as mentioned above in which the toner particle contains the color forming agent (A) and a color forming auxiliary agent having a melting point ranging from 40° to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. For the purpose of this invention the expression &#34;solid plasticizer&#34; as employed herein, means diphenyl phthalate, dicyclohexyl phthalate, ethylene glycol, dibenzoate and dimethyl isophthalate. When any of the recording papers, toner particles, photosensitive members, electrostatic recording layers or image receiving sheets is employed with a color forming agent and a color forming auxiliary agent, the solid plasticizer, when employed, is the color forming auxiliary agent. 
     According to a further aspect of this invention, there is provided an electrophotographic method as mentioned above in which the visible image forming surface of the photosensitive member contains the color forming agent (B) and a color forming auxiliary agent having a melting point ranging from 40° to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. 
     According to still another aspect of this invention, there is provided an electrophotographic method which comprises developing an electric latent image formed on a photosensitive member comprising a photoconductive material with a charged toner particles containing a color forming agent (A), transferring the resulting toner image to an image receiving sheet containing a color forming agent (B), and heating to cause a thermal color forming reaction between the color forming agent (A) in the toner and the color forming agent (B) in the photosensitive member resulting in formation of a colored fixed image on the image receiving sheet. 
     According to a still further aspect of this invention, there is provided an electrophotographic method as mentioned above in which the toner particle contains the color forming agent (A) and a color forming auxiliary agent having a melting point ranging from 40°-to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. 
     According to still another object of this invention, there is provided an electrophotographic method as mentioned above in which the visable image forming the surface of the photosensitive member contains the color forming agent (B) and a color forming auxiliary agent having a melting point ranging from 40° to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. 
     According to a still further aspect of this invention, there is provided an electrostatic recording method which comprises developing an electric latent image formed on an electrostatic recording paper containing a color forming agent (B) in the visible image forming surface with a charged toner particle containing a color forming surface with a charged toner particle containing a color forming agent (A), and heating to cause a thermal color forming reaction the color forming agent (A) in the toner and the color forming agent (B) in the electrostatic recording paper resulting in formation of a color fixed image. 
     According to a still another aspect of this invention, there is provided an electrostatic recording method as mentioned above in which the toner particle contains the color forming agent (A) and a color forming auxiliary agent having a melting point ranging from 40° to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. 
     According to a still further apect of this invention, there is provided an electrostatic recording method as mentioned above in which the visible image forming surface of the photosensitive member contains the color forming gent (B) and a color forming auxiliary agent having a melting point ranging from 40° to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. 
     According to still another aspect of this invention, there is provided a recording method which comprises closely contacting a master sheet having a toner image containing a color forming agent (A) with a visible image forming surface containing a color forming agent (B) of an image receiving sheet and heating to cause a thermal color forming reaction between the color forming agent (A) and the color forming agent (B) resulting in a visible image. 
     According to a still further aspect of this invention, there is provided a recording method as mentioned above in which the toner image contains the color forming agent (A) and a color forming auxiliary agent having a melting point ranging from 4°  to 130° C. selected from the group consisting of fatty acid. fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. 
     According to still another aspect of this invenion, there is provided a recording method as mentioned above in which the visible image forming surface of an image receiving sheet contains the color forming agent (B) and a color forming auxiliary agent having a melting point ranging from 40° to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. 
     According to a still further aspect of this invention there is provided a toner for electrostatic image which comprises containing in a binder resin a color forming agent (A) selected from the group consisting of 
     1. diarylphthalides, 
     2. leuco auramines, 
     3. acryl auramines, 
     4. α,β-unsaturated arylketones, 
     5. basic monoazo dyestuff, 
     6. rohdamine B lactams, 
     7. polyarylcarbinols, 
     8. benzoindolino spiropyranes, 
     9. phthalans, and 
     10. spirophthalans. 
     According to still another aspect of this invention, there is provided a toner for electrostatic image as mentioned above in which the binder resin contains the color forming agent (A) and a color forming auxiliary agent having a melting point ranging from 40° to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. 
     According to a still further aspect of this invention, there is provided an electrophotographic photosensitive member which comprises a photoconductive material and a visible image forming surface of the photosensitive member containing a color forming agent (B) selected from the gorup consisting of 
     1. polymer of phenol and aldehyde, 
     2. polymer of phenol and acetylene, 
     3. rosin modified maleic acid resin, 
     4. hydrolyzed product of copolymer of styrene and maleic anhydride, 
     5. hydrolyzed product of polymer of carboxy polyethylene, 
     6. hydrolyzed product of copolymer of vinyl methyl ether and maleic anhydride, 
     7. hydrolyzed product of copolymer of ethylene and maleic anhydride, 
     8. Japanese acid clay, 
     9. bentonite, 
     10. diatomaceous earth, 
     11. bisphenol compounds containing carboxyl radical in a molecule, 
     12. polymers of bisphenol compounds contaning carboxyl radical in a molecule, and 
     13. phenolic material. 
     According to still another aspect of this invention, there is provided an electrophotographic photosensitive member as mentioned above in which the visible image forming surface of the photosensitive member contains the color forming agent (B) and a color forming auxiliary agent having a melting point ranging from 40° to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer, 
     According to a still further aspect of this invention there is provided an image receiving sheet which comprises a visible image forming surface containing a color forming agent (B) selected from the group consisting of 
     1. polymer of phenol and aldehyde, 
     2. polymer of phenol and acetylene, 
     3rosin modified maleic acid resin, 
     4. hydrolyzed product of copolymer of styrene and maleic anhydride, 
     5. hydrolyzed product of polymer of carboxy polyethylene, 
     6. hydrolyzed product of copolymer of vinyl methyl ether and maleic anhydride, 
     7. hydrolyzed product of copolymer of ethylene and maleic anhydride, 
     8. Japanese acid clay, 
     9. bentonite, 
     10. diatomaceous earth, 
     11. bisphenol compounds containing carboxyl radical in a molecule, 
     12. polymers of bisphenol compounds contaning carboxyl radical in a molecule, and 
     13. phenolic material. 
     According to still another aspect of this invention, there is provided an image receiving sheet as mentioned above in which the visible image forming surface contains the color forming agent (B) and a color forming auxiliary agent having a melting point ranging from 40° to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. 
     According to a still further aspect of this invention, there is provided an electrostatic recording paper which comprises a support layer and an electrostatic recording layer overlaying the support layer and containing a color forming agent (B) selected from the group consisting of 
     1. polymer of phenol and aldehyde, 
     2. polymer of phenol and acetylene, 
     3. rosin modified maleic acid resin, 
     4. hydrolyzed product of copolymer of styrene and maleic anhydride, 
     5. hydrolyzed product of polymer of carboxy polyethylene, 
     6. hydrolyzed product of copolymer of vinyl methyl ether and maleic anhydride, 
     7. hydrolyzed product of copolymer of ethylene and maleic anhydride, 
     8. Japanese acid clay, 
     9.bentonite, 
     10. diatomaceous earth, 
     11. bisphenol compounds containing carboxyl radical in a molecule, 
     12. polymers of bisphenol compounds containings carboxyl radical in a molecule, and 
     13. phenolic material. 
     According to still another aspect of this invention there is provided an electrostatic recording paper as mentioned above in which the electrostatic recording layer contains the color forming agent (B) and a color forming auxiliary agent having a melting point ranging from 40° to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Fig. 1 shows diagrammatically a conventional fixing procedure 
     Fig. 2 shown diagrammatically a color forming and fixing procedure according to the present invention; 
     FIG. 3 shows a fixing apparatus; 
     FIG. 4 shows diagrammatically a cross sectional view of a master sheet according to the present invention; 
     FIG. 5 shows diagrammatically a cross sectional view of a printing member used in the present invention; 
     FIG. 6 shows diagrammatically a procedure for reproducing an image by using a master sheet of FIG. 4 and a print member of FIG. 5; and 
     FIG. 7 shows diagrammatically a reproduction obtained in FIG. 6. 
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The color forming agent (A) used in the present invention is basic material having a color forming group. Representative color forming agents (A) are shown below. 
     (1) Diaryl phthalides: 
     3,3-bis(p-dimethylaminophenyl)-6-dimethylamino phthalide (Crystal Violet Lactone), 
     3,3-bis(p-dimethylaminophenyl)-phthalide (Malachite Green Lactone) and the like. 
     (2) Leuco auramines; 
     N - halophenyl derivatives, 
     N - alkylhalophenyl derivatives, 
     N - (2,5- dichlorophenyl) leuco auramine, and the like. 
     (3) Acryl auramines; 
     N - benzoyl auramine, 
     N - acetyl auramine, and the like. 
     (4) α,β- unsaturated arylketones: 
     Dianisylidene acetone, 
     Dibenzylidene acetone, 
     Anisylidene acetone, and the like. 
     (5) Basic monoazo dye: 
     p - dimethylaminoazobenzene - O - carboxylic acid (Methyl Red), 
     4 - aminoazobenzene (Oil Yellow - AAB), 
     4 - phenylazo - 1 - naphthylamine, and the like. 
     (6) Rohdamine B lactams: 
     N (p-nitrophenyl) - rohdamine B lactam, 
     3,6&#39;- diamino rohdamine B lactam, 
     3,6&#39;- diethylamino rohdamine B lactam, 
     3,6&#39;- dimethylamino rohdamine B lactam, and the like. 
     (7) Polyaryl carbinols 
     Bis - (p-dimethylamino phenyl)methanol (Michler&#39;s hydrol), 
     Crystal Violet Carbinol, 
     Malachite Green Carbinol, and the like. 
     (8) Benzoindolino spiropyrans: 
     8&#39;- methoxy benzoindolino spiropyran, 
     4,7,8&#39;- trimethoxy benzoidolino spiropyran, 
     6&#39;- chloro - 8&#39;- methoxy benzoindolino spiropyran and the like. 
     (9) Phthalans: 
     1,1 - bis (p-aminophenyl) phthalan, 
     1,1 - bis (p-benzylaminophenyl) phthalan, 
     1,1 - bis (p-dibenzylamino phenyl) phthalan, 
     1,1 - bis (p-N-methylanilino phenyl) phthalan, and the like. 
     (10) Spirophthalans: 
     6,6&#39;- diamino spiro (phthalan - 1,9&#39;- xanthen) 
     6,6&#39;- diethylaminospiro (phthalan - 1,9&#39;- xanthen) 
     6,6&#39;- dimethylamino spiro (phthalan - 1,9&#39;- xanthen) and the like. 
     These color forming agents (A) can react with the color forming agent (B) as mentioned above to form color. These materials are disclosed in Japanese pat. publication Nos. 10788/1965, 9309/1965, 9310/1965, 3257/1967, 9071/1969, 10318/1969 and 11634/1969. 
     Among the color forming agents (B) used in this invention, examples of (11) bisphenol compounds containing carboxyl radical in a molecule are: ##STR1## 
     Further, examples of (12) polymers of bisphenol compounds containing carboxyl radical in a molecule are: ##STR2## (softening point 95°-105° C, average degree of polymerization 30-35) and C., ##STR3## (Softening point 96°- 109° C., overage degree of polymerization 40 - 45). These bisphenol compounds are preferable color forming agents (B). 
     Furthermore, examples of (B) phenolic material are shown below: 
     4 - teritary - butyl phenol, 
     4 - β - teritary - amyl phenol, 
     4 - phenyl phenol, 
     4,4&#39; - isopropylidine - bis (2-chloro phenol), 
     4,4&#39; - isopropylidene - bis - (2-methyl phenol), 
     4,4&#39; - isopropylidene - bis - (2-tertiary butyl phenol), 
     4,4&#39; - secondary - butylidene - bis -(2-methyl phenol), 
     2,2&#39;- dihydroxy diphenyl, 
     4,4&#39; - secondary - butylidene diphenol, 
     4 - tertiary - octyl catechol, 
     4 - hydroxy aceto phenone, 
     methyl - 4 - hydroxy benzoate, 
     4 - hydroxy diphenoxide, 
     α - naphthol, 
     β - naphthol, 
     4 - hydroxy diphenyl oxide, 
     2,2&#39; -methylene - bis - (4-chloro phenol), 
     2,2&#39; - methylene - bis - (4-methyl - 6-tertiary-butyl phenol, 
     4,4&#39; - isopropylidene - bis (2,6-dibromo phenol), 
     4,4&#39; - isopropylidene - bis - (2,6-dimethyl phenol), 
     4,4&#39; - cyclohexylidene diphenol, 
     4,4&#39; - cyclohexylidene - bis - (2-methyl phenol). 
     The reaction of the color forming agent (A) and the color forming agent (B), a kind of base - acid reaction, according to the present invention, is illustrated by using a combination of malachite green lactone and phenolic resin as an example. ##STR4## 
     Conventional electrophotographic methods are applicable to the production of electric latent image in the present invention. For example, there may be mentioned conventional elctrophotographic methods such as the Carlson process comprising charging a whole surface of photoconductive layer composed of selenium, Cds or ZnO and then projecting a light image to form a latent image and a method disclosed in Japanese patent publication No. 23910/1967 or 24748/1968 comprising uniformly charging a photosensitive member composed of a photoconductive layer such as selenium and CdS and an insulating layer such as polyester overlying the photoconductive layer, applying corona charging simultaneously with imagewise exposure, and applying blanket exposure. 
     The latent image thus obtained may be developed by a conventional developing method such as cascade developing methods, magnetic brush developing methods, fur brush developing methods and liquied developing methods, by using a toner having a charge opposite to that of the electrostatic latent image. In some particular cases, there may be used a toner having the same charge as that of the electrostatic latent image. 
     In the electrophotographic method according to the present invention, when agent (A) alone in a form of finely divided particles, is used as a toner to form an image, the chargeability is poor and fog forms and moreover, the color forming property is poor. Furthermore, there is formed sometimes an image composed of both negative and positive images. The thermal conductivity is so low that melting by heating is not sufficient and color forming efficiency is poor and the density of the resulting image is low. High fixing temperature is necessary and further, the color forming dye directly contacts atmosphere to cause deterioration of the color forming agent (A) due to moisture and oxygen. 
     The present inventors have successfully eliminated such disadvantages by dispersing the color forming agent (A) in a resin of relatively low melting point such as from 70° to 130° C. which has been used as a binder resin for an electrophotographic toner, such as vinsol resin, cumarone resin, polystyrene, polyvinyl acetate, polyvinyl chloride, polyethylene, polyacrylic acid ester, polyvinyl acetal, polyvinylidene chloride, polyethylene terephthalate, alkyd resin, polyamide resin, epoxy resin, polypropylene, mixtures thereof, and copolymers thereof, the resulting toner for development has a highly improved chargeability. 
     For the purpose of improving further color forming efficiency and low temperature fixing efficiency, the color forming agent (A) and the binder resin are sufficiently melted at a certain temperature to cause a reaction with the color forming agent (B) on the photosensitive member or the transferring support. It has been now found that addition of a color forming auxiliary agent capable of low temperature fixation and improving the image density to attain the purpose. 
     The color forming auxiliary agent has a melting point ranging from 40° to 130° C. selected from the group consisting of fatty acid, fatty acid metal salt, fatty acid ester, fatty acid amide, fatty acid anilide and solid plasticizer. These color forming auxiliary agent are mutually soluble with a binder resin, a color forming agent (A) and a color forming agent (B). 
     Representative color forming auxiliary agents are as shown below. (1) Fatty acids compounds, for example, 
     
         ______________________________________                                    
Lauric acid          (44° C.)                                      
Tridecylic acid      (45.5° C.)                                    
Myristic acid        (58° C.)                                      
Pentadecylic acid    (53°- 54° C.)                          
Palmitic acid        (63°- 64° C.)                          
Heptadecylic acid    (60°- 61° C.)                          
Stearic acid         (71.5°- 72° C.)                        
Nonadecanoic acid    (68.7° C.)                                    
Arachic acid         (77° C.)                                      
Behenic acid         (81°- 82° C.)                          
Lignoceric acid      (83.5° C.)                                    
Cerotic acid         (87.9° C.)                                    
Heptacosanoic acid   (82° C.)                                      
Montanic acid        (89.3° C.)                                    
Melissic acid        (93.5°- 94° C.)                        
Lacceric acid        (95°- 96° C.)                          
and the like.                                                             
______________________________________                                    
 
    
     The numbers in the parenthese are melting points. The preferable color forming auxiliary agents are fatty acids containing 12 or more carbon atom and having melting points ranging from 40° to 100° C. (2) Metallic salts of fatty acids having melting points ranging from 40° to 130° C. are shown by the following general formula: 
     
         (RCOO).sub.n M 
    
     where n =1 - 3; M is Be, Mg, Ba, Zn, Cd, Hg, Al, Tl, Pb and the like; R is an alkyl radical. Representative examples are as follows: 
     
         ______________________________________                                    
Lead caproate      (m.p. 73 - 74° C.)                              
Lead enanthate     (m.p. 78° C.)                                   
Lead caprylate     (m.p. 83°- 84° C.)                       
Lead pelargonate   (m.p. 94°- 95° C.)                       
Lead caprate       (m.p. 100° C.)                                  
Lead laurate       (m.p. 106° C.)                                  
Lead myristate     (m.p. 108.6° C.)                                
Lead palmitate     (m.p. 112° C.)                                  
Lead stearate      (m.p. 116°- 125° C.)                     
Lead tridecylate   (m.p. 128° C.)                                  
Aluminum stearate  (m.p. 105° C.)                                  
Beryllium stearate (m.p. 45° C.)                                   
______________________________________                                    
 
    
     (3) Fatty acid derivatives having melting points ranging from 40° to 130° C., which are represented by the following formula: ##STR5## where R is alkyl; R&#39; is alkyl or aryl. Representative examples are as follows: 
     
         ______________________________________                                    
(i)  Methyl esters:                                                       
     Methyl arachinate (m.p. 46°- 47° C.)                   
     Methyl behenate   (m.p. 54° C.)                               
     Methyl lignocerate                                                   
                       (m.p. 56.7°- 57° C.)                 
     Methyl cerotinate (m.p. 63° C.)                               
     Methyl heptacosanate                                                 
                       (m.p. 64° C.)                               
     Methyl montanate  (m.p. 65.5° C.)                             
     Methyl melissinate                                                   
                       (m.p. 71.5° C.)                             
(ii) Ethyl esters:                                                        
     Ethyl arachinate  (m.p. 42° C.)                               
     Ethyl behenate    (m.p. 50° C.)                               
     Ethyl lignocerate (m.p. 56.7°- 57° C.)                 
     Ethyl cerotinate  (m.p. 60° C.)                               
     Ethyl montanate   (m.p. 64°- 65° C.)                   
     Ethyl melissinate (m.p. 70.5° C.)                             
     Ethyl laccerate   (m.p. 76° C.)                               
(iii)                                                                     
     Phenyl esters:                                                       
     Phenyl arachinate (m.p. 58.5° C.)                             
     Phenyl palmitinate                                                   
                       (m.p. 45° C.)                               
(iv) Glycohol esters:                                                     
     Glycohol myristate                                                   
                       (m.p. 64° C.)                               
     Glycohol palmitinate                                                 
                       (m.p. 51 5° C.)                             
     Glycohol stearate (m.p. 58°- 75° C.)                   
(v)  Glycerol esters                                                      
     Glycerol laurate  (m.p. 63° C.)                               
     Glycerol myristate                                                   
                       (m.p. 56°- 70.5° C.)                 
     Glycerol palmitinate                                                 
                       (m.p. 34°- 77° C.)                   
     Glycerol stearate (m.p. 54°- 71° C.)                   
______________________________________                                    
 
    
     (4) Fatty acid derivatives having melting points ranging from 40° C. to 130° C., which are represented by the following formula ##STR6## where R is alkyl; R&#39; and R&#34; is H, alkyl, or aryl. Representative examples useful for this invention are as follows: 
     
         ______________________________________                                    
(i)  Amides:                                                              
     Acetic amides     (m.p. 82°- 83° C.)                   
     Propionic amide   (m.p. 81.8° C.)                             
     Butyric amide     (m.p. 115°- 116° C.)                 
     Valeric amide     (m.p. 106° C.)                              
     Caproic amide     (m.p. 101° C.)                              
     Enantic amide     (m.p. 93°- 94° C.)                   
     Caprinic amide    (m.p. 105.9° C.)                            
     Peralgonoic amide (m.p. 98.9° C.)                             
     Undecylic amide   (m.p. 84.5°- 85.5° C.)               
     Lauric amide      (m.p. 102.4° C.)                            
     Tridecylic amide  (m.p. 100° C.)                              
     Myristic amide    (m.p. 105.1° C.)                            
     Pentadecylic amide                                                   
                       (m.p. 102° C.)                              
     Palmitic amide    (m.p. 107° C.)                              
     Heptadecylic amide                                                   
                       (m.p. 108°- 109° C.)                 
     Stearic amide     (m.p. 109.7° C.)                            
     Arachic amide     (m.p. 108° C.)                              
     Behenic amide     (m.p. 111°- 112° C.)                 
     Cerotic amide     (m.p. 109° C.)                              
     Montanic amide    (m.p. 112° C.)                              
(ii) Anilides:                                                            
     Valeric amilide   (m.p. 68° C.)                               
     Caproic anilide   (m.p. 92° C.)                               
     Caprylic anilide  (m.p. 55° C.)                               
     Peralgonoic anilide                                                  
                       (m.p. 57.5° C.)                             
     Capric anilide    (m.p. 62.5° C.)                             
     Undecylic anilide (m.p. 71° C.)                               
     Lauric anilide    (m.p. 77.2° C.)                             
     Myristic anilide  (m.p. 84° C.)                               
     Palmitic anilide  (m.p. 90.2° C.)                             
     Stearic anilide   (m.p. 94° C.)                               
     Behenic anilide   (m.p. 101°- 102° C.)                 
(iii)                                                                     
     N-Methyl amides                                                      
     Capric methyl amide                                                  
                       (m.p. 57.8° C.)                             
     Lauric methyl amide                                                  
                       (m.p. 62.4° C.)                             
     Myristic methyl amide                                                
                       (m.p. 78.4° C.)                             
     Palmitic methyl amide                                                
                       (m.p. 85.5° C.)                             
     Stearic methyl amide                                                 
                       (m.p. 92.1° C.)                             
(iv) N-Dodecylic amides                                                   
     Lauric dodecyl amide                                                 
                       (m.p. 77°- 77.5° C.)                 
     Myristic dodecyl amide                                               
                       (m.p. 84°- 85° C.)                   
     Palmitic dodecyl amide                                               
                       (m.p. 82.5°- 85° C.). - Stearic      
                       dodecyl amide (m.p. 85°- 85.5°       
______________________________________                                    
                       C.)                                                
 
    
     (5) Solid plasticizers, for example, diphenyl phthalate, dicyclohexyl phthalate, ethylene glycol dibenzoate, and dimethyl isophthalate. 
     Addition of the color forming auxiliary agent results in high color forming efficiency, good low temperature fixation, and colored image copy having sharp and sufficient density. Such improvement is considered due to that the color forming auxiliary agent melts at relatively low temperature and the color forming agent (A) and the binder resin and further the color forming agent (B) in the photosensitive member or transferring paper are mutually soluble with the color forming auxiliary agent to cause coloring and fixing at a low temperature and enhance the color forming density. 
     It has been further found from experiments shown later that the color forming auxiliary agent gives a good result when the color forming auxiliary agent is added together with the color forming agent (B) to a visible image forming surface of the electrophotographic photosensitive member or image receiving sheet. 
     The amount of the color forming auxiliary agent is usually more than 5 parts preferred with 20 - 200 parts, particularly preferred with 30 - 150 parts, per 100 parts of the color forming agent (A). 
     Now referring to FIG. 1 and FIG. 2, there is explained the difference between coloring and fixation of the present invention and fixation of conventional dry electrophotographic method. According to conventional method, a toner image 2 formed on a support 1 such as paper is already colored before heat-fixation and can be fixed to support 1 by heat-fixing at relatively high temperature. On the contrary, according to the color forming fixing method of the present invention, a color forming agent layer 4 is formed on a support 1 such as paper and a toner image 3 containing a color forming agent (A) formed on the color forming agent layer 4 is colorless or of light color. When these are heated at a relatively low temperature and melted to cause a color forming reaction with a color forming agent (B) layer 4 resulting in the colored portion 3a. As is clear from above, a conventional toner image is often removed by rubbing while a colored image according to the present invention is not removed at all by rubbing. 
     Conventional dry toner (thermoplastic resin - carbon system) is compared with the toner of the present invention (Example 1) with respect to fixing temperature by using a fixing apparatus as illustrated in FIG. 3. 
     As shown in FIG. 3, four 250W infrared heaters 5 are arranged and a conveyor 8 of 200 mm long moves at 123 mm/sec. and a transferring sheet moves thereon to form color and fix. Reference numbers 6,7,8,9 and 10 devote a heat insulating material, a gear, a wire net conveyor, a thermometer and a variable thermostat, respectively. 
     By using this fixing apparatus, each fixing temperature was measured. 
     
         ______________________________________                                    
                  Fixing temperature                                      
______________________________________                                    
Toner of the present invention                                            
                    180° C.                                        
Conventional toner  280° C.                                        
______________________________________                                    
 
    
     This result indicates that waiting time of a copier can be shortened to a great extent. 
     The following experimental examples are given for illustrating the improvement accomplished by the present invention. In the experimental examples, ingredients are mixed at the weight ratio as listed in the following tables and melted and cooled, and then pulverized by using a jet mill to form a toner of less than 20 microns in size. Ten parts by weight of the resulting toner was mixed with 90 parts by weight of iron powder of 50 microns in size, and image formation was effected by using NP 1100 Electrophotographic apparatus (manufactured by Canon Co.) and the resulting image was evaluated. 
     The evaluation of each experimental example is conducted as shown below. 
     1. State at normal temperature after mix-melting: Distinguishing solid mater and sticky semi-solid by naked eyes. 
     2. Pulverizing property: Degree of pulverizing property is designated as shown below; 
      good 
      fairly good 
     Δ somewhat bad 
     X bad 
     3. Maximum color forming density. Fog density: Reflective density is measured by MACBETH quantalog densitometer RD-100 with a red filter. 
     4. Image blur, resolving power: Evaluation of images on a transferring paper by naked eyes and the evaluation results are designated in the same way as shown in item 2 above. 
     5. Chargeability: Mixing an iron powder carrier with a sample toner and measuring polarity of charge, negative or positive. 
     6. Fixing temperature: Measured by a method as mentioned above. In the following table, &#34;D-125&#34; denotes polystyrene supplied by Esso Standard Co. (trade name, &#34;Piccolastic&#34; D-125) and &#34;CVL&#34; denotes Crystal Violet Lactone. 
     
                                           Table 1                                 
__________________________________________________________________________
Experiment                                                                
No.    1   2  3  4  5  6  7  8  9  10 11 12 13 14                         
__________________________________________________________________________
D-125  25  50                                                             
             70  85 70 70 70 70 70 70 70 70 70 70                         
       parts                                                              
Stearic             5  10 20 30 40 15 15 15 15 15                         
acid   parts                                                              
CVD    75  50                                                             
             30  15 30 30 30 30 30 5  10 20 40 60                         
       parts                                                              
State after                                                               
fusing at                                                                 
       solid                                                              
           solid                                                          
             solid                                                        
                 solid solid                                              
                          solid                                           
                             solid                                        
                                solid                                     
                                   solid                                  
                                      solid                               
                                         solid                            
                                            solid                         
                                               solid                      
room                solid                                                 
temperature                                                               
Pulverizing                                                               
       Δ                                                            
           ○                                                       
             ⊚                                             
                 ⊚                                         
                    ⊚                                      
                       ⊚                                   
                          ○                                        
                             Δ                                      
                                ×                                   
                                   ⊚                       
                                      ⊚                    
                                         ⊚                 
                                            ○                      
                                               ○                   
property                                                                  
Fusing to                                                                 
       non non                                                            
             non non                                                      
                    non                                                   
                       non                                                
                          non                                             
                             a  exist                                     
                                   none                                   
                                      none                                
                                         none                             
                                            none                          
                                               a                          
drum                         little            little                     
Charge-                                                                   
       +   +-                                                             
             -   -  -  -  -  +- +  -  -  -  -  +-                         
ability                                                                   
Fixing 300° C.                                                     
           290°                                                    
             280°                                                  
                 270°                                              
                    200°                                           
                       185°                                        
                          175°                                     
                             170°                                  
                                165°                               
                                   170°                            
                                      175°                         
                                         180°                      
                                            200°                   
                                               220°                
temperature                                                               
Maximum                                                                   
density of                                                                
       0.3 0.3                                                            
             0.2 0.2                                                      
                    0.6                                                   
                       0.8                                                
                          1.0                                             
                             1.05                                         
                                1.0                                       
                                   0.8                                    
                                      1.0                                 
                                         1.0                              
                                            1.0                           
                                               1.0                        
formed color                                                              
Density of                                                                
       0.01                                                               
           0.01                                                           
             0.01                                                         
                 0.01                                                     
                    0.02                                                  
                       0.03                                               
                          0.04                                            
                             0.05                                         
                                0.07                                      
                                   0.02                                   
                                      0.03                                
                                         0.03                             
                                            0.05                          
                                               0.08                       
fog                                                                       
Blur   exist                                                              
           exist                                                          
             none                                                         
                 none                                                     
                    none                                                  
                       none                                               
                          none                                            
                             a  exist                                     
                                   none                                   
                                      none                                
                                         none                             
                                            none                          
                                               a                          
                             little            little                     
Resolving                                                                 
       Δ                                                            
           Δ                                                        
             ○                                                     
                 ○                                                 
                    ○                                              
                       ⊚                                   
                          ⊚                                
                             ○                                     
                                ○                                  
                                   ○                               
                                      ⊚                    
                                         ⊚                 
                                            ○                      
                                               ○                   
power                                                                     
Total  Δ                                                            
           Δ                                                        
             ○                                                     
                 ○                                                 
                    ○                                              
                       ⊚                                   
                          ⊚                                
                             Δ                                      
                                Δ                                   
                                   ○                               
                                      ⊚                    
                                         ⊚                 
                                            ○                      
                                               Δ                    
evaluation                                                                
__________________________________________________________________________
 
    
     
                                           Table 2                                 
__________________________________________________________________________
Experiment                                                                
No.    15  16 17 18 19 20 21 22 23 24                                     
__________________________________________________________________________
D-125  70  70 70 70 70 70 70 70 70 70                                     
       parts                                                              
Myristic                                                                  
       5   10 20 30 40 15 15 15 15 15                                     
acid   parts                                                              
CVD    30  30 30 30 30 5  10 20 40 60                                     
       parts                                                              
State after                                                               
fusing at                                                                 
       solid                                                              
           solid                                                          
              solid                                                       
                 solid                                                    
                    solid                                                 
                       solid                                              
                          solid                                           
                             solid                                        
                                solid                                     
                                   solid                                  
room                                                                      
temperature                                                               
Pulverizing                                                               
       ⊚                                                   
           ⊚                                               
              ○                                                    
                 Δ                                                  
                    ×                                               
                       ⊚                                   
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
property                                                                  
Fusing to                                                                 
       none                                                               
           none                                                           
              none                                                        
                 a  exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   a                                      
drum             little            little                                 
Charge-                                                                   
       -   -  -  +- +  -  -  -  -  +-                                     
ability                                                                   
Fixing 210°                                                        
           205°                                                    
              190°                                                 
                 185°                                              
                    180°                                           
                       170°                                        
                          175°                                     
                             180°                                  
                                180°                               
                                   195°                            
temperature                                                               
       C   C  C  C  C  C  C  C  C  C                                      
Maximum                                                                   
density of                                                                
       0.6 0.9                                                            
              1.0                                                         
                 1.05                                                     
                    1.0                                                   
                       0.8                                                
                          1.0                                             
                             1.02                                         
                                1.0                                       
                                   1.10                                   
formed color                                                              
Density of                                                                
       0.02                                                               
           0.03                                                           
              0.03                                                        
                 0.05                                                     
                    0.17                                                  
                       0.02                                               
                          0.03                                            
                             0.03                                         
                                0.05                                      
                                   0.07                                   
fog                                                                       
Blur   none                                                               
           none                                                           
              none                                                        
                 a  exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   a                                      
                 little            little                                 
Resolving                                                                 
       ○                                                           
           ⊚                                               
              ⊚                                            
                 ○                                                 
                    ○                                              
                       ○                                           
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
power                                                                     
Total  ○                                                           
           ⊚                                               
              ⊚                                            
                 ○                                                 
                    Δ                                               
                       ○                                           
                          ⊚                                
                             ⊚                             
                                ⊚                          
                                   Δ                                
evaluation                                                                
__________________________________________________________________________
 
    
     
                                           Table 3                                 
__________________________________________________________________________
Experiment                                                                
No.    25  26 27 28 29 30 31 32 33 34                                     
__________________________________________________________________________
D-125  70  70 70 70 70 70 70 70 70 70                                     
       parts                                                              
Aluminum                                                                  
       5   10 20 30 40 15 15 15 15 15                                     
stearate                                                                  
       parts                                                              
CVL    30  30 30 30 30 5  10 20 40 60                                     
Pulverizing                                                               
       ⊚                                                   
           ⊚                                               
              ○                                                    
                 Δ                                                  
                    ×                                               
                       ⊚                                   
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
property                                                                  
Fusing to                                                                 
       none                                                               
           none                                                           
              none                                                        
                 a  exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   a                                      
drum             little            little                                 
Charge-                                                                   
       -   -  -  +- +  -  -  -  -  +-                                     
ability                                                                   
Fixing 215°                                                        
           200°                                                    
              190°                                                 
                 185°                                              
                    180°                                           
                       185°                                        
                          190°                                     
                             195°                                  
                                215°                               
                                   235°                            
temperature                                                               
       C   C  C  C  C  C  C  C  C  C                                      
Maximum                                                                   
density of                                                                
       0.58                                                               
           0.81                                                           
              1.97                                                        
                 1.00                                                     
                    1.02                                                  
                       0.79                                               
                          1.01                                            
                             1.00                                         
                                1.01                                      
                                   1.03                                   
formed color                                                              
Density of                                                                
       0.02                                                               
           0.03                                                           
              0.04                                                        
                 0.05                                                     
                    0.07                                                  
                       0.02                                               
                          0.03                                            
                             0.03                                         
                                0.05                                      
                                   0.08                                   
fog                                                                       
Blur   none                                                               
           none                                                           
              none                                                        
                 a  exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   a                                      
                 little            little                                 
Resolving                                                                 
       ○                                                           
           ⊚                                               
              ⊚                                            
                 ○                                                 
                    ○                                              
                       ○                                           
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
power                                                                     
Total  ○                                                           
           ⊚                                               
              ⊚                                            
                 Δ                                                  
                    Δ                                               
                       ○                                           
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   Δ                                
evaluation                                                                
__________________________________________________________________________
 
    
     
                                           Table 4                                 
__________________________________________________________________________
Experiment                                                                
No.    35  36 37 38 39 40 41 42 43 44 45 46 47 48                         
__________________________________________________________________________
D-125  25  50 70 85 70 70 70 70 70 70 70 70 70 70                         
       parts                                                              
           parts                                                          
              parts                                                       
                 parts                                                    
                    parts                                                 
                       parts                                              
                          parts                                           
                             parts                                        
                                parts                                     
                                   parts                                  
                                      parts                               
                                         parts                            
                                            parts                         
                                               parts                      
Lead                                                                      
Capylate            5 &#34;                                                   
                       10 &#34;                                               
                          20 &#34;                                            
                             30 &#34;                                         
                                40 &#34;                                      
                                   15 &#34;                                   
                                      15 &#34;                                
                                         15 &#34;                             
                                            15 &#34;                          
                                               15 &#34;                       
CVL    75 &#34;                                                               
           50 &#34;                                                           
              30 &#34;                                                        
                 15 &#34;                                                     
                    30 &#34;                                                  
                       30 &#34;                                               
                          30 &#34;                                            
                             30 &#34;                                         
                                30 &#34;                                      
                                   5 &#34;                                    
                                      10 &#34;                                
                                         20 &#34;                             
                                            40 &#34;                          
                                               60 &#34;                       
Pulverizing                                                               
property                                                                  
       Δ                                                            
           ○                                                       
              ⊚                                            
                 ⊚                                         
                    ⊚                                      
                       ⊚                                   
                          Δ                                         
                             ×                                      
                                ⊚                          
                                   ⊚                       
                                      ⊚                    
                                         ○                         
                                            ○                      
Fusing to                    a                 a                          
drum   none                                                               
           none                                                           
              none                                                        
                 none                                                     
                    none                                                  
                       none                                               
                          none                                            
                             little                                       
                                exist                                     
                                   none                                   
                                      none                                
                                         none                             
                                            none                          
                                               little                     
Charge-                                                                   
       +   +- -  -  -  -  -  +- +  -  -  -  -  +-                         
ability                                                                   
Fixing                                                                    
temperature                                                               
       300° C.                                                     
           290                                                            
              280                                                         
                 270                                                      
                    210                                                   
                       195                                                
                          185                                             
                             180                                          
                                175                                       
                                   180                                    
                                      185                                 
                                         190                              
                                            210                           
                                               230                        
Maximum                                                                   
density of                                                                
formed 0.27                                                               
           0.30                                                           
              0.20                                                        
                 0.25                                                     
                    0.63                                                  
                       0.87                                               
                          1.09                                            
                             1.05                                         
                                1.00                                      
                                   0.81                                   
                                      1.02                                
                                         1.05                             
                                            1.00                          
                                               1.07                       
color                                                                     
Density of                                                                
fog    0.01                                                               
           0.01                                                           
              0.01                                                        
                 0.01                                                     
                    0.02                                                  
                       0.03                                               
                          0.04                                            
                             0.04                                         
                                0.08                                      
                                   0.02                                   
                                      0.03                                
                                         0.03                             
                                            0.05                          
                                               0.08                       
Blur   exist                                                              
           exist                                                          
              none                                                        
                 none                                                     
                    none                                                  
                       none                                               
                          none                                            
                             a  exist                                     
                                   none                                   
                                      none                                
                                         none                             
                                            none                          
                                               a                          
                             little            little                     
Resolving                                                                 
       Δ                                                            
           Δ                                                        
              ○                                                    
                 ○                                                 
                    ○                                              
                       ⊚                                   
                          ⊚                                
                             ○                                     
                                ○                                  
                                   ○                               
                                      ⊚                    
                                         ⊚                 
                                            ○                      
                                               ○                   
power                                                                     
Total  Δ                                                            
           Δ                                                        
              ○                                                    
                 ○                                                 
                    ○                                              
                       ⊚                                   
                          ⊚                                
                             Δ                                      
                                Δ                                   
                                   ○                               
                                      ⊚                    
                                         ⊚                 
                                            ○                      
                                               Δ                    
evaluation                                                                
__________________________________________________________________________
 
    
     
                                           Table 5                                 
__________________________________________________________________________
Experiment                                                                
No.    49  50 51 52 53 54 55 56 57 58 59 60 61 62                         
__________________________________________________________________________
D-125  25  50 70 85 70 70 70 70 70 70 70 70 70 70                         
       parts                                                              
           parts                                                          
              parts                                                       
                 parts                                                    
                    parts                                                 
                       parts                                              
                          parts                                           
                             parts                                        
                                parts                                     
                                   parts                                  
                                      parts                               
                                         parts                            
                                            parts                         
                                               parts                      
Glycol                                                                    
stearate            5 &#34;                                                   
                       10 &#34;                                               
                          20 &#34;                                            
                             30 &#34;                                         
                                40 &#34;                                      
                                   15 &#34;                                   
                                      15 &#34;                                
                                         15 &#34;                             
                                            15 &#34;                          
                                               15 &#34;                       
CVL    75 &#34;                                                               
           50 &#34;                                                           
              30 &#34;                                                        
                 15 &#34;                                                     
                    30 &#34;                                                  
                       30 &#34;                                               
                          30 &#34;                                            
                             30 &#34;                                         
                                30 &#34;                                      
                                   5 &#34;                                    
                                      10 &#34;                                
                                         20 &#34;                             
                                            40 &#34;                          
                                               60 &#34;                       
Pulverizing                                                               
property                                                                  
       Δ                                                            
           ○                                                       
              ⊚                                            
                 ⊚                                         
                    ⊚                                      
                       ⊚                                   
                          ○                                        
                             Δ                                      
                                ×                                   
                                   ⊚                       
                                      ⊚                    
                                         ⊚                 
                                            ○                      
                                               ○                   
Fusing to                                                                 
       none                                                               
           none                                                           
              none                                                        
                 none                                                     
                    none                                                  
                       none                                               
                          none                                            
                             a  exist                                     
                                   none                                   
                                      none                                
                                         none                             
                                            none                          
                                               a                          
drum                         little            little                     
Charge-                                                                   
       +   +- -  -  -  -  +- +  -  -  -  -  -  +-                         
ability                                                                   
Fixing 300° C.                                                     
           290                                                            
              280                                                         
                 270                                                      
                    200                                                   
                       185                                                
                          175                                             
                             170                                          
                                165                                       
                                   170                                    
                                      175                                 
                                         180                              
                                            200                           
                                               220                        
temperature                                                               
Maximum                                                                   
density of                                                                
       0.32                                                               
           0.31                                                           
              0.20                                                        
                 0.21                                                     
                    0.61                                                  
                       0.83                                               
                          0.95                                            
                             1.01                                         
                                1.00                                      
                                   0.85                                   
                                      1.01                                
                                         1.01                             
                                            1.01                          
                                               1.00                       
formed                                                                    
color                                                                     
Density of                                                                
       0.01                                                               
           0.01                                                           
              0.01                                                        
                 0.01                                                     
                    0.02                                                  
                       0.03                                               
                          0.03                                            
                             0.05                                         
                                0.07                                      
                                   0.02                                   
                                      0.03                                
                                         0.05                             
                                            0.08                          
fog                                                                       
Blur   exist                                                              
           exist                                                          
              none                                                        
                 none                                                     
                    none                                                  
                       none                                               
                          none                                            
                             a  exist                                     
                                   none                                   
                                      none                                
                                         none                             
                                            none                          
                                               a                          
                             little            little                     
Resolving                                                                 
       Δ                                                            
           Δ                                                        
              ○                                                    
                 ○                                                 
                    ○                                              
                       ⊚                                   
                          ⊚                                
                             ○                                     
                                ○                                  
                                   ○                               
                                      ⊚                    
                                         ⊚                 
                                            ○                      
                                               ○                   
power                                                                     
Total  Δ                                                            
           Δ                                                        
              ○                                                    
                 ○                                                 
                    ○                                              
                       ⊚                                   
                          ⊚                                
                             Δ                                      
                                Δ                                   
                                   ○                               
                                      ⊚                    
                                         ⊚                 
                                            ○                      
                                               Δ                    
evaluation                                                                
__________________________________________________________________________
 
    
     
                                           Table 6                                 
__________________________________________________________________________
Experiment                                                                
No.    63  64 65 66 67 68 69 70 71 72                                     
__________________________________________________________________________
D-125  70  70 70 70 70 70 70 70 70 70                                     
       parts                                                              
           parts                                                          
              parts                                                       
                 parts                                                    
                    parts                                                 
                       parts                                              
                          parts                                           
                             parts                                        
                                parts                                     
                                   parts                                  
Glycol 5 &#34; 10 &#34;                                                           
              20 &#34;                                                        
                 30 &#34;                                                     
                    40 &#34;                                                  
                       15 &#34;                                               
                          15 &#34;                                            
                             15 &#34;                                         
                                15 &#34;                                      
                                   15 &#34;                                   
stearate                                                                  
CVL    30 &#34;                                                               
           30 &#34;                                                           
              30 &#34;                                                        
                 30 &#34;                                                     
                    30 &#34;                                                  
                       5 &#34;                                                
                          10 &#34;                                            
                             20 &#34;                                         
                                40 &#34;                                      
                                   60 &#34;                                   
Pulverizing                                                               
       ⊚                                                   
           ⊚                                               
              ○                                                    
                 Δ                                                  
                    ×                                               
                       ⊚                                   
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
property                                                                  
Fusing to     a                 a                                         
drum   none                                                               
           none                                                           
              none                                                        
                 little                                                   
                    exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   little                                 
Charge-                                                                   
       -   -  -  +- +  -  -  -  -  +-                                     
ability                                                                   
Fixing 205°  C.                                                    
           190                                                            
              180                                                         
                 175                                                      
                    170                                                   
                       175                                                
                          180                                             
                             185                                          
                                205                                       
                                   225                                    
temperature                                                               
Maximum                                                                   
density of                                                                
       0.60                                                               
           0.80                                                           
              1.00                                                        
                 1.05                                                     
                    1.00                                                  
                       0.80                                               
                          1.01                                            
                             1.00                                         
                                1.00                                      
                                   1.00                                   
formed                                                                    
color                                                                     
Density of                                                                
       0.02                                                               
           0.03                                                           
              0.04                                                        
                 0.05                                                     
                    0.07                                                  
                       0.02                                               
                          0.03                                            
                             0.03                                         
                                0.05                                      
                                   0.08                                   
fog                                                                       
Blur             a                 a                                      
       none                                                               
           none                                                           
              none                                                        
                 little                                                   
                    exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   little                                 
Resolving                                                                 
       ○                                                           
           ⊚                                               
              ⊚                                            
                 ○                                                 
                    ○                                              
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
power                                                                     
Total  ○                                                           
           ⊚                                               
              ⊚                                            
                 Δ                                                  
                    Δ                                               
                       ○                                           
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   Δ                                
evaluation                                                                
__________________________________________________________________________
 
    
     
                                           Table 7                                 
__________________________________________________________________________
Experiment                                                                
No.    73  74 75 76 77 78 79 80 81 82                                     
__________________________________________________________________________
D-125  70  70 70 70 70 70 70 70 70 70                                     
       parts                                                              
           parts                                                          
              parts                                                       
                 parts                                                    
                    parts                                                 
                       parts                                              
                          parts                                           
                             parts                                        
                                parts                                     
                                   parts                                  
Methyl 5 &#34; 10 &#34;                                                           
              20 &#34;                                                        
                 30 &#34;                                                     
                    40 &#34;                                                  
                       15 &#34;                                               
                          15 &#34;                                            
                             15 &#34;                                         
                                15 &#34;                                      
                                   15 &#34;                                   
behenate                                                                  
CVL    30 &#34;                                                               
           30 &#34;                                                           
              30 &#34;                                                        
                 30 &#34;                                                     
                    30 &#34;                                                  
                       5 &#34;                                                
                          10 &#34;                                            
                             20 &#34;                                         
                                40 &#34;                                      
                                   60 &#34;                                   
Pulverizing                                                               
       ⊚                                                   
           ⊚                                               
              ○                                                    
                 Δ                                                  
                    ×                                               
                       ⊚                                   
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
property                                                                  
Fusing to        a                 a                                      
drum   none                                                               
           none                                                           
              none                                                        
                 little                                                   
                    exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   little                                 
Charge-                                                                   
       -   -  -  +- +  -  -  -  -  +-                                     
ability                                                                   
Fixing 190° C.                                                     
           175                                                            
              165                                                         
                 160                                                      
                    155                                                   
                       160                                                
                          165                                             
                             170                                          
                                190                                       
                                   210                                    
temperature                                                               
Maximum                                                                   
density of                                                                
formed 0.53                                                               
           0.80                                                           
              0.95                                                        
                 1.00                                                     
                    1.01                                                  
                       0.81                                               
                          1.01                                            
                             1.00                                         
                                1.00                                      
                                   1.00                                   
color                                                                     
Density of                                                                
fog    0.02                                                               
           0.03                                                           
              0.04                                                        
                 0.05                                                     
                    0.07                                                  
                       0.02                                               
                          0.03                                            
                             0.03                                         
                                0.05                                      
                                   0.08                                   
Blur             a                 a                                      
       none                                                               
           none                                                           
              none                                                        
                 little                                                   
                    exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   little                                 
Resolving                                                                 
       ○                                                           
           ⊚                                               
              ⊚                                            
                 ○                                                 
                    ○                                              
                       ○                                           
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
power                                                                     
Total  ○                                                           
           ⊚                                               
              ⊚                                            
                 Δ                                                  
                    Δ                                               
                       ○                                           
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   Δ                                
evaluation                                                                
__________________________________________________________________________
 
    
     
                                           Table 8                                 
__________________________________________________________________________
Experiment                                                                
No.    83  84 85 86 87 88 89 90 91 92                                     
__________________________________________________________________________
D-125  70  70 70 70 70 70 70 70 70 70                                     
       parts                                                              
           parts                                                          
              parts                                                       
                 parts                                                    
                    parts                                                 
                       parts                                              
                          parts                                           
                             parts                                        
                                parts                                     
                                   parts                                  
Ethyl  5 &#34; 10 &#34;                                                           
              20 &#34;                                                        
                 30 &#34;                                                     
                    40 &#34;                                                  
                       15 &#34;                                               
                          15 &#34;                                            
                             15 &#34;                                         
                                15 &#34;                                      
                                   15 &#34;                                   
behenate                                                                  
CVL    30 &#34;                                                               
           30 &#34;                                                           
              30 &#34;                                                        
                 30 &#34;                                                     
                    30 &#34;                                                  
                       5 &#34;                                                
                          10 &#34;                                            
                             20 &#34;                                         
                                40 &#34;                                      
                                   60 &#34;                                   
Pulverizing                                                               
       ⊚                                                   
           ⊚                                               
              ○                                                    
                 Δ                                                  
                    ×                                               
                       ⊚                                   
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
property                                                                  
Fusing to        a                 a                                      
drum   none                                                               
           none                                                           
              none                                                        
                 little                                                   
                    exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   little                                 
Charge-                                                                   
       -   -  -  +- +  -  -  -  -  +-                                     
ability                                                                   
Fixing 190° C.                                                     
           175                                                            
              165                                                         
                 160                                                      
                    155                                                   
                       160                                                
                          165                                             
                             170                                          
                                190                                       
                                   210                                    
temperature                                                               
Maximum                                                                   
density of                                                                
       0.60                                                               
           0.79                                                           
              1.00                                                        
                 1.01                                                     
                    1.00                                                  
                       0.80                                               
                          1.01                                            
                             1.01                                         
                                1.00                                      
                                   1.00                                   
formed                                                                    
color                                                                     
Density of                                                                
       0.02                                                               
           0.03                                                           
              0.04                                                        
                 0.05                                                     
                    0.07                                                  
                       0.02                                               
                          0.03                                            
                             0.03                                         
                                0.05                                      
                                   0.08                                   
fog                                                                       
Blur             a                 a                                      
       none                                                               
           none                                                           
              none                                                        
                 little                                                   
                    exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   little                                 
Resolving                                                                 
       ○                                                           
           ⊚                                               
              ⊚                                            
                 ○                                                 
                    ○                                              
                       ○                                           
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
power                                                                     
Total  ○                                                           
           ⊚                                               
              ⊚                                            
                 Δ                                                  
                    Δ                                               
                       ○                                           
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   Δ                                
evaluation                                                                
__________________________________________________________________________
 
    
     
                                           Table 9                                 
__________________________________________________________________________
Experiment                                                                
No.    93  94 95 96 97 98 99 100                                          
                                101                                       
                                   102                                    
                                      103                                 
                                         104                              
                                            105                           
                                               106                        
__________________________________________________________________________
D-125  25  50 70 85 70 70 70 70 70 70 70 70 70 70                         
       parts                                                              
           parts                                                          
              parts                                                       
                 parts                                                    
                    parts                                                 
                       parts                                              
                          parts                                           
                             parts                                        
                                parts                                     
                                   parts                                  
                                      parts                               
                                         parts                            
                                            parts                         
                                               parts                      
Leuric              5 &#34;                                                   
                       10 &#34;                                               
                          20 &#34;                                            
                             30 &#34;                                         
                                40 &#34;                                      
                                   15 &#34;                                   
                                      15 &#34;                                
                                         15 &#34;                             
                                            15 &#34;                          
                                               15 &#34;                       
amide                                                                     
CVL    75 &#34;                                                               
           50 &#34;                                                           
              30 &#34;                                                        
                 15 &#34;                                                     
                    30 &#34;                                                  
                       30 &#34;                                               
                          30 &#34;                                            
                             30 &#34;                                         
                                30 &#34;                                      
                                   5 &#34;                                    
                                      10 &#34;                                
                                         20 &#34;                             
                                            40 &#34;                          
                                               60 &#34;                       
Pulverizing                                                               
       Δ                                                            
           ○                                                       
              ⊚                                            
                 ⊚                                         
                    ⊚                                      
                       ⊚                                   
                          ○                                        
                             Δ                                      
                                ×                                   
                                   ⊚                       
                                      ⊚                    
                                         ⊚                 
                                            ○                      
                                                501                       
property                                                                  
Fusing to                    a                 a                          
drum   none                                                               
           none                                                           
              none                                                        
                 none                                                     
                    none                                                  
                       none                                               
                          none                                            
                             little                                       
                                exist                                     
                                   none                                   
                                      none                                
                                         none                             
                                            none                          
                                               little                     
Charge-                                                                   
       +   +- -  -  -  -  -  +- +  -  -  -  -  +-                         
ability                                                                   
Fixing                                                                    
temperature                                                               
       300° C.                                                     
           290                                                            
              280                                                         
                 270                                                      
                    225                                                   
                       210                                                
                          200                                             
                             195                                          
                                185                                       
                                   195                                    
                                      200                                 
                                         205                              
                                            225                           
                                               245                        
Maximum                                                                   
density of                                                                
       0.30                                                               
           0.30                                                           
              0.20                                                        
                 0.20                                                     
                    0.60                                                  
                       0.80                                               
                          1.00                                            
                             1.05                                         
                                1.01                                      
                                   0.8                                    
                                      1.00                                
                                         1.02                             
                                            1.01                          
                                               1.00                       
formed                                                                    
color                                                                     
Density of                                                                
       0.01                                                               
           0.01                                                           
              0.01                                                        
                 0.01                                                     
                    0.02                                                  
                       0.03                                               
                          0.04                                            
                             0.05                                         
                                0.07                                      
                                   0.02                                   
                                      0.03                                
                                         0.03                             
                                            0.05                          
                                               0.08                       
fog                                                                       
Blur                         a                 a                          
       exist                                                              
           exist                                                          
              none                                                        
                 none                                                     
                    none                                                  
                       none                                               
                          none                                            
                             little                                       
                                exist                                     
                                   none                                   
                                      none                                
                                         none                             
                                            none                          
                                               little                     
Resolving                                                                 
       Δ                                                            
           Δ                                                        
              ○                                                    
                 ○                                                 
                    ○                                              
                       ⊚                                   
                          ⊚                                
                             ○                                     
                                Δ                                   
                                   ○                               
                                      ⊚                    
                                         ⊚                 
                                            ○                      
                                               ○                   
power                                                                     
Total  Δ                                                            
           Δ                                                        
              ○                                                    
                 ○                                                 
                    ○                                              
                       ⊚                                   
                          ⊚                                
                             Δ                                      
                                Δ                                   
                                   ○                               
                                      ⊚                    
                                         ⊚                 
                                            ○                      
                                               Δ                    
evaluation                                                                
__________________________________________________________________________
 
    
     
                                           Table 10                                
__________________________________________________________________________
Experiment                                                                
No.    107 108                                                            
              109                                                         
                 110                                                      
                    111                                                   
                       112                                                
                          113                                             
                             114                                          
                                115                                       
                                   116                                    
__________________________________________________________________________
D-125  70  70 70 70 70 70 70 70 70 70                                     
       parts                                                              
           parts                                                          
              parts                                                       
                 parts                                                    
                    parts                                                 
                       parts                                              
                          parts                                           
                             parts                                        
                                parts                                     
                                   parts                                  
Leuric                                                                    
anilide                                                                   
       5 &#34; 10 &#34;                                                           
              20 &#34;                                                        
                 30 &#34;                                                     
                    40 &#34;                                                  
                       15 &#34;                                               
                          10 &#34;                                            
                             20 &#34;                                         
                                40 &#34;                                      
                                   60                                     
CVL    30 &#34;                                                               
           30 &#34;                                                           
              30 &#34;                                                        
                 30 &#34;                                                     
                    30 &#34;                                                  
                       15 &#34;                                               
                          10 &#34;                                            
                             20 &#34;                                         
                                40 &#34;                                      
                                   60 &#34;                                   
Pulverizing                                                               
       ⊚                                                   
           ⊚                                               
              ○                                                    
                 Δ                                                  
                    ×                                               
                       ⊚                                   
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
property                                                                  
Fusing to        a                 a                                      
drum   none                                                               
           none                                                           
              none                                                        
                 little                                                   
                    exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   little                                 
Charge-                                                                   
       -   -  -  +- +  -  -  -  -  +-                                     
ability                                                                   
Fixing                                                                    
temperature                                                               
       200 185                                                            
              175                                                         
                 170                                                      
                    165                                                   
                       170                                                
                          175                                             
                             180                                          
                                200                                       
                                   200                                    
Maximum                                                                   
density of                                                                
       0.57                                                               
           0.81                                                           
              1.05                                                        
                 1.01                                                     
                    1.00                                                  
                       0.87                                               
                          0.95                                            
                             1.03                                         
                                1.05                                      
                                   1.01                                   
formed                                                                    
color                                                                     
Density of                                                                
       0.02                                                               
           0.02                                                           
              0.04                                                        
                 0.04                                                     
                    0.07                                                  
                       0.02                                               
                          0.03                                            
                             0.04                                         
                                0.05                                      
                                   0.07                                   
fog                                                                       
Blur             a                 a                                      
       none                                                               
           none                                                           
              none                                                        
                 little                                                   
                    exist                                                 
                       none                                               
                          none                                            
                             none                                         
                                none                                      
                                   little                                 
Resolving                                                                 
       ○                                                           
           ⊚                                               
              ⊚                                            
                 ○                                                 
                    ○                                              
                       ○                                           
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   ○                               
power                                                                     
Total  ○                                                           
           ⊚                                               
              ⊚                                            
                 Δ                                                  
                    Δ                                               
                       Δ                                            
                          ⊚                                
                             ⊚                             
                                ○                                  
                                   Δ                                
evaluation                                                                
__________________________________________________________________________
 
    
     
                                           Table 11                                
__________________________________________________________________________
Experiment                                                                
No.    117                                                                
          118                                                             
             119                                                          
                120                                                       
                   121                                                    
                      122                                                 
                         123                                              
                            124                                           
                               125                                        
                                  126                                     
__________________________________________________________________________
D-125  70 70 70 70 70 70 70 70 70 70                                      
       parts                                                              
          parts                                                           
             parts                                                        
                parts                                                     
                   parts                                                  
                      parts                                               
                         parts                                            
                            parts                                         
                               parts                                      
                                  parts                                   
Leuric                                                                    
N-methyl                                                                  
       5 &#34;                                                                
          10 &#34;                                                            
             20 &#34;                                                         
                30 &#34;                                                      
                   40 &#34;                                                   
                      15 &#34;                                                
                         15 &#34;                                             
                            15 &#34;                                          
                               15 &#34;                                       
                                  15 &#34;                                    
amide                                                                     
CVL    30 &#34;                                                               
          30 &#34;                                                            
             30 &#34;                                                         
                30 &#34;                                                      
                   30 &#34;                                                   
                      5 &#34;                                                 
                         10 &#34;                                             
                            20 &#34;                                          
                               40 &#34;                                       
                                  60 &#34;                                    
Pulverizing                                                               
       ⊚                                                   
          ⊚                                                
             ○                                                     
                Δ                                                   
                   ×                                                
                      ⊚                                    
                         ⊚                                 
                            ⊚                              
                               ○                                   
                                  ○                                
Fusing to       a                 a                                       
drum   none                                                               
          none                                                            
             none                                                         
                little                                                    
                   exist                                                  
                      none                                                
                         none                                             
                            none                                          
                               none                                       
                                  little                                  
Charge-                                                                   
       -  -  -  +- +  -  -  -  -  +-                                      
ability                                                                   
Fixing                                                                    
temperature                                                               
       195                                                                
          180                                                             
             170                                                          
                165                                                       
                   160                                                    
                      165                                                 
                         170                                              
                            175                                           
                               195                                        
                                  215                                     
Maximum                                                                   
density of                                                                
formed                                                                    
color  0.6                                                                
          0.75                                                            
             1.00                                                         
                1.05                                                      
                   1.01                                                   
                      0.81                                                
                         1.01                                             
                            1.00                                          
                               1.05                                       
                                  1.02                                    
Density of                                                                
fog    0.02                                                               
          0.03                                                            
             0.04                                                         
                0.05                                                      
                   0.07                                                   
                      0.02                                                
                         0.03                                             
                            0.03                                          
                               0.05                                       
                                  0.07                                    
             a                 a                                          
Blur   none                                                               
          none                                                            
             little                                                       
                exist                                                     
                   none                                                   
                      none                                                
                         none                                             
                            none                                          
                               little                                     
Resolving                                                                 
       ○                                                           
          ⊚                                                
             ⊚                                             
                ○                                                  
                   ○                                               
                      ○                                            
                         ⊚                                 
                            ⊚                              
                               ○                                   
                                  ○                                
power                                                                     
Total  ○                                                           
          ⊚                                                
             ⊚                                             
                Δ                                                   
                   Δ                                                
                      ○                                            
                         ⊚                                 
                            ⊚                              
                               ○                                   
                                  Δ                                 
evaluation                                                                
__________________________________________________________________________
 
    
     
                                           Table 12                                
__________________________________________________________________________
Experiment                                                                
No.    127                                                                
          128                                                             
             129                                                          
                130                                                       
                   131                                                    
                      132                                                 
                         133                                              
                            134                                           
                               135                                        
                                  136                                     
__________________________________________________________________________
D-125  70 70 70 70 70 70 70 70 70 70                                      
       parts                                                              
          parts                                                           
             parts                                                        
                parts                                                     
                   parts                                                  
                      parts                                               
                         parts                                            
                            parts                                         
                               parts                                      
                                  parts                                   
Leuric                                                                    
dodecyl                                                                   
       5 &#34;                                                                
          10 &#34;                                                            
             20 &#34;                                                         
                30 &#34;                                                      
                   40 &#34;                                                   
                      15 &#34;                                                
                         15 &#34;                                             
                            15 &#34;                                          
                               15 &#34;                                       
                                  15 &#34;                                    
amide                                                                     
CVL    30 &#34;                                                               
          30 &#34;                                                            
             30 &#34;                                                         
                30 &#34;                                                      
                   30 &#34;                                                   
                      5 &#34;                                                 
                         10 &#34;                                             
                            20 &#34;                                          
                               40 &#34;                                       
                                  60 &#34;                                    
Pulverizing                                                               
property                                                                  
       ⊚                                                   
          ⊚                                                
             ○                                                     
                Δ                                                   
                   ×                                                
                      ⊚                                    
                         ⊚                                 
                            ⊚                              
                               ○                                   
                                  ○                                
Fusing to                                                                 
       a  a  a  a  exist                                                  
                      none                                                
                         none                                             
                            none                                          
                               none                                       
                                  a                                       
drum   little                                                             
          little                                                          
             little                                                       
                little            little                                  
Charge-                                                                   
ability                                                                   
       -  -  -  +- +  -  -  -  -  +-                                      
Fixing 200                                                                
          185                                                             
             175                                                          
                170                                                       
                   165                                                    
                      170                                                 
                         175                                              
                            180                                           
                               200                                        
                                  220                                     
temperature                                                               
Maximum                                                                   
density of                                                                
       0.55                                                               
          0.81                                                            
             1.01                                                         
                1.03                                                      
                   1.05                                                   
                      0.80                                                
                         1.01                                             
                            1.00                                          
                               1.00                                       
                                  1.02                                    
formed                                                                    
color                                                                     
Density of                                                                
       0.02                                                               
          0.03                                                            
             0.04                                                         
                0.05                                                      
                   0.07                                                   
                      0.02                                                
                         0.03                                             
                            0.03                                          
                               0.05                                       
                                  0.07                                    
fog                                                                       
Blur   none                                                               
          none                                                            
             none                                                         
                a  none                                                   
                      none                                                
                         none                                             
                            none                                          
                               none                                       
                                  a                                       
                little            little                                  
Resolving                                                                 
       ○                                                           
          ⊚                                                
             ⊚                                             
                ○                                                  
                   ○                                               
                      ○                                            
                         ⊚                                 
                            ⊚                              
                               ○                                   
                                  ○                                
power                                                                     
Total  ○                                                           
          ⊚                                                
             ⊚                                             
                Δ                                                   
                   Δ                                                
                      Δ                                             
                         ⊚                                 
                            ⊚                              
                               ○                                   
                                  Δ                                 
evaluation                                                                
__________________________________________________________________________
 
    
     The above results indicate that increasing the amount of a charge controlling resin (styrene polymer and the like) to a color forming auxiliary agent results in lowering of color forming efficiency and low temperature fixing efficiency so that any satisfactory image can not be obtained. As the added amount of a color forming auxiliary agent increases to the charge controlling resin, the controlling effect is lowered and blur is formed at detailed portion of image and image quality is lowered though low temperature fixation proceeds further. 
     As the added amount of a color forming agent (A) is increased with respect to a charge controlling resin, the controlling effect is lowered in a manner similar to a color forming auxiliary agent and the color forming efficiency is not increased as much. 
     The surface of a photosensitive member or image receiving sheet used in this invention is treated with a color forming agent (B), and if desired, a mixture with a color forming auxiliary agent and a binder. 
     The color forming agent (B) and a mixture with a color forming auxiliary agent may be applied to a photosensitive member or image receiving sheet by spraying, electrostatic coating, soaking, fluidizing bed coating, brushing, roll coating and any optical conventional method. 
     A small amount of a binder may be used for adhering the formulation of the present invention to surface of a photosensitive member or image receiving sheet. Representative binders are styrene-butadiene latex, polyvinylpyrrolidone, acryl latex, PVA, polyvinyl acetate copolymer and mixtures thereof. Conventional additives such as antioxidant, emulsifier, polishing agent, solvent, surfactant, dispersing agent, antifoaming agent, and coloring agent. The amount of binder is preferably less than about 20% based on the weight of a mixture of a color forming agent (B) and a color forming auxiliary agent since effective color forming and fixation can be effected when the toner contacts a large amount of mixture of color forming agent (B) and color forming auxiliary agent at the surface of the image receiving sheet to which the toner is fixed. 
     Paper sheet or web is usually used as an image receiving sheet. The paper may be composed of organic or inorganic fiber such as cellulose, modified cellulose polymerizable resin, glass, and asbestos fiber. 
     In the following, there are shown experimental example illustrating the effect and function of a color forming auxiliary agent at an image receiving sheet surface. 
     With respect to phenol-aldehyde polymer as acidic polymer material and stearic acid as fatty acid at various ratio, there were determined fixing temperature and color forming density. The result is shown in Table 13. This result is almost similar to other polymers and fatty acids. 
     When a fatty acid such as stearic acid is used in a small amount, the color forming and fixing temperature is high. On the contrary, when the ratio of stearic acid increases, stearic acid remarkably penetrates into an image receiving sheet upon melting of stearic acid and the paper becomes transparent. A serious drawback caused by increased amount of stearic acid is that the color forming density is low. The optimum point where low temperature fixation is possible and no transparency occurs and further the color forming density is high is at a ratio of a color forming auxiliary agent to a color forming agent (B) being 5 - 40 parts, preferably, 10 - 30 parts: 50 parts. A result of using a solid plasticizer in place of fatty acid is shown in Table 14. Solid plasticizer does not cause transparency even when the amount of solid plasticizer is high, and the color forming density becomes fairly low. 
     Optimum ratio of solid plasticizer to color forming agent (B) is 5- 40 parts, preferred with 10 - 30 parts, : 50 parts. 
     In a similar way, there were determined fixing temperature and color forming density when phenol-aldehyde polymer was used as acidic polymer material of an image receiving sheet and aluminum stearate as fatty acid metal salt. The result is shown in Table 15. It has been found that this result is almost the same as in case of other polymers and other fatty acid metal salts. When the amount of a fatty acid metal salt such as aluminum stearate is little, the color forming and fixing temperature is high. On the contrary, when the amount of aluminum stearate increases, there is a drawback that the color forming density is low. 
     An appropriate addition amount of fatty acid metal salt capable of giving low temperature fixing effect as well as high color forming density ranges from 5 to 40 parts, preferred with from 10 to 30 parts per 50 parts of color forming agent (B). 
     Table 16 shows a result obtained by using monoglycerol stearate, a kind of fatty acid ester, as color forming auxiliary agent. 
     The optimum mixing ratio is the same as that for fatty acid. 
     Table 17 shows a result obtained by using tridecylic acid amide, a kind of fatty acid amide, as color forming auxiliary agent. The optimum ratio is the same as that for fatty acid metal salt. 
     Table 18 shows a result in case of using diphenylbutyric acid as color forming agent (B). 
     
                                           Table 13                                
__________________________________________________________________________
Phenol-Aldehyde                                                           
Polymer                                                                   
(color forming                                                            
             50   50   50  50  50  50   50   50   50                      
agent B)     parts                                                        
                  parts                                                   
                       parts                                              
                           parts                                          
                               parts                                      
                                   parts                                  
                                        parts                             
                                             parts                        
                                                  parts                   
__________________________________________________________________________
Stearic acid                                                              
(color forming                                                            
             0&#34;   5&#34;   10&#34; 20&#34; 30&#34; 40&#34;  50&#34;  60&#34;  70&#34;                     
auxiliary agent)                                                          
Styrene- Butadiene                                                        
Latex        20&#34;  20&#34;  20&#34; 20&#34; 20&#34; 20&#34;  20&#34;  20&#34;  20&#34;                     
(Low 686)                                                                 
Water        150&#34; 150&#34; 150&#34;                                               
                           150&#34;                                           
                               150&#34;                                       
                                   150&#34; 150&#34; 150&#34; 150&#34;                    
Sodium salt of                                                            
treated resin                                                             
             0.4&#34; 0.4&#34; 0.4&#34;                                               
                           0.4&#34;                                           
                               0.4&#34;                                       
                                   0.4&#34; 0.4&#34; 0.4&#34; 0.4&#34;                    
(Dresinate X)                                                             
     C.V.L.                                                               
Fixing                                                                    
     toner   280° C.                                               
                  270° C.                                          
                       240° C.                                     
                           200° C.                                 
                               190° C.                             
                                   170°  C.                        
                                        160° C.                    
                                             160° C.               
                                                  160° C.          
Temper-                                                                   
     CVI + styrene                                                        
ature                                                                     
     toner   270  260  240 200 180 170  160  160  160                     
Image density                                                             
             1.2  1.2  1.2 1.1 1.1 0.9  0.8  0.8  0.8                     
             high high good                                               
                           good                                           
                               good                                       
                                   An   An   An   An                      
             color                                                        
                  color                                                   
                       image                                              
                           image                                          
                               image                                      
                                   image                                  
                                        image                             
                                             image                        
                                                  image                   
Note         forming                                                      
                  forming          receiv-                                
                                        receiv-                           
                                             receiv-                      
                                                  receiv-                 
             temper-                                                      
                  temper-          ing  ing  ing  ing                     
             ature,                                                       
                  ature,           sheet                                  
                                        sheet                             
                                             sheet                        
                                                  sheet                   
             good good             becomes                                
                                        becomes                           
                                             becomes                      
                                                  becomes                 
             image                                                        
                  image            trans-                                 
                                        trans-                            
                                             trans-                       
                                                  trans-                  
                                   parent                                 
                                        parent                            
                                             parent                       
                                                  parent                  
__________________________________________________________________________
 
    
     
                                           Table 14                                
__________________________________________________________________________
Phenol-Aldehyde                                                           
Polymer      50   50   50   50  50  50  50  50  50                        
(color forming                                                            
             50   50   50   50  50  50  50  50  50                        
agent B)     parts                                                        
                  parts                                                   
                       parts                                              
                            parts                                         
                                parts                                     
                                    parts                                 
                                        parts                             
                                            parts                         
                                                parts                     
__________________________________________________________________________
EGDB                                                                      
(color forming                                                            
             0&#34;   5&#34;   10&#34;  20&#34; 30&#34; 40&#34; 50&#34; 60&#34; 70&#34;                       
auxiliary agent)                                                          
Sytrene-Butadiene                                                         
Latex        20&#34;  20&#34;  20&#34;  20&#34; 20&#34; 20&#34; 20&#34; 20&#34; 20&#34;                       
(Now 686)                                                                 
Water        150&#34; 150&#34; 150&#34; 150&#34;                                          
                                150&#34;                                      
                                    150&#34;                                  
                                        150&#34;                              
                                            150&#34;                          
                                                150&#34;                      
Sodium salt of                                                            
treated resin                                                             
             0.4&#34; 0.4&#34; 0.4&#34; 0.4&#34;                                          
                                0.4&#34;                                      
                                    0.4&#34;                                  
                                        0.4&#34;                              
                                            0.4&#34;                          
                                                0.4&#34;                      
(Dresinate X)                                                             
     C.V.L.  280° C.                                               
                  270° C.                                          
                       260° C.                                     
                            210° C.                                
                                190° C.                            
                                    180° C.                        
                                        160° C.                    
                                            160° C.                
                                                160° C.            
Fixing                                                                    
     toner                                                                
Temper-                                                                   
     CVL + styrene                                                        
ature        270  260  250  200 180 170 150 150 150                       
     toner                                                                
Image density                                                             
             1.2  1.2  1.2  1.1 1.0 0.8 0.6 0.6 0.6                       
             high high high good                                          
                                good                                      
                                    low low low low                       
             color                                                        
                  color                                                   
                       color                                              
                            image                                         
                                image                                     
                                    image                                 
                                        image                             
                                            image                         
                                                image                     
Note         forming                                                      
                  forming                                                 
                       forming      density                               
                                        density                           
                                            density                       
                                                density                   
             temper-                                                      
                  temper-                                                 
                       temper-                                            
             ature,                                                       
                  ature,                                                  
                       ature,                                             
             good good good                                               
             image                                                        
                  image                                                   
                       image                                              
__________________________________________________________________________
 
    
     
                                           Table 15                                
__________________________________________________________________________
Phenol-Aldehyde                                                           
Polymer                                                                   
(color forming                                                            
             50   50   50  50  50  50  50  50  50                         
agent B)     parts                                                        
                  parts                                                   
                       parts                                              
                           parts                                          
                               parts                                      
                                   parts                                  
                                       parts                              
                                           parts                          
                                               parts                      
__________________________________________________________________________
Alminium stearate                                                         
(color forming                                                            
             0&#34;   5&#34;   10&#34; 20&#34; 30&#34; 40&#34; 50&#34; 60&#34; 70&#34;                        
auxiliary agent)                                                          
Styrene-Butadiene                                                         
Latex        20&#34;  20&#34;  20&#34; 20&#34; 20&#34; 20&#34; 20&#34; 20&#34; 20&#34;                        
(Low 686)                                                                 
Water        150&#34; 150&#34; 150&#34;                                               
                           150&#34;                                           
                               150&#34;                                       
                                   150&#34;                                   
                                       150&#34;                               
                                           150&#34;                           
                                               150&#34;                       
Sodium salt of                                                            
treated resin                                                             
             0.4&#34; 0.4&#34; 0.4&#34;                                               
                           0.4&#34;                                           
                               0.4&#34;                                       
                                   0.4&#34;                                   
                                       0.4&#34;                               
                                           0.4&#34;                           
                                               0.4&#34;                       
(Dresinate X)                                                             
     C.V.L.                                                               
Fixing                                                                    
     toner                                                                
Temper-                                                                   
     CVL + styrene                                                        
ature        270  260  240 200 180 170 160 160 160                        
     toner                                                                
Image density                                                             
             1.2  1.2  1.2 1.1 1.1 0.8 0.7 0.7 0.7                        
             high high good                                               
                           good                                           
                               good                                       
                                   low low low low                        
             color                                                        
                  color                                                   
                       image                                              
                           image                                          
                               image                                      
                                   image                                  
                                       image                              
                                           image                          
                                               image                      
Note         forming                                                      
                  forming          density                                
                                       density                            
                                           density                        
                                               density                    
             temper-                                                      
                  temper-                                                 
             ature,                                                       
                  ature,                                                  
             good good                                                    
             image                                                        
                  image                                                   
__________________________________________________________________________
 
    
     
                                           Table 16                                
__________________________________________________________________________
Phenol-Aldehyde                                                           
Polymer                                                                   
(color forming                                                            
             50   50   50   50   50   50  50  50  50                      
agent B)     parts                                                        
                  parts                                                   
                       parts                                              
                            parts                                         
                                 parts                                    
                                      parts                               
                                          parts                           
                                              parts                       
                                                  parts                   
__________________________________________________________________________
Monoglyceral                                                              
stearate     0&#34;   5&#34;   10&#34;  20&#34;  30&#34;  40&#34; 50&#34; 60&#34; 70&#34;                     
(color forming                                                            
auxiliary agent)                                                          
Styrene-Butadiene                                                         
Latex        20&#34;  20&#34;  20&#34;  20&#34;  20&#34;  20&#34; 20&#34; 20&#34; 20&#34;                     
(Low 686)                                                                 
Water        150&#34; 150&#34; 150&#34; 150&#34; 150&#34; 150&#34;                                
                                          150&#34;                            
                                              150&#34;                        
                                                  150&#34;                    
Sodium salt of                                                            
rosin        0.4&#34; 0.4&#34; 0.4&#34; 0.4&#34; 0.4&#34; 0.4&#34;                                
                                          0.4&#34;                            
                                              0.4&#34;                        
                                                  0.4&#34;                    
     C.V.L.                                                               
Fixing                                                                    
     toner   280  270  200  190  160  160 160 160 160                     
Temper-                                                                   
     CVL + styrene                                                        
             270  260  200  180  150  150 150 150 150                     
ature                                                                     
     toner                                                                
Dnox         1.2  1.2  1.2  1.2  1.2  0.9 0.8 0.8 0.8                     
             high high high high high low low low low                     
             color                                                        
                  color                                                   
                       color                                              
                            color                                         
                                 color                                    
                                      image                               
                                          image                           
                                              image                       
                                                  image                   
Note         forming                                                      
                  forming                                                 
                       forming                                            
                            forming                                       
                                 forming                                  
                                      density                             
                                          density                         
                                              density                     
                                                  density                 
             temper-                                                      
                  temper-                                                 
                       temper-                                            
                            temper-                                       
                                 temper-                                  
             ature,                                                       
                  ature,                                                  
                       ature,                                             
                            ature,                                        
                                 ature,                                   
             high high low  low  low                                      
             fixing                                                       
                  fixing                                                  
                       fixing                                             
                            fixing                                        
                                 fixing                                   
             temper-                                                      
                  temper-                                                 
                       temper-                                            
                            temper-                                       
                                 temper-                                  
             ature                                                        
                  ature                                                   
                       ature                                              
                            ature                                         
                                 ature                                    
__________________________________________________________________________
 
    
     
                                           Table 17                                
__________________________________________________________________________
Phenol-Aldehyde                                                           
Polymer                                                                   
(color forming                                                            
             50   50   50   50  50  50  50  50  50                        
agent B)     parts                                                        
                  parts                                                   
                       parts                                              
                            parts                                         
                                parts                                     
                                    parts                                 
                                        parts                             
                                            parts                         
                                                parts                     
__________________________________________________________________________
Tridecylic acid                                                           
amide        0&#34;   5&#34;   10&#34;  20&#34; 30&#34; 40&#34; 50&#34; 60&#34; 70&#34;                       
(color forming                                                            
auxiliary agent)                                                          
Styrene-Butadiene                                                         
Latex        20&#34;  20&#34;  20&#34;  20&#34; 20&#34; 20&#34; 20&#34; 20&#34; 20&#34;                       
(Dow 686)                                                                 
Water        150&#34; 150&#34; 150&#34; 150&#34;                                          
                                150&#34;                                      
                                    150&#34;                                  
                                        150&#34;                              
                                            150&#34;                          
                                                150&#34;                      
Sodium salt of                                                            
treated rosin                                                             
             0.4&#34; 0.4&#34; 0.4&#34; 0.4&#34;                                          
                                0.4&#34;                                      
                                    0.4&#34;                                  
                                        0.4&#34;                              
                                            0.4&#34;                          
                                                0.4&#34;                      
(Bresinate X)                                                             
     C.V.L.                                                               
Fixing                                                                    
     toner   280° C.                                               
                  270° C.                                          
                       260° C.                                     
                            210° C.                                
                                190° C.                            
                                    180° C.                        
                                        160°  C.                   
                                            160° C.                
                                                160° C.            
Temper-                                                                   
ature                                                                     
     CVL + styrene                                                        
             270  260  250  200 180 170 150 150 150                       
     toner                                                                
Image density                                                             
             1.2  1.2  1.2  1.1 1.0 0.8 0.6 0.6 0.6                       
             high high high good                                          
                                good                                      
                                    low low low low                       
             color                                                        
                  color                                                   
                       color                                              
                            image                                         
                                image                                     
                                    image                                 
                                        image                             
                                            image                         
                                                image                     
Note         forming                                                      
                  forming                                                 
                       forming      density                               
                                        density                           
                                            density                       
                                                density                   
             temper-                                                      
                  temper-                                                 
                       temper-                                            
             ature,                                                       
                  ature,                                                  
                       ature,                                             
             good good good                                               
             image                                                        
                  image                                                   
                       image                                              
__________________________________________________________________________
 
    
     
                                           Table 18                                
__________________________________________________________________________
DPBA                                                                      
(color forming                                                            
             50   50   50  50  50  50   50   50   50                      
agent B)     parts                                                        
                  parts                                                   
                       parts                                              
                           parts                                          
                               parts                                      
                                   parts                                  
                                        parts                             
                                             parts                        
                                                  parts                   
__________________________________________________________________________
Stearic acid                                                              
(color forming                                                            
             0&#34;   5&#34;   10&#34; 20&#34; 30&#34; 40&#34;  50&#34;  60&#34;  70&#34;                     
auxiliary agent)                                                          
Styrene-Butadiene                                                         
Latex        20&#34;  20&#34;  20&#34; 20&#34; 20&#34; 20&#34;  20&#34;  20&#34;  20&#34;                     
(Dow 686)                                                                 
Water        150&#34; 150&#34; 150&#34;                                               
                           150&#34;                                           
                               150&#34;                                       
                                   150&#34; 150&#34; 150&#34; 150&#34;                    
Sodium salt of                                                            
treated rosin                                                             
             0.4&#34; 0.4&#34; 0.4&#34;                                               
                           0.4&#34;                                           
                               0.4&#34;                                       
                                   0.4&#34; 0.4&#34; 0.4&#34; 0.4&#34;                    
(Dresinate X)                                                             
     C.V.L.                                                               
Fixing                                                                    
     toner   28° C.                                                
                  270° C.                                          
                       240° C.                                     
                           200° C.                                 
                               190° C.                             
                                   170° C.                         
                                        160° C.                    
                                             160° C.               
                                                  160° C.          
Temper-                                                                   
ature                                                                     
     CVL + styrene                                                        
             270  260  240 200 180 170  160  160  160                     
     toner                                                                
Image density                                                             
             1.2  1.2  1.2 1.1 1.1 0.9  0.8  0.8  0.8                     
             high high good                                               
                           good                                           
                               good                                       
                                   An   An   An   An                      
             color                                                        
                  color                                                   
                       image                                              
                           image                                          
                               image                                      
                                   image                                  
                                        image                             
                                             image                        
                                                  image                   
Note         forming                                                      
                  forming          receiv-                                
                                        receiv-                           
                                             receiv-                      
                                                  receiv-                 
             temper-                                                      
                  temper-          ing  ing  ing  ing                     
             ature,                                                       
                  ature,           sheet                                  
                                        sheet                             
                                             sheet                        
                                                  sheet                   
             good good             becomes                                
                                        becomes                           
                                             becomes                      
                                                  becomes                 
             image                                                        
                  image            trans-                                 
                                        trans-                            
                                             trans-                       
                                                  trans-                  
                                   parent                                 
                                        parent                            
                                             parent                       
                                                  parent                  
__________________________________________________________________________
 
    
     The image receiving sheet used for determining the data in the above tables was prepared by coating an aqueous dispersion liquid of a color forming agent (B), a color forming auxiliary agent, styrene-butadiene latex and Dresinate X on a high quality paper in the thickness of 2 - 3 microns. The image density shows an optical density, and &#34;CVL&#34; is Crystal Violet Lactone. 
     In the image receiving sheet of the present invention, a mixture of a color forming agent (B) and a color forming auxiliary agent may be added to the paper at an optional step of paper making. In case of coating the mixture, the resulting coating containing a mixture of a color forming agent (B) and a color forming auxiliary agent of 2 - 20 g., preferred with 5 - 10 g. (as solid) per 1 m 2  can lower the color forming and fixing temperature to a great extent. An amount less than that range also has such effect, but results in low color forming density and irregular coating. On the contrary, when an amount more than that range is used, the fixing temperature increases and curl occurs. 
     When a mixture of a color forming agent (B) and a color forming auxiliary agent is incorporated in paper during beater step or is impregnated in paper after the web is formed, a fairly large amount of the mixture should be present at the surface of paper sheet. In this case, a good result is obtained when the mixture of 10 - 20 g. per 1 m 2  of an image receiving sheet is applied to the image receiving surface as a surface coating. 
     An example of a printing process using an electrophotographic method of the present invention is explained below. 
     There may be used, as a printing master sheet, a developed image which is obtained by developing an electrostatic latent image on an electrophotographic photosensitive member with a toner containing a color forming agent (A) of the present invention. Further, an image obtained by transferring to a transferring member may also be used as a printing master sheet. The master sheet is contacted with an image receiving sheet containing a color forming agent (B) and heated to cause a thermal color forming reaction of a color forming agent (A) with a color forming agent (B) resulting in a visible image. This process can be repeatedly conducted by using a new image receiving sheet to produce many sheets of reproduction. 
     Referring to the drawing, the above process is explained further in detail. A master sheet is prepared by forming an image containing a color forming agent (A) on a surface of a support such as paper, film, electrophotographic photosensitive plate and the like. Referring to FIG. 4, there is illustrated an embodiment of a master sheet. A toner image 12 containing a color forming agent (A) is formed on a paper, film or electrophotographic photosensitive plate 11. 
     Referring to FIG. 5, there is shown a printing member in which a color forming agent (B) layer 13 is provided on an appropriate support 14 such as paper, cloth, film and the like. 
     Referring to FIG. 6, the master sheet in FIG. 4 and the printing member in FIG. 5 are used for reproduction. A master sheet 11, 12 is placed on a plate 17 and a printing member 13, 14 is placed on the master sheet by facing the color forming agent (B) layer to the toner image of the master sheet. A box 15 composed of glass or a thermally conductive material provided with a heater 16 such as infrared ray heater, nichrome wire heater and the like is pressed to the printing member. Thus, a thermal reaction is caused to produce color forming images 18 as shown in FIG. 7. In other words, a part of image containing a color forming agent (A) is absorbed into a layer containing a color forming agent (B) of the printing member, transferred thereto and a color forming reaction occurs to form a colored image by pressing and heating. Further, many reproductions can be obtained by repeating the above-mentioned procedure. 
     Images containing a color forming agent (A) may be produced by various methods. For example, an image is written by hand using an ink containing a color forming agent (A). An image can be formed by an electrophotographic process. A photoconductive photosensitive member, e.g. photoconductive zinc oxide paper, is charged and exposed by a known method, and then subjected to dry development by a magnetic brush method or cascade developing method using a toner containing a color forming agent (A) or wet development by a liquid developer composed of toner containing a color forming agent (A) dispersed in an isoparaffin high insulating liquid. The resulting toner images produced on the zinc oxide paper is used as a master sheet. The light image as used in the above procedure for exposure is a mirror image with respect to the original image. 
     A photoconductive layer of a photoconductive selenium photosensitive drum or a photoconductive zinc oxide photosensitive drum is charged and exposed by a known method and developed with dry developer by a known magnetic brush or cascade developing method. The resulting toner image can be used as a master sheet, or the toner image transferred to an other sheet may be used as a master sheet. 
     A photoconductive selenium photosensitive plate or photoconductive zinc oxide layer is charged, exposed by a known method, and developed with a toner containing a color forming agent (A) dispersed in an isoparaffin high insulating carrier, and the image thus developed or the developed image further transferred to an other sheet can be used as a master sheet. 
     A selective dicharging is applied to a photoconductive layer, such as selenium layer, having an insulating film, and a dry or liquid developer containing a color forming agent (A) is used for development. The resulting toner image can be used as a master sheet. 
     According to the above printing methods, it is possible to produce many sheets of multicolor printing. In a recording method using a thermal color forming reaction of a color forming agent (A) with a color forming agent (B), a plurality of master sheets corresponding to spectrally divided color which has a toner image containing a color forming agent (A) capable of producing a color corresponding to each spectral color. These master sheets are sequentially pressed to a printing member having a color forming agent (B) containing surface and heated by heating at least one of the master sheet and the printing member. 
     An example of color heat sensitive printing method is as shown below. Master sheets are prepared by an electrophotographic means. Usually, three master sheets i.e. red, blue and green master sheets, corresponding to three divided visible spectra, are prepared. 
     First photoconductive photosensitive layer sheet after charged is exposed to a light image through a red filter and developed with a color forming agent (A) capable of giving cyan color. Second photoconductive photosensitive layer sheet after charging is exposed to a light image through a green filter and developed with a color forming agent (A) capable of giving magenta color. Third photoconductive photosensitive layer sheet after charging is exposed to a light image through a blue filter and developed with a color forming agent (A) capable of giving yellow color. The resulting three sheets are used as master sheets. Then, these three master sheets are sequentially pressed to a printing paper containing a color forming agent (B) and heated by using an apparatus as shown in FIG. 6. According to the above mentioned method, fusing color forming is effected by heating so that a mixed color can be obtained since the later formed color does not suppress the former formed color. 
     According to the above mentioned method, a complicated and expensive printing machine is not necessary, and many sheets of reproduction can be easily and quickly obtained. 
     The resulting printed matter is of high density and good quality. 
     A color forming agent (A) and a color forming agent (B) are usually separated from each other so that the printed matter is stable against light and heat as compared with conventional heat sensitive reproduction. 
     The following examples are given for illustrating the present invention, but should not be construed as limiting the present invention. 
     EXAMPLE 1 
     Crystal Violet lactone was ground into a particle size of 1 - 50 microns, preferably, 5 - 20 microns, by an attritor. The particles over 325 mesh sieve was removed from the toner material by sieving. To the resulting toner was added iron powder at a ratio of 8 - 50 weight parts, preferably, 10 - 20 weight parts per one part of the toner. The iron powder was 20 - 70 microns, preferably, 25 - 40 microns in particle size. A negative charge was applied uniformly to the whole surface of a photoconductive zinc oxide, and then the surface was exposed to a light pattern to produce an electrostatic latent image. The latent image was developed with the mixture of iron powder and toner, by means of magnetic brush in a developing apparatus. The toner particles adhered to the negatively charged image portion. 
     The phenolic resin (available as trade name, Tamanol 510 from Arakawa Rinsan K.K.; mp. 80° C.) was mixed and ground with a suitable binder, e.g. styrene-butadiene-latex rubber. The mixture was applied onto a paper to form a coating of about 5 microns thick. The sheet thus formed was used as an image receiving sheet. 
     The toner image was transferred to the image receiving sheet. Then, the sheet was subjected to a color forming fixing by the fixing apparatus shown in FIG. 3 to produce a blue image. The color-forming initiated at a temperature of about 100° C. while the fixing was completed at a temperature of about 180° C. in case of Crystal Violet lactone. 
     In the following examples, preparation procedure, particle sizes of the toner, carrier, and contents of the developing agent were similar to those of Example 1. 
     EXAMPLE 2 
     Malachite Green lactone (MGL) was used as a toner and iron powder as a carrier. 
     A photoconductive drum having a selenium layer as a photosensitive member was subjected to charging and exposure by a conventional technique and developed with the above-prepared developing agent by a magnetic brush. The toner particles adhered to the image portion negatively charged. 
     P-tert-amyl phenol was mixed and ground with styrene butadiene latex, and polyvinyl pyrrolidone in water by a ball-mill. The resulting mixture was applied to a paper to form a coating of about 5 microns thick. The sheet thus formed was used as an image receiving sheet. The toner image on a selenium drum was transferred to the image receiving sheet, followed by subjecting to heat color forming fixing. The green image was obtained where a color forming fixing temperature was about 180° C., and color formation initiated at about 110° C. 
     EXAMPLE 3 
     Rhodamine in leuco-base (RL) was used as a toner, and iron powder as a carrier. The process was similar to that of Example 2, and the image receiving sheet was that of Example 1. The color forming fixing temperature was 180° C. to result in a red image. 
     EXAMPLE 4 
     Leuco-auramine was used as a toner, and iron powder as a carrier. The process of image forming was similar to that of Example 2. 
     An image receiving sheet was made from phenolic resin available as trade name, PP811 from Cunei Chemical Co., dissolved in xylol and a base paper. The color forming fixing temperature was about 180° C. to result in a sharp yellow image. 
     EXAMPLE 5 
     80 parts of Crystal Violet lactone (CVL) was dissolved in 20 parts of myristic acid, and fused. The melted mixture was poured into a shallow pan to cool and solidify. The material was ground in an attritor into a size of 1 - 50 microns, preferably, 5 - 20 microns. The particles over 325 mesh sieve was removed from the toner. To the thus sieved toner was added an iron powder at a ratio of 8 - 50 weight parts, preferably, 10 - 20 weight parts per one weight part of the toner. The iron particles were the range of 20 - 75 microns, preferably, 25 - 40 microns in size. The mixture of iron particles and the toner were introduced into a magnetic brush type developing apparatus. The whole surface of photoconductive zinc oxide was negatively charged, and exposed to a light pattern to form a latent image, which was developed by a developing apparatus. The toner particles adhered to the image portion negatively charged. The above formed toner image was transferred to an image receiving sheet having a coating made from a phenolic resin with a suitable binder. Then, heat color forming fixing was carried out. The toner comprising 80 parts of CVL and 20 parts of myristic acid can be fixed at about 110° C. while the toner comprising only CVL needed a temperature of about 180° C. 
     In the following examples, the toner was produced by a similar procedure of Example 4, to use for developing a latent image. 
     EXAMPLE 6 
     Toner: CVL 80 parts, palmitic acid 20 parts 
     Carrier: iron powder 
     Color forming fixing temperature: 110° C. 
     EXAMPLE 7 
     Toner: Malachite Green lactone (MGL) 50 parts, Stearic acid 50 parts 
     Carrier: iron powder 
     Color forming fixing temperature: 100° C. 
     EXAMPLE 8 
     Toner: benzoyl leuco methylene blue (BLMB) 95 parts, erucic acid 5 parts 
     Carrier: iron powder 
     Color forming fixing temperature: 110° C. 
     EXAMPLE 9 
     Toner: Leuco-auramine 50 parts, behenic acid 50 parts 
     Carrier: iron powder 
     Color forming fixing temperature: 130° C. 
     EXAMPLE 10 
     Toner: Rhodamine in leuco-base 50 parts, diacetone acryl amide (DAAM) 50 parts 
     Carrier: iron powder 
     Color forming fixing temperature: 90° C. 
     EXAMPLE 11 
     Toner: CVL 50 parts, ethylene glycol dibenzoate 50 parts 
     Carrier: iron powder 
     Color forming fixing temperature: 100° C. 
     EXAMPLE 12 
     Toner: Malachite Green lactone (MGL) 30 parts, dicyclohexyl phthalate (DCHP) 60 parts 
     Carrier: iron powder 
     Color forming fixing temperature: 110° C. 
     EXAMPLE 13 
     Toner: Crystal Violet lactone (CVL) 50 parts, Rhodamine in leuco-base 50 parts 
     Carrier: iron powder 
     Color forming fixing temperature: 180° C. 
     Color: purple 
     EXAMPLE 14 
     80 Parts of 8&#39;-methoxy indolino spiropyrane and 20 parts of stearic acid were mixed and fused. The fused mixture was poured into a pan to cool and solidify. The solidified material was crushed by a hammer mill crusher, and then ground by a jet mill into fine powder of a size having 1 - 50 microns, preferably, 5 - 20 microns. Iron powder was added to the thus formed toner at a ratio of 8 - 50 weight parts, preferably, 10 - 20 weight parts per one part of the toner. The iron powder was 20 - 75 microns, preferably, 25 - 40 microns in size. The mixture of iron powder and toner, i.e., the developing agent was introduced into a developing apparatus of magnetic brush type. The whole surface of photoconductive zinc oxide was negatively charged, and exposed to a light and dark pattern to form a latent image, which was developed by a developing apparatus. The toner adhered to the image portion negatively charged. 
     Then, the toner image thus formed was transferred to an image receiving sheet having a coating of phenolic resin with suitable binder. The heat color forming fixing was carried out. The toner comprising 80 parts of 8&#39;-methoxy indolino spiropyrane and 20 parts of stearic acid fixed at a temperature of about 110° C. to result in a dark blue image. 
     EXAMPLE 15 
     70 Parts of styrene resin (available as a trade name Piccolastic D-125 from Esso Standard Oil), 15 parts of stearic acid, 20 parts of Crystal Violet lactone (CVL) and 20 parts of Erogyl #200 (silica available from Nippon Erogyl) were mixed and fused, and then ground by a jet mill into a size below 5 microns to produce a toner. To 100 g. of the toner was added 1 l of Isopar H (trade name; petroleum solvent available from Esso Standard Oil), and ground for a period of 1.5 hours by means of an attritor, into particles having a size of 1 - 2 microns. To 50 ml. of this concentrated liquid was added 2 l of Isopar H and sufficiently ground to prepare a developing agent. 
     Following the electrophotographing process disclosed in Japanese Pat. Publication No. 23910/1967, a latent image was formed on an insulating layer and developed with the developing agent thus produced to form a toner image. 
     Styrene-butadiene copolymer latex 20 weight % as a binding agent, Dresinate X (available from Hercules Corp.) 0.3 weight % as an emulsifier, and phenolic aldehyde polymer (of fine particles of about 1 - 3 microns in size) 79.7 weight % as a color forming agent (B) were dispersed in water, and applied to a high quality paper to form a dried coating of 10 g. per square meter. On the formed receiving sheet was the powder image transferred, and heated at about 180° C. to completely fix the image on the sheet. The resultant image was blue and clear. This image could not be vanished even when rubbed with a rubber eraser. 
     EXAMPLE 16 70 Parts of styrene resin (trade name Piccolastic D-125 available from Esso Standard Oil, mp. 90°- 125° C.), 15 parts of palmitic acid and 20 parts of Rhodamine lactone (available from Hodogaya Chemical Co., Ltd.) were mixed and ground in a vibrating mill crusher. The mixture was uniformly melted, followed by cooling to solidify. The solid mixture was crushed by hammer mill crusher, and ground with a jet mill crusher into the particles of the size of 1 - 50 microns, preferably, 5 - 20 microns. To the afforded powder, i.e., the toner, was added iron powder i.e. a carrier and mixed at a ratio of 3 - 30 weight parts, preferably, 5 - 10 weight parts per one part of the toner. The carrier was 20 - 75 microns, preferably, 25 - 50 microns in particle size. In the mixture of the carrier and the toner, that is, in the developing agent, the carrier was positively charged and the toner was negatively charged. 
     To a polyethylene terephthalate film (100 microns thick) undercoated with gelatine was applied a quaternary ammonium polymer (trade name CP-261, available from Calgon Corp.) to impart conductivity, and sufficiently dried. Further, to this coating was applied a 5% solution of polyvinyl carbazole in monochlorobenzene solvent sensitized with Crystal Violet by a roller to form a photoconductive coating. Still further, an 8% solution of polyvinyl carbazole 10 parts and phenolic aldehyde polymer 8 parts in monochlorobenzene solvent was applied to the photoconductive film thus formed by a roller to form a coating of 4 - 6 g. per square meter. 
     The photoconductive film was uniformly charged with a corona discharger, and then, exposed to a light pattern to form a latent image, which was developed by the toner. The afforded powder image was melt-heated to result in a red and complete image. This image was appropriate for an overhead projector. 
     EXAMPLE 17 
     70 Parts of styrene resin (trade name Piccolastic D-125, available from Esso Standard Oil; softing point 90°- 125° C.), 15 parts of myristic acid and 20 parts of Malachite Green lactone (MGL) were mixed and ground in a vibrating mill crusher. The mixture was uniformly melted to cool into solid. The solid mixture was crushed by a hammer crusher, and then, ground with a jet mill crusher into the particles of 1 - 50 microns, preferably, 5 - 20 microns in size. To the produced fine powder, that is, the toner, was added iron powder, that is, a carrier at a ratio of 3 - 30 weight parts, preferably, 5 - 10 weight parts per one part of the toner. The carrier was 20 - 75 microns, preferably 25 - 50 microns in particle size. In the mixture of the carrier and the toner, that is, in the developing agent, the carrier was positively charged and the toner negatively charged. 
     The latent image produced on an insulating layer by the electrophotographic process disclosed in Japanese Pat. Publication No. 24748/1968 was developed with the developer produced above by means of magnetic brush technique to form a toner image. 
     Styrene butadiene copolymer latex 20 weight % as a binder, Dresinate X (available from Hercules Corp.) 0.3 weight % as an emulsifier and rosin-modified maleic acid polymer (fine powder) 79.7 weight % as a color-forming agent (B) were dispersed in water, and the dispersion mixture was applied to a high quality paper of 50 - 60 g./m 2  to form a dried coating of 10 g. per square meter. To the receiving sheet thus produced was transferred the powder image and heated at a temperature of about 180° C. to result in a green sharp image with complete fixation. The resultant image was not erased when rubbed vigorously with a rubber eraser. 
     EXAMPLE 18 
     70 Parts of styrene resin (trade name, Piccolastic D-125, available from Esso Standard Oil; softening point 90°- 125° C.), 15 parts of stearic acid, 9 parts of Crystal Violet lactone (CVL), 8 parts of Rhodamine lactone (RL), 8 parts of Malachite Green lactone (MGL) and 9 parts of leuco auramine were mixed and ground in a vibrating mill crusher. The mixture was uniformly melted and cooled to solidify. 
     The solid mixture was crushed by a hammer mill crusher, and then, ground by a jet mill grinder into a particle size of 1 - 50 microns, preferably, 5 - 20 microns. To the afforded fine powder was added an iron powder i.e. a carrier at a ratio of 3 - 30 weight parts, preferably, 5 - 10 weight parts per one weight part of the toner. The carrier was 20 - 75 microns, preferably 25 - 50 microns in particle size. In this mixture of the carrier and the toner, that is, in the developing agent, the carrier was positively charged and the toner negatively charged. 
     The electrostatic latent image produced by charging uniformly a photoconductive surface of selenium deposited on an aluminum plate and exposing the surface to a light pattern was developed by the developer thus produced to form a toner image. The toner image was transferred to a transferring sheet which was made by the process wherein 10 parts of ethylene maleic anhydride copolymer hydrolyzed product was dissolved in 100 parts of methyl ethyl ketone, the mixture was permeated into a high grade paper to incorporate at a ratio of 5 g./m 2 . The sheet was heated to form color in the portion to which the toner image was transferred. The resultant image was blue sharp with complete fixing. The resultant image was not vanished even when rubbed strongly with a rubber eraser. 
     EXAMPLE 19 
     70 Parts of styrene-methyl ester of acrylate copolymer (in a molar ratio of 6 : 4) (softening point 100°- 130° C.), 15 parts of montanic acid, and 20 parts of Crystal Violet lactone (CVL) were mixed and ground by a vibrating mill grinder. The mixture was sufficiently fused and cooled to solidify. The solid material was crushed by a hammer mill crusher and ground by a jet mill grinder into the particle size of 1 - 50 microns, preferably, 5 - 20 microns. To the resulting toner was added an iron powder, i.e., carrier at a ratio of 3 - 30 weight parts, preferably, 5 - 10 weight parts per one part of the toner. The carrier was 20 - 75 microns, preferably, 25 - 50 microns in a particle size. The carrier was positively charged and the toner negatively charged in the mixture of carrier and toner, i.e., a developing agent. 
     A corona charge was applied uniformly to a photoconductive member prepared by depositing selenium on an aluminum plate, nd then the member was exposed to a light pattern to form an electrostatic latent image, which was developed with the above produced developing agent to form a toner image. The toner image was transferred on a transferring sheet which was prepared by the process wherein 10 parts of ethylene-maleic anhydride copolymer hydrolyzed product was dissolved in 100 parts of methyl ethyl ketone, and the solution soaked in a high grade paper at the ratio of 5 g./m 2 . The transferring sheet was heated at about 180° C. to form blue color in the portion where the toner image was transferred. The resultant copy was clear and completely fixed. The resultant image was not vanished when rubbed strongly with an eraser. 
     EXAMPLE 20 
     Seventy parts of copolymer of styrene - maleic acid - methyl ester of acrylate (6:1.5:2.5 mole, softening point 95°-  C.), 20 parts of stearic acid and 20 parts of Crustal Violet Lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground a jet mill grinder until the particle size became 1 - 50 microns. preferably 5 - 20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3 - 30 weight parts, preferably 5 - 10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20 - 75 microns, preferably 25 - 50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor composed of selenium vacuum deposited on an aluminum plate was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of carboxy polyethylene polymer hydrolyzed product (a finely divided material) as a color forming agent (B) in water on a high grade paper (50 - 60 g./m 2 ) until the weight of a dried solid of the said material became 5 g., was heated at about 140° C. and a portion to which the toner image was transferred formed blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing. 
     EXAMPLE 21 
     Seventy parts of copolymer resin of vinyl chloride and vinyl acetate (in a ratio of 91 molar % and 9 molar %) 30 parts of stearic acid and 20 parts of Crystal Violet Lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground a jet mill grinder until the particle size became 1 - 50 microns, preferably 5 - 20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3 - 30 weight parts, preferably 5 - 10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20 - 75 microns, preferably 25 - 50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor layer composed of ZnO - binder was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadiene copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 797 weight % of vinyl methyl ether - maleic anhydride copolymer hydrolyzed product (a finely divided material) as a color forming agent (B) in water on a high grade paper (50 - 60 g/m2) until the weight of a dried solid of the said material became to 7 g., was heated at about 180° C. and a portion to which the toner image was transferred formed blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing. 
     EXAMPLE 22 
     Seventy parts of vinyl chloride-propylene copolymer (70:30 molar %), 20 parts of lacceric acid and 30 parts of Crystal Violet Lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1 - 50 microns, preferably 5 - 20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3 - 30 weight parts, preferably 5 - 10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20 - 75 microns, preferably 25 - 50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     1.0 Part of acrylic resin, 4 parts of zinc oxide and 2 parts of phenol-aldehyde polymer were dispersed together with xylene-toluene (50:50) mixture solvent in a ball mill for a period of 24 hours, further the addition of the above solvent until the viscosity of 80-100 c.p. to form a coating liquid. The coating liquid was applied to ZnO-acrylic resin sheet to form a coating of 4 - 5 g/m 2 . A corona charging was applied to this ZnO sheet, further exposed to a light pattern to form an electrostatic latent image, which was developed with the above toner. The obtained powder image was heated at the temperature of about 180° to result in a blue image with complete fixing. 
     EXAMPLE 23 
     Seventy parts of styrene resin (Piccolastic D-100 manufactured by ESSO Standard Oil Co.) 15 parts of stearic acid and 30 parts of 8&#39;-methoxy indolino spiropyrane were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 30-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on the insulating layer by the electrophotography process disclosed in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent by means of magnetic brush technique to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of carboxy polyethylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became to 15 g., was heated at about 180° C. and a portion to which the toner image was transferred formed dark blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing. 
     EXAMPLE 24 
     Seventy parts of styrene resin (Piccolastic D-100 manufactured by ESSO Standard Oil Co.), 15 parts of lacceric acid and 20 parts of 6.6&#39;-diamino spire (phthalane 1.9&#39; xanthene) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by the electrophotography process disclosed in Japanese Pat. Publication No. 23910/1967 was developed by means of magnetic brush technique by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing a solution of 10 parts of phenol-acetylene polymer in 100 parts of methyl ethyl ketone, in a ratio of 5 g/m 2  on a high grade paper was heated at about 195° C. and a portion to which the toner image was transferred formed red color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with an eraser. 
     EXAMPLE 25 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of lauric acid and 20 parts of 1.1-bis (p-aminophenyl) pathalan were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photo-conductor composed of selenium vacuum deposited on an aluminum plate was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadiene copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of carboxy polyethylene polymer hydrolyzed product (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60) g/m 2 ) until the weight of a dried solid of the said material became to 10 g., was heated at about 160° C. and a portion to which the toner image was transferred formed purple color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with an eraser. 
     EXAMPLE 26 
     Employing the process of Example 15, but substituting for Crystal Violet Lactone (CVL) each N-(2,5-dichrophenyl) leuco auramine, N-acetyl auramine, and dianisylidene acetone, there were obtained the similar result to Example 15. 
     EXAMPLE 27 
     Employing the process of Example 15, but substituting for styrene resin, each vinyl chloride resin, vinylidene chloride resin, polyethylene, polypropylene, epoxy resin, the toner chargable negatively was produced. There were obtained the similar results to Example 15. 
     EXAMPLE 28 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of lead caprylate and 20 parts of Crystal Violet Lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by an electrophotography process disclosed in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent by means of magnetic brush technique, to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadiene copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 797 weight % of carboxy polyethylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 10 g., was heated at about 190° C. and a portion to which the toner image was transferred formed blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing. 
     EXAMPLE 29 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of aluminum stearate (mp. 105° C.) and 20 parts of Rhodamine lactone were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by the electrophotography process disclosed in Japan Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent by means of a magnetic brush technique to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of carboxy polyethylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 10 g., was heated at about 195° C. and a portion to which the toner image was transferred formed red color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing. 
     EXAMPLE 30 
     Seventy parts of styrene resin (Piccolastic D-125 manufactured by ESSO Standard Oil Co.), 15 parts of lead laurate and 20 parts of Malachite Green Lactone were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75  microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by the electrophotography process disclosed in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent by means of magnetic brush technique to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of rosin modified maleic acid polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 5 g., was heated at about 170° C. and a portion to which the toner image was transferred formed green color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with a rubber eraser. 
     EXAMPLE 31 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of lead caprylate, 20 parts of Crystal Violet Lactone (CVL) and 10 parts of Erogyl (trade name, available from Nippon Erogyl Corp.) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size was below 5 microns. 
     100 G. of this toner was sufficiently ground in 1l of Isoper H by an atomizer into the particle size of 1-2 microns. This concentrated liquid was sufficiently dispersed in 2l of Isoper H to prepare a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by the electrophotography process disclosed in Japanese Pat. Publication No. 24748/1968 was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadiene copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of styrene-maleic anhydride copolymer hydrolyzed produce (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 8 g., was heated at about 170° C. and a portion to which the toner image was transferred formed blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with a rubber eraser. 
     EXAMPLE 32 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of lead enanthylate and 20 parts of Crystal Violet Lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75  microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor composed of selenium vacuum deposited on an alminium plate was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating of a composition obtained by dispersing 20 weight % of styrene butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of ethylene maleic anhydride copolymer hydrolyzed product (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 10 g., was heated at about 180° C. and a portion to which the toner image was transferred formed blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with a rubber eraser. 
     EXAMPLE 33 
     Seventy parts of styrene resin (Piccolastic D-100,  manufactured by ESSO Standard Oil Co.), 10 parts of beryllium stearate (mp. 45° C.) 20 parts of Crystal Violet Lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor composed of selenium vacuum deposited on an alminium plate was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of carboxy polyethylene polymer hydrolyzed product (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 7 g., was heated at about 190° C. and a portion to which the toner image was transferred formed blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with a rubber eraser. 
     EXAMPLE 34 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 30 parts of leau palmitate (mp. 112° C.) and 20 parts of Rhodamine lactone (RL, available from Hodogaya Chemical Co., Ltd.) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75  microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconducting layer of ZnO-binder was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of vinyl methyl ether - maleic anhydride copolymer hydrolyzed product (a finely divided material, about 1-3 microns) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 10 g., was heated at about 185° C. and a portion to which the toner image was transferred formed red color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with a rubber eraser. 
     EXAMPLE 35 
     Seventy parts of vinyl chloride-propylene copolymer, 20 parts of Crystal Violet lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One wight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by means of the electrophotography process disclosed in Japan Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of phenol-acetylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 3 g., was heated at about 180° C. and a portion to which the toner image was transferred formed blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with a rubber eraser. 
     EXAMPLE 36 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of lead tridecylate and 30 parts of 8&#39;-methoxy indolino spiropyran were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by the electrophotography process disclosed in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent by means of magnetic brush technique, to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of carboxy polyethylene polymer product (a finely divided material as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 10 g., was heated at about 180° C. and a portion to which the toner image was transferred formed dark blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with a rubber eraser. 
     EXAMPLE 37 
     70 Parts of styrene resin Piccolastic D-125), 15 parts of lead palmitate, 20 parts of 6,6&#39;-diamino spiro (phthalan 1,9&#39;-(xanthene) and 10 parts of Erogyl -200 (trade name, silica available from Nippon Erogyl Corp.) were mixed and grounded by a vibration mill grinder. The mixture was uniformly fused and cooled to solidify. The solidified material was crushed by a hammer mill, and then ground by a jet mill grinder into the particle size below about 5 microns. The toner 100 g. was mixed uniformly and with 1 l. of Isopar H (trade name) in an attrator, into the toner particle size of 1-2 microns. This concentrated liquid 50 ml. was uniformly dispersed and in 2 l. of Isapar H (trade name) to prepare a developing agent. 
     A polyethylene terephthalate film undercoated with gelatine (100 microns thick) was subjected to a conducting treatment with a quaternary ammonium polymer (available as trade name CP-261 from Calgon Corp.) 
     An 8% solution of brominated polyvinyl carbazole and phenol acetone polymer at a ratio of 10 parts and 7 parts, in a monochlorobenzone was applied on the conductized coating layer by a roller to form an additional coating of about 3-4 g/m 2 . 
     The photoconductive film was charged by a corona discharging, and then, exposed to a light pattern to form an electrostatic latent image, which was developed by the toner thus formed. The toner image obtained was heated to result in a red image with complete fixing. The resultant image was not vanished when rubber strongly with a rubber eraser. 
     EXAMPLE 38 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of lead caprylate, and 20 parts of 1,1-bis (p-aminophenyl) phthalan were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size beame 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor composed of selenium vacuum deposited on an alminium plate was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of carboxy polyethylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became to 10 g., was heated at about 180° C. and a portion to which toner image was transferred formed purple color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with a rubber eraser. 
     EXAMPLE 39 
     Employing the process of Example 28, but substituting for Crystal Violet lactone (CVL), each N-(2,5-dichlorophenyl) leuco-auramine, N-acetylauramine, and dianisylidene acetone, there were obtained a similar result to Example 28. 
     EXAMPLE 40 
     Employing the process of Example 28, but substituting for styrene resin, each vinyl chloride resin, vinylidene chloride resin, polyethylene, polypropylene. epoxy resin and vinsol resin, the negative chargable toner was produced. There were obtained a result similar to Example 28. 
     EXAMPLE 41 
     70 parts of styrene resin (available as a trade name, Piccolastic D-125, from ESSO Standard Oil), 15 parts of glycerine ester of stearic acid (mp. 72° C.), 20 parts of Crystal Violet lactone (CVL) and 5 parts of Erogyl (trade name, silica available from Nippon Erogyl) were mixed and ground by a vibrating mill grinder. The mixture was uniformly melted and cooled to solidify. The solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder into the particle size below 5 microns. 
     100 G. of the formed toner was mixed with 1 l. of Isopar H by an attrator. This concentrated liquid was dispersed in 2 l. of Isopar H to prepare a developing agent. 
     An electrostatic latent image on an insulating layer, obtained by the process disclosed in Japan Pat. Publication No. 23910/1967 was developed by the developing agent obtained above, to form a toner image. The toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadiene copolymer latex as a binder, 0.3 weight % of Dresinate X (trade name, manufactured by Hercules) as an emulsifier, and 79.7 weight % of phenol aldehyde polymer (a finely divided material of about 1-3 microns) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) to form a dried coating of 8 g. per square meter. 
     The transferred image was heated at about 180° C. to result in a blue clear image on the portion where the toner image was transferred. The resultant image was not vanished when rubbed vigorously with a rubber eraser. 
     EXAMPLE 42 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of glycole ester of stearic acid (m.p. 75° C.) and 20 parts of Rhodamine lactam were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e., toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by the process disclosed in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent by means of magnetic brush technique to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of phenol acetylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 15 g., was heated at about 180° C. and a portion to which the toner image was transferred formed red color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with a eraser. 
     EXAMPLE 43 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of methyl beneate and 20 parts of Malacoite Green lactone were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused anc cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (I.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by electrophotography process disclosed in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent by means of magnetic brush technique, to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of rosin modified maleic acid polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 10 g., was heated at about 170° C. and a portion to which the toner image was transferred formed green color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with a rubber eraser. 
     EXAMPLE 44 
     70 parts of styrene resin (available as trade name, Piccolastic D-125 from ESSO Standard Oil), 15 parts of ethyl benenate, 20 parts of Crystal Violet lactone (CVL) and 10 parts of Aerosil #200 (trade name, silica available from Nippon Aerosil) were mixed and ground by a vibrating mill grinder. 
     The mixture was uniformly fused and cooled to solidify. 
     the solid material was crushed by a hammer mill crusher, and then ground by a jet mill grinder into the toner particle size below 5 micron. 
     100 G. of the toner was sufficiently ground with 1 l. of Isopar H by an attrator to form a concentrated developing liquid containing toner of 1-2 micron in size. this concentrated liquid was dispersed in 2 l. of Isopar H to prepare a developing agent. 
     A polyethylene terephthalate film (100 micron thick) undercoated with gelatine was subjected to a conductizing treatment with quaternary ammonium polymer (available as trade name, CP-261, from Calgon Corp.), and sufficiently dried. 
     A 5% solution of polyvinylcarbazole sensitized with Crystal Violet in monochlorobenzene was additionally applied to the sheet to form a photoconductive coating. Further, to this photoconductive sheet was a 6% solution of chlorinated polyvinylcarbazole 10 parts, styrene maleic anhydride copolymer hydrolyzed product 8 parts in monochlorobenzene applied by a roller to form a coating of 4-6 g/m 2 . This photoconductive sheet was uniformly charged by corona discharging, and exposed to a light pattern to form an electrostatic latent image, which was developed by the toner. The obtained toner image was heated to result in a blue image with complete fixture. The resultant image could not be vanished when rubbed with a eraser. 
     EXAMPLE 45 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of phenyl arachate and, 20 parts of Crystal Violet Lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor composed of selenium vacuum deposited on an aluminium plate was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of ethylene-maleic anhydride copolymer hydrolyzed product (a finely divided material) as a color forming agent (B) in water on a high grade paper(50-60 g/m2) until the weight of a dried solid of the said material became to 7 g., was heated at about 180° C. and a portion to which the toner image was transferred formed blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with an eraser. 
     EXAMPLE 46 
     70 parts of styrene resin (Piccolastic D-100, available from ESSO Standard Oil Co.), 30 parts of glycol stearate (mp. 75° C.) and 20 parts of Crystal Violet lactone (CVL) were mixed and ground in a vibrating mill crusher. The mixture was uniformly melted and cooled into solid. 
     The solid material was crushed by a hammer mill crusher, and then ground by a jet mill grinder into the particle size of 1-50 microns, preferably, 5-20microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image was produced on a photoconductive member by uniform corona-charging and applying a light pattern to the photoconductive member composed of selenium vacuum deposited on an aluminium plate. 
     A solution of carboxy polyethylene polymer hydrolyzed product 5 parts, and polyvinyl butylate 5 parts in 100 parts of methyl ethyl ketone was applied to a base paper undercoated of 3 g/m2 with 2% aqueous solution of sodium alginate, to form a coating of 7 g/m2, 
     The thus produced latent image was transferred to the electrostatic recording paper above produced, and developed by the above developing agent. 
     The toner image was heated at about 180° C. to form blue color. The resultant image was clear with complete fixture. The image could not be vanished at all when rubbed strongly with an eraser. 
     EXAMPLE 47 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 10 parts of glycole stearate (mp. 75° C.) and 20 parts of Rhodamine lactone (available from Hodogaya Chemical Co., Ltd.) were mixed and ground by a vibratng mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor layer comprising ZnO-binder was developed by the above mentioned developing agent to form a toner iage. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of vinyl methyl ether - maleic anhydride copolymer hydrolyzed product (a finely divided material of about 1-3 micron in size) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became to 10 g., was heated at about 185° C. and a portion to which the toner image was transferred formed red color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with an eraser. 
     EXAMPLE 48 
     Seventy parts of vinyl chloride-propylene (70 : 30 molar %) copolymer, 20 parts of glycol palmitate and 20 parts of Crystal Violet Lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground a jet mill grinder until the particle size become 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75  microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by the electrophotography process disclosed in Japanese Patent Publication No. 23910/1967 was developed by the above mentioned developing agent by means of magnetic brush technique to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of phenolacetylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became to 10 g., was heated at about 180° C. and a portion to which the toner image was transferred formed blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with an eraser. 
     EXAMPLE 49 
     Seventy parts of styrene resin (Piccolastic D-100, manufactured by ESSO Standard Oil Co.), 15 parts of ethyl arachate and 30 parts of 8&#39;-methoxy indolino spiropyran were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by the electrophotography process disclosed in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent by means of magnetic brush technique to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of carboxy polyethylene polymer hydrolyzed product (a finely divided material) as a color forming agent (B) in water on a high grade paper(50-60 g/m2) until the weight of a dried solid of the said material became to 10 g., was heated at about 180° C. and a portion to which the toner image was transferred formed dark blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with an eraser. 
     EXAMPLE 50 
     Seventy parts of styrene resin (Piccolastic D-125,  manufactured by ESSO Standard Oil Co.), 15 parts of phenyl palmitate and 20 parts of 6,6&#39;-diamino spiro (pathalan 1,9&#39;-xanthene were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by the electrophotography process disclosed in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent by means of magnetic brush technique to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copoymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of phenol acetylene polymer (a finely divided material of about 1-3 micron in size) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became to 10 g., was heated at about 195° C. and a portion to which the toner image was transferred formed red color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with an eraser. 
     EXAMPLE 51 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of methyl melissinate and 20 parts of 1,1-bis (p-aminophenyl) phthalan were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor composed of selenium vacuum deposited on an aluminium plate was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of carboxy polyethylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became to 10 g., was heated at about 160° C. and a portion to which the toner image was transferred formed purple color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with an eraser. 
     EXAMPLE 52 
     Employing the process of Example 41, except of using, each, N-(2.5-dichlorophenyl) leuco-auramine, N-acetyl auramine, dianisylidene acetone in place of Crystal Violet lactone (CVL), there were obtained the results similar to Example 41. 
     EXAMPLE 53 
     Employing the process of Example 41, except of using each vinyl chloride, vinyldene chloride, polyethylene, polypropylene, epoxy resin, and vinsol resin in place of styrene resin, there was produced the toner negatively chargeable. There was obtained a result similar to Example 41. 
     EXAMPLE 54 
     Seventy parts of styrene resin (Piccolastic D-100, manufactured by ESSO Standard Oil Co.), 15 parts of lauric amide 20 parts of Crystal Violet Lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidfy. 
     The said solidified material was crushed by a hammer mill crusher, and then ground a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic laten image obtained on an insulating layer by the electrophotography process disclosed in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of phenol aldelyde polymer (a finely divided material of about 1-3 micron in size) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became to 6 g., was heated at about 205° C. and a portion to which the toner image was transferred formed blue color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with an eraser. 
     EXAMPLE 55 
     Seventy parts of styrene resin (Picoolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of lauric anilide and 20 parts of Rhodamine lactone were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained on an insulating layer by the electrophotograhy process disclosed in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent by means of magnetic brush technique to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of phenol acetylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became to 10 g., was heated at about 180° C. and a portion to which the toner image was transferred formed red color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing with an eraser. 
     EXAMPLE 56 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by ESSO Standard Oil Co.), 15 parts of lauric methyl amide, 20 parts of Malachite Green lactone and 10 parts of Erogyl #200 (trade name, silica available from Nippon Erogyl) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. 
     The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder into the toner particle size below 5 microns. 
     100 G. of the toner was mixed and ground with 1 l of Isopar H by an attritor to prepare a concentrated developing liquid containing the toner of 1-2 microns in size. This liquid 50 ml. was dispersed in 2 l of Isopar H to prepare a developing agent. 
     To a base paper undercoated with an aqueous 2% solution of sodium alginate at a ratio of 3 g/m 2  was a liquid comprising 5 parts of rosin modified maleic acid polymer, 5 parts of polyvinyl butylate and 100 parts of methyl ethyl ketone applied to form a coating of 7 g/m 2 . 
     On the obtained electrostatic recording paper was the electrostatic latent image obtained on an insulating layer by the electrophotography process disclosed in Japanese Pat. Publication No. 23910/1967, transferred, and developed by the developing agent produced as above. The afforded toner image was heated to form green color to result in a clear copy with complete fixing. The resultant image was not vanished when rubbed strongly with an eraser. 
     EXAMPLE 58 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by Esso Standard Oil Co.), 15 parts of stearic acid amide, 20 parts of Crystal Violet Lactone (CVL), and 10 parts of Erogyl #200 (Silica powder, manufactured by Nippon Erogyl Co.) were mixed and ground by a vibrating mill grinder. The resulting mixture was sufficiently fused and cooled to solidify. The solidified material was crushed by a hammer mill crusher and then ground by a jet mill grinder until a particle size became less than 5 microns to form a toner. The concentrated developing liquid containing a toner of 1-2 microns of the particle size was produced by mixing sufficiently 100 g. of the toner and 1 liter of Isopar H, a developing liquid was prepared by dispersing 50 ml. of the concentrated developing liquid in 2 liter of Isopar H. 
     Then, the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor composed of selenium vacuum deposited on an aluminium plate was developed by the above mentioned developing agent to form a toner image. The toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadienecopolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of the hydrolyzed product of ethylene-maleic anhydride copolymer (finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became 10 g/m2, and was heated at about 200 deg. C, and the portion to which the toner image was transferred formed blue color, and as the result a completely fixed clear copy was obtained. 
     EXAMPLE 59 
     Seventy parts of styrene resin (Piccolastic D-100, manufactured by Esso Standard Oil Co.), 30 parts of Crystal Violet Lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder i.e. carries. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then, the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor composed of selenium vacuum deposited on an aluminium plate was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of carboxy polyethylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became to 10 g/m2 , was heated at about 190 deg. C and a portion to which the toner image was transferred formed blue color, and as the result, a completely fixed clear copy was obtained. The image was not vanished at all by strong rubbing. 
     EXAMPLE 60 
     Seventy parts of styrene resin (Piccolastic D-125, manufactured by Esso Standard Oil Co.), 70 parts of caprylicmethyl amide (m.p. 57 deg. C) and 20 parts of Rhodamine Lactone (RL, manufactured by Hodogaya Kagaku Co.) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of said fine powder (i.e. toner) ws mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor of ZnO-binder system was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of the hydrolyzed product of vinyl methyl ether-moleic anhydride (a finely divided material, particle size 1-8 microns) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became to 10 g., was heated at about 180 deg. C and a portion to which the toner image was transferred formed red color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing. 
     EXAMPLE 61 
     Seventy parts of vinyl chloride-propylene copolymer (70:30 mol %), 70 parts of palmitic amide, and 20 parts of Crystal Violet Lactone (CVL) were mixed and ground by a vibrating mill grinder. The said mixer was sufficiently fused and cooled to solidify. The solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) ws mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. developing agent. 
     Then the electrostatic latent image on an insulating layer obtained by an electrophtographic process mentioned in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent and a magnetic brushing technic to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of phenol acetylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 10 g., was heated at about 180 deg. C and a portion to which the toner image was transferred formed violet color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing. 
     EXAMPLE 62 
     Seventy parts of styrene resin (Piccolastic D-125), 15 parts of behenic amide, and 30 parts of 8&#39;-methoxy indolins spiropyrane were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. The said solidified material was crushed by a hammer mill crusher and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the carrier and the toner, i.e. a developing agent. 
     Then the electrostatic latent image on an insulating layer obtained by an electrophotography process mentioned in Japanese Pat. Publication No. 28910/1967 was developed by the above mentioned developing agent and a magnetic brushing technic to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of the hydrolyzed product of carboxy polyethylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 10 g., was heated at about 180 deg. C and a portion to which the toner image was transferred formed bluish black color, and as the result, a completely fixed clear copy was obtained. 
     EXAMPLE 63 
     Seventy parts of styrene resin (Piccolastic D-125), 15 parts of palmitic anilide, and 20 parts of 6.6&#39;-diamins spiro (phthalan 1.9&#39;-Xanthene) were mixed and ground by a vibrating mill grinder. The said mixture was sufficiently fused and cooled to solidify. The said solidified material was crushed by a hammer mill crusher, and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier was positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image on an insulating layer obtined by an electrophotography process mentioned in Japanese Pat. Publication No. 23910/1967 was developed by the above mentioned developing agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of phenol acetylene polymer (a finely divided material, particle size 1-8 microns) as a color forming agent (B) in water on a high grade paper (50-60 g/m 2 ) until the weight of a dried solid of the said material became to 10 g., was heated at about 195 deg. C and a portion to which the toner image was transferred formed red color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing. 
     EXAMPLE 64 
     Seventy parts of styrene resin (Piccolastic D-125), 15 parts of caprylic anilide, and 20 parts of 1.1 bis (P-aminophenyl) phthalan were mixed and ground by a vibrating mill grinder. The said mixture ws sufficiently fused and cooled to solidify. The said solidified material was crushed by a hammer mill crusher and then ground by a jet mill grinder until the particle size became 1-50 microns, preferably 5-20 microns. 
     One weight part of the said fine powder (i.e. toner) was mixed with 3-30 weight parts, preferably 5-10 weight parts, of an iron powder, i.e. carrier. 
     The particle size of the said carrier is 20-75 microns, preferably 25-50 microns. 
     The carrier ws positively charged and the toner was charged negatively in the mixture of the said carrier and toner, i.e. a developing agent. 
     Then the electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor composed of selenium vacuum deposited on an aluminium plate was developed by the above mentioned deveoping agent to form a toner image. The said toner image was transferred to a transferring paper prepared by coating a composition obtained by dispersing 20 weight % of styrene-butadien copolymer latex as a binder and 0.3 weight % of Dresinate X (trade mark, manufactured by Hercules Co.) as an emulsifier and 79.7 weight % of carboxy polyethylene polymer (a finely divided material) as a color forming agent (B) in water on a high grade paper (50-60 g/m2) until the weight of a dried solid of the said material became 10 g., was heated at about 160 deg. C and a portion to which the toner image was transferred formed violet color, and as the result, a completely fixed clear copy was obtained. The said image was not vanished at all by strong rubbing. 
     EXAMPLE 65 
     N-(2.5-dichlorophenyl) lenco auramine, N-acetyl auramine or dianisylidene acetone was used in place of crystal violet in EXAMPLE 54, and the other procedures were the same as those of EXAMPLE 54. The result was the same as that of EXAMPLE 54. 
     EXAMPLE 66 
     Vinyl chloride resin, vinylidene chloride resin, polyethylene-polypropylene-epoxy resin or vinsol resin was used in place of styrene resin in EXAMPLE 54 and the other procedures were the same as those of EXAMPLE 54. As the result, negatively charged toner was obtained and other results were the same as those of EXAMPLE 54. 
     EXAMPLE 67 
     Fifty parts of phenol aldehyde polymer, 30 parts of stearic acid, 20 parts of styrene-butadiene latex (film forming agent), 150 parts of water and 0.4 parts of Dresinate X (emulsifier) were mixed and ground by a ballmill grinder for more than ten hours. A paper was coated with the resulting emulsion until the weight of a dried solid of the said emulsion became 10 g/m2, and was dried. The coated paper was cut in a suitable size and was used as a transferring sheet. 
     Fourty parts of 8&#39;-methoxyindolino spiropyrane and 60 parts of styrene resin (Piccolastic D-125, manufactured by Esso Standard Oil Co.) was fused and cooled to solidify. The said solidified material ws ground until the particle size became 1-30 microns, preferably 5-15 microns. 
     One part of the said fine powder (i.e. a toner) was mixed with iron powders of 3-30 parts, preferably 5-10 parts. 
     The particle size of a carrier was 20-75 microns, perferably 25-50 microns. 
     The carrier was positively charged and the toner was negatively charged in the developing agent which was the mixture of the carrier and the toner. 
     After the above mentioned developing agent was put in the magnetic brushing type developer, the toner image was transferred to a transferring sheet by the electrophotographic copying machine (NP-100, manufactured by Canon Co.) using the electrographic process mentioned in Japanese Pat. Publication No. 23910/1967, and color forming and fixing of the said toner image were held by the fixing machine shown in FIG. 3. The clear bluish black color copy was obtained at about 180 deg. C. This image was not vanished at all by strong rubbing. 
     EXAMPLE 68 
     The transferring sheet was produced by the same process as that of EXAMPLE 67 except adding phenolacetylene polymer (a color forming agent B) and 25 parts of myristic acid (a color forming auxiliary agent). 
     The toner was produced by treating 40 parts of Crystal Violet Lactone (CVL) and 60 parts of P-cyanostyrene-styrene polymer (cyanostyrene 4.3%, styrene 95.7%) (manufactured by Denki Kagaku Kogyo Co.) by the same process as that of EXAMPLE 67 and was arranged as a developing agent. 
     the carrier was positively charged and the toner was negatively charged in the developing agent of the carrier and the toner. 
     After the developing agent was put in the magnetic brushing type developer, the toner image was formed on the drum having a photosensitive layer by Canon NP process and was transferred to the transferring sheet. Color forming and fixing were held by the fixing machine, and a clear blue copy was obtained at about 160 deg. C. 
     EXAMPLE 69 
     The transferring sheet was produced by the same process as that of EXAMPLE 67 except adding 50 parts of rosin modified maleic acid (color forming agent B) and dibenzoic acid ethylene glycol (color forming auxiliary agent). 
     The toner was produced by treating 40 parts of Rhodamine Lactone (RL) and 60 parts of polyester resin (XPL 2005, manufactured by Kao Atlas Co.), by the same process as that of EXAMPLE 67. 
     The carrier was negativey charged and the toner was positively charged in the developing agent of the carrier and the toner. 
     After the above mentioned developing agent was put in the magnetic brushing type developing machine, as electrostatic latent image produced by applying negative electric charge to the surface of the drum having photoconductive ZnO and exposing through an original was developed by the above mentioned developing machine to form a toner image. The resulting toner image was transferred to the above mentioned transferring sheet. Color forming and fixing of the toner image was held by the above mentioned fixing machine. A clear red copy was obtained at about 190 deg. C. 
     EXAMPLE 70 
     The transferring sheet was produced by the same process as that of EXAMPLE 67 except adding parts of hydrolyzed product of styrene-maleic anhydride copolymer (color forming agent B) and 25 parts of diphenyl phthalate (color forming auxiliary agent). 
     The toner was produced by treating Leuco auramine (LA) in the same way as in EXAMPLE 67. 
     The carrier was negatively charged and the toner was postively charged in the developing agent of the carrier and the toner. 
     after the above mentioned developing agent was put in the magnetic brushing type developing machine, the electrostatic latent image formed by applying negative electric charge to the surface of the drum having photoconductive ZnO and by exposing through an original was developed by the above mentioned dveloping machine to form the toner image. The resulting toner image was transferred to the above described transferring sheet. Color forming and fixing was held by the above decribed fixing machine. A clear yellow copy was obtained at about 190 deg. C. 
     EXAMPLE 71 
     A transferring sheet was produced by the same process as in EXAMPLE 67 except adding 50 parts of phenol-aldehyde polymer (color forming agent B) and 25 parts of lacceric acid (color forming auxiliary agent). 
     The toner was produced by ehs ame process as in EXAMPLE 67 except using 40 parts of CVL and 60 parts of vinyl chloride resin (trade name, Denka Vinyl, manufactured by Denki Kaguku Kogyo Co.) as a dveloping agent. 
     The carrier was positively charged and the toner was negatively charged in the developing agent. 
     After the above mentioned developing agent was put in the magnetic brushing type developing machine, the electrostatic latent image was developed by Canon NP process on the surface of the photosensitive layer and then a toner image was transferred to the above described transferring sheet. Color forming and fixing of the toner image was held by the above described fixing machine, and a clear blue copy was obtained at about 200 deg. C. 
     EXAMPLE 72 
     A toner was produced by fusing 40 parts of 8&#39;-methoxyindolino spiropyrane and 60 parts of polystyrene (Piccolastic D-125), cooling and then grinding by a jet mill grinder until the particle size became 5-20 microns. 
     One part of the toner was mixed with 3-30 parts, preferably 5-10 parts of iron powder i.e. a carrier. The particle size of the carrier was 20-75 microns, preferably 25-50  microns. 
     The carrier was positively charged and the toner was negatively charged in the developing agent. 
     The electrostatic latent image formed on the insulated layer by the electrography process mentioned in Japanese Pat. publication No. 23910/1967 was developed by the above mentioned developing agent and the magnetic brushing technic to form a toner image. 
     Then, 50 parts of phenol aldehyde polymer, 30 parts of aluminum stearate, 150 parts of water, and 0.4 part of emulsifier (Daesinate X, manufactured by Hercules Co.) were mixed and ground by a ball mill for 24 hours. The toner image was transferred to a transferring paper which was coated with the emulsion until the weight of a dried solid of the emulsion became 10 g./m 2 , and was heated at about 180 deg. C. A portion to which the toner image was transferred formed bluish black color, and as the result, a completely fixed clear copy was obtained. The image was not vanished at all even by strong rubbing. 
     EXAMPLE 73 
     Fourty parts of Crystal Violet Lactone and 60 parts of p-cyanostyrene-styrene (P-cyanostyrene 4.8%, styrene 97.7%) were fused and cooled to solidify. The solidified material was ground by a jet mill grinder until the particle size became 5-20 microns. 
     One part of the said fine powder (i.e. a toner) and 3-30 parts, preferably 5-10 parts of iron powder (i.e. a carrier) were mixed. 
     Then the electrostatic latent image formed on an insulting layer by the electrophotographic process mentioned in Japanese Pat. Publication No. 23910/1967 was developed by the dveloping agent and a magnetic brushing technic and a toner image was formed. Further, 50 parts of phenol acetylene polymer, 25 parts of lead capronate, 20 parts of styrene-butadiene latex, 150 parts of water and 0.4 part of an emulsifier (trade name, Dresinate X, manufactured by Hercules Co.) were mixed by a ball mill for 24 hours. The toner image was transferred to a transferring paper which was coated with the said emulsion until the weight of the dried solid of the emulsion became 10 g./m 2 , and was heated to about 160 deg. C. A portion to which the toner image was transferred formed blue color, and as the result, a clear copy was obtained. The image was not vanished at all by strong rubbing. 
     EXAMPLE 74 
     Fourty parts of Rhodamine Lactone and 60 parts of Polyester resin (XPL 2005, manufactured by Kao Atlas Co.) were fused and cooled to solidify. The solidified material was ground by a jet mill grinder until the particle size became 5-20 microns. 
     One part of the fine powder (i.e. toner) and 3-30 parts, preferably 5-10 parts of iron powder (i.e. carrier) were mixed. 
     After the said developing agent was put in the magnetic brushing type developing machine, the electrostatic latent image formed by applying negative electric charge on the drum having photoconductive ZnO and by exposing through an original was developed by the dveloping machine to form the toner image. 
     Then, 50 parts of resin modified maleic acid, 25 parts of mono glycerol stearate, 20 parts of styrene-butadiene latex, 150 parts of water, and 0.4 parts of emulsifier (Dresinate X) were mixed and ground by a ball mill for 24 hours. 
     The said toner image was transferred to the transferring paper which was coated with the said emulsion until the weight of the dried solid became 10 g./m 2 , and was heated to 160 deg. C. As the result, a portion to which the toner image was transferred formed red color and a clear copy was obtained. The image was not vanished at all by strong rubbing. 
     EXAMPLE 75 
     Fourty parts of Leuco auramine and 60 parts of polystyrene (Piccolastic D-100) were fused and cooled to solidify. The solidified material was ground by a jet mill grinder until the particle size became 5-20 microns. 
     One part of the fine powder (i.e. a toner) was mixed with 3-30 parts, preferably 5-10 parts of iron powder (i.e. carrier). 
     Then the electrostatic latent image formed in an insuating layer by the electrogrpaphic process mentioned in Japanese Pat. Publication No. 23910/1967 was developed by the said devloping agent and magnetic brushing technic to form the toner image. Further, 50 parts of hydrolyzed product of styrene-maleic anhydride copolymer, 25 parts of methyl behenate, 20 parts of styrene-butadiene latex, 150 parts of water and 0.4 part of an emulsifier (Dresenate X) were mixed and ground by a ball mill for 24 hours. The toner image was transferred to the transferring paper which was coated with the emulsion at an amount of 10 g./m 2  (as solid), and heated to about 170 deg. C. As the result, a portion to which the toner image was transferred foremd yellow color, and a clear copy was obtained. The resulting image was not vanished at all by strong rubbing. 
     EXAMPLE 76 
     Fourty parts of 6.6&#39;-diaminospiro (phthalan-1.9&#39;-xanthene) and 60 parts of polyester resin were fused and cooled to solidify. The solidified material was ground by a jet mill until the particle size became 5-20 microns to form a toner. 
     Then 1.0 part of acrylic resin, 4 part of ZnO, 2 part of hydrolyzed product of carboxy polyethylene polymer and mixed solvent of xylene and toluene (50:50) were mixed and dispersed by a ball mill for 24 hours, and furthermore the solvent was added until the viscosity of the solution became 80-100 cp. The paper of ZnO-acrylic resin system was coated with the soltuion at an amount of 4-5 g./m 2 . 
     The electrostatic latent image obtained by corona-charging and applying a light pattern to a photoconductor of ZnO-binder system was developed by the toner to form a toner image. The toner image was fixed at 200 deg. C., and formed red color to obtain a clear copy. 
     EXAMPLE 77 
     Fourty of 1.1-bis (aminophenyl phthalan) and 60 parts of epoxy resin were fused and cooled to solidify. The solidified material was ground by a jet mill until the particle size became 5-20 microns. 
     One part of the fine powder (i.e. a toner) and 3-30 parts, preferably 5-10 parts of iron powder (i.e. a carrier) were mixed. 
     Then the electrostatic latent image formed on an insultaing layer by the electrostatic process mentioned in Japanese Pat. Publication No. 23910/1967 was developed by the said developing agent and the magnetic brushing technic to form a toner image. 
     Fifty parts of hydrolyzed product of vinyl methyl ether-maleic anhydride copolymer 25 parts of myristic acid anilide, 20 parts of styrene-butadiene (Dow 636, film forming agent), 150 parts of water and 0.4 parts of an emulsifier (Dresinate X) were mixed and ground by a ball mill for 24 hours. The toner image was transferred to the transferring paper which was coated with the emulsion at an amount of 10 g./m 2  (as solid) and was heated to about 180 deg. C., and as the result, a portion to which the toner image was transferred formed red color to obtain a clear copy. The resulting image was not vanished at all by strong rubbing. 
     EXAMPLE 78 
     
         ______________________________________                                    
Malachite Creen Lactam                                                    
                  40 parts by weight                                      
Polystyrene (trade name,                                                  
                  60 parts by weight                                      
 riccolastic B-125                                                        
______________________________________                                    
 
    
     A mixture of the above components were melted and cooled to solidify. The resulting solid matter was crushed by a hammer mill crusher and then ground by a jet mill grinder until the particle size became 1 - 50 microns, preferred with 5 - 20 microns. One part by weight of the resulting fine powder, i.e. toner, was mixed with 3 - 30 parts by weight, preferred with 5 - 10 parts by weight, of iron powder, i.e. carrier. Particle size of the carrier was 20 - 75 microns, preferred with 25 - 50 microns. 
     A photoconductive member composed of an aluminum plate having a vapor-deposited selenium was uniformly corona-charged and exposed to a light pattern to obtain an electrostatic latent image, followed by developing with the above mentioned developer to form a toner image. 
     50 Parts by weight of hydrolyzed product of ethylene-maleic anhydride copolymer, 25 parts by weight of lauric methylamide, 20 parts by weight of styrene-butadiene latex (film shaping agent), 150 parts by weight of water and 0.4 parts by weight of emulsifier (trade mark, Dresinate X) were mixed and ground by a ball mill for 24 hours. The resulting emulsion liquid was coated on a paper at an amount of 10 g./m 2 , to form a transferring paper. The toner image as obtained above was transferred to the transferring paper and heated at about 170° C. to form a sharp green copy at the portion to which the toner image was transferred. The resulting colored image was not vanished at all by rubbing. 
     EXAMPLE 79 
     
         ______________________________________                                    
N-(2,5-dichlorophenyl) leuco auramine                                     
                     40 parts by weight                                   
Polystyrene          60 parts by weight                                   
______________________________________                                    
 
    
     The mixture of the above two components was mixed, melted, cooled, and crushed by a jet mill crusher to a particle size of 5 - 20 microns to form a toner. 
     One part by weight of the resulting fine powder toner was mixed with 3 - 30 parts by weight, preferred 5 - 10 parts by weight of iron powder carrier. 
     An electrostatic latent image on an insulating layer produced by an electrophotographic method of Japanese Pat. Publication No. 23910/1967 was developed with a developer by a magnetic brush method. 
     Diatomaceous earth 50 parts by weight, stearic dodecylamide 25 parts by weight, styrene-butadiene latex (film forming agent) 30 parts by weight, water 150 parts by weight, and emulsifier (trade name, Dresinate X) 0.4 parts by weight were mixed and ground for 24 hours by a ball mill. The resulting emulsion liquid was coated on a paper at an amount of 10 g./m. 2  (as solid) to form a transferring paper, and the toner image obtained above was transferred thereto and heated at about 200° C. to produce a colored image at a portion to which the toner image was transferred. The resulting colored image was not vanished when rubbed strongly with a eraser. 
     EXAMPLE 80 
     
         ______________________________________                                    
N-Acetyl auramine  40 parts by weight                                     
Vinyl chloride-propylene                                                  
                   60 parts by weight                                     
 copolymer (70:70 mole %)                                                 
______________________________________                                    
 
    
     The above components were mixed, melted, cooled and crushed by a jet mill crusher to a particle size of 5 - 20  microns to produce a toner. 
     One part by weight of the resulting fine powder toner was mixed with 3 - 30 parts by weight, preferred with 5 - 10 parts by weight of iron powder carrier. 
     An electrostatic latent image on an insulating layer produced by an electrophotographic method of Japanene Pat. Publication No. 23910/1967 was developed with a developer by a magnetic brush method to form a toner image. 
     Japanese acid clay 50 parts by weight, glycol palmitate 25 parts by weight, styrene-butadiene latex 20 parts by weight, water 150 parts by weight and an emulsifier (trade name, Dresinate, supplied by Hercules Co.) 0.4 parts by weight were mixed and ground for 24 hours by a ball mill. The resulting emulsion liquid was coated on a paper at an amount of 10 g./m. 2  (as solid) to produce a transferring paper. The toner image as obtained above was transferred to this transferring paper and heated at 200° c. to produce a bluish black color image at a portion to which the toner image was transferred. This colored image was not vanished at all even when rubbed with an eraser. 
     EXAMPLE 81 
     
         ______________________________________                                    
Crystal Violet Lactone                                                    
                   20 parts by weight                                     
Polystyrene (trade name,                                                  
                   80 parts by weight                                     
 Piccolastic D-70)                                                        
Stearic acid       10 parts by weight                                     
Silica powder (trade name,                                                
                   10 parts by weight                                     
 Erogyl 200, supplied by                                                  
 Nihon Erogyl)                                                            
______________________________________                                    
 
    
     The above mentioned components were mixed, melted, cooled and ground to a particle size of less than 5 microns by a jet mill crusher to produce a toner. 
     100 G. of the resulting fine powder toner was added to 1 l of Isopar H and crushed to a particle size of 1 - 2 microns by an attritor. 50 Ml. of this concentrated liquid was dispersed in 2 l of Isopar H to form a liquid developer. 
     An electrostatic latent image on an insulating layer obtained by an electrophotographic method of Japanese Pat. Publication No. 23910/1967 was developed with the liquid developer as produced above to form a toner image. 
     Phenol aldehyde polymer 50 parts by weight, phenyl palmitate 25 parts by weight, styrene-butadiene latex (film forming agent) 20 parts by weight, water 150 parts by weight, and an emulsifier (trade name, Dresinate X) 0.4 part by weight were mixed and ground for 24 hours by a ball mill. The resulting suspension liquid was coated on a paper at an amount of 10 g./m. 2  (as solid) to form a transferring paper, to which the toner image as obtained above was transferred followed by heating at about 180° C. to form a sharp blue color image at a portion to which the toner image was transferred. The resulting colored image was not vanished at all when rubbed with an eraser. 
     EXAMPLE 82 
     Styrene resin (trade name, Piccolastic D-125, supplied by Esso Standard Petroleum) 70 parts, stearic acid glycerine ester (m.p. 72° C.) 15 parts and Crystal Violet Lactone (CVL) 20 parts were mixed and ground by a vibrating mill grinder. The resulting mixture was sufficiently melted, and cooled to solidify. The resulting solid matter was crushed by a hammer mill crusher and then pulverized by a jet mill grinder to a particle size of 1 - 50 microns, preferred with 5 - 20 microns. 
     One part by weight of the resulting fine powder, i.e. toner, was mixed with 3 - 30 parts by weight, preferred with 5 - 10 parts by weight, of iron powder, i.e. carrier. Particle size of the carrier is 20 - 75 microns, preferred with 25 - 50 microns. 
     Then, an electrostatic latent image on an insulating layer obtained by an electrophotographic method of Japanese Pat. Publication No. 23910/1967 was developed with a developer as obtained above by a magnetic brush method to produce a toner image. The resulting toner image was transferred to a transferring paper obtained by coating a high grade paper (50 - 60 g./m. 2 ) with a mixture of styrene-butadiene copolymer latex as binder 20% by weight, Dresinate X (trade name, supplied by Hercules Co.) as emulsifier 0.3% by weight, and phenol-aldehyde polymer (finely divided particle of 1 - 3 microns in size) as color forming agent B 79.7% by weight, dispersed in water at an amount of 10 g.m. 2  (as solid), and heated at 180° C. to produce a completely fixed sharp blue image. The resulting colored image was not vanished at all by rubbing with an eraser. 
     EXAMPLES 83 - 121 
     Seventy parts of a binder resin, 15 parts of a color forming auxiliary agent and 20 parts of a color forming agent as shown in Table 19 were mixed and ground by a vibrating mill grinder. 
     The resulting mixture was sufficiently melted and cooled to solidify. The resulting solid matter was crushed by a hammer mill crusher and then finely divided by a jet mill grinder to a particle size of 1 - 50 microns, preferred with 5 - 20 microns. The resulting finely divided powder, i.e. toner, was mixed with 3 - 30 parts by weight, preferred with 5 - 10 parts by weight, or iron powder, i.e. carrier which particle size was 20 - 75 microns, preferred with 25 - 50 microns. 
     Then, an electrostatic latent image on an insulating layer produced by an electrophotographic method of Japanese Pat. Publication No. 23910/1967 was developed with the toner obtained above by a magnetic brush method to form a toner image. The resulting toner was transferred to a transferring paper produced by coating a high grade paper (50 - 60 g./m. 2 ) with styrene-butadiene copolymer latex as binder 20% by weight, Dresinate X (trade name, supplied by Hercules Co.) as emulsifier 0.3% by weight, a color forming agent (B) selected from Table 20 (finely divided matter) 79.7% by weight dispersed in water at an amount of 10 g./m. 2  (as solid), and then heated at about 170°- 180° C. to produce a completely fixed sharp image. The resulting image was not vanished at all when rubbed strongly with an eraser. 
     
                                           Table 19                                
__________________________________________________________________________
                Color forming                                             
Example Binder  auxiliary                                                 
                         Color forming                                    
                                     Transferring                         
No.     resin   agent    agent       paper                                
__________________________________________________________________________
83   Epoxy resin                                                          
                Stearic acid                                              
                         Malachite Green                                  
                                     1                                    
84   Vinsol resin                                                         
                &#34;        &#34;           1                                    
85   Polyvinyl chloride                                                   
                &#34;        &#34;           1                                    
     resin                                                                
86   Polypropylene resin                                                  
                &#34;        &#34;           1                                    
87   Polyethylene resin                                                   
                &#34;        &#34;           1                                    
88   Styrene-metayl                                                       
                &#34;        &#34;           1                                    
     acrylate copolymer                                                   
89   Vinyl chloride-                                                      
                &#34;        &#34;           1                                    
     vinyl acetate                                                        
     copolymer                                                            
90   Epoxy resin                                                          
                Myristic acid                                             
                         Crystal Violet                                   
                                     2                                    
                         lactone                                          
91   &#34;          &#34;        Malachite Green                                  
                                     2                                    
                         lactam                                           
92   &#34;          &#34;        8&#39;-Methoxyincolino-                              
                                     2                                    
                         spiropyrane                                      
93   &#34;          &#34;        Rhodamine   2                                    
                         lactam                                           
94   &#34;          &#34;        6,6&#39;-diaminospiro                                
                                     2                                    
                         (phthalan 1,9&#39;-                                  
                         xasthene)                                        
95   &#34;          &#34;        1,1-bis(g-amino-                                 
                                     2                                    
                         phenyl) phthalan                                 
96   &#34;          &#34;        N-(2,5-dichlorophenyl)                           
                                     2                                    
                         leuco auramine                                   
97   &#34;          &#34;        N-acetylauramine                                 
                                     2                                    
98   &#34;          &#34;        Dianisylidene                                    
                                     2                                    
                         acetone                                          
99   Polyvinyl  Behenic acid                                              
                         Crystal Violet                                   
                                     3                                    
     chloride resin      lactone                                          
100  &#34;          Lacceric acid                                             
                         &#34;           3                                    
101  &#34;          Methyl behenate                                           
                         &#34;           3                                    
102  Polyvinyl  Methyl   Crystal Violet                                   
                                     3                                    
     chloride   melissinate                                               
                         lactone                                          
     resin                                                                
103  &#34;          Ethyl    &#34;           3                                    
                lignocerate                                               
104  &#34;          Phenyl   &#34;           3                                    
                palmitate                                                 
105  &#34;          Glycol   &#34;           3                                    
                myristate                                                 
106  &#34;          Glycol   &#34;           3                                    
                stearate                                                  
107  Vinyl      Glycerol &#34;           3                                    
     chloride   laurate                                                   
     resin                                                                
108  &#34;          Glycerol &#34;           3                                    
                stearate                                                  
109  &#34;          &#34;        Malachite Green                                  
                                     4                                    
                         lactone                                          
110  &#34;          Propionic acid                                            
                         &#34;           4                                    
                amide                                                     
111  &#34;          Palmitic acid                                             
                         &#34;           4                                    
                amide                                                     
112  &#34;          Caprylic acid                                             
                         &#34;           4                                    
                anilide                                                   
113  &#34;          Behenic acid                                              
                         &#34;           4                                    
                amide                                                     
114  &#34;          Myristic acid                                             
                         &#34;           4                                    
                methylamide                                               
115  &#34;          Stearic acid                                              
                         &#34;           4                                    
                dodecylamide                                              
116  Styrene    Glycerol Crystal violet                                   
                                     5                                    
     resin      stearate lactone                                          
117  &#34;          &#34;        &#34;           6                                    
118  &#34;          &#34;        &#34;           7                                    
119  &#34;          &#34;        &#34;           8                                    
120  &#34;          &#34;        &#34;           9                                    
121  &#34;          &#34;        &#34;           10                                   
__________________________________________________________________________
 
    
     
                       Table 20                                                    
______________________________________                                    
Transferring                                                              
Iember No. Color forming agent                                            
______________________________________                                    
1          Thenol-aldehyde polymer                                        
2          Phenol-acctylene polymer                                       
3          Rosin modified maleic resin                                    
4          Hydrolyzed product of styrene-maleic                           
           anhydride copolymer                                            
5          Hydrolyzed product of ethylene-maleic                          
           anhydride copolymer                                            
6          Hydrolyzed product of carboxy                                  
           polyethylene polymer                                           
7          Vinyl methyl ether-maleic anhydride                            
           copolymer                                                      
8          Japanese acid clay                                             
9          Bentonite                                                      
10         Phenol-aldehyde copolymer + Japanese                           
           acid clay (1 : 1)                                              
______________________________________                                    
 
    
     EXAMPLE 122 
     Styrene resin (trade name, Piccolastic D-125, supplied by ESSO Standard Oil, softening point 90°-125° C.) 70 parts, Glycol stearate (mp. 75° C.) 30 parts, and Crystal Violet Lactone (CVL) 20 parts were mixed and crushed by a vibrating mill crusher. The resulting mixture was then sufficiently melted and cooled to solidify. 
     The resulting solid matter was crushed by a hammer mill crusher and then by a jet mill grinder to form a toner of a particle size of less than 5 microns, and 100 g. of the resulting toner was sufficiently ground together with 1 l. of Isopar H by an attritor to form a concentrated liquid developer containing a toner of 1-2 microns in particle size. 50 Ml. of the resulting concentrated liquid was dispersed in 2 l. of Isopar H to form a liquid developer. 
     A quarternary ammonium salt polymer (trade name, CP-261, supplied by Calgon Corp.) was applied onto a polyethylene terephthalate film (100 microns thick) having a gelatine undercoating to impart electroconductivity and then dried sufficiently. Further, a 5% solution of cyanated polyvinylcarbozole sensitized by Crystal Violet was coated on the film obtained as above by using a roll to form a photoconductive film. 
     On the resulting photoconductive film was coated a 6% solution of cyanated polyvinylcarbazole 10 parts and a hydrolyzed product of ethylene-maleic anhydride copolymer 8 parts in monochlorobenzene in the thickness of 4-6 g./m.2 by a roll. 
     The resulting photoconductive film was subjected to a uniform corona charging, exposed to a light pattern to for an electrostatic latent image, developed with the toner as obtained above, and heated to form a completely fixed blue color image. 
     EXAMPLE 123 
     70 Parts of vinyl chloride - vinyl acetate (91 : 9 mole %) copolymer resin, 10 parts of glycol stearate and 20 parts of Crystal Violet Lactone (CVL) were mixed and crushed by a vibrating mill grinder. The resulting mixture was sufficiently mixed, melted and cooled to solidify. 
     The resulting solid matter was crushed by a hammer mill and then by a jet mill grinder to a particle size of 1-50 microns, preferred with 5-20 microns. One part of the resulting finely divided toner was mixed with 3-30 parts by weight, preferred with 5-10 parts by weight, of iron powder, i.e. carrier. Particle size of the carrier was 20-75 microns, preferred 25-50 microns. 
     A photoconductive layer of ZnO - binder system was uniformly corona-charged, exposed to a light pattern and developed to form a toner image. The resulting toner was transferred to a transferring paper produced by coating a high grade paper (50-60 g.m. 2 ) with styrene-butadiene copolymer latex as binder 20% by weight, Dresinate X (trade name, supplied by Hercules Co.) as emulsifier 0.3% by weight, a hydrolyzed product of vinyl methyl ether - maleic anhydride (finely divided) as color forming agent (B) 79.7% by weight dispersed in water at an amount of 10 g./m2 (as solid), and then heated at about 180° C. to produce a completely fixed sharp blue image. The resulting image was not vanished at all when rubbed strongly with an eraser. 
     EXAMPLE 124 
     OPBA (Formula 1) 50 parts, stearic acid 30 parts, styrene - butadiene latex 20 parts, water 150 parts, and Dresinate X (trade name, supplied by Hercules Co., an emulsifier) 0.4 parts were mixed and ground for about 10 hours by a bail mill grinder. The resulting emulsion liquid was coated on a paper at an amount of 10 g./m 2  (as solid), dried by heating and cut to an appropriate size. The resulting paper was used as an image receiving sheet. 
     8&#39;-Methoxyindolinospiropyrane 40 parts and styrene resin (trade name, Piccolastic D-125, supplied by ESSO Standard Oil) 60 parts, were mixed, melted, cooled to solidify and finally divided. The particle size distribution was 1-30 microns, preferred with 5-15 microns. One part of the resulting toner was mixed with 3-30 parts by weight, preferred with 5-10 parts by weight, of iron powder, i.e. carrier. The particle size of carrier was 20-75 microns, preferred with 25-50 microns. 
     In developer comprising the carrier and the toner, the carrier was positively charged and the toner was negatively charged. 
     The resulting developer was placed in a developing device of magnetic brush type. According to an electrophotographic process of Japanese Pat. Publication No. 23910/1967, a toner image was formed by using an electrophotographic copying machine (trade name, NP-1100, manufactured by Canon K.K.) and transferred to the above mentioned image receiving sheet followed by color forming and fixing by a fixing apparatus. Thus, a clear bluish black copy was obtained at 160° C. The resulting image was not vanished at all even when rubbed with an eraser. 
     EXAMPLE 125 
     An image receiving sheet used here was prepared following the procedure of Example 124. 
     The same amounts of film forming agent, emulsifier, and water so in Example 24, the compound of Formula (2) i.e. color forming agent (B), 50 parts and myristic acid (color forming auxiliary agent) 25 parts were mixed, ground and coated on a paper to form an image receiving sheet. 
     A toner was prepared following the procedure as in Example 124 by using 40 parts of Crystal Violet Lactone (CVL) and 60 parts of p-cyanostyrene-styrene copolymer (cyanostyrene 43% and styrene 95.7%) (supplied by Denki Kagaku Kogyo), and further a developer was prepared in a way similar to Example 124. In the developer, the carrier was positively charged and the toner negatively charged. The developer was placed in a developing device of magnetic brushing type and a toner image was produced on a drum surface having a photosensitive layer according to NP system of Canon K.K. and the resulting toner image was transferred to the image receiving sheet and subjected to a color forming and fixing treatment to form a sharp blue copy at about 160° C. 
     EXAMPLE 126 
     The same amounts of film forming agent, emulsifier and water as those in Example 124, 50 parts of the polymer of Formula (3) (color forming agent B), and 25 parts of glycerol stearate (color forming auxiliary agent) were mixed, ground and coated on a paper in a way similar to Example 124 to produce an image receiving sheet. 
     Toner was produced by using 40 parts of rhodamine lactone (RL) and 60 parts of polyester resin (trade name, XPL 2005, supplied by Kao Atras) in a way similar to Example 124 and then a developer was produced. In the developer, the carrier was negatively charged and the toner positively charged. 
     Then the developer as obtained above was placed in a developing denice of magnetic brush type. A drum surface having a photoconductive ZnO was negatively charged, exposed to an original pattern to form an electrostatic latent image, and developed by using the above mentioned developer to form a toner image. The toner image was transferred to the image receiving spect and subjected to a color forming and fixing treatment at about 170° C. to produce a sharp red copy. 
     EXAMPLE 127 
     An image receiving sheet was prepared in a way similar to Example 124 by mixing the same amount of film forming agent, emulsifier, and water as those in Example 124, a polymer of Formula (4) (color forming agent B) 50 parts, and lauric dodecyamide (color forming auxiliary agent) 25 parts, grinding the mixture and coating on a paper. 
     As toner, leuco auramine (LA) was finely divided and a developer was prepared in a way similar to Example 124. In the developer, the carrier was negatively charged and the toner was positively charged. Then, the above mentioned developer was placed in a developer of magnetic brush type. A drum surface having photoconductive ZnO was negatively charged and exposed to an original light pattern, and the resulting electrostatic latent image was developed by the above-mentioned developing device to form a toner image, which was then transferred to the above-mentioned image receiving sheet and subjected to a color forming and fixing treatment at about 170° C. to form a sharp yellow copy. 
     EXAMPLE 128 
     The same amounts of film forming agent, emulsifier, and water as those in Example 124, a compound of Formula (1) (color forming agent B) 50 parts and methyl montanate (color forming auxiliary agent) 25 parts were mixed, ground, coated on a paper in a way similar to Example 124 to produce an image receiving sheet. 
     As a toner, there were used 40 parts of CVL and 60 parts of polyvinyl chloride resin (trade name, Denka Vinyl, supplied by Denki Kagaku Kogyo K.K.) in a way similar to Example 124 to produce a developing agent. In the developer, the carrier was positively charged and the toner was negatively charged. 
     The electrostatic latent image on the surface of the photosensitive was developed by the developing device according to Canon NP System to form a toner image. The resulting toner image was transferred to the image receiving sheet and subject to a color forming and fixing treatment, and the resulting clear blue copy was obtained at about 170° C. 
     EXAMPLE 129 
     A base paper was coated with a 2% aqueous solution of sodium alginate at an amount of 3 g./m 2 . and then coated with a solution of phenol formaldehyde polymer (5 parts) and polyvinyl butyral (5 parts) in methyl ethyl ketone (100 parts) at an amount of 7g./m2. to produce an electrostatic paper, to which a high voltage pattern of +500 volt was applied by a needle electrode to form a charge pattern. This charge pattern was developed with a liquid developer as used in Example 15 and heated to form blue color at the toner image portion resulting in a completely fixed clear copy. 
     EXAMPLE 130 
     Crystal Violet Lactone as color forming agent A was placed in a pulverzier to pulverize to a particle size of 1-50 microns, preferred with 5-20 microns, and then particles incapable of passing a 200 mesh sieve were removed. 
     The particles thus sieved were mixed with iron powder as carrier. The amount of iron powder was 8-50 parts by weight, preferred with 10-20 parts by weight, per one part by weight of toner. Particle size of iron powder was 20-75 microns, preferred with 25-40 microns. A mixture of iron powder and toner was charged in a developing device of magnetic brush type. A printing paper used here was a paper on which a phenolic resin (trade name, Tamanol, supplied by Arakawa Rinsan) was coated together with an appropriate binder. 
     Whole surface of a photoconductive member of zinc oxide - binder resin was negatively charged, exposed to a light and dark pattern and then passed through a developing device. The toner particle attached to a negatively charged toner. The toner image on the zinc oxide paper as master sheet was thermally transferred to the printing paper coated with phenolic resin by thermal pressing according to a process as shown in FIG. 6, and a blue image was produced on the printing paper. By repeating the above procedure, 15 sheets of good copy were obtained and each of these sheets was not different from the first copy in point of image quality. 
     EXAMPLE 131 
     The same developer and image receiving sheet as those in Example 130 were used. On a rotating drum having a selenium photoconductive photosensitive layer, there was formed a toner image by a process comprising charging exposing and development. A printing paper coated with phenolic resin as previously heated to soften the phenolic resin layer. When the printing paper was contacted with the toner image to give a good image. From the same master sheet there were obtained 13 sheets of copy of good quality. 
     EXAMPLE 132 
     Leuco rhodamine (RL) as toner was pulverized to a particle size of 1-10 microns, and dispersed in Isopar H (trade name, supplied by ESSO Standard Oil) to produce a developer. According to the procedure in Example 130 and conventional method, a ZnO paper was negatively charged, exposed to form an electrostatic latent image in a form of mirror image with respect to the original pattern, and developed in a liquid developer. The resulting toner image on the ZnO paper was dried. Then there was obtained a colored image on a printing paper in a way similar to the method of Example 130. The color image was red image of good quality. From the toner image there were obtained 20 sheets of good copy. 
     EXAMPLE 133 
     80 parts of CVL and 20 parts of myristic acid were mixed and melted, and further procedure was effected in a way similar to Example 130. The color forming temperature was 60° C. The color tone was not different from that of Example 130 at all. From one master sheet there were obtained 10 sheets of copy. 
     EXAMPLE 134 
     Leuco auramine as toner was used for preparing a developer according to a procedure as in Example 130. 4-Tertiary amylphenol 50 parts, styrene-butadiene latex 15 parts, polyvinylpyrrolidone 0.5 parts and water 34.5 parts were mixed and coated on a paper to produce a printing paper. In a way similar to Example 130, there were obtained 15 sheets of good copy. 
     EXAMPLE 135 
     A photosensitive member composed of polyester film (as insulating film) overlying on a photoconductive selenium was charged according to a Known method and selectively discharged to form a latent image. Then, a mixture of CVL 80 parts and polyamide resin 20 parts was melted and ground to a particle size of 1-20 microns. A master sheet was produced by a magnetic brush development and the image was transferred to a printing paper coated with phenolic resin in a way similar to Example 130. From this master sheet there were obtained 20 sheets of good copy. 
     EXAMPLE 136 
     Three sheets of photoconductive ZnO paper were negatively charged. By using an exposing device, the first ZnO paper was exposed through a red filter, the second ZnO paper through a green filter and the third ZnO paper through a blue filter to form each latent image. The first ZnO paper was developed by the same procedure as in Example 130  to form a toner image. The second ZnO paper was developed by rhodamine lactone to form a toner image. The third ZnO paper was developed by RA to form a toner image. 
     Bisphenol A 50 parts and diacetone acrylamide 50 parts were melted and mixed, and ground together with styrene-butadiene latex (trade name, DOW 636, supplied by Dow Chemical Co.) as binder, and then applied to a paper in the thickness of several microns to produce a printing paper. By using the apparatus as illustrated in FIG. 6, the above mentioned three ZnO paper having each toner image were subsequently pressed to the printing paper and heated to form color. Thus, multiple printing were effected on the printing paper to produce a colored image. The resulting image was almost similar to color image of the original. About 8 sheets of the multiprinting image were obtained.