Stencil-print colour
United States Patent 91 Piiroya et al.  
 [451 Apr. 29, 1975 1 STENCIL-PRINT COLOUR [76] Inventors: Eduard Karlovich Piiroya, Bulvar Karla Marxa, 15, kv. 9, Tallinn, U.S.S.R.; Mati Endel-Agustovich Pyldsaar, ul. Sovetskaya 7, kv. 78, lvanovo, U.S.S.R.; Anti Kheldurovich Viikna, ul. Tatari l5, kv. 8, Tallinn. U.S.S.R.  
 [22] Filed: Dec. 27, 1973 [21] Appl. No.: 428,862  
 Related US. Application Data [63] Continuation-in-part of Scr. No. 378,902, July 13, 1973, abandoned. which is a continuation of Ser. No. 212,670, Dec. 27, 1971, abandoned.  
 [52] US. Cl. 260/22 S; 106/28; 106/32; 117/38; 117/161 K; 260/19; 260/20; 260/32.85 B; 260/33.65 B; 260/33.25 B;  
 Primary E.ramincr-Ronald W. Griffin Attorney, Agent, or FirmHolman &amp; Stern [57] ABSTRACT A stencil-print colour comprising a linseed varnish which is essentially polymerized linseed oil, or pentaphthalic varnish which is polypentaerythiitplphthalate modified by linseed, tung, or castor;  
  and dissolved in said oil; or glyptal varnish which is polyglycerol-phthalate modifed by linseed, tung, or castor oil and dissolved in said oil; or a mixture of said varnishes; a resin selected from phenol-formaldehyde resins or from those modified by colophony; metal salts of higher carboxylic acids having more than six carbon atoms; pigments, an organic solvent and a mixture of polymethylspirocyclosiloxanes of the following formula:  
 O-Si-O n wherein n=2 to 7 with an average molecular weight ranging from 800 to 1,500; the components of the colour being taken in the proportions as follows (parts by weight):  
 varnishes 100 resin 75-125 metal salts of higher carhoxylic acids 225 pigments 51 21) organic solvent 75-175 mixture of polymethylspirocyclosiloxanes l-20.  
 The stencil-print colour of the present invention features a good homogeneity and elasticity. It does not fill the screen stencil when used for printing at both high and low speeds. With the use of this colour high-quality prints and painted articles are obtained.  
 14 Claims, No Drawings 1 2 STENCIL-PRINT COLOUR phenol-formaldehyde resins or from those modified by colophony; metal salts (3) of higher carboxylic acids This application is a continuation-in-part of cohaving more than Six Carbon atoms; Pigments and pending application Ser. No. 378,902, filed July 13, an Organic Solvent and Z1 Iu polymethyl- 1973, now abandoned, which in turn was a Rule 60 vspirotiyclosiloxanes 0f h ing f rm l CH O Si. 0 H s i O Si. O :1  
 continuation of Ser. No. 212,670, filed Dec. 27, I971. ,where n 2 to 7, with an average molecular weight now abandoned. ranging from 800 to 1,500; the colour components The present invention relates to stencil-print colours being taken in the following proportions (parts by used in printing on polymer materials, glass, metal, reweight): generated cellulose (cellophane) and the like, as well as for painting the surface of said materials. (l) 1 i i Known in the art heretofore are stencil-print colours a Quits 3 of higher mcorporatrng linseed-oil varnish which is polymerized flglrbflXylic dCiGIS 5 linseed oil, or pe ntaphthalic varnish which is essentially g &#39;l f &#39;l zg ii (5) ;l polypentaerythritol-phthalate modified by a vegetable mixture of polymethylspirocyclosiloxanes (6) 1-20 oil (such as linseed oil, tung or castor oil) and dissolved in said oil; or glyptal varnish which is essentially poly- According to the present invention, the mixture of glycerol-phathalate modified by a vegetable oil (linpolymethylspirocyclosiloxanes is added to the colour to seed, tung or castor oil) and dissolved in said oil; or a preclude the formation of supramolecular structures, mixture of said varnishes; a resin selected from phenolimprove homogeneity and elasticity of the colour, in-  
 formaldehyde resins or those modified by colophony; 3O crease its brightness, as well as to enhance wettability metal salts of higher carboxylic acids having more than of printing materials, e.g. polyethylene, by the colour,  
 six carbon atoms; pigments and an organic solvent. The introduction of said polysiloxane additive makes it Also known in the art are stencil-print colours compossible to make a full use of the colour components in prising a solution of various resins, preferably lowtheir optimal proportions ensuring the effect of rapid molecular polyamides, in highly volatile organic soldrying of the colour. With the use of such a stencilvents, and pigments. print colour, the filling of the screen stencil therewith The prior-art colours of the former type have a proin printing on high-speed machines with an output of longed drying time (20 to 30 minutes at 60C), whereabout 5.0006,000 prints per hour is completely fore they are not suitable for use in printing machines. avoided. Moreover, said colours are liable to formation of supra- The stencil-print colour of the present invention may molecular structures upon drying, wherefore offincorporate, as the above resins, such high-molecular quality prints having a brittle film colour layer are obcompounds as, for example, diphenylolpropanetained. formaldehyde resin, modified by colophony, phenol- The prior-art colours of the latter type are liable to formaldehyde resin, and cresol-formaldehyde resin. fill the screen stencil when used in printing presses with As the metal salts of higher carboxylic acids, the stenan output of below 4,000 prints per hour. When used cil-print colour of the present invention may contain, in high-speed printing machines with an output exceedfor example, resinates, linoleates, naphthenates of caling 4,000 prints per hour. said colours result in offcium, manganese, lead, cobalt, aluminium (both as an quality prints with a brittle film colour layer. individual salt and various mixtures of individual salts).  
  It is an object of the present invention to provide a As the pigments, the stencil-print colour of the presstencil-print colour possessing good homogeneity and ent invention may incorporate organic or inorganic pigelasticity. ments and mixture thereof.  
 It is another object of the present invention to pro- As the organic solvents, the stencil-print colour of vide such a stencil-print colour which would not fill the the present invention may comprise such solvents as screen stencil when used at both high and low printing toluene, ethylacetate, butylacetate, cyclohexanone,  
 speeds. ethylene-glycol monoethylate (Ethylcellosolve) ethy- In accordance with these and other objects, the preslene-glycol mono-n. ,butylate (Butylcellosolve) or mixent invention resides in the provision of a stencil-print tures thereof.  
 colour comprising a varnish l selected from the To preclude filling of the screen stencil by the colour group consisting of linseed-oil varnish which is essenduring printing on high-speed printing machines (with tially polymerized linseed oil. pentaphthalic varnish an output ranging from 3,000 to 5,000 prints per hour), which is polypentaerythritolphthalate modified by a it is advisable to use. in accordance with the present invegetable oil (linseed oil, tung or castor oil) and disvention, a colour incorporating also tetrahydrosolved in said oil, glyptal varnish which is essentially naphthalene, decahydronaphthalene, methylcyclohexpolyglycerol-phthalate modified by a vegetable oil (linanol or mixtures thereof in an amount ranging from 1 seed oil, tung or castor oil) and dissolved in said oil, or to 10 parts by weight per l00 parts by weight of the vara mixture of said varnishes; a resin (2) selected from nishes used.  
  The introduction of said compounds into the stencilprint colour of the present invention precludes its premature drying on the screen stencil during the printing process. while not affecting the colour drying rate at the stage of prints drying (at a temperature of about 60C).  
  To prevent the screen stencil from filling with the colour during printing on machines with an output within the range of from 500 to 3,000 prints per hour or on manually-operated printing presses with an output of 15 to 30 prints per hour, it is advisable, in accordance with the present invention, to use a stencil-print colour which is incorporated with pentaphthalic varnish comprising polypentaerythritol-phthalate modified by linseed-oil and dissolved in said oil in an amount ranging from 5 to 50 parts by weight per 100 parts by weight of the varnishes contained in the colour.  
  The introduction of the above-mentioned varnish into the stencil-print colour of the present invention precludes its premature drying on the screen stencil during printing on machines and presses with a small output.  
  To ensure a better sharpness of an imprint on a substrate, the colour may be incorporayed with a filler, viz. aluminium hydroxide or its mixture with barium sulphate in an amount of from l to 50 parts by weight per 100 parts by weight of the varnishes employed.  
  The stencil-print colour of the present invention features a high adherence to the surface of metal, glass, polymer materials and the like. The surface of polyethylene and polypropylene materials, prior to printing or painting, must be activated by treating thereof with gas flame, chemicals or by using corona discharge.  
  When dried, the colour film is elastic, wear-resistant; it has a good brightness and chemical resistance (including resistance against surface-active agents); it is not liable to ageing when exposed to UV-radiation.  
  The stencil-print colour according to the present invention is prepared in the following manner.  
  There is prepared a 50% solution of a resin selected from phenol-formaldehyde resins or from those modified by colophony in one of the above-mentioned organic solvents or in one of the mixtures thereof. Thereafter, the resin solution is added with the remaining components of the above-specified formulation (except the metal salts of higher carboxylic acids and the mixture of polymethylspirocyclosiloxanes); the mixture is charged into an attrition mill, a bead mill or a vibrating mill to be particulated therein to a fineness of 5 to mcm (Composition 1).  
  The metal salts of higher carboxylic acids and the mixture of polymethylspirocyclosiloxanes of the aforegiven generic formula are also mixed up in the proportions specified in the above-mentioned formulation to give Composition 2.  
  Prior to use (printing or painting of articles), the compositions thus prepared are blended and thoroughly intermixed to yield a stencil-print colour. Before being intermixed, said compositions 1 and 2) may be stored for a long period (above one year) with their properties remaining unchanged.  
  When appropriat, the final stencil-print colour may be added with a solvent to bring the colour to a desirable working consistency. In addition, when drying time is to be increased, the ready colour is incorporated, as has been mentioned hereinbefore, with pentaphthalic varnish which is essentially polypentaerythritol-phthalate modified by linseed oil and dissolved in said oil.  
  In case of using colour mills, the colour preparation technique somewhat differs from the above-described. In this case, the pigment and filler (if prescribed in the colour formulation) along with the varnishes are particulated in a colour mill to a required degree of fineness (5 to 10 mcm) to give a pigment paste. At the same time. a 50-60% solution of the resin in one of the aforesaid organic solvents or in a mixture thereof is prepared. Then, to prepare Composition 1, said pigment paste is mixed with the resin solution and with such components as tetrahydronaphthalene, decahydronaphthalene methylcyclohexanol or their mixtures, if prescribed in the colour formulation.  
  The metal salts of higher carboxylic acids and the mixture of polymethylspirocyclosiloxanes of the abovementioned generic formula are intermixed to give Composition 2.  
  Prior to use, the thus prepared compositions are blended and thoroughly intermixed to give the final stencil-print colour.  
  For a better understanding of the present invention the following specific examples of the stencil-print colour are given hereinbelow by way of illustration.  
 EXAMPLE 1 29 kg of pentaphthalic varnish (polypentaerythritolphthalate modified by linseed oil and dissolved therein) and 60 kg of a 50% solution of diphenylolpropaneformaldehyde resin modified by colophony are mixed in a mixture of solvents consisting of 13 kg of cyclohexanone, 8.5 kg of toluene, and 8.5 kg of ethylacetate with 17 kg of red organic pigment, 0.5 kg of tetrahydronaphthalene, and 3.5 kg of a mixture of aluminium hydroxide and barium sulphate (in a weight ratio between aluminium hydroxide and barium sulphate of 1:2). The resulting mixture is charged into an attrition mill and desintegrated therein to a fineness of 5 and 10 mcm (Composition 1).  
  Said pentaphthalic varnish has been preliminary prepared in the following manner. To 750 kg oflinseed oil were added 142 kg of pentaerythritol and 35 kg of lead oxide and the resulting mixture was heated at a temperature of 250260C for 6 hours. Then the mixture was added with 245 kg of phthalic acid anhydride, 0.5 kg of triphenyl phosphite, 50 kg of xylene and the reaction mixture was heated at a temperature of 225-230C for 8 hours, whereafter the xylene was distilled off in vacuum.  
  Said diphenylolpropane-formaldehyde resin modified by colopheny has been preliminary produced in the following manner. 240 kg of diphenylolpropane, 50 kg of paraform, 200 kg ofa 36% formaldehyde solution and 1.5 kg of calcium hydroxide were charged into a reactor; the reaction mixture was heated to 40C, whereafter the heating was discontinued and the reaction mixture was maintained at a temperature of from 40 to 50C for 4 hours. Then 1,500 kg of molten colophony preliminary exempted from terpenes by steamdistillation were charged into the reactor; the mixture temperature was elevated to l180C and the mixture was maintained at this temperature for 4 hours. Then kg of glycerol were added, the mixture temperature was elevated to 240C and the reaction mixture was allowed to stay at this temperature for 22.5 hours. The thus prepared high-molecular compound (resin) has the following structural formula:  
  Along with Composition I mentioned hereinabove. Composition 2 was prepared by way of mixing, in a separate vessel, 1.5 kg of cobalt naphthenate, 1.5 kg of a mixture of calcium, manganese. and lead linoleates (in the weight ratio of 1:1:1 and 3 kg of a mixture of polymethylspirocyclosiloxanes.  
  Said mixture of polymethylspirocyclosiloxanes has been preliminary prepared in the following manner. 140 kg of water, 30 kg of n-butanol, and 18 kg of toluene or xylene were charged into a reactor. Then, a solution of 28.4 kg of dimethyldichlorosilane and 12.4 kg of silicon tetrachloride in 18 kg of toluene or xylene was slowly added to the reaction mixture under vigourous stirring. The resulting mixture was stirred in the reactor for additional 1-2 hours, whereafter the reactor contents was allowed to stratify into two layers. The lower aqueous layer was discharged, while the upper layer comprising a solution of the desired product in organic solvents was washed with water until a neutral reaction was obtained, whereafter the solvents (nbutanol and toluene or xylene) were distilled off in vacuum. The desired product (bottom residue) was not resolved into individual compounds but used as it was, i.e. in the form of the final product comprising a mixture of polymethylspirocyclosiloxanes of the formula:  
  Using this colour, printing may be effected only on highspeed machines with an output of 5,000-6,000 prints per hour.  
  For printing on machines with an output of from 500 to 3.000 prints per hour as well as on manuallyoperated printing presses with an output of 15 to 30 prints per hour without filling of the screen stencil, into the prepared colour (both containing tetrahydronaphthalene and without it) pentaphthalic varnish was added comprising polypentaerythritol-phthalate modifled by linseed oil and dissolved therein.  
  The effect of said pentaphthalic varnish added to the stencil print colour on the complete drying time thereof is evident from the following Table.  
 Table Amount of pentaphthalie varnish as percentage of Complete drying time of colour, minutes where n=2 to 7. with an average molecular weight ranging from 800 to 1,500.  
 . 5 Prior to printing. both composition 1 and Composition 11 were intermixed to give a stencil-print colour which had complete drying time as follows:  
  to 60 minutes 2 to 4 minutes I to 2 minutes.  
 at 18-20C 10 to 15 minutes at 60C 2 to 4 minutes at 90C 1 to 2 minutes.  
 With the use of the thus-prepared colour there were 0 obtained high-quality prints and painted articles. The  
 colour did not form supramoleeular structures during the drying process. The dried colour film is elastic; it is not liable to ageing upon prolonged storage in the air or upon exposure to UV-radiation.  
 EXAMPLE 2 24 kg of pentaphthalic varnish prepared in a manner similar to that described in Example 1, 1.7 kg of linseed-oil varnish (polymerized linseed oil of a low polymerization degree) 60 kg ofa 50% solution of diphenylolpropane-formaldehyde resin modified by colophony and prepared as in Example 1 were intermixed in a mixture of solvents consisting of 10 kg of cyclohexanone and 20 kg of toluene with 4 kg of an inorganic blue pigment. 1.5 kg of carbon black, 0.8 kg of an organic black pigment. 6 kg of aluminium hydroxide. and 4 kg of barium sulphate. The mixture was charged into a bead mill and desintegrated therein to a fineness of a ready-to-use stencil-print colour.  
  The properties of the colour thus prepared were similar to those of the colour as prepared in Example 1.  
 EXAMPLE 3 24 kg of glyptal varnish (polyglycerol-phthalate modified by tung oil and dissolved therein) and 25 kg of titanium dioxide were mixed and then desintegrated in a colour mill to a fineness of to mcm. Then. the pigment paste thus prepared was mixed with 50 kg of a solution of diphenylolpropane-formaldehyde resin (25 kg of the resin and 25 kg of ethylene-glycol monoethylate) and 0.3 kg of methylcyclohexanol (Composition 1 Composition 2 was prepared separately by way of mixing 2 kg of lead resinate, 0.2 kg of manganese linoleate, 0.25 kg of calcium linoleate, and 2 kg of the mixture of polymethylspirocyclosiloxanes as prepared in Example 1.  
  Prior to the use, both compositions were mixed to give a ready-to-use stencil-print colour.  
  As to its properties, the colour thus prepared was similar to that described in Example 1.  
 EXAMPLE 4 31 kg of pentaphthalic varnish (polypentaerythritolphthalate modified by castor oil and dissolved therein), 60 kg of a solution of phenol-formaldehyde resin (30 kg of the resin and 30 kg of ethylene-glycol monon.butylate) were mixed with 0.2 kg of tetrahydronaphthalene, 0.2 kg of decahydronaphthalene, 10 kg of an inorganic blue pigment and 2 kg of aluminium hydroxide. The mixture was charged into a vibrating mill and desintegrated therein to a fineness of about 5 to 10 mcm (Composition 1).  
  The above-mentioned resin has been obtained from phenol and formaldehyde at their molar ratio of 8:7 respectively by polycondensation in an acidic medium.  
  Composition 2 was separately prepared by way of mixing 7 kg of aluminium linoleate and 0.5 kg of the mixture of polymethylspirocyclosiloxanes prepared as in Example 1.  
  Prior to the use, both compositions were mixed to give a ready-to-use stencil-print colour.  
  As to its properties, the colour thus prepared was similar to that described in Example l.  
 EXAMPLE 5 kg of pentaphthalic varnish (polypentaerythritolphthalate modified by tung oil and dissolved therein), 15 kg of glyptal varnish (polyglycerolphthalate modified by linseed oil and dissolved therein), 60 kg of a solution of cresolformaldehyde resin (30 kg of the resin, kg of butylacetate and 10 kg of cyclohexanone) were mixed with 2.5 kg of decahydronaphthalene, 3 kg of an organic yellow pigment and 10 kg of aluminium hydroxide. The mixture was changed into an attrition mill and desintegrated therein to a fineness of 5 to 10 mcm (Composition 1).Composition 2 was separately prepared by way of mixing 1.5  
 kg of cobalt naphthenate. 1.5 kg of lead resinate and 3 kg of the mixture of polymethylspirocyclosiloxanes prepared as in Example 1.  
  Prior to the use both compositions were intermixed to give a stencil-print colour which had properties similar to those of the colour prepared in Example l.  
 What is claimed is:  
  l. A stencil-print colour which comprises a varnish (l) selected from the group consisting of linseed varnish which is essentially polymerized linseed oil, pentaphthalic varnish which is essentially polypentaerythritolphthalate modified by a vegetable oil and dissolved therein. polyglycerol-phthalate modified with a vegetable oil and dissolved therein, and a mixture of the above-mentioned varnishes; a resin (2) selected from the group consisting of phenol-formaldehyde resins and colophony-modified phenol-formaldehyde resins; metal salts (3) of higher carboxylic acids having more than six carbon atoms; pigments (4); an organic solvent (5); and a mixture of polymethylspirocyclosiloxanes (6) of the formula: ag o O CH $l 54- CH where n 2 to 7, with an average molecular weight of from 800 to 1,500; the colour components being taken in the following proportions (parts by weight):  
 varnishes l 100 resin (2) -125 metal salts (3) of higher carboxylic acids 2-25 pigments (4) 5-120 organic solvent (5) 75-175 mixture of polymethylspirocyclosiloxanes (6) 1-20.  
  2. A stencil-print colour as claimed in claim 1, wherein said varnish is pentaphthalic varnish which is essentially polypentaerythritolphthalate modified by a vegetable oil selected from the group consisting of linseed oil, tung and castor oil, and dissolved in said oil.  
  3. A stencil-print colour as claimed in claim 1, wherein said varnish is polyglycerol-phthalate modified by a vegetable oil selected from the group consisting of linseed oil, tung and castor oil, and dissolved in said oil.  
  4. A stencil-print colour as claimed in claim 1, wherein said resin is a high-molecular compound selected from the group consisting of diphenylolpropaneformaldehyde resin, colophony-modified diphenylolpropane-formaldehydc resin. phenol-formaldehyde resin and cresol-formaldehyde resin.  
  5. A stencil-print colour as claimed in claim 1, wherein said metal salts of higher carboxylic acids having more than six carbon atoms are salts selected from the group consisting of resinates. linoleates and naphthenates of calcium, manganese. lead, cobalt aluminium and mixtures thereof.  
  6. A stencil-print colour as claimed in claim 1, wherein said pigments are selected from the group consisting of organic and inorganic pigments and mixtures thereof.  
 tially polypentaerythritol-phthalate modified by linseed oil and dissolved in said oil in an amount of from to 50 parts by weight per 100 parts by weight of the varnishes contained in the colour.  
  10. A stencil-print colour as claimed in claim 8, which further includes pentaphthalic varnish which is essentially polypentaerythritol-phthalate modified by 7 linseed oil and dissolved in said oil in an amount of from 5 to 50 parts by weight per lOO parts by weight of the varnishes contained in the colour.  
  11. A stencil-print colour as claimed in claim 1, which further includes a filler selected from the group consisting of aluminium hydroxide and its mixture with barium sulphate in an amount of from I to 50 parts by weight per parts by weight of the varnishes used.  
  12. A stencil-print colour as claimed in claim 8, which further includes a filler selected from the group consisting of aluminium hydroxide and its mixture with barium sulphate in an amount of from 1 to 50 parts by weight per 100 parts by weight of the varnishes used.  
  13. A stencil-print colour as claimed in claim 9, which further includes a filler selected from the group consisting of aluminium hydroxide and its mixture with barium sulphate in an amount of from I to 50 parts by weight per 100 parts by weight of the varnishes used.  
  14. A stencil-print colour as claimed in claim 10, which further includes a filler selected from the group consisting of aluminium hydroxide and its mixture with barium sulphate in an amount of from 1 to 50 parts by weight per 100 parts by weight of the varnishes used.