Photographic element
United States Patent Tsuji et a1.  
 [ PHOTOGRAPHIC ELEMENT [75] Inventors: Nobuo Tsuji; Tatsuya Tajima;  
 Yoshinori Tsuchiya, all of Minami Ashigaramachi, Japan [73] Assignee: Fuji Photo Film Co., Ltd.,  
 Minami-Ashigara-shi, Kanagawa, Japan [22] Filed: Jan. 19, 1972 [21] Appl. No.: 219,179  
 [30] Foreign Application Priority Data Jan. 19, 1971 Japan 46-1321 [52] U.S. Cl 96/87 R; 96/85; 96/67; 96/114;96/114.4;96/114.5;96/114.7; 117/161 R; 117/161 UC; 117/161 C [51] Int. Cl G03c 1/78 [58] Field of Search 117/161 R, 161 UC, 161 C; 96/85, 87, 67, 114, 114.4, 114.5, 114.7  
 [56] References Cited UNITED STATES PATENTS 2,964,403 12/1960 Beekman et al. 96/85 2,980,534 4/1961 Printy et al. 96/85 3,085,897 4/1963 Priest et al 96/114 3,161,519 12/1964 Alsup 96/85 3,165,412 l/1965 Minsk et al..... 96/1 14 3,369,901 2/1968 Fogg et al. 96/85 3,397,988 8/1968 Van Paesschen... 96/85 3,425,857 2/1969 Bacon et al 96/85 3,635,715 1/1972 Grabhofer et al. 96/114 3,723,127 3/1973 Yano et a1. 96/114 51 Apr. 15, 1975 Primary Examiner-Norman G. Torchin Assistant Examiner-Edward C. Kimlin Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn &amp; Macpeak [5 7] ABSTRACT A photographic element for use in silver halide photography having a silver halide emulsion layer, a protective layer, a subbing layer or a diffusion-transfer image-receiving layer, each using gelatin as the main binding component, in which into one of said layers are incorporated a nonionic water-soluble polymer and a phase separation inhibitor containing the (3| (Ill (Ill Cll XIOCH COOH COOl&#39;l nml (ill (Ill IOOH COOR groups in 50, 50 X and X molar proportions, respectively, X being not more than 50 and R being an alkyl group having from 1 to 4 carbon atoms.  
 The photographic element has reduced propensity to curling and to becoming sticky after stabilization processing.  
 14 Claims, No Drawings PHOTOGRAPHIC ELEMENT BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to photographic elements, and more particularly to composition of layers to be provided on a photographic element support.  
 2. Description of the Prior Art Photographic elements in general comprise a support material such as paper, a synthetic resin film, a glass or metallic plate, with a subbing layer optionally being provided thereon for the purpose of enhancing the adhesivity between the support and photographic layer adjacent thereto, together with a silver halide emulsion layer, usually with a protective layer provided thereon to prevent damage to said emulsion layer, the latter two layers being applied onto the surface of the foregoing support or subbing layer. Furthermore, as one special kind of photographic material there is an imagereceiving element used in the diffusion transfer photographic process, which element comprises an imagereceiving layer having incorporated therein a catalytic substance, i.e. silver deposits or so-called development nuclei, in a dispersed form for reduction of a soluble silver complex transported by diffusion from a photographic light-sensitive element.  
  As the binding agent for these photographic elements, gelatin has heretofore been used in almost all cases due to its outstanding photographic and physical properties. Since gelatin is a natural substance, however, its use has suffered from the disadvantage that the properties of gelatin largely depend upon the raw materials and manufacturing processes used to form it; and often it is therefore not possible to insure constant quality in the finished product. Besides such a disadvantage, the use of gelatin presents some other problems. For instance, it is sensitive to changes in temperature and humidity and tends to curl. Furthermore, in the stabilization process wherein a photographic element is processed in a stabilizing solution containing ammonium thiocyanate, the surface of a gelatin film which constitutes a photographic layer becomes sticky after stabilization.  
  Recently, in an attempt to eliminate these defects, various kinds of synthetic polymers have been proposed as substitutes for gelatin as a binding agent for photographic layers. These include, for example, polyvinyl alcohol, polyacrylamide, polyvinyl pyrrolidone poly-l-vinyl-2-methylimidazole, sodium polyacrylate,  
 Unit No.  
  2 an acrylamide-l-vinyl-2-methylimidazole copolymer and an acrylamide-l-vinyl-2-methylimidazole-acrylic acid copolymer. These synthetic polymers, however, are not superior to gelatin in various other photographic and physical properties, so that in practice gelatin is used.  
  It has been attempted to employ gelatin with such synthetic polymers, thereby maintaining the superior properties of the gelatin and compensating for the defects of the same by means of the properties of the synthetic polymers. However, when a portion of the gelatin is replaced by a nonionic water-soluble polymer, complete mixing of both components in optional proportions cannot be effected and phase-separation takes place.  
  To attempt to overcome this effect, a method has been proposed wherein a third substance is added to prevent the phase separation. For example, in Japanese Patent Publication No. 4,272/ &#39;64 there is described the use of a methyl vinyl ether maleic anhydride copolymer (hereinafter referred to as MVE/MA) or an amide or ester thereof as a phase-separation inhibitor upon using gelatin with polyvinyl alcohol.  
 SUMMARY OF THE INVENTION We have found that the compounds disclosed hereinafter are extremely effective as phase-separation inhibitors upon admixing gelatin with nonionic polymers, we have also confirmed the following advantages: the coating composition prepared using such compounds can be applied onto a support more uniformly than in the case of using the prior art phase-separation inhibitor, i.e., the above-described copolymer (MVE/MA) or an amide or ester thereof; the photographic elements produced have little tendency to curl, and they show little tendency to be sticky after stabilization, if such is used.  
  Thus, the present invention provides a photographic element comprising a support having thereon at least one layer comprising gelatin, a nonionic water-soluble polymer and a polymer, said polymer comprising mole of vinyl acetate, (SO-X) mole of maleic acid and X mole of half alkyl ester of maleic acid, wherein X is 0; X 50 and the alkyl group has 1 to 4 carbon atoms.  
  The polymer of the present invention, which can be employed as an inhibitor for phase-separation between gelatin and the nonionic water-soluble polymer, may be characterized by the following chemical units and the specified proportion thereof.  
 Atomic groups Proportion contained -CH (III-l 50 molar &#34;/0 QCOCI-I2 CH CH r50 X) molar (LOCI-I IOOII CH CH X molar 7o COOH COOR (X being not more \R being an alky] than 50) g roup having from 1 to 4- carbon atoms.)  
  The nonionic water-soluble polymers which may be used in accordance with the present invention include polyvinyl alcohols, polymers of acrylamide or its derivatives such as acrylamide, N-methylacrylamide, N- ethylacrylamide, N, N-dimethylacrylamide, N, N- diethylacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-morpholinoacrylamide, or N-morpholinomethylacrylamide, the corresponding polymers of methacrylamide or its derivatives, polyvinyl methyl ethers, polyvinyl pyrrolidones, polyvinyl oxazolidones, polyvinyl caprolactams, soluble starch and cellulosic derivatives such as hydroxyethyl cellulose or methyl cellulose. Besides these homopolymers, there may also be used water-soluble copolymers consisting of the monomer units mentioned above.  
  Among the nonionic water-soluble polymer polyvinyl alcohol is the most typical one. Any known polymer which is used together with gelatin in the photographic art may be employed.  
  The phase-separation inhibitors used according to the present invention may be obtained by synthesizing a 1:1 (polymerization ratio) copolymer of vinyl acetate and maleic anhydride by means of any conventional radical polymerization method, and heat-treating the copolymer in water or an alcohol having from 1 to 4 carbon atoms to effect hydrolysis or alcoholysis of the same. The decomposition reaction may also be partially carried out to produce the half ester. By the procedure, the  
 CH CI-l cooH COOl-l group which initially occupies 50 molar of the copolymer is converted into the CH CH COOH COOR group by X molar In the present invention, the above-described decomposition reaction can be eliminated, so that the range of X is X E 50. The properties of the polymer are substantially not affected on the proportion of X.  
  Several examples of such phase-separation inhibitors will be given below where the values of the intrinsic viscosity are taken in a methanolic solution of each phaseseparation inhibitor at 300C.  
 Intrinsic viscosity 1 Unit 1 50 molar &#34;/1 0.64  
 Unit 2 50 molar &#34;/1 ll Unit I 50 molar &#34;/1 0.73  
 Unit 3 50 molar 71 (R ethyl) lll Unit 1 50 molar /1 Unit 2 30 molar 71 0.42 Unit 3 20 molar 7:  
 (R n butyl) (R means alkyl group of the half ester of anhydride (See page 4), it relates to unit 3. not unit l.)  
 [V Unit 1 50 molar 7:  
 Unit 2 20 molar &#34;/1 0.52 Unit 3 30 molar &#34;/1 (R methyl) According to the present invention, gelatin and the nonionic water-soluble polymer can be used in admixture with the phase-separation inhibiting polymer in photographic layers. These photographic layers include not only a light-insensitive layer such as a protective or uppermost layer, a subbing or under-coated layer, an image receiving layer for diffusion-transfer process,  
 which layer may also contain nuclei for precipitating silver, such as colloidal silver or heavy metal sulfides, but also a light-sensitive layer such as a light-sensitive silver halide emulsion layer. The phase-separation inhibiting polymer of the present invention may be added to a mixture to be coated at any stage before coating. The polymer may also be added to a silver halide emulsion during preparation thereof.  
  The proportions of gelatin, nonionic water-soluble polymer and phase-separation inhibiting polymer may be varied depending upon the specific requirement of the photographic layers being produced and the specific compound to be used. In general, the preferred proportions are set out below.  
 gelatin about 5 about by weight nonionic water-soluble about about 15% by weight polymer phaseseparation about 5 about 15% by weight inhibitor The phase-separation inhibitors used according to the present invention may be of any molecular weight, although it is most preferred to use those having an intrinsic viscosity [17], as measured in a methanolic solution at 30C., of about 0.05 to about 5.0, preferably about 0.3 to about 2.0.  
  Suitable support material include any of those used in photography such as cellulose acetate, synthetic resins such as polyesters, polystyrenes or polycarbonates, paper, or resin coated paper such as polyethylene coated paper.  
  The copolymers used according to the present invention remarkedly improve the compatibility between gelatin and nonionic water-soluble polymers, and are extremely effective for the prevention of phaseseparation which often takes place.  
  The present invention can be applied to varied silver halide emulsions using silver chloride, silver bromide, silver chlorobromide, silver iodobromide and/or silver chloroiodobromide, and mixtures thereof.  
  The emulsions to which the present invention may be applied may be chemically sensitized by any conventional method, for example using labile-sulfur containing compounds such as ammoninum thiosulfate or allylthiourea (see, for example, P. Glafkindes, Chimie Photographique; 2 eme Edition Photocinema, Paul Montel Paris, 1957, pages 297-299); gold compounds such as complexes of monovalent gold and thiocyanic acid (see lbid., page 301) or any combination of these compounds. The emulsions may be optically sensitized by incorporating thereinto spectral sensitizers such as cyanine or merocyanine dyes (see, for example, Shinichi Kikuchi, et al, Kagaku-Shashin Binran, Maruzen Co., Ltd, 1959, pages l5-24). Furthermore, they may be stabilized by any stabilizers well known in the art, for example, heterocyclic compounds such as benzotriazole, l-phenyl-5-mercaptotetrazole, 4-hydroxy-6- methyl-l,3,3a,7-tetrazaindene or 6-thioctic acid, mercury compounds such as mercumallylic acid (see Japanese Patent Publication No. 22, 063/64), or benzenesulfonic acid. In addition, the emulsions may be hardened using hardening agents such as formaldehyde, mucochloric acid, chromium alum or triazine derivatives (see, for example, Belgian Pat. No. 641,044), or a combination of these hardeners with hardening adjuvants such as resorcin or resorcin aldehyde. Into the emulsions there may be incorporated surface active the application of said emulsions. Furthermore, the emulsions may be sensitized using polyalkylene oxide derivatives such as condensation products of an alkylphenol and polyethylene oxide.  
  The emulsions prepared in accordance with the present invention can be used, after the addition of couplers, in the manufacture of natural color photographic films or papers. Furthermore, by increasing the ratio of the water-soluble polymer to gelatin, the developed film can be removed by means of rinsing, so that it may be used as a negative layer for use in the so-called multi-layer diffusion transfer process (C. E. Neblette, Photography, its Materials and Processes, 6th Edition, D. Van Nosttand Co., Princeton, N.J., 1962, pages 371-373) The present invention will now be further illustrated by the following non-limitative examples.  
 EXAMPLE 1 A silver halide photographic emulsion thickness (4 microns) was prepared which contained 20 g. silver chloride and g. gelatin, and was divided into three equal portions A, B and C. lnto each portion there was added the following solutions, respectively:  
 Emulsion A200 cc. of a 10 weight aqueous solution of gelatin.  
 Emulsion B200 c.c of a 10 weight aqueous solution of polyvinyl alcohol.  
 Emulsion C 180 c.c. of a 10 weight aqueous solution of polyvinyl alcohol plus 20 c.c of- 10 weight 7: solution of a phase-separation inhibitor (1) in water: methanol (1:1 by weight).  
  Emulsion A, B and C each were thoroughly agitated and then applied onto a photographic baryta-coated paper (95 g./m. to give the corresponding photographic paper, i.e. specimens A, B or C, respectively. These specimens were each exposed to light, processed in a developer and fixing solution having the following compositions, cut into a circular form of 10 cm. in diameter and dried for 24 hours at a temperature of 25C and a relative humidity of 50% (Condition 1), or at a temperature of 25C and relative humidity of 20%,  
 (Condition 2 Water to make 1,000 c.c.  
  After drying each specimen under the conditions mentioned above, the curling value was determined by measuring across the center of the circular form the distance (x cm) between the tips which were closest upon the curling, and the value (10 x) cm was takenas the curling value. The results of the measurement are shown in Table l.  
 Table 1 Specimens Condition 1 Condition 2 A 5.2 cm. 9.8 cm. B (Separation took place in the emulsion phase and uniform application was impossible.) C 0.4 cm. 1.2 cm.  
  As is evident from Table l, the photographic paper using the compounds according to the invention (Specimen C) showed extremely low curling values as compared with the photographic paper using gelatin alone (Specimen A). No changes were found in the photographic properties between Specimens A and C.  
 EXAMPLE 2 A silver halidegelatin emulsion (thickness: 4 microns) was prepared which contained 20 g. silver chloride and 10 g. gelatin, and, after addition of 10 g. hydroquinone as a developing agent, was divided into two equal portions A and B, into which were added the following solutions, respectively:  
 Emulsion A20O c.c. ofa 10 weight aqueous solution of gelatin.  
 Emulsion B180 c.c. ofa 10 weight aqueous solution of polyvinyl alcohol plus 20 c.c. of a 10 weight aqueous solution of a phase-separation inhibitor Emulsions A and B were each thoroughly agitated and applied onto a photographic base paper of g./m. to give photographic papers A and B, respectively, for use in a stabilization process. These photographic papers were each developed in an activator having the composition shown below, after which they were processed in a stabilizing solution containing NH SCN and then dried in a desiccator kept at a temperature of 25C and a relative humidity of 50%. After drying, comparison was made of the stickiness of the photographic papers emulsion surface, whereby it was found that the stickiness of Specimen B according to thepresent invention was extremely low as compared to Specimen A using gelatin alone, and the curling value of Specimen B was small, as in Example 1, and satisfactory.  
 Composition of the activator:  
 Anhydrous sodium sulfite Sodium hydroxide Potassium bromide Water to make 1,000 c.c.  
 renu- EXAMPLE 3 A silver chlorobromide emulsion was prepared which&#39; Formulation of the protective layer composition:  
  atin P.V.A. Phase-separation inhibitor (11) Water to make 1,000 c.c.  
  g. 15 g. 1.5 g.  
 The photographic paper was subjected to stabilization processing using the same activator and stabilizing solution as in Example 2, after which the stickiness of the photographic papers surface was observed to be satisfactory.  
 EXAMPLE 4 Colloidal nickel sulfide nuclei were incorporated into an aqueous solution having the composition as shown below and applied onto a photographic base paper of 85 g./m On top of the coating layer there was further applied a stripping layer mainly containing sodium alginate to give an image-receiving paper for use in the silver salt diffusion transfer process. The image-receiving paper was dipped for several seconds in a developer (composition is shown below) for use in the silver salt diffusion transfer process while held in tight surface contact with a negative paper having a silver halide emulsion layer for use in the diffusion transfer process, which negative paper had been exposed to light. The image-receiving paper, after being separated from the negative paper after 30 seconds showed an extremely low curling tendency and was satisfactory.  
  Amount of nickel sulfide in the layer was 0.6 mg/m*. Amount of sodium alginate in the layer was 0.2 g/m Composition of the protective colloid solution into which colloidal nuclei are to be incorporated:  
 Gelatin P.V.A. Phase-separation inhibitor (1) Water to make 1.000 c.c.  
 Composition of the developer for use in the silver salt diffusion transfer process:  
 Anhydrous sodium thiosulfate Potassium sulfite Potassium bromide Hydroquinone Phenidone l Sodium hydroxide Water to make 1,000 c.c.  
 EXAMPLE 5 A silver halide-gelatin emulsion was prepared which contained 20 g. AgCl and g. gelatin, and was divided into four equal portions, into which the following compounds were added, respectively:  
 Sample Substances added can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.  
 What we claim is:  
  l. A photographic element comprising a support having thereon at least one layer consisting essentially of gelatin, a nonionic water-soluble polymer which is photographically compatible with said gelatin and a polymer which is a phase-separation inhibitor for said gelatin and said nonionic water-soluble polymer, said polymer comprising mole of vinyl acetate, (50 X) mole of maleic acid and X mole of a half alkyl ester maleic acid, wherein X is 0 X 50 and the alkyl group in said half alkyl ester has 1 to 4 carbon atoms, wherein the proportion of said gelatin, said nonionic water-soluble polymer and said polymer is 5 to 70, 90 to 15 and 5 to 15 by weight, respectively, said polymer being a phase-separation inhibitor.  
  2. The photographic element as claimed in claim 1 wherein said nonionic water-soluble polymer is selected from the group consisting of polyvinyl alcohol; polymers of an acrylamide or methacrylamide, polyvinyl methyl ether, polyvinyl pyrrolidone, polyvinyl oxazolidone, polyvinyl caprolactams, soluble starch and cellulose derivatives.  
  3. The photographic element as claimed in claim 1 wherein X is 50, and has an intrinsic viscosity, as measured in a methanolic solution at 30.0C., of 0.64.  
  4. The photographic element as claimed in claim 1 wherein said phase-separation inhibitor contains vinyl acetate and the half alkyl ester of maleic acid in which alkyl is the ethyl group in 50 molar proportions, respectively, said inhibitor having an intrinsic viscosity, as measured in a methanolic solution at 300C, of 0.73.  
  5. The photographic element as claimed in claim 1 wherein said phase-separation inhibitor contains vinyl acetate, maleic acid, and the half alkyl ester of maleic acid, and maleic acid in which alkyl is the n-butyl group in 50, 30 and 20 molar proportions, respectively, said inhibitor having an intrinsic viscosity, as measured in a methanolic solution at 300C, of 0.42.  
  6. The photographic element as claimed in claim 1 wherein said phase-separation inhibitor contains vinyl acetate, maleic acid, and the half alkyl ester of maleic A 200 c.c of a I07: aqueous solution of gelatin B A mixture of 180 c.c. of a 10% aqueous solution of hydroxyethyl cellulose and 20 c.c. of a [07: aqueous solution of phase- 20 c.c. of a 10% aqueous solution of phase-separation inhibitor (lV) (Substances according to the invention).  
 acid in which alkyl is the methyl group in 50, 20 and 30 molar proportions, respectively, said inhibitor having an intrinsic viscosity, as measured in a methanolic solution at 300C, of 0.52.  
  7. The photographic element as claimed in claim l wherein said phase-separation inhibitor has an intrinsic viscosity as measured in a methanolic solution at 300C in the range of from 0.05 to 5.0.  
  8. The photographic element as claimed in claim 1 wherein said phase-separation inhibitor has an intrinsic viscosity as measured in a methanolic solution at 30.0C in the range of from 0.3 to 2.0.  
 9. The photographic element as claimed in claim 1,  
 wherein said at least one layer is a subbing layer.  
  13. The photographic element as claimed in claim 1, wherein said at least one layer is an image receiving layer for a diffusion-transfer process.  
  14. The photographic element as claimed in claim 2, wherein said cellulose derivative is hydroxyethyl cellulose or methyl cellulose.