Patent GB-524154-A (GB)
Title: Improvements in colour photographic materials
IPC: G03C7/388
Filed: 1939-01-23
Abstract: 524,154. Colour photography. KODAK, Ltd. (Eastman Kodak Co.). Jan. 23, 1939, No. 2265. [Class 98 (ii)] Colour photographic material has on a single support one or more layers consisting.of or containing three differentially colour-sensitive emulsions of silver halide in water-insoluble water - permeable binder containing colour coupler and having a water-soluble colloid such as gelatin between emulsions which would otherwise be contiguous. Colour couplers extremely insoluble in water or in aqueous alkaline solutions may be employed, and may be dissolved in water-immiscible organic solvents. The colour couplers employed are preferably more soluble than 1:4-di-(w-benzoylacetamino)- benzene, but less soluble than 2:4-dichlor-5- benzoylamino-1-naphthol in an aqueous solution maintained between pH 8.5 and pH11. Examples of such colour couplers of limited solubility are 2:2<SP>1</SP>-dihydroxy-5:5<SP>1</SP>-dibromostilbene, p:p<SP>1</SP>-di-(2-hydroxybenzamido)-diphenylmethane, sebacic acid-di-(2-hydroxyanilide), 1-naphthol-2-carboxylic acid-α-naphthalide, 5- phenoxyacetamino-1-naphthol, 1-4-phenyJenebis-3-(1-phenyl-5-pyrazolone) ; 2-cyanoacetyl- 5-benzoylaminocoumarone, 2-cyanoacetyl - #- naphthofuran, cyanoacet-#-naphthalide, N- phenyl, N-(p-acetoacetaminophenyl)-urea, p:p<SP>1</SP>- diacetoacetaminodiphenylmethane, benzoylacet-2:5-dichloranilide, p:p<SP>1</SP>-di-(acetoacetamino) - diphenyl, and 4:4<SP>1</SP>-di-(acetoacetamino)-3:3<SP>1</SP>- dimethyldiphenyl. The water-insoluble waterpermeable binders may be cellulose esters such as a nitrate, an acetate, an acetate-butyrate or an acetate-phthalate, or a cellulose ester, or a natural resin such as gum mastic, gum dammar, gum sandarach, or gum elemi, or a synthetic resin such as polystyrene, polymethyl methacrylate, polyvinyl acetal, polyvinyl acetate or a coumarone-indene resin. The blue-sensitive emulsion may be silver chloride or chlorobromide, and may be sensitized to blue, and the red and green sensitized emulsions may be silver bromide. Basic sensitizing dyes such as pinacyanol or the neothiazolocarbocyanine derived from 2:4-dimethylthiazol are preferably employed for cellulose ester emulsions, and acid sensitizing dyes such as erythrosin for gelatin emulsions. A sound image may be recorded in one or more of the picture emulsions or in a separate emulsion. Anti-halation and filter layers may be provided. The three layers may be silver halide collodion emulsions. The colours produced on colour development may or may not be complementary to the sensitivity. At least one layer may comprise a Water-soluble binder having dispersed therein pure discrete particles of water-insoluble water-permeable binders containing silver halide and a colour coupler. The colour-processing bath may contain organic liquids or wetting agents to facilitate penetration. The water-insoluble binders, particularly cellulose binders, may contain plasticizers. The water-insoluble binder may be hardened with chromium salts. Light scatter may be reduced by coating the surface with a varnish, by dissolving protruding particles with an organic solvent, or by incorporating either in the water-soluble or water-insoluble binder a substance tending to reduce the difference between the relative refractive indices. A solution of the water-insoluble binder in a volatile organic water-miscible solvent may be dispersed in an aqueous solution of the watersoluble binder and the solvent removed by heating or under reduced pressure. A disposing agent may be added to the water-soluble binder before the dispersion. The particles may be pre-formed by spraying or by emulsifying in water or water plus water-miscible organic solvent, preferably with an emulsifying agent and then incorporating in gelatine or gelatinesilver halide emulsion. Material containing collodion emulsion particles containing colour coupler dispersed in gelatin is described. Other examples are given of (a) a single-layer material prepared by adding to the batches of collodion silver halide emulsion, one of which is red-sensitized with pinacyanol or the neothiazolocarbocyanine derived from 2:4-dimethylthiazole and another green-sensitized with erythrosin, the colour couplers 5:7-dibromo-8- hydroxyquinoline, p-phenylbenzoylacetonitrile, and #-naphthoylacetone respectively, and adding minute dried particles of these three collodion emulsions in substantially equal quantities to an aqueous gelatin solution and coating on a support ; (b) materials prepared similarly to (a) but using centrifuged gelatin silver halide grains re-emulsified in cellulose derivative ; (c) three-layer material comprising the collodion emulsions of (a) coating in superimposition on the same side of a support but separated by thin gelatin layers, the cellulose nitrate being replaceable by a mixture of cellulose acetate- and acetate-phthalate ; (d) three-layer material comprising three collodion silver halide emulsions separated by gelatin layers and containing- colour couplers ; (e) two-layer material comprising a gelatin layer containing a mixture of fine particles of red- and green-sensitized collodion emulsions and containing different colour couplers and a gelatin layer containing particles of a collodion emulsion containing a colour coupler ; (f) two-layer material similar to (e) in which the second layer is a collodion emulsion containing a colour coupler, preferably separated from the first layer by a thin gelatin layer. The emulsion layers may be on different sides of the support. Specifications 408,273, [Group IV], 447,748, 458,664, 458,665, 474,353, 475,784, 475,786, 478,933, 478,934, 478,942, 478,983, 478,984, 478,985, 478,986, 478,989, 478,990, 478,991, 493,952, 496,196, 496,245, 505,834 and 509,707 are referred to.