Patent GB-524555-A (GB)
Title: Improvements in colour photographic materials
IPC: G03C7/388
Filed: 1939-01-23
Abstract: 524,555. Colour photography. KODAK, Ltd. (Eastman Kodak Co.). Jan. 23, 1939, No. 10140/40. Divided out of 524,154. [Class 98 (ii)] In colour photographic material having a plurality of differentially colour-sensitive emulsions on one or more supports, at least one of the emulsions consists of silver halide emulsified in a water-soluble binder such as gelatine having distributed through it fine discrete particles of a water-insoluble water-permeable cellulose derivative containing a colour coupler. In material with a single support, all the emulsions on that side of the support on which more than one emulsion is located contain the particles. In multilayer single support material, at least one of two adjacent layers contains the particles. At least one layer may be an emulsion of silver halide in a water-soluble water-permeable binder containing a colour coupler such as is described in Specification 524,154. A layer of water-soluble binder containing particles of gelatino-silver halide emulsion containing the colour coupler and any sensitizer required within an envelope of the water-insoluble waterpermeable binder may be employed. A transparent or opaque support of cellulose nitrate, cellulose acetate, or paper may be employed. The cellulose derivative may be cellulose nitrate, acetate acetate-phthalate, acetate-butyrate, or ether, or may be a known collodion solution. The water-soluble binder may also be agar-agar. The processing baths may contain organic liquids or wetting agents to facilitate penetration. The cellulose derivative may contain porosity modifiers such as plasticizers, or if necessary porosity may be decreased by hardening with chromium salts. Numerous colour couplers such as are described in Specification 524,154 are referred to. The colour produced need not be complementary to the sensitivity. Light-scatter may be reduced as described in Specification 524,154. The particles may be pre-formed. The silver halide employed may be silver bromide, chloride, or chlorobromide. Acid sensitizing dyes are preferable. A sound record may be recorded in one or more of the picture emulsions or in a separate emulsion. Antihalation and filter layers may be provided. Two-layer material comprises a lower red-sensitive emulsion layer containing cellulose nitrate particles containing the colour coupler 1-hydroxy-2-N- methyl, N-phenyl-naphthylamide, a yellow filter layer, and an upper green-sensitive emulsion containing cellulose nitrate particles containing a mixture of n-propyl-p-benzoylacetaminobenzenesulphonate and 2-cyanacetylnaphthalene-sulphon-N-methyl-anilide. The material may also be dyed yellow throughout. Similar three-layer material containing appropriate colour formers are described. The material may be colour developed to a negative directly or after developing to black and white and bleaching or may be colour developed to a positive by reversal. The emulsions may be on the same or opposite sides of the support. Specifications 440,032, 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, 509,707, and 524,554 also are referred to.