GB544135A - Improvements in colour photographic materials - Google Patents

Abstract

544,135. Photographic materials. KODAK, Ltd., and KNOTT, E. B. July 23, 1940, No. 12064. [Class 98 (ii)] Photographic material has one or more layers on one or more supports, at least one layer of which is a light-sensitive layer having a colloid binder containing a salt of a salt-forming water-insoluble colloid and a dye-forming substance, e.g. a colour coupler or leuco dye, which does not form a salt with the water-insoluble colloid. The light-sensitive layer may be silver halide gelatine or collodion emulsion layer. The salts may be water-soluble salts such as those of alkali metals, ammonium, ethanolamine, or other strong organic bases, or waterinsoluble salts such as those of alkaline earth or other metals, e.g. magnesium, calcium, strontium, barium, aluminium, cadmium, manganese, zinc, cerium, nickel, cobalt, and thorium, or of organic bases of complex structure or high molecular weight such as quinine or cinchonine. The salts may be soluble in organic solvents. The saltforming colloid may be a natural resin, e.g. whole, hard, soft, or hydrolyzed lac; colophony; dammar; mastic; and sandarach; or a synthetic resin such as polyhydric alcohol-polybasic acid' resins; or cellulose esters of polybasic acids having free carboxylic groups, e.g. cellulose acetatephthalate or cellulose phthalate. The material may have two or more emulsion layers on a single support, preferably all on one side. Colour photographic material of the types referred to in Specification 503,752 may be used. In examples (1), an alcoholic solution of p-nitrophenylacetonitrile and the sodium salt of colophony is added to a silver halide emulsion; (2), as in (1), using the sodium salt of soft lac; (3), cadmium nitrate is added to the emulsion, followed by the addition of an alcoholic solution of 1-phenyl-3-methyl-5-pyrazolone and the sodium salt of colophony; and (4), as in (3), using nickel chloride instead of cadmium nitrate. Specifications 399,713, 410,286, 458,664, 458,665, 478,942, 478,983, 478,989, 478,990, 493,952, 496,196, 496,245, 503,863, 511,180, 519,695, 524,040, 524,154, 524,554, 524,555, 525,874, 525,875, 527,493, 531,246, 531,312, 536,673, 536,939, 537,696, 537,921, 538,914, 540,525, 541,558, 541,589, and 544,134 also are referred to.