GB496049A - Improved manufacture of light-sensitive photographic preparations - Google Patents

Abstract

496,049. Photographic light-sensitive materials; colour photography. GROVES, W. W. (I. G. Farbenindustrie Akt.-Ges.) May 20, 1937, No. 14063. [Class 98 (ii)] Photographic light-sensitive materials, for example silver halide emulsions, chromate sensitized materials, diazotype layers, and bleaching-out layers are made using as the binding agent, alone or in admixture with another colloid binding agent, a water-sensitive hydrolysed cellulose ester which is soluble in a solvent mixture having a content of water of at least 20 per cent. The support may be of cellulose derivative, regenerated cellulose, paper, glass, metal, or artificial resin. Solvents such as acetone, alcohols such as methanol, an ester such as methyl methoxyacetate, or a glycol mono-ether may be added to the material to facilitate adhesion to the support. The hydrolysed cellulose acetate may be dissolved in a mixture of water and acetone, glycol mono-methyl ether, dioxane, glycolchlorhydrin, glycid or epichlorhydrin, silver halide produced in the solution, and the emulsion subjected to ripening, sensitizing, and stabilizing treatment. Ultrasonic vibrations and peptizing treatment may be applied in the preparation of the emulsion. Ripeners, such as the inorganic or organic sulphur compounds described in British Specifications 236,211, 255,846, 283,222, and 283,223, [all in Class 98 (ii)], or the degradation products and extracts from albuminous bodies described in British Specifications 258,237, 259,538, and 259,926, [all in Class 98 (ii)], and in German Specification 433,043, restrainers and stabilizers such as the thiazole compounds described in British Specification 246,800, [Class 98 (ii)], imidazole, as described in British Specification 271,475, [Class 98 (ii)], organic compounds having NH- and SH- groups which form silver salts with a solubility lower than that of silver chloride, as described in British Specification 305,143, [Class 98 (ii)], secondary and tertiary amines as described in German Specification 558,419, secondary and tertiary aliphatic amines having more than 6 carbon atoms as described in British Specification 419,579, salts of sulphuric and selenic acids as described in British Specification 441,625, cyclocarbamides as described in British Specifications 337,323, [Class 98 (ii)], and 350,996, and thiopyrazolones as described in U.S.A. Specification 1,954,334, and blueblack toning substances such as benzimidazole and derivatives thereof, benztriazole and derivatives thereof, alkaloids, quinine sulphate, and quinidine may be added to the emulsion.