| 摘要 |
1,163,726. Photographic light-sensitive silver halide materials. EASTMAN KODAK CO. Sept. 16, 1966 [Sept. 17, 1965], No. 41502/66. Heading G2C. A light-sensitive silver halide material, in which the emulsion contains at least 50 mole per cent of silver chloride, contains in the emulsion or an adjacent layer a water-soluble siliconcontaining block copolymer of polyoxypropylene and polyoxyethylene in which the main polymer chain contains up to 15% by weight of silicon atoms, the polyoxypropylene content of the copolymer has an average molecular weight of 800 to 3, 000 and the polyoxyethylene units constitute 10 to 70 % by weight of the copolymer. The polymers may be those obtained by reacting a dialkyl siloxane e. g. dimethyl siloxane with a compound of the formula:- where Y is an organic radical of valence x1, n and x are integers greater than 1 so that the polyoxypropylene content of the copolymer has a molecular weight of 800-3, 000, E is a polyoxyethylene chain and R is hydrogen, alkyl, alkyl carbonyl or aryl carbonyl. The emulsion may also contain onium salts such as N:N<1>-ethylenedioxymethylpyridinium perchlorate. The materials are lith materials of improved speed of development, contrast and dot-quality. |
