| 摘要 |
1,188,023. Photographic silver halide emulsions. EASTMAN KODAK CO. March 31, 1967 [April 4, 1966], No.14860/67. Heading G2C. A photographic silver halide emulsion contains as an anti-foggant a vinyl polymer in which at least 5 per cent of the vinyl units contain a sulphate ester alkali-metal or ammonium salt group. Specified polymers and copolymers are copoly (vinyl alcohol, vinyl hydrogen sulphate) ammonium salt, copoly-(vinyl alcohol, vinyl hydrogen sulphate, vinyl 2-hydroxy-5-sulphophenyl carbonate) sodium salt, the mixed ammonium-sodium salts of copoly- (α-sulphatomethyl-ethyl acrylate,α-hydroxymethylethylacrylate) and copoly-(N-#-sulphatoethylacrylamide, #-hydroxyethylacrylamide). In some emulsions the polymers act as speed-increasing compounds.
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