Photographische Gelatine-Silberhalogenidemulsion

Polymers containing repeating units of formula or of formulae -CH(COOM)CH(COA)- and -CH(OR)CH2-, optionally together with -CH(COOC2H5)CH2- in which formulae R1 is H or CH3, A is NHCHR1COOR2, where R1 is H, CH3, C2H4COOC2H5 or C2H4SCH3, R2 is CH3, C2H5, NHCH2COOC2H5 or NHCH2COOCH3 R is C2- 4 alkyl and M is a cation, may be prepared by reacting polyacrylic anhydride, polymethacrylic anhydride, or a copolymer of maleic anhydride and a C2- 4 alkyl vinyl ether, optionally together with ethyl acrylate, with an amino acid ester of formula NH2CHR1COOR2. The reaction may be effected in an inert solvent. Preferred amino acid esters are ethyl alanine, ethyl glycylglycine, ethyl glycine, ethyl methionine and ethyl glutamate. The polymers may be used in silver halide emulsions in the preparation of photographic films. Examples describe the polymerization of (1) acrylic anhydride and (3) methacrylic anhydride in dioxane in the presence of azodiisobutyronitrile; the copolymerization of (5) ethyl vinyl ether, ethyl acrylate and maleic anhydride and (6) ethyl vinyl ether and maleic anhydride in acetone in the presence of azodiisobutyronitrile; and the reaction in dimethylformamide of polyacrylic anhydride with (1) ethyl alanine, (2) ethyl glycylglycine and (9) ethyl methionine; of polymethacrylic anhydride with (3) ethyl glycine, (4) ethyl alanine, (8) ethyl methionine and (12) ethyl glutamate; of an ethyl vinyl ether/ethyl acrylate/maleic anhydride terpolymer with (5) ethyl alanine, (7) ethyl glycine and (11) ethyl methionine; and of an ethyl vinyl ether/maleic anhydride copolymer with (6) ethyl glycine and (10) ethyl methionine.