Color photographic material combining improved sensitivity with good storage stability is chemically ripened with a short chain xanthate and spectrally sensitized with a cyanine dye

摘要

At least one of the blue-, green- and red-sensitive silver halide emulsions in a photographic material is spectrally-sensitized with a cyanine dye and chemically-sensitized with a short-chain xanthate. At least one of the blue-, green- and red-sensitive silver halide emulsions in a photographic material is spectrally-sensitized with a cyanine dye of formula (I) and chemically-sensitized with a short-chain xanthate of formula (II). R1-R6 = H, halogen, cyano, methyl, trifluoromethyl, methoxy, aryl or hetaryl or R1/R2, R2/R3, R4/R5 and/or R5/R6 combinations form an optionally substituted condensed benzo or naphtho ring system; R7 and R8 = alkyl, YSO3-alkylene, YO2C-alkylene, alkylene-SO2-NY-SO2-alkyl, alkylene-SO2-NY-CO-alkyl, alkylene-CO-NY-SO2-alkyl or alkylene-CO-NY-CO-alkyl, with the alkyl and alkylene groups being optionally substituted; Y = H or a negative charge; R9 = H, methyl or ethyl; G = a charge-balancing counterion; X and n = (i) S and 0, (ii) O and 3 or (iii) S and 3 for blue-, green- and red-sensitive emulsions respectively; R10 = up to 3C alkyl or alkylene; m = 1 or 2; M = a counterion; and o = a value appropriate for an uncharged compound.