Patent ID: 6010835
Filing Date: 2000-01-04
Classification: G03C

Abstract:
A kit for photographic developing bath comprising three concentrates, (A), (B) and (C), wherein:concentrate (A) is an aqueous basic solution with pH higher than 8,concentrate (B) is an aqueous acid solution containing a paraphenylenediamine color developing agent, andconcentrate (C) is a homogeneous aqueous solution containing a compound with formula (I) and a compound with formula (II) ##STR2## in which said compounds (I) and (II) differ only in the groups X and Y; X is --COOH or --SO.sub.3 H and when X is --COOH, Y is --COOM, and when X is --SO.sub.3 H, Y is --SO.sub.3 M, where M is selected from among sodium, potassium, lithium or ammonium; n is 1 or 2; the redox potential of compounds (I) and (II) is higher than -700 mV; the total concentration (Ct) of compounds (I) and (II) in concentrate (C) is higher than the solubility (SI) of compound (I) in concentrate (C) and lower than the solubility (SII) of compound (II) in concentrate (C), and the pH is higher than pKa+Log((Ct-S(I))/S(I)).