Diffusion transfer photographic system utilizing substituted phenylmercaptoazoles

Claim 1

A photographic product for use in forming a diffusion transfer photographic image comprising a photosensitive element comprising a support carrying at least one silver halide emulsion layer having associated therewith an image dye-providing material, a second sheet-like element positioned in superposed or superposable relationship with said photosensitive element, an image receiving layer positioned in one of said elements, means for lowering the pH of an aqueous alkaline processing composition positioned in one of said elements, a rupturable container releasably holding an aqueous alkaline processing composition adapted, when distributed between a pair of predetermined layers carried by said photosensitive element and said second element, to develop said silver halide emulsion and provide a diffusion transfer image on said image receiving layer, said product including at least one compound represented by the formula ##STR24## wherein X represents the nonmetallic atoms necessary to form a nucleus which completes a 5- or 6-membered heterocyclic moiety on said structure, R is H, an alkali metal or an group which is cleavable in said aqueous alkaline processing composition and R 1 is either a group which has a pKa of from about 7 to about 14 which is ionizable to an anion and wherein the silver salt of the mercaptan resulting from cleavage or ionization of --SR is more soluble in said aqueous alkaline processing composition in the pH range within which R 1 is ionized to an anion than said silver salt is below that pH range, or a precursor, wherein said processing composition initially has a pH substantially equal to or above the pKa of R 1 and said means for lowering the pH of an aqueous alkaline processing composition is adapted to lower the pH of said aqueous alkaline processing composition below the pKa of R 1 .