DYE RELEASING COMPOUNDS AND THEIR USE IN PHOTOGRAPHIC SILVER HALIDE COLOUR MATERIALS FOR THE PRODUCTION OF COLOUR IMAGES BY A DYE DIFFUSION TRANSFER PROCESS

摘要

AbstractNew dye releasing compounds and their use in photographic silverhalide colour materials for the production of colour images by a dyediffusion transfer process.A photographic silver halide material comprises a shifted dyecompound capable of releasing a dye moiety, characterized in thatsaid compound corresponds in reduced state to general formula (1) andin oxidized state to general formula (2) :A1 - L - P (1)A2 - L - P (2)wherein :A1 represents a hydroquinonyl group including a substitutedhydroquinonyl group, or such group forming part of a fused ringsystem,A2 represents a quinonyl group including a substituted quinonylgroup, or such group forming part of a fused ring system,L represents a bivalent group which undergoes a cleavage underhydrolytic alkaline conditions when the compound is in reducedstate corresponding to formula (1),P represents an organic dye moiety incorporating an azochromophoric group -N=N- linked through a conjugated bond systemto an electron-withdrawing group being a monoester oxalyl group, wherein R represents an organic group, that can beintroduced by esterification of a carboxylic acid group, saidmonoester oxalyl group being removable by hydrolysis resultingin a residual auxochromic hydroxyl (-OH) group.