New 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

photographic silver halide material comprises a shifted dye compound capable of releasing a dye moiety, characterized in that said compound corresponds in reduced state to general formula (1) and in oxidized state to general formula (2) :wherein :A' represents a hydroquinonyl group including a substituted hydroquinonyl group, or such group forming part of a fused ring system,A² represents a quinonyl group including a substituted quinonyl group, or such group forming part of a fused ring system,L represents a bivalent group which undergoes a cleavage under hydrolytic alkaline conditions when the compound is in reduced state corresponding to formula (1),P represents an organic dye moiety incorporating an azo chromophoric group -N=N- linked through a conjugated bond system to an electron-withdrawing group being a monoester oxalyl groupwherein R represents an organic group, that can be introduced by esterification of a carboxylic acid group, said monoester oxalyl group being removable by hydrolysis resulting in a residual auxochromic hydroxyl (-OH) group.