Dry silver photo-sensitive compositions, dyes for use therein and preparation of such dyes.

摘要

Dry silver photo-sensitive compositions comprising an intimate mixture of a substantially light-insensitive silver compound which upon reduction gives a visible change and sufficient of a silver halide to catalyse said reduction to give a visible change in those areas where the silver halide has been exposed to light and when the mixture is heated in the presence of a reducing agent, and as an acutance dye a compound of the general formula: <CHEM>