Process for reducing sludge in diffusion transfer printing plates.

摘要

A method of making a lithographic printing plate comprises: (a) imagewise exposing a unitary light-sensitive material which has a support, at least one negative-working Ag halide layer and a surface physical development nucleating layer; an electron-transfer agent and a developer is present in one or more layers; and (b) processing the plate in a diffusion-transfer activator soln., pref. spiked and contg. a polyhydroxybenzene or aminophenol developer. The novelty is that the activator contains, at least 0.0148 M concn. of aminocarboxylic acid complexing agent, pref. EDTA or a salt thereof.