METHOD AND APPARATUS FOR PRODUCING PLANOGRAPHIC PRINTING ORIGINAL PLATE

摘要

PROBLEM TO BE SOLVED: To produce a planographic printing original plate capable of suppressing the coloration of an exposed part when a planographic printing plate is manufactured by removing a thin silver film by heat-mode laser exposure. SOLUTION: A silver halide emulsion is applied on a substrate and developed with a diffusion transfer developing solution to form a thin silver film and subsequent processing is carried out with a processing solution having 0 to <0.1 ppm chlorine ion concentration to produce the objective planographic printing original plate used for manufacturing a planographic printing plate by removing the thin silver film by heat-mode laser exposure.