PRODUCTION OF PLANOGRAPHIC PRINTING ORIGINAL PLATE

摘要

PROBLEM TO BE SOLVED: To produce a planographie printing original plate excellent in suitability to ablation, excellent also in ink receptivity and ensuring stable printing performance in the production of a planographic printing original plate used for manufacturing a planographic printing plate by removing a thin silver film by heat-mode laser exposure. SOLUTION: A physical developing nucleus layer is disposed on a web-shaped substrate having a hydrophilic surface or provided with a hydrophilic layer, or a substrate having a surface active to physical development is selected. The top of the substrate is coated with a silver halide emulsion layer and this emulsion layer is processed with a diffusion transfer developing solution containing an amine compound and a compound which makes a silver image lipophilic to form a thin silver film on the substrate. The objective planographic printing original plate is thus produced.