PRODUCTION OF PLANOGRAPHIC PRINTING ORIGINAL PLATE

摘要

PROBLEM TO BE SOLVED: To mass-produce a planographic printing original plate having stable quality used for manufacturing a planographic printing plate by removing a thin silver film by heat-mode laser beam exposure. SOLUTION: A physical developing nucleus layer is disposed on a web-shaped substrate having a hydrophilic surface or provided with a hydrophilic layer. The top of the substrate or a substrate having a surface active to physical development is coated with a silver halide emulsion layer, a diffusion transfer developer is supplied to deposit physically developed silver and a stabilizing solution is supplied to carry out neutralization. A thin silver film is formed on the substrate by washing off the emulsion layer.