FINISHING LIQUID FOR PLANOGRAPHIC PRINTING PLATE AND PLATE MAKING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a finishing liquid for planographic printing plates by utilizing a silver complex salt diffusion transfer process using an aluminum plate having excellent ink staining resistance as a base and more particularly to provide the finishing liquid capable of preventing fingerprint-like staining without degrading the ink receptability of silver image parts and a plate making method using this finishing liquid. SOLUTION: This finishing liquid is the finishing liquid for the planographic printing plates utilizing the silver complex salt diffusion transfer process using the aluminum plate as the base and contains >=0.2 mol/liteer nitric acid ions. This plate making method consists in exposing the planographic printing plate which has physical development nuclei between the aluminum base and silver halide emulsion layers and is formed by applying the silver complex salt diffusion transfer process to exposure, then subjecting the material to at least development processing, washing processing and finishing processing. At this time, the finishing liquid contg. >=0.2 mol/liter nitric acid ions is used for the finishing processing.