| 摘要 |
PROBLEM TO BE SOLVED: To produce a substrate for a planographic printing plate which prevents the occurrence of a residual film after development in the case of a negative type image forming layer comprising acrylic resin or urethane resin and diazo resin or a positive type image forming layer comprising cresol-novolak resin and a diazo compound and ensures higher sensitivity due to high adhesive strength of a photosensitive layer to the substrate and retains thin lines and highlight dots even after printing repeated many times in the case of coating a photopolymer-base negative type photopolymerizable image forming layer. SOLUTION: In this substrate for a planographic printing plate having an anodic oxide film of aluminum on aluminum or its alloy and an inorganic oxide layer other than the anodic oxide film of aluminum on the anodic oxide film, a multiple oxide layer comprising an inorganic material as the principal component of the inorganic oxide layer and aluminum is allowed to exist between the anodic oxide film and the inorganic oxide layer. |
