| 摘要 |
PURPOSE:To impart high printing durability and, at the same time, to make a non-image part hard to be contaminated, by a method wherein aluminum hydrate is formed to at least one surface of an aluminum plate to which said blasting is applied and the surface thereof is subsequently treated with silicate before being subjected to anodic oxidation treatment. CONSTITUTION:Aluminum hydrate is formed to an aluminum plate having a roughened surface by steam treatment, the immersion treatment in water at 60-100 deg.C or the immersion treatment in a dilute alkali solution at 60-100 deg.C to enhance the effect of hydrophilicity imparting treatment due to silicate performed thereafter. After silicate treatment, anodic oxidation treatment is further applied to said aluminum plate to obtain a support for a planographic printing plate having a surface forming a strong close bonding strength with an image part. The silicate treatment is performed by forming a silicate layer by an immersion method using alkali metal silicate, for example, sodium silicate or alkaline earth metal silicate treatment. When the photosensitive layer of a PS plate (Pre-Sensitized Plate) is provided on the support for the planographic printing plate thus obtained, a photosensitive planographic printing plate can be obtained. |
