| 摘要 |
PURPOSE:To obtain a PS printing plate capable of providing a planographic printing plate excellent in durability in printing and free from contamination of a non-image part and ground contamination, by a method wherein an aluminum plate subjected to sanding and anodic oxidation is exposed to an atmosphere of a specified temperature and a specified steam pressure, and then a photosensitive layer is provided. CONSTITUTION:The surface of an aluminum plate which is a plate form body of pure aluminum or an aluminum alloy having a thickness of about 0.1-0.5mm. is roughened by a mechanical or electrochemical method, and after a sanding treatment, an anodic oxide film having a specific weight of 0.1-10g/m<2> is provided by using an electrolyte such as sulfuric acid or phosphoric acid. The aluminum plate thus subjected to anodic oxidation is exposed to an atmosphere of a temperature of 50-300 deg.C and the steam pressure of 90 Torr for 1sec-30min, and is treated with an aqueous solution of sodium silicate or the like, as required, and a hydrophilic undercoat layer is provided. Thereafter, a photosensitive composition such as a composition comprised of a diazo resin or a composition comprised of o-quinone diazide compound is applied thereon to produce a photosensitive layer. |
