PHOTOSENSITIVE PLANOGRAPHIC PRINTING PLATE HAVING EXCELLENT PRINTING RESISTANCE

摘要

PURPOSE:To obtain a photosensitive planographic printing plate which has excellent printing resistance and substantially obviates scumming by providing a photosensitive layer contg. a quinone diazide compd. and the vinyl polymer having phenolic hydroxyl group on an aluminum sheet obtd. after the surface is treated by the specific stage. CONSTITUTION:After sand grains are formed by a mechanical surface roughening method on the surface of the aluminum sheet, the sand grains are further formed electrochemically in an electrolyte consisting of hydrochloric acid, nitric acid or the combination thereof on the surface and the surface is anodized in an electrolyte of acid such as phosphoric acid, sulfuric acid or oxalic acid. The photosensitive layer consisting of the photosensitive compsn. contg. the quinone diazide compd. and the vinyl polymer having the phenolic hydroxyl group is provided on the aluminum sheet treated in such a manner. The photosensitive planographic printing plate which substantially obviates the scanning in UV printing and has the excellent printing resistance is thereby obtd.