ORIGINAL PLATE FOR PLANOGRAPHIC PRINTING PLATE AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an original plate for a planographic printing plate which does not cause the problem that pollutants in the air are adsorbed and stain- proofing property deteriorates with age when allowed to stand in a room for several hours to several days and has high sensitivity and to provide a method for producing the original plate. SOLUTION: The original plate has a photosensitive layer containing a high molecular compound whose alkali solubility is varied by heat and a material which absorbs light and generates heat on a base with a coating layer containing an inorganic fluorine compound and a phosphorus compound on the surface of an aluminum-base metallic sheet. The original plate is produced by anodically oxidizing the metallic sheet, treating it with an aqueous solution containing the inorganic fluorine compound and the phosphorus compound and forming the photosensitive layer on the treated metallic sheet.