PLANOGRAPHIC PRINTING ORIGINAL PLATE AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a laser plate making type planographic printing original plate excellent in printing durability and not generating scumming and tinting; and a method for manufacturing the same. SOLUTION: A support is formed by applying surface roughening treatment to at least one surface of an aluminum plate. In the surface roughening treatment, mechanical surface roughening treatment for rubbing the aluminum plate by a rotary brush while supplying abrasive particles with a mean particle size of 5-70 μm and a SiO2 content of 60 wt.% or more is applied to the aluminum plate and etching treatment is subsequently applied to the aluminum plate and electrolytic surface roughening treatment is applied to the aluminum plate to electrolytically treat the aluminum plate in an acidic electrolyte to obtain the support for a planographic printing plate. The planographic original plate is equipped with this support and the positive type infrared laser photosensitive layer laminated on the roughened surface formed by the surface roughening treatment of the support.