| 摘要 |
PURPOSE:To enhance the water resistance and printability of a lithographic original plate by providing a modified polyvinyl alcohol layer containing silicon on a supporter. CONSTITUTION:A modified polyvinyl alcohol containing silicon is obtained by a method in which silicon is introduced into a modified polyvinyl acetate with carboxylic or hydroxyl group or a polyvinyl alcohol by using a silylizing agent or subjecting a copolymer of vinyl ester and an olefinic unsaturated monomer containing silicon to saponification. A pigment particle of zinc oxide, cadmium sulfide, titanium oxide, etc., having a photo-conductive layer, is dispersed into the modified polyvinyl alcohol aqueous solution, and the dispersion is laminated on a supporter to obtain an original plate. The original plate is subjected to desensitization treatment in order to keep it in lipophilic state. Thus, the water resistance is raised because oil ink is adhered only to lipophilic sections. |
