| 摘要 |
PURPOSE:To provide a printing original plate having high sensitivity and high printing resistance by providing an electrophotographic sensitive layer consisting of two layers: an electric charge generating layer contg. a specific azo pigment and an electric charge transfer layer contg. an electric charge transfer material and alkali soluble resin on a conductive base. CONSTITUTION:The basic constitution of the printing original plate for electrophotographic engraving consists of the electrophotographic sensitive layer 2 formed by laminating the charge generating layer 3 and further the charge transfer layer 4 on the conductive base 1. The reverse lamination of the layer 3 and the layer 4, i.e., the latter on the former, is also possible. The electrophotographic sensitive layer (the charge generating layer and charge transfer layer) in the non-image part which is not masked by a toner image is dissolved away and the hydrophilic surface of the conductive base is exposed so that the image part coated with the lipophilic toner remains on the printing plate obtd. by forming the toner image on the original plate when said printing plate is immersed into an alkaline eluting soln. Thus oil ink sticks only on the image part in ordinary lithographic printing and the good printed matter having no ground stains is obtd. |
