| 摘要 |
PURPOSE:To facilitate and ensure vacuum adhesion in interposing an original image between a pressing glass and a silicone rubber layer, by roughening the uppermost silicone rubber layer surface of a lithographic original plate nonrequiring damping water. CONSTITUTION:A photosensitive layer is provided on a substrate, such as an aluminum plate or a plastic sheet, and a silicone rubber layer is formed on this layer, or a photosensitive silicone rubber layer is provided on the substrate to form a damping water nonrequiring lithographic original plate. On the surface of the uppermost silicone rubber layer of this plate a fluid formed by dissolving or dispersing SiO2, TiO2, glass particles, and polymer particles, such as polymethyl methacrylate or phenol resin, and, when needed, a binder, such as gelatin, cellulosic resin, or polyvinyl alcohol is spray-dried. A particle diameter of said powder is selected so as to form a roughness of 50mmu-50mu height and 0.01-20mm. mean peak interval, thus permitting vacuum adhesion to be facilitated. The roughness is perfectly removed by development, and the original image and the printing plate are not unfavorably affected. |
