PRINTING PLATE MATERIAL AND PROCESS FOR PRODUCING THE SAME

摘要

A printing plate material which can form uneven patterns on its surface even with a low laser energy and enables printing while preventing scumming of a print is produced by forming on a support a photosensitive layer containing nitrocellulose, a black coloring agent, such as carbon black, and an organic binder and having either (1) a surface roughness R max of 2.0 mu m or less or (2) wettability index of 36 dyn/cm or less. The nitrocellulose has a nitrogen content of 11-12.5 % and a solution viscosity of about 1-1/8 sec. The organic binder contains a polyester resin such as a solvent-soluble, non crystalline and linear oil-free aromatic polyester. The nitrocellulose and the coloring agent are used in amounts of, respectively, 5-300 parts by weight and 0.5-50 parts by weight per 100 parts by weight of the organic binder. The photosensitive layer may contain a cross-linking agent such as a melamine resin and a water repellent such as a silicone or fluorine compound. An example of the usable support is a polyethylene terephthalate film having a mean density of less than 1.39.