| 摘要 |
PURPOSE:To directly make a printing plate through the electrophotographic process and to enhance printing resistance by forming a layer composed essentially of a specified azo pigment and an alkali-soluble resin on a conductive substrate. CONSTITUTION:A conductive substrate is coated with a layer composed essentially of an alkali-soluble resin and an azo pigment represented by the formula shown here in which A is a coupler residue. As the coupler of the formula, compds. having a phenolic OH group, such as phenols and naphthols, and an aromatic compds. having an amino group, etc. are used. As said alkali-soluble resin, a resin which is made soluble in an aq. or alcoholic solvent by addition of alkali, and, e.g. a styrene-maleic anhydride copolymer, a styrene-methacrylic acid-methacrylate copolymer, etc., are used, and for this resin, film forming property, electric characteristics, strength of adhesion to a substrate, and especially solubility characteristics, etc. are important. The printing plate of such a constitution is good in sensitivity and it can be directly manufactured by using various kinds of light sources, such as laser, and the obtained printing plate has a high printing resistance. |
