| 摘要 |
PROBLEM TO BE SOLVED: To provide an original plate for a lithographic printing plate which has a large difference between solubility resistance to a developing solution for image portions and solubility for non-image portions, and exhibits a high printing durability and good chemical resistance for image portions and good solubility for non-image portions.SOLUTION: The original plate for a lithographic printing plate has at least two recording layers including an alkali-soluble resin, upon a surface hydrophilic support body. At least one layer is a positive recording layer containing an infrared absorbent. The recording layer closest to the support body, among the at least two recording layers, contains: (A) an alkali-soluble polyurethane having an acid group; and (B) a (meth)acrylic resin having a repeating unit selected from structural units represented by general formulas (I) and (II). In the general formulas (I) and (II): Arand Areach represent an aromatic group, and at least one of them is a heteroaromatic group; and a and b each represent 0 or 1. |
