LITHOGRAPHIC PRINTING PLATE MATERIAL AND METHOD FOR PREPARING THE SAME

PROBLEM TO BE SOLVED: To provide a positive lithographic printing plate material having high sensitivity and excellent also in scratch resistance. SOLUTION: The lithographic printing plate material is formed by applying and drying, on a hydrophilic support, a coating liquid for a photosensitive layer containing (A) a resin having a phenolic hydroxyl group, (B) an alkali-soluble acrylic resin, (C) a dye having a function to absorb near-infrared light of 750-1,100 nm and convert it to heat, (D) at least one selected from acid-decomposable compounds represented by formula: R3-O-(R1)C(R2)-O-R4and acid-decomposable compounds represented by general formula (ADC-2), (E) a solvent in which the resin (B) exhibits solubility of ≥30 (g/100 g of the solvent) at 25°C, and (F) a solvent in which the resin (B) exhibits solubility of ≤20 (g/100 g of the solvent) at 25°C and which has a boiling point (T2) higher than a boiling point (T1) of the solvent (E) by ≥20°C, wherein the content of the solvent (E) is 5-40 mass% of the total amount of the solvents. COPYRIGHT: (C)2009,JPO&INPIT