METHOD OF MANUFACTURING LITHOGRAPHIC PRINTING PLATE MATERIAL, STACK OF LITHOGRAPHIC PRINTING PLATE MATERIAL AND SLIP SHEET, AND LITHOGRAPHIC PRINTING PLATE MATERIAL

PROBLEM TO BE SOLVED: To provide a method of manufacturing a lithographic printing plate material by which a positive lithographic printing plate material having high sensitivity and excellent in scratch resistance and storage stability is yielded. SOLUTION: The method of manufacturing a lithographic printing plate material includes applying a coating liquid on a support, drying it to form an image forming layer, laying a slip sheet, cutting, stacking the resulting lithographic printing plate material on which the slip sheet has been laid, and heat treating, wherein the image forming layer is a positive image forming layer containing an alkali-soluble resin and a photothermal conversion agent, the coating liquid contains an organic solvent having a boiling point of 120-300°C, a water content A (g/m2) of the slip sheet in the stacking step is 1-7.0 (g/m2), and, when stacking, a ratio between a residual amount B (g/m2) of the organic solvent having a boiling point of 120-300°C in the image forming layer and the water content A (g/m2) of the slip sheet (A/B) is 10-200. COPYRIGHT: (C)2010,JPO&INPIT