| 摘要 |
PROBLEM TO BE SOLVED: To provide a positive original plate of a planographic printing plate for an IR laser for direct plate making excellent in latitude and scuffing resis tance in image formation by development and capable of forming an image of superior image quality. SOLUTION: The original plate is obtained by disposing a positive recording layer containing (A) a water-insoluble and alkali-soluble resin, (B) an IR absorber and (C) an organic quaternary ammonium salt and having solubility in an alkaline aqueous solution increased by exposure with infrared laser light on a base. A compound having at least one of aryl and carbonyl groups in its molecule is preferably used as (C) the organic quaternary ammonium salt. |
