| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for making lithographic printing plate reduced in occurrence of sediment in a development tank and excellent in stability along with the lapse of time, and a lithographic printing plate made by the method for making a lithographic printing plate.SOLUTION: The method for making a lithographic printing plate includes an exposure process and a development process sequentially in this order. In the exposure process, image exposure is carried out in an infrared laser positive lithographic printing original plate including a positive recording layer, which includes, on a support, a copolymer (component A) comprising a (meth)acrylonitrile-derived constitutional unit and a styrene-derived constitutional unit, a water-insoluble and alkali-soluble resin (component B), and an infrared absorbing agent (component C), and improves its solubility to an alkali aqueous solution by exposure/heating. In the development process, development is carried out by using an alkali aqueous solution containing a nonionic surfactant and having a pH of 8.5-10.8. |
