| 摘要 |
PROBLEM TO BE SOLVED: To provide a positive-working lithographic printing plate precursor for infrared laser having excellent development latitude, dissolution discrimination, and high printing durability and having little post-exposure degradation in developability over time and good in developability change.SOLUTION: The positive-working lithographic printing plate precursor for infrared laser includes, layered sequentially above a support, a lower layer comprising an alkali-soluble group-containing graft copolymer and an upper layer whose solubility in an aqueous alkali solution increases by exposure, wherein the lower layer and/or the upper layer includes an infrared absorbing agent and the graft copolymer in the lower layer is a polyurethane having as a graft chain an ethylenically unsaturated monomer-derived constitutional unit. |
