| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an on-press developing lithographic printing plate original plate image exposure by a laser, having a good on-press developing property despite of a passage of time, while maintaining a sufficient plate life and ink acceptability. <P>SOLUTION: A lithographic printing plate original plate comprises in the following order; a support; an image-recording layer containing (A) an infrared absorbing agent, (B) a polymerization initiator and (C) a polymerizable compound; and a protective layer; and, if necessary, an intermediate layer between the support and the image-recording layer. An unexposed area of the image-recording layer can be removed with at least one of printing ink and dampening water on a printing machine, and the lithographic printing plate original plate contains a compound represented by formula (I): wherein, R<SB>1</SB>represents such as an alkyl group, R<SB>2</SB>and R<SB>3</SB>each represent such as a methyl group, L represents such as a connecting group, and n represents an integer of from 0 to 11. <P>COPYRIGHT: (C)2011,JPO&INPIT |
