| 摘要 |
PROBLEM TO BE SOLVED: To obtain a printing master plate having good image reproducibility and good printing durability by incorporating a compd. which can decompose by the effect of irradiation of laser light, a thermosetting compd. and a polyester into a thermosensitive layer. SOLUTION: This direct drawing type lithographic printing master plate has a thermosensitive layer containing a compd. which can decompose by the effect of laser irradiation and a thermosetting compd., and an ink repelling layer in this order on a substrate. The thermosensitive layer contains a polyester. As for the compd. which can decompose by the effect of laser irradiation, polymethine-based near IR absorbing dyes and phthalocyanine-based near IR absorbing dyes are preferable. As for the thermosetting compd., a novolac resin or the like obtd. by condensation of phenols and formaldehyde can be used. As for the polyester, a polyester obtd. by polymn. condensation of polyhydric alcohol and polyvalent carboxylic acid, or a polyester obtd. by polymn. of polyhydric alcohol and polyvalent carboxylic acid anhydride can be used. |
