| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative type original plate of a planographic printing plate capable of direct recording from digital data of a computer or the like with an IR laser, having high sensitivity and good curability of image area and excellent in solvent resistance and printing durability. SOLUTION: The original plate has a photosensitive layer containing (A) an IR absorbent, (B) a thermal radical generating agent, (C) a polymer having a radical reactive group and (D) a compound having a thiol group on the substrate. The photosensitive layer may further contain (E) a polymerizable monomer. A compound having >=2 SH groups is preferably used as the thiol compound. |
