| 摘要 |
PROBLEM TO BE SOLVED: To provide a negative type original plate of a planographic printing plate capable of plate-making directly by recording from digital data of a computer or the like using an IR emitting solid laser and a semiconductor laser, excellent in developability on a machine and excellent in printing resistance so as to give a large number of good prints even when heating is not carried out after exposure and to provide a planographic printing method for the printing plate. SOLUTION: The original plate has a water-soluble or water-dispersible photosensitive layer containing (A) an IR absorbent, (B) a radical polymerization initiator, (C) a radical polymerizable compound and (D) a binder which is preferably water-soluble and has a radical polymerizable functional group on the base and permits recording by irradiation with IR. |
