| 摘要 |
PROBLEM TO BE SOLVED: To provide a planographic printing original plate, to which direct recording is possible from digital data of a computer or the like by using a heat-mode laser without requiring a heat treatment after an imagewise exposure and which is excellent in sensitivity during recording and in printing durability. SOLUTION: The original plate has a photosensitive layer which contains (A) a photo-thermal converting agent, (B) a compound having polymerizable unsaturated groups and (C) a photo- or thermal polymerization initiator having polymerizable unsaturated groups and to which recording is possible with a heat-mode laser, on a supporting body. The photo- or thermal polymerization initiator (C) having polymerizable unsaturated groups means a well-known polymerization initiator which produces radicals by the energy of light or heat, and it is preferably a compound having polymerizable unsaturated groups of cationic polymerizable groups, anionic polymerizable groups, radial polymerizable groups or the like in the molecule of an onium salt compound. The exposure wavelength of the heat-mode laser used for recording is preferably in the range from 760 to 1,200 nm. |
