| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a planographic printing original plate which permits the writing by means of infrared laser, is allowed to suppress the occurrence of both of image defects and image irregularities in development, can form a uniform and high quality picture over the whole surface of a plate and, in particular, has excellent plate wear resistance on a dot picture region, and to provide a platemaking method suitable for the planographic printing original plate capable for forming the high quality picture. <P>SOLUTION: The planographic printing original plate has a photosensitive layer comprising a binder polymer with repeated units expressed by a general formula (I), an infrared ray absorber, a polymerization initiator and a polymerizable compound, and a protective layer on a substrate. In the general formula (I), R<SP>1</SP>represents hydrogen atom or methyl group and R<SP>2</SP>represents a binding group. (A) represents oxygen atom or -NR<SP>3</SP>-, R<SP>3</SP>represents hydrogen atom or monovalent hydrocarbon group of the number of carbon 1 to 10 and (n) represents an integer of 1 to 5. The planographic printing original plate is preferably exposed by using the light of wavelength 750nm to 1400nm and, thereafter, is subjected to development process on the conditions of conveyance speed of plate material ≥1.25m/min without substantial heating treatment. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
