| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a positive lithographic printing original plate in which direct platemaking by scanning exposure based on digital signals can be carried out and which is excellent in printing durability and chemical resistance. <P>SOLUTION: The plate has a recording layer on a support, the recording layer which contains a water-insoluble and alkali-soluble resin containing ≥40 mol% of acrylonitrile as the copolymer component, a development restrainer and an IR absorbent and which increases the solubility with an alkali aqueous solution by exposure. The recording layer may have a single layer structure or a multilayer structure. When the recording layer has a multilayer structure, it is necessary that: the lower layer contains a water-insoluble and alkali-soluble resin having ≥40 mol% of acrylonitrile as the copolymer component; the upper layer contains a water-insoluble and alkali-soluble resin and a development restrainer and increases the solubility with an alkali aqueous solution by exposure; and at least one of the lower layer and the upper layer contains an IR absorbent. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
