| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a positive lithographic printing plate 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 containing: a water-insoluble and alkali-soluble resin having a urea bond in the polymer chain; a development inhibitor; and an IR absorbent, and exhibiting enhanced solubility in an aqueous alkaline solution by light exposure. The recording layer may have a mono-layer construction or a multi-layer construction. If the recording layer has a multi-layer construction, a layer containing a water-insoluble and alkali-soluble resin having a urea bond in the polymer main chain is necessary to be used as a lower layer, and a layer containing a water-insoluble and alkali-soluble resin and a development inhibitor and exhibiting enhanced solubility in an aqueous alkaline solution by light exposure is necessary to be used as an upper layer , and at least either the lower layer or the upper layer contains an IR absorbent. <P>COPYRIGHT: (C)2004,JPO |
