| 摘要 |
PURPOSE:To realize the title composition capable of giving lithographic plate having large plate wear and having broad reasonable processing condition by selecting a polymer having an active methylene group from a large number of the polymers, and by combining the selected polymer with a photosensitive material which acts to positive type. CONSTITUTION:The titled composition comprises the polymer having the active methylene group and the sensitive compd. which acts to the positive type or its mixture. The polymer having the active methylene group is not specified in case that said polymer contains the active methylene group, but, is preferably the polymer which has PKa of 4-11, and further preferably, has the methylene groups of 5-9 in a molecular structure and preferably, is insoluble to water and is soluble to an alkaline aqueous solution. The polymer is preferably the polymer having the active methylene group which directly bonds to at least >=1 groups selected from a carbonyl or a sulfonyl group in the molecular structure, and is insoluble to water and is soluble to the aqueous alkaline solution. |
