Patent ID: 8722310
Filing Date: 2014-05-13
Classification: B41C,G03F

Abstract:
1. A lithographic printing plate precursor comprising, in the following order: a support; an image-recording layer which is capable of forming an image by removing an unexposed area by an automatic development processor in the presence of a developer having pH of from 2 to 14 after exposure and contains (A) a sensitizing dye, (B) a polymerization initiator, (C) a polymerizable compound and (D) an organic polymer having a carboxylic acid or salt thereof; and a protective layer, wherein the protective layer contains (E) a hydrophilic polymer which has a repeating unit represented by the following formula (1) and a repeating unit represented by the following formula (2) and a sum of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) is at least 95% by mole based on total repeating units constituting the polymer: wherein, in the formulae (1) and (2), R 1 and R 4 each independently represents a hydrogen atom or a methyl group, R 2 and R 3 , which may be the same or different, each represents a hydrogen atom, a methyl group or an ethyl group, and R 5 represents an alkyl group having from 2 to 10 carbon atoms or a substituent represented by the following formula (3), and in the formula (3), L represents an alkylene group having from 2 to 6 carbon atoms, R 6 represents an alkyl group having from 4 to 8 carbon atoms, and n is an average addition molar number of polyether and represents a number of from 2 to 4, wherein the polymer (E) further has a repeating unit represented by the following formula (4) in an amount of from 0.3 to 5.0% by mole based on total repeating units constituting the polymer: wherein, in the formula (4), R 7 represents a hydrogen atom or a methyl group, X represents a single bond, a divalent connecting chain selected from structures of Structural Group (5) or a divalent connecting chain formed by a combination of two or more structures of Structural Group (5), and Y represents at least one substituent selected from a carboxylic acid group, a carboxylate group, a sulfonic acid group, a sulfonate group, a phosphoric acid group, a phosphate group, a phosphonic acid group, a phosphonate group, a hydroxy group, a carbobetaine group, a sulfobetaine group and an ammonium group.