Patent ID: 7425400

Claim:
A planographic printing plate precursor, comprising: a substrate; a photosensitive layer comprising an IR absorber, a polymerization initiator, a polymerizable compound and a binder polymer; and a protective layer containing a UV absorber, disposed in this order, wherein the photosensitive layer exhibits reduction in solubility in an alkaline developing solution upon being exposed to light having a wavelength of 750 nm to 1400 nm; the photosensitive layer further comprises a compound containing at least one carboxylic group and having a weight-average molecular weight of 3000 or less; the compound containing at least one carboxylic group is one selected from the group consisting of a phthalic acid derivative, a trimellitic acid derivative, a pyromellitic acid derivative, a succinic acid derivative, a benzoic acid derivative and a glycine derivative; and the UV absorber is represented by the following Formula [1-a], [1-s], [1-c] or [1-d]: wherein in Formula [1-a], R 1a is an atomic group represented by —OX or —N(X)(Y), wherein X and Y each represent a hydrogen atom, alkyl group, cyanoalkyl group, carboxyalkyl group, sulfoalkyl group, hydroxylalkyl group, halogenated alkyl group or optionally substituted alkyl group, or a sodium or potassium salt thereof; R 2a and R 3a each represent a hydrogen atom, halogen atom, alkyl group, hydroxyl group, alkoxy group, alkylthio group, or the same group as the above-mentioned —OX group; Q represents a phenyl group, sulfoalkyl group, sulfoalkoxyalkyl group or sulfoalkylthioalkyl group, each of which is substituted with at least one halogen atom, carboxy group, sulfo group, sulfoalkyl group, or sodium or potassium salt thereof; L represents an optionally substituted methine group; R 4a represents an alkyl group, carboxy group, alkyloxycarbonyl group, or acyl-substituted or unsubstituted amino group; m is 1 or 2; and n is 0 or 1; in formula [1-b], R 1b , R 2b , R 3b , R 4b and R 5b each represent a hydrogen atom, halogen atom, alkyl group, hydroxyl group, alkoxy group, amino group, acylamino group, carboxyl group or sulfone group, or a sodium or potassium salt thereof; and R represents an alkyl group or carboxyl group; in formula [1-c], R 1c and R 2c each represent an alkyl group, substituted alkyl group, aryl group, alkoxycarbonyl group or carboxyl group; R 3c and R 4c each represent a sulfonic acid group, an alkyl or sulfonic acid group substituted with a carboxyl group, an aryl group substituted with a carboxyl group or sulfonic acid group, or a sodium or potassium salt thereof; L represents a substituted or unsubstituted methine chain; M represents sodium, potassium or a hydrogen atom; and 1 is 0 or 1; in formula [1-d], R 1d , R 2d , R 3d and R 4d each represent an alkyl group, hydroxyalkyl group, cyano group, alkylcyano group, alkoxy group or sulfoalkyl group; and R 5d and R 6d each represent a sulfonic acid group and alkylsulfonic acid group.