Patent ID: 7468234

Claim:
A planographic printing plate precursor, comprising: a support; and a photosensitive layer provided on the support and containing a polymer having the structural unit represented by the following Formula (1) and an acid coloring colorant represented by the following Formula (2), wherein, in Formula (1) above, X represents a bivalent connected group; R 1 represents an alkyl or aryl group; and x is 0 or 1, and in Formula (2) above, rings A, B, and C each independently represent a mono- to tri-nuclear aromatic hydrocarbon group or a heterocyclic aromatic group; at least one of the rings B and C is substituted with at least one substituent group selected from the group consisting of amino, alkoxy, aryloxy, alkylthio, and arylthio groups; rings B and C may bind to each other via a binding group; W 1 represents a carbonyl or thiocarbonyl group, or —C(R 25 )═N—, wherein R 25 represents a hydrogen atom or a hydrocarbon group, and Q 1 represents an oxygen or sulfur atom, or an imino group; R 21 to R 24 each independently represent a hydrogen atom or a hydrocarbon group; and m and n are each independently 0 or 1.