Patent ID: 7407735

Claim:
A light sensitive planographic printing plate precursor comprising a hydrophilic support and provided thereon, a photopolymerizable light sensitive layer containing a first compound represented by the following formula (1) or (2) and a sensitizing dye having an absorption maximum in the wavelength regions of from 350 to 450 nm, wherein Q 1 represents or —S—; R 4 represents an alkyl group, a hydroxy alkyl group, or an aryl group; R 1 and R 2 independently represent a hydrogen atom, an alkyl group, or an alkoxyalkyl group; R 3 represents a hydrogen atom, a methyl group, or an ethyl group; x 1 represents a divalent linkage group having a carbon atom number of from 2 to 12; x 2 represents a divalent linkage group, a trivalent linkage group, a tetravalent linkage group, or in which Z represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a halogen atom, an alkoxy group, or a heterocyclic group, p is an integer of from 1 to 4, and q is an integer of from 1 to 3; D 1 and D 2 independently represent a divalent linkage group having a carbon atom number of from 1 to 5; E represents an alkylene group having a carbon atom number of from 2 to 12 or an arylene group having a carbon atom number of from 6 to 12; a is an integer of from 1 to 4; b is 0 or 1; c is an integer of from 1 to 3; m is an integer of from 2 to 4; and n is an integer of from 1 to m, provided that plural groups having the same definition may be the same or different, wherein Q 2 represents R 8 represents an alkyl group, a hydroxy alkyl group, or an aryl group; R 5 and R 6 independently represent a hydrogen atom, an alkyl group, or an alkoxyalkyl group; and R 7 represents a hydrogen atom, a methyl group, or an ethyl group; D 3 and D 4 independently represent a divalent saturated hydrocarbon group having a carbon atom number of from 1 to 5; F represents an alkylene group having a carbon atom number of from 2 to 12 or an arylene group having a carbon atom number of from 6 to 12; d and e independently represent an integer of from 1 to 4; g is an integer of from 2 to 4; and f is an integer of from 1 to g, provided that plural groups having the same definition may be the same or different, and wherein the sensitizing dye is selected from the group consisting of compounds represented by the following formulae (5), and (8), wherein R 14 represents a hydrogen atom, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, an aryl group or a heterocyclic group; R 15 and R 16 represent a substituent capable of combining with each other to form a ring; and X 11 and X 12 independently represent —CR 17 R 18 —, —O—, —S—, or —NR 19 —, in which R 17 , R 18 , and R 19 independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, wherein X 1 , X 2 , X 3 , X 4 and X 5 independently represent a substituent; and Z represents an aryl group or an aromatic heterocyclic group.