Patent ID: 8221957

Claim:
A planographic printing plate precursor comprising: a hydrophilic support; and an image recording layer that is provided on the support, the image recording layer comprising: an infrared ray absorbing agent (A); a polymerization initiator (B); a polymerizable monomer (C); and a polymer compound (D) having an alkyleneoxy group in its molecule and having, in a side chain thereof, at least one selected from a group represented by the following Formula (1) and a group represented by the following Formula (2): wherein, in Formula (1), R 1 to R 8 each independently represent a hydrogen atom or a monovalent substituent; X 1 and Y 1 each independently represent a single bond or a divalent linking group: and in Formula (2), R 9 to R 17 each independently represent a hydrogen atom or a monovalent substituent: A and B each independently represent a hydrogen atom or a monovalent substituent, provided that at least one of A and B is a hydroxyl group; and X 2 and Y 2 each independently represent a single bond or a divalent linking group: wherein the alkyleneoxy group is represented by the following Formula (3): wherein R 18 represents a hydrogen atom or a methyl j is an integer of 1 or 2; and k is an integer of 1 to 15: when k is an integer of 2 to 9, each of the R 18 among the plural R 18 s may be the same or different, and each of the integers respectively denoted by j may be the same or different; wherein the alkyleneoxy group represented by Formula (3) is included in a side chain of the polymer compound (D); and wherein the side chain including the alkyleneoxy group represented by Formula (3) is represented by the following Formula (4): wherein R 18 represents a hydrogen atom or a methyl group; R 19 represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent: j is an integer of 1 or 2; k is an integer of 1 to 15; when k is an integer of 2 to 9, each of the R 18 among the plural R 18 s may be the same or different, and each of the integers respectively denoted by j may be the same or different; and Z represents a single bond or a linking group connected with a main-chain skeleton of the polymer compound (D).