Patent ID: 7485409

Claim:
A planographic printing plate precursor comprising: a support; and a positive recording layer formed on the support, the positive recording layer including: (A) a polymer having a structural unit represented by the following general formula (1), (B) a photo-thermal converting agent, and (C) an amino compound having a methylol group or an alkoxymethyl group, wherein the solubility of the positive recording layer in an alkaline developer is improved by exposure to light or by heating: wherein in general formula (1), R 1 represents an alkyl group or a cyclic group, x represents 0 or 1, and A in general formula (1) is selected from the group consisting of an alkylene group, a connection group represented by the following general formula (2), and a connection group represented by the following general formula (3): wherein in general formula (2) and general formula (3), x each independently represents 0 or 1, and, in general formula (3), R 3 and R 4 each independently represents a hydrogen atom or an alkyl group.