Patent ID: 7081329

Claim:
A planographic printing plate precursor comprising: a support; and an image recording layer which has a two-layer structure including a first layer containing a binder polymer and a second layer containing a binder polymer, a polymerization initiator, a polymerizable compound, and an IR absorber, the first layer and the second layer having different curing properties, wherein: after being exposed with a laser beam, a developing rate of an unexposed portion of the image recording layer by an alkaline developer having a pH of 10 to 13.5 is 100 nm/sec or more, where the developing rate refers to a value obtained by dividing a film thickness (nm) of the image recording layer by an amount of time (sec) required to develop the image recording layer; and after being exposed with a laser beam, a permeation rate of the alkaline developer to an exposed portion of the image recording layer is 100 nF/sec or less, where the permeation rate refers to a value indicating a rate of change of electrostatic capacity (F) when the image recording layer is formed on a conductive support, and dipped in the developer; and wherein the binder polymer in the first layer contains a polymer having a repeating structural unit represented by the following general formula (I): wherein R 1 represents a hydrogen atom or a methyl group; R 2 represents an (n+1) valent substituted or unsubstituted hydrocarbon group having an alicyclic structure with 3 to 30 carbon atoms in which one or more carbon atoms of R 2 may be replaced by an oxygen atom or a nitrogen atom; A represents an oxygen atom or a NR 3 group in which R 3 represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms; and n represents an integer from 1 to 5.