Patent ID: 8714088

Claim:
A lithographic printing plate precursor comprising: an image-recording layer; and a protective layer comprising a stratiform compound, wherein the protective layer comprises a polymer containing, as a repeating unit, a structural unit having an ammonium structure, wherein the structural unit having an ammonium structure is a structure represented by the following formula (1): wherein R 11 represents a hydrogen atom, an alkyl group or a halogen atom, L 1 represents a single bond or a divalent connecting group, R 12 , R 13 and R 14 each independently represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group or an alkylidene group, or at least two of R 12 , R 13 and R 14 may be combined with each other to form a ring, and X − represents a counter ion necessary for neutralizing a charge, wherein the polymer containing as a repeating unit, a structural unit having an ammonium structure further contains a structural unit represented by the following formula (2): wherein R 21 represents a hydrogen atom, an alkyl group or a halogen atom, and R 22 represents an ester group, an amido group, a phenyl group which may have a substituent, or a group containing a polyalkyleneoxy group, wherein the image-recording layer comprises a sensitizing dye, a polymerization initiator, and a polymerizable monomer, wherein a molar ratio of the structural unit represented by the formula (1) to the structural unit represented by formula (2) in the polymer is from 10:90 to 50:50, and wherein the polymer containing, as a repeating unit, a structural unit having an ammonium structure is contained only in the protective layer.