Patent ID: 8127675

Claim:
A lithographic printing method comprising printing by loading a lithographic printing plate precursor on a printing press without passing through a development process after recording an image or by recording an image after loading the lithographic printing plate precursor on a printing press, wherein the lithographic printing plate precursor comprises, in the following order: a support; a radical-polymerizable image recording layer capable of drawing an image by exposure with an infrared laser, which allows for printing by loading the precursor on a printing press without passing through a development process after recording an image or by recording an image after loading the precursor on a printing press; and a protective layer, and wherein the radical-polymerizable image recording layer comprises a radical-polymerizable compound, an infrared absorbent and an iodonium salt represented by the following formula (1a): wherein Ar 1a represents a benzene ring having a substituent, provided that a total of Hammett's σ values of substituents is a negative value, Ar 2a represents a benzene ring having a substituent, provided that a total of Hammett's σ values of substituents is a positive value, and Z represents a counter anion.