Patent ID: 7811742

Claim:
A lithographic printing plate precursor comprising: a support; and a photosensitive layer comprising: a binder polymer which is soluble in a solution having pH of 2.0 to 6.5 and is a (meth)acrylic resin or a urethane resin and containing a positively charged nitrogen atom in at least one of a main chain and a side chain of the binder polymer; a compound containing an ethylenically unsaturated bond; and a radical polymerization initiator; wherein the binder polymer contains a group represented by one of the following formulae (1) to (4): wherein R 1 to R 7 each represents a monovalent substituent, or R 1 and R 2 or two of R 4 to R 6 may be combined with each other to form a ring, and X − represents an anion; and at least one of R 1 and R 2 , R 3 , at least one of R 4 to R 6 , and R 7 in the formulae (1) to (4) is a hydrogen atom.