Patent ID: 8771920

Claim:
A positive lithographic printing plate precursor with an infrared-sensitivity, having a support and an image recording layer provided on the support, the support having a hydrophilic surface, the recording layer comprising: a maleimide resin A; an amphoteric surfactant and/or an anionic surfactant; and an infrared absorbing agent; the maleimide resin A being a copolymer formed from monomers containing: methacrylic acid; at least one kind of compound selected from the group consisting of N-phenylmaleimide, N-cyclohexylmaleimide and N-benzylmaleimide; and a monomer having a structure represented by formula (A): wherein R 21 represents a hydrogen atom or a methyl group; X represents an alkylene group having 2 to 12 carbon atoms, an oxyalkylene group having 4 to 8 carbon atoms or —SiRa 2 —; Ra represents an alkyl group and the two (2) alkyl groups represented by Ra may be the same as or different from each other; and m represents an integer of 1 to 3.