(57) The present invention provides an infrared-sensitive positive-working photosensitive
lithographic printing plate precursor that exhibits both an excellent chemical resistance
in the image area and an excellent developability. This positive-working photosensitive
lithographic printing plate precursor comprises a support having a hydrophilic surface,
and a recording layer disposed on the support and comprising an alkali-soluble or
alkali-swellable polymer having a structural unit represented by general formula (1)
below, a novolac resin, an infrared absorber, and at least one member selected from
aromatic group-containing sulfonium salts and iodonium salts

wherein R1 represents a hydrogen atom or methyl group, X represents a single bond, -COO-, or
-CONH-, Ar1 and Ar2 each represent an optionally substituted aromatic group or heteroaromatic group,
and Y represents - SO2NH- or -NHSO2-.
|
|