To provide a platemaking method for a photopolymerizable photosensitive lithographic printing plate having high sensitivity, printing durability and chemical resistance and excellent in suitability to a yellow fluorescent light for a PS plate, and to provide a lithographic printing plate obtained by the platemaking method.
In the platemaking method for a photosensitive lithographic printing plate, the photosensitive lithographic printing plate whose photopolymerizable photosensitive layer contains at least the following components (a)-(d) is handled under yellow safelight having an illuminance of 100-500 Lx from which wavelengths of ≤450 nm have been cut and then an image is formed; (a) an addition-polymerizable ethylenic double bond-containing compound having a tertiary amino group, (b) a (meth)acryloyl group-containing alkali-soluble resin binder obtained by reacting a vinyl copolymer using (meth)acrylic acid as a constituent monomer with an epoxy compound having a (meth)acryloyl group, (c) a hexaarylbisimidazole compound as a photopolymerization initiator, (d) a compound selected from the merocyanine dyes represented by formula (I).