Patent ID: 7026097

Claim:
A planographic printing plate precursor comprising a photosensitive layer on a support, the photosensitive layer including an infrared absorbent, a radical polymerization initiator, a radical polymerizing compound and a binder comprising an ethyleneoxy group selected from —(CH 2 CH 2 O) n —CH 2 CR 1 ═CR 2 R 3 and —(CH 2 CH 2 O) n —COCH═CH 2 wherein R 1 to R 3 each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, an alkoxy group, and an aryloxy group, wherein R 1 and R 2 or R 3 may be bonded to each other to form a ring, and n is an integer of 1–10, the photosensitive layer being recordable with irradiation with an infrared ray, and being at least one of soluble and dispersible in water, wherein the resulting irradiated plate is capable of printing without being subjected to wet developing.