LITHOGRAPHIC PRINTING PLATE ORIGINAL

PROBLEM TO BE SOLVED: To provide a negative image recording material for dealing with a heat mode in which ablation by laser scanning in recording is suppressed and from which a lithographic printing plate having high strength of a formed image part and excellent plate wear can be formed. SOLUTION: The recording material contains (A) polyurethane resin insoluble with water and soluble with an alkali aqueous solution, (B) a radical polymerizable compound, (C) a photo-thermal converting agent and (D) a compound generating a radical by heat-mode exposure to light at a wavelength where the photo-thermal converting agent(C) can absorb, in which an image can be recorded by heat-mode exposure. The polyurethane resin (A) preferably has a structural unit as a basic skeleton expressed by a reaction product of a diisocyanate compound expressed by general formula (2):OCN-X0-NCO and a diol compound expressed by general formula (3):HO-Y0-OH. COPYRIGHT: (C)2009,JPO&INPIT