ORIGINAL FILM FOR LITHOGRAPHIC PLATE

摘要

PROBLEM TO BE SOLVED: To provide a positive or negative original film for a lithographic plate which is improved in printing stain properties and enables attainment of a print wherein no stain occurs in a non-image part. SOLUTION: The original film for the lithographic plate has a constitution wherein a crosslinking hydrophilic layer containing a hydrophilic polymeric compound having a crosslinking structure and a hydrophilic graft chain and an image forming layer are laminated sequentially on a substrate. The crosslinking hydrophilic layer is obtained by a process wherein the hydrophilic polymeric compound having in a backbone polymer a group that can react with a crosslinking agent is made to react with the crosslinking agent. As for the image forming layer, it is preferably in a mode of containing a polymeric compound having a functional group of which the hydrophilicity/hydrophobicity is changed by an acid, heating or irradiation of a radiation.