POSITIVE TYPE PHOTOSENSITIVE PLANOGRAPHIC PRINTING PLATE, METHOD OF PRODUCING THE SAME AND PLATE MAKING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method of producing a positive type photosensitive planographic printing plate satisfying stable performance without seasonal variations and the shortening of production process at the same time for the object of forming a positive type photosensitive composition film suitable for direct recording with a semiconductor laser, YAG laser or the like and having high sensitivity, good preservability, chemical resistance and resistance to printing wear. SOLUTION: The method of producing the positive type photosensitive planographic printing plate characterized in that after the photosensitive layer is set by coating, and a dry treatment is carried out at a temperature of 30-100 deg.C and at a dew point of 5-30 deg.C in the method of producing the positive type photosensitive planographic printing plate formed by setting of a photosensitive layer containing a photosensitizing dye capable of absorbing at least one beam in the wave length range of 600 nm-1300 nm, a novolak resin and/or a polyvinyl phenol resin by coating on a supporting body.