RELIEF PRINTING PLATE FOR APPLYING VARNISH FOR OFFSET PRINTING WITHOUT REQUIRING DEVELOPING PROCESS

摘要

PROBLEM TO BE SOLVED: To obtain a relief printing plate which does not require a developing process by using a photosensitive color coating agent containing a photofading dye and photopolymn. initiator as an essential component to form a relief image. SOLUTION: A PET film and a synthetic rubber material are laminated and plate thickness adjustment and vulcanization are performed at one time. Then, a soln. of a photosensitive color coating agent having photofading property is applied to obtain a laminated body (relief printing plate material). The photosensitive color coating agent is a compsn. containing a photofading dye, a photopolymn. initiator and a polymer matrix. As for the photofading dye, the compd. which fades by exposure to UV rays in a short time and which forms an image of high contrast is preferable. Then, a photographic film is tightly adhered to the relief printing plate and irradiated with UV rays by using an exposure device for photograving. Then, a base material in an unexposed region is peeled off by using a blade to produce a relief printing plate.