Polyvinyl photopolymer printing

Synthesis and Properties of Photopolymer Printing Plates for a Printing Master Plate by Modification of Polyvinyl Alcohol... 

A number of photopolymer printing plates are already known. Their basic structures are to combine one of the general purpose resins such as cellulose (1), polyamide (2J, polyester, poly urethane (3j, polyvinyl alcohol (4), synthetic rubber (5) and the like with photopolymerizing vinyl monomer, photopolymerization initiator and so on. Any one of the plates of such structures can be used as a press plate, but they can not be used as an original plate for duplicate plate owing to their insufficient hardness, toughness and the similar negative properties. 

Therefore, metal plates have been conventionally used. We have performed the research and development of a photopolymer printing plate for a master plate with a new basic structure by combining an oligomer of urea structure having a polyvinyl base with polyvinyl alcohol, photopolymerization initiator and other ingredients. The result shows that the newly developed plate (6) is so good that it has replaced metal plates and has been stably used at leading newspaper companies in Japan where several millions of newspapers are daily issued. 

The Photopolymer Plate, a water developable photopolymer relief printing master plate made by modification of polyvinyl alcohol with urea group oligomer having a functional polyvinyl base, for making paper mold and matrix for printing master plates, has characteristics which are very close to those of the conventionally etched metal relief printing plates and has some superior points to them. 

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