| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polyvinyl alcohol polymer which can retain its gas barrier properties even at a high humidity by hydrolyzing a homopolymer of vinylene carbonate or a copolymer thereof with a specific compd. SOLUTION: This polymer is a hydrolyzate of a homopolymer of vinylene carbonate or a hydrolyzate of a copolymer or terpolymer of vinylene carbonate and a compd. or compds. represented by formula I (R1 , R2 , and R3 are each a group represented by formula II). Vinyl acetate, isopropenyl acetate, 2-propenyl acetate, vinylα-chloroacetate, etc., can be used as the compd. represented by formula I. The amt. of vinylene carbonate (co)polymerized is at least 10mol%. A polymer obtd. by the (co)polymn. is hydrolyzed under an alkaline condition to give the objective polymer. This polymer is melt extruded onto or applied as a soln. to a substrate film to give a wrapping material.
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