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US09074031B2 Method for producing polyvinyl alcohol resin 有权
聚乙烯醇树脂的制造方法

Method for producing polyvinyl alcohol resin
Abstract:
Provided is a method of producing a polyvinyl alcohol resin, wherein the impurities in the resin are removed efficiently with a small amount of a washing liquid. A polyvinyl alcohol obtained after a polymerization step (step S1) and a saponification step (step S2) is washed with a washing liquid consisting of methyl acetate: 1 to 40 parts by mass, methanol: 50 to 98.9 parts by mass and water: 0.1 to 10 parts by mass in a washing step (step S3). The solid matter concentration of the slurry containing the washing liquid then is 1 to 30 mass %.
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