| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for industrially profucing a polyvinyl alcohol resin with good whiteness. SOLUTION: In the production of the polyvinyl alcohol resin by saponifying a vinylester polymer with an alkali catalyst, the neutralization after sapnification is performed using a polybasic acid having the first dissociation constant (pKa1 ) of 4.0 or less such as a citric acid, oxalic acid, malonic acid, maleic acid, phthalic acid, tartaric acid, glutaconic acid, aspartic acid, glutaminic acid, phosphoric acid, sulfuric acid or the like.
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