Method for producing polyvinyl alcohol resin, and polyvinyl alcohol resin obtained by the method
AssigneeJapan Vam & Poval Co., Ltd.
InventorsAkinobu Oharuda, Masatoshi Kawanishi
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Abstract
Provided is a method for producing a polyvinyl alcohol resin, comprising the steps of copolymerizing an aliphatic vinyl ester (A) with diacetone acrylamide (B), at least a part of which diacetone acrylamide (B) is added at a later stage, in the presence of a polymerization catalyst in an alcohol solvent, so that the ratio (a)/(b) of the polymerization yield at the end of the polymerization (a) to the polymerization yield at the end of the later addition (b) of diacetone acrylamide (B) is in the range of 1.01 to 1.10, and saponifying the resulting copolymer.
Claims14
A method for producing a polyvinyl alcohol resin, comprising the steps of
- copolymerizing an aliphatic vinyl ester (A) with diacetone acrylamide (B) to obtain a copolymer, wherein at least a part of the diacetone acrylamide (B) is added at a later stage, in the presence of a polymerization catalyst in an alcohol solvent, so that a ratio (a)/(b) of a polymerization yield at the end of a polymerization (a) to a polymerization yield at the end of the later addition (b) of diacetone acrylamide (B) is in the range of 1.01 to 1.10, and
- saponifying the copolymer to obtain the polyvinyl alcohol resin.
Dependencies are inferred from the claim text.