Title:
METHOD FOR PRODUCING POLYVINYL ALCOHOL
Document Type and Number:
WIPO Patent Application WO/2020/022016
Kind Code:
A1
Abstract:
Provided is a method whereby polyvinyl alcohol having excellent mechanical strength is produced without considerably lowering productivity. The method for producing polyvinyl alcohol, said polyvinyl alcohol having an average degree of polymerization of from 5.0x103 to 1.5x104 inclusive, comprises: a step for suspension polymerizing a vinyl ester-based monomer at a polymerization temperature of 10-50°C inclusive and at a polymerization rate of 10-70% inclusive to give a vinyl ester-based polymer; a step for dissolving the vinyl ester-based polymer in an alcoholic solvent; and a step for adding a saponification catalyst to the alcoholic solution of the vinyl ester-based polymer dissolved therein and thus performing a saponification reaction.
Inventors:
YAMASHITA AKIHIRO (JP)
Application Number:
PCT/JP2019/026528
Publication Date:
January 30, 2020
Filing Date:
July 03, 2019
Export Citation:
Assignee:
DENKA COMPANY LTD (JP)
International Classes:
C08F8/12; C08F18/04
Domestic Patent References:
| WO2016076349A1 | 2016-05-19 | |||
| WO2016060241A1 | 2016-04-21 |
Foreign References:
| JP2013177646A | 2013-09-09 | |||
| JPH05117307A | 1993-05-14 | |||
| JPH03287630A | 1991-12-18 | |||
| JPH03287631A | 1991-12-18 | |||
| JPS60190223A | 1985-09-27 | |||
| JP2009108218A | 2009-05-21 | |||
| JP2015187215A | 2015-10-29 | |||
| JPS61148209A | 1986-07-05 | |||
| JPS6337106A | 1988-02-17 | |||
| JPS63284206A | 1988-11-21 | |||
| JP2010202840A | 2010-09-16 | |||
| JP2014031487A | 2014-02-20 | |||
| JP2015187215A | 2015-10-29 |
Other References:
NAGANOYAMANETOYOSHIMA: "Poval", 1981, POLYMER PUBLISHING ASSOCIATION, pages: 105 - 107
See also references of EP 3792289A4
See also references of EP 3792289A4
Attorney, Agent or Firm:
AXIS PATENT INTERNATIONAL (JP)
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