Title:
PRODUCTION OF POLYVINYL ALCOHOL EXCELLENT IN STABILITY OF VISCOSITY AT LOW TEMPERATURE
Document Type and Number:
Japanese Patent JP3659798
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing polyvinyl alcohol, capable of simply carrying out control, or the like, of aqueous solution, treating it in similar method as conventional polyvinyl alcohol and obtaining the subject polymer excellent in stability of viscosity at low temperature by polymerizing a fatty acid vinyl ester under specific condition and saponifying the resultant polymer.
SOLUTION: A fatty acid vinyl ester is polymerized under a pressure in a polymerizer kept in a pressure higher than atmospheric pressure by vapor of unreacted fatty acid vinyl ester in a polymerizer or by a non-condensable gas (e.g. nitrogen) at a temperature higher by 2-80°C, preferably 5-50°C than boiling point temperature of reaction solution under atmospheric pressure, and then, the resultant polymer is saponified. Vinyl acetate is industrially preferable as the fatty acid vinyl ester. Solution polymerization is industrially preferably used as the fatty acid. Methanol is industrially preferable in the polymerization method. The polymerization degree of the objective polymer is usually 50-4,000 and the saponification degree is usually ≥60 mol.%.
Inventors:
Toshifumi Matsuoka
Keiji Yukawa
Takatoshi Mineo
Takashi Nakajima
Hiroshi Noguchi
Keiji Yukawa
Takatoshi Mineo
Takashi Nakajima
Hiroshi Noguchi
Application Number:
JP9524798A
Publication Date:
June 15, 2005
Filing Date:
March 25, 1998
Export Citation:
Assignee:
Japan Vinegar Poval Co., Ltd.
International Classes:
C08F2/00; C08F8/12; C08F16/06; C08F18/04; (IPC1-7): C08F2/00; C08F8/12; C08F16/06; C08F18/04
Domestic Patent References:
| JP45020500B1 | ||||
| JP11279986A |
Attorney, Agent or Firm:
Ryu Iwatani
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