Title:
PRODUCTION OF POLYVINYL ALCOHOL RESIN
Document Type and Number:
Japanese Patent JPH05320219
Kind Code:
A
Abstract:
PURPOSE:To obtain a polyvinyl alcohol resin which is lowly colored, has excellent heat stability and is difficultly discolored even when heated by polymerizing a vinyl ester in the presence of a specified peroxyester compound as a polymerization initiator and saponifying the obtained vinyl ester resin. CONSTITUTION:A vinyl ester (e.g. vinyl acetate) is polymerized by, for example, solution polymerization in the presence of 0.00001-0.05mol%, based on the monomer, peroxyester compound of the formula (wherein R1 to R6 are each H or 1-6 C alkyl) (e.g. t-hexyl peroxyneodecanoate) as a polymerization initiator. A small amount of a chain transfer agent may be used in this polymerization. Unreacted monomer is removed from the obtained polyvinyl ester by for example, vacuum treatment. After at most 1mol, per mol of the vinyl ester units, of a saponification catalyst (e.g. alkali) is added to the polyvinyl ester, it is saponified. The obtained polyvinyl alcohol resin is optionally subjected to after- treatments and dried by heating, application of a vacuum or the like into a powder.
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Inventors:
OGAWA SEIYA
YAMAMOTO NORIMASA
KATO SADANOBU
YAMAMOTO NORIMASA
KATO SADANOBU
Application Number:
JP15984891A
Publication Date:
December 03, 1993
Filing Date:
June 05, 1991
Export Citation:
Assignee:
DENKI KAGAKU KOGYO KK
International Classes:
C08F4/34; C08F4/28; C08F8/12; C08F16/02; C08F16/06; C08F18/00; C08F18/04; (IPC1-7): C08F4/34; C08F8/12; C08F16/06; C08F18/04
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