Title:
PRODUCTION OF VINYL CHLORIDE POLYMER
Document Type and Number:
Japanese Patent JPH1180214
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To produce a vinyl chloride polymer having a high bulk specific gravity at a high productivity by using a polymerizer having the inner wall coated with a polymer adhesion preventive, by using a dispersion stabilizer comprising specific ingredients, and by specifying the water/monomer ratio at the beginning of polymn. SOLUTION: A dispersion stabilizer comprising PVA (A) having a degree of saponification of 70-80 mol.% and an average degree of polymn (P) of 500-3,000 as the essential ingredient and at least one ingredient selected from among PVA (B) having a degree of saponification of 85-98 mol.% and a P of 300-4,000, PVA (C) having a cloud point (of 1% aq. soln.) of 60 deg.C or higher because of modification with hydrophilic groups and having a degree of saponification of 70-82 mol.% and a P of 500-3,000 and a nonionic surfactant (D) having an HLB of 10 or higher in a wt. ratio of A/(B+C+D) of (1/2)-(20/1) is used in an amt. of 0.04-0.15 pt.wt. based on 100 pts.wt. monomer. The water/monomer ratio (the wt. ratio of an aq. medium/a monomer) at the time when the polymn. temp. is reached is set at 0.40-0.80 and is adjusted to 0.60-1.20 by the addition of the aq. medium by the time when the conversion of the monomer into a polymer reaches 10%.
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Inventors:
SAWANO MASAO
TANAKA TOSHIHIKO
TANAKA TOSHIHIKO
Application Number:
JP23822897A
Publication Date:
March 26, 1999
Filing Date:
September 03, 1997
Export Citation:
Assignee:
TOSOH CORP
International Classes:
C08F2/00; C08F2/20; C08F14/00; C08F14/06; (IPC1-7): C08F2/20; C08F2/00; C08F14/06