Title:
PRODUCTION OF VINYL CHLORIDE POLYMER
Document Type and Number:
Japanese Patent JP3257174
Kind Code:
B2
Abstract:
PURPOSE: To produce a vinyl chloride polymer having a highly porous particle structure, excellent processability and low fish-eye content by polymerizing vinyl chloride in the presence of a partially saponified polyvinyl alcohol as a dispersing agent while adding a suspending agent to the system.
CONSTITUTION: Vinyl chloride or a monomer mixture containing vinyl chloride is suspension polymerized in an aqueous medium in the presence of 0.01-5 pts.wt. (based on 100 pts.wt. of the monomer) of a partially saponified polyvinyl alcohol having an average polymerization degree of 150-600 and a saponification degree of 20-60mol% as a dispersing agent while continuously or intermittently adding a suspension agent having a water solubility higher than that of the alcohol from the start of polymerization until the polymerization ratio reaches 5-50%. The suspension agent is a water-soluble partially saponified polyvinyl alcohol having an average polymerization degree of 700-3,000 and a saponification degree of 70-85mol% or a hydroxypropylmethylcellulose having a me thoxy substitution degree of 26-30wt.% and a hydroxypropoxy substitution degree of 4-15wt.% and the compounding amount of the suspension agent is 0.03-0.1 pts.wt.
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Inventors:
Makoto Fujiwara
Tadashi Amano
Tadashi Amano
Application Number:
JP21701293A
Publication Date:
February 18, 2002
Filing Date:
August 09, 1993
Export Citation:
Assignee:
Shin-Etsu Chemical Co., Ltd.
International Classes:
C08F2/20; C08F2/18; C08F14/00; C08F14/06; (IPC1-7): C08F2/20
Domestic Patent References:
| JP60229907A |
Attorney, Agent or Firm:
Takashi Kojima