Title:
POLYMERIZATION OF VINYL CHLORIDE POLYMER
Document Type and Number:
Japanese Patent JP3749005
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To stably obtain the polymer hardly generating fisheyes on its molding in good productivity by polymerizing a vinyl chloride monomer in the presence of three kinds of partially saponified polyvinyl alcohols as a dispersant in a suspension state.
SOLUTION: This method for producing a vinyl chloride polymer comprises polymerizing a vinyl chloride monomer in the presence of an oil-soluble radical polymerization initiator and in the coexistence of (A) a partially saponified polyvinyl alcohol having a polymerization degree of 30-1,000 and a saponification degree of 65-75 mol.% and containing mercapto groups at the molecular terminals, (B) a partially saponified polyvinyl alcohol having a polymerization degree of ≥2,000 and a saponification degree of ≥75%, and (C) a partially saponified polyvinyl alcohol having a polymerization degree of 100-700 and a saponification degree of 20-55% as a dispersant in an aqueous solvent in a suspension state by use of a polymerization device equipped with a reflux condenser. The components A, B and C are used in amounts of 0.01-0.03 pt.wt., 0.03-0.1 pt.wt., and 0.01-0.1 pt.wt., respectively, per 100 pts.wt. of the vinyl chloride monomer, and at a component A/component B weight ratio of 2/8 to 4/6.
Inventors:
Noriyuki Ishikawa
Toshihiko Tanaka
Toshihiko Tanaka
Application Number:
JP34934297A
Publication Date:
February 22, 2006
Filing Date:
December 18, 1997
Export Citation:
Assignee:
Ocean PVC Co., Ltd.
International Classes:
C08F2/20; C08F14/00; C08F14/06; (IPC1-7): C08F2/20; C08F14/06
Domestic Patent References:
| JP9110907A |
Attorney, Agent or Firm:
Akio Miyazaki
Shinichi Iwata
Masaaki Ogata
Nobuyuki Kaneda
Katsuhiro Ito
Ishibashi Masayuki
Shinichi Iwata
Masaaki Ogata
Nobuyuki Kaneda
Katsuhiro Ito
Ishibashi Masayuki