Title:
PRODUCTION OF VINYL CHLORIDE POLYMER
Document Type and Number:
Japanese Patent JP3254772
Kind Code:
B2
Abstract:
PURPOSE: To produce a vinyl chloride polymer reduced in the formation of fish eyes at a high productivity by polymerizing vinyl chloride in suspension in an aq. medium in the presence of a specific dispersant and adding water to the polymn. system in a specified manner.
CONSTITUTION: Vinyl chloride is polymerized in suspension in an aq. medium in the presence of a dispersant comprising polyvinyl alcohol having a degree of saponification of 75-85mol% and a viscosity in an aq. 4-wt.% soln. at 20°C of 30-50cP and polyvinyl alcohol having a degree of saponification of 30-55mol% and a viscosity in a 10-wt.% soln. in a 1:1 water-methanol mixture at 20°C of 7-23cP. In the polymn., water in an amt. not exceeding the amt. of decrease in vol. of the suspension due to the progress of polymn. is added at once or in portions to the polymn. system so that the vol. of the suspension at a conversion of 50-70% is equal to the vol. before polymn. Then, the polymn. is continued to give the objective vinyl chloride polymer.
Inventors:
Madoka Furuta
Kunihiko Sato
Hiroshi Minemura
Naonori Asada
Yoshihito Fujiki
Kunihiko Sato
Hiroshi Minemura
Naonori Asada
Yoshihito Fujiki
Application Number:
JP33550092A
Publication Date:
February 12, 2002
Filing Date:
November 20, 1992
Export Citation:
Assignee:
Toagosei Co., Ltd.
International Classes:
C08F2/20; C08F2/18; C08F14/00; C08F14/06; (IPC1-7): C08F2/20; C08F14/06
Domestic Patent References:
| JP53136089A | ||||
| JP5938212A |
Attorney, Agent or Firm:
Toru Takatsuki