The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 15, 1994
Filed:
Nov. 09, 1992
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
A process for producing a vinyl chloride polymer by polymerizing a monomer comprising vinyl chloride by suspension polymerization in a polymerization vessel on the inner wall surface of which a coating of a polymer scale preventive agent is formed, comprising the steps of applying a high-speed shearing force to a mixture comprising water, the monomer, a polymerization initiator, and (A) a dispersant comprising a partially saponified polyvinyl alcohol having a specified average degree of polymerization and a specified degree of saponification plus (B) a dispersant comprising a hydroxypropylmethylcellulose which has a specified methoxyl substitution degree, a specified hydroxypropoxyl substitution degree, and a specified viscosity and subjecting the mixture to said suspension polymerization. A vinyl chloride polymer having an average particle diameter of 200 to 600 .mu.m and a narrow particle size distribution and excellent in plasticizer take-up, etc. is provided.