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:
May. 10, 1994
Filed:
May. 19, 1993
Shuji Ohnishi, Lake Jackson, TX (US);
Tadashi Amano, Kamisu, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
A process for producing a vinyl chloride-based polymer in which an aqueous suspension of a vinyl chloride-based monomeric material placed in a polymerization vessel equipped with an agitating element is subjected to suspension polymerization by introducing a polymerization initiator to the aqueous suspension at a position located inside the diameter of the agitating element being rotated. By this process it is possible to prevent totally the deposition of polymer scale on the inside wall of the polymerization vessel, particularly in the vicinity of a gas-liquid interface. Therefore, troubles arising from polymer scale formation and labor needed for removing such polymer scale are obviated, and a vinyl chloride-based polymer of high quality can be produced efficiently.