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:
Feb. 21, 2006
Filed:
Mar. 01, 2005
Makoto Ooura, Kashima-gun, JP;
Tadashi Amano, Kashima-gun, JP;
Makoto Ooura, Kashima-gun, JP;
Tadashi Amano, Kashima-gun, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
A process for producing a vinyl chloride-based polymer by suspension polymerization is provided. The polymerization is initiated in the presence of (A) a particular hydroxypropylmethylcellulose, (B) a particular partially saponified PVA with a saponification degree of 75 to 85 mol % and an average polymerization degree of 1000 to 3000, and (C) a particular partially saponified PVA with a saponification degree of 20 to 57 mol % and an average polymerization degree of 150 to 600 in a specified ration, and said (C) is also additionally added to the polymerization system when a conversion rate is 15–50%. Polymers with a high porosity, excellent plasticizer absorption, extremely low levels of fish eyes, and a high bulk specific gravity are produced at a high level of productivity.