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:
Nov. 08, 1994
Filed:
Jun. 11, 1993
Makoto Fujiwara, Kamisu, JP;
Tadashi Amano, Kamisu, JP;
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
The preparation of vinyl chloride-type polymers by suspension polymerization of vinyl chloride monomers in the presence of monomer-soluble polymerization initiators, wherein the monomer-soluble polymerization initiators utilized are a combination of (A) a compound which possesses neither a benzene ring nor an alkoxyl group, and has a half-life of 10 hours at 0.1 mol/l concentration in benzene solution at a temperature of 40.degree.-50.degree. C., and (B) 1-cyclohexyl-1-methylethylperoxy pivalate. This method yields vinyl chloride-type polymers the qualities of which such as an initial colorization and thermal stability are effectively improved, without being affected by the limitations accompanied by the insufficient cooling capacity of the polymerization vessel in general. The preparative method further enables one to effectively avoid scale deposition in the polymerization vessel.