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. 20, 1990
Filed:
Aug. 03, 1988
Shuichi Inoue, Kamifukuoka, JP;
Satoru Hayase, Kamifukuoka, JP;
Central Glass Company, Limited, Ube City, JP;
Abstract
The disclosure relates to a graft polymerization method to form a fluorine-containing graft copolymer which is useful as a soft and flexible fluororesin intermediate between fluororubbers and crystalline fluororesins. The graft copolymer is formed by polymerizing a fluorine-containing crystalline polymer, e.g. copolymer of CTFE and ethylene, in water in the presence of a reducing agent and a fluorine-containing elastomeric copolymer which comprises peroxy groups and is dispersed in the water to become the 'trunk' of the graft copolymer. For example, the elastomeric copolymer is of vinylidene fluoride, CTFE and t-butyl peroxyallylcarbonate. An example of the reducing agent is sodium bisulfite, and optionally and additionally a source of a reducing metal ion such as ferric chloride may be used. This graft polymerization reaction can be carried out at a relatively low temperature, viz. at 20.degree.-50.degree. C., and the grafted crystalline polymer becomes sufficiently high in the degree of polymerization and in crystallinity.