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:
Jul. 02, 1991
Filed:
Oct. 02, 1989
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
Perfluoroalkyl group containing organopolysiloxanes having a high degree of polymerization can be prepared by reacting a liquid organopolysiloxane of formula (I): R.sup.1.sub.aR.sup.2.sub.b (OH).sub.c SiO.sub.[4.(a+b+c)]/2 with an alkali metal hydroxide to form an alkali metal silanolate; reacting the alkali metal silanolate with a perfluoroalkyl group-containing organosilane of formula (II): RfR.sup.3 SiX.sub.2 to synthesize a perfluoroalkyl group-containing organopolysiloxane intermediate of formula (III): [(R.sup.1.sub.a R.sup.2.sub.b SiO).sub.m (RfR.sup.3 SiO)].sub.n ; and polymerizing the intermediate of formula (III) or a mixture of the intermediate and an organopolysiloxane of formula (IV): R.sup.5.sub.e R.sup.6.sub.g SiO.sub.[(4.(e+g)]/2 in the presence of a strongly acidic catalyst or strongly basic catalyst.