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:
Jun. 16, 1998
Filed:
Mar. 31, 1997
Shin-Etsu Chemical Co., Ltd., Tokyo, JP;
Abstract
Proposed is a novel polysiloxane-polyether block copolymer having excellent heat resistance, which is characterized by the molecular structure consisting of repetition of diorganopolysiloxane units and polyoxyalkylene units having a bisphenol linkage of the formula --O--Pn--CMe.sub.2 --Pn--O-- in the unit, Pn being a 1,4-phenylene group and Me is a methyl group. This polysiloxane-polyether block copolymer can be prepared by conducting a hydrosilation reaction between a diorganopolysiloxane terminated at each molecular chain end with a silicon-bonded hydrogen atom and a polyoxyalkylene compound having the bisphenol linkage in the molecule and terminated at each molecular chain end with an alkenyl group or, preferably, allyl group in the presence of a platinum catalyst. The stability of the block copolymer obtained by the hydrosilation reaction can be further improved, when the block copolymer has a silicon-bonded hydrogen atom as the terminal group, by reacting the silicon-bonded hydrogen atom with water or alcohol to be converted into a silanolic hydroxy group or alkoxy group.