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:
Oct. 02, 1990
Filed:
Apr. 18, 1988
Lucien Billet, Vernaison, FR;
Jean-Jacques Lebrun, Caluire, FR;
Rhone-Poulenc Chimie, Courbevoie, FR;
Abstract
Polydiorganosiloxanes having silanol end groups, well suited for the production of vulcanizable silicone compositions, are conveniently prepared by bulk polycondensing a polydiorganosiloxane oligomer having silanol end groups in a closed reaction zone in the presence of a catalytically effective amount of trifluoromethylsulfonic acid, at a temperature of from 20.degree. to 160.degree. C., while continuously removing water of polycondensation, and terminating the polycondensation reaction by adding a catalyst neutralizing amount of a cyclopolydiorganosilazane or a polydiorganosilazane having diorganoaminosilyl end groups to the medium of reaction.