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:
Dec. 29, 1981
Filed:
Jul. 18, 1980
Claude Millet, Saint-Priest, FR;
Rhone-Poulenc Industries, Paris, FR;
Abstract
High molecular weight organopolysiloxanes are rapidly prepared, without formation of the low molecular weight polysiloxanes, by polycondensing a hydroxysilylated polysiloxane in the presence of a catalytic amount of a catalyst system including (i) an alkali or alkaline earth metal, and (ii) a polyheteromacropolycyclic co-catalyst having the structural formula: ##STR1## wherein .SIGMA. is a divalent radical having the structural formula ##STR2## or a divalent radical having the structural formula: ##STR3## further wherein each R, which may be identical or different, is a divalent hydrocarbon radical, each Q, which also may be identical or different, is a divalent hydrocarbon radical, an oxygen atom or a sulfur atom, and m, n and p are each integers equal to 1, 2 or 3.