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:
Feb. 20, 1990
Filed:
Dec. 07, 1988
Karl-Heinrich Wegehaupt, Burghausen, DE;
Karl Braunsperger, Burghausen, DE;
Gunter von Au, Burghausen, DE;
Fridolin Stary, Burghausen, DE;
Wacker-Chemie GmbH, Munich, DE;
Abstract
A process for preparing diorganopolysiloxanes having terminal Si-bonded hydroxyl groups which comprises reacting an organosilicon compound selected from a cyclic diorganopolysiloxane, a diorganodichlorosilane hydrolysis product and mixtures thereof with from 0.1 to 3 percent by weight of a diorganodichlorosilane, based on the weight of the organosilicon compound, i.e., the cyclic diorganopolysiloxane and/or diorganodichlorosilane hydrolysis product employed, in the presence of from 1 to 50 ppm by weight of phosphonitrile chloride, based on the total weight of the organosilicon compound and diorganodichlorosilane employed, to form diorganopolysiloxanes containing an Si-bonded chlorine atom in each of the terminal units, then treating the reaction mixture with water or an aqueous solution, separating off the aqueous phase from the diorganopolysiloxanes containing an Si-bonded hydroxyl group in each of the terminal units and thereafter removing the low boiling constituents by distillation.