Abstract: A process for preparing diorganopolysiloxanes containing terminal triorganosiloxy groups which comprises reacting in a 1st step, a cyclic diorganopolysiloxane and/or diorganodichlorosilane hydrolyzate with from 0.05 to 3 percent by weight of triorganochlorosilane, based on the weight of the cyclic diorganopolysiloxane and/or diorganodichlorosilane hydrolyzate employed in the presence of from 1 to 50 ppm by weight of phosphonitrile chloride, based on the total weight of the organosilicon compounds employed, to form a reaction mixture containing .alpha.-triorganosiloxy-.omega.-chlorodiorganopolysiloxane, and in a 2nd step, adding to the reaction mixture obtained in the 1st step and containing the .alpha.-triorganosiloxy-.omega.-chlorodiorganopolysiloxane, a diorganopolysiloxane having one Si-bonded hydroxyl group in each of the terminal units in an amount of from 1 to 1.
Type:
Grant
Filed:
November 14, 1988
Date of Patent:
December 4, 1990
Assignee:
Wacker-Chemie GmbH
Inventors:
Karl-Heinrich Wegehaupt, Karl Braunsperger, Jorg Patzke