Continuous process for preparing organopolysiloxanes containing triorganosiloxy terminal units

US4792596A · kind A · utility

Assignee

• Wacker Chemie AG · DE

Inventors

• Ralph Ottlinger · Rosenheim, DE
• Willi Streckel · Schweich, DE

Key dates

• Filing date: Aug 12, 1987
• Grant date: Dec 20, 1988
• Expiry date: Aug 12, 2007

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G77/06
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Organopolysiloxanes containing triorganosiloxy terminal units are obtained by a continuous process in which an organopolysiloxane mixture containing organo(poly)siloxanes having triorganosiloxy terminal units and cyclic organopolysiloxanes are introduced into a tube reactor that has been heated to at least 80.degree. C. and which contains a static catalyst bed. The organopolysiloxane composition containing triorganosiloxy terminal units, which exits from the tube reactor is different from the organo(poly)siloxanes containing triorganosiloxy terminal units which were introduced into the reactor. The contents of the reactor in the area between one-third and two-thirds of the distance between the point where the organopolysiloxanes are introduced into the tube reactor and the point where the organopolysiloxanes exit from the reactor, are maintained at a temperature which is at least 50.degree. C. below that which is immediately upstream from the outlet of the reactor.