Process for preparing diorganopolysiloxanes containing triorganosiloxy terminal groups

US4835237A · kind A · utility

Assignee

• Wacker Chemie AG · DE

Inventors

• Jurgen Burkhardt · Burgkirchen an der Alz, DE
• Andreas Bock · Neuss, DE

Key dates

• Filing date: Apr 1, 1988
• Grant date: May 30, 1989
• Expiry date: Apr 1, 2008

Classification

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

Abstract

Diorganopolysiloxanes containing triorganosiloxy groups as terminal units are prepared by mixing the diorganopolysiloxanes which may already contain triorganosiloxy terminal groups, after they have reached the desired average viscosity by condensation and/or equilibration in the presence of catalysts other than chlorophosphazenes, with a hexaorganodisilazane in an amount of from 0.05 to 2 percent by weight, based on the weight of the diorganopolysiloxanes employed and after mixing, a catalytic amount of a chlorophosphazene is added.