Process for the preparation of SiOC-linked, linear polydimethylsiloxane-polyoxyalkylene block copolymers and their use

US7825205B2 · kind B2 · utility

Assignee

• EVONIK GOLDSCHMIDT GMBH · DE

Inventors

• Wilfried Knott · Essen, DE
• Juergen Droese · Essen, DE
• Klaus Dieter Klein · Wiesloch, DE
• Rüdiger Landers · Essen, DE
• Dagmar Windbiel · Essen, DE

Key dates

• Filing date: Dec 14, 2007
• Grant date: Nov 2, 2010
• Expiry date: Sep 22, 2028

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G2110/0083
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to a process for the preparation of SiOC-linked, linear polydimethylsiloxane-polyoxyalkylene block copolymers having (AB) repeat units, via reaction by methods known per se of polyetherdiols with a stoichiometric excess of α,ω-dihydropolydimethylsiloxanes, in the presence of one or more compounds of elements of main group 13 and/or of transition group 3 as catalyst, which comprises, after completed reaction of the alcohol component, continuing the reaction until no remaining ≡Si(H) groups are detectable by a gas-volumetric method, and also to the compounds thus prepared, and to their use as surfactant additives for the production of polyurethane ether foams.