Process for preparing SiC-Bonded polyethersiloxanes

US10519280B2 · kind B2 · utility

Assignee

• EVONIK DEGUSSA GMBH · DE

Inventors

• Wilfried Knott · Essen, DE
• Dagmar Windbiel · Essen, DE

Key dates

• Filing date: May 14, 2018
• Grant date: Dec 31, 2019
• Expiry date: Jul 26, 2038

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G77/70
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for preparing SiC-bonded polyethersiloxanes by precious metal-catalysed addition of olefinically unsaturated polyethers onto siloxanes having SiH groups is described, in which, prior to commencement of reaction, the siloxane having SiH groups is mixed together with a polyethersiloxane, preferably by stirring, and then, in a second step, this preliminary mixture is contacted with an olefinically unsaturated polyether and with a precious metal catalyst and optionally further additives, preferably with further stirring, and the SiC bond formation reaction is conducted up to an SiH conversion, determined by gas-volumetric means, of at least 97%.