Mixtures of linear and cyclic siloxanes or siloxane oligomers and a process for their preparation

US5282998A · kind A · utility

Assignee

• Huls Aktiengesellschaft · DE

Inventors

• Michael Horn · Rheinfelden (Baden), DE
• Hans-Joachim Kotzsch

Key dates

• Filing date: Jun 2, 1992
• Grant date: Feb 1, 1994
• Expiry date: Jun 2, 2012

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G77/045
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Mixtures of siloxane oligomers having a degree of oligomerization of 0 to 8, which have no more than one vinyl substituent attached per silicon atom as well as methoxy and/or ethoxy groups, the molar ratio of vinyl groups to alkoxy groups being 1:1 to 1:8, and in addition optionally alkyl substituents of 1 to 18 carbon atoms, the molar ratio of vinyl groups to alkyl groups being 1:0 to 1:8, are prepared by hydrolysis or cohydrolysis of vinyltrialkoxysilanes and optionally tetraalkoxysilanes and alkyltrialkoxysilanes in alcoholic solution in the presence of an acid catalyst with an amount of water calculated for the degree of oligomerization, followed by removal of the catalyst and of the free alcohol. The siloxane oligomer mixture is useful as a crosslinking agent for thermoplastic polyolefins.