Modified poly(organo-organosiloxanes) with comb or block structures and a process for their preparation

US5061762A · kind A · utility

Assignee

• Wacker Chemie AG · DE

Inventors

• Gerald Fleischmann · Emmerting, DE
• Herbert Eck · Burghausen, DE
• Johann Schuster · Oberasbach, DE

Key dates

• Filing date: Aug 3, 1989
• Grant date: Oct 29, 1991
• Expiry date: Aug 3, 2009

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G77/442
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

The invention relates to modified poly(organo-organosiloxanes) with comb and/or block structures, which consist of a substantially linear diorganopolysiloxane base with organic polymers based on acrylates arranged in terminal positions and/or along the chain. These block polymers can be prepared by a two-step process. In a first process step, alkenyl trialkylsilylacetates are added to polyorgano-H-siloxanes in the presence of, for example, platinum catalysts and in a second process step, polar compounds, such as acrylates or methacrylates are graft copolymerized onto the polyorganosiloxanes modified with trialkylsilylacetoxyalkyl groups obtained above, in the presence of, for example, nucleophilic catalysts according to the principle of the group-transfer method. In a similar process, the polar compounds can be polymerized by the group-transfer method with alkenyl trialkylsilylacetates and the polymeric acrylic compounds modified with terminal acetoxyalkenyl groups thus obtained can be added to the polyorgano-H-siloxanes.