Process for preparing colloidal suspensions of organopolysiloxanes

US4857582A · kind A · utility

Assignee

• Wacker Chemie AG · DE

Inventors

• Matthias Wolfgruber · Burghausen, DE
• Bernward Deubzer · Burghausen, DE
• Volker Frey · Burghausen, DE

Key dates

• Filing date: May 18, 1988
• Grant date: Aug 15, 1989
• Expiry date: May 18, 2008

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08J2383/04
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

Colloidal suspensions of organopolysiloxanes are prepared by mixing an organosilicon compound selected from the group consisting of mixtures of alkoxysilanes and/or partial hydrolysates thereof and an organo(poly)siloxane which is optionally free of alkoxy groups and contains a maximum of 8 siloxane units, which is mixed with at least one alkoxysilane and/or a partial hydrolysate thereof, with water in the presence of an emulsifier, at a maximum rate of 5 moles of organosilicon compound per hour per liter of water, in which the organosilicon compound and the water is fed continuously, but separately from one another, into a reactor, in which at least one of the two substances contains an emulsifier, while the alkanol is being continuously removed by distillation from the aqueous suspension continuously emerging from the reactor. The aqueous suspension from which the alkanol has been removed by distillation is, if desired, recycled back into the reactor. A tubular reactor is preferably employed in which the water is added continuously at, or near the upper end of the tubular reactor and the organosilicon compound is added via several inlet points arranged along the longitudinal axis…