Method for the production of co-extrudates composed of polystyrene and of a crosslinked polyvinylpyrrolidone with reduced residual styrene monomer content

US8420737B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Helmut Meffert · Mannheim, DE
• Marianna Pierobon · Ludwigshafen, DE
• Ates Erk · Karlsruhe, DE
• Hermann Josef Feise · Kleinniedesheim, DE
• Robert Bayer · Sinsheim, DE

Key dates

• Filing date: Sep 10, 2007
• Grant date: Apr 16, 2013
• Expiry date: Jun 23, 2029

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F6/003
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A method for removing residual styrene monomers from co-extrudates comprising polystyrene and water-insoluble, crosslinked polyvinylpyrrolidone, which comprises subjecting an aqueous suspension of the particulate solid co-extrudate to a heat treatment at temperatures of 60 to 99° C., the weight ratio of solid co-extrudate to water in the suspension being 1:1.5 to 1:20, and the concentration of the suspension being kept constant during the treatment.