Preparation of thermoplastics

US5851463A · kind A · utility

Assignee

• BASF SE

Inventors

• Norbert Güntherberg · Speyer, DE
• Jurgen Hofmann · Spalt, DE
• Elmar Mailahn · Worms, DE
• Hilmar Ohlig · Kaiserslautern, DE

Key dates

• Filing date: Mar 22, 1996
• Grant date: Dec 22, 1998
• Expiry date: Mar 22, 2016

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C48/762
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

Toughened thermoplastics are prepared by mechanically dewatering a water-moist elastomer component A containing up to 50% by weight of residual water and mixing the resulting dewatered elastomer component A' with a thermoplastic polymer B in a mixing unit, by a process in which the elastomer component A is fed to a twin-screw extruder which has corotating, in each case triple-flight, screws and essentially includes, in the transport direction, PA1 one unheated metering section in which the elastomer component A is fed to the extruder by a metering means, PA1 at least one squeeze section which serves for dewatering and contains at least one retarding element and in each case at least one associated dewatering orifice, PA1 at least one section in which the thermoplastic polymer B is introduced as a melt into the extruder, PA1 at least one section provided with mixing, kneading or other plasticating elements or combinations of these elements, PA1 at least one devolatilization section which is provided with at least one devolatilization orifice and in which the residual water is removed as steam, and PA1 unheated discharge zone, and in which the water emerging from the dewatering orifi…