Process for producing thermoplastics

US6165399A · kind A · utility

Assignee

• BASF SE

Inventors

• Norbert Güntherberg · Speyer, DE
• Jurgen Hofmann · Spalt, DE
• Elmar Mailahn · Worms, DE
• Hilmar Ohlig · Kaiserslautern, DE
• Bernhard Czauderna · Hirschberg, DE
• Sven Grabowski · Ludwigshafen, DE
• Klaus Bus · Kaiserslautern, DE

Key dates

• Filing date: Mar 25, 1999
• Grant date: Dec 26, 2000
• Expiry date: Mar 25, 2019

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B29C48/41
• WIPO field: Other special machines
• WIPO sector: Mechanical engineering

Abstract

A process for preparing thermoplastics or polymer blends comprising (A) from 5 to 95% of a water-moist elastomer component containing up to 60% of residual water, (B) from 5 to 95% of a thermoplastic polymer, (C) from 0 to 95% of a further polymer, and (D) from 0 to 70% of additives, said process comprising mixing the components A to D in an extruder with mechanical dewatering of component A, wherein the extruder has at least two rotating screws and, in the conveying direction, is essentially composed of a metering section into which component A is fed, a squeeze section which serves for dewatering component A and contains a retarding element and an associated dewatering orifice which is present upstream of the retarding element by a distance corresponding to at least one screw diameter, a feed section in which the thermoplastic polymer B is introduced as a melt into the extruder, a plastication section with mixing or kneading elements, a devolatilization section with an orifice and in which the remaining water is removed as steam, and a discharge zone.