Production of ethylene copolymers

US4260722A · kind A · utility

Assignee

• BASF SE

Inventors

• Klaus Pfleger · Wesseling, DE
• Wieland Zacher
• Klaus Boettcher
• Ronald Skorczyk · Bonn, DE
• Oskar Buechner · Dudenhofen, DE
• Franz G. Mietzner · Ludwigshafen, DE

Key dates

• Filing date: Nov 27, 1979
• Grant date: Apr 7, 1981
• Expiry date: Nov 27, 1999

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08F210/02
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

A process for the continuous production of an ethylene copolymer by compressing a mixture of ethylene and comonomer in a pre-compressor and a post-compressor, copolymerizing the mixture in a polymerization zone at a high temperature and high pressure, transferring the reaction mixture into a high pressure product isolation zone, from there into a low pressure product isolation zone and thereafter into a discharge extruder, and recycling the greater part of the unconverted monomer into the polymerization process and passing a small part of the unconverted gas into a low temperature isolation zone, in which process a small part of the gas recycled from the high pressure product isolation zone is passed into the low temperature isolation zone, which is preferably under a pressure of from 10 to 30 bar and at from -10.degree. to -50.degree. C., and all the gas taken off the low pressure product isolation zone is fed to the pre-compressor. Using the novel process, the separating-off of the comonomer which has remained unconverted in the polymerization process can be improved.