Preparation of polystyrene by continuous anionic polymerization

US5902865A · kind A · utility

Assignee

• BASF SE

Inventors

• Hermann Gausepohl · Mutterstadt, DE
• Wolfgang Fischer · Meerbusch, DE
• Wolfgang Loth · Bad Dürkheim, DE
• Reiner Thiele · Kaiserslautern, DE

Key dates

• Filing date: May 6, 1997
• Grant date: May 11, 1999
• Expiry date: May 6, 2017

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01J2219/00094
• WIPO field: Macromolecular chemistry, polymers
• WIPO sector: Chemistry

Abstract

In a process for preparing polystyrene by continuous anionic polymerization of styrene monomer by means of a catalyst based on a metal alkyl preferably in the presence of a solvent at a temperature in the range from 30 to 70.degree. C., the styrene monomer is fed to an essentially isothermally operated circulation reactor configured as a closed tube loop which has, for example, a specific cooling area of at least 50 m.sup.2 per m.sup.3 of reactor volume, with the circulation velocity of the reaction mixture and the residence time being set such that the monomer conversion reaches at least 50% and the polymerization is completed in an essentially backmixing-free tube reactor.