The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 11, 1999
Filed:
May. 06, 1997
Hermann Gausepohl, Mutterstadt, DE;
Wolfgang Fischer, Ludwigshafen, DE;
Wolfgang Loth, Bad Durkheim, DE;
Reiner Thiele, Kaiserslautern, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
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.