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:
Nov. 02, 1993
Filed:
Jun. 19, 1992
Reinhard Schomacker, Leverkusen, DE;
Uwe Hucks, Alpen, DE;
Gunther Weymans, Leverkusen, DE;
Wolfgang Herrig, Bergisch Gladbach, DE;
Jurgen Kirsch, Leverkusen, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
A process for the continuous production of a thermoplastic aromatic polycarbonate is disclosed. Accordingly, in a reactor system which includes a tube reactor and a tank equipped with a stirrer, there are reacted a preheated dialkali diphenolate aqueous solution with gaseous phosgene in CH.sub.2 Cl.sub.2 and/or in chlorobenzene solution containing excess phosgene, in a mixer to form a mixed emulsion. The emulsion is then transported at least partly against the force of gravity into the tube reactor to facilitate a polycondensation reaction and in which after a residence time of at least 10 seconds and without dissipation of the heat of reaction there is added a chain terminator. The heat of reaction is dissipated in said tank and aqueous sodium hydroxide and catalyst are added to complete the reaction. The process according to the invention leads to high yields of phosgene.