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.

Date of Patent:
Sep. 28, 1993

Filed:

Aug. 20, 1992
Applicant:
Inventors:

Jurgen Kirsch, Leverkusen, DE;

Gunther Weymans, Leverkusen, DE;

Dieter Freitag, Krefeld, DE;

Assignee:

Bayer Aktiengesellschaft, Leverkusen, DE;

Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ; C08G / ;
U.S. Cl.
CPC ...
528490 ; 528196 ; 528483 ; 528491 ;
Abstract

A process for isolating a poly(ester)carbonate resin from its methylene chloride solution is disclosed. The process entails combining a solution which contains 5 to 30% by weight resin with carbon dioxide fluid in a two-component nozzle under pressures of 90 to 180 bar and at temperatures of 50.degree. to 75.degree. C., while maintaining in said the two-component nozzle a back-pressure of 85 to 150 bar, and introducing the resin into a separation vessel with retention of dust particles. Importantly, the relative quantities of carbon dioxide fluid and polymer solution used in the two-component nozzle are between 10 and 3 parts carbon dioxide fluid per one part of polymer solution, and the carbon dioxide fluid contains 10 to 1000 ppm methylene chloride. The process avoids blockage of said nozzle.


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