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:
Feb. 21, 1995
Filed:
Jun. 14, 1993
Applicant:
Inventors:
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
558265 ; 558266 ; 558267 ; 558268 ; 558269 ; 558277 ;
Abstract
A process is disclosed for cleaving polycarbonates into bisphenols and diaryl carbonates by transesterifying with phenols in the presence of catalysts. The process entails isolating bisphenols from the product of the transesterification, and subjecting the remaining mixture which contains phenols and diaryl carbonates to flash distillation. The phenols and diaryl carbonates are distilled off and separated, and the diaryl carbonates are recovered.