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:
Oct. 23, 2001
Filed:
Dec. 14, 1999
Applicant:
Inventors:
Assignee:
Bayer Aktiengesellschaft, Leverkusen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G 6/400 ;
U.S. Cl.
CPC ...
C08G 6/400 ;
Abstract
A process of producing branched polycarbonates by melt transesterification from at least one diphenol, diaryl carbonate and a branching agent, and in the optional presence of a catalyst is disclosed. The process which is carried out at temperatures between 80 to 400° C. and at pressures between 1 and 0.01 mbar, entails using as branching agent at least one member selected from the group consisting of (i) a specifically structured aliphatic alcohol and (ii) the ether of (i) which is formed by self-condensation.