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:
Jul. 16, 2013
Filed:
Apr. 07, 2011
Stephan Konrad, Dormagen, DE;
Helmut-werner Heuer, Krefeld, DE;
Karl-heinz Köhler, Aachen-Brand, DE;
Christian Münnich, Leverkusen, DE;
Rolf Wehrmann, Krefeld, DE;
Stephan Konrad, Dormagen, DE;
Helmut-Werner Heuer, Krefeld, DE;
Karl-Heinz Köhler, Aachen-Brand, DE;
Christian Münnich, Leverkusen, DE;
Rolf Wehrmann, Krefeld, DE;
Bayer Material Science AG, Monheim, DE;
Abstract
The present invention relates to an aromatic branched polycarbonate, produced via melt transesterification of a bisphenol with a diaryl carbonate in the presence of a branching agent, wherein the aromatic branched polycarbonate comprises branching point structures and structures of formula (D) wherein X is a single bond, C1- to C6-alkylene, C2- to C5-alkylidene or C5- to C6-cycloalkylidene, optionally substituted by C1- to C6-alkyl; wherein the amount of D in the aromatic branched polycarbonate is in the range of from 5 to 450 mg per kg of the aromatic branched polycarbonate; and wherein the ratio of the total branching point structures to the total structures of the formula D in the aromatic branched polycarbonate is in the range of from 8 to 200.