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:
Sep. 21, 2010
Filed:
Dec. 20, 2005
Alexander Meyer, Düsseldorf, DE;
Helmut Einberger, Odenthal, DE;
Wolfgang Ebert, Krefeld, DE;
Michael Prein, Krefeld, DE;
Wilfried Haese, Odenthal, DE;
Uli Franz, Erkrath, DE;
Stephan Konrad, Dormagen, DE;
Alexander Meyer, Düsseldorf, DE;
Helmut Einberger, Odenthal, DE;
Wolfgang Ebert, Krefeld, DE;
Michael Prein, Krefeld, DE;
Wilfried Haese, Odenthal, DE;
Uli Franz, Erkrath, DE;
Stephan Konrad, Dormagen, DE;
Bayer Materialscience AG, Leverkusen, DE;
Abstract
The present invention provides a polycarbonate resin produced by the continuous interfacial process characterized in that after alkaline hydrolysis with sodium hydroxide, the polycarbonate resin contains an amount of 0.01 to 150 ppm of carbamate compounds according to formula (1) said amount measured by high pressure liquid chromatography, wherein Rand Rindependently of one another denote hydrogen or C-C-alkyl, or together denote C-C-alkylidene, and Rand Rindependently of one another denote hydrogen. C-C-alkyl or phenyl, or together with the carbon atom to which they are bonded form cyclohexyl or trimethylcyclohexyl, the process comprising phosgene reacting with at least one bisphenol at 8 to 17% molar excess of phosgene relative to the bisphenol.