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:
Apr. 27, 2010
Filed:
Dec. 20, 2005
Hermann Kauth, Krefeld, DE;
Wolfgang Ebert, Krefeld, DE;
Wilfried Haese, Odenthal, DE;
Helmut Einberger, Odenthal, DE;
Alexander Meyer, Düsseldorf, DE;
Andreas Frankenau, Kempen, DE;
Uli Franz, Erkrath, DE;
Christian Eh, Chonburi, TH;
Stefaan DE Vos, Rayong, TH;
Bert Ruytinx, Halen, BE;
Hermann Kauth, Krefeld, DE;
Wolfgang Ebert, Krefeld, DE;
Wilfried Haese, Odenthal, DE;
Helmut Einberger, Odenthal, DE;
Alexander Meyer, Düsseldorf, DE;
Andreas Frankenau, Kempen, DE;
Uli Franz, Erkrath, DE;
Christian Eh, Chonburi, TH;
Stefaan De Vos, Rayong, TH;
Bert Ruytinx, Halen, BE;
Bayer MaterialScience AG, Leverkusen, DE;
Abstract
An improvement to the phase interface process of preparing aromatic polycarbonate is disclosed. The process is characterized in that the phosgenation is carried out at 0 to 40° C., and in that the temperature of the reaction mixture at the time of addition of the catalyst at 10 to 40° C., and in that the molar ratio of aromatic dihydroxy compounds to phosgene at 1:1.05 to 1:1.20. The polycarbonate thus produced is characterized in its low content of carbamates, making it particularly suitable for the preparation of optical storage media.