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:
Dec. 07, 2010
Filed:
Mar. 05, 2009
Wolfgang Ebert, Krefeld, DE;
Christian Kords, Krefeld, DE;
Rolf Bachmann, Bergisch Gladbach, DE;
Lars Obendorf, Leichlingen, DE;
Johan Vanden Eynde, Zwijnaarde, BE;
Bert Ruytinx, Halen, BE;
Johann Seeba, Leverkusen, DE;
Wolfgang Ebert, Krefeld, DE;
Christian Kords, Krefeld, DE;
Rolf Bachmann, Bergisch Gladbach, DE;
Lars Obendorf, Leichlingen, DE;
Johan Vanden Eynde, Zwijnaarde, BE;
Bert Ruytinx, Halen, BE;
Johann Seeba, Leverkusen, DE;
Bayer MaterialScience AG, Leverkusen, DE;
Abstract
Continuous processes for preparing polycarbonates having a weight average molecular weight M, of 15,000 to 200,000 g/mol, the processes comprising reacting a dihydroxydiarylalkane and phosgene in the presence of a catalyst in a phase boundary process comprising: continuously dispersing in a disperser an organic phase comprising at least a portion of the phosgene and a solvent suitable for the polycarbonate and an aqueous phase comprising the dihydroxydiarylalkane, water and an alkali solution present in an amount of 1.5 to 2.5 moles per mole of the dihydroxydiarylalkane, to form a mixture; reacting the mixture in a first reactor with a residence time of less than 0.5 seconds; further reacting the mixture in a second reactor with addition of further alkali solution and, optionally, a chain terminator; and effecting further condensation in a third reactor with addition of further alkali solution and, optionally, a chain terminator, in the presence of the catalyst.