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:
Aug. 08, 1995
Filed:
Apr. 04, 1994
Hans-Josef Buysch, Krefeld, DE;
Norbert Schon, Krefeld, DE;
Steffen Kuhling, Meerbusch, DE;
Heinrich Hahnsen, Duisburg, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
A continuous process for splitting an aromatic polycarbonate resin is disclosed. Accordingly there are reacted in a distillation column and in the presence of a catalyst (i) a polycarbonate resin in solution with (ii) methanol to produce a dihydroxy compound and dimethyl carbonate. The solution which contains polycarbonate and monohydroxy compound solvent exclusive of methanol is fed into the upper section of said column and the methanol is fed into the lower section of the column. The methanol is fed in the form of a mixture containing methanol and about 1-50 weight percent of dimethyl carbonate. The dimethyl carbonate thus produced is removed from an upper section of the column and the dihydroxy compound is removed from a lower section of the column.