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:
Oct. 17, 2006
Filed:
Dec. 20, 2002
Rudy Francois Alain Jos Peemans, Erps-Kwerps, BE;
Eugène Theodorus Wilhelmus Maria Schipper, Haarlem, NL;
Hendricus Franciscus Zirkzee, Schore, NL;
Jan Henk Kamps, Bergen op Zoom, NL;
Rudy Francois Alain Jos Peemans, Erps-Kwerps, BE;
Eugène Theodorus Wilhelmus Maria Schipper, Haarlem, NL;
Hendricus Franciscus Zirkzee, Schore, NL;
Jan Henk Kamps, Bergen op Zoom, NL;
General Electric Company, Schenectady, NY (US);
Abstract
A method for the manufacture of a polycarbonate which comprises reacting a carbonate precursor with a dihydroxy compound in the presence of an aqueous base in an inert organic solvent optionally containing a molecular weight regulator to form an oligomeric polycarbonate, wherein the reaction between the dihydroxy compound and the carbonate precursor is about 80 to about 99% completed; removing the inert organic solvent and the aqueous base to isolate the oligomeric polycarbonate; and transesterifying the isolated oligomeric polycarbonate to form a polymeric polycarbonate at a temperature and pressure effective to remove trace amounts of residual solvent. This method eliminates some of the problems of the prior art such as the removal of solvent from high molecular weight polycarbonate, which is both cumbersome, energy intensive and expensive.