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:
Feb. 27, 2007
Filed:
Nov. 01, 2004
Gerardo Hidalgo, Cartagena Murcia, ES;
Patrick J. Mccloskey, Watervliet, NY (US);
Alberto Nisoli, Niskayuna, NY (US);
Lina Prada, Murcia, ES;
Gerardo Hidalgo, Cartagena Murcia, ES;
Patrick J. McCloskey, Watervliet, NY (US);
Alberto Nisoli, Niskayuna, NY (US);
Lina Prada, Murcia, ES;
General Electric Company, Schenectady, NY (US);
Abstract
A method of making polycarbonate comprises melt-polymerizing an aromatic dihydroxy compound and a carbonic acid diester in a presence of a polymerization catalyst in a reactor system producing a byproduct stream, wherein the polymerization catalyst comprises a quaternary phosphonium compound; and purifying the byproduct stream to separate the carbonic acid diester, wherein the separated carbonic acid diester has a phosphorous concentration of less than or equal to about 30 parts per million.