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:
Mar. 03, 2009
Filed:
May. 31, 2006
Paul William Buckley, Scotia, NY (US);
David Michael Dardaris, Ballston Spa, NY (US);
Patrick Joseph Mccloskey, Watervliet, NY (US);
Paul William Buckley, Scotia, NY (US);
David Michael Dardaris, Ballston Spa, NY (US);
Patrick Joseph McCloskey, Watervliet, NY (US);
Sabic Innovative Plastics IP B.V., Bergen op Zoom, NL;
Abstract
An improved method for the preparation of ester-substituted diaryl carbonates prepared by reacting phosgene with recycle streams of ester-substituted phenols from reaction processes using a tetraalkyl ammonium hydroxide catalyst, a tetraalkyl phosphonium hydroxide catalyst, or both, where at least one alkyl group of the tetraalkyl ammonium hydroxide or the tetraalkyl phosphonium hydroxide is a methyl group. The improvement includes the step of treating the recycle stream to reduce the concentration of a trialkyl amine, trialkyl phosphine, or both, if present, from the recycle stream prior to reacting it with phosgene to form the ester-substituted diaryl carbonate.