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. 22, 2005
Filed:
Dec. 23, 2002
Patrick Joseph Mccloskey, Watervliet, NY (US);
Jan Pleun Lens, Breda, NL;
James Anthony Cella, Clifton Park, NY (US);
Jan Henk Kamps, Bergen op Zoom, NL;
Kathryn Lynn Longley, Saratoga Springs, NY (US);
Narayan Ramesh, Niskayuna, NY (US);
Warren William Reilly, Northville, NY (US);
Paul Michael Smigelski, Jr., Schenectady, NY (US);
Marc Brian Wisnudel, Clifton Park, NY (US);
Patrick Joseph McCloskey, Watervliet, NY (US);
Jan Pleun Lens, Breda, NL;
James Anthony Cella, Clifton Park, NY (US);
Jan Henk Kamps, Bergen op Zoom, NL;
Kathryn Lynn Longley, Saratoga Springs, NY (US);
Narayan Ramesh, Niskayuna, NY (US);
Warren William Reilly, Northville, NY (US);
Paul Michael Smigelski, Jr., Schenectady, NY (US);
Marc Brian Wisnudel, Clifton Park, NY (US);
General Electric Company, Niskayuna, NY (US);
Abstract
Polycarbonates containing low or undetectable levels of Fries rearrangement products and comprising repeat units derived from one or more of resorcinol, hydroquinone, methylhydroquinone, bisphenol A, and 4,4'-biphenol have been prepared by the melt reaction of one or more of the aforementioned dihydroxy aromatic compounds with an ester-substituted diaryl carbonate such as bis-methyl salicyl carbonate. Low, or in many instances undetectable, levels of Fries rearrangement products are found in the product polycarbonates obtained as the combined result of a highly effective catalyst system which suppresses the Fries reaction and the use of lower melt polymerization temperatures relative to temperatures required for the analogous polymerization reactions using diphenyl carbonate.