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. 25, 2008
Filed:
Oct. 28, 2005
Subarna Shyamroy, West Bengal, IN;
Gokul Srinivasan, Bangalore, IN;
Subarna Shyamroy, West Bengal, IN;
Gokul Srinivasan, Bangalore, IN;
General Electric Company, Schenectady, NY (US);
Abstract
A method for producing a transparent article is provided. The method comprises melt transesterifying in the presence of a transesterification catalyst and a monomer mixture to produce a biphenol polycarbonate copolymer product comprising greater than 45 mole percent of structural units derived from the biphenol by heating the monomer mixture to a temperature of greater than 340° C. to make the biphenol polycarbonate copolymer; and cooling the biphenol polycarbonate copolymer to produce the transparent article. The monomer mixture comprises the biphenol, at least one aromatic dihydroxy compound other than the biphenol, and an activated carbonic acid diester.