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:
Apr. 21, 2009
Filed:
Jun. 12, 2006
Venugopal Boddapaty Venkata, Bangalore, IN;
Gurram Kishan, Bangalore, IN;
Jan Pleun Lens, Breda, NL;
Daniel Francis Lowery, Schenectady, NY (US);
Mahesh Malusare, Bangalore, IN;
Patrick Joseph Mccloskey, Watervliet, NY (US);
Manisha Potdar, Bangalore, IN;
Venugopal Boddapaty Venkata, Bangalore, IN;
Gurram Kishan, Bangalore, IN;
Jan Pleun Lens, Breda, NL;
Daniel Francis Lowery, Schenectady, NY (US);
Mahesh Malusare, Bangalore, IN;
Patrick Joseph McCloskey, Watervliet, NY (US);
Manisha Potdar, Bangalore, IN;
SABIC Innovative Plastics IP B.V., Bergen op Zoom, NL;
Abstract
A method of producing a polycarbonate, the method comprising: polymerizing a dihydric phenol and a carbonate precursor in the presence of oxalic acid to produce a polycarbonate with a yellowness index of less than or equal to 10 measured in accordance with ASTM E313 test method on molded samples having a thickness of about 2.5 millimeters; wherein the amount of oxalic acid ranges from about 20 parts per million to about 350 parts per million, relative to an amount of the dihydric phenol; wherein the dihydric phenol is represented by Formula (I): wherein R is a hydrogen atom or an aliphatic functionality having 1 to 6 carbon atoms; and n is an integer having a value of 1 to 4.