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. 23, 1999
Filed:
Dec. 20, 1996
Godavarthi Satyanarayana Varadarajan, Niskayuna, NY (US);
Tomoaki Shimoda, Moka, JP;
Akio Kanezawa, Sodegaura, JP;
Satoru Minami, Ichihara, JP;
General Electric Company, Schenectady, NY (US);
Abstract
A method for determining the effective level of catalyst for the preparation of a polycarbonate polymer by a transesterification reaction is disclosed. The method involves measurement of the leaving group by-product (usually phenol) produced in a test reaction between an aromatic dihydroxy compound and a carbonic acid diester, in the presence of a known amount of transesterification catalyst. The by-product production values can be compared with by-product reference values to calculate the effective level of catalyst. This data can be used to efficiently control catalytic activity in a production scale reaction for producing polycarbonate polymer.