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. 21, 1995
Filed:
Oct. 26, 1993
Henricus H van Hout, Halsteren, NL;
Christianus J Maas, Rilland, NL;
Laurus van der Wekke, Goes, NL;
Martin H Oyevaar, Goes, NL;
General Electric Company, , NY (US);
Abstract
The invention relates to a method of preparing a compound of formula 1 ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 correspond to H, a branched or non-branched, optionally substituted alkyl group, or an optionally substituted aryl group, suitable as a chain stopper in the preparation of an aromatic polycarbonate, by reaction of a compound of formula 2 ##STR2## wherein R.sub.1, R.sub.2 and R.sub.3 have the meanings described hereinbefore, with phosgene, comprising the continuous supply of the compound of formula 2 and phosgene to a solution of phosgene in a solvent, the temperature being kept at a value between 0.degree. and 15.degree. C. and the pH being kept at a value between 1 and 6.