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:
Oct. 13, 1998
Filed:
May. 05, 1997
Daniel Joseph Brunelle, Burnt Hills, NY (US);
Peter David Phelps, Schenectady, NY (US);
Eugene Pauling Boden, Scotia, NY (US);
Mark Erik Nelson, Mt. Vernon, IN (US);
Larry Ivis Flowers, Evansville, IN (US);
Paul Dean Sybert, Evansville, IN (US);
Erik Hendrick Capelle, Oud Vossemeer, NL;
General Electric Company, Schenectady, NY (US);
Abstract
Diaminoalkyl quaternary ammonium salts are prepared by the reaction of alkyl halides with tertiary diamines having C.sub.2-20 primary alkyl radicals attached to nitrogen and an alkyl radical between the two nitrogen atoms in which at least three carbon atoms separate said nitrogen atoms. Said salts are preferably substantially free from corresponding diamines. They are useful as catalysts for interfacial polycarbonate preparation by the reaction of phosgene with at least one dihydroxyaromatic compound. Polycarbonate preparation using such catalysts is economical in phosgene consumption, is accompanied by a rapid conversion of chloroformate groups to desirable species and affords a product with a very low proportion of unreacted dihydroxyaromatic compound.