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:
Jan. 15, 2002
Filed:
Oct. 14, 1999
Henricus Hubertus Maria van Hout, Halsteren, NL;
Akio Ikeda, Ichihara, JP;
Takato Kimura, Ichihara, JP;
Patrick Joseph McCloskey, Watervliet, NY (US);
Tomoaki Shimoda, Ichihara, JP;
General Electric Company, Schenectady, NY (US);
Abstract
The manufacture of polycarbonates can be accomplished via an ester interchange reaction of a dihydroxy compound and a carbonic acid diester. The method, which can be a single or multi-stage process wherein the total amount of alkali metal compounds and alkaline earth metal compounds contained as impurities is 1×10 moles or less per mole of dihydroxy compound used as raw materials, and the catalyst employed is an ammonium and/or phosphonium compound, a compound which decomposes or volatilizes at a temperature of 100 to 300° C., and/or an alkali metal phosphorous containing inorganic salt and/or alkaline earth metal phosphorous-containing inorganic salt.