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. 04, 1994
Filed:
Sep. 01, 1992
Claus Wulff, Krefeld, DE;
Reinhard Schomacker, Leverkusen, DE;
Jurgen Kadelka, Krefeld, DE;
Jurgen Heuser, Krefeld, DE;
Gunther Weymans, Leverkusen, DE;
Konrad Hable, Leverkusen, DE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
The invention relates to ultrafine suspensions of bisphenol, sodium hydroxide and water for the production of polycarbonates by the two-phase interfacial process. According to the invention, these suspensions are prepared by cooling bisphenolate concentrations near the solubility limit in aqueous sodium hydroxide with intensive mixing at relatively high temperatures and precipitating bisphenolate or more bisphenolate in the form of fine droplets during the cooling process. The ultrafine suspensions provide for a high volume/time yield in the interfacial reaction.