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:
Apr. 20, 2004
Filed:
Aug. 26, 2002
Frieder Heydenreich, Düsseldorf, DE;
Michael Prein, Brasschaat, BE;
Michael Bödiger, League City, TX (US);
Rainer Neumann, Krefeld, DE;
Gerhard Fennhoff, Willich, DE;
Johan Vaes, Kalmthout, BE;
Bayer Aktiengesellschaft, Leverkusen, DE;
Abstract
A process for the production of 2,2-bis(4-hydroxyphenyl)propane (BPA) is disclosed. The process that entails reacting acetone with phenol in the presence of cross-linked sulfonated polystyrene resins is characterised in that BPA is separated from the reaction solution downstream of the reaction unit by means of a multi-stage vacuum distillation and a subsequent single- or multi-stage layer crystallisation. The by-product stream with accumulated by-products is returned downstream of the reaction unit.