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:
Dec. 09, 1997
Filed:
Apr. 06, 1995
Claus Wulff, Krefeld, DE;
Kaspar Hallenberger, Leverkusen, DE;
Heinrich Steude, Leverkusen, DE;
Kurt-Peter Meurer, Antwerp, BE;
Tony van Osselaer, St.-Niklaas/Belsele, BE;
Jurgen Hinz, Brasschaat, BE;
Frank Quaeyhaegens, Mortsel, BE;
Johan Vaes, Kaltmhout, BE;
Ignace Hooftman, Kruibeke, BE;
Bayer AG, Leverkusen, DE;
Abstract
The invention relates to a method for the purification by distillation of p,p-bisphenol A from the melt. The p,p-bisphenol A melt thus obtained is highly heat-stable, stable in storage and colour-stable, is free from high-boiling components and no longer contains any surface-active or non-distillable metal, salt, acid or polymer components and no sulphur-containing components; o,p-BPA and phenol are removed and the low-boiling components are scarcely detectable.