Patent Number: 6,307,111

Title: Method for continuous production of dihydroxydiarylalkanes

Abstract: The present invention relates to a process for the continuous production of dihydroxydiarylalkanes (bisphenols) by the reaction of fresh phenol, phenol and isoalkenylphenol from the decomposition of by-products, and ketone. In this process the bulk of the bisphenol is recovered from the reaction mixture by crystallization and the mother liquor obtained is freed from phenol by distillation. The phenol is returned to the reaction and the bottoms obtained during the distillation are decomposed in a reactive rectification after addition of a basic catalyst. The phenol and isoalkenylphenol leaving at the top are led back into the reaction; the bottoms from the first reactive column are acidified and in a second reactive rectification, in the presence of an acid catalyst, are further decomposed into phenol, which distils off and is reused in the reaction, and bottoms, which are disposed of.

Inventors: Fennhoff; Gerhard (Willich, DE), Buysch; Hans-Josef (Krefeld, DE), Fengler; Gerd (Krefeld, DE)

Assignee: Bayer Aktiengesellschaft

International Classification: C07C 37/00 (20060101); C07C 39/16 (20060101); C07C 37/20 (20060101); C07C 39/00 (20060101); C07C 039/16 ()

Expiration Date: 10/23/2018