Patent Number: 6,294,702

Title: Method for continuous production of dihydroxydiphenylalkanes

Abstract: The present invention relates to a process for the continuous production of dihydroxydiphenylalkanes (bisphenols) by the reaction of fresh phenol, and of phenol obtained from the cracking of by-products, with isoalkenylphenol and ketone. In the course of this process, the reaction mixture is worked up by distillation and a high purity bisphenol is produced. The bottom products and distillates containing the by-products are cracked under basic conditions and optionally thereafter under acidic conditions. The cracked products, which substantially consist of isoalkenylphenol and phenol, are recycled, optionally after purification, with the phenol obtained during the purification of bisphenol, to the reaction to form bisphenol, and the residue obtained from cracking is disposed of.

Inventors: Fennhof; Gerhard (Willich, DE), Buysch; Hans-Josef (Krefeld, DE), Fengler; Gerd (Krefeld, DE), van Osselaer; Tony (Krefeld, DE)

Assignee: Bayer Aktiengesellschaft

International Classification: C07C 37/00 (20060101); C07C 37/20 (20060101); C07C 39/04 (20060101); C07C 39/00 (20060101); C07C 039/12 ()

Expiration Date: 09/25/2018