Process for purifying a bisphenol

Abstract

A process for the purification of a crude bisphenol comprises the following steps: (1) preparing a mixture comprising from about 35 to about 70% of a crude bisphenol and from about 65 to about 30% of water, by the total weight of bisphenol and water, without addition of a substantial amount of an organic solvent or an alkaline compound, at a pressure above atmospheric and a temperature above about 100.degree. C., (2) crystallizing bisphenol at a pressure below atmospheric, (3) separating crystalline bisphenol from the mother liquor, (4) dividing at least a portion of the mother liquor into a bisphenol-rich oil phase and a water-rich phase, (5) preparing a mixture comprising at least a portion of the bisphenol-rich oil phase, water and optionally an additional amount of crude bisphenol at a pressure above atmospheric and a temperature above about 100.degree. C., (6) cooling the mixture and crystallizing bisphenol; and (7) separating crystalline bisphenol from the mother liquor.

Dependencies are inferred from the claim text.