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.

Abstract: Bisphenols are prepared bya) reacting a phenolic compound with a carbonyl compound in a reaction mixture, containing the carbonyl compound, a stoichiometric excess of the phenolic compound and a catalyst, to produce a product mixture containing a bisphenol,b) separating bisphenol from the product mixture to leave a mother liquor andc) recycling at least a portion of the mother liquor to the reaction mixture.At least a portion of the phenolic compound is contacted with a strongly acidic cation exchange resin and a strongly basic anion exchange resin before the phenolic compound is used in the reaction step a) and/or at least a portion of the product mixture and/or at least a portion or the mother liquor is contacted with a strongly acidic cation exchange resin and a strongly basic anion exchange resin before mother liquor is recycled to the reaction mixture.