Abstract: A process for recovering a solid adduct of a bis(4-hydroxyaryl)alkane and a phenolic compound from a suspension comprising the addict is disclosed. The process comprises the steps of a) supplying the suspension to a rotary filter, b) filtering the supplied suspension in the rotary filter to retain adduct as an adduct cake, c) pre-drying the adduct cake with an inert gas, d) washing the pre-dried adduct cake, e) optionally drying the washed adduct cake, and f) discharging the washed adduct cake from the rotary filter.

Abstract: A process for recovering a solid adduct of a bis(4-hydroxyaryl)alkane and a phenolic compound from a suspension comprising the addict is disclosed. The process comprises the steps of a) supplying the suspension to a rotary filter, b) filtering the supplied suspension in the rotary filter to retain adduct as an adduct cake, c) pre-drying the adduct cake with an inert gas, d) washing the pre-dried adduct cake, e) optionally drying the washed adduct cake, and f) discharging the washed adduct cake from the rotary filter.

Abstract: A process for preparing an adduct of a bisphenol with a phenolic compound comprising the following steps:a) reacting a carbonyl compound with a stoichiometric excess of a phenolic compound in the presence of an acidic cation exchange resin as a catalyst, to produce a product mixture containing a bisphenol, unreacted phenolic compound, unreacted carbonyl compound and water, andb) crystallizing an adduct of the bisphenol with the phenolic compound from the product mixture in a crystallization device in the presence of water and acetone.The product mixture obtained in step a) is not subjected to a distillation step before the product mixture enters the crystallization device and prior to the crystallization step b) the content of the carbonyl compound in the product mixture is controlled and, if necessary, carbonyl compound is added such that the total concentration of the carbonyl compound is from about 0.1 to about 8 percent, based on the total weight of the product mixture.

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.