Abstract: Bisphenol-A is purified in a process which comprises the following steps: a) cooling a liquid mixture comprising bisphenol-A and water in a bisphenol-A crystallizer to form bisphenol-A crystals in a liquid phase; b) separating the bisphenol-A crystals from the liquid phase; c) dividing at least a portion of the liquid phase into a bisphenol-rich organic phase and a water-rich phase; d) feeding phenol and at least a portion of the bisphenol-rich organic phase into a adduct crystallizer to form a crystalline adduct of phenol and bisphenol-A in a mother liquor, and e) separating the crystalline adduct from the mother liquor. Bisphenol-A of high purity at a high yield is obtained.

Abstract: A strong-acid cation exchange resin in acid form is contacted with an alkylcarhamoyl alkylthioester in the presence of water for producing a strong-acid cation exchange resin comprising a plurality of acid groups being partially neutralized with a mercaptoalkylamine. The produced partially neutralized cation exchange resin is useful as a catalyst in a process of producing a bisphienol by reaction of a phenolic compound with a carhonyl compound.

Abstract: A strong-acid cation exchange resin in acid form is contacted with an alkylcarbamoyl alkylthioester in the presence of water for producing a strong-acid cation exchange resin comprising a plurality of acid groups being partially neutralized with a mercaptoalkylamine. The produced partially neutralized cation exchange resin is useful as a catalyst in a process of producing a bisphenol by reaction of a phenolic compound with a carbonyl compound.