Patent ID: 6858758
Filing Date: 2005-02-22
Classification: C07C

Abstract:
1. A method for producing a bisphenol comprising reacting in a reactor a reaction mixture that contains at least one first reactant selected from a first group consisting of phenol and substituted phenols with at least one second reactant selected from a second group consisting of acetone, butanone, 2-pentanone, 3-pentanone, cyclopentanone, 3-alkylcyclopentanone with an alkyl radical containing 1 to 12 carbon atoms, 3,3-dialkylcyclopentanone with an alkyl radical containing 1 to 12 carbon atoms wherein the alkyl radicals may be identical or different, 3,3,5-trialkylcyclohexanone, wherein the alkyl radicals have 1 to 12 carbon atoms and may be identical or different, cyclohexanone, 3-alkylcyclohexanone with an alkyl radical containing 1 to 12 carbon atoms, 4-alkylcyclohexanone with an alkyl radical containing 1 to 12 carbon atoms, 3,3-dialkylcyclohexanone with alkyl radicals containing 1 to 12 carbon atoms, wherein the alkyl radicals may be identical or different, and acetophenone in the presence of hydrogen chloride catalyst and volatile sulphur compound having an SH bond as co-catalyst to obtain a mixture that contains bisphenol , first reactant and second reactant, and separating from the mixture the catalyst and co-catalyst and water of reaction, by distillation to obtain a product containing bisphenol, phenol and crystallizing the product to obtain bisphenol/phenol adduct and then purifying the adduct to exclude phenol by water wash or thermal desorption while blowing in nitrogen to obtain the bisphenol.