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Process for preparing a bisphenol

  • US 5,288,926 A
  • Filed: 02/04/1993
  • Issued: 02/22/1994
  • Est. Priority Date: 03/02/1992
  • Status: Expired due to Term
First Claim
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1. A process of preparing a bisphenol comprising the steps of:

  • a) reacting a phenolic compound selected from the group consisting of phenol, cresols, xylenols, chlorophenols, thymol, carvacrol, cumenol, 2-methyl-6-ethylphenol, 2,4-dimethyl-3-ethylphenol, 4-ethylphenol, 2-ethyl-4-methylphenol, 2,3,6-trimethylphenol, 2-methyl-4-tertiary-butylphenol, 2,4-ditertiary-butyl-phenol, 4-methyl-2-tertiary-butylphenol, 2-teritary-butyl-4-methylphenol, 2,3,5,6-tetramethylphenol, 2,6-dimethylphenol, 2,6- ditertiary-butylphenol, 3,5-dimethylphenol, 3,5-diethylphenol, 2-methyl-3,5-diethylphenol, o-phenylphenol, p-phenylphenol, tetraphenolethane, the naphthols and phenanthrol with a carbonyl compound having the formula;

    ##STR3## wherein R1 is selected from the group consisting of aliphatic, cycloaliphatic and aromatic radicals, and R2 is selected from the group consisting of aliphatic, cycloaliphatic, aromatic radicals and hydrogen in a reaction mixture, containing said carbonyl compound, a stoichiometric excess of said phenolic compound and a strongly acidic ion exchange resin catalyst, to produce a product mixture containing a bisphenol;

    b) separating bisphenol from the product mixture to leave a motor liquor; and

    c) recycling at least a portion of the mother liquor to the reaction mixture,wherein at least one of the following steps is conducted;

    i) 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 reaction step a);

    ii) at least a portion of the product mixture 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;

    oriii) at least a portion of 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.

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