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Process for preparing high-purity bisphenol A

  • US 4,954,661 A
  • Filed: 03/09/1989
  • Issued: 09/04/1990
  • Est. Priority Date: 03/11/1988
  • Status: Expired due to Term
First Claim
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1. A method for preparing high-purity bisphenol A comprising a principal process which comprises the steps of (1) reacting phenol with acetone at a temperature of 40 to 90°

  • C. of an acid catalyst which catalyzes the reaction of phenol and acetone to form bisphenol A to obtain a first reaction solution, (2) removing a part of the phenol and/or the catalyst and water from the first reaction solution to form a first concentration adjusted solution, (3) cooling the first concentration adjusted solution to obtain a first slurry containing an adduct of bisphenol A with phenol, (4) subjecting the first slurry to solid-liquid separation to form primary crystals and a first mother liquor and (5) removing phenol from the first crystal to obtain bisphenol A; and

    a sub-process which comprises the steps of (6) reacting p-isopropenylphenol with phenol in the presence of an acid catalyst to form a second reaction solution, (7) removing a part of the phenol and/or the catalyst and water from the second reaction solution to form a second concentration adjusted solution, (8) cooling the second concentration adjusted solution to obtain a second slurry, (9) subjecting the second slurry to solid-liquid separation to obtain secondary crystals and a second mother liquor and (10) treating the second mother liquor to obtain p-isopropenylphenol and phenol, the first mother liquor from the principal process being fed to the sub-process and the secondary crystals from the sub-process being fed to the principal process.

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