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Production of low-particulate bisphenol and use thereof in the manufacturing of polycarbonate

  • US 6,545,187 B1
  • Filed: 09/19/2001
  • Issued: 04/08/2003
  • Est. Priority Date: 09/19/2001
  • Status: Expired due to Term
First Claim
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1. A method of producing a low-particulate dihydric aromatic compound, comprising the steps of:

  • (a) introducing into a desorber column possessing a non-aggregate packing material an adduct of a dihydric aromatic compound and phenol;

    (b) providing an operating temperature range in the desorber column that is sufficiently high and an operating pressure in the column that is sufficiently low such that the adduct is distilled;

    (c) discharging from the desorber column a first stream containing substantially all of the phenol; and

    (d) discharging from the desorber column a second stream containing substantially all of the dihydric aromatic compound;

    whereby the second stream is substantially free of particulate matter added in the desorber column.

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