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US 5,399,784 AGranted
Process for the production of bisphenol A
AssigneeChiyoda Corporation
InventorsSachio Asaoka, Noriyuki Yoneda, Kouji Sakashita, Tetsuo Maejima, Makoto Yasui, Akio Shindo
Life of this patent
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Abstract
A high quality bisphenol A with a high purity and an excellent hue is produced from a crystalline adduct of bisphenol A and phenol by washing the adduct with specifically purified phenol, followed by decomposition of the washed adduct to separate bisphenol A. The purification is performed by a method including contacting raw material phenol with a strong-acid ion exchange resin to obtain treated phenol, and distilling the treated phenol.
Claims3
A process for the production of bisphenol A, comprising the steps of:
- (a) reacting acetone with a stoichiometrically excess amount of phenol to obtain a bisphenol A-containing product;
- (b) crystallizing said product to obtain a crystalline adduct of bisphenol A and phenol;
- (c) providing raw material phenol which contains an impurity convertible to a high boiling point material having a boiling point of higher than 185.degree. C. upon being heated at a temperature higher than the melting point of phenol;
- (d) contacting said raw material phenol with a gel-type sulfonic acid-type cation exchange resin having a degree of cross-linking of 10% by weight or less at a temperature and for a period of time sufficient to convert at least part of said impurity into said high boiling point material and to obtain treated phenol;
- (e) distilling said treated phenol at a temperature of 185.degree. C. or less to separate purified phenol, as distillate, from said high boiling point material;
- (f) washing said adduct with said purified phenol;
- and
- (g) decomposing said washed adduct to obtain bisphenol A.
5 more elements
Dependencies are inferred from the claim text.