Process for preparing 2,2-bis(4-hydroxy-phenyl) propane from distillation by-products thereof

• US 4,188,496 A
• Filed: 12/23/1977
• Issued: 02/12/1980
• Est. Priority Date: 12/23/1977
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Jaquiss, Donald B. G., Mitchell, Lawrence C.
• Primary Examiner(s): Morgenstern, Norman
• Application Number:
  US05/863,667
• Time in Patent Office: 781 Days
• Field of Search: 568/724, 568/728, 568/723
• US Class Current: 568/723
• CPC Class Codes: C07C 37/00 Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
• CPC Class Codes: C07C 37/48 by exchange of hydrocarbon groups, which may be substituted, from the same of other compounds, e.g. transalkylation
• CPC Class Codes: C07C 39/16 Bis-(hydroxyphenyl) alkanes; Tris-(hydroxyphenyl)alkanes

Abstract

A process is disclosed for the production of 2,2-bis(4-hydroxyphenyl) propane, herein referred to as bisphenol-A, from by-products remaining after purification distillation of bisphenol-A produced from a condensation reaction of phenol and acetone. The process comprises mixing the by-products with phenol and treating the resulting mixture with anhydrous hydrogen bromide to isomerize those by-products isomerizable to bisphenol-A for subsequent recovery.

Claims

1. A process for the production of 2,2-bis(4-hydroxyphenyl)propane from by-products which contain products isomerizable to 2,2-bis(4-hydroxyphenyl)propane and which remain after purification distillation of 2,2-bis(4-hydroxyphenyl)propane produced by the condensation of phenol and acetone, said process comprising

(i) preparing a starting mixture of by-products and phenol, said by-products containing products isomerizable to 2,2-bis(4-hydroxyphenyl)propane;

(ii) adding anhydrous hydrogen bromide to the starting mixture and isomerizing said by-products to 2,2-bis(4-hydroxyphenyl)propane at ambient pressure; and

(iii) subsequently recovering said 2,2-bis(4-hydroxyphenyl)propane.

2. A process as defined in claim 1 wherein the products isomerizable to 2,2-bis(4-hydroxyphenyl)propane are higher condensation products of bisphenol-A.

3. A process as defined in claim 1 wherein the products isomerizable to 2,2-bis(4-hydroxyphenyl)propane are condensation products of phenol and acetone.

4. A process as defined in claim 1 wherein the by-products and phenol in the starting mixture are essentially equal in weight.

5. A process as defined in claim 1 wherein the addition of anhydrous hydrogen bromide is continuous throughout the time of reaction.

6. A process as defined in claim 1 wherein about 4% by weight of anhydrous hydrogen bromide is added to the starting mixture.