Purification of bisphenol-A

• US 4,507,509 A
• Filed: 01/04/1984
• Issued: 03/26/1985
• Est. Priority Date: 01/04/1984
• Status: Expired due to Fees

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Mendiratta, Ashok K., Morgan, Wayne F.
• Primary Examiner(s): Lone, Werren B.
• Application Number:
  US06/568,017
• Time in Patent Office: 447 Days
• Field of Search: 568/724
• US Class Current: 568/724
• CPC Class Codes: C07C 37/84 by crystallisation
• CPC Class Codes: C07C 39/16 Bis-(hydroxyphenyl) alkanes; Tris-(hydroxyphenyl)alkanes

Abstract

A method for purifying water-crystallized bisphenol-A involving treatment with an aqueous alkaline solution. The concentration of base preferably ranges from 0.1 to 25 weight percent of crude bisphenol-A. The crude bisphenol-A is a solid and preferably at a temperature in the range of about 10° to 80° C.

Claims

1. A process for purifying solid water-crystallized crude bisphenol-A comprising contacting solid water crystallized crude bisphenol-A with an aqueous alkaline solution and recovering said solid water-crystallized crude bisphenol-A in substantially the same form.

2. A method as in claim 1 wherein the aqueous alkaline solution contains a quantity of base that falls within the range of about 0.1 to 25 weight percent of the water-crystallized crude bisphenol-A.

3. A process as in claim 1 wherein the temperature of the water-crystallized crude bisphenol-A and aqueous alkaline solution is maintained within the range of about 10°

to 80°

C.

4. A process as in claim 1 wherein the base is selected from the group consisting of alkali-earth-metal hydroxides, alkali-metal carbonates, alkali-metal bicarbonates and alkali-metal hydroxides.

5. A process as in claim 1 wherein a nitrogen atmosphere is maintained over the aqueous crystallized crude bisphenol-A during washing.

6. A process in accordance with claim 1 wherein the crude bisphenol-A is crude 2,2-bis(4-hydroxyphenyl)-propane.

7. A process in accordance with claim 1 wherein the quantity of water within the aqueous alkaline solution is in the range of 1 to 5 parts by weight per part of water-crystallized crude bisphenol-A.

8. A process in accordance with claim 1 comprising the additional step of recovering the water-crystallized crude bisphenol-A from the aqueous alkaline solution after washing.

9. A process in accordance with claim 8 further comprising the step of washing the recovered water-crystallized crude bisphenol-A with from 1 to 5 parts by weight water.

10. A process in accordance with claim 1 wherein the base within the aqueous alkaline solution is selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonia, triethylamine, trimethylamine, pyridine and mixtures thereof.

11. A process in accordance with claim 10 wherein the quantity of base within the aqueous alkaline solution is within the range of 1 to 10 weight percent of the water-crystallized crude bisphenol-A.

12. A process in accordance with claim 8 further comprising the steps of (a) neutralizing the aqueous alkaline solution from which the water-crystallized crude bisphenol-A crystals were recovered;

(b) removing the solids which form; and

(c) recycling said solids to an acid catalyzed condensation reaction for the production of bisphenol-A.