Process for the purification of 2,2-bis-(4-hydroxyphenyl)propane

• US 3,919,330 A
• Filed: 10/03/1974
• Issued: 11/11/1975
• Est. Priority Date: 11/02/1973
• Status: Expired due to Term

• Current Assignee: Arien Kwantes, Bernhard Stouthamer
• Original Assignee: Arien Kwantes, Bernhard Stouthamer
• Inventors: Kwantes, Arien, Stouthamer, Bernhard
• Primary Examiner(s): Morgenstern, Norman
• Application Number:
  US05/511,980
• Time in Patent Office: 404 Days
• Field of Search: 260/619A,619R
• 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

Crude 2,2-bis(4-hydroxyphenyl)propane containing impurities such as 2-(2-hydroxyphenyl)-2-(4-hydroxyphenyl)propane is purified by first dissolving the crude material in ethylene glycol and then adding a certain amount of water whereby the 2,2-bis(4hydroxyphenyl)propane is precipated and is then recovered by filtration or centrifigation.

Claims

1. A PROCESS FOR THE PURIFICATION OF A CRUDE 2,2-BIS(4HYDROXYPHENYL) PROPANE MIXTURE PREPARED BY REACTING PHENOL WITH ACETONE OR 2,2-DIMETHYL-1,3-DIOXOLANE IN THE PRESENCE OF AN ACID CATALYST, SAID CRUDE 2,2-BIS(4-HYDROXYPHENYL) PROPANE MIXTURE BEING FREE OF PHENOL, WHICH PROCESS COMPRISES, A. DISSOLVING THE CRUDE 2,2-BIS(4-HYDROXYPHENYL)PROPANE AND IMPURITIES IN ETHYLENE GLYCOL, B. CONTACTING THE ETHYLENE GLYCOL-CRUDE 2,2-BIS(4-HYDROXYPHENYLE-PROPANE SOLUTION WITH WATER WHEREIN THE WEIGHT RATIO OF WATER TO THE ETHYLENE GLYCOL-CRUDE 2,2-BIS(4HYDROXYPHENYL)PROPANE SOLUTION IS ABOUT 15:

100 TO ABOUT 40;

100, C. GRADUALLY COOLING AND AGITATING THE ETHYLENE GLYCOL-CRUDE 2,2-BISNJ-HYDROXYPHENYL)PROPANE-WATER SOLUTION SO AS TO FORM A PURIFIED 2,2-BIS(4-HYDROXYPHENYL)PROPANE PRECIPITATE, AND D. RECOVERING THE PURIFIED 2,2-BIS(4-HYDROXYPHENYLE)PROPANE.

2. A process according to claim 1 wherein the weight ratio of ethylene glycol to crude 2,2-bis(4-hydroxyphenyl)propane is about 10:

90 to about 60;

40.

3. A process according to claim 1 wherein steps 1(a) and 1(b) are conducted at a temperature of about 60*C to about 70*C.

4. A process according to claim 1 wherein the ethylene glycol-crude 2,2-bis(4-hydroxyphenyl)propane-water mixture is gradually cooled to a temperature of about 30*C.

5. A process according to claim 1 wherein the crude 2,2-bis(4-hydroxyphenyl)propane consists of at least 80% by weight 2,2-bis(4-hydroxyphenyl)propane.

6. A process according to claim 1 wherein the water added in step 1(b) is added in incremental amounts.

7. A process according to claim 1 wherein the crude 2,2-bis(4-hydroxyphenyl)propane is obtained from the reaction of 2,2-dimethyl-1,3-dioxolane and phenol and wherein the ethylene glycol to be used as the solvent in step 1(a) is at least partially obtained as a by-product of the reaction of 2,2-dimethyl-1,3-dioxolane and phenol.

8. A process according to claim 1 wherein the impurities found in the crude 2,2-bis(4-hydroxyphenyl)propane mixture include 2-(2-hydroxyphenyl)-2-(4-hydroxyphenyl)propane.

9. A process according to claim 1 wherein the 2-(2-hydroxyphenyl)-2-(4-hydroxyphenyl)propane contained in the mother liquor remaining after the removal of the crystals of 2,2-bis(4-hydroxyphenyl)propane is subjected to an isomerization treatment so as to convert at least some of said 2-(2-hydroxyphenyl)-2-(4-hydroxyphenyl)propane to 2,2-bis(4-hydroxyphenyl)-propane.