Process for crystallizing an adduct of 2,2-di(4-hydroxyphenyl) propane and phenol

• US 4,209,646 A
• Filed: 09/26/1977
• Issued: 06/24/1980
• Est. Priority Date: 10/31/1974
• Status: Expired due to Term

• Current Assignee: Rhone-Poulenc Industries
• Original Assignee: Rhone-Poulenc Industries
• Inventors: Gac, Robert, Levet, Frederic, Dal Pont, Jean-Pierre
• Primary Examiner(s): Lone, Werren B.
• Application Number:
  US05/836,768
• Time in Patent Office: 1,002 Days
• Field of Search: 260/621 R, 260/619 R, 260/619 A, 568/749, 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

2,2-di(4-hydroxyphenyl) propane, i.e., diphenylolpropane, is purified by preparing a liquid mixture of raw diphenylolpropane, phenol and water and applying reduced pressure thereto corresponding to the vapor pressure of the mixture while simultaneously cooling same whereby an adduct of pure diphenylolpropane and phenol is crystallized.

Claims

1. A process for crystallizing an adduct of pure diphenylolpropane and phenol, which comprises (i) preparing a liquid mixture of impure diphenylolpropane, phenol and water, said mixture comprising less than about 15% by weight of water and said mixture being prepared at a temperature sufficient to maintain same in a substantially liquid state, but not in excess of about 100°

C., (ii) cooling said substantially liquid mixture to a temperature at least as low as about 60°

C., while (iii) simultaneously applying thereto a vacuum essentially corresponding to the vapor pressure of the vapor phase of said mixture, and (iv) whereby an adduct of pure diphenylolpropane and phenol is crystallized.

2. The process as defined by claim 1, wherein said liquid mixture is comprised of between about 2 to 12% by weight of water based on the weight of said mixture.

3. The process as defined by claim 2, wherein the amount of water is between about 4 to 8%.

4. The process as defined by claim 1, wherein said liquid mixture is comprised of no greater than about 2% of water.

5. The process as defined by claim 1, wherein the amount of diphenylolpropane present in said mixture ranges between about 10% and 55% based on the weight of said mixture.

6. The process as defined by claim 1, wherein said preparing is carried out at a temperature between about 70°

C. and 100°

C.

7. The process as defined by claim 1, wherein said cooling is effected at a temperature between about 25°

C. and 60°

C.

8. The process as defined by claim 7, wherein said temperature is between about 40°

C. and 50°

C.

9. The process as defined by claim 1, wherein said vacuum is between about 20 and 120 mm Hg.

10. The process as defined by claim 1, further comprising recovering said adduct and removing phenol therefrom.

11. The process as defined by claim 1, wherein said vapor phase is removed and condensed, and at least part thereof recycled in said process.

12. The process as defined by claim 1, wherein said process is carried out continuously.

13. The process as defined by claim 1, wherein said process is carried out discontinuously.

14. The process as defined by claim 1, wherein said diphenylolpropane to be purified comprises the reaction product obtained by the condensation of phenol and acetone in the presence of an acid catalyst.

15. The process as defined by claim 1, further comprising separating crystals of said adduct from said mixture, adjusting the water content of the remaining mother-liquor to no greater than about 12% by weight, to form a second mixture, maintaining said second mixture in a substantially liquid state and cooling same to between 25°

C. and 60°

C. under a reduced pressure substantially equal to the vapor pressure of said second mixture to crystallize an adduct of pure diphenylolpropane and phenol from said second mixture.

16. The process as defined by claim 15, wherein prior to adjusting the water content thereof, said mother-liquor is concentrated by distillation of a portion of the phenol present therein.

17. The process as defined by claim 1, said process being conducted under no more than moderate stirring.

18. The process as defined by claim 1, wherein said impure diphenylolpropane comprises impurities selected from the group consisting of isomers of diphenylolpropane, 2,2,4-trimethyl(4-hydroxyphenyl) chromane, and mixtures thereof.

19. A process for crystallizing an adduct of pure diphenylolpropane and phenol, which comprises (i) preparing a liquid mixture of impure diphenylolpropane, phenol and water, said mixture comprising less than about 15% by weight of water and said mixture being prepared at a temperature sufficient to maintain same in a substantially liquid state, but not in excess of about 100°

C., (ii) cooling said substantially liquid mixture to a temperature at least as low as about 60°

C., while (iii) simultaneously applying thereto a vacuum essentially corresponding to the vapor pressure of the vapor phase of said mixture, said vapor pressure varying independently of the diphenylolpropane concentration in the mixture (i) but dependently upon the less than 15% by weight water in said mixture and dependently upon the cooling temperature (ii) at least as low as about 60°

C., and (iv) whereby an adduct of pure diphenylolpropane and phenol is crystallized.

20. A process for crystallizing an adduct of pure diphenylolpropane and phenol, which process essentially consists of (i) preparing a liquid mixture of impure diphenylolpropane, phenol and water, said mixture comprising less than about 15% by weight of water and said mixture being prepared at a temperature sufficient to maintain same in a substantially liquid state, but not in excess of about 100°

C., (ii) cooling said substantially liquid mixture to a temperature at least as low as about 60°

C., while (iii) simultaneously applying thereto a vacuum essentially corresponding to the vapor pressure of the vapor phase of said mixture, said vapor pressure varying independently of the diphenylolpropane concentration in the mixture (i) but dependently upon the less than 15% by weight water in said mixture and dependently upon the cooling temperature (ii) at least as low as about 60°

C., and (iv) whereby an adduct of pure diphenylolpropane and phenol is crystallized.

21. A process for crystallizing an adduct of pure diphenylolpropane and phenol, which comprises (i) preparing a substantially liquid mixture of impure diphenylolpropane, phenol and water, said mixture comprising less than about 15% by weight of water and said mixture being prepared at a temperature within the range of from about 70°

C. to about 100°

C., (ii) cooling said substantially liquid mixture to a temperature within the range of from about 25°

C. to about 60°

C., while simultaneously applying thereto a vacuum essentially corresponding to the vapor pressure of the vapor phase of said mixture and said vacuum being within the range of from about 20 to 120 mm Hg., and (iv) whereby an adduct of pure diphenylolpropane and phenol is crystallized.