Reduced oligomer concentration in high purity polyalkylene glycols

• US 7,495,063 B2
• Filed: 02/03/2006
• Issued: 02/24/2009
• Est. Priority Date: 02/03/2006
• Status: Active Grant

• Current Assignee: Dow Global Technologies LLC (Dow, Inc.)
• Original Assignee: Dow Global Technologies, Inc. (Dow, Inc.)
• Inventors: Barner, Bruce Armin, Wilson, David Alan, Varineau, Pierre Thomas, Thompson, Robert Kirk
• Primary Examiner(s): Boykin; Terressa M
• Application Number:
  US11/346,910
• Publication Number:
  US 20070185307A1
• Time in Patent Office: 1,117 Days
• Field of Search: 528/196, 528/198, 528/425, 528/502.R, 210/634, 210/639, 526/144, 570/124, 570/177
• US Class Current: 528/196
• CPC Class Codes: C08G 65/26 from cyclic ethers and other compounds
• CPC Class Codes: C08G 65/2696 characterised by the process or apparatus used
• CPC Class Codes: C08G 65/30 Post-polymerisation treatment, e.g. recovery, purification, drying

Abstract

Polyalkylene glycol compositions having reduced low molecular weight oligomers are disclosed. Some compositions, particularly polyethylene glycol compositions, have a number average molecular weight range from about 3000 to about 10,000 g/mol and have a total oligomer concentration of less than about 400 ppm of all oligomers having a molecular weight of less than or equal to 812 g/mol and a total oligomer concentration of less than about 50 ppm of all oligomers having a molecular weight of less than or equal to 240 g/mol. Other polyalkylene compositions, particularly polyethylene glycol compositions, are characterized by a total oligomer concentration of less than about 90 ppm of all oligomers having a molecular weight less than or equal to 460 g/mol and are obtained without further processing to remove oligomers having a molecular weight of less than about 460 g/mol. Methods for making such compositions are also disclosed.

Claims

1. A method of making a polyalkylene glycol composition having reduced low molecular weight oligomers, comprising:

a) providing a catalyst and an initiator;

b) providing an alkylene oxide; and

c) reacting the catalyst, initiator and alkylene oxide to provide a polyalkylene composition having a number average molecular weight range from about 3000 to about 10,000

wherein the temperature and the concentration of water in the reaction are maintained at a level which is sufficiently low that the total concentration of all oligomers having a molecular weight of less than or equal to 812 g/mol in the resulting composition is less than 400 ppm.

2. The method of claim 1 wherein the concentration of water in the reactor at one or more time, t_i, follows the inequality:

3. The method of claim 1 wherein the concentration of water in the reactor at one or more time, ti, follows the inequality:

4. The method of claim 2 or 3, wherein the polyalkylene glycol is polyethylene glycol which comprises a second total concentration of less than about 50 ppm of all oligomers having a molecular weight of less than or equal to 240 g/mol.

5. The method of claim 4 wherein the polyethylene glycol composition comprises a third total concentration of less than about 1500 ppm of all oligomers having a molecular weight of less than or equal to 1472 g/mol.

6. The method of claim 4 wherein the first total oligomer concentration of all oligomers having a molecular weight of less than or equal to 812 g/mol is less than about 275 ppm.

7. The method of claim 1 wherein the temperature is maintained at less than about 165°

C.

8. The method of claim 7 wherein the temperature ranges from about 120°

C. to about 160°

C.

9. The method of claim 8 wherein the temperature ranges from about 130°

C. to about 155°

C.

10. The method of claim 9 wherein the temperature ranges from about 135°

C. to about 150°

C.

11. The method of claim 10 wherein the initiator is a diol and the catalyst comprises a alkali or alkaline earth hydroxide and uses high purity ethylene oxide with less than about 100 ppm water.

12. The method of claim 4 wherein the catalyst is selected from the group consisting of potassium hydroxide, sodium hydroxide, ammonium hydroxide, metal oxide catalysts, alkali and alkaline earth hydroxides, antimony hexafluoride, antimony hexachloride, Na, K, and alkali and alkaline earth methoxides.

13. The method of claim 12 wherein the catalyst is an alkali or alkaline earth hydroxide.

14. The method of claim 4 wherein the initiator is chosen from water, ethylene glycol, diethylene glycol, or any poly(oxyethylene) compound or other diol.

15. The method of claim 14 wherein the initiator is diethylene glycol.

16. The method of claim 4 wherein the alkoxide is ethylene oxide having less than about 100 ppm water.

17. The method of claim 1 wherein the polyalkylene glycol is a polyethylene glycol and the concentration of water in the reactor is less than or equal to 1.5 wt. percent at a time when the molecular weight, Mw, of the polyethylene glycol in the reactor is 1000 g/mol or less.

18. The method of claim 4 wherein the process includes first forming a lower molecular weight polyethylene glycol composition, and thereafter forming the polyethylene glycol composition from at least a portion of the first lower molecular weight polyethylene glycol composition.

19. The method of claim 18 wherein forming the polyethylene glycol composition is accomplished in the absence of catalyst other than that provided to form the first lower molecular weight polyethylene glycol composition.

20. A polyalkylene glycol composition having a number average molecular weight range from about 4000 to about 10,000 g/mol, comprising a first total oligomer concentration of less than about 400 ppm of all oligomers having a molecular weight of less than or equal to 812 g/mol and a second total oligomer concentration of less than about 50 ppm of all oligomers having a molecular weight of less than or equal to 240 g/mol.

21. The composition of claim 20 wherein the polyalkylene glycol composition is a polyethylene glycol composition.

22. The composition of claim 21 having a third total oligomer concentration of less than about 1500 ppm of all oligomers having a molecular weight of less than or equal to 1472 g/mol.

23. The composition of claim 21 wherein the number average molecular weight range is from about 4000 to about 5000 g/mol.

24. The composition of claim 21 wherein the number average molecular weight range is from about 5000 to about 7000 g/mol.

25. composition of claim 21 wherein the number average molecular weight range is from about 7000 to about 9000 g/mol.

26. The composition of claim 21 wherein the first total oligomer concentration is less than about 275 ppm of all oligomers having a molecular weight of less than or equal to 812 g/mol.

27. The composition of claim 26 having a third total oligomer concentration of less than about 1500 ppm of all oligomers having a molecular weight of less than or equal to 1472 g/mol.

28. The composition of claim 26 wherein the number average molecular weight range is from about 4000 to about 7000 g/mol.

29. The composition of claim 26 wherein the number average molecular weight range is from about 7000 to about 9000 g/mol.

30. The composition of claim 26 wherein the composition has a solid product form and with a bulk density of greater than about 0.50 g/cm³.

31. The composition of claim 26 wherein the composition has a solid product form and has an average particle size of less than about 1 mm.

32. A solid polyethylene glycol composition having a bulk density of greater than about 0.50 g/cm³ and less than 0 95 g/cm³ and a number average molecular weight range from about 3000 to about 10,000 g/mol, comprising a first total oligomer concentration of less than about 400 ppm of all oligomers having a molecular weight of less than or equal to 812 g/mol and comprising a second total oligomer concentration of less than about 50 ppm of all oligomers having a molecular weight of less than or equal to 240 g/mol.

33. The composition of claim 32 where the average particle size is less than 1 mm.

34. The composition of claim 32 having a third total oligomer concentration of less than about 1500 ppm of all oligomers having a molecular weight of less than or equal to 1472 g/mol.

35. The composition of claim 32 wherein the number average molecular weight range is from about 3000 to about 4000 g/mol.

36. The composition of claim 32 wherein the number average molecular weight range is from about 4000 to about 5000 g/mol.

37. The composition of claim 32 wherein the number average molecular weight range is from about 5000 to about 7000 g/mol.

38. The composition of claim 32 wherein the number average molecular weight range is from about 7000 to about 9000 g/mol.

39. The composition of claim 32 wherein the composition is essentially free of antioxidants.

40. A polyethylene glycol composition having a number average molecular weight range from about 3000 to about 10,000 g/mol, comprising a first total oligomer concentration of less than about 400 ppm of all oligomers having a molecular weight of less than or equal to 812 g/mol and a second total oligomer concentration of less than about 50 ppm of all oligomers having a molecular weight of less than or equal to 240 g/mol and comprises greater than 0.1 g of water per 1.0 g of polyethylene glycol.

41. A polyalkylene glycol composition having a number average molecular weight range from about 3000 to about 10,000 g/mol, comprising a first total oligomer concentration of less than about 90 ppm of all oligomers having a molecular weight less than or equal to 460 g/mol wherein the composition is obtained without further processing to remove oligomers having a molecular weight of less than about 460 g/mol.

42. The composition of claim 41 wherein the first total oligomer concentration is less than about 70 ppm of all oligomers having a molecular weight of less than or equal to 460 g/mol.

43. The composition of claim 41 having a second total oligomer concentration of less than about 1500 ppm of all oligomers having a molecular weight of less than or equal to 1472 g/mol.

44. The composition of claim 41 where the polyalkylene glycol composition is a polyethylene glycol composition wherein the number average molecular weight range is from about 3000 to about 4000 g/mol.

45. The composition of claim 41 where the polyalkylene glycol composition is a polyethylene glycol composition wherein the number average molecular weight range is from about 4000 to about 5000 g/mol.

46. he composition of claim 41 where the polyalkylene glycol composition is a polyethylene glycol composition wherein the number average molecular weight range is from about 5000 to about 7000 g/mol.

47. The composition of claim 41 where the polyalkylene glycol composition is a polyethylene glycol composition wherein the number average molecular weight range is from about 7000 to about 9000 g/mol.

48. The composition of claim 41 wherein the composition has a solid product form and has a bulk density of greater than about 0.50 g/cm³ to about 0.95 g/cm³.

49. The composition of claim 41 wherein the composition has a solid product form and has an average particle size of less than about 1 mm.

50. A method of making a polyethylene glycol composition having reduced low molecular weight oligomers, comprising:

a) providing a catalyst and an initiator;

b) providing an alkylene oxide; and

c) reacting the catalyst, initiator and alkylene oxide to provide a polyalkylene composition having a number average molecular weight range from about 3000 to about 10,000

wherein the temperature and the concentration of water in the reaction are maintained at a level which is sufficiently low that the total concentration of all oligomers having a molecular weight of less than or equal to 812 g/mol in the resulting composition is less than 400 ppm;

wherein the temperature is maintained at less than about 165°

C.; and

wherein the concentration of water in the reactor is less than or equal to 1.5 wt. percent at a time when the molecular weight, Mw, of the polyethylene glycol in the reactor is 1000 g/mol or less.