PROCESS FOR THE PREPARATION OF COPOLYESTERS BASED ON 2,2,4,4-TETRAMETHYL-1,3-CYCLOBUTANEDIOL AND 1,4-CYCLOHEXANEDIMETHANOL

• US 20070276065A1
• Filed: 07/03/2007
• Published: 11/29/2007
• Est. Priority Date: 10/28/2005
• Status: Active Grant

• Current Assignee: Eastman Chemical Company
• Original Assignee: Eastman Chemical Company
• Inventors: Shackelford, Damon, Barton, Benjamin
• Granted Patent: US 8,586,701 B2
• Time in Patent Office: Days
• US Class Current: 524/132
• CPC Class Codes: C08G 63/199 Acids or hydroxy compounds containing cycloaliphatic rings
• CPC Class Codes: C08G 63/85 Germanium, tin, lead, arsenic, antimony, bismuth, titanium, zirconium, hafnium, vanadium, niobium, tantalum, or compounds thereof C08G63/823 takes precedence

Abstract

Disclosed is a process for the preparation of high molecular weight, thermoplastic copolyesters by reacting a diester composition comprising a dialkyl ester of terephthalic acid with a diol composition comprising a first diol component comprising 2,2,4,4-tetramethyl-1,3-cyclobutanediol and a second diol component comprising 1,4-cyclohexanedimethanol. The diester composition can be reacted with the first diol component to produce a polyester oligomer that can be reacted further with the second diol component to produce a modified polyester oligomer. The modified polyester oligomer can then be heated to form a copolyester. The process reduces the precipitation of poly(1,4-cyclohexylene dimethylene) terephthalate in the reaction mixture.

Claims

1. A process for the preparation of a copolyester, comprising:

reacting a diester composition comprising at least one dialkyl terephthalic acid ester with a diol composition, said diol composition comprising a first diol component comprising 2,2,4,4-tetramethyl-1,3-cyclobutanediol and a second diol component comprising 1,4-cyclohexanedimethanol, said reaction comprising

(i) reacting said first diol component with said diester composition to form a polyester oligomer;

(ii) reacting said second diol component with said polyester oligomer of step (i) to form a modified polyester oligomer; and

(iii) heating said modified polyester oligomer to form a thermoplastic, random copolyester having an inherent viscosity of about 0.4 to about 1.0 dL/g;

wherein the molar ratio of all diols in said diol composition to all diesters in said diester composition is about 1.2 to about 1.5.

2. The process according to claim 1 wherein said process further comprises reacting neopentyl glycol, diethylene glycol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,3-cyclohexanedimethanol, bisphenol A, polyalkylene glycol, or combinations thereof with said diester composition or said polyester oligomer.

3. The process according to claim 1 wherein said diester composition further comprises at least one dialkyl ester of one or more a dicarboxylic acids selected from naphthalenedicarboxylic, 1,4-cyclohexanedicarboxylic, isophthalic, fumaric, succinic, adipic, glutaric, azelaic, sebacic, resorcinol diacetic, diglycolic, 4,4′

-oxybis(benzoic), biphenyldicarboxylic, 4,4′

-methylenedibenzoic, trans-4,4′

-stilbenedicarboxylic, and sulfoisophthalic acids.

4. The process according to claim 1 wherein said diester composition further comprises at least one dialkyl ester of isophthalic acid.

5. The process according to claim 1 wherein said diol:

diester molar ratio is about 1.2 to about 1.40.

6. The process according to claim 5 wherein said diol:

diester molar ratio is about 1.2 to about 1.30.

7. The process according to claim 1 wherein said thermoplastic polyester comprises about 60 to about 100 mole percent, based on the total moles of diacid residues, of the residues of terephthalic acid, isophthalic acid, or combinations thereof;

and about 10 to about 90 mole percent, based on the total moles of diol residues, of the residues 1,4-cyclohexanedimethanol, about 10 to about 90 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 0 to about 80 mole percent of the residues of neopentyl glycol, diethylene glycol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,3-cyclohexanedimethanol, bisphenol A, polyalkylene glycol, or combinations thereof.

8. The process according to claim 1 wherein said dialkyl terephthalic acid ester comprises residues of a primary alcohol having from 1 to 8 carbon atoms.

9. The process according to claim 1 wherein said diester composition comprises about 100 mole percent dimethyl terephthalate, based on the total moles of diester in said diester composition.

10. The process according to claim 7 wherein said thermoplastic copolyester comprises about 80 to about 100 mole percent, based on the total diacid residues, of the residues of terephthalic acid and about 85 to greater than 50 mole percent, based on the total diol residues, of the residues of 1,4-cyclohexanedimethanol and about 15 to less than 50 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

11. The process according to claim 7 said thermoplastic copolyester comprises (a) diacid residues comprising about 70 to about 100 mole percent of the residues of terephthalic acid, 0 to about 30 mole percent of the residues of at least one aromatic dicarboxylic acid having up to 20 carbon atoms, and 0 to about 10 mole percent of the residues of at least one aliphatic dicarboxylic acid having up to 16 carbon atoms;

and (b) diol residues comprising about 20 to about 40 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and about 60 to about 80 mole percent of the residues of 1,4-cyclohexanedimethanol.

12. The process according to claim 11 wherein said diol residues comprise 20 to 35 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 60 to 70 mole percent of the residues of 1,4-cyclohexanedimethanol.

13. The process according to claim 11 wherein said diol residues comprise 30 to 40 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 60 to 70 mole percent of the residues of 1,4-cyclohexanedimethanol.

14. The process according to claim 11 wherein said diol residues comprise 20 to 25 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 75 to 80 mole percent of the residues of 1,4-cyclohexanedimethanol.

15. The process according to claim 11 wherein said diol residues comprise 30 to 35 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 65 to 70 mole percent of the residues of 1,4-cyclohexanedimethanol.

16. The process according to claim 10 wherein said inherent viscosity of said thermoplastic copolyester is about 0.5 to about 0.80 dL/g.

17. The process according to claim 12 wherein said inherent viscosity of said thermoplastic copolyester is about 0.55 to about 0.68 dL/g.

18. The process according to claim 13 wherein said inherent viscosity of said thermoplastic copolyester is about 0.60 to about 0.68 dL/g.

19. The process according to claim 14 wherein said inherent viscosity of said thermoplastic copolyester is about 0.65 to about 0.75 dL/g.

20. The process according to claim 15 wherein said inherent viscosity of said thermoplastic copolyester is about 0.55 to about 0.75 dL/g.

21. The process according to claim 20 wherein said inherent viscosity of said thermoplastic copolyester is about 0.60 to about 0.70 dL/g.

22. The process according to claim 10 wherein said thermoplastic copolyester has a glass transition temperature of about 85 to about 200°

C.

23. The process according to claim 22 wherein said thermoplastic copolyester has a glass transition temperature of about 100 to about 120°

C.

24. The process according to claim 23 wherein said thermoplastic copolyester has a glass transition temperature of about 105 to about 115°

C.

25. The process according to claim 24 wherein said thermoplastic copolyester has a glass transition temperature of about 110 to about 120°

C.

26. The process according to claim 1 wherein steps (i) and (ii) are carried out at a temperature of about 180 to about 270°

C. at an absolute pressure of about 45 kPa to about 550 kPa.

27. The process according to claim 1 wherein step (iii) is carried out at a temperature of about 220 to about 290°

C. at an absolute pressure of about 0.001 kPa to about 55 kPa after the addition of the first and second diol components is completed.

28. The process according to claim 1 wherein said first diol component comprises about 50 to about 100 mole percent of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol, based on the total moles of 2,2,4,4-tetramethyl-1,3-cyclobutanediol in said diol composition, and 0 to about 80 mole percent of said 1,4-cyclohexanedimethanol, based on the total moles of 1,4-cyclohexanedimethanol said diol composition.

29. The process according to claim 28 wherein said first diol component comprises about 100 mole percent of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and about 60 to about 80 mole percent of said 1,4-cyclohexanedimethanol.

30. The process according to claim 1 wherein said second diol component comprises about 20 to about 100 mole percent of said 1,4-cyclohexanedimethanol, based on the total moles of 1,4-cyclohexanedimethanol in diol composition, and 0 to about 50 mole percent of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol, based on the total moles of 2,2,4,4-tetramethyl-1,3-cyclobutanediol in said diol composition.

31. The process according to claim 30 wherein said second diol component comprises about 20 to about 40 mole percent of said 1,4-cyclohexanedimethanol.

32. The process according to claim 1 further comprising adding said first diol component incrementally to said diester composition in step (i), adding said second diol component incrementally to said polyester oligomer in step (ii), or a combination thereof.

33. The process according to claim 32 wherein said addition of said first and second diol components in step (i) and (ii) each are carried out in 2 or more stages.

34. The process according to claim 32 wherein said addition of said first and second diol components in step (i) and (ii) each are carried out continuously.

35. The process according to claim 1 which is carried out in the presence a thermal stabilizer comprising at least one of alkyl phosphate esters, aryl phosphate esters, mixed alkyl aryl phosphate esters, reaction products thereof, or mixtures.

36. The process according to claim 35 wherein said thermal stabilizer comprises triphenyl phosphate.

37. The process according to claim 1 which is carried out in the presence of at least one catalyst comprising at least one tin compound and, optionally, titanium, gallium, zinc, antimony, cobalt, manganese, magnesium, germanium, lithium, aluminum, compounds thereof, or aluminum compounds with lithium hydroxide or sodium hydroxide.

38. The process according to claim 37 wherein said catalyst comprises at least one tin compound.

39. The process according to claim 10 wherein said thermoplastic copolyester has an inherent viscosity of about 0.5 to about 0.8 dL/g, a Tg of about 100 to about 120°

C., and comprises (a) diacid residues comprising 100 mole percent of the residues of terephthalic acid; and

(b) diol residues comprising about 20 to about 40 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and about 60 to about 80 mole percent of the residues of 1,4-cyclohexanedimethanol;

(c) 1 to 100 ppm phosphorus, based on the total weight of the final copolyester, and (d) 15 to 400 ppm tin, based on the total weight of the final copolyester.

40. A process for the preparation of a copolyester, comprising:

reacting a diester composition, comprising at least one dialkyl terephthalic acid ester, with a diol composition, said diol composition comprising a first diol component comprising 2,2,4,4-tetramethyl-1,3-cyclobutanediol and a second diol component comprising 1,4-cyclohexanedimethanol, said reaction comprising

(i) reacting said first diol component with said diester component to form a polyester oligomer at a conversion of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol of at least 50 mole percent, based on the total moles of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol in said diol composition;

(ii) reacting said second diol component with said polyester oligomer of step (i) to form a modified polyester oligomer; and

(iii) heating said modified polyester oligomer to form a thermoplastic, random copolyester having an inherent viscosity of about 0.4 dL/g to about 1.0;

wherein the molar ratio of all diols in said diol composition to all diesters in said diester composition is about 1.1 to about 1.5.

41. The process according to claim 40 wherein said process further comprises reacting neopentyl glycol, diethylene glycol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,3-cyclohexanedimethanol, bisphenol A, polyalkylene glycol, or combinations thereof with said diester composition or said polyester oligomer.

42. The process according to claim 40 wherein said diester component further comprises at least one dialkyl ester of isophthalic acid.

43. The process according to claim 40 wherein said modified copolyester reaction mixture has a total diol:

diester component molar ratio after step (ii) is about 1.1 to about 1.4.

44. The process according to claim 43 wherein the total diol:

diester component molar ratio is about 1.1 to about 1.3.

45. The process according to claim 43 wherein said total diol:

diester component molar ratio is about 1.1 to about 1.20.

46. The process according to claim 40 wherein said thermoplastic polyester comprises about 60 to 100 mole percent, based on the total moles of diacid residues, of the residues of terephthalic acid, isophthalic acid, or combinations thereof;

and about 10 to about 90 mole percent, based on the total moles of diol residues, of the residues 1,4-cyclohexanedimethanol, about 10 to about 90 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 0 to about 80 mole percent of the residues of neopentyl glycol, diethylene glycol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,3-cyclohexanedimethanol, bisphenol A, polyalkylene glycol, or combinations thereof.

47. The process according to claim 40 wherein said dialkyl terephthalic acid ester comprises residues of a primary alcohol having from 1 to 8 carbon atoms.

48. The process according to claim 40 wherein said diester component comprises 100 mole percent dimethyl terephthalate, based on the total moles of diester in said diester composition.

49. The process according to claim 45 wherein said thermoplastic copolyester comprises 80 to 100 mole percent, based on the total diacid residues, of the residues of terephthalic acid and about 85 to greater than 50 mole percent, based on the total diol residues, of the residues of 1,4-cyclohexanedimethanol and about 15 to less than 50 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

50. The process according to claim 46 said thermoplastic copolyester further comprises (a) diacid residues comprising 70 to 100 mole percent of the residues of terephthalic acid, 0 to 30 mole percent of the residues of at least one aromatic dicarboxylic acid having up to 20 carbon atoms, and 0 to 10 mole percent of the residues of at least one aliphatic dicarboxylic acid having up to 16 carbon atoms;

and (b) diol residues comprising 20 to 40 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 60 to 80 mole percent of the residues of 1,4-cyclohexanedimethanol.

51. The process according to claim 49 wherein said inherent viscosity of said thermoplastic copolyester is about 0.5 to about 0.80 dL/g.

52. The process according to claim 51 wherein said inherent viscosity of said thermoplastic copolyester is about 0.55 to about 0.75 dL/g.

53. The process according to claim 49 wherein said thermoplastic copolyester has a glass transition temperature of about 85 to about 200°

C.

54. The process according to claim 53 wherein said thermoplastic copolyester has a glass transition temperature of about 100 to about 120°

C.

55. The process according to claim 54 wherein said thermoplastic copolyester has a glass transition temperature of about 110 to about 120°

C.

56. The process according to claim 55 wherein said thermoplastic copolyester has a glass transition temperature of about 105 to about 115°

C.

57. The process according to claim 40 wherein steps (i) and (ii) are carried out at a temperature of about 180 to about 270°

C. at an absolute pressure of about 45 kPa to about 550 kPa.

58. The process according to claim 40 wherein step (iii) is carried out at a temperature of about 220 to about 290°

C. at an absolute pressure of about 0.001 kPa to about 55 kPa.

59. The process according to claim 40 wherein said first diol component comprises about 70 to about 100 mole percent of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol, based on the total moles of 2,2,4,4-tetramethyl-1,3-cyclobutanediol in said diol composition, and 0 to about 80 mole percent of said 1,4-cyclohexanedimethanol, based on the total moles of 1,4-cyclohexanedimethanol in said diol composition.

60. The process according to claim 59 wherein said first diol component comprises about 100 mole percent of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and about 60 to about 80 mole percent of said 1,4-cyclohexanedimethanol.

61. The process according to claim 40 wherein said second diol component comprises about 20 to about 100 mole percent of said 1,4-cyclohexanedimethanol, based on the total moles of 1,4-cyclohexanedimethanol in said diol composition, and 0 to about 30 mole percent of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol, based on the total moles of 2,2,4,4-tetramethyl-1,3-cyclobutanediol in said diol composition.

62. The process according to claim 61 wherein said second diol component comprises about 20 to about 40 mole percent of said 1,4-cyclohexanedimethanol and 0 mole percent of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

63. The process according to claim 40 further comprising adding said first diol component incrementally to said diester composition in step (i), adding said second diol component incrementally to said polyester oligomer in step (ii), or a combination thereof.

64. The process according to claim 62 wherein said addition of said first and second diol components in steps (i) and (ii) each are carried out continuously.

65. The process according to claim 40 which is carried out in at least 2 reactors.

66. The process according to claim 40 which is carried out in the presence of a thermal stabilizer comprising at least one of alkyl phosphate esters, aryl phosphate esters, mixed alkyl aryl phosphate esters, reaction products thereof, or mixtures thereof to said reaction zone.

67. The process according to claim 66 wherein said thermal stabilizer comprises triphenyl phosphate.

68. The process according to claim 40 which is carried out in the presence of at least one catalyst comprising at least one tin compound and, optionally, titanium, gallium, zinc, antimony, cobalt, manganese, magnesium, germanium, lithium, aluminum, compounds thereof, or aluminum compounds with lithium hydroxide or sodium hydroxide.

69. The process according to claim 68 wherein said catalyst comprises at least one tin compound.

70. The process according to claim 46 wherein said thermoplastic copolyester has an inherent viscosity of about 0.5 to about 0.8 dL/g, a Tg of about 100 to about 120°

C., and comprises (a) diacid residues comprising 100 mole percent of the residues of terephthalic acid; and

(b) diol residues comprising about 20 to about 30 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and about 70 to about 80 mole percent of the residues of 1,4-cyclohexanedimethanol;

(c) 1 to 100 ppm phosphorus, based on the total weight of the final copolyester, and (d) 15 to 400 ppm tin, based on the weight of the final copolyester.

71. A process for the preparation of a copolyester, comprising:

reacting a diester composition comprising dimethyl terephthalate with a diol composition comprising a first diol component comprising 2,2,4,4-tetramethyl-1,3-cyclobutanediol and a second diol component comprising 1,4-cyclohexanedimethanol, said reaction comprising

(i) reacting said first diol component comprising about 100 mole percent of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol, based on the total moles of 2,2,4,4-tetramethyl-1,3-cyclobutanediol in said diol composition, and 30 to about 80 mole percent of said 1,4-cyclohexanedimethanol, based on the total moles of 1,4-cyclohexanedimethanol in said diol composition, with said diester composition to form a polyester oligomer at a conversion of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol of at least 50 mole percent, based on the total moles of said 2,2,4,4-tetramethyl-1,3-cyclobutanediol in said diol composition;

(ii) reacting said second diol component comprising about 20 to about 70 mole percent of said 1,4-cyclohexanedimethanol based on the total moles of 1,4-cyclohexanedimethanol in said diol composition, with said polyester oligomer of step (i) to form a modified polyester oligomer; and

(iii) heating said modified polyester oligomer to form a thermoplastic, random copolyester having an inherent viscosity of about 0.4 dL/g to about 1.0;

wherein the molar ratio of all diols in said diol composition to all diesters in said diester composition is about 1.1 to about 1.5.

72. The process according to claim 71 wherein said diol:

diester molar ratio is about 1.1 to about 1.40.

73. The process according to claim 72 wherein said diol:

diester molar ratio is about 1.1 to about 1.20.

74. The process according to claim 71 wherein said thermoplastic copolyester comprises about 100 mole percent, based on the total diacid residues, of the residues of terephthalic acid and about 85 to greater than 50 mole percent, based on the total diol residues, of the residues of 1,4-cyclohexanedimethanol and about 15 to less than 50 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol.

75. The process according to claim 74 wherein said thermoplastic copolyester comprises diol residues comprising 20 to 40 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and 60 to 80 mole percent of the residues of 1,4-cyclohexanedimethanol.

76. The process according to claim 71 wherein said inherent viscosity of said thermoplastic copolyester is about 0.5 to about 0.80 dL/g.

77. The process according to claim 76 wherein said inherent viscosity of said thermoplastic copolyester is about 0.55 to about 0.75 dL/g.

78. The process according to claim 71 wherein said thermoplastic copolyester has a glass transition temperature of about 85 to about 200°

C.

79. The process according to claim 78 wherein said thermoplastic copolyester has a glass transition temperature of about 100 to about 120°

C.

80. The process according to claim 79 wherein said thermoplastic copolyester has a glass transition temperature of about 110 to about 120°

C.

81. The process according to claim 71 further comprising adding said first diol component incrementally to said diester composition in step (i), adding said second diol component incrementally to said polyester oligomer in step (ii), or a combination thereof.

82. The process according to claim 81 wherein said addition of said first and second diol components in step (i) and (ii) each are carried out continuously.

83. The process according to claim 71 which is carried out in at least 2 reactors.

84. The process according to claim 71 which is carried out in the presences of a thermal stabilizer comprising triphenyl phosphate and a catalyst comprising at least one tin compound.

85. The process according to claim 84 wherein said thermoplastic copolyester has an inherent viscosity of about 0.5 to about 0.8 dL/g, a Tg of about 100 to about 120°

C., and comprises (a) diacid residues comprising 100 mole percent of the residues of terephthalic acid; and

(b) diol residues comprising about 20 to about 30 mole percent of the residues of 2,2,4,4-tetramethyl-1,3-cyclobutanediol, and about 70 to about 80 mole percent of the residues of 1,4-cyclohexanedimethanol;

(c) about 1 to about 100 ppm phosphorus, based on the total weight of the final copolyester, and (d) about 15 to about 400 ppm tin, based on the weight of the final copolyester.