Modified copolyesters and optical films including modified copolyesters

• US 20060084780A1
• Filed: 10/18/2004
• Published: 04/20/2006
• Est. Priority Date: 10/18/2004
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Hebrink, Timothy J., Derks, Kristopher J., Li, Fuming B., Chien, Bert T., Merrill, William W., Johnson, Matthew B., Denker, Martin E., Thompson, Richard J.
• Granted Patent: US 7,345,137 B2
• Time in Patent Office: Days
• US Class Current: 528/272
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: C08G 63/181 Acids containing aromatic rings
• CPC Class Codes: C08G 63/183 Terephthalic acids
• CPC Class Codes: C08G 63/189 containing a naphthalene ring
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/31507 Of polycarbonate
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]

Abstract

Modified copolyesters having relatively low refractive indices and relatively high glass transition temperatures are disclosed. These modified copolyesters can be used in forming one or more layers in an optical film, such as a multilayer polymer film.

Claims

1. A polymer comprising;

a co-polyethylene naphthalate comprising carboxylate subunits and glycol subunits and having a refractive index of 1.58 or less at 632.8 nm and a glass transition temperature of 90 degree Celsius or greater.

2. A polymer according to claim 1, wherein the co-polyethylene naphthalate has a glass transition temperature of 100 degree Celsius or greater.

3. A polymer according to claim 1, wherein the co-polyethylene naphthalate has a glass transition temperature of 102 degree Celsius or greater.

4. A polymer according to claim 1, wherein the co-polyethylene naphthalate carboxylate subunits are derived from:

30 to 90 mol % t-butyl-isophthalic acid or an ester thereof;

10 to 50 mol % naphthalene dicarboxylate; and

0 to 50 mol % terephthalate.

5. A polymer according to claim 1, wherein the co-polyethylene naphthalate glycol subunits are derived from:

10 to 90 mol % cycloaliphatic diol; and

10 to 90 mol % branching diol.

6. A polymer according to claim 5, wherein the branching diol comprises neopentyl glycol, 2-butyl-2-ethyl-1,3propane diol, 2,2,4-triethyl pentane diol, or bisphenol A.

7. A polymer according to claim 1, wherein the co-polyethylene naphthalate further comprises 0.01 to 2.5 mol % of carboxylate or glycol subunits derived from compounds having three or more carboxylate or ester functionalities, three or more hydroxyl functionalities, or a combination thereof.

8. A polymer according to claim 5, wherein the cycloaliphatic diol comprises 1,4-cyclohexane dimethanol.

9. An optical film comprising a polymer according to claim 1.

10. A multilayered polymer film, comprising:

a plurality of first optical layers comprising a birefringent first copolyester or polyester; and

a plurality of second optical layers comprising a second copolyester being a co-polyethylene naphthalate having carboxylate subunits and glycol subunits and having an in-plane birefringence of 0.04 or less at 632.8 nm, after the multilayered polymer film has been formed and wherein the second copolyester has a refractive index of 1.58 or less at 632.8 nm and a glass transition temperature of 90 degree Celsius or greater.

11. A multilayered polymer film according to claim 10, wherein the second copolyester has a glass transition temperature of 100 degree Celsius or greater.

12. A multilayered polymer film according to claim 10, wherein the second copolyester has a glass transition temperature of 102 degree Celsius or greater.

13. A multilayered polymer film according to claim 10, wherein the second copolyester carboxylate subunits are derived from:

30 to 90 mol % t-butyl-isophthalic acid or an ester thereof; and

10 to 50 mol % naphthalene dicarboxylate; and

0 to 50 mol % terephthalate.

14. A multilayered polymer film according to claim 10, wherein the second copolyester glycol subunits are derived from:

10 to 90 mol % cycloaliphatic diol; and

10 to 90 mol % branching diol.

15. A polymer according to claim 14, wherein the branching diol comprises neopentyl glycol, 2-butyl-2-ethyl-1,3propane diol, 2,2,4-triethyl pentane diol, or bisphenol A.

16. A multilayered polymer film according to claim 10, wherein the second copolyester further comprises 0.01 to 2.5 mol % of carboxylate or glycol subunits derived from compounds having three or more carboxylate or ester functionalities, three or more hydroxyl functionalities, or a combination thereof.

17. A multilayered polymer film according to claim 14, wherein the cycloaliphatic diol comprises 1,4-cyclohexane dimethanol.

18. A multilayered polymer film according to claim 10, further comprising a strippable skin disposed on the multilayer polymer film.

19. A polymer comprising;

a co-polyethylene terephthalate comprising carboxylate subunits and glycol subunits having a refractive index of less than 1.54 at 632.8 nm and a glass transition temperature of 60 degree Celsius or greater.

20. A polymer according to claim 19, wherein the co-polyethylene terephthalate has a glass transition temperature of 65 degree Celsius or greater.

21. A polymer according to claim 19, wherein the co-polyethylene terephthalate has a glass transition temperature of 70 degree Celsius or greater.

22. A polymer according to claim 19, wherein the co-polyethylene terephthalate carboxylate subunits are derived from:

20 to 60 mol % t-butyl-isophthalic acid or an ester thereof;

10 to 50 mol % dimethyl terephthalate; and

20 to 50 mol % cycloaliphatic dicarboxylate.

23. A polymer according to claim 19, wherein the co-polyethylene terephthalate glycol subunits are derived from:

10 to 90 mol % cycloaliphatic diol; and

10 to 90 mol % branching diol.

24. A polymer according to claim 23, wherein the branching diol comprises neopentyl glycol, 2-butyl-2-ethyl-1,3propane diol, 2,2,4-triethyl pentane diol, or bisphenol A.

25. A polymer according to claim 19, wherein the co-polyethylene terephthalate further comprises 0.01 to 2.5 mol % of carboxylate or glycol subunits derived from compounds having three or more carboxylate or ester functionalities, three or more hydroxyl functionalities, or a combination thereof.

26. A polymer according to claim 23, wherein the cycloaliphatic diol comprises 1,4-cyclohexane dimethanol.

27. An optical film comprising a polymer according to claim 19.

28. A multilayered polymer film, comprising:

a plurality of first optical layers comprising a birefringent first copolyester or polyester; and

a plurality of second optical layers comprising a second copolyester being a co-polyethylene terephthalate having carboxylate subunits and glycol subunits and having an in-plane birefringence of 0.04 or less at 632.8 nm, after the multilayered polymer film has been formed and wherein the second copolyester has a refractive index of less than 1.54 at 632.8 nm and a glass transition temperature of 60 degree Celsius or greater.

29. A multilayered polymer film according to claim 28, wherein the second copolyester has a glass transition temperature of 65 degree Celsius or greater.

30. A multilayered polymer film according to claim 28, wherein the second copolyester has a glass transition temperature of 70 degree Celsius or greater.

31. A multilayered polymer film according to claim 28, wherein the second copolyester carboxylate subunits are derived from:

20 to 60 mol % t-butyl-isophthalic acid or an ester thereof;

10 to 50 mol % dimethyl terephthalate; and

20 to 50 mol % cycloaliphatic dicarboxylate.

32. A multilayered polymer film according to claim 28, wherein the second copolyester glycol subunits are derived from:

10 to 90 mol % cycloaliphatic diol; and

10 to 90 mol % branching diol.

33. A polymer according to claim 32, wherein the branching diol comprises neopentyl glycol, 2-butyl-2-ethyl-1,3propane diol, 2,2,4-triethyl pentane diol, or bisphenol A.

34. A multilayered polymer film according to claim 28, wherein the second copolyester further comprises 0.01 to 2.5 mol % of carboxylate or glycol subunits derived from compounds having three or more carboxylate or ester functionalities, three or more hydroxyl functionalities, or a combination thereof.

35. A multilayered polymer film according to claim 32, wherein the cycloaliphatic diol comprises 1,4-cyclohexane dimethanol.

36. A multilayered polymer film according to claim 28, further comprising a strippable skin disposed on the multilayer polymer film.

37. A polymer comprising;

a co-t-butyl-isophthalic acid polymer comprising carboxylate subunits and glycol subunits having a refractive index of 1.53 or less at 632.8 nm and a glass transition temperature of 50 degree Celsius or greater.

38. A polymer according to claim 37, wherein the co-t-butyl-isophthalic acid polymer has a glass transition temperature of 60 degree Celsius or greater.

39. A polymer according to claim 37, wherein the co-t-butyl-isophthalic acid polymer has a glass transition temperature of 70 degree Celsius or greater.

40. A polymer according to claim 37, wherein the co-t-butyl-isophthalic acid polymer carboxylate subunits are derived from:

30 to 70 mol % t-butyl-isophthalic acid or an ester thereof; and

30 to 70 mol % dimethyl cyclohexane dicarboxylate.

41. A polymer according to claim 37, wherein the co-t-butyl-isophthalic acid polymer glycol subunits are derived from:

10 to 90 mol % cycloaliphatic diol; and

10 to 90 mol % branching diol.

42. A polymer according to claim 41, wherein the branching diol comprises neopentyl glycol, 2-butyl-2-ethyl-1,3propane diol, 2,2,4-triethyl pentane diol, or bisphenol A.

43. A polymer according to claim 37, wherein the co-t-butyl-isophthalic acid polymer further comprises 0.01 to 2.5 mol % of carboxylate or glycol subunits derived from compounds having three or more carboxylate or ester functionalities, three or more hydroxyl functionalities, or a combination thereof.

44. A polymer according to claim 41, wherein the cycloaliphatic diol comprises 1,4-cyclohexane dimethanol.

45. An optical film comprising a polymer according to claim 37.

46. A multilayered polymer film, comprising:

a plurality of first optical layers comprising a birefringent first copolyester or polyester; and

a plurality of second optical layers comprising a second copolyester being a co-t-butyl-isophthalic acid polymer having carboxylate subunits and glycol subunits and having an in-plane birefringence of 0.04 or less at 632.8 nm, after the multilayered polymer film has been formed and wherein the second copolyester has a refractive index of 1.53 or less at 632.8 nm and a glass transition temperature of 50 degree Celsius or greater.

47. A multilayered polymer film according to claim 46, wherein the second copolyester has a glass transition temperature of 60 degree Celsius or greater.

48. A multilayered polymer film according to claim 46, wherein the second copolyester has a glass transition temperature of 70 degree Celsius or greater.

49. A multilayered polymer film according to claim 46, wherein the second copolyester carboxylate subunits are derived from:

30 to 70 mol % t-butyl-isophthalic acid or an ester thereof; and

30 to 70 mol % dimethyl cyclohexane dicarboxylate.

50. A multilayered polymer film according to claim 46, wherein the second copolyester glycol subunits are derived from:

10 to 90 mol % cycloaliphatic diol; and

10 to 90 mol % branching diol.

51. A polymer according to claim 50, wherein the branching diol comprises neopentyl glycol, 2-butyl-2-ethyl-1,3propane diol, 2,2,4-triethyl pentane diol, or bisphenol A.

52. A multilayered polymer film according to claim 50, wherein the second copolyester further comprises 0.01 to 2.5 mol % of carboxylate or glycol subunits derived from compounds having three or more carboxylate or ester functionalities, three or more hydroxyl functionalities, or a combination thereof.

53. A multilayered polymer film according to claim 50, wherein the cycloaliphatic diol comprises 1,4-cyclohexane dimethanol.

54. A multilayered polymer film according to claim 46, further comprising a strippable skin disposed on the multilayer polymer film.

55. A multilayered polymer film, comprising:

a plurality of first optical layers comprising a birefringent first copolyester or polyester; and

a plurality of second optical layers comprising a second copolyester being a copolyester and polycarbonate polymer blend and having an in-plane birefringence of 0.04 or less at 632.8 nm, after the multilayered polymer film has been formed.

56. A multilayered polymer film according to claim 55, wherein the second copolyester is a cyclo-aliphatic copolyester and polycarbonate blend.

57. A multilayered polymer film according to claim 55, wherein the second copolyester has a refractive index of 1.57 or less at 632.8 nm and a glass transition temperature of 100 degree Celsius or greater.

58. A multilayered polymer film, comprising:

a plurality of first optical layers comprising a birefringent first copolyester or polyester;

a plurality of second optical layers comprising a second copolyester having an in-plane birefringence of 0.04 or less at 632.8 nm, after the multilayered polymer film has been formed; and

a non-optical skin layer disposed on the plurality of first optical layers or plurality of second optical layers, the skin layer comprising a cyclo-aliphatic copolyester and polycarbonate blend.

59. A multilayered polymer film according to claim 58, wherein the non-optical skin layers comprise a blend of cyclo-aliphatic polyester and polycarbonate having a first refractive index value and an immiscible polymer having a second refractive index value, wherein the first refractive index value and the second refractive index value are the same.

60. A multilayered polymer film according to claim 59, wherein the non-optical skin layers comprise a blend of cyclo-aliphatic polyester and polycarbonate and CoPEN-tbia.

61. A multilayered polymer film according to claim 59, wherein the non-optical skin layers comprise a blend of cyclo-aliphatic polyester and polycarbonate and polystyrene or polystyrene copolymers.

62. A multilayered polymer film of claim 58, wherein the non-optical skin layers comprise a blend of cyclo-aliphatic polyester and polycarbonate having a first refractive index value and an immiscible polymer having a second refractive index value, wherein the first refractive index value and the second refractive index value are different.

63. A multilayered polymer film according to claim 62, wherein the non-optical skin layers comprise a blend of cyclo-aliphatic polyester and polycarbonate and polystyrene copolymers.

64. A multilayered polymer film, comprising:

a plurality of first optical layers comprising a birefringent first copolyester or polyester, the first optical layers are at least nearly truly uniaxially orientated; and

a plurality of second optical layers comprising a second copolyester being a co-polyethylene naphthalate having carboxylate subunits and glycol subunits and having an in-plane birefringence of 0.04 or less at 632.8 nm, after the multilayered polymer film has been formed and wherein the second copolyester has a glass transition temperature of 90 degree Celsius or greater.

65. A multilayered polymer film according to claim 64, wherein the second copolyester has a glass transition temperature of 100 degree Celsius or greater.

66. A multilayered polymer film according to claim 64, wherein the second copolyester has a glass transition temperature of 102 degree Celsius or greater.

67. A multilayered polymer film according to claim 64, wherein the second copolyester carboxylate subunits are derived from:

30 to 90 mol % t-butyl-isophthalic acid or an ester thereof; and

10 to 50 mol % naphthalene dicarboxylate; and

0 to 50 mol % terephthalate.

68. A multilayered polymer film according to claim 64, wherein the second copolyester glycol subunits are derived from:

10 to 90 mol % cycloaliphatic diol; and

10 to 90 mol % branching diol.

69. A polymer according to claim 68, wherein the branching diol comprises neopentyl glycol, 2-butyl-2-ethyl-1,3propane diol, 2,2,4-triethyl pentane diol, or bisphenol A.

70. A multilayered polymer film according to claim 64, wherein the second copolyester further comprises 0.01 to 2.5 mol % of carboxylate or glycol subunits derived from compounds having three or more carboxylate or ester functionalities, three or more hydroxyl functionalities, or a combination thereof.

71. A multilayered polymer film according to claim 64, wherein the cycloaliphatic diol comprises 1,4-cyclohexane dimethanol.

72. A multilayered polymer film according to claim 64, further comprising a strippable skin disposed on the multilayer polymer film.

73. A multilayered polymer film according to claim 64, wherein the first optical layers have a ratio of, a maximum birefringence in a plane normal to an orientation stretch to, a maximum in-plane birefringence of 0.2 or less.

74. A multilayered polymer film according to claim 64, wherein the first optical layers have a ratio of, a maximum birefringence in a plane normal to an orientation stretch to, a maximum in-plane birefringence of 0.15 or less.

75. A multilayered polymer film according to claim 64, wherein the first optical layers have a ratio of, a maximum birefringence in a plane normal to an orientation stretch to, a maximum in-plane birefringence of 0.1 or less.