Novel methods and blends for controlling rheology and transition temperature of liquid crystals

• US 20030036609A1
• Filed: 01/23/2002
• Published: 02/20/2003
• Est. Priority Date: 01/23/2001
• Status: Active Grant

• Current Assignee: Southwest Research Institute
• Original Assignee: Southwest Research Institute
• Inventors: Hanson, Douglas P., Wellinghoff, Stephen T.
• Granted Patent: US 7,108,801 B2
• Time in Patent Office: Days
• US Class Current: 526/75
• CPC Class Codes: C09K 19/20 linked by a chain containing carbon and oxygen atoms as chain links, e.g. esters or ethers
• CPC Class Codes: C09K 19/2007 the chain containing -COO- or -OCO- groups
• CPC Class Codes: C09K 19/52 characterised by components which are not liquid crystals, e.g. additives with special physical aspect: solvents, solid particles
• CPC Class Codes: C09K 2019/0448 the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate
• CPC Class Codes: C09K 2019/2078 Ph-COO-Ph-COO-Ph
• CPC Class Codes: C09K 2323/00 Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
• CPC Class Codes: Y10S 585/935 Halogen-containing

Abstract

Novel methods and blends for controlling rheology and transition temperature of photocurable mesogens while maintaining low polymerization shrinkage and without adversely affecting mechanical strength and stability of the cured resins.

Claims

1. A method for producing a blend comprising randomly substituted mesogens, said method comprising:

providing one or more platform molecules comprising terminal substituents X and Y; and

independently substituting a polymerizable group for at least one member selected from the group consisting of X and Y, thereby producing a blend of randomly substituted mesogens;

wherein said platform molecules have the following general structure;

wherein X and Y are independently selected from the group consisting of terminal functionalities and spacer groups;

R² is a bulky organic group whereby, when both X and Y are reacted polymerizable groups to produce polymerizable mesogens, R² provides sufficient steric hindrance to achieve a nematic state at room temperature while suppressing crystallinity of said polymerizable mesogens at room temperature;

R¹ and R³ are selected from groups less bulky than R².

2. The method of claim 1 wherein X comprises a terminal functionality and Y comprises a polymerizable group in about 50 wt % or more of said blend.

3. The method of claim 1 wherein X comprises a terminal functionality and Y comprises a polymerizable group in about 60 wt. % of said blend.

4. The method of claim 1 wherein X comprises a terminal functionality and Y comprises a polymerizable group in about 70 wt. % of said blend.

6. The method of claim 2 wherein said polymerizable groups are selected from the group consisting of acryloyloxy groups, methacryloyloxy groups, and acryloyloxy alkoxy and methacryloxyalkyloxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms and comprising CH₂ groups, wherein one or more of said CH₂ groups independently can be substituted by oxygen, sulfur, or an ester group;

provided that at least 2 carbon atoms separate said oxygen or said ester group.

7. The method of claim 4 wherein said polymerizable groups are selected from the group consisting of acryloyloxy groups, methacryloyloxy groups, and acryloyloxy alkoxy and methacryloxyalkyloxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms and comprising CH₂ groups, wherein one or more of said CH₂ groups independently can be substituted by oxygen, sulfur, or an ester group;

provided that at least 2 carbon atoms separate said oxygen or said ester group.

8. The method of claim 1 wherein said polymerizable groups are selected from the group consisting of cinnamoyloxy groups, acryloyloxy groups, methacryloyloxy groups, and acryloyloxy alkoxy and methacryloyloxy alkoxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms, thiol alkoxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms, said alkyl moiety comprising CH₂ groups, wherein one or more of said CH₂ groups independently can be substituted by oxygen, sulfur, or an ester group;

provided that at least 2 carbon atoms separate said oxygen or said ester group.

9. The method of claim 2 wherein said polymerizable groups are selected from the group consisting of cinnamoyloxy groups, acryloyloxy groups, methacryloyloxy groups, and acryloyloxy alkoxy and methacryloyloxy alkoxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms, thiol alkoxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms, said alkyl moiety comprising CH₂ groups, wherein one or more of said CH₂ groups independently can be substituted by oxygen, sulfur, or an ester group;

provided that at least 2 carbon atoms separate said oxygen or said ester group.

10. The method of claim 4 wherein said polymerizable groups are selected from the group consisting of cinnamoyloxy groups, acryloyloxy groups, methacryloyloxy groups, and acryloyloxy alkoxy and methacryloyloxy alkoxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms, thiol alkoxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms, said alkyl moiety comprising CH₂ groups, wherein one or more of said CH₂ groups independently can be substituted by oxygen, sulfur, or an ester group;

provided that at least 2 carbon atoms separate said oxygen or said ester group.

11. The method of claim 1 wherein said polymerizable groups are selected from the group consisting of acryloyloxy alkoxy groups and methacryloyloxy alkoxy groups.

12. The method of claim 2 wherein said polymerizable groups are selected from the group consisting of acryloyloxy alkoxy groups and methacryloyloxy alkoxy groups.

13. The method of claim 4 wherein said polymerizable groups are selected from the group consisting of acryloyloxy alkoxy groups and methacryloyloxy alkoxy groups.

14. The method of claim 1 wherein said polymerizable groups are methacryloyloxy alkoxy groups.

15. The method of claim 2 wherein said polymerizable groups are methacryloyloxy alkoxy groups.

16. The method of claim 4 wherein said polymerizable groups are methacryloyloxy alkoxy groups.

17. The method of claim 1 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

18. The method of claim 2 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

19. The method of claim 4 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

21. The method of claim 6 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups and spacer groups.

22. The method of claim 7 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

23. The method of claim 8 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

24. The method of claim 9 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

25. The method of claim 10 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

26. The method of claim 11 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

27. The method of claim 13 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

28. The method of claim 14 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

29. The method of claim 16 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

30. The method of claim 21 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

31. The method of claim 1 wherein said blend has a T_c is from about 20°

C. to about 37°

C.

32. The method of claim 2 wherein said blend has a T_c is from about 20°

C. to about 37°

C.

34. The method of claim 6 wherein said blend has a T_c is from about 20°

C. to about 37°

C.

5. The method of claim l wherein said polymerizable groups are selected from the group consisting of acryloyloxy groups, methacryloyloxy groups, and acryloyloxy alkoxy and methacryloxyalkyloxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms and comprising CH₂ groups, wherein one or more of said CH₂ groups independently can be substituted by oxygen, sulfur, or an ester group;

provided that at least 2 carbon atoms separate said oxygen or said ester group.

20. The method of claim 5 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

33. The method of claim 5 wherein said blend has a T_c is from about 20°

C. to about 37°

C.

35. A method comprising:

mixing a primary polymerizable mesogen comprising a primary nematic to isotropic transition temperature (T<sub>n→

isotropic</sub>) with an amount of a secondary polymerizable mesogen comprising a secondary T<sub>n→

isotropic</sub>, greater than said primary T<sub>n→

isotropic</sub> to produce a mixture having a curing temperature (T_c) sufficiently low to avoid discomfort during dental procedures;

wherein said amount of said secondary polymerizable mesogen is effective to increase said mixture T<sub>n→

isotropic</sub> to a temperature greater than said primary T<sub>n→

isotropic</sub> and to maintain a sufficient difference (Δ

T) between T_c and said mixture T<sub>n→

isotropic</sub> to produce a polymerization shrinkage of about 3 vol % change or less.

36. The method of claim 35 wherein said polymerization shrinkage is about 2 vol % change or less.

37. The method of claim 35 wherein said primary polymerizable mesogen is bis-(4-(6-methacryloyloxy-A-1-oxy)benzoyl)2-(t-butyl) quinone in which A is selected from the group consisting of a alkyl groups having from about 2-9 carbon atoms and mixtures thereof.

38. The method of claim 37 wherein A is a hexyl group.

39. A method comprising:

mixing a primary polymerizable mesogen comprising a primary nematic to isotropic transition temperature (T<sub>n→

isotropic</sub>) with an amount of a secondary polymerizable mesogen comprising a secondary T<sub>n→

isotropic</sub> greater than said primary T<sub>n→

isotropic</sub> to produce a mixture having a curing temperature (T_c) sufficiently low to avoid discomfort during dental procedures;

wherein said secondary polymerizable mesogen is selected from the group consisting of polymerizable elongated mesogens and mesogenic dimers and said amount of said secondary polymerizable mesogen is effective to increase said mixture T<sub>n→

isotropic</sub> to a temperature greater than said primary T<sub>n→

isotropic</sub> and to maintain a sufficient difference

(Δ

T) between T_c and said mixture T<sub>n→

isotropic</sub> to produce a polymerization shrinkage of about 3 vol. % change or less.

40. The method of claim 39 wherein said polymerization shrinkage is about 2 vol. % change or less.

41. The method of claim 40 wherein said primary polymerizable mesogen is bis-(4-(6-methacryloyloxy-A-1-oxy)benzoyl)2-(t-butyl) quinone in which A is selected from the group consisting of a alkyl groups having from about 2-9 carbon atoms and mixtures thereof.

42. The method of claim 39 wherein A is a hexyl group.

43. The method of claim 39 wherein said secondary polymerizable mesogen is a mesogenic dimer.

44. The method of claim 41 wherein said secondary polymerizable mesogen is a mesogenic dimer.

45. The method of claim 43 wherein said mesogenic dimer is decanedioic acid bis-(4-{2-tert-butyl-4-[4-(2-methyl-acryloyloxy)-benzoyloxy]-phenoxycarbonyl}-phenyl) ester {C0[H,TB,H] (MeAcry)(O) }₂ (seb).

46. The method of claim 39 wherein said T_c is from about 20°

C. to about 37°

C.

47. The method of claim 40 wherein said T_c is from about 20°

C. to about 37°

C.

48. The method of claim 41 wherein said T_c is from about 20°

C. to about 37°

C.

49. The method of claim 42 wherein said T_c is from about 20°

C. to about 37°

C.

50. The method of claim 43 wherein said T_c is from about 20°

C. to about 37°

C.

51. The method of claim 44 wherein said T_c is from about 20°

C. to about 37°

C.

52. The method of claim 45 wherein said T_c is from about 20°

C. to about 37°

C.

53. A method comprising mixing:

a quantity of bis-(4-(6-methacryloyloxy-A-1-oxy)benzoyl)2-(t-butyl) quinone in which A is selected from the group consisting of alkyl groups having from about 2-9 carbon atoms and comprising a primary nematic to isotropic transition temperature (T<sub>n→

isotropic</sub>); and

an amount of decanedioic acid bis-(4-{2-tert-butyl-4-[4-(2-methyl-acryloyloxy)-benzoyloxy]-phenoxycarbonyl}-phenyl) ester {C0[H,TB,H] (MeAcry)(O) }₂ (seb) to produce a mixture comprising a mixture T<sub>n→

isotropic</sub> that is sufficiently greater than said primary T<sub>n→

isotropic</sub> to maintain a sufficient difference (Δ

T) between T_c and said mixture T<sub>n→

isotropic</sub> to produce a polymerization shrinkage of about 3 vol % change or less.

54. The method of claim 53 wherein said polymerization shrinkage is about 2 vol % change or less.

55. A composition comprising mesogens having the following general structure:

56. The composition of claim 55 wherein about 60 wt. % or more of X and Y are polymerizable groups.

57. The composition of claim 55 wherein about 70 wt. % or more of X and Y are polymerizable groups.

58. The method of claim 55 wherein said polymerizable groups are selected from the group consisting of selected from the group consisting of acryloyloxy groups, methacryloyloxy groups, and acryloyloxy alkoxy groups and methacryloxy alkyloxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms and comprising CH₂ groups, wherein one or more of said CH₂ groups independently can be substituted by oxygen, sulfur, or an ester group;

provided that at least 2 carbon atoms separate said oxygen or said ester group.

59. The method of claim 56 wherein said polymerizable groups are selected from the group consisting of selected from the group consisting of acryloyloxy groups, methacryloyloxy groups, and acryloyloxy alkoxy groups and methacryloxy alkyloxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms and comprising CH₂ groups, wherein one or more of said CH₂ groups independently can be substituted by oxygen, sulfur, or an ester group;

provided that at least 2 carbon atoms separate said oxygen or said ester group.

60. The method of claim 57 wherein said polymerizable groups are selected from the group consisting of selected from the group consisting of acryloyloxy groups, methacryloyloxy groups, and acryloyloxy alkoxy groups and methacryloxyalkyloxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms and comprising CH₂ groups, wherein one or more of said CH₂ groups independently can be substituted by oxygen, sulfur, or an ester group;

provided that at least 2 carbon atoms separate said oxygen or said ester group.

61. The method of claim 57 wherein said polymerizable groups are selected from the group consisting of selected from the group consisting of cinnamoyloxy groups, acryloyloxy groups, methacryloyloxy groups, and acryloyloxy alkoxy groups, and acryloyloxy alkoxy groups and methacryloxy alkyloxy groups, and thiol alkoxy groups comprising an alkyl moiety having from about 2 to about 12 carbon atoms, said alkyl groups comprising CH₂ groups, wherein one or more of said CH₂ groups independently can be substituted by oxygen, sulfur, or an ester group;

provided that at least 2 carbon atoms separate said oxygen or said ester group.

62. The composition of claim 55 wherein said polymerizable groups are methacryloyloxy alkoxy groups.

63. The composition of claim 55 wherein said terminal functionalities are selected from the group consisting of hydroxyl groups, amino groups, sulfhydryl groups, halogen atoms, alkoxy groups, and spacer groups.

64. A composition comprising:

a primary polymerizable mesogen comprising a primary nematic to isotropic transition temperature (T<sub>n→

isotropic</sub>) and an amount of a secondary polymerizable mesogen comprising a secondary T<sub>n→

isotropic</sub> greater than said primary T<sub>n→

isotropic</sub> said mixture having a curing temperature (T_c) sufficiently low to avoid discomfort during dental procedures;

wherein said amount of said secondary polymerizable mesogen is effective to increase said mixture T<sub>→

isotropic</sub> to a temperature greater than said primary T<sub>n→

isotropic</sub> and to maintain a sufficient difference (Δ

T) between T_c and said mixture T<sub>n→

isotropic</sub> to produce a polymerization shrinkage of about 3 vol % change or less.

65. The composition of claim 64 wherein said polymerization shrinkage is about 2 vol % change or less.

66. The composition of claim 64 wherein said secondary polymerizable mesogen is selected from the group consisting of polymerizable elongated mesogens, mesogenic dimers, and polymerizable mesogens having a T_n→

isotropic greater than T<sub>n→

isotropic</sub> for said primary polymerizable mesogen.

67. The composition of claim 65 wherein said secondary polymerizable mesogen is selected from the group consisting of polymerizable elongated mesogens, mesogenic dimers, and polymerizable mesogens having a higher T_n→

isotropic than said primary polymerizable mesogen.

68. The composition of claim 64 wherein said primary polymerizable mesogen is bis-(4-(6-methacryloyloxy-A-1-oxy)benzoyl)2-(t-butyl) quinone in which A is selected from the group consisting of a alkyl groups having from about 2-9 carbon atoms and mixtures thereof.

69. The composition of claim 68 wherein A is a hexyl group.

70. A composition comprising:

a quantity of a primary polymerizable mesogen comprising bis-(4-(6-methacryloyloxy-A-1-oxy)benzoyl)2-(t-butyl) quinone in which A is selected from the group consisting of a alkyl groups having from about 2-9 and an amount of a decanedioic acid bis-(4-{2-tert-butyl-4-[4-(2-methyl-acryloyloxy)-benzoyloxy]-phenoxycarbonyl}-phenyl) ester {C0[H,TB,H] (MeAcry)(O) }2 (seb);

wherein said quantity and said amount are effective to produce curing temperature (T_c) sufficiently low to avoid discomfort during dental procedures;

wherein said amount of said decanedioic acid bis-(4-{2-tert-butyl-4-[4-(2-methyl-acryloyloxy)-benzoyloxy]-phenoxycarbonyl}-phenyl) ester {C0[H,TB,H] (MeAcry)(O) }₂ (seb) is effective to increase said mixture T<sub>n→

isotropic</sub> to a temperature greater than said primary T<sub>n→

isotropic</sub> and to maintain a sufficient difference (Δ

T) between T_c and said mixture T<sub>n→

isotropic</sub> to produce a polymerization shrinkage of about 3 vol % change or less.

71. The composition of claim 70 wherein said polymerization shrinkage is about 2 vol. % change or less.

72. The composition of claim 71 wherein A is a hexyl group.

73. The composition of claim 70 wherein said T_c is from about 20°

C. to about 37°

C.

74. The composition of claim 71 wherein said T_c is from about 20°

C. to about 37°

C.

75. The composition of claim 72 wherein said T_c is from about 20°

C. to about 37°

C.