Ultra-low shrinkage composite resins based on blended nematic liquid crystal monomers

• US 7,094,358 B2
• Filed: 03/07/2002
• Issued: 08/22/2006
• Est. Priority Date: 03/07/2001
• Status: Expired due to Fees

• Current Assignee: University of Texas System
• Original Assignee: University of Texas System
• Inventors: Satsangi, Neera, Norling, Barry K.
• Primary Examiner(s): WU, SHEAN CHIU
• Application Number:
  US10/093,001
• Publication Number:
  US 20030125435A1
• Time in Patent Office: 1,629 Days
• Field of Search: 252/299.01, 252/299.67, 252/299.64, 264/16, 523/109, 523/115, 523/120, 523/105, 523/113, 524/294, 524/534, 524/559, 522/1, 359/99, 359/102
• US Class Current: 252/299.01
• CPC Class Codes: C08G 63/60 derived from the reaction of a mixture of hydroxy carboxylic acids, polycarboxylic acids and polyhydroxy compounds
• CPC Class Codes: C08G 63/605 the hydroxy and carboxylic groups being bound to aromatic rings
• CPC Class Codes: C09K 19/2007 the chain containing -COO- or -OCO- groups
• CPC Class Codes: C09K 2019/0448 the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate

Abstract

Resin blends comprising liquid crystal monomers and secondary monomers useful to blend with liquid crystal monomers to maintain a nematic state under processing conditions while maintaining low cute shrinkage, particularly suitable for use in dental resin composites.

Claims

1. A resin blend comprising inorganic filler and primary liquid crystal monomer at a ratio to secondary monomer, said ratio and said secondary monomer being adapted to maintain said resin blend in a nematic liquid crystalline state for about 4 hours or more after addition of said inorganic filler at a temperature of 20°

C., wherein said blend exhibits about 2 vol. % or less polymerization shrinkage, wherein said liquid crystal monomer has the following general structure;

wherein;

R² is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups;

A is selected from the group consisting of branched and linear alkyl groups having from about 2 to about 10 carbon atoms, wherein said branched alkyl groups comprise branches having from about 1 to about 4 carbon atoms; and

R and R⁴ are acryloyl groups and methacryloyl groups;

wherein said secondary monomer has the following general structure;

wherein

n and m independently are selected from the group consisting of from about 2 to about 12; and

R is selected from the group consisting of H and CH₃.

2. The resin blend of claim 1 wherein n and m independently are selected from the group consisting of from about 2 to about 10.

3. The resin blend of claim 1 wherein n and m independently are selected from the group consisting of from about 2 to about 6.

4. The resin blend of claim 1 wherein n and m are 6.

5. A resin blend comprising inorganic filler and primary liquid crystal monomer at a ratio to secondary monomer, said ratio and said secondary monomer being adapted to maintain said resin blend in a nematic liquid crystalline state for about 4 hours or more after addition of said inorganic filler at a temperature of 20°

C., wherein said blend exhibits about 2 vol. % or less polymerization shrinkage, wherein said liquid crystal monomer has the following general structure;

wherein;

R² is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups;

A is selected from the group consisting of branched and linear alkyl groups having from about 2 to about 10 carbon atoms, wherein said branched alkyl groups comprise branches having from about 1 to about 4 carbon atoms; and

R and R⁴ are acryloyl groups and methacryloyl groups;

wherein said secondary monomer has the following general structure;

6. A resin blend comprising:

quantity of primary liquid crystal monomer having the following general structure;

 

wherein A is selected from the group consisting of branched and linear alkyl groups having from about 2 to about 12 carbon atoms, wherein said branched alkyl groups comprise branches having from about 1 to about 4 carbon atoms; and

a quantity of secondary monomer having the following structure;

wherein;

X, Y, and Z independently are selected from the group consisting of linear and branched alkyl groups having from about 2 to about 12 carbon atoms;

R¹, R³, R⁶, and R⁸ are selected from the group consisting of hydrogen atoms and methyl groups;

R² and R⁷ independently are selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups; and

,

R, R⁴, R⁵ and R⁹ are polymerizable groups selected from the group consisting of nucleophiles and electron deficient alkenes.

7. The resin blend of claim 6 comprising the primary liquid crystal monomer at a ratio to the secondary monomer, the ratio and the secondary monomer being adapted to maintain the resin blend in a nematic liquid crystalline state for about 30 minutes or more after addition of inorganic particulate filler at a temperature of 20°

C., wherein said resin blend exhibits about 2 vol. % or less polymerization shrinkage.

8. The resin blend of claim 6 wherein the primary liquid crystal monomer is at about a 3:

2 ratio to the secondary monomer.

9. The method of claim 6 wherein said polymerizable group is selected from the group consisting of ester groups, organic acid groups, amine groups, hydroxyl groups, and sulfhydryl groups.

10. The method of claim 6 wherein said polymerizable group is an electron deficient alkene independently selected from the group consisting of substituted and unsubstituted alkenyl ester groups comprising a polymerizable unsaturated carbon-carbon bond, wherein said alkenyl group has from about 2 to about 12 carbon atoms.

11. The method of claim 6 wherein said polymerizable group is an electron deficient alkene selected from the group consisting of alkenyl esters, acryloyl groups, methacryloyl groups.

12. The method of claim 6 wherein R⁴, R⁵ and R⁹ independently are selected from the group consisting of acryloyl groups and methacryloyl groups.

13. The method of claim 8 wherein R, R⁴, R⁵ and R⁹ independently are selected from the group consisting of acryloyl groups and methacryloyl groups.

14. The resin blend of claim 6 further comprising inorganic particulate filler.

15. The resin blend of claim 8 further comprising inorganic particulate filler.

16. The resin blend of claim 13 further comprising inorganic particulate filler.

17. The resin blend of claim 16 wherein the inorganic particulate filler comprises silicon.

18. The resin blend of claim 6 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

19. The resin blend of claim 13 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

20. The resin blend of claim 13 wherein R⁷ is a t-butyl group.

21. The resin blend claim 6 wherein X, Y, and Z have from about 2 to about 10 carbon atoms.

22. The resin blend of claim 6 wherein X, Y, and Z have from about 2 to about 6 carbon atoms.

23. The monomer of claim 22 wherein X, Y, and Z have 6 carbon atoms.

24. The resin blend of claim 6 wherein the secondary monomer has the following general structure:

wherein n and m independently are selected from the group consisting of from about 2 to about 11.

25. The resin blend of claim 6 wherein the resin blend has a nematic to isotopic transition temperature of about 50°

C., or more.

26. The blend of claim 25 wherein the nematic to isotopic transition temperature is about 60°

C., or more.

27. A resin blend comprising:

an amount of primary liquid crystal monomer having the following structure;

 

wherein A is selected from the group consisting of branched and linear alkyl groups having from about 2 to about 12 carbon atoms, wherein said branched alkyl groups comprise branches having from about 1 to about 4 carbon atoms; and

a quantity of secondary monomer having the following structure;

wherein;

X, Y, and Z independently are selected from the group consisting of linear and branched alkyl groups having from about 2 to about 12 carbon atoms;

R¹, R³, R⁶, and R⁸ are selected from the group consisting of hydrogen atoms and methyl groups;

R² and R⁷ independently are selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups; and

,

R, R⁴, R⁵ and R⁹ are polymerizable groups selected from the group consisting of nucleophiles and electron deficient alkenes.

28. The resin blend of claim 27 wherein the amount of primary liquid crystal monomer is at a ratio to the quanity of secondary monomer, the ratio and the secondary monomer being adapted to maintain the resin blend in a nematic liquid crystalline state for about 30 minutes or more after addition of inorganic particulate filler at a temperature of 20°

C., wherein said resin blend exhibits about 2 vol. % or less polymerization shrinkage.

29. The resin blend of claim 27 wherein the primary liquid crystal monomer is at about a 3:

2 ratio to the secondary monomer.

30. The method of claim 27 wherein said polymerizable group is selected from the group consisting of ester groups, organic acid groups, amine groups, hydroxyl groups, and sulfhydryl groups.

31. The method of claim 27 wherein said polymerizable group is an electron deficient alkene independently selected from the group consisting of substituted and unsubstituted alkenyl ester groups comprising a polymerizable unsaturated carbon-carbon bond, wherein said alkenyl group has from about 2 to about 12 carbon atoms.

32. The method of claim 27 wherein said polymerizable group is an electron deficient alkene selected from the group consisting of alkenyl esters, acryloyl groups, methacryloyl groups.

33. The method of claim 27 wherein R, R⁴, R⁵ and R⁹ independently are selected from the group consisting of acryloyl groups and methacryloyl groups.

34. The method of claim 29 wherein R, R⁴, R⁵ and R⁹ independently are selected from the group consisting of acryloyl groups and methacryloyl groups.

35. The resin blend of claim 27 further comprising inorganic particulate filler.

36. The resin blend of claim 29 further comprising inorganic particulate filler.

37. The resin blend of claim 34 further comprising inorganic particulate filler.

38. The resin blend of claim 37 wherein the inorganic particulate filler comprises silicon.

39. The resin blend of claim 27 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

40. The resin blend of claim 29 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

41. The resin blend of claim 34 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

42. The resin blend of claim 34 wherein R₇ is a t-butyl group.

43. The resin blend of claim 27 wherein X, Y, and Z have from about 2 to about 10 carbon atoms.

44. The resin blend of claim 27 wherein X, Y, and Z have from about 2 to about 6 carbon atoms.

45. The monomer of claim 42 wherein X, Y, and Z have 6 carbon atoms.

46. The resin blend of claim 27 wherein the resin blend has a nematic to isotopic transition temperature of about 50°

C., or more.

47. The blend of claim 46 wherein the nematic to isotopic transition temperature is about 60°

C., or more.

48. A resin blend comprising:

an amount of primary liquid crystal monomer having the following general structure;

 

wherein A is selected from the group consisting of branched and linear alkyl groups having from about 2 to about 12 carbon atoms, wherein said branched alkyl groups comprise branches having from about 1 to about 4 carbon atoms; and

a quantity of secondary monomer having the following structure;

wherein;

X, Y, and Z independently are selected from the group consisting of linear and branched alkyl groups having from about 2 to about 12 carbon atoms;

R¹, R³, R⁶, and R⁸ are selected from the group consisting of hydrogen atoms and methyl groups;

R² and R⁷ independently are selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups; and

,

R, R⁴, R⁵ and R⁹ are polymerizable groups selected from the group consisting of nucleophiles and electron deficient alkenes.

49. The resin blend of claim 48 wherein the amount of primary liquid crystal monomer is at a ratio to the quantity of secondary monomer, the ratio and the secondary monomer being adapted to maintain the resin blend in a nematic liquid crystalline state for about 30 minutes or more after addition of inorganic particulate filler at a temperature of 20°

C., wherein said resin blend exhibits about 2 vol. % or less polymerization shrinkage.

50. The resin blend of claim 48 wherein the primary liquid crystal monomer is at about a 3:

2 ratio to the secondary monomer.

51. The method of claim 48 wherein said polymerizable group is selected from the group consisting of ester groups, organic acid groups, amine groups, hydroxyl groups, and sulfhydryl groups.

52. The method of claim 48 wherein said polymerizable group is an electron deficient alkene independently selected from the group consisting of substituted and unsubstituted alkenyl ester groups comprising a polymerizable unsaturated carbon-carbon bond, wherein said alkenyl group has from about 2 to about 12 carbon atoms.

53. The method of claim 48 wherein said polymerizable group is an electron deficient alkene selected from the group consisting of alkenyl esters, acryloyl groups, methacryloyl groups.

54. The method of claim 48 wherein R, R⁴, R⁵ and R⁹ independently are selected from the group consisting of acryloyl groups and methacryloyl groups.

55. The method of claim 50 wherein R, R⁴, R⁵ and R⁹ independently are selected from the group consisting of acryloyl groups and methacryloyl groups.

56. The resin blend of claim 48 further comprising inorganic particulate filler.

57. The resin blend of claim 48 further comprising inorganic particulate filler.

58. The resin blend of claim 55 further comprising inorganic particulate filler.

59. The resin blend of claim 58 wherein the inorganic particulate filler comprises silicon.

60. The resin blend of claim 48 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

61. The resin blend of claim 50 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

62. The resin blend of claim 55 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

63. The resin blend of claim 55 wherein R⁷ is a t-butyl group.

64. The resin blend of claim 48 wherein X, Y, and Z have from about 2 to about 10 carbon atoms.

65. The resin blend of claim 48, wherein X, Y, and Z have from about 2 to about 6 carbon atoms.

66. The resin blend of claim 55 wherein X, Y, and Z have from about 2 to about 6 carbon atoms.

67. The monomer of claim 63 wherein X, Y, and Z have 6 carbon atoms.

68. The resin blend of claim 48 wherein the resin blend has a nematic to isotopic transition temperature of about 50°

C., or more.

69. The blend of claim 68 wherein the nematic to isotopic transition temperature is about 60°

C., or more.

70. A resin blend comprising:

an amount of primary liquid crystal monomer having the following general structure;

 

wherein A is selected from the group consisting of branched and linear alkyl groups having from about 2 to about 12 carbon atoms, wherein said branched alkyl groups comprise branches having from about 1 to about 4 carbon atoms; and

a quantity of secondary monomer having the following structure;

wherein;

X, Y, and Z independently are selected from the group consisting of linear and branched alkyl groups having from about 2 to about 12 carbon atoms;

R¹, R³, R⁶, and R⁸ are selected from the group consisting of hydrogen atoms and methyl groups;

R² and R⁷ independently are selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups; and

,

R, R⁴, R⁵ and R⁹ are polymerizable groups selected from the group consisting of nucleophiles and electron deficient alkenes.

71. The resin blend of claim 70 wherein the amount of primary liquid crystal monomer is at a ratio to the quantity of secondary monomer, the ratio and the secondary monomer being adapted to maintain the resin blend in a nematic liquid crystalline state for about 30 minutes or more after addition of inorganic particulate filler at a temperature of 20°

C., wherein said resin blend exhibits about 2 vol. % or less polymerization shrinkage.

72. The resin blend of claim 70 wherein the primary liquid crystal monomer is at about a 3:

2 ratio to the secondary monomer.

73. The method of claim 70 wherein said polymerizable group is selected from the group consisting of ester groups, organic acid groups, amine groups, hydroxyl groups, and sulfhydryl groups.

74. The method of claim 70 wherein said polymerizable group is an electron deficient alkene independently selected from the group consisting of substituted and unsubstituted alkenyl ester groups comprising a polymerizable unsaturated carbon-carbon bond, wherein said alkenyl group has from about 2 to about 12 carbon atoms.

75. The method of claim 70 wherein said polymerizable group is an electron deficient alkene selected from the group consisting of alkenyl esters, acryloyl groups, methacryloyl groups.

76. The method of claim 70 wherein R, R⁴, R⁵ and R⁹ independently are selected from the group consisting of acryloyl groups and methacryloyl groups.

77. The method of claim 72 wherein R, R⁴, R⁵ and R⁹ independently are selected from the group consisting of acryloyl groups and methacryloyl groups.

78. The resin blend of claim 70 further comprising inorganic particulate filler.

79. The resin blend of claim 70 further comprising inorganic particulate filler.

80. The resin blend of claim 77 further comprising inorganic particulate filler.

81. The resin blend of claim 80 wherein the inorganic particulate filler comprises silicon.

82. The resin blend of claim 70 wherein R⁷ independently is selected from group consisting of t-butyl groups and phenyl groups.

83. The resin blend of claim 72 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

84. The resin blend of claim 77 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

85. The resin blend of claim 77 wherein R⁷ is a t-butyl group.

86. The resin blend of claim 70 wherein X, Y, and Z have from about 2 to about 10 carbon atoms.

87. The resin blend of claim 70 wherein X, Y, and Z have from about 2 to about 6 carbon atoms.

88. The resin blend of claim 77 wherein X, Y, and Z have from about 2 to about 6 carbon atoms.

89. The monomer of claim 85 wherein X, Y, and Z have 6 carbon atoms.

90. The resin blend of claim 70 wherein the resin blend has a nematic to isotopic transition temperature of about 50°

C., or more.

91. The blend of claim 70 wherein the nematic to isotopic transition temperature is about 60°

C., or more.