Claims
- 1. A liquid crystal compositions which comprises one or more compounds of the formula:
- 2. The liquid crystal composition of claim 1 which exhibits a de Vries smectic A phase.
- 3. The liquid crystal composition of claim 1 which exhibits V-shaped switching when incorporated as aligned layer in an analog liquid crystal device.
- 4. The liquid crystal composition of claim 1 wherein the core rings A, B and C are selected from the group consisting of phenyls, fluorine-substituted phenyls, pyridines and pyrimidines.
- 5. The liquid crystal composition of claim 4 wherein d is 1 and D is —COO— or —OOC—.
- 6. The liquid crystal composition of claim 5 wherein Y is an alkyl or perfluorinated alkyl group having 1 to 3 carbon atoms.
- 7. The liquid crystal composition of claim 6 wherein R is an ether, a partially fluorinated ether or a perfluorinated ether.
- 8. The liquid crystal composition of claim 6 wherein R is RF.
- 9. The liquid crystal composition of claim 8 wherein Re has the formula: CnF2n+1CmH2m-wherein n is an integer ranging from 1 to about 10 and m is an integer ranging from 1 to about 10.
- 10. The liquid crystal composition of claim 8 wherein RF has the formula: CnF2n+1CmH2m wherein n is an integer ranging from 1 to about 20 and m is an integer ranging from 0 to about 10.
- 11. The liquid crystal composition of claim 1 wherein d is 1 and D is —CH2—CH2—.
- 12. The liquid crystal composition of claim 1 further comprising one or more components having any of the formulas:
- 13. The mixture of claim 12 wherein the one or more components of the listed formulas are present in a total amount of about 25% by weight or more of the mixture.
- 14. The liquid crystal composition of claim 12 further comprising one or more components having the formulas:
- 15. The liquid crystal composition of claim 12 further comprising one or more components having the formulas:
- 16. The liquid crystal composition of claim 15 further comprising one or more components having the formula:
- 17. The liquid crystal composition of claim 12 which has a total number of components of 5 or more.
- 18. The liquid crystal composition of claim 1 which comprises a first chiral nonracemic component which comprises one or more chiral nonracemic compounds of the formula.
- 19. The liquid crystal composition of claim 16 further comprising a second chiral nonracemic component which comprises one or more chiral nonracemic compounds selected from the group of compounds having formulas:
- 20. The liquid crystal composition of claim 19 wherein the second chiral nonracemic component is present in the mixture at a level of at least about 10% by weight.
- 21. The liquid crystal composition of claim 19 further comprising an achiral or racemic component which comprises one or more compounds having the formulas
- 22. The liquid crystal composition of claim 21 which contains a total number of components of 5 or more.
- 23. The liquid crystal composition of claim 21 which contains at least one component of each formula listed.
- 24. The liquid crystal composition of claim 1 wherein R is RF.
- 25. The liquid crystal composition of claim 24 wherein Y is an alkyl or fluorinated alkyl group having from 1 to 3 carbon atoms.
- 26. The liquid crystal composition of claim 25 wherein Y is CF3.
- 27. The liquid crystal composition of claim 26 wherein R1 is an alkyl group.
- 28. The liquid crystal composition of claim 27 wherein R1 is an alkyl group having from 4 to 8 carbon atoms.
- 29. The liquid crystal composition of claim 26 wherein the rings A, B and C are phenyl rings or fluorine-substituted phenyl rings.
- 30. The liquid crystal composition of claim 29 wherein d is 1 and D is —COO— or —OOC—.
- 31. The liquid crystal composition of claim 26 wherein at least one of rings A, B or C is a pyridine or a pyridine ring.
- 32. The liquid crystal composition of claim 31 wherein d is 1 and D is —COO— or —OOC—.
- 33. The liquid crystal composition of claim 26 wherein R1 contains one or more Si atoms.
- 34. The liquid crystal composition of claim 33 wherein R1 has the formula:
- 35. The liquid crystal composition of claim 33 wherein:
- 36. The liquid crystal composition of claim 33 wherein:
- 37. The liquid crystal composition of claim 33 wherein:
- 38. The liquid crystal composition of claim 1 wherein Y is CF3.
- 39. The liquid crystal composition of claim 38 wherein R1 is an alkyl group.
- 40. The liquid crystal composition of claim 38 wherein R1 contains a PDMS group.
- 41. The liquid crystal composition of claim 40 wherein rings A, B and C are phenyl rings or fluorine-substituted phenyl rings.
- 42. The liquid crystal composition of claim 40 wherein R is RF.
- 43. The liquid crystal composition of claim 1 wherein R is an ether having the formula CqH2q+1—O—CrH2r—, where q and r are integers from 1 to 20.
- 44. The liquid crystal composition of claim 43 wherein Y is CF3.
- 45. The liquid crystal composition of claim 44 wherein R1 is an alkyl group.
- 46. The liquid crystal composition of claim 45 wherein rings A, B and C are selected from the group consisting of phenyls, fluorine-substituted phenyls, pyridines and pyrimidines.
- 47. The liquid crystal composition of claim 46 wherein rings A, B and C are selected from the group consisting of phenyl rings, or fluorine-substituted phenyl rings.
- 48. The liquid crystal composition of claim 1 wherein R is an ether having the formula: CqH2q+1—O—CrH2r—O—CsH2s—, where q, r and s are integers from 1 to 20.
- 49. The liquid crystal composition of claim 1 which exhibits a Ps of 27 nC/cm2 or greater.
- 50. The liquid crystal composition of claim 1 which exhibits a Ps of 40 nC/cm2 or greater.
- 51. The liquid crystal composition of claim 1 which when introduced as an aligned layer in a liquid crystal device exhibits an electric rise time of 150 μ sec or less.
- 52. The liquid crystal composition of claim 1 which exhibits viscosity of 200 mP*S or less.
- 53. The liquid crystal composition of claim 1 which exhibits a smectic A phase which extends over a range of 20° C. or more.
- 54. The liquid crystal composition of claim 1 which exhibits both a smectic A and a smectic C phase.
- 55. The liquid crystal composition of claim 54 which exhibits a smectic C phase with a temperature range encompassing room temperature.
- 56. A compound having the formula:
- 57. The compound of claim 56 wherein Y is CF3 and R is RF.
- 58. The compound of claim 57 wherein RF is a partially fluorinated tail
- 59. The compound of claim 58 wherein RF has the formula CnF2n+1CmH2m— wherein n is an integer ranging from 1 to about 10 and m is an integer ranging from 1 to about 10.
- 60. The compound of claim 59 wherein RF is C4F9C4H8—.
- 61. The compound of claim 59 wherein RF is C4F9C6H12—.
- 62. The compound of claim 59 where rings A, B, and C are selected from the group consisting of phenyl groups and fluorine-substituted phenyl groups.
- 63. An electrooptical device comprising an aligned liquid crystal layer which comprises the liquid crystal composition of claim 1.
- 64. The electrooptical device of claim 63 wherein the device exhibits bistable switching.
- 65. The device of claim 64 which is an analog device exhibiting V-shaped switching.
- 66. An electrooptical device comprising an aligned layer which comprises the liquid crystal composition of claim 1 and which can be operated at low driving voltages at high frequency and using a symmetrical driving scheme for DC balance.
- 67. A method for making a bistable liquid crystal electrooptical device which comprises the step of aligning a liquid crystal composition of claim 1 which exhibits a de Vires smectic A phase in a bookshelf alignment in the device.
- 68. A method for making an electrooptical device that exhibits analog switching which comprises the step of aligning a liquid crystal composition of claim 1 which exhibits V-shaped switching in the device.
- 69. A method for making a liquid crystal composition which exhibits both bistable switching and V-shaped switching which comprises the step of combining one or more chiral nonracemic compounds of claim 1 with one or more liquid crystal compounds which have one or both tail groups that are partially fluorinated or that contain one or more Si atoms.
- 70. The method of claim 69 wherein about 25% to about 65% of a chiral nonracemic compound of claim 1 is combined to form the liquid crystal composition.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application takes priority under 35 U.S.C. 119(e) from U.S. provisional application No. 60/229,892 filed Sep. 1, 2000 which is incorporated by reference herein to the extent that it is not inconsistent with the disclosure of this application
Provisional Applications (1)
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Number |
Date |
Country |
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60229892 |
Sep 2000 |
US |