Liquid crystal composition and liquid crystal display device
The invention is to provide a liquid crystal composition that satisfies at least one of characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small viscosity, a suitable optical anisotropy, a large dielectric anisotropy, a large specific resistance, a large elastic constant, a high stability to ultraviolet light and a high stability to heat, or that is suitably balanced regarding at least two of the characteristics; and is to provide an AM device that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life and so forth. The invention provides a liquid crystal composition that has a nematic phase and includes a specific three-ring compound having a large dielectric anisotropy as a first component and a specific four-ring compound having a high maximum temperature and a large dielectric anisotropy as a second component, and a liquid crystal display device containing the composition.
1. A liquid crystal composition having a nematic phase and comprising two components, wherein a first component is at least one compound selected from the group of compounds represented by formula (1), and a second component is at least one compound selected from the group of compounds represented by formula (2):
wherein R 1 and R 2 are each independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons; the ring A is 1,4-cyclohexylene, 1,4-phenylene or tetrahydropyran-2,5-diyl; X 1 , X 2 , X 3 , X 4 and X 5 are each independently hydrogen or fluorine; and Y 1 is fluorine, chlorine or trifluoromethoxy.
2. The liquid crystal composition according to claim 1 , wherein the first component is at least one compound selected from the group of compounds represented by formula (1-1) and formula (1-2):
wherein R 1 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons.
3. The liquid crystal composition according to claim 2 , wherein the first component is at least one compound selected from the group of compounds represented by formula (1-1).
4. The liquid crystal composition according to claim 2 , wherein the first component is at least one compound selected from the group of compounds represented by formula (1-2).
5. The liquid crystal composition according to claim 1 , wherein the second component is at least one compound selected from the group of compounds represented by formula (2-1) to formula (2-4):
wherein R 2 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons.
6. The liquid crystal composition according to claim 5 , wherein the second component is at least one compound selected from the group of compounds represented by formula (2-1).
7. The liquid crystal composition according to claim 5 , wherein the second component is at least one compound selected from the group of compounds represented by formula (2-3).
8. The liquid crystal composition according to claim 1 , wherein the ratio of the first component is in the range of approximately 5% by weight to approximately 60% by weight and the ratio of the second component is in the range of approximately 5% by weight to approximately 50% by weight, based on the total weight of the liquid crystal composition.
9. The liquid crystal composition according to claim 1 , further comprising at least one compound selected from the group of compounds represented by formula (3) as a third component:
wherein R 3 and R 4 are each independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkoxymethyl having 2 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which arbitrary hydrogen is replaced by fluorine; the ring B, the ring C and the ring D are each independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene or tetrahydropyran-2,5-diyl; Z 1 is independently a single bond, ethylene or carbonyloxy; and m is 0, 1 or 2.
10. The liquid crystal composition according to claim 9 , wherein the third component is at least one compound selected from the group of compounds represented by formula (3-1) to formula (3-13):
wherein R 3 and R 4 are each independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkoxymethyl having 2 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which arbitrary hydrogen is replaced by fluorine.
11. The liquid crystal composition according to claim 10 , wherein the third component is at least one compound selected from the group of compounds represented by formula (3-1).
12. The liquid crystal composition according to claim 10 , wherein the third component is a mixture of at least one compound selected from the group of compounds represented by formula (3-1) and at least one compound selected from the group of compounds represented by formula (3-7).
13. The liquid crystal composition according to claim 9 , wherein the ratio of the third component is in the range of approximately 5% by weight to approximately 80% by weight based on the total weight of the liquid crystal composition.
14. The liquid crystal composition according to claim 9 , further comprising at least one compound selected from the group of compounds represented by formula (4) as a fourth component:
wherein R 5 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons; the ring E is independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 3,5-difluoro-1,4-phenylene, 1,3-dioxane-2,5-diyl or tetrahydropyran-2,5-diyl; X 6 and X 7 are each independently hydrogen or fluorine; Y 2 is fluorine or chlorine; Z 2 is independently a single bond, ethylene, carbonyloxy or difluoromethyleneoxy; and n is 1 or 2.
15. The liquid crystal composition according to claim 14 , wherein the fourth component is at least one compound selected from the group of compounds represented by formula (4-1) to formula (4-17):
wherein R 5 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons.
16. The liquid crystal composition according to claim 15 , wherein the fourth component is at least one compound selected from the group of compounds represented by formula (4-15).
17. The liquid crystal composition according to claim 15 , wherein the fourth component is at least one compound selected from the group of compounds represented by formula (4-17).
18. The liquid crystal composition according to claim 14 , wherein the ratio of the fourth component is in the range of approximately 5% by weight to approximately 60% by weight based on the total weight of the liquid crystal composition.
19. The liquid crystal composition according to claim 9 , further comprising at least one compound selected from the group of compounds represented by formula (5) as a fifth component:
wherein R 6 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons; the ring F is independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 3,5-difluoro-1,4-phenylene, 1,3-dioxane-2,5-diyl or tetrahydropyran-2,5-diyl; X 8 and X 9 are each independently hydrogen or fluorine; Y 3 is fluorine or chlorine; and Z 3 is independently a single bond or ethylene.
20. The liquid crystal composition according to claim 19 , wherein the fifth component is at least one compound selected from the group of compounds represented by formula (5-1) to formula (5-5):
wherein R 6 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons.
21. The liquid crystal composition according to claim 19 , wherein the ratio of the fifth component is in the range of approximately 5% by weight to approximately 30% by weight based on the total weight of the liquid crystal composition.
22. The liquid crystal composition according to claim 1 , wherein the maximum temperature of a nematic phase is approximately 70° C. or higher, the optical anisotropy (25° C.) at a wavelength of 589 nanometers is approximately 0.08 or more, and the dielectric anisotropy (25° C.) at a frequency of 1 kHz is approximately 4 or more.
23. A liquid crystal display device containing the liquid crystal composition according to claim 1 .
24. The liquid crystal display device according to claim 23 , wherein an operating mode of the liquid crystal display device is a TN mode, an OCB mode, an IPS mode, an FFS mode or a PSA mode, and a driving mode of the liquid crystal display device is an active matrix mode.