Liquid crystal composition and liquid crystal display device
View Patent ↗A liquid crystal composition is provided that satisfies at least one characteristic among the characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a low viscosity, a large optical anisotropy, a large dielectric anisotropy, a large specific resistance, a high stability to ultraviolet light and a high stability to heat, or is properly balanced regarding at least two characteristics. An AM device is provided that has a short response time, a large voltage holding ratio, a large contrast ratio, a long service life, and so forth. The liquid crystal composition has a nematic phase, wherein the first component contains a specific five rings compound having a large optical anisotropy and a large dielectric anisotropy, the second component contains a specific compound having a low viscosity. The liquid crystal display device contains the liquid crystal composition having a nematic phase and the composition thereof.
1. A liquid crystal composition having a nematic phase that includes two components, wherein a first component of the two components is at least one compound selected from the group of compounds represented by formulas (1-1) and (1-2), and the second component is at least one compound selected from the group of compounds represented by formula (2):
wherein R 1 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons; R 2 and R 3 are each independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which arbitrary hydrogen is replaced by fluorine; ring A, ring B and ring C are each independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene; Z 1 , Z 2 and Z 3 are each independently a single bond, ethylene, carbonyloxy or difluoromethyleneoxy; at least one of Z 1 , Z 2 and Z 3 is difluoromethyleneoxy; Z 4 and Z 5 are each independently a single bond, ethylene or carbonyloxy; X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 and X 8 are each independently hydrogen or fluorine; Y 1 is fluorine, chlorine or trifluoromethoxy; and m is 0 or 1.
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 formulas (1-1-1) to (1-1-3), (1-2-1) and (1-2-2):
wherein R 1 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons; X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , and X 8 are each independently hydrogen or fluorine; and Y 1 is fluorine, chlorine or trifluoromethoxy.
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 the formulas (1-1-1) and (1-1-2).
4. The liquid crystal composition according claim 1 , wherein the second component is at least one compound selected from the group of compounds represented by formulas (2-1) to (2-6):
wherein R 2 and R 3 are each independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkenyl having 2 to 12 carbons in which arbitrary hydrogen is replaced by fluorine.
5. The liquid crystal composition according to claim 4 , wherein the second component is at least one compound selected from the group of compounds represented by the formula (2-1).
6. The liquid crystal composition according to claim 4 , wherein the second component is a mixture of at least one compound selected from the group of compounds represented by the formula (2-1) and at least one compound selected from the group of compounds represented by the formula (2-4).
7. The liquid crystal composition according to claim 4 , wherein the second component is a mixture of at least one compound selected from the group of compounds represented by the formula (2-1), and at least one compound selected from the group of compounds represented by the formula (2-6).
8. The liquid crystal composition according to claim 4 , wherein the second component is a mixture of at least one compound selected from the group of compounds represented by the formula (2-1), at least one compound selected from the group of compounds represented by the formula (2-4), and at least one compound selected from the group of compounds represented by the formula (2-6).
9. The liquid crystal composition according to claim 1 , wherein a ratio of the first component is in the range of 5% to 25% by weight, and a ratio of the second component is in the range of 40% to 85% by weight, based on a total weight of the liquid crystal composition.
10. The liquid crystal composition according to claim 1 , wherein the composition further includes at least one compound selected from the group of compounds represented by formula (3) as a third component:
wherein R 1 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons; ring D is independently 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,4-phenylene, 3-fluoro-1,4-phenylene, 3,5-difluoro-1,4-phenylene, or 2,5-pyrimidine; Z 1 is independently a single bond, ethylene, carbonyloxy, or difluoromethyleneoxy; X 1 and X 2 are each independently hydrogen or fluorine; Y 1 is fluorine, chlorine or trifluoromethoxy; and n is 1, 2 or 3.
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 formulas (3-1) to (3-17):
Wherein R 4 is alkyl having 1 to 12 carbons, or alkenyl having 2 to 12 carbons.
12. The liquid crystal composition according to claim 11 , wherein the third component is at least one compound selected from the group of compounds represented by the formula (3-9).
13. The liquid crystal composition according to claim 11 , wherein the third component is at least one compound selected from the group of compounds represented by the formula (3-11).
14. The liquid crystal composition according to claim 11 , wherein the third component is at least one compound selected from the group of compounds represented by the formula (3-17).
15. The liquid crystal composition according to claim 11 , wherein the third component is a mixture of at least one compound selected from the group of compounds represented by the formula (3-11) and at least one compound selected from the group of compounds represented by the formula (3-17).
16. The liquid crystal composition according to claim 10 , wherein a ratio of the third component is in the range of 5% to 55% by weight based on a total weight of the liquid crystal composition.
17. The liquid crystal composition according to claim 1 , wherein the composition has a maximum temperature of a nematic phase of 70° C. or more, an optical anisotropy (25° C.) at a wavelength of 589 nm of 0.08 or more, and a dielectric anisotropy (25° C.) at a frequency of 1 kHz of 2 or more.
18. A liquid crystal display device containing the liquid crystal composition according to claim 1 .
19. The liquid crystal display device according to claim 18 , wherein an operation mode of the liquid crystal display device is a twisted nematic (TN) mode, an optically compensated bend (OCB) mode, or an in-plane switching (IPS) mode, and a driving mode of the liquid crystal display device is an active matrix mode.
20. The liquid crystal display device according to claim 18 , wherein an operation mode of the liquid crystal display device is a polymer sustained alignment (PSA) mode, and a driving mode of the liquid crystal display device is an active matrix mode.