Liquid crystal composition and liquid crystal display device
View Patent ↗A liquid crystal composition is provided that satisfies at least one of the characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of a nematic phase, a small 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 having a negative dielectric anisotropy contains a first component having especially negatively large dielectric anisotropy, a second component having a large negative dielectric anisotropy and a low minimum temperature, a third component having a high maximum temperature or a small viscosity. The liquid crystal display device contains the liquid crystal composition.
1. A liquid crystal composition having a negative dielectric anisotropy, comprising:
a first component which is at least one compound selected from the group of compounds represented by formula (1);
a second component which is at least one compound selected from the group of compounds represented by formula (2); and
a third component which is at least one compound selected from the group of compounds represented by formula (3):
wherein R 1 , R 2 , R 4 , R 5 and R 6 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; R 3 is alkenyl having 2 to 12 carbons; ring A, ring B and ring C are each independently 1,4-cyclohexylene or 1,4-phenylene; ring D and ring E are each independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene; Z 1 and Z 2 are each independently a single bond, ethylene, methyleneoxy or carbonyloxy; and m and n are each independently 1, 2 or 3; p and q are each independently 0, 1, 2 or 3; and the sum of p and q is 3 or less.
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) to (1-4):
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 or alkenyl having 2 to 12 carbons in which arbitrary hydrogen is replaced by fluorine; ring A 1 , ring A 2 , ring B 1 and ring B 2 are each independently 1,4-cyclohexylene or 1,4-phenylene; Z 1 and Z 2 are each independently a single bond, ethylene, methyleneoxy or carbonyloxy.
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 (1-3).
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 formulas (2-1) to (2-3):
wherein R 3 is independently alkenyl having 2 to 12 carbons; R 4 is 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.
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 (2-2).
8. The liquid crystal composition according to claim 5 , wherein the second component is a mixture of at least one compound selected from the group of compounds represented by formula (2-1) and at least one compound selected from the group of compounds represented by formula (2-2).
9. The liquid crystal composition according to claim 1 , wherein the third component is a mixture of at least one compound selected from the group of compounds represented by formulas (3-1) to (3-10):
wherein R 5 and R 6 are each independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons or alkenyl having 2 to 12 carbons, alkenyl having 2 to 12 carbons in which arbitrary hydrogen is replaced by fluorine.
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).
11. The liquid crystal composition according to claim 9 , 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 (3-4).
12. The liquid crystal composition according to claim 9 , 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 (3-6).
13. The liquid crystal composition according to claim 9 , wherein the third component is a mixture of at least one compound selected from the group of compounds represented by formula (3-6) and at least one compound selected from the group of compounds represented by formula (3-10).
14. The liquid crystal composition according to claim 9 , wherein the third component is a mixture of at least one compound selected from the group of compounds represented by formula (3-1), at least one compound selected from the group of compounds represented by formula (3-4) and at least one compound selected from the group of compounds represented by formula (3-6).
15. The liquid crystal composition according to claim 1 , wherein a ratio of the first component is from 5% by weight to 35% by weight based on the total weight of the liquid crystal composition, a ratio of the second component is from 20% by weight to 65% by weight based on the total weight of the liquid crystal composition, and a ratio of the third component is from 25% by weight to 65% by weight based on the total weight of the liquid crystal composition.
16. 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 less.
17. A liquid crystal display device that comprises the liquid crystal composition according to claim 1 .
18. The liquid crystal display device according to claim 17 , wherein the liquid crystal display device has an operation mode of a VA mode, an IPS mode or a PSA mode, and has a driving mode of an active matrix mode.