Liquid crystal composition and liquid crystal display device
View Patent ↗The subject 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 high stability to ultraviolet light, a high stability to heat and a large elastic constant, or that is suitably balanced regarding at least two of the characteristics. The subject 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 four-ring compound containing a dioxane ring and having a high maximum temperature and a large dielectric anisotropy as a first component, a specific two-ring compound having a small viscosity as a second component, a specific three-ring compound having a large dielectric anisotropy as a third component and a specific four-ring compound having a high maximum temperature and a large dielectric anisotropy, and also provides a liquid crystal display device containing this composition.
1. A liquid crystal composition that has a nematic phase and comprises four components, wherein a first component is at least one compound selected from the group of compounds represented by formula (1), a second component is at least one compound selected from the group of compounds represented by formula (2), a third component is at least one compound selected from the group of compounds represented by formula (3), and a fourth component is at least one compound selected from the group of compounds represented by formula (4):
wherein R 1 , R 2 , R 4 and R 5 are each independently alkyl having 1 to 12 carbons or alkenyl having 2 to 12 carbons; R 3 is 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; the ring A and the ring B are each independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 3,5-difluoro-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 , Y 2 and Y 3 are each independently 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):
wherein R 1 is alkyl having 1 to 12 carbons or alkenyl having 2 to 12 carbons.
3. 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):
wherein R 21 and R 31 are each independently alkyl having 1 to 12 carbons.
4. 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 (2-2) to formula (2-4):
wherein R 21 is independently alkyl having 1 to 12 carbons.
5. The liquid crystal composition according to claim 1 , wherein the third component is at least one compound selected from the group of compounds represented by formula (3-1):
wherein R 4 is alkyl having 1 to 12 carbons or alkenyl having 2 to 12 carbons.
6. The liquid crystal composition according to claim 1 , wherein the fourth component is at least one compound selected from the group of compounds represented by formula (4-1) to formula (4-3):
wherein R 5 is alkyl having 1 to 12 carbons or alkenyl having 2 to 12 carbons.
7. The liquid crystal composition according to claim 1 , wherein the ratio of the first component is in the range of approximately 5% to approximately 30% by weight, the ratio of the second component is in the range of approximately 5% to approximately 35% by weight, the ratio of the third component is in the range of approximately 5% to approximately 30% by weight, and the ratio of the fourth component is in the range of approximately 5% to approximately 30% by weight based on the total weight of the liquid crystal composition.
8. The liquid crystal composition according to claim 1 , 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 or alkenyl having 2 to 12 carbons; X 6 is hydrogen or fluorine; and Y 4 is fluorine, chlorine or trifluoromethoxy.
9. The liquid crystal composition according to claim 8 , wherein the fifth component is at least one compound selected from the group of compounds represented by formula (5-1):
wherein R 6 is alkyl having 1 to 12 carbons or alkenyl having 2 to 12 carbons.
10. The liquid crystal composition according to claim 1 , further comprising at least one compound selected from the group of compounds represented by formula (6) as a sixth component:
wherein R 7 is alkyl having 1 to 12 carbons or alkenyl having 2 to 12 carbons; the ring C 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 7 is hydrogen or fluorine; Y 5 is fluorine, chlorine or trifluoromethoxy; Z 1 is independently a single bond, ethylene or carbonyloxy; and m is 1, 2 or 3.
11. The liquid crystal composition according to claim 10 , wherein the sixth component is at least one compound selected from the group of compounds represented by formula (6-1) to formula (6-12):
wherein R 7 is alkyl having 1 to 12 carbons or alkenyl having 2 to 12 carbons.
12. The liquid crystal composition according to claim 1 , further comprising at least one compound selected from the group of compounds represented by formula (7) as a seventh component:
wherein R 8 is alkyl 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 9 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkoxymethyl having 2 to 12 carbons, alkenyl having 2 to 12 carbons, fluorine or chlorine; the ring D, the ring E and the ring F 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 2 is independently a single bond, ethylene or carbonyloxy; n is 0, 1 or 2; and at least one of the ring D and the ring E is not 1,4-cyclohexylene when n is 0.
13. The liquid crystal composition according to claim 12 , wherein the seventh component is at least one compound selected from the group of compounds represented by formula (7-1) to formula (7-14):
wherein R 8 is alkyl 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 9 is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkoxymethyl having 2 to 12 carbons, alkenyl having 2 to 12 carbons, fluorine or chlorine.
14. The liquid crystal composition according to claim 1 , wherein the dielectric anisotropy (25° C.) at a frequency of 1 kHz is approximately 17 or more.
15. A liquid crystal display device containing the liquid crystal composition according to claim 1 .
16. The liquid crystal display device according to claim 15 , wherein an operating mode of the liquid crystal display device is a TN mode, an OCB mode, an IPS mode, a FFS mode or a PSA mode, and a driving mode of the liquid crystal display device is an active matrix mode.