Four- or five-ring liquid crystal compound having lateral fluorine, liquid crystal composition, and liquid crystal display device
View Patent ↗The invention provides a liquid crystal compound having stability to heat, light and so forth, a wide temperature range of a nematic phase, a small viscosity, a suitable optical anisotropy, and a suitable elastic constant K 33 , and further having a suitable and negative dielectric anisotropy and an excellent compatibility with other liquid crystal compounds, and a liquid crystal composition having stability to heat, light and so forth, a low viscosity, a large optical anisotropy, a suitable and negative dielectric anisotropy, and a suitable elastic constant K 33 , a low threshold voltage, a high maximum temperature (phase-transition temperature on a nematic phase-isotropic phase) of a nematic phase, and a low minimum temperature of the nematic phase. The liquid crystal compound which has a specific structure having fluorine at a lateral position and also having phenylene in which hydrogen on the benzene ring is replaced by fluorine, and a liquid crystal composition containing the compound are prepared.
1. A compound represented by formula (a-1):
wherein
R 3 is alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, alkoxy having 1 to 9 carbons, alkoxyalkyl having 2 to 9 carbons, or alkenyloxy having 2 to 9 carbons;
R 4 is alkoxy having 1 to 9 carbons or alkenyloxy having 2 to 9 carbons;
rings A 4 and A 5 are each independently trans-1,4-cyclohexylene, cyclohexene-1,4-diyl, 1,3-dioxane-2,5-diyl, tetrahydropyran-2,5-diyl, pyrimidine-2,5-diyl, or pyridine-2,5-diyl;
L 3 and L 4 are each independently hydrogen or fluorine, and at least one of L 3 and L 4 is fluorine;
Z 4 and Z 5 are each independently a single bond, —(CH 2 ) 2 —, —(CH 2 ) 4 —, —CH═CH—, —C≡C—, —CH 2 O—, —OCH 2 —, —COO—, or —OCO—; and
o and p are each independently 0 or 1, and o+p is 1 or 2.
2. The compound according to claim 1 , which is represented by formula (a-2):
wherein
R 5 is alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, alkoxy having 1 to 9 carbons, alkoxyalkyl having 2 to 9 carbons, or alkenyloxy having 2 to 9 carbons;
R 6 is alkoxy having 1 to 9 carbons or alkenyloxy having 2 to 9 carbons;
ring A 6 is trans-1,4-cyclohexylene, cyclohexene-1,4-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2-5-diyl;
L 5 and L 6 are each independently hydrogen or fluorine, and at least one of L 5 and L 6 is fluorine; and
Z 6 is a single bond, —(CH 2 ) 2 —, —CH 2 O—, —OCH 2 —, —COO—, or —OCO—.
3. The compound according to claim 1 , which is represented by formula (a-3):
wherein
R 7 is alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, alkoxy having 1 to 9 carbons, alkoxyalkyl having 2 to 9 carbons, or alkenyloxy having 2 to 9 carbons;
R 8 is alkoxy having 1 to 9 carbons or alkenyloxy having 2 to 9 carbons;
rings A 7 and A 8 are each independently trans-1,4-cyclohexylene, cyclohexene-1,4-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl; and
L 7 and L 8 are simultaneously fluorine, or one of L 7 and L 8 is hydrogen and the other is fluorine.
4. The compound according to claim 2 , which is represented by formulas (a-4) to (a-6):
wherein
R 9 is alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, alkoxy having 1 to 9 carbons, alkoxyalkyl having 2 to 9 carbons, or alkenyloxy having 2 to 9 carbons;
R 10 is alkoxy having 1 to 9 carbons or alkenyloxy having 2 to 9 carbons; and
ring A 9 is trans-1,4-cyclohexylene, cyclohexene-1,4-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl.
5. The compound according to claim 4 , which is represented by formulas (a-7) to (a-9):
wherein R 11 is alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, or alkoxy having 1 to 9 carbons; and R 12 is alkoxy having 1 to 9 carbons or alkenyloxy having 2 to 9 carbons.
6. The compound according to claim 4 , which is represented by formulas (a-10) to (a-12):
wherein R 13 is alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, or alkoxy having 1 to 9 carbons; and R 14 is alkoxy having 1 to 9 carbons or alkenyloxy having 2 to 9 carbons.
7. The compound according to claim 4 , which is represented by formulas (a-13) to (a-18):
wherein R 15 is alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, or alkoxy having 1 to 9 carbons; and R 16 is alkoxy having 1 to 9 carbons or alkenyloxy having 2 to 9 carbons.
8. The compound according to claim 4 , which is represented by formulas (a-19) to (a-24):
wherein R 17 is alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons or alkoxy having 1 to 9 carbons; and R 18 is alkoxy having 1 to 9 carbons or alkenyloxy having 2 to 9 carbons.
9. A liquid crystal composition which has a negative dielectric anisotropy, comprising a first component which is at least one compound selected from compounds according to claim 1 , and a second component which is at least one compound selected from the group of compounds represented by formula (e-1), formula (e-2), and formula (e-3):
wherein
Ra 11 and Rb 11 are each independently alkyl having 1 to 10 carbons, and in the alkyl, —CH 2 — may be nonadjacently replaced by —O—, —(CH 2 ) 2 — may be nonadjacently replaced by —CH═CH—, and hydrogen may be replaced by fluorine;
ring A 11 , ring A 12 , ring A 13 , and ring A 14 are each independently trans-1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl; and,
Z 11 , Z 12 , and Z 13 are each independently a single bond, —CH 2 —CH 2 —, —CH═CH—, —C≡C—, —COO—, or —CH 2 O—.
10. A liquid crystal composition which has a negative dielectric anisotropy, comprising a first component which is at least one compound selected from the group of compounds according to claim 4 , and a second component which is at least one compound selected from the group of compounds represented by formula (e-1), formula (e-2), and formula (e-3).
11. The liquid crystal composition according to claim 10 , wherein the content ratio of the first component is in the range of 5% to 60% by weight and the content ratio of the second component is in the range of 40% to 95% by weight, based on the total weight of the liquid crystal composition.
12. The liquid crystal composition according to claim 9 , comprising, in addition to the first component and the second component, a third component which is at least one compound selected from the group of compounds represented by formulas (g-1) to (g-6):
wherein
Ra 21 and Rb 21 are each independently hydrogen or alkyl having 1 to 10 carbons, and in the alkyl, —CH 2 — may be nonadjacently replaced by —O—, and —(CH 2 ) 2 — may be nonadjacently replaced by —CH═CH—, and hydrogen may be replaced by fluorine;
ring A 21 , ring A 22 , and ring A 23 are each independently trans-1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl;
Z 21 , Z 22 , and Z 23 are each independently a single bond, —CH 2 —CH 2 —, —CH═CH—, —C≡C—, —OCF 2 —, —CF 2 O—, —OCF 2 CH 2 CH 2 —, —CH 2 CH 2 CF 2 O—, —COO—, —OCO—, —OCH 2 —, or —CH 2 O—;
Y 1 , Y 2 , Y 3 , and Y 4 are each independently fluorine or chlorine;
q, r, and s are each independently 0, 1 or 2, q+r is 1 or 2, q+r+s is 1, 2 or 3; and
t is 0, 1 or 2.
13. The liquid crystal composition according to claim 9 , comprising, in addition to the first component and the second component, a third component which is at least one compound selected from the group of compounds represented by formulas (h-1) to (h-7),
wherein
Ra 22 and Rb 22 are each independently a straight-chain alkyl having 1 to 8 carbons, a straight-chain alkenyl having 2 to 8 carbons, or alkoxy having 1 to 7 carbons;
Z 24 , Z 25 , and Z 26 are a single bond, —CH 2 CH 2 —, —CH 2 O—, or —OCH 2 —; and
Y 1 and Y 2 are simultaneously fluorine, or one of Y 1 and Y 2 is fluorine and the other is chlorine.
14. A liquid crystal composition which has a negative dielectric anisotropy, comprising a first component, a second component, and a third component, wherein the first component is at least one compound selected from the group of compounds represented by formulas (a-4) to (a-6),
wherein
R 9 is alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, alkoxy having 1 to 9 carbons, alkoxyalkyl having 2 to 9 carbons, or alkenyloxy having 2 to 9 carbons;
R 10 is alkoxy having 1 to 9 carbons or alkenyloxy having 2 to 9 carbons; and
ring A 9 is trans-1,4-cyclohexylene cyclohexene-1,4-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl;
the second component is at least one compound selected from the group of compounds represented by formula (e-1), formula (e-2), and formula (e-3),
wherein
Ra 11 and Rb 11 are each independently 1 to 10 carbons, and in the alkyl, —CH 2 — may be nonadjacent replaced by —O—, —(CH 2 ) 2 — may be nonadjacently replaced by —CH═CH—, and hydrogen may be replaced by fluorine;
ring A 11 , ring A 12 , ring A 13 , and ring A 14 are each independently trans-1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1,4-phenylene, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl; and,
Z 11 , Z 12 , and Z 13 are each independently a single bond, —CH 2 —CH 2 —, —CH═CH—, —C≡C—, —COO—, or —CH 2 O—; and
the third component is at least one compound selected from the group of compounds represented by formulas (h-1) to (h-7),
wherein
Ra 22 and Rb 22 are each independently a straight-chain alkyl having 1 to 8 carbons, a straight-chain alkenyl having 2 to 8 carbons, or alkoxy having 1 to 7 carbons;
Z 24 , Z 25 , and Z 26 are a single bond, —CH 2 CH 2 —, —CH 2 O—, or —OCH 2 —; and
Y 1 and Y 2 are simultaneously fluorine, or one of Y 1 and Y 2 is fluorine and the other is chlorine.
15. The liquid crystal composition according to claim 14 , wherein the content ratio of the first component is in the range of 5% to 60% by weight, the content ratio of the second component is in the range of 20% to 75% by weight, and the content ratio of the third component is in the range of 20% to 75% by weight, based on the total weight of the liquid crystal composition.
16. A liquid crystal display device comprising the liquid crystal composition according to claim 9 .
17. The liquid crystal display device according to claim 16 , wherein the operation mode thereof is a VA mode or a IPS mode, and the driving mode thereof is an active matrix mode.