Liquid crystal composition, element and liquid crystal lens or a birefringent lens for stereoscopic image display
A liquid crystal composition as a material used for elements for controlling electromagnetic wave signals in a frequency range of 1 GHz to 10 THz, and an element containing this composition are provided. In the liquid crystal composition, a characteristic balance is excellent, and at least one of characteristics of a wide temperature range of a nematic phase, a large refractive index anisotropy in a frequency region used for control, and a small dielectric loss tangent (tan δ) is satisfied. A liquid crystal composition containing at least one compound selected from compounds represented by Formula (1) is provided: wherein R 1 is an alkyl having 1 to 12 carbon atoms; ring A 1 is 1,4-phenylene; L 11 , L 13 , L 14 , L 16 , Y 11 , and Y 12 are each hydrogen; L 12 is fluorine; and L 15 is methyl.
1. A liquid crystal composition, comprising at least one compound selected from the group of compounds represented by Formulas (1-1) to (1-4), (1-6) and (1-8),
in Formulas (1-1) to (1-4), (1-6) and (1-8),
R 1′ is an alkyl having 1 to 12 carbon atoms, provided that in this alkyl, at least one—(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—;
L 15 ′ and L 16 ′ are each hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl;
Y 11 ′ and Y 12 ′ are each hydrogen, fluorine, chlorine, methyl, or ethyl; and
at least one of L 15′ , L 16′ , Y 11′ , and Y 12′ is methyl or ethyl,
in Formulas (1-2) and (1-6),
L 11′ and L 13′ are each fluorine, chlorine, methyl, ethyl, or cyclopropyl
in Formulas (1-3),
L 12′ is fluorine, chlorine, methyl, ethyl, or cyclopropyl,
in Formulas (1-4) and (1-8),
L 12′ and L 14′ are each fluorine, chlorine, methyl, ethyl, or cyclopropyl, and
in Formulas (1-1),
at least two of L 15′ , L 16′ , Y 11′ , and Y 12′ are not hydrogen.
2. The liquid crystal composition according to claim 1 , wherein a proportion of the compound represented by Formula (1) is in a range of 5% by weight to 40% by weight based on a weight of the liquid crystal composition.
3. The liquid crystal composition according to claim 1 , comprising
at least one compound selected from compounds represented by Formula (2),
in Formula (2),
R 2 is hydrogen, a halogen, or an alkyl having 1 to 12 carbon atoms, provided that in this alkyl, at least one —CH 2 — may be substituted with —O— or —S—, and at least one —(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—, and at least one hydrogen may be substituted with a halogen;
ring A 2 is 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, 2,6,7-trioxabicyclo [2.2.2]octane -1,4-diyl, naphthalene -2,6-diyl, or pyridine-2,5-diyl, provided that at least one hydrogen on these rings may be substituted with a halogen or an alkyl having 1 to 3 carbon atoms;
Z 21 and Z 22 are each a single bond, —C≡C—, or —C≡C—C≡C—;
L 21 , L 22 , L 23 , and L 24 are each hydrogen, a halogen, an alkyl having 1 to 3 carbon atoms, or a cycloalkyl having 3 to 5 carbon atoms;
X 2 is —C≡C—CF 3 or —C≡C—C≡N;
Y 21 and Y 22 are each hydrogen, a halogen, or an alkyl having 1 to 3 carbon atoms; and
a is 0 or 1, and b is 1, 2, or 3, provided that a sum of a and b is 1 or more and 3 or less.
4. The liquid crystal composition according to claim 3 ,
wherein the liquid crystal composition contains at least one compound selected from the group of compounds represented by Formulas (2-1) to (2-8) as the compound represented by Formula (2),
in Formulas (2-1) to (2-8),
R 2′ is an alkyl having 1 to 12 carbon atoms, provided that in this alkyl, at least one—(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—;
L 22′ is hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl; and
Y 21′ and Y 22′ are each hydrogen, fluorine, chlorine, methyl, or ethyl,
in Formulas (2-1) and (2-2),
L 24′ is hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl,
in Formulas (2-3) to (2-6), and Formula (2-8),
L 21′ , L 23′ , and L 24′ are each hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl, and
in Formula (2-7),
L 21′ is hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl.
5. The liquid crystal composition according to claim 3 , wherein a proportion of the compound represented by Formula (2) is in a range of 5% by weight to 50% by weight based on a weight of the liquid crystal composition.
6. The liquid crystal composition according to claim 1 , comprising
at least one compound selected from compounds represented by Formula (3),
in Formula (3), R 31 is hydrogen, a halogen, or an alkyl having 1 to 12 carbon atoms, provided that in this alkyl, at least one —CH 2 — may be substituted with —O— or —S—, and at least one —(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—, and at least one hydrogen may be substituted with a halogen;
ring A 3 is 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, 2,6,7-trioxabicyclo [2.2.2]octane-1,4-diyl, naphthalene -2,6-diyl, or pyridine-2,5-diyl, provided that at least one hydrogen on these rings may be substituted with a halogen or an alkyl having 1 to 3 carbon atoms;
Z 31 and Z 32 are each a single bond, —CH═CH—, —CF═CF—, —C≡C—, or —C≡C—C≡C—;
L 31 , L 32 , L 33 , L 34 , L 35 , L 36 , and L 37 are each hydrogen, a halogen, an alkyl having 1 to 3 carbon atoms, or a cycloalkyl having 3 to 5 carbon atoms;
Y 31 and Y 32 are each hydrogen, a halogen, or an alkyl having 1 to 3 carbon atoms; and
c is 0 or 1, d is 0, 1, or 2, and a sum of c and d is 0 or more and 2 or less, provided that when a sum of c and d is 1, and Z 31 and Z 32 are each a single bond, L 31 , L 32 , L 33 , L 34 , L 35 , L 36 , L 37 , Y 31 , and Y 32 are each not an alkyl having 1 to 3 carbon atoms.
7. The liquid crystal composition according to claim 6 , wherein the at least one compound selected from the compounds represented by Formula (3) includes a compound in which Y 31 and Y 32 are both fluorine.
8. The liquid crystal composition according to claim 6 ,
wherein the liquid crystal composition contains at least one compound selected from the group of compounds represented by Formulas (3-1) to (3-8) as the compound represented by Formula (3),
in Formula (3-1), and Formulas (3-4) to (3-8),
R 31′ is an alkyl having 1 to 12 carbon atoms, provided that in this alkyl, at least one—(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—;
L 31′ , L 32′ , L 33′ , and L 37′ are each hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl; and
Y 31′ and Y 32′ are each hydrogen, fluorine, chlorine, methyl, or ethyl,
in Formulas (3-5), (3-7), and (3-8),
L 34′ , L 35′ , and L 36′ are each hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl,
in Formulas (3-2) and (3-3),
R 31′ is an alkyl having 1 to 12 carbon atoms, provided that in this alkyl, at least one—(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—;
L 31″ , L 32″ , L 33″ , and L 37″ are each hydrogen, fluorine, chlorine, or cyclopropyl; and
Y 31″ and Y 32″ are each hydrogen, fluorine, or chlorine, and
in Formula (3-3),
L 34′ , L 35″ , and L 36″ are each hydrogen, fluorine, chlorine, or cyclopropyl.
9. The liquid crystal composition according to claim 6 , wherein a proportion of the compound represented by Formula (3) is in a range of 30% by weight to 90% by weight based on a weight of the liquid crystal composition.
10. The liquid crystal composition according to claim 1 , wherein a refractive index anisotropy at 25° C. at a wavelength of 589 nm is 0.35 or more.
11. The liquid crystal composition according to claim 1 , wherein a dielectric constant anisotropy at 25°° C. in a frequency range of less than 1 MHz is 5 or more.
12. The liquid crystal composition according to claim 1 , wherein a dielectric constant anisotropy at 25° C. in at least one frequency range of 1 GHz to 10 THz is in a range of 0.50 to 3.0.
13. The liquid crystal composition according to claim 1 , comprising an optically active compound.
14. The liquid crystal composition according to claim 1 , comprising a polymerizable compound.
15. The liquid crystal composition according to claim 1 , comprising at least one of an antioxidant, an ultraviolet absorber, an antistatic agent, and a dichroic dye.
16. An element, which is used for switching and in which a dielectric constant can be reversibly controlled by reversibly changing an orientation direction of liquid crystal molecules, the element comprising the liquid crystal composition according to claim 1 .
17. An element, which is used for controlling electromagnetic waves in a frequency range of 1 GHz to 10 THz, the element comprising the liquid crystal composition according to claim 1 .
18. A liquid crystal lens or a birefringent lens for stereoscopic image display, comprising the liquid crystal composition according to claim 1 .