Liquid crystal composition and liquid crystal element
A liquid crystal composition, which is a material used for an element for electromagnetic wave signal control in a frequency range of 1 GHz to 10 THz, satisfies at least one of characteristics such as a wide temperature range of a nematic phase and a large refractive index anisotropy and a small dielectric loss tangent (tan δ) in the frequency region used for control, and has an excellent balance of characteristics, and an element containing the composition. A liquid crystal composition including: at least one compound selected from the group consisting of compounds represented by Formula (1). For example, R 1 is C1-12 alkyl; Z 11 is a single bond; L 11 , L 12 , L 13 and L 18 are hydrogen; L 17 is methyl; Y 11 and Y 22 are hydrogen; and a, b, and c are respectively 0, 1, and 0.
1. A liquid crystal composition comprising:
at least one compound represented by Formula (1),
at least one compound represented by Formula (2); and
at least one compound selected from the group consisting of compounds represented by Formulae (3-1) to (3-6),
in Formula (1),
R 1 is C1-12 alkyl, and in this alkyl, at least one —CH 2 — may be substituted with —CH═CH— or —C≡C—;
a ring A 1 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, at least one hydrogen on these rings may be substituted with a halogen or C1-3 alkyl;
Z 11 and Z 12 are a single bond, —CH═CH—, —CF═CF—, —C≡C—, or —C≡C—C≡C—;
L 11 , L 12 , L 13 , L 14 , L 15 , L 16 , L 17 , and L 18 are hydrogen, a halogen, C1-3 alkyl, or C3-5 cycloalkyl;
Y 11 is hydrogen, a halogen, or C1-3 alkyl;
Y 12 is hydrogen or a halogen;
at least one of L 14 , L 15 , L 16 , L 17 , L 18 , and Y 11 is C1-3 alkyl; and
a and c are 0 or 1, b is 0, 1, or 2, and a sum of a, b, and c is 1 to 3, where when a is 0, b is 1, c is 0, Z 11 is a single bond, and L 11 , L 12 , L 13 , L 17 , L 18 , and Y 12 are hydrogen, Y 11 is not methyl,
in Formula (2),
R 2 is hydrogen, a halogen, or C1-12 alkyl in which 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 in these groups may be substituted with a halogen;
a 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, at least one hydrogen on these rings may be substituted with a halogen or C1-3 alkyl;
Z 21 and Z 22 are a single bond, —C≡C— or —C≡C—C≡C—;
L 21 , L 22 , L 23 , and L 24 are hydrogen, a halogen, C1-3 alkyl, or C3-5 cycloalkyl;
X 2 is —C≡C—CF 3 or —C≡C—C≡N;
Y 21 and Y 22 are hydrogen, a halogen, or C1-3 alkyl; and
d is 0 or 1, e is 0, 1, 2, or 3, and a sum of d and e is 1 to 3, and
in Formulae (3-1) to (3-6),
R 31 ′ is C1-12 alkyl, and in this alkyl, at least one —CH 2 — may be substituted with —O— and at least one —(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—;
R 32 ′ is R 31 ′ or —N═C═S;
L 32 ′, L 34 ′, L 35 ′, L 36 ′, L 37 ′, L 38 ′, and L 39 ′ are hydrogen, fluorine, or chlorine; and
in Formula (3-6), when L 35 ′, L 36 ′, L 38 ′, and L 39 ′ are hydrogen, R 32 ′ is —N═C═S.
2. A liquid crystal composition according to claim 1 , comprising:
at least one compound selected from the group consisting of compounds represented by Formulae (1-1) to (1-6) as the compound represented by Formula (1),
in Formulae (1-1) to (1-6),
R 1′ is C1-12 alkyl, and in this alkyl, at least one —(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—;
L 11′ , L 12′ , L 13′ , L 14′ , L 15′ , L 16′ , L 17′ , and L 18′ are hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl;
Y 11′ is hydrogen, fluorine, chlorine, methyl, or ethyl;
Y 12′ is hydrogen, fluorine, or chlorine;
at least one of L 14′ , L 15′ , L 16′ , L 17′ , L 18′ , and Y 11′ is methyl or ethyl; and
here, in Formula (1-1), when L 11′ , L 12′ , L 13′ , L 17′ , L 18′ , and Y 12′ are hydrogen, Y 11′ is not methyl.
3. The liquid crystal composition according to claim 1 ,
wherein a proportion of the compounds represented by Formula (1) is within a range of 5 weight % to 80 weight % based on a weight of the liquid crystal composition.
4. The liquid crystal composition according to claim 1 , comprising:
at least one compound selected from the group consisting of compounds represented by Formulae (2-1) to (2-8) as the compound represented by Formula (2),
in Formulae (2-1) to (2-8),
R 2′ is C1-12 alkyl, and in this alkyl, at least one —(CH 2 ) 2 — may be substituted with —CH═CH— or —C≡C—;
L 21′ , L 22′ , L 23′ , and L 24′ are hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl; and
Y 21′ and Y 22′ are hydrogen, fluorine, chlorine, methyl, or ethyl.
5. The liquid crystal composition according to claim 1 ,
wherein a proportion of the compounds represented by Formula (2) is within a range of 5 weight % to 50 weight % based on a weight of the liquid crystal composition.
6. The liquid crystal composition according to claim 1 ,
wherein a proportion of the compounds represented by Formulae (3-1) to (3-6) is within a range of 5 weight % to 50 weight % based on a weight of the liquid crystal composition.
7. The liquid crystal composition according to claim 1 ,
wherein refractive index anisotropy at 25° C. at a wavelength of 589 nm is 0.35 or more.
8. The liquid crystal composition according to claim 1 ,
wherein dielectric anisotropy at 25° C. in a frequency range below 1 MHz is 5 or more.
9. The liquid crystal composition according to claim 1 ,
wherein dielectric anisotropy at 25° C. at at least one frequency from 1 GHz to 10 THz is within a range of 0.50 to 3.0.
10. The liquid crystal composition according to claim 1 , further comprising:
an optically active compound.
11. The liquid crystal composition according to claim 1 , further comprising:
a polymerizable compound.
12. The liquid crystal composition according to claim 1 , further comprising:
at least one of an antioxidant, an ultraviolet absorber, an antistatic agent, and a dichroic dye.
13. An element comprising:
the liquid crystal composition according to claim 1 ,
wherein the element is used for switching and is capable of reversibly controlling a dielectric constant by reversibly changing an orientation direction of liquid crystal molecules.
14. An element comprising:
the liquid crystal composition according to claim 1 ,
wherein the element is used for controlling electromagnetic waves in a frequency range from 1 GHz to 10 THz.
15. A liquid crystal lens, comprising:
the liquid crystal composition according to claim 1 .
16. A birefringent lens for stereoscopic image display, comprising:
the liquid crystal composition according to claim 1 .