Liquid crystal composition and element

Abstract

A liquid crystal composition contains at least one compound selected from compounds represented by Formula (1), at least one compound selected from compounds represented by Formula (2), at least one compound selected from compounds represented by Formula (3), and at least one compound selected from compounds represented by Formula (4), and does not contain a compound represented by Formula(S). ##STR00001##

Claims

1. A liquid crystal composition which comprises at least one compound selected from compounds represented by Formula (1), at least one compound selected from compounds represented by Formula (2), at least one compound selected from compounds represented by Formula (3), and at least one compound selected from compounds represented by Formula (4), and does not comprise a compound represented by Formula(S), ##STR00051## in Formula (1) to Formula (4), R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are hydrogen, a halogen, or C1-12 linear alkyl in which at least one CH.sub.2 may be substituted with O or S, at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC, and at least one hydrogen in these groups may be substituted with a halogen; L.sup.11, L.sup.12, L.sup.13, L.sup.21, L.sup.22, L.sup.23, L.sup.31, L.sup.32, L.sup.33, L.sup.41, L.sup.42, L.sup.43, L.sup.44, and L.sup.45 are hydrogen, a halogen, C1-3 alkyl, or C3-5 cycloalkyl; Y.sup.11, Y.sup.21, Y.sup.22, Y.sup.23, Y.sup.31, Y.sup.32, Y.sup.33, Y.sup.34, Y.sup.35, Y.sup.36, and Y.sup.41 are hydrogen or a halogen; wherein at least one of L.sup.11, L.sup.12, and L.sup.13 is C1-3 alkyl, at least one of L.sup.31, L.sup.32, and L.sup.33 is C1-3 alkyl, and at least two of L.sup.41, L.sup.42, L.sup.43, L.sup.44, L.sup.45, and Y.sup.41 are not hydrogen, ##STR00052## in Formula(S), R.sup.S1 is hydrogen, a halogen, or C1-12 alkyl in which at least one CH.sub.2 may be substituted with O or S, at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC, and at least one hydrogen in these groups may be substituted with a halogen; L.sup.S1, L.sup.S2, and L.sup.S3 are hydrogen or fluorine; and Y.sup.S1 is hydrogen or fluorine.

2. The liquid crystal composition according to claim 1, which does not comprise a compound represented by Formula (T), ##STR00053## in Formula (T), R.sup.T1 is hydrogen, a halogen, or C1-12 alkyl in which at least one CH.sub.2 may be substituted with O or S, at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC, and at least one hydrogen in these groups may be substituted with a halogen; Y.sup.T1 and Y.sup.T2 are hydrogen or fluorine; and t is 0 or 1.

3. The liquid crystal composition according to claim 1, comprising, as the compound represented by Formula (1), at least one compound selected from a group of compounds represented by Formula (1-1) to Formula (1-10), ##STR00054## ##STR00055## in Formula (1-1) to Formula (1-10), R.sup.1 is C1-12 linear alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC.

4. The liquid crystal composition according to claim 1, comprising, as the compound represented by Formula (2), at least one compound selected from a group of compounds represented by Formula (2-1) to Formula (2-10), ##STR00056## ##STR00057## in Formula (2-1) to Formula (2-10), R.sup.2 is C1-12 linear alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC; Y.sup.22 is hydrogen, fluorine, or chlorine; and in Formula (2-10), Y.sup.21 is hydrogen, fluorine, or chlorine.

5. The liquid crystal composition according to claim 1, comprising, as the compound represented by Formula (3), at least one compound selected from a group of compounds represented by Formula (3-1) to Formula (3-11), ##STR00058## in Formula (3-1) to Formula (3-11), R.sup.3 is C1-12 linear alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC; and Y.sup.35 is hydrogen, fluorine, or chlorine.

6. The liquid crystal composition according to claim 1, comprising, as the compound represented by Formula (4), at least one compound selected from a group of compounds represented by Formula (4-1) to Formula (4-7), ##STR00059## in Formula (4-1) to Formula (4-7), R.sup.4 is C1-12 linear alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC; L.sup.44 and L.sup.45 are hydrogen, fluorine, chlorine, methyl, or ethyl; and Y.sup.41 is hydrogen, fluorine, or chlorine, in Formula (4-1), Formula (4-6), and Formula (4-7), at least one of L.sup.44, L.sup.45, and Y.sup.41 is not hydrogen.

7. The liquid crystal composition according to claim 1, wherein, based on a weight of the liquid crystal composition, a proportion of the compound represented by Formula (1) is in a range from 15 weight % to 65 weight %, a proportion of the compound represented by Formula (2) is in a range from 5 weight % to 40 weight %, a proportion of the compound represented by Formula (3) is in a range from 10 weight % to 55 weight %, a proportion of the compound represented by Formula (4) is in a range from 5 weight % to 20 weight %.

8. The liquid crystal composition according to claim 1, further comprising at least one compound selected from compounds represented by Formula (5), compounds represented by Formula (6), and compounds represented by Formula (7), ##STR00060## in Formula (5) to Formula (7), R.sup.5, R.sup.6, R.sup.71, and R.sup.72 are hydrogen, a halogen, or C1-12 alkyl in which at least one CH.sub.2 may be substituted with O or S, at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC, and at least one hydrogen in these groups may be substituted with a halogen; L.sup.51, L.sup.52, L.sup.53, L.sup.61, L.sup.62, L.sup.63, L.sup.64, L.sup.71, L.sup.72, L.sup.73, L.sup.74, L.sup.75, L.sup.76, and L.sup.77 are hydrogen, a halogen, C1-3 alkyl, or C3-5 cycloalkyl; Y.sup.51, Y.sup.52, and Y.sup.61 are hydrogen or a halogen; a ring A 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, and at least one hydrogen on these rings may be substituted with a halogen or C1-3 alkyl; Z.sup.61 and Z.sup.62 are a single bond, CC, or CCCC; and a is 0, 1, or 2, b is 1, 2, or 3, a+b is 3, c and d are 0 or 1, and e is 0, 1, or 2.

9. The liquid crystal composition according to claim 8, comprising, as the compound represented by Formula (5), at least one compound selected from a group of compounds represented by Formula (5-1) to Formula (5-10), ##STR00061## ##STR00062## in Formula (5-1) to Formula (5-10), R.sup.5 is C1-12 alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC; and Y.sup.51 is hydrogen, fluorine, or chlorine.

10. The liquid crystal composition according to claim 8, comprising, as the compound represented by Formula (6), at least one compound selected from a group of compounds represented by Formula (6-1) to Formula (6-8), ##STR00063## in Formula (6-1) to Formula (6-8), R.sup.6 is C1-12 alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC; L.sup.61, L.sup.62, L.sup.63, and L.sup.64 are hydrogen, fluorine, chlorine, methyl, or ethyl; and Y.sup.61 is hydrogen, fluorine, or chlorine.

11. The liquid crystal composition according to claim 8, comprising, as the compound represented by Formula (7), at least one compound selected from a group of compounds represented by Formula (7-1) to Formula (7-6), ##STR00064## in Formula (7-1) to Formula (7-6), R.sup.71 and R.sup.72 are C1-12 alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC; in Formula (7-1) and Formula (7-2), L.sup.75, L.sup.76, and L.sup.77 are hydrogen, fluorine, chlorine, methyl, or ethyl; in Formula (7-3), L.sup.72, L.sup.74, L.sup.75, L.sup.76, and L.sup.77 are hydrogen, fluorine, chlorine, methyl, or ethyl; in Formula (7-4), L.sup.71, L.sup.73, L.sup.75, L.sup.76, and L.sup.77 are hydrogen, fluorine, chlorine, methyl, or ethyl; and in Formula (7-5) and Formula (7-6), L.sup.71, L.sup.72, L.sup.73, L.sup.74, L.sup.75, L.sup.76, and L.sup.77 are hydrogen, fluorine, chlorine, methyl, or ethyl.

12. The liquid crystal composition according to claim 8, wherein, based on a weight of the liquid crystal composition, a proportion of the compound represented by Formula (5) is in a range from 0 weight % to 30 weight %, a proportion of the compound represented by Formula (6) is in a range from 0 weight % to 25 weight %, a proportion of the compound represented by Formula (7) is in a range from 0 weight % to 50 weight %, and a total proportion of these compounds is in a range from 5 weight % to 50 weight %.

13. The liquid crystal composition according to claim 1, wherein a refractive index anisotropy at 25 C. at a wavelength of 589 nm is 0.40 or more.

14. The liquid crystal composition according to claim 1, wherein a dielectric anisotropy at 25 C. at a frequency of 1 kHz is 10 or more.

15. The liquid crystal composition according to claim 1, wherein a dielectric anisotropy at 25 C. at at least one frequency from 1 GHz to 10 THz is in a range from 1.0 to 3.0.

16. The liquid crystal composition according to claim 1, comprising an optically active compound.

17. The liquid crystal composition according to claim 1, comprising a polymerizable compound.

18. 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.

19. 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.

20. 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.

21. A liquid crystal lens comprising the liquid crystal composition according to claim 1.

22. A birefringent lens for stereoscopic image display, comprising the liquid crystal composition according to claim 1.

23. A light modulator comprising the liquid crystal composition according to claim 1.

Description

DESCRIPTION OF THE EMBODIMENTS

(1) Embodiments of the disclosure provide a liquid crystal composition which is well-balanced and excellent in required characteristics described above as a material used in elements for electromagnetic wave control in a frequency range from 1 GHz to 10 THz, and an element including this composition.

(2) Terms used in this specification are as follows. The terms liquid crystal composition and electromagnetic wave control element are respectively sometimes abbreviated as composition and element. Electromagnetic wave control element is a general term for an electromagnetic wave control panel and an electromagnetic wave control module. Liquid crystalline compound is a general term for a compound having a liquid crystal phase such as a nematic phase or a smectic phase and a compound which does not have a liquid crystal phase but is mixed into a composition for the purpose of adjusting the characteristics such as dielectric anisotropy, a viscosity, and a temperature range of a liquid crystal phase. This compound has, for example, a 6-membered ring such as 1,4-cyclohexylene or 1,4-phenylene, and its molecules (liquid crystal molecules) are rod-like. Polymerizable compound is a compound added for the purpose of forming a polymer in a composition. A liquid crystalline compound having alkenyl is not classified as a polymerizable compound in that sense.

(3) A liquid crystal composition is prepared by mixing a plurality of liquid crystalline compounds. The proportion (content) of the liquid crystalline compounds is represented by weight percentage (weight %) based on the weight of this liquid crystal composition. Additives such as an optically active compound, an antioxidant, an ultraviolet absorber, a stabilizer against ultraviolet rays or heat, a quencher, dyes (dichroic dyes), a defoamer, a polymerizable compound, a polymerization initiator, a polymerization inhibitor, an antistatic agent, and a magnetic compound are added to this liquid crystal composition as necessary. The proportion (addition amount) of the additives is represented by weight percentage (weight %) based on the weight of the liquid crystal composition similarly to the proportion of the liquid crystalline compounds. Parts per million (ppm) by weight are sometimes used. The proportions of a polymerization initiator and a polymerization inhibitor are exceptionally expressed based on the weight of the polymerizable compounds.

(4) Upper limit temperature of a nematic phase is sometimes abbreviated as upper limit temperature. Lower limit temperature of a nematic phase is sometimes abbreviated as lower limit temperature. An expression increasing dielectric anisotropy means that the value increases positively in the case of a composition with a positive dielectric anisotropy, and means that the value increases negatively in the case of a composition with a negative dielectric anisotropy.

(5) At least one compound selected from the group consisting of compounds represented by Formula (1) is sometimes abbreviated as compounds (1). Compounds (1) mean one or more compounds represented by Formula (1). The same applies to compounds represented by other formulae. At least one relating to may be substituted means that not only a position but also the number thereof may be selected without limitation.

(6) ##STR00017##

(7) The above-described compound (1z) will be described as an example. In Formula (1z), the symbols and surrounded by hexagons correspond to a ring and a ring , respectively, and represent rings such as six-membered rings and condensed rings. When the subscript x is 2, there are two rings . Two groups represented by two rings may be the same as or different from each other. This rule applies to a plurality of rings when the subscript x is greater than 2. This rule also applies to other symbols such as a bonding group Z. The slash across one side of the ring indicates that any hydrogen on the ring may be substituted with a substituent (-Sp-P). The subscript y indicates the number of substituents substituted. When the subscript y is 0, there is no such substitution. When the subscript y is 2 or more, there are a plurality of substituents (-Sp-P) on the ring . The rule that they may be the same as or different from each other also applies to this case. This rule also applies to a case where the symbol Ra is used for a plurality of compounds.

(8) In Formula (1z), for example, an expression such as Ra and Rb are alkyl, alkoxy, or alkenyl means that Ra and Rb are independently selected from the group consisting of alkyl, alkoxy, and alkenyl. Here, a group represented by Ra and a group represented by Rb may be the same as or different from each other. This rule also applies to a case where the symbol Ra is used for a plurality of compounds. This rule also applies to a case where a plurality of Ra's is used for one compound.

(9) At least one compound selected from compounds represented by Formula (1z) is sometimes abbreviated as compound (1z). Compounds (1z) mean one compound represented by Formula (1z), a mixture of two compounds thereof, or a mixture of three or more compounds thereof. The same applies to compounds represented by other formulae. An expression at least one compound selected from compounds represented by Formula (1z) and Formula (2z) means at least one compound selected from the group consisting of compounds (1z) and compounds (2z).

(10) An expression at least one A means that the number of As is any number. An expression at least one A may be substituted with B means that the position of A is any position when the number of As is 1, and the positions of As can be selected without limitation even when the number of As is 2 or more. An expression at least one CH.sub.2 may be substituted with O is sometimes used. In this case, CH.sub.2CH.sub.2CH.sub.2 may be converted to OCH.sub.2O by substituting non-adjacent CH.sub.2 with O. However, adjacent CH.sub.2 is not substituted with O. This is because OOCH.sub.2 (peroxide) would be produced by this substitution.

(11) In the case of being simply described as alkyl, alkyl in a liquid crystalline compound is linear alkyl or branched alkyl and does not include cycloalkyl unless otherwise specified. For example, C1-12 alkyl refers to C1-12 linear alkyl or branched alkyl. Linear alkyl is preferable over branched alkyl. The same applies to terminal groups such as alkoxy and alkenyl. The configuration of 1,4-cyclohexylene is preferably trans rather than cis to increase the upper limit temperature. 2-fluoro-1,4-phenylene means two divalent groups below. In the chemical formulae, fluorine may be directed leftward (L) or rightward (R). This rule also applies to divalent groups of asymmetric rings such as 2,5-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, and tetrahydropyran-2,5-diyl. Preferable tetrahydropyran-2,5-diyl is directed rightward (R) to increase the upper limit temperature.

(12) ##STR00018##

(13) A bonding group such as carbonyloxy may similarly be COO or OCO.

(14) In chemical formulae of component compounds, the symbol R.sup.1 for a terminal group is used for a plurality of compounds. In these compounds, any two groups represented by R.sup.1 may be the same as or different from each other. For example, there is a case where R.sup.1 of a compound (1-1) is methyl and R.sup.1 of a compound (1-2) is ethyl. There is also a case where R.sup.1 of the compound (1-1) is ethyl and R.sup.1 of the compound (1-2) is propyl. This rule also applies to symbols such as R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.71, and R.sup.72.

(15) The disclosure also includes the following items. (a) The above-described composition further containing at least one selected from additives such as an optically active compound, an antioxidant, an ultraviolet absorber, a stabilizer against ultraviolet rays or heat, a quencher, dyes (dichroic dyes), a defoamer, a polymerizable compound, a polymerization initiator, a polymerization inhibitor, an antistatic agent, and a magnetic compound. (b) An element containing the above-described composition. (c) An element containing the above-described composition and used for controlling electromagnetic wave signals at any frequency from 1 GHz to 10 THz. (d) The above-described composition further containing a polymerizable compound, and an element containing this composition. (e) Use of the above-described composition as a composition having a nematic phase. (f) Use of an optically active composition obtained by adding an optically active compound to the above-described composition.

(16) The liquid crystal composition of the disclosure has a large dielectric anisotropy and a small dielectric loss tangent (tan ) at 28 GHz. Generally, in a frequency domain of electromagnetic wave signals in a range from 1 GHz to 10 THz, it is known that liquid crystal materials no longer receive contributions from orientational polarization and only receive contributions from ionic polarization and electronic polarization, and the dielectric anisotropy and the dielectric loss tangent is constant. In other words, being capable of being regarded as having a large dielectric anisotropy and a small dielectric loss tangent in the frequency domain of electromagnetic wave signals in the range from 1 GHz to 10 THz, the liquid crystal composition of the disclosure can be suitably used for elements related to electromagnetic waves in the range from 1 GHz to 10 THz.

(17) The composition of the disclosure will be described in the following order. First, configurations of component compounds in the composition will be described. Second, the main characteristics of the component compounds and the main effects of these compounds on the composition will be described. Third, combinations of components in the composition, preferable proportions of the components, and reasons thereof will be described. Fourth, preferable embodiments of the component compounds will be described. Fifth, preferable component compounds will be shown. Sixth, additives which may be added to the composition will be described. Seventh, methods for synthesizing component compounds will be described. Finally, uses of the composition will be described.

(18) First, configurations of component compounds in the composition will be described. The composition of the disclosure is classified into a composition A and a composition B. The composition A contains liquid crystalline compounds selected from a compound (1), a compound (2), a compound (3), a compound (4), a compound (5), a compound (6), and a compound (7), and may further contain other liquid crystalline compounds, additives, etc. Other liquid crystalline compounds are liquid crystalline compounds different from the compound (1), the compound (2), the compound (3), the compound (4), the compound (5), the compound (6), and the compound (7). Such compounds are mixed into the composition for the purpose of further adjusting characteristics. To adjust a liquid crystal composition having a desired refractive index anisotropy or a dielectric anisotropy at high frequencies, it is preferable not to use liquid crystalline compounds with a small refractive index anisotropy, such as one-ring compounds or two-ring compounds without bonding groups, as other liquid crystalline compounds. The additives include an optically active compound, an antioxidant, an ultraviolet absorber, a stabilizer against ultraviolet rays or heat, a quencher, dyes (dichroic dyes), a defoaming agent, a polymerizable compound, a polymerization initiator, a polymerization inhibitor, an antistatic agent, a polar compound, etc.

(19) The composition B consists substantially of the liquid crystalline compound selected from the compound (1), the compound (2), the compound (3), the compound (4), the compound (5), the compound (6), and the compound (7). Substantially means that the composition may contain additives, but does not contain other liquid crystalline compounds. The composition B has fewer components than the composition A. The composition B is preferable over the composition A from the viewpoint of cost reduction. The composition A is preferable over the composition B from the viewpoint that its characteristics can be further adjusted by incorporating other liquid crystalline compounds.

(20) Second, the main characteristics of the component compounds and the main effects of these compounds on the characteristics of the composition will be described. The main characteristics of the component compounds are summarized in Table 1 based on the effects of the disclosure. Regarding the symbols in Table 1, L means large or high, M means medium, and S means small or low. The symbols L, M, and S are classifications based on qualitative comparisons among the component compounds, and 0 (zero) means that the value is approximately zero or close to zero.

(21) TABLE-US-00001 TABLE 1 Characteristics of compounds Compound (1) (2) (3) (4) (5) (6) (7) Upper limit S S to L L M to L M L S to L temperature Viscosity S M to L M M to L S to L S to M M Refractive M M M to L L S L M to L index anisotropy Dielectric M M M M M M to L 0 anisotropy

(22) The main effects of the component compounds on the characteristics of the composition when the component compounds are mixed in the composition are as follows.

(23) The compound (1) mainly has the effects of increasing the refractive index anisotropy of the liquid crystal composition, increasing the dielectric anisotropy, and reducing the viscosity. From the viewpoint of reducing the viscosity, the number of substituents is preferably 1. By controlling the number of substituents on the benzene ring of the compound (1), the upper limit temperature and the lower limit temperature are controllable to some extent. In other words, upon decreasing the number of substituents, the upper limit temperature and the lower limit temperature tend to increase. Upon increasing the number of substituents, the upper limit temperature and the lower limit temperature tend to decrease. From the viewpoint of lowering the lower limit temperature of the liquid crystal composition, the number of substituents is preferably 1 or 2.

(24) The compound (2) mainly has the effects of increasing the refractive index anisotropy of the liquid crystal composition, increasing the dielectric anisotropy, and lowering tan at high frequencies. The relationship between the number of substituents on the benzene ring and the upper limit temperature and the lower limit temperature is similar to that in the compound (1), and from the viewpoint of lowering the lower limit temperature of the liquid crystal composition, the number of substituents is preferably 1 or 2.

(25) The compound (3) mainly has the effects of increasing the refractive index anisotropy of the liquid crystal composition, increasing the dielectric anisotropy, and raising the upper limit temperature. The relationship between the number of substituents on the benzene ring and the upper limit temperature and the lower limit temperature is similar to that in the compound (1), and from the viewpoint of lowering the lower limit temperature of the liquid crystal composition, the number of substituents is preferably 2 or 3.

(26) The compound (4) mainly has the effects of significantly increasing the refractive index anisotropy of the liquid crystal composition and increasing the dielectric anisotropy. The relationship between the number of substituents on the benzene ring and the upper limit temperature and the lower limit temperature is similar to that in the compound (1), and from the viewpoint of lowering the lower limit temperature of the liquid crystal composition, the number of substituents is preferably a larger number, and particularly preferably 2 or 3.

(27) The compound (5) mainly has the effects of increasing the dielectric anisotropy of the liquid crystal composition, lowering tan at high frequencies, and reducing the viscosity. The relationship between the number of substituents on the benzene ring and the upper limit temperature and the lower limit temperature is similar to that in the compound (1), and from the viewpoint of lowering the lower limit temperature of the liquid crystal composition, the number of substituents is preferably 1 or 2.

(28) The compound (6) mainly has the effects of increasing the refractive index anisotropy of the liquid crystal composition, increasing the dielectric anisotropy, and raising the upper limit temperature. From the viewpoint of increasing the refractive index anisotropy, a being 0 and b being 3 are preferable. From the viewpoint of raising the upper limit temperature and lowering the lower limit temperature, a being 1 and b being 2 are preferable. The relationship between the number of substituents on the benzene ring and the upper limit temperature and the lower limit temperature is similar to that in the compound (1), and from the viewpoint of lowering the lower limit temperature of the liquid crystal composition, the number of substituents is preferably 3 or 4.

(29) The compound (7) mainly has the effects of increasing the refractive index anisotropy while expanding the temperature range of the nematic phase. The relationship between the number of rings (c in Formula (7)) included in the compound and the upper limit temperature and the viscosity is as follows: when c is 0, the upper limit temperature and the viscosity tend to be low, and when c is 1, the upper limit temperature and the viscosity tend to be high.

(30) Third, combinations of components in the composition, preferable proportions of component compounds, and reasons thereof will be described. The preferable combination of components in the composition is: compound (1)+compound (2)+compound (3)+compound (4), compound (1)+compound (2)+compound (3)+compound (4)+compound (5), compound (1)+compound (2)+compound (3)+compound (4)+compound (6), compound (1)+compound (2)+compound (3)+compound (4)+compound (7), or compound (1)+compound (2)+compound (3)+compound (4)+compound (6)+compound (7). The particularly preferable combination is compound (1)+compound (2)+compound (3)+compound (4), from the viewpoint of increasing the refractive index anisotropy and the dielectric anisotropy and reducing the viscosity.

(31) Based on the weight of the liquid crystal composition, the preferable proportion of the compound (1) is in a range from about 15 weight % to about 65 weight % to increase the refractive index anisotropy and increase in the high frequency domain, while expanding the temperature range of the nematic phase and reducing the viscosity. A more preferable proportion is in a range from about 15 weight % to about 60 weight %. A particularly preferable proportion is in a range from about 15 weight % to about 55 weight %.

(32) Based on the weight of the liquid crystal composition, the preferable proportion of the compound (2) is in a range from about 5 weight % to about 40 weight % to increase the refractive index anisotropy, maintain a large in the high frequency domain, and reduce tan in the high frequency domain, while expanding the temperature range of the nematic phase. A more preferable proportion is in a range from about 7 weight % to about 35 weight %. A particularly preferable proportion is in a range from about 10 weight % to about 30 weight %.

(33) Based on the weight of the liquid crystal composition, the preferable proportion of the compound (3) is in a range from about 10 weight % to about 55 weight % to increase the refractive index anisotropy and increase in the high frequency domain, while expanding the temperature range of the nematic phase. A more preferable proportion is in a range from about 12 weight % to about 50 weight %. A particularly preferable proportion is in a range from about 15 weight % to about 45 weight %.

(34) Based on the weight of the liquid crystal composition, the preferable proportion of the compound (4) is in a range from about 5 weight % to about 20 weight % to increase the refractive index anisotropy and increase in the high frequency domain, while expanding the temperature range of the nematic phase. A more preferable proportion is in a range from about 7 weight % to about 15 weight %.

(35) Based on the weight of the liquid crystal composition, the preferable proportion of the compound (5) is in a range from about 0 weight % to about 30 weight % to increase the refractive index anisotropy, maintain a large in the high frequency domain, reduce tan in the high frequency domain, while expanding the temperature range of the nematic phase. A more preferable proportion is in a range from about 0 weight % to about 25 weight %. A particularly preferable proportion is in a range from about 0 weight % to about 20 weight %.

(36) Based on the weight of the liquid crystal composition, the preferable proportion of the compound (6) is in a range from about 0 weight % to about 25 weight % to increase the refractive index anisotropy and increase in the high frequency domain, while expanding the temperature range of the nematic phase. A more preferable proportion is in a range from about 0 weight % to about 20 weight %. A particularly preferable proportion is in a range from about 0 weight % to about 15 weight %.

(37) Based on the weight of the liquid crystal composition, the preferable proportion of the compound (7) is about 0 weight % or more to increase the refractive index anisotropy and reduce the viscosity, while expanding the temperature range of the nematic phase, and is about 50 weight % or less to increase the dielectric anisotropy. A more preferable proportion is in a range from about 0 weight % to about 40 weight %. A particularly preferable proportion is in a range from about 0 weight % to about 30 weight %.

(38) Fourth, preferable embodiments of the component compounds will be described.

(39) R.sup.1, R.sup.2, R.sup.3, and, R.sup.4 are hydrogen, a halogen, or C1-12 linear alkyl in which at least one-CH.sub.2 may be substituted with O or S, at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC, and at least one hydrogen in these groups may be substituted with a halogen.

(40) Preferable R.sup.1, R.sup.2, R.sup.3, or R.sup.4 is methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, or ethoxy to increase stability against ultraviolet rays or heat. To reduce the viscosity, methyl, ethyl, propyl, butyl, pentyl, methoxy, or ethoxy is preferable.

(41) R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are C1-12 linear alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC.

(42) R.sup.5, R.sup.6, R.sup.71, and R.sup.72 are hydrogen, a halogen, or C1-12 alkyl in which at least one CH.sub.2 may be substituted with O or S, at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC, and at least one hydrogen in these groups may be substituted with a halogen.

(43) Preferable R.sup.5, R.sup.6, R.sup.71, or R.sup.72 is methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, or ethoxy to increase stability against ultraviolet rays or heat. To reduce the viscosity, methyl, ethyl, propyl, butyl, pentyl, methoxy, or ethoxy is preferable.

(44) R.sup.5, R.sup.6, R.sup.71, and R.sup.72 are C1-12 alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC.

(45) a is 0, 1, or 2, b is 1, 2, or 3, and a+b is 3. Preferable a is 0 to increase the refractive index anisotropy, and is 1 to raise the upper limit temperature and lower the lower limit temperature. Preferable b is 1 to raise the upper limit temperature, and is 3 to increase the refractive index anisotropy.

(46) c and d are 0 or 1, and e is 0, 1, or 2. Preferable c is 0 to lower the lower limit temperature and reduce the viscosity, and is 1 to increase the refractive index anisotropy and raise the upper limit temperature. Preferable d is 0 to reduce the viscosity, and is 1 to increase the refractive index anisotropy. Preferable e is 1 to increase the refractive index anisotropy, and is 2 to further increase the refractive index anisotropy.

(47) Z.sup.61 and Z.sup.62 are a single bond, CC, or CCCC. Preferable Z.sup.61 or Z.sup.62 is a single bond to reduce the viscosity, and is CC or CCCC to increase the refractive index anisotropy.

(48) A ring A 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, and at least one hydrogen on these rings may be substituted with a halogen or C1-3 alkyl.

(49) A preferable ring A is 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, or 1,3-dioxane-2,5-diyl. The ring A is more preferably 1,4-cyclohexylene.

(50) L.sup.11, L.sup.12, L.sup.13, L.sup.21, L.sup.22, L.sup.23, L.sup.31, L.sup.32, L.sup.33, L.sup.41, L.sup.42, L.sup.43, L.sup.44, L.sup.45, L.sup.51, L.sup.52, L.sup.53, L.sup.61, L.sup.62, L.sup.63, L.sup.64, L.sup.71, L.sup.72, L.sup.73, L.sup.74, L.sup.75, L.sup.76, and L.sup.77 are hydrogen, a halogen, C1-3 alkyl, or C3-5 cycloalkyl. Preferable L.sup.11, L.sup.12, L.sup.13, L.sup.21, L.sup.22, L.sup.23, L.sup.31, L.sup.32, L.sup.33, L.sup.41, L.sup.42, L.sup.43, L.sup.44, L.sup.45, L.sup.51, L.sup.52, L.sup.53, L.sup.61, L.sup.62, L.sup.63, L.sup.64, L.sup.71, L.sup.72, L.sup.73, L.sup.74, L.sup.75, L.sup.76, or L.sup.77 is hydrogen to raise the upper limit temperature, is fluorine or chlorine to increase the dielectric anisotropy, and is fluorine, chlorine, methyl, or ethyl to lower the lower limit temperature.

(51) L.sup.44, L.sup.45, L.sup.61, L.sup.62, L.sup.63, L.sup.64, L.sup.71, L.sup.72, L.sup.73, L.sup.74, L.sup.75, L.sup.76, and L.sup.77 are hydrogen, fluorine, chlorine, methyl, or ethyl.

(52) Y.sup.11, Y.sup.21, Y.sup.22, Y.sup.23, Y.sup.31, Y.sup.32, Y.sup.33, Y.sup.34, Y.sup.35, Y.sup.36, Y.sup.41, Y.sup.51, Y.sup.52, and Y.sup.61 are hydrogen or a halogen. Preferable Y.sup.11, Y.sup.21, Y.sup.22, Y.sup.23, Y.sup.31, Y.sup.32, Y.sup.33, Y.sup.34, Y.sup.35, Y.sup.36, Y.sup.41, Y.sup.51, Y.sup.52, or Y.sup.61 is hydrogen to increase the refractive index anisotropy, and is fluorine or chlorine to increase the dielectric anisotropy and lower the lower limit temperature.

(53) Y.sup.21, Y.sup.22, Y.sup.35, Y.sup.51 and Y.sup.61 are hydrogen, fluorine, or chlorine.

(54) In Formula (1), at least one of L.sup.11, L.sup.12, and L.sup.13 is C1-3 alkyl. Preferably, to lower the lower limit temperature, at least one of L.sup.11, L.sup.12, and L.sup.13 is methyl.

(55) In Formula (3), at least one of L.sup.31, L.sup.32, and L.sup.33 is C1-3 alkyl. Preferably, to lower the lower limit temperature, at least one of L.sup.31, L.sup.32, and L.sup.33 is methyl.

(56) In Formula (4), to lower the lower limit temperature, at least two of L.sup.41, L.sup.42, L.sup.43, L.sup.44, L.sup.45, and Y.sup.41 are preferably not hydrogen, and at least two of L.sup.41, L.sup.42, L.sup.43, L.sup.44, L.sup.45, and Y.sup.41 are more preferably fluorine or methyl.

(57) To increase the dielectric anisotropy of the entire liquid crystal composition, it is preferable that L.sup.11 and L.sup.12, L.sup.13 and Y.sup.11, L.sup.21 and L.sup.22, L.sup.23 and Y.sup.23, Y.sup.33 and Y.sup.35, L.sup.31 and L.sup.32, L.sup.33 and Y.sup.36, L.sup.41 and L.sup.42, L.sup.45 and Y.sup.41, L.sup.51 and L.sup.52, L.sup.53 and Y.sup.52, L.sup.72 and L.sup.73, L.sup.75 and L.sup.76, L.sup.S1 and L.sup.S2, or L.sup.S3 and Y.sup.S1 are not simultaneously a halogen.

(58) The liquid crystal composition of the disclosure preferably does not contain compounds represented by Formula(S), from the viewpoint of having a nematic phase over a wide temperature range.

(59) In Formula(S), R.sup.S1 is hydrogen, a halogen, or C1-12 alkyl in which at least one CH.sub.2 may be substituted with O or S, at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC, and at least one hydrogen in these groups may be substituted with a halogen; L.sup.S1, L.sup.S2, and L.sup.S3 are hydrogen or fluorine; and Y.sup.S1 is hydrogen or fluorine.

(60) The liquid crystal composition of the disclosure preferably does not contain compounds represented by Formula (T), from the viewpoint of having a high voltage holding ratio for TFT driving.

(61) In Formula (T), R.sup.T1 is hydrogen, a halogen, or C1-12 alkyl in which at least one CH.sub.2 may be substituted with O or S, at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC, and at least one hydrogen in these groups may be substituted with a halogen; Y.sup.T1 and Y.sup.T2 are hydrogen or fluorine; and t is 0 or 1.

(62) Fifth, preferable component compounds will be shown.

(63) The preferable compounds (1) include a compound (1-1) to a compound (1-10).

(64) ##STR00019## ##STR00020##

(65) In Formula (1-1) to Formula (1-10),

(66) R.sup.1 is C1-12 linear alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC.

(67) At least one of the compounds (1) is more preferably the compound (1-7) or the compound (1-8).

(68) The preferable compounds (2) include a compound (2-1) to a compound (2-10).

(69) ##STR00021## ##STR00022##

(70) In Formula (2-1) to Formula (2-10), R.sup.2 is C1-12 linear alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC; Y.sup.22 is hydrogen, fluorine, or chlorine; and in Formula (2-10), Y.sup.21 is hydrogen, fluorine, or chlorine.

(71) At least one of the compounds (2) is more preferably the compound (2-2), the compound (2-5), or the compound (2-6).

(72) The preferable compounds (3) include a compound (3-1) to a compound (3-11).

(73) ##STR00023## ##STR00024##

(74) In Formula (3-1) to Formula (3-11), R.sup.3 is C1-12 linear alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC; and Y.sup.35 is hydrogen, fluorine, or chlorine.

(75) At least one of the compounds (3) is more preferably the compound (3-1), the compound (3-2), the compound (3-3), the compound (3-4), or the compound (3-5), and is particularly preferably the compound (3-1), the compound (3-2), or the compound (3-4).

(76) The preferable compounds (4) include a compound (4-1) to a compound (4-7).

(77) ##STR00025##

(78) In Formula (4-1) to Formula (4-7), R.sup.4 is C1-12 linear alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCHor CC; L.sup.44 and L.sup.45 are hydrogen, fluorine, chlorine, methyl, or ethyl; and Y.sup.41 is hydrogen, fluorine, or chlorine.

(79) At least one of the compounds (4) is more preferably the compound (4-2).

(80) The preferable compounds (5) include a compound (5-1) to a compound (5-10).

(81) ##STR00026## ##STR00027##

(82) In Formula (5-1) to Formula (5-10), R.sup.5 is C1-12 alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC; and Y.sup.51 is hydrogen, fluorine, or chlorine.

(83) At least one of the compounds (5) is more preferably the compound (5-2), the compound (5-6), or the compound (5-7).

(84) The preferable compounds (6) include a compound (6-1) to a compound (6-8).

(85) ##STR00028##

(86) In Formula (6-1) to Formula (6-8), R.sup.6 is C1-12 alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC; L.sup.61, L.sup.62, L.sup.63, and L.sup.64 are hydrogen, fluorine, chlorine, methyl, or ethyl; and Y.sup.61 is hydrogen, fluorine, or chlorine.

(87) At least one of the compounds (6) is more preferably the compound (6-4), the compound (6-6), the compound (6-7), or the compound (6-8).

(88) The preferable compounds (7) include a compound (7-1) to a compound (7-6).

(89) ##STR00029##

(90) In Formula (7-1) to Formula (7-6), R.sup.71 and R.sup.72 are C1-12 alkyl in which at least one (CH.sub.2).sub.2 may be substituted with CHCH or CC; in Formula (7-1) and Formula (7-2), L.sup.75, L.sup.76, and L.sup.77 are hydrogen, fluorine, chlorine, methyl, or ethyl; in Formula (7-3), L.sup.72, L.sup.74, L.sup.75, L.sup.76, and L.sup.77 are hydrogen, fluorine, chlorine, methyl, or ethyl; in Formula (7-4), L.sup.71, L.sup.73, L.sup.75, L.sup.76, and L.sup.77 are hydrogen, fluorine, chlorine, methyl, or ethyl; and in Formula (7-5) and Formula (7-6), L.sup.71, L.sup.72, L.sup.73, L.sup.74, L.sup.75, L.sup.76, and L.sup.77 are hydrogen, fluorine, chlorine, methyl, or ethyl.

(91) At least one of the compounds (7) is more preferably the compound (7-1), the compound (7-2), the compound (7-3), the compound (7-4), or the compound (7-6). At least two of the compounds (7) are particularly preferably a combination of the compound (7-1) and the compound (7-4), the compound (7-1) and the compound (7-6), the compound (7-2) and the compound (7-4), or the compound (7-2) and the compound (7-6).

(92) Sixth, additives which may be added to the composition will be described. Such additives include an optically active compound, an antioxidant, an ultraviolet absorber, a stabilizer against ultraviolet rays or heat, a quencher, dyes (dichroic dyes), a defoamer, a polymerizable compound, a polymerization initiator, a polymerization inhibitor, an antistatic agent, a polar compound, etc. Hereinafter, the mixing proportion of these additives will be a proportion (weight) based on the weight of the liquid crystal composition unless otherwise specified.

(93) Any combination of additives may be used, and for example, it is also possible to use a combination of different types of antioxidants. For example, it is also possible to use a combination of different types of additives, for example, a combination of an antioxidant, an ultraviolet absorber, and a stabilizer.

(94) An optically active compound is added to the composition for the purpose of inducing a helical structure of liquid crystals to give a twist angle. Examples of such a compound include a compound (8-1) to a compound (8-5). A preferable proportion of the optically active compound is about 5 weight % or less. A more preferable proportion thereof is in a range from about 0.01 weight % to about 2 weight %.

(95) ##STR00030##

(96) To prevent a decrease in specific resistance due to heating in atmospheric air or to maintain a large voltage holding ratio not only at room temperature but also at temperatures close to the upper limit temperature after long-term use of an element, an antioxidant is added to the composition. Preferable examples of the antioxidant include a compound (9) in which t is an integer of 1 to 9.

(97) ##STR00031##

(98) In the compound (9), tis preferably 1, 3, 5, 7, or 9. t is more preferably 7. Since the compound (9) in which t is 7 has low volatility, it is effective to maintain a large voltage holding ratio not only at room temperature but also at temperatures close to the upper limit temperature after long-term use of an element. A preferable proportion of the antioxidant is about 50 ppm or higher to obtain its effect, and is about 600 ppm or lower so as not to lower the upper limit temperature or raise the lower limit temperature. A more preferable proportion thereof is in a range from about 100 ppm to about 300 ppm.

(99) Preferable examples of the ultraviolet absorber include benzophenone derivatives, benzoate derivatives, triazole derivatives, etc. Light stabilizers such as sterically hindered amines are also preferable. Preferable examples of the light stabilizer include a compound (10-1) to a compound (10-16). A preferable proportion of such an absorber or stabilizer is about 50 ppm or higher to obtain its effect, and is about 10,000 ppm or lower so as not to lower the upper limit temperature or raise the lower limit temperature. A more preferable proportion thereof is in a range from about 100 ppm to about 10,000 ppm.

(100) ##STR00032## ##STR00033##

(101) Additives preferable as the stabilizer against ultraviolet rays or heat include amino-tolane compounds represented by a compound (11) (U.S. Pat. No. 6,495,066B).

(102) ##STR00034##

(103) In Formula (11), R.sup.m and R.sup.n are C1-12 alkyl, C1-12 alkoxy, C2-12 alkenyl, or C2-12 alkenyloxy; X.sup.a is NO.sub.2, CN, NCS, fluorine, or OCF.sub.3; and Y.sup.a and Y.sup.b are hydrogen or fluorine. A preferable proportion of such stabilizers is in a range from 1 to 20 weight % and more preferably in a range from 5 to 10 weight % to obtain their effects.

(104) A quencher is a compound that receives light energy absorbed by a liquid crystalline compound and converts it to heat energy to prevent decomposition of a liquid crystalline compound. A preferable proportion of such a quencher is about 50 ppm or higher to obtain its effect, and is about 20,000 ppm or lower to lower the lower limit temperature. A more preferable proportion thereof is in a range from about 100 ppm to about 10,000 ppm.

(105) Dichroic dyes such as azo dyes and anthraquinone dyes are added to the composition to make it suitable for guest host (GH) mode elements. A preferable proportion of the dyes is in a range from about 0.01 weight % to about 10 weight %. A defoamer such as dimethyl silicone oil and methylphenyl silicone oil are added to the composition to prevent foaming. A preferable proportion of the defoamer is about 1 ppm or higher to obtain its effect, and is about 1,000 ppm or lower to prevent display defects. A more preferable proportion thereof is in a range from about 1 ppm to about 500 ppm.

(106) A polymerizable compound is added to the composition to make it suitable for polymer-stabilized elements. Preferable examples of the polymerizable compound include compounds having polymerizable groups such as acrylates, methacrylates, vinyl compounds, vinyloxy compounds, propenyl ethers, epoxy compounds (oxiranes and oxetanes), and vinyl ketone. More preferable examples include derivatives of acrylates or methacrylates. A preferable proportion of the polymerizable compound is about 0.05 weight % or more to obtain its effect, and is about 20 weight % or less to prevent an increase in driving temperature. A more preferable proportion thereof is in a range from about 0.1 weight % to about 10 weight %. The polymerizable compound is polymerized through ultraviolet irradiation. Polymerization may be carried out in the presence of a polymerization initiator such as a photopolymerization initiator. Suitable conditions for polymerization, suitable types of initiators, and suitable amounts thereof are known to those skilled in the art and described in documents. For example, photopolymerization initiators Irgacure 651 (registered trademark; BASF), Irgacure 184 (registered trademark; BASF), or Darocur 1173 (registered trademark; BASF) is suitable for radical polymerization. A preferable proportion of the photopolymerization initiator is in a range from about 0.1 parts by weight to about 5 parts by weight based on 100 parts by weight of the polymerizable compound. A more preferable proportion thereof is in a range from about 1 part by weight to about 3 parts by weight.

(107) A polymerization inhibitor may be added to prevent polymerization during storage of a polymerizable compound. A polymerizable compound is generally added to the composition without removing a polymerization inhibitor. Examples of the polymerization inhibitor include hydroquinone, hydroquinone derivatives such as methylhydroquinone, 4-tert-butylcatechol, 4-methoxyphenol, and phenothiazine.

(108) A polar compound in this specification is an organic compound having polarity and does not include a compound having an ionic bond. Atoms such as oxygen, sulfur, and nitrogen are more electronegative and tend to have a partial negative charge. Carbon and hydrogen tend to be neutral or have a partial positive charge. Polarity results from uneven distribution of partial charges between different atoms in a compound. For example, the polar compound has at least one substructure such as OH, COOH, SH, NH.sub.2, >NH, and >N.

(109) Seventh, methods for synthesizing component compounds will be described. A synthesis method for the compound (1) will be described in the section of Examples. Other compounds may be synthesized according to methods described in publications such as Organic Synthesis (John Wiley & Sons, Inc.), Organic Reactions (John Wiley & Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press), and New Experimental Chemistry Course (Maruzen). Compositions are prepared according to conventional methods from the compounds obtained in this manner. For example, the component compounds are mixed, and dissolved together by heating.

(110) Finally, use of the composition will be described. Since the composition of the disclosure has a lower limit temperature of about 10 C. or lower and an upper limit temperature of about 70 C. or higher, the composition of the disclosure may be used not only as a composition having a nematic phase, but also used as an optically active composition upon adding an optically active compound.

(111) An oriented liquid crystal composition has different dielectric constants in a vertical direction and a horizontal direction. For this reason, it has a characteristic of dielectric anisotropy.

(112) Not only antenna elements but also elements using a liquid crystal composition are generally elements which are formed by sandwiching a liquid crystal composition as a layer between two substrates, and in which liquid crystal molecules are aligned (oriented) in one direction due to orientation films at interfaces. In the case where there is no external field, liquid crystal molecules in an element are aligned in one direction due to orientation control force of the orientation films. However, when an external field is applied, the liquid crystal molecules in the element deviate from the alignment of the orientation films and face the direction of the external field. In addition, when the external field is removed again, the liquid crystal molecules return to their original states of being aligned in one direction due to the orientation control force of the orientation films. In this manner, the orientation of the liquid crystal molecules in the element can be controlled by the orientation and size of the external field, thereby controlling the inclination (angle) of the liquid crystal molecules in the element with respect to the one direction. Since the liquid crystal composition has dielectric anisotropy, it is possible to control the dielectric constant of the layer of liquid crystal composition in the element with respect to the one direction by controlling the angle of the liquid crystal molecules in the element with respect to the one direction. For example, if the dielectric constant of a layer of liquid crystal composition in an element in one direction when there is no external field is a dielectric constant in the vertical direction of the liquid crystal composition, an external field can be applied thereto perpendicularly to the one direction to change the dielectric constant to a dielectric constant in the horizontal direction of the liquid crystal composition.

(113) In this manner, the liquid crystal composition of the disclosure may be used in a switching element capable of reversibly controlling a dielectric constant by reversibly changing the orientation direction of liquid crystal molecules.

(114) Angles of liquid crystal molecules in an element can be controlled using an electric field as an external field. A voltage required to drive liquid crystal molecules is a driving voltage. To control angles of liquid crystal molecules, it is required for dielectric anisotropy at 25 C. to be larger than at least 2 in a frequency range below 1 MHz of a liquid crystal composition. To further reduce the driving voltage, it is necessary to increase the dielectric anisotropy at 25 C. in the frequency range below 1 MHz, preferably to 5 or more, and more preferably to 10 or more.

(115) As described above, the larger the refractive index anisotropy (n) in visible light (for example, a wavelength of 589 nm), the larger the dielectric anisotropy () in the high-frequency domain (a range from microwaves to terahertz waves (approximately 10 THz)). The liquid crystal composition containing the compounds represented by General Formula (1) of the disclosure preferably has a refractive index anisotropy (n) of 0.30 or more at 25 C. In particular, when used for high-frequency applications, n is more preferably 0.40 or more and particularly preferably 0.45 or more.

(116) To control the phase difference in the high-frequency domain, the dielectric anisotropy in the high-frequency domain is preferably 0.5 or more. To perform more suitable phase control, it is necessary to increase the dielectric anisotropy in the high-frequency domain. To perform sufficient phase control, the dielectric anisotropy is preferably 1.0 or more and more preferably 1.2 or more.

(117) Furthermore, the composition of the disclosure may be used in elements for controlling electromagnetic waves in the frequency range from 1 GHz to 10 THz. Application examples thereof include not only antenna arrays and electromagnetic wave reflectors, but also millimeter-wave variable phase shifters, millimeter-wave radars, etc. Elements utilizing the composition of the disclosure are being developed for various applications and methods. For antenna arrays, antenna arrays applying metamaterial technology are being developed. For electromagnetic wave reflectors, intelligent reflecting surfaces (IRS), reconfigurable intelligent surface (RIS) reflectors, and frequency selective surfaces are being developed.

(118) Elements containing this composition may also be used for applications other than electromagnetic wave control. By reversibly changing the orientation direction of the liquid crystal molecules, not only the dielectric constant but also the refractive index can be controlled. The liquid crystal composition according to the disclosure exhibits a high refractive index anisotropy (n), and thus, the amount of change in refractive index and the amount of phase modulation caused by changing the orientation direction of liquid crystal molecules in visible light and infrared light are large, and can be controlled.

(119) Application example of these characteristic controls include birefringent lenses for stereoscopic image display used as switchable 2D/3D lenses, liquid crystal lenses used for camera focus adjustment, etc. Additionally, it is also possible to use them in spatial light modulators (SLMs) used in electronic holographic displays, and in LiDAR (Light Detection And Ranging) elements, which are distance measuring sensors.

EXAMPLES

(120) The disclosure will be described in more detail with reference to Examples. The disclosure is not limited by these Examples. The disclosure also includes mixtures obtained by mixing at least two compositions of Examples. The synthesized compounds were identified by NMR analysis. The characteristics of the compositions were measured according to methods described below.

(121) NMR analysis: The measurement instrument used was DRX-500 (manufactured by Bruker BioSpin Corporation). For .sup.1H-NMR measurements, the sample was dissolved in a deuterated solvent such as CDCl.sub.3, and the measurement was performed at room temperature, at 500 MHz, with a cumulative count of 16 scans. Tetramethylsilane was used as an internal standard. For .sup.19F-NMR measurements, CFCl.sub.3 was used as an internal standard, and the measurement was performed with a cumulative count of 24 scans. In the description of nuclear magnetic resonance spectra, s means singlet, d means doublet, t means triplet, q means quartet, quin means quintet, sex means sextet, m means multiplet, and br means broad.

(122) Measurement samples: When measuring a phase structure and a transition temperature, the liquid crystalline compound itself was used as the sample. When measuring physical properties such as an upper limit temperature of a nematic phase, a viscosity, an optical anisotropy, a dielectric anisotropy, a composition prepared by mixing the compound with a base liquid crystal was used as the sample.

(123) In the case of using a sample prepared by mixing the compound with a base liquid crystal, the measurement was performed according to the following method. A sample was prepared by mixing 20 weight % of the compound and 80 weight % of the base liquid crystal.

(124) Based on the measured value of this sample, an extrapolated value was calculated according to the extrapolation method expressed by the following equation, and the extrapolated value was recorded. <Extrapolated value>=(100<Measured value of sample><Weight % of base liquid crystal><Measured value of base liquid crystal>)/<Weight % of compound>

(125) Even with this proportion of the compound to the base liquid crystal, in the case where crystals (or smectic phase) precipitated at 25 C., the proportion of the compound to the base liquid crystal was changed in the order of 10 weight %: 90 weight %, 5 weight %: 95 weight %, and 1 weight %: 99 weight %, and the physical properties of the sample were measured at the proportion at which crystals (or smectic phase) no longer precipitated at 25 C. Unless otherwise specified, the proportion of the compound to the base liquid crystal is 20 weight %: 80 weight %.

(126) A base liquid crystal (i) below was used as the base liquid crystal. Proportions of components of the base liquid crystal (i) are shown in weight %.

(127) ##STR00035##

(128) Measurement methods: The characteristics were measured according to the following methods. Most of these were methods described in Japan Electronics and Information Technology Industries Association (hereinafter referred to as JEITA) standards (JEITAED-2521B) deliberated and established by the JEITA, or modified methods thereof. A thin film transistor (TFT) was not attached to a TN element used for the measurement.

(129) Upper Limit Temperature (NI; C.) of Nematic Phase:

(130) A sample was placed on a hot plate of a melting-point measurement apparatus including a polarizing microscope, and heated at a rate of 1 C./min. The temperature was measured when a part of the sample changed from the nematic phase to an isotropic liquid.

(131) Lower Limit Temperature (T.sub.C; C.) of Nematic Phase:

(132) Samples having a nematic phase were placed in glass bottles and stored in freezers at 0 C., 10 C., 20 C., 30 C. and 40 C. for 10 days, and then the liquid crystal phases were observed. For example, when the sample remained in the nematic phase at 20 C. and changed to a crystalline or a smectic phase at 30 C., T.sub.C was recorded as <20 C.

(133) Viscosity (Bulk Viscosity; n; Measured at 20 C.; mPa.Math.s):

(134) An E-type rotational viscometer manufactured by Tokyo Keiki Inc. was used for measurement.

(135) Viscosity (Rotational Viscosity; 1; Measured at 25 C.; mPa.Math.s):

(136) The measurement was performed according to the method described in M. Imai et al., Molecular Crystals and Liquid Crystals, Vol. 259, 37 (1995). The sample was placed in a TN cell with a twist angle of 0 and a gap (cell gap) of 5 m between two glass substrates. Voltage was applied to this element in steps of 0.5 V in a range from 16 V to 19.5 V. After 0.2 seconds of non-application, an application was repeated under conditions of a single rectangular wave (rectangular pulse; 0.2 seconds) and non-application (2 seconds). A peak current and a peak time of a transient current generated by this application were measured. A value of a rotational viscosity was obtained based on these measured values and Calculation Formula (8) described on page 40 of the paper of M. Imai et al. A value of a dielectric anisotropy required for this calculation was obtained according to a method described below using the cell used for measuring this rotational viscosity.

(137) Refractive Index Anisotropy (in the Case of n<0.30; Measured at 25 C.):

(138) The measurement was performed with an Abbe refractometer having a polarizing plate attached to an eyepiece, using light at a wavelength of 589 nm. After rubbing the surface of a main prism in one direction, a sample was added dropwise onto the main prism. A refractive index n.sub.// was measured when the direction of polarization was parallel to the rubbing direction. A refractive index n.sub. was measured when the direction of polarization was perpendicular to the rubbing direction. A value of a refractive index anisotropy was calculated according to an equation: n=n.sub.//n.sub..

(139) Refractive Index Anisotropy (in the Case of n0.30; Measured at 25 C.):

(140) A sample was placed in an element composed of two glass substrates and oriented antiparallel. A thickness direction retardation (Rth) of this element was measured using a phase difference film/optical material inspection device (manufactured by Otsuka Electronics Co., Ltd., product name: RETS-100), and a refractive index anisotropy (n) was calculated based on the retardation value (Rth) and a gap (d: cell gap) between the glass substrates according to the following equation. The wavelength of light used was 589 nm.
Rth=n.Math.d
Dielectric Anisotropy (; Measured at 25 C.):

(141) A sample was placed in a TN element in which the gap (cell gap) between two glass substrates was 9 m and the twist angle was 80 degrees. A sine wave (10 V, 1 kHz) was applied to this element, and after 2 seconds, a dielectric constant (.sub.//) in a major axis direction of liquid crystal molecules was measured. A sine wave (0.5 V, 1 kHz) was applied to this element, and after 2 seconds, a dielectric constant (.sub.) in a minor axis direction of liquid crystal molecules was measured. The value of the dielectric anisotropy was calculated according to an equation: =.sub.//.sub..

(142) Voltage Holding Ratio (VHR; Measured at 25 C.; %):

(143) A cell used for measurement had the following structure. Specifically, an ITO electrode and a rubbed polyimide orientation film were disposed sequentially on each substrate. Two such substrates were bonded together with the orientation film surfaces facing inward such that an angle of rubbing directions between the upper and lower substrates was 90 degrees. The gap (cell gap) between the two glass substrates was 5 m. The liquid crystal composition was sealed in this cell. This TN cell was charged by applying a pulse voltage (5 V for 60 microseconds). A decaying voltage was measured for 16.7 milliseconds with a high-speed voltmeter, and an area A between a voltage curve and a horizontal axis in a unit period was obtained. An area B was an area in the case where there was no decay. A voltage holding ratio was expressed as a percentage of the area A to the area B.

(144) Dielectric Anisotropy at 28 GHz (Measured at 25 C.):

(145) For a dielectric anisotropy at 28 GHz (@28 GHz), a variable short-circuit waveguide to which a window material was attached was filled with liquid crystals according to a method disclosed in Applied Optics, Vol. 44, No. 7, p. 1150 (2005) and held in a static magnetic field of 0.3 T for 3 minutes. A microwave of 28 GHz was inputted to the waveguide, and an amplitude ratio of a reflected wave to an incident wave was measured. The measurement was performed by changing an orientation of the static magnetic field and a tube length of the short-circuit unit to determine refractive indices (n: ne, no) and loss parameters (: e, o).

(146) For calculation of a complex dielectric constant (, ), the calculated refractive indices, the loss parameters, and the following relational expressions were used.

(147) $=n^2-{}^2$$=2n$$=2/c$

(148) Herein, c is a light velocity in vacuum, is an angular velocity, and is an extinction coefficient. .sub.// was calculated based on ne, .sub. was calculated based on no, and the dielectric anisotropy (@28 GHz) was calculated according to: .sub.//-.sub..

(149) Dielectric Loss Tangent at 28 GHz (Tan ; Measured at Room Temperature):

(150) A dielectric loss tangent at 28 GHz (tan @28 GHz) was calculated based on / using the complex dielectric constant (, ). Since anisotropy also appeared in tan , a larger value was recorded.

(151) Compounds in Examples are represented by symbols based on the definitions in Table 2. Numbers in parentheses after the symbols correspond to numbers of the compounds. The symbol (-) means other liquid crystalline compounds. The proportion (percentage) of the liquid crystalline compounds is weight percentage (weight %) based on the weight of the liquid crystal composition. Finally, characteristic values of the composition are summarized.

(152) TABLE-US-00002 TABLE 2 Notation of compounds using symbols R(A.sub.1)Z.sub.1 . . . Z.sub.n(A.sub.n)R Symbol 1) Left terminal group R C.sub.nH.sub.2n+1 n- C.sub.nH.sub.2n+1O nO CH.sub.2CH V C.sub.nH.sub.2n+1CC nT 2) Right terminal group R C.sub.nH.sub.2n+1 -n OC.sub.nH.sub.2n+1 On CHCH.sub.2 V CCC.sub.nH.sub.2n+1 Tn CN C CCCN TC NCS NCS CCCF.sub.3 TCF3 C.sub.nH.sub.2nCHCH.sub.2 -nV 3) Bonding group Z.sub.n C.sub.2H.sub.4 2 COO E CHCH V CC T CCCC TT 4) Ring structure An B B(2F) B(F) B(F, F) 0 B(2Me) B(Me) B(2Me, 5Me) B(2Me, 5F) B(2F, 5Me) 5) Notation example Example No. 1 3-BTB(2Me)-NCS Example No. 2 3-BB(F)B(F,F)-NCS Example No. 3 3-BB(F)TB(Me)-NCS Example No. 4 3-BTB(2Me,5F)TB-NCS Example No. 5 3-HBB(F,F)-NC Example No. 6 5-BB(F)TB(2F,5Me)B-NCS 0

[Comparative Example 1] Liquid Crystal Composition C1

(153) TABLE-US-00003 3-BTB(2Me)-NCS (1-7) 15% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 10% 3-BB(F)B(F,F)-NCS (2-2) 5% 3-BB(F)B(Me)-NCS (2-6) 10% 3-BB(F)TB(Me)-NCS (3-2) 5% 5-BB(F)TB(Me)-NCS (3-2) 10% 5-BB(F)TB(2Me,5Me)-NCS (3-3) 5% 3-BB(F)TB(2Me,5F)-NCS (3-4) 10% 3-BTB(2Me,5F)TB-NCS (4-2) 10% 3-BTB(2Me,5F)B(F)-NCS (S) 10% NI = 110.4 C.; Tc < 30 C.; n = 0.470; = 15.1

(154) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition C1 at 28 GHz were as follows.

(155) @28 GHz=1.26

(156) tan @28 GHz=0.007

[Example 1] Liquid Crystal Composition M1

(157) TABLE-US-00004 3-BTB(2Me)-NCS (1-7) 15% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 10% 3-BB(F)B(F,F)-NCS (2-2) 5% 3-BB(F)B(Me)-NCS (2-6) 10% 3-BB(F)TB(Me)-NCS (3-2) 13% 5-BB(F)TB(Me)-NCS (3-2) 12% 5-BB(F)TB(2Me,5Me)-NCS (3-3) 5% 3-BB(F)TB(2Me,5F)-NCS (3-4) 10% 3-BTB(2Me,5F)TB-NCS (4-2) 10% NI = 115.2 C.; Tc < 40 C.; n = 0.475; = 14.9

(158) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M1 at 28 GHz were as follows.

(159) @28 GHz=1.28

(160) tan @28 GHz=0.006

(161) A composition composed of the compound (1) to the compound (4), excluding the compound(S), in Comparative Example 1 corresponds to Example 1. Herein, @28 GHz of the composition in Comparative Example 1 is 1.26, and @28 GHz of the composition in Example 1 is 1.28, both of which may be considered to be large. tan @28 GHz is 0.007 and 0.006, respectively, with the composition in Example 1 exhibiting a slightly smaller value. Furthermore, in Comparative Example 1, the upper limit temperature is 110.4 C. and the lower limit temperature is <30 C., and in Example 1, the upper limit temperature is 115.2 C. and the lower limit temperature is <40 C. It could be confirmed that, without applying the compound (S), a liquid crystal composition having a nematic phase in a wider temperature range can be obtained.

[Comparative Example 2] Liquid Crystal Composition C2

(162) TABLE-US-00005 3-BTB(2Me)-NCS (1-7) 20% 5-BTB(2Me)-NCS (1-7) 10% 3-BB(F)TB(Me)-NCS (3-2) 10% 5-BB(F)TB(Me)-NCS (3-2) 10% 5-BB(F)TB(2Me,5Me)-NCS (3-3) 10% 5-B(F)TB(F)-TC (T) 10% 5-BTB(F)-TC (T) 15% 3-BB(F)TB-TC (T) 10% 5-BB(F)TB-TC (T) 5% NI = 131.5 C.; Tc < 30 C.; n = 0.496; = 21.6; VHR = 73.9%.

(163) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition C2 at 28 GHz were as follows.

(164) @28 GHz=1.25

(165) tan @28 GHz=0.009

[Example 2] Liquid Crystal Composition M2

(166) TABLE-US-00006 3-BTB(2Me)-NCS (1-7) 18% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 17% 3-BB(F)B(F,F)-NCS (2-2) 15% 3-BB(F)TB(Me)-NCS (3-2) 13% 5-BB(F)TB(Me)-NCS (3-2) 7% 3-BB(F)TB(2Me,5F)-NCS (3-4) 10% 3-BTB(2Me,5F)TB-NCS (4-2) 10% NI = 100.1 C.; Tc < 40 C.; n = 0.465; = 15.1; VHR = 99.1%.

(167) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M2 at 28 GHz were as follows.

(168) @28 GHz=1.24

(169) tan @28 GHz=0.006

(170) A composition composed of the compound (1) to the compound (4), excluding the compound (T), in Comparative Example 2 corresponds to Example 2. Herein, @28 GHz of the composition in Comparative Example 2 is 1.25, and @28 GHz of the composition in Example 2 is 1.24, both of which may be considered to be large. In contrast, tan @28 GHz is 0.009 and 0.006, respectively, with the composition in Example 2 exhibiting a significantly smaller value. Furthermore, VHR is 73.9% and 99.1%, respectively, indicating that the composition in Comparative Example 2 is unsuitable for TFT driving. Based on these results, it could be confirmed that the composition consisting of the compound (1) to the compound (4) has the effect of reducing tan @28 GHz and has a very high VHR.

[Example 3] Liquid Crystal Composition M3

(171) TABLE-US-00007 3-BTB(2Me)-NCS (1-7) 20% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 16% 3-BB(F)B(F,F)-NCS (2-2) 9% 3-BB(F)TB(Me)-NCS (3-2) 13% 5-BB(F)TB(Me)-NCS (3-2) 7% 3-BB(F)TB(2Me,5F)-NCS (3-4) 15% 3-BTB(2Me,5F)TB-NCS (4-2) 10% NI = 100.0 C.; Tc < 20 C.; n = 0.468; = 14.7; VHR = 99.2%.

(172) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M3 at 28 GHz were as follows.

(173) @28 GHz=1.28

(174) tan @28 GHz=0.006

[Example 4] Liquid Crystal Composition M4

(175) TABLE-US-00008 3-BTB(2Me)-NCS (1-7) 20% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 15% 3-BB(F)B(F,F)-NCS (2-2) 17% 3-BB(F)TB(Me)-NCS (3-2) 13% 3-BB(F)TB(2Me,5F)-NCS (3-4) 15% 3-BTB(2Me,5F)TB-NCS (4-2) 10% NI = 100.1 C.; Tc < 20 C.; n = 0.467; = 15.7; VHR = 99.3%.

(176) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M4 at 28 GHz were as follows.

(177) @28 GHz=1.26

(178) tan @28 GHz=0.006

[Example 5] Liquid Crystal Composition M5

(179) TABLE-US-00009 3-BTB(2Me)-NCS (1-7) 18% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 16% 3-BB(F)B(F,F)-NCS (2-2) 15% 3-BB(F)TB(2Me)-NCS (3-1) 8% 3-BB(F)TB(Me)-NCS (3-2) 13% 3-BB(F)TB(2Me,5F)-NCS (3-4) 10% 3-BTB(2Me,5F)TB-NCS (4-2) 10% NI = 102.5 C.; Tc < 40 C.; n = 0.459; = 15.5; VHR = 99.2%.

(180) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M5 at 28 GHz were as follows.

(181) @28 GHz=1.20

(182) tan @28 GHz=0.006

[Example 6] Liquid Crystal Composition M6

(183) TABLE-US-00010 3-BTB(2Me)-NCS (1-7) 20% 5-BTB(2Me)-NCS (1-7) 15% 3-BTB(Me)-NCS (1-8) 10% 3-BB(F)B(F,F)-NCS (2-2) 10% 3-BB(F)TB(2Me)-NCS (3-1) 12% 3-BB(F)TB(Me)-NCS (3-2) 13% 3-BB(F)TB(2Me,5F)-NCS (3-4) 10% 3-BTB(2Me,5F)TB-NCS (4-2) 10% NI = 101.2 C.; Tc < 40 C.; n = 0.471; = 14.6; VHR = 99.2%.

(184) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M6 at 28 GHz were as follows.

(185) @28 GHz=1.27

(186) tan @28 GHz=0.006

[Example 7] Liquid Crystal Composition M7

(187) TABLE-US-00011 3-BTB(2Me)-NCS (1-7) 17% 4-BTB(2Me)-NCS (1-7) 8% 5-BTB(2Me)-NCS (1-7) 15% 3-BBB(2Me)-NCS (2-5) 15% 3-BB(F)TB(Me)-NCS (3-2) 5% 5-BB(F)TB(Me)-NCS (3-2) 15% 5-BB(F)TB(2Me,5Me)-NCS (3-3) 5% 3-BB(F)TB(2Me,5F)-NCS (3-4) 10% 3-BTB(2Me,5F)TB-NCS (4-2) 10% NI = 106.6 C.; Tc < 40 C.; n = 0.460; = 15.5; VHR = 99.2%.

(188) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M7 at 28 GHz were as follows.

(189) @28 GHz=1.25

(190) tan @28 GHz=0.006

[Example 8] Liquid Crystal Composition M8

(191) TABLE-US-00012 3-BTB(2Me)-NCS (1-7) 15% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 15% 3-BB(F)B(F,F)-NCS (2-2) 15% 4-BB(F)B(F,F)-NCS (2-2) 10% 3-BB(F)TB(Me)-NCS (3-2) 5% 5-BB(F)TB(Me)-NCS (3-2) 15% 5-BB(F)TB(2Me,5Me)-NCS (3-3) 5% 5-BTB(F)TB(2Me,5F)-NCS (4-1) 10% NI = 102.5 C.; Tc < 40 C.; n = 0.445; = 15.9; VHR = 99.0%.

(192) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M8 at 28 GHz were as follows.

(193) @28 GHz=1.19

(194) tan @28 GHz=0.006

[Example 9] Liquid Crystal Composition M9

(195) TABLE-US-00013 3-BTB(2Me)-NCS (1-7) 18% 4-BTB(2Me)-NCS (1-7) 9% 5-BTB(2Me)-NCS (1-7) 18% 3-BB(F)B(F,F)-NCS (2-2) 14% 3-BB(F)TB(Me)-NCS (3-2) 10% 5-BB(F)TB(Me)-NCS (3-2) 8% 3-BB(F)TB(2Me,5F)-NCS (3-4) 13% 5-BTB(2Me,5Me)TB-NCS (4-4) 10% NI = 101.4 C.; Tc < 40 C.; n = 0.464; = 15.2; VHR = 99.0%.

(196) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M9 at 28 GHz were as follows.

(197) @28 GHz=1.25

(198) tan @28 GHz=0.006

[Example 10] Liquid Crystal Composition M10

(199) TABLE-US-00014 3-BTB(2Me,5F)-NCS (1-3) 10% 3-BTB(2Me)-NCS (1-7) 18% 5-BTB(2Me)-NCS (1-7) 17% 3-BB(F)B(F,F)-NCS (2-2) 18% 3-BB(F)TB(Me)-NCS (3-2) 9% 5-BB(F)TB(Me)-NCS (3-2) 3% 3-BB(F)TB(2Me,5F)-NCS (3-4) 13% 3-BTB(2Me,5F)TB-NCS (4-2) 12% NI = 101.0 C.; Tc < 30 C.; n = 0.461; = 15.5; VHR = 99.1%.

(200) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M10 at 28 GHz were as follows.

(201) @28 GHz=1.23

(202) tan @28 GHz=0.006

[Example 11] Liquid Crystal Composition M11

(203) TABLE-US-00015 3-BTB(2Me)-NCS (1-7) 18% 4-BTB(2Me)-NCS (1-7) 9% 5-BTB(2Me)-NCS (1-7) 18% 3-BB(F)B(F,F)-NCS (2-2) 14% 3-BB(F)TB(Me)-NCS (3-2) 5% 5-BB(F)TB(Me)-NCS (3-2) 5% 3-BB(F)TB(2Me,5F)-NCS (3-4) 13% 3-BTB(2Me,5F)TB-NCS (4-2) 13% 3-HBB(F,F)-NCS (5-2) 5% NI = 102.6 C.; Tc < 20 C.; n = 0.453; = 15.6; VHR = 99.1%.

(204) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M11 at 28 GHz were as follows.

(205) @28 GHz=1.24

(206) tan @28 GHz=0.006

[Example 12] Liquid Crystal Composition M12

(207) TABLE-US-00016 3-BTB(2Me)-NCS (1-7) 15% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 15% 3-BB(F)B(F,F)-NCS (2-2) 15% 3-BB(F)TB(Me)-NCS (3-2) 5% 5-BB(F)TB(Me)-NCS (3-2) 15% 5-BB(F)TB(2Me,5Me)-NCS (3-3) 5% 3-BTB(2Me,5F)TB-NCS (4-2) 10% 3-HBB(F,F)-NCS (5-2) 10% NI = 119.7 C.; Tc < 40 C.; n = 0.448; = 17.2; VHR = 99.0%.

(208) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M12 at 28 GHz were as follows.

(209) @28 GHz=1.17

(210) tan @28 GHz=0.006

[Example 13] Liquid Crystal Composition M13

(211) TABLE-US-00017 3-BTB(2Me)-NCS (1-7) 17% 4-BTB(2Me)-NCS (1-7) 11% 5-BTB(2Me)-NCS (1-7) 17% 3-BB(F)B(F,F)-NCS (2-2) 12% 3-BB(F)TB(Me)-NCS (3-2) 10% 3-BB(F)TB(2Me,5F)-NCS (3-4) 13% 3-BTB(2Me,5F)TB-NCS (4-2) 10% 3-HBB(F,F)-NCS (5-2) 10% NI = 102.5 C.; Tc < 30 C.; n = 0.444; = 15.6; VHR = 99.2%.

(212) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M13 at 28 GHz were as follows.

(213) @28 GHz=1.18

(214) tan @28 GHz=0.006

[Example 14] Liquid Crystal Composition M14

(215) TABLE-US-00018 3-BTB(2Me)-NCS (1-7) 17% 4-BTB(2Me)-NCS (1-7) 11% 5-BTB(2Me)-NCS (1-7) 17% 3-BB(F)B(F,F)-NCS (2-2) 17% 3-BB(F)TB(Me)-NCS (3-2) 5% 3-BB(F)TB(2Me,5F)-NCS (3-4) 13% 3-BTB(2Me,5F)TB-NCS (4-2) 10% 3-HBB(F,F)-NCS (5-2) 10% NI = 101.1 C.; Tc < 30 C.; n = 0.438; = 16.0; VHR = 99.3%.

(216) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M14 at 28 GHz were as follows.

(217) @28 GHz=1.20

(218) tan @28 GHz=0.006

[Example 15] Liquid Crystal Composition M15

(219) TABLE-US-00019 3-BTB(2Me)-NCS (1-7) 20% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 14% 3-BB(F)B(F,F)-NCS (2-2) 16% 3-BB(F)TB(Me)-NCS (3-2) 13% 5-BB(F)TB(Me)-NCS (3-2) 12% 3-BTB(2Me,5F)TB-NCS (4-2) 10% 5-BB(F)TB(2Me)B(F,F)-NCS (6-6) 5% NI = 106.6 C.; Tc < 20 C.; n = 0.464; = 15.3; VHR = 99.2%.

(220) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M15 at 28 GHz were as follows.

(221) @28 GHz=1.25

(222) tan @28 GHz=0.006

[Example 16] Liquid Crystal Composition M16

(223) TABLE-US-00020 3-BTB(2Me)-NCS (1-7) 20% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 14% 3-BB(F)B(F,F)-NCS (2-2) 16% 3-BB(F)TB(Me)-NCS (3-2) 13% 5-BB(F)TB(Me)-NCS (3-2) 12% 3-BTB(2Me,5F)TB-NCS (4-2) 10% 5-BB(F)TB(2F,5Me)TB-NCS (6-8) 5% NI = 108.6 C.; Tc < 30 C.; n = 0.470; = 14.8; VHR = 99.2%.

(224) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M16 at 28 GHz were as follows.

(225) @28 GHz=1.26

(226) tan @28 GHz=0.006

[Example 17] Liquid Crystal Composition M17

(227) TABLE-US-00021 3-BTB(2Me)-NCS (1-7) 14% 5-BTB(2Me)-NCS (1-7) 13% 3-BB(F)B(F,F)-NCS (2-2) 18% 3-BB(F)TB(Me)-NCS (3-2) 15% 5-BB(F)TB(Me)-NCS (3-2) 15% 3-BB(F)TB(2Me,5F)-NCS (3-4) 15% 3-BTB(2Me,5F)TB-NCS (4-2) 10% NI = 137.3 C.; Tc < 40 C.; n = 0.496; = 17.6; VHR = 99.3%.

(228) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M17 at 28 GHz were as follows.

(229) @28 GHz=1.35

(230) tan @28 GHz=0.006

[Example 18] Liquid Crystal Composition M18

(231) TABLE-US-00022 3-BTB(2Me)-NCS (1-7) 17% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 15% 3-BB(F)B(F,F)-NCS (2-2) 18% 3-BB(F)TB(Me)-NCS (3-2) 9% 5-BB(F)TB(Me)-NCS (3-2) 5% 3-BB(F)TB(2Me,5F)-NCS (3-4) 9% 3-BTB(2Me,5F)TB-NCS (4-2) 7% 1-BB(F)B-2V (7-3) 5% 2-BB(F)B-2V (7-3) 5% NI = 102.0 C.; Tc < 30 C.; n = 0.437; = 14.0; VHR = 99.5%.

(232) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M18 at 28 GHz were as follows.

(233) @28 GHz=1.20

(234) tan @28 GHz=0.007

[Example 19] Liquid Crystal Composition M19

(235) TABLE-US-00023 3-BTB(2Me)-NCS (1-7) 18% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 18% 3-BB(F)B(F,F)-NCS (2-2) 10% 3-BB(F)TB(Me)-NCS (3-2) 5% 5-BB(F)TB(Me)-NCS (3-2) 3% 3-BB(F)TB(2Me,5F)-NCS (3-4) 10% 3-BTB(2Me,5F)TB-NCS (4-2) 10% 3-HBB(F,F)-NCS (5-2) 16% NI = 100.8 C.; Tc < 40 C.; n = 0.430; = 15.1; VHR = 99.2%.

(236) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M19 at 28 GHz were as follows.

(237) @28 GHz=1.21

(238) tan @28 GHz=0.006

[Example 20] Liquid Crystal Composition M20

(239) TABLE-US-00024 3-BTB(2Me)-NCS (1-7) 20% 4-BTB(2Me)-NCS (1-7) 10% 5-BTB(2Me)-NCS (1-7) 15% 3-BB(F)B(F,F)-NCS (2-2) 10% 3-BB(F)TB(Me)-NCS (3-2) 10% 5-BB(F)TB(Me)-NCS (3-2) 10% 3-BB(F)TB(2Me,5F)-NCS (3-4) 5% 3-BTB(2Me,5F)TB-NCS (4-2) 10% 3-BB(F)TB-4 (7-4) 10% NI = 101.9 C.; Tc < 40 C.; n = 0.446; = 12.9; VHR = 99.5%.

(240) The dielectric anisotropy (@28 GHz) and the dielectric loss tangent (tan @28 GHz) of the liquid crystal composition M20 at 28 GHz were as follows.

(241) @28 GHz=1.20

(242) tan @28 GHz=0.006

(243) The compositions of Example 1 to Example 20 each include the compound (1) to the compound (4), and do not include the compound(S). As the constituent components of the composition, those including more of the compound (1) to the compound (4) exhibit a larger dielectric anisotropy at high frequencies. In particular, the value of tan @28 GHz becomes smaller.

(244) The liquid crystal compositions containing the compound (1) to the compound (4) and not containing the compound(S) can keep @28 GHz large and reduce the value of tan @28 GHz while maintaining the basic performance as liquid crystal compositions.

(245) The characteristics required for a liquid crystal composition include: a large dielectric anisotropy () that enables large phase control in a frequency domain used for phase control; and a small dielectric loss tangent (tan ) proportional to absorption energy of electromagnetic wave signals of the liquid crystal composition. The results of Examples and Comparative Examples have illustrated that the composition of the disclosure has a large dielectric anisotropy (48@28 GHz) and a small dielectric loss tangent (tan @28 GHz). In general, the smaller the tan , the lower the absorption energy of electromagnetic waves. Accordingly, the liquid crystal composition using the compounds represented by Formula (1) is capable of reducing the absorption energy of electromagnetic wave signals and can set the loss of electromagnetic wave signals to be smaller. Based on the above, it can be concluded that the liquid crystal composition of the disclosure can perform transmission of electromagnetic wave signals more efficiently.

INDUSTRIAL APPLICABILITY

(246) The liquid crystal composition of the disclosure can satisfy the high-frequency characteristics of the composition, such as a large refractive index anisotropy in the frequency domain for performing control on electromagnetic wave signals and a small dielectric loss tangent (tan ), while having a high upper limit temperature of the nematic phase and a low lower limit temperature of the nematic phase. Furthermore, it becomes possible to provide more preferable liquid crystal compositions by further satisfying at least one of characteristics of the composition, such as a large dielectric anisotropy at low frequencies for reducing a driving voltage, a small viscosity, a large specific resistance in the driving frequency domain, and stability against heat. Elements containing this composition may be used for control on electromagnetic wave signals in the frequency range from 1 GHz to 10 THz.