Liquid crystal compounds, liquid crystal compositions, and devices

Abstract

As a material used for an element for controlling electromagnetic waves in the frequency range of 1 GHz to 10 THz, there is provided a liquid crystalline compound having at least one physical property such as stability against heat, a high clearing point, a low lower limit temperature of the liquid crystal phase, a small viscosity, a very large refractive index anisotropy, and excellent compatibility with other liquid crystalline compounds. Further, there is provided a liquid crystal composition containing this compound, and an element capable of controlling electromagnetic waves in a wide temperature range using this composition. 【Solution means】 A compound represented by formula (1). TIFF2026099717000049.tif27147For example, R 1 is an alkyl having 1 to 12 carbon atoms; L 1 is fluorine; L 2 is hydrogen; L 3 is fluorine; L 4 is methyl; Y 1 is hydrogen; Y 2 is hydrogen; n is 0.

Description

[Technical Field]

[0001] This invention relates to liquid crystalline compounds, nematic phases, and liquid crystal compositions having positive dielectric anisotropy, and devices containing the same. In particular, it relates to liquid crystal compositions and devices containing the same used for electromagnetic wave control in the frequency range of 1 GHz to 10 THz. [Background technology]

[0002] As a new application for liquid crystal compositions, which are widely used in display applications, there is growing interest in their use in high-frequency technologies such as antennas that transmit and receive electromagnetic waves.

[0003] Specifically, elements used for electromagnetic wave control in the frequency range of 1 GHz to 10 THz include millimeter-wave or microwave antenna arrays and electromagnetic wave reflectors. Various methods for these elements are being considered, but methods using liquid crystal compositions are attracting attention because they are thought to have fewer failures due to the absence of mechanically moving parts.

[0004] In communication technology, high-frequency bands have not been widely utilized until now, but due to demands for ultra-high speed, large capacity, low latency, and numerous simultaneous connections, the use of millimeter-wave bands (24GHz to 100GHz) in particular is expected to increase. Allocation of frequency bands for this use has begun globally. Approximately 20 countries have allocated millimeter-wave frequencies of 24-29.5GHz for communication, and in the United States, this has expanded to 37-40GHz and 47.2-48.2GHz, with the possibility of higher frequencies being allocated in many more countries in the future. In Japan, 27-29.5GHz has been allocated to mobile phone operators for commercial use. Thus, the use of millimeter waves, particularly around the 28GHz frequency band, is increasing in various countries.

[0005] In liquid crystal compositions exhibiting dielectric anisotropy, at frequencies lower than the relaxation frequency (approximately tens of kHz to hundreds of MHz or less), the dielectric constant differs in the direction perpendicular to the orientation direction of the liquid crystal composition. Even at frequencies higher than the relaxation frequency, i.e., in the range from microwaves to terahertz waves (approximately 10 THz), although the values ​​become smaller, a difference in dielectric constant between the direction perpendicular to the orientation direction and the direction horizontal to the orientation direction of the liquid crystal composition is observed, indicating dielectric anisotropy (Non-Patent Literature 1). Therefore, the liquid crystal composition can change its dielectric constant in one direction by changing the orientation direction of the molecules in response to an external field (electric field).

[0006] By utilizing this property, the molecular orientation of a liquid crystal composition can change in response to an external electric field, thereby altering its dielectric constant. For example, this makes it possible to realize microwave devices that can electrically control the transmission characteristics of high-frequency transmission lines from the outside. Such devices have been reported, including voltage-controlled millimeter-wave variable phase shifters in which a waveguide is filled with a nematic liquid crystal composition, and broadband microwave / millimeter-wave variable phase shifters using a nematic liquid crystal composition as a dielectric substrate for a microstrip line (Patent Documents 1 and 2).

[0007] In recent years, research into metamaterial technology, which exhibits behaviors not found in naturally occurring materials in response to electromagnetic waves, including light, has been progressing. Due to its characteristics, it is being applied to technological fields such as high-frequency devices, microwave devices, and antennas, and various electromagnetic wave control elements have been devised. As a capacitance control material for transmission lines using metamaterials, the use of liquid crystal compositions, which can change the orientation of molecules and alter the dielectric constant in response to an external electric field, is also being considered.

[0008] Elements used in such electromagnetic wave control should ideally have characteristics such as high gain and low loss. When considering phase control of high-frequency signals, the characteristics required of the liquid crystal composition are that it has a large dielectric anisotropy that enables large phase control in the frequency range used for phase control, and that the dielectric loss tangent (tanδ) of the liquid crystal composition, which is proportional to the absorption energy of the electromagnetic wave signal, is small (Non-Patent Literature 1).

[0009] Since liquid crystal compositions are dielectrics, they exhibit polarization (dielectric polarization) in response to an external field (electric field). The dielectric constant is a physical property that indicates the dielectric's response to an electric field, and the magnitude of the dielectric constant is related to dielectric polarization. The mechanisms by which dielectric polarization occurs can be broadly divided into three categories: electronic polarization, ionic polarization, and orientation polarization. Orientation polarization is polarization associated with the orientation of the dipole moment, and as mentioned above, it relaxes at frequencies ranging from several hundred kHz to several hundred MHz, resulting in a decrease in orientation polarization. Consequently, at high frequencies (ranging from microwaves to terahertz waves (approximately 10 THz)), dielectric polarization involves only electronic and ionic polarization. Note that in lossless dielectrics, the relationship between dielectric constant and refractive index is ε=n 2 There is a relationship between these factors, and if we consider the ionic polarization of the liquid crystal composition to be small, then the larger the refractive index anisotropy (Δn) in visible light due to electronic polarization, the larger the dielectric anisotropy (Δε) in the high-frequency region is considered to be (Non-Patent Literature 2). Therefore, it is preferable for the liquid crystal composition to have a large refractive index anisotropy.

[0010] Furthermore, a low drive voltage is desirable in order to achieve the switching characteristics and high energy efficiency of the element. For this reason, it is preferable for the liquid crystal composition to have high dielectric anisotropy even at low frequencies (frequencies lower than the relaxation frequency).

[0011] In addition, elements used for electromagnetic wave control are required to have a wide operating temperature range and a short response time. The characteristics of the liquid crystal composition are also required to be a high upper temperature limit for the nematic phase, a low lower temperature limit for the nematic phase, thermal stability, and low viscosity.

[0012] Conventional liquid crystal compositions used in such elements are disclosed in Patent Documents 3 and 4. [Prior art documents] [Patent Documents]

[0013] [Patent Document 1] International Publication No. 2017 / 201515 [Patent Document 2] International Publication No. 2017 / 208996 [Patent Document 3] Japanese Patent Publication No. 2004-285085 [Patent Document 4] Japanese Patent Publication No. 2011-74074 [Non-patent literature]

[0014] [Non-Patent Document 1] EKISHO, Vol. 23 (No. 1), (2019), pp. 51-55 [Non-Patent Document 2] Dielectric Phenomena, The Institute of Electrical Engineers of Japan, Ohmsha Co., Ltd., July 25, 1973, pp. 92-95. [Overview of the Initiative] [Problems that the invention aims to solve]

[0015] As a material for elements used in electromagnetic wave control, liquid crystal compositions are required to have a high upper temperature limit and a low lower temperature limit for the nematic phase, while also possessing large dielectric anisotropy (large refractive index anisotropy), small dielectric loss tangent (tanδ) in the frequency range used for electromagnetic wave control, and large dielectric anisotropy at low frequencies for reducing the driving voltage. More preferably, they are required to have low viscosity, high resistivity in the driving frequency range, and thermal stability.

[0016] However, conventional liquid crystal compositions used in display applications and the like are insufficient in terms of characteristics for use in elements used for such electromagnetic wave control. This is because they have characteristics such as high insertion loss and / or insufficient phase shift, making them unsuitable for use in high-frequency control.

[0017] The development of liquid crystal materials for devices used in electromagnetic wave control is still in its early stages, and attempts are constantly being made to develop novel compounds that enable the optimization of such devices in order to improve the characteristics of high-frequency control. Furthermore, specific liquid crystal compositions are required for use as materials for devices used in electromagnetic wave control.

[0018] The object of the present invention is to provide liquid crystalline compounds and liquid crystal compositions, as well as elements containing such compositions, that have good required characteristics as described above and excellent balance of characteristics, for use as materials for electromagnetic wave control elements with frequencies in the range of 1 GHz to 10 THz. [Means for solving the problem]

[0019] As a result of diligent research, the inventors discovered that a liquid crystal composition containing a liquid crystal compound represented by formula (1) having a specific structure solves the above problems, and thus completed the present invention.

[0020] The present invention includes the following items, among others.

[0021] Item 1. A compound represented by formula (1). TIFF2026099717000001.tif27147 In equation (1), R 1 is hydrogen, a halogen, or an alkyl group having 1 to 12 carbon atoms, wherein in the alkyl group, at least one -CH2- may be replaced with -O- or -S-, and at least one -(CH2)2- may be replaced with -CH=CH- or -C≡C-, and in these groups, at least one hydrogen may be replaced with a halogen; L 1 , L 2 , L 3 and L 4 These are hydrogen, fluorine, chlorine, methyl, or ethyl; Y 1 and Y 2 These are hydrogen, fluorine, or chlorine; n is 0 or 1. However, when n is 0, L 1 , L 2 , L 3 and L 4 none of any two of them are methyl, and the remaining two are not hydrogen, fluorine, chlorine or ethyl.

[0022] Item 2. As the compound represented by the formula (1), the compound according to Item 1, which is represented by any one of the formulas (1-1) to (1-18). TIFF2026099717000002.tif128136 TIFF2026099717000003.tif102136 TIFF2026099717000004.tif133138 TIFF2026099717000005.tif108139 In the formulas (1-1) to (1-18), R 1’ is alkyl having 1 to 12 carbon atoms, in which at least one -CH2- may be replaced by -O- or -S-, at least one -(CH2)2- may be replaced by -CH=CH- or -C≡C-, and in these groups, at least one hydrogen may be replaced by halogen; L 1’ is fluorine or methyl, and L 2’ is hydrogen, fluorine or methyl; Y 1’ is hydrogen or fluorine. However, in the formulas (1-1), (1-2), (1-5), (1-6) and (1-9), L 1’ and L 2’ are not both methyl at the same time; In the formulas (1-3), (1-4), (1-7) and (1-8), only one of L 1’ and L 2’ is not methyl.

[0023] Item 3. A liquid crystal composition containing at least one of the compounds described in Item 1 or 2.

[0024] Item 4. The liquid crystal composition according to item 3, further comprising at least one compound selected from the compounds represented by formula (2) and formula (3). TIFF2026099717000006.tif55115 In equations (2) and (3), R 2 and R 3 is hydrogen, a halogen, or a linear alkyl group having 1 to 12 carbon atoms, wherein in this alkyl group, at least one -CH2- may be replaced with -O- or -S-, and at least one -(CH2)2- may be replaced with -CH=CH- or -C≡C-, and in these groups, at least one hydrogen may be replaced with a halogen; L 21 , L 22 , L 23 , L 31 , L 32 and L 33 These are hydrogen, halogens, C1-C3 alkyl groups, C1-C3 fluorinated alkyl groups, or C3-C5 cycloalkyl groups; Y 21 , Y 31 , Y 32 , Y 33 , Y 34 , Y 35 and Y 36 It is either hydrogen or a halogen.

[0025] Item 5. The liquid crystal composition according to item 3 or 4, wherein the compound represented by formula (2) is at least one compound selected from the group of compounds represented by formulas (2-1) to (2-10). TIFF2026099717000007.tif122133 TIFF2026099717000008.tif101135 In equations (2-1) through (2-10), R 2’This is a linear alkyl group having 1 to 12 carbon atoms, in which at least one -(CH2)2- may be replaced with -CH=CH- or -C≡C-.

[0026] Item 6. A liquid crystal composition according to any one of items 3 to 5, wherein the compound represented by formula (3) is at least one compound selected from the group of compounds represented by formulas (3-1) to (3-11). TIFF2026099717000009.tif175132 TIFF2026099717000010.tif90135 In equations (3-1) through (3-11), R 3’ This is a linear alkyl group having 1 to 12 carbon atoms, in which at least one -(CH2)2- may be replaced by -CH=CH- or -C≡C-; Y 35’ These are hydrogen, fluorine, or chlorine.

[0027] Item 7. A liquid crystal composition according to any one of items 3 to 5, wherein, based on the weight of the liquid crystal composition, the proportion of the compound represented by formula (1) in claim 1 is in the range of 5% to 25% by weight, and the proportion of the compound represented by formula (2) is in the range of 10% to 55% by weight.

[0028] Claim 8 A liquid crystal composition according to any one of Claims 3, 4, and 6, wherein, based on the weight of the liquid crystal composition, the proportion of the compound represented by formula (1) in Claim 1 is in the range of 5% to 25% by weight, and the proportion of the compound represented by formula (3) is in the range of 20% to 50% by weight.

[0029] Item 9 A liquid crystal composition according to any one of items 3 to 6, wherein, based on the weight of the liquid crystal composition, the proportion of the compound represented by formula (1) in item 1 is in the range of 5% to 25% by weight, the proportion of the compound represented by formula (2) is in the range of 10% to 55% by weight, and the proportion of the compound represented by formula (3) is in the range of 20% to 50% by weight.

[0030] Item 8. A liquid crystal composition according to any one of items 3 to 7, wherein the refractive index anisotropy at 25°C at a wavelength of 589 nm is 0.40 or greater.

[0031] Item 9. A liquid crystal composition according to any one of items 3 to 8, wherein the dielectric anisotropy at 25°C at a frequency of 1 kHz is 10 or more.

[0032] Item 10. A liquid crystal composition according to any one of items 3 to 9, wherein the dielectric anisotropy at 25°C in the range of 1.0 to 3.0 in the range of at least one frequency range from 1 GHz to 10 THz.

[0033] Item 11. A liquid crystal composition according to any one of items 3 to 10, comprising an optically active compound.

[0034] Item 12. A liquid crystal composition according to any one of items 3 to 11, comprising a polymerizable compound.

[0035] Item 13. A liquid crystal composition according to any one of items 3 to 12, further comprising at least one of an antioxidant, an ultraviolet absorber, an antistatic agent, and a dichroic dye.

[0036] Item 14. A switching element comprising a liquid crystal composition as described in any one of items 3 to 13, wherein the dielectric constant can be reversibly controlled by reversibly changing the orientation direction of the liquid crystal molecules.

[0037] Item 15. An element used for electromagnetic wave control in the frequency range of 1 GHz to 10 THz, comprising the liquid crystal composition described in any one of items 3 to 13.

[0038] Item 16. A liquid crystal lens, a birefringent lens for stereoscopic image display, or an optical modulation element containing the liquid crystal composition described in any one of items 3 to 13. [Effects of the Invention]

[0039] According to the present invention, it is possible to provide a liquid crystalline compound that satisfies at least one of the physical properties of a compound, such as thermal stability, high transparency, very large refractive index anisotropy, and excellent compatibility with other liquid crystalline compounds. A composition containing the compound of the present invention can satisfy at least one of the properties of a composition, such as large dielectric anisotropy (large refractive index anisotropy), small dielectric loss tangent (tanδ), and large dielectric anisotropy at low frequencies for reducing the driving voltage, while having a high upper temperature limit for the nematic phase and a low lower temperature limit for the nematic phase. Furthermore, it can further satisfy at least one of the properties of a composition, such as a liquid crystalline composition having low viscosity, high resistivity in the driving frequency range, and thermal stability. A device using this composition can exhibit excellent properties that enable electromagnetic wave control over a wide temperature range. [Modes for carrying out the invention]

[0040] The following terms are used in this specification: The terms "liquid crystal composition" and "electromagnetic wave control element" may be abbreviated as "composition" and "element," respectively. "Electromagnetic wave control element" is a general term for electromagnetic wave control panels and electromagnetic wave control modules. "Liquid crystal compound" is a general term for compounds having a liquid crystal phase such as a nematic phase or a smectic phase, and compounds that do not have a liquid crystal phase but are mixed into a composition for the purpose of adjusting properties such as the temperature range, viscosity, and dielectric anisotropy of the liquid crystal phase. These compounds have a six-membered ring, such as 1,4-cyclohexylene and 1,4-phenylene, and their molecules (liquid crystal molecules) are rod-like. "Polymerizable compound" is a compound added to a composition for the purpose of generating a polymer. Liquid crystal compounds having alkenils are not classified as polymerizable compounds in this sense.

[0041] Liquid crystal compositions are prepared by mixing multiple liquid crystalline compounds. The proportion (content) of the liquid crystalline compounds is expressed as a weight percentage (W%) based on the weight of the liquid crystal composition. Additives such as optically active compounds, antioxidants, UV absorbers, stabilizers against UV light and heat, quenchers, dyes (dichroic dyes), defoamers, polymerizable compounds, polymerization initiators, polymerization inhibitors, antistatic agents, and magnetic compounds are added to the liquid crystal composition as needed. The proportion (amount) of additives, like the proportion of liquid crystalline compounds, is expressed as a weight percentage (W%) based on the weight of the liquid crystal composition. Parts per million (ppm) may also be used. The proportions of polymerization initiators and polymerization inhibitors are exceptionally expressed based on the weight of the polymerizable compounds.

[0042] The term "upper temperature limit of the nematic phase" is sometimes abbreviated as "upper temperature limit." The term "lower temperature limit of the nematic phase" is sometimes abbreviated as "lower temperature limit." The expression "increase dielectric anisotropy" means that for compositions with positive dielectric anisotropy, the value increases positively, and for compositions with negative dielectric anisotropy, the value increases negatively.

[0043] At least one compound selected from the group of compounds represented by formula (1) is sometimes abbreviated as "compound (1)". "compound (1)" means one compound or two or more compounds represented by formula (1). The same applies to compounds represented by other formulas. The "at least one" in relation to "may be substituted" means that there are no restrictions on the selection, not only in terms of position but also in terms of the number of compounds.

[0044] TIFF2026099717000011.tif2477 Let's explain using the compound (1z) above as an example. In formula (1z), the symbols α and β enclosed in hexagons correspond to rings α and β, respectively, representing rings such as a six-membered ring and a fused ring. When the subscript 'x' is 2, there are two rings α. The two groups represented by the two rings α may be the same or different. This rule applies to multiple rings α when the subscript 'x' is greater than 2. This rule also applies to other symbols, such as the bonding group Z. A diagonal line across one side of ring β indicates that any hydrogen on ring β may be replaced by a substituent (-Sp-P). The subscript 'y' indicates the number of substitutions. When the subscript 'y' is 0, there are no such substitutions. When the subscript 'y' is 2 or greater, there are multiple substituents (-Sp-P) on ring β. In this case as well, the rule "may be the same or different" applies. Note that this rule also applies when the symbol Ra is used for multiple compounds.

[0045] In formula (1z), for example, the expression "Ra and Rb are alkyl, alkoxy, or alkenyl" means that Ra and Rb are independently selected from the group alkyl, alkoxy, and alkenyl. Here, the group represented by Ra and the group represented by Rb may be the same or different. This rule also applies when the symbol Ra is used in multiple compounds. This rule also applies when multiple Ras are used in a single compound.

[0046] At least one compound selected from the compounds represented by formula (1z) is sometimes abbreviated as "compound (1z)". "Compound (1z)" means one compound represented by formula (1z), a mixture of two compounds, or a mixture of three or more compounds. The same applies to compounds represented by other formulas. The expression "at least one compound selected from the compounds represented by formula (1z) and formula (2z)" means at least one compound selected from the group of compounds (1z) and compounds (2z).

[0047] The expression "at least one 'A'" means that the number of 'A's is arbitrary. The expression "at least one 'A' may be replaced by a 'B'" means that when there is one 'A', its position is arbitrary, and when there are two or more 'A's, their positions can be chosen without restriction. The expression "at least one -CH2- may be replaced by -O-" is sometimes used. In this case, -CH2-CH2-CH2- may be converted to -O-CH2-O- by replacing a non-adjacent -CH2- with -O-. However, adjacent -CH2- will not be replaced by -O-, because this replacement would produce -OO-CH2- (peroxide).

[0048] When the alkyl group of a liquid crystalline compound is simply described as "alkyl," it refers to a linear or branched alkyl group, and does not include cycloalkyl groups unless otherwise specified. For example, alkyl groups with 1 to 12 carbon atoms refer to linear or branched alkyl groups with 1 to 12 carbon atoms. Linear alkyl groups are preferred over branched alkyl groups. These also apply to terminal groups such as alkoxy and alkenyl groups. The stereochemistry of 1,4-cyclohexylene is preferred trans over cis to increase the upper temperature limit. 2-Fluoro-1,4-phenylene refers to the following two divalent groups. In the chemical formula, fluorine may be left-facing (L) or right-facing (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. The preferred tetrahydropyran-2,5-diyl is right-facing (R) to increase the upper temperature limit. TIFF2026099717000012.tif26112

[0049] Similarly, bonding groups such as carbonyloxy can be either -COO- or -OCO-.

[0050] In the chemical formula of the component compound, the terminal group R 1 The symbol was used for several compounds. In these compounds, any two R 1 The groups represented by may be the same or different. For example, the R of compound (1-1) 1’ It is methyl, and the R of compound (1-2) 1’ In some cases, it is ethyl. R of compound (1-1) 1’ is ethyl, and R of compound (1-2) 1’ In some cases, it is propyl. This rule is R 2 , R 3 , R 4 , R 5 , R 6 , R 71 , R 72 This also applies to symbols such as these.

[0051] The present invention also includes the following: (a) the above composition further comprising at least one selected from additives such as optically active compounds, antioxidants, ultraviolet absorbers, stabilizers against ultraviolet light and heat, quenchers, dyes (dichroic dyes), defoamers, polymerizable compounds, polymerization initiators, polymerization inhibitors, antistatic agents, and magnetic compounds; (b) an element containing the above composition; (c) an element containing the above composition and used for controlling electromagnetic wave signals of any frequency from 1 GHz to 10 THz; (d) the above composition further comprising a polymerizable compound, and an element containing this composition; (e) use of the above composition as a composition having a nematic phase; (f) use of the above composition as an optically active composition by adding an optically active compound to the above composition.

[0052] The liquid crystal composition of the present invention has high dielectric anisotropy and low dielectric loss tangent (tanδ) in the frequency range of electromagnetic wave signals from 1 GHz to 10 THz. Therefore, it can be suitably used not only in the range of 1 GHz to 10 THz but also in elements related to electromagnetic waves (microwaves) in the range of 1 GHz to 50 GHz.

[0053] 1. Compound (1) Compound (1) of the present invention will be described in the following order. 1-1 describes a preferred form of compound (1). 1-2 shows a preferred embodiment of compound (1). 1-3 describes the synthesis method of compound (1).

[0054] 1-1. Form of compound (1) Compound (1) of the present invention will now be described. Preferred examples of terminal groups, bonding groups, etc., in compound (1), and the effects of these groups on the physical properties, also apply to the subformula of compound (1). TIFF2026099717000013.tif25135

[0055] In equation (1), R 1 is hydrogen, a halogen, or an alkyl group having 1 to 12 carbon atoms, wherein at least one -CH2- may be replaced with -O- or -S-, and at least one -(CH2)2- may be replaced with -CH=CH- or -C≡C-, and in these groups, at least one hydrogen may be replaced with a halogen.

[0056] The preferred stereochemistry of the -CH=CH- group in alkenyls depends on the position of the double bond. Trans configuration is preferred for alkenyls with double bonds at odd positions, such as -CH=CHCH3, -CH=CHC2H5, -CH=CHC3H7, -CH=CHC4H9, -C2H4CH=CHCH3, or -C2H4CH=CHC2H5. Cis configuration is preferred for alkenyls with double bonds at even positions, such as -CH2CH=CHCH3, -CH2CH=CHC2H5, or -CH2CH=CHC3H7. Alkenyl compounds with preferred stereochemistry have a high transparency point or a wide temperature range of the liquid crystal phase. A detailed explanation can be found in Mol. Cryst. Liq. Cryst., 1985, 131, 109 and Mol. Cryst. Liq. Cryst., 1985, 131, 327.

[0057] R 1Preferred examples include alkyl, alkoxy, alkoxyalkyl, alkenyl, alkynyl, and alkenyloxy. 1 Further preferred examples include alkyl, alkoxy, alkenyl, and alkynyl compounds.

[0058] Examples of alkyl groups include -CH3, -C2H5, -C3H7, -C4H9, and -C5H 11 , -C6H 13 -C7H 15 -C8H 17 -C9H 19 , -C 10 H 21 , -C 11 H 23 , and -C 12 H 25 That is the case.

[0059] Examples of alkoxys include -OCH3, -OC2H5, -OC3H7, -OC4H9, and -OC5H. 11 -OC6H 13 -OC7H 15 -OC8H 17 -OC9H 19 ,-OC 10 H 21 , and -OC 11 H 23 That is the case.

[0060] Examples of alkoxyalkyls include -CH2OCH3, -CH2OC2H5, -CH2OC3H7, -(CH2)2-OCH3, -(CH2)2-OC2H5, -(CH2)2-OC3H7, -(CH2)3-OCH3, -(CH2)4-OCH3, and -(CH2)5-OCH3.

[0061] Examples of alkenyls are -CH=CH2, -CH=CHCH3, -CH2CH=CH2, -CH=CHC2H5, -CH2CH=CHCH3, -(CH2)2-CH=CH2, -CH=CHC3H7, -CH2CH=CHC2H5, -(CH2)2-CH=CHCH3, and -(CH2)3-CH=CH2.

[0062] Examples of alkynyls are -C≡CH, -C≡CCH3, -C≡CC2H5, -C≡CC3H7, -C≡CC4H9, -C≡CC5H 11 , and -C≡CC6H 13 That is the case.

[0063] Examples of alkenyloxys are -OCH2CH=CH2, -OCH2CH=CHCH3, and -OCH2CH=CHC2H5.

[0064] Examples of alkyl groups in which at least one hydrogen atom is replaced by a halogen include -CH2F, -CHF2, -CF3, -(CH2)2-F, -CF2CH3, -CF2CH2F, -CF2CHF2, -CH2CF3, -CF2CF3, -(CH2)3-F, -CF2CH2CH3, -CH2CHFCH3, -CH2CF2CH3, -(CF2)3-F, -CF2CHFCF3, -CHFCF2CF3, -(CH2)4-F, -CF2(CH2)2CH3, -(CF2)4-F, -(CH2)5-F, - (CF2)5-F, -CH2Cl, -CHCl2, -CCl3, -(CH2)2-Cl, -CCl2CH3, -CCl2CH2Cl, -CCl2CHCl2, -CH2CCl3, -CCl2CCl3, -(CH2)3-Cl, -CCl2CH2C H3, -(CCl2)3-Cl, -CCl2CHClCCl3, -CHClCCl2CCl3, -(CH2)4-Cl, -(CCl2)4-Cl, -CCl2(CH2)2CH3, -(CH2)5-Cl, and -(CCl2)5-Cl.

[0065] Examples of alkoxys in which at least one hydrogen atom is replaced by a halogen include -OCH2F, -OCHF2, -OCF3, -O-(CH2)2-F, -OCF2CH2F, -OCF2CHF2, -OCH2CF3, -O-(CH2)3-F, -O-(CF2)3-F, -OCF2CHFCF3, -OCHFCF2CF3, -O(CH2)4-F, -O-(CF2)4-F, -O-(CH2)5-F, -O-(CF2)5-F, -OCH2C HFCH2CH3, -OCH2Cl, -OCHCl2, -OCCl3, -O-(CH2)2-Cl, -OCCl2CH2Cl, -OCCl2CHCl2, -OCH2CCl3, -O-(CH2)3-Cl, -O-(C Cl2)3-Cl, -OCCl2CHClCCl3, -OCHClCCl2CCl3, -O(CH2)4-Cl, -O-(CCl2)4-Cl, -O-(CH2)5-Cl, and -O-(CCl2)5-Cl.

[0066] Examples of alkenyls in which at least one hydrogen atom is replaced by a halogen include -CH=CHF, -CH=CF2, -CF=CHF, -CH=CHCH2F, -CH=CHCF3, -(CH2)2-CH=CF2, -CH2CH=CHCF3, -CH=CHCF2CF3, -CH=CHCl, -CH=CCl2, -CCl=CHCl, -CH=CHCH2Cl, -CH=CHCCl3, -(CH2)2-CH=CCl2, -CH2CH=CHCCl3, and -CH=CHCCl2CCl3.

[0067] In equation (1), L 1 , L 2 , L 3 and L 4 These are hydrogen, fluorine, chlorine, methyl, or ethyl. 1 Preferred examples are fluorine or methyl, and L 2 Preferred examples are hydrogen, fluorine, or methyl, L 3 Preferred examples are hydrogen, fluorine, methyl or ethyl, L 4 Preferred examples are hydrogen or methyl.

[0068] In equation (1), Y 1 and Y2 is hydrogen, fluorine or ethyl. Y 1 Preferred examples of are hydrogen or fluorine, Y 2 Preferred examples of are hydrogen or fluorine.

[0069] In formula (1), L 1 , L 2 , L 3 , L 4 , Y 1 and Y 2 Among them, in order to lower the lower limit temperature, it is preferable that at least two are not hydrogen. Also, L 1 , L 2 , L 3 , L 4 , Y 1 and Y 2 Among them, it is preferable that at least one is fluorine.

[0070] In formula (1), n is 0 or 1. However, when n is 0, L 1 , L 2 , L 3 and L 4 None of any two of them are methyl, and the remaining two are not hydrogen, fluorine, chlorine or ethyl. That is, when n is 0, L 1 , L 2 , L 3 and L 4 None of any two of them are methyl. Specifically, L 1 and L 3 , L 1 and L 4 , or L 3 and L 4 are not simultaneously methyl. Also, when n is 0 and L 4 is methyl, L 1 , L 2 , L 3 , Y 1 and Y 2 are not simultaneously hydrogen.

[0071] As described above, by appropriately selecting the types of terminal groups, bonding groups, etc., compounds with the desired physical properties can be obtained. Since there is no significant difference in the physical properties of the compounds, compound (1) is 2 H (deuterium), 13 It may contain isotopes such as 13C in amounts greater than their natural abundance.

[0072] 1-2. Preferred form of compound (1) Preferred embodiments of compound (1) are compounds (1-1) to (1-18). TIFF2026099717000014.tif128136 TIFF2026099717000015.tif102136 TIFF2026099717000016.tif133138 TIFF2026099717000017.tif108139 In equations (1-1) through (1-18), R 1’ These are alkyl groups having 1 to 12 carbon atoms, in which at least one -CH2- may be replaced with -O- or -S-, and at least one -(CH2)2- may be replaced with -CH=CH- or -C≡C-, and in these groups, at least one hydrogen may be replaced with a halogen; L 1’ is fluorine or methyl, L 2’ is hydrogen, fluorine, or methyl; Y 1’ It is either hydrogen or fluorine.

[0073] 1-3. Synthesis method of compound (1) The synthesis method for compound (1) is described below. Compound (1) can be synthesized by appropriately combining methods of organic synthesis. Methods for introducing the desired terminal groups, rings, and bonding groups into the starting materials are described in textbooks such as *Organic Syntheses* (John Wiley & Sons, Inc.), *Organic Reactions* (John Wiley & Sons, Inc.), *Comprehensive Organic Synthesis* (Pergamon Press), and *New Experimental Chemistry Course* (Maruzen). An example of the synthesis of compound (1) is described in the Examples section.

[0074] 2. Composition The composition of the present invention will be described in the following order. First, the composition of the component compounds in the composition will be described. Second, the main properties of the component compounds and the main effects they have on the composition will be described. Third, the combination of components in the composition, the preferred proportions of the components, and the rationale for them will be described. Fourth, the preferred forms of the added component compounds will be described. Fifth, the preferred forms of the added component compounds will be shown. Sixth, additives that may be added to the composition will be described. Finally, the uses of the composition will be described.

[0075] First, the composition of the component compounds in the composition will be described. The compositions of the present invention are classified into composition A and composition B. Composition A may further contain other liquid crystalline compounds, additives, etc., in addition to the liquid crystalline compound selected from compound (1), compound (2), and compound (3). "Other liquid crystalline compounds" are liquid crystalline compounds different from compound (1), compound (2), and compound (3). Such compounds are mixed into the composition for the purpose of further adjusting the properties. In order to prepare a liquid crystal composition having a desired refractive index anisotropy or dielectric constant anisotropy at high frequencies, it is preferable not to use liquid crystalline compounds with low refractive index anisotropy, such as monocyclic compounds or bicyclic compounds that do not contain a bonding group, as "other liquid crystalline compounds". Additives include optically active compounds, antioxidants, ultraviolet absorbers, stabilizers against ultraviolet light and heat, quenchers, dyes (dichroic dyes), defoamers, polymerizable compounds, polymerization initiators, polymerization inhibitors, antistatic agents, polar compounds, etc.

[0076] Composition B consists substantially of only liquid crystalline compounds selected from compound (1), compound (2), and compound (3). "Substantially" means that the composition may contain additives, but does not contain other liquid crystalline compounds. Composition B has fewer components than composition A. From the viewpoint of reducing costs, composition B is preferred over composition A. From the viewpoint that properties can be further adjusted by mixing in other liquid crystalline compounds, composition A is preferred over composition B.

[0077] Secondly, the main properties of the component compounds and their main effects on the properties of the composition are described. The main properties of the component compounds are summarized in Table 1 based on the effects of the present invention. In 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.

[0078] Table 1. Properties of the compound TIFF2026099717000018.tif36146

[0079] When component compounds are mixed into a composition, the main effects of the component compounds on the properties of the composition are as follows: Compound (1) primarily increases the refractive index anisotropy and dielectric anisotropy of the liquid crystal composition, thereby raising the upper temperature limit. The upper and lower temperature limits can be controlled to some extent by controlling the number of substituents on the benzene ring of compound (1). Specifically, reducing the number of substituents tends to increase the upper and lower temperature limits, while increasing the number of substituents tends to decrease them. Compound (2) primarily increases the refractive index anisotropy, dielectric anisotropy, and viscosity of the liquid crystal composition. Similar to compound (1), the number of substituents is preferably 1 or 2 from the viewpoint of lowering the lower limit temperature of the liquid crystal composition. From the viewpoint of lowering viscosity, the number of substituents is preferably 1. Compound (3) primarily increases the refractive index anisotropy, dielectric anisotropy, and upper temperature limit of the liquid crystal composition. The relationship between the number of substituents on the benzene ring and the upper and lower temperature limits is similar to that of compound (1), and from the viewpoint of lowering the lower temperature limit of the liquid crystal composition, the number of substituents is preferably 2 or 3.

[0080] Thirdly, the combination of components in the composition, the preferred proportions of the component compounds, and the rationale for them will be explained. The preferred combination of components in the composition is compound (1) + compound (2) + compound (3), from the viewpoint of expanding the temperature range of the nematic phase, increasing refractive index anisotropy and dielectric constant anisotropy, and lowering viscosity.

[0081] Based on the weight of the liquid crystal composition, the preferred proportion of compound (1) is in the range of about 5% to about 25% by weight in order to increase refractive index anisotropy and expand the temperature range of the nematic phase while increasing Δε in the high-frequency region. A more preferred proportion is in the range of about 5% to about 20% by weight. A particularly preferred proportion is in the range of about 5% to about 15% by weight.

[0082] Based on the weight of the liquid crystal composition, the preferred proportion of compound (2) is in the range of about 10% to about 55% by weight to increase refractive index anisotropy, increase Δε in the high-frequency region, broaden the temperature range of the nematic phase, and lower viscosity. A more preferred proportion is in the range of about 20% to about 50% by weight. A particularly preferred proportion is in the range of about 20% to about 45% by weight.

[0083] Based on the weight of the liquid crystal composition, the preferred proportion of compound (3) is in the range of about 20% to about 50% by weight in order to increase refractive index anisotropy and expand the temperature range of the nematic phase while increasing Δε in the high-frequency region. A more preferred proportion is in the range of about 25% to about 40% by weight. A particularly preferred proportion is in the range of about 25% to about 35% by weight.

[0084] Fourth, preferred forms of the added component compounds will be described. In compound (2) and compound (3), R 2 and R 3 is hydrogen, a halogen, or a linear alkyl group having 1 to 12 carbon atoms, wherein at least one -CH2- may be replaced with -O- or -S-, and at least one -(CH2)2- may be replaced with -CH=CH- or -C≡C-, and in these groups, at least one hydrogen may be replaced with a halogen.

[0085] In compound (2) and compound (3), preferred R 2 or R 3 To increase stability against ultraviolet light or heat, methyl, ethyl, propyl, butyl, pentyl, hexyl, methoxy, or ethoxy compounds are preferred. To reduce viscosity, methyl, ethyl, propyl, butyl, pentyl, methoxy, or ethoxy compounds are preferred.

[0086] In compounds (2-1) to (2-11) and compounds (3-1) to (3-12), R 2’ and R 3’This is a linear alkyl group having 1 to 12 carbon atoms, in which at least one -(CH2)2- may be replaced with -CH=CH- or -C≡C-.

[0087] In compound (2) and compound (3), L 21 , L 22 , L 23 , L 31 , L 32 , and L 33 The C1-C3 alkyl group is hydrogen, halogen, C1-C3 fluorinated alkyl group, or C3-C5 cycloalkyl group. Preferred L 21 , L 22 , L 23 , L 31 , L 32 and L 33 Hydrogen is used to raise the upper temperature limit, fluorine or chlorine to increase dielectric anisotropy, and fluorine, chlorine, methyl or ethyl is used to lower the lower temperature limit.

[0088] In compound (2) and compound (3), Y 21 , Y 31 , Y 32 , Y 33 , Y 34 , Y 35 and Y 36 is hydrogen or halogen. Preferred Y 21 , Y 31 , Y 32 , Y 33 , Y 34 , Y 35 and Y 36 Hydrogen is used to increase refractive index anisotropy, and fluorine or chlorine is used to increase dielectric anisotropy and to lower the lower limit temperature.

[0089] In compounds (3-1) to (3-12), Y 35’ These are hydrogen, fluorine, or chlorine.

[0090] In compound (2), L 21 , L 22 and L 23Of these, at least one is preferably methyl in order to lower the lower limit temperature. In compound (3), L 31 , L 32 and L 33 Of these, at least one is preferably methyl in order to lower the lower limit temperature.

[0091] In compound (1), compound (2), and compound (3), in order to increase the dielectric anisotropy of the entire liquid crystal composition, L 2 and Y 1 , L 4 and Y 2 , L 21 and L 22 , L 23 and Y 21 , Y 33 and Y 35 , L 31 and L 32 or L 33 and Y 36 Preferably, both are not halogens. Fifth, preferred embodiments of the added component compounds are shown. Preferred compounds (2) are compounds (2-1) through (2-10).

[0092] TIFF2026099717000019.tif122133 TIFF2026099717000020.tif101135

[0093] In equations (2-1) through (2-10), R 2’ This is a linear alkyl group having 1 to 12 carbon atoms, in which at least one -(CH2)2- may be replaced with -CH=CH- or -C≡C-.

[0094] It is more preferable that at least one of compound (2) is compound (2-2), compound (2-5), or compound (2-6).

[0095] The preferred compounds (3) are compounds (3-1) through (3-11).

[0096] TIFF2026099717000021.tif175132 TIFF2026099717000022.tif89135

[0097] In equations (3-1) through (3-11), R 3’ This is a linear alkyl group having 1 to 12 carbon atoms, in which at least one -(CH2)2- may be replaced by -CH=CH- or -C≡C-;Y 35’ These are hydrogen, fluorine, or chlorine.

[0098] It is more preferable that at least one of compound (3) is compound (3-3), compound (3-5), compound (3-8), compound (3-9), or compound (3-10).

[0099] Sixth, additives that may be added to the composition will be described. Such additives include optically active compounds, antioxidants, ultraviolet absorbers, stabilizers against ultraviolet light and heat, quenchers, dyes (dichroic dyes), defoamers, polymerizable compounds, polymerization initiators, polymerization inhibitors, antistatic agents, polar compounds, and the like. In the following, unless otherwise specified, the mixing ratios of these additives are based on the weight of the liquid crystal composition (by weight).

[0100] The combination of additives used is arbitrary; for example, different types of antioxidants can be used in combination. It is also possible to combine different types of additives, such as using antioxidants, UV absorbers, and stabilizers together.

[0101] Optically active compounds are added to the composition to induce a helical structure in the liquid crystal and to provide a twist angle. Examples of such compounds are compounds (8-1) to (8-5). A preferred proportion of the optically active compound is about 5% by weight or less. A more preferred proportion is in the range of about 0.01% by weight to about 2% by weight.

[0102] TIFF2026099717000023.tif148105

[0103] Antioxidants are added to the composition to prevent a decrease in resistivity due to heating in the atmosphere, or to maintain a high voltage retention rate not only at room temperature but also at temperatures close to the upper limit temperature after the element has been used for a long time. Preferred examples of antioxidants are compounds (9) where t is an integer from 1 to 9. TIFF2026099717000024.tif2399

[0104] In compound (9), preferred values ​​of t are 1, 3, 5, 7, or 9. A more preferred value of t is 7. Compound (9) with t = 7 has low volatility and is therefore effective in maintaining a high voltage retention rate not only at room temperature but also at temperatures close to the upper limit temperature after the device has been used for a long time. The preferred proportion of the antioxidant is about 50 ppm or more to obtain its effect, and about 600 ppm or less so as not to lower the upper limit temperature or raise the lower limit temperature. A more preferred proportion is in the range of about 100 ppm to about 300 ppm.

[0105] Preferred examples of UV absorbers include benzophenone derivatives, benzoate derivatives, and triazole derivatives. Light stabilizers such as sterically hindered amines are also preferred. Preferred examples of light stabilizers include compounds (10-1) to (10-16). The preferred proportion of these absorbers and stabilizers is about 50 ppm or more to obtain their effect, and about 10,000 ppm or less so as not to lower the upper temperature limit or raise the lower temperature limit. A more preferred proportion is in the range of about 100 ppm to about 10,000 ppm.

[0106] TIFF2026099717000025.tif237111 TIFF2026099717000026.tif239120

[0107] Preferred additives as stabilizers against ultraviolet light and heat include amino-tran compounds, such as those shown in compound (11) (U.S. Patent No. 6,495,066). TIFF2026099717000027.tif24123

[0108] In equation (11), R m and R n These are alkyl groups having 1 to 12 carbon atoms, alkoxy groups having 1 to 12 carbon atoms, alkenyl groups having 2 to 12 carbon atoms, or alkenyloxy groups having 2 to 12 carbon atoms; X a is -NO2, -C≡N, -N=C=S, fluorine, or -OCF3; Y a and Y b These are hydrogen or fluorine. The preferred proportion of these stabilizers to obtain the effect is in the range of 1 to 20% by weight, and more preferably in the range of 5% to 10% by weight.

[0109] A quencher is a compound that prevents the decomposition of a liquid crystalline compound by receiving the light energy absorbed by the compound and converting it into thermal energy. The preferred ratio of these quenchers is approximately 50 ppm or more to obtain the desired effect, and approximately 20,000 ppm or less to lower the lower limit temperature. A more preferred ratio is in the range of approximately 100 ppm to approximately 10,000 ppm.

[0110] To adapt to the GH (guest host) mode element, dichroic dyes such as azo dyes and anthraquinone dyes are added to the composition. The preferred proportion of the dye is in the range of about 0.01% to about 10% by weight. To prevent foaming, defoaming agents such as dimethyl silicone oil and methylphenyl silicone oil are added to the composition. The preferred proportion of the defoaming agent is about 1 ppm or more to obtain its effect, and about 1000 ppm or less to prevent display defects. A more preferred proportion is in the range of about 1 ppm to about 500 ppm.

[0111] Polymerizable compounds are added to the composition to make it compatible with polymer-stabilized elements. Preferred examples of polymerizable compounds are compounds having polymerizable groups such as acrylates, methacrylates, vinyl compounds, vinyloxy compounds, propenyl ethers, epoxy compounds (oxiranes, oxetanes), and vinyl ketones. More preferred examples are derivatives of acrylates or methacrylates. The preferred proportion of the polymerizable compound is about 0.05% by weight or more to obtain its effect, and about 20% by weight or less to prevent an increase in the operating temperature. A more preferred proportion is in the range of about 0.1% by weight to about 10% by weight. The polymerizable compound is polymerized by ultraviolet irradiation. Polymerization may also be carried out in the presence of a polymerization initiator such as a photopolymerization initiator. Appropriate conditions for polymerization, appropriate types of initiators, and appropriate amounts are known to those skilled in the art and are described in the literature. For example, the photopolymerization initiators Irgacure 651 (registered trademark; BASF), Irgacure 184 (registered trademark; BASF), or Darocur 1173 (registered trademark; BASF) are suitable for radical polymerization. The preferred proportion of the photopolymerization initiator is in the range of about 0.1 parts by weight to about 5 parts by weight, based on 100 parts by weight of the polymerizable compound. A more preferred proportion is in the range of about 1 part by weight to about 3 parts by weight.

[0112] When storing polymerizable compounds, polymerization inhibitors may be added to prevent polymerization. Polymerizable compounds are usually added to compositions without removing the polymerization inhibitor. Examples of polymerization inhibitors include hydroquinone, hydroquinone derivatives such as methylhydroquinone, 4-tert-butylcatechol, 4-methoxyphenol, and phenothiazine.

[0113] In this specification, polar compounds are organic compounds that possess polarity and do not include compounds with ionic bonds. Atoms such as oxygen, sulfur, and nitrogen tend to be more electronegative and have a partial negative charge. Carbon and hydrogen tend to be neutral or have a partial positive charge. Polarity arises from the fact that partial charges are not evenly distributed among different types of atoms in a compound. For example, polar compounds have at least one of the following substructures: -OH, -COOH, -SH, -NH2, >NH, >N-.

[0114] Finally, the uses of the composition will be described. Since the composition of the present invention has a lower temperature limit of about -10°C or lower and an upper temperature limit of about 70°C or higher, it can be used not only as a composition having a nematic phase, but also as an optically active composition by adding an optically active compound.

[0115] Oriented liquid crystal compositions have different dielectric constants in their vertical and horizontal directions. Therefore, they exhibit dielectric anisotropy as a characteristic.

[0116] Not limited to antenna elements, elements using liquid crystal compositions are generally composed of two substrates with a liquid crystal composition sandwiched between them, and the alignment film at the interface causes the liquid crystal molecules to be aligned in one direction (oriented). In the absence of an external field, the liquid crystal molecules within the element are aligned in one direction due to the orientation-regulating force of the alignment film, but when an external field is applied, the liquid crystal molecules within the element deviate from the alignment of the alignment film and orient themselves in the direction of the external field. When the external field is removed again, the orientation-regulating force of the alignment film causes the liquid crystal molecules to return to their original unidirectional alignment. In this way, the orientation of the liquid crystal molecules within the element can be controlled by the direction and magnitude of the external field, thereby controlling the tilt (angle) of the liquid crystal molecules within the element with respect to one direction. Because liquid crystal compositions have dielectric anisotropy, the dielectric constant of the liquid crystal composition layer within the element with respect to one direction can be controlled by controlling the angle of the liquid crystal molecules within the element with respect to one direction. For example, in the absence of an external field, the dielectric constant of the liquid crystal composition layer within the element in one direction is the dielectric constant in the direction perpendicular to the liquid crystal composition. By applying an external field perpendicular to that direction, it is possible to change it to the dielectric constant in the direction horizontal to the liquid crystal composition.

[0117] Thus, the liquid crystal composition of the present invention can be used as a switching element in which the dielectric constant can be reversibly controlled by reversibly changing the orientation direction of the liquid crystal molecules.

[0118] The angle of liquid crystal molecules within the element can be controlled using an electric field as the external field. The voltage required to drive the liquid crystal molecules is the drive voltage. To control the angle of the liquid crystal molecules, the dielectric anisotropy of the liquid crystal composition at 25°C in the frequency range of less than 1 MHz must be greater than 2. To further reduce the drive voltage, the dielectric anisotropy at 25°C in the frequency range of less than 1 MHz must be increased, preferably to 5 or more, and more preferably to 10 or more.

[0119] As previously described, the greater the refractive index anisotropy (Δn) in the visible light region (e.g., wavelength 589 nm), the greater the dielectric anisotropy (Δε) in the high-frequency region (ranging from microwaves to terahertz waves (approximately 10 THz)). The liquid crystal composition containing the compound represented by formula (1) of the present invention preferably has a refractive index anisotropy (Δn) of 0.30 or more at 25°C. In particular, when used for high-frequency applications, a Δn of 0.40 or more is more preferable, and a Δn of 0.45 or more is especially preferable.

[0120] To perform phase difference control in the high-frequency range, it is preferable that the dielectric anisotropy in the high-frequency range is 0.5 or higher. To perform phase control more effectively, it is necessary to increase the dielectric anisotropy in the high-frequency range. To achieve sufficient phase control, the dielectric anisotropy is preferably 1.0 or higher, and more preferably 1.2 or higher.

[0121] Furthermore, the composition of the present invention can be used in elements used for electromagnetic wave control in the frequency range of 1 GHz to 10 THz. Examples of applications include antenna arrays and electromagnetic wave reflectors, as well as millimeter-wave variable phase shifters and millimeter-wave radar. Various applications and methods have been developed for elements utilizing the composition of the present invention. As for antenna arrays, antenna arrays applying metamaterial technology have been developed, and as for electromagnetic wave reflectors, intelligent reflecting surfaces (IRS), reconfigurable intelligent surface (RIS) reflectors, and frequency-selective surfaces have been developed.

[0122] Elements containing this composition can 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. Because the liquid crystal composition according to the present invention exhibits high refractive index anisotropy (Δn), the amount of change in refractive index and phase modulation caused by changing the orientation direction of the liquid crystal molecules in visible light and infrared light is large and can be controlled.

[0123] Applications of these characteristic controls include, for example, birefringent lenses used for stereoscopic imaging, such as 2D / 3D switching lenses, and liquid crystal lenses used for camera focus adjustment. They can also be used in optical modulation elements (SLMs: Spatial Light Modulators) used in electronic holographic displays, and in LiDAR (Light Detection and Ranging) elements, which are distance measuring sensors. [Examples]

[0124] The present invention will be described in more detail by examples. The present invention is not limited by these examples. The present invention also includes mixtures obtained by mixing at least two of the compositions of the examples. The synthesized compounds were identified by NMR analysis. The properties of the compositions were measured by the methods described below.

[0125] NMR analysis: The measurement device used was the DRX-500 (manufactured by Bruker BioSpin, Inc.). 1 For 1H-NMR measurements, the sample was dissolved in a deuterated solvent such as CDCl3, and the measurements were performed at room temperature at 500 MHz with 16 integration cycles. Tetramethylsilane was used as an internal standard. 19 In the F-NMR measurements, CFCl3 was used as the internal standard, and the measurement was performed with 24 integration cycles. In the description of nuclear magnetic resonance spectra, s represents a singlet, d a doublet, t a triplet, q a quartet, quin a quintet, sex a sextet, m a multiplet, and br a broad spectrum.

[0126] Measurement samples: When measuring the phase structure and transition temperature, the liquid crystalline compound itself was used as the sample. When measuring physical properties such as the upper temperature limit, viscosity, optical anisotropy, and dielectric anisotropy of the nematic phase, a composition prepared by mixing the compound with a mother liquid crystal was used as the sample.

[0127] When using a sample in which the compound was mixed with a mother liquid crystal, the following measurement method was performed. A sample was prepared by mixing 20% ​​by weight of the compound with 80% by weight of the mother liquid crystal. From the measured values ​​of this sample, the extrapolated value was calculated according to the extrapolation method expressed by the following formula, and this value was recorded. <Extrapolated value> = (100 × <Measured value of sample> - <Weight % of mother liquid crystal> × <Measured value of mother liquid crystal>) / <Weight % of compound>

[0128] If crystals (or smectic phase) precipitate at 25°C even with this ratio of compound to matrix liquid crystal, the ratio of compound to matrix liquid crystal was changed in the following order: 10% by weight:90% by weight, 5% by weight:95% by weight, and 1% by weight:99% by weight. The physical properties of the sample were measured at the ratio in which crystals (or smectic phase) no longer precipitated at 25°C. Unless otherwise specified, the ratio of compound to matrix liquid crystal is 20% by weight:80% by weight.

[0129] The following mother liquid crystal (i) was used as the mother liquid crystal. The proportion of the components of mother liquid crystal (i) is expressed in weight percent. show.

[0130] TIFF2026099717000028.tif67166

[0131] Measurement Method: The characteristics were measured using the following methods. Many of these methods were those described in the JEITA standard (JEITA-ED-2521B), which is deliberated and established by the Japan Electronics and Information Technology Industries Association (JEITA), or modified versions thereof. Thin-film transistors (TFTs) were not attached to the TN elements used for measurement.

[0132] Upper limit temperature of the nematic phase (NI; °C): The sample was placed on a hot plate of a melting point analyzer equipped with a polarizing microscope and heated at a rate of 1°C / min. The temperature at which a portion of the sample changed from the nematic phase to an isotropic liquid was measured.

[0133] Lower limit temperature of the nematic phase (T C ;℃): Samples containing the 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, after which the liquid crystal phase was observed. For example, when a sample remained in the nematic phase at -20°C and changed to a crystalline or smectic phase at -30°C, T C This was written as <-20℃.

[0134] Viscosity (bulk viscosity; η; measured at 20°C; mPa·s): An E-type rotational viscometer manufactured by Tokyo Keiki Co., Ltd. was used for the measurements.

[0135] Viscosity (rotational viscosity; γ1; measured at 25℃; mPa·s): The measurements were 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 element with a twist angle of 0° and a cell gap of 5 μm between the two glass substrates. A voltage was applied to this element in increments of 0.5 V in the range of 16 V to 19.5 V. After a 0.2 second period of no application, the application was repeated under the condition of a single square wave (square pulse; 0.2 seconds) followed by no application (2 seconds). The peak current and peak time of the transient current generated by this application were measured. The rotational viscosity value was obtained from these measurements and the calculation formula (8) described on page 40 of M. Imai et al.'s paper. The dielectric anisotropy value required for this calculation was determined using the element in which the rotational viscosity was measured, by the method described below.

[0136] Refractive index anisotropy (for Δn < 0.30; measured at 25°C): The measurement was performed using light with a wavelength of 589 nm and an Abbe refractometer with a polarizing plate attached to the eyepiece. After rubbing the surface of the main prism in one direction, the sample was dropped onto the main prism. Refractive index n ∥ The measurement was taken when the direction of polarization was parallel to the direction of rubbing. Refractive index n ⊥The measurement was taken when the direction of polarization was perpendicular to the direction of rubbing. The refractive index anisotropy value is given by Δn=n ∥ -n ⊥ It was calculated from the formula.

[0137] Refractive index anisotropy (for Δn≧0.30; measured at 25℃): A sample was placed in an element composed of two glass substrates and oriented antiparallel. The retardation (Rth) in the thickness direction 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 the refractive index anisotropy (Δn) was calculated from the retardation value (Rth) and the gap between the glass substrates (d: cell gap) using the following formula. The wavelength of the light used was 589 nm. Rth = Δn·d

[0138] Dielectric anisotropy (Δε; measured at 25℃): The sample was placed in a TN element with a cell gap of 9 μm between two glass substrates and a twist angle of 80 degrees. A sine wave (10V, 1kHz) was applied to this element, and after 2 seconds, the dielectric constant (ε) in the long axis direction of the liquid crystal molecules was measured. ∥ The dielectric constant (ε) in the short axis direction of the liquid crystal molecule was measured. A sine wave (0.5V, 1kHz) was applied to this element, and after 2 seconds, the dielectric constant (ε) in the short axis direction of the liquid crystal molecule was measured. ⊥ The dielectric anisotropy was measured. The value of the dielectric anisotropy is Δε = ε ∥ -ε ⊥ It was calculated from the formula.

[0139] Voltage retention rate (VHR; measured at 25°C; %): The cell used for the measurement had the following structure: ITO electrodes and rubbed polyimide alignment films were arranged on each substrate in this order. Two of these substrates were bonded together with the alignment film surfaces facing inward, so that the angle of the rubbing direction between the upper and lower substrates was 90 degrees. The distance between the two glass substrates (cell gap) was 5 μm. A liquid crystal composition was sealed inside this cell. This TN element was charged by applying a pulse voltage (5V for 60 microseconds). The decaying voltage was measured with a high-speed voltmeter for 16.7 milliseconds, and the area A between the voltage curve and the horizontal axis in a unit period was determined. Area B was the area when there was no decay. The voltage retention rate was expressed as the percentage of area A to area B.

[0140] Dielectric anisotropy at 28 GHz (measured at room temperature): The dielectric anisotropy at 28 GHz (Δε@28 GHz) was determined by filling a variable short-circuit waveguide fitted with a window material with liquid crystal and holding it in a static magnetic field of 0.3 T for 3 minutes, using the method disclosed in Applied Optics, Vol. 44, No. 7, p1150 (2005). A 28 GHz microwave was input to the waveguide, and the amplitude ratio of the reflected wave to the incident wave was measured. Measurements were taken by changing the direction of the static magnetic field and the length of the short-circuit waveguide to determine the refractive index (n: ne, no) and loss parameters (α: αe, αo). The complex permittivity (ε',ε") was calculated using the calculated refractive index, loss parameters, and the following relationship. ε'=n 2 -κ 2 ε”=2nκ α = 2ωκ / c Here, c is the speed of light in a vacuum, ω is the angular velocity, and κ is the extinction coefficient. e from ε' ∥ n o from ε' ⊥ The dielectric anisotropy (Δε@28GHz) is calculated as ε' ∥ -ε' ⊥ It was calculated from that.

[0141] Dielectric loss tangent (tanδ; measured at room temperature) at 28 GHz: The dielectric loss tangent at 28 GHz (tanδ@28 GHz) was calculated using the complex permittivity (ε', ε") from ε" / ε'. Since anisotropy also occurs in tanδ, the larger value is listed.

[0142] [Example 1] Synthesis of compound (1-6): 4-((2,5-difluoro-4-isothiocyanatophenyl)ethynyl)-3-fluoro-4'-(4-pentylcyclohexyl)-1,1'-biphenyl TIFF2026099717000029.tif22108

[0143] Commercial raw materials 1-bromo-3-fluoro-4-iodobenzene (50 g), triethylamine (150 mL), and THF (100 mL) were transferred to a reaction vessel. A solution of 2-methyl-3-buty-2-ol (15.1 g) in THF (50 mL) was transferred to a dropping funnel and attached to the reaction vessel, and the vessel was purged with nitrogen. The catalysts CuI (0.6 g) and PdCl2(PPh3)2 (1.2 g) were added, and the addition was started dropwise at room temperature with stirring. After the addition was complete, the mixture was stirred at room temperature for 2 hours. Pure water, ammonium chloride, and toluene were added to the reaction solution, and the organic layer was washed twice with pure water. The organic layer was concentrated. The mixture was purified by silica gel column chromatography (eluent: toluene), and recrystallized from heptane to obtain intermediate 1 (40.7 g). The structure of the compound obtained by NMR measurement was confirmed. 1 H-NMR (δppm: CDCl3): 7.28~7.21 (m, 3H), 2.24 (s, 1H), 1.63 (s, 6H).

[0144] Under a nitrogen atmosphere, 4,4,5,5-tetramethyl-2-(4-(4-pentylcyclohexyl)phenyl)-1,3,2-dioxaborolane (50 g), intermediate 1 (36.1 g), potassium carbonate (38.8 g), toluene (350 mL), ethanol (150 mL), and pure water (150 mL) were mixed with Pd-132 (Johnson Matthey) (1.0 g) and heated and stirred at 80°C for 1 hour. After cooling to room temperature, pure water and toluene were added, and the organic layer was washed with pure water and concentrated to obtain a solid. The solid was purified by silica gel column chromatography (eluent: toluene), and intermediate 2 (44 g) was obtained by recrystallization from boiling toluene / heptane = 4 / 6 (volume ratio). The structure of the compound obtained by NMR measurement was confirmed. 1 H-NMR (δppm: CDCl3): 7.49 (d, 2H), 7.44 (t, 1H), 7.33~7.27 (m, 4H), 2.51 (tt, 1H), 2.08 (s, 1H), 1.90(m, 4H), 1.65(s, 6H), 1.47(m, 2H), 1.37~1.20(m, 9H), 1.06(m, 2H), 0.90(t, 3H).

[0145] Under a nitrogen atmosphere, intermediate 2 (44 g) and toluene (440 mL) were mixed with KOH (6.7 g) and heated and stirred at 120 °C for 2 hours. After cooling to room temperature, the mixture was neutralized with dilute hydrochloric acid, and the organic layer was washed twice with pure water and concentrated. The resulting solid was purified by silica gel column chromatography (developing agent: toluene / heptane = 1 / 9 (volume ratio)), and intermediate 3 (29 g) was obtained by recrystallization from heptane. The structure of the compound obtained by NMR measurement was confirmed. 1 H-NMR (δppm: CDCl3): 7.51 (t, 1H), 7.49 (d, 2H), 7.34~7.28 (m, 4H), 3.34 (s, 1H), 2. 51(tt, 1H), 1.91(m, 4H), 1.48(m, 2H), 1.37~1.20(m, 9H), 1.06(m, 2H), 0.90(t, 3H).

[0146] Under a nitrogen atmosphere, 2,5-difluoro-4-iodoaniline (4.5 g), intermediate 3 (7 g), triethylamine (20 mL), and THF (20 mL) were mixed with CuI (0.07 g) and Pd(PPh3)4 (0.22 g), and the mixture was heated and stirred at 40°C for 1 hour. Pure water, ammonium chloride, and toluene were added to the reaction solution, and the organic layer was washed twice with pure water. The organic layer was then concentrated. The mixture was purified by silica gel column chromatography (eluent: toluene), and recrystallized from toluene / heptane = 15 / 85 (volume ratio) to obtain intermediate 4 (8.9 g). The structure of the compound obtained by NMR measurement was confirmed. 1 H-NMR(δppm:CDCl3):7.53(t, 1H), 7.51(d, 2H), 7.35(dd, 1H), 7.32(dd, 1H), 7.29(d, 2H), 7.14(dd, 1H), 6.50 (dd, 1H), 4.03(s, 2H), 2.51(tt, 1H), 1.90(m, 4H), 1.47(m, 2H), 1.37~1.20(m, 9H), 1.06(m, 2H), 0.90(t, 3H).

[0147] Intermediate 4 (8.9g), 1,1'-thiocarbonyldiimidazole (10g), and THF (70mL) were heated and stirred at 80°C for 1 hour. The reaction solution was concentrated and purified by silica gel column chromatography (eluent: toluene / heptane = 2 / 8 (volume ratio)), and recrystallized from boiling heptane to obtain compound (1-6): 4-((2,5-difluoro-4-isothiocyanatophenyl)ethynyl)-3-fluoro-4'-(4-pentylcyclohexyl)-1,1'-biphenyl. The structure of the compound obtained by NMR measurement was confirmed. 1H-NMR (δppm: CDCl3): 7.56 (t, 1H), 7.52 (d, 2H), 7.38 (dd, 1H), 7.34~7.29 (m, 4H), 6.94 (dd, 1H), 2.52(tt, 1H), 1.91(m, 4H), 1.48(m, 2H), 1.37~1.20(m, 9H), 1.07(m, 2H), 0.90(t, 3H).

[0148] [Example 2] Synthesis of compound (1-8): 3-fluoro-4-((5-fluoro-4-isothiocyanato-2-methylphenyl)ethynyl)-4'-(4-propylcyclohexyl)-1,1'-biphenyl Using the same method as described in the synthesis examples above, compounds represented by formulas (1-8) were synthesized. The structure of the compound obtained by NMR measurement was confirmed. 1 H-NMR(δppm:CDCl3):7.53(t, 1H), 7.52(d, 2H), 7.38(dd, 1H), 7.34(dd, 1H), 7.30(d, 2H), 7.29(d, 1H), 7.05 (d, 1H), 2.52(tt, 1H), 2.46(s, 3H), 1.90(m, 4H), 1.48(m, 2H), 1.40~1.20(m, 5H), 1.07(m, 2H), 0.91(t, 3H).

[0149] [Example 3] Synthesis of compound (1-5): 4-((3,5-difluoro-4-isothiocyanatophenyl)ethynyl)-2-fluoro-5-methyl-4'-(4-pentylcyclohexyl)-1,1'-biphenyl Using the same method as described in the synthesis examples above, compounds represented by formulas (1-5) were synthesized. The structure of the compound obtained by NMR measurement was confirmed. 1H-NMR (δppm: CDCl3): 7.48 (dd, 2H), 7.31~7.28 (m, 3H), 7.24 (d, 1H), 7.12 (d, 2H), 2.51 (tt , 1H), 2.48(s, 3H), 1.91(m, 4H), 1.48(m, 2H), 1.37~1.20(m, 9H), 1.07(m, 2H), 0.90(t, 3H).

[0150] [Example 4] Synthesis of compound (1-10): 1-fluoro-2-((4-isothiocyanatophenyl)ethynyl)-4-methyl-5-((4-(4-pentylcyclohexyl)phenyl)ethynyl)benzene Using the same method as described in the synthesis examples above, compounds represented by formula (1-10) were synthesized. The structure of the compound obtained by NMR measurement was confirmed. 1 H-NMR (δppm: CDCl3): 7.52 (d, 2H), 7.45 (d, 2H), 7.34 (d, 1H), 7.23~7.20 (m, 5H), 2.49 (tt, 1H), 2.45(s, 3H), 1.89(m, 4H), 1.45(m, 2H), 1.36~1.20(m, 9H), 1.05(m, 2H), 0.90(t, 3H).

[0151] The compounds in the examples are represented by symbols based on the definitions in Table 2. The number in parentheses after the symbol corresponds to the compound number. The symbol (-) indicates other liquid crystalline compounds. The percentage of liquid crystalline compounds is expressed as weight percentage (wt%) based on the weight of the liquid crystal composition. Finally, the characteristic values ​​of the composition are summarized.

[0152] TIFF2026099717000038.tif248156

[0153] [Comparative Example 1] Liquid Crystal Composition C1 3-BTB(2Me)-NCS (2-5) 20% 4-BTB(2Me)-NCS (2-5) 10% 5-BTB(2Me)-NCS (2-5) 15% 3-BB(F)TB(2Me,5F)-NCS (3-5) 10% 3-BB(F)TB(Me)-NCS (3-9) 13% 5-BB(F)TB(Me)-NCS (3-9) 12% 3-BB(F)B(F,F)-NCS (-) 10% 3-BTB(2Me,5F)TB-NCS (-) 10% NI=101.2℃;Tc<-40℃;Δn=0.471;Δε=14.6 The dielectric anisotropy (Δε@28GHz) and dielectric loss tangent (tanδ@28GHz) of liquid crystal composition C1 at 28GHz were as follows. Δε@28GHz=1.27 tanδ@28GHz=0.006

[0154] [Example 5] Liquid crystal composition M1 5-HBB(F)TB(2F,5F)-NCS (1-6) 10% 3-BTB(2Me)-NCS (2-5) 15% 5-BTB(2Me)-NCS (2-5) 12% 3-BB(F)TB(2Me,5F)-NCS (3-5) 15% 3-BB(F)TB(Me)-NCS (3-9) 10% 5-BB(F)TB(Me)-NCS (3-9) 10% 3-BB(F)B(F,F)-NCS (-) 18% 3-BTB(2Me,5F)TB-NCS (-) 10% NI=155.1℃;Tc<-40℃;Δn=0.509;Δε=15.7 The dielectric anisotropy (Δε@28GHz) and dielectric loss tangent (tanδ@28GHz) of liquid crystal composition M1 at 28GHz were as follows. Δε@28GHz=1.32 tanδ@28GHz=0.006

[0155] By adding compound (1) to Comparative Example 1, the composition consisting of compounds (1) through (3) corresponds to Example 5. Here, the Δε@28GHz of the composition of Comparative Example 1 is 1.27, while the Δε@28GHz of the composition of Example 5 is 1.32, which is larger. The tanδ@28GHz is 0.006 in both cases, which is small. Furthermore, the upper temperature limit of Comparative Example 1 was 101.2℃ and the lower temperature limit was <-40℃, while the upper temperature limit of Example 5 was 155.1℃ and the lower temperature limit was <-40℃. It was confirmed that applying compound (1) allows for obtaining a liquid crystal composition having a nematic phase over a wider temperature range.

[0156] [Example 6] Liquid crystal composition M2 3-HBB(F)TB(2Me,5F)-NCS (1-8) 10% 3-BTB(2Me)-NCS (2-5) 15% 5-BTB(2Me)-NCS (2-5) 12% 3-BB(F)TB(2Me,5F)-NCS (3-5) 15% 3-BB(F)TB(Me)-NCS (3-9) 10% 5-BB(F)TB(Me)-NCS (3-9) 10% 3-BB(F)B(F,F)-NCS (-) 18% 3-BTB(2Me,5F)TB-NCS (-) 10% NI=154.2℃;Tc<-30℃;Δn=0.506;Δε=15.9 The dielectric anisotropy (Δε@28GHz) and dielectric loss tangent (tanδ@28GHz) of liquid crystal composition M2 at 28GHz were as follows. Δε@28GHz=1.32 tanδ@28GHz=0.007

[0157] [Example 7] Liquid crystal composition M3 5-HBB(2F,5Me)TB(F,F)-NCS (1-5) 10% 3-BTB(2Me)-NCS (2-5) 15% 5-BTB(2Me)-NCS (2-5) 12% 3-BB(F)TB(2Me,5F)-NCS (3-5) 15% 3-BB(F)TB(Me)-NCS (3-9) 10% 5-BB(F)TB(Me)-NCS (3-9) 10% 3-BB(F)B(F,F)-NCS (-) 18% 3-BTB(2Me,5F)TB-NCS (-) 10% NI = 147.5 °C; Tc < -30 °C; Δn = 0.494; Δε = 15.8 The dielectric anisotropy (Δε@28GHz) and dielectric loss tangent (tanδ@28GHz) of liquid crystal composition M3 at 28 GHz were as follows. Δε@28GHz = 1.30 tanδ@28GHz = 0.006

[0158] [Example 8] Liquid crystal composition M4 3-HBB(F)TB(2Me,5F)-NCS (1-8) 10% 3-BTB(2Me)-NCS (2-5) 20% 4-BTB(2Me)-NCS (2-5) 10% 5-BTB(2Me)-NCS (2-5) 15% 3-BB(F)TB(2Me,5F)-NCS (3-5) 10% 3-BB(F)TB(Me)-NCS (3-9) 8% 5-BB(F)TB(Me)-NCS (3-9) 7% 3-BTB(2Me,5F)TB-NCS (-) 10%5-BB(F)TB(2Me)B(3Me,5Me)-NCS (-) 10% NI = 125.1 °C; Tc < -40 °C; Δn = 0.478; Δε = 12.6 The dielectric anisotropy (Δε@28GHz) and dielectric loss tangent (tanδ@28GHz) of liquid crystal composition M4 at 28 GHz were as follows. Δε@28GHz = 1.28 ​tanδ at 28 GHz = 0.006

[0159] [Example 9] Liquid crystal composition M5 5-HBTB(2Me,5F)TB-NCS (1 - 10) 10% 3-BTB(2Me)-NCS (2 - 5) 20% 4-BTB(2Me)-NCS (2 - 5) 10% 5-BTB(2Me)-NCS (2 - 5) 15% 3-BB(F)TB(2Me,5F)-NCS (3 - 5) 10% 3-BB(F)TB(Me)-NCS (3 - 9) 13% 5-BB(F)TB(Me)-NCS (3 - 9) 12% 3-BTB(2Me,5F)TB-NCS (-) 10% NI = 120.0°C; Tc < -40°C; Δn = 0.485; Δε = 11.9 The dielectric anisotropy (Δε at 28 GHz) and dielectric loss tangent (tanδ at 28 GHz) of the liquid crystal composition M5 were as follows. Δε at 28 GHz = 1.23 tanδ at 28 GHz = 0.006

[0160] [Example 10] Liquid crystal composition M6 5-HBB(2Me,5F)TB(F,F)-NCS (1 - 5) 10% 4-BTB(F,F)-NCS (2 - 2) 7% 3-BTB(2Me)-NCS (2 - 5) 10% 5-BTB(2Me)-NCS (2 - 5) 10% 3-BB(F)TB(2Me,5F)-NCS (3 - 5) 15% 3-BB(F)TB(Me)-NCS (3 - 9) 10% 5-BB(F)TB(Me)-NCS (3 - 9) 10% 3-BB(F)B(F,F)-NCS (-) 18% 3-BTB(2Me,5F)TB-NCS (-) 10% NI=148.1℃;Tc<-30℃;Δn=0.488;Δε=16.8 The dielectric anisotropy (Δε@28GHz) and dielectric loss tangent (tanδ@28GHz) of liquid crystal composition M6 at 28GHz were as follows. Δε@28GHz=1.31 tanδ@28GHz=0.007

[0161] [Example 11] Liquid crystal composition M7 5-HBB(2Me,5F)TB(F,F)-NCS (1-5) 10% 3-BTB(2Me)-NCS (2-5) 10% 5-BTB(2Me)-NCS (2-5) 10% 3-BTB(Me)-NCS (2-6) 7% 3-BB(F)TB(2Me,5F)-NCS (3-5) 15% 3-BB(F)TB(Me)-NCS (3-9) 10% 5-BB(F)TB(Me)-NCS (3-9) 10% 3-BB(F)B(F,F)-NCS (-) 18% 3-BTB(2Me,5F)TB-NCS (-) 10% NI=145.6℃;Tc<-30℃;Δn=0.490;Δε=16.1 The dielectric anisotropy (Δε@28GHz) and dielectric loss tangent (tanδ@28GHz) of liquid crystal composition M7 at 28GHz were as follows. Δε@28GHz=1.34 tanδ@28GHz=0.006

[0162] The compositions of Examples 5 to 11 each contain compound (1) to compound (3). The liquid crystal compositions containing compound (1) to compound (3) maintained the basic performance of a liquid crystal composition while keeping Δε@28GHz high and reducing the value of tanδ@28GHz. In particular, the liquid crystal composition containing compound (1) has a very high upper temperature limit while maintaining a low lower temperature limit.

[0163] The properties required of a liquid crystal composition are a large dielectric anisotropy (Δε) that enables large phase control in the frequency range used for phase control, and a small dielectric loss tangent (tanδ) that is proportional to the absorption energy of the electromagnetic wave signal of the liquid crystal composition. From the results of the examples and comparative examples, it was proven that the composition of the present invention has a large dielectric anisotropy (Δε@28GHz) and a small dielectric loss tangent (tanδ@28GHz). In general, a small tanδ results in a lower absorption energy of electromagnetic waves. Therefore, a liquid crystal composition using the compound represented by formula (1) can lower the absorption energy of the electromagnetic wave signal and set the loss of the electromagnetic wave signal to be smaller. From the above, it can be concluded that the liquid crystal composition of the present invention can transmit electromagnetic wave signals more efficiently. [Industrial applicability]

[0164] The liquid crystalline compounds of the present invention can provide liquid crystalline compounds that satisfy at least one of the physical properties of a compound, such as thermal stability, high transparency, very large refractive index anisotropy, and excellent compatibility with other liquid crystalline compounds. Compositions containing the compounds of the present invention can satisfy at least one of the properties of a composition, such as large dielectric anisotropy (large refractive index anisotropy), small dielectric loss tangent (tanδ) in the frequency range used for electromagnetic wave control, and large dielectric anisotropy at low frequencies for reducing the driving voltage, while having a high upper limit temperature of the nematic phase and a low lower limit temperature of the nematic phase. Furthermore, it is possible to provide a more preferable liquid crystalline composition by further satisfying at least one of the properties of the composition, such as a liquid crystalline composition having low viscosity, high resistivity in the driving frequency range, and thermal stability. Devices containing this composition can be used to control electromagnetic wave signals with frequencies in the range of 1 GHz to 10 THz.

Claims

1. A compound represented by formula (1). In equation (1), R １ is hydrogen, a halogen, or an alkyl group having 1 to 12 carbon atoms, wherein the alkyl group contains at least one -CH ２ - may be replaced with -O- or -S-, and at least one -(CH ２ ) ２ The - can be replaced with -CH=CH- or -C≡C-, and in these groups, at least one hydrogen can be replaced with a halogen; L １ , L ２ , L ３ and L ４ These are hydrogen, fluorine, chlorine, methyl, or ethyl; Y １ and Y ２ is hydrogen, fluorine or chlorine; n is either 0 or 1. However, when n is 0, L １ , L ２ , L ３ and L ４ It is not possible for any two of them to be methyl, while the other two are hydrogen, fluorine, chlorine, or ethyl.

2. The compound according to claim 1, wherein the compound represented by formula (1) is represented by any one of formulas (1-1) to (1-18). In equations (1-1) to (1-18), R １’ This is an alkyl group having 1 to 12 carbon atoms, and in this alkyl group, at least one -CH group ２ - may be replaced with -O- or -S-, and at least one -(CH ２ ) ２ The - can be replaced with -CH=CH- or -C≡C-, and in these groups, at least one hydrogen can be replaced with a halogen; L １’ is fluorine or methyl, L ２’ is hydrogen, fluorine, or methyl; Y １’ It is either hydrogen or fluorine. However, in equations (1-1), (1-2), (1-5), (1-6), and (1-9), L １’ and L ２’ They cannot be methyl at the same time; In equations (1-3), (1-4), (1-7), and (1-8), L １’ and L ２’ It is impossible for only one of them to be methyl.

3. A liquid crystal composition containing at least one compound according to claim 1 or 2.

4. The liquid crystal composition according to claim 3, further comprising at least one compound selected from the compounds represented by formula (2) and formula (3). In equations (2) and (3), R ２ and R ３ is hydrogen, a halogen, or a linear alkyl group having 1 to 12 carbon atoms, wherein the alkyl group contains at least one -CH ２ - may be replaced with -O- or -S-, and at least one -(CH ２ ) ２ The - can be replaced with -CH=CH- or -C≡C-, and in these groups, at least one hydrogen can be replaced with a halogen; L ２１ , L ２２ , L ２３ , L ３１ , L ３２ and L ３３ These are hydrogen, halogens, C1-C3 alkyl groups, C1-C3 fluorinated alkyl groups, or C3-C5 cycloalkyl groups; Y ２１ , Y ３１ , Y ３２ , Y ３３ , Y ３４ , Y ３５ and Y ３６ It is either hydrogen or a halogen.

5. The liquid crystal composition according to claim 4, wherein the compound represented by formula (2) is at least one compound selected from the group of compounds represented by formulas (2-1) to (2-10). In equations (2-1) to (2-10), R ２’ This is a linear alkyl group having 1 to 12 carbon atoms, and in this alkyl group, at least one -(CH ２ ) ２ The minus sign can be replaced with -CH=CH- or -C≡C-.

6. The liquid crystal composition according to claim 4, wherein the compound represented by formula (3) is at least one compound selected from the group of compounds represented by formulas (3-1) to (3-11). In equations (3-1) to (3-11), R ３’ This is a linear alkyl group having 1 to 12 carbon atoms, and in this alkyl group, at least one -(CH ２ ) ２ The hyphen can be replaced with -CH=CH- or -C≡C-; Y ３５’ These are hydrogen, fluorine, or chlorine.

7. The liquid crystal composition according to claim 4, wherein, based on the weight of the liquid crystal composition, the proportion of the compound represented by formula (1) in claim 1 is in the range of 5% to 25% by weight, and the proportion of the compound represented by formula (2) is in the range of 10% to 55% by weight.

8. The liquid crystal composition according to claim 4, wherein, based on the weight of the liquid crystal composition, the proportion of the compound represented by formula (1) in claim 1 is in the range of 5% to 25% by weight, and the proportion of the compound represented by formula (3) is in the range of 20% to 50% by weight.

9. The liquid crystal composition according to claim 4, wherein, based on the weight of the liquid crystal composition, the proportion of the compound represented by formula (1) in claim 1 is in the range of 5% to 25% by weight, the proportion of the compound represented by formula (2) is in the range of 10% to 55% by weight, and the proportion of the compound represented by formula (3) is in the range of 20% to 50% by weight.

10. The liquid crystal composition according to claim 3, wherein the refractive index anisotropy at 25°C at a wavelength of 589 nm is 0.40 or more.

11. The liquid crystal composition according to claim 3, wherein the dielectric anisotropy at 25°C at a frequency of 1 kHz is 10 or more.

12. The liquid crystal composition according to claim 3, wherein the dielectric anisotropy at 25°C in the range of 1.0 to 3.0 in at least one frequency range from 1 GHz to 10 THz.

13. The liquid crystal composition according to claim 3, comprising an optically active compound.

14. The liquid crystal composition according to claim 3, comprising a polymerizable compound.

15. The liquid crystal composition according to claim 3, further comprising at least one of an antioxidant, an ultraviolet absorber, an antistatic agent, and a dichroic dye.

16. An element containing the liquid crystal composition described in claim 3, wherein the dielectric constant can be reversibly controlled by reversibly changing the orientation direction of the liquid crystal molecules, and which is used as an element for switching.

17. An element used for electromagnetic wave control in the frequency range of 1 GHz to 10 THz, comprising the liquid crystal composition described in claim 3.

18. A liquid crystal lens, a birefringent lens for displaying stereoscopic images, or an optical modulation element containing the liquid crystal composition described in claim 3.

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