JP2023075037A - Liquid crystal composition and liquid crystal element - Google Patents

Abstract

To provide a liquid crystal composition that is a material for use in an element for control of electromagnetic wave signals from 1 GHz to 10 THz in frequency, and meets at least one property of a wide temperature range of a nematic phase, large refractive-index anisotropy and small dielectric loss tangent, and an element comprising the composition.SOLUTION: A liquid crystal composition comprises at least one compound selected from the group of compounds represented by the formula (1). (R11 is H, a halogen, a C1-11 alkoxy or the like; R12 is H, a halogen, a C1-12 alkyl or the like; a ring W is, for example, illustrated below; L11 and L12 are each a C1-3 alkyl or the like; a ring A11 and a ring A12 are each 1,4-phenylene or the like; Z11 and Z12 are each -C≡C- or the like; a and b are each an integer of 0-4, where the sum of a and b is 1 or more and 4 or less).SELECTED DRAWING: None

Description

The present invention relates to a liquid crystal composition having a nematic phase and positive dielectric anisotropy and a device containing the same. In particular, the present invention relates to a liquid crystal composition used for controlling electromagnetic waves in the frequency range of 1 GHz to 10 THz and a device containing the same.

As a new use of liquid crystal compositions, which are often used for displays, attention has been paid to the application of liquid crystal compositions to high-frequency technology such as antennas for transmitting and receiving electromagnetic waves.

Specific examples of elements used for controlling electromagnetic waves in the frequency range of 1 GHz to 10 THz include millimeter wave band or microwave band antennas, infrared laser elements, and the like. Various systems have been studied for these elements, but a system using a liquid crystal composition, which is considered to be less likely to fail because it has no mechanically movable parts, is attracting attention.

A liquid crystal composition having dielectric anisotropy has a frequency (relaxation frequency) lower than the frequency at which alignment polarization is relaxed (relaxation frequency) (from several 100 kHz to several 100 MHz). Dielectric constants in different directions.
At frequencies higher than the relaxation frequency, that is, in the range from microwaves to terahertz waves (approximately 10 THz), the difference in dielectric constant between the vertical direction and the horizontal direction with respect to the alignment direction of the liquid crystal composition is observed, although the value is small. There is dielectric anisotropy (Non-Patent Document 1). Therefore, the liquid crystal composition can change the dielectric constant in one direction by changing the alignment direction of the molecules according to the external field (electric field).

By utilizing this property, the liquid crystal composition can change the orientation of the molecules in response to an external electric field and change the dielectric constant. For example, it is possible to realize a microwave device that can electrically control the transmission characteristics of a high-frequency transmission line from the outside. Such devices include a voltage-controlled millimeter wave band variable phase shifter in which a nematic liquid crystal composition is filled in a waveguide, and a microwave/millimeter wave band in which a nematic liquid crystal composition is used as a dielectric substrate for a microstrip line. Wideband variable phase shifters and the like have been reported (Patent Documents 1 and 2).

Moreover, in recent years, research has progressed on metamaterial technology that exhibits behavior that is not found in natural substances in response to electromagnetic waves, including light. Due to its characteristics, it is applied to technical 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 a transmission line using a metamaterial, the use of a liquid crystal composition that can change the orientation of molecules in response to an external electric field and change the dielectric constant is also considered.

Elements used for such electromagnetic wave control desirably have characteristics such as high gain and low loss. Considering the phase control of high-frequency signals, the properties required of the liquid crystal composition are a large dielectric anisotropy that enables a large phase control in the frequency region used for phase control, and the electromagnetic wave of the liquid crystal composition. A dielectric loss tangent (tan δ) proportional to the absorbed energy of a signal is required to be small (Non-Patent Document 1).

Since the liquid crystal composition is a dielectric, it generates polarization (dielectric polarization) with respect to an external field (electric field). Permittivity is a physical quantity that indicates the response of a dielectric to an electric field, and the magnitude of the permittivity is related to dielectric polarization. The mechanism by which dielectric polarization occurs can be roughly divided into three. They are electronic polarization, ionic polarization, and orientational polarization. Orientation polarization is polarization accompanying the orientation of the dipole moment, and as described above, relaxation occurs at frequencies from several hundred kHz to several hundred MHz, the orientation polarization becomes smaller, and the dielectric constant becomes smaller. Ionic polarization, on the other hand, is polarization caused by the movement of ion atoms, and relaxation occurs in the infrared region. Based on the frequency at which orientational polarization occurs, it is considered that there is no large polarization between the frequencies at which ion polarization occurs, so there is no significant change in the dielectric constant between them. As a result, only electronic polarization and ionic polarization are involved in dielectric polarization at high frequencies (in the range of microwaves to terahertz waves (approximately 10 THz)). In a lossless dielectric, the relationship between the dielectric constant and the refractive index is ε= ⁿ² . It is considered that the dielectric anisotropy (Δε) in the high frequency region increases as the (Δn) increases (Non-Patent Document 2). Therefore, it is preferable that the liquid crystal composition has a large refractive index anisotropy.

Also, a low drive voltage is desirable to achieve switching characteristics and high energy efficiency of the device. Therefore, the liquid crystal composition preferably has a large dielectric anisotropy even at low frequencies (frequencies lower than the relaxation frequency).

In addition, elements used for electromagnetic wave control are required to have a wide operating temperature range and a short response time. A low minimum temperature limit, thermal stability, and low viscosity are also required.

Liquid crystal compositions used in conventional devices are disclosed in Patent Documents 3 to 4 below.

WO2017/201515 WO2017/208996 JP 2004-285085 A JP 2011-74074 A

EKISHO, Vol. 23 (No. 1), (2019), pp. 51-55 Dielectric Phenomenon Theory The Institute of Electrical Engineers of Japan Ohmsha Co., Ltd. July 25, 1973 pp.92-95

As a material for devices used for electromagnetic wave control, liquid crystal compositions have a high upper limit temperature of the nematic phase and a low lower limit temperature of the nematic phase, while exhibiting a large dielectric anisotropy (large refractive index anisotropy), small dielectric loss tangent (tan δ), and large dielectric anisotropy at low frequencies for driving voltage reduction, more preferably small viscosity, large resistivity in the driving frequency region and thermal stability.

However, as a liquid crystal composition for use in elements used for such electromagnetic wave control, liquid crystal compositions used for conventional display applications and the like are insufficient in terms of characteristics. This is because they have poor properties for use in high frequency control applications, such as high insertion loss and/or poor phase shift.

The development of liquid crystal materials for devices used for electromagnetic wave control is still in its infancy, and attempts are being made to develop novel compounds that enable the optimization of such devices in order to improve the characteristics of high frequency control. always done. A unique liquid crystal medium is required for use as a material for devices used in electromagnetic wave control.

An object of the present invention is to provide a liquid crystal composition which satisfies the above-mentioned required properties and has an excellent property balance as a material for use in an element for controlling electromagnetic waves in the frequency range of 1 GHz to 10 THz. .

As a result of intensive studies by the inventors, it was found that a liquid crystal composition containing at least one compound selected from the group of compounds represented by formula (1), which are liquid crystal compounds having a specific structure, solves the above problems. The present invention was completed by discovering that it does.

The present invention includes the following items.

式（１）において、
Ｒ^１１は、水素、ハロゲン、または炭素数１から１２のアルキルであり、このアルキルにおいて、少なくとも１つの－ＣＨ_２－は、－Ｏ－または－Ｓ－で置き換えられてもよく、少なくとも１つの－（ＣＨ_２）_２－は、－ＣＨ＝ＣＨ－または－Ｃ≡Ｃ－で置き換えられてもよく、これらの基において、少なくとも１つの水素は、ハロゲンで置き換えられてもよく；
Ｒ^１２は、水素、ハロゲン、－Ｃ≡Ｎ、－Ｎ＝Ｃ＝Ｓ、－Ｃ≡Ｃ－Ｃ≡Ｎ、または炭素数１から１２のアルキルであり、このアルキルにおいて、少なくとも１つの－ＣＨ_２－は、－Ｏ－または－Ｓ－で置き換えられてもよく、少なくとも１つの－（ＣＨ_２）_２－は、－ＣＨ＝ＣＨ－または－Ｃ≡Ｃ－で置き換えられてもよく、これらの基において、少なくとも１つの水素は、ハロゲンで置き換えられてもよく；
環Ｗは、

または

であり、これらの環上の少なくとも１つの水素はハロゲンで置き換えられてもよく；
Ｌ^１１は、炭素数１から３のアルキルであり、Ｌ^１２は、水素または炭素数１から３のアルキルであり；
環Ａ^１１および環Ａ^１２は、１，４－シクロヘキシレン、１，４－シクロヘキセニレン、１，４－フェニレン、テトラヒドロピラン－２，５－ジイル、１，３－ジオキサン－２，５－ジイル、ピリミジン－２，５－ジイル、２，６，７－トリオキサビシクロ［２．２．２］オクタン－１，４－ジイル、ナフタレン－２，６－ジイル、またはピリジン－２，５－ジイルであり、これらの環上の少なくとも１つの水素は、ハロゲンまたは炭素数１から６のアルキルで置き換えられていてもよく；
Ｚ^１１およびＺ^１２は、単結合または炭素数１から４のアルキレンであり、このアルキレンにおいて、少なくとも１つの－ＣＨ_２－は、－Ｏ－または－ＣＯＯ－で置き換えられてもよく、少なくとも１つの－（ＣＨ_２）_２－は、－ＣＨ＝ＣＨ－、－Ｃ≡Ｃ－、または－Ｃ≡Ｃ－Ｃ≡Ｃ－で置き換えられてもよく、これらの基において、少なくとも１つの水素はハロゲンで置き換えられてもよく；
ａおよびｂは、０、１、２、３、または４であり、ａおよびｂの和は１以上４以下である。 Section 1. A liquid crystal composition containing at least one compound selected from the group of compounds represented by formula (1).

In formula (1),
R ¹¹ is hydrogen, halogen, or alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —S—, and at least one — (CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C— and in these groups at least one hydrogen may be replaced by halogen;
R ¹² is hydrogen, halogen, —C≡N, —N═C═S, —C≡C—C≡N, or alkyl having 1 to 12 carbon atoms, wherein at least one —CH ₂ — may be replaced by —O— or —S— and at least one —(CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C—, these groups at least one hydrogen may be replaced with a halogen;
Ring W is

or

and at least one hydrogen on these rings may be replaced by halogen;
L ¹¹ is alkyl having 1 to 3 carbon atoms, and L ¹² is hydrogen or alkyl having 1 to 3 carbon atoms;
Ring A ¹¹ and Ring A ¹² are 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 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 replaced by halogen or alkyl having 1 to 6 carbon atoms;
Z ¹¹ and Z ¹² are a single bond or alkylene having 1 to 4 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —COO— and at least one —(CH ₂ ) ₂ — may be replaced with —CH═CH—, —C≡C—, or —C≡CC≡C— in which at least one hydrogen is halogen; may be replaced;
a and b are 0, 1, 2, 3, or 4, and the sum of a and b is 1 or more and 4 or less.

式（１－１）および式（１－２）において、
Ｒ^１１は、水素、ハロゲン、または炭素数１から１２のアルキルであり、このアルキルにおいて、少なくとも１つの－ＣＨ_２－は、－Ｏ－または－Ｓ－で置き換えられてもよく、少なくとも１つの－（ＣＨ_２）_２－は、－ＣＨ＝ＣＨ－または－Ｃ≡Ｃ－で置き換えられてもよく、これらの基において、少なくとも１つの水素はハロゲンで置き換えられてもよく；
Ｒ^１２は、水素、ハロゲン、－Ｃ≡Ｎ、－Ｎ＝Ｃ＝Ｓ、－Ｃ≡Ｃ－Ｃ≡Ｎ、または炭素数１から１２のアルキルであり、このアルキルにおいて、少なくとも１つの－ＣＨ_２－は、－Ｏ－または－Ｓ－で置き換えられてもよく、少なくとも１つの－（ＣＨ_２）_２－は、－ＣＨ＝ＣＨ－または－Ｃ≡Ｃ－で置き換えられてもよく、これらの基において、少なくとも１つの水素はハロゲンで置き換えられてもよく；
Ｌ^１１は、炭素数１から３のアルキルであり、Ｌ^１２は、水素または炭素数１から３のアルキルであり；
環Ａ^１２は、１，４－シクロヘキシレン、１，４－シクロヘキセニレン、１，４－フェニレン、テトラヒドロピラン－２，５－ジイル、１，３－ジオキサン－２，５－ジイル、ピリミジン－２，５－ジイル、２，６，７－トリオキサビシクロ［２．２．２］オクタン－１，４－ジイル、ナフタレン－２，６－ジイル、またはピリジン－２，５－ジイルであり、これらの環上の少なくとも１つの水素は、ハロゲンまたは炭素数１から６のアルキルで置き換えられていてもよく；
Ｚ^１２は、単結合または炭素数１から４のアルキレンであり、このアルキレンにおいて、少なくとも１つの－ＣＨ_２－は、－Ｏ－または－ＣＯＯ－で置き換えられてもよく、少なくとも１つの－（ＣＨ_２）_２－は、－ＣＨ＝ＣＨ－、－Ｃ≡Ｃ－、または－Ｃ≡Ｃ－Ｃ≡Ｃ－で置き換えられてもよく、これらの基において、少なくとも１つの水素はハロゲンで置き換えられてもよく；
ｂは、１、２、３、または４である。 Section 2. Item 2. The liquid crystal composition according to item 1, containing at least one compound selected from the group of compounds represented by formulas (1-1) and (1-2).

In formulas (1-1) and (1-2),
R ¹¹ is hydrogen, halogen, or alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —S—, and at least one — (CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C— and in these groups at least one hydrogen may be replaced by halogen;
R ¹² is hydrogen, halogen, —C≡N, —N═C═S, —C≡C—C≡N, or alkyl having 1 to 12 carbon atoms, wherein at least one —CH ₂ — may be replaced by —O— or —S— and at least one —(CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C—, these groups at least one hydrogen may be replaced by a halogen;
L ¹¹ is alkyl having 1 to 3 carbon atoms, and L ¹² is hydrogen or alkyl having 1 to 3 carbon atoms;
Ring A ¹² is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 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 these at least one hydrogen on the ring may be replaced by halogen or alkyl having 1 to 6 carbon atoms;
Z ¹² is a single bond or alkylene having 1 to 4 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —COO—, and at least one —(CH ₂ ) _2- may be replaced by -CH=CH-, -C≡C-, or -C≡C-C≡C- in which at least one hydrogen is replaced by halogen; well;
b is 1, 2, 3, or 4;

Item 3. Item 3. The liquid crystal composition according to item 1 or 2, wherein the ratio of the compound represented by formula (1) is in the range of 5% by weight to 75% by weight based on the weight of the liquid crystal composition.

式（２）において、
Ｒ^２は、水素、ハロゲン、または炭素数１から１２のアルキルであり、このアルキルにおいて、少なくとも１つの－ＣＨ_２－は、－Ｏ－または－Ｓ－で置き換えられてもよく、少なくとも１つの－（ＣＨ_２）_２－は、－ＣＨ＝ＣＨ－または－Ｃ≡Ｃ－で置き換えられてもよく、これらの基において、少なくとも１つの水素は、ハロゲンで置き換えられてもよく；
環Ａ^２は、１，４－シクロヘキシレン、１，４－シクロヘキセニレン、テトラヒドロピラン－２，５－ジイル、１，３－ジオキサン－２，５－ジイル、ピリミジン－２，５－ジイル、２，６，７－トリオキサビシクロ［２．２．２］オクタン－１，４－ジイル、ナフタレン－２，６－ジイルまたはピリジン－２，５－ジイルであり、これらの環上の少なくとも１つの水素は、ハロゲンまたは炭素数１から３のアルキルで置き換えられてもよく；
Ｚ^２１およびＺ^２２は、単結合、－Ｃ≡Ｃ－、または－Ｃ≡Ｃ－Ｃ≡Ｃ－であり；
Ｌ^２１、Ｌ^２２、Ｌ^２３、およびＬ^２４は、水素、ハロゲン、炭素数１から３のアルキル、または炭素数３から５のシクロアルキルであり；
Ｘ^２は、ハロゲン、－Ｃ≡Ｎ、－Ｃ≡Ｃ－Ｃ≡Ｎ、または－Ｎ＝Ｃ＝Ｓであり；
Ｙ^２１およびＹ^２２は、水素、ハロゲン、または炭素数１から３のアルキルであり；
ｃは、０または１であり、ｄは０、１、２、または３であり、ｃおよびｄの和は１以上３以下である。 Section 4. 4. The liquid crystal composition according to any one of items 1 to 3, containing at least one compound selected from the group of compounds represented by formula (2).

In formula (2),
R ² is hydrogen, halogen, or alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —S—, and at least one — (CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C— and in these groups at least one hydrogen may be replaced by halogen;
Ring A ² is 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, 2 , 6,7-trioxabicyclo[2.2.2]octane-1,4-diyl, naphthalene-2,6-diyl or pyridine-2,5-diyl, and at least one hydrogen on these rings may be replaced by halogen or alkyl of 1 to 3 carbon atoms;
Z ²¹ and Z ²² are a single bond, —C≡C—, or —C≡C—C≡C—;
L ²¹ , L ²² , L ²³ , and L ²⁴ are hydrogen, halogen, alkyl having 1 to 3 carbon atoms, or cycloalkyl having 3 to 5 carbon atoms;
X ² is halogen, -C≡N, -C≡C-C≡N, or -N=C=S;
Y ²¹ and Y ²² are hydrogen, halogen, or alkyl having 1 to 3 carbon atoms;
c is 0 or 1, d is 0, 1, 2, or 3, and the sum of c and d is 1 or more and 3 or less.

式（２－１）から式（２－８）において、
Ｒ^２’は、炭素数１から１２のアルキルであり、このアルキルにおいて、少なくとも１つの－（ＣＨ_２）_２－は－ＣＨ＝ＣＨ－または－Ｃ≡Ｃ－で置き換えられてもよく；
Ｌ^２１’、Ｌ^２２’、Ｌ^２３’、およびＬ^２４’は、水素、フッ素、塩素、メチル、エチル、またはシクロプロピルであり；
Ｙ^２１’およびＹ^２２’は、水素、フッ素、塩素、メチル、またはエチルである。
Ｘ^２‘は、－Ｃ≡Ｃ－Ｃ≡Ｎまたは－Ｎ＝Ｃ＝Ｓである。 Item 5. Item 5. The liquid crystal composition according to item 4, containing at least one compound selected from the group of compounds represented by formulas (2-1) to (2-8).

In formulas (2-1) to (2-8),
R ^2′ is alkyl having 1 to 12 carbon atoms, in which at least one —(CH ₂ ) ₂ — may be replaced with —CH═CH— or —C≡C—;
L ^21′ , L ^22′ , L ^23′ and L ^24′ are hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl;
Y ^21' and Y ^22' are hydrogen, fluorine, chlorine, methyl, or ethyl.
X ^2' is -C≡CC≡N or -N=C=S.

Item 6. In the compound represented by formula (2),
Item 5. The liquid crystal composition according to item 4, comprising a compound selected from the group of compounds in which ^X2 is -C≡CC≡N.

Item 7. In the compound represented by formula (2),
Item 5. The liquid crystal composition according to Item 4, comprising a compound selected from the group of compounds in which ^X2 is -N=C=S.

Item 8. In the compound represented by formula (2),
Item 5. Item 4, which simultaneously comprises a compound selected from the group of compounds in which X ² is -C≡C—C≡N and a compound selected from the group of compounds in which X ² is -N=C=S liquid crystal composition.

Item 9. 9. The liquid crystal composition according to any one of items 4 to 8, wherein the ratio of the compound represented by formula (2) is in the range of 10% by weight to 70% by weight based on the weight of the liquid crystal composition.

式（３）において、
Ｒ^３１およびＲ^３２は、水素または炭素数１から１２のアルキルであり、このアルキルにおいて、少なくとも１つの－ＣＨ_２－は、－Ｏ－または－Ｓ－で置き換えられてもよく、少なくとも１つの－（ＣＨ_２）_２－は、－ＣＨ＝ＣＨ－または－Ｃ≡Ｃ－で置き換えられてもよく、これらの基において、少なくとも１つの水素は、ハロゲンで置き換えられてもよく；
Ｚ^３１およびＺ^３２は、単結合、－Ｃ≡Ｃ－、または－Ｃ≡Ｃ－Ｃ≡Ｃ－であり；
Ｌ^３１、Ｌ^３２、Ｌ^３３、Ｌ^３４、Ｌ^３５、Ｌ^３６、およびＬ^３７は、水素、ハロゲン、メチル、エチル、またはシクロプロピルであり；
ｅは、０または１である。 Item 10. 10. The liquid crystal composition according to any one of items 1 to 9, containing at least one compound selected from the group of compounds represented by formula (3).

In formula (3),
R ³¹ and R ³² are hydrogen or alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —S— and at least one — (CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C— and in these groups at least one hydrogen may be replaced by halogen;
Z ³¹ and Z ³² are a single bond, —C≡C—, or —C≡C—C≡C—;
^L31 , ^L32 , ^L33 , ^L34 , ^L35 , ^L36 , and ^L37 are hydrogen, halogen, methyl, ethyl, or cyclopropyl;
e is 0 or 1;

式（３－１）から式（３－５）において、
Ｒ^３１‘およびＲ^３２’は、炭素数１から１２のアルキルであり、このアルキルにおいて、少なくとも１つの－ＣＨ_２－は－Ｏ－で置き換えられてもよく、少なくとも１つの－（ＣＨ_２）_２－は、－ＣＨ＝ＣＨ－または－Ｃ≡Ｃ－で置き換えられてもよく；
Ｌ^３１‘、Ｌ^３２’、Ｌ^３３‘、Ｌ^３４’、Ｌ^３５‘、Ｌ^３６’、およびＬ^３７‘は、水素、フッ素、塩素、メチル、またはエチルである。 Item 11. Item 11. The liquid crystal composition according to item 10, containing at least one compound selected from the group of compounds represented by formulas (3-1) to (3-5).

In formulas (3-1) to (3-5),
R ^31′ and R ^32′ are alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— and at least one —(CH ₂ ) ₂ - may be replaced by -CH=CH- or -C≡C-;
L ^31′ , L ^32′ , L ^33′ , L ^34′ , L ^35′ , L ^36′ and L ^37′ are hydrogen, fluorine, chlorine, methyl or ethyl.

Item 12. 12. The liquid crystal composition according to item 10 or 11, wherein the ratio of the compound represented by formula (3) is in the range of 5% by weight to 65% by weight based on the weight of the liquid crystal composition.

Item 13. 13. The liquid crystal composition according to any one of Items 1 to 12, wherein the refractive index anisotropy at 25°C at a wavelength of 589 nm is 0.35 or more.

14. The liquid crystal composition according to any one of items 1 to 13, wherein the dielectric anisotropy at 25°C in a frequency range of less than 14.1 MHz is 2 or more.

Item 15. The liquid crystal composition according to any one of Items 1 to 14, wherein the dielectric anisotropy at 25°C at any frequency of 15.1 GHz to 10 THz is in the range of 0.50 to 3.0.

Item 16. Item 16. The liquid crystal composition according to any one of Items 1 to 15, comprising an optically active compound.

Item 17. Item 17. The liquid crystal composition according to any one of Items 1 to 16, comprising a polymerizable compound.

Item 18. Item 18. The liquid crystal composition according to any one of Items 1 to 17, containing at least one of an antioxidant, an ultraviolet absorber, an antistatic agent, and a dichroic dye.

Item 19. Item 19. A device containing the liquid crystal composition according to any one of items 1 to 18, wherein the dielectric constant can be reversibly controlled by reversibly changing the alignment direction of the liquid crystal molecules, and is used for switching. element.

Item 20. Item 19. A device used for electromagnetic wave control in a frequency range of 1 GHz to 10 THz, containing the liquid crystal composition according to any one of Items 1 to 18.

Item 21. A liquid crystal lens or a birefringent lens for stereoscopic image display, comprising the liquid crystal composition according to any one of Items 1 to 18.

According to the present invention, while having a high upper limit temperature of the nematic phase and a low lower limit temperature of the nematic phase, a large dielectric anisotropy, a small dielectric loss tangent (tan δ), and a low driving voltage in the frequency range where electromagnetic wave control is performed. At least one of the properties of the composition can be satisfied, such as a large dielectric anisotropy at low frequencies for reduction. Furthermore, at least one of the properties of the composition, such as low viscosity, high resistivity in the driving frequency range, and stability against heat, can be further satisfied, making it possible to provide a more preferable liquid crystal composition. An element using the liquid crystal composition of the present invention can exhibit excellent characteristics of electromagnetic wave control over a wide temperature range.

Terms used in this specification are as follows. 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 an electromagnetic wave control panel and an electromagnetic wave control module. "Liquid crystal compound" means a compound having a liquid crystal phase such as a nematic phase or a smectic phase, or a compound having no liquid crystal phase, but it is used for the purpose of adjusting the temperature range, viscosity, dielectric anisotropy, etc. of the liquid crystal phase. It is a general term for compounds mixed in the composition. This compound has a six-membered ring such as 1,4-cyclohexylene or 1,4-phenylene, and its molecules (liquid crystal molecules) are rod-like. A "polymerizable compound" is a compound added for the purpose of forming a polymer in the composition. A liquid crystalline compound having alkenyl is not classified as a polymerizable compound in that sense.

A liquid crystal composition is prepared by mixing a plurality of liquid crystalline compounds. The ratio (content) of the liquid crystalline compound is represented by weight percentage (% by weight) based on the weight of the liquid crystal composition. This liquid crystal composition contains an optically active compound, an antioxidant, an ultraviolet absorber, a stabilizer against ultraviolet rays and heat, a quenching agent, a dye (dichroic dye), an antifoaming agent, a polymerizable compound, a polymerization initiator, and a polymerization inhibitor. Additives such as agents, antistatic agents, magnetic compounds are added as required. The proportion (addition amount) of the additive is represented by weight percentage (% by weight) based on the weight of the liquid crystal composition, like the proportion of the liquid crystalline compound. Parts per million (ppm) by weight are sometimes used. Proportions of polymerization initiators and polymerization inhibitors are exceptionally expressed based on the weight of the polymerizable compound.

"The upper limit temperature of the nematic phase" may be abbreviated as "the upper limit temperature". "Lower limit temperature of nematic phase" may be abbreviated as "lower limit temperature". The expression "increase the dielectric anisotropy" means that the value increases positively in the case of a composition with a positive dielectric anisotropy, and in a composition with a negative dielectric anisotropy. When it is a thing, it means that its value increases negatively.

At least one compound selected from the group of compounds represented by formula (1) may be 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. "At least one" with respect to "may be replaced" means that not only the position but also the number thereof may be selected without limitation.

上記の化合物（１ｚ）を例にして説明する。式（１ｚ）において、六角形で囲んだαおよびβの記号はそれぞれ環αおよび環βに対応し、六員環、縮合環のような環を表す。添え字‘ｘ’が２のとき、２つの環αが存在する。２つの環αが表す２つの基は、同一であってもよく、または異なってもよい。このルールは、添え字‘ｘ’が２より大きいとき、複数の環αに適用される。このルールは、結合基Ｚのような、他の記号にも適用される。環βの一辺を横切る斜線は、環β上の任意の水素が置換基（－Ｓｐ－Ｐ）で置き換えられてもよいことを表す。添え字‘ｙ’は置き換えられた置換基の数を示す。添え字‘ｙ’が０のとき、そのような置き換えはない。添え字‘ｙ’が２以上のとき、環β上には複数の置換基（－Ｓｐ－Ｐ）が存在する。この場合にも、「同一であってもよく、または異なってもよい」のルールが適用される。なお、このルールは、Ｒａの記号を複数の化合物に用いた場合にも適用される。

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

In formula (1z), for example, expressions such as "Ra and Rb are alkyl, alkoxy, or alkenyl" mean that Ra and Rb are independently selected from the group of alkyl, alkoxy, and alkenyl. means Here, the group represented by Ra and the group represented by Rb may be the same or different. This rule also applies when the Ra symbol is used for multiple compounds. This rule also applies when multiple Ra's are used in one compound.

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

The expression "at least one 'A'" means that the number of 'A' is arbitrary. The expression "at least one 'A' may be replaced with 'B'" means that when the number of 'A' is 1, the position of 'A' is arbitrary, and the number of 'A' is 2 When there are more than one, their positions can be chosen without restriction. The expression "at least one -CH ₂ - may be replaced with -O-" is sometimes used. In this case, -CH ₂ -CH ₂ -CH ₂ - may be converted to -O-CH ₂ -O- by replacing non-adjacent -CH ₂ - with -O-. However, adjacent -CH ₂ - is not replaced by -O-. This is because —O—O—CH ₂ — (peroxide) is produced by this replacement.

カルボニルオキシのような結合基も同様に、－ＣＯＯ－であってもよいし、－ＯＣＯ－であってもよい。 Alkyl in the liquid crystalline compound is straight-chain alkyl or branched-chain alkyl, and does not include cyclic alkyl unless otherwise specified. Straight chain alkyls are preferred over branched chain alkyls. The same applies to terminal groups such as alkoxy and alkenyl. The configuration of 1,4-cyclohexylene is preferably trans rather than cis in order to increase the maximum temperature. 2-Fluoro-1,4-phenylene means the following two divalent radicals. In the chemical formula, fluorine may be directed leftward (L) or rightward (R). This rule includes 2,5-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,3-dioxane- It also applies to asymmetric ring divalent radicals such as 2,5-diyl, tetrahydropyran-2,5-diyl. A preferred tetrahydropyran-2,5-diyl is rightward (R) in order to increase the maximum temperature.

A linking group such as carbonyloxy may similarly be -COO- or -OCO-.

In the chemical formulas of component compounds, the symbol for terminal group ^R12 is used for multiple compounds. In these compounds, any two groups represented by R ¹² may be the same or different. For example, there is a case where R ¹² of compound (1-1) is methyl and R ¹² of compound (1-2) is ethyl. In some cases, R ¹² of compound (1-1) is ethyl and R ¹² of compound (1-2) is propyl. This rule also applies to symbols such as R ¹¹ , R ¹³ , R ¹⁴ , R ² , R ³¹ , R ³² .

The present invention also includes the following items. (a) optically active compound, antioxidant, ultraviolet absorber, stabilizer against ultraviolet light and heat, quencher, dye (dichroic dye), antifoaming agent, polymerizable compound, polymerization initiator, polymerization inhibitor, charge The above composition further comprising at least one selected from additives such as inhibitors, magnetic compounds. (b) a device containing the above composition; (c) A device containing the above composition and used for controlling electromagnetic wave signals with a frequency anywhere from 1 GHz to 10 THz. (d) the above composition further containing a polymerizable compound, and a device containing this composition; (e) Use of the above composition as a composition having a nematic phase. (f) Use as an optically active composition by adding an optically active compound to the above composition.

The liquid crystal composition of the present invention has a large dielectric anisotropy and a small dielectric loss tangent (tan δ) in the frequency range of electromagnetic wave signals in the range of 1 GHz to 10 THz. Therefore, it can be suitably used as an element related to electromagnetic waves (microwaves) not only in the range of 1 GHz to 10 THz but also in the range of 1 GHz to 50 GHz.

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 compound and the main effect of this compound on the composition are described. Third, the combination of ingredients in the composition, the preferred proportions of the ingredients and the rationale for them are described. Fourth, preferred forms of component compounds are described. Fifth, preferred component compounds are shown. Sixth, additives that may be added to the composition are described. Seventh, the method for synthesizing the component compounds will be explained. Finally, the use of the composition will be explained.

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). "Another liquid crystalline compound" is a liquid crystalline compound different from compound (1). Such compounds are incorporated into the composition for the purpose of further adjusting its properties. Additives include optically active compounds, antioxidants, ultraviolet absorbers, stabilizers against ultraviolet rays and heat, quenchers, dyes (dichroic dyes), antifoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, Antistatic agents, polar compounds, and the like.

Composition B consists essentially of a liquid crystalline compound selected from compound (1). "Substantially" means that the composition may contain additives, but does not contain other liquid crystalline compounds. Composition B has fewer components than Composition A. Composition B is preferable to composition A from the viewpoint of cost reduction. The composition A is preferable to the composition B from the viewpoint that the properties can be further adjusted by mixing other liquid crystalline compounds.

Second, the main properties of the component compound and the main effect of this compound 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 medium, and S small or low. The symbols L, M, S are classifications based on qualitative comparisons between component compounds, with 0 (zero) meaning the value is approximately zero or close to zero.

Table 1 Properties of compounds

When the component compounds are mixed into the composition, the main effects of the component compounds on the properties of the composition are as follows.
Compound (1) mainly has the effect of increasing the refractive index anisotropy of the liquid crystal composition and widening the temperature range of the nematic phase. The upper limit temperature, lower limit temperature, and viscosity can be adjusted depending on the number of rings contained in compound (1). That is, when (a+b) is small, such as 1, the upper and lower temperature limits are lowered and the viscosity is lowered. Also, when (a+b) is large, such as 4, the upper limit temperature and lower limit temperature rise, and the viscosity rises.
The compound (2) mainly has the effect of increasing the refractive index anisotropy while increasing the dielectric anisotropy. In order to achieve high switching characteristics and high energy efficiency, a large dielectric anisotropy is preferable. The relationship between the number of rings contained in the compound (the number of c in the formula (2)), the upper limit temperature, the lower limit temperature and the viscosity has the same tendency as that of the compound (1).
Compound (3) has the effect of widening the temperature range of the nematic phase while mainly increasing the refractive index anisotropy. The relationship between the number of rings contained in the compound (the number of d in the formula (3)), the upper limit temperature, the lower limit temperature, and the viscosity has the same tendency as the compound (1) and the compound (2), but the compound (3) The effect of raising the upper limit temperature, lowering the lower limit temperature, and lowering the viscosity tends to be greater than those of compound (1) and compound (2).

Thirdly, the combination of ingredients in the composition, the preferred proportions of the ingredient compounds and the basis thereof will be explained. Preferred combinations of components in the composition are compound (1) + compound (2), compound (1) + compound (3), or compound (1) + compound (2) + compound (3). In addition, a composition consisting only of compound (1) is also preferred. A particularly preferred combination is compound (1)+compound (2)+compound (3) from the viewpoint of increasing refractive index anisotropy and dielectric anisotropy and decreasing viscosity.

Based on the weight of the liquid crystal composition, the preferred proportion of compound (1) ranges from about 5% to about 75% by weight in order to increase the temperature range of the nematic phase while increasing the refractive index anisotropy. . A more preferred proportion ranges from about 10% to about 60% by weight. A particularly preferred proportion ranges from about 20% to about 60% by weight.

Based on the weight of the liquid crystal composition, the preferred proportion of compound (2) is from about 10% by weight to about It is in the range of 70% by weight. A more preferred proportion ranges from about 10% to about 65% by weight. A particularly preferred proportion ranges from about 20% to about 50% by weight.

Based on the weight of the liquid crystal composition, a preferable proportion of compound (3) is about 5% by weight or more in order to increase the temperature range of the nematic phase while increasing the refractive index anisotropy. about 65% by weight or less for lowering. A more preferred proportion ranges from about 10% to about 60% by weight. A particularly preferred proportion ranges from about 20% to about 60% by weight.

Fourth, preferred forms of component compounds are described. R ¹¹ and R ² are hydrogen, halogen, or alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —S— and at least One -(CH ₂ ) ₂ - may be replaced by -CH=CH- or -C≡C- and in these groups at least one hydrogen may be replaced by halogen. Preferred R ¹¹ and R ² are alkoxy having 1 to 6 carbon atoms in order to increase refractive index anisotropy. R ³¹ and R ³² are hydrogen or alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —S— and at least one — (CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C— and in these groups at least one hydrogen may be replaced by halogen. Preferred R ³¹ and R ³² are alkyl having 1 to 6 carbon atoms for increasing stability against ultraviolet light or heat, and alkoxy having 1 to 6 carbon atoms for increasing refractive index anisotropy.

R ¹² is hydrogen, halogen, —C≡N, —N═C═S, —C≡C—C≡N, or alkyl having 1 to 12 carbon atoms, wherein at least one —CH ₂ — may be replaced by —O— or —S— and at least one —(CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C—, these groups , at least one hydrogen may be replaced with a halogen. Preferred R ¹² is -N=C=S or -C≡CC≡N to increase refractive index anisotropy.

When R ¹¹ , R ¹² , R ² , R ³¹ _, and R ³² are alkyl, preferred alkyls are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, or octyl. More preferred alkyls are ethyl, propyl, butyl, pentyl, or heptyl to reduce viscosity.

a and b are 0, 1, 2, 3, or 4, and the sum of a and b is 1 or more and 4 or less. Preferred values of a and b are 0 and 1 in order to lower the viscosity, and the sum of a and b is 4 in order to raise the maximum temperature and increase the refractive index anisotropy.

c is 0 or 1, d is 0, 1, 2, or 3, and the sum of c and d is 1 or more and 3 or less. Preferred c is 0 for increasing the refractive index anisotropy and lowering the viscosity, and 1 for lowering the minimum temperature. Desirable d is 1 for lowering the lower limit temperature and lowering the viscosity, and 2 or 3 for increasing the refractive index anisotropy and raising the upper limit temperature. A preferable sum of c and d is 2 or 3 in order to increase the refractive index anisotropy and increase the maximum temperature.

e is 0 or 1; Desirable e is 1 in order to increase the refractive index anisotropy and to increase the maximum temperature.

Z ¹¹ and Z ¹² are a single bond or alkylene having 1 to 4 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —COO— and at least one —(CH ₂ ) ₂ — may be replaced with —CH═CH—, —C≡C—, or —C≡CC≡C— in which at least one hydrogen is halogen; may be replaced. Preferred Z ¹¹ and Z ¹² are -CH=CH- or -C≡C- for increasing refractive index anisotropy.

Z ²¹ , Z ²² , Z ³¹ and Z ³² are a single bond, -C≡C-, or -C≡CC≡C-. Preferred Z ²¹ , Z ²² , Z ³¹ , and Z ³² are single bonds to reduce viscosity, and -C≡C- or -C≡CC≡C- to increase refractive index anisotropy. be.

Ring A ¹¹ and Ring A ¹² are 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 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 replaced with halogen or alkyl having 1 to 6 carbon atoms. Preferred ring A ¹¹ and ring A ¹² are 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by halogen, 1,4-phenylene in which at least one hydrogen is replaced by methyl, pyrimidine- 2,5-diyl, naphthalene-2,6-diyl, or pyridine-2,5-diyl. More preferred ring A ¹¹ and ring A ¹² are 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine, and 1,4-phenylene in which at least one hydrogen is replaced by methyl. be.

Preferred examples of 1,4-phenylene in which at least one hydrogen is replaced with halogen or alkyl having 1 to 6 carbon atoms are groups represented by formulas (A-1) to (A-22). In order to have excellent compatibility with other liquid crystalline compounds, formula (A-1), formula (A-2), formula (A-12), formula (A-15), or formula (A- 16) is more preferred.

Ring A ² is 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, 2 , 6,7-trioxabicyclo[2.2.2]octane-1,4-diyl, naphthalene-2,6-diyl or pyridine-2,5-diyl, and at least one hydrogen on these rings may be replaced by halogen or alkyl having 1 to 3 carbon atoms.
Preferred ring ^A2 is 1,4-cyclohexylene, pyrimidine-2,5-diyl, naphthalene-2,6-diyl or pyridine-2,5-diyl. More preferred is 1,4-cyclohexylene.

または

であり、これらの環上の少なくとも１つの水素はハロゲンで置き換えられてもよく、
Ｌ^１１は、炭素数１から３のアルキルであり、Ｌ^１２は、水素または炭素数１から３のアルキルである。
好ましいWは、相溶性を上げるため、

である。 Ring W is

or

and at least one hydrogen on these rings may be replaced by a halogen,
L ¹¹ is alkyl having 1 to 3 carbon atoms, and L ¹² is hydrogen or alkyl having 1 to 3 carbon atoms.
Preferred W is, in order to increase the compatibility,

is.

L ²¹ , L ²² , L ²³ , and L ²⁴ are hydrogen, halogen, alkyl having 1 to 3 carbon atoms, or cycloalkyl having 3 to 5 carbon atoms. Preferred L ²¹ , L ²² , L ²³ and L ²⁴ are hydrogen for increasing the maximum temperature, fluorine or chlorine for increasing the dielectric anisotropy, and fluorine, chlorine, methyl for decreasing the minimum temperature. , ethyl, or cyclopropyl. In order to increase the dielectric anisotropy of the entire liquid crystal composition, it is preferable that both ^L21 and ^L22 are not halogen.

^L31 , ^L32 , ^L33 , ^L34 , ^L35 , ^L36 , and ^L37 are hydrogen, halogen, methyl, ethyl, or cyclopropyl. Preferred L ³¹ , L ³² , L ³³ , L ³⁴ , L ³⁵ , L ³⁶ , and L ³⁷ are halogen, ethyl, or cyclopropyl to improve compatibility. Since the dielectric anisotropy becomes negative and reduces the dielectric anisotropy of the entire liquid crystal composition, it is preferable that L ³² and L ³³ or L ³⁵ and L ³⁶ are not halogen at the same time.

Y ²¹ and Y ²² are hydrogen, halogen, or alkyl having 1 to 3 carbon atoms. Preferred Y ²¹ and Y ²² are hydrogen for increasing the refractive index anisotropy, fluorine or chlorine for increasing the dielectric anisotropy, and methyl or ethyl for decreasing the minimum temperature.

^X2 is halogen, -C≡N, -C≡CC≡N, or -N=C=S. Preferred ^X2 is -C≡CC≡N or -N=C=S in order to increase the refractive index anisotropy.

Fifth, preferred component compounds are shown.
Preferred compound (1) is compound (1-1) and/or compound (1-2).

R ¹¹ , R ¹² , L ¹¹ , L ¹² , ring A ¹² , Z ¹² and b in formulas (1-1) and (1-2) are as described above.

Preferred compounds in compound (1-1) are compound (1-1a) to compound (1-1d), and at least one compound (1) is compound (1-1a) or compound (1-1b) is preferred, and compound (1-1b) is most preferred.
Compounds (1-2) are preferably compounds (1-2a) to (1-2e), and at least one compound (1) is preferably compound (1-2a).

In formulas (1-1a) to (1-1d) and formulas (1-2a) to (1-2e), ring A ¹² , R ¹¹ and R ¹² are as described above.

Preferred compounds (2) are compounds (2-1) to (2-8).

In compounds (2-1) to (2-8), R ^2′ is alkyl having 1 to 12 carbon atoms, and in this alkyl, at least one —(CH ₂ ) ₂ — is —CH═CH— or may be replaced by -C≡C-;
L ^21′ , L ^22′ , L ^23′ and L ^24′ are hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl;
Y ^21' and Y ^22' are hydrogen, fluorine, chlorine, methyl, or ethyl.
X ^2' is -C≡CC≡N or -N=C=S.

At least one compound (2) is preferably compound (2-1), compound (2-3), compound (2-4), or compound (2-5).

Preferred compounds (3) are compounds (3-1) to (3-5).

In compounds (3-1) to (3-5), R ^31′ and R ^32′ are alkyl having 1 to 12 carbon atoms, and in this alkyl, at least one —CH ₂ — is —O— optionally, at least one -(CH ₂ ) ₂ - is optionally replaced by -CH=CH- or -C≡C-, L ^31′ , L ^32′ , L ^33′ , L ^{34 '} , L ^35' , L ^36' and L ^37' are hydrogen, fluorine, chlorine, methyl, or ethyl.

At least one compound (3) is preferably compound (3-3), compound (3-4), or compound (3-5). at least two of the compounds (3) are compound (3-3) and compound (3-5), compound (3-3) and compound (3-4), or compound (3-4) and compound (3-5) ) is more preferred.

Sixth, additives that may be added to the composition are described. Such additives include optically active compounds, antioxidants, ultraviolet absorbers, stabilizers against ultraviolet rays and heat, quenchers, dyes (dichroic dyes), antifoaming agents, polymerizable compounds, polymerization initiators, polymerization These include inhibitors, antistatic agents, and polar compounds. Hereinafter, the mixing ratio of these additives is the ratio (weight) based on the weight of the liquid crystal composition unless otherwise specified.

Any combination of additives may be used, and for example, it is possible to use a combination of different types of antioxidants. It is also possible to use a combination of different types of additives, for example, a combination of antioxidants, UV absorbers, and stabilizers.

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 compounds are compounds (4-1) to (4-5). A preferred proportion of the optically active compound is about 5% by weight or less. A more preferred proportion ranges from about 0.01% to about 2% by weight.

In order to prevent a decrease in resistivity due to heating in the atmosphere, or to maintain a large voltage holding ratio not only at room temperature but also at temperatures close to the upper limit after long-term use of the device, an antioxidant is added. added to things. Preferred examples of antioxidants include compounds (5) where t is an integer from 1 to 9.

In compound (5), preferred t is 1, 3, 5, 7, or 9. More preferable t is 7. Compound (5) in which t is 7 has low volatility, and is effective in maintaining 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 the device. A preferable 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 percentage is in the range of about 100 ppm to about 300 ppm.

Preferred examples of UV absorbers are benzophenone derivatives, benzoate derivatives, triazole derivatives and the like. Light stabilizers such as sterically hindered amines are also preferred. Preferred examples of light stabilizers include compounds (6-1) to (6-16). A preferable ratio of these absorbents and stabilizers is about 50 ppm or more to obtain the effect, and about 10000 ppm or less so as not to lower the upper limit temperature or raise the lower limit temperature. More preferred proportions range from about 100 ppm to about 10,000 ppm.

Additives preferred as stabilizers against ultraviolet light and heat include amino-tolan compounds represented by compound (7) (US Pat. No. 6,495,066).

In formula (7), R ^m and R ⁿ are alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, alkenyl having 2 to 12 carbon atoms, or alkenyloxy having 2 to 12 carbon atoms; ^a is —NO ₂ , —C≡N, —N═C═S, fluorine, or —OCF ₃ ; Y ^a and Y ^b are hydrogen or fluorine. Preferred proportions of these stabilizers range from 1 to 20% by weight, preferably from 5 to 10% by weight, in order to obtain their effect.

A quenching agent is a compound that receives light energy absorbed by a liquid crystalline compound and converts it into heat energy, thereby preventing decomposition of the liquid crystalline compound. A preferable proportion of these quenchers is about 50 ppm or more to obtain the effect, and about 20000 ppm or less to lower the minimum temperature. More preferred proportions range from about 100 ppm to about 10,000 ppm.

Dichroic dyes such as azo dyes, anthraquinone dyes, etc. are added to the composition in order to adapt to GH (guest host) mode devices. Preferred proportions of pigment range from about 0.01% to about 10% by weight. Antifoaming agents such as dimethylsilicone oil, methylphenylsilicone oil, etc. are added to the composition to prevent foaming. A preferable proportion of the antifoaming agent is about 1 ppm or more to obtain its effect, and about 1000 ppm or less to prevent display defects. More preferred percentages range from about 1 ppm to about 500 ppm.

A polymerizable compound is added to the composition to make it compatible with the polymer-stabilized device. Preferred examples of polymerizable compounds are compounds having polymerizable groups such as acrylates, methacrylates, vinyl compounds, vinyloxy compounds, propenyl ethers, epoxy compounds (oxiranes, oxetanes), vinyl ketones. Further preferred examples are derivatives of acrylates or methacrylates. A preferable 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 driving temperature. A more preferred percentage ranges from about 0.1% to about 10% by weight. The polymerizable compound is polymerized by UV irradiation. Polymerization may be carried out in the presence of a polymerization initiator such as a photoinitiator. Suitable conditions for polymerization, suitable types of initiators, and suitable amounts are known to those skilled in the art and described in the literature. For example, the photoinitiators Irgacure 651 (registered trademark; BASF), Irgacure 184 (registered trademark; BASF) or Darocure 1173 (registered trademark; BASF) are suitable for radical polymerization. A preferred proportion of photoinitiator ranges 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 preferred proportion is in the range of about 1 part to about 3 parts by weight.

A polymerization inhibitor may be added to prevent polymerization during storage of the polymerizable compound. The polymerizable compound is usually added to the composition without removing the polymerization inhibitor. Examples of polymerization inhibitors are hydroquinone, hydroquinone derivatives such as methylhydroquinone, 4-tert-butylcatechol, 4-methoxyphenol, phenothiazine and the like.

A polar compound, as used herein, is an organic compound having polarity and does not include compounds having ionic bonds. 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 the uneven distribution of partial charges between different atoms in a compound. For example, a polar compound has at least one substructure such as —OH, —COOH, —SH, —NH ₂ , >NH, >N—.

Seventh, the method for synthesizing the component compounds will be described. These compounds are available from Organic Syntheses, John Wiley & Sons, Inc., Organic Reactions, John Wiley & Sons, Inc., Comprehensive Organic Synthesis, Pergamon Press), It can be synthesized by the method described in books such as Shin Jikken Kagaku Koza (Maruzen). Compositions are prepared from the compounds thus obtained by known methods. For example, the component compounds are mixed and dissolved together by heating.

Finally, the use of the composition will be explained. Since the composition of the present invention has a lower limit temperature of about −10° C. or lower and an upper limit temperature 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 compound by adding an optically active compound. Use as an active composition is possible.

Oriented liquid crystal compositions have different dielectric constants in the vertical and horizontal directions. Therefore, it has dielectric anisotropy as a characteristic.

Not limited to antenna elements, elements that use a liquid crystal composition generally consist of an element in which two substrates sandwich a liquid crystal composition as a layer. liquid crystal molecules are aligned (orientated). When there is no external field, the liquid crystal molecules in the element are aligned in one direction due to the alignment control force of the alignment film. will turn in the direction of When the external field is removed again, the alignment control force of the alignment film restores the original alignment in one direction. In this manner, the orientation of the liquid crystal molecules in the element can be controlled by the orientation and magnitude of the external field, thereby controlling the inclination (angle) of the liquid crystal molecules in the element with respect to one direction. Since the liquid crystal composition has dielectric anisotropy, it is possible to control the dielectric constant of the liquid crystal composition layer in the device in one direction by controlling the angle of the liquid crystal molecules in the device in one direction. can. For example, the dielectric constant of a layer of liquid crystal composition in a device in one direction in the absence of an external field is the dielectric constant in the vertical direction of the liquid crystal composition, and by applying an external field perpendicular to the one direction, it is Even the dielectric constant in the horizontal direction of the liquid crystal composition can be changed.

Thus, the liquid crystal composition of the present invention can be used as a switching element capable of reversibly controlling the dielectric constant by reversibly changing the alignment direction of the liquid crystal molecules.

Controlling the angles of the liquid crystal molecules in the device can be done using an electric field as the external field. The voltage required to drive the liquid crystal molecules is the drive voltage. In order to control the angles of the liquid crystal molecules, it is required that the dielectric anisotropy of the liquid crystal composition at 25° C. is at least greater than 2 in the frequency range of less than 1 MHz. In order to further reduce the driving voltage, it is necessary to increase the dielectric anisotropy at 25° C. in the frequency range of less than 1 MHz, preferably 5 or more, more preferably 10 or more.

As described, the larger the refractive index anisotropy (Δn) in visible light (for example, a wavelength of 589 nm), the higher the dielectric anisotropy (Δε) in the high-frequency region (range from microwave to terahertz wave (approximately 10 THz)). get bigger. The liquid crystal composition containing the compound represented by formula (1) of the present invention preferably has a refractive index anisotropy (Δn) at 25° C. of 0.25 or more. In particular, when used for high-frequency applications, Δn is preferably 0.35 or more, more preferably 0.45 or more.

In order to control the phase difference in the high frequency region, the dielectric anisotropy in the high frequency region is preferably 0.5 or more. In order to perform more suitable phase control, it is necessary to increase the dielectric anisotropy in the high frequency region. In order to perform sufficient phase control, the dielectric anisotropy is preferably 1.0 or more, more preferably 1.2 or more.

Further, the composition of the present invention can be used for elements used for controlling electromagnetic waves with frequencies in the range of 1 GHz to 10 THz. Examples of applications include millimeter wave band variable phase shifters, LiDAR (Light Detection and Ranging) elements, and antennas to which metamaterial technology is applied.

Articles containing this composition can be used for applications other than electromagnetic wave control. By reversibly changing the alignment direction of the liquid crystal molecules, it is possible to control not only the dielectric anisotropy but also the refractive index anisotropy. Liquid crystal lenses, birefringent lenses for stereoscopic image display, and the like are examples of applications for controlling these characteristics.

The present invention will be described in more detail by way of examples. The invention is not limited by these examples. The invention also includes mixtures of at least two of the compositions of the Examples. The properties of the compositions were measured by the methods described below.

Measurement method: Properties were measured by the following methods. Many of these are the methods described in the JEITA standard (JEITA ED-2521B) deliberated and enacted by the Japan Electronics and Information Technology Industries Association (hereinafter referred to as JEITA), or modified methods thereof was the method. A thin film transistor (TFT) was not attached to the TN device used for the measurement.

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

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

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 having a polarizing plate attached to an eyepiece. After rubbing the surface of the main prism in one direction, the sample was dropped onto the main prism. The refractive index _n∥ was measured when the direction of polarization was parallel to the rubbing direction. The refractive index _n⊥ was measured when the polarization direction was perpendicular to the rubbing direction. The value of refractive index anisotropy was calculated from the formula Δn= _n∥ − _n⊥ .

Refractive index anisotropy (for Δn≧0.30; measured at 25° C.):
A sample was placed in a device composed of two glass substrates and oriented antiparallel. The thickness direction retardation (Rth) of this element was measured using a retardation film/optical material inspection device (manufactured by Otsuka Electronics Co., Ltd., trade name: RETS-100), and the retardation value (Rth) and the distance between the glass substrates were measured. The refractive index anisotropy (Δn) was calculated from (d: cell gap) by the following formula. The wavelength of light used is 589 nm.
Rth=Δn·d

Dielectric anisotropy (Δε; measured at 25°C):
A sample was placed in a TN device in which the distance (cell gap) between the two glass substrates was 9 μm and the twist angle was 80 degrees. A sine wave (10 V, 1 kHz) was applied to this device, and after 2 seconds the permittivity ( _ε∥ ) in the longitudinal direction of the liquid crystal molecules was measured. A sine wave (0.5 V, 1 kHz) was applied to this device, and after 2 seconds the permittivity (ε _⊥ ) in the minor axis direction of the liquid crystal molecules was measured. The value of the dielectric anisotropy was calculated from the formula Δε= _ε∥ − _ε⊥ .

Dielectric anisotropy at 28 GHz (measured at room temperature):
Dielectric anisotropy at 28 GHz (Δε@28 GHz) is reported in Applied Optics, Vol. 44, No. 7, p. 1150 (2005), a variable short-circuit waveguide fitted with a window material was filled with liquid crystal and held in a static magnetic field of 0.3 T for 3 minutes. A microwave of 28 GHz was input to the waveguide, and the amplitude ratio of the reflected wave to the incident wave was measured. Refractive indices (n: ne, no) and loss parameters (α: αe, αo) were determined by changing the direction of the static magnetic field and the tube length of the shunt.
For the calculation of the complex permittivity (ε′, ε″), the calculated refractive index, loss parameter and the following relational expression were used.
ε′=n ² −κ ²
ε″=2nκ
α=2ωκ/c
where c is the speed of light in vacuum, ω is the angular velocity, and κ is the extinction coefficient. _ε'∥ was calculated from _ne , _ε'⊥ was calculated from _no , and the dielectric anisotropy (Δε@28 GHz) was calculated from _ε'∥ - _ε'⊥ .

Dielectric loss tangent (tan δ; measured at room temperature) at 28 GHz:
The dielectric loss tangent (tan δ@28 GHz) at 28 GHz was calculated from ε″/ε′ using complex permittivity (ε′, ε″). Since anisotropy also appears in tan δ, the larger value is indicated.

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

[Comparative Example 1] Liquid crystal composition C1
5-B(F) TB(F)-TC (2-1) 15%
5-BTB (F) TB-2 (3-3) 9%
5-BTB (F) TB-3 (3-3) 9%
2-BTB-O1 (3-4) 5%
3-BTB-O1 (3-4) 5%
4-BTB-O1 (3-4) 5%
4-BTB-O2 (3-4) 4%
5-BTB-O1 (3-4) 4%
3-BTTB-O1 (3-5) 15%
5-BTTB-O1 (3-5) 15%
3-BB(F,F)XB(F)B(F,F)-F (-) 5%
3-GB(F)B(F)B(F)-F (-) 5%
3-GBB(F)B(F,F)-F(-) 2%
4-GBB(F)B(F,F)-F(-) 2%
NI=127.2° C.; Δn=0.40; Δε=10.5
The dielectric anisotropy and tan δ of the liquid crystal composition C1 at 28 GHz were as follows.
Δε @ 28 GHz = 0.93
tan δ @ 28 GHz = 0.014

[Comparative Example 2] Liquid crystal composition C2
5-B(F) TB(F)-TC (2-1) 15%
5-BTB (F) TB-2 (3-3) 10%
5-BTB (F) TB-3 (3-3) 10%
5-BTB (F) TB-4 (3-3) 5%
2-BTB-O1 (3-4) 4%
3-BTB-O1 (3-4) 3%
4-BTB-O1 (3-4) 3%
4-BTB-O2 (3-4) 3%
5-BTB-O1 (3-4) 3%
3-BTTB-O1 (3-5) 16%
5-BTTB-O1 (3-5) 16%
3-BB(F,F)XB(F)B(F,F)-F (-) 12%
NI=127.0° C.; Δn=0.41; Δε=10.3
The dielectric anisotropy and tan δ of the liquid crystal composition C2 at 28 GHz were as follows.
Δε @ 28 GHz = 0.97
tan δ @ 28 GHz = 0.014

[Comparative Example 3] Liquid crystal composition C3
5-B(F) TB(F)-TC (2-1) 15%
5-B(Me)TB(F)-TC (2-1) 15%
5-BTB (F) TB-2 (3-3) 10%
5-BTB (F) TB-3 (3-3) 10%
3-BTTB-O1 (3-5) 15%
5-BTTB-O1 (3-5) 15%
2O-btTB-3 (-) 20%
NI=128.3° C.; Δn=0.44; Δε=12.3
The dielectric anisotropy and tan δ of the liquid crystal composition C3 at 28 GHz were as follows.
Δε @ 28 GHz = 1.04
tan δ @ 28 GHz = 0.014

[Comparative Example 4] Liquid crystal composition C4
5-B(F) TB(F)-TC (2-1) 15%
3-BTB(F,F)-NCS (2-1) 10%
3-BTB(F)-NCS (2-1) 5%
3-BTTB-O1 (3-5) 15%
5-BTTB-O1 (3-5) 15%
5-BTB (F) TB-2 (3-3) 10%
5-BTB (F) TB-3 (3-3) 10%
2O-btTB-3 (-) 20%
NI=121.5° C.; Δn=0.43; Δε=9.7
The dielectric anisotropy and tan δ of the liquid crystal composition C4 at 28 GHz were as follows.
Δε @ 28 GHz = 1.06
tan δ @ 28 GHz = 0.014

[Comparative Example 5] Liquid crystal composition C5
5-B(F) TB(F)-TC (2-1) 15%
5-B(F)TB(Me)-TC (2-1) 10%
3-BB(F)TB(F)-TC (2-3) 5%
5-BTB (F) TB-2 (3-3) 9%
5-BTB (F) TB-3 (3-3) 9%
3-BTTB-O1 (3-5) 15%
5-BTTB-O1 (3-5) 15%
2O-btTB-3 (-) 22%
NI=135.9° C.; Δn=0.46; Δε=10.8
The dielectric anisotropy and tan δ of the liquid crystal composition C4 at 28 GHz were as follows.
Δε @ 28 GHz = 1.04
tan δ @ 28 GHz = 0.014

[Example 1] Liquid crystal composition M1
1O-bt(Me)TBB-3 (1-1b) 20%
5-B(F) TB(F)-TC (2-1) 15%
5-BB(F)TB-TC (2-3) 5%
2-BTB-O1 (3-4) 2%
3-BTB-O1 (3-4) 2%
4-BTB-O1 (3-4) 2%
4-BTB-O2 (3-4) 2%
5-BTB-O1 (3-4) 2%
3-BTTB-O1 (3-5) 15%
5-BTTB-O1 (3-5) 15%
2O-btTB-3 (-) 20%
NI=148.8° C.; Δn=0.47; Δε=6.8
The dielectric anisotropy and tan δ of the liquid crystal composition M1 at 28 GHz were as follows.
Δε @ 28 GHz = 1.08
tan δ @ 28 GHz = 0.012

[Example 2] Liquid crystal composition M2
1O-bt(Me)TBB-3 (1-1b) 20%
5-B(F) TB(F)-TC (2-1) 15%
5-BB(F)TB-TC (2-3) 5%
5-BTB (F) TB-2 (3-3) 10%
5-BTB (F) TB-3 (3-3) 10%
2-BTB-O1 (3-4) 2%
3-BTB-O1 (3-4) 2%
4-BTB-O1 (3-4) 2%
4-BTB-O2 (3-4) 2%
5-BTB-O1 (3-4) 2%
3-BTTB-O1 (3-5) 5%
5-BTTB-O1 (3-5) 5%
2O-btTB-3 (-) 20%
NI=162.5° C.; Δn=0.47; Δε=7.2
The dielectric anisotropy and tan δ of the liquid crystal composition M2 at 28 GHz were as follows.
Δε @ 28 GHz = 1.08
tan δ @ 28 GHz = 0.013

[Example 3] Liquid crystal composition M3
1O-bt(Me)TB-3 (1-1a) 10%
1O-bt(Me)TB-2 (1-1a) 10%
1O-bt(Me)TBB-3 (1-1b) 10%
5-B(F) TB(F)-TC (2-1) 15%
3-BB(F)TB-TC (2-3) 7%
5-BB(F)TB-TC (2-3) 8%
5-BTB (F) TB-2 (3-3) 10%
3-BTTB-O1 (3-5) 15%
5-BTTB-O1 (3-5) 15%
NI=166.7° C.; Δn=0.48; Δε=8.3
The dielectric anisotropy and tan δ of the liquid crystal composition M3 at 28 GHz were as follows.
Δε @ 28 GHz = 1.10
tan δ @ 28 GHz = 0.013

[Example 4] Liquid crystal composition M4
1O-bt(Me)TBB-3 (1-1b) 15%
5-B(F) TB(F)-TC (2-1) 15%
3-BB(F)TB(F)-TC (2-3) 15%
5-BTB (F) TB-2 (3-3) 15%
5-BTB (F) TB-3 (3-3) 10%
3-BTTB(2Me)-01 (3-5) 10%
3-BTTB-O1 (3-5) 10%
5-BTTB-O1 (3-5) 10%
NI=178.8° C.; Δn=0.49; Δε=10.5
The dielectric anisotropy and tan δ of the liquid crystal composition M4 at 28 GHz were as follows.
Δε @ 28 GHz = 1.15
tan δ @ 28 GHz = 0.013

[Example 5] Liquid crystal composition M5
1O-bt(Me)TBB-3 (1-1b) 10%
5-B(F) TB(F)-TC (2-1) 15%
3-BTB(F)-NCS (2-1) 10%
3-BB(F)TB(F)-TC (2-3) 15%
5-BTB (F) TB-2 (3-3) 10%
5-BTB (F) TB-3 (3-3) 10%
3-BTTB-O1 (3-5) 15%
5-BTTB-O1 (3-5) 15%
NI=167.5° C.; Δn=0.49; Δε=14.3
The dielectric anisotropy and tan δ of the liquid crystal composition M5 at 28 GHz were as follows.
Δε @ 28 GHz = 1.16
tan δ @ 28 GHz = 0.013

[Example 6] Liquid crystal composition M6
1O-bt(Me)TBB-3 (1-1b) 10%
5-B(F) TB(F)-TC (2-1) 10%
5-B(F)TB(Me)-TC (2-1) 10%
3-BB(F)TB(F)-TC (2-3) 15%
5-BTB (F) TB-2 (3-3) 10%
3-BTTB-O1 (3-5) 13%
5-BTTB-O1 (3-5) 12%
2O-btTB-3 (-) 20%
NI=161.7° C.; Δn=0.48; Δε=9.1
The dielectric anisotropy and tan δ of the liquid crystal composition M7 at 28 GHz were as follows.
Δε @ 28 GHz = 1.10
tan δ @ 28 GHz = 0.013

[Example 7] Liquid crystal composition M7
1O-bt(Me)TB-2 (1-1a) 5%
1O-bt(Me)TB-3 (1-1a) 15%
1O-bt(Me)TB-NCS (1-1a) 5%
1O-bt(Me)TBB-3 (1-1b) 5%
1O-bt(Me)TB(2F)B-5 (1-1b) 10%
5-B(F) TB(F)-TC (2-1) 10%
5-BTB(F)-TC(2-1) 15%
3-BB(F)TB-TC (2-3) 7%
3-BB(F)TB-TC (2-3) 8%
3-BTTB-O1 (3-5) 10%
5-BTTB-O1 (3-5) 10%
NI=165.6° C.; Δn=0.49; Δε=13.8
The dielectric anisotropy and tan δ of the liquid crystal composition M7 at 28 GHz were as follows.
Δε @ 28 GHz = 1.10
tan δ @ 28 GHz = 0.011

[Example 8] Liquid crystal composition M8
1O-BT(Me)TB-3 (1-2a) 10%
1O-bt(Me)TB-2 (1-1a) 10%
1O-bt(Me)TBH-3 (1-1b) 15%
1O-bt(Me)TBB-5 (1-1b) 15%
1O-bt(Me)TBB-3 (1-1b) 10%
1O-bt(Me)B(F)TB-5 (1-1c) 15%
5-B(F) TB(F)-TC (2-1) 15%
3-BB(F)TB(F)-TC (2-3) 10%
NI=209.0° C.; Δn=0.47; Δε=7.1

[Example 9] Liquid crystal composition M9
1O-bt(Me)TB-3 (1-1a) 10%
1O-bt(Me)TB-2 (1-1a) 10%
1O-bt(Me)TBH-3 (1-1b) 15%
1O-bt(Me)TBB-5 (1-1b) 15%
1O-bt(Me)TBB-4 (1-1b) 10%
1O-bt(Me)TBB-3 (1-1b) 10%
1O-bt(Me)TB(2F)B-5 (1-1b) 15%
1O-bt(Me)B(F)TB-5 (1-1c) 15%
NI=238.0° C.; Δn=0.47; Δε=0.1

[Example 10] Liquid crystal composition M10
1O-bt(Me)TB-3 (1-1a) 10%
1O-bt(Me)TB-2 (1-1a) 10%
1O-bt(Me)TB-NCS (1-1a) 5%
1O-bt(Me)TBB-3 (1-1b) 10%
1O-bt(Me)TB(2F)B-5 (1-1b) 10%
1-BtTB(2Me)-5(1-2a) 5%
1-BtTB-5 (1-2a) 10%
5-B(F) TB(F)-TC (2-1) 10%
5-BTB(F)-TC(2-1) 10%
5-BB(F)TB-TC (2-3) 10%
3-BTTB-O1 (3-5) 10%
NI=151.4° C.; Δn=0.47; Δε=11.1

A composition containing the compound (1-1d) and a composition containing the compounds (1-2b) to (1-2e) can also be obtained in the same manner as in Examples, taking into consideration the required properties of the composition. can. A composition in which any of the compounds (1-1a) to (1-1d) and the compounds (1-2a) to (1-2e) are used simultaneously can also be obtained in the same manner.

The refractive index anisotropy (Δn) of the compositions of Comparative Examples 1 to 5 ranged from 0.40 to 0.46, while the Δn of the compositions of Examples 1 to 10 ranged from 0.47 to was 0.49. The greater the Δn in visible light caused by electronic polarization, the greater the dielectric anisotropy (Δε) in the high frequency region. Since the example using the composition containing compound (1) has a larger Δn than the comparative example not containing compound (1), the dielectric anisotropy at 28 GHz (Δε @ 28 GHz will be a larger value is expected.

In fact, the Δε @ 28 GHz of the compositions of Comparative Examples 1 to 5 were 0.93 to 1.06, and the tan δ @ 28 GHz was 0.014. On the other hand, the compositions of Examples 1 to 8 had a Δε @ 28 GHz of 1.08 to 1.16 and a tan δ @ 28 GHz of 0.011 to 0.013.

The compositions of Examples 1 through 10 each contain compound (1). The dielectric anisotropy at high frequencies increases as the amount of such compounds contained in the composition increases. On the other hand, the value of tan δ@28 GHz becomes smaller.
The liquid crystal composition containing the compound (1) maintained the basic performance as a liquid crystal composition, and kept the value of tan δ @ 28 GHz small by increasing the refractive index anisotropy at 589 nm. Δε@28 GHz could be made relatively large.

The values of tan δ@28 GHz in Examples 1 to 7 were smaller than those in Comparative Examples 1 to 5, respectively.

The characteristics required for the liquid crystal composition are a large dielectric anisotropy that enables large phase control in the frequency range used for phase control, and a dielectric loss tangent that is proportional to the absorption energy of the electromagnetic wave signal of the liquid crystal composition. (tan δ) is required to be small. A comparison of the examples of the present application and the comparative examples proves that the composition of the present application has a large dielectric anisotropy (Δε@28 GHz) and a small tan δ@28 GHz. In general, the smaller the tan δ, the lower the absorption energy of electromagnetic waves. Therefore, the liquid crystal composition using the compound represented by formula (1) can reduce the absorption energy of electromagnetic wave signals and can set the loss of electromagnetic wave signals to be smaller. As a result, electromagnetic wave signals can be transmitted more efficiently.

The liquid crystal composition of the present invention has a high upper limit temperature of the nematic phase, a low lower limit temperature of the nematic phase, a low viscosity, a large refractive index anisotropy in the frequency region for controlling the electromagnetic wave signal, a large dielectric anisotropy, a small It satisfies at least one of the characteristics such as dielectric loss tangent (tan δ), large dielectric anisotropy at low frequencies for driving voltage reduction, or has an appropriate balance with respect to at least two characteristics. Devices containing this composition can be used to control electromagnetic signals in the frequency range of 1 GHz to 10 THz.

Claims (21)

A liquid crystal composition containing at least one compound selected from the group of compounds represented by formula (1).

In formula (1),
R ¹¹ is hydrogen, halogen, or alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —S—, and at least one — (CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C— and in these groups at least one hydrogen may be replaced by halogen;
R ¹² is hydrogen, halogen, —C≡N, —N═C═S, —C≡C—C≡N, or alkyl having 1 to 12 carbon atoms, wherein at least one —CH ₂ — may be replaced by —O— or —S— and at least one —(CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C—, these groups at least one hydrogen may be replaced with a halogen;
Ring W is

or

and at least one hydrogen on these rings may be replaced by halogen;
L ¹¹ is alkyl having 1 to 3 carbon atoms, and L ¹² is hydrogen or alkyl having 1 to 3 carbon atoms;
Ring A ¹¹ and Ring A ¹² are 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 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 replaced by halogen or alkyl having 1 to 6 carbon atoms;
Z ¹¹ and Z ¹² are a single bond or alkylene having 1 to 4 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —COO— and at least one —(CH ₂ ) ₂ — may be replaced with —CH═CH—, —C≡C—, or —C≡CC≡C— in which at least one hydrogen is halogen; may be replaced;
a and b are 0, 1, 2, 3, or 4, and the sum of a and b is 1 or more and 4 or less. 2. The liquid crystal composition according to claim 1, containing at least one compound selected from the group of compounds represented by formulas (1-1) and (1-2).

In formulas (1-1) and (1-2),
R ¹¹ is hydrogen, halogen, or alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —S—, and at least one — (CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C— and in these groups at least one hydrogen may be replaced by halogen;
R ¹² is hydrogen, halogen, —C≡N, —N═C═S, —C≡C—C≡N, or alkyl having 1 to 12 carbon atoms, wherein at least one —CH ₂ — may be replaced by —O— or —S— and at least one —(CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C—, these groups at least one hydrogen may be replaced by a halogen;
L ¹¹ is alkyl having 1 to 3 carbon atoms, and L ¹² is hydrogen or alkyl having 1 to 3 carbon atoms;
Ring A ¹² is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 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 these at least one hydrogen on the ring may be replaced by halogen or alkyl having 1 to 6 carbon atoms;
Z ¹² is a single bond or alkylene having 1 to 4 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —COO—, and at least one —(CH ₂ ) _2- may be replaced by -CH=CH-, -C≡C-, or -C≡C-C≡C- in which at least one hydrogen is replaced by halogen; well;
b is 1, 2, 3, or 4; 3. The liquid crystal composition according to claim 1, wherein the proportion of the compound represented by formula (1) is in the range of 5% by weight to 75% by weight based on the weight of the liquid crystal composition. 2. The liquid crystal composition according to claim 1, containing at least one compound selected from the group of compounds represented by formula (2).

In formula (2),
R ² is hydrogen, halogen, or alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —S—, and at least one — (CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C— and in these groups at least one hydrogen may be replaced by halogen;
Ring A ² is 1,4-cyclohexylene, 1,4-cyclohexenylene, tetrahydropyran-2,5-diyl, 1,3-dioxane-2,5-diyl, pyrimidine-2,5-diyl, 2 , 6,7-trioxabicyclo[2.2.2]octane-1,4-diyl, naphthalene-2,6-diyl or pyridine-2,5-diyl, and at least one hydrogen on these rings may be replaced by halogen or alkyl of 1 to 3 carbon atoms;
Z ²¹ and Z ²² are a single bond, —C≡C—, or —C≡C—C≡C—;
L ²¹ , L ²² , L ²³ , and L ²⁴ are hydrogen, halogen, alkyl having 1 to 3 carbon atoms, or cycloalkyl having 3 to 5 carbon atoms;
X ² is halogen, -C≡N, -C≡C-C≡N, or -N=C=S;
Y ²¹ and Y ²² are hydrogen, halogen, or alkyl having 1 to 3 carbon atoms;
c is 0 or 1, d is 0, 1, 2, or 3, and the sum of c and d is 1 or more and 3 or less. 5. The liquid crystal composition according to claim 4, containing at least one compound selected from the group of compounds represented by formulas (2-1) to (2-8).

In formulas (2-1) to (2-8),
R ^2′ is alkyl having 1 to 12 carbon atoms, in which at least one —(CH ₂ ) ₂ — may be replaced with —CH═CH— or —C≡C—;
L ^21′ , L ^22′ , L ^23′ and L ^24′ are hydrogen, fluorine, chlorine, methyl, ethyl, or cyclopropyl;
Y ^21' and Y ^22' are hydrogen, fluorine, chlorine, methyl, or ethyl.
X ^2' is -C≡CC≡N or -N=C=S. In the compound represented by formula (2),
5. The liquid crystal composition according to claim 4, comprising a compound selected from the group of compounds wherein ^X2 is -C≡CC≡N. In the compound represented by formula (2),
5. A liquid crystal composition according to claim 4, comprising a compound selected from the group of compounds wherein ^X2 is -N=C=S. In the compound represented by formula (2),
5. The method according to claim 4, comprising simultaneously a compound selected from the group of compounds in which X ² is -C≡C—C≡N and a compound selected from the group of compounds in which X ² is -N=C=S. The described liquid crystal composition. 5. The liquid crystal composition according to claim 4, wherein the proportion of the compound represented by formula (2) is in the range of 10% by weight to 70% by weight based on the weight of the liquid crystal composition. 5. The liquid crystal composition according to claim 1, containing at least one compound selected from the group of compounds represented by formula (3).

In formula (3),
R ³¹ and R ³² are hydrogen or alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— or —S— and at least one — (CH ₂ ) ₂ — may be replaced by —CH═CH— or —C≡C— and in these groups at least one hydrogen may be replaced by halogen;
Z ³¹ and Z ³² are a single bond, —C≡C—, or —C≡C—C≡C—;
^L31 , ^L32 , ^L33 , ^L34 , ^L35 , ^L36 , and ^L37 are hydrogen, halogen, methyl, ethyl, or cyclopropyl;
e is 0 or 1; 11. The liquid crystal composition according to claim 10, containing at least one compound selected from the group of compounds represented by formulas (3-1) to (3-5).

In formulas (3-1) to (3-5),
R ^31′ and R ^32′ are alkyl having 1 to 12 carbon atoms, in which at least one —CH ₂ — may be replaced with —O— and at least one —(CH ₂ ) ₂ - may be replaced by -CH=CH- or -C≡C-;
L ^31′ , L ^32′ , L ^33′ , L ^34′ , L ^35′ , L ^36′ and L ^37′ are hydrogen, fluorine, chlorine, methyl or ethyl. 11. The liquid crystal composition according to claim 10, wherein the proportion of the compound represented by formula (3) is in the range of 5% by weight to 65% by weight based on the weight of the liquid crystal composition. 2. The liquid crystal composition according to claim 1, wherein the refractive index anisotropy at 25[deg.] C. at a wavelength of 589 nm is 0.35 or more. 2. The liquid crystal composition according to claim 1, wherein the dielectric anisotropy at 25[deg.] C. is 2 or more in the frequency range of less than 1 MHz. 2. The liquid crystal composition according to claim 1, wherein the dielectric anisotropy at 25[deg.] C. ranges from 0.50 to 3.0 at any frequency from 1 GHz to 10 THz. 2. The liquid crystal composition according to claim 1, comprising an optically active compound. 2. The liquid crystal composition according to claim 1, comprising a polymerizable compound. 2. The liquid crystal composition according to claim 1, containing at least one of an antioxidant, an ultraviolet absorber, an antistatic agent, and a dichroic dye. 3. A device containing the liquid crystal composition according to claim 1, used for switching, wherein the dielectric constant can be reversibly controlled by reversibly changing the orientation direction of the liquid crystal molecules. A device used for controlling electromagnetic waves in the frequency range from 1 GHz to 10 THz, containing the liquid crystal composition according to claim 1 . A liquid crystal lens or a birefringent lens for stereoscopic image display, comprising the liquid crystal composition according to claim 1 .