CN111320990A

CN111320990A - Liquid crystal composition and element for phase control of electromagnetic wave signals

Info

Publication number: CN111320990A
Application number: CN201910921580.0A
Authority: CN
Inventors: 冈部英二
Original assignee: JNC Corp; JNC Petrochemical Corp
Current assignee: JNC Corp; JNC Petrochemical Corp
Priority date: 2018-12-13
Filing date: 2019-09-27
Publication date: 2020-06-23
Also published as: JP2020097719A

Abstract

The invention relates toA liquid crystal composition and a device for phase control of electromagnetic wave signals. The present invention addresses the problem of seeking a liquid crystal composition which has a high upper limit temperature of a nematic phase, a low lower limit temperature of the nematic phase, a large optical anisotropy in a frequency region used for phase control, a small dielectric loss, and thermal stability, and which has an excellent balance of properties, as a material for use in an element for phase control of an electromagnetic wave signal having a frequency of 1MHz to 400 THz. A liquid crystal composition containing at least one compound selected from the group of compounds represented by formula (1) and at least one compound selected from the group of compounds represented by formula (2) and used for phase control of an electromagnetic wave signal of any frequency of 1MHz to 400 THz.

Description

Liquid crystal composition and element for phase control of electromagnetic wave signals

Technical Field

The present invention relates to an element for controlling the phase of an electromagnetic wave signal having a frequency of 1MHz to 400THz and a liquid crystal composition used for the element.

Background

Examples of the element for controlling the phase of the electromagnetic wave signal having a frequency of 1MHz to 400THz include a millimeter wave band or microwave band antenna, an infrared laser element, and the like. Various methods have been studied for these elements, but a method using a liquid crystal which is considered to have few failures due to the absence of a mechanically movable portion has been attracting attention.

The orientation of the molecules of the liquid crystal changes according to an external bias electric field, and the dielectric constant changes. By utilizing such properties, for example, a microwave device capable of electrically controlling the transmission characteristics of a high-frequency transmission line from the outside can be realized. As such a device, a voltage-controlled millimeter-wave band variable phase shifter in which a waveguide is filled with nematic liquid crystal, a microwave/millimeter-wave band wide-band variable phase shifter using nematic liquid crystal as a dielectric substrate of a microstrip line, and the like have been reported (patent documents 1 and 2).

Liquid crystal compositions used in the above-mentioned devices are disclosed in the following patent documents 3 to 4.

[ Prior art documents ]

[ patent document ]

[ patent document 1] International publication No. 2017/201515

[ patent document 2] U.S. publication No. 2018/0239213

[ patent document 3] Japanese patent laid-open No. 2004-285085

[ patent document 4] Japanese patent laid-open publication No. 2011-

Disclosure of Invention

[ problems to be solved by the invention ]

Such an element for controlling the phase of an electromagnetic wave signal desirably has characteristics such as a wide usable temperature range, high gain, and low loss. Therefore, the characteristics of the liquid crystal composition require high upper limit temperature of the nematic phase, low lower limit temperature of the nematic phase, low viscosity, large optical anisotropy in the frequency region used for phase control, large dielectric anisotropy, small dielectric loss, large specific resistance in the drive frequency region, stability against heat, and the like.

The present invention has an object to provide a liquid crystal composition having the above-mentioned required characteristics and an excellent balance of characteristics as a material for use in an element for controlling the phase of an electromagnetic wave signal having a frequency of 1MHz to 400 THz.

[ means for solving problems ]

The inventors have made an intensive study and as a result, have found that a liquid crystal composition comprising a liquid crystal compound having a specific structure solves the problems, thereby completing the present invention.

The present invention includes the following configurations.

A liquid crystal composition containing at least one compound selected from the group of compounds represented by formula (1) and at least one compound selected from the group of compounds represented by formula (2) and used for phase control of an electromagnetic wave signal of any frequency of 1MHz to 400 THz.

In the formulae (1) and (2), R¹¹、R¹²And R²Each independently is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms or an alkoxyalkyl group having 2 to 12 carbon atoms; ring A¹Ring A²¹Ring A²²And ring A²³Each independently is 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene,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, or tetrahydropyran-2, 5-diyl; z¹、Z²¹、Z²²And Z²³Each independently a single bond, ethylene, ethenylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy, ethynylene, or tetrafluoroethylene, with the proviso that Z is²¹、Z²²And Z²³At least one of which is difluoromethyleneoxy; x¹、X²¹、X²²And X²³Each independently hydrogen or fluorine, but X²¹And X²²Will not be fluorine at the same time; y is²Is fluorine, chlorine, at least one alkyl group having 1 to 12 carbon atoms which may be substituted with halogen, at least one alkoxy group having 1 to 12 carbon atoms which may be substituted with halogen, or at least one alkenyl group having 2 to 12 carbon atoms which may be substituted with halogen; n is²Is 1 or 2, when n²When 2 is represented, a plurality of rings A are present²²And Z²²The same or different.

Item 2. the liquid crystal composition according to item 1, which contains at least one compound selected from the group of compounds represented by formulae (1-1) to (1-13).

In the formulae, R¹¹And R¹²Each independently is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms.

Item 3. the liquid crystal composition according to item 1 or item 2, wherein the proportion of the compound represented by formula (1) according to item 1 is in the range of 10 to 70% by weight based on the weight of the liquid crystal composition.

Item 4. the liquid crystal composition according to any one of item 1 to item 3, which contains at least one compound selected from the group of compounds represented by formulae (2-1) to (2-15).

In the formulae, R²Is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms or an alkoxyalkyl group having 2 to 12 carbon atoms in total.

Item 5. the liquid crystal composition according to any one of item 1 to item 4, wherein the proportion of the compound represented by formula (2) according to item 1 is in the range of 5% by weight to 55% by weight based on the weight of the liquid crystal composition.

Item 6. the liquid crystal composition according to any one of item 1 to item 5, further containing at least one compound selected from the group of compounds represented by formula (3).

In the formula (3), R³Is alkyl group with carbon number of 1 to 12, alkoxy group with carbon number of 1 to 12 or alkenyl group with carbon number of 2 to 12; ring A³¹Ring A³²And ring A³³Each independently is 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 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, or tetrahydropyran-2, 5-diyl; z³¹、Z³²And Z³³Each independently a single bond, ethylene, ethenylene, methyleneoxy, carbonyloxy, ethynylene, or tetrafluoroethylene; x³¹、X³²And X³³Each independently hydrogen or fluorine, but X³¹And X³²Will not be fluorine at the same time; y is³Is fluorine, chlorine, at least one alkyl group having 1 to 12 carbon atoms which may be substituted with halogen, at least one alkoxy group having 1 to 12 carbon atoms which may be substituted with halogen, or at least one alkenyl group having 2 to 12 carbon atoms which may be substituted with halogen; n is³Is 0, 1 or 2, when n³When 2, there are a plurality of rings A³²And Z³²The same or different.

Item 7. the liquid crystal composition according to item 6, which contains at least one compound selected from the group of compounds represented by formulae (3-1) to (3-12).

In the formulae, R³Is alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms or alkenyl group having 2 to 12 carbon atoms.

Item 8 the liquid crystal composition according to item 6 or item 7, wherein the proportion of the compound represented by formula (3) is in the range of 3 to 40% by weight based on the weight of the liquid crystal composition.

Item 9. the liquid crystal composition according to any one of item 1 to item 8, further containing at least one compound selected from the group of compounds represented by formula (4).

In the formula (4), R⁴¹And R⁴²Each independently is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms; ring A⁴¹And ring A⁴²Each independently is 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 2, 5-difluoro-1, 4-phenylene, 2, 6-difluoro-1, 4-phenylene or 2, 6-benzothiophene; z⁴¹Is a single bond, ethylene, ethenylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy, ethynylene, or tetrafluoroethylene; z⁴²Is a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy, or tetrafluoroethylene; x⁴¹And X⁴²Each independently hydrogen or fluorine, but X⁴¹And X⁴²Will not be fluorine at the same time; n is⁴Is 0, 1 or 2, when n⁴When 1 or 2, Z⁴¹Is not an ethynylene group, when n⁴When 2, there are a plurality of rings A⁴²And Z⁴²The same or different.

Item 10. the liquid crystal composition according to item 9, which contains at least one compound of the group of compounds represented by formulae (4-1) to (4-20).

In the formulae, R⁴¹And R⁴²Each independently is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms.

Item 11. the liquid crystal composition according to item 9 or item 10, wherein the proportion of the compound represented by formula (4) is in the range of 10% by weight to 70% by weight based on the weight of the liquid crystal composition.

Item 12 the liquid crystal composition according to any one of item 1 to item 11, wherein an optical anisotropy at a wavelength of 589nm at 25 ℃ is in a range of 0.18 to 0.35, and a dielectric anisotropy at a frequency of 1kHz at 25 ℃ is in a range of 3 to 40.

The liquid crystal composition according to any one of items 1 to 12, wherein the optical anisotropy at 25 ℃ at any frequency of 1GHz to 50GHz is in the range of 0.10 to 0.40.

The liquid crystal composition according to any one of items 1 to 13, which comprises an optically active compound.

The liquid crystal composition according to any one of items 1 to 14, which comprises a polymerizable compound.

An element which contains the liquid crystal composition according to any one of items 1 to 15 and is used for phase control of an electromagnetic wave signal of any frequency of 1MHz to 400 THz.

[ Effect of the invention ]

The composition of the present invention has a high upper limit temperature of a nematic phase, a low lower limit temperature of a nematic phase, a large optical anisotropy in a frequency region used for phase control, a small dielectric loss, and stability to heat. Therefore, an element using the material has characteristics of excellent practicality.

Drawings

Is free of

[ description of symbols ]

Is free of

Detailed Description

The usage of the terms in the present specification is as follows. The term "liquid crystal composition" is sometimes simply referred to as "composition". At least one compound selected from the group of compounds represented by formula (1) may be abbreviated as "compound (1)". The "compound (1)" means one compound or two or more compounds represented by the formula (1). The same applies to the compounds represented by the other formulae. "at least one" in relation to "may be substituted" means that not only the position but also the number thereof may be selected without limitation.

The liquid crystal composition is prepared by mixing a plurality of liquid crystalline compounds. The proportion (content) of the liquid crystalline compound is represented by a weight percentage (wt%) based on the weight of the liquid crystal composition. Additives such as optically active compounds, antioxidants, ultraviolet absorbers, pigments, antifoaming agents, polymerizable compounds, polymerization initiators, and polymerization inhibitors are optionally added to the liquid crystal composition. The proportion (addition amount) of the additive is represented by a weight percentage (wt%) based on the weight of the liquid crystal composition, as in the case of the proportion of the liquid crystalline compound. Parts per million (ppm) by weight are also sometimes used. The proportions of the polymerization initiator and the polymerization inhibitor are exceptionally represented on the basis of the weight of the polymerizable compound.

The "upper limit temperature of the nematic phase" may be simply referred to as "upper limit temperature". The "lower limit temperature of the nematic phase" may be simply referred to as "lower limit temperature". The "large specific resistance" means that the composition has a large specific resistance not only at room temperature but also at a temperature close to the upper limit temperature of the nematic phase in the initial stage, and also has a large specific resistance not only at room temperature but also at a temperature close to the upper limit temperature of the nematic phase after long-term use.

The expression "at least one 'A' may be substituted with 'B' means that the number of 'A's is arbitrary. When the number of 'a' is one, the position of 'a' is arbitrary, and when the number of 'a' is two or more, the positions of 'a' may be selected without limitation. The rules also apply to the expression "at least one 'a' is substituted with 'B'.

In the chemical formula of the component compound, the end group R¹¹The notation of (a) is used for a variety of compounds. In these compounds, any two R¹¹The two radicals indicated may be identical or may also be different. For example, R in the presence of the compound (1-1)¹¹R of Compound (1-2) being ethyl¹¹In the case of ethyl. R of the compound (1-1) is also present¹¹R of Compound (1-2) being ethyl¹¹In the case of propyl. The rule also applies to R¹²、R²、R³、R⁴¹、R⁴²And so on. In the formula (2), when n²When 2, there are two rings A²². In the compounds, two rings A²²The two rings represented may be the same or may also be different. The rule also applies to Z²²Ring A³²、Z³²Ring A⁴²、Z⁴²And the like.

2-fluoro-1, 4-phenylene refers to the following two divalent radicals. In the formula, fluorine may be either to the left (L) or to the right (R). The rules also apply to divalent radicals 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, tetrahydropyran-2, 5-diyl.

The present invention also includes the following items. (a) The composition further contains at least one additive selected from the group consisting of an optically active compound, an antioxidant, an ultraviolet absorber, a pigment, an antifoaming agent, a polymerizable compound, a polymerization initiator, and a polymerization inhibitor. (b) An element comprising the composition. (c) An element comprising the composition and having a phase-change (PC), Twisted Nematic (TN), Super Twisted Nematic (STN), Electrically Controlled Birefringence (ECB), Optically Compensated Bend (OCB), in-plane switching (IPS), Vertical Alignment (VA), Fringe Field Switching (FFS) or field-induced photo-reactive (FPA) mode. (d) The composition is used as a composition having a nematic phase. (e) Is used as an optically active composition by adding an optically active compound to the composition.

The composition of the present invention is illustrated in the following order. First, the composition of the component compounds in the composition will be described. Secondly, the main characteristics of the component compounds and the main effects of the compounds on the composition will be described. Third, the combination of the components in the composition, the preferred proportions of the components, and their basis are described. Fourth, preferred embodiments of the component compounds will be described. Fifth, preferred component compounds are shown. Sixth, additives that can be added to the composition will be described. Finally, the use of the composition is illustrated.

First, the composition of the component compounds in the composition will be described. The compositions of the present invention are classified as composition a and composition B. The composition a may contain other liquid crystalline compounds, additives, and the like in addition to the liquid crystalline compound selected from the group consisting of the compound (1), the compound (2), the compound (3), and the compound (4). The "other liquid crystalline compound" is a liquid crystalline compound different from the compound (1), the compound (2), the compound (3) and the compound (4). Such compounds are mixed in the composition for the purpose of further adjusting the properties. The additive is an optically active compound, an antioxidant, an ultraviolet absorber, a pigment, an antifoaming agent, a polymerizable compound, a polymerization initiator, a polymerization inhibitor, or the like.

The composition B substantially contains only a liquid crystalline compound selected from the group consisting of the compound (1), the compound (2), the compound (3) and the compound (4). "substantially" means that the composition may contain additives but does not contain other liquid crystalline compounds. The amount of ingredients of composition B is small compared to composition a. From the viewpoint of cost reduction, composition B is superior to composition a. From the viewpoint that the characteristics can be further adjusted by mixing other liquid crystalline compounds, the composition a is superior to the composition B.

Secondly, the main characteristics of the component compounds and the main effects of the compounds on the characteristics of the composition will be described. The main properties of the component compounds are summarized in table 1 based on the effects of the present invention. In the notation of table 1, L means large or high, M means medium, and S means small or low. The notation L, notation M, notation S are classifications based on qualitative comparisons between component compounds, with 0 (zero) meaning a value of approximately zero or near zero.

Characterization of the Compounds of Table 1

Compound (I)	(1)	(2)	(3)	(4)
					Upper limit temperature	M～L	M～L	M～L	S～L
Viscosity of the oil	M	M～L	M～L	S～M
					Optical anisotropy	L	M～L	M～L	L
Dielectric anisotropy	0	M～L	M～L	0
					Specific resistance	L	L	L	L

When the component compounds are mixed in the composition, the main effects of the component compounds on the characteristics of the composition are as follows. The compound (1) improves optical anisotropy. The compound (2) enhances the dielectric anisotropy. The compound (3) enhances the dielectric anisotropy. The compound (4) increases the optical anisotropy and increases the upper limit temperature or decreases the lower limit temperature.

Third, the combination of the components in the composition, the preferred ratio of the component compounds, and the basis thereof will be described. The combination of the components in the composition is compound (1) + compound (2), compound (1) + compound (2) + compound (3), compound (1) + compound (2) + compound (4), or compound (1) + compound (2) + compound (3) + compound (4). Preferred combinations of ingredients in the composition are compound (1) + compound (2) + compound (4) or compound (1) + compound (2) + compound (3) + compound (4), and particularly preferred combinations are compound (1) + compound (2) + compound (3) + compound (4).

The preferable proportion of the compound (1) is about 10% by weight or more in order to increase the optical anisotropy or to increase the upper limit temperature, and the preferable proportion of the compound (1) is about 70% by weight or less in order to increase the dielectric anisotropy, based on the weight of the liquid crystal composition. More preferred ratios range from about 10% to about 60% by weight. Particularly preferred ratios range from about 10% to about 50% by weight.

The preferable proportion of the compound (2) is about 5% by weight or more for increasing the dielectric anisotropy or for increasing the upper limit temperature, and the preferable proportion of the compound (2) is about 55% by weight or less for increasing the optical anisotropy or for decreasing the lower limit temperature, based on the weight of the liquid crystal composition. More preferred ratios range from about 10% to about 50% by weight. Particularly preferred ratios range from about 10 wt% to about 45 wt%.

The preferable proportion of the compound (3) is about 3% by weight or more for increasing the dielectric anisotropy or for increasing the upper limit temperature, and the preferable proportion of the compound (3) is about 40% by weight or less for increasing the optical anisotropy or for decreasing the lower limit temperature, based on the weight of the liquid crystal composition. More preferred ratios range from about 3% to about 30% by weight. Particularly preferred ratios range from about 3 wt% to about 20 wt%.

The preferable proportion of the compound (4) is about 10% by weight or more in order to increase the optical anisotropy and to increase the upper limit temperature or decrease the lower limit temperature, and the preferable proportion of the compound (4) is about 70% by weight or less in order to increase the dielectric anisotropy, based on the weight of the liquid crystal composition. More preferred ratios range from about 10 wt% to about 65 wt%. Particularly preferred ratios range from about 15 wt% to about 65 wt%.

Fourth, preferred embodiments of the component compounds will be described. R¹¹、R¹²And R²Each independently is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkoxyalkyl group having 2 to 12 carbon atoms in total. Preferred R for enhanced stability to ultraviolet light or heat¹¹、R¹²And R²Is an alkyl group having 1 to 12 carbon atoms. R³、R⁴¹And R⁴²Each independently is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. Preferred R for enhanced stability to ultraviolet light or heat³、R⁴¹And R⁴²Is an alkyl group having 1 to 12 carbon atoms.

Preferred alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl or octyl. More preferred alkyl groups are ethyl, propyl, butyl, pentyl or heptyl for reducing viscosity.

Preferred alkoxy groups are methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy or heptoxy. More preferred alkoxy groups are methoxy or ethoxy groups in order to reduce viscosity.

Preferred alkenyl groups are vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl or 5-hexenyl. More preferred alkenyl groups are vinyl, 1-propenyl, 3-butenyl or 3-pentenyl in order to reduce viscosity. The preferred steric configuration of-CH ═ CH-in these alkenyl groups depends on the position of the double bond. Among alkenyl groups such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl, 3-hexenyl, the trans (trans) configuration is preferred in view of reducing viscosity and the like. Among alkenyl groups such as 2-butenyl, 2-pentenyl, 2-hexenyl, the cis (cis) configuration is preferred. Among these alkenyl groups, a straight-chain alkenyl group is preferable to a branched alkenyl group.

Preferred alkoxyalkyl is-CH₂OCH₃、-CH₂OC₂H₅、-CH₂OC₃H₇、-(CH₂)₂-OCH₃、-(CH₂)₂-OC₂H₅、-(CH₂)₂-OC₃H₇、-(CH₂)₃-OCH₃、-(CH₂)₄-OCH₃And- (CH)₂)₅-OCH₃。

n²Is 1 or 2. For raising the upper limit temperature or lowering the lower limit temperature, or for loweringLow viscosity, preferably n²Is 1. n is³Is 0, 1 or 2. For raising the upper limit temperature or lowering the lower limit temperature, or for lowering the viscosity, n is preferable³Is 0 or 1. n is⁴Is 0, 1 or 2. For lowering the lower temperature limit or for lowering the viscosity, n is preferred⁴Is 0.

Z¹And Z⁴¹Each independently a single bond, ethylene, ethenylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy, ethynylene, or tetrafluoroethylene. For reducing the viscosity, preferred is Z¹And Z⁴¹Independently a single bond, respectively, and Z is preferably a group of Z for improving optical anisotropy¹And Z⁴¹Each independently is an ethynylene group. Z⁴²Is a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy, or tetrafluoroethylene. For reducing the viscosity, preferred is Z⁴²Is a single bond. Z²¹、Z²²And Z²³Each independently a single bond, ethylene, ethenylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy, ethynylene, or tetrafluoroethylene. For reducing the viscosity, preferred is Z²¹、Z²²And Z²³Independently a single bond, respectively, and preferably Z for improving dielectric anisotropy²¹、Z²²And Z²³Each independently is difluoromethyleneoxy. Z³¹、Z³²And Z³³Each independently a single bond, ethylene, ethenylene, methyleneoxy, carbonyloxy, ethynylene, or tetrafluoroethylene. For reducing the viscosity, preferred is Z³¹、Z³²And Z³³Independently a single bond, respectively, and Z is preferably a group of Z for improving optical anisotropy³¹、Z³²And Z³³Each independently is an ethynylene group.

Ring A¹Ring A²¹Ring A²²And ring A²³Each independently is 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 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, or tetrahydropyran-2, 5-diyl. Preferred rings A for the purpose of improving optical anisotropy¹Ring A²¹Ring A²²And ring A²³Each independently is 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 2, 5-difluoro-1, 4-phenylene or 2, 6-difluoro-1, 4-phenylene. Ring A³¹Ring A³²And ring A³³Each independently is 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 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, or tetrahydropyran-2, 5-diyl. Preferred rings A for the purpose of improving optical anisotropy³¹Ring A³²And ring A³³Each independently is 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 2, 5-difluoro-1, 4-phenylene or 2, 6-difluoro-1, 4-phenylene. Ring A⁴¹And ring A⁴²Each independently is 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 2, 5-difluoro-1, 4-phenylene, 2, 6-difluoro-1, 4-phenylene or 2, 6-benzothiophene. Preferred rings A for the purpose of improving optical anisotropy⁴¹And ring A⁴²Each independently is 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 2, 5-difluoro-1, 4-phenylene or 2, 6-difluoro-1, 4-phenylene. In order to raise the upper limit temperature, the steric configuration associated with the 1, 4-cyclohexylene group is a trans configuration rather than a cis configuration. Tetrahydropyran-2, 5-diyl as

Or

Preferably, it is

X¹、X²¹、X²²、X²³、X³¹、X³²、X³³、X⁴¹And X⁴²Each independently hydrogen or fluorine, but X²¹And X²²Not being simultaneously fluorine, X³¹And X³²Will not be fluorine at the same timeIn addition, X⁴¹And X⁴²Nor will they be both fluorine. For enhancing dielectric anisotropy, preferred is X¹、X²¹、X²²、X²³、X³¹、X³²、X³³、X⁴¹And X⁴²Each independently being fluorine.

Y²And Y³Each independently is fluorine, chlorine, an alkyl group having 1 to 12 carbon atoms which may be substituted with halogen at least one hydrogen, an alkoxy group having 1 to 12 carbon atoms which may be substituted with halogen at least one hydrogen, or an alkenyl group having 2 to 12 carbon atoms which may be substituted with halogen at least one hydrogen. For enhancing dielectric anisotropy, Y is preferable²And Y³Is fluorine.

Fifth, preferred component compounds are shown. Preferred compounds (1) are the following compounds (1-1) to (1-13).

Of these compounds, it is preferable that at least one of the compounds (1) is a compound (1-3), a compound (1-4) or a compound (1-5). Preferably, at least two of the compounds (1) are a combination of the compounds (1-3) and the compounds (1-5) or the compounds (1-4) and the compounds (1-5).

Preferred compounds (2) are the following compounds (2-1) to (2-15).

Of these compounds, it is preferable that at least one of the compounds (2) is the compound (2-1), the compound (2-2), the compound (2-9) or the compound (2-10). Preferably, at least two of the compounds (2) are a combination of the compound (2-1) and the compound (2-10), the compound (2-2) and the compound (2-10), or the compound (2-9) and the compound (2-10).

Preferred compounds (3) are the following compounds (3-1) to (3-12).

Of these compounds, it is preferable that at least one of the compounds (3) is the compound (3-4) or the compound (3-5). Preferably, at least two of the compounds (3) are a combination of the compounds (3-4) and the compounds (3-5).

Preferred compounds (4) are the following compounds (4-1) to (4-20).

Of these compounds, it is preferable that at least one of the compounds (4) is the compound (4-2), the compound (4-3), the compound (4-8), the compound (4-9) or the compound (4-13). Preferably, at least two of the compounds (4) are a combination of the compounds (4-3) and (4-8), the compounds (4-3) and (4-9), or the compounds (4-3) and (4-13).

Sixth, additives that can be added to the composition will be described. Such additives include optically active compounds, antioxidants, ultraviolet absorbers, pigments, antifoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, and the like. Hereinafter, unless otherwise specified, the mixing ratio of these additives is a ratio (weight) based on the weight of the liquid crystal composition.

An optically active compound is added to the composition for the purpose of inducing a helical structure of the liquid crystal to impart a twist angle (torsion angle). Examples of such compounds are compound (5-1) to compound (5-5). The preferable proportion of the optically active compound is about 5% by weight or less. More preferred ratios range from about 0.01 wt% to about 2 wt%.

An antioxidant is added to the composition in order to prevent a decrease in specific resistance caused by heating in the atmosphere or to maintain a large voltage holding ratio at room temperature and also at a temperature close to the upper limit temperature after the device is used for a long time. Preferable examples of the antioxidant include a compound (6) wherein t is an integer of 1 to 9, and the like.

In the compound (6), t is preferably 1,3, 5, 7 or 9. More preferably t is 7. Since the compound (6) having t of 7 has low volatility, it is effective for maintaining a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after the device is used for a long time. In order to obtain the above effect, the preferable ratio of the antioxidant is about 50ppm or more, and in order not to lower the upper limit temperature or to raise the lower limit temperature, the preferable ratio of the antioxidant is about 600ppm or less. More preferred ratios range from about 100ppm to about 300 ppm.

Preferable examples of the ultraviolet absorber include benzophenone derivatives, benzoate derivatives, triazole derivatives and the like. Light stabilizers such as sterically hindered amines are also preferred. The preferable proportion of these absorbents or stabilizers is about 50ppm or more in order to obtain the effect, and about 10000ppm or less in order not to lower the upper limit temperature or not to raise the lower limit temperature. More preferred ratios range from about 100ppm to about 10000 ppm.

In order to be suitable for a guest-host (GH) mode element, a dichroic dye (dichromatic dye) such as an azo dye or an anthraquinone dye is added to the composition. The preferred proportion of pigment ranges from about 0.01% to about 10% by weight. In order to prevent foaming, an antifoaming agent such as dimethylsilicone oil or methylphenylsilicone oil is added to the composition. The preferable ratio of the defoaming agent is about 1ppm or more in order to obtain the above effects, and about 1000ppm or less in order to prevent display failure. More preferred ratios range from about 1ppm to about 500 ppm.

In order to be suitable for a device stabilized with a polymer, a polymerizable compound is added to the composition. Preferable examples of the polymerizable compound include compounds having a polymerizable group such as an acrylate, a methacrylate, a vinyl compound, an ethyleneoxy compound, a propenyl ether, an epoxy compound (oxetane ) and a vinyl ketone. More preferred examples are derivatives of acrylates or methacrylates. In order to obtain the above-mentioned effects, the preferable ratio of the polymerizable compound is about 0.05 wt% or more, and in order to prevent the display failure, the preferable ratio of the polymerizable compound is about 20 wt% or less. More preferred ratios range from about 0.1 wt% to about 10 wt%. The polymerizable compound is polymerized by ultraviolet irradiation. The polymerization may be carried out in the presence of an initiator such as a photopolymerization initiator. Suitable conditions for the polymerization, suitable types and suitable amounts of initiators are known to the person skilled in the art and are described in the literature. For example, brilliant good solid (Irgacure)651 (registered trademark; Basf), brilliant good solid (Irgacure)184 (registered trademark; Basf), or Delocure (Darocure)1173 (registered trademark; Basf) as a photopolymerization initiator is suitable for radical polymerization. The preferable proportion of the photopolymerization initiator ranges from about 0.1 part by weight to about 5 parts by weight based on 100 parts by weight of the polymerizable compound. More preferred ratios range from about 1 part by weight to about 3 parts by weight.

When the polymerizable compound is stored, a polymerization inhibitor may be added to prevent polymerization. The polymerizable compound is usually added to the composition in a state where the polymerization inhibitor is not removed. Examples of the polymerization inhibitor are hydroquinone, hydroquinone derivatives such as methyl hydroquinone, 4-t-butyl catechol, 4-methoxy phenol, phenothiazine and the like.

Finally, the use of the composition is illustrated. The compositions of the present invention have primarily a lower temperature limit of about-10 ℃ or less, an upper temperature limit of about 70 ℃ or more, and an optical anisotropy in the range of about 0.18 to about 0.35. By controlling the ratio of the component compounds, or by mixing other liquid crystalline compounds, a composition having an optical anisotropy in the range of about 0.10 to about 0.18, and further a composition having an optical anisotropy in the range of about 0.35 to about 0.40 can be prepared. The composition can be used as a composition having a nematic phase, and can be used as an optically active composition by adding an optically active compound.

The composition can be used in an element for phase control of electromagnetic wave signals having a frequency of 1MHz to 400 THz. Examples of the application include a millimeter wave band variable phase shifter, a laser radar (LiDAR) element, and the like.

In the mode utilizing the optical change caused by the kerr effect, it is desirable that the product of the optical anisotropy and the dielectric anisotropy of the composition is large, and therefore, it is preferable that the optical anisotropy of the composition is as large as possible. The optical anisotropy is preferably in the range of 0.18 to 0.35, and more preferably in the range of 0.20 to 0.32.

In order to reduce the driving voltage of the device, it is desirable that the dielectric anisotropy of the composition is large. In particular, in a mode in which an electric field applied to the liquid crystal composition is limited by polymer stabilization, encapsulation, or the like, the driving voltage tends to be high, and therefore the dielectric anisotropy is preferably as large as possible. In addition, in a mode utilizing an optical change due to the kerr effect, it is desirable that the product of the optical anisotropy and the dielectric anisotropy is large, and therefore the dielectric anisotropy is preferably as large as possible. The dielectric anisotropy is preferably in the range of 3 to 40, more preferably in the range of 3 to 20.

Examples

The present invention will be described in more detail by way of examples. The present invention is not limited by these examples. The invention also includes mixtures of at least two of the compositions of the examples. The synthesized compound is identified by Nuclear Magnetic Resonance (NMR) analysis or the like. The properties of the compounds and compositions were measured by the methods described below.

NMR analysis: DRX-500 manufactured by Bruker BioSpin was used for the measurement. In that¹In the measurement of H-NMR, a sample was dissolved in CDCl₃The measurement was performed at room temperature in a deuterated solvent at 500MHz for 16 cumulative times. Tetramethylsilane was used as an internal standard. In that¹⁹In the measurement of F-NMR, CFCl was used₃As an internal standard, the number of times is accumulated to 24 times. In the description of the nmr spectra, s represents a singlet (singlet), d a doublet (doublt), t a triplet (triplet), q a quartet (quatet), quin a quintet (quintet), sex a sextant (sextet), m a multiplet (multiplet), and br a broad (broad).

Gas chromatographic analysis: for measurement, a GC-14B gas chromatograph manufactured by Shimadzu corporation was used. The carrier gas was helium (2 mL/min). The sample vaporization chamber was set at 280 ℃ and the detector (Flame ionization detector, FID) was set at 300 ℃. In the separation of the component compounds, a capillary column DB-1 (length of 30m, inner diameter of 0.32mm, film thickness of 0.25 μm; stationary liquid phase of dimethylpolysiloxane; non-polar) manufactured by Agilent technologies Inc. was used. The column was held at 200 ℃ for 2 minutes and then heated to 280 ℃ at a rate of 5 ℃/min. After preparing the sample into an acetone solution (0.1 wt%), 1. mu.L thereof was injected into the sample vaporization chamber. The record is a chromatograph element (Chromatopac) of the C-R5A type manufactured by Shimadzu corporation or an equivalent thereof. The obtained gas chromatogram showed the retention time of the peak and the area of the peak corresponding to the component compound.

As a solvent for diluting the sample, chloroform, hexane, etc. can be used. For separation of the component compounds, the following capillary columns can also be used. HP-1 (30 m in length, 0.32mm in inner diameter and 0.25 μm in film thickness) manufactured by Agilent Technologies Inc., Rtx-1 (30 m in length, 0.32mm in inner diameter and 0.25 μm in film thickness) manufactured by Ralstak Corporation (Restek Corporation), BP-1 (30 m in length, 0.32mm in inner diameter and 0.25 μm in film thickness) manufactured by SGE International Pty.Ltd). In order to prevent the compound peaks from overlapping, capillary columns CBP1-M50-025 (50M in length, 0.25mm in inner diameter, 0.25 μ M in film thickness) manufactured by Shimadzu corporation were also used.

The ratio of the liquid crystalline compound contained in the composition can be calculated by the following method. The mixture of liquid crystalline compounds was detected by gas chromatography (FID). The area ratio of the peaks in the gas chromatogram corresponds to the ratio (weight ratio) of the liquid crystalline compound. When the capillary column described above is used, the correction coefficient of each liquid crystalline compound can be regarded as 1. Therefore, the ratio (% by weight) of the liquid crystalline compound can be calculated from the area ratio of the peak.

The method for measuring the characteristics of a compound comprises the steps of preparing a sample for measurement by mixing the compound (15 wt%) in a mother liquid crystal (85 wt%), calculating the characteristic value of the compound (extrapolated value) { (measured value of the sample) -0.85 × (measured value of the mother liquid crystal) }/0.15 by an extrapolation method based on the value obtained by the measurement, changing the ratio of the compound to the mother liquid crystal to 10 wt%: 90 wt%, 5 wt%: 95 wt%, 1 wt%: 99 wt% in this order when a smectic phase (or crystal) is precipitated at 25 ℃, and determining the values of the upper limit temperature, optical anisotropy, viscosity and dielectric anisotropy associated with the compound by the extrapolation method.

The following mother liquid crystal was used. The proportion of the component compounds is expressed by weight%.

The determination method comprises the following steps: the characteristics were measured by the following methods. Most of these methods are described in JEITA specifications (JEITA ED-2521B) examined and established by the society of Electronics and Information Technology industries, hereinafter referred to as JEITA, or methods for modifying the same. In the TN cell used for the measurement, a Thin Film Transistor (TFT) was not mounted.

Upper limit temperature of nematic phase (NI;. degree. C.): the sample was placed on a hot plate of a melting point measuring apparatus equipped with a polarizing microscope, and heated at a rate of 1 ℃/min. The temperature at which a portion of the sample changes from a nematic phase to an isotropic liquid is measured.

Lower limit temperature (T) of nematic phase_C(ii) a C): the nematic phase was observed after placing the sample in a glass bottle and keeping the bottle in a freezer at 0 ℃, -10 ℃, -20 ℃, -30 ℃ and-40 ℃ for 10 days. For example, when the sample is kept in a nematic phase at-20 ℃ and changed to a crystalline or smectic phase at-30 ℃, T is measured_CIs reported as < -20 ℃.

The viscosity (bulk viscosity; η; measured at 20 ℃ C.; mPas) was measured using a rotary viscometer of type E manufactured by Tokyo instruments Co., Ltd.

Viscosity (rotational viscosity; γ 1; measured at 20 ℃; mPas): the measurement was carried out according to the method described in Molecular Crystals and Liquid Crystals (Molecular Crystals and Liquid Crystals), vol.259,37(1995) of M.J. et al. The sample was placed in a TN cell having a twist angle of 0 ℃ and a gap (cell gap) of 5 μm between two glass substrates. In the range of 16V to 19.5V, a voltage is applied to the element in stages in units of 0.5V. After 0.2 second of no voltage application, voltage application was repeated under the condition of applying only one square wave (square pulse; 0.2 second) and no voltage application (2 seconds). The peak current (peak current) and peak time (peak time) of the transient current (transient current) generated by the application are determined. The values of rotational viscosity were obtained from these measured values and the calculation formula (8) described on page 40 of the paper by M. The value of the dielectric anisotropy required for the calculation was determined by the following method using an element for measuring the rotational viscosity.

Optical anisotropy (refractive index anisotropy; Δ n; measured at 25 ℃) was measured using light having a wavelength of 589nm by an abbe refractometer having a polarizing plate attached to an eyepiece lens, rubbing the surface of a main prism in one direction, then dropping a sample onto the main prism, measuring the refractive index n/when the direction of polarized light was parallel to the direction of rubbing, measuring the refractive index n ⊥ when the direction of polarized light was perpendicular to the direction of rubbing, and calculating the value of optical anisotropy based on the formula Δ n ═ n/n ⊥.

Dielectric anisotropy (. DELTA.. di-elect cons.; measured at 25 ℃ C.) A sample was placed in a TN cell having 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 the cell, and the dielectric constant in the long axis direction of the liquid crystal molecules (. epsilon. /) was measured 2 seconds later, a sine wave (0.5V, 1kHz) was applied to the cell, and the dielectric constant in the short axis direction of the liquid crystal molecules (. epsilon./. sup.) (2 seconds later), and the value of the dielectric anisotropy was calculated from the formula (. DELTA.. di- ε/. sup.) - ε ⊥.

Threshold voltage (Vth; measured at 25 ℃; V): for measurement, a luminance meter model LCD5100 manufactured by tsukamur electronics gmbh was used. The light source is a halogen lamp. The sample was placed in a TN cell of normally white mode (normal white mode) having a cell gap of 0.45/. DELTA.n (μm) between two glass substrates and a twist angle of 80 degrees. The voltage (32Hz, rectangular wave) applied to the element was increased stepwise from 0V to 10V in units of 0.02V. At this time, the element was irradiated with light from the vertical direction, and the amount of light transmitted through the element was measured. A voltage-transmittance curve was prepared in which the transmittance was 100% when the light amount reached the maximum and the transmittance was 0% when the light amount was the minimum. The threshold voltage is represented by a voltage at which the transmittance becomes 90%.

Voltage holding ratio (VHR-1; measured at 25;%): the TN element used for the measurement had a polyimide alignment film, and the interval (cell gap) between the two glass substrates was 5 μm. The element is sealed after the sample is placed with an adhesive that is hardened by ultraviolet rays. The TN cell was charged by applying a pulse voltage (5V, 60 μ sec). The decayed voltage was measured by a high-speed voltmeter for a period of 16.7 milliseconds, and the area a between the voltage curve and the horizontal axis in the unit cycle was determined. The area B is the area when not attenuated. The voltage holding ratio is expressed by the percentage of the area a to the area B.

Voltage holding ratio (VHR-2; measured at 80;%): the voltage holding ratio was measured in the same procedure as described except that the measurement was performed at 80 ℃ instead of the 25 ℃. The obtained value is denoted by VHR-2.

Voltage holding ratio (VHR-3; measured at 25;%): the voltage holding ratio was measured after irradiation with ultraviolet rays, and stability to ultraviolet rays was evaluated. The TN cells used for the measurement had a polyimide alignment film and a cell gap of 5 μm. The sample was injected into the cell and irradiated with light for 20 minutes. The light source was an ultra-high pressure mercury lamp USH-500D (manufactured by Ushio motor), and the spacing between the elements and the light source was 20 cm. In the measurement of VHR-3, the voltage at decay was measured over a period of 16.7 milliseconds. Compositions with large VHR-3 have a large stability to UV light. VHR-3 is preferably 90% or more, more preferably 95% or more.

Voltage holding ratio (VHR-4; measured at 25;%): after the TN cells impregnated with the samples were heated in a thermostatic bath at 80 ℃ for 500 hours, the voltage holding ratio was measured, and the stability to heat was evaluated. In the measurement of VHR-4, the voltage at decay was measured over a period of 16.7 milliseconds. Compositions with large VHR-4 have a large stability to heat.

Response time (. tau.; measured at 25 ℃ C.; ms): for measurement, a luminance meter model LCD5100 manufactured by tsukamur electronics gmbh was used. The light source is a halogen lamp. The Low-pass filter (Low-pass filter) is set to 5 kHz. The sample was placed in a TN cell of normally white mode (normal white mode) having a cell gap of 5.0 μm and a twist angle of 80 degrees between two glass substrates. A square wave (60Hz, 5V, 0.5 sec) was applied to the element. At this time, the element was irradiated with light from the vertical direction, and the amount of light transmitted through the element was measured. The transmittance was regarded as 100% when the amount of light reached the maximum, and 0% when the amount of light was the minimum. The rise time (τ r: rise time; millisecond) is the time required for the transmittance to change from 90% to 10%. The fall time (τ f: fall time; millisecond) is the time required for the transmittance to change from 10% to 90%. The response time is represented by the sum of the rise time and the fall time found in the above manner.

Elastic constant (K; measured at 25 ℃ C.; pN): for the measurement, an LCR meter model HP4284A manufactured by Yokogawa Hewlett packard, Ltd was used. The sample was placed in a horizontally oriented cell having a spacing (cell gap) of 20 μm between two glass substrates. An electric charge of 0V to 20V was applied to the element, and the electrostatic capacitance and the applied voltage were measured. The values of the electrostatic capacitance (C) and the applied voltage (V) were fitted using expressions (2.98) and (2.101) on page 75 of "Liquid Crystal Device Handbook" (japan news agency), and the values of K11 and K33 were obtained from expressions (2.99). Then, the values of K11 and K33 obtained in the past were used in formula (3.18) on page 171 of the "handbook of liquid crystal devices" to calculate K22. The elastic constant is represented by the average value of K11, K22, and K33 obtained as described above.

Specific resistance (. rho.; measurement at 25 ℃ C.;. omega.cm.) 1.0mL of the sample was placed in a vessel equipped with an electrode, a DC voltage (10V) was applied to the vessel, and a DC current was measured 10 seconds later.

The pitch (P; measured at room temperature; μm) was measured by the wedge method, and referring to "liquid crystal review", P196 (issued 2000, pill), a sample was poured into a wedge-shaped cell, left to stand at room temperature for 2 hours, and then the interval between misdirected lines (d2 to d1) was observed by a polarized light microscope (Nikon (stock) trade name MM40/60 series), and the pitch (P) was calculated from the following equation in which the angle of the wedge-shaped cell is represented by θ, where P is 2 × (d2 to d1) × tan θ.

Dielectric constant in the short axis direction (. epsilon. ⊥; measured at 25 ℃) A sample was placed in a TN cell having a cell gap of 9 μm between two glass substrates and a twist angle of 80 degrees, and a sine wave (0.5V, 1kHz) was applied to the cell, and the dielectric constant in the short axis direction of the liquid crystal molecules (. epsilon. ⊥) was measured 2 seconds later.

Optical anisotropy and dielectric loss at 50GHz (measured at 25 ℃ C.)

Optical anisotropy at 50GHz (Δ n (@50GHz)) was measured by the method disclosed in Applied Optics (vol.44, No.7, p1150 (2005)), regarding the optical anisotropy, a variable short-circuit waveguide of V-band to which a window material was attached was filled with a liquid crystal, and held in a static magnetic field of 0.3T for 3 minutes, a microwave of 50GHz was input to the waveguide, and the amplitude ratio of the reflected wave to the incident wave was measured, the direction of the static magnetic field and the tube length of the short were changed to measure, and the refractive index (ne, no) and the loss parameter (α e, α o) were determined, and the optical anisotropy (Δ n (@50GHz)) was calculated from ne-no.

Tan δ (@50GHz) at 50GHz is calculated as dielectric loss (tan δ) ═ ∈ "/∈ ', using the complex dielectric constant (∈', ∈"). The complex dielectric constant is calculated using the refractive index calculated in the preceding term, the loss parameter, and the following relational expression. Here, c is the light velocity of the vacuum. The dielectric loss also exhibits anisotropy, and is therefore described as having a large value.

ε'＝n²-κ²

ε”＝2nκ

α＝2ωc/κ

The compounds in the examples are according to the definitions of table 2 below, indicated by the symbols. In table 2, the number in parentheses after the symbol corresponds to the number of the compound. The symbol (-) indicates other liquid crystalline compounds. The proportion (percentage) of the liquid crystalline compound is a weight percentage (wt%) based on the weight of the liquid crystal composition. Finally, the values of the properties of the composition are summarized.

TABLE 2 expression of compounds using symbols

R-(A₁)-Z₁-·····-Z_n-(A_n)-R’

Example 1 liquid Crystal composition 1

NI＝90.0℃；Tc<-20℃；Δn＝0.246；Δε＝9.4；Vth＝1.88；η＝42.7mPa·s；γ1＝279mPa·s；ρ＝1.3×10¹⁴Ωcm.

The optical anisotropy and dielectric loss at 50GHz of the liquid crystal composition 1 are as follows.

Δn(@50GHz)＝0.16

tanδ(@50GHz)＝0.013

EXAMPLE 2 liquid Crystal composition 2

NI＝104.2℃；Tc<-10℃；Δn＝0.290；Δε＝10.0；Vth＝2.00；η＝37.1mPa·s；γ1＝337mPa·s；ρ＝2.2×10¹³Ωcm.

Example 3 liquid Crystal composition 3

NI＝111.6℃；Tc<-10℃；Δn＝0.243；Δε＝10.2；Vth＝2.18；η＝63.7mPa·s；γ1＝343mPa·s；ρ＝3.6×10¹³Ωcm.

EXAMPLE 4 liquid Crystal composition 4

NI＝118.1℃；Tc<-10℃；Δn＝0.275；Δε＝13.4.

EXAMPLE 5 liquid Crystal composition 5

NI＝118.5℃；Tc<-10℃；Δn＝0.247；Δε＝12.0；Vth＝2.02；η＝70.0mPa·s；γ1＝429mPa·s；ρ＝5.2×10¹³Ωcm.

EXAMPLE 6 liquid Crystal composition 6

NI＝91.8℃；Tc<-10℃；Δn＝0.240；Δε＝17.5；Vth＝1.45；γ1＝349mPa·s；ρ＝2.3×10¹³Ωcm.

EXAMPLE 7 liquid Crystal composition 7

NI＝113.3℃；Tc<-10℃；Δn＝0.292；Δε＝11.1；Vth＝2.01；γ1＝405mPa·s；ρ＝3.3×10¹³Ωcm.

EXAMPLE 8 liquid Crystal composition 8

NI＝93.0℃；Tc<-20℃；Δn＝0.244；Δε＝4.7；Vth＝2.42；γ1＝229mPa·s；ρ＝1.3×10¹⁴Ωcm.

EXAMPLE 9 liquid Crystal composition 9

NI＝100.6℃；Tc<-30℃；Δn＝0.258；Δε＝5.1；η＝36.4mPa·s

EXAMPLE 10 liquid Crystal composition 10

NI＝118.8℃；Tc<-30℃；Δn＝0.259；Δε＝8.2；η＝54.7mPa·s

EXAMPLE 11 liquid Crystal composition 11

NI＝99.3℃；Tc<-20℃；Δn＝0.255；Δε＝5.5；η＝36.4mPa·s

EXAMPLE 12 liquid Crystal composition 12

NI＝113.4℃；Tc<-20℃；Δn＝0.265；Δε＝4.3；η＝39.5mPa·s

EXAMPLE 13 liquid Crystal composition 13

NI＝110.7℃；Tc<-20℃；Δn＝0.279；Δε＝4.3

[ industrial applicability ]

The liquid crystal composition of the present invention sufficiently satisfies at least one of the properties such as a high upper limit temperature, a low lower limit temperature, a large optical anisotropy, and a large positive dielectric anisotropy, or has an appropriate balance between at least two of the properties. The element containing the composition can be used for phase control of electromagnetic wave signals with the frequency of 1 MHz-400 THz.

Claims

1. A liquid crystal composition containing at least one compound selected from the group of compounds represented by formula (1) and at least one compound selected from the group of compounds represented by formula (2) and used for phase control of an electromagnetic wave signal of any frequency of 1MHz to 400 THz;

in the formulae (1) and (2), R¹¹、R¹²And R²Each independently is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms or an alkoxyalkyl group having 2 to 12 carbon atoms; ring A¹Ring A²¹Ring A²²And ring A²³Each independently is 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 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, or tetrahydropyran-2, 5-diyl; z¹、Z²¹、Z²²And Z²³Each independently a single bond, ethylene, ethenylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy, ethynylene, or tetrafluoroethylene, wherein Z²¹、Z²²And Z²³At least one of which is difluoromethyleneoxy; x¹、X²¹、X²²And X²³Each independently is hydrogen or fluorine, wherein X²¹And X²²Will not be fluorine at the same time; y is²Is fluorine, chlorine, at least one alkyl group having 1 to 12 carbon atoms which may be substituted with halogen, at least one alkoxy group having 1 to 12 carbon atoms which may be substituted with halogen, or at least one alkenyl group having 2 to 12 carbon atoms which may be substituted with halogen; n is²Is 1 or 2, when n²When 2, there are a plurality of rings A²²And Z²²The same or different.

2. The liquid crystal composition according to claim 1, which contains at least one compound selected from the group of compounds represented by formulae (1-1) to (1-13);

3. The liquid crystal composition according to claim 1 or 2, wherein the proportion of the compound represented by formula (1) according to claim 1 is in the range of 10 to 70% by weight based on the weight of the liquid crystal composition.

4. The liquid crystal composition according to claim 1 or 2, which contains at least one compound selected from the group of compounds represented by formulae (2-1) to (2-15);

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

6. The liquid crystal composition according to claim 1 or 2, further comprising at least one compound selected from the group of compounds represented by formula (3);

in the formula (3), R³Is alkyl group with carbon number of 1 to 12, alkoxy group with carbon number of 1 to 12 or alkenyl group with carbon number of 2 to 12; ring A³¹Ring A³²And ring A³³Each independently is 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 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, or tetrahydropyran-2, 5-diyl; z³¹、Z³²And Z³³Each independently a single bond, ethylene, ethenylene, methyleneoxy, carbonyloxy, ethynylene, or tetrafluoroethylene; x³¹、X³²And X³³Each independently is hydrogen or fluorine, wherein X³¹And X³²Will not be fluorine at the same time; y is³Is fluorine, chlorine, at least one alkyl group having 1 to 12 carbon atoms which may be substituted with halogen, at least one alkoxy group having 1 to 12 carbon atoms which may be substituted with halogen, or at least one alkenyl group having 2 to 12 carbon atoms which may be substituted with halogen; n is³Is 0, 1 or 2, when n³When 2, there are a plurality of rings A³²And Z³²The same or different.

7. The liquid crystal composition according to claim 6, which contains at least one compound selected from the group of compounds represented by formulae (3-1) to (3-12);

8. The liquid crystal composition according to claim 6, wherein the proportion of the compound represented by formula (3) is in the range of 3 to 40% by weight based on the weight of the liquid crystal composition.

9. The liquid crystal composition according to claim 1 or 2, further comprising at least one compound selected from the group of compounds represented by formula (4);

in the formula (4), R⁴¹And R⁴²Each independently is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an alkenyl group having 2 to 12 carbon atoms; ring A⁴¹And ring A⁴²Each independently is 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 2, 5-difluoro-1, 4-phenylene, 2, 6-difluoro-1, 4-phenylene or 2, 6-benzothiophene; z⁴¹Is a single bond, ethylene, ethenylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy, ethynylene, or tetrafluoroethylene; z⁴²Is a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy, or tetrafluoroethylene; x⁴¹And X⁴²Each independently is hydrogen or fluorine, wherein X⁴¹And X⁴²Will not be fluorine at the same time; n is⁴Is 0, 1 or 2, when n⁴When 1 or 2, Z⁴¹Is not an ethynylene group, when n⁴When 2, there are a plurality of rings A⁴²And Z⁴²The same or different.

10. The liquid crystal composition according to claim 9, which contains at least one compound of the group of compounds represented by formulae (4-1) to (4-20);

11. The liquid crystal composition according to claim 9, wherein the proportion of the compound represented by formula (4) is in the range of 10 to 70% by weight based on the weight of the liquid crystal composition.

12. The liquid crystal composition according to claim 1 or 2, wherein the optical anisotropy at 25 ℃ at a wavelength of 589nm is in the range of 0.18 to 0.35, and the dielectric anisotropy at 25 ℃ at a frequency of 1kHz is in the range of 3 to 40.

13. The liquid crystal composition according to claim 1 or 2, wherein the optical anisotropy at 25 ℃ at any frequency of 1GHz to 50GHz is in the range of 0.10 to 0.40.

14. The liquid crystal composition according to claim 1 or 2, comprising an optically active compound.

15. The liquid crystal composition according to claim 1 or 2, which comprises a polymerizable compound.

16. An element containing the liquid crystal composition according to any one of claims 1 to 15 and used for phase control of an electromagnetic wave signal of any frequency of 1MHz to 400 THz.