WO2022050164A1

WO2022050164A1 - Liquid crystal composition and actuator using same

Info

Publication number: WO2022050164A1
Application number: PCT/JP2021/031318
Authority: WO
Inventors: 聡増山; 拓市林; 涼西村
Original assignee: Ｅｎｅｏｓ株式会社
Priority date: 2020-09-04
Filing date: 2021-08-26
Publication date: 2022-03-10
Also published as: JPWO2022050164A1

Abstract

Provided is a liquid crystal composition having a high dielectric constant in the temperature range where driving of an electronic device is expected. This liquid crystal composition comprises a first compound represented by general formula (1), and a second compound represented by general formula (2).

Description

Liquid crystal composition and actuator using it

The present invention relates to a liquid crystal composition and an actuator using the liquid crystal composition.

In recent years, with the miniaturization of electronic devices, a dielectric having a high dielectric constant is required. For example, Non-Patent Document 1 reports a phenyldioxane-based liquid crystal compound that expresses a liquid crystal phase having an abnormally large dielectric anisotropy (Δε) in a specific temperature range. Further, Patent Document 1 also discloses a liquid crystal material exhibiting a high dielectric constant at a temperature at which a specific liquid crystal phase is developed. Liquid crystal compounds exhibiting such a high dielectric constant are expected to be applied to electronic devices such as displays and actuators.

JP-A-2017-145298

However, the liquid crystal compounds disclosed in Non-Patent Document 1 and Patent Document 1 crystallize at around room temperature (express a crystalline phase). Since it is difficult to cause orientation polarization in the crystalline phase, there is a problem that these liquid crystal compounds cannot obtain a high dielectric constant in the temperature range where the electronic device is expected to be driven.

The present invention solves the above-mentioned problems, and an object of the present invention is to provide a liquid crystal composition having a high dielectric constant in a temperature range where an electronic device is expected to be driven.

According to the first aspect of the present invention, the liquid crystal composition comprises a first compound represented by the following general formula (1) and a second compound represented by the following general formula (2). A liquid crystal composition is provided.

In the general formula (1)
R ¹ is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxy group having 1 to 11 carbon atoms, or an alkoxyalkyl group having 1 to 11 carbon atoms.
A ¹¹ and A ¹² are independently single-bonded, -COO- or -CF ₂ O-, respectively.
B ¹¹ , B ¹² and B ¹³ are independently hydrogen atoms or fluorine atoms, respectively.
D ¹ is a fluorine atom, -CF ₃ or -OCF ₃ .

In the general formula (2)
^R2 is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxy group having 1 to 11 carbon atoms, or an alkoxyalkyl group having 1 to 11 carbon atoms.
A ² is a single bond, -COO- or -CF ₂ O-,
B ²¹ and B ²² are independently hydrogen atoms or fluorine atoms, respectively.

The first compound may be a compound represented by the following chemical formula (3), and the second compound may be a compound represented by the following chemical formula (4).

The ratio of the blending amount of the first compound to the total blending amount of the first compound and the second compound may be 7% by weight to 93% by weight. Further, the ratio of the blending amount of the first compound to the total blending amount of the first compound and the second compound may be 17% by weight to 93% by weight, or 20% by weight to 90% by weight. It may be well, or 30% by weight to 75% by weight.

The ratio of the blending amount of the first compound to the total blending amount of the first compound and the second compound may be 27% by weight to 93% by weight, or 17% by weight to 33% by weight.

The liquid crystal composition may further contain a third compound represented by the following general formula (5).

In the general formula (5)
R ⁵ is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxy group having 1 to 11 carbon atoms, or an alkoxyalkyl group having 1 to 11 carbon atoms.
A ⁵ is a single bond, -COO- or -CF ₂ O-,
B ⁵¹ and B ⁵² are independently hydrogen atoms or fluorine atoms, respectively.
D ⁵ is a fluorine atom, -CF ₃ or -OCF ₃ .

The third compound may be a compound represented by the following chemical formula (6).

The ratio of the compounding amount of the third compound to the total compounding amount of the first compound, the second compound and the third compound is 50% by weight or less, 7% by weight to 18% by weight, 7% by weight to 23% by weight, and 18% by weight. % Or less, or 7% by weight to 35% by weight.

According to the second aspect of the present invention, an actuator containing the liquid crystal composition of the first aspect is provided.

The actuator may include a conductive coil, and the liquid crystal composition may fill the gap between the coils.

The liquid crystal composition of the present invention has a high dielectric constant in a temperature range (for example, near room temperature) where an electronic device is expected to be driven.

FIG. 1 shows the ratio (% by weight) of the blending amount of the first compound to the total blending amount of the first compound and the second compound in the samples 1 to 9 (liquid crystal composition) prepared in Examples, and the phase transition temperature. It is a figure which shows the relationship with. FIG. 2 is a table showing the dielectric constants (ε _r ': the real part of the relative permittivity) of the samples 1 to 9 (liquid crystal compositions) prepared in Examples for each measurement temperature. FIG. 3 is a diagram showing the relationship between the temperature and the dielectric constant (ε _r ': the real part of the relative permittivity) of the samples 1 to 9 (liquid crystal compositions) prepared in Examples. FIG. 4 shows the ratio (% by weight) of the compounding amount of the first compound to the total compounding amount of the first compound and the second compound in the samples 1 to 9 (liquid crystal composition) prepared in the examples, and each measurement temperature. It is a figure which shows the relationship with the permittivity (ε _r ': the real part of the relative permittivity) of. FIG. 5 is a diagram illustrating a synthesis scheme of the first compound represented by the chemical formula (3). FIG. 6 is a diagram illustrating a synthesis scheme of the second compound represented by the chemical formula (4). 7 (a) is a polarizing micrograph of sample 4 prepared in the example at 80 ° C., FIG. 7 (b) is a polarizing micrograph of sample 4 at 60 ° C., and FIG. 7 (c) is. It is a polarizing micrograph of sample 4 at 30 ° C., and FIG. 7 (d) is a polarizing micrograph of sample 4 at 10 ° C. FIG. 8 shows the ratio (% by weight) of the blending amount of the third compound to the total blending amount of the first compound, the second compound and the third compound in the

samples

4 and 10 to 15 (liquid crystal composition) prepared in the examples. ) And the phase transition temperature. FIG. 9 is a table showing the dielectric constants (ε _r ': real part of the relative permittivity) of the

samples

4 and 11 to 15 (liquid crystal compositions) prepared in Examples for each measurement temperature. FIG. 10 is a diagram showing the relationship between the temperature and the dielectric constants (ε _r ': real part of the relative permittivity) of the

samples

4 and 11 to 15 (liquid crystal compositions) prepared in Examples. FIG. 11 shows the ratio (% by weight) of the blending amount of the third compound to the total blending amount of the first compound, the second compound and the third compound in the

samples

4 and 11 to 15 (liquid crystal compositions) prepared in the examples. ) And the permittivity for each measurement temperature (ε _r ': the real part of the relative permittivity). FIG. 12 is a diagram illustrating a synthetic scheme of the third compound represented by the chemical formula (6). FIG. 13 is a schematic diagram of an actuator using the liquid crystal composition of the embodiment. FIG. 14 (a) is a photograph of a state in which a voltage is not applied to the actuator manufactured in the embodiment, and FIG. 14 (b) is a photograph of a state in which a voltage is applied.

[Liquid crystal composition]
The liquid crystal composition of the present embodiment contains a first compound represented by the following general formula (1) and a second compound represented by the following general formula (2). Both the first compound and the second compound are phenyldioxane-based liquid crystal compounds (liquid crystal molecules), and are oriented in a specific temperature range to express a liquid crystal phase.

The first compound is not particularly limited as long as it is a compound represented by the general formula (1). The first compound may be one kind of compound or may contain two or more kinds of compounds.

In the general formula (1)
R ¹ is an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms and having a double bond at the terminal, an alkoxy group having 1 to 3 carbon atoms, or an alkoxyalkyl group having 2 to 3 carbon atoms. ,
A ¹¹ is -COO- or -CF ₂ O-, and A ¹² is a single bond.
B ¹¹ is a fluorine atom, B ¹² is a hydrogen atom, B ¹³ is a fluorine atom, and so on.
D ¹ may be a fluorine atom, -CF ₃ or -OCF ₃ .

In R ¹ of the general formula (1), the alkyl group having 1 to 4 carbon atoms may be, for example, a methyl group, an ethyl group, a propyl group, or an n-butyl group. The alkenyl group having 2 to 4 carbon atoms and having a double bond at the terminal may be, for example, a vinyl group, an allyl group, or a 3-butenyl group. The alkoxy group having 1 to 3 carbon atoms may be, for example, a methoxy group, an ethoxy group, or a propoxy group. The alkoxyalkyl group having 2 to 3 carbon atoms may be a methoxymethyl group, a 2-methoxyethyl group, or an ethoxymethyl group.

Specific first compounds include, for example, 2,3', 4', 5'-tetrafluoro- (1,1'-biphenyl) -4-yl 2,6-difluoro-4- (5-propyl-). 1,3-dioxane-2-yl) benzoate, 2,3', 5'-trifluoro-4'-(trifluoromethyl)-(1,1'-biphenyl) -4-yl 2,6-difluoro- 4- (5-propyl-1,3-dioxane-2-yl) benzoate, 2,3', 4', 5'-tetrafluoro- (1,1'-biphenyl) -4-yl 2,6-difluoro -4- (5-Ethyl-1,3-dioxane-2-yl) benzoate, 2,3', 4', 5'-tetrafluoro- (1,1'-biphenyl) -4-yl 2,6-yl Difluoro-4- (5-butyl-1,3-dioxane-2-yl) benzoate, 2,3', 4', 5'-tetrafluoro- (1,1'-biphenyl) -4-yl 2,6 -Difluoro-4- (5-allyl-1,3-dioxane-2-yl) benzoate, and 2- (4- (difluoro ((2,3', 4', 5', 5'-tetrafluoro-)-(1,1) '-Biphenyl) -4-yl) oxy) methyl) -3,5-difluorophenyl) -5-propyl-1,3-dioxane and the like can be mentioned.

Among them, the first compound is a compound represented by the following chemical formula (3), that is, 2,3', 4', 5'-tetrafluoro- (1,1'-biphenyl) -4-yl 2,6-yl. Difluoro-4- (5-propyl-1,3-dioxane-2-yl) benzoate is preferred. The first compound represented by the chemical formula (3) is relatively easy to synthesize, and when the first compound represented by the chemical formula (3) is used, the temperature range in which the liquid crystal phase of the liquid crystal composition is expressed is set to room temperature. It becomes easier to adjust in the vicinity.

In the first compound represented by the chemical formula (3), R ¹ is a propyl group (an alkyl group having 3 carbon atoms) in the general formula (1).
A ¹¹ is -COO-, A ¹² is a single bond,
B ¹¹ is a fluorine atom, B ¹² is a hydrogen atom, B ¹³ is a fluorine atom, and so on.
D ¹ is a fluorine atom.

The second compound is not particularly limited as long as it is a compound represented by the general formula (2). The second compound may be one kind of compound or may contain two or more kinds of compounds.

In the general formula (2)
^R2 is an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms and having a double bond at the terminal, an alkoxy group having 1 to 3 carbon atoms, or an alkoxyalkyl group having 2 to 3 carbon atoms. ,
A ² is -COO- or -CF ₂ O-,
Both B ²¹ and B ²² may be fluorine atoms.

In R ² of the general formula (2), the alkyl group having 1 to 4 carbon atoms may be, for example, a methyl group, an ethyl group, a propyl group, or an n-butyl group. The alkenyl group having 2 to 4 carbon atoms and having a double bond at the terminal may be, for example, a vinyl group, an allyl group, or a 3-butenyl group. The alkoxy group having 1 to 3 carbon atoms may be, for example, a methoxy group, an ethoxy group, or a propoxy group. The alkoxyalkyl group having 2 to 3 carbon atoms may be a methoxymethyl group, a 2-methoxyethyl group, or an ethoxymethyl group.

Specific examples of the second compound include 4-cyano-3,5-difluorophenyl 2,6-difluoro-4- (5-propyl-1,3-dioxane-2-yl) benzoate and 4-cyano-. 3,5-Difluorophenyl 2,6-difluoro-4- (5-ethyl-1,3-dioxane-2-yl) benzoate, 4-cyano-3,5-difluorophenyl 2,6-difluoro-4- (5-ethyl-1,3-dioxan-2-yl) benzoate 5-Butyl-1,3-dioxane-2-yl) benzoate, 4-cyano-3,5-difluorophenyl 2,6-difluoro-4- (5-allyl-1,3-dioxan-2-yl) benzoate , And 4-((2,6-difluoro-4- (5-propyl-1,3-dioxane-2-yl) phenyl) difluoromethoxy) -2,6-difluorobenzonitrile and the like.

Among them, the second compound is a compound represented by the following chemical formula (4), that is, 4-cyano-3,5-difluorophenyl 2,6-difluoro-4- (5-propyl-1,3-dioxane-2). -Il) Benzoate is preferred. The second compound represented by the chemical formula (4) is relatively easy to synthesize, and when the second compound represented by the chemical formula (4) is used, the temperature range in which the liquid crystal phase of the liquid crystal composition is expressed is set to room temperature. It becomes easier to adjust in the vicinity.

In the second compound represented by the chemical formula (4), ^R2 is a propyl group (an alkyl group having 3 carbon atoms) in the general formula (2).
A ² is -COO-
Both B ²¹ and B ²² are fluorine atoms.

As shown in FIGS. 2 and 3, the first compound (sample 1 in the examples described later) exhibits a very high dielectric constant of 10,000 or more in a temperature region exceeding 40 ° C. It is presumed that this is due to the fact that the first compound expresses a unique liquid crystal phase (M3 phase shown in FIG. 1) in this temperature range. The M3 phase is a polar nematic phase, and there is a ferroelectric orientation order in which dipole moments parallel to the long axis of the liquid crystal molecule are locally aligned in one direction, which causes the development of high permittivity. It is presumed that there is. On the other hand, since the first compound (sample 1) crystallizes near room temperature, the dielectric constant is low near room temperature. By mixing the second compound with the first compound, the present inventors suppressed crystallization at around room temperature (for example, 5 to 40 ° C.), whereby a mixture of the first compound and the second compound was suppressed. Was found to show a high dielectric constant near room temperature. As described above, the liquid crystal composition of the present embodiment containing the first compound and the second compound has a high dielectric constant with suppressed crystallization near room temperature where various electronic devices are expected to be driven.

It is presumed that the reason why the liquid crystal composition of the present embodiment shows a high dielectric constant near room temperature is that the M3 phase, which is the above-mentioned peculiar liquid crystal phase, is expressed near room temperature. As shown in FIGS. 2 and 3, the ratio of the blending amount of the first compound to the total blending amount of the first compound and the second compound (hereinafter, appropriately referred to as “ratio of the first compound in the liquid crystal mixture””. ) Decreases, the temperature range showing a high dielectric constant shifts to the low temperature side. Similarly, as shown in FIG. 1, as the proportion of the first compound in the liquid crystal mixture decreases, the temperature range in which the M3 phase develops also shifts to the low temperature side. As can be understood from FIGS. 1 and 2, the range showing a very high dielectric constant of 10,000 or more is almost the same as the range in which the M3 phase is expressed.

The reason why the temperature range in which the M3 phase is expressed shifts to the low temperature side as the proportion of the first compound in the liquid crystal mixture decreases is not clear, but it is presumed as follows. As shown in FIG. 1 and Table 1 of Examples described later, the second compound (Sample 9 in Examples described later) does not express the M3 phase by itself, but transitions from the M2 phase to the crystalline phase near room temperature (). Crystallize). However, originally, the second compound has the potential to express the M3 phase on the low temperature side of the temperature range in which the M2 phase is expressed, and the reason why the M3 phase is not expressed is that the molecular motion is suppressed by crystallization. It is presumed to be. The temperature range in which the second compound is presumed to express the M3 phase is lower than the temperature range in which the first compound expresses the M3 phase. In the liquid crystal composition of the present embodiment, by mixing the first compound, which is a foreign substance, with the second compound, crystallization of the second compound is prevented at around room temperature, and the M3 phase of the second compound can be expressed. It is presumed that it became. Further, it is presumed that the crystallization of the first compound at around room temperature was prevented by mixing the second compound, which is a foreign substance, with the first compound also in the first compound. Then, as shown in FIG. 1, as the proportion of the first compound in the liquid crystal mixture decreases, that is, as the proportion of the second compound increases, the temperature range in which the M3 phase is expressed is M3 for the second compound. It is presumed that the temperature range for expressing the phase is approached and the temperature shifts to the lower temperature side. It should be noted that these mechanisms are speculative and do not limit the present invention in any way.

Further, as shown in FIG. 1, in the liquid crystal composition of the present embodiment, a liquid crystal phase (M4 phase) different from the M3 phase may be further expressed on the low temperature side of the M3 phase. Even in the temperature range in which the M4 phase appears, the liquid crystal composition of the present embodiment exhibits a high dielectric constant of, for example, 1,000 or more, or 2,000 or more.

As described above, the liquid crystal composition of the present embodiment suppresses crystallization at around room temperature where various electronic devices are expected to be driven, and develops a liquid crystal phase. Unlike the crystalline phase, the liquid crystal phase has flexibility and fluidity. Therefore, the liquid crystal composition of the present embodiment is suitable for electronic devices that require flexibility and fluidity when driven. For example, the liquid crystal composition of the present embodiment can easily follow the deformation of a device that accompanies the deformation of an actuator or the like. Further, the liquid crystal composition of the present embodiment can also be applied to a device such as a display that utilizes the fluidity of the liquid crystal composition at the time of driving.

In the liquid crystal composition, the ratio between the blending amount of the first compound and the blending amount of the second compound is not particularly limited. For example, the proportion of the first compound in the liquid crystal mixture may be 7% by weight to 93% by weight, or 10% by weight to 90% by weight. By setting the ratio of the first compound in the liquid crystal mixture within the above range, the liquid crystal composition becomes more difficult to crystallize near room temperature.

As shown in FIGS. 2 to 4, the liquid crystal composition of the present embodiment has a temperature range showing a high dielectric constant by adjusting the ratio between the blending amount of the first compound and the blending amount of the second compound. Can be controlled. This makes it possible to design a desired liquid crystal composition according to the temperature range in which the electronic device in which the liquid crystal composition is used is expected to be driven. For example, by setting the ratio of the first compound in the liquid crystal mixture to 17% by weight to 93% by weight, in the entire temperature range (for example, 5 to 40 ° C.) near room temperature where various electronic devices are expected to be driven. A high dielectric constant (for example, a relative permittivity of 1,000 or more) can be obtained. Further, for example, in the case of an electronic device used in a temperature-controlled room, the temperature range in which the electronic device is driven can be specified in a narrower range. In such applications, the proportion of the first compound in the liquid crystal mixture is 20% by weight to 90% by weight, so that a higher dielectric constant (for example, a relative permittivity of 3,000) is used at 15 ° C to 30 ° C. The above) can be obtained. Further, by setting the ratio of the first compound in the liquid crystal mixture to 30% by weight to 75% by weight, a higher dielectric constant (for example, a relative dielectric constant of 10,000 or more) can be obtained at 25 ° C to 35 ° C. be able to.

As shown in FIG. 1, the liquid crystal composition of the present embodiment has a specific liquid crystal phase (for example, a specific liquid crystal phase) exhibiting a high dielectric constant by adjusting the ratio between the blending amount of the first compound and the blending amount of the second compound. , M3 phase and / or M4 phase) can be controlled. This makes it possible to design the composition of the liquid crystal composition according to the temperature range in which the electronic device in which the liquid crystal composition is used is expected to be driven. For example, when the temperature range in which the electronic device is driven can be specified in a narrower range as described above, the proportion of the first compound in the liquid crystal mixture is 27% by weight to 93% by weight, or 30% by weight or more. By setting the content to 90% by weight, an M3 phase or an M4 phase having a high dielectric constant can be expressed in a temperature range of 5 to 35 ° C. Further, by setting the ratio of the first compound in the liquid crystal mixture to 17% by weight to 33% by weight or 20% by weight to 30% by weight, the M3 phase having a higher dielectric constant in the temperature range of 15 to 25 ° C. can be obtained. Can be expressed.

The method for synthesizing the first compound and the second compound is not particularly limited, and may be synthesized by using a known method. For example, the first compound represented by the chemical formula (3) can be synthesized according to the synthetic scheme shown in FIG. 5, and the second compound represented by the chemical formula (4) can be synthesized according to the synthetic scheme shown in FIG.

The synthesis scheme of the first compound shown in FIG. 5 will be described. First, 2-propyl-1,3-propanediol represented by the formula (a) is reacted with 3,5-difluorobenzaldehyde represented by the formula (b) in the presence of an acid catalyst to react with the formula (c). 2- (3,5-difluorophenyl) -5-propyl-1,3-dioxane (hereinafter referred to as compound (c)) represented by) is synthesized. Next, n-butyllithium is allowed to act on the compound (c) at about −50 ° C. to form a lithiodide represented by the formula (d), and further reacted with carbon dioxide to be represented by the formula (e). 2,6-Difluoro-4- (5-propyl-1,3-dioxane-2-yl) benzoic acid (hereinafter referred to as compound (e)) is obtained. 2,3', represented by formula (f), in the presence of 4-dimethylaminopyridine (DMAP) and 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide (EDCI) in compound (e). By reacting 4', 5'-tetrafluorobiphenyl-4-ol, the first compound represented by the chemical formula (3) is obtained.

The synthesis scheme of the second compound shown in FIG. 6 will be described. First, compound (e) is synthesized according to the synthesis scheme shown in FIG. 5 described above. Next, the compound (e) is reacted with 2,6-difluoro-4-hydroxybenzonitrile represented by the formula (g) in the presence of DMAP and EDCI, and the compound (e) is represented by the chemical formula (4). Two compounds are obtained.

The liquid crystal composition of the present embodiment may be composed of only two kinds of compounds, the first compound and the second compound, and is also represented by the first compound represented by the chemical formula (3) and the chemical formula (4). It may be composed of only two components of the second compound to be made. Further, the liquid crystal compound contained in the liquid crystal composition may be composed of only two kinds of the first compound and the second compound, and the first compound represented by the chemical formula (3) and the chemical formula (4). ) May be composed of only two components of the second compound.

The liquid crystal composition of the present embodiment may further contain a third compound represented by the following general formula (5) in addition to the first compound and the second compound.

The third compound is a phenyldioxane-based compound like the first compound and the second compound, but unlike the first compound and the second compound, it does not express a liquid crystal phase by itself. That is, the third compound is not a liquid crystal compound.

In the general formula (5)
R ⁵ is an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms and having a double bond at the terminal, an alkoxy group having 1 to 3 carbon atoms, or an alkoxyalkyl group having 2 to 3 carbon atoms. can be,
A ⁵ is -COO- or -CF ₂ O-,
Both B ⁵¹ and B ⁵² are fluorine atoms,
D ⁵ may be a fluorine atom, -CF ₃ or -OCF ₃ .

In R5 of the general formula ( ⁵ ), the alkyl group having 1 to 4 carbon atoms may be, for example, a methyl group, an ethyl group, a propyl group, or an n-butyl group. The alkenyl group having 2 to 4 carbon atoms and having a double bond at the terminal may be, for example, a vinyl group, an allyl group, or a 3-butenyl group. The alkoxy group having 1 to 3 carbon atoms may be, for example, a methoxy group, an ethoxy group, or a propoxy group. The alkoxyalkyl group having 2 to 3 carbon atoms may be a methoxymethyl group, a 2-methoxyethyl group, or an ethoxymethyl group.

Specific examples of the third compound include 3,4,5-trifluorophenyl 2,6-difluoro-4- (5-propyl-1,3-dioxane-2-yl) benzoate and 3,5-difluoro. -4- (Trifluoromethyl) phenyl 2,6-difluoro-4- (5-ethyl-1,3-dioxane-2-yl) benzoate, 3,4,5-trifluorophenyl 2,6-difluoro-4 -(5-Ethyl-1,3-dioxane-2-yl) benzoate, 3,4,5-trifluorophenyl 2,6-difluoro-4- (5-butyl-1,3-dioxane-2-yl) Benzoate, 3,4,5-trifluorophenyl 2,6-difluoro-4- (5-allyl-1,3-dioxane-2-yl) benzoate, and 2- (4- (difluoro (3,4,5)) -Trifluorophenyl) methoxy) -3,5-difluorophenyl) 5-propyl-1,3-dioxane can be mentioned.

Among them, the third compound is a compound represented by the following chemical formula (6), that is, 3,4,5-trifluorophenyl 2,6-difluoro-4- (5-propyl-1,3-dioxane-2-). Il) Benzoate is preferred. The first compound represented by the chemical formula (6) is relatively easy to synthesize, and when the third compound represented by the chemical formula (6) is used, the temperature range in which the liquid crystal phase of the liquid crystal composition is expressed is set to room temperature. It becomes easier to adjust in the vicinity.

In the general formula (5), the third compound represented by the chemical formula (6) has a propyl group (alkyl group having ³ carbon atoms) and R5.
A ⁵ is -COO-,
Both B ⁵¹ and B ⁵² are fluorine atoms,
D ⁵ is a fluorine atom.

The present inventor has found that the temperature range in which the M3 phase exhibiting a high dielectric constant can be further shifted to the lower temperature side by further blending the third compound with the first compound and the second compound. This makes it easier to adjust the temperature range showing a high dielectric constant to around room temperature. In the examples described later, the compounding amount of the third compound was changed and added to the first compound and the second compound, and the phase transition temperature of the obtained compounding (sample) was measured. The results are shown in FIG. In addition, in the examples described later, the permittivity (ε _r ': the real part of the relative permittivity) for each measurement temperature of each sample was also measured. The results are shown in FIG. Further, based on the data shown in FIG. 9, the relationship between the temperature of each sample and the permittivity (εr': the real part of the relative permittivity) is shown in FIG. As shown in FIG. 8, the ratio of the compounding amount of the third compound to the total compounding amount of the first compound, the second compound, and the third compound (hereinafter, appropriately referred to as “ratio of the third compound in the compound”). As the value (described) increases, the temperature range in which the M3 phase develops shifts to the lower temperature side. Similarly, as shown in FIGS. 9 and 10, as the proportion of the third compound in the formulation increases, the temperature range showing a high dielectric constant shifts to the low temperature side. As can be understood from FIGS. 8 and 9, even in the ternary liquid crystal composition containing the third compound, the M3 phase is expressed in the range showing a very high dielectric constant of 10,000 or more. It is almost in line with the range.

The reason why the temperature range in which the M3 phase is expressed shifts to the low temperature side as the proportion of the third compound in the formulation increases is not clear, but it is presumed as follows. Since the third compound is the same phenyldioxane-based compound as the first compound and the second compound, it is easy to uniformly mix with the first compound and the second compound. On the other hand, since the third compound itself is not a liquid crystal compound, it inhibits the molecular arrangement of the first compound and the second compound for forming the M3 phase (liquid crystal phase). Therefore, it is presumed that the M3 phase is expressed on the lower temperature side in the three-component liquid crystal composition containing the third compound as compared with the two-component liquid crystal composition containing no third compound. It should be noted that these mechanisms are speculative and do not limit the present invention in any way.

Further, as shown in FIG. 8, even in a three-component liquid crystal composition containing a third compound, a liquid crystal phase (M4 phase) different from the M3 phase may be further expressed on the low temperature side of the M3 phase. be. Even in the temperature range in which the M4 phase appears, the liquid crystal composition of the present embodiment exhibits a high dielectric constant of, for example, 1,000 or more, or 2,000 or more.

In the three-component liquid crystal composition containing the third compound, the ratio of the third compound in the formulation is not particularly limited. As shown in FIGS. 9 to 11, the liquid crystal composition of the present embodiment can control the temperature range showing a high dielectric constant by adjusting the ratio of the third compound in the formulation. This makes it possible to design a desired liquid crystal composition according to the temperature range in which an electronic device such as an actuator using the liquid crystal composition is expected to be driven.

For example, as shown in FIG. 9, by setting the proportion of the third compound in the formulation to be more than 0% by weight and 50% by weight or less, it is compared with the two-component liquid crystal composition containing no third compound. As a result, crystallization at around room temperature (for example, 5 to 40 ° C.) can be suppressed as in the case of the two-component liquid crystal composition, while shifting the temperature range in which the M3 phase develops to the low temperature side. Further, by setting the ratio of the third compound in the formulation to 7% by weight to 18% by weight, preferably 10% by weight to 15% by weight, the entire temperature range near room temperature where various electronic devices are expected to be driven is assumed. At (for example, 5 to 40 ° C.), a high dielectric constant (for example, a relative permittivity of 1,000 or more) can be obtained. Further, for example, in the case of an electronic device used in a temperature-controlled room, the temperature range in which the electronic device is driven can be specified in a narrower range. In such applications, the proportion of the third compound in the formulation is 7% to 23% by weight, preferably 10% to 20% by weight, so that the dielectric constant is higher at 15 ° C to 30 ° C. For example, a relative permittivity of 3,000 or more) can be obtained. Further, by setting the proportion of the third compound in the formulation to be more than 0% by weight and 18% by weight or less, preferably 15% by weight or less, the dielectric constant is even higher (for example, at 25 ° C to 35 ° C). A relative permittivity of 10,000 or more) can be obtained.

Further, as shown in FIG. 8, the liquid crystal composition of the present embodiment has a specific liquid crystal phase (for example, M3 phase and / or M4 phase) showing a high dielectric constant by adjusting the ratio of the third compound. The temperature range in which it develops can be controlled. This makes it possible to design the composition of the liquid crystal composition according to the temperature range in which the electronic device in which the liquid crystal composition is used is expected to be driven. For example, when the temperature range in which the electronic device is driven can be specified in a narrower range as described above, the proportion of the third compound is more than 0% by weight and 18% by weight or less, preferably 15% by weight. By the following, it is possible to express the M3 phase or the M4 phase having a high dielectric constant in the temperature range of 5 to 35 ° C. Further, by setting the ratio of the third compound in the formulation to 7% by weight to 35% by weight, preferably 10% by weight to 33% by weight, the M3 phase having a higher dielectric constant in the temperature range of 15 to 25 ° C. can be obtained. Can be expressed.

The method for synthesizing the third compound is not particularly limited, and may be synthesized using a known method. For example, the third compound represented by the chemical formula (6) can be synthesized according to the synthesis scheme shown in FIG. First, compound (e) is synthesized according to the synthesis scheme shown in FIG. 5 described above. Next, the compound (e) is reacted with 3,4,5-trifluorophenol represented by the formula (h) in the presence of DMAP and EDCI, and the third compound represented by the chemical formula (6) is reacted. Is obtained.

The liquid crystal composition of the present embodiment may be composed of only three kinds of compounds, the first compound, the second compound, and the third compound, and the first compound represented by the chemical formula (3) and the chemical formula. It may be composed of only three components of the second compound represented by (4) and the third compound represented by the chemical formula (6).

When the liquid crystal composition of the present embodiment does not contain the third compound, the total blending amount of the first compound and the second compound in the liquid crystal composition of the present embodiment is, for example, 50% by weight or more and 80% by weight or more. , 90% by weight or more, or 98% by weight or more. When the liquid crystal composition of the present embodiment contains the third compound, the total blending amount of the first compound, the second compound, and the third compound in the liquid crystal composition of the present embodiment is, for example, 50% by weight. As mentioned above, it may be 80% by weight or more, 90% by weight or more, or 98% by weight or more.

The liquid crystal composition of the present embodiment may further contain a liquid crystal compound different from the first compound and the second compound as long as the effects of the present embodiment are exhibited. Further, a known additive other than the liquid crystal compound, for example, an antioxidant, an ultraviolet absorber, a surfactant and the like may be contained. Further, in order to facilitate immobilization of the liquid crystal composition on an arbitrary support, an additional compound, a dispersion medium, or the like for elastomerizing or gelling the liquid crystal composition may be further contained.

The liquid crystal composition of the present embodiment can be prepared by mixing the first compound, the second compound, and if necessary, the third compound and other additives by a known method. For example, the first compound, the second compound, and, if necessary, the third compound may be dissolved in a solvent and mixed, and then the solvent may be removed to prepare a liquid crystal composition. Further, the liquid crystal composition may be prepared by directly mixing the first compound, the second compound, and, if necessary, the third compound without using a solvent. At this time, the first compound and the second compound may be in a crystalline (solid) state, a liquid crystal state, or a liquid state. The third compound may be in a crystalline (solid) state or in a liquid state. Further, the first compound, the second compound, and, if necessary, the third compound are mixed (primary mixing), then the mixture is heated, and the heated mixture is further mixed (secondary mixing) to obtain a liquid crystal display. The composition may be prepared. Further, in order to facilitate immobilization of the liquid crystal composition on an arbitrary support, the liquid crystal composition may be made into an elastomer, gelled, or the like by an additional compound, a dispersion medium, or the like, and / or by an additional treatment.

[Actuator]
The liquid crystal composition of the present embodiment described above can be applied to various electronic devices. As an example, FIG. 13 shows an actuator (driving device) 100 using a liquid crystal composition. The actuator 100 has a liquid crystal composition 10 of the present embodiment and a pair of spiral (coil-shaped) electrodes 20 embedded (coated) in the liquid crystal composition 10.

The actuator 100 can be manufactured by preparing a pair of

coils

20a and 20b as electrodes 20 and filling the spaces between the coils with the liquid crystal composition 10 by a known method. The

coils

20a and 20b may be manufactured by winding a conducting wire in a spiral shape. Alternatively, a resin spiral structure may be produced by a 3D printer, coated with a plating film, and made conductive. In this case, the coils 20a and the coils 20b are overlapped and arranged in a double spiral shape so that the windings do not come into contact with each other as shown in FIG. A spacer (not shown) may be further provided between the

coils

20a and 20b in order to prevent short circuits between the coils. The spacer may be, for example, a spiral structure of an insulating resin manufactured by a 3D printer. By twisting the

coils

20a and 20b into the spiral spacer and integrating them, a short circuit between the spiral coils can be prevented. The actuator 100 can be formed by covering with the liquid crystal composition 10 so as to fill the gap between the

coils

20a and 20b (the gap between the windings of the coil).

The actuator 100 expands and contracts in the direction of the arrow shown in FIG. 13 by applying a voltage between the electrodes in the temperature range in which the liquid crystal composition 10 expresses the liquid crystal phase. This is because the liquid crystal composition 10 has a high dielectric constant, so that a large electrostatic force is generated by applying a voltage between the

coils

20a and 20b sandwiching the liquid crystal composition 10. If the dielectric constant of the liquid crystal composition 10 is high, the electrostatic force between the electrodes becomes large, and the drive range of the actuator 100 can be increased. As described above, the liquid crystal composition 10 of the present embodiment has a temperature range in which a specific liquid crystal phase (for example, M3 phase and / or M4 phase) exhibiting a high dielectric constant is expressed near room temperature by adjusting the composition. Can be adjusted to. This makes it possible to realize the actuator 100 having a large driving force near room temperature.

Next, examples of the present invention will be described together with comparative examples. The present invention is not limited to these Examples and Comparative Examples, and can be appropriately modified within the scope of the technical idea described in the claims.

[Liquid crystal composition]
<Preparation of liquid crystal composition 1>
A two-component liquid crystal composition (Samples 1 to 9) containing the first compound and the second compound was prepared by the method described below.
[Sample 1]
The first compound represented by the chemical formula (3) was synthesized according to the synthesis scheme shown in FIG. 5, and the first compound was used as sample 1. That is, the ratio of the first compound in the liquid crystal mixture of sample 1 was 100% by weight.

[Sample 2]
The first compound represented by the chemical formula (3) was synthesized according to the synthetic scheme shown in FIG. 5, and the second compound represented by the chemical formula (4) was synthesized according to the synthetic scheme shown in FIG. A solution was prepared by dissolving the first compound represented by the chemical formula (3) and the second compound represented by the chemical formula (4) in a solvent (chloroform). The total amount of the first compound and the second compound in the solution was 1% by weight. The proportion of the first compound in the liquid crystal mixture was 90% by weight. Next, the solvent was removed by vacuum drying to obtain Sample 2 (liquid crystal composition).

[Samples 3-8]
In Samples 3 to 8, the proportions of the first compound in the liquid crystal mixture were 75% by weight, 50% by weight, 40% by weight, 30% by weight, 20% by weight, and 10% by weight, respectively. Except for this, Samples 3 to 8 (liquid crystal composition) were obtained by the same method as in Sample 2.

[Sample 9]
The second compound represented by the chemical formula (4) was synthesized according to the synthesis scheme shown in FIG. 6, and the second compound was used as sample 9. That is, in the sample 9, the ratio of the first compound in the liquid crystal mixture was 0% by weight.

Samples 2 to 8 correspond to Examples, and

Samples

1 and 9 correspond to Comparative Examples.

<Evaluation 1 of liquid crystal composition>
(1) Evaluation of liquid crystal property The liquid crystal property of Samples 1 to 9 was evaluated by differential scanning calorimetry (DSC) and observation with a polarizing microscope (POM).

(A) Differential scanning calorimetry (DSC)
About 5 mg of the sample was filled in a sample pan made of aluminum and installed in a differential scanning calorimeter (DSC8000 manufactured by PerkinElmer). Using an empty aluminum sample pan as a reference, the temperature was raised to 90 ° C., then cooled to 0 ° C. at 5 ° C./min, and the differential scanning calorimetry during the cooling process was measured.

(B) Observation with a polarizing microscope A polarizing microscope (BX53 manufactured by OLYMPUS) controls the temperature of a sample injected into a glass cell by a hot stage for a microscope (Mettler Toledo Co., Ltd., HS82) equipped with a cooling mechanism using liquid nitrogen. ) Was used for observation under a cross Nicol.

Table 1 and FIG. 1 show the liquid crystal phase confirmed by differential scanning calorimetry and polarization microscope observation, and the derived phase transition temperature and crystallization temperature. Further, FIGS. 7A to 7D show polarizing micrographs of Sample 4 at 80 ° C., 60 ° C., 30 ° C., and 10 ° C., respectively.

Three types of liquid crystal phases were confirmed in the cooling process of samples 1-8. These liquid crystal phases are referred to as M1 phase, M2 phase and M3 phase from the high temperature side. In Samples 3 to 6, another liquid crystal phase was confirmed on the lower temperature side of the M3 phase. This liquid crystal phase is referred to as M4 phase. Therefore, FIGS. 7 (a) to 7 (d) are polarizing microscope photographs of the M1 phase, the M2 phase, the M3 phase, and the M4 phase, respectively. Further, in sample 9, M1 phase and M2 phase were confirmed, but M3 phase was not confirmed. From the observation with a polarizing microscope, it is inferred that the M1 phase is a nematic phase, the M2 phase is a smectic phase, the M3 phase is a nematic phase, and the M4 phase is a smectic phase. In a general phase transition, a higher-order ordered phase appears when the temperature becomes low, but this order is reversed in the transition from the M2 phase to the M3 phase. That is, the smectic phase (M2 phase) is relocated to the nematic phase (M3 phase), which is a lower order phase, on the low temperature side. Therefore, the M3 phase is presumed to be a reentrant nematic phase. Within the measurement temperature range, the sample 1 composed of only the first compound and the sample 9 composed of only the second compound crystallized and the crystal phase was confirmed, but the crystal phase was not confirmed in the samples 2 to 8. It is presumed that the crystal phases of Samples 2 to 8 exist below 0 ° C., which is outside the measurement temperature range. Further, within the measurement temperature range, isotropic phases (liquids) of all the samples 1 to 9 are not confirmed, and it is presumed that they exist in a temperature range exceeding 90 ° C., which is outside the measurement temperature range.

(2) Measurement of dielectric constant A sample is injected into a cell having an ITO electrode with an area of 10 mm × 10 mm and a gap of 10 μm, and the temperature is controlled by a hot stage for a microscope (METTLER TOLEDO Co., Ltd., HS82) equipped with a cooling mechanism using liquid nitrogen. At the same time, the temperature dependence of Cp (equivalent parallel capacitance) at 100 Hz was measured using a frequency characteristic analyzer (FREQUENCY RESPONSE ANALYZER: FRA) (FRA51615, manufactured by NF Circuit Design Block Co., Ltd.). The measured voltage was DC: 0V and AC: 3.6Vpp.

The permittivity (ε _r ': real part of the relative permittivity) of Samples 1 to 9 at 100 Hz was determined for each measurement temperature by the following relational expression. The results are shown in the table of FIG.

ε _r '= (t × Cp) / (A × ε ₀ )

ε _r ': Relative permittivity real part t: Sample thickness (cell gap in this example)
Cp: Equivalent parallel capacitance A: Electrode area ε ₀ : Permittivity of vacuum

Based on the data shown in FIG. 2, the relationship between the temperature and the permittivity (ε _r ': the real part of the relative permittivity) of each of the samples 1 to 9 is shown in FIG. Further, FIG. 4 shows the relationship between the ratio (% by weight) of the first compound in the liquid crystal mixture and the permittivity (ε _r ': the real part of the relative permittivity) for each measurement temperature.

(3) Discussion As shown in FIGS. 2 to 3, the samples 2 to 8 containing the first compound and the second compound have a liquid crystal phase (M2 phase, M3) at around room temperature (for example, 5 ° C to 40 ° C). Phase, M4 phase) was expressed and did not crystallize. On the other hand, the sample 1 containing only the first compound and the sample 9 containing only the second compound crystallized at around room temperature.

Further, the samples 2 to 8 containing the first compound and the second compound showed a high dielectric constant (for example, a relative permittivity of 1,000 or more) near room temperature (for example, 5 ° C to 40 ° C). On the other hand, the sample 1 containing only the first compound showed a high dielectric constant in a high temperature region exceeding 40 ° C., but had a low dielectric constant near room temperature (relative permittivity 3 to 4). Further, the sample 9 containing only the second compound also had a low dielectric constant near room temperature (relative permittivity 3), and further, the relative permittivity was less than 1,000 over the entire measurement temperature range.

As shown in FIGS. 2 and 3, as the proportion of the first compound in the liquid crystal mixture decreased, the temperature range showing a high dielectric constant shifted to the low temperature side. By adjusting the proportion of the first compound in the liquid crystal mixture, the temperature range showing a high dielectric constant can be controlled. As shown in FIG. 4, when the ratio of the first compound in the liquid crystal mixture is 17% by weight to 93% by weight, the relative permittivity is as high as 1,000 or more in the entire temperature range of 5 to 40 ° C. there were. As shown in FIG. 2, when the ratio of the first compound in the liquid crystal mixture is 20% by weight to 90% by weight, the relative permittivity is a higher value of 3,000 or more in the entire temperature range of 15 to 30 ° C. Met. Further, when the ratio of the first compound in the liquid crystal mixture was 30% by weight to 75% by weight, the relative permittivity was even higher at 10,000 or more in the entire temperature range of 25 to 35 ° C.

As shown in FIG. 1, as the proportion of the first compound in the liquid crystal mixture decreased, the temperature range in which the M3 phase was expressed also shifted to the low temperature side. As can be seen from FIGS. 1 and 2, the range showing a very high dielectric constant of 10,000 or more was almost the same as the range in which the M3 phase was expressed. Further, even in the temperature range in which the M4 phase appears, the liquid crystal composition showed a high dielectric constant of, for example, 1,000 or more or 2,000 or more. By adjusting the proportion of the first compound in the liquid crystal mixture, the temperature range in which a specific liquid crystal phase showing a high dielectric constant (for example, M3 phase and / or M4 phase) appears can be controlled. As shown in FIG. 1, when the proportion of the first compound in the liquid crystal mixture was 27% by weight to 93% by weight, the M3 phase or the M4 phase was expressed in the entire temperature range of 5 to 35 ° C. Further, when the ratio of the first compound in the liquid crystal mixture was 17% by weight to 33% by weight, the M3 phase was expressed in the entire temperature range of 15 to 25 ° C.

<Preparation of liquid crystal composition 2>
A three-component liquid crystal composition (samples 10 to 15) containing the first compound, the second compound, and the third compound was prepared by the method described below.

[Sample 10]
The third compound represented by the chemical formula (6) was synthesized according to the synthesis scheme shown in FIG. 12 and used as a sample 10. That is, the sample 10 is a sample containing only the third compound, which does not contain the first compound and the second compound.

[Sample 11]
A three-component liquid crystal composition was prepared in which the ratio of the third compound in the compound composed of the first compound, the second compound and the third compound was 50% by weight. The weight ratio of the first compound to the second compound was (first compound) :( second compound) = 50:50.

First, the first compound represented by the chemical formula (3) is synthesized according to the synthetic scheme shown in FIG. 5, and the second compound represented by the chemical formula (4) is synthesized according to the synthetic scheme shown in FIG. The third compound represented by the chemical formula (6) was synthesized according to the synthesis scheme. The synthesized first compound, second compound, and third compound were dissolved in a solvent (chloroform) at the above-mentioned weight ratio to prepare a solution. The total blending amount of the first compound, the second compound and the third compound in the solution was 1% by weight. Next, the solvent was removed by vacuum drying to obtain Sample 11 (liquid crystal composition).

[Samples 12 to 15]
In Samples 12 to 15, the proportions of the third compound in the formulation were 33% by weight, 20% by weight, 15% by weight, and 10% by weight, respectively. Except for this, Samples 12 to 15 (liquid crystal composition) were prepared by the same method as in Sample 11.

Samples 11 to 15 correspond to Examples, and Sample 10 corresponds to Comparative Examples.

<Evaluation of liquid crystal composition 2>
(1) Evaluation of liquid crystal property The liquid crystal property of the samples 10 to 15 was evaluated by the same evaluation method as the above-mentioned samples 1 to 9, that is, by differential scanning calorimetry (DSC) and polarization microscope (POM) observation. Tables 2 and 8 show the liquid crystal phase confirmed by differential scanning calorimetry and polarization microscope observation, and the derived phase transition temperature and crystallization temperature. For comparison, the evaluation results of sample 4 are also shown in Table 2 and FIG. In the sample 4, the ratio of the third compound is 0% by weight, and the weight ratio of the first compound to the second compound is (first compound) :( second compound) = 50: 50.

In the cooling process of samples 11 to 15, three types of liquid crystal phase, M1 phase, M2 phase and M3 phase were confirmed as in samples 1 to 8. In the sample 15, the M4 phase was confirmed on the lower temperature side of the M3 phase as in the samples 3 to 6. Within the measurement temperature range, the isotropic phase (liquid) of the samples 11 to 15 is not confirmed, and it is presumed that the sample exists in a temperature range exceeding 90 ° C., which is outside the measurement temperature range. In addition, the crystal phase of Samples 11 to 15 was not confirmed within the measurement temperature range (temperature range of 0 ° C. or higher). It is presumed that the crystal phases of the samples 11 to 15 exist below 0 ° C., which is outside the measurement temperature range. On the other hand, in sample 10 (third compound: 100% by weight), it crystallized from an isotropic phase (liquid phase) at 15 ° C. and did not express a liquid crystal phase. That is, it was confirmed that the third compound was not a liquid crystal compound.

(2) Measurement of Permittivity The permittivity (ε _r ': real part of the relative permittivity) of the samples 11 to 15 was determined for each measurement temperature by the same method as the above-mentioned samples 1 to 9. However, the measured voltages were DC: 0V and AC: 0.1Vpp. The results are shown in the table of FIG. For comparison, the dielectric constant of sample 4 was measured in the same manner, and the results are also shown in the table of FIG.

Based on the data shown in FIG. 9, the relationship between the temperature and the permittivity (ε _r ': the real part of the relative permittivity) of each of the samples 11 to 15 is shown in FIG. Further, FIG. 11 shows the relationship between the ratio (% by weight) of the third compound and the permittivity (ε _r ': the real part of the relative permittivity) for each measurement temperature.

(3) Discussion As shown in FIGS. 8 to 11, in the samples 11 to 15 which are the three-component liquid crystal composition, the temperature range showing the higher dielectric constant is on the lower temperature side as the ratio of the third compound increases. Shifted to. Therefore, by adjusting the proportion of the third compound in the formulation, the temperature range showing a high dielectric constant can be controlled.

As shown in FIGS. 8 to 11, when the proportion of the third compound in the formulation is more than 0% by weight and 50% by weight or less (samples 11 to 15), the liquid crystal phase is developed near room temperature. It was confirmed that the crystals did not crystallize in the temperature range of 0 ° C. or higher. When the proportion of the third compound in the formulation is 7% by weight to 18% by weight (samples 14 and 15), the relative permittivity is as high as 1,000 or more in the entire temperature range of 5 to 40 ° C. rice field. When the proportion of the third compound in the formulation is 7% to 23% by weight (samples 13 to 15), the relative permittivity is higher, 3,000 or more, over the entire temperature range of 15 to 30 ° C. there were. Further, when the proportion of the third compound in the formulation is more than 0% by weight and 18% by weight or less (samples 14 and 15), the relative permittivity is 10,000 in the entire temperature range of 25 to 35 ° C. It was even higher than the above.

As shown in FIG. 8, as the proportion of the third compound increased, the temperature range in which the M3 phase was expressed also shifted to the low temperature side. As can be seen from FIGS. 8 and 9, even in the three-component liquid crystal composition, the range showing a very high dielectric constant of 10,000 or more was almost the same as the range in which the M3 phase was expressed. Further, even in the temperature range in which the M4 phase appears, the liquid crystal composition showed a high dielectric constant of, for example, 1,000 or more or 2,000 or more. Therefore, by adjusting the ratio of the third compound in the formulation, the temperature range in which a specific liquid crystal phase showing a high dielectric constant (for example, M3 phase and / or M4 phase) appears can be controlled.

As shown in FIG. 1, when the proportion of the third compound is more than 0% by weight and 18% by weight or less (samples 14 and 15), the M3 phase or the M4 phase is in the entire temperature range of 5 to 35 ° C. It was expressed. Further, when the ratio of the third compound was 7% by weight to 35% by weight (samples 12 to 15), the M3 phase was expressed in the entire temperature range of 15 to 25 ° C.

[Actuator]
The actuator 100 shown in FIG. 13 was manufactured using a liquid crystal composition having the same composition as that of sample 4.

<Manufacturing of actuator>
First, a resin-made double spiral structure was produced using a 3D printer, and the structure was coated with a plating film to conduct conductivity to obtain an electrode 20 composed of a pair of

coils

20a and 20b. As a spacer (not shown) for preventing a short circuit of the electrode 20, a double spiral structure of an insulating resin was produced using a 3D printer in the same manner as the electrode 20. The double helix electrode 20 was screwed into the double helix spacer to integrate it.

Next, the first compound represented by the chemical formula (3) and the second compound represented by the chemical formula (4) are dissolved in a solvent (chloroform) in the same manner as in the preparation method of the sample 4, and the liquid crystal is liquid crystal. A solution having a mixture concentration of 1% by weight was prepared. The weight ratio of the first compound to the second compound was 50:50. The solvent component was removed from the prepared solution by distillation under reduced pressure and vacuum drying at 50 ° C. in an oven. The obtained liquid crystal composition was heated in an oven at 85 ° C. to obtain an M1 phase, and then injected into the electrode 20 integrated with the spacer with a pipette. As a result, an actuator 100 in which the electrode 20 was coated with the liquid crystal composition 10 was obtained.

<Actuator drive experiment>
At room temperature (around 20 ° C.), the actuator 100 was connected to a power source and a voltage of 200 V was applied. FIG. 14A is a photograph of the actuator in a state where no voltage is applied, and FIG. 14B is a photograph of the actuator in a state where a voltage is applied. The length of the actuator 100 in the state where no voltage was applied was 32.6 mm (see FIG. 14 (a)), but it shrank by about 19% by applying the voltage, and the length of the actuator became 26.3 mm. From this result, it was confirmed that the manufactured actuator can be sufficiently driven at room temperature.

The liquid crystal composition of the present invention can suppress crystallization and exhibit a high dielectric constant near room temperature where various electronic devices are expected to be driven. Therefore, for example, the liquid crystal composition of the present invention can be used for electronic devices such as displays, actuators, capacitors, memories, piezoelectric elements, and inorganic EL members.

Claims

It is a liquid crystal composition
The first compound represented by the following general formula (1) and
A liquid crystal composition containing the second compound represented by the following general formula (2).

In the general formula (1)
R 1 is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxy group having 1 to 11 carbon atoms, or an alkoxyalkyl group having 1 to 11 carbon atoms.
A 11 and A 12 are independently single-bonded, -COO- or -CF 2 O-, respectively.
B 11 , B 12 and B 13 are independently hydrogen atoms or fluorine atoms, respectively.
D 1 is a fluorine atom, -CF 3 or -OCF 3 .

In the general formula (2)
R2 is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxy group having 1 to 11 carbon atoms, or an alkoxyalkyl group having 1 to 11 carbon atoms.
A 2 is a single bond, -COO- or -CF 2 O-,
B 21 and B 22 are independently hydrogen atoms or fluorine atoms, respectively.
The first compound is a compound represented by the following chemical formula (3).
The liquid crystal composition according to claim 1, wherein the second compound is a compound represented by the following chemical formula (4).
The liquid crystal composition according to claim 1 or 2, wherein the ratio of the blending amount of the first compound to the total blending amount of the first compound and the second compound is 7% by weight to 93% by weight.
The liquid crystal composition according to claim 1 or 2, wherein the ratio of the blending amount of the first compound to the total blending amount of the first compound and the second compound is 17% by weight to 93% by weight.
The liquid crystal composition according to claim 1 or 2, wherein the ratio of the blending amount of the first compound to the total blending amount of the first compound and the second compound is 20% by weight to 90% by weight.
The liquid crystal composition according to claim 1 or 2, wherein the ratio of the blending amount of the first compound to the total blending amount of the first compound and the second compound is 30% by weight to 75% by weight.
The liquid crystal composition according to claim 1 or 2, wherein the ratio of the blending amount of the first compound to the total blending amount of the first compound and the second compound is 27% by weight to 93% by weight.
The liquid crystal composition according to claim 1 or 2, wherein the ratio of the blending amount of the first compound to the total blending amount of the first compound and the second compound is 17% by weight to 33% by weight.
The liquid crystal composition according to any one of claims 1 to 8, further comprising a third compound represented by the following general formula (5).

In the general formula (5)
R 5 is an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an alkoxy group having 1 to 11 carbon atoms, or an alkoxyalkyl group having 1 to 11 carbon atoms.
A 5 is a single bond, -COO- or -CF 2 O-,
B 51 and B 52 are independently hydrogen atoms or fluorine atoms, respectively.
D 5 is a fluorine atom, -CF 3 or -OCF 3 .
The liquid crystal composition according to claim 9, wherein the third compound is a compound represented by the following chemical formula (6).
The liquid crystal composition according to claim 9 or 10, wherein the ratio of the blending amount of the third compound to the total blending amount of the first compound, the second compound and the third compound is 50% by weight or less.
The liquid crystal composition according to claim 9 or 10, wherein the ratio of the blending amount of the third compound to the total blending amount of the first compound, the second compound and the third compound is 7% by weight to 18% by weight.
The liquid crystal composition according to claim 9 or 10, wherein the ratio of the blending amount of the third compound to the total blending amount of the first compound, the second compound and the third compound is 7% by weight to 23% by weight.
The liquid crystal composition according to claim 9 or 10, wherein the ratio of the blending amount of the third compound to the total blending amount of the first compound, the second compound and the third compound is 18% by weight or less.
The liquid crystal composition according to claim 9 or 10, wherein the ratio of the blending amount of the third compound to the total blending amount of the first compound, the second compound and the third compound is 7% by weight to 35% by weight.
An actuator containing the liquid crystal composition according to any one of claims 1 to 15.
The actuator according to claim 16, further comprising a conductive coil, wherein the liquid crystal composition fills a gap in the coil.