Liquid crystal composition and actuator using the same

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

[Technical field]

[0001] The present invention relates to a liquid crystal composition and an actuator using the liquid crystal composition. [Background technology]

[0002] In recent years, with the miniaturization of electronic devices, dielectrics with high dielectric constants are in demand. For example, Non-Patent Document 1 reports a phenyldioxane-based liquid crystal compound that exhibits a liquid crystal phase with an abnormally large dielectric anisotropy (Δε) in a specific temperature range. Patent Document 1 also discloses a liquid crystal material that exhibits a high dielectric constant at a temperature at which a specific liquid crystal phase is exhibited. Such liquid crystal compounds exhibiting a high dielectric constant are expected to be applied to electronic devices such as displays and actuators. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Hiroya Nishikawa and 7 others, “Ferroelectric nematic?: Approaching elucidation of the mechanism of giant polarization order”, Journal of the Japanese Liquid Crystal Society, 2019, Vol. 23, No. 1, P. 35-45 [Patent documents]

[0004] [Patent Document 1] JP 2017-145298 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the liquid crystal compounds disclosed in Non-Patent Document 1 and Patent Document 1 crystallize (express a crystalline phase) at around room temperature. Since it is difficult to cause orientation polarization in the crystalline phase, these liquid crystal compounds have a problem in that they cannot obtain a high dielectric constant in the temperature range where electronic devices are expected to operate.

[0006] The present invention has been made to solve the above problems, and has an object to provide a liquid crystal composition having a high dielectric constant in the temperature range in which electronic devices are expected to be driven. [Means for solving the problem]

[0007] According to a first aspect of the present invention, there is provided a liquid crystal composition comprising a first compound represented by the following general formula (1) and a second compound represented by the following general formula (2):

[0008] [ka] In the general formula (1), R 1 represents 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 each independently represents a single bond, -COO-, or -CF2O-, B 11 , B 12 and B. 13 are each independently a hydrogen atom or a fluorine atom, D 1 is a fluorine atom, -CF3, or -OCF3. [ka] In general formula (2), R 2 represents 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 -CF2O-, B 21 and B. 22 are each independently a hydrogen atom or a fluorine atom.

[0009] 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).

[0010] [ka]

[0011] [ka]

[0012] The ratio of the amount of the first compound to the total amount of the first compound and the second compound may be 7% by weight to 93% by weight. Also, the ratio of the amount of the first compound to the total amount of the first compound and the second compound may be 17% by weight to 93% by weight, 20% by weight to 90% by weight, or 30% by weight to 75% by weight.

[0013] The ratio of the amount of the first compound to the total 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.

[0014] The liquid crystal composition may further contain a third compound represented by the following general formula (5). [ka] In general formula (5), R 5 represents 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 -CF2O-, B 51 and B. 52 are each independently a hydrogen atom or a fluorine atom, D 5 is a fluorine atom, -CF3, or -OCF3.

[0015] The third compound may be a compound represented by the following chemical formula (6). [ka]

[0016] The ratio of the amount of the third compound to the total amount of the first compound, the second compound, and the third compound may be 50% by weight or less, 7% by weight to 18% by weight, 7% by weight to 23% by weight, 18% by weight or less, or 7% by weight to 35% by weight.

[0017] According to a second aspect of the present invention, there is provided an actuator comprising the liquid crystal composition of the first aspect.

[0018] The actuator may include a conductive coil, and the liquid crystal composition may fill a gap in the coil. Effect of the Invention

[0019] The liquid crystal composition of the present invention has a high dielectric constant in the temperature range in which electronic devices are expected to operate (for example, near room temperature). [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram showing the relationship between the ratio (wt %) of the amount of the first compound to the total amount of the first compound and the second compound, and the phase transition temperature, in Samples 1 to 9 (liquid crystal compositions) prepared in the examples. [Diagram 2] FIG. 2 is a table showing the dielectric constant (εr': real part of relative dielectric constant) for each measurement temperature of Samples 1 to 9 (liquid crystal compositions) prepared in the examples. [Diagram 3] FIG. 3 is a diagram showing the relationship between temperature and the dielectric constant (εr': real part of relative dielectric constant) of Samples 1 to 9 (liquid crystal compositions) prepared in the examples. [Figure 4]FIG. 4 is a diagram showing the relationship between the ratio (wt %) of the amount of the first compound to the total amount of the first compound and the second compound and the dielectric constant (εr': real part of the relative dielectric constant) for each measurement temperature in Samples 1 to 9 (liquid crystal compositions) prepared in the examples. [Diagram 5] FIG. 5 is a diagram illustrating a synthesis scheme of the first compound represented by chemical formula (3). [Figure 6] FIG. 6 is a diagram illustrating a synthesis scheme of the second compound represented by chemical formula (4). [Figure 7] FIG. 7(a) is a polarizing microscope photograph of sample 4 prepared in this example at 80°C, FIG. 7(b) is a polarizing microscope photograph of sample 4 at 60°C, FIG. 7(c) is a polarizing microscope photograph of sample 4 at 30°C, and FIG. 7(d) is a polarizing microscope photograph of sample 4 at 10°C. [Figure 8] FIG. 8 is a graph showing the relationship between the ratio (wt %) of the amount of the third compound to the total amount of the first compound, the second compound, and the third compound, and the phase transition temperature in Samples 4 and 10 to 15 (liquid crystal compositions) prepared in the examples. [Figure 9] FIG. 9 is a table showing the dielectric constant (εr': real part of relative dielectric constant) for each measurement temperature of Samples 4 and 11 to 15 (liquid crystal compositions) prepared in the examples. [Figure 10] FIG. 10 is a diagram showing the relationship between temperature and the dielectric constant (εr': real part of relative dielectric constant) of Samples 4 and 11 to 15 (liquid crystal compositions) prepared in the examples. [Figure 11] FIG. 11 is a diagram showing the relationship between the ratio (wt %) of the amount of the third compound to the total amount of the first compound, the second compound, and the third compound, and the dielectric constant (εr': real part of the relative dielectric constant) for each measurement temperature in Samples 4 and 11 to 15 (liquid crystal compositions) prepared in the examples. [Figure 12] FIG. 12 is a diagram illustrating a synthesis scheme of the third compound represented by chemical formula (6). [Figure 13] FIG. 13 is a schematic diagram of an actuator using a liquid crystal composition according to an embodiment. [Figure 14]FIG. 14(a) is a photograph of the actuator produced in the example in a state where no voltage is applied, and FIG. 14(b) is a photograph of the actuator in a state where a voltage is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] [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) that are oriented in a specific temperature range to exhibit a liquid crystal phase.

[0022] [ka] In the general formula (1), R 1 represents 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 each independently represents a single bond, -COO-, or -CF2O-, B 11 , B 12 and B. 13 are each independently a hydrogen atom or a fluorine atom, D 1 is a fluorine atom, -CF3, or -OCF3.

[0023] [ka] In general formula (2), R 2 represents 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 -CF2O-, B 21 and B.22 are each independently a hydrogen atom or a fluorine atom.

[0024] The first compound is not particularly limited as long as it is a compound represented by general formula (1). The first compound may be one type of compound, or may contain two or more types of compounds.

[0025] 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 a 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 -CF2O-, and A 12 is a single bond, B 11 is a fluorine atom, and B 12 is a hydrogen atom, and B 13 is a fluorine atom, D 1 may be a fluorine atom, -CF3, or -OCF3.

[0026] R in general formula (1) 1 In the above, 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 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, for example, a methoxymethyl group, a 2-methoxyethyl group, or an ethoxymethyl group.

[0027] Specific examples of the first compound include 2,3',4',5'-tetrafluoro-(1,1'-biphenyl)-4-yl 2,6-difluoro-4-(5-propyl-1,3-dioxan-2-yl)benzoate, 2,3',5'-trifluoro-4'-(trifluoromethyl)-(1,1'-biphenyl)-4-yl 2,6-difluoro-4-(5-propyl-1,3-dioxan-2-yl)benzoate, 2,3',4',5'-tetrafluoro-(1,1'-biphenyl)-4-yl 2,6-difluoro-4-(5-ethyl-1,3-dioxan-2-yl)benzoate, 2,3',4',5'-tetrafluoro-(1,1'-biphenyl)-4-yl Examples of such benzoates include 2,6-difluoro-4-(5-butyl-1,3-dioxan-2-yl)benzoate, 2,3',4',5'-tetrafluoro-(1,1'-biphenyl)-4-yl 2,6-difluoro-4-(5-allyl-1,3-dioxan-2-yl)benzoate, and 2-(4-(difluoro((2,3',4',5'-tetrafluoro-(1,1'-biphenyl)-4-yl)oxy)methyl)-3,5-difluorophenyl)-5-propyl-1,3-dioxane.

[0028] Among them, the first compound is preferably a compound represented by the following chemical formula (3), i.e., 2,3',4',5'-tetrafluoro-(1,1'-biphenyl)-4-yl 2,6-difluoro-4-(5-propyl-1,3-dioxan-2-yl)benzoate. The first compound represented by chemical formula (3) is relatively easy to synthesize, and the use of the first compound represented by chemical formula (3) makes it easier to adjust the temperature range in which the liquid crystal composition exhibits a liquid crystal phase to around room temperature.

[0029] [ka] The first compound represented by chemical formula (3) is a compound represented by general formula (1), 1 is a propyl group (an alkyl group having 3 carbon atoms), A 11 is -COO- and A 12 is a single bond, B11 is a fluorine atom, and B 12 is a hydrogen atom, and B 13 is a fluorine atom, D 1 is a fluorine atom.

[0030] The second compound is not particularly limited as long as it is a compound represented by general formula (2). The second compound may be one type of compound, or may contain two or more types of compounds.

[0031] In general formula (2), R 2 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 a 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 -CF2O-, B 21 and B. 22 may both be fluorine atoms.

[0032] R in general formula (2) 2 In the above, 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 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, for example, a methoxymethyl group, a 2-methoxyethyl group, or an ethoxymethyl group.

[0033] Specific examples of the second compound include 4-cyano-3,5-difluorophenyl 2,6-difluoro-4-(5-propyl-1,3-dioxan-2-yl)benzoate, 4-cyano-3,5-difluorophenyl 2,6-difluoro-4-(5-ethyl-1,3-dioxan-2-yl)benzoate, 4-cyano-3,5-difluorophenyl 2,6-difluoro-4-(5-butyl-1,3-dioxan-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-dioxan-2-yl)phenyl)difluoromethoxy)-2,6-difluorobenzonitrile.

[0034] Among them, the second compound is preferably a compound represented by the following chemical formula (4), i.e., 4-cyano-3,5-difluorophenyl 2,6-difluoro-4-(5-propyl-1,3-dioxane-2-yl)benzoate. The second compound represented by chemical formula (4) is relatively easy to synthesize, and the use of the second compound represented by chemical formula (4) makes it easier to adjust the temperature range in which the liquid crystal composition exhibits a liquid crystal phase to around room temperature.

[0035] [ka]

[0036] The second compound represented by chemical formula (4) is a compound represented by general formula (2), 2 is a propyl group (an alkyl group having 3 carbon atoms), A 2 is -COO-, B 21 and B. 22 Both are fluorine atoms.

[0037] As shown in FIG. 2 and FIG. 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 range exceeding 40° C. This is presumed to be due to the first compound exhibiting a specific liquid crystal phase (M3 phase shown in FIG. 1) in this temperature range. The M3 phase is a polar nematic phase, and it is presumed that a ferroelectric orientation order exists in which the dipole moment parallel to the long axis of the liquid crystal molecules is locally aligned in one direction, which is the cause of the high dielectric constant. On the other hand, the first compound (sample 1) crystallizes near room temperature, so that the dielectric constant is low near room temperature. The present inventors have found that by mixing the first compound with the second compound, crystallization near room temperature (for example, 5 to 40° C.) is suppressed, and thus the mixture of the first compound and the second compound exhibits a high dielectric constant near room temperature. Thus, the liquid crystal composition of the present embodiment containing the first compound and the second compound has a high dielectric constant and is suppressed in crystallization near room temperature, where various electronic devices are expected to be driven.

[0038] It is speculated that the reason why the liquid crystal composition of the present embodiment exhibits a high dielectric constant near room temperature is that the above-mentioned specific liquid crystal phase, the M3 phase, appears near room temperature. As shown in Figures 2 and 3, as the ratio of the amount of the first compound to the total amount of the first compound and the second compound (hereinafter, appropriately described as "the ratio of the first compound in the liquid crystal mixture") decreases, the temperature range in which the high dielectric constant is exhibited shifts to the lower temperature side. Similarly, as shown in Figure 1, as the ratio of the first compound in the liquid crystal mixture decreases, the temperature range in which the M3 phase appears also shifts to the lower temperature side. As can be seen from Figures 1 and 2, the range in which the extremely high dielectric constant, with a relative dielectric constant of 10,000 or more, is exhibited is almost the same as the range in which the M3 phase appears.

[0039] The reason why the temperature range in which the M3 phase appears shifts to the lower temperature side as the ratio of the first compound in the liquid crystal mixture decreases is not clear, but is speculated as follows. As shown in FIG. 1 and Table 1 in the examples described later, the second compound (sample 9 in the examples described later) does not alone exhibit the M3 phase, but transitions (crystallizes) from the M2 phase to the crystalline phase at around room temperature. However, the second compound originally has the potential to exhibit the M3 phase at the lower temperature side of the temperature range in which the M2 phase appears, and it is speculated that the reason why the M3 phase does not appear is because molecular motion is suppressed by crystallization. The temperature range in which the second compound is speculated to exhibit the M3 phase is lower than the temperature range in which the first compound exhibits the M3 phase. In the liquid crystal composition of the present embodiment, it is speculated that the crystallization of the second compound at around room temperature is prevented by mixing the first compound, which is a foreign substance, with the second compound, and the M3 phase of the second compound is made possible. In addition, it is speculated that the crystallization of the first compound at around room temperature is prevented by mixing the first compound with the second compound, which is a foreign substance. As shown in FIG. 1, it is speculated that the temperature range in which the M3 phase appears approaches the temperature range in which the second compound exhibits the M3 phase, and shifts to a lower temperature side, as the ratio of the first compound in the liquid crystal mixture decreases, that is, as the ratio of the second compound increases. Note that these mechanisms are speculations and do not limit the present invention in any way.

[0040] In addition, in the liquid crystal composition of this embodiment, a liquid crystal phase (M4 phase) other than the M3 phase may be further expressed on the low temperature side of the M3 phase as shown in Fig. 1. Even in the temperature range in which the M4 phase is expressed, the liquid crystal composition of this embodiment exhibits a high dielectric constant, for example, a relative dielectric constant of 1,000 or more, or 2,000 or more.

[0041] As described above, the liquid crystal composition of this embodiment is inhibited from crystallizing and exhibits a liquid crystal phase at around room temperature, where various electronic devices are expected to be driven. Unlike a crystalline phase, a liquid crystal phase has flexibility and fluidity. Therefore, the liquid crystal composition of this embodiment is suitable for electronic devices that require flexibility and fluidity when driven. For example, the liquid crystal composition of this embodiment can easily follow the deformation of a device that involves deformation, such as an actuator. The liquid crystal composition of this embodiment can also be applied to devices that utilize the fluidity of the liquid crystal composition when driven, such as a display.

[0042] In the liquid crystal composition, the ratio of the amount of the first compound to the amount of the second compound is not particularly limited. For example, the ratio 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 less likely to crystallize around room temperature.

[0043] As shown in FIG. 2 to FIG. 4, the liquid crystal composition of the present embodiment can control the temperature range in which it exhibits a high dielectric constant by adjusting the ratio of the blending amount of the first compound to the blending amount of the second compound. This allows a desired liquid crystal composition to be designed according to the temperature range in which an 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, a high dielectric constant (e.g., a dielectric constant of 1,000 or more) can be obtained in the entire temperature range around room temperature in which various electronic devices are expected to be driven (e.g., 5 to 40° C.). In addition, for example, in the case of an electronic device used in a room where the temperature is controlled, the temperature range in which it is driven can be specified to a narrower range. In such applications, by setting the ratio of the first compound in the liquid crystal mixture to 20% by weight to 90% by weight, a higher dielectric constant (e.g., a dielectric constant of 3,000 or more) can be obtained at 15° C. to 30° C. Furthermore, by setting the ratio of the first compound in the liquid crystal mixture to 30% by weight to 75% by weight, an even higher dielectric constant (for example, a relative dielectric constant of 10,000 or more) can be obtained at 25° C. to 35° C.

[0044] As shown in FIG. 1, the liquid crystal composition of the present embodiment can control the temperature range in which a specific liquid crystal phase (for example, M3 phase and / or M4 phase) exhibiting a high dielectric constant is expressed by adjusting the ratio of the blending amount of the first compound and the blending amount of the second compound. This allows the composition of the liquid crystal composition to be designed 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 to a narrower range as described above, the ratio of the first compound in the liquid crystal mixture can be set to 27% by weight to 93% by weight, or 30% by weight to 90% by weight, to express the M3 phase or M4 phase having a high dielectric constant in the temperature range of 5 to 35° C. In addition, the ratio of the first compound in the liquid crystal mixture can be set to 17% by weight to 33% by weight, or 20% by weight to 30% by weight, to express the M3 phase having a higher dielectric constant in the temperature range of 15 to 25° C.

[0045] The synthesis method of the first compound and the second compound is not particularly limited, and they may be synthesized using a known method. For example, the first compound represented by the chemical formula (3) can be synthesized according to the synthesis scheme shown in Figure 5, and the second compound represented by the chemical formula (4) can be synthesized according to the synthesis scheme shown in Figure 6.

[0046] The synthesis scheme of the first compound shown in FIG. 5 will be described. First, 2-propyl-1,3-propanediol represented by formula (a) and 3,5-difluorobenzaldehyde represented by formula (b) are reacted in the presence of an acid catalyst to synthesize 2-(3,5-difluorophenyl)-5-propyl-1,3-dioxane represented by formula (c) (hereinafter referred to as compound (c)). Next, n-butyllithium is allowed to act on compound (c) at about -50°C to produce a lithiated product represented by formula (d), which is then reacted with carbon dioxide to produce 2,6-difluoro-4-(5-propyl-1,3-dioxane-2-yl)benzoic acid represented by formula (e) (hereinafter referred to as compound (e)). The compound (e) is reacted with 2,3',4',5'-tetrafluorobiphenyl-4-ol represented by formula (f) in the presence of 4-dimethylaminopyridine (DMAP) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDCI) to obtain a first compound represented by chemical formula (3).

[0047] The synthesis scheme of the second compound shown in Figure 6 will be described. First, compound (e) is synthesized according to the synthesis scheme shown in Figure 5. Next, compound (e) is reacted with 2,6-difluoro-4-hydroxybenzonitrile represented by formula (g) in the presence of DMAP and EDCI to obtain the second compound represented by chemical formula (4).

[0048] The liquid crystal composition of the present embodiment may be composed of only two kinds of compounds, the first compound and the second compound, or may be composed of only two components, the first compound represented by chemical formula (3) and the second compound represented by chemical formula (4). The liquid crystal compounds contained in the liquid crystal composition may be composed of only two kinds of compounds, the first compound and the second compound, or may be composed of only two components, the first compound represented by chemical formula (3) and the second compound represented by chemical formula (4).

[0049] 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. [ka] In general formula (5), R 5 represents 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 -CF2O-, B 51 and B. 52 are each independently a hydrogen atom or a fluorine atom, D 5 is a fluorine atom, -CF3, or -OCF3.

[0050] The third compound is a phenyldioxane-based compound like the first and second compounds, but unlike the first and second compounds, the third compound does not exhibit a liquid crystal phase by itself, i.e., the third compound is not a liquid crystal compound.

[0051] In 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 a terminal, an alkoxy group having 1 to 3 carbon atoms, or an alkoxyalkyl group having 2 to 3 carbon atoms, A 5 is -COO- or -CF2O-, B 51 and B. 52 are both fluorine atoms, D 5 may be a fluorine atom, -CF3 or -OCF3.

[0052] R in general formula (5) 5In the above, 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 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, for example, a methoxymethyl group, a 2-methoxyethyl group, or an ethoxymethyl group.

[0053] Specific examples of the third compound include 3,4,5-trifluorophenyl 2,6-difluoro-4-(5-propyl-1,3-dioxan-2-yl)benzoate, 3,5-difluoro-4-(trifluoromethyl)phenyl 2,6-difluoro-4-(5-ethyl-1,3-dioxan-2-yl)benzoate, 3,4,5-trifluorophenyl 2,6-difluoro-4-(5-ethyl-1,3-dioxan-2-yl)benzoate, 3,4,5-trifluorophenyl 2,6-difluoro-4-(5-butyl-1,3-dioxan-2-yl)benzoate, and 3,4,5-trifluorophenyl. 2,6-difluoro-4-(5-allyl-1,3-dioxan-2-yl)benzoate, and 2-(4-(difluoro(3,4,5-trifluorophenyl)methoxy)-3,5-difluorophenyl)5-propyl-1,3-dioxane.

[0054] Among them, the third compound is preferably a compound represented by the following chemical formula (6), i.e., 3,4,5-trifluorophenyl 2,6-difluoro-4-(5-propyl-1,3-dioxane-2-yl)benzoate. The first compound represented by chemical formula (6) is relatively easy to synthesize, and the use of the third compound represented by chemical formula (6) makes it easier to adjust the temperature range in which the liquid crystal composition exhibits a liquid crystal phase to around room temperature. [ka]

[0055] The third compound represented by chemical formula (6) is a compound represented by general formula (5), 5 is a propyl group (an alkyl group having 3 carbon atoms), A 5 is -COO-, B 51 and B. 52 are both fluorine atoms, D 5 is a fluorine atom.

[0056] The present inventors have found that the temperature range in which the M3 phase, which exhibits a high dielectric constant, appears can be shifted further to the lower temperature side by further blending a third compound with the first and second compounds. This makes it easier to adjust the temperature range in which a high dielectric constant is exhibited to around room temperature. In the examples described later, the blended amount of the third compound was changed and added to the first and second compounds, and the phase transition temperature of the resulting blend (sample) was measured. The results are shown in FIG. 8. In the examples described later, the dielectric constant (ε r The dielectric constant (εr': real part of the dielectric constant) was also measured. The results are shown in FIG. 9. Furthermore, based on the data shown in FIG. 9, the relationship between the temperature and the dielectric constant (εr': real part of the dielectric constant) of each sample is shown in FIG. 10. As shown in FIG. 8, as the ratio of the amount of the third compound to the total amount of the first compound, the second compound, and the third compound (hereinafter, appropriately described as "the ratio of the third compound in the blend") increases, the temperature range in which the M3 phase appears shifts to the lower temperature side. Similarly, as shown in FIG. 9 and FIG. 10, as the ratio of the third compound in the blend increases, the temperature range in which a high dielectric constant is shown shifts to the lower temperature side. As can be understood from FIG. 8 and FIG. 9, even in the three-component liquid crystal composition containing the third compound, the range in which a very high dielectric constant of 10,000 or more is shown almost coincides with the range in which the M3 phase appears.

[0057] The reason why the temperature range in which the M3 phase appears shifts to the lower temperature side as the proportion of the third compound in the blend increases is unclear, but is speculated as follows. The third compound is a phenyldioxane compound, the same as the first and second compounds, and is therefore easily mixed uniformly with the first and second compounds. On the other hand, the third compound itself is not a liquid crystal compound, and therefore inhibits the molecular arrangement of the first and second compounds to form the M3 phase (liquid crystal phase). For this reason, it is speculated that the M3 phase appears at a lower temperature in a three-component liquid crystal composition containing the third compound, compared to a two-component liquid crystal composition not containing the third compound. Note that these mechanisms are speculations and do not limit the present invention in any way.

[0058] 8, even in a three-component liquid crystal composition including a third compound, a liquid crystal phase (M4 phase) other than 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 is expressed, the liquid crystal composition of the present embodiment exhibits a high dielectric constant, for example, a relative dielectric constant of 1,000 or more, or 2,000 or more.

[0059] In a three-component liquid crystal composition containing a third compound, the ratio of the third compound in the mixture is not particularly limited. As shown in Figs. 9 to 11, the liquid crystal composition of this embodiment can control the temperature range in which it exhibits a high dielectric constant by adjusting the ratio of the third compound in the mixture. This allows a desired liquid crystal composition to be designed according to the temperature range in which an electronic device such as an actuator using the liquid crystal composition is expected to be driven.

[0060] For example, as shown in FIG. 9, by setting the ratio of the third compound in the blend to more than 0% by weight and 50% by weight or less, the temperature range in which the M3 phase appears can be shifted to the lower temperature side compared to a two-component liquid crystal composition not containing the third compound, while suppressing crystallization near room temperature (for example, 5 to 40°C) like a two-component liquid crystal composition. In addition, by setting the ratio of the third compound in the blend to 7% by weight to 18% by weight, preferably 10% by weight to 15% by weight, a high dielectric constant (for example, a relative dielectric constant of 1,000 or more) can be obtained in the entire temperature range near room temperature (for example, 5 to 40°C) where various electronic devices are expected to be driven. In addition, for example, in the case of an electronic device used in a room where the temperature is controlled, the temperature range in which it is driven can be specified to a narrower range. In such applications, by setting the ratio of the third compound in the blend to 7% by weight to 23% by weight, preferably 10% by weight to 20% by weight, a higher dielectric constant (for example, a relative dielectric constant of 3,000 or more) can be obtained at 15°C to 30°C. Furthermore, by setting the proportion of the third compound in the formulation to more than 0% by weight and not more than 18% by weight, preferably not more than 15% by weight, it is possible to obtain an even higher dielectric constant (for example, a relative dielectric constant of 10,000 or more) at 25°C to 35°C.

[0061] In addition, as shown in FIG. 8, the liquid crystal composition of this embodiment can control the temperature range in which a specific liquid crystal phase (for example, M3 phase and / or M4 phase) exhibiting a high dielectric constant is expressed by adjusting the ratio of the third compound. This allows the composition of the liquid crystal composition to be designed 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 to a narrower range as described above, the ratio of the third compound can be made to be more than 0% by weight and 18% by weight or less, preferably 15% by weight or less, to express the M3 phase or M4 phase having a high dielectric constant in the temperature range of 5 to 35° C. In addition, the ratio of the third compound in the formulation can be made to be 7% by weight to 35% by weight, preferably 10% by weight to 33% by weight, to express the M3 phase having a higher dielectric constant in the temperature range of 15 to 25° C.

[0062] 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 chemical formula (6) can be synthesized according to the synthesis scheme shown in FIG. 12. First, the 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 formula (h) in the presence of DMAP and EDCI to obtain the third compound represented by chemical formula (6).

[0063] The liquid crystal composition of the present embodiment may be composed of only three types of compounds, namely, the first compound, the second compound, and the third compound, or may be composed of only three components, namely, the first compound represented by chemical formula (3), the second compound represented by chemical formula (4), and the third compound represented by chemical formula (6).

[0064] When the liquid crystal composition of the present embodiment does not contain a third compound, the total amount of the first compound and the second compound in the liquid crystal composition of the present embodiment may be, for example, 50% by weight or more, 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 a third compound, the total amount of the first compound, the second compound, and the third compound in the liquid crystal composition of the present embodiment may be, for example, 50% by weight or more, 80% by weight or more, 90% by weight or more, or 98% by weight or more.

[0065] The liquid crystal composition of the present embodiment may further contain a liquid crystal compound different from the first compound and the second compound, so long as the effects of the present embodiment are achieved. In addition, the liquid crystal composition may further contain known additives other than the liquid crystal compound, such as an antioxidant, an ultraviolet absorber, a surfactant, etc. In addition, in order to facilitate the fixation of the liquid crystal composition on an arbitrary support, the liquid crystal composition may further contain an additional compound or a dispersion medium for elastomerizing or gelling the liquid crystal composition.

[0066] The liquid crystal composition of the present embodiment can be prepared by mixing the first compound, the second compound, and optionally the third compound, and other additives by a known method. For example, the first compound, the second compound, and optionally the third compound may be dissolved in a solvent and mixed, and then the solvent may be removed to prepare the liquid crystal composition. Alternatively, the first compound, the second compound, and optionally the third compound may be directly mixed without using a solvent to prepare the liquid crystal composition. 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 a liquid state. Alternatively, the first compound, the second compound, and optionally the third compound may be mixed (primary mixing), the mixture may be heated, and the heated mixture may be further mixed (secondary mixing) to prepare the liquid crystal composition. Alternatively, in order to facilitate the fixation of the liquid crystal composition on an arbitrary support, the liquid crystal composition may be elastomerized, gelled, or the like by using an additional compound, a dispersion medium, or the like, and / or additional treatment.

[0067] [Actuator] The liquid crystal composition of the present embodiment described above can be applied to various electronic devices. As an example, an actuator (driving device) 100 using the liquid crystal composition is shown in Fig. 13. The actuator 100 has the liquid crystal composition 10 of the present embodiment and a pair of spiral (coil) electrodes 20 embedded (covered) in the liquid crystal composition 10.

[0068] The actuator 100 can be produced by preparing a pair of coils 20a and 20b as the electrodes 20 and filling the gap between the coils with the liquid crystal composition 10 by a known method. The coils 20a and 20b may be produced by winding a conductor in a spiral shape. Alternatively, the coils 20a and 20b may be produced by producing a resin spiral structure using a 3D printer and coating it with a plating film to make it conductive. In this case, the coils 20a and 20b are arranged in a double spiral shape by overlapping each other so that the windings do not come into contact with each other, as shown in FIG. 13. In order to prevent short-circuiting between the coils, a spacer (not shown) may be further provided between the coils 20a and 20b. The spacer may be, for example, a spiral structure made of insulating resin produced by a 3D printer. By twisting the coils 20a and 20b into the spiral spacer to integrate them, short-circuiting between the spiral coils can be prevented. The actuator 100 can be produced by covering the gaps between the coils 20a and 20b (the gaps between the coil windings) with the liquid crystal composition 10 so as to fill them.

[0069] The actuator 100 is driven to expand and contract in the direction of the arrows shown in FIG. 13 by applying a voltage between the electrodes in a temperature range in which the liquid crystal composition 10 exhibits a liquid crystal phase. This is because the liquid crystal composition 10 has a high dielectric constant, and thus a large electrostatic force is generated by applying a voltage between the coils 20a and 20b interposed between the liquid crystal composition 10. If the liquid crystal composition 10 has a high dielectric constant, the electrostatic force between the electrodes is large, and the driving range of the actuator 100 can be increased. As described above, the liquid crystal composition 10 of this embodiment can adjust the temperature range in which a specific liquid crystal phase (e.g., M3 phase and / or M4 phase) exhibiting a high dielectric constant to be near room temperature by adjusting its composition. This makes it possible to realize an actuator 100 having a large driving force near room temperature. EXAMPLES

[0070] Next, examples of the present invention will be described together with comparative examples. Note that the present invention is not limited to these examples and comparative examples, and can be appropriately modified within the scope of the technical ideas described in the claims.

[0071] [Liquid crystal composition] <Preparation of Liquid Crystal Composition 1> Two-component liquid crystal compositions (samples 1 to 9) containing a first compound and a second compound were prepared by the method described below. [Sample 1] 5, a first compound represented by chemical formula (3) was synthesized and used as sample 1. That is, the proportion of the first compound in the liquid crystal mixture of sample 1 was 100% by weight.

[0072] [Sample 2] A first compound represented by chemical formula (3) was synthesized according to the synthesis scheme shown in FIG. 5, and a second compound represented by chemical formula (4) was synthesized according to the synthesis scheme shown in FIG. 6. The first compound represented by chemical formula (3) and the second compound represented by chemical formula (4) were dissolved in a solvent (chloroform) to prepare a solution. The total amount of the first compound and the second compound in the solution was 1% by weight. The ratio 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).

[0073] [Samples 3-8] In Samples 3 to 8, the ratio of the first compound in the liquid crystal mixture was 75% by weight, 50% by weight, 40% by weight, 30% by weight, 20% by weight, and 10% by weight, respectively. Otherwise, Samples 3 to 8 (liquid crystal compositions) were obtained in the same manner as Sample 2.

[0074] [Sample 9] A second compound represented by chemical formula (4) was synthesized according to the synthesis scheme shown in Fig. 6, and the second compound was designated as sample 9. That is, in sample 9, the ratio of the first compound in the liquid crystal mixture was 0 wt%.

[0075] Samples 2 to 8 correspond to Examples, and Samples 1 and 9 correspond to Comparative Examples.

[0076] <Evaluation of Liquid Crystal Composition 1> (1) Evaluation of liquid crystallinity The liquid crystallinity of Samples 1 to 9 was evaluated by differential scanning calorimetry (DSC) and observation with a polarizing microscope (POM).

[0077] (a) Differential scanning calorimetry (DSC) Approximately 5 mg of the sample was placed in an aluminum sample pan and placed in a differential scanning calorimeter (Perkin Elmer, DSC8000). An empty aluminum sample pan was used as a reference, and the sample was heated to 90°C and then cooled to 0°C at a rate of 5°C / min, and differential scanning calorimetry was performed during the cooling process.

[0078] (b) Polarizing microscope observation The sample injected into the glass cell was observed under crossed Nicols using a polarizing microscope (OLYMPUS, BX53) while the temperature was controlled using a microscope hot stage (Mettler Toledo, HS82) equipped with a cooling mechanism using liquid nitrogen.

[0079] The liquid crystal phases confirmed by differential scanning calorimetry and polarizing microscope observation, and the derived phase transition temperatures and crystallization temperatures are shown in Table 1 and Figure 1. Also, Figures 7(a) to (d) show polarizing microscope photographs of Sample 4 at 80°C, 60°C, 30°C, and 10°C, respectively.

[0080] [Table 1]

[0081] Three types of liquid crystal phases were observed during the cooling process of samples 1 to 8. These liquid crystal phases are denoted as M1 phase, M2 phase, and M3 phase from the high temperature side. In samples 3 to 6, another liquid crystal phase was observed on the lower temperature side of the M3 phase. This liquid crystal phase is denoted as M4 phase. Therefore, Figures 7(a) to (d) are polarized microscope photographs of the M1 phase, M2 phase, M3 phase, and M4 phase, respectively. In addition, in sample 9, the M1 phase and M2 phase were observed, but the M3 phase was not observed. From the polarized microscope observation, it is presumed 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 addition, in a general phase transition, a higher order phase appears as the temperature decreases, but this order is reversed in the transition from the M2 phase to the M3 phase. That is, the smectic phase (M2 phase) transitions again to a nematic phase (M3 phase), which is a lower-order ordered phase, at the lower temperature side. Therefore, it is presumed that the M3 phase is a reentrant nematic phase. Within the measurement temperature range, the sample 1 consisting only of the first compound and the sample 9 consisting only of the second compound crystallized and a crystalline phase was confirmed, but the crystalline phase was not confirmed in the samples 2 to 8. It is presumed that the crystalline phase of the samples 2 to 8 exists below 0°C, which is outside the measurement temperature range. Furthermore, within the measurement temperature range, the isotropic phase (liquid) of all the samples 1 to 9 was not confirmed, and it is presumed that they exist in a temperature range exceeding 90°C, which is outside the measurement temperature range.

[0082] (2) Measurement of dielectric constant The sample was poured into a 10μm gap cell with an ITO electrode of 10mm x 10mm area, and the temperature was controlled by a microscope hot stage (Mettler Toledo, HS82) equipped with a liquid nitrogen cooling mechanism. The temperature dependence of Cp (equivalent parallel capacitance) at 100Hz was measured using a frequency response analyzer (FRA) (NF Corporation, FRA51615). The measurement voltage was DC: 0V, AC: 3.6Vpp.

[0083] The dielectric constant (ε rThe dielectric constant (R: real part of the dielectric constant) was calculated for each measurement temperature. The results are shown in the table in Figure 2. ε r '=(t×Cp) / (A×ε0) ε r ': real part of relative dielectric constant t: sample thickness (in this example, cell gap) Cp: ​​equivalent parallel capacitance A: Electrode area ε0: Dielectric constant of vacuum

[0084] Based on the data shown in Figure 2, the temperature and dielectric constant (ε r The relationship between the ratio (weight %) of the first compound in the liquid crystal mixture and the dielectric constant (ε r The relationship between the dielectric constant and the dielectric constant (ε: real part of the dielectric constant) is shown in Figure 4.

[0085] (3) Discussion 2 and 3, Samples 2 to 8 containing the first compound and the second compound exhibited liquid crystal phases (M2 phase, M3 phase, M4 phase) at around room temperature (for example, 5° C. to 40° C.) and did not crystallize. On the other hand, Sample 1 containing only the first compound and Sample 9 containing only the second compound crystallized at around room temperature.

[0086] Moreover, samples 2 to 8 containing the first compound and the second compound exhibited a high dielectric constant (e.g., a dielectric constant of 1,000 or more) near room temperature (e.g., 5°C to 40°C). On the other hand, sample 1 containing only the first compound exhibited a high dielectric constant in the high temperature range exceeding 40°C, but the dielectric constant near room temperature was low (dielectric constant 3 to 4). Sample 9 containing only the second compound also had a low dielectric constant near room temperature (dielectric constant 3), and furthermore, the dielectric constant was less than 1,000 over the entire measurement temperature range.

[0087] As shown in FIG. 2 and FIG. 3, as the ratio of the first compound in the liquid crystal mixture decreases, the temperature range showing a high dielectric constant shifts to the lower temperature side. The temperature range showing a high dielectric constant can be controlled by adjusting the ratio of the first compound in the liquid crystal mixture. 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 dielectric constant is a high value of 1,000 or more in the entire temperature range of 5 to 40°C. 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 dielectric constant is a higher value of 3,000 or more in the entire temperature range of 15 to 30°C. Moreover, when the ratio of the first compound in the liquid crystal mixture is 30% by weight to 75% by weight, the relative dielectric constant is an even higher value of 10,000 or more in the entire temperature range of 25 to 35°C.

[0088] As shown in FIG. 1, as the ratio of the first compound in the liquid crystal mixture decreased, the temperature range in which the M3 phase appeared also shifted to the lower temperature side. As can be seen from FIG. 1 and FIG. 2, the range in which the liquid crystal composition exhibited a very high dielectric constant of 10,000 or more was almost the same as the range in which the M3 phase appeared. In addition, even in the temperature range in which the M4 phase appeared, the liquid crystal composition exhibited a high dielectric constant, for example, of 1,000 or more or 2,000 or more. By adjusting the ratio of the first compound in the liquid crystal mixture, the temperature range in which a specific liquid crystal phase exhibiting a high dielectric constant (for example, the M3 phase and / or the M4 phase) appeared can be controlled. As shown in FIG. 1, when the ratio of the first compound in the liquid crystal mixture was 27% by weight to 93% by weight, the M3 phase or the M4 phase appeared in the entire temperature range of 5 to 35° C. Furthermore, when the ratio of the first compound in the liquid crystal mixture was 17% by weight to 33% by weight, the M3 phase appeared in the entire temperature range of 15 to 25° C.

[0089] <Preparation of Liquid Crystal Composition 2> Three-component liquid crystal compositions (samples 10 to 15) containing a first compound, a second compound, and a third compound were prepared by the method described below.

[0090] [Sample 10] A third compound represented by chemical formula (6) was synthesized according to the synthesis scheme shown in Fig. 12 and designated as sample 10. That is, sample 10 is a sample that does not contain the first compound or the second compound and contains only the third compound.

[0091] [Sample 11] A three-component liquid crystal composition was prepared in which the ratio of the third compound in the mixture consisting 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.

[0092] First, the first compound represented by chemical formula (3) was synthesized according to the synthesis scheme shown in FIG. 5, the second compound represented by chemical formula (4) was synthesized according to the synthesis scheme shown in FIG. 6, and the third compound represented by chemical formula (6) was synthesized according to the synthesis scheme shown in FIG. 12. The synthesized first compound, second compound, and third compound were dissolved in a solvent (chloroform) in the weight ratio described above to prepare a solution. The total blend amount of the first compound, second compound, and third compound in the solution was 1 wt %. Next, the solvent was removed by vacuum drying to obtain sample 11 (liquid crystal composition).

[0093] [Samples 12-15] In Samples 12 to 15, the ratio of the third compound in the blend was 33 wt%, 20 wt%, 15 wt%, and 10 wt%, respectively. Except for that, Samples 12 to 15 (liquid crystal compositions) were prepared in the same manner as Sample 11.

[0094] Samples 11 to 15 correspond to examples, and sample 10 corresponds to a comparative example.

[0095] <Evaluation of Liquid Crystal Composition 2> (1) Evaluation of liquid crystallinity The liquid crystallinity of Samples 10 to 15 was evaluated by the same evaluation method as Samples 1 to 9 described above, i.e., differential scanning calorimetry (DSC) and polarizing microscope (POM) observation. The liquid crystal phases confirmed by differential scanning calorimetry and polarizing microscope observation, and the derived phase transition temperatures and crystallization temperatures are shown in Table 2 and FIG. 8. For comparison, the evaluation results of Sample 4 are also shown in Table 2 and FIG. 8. In Sample 4, the proportion of the third compound was 0% by weight, and the weight ratio of the first compound to the second compound was (first compound):(second compound)=50:50.

[0096] [Table 2]

[0097] In the cooling process of samples 11 to 15, three types of liquid crystal phases, M1 phase, M2 phase, and M3 phase, were confirmed, as in samples 1 to 8. In sample 15, an M4 phase was confirmed at a lower temperature side than the M3 phase, as in samples 3 to 6. Within the measurement temperature range, the isotropic phase (liquid) of samples 11 to 15 was not confirmed, and it is presumed that it exists in a temperature range exceeding 90°C, which is outside the measurement temperature range. Furthermore, within the measurement temperature range (temperature range of 0°C or higher), the crystalline phase of samples 11 to 15 was not confirmed. It is presumed that the crystalline phase of samples 11 to 15 exists below 0°C, which is outside the measurement temperature range. On the other hand, in sample 10 (third compound: 100% by weight), the isotropic phase (liquid phase) crystallized at 15°C and did not express a liquid crystal phase. In other words, it was confirmed that the third compound is not a liquid crystal compound.

[0098] (2) Measurement of dielectric constant The dielectric constant (ε r The dielectric constant (Relative permittivity (Relative permittivity) is calculated for each temperature. The measurement voltage was DC: 0V, AC: 0.1Vpp. The results are shown in the table of FIG. 9. For comparison, the dielectric constant of sample 4 was also measured in the same manner, and the results are also shown in the table of FIG. 9.

[0099] Based on the data shown in FIG. 9, the temperature and dielectric constant (ε rThe relationship between the ratio (weight %) of the third compound and the dielectric constant (ε r The relationship between the dielectric constant and the dielectric constant (ε: real part of the dielectric constant) is shown in Figure 11.

[0100] (3) Discussion 8 to 11, in the three-component liquid crystal compositions of Samples 11 to 15, the temperature range in which a high dielectric constant is exhibited shifts to the lower temperature side as the ratio of the third compound increases. Therefore, the temperature range in which a high dielectric constant is exhibited can be controlled by adjusting the ratio of the third compound in the composition.

[0101] As shown in Figs. 8 to 11, when the ratio of the third compound in the blend was more than 0% by weight and less than 50% by weight (samples 11 to 15), it was confirmed that the liquid crystal phase was expressed near room temperature and that crystallization did not occur in the temperature range of 0°C or higher. When the ratio of the third compound in the blend was 7% by weight to 18% by weight (samples 14 and 15), the relative dielectric constant was a high value of 1,000 or more in the entire temperature range of 5 to 40°C. When the ratio of the third compound in the blend was 7% by weight to 23% by weight (samples 13 to 15), the relative dielectric constant was a higher value of 3,000 or more in the entire temperature range of 15 to 30°C. In addition, when the ratio of the third compound in the blend was more than 0% by weight and less than 18% by weight (samples 14 and 15), the relative dielectric constant was an even higher value of 10,000 or more in the entire temperature range of 25 to 35°C.

[0102] As shown in FIG. 8, as the ratio of the third compound increases, the temperature range in which the M3 phase appears also shifts to the lower temperature side. As can be seen from FIG. 8 and FIG. 9, even in the three-component liquid crystal composition, the range in which the relative dielectric constant is very high, 10,000 or more, is almost the same as the range in which the M3 phase appears. Also, in the temperature range in which the M4 phase appears, the liquid crystal composition exhibits a high dielectric constant, 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 (e.g., M3 phase and / or M4 phase) exhibiting a high dielectric constant appears can be controlled.

[0103] 1, when the ratio of the third compound was more than 0 wt% and not more than 18 wt% (samples 14 and 15), the M3 phase or M4 phase appeared in the entire temperature range of 5 to 35° C. When the ratio of the third compound was 7 wt% to 35 wt% (samples 12 to 15), the M3 phase appeared in the entire temperature range of 15 to 25° C.

[0104] [Actuator] Using a liquid crystal composition having the same composition as sample 4, an actuator 100 shown in FIG.

[0105] <Fabrication of the actuator> First, a double-helix structure made of resin was produced using a 3D printer, which was then coated with a plating film to make it conductive, thereby obtaining an electrode 20 consisting of a pair of coils 20a, 20b. As a spacer (not shown) for preventing short-circuiting of the electrode 20, a double-helix structure made of insulating resin was produced using a 3D printer in the same manner as the electrode 20. The double-helix electrode 20 was twisted into the double-helix spacer to be integrated.

[0106] Next, in the same manner as in the preparation of sample 4, the first compound represented by chemical formula (3) and the second compound represented by chemical formula (4) were dissolved in a solvent (chloroform) to prepare a solution with a liquid crystal mixture concentration of 1% by weight. The weight ratio of the first compound to the second compound was 50:50. The solvent component was removed from the prepared solution by vacuum distillation and vacuum drying in an oven at 50°C. The obtained liquid crystal composition was heated in an oven at 85°C to form an M1 phase, and then injected with a pipette into the electrode 20 integrated with the spacer. As a result, an actuator 100 in which the electrode 20 was covered with the liquid crystal composition 10 was obtained.

[0107] <Actuator driving experiment> At room temperature (around 20°C), actuator 100 was connected to a power source and a voltage of 200 V was applied. Fig. 14(a) is a photograph of the actuator when no voltage is applied, and Fig. 14(b) is a photograph of the actuator when a voltage is applied. The length of actuator 100 when no voltage is applied was 32.6 mm (see Fig. 14(a)), but application of voltage caused the actuator to shrink by approximately 19%, resulting in a length of 26.3 mm. From this result, it was confirmed that the fabricated actuator could be operated sufficiently at room temperature. [Industrial Applicability]

[0108] The liquid crystal composition of the present invention is inhibited from crystallizing and exhibits a high dielectric constant at around room temperature, where various electronic devices are expected to be driven, and can therefore be used in electronic devices such as displays, actuators, capacitors, memories, piezoelectric elements, and inorganic EL components.

Claims

1. A liquid crystal composition comprising: A first compound represented by the following general formula (1): A liquid crystal composition comprising: 【Chemistry 1】 In 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 each independently represents a single bond, -COO-, or -CF ２ O-, B １１ , B １２ and B １３ are each independently a hydrogen atom or a fluorine atom, D １ is a fluorine atom, -CF ３ , or -OCF ３ It is. 【Chemistry 2】 In the general formula (2), R ２ 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 each independently a hydrogen atom or a fluorine atom.

2. The first compound is a compound represented by the following chemical formula (3):

2. The liquid crystal composition according to claim 1, wherein the second compound is a compound represented by the following chemical formula (4): 【Chemistry 3】 【Chemistry 4】

3. 3. The liquid crystal composition according to claim 1, wherein the ratio of the amount of the first compound to the total amount of the first compound and the second compound is 7% by weight to 93% by weight.

4. 3. The liquid crystal composition according to claim 1, wherein the ratio of the amount of the first compound to the total amount of the first compound and the second compound is 17% by weight to 93% by weight.

5. 3. The liquid crystal composition according to claim 1, wherein the ratio of the amount of the first compound to the total amount of the first compound and the second compound is 20% by weight to 90% by weight.

6. 3. The liquid crystal composition according to claim 1, wherein the ratio of the amount of the first compound to the total amount of the first compound and the second compound is 30% by weight to 75% by weight.

7. 3. The liquid crystal composition according to claim 1, wherein the ratio of the amount of the first compound to the total amount of the first compound and the second compound is 27% by weight to 93% by weight.

8. 3. The liquid crystal composition according to claim 1, wherein the ratio of the amount of the first compound to the total amount of the first compound and the second compound is 17% by weight to 33% by weight.

9. 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): 【Chemistry 5】 In 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 each independently a hydrogen atom or a fluorine atom, D ５ is a fluorine atom, -CF ３ , or -OCF ３ It is.

10. 10. The liquid crystal composition according to claim 9, wherein the third compound is a compound represented by the following chemical formula (6): 【Chemistry 6】

11. 11. The liquid crystal composition according to claim 9, 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.

12. 11. The liquid crystal composition according to claim 9, wherein the ratio of the amount of the third compound to the total amount of the first compound, the second compound and the third compound is 7% by weight to 18% by weight.

13. 11. The liquid crystal composition according to claim 9, wherein the ratio of the amount of the third compound to the total amount of the first compound, the second compound and the third compound is 7% by weight to 23% by weight.

14. 11. The liquid crystal composition according to claim 9, wherein the ratio of the amount of the third compound to the total amount of the first compound, the second compound and the third compound is 18% by weight or less.

15. 11. The liquid crystal composition according to claim 9, wherein the ratio of the amount of the third compound to the total amount of the first compound, the second compound and the third compound is 7% by weight to 35% by weight.

16. An actuator comprising the liquid crystal composition according to any one of claims 1 to 15.

17. 17. The actuator of claim 16, further comprising a conductive coil, the liquid crystal composition filling a gap in the coil.

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