JP2018006517A - Capacitor using liquid crystal material showing high dielectric constant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitor using a liquid crystal material developing a specific liquid crystal phase and showing a large dielectric constant.SOLUTION: The capacitor relating to an embodiment of the present invention includes a pair of electrodes disposed opposing to each other and a dielectric material disposed between the pair of electrodes. The dielectric material comprises a liquid crystal material that is SHG active at a temperature where the material develops a specific liquid crystal phase and that shows a dielectric constant of 100 or more. The electrode of the capacitor relating to the embodiment of the present invention is a porous conductor.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a capacitor using a liquid crystal material exhibiting a high dielectric constant.

A capacitor is composed of a pair of electrodes disposed opposite to each other and a dielectric disposed between the pair of electrodes. Electric charge is stored by applying a voltage between the electrodes, and storage by short-circuiting the capacitor. It is an element from which the generated charge is released.
The capacitance C (F: Farad) of the capacitor is expressed by the following formula (1).
_{C = ε S × ε 0 ×} S / d ····· (1)
In equation (1), ε _S is the relative dielectric constant of the dielectric used, ε ₀ is the vacuum dielectric constant, S is the electrode area (m ² ), and d is the distance between the electrodes (m).
The amount of charge Q (C: Coulomb) stored in the capacitor is expressed by the following equation (2).
Q = CV (2)
In Formula (2), C is a capacitance (F), and V is an applied voltage (V).
The energy E (J: Joule) stored in the capacitor is expressed by the following equation (3).
^{E = C × V 2/2} ····· (3)
Unlike a chemical battery, a capacitor stores energy as it is without being converted, so it is suitable for rapid charge / discharge, but the energy that can be stored is smaller than that of a chemical battery.

  The energy stored in the capacitor is increased by increasing the voltage or increasing the capacitance from the equation (3). From formula (1), it can be seen that it is effective to increase the electrode area and use a dielectric having a large relative dielectric constant in order to increase the capacitance.

Patent Document 1 (International Publication No. WO99 / 22388) discloses a capacitor using a liquid crystal material having a relative dielectric constant of 2500 as a dielectric and using activated carbon having a large specific surface area as an electrode. According to Non-Patent Document 1, the liquid crystal material used in Patent Document 1 is K 50 S _C ^* 54 S _A 66 I (where K is a crystalline phase, S _C ^* is a chiral smectic C phase, and SA is a smectic A). Phase, I represents isotropic phase).

International Publication Number WO99 / 22388

Molecular Crystals and Liquid Crystals, Letters Section (1986), 4, (2), 31-37

  The capacitor described in Patent Document 1 uses a liquid crystal material that exhibits a smectic phase as a liquid dielectric, but the liquid crystal material in the smectic phase is poor in fluidity and weak against vibration and impact. There is a need for a capacitor using a liquid crystal material having fluidity and capable of storing large energy in a capacitor that is resistant to vibration and impact and has a high energy density and a high output density.

  Under such circumstances, there is a demand for a capacitor using a liquid crystal material that exhibits a specific liquid crystal phase, the liquid crystal material having fluidity in the specific liquid crystal phase and exhibiting a large dielectric constant.

  The inventors of the present invention have found that a liquid crystal material that expresses a specific liquid crystal phase has fluidity and exhibits a large dielectric constant, and uses the liquid crystal material for a capacitor to solve the problem of the present invention. It came to.

The present invention includes the following aspects of the invention.
[1]
A capacitor including a pair of electrodes disposed opposite to each other and a dielectric disposed between the pair of electrodes,
The capacitor, wherein the dielectric includes a liquid crystal material that is SHG active at a temperature at which a specific liquid crystal phase is developed and exhibits a dielectric constant of 100 or more.
[2]
The capacitor according to [1], wherein the electrode is a porous conductor.
[3]
The capacitor according to [2], wherein the porous conductor is impregnated with the liquid crystal material.
[4]
The capacitor according to any one of [1] to [3], wherein a dielectric constant of the liquid crystal material at a temperature at which the specific liquid crystal phase is developed is 1000 or more.
[5]
The capacitor according to any one of [1] to [4], wherein in the specific liquid crystal phase, the liquid crystal material exhibits a ferroelectric or antiferroelectric behavior.
[6]
The intensity of SHG light at an incident angle of 30 ° of the liquid crystal material at a temperature at which the specific liquid crystal phase is developed is such that the liquid crystal material has an incident angle of 30 at a temperature at which the liquid crystal material exhibits a phase different from the specific liquid crystal phase. The capacitor according to any one of [1] to [5], which is 2 to 10 times larger than the intensity of SHG light at °.
[7]
The capacitor according to [6], wherein the phase different from the specific liquid crystal phase is a crystal phase or an isotropic phase of the liquid crystal material.
[8]
The liquid crystal material is represented by the following general formula (1)
(Where
R ¹¹ is P ¹¹ —Sp ¹¹ —, hydrogen, or alkyl having 1 to 20 carbons, and any —CH ₂ — in the alkyl is —O—, —S—, —COO—, —OCO. -, -CH = CH-, -CF = CF-, or -C≡C- may be substituted, and any hydrogen in the alkyl group may be replaced by halogen;
P ¹¹ represents a polymerizable group;
Sp ¹¹ represents a single bond or a spacer group;
R ^{12 is,} P 12 ^{-Sp 12} -, hydrogen, halogen, -CN, -N = C = O , -N = C = S, -CF 3, be -OCF ₃ or alkyl of 1 to 3 carbon atoms, Any —CH ₂ — in the alkyl may be replaced by —O—, —S—, —COO—, or —OCO—, and any —CH ₂ CH ₂ — in the alkyl is —CH═CH—, —CF═CF—, or —C≡C— may be replaced, any hydrogen in the alkyl may be replaced with a halogen, and —CH ₃ in the alkyl is — May be replaced by CN;
P ¹² represents a polymerizable group;
Sp ¹² represents a single bond or a spacer group;
A ^{11 to} A ¹⁵ are each independently a 5- to 8-membered ring or a condensed ring having 9 or more carbon atoms, and any hydrogen in these rings is replaced by halogen, alkyl having 1 to 5 carbon atoms, or halogenated alkyl. Any —CH ₂ — in the alkyl having 1 to 5 carbon atoms or halogenated alkyl may be replaced by —O—, —S—, or —NH—, and —CH— _2- may be replaced by -O-, -S-, or -NH-, and -CH = in the ring may be replaced by -N =;
Z ^{11 to} Z ¹⁴ are each independently a single bond or alkylene having 1 to 8 carbon atoms, and any —CH ₂ — in the alkylene is —O—, —S—, —COO—, —OCO—, — CSO-, -OCS-, -N = N-, -CH = N-, -N = CH-, -N (O) = N-, or -N = N (O)- Any —CH ₂ CH ₂ — in the alkylene may be replaced with —CH═CH—, —CF═CF—, or —C≡C—, and any hydrogen in the alkylene is replaced with a halogen. May be
n ¹¹ ~n ¹³ is independently 0 or 1)
The capacitor | condenser in any one of [1]-[7] containing the compound represented by these.
[9]
In the general formula (1), n ¹¹ + n ¹² + n ¹³ is 2 or 3, A ^{11 to} A ¹⁴ are selected from the group consisting of the following (A-1) to (A-5), and A ¹⁵ is , (A-1) to (A-3), and the total number of halogen atoms in A ^{11 to} A ¹⁵ is 6 or more, the capacitor according to [8].
[10]
The capacitor according to [8] or [9], wherein the liquid crystal material contains at least one compound selected from the group consisting of compounds represented by the following formulas (2) and (3).
(In the formula (2), R ²¹ is alkyl having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkoxy having 1 to 11 carbons, and Z ²¹ and Z ²² are independently a single bond, -COO-, or _-CF 2 is a ^{O-, X 21} is fluorine, chlorine, -CF ₃ or -OCF ^_3,, L 21 ^{~L 23} is hydrogen or, independently, fluorine,
In the formula (3), R ³¹ is alkyl having 1 to 12 carbons or alkoxyalkyl having 1 to 11 carbons, and Z ³¹ and Z ³² are independently a single bond, —COO—, or —CF ₂ O. -, X ³¹ is fluorine, chlorine, -CF ₃ , or -OCF ₃ , and L ^{31 to} L ³⁴ are independently hydrogen or fluorine. )
[11]
30% by weight or more of the compound represented by the formula (3) in which the total number of halogen atoms in X ³¹ and L ^{31 to} L ³⁴ is 4 or more and / or X ²¹ and L ²¹ ~L total number of halogen atoms in the ²³ contains more than 30% by weight of the compound represented by the is formula (2) two or more, capacitor according to [10].
[12]
The capacitor according to any one of [1] to [11], wherein a spacer is sandwiched between the pair of electrodes and the liquid crystal material is injected.
[13]
The capacitor according to any one of [1] to [12], further including a collecting electrode.

  The capacitor according to one embodiment of the present invention is a liquid crystal material that expresses a specific liquid crystal phase, and uses the liquid crystal material having fluidity in the specific liquid crystal phase, which eliminates the problem of being vulnerable to vibration and impact. The Further, according to one embodiment of the present invention, a capacitor having a high energy density and a high output density can be realized.

It is a schematic diagram of a capacitor according to one embodiment of the present invention. 3 is a POM (polarized light microscope) image of a liquid crystal material used for the capacitor according to one embodiment of the present invention. It is a schematic diagram of a capacitor according to one embodiment of the present invention. It is a dielectric relaxation spectrum figure of the liquid-crystal material used for the capacitor | condenser which concerns on 1 aspect of this invention. It is a SHG light intensity spectrum figure of the liquid-crystal material used for the capacitor | condenser which concerns on 1 aspect of this invention. It is a SHG light intensity spectrum figure of the conventional organic material. It is a SHG light intensity spectrum figure of the liquid-crystal material used for the capacitor | condenser which concerns on 1 aspect of this invention. 4 is a graph showing a relationship between a concentration of a compound contained in a liquid crystal material used for a capacitor according to one embodiment of the present invention and a dielectric constant. It is a graph which shows the switching current response characteristic of the capacitor concerning one mode of the present invention.

In this specification,
“Liquid crystal compound” represents an organic compound having a mesogen moiety and is not limited to an organic compound that exhibits a liquid crystal phase. Specifically, it is a general term for organic compounds that exhibit a liquid crystal phase such as a nematic phase and a smectic phase, and organic compounds that do not have a liquid crystal phase but are useful as components of a liquid crystal composition.
“Liquid crystal medium” is a general term for a composition that exhibits a liquid crystal phase or a composite of the composition and another material.
“Liquid crystal material” is a general term for liquid crystal compounds and liquid crystal media.
“Specific liquid crystal phase” refers to another phase (for example, isotropic phase) of liquid crystal material having the same intensity of SHG (Second harmonic generator) light, or 5CB (4-pentyl-4) It is an extremely large phase compared to other general liquid crystal materials such as' -cyanobiphenyl). In this phase, a large dielectric constant of 100 or more is exhibited, and the temperature characteristic of the dielectric constant becomes gentle. In the present specification, the “specific liquid crystal phase” may be referred to as “Sandy phase”. The term Sandy phase is a coined word derived from its characteristic polarization microscope image. Specifically, high intensity SHG light can be observed in a specific liquid crystal phase (Sandy phase). A liquid crystal material in a specific liquid crystal phase has fluidity.
An “element” is an element using a liquid crystal material. The “element” is an element having a liquid crystal material exhibiting a dielectric constant of 100 or more, preferably 1000 or more at a temperature at which a specific liquid crystal phase is developed, and the liquid crystal material has a temperature at which the specific liquid crystal phase is developed. The device further includes a configuration for applying a voltage. Further, the “element” may be referred to as “liquid crystal element”.
A “capacitor” is an element using a liquid crystal material, and stores and discharges charges. The capacitor may be referred to as a capacitor.
“Dielectric constant” represents a dimensionless relative dielectric constant.
The “nematic phase” includes a cybotactic nematic phase in addition to the nematic phase.

  In this specification, “liquid crystal compound”, “liquid crystal composition”, and “liquid crystal element” may be abbreviated as “compound”, “composition”, and “element”, respectively. The upper limit temperature of the liquid crystal phase is a liquid crystal phase-isotropic phase transition temperature, and the “phase transition temperature” may be simply abbreviated as “clearing point” or “upper limit temperature”. The lower limit temperature of the liquid crystal phase may be simply abbreviated as “lower limit temperature”.

  In this specification, unless otherwise specified, the amount of a compound expressed as a percentage is a weight percentage (% by weight) based on the total amount of the composition.

In the present specification, “alkyl” may be linear or branched, and specific examples thereof include —CH ₃ , —C ₂ H ₅ , —C ₃ H ₇ , —C ₄ H ₉ , —C ₅ H _{11. , -C 6 H 13, -C 7} H 15, -C 8 H 17, -C 9 H 19, -C 10 H 21, include _-C 11 _{H 23} or _-C 12 _{H 25,.} Specific examples of “alkyl” include —C ₁₃ H ₂₇ , —C ₁₄ H ₂₉ , —C ₁₅ H ₃₁ , —C ₁₆ H ₃₃ , —C ₁₇ H ₃₅ , —C ₁₈ H ₃₇ , —C _19. H ₃₉ , or —C ₂₀ H _{41 and the} like can be mentioned.

In the present specification, “alkenyl” may be linear or branched, and specific examples include —CH═CH ₂ , —CH═CHCH ₃ , —CH ₂ CH═CH ₂ , —CH═CHC ₂ H _{5. , -CH 2 CH = CHCH 3,} - (CH 2) 2 -CH = CH 2, -CH = CHC 3 H 7, -CH 2 CH = CHC 2 H 5, - (CH 2) 2 -CH = CHCH 3 Or — (CH ₂ ) ₃ —CH═CH ₂ . Specific examples of “alkenyl” include — (CH ₂ ) ₄ —CH═CH ₂ , — (CH ₂ ) ₅ —CH═CH ₂ , — (CH ₂ ) ₆ —CH═CH ₂ , — (CH ₂ ) ₇ -CH═CH ₂ , — (CH ₂ ) ₈ —CH═CH ₂ , — (CH ₂ ) ₉ —CH═CH ₂ , or — (CH ₂ ) ₁₀ —CH═CH _{2 and the} like.

In the present specification, “alkynyl” may be linear or branched, and specific examples thereof include —C≡CH, —C≡CCH ₃ , —CH ₂ C≡CH, —C≡CC ₂ H ₅ , — CH ₂ C≡CCH ₃ , — (CH ₂ ) ₂ —C≡CH, —C≡CC ₃ H ₇ , —CH ₂ C≡CC ₂ H ₅ , — (CH ₂ ) ₂ —C≡CCH ₃ , or — C≡C (CH ₂ ) ₅ is mentioned.

In the present specification, “alkoxy” may be linear or branched, and specific examples thereof include —OCH ₃ , —OC ₂ H ₅ , —OC ₃ H ₇ , —OC ₄ H ₉ , —OC ₅ H _11. , _-OC 6 _{H 13} and _{-OC 7 H 15, -OC 8 H} 17, -OC 9 H 19, -OC 10 H 21 , or _-OC 11 _{H 23,} and the like.

In the present specification, “alkoxyalkyl” may be linear or branched, and specific examples thereof include —CH ₂ OCH ₃ , —CH ₂ OC ₂ H ₅ , —CH ₂ OC ₃ H ₇ , — (CH _2). ) ₂ -OCH ₃ , — (CH ₂ ) ₂ —OC ₂ H ₅ , — (CH ₂ ) ₂ —OC ₃ H ₇ , — (CH ₂ ) ₃ —OCH ₃ , — (CH ₂ ) ₄ —OCH ₃ , or _- it is _(CH 2) 5 -OCH ₃ like. Specific examples of “alkoxyalkyl” include — (CH ₂ ) ₆ —OCH ₃ , — (CH ₂ ) ₇ —OCH ₃ , — (CH ₂ ) ₈ —OCH ₃ , — (CH ₂ ) ₉ —OCH. _3, or _{- (CH} 2) 10 -OCH _3, and the like.

In the present specification, “alkenyloxy” may be linear or branched. Specific examples thereof include —OCH ₂ CH═CH ₂ , —OCH ₂ CH═CHCH ₃ , and —OCH ₂ CH═CHC ₂ H _5. Is mentioned.

  In the present specification, specific examples of “halogen” include fluorine, chlorine, bromine, and iodine.

  In the present specification, specific examples of the “polymerizable group” include an acryl group, a methacryl group, a vinyloxy group, an isocyanate group, an isothiocyanate group, an epoxy group, an aziridine group, an azlactone group, a chloro-s-triazine group, or Examples thereof include, but are not limited to, a sulfonyl group of β-chloroethylami.

In the present specification, specific examples of the “spacer group” include —C ₂ H ₄ —, —C ₃ H ₆ —, —C ₄ H ₈ —, —C ₅ H ₁₀ —, —C ₆ H ₁₂ —, —C ₇ H ₁₄ —, —C ₈ H ₁₆ —, —C ₉ H ₁₈ —, —C ₁₀ H ₂₀ — and the like, or a group in which one or more CH _{2 of} these groups are replaced by oxygen or COO However, it is not limited to this. However, oxygen atoms are not adjacent.

  Hereinafter, a capacitor according to one embodiment of the present invention and a liquid crystal material used as a dielectric of the capacitor will be described in more detail with reference to the drawings.

1. Capacitor A capacitor according to one embodiment of the present invention includes a pair of electrodes disposed to face each other and a dielectric disposed between the pair of electrodes, and the dielectric exhibits a specific liquid crystal phase. It includes a liquid crystal material that is SHG active at temperature and exhibits a dielectric constant of 100 or higher.

In the capacitor according to one embodiment of the present invention, the electrode is a conductor having a relatively large specific surface area, and is preferably a porous conductor. Here, the specific surface area is preferably 960 m ² / g or more. In the capacitor according to one embodiment of the present invention, the liquid crystal material is impregnated in the porous conductor. The capacitor according to one embodiment of the present invention is a capacitor that is operated at a temperature at which a liquid crystal material containing at least one compound selected from the compounds represented by the following formulas (1) to (3) exhibits a specific liquid crystal phase. It is. In addition, the capacitor according to one embodiment of the present invention may be operated in a state where the composite material develops a phase other than the specific liquid crystal phase. The capacitor according to one embodiment of the present invention further includes a separator, a spacer, and a collecting electrode as necessary.

2. Liquid crystal material The liquid crystal material used as the dielectric of the capacitor according to one embodiment of the present invention exhibits one or more of the following characteristics.
(A) at a temperature that develops a specific liquid crystal phase, exhibits a high dielectric constant of 100 or more in a wide range of the frequency (measurement frequency) of the alternating voltage applied to the liquid crystal material, preferably exhibits a high dielectric constant of 1000 or more, High dielectric constant up to 10,000 or more.
(B) A high dielectric constant of 1000 or more in a temperature range of −40 to room temperature to 150 ° C., preferably any temperature of −30 to 100 ° C., more preferably a temperature range in which a specific liquid crystal phase is developed. Show.
(C) The relaxation frequency in the specific liquid crystal phase on the low temperature side is higher than the relaxation frequency in the nematic phase that appears on the high temperature side than the specific liquid crystal phase. In general, a normal liquid crystal material has a lower response frequency due to an increase in viscosity at a low temperature. Therefore, the relaxation frequency on the low temperature side is lower than the relaxation frequency on the high temperature side.
(D) In a state where a specific liquid crystal phase is developed, a high positive dielectric anisotropy Δε (ε _para −ε _perp ) is exhibited.

  The liquid crystal material used as the dielectric of the capacitor according to one embodiment of the present invention expresses SHG in a bulk (a main body portion that is not in contact with the interface). Considering that the requirement for the development of SHG is asymmetry of the system, the liquid crystal material that may exhibit SHG has asymmetry in a specific liquid crystal phase. Thus, compared to a general liquid crystal material, the liquid crystal material used for the capacitor according to one embodiment of the present invention has more molecules in a specific liquid crystal phase and a larger number of parallel associations in molecules (a molecular dipole). It is presumed that the moment direction is aligned in substantially the same direction), and as a result, an extremely large dielectric constant is expressed.

More specifically, the liquid crystal material used for the capacitor according to one embodiment of the present invention is a liquid crystal material that expresses a specific liquid crystal phase, and has a dielectric constant of 100 at a temperature at which the specific liquid crystal phase is expressed. That's it. The liquid crystal material used for the capacitor according to one embodiment of the present invention includes a compound represented by the following general formula (1), and includes 30% by weight or more, preferably 50% by weight or more, and more preferably 80% by weight or more.

Wherein ^{(1), R 11 is,} P 11 ^{-Sp 11} -, hydrogen, or alkyl having 1 to 20 carbon atoms, any _-CH 2 in the alkyl - is, -O -, - S-, —COO—, —OCO—, —CH═CH—, —CF═CF—, or —C≡C— may be substituted, and any hydrogen in the alkyl group may be substituted with a halogen. Here, P ¹¹ represents a polymerizable group, and Sp ¹¹ represents a single bond or a spacer group. Preferably, R ¹¹ is alkyl having 1 to 7 carbons, and any —CH ₂ — in the alkyl may be replaced by —O—, —CH═CH—, or —C≡C—. Well, any hydrogen in the alkyl group may be replaced with a halogen.

R ^{12 is,} P 12 ^{-Sp 12} -, hydrogen, halogen, -CN, -N = C = O , -N = C = S, -CF 3, be -OCF ₃ or alkyl of 1 to 3 carbon atoms, Any —CH ₂ — in the alkyl may be replaced by —O—, —S—, —COO—, or —OCO—, and any —CH ₂ CH ₂ — in the alkyl is —CH═CH—, —CF═CF—, or —C≡C— may be replaced, any hydrogen in the alkyl may be replaced with a halogen, and —CH ₃ in the alkyl is — It may be replaced with CN. Here, P ¹² represents a polymerizable group, and Sp ¹² represents a single bond or a spacer group. Preferably, R ¹² is halogen, —CN, —N═C═S, —CF ₃ , —OCF ₃ , or alkyl having 1 to 3 carbon atoms, and any hydrogen in the alkyl is replaced by halogen. May be.

A ^{11 to} A ¹⁵ are each independently a 5- to 8-membered ring or a condensed ring having 9 or more carbon atoms, and any hydrogen in these rings is replaced with halogen, alkyl having 1 to 5 carbons, or alkyl halide. May be. Arbitrary —CH ₂ — in the alkyl having 1 to 5 carbon atoms or halogenated alkyl may be replaced by —O—, —S—, or —NH—, and —CH ₂ — in the ring is — O—, —S—, or —NH— may be substituted, and —CH═ of the ring may be substituted with —N═. Preferably, A ^{11 to} A ¹⁴ are rings selected from the group consisting of the following (A-1) to (A-5), and A ¹⁵ is from the following (A-1) to (A-3): A ring selected from the group consisting of Furthermore, the compound of the above general formula (1) in which the total number of halogen atoms in A ^{11 to} A ¹⁵ is 6 or more has a relatively large dielectric anisotropy. The liquid crystal material to be contained easily develops a specific liquid crystal phase. In the dielectric of the capacitor according to one embodiment of the present invention, the compound of the general formula (1) in which the total number of halogen atoms in A ^{11 to} A ¹⁵ is 6 or more is 30 with respect to the total weight of the liquid crystal material. A liquid crystal material containing not less than wt%, preferably not less than 50 wt%, more preferably not less than 80 wt% is included.

Z ^{11 to} Z ¹⁴ are each independently a single bond or alkylene having 1 to 8 carbon atoms, and any —CH ₂ — in the alkylene is —O—, —S—, —COO—, —OCO—, -CSO-, -OCS-, -N = N-, -CH = N-, -N = CH-, -N (O) = N-, or -N = N (O)-may be substituted. Any —CH ₂ CH ₂ — in the alkylene may be replaced with —CH═CH—, —CF═CF—, or —C≡C—, and any hydrogen may be replaced with a halogen. Good. Preferably, Z ^{11 to} Z ¹⁴ are independently a single bond, —COO—, or —CF ₂ O—. More preferably, at least one of Z ^{11 to} Z ¹⁴ is —COO— or —CF ₂ O—.

N ^{11 to} n ¹³ are independently 0 or 1, but preferably the total of n ^{11 to} n ¹³ (n ¹¹ + n ¹² + n ¹³ ) is 2 or 3.

The liquid crystal material used for the capacitor according to one embodiment of the present invention contains 30% by weight or more, preferably at least one compound selected from the group consisting of compounds represented by the following formulas (2) and (3), It may be contained in an amount of 50% by weight or more, more preferably 80% by weight or more.

In Formula (2), R ²¹ is alkyl having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkoxy having 1 to 11 carbons, and Z ²¹ and Z ²² are independently a single bond, —COO— or —CF ₂ O—, X ²¹ is fluorine, chlorine, —CF ₃ , or —OCF ₃ , and L ^{21 to} L ²³ are independently hydrogen or fluorine. In Formula (3), R ³¹ is alkyl having 1 to 12 carbons or alkoxyalkyl having 1 to 11 carbons, and Z ³¹ and Z ³² are independently a single bond, —COO—, or — CF ₂ O—, X ³¹ is fluorine, chlorine, —CF ₃ , or —OCF ₃ , and L ^{31 to} L ³⁴ are independently hydrogen or fluorine.

Further, the compound of the above formula (2) in which the total number of halogen atoms in X ²¹ and L ^{21 to} L ²³ is 2 or more includes such a compound because the dielectric anisotropy becomes relatively large. The liquid crystal material easily develops a specific liquid crystal phase. Similarly, the compound of the above formula (3) in which the total number of halogen atoms in X ³¹ and L ^{31 to} L ³⁴ is 4 or more has a relatively large dielectric anisotropy. The liquid crystal material to be contained easily develops a specific liquid crystal phase. In the dielectric of the capacitor according to one embodiment of the present invention, the compound of the above formula (2) in which the total number of halogen atoms in X ²¹ and L ^{21 to} L ²³ is 2 or more is 30 wt% or more, preferably 50 It contains a liquid crystal material containing at least 80% by weight, more preferably 80% by weight. In the capacitor dielectric according to one embodiment of the present invention, the compound of the above formula (3) in which the total number of halogen atoms in X ³¹ and L ^{31 to} L ³⁴ is 4 or more is preferably 30% by weight or more. Includes a liquid crystal material containing 50 wt% or more, more preferably 80 wt%. The dielectric of the capacitor according to one embodiment of the present invention includes the compound of the above formula (2) in which the total number of halogen atoms in X ²¹ and L ^{21 to} L ²³ is 2 or more, and X ³¹ and L ³¹ to total number of halogen atoms in L ³⁴ comprises a liquid crystal material, each containing 30% or more by weight of a compound of 4 or more in which the above formula (3). However, the total weight of both compounds does not exceed 100% by weight with respect to the total weight of the liquid crystal material.

In addition, the liquid crystal material used for the capacitor according to one embodiment of the present invention may include a polymer having no mesogen moiety and / or a polymer having a mesogen moiety. Further, as the polymer having a mesogen moiety, at the end as R ¹¹ P ^{11 -Sp 11 -} compounds represented by the general formula (1) may contain a polymer which Deki by polymerization with. Polymerizable group P ¹¹ is, for example, acrylic group, methacrylic group, vinyl group, isocyanate group, isothiocyanate group, epoxy group, aziridine group or an azlactone group, or the like. The polymer may contain a polymerization initiator, a curing agent, a catalyst, a stabilizer, a dichroic dye, a photochromic compound, or the like as long as the effect of the liquid crystal material is not impaired.

  In addition, a composite material that can be used as a dielectric of the capacitor according to one embodiment of the present invention is a composite material of at least one of the compounds represented by the above formulas (1) to (3) and a polymer compound. For example, a polymer network may be formed in the liquid crystal material. The composite material can be obtained by dissolving a polymer and a liquid crystal material in a solvent and evaporating the solvent. Moreover, it can obtain by cooling, after melt | dissolving and mixing a high molecular compound and liquid crystal material, preferably at the temperature which expresses an isotropic phase, without using a solvent. In addition, the composite material can be obtained by adding and mixing a monomer into the liquid crystal material and then polymerizing the monomer with heat or light. In this case, the composite material may further contain a polymerization initiator and the like. Further, if necessary, the composite material is subjected to pressure molding treatment or poling treatment (polarization treatment) applying a high voltage (several kV) to polarize the liquid crystal material (compound) in the composite material. The directions may be aligned in advance. The composite material may be obtained by any manufacturing method, and is not particularly limited to those formed by the manufacturing methods listed here.

3. Electrodes A pair of electrodes used in the capacitor according to one embodiment of the present invention, in which the dielectric is disposed between them, is not particularly limited as long as the specific surface area is large, but a porous conductor is used. it can. Specific examples of such a porous conductor include an electrode made of a metal material (film forming metal) such as tantalum, niobium, aluminum, titanium, zirconium, magnesium, hafnium, or an activated carbon woven fabric. In the capacitor according to one embodiment of the present invention, a porous conductor impregnated with the liquid crystal material used as a dielectric may be used as an electrode (also referred to as a polarizable electrode). In the capacitor according to one embodiment of the present invention, a metal plate provided with conductive nanostructures such as activated carbon fine particles or carbon nanotubes or fullerenes may be used as an electrode.

  Porous conductors generally include macropores having a pore size of about 50 nm or more, mesopores having a pore size of about 2 nm to about 50 nm, and micropores having a pore size of about 2 nm or less. When a porous conductor is used as an electrode, the pores of the porous conductor (especially macropores and mesopores) can be changed so that the molecules of the liquid crystal material can penetrate into the pores and change their orientation according to the applied electric field. The size is preferably larger than the molecules of the liquid crystal material. For example, since the length of the long axis of one molecule of the compound DIO-3, which will be described later, is about 5 nm, when a porous conductor is used as an electrode, the ratio of pores having a size exceeding 5 nm is large. It is better to select.

  The capacitor according to one embodiment of the present invention may further include a collector electrode, and the collector electrode is a metal plate or a metal foil such as gold, silver, copper, or aluminum having a relatively large electrical conductivity. It may be used.

  FIG. 1 is a schematic diagram of a capacitor 10 according to one embodiment of the present invention using an activated carbon woven fabric 11 as an electrode. Specifically, the capacitor 10 includes a pair of activated carbon woven fabrics 11 (polarizable electrodes) impregnated with a liquid crystal material (for example, a compound DIO-3 described later), and bead spacers 12 ( Spacer), an electrolytic solution 13 of the liquid crystal material, and an aluminum foil 14 (collector electrode) connected to the activated carbon woven fabric 11 respectively. FIG. 1B is a schematic diagram in which a part of the capacitor 10 is enlarged, and an arrow in the drawing represents a polarization direction of a liquid crystal material (for example, compound DIO-3) molecule when a voltage is applied to the capacitor. Since the liquid crystal material enters the plurality of holes 11a formed in the activated carbon woven fabric 11, the specific surface area in contact with the liquid crystal material is relatively large. In FIG. 1B, the spacer 12 is omitted.

The capacitor 10 is not limited, but may be manufactured by the following method. First, an activated carbon woven fabric (for example, UEDA ENVIRONMENTAL SOLUTIONS, part number “UCG-CPT” (BET Surface Area: 1,727.5948 m ² / g, Langmuir Surface Area: 2,338.5818 m ² / g, t-Plot Micropore (Area: 997.9296 m ² / g) is cut into an appropriate size (for example, a 20 mm circle), and then the activated carbon woven fabric is heated to a temperature equal to or higher than the melting temperature under vacuum (for example, 100 ° C. when using Compound DIO-3 described later) After immersing in the heated liquid crystal material solution as described above, the pressure is returned to normal pressure while maintaining the temperature, and the activated carbon woven fabric is pressurized to infiltrate the liquid crystal material solution into the activated carbon woven fabric. Then, a pair of polarizable electrodes is prepared from the activated carbon woven fabric impregnated with a liquid crystal material, for example, a synthetic resin bead spacer is used as the spacer, and the distance between the electrodes is kept constant, and the activated carbon woven fabric is made of aluminum. Attach a collector electrode such as foil and The capacitor 10 is produced by housing it in an outer can made of stainless steel, etc. The collector electrode is connected to a charging power source and / or a discharging load via a wiring. Under pressure, a solution of a liquid crystal material is further injected into the capillary as a dielectric, thus producing a capacitor using the liquid crystal material (FIG. 1).

  Further, one embodiment of the present invention is a capacitor used as a liquid crystal material, a temperature sensor that detects the temperature of the capacitor, and temperature control means that controls the temperature of the capacitor (for example, a radiator, a fin, a heater, a water cooler, a heat insulating material) A power storage module including any combination of materials and heat insulating materials. The temperature sensor may be a temperature sensor using a thermocouple, a side temperature resistor, a radiation thermometer, a thermal expansion thermometer, or the like. The temperature control means is based on information from the temperature sensor and exceeds a temperature at which the liquid crystal material exhibits a crystal phase (for example, about 30 ° C. or higher when using the compound DIO-3 described later, preferably a specific liquid crystal It functions to keep the capacitor at a temperature (30 ° C. to 67 ° C.) that develops the phase.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not restrict | limited by these Examples. Unless otherwise specified, “%” means “% by weight”.

[Example 1] (Phase transition temperature of compound DIO-3)
In this example and the following example, R ^{31 of the} compound represented by the above formula (3) is an alkyl group having 3 carbon atoms, L ³³ is hydrogen, Z ³² is a single bond, L ³¹ , L ³² , L ³⁴ , and X ³¹ are fluorine and Z ³¹ is —COO—, and the compound DIO-3 represented by the following formula (4) was used as the liquid crystal material.

Using three types of cells, a non-alignment processing cell, a horizontal alignment processing cell, and a vertical alignment processing cell, the phase transition temperature of the compound DIO-3 was determined by DSC (differential scanning calorimeter DSC1, manufactured by METTLER TOLEDO) and a polarizing microscope. Was identified. The DSC measurement condition is a temperature rising / falling rate of 5 ° C./min (polarized microscope (POM) image in FIG. 2). In FIG. 2, the upper row shows a polarization microscope image using a non-orientation treatment cell, the middle row shows a polarization microscope image using a horizontal alignment treatment cell, and the lower row shows a polarization microscope image using a vertical alignment treatment cell. In the legend of FIG. 2, Cry represents a crystalline phase, Sd represents a Sandy phase, X represents an Unknown phase, and N represents a nematic phase. From the measurement results, the phase transition temperature of Compound DIO-3 was as shown in Table 1 below.

  In the table, “Sandy phase” represents a specific liquid crystal phase. In addition, the compound DIO-3 in the Sandy phase has fluidity. Note that the lower limit temperature (44.1 ° C) at which the Sandy phase appears when the temperature rises is different from the lower limit temperature (30.0 ° C) at which the Sandy phase appears when the temperature falls, because the measurement conditions, impurities contained in the liquid crystal material, or the cell This is considered to be due to, for example, crystallization due to the structure or the like.

[Example 2] (Capacitor 1 / Dielectric relaxation)
In this example, the dielectric relaxation spectrum of compound DIO-3 was measured. The measuring device was a 126096W type dielectric measuring system (manufactured by Toyo Technica Co., Ltd.), and applied a sine wave of 0.1 V to measure the temperature. After reaching the desired temperature, the temperature was maintained at that temperature for 5 minutes, and then the measurement was started. The cell used was a vertical alignment treatment cell manufactured by EHC, the cell thickness (distance between electrodes) was 10 μm, the surface area of a pair of opposing electrodes was 1 cm ² , and the concentration of compound DIO-3 in the cell was 100% by weight. is there. Here, as shown in FIG. 3, the vertical alignment processing cell 20 includes a substrate 22, an electrode (ITO) 23 formed on the substrate 22, a polyimide vertical alignment film 24 formed on the electrode 3, It is the cell 20 containing the compound DIO-3 (21). The vertical alignment processing cell 20 is an embodiment of a capacitor including the compound DIO-3 (21) as a dielectric disposed between the pair of electrodes 23.

The measurement result of the dielectric relaxation characteristic of compound DIO-3 is shown in FIG. In FIG. 4, the vertical axis represents the dielectric constant ε and represents a range of 10 ⁻³ (1.0E-03) to 10 ⁵ (1.0E + 05), and the horizontal axis represents the frequency (measurement frequency) of the AC voltage to be applied ( Hz) representing a range of 1 Hz (1.E + 00) to 10 ⁷ Hz (1.E + 07), and legend numbers (30 to 120) represent measurement temperatures (° C.).

  It exhibits a very large dielectric constant of about 10,000 at 1 Hz (1.E + 00) to 1 KHz (1.E + 03) in the temperature range of 48 ° C. to 66 ° C. within the temperature range in which the Sandy phase appears. The dielectric constant gradually decreased on the higher frequency side, but a large dielectric constant of about 1000 was exhibited even at 10 KHz (1.E + 04). Further, in the temperature range (48 ° C. to 66 ° C.), especially in the range of 1 Hz (1.E + 00) to 10 KHz (1.E + 04), the plots for the respective temperatures are overlapped, and the dielectric constant It was found that the temperature dependence was small.

[Example 3] (SHG spectrum of compound DIO-3)
In this example, the SHG spectrum of the compound DIO-3 during homeotropic alignment (7 V applied) was measured (polarization condition pp). The measuring apparatus is a nonlinear optical material evaluation system manufactured by Tokyo Instruments, and the cell used is the same vertical alignment processing cell (cell thickness 10 μm) manufactured by EHC as in Example 2. The results are shown in FIG. In FIG. 5, the vertical axis represents the SHG intensity (arbitrary unit (au)), the horizontal axis represents the incident angle (°) of the laser beam, and represents a range of −50 ° to 50 °. ~ 65) represents the measurement temperature (° C).

  As shown in FIG. 5, extremely high SHG intensity was exhibited in the temperature range of 45 ° C. to 65 ° C. in the temperature range in which the Sandy phase was developed. In particular, for example, when comparing the SHG intensity at an incident angle of 30 °, the SHG intensity in the temperature range (45 ° C. to 65 ° C.) is 2 in comparison with the SHG intensity in the temperature range (25 ° C. to 40 ° C.) at which the crystal phase appears. The value was 10 times or more or 10 to 20 times or more larger. That is, it strongly suggests that there is a parallel association of the compound DIO-3 molecules in the Sandy phase.

  Here, as a comparative example, FIG. 6 shows an SHG spectrum of an empty cell of the same vertical alignment treatment cell manufactured by EHC as in Example 2, and 5CB (4-pentyl-) which is a conventional liquid crystal material sealed in the empty cell. 4'-cyanobiphenyl) shows the SHG spectrum. The measurement was performed using the same apparatus and the same measurement conditions as those used to generate the data of FIG. In FIG. 6, the vertical axis represents the SHG intensity (arbitrary unit (au)), the horizontal axis represents the incident angle (°) of the laser beam and represents a range of −50 ° to 50 °, and numbers 50 and 25 in the legend. Represents the measurement temperature (° C.). As shown in FIG. 6, for example, when comparing the SHG intensity at an incident angle of 30 °, the SHG intensity (about 250) of the compound DIO-3 is higher than that of 5CB (about 25 ° C. and 50 ° C. is about 10 or less). It turned out to be extremely large.

Example 4 (SHG spectrum of Compound DIO-3)
In this example, SHG spectrum measurement was performed when the compound DIO-3 was in a substantially random orientation (no voltage applied). The measuring apparatus is a non-linear optical material evaluation system manufactured by Tokyo Instruments, and the cell used is a vertical alignment processing cell (cell thickness 10 μm) manufactured by EHC, the same as in Example 2. The results are shown in FIG. The numbers 65 to 120 in the legend of FIG. 7 represent the measurement temperature (° C.).

  The reason why the SHG spectrum at 65 ° C. shown in FIG. 5 in Example 3 and the SHG spectrum at 65 ° C. in FIG. 7 differ greatly is that when no voltage is applied as in this Example, compound DIO-3 is perpendicular in the Sandy phase. This is probably because it is not oriented and has a substantially random orientation. As shown in FIG. 7, the SHG spectrum at 65 ° C. that expresses the Sandy phase takes a larger value than the SHG spectrum on the high temperature side (82 ° C., 120 ° C.) that is not the Sandy phase. It was strongly suggested that there was a parallel meeting. It was also found that the SHG light intensity specifically increased in the Sandy phase.

[Example 5] (Condenser 2 / Concentration characteristics of compound in liquid crystal material)
In this example, similarly to Example 2, a capacitor using a vertical alignment processing cell including a liquid crystal material containing the compound DIO-3 as a dielectric was produced.
While changing the concentration of the compound DIO-3 in the liquid crystal material in the capacitor, the relationship between the dielectric constant (ε) and the temperature (° C.) of the liquid crystal material was examined (FIG. 8). Further, the capacitance of the capacitor at 64 ° C. was measured. The experimental conditions of this example are the same as those of Example 2 except that the measurement frequency was fixed at 1000 Hz. The liquid crystal material of this example is composed of the compound DIO-3 and a general liquid crystal composition J having a dielectric constant of about 5.
Here, in the liquid crystal composition J, the liquid crystal compound represented by the following chemical formula (5) is 25% by weight, the liquid crystal compound represented by the chemical formula (6) is 25% by weight, and the liquid crystal compound represented by the chemical formula (7) is 50% by weight. Including.

  In FIG. 8, “DIO / J” represents a ratio by weight% of the compound DIO-3 (DIO) contained in the liquid crystal material in the vertical alignment treatment cell (capacitor) and the general liquid crystal composition J. In FIG. 8, black circles are measurement data of a sample in which the liquid crystal material contains 100% by weight of compound DIO-3. Similarly, the white diamond is measurement data of a sample in which the liquid crystal material contains 95% by weight of the compound DIO-3 and 5% by weight of the liquid crystal composition J. The black triangles are measurement data of a sample in which the liquid crystal material contains 93% by weight of the compound DIO-3 and 7% by weight of the liquid crystal composition J. The asterisk indicates that the liquid crystal material contains 91% of the compound DIO-3. It is the measurement data of the sample containing 9% by weight of the liquid crystal composition J by weight%.

From the results shown in FIG. 8, when the compound DIO-3 and the liquid crystal composition J having a relatively small dielectric constant are included in the liquid crystal material, the concentration of the compound DIO-3 in the liquid crystal material is 91% by weight or more. Then, it was found that the dielectric constant was 100 or more at least at any temperature or temperature range. When the liquid crystal material contains the compound DIO-3 and the liquid crystal composition J having a relatively small dielectric constant, a sample having a concentration of the compound DIO-3 in the liquid crystal material of less than 93% by weight was used. In this case, since the dielectric constant is relatively lowered on the higher temperature side (about 30 ° C. or higher) than the temperature at which the crystal phase appears, when the liquid crystal material containing the compound DIO-3 is used for the capacitor, the total weight of the liquid crystal material Thus, a compound containing more than 93% by weight, preferably 95% by weight or more of compound DIO-3 may be used.
Further, the capacitance value at 64 ° C. of the capacitor containing 100% by weight of the compound DIO-3 in the liquid crystal material was 1.15 × 10 ⁻⁶ F (1.15 μF).

[Example 6] (Capacitor 3 / Charge / discharge characteristics, ferroelectric characteristics)
In this example, using a liquid crystal property parameter evaluation apparatus (product number: VHRION-CV-VT) manufactured by Toyo Technica Co., Ltd., how fast the capacitor produced in Example 5 can be charged and discharged was examined. Specifically, while maintaining the capacitor at 60 ° C., the voltage of the triangular wave applied to the capacitor is changed to 0V to 10V, 10V to 0V, 0V to −10V, and −10V to 0V every 0.25 seconds. Switching, the switching current response characteristic of the capacitor was examined (FIG. 9). As the liquid crystal material of the capacitor, a material containing 100% by weight of the compound DIO-3 was used. As shown in FIG. 9, it was found that the current response of the capacitor was fast and could sufficiently cope with rapid charge / discharge. In FIG. 9, peak A is a peak due to the polarization direction being aligned with the electric field direction, peak B is a peak due to the macroscopic random or antiparallel polarization direction, and peak C is a polarization direction. The peak due to alignment in the electric field direction (the polarization direction is opposite to the case of peak A) and the peak D are considered to be peaks due to macroscopic random or antiparallel polarization directions. From this, it was also found that the compound DIO-3, which is a liquid crystal material, changes the direction of polarization according to the external electric field and exhibits a ferroelectric or antiferroelectric behavior.

  The present invention can be applied to a capacitor using a liquid crystal material that expresses a specific liquid crystal phase.

10 Capacitor 11 Activated carbon woven fabric (polarizable electrode)
11a Hole 12 formed in activated carbon woven fabric Liquid crystal material (electrolyte)
13 Bead spacer (spacer)
14 Aluminum foil (collector electrode)
20 Capacitor (Vertical alignment processing cell)
21 Molecule 22 of liquid crystal material 22 Substrate 23 Electrode 24 Vertical alignment film

Claims (13)

A capacitor including a pair of electrodes disposed opposite to each other and a dielectric disposed between the pair of electrodes,
The capacitor, wherein the dielectric includes a liquid crystal material that is SHG active at a temperature at which a specific liquid crystal phase is developed and exhibits a dielectric constant of 100 or more.   The capacitor according to claim 1, wherein the electrode is a porous conductor.   The capacitor according to claim 2, wherein the porous conductor is impregnated with the liquid crystal material.   The capacitor according to any one of claims 1 to 3, wherein a dielectric constant of the liquid crystal material at a temperature at which the specific liquid crystal phase is developed is 1000 or more.   The capacitor according to claim 1, wherein in the specific liquid crystal phase, the liquid crystal material exhibits a ferroelectric or antiferroelectric behavior.   The intensity of SHG light at an incident angle of 30 ° of the liquid crystal material at a temperature at which the specific liquid crystal phase is developed is such that the liquid crystal material has an incident angle of 30 at a temperature at which the liquid crystal material exhibits a phase different from the specific liquid crystal phase. The capacitor according to any one of claims 1 to 5, which is 2 to 10 times or more larger than the intensity of SHG light at °.   The capacitor according to claim 6, wherein the phase different from the specific liquid crystal phase is a crystal phase or an isotropic phase of the liquid crystal material. The liquid crystal material is represented by the following general formula (1)
(Where
R ¹¹ is P ¹¹ —Sp ¹¹ —, hydrogen, or alkyl having 1 to 20 carbons, and any —CH ₂ — in the alkyl is —O—, —S—, —COO—, —OCO. -, -CH = CH-, -CF = CF-, or -C≡C- may be substituted, and any hydrogen in the alkyl group may be replaced by halogen;
P ¹¹ represents a polymerizable group;
Sp ¹¹ represents a single bond or a spacer group;
R ^{12 is,} P 12 ^{-Sp 12} -, hydrogen, halogen, -CN, -N = C = O , -N = C = S, -CF 3, be -OCF ₃ or alkyl of 1 to 3 carbon atoms, Any —CH ₂ — in the alkyl may be replaced by —O—, —S—, —COO—, or —OCO—, and any —CH ₂ CH ₂ — in the alkyl is —CH═CH—, —CF═CF—, or —C≡C— may be replaced, any hydrogen in the alkyl may be replaced with a halogen, and —CH ₃ in the alkyl is — May be replaced by CN;
P ¹² represents a polymerizable group;
Sp ¹² represents a single bond or a spacer group;
A ^{11 to} A ¹⁵ are each independently a 5- to 8-membered ring or a condensed ring having 9 or more carbon atoms, and any hydrogen in these rings is replaced by halogen, alkyl having 1 to 5 carbon atoms, or halogenated alkyl. Any —CH ₂ — in the alkyl having 1 to 5 carbon atoms or halogenated alkyl may be replaced by —O—, —S—, or —NH—, and —CH— _2- may be replaced by -O-, -S-, or -NH-, and -CH = in the ring may be replaced by -N =;
Z ^{11 to} Z ¹⁴ are each independently a single bond or alkylene having 1 to 8 carbon atoms, and any —CH ₂ — in the alkylene is —O—, —S—, —COO—, —OCO—, — CSO-, -OCS-, -N = N-, -CH = N-, -N = CH-, -N (O) = N-, or -N = N (O)- Any —CH ₂ CH ₂ — in the alkylene may be replaced with —CH═CH—, —CF═CF—, or —C≡C—, and any hydrogen in the alkylene is replaced with a halogen. May be
n ¹¹ ~n ¹³ is independently 0 or 1)
The capacitor | condenser of any one of Claims 1-7 containing the compound represented by these. In the general formula (1), n ¹¹ + n ¹² + n ¹³ is 2 or 3, A ^{11 to} A ¹⁴ are selected from the group consisting of the following (A-1) to (A-5), and A ¹⁵ is The capacitor according to claim 8, wherein the capacitor is selected from the group consisting of (A-1) to (A-3), and the total number of halogen atoms in A ^{11 to} A ¹⁵ is 6 or more.
The capacitor according to claim 8 or 9, wherein the liquid crystal material contains at least one compound selected from the group consisting of compounds represented by the following formulas (2) and (3).
(In the formula (2), R ²¹ is alkyl having 1 to 12 carbons, alkenyl having 2 to 12 carbons, or alkoxy having 1 to 11 carbons, and Z ²¹ and Z ²² are independently a single bond, -COO-, or _-CF 2 is a ^{O-, X 21} is fluorine, chlorine, -CF ₃ or -OCF ^_3,, L 21 ^{~L 23} is hydrogen or, independently, fluorine,
In the formula (3), R ³¹ is alkyl having 1 to 12 carbons or alkoxyalkyl having 1 to 11 carbons, and Z ³¹ and Z ³² are independently a single bond, —COO—, or —CF ₂ O. -, X ³¹ is fluorine, chlorine, -CF ₃ , or -OCF ₃ , and L ^{31 to} L ³⁴ are independently hydrogen or fluorine. ) 30% by weight or more of the compound represented by the formula (3) in which the total number of halogen atoms in X ³¹ and L ^{31 to} L ³⁴ is 4 or more and / or X ²¹ and L ²¹ total number of halogen atoms in the ~L ²³ contains a compound represented by the 30 wt% or more larger than 2 equation (2), a capacitor of claim 10.   The capacitor according to claim 1, wherein a spacer is sandwiched between the pair of electrodes, and the liquid crystal material is injected.   Furthermore, the capacitor | condenser of any one of Claims 1-12 containing a collector electrode.