JP7210006B2 - Conductive mixed liquid crystal composition - Google Patents

Description

The present invention relates to a conductive mixed liquid crystal composition, an ion transport method using the same, a liquid crystal material containing the conductive mixed liquid crystal composition, an ion transport layer containing the liquid crystal material, a secondary battery, and a capacitor.

Lithium ion secondary batteries are required to shorten the charging time in order to improve convenience. In recent years, organic materials with high ion conductivity have attracted attention, and organic materials with high ion conductivity have received particular attention as electrolytes for next-generation lithium-ion secondary batteries.

The transport mechanism of lithium ions in conventional organic materials with lithium ion conductivity is between irregularly arranged molecules, so there is a problem with the transport efficiency of lithium ions. Further, there is a demand for a material having excellent lithium ion transportability.

The inventors of the present invention have found that proton transport ability, charge transport ability, and electrical conductivity are improved by utilizing the molecular orientation of the liquid crystal state of a liquid crystal compound having a smectic phase as the liquid crystal phase, and can be applied to these uses. A liquid crystal compound has been proposed (see, for example, Patent Documents 1 to 4, etc.).

JP-A-2002-338585 JP-A-2003-55337 JP-A-2003-144196 Japanese Patent Application Laid-Open No. 2001-351786

In the course of further studies, the present inventor succeeded in designing the molecular structure of a mixed liquid crystal composition that exhibits conductivity at room temperature, and also found a method of transporting ions using this, and an application to secondary batteries and capacitors. , completed the present invention.

Conventional liquid crystal compounds for transporting lithium ions do not start to form liquid crystals unless the temperature reaches a high temperature (for example, 220° C. or higher), so there is a limit to the operating temperature range. If this working temperature range can be extended, especially to the low temperature side, without adversely affecting the ion transport rate, its industrial value should be extremely high.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for transporting ions, which can be expected to shorten the charging time at room temperature when used as an electrolyte for a secondary battery. The present invention also provides a novel conductive mixed liquid crystal composition, a method for transporting ions using the same, a liquid crystal material containing the conductive mixed liquid crystal composition, an ion transport layer containing the liquid crystal material, a secondary battery, and a capacitor. to do.

［式中、
Ｒは、炭素原子数５以上のアルキル基又はアルコキシ基を示す。
Ｂは、分岐を有する炭素原子数６以上のアルキレン基を示す（前記分岐を有する炭素原子数６以上のアルキレン基は、酸素原子又は硫黄原子を介してＡと結合してもよい）。
Ａは、π電子が１２個以上の共役系を含む、窒素原子、酸素原子又は硫黄原子を含んでもよい有機基を示す。
Ｌは、炭素原子数３以上の直鎖アルキレン基を示す（前記炭素原子数３以上の直鎖アルキレン基は、酸素原子又は硫黄原子を介してＡと結合してもよい）。
ｎは２を示す。
ｎ個のＲ、Ｂ、Ａ、及びＬはそれぞれ同一であってもよく、相互に異なっていてもよい。
Ｘは、Ｚｎ^２＋を示す。］
［２］ 下記一般式（１）で表され、ｎが１であり、ＸがＬｉ^＋、Ｎａ^＋、及びＫ^＋からなる群より選択されるイオンである液晶化合物を少なくとも１種、並びに下記一般式（１）で表され、ｎが２又は３であり、ＸがＭｇ^２＋、Ｃａ^２＋、Ｂａ^２＋、Ｚｎ^２＋及びＡｌ^３＋からなる群より選択されるイオンである液晶化合物を少なくとも１種含む導電性混合液晶組成物。

［式中、
Ｒは、炭素原子数５以上のアルキル基又はアルコキシ基を示す。
Ｂは、分岐を有する炭素原子数６以上のアルキレン基を示す（前記分岐を有する炭素原子数６以上のアルキレン基は、酸素原子又は硫黄原子を介してＡと結合してもよい）。
Ａは、π電子が１２個以上の共役系を含む、窒素原子、酸素原子又は硫黄原子を含んでもよい有機基を示す。
Ｌは、炭素原子数３以上の直鎖アルキレン基を示す（前記炭素原子数３以上の直鎖アルキレン基は、酸素原子又は硫黄原子を介してＡと結合してもよい）。
ｎは１、２、又は３を示す。
ｎが２又は３のとき、ｎ個のＲ、Ｂ、Ａ、及びＬはそれぞれ同一であってもよく、相互に異なっていてもよい。
Ｘは、Ｌｉ^＋、Ｎａ^＋、Ｋ^＋、Ｍｇ^２＋、Ｃａ^２＋、Ｂａ^２＋、Ｚｎ^２＋及びＡｌ^３＋からなる群より選択されるイオンを示す。］
［３］ 一般式（１）におけるＲが炭素原子数５以上１２以下のアルコキシ基である、［１］又は［２］に記載の導電性混合液晶組成物。
［４］ 一般式（１）におけるＢが下記一般式（２）で表される、［１］乃至［３］のいずれか一項に記載の導電性混合液晶組成物。

［式中、
Ｒ’は炭素原子数１以上６以下のアルキル基であり、
０≦ｐ≦６であり、
０≦ｑ≦６であり、
＊はＡとの結合を示す。］
［５］ イオン性液晶化合物のＡが、単結合、－ＣＨ＝ＣＨ－、－ＣＨ≡ＣＨ－、－Ｎ＝Ｎ－、－ＣＯＯ－、又は－ＣＨ＝Ｎ－によって連結されていてもよいベンゼン環、チオフェン環、フラン環、ピリジン環、ピリミジン環、ピラジン環、ピロール環、オキサゾール環、チアゾール環、イミダゾール環、ナフタレン環、アントラセン環、キノリン環、カルバゾール環、キナゾリン環、プリン環、インドリジン環、ベンゾチオフェン環、ベンゾフラン環、インドール環、又はアクリジン環を表す、［１］乃至［４］のいずれか一項に記載の導電性混合液晶組成物。
［６］ 一般式（１）におけるＬが下記一般式（３）で表される、［１］乃至［５］のいずれか一項に記載の導電性混合液晶組成物。

［式中、
ｍは１以上８以下の整数であり、
＊はＡとの結合を示す。］
［７］ 一般式（１）で表され、Ｘが、Ｎａ^＋、及びＫ^＋からなる群より選択される少なくとも１種のイオンである液晶化合物、
一般式（１）で表され、Ｘが、Ｍｇ^２＋、Ｃａ^２＋、Ｚｎ^２＋及びＢａ^２＋からなる群より選択される少なくとも１種のイオンである液晶化合物、並びに
一般式（１）で表され、ＸがＡｌ^３＋である液晶化合物
のいずれかと、
一般式（１）で表され、ＸがＬｉ^＋である液晶化合物と、
を含む、［１］乃至［６］のいずれか一項に記載の導電性混合液晶組成物。
［８］ 一対の電極間に、［１］乃至［７］のいずれか一項に記載の導電性混合液晶組成物を挟持すること、及び
前記一対の電極間に電圧を印加すること
を含む、イオンの輸送方法。
［９］ 二次電池の充電のための［８］に記載のイオンの輸送方法。
［１０］ ［１］乃至［７］のいずれか一項に記載の導電性混合液晶組成物を含む、液晶材料。
［１１］ ［１０］に記載の液晶材料を含むイオン輸送層。
［１２］ ［８］に記載のイオンの輸送方法を行う、［１１］に記載のイオン輸送層。
［１３］ 二次電池用である、［１０］に記載の液晶材料。
［１４］ キャパシタの誘電体用である、［１０］に記載の液晶材料。
［１５］ ［１０］に記載の液晶材料を含む二次電池。
［１６］ ［１０］に記載の液晶材料を含むキャパシタ。
［１７］ ［１０］に記載の液晶材料の二次電池の製造のための使用。
［１８］ ［１０］に記載の液晶材料のキャパシタの製造のための使用。 The present invention includes the following.
[1] A conductive mixed liquid crystal composition containing at least one liquid crystal compound represented by the following general formula (1).

[In the formula,
R represents an alkyl group or an alkoxy group having 5 or more carbon atoms.
B represents a branched alkylene group having 6 or more carbon atoms (the branched alkylene group having 6 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
A represents an organic group containing a conjugated system having 12 or more π electrons and optionally containing a nitrogen atom, an oxygen atom or a sulfur atom.
L represents a linear alkylene group having 3 or more carbon atoms (the linear alkylene group having 3 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
n indicates 2;
The n R, B, A, and L may be the same or different from each other.
X represents Zn2 ⁺ . ]
[2] At least one liquid crystal compound represented by the following general formula (1), wherein n is 1 and X is an ion selected from the group consisting of Li ⁺ , Na ⁺ , and K ⁺ , and the following general A conductive material containing at least one liquid crystal compound represented by the formula (1), wherein n is 2 or 3, and X is an ion selected from the group consisting of Mg ²⁺ , Ca ²⁺ , Ba ²⁺ , Zn ²⁺ and Al ³⁺ mixed liquid crystal composition.

[In the formula,
R represents an alkyl group or an alkoxy group having 5 or more carbon atoms.
B represents a branched alkylene group having 6 or more carbon atoms (the branched alkylene group having 6 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
A represents an organic group containing a conjugated system having 12 or more π electrons and optionally containing a nitrogen atom, an oxygen atom or a sulfur atom.
L represents a linear alkylene group having 3 or more carbon atoms (the linear alkylene group having 3 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
n represents 1, 2, or 3;
When n is 2 or 3, n R, B, A and L may be the same or different from each other.
X represents an ion selected from the group consisting of Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ , Ba ²⁺ , Zn ²⁺ and Al ³⁺ . ]
[3] The conductive mixed liquid crystal composition according to [1] or [2], wherein R in formula (1) is an alkoxy group having 5 or more and 12 or less carbon atoms.
[4] The conductive mixed liquid crystal composition according to any one of [1] to [3], wherein B in the general formula (1) is represented by the following general formula (2).

[In the formula,
R' is an alkyl group having 1 to 6 carbon atoms,
0≦p≦6,
0≤q≤6,
* indicates a bond with A. ]
[5] A in the ionic liquid crystal compound is benzene optionally linked by a single bond, -CH=CH-, -CH≡CH-, -N=N-, -COO-, or -CH=N- ring, thiophene ring, furan ring, pyridine ring, pyrimidine ring, pyrazine ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, naphthalene ring, anthracene ring, quinoline ring, carbazole ring, quinazoline ring, purine ring, indolizine ring , a benzothiophene ring, a benzofuran ring, an indole ring, or an acridine ring, the conductive mixed liquid crystal composition according to any one of [1] to [4].
[6] The conductive mixed liquid crystal composition according to any one of [1] to [5], wherein L in general formula (1) is represented by general formula (3) below.

[In the formula,
m is an integer of 1 or more and 8 or less,
* indicates a bond with A. ]
[7] a liquid crystal compound represented by the general formula (1), wherein X is at least one ion selected from the group consisting of Na ⁺ and K ⁺ ;
A liquid crystal compound represented by the general formula (1), wherein X is at least one ion selected from the group consisting of Mg ²⁺ , Ca ²⁺ , Zn ²⁺ and Ba ²⁺ ; and a liquid crystal compound represented by the general formula (1), any liquid crystal compound in which X is Al ³⁺ ;
a liquid crystal compound represented by the general formula (1), wherein X is Li ⁺ ;
The conductive mixed liquid crystal composition according to any one of [1] to [6], comprising:
[8] sandwiching the conductive mixed liquid crystal composition according to any one of [1] to [7] between a pair of electrodes, and applying a voltage between the pair of electrodes, Ion transport method.
[9] The ion transport method according to [8] for charging a secondary battery.
[10] A liquid crystal material comprising the conductive mixed liquid crystal composition according to any one of [1] to [7].
[11] An ion transport layer containing the liquid crystal material according to [10].
[12] The ion transport layer according to [11], wherein the ion transport method according to [8] is performed.
[13] The liquid crystal material according to [10], which is for a secondary battery.
[14] The liquid crystal material according to [10], which is used as a dielectric of a capacitor.
[15] A secondary battery containing the liquid crystal material according to [10].
[16] A capacitor containing the liquid crystal material according to [10].
[17] Use of the liquid crystal material according to [10] for manufacturing a secondary battery.
[18] Use of the liquid crystal material according to [10] for manufacturing a capacitor.

As a result of intensive studies on the above problems, the present inventors have found that by selecting a bulky group having a branch as the RB- group in the general formula (1), the distance between each liquid crystal molecule is appropriately separated, and the liquid crystal The idea was to lower the onset temperature. In addition, a surprising finding was obtained that the liquid crystal formation initiation temperature is lowered by selecting a specific ion as X. Furthermore, by using ions having appropriately different ionic radii as X together, the inventors have reached the idea of appropriately separating the distances between the liquid crystal molecules and lowering the liquid crystal formation initiation temperature. The ionic radii (poling ionic radii (pm)) are respectively Al ³⁺ (50), Li ⁺ (60), Mg ²⁺ (65), Zn ²⁺ (74), Na ⁺ (95), Ca ²⁺ (99), Since they are K ⁺ (133) and Ba ²⁺ (135), it also came to the idea that it would be effective to utilize them. The present invention exhibits the following remarkable effects by molecular design based on these original ideas.

Since the method of transporting ions according to the present invention uses a conductive mixed liquid crystal composition having a smectic phase as a liquid crystal phase, the liquid crystal state of the smectic phase or the phase transition from the smectic phase during the temperature drop process occurs. The ion transport sites can be densely stacked in a solid state, and ion transport can be efficiently performed by applying a voltage while maintaining this molecular orientation.

Therefore, when a liquid crystal material containing the conductive mixed liquid crystal composition of the present invention is used, ions can be transported more efficiently than before, so that when used as an electrolyte of a secondary battery, the charging time is shortened at room temperature. Shortening is expected. Moreover, when it is used as a dielectric of a capacitor, it is expected that it will be possible to manufacture a high-capacity capacitor because it can be easily formed into a thin film and laminated, and the energy density can be increased.

10 is a polarizing microscope photograph of mixed liquid crystal composition 8 (Example 8). FIG. 10 is a diagram showing ion transport performance at each temperature of mixed liquid crystal composition 8 (Example 8). FIG. 10 is a diagram showing the ion transport performance of liquid crystal compound 12 (Example 13) at each temperature.

［式中、
Ｒは、炭素原子数５以上のアルキル基又はアルコキシ基を示す。
Ｂは、分岐を有する炭素原子数６以上のアルキレン基を示す（前記分岐を有する炭素原子数６以上のアルキレン基は、酸素原子又は硫黄原子を介してＡと結合してもよい）。
Ａは、π電子が１２個以上の共役系を含む、窒素原子、酸素原子又は硫黄原子を含んでもよい有機基を示す。
Ｌは、炭素原子数３以上の直鎖アルキレン基を示す（前記炭素原子数３以上の直鎖アルキレン基は、酸素原子又は硫黄原子を介してＡと結合してもよい）。
ｎは２を示す。
ｎ個のＲ、Ｂ、Ａ、及びＬはそれぞれ同一であってもよく、相互に異なっていてもよい。
Ｘは、Ｚｎ^２＋を示す。］ [Conductive mixed liquid crystal composition]
The present invention relates to a conductive mixed liquid crystal composition containing at least one liquid crystal compound represented by the following general formula (1).

[In the formula,
R represents an alkyl group or an alkoxy group having 5 or more carbon atoms.
B represents a branched alkylene group having 6 or more carbon atoms (the branched alkylene group having 6 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
A represents an organic group containing a conjugated system having 12 or more π electrons and optionally containing a nitrogen atom, an oxygen atom or a sulfur atom.
L represents a linear alkylene group having 3 or more carbon atoms (the linear alkylene group having 3 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
n indicates 2;
The n R, B, A, and L may be the same or different from each other.
X represents Zn2 ⁺ . ]

The present invention also provides at least one liquid crystal compound represented by the following general formula (1), wherein n is 1 and X is an ion selected from the group consisting of Li ⁺ , Na ⁺ , and K ⁺ , and At least one liquid crystal compound represented by the following general formula (1), wherein n is 2 or 3, and X is an ion selected from the group consisting of Mg ²⁺ , Ca ²⁺ , Ba ²⁺ , Zn ²⁺ and Al ³⁺ The present invention relates to a conductive mixed liquid crystal composition comprising:

［式中、
Ｒは、炭素原子数５以上のアルキル基又はアルコキシ基を示す。
Ｂは、分岐を有する炭素原子数６以上のアルキレン基を示す（前記分岐を有する炭素原子数６以上のアルキレン基は、酸素原子又は硫黄原子を介してＡと結合してもよい）。
Ａは、π電子が１２個以上の共役系を含む、窒素原子、酸素原子又は硫黄原子を含んでもよい有機基を示す。
Ｌは、炭素原子数３以上の直鎖アルキレン基を示す（前記炭素原子数３以上の直鎖アルキレン基は、酸素原子又は硫黄原子を介してＡと結合してもよい）。
ｎは１、２、又は３を示す。
ｎが２又は３のとき、ｎ個のＲ、Ｂ、Ａ、及びＬはそれぞれ同一であってもよく、相互に異なっていてもよい。
Ｘは、Ｌｉ^＋、Ｎａ^＋、Ｋ^＋、Ｍｇ^２＋、Ｃａ^２＋、Ｂａ^２＋、Ｚｎ^２＋及びＡｌ^３＋からなる群より選択されるイオンを示す。］

[In the formula,
R represents an alkyl group or an alkoxy group having 5 or more carbon atoms.
B represents a branched alkylene group having 6 or more carbon atoms (the branched alkylene group having 6 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
A represents an organic group containing a conjugated system having 12 or more π electrons and optionally containing a nitrogen atom, an oxygen atom or a sulfur atom.
L represents a linear alkylene group having 3 or more carbon atoms (the linear alkylene group having 3 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
n represents 1, 2, or 3;
When n is 2 or 3, n R, B, A and L may be the same or different from each other.
X represents an ion selected from the group consisting of Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ , Ba ²⁺ , Zn ²⁺ and Al ³⁺ . ]

In order to simplify the description, the term “conductive mixed liquid crystal composition” in the specification of the present application refers to only one type of liquid crystal compound represented by general formula (1), and strictly speaking, it can be said to be a mixed liquid crystal composition. It is used to include the case where there is none.

Preferably,
a liquid crystal compound represented by the general formula (1), wherein X is at least one ion selected from the group consisting of Na ⁺ and K ⁺ ;
A liquid crystal compound represented by the general formula (1), wherein X is at least one ion selected from the group consisting of Mg ²⁺ , Ca ²⁺ , Zn ²⁺ and Ba ²⁺ ; and a liquid crystal compound represented by the general formula (1), any liquid crystal compound in which X is Al ³⁺ ;
a liquid crystal compound represented by the general formula (1), wherein X is Li ⁺ ;
A conductive mixed liquid crystal composition comprising:

In general formula (1), R is an alkyl group or an alkoxy group having 5 or more carbon atoms, preferably an alkoxy group having 5 or more and 12 or less carbon atoms, more preferably 5 or more and 8 or less carbon atoms. It is an alkoxy group, most preferably n-pentoxy, n-hexyoxy, n-heptoxy or n-octoxy.

［式中、
Ｒ’は炭素原子数１以上６以下のアルキル基であり、
０≦ｐ≦６であり、
０≦ｑ≦６であり、
＊はＡとの結合を示す。］ In the general formula (1), B represents a branched alkylene group having 6 or more carbon atoms (the branched alkylene group having 6 or more carbon atoms is bonded to A via an oxygen atom or a sulfur atom. may be used). Preferably, B is a group represented by the following general formula (2).

[In the formula,
R' is an alkyl group having 1 to 6 carbon atoms,
0≦p≦6,
0≤q≤6,
* indicates a bond with A. ]

In general formula (2), R' is preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, or a tert-butyl group, more preferably a methyl group. , or an ethyl group.

In general formula (2), preferably 0≤p≤4, more preferably 0≤p≤2, and most preferably p=2.
In general formula (2), preferably 0≤q≤4, more preferably 0≤q≤2, and most preferably q=2.

In general formula (1), A represents an organic group containing a conjugated system having 12 or more π electrons and optionally containing a nitrogen atom, an oxygen atom or a sulfur atom.
A is preferably a benzene ring or thiophene ring optionally linked by a single bond, -CH=CH-, -CH≡CH-, -N=N-, -COO-, or -CH=N-, furan ring, pyridine ring, pyrimidine ring, pyrazine ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, naphthalene ring, anthracene ring, quinoline ring, carbazole ring, quinazoline ring, purine ring, indolizine ring, benzothiophene ring, represents a benzofuran ring, an indole ring, or an acridine ring;

（式中、ｔは１又は２の整数を示す。）から選ばれる基であり、最も好ましくは、Ａは（１ａ）で表される基である。 More preferably, A represents the following general formulas (1a) to (1d)

(wherein t represents an integer of 1 or 2), and most preferably A is a group represented by (1a).

In the general formula (1), L represents a linear alkylene group having 3 or more carbon atoms (the linear alkylene group having 3 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom. good).

［式中、
ｍは１以上８以下の整数であり、
＊はＡとの結合を示す。］
ｍは、より好ましくは１以上５以下の整数であり、最も好ましくは１以上３以下の整数である。 Preferably, L is a group represented by the following general formula (3).

[In the formula,
m is an integer of 1 or more and 8 or less,
* indicates a bond with A. ]
m is more preferably an integer of 1 or more and 5 or less, and most preferably an integer of 1 or more and 3 or less.

In general formula (1), n represents 1, 2, or 3.
When n is 2 or 3, n R, B, A and L may be the same or different from each other.

（式中、Ｒ、Ｂ、Ａ及びＬは前記と同義である。）で表される有機酸化合物を水溶性有機溶媒に溶解した溶液（Ａ液）に、リチウム、ナトリウム、カリウム、マグネシウム、カルシウム、バリウム、亜鉛又はアルミニウムの水酸化物の水溶液（Ｂ液）を添加して反応を行うことにより、工業的に有利に製造することができる。 [Preparation of conductive mixed liquid crystal composition]
Various liquid crystal compounds represented by the general formula (1) can be synthesized according to synthesis examples described later.
For example, the following general formula (3)

(Wherein, R, B, A and L are as defined above.) Lithium, sodium, potassium, magnesium and calcium are added to a solution (liquid A) of an organic acid compound represented by the formula dissolved in a water-soluble organic solvent. , barium, zinc or aluminum hydroxide (liquid B) is added for reaction, industrially advantageous production is possible.

The water-soluble organic solvent for dissolving the organic acid compound represented by the general formula (3) varies depending on the type of the organic acid compound used, but in many cases dioxane, tetrahydrofuran, 1,2-diethoxyethane, and diethylene glycol. One or more of dimethyl ether, acetone, methyl ethyl ketone, methyl isobutyl ketone, trioxane, tetrahydropyran, 1,2-dimethoxyethane, diethylene glycol diethyl ether and the like can be used.

The concentration of the organic acid compound represented by the general formula (3) in liquid A is not particularly limited as long as it is within a concentration range in which the organic acid compound can be dissolved. Depending on the type of solvent, it is usually 0.001 to 1 mol/L, preferably 0.05 to 0.5 mol/L.

The aqueous solution of hydroxides of lithium, sodium, potassium, magnesium, calcium, barium, zinc or aluminum can be an aqueous solution in which one or more of these hydroxides are dissolved in water. The concentration of these hydroxides in the aqueous solution is not particularly limited as long as it is within the concentration range in which these hydroxides can be dissolved. 5 mol/L, more preferably 0.2 to 0.4 mol/L.

By dissolving a plurality of these hydroxides in water in an arbitrary ratio to form an aqueous solution and reacting this with an organic acid compound, a mixture of a plurality of liquid crystal compounds having different cation species (mixed liquid crystal composition) can be easily produced. can be prepared to

The addition rate of the aqueous hydroxide solution is not particularly limited, but it is preferable to adjust the addition rate appropriately so that the reaction temperature is in the range of 0 to 80°C, preferably 5 to 30°C.

After adding a predetermined amount of the hydroxide aqueous solution, after performing an aging reaction if necessary, the solvent is removed by a conventional method, and if necessary, purification such as washing is performed, and the desired general formula (1) is obtained. A liquid crystal compound can be obtained. When an aqueous solution obtained by dissolving a plurality of kinds of hydroxides in an arbitrary ratio in water is reacted with an organic acid compound, a mixed liquid crystal composition can be obtained immediately.

[Applications of the conductive mixed liquid crystal composition]
Since the conductive mixed liquid crystal composition according to the present invention is a mixture of liquid crystal compounds having specific R, B, A, L and X, the temperature range exhibiting liquid crystallinity is expanded and the liquid crystal formation temperature is lowered. can be made

The present invention also relates to a method for transporting ions, in which a conductive mixed liquid crystal composition is used and ions are transported by applying a voltage in a liquid crystal state at room temperature. More specifically, the method for transporting ions according to the present invention includes sandwiching the above-described conductive mixed liquid crystal composition between a pair of electrodes in a liquid crystal state at room temperature, and applying a voltage between the pair of electrodes. including applying.

Preferably, the ion transport method is an ion transport method for charging a secondary battery at room temperature.
According to the present invention, specific groups are selected as R, B, A, and L in general formula (1), and specific ions are selected as X, or ions having moderately different ionic radii are used in combination. Therefore, a liquid crystal formation start temperature lower than that in the conventional art can be realized. At the same time, by overlapping the mesogenic moieties in the ionic liquid crystal compound, A, which is the functional group responsible for transporting ions, occupies spatially regular positions, so that a high ion transport rate can be achieved. As a result, the secondary battery to which the conductive mixed liquid crystal composition according to the present invention is applied has the advantageous effect of enabling rapid charging at room temperature.

The present invention also relates to a liquid crystal material comprising a conductive mixed liquid crystal composition. The conductive mixed liquid crystal composition according to the present invention is a liquid crystal material that exhibits conductivity at room temperature and is expected to be applied as an ion transport material and as an electrolyte for secondary batteries.

Other components that can be included in the liquid crystal material according to the present invention are added to the conductive mixed liquid crystal composition according to the present invention in an amount within a range that does not impair the effects of the present invention for the purpose of widening the liquid crystal temperature range. A liquid crystal compound other than the liquid crystal compound contained can be used in combination.

The liquid crystal compound other than the liquid crystal compound contained in the conductive mixed liquid crystal composition according to the present invention is not particularly limited, and examples thereof include liquid crystal compounds disclosed in JP-A-2017-105874. .

The liquid crystal material according to the present invention can further contain other electrolytes, organic solvents, and the like.

Since the liquid crystal material according to the present invention has a smectic phase as a liquid crystal phase, the ion transport sites are densely packed in the liquid crystal state of the smectic phase or in the solid state caused by the phase transition in the process of cooling from the smectic phase. Efficient ion transport can be expected by stacking and using it as an electrolyte for a secondary battery while maintaining this molecular orientation.

In addition, the liquid crystal material according to the present invention can efficiently transport ions by adjusting the concentration of the ionic liquid crystal compound in the solvent to form a lyotropic liquid crystal state and using it as the electrolyte of a secondary battery in this lyotropic liquid crystal state. can be expected to do so.

This is because the mixture of the ionic liquid crystal compounds according to the present invention is controlled in the lyotropic liquid crystal state by controlling the orientation of the molecular chains to the lamellar phase orientation. Therefore, the ionic liquid crystal compound is regularly oriented uniaxially, and by applying a voltage in this liquid crystal state, ions can be transported very efficiently.

As the solvent used in the lyotropic liquid crystal state, electrolyte solutions used in the field of secondary batteries can be used. low-viscosity solvents such as 1,2-dimethoxyethane, 2-methyltetrahydrofuran, dimethyl carbonate, methylethyl carbonate, and diethyl carbonate; and mixed solvents thereof.

Therefore, since the liquid crystal material according to the present invention can efficiently transport ions, it can be expected to shorten the charging time at room temperature when used as an electrolyte for a secondary battery.

The form of the liquid crystal material according to the present invention is not particularly limited. For example, when it is used as an electrolyte for a secondary battery, it may be interposed as a lithium ion transport layer between the positive electrode and the negative electrode.

When the liquid crystal material according to the present invention is used as an electrolyte for a secondary battery in a solid state that occurs due to a phase transition from the smectic phase during a temperature drop process, the liquid crystal material is applied to the interface in the solid state, Ions can move smoothly at solid interfaces.

Such an ion transport layer can transport ions by the mechanism described above, and is extremely useful as an electrolyte for secondary batteries and a dielectric for capacitors.

The use of the liquid crystal material according to the present invention for manufacturing secondary batteries and capacitors, the secondary battery containing the liquid crystal material according to the present invention as an electrolyte, and the capacitor containing the liquid crystal material according to the present invention as a dielectric are also present. It is included in the scope of the invention.

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to these examples.

<Synthesis Example 1 Synthesis of Compound 2>

11.2 g (0.060 mol) of 4,4'-biphenol was dissolved in 50 ml of DMF in a 500 ml Erlenmeyer flask. 8.3 g (0.060 mol) of potassium carbonate was added thereto, and the mixture was stirred at room temperature (25° C.) for 24 hours under a nitrogen atmosphere. After stirring, 16.8 g (0.06 mol) of alkyl bromide 1 (alkyl=nC ₇ H ₁₅ —) was slowly added, and the mixture was stirred at 80° C. under a nitrogen atmosphere for 24 hours.
After completion of the reaction, the reaction solution was cooled and 300 ml of diethyl ether was added. After that, 300 ml of 10% hydrochloric acid was added for extraction and washed with 100 ml of distilled water. The aqueous layer was re-extracted with diethyl ether and washed. Anhydrous sodium sulfate was added and dried overnight.
Anhydrous sodium sulfate was removed by suction filtration, and diethyl ether was removed under reduced pressure.
60 ml of n-hexane was added, ultrasonic cleaning was performed for 50 minutes, cooling was performed in a freezer for one day, and an insoluble portion was obtained by filtration.
100 ml of these toluenes were added, ultrasonic cleaning was performed, and a dissolved portion was obtained by filtration. Toluene was removed under reduced pressure to obtain target compound 2 .
Yield: 3.7g
Theoretical yield: 23.1 g
Yield: 16%
Form: White solid Molecular weight: 384.6
NMR data and IR data of target compound 2 are shown in the table below.

<Synthesis Example 2 Synthesis of Compound 4>

3.7 g (0.0095 mol) of Compound 2 obtained in Synthesis Example 1 and 5.8 g (0.038 mol) of 1,8-diazabicyclo[5,4,0]-7-undecene (DBU) were placed in a 100 ml Erlenmeyer flask. ) and 8.5 g (0.038 mol) of sodium 3-bromopropanesulfonate were added, dissolved in 60 ml of DMF, and stirred at 60° C. for 48 hours under a nitrogen atmosphere.
After completion of the reaction, the solvent was removed by an evaporator, 100 ml of diethyl ether was added, ultrasonic cleaning was performed, and an insoluble portion was obtained by filtration. This operation was performed twice. 10 ml of distilled water and 10 ml of hydrochloric acid were added to the resulting insoluble portion, left to stand for one day, and an insoluble portion was obtained by filtration. 100 ml of THF was added to the obtained insoluble portion and stirred for 30 minutes. After stirring, a filtrate was obtained by filtration.
The solvent was removed under reduced pressure by an evaporator to obtain a solid.
The resulting solid was dissolved in 200 ml of dioxane and filtered to obtain a filtrate.
The solvent was removed under reduced pressure by an evaporator to obtain the target compound 4 .
Yield: 3.4g
Theoretical yield: 4.8g
Yield: 71%
Form: black gray solid (slightly viscous)
Molecular weight: 506.7
NMR data and IR data of target compound 4 are shown in the table below.

<Synthesis Example 3 Synthesis of Mixed Liquid Crystal Composition 5>

0.1916 g (0.0004 mol) of compound 4 was added to a 100 ml Erlenmeyer flask and dissolved in 50 ml of dioxane.
To this, 0.0038 g (0.00009 mol) of lithium hydroxide monohydrate, 0.0034 g (0.000085 mol) of sodium hydroxide, 0.0062 g (0.00011 mol) of potassium hydroxide, aluminum hydroxide An aqueous solution of 0.004 g (0.00051 mol) dissolved in 10 ml of distilled water was added and stirred for 24 hours.
After stirring, the mixture was transferred to a 500 ml Erlenmeyer flask, and the solvent was removed under reduced pressure using an evaporator.
100 ml of diethyl ether was added and washed by shaking well. Filtration was performed to obtain a precipitate. This operation was repeated twice to obtain the desired mixed liquid crystal composition 5 . This composition was evaluated as Example 7.
Yield: 0.130 g
Theoretical yield: 0.2g
Yield: 63%
Form: White powder Solid molecular weight: 529.7

Synthesis Example 4 Synthesis of Mixed Liquid Crystal Composition 7

0.305 g of Compound 6 obtained according to Synthesis Example 2 was added to a 100 ml Erlenmeyer flask and dissolved in 50 ml of dioxane.
0.0082 g (0.000192 mol) of lithium hydroxide monohydrate, 0.0078 g (0.000196 mol) of sodium hydroxide, and 0.000196 mol of aluminum hydroxide are added in a 100 ml beaker while stirring with a stirrer. An aqueous solution of 0.0052 g (0.0000663 mol) dissolved in 10 ml of distilled water was added little by little and stirred for about 3 hours.
The solvent was then removed under reduced pressure and 20 ml of diethyl ether was added. After scraping off deposits on the inner wall of the flask using a spatula, the flask was lightly shaken with the lid closed. After that, suction filtration was performed to obtain the intended mixed liquid crystal composition 7 . This composition was evaluated as Example 9.
Yield: 0.326 g
Theoretical yield: 0.190 g
Yield: 58.3%
Shape: brown powder

<Synthesis Example 5 Synthesis of Mixed Liquid Crystal Composition 8>

0.302 g of Compound 6 obtained according to Synthesis Example 2 was added to a 100 ml Erlenmeyer flask and dissolved in 50 ml of dioxane.
Dissolve 0.0122 g (0.000291 mol) of lithium hydroxide monohydrate, 0.00750 g (0.0000962 mol) of aluminum hydroxide, and 10 ml of distilled water in a 100 ml beaker while stirring with a stirrer. The resulting aqueous solution was added portionwise and stirred for about 3 hours.
The solvent was then removed under reduced pressure and 20 ml of diethyl ether was added. After scraping off deposits on the inner wall of the flask using a spatula, the flask was lightly shaken with the lid closed. After that, suction filtration was performed to obtain the intended mixed liquid crystal composition 8 . This composition was evaluated as Example 8.
Yield: 0.315g
Theoretical yield: 0.076g
Yield: 24.1%
Shape: brown powder

<Synthesis Example 6 Synthesis of Liquid Crystal Compound 12>

0.247 g (0.0005 mol) of compound 11 was added to a 100 ml Erlenmeyer flask and dissolved in 50 ml of dioxane.
An aqueous solution prepared by dissolving 0.025 g (0.00025 mol) of zinc hydroxide in 10 ml of distilled water was added thereto and stirred for 24 hours.
After stirring, the solvent was removed under reduced pressure by an evaporator to obtain the target liquid crystal compound 12 . This compound was evaluated as Example 13.
Yield: 0.212 g
Theoretical yield: 0.247 g
Yield: 85.8%
Form: Yellow solid Molecular weight: 492.5

０．０００２ｍｏｌの化合物１３と０．０００２ｍｏｌの化合物１４とを５０ｍｌのジオキサンに溶解させ、溶液Ａとした。０．０００２ｍｏｌの水酸化亜鉛を１０ｍｌの蒸留水に溶解させ、溶液Ｂとした。溶液Ｂを溶液Ａに加え、２４時間撹拌した。
撹拌後、エバポレーターによって溶媒を完全に減圧除去し、目的とする液晶組成物１５＋１６を得た。本組成物は実施例１５として評価した。
収量：０．１０ｇ
収率：４４％ <Synthesis Example 7 Synthesis of Liquid Crystal Compositions 15+16>

A solution A was obtained by dissolving 0.0002 mol of compound 13 and 0.0002 mol of compound 14 in 50 ml of dioxane. A solution B was obtained by dissolving 0.0002 mol of zinc hydroxide in 10 ml of distilled water. Solution B was added to solution A and stirred for 24 hours.
After stirring, the solvent was completely removed under reduced pressure by an evaporator to obtain the target liquid crystal composition 15 + 16 . This composition was evaluated as Example 15.
Yield: 0.10 g
Yield: 44%

<Evaluation of ion transport>
Various mixed liquid crystal compositions shown in Table 1 below were prepared according to the above synthesis examples, and their ion transport performance was evaluated.
20 mg of a sample was pressed into a cell provided with ITO electrodes (electrode area: 0.16 cm ² , distance between electrodes: 70 μm, gap: 50 μm, manufactured by EHC).
Next, a voltage of 10 V was applied, the temperature was gradually increased, and the current value was measured at each temperature. Current values at room temperature (30° C.) are also shown in Table 1 below.

A polarizing microscope photograph of mixed liquid crystal composition 8 (Example 8) is shown in FIG. It can be seen that liquid crystal is formed not only at 120° C. but also at room temperature (30° C.).
FIG. 2 shows the ion transport performance of the mixed liquid crystal composition 8 (Example 8) at each temperature. Compared to conventional liquid crystal compounds, the peak of ion transport performance shifts to the low temperature side, and as a result, conductivity at room temperature is realized.

FIG. 3 shows the ion transport performance of the liquid crystal compound 12 (Example 13) at each temperature. Compared to conventional liquid crystal compounds, the peak of ion transport performance shifts to the low temperature side, and as a result, conductivity at room temperature is realized.

Therefore, when the liquid crystal material containing the ionic liquid crystal compound of the present invention or a mixture thereof is used, ions can be efficiently transported even at a lower temperature than before. Shortening of charging time can be expected. Moreover, when it is used as a dielectric of a capacitor, it can be easily formed into a thin film and laminated, and the energy density can be increased, so that a high capacity capacitor can be manufactured.

Claims (18)

A conductive mixed liquid crystal composition containing at least one liquid crystal compound represented by the following general formula (1).

[In the formula,
R represents an alkyl group or an alkoxy group having 5 or more carbon atoms.
B represents a branched alkylene group having 6 or more carbon atoms (the branched alkylene group having 6 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
A represents an organic group containing a conjugated system having 12 or more π electrons and optionally containing a nitrogen atom, an oxygen atom or a sulfur atom.
L represents a linear alkylene group having 3 or more carbon atoms (the linear alkylene group having 3 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
n indicates 2;
The n R, B, A, and L may be the same or different from each other.
X represents Zn2 ⁺ . ] At least one liquid crystal compound represented by the following general formula (1), wherein n is 1 and X is an ion selected from the group consisting of Li ⁺ , Na ⁺ , and K ⁺ , and the following general formula (1 ), n is 2 or 3, and X is an ion selected from the group consisting of Mg ²⁺ , Ca ²⁺ , Ba ²⁺ , Zn ²⁺ and Al ³⁺ . Composition.

[In the formula,
R represents an alkyl group or an alkoxy group having 5 or more carbon atoms.
B represents a branched alkylene group having 6 or more carbon atoms (the branched alkylene group having 6 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
A represents an organic group containing a conjugated system having 12 or more π electrons and optionally containing a nitrogen atom, an oxygen atom or a sulfur atom.
L represents a linear alkylene group having 3 or more carbon atoms (the linear alkylene group having 3 or more carbon atoms may be bonded to A via an oxygen atom or a sulfur atom).
n represents 1, 2, or 3;
When n is 2 or 3, n R, B, A and L may be the same or different from each other.
X represents an ion selected from the group consisting of Li ⁺ , Na ⁺ , K ⁺ , Mg ²⁺ , Ca ²⁺ , Ba ²⁺ , Zn ²⁺ and Al ³⁺ . ] 3. The conductive mixed liquid crystal composition according to claim 1, wherein R in general formula (1) is an alkoxy group having 5 to 12 carbon atoms. 4. The conductive mixed liquid crystal composition according to claim 1, wherein B in general formula (1) is represented by general formula (2) below.

[In the formula,
R' is an alkyl group having 1 to 6 carbon atoms,
0≦p≦6,
0≤q≤6,
* indicates a bond with A. ] A of the ionic liquid crystal compound is a single bond, -CH=CH-, -CH≡CH-, -N=N-, -COO-, or -CH=N-, a benzene ring optionally linked by a thiophene ring, furan ring, pyridine ring, pyrimidine ring, pyrazine ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, naphthalene ring, anthracene ring, quinoline ring, carbazole ring, quinazoline ring, purine ring, indolizine ring, benzothiophene 5. The conductive mixed liquid crystal composition according to any one of claims 1 to 4, representing a ring, a benzofuran ring, an indole ring, or an acridine ring. 6. The conductive mixed liquid crystal composition according to claim 1, wherein L in general formula (1) is represented by general formula (3) below.

[In the formula,
m is an integer of 1 or more and 8 or less,
* indicates a bond with A. ] a liquid crystal compound represented by the general formula (1), wherein X is at least one ion selected from the group consisting of Na ⁺ and K ⁺ ;
A liquid crystal compound represented by the general formula (1), wherein X is at least one ion selected from the group consisting of Mg ²⁺ , Ca ²⁺ , Zn ²⁺ and Ba ²⁺ ; and a liquid crystal compound represented by the general formula (1), any liquid crystal compound in which X is Al ³⁺ ;
a liquid crystal compound represented by the general formula (1), wherein X is Li ⁺ ;
The conductive mixed liquid crystal composition according to any one of claims 1 to 6, comprising A method for transporting ions, comprising sandwiching the conductive mixed liquid crystal composition according to claim 1 between a pair of electrodes, and applying a voltage between the pair of electrodes. 9. A method for transporting ions according to claim 8 for charging a secondary battery. A liquid crystal material comprising the conductive mixed liquid crystal composition according to claim 1 . An ion transport layer comprising the liquid crystal material according to claim 10 . 12. The ion transport layer according to claim 11, wherein the ion transport method according to claim 8 is performed. 11. The liquid crystal material according to claim 10, which is for a secondary battery. 11. The liquid crystal material according to claim 10, for use as a capacitor dielectric. A secondary battery comprising the liquid crystal material according to claim 10 . A capacitor comprising the liquid crystal material according to claim 10 . Use of the liquid crystal material according to claim 10 for manufacturing secondary batteries. Use of the liquid crystal material according to claim 10 for manufacturing capacitors.

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