TW201602069A - Zwitterionic compound and ion conductor - Google Patents

Abstract

The present invention is a zwitterionic compound represented by formula (I): R1 - A+ - X - SO3 -, and an ion conductor containing the zwitterionic compound. In formula (I), R1 represents a C2-20 group that has an ether bond and bonds with the nitrogen atom the A+ moiety (with the caveat that the atom that bonds with the nitrogen atom of A+ is a carbon atom), A+ represents a specific cationic group having a nitrogen atom, and X represents a C2-5 alkylene group that bonds with the nitrogen atom of A+. The present invention provides: a new zwitterionic compound having ion conductivity, good solubility in organic solvents, and a low glass transition temperature and melting point; and an ion conductor containing the zwitterionic compound.

Description

Zwitterionic compounds and ion conductors

The present invention relates to a novel zwitterionic compound having ion conductivity and excellent solubility in an organic solvent, and having a low glass transition temperature and a low melting point, and an ion conductor containing the zwitterionic compound.

In recent years, a zwitterionic compound having a cationic site and an anionic site in the same molecule has been attracting attention as a material of an ion conductor, various additives, and the like.

For example, Patent Documents 1 and 2 describe a proton conductor composed of a zwitterionic salt and a proton donor, and a fuel cell having a proton conducting layer composed of the proton conductor.

Patent Document 3 describes a zwitterionic compound which is used as an antistatic agent or the like.

Prior technical literature

Patent literature

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2005-228588 (US2006/0263661 A1)

[Patent Document 2] WO2006/025482 pamphlet (US2007/0231647 A1)

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2005-272316

As described above, the zwitterionic compound is useful as a material of an ion conductive member of an electrochemical device such as a fuel cell or a lithium battery.

However, the conventional zwitterionic compound is inferior in workability when producing an ion conductive member or the like because of poor solubility in a usual organic solvent, high glass transition temperature, melting point, and the like.

The present invention has been made in view of such circumstances, and an object thereof is to provide a novel zwitterionic compound which is excellent in solubility in an organic solvent and which has a low glass transition temperature and a low melting point, and an ion conductor containing the zwitterionic compound.

In order to solve the problem, the inventors of the present invention have found that a zwitterionic compound having a cationic group and a sulfonic acid group and having a group containing an ether bond has ion conductivity and is excellent in solubility in an organic solvent. Moreover, the glass transition temperature and the melting point are low to complete the present invention.

As described above, according to the present invention, the zwitterionic compounds of the following (1) to (3) and the ion conductors of (4) and (5) can be provided.

(1) A zwitterionic compound represented by the following formula (I), [Chem. 1] R ¹ -A ⁺ -X-SO ₃ ^- (I)

[Wherein, R ¹ is line represents a group having a carbon number ether bond of bonding of the A ⁺ nitrogen atom of 2 to 20 (however, with A ⁺ atom based carbon atoms atoms bonded to the nitrogen), A ⁺ are diagrams a cationic group represented by the following formula (II) or formula (III), and X represents an alkylene group having 2 to 5 carbon atoms bonded to a nitrogen atom of A ⁺ ],

[wherein R ² is a group having 2 to 20 carbon atoms of an ether bond (however, an atomic carbon atom bonded to a nitrogen atom), an R ³ -based hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and an ether; a bond having 2 to 20 carbon atoms (however, an atomic carbon atom bonded to a nitrogen atom), or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, * means a dangling bond],

(wherein Y represents -C(R ¹² )(R ¹³ )-, -N(R ¹⁴ )-, -O-, or -S-, and R ⁴ to R ¹⁴ each independently represent a hydrogen atom or a carbon. A number of 1 to 10 alkyl groups, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, * means a dangling bond).

(2) The zwitterionic compound according to (1), wherein the number of ether bonds in the group having 2 to 20 carbon atoms of the ether bond of R ¹ , R ² and R ³ is independently from 1 to 5.

(3) The zwitterionic compound according to (1), wherein the groups of the carbon groups 2 to 20 having an ether bond of R ¹ , R ² and R ³ are each independently of the following formula (IV) to formula (IV). The group represented by any of VII), R ⁵ -OZ ¹ -* (IV) R ¹⁶ -OZ ² -OZ ³ -* (V) R ¹⁷ -OZ ⁴ -OZ ⁵ -OZ ⁶ - * (VI) R ¹⁸ -OZ ⁷ -OZ ⁸ -OZ ⁹ -OZ ¹⁰ -* (VII)

(wherein R ¹⁵ represents an alkyl group having 1 to 19 carbon atoms, Z ¹ represents an alkylene group having 1 to 19 carbon atoms, and the total number of carbon atoms of R ¹⁵ and Z ¹ is 2 to 20, and R ¹⁶ represents An alkyl group having 1 to 17 carbon atoms, a Z ² group representing an alkylene group having 2 to 18 carbon atoms, a Z ³ group representing an alkylene group having 1 to 17 carbon atoms, and a total of carbon numbers of R ¹⁶ , Z ² and Z ³ . 4 to 20, R ¹⁷ represents an alkyl group having 1 to 15 carbon atoms, Z ⁴ and Z ⁵ each independently represent an alkylene group having 2 to 16 carbon atoms, and Z ⁶ represents an alkylene group having 1 to 15 carbon atoms. The total number of carbon atoms of R ¹⁷ , Z ⁴ , Z ⁵ and Z ⁶ is 6 to 20, R ¹⁸ represents an alkyl group having 1 to 13 carbon atoms, and Z ⁷ , Z ⁸ and Z ⁹ each independently represent carbon. a number of 2 to 14 alkylene groups, Z ¹⁰ series represents an alkylene group having 1 to 13 carbon atoms, and a total of 8 to 20 carbon atoms of R ¹⁸ , Z ⁷ , Z ⁸ , Z ⁹ and Z ¹⁰ are represented by * Dangling button).

(4) An ion conductor comprising the amphoteric compound described in the above (1) and a salt of a metal of Group 1 or Group 2 of the periodic table.

(5) The ion conductor according to (4), wherein the metal salt is a lithium salt.

According to the present invention, it is possible to provide a novel zwitterionic compound having ion conductivity and excellent solubility in an organic solvent, and having a low glass transition temperature and a low melting point, and an ion conductor containing the zwitterionic compound.

Hereinafter, the present invention will be described in detail by substituting 1) a zwitterionic compound and 2) an ion conductor.

In the present invention, the "zionic ion compound having ion conductivity" means a zwitterionic compound capable of obtaining a mixture having ion conductivity when mixed with an ionic compound containing ions to be transported. Further, the "ion-conducting mixture" is referred to as an ion conductor, and for example, an ion conductor having a lithium ion transporting ability is referred to as a lithium ion conductor.

1) Zwitterionic compounds

The zwitterionic compound of the present invention is a compound represented by the above formula (I). Of formula (I), R ¹ is represented by the Department of A ⁺ having a nitrogen atom bonded to the group (However, A ⁺ with the nitrogen atom bonded to the carbon atom-based) carbon atoms, an ether bond of 2 to 20.

The carbon group having an ether bond of R ¹ has a carbon number of 2 to 20, preferably 2 to 10, more preferably 2 to 5.

In the group having 2 to 20 carbon atoms having an ether bond of R ¹ , the number of ether bonds is not particularly limited, and is preferably 1 to 5, more preferably 1 to 3.

Examples of the group having 2 to 20 carbon atoms having an ether bond of R ¹ include ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl and t-butyl groups. A structure in which one or two or more carbon-carbon bonds of an alkyl group are inserted into one oxygen atom. (for example, the base represented by the above formula (IV) to formula (VII)).

Specific examples of the group having 2 to 20 carbon atoms having an ether bond of R ¹ include the groups represented by the above formulas (IV) to (VII).

In the formula (IV), R ¹⁵ represents an alkyl group having 1 to 19 carbon atoms, Z ¹ represents an alkylene group having 1 to 19 carbon atoms, and the total number of carbon atoms of R ¹⁵ and Z ¹ is 2 to 20.

In the formula (V), R ¹⁶ represents an alkyl group having 1 to 17 carbon atoms, Z ² represents an alkylene group having 2 to 18 carbon atoms, and Z ³ represents an alkylene group having 1 to 17 carbon atoms, and R ¹⁶ , The total carbon number of Z ² and Z ³ is 4-20.

In the formula (VI), R ¹⁷ represents an alkyl group having 1 to 15 carbon atoms, Z ⁴ and Z ⁵ each represents an alkylene group having 2 to 16 carbon atoms independently, and Z ⁶ represents a stretching having 1 to 15 carbon atoms. The total number of carbon atoms of the alkyl group, R ¹⁷ , Z ⁴ , Z ⁵ and Z ⁶ is 6-20.

In the formula (VII), R ¹⁸ represents an alkyl group having 1 to 13 carbon atoms, and Z ⁷ , Z ⁸ and Z ⁹ each independently represent an alkylene group having 2 to 14 carbon atoms, and Z ¹⁰ represents a carbon number of 1 to 3; The alkyl group of 13 is a total of 8 to 20 carbon atoms of R ¹⁸ , Z ⁷ , Z ⁸ , Z ⁹ and Z ¹⁰ .

^Examples of the alkyl group of R ¹⁵ to R ¹⁸ include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a second butyl group, and a third butyl group.

Among these, since the zwitterionic compound has a high solubility in an organic solvent, the alkyl group of R ¹⁵ to R ¹⁸ is preferably a group having a carbon number of 1 to 4, preferably a methyl group or an ethyl group. .

Examples of the alkylene group of Z ¹ to Z ¹⁰ include a linear alkyl group such as a methylene group, an ethylidene group, a trimethylene group, a tetramethylene group or a pentamethylene group; propane-1,2- A branched chain alkyl group of a diyl group, a butane-1,3-diyl group or the like.

Among these, since the solubility of the zwitterionic compound in the organic solvent is high, the alkylene group of Z ¹ , Z ³ , Z ⁶ and Z ¹⁰ is preferably a group having a carbon number of 1 to 4, and the carbon number is The base of 1 to 3 is preferred, and a methylene group or an ethylidene group is more preferred. Further, the alkylene group of Z ² , Z ⁴ , Z ⁵ , Z ⁷ , Z ⁸ and Z ⁹ is preferably a group having 2 to 4 carbon atoms, and preferably a group having 2 to 3 carbon atoms. Ethyl is preferred.

Among these, the group having 2 to 20 carbon atoms having an ether bond as R ¹ is an ethoxymethyl group, a 2-methoxyethyl group, and a 2-(2-methoxyethoxy) group B. The base is good.

In the formula (I), the A ⁺ group represents a cationic group represented by the above formula (II) or formula (III).

In the above formula (II), R ² represents a group having 2 to 20 carbon atoms having an ether bond (however, an atomic carbon atom bonded to a nitrogen atom).

The carbon group having an ether bond of R ² has a carbon number of 2 to 20, preferably 2 to 10, more preferably 2 to 5.

The number of ether bonds in the group having 2 to 20 carbon atoms of the ether bond of R ² is not particularly limited, and is preferably 1 to 5, more preferably 1 to 3.

The group having 2 to 20 carbon atoms having an ether bond as R ² may be the same as those shown as a group having 2 to 20 carbon atoms which have an ether bond as R ¹ . Among these, ethoxymethyl group, 2-methoxyethyl group, and 2-(2-methoxyethoxy)ethyl group are preferred.

R ³ represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a group having 2 to 20 carbon atoms having an ether bond (however, an atomic carbon atom bonded to a nitrogen atom), or a substituted or unsubstituted carbon. Number 6 to 20 aryl groups.

The alkyl group of R ³ has a carbon number of 1 to 20, preferably 2 to 15, more preferably 3 to 10.

The alkyl group having 1 to 20 carbon atoms of R ³ may be the same as those shown for the alkyl group as R ¹⁵ to R ¹⁸ . Among these, n-butyl group is particularly preferred.

The carbon group having an ether bond of R ³ has a carbon number of 2 to 20, preferably 2 to 10, more preferably 2 to 5.

The number of ether bonds in the group having 2 to 20 carbon atoms of the ether bond of R ³ is not particularly limited, and is preferably 1 to 5, more preferably 1 to 3.

The group having 2 to 20 carbon atoms having an ether bond as R ³ may be the same as those shown as a group having 2 to 20 carbon atoms having an ether bond as R ¹ . Among these, ethoxymethyl group, 2-methoxyethyl group, and 2-(2-methoxyethoxy)ethyl group are preferred.

The substituted or unsubstituted aryl group of R ^{3 has} a carbon number of 6 to 20, preferably 6 to 10.

Examples of the unsubstituted aryl group of R ³ include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group.

Examples of the substituent of the substituted aryl group of R ³ include an alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group; an alkoxy group having 1 to 6 carbon atoms such as a methoxy group or an ethoxy group.

Among these, since the zwitterionic compound has high solubility in an organic solvent, R ³ is preferably a group having 2 to 20 carbon atoms having an ether bond.

In the above formula (III), R ⁴ to R ¹¹ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

The alkyl group of R ⁴ to R ¹¹ has a carbon number of 1 to 10, preferably 1 to 8, more preferably 1 to 5.

Examples of the alkyl group having 1 to 10 carbon atoms of R ⁴ to R ¹¹ include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a second butyl group, and a third butyl group. Wait.

The substituted or unsubstituted aryl group of R ⁴ to R ^{11 has} a carbon number of 6 to 20, preferably 6 to 10.

As R ⁴ ~ R ¹¹ is a substituted or unsubstituted aryl group, and as R include substituted or unsubstituted ³ carbon atoms, an aryl group of 6 to 20 was displayed by the same.

Y represents -C(R ¹² )(R ¹³ )-, -N(R ¹⁴ )-, -O-, or -S-. R ¹² to R ¹⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

The alkyl group of R ¹² to R ¹⁴ has a carbon number of from 1 to 10, preferably from 1 to 8, more preferably from 1 to 5.

The substituted or unsubstituted aryl group of R ¹² to R ^{14 has} a carbon number of 6 to 20, preferably 6 to 10.

The alkyl group having 1 to 10 carbon atoms and the substituted or unsubstituted aryl group having 6 to 20 carbon atoms of R ¹² to R ¹⁴ may be the same as those of R ⁴ to R ¹¹ .

Among these, since the solubility of the zwitterionic compound in the organic solvent is high, the Y system is preferably (-O-).

In the formula (I), X represents an alkylene group having 2 to 5 carbon atoms bonded to the nitrogen atom of A ⁺ .

Examples of the alkylene group having 2 to 5 carbon atoms of X include a linear alkyl group such as an ethyl group, a trimethylene group, a tetramethylene group or a pentamethylene group; and a propane-1,2-diyl group; a branched chain alkyl group of butane-1,3-diyl or the like.

Since the zwitterionic compound of the present invention has an ether bond in R ¹ and A ⁺ , it is excellent in solubility in an organic solvent, and has a low glass transition temperature and a low melting point.

The number of ether bonds in the zwitterionic compound is 1 or more, preferably 2 or more, and more preferably 3 or more. There is no particular upper limit on the number of ether bonds, and it is usually 15 or less.

The method for producing the zwitterionic compound of the present invention is not particularly limited. For example, A ⁺ is a zwitterionic compound (Ia) represented by the formula (II), which can be represented by the following formula, by allowing the corresponding ether bond-containing amine compound (IVa) and sultone compound (V) )reaction.

(In the above formula, R ¹ , R ² and R ^{3 have the} same meanings as described above, and n is 0, 1, 2 or 3).

The ether compound-containing amine compound (IVa) used in the above reaction may, for example, be bis(2-methoxyethyl)amine, gin(2-methoxyethyl)amine or N,N-bis ( 2-methoxyethyl)-N-butylamine, ginseng [2-(2-methoxyethoxy)ethyl]amine, etc., but are not limited by these compounds.

Further, A ⁺ is a zwitterionic compound (Ib) represented by the formula (III), which can be represented by the following formula, by allowing the corresponding ether bond-containing amine compound (IVb) and sultone compound (V) )reaction.

(In the above formula, R ¹ , R ⁴ to R ¹¹ , Y and n are the same meanings as described above).

The ether compound-containing amine compound (IVb) used in the above reaction may, for example, be 1-(2-methoxyethyl)piperidine or 1-(2-methoxyethyl)piperazine or 1- (2-methoxyethyl)-4-methylpiperazine, N-(2-methoxyethyl)morpholine, N-(2-methoxyethyl)thiomorpholine, etc., but not It is defined by these compounds.

These ether bond-containing amine compounds can be obtained by production in the synthesis method described in the examples. Further, as the amine compound containing an ether bond, a commercially available product can also be used.

The sulfonate compound used in the above reaction may, for example, be 1,2-ethane sultone, 1,3-propane sultone, 1,4-butane sultone or 2,4-butane sulfonate. Lactone, 1,5-pentane sultone, but not limited by these compounds.

These conventional compounds can be obtained by a conventional method. Further, as the sultone compound, a commercially available product can also be used.

In the reaction of the ether bond-containing amine compound with the sultone compound, the sultone compound is preferably used in an amount of from 0.8 to 1.2 equivalents, preferably from 0.9 to 1.1 equivalents, per equivalent of the ether bond-containing amine compound. By setting the amount of the sultone compound to be in the above range, the step of removing the unreacted material can be omitted or the time taken for the removal can be shortened.

The reaction of the ether bond-containing amine compound with the sultone compound can be carried out without a solvent or in the presence of an inert solvent.

Examples of the inert solvent to be used include an ether solvent such as diethyl ether, tetrahydrofuran, 1,2-dimethoxyethane or diglyme; and a nitrile solvent such as acetonitrile or propionitrile; A ketone solvent such as acetone or methyl ethyl ketone; an aromatic hydrocarbon solvent such as benzene, toluene or xylene.

When an inert solvent is used, the amount thereof to be used is not particularly limited, and is usually 100 parts by weight or less based on 1 part by weight of the amine compound containing an ether bond.

The reaction temperature is not particularly limited, and is usually -20 to 200 ° C, preferably 0 to 100 ° C, preferably 10 to 60 ° C. Further, the reaction can be carried out under normal pressure conditions, or can be carried out under pressure.

The reaction time is not particularly limited and is usually from 12 hours to 1 week, preferably from 24 to 96 hours.

From the viewpoint of preventing oxidation due to oxygen and causing a decrease in productivity due to hydrolysis of the sultone compound due to moisture in the air, the reaction is preferably carried out in an inert gas atmosphere such as a nitrogen gas.

The reaction can be carried out, for example, by gas chromatography, high speed liquid chromatography It is confirmed by ordinary analytical means such as instrument, thin layer chromatography, NMR, and IR.

After completion of the reaction, the target zwitterionic compound can be isolated by performing a usual post-treatment operation in organic synthesis chemistry. Further, the obtained zwitterionic compound can be purified by a conventional purification method such as solvent distillation, solvent washing, recrystallization, or column chromatography.

The zwitterionic compound of the present invention has a group represented by the above A ⁺ as a cationic group, a sulfonic acid group (-SO ₃ ^- ) as an anionic group, and a group having a carbon number of 2 to 20 having an ether bond.

The zwitterionic compound of the present invention having such a structure has ion conductivity, is excellent in solubility in an organic solvent, and has a low glass transition temperature and a low melting point.

The glass transition temperature of the zwitterionic compound of the present invention is not particularly limited, but is usually -100 to 150 ° C, preferably -80 to 50 ° C, and particularly preferably -60 to 20 ° C.

By using a zwitterionic compound having a glass transition temperature within the above range, an ion conductor having excellent ion conductivity can be obtained with good efficiency.

The melting point of the zwitterionic compound of the present invention is not particularly limited, and is usually 0 to 250 ° C, preferably 20 to 200 ° C. By using a zwitterionic compound having a melting point within the above range, an ion conductor in which the zwitterionic compound is not easily crystallized can be obtained with good efficiency.

The ion conductivity of the zwitterionic compound of the present invention is evaluated, for example, by measuring the ionic conductivity of a mixture obtained with a lithium salt.

For example, a mixture of the zwitterionic compound of the present invention and lithium bis(trifluoromethanesulfonyl) ruthenium amide (LiTFSI) (mixing ratio: 100 parts by weight relative to the zwitterionic compound, 100 parts by weight of LiTFSI) at 60 ° C The conductivity is usually 10 ^-8 to 10 ^-2 S/cm, preferably 10 ^-7 to 10 ^-2 S/cm, and particularly preferably 10 ^-6 to 10 ^-2 S/cm.

The solubility of the zwitterionic compound of the present invention in an organic solvent can be evaluated by dissolving it in an organic solvent such as chloroform or acetone.

For example, when the zwitterionic compound of the present invention is dissolved in chloroform or acetone at 25 ° C, it is preferred to prepare a solution having a concentration of 10 g/L or more, and it is preferred to prepare a solution having a concentration of 100 g/L or more. It is particularly preferable to be able to prepare a solution having a concentration of 200 g/L or more.

The measurement of the glass transition temperature and melting point, the ion conductivity measurement, and the solubility test described above can be carried out by the method described in the examples.

Because of these characteristics, the zwitterionic compound of the present invention can be suitably used as a proton conductor of a fuel cell, a lithium ion conductor of a lithium ion secondary battery, an antistatic agent, a dispersant, or the like.

2) Ion conductor

The ion conductor of the present invention contains a salt of a zwitterionic compound of the present invention and a metal of Group 1 or Group 2 of the periodic table.

The ion conductor is a substance from which metal ions derived from these metal salts can move relatively freely.

Examples of the metal ion constituting the metal salt include alkali metal ions such as lithium ions, sodium ions, and potassium ions; magnesium ions; alkaline earth metal ions such as calcium ions and barium ions.

Examples of the anion constituting the metal salt include bis(fluoromethanesulfonyl) ruthenium ion, bis(trifluoromethanesulfonyl) ruthenium ion, and bis(pentafluoroethylene). Sulfhydryl) quinone imine ion, ginseng (trifluoromethanesulfonyl) methide ion, trifluoromethanesulfonate ion, hexafluorophosphate ion, tetrafluoroborate ion, tetracyanoborate ion, perchlorination Acid ions, hexafluoroarsenic acid ions, and the like.

As the metal salt, a lithium salt, a sodium salt, a potassium salt or a magnesium salt is preferred, and a lithium salt is preferred.

Examples of the lithium salt include lithium bis(fluoromethanesulfonyl) quinone imide (LiN(SO ₂ CH ₂ F) ₂ ), lithium bis(trifluoromethanesulfonyl) ruthenium hydride (LiN (SO ₂ CF) ₃ ) ₂ ), lithium bis(pentafluoroethanesulfonyl) phthalide (LiN(SO ₂ C ₂ F ₅ ) ₂ ), ginseng (trifluoromethanesulfonyl) methylated lithium (LiC(SO ₂ CF) ₃ ) ₃ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium tetracyanoborate (LiB(CN) ₄ ), lithium perchlorate (LiClO ₄ ), lithium hexafluoroarsenate (LiAsF ₆ ), and the like.

In the present invention, the metal salt of Group 1 or Group 2 of the periodic table can be used singly or in combination of two or more.

The content of the metal salt in the ion conductor is usually from 1 to 1,000 parts by weight, preferably from 10 to 500 parts by weight, per 100 parts by weight of the zwitterionic compound.

The ion conductivity of the ion conductor of the present invention at 60 ° C is usually 10 ^-8 to 10 ^-2 S/cm, preferably 10 ^-6 to 10 ^-2 S/cm.

The glass transition temperature of the ion conductor of the present invention is usually -100 to 50 ° C, preferably -90 to 30 ° C.

The ion conductor of the present invention can use components in the electrolyte layer and the electrode as various electrochemical components.

In particular, a lithium ion conductor containing a lithium salt can be suitably used as a component in an electrolyte layer and an electrode of a lithium ion secondary battery.

The ion-conducting system of the present invention contains the zwitterionic compound of the present invention and has excellent flame retardancy. Therefore, by using the ion conductor of the present invention, an electrochemical component having high safety can be obtained.

[Examples]

Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited at all by the following examples.

The parts and % in each case are the weight basis as long as they are not notified in advance.

[Manufacturing Example 1]

5.0 g (52.6 mmol) of bis(2-methoxyethyl)amine and 2.5 g (26.7 mmol) of 2-chloroethyl methyl ether were added to the pressure vessel, and the whole contents were heated and reacted at 140 ° C for 48 hours. .

After completion of the reaction, the reaction liquid was distilled under reduced pressure to give a crude product. Next, this material was purified by an alumina column chromatography [developing solvent: ethyl acetate / n-hexane mixed solvent (1/1, vol / vol)] to obtain a bis(2-methoxyethyl group). Amine (yield: 2.51 g, yield: 32.9%).

[Example 1]

In a three-necked flask equipped with a cooling tube and a dropping funnel, 5.05 g (26.4 mmol) of gin (2-methoxyethyl)amine obtained in Production Example 1 and 25 ml of acetonitrile were added, and the contents were stirred at 25 ° C while stirring. 3.23 g (26.4 mmol) of 1,3-propane sultone was added, and after completion of the addition, the whole contents were refluxed for 48 hours.

After completion of the reaction, the solvent was distilled off from the reaction mixture under reduced pressure, and the residue was purified by an alumina column chromatography apparatus (developing solvent: chloroform/methanol mixed solvent (50/1, vol/vol)). The target (2-methoxyethyl)propane sulfonate ammonium (yield: 2.83 g, yield 34.2%) was obtained.

The ¹ H-NMR spectrum data of the target and the results of elemental analysis are shown below. ¹ H-NMR (CDCl ₃ , 500 MHz): δ = 1.87 (m, 2H), 2.46-2.49 (t, J = 7.5 Hz, 2H), 3.02 (s, 9H), 3.43 (m, 6H), 3.50 ( m,6H)

Anal Calc. for C ₁₂ H ₂₇ NO ₆ S, %: C, 45.99; H, 8.68; N, 4.47; S, 10.23; Found, %: C, 46.07; H, 8.43; N, 4.44; S, 10.29

[Embodiment 2]

In Example 1, the same procedure as in Example 1 was carried out except that gin[2-(2-methoxyethoxy)ethyl]amine was used instead of gin (2-methoxyethyl)amine. The target product [2-(2. methoxyethoxy)ethyl]propanesulfonic acid ammonium (yield: 2.60 g, yield: 32.3%) was obtained.

The ¹ H-NMR spectrum data of the target and the results of elemental analysis are shown below.

¹ H-NMR (CDCl ₃ , 500 MHz): δ = 2.23-2.29 (quin, J = 7.5 Hz, 2H), 2.85-2.87 (t, J = 6.7 Hz, 2H), 3.35 (s, 9H), 3.51 ( m, 6H), 3.64 (m, 6H), 3.79 (m, 6H) 3.83 (m, 2H), 3.95 (m, 6H)

Anal Calc. for C ₁₈ H ₃₉ NO ₉ S, %: C, 48.52; H, 8.82; N, 3.14; S, 7.20; Found, %: C, 48.20; H, 8.75; N, 3.12; S, 7.33

[Comparative Example 1]

In a three-necked flask equipped with a cooling tube and a dropping funnel, 2 g of tributylamine (10.8 mmol) and acetone (5 ml) were added, and while stirring the contents, 1,3-propane sultone 1.32 g (10.8 mmol) was gradually added thereto at 25 ° C. After the addition was completed, reflux was carried out for 48 hours.

After the reaction is completed, the precipitate is obtained by filtration and obtained by using acetone. The precipitate was washed to obtain an objective product of ammonium tributylpropanesulfonate (yield: 1.23 g, yield 37.00%).

The zwitterionic compounds obtained in Examples 1 and 2 and Comparative Example 1 were each subjected to the following measurements. (Determination of glass transition temperature of zwitterionic compounds)

Using a differential scanning calorimeter (SII NanoTechnology Co., Ltd., DSC7020), the zwitterionic compounds obtained in the examples and the comparative examples were obtained under the conditions of a flow rate of N ₂ gas of 40 ml/min and a temperature increase rate of 10 ° C/min. The glass transition temperature was measured from -100 ° C to +250 ° C. The results are shown in the first table.

(Solubility test of zwitterionic compounds)

The zwitterionic compounds obtained in the examples and the comparative examples were each dissolved in chloroform and acetone at 25 ° C, and the solubility was evaluated in accordance with the following criteria.

○: A solution having a concentration of 100 g/L or more can be prepared.

×: A solution having a concentration of 100 g/L or more cannot be prepared.

100 parts of the zwitterionic compound obtained in the examples and the comparative examples and 100 parts of lithium bis(trifluoromethanesulfonyl) ruthenium were added to 600 parts of methanol and uniformly mixed. After the methanol was distilled off from the mixture by an evaporator, the residue was dried at 120 ° C for 24 hours under reduced pressure to obtain a lithium ion conductor.

The following measurement was performed for each of the obtained ion conductors.

(Measurement of glass transition temperature of ion conductor)

The zwitterionic compound obtained in the examples and the comparative examples was used under the conditions of a N ₂ gas flow rate of 40 ml/min and a temperature increase rate of 10 ° C/min using a differential scanning calorimeter (DSC 7020, manufactured by SII NanoTechnology Co., Ltd.). The ion conductor obtained was heated from -100 ° C to +250 ° C and the glass transition temperature was measured.

The results are shown in the first table.

(Ion Conductivity Measurement of Ion Conductor)

A 300 μm-thick polytetrafluoroethylene spacer having a hole having a diameter of 8 mm was formed using a two-liquid hardening epoxy resin followed by a platinum electrode. Next, each of the holes is filled with the lithium ion conductor obtained as described above, and then a platinum electrode plate/lithium ion conductor is obtained by superposing another platinum electrode plate on the polytetrafluoroethylene spacer. / Sample for measurement of the layer structure of the platinum electrode plate.

The obtained measurement sample was placed in a battery evaluation unit manufactured by Toyo Systems Co., Ltd., using an Impedance Analyzer-1260 manufactured by Solartron Co., Ltd. at a temperature of 60 ° C (without humidification conditions), a measurement frequency of 5 to 1 MHz, and an applied voltage: The impedance was measured under conditions of 100 mV. In the thermostatic chamber, SH-241 manufactured by ESPEC Co., Ltd. was used, and the ion conductivity was calculated from the following formula using the resistance value obtained by the above measurement.

[In the above formula, each represents hereinafter as ionic conductivity (S/cm), d is the distance between electrodes (cm), R is resistance (Ω), and S is a sectional area (cm ² )].

The following situation is known from the first table.

The zwitterionic compounds of Examples 1 and 2 had a low glass transition temperature and a low melting point. Moreover, it has excellent solubility to chloroform and acetone. On the other hand, the solubility of the zwitterionic compound of Comparative Example 1 to chloroform and acetone was less than 10 g/L, and the solubility was inferior.

Further, the ion conductor obtained by using the zwitterionic compounds of Examples 1 and 2 has a low glass transition temperature and a high ion conductivity.

Claims (5)

A zwitterionic compound represented by the following formula (I), [Chem. 7] R ¹ -A ⁺ -X-SO ₃ ^- (I) [wherein R ¹ represents an ether having a nitrogen atom bonded to A ⁺ carbon number of bonds of the group (but with the atoms based carbon atom a nitrogen atom bonded to the a ⁺ a) 2 to 20, a ⁺ line represents a cationic group, X line represents the following formula (II) or of formula (III) a alkyl group having a carbon number of 2 to 5 bonded to the nitrogen atom of A ⁺ ], [wherein R ² is a group having 2 to 20 carbon atoms of an ether bond (however, an atomic carbon atom bonded to a nitrogen atom), an R ³ -based hydrogen atom, an alkyl group having 1 to 20 carbon atoms, and an ether; a bond having 2 to 20 carbon atoms (however, an atomic carbon atom bonded to a nitrogen atom), or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, * means a dangling bond], (wherein Y represents -C(R ¹² )(R ¹³ )-, -N(R ¹⁴ )-, -O-, or -S-, and R ⁴ to R ¹⁴ each independently represent a hydrogen atom or a carbon. A number of 1 to 10 alkyl groups, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, * means a dangling bond). The zwitterionic compound according to claim ¹ , wherein the number of ether bonds in the group having 2 to 20 carbon atoms of the ether bond of R ¹ , R ² and R ³ is independently from 1 to 5. The zwitterionic compound according to claim ¹ , wherein the bases of the above R ¹ , R ² and R ³ having an ether bond having 2 to 20 carbon atoms are each independently of the following formula (IV) to formula (IV). group VII) represented by any one of, [Formula ^{4] R 15 -OZ 1 - *} (IV) R 16 -OZ 2 -OZ 3 - * (V) R 17 -OZ 4 -OZ 5 -OZ 6 - * (VI) R ¹⁸ -OZ ⁷ -OZ ⁸ -OZ ⁹ -OZ ¹⁰ -* (VII) (wherein R ¹⁵ represents an alkyl group having 1 to 19 carbon atoms, and Z ¹ represents a carbon number of 1 to 19; The alkyl group has a total carbon number of R ¹⁵ and Z ¹ of 2 to 20, R ¹⁶ represents an alkyl group having 1 to 17 carbon atoms, Z ² represents an alkylene group having 2 to 18 carbon atoms, and Z ³ represents The alkyl group having 1 to 17 carbon atoms, the total carbon number of R ¹⁶ , Z ² and Z ³ is 4 to 20, and the R ¹⁷ is an alkyl group having 1 to 15 carbon atoms, and the Z ⁴ and Z ⁵ systems are each independently It represents an alkylene group having 2 to 16 carbon atoms, Z ⁶ represents an alkylene group having 1 to 15 carbon atoms, and the total number of carbon atoms of R ¹⁷ , Z ⁴ , Z ⁵ and Z ⁶ is 6 to 20, and R ¹⁸ represents The alkyl group having 1 to 13 carbon atoms, Z ⁷ , Z ⁸ and Z ⁹ each independently represent an alkylene group having 2 to 14 carbon atoms, and Z ¹⁰ is an alkylene group having 1 to 13 carbon atoms, R ¹⁸ and Z. ^7. The total carbon number of Z ⁸ , Z ⁹ and Z ¹⁰ is 8~20, and * is the dangling key). An ion conductor comprising two of the items as recited in claim 1 A ionic compound, and a salt of a metal of Group 1 or Group 2 of the periodic table. The ion conductor according to claim 4, wherein the metal salt is a lithium salt.