JP2003257240A - Ion conduction gel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion conduction gel that is easy in handling and processing and useful as a new electrolyte material and a new reaction medium for maintaining high ion conductivity, and the manufacturing method of the ion conduction gel. <P>SOLUTION: This is an ion conduction gel that contains a compound that is expressed by the formula R<SP>f1</SP>-[(CH<SB>2</SB>CR<SP>1</SP>COR<SP>2</SP>)<SB>p</SB>-(A)<SB>q</SB>]-R<SP>f2</SP>and an ionic liquid, and its manufacturing method. In the formula, R<SP>f1</SP>, R<SP>f2</SP>are each independently polyfluoro alkyl group, R<SP>1</SP>is hydrogen atom or a methyl group, R<SP>2</SP>is an organic group of univalence. A is a unit other than (CH<SB>2</SB>CR<SP>1</SP>COR<SP>2</SP>), p is a positive integer, and q is 0 or a positive integer. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ion conductive gel and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, studies have been conducted utilizing the unique characteristics of ionic liquids having high electrical conductivity which cannot be expected in non-aqueous systems. For example, it is expected to be used as an electrolyte for a lithium secondary battery and also as a solid electrolyte for a secondary battery, a capacitor and an electronic element by gelling.

As a method of gelling an ionic liquid,
For example, a method of gelling by dissolving a poly (vinylidene fluoride) -hexafluoropropylene copolymer in 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, or a method of N-alkoxyalkylimidazolium chloride is used. , Polymers, biopolymers, and molecular aggregates to be gelled
No. 02-3478) is known. However, in the gels obtained by these methods, the ionic liquid has a poor interaction with the polymer or the like as a support, and therefore has a problem such as leakage during processing.

[0004]

According to the present invention, by gelling an ionic liquid, problems such as leakage do not occur, handling and processing are easy, and the ionic liquid has the ionic conductivity. Since it retains high ionic conductivity without damaging it, it is also useful as a new electrolyte material.
Furthermore, it aims at providing the ion conductive gel which is useful also as a novel reaction medium expected to an ionic liquid. In particular, it is an object of the present invention to provide a method capable of obtaining an ionic conductive gel with high efficiency by directly gelling an ionic liquid without requiring a solvent for gelation.

[0005]

In order to solve the above-mentioned problems, the present invention provides a compound represented by the following formula 1 (hereinafter referred to as compound 1).
Also noted. ) And an ionic liquid (hereinafter, referred to as "gel of the present invention"). _{^{R f1 - [(CH 2 CR}} 1 COR 2) p - (A) q] -R f2 ··· Formula 1

In the present invention, an acyl peroxide having a polyfluoroalkyl group at both ends and a (meth) acrylic acid are reacted to have a polyfluoroalkyl group at both ends and a (meth) acrylic acid is obtained. There is provided a method for producing an ion-conducting gel, which comprises obtaining a compound containing a base unit and mixing the compound with an ionic liquid.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION
^f1 and R ^f2 are each independently a linear, branched or cyclic polyfluoroalkyl group (hereinafter referred to as Rf group).
Is. In the present specification, the polyfluoroalkyl group basically has a linear or branched alkyl group (including a cycloalkyl group) skeleton, and all or part of hydrogen atoms bonded to carbon atoms in the molecule. Is a group in which is substituted with a fluorine atom. The R ^f group preferably has 1 to 20 carbon atoms, and particularly preferably has 3 to 13 carbon atoms.

The R ^f group may contain a halogen atom other than a fluorine atom. A chlorine atom is preferable as the other halogen atom. An etheric oxygen atom or a thioetheric sulfur atom may be inserted between the carbon-carbon bonds in the R ^f group.

The number of fluorine atoms in the R ^f group is [(the number of fluorine atoms in the R ^f group) / (the number of hydrogen atoms contained in the corresponding alkyl group having the same carbon number as the R ^f group)] × 100 ( %), It is preferably 60% or more, and particularly 80%
The above is preferable.

Further, the R ^f group is preferably one in which a fluorine atom is bonded to the carbon atom at the terminal portion thereof. The R ^f group is preferably a perfluoroalkyl group (hereinafter referred to as R ^F group) in which all hydrogen atoms of an alkyl group (including a cycloalkyl group) are substituted with fluorine atoms.

As R ^f1 and R ^f2 , a group represented by the following formula 4 or 6 is preferable. - (CF _{2) s} X ··· Equation _{4 -CF (CF 3) O [} CF 2 CF (CF 3) O] t -C 3 F 7 ··· Formula _{5 -CF (CF 3) O [} CF 2 CF (CF ₃ )] _t −C ₆ F ₁₃ ... Equation 6

However, in the formula 2, s represents an integer of 1 to 10, and X represents a fluorine atom, a chlorine atom or a hydrogen atom. Moreover, in Formula 5 and 6, t shows the integer of 0-8.

As the group represented by the formula 4, in particular,-(C
_{F 2) 3 F, - (} CF 2) 4 F, - (CF 2) 5 F, -
_{(CF 2) 6 F, -} (CF 2) 7 F, - (CF 2)
_{8 F, - (CF 2)} 9 F, - (CF 2) 10 F are preferred. Further, as the groups represented by the formulas 5 and 6, groups in which t is an integer of 0 to 5 are particularly preferable.

The repeating structural unit (CH ₂ CR
^{In 1} COR ² ), R ¹ is a hydrogen atom or a methyl group, and R ² is a monovalent organic group. R ² is preferably a hydroxyl group, an alkoxyl group having 1 to 10 carbon atoms, or a group having a nitrogen atom and an oxygen atom having 1 to 10 carbon atoms. p is a positive integer and is not particularly limited, but 1 to 9
9 is preferable, and 1 to 95 is particularly preferable.

R ² is preferably selected according to the ionic liquid to be combined with compound 1. It is considered that the gelation is formed by the hydrogen bond between the compound 1 and the ionic liquid or the chemical bond based on the ionic bond, and it is preferably a group that increases these binding force with the ionic liquid, In particular, a zwitterion type group is preferable.

In compound 1, R ¹ is preferably a hydrogen atom, and R ² is preferably a group represented by the following formula 7. _{^{-N + H 2 C (CH 3}} ) 2 CH 2 SO 3 - ·· formula 7

The unit (CH ₂ CR ¹ CO in compound ¹
The ratio of R ² ) is not particularly limited, but is preferably 60 mol% or more, and particularly preferably 80 mol% or more.

The unit A in the formula 1 is (CH ₂ CR ¹ CO
It is a unit other than R ² ) and is not particularly limited. The unit A is not an essential unit in the compound 1.

As the unit A, for example, a monoolefin residue, a vinyl halide residue, a vinylidene halide residue, a styrene residue, a substituted styrene residue, an alkyl vinyl ether residue, a vinyl alkyl ketone residue and the like are preferably mentioned. To be

The unit A is water or an organic solvent in the case where the gelation property of the compound 1 to an ionic liquid or the solution is adjusted before being mixed with the ionic liquid for the purpose of shaping into a desired shape and gelling. It is preferable to select appropriately according to the purpose such as adjusting or improving the solubility in water, the adhesion to the object to be treated, the compatibility, the film-forming property or the antifouling property. q is 0 or a positive integer and is not particularly limited, but 0 or 1 to 98 is preferable, and 2 to 95 is particularly preferable.

In the present invention, compound 1 is R^fBoth bases
It has a terminal (CH₂CR¹COR²) And units
A compound containing A as a repeating structural unit,
(CH ₂CR¹COR²) And unit A, respectively
Block copolymer or random copolymer containing any proportion
It is the body.

When the sum of p and q is an integer of 2 to 100, the cohesive force resulting from the intermolecular interaction of the R ^f group is excellent, and the interaction with the ionic fluid is increased, resulting in gelation. It is preferable because a compound having excellent properties can be obtained.

Compound 1 may be produced by any method and is not particularly limited. For example, an acyl peroxide having R ^f groups at both terminals (hereinafter sometimes simply referred to as acyl peroxide), a unit (CH ₂ CR ¹ CO 2
(Meth) acrylic acids that give R ² ) (hereinafter sometimes simply referred to as (meth) acrylic acids), and a monomer that gives a unit A as necessary (hereinafter referred to as monomer A). Can be produced by a method of reacting.

R at both ends^fAs an acyl peroxide having a group
Of these, a compound represented by the following formula 4 is preferable. R^faC (= O) OOC (= O) R^fb... Equation 4 R in formula 4^fa, R^fbIs the same as in compound 1
Show the meaning. R^fa, R ^fbAre each independent R^fOn the basis
Yes, same R^fIt is preferably a group.

(Meth) acrylic acids have the formula CH₂= CR
¹COR²(However, R¹And R ²Is constant for Equation 1
Just as I meant it. The compound represented by these is preferable.

The total amount of the (meth) acrylic acid and the monomer A (hereinafter collectively referred to as a raw material monomer) used in the reaction for obtaining the compound 1 is in a molar ratio with respect to the acyl peroxide. It is preferably 1 to 500 times, especially 2 to 100 times.
A double amount is preferred. Within the above range, the generation of by-products due to the autolysis of acyl peroxide can be significantly suppressed,
Compound 1 is preferred because it can be obtained in high yield.

In the reaction, the compound 1 obtained by adjusting the amounts of the acyl peroxide and the raw material monomer
The molecular weight of can be adjusted. When the amount of acyl peroxide is increased, low molecular weight compound 1 is obtained, and when the amount of acyl peroxide is decreased, high molecular weight compound 1 is obtained.

As the reaction conditions, suitable conditions can be selected depending on the kind or the amount of the raw material monomer used. The reaction pressure is preferably normal pressure. The reaction temperature is preferably −20 ° C. to 150 ° C., particularly preferably 0 to 100 ° C. When the reaction temperature is within the above range, the reaction pressure does not become too high, and the reaction is completed in an appropriate time, which is preferable. In addition, the decomposition of acyl peroxide is not promoted and the reaction is easily controlled, which is preferable. It is preferable to set the reaction conditions so that the reaction time is 1 to 10 hours.

Compound 1 can be obtained by a one-step reaction under the above reaction conditions. In the reaction, in the acyl peroxide, the R ^f radical generated by thermal dissociation reacts with any carbon atom of the raw material monomer in a chain reaction. Further, in order to carry out the reaction more smoothly, it is preferable to use one or more solvents in the reaction.

As the solvent, organic solvents are preferable, and ethers, alcohols, hydrocarbons, amides, carboxylic acid esters, hydrocarbons having a fluorine atom and / or a chlorine atom are preferable. As the solvent, hydrocarbons having a fluorine atom and / or a chlorine atom, for the purpose of suppressing excessive decomposition of acyl peroxide and controlling the reaction,
Is particularly preferable.

As the organic solvent, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, dioxane, diethylene glycol dimethyl ether, tetrahydrofuran, methyl-tert-butyl ether,
Ethanol, isopropyl alcohol, n-butyl alcohol, toluene, xylene, hexane, formamide, dimethylformamide, acetamide, dimethylacetamide, ethyl acetate, butyl acetate, diethyl malonate, pentafluorodichloropropane, tridecafluorohexane, methylene chloride, etc. Preferred examples include:

The solvent used in the reaction may be one kind or a mixed solvent of two or more kinds. Moreover, you may use together an organic solvent and water. The amount of the solvent used in the reaction is preferably such that the concentration of the raw material monomer in the solvent is 1 to 50% by mass, and particularly 1
-20 mass% is preferable.

In the reaction, acyl peroxide also acts as a radical initiator, but a radical initiator other than acyl peroxide may be used in combination. Examples of other radical initiators include azo compounds, azoamidine compounds, redox compounds, and other peroxides. When these other radical initiators are used in combination, they react with acyl peroxide,
It is preferable because the reaction efficiency can be improved and the yield can be improved.

After the reaction, the resulting compound 1 may be used by isolating the solvent by distillation, or may be used in the state containing the solvent, unreacted starting materials and the like without isolation.

The gel of the present invention can be produced by a method of mixing the compound 1 obtained by the above method and an ionic liquid by ultrasonic treatment or the like.

The ionic liquid is not particularly limited,
Known ionic liquids can be used. For example, 1
-Ethyl-3-methyl-1H-imidazolium tetrachloroaluminate, 1-Ethyl-3-methyl-1H-imidazolium trifluoromethanesulfonate, 1-
Examples include imidazolium salts such as ethyl-3-methyl-1H-imidazolium tetrafluoroborate, pyridinium salts such as 1-butyl-pyridinium nitrate, and pyrazolium salts such as 1-methylmethylpyrazolium tetrafluoroborate. 1 represented by the following formula 2
Methylpyrazolium tetrafluoroborate is preferred.

[0037]

[Chemical 2]

Since the ionic liquid has a salt structure, especially when the compound 1 is a zwitterionic type group in which R ² in the formula 1 is represented by the above formula 7, other ionic liquids are used. There is an advantage that it can be directly gelated without using the solvent.

The gel of the present invention may contain various functional compounding agents, if necessary, in addition to the compound 1 and the ionic liquid. Preferred examples of the functional compounding agent include an ultraviolet absorber, an antioxidant, a surfactant and the like.

[0040]

EXAMPLES The present invention will be further described below with reference to examples. However, the present invention is not limited to this.

Synthesis Example 1 (Perfluoro-1-methyl-2
-Synthesis of 2-acrylamido-2-methylpropanesulfonic acid oligomer containing oxaoctyl group) 1,1-dichloro-2 containing perfluoro-2-methyl-3-oxanonanoyl peroxide (6.15 mmol)
In a solution of a mixture of 2,3,3,3-pentafluoropropane and 1,2-dichloro-1,1,2-trifluoroethane (Asahi Glass Co., Ltd., trade name AK-225) (220 g)
2-acrylamido-2-methylpropanoic acid (1
8.45 mmol, 3.82 g) in water (7.74)
g) was added, and the reaction was carried out at 45 ° C. for 5 hours under a nitrogen stream. The obtained product was swollen in water and added dropwise to a large excess of tetrahydrofuran for purification. The obtained product was dried under vacuum to obtain the desired product in a yield of 2.10 g. Identification data IR (cm ^-1 ) 1641 (C = O), 1310 (CF ₃ ), 1223 (CF ₂ )

Synthesis Example 2 (Perfluoro-1-methyl-2
-Synthesis of oxapentyl group-containing 2-acrylamido-2-methylpropanesulfonic acid oligomer) Other than using perfluoro-2-methyl-3-oxahexanoyl peroxide instead of perfluoro-2-methyl-3-oxanonanoyl peroxide Was synthesized in the same manner as in Synthesis Example 1. Identification data IR (cm ^-1 ) 1647 (C = O), 1304 (CF ₃ ), 1228 (CF ₂ ) ¹ H NMR (D ₂ O) δ 1.49 ~ 2.11 (CH ₂ ), 1.60 (CH ₃ ), 2.31 ~
2.69 (CH), 3.61~4.15 (CH 2); 19 F NMR (. D 2 O, ext CF 3 COOH) δ 1.56 - -5.10 (16F), -4
8.00 (6F).

Example 1 Perfluoro-1-methyl-2-oxaoctyl group-containing 2-acrylamido-2-methylpropanesulfonic acid oligomer obtained in Synthesis Example 1 (hereinafter referred to as Rf-AMPS-
C6) was added to 1-methylpyrazolium tetrafluoroborate and sonicated for 1 hour to solubilize it, and it was found that a colorless, transparent and uniform gel was formed. Then, when the gel forming concentration (Cmin) was measured at 30 ° C., it was 154 g / dm ³ .

Example 2 Perfluoro-1-methyl-2-oxapentyl group-containing 2-acrylamido-2-methylpropanesulfonic acid oligomer obtained in Synthesis Example 2 (hereinafter referred to as RF-AMPS-C
(Abbreviated as 3) was added to 1-methylpyrazolium tetrafluoroborate and sonicated to solubilize it, and it was found that a non-uniform gel with a part of white was formed. Therefore, the gel formation concentration (Cmin) should be measured in 3
When carried out at 0 ° C., it was 222 g / dm ³ .

Example 3 60.18 g of RF-AMPS-C was added to 1-methylpyrazolium tetrafluoroborate and a gel prepared at the concentration of Cmin measured in Example 1 was prepared by ultrasonication. The obtained gel was put in a Pyrex (registered trademark) glass cell, sandwiched between an upper electrode and a lower electrode made of brass, and the conductivity was measured at room temperature. In addition, the thickness of the gel was measured using a micro head. When the ionic conductivity (σ) was calculated from these measured values, a value of σ = 1.02 × 10 ⁻² S / cm was obtained.

Example 4 30.18 g of RF-AMPS-C was added to 1-methylpyrazolium tetrafluoroborate and a gel prepared to the concentration of Cmin measured in Example 2 was prepared by sonication. The obtained gel was put in a Pyrex glass cell, sandwiched between an upper electrode and a lower electrode made of brass, and the conductivity was measured at room temperature. In addition, the thickness of the gel was measured using a micro head. When the ionic conductivity (σ) was calculated from these measured values, σ = 6.07
A value of × 10 ^-3 S / cm was obtained.

Example 5 The same as Example 1 except that a 1: 1 (volume ratio) mixed solvent of 1-methylpyrazolium tetrafluoroborate and dimethyl sulfoxide was used in place of 1-methylpyrazolium tetrafluoroborate. Then, a colorless, transparent and uniform gel was prepared. At this time, the gel formation concentration (Cmi
n) was measured at 30 ° C., 137 g / dm
^{Was 3} .

Example 6 60.18 g of RF-AMPS-C was added to a mixed solvent of 1-methylpyrazolium tetrafluoroborate-dimethylsulfoxide (volume ratio 1: 1) to prepare a concentration of Cmin measured in Example 6. Prepared gel. The obtained gel was put in a Pyrex glass cell, sandwiched between an upper electrode and a lower electrode made of brass, and the conductivity was measured at room temperature. In addition, the thickness of the gel was measured using a micro head. Ionic conductivity (σ)
Was calculated, a value of σ = 5.7 × 10 ⁻³ S / cm was obtained.

As shown in Examples 1 to 6 above, it was found that the gel of the present invention can gel an ionic liquid and exhibits high ionic conductivity.

[0050]

INDUSTRIAL APPLICABILITY The gel of the present invention is easy to handle and process because it does not require a gelling solvent when gelling an ionic liquid without causing problems such as leakage. Since it retains high ionic conductivity without impairing its ionic conductivity, it is useful as a new electrolyte material and also as a new reaction medium expected for ionic liquids. In addition, the method of the present invention,
Since an ionic liquid can be directly gelled without requiring a solvent for gelation, an ionic conductive gel can be obtained with high efficiency.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01G 9/035 H01M 10/40 B // C07C 309/17 H01G 9/02 331F C07D 233/58 331H H01M 10 / 40 9/00 301G 9/02 311 (72) Inventor Kazuya Ohharu 1150 Hazawa-machi, Kanagawa-ku, Yokohama, Kanagawa Prefecture Asahi Glass Co., Ltd. (72) Inventor Hideo Sawada 572-7 Yao, Taharamoto-cho, Isojo-gun, Nara (72) Inventor Jun Kyokane 1180-1 F-term, Horen-cho, Nara, Nara (reference) 4H006 AA01 AB91 4J002 BG011 BG021 BG081 EU036 EU116 EU126 GQ00 5G301 CD01 CD10 5H029 AJ06 AM12 AM16 CJ08 DJ09

Claims (4)

[Claims] 1. An ion conductive gel containing a compound represented by the following formula 1 and an ionic liquid. _{^{R f1 - [(CH 2 CR}} 1 COR 2) p - (A) q] -R f2 ··· Formula 1 provided that the symbols in the formula 1 have the following meanings. R ^f1 and R ^f1 : each independently a polyfluoroalkyl group. R ¹ : a hydrogen atom or a methyl group. R ² : a monovalent organic group. A: Unit other than (CH ₂ CR ¹ COR ² ) p: Positive integer. q: 0 or a positive integer. 2. The ion conductive gel according to claim 1, wherein the ionic liquid is at least one selected from the group consisting of imidazolium salts, pyridinium salts and pyrazolium salts. 3. The ion conductive gel according to claim 1, wherein the ionic liquid is a compound represented by the following formula 2. [Chemical 1] 4. An acyl peroxide having a polyfluoroalkyl group at both ends and a (meth) acrylic acid are reacted to have a polyfluoroalkyl group at both ends and (meth)
A method for producing an ion-conducting gel, which comprises obtaining a compound containing a unit based on acrylic acid and mixing the compound with an ionic liquid.