JP2018006290A - Ion conductive composition and ion conductive membrane - Google Patents

Abstract

（Ａ^＋はカチオン性基又はカチオン性基含有基；Ｘ⁻は任意の対アニオン；Ｒは非イオン性基；ｎは１以上の整数；ｍは０以上の整数）
【選択図】なしDisclosed is an ion conductive composition that has an extremely low vapor pressure, has low flammability, and can provide an ion conductive film having excellent shape retention and re-solubility in a solvent.
An ion conductive composition containing an alkali metal salt in a proportion of 3 parts by weight or more with respect to 100 parts by weight of a polyether compound having a cationic group. It is preferable that the polyether compound having a cationic group is composed of a monomer unit represented by the formula (1).

(A ⁺ is a cationic group or a cationic group-containing group; X ⁻ is an arbitrary counter anion; R is a nonionic group; n is an integer of 1 or more; m is an integer of 0 or more)
[Selection figure] None

Description

  The present invention relates to an ion conductive composition containing an alkali metal salt. More specifically, the ion conductive film has an extremely low vapor pressure and a low flammability, and is excellent in shape retention and resolubility in a solvent. It is related with the ion conductive composition which can provide.

  In an electrochemical device such as a secondary battery, in order to obtain ionic conduction between electrodes, a liquid electrolyte obtained by dissolving an electrolyte salt in a solvent is usually used. On the other hand, in a liquid electrolyte using a solvent, there is a risk that the amount of liquid may decrease with time due to the volatilization of the solvent, or if the solvent is an organic solvent, there is a risk of ignition. It is being considered.

  As an alternative to an electrolyte using such an organic solvent, a polymer electrolyte such as a polyether has been studied. On the other hand, since the polymer electrolyte contains almost no volatile component, the vapor pressure is extremely low and flammability can be suppressed and liquid leakage can be prevented, but the shape stability is inferior under normal use environment. There was a case. In particular, when a material having inferior shape stability is used as a polymer electrolyte, there is a problem that the reliability of the electrochemical device is lowered. For such a problem, a polymer electrolyte capable of chemical crosslinking has been proposed. (For example, Patent Document 1).

  In such a chemically crosslinkable polymer electrolyte, a polymer electrolyte excellent in shape stability can be obtained because it is chemically crosslinked. However, since it forms a gel when chemically crosslinked, it cannot be redissolved in a solvent or the like. For this reason, there are problems that manufacturing conditions are restricted when manufacturing an electrochemical device, and usage conditions as an electrochemical device are restricted. In particular, rare metals may be used as electrode active materials in electrochemical devices. From the viewpoint of recovering such rare metals, in addition to being excellent in shape retention, etc. There has been a need for an electrolyte material that can be dissolved.

Japanese Patent Laid-Open No. 5-47210

  The present invention has been made in view of such a situation, and provides an ion conductive membrane having an extremely low vapor pressure, low flammability, and excellent shape retention and re-solubility in a solvent. It is an object of the present invention to provide an ion conductive composition that can be used. Another object of the present invention is to provide an ion conductive membrane obtained using such an ion conductive composition.

  As a result of intensive studies to achieve the above object, the present inventors have found that an ion conductive composition containing an alkali metal salt in a proportion of 3 parts by weight or more with respect to 100 parts by weight of a polyether compound having a cationic group. According to the present invention, it was found that the vapor pressure is extremely low and the flammability is suppressed, and that it is possible to provide an ion conductive membrane excellent in shape retention and re-solubility in a solvent, and the present invention has been completed. .

  That is, according to this invention, the ion conductive composition which contains an alkali metal salt in the ratio of 3 weight part or more with respect to 100 weight part of polyether compounds which have a cationic group is provided.

（上記一般式（１）中、Ａ^＋は、カチオン性基またはカチオン性基含有基を表し、Ｘ⁻は、任意の対アニオンを表し、Ｒは非イオン性基を表し、ｎは１以上の整数であり、ｍは０以上の整数である。）
また、本発明のイオン伝導性組成物において、前記アルカリ金属塩が、ＬｉＢＦ_４、ＬｉＰＦ_６、ＬｉＣｌＯ_４、ＬｉＮ（ＳＯ_２Ｆ）_２、およびＬｉＮ（ＳＯ_２ＣＦ_３）_２から選択される少なくとも一種であることが好ましい。 In the ion conductive composition of the present invention, the polyether compound having a cationic group is preferably composed of a monomer unit represented by the following general formula (1).

(In the above general formula (1), A ⁺ represents a cationic group or a cationic group-containing group, X ⁻ represents an arbitrary counter anion, R represents a nonionic group, and n represents 1 or more. (It is an integer, and m is an integer of 0 or more.)
In the ion conductive composition of the present invention, the alkali metal salt is at least one selected from LiBF ₄ , LiPF ₆ , LiClO ₄ , LiN (SO ₂ F) ₂ , and LiN (SO ₂ CF ₃ ) _2. It is preferable that

  Furthermore, according to this invention, the ion conductive film which consists of an ion conductive composition of the said invention is provided.

  According to the present invention, there is provided an ion conductive composition having an extremely low vapor pressure, suppressing flammability, and capable of providing an ion conductive film excellent in shape retention and re-solubility in a solvent. An ion conductive membrane obtained using such an ion conductive composition can be provided.

<Ion conductive composition>
The ion conductive composition of the present invention is an ion conductive composition containing a polyether compound having a cationic group and an alkali metal salt, and is based on 100 parts by weight of the polyether compound having a cationic group. The alkali metal salt is contained in a proportion of 3 parts by weight or more.

<Alkali metal salt>
The alkali metal salt is a salt compound composed of a cation and an anion as long as it contains an alkali metal cation as a cation, and is not particularly limited, but an alkali having only one positive charge as a cation. A salt compound having a metal cation and a counter anion having only one negative charge is preferable.

  Specific examples of the alkali metal cation forming the alkali metal salt include lithium ion, sodium ion, potassium ion, rubidium ion, cesium ion, francium ion and the like. Among these, lithium ion, sodium ion, and potassium ion are preferable, lithium ion and sodium ion are more preferable, and lithium ion is particularly preferable.

Specific examples of the anion that forms the alkali metal salt include halide ions such as Cl ⁻ , Br ⁻ and I ⁻ , (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , (CF ₃ CF ₂ SO ₂ ) sulfonimide compounds such as ₂ N ⁻ , OH ⁻ , SCN ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , CF ₃ COO ⁻ , PhCOO ⁻ However, it is not limited to these. Among these, (CF ₃ SO ₂ ) ₂ N ⁻ , (FSO ₂ ) ₂ N ⁻ , BF ₄ ⁻ , PF ₆ ⁻ and ClO ₄ ⁻ are preferable, and (CF ₃ SO ₂ ) ₂ N ⁻ and BF ₄ ⁻ , PF ₆ ^- is more preferable, and (CF ₃ SO ₂ ) ₂ N ^- is particularly preferable.

  As the alkali metal salt used in the present invention, all of the cation and the anion may be composed of the same ionic species, or two or more ionic species are mixed as one or both of the cation and the anion. It may be what you did. That is, as an alkali metal salt, a single thing may be sufficient and 2 or more types may be mixed.

Specific examples of the alkali metal salt used in the present invention include LiBF ₄ , LiPF ₆ , LiClO ₄ , LiN (SO ₂ F) ₂ , LiN (SO ₂ CF ₃ ) ₂ , NaBF ₄ , NaPF ₆ , NaClO ₄ , NaN ( SO ₂ F) ₂ , NaN (SO ₂ CF ₃ ) _{2 and the} like. Among these, LiBF ₄ , LiPF ₆ , LiClO ₄ , LiN (SO ₂ F) ₂ , and LiN (SO ₂ CF ₃ ) ₂ are preferable, and LiBF ₄ , LiPF ₆ , and LiN (SO ₂ CF ₃ ) ₂ are more preferable. LiN (SO ₂ CF ₃ ) ₂ is particularly preferred.

<Polyether compound having a cationic group>
The polyether compound having a cationic group used in the present invention is a polyether compound comprising an oxirane monomer unit, which is a unit obtained by ring-opening polymerization of an oxirane structure portion of a compound containing an oxirane structure. And having a cationic group in the molecule.

According to the present invention, by containing an alkali metal salt in a proportion of 3 parts by weight or more with respect to 100 parts by weight of a polyether compound having a cationic group, the vapor pressure is extremely low, and the flammability is suppressed. It is possible to provide an ion conductive composition capable of providing an ion conductive membrane excellent in shape retention and re-solubility in a solvent.
In particular, the present inventors have conducted extensive studies to solve the problem of achieving both shape retention and re-solubility in a solvent in an ion conductive composition containing an alkali metal salt. According to the composition obtained by blending a predetermined amount or more of the alkali metal salt with respect to the polyether compound having the above, it is possible to obtain an ion conductive membrane having excellent shape retention without chemical crosslinking, The obtained ion-conducting membrane was found to have re-solubility in a solvent because it has shape retention without chemical cross-linking, and based on such knowledge, the present invention has been completed. Is.

  Specific examples of the oxirane monomer unit that forms the polyether compound having a cationic group used in the present invention include alkylene oxide monomer units such as ethylene oxide units, propylene oxide units, and 1,2-butylene oxide units; Epihalohydrin monomer units such as epichlorohydrin units, epibromohydrin units, epiiodohydrin units; alkenyl group-containing oxirane monomer units such as allyl glycidyl ether units; aromatic ether groups such as phenyl glycidyl ether units Examples thereof include, but are not limited to, containing oxirane monomer units; (meth) acryloyl group-containing oxirane monomer units such as glycidyl acrylate units and glycidyl methacrylate units.

  The polyether compound having a cationic group used in the present invention may contain two or more oxirane monomer units. In this case, the distribution pattern of the plurality of repeating units is not particularly limited. However, it is preferable to have a random distribution.

  The polyether compound having a cationic group used in the present invention contains an oxirane monomer unit having a cationic group as at least a part of the oxirane monomer unit.

  Although it does not specifically limit as a cationic group which can be contained in the polyether compound which has a cationic group used by this invention, From a viewpoint that the shape retainability of the ion conductive film obtained can be improved more, a periodic table | surface. The group 15 or group 16 atom is preferably a cationic group having an onium cation structure, and the nitrogen atom is more preferably a cationic group having an onium cation structure. More preferably, the nitrogen atom in the ring is a cationic group having an onium cation structure, and the nitrogen atom in the imidazolium ring is particularly preferably a cationic group having an onium cation structure.

  Specific examples of the cationic group include ammonium group, methylammonium group, butylammonium group, cyclohexylammonium group, anilinium group, benzylammonium group, ethanolammonium group, dimethylammonium group, diethylammonium group, dibutylammonium group, and nonylphenylammonium. Group, trimethylammonium group, triethylammonium group, n-butyldimethylammonium group, n-octyldimethylammonium group, n-stearyldimethylammonium group, tributylammonium group, trivinylammonium group, triethanolammonium group, N, N-dimethyl Ammonium groups such as ethanolammonium group, tri (2-ethoxyethyl) ammonium group; piperidinium group, 1-pyrrolidinium Group, 1-methylpyrrolidinium group, imidazolium group, 1-methylimidazolium group, 1-ethylimidazolium group, benzimidazolium group, pyrrolium group, 1-methylpyrrolium group, oxazolium group, benzoxazolium group Group, benzisoxazolium group, pyrazolium group, isoxazolium group, pyridinium group, 2,6-dimethylpyridinium group, pyrazinium group, pyrimidinium group, pyridazinium group, triazinium group, N, N-dimethylanilinium group, A group comprising a heterocyclic ring containing a cationic nitrogen atom such as quinolinium group, isoquinolinium group, indolinium group, isoindolinium group, quinoxalium group, isoquinoxalium group, thiazolium group; triphenylphosphonium salt, tributyl Phosphonium group, etc. Groups comprising a cationic phosphorus atom; but like, but is not limited thereto. Among these, it comprises a heterocyclic ring containing a cationic nitrogen atom such as 1-methylpyrrolidinium group, imidazolium group, 1-methylimidazolium group, 1-ethylimidazolium group, benzimidazolium group, etc. Groups are preferred.

In addition, the cationic group usually has a counter anion, but the counter anion is not particularly limited. For example, a halide ion such as Cl ⁻ , Br ⁻ or I ⁻ or (FSO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , sulfonimide compounds such as (CF ₃ CF ₂ SO ₂ ) ₂ N ⁻ , OH ⁻ , SCN ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , CF ₃ COO ⁻ , PhCOO ^{− and the} like can be mentioned. These counter anions may be appropriately selected according to the characteristics of the ion conductive membrane to be obtained.

  In the polyether compound having a cationic group used in the present invention, at least a part of the oxirane monomer units constituting the polyether compound may be an oxirane monomer unit having a cationic group. All of the oxirane monomer units constituting the polyether compound may have a cationic group, or an oxirane monomer unit having a cationic group and an oxirane monomer having no cationic group Units may be mixed. In the polyether compound having a cationic group used in the present invention, the proportion of the oxirane monomer unit having a cationic group is not particularly limited, and the oxirane monomer unit constituting the polyether compound having a cationic group 0.1 mol% or more is preferable with respect to the whole, 1 mol% or more is more preferable, and 10 mol% or more is especially preferable. In addition, the upper limit of the ratio for which the oxirane monomer unit which has a cationic group accounts is not specifically limited. By making the ratio which the oxirane monomer unit which has a cationic group occupies the said range, the shape maintenance property of the obtained ion conductive film can be made more excellent.

（上記一般式（１）中、Ａ^＋は、カチオン性基またはカチオン性基含有基を表し、Ｘ⁻は、任意の対アニオンを表し、Ｒは非イオン性基を表し、ｎは１以上の整数であり、ｍは０以上の整数である。） Although it does not specifically limit as a structure of the polyether compound which has a cationic group used by this invention, It is preferable that it is what consists of a monomer unit represented by following General formula (1).

(In the above general formula (1), A ⁺ represents a cationic group or a cationic group-containing group, X ⁻ represents an arbitrary counter anion, R represents a nonionic group, and n represents 1 or more. (It is an integer, and m is an integer of 0 or more.)

In the general formula (1), A ⁺ represents a cationic group or a cationic group-containing group, and specific examples of the cationic group include those described above. As the cationic group-containing group, The group containing the cationic group mentioned above is mentioned.

In the general formula (1), X ⁻ represents an arbitrary counter anion. For example, specific examples of the counter anion include those described above.

In the general formula (1), R is a nonionic group and is not particularly limited as long as it is a nonionic group. R is, for example, a hydrogen atom; an alkyl group having 1 to 10 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a t-butyl group; a vinyl group or an allyl group. Group, alkenyl group having 2 to 10 carbon atoms such as propenyl group; alkynyl group having 2 to 10 carbon atoms such as ethynyl group and propynyl group; 3 to 20 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclopentyl group and cyclohexyl group A C6-C20 aryl group such as a phenyl group, a 1-naphthyl group, and a 2-naphthyl group;
Among these, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an alkynyl group having 2 to 10 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms May have a substituent at any position.
Examples of the substituent include an alkyl group having 1 to 6 carbon atoms such as a methyl group and an ethyl group; an alkoxy group having 1 to 6 carbon atoms such as a methoxy group, an ethoxy group and an isopropoxy group; and a carbon number such as a vinyloxy group and an allyloxy group. 2-6 alkenyloxy groups; aryl groups optionally having substituents such as phenyl group, 4-methylphenyl group, 2-chlorophenyl group, 3-methoxyphenyl group; fluorine atom, chlorine atom, bromine atom, etc. Halogen atoms of 1 to 6 carbon atoms such as methylcarbonyl group and ethylcarbonyl group; (meth) acryloyloxy groups such as acryloyloxy group and methacryloyloxy group; and the like.

  In the general formula (1), n is an integer of 1 or more, and m may be an integer of 0 or more, but n is preferably an integer of 1 to 10,000, 2-9 More preferably, it is an integer of 1,000, more preferably an integer of 5-8000. M is preferably an integer of 0 to 9,999, more preferably an integer of 0 to 8,998, and still more preferably an integer of 0 to 7,995. N + m is preferably an integer of 1 to 10,000, more preferably an integer of 2 to 9,000, and further preferably an integer of 5 to 8,000.

  In addition, when the structure of the polyether compound having a cationic group used in the present invention is a monomer unit represented by the general formula (1), the polymer chain end is not particularly limited, It can be any group. Examples of the polymer chain end group include the above-described cationic group, hydroxyl group, or hydrogen atom.

  The number average molecular weight (Mn) of the polyether compound having a cationic group used in the present invention is not particularly limited, but is preferably 500 to 2,000,000, and preferably 1,000 to 1,000,000. More preferred. Further, the weight average molecular weight (Mw) of the polyether compound having a cationic group used in the present invention is not particularly limited, but is preferably 500 to 6,000,000, and 1,000 to 3,000,000. The molecular weight distribution (Mw / Mw) is preferably 1.0 to 3.0, more preferably 1.0 to 2.0. In addition, the number average molecular weight, weight average molecular weight, and molecular weight distribution of the polyether compound having a cationic group can be determined by the method described in Examples described later.

  In addition, the chain structure of the polyether compound having a cationic group used in the present invention is not particularly limited, and may be a linear structure or a chain structure having a branched structure such as a graft shape or a radial shape. May be.

The synthesis method of the polyether compound having a cationic group used in the present invention is not particularly limited, and any synthesis method can be adopted as long as the target compound can be obtained. As an example of the synthesis method, first, a base polymer (polyether compound having no cationic group) is obtained by the following method (A) or (B).
(A) A monomer containing an oxirane monomer including at least an epihalohydrin such as epichlorohydrin, epibromohydrin, epiiodohydrin, etc. is disclosed in JP 2010-53217 A as a catalyst. In the presence of a catalyst comprising an onium salt of a compound containing a group 15 or 16 atom of the periodic table and a trialkylaluminum in which all of the alkyl groups contained are linear alkyl groups. A method of obtaining a base polymer by ring-opening polymerization.
(B) A monomer containing an oxirane monomer including at least an epihalohydrin such as epichlorohydrin, epibromohydrin, epiiodohydrin, etc. is disclosed in JP-B-46-27534. A method for obtaining a base polymer by ring-opening polymerization in the presence of a catalyst obtained by reacting phosphoric acid and triethylamine with isobutylaluminum.

  Then, by reacting the base polymer obtained in the above method (A) or (B) with an amine compound such as an imidazole compound, the halogen group constituting the epihalohydrin monomer unit of the base polymer is converted into an onium halide group. A polyether compound having a cationic group can be obtained by performing an anion exchange reaction on the halide ions constituting the onium halide group, if necessary.

  In the ion conductive composition of the present invention, the content of the alkali metal salt with respect to 100 parts by weight of the polyether compound having a cationic group is 3 parts by weight or more, preferably 4 parts by weight or more, more preferably 5 parts. Part by weight or more, more preferably 8 parts by weight or more, and particularly preferably 10 parts by weight or more. If the content ratio of the alkali metal salt is too small, the shape-retaining property of the resulting ion conductive membrane will be insufficient. The upper limit of the content ratio of the alkali metal salt in the ion conductive composition of the present invention is not particularly limited as long as it is an amount that can be dissolved in the polyether compound having a cationic group, preferably 500. It is not more than parts by weight, more preferably not more than 400 parts by weight, still more preferably not more than 300 parts by weight, particularly preferably not more than 200 parts by weight.

<Method for producing ion-conductive composition>
The ion conductive composition of this invention can be manufactured by mixing an alkali metal salt with the polyether compound which has a cationic group mentioned above. It does not specifically limit as a mixing method, A well-known method can be used without a restriction | limiting. In mixing, mixing may be performed in a solvent. The solvent to be used is not particularly limited, but ethers such as tetrahydrofuran and anisole; esters such as ethyl acetate and ethyl benzoate; ketones such as acetone, 2-butanone and acetophenone; acetonitrile, dimethylformamide, dimethylacetamide, dimethylsulfoxide, N -Aprotic polar solvents such as methylpyrrolidone; protic polar solvents such as ethanol, methanol, water; and the like. These solvents may be used alone or as a mixed solvent of two or more.

<Other ingredients>
Further, the ion conductive composition of the present invention may contain other components in addition to the polyether compound having a cationic group and an alkali metal salt within a range not impairing the effects of the present invention. Good. Specific examples of other components include water, methanol, ethanol, toluene, acetone, THF, ethylene carbonate, propylene carbonate, dimethyl carbonate, vinylene carbonate, γ-butyrolactone, low molecular weight compounds; room temperature molten salts (ionic liquids, Salt compounds other than alkali metal salts such as ionic liquids; nanocarbons such as carbon nanotubes, graphite, graphene, and graphene oxide; metal oxynitrides such as zinc oxide, magnesium oxide, boron nitride, and gallium nitride; However, it is not limited to these.

<Ion conductive membrane>
The ion conductive film of the present invention is a film-shaped molded article having ion conductivity made of the above-described ion conductive composition of the present invention.

  The ion conductive membrane of the present invention includes, for example, each component constituting the above-described ion conductive composition of the present invention (a polyether compound having a cationic group, an alkali metal salt, and other components used as necessary). ) Is dissolved in a solvent to prepare an ion conductive composition solution, which is formed into a film and dried.

  The thickness of the ion conductive membrane of the present invention is preferably 1 to 2000 μm, more preferably 5 to 1500 μm, and still more preferably 10 to 1000 μm. By setting the thickness in the above range, it is possible to suitably function as an ion conductive film while sufficiently ensuring reliability.

  Since the ion conductive membrane of the present invention is obtained by using the above-described ion conductive composition of the present invention, the vapor pressure is extremely low and the flammability is suppressed. It has excellent solubility. In particular, since the ion conductive membrane of the present invention can realize excellent shape retention without chemical crosslinking, it has excellent re-solubility in a solvent and can be reused because it can be dissolved in a solvent. It has excellent properties. Specifically, in the manufacturing process for manufacturing various devices and the like, when the ion conductive film of the present invention is formed on another member, even if there is any problem, the ion conductive film of the present invention is Since it can be removed by dissolving in a solvent, other members can be suitably reused. Furthermore, the ion conductive membrane itself can also be reused as an ion conductive composition. .

  Therefore, the ion conductive film of the present invention can be suitably used in applications such as electrochemical devices such as secondary batteries, fuel cells, dye-sensitized solar cells, and actuators, taking advantage of such characteristics.

  Hereinafter, although this invention is demonstrated based on a more detailed Example, this invention is not limited to these Examples. In the following, “part” and “%” are based on weight unless otherwise specified. Moreover, the test and evaluation followed the following.

(1) Number average molecular weight (Mn) and molecular weight distribution (Mw / Mn)
The number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) of the base polymer (polyether compound having no cationic group) were measured as polystyrene equivalent values by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent. . In addition, HLC-8320 (manufactured by Tosoh Corp.) is used as a measuring device, four TSKgel SuperMultipore HZ-H (manufactured by Tosoh Corp.) are connected in series, and a differential refractometer RI-8320 (Tosoh Corp.) is used as a measuring instrument. Made).
Moreover, the number average molecular weight (Mn) of the polyether compound which has a cationic group was calculated | required as follows. That is, first, the average molecular weight of the repeating unit of the base polymer (polyether compound having no cationic group), the average molecular weight of the oxirane monomer unit having a cationic group, and the cationic group determined by the following (2) The average molecular weight of all repeating units constituting the polyether compound having a cationic group was determined from the content of the oxirane monomer unit having. And the value obtained by multiplying the number of repeating units of the base polymer (polyether compound having no cationic group) and the average molecular weight of all repeating units constituting the polyether compound having a cationic group is The number average molecular weight of the polyether compound having a cationic group.

(2) Structure of polyether compound having cationic group and content of oxirane monomer unit having cationic group Structure of polyether compound having cationic group, and polyether compound having cationic group, The content of the oxirane monomer unit having a cationic group was measured as follows using a nuclear magnetic resonance apparatus (NMR). That is, first, 30 mg of a polyether compound having a cationic group as a sample was added to 1.0 mL of deuterated chloroform or deuterated dimethyl sulfoxide, and shaken for 1 hour to dissolve uniformly. And the NMR measurement was performed about the obtained solution, the < ¹ > H-NMR spectrum was obtained, and the structure of the polyether compound was assigned according to the usual method.
Moreover, the content rate of the oxirane monomer unit which has a cationic group in the polyether compound which has a cationic group was computed with the following method. That is, first, the number of moles B1 of all oxirane monomer units was calculated from the integral value of protons derived from the main chain oxirane monomer units. Next, the number of moles B2 of the oxirane monomer unit having a cationic group was calculated from the integral value of protons derived from the cationic group. And the ratio (percentage) of B2 with respect to B1 was calculated | required as content rate of the oxirane monomer unit which has a cationic group in the polyether compound which has a cationic group.

(3) Shape retention The glass plate on which the ion conductive film (membrane molded body) is formed is held vertically and allowed to stand for 24 hours. The shape retention property was evaluated by confirming that it was not deformed by its own weight. Even after the elapse of 24 hours, if the ion conductive membrane (film molded body) is not deformed by its own weight and the thickness is kept uniform, it is determined that “the shape is retained”. After the passage of time, when the ion conductive membrane (membrane molded body) flowed by its own weight and the thickness uniformity was lost, it was judged as “no shape retention”.

[Production Example 1]
(Living anion copolymerization of epichlorohydrin and glycidyl methacrylate)
To a glass reactor equipped with a stirrer substituted with argon, 0.322 g of tetranormalbutylammonium bromide and 5 ml of toluene were added and cooled to 0 ° C. Next, 0.137 g of triethylaluminum (1.2 equivalents relative to tetranormalbutylammonium bromide) dissolved in 0.25 ml of normal hexane was added and reacted for 15 minutes to obtain a catalyst composition. To the obtained catalyst composition, 9.5 g of epichlorohydrin and 0.5 g of glycidyl methacrylate were added, and a polymerization reaction was performed at 0 ° C. After the polymerization reaction started, the viscosity of the solution gradually increased. After reacting for 1 hour, a small amount of 2-propanol was added to the polymerization reaction solution to stop the reaction. Subsequently, after diluting the obtained polymerization reaction liquid with toluene, it poured into 2-propanol and obtained 9.8g of white rubber-like substances. The rubbery substance obtained had a number average molecular weight (Mn) of 10,100 as measured by GPC and a molecular weight distribution of 1.20. Further, when ¹ H-NMR measurement was performed on the obtained rubber-like substance, it was confirmed that this rubber-like substance contained 97.0 mol% of epichlorohydrin units and 3.0 mol% of glycidyl methacrylate units. did it. From the above, the obtained rubber-like substance has a polyether compound A having an bromomethyl group at the polymerization initiation terminal and a hydroxyl group at the polymerization termination terminal and composed of epichlorohydrin units and glycidyl methacrylate units (on average, epichloromethane). 110 mer consisting of 106 hydrin units and 4 glycidyl methacrylate units).

[Production Example 2]
(Quaternization of epichlorohydrin unit in polyether compound A with 1-methylimidazole)
8.0 g of the polyether compound A obtained in Production Example 1, 22.0 g of 1-methylimidazole, and 16.0 g of N, N-dimethylformamide were added to a glass reactor equipped with a stirrer substituted with argon, Heated to 80 ° C. After reacting at 80 ° C. for 144 hours, the reaction was stopped by cooling to room temperature, and a part of the obtained reaction solution was taken out and dried under reduced pressure at 50 ° C. for 120 hours. Obtained. This resinous material was subjected to ¹ H-NMR measurement and elemental analysis. As a result, chloro groups in all epichlorohydrin units in the polyether compound A obtained in Production Example 1 of the starting material were 1-methyl Identified as polyether compound B having 1-methylimidazolium halide group, in which bromo groups of all bromomethyl groups at the polymerization initiation terminal are substituted with 1-methylimidazolium bromide groups on imidazolium chloride groups, respectively. It was done.

[Production Example 3]
(Anion exchange of polyether compound B having 1-methylimidazolium halide group with lithium bis (trifluoromethanesulfonyl) imide)
300 ml of distilled water in which 26.0 g of lithium bis (trifluoromethanesulfonyl) imide was dissolved was added to a glass reactor equipped with a stirrer. Separately, 5.0 g of the polyether compound B having a 1-methylimidazolium halide group obtained in Production Example 2 was dissolved in 50 ml of distilled water, and this was dropped into the glass reactor and allowed to stand at room temperature for 30 minutes. Reacted. After the reaction, the precipitated rubber-like substance was collected and dissolved in acetone, and then the acetone solution was dropped into 300 ml of distilled water to remove inorganic salts by polymer coagulation. The rubber-like substance obtained by coagulation was dried under reduced pressure at 50 ° C. for 12 hours to obtain 11.5 g of a light brown rubber-like substance. The obtained rubber-like substance was subjected to ¹ H-NMR measurement and elemental analysis. As a result, 1 in the repeating unit of the polyether compound B having a 1-methylimidazolium halide group obtained in Production Example 2 as a starting material. -Bis (trifluoromethanesulfonyl) as a counter anion, in which all chloride ion of methylimidazolium chloride group and bromide ion of 1-methylimidazolium bromide group at the polymerization initiation terminal were exchanged for bis (trifluoromethanesulfonyl) imide anion It was identified as an imidazolium structure-containing polyether compound C having an imide anion. In addition, the number average molecular weight (Mn) of the obtained polyether compound C was 45,000.

[Production Example 4]
(Anion exchange of polyether compound B having 1-methylimidazolium halide group with potassium hexafluorophosphate)
50 ml of acetonitrile in which 9.7 g of potassium hexafluorophosphate was dissolved was added to a glass reactor equipped with a stirrer. Separately, 5.0 g of the polyether compound B having 1-methylimidazolium halide group obtained in Production Example 2 was dissolved in 100 ml of methanol, and this was dropped into the glass reactor and reacted at room temperature for 30 minutes. I let you. The precipitated light brown rubber-like substance was collected and dissolved in acetone, and then the acetone solution was dropped into 300 ml of distilled water to remove inorganic salts by polymer coagulation. The rubber-like substance obtained by coagulation was dried under reduced pressure at 50 ° C. for 12 hours to obtain 8.0 g of a brown rubber-like substance. The obtained rubber-like substance was subjected to ¹ H-NMR measurement and elemental analysis. As a result, 1 in the repeating unit of the polyether compound B having a 1-methylimidazolium halide group obtained in Production Example 2 as a starting material. An imidazolium having a hexafluorophosphate anion as a counter anion, in which all of the chloride ion of the methylimidazolium chloride group and the bromide ion of the 1-methylimidazolium bromide group at the polymerization initiation terminal are exchanged for the hexafluorophosphate anion It was identified as structure-containing polyether compound D. The number average molecular weight (Mn) of the obtained polyether compound D was 30,600.

[Production Example 5]
(Quaternization of epichlorohydrin unit in polyether compound A with 1-methylpyrrolidine)
In a glass reactor with a stirrer, 4.0 g of polyether compound A obtained in the same manner as in Production Example 1, 11.4 g of 1-methylpyrrolidine, and 8.0 g of N, N-dimethylformamide were replaced with argon. Added and heated to 80 ° C. After reacting at 80 ° C. for 144 hours, the reaction was stopped by cooling to room temperature. A part of the obtained reaction solution was extracted and dried under reduced pressure at 50 ° C. for 120 hours to obtain 7.7 g of a light brown resinous substance. When ¹ H-NMR measurement and elemental analysis were performed on this resinous substance, chloro groups in all epichlorohydrin units in the starting polyether compound A were converted to 1-methylpyrrolidinium chloride groups. It was identified as polyether compound E having a 1-methylpyrrolidinium halide group in which all bromomethyl groups at the polymerization initiation terminal were each substituted with a 1-methylpyrrolidinium bromide group.

[Production Example 6]
(Anion exchange of polyether compound E having 1-methylpyrrolidinium halide group with lithium bis (trifluoromethanesulfonyl) imide)
300 ml of distilled water in which 26.0 g of lithium bis (trifluoromethanesulfonyl) imide was dissolved was added to a glass reactor equipped with a stirrer. Separately from this, 7.7 g of the polyether compound E having 1-methylpyrrolidinium halide group obtained in Production Example 5 was dissolved in 100 ml of distilled water, and this was dropped into the glass reactor and added at room temperature. Reacted for 1 minute. After the reaction, the precipitated light brown rubber-like substance was collected and dissolved in acetone, and then the acetone solution was dropped into 300 ml of distilled water to remove inorganic salts by polymer coagulation. The rubber-like substance obtained by coagulation was dried under reduced pressure at 50 ° C. for 12 hours to obtain 18.0 g of a light brown rubber-like substance. The obtained light brown rubber-like substance was subjected to ¹ H-NMR measurement and elemental analysis. As a result, the repeating unit of the polyether compound E having a 1-methylpyrrolidinium halide group obtained in Production Example 5 as a starting material was used. All of the chloride ion of the 1-methylpyrrolidinium chloride group and the bromide ion of the 1-methylpyrrolidinium bromide group at the polymerization initiation terminal were exchanged for the bis (trifluoromethanesulfonyl) imide anion. It was identified as a pyrrolidinium structure-containing polyether compound F having a (trifluoromethanesulfonyl) imide anion. The number average molecular weight (Mn) of the obtained polyether compound F was 45,100.

[Example 1]
Imidazolium structure-containing polyether compound C having 5 parts of lithium bis (trifluoromethanesulfonyl) imide (LiN (SO ₂ CF ₃ ) ₂ ) and a bis (trifluoromethanesulfonyl) imide anion as a counter anion obtained in Production Example 3 By dissolving and mixing 100 parts in acetone, a transparent solution of the ion conductive composition was obtained. After applying the solution of the obtained ion conductive composition to a glass plate in a dry nitrogen atmosphere, acetone is sufficiently dried to obtain an ion conductive film having a thickness of 200 μm in a size of 30 mm × 30 mm. It was. And about the glass plate in which the ion conductive film was formed, when the shape retainability test was done according to the said method, it was confirmed that it can be evaluated that "there is shape retainability". Further, when the ion conductive membrane after 24 hours was immersed in acetone, it was also confirmed that it was dissolved well in acetone.

[Example 2]
Except that the amount of lithium bis (trifluoromethanesulfonyl) imide (LiN (SO ₂ CF ₃ ) ₂ ) was changed from 5 parts to 10 parts, in the same manner as in Example 1, the solution and ions of the ion conductive composition A conductive film was obtained. Using the obtained ion conductive membrane, a shape retention test was conducted according to the above method, and it was confirmed that it was possible to evaluate “with shape retention”. Further, when the ion conductive membrane after 24 hours was immersed in acetone, it was also confirmed that it was dissolved well in acetone.

Example 3
Except that the amount of lithium bis (trifluoromethanesulfonyl) imide (LiN (SO ₂ CF ₃ ) ₂ ) was changed from 5 parts to 20 parts, in the same manner as in Example 1, the solution and ions of the ion conductive composition A conductive film was obtained. Using the obtained ion conductive membrane, a shape retention test was conducted according to the above method, and it was confirmed that it was possible to evaluate “with shape retention”. Further, when the ion conductive membrane after 24 hours was immersed in acetone, it was also confirmed that it was dissolved well in acetone.

Example 4
Except that the amount of lithium bis (trifluoromethanesulfonyl) imide (LiN (SO ₂ CF ₃ ) ₂ ) was changed from 5 parts to 50 parts, the solution and ion of the ion conductive composition were the same as in Example 1. A conductive film was obtained. Using the obtained ion conductive membrane, a shape retention test was conducted according to the above method, and it was confirmed that it was possible to evaluate “with shape retention”. Further, when the ion conductive membrane after 24 hours was immersed in acetone, it was also confirmed that it was dissolved well in acetone.

Example 5
Except that the blending amount of lithium bis (trifluoromethanesulfonyl) imide (LiN (SO ₂ CF ₃ ) ₂ ) was changed from 5 parts to 80 parts, the solution and ion of the ion conductive composition were the same as in Example 1. A conductive film was obtained. Using the obtained ion conductive membrane, a shape retention test was conducted according to the above method, and it was confirmed that it was possible to evaluate “with shape retention”. Further, when the ion conductive membrane after 24 hours was immersed in acetone, it was also confirmed that it was dissolved well in acetone.

Example 6
In the same manner as in Example 1, except that 5 parts of lithium hexafluorophosphate (LiPF ₆ ) was used instead of 5 parts of lithium bis (trifluoromethanesulfonyl) imide (LiN (SO ₂ CF ₃ ) ₂ ) A solution of the conductive composition and an ion conductive membrane were obtained. Using the obtained ion conductive membrane, a shape retention test was conducted according to the above method, and it was confirmed that it was possible to evaluate “with shape retention”. Further, when the ion conductive membrane after 24 hours was immersed in acetone, it was also confirmed that it was dissolved well in acetone.

Example 7
Except for changing the amount of lithium hexafluorophosphate (LiPF ₆₎ in 20 parts of 5 parts, the same procedure as in Example 6 to give a solution and the ion conductive membrane of the ion conductive composition. Using the obtained ion conductive membrane, a shape retention test was conducted according to the above method, and it was confirmed that it was possible to evaluate “with shape retention”. Further, when the ion conductive membrane after 24 hours was immersed in acetone, it was also confirmed that it was dissolved well in acetone.

Example 8
Except for changing the amount of lithium hexafluorophosphate (LiPF ₆₎ in 80 parts of 5 parts, the same procedure as in Example 6 to give a solution and the ion conductive membrane of the ion conductive composition. Using the obtained ion conductive membrane, a shape retention test was conducted according to the above method, and it was confirmed that it was possible to evaluate “with shape retention”. Further, when the ion conductive membrane after 24 hours was immersed in acetone, it was also confirmed that it was dissolved well in acetone.

Example 9
Ion conduction was conducted in the same manner as in Example 1 except that 5 parts of lithium tetrafluoroborate (LiBF ₄ ) was used instead of 5 parts of lithium bis (trifluoromethanesulfonyl) imide (LiN (SO ₂ CF ₃ ) ₂ ). Solution of an ionic composition and an ion conductive membrane were obtained. Using the obtained ion conductive membrane, a shape retention test was conducted according to the above method, and it was confirmed that it was possible to evaluate “with shape retention”. Further, when the ion conductive membrane after 24 hours was immersed in acetone, it was also confirmed that it was dissolved well in acetone.

Example 10
Instead of 100 parts of the imidazolium structure-containing polyether compound C having a bis (trifluoromethanesulfonyl) imide anion as a counter anion obtained in Production Example 3, a hexafluorophosphate anion was used as the counter anion obtained in Production Example 4. A solution of an ion conductive composition and an ion conductive membrane were obtained in the same manner as in Example 4 except that 100 parts of the imidazolium structure-containing polyether compound D was used. Using the obtained ion conductive membrane, a shape retention test was conducted according to the above method, and it was confirmed that it was possible to evaluate “with shape retention”. Further, when the ion conductive membrane after 24 hours was immersed in acetone, it was also confirmed that it was dissolved well in acetone.

Example 11
Instead of 100 parts of imidazolium structure-containing polyether compound C having a bis (trifluoromethanesulfonyl) imide anion as a counter anion obtained in Production Example 3, bis (trifluoromethanesulfonyl) as a counter anion obtained in Production Example 6 Except for using 100 parts of a pyrrolidinium structure-containing polyether compound F having an imide anion, a solution of an ion conductive composition and an ion conductive film were obtained in the same manner as in Example 4. Using the obtained ion conductive membrane, a shape retention test was conducted according to the above method, and it was confirmed that it was possible to evaluate “with shape retention”. Further, when the ion conductive membrane after 24 hours was immersed in acetone, it was also confirmed that it was dissolved well in acetone.

[Comparative Example 1]
A solution of the composition and a film molded body were obtained in the same manner as in Example 1 except that lithium bis (trifluoromethanesulfonyl) imide (LiN (SO ₂ CF ₃ ) ₂ ) was not blended. When the shape retention test was performed according to the above method using the obtained film molded body, the film molded body flowed by its own weight after 24 hours, and the thickness uniformity was lost. As a result, it was judged as “no shape retention”. Moreover, when the film-molded body after the lapse of 24 hours was immersed in acetone, it was also confirmed that it was well dissolved in acetone.

  Table 1 summarizes the results of Examples 1 to 11 and Comparative Example 1.

As shown in Table 1, an ion conductive membrane obtained using an ion conductive composition containing an alkali metal salt in a proportion of 3 parts by weight or more with respect to 100 parts by weight of a polyether compound having a cationic group, Was excellent in shape-retaining property, and was well dissolved in acetone and also excellent in re-solubility (Examples 1 to 11).
On the other hand, when the alkali metal salt was not contained, the obtained film molded body did not have shape retention (Comparative Example 1).

Claims (4)

  An ion conductive composition containing an alkali metal salt in a proportion of 3 parts by weight or more with respect to 100 parts by weight of a polyether compound having a cationic group. The ion conductive composition according to claim 1, wherein the polyether compound having a cationic group comprises a monomer unit represented by the following general formula (1).

(In the above general formula (1), A ⁺ represents a cationic group or a cationic group-containing group, X ⁻ represents an arbitrary counter anion, R represents a nonionic group, and n represents 1 or more. (It is an integer, and m is an integer of 0 or more.) _3. The ion conduction according to claim 1, wherein the alkali metal salt is at least one selected from LiBF ₄ , LiPF ₆ , LiClO ₄ , LiN (SO ₂ F) ₂ , and LiN (SO ₂ CF ₃ ) _2. Sex composition.   The ion conductive film which consists of an ion conductive composition in any one of Claims 1-3.