JP2005174800A - Solid polymer electrolyte, manufacturing method of the same, and fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid polymer electrolyte having both high density of cross-linking and high conductivity, a manufacturing method of the same, and a fuel cell using such a solid polymer electrolyte. <P>SOLUTION: The solid polymer electrolyte is obtained by making a compound containing at least one reactive functional group A and one reactive functional group B react with either a first monomer having a molecular weight of 10,000 or less, containing n pieces (n≥2) of the reactive functional group A and/or the reactive functional group B, or a second monomer having a molecular weight of 10,000 or less, containing m pieces (m≥3, m≠n) of the above reactive functional group A and/or reactive functional group B. In this case, it is preferable that either one or more kinds of the first monomer or one or more kinds of the second monomer contain at least two reactive functional groups A and at least two reactive functional groups B. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a solid polymer electrolyte, a method for producing the same, and a fuel cell, and more particularly, a fuel cell, a water electrolysis device, a hydrohalic acid electrolysis device, a salt electrolysis device, an oxygen and / or hydrogen concentrator, and a humidity sensor. The present invention relates to an electrolyte membrane used in various electrochemical devices such as a gas sensor, a solid polymer electrolyte suitable for an electrolyte in a catalyst layer, a manufacturing method thereof, and a fuel cell using such a polymer electrolyte.

  The solid polymer electrolyte is a solid polymer material having an electrolyte group such as a sulfonic acid group in a polymer chain. Since the solid polymer electrolyte has a property of binding firmly to specific ions or selectively permeating cations or anions, it is formed into particles, fibers, or membranes, electrodialysis, It is used for various applications such as diffusion dialysis and battery diaphragm.

  For example, in various electrochemical devices such as solid polymer fuel cells and water electrolysis devices, the solid polymer electrolyte is used in the form of a membrane electrode assembly (MEA) in which a membrane is formed and electrodes are bonded to both sides thereof. Is done. In the polymer electrolyte fuel cell, the electrode generally has a two-layer structure of a diffusion layer and a catalyst layer. The diffusion layer is for supplying reaction gas and electrons to the catalyst layer, and carbon fiber, carbon paper, or the like is used. The catalyst layer is a part that becomes a reaction field for electrode reaction, and is generally composed of a composite of an electrode catalyst and a solid polymer electrolyte.

  As solid polymer electrolytes used in such various electrochemical devices, various fluorine-based electrolytes represented by DuPont Nafion (registered trademark) and various hydrocarbon-based electrolytes are known. The performance of the electrochemical device depends on the performance of the solid polymer electrolyte used for the electrochemical device. Generally, the higher the electrical conductivity of the solid polymer electrolyte, the higher the performance of the electrochemical device.

  In order to increase the electrical conductivity of the solid polymer electrolyte, a method of increasing the amount of acidic groups (for example, sulfonic acid groups) inside the solid polymer electrolyte is usually used. However, generally, as the amount of acidic groups in the solid polymer electrolyte increases, the solid polymer electrolyte tends to swell with water or become more soluble in water. Therefore, in such a method, a solid polymer electrolyte excellent in durability and heat resistance cannot be obtained.

  For example, in the case of a polymer electrolyte fuel cell, the electrolyte membrane before starting is in a dry state. On the other hand, when the fuel cell is operated, the membrane is swollen by humidified water contained in the reaction gas or generated water generated by the cell reaction. Therefore, when the polymer electrolyte fuel cell is repeatedly started and stopped, the membrane repeatedly swells and contracts. As a result, the solid polymer electrolyte membrane is torn or the electrode is peeled off from the solid polymer electrolyte membrane, which causes a decrease in performance.

  In order to solve this problem, various proposals have heretofore been made. For example, Patent Document 1 describes a polymer electrolyte membrane obtained by adding hexamethylenediamine (polyfunctional basic compound) to an ethanol solution containing a polymer electrolyte and casting it. In this document, by adding a polyfunctional basic compound to the polyelectrolyte, the polyfunctional basic compound is ionically bonded to a part of the sulfonic acid group of the ionomer, and a three-dimensional network is formed. And the point by which the outflow of ionomer is suppressed by this is described.

  Patent Document 2 discloses a high heat resistance obtained by crosslinking a perfluoro-based polymer compound via a strongly acidic crosslinking group composed of a bissulfonylimide group, a sulfonylcarbonylimide group, a biscarbonylimide group, or a bissulfonylmethylene group. Functional polymer electrolytes are described. In this document, a sulfonamide sodium salt of perfluoro-1,4-disulfonylfluoridebutane is reacted with hexamethyldisilazane to synthesize a crosslinking agent, and this is reacted with Nafion (registered trademark). Describes that Nafion (registered trademark) can be cross-linked via a bissulfonylimide group and that the high-temperature creep resistance of the film is thereby improved.

Patent Document 3 discloses that a chlorinated sulfonated polyetheretherketone (PEEK-SO ₂ Cl) and NH ₂ SO ₂ (CF ₂ ) ₄ SO ₂ NH ₂ are reacted with each other so that the polymer main chain has a bismuth. It describes that a crosslinked polymer crosslinked with a sulfonylimide group is obtained. This document describes that the water absorption capability of such a crosslinked polymer is lower than that of a non-crosslinked material, and that the conductivity measured at room temperature is 0.065 S / cm.

  Furthermore, Patent Document 4 describes a method for modifying an electrolyte in which an amine compound is brought into contact with a perfluoropolymer electrolyte or a precursor thereof. In this document, when an amine compound such as ammonia or lithium bis (trimethylsilyl) amide is brought into contact with a Nafion (registered trademark) film, creep resistance can be improved while maintaining a relatively high electrical conductivity. The points that can be done are described.

JP 2002-26041 A JP 2000-188013 A JP-T-2002-516348 JP 2001-319521 A

  As described in Patent Document 1, when a polyfunctional basic compound is added to the solid polymer electrolyte, the polymer chains can be ionically cross-linked via the acidic group of the solid polymer electrolyte. However, ionic bonds are easily broken in an environment where water is present. Therefore, when this is used for a long period of time as an electrolyte membrane for a fuel cell, an electrolyte in a catalyst layer, etc., there is a possibility that ionic bonds are broken by water existing in the system and the polymer flows out.

  On the other hand, as described in Patent Documents 2 and 3, when the polymer chains of the solid polymer electrolyte are molecularly cross-linked using a predetermined cross-linking agent, all of the cross-linking points are constituted by covalent bonds. Yes. Therefore, swelling / shrinkage of the film with respect to water can be suppressed, and even when the film is used for a long time in an environment where water exists, there is little possibility that the polymer flows out. Moreover, the strength of the film is improved by the crosslinking, and heat resistance and durability are improved.

  However, the method of molecularly crosslinking a solid polymer electrolyte has a limit in the reachable crosslinking density. For example, in the case of a solid polymer electrolyte having an equivalent weight (EW) of 1000, the maximum crosslinking density is theoretically 0.5 mmol / g at the maximum.

  Furthermore, as described in Patent Document 4, in the method of cross-linking using ammonia or the like, one bissulfonylimide group is generated from two sulfonic acid groups, so that the electric conductivity accompanying the increase in cross-linking density. The rate of decrease of becomes larger. Therefore, in the conventional method, it is difficult to increase both the crosslinking density and the electrical conductivity at the same time.

  The problem to be solved by the present invention is to provide a solid polymer electrolyte having both high crosslink density and high electrical conductivity, a method for producing the same, and a fuel cell using such a solid polymer electrolyte. It is in. In addition, another problem to be solved by the present invention is that the polymer does not flow out into water, and the solid polymer electrolyte is less swelled / shrinked even when used in an environment where water exists, and its production The present invention provides a method and a fuel cell using such a solid polymer electrolyte.

In order to solve the above-mentioned problems, the solid polymer electrolyte according to the present invention reacts one or more kinds of first monomers satisfying the following conditions with one or more kinds of second monomers. It consists of what is obtained by.
(1) The first monomer has a molecular weight of 10,000 or less and includes n (n ≧ 2) reactive functional groups A and / or reactive functional groups B in one molecule.
(2) The second monomer has a molecular weight of 10,000 or less and includes m (m ≧ 3, m ≠ n) of the reactive functional group A and / or the reactive functional group B in one molecule. Consists of things.
(3) The reactive functional group A and the reactive functional group B are bissulfonimide group (—SO ₂ NHSO ₂ —), sulfoncarbonimide group (—SO ₂ NHCO—), or bis by these reactions. It consists of what forms a carbonimido group (-CONHCO-).
(4) The one or more types of the first monomer and the one or more types of the second monomer may include at least one reactive functional group A and at least one It comprises the reactive functional group B.

  In this case, the one or more kinds of the first monomers and the one or more kinds of the second monomers each include at least two of the reactive functional groups A and at least two of the reactive functional groups A. Those containing the reactive functional group B are preferred. The solid polymer electrolyte impregnates a porous membrane with a solution containing one or more kinds of first monomers and one or more kinds of second monomers, and the one or more kinds of first monomers are impregnated. It may be obtained by reacting one monomer and one or more second monomers.

  In addition, the method for producing a solid polymer electrolyte according to the present invention includes one or more first monomers satisfying a predetermined condition and one or more second monomers satisfying a predetermined condition. The gist is to prepare a mixed solution and react the first monomer and the second monomer.

The second of the solid polymer electrolytes according to the present invention is obtained by reacting one or more third monomers that satisfy the following conditions.
(1) The third monomer has a molecular weight of 10,000 or less and includes p (p ≧ 3) reactive functional groups A and / or reactive functional groups B in one molecule.
(2) The reactive functional group A and the reactive functional group B are converted into a bissulfonimide group (—SO ₂ NHSO ₂ —), a sulfoncarbonimide group (—SO ₂ NHCO—), or bis by these reactions. It consists of what forms a carbonimido group (-CONHCO-).
(3) The one kind or two or more kinds of third monomers are composed of any of these containing at least one reactive functional group A and at least one reactive functional group B. .

  In this case, the third monomer is two or more types of monomers including a total of three reactive functional groups A and / or reactive functional groups B in one molecule, Those containing two reactive functional groups A and at least two reactive functional groups B are preferred. The third monomer is one or two or more monomers including a total of four or more of the reactive functional groups A and / or the reactive functional groups B in one molecule. In addition, those containing at least two of the reactive functional groups A and at least two of the reactive functional groups B are preferable. Furthermore, the solid polymer electrolyte may be obtained by impregnating a porous membrane with a solution containing one or more third monomers and reacting the one or more third monomers. good.

  Furthermore, the second method for producing a solid polymer electrolyte according to the present invention is to prepare a mixed liquid containing one or more third monomers satisfying a predetermined condition, and react the third monomers. The gist.

  When one or more monomers satisfying a predetermined condition are reacted, a reactive functional group A contained in one monomer reacts with a reactive functional group B contained in another monomer, Acid groups such as bissulfonylimide groups are formed. Therefore, as the polymerization proceeds, acidic groups increase, and a solid polymer electrolyte having high electrical conductivity can be obtained. Moreover, as the polymerization proceeds, physical or chemical crosslinking between the polymer chains also proceeds, so that both the electrical conductivity and the crosslinking density can be improved at the same time.

  Hereinafter, embodiments of the present invention will be described in detail. The polymer electrolyte according to the first embodiment of the present invention is obtained by reacting one or more types of first monomers that satisfy a predetermined condition with one or more types of second monomers. It is made up of.

In the present invention, the “first monomer” has a molecular weight of 10,000 or less and includes n (n ≧ 2) reactive functional groups A and / or reactive functional groups B in one molecule. .
The “second monomer” has a molecular weight of 10,000 or less and includes m (m ≧ 3, m ≠ n) reactive functional groups A and / or reactive functional groups B in one molecule. Say.
Furthermore, “reactive functional group A” and “reactive functional group B” are bissulfonimide group (—SO ₂ NHSO ₂ —), sulfonecarbonimide group (—SO ₂ NHCO—), Alternatively, it refers to a functional group capable of forming a biscarbonimide group (—CONHCO—) (hereinafter collectively referred to as “imide group”).

  The molecular weights of the first monomer and the second monomer are not particularly limited, and optimum values are selected according to the characteristics and applications required for the polymer electrolyte. Generally, as the molecular weight of the first monomer and / or the second monomer decreases, a solid polymer electrolyte having a high crosslinking density and a high electrical conductivity can be obtained. On the other hand, the higher the molecular weight of the first monomer and / or the second monomer, the more flexible the polymer electrolyte is obtained. However, if the molecular weight of the first monomer and / or the second monomer is too large, it is difficult to achieve both high crosslink density and high electrical conductivity at the same time. Therefore, it is preferable to use those having a molecular weight of 10,000 or less for the first monomer and the second monomer, respectively.

  For example, when the polymer electrolyte according to the present invention is used as an electrolyte membrane of a solid polymer fuel cell, the molecular weights of the first monomer and the second monomer are each preferably 130 or more and 10,000 or less, more preferably 130 or more and 7000. It is as follows.

  For example, when the polymer electrolyte according to the present invention is used as the electrolyte in the catalyst layer of the solid polymer fuel cell, the molecular weights of the first monomer and the second monomer are preferably 130 or more and 10,000 or less, respectively, more preferably 130 to 7000.

  As a result, the reactive functional group A and the reactive functional group B contained in the first monomer and the second monomer are reacted directly, or by reacting after adding an appropriate functional group conversion. Any material that can form an imide group may be used.

There are various combinations of the reactive functional group A and the reactive functional group B. Among them, the reactive functional group A consists of —SO ₂ X or —COX (where X is F, Cl, Br, I, or OH) (hereinafter, these are referred to as “halide functional groups”), The reactive functional group B is —SO ₂ NZ ₁ Z ₂ , or —CONZ ₁ Z ₂ (where Z ₁ and Z ₂ are H, M, or SiMe ₃ , respectively, M is a metal ion) (hereinafter referred to as “metal ion”). These are referred to as “imide functional groups”) or vice versa. The metal ion M is preferably a monovalent metal ion such as Li, K, or Na.

  The combination of the halide functional group and the imide functional group is particularly suitable as a combination of the reactive functional group A and the reactive functional group B because it is often easy to directly react without adding functional group conversion. It is. In addition, even if these functional groups remain unreacted, they can be converted into sulfonic acid groups or carboxylic acid groups by performing an appropriate treatment, so that a solid polymer electrolyte having high electrical conductivity is obtained. Is obtained.

Among the halide functional groups, those in which X is F, Cl, Br or I have high reactivity, and therefore are suitable as the reactive functional group A or the reactive functional group B. Furthermore, among the imide-based functional groups, the combination of (Z ₁ , Z ₂ ) is composed of (H, H), (H, M), (SiMe ₃ , M), or (H, SiMe ₃ ) Is suitable as the reactive functional group A or the reactive functional group B because it has high reactivity.

  The total number n of the reactive functional group A and the reactive functional group B contained in one molecule of the first monomer may be two or more. On the other hand, the total number m of reactive functional groups A and reactive functional groups B contained in one molecule of the second monomer is 3 or more, and is different from the total number n of functional groups in the first monomer. (M ≠ n) may be sufficient.

In addition, the first monomer may include only one of the reactive functional group A and the reactive functional group B, or may include both. When the first monomer contains two or more reactive functional groups A (or reactive functional groups B), these reactive functional groups A (or reactive functional groups B) are of the same type. It may be a functional group (for example, only —SO ₂ X), or may be a different type of functional group (for example, a combination of —SO ₂ X and —COX). This also applies to the second monomer.

  As such a first monomer and a second monomer, there are various monomers. Among them, the monomer (1) to monomer (8) shown in the following chemical formula 5 and the monomer (9) to monomer (18) shown in chemical formula 6 are suitable as the first monomer. Moreover, the monomer (5) to the monomer (8) shown in the chemical formula 5 and the monomer (15) to the monomer (18) shown in the chemical formula 6 are suitable as the second monomer. Further, among these monomers, those that do not contain a C—H bond in the molecule, the polymer chain becomes a perfluoro skeleton, and a solid polymer electrolyte excellent in heat resistance and oxidation resistance can be obtained. Is preferred.

Note that, in the formula (6), “a combination other than Y ₁ = Y ₂ = Y ₃ ” means that Y ₁ = Y ₂ ≠ Y ₃ , Y ₁ = Y ₃ ≠ Y ₂ , Y ₁ This is the case where ≠ Y ₂ = Y ₃ , the case where Y ₁ ≠ Y ₂ ≠ Y ₃ , or the like. Further, “a combination other than P ₁ = P ₂ = P ₃ = P ₄ ” means that P ₁ = P ₂ = P ₃ ≠ P ₄ or P ₁ = P ₂ = P ₄ ≠ P _3. P ₁ = P ₃ = P ₄ ≠ P ₂ , P ₁ ≠ P ₂ = P ₃ = P ₄ , P ₁ = P ₂ ≠ P ₃ ≠ P ₄ , P ₁ = P ₃ ≠ P ₂ ≠ P ₄ , P ₁ = P ₄ ≠ P ₂ ≠ P ₃ , P ₁ ≠ P ₂ ≠ P ₃ = P ₄ , P ₁ ≠ P ₂ ≠ P ₃ ≠ refers to such case is a P _4. In the monomer (17) represented by the formula (6), when _B in the central repeating unit “— (CF ₂ CFP ₂ ) _B —” is 2 or more, each functional group P ₂ is The same functional group may be used, or a combination of different functional groups may be used.

  Other examples of the first monomer and the second monomer include a Nafion monomer and a molecular weight composed of 2 to 15 compounds selected from monomers (A) to (F) represented by the following formula 7 As an appropriate example, oligomers of these or derivatives thereof are mentioned.

  In the case of synthesizing the solid polymer electrolyte according to the present invention using one or two or more kinds of first monomers and one or two or more kinds of second monomers, one or more kinds of first monomers are synthesized. The monomer and one or more second monomers need to include at least one reactive functional group A and at least one reactive functional group B in any of them. Further, in order to introduce chemical cross-linking into the solid polymer electrolyte, one or more of the first monomers and one or more of the second monomers may be at least 2 Those containing one reactive functional group A and at least two reactive functional groups B are preferred.

  For example, as the first monomer, a bifunctional monomer having two imide-based functional groups (A) (for example, the monomer (1) or (2) shown in the formula 5). Hereinafter, this is abbreviated as “AA”. ) And a trifunctional monomer having two imide-based functional groups (A) and one halide-based functional group (B) (for example, a monomer (15) represented by the formula 6). In the following, when these are reacted, the trifunctional monomer AAB is bonded to both ends of the bifunctional monomer AA, and the oligomer having the structure of “AAB-AA-BAA” is used. Is obtained. In this case, a total of two imide groups (“BA” and “AB”) are formed at the bonding points of the bifunctional monomer AA and the trifunctional monomer AAB.

  When the reaction is further continued, the halide functional group (B) of the trifunctional monomer AAB is bonded to any of the imide functional groups (A) at the end of the oligomer, and a new imide group is added to the bonding point. (AB) is formed. Hereinafter, by sequentially repeating such a reaction, a so-called “dendrimer” in which polymer chains grow radially centering on the bifunctional monomer AA can be formed.

  Further, for example, as the first monomer, a bifunctional monomer having one imide functional group (A) and one halide functional group (B) (for example, a monomer (9) represented by the formula 6), (10), (12), or (14) (hereinafter abbreviated as “AB”), and a trifunctional monomer having three halide functional groups (B) as the second monomer (for example, In the case of using the monomer (5) represented by the formula of Chemical formula 5. (hereinafter abbreviated as “BBB”), the structure “BA-BB (AB) B-AB” is obtained by reacting them. The oligomer having is obtained.

  When the reaction is further continued, the imide functional group (A) of the bifunctional monomer AB is bonded to any halide functional group (B) at the end of the oligomer, and a new imide group is added to the bonding point. (AB) is formed. Hereinafter, by sequentially repeating such a reaction, a so-called “dendrimer” in which polymer chains are radially grown around the trifunctional monomer BBB can be formed.

  Also, for example, a bifunctional monomer AA having two imide functional groups (A) is used as the first monomer, and a trifunctional monomer BBB having three halide functional groups (B) is used as the second monomer. When used, when these are reacted, an oligomer having the structure “AA-BB (AA) B-AA” is obtained.

  When the reaction is further continued, the trifunctional monomer BBB and the bifunctional monomer AA are bonded in this order to any of the imide-based functional groups (A) at the end of the oligomer. An imide group (AB) is formed. Hereinafter, by sequentially repeating such a reaction, a so-called “crosslinked network type” solid polymer electrolyte in which the grown polymer chains are mutually crosslinked via the bifunctional monomer AA is obtained.

  Further, for example, a bifunctional monomer AA having two imide functional groups (A) is used as the first monomer, and one imide functional group (A) and two halide functional groups are used as the second monomer. When a trifunctional monomer BAB having a group (B) (for example, the monomer (15) shown in the formula 6) is reacted, an oligomer having a structure of “AA-BAB-AA” is obtained. .

  When the reaction is further continued, the halide functional group (B) of the trifunctional monomer BAB is newly bonded to any imide-based functional group (A) at the end or center of the oligomer. An imide group (AB) is newly formed. Furthermore, a new trifunctional monomer BAB or an imide functional group (A) of a bifunctional monomer AA is further bonded to the halide functional group (B) remaining at the end of the oligomer, An imide group (A-B) is formed. Hereinafter, by sequentially repeating such a reaction, a so-called “crosslinked network type” solid polymer electrolyte in which the grown polymer chains are mutually crosslinked via the bifunctional monomer AA is obtained.

  For example, a bifunctional monomer AB having one imide functional group (A) and one halide functional group (B) is used as the first monomer, and one imide functional is used as the second monomer. When a trifunctional monomer BAB having a group (A) and two halide functional groups (B) is used, an oligomer having a structure of “BA-BAB-AB” is obtained by reacting them.

  When the reaction is further continued, the imide functional group (A) of the bifunctional monomer AB or the trifunctional monomer BAB is bonded to any halide functional group (B) at the end of the oligomer, and is bonded to the bonding point. Forms a new imide group (AB). In addition, a halide functional group (B) of a bifunctional monomer AB or a trifunctional monomer BAB is bonded to any imide functional group (A) at the end of the oligomer, and a new imide is bonded to the bonding point. A group (AB) is formed. Hereinafter, by sequentially repeating such a reaction, a so-called “crosslinked network type” solid polymer electrolyte in which the grown polymer chains are mutually crosslinked by the bifunctional monomer AB is obtained.

  For example, a bifunctional monomer AB having one imide functional group (A) and one halide functional group (B) is used as the first monomer, and three imide functional groups are used as the second monomer. When a trifunctional monomer AAA having a group (A) (for example, a monomer (5) represented by the formula 5) and a trifunctional monomer BBB having three halide functional groups are used, The trifunctional monomer AAA and the bifunctional monomer AB react to obtain an oligomer having a structure of “AB-AA (BA) A-BA”.

  When the reaction is further continued, the trifunctional monomer BBB or the bifunctional monomer BA is first bonded to any imide-based functional group (A) at the end of the oligomer. A group (AB) is formed. Next, the trifunctional monomer AAA or the bifunctional monomer AB is further bonded to the halide functional group (B) at the end, and the trifunctional monomer BBB or 2 is further bonded to the imide functional group (A). The functional monomer BA is bonded, and an imide group (AB) is newly formed at each bonding point. Hereinafter, by sequentially repeating such a reaction, a so-called “crosslinked network type” solid polymer electrolyte in which the grown polymer chains are crosslinked with each other can be obtained.

  Further, for example, a bifunctional monomer AA having two imide functional groups (A) and a bifunctional monomer BB having two halide functional groups (B) are used as the first monomer, and the second monomer is When trifunctional monomer BBB having three halide functional groups (B) is used, when these are reacted, first, trifunctional monomer BBB and bifunctional monomer AA react, and “AA-BB (AA) B” An oligomer having the structure -AA "is obtained.

  When the reaction is further continued, the trifunctional monomer BBB or the bifunctional monomer BB is first bonded to any imide-based functional group (A) at the end of the oligomer, and each of the bonding points has a new imide. A group (AB) is formed. Next, the bifunctional monomer AA is further bonded to the halide functional group (B) at the end, and an imide group (AB) is newly formed at each bonding point. Hereinafter, by sequentially repeating such a reaction, a so-called “crosslinked network type” solid polymer electrolyte in which the grown polymer chains are crosslinked with each other can be obtained.

  The same applies when synthesizing using a monomer having four or more reactive functional groups. At least one reactive functional group A and at least one reaction are added to any of a plurality of different types of monomers. When the functional group B is included, a dendrimer having polymer chains grown radially can be obtained. In addition, when any of a plurality of different types of monomers includes at least two reactive functional groups A and at least two reactive functional groups B, the polymer chains are cross-linked with each other. A crosslinked network type solid polymer electrolyte is obtained.

  The mixing ratio of one or more kinds of first monomers and one or more kinds of second monomers is selected in accordance with the form, application, required characteristics, etc. of the synthesized solid polymer electrolyte. . For example, when synthesizing a dendrimer, it is preferable to relatively increase the ratio of the monomer constituting the polymer chain to the monomer serving as the nucleus of the dendrimer.

  In general, the molecular weight of dendrimers can be increased as the proportion of monomers constituting the polymer chain increases. However, if the ratio of monomers constituting the polymer chain is too large, a high molecular weight electrolyte cannot be obtained (molecular weight does not increase), which is not preferable. Specifically, the ratio of the monomer constituting the polymer chain is preferably 10 mol or more and 700 mol or less, more preferably 30 mol or more and 300 mol or less, with respect to 1 mol of the monomer serving as the core of the dendrimer. These dendrimers can also be made into a crosslinked network type by, for example, further reacting a reactive functional group A with a reactive functional group A and a reactive functional group B with each other.

  On the other hand, when the crosslinked network type solid polymer electrolyte is synthesized, the number of moles of the reactive functional group A contained in the first monomer and the second monomer is equal to the number of moles of the reactive functional group B. When the first monomer and the second monomer are blended, an imide group can be generated from all the reactive functional groups A and B.

  However, the number of moles of the reactive functional group A and the reactive functional group B contained in the first monomer and the second monomer need not be the same, and either one may be excessive or insufficient. Even if either one is excessive or insufficient, unreacted reactive functional group A or reactive functional group B remains in the polymer chain as it is, or around the polymer crosslinked in a network form. This is because it is considered that linear or branched polymer chains only grow radially.

  However, when the ratio of the reactive functional group A and the reactive functional group B is greatly deviated from the theoretical value, unreacted monomers or low molecular weight oligomers remain in the solid polymer electrolyte, and these monomers or oligomers remain in use. Is not preferred because it may be eluted. Therefore, when synthesizing a crosslinked network type solid polymer electrolyte, it is preferable to follow the so-called gelation theory.

If α is the probability that a branching unit will bind to the next branched monomer via a bifunctional monomer, (1-α) is the probability that a chain from the branch will not extend further through the branch. . Therefore, if the branching point is trifunctional, α> 1/2, and if the branching point is f-functional, the molecule continues indefinitely if α> 1 / (f−1). If α is α ₀ at the gelation point where an infinite network has just begun,
α ₀ = 1 / (f−1)
It is. One is a mixture of f-functional and bifunctional monomers, and the other is only a bifunctional monomer. For example, if f = 3, the following chain branched at both ends by the reaction of AAA, AA, and BB,

However, consider the relationship between the generation probability and the monomer reaction rate. The initial concentration of A [A] Let ρ be the fraction of those belonging to the f-functional monomer in ₀ . At the stage where the reaction rates of the functional groups of A and B are p _A and p _B , the probability of forming a chain in which both ends are bonded to the f-functional monomer is as follows:
p _A {p _B (1-ρ) p _A } ⁿ p _B ρ (n = 0 to ∞)
Therefore, the probability that both ends of any chain are connected to the branching point regardless of n, that is, α is

become. When the functional group concentration ratio of A and B at the beginning of the reaction system is γ, p _B = γp _A , and this equation is put into the above equation,
α = γp _A ² ρ / {1-γp _A ² (1-ρ)} = p _B ² ρ / {γ-p _B ² (1-ρ)}
Is induced. Therefore, α can be obtained by actually measuring p _A and p _{B. Since} α ₀ = 1 / (f−1) at the gel point, if γ and ρ are known, the gel point p _A or p _B can be predicted. (See Polymer Science Society, “Basics of Polymer Science”, p. 250-251, Tokyo Kagaku Dojin (1978).)

  For example, in the case of the combination of the trifunctional monomer AAA and the bifunctional monomer BB, assuming that the reaction rate is 1, the ratio of the reactive functional group B to 1 mole of the reactive functional group A is 0.5 mole. The first monomer and the second monomer are preferably blended so as to be 2 mol or less. The ratio of the reactive functional group B to 1 mol of the reactive functional group A is more preferably 0.8 mol or more and 1.2 mol or less.

  Further, in the case of the tetrafunctional monomer AAAA and the bifunctional monomer BB, assuming that the reaction rate is 1, the ratio of the reactive functional group B to 1 mole of the reactive functional group A is 0.3 mol or more 3 The first monomer and the second monomer are preferably blended so as to be less than or equal to a mole. The ratio of the reactive functional group B to 1 mol of the reactive functional group A is more preferably 0.6 mol or more and 1.5 mol or less.

  The solid polymer electrolyte according to the present embodiment may be composed only of the polymer synthesized from the first monomer and the second monomer described above, or may be a porous film, a fibril fiber, or the like as a reinforcing material. It may be a composite.

  When the solid polymer electrolyte according to the present embodiment and the porous membrane are combined, the porous membrane is made of polytetrafluoroethylene, polyimide, polyethylene, polyethylene tetrafluoroethylene, PFA (tetrafluoroethylene perfluorovinyl ether copolymer). It is preferable to use those composed of FEP (tetrafluoroethylene hexafluoropropylene copolymer), porous silica, porous ceramics and the like. In this case, the porosity, average pore diameter, thickness, and the like of the porous membrane are selected as optimum values according to the use of the solid polymer electrolyte membrane, required characteristics, and the like. The solid polymer electrolyte may be uniformly dispersed in the porous film, or may be unevenly distributed on the surface or inside of the porous film.

  Furthermore, in the solid polymer electrolyte according to the present embodiment, a cross-linked structure is introduced into the interior thereof according to the synthesis conditions such as the types and blending ratios of the first monomer and the second monomer used for synthesis. Here, in the present invention, “crosslinking” means “physical crosslinking” formed by physical entanglement of polymer chains, and “chemistry” in which the polymer chains are molecularly crosslinked by the first monomer or the second monomer. It means both “cross-linking”.

  The crosslink density can be prepared by optimizing the synthesis conditions. In general, the higher the crosslinking density, the less the swelling / shrinkage with respect to water, and the solid polymer electrolyte excellent in heat resistance and durability can be obtained. Specifically, the crosslinking density is preferably 0.1 mmol / g or more, and more preferably 0.5 mmol / g or more.

  In the solid polymer electrolyte according to the present embodiment, the cross-linking point functions as a strong acid group as it is, so that the electrical conductivity increases as the cross-linking density increases. That is, it is possible to simultaneously achieve a high crosslink density and a high electrical conductivity, which are difficult with the conventional method. The electrical conductivity can be adjusted by optimizing the synthesis conditions. In order to obtain an electrochemical device having high performance, specifically, the electrical conductivity of the solid polymer electrolyte is preferably 0.01 S / cm or more, and more preferably 0.05 S / cm or more.

  Next, the manufacturing method of the solid polymer electrolyte which concerns on this Embodiment is demonstrated. The solid polymer electrolyte according to the present embodiment is prepared by preparing a mixed solution containing one or more kinds of first monomers and one or more kinds of second monomers, and the first monomer and the second monomer. Can be synthesized by reacting with.

  In this case, the first monomer and the second monomer may be reacted as they are, or may be reacted after appropriate functional group conversion. The first monomer and the second monomer are preferably dissolved in a solvent that can dissolve both. The solvent is not particularly limited as long as an optimum solvent is selected according to the types of the first monomer and the second monomer. Further, the concentrations of the first monomer and the second monomer contained in the solution are not particularly limited, and an optimal one may be selected according to the types of the first monomer and the second monomer.

  Further, when the first monomer and the second monomer are reacted, a reagent for increasing the reaction rate of the reactive functional group A and the reactive functional group B (that is, having a catalytic action) may be added thereto. As such a reagent, specifically, basic compounds such as triethylamine, trimethylamine, tripropylamine, tributylamine, DBU (diazabicycloundecene) are suitable. The amount of the reagent having a catalytic action is selected in accordance with the use of the solid polymer electrolyte, required characteristics, and the like. By optimizing the amount of reagent, the viscosity of the mixture can be adjusted.

  Next, the mixed solution thus prepared is poured into a suitable container. For example, when a membrane electrolyte is produced, a small amount of a mixed solution is poured into a shallow container to form a membrane, and the reaction may be performed in this state. At this time, the film thickness can be adjusted by adjusting the amount of the mixed solution to be poured. Further, for example, when producing a massive electrolyte, a large amount of the mixed solution may be poured into a deep container and allowed to react as it is.

  Also, when preparing a composite electrolyte membrane reinforced with a porous membrane, place the porous membrane on the bottom of a shallow container, pour a small amount of mixed liquid from above, and impregnate the mixed liquid inside the porous membrane. good. Moreover, when the reagent which has a catalytic action is contained in the liquid mixture, reaction may already advance to some extent inside the liquid mixture, and the viscosity of the liquid mixture may increase. When a composite electrolyte membrane is produced using such a mixed solution, a small amount of the mixed solution is poured from above the porous membrane, and then pressure is applied to press the mixed solution into the porous membrane. At this time, by adjusting the viscosity and / or pressure of the mixed liquid, it is possible to uniformly fill the porous film with the mixed liquid or to partially fill the mixed liquid.

The reaction of the first monomer and the second monomer is preferably performed in an inert atmosphere such as Ar or N _{2 in} order to prevent alteration such as hydrolysis of the first monomer and the second monomer. The reaction temperature, reaction time, and pressure during the reaction are not particularly limited, depending on the type of the first monomer and the second monomer, the concentration of the mixed solution, the type and amount of the reagent having a catalytic action, and the like. Select the optimum value.

  When the reaction is completed, the resulting polymer is removed from the container, and the crosslinking points and unreacted reactive functional groups A and B are converted into acidic groups. Various methods can be used as a method for converting to an acidic group, and the method is not particularly limited. Specifically, a method in which the synthesized polymer is protonated by treatment with an acid such as nitric acid, and a method in which the synthesized polymer is saponified with an alkaline solution and then treated with an acid to be protonated are suitable. is there.

  Next, a solid polymer electrolyte according to a second embodiment of the present invention will be described. The solid polymer electrolyte according to the present embodiment is obtained by reacting one kind or two or more kinds of third monomers.

  In the present embodiment, the “third monomer” has a molecular weight of 10,000 or less and includes p (p ≧ 3) reactive functional groups A and / or reactive functional groups B in one molecule. say. That is, the present embodiment is characterized in that one or two or more third monomers having the same number of functional groups per molecule are used as starting materials.

  Note that the molecular weight of the third monomer and the types and combinations of the reactive functional group A and the reactive functional group B contained in the third monomer are the same as those of the first monomer and the second monomer described above. Omitted.

The total number of reactive functional groups A and reactive functional groups B contained in one molecule of the third monomer may be p (p ≧ 3). In addition, the third monomer may include only one of the reactive functional group A and the reactive functional group B, or may include both. Further, when the third monomer contains two or more reactive functional groups A (or reactive functional groups B), these reactive functional groups A (or reactive functional groups B) are of the same type. It may be a functional group (for example, only —SO ₂ X), or may be a different type of functional group (for example, a combination of —SO ₂ X and —COX).

  As such a third monomer, there are various monomers. Among these, the monomer (5) to the monomer (8) shown in the chemical formula 9 and the monomer (15) to the monomer (18) shown in the chemical formula 10 are suitable as the third monomer. Further, among these monomers, those that do not contain a C—H bond in the molecule, the polymer chain becomes a perfluoro skeleton, and a solid polymer electrolyte excellent in heat resistance and oxidation resistance can be obtained. Is preferred.

  As the third monomer other than this, for example, an oligomer having a molecular weight of 10,000 or less consisting of 3 to 15 compounds selected from Nafion monomer and monomers (A) to (F) represented by the following formula 11 These derivatives are mentioned as a suitable example.

  In the case of synthesizing the solid polymer electrolyte according to the present invention using such one or more third monomers, one or more of the third monomers is at least 1 in any of these. It is necessary to include one reactive functional group A and at least one reactive functional group B.

  Further, when chemical cross-linking is introduced into the solid polymer electrolyte, when a third monomer having three reactive functional groups in one molecule is used, there are two or more third monomers. In any of these, it is preferable to use those containing at least two reactive functional groups A and at least two reactive functional groups B. Moreover, when using what has a 4 or more reactive functional group in 1 molecule as a 3rd monomer, it is 1 type (s) or 2 or more types of 3rd monomer, Comprising: At least 2 in these either It is preferable to use those containing a reactive functional group A and at least two reactive functional groups B.

  For example, when a trifunctional monomer AAB having two imide functional groups (A) and one halide functional group (B) is used as the third monomer, when this is reacted, one trifunctional monomer is obtained. The imide functional group (A) of another trifunctional monomer AAB is bonded to the halide functional group (B) of AAB, and an oligomer having a structure of “AAB-AAB” is obtained. In addition, one imide group (B-A) is formed at the bonding point.

  When the reaction is further continued, the halide functional group (B) of the new trifunctional monomer AAB is bonded to the imide functional group (A) at the end of the oligomer, and the halide at the end of the oligomer. The imide functional group (A) of a new trifunctional monomer AAB is bonded to the system functional group (B), and an imide group (AB) is newly formed at each bonding point. Hereinafter, by sequentially repeating such a reaction, it is possible to form a so-called “dendrimer” in which polymer chains are radially grown around the initially formed oligomer.

  For example, when a trifunctional monomer AAA having three imide functional groups (A) and a trifunctional monomer BBB having three halide functional groups (B) are used as the third monomer, Is reacted to give an oligomer having a structure of “AAA-BB (AAA) B-AAA”.

  When the reaction is further continued, the trifunctional monomer BBB is bonded to any one of the imide functional groups (A) at the end of the oligomer, and imide groups (AB) are newly added to the bonding points. It is formed. Hereinafter, by sequentially repeating such a reaction, a so-called “crosslinked network type” solid polymer electrolyte in which the grown polymer chains are crosslinked with each other can be obtained.

  In addition, for example, when a tetrafunctional monomer AAAB having three imide functional groups (A) and one halide functional group (B) is used as the third monomer, when this is reacted, one 4 The imide functional group (A) of another trifunctional monomer AAAAB is bonded to the halide functional group (B) of the functional monomer AAAAB to obtain an oligomer having a structure of “AAAB-AAAB”. In addition, one imide group (B-A) is formed at the bonding point.

  When the reaction is further continued, the halide functional group (B) of the new tetrafunctional monomer AAAB is bonded to the imide functional group (A) at the end of the oligomer, and the halide at the end of the oligomer. The imide functional group (A) of the new tetrafunctional monomer AAAB is bonded to the system functional group (B), and an imide group (AB) is newly formed at the bonding point. Hereinafter, by sequentially repeating such a reaction, it is possible to form a so-called “dendrimer” in which polymer chains are radially grown around the initially formed oligomer.

  Further, for example, when a tetrafunctional monomer AABB having two imide functional groups (A) and two halide functional groups (B) is used as the third monomer, by reacting them, “AABB” An oligomer having the structure “-AABB” is obtained.

  When the reaction is further continued, the halide functional group (B) of the new tetrafunctional monomer AABB is bonded to any imide-based functional group (A) at the end of the oligomer. The imide functional group (A) of the new tetrafunctional monomer AABB is bonded to any one of the halide functional groups (B), and a new imide group (AB) is newly added to each bonding point. It is formed. Hereinafter, by sequentially repeating such a reaction, a so-called “crosslinked network type” solid polymer electrolyte in which the grown polymer chains are crosslinked with each other can be obtained.

  The same applies to the case of synthesizing using a monomer having 5 or more reactive functional groups, and at least one reactive functional group A and at least 1 In the case of containing one reactive functional group B, a dendrimer in which polymer chains are grown radially can be obtained. In addition, in the case where at least two reactive functional groups A and at least two reactive functional groups B are included in either one or two or more third monomers, the polymer chains are mutually A crosslinked network type solid polymer electrolyte is obtained.

  In addition, in the case of synthesizing using two or more kinds of third monomers, it is preferable to select an optimal ratio as appropriate, and a suitable mixing ratio for forming a dendrimer, and a crosslinked network The suitable blending ratio for forming the solid polymer electrolyte of the type is the same as that in the first embodiment, and thus the description thereof is omitted.

  In addition, the solid polymer electrolyte according to the present embodiment may be synthesized only from the third monomer, or may be a composite with a porous film, etc. Since the point regarding conductivity is the same as that of the first embodiment, the description thereof is omitted.

  Next, the manufacturing method of the solid polymer electrolyte which concerns on this Embodiment is demonstrated. The solid polymer electrolyte according to the present embodiment can be synthesized by preparing a mixed liquid containing one or more third monomers and reacting the third monomers. The manufacturing method according to the present embodiment is the same as that of the first embodiment except that one or more types of third monomers are used as the starting material, and thus the description thereof is omitted.

  Next, the operation of the solid polymer electrolyte according to the present invention will be described. When one or more monomers having a reactive functional group A and / or a reactive functional group B in one molecule and satisfying a predetermined condition are reacted, the two monomers are reacted with the reactive functional group A and Bonding via the reactive functional group B, an imide group that functions as a strong acid group is formed at the bonding point. Therefore, as the polymerization proceeds, acidic groups increase, and a solid polymer electrolyte having high electrical conductivity can be obtained.

  As the polymerization proceeds, physical or chemical crosslinks are also formed between the polymer chains. Therefore, a high crosslinking density can be easily obtained as compared with the conventional method of crosslinking a polymer chain using a polymer electrolyte as a starting material. Furthermore, it is possible to simultaneously improve both the electrical conductivity and the crosslinking density, which is difficult with the conventional method, and a solid polymer electrolyte excellent in heat resistance and durability can be obtained.

  Further, when the solid polymer electrolyte according to the present invention is used as an electrolyte membrane for a fuel cell, the outflow of the polymer is suppressed because a physical or chemical crosslink is formed in the membrane. Moreover, since the swelling / shrinkage of the film is suppressed by the cross-linking, it is possible to suppress performance degradation due to film tearing or electrode peeling. In addition, fuel hydrogen leakage due to the tearing of the membrane is suppressed, so the fuel consumption of fuel hydrogen is improved. In particular, a crosslinked network type solid polymer electrolyte is chemically cross-linked between polymer chains, so even if the amount of acidic groups is increased, there is no risk that the polymer will flow out, and against swelling and shrinkage of the membrane. High resistance.

  Next, the manufacturing method of the 1st-3rd monomer used for manufacture of the solid polymer electrolyte which concerns on this invention is demonstrated. The first to third monomers can be synthesized by using a commercially available monomer having a similar molecular structure as a starting material, and performing a predetermined functional group conversion using a known method.

For example, a trifunctional monomer “FO ₂ S—CF ₂ —C (F) (SO ₂ F) —CF ₂ —SO ₂ F” having three sulfonyl fluoride groups (halide functional groups) is: It can be synthesized by the procedure shown in Formula 12.

That is, first, 1 g of a commercially available monomer “Cl—CF ₂ —C (F) (Cl) —CF ₂ —Cl” is dissolved in 165 g of dimethylacetamide (DMAC). Next, potassium sulfide (K ₂ S, 6.6 g), sulfur (S, 3.6 g), and cesium fluoride (CsF, 0.6 g) are added, and the mixture is stirred at 190 ° C. for 6 hours in a nitrogen atmosphere. . Thereby, a monomer “S _x —CF ₂ —C (F) (S _x ) —CF ₂ —S _x ” in which the chloride group is substituted with sulfur (S _x ) is obtained (reaction formula (1)).

Next, this monomer is immersed in a 30% aqueous hydrogen peroxide solution at room temperature for 72 hours. Next, treatment with 1N sulfuric acid is performed at 100 ° C. for 1 hour, followed by washing with ion-exchanged water. As a result, the monomer “HO ₃ S—CF ₂ —C (F) (SO ₃ H) —CF ₂ —SO ₃ H” in which the terminal sulfur (S _x ) is substituted with a sulfonic acid group (SO ₃ H group). Is obtained (reaction formula (2)).

Next, this monomer is dissolved in a solution containing 100 g of phosphorus pentachloride (PCl ₅ ) and 250 g of phosphorus oxychloride (POCl ₃ ), and reacted at 90 ° C. for 12 hours. After the reaction, the solvent is removed and washed with carbon tetrachloride (CCl ₄ ) (60 ° C., 3 hours, stirring). As a result, the monomer “ClO ₂ S—CF ₂ —C (F) (SO ₂ Cl) —CF ₂ —— in which the terminal sulfonic acid group (SO ₃ H group) was substituted with a sulfonyl chloride group (SO ₂ Cl group) was obtained. SO ₂ Cl ”is obtained (Scheme (3)).

Further, when this monomer was dissolved in dry tetrahydrofuran (300 ml) together with 15 g of dimethylaminosulfur trifluoride ((CH ₃ ) ₂ NSF ₃ ) and reacted at 45 ° C. for 48 hours, the target monomer “FO ₂ S” was obtained. _{-CF 2 -C (F) (SO} 2 F) -CF 2 -SO 2 F "is obtained (reaction formula (4)).

  Further, for example, a trifunctional monomer “1,3,5-benzenetrisulfonyl chloride” having three sulfonyl chloride groups (halide functional groups) can be synthesized by the procedure shown in the following chemical formula 13. it can.

That is, first, benzenesulfonic acid sodium salt monohydrate (C ₆ H ₅ SO ₃ Na · H ₂ O) 495 g (2.49 mol), concentrated sulfuric acid (H ₂ SO ₄ ) 650 g, sulfuric acid were added to a 3 L reaction vessel. 370.5 g of sodium (NaHSO ₄ ) is charged and reacted at 300 to 330 ° C. for 30 minutes. After cooling the reaction mixture, 1.3 L of water and 310 g of sodium hydroxide (NaOH) are added to make it alkaline. This is adjusted to pH 6 with concentrated sulfuric acid. Activated carbon is added, stirred at 70 ° C. for 30 minutes, filtered while hot and the filtrate is left at 5 ° C. overnight. The precipitated crystals are filtered, and the filtrate is concentrated to stop when crystals start to precipitate, and left at 5 ° C. overnight. The precipitated crystals are filtered and dried to obtain 1,3,5-benzenetrisulfonic acid sodium salt (yield 576 g, yield 60.2%) (reaction formula (1)).

Next, 550 g (1.43 mol) of sodium 1,3,5-benzenetrisulfonate and 2.5 L of thionyl chloride (SOCl ₂ ) are charged into a 5 L reaction vessel, and 330 ml of DMF is added dropwise over 30 minutes at room temperature. . After dropping, the mixture is heated to reflux for 12 hours. The reaction mixture is cooled, poured into 36 kg of ice, the precipitated crystals are filtered, washed with water and dried. When the obtained crude crystals are recrystallized with ethyl acetate, the target monomer “1,3,5-benzenetrisulfonyl chloride (yield 208 g, yield 37.8%)” is obtained (reaction formula (2 )).

  Other monomers having a halide functional group are the same, and can be synthesized by the same or similar procedure as described above. A monomer having an imide functional group is first synthesized with a halide functional group by the same or similar procedure as described above, and then synthesized with ammonia, hexamethyldisilazane (HMDS), hexamethyl. It can be obtained by reacting with disilazane lithium (LiHMDS) or the like to convert all or part of the halide functional group into an imide functional group.

A solid polymer electrolyte membrane was prepared according to the following procedure. First, 2 g of a trifunctional monomer (molecular weight: 315, white powder; hereinafter referred to as “A ₁ monomer”) represented by the following chemical formula 14 was placed in a 50 ml round bottom flask, and dehydrated tetrahydrofuran (THF). 30 ml was added, and the A ₁ monomer was dissolved in THF while stirring for 1 hour under an Ar (N ₂ ) stream.

Next, 6 ml of triethylamine (TEA) was added to this solution and stirred for 30 minutes. Further, to this solution, difunctional monomers of 1.5 mols per mol of the _{A 1} monomer _{"FO 2 S (CF 2) 3} SO 2 F " (molecular weight: 316, density: 1.776g / cm ^3, the transparency Liquid (hereinafter referred to as “B ₁ monomer”) (3.01 g) was added and stirred at 50 ° C. for 1 hour (molar ratio: A ₁ / B ₁ = 1 / 1.5).

When the solution became transparent, the solution was transferred to a glass petri dish. At this time, the amount of the solution was adjusted so that the film thickness was 50 μm. Next, the glass petri dish was put in a glass container under an Ar (N ₂ ) atmosphere and capped. Furthermore, placed in a glass vessel for each autoclave, while maintaining the 50 ° C., were Ar _{(N 2)} flow. This state was left for 7 days to complete the gelation reaction. The obtained film was immersed in 15 wt% nitric acid and subjected to heat treatment at 60 ° C. for 2 hours for washing. As a result, the brown film became a transparent film.

  About the obtained film | membrane, the equivalent weight, the electrical conductivity, and the crosslinking density were measured. The NaCl method was used for measuring the equivalent weight. Moreover, the two-terminal alternating current method (10 kHz) method was used for the measurement of electrical conductivity. Furthermore, the swelling equilibrium method was used for the measurement of the crosslinking density. As a result, the equivalent weight (EW) of the film was 250 g / eq, the electric conductivity was 0.18 S / cm, and the crosslink density was 0.65 mmol / g.

Except that the ratio of _{B 1} monomer for A ₁ monomer and 1.0 moles (2.01 g) are the same steps as in Example 1 to prepare a solid polymer electrolyte membrane (molar _{ratio: A} 1 / A ₂ = 1/1). About the obtained film | membrane, according to the same procedure as Example 1, an equivalent weight, an electrical conductivity, and a crosslinking density were measured. As a result, the equivalent weight (EW) was 370 g / eq, the electrical conductivity was 0.12 S / cm, and the crosslinking density was 0.4 mmol / g.

Except that the ratio of _{B 1} monomer for A ₁ monomer and 1.7 moles (3.41 g) are the same steps as in Example 1 to prepare a solid polymer electrolyte membrane (molar _{ratio: A} 1 / B ₁ = 1 / 1.7). About the obtained film | membrane, according to the same procedure as Example 1, an equivalent weight, an electrical conductivity, and a crosslinking density were measured. As a result, the equivalent weight (EW) was 210 g / eq, the electrical conductivity was 0.20 S / cm, and the crosslinking density was 0.5 mmol / g.

Except that the ratio of _{B 1} monomer for A ₁ monomer and 1.25 mole (2.51 g) are the same steps as in Example 1 to prepare a solid polymer electrolyte membrane (molar _{ratio: A} 1 / B ₁ = 1 / 1.25). About the obtained film | membrane, according to the same procedure as Example 1, an equivalent weight, an electrical conductivity, and a crosslinking density were measured. As a result, the equivalent weight (EW) was 310 g / eq, the electrical conductivity was 0.15 S / cm, and the crosslinking density was 0.5 mmol / g.

Bifunctional monomer “H ₂ NO ₂ S (CF ₂ ) ₃ SO ₂ NH ₂ ” (molecular weight: 310, white powder; hereinafter referred to as “B ₂ monomer”) 2.49 g was placed in a 50 ml round bottom flask. Then, 30 ml of dehydrated tetrahydrofuran (THF) was added thereto, and the B ₂ monomer was dissolved in THF while stirring for 1 hour under a flow of Ar (N ₂ ).

Next, 6 ml of triethylamine (TEA) was added to this solution and stirred for 30 minutes. Further, in this solution, a trifunctional monomer (molecular weight: 373.5, white powder. This is referred to as “A ₂ monomer”), which corresponds to 2/3 times the mole of B ₂ monomer. 2 g was added and stirred at 50 ° C. for 1 hour (molar ratio: A ₂ / B ₂ = 1 / 1.5). The membrane was then synthesized according to the same procedure as in Example 1.

  About the obtained film | membrane, according to the same procedure as Example 1, an equivalent weight, an electrical conductivity, and a crosslinking density were measured. As a result, the equivalent weight (EW) was 250 g / eq, the electric conductivity was 0.18 S / cm, and the crosslinking density was 0.65 mmol / g.

2 g of A ₁ monomer was placed in a 100 ml round bottom flask, 50 ml of dehydrated tetrahydrofuran (THF) was added thereto, and the A ₁ monomer was dissolved in THF while stirring for 1 hour under an Ar (N ₂ ) stream. Next, 2.95 g of 1.5 times moles of B ₂ monomer with respect to A ₁ monomer was added to this solution and stirred for 1 hour.

Next, 10 ml of triethylamine (TEA) was added to this solution and stirred for 30 minutes. Further, to this solution, a 3.0 fold molar _{B 1} monomer 2.95g added to _{A 1} monomers, and stirred for 1 hour at _{50 ℃ (A 1 / B 1} / B 2 = 1/3/1. 5). The membrane was then synthesized according to the same procedure as in Example 1.

  About the obtained film | membrane, according to the same procedure as Example 1, an equivalent weight, an electrical conductivity, and a crosslinking density were measured. As a result, the equivalent weight (EW) was 270 g / eq, the electric conductivity was 0.15 S / cm, and the crosslink density was 0.35 mmol / g.

4.98 g of B ₂ monomer was placed in a 100 ml round bottom flask, 50 ml of dehydrated tetrahydrofuran (THF) was added thereto, and the B ₂ monomer was dissolved in THF while stirring for 1 hour under a stream of Ar (N ₂ ).

Next, 10 ml of triethylamine (TEA) was added to this solution and stirred for 30 minutes. Further, to this solution, and _{A 2} monomers 2.0g 1/3 mol per mol of _{B 2} monomer, a half mole of _{B 1} monomer 2.45g against _{B 2} monomer added, at 50 ° C. The mixture was stirred for 1 hour (A ₂ / B ₁ / B ₂ = 1 / 1.5 / 3). The membrane was then synthesized according to the same procedure as in Example 1.

  About the obtained film | membrane, according to the same procedure as Example 1, an equivalent weight, an electrical conductivity, and a crosslinking density were measured. As a result, the equivalent weight (EW) was 270 g / eq, the electrical conductivity was 0.15 S / cm, and the crosslinking density was 0.35 mmol / g.

Trifunctional monomer “H ₂ NO ₂ SCF ₂ CF (SO ₂ NH ₂ ) CF ₂ SO ₂ NH ₂ ” (molecular weight: 371, white powder; hereinafter referred to as “A ₃ monomer”) 2 g of 50 ml round bottom taken in a flask, to which a dehydrated tetrahydrofuran (THF) 30 ml was added, Ar _{(N 2)} under a stream with stirring for 1 hour to dissolve _{a 3} monomer in THF.

Next, 6 ml of triethylamine (TEA) was added to this solution and stirred for 30 minutes. Further, 2.56 g of a 1.5-fold molar amount of B ₁ monomer with respect to A ₃ monomer was added to this solution, and the mixture was stirred at 50 ° C. for 1 hour (A ₃ / B ₁ = 1 / 1.5). The membrane was then synthesized according to the same procedure as in Example 1.

  About the obtained film | membrane, according to the same procedure as Example 1, an equivalent weight, an electrical conductivity, and a crosslinking density were measured. As a result, the equivalent weight (EW) was 280 g / eq, the electric conductivity was 0.17 S / cm, and the crosslinking density was 0.6 mmol / g.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

The polymer electrolyte according to the present invention is particularly suitable as an electrolyte membrane for a polymer electrolyte fuel cell and an electrolyte in a catalyst layer, but the application of the present invention is not limited to this, and is applicable to various electrochemical devices. It can also be used as an electrolyte membrane to be used, an electrolyte in a catalyst layer, and the like.

Claims (17)

A solid polymer electrolyte obtained by reacting one or more first monomers satisfying the following conditions with one or more second monomers.
(1) The first monomer has a molecular weight of 10,000 or less and includes n (n ≧ 2) reactive functional groups A and / or reactive functional groups B in one molecule.
(2) The second monomer has a molecular weight of 10,000 or less and includes m (m ≧ 3, m ≠ n) of the reactive functional group A and / or the reactive functional group B in one molecule. Consists of things.
(3) The reactive functional group A and the reactive functional group B are bissulfonimide group (—SO ₂ NHSO ₂ —), sulfoncarbonimide group (—SO ₂ NHCO—), or bis by these reactions. It consists of what forms a carbonimido group (-CONHCO-).
(4) The one or more types of the first monomer and the one or more types of the second monomer may include at least one reactive functional group A and at least one It comprises the reactive functional group B.   The one or more kinds of the first monomers and the one or more kinds of the second monomers each include at least two of the reactive functional groups A and at least two of the reactive properties. The solid polymer electrolyte according to claim 1, comprising a functional group B. Either one of the reactive functional group A and the reactive functional group B is —SO ₂ X or —COX (where X is F, Cl, Br, I, or OH), and the other is 3. The method according to claim ₁ , comprising —SO ₂ NZ ₁ Z ₂ , or —CONZ ₁ Z ₂ , wherein Z ₁ and Z ₂ are H, M, and SiMe ₃ , respectively, and M is a metal ion. Solid polymer electrolyte. The first monomer comprises one or more of monomers (1) to monomers (8) shown in the following chemical formula 1 and monomers (9) to monomers (18) shown in the chemical formula 2;
The said 2nd monomer consists of any one or more of the said monomer (5) to the said monomer (8), and the said monomer (15) to the said monomer (18). Solid polymer electrolyte.

  A porous membrane is impregnated with a solution containing one or more kinds of first monomers and one or more kinds of second monomers according to any one of claims 1 to 4, and said one kind or two A solid polymer electrolyte obtained by reacting at least one first monomer and one or more second monomers.   The solid polymer electrolyte according to any one of claims 1 to 5, wherein the cross-linking density is 0.1 mmol / g or more.   A mixed liquid comprising one or more first monomers according to any one of claims 1 to 4 and one or more second monomers is prepared, and the first monomer and the first monomer are prepared. A method for producing a solid polymer electrolyte, comprising reacting two monomers.   A fuel cell using the solid polymer electrolyte according to any one of claims 1 to 6. A solid polymer electrolyte obtained by reacting one or more third monomers satisfying the following conditions.
(1) The third monomer has a molecular weight of 10,000 or less and includes p (p ≧ 3) reactive functional groups A and / or reactive functional groups B in one molecule.
(2) The reactive functional group A and the reactive functional group B are converted into a bissulfonimide group (—SO ₂ NHSO ₂ —), a sulfoncarbonimide group (—SO ₂ NHCO—), or bis by these reactions. It consists of what forms a carbonimido group (-CONHCO-).
(3) The one kind or two or more kinds of third monomers are composed of any of these containing at least one reactive functional group A and at least one reactive functional group B. . The third monomer is two or more types of monomers including a total of three reactive functional groups A and / or reactive functional groups B in one molecule,
The solid polymer electrolyte according to claim 9, wherein any of these includes at least two of the reactive functional groups A and at least two of the reactive functional groups B. The third monomer is one or more monomers including a total of four or more reactive functional groups A and / or reactive functional groups B in one molecule,
The solid polymer electrolyte according to claim 9, wherein any of these includes at least two of the reactive functional groups A and at least two of the reactive functional groups B. Either one of the reactive functional group A and the reactive functional group B is —SO ₂ X or —COX (where X is F, Cl, Br, I, or OH), and the other is -SO ₂ NZ ₁ Z _2, or -CONZ ₁ Z _{2 (where,} Z 1, _{Z 2} are each, H, M, or SiMe ₃ .M, the metal ion.) of claims 9 consisting of up to 11 The solid polymer electrolyte according to any one of the above. The third monomer is composed of at least one of a monomer (5) to a monomer (8) shown in the following chemical formula 3 and a monomer (15) to a monomer (18) shown in the chemical formula 4. Item 13. The solid polymer electrolyte according to any one of Items 9 to 12.

  A porous membrane is impregnated with a solution containing one or more third monomers according to any one of claims 9 to 13, and the one or more third monomers are reacted. Obtained solid polymer electrolyte.   The solid polymer electrolyte according to any one of claims 9 to 14, which has a crosslinking density of 0.1 mmol / g or more.   A method for producing a solid polymer electrolyte, comprising preparing a mixed solution containing one or more third monomers according to any one of claims 9 to 13 and reacting the third monomers. A fuel cell using the solid polymer electrolyte according to any one of claims 9 to 15.