WO2011049211A1 - Polyarylene copolymer having, in side chain thereof, aromatic ring containing phosphonate group - Google Patents

Abstract

Disclosed is a polyarylene copolymer which contains a structure having a phosphonated aromatic ring in a side chain thereof, and which is useful for the production of a proton conductive film that is applicable to electrolytes for primary batteries, electrolytes for secondary batteries, polymeric solid electrolytes for fuel cells, display elements, various types of sensors, signaling media, solid capacitors, ion exchange membranes and the like. Specifically disclosed is a polyarylene copolymer characterized by containing a structural unit represented by general formula (1). (In formula (1), E's independently represent at least one structure selected from the group consisting of a direct bond and groups -O-, -S-, -CO-, -SO₂-, -SO-, -CONH- and -COO-; Ar³¹, Ar³² and Ar³³ independently represent a bivalent or trivalent organic group having a benzene ring, a naphthalene ring or a nitrogenated heterocyclic ring, or an organic group produced by substituting one, some or all of hydrogen atoms by a fluorine atom or fluorine atoms in the aforementioned organic groups; R³¹ represents at least one structure selected from the group consisting of a direct bond, -O(CH₂)_p-, -O(CF₂)_p-, -(CH₂)_p- and -(CF₂)_p- (wherein p represents an integer of 1 to 12); e represents an integer of 0 to 10; f represents an integer of 1 to 5; g represents an integer of 0 to 4; and h represents an integer of 0 to 1.)

Description

Polyarylene copolymer having an aromatic ring containing a phosphonic acid group in the side chain

The present invention relates to a polyarylene copolymer and a proton conductive membrane using the same, and more specifically, an electrolyte for a primary battery, an electrolyte for a secondary battery, a polymer solid electrolyte for a fuel cell, a display element, various sensors, The present invention relates to a polyarylene-based copolymer including a structure having an aromatic ring phosphonated in a side chain, which is useful for a proton conductive membrane usable for a signal transmission medium, a solid capacitor, an ion exchange membrane, and the like.

A fuel cell is a power generation system that has high power generation efficiency and a low burden on the environment with less emissions. In recent years, with the growing interest in protecting the global environment and escaping from fossil fuel dependence, it is in the spotlight. Fuel cells are expected to be installed in small distributed power generation facilities, power generation devices as driving sources for mobile objects such as automobiles and ships, and mobile phones and mobile personal computers that replace secondary batteries such as lithium ion batteries. ing.

A polymer electrolyte fuel cell is provided with a pair of electrodes on both sides of a proton-conducting solid polymer electrolyte membrane, and supplies pure hydrogen or reformed hydrogen gas as fuel to one electrode (fuel electrode). Air is supplied as an oxidizing agent to different electrodes (air electrodes) to obtain an electromotive force. In water electrolysis, water is electrolyzed using a solid polymer electrolyte membrane to produce a reverse reaction of the fuel cell reaction to produce hydrogen and oxygen.

However, in actual fuel cells and water electrolysis, side reactions occur in addition to these main reactions. A typical example is the generation of hydrogen peroxide (H ₂ O ₂ ), and the radical species resulting from the hydrogen peroxide cause the solid polymer electrolyte membrane to deteriorate.

Conventionally, as solid polymer electrolyte membranes, Nafion (registered trademark, manufactured by DuPont), Aciplex (registered trademark, manufactured by Asahi Kasei Kogyo Co., Ltd.), Flemion (registered trademark, manufactured by Asahi Glass Co., Ltd.) Perfluorosulfonic acid membranes commercially available from U.S.A. have been used because of their excellent chemical stability.

However, since perfluorosulfonic acid membranes such as Nafion are difficult to manufacture, there is a problem that they are very expensive, and are widely used in consumer applications such as fuel cell vehicles and household fuel cell power generation systems. It is an obstacle. In addition, since it has a large amount of fluorine atoms in the molecule, the disposal treatment after use also has a problem of a heavy load on the environment.

Also, the higher the temperature of the fuel cell and the thinner the proton conducting membrane between the electrodes, the smaller the membrane resistance and the higher the power generation output. However, these perfluorosulfonic acid membranes have a thermal deformation temperature of about 80 to 100 ° C. and very poor creep resistance at high temperatures. Therefore, the power generation temperature when these membranes are used in a fuel cell is 80 There is a problem that power generation output is limited because it must be kept below ℃. In addition, the film thickness is poor when used for a long period of time, and a certain degree of film thickness (50 μm or more) is necessary to prevent short-circuiting between the electrodes. Yes.

In order to solve such problems of perfluorosulfonic acid membranes, solid polymer electrolyte membranes that do not contain fluorine atoms, are cheaper, and have a heat-resistant main chain skeleton that is also used for engineer plastics are currently available. Many studies have been conducted. Polymers in which a main chain aromatic ring of polyarylene, polyetheretherketone, polyethersulfone, polyphenylene sulfide, polyimide, or polybenzazole is sulfonated have been proposed (Non-Patent Documents 1 to 3).

However, the hydrocarbon-based solid polymer electrolyte membrane is required to be chemically resistant because degradation is accelerated by hydrogen peroxide generated by a side reaction during power generation. For this reason, for the purpose of improving chemical resistance, various additives such as hindered phenols as radical scavengers and compounds containing phosphorus and sulfur as peroxide decomposing agents have been studied (Patent Document 1). ~ 3).

Further, an electrolyte membrane in which a substituent containing phosphorus such as a phosphonic acid group, a phosphoric acid group, a phosphonic acid ester group, and a phosphoric acid ester group is introduced into the electrolyte polymer itself has been studied, and one of the methods for evaluating radical resistance. In the Fenton test and the exposure test under hydrogen peroxide vapor, it has been shown that radical resistance is improved (Patent Documents 4 to 10). For example, Patent Document 10 and Patent Document 5 are electrolyte membranes using graft polystyrene containing a phosphonic acid group as a non-fluorine electrolyte membrane, and it is shown that the weight retention rate is improved before and after the Fenton test. ing. Polyethersulfone as disclosed in Patent Document 4 is not a hydrocarbon electrolyte membrane in which the main chain is an alkyl chain such as a methylene group such as polystyrene, but a hydrocarbon electrolyte membrane containing an aromatic in the main chain, Examples include polyphenylene oxide shown in Document 7, polyphenylene shown in Patent Document 6, and polyarylene shown in Patent Document 9.

JP 2003-183526 A JP 2004-134294 A Japanese Patent No. 4139912 Japanese Patent Laid-Open No. 2003-282096 Special Table 2007-525563 JP 2004-175997 A JP 2007-238806 A JP 2007-217675 A JP 2003-327664 A JP 2000-11755 A

Polymer Preprints, Japan, Vol. 42, No. 7, p. 2490-2492 (1993) Polymer Preprints, Japan, Vol. 43, No. 3, p. 735-736 (1994) Polymer Preprints, Japan, Vol. 42, No. 3, p. 730 (1993)

However, when a proton conductive group containing phosphorus such as a phosphonic acid group is introduced instead of a sulfonic acid group generally used for an electrolyte membrane, in many cases, a decrease in conductivity is a problem.

For example, as shown in the Examples of Patent Document 10, in the case of graft polystyrene in which all the electrically conductive groups are sulfonic acid groups, the conductivity is 0.182 (S / cm), while a part is It is shown that the substitution to the phosphonic acid group decreases to 0.109 to 0.145 (S / cm) depending on the substitution rate.

Patent Document 5 discloses an electrolyte membrane made of grafted polystyrene containing all phosphonic acid groups, but the conductivity is about 10 ⁻⁵ (S / cm).

Patent Document 6 is an example of introducing a phosphonic acid group into a side chain in a hydrocarbon-based electrolyte membrane containing an aromatic group in the main chain, but introducing a phosphonic acid group only into an aromatic ring having a high electron density, The conductivity is about 10 ⁻⁴ (S / cm).

Patent Document 9 discloses an electrolyte membrane composed of a sulfonated polyarylene in which a phosphonic acid ester group is introduced instead of a phosphonic acid group on an aromatic ring having a low electron density. However, in the Fenton test, the weight retention rate is 20 hours. It is about 90%, and cannot always be said to have sufficient radical resistance. Moreover, since it is in the state of a phosphonic acid ester group instead of phosphonic acid, proton conductivity is low, and when the addition amount is increased, a portion contributing to proton conduction is reduced and a decrease in conductivity is expected. For this reason, it is difficult to introduce a phosphonate group at a high concentration.

Thus, in the conventional hydrocarbon-based electrolyte membrane, there has been no electrolyte membrane having sufficient proton conductivity in a wide temperature range while having resistance to radicals.

An object of the present invention is to solve the problems of fluorine-based electrolyte membranes and aromatic-based electrolyte membranes that have been studied conventionally, to improve deterioration resistance against radicals, and to have excellent proton conductivity, and The object is to provide a proton conducting membrane made of an electrolyte.

As a result of intensive studies to achieve the above object, the present inventors have found that phosphones are present in aromatic rings having a low side chain electron density, that is, aromatic rings having electron-withdrawing bonds such as CO and SO _2. The inventors have found that a polymer electrolyte composed of a polyarylene copolymer having an acid group satisfies the object of the present invention, and has completed the present invention.

That is, the gist of the present invention is as follows.
<1> A polyarylene copolymer comprising a structural unit represented by the following general formula (1).

(In the formula (1), each E is independently selected from the group consisting of a direct bond, —O—, —S—, —CO—, —SO ₂ —, —SO—, —CONH—, and —COO— groups. Shows at least one selected structure,
Ar ³¹ and Ar ³³ are each independently a divalent or trivalent organic group having a benzene ring, a naphthalene ring or a nitrogen-containing heterocyclic ring, or an organic group in which part or all of the hydrogen atoms are substituted with fluorine atoms. Indicates.

Ar ³² independently represents a divalent to hexavalent organic group having a benzene ring, a naphthalene ring or a nitrogen-containing heterocyclic ring, or an organic group in which part or all of the hydrogen atoms are substituted with fluorine atoms.

R ³¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, and — (CF ₂ ) _p —. (P represents an integer of 1 to 12).

e represents an integer of 0 to 10,
f represents an integer of 1 to 5,
g represents an integer of 0 to 4, and h represents an integer of 0 to 1. )
<2> A polyarylene copolymer of <1> comprising a structural unit represented by the following general formula (2).

Wherein (2) and E are each independently selected from the group consisting of a direct bond, —O—, —S—, —CO—, —SO ₂ —, —SO—, —CONH—, —COO—. Shows at least one selected structure,
R ³¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, and — (CF ₂ ) _p —. (P represents an integer of 1 to 12).

e represents an integer of 0 to 10,
f represents an integer of 1 to 5,
g represents an integer of 0 to 4,
h represents an integer of 0 to 1. )
<3> The polyarylene copolymer according to <1> or <2>, further comprising a structural unit having a sulfonic acid group.
<4> The polyarylene copolymer according to <3>, wherein the structural unit having a sulfonic acid group includes a structural unit having a sulfonic acid group represented by the following general formula (3-1).

[In Formula (3-1), Y is —CO—, —SO ₂ —, —SO—, a direct bond, — (CF ₂ ) _u — (u is an integer of 1 to 10), —C (CF ₃ ) represents at least one structure selected from the group consisting of ₂ —, —CONH—, —COO—, Z is a direct bond, or — (CH ₂ ) ₁ — (l is an integer of 1 to 10) ), —C (CH ₃ ) ₂ —, —O—, —S—, —CO—, —SO ₂ —, —SO—, wherein Ar represents —SO An aromatic group having a substituent represented by ₃ H or —O (CH ₂ ) _p SO ₃ H or —O (CF ₂ ) _p SO ₃ H is shown. p represents an integer of 1 to 12, m represents an integer of 0 to 3 (0, 1), n represents an integer of 0 to 3 (0, 1), and k represents an integer of 1 to 4 (1) Indicates. Among the single lines at the end of the structural unit, those not having a substituent displayed on one side mean connection with the adjacent structural unit. ]
<5> A polyarylene copolymer of <1> to <4>, further comprising a structural unit having an aromatic structure represented by the following general formula (4-1).

[In Formula (4-1), A and D are independently a direct bond, or —CO—, —SO ₂ —, —SO—, — (CF ₂ ) _l — (l is an integer of 1 to 10). , — (CH ₂ ) ₁ — (l is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group and a halogenated hydrocarbon group), It represents at least one structure selected from the group consisting of a cyclohexylidene group, a fluorenylidene group, —O—, and —S—, B is independently an oxygen atom or a sulfur atom, and R ¹ to R ¹⁶ are They may be the same or different and are selected from the group consisting of a hydrogen atom, a fluorine atom, a nitro group, a nitrile group, or an alkyl group, an allyl group, or an aryl group, in which some or all of the hydrogen atoms may be fluorine-substituted. And at least one atom or group. s and t represent integers of 0 to 4 (0, 1, 2), and r represents 0 or an integer of 1 or more. ]
<6> When the molar number of phosphonic acid groups contained in 1 mol of polyarylene copolymer is (d) and the molar number of sulfonic acid groups is (e), (d) / {(d) + (e) } The polyarylene copolymer of <1> to <5>, wherein the value of × 100 is 0.01 to 100.
<7> The polyarylene copolymer according to <5>, wherein the value of (d) / {(d) + (e)} × 100 is 0.1 to less than 7.
<8> A polymer electrolyte comprising the copolymer of <1> to <7>.
<9> The polymer electrolyte according to <8>, having an ion exchange capacity of 0.5 to 3.5 meq / g.

The polyarylene copolymer of the present invention is a polyarylene copolymer having a phosphonic acid group on an aromatic ring having a low electron density in the side chain, that is, an aromatic ring having an electron-withdrawing bond such as CO and SO _2. Polymer electrolytes composed of coalescents have the characteristics that have not been seen before, firstly, they have improved radical resistance to peroxides, and secondly, they have high proton conductivity. Yes. Therefore, the polymer electrolyte of the present invention is used as a conductive membrane for primary battery electrolytes, secondary battery electrolytes, polymer solid electrolytes for fuel cells, display elements, various sensors, signal transmission media, solid capacitors, ion exchange membranes, and the like. The industrial significance is extremely large.

Hereinafter, the present invention will be described in detail.
Polyarylene-based copolymer The polyarylene-based copolymer of the present invention has a structural unit having a phosphonic acid group, and preferably further has a structural unit having a sulfonic acid group and a structural unit having an aromatic structure.
[Structural unit having phosphonic acid group]
The structural unit having a phosphonic acid group is represented by the following formula (1).

In formula (1), each E is individually selected from the group consisting of a direct bond, —O—, —S—, —CO—, —SO ₂ —, —SO—, —CONH—, and —COO— groups. At least one structure is shown. Of these, —CO— and —SO ₂ — are preferable.

Ar ³¹ , Ar ³² , Ar ³³ may be the same or different, and may be substituted with a fluorine atom, and at least one structure selected from the group consisting of a benzene ring, a naphthalene ring, and a nitrogen-containing heterocyclic ring Indicates. The nitrogen-containing heterocycle includes pyrrole, 2H-pyrrole, imidazole, pyrazole, isothiazole, isoxazole, pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole, 3H-indole, indole, 1H-indazole, purine. 4H-quinolidine, quinoline, isoquinoline, phthalazine, naphthyridine, quinoxaline, quinazoline, cinnoline, pteridine, carbazole, carboline, phenanthridine, acridine, perimidine, phenanthroline, phenazine, phenothiazine, furazane, phenoxazine, pyrrolidine, imidazoline, imidazoline Imidazolidine, pyrazolidine, pyrazoline, piperidine, piperazine, indoline, isoindoline, quinuclidine, oxazole, ben Examples include oxazole, 1,3,5-triazine, bromine, tetrazole, tetrazine, triazole, phenalsazine, benzimidazole, benzotriazole, thiazole, benzothiazole, and benzothiadiazole, including imidazole, pyridine, 1,3,5- Triazine and triazole are preferred.

R ³¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, and — (CF ₂ ) _p —. (P represents an integer of 1 to 12).

E represents an integer of 0 to 10, preferably 0 to 5, more preferably 0 to 2.

F represents an integer of 1 to 5, preferably 1 to 4, more preferably 1 to 3.

G represents an integer of 0 to 4, preferably 0 to 3, more preferably 0 to 2.

H indicates an integer from 0 to 1.

The structural unit having a phosphonic acid group is preferably represented by the following formula (2).

(Equation ^{(2), E, R 31, e,} f, g, h are the same as in the formula (1). Furthermore, more desirably those of h = 1)
Specific examples of the structural unit having a phosphonic acid group include the following.

The polyarylene-based copolymer of the present invention includes a structural unit having a phosphonic acid group, whereby durability can be improved while maintaining high proton conductivity. It is assumed that the durability is improved because radical resistance to peroxide is improved by introducing a phosphonic acid group. In particular, when h = 1 in the above formula (1) and E is a —CO—, —SO ₂ —, —SO—, —CONH—, —COO— group, that is, the electron density is low. This means that a phosphonic acid group is introduced into the aromatic ring, and the polyarylene copolymer of the present invention can improve radical resistance against peroxides and can maintain higher proton conductivity. Furthermore, in the present invention, since it is introduced in the state of a deprotected phosphonic acid group instead of a phosphonic acid ester group, the proton conductivity is greatly reduced by introduction like a non-conductive phosphonic acid ester group. The conductivity can be maintained without doing so.

In the polyarylene polymer of the present invention, it is desirable that at least two structural units represented by the above formula (1) are continuous from the viewpoint of mechanical strength and hot water resistance of the obtained electrolyte membrane. More preferably, at least 3 consecutive, and more preferably at least 5 consecutive.
[Structural unit having sulfonic acid group]
Examples of the structural unit having a sulfonic acid group include a structural unit represented by the following formula (3). The polyarylene-based copolymer of the present invention can have higher proton conductivity by including a structural unit having a sulfonic acid group. Moreover, the polyarylene-type copolymer of this invention can improve durability, maintaining a high proton conductivity by having the structural unit which has the phosphonic acid group mentioned above, and a sulfonic acid group. This is presumably because the elimination of the sulfonic acid group is suppressed by having the phosphonic acid group.

In the above formula (3), Ar ¹¹ , Ar ¹² , and Ar ¹³ are each independently a group consisting of a condensed aromatic ring such as a benzene ring and a naphthalene ring, or a nitrogen-containing heterocyclic ring, which may be substituted with a fluorine atom. A divalent or trivalent group having at least one selected structure is shown.

Y is —CO—, —SO ₂ —, —SO—, — (CF ₂ ) _u — (u is an integer of 1 to 10), —C (CF ₃ ) ₂ —, —CONH—, —COO -Or indicates direct binding.

Z is —O—, —S—, direct bond, —CO—, —SO ₂ —, —SO—, — (CH ₂ ) _l — (l is an integer of 1 to 10), or C (CH ₃ ) ₂ -is shown.

R ¹¹ represents a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p — or (CF ₂ ) _p — (p is an integer of 1 to 12) Showing).

R ¹² and R ¹³ are each independently at least one structure selected from the group consisting of a hydrogen atom, an alkali metal atom, an aliphatic hydrocarbon group, an alicyclic group, or a hydrocarbon group containing a heterocyclic ring containing oxygen. Indicates. However, at least one of all R ¹² and R ¹³ included in the above formula is a hydrogen atom.

x ¹ is an integer from 0 to 4, x ² is an integer from 1 to 5, a is an integer from 0 to 1, and b is an integer from 0 to 3.

The structural unit having a sulfonic acid group is preferably composed of a repeating unit represented by the following formula (3-1).

In the above formula, Ar ¹¹ , Ar ¹² , and Ar ¹³ are each independently selected from the group consisting of a condensed aromatic ring such as a benzene ring and a naphthalene ring, which may be substituted with a fluorine atom, and a nitrogen-containing heterocyclic ring. At least one structure is shown.

Y is —CO—, —CONH—, —COO—, —SO ₂ —, —SO—, — (CF ₂ ) _u — (u is an integer of 1 to 10), —C (CF ₃ ) ₂ -Represents at least one structure selected from the group consisting of direct bonds.

Z is —O—, —S—, direct bond, —CO—, —SO ₂ —, —SO—, — (CH ₂ ) _l — (l is an integer of 1 to 10), —C (CH ₃ ) At least one structure selected from the group consisting of _2- .

R ¹¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, and — (CF ₂ ) _p —. (P represents an integer of 1 to 12).

R ¹² and R ¹³ are each independently at least one structure selected from the group consisting of a hydrogen atom, an alkali metal atom, an aliphatic hydrocarbon group, an alicyclic group, or a hydrocarbon group containing a heterocyclic ring containing oxygen. Indicates. However, at least one of all R ¹² and R ¹³ included in the above formula is a hydrogen atom.

x ¹ is an integer from 0 to 4, x ² is an integer from 1 to 5, a is an integer from 0 to 1, and b1 and b2 are integers from 0 to 3.

The repeating unit represented by the above formula (3) or (3-1) preferably has a structure represented by the following formula (3-2).

[In the formula (3-2), Y represents —CO—, —SO ₂ —, —SO—, a direct bond, — (CF ₂ ) _u — (u is an integer of 1 to 10), —C (CF ₃ ) at least one structure selected from the group consisting of ₂ —, —CONH— and —COO—, wherein Z is a direct bond or — (CH ₂ ) ₁ — (l is an integer of 1 to 10) ), —C (CH ₃ ) ₂ —, —O—, —S—, —CO—, —SO ₂ —, —SO—, wherein Ar represents —SO An aromatic group having a substituent represented by ₃ H or —O (CH ₂ ) _p SO ₃ H or —O (CF ₂ ) _p SO ₃ H is shown. p represents an integer of 1 to 12, m represents an integer of 0 to 3, n represents an integer of 0 to 3, and k represents an integer of 1 to 4. Among the single lines at the end of the structural unit, those not having a substituent displayed on one side mean connection with the adjacent structural unit. ]
m is preferably 0 or 1,
n is preferably 0 or 1,
k is preferably 1.

Specific examples of the structural unit having a sulfonic acid group include the following.

Moreover, the polyarylene polymer of the present invention is represented by the above formula (1) when it contains the structural unit represented by the above formula (3) from the viewpoint of the mechanical strength and hot water resistance of the obtained electrolyte membrane. And at least one selected from the structural unit represented by the above formula (3) is preferably at least 2 consecutive, more preferably at least 3 continuous, and at least 5 continuous. It is even more desirable.
[Structural unit having aromatic structure]
The structural unit having an aromatic structure is represented by the following formula (4).

In the above formula, Ar ²¹ , Ar ²² , Ar ²³ , and Ar ²⁴ each independently represent a divalent group having a benzene ring, a condensed aromatic ring (such as a naphthalene ring) or a nitrogen-containing heterocyclic ring structure.

However, Ar ²¹ , Ar ²² , Ar ²³ , and Ar ²⁴ may be such that some or all of the hydrogen atoms are fluorine-substituted, nitro, nitrile, or some or all of the hydrogen atoms are halogen-substituted. It may be substituted with at least one atom or group selected from the group consisting of an alkyl group, an allyl group or an aryl group.

A and D are each independently a direct bond or —CO—, —COO—, —CONH—, —SO ₂ —, —SO—, — (CF ₂ ) _l — (l is an integer of 1 to 10) A), — (CH ₂ ) ₁ — (wherein 1 is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group and a halogenated hydrocarbon group) ), Cyclohexylidene group, fluorenylidene group, —O— or S—
B is an oxygen atom or a sulfur atom,
s and t each independently represent an integer of 0 to 4, and r represents 0 or an integer of 1 or more.

The structural unit having an aromatic structure is preferably one represented by the following formula (4-1).

[In Formula (4-1), A and D are independently a direct bond, or —CO—, —SO ₂ —, —SO—, — (CF ₂ ) _l — (l is an integer of 1 to 10). , — (CH ₂ ) ₁ — (l is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group and a halogenated hydrocarbon group), It represents at least one structure selected from the group consisting of a cyclohexylidene group, a fluorenylidene group, —O—, and —S—, B is independently an oxygen atom or a sulfur atom, and R ¹ to R ¹⁶ are They may be the same or different and are selected from the group consisting of a hydrogen atom, a fluorine atom, a nitro group, a nitrile group, or an alkyl group, an allyl group, or an aryl group, in which some or all of the hydrogen atoms may be fluorine-substituted. And at least one atom or group. s and t represent an integer of 0 to 4, and r represents 0 or an integer of 1 or more. ]
s and t are preferably integers of 0, 1, and 2.

Specific examples of such structural units include the following.

When the above aromatic ring structural unit is contained, the hydrophobicity of the copolymer is remarkably improved. For this reason, the outstanding hot water tolerance can be provided, providing the proton conductivity similar to the past. Further, when at least one of R ¹ to R ¹⁶ is a nitrile group, the dimensional stability in the hot water resistance test is excellent.
[Polyarylene copolymer]
The polyarylene copolymer of the present invention is represented by the following general formula (5).

In the general formula (5), A, B, D, Y, Z, Ar ¹¹ , Ar ¹² , Ar ¹³ , Ar ²¹ to Ar ²⁴ , Ar ³¹ to Ar ³³ , a, b, e, f, g, h, k, s, t, r, x ¹ , x ² and R ¹¹ to R ¹³ , R ³¹ are A, B, D, Y, Z, Ar ¹¹ in the above general formulas (1) to (4), respectively. Ar ¹² , Ar ¹³ , Ar ²¹ to Ar ²⁴ , Ar ³¹ to Ar ³³ , a, b, e, f, g, h, k, s, t, r, x ¹ , x ² and R ¹¹ to R ¹³ , It has the same meaning as R ^31. x, y, and z indicate molar ratios when x + y + z = 100 mol%.

The number of moles of the structural unit represented by the formula (1) possessed by 1 mole of the polyarylene copolymer used in the present invention is (x), and the number of moles of the structural unit represented by the formula (3) is (y). When the number of moles of the structural unit represented by formula (4) is (z), the value of (x) / {(x) + (y) + (z)} × 100 is preferably 0.05. -100, more preferably 0.5-99.9, and particularly preferably 1-90.

The value of (y) / {(x) + (y) + (z)} × 100 is preferably 0 to 99.95, more preferably 0 to 99.4, and particularly preferably 0. ~ 98 mol%.

The value of (z) / {(x) + (y) + (z)} × 100 is preferably 0 to 99.5, more preferably 0.01 to 99, and particularly preferably 0. 1 to 98.

(D) / {(d) + (e)} × 100, where (d) is the number of moles of phosphonic acid groups per mole of polyarylene-based copolymer and (e) is the number of moles of sulfonic acid groups. Is preferably from 0.01 to 100, more preferably from 0.1 to 50, even more preferably from 0.1 to 20, and from the standpoint of maintaining high proton conductivity, It is more preferably 1 to less than 7, and further preferably 3 to 10 from the viewpoint of improving the durability. By setting the value of (d) / {(d) + (e)} × 100 in the above range, proton conductivity is high, power generation performance can be increased, and durability can be improved.
[Polymer synthesis method]
The polyarylene copolymer of the present invention can be produced using, for example, the following three methods: A1, Method B1, and C1.
(A1 method)
For example, in the method described in JP-A No. 2004-137444, a phosphonic acid compound that becomes a structural unit having a phosphonic acid group, a sulfonic acid ester that becomes a structural unit having a sulfonic acid group, if necessary, and an aromatic structure Is synthesized by copolymerizing a monomer or oligomer that is a structural unit having phosphonic acid ester groups, deesterifying phosphonate groups, deionizing phosphonate salts, and converting sulfonic acid ester groups to sulfonic acid groups. Can do. However, in the case of synthesizing a polyarylene copolymer in which the value of (d) / ((d) + (e)) × 100 is 100, a structure having a sulfonic acid group in the above synthesis method. Synthesize without using sulfonic acid ester as unit.
(1) Phosphonic acid compound to be a structural unit having a phosphonic acid group The structural unit having a phosphonic acid group is, for example, the following general formula (1-1) or (1-2) as a polymerization raw material for a polyarylene copolymer. It can manufacture by using the aromatic compound represented by.

In the formulas (1-1) and (1-2), E, Ar ³¹ , Ar ³² , Ar ³³ , e, f, g, and h are the same as those in the formula (1).

R ³¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, and — (CF ₂ ) _p —. (P represents an integer of 1 to 12).

R ³² represents an alkyl group, a fluorine-substituted alkyl group, an aryl group, a metal ion, an onium ion, or hydrogen. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an amyl group, a hexyl group, a cyclohexyl group, and an octyl group. Examples of the fluorine-substituted alkyl group include a trifluoromethyl group, a pentafluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group. Examples of the allyl group include a propenyl group, and examples of the aryl group include a phenyl group and a pentafluorophenyl group. Among these, a methyl group, an ethyl group, a propyl group, an isopropyl group, and a phenyl group are preferable.

Examples of the metal ion include alkali metal sodium ion, potassium ion, lithium ion, alkaline earth metal magnesium and calcium. Of these, sodium ion, potassium ion, and lithium ion are particularly preferable.

Examples of onium ions include ammonium, phosphonium, oxonium, and sulfonium.

X represents an atom or group selected from halogen atoms excluding fluorine (chlorine, bromine, iodine) and —OSO ₂ Rb (where Rb represents an alkyl group, a fluorine-substituted alkyl group or an aryl group). Of these, chlorine and bromine are preferred.

Examples of the compound represented by the formula (1-1) include the structures shown below.

In addition, the bonding position of the phosphonic acid group is not limited to the p position, and may be the o position or the m position.

In the formula (1-2), R ³³ is represented _by- (CR ³⁴ R ³⁵ ) _h1- (CR ³⁶ R ³⁷ ) _h2- (CR ³⁸ R ³⁹ ) _h3- (CR ⁴⁰ R ⁴¹ ) _b4- Indicates a valent group. Preferably, R ³³ is an alkylene group which may be branched.

R ³⁴ to R ⁴¹ may be the same or different and each represents a group selected from a hydrogen atom, a fluorine atom, an alkyl group, a fluorine-substituted alkyl group, an allyl group, and an aryl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an amyl group, a hexyl group, a cyclohexyl group, and an octyl group. Examples of the fluorine-substituted alkyl group include a trifluoromethyl group, a pentafluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group. Examples of the allyl group include a propenyl group, and examples of the aryl group include a phenyl group and a pentafluorophenyl group. Among these, a methyl group, an ethyl group, a propyl group, an isopropyl group, and a phenyl group are preferable. h1, h2, h3, and h4 may be the same as or different from each other, and are 0 or 1, and h1 + h2 + h3 + h4 is 2 or more.

Specific examples of the structure represented by the formula (1-2) include the structures shown below.

(X represents a halogen atom)

In addition, the bonding position of the phosphonic acid group is not limited to the p position, and may be the o position or the m position.

Further, as a derivative of the aromatic compound represented by the above general formulas (1-1) and (1-2), a compound in which a chlorine atom is replaced with a bromine atom in the above compound, a —CO— There -SO 2 _- compound replaced by a chlorine atom in the compound is replaced with a bromine atom, and -CO- is -SO 2 _- can also be mentioned such compounds replaced.

The above compound can be prepared by a substitution reaction of a precursor in which a bromine atom is introduced in advance at a substitution site where a phosphonic acid group is introduced, and a phosphonic acid ester, phosphonic acid salt, or phosphonic acid. In the case of a phosphonate, neutralization may be performed after introducing phosphonic acid.
(2) Sulfonic acid ester which becomes a structural unit having a sulfonic acid group The polyarylene copolymer of the present invention may have a structural unit having a sulfonic acid group. The structural unit having a sulfonic acid group can be introduced by using, for example, a sulfonic acid ester represented by the following formula (3-3) as a polymerization raw material for the polyarylene-based copolymer.

In the above formula (3-3), Ar ¹¹ , Ar ¹² , and Ar ¹³ each independently comprises a condensed aromatic ring such as a benzene ring or a naphthalene ring, or a nitrogen-containing heterocycle, which may be substituted with a fluorine atom. 1 shows at least one structure selected from the group.

X represents at least one structure selected from the group consisting of chlorine, bromine, iodine, methanesulfonyl group, trifluoromethanesulfonyl group, benzenesulfonyl group, and toluenesulfonyl group.

Y represents —CO—, —COO—, CONH—, —SO ₂ —, —SO—, — (CF ₂ ) _u — (u is an integer of 1 to 10), —C (CF ₃ ) ₂ —. And at least one structure selected from the group consisting of direct bonds.
Z is —O—, —S—, direct bond, —CO—, —SO ₂ —, —SO—, — (CH ₂ ) _l — (l is an integer of 1 to 10), —C (CH ₃ ) At least one structure selected from the group consisting of _2- .

R ¹¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, and — (CF ₂ ) _p —. (P represents an integer of 1 to 12).

R ¹² and R ¹³ are each independently at least one structure selected from the group consisting of a hydrogen atom, an alkali metal atom, an aliphatic hydrocarbon group, an alicyclic group, or a hydrocarbon group containing a heterocyclic ring containing oxygen. Indicates. However, at least one of all R ¹² and R ¹³ included in the above formula is a hydrogen atom.

x ¹ is an integer from 0 to 4. x ² is an integer of 1 to 5. a is an integer of 0 to 1. b, b1 and b2 each represents an integer of 0 to 3.

The monomer represented by the above formula (3-3) preferably has a structure represented by the following formula (3-4).

[In the above formula (3-4), X represents at least one structure selected from the group consisting of chlorine, bromine, iodine, methanesulfonyl group, trifluoromethanesulfonyl group, and benzenesulfonyl group.
Y is a direct bond, —CO—, —SO ₂ —, —SO—, —CONH—, —COO—, — (CF ₂ ) _l — (l is an integer of 1 to 10), —C (CF ₃ ) represents at least one structure selected from the group consisting of ₂ —, Z is a direct bond, or — (CH ₂ ) ₁ — (l is an integer of 1 to 10), —C (CH ₃ ) ₂ represents at least one structure selected from the group consisting of —O—, —S—, —CO—, —SO ₂ —, —SO—, and Ar represents —SO ₃ H or —O (CH ₂ ) an aromatic group having a _p SO ₃ H or -O _{(CF 2)} p SO ₃ substituent represented by H. p represents an integer of 1 to 12, m represents an integer of 0 to 10, n represents an integer of 0 to 10, and k represents an integer of 1 to 4. ]
The sulfonic acid in the above formula may be a sulfonic acid ester. Examples of the ester include alkyl esters, aryl esters, cycloalkyl (which may be fluorine-substituted), and the like.

Specific examples of the compounds represented by the general formulas (3-3) and (3-4) include compounds represented by the following, JP-A Nos. 2004-137444, 2004-345997, and Examples thereof include sulfonic acid esters described in Kaikai 2004-346163.

 

 

Of these, preferred are compounds in which the protecting group is neopentyl alcohol, isopropyl alcohol, or furfuryl alcohol.

In addition, a compound in which a chlorine atom is replaced with a bromine atom in the above compound, a compound in which —CO— is replaced with —SO ₂ —, and the like are also included. In addition, isomers having different bonding positions of chlorine atoms and bromine atoms can also be mentioned.
(3) Method for Producing Structural Unit Having Aromatic Structure A structural unit having an aromatic structure is derived from a monomer comprising the following formula (4-2).

(In the formula (4-2), Ar ²¹ , Ar ²² , Ar ²³ , Ar ²⁴ are at least one structure selected from the group consisting of a benzene ring, a condensed aromatic ring (such as a naphthalene ring), and a nitrogen-containing heterocyclic ring. However, Ar ²¹ , Ar ²² , Ar ²³ , Ar ²⁴ are each a hydrogen atom, a fluorine atom, an alkyl group, a halogenated alkyl group in which a part or all of them are fluorine-substituted, an allyl group, an aryl group, It may be substituted with a nitro group or a nitrile group.

X represents at least one structure selected from the group consisting of chlorine, bromine, iodine, methanesulfonyl group, trifluoromethanesulfonyl group, benzenesulfonyl group, and toluenesulfonyl group.

A and D are independently a direct bond, or —CO—, —COO—, —CONH—, —SO ₂ —, —SO—, — (CF ₂ ) _l — (l is an integer of 1 to 10), — (CH ₂ ) ₁ — (wherein 1 is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group and a halogenated hydrocarbon group), cyclohexene Represents at least one structure selected from the group consisting of a silidene group, a fluorenylidene group, —O—, and —S—, B is independently an oxygen atom or a sulfur atom, and s and t are 0-4 An integer is shown, and r is 0 or an integer of 1 or more. )
The structural unit having an aromatic structure can be obtained by using, for example, an oligomer represented by the following general formula (4-3) as a polymerization raw material for a polyarylene-based copolymer.

[In the above formula (4-3), X represents at least one structure selected from the group consisting of chlorine, bromine, iodine, methanesulfonyl group, trifluoromethanesulfonyl group, and benzenesulfonyl group.
A and D are independently a direct bond, or —CO—, —SO ₂ —, —SO—, — (CF ₂ ) ₁ — (l is an integer of 1 to 10), — (CH ₂ ) ₁ — ( l is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group and a halogenated hydrocarbon group), a cyclohexylidene group, a fluorenylidene group, — At least one structure selected from the group consisting of O— and —S—;
B is independently an oxygen atom or a sulfur atom,
R ¹ to R ¹⁶ may be the same as or different from each other, and may be a hydrogen atom, a fluorine atom, an alkyl group, a halogenated alkyl group in which some or all are halogenated, an allyl group, an aryl group, a nitro group, a nitrile group. At least one atom or group selected from the group consisting of
s and t are integers of 0 to 4, and r is 0 or an integer of 1 or more. ]
Specific examples of the oligomer represented by the above formula (4-3) include the following.

In addition, a compound in which a chlorine atom is replaced with a bromine atom in the above compound is also included. In addition, isomers having different bonding positions of chlorine atoms and bromine atoms can also be mentioned.

The oligomers represented by the above formulas (4-2) and (4-3) can be produced, for example, by copolymerizing the following monomers. When r = 0 in the formulas (4-2) and (4-3), for example, 4,4′-dichlorobenzophenone, 4,4′-dichlorobenzanilide, 2,2-bis (4-chlorophenyl) difluoromethane, 2,2-bis (4-chlorophenyl) -1,1,1,3,3,3-hexafluoropropane, 4-chlorobenzoic acid-4-chlorophenyl ester, bis (4-chlorophenyl) sulfoxide, bis (4- Chlorophenyl) sulfone and 2,6-dichlorobenzonitrile.

These compounds include compounds in which chlorine atoms are replaced by bromine atoms or iodine atoms. In the case of r = 1, for example, compounds described in JP-A No. 2003-113136 can be exemplified.

In the case of r ≧ 2, for example, Japanese Patent Application Laid-Open No. 2004-137444, Japanese Patent Application Laid-Open No. 2004-244517, Japanese Patent Application No. 2003-143914 (Japanese Patent Application Laid-Open No. 2004-346164), Japanese Patent Application No. 2003-348523 (Japanese Patent Application Laid-Open No. 2005-348523). No. 112985), Japanese Patent Application No. 2003-348524, Japanese Patent Application No. 2004-211739 (Japanese Patent Laid-Open No. 2006-28414), Japanese Patent Application No. 2004-21740 (Japanese Patent Laid-Open No. 2006-28415), and the like. Can do.
(4) Polymerization of polyarylene-based copolymer In order to obtain the desired polyarylene-based copolymer, first, the above general formulas (1-1) and (1) which can be structural units represented by the above general formula (1) The monomer represented by 1-2), the monomer represented by the general formula (3-3) or (3-4) that can be the structural unit represented by the general formula (3), and the general formula (4) It is necessary to copolymerize a monomer or oligomer precursor that can be a structural unit represented by formula (II), that is, a general formula (4-2) or (4-3) to obtain a precursor polyarylene. This copolymerization is carried out in the presence of a catalyst, and the catalyst used in this case is a catalyst system containing a transition metal compound. This catalyst system is (1) a transition metal salt and a ligand. A compound (hereinafter referred to as “ligand component”) or a transition metal complex coordinated with a ligand (including a copper salt) and (2) a reducing agent as essential components, and further increase the polymerization rate. Therefore, salts other than transition metal salts may be added.

Here, transition metal salts include nickel compounds such as nickel chloride, nickel bromide, nickel iodide and nickel acetylacetonate, palladium compounds such as palladium chloride, palladium bromide and palladium iodide, iron chloride and iron bromide. And iron compounds such as iron iodide and cobalt compounds such as cobalt chloride, cobalt bromide and cobalt iodide. Of these, nickel chloride, nickel bromide and the like are particularly preferable. Examples of the ligand include triphenylphosphine, tri (2-methyl) phenylphosphine, tri (3-methyl) phenylphosphine, tri (4-methyl) phenylphosphine, 2,2′-bipyridine, 1,5- Examples include cyclooctadiene and 1,3-bis (diphenylphosphino) propane. Triphenylphosphine, tri (2-methyl) phenylphosphine, and 2,2′-bipyridine are preferred. The said ligand can be used individually by 1 type or in combination of 2 or more types.

Furthermore, as the transition metal (salt) in which the ligand is coordinated in advance, for example, nickel chloride bis (triphenylphosphine), nickel chloride bis (tri (2-methyl) phenylphosphine), nickel bromide bis (triphenyl) Phosphine), nickel iodide bis (triphenylphosphine), nickel nitrate bis (triphenylphosphine), nickel chloride (2,2′bipyridine), nickel bromide (2,2′bipyridine), nickel iodide (2,2) 'Bipyridine), nickel nitrate (2,2'bipyridine), bis (1,5-cyclooctadiene) nickel, tetrakis (triphenylphosphine) nickel, tetrakis (triphenylphosphite) nickel, tetrakis (triphenylphosphine) palladium Nikke chloride Bis (triphenylphosphine), nickel chloride bis (tri (2 Mechiru) phenyl phosphine), nickel chloride (2,2'-bipyridine) are preferred.

Examples of the reducing agent that can be used in the catalyst system of the present invention include iron, zinc, manganese, aluminum, magnesium, sodium, and calcium, and zinc, magnesium, and manganese are preferable. These reducing agents can be used after being more activated by bringing them into contact with an acid such as an organic acid.

Examples of salts other than transition metal salts that can be used in the catalyst system of the present invention include sodium compounds such as sodium fluoride, sodium chloride, sodium bromide, sodium iodide, sodium sulfate, potassium fluoride, and potassium chloride. Potassium compounds such as potassium bromide, potassium iodide, and potassium sulfate, and ammonium compounds such as tetraethylammonium fluoride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, and tetraethylammonium sulfate. Sodium, sodium iodide, potassium bromide, tetraethylammonium bromide and tetraethylammonium iodide are preferred.

The proportion of each component used in the catalyst system is such that the transition metal salt or the transition metal (salt) coordinated with the ligand can be a structural unit represented by the general formula (1). ) Or (1-2); a monomer represented by general formula (3-3) or (3-4) that can be a structural unit represented by general formula (3); Usually 0.0001 to 10 moles, preferably 1 mole to a total of 1 mole of the monomer or oligomer precursor that can be the structural unit represented by the formula (4), that is, the general formula (4-2) or (4-3) Is 0.01 to 0.5 mol. If it is in this range, the polymerization reaction is sufficiently promoted, the catalytic activity is high, and the molecular weight can be increased. When the amount is less than the above range, the polymerization reaction does not proceed sufficiently. On the other hand, when the amount is too large, the molecular weight is lowered. When a transition metal salt and a ligand are used in the catalyst system, the amount of the ligand used is usually 0.1 to 100 mol, preferably 1 to 10 mol, per 1 mol of the transition metal salt. If the amount is less than 0.1 mol, the catalytic activity becomes insufficient. On the other hand, if the amount exceeds 100 mol, the molecular weight decreases.

The ratio of the reducing agent used in the catalyst system is such that the monomer represented by the general formula (1-1) or (1-2) that can be the structural unit represented by the general formula (1) and the general formula A monomer represented by the general formula (3-3) or (3-4) that can be a structural unit represented by (3), a monomer that can be a structural unit represented by the above general formula (4), or an oligomer The amount is usually 0.1 to 100 mol, preferably 1 to 10 mol, per 1 mol of the total amount of the precursor, that is, the general formula (4-2) or (4-3). If it exists in this range, superposition | polymerization will fully advance and a polymer can be obtained with a high yield. Further, when the lower limit of the above range is satisfied, the polymerization does not proceed sufficiently. On the other hand, when the upper limit is exceeded, there is a problem that it is difficult to purify the resulting polymer.

Further, when a salt other than a transition metal salt is used in the catalyst system, the proportion used is the above general formula (1-1) or (1-2) that can be the structural unit represented by the general formula (1). A monomer represented by the general formula (3-3) or (3-4) that can be a structural unit represented by the general formula (3), and a general formula (4). The amount of the monomer or oligomer precursor that can be a structural unit, that is, 0.001 to 100 mol, preferably 0.01 to 1 mol, relative to the total of 1 mol of the general formula (4-2) or (4-3) is there. When the amount is less than 0.001 mol, the effect of increasing the polymerization rate is insufficient. On the other hand, when the amount exceeds 100 mol, there is a problem that it is difficult to purify the resulting polymer.

Examples of the polymerization solvent that can be used in the present invention include tetrahydrofuran, cyclohexanone, dimethyl sulfoxide, N, N-dimethylformamide, N, N-dimethylacetamide, 1-methyl-2-pyrrolidone, γ-butyrolactone, γ- Examples include butyrolactam, and tetrahydrofuran, N, N-dimethylformamide, N, N-dimethylacetamide, and 1-methyl-2-pyrrolidone are preferable. These polymerization solvents are preferably used after sufficiently dried. A monomer represented by the above general formula (1-1) or (1-2) which can be a structural unit represented by the above general formula (1) in a polymerization solvent; and the above general formula (3) or (3-1) The monomer represented by the general formula (3-3) or (3-4) that can be a structural unit represented by formula (3), and the monomer or oligomer precursor that can be the structural unit represented by the general formula (4). That is, the total concentration of the general formula (4-2) or (4-3) is usually 1 to 90% by weight, preferably 5 to 40% by weight.

The polymerization temperature for polymerizing the polymer of the present invention is usually 0 to 200 ° C., preferably 50 to 80 ° C. The polymerization time is usually 0.5 to 100 hours, preferably 1 to 40 hours.

In the production method described above, the phosphonic acid ester group and the sulfonic acid ester group contained in the obtained copolymer are converted into phosphonic acid groups (—P═O (OH) ₂ ) and sulfonic acid groups (—SO ₃ H). ).

In particular,
(1) A method in which the polyarylene is added to an excess amount of water or alcohol containing a small amount of hydrochloric acid and stirred for 5 minutes or longer. (2) The polyarylene is heated at a temperature of about 80 to 120 ° C. in trifluoroacetic acid. (3) A solution containing 1 to 9 moles of lithium bromide per mole of sulfonate group (—SO ₃ R) and phosphonate group in polyarylene, for example, N-methyl Examples thereof include a method of reacting the polyarylene in a solution such as pyrrolidone at a temperature of about 80 to 150 ° C. for about 3 to 10 hours and then adding hydrochloric acid.

In the case of a phosphonate group, it can be deionized to a phosphonate group by a method such as an ion exchange resin.

When directly introducing a sulfonated or alkylsulfonic acid group as in the methods B1 and C1 described later, the phosphonate ester group or phosphonate group is hydrolyzed or ion-exchanged in advance by the method as described above. Alternatively, after introducing a sulfonic acid group, a phosphonic acid ester group or a phosphonic acid group may be hydrolyzed or ion-exchanged.
(B1 method)
For example, the phosphonic acid compound represented by the above general formula (1-1) or (1-2) and the above general formula (3) or (3-1) by the method described in JP-A-2001-342241 And a monomer that can be a structural unit represented by the general formula (4), or an oligomer, that is, a general formula (4-2) or (4-3) can be copolymerized and the polymer can be synthesized by sulfonation using a sulfonating agent.
(C1 method)
In the general formula (3) or (3-1), Ar is an aromatic group having a substituent represented by —O (CH ₂ ) _p SO ₃ H or —O (CF ₂ ) _p SO ₃ H For example, in the method described in Japanese Patent Application No. 2003-295974 (Japanese Patent Application Laid-Open No. 2005-60625), the phosphonic acid compound represented by the above general formula (1-1) or (1-2) and the above A precursor monomer that can be a structural unit represented by the general formula (3) or (3-1) is copolymerized with a monomer or oligomer that can be a structural unit represented by the general formula (4). It can also be synthesized by a method of introducing alkylsulfonic acid or fluorine-substituted alkylsulfonic acid into

In the case of direct sulfonation (Method B1), a precursor polyarylene having no sulfonic acid group or sulfonic acid ester group is converted into a known sulfone such as sulfuric anhydride, fuming sulfuric acid, chlorosulfonic acid, sulfuric acid, sodium hydrogen sulfite and the like. It can be sulfonated under known conditions using a polymerizing agent [Polymer Preprints, Japan, Vol. 42, no. 3, p. 730 (1993); Polymer Preprints, Japan, Vol. 42, no. 3, p. 736 (1994); Polymer Preprints, Japan, Vol. 42, no. 7, p. 2490-2492 (1993)]. That is, as the sulfonation reaction conditions, a precursor polyarylene having no sulfonic acid group or sulfonic acid ester group is reacted with the sulfonating agent in the absence of a solvent or in the presence of a solvent.
Examples of the solvent include hydrocarbon solvents such as n-hexane, ether solvents such as tetrahydrofuran and dioxane, aprotic polar solvents such as dimethylacetamide, dimethylformamide, and dimethylsulfoxide, tetrachloroethane, dichloroethane, chloroform, and chloride. And halogenated hydrocarbons such as methylene. The reaction temperature is not particularly limited, but is usually −50 to 200 ° C., preferably −10 to 100 ° C. The reaction time is usually 0.5 to 1,000 hours, preferably 1 to 200 hours.

(Method C1) includes a phosphonic acid compound represented by the general formula (1-1) or (1-2) and a sulfone having a skeleton represented by the general formula (3) or (3-1). A monomer having no acid group or sulfonic acid ester group and having an OH group or SH at the terminal (the following formulas (3′a), (3′b), (3′-1)), and the above general formula After copolymerizing the monomer or oligomer that can be the structural unit represented by (4), that is, the general formula (4-2) or (4-3), the OH group and the SH group are changed to an —OM group or — After substitution with an SM group (M represents a hydrogen atom or an alkali metal atom), the compound represented by the following general formula (5) or (6) can be sulfonated by reacting under an alkaline condition. .

In the formulas (3′a), (3′b), and (3′-1), X represents a halogen atom, and Ar ″ represents an aromatic group having an OH or SH group.

In the formulas (5) and (6), R ⁴⁰ represents at least one atom or group selected from the group consisting of a hydrogen atom, a fluorine atom, an alkyl group, and a fluorine-substituted alkyl group, and g is an integer of 1 to 20 Indicates.

In formula (6), L represents any of a chlorine atom, a bromine atom, and an iodine atom, and M represents a hydrogen atom or an alkali metal atom.

The molecular weight of the polymer of the present invention is 10,000 to 1,000,000, preferably 20,000 to 800,000, and more preferably 50,000 to 300,000 in terms of polystyrene-equivalent weight average molecular weight by gel permeation chromatography (GPC).

The ion exchange capacity of the polymer according to the present invention is usually 0.3 to 5 meq / g, preferably 0.5 to 3 meq / g, more preferably 0.8 to 2.8 meq / g. When the ion exchange capacity is 0.3 meq / g or more, the proton conductivity is high and the power generation performance can be improved. On the other hand, if it is 5 meq / g or less, it can have sufficiently high water resistance.

The above-mentioned ion exchange capacity can be adjusted by changing the type, usage ratio, and combination of each structural unit. Therefore, it can be adjusted by changing the charge amount ratio and type of the precursor (monomer / oligomer) that induces the structural unit during polymerization.

In general, as the number of structural units containing sulfonic acid groups and phosphonic acid groups increases, the ion exchange capacity increases and proton conductivity increases, but the water resistance tends to decrease. On the other hand, when these structural units decrease, ion exchange increases. The capacity decreases and the water resistance increases, but the proton conductivity tends to decrease. Moreover, when the amount of phosphonic acid groups increases, radical resistance tends to increase.
[Method of manufacturing electrolyte membrane]
The polyarylene-based copolymer of the present invention comprises the above-mentioned copolymer, and includes primary battery electrolytes, secondary battery electrolytes, polymer solid electrolytes for fuel cells, display elements, various sensors, signal transmission media, and solid capacitors. When used for an ion exchange membrane or the like, it can be used in a membrane state, a solution state, or a powder state, and among these, a membrane state and a solution state are preferable (hereinafter, the membrane state is referred to as a polymer electrolyte membrane). .

The polymer electrolyte membrane of the present invention can be produced by a casting method or the like in which the polyarylene copolymer is mixed in an organic solvent and cast on a substrate to form a film. Here, the substrate is not particularly limited as long as it is a substrate used in a normal solution casting method. For example, a substrate made of plastic, metal, or the like is used, and preferably a heat treatment such as a polyethylene terephthalate (PET) film. A substrate made of a plastic resin is used.

The solvent for mixing the polyarylene copolymer may be any solvent that dissolves the copolymer or a solvent that swells, such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, and γ-butyrolactone. , N, N-dimethylacetamide, dimethylsulfoxide, dimethylurea, dimethylimidazolidinone, acetonitrile, and other aprotic polar solvents, dichloromethane, chloroform, 1,2-dichloroethane, chlorobenzene, dichlorobenzene and other chlorinated solvents, methanol , Ethanol, propanol, iso-propyl alcohol, sec-butyl alcohol, tert-butyl alcohol and other alcohols, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol Alkylene glycol monoalkyl ethers Roh ethyl ether, acetone, methyl ethyl ketone, cyclohexanone, ketones such as γ- butyrolactone, tetrahydrofuran, solvents such as ethers 1,3-dioxane and the like. These solvents can be used alone or in combination of two or more. In particular, from the viewpoint of solubility and solution viscosity, N-methyl-2-pyrrolidone (hereinafter also referred to as “NMP”) is preferable.

When a mixture of an aprotic polar solvent and another solvent is used as the solvent, the composition of the mixture is 95-25% by weight of the aprotic polar solvent, preferably 90-25% by weight, The solvent is 5 to 75% by weight, preferably 10 to 75% by weight (however, the total is 100% by weight). When the amount of the other solvent is within the above range, the effect of lowering the solution viscosity is excellent. In this case, the combination of the aprotic polar solvent and the other solvent is preferably NMP as the aprotic polar solvent and methanol having an effect of lowering the solution viscosity in a wide composition range as the other solvent.

The polymer concentration of the solution in which the copolymer and the additive are dissolved depends on the molecular weight of the sulfonic acid-containing polyarylene copolymer, but is usually 5 to 40% by weight, preferably 7 to 25% by weight. is there. If it is less than 5% by weight, it is difficult to form a thick film, and pinholes are easily generated. On the other hand, if it exceeds 40% by weight, the solution viscosity is so high that it is difficult to form a film, and surface smoothness may be lacking.

The solution viscosity is usually from 2,000 to 100,000 mPa · s, preferably from 3,000 to 50, although it depends on the molecular weight of the polyarylene copolymer, the polymer concentration, and the concentration of the additive. 000 mPa · s. If it is less than 2,000 mPa · s, the retention of the solution during film formation is poor, and it may flow from the substrate. On the other hand, if it exceeds 100,000 mPa · s, the viscosity is too high to be extruded from the die, and it may be difficult to form a film by the casting method.

After film formation as described above, when the obtained undried film is immersed in water, the organic solvent in the undried film can be replaced with water, and the amount of residual solvent in the resulting polymer electrolyte membrane is reduced. can do.

Note that after the film formation, the undried film may be preliminarily dried before the undried film is immersed in water. The preliminary drying is performed by holding the undried film at a temperature of usually 50 to 150 ° C. for 0.1 to 10 hours.

When the undried film is immersed in water and dried as described above, a film with a reduced amount of residual solvent is obtained. The residual solvent amount of the film thus obtained is usually 5% by weight or less. Further, depending on the dipping conditions, the amount of residual solvent in the obtained film can be set to 1% by weight or less.
As such conditions, for example, the amount of water used is 50 parts by weight or more with respect to 1 part by weight of the undried film, the temperature of the water during immersion is 10 to 60 ° C., and the immersion time is 10 minutes to 10 hours. is there.

After immersing the undried film in water as described above, the film is dried at 30-100 ° C., preferably 50-80 ° C., for 10-180 minutes, preferably 15-60 minutes, and then at 50-150 ° C. The film can be obtained by vacuum drying under reduced pressure of 500 mmHg to 0.1 mmHg for 0.5 to 24 hours.

The polymer electrolyte membrane obtained by the method of the present invention has a dry film thickness of usually 10 to 100 μm, preferably 20 to 80 μm.

In addition, after the polyarylene copolymer having the phosphonic acid or sulfonic acid ester group or the alkali metal salt of phosphonic acid or sulfonic acid is formed into a film by the method as described above, it is suitable for hydrolysis, acid treatment, etc. The polymer electrolyte membrane according to the present invention can also be produced by performing an after-treatment. Specifically, a polyarylene copolymer having an alkali metal salt of phosphonic acid or sulfonic acid is formed into a film by the method described above, and then the polyarylene is hydrolyzed or acid-treated. A polymer electrolyte membrane made of a copolymer can be produced.

In addition, when producing a polymer electrolyte membrane, in addition to the polyarylene copolymer, inorganic acids such as sulfuric acid and phosphoric acid, phosphoric acid glass, tungstic acid, phosphate hydrate, β-alumina proton substitution product, Inorganic proton conductor particles such as proton-introduced oxides, organic acids containing carboxylic acids, organic acids containing sulfonic acids, organic acids containing phosphonic acids, appropriate amounts of water, etc. may be used in combination.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples. In Examples, “%” means “% by weight” unless otherwise specified.
[Preparation of electrolyte membrane for evaluation]
The copolymer obtained in each Example / Comparative Example was dissolved in an N-methylpyrrolidone / methanol solution, then cast on a PET substrate using an applicator, and 60 ° C. × 30 minutes, 80 ° C. using an oven. × 40 minutes, 120 ° C. × 60 minutes. The dried membrane was immersed in deionized water. After immersion, a film for evaluation was obtained by drying at 50 ° C. for 45 minutes.
[Molecular weight]
The copolymer obtained in each Example / Comparative Example was dissolved in an N-methylpyrrolidone buffer solution (hereinafter referred to as NMP buffer solution) and subjected to gel permeation chromatography (GPC) to obtain a number average molecular weight in terms of polystyrene ( Mn) and weight average molecular weight (Mw) were determined. The NMP buffer solution was adjusted at a ratio of NMP (3 L) / phosphoric acid (3.3 mL) / lithium bromide (7.83 g).
[Ratio of the amount of phosphonic acid groups and sulfonic acid groups]
This is the ratio of the amount of phosphonic acid groups and the amount of sulfonic acid groups present in the entire raw material used for the polymerization reaction of the polyarylene copolymer.
[Measurement of ion exchange capacity]
The obtained polyarylene copolymer is washed until the washing water has a pH of 4 to 6, the free remaining acid is removed, washed thoroughly, dried, weighed in a predetermined amount, and THF / The sample was dissolved in a mixed solvent of water, titrated with a standard solution of NaOH using phenolphthalein as an indicator, and the ion exchange capacity was determined from the neutralization point.
[Measurement of proton conductivity]
The AC resistance was obtained by pressing a platinum wire (f = 0.5 mm) on the surface of a strip-shaped sample film having a width of 5 mm, holding the sample in a constant temperature and humidity device, and measuring AC impedance between the platinum wires. . That is, the impedance at AC 10 kHz was measured in an environment of 85 ° C. and relative humidity 90%. A chemical impedance measurement system manufactured by NF Circuit Design Block Co., Ltd. was used as the resistance measurement device, and JW241 manufactured by Yamato Scientific Co., Ltd. was used as the constant temperature and humidity device.
Five platinum wires were pressed at intervals of 5 mm, the distance between the wires was changed to 5 to 20 mm, and the AC resistance was measured. The specific resistance of the membrane was calculated from the line-to-line distance and the resistance gradient, and the proton conductivity was calculated from the reciprocal of the specific resistance.

Specific resistance R (Ω · cm) = 0.5 (cm) × film thickness (cm) × resistance-to-resistance gradient (Ω / cm)
[Fenton test]
A Fenton reagent was prepared by adding iron sulfate heptahydrate to 3% by weight of hydrogen peroxide so that the concentration of iron ions was 5 ppm. 50 g of Fenton reagent was collected in a 50 ml glass sample tube, a polymer electrolyte membrane cut to 2 cm × 3 cm was added, and after sealing, immersed in a constant temperature water bath at 45 ° C., a 24-hour Fenton test was performed. After the Fenton test, the film was taken out, washed with ion-exchanged water, and allowed to stand at 25 ° C. and a relative humidity of 50% for 12 hours, and the weight retention and ion exchange capacity retention before and after the Fenton test were measured. The weight retention in the Fenton test was calculated by the following mathematical formula.
Weight retention (%) in Fenton test = film weight after Fenton test / film weight before Fenton test × 100
Ion exchange capacity retention rate (%) in Fenton test = ion exchange capacity after Fenton test / ion exchange capacity before Fenton test × 100
[Hot water test: How to determine swelling shrinkage]
The film was cut into 2.0 cm × 3.0 cm and weighed to obtain a test piece for testing. After conditioning under conditions of 24 ° C. and 50% relative humidity (RH), the film is put into a 250 ml polycarbonate bottle, about 100 ml of distilled water is added thereto, and a pressure cooker tester (manufactured by HIRAYAMA MFS CORP) is used. And PC-242HS) for 24 hours. After completion of the test, each film was taken out from the hot water, the surface water was gently wiped off with Kimwipe, the dimensions were measured, and the swelling rate was determined. The film was conditioned at 24 ° C. and RH 50%, water was distilled off, and the dimensions of the film after the hot water test were measured to determine the shrinkage. The amount of expansion and contraction was determined according to the following formula.
Swelling ratio = (size of 2 cm side when containing water / 2 + size of 3 cm side when containing water / 3) × 100/2
Shrinkage rate = (size of 2 cm side when dried / size of 2 cm side when dried / 3) × 100/2
In-plane dimensional change rate = (swelling rate−100) + (100−shrinkage rate)
<Synthesis Example 1 of a structural unit having a phosphonic acid group>
In a 2 L three-necked flask equipped with a stirring blade, a thermometer, and a nitrogen introduction tube, 134.0 g (0.91 mol) of 1,4-dichlorobenzene, 100.0 g (0.46 mol) of 3-bromobenzoyl chloride, 121 aluminum chloride 121 0.5 g (0.91 mol) was taken and stirred at 135 ° C. for 4 hours. After completion of the reaction, the reaction solution was dropped into ice water and extracted from toluene. The mixture was neutralized with 1% aqueous sodium hydrogen carbonate solution, washed with saturated brine, and concentrated. The following formula (30-1) was obtained by recrystallization from hexane. The yield was 96.1 g.

In a 1 L three-necked flask equipped with a stirring blade, a thermometer, and a nitrogen inlet tube, 33.0 g (0.1 mol) of (30-1), 15.2 g (0.11 mol) of diethyl phosphite, tetrakis (triphenylphosphine) Fino) 5.78 g (5 mmol) of palladium and 11.13 g (0.11 mol) of triethylamine were taken and stirred at 80 ° C. for 3 hours. After completion of the reaction, the precipitated salt was removed by filtration, and the solvent was concentrated. Purification was performed by silica gel column chromatography using toluene / ethyl acetate as a developing solvent to obtain the following formula (30-2). The yield was 18.5 g.

<Synthesis Example 2 of a structural unit having a phosphonic acid group>
(30-1) 33.0 g (0.1 mol), 2-hydroxy-1,3,2-dioxaphosphorinan (13.43 g) in a 1 L three-necked flask equipped with a stirring blade, thermometer, and nitrogen introduction tube (0.11 mol), 5.78 g (5 mmol) of tetrakis (triphenylphosphino) palladium and 11.13 g (0.11 mol) of triethylamine were taken and stirred at 80 ° C. for 3 hours. After completion of the reaction, the precipitated salt was removed by filtration, and the solvent was concentrated. Purification by recrystallization from toluene gave the following formula (30-3). Yield 20.4g.

<Synthesis Example 3 of a structural unit having a phosphonic acid group>

Take 32.4 g (0.2 mol) of 3,5-dichloroaniline in a 1 L four-necked flask equipped with a stirring blade, thermometer, and nitrogen inlet tube, and disperse in 125 mL of concentrated hydrochloric acid and 125 mL of water. Cooled down. An aqueous solution in which 13.8 g (0.2 mol) of sodium nitrite was dissolved in 80 mL of water was dropped while maintaining the temperature at −5 ° C. or lower. After completion of the dropping, stirring was continued at −5 ° C. or lower for 30 minutes, and the mixture was added dropwise at 0 ° C. to an aqueous solution in which 60 g (0.4 mol) of sodium iodide was dissolved in 100 mL of water. After gas evolution ceased, the reaction solution was diluted with water. Sodium sulfite was added until the dark coloration due to free iodine disappeared. Purification by steam distillation and recrystallization from ethanol gave 29.5 g of colorless crystals of 1-iodo-3,5-dichlorobenzene, which was the target product.

In a 500 mL three-necked flask equipped with a stirring blade, a thermometer, and a nitrogen introduction tube, 27.29 g (0.10 mol) of 1-iodo-3,5-dichlorobenzene obtained above, 2-hydroxy-1,3 , 2-dioxaphosphorinane 13.43 g (0.11 mol), tetrakis (triphenylphosphino) palladium 5.78 g (5 mmol), triethylamine 11.13 g (0.11 mol), toluene 150 mL were taken at 80 ° C. Stir for 5 hours. After completion of the reaction, the precipitated salt was removed by filtration, and the solvent was concentrated. Purification was performed by recrystallization from toluene to obtain a compound represented by the above formula (30-12), which was the target product. The yield was 20.3g.

<Synthesis Example 4 of a structural unit having a phosphonic acid group>

In a 500 mL three-necked flask equipped with a stirring blade, a thermometer, and a nitrogen inlet tube, 22.59 g (0.10 mol) of 1-bromo-2,5-dichlorobenzene, 2-hydroxy-1,3,2-dioxa Phosphorinan (13.43 g, 0.11 mol), tetrakis (triphenylphosphino) palladium (5.78 g, 5 mmol), triethylamine (11.13 g, 0.11 mol), and toluene (150 mL) were taken and stirred at 80 ° C. for 5 hours. After completion of the reaction, the precipitated salt was removed by filtration, and the solvent was concentrated. Purification was carried out by recrystallization from toluene to obtain the compound represented by the above formula (30-13) as the target product. The yield was 19.2g.
<Synthesis of a structural unit having a sulfonic acid group>
To a 3 L three-necked flask equipped with a stirrer and a condenser, chlorosulfonic acid (233.0 g, 2 mol) was added, followed by 2,5-dichlorobenzophenone (30-4) (100.4 g, 400 mmol), and 100 The reaction was carried out in an oil bath at 0 ° C. for 8 hours. After a predetermined time, the reaction solution was slowly poured onto crushed ice (1000 g) and extracted with ethyl acetate. The organic layer was washed with brine and dried over magnesium sulfate, and then ethyl acetate was distilled off to obtain pale yellow crude crystals (3- (2,5-dichlorobenzoyl) benzenesulfonic acid chloride) (30-5). . The crude crystals were used in the next step without purification.

2,2-dimethyl-1-propanol (neopentyl alcohol) (38.8 g, 440 mmol) was added to 300 ml of pyridine and cooled to about 10 ° C. The crude crystals obtained above were gradually added thereto over about 30 minutes. After the total amount was added, the reaction was further stirred for 30 minutes. After the reaction, the reaction solution was poured into 1000 ml of aqueous hydrochloric acid, and the precipitated solid was collected. The obtained solid was dissolved in ethyl acetate, washed with aqueous sodium hydrogen carbonate solution and brine, dried over magnesium sulfate, and then ethyl acetate was distilled off to obtain crude crystals. This was recrystallized from methanol to obtain white crystals of neopentyl 3- (2,5-dichlorobenzoyl) benzenesulfonate (30-6) as a target product.

<Synthesis 1 of a structural unit having an aromatic structure>
To a 1 L three-necked flask equipped with a stirrer, thermometer, cooling tube, Dean-Stark tube, and three-way cock with nitrogen introduction, 2,2-bis (4-hydroxyphenyl) -1,1,1,3 , 3,3-hexafluoropropane 67.3 g (0.20 mol), 4,4′-dichlorobenzophenone (4,4′-DCBP) 60.3 g (0.24 mol), potassium carbonate 71.9 g (0.52 mol) ), 300 mL of N, N-dimethylacetamide (DMAc) and 150 mL of toluene were taken, heated in an oil bath under a nitrogen atmosphere, and reacted at 130 ° C. with stirring. When water produced by the reaction was azeotroped with toluene and reacted while being removed out of the system with a Dean-Stark tube, almost no water was observed in about 3 hours. The reaction temperature was gradually increased from 130 ° C to 150 ° C. Thereafter, most of the toluene was removed while gradually raising the reaction temperature to 150 ° C., and the reaction was continued at 150 ° C. for 10 hours. Then, 10.0 g (0.040 mol) of 4,4′-DCBP was added, and another 5 hours Reacted. The resulting reaction solution was allowed to cool, and then the by-product inorganic compound precipitate was removed by filtration, and the filtrate was put into 4 L of methanol. The precipitated product was separated by filtration, collected, dried, and dissolved in 300 mL of tetrahydrofuran. This was reprecipitated in 4 L of methanol to obtain 95 g (yield 85%) of the target compound.

The polystyrene-converted Mn obtained by GPC (THF solvent) of the obtained copolymer was 11,200. The resulting compound was an oligomer represented by the formula (30-7).

<Synthesis 2 of a structural unit having an aromatic structure>
To a 1 L three-necked flask equipped with a stirrer, thermometer, Dean-stark tube, nitrogen inlet tube, and condenser tube, 154.8 g (0.9 mol) of 2,6-dichlorobenzonitrile and 2,2-bis (4-hydroxy) were added. Phenyl) -1,1,1,3,3,3-hexafluoropropane (269.0 g, 0.8 mol) and potassium carbonate (143.7 g, 1.04 mol) were weighed. After substitution with nitrogen, 1020 mL of sulfolane and 510 mL of toluene were added and stirred.
The reaction solution was heated to reflux at 150 ° C. in an oil bath. Water produced by the reaction was trapped in a Dean-stark tube. After 3 hours, when almost no water was observed, toluene was removed from the Dean-stark tube out of the system. The reaction temperature was gradually raised to 200 ° C. and stirring was continued for 3 hours. Then, 51.6 g (0.3 mol) of 2,6-dichlorobenzonitrile was added, and the reaction was further continued for 5 hours.

The reaction solution was allowed to cool and then diluted by adding 250 mL of toluene. Inorganic salts insoluble in the reaction solution were filtered, and the filtrate was poured into 8 L of methanol to precipitate the product. The precipitated product was filtered and dried, then dissolved in 500 mL of tetrahydrofuran, and poured into 5 L of methanol for reprecipitation. The precipitated white powder was filtered and dried to obtain 258 g of the desired product. Mn measured by GPC was 7,500. It was confirmed that the obtained compound was an oligomer represented by formula (30-8).

Example 1
Synthesis by 6.13 g (16 mmol) of the compound represented by the above general formula (30-2), 31.75 g (79 mmol) of the compound represented by the above general formula (30-6) and the above formula (30-7) Hydrophobic unit 12.32 g (1 mmol), bis (triphenylphosphine) nickel dichloride 1.96 g (3.0 mmol), triphenylphosphine 10.49 g (40 mmol), sodium iodide 0.45 g (3.0 mmol), 166 mL of dried DMAc in a mixture of 15.69 g (240 mmol) of zinc was added under nitrogen.

The reaction system was heated with stirring (finally heated to 79 ° C.) and reacted for 3 hours. An increase in viscosity in the system was observed during the reaction. The polymerization reaction solution was diluted with 268 mL of DMAc, stirred for 30 minutes, and filtered using Celite as a filter aid.

42.04 g (484 mmol) of lithium bromide was added to the filtrate, and the mixture was reacted at an internal temperature of 110 ° C. for 7 hours in a nitrogen atmosphere. After the reaction, the mixture was cooled to room temperature, poured into 3.5 L of water and solidified. The coagulum was immersed in acetone, filtered and washed. The washed product was washed with stirring with 740 g of 1N sulfuric acid. After filtration, the product was washed with ion exchanged water until the pH of the washing solution became 5 or higher. As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 69,000 and Mw was 185,000. The ion exchange capacity was 2.28 meq / g. The obtained polymer was represented by the following general formula (30-9).

(Example 2)
6.10 g (15.8 mmol) of the compound represented by the general formula (30-2), 31.62 g (78.8 mmol) of the compound represented by the general formula (30-6), and the hydrophobic unit The same procedure as in Example 1 was carried out except that 12.3 g (1.5 mmol) of the formula (30-8) and 41.9 g (482.1 mmol) of lithium bromide were used.

As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 69,000 and Mw was 199,000. The ion exchange capacity was 2.24 meq / g. The obtained polymer was represented by the following general formula (30-10).

(Example 3)
2.92 g (7.86 mmol) of the compound represented by the general formula (30-3), 36.34 g (90.6 mmol) of the compound represented by the general formula (30-6), and the hydrophobic unit represented by the above formula (30-8) 12.8 g (1.56 mmol), DMAC 172 ml, lithium bromide 83.10 g (956.8 mmol) was used, and the same procedure as in Example 2 was performed.

As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 77,000 and Mw was 274,000. The ion exchange capacity was 2.45 meq / g.
Example 4
2.19 g (5.91 mmol) of the compound represented by the above general formula (30-3), 37.13 g (92.5 mmol) of the compound represented by the above general formula (30-6), 81.56 g of lithium bromide The same procedure as in Example 3 was performed except that (939.1 mmol) was used.

As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 99000 and Mw was 310,000. The ion exchange capacity was 2.45 meq / g.
(Example 5)
1.46 g (3.94 mmol) of the compound represented by the above general formula (30-3), 37.92 g (94.5 mmol) of the compound represented by the above general formula (30-6), 80.02 g of lithium bromide The same operation as in Example 3 was performed except that (921.4 mmol) was used.

As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 82,000 and Mw was 241,000. The ion exchange capacity was 2.51 meq / g.
(Example 6)
0.73 g (1.97 mmol) of the compound represented by the above general formula (30-3), 38.71 g (96.5 mmol) of the compound represented by the above general formula (30-6), 78.48 g of lithium bromide The same procedure as in Example 3 was performed except that (903.7 mmol) was used.

As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 84,000 and Mw was 229,000. The ion exchange capacity was 2.54 meq / g.
(Example 7)
37.50 g (93.45 mmol) of the compound represented by (30-13), 1.31 g (4.92 mmol) of the compound represented by (30-6), and (30-8) A polymer represented by the following formula (30-14) was obtained in the same manner as in Example 1 except that the compound was changed to 12.23 g (1.63 mmol) and lithium bromide 40.37 g (465 mmol). As a result of measuring the molecular weight of the obtained polymer by GPC, the ion exchange capacity is shown in Table 1.

(Example 8)
37.50 g (93.45 mmol) of the compound represented by (30-12), 1.31 g (4.92 mmol) of the compound represented by (30-6), and (30-8) A polymer represented by the following formula (30-15) was obtained in the same manner as in Example 1 except that the compound was changed to 12.23 g (1.63 mmol) and lithium bromide 40.37 g (465 mmol). As a result of measuring the molecular weight of the obtained polymer by GPC, the ion exchange capacity is shown in Table 1.

(Comparative Example 1)
39.57 g (98.6 mmol) of the compound represented by the above general formula (30-6), 15.68 g (1.4 mmol) of the hydrophobic unit synthesized by the above formula (30-7), bis (triphenylphosphine) Into a mixture of 2.62 g (4.0 mmol) of nickel dichloride, 10.49 g (40 mmol) of triphenylphosphine, 0.45 g (3.0 mmol) of sodium iodide, and 15.69 g (240 mmol) of zinc, 182 mL of dried DMAc was added under nitrogen. Added in.

The reaction system was heated with stirring (finally heated to 79 ° C.) and reacted for 3 hours. An increase in viscosity in the system was observed during the reaction. The polymerization reaction solution was diluted with 297 mL of DMAc, stirred for 30 minutes, and filtered using Celite as a filter aid.

25.69 g (295.8 mmol) of lithium bromide was added to the filtrate, and the mixture was reacted at an internal temperature of 110 ° C. for 7 hours in a nitrogen atmosphere. After the reaction, the mixture was cooled to room temperature, poured into 3.5 L of water and solidified. The coagulum was immersed in acetone, filtered and washed. The washed product was washed with stirring with 740 g of 1N sulfuric acid. After filtration, the product was washed with ion exchanged water until the pH of the washing solution became 5 or higher. As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 71,000 and Mw was 196,000. The ion exchange capacity was 2.26 meq / g. The obtained polymer was represented by the following general formula (40-1).

(Comparative Example 2)
39.37 g (98.1 mmol) of the compound represented by the general formula (30-6), 15.58 g (1.9 mmol) of the hydrophobic unit synthesized by the formula (30-8), bis (triphenylphosphine) Into a mixture of 2.62 g (4.0 mmol) of nickel dichloride, 10.49 g (40 mmol) of triphenylphosphine, 0.45 g (3.0 mmol) of sodium iodide and 15.69 g (240 mmol) of zinc, 181 mL of dried DMAc was added under nitrogen. Added in.

The reaction system was heated with stirring (finally heated to 79 ° C.) and reacted for 3 hours. An increase in viscosity in the system was observed during the reaction. The polymerization reaction solution was diluted with 297 mL of DMAc, stirred for 30 minutes, and filtered using Celite as a filter aid.

To the filtrate, 25.56 g (294.3 mmol) of lithium bromide was added, and the mixture was reacted at an internal temperature of 110 ° C. for 7 hours in a nitrogen atmosphere. After the reaction, the mixture was cooled to room temperature, poured into 3.5 L of water and solidified. The coagulum was immersed in acetone, filtered and washed. The washed product was washed with stirring with 740 g of 1N sulfuric acid. After filtration, the product was washed with ion exchanged water until the pH of the washing solution became 5 or higher. As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 68,000 and Mw was 175,000. The ion exchange capacity was 2.25 meq / g. The obtained polymer was represented by the following general formula (40-2).

(Comparative Example 3)
Comparative Example 2 except that 39.53 g (98.5 mmol) of the compound represented by the general formula (30-6) and 12.3 g (1.5 mmol) of the hydrophobic unit synthesized by the above formula (30-8) were used. The same was done.
As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 71,000 and Mw was 196,000. The ion exchange capacity was 2.51 meq / g.
(Comparative Example 4)
The following (40-3) was synthesized according to Japanese Patent No. 3814168.

2.36 g (5.9 mmol) of the compound represented by the general formula (40-3), 37.13 g (92.5 mmol) of the compound represented by the general formula (30-6) and the hydrophobic unit The same procedure as in Example 2 was performed except that 12.8 g (1.56 mmol) of the formula (30-8) and 27.2 g (313.0 mmol) of lithium bromide were used.

As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 73,000 and Mw was 234,000. The ion exchange capacity was 2.30 meq / g. The obtained polymer was represented by the following general formula (40-4).

Example 9
Compound (40-5) was synthesized according to the following reaction formula.

2.74 g (5.9 mmol) of the compound represented by the general formula (40-5), 37.12 g (92.5 mmol) of the compound represented by the general formula (30-6), and the hydrophobic unit represented by the above formula (30-8) The same operation as in Example 1 except that 13.1 g (1.6 mmol) and 81.5 g (938.7 mmol) of lithium bromide were used.

As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 61,000 and Mw was 178,000. The ion exchange capacity was 2.42 meq / g. The obtained polymer was represented by the following general formula (40-6).

Table 1 shows the characteristics of the sulfonated polymers obtained in Examples 1 to 9 and Comparative Examples 1 to 4, respectively.

As shown in Examples 1 to 9, compared with Comparative Examples 1 to 4, the radical resistance could be improved to the same or higher level by introducing a phosphonic acid group.

Moreover, even when the phosphonic acid group was introduced, the proton conductivity at the same level as when it was not introduced could be maintained. This is an effect of introducing a phosphonic acid group into an aromatic ring having a low electron density, as shown in Example 4 and Example 9.

In addition, as shown in Example 4 and Comparative Example 4, the phosphonic acid group is not protected, but is deprotected to maintain the proton conductivity without reducing the ion exchange capacity, and the radical Resistance could be improved.

Further, as shown in Examples 1 to 9, it can be seen that the in-plane dimensional stability factor is low and the dimensional stability during the hot water test is excellent.
(Example 10)
In place of the compound represented by the general formula (30-6), 36.54 g (98.44 mmol) of the compound represented by the general formula (30-3) and 153.9 g (1.77 mol) of lithium bromide were used. The same operation as in Example 3 was performed except that it was used.

As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 70,000 and Mw was 205,000. The ion exchange capacity was 2.35 meq / g. The obtained polymer was represented by the following general formula (30-11).

(Example 11)
Instead of the compound represented by the above general formula (30-6), 45.86 g (99 mmol) of the compound represented by the above general formula (40-5), and 8.2 g of the hydrophobic unit represented by the above formula (30-8) (1.0 mmol) and in the same manner as in Example 9 except that 154.8 g (1.78 mol) of lithium bromide was used.

As a result of measuring the molecular weight of the obtained polymer by GPC, Mn was 65,000 and Mw was 198,000. The ion exchange capacity was 2.42 meq / g. The obtained polymer was represented by the following general formula (40-7).

The properties of the sulfonated polymers obtained in Example 10 and Example 11 were evaluated in the same manner, and the results are shown in Table 2.

Example 10 and Example 11 are both examples of polymers having only phosphonic acid groups (c = 100). Each radical resistance is at the same level, but by introducing a phosphonic acid group into an aromatic ring having a low electron density as in Example 10, ie, an aromatic ring having an electron-withdrawing bond such as a ketone bond, The proton conductivity could be improved as compared with a polymer having a phosphonic acid group introduced into an aromatic ring having a high density, that is, an aromatic ring having an electron-donating bond such as an ether bond as in Example 11.

Claims (9)

A polyarylene copolymer comprising a structural unit represented by the following general formula (1):

(In the formula (1), each E independently represents a direct bond, —O—, —S—, —CO—, —SO ₂ —, —SO—, —CONH—, or —COO— group. Shows at least one selected structure,
Ar ³¹ and Ar ³³ are each independently a divalent or trivalent organic group having a benzene ring, a naphthalene ring or a nitrogen-containing heterocyclic ring, or an organic group in which part or all of the hydrogen atoms are substituted with fluorine atoms. Indicate
Ar ³² independently represents a divalent to hexavalent organic group having a benzene ring, a naphthalene ring or a nitrogen-containing heterocyclic ring, or an organic group in which part or all of the hydrogen atoms are substituted with fluorine atoms.
R ³¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, and — (CF ₂ ) _p —. (P represents an integer of 1 to 12).
e represents an integer of 0 to 10,
f represents an integer of 1 to 5,
g represents an integer of 0 to 4, and h represents an integer of 0 to 1. ) The polyarylene copolymer according to claim 1, comprising a structural unit represented by the following general formula (2).

Wherein (2) and E are each independently selected from the group consisting of a direct bond, —O—, —S—, —CO—, —SO ₂ —, —SO—, —CONH—, —COO—. Shows at least one selected structure,
R ³¹ is at least one selected from the group consisting of a direct bond, —O (CH ₂ ) _p —, —O (CF ₂ ) _p —, — (CH ₂ ) _p —, and — (CF ₂ ) _p —. (P represents an integer of 1 to 12).
e represents an integer of 0 to 10,
f represents an integer of 1 to 5,
g represents an integer of 0 to 4,
h represents an integer of 0 to 1. ) The polyarylene-based copolymer according to claim 1, further comprising a structural unit having a sulfonic acid group. The polyarylene-based copolymer according to claim 3, wherein the structural unit having a sulfonic acid group includes a structural unit having a sulfonic acid group represented by the following general formula (3-1).

[In Formula (3-1), Y is —CO—, —SO ₂ —, —SO—, a direct bond, — (CF ₂ ) _u — (u is an integer of 1 to 10), —C (CF ₃ ) represents at least one structure selected from the group consisting of ₂ —, —CONH—, —COO—, Z is a direct bond, or — (CH ₂ ) ₁ — (l is an integer of 1 to 10) ), —C (CH ₃ ) ₂ —, —O—, —S—, —CO—, —SO ₂ —, —SO—, wherein Ar represents —SO An aromatic group having a substituent represented by ₃ H or —O (CH ₂ ) _p SO ₃ H or —O (CF ₂ ) _p SO ₃ H is shown. p represents an integer of 1 to 12, m represents an integer of 0 to 3, n represents an integer of 0 to 3, and k represents an integer of 1 to 4. Among the single lines at the end of the structural unit, those not having a substituent displayed on one side mean connection with the adjacent structural unit. ] further,
The polyarylene copolymer according to any one of claims 1 to 4, comprising a structural unit having an aromatic structure represented by the following general formula (4-1).

[In Formula (4-1), A and D are independently a direct bond, or —CO—, —SO ₂ —, —SO—, — (CF ₂ ) _l — (l is an integer of 1 to 10). , — (CH ₂ ) ₁ — (l is an integer of 1 to 10), —CR ′ ₂ — (R ′ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group and a halogenated hydrocarbon group), It represents at least one structure selected from the group consisting of a cyclohexylidene group, a fluorenylidene group, —O—, and —S—, B is independently an oxygen atom or a sulfur atom, and R ¹ to R ¹⁶ are They may be the same or different and are selected from the group consisting of a hydrogen atom, a fluorine atom, a nitro group, a nitrile group, or an alkyl group, an allyl group, or an aryl group, in which some or all of the hydrogen atoms may be fluorine-substituted. And at least one atom or group. s and t represent an integer of 0 to 4, and r represents 0 or an integer of 1 or more. ] (D) / {(d) + (e)} × 100, where (d) is the number of moles of phosphonic acid groups per mole of polyarylene-based copolymer and (e) is the number of moles of sulfonic acid groups. The polyarylene copolymer according to any one of claims 1 to 5, wherein the value of is from 0.01 to 100. The polyarylene copolymer according to claim 6, wherein the value of (d) / {(d) + (e)} × 100 is 0.1 to less than 7. A polymer electrolyte comprising the copolymer according to any one of claims 1 to 7. The polymer electrolyte according to claim 7, wherein the ion exchange capacity is 0.5 to 3.5 meq / g.