JP2008247857A - Aromatic sulfonic acid ester and sulfonated polyarylene polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new aromatic sulfonic acid ester and a sulfonated polyarylene polymer, imparting high proton conductivity and enabling designing a material with suppressed swelling even under high temperature and humidified conditions. <P>SOLUTION: The new aromatic sulfonic acid ester derivative is provided, being represented by general formula (1). In general formula (1), X is an atom or a group selected from the group consisting of a halogen atom except fluorine (i.e. chlorine, bromine or iodine), -OSO<SB>2</SB>CH<SB>3</SB>and -OSO<SB>2</SB>CF<SB>3</SB>; Y is -CO- or -SO<SB>2</SB>-; Z is a direct bond, -CO-, -SO<SB>2</SB>- or -SO-; n is an integer of 2-5; and R is a 4-20C hydrocarbon group. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a novel aromatic sulfonate ester and a sulfonated polyarylene polymer.

  A polyelectrolyte is a polymer material having a protonic acid group such as a sulfonic acid group in a polymer chain, and has a property of firmly binding to a specific ion or selectively transmitting a cation or an anion. Therefore, it is formed into particles, fibers or films and used for various applications.

  For example, in a polymer electrolyte fuel cell, a pair of electrodes is provided on both sides of a proton conductive polymer electrolyte membrane (proton conductive membrane), and a fuel gas containing hydrogen such as a reformed gas is supplied to one electrode (fuel electrode). ), An oxidant gas containing oxygen such as air is supplied to the other electrode (air electrode), and chemical energy generated when the fuel is oxidized is directly taken out as electric energy.

  It is known that solid polymer fuel cells have higher power generation efficiency as the operating temperature of the cells increases. In addition, the electrode bonded to both surfaces of the proton conducting membrane contains a platinum-based electrocatalyst. However, even if a minute amount of carbon monoxide is platinum, it is poisoned and causes a decrease in the output of the fuel cell. It becomes. Moreover, it is known that the poisoning of the platinum-based electrode catalyst by carbon monoxide becomes more remarkable at lower temperatures. Therefore, in a polymer electrolyte fuel cell using methanol reformed gas containing a small amount of carbon monoxide as a fuel gas, in order to improve power generation efficiency and reduce poisoning due to carbon monoxide of the electrode catalyst, It is desirable to increase the operating temperature. In addition, in the polymer electrolyte membrane, moisture in the membrane is important in order to develop proton conduction performance at the time of power generation. For this reason, a sufficiently humidified fuel gas is generally used.

  However, when used under high-temperature humidification conditions, problems such as dimensional change of the polymer electrolyte, and perfluoro-based materials represented by Nafion (registered trademark, manufactured by DuPont), known as a polymer electrolyte having proton conductivity Since the electrolyte is non-crosslinked and has low heat resistance, there is a problem that it cannot be used at high temperatures.

On the other hand, in order to improve high-temperature durability, polymer electrolytes in which sulfonic acid groups are introduced into hydrocarbon polymers such as aromatic polyarylene ether ketones and aromatic polyarylene ether sulfones have been studied (for example, Patent Document 1, Non-Patent Documents 1 to 3).
US Pat. No. 5,403,675 Polymer Preprints, Japan, Vol.42, No.3, p.730 (1993) Polymer Preprints, Japan, Vol.42, No.7, p.2490-2492 (1993) Polymer Preprints, Japan, Vol.43, No.3, p.735-736 (1994)

  However, in general, these polymer electrolytes have a problem in that they have a large water absorption rate and swelling under high temperature humidification conditions and are not excellent in dimensional stability. Further, when the sulfonic acid concentration is lowered to suppress swelling, the proton conductivity is remarkably lowered. Furthermore, since the sulfonic acid group is eliminated or decomposed when it is continuously used under a high temperature condition, there is a problem that the durability is low.

  In addition to the above-mentioned problems, a complicated system for humidifying the fuel gas is required, so that operation at high temperature and low humidity is also required to improve the efficiency of the fuel cell system. However, the electrolyte membrane also has a problem that, in a high temperature and low humidity environment, the water retention of the membrane is lowered, and the proton conductivity is also lowered.

  That is, the object of the present invention is to increase the amount of sulfonic acid groups introduced and to impart high electrical properties, to have an excellent swelling suppression effect even under high-temperature humidification conditions, and excellent electricity under high-temperature and low-humidification conditions. It is an object of the present invention to provide a sulfonated polymer that can provide a membrane having specific properties and an aromatic sulfonate derivative that is a raw material thereof.

  The present inventors have intensively studied to solve the above problems. As a result, it has been found that the above problems can be solved by a sulfonated polyarylene having a specific structural unit, and the present invention has been completed.

Embodiments of the present invention are shown in [1] to [5] below.
[1] An aromatic sulfonic acid ester derivative represented by the following general formula (1):

[In the formula (1), X a halogen atom except fluorine (chlorine, bromine, iodine), - indicates OSO ₂ CH ₃ and atom or a group selected from the group consisting of -OSO ₂ CF _3, Y is -CO- Or -S
O ₂ − is shown. Z represents a direct bond or —CO— or —SO ₂ — or —SO—, and n represents an integer of 2 to 5. R independently represents a hydrocarbon group having 4 to 20 carbon atoms.
[2] A polyarylene polymer having a structural unit represented by the following general formula (1 ′).

[In the formula (1 ′), Y represents —CO— or —SO ₂ —. Z represents a direct bond or —CO— or —SO ₂ — or —SO—. n shows the integer of 2-5.
[3] The polyarylene copolymer of [2] further having a structural unit represented by the general formula (2).

[In the formula (2), A and D are each independently a direct bond, —O—, —S—, —CO—, —SO ₂ —.
, —SO—, —CONH—, —COO—, — (CF ₂ ) _i — (i is an integer of 1 to 10), — (CH ₂ ) _j — (j is an integer of 1 to 10) , —CR ″ ₂ — (R ″ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group), a cyclohexylidene group, or a fluorenylidene group. Wherein B independently represents an oxygen atom or a sulfur atom, R ^{1 to} R ¹⁶ may be the same or different from each other, and a hydrogen atom, a fluorine atom, an alkyl group, or a part or all of them are halogenated. And at least one atom or group selected from the group consisting of a halogenated alkyl group, an allyl group, an aryl group, a nitro group and a nitrile group, s and t each independently represent an integer of 0 to 4, and r is 0 or an integer of 1 or more is shown. ]
[4] The polyarylene copolymer of [2] or [3], wherein the general formula (1 ′) is a structural unit represented by the following general formula (1′a).

[In the formula (1′a), Z represents a direct bond, —CO—, —SO ₂ — or —SO—. n
Represents an integer of 2 to 5. ]
[5] A solid polymer electrolyte membrane comprising the polyarylene copolymer of [3] and [4].

  According to the present invention, an aromatic compound in which a plurality of sulfonic acid ester groups are regioselectively introduced into a specific aromatic ring, and an aromatic compound having a plurality of sulfonic acid groups derived from the compound only at the terminal portion of the side chain. A copolymer having a group unit and a unit having no sulfonic acid group can be provided. Due to the effect of the aromatic unit having a plurality of sulfonic acid groups only at the end portion of the side chain of the present invention, the side with the plurality of sulfonic acid groups is also present in the copolymer with the aromatic unit having no sulfonic acid group. The hydrophobicity of the main chain portion of the aromatic unit possessed only at the end of the chain is sufficiently exhibited. For this reason, it becomes possible to provide a high proton conductivity due to the ability to synthesize a copolymer having a high sulfonic acid concentration, and to design a material in which swelling is suppressed even under high-temperature humidification conditions. Furthermore, by combining multiple sulfonic acids with the same aromatic ring, the acidity of the sulfonic acid is improved and the sulfonic acid density in the hydrophilic part is high, so excellent proton conductivity is maintained even in high-temperature and low-humidity environments. It becomes possible to do.

Hereinafter, the aromatic sulfonic acid ester derivative of the present invention will be described in detail.
<Aromatic sulfonic acid ester derivative>
The aromatic sulfonic acid ester derivative of the present invention is represented by the following general formula (1).

[In the formula (1), X is a halogen atom other than fluorine (chlorine, bromine, iodine), - indicates OSO ₂ CH ₃ and atom or a group selected from the group consisting of -OSO ₂ CF _3, halogen atoms are preferred. Y represents —CO— or —SO ₂ —, preferably —CO—. Z represents a direct bond or —CO— or —SO ₂ — or —SO—, and is preferably a direct bond. n shows the integer of 2-5, Preferably it is 2-3.

  R independently represents a hydrocarbon group having 4 to 20 carbon atoms. Specifically, t-butyl group, sec-butyl group, isobutyl group, n-butyl group, n-pentyl group, neopentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, heptyl group, octyl group, 2- Ethylhexyl group, cyclopentylmethyl group, adamantyl group, cyclohexylmethyl group, adamantylmethyl group, tetrahydrofurfuryl group, 2-methylbutyl group, 3,3-dimethyl-2,4-dioxolanemethyl group, bicyclo [2.2.1] Examples thereof include straight chain hydrocarbon groups such as heptyl group and bicyclo [2.2.1] heptylmethyl group, branched hydrocarbon groups, and alicyclic hydrocarbon groups.

  In the case of a copolymer described later, among these, a neopentyl group, a tetrahydrofurfuryl group, a cyclopentylmethyl group, a cyclohexylmethyl group, an adamantylmethyl group, a bicyclo [2.2.1] heptylmethyl group are preferable, and a neopentyl group Is more preferable.

  Examples of such aromatic sulfonic acid esters include the following.

In addition, examples of the aromatic sulfonic acid ester represented by the general formula (1) of the present invention include compounds in which the chlorine atom is replaced with a bromine atom or an iodine atom in the exemplified compounds. Further, compounds in which the chlorine atom is replaced with —OSO ₂ CH ₃ and —OSO ₂ CF ₃ are also included.

  The method for synthesizing such an aromatic sulfonic acid ester derivative is not particularly limited as long as the compound represented by the formula (1) can be synthesized. However, when a plurality of sulfonate groups are introduced using a method using a sulfonating agent after the main skeleton is synthesized, it is often difficult to limit the introduction position. In order to synthesize the sulfonic acid ester derivative as in the present invention, a method in which an aromatic ring portion having a plurality of sulfonic acid ester groups is first synthesized, followed by a coupling reaction with a structure constituting a specific main chain portion, etc. There is. Specifically, there are the following methods.

  Synthesis of an aromatic ring moiety having a plurality of sulfonic acid ester groups is accomplished by sulfonating a halogenated benzene by a generally known method, and protecting the resulting sulfonated benzene with a protecting group. Esters are obtained. At this time, a skeleton into which a plurality of sulfonic acids are introduced can be synthesized by adjusting conditions such as the type and temperature of the sulfonating agent.

  A benzene ring is preferably used for the aromatic ring moiety having a plurality of sulfonate groups of the present invention. By introducing a plurality of sulfonyl groups into one ring, the electron density of the ring is lowered, so that an effect of suppressing the elimination of sulfonic acid can be expected. Synthesis is possible in the same way using various polycyclic aromatic compounds such as naphthalene and anthracene, but the difficulty in controlling the introduction position of the sulfonate group in the molecule increases, resulting in a decrease in yield during synthesis, etc. And the problem that the effect of increasing the density of the sulfonic acid is diminished due to the ring structure and the molecule itself becoming too large.

The skeleton constituting the main chain portion is a main skeleton such as benzophenone, diphenyl sulfoxide, diphenyl sulfone, and one phenyl group has two halogen groups other than fluorine necessary for polymerization, and the other skeleton. As the phenyl group, one having a functional group for coupling with the skeleton into which the plurality of sulfonic acids are introduced may be used. As the functional group used for coupling, halogen, mercapto group, boronic acid or the like can be used. However, using a functional group different from the halogen group of the main chain used for polymerization can improve the yield of the target product. Is preferable. Specifically, bromine, iodine, boronic acid, or the like can be used when the functional group substituted with the aromatic ring that forms the main chain upon polymerization is chlorine.

  For the synthesis of this skeleton, a generally known synthesis method can be used. Specifically, a method using the Friedel-Crafts reaction via benzoyl chloride, oxidation to sulfinyl group or sulfonyl group by peroxide via thioetherification by nucleophilic substitution reaction of phenylthiol and phenyl fluoride Examples include a method using a reaction.

  A generally known method can be used for coupling the aromatic ring part having a plurality of sulfonate groups obtained as described above and the part constituting the main chain part. For example, a halogenated benzene having a sulfonate group is treated with a metal such as zinc to convert it to an organometallic compound. At this time, a highly active metal such as magnesium or lithium reacts with the protected sulfonic acid ester, and therefore a metal having moderate activity such as zinc or indium is preferable. Next, a target aromatic sulfonic acid ester derivative can be obtained by performing a cross-coupling reaction with a portion constituting the main chain portion using a palladium catalyst or a nickel catalyst.

The obtained aromatic sulfonic acid ester derivative is purified as necessary.
The identification method of the aromatic sulfonic acid ester derivative is not particularly limited, and a known method such as NMR is employed.

<Sulfonated polyarylene polymer>
The polyarylene polymer according to the present invention has a structural unit represented by the following general formula (1 ′).

[In the formula (1 ′), Y represents —CO— or —SO ₂ —, preferably —CO—.
Z represents a direct bond or —CO— or —SO ₂ — or —SO—, and is preferably a direct bond. n shows the integer of 2-5, Preferably it is 2-3.

<Sulfonated polyarylene copolymer>
The polyarylene polymer according to the present invention may be a homopolymer of a structural unit represented by the above formula (1 ′), and usually contains a structural unit represented by the general formula (4). desirable. When such a structural unit is contained, the strength and water resistance of the polymer can be improved.

In formula (4), A and D are each independently a direct bond, —O—, —S—, —CO—, —S.
O ₂ —, —SO—, —CONH—, —COO—, — (CF ₂ ) _i — (i is an integer of 1 to 10), — (CH ₂ ) _j — (j is an integer of 1 to 10) -CR ' _2- (R' represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group), at least one selected from the group consisting of a cyclohexylidene group and a fluorenylidene group The structure of the species is shown. Among these, a direct bond, —O—, —CO—, —SO ₂ —, —CR ′ ₂ —, a cyclohexylidene group and a fluorenylidene group are preferable. Examples of R ′ include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, hexyl group, octyl group, decyl group, octadecyl group, ethylhexyl group, phenyl group, trifluoro group. Examples thereof include a methyl group and a substituent in which some or all of hydrogen atoms in these substituents are halogenated.

B independently represents an oxygen atom or a sulfur atom, preferably an oxygen atom.
R ^{1 to} R ¹⁶ may be the same as or different from each other, and are a hydrogen atom, a fluorine atom, an alkyl group, a halogenated alkyl group, an allyl group, an aryl group, a nitro group, and a nitrile group, which are partially or completely halogenated. At least one atom or group selected from the group consisting of

Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, an amyl group, a hexyl group, a cyclohexyl group, and an octyl group.
Examples of the halogenated alkyl group include a trifluoromethyl group, a pentafluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group.

As said allyl group, a propenyl group etc. are mentioned, for example. Examples of the aryl group include a phenyl group and a pentafluorophenyl group.
s and t show the integer of 0-4. r shows 0 or an integer greater than or equal to 1, and an upper limit is 100 normally, Preferably it is 1-80.

As a preferable structure of the structural unit (4), in the above formula (4),
(1) s = 1 and t = 1, A is —CR ′ ₂ —, a cyclohexylidene group or a fluorenylidene group, B is an oxygen atom, and D is —CO— or —SO ₂ —. , R ^{1 to} R ¹⁶ are hydrogen atoms or fluorine atoms,
(2) a structure in which s = 1 and t = 0, B is an oxygen atom, D is —CO— or —SO ₂ —, and R ^{1 to} R ¹⁶ are a hydrogen atom or a fluorine atom,
(3) s = 0 and t = 1, A is —CR ′ ₂ —, a cyclohexylidene group or a fluorenylidene group, B is an oxygen atom, and R ^{1 to} R ¹⁶ are a hydrogen atom, a fluorine atom or a nitrile group The structure which is is mentioned.

The monomer or oligomer (hereinafter also referred to as “compound (4 ′)”) that can be the structural unit (4) can be synthesized, for example, by referring to the method described in JP-A No. 2004-137444.

<Method for producing sulfonated polyarylene polymer>
The sulfonated polyarylene polymer of the present invention can be synthesized, for example, by the method described in JP-A No. 2004-137444.

Specifically, first, an aromatic sulfonic acid ester derivative represented by the above formula (1) and a compound represented by the following general formula (4 ′) which is a precursor of the above compound (4) are present in the presence of a catalyst. It can be synthesized by copolymerizing under the above to produce a polyarylene having a sulfonate group, deesterifying the sulfonate group, and converting the sulfonate group to a sulfonate group.

In the formula (4 ′), X represents a halogen atom other than fluorine (chlorine, bromine, iodine), —OSO ₂ CH ₃
And an atom or group selected from the group consisting of —OSO ₂ CF _3, preferably chlorine or bromine. ^{A, B, D, R 1} ~R 16, s, t, r is, A, in the formula (4) B, which is ^{D, R 1 ~R 16, s} , t, synonymous with r.

  The catalyst used in the above polymerization is a catalyst system containing a transition metal compound, and such a catalyst system includes (i) a compound that becomes a transition metal salt and a ligand (hereinafter referred to as `` ligand component ''). Or a transition metal complex coordinated with a ligand (including a copper salt) and (ii) a reducing agent as essential components, and a salt is added to increase the polymerization rate. May be.

  Specific examples of these catalyst components, use ratio of each component, polymerization conditions such as reaction solvent, concentration, temperature, time, etc. are used with reference to the compounds and conditions described in JP-A No. 2001-342241. Or can be set.

  The ion exchange capacity of the sulfonated polyarylene produced by the above method is usually 0.3 to 5 meq / g, preferably 0.5 to 4 meq / g, more preferably 0.8 to 3.5 meq / g. It is. If the ion exchange capacity is lower than the above range, proton conductivity tends to be low and power generation performance tends to be low, and if it exceeds the above range, water resistance tends to be greatly reduced.

  However, the amount of ion exchange could be significantly increased by using the newly sulfonated monomer compared to the case of using a conventional monosulfonated monomer. For this reason, the polymer synthesized this time tends to have a higher proton conductivity than the conventional polymer.

  The ion exchange capacity can be adjusted, for example, by changing the types, use ratios, combinations, and the like of the compound (1 ′) and the compound (4 ′). In the sulfonated polyarylene of the present invention, the structural unit (1) is 0.5 to 100 mol%, preferably 10 to 99.999 mol%, and the structural unit (4) is 99.5 to 0 mol. %, Preferably 90 to 0.001 mol%.

  The weight average molecular weight of the sulfonated polyarylene thus obtained is 10,000 to 1,000,000, preferably 20,000 to 500,000, more preferably 100,000 to 40 in terms of polystyrene by gel permeation chromatography (GPC). Ten thousand.

  Such a polyarylene polymer has high proton conductivity, and can be suitably used as a proton conductive membrane, an electrode electrolyte, and a binder for a fuel cell. An electrode electrolyte containing such a polyarylene polymer is also suitable as a membrane electrode assembly.

[Example]
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples. The various measurement items in the examples were determined as follows.

(Molecular weight)
As for the molecular weight of the polymer, the weight average molecular weight in terms of polystyrene was determined by GPC. N-methyl-2-pyrrolidone to which lithium bromide was added was used as a solvent.

(Ion exchange capacity)
The resulting sulfonated polymer is washed with water until the pH becomes 4 to 6, the free remaining acid is removed and washed thoroughly, and after drying, a predetermined amount is weighed, and THF / water It was dissolved in a mixed solvent, phenolphthalein was used as an indicator, titrated with a standard solution of NaOH, and the ion exchange capacity was determined from the neutralization point.

(Proton conductivity)
First, five platinum wires (φ = 0.5 mm) were pressed at 5 mm intervals on the surface of a strip-shaped sample film (40 mm × 5 mm), and in a constant temperature and humidity apparatus (“JW241” manufactured by Yamato Scientific Co., Ltd.) A sample was held on the substrate, and AC resistance was obtained by measuring AC impedance between platinum wires. The measurement is performed using a chemical impedance measurement system manufactured by NF Circuit Design Block Co., Ltd. as a resistance measuring device, and the distance between the lines is set to 5 to 20 mm under the conditions of AC 10 kHz under an environment where the relative humidity is changed at 85 ° C. Changed and went. Subsequently, the specific resistance R of the membrane was calculated from the distance between the lines and the resistance gradient according to the following formula, and the proton conductivity was calculated from the reciprocal of the specific resistance R.
Specific resistance R (Ω · cm) = 0.5 (cm) × film thickness (cm) × resistance-to-resistance gradient (Ω / cm)
(Water resistance test)
First, the length of the long side and the short side of the sample film cut to 2 × 3 cm was measured accurately. The sample film was placed in a heat resistant resin container, a sufficient amount of water was added and sealed, and then heat-treated at 95 ° C. and 120 ° C. for 24 hours using an oven or a pressure cooker tester, respectively. After completion of heating, the sample was allowed to cool to room temperature, the sample film was taken out, and water droplets on the surface were lightly wiped, and then the length, film thickness, and weight of each side were measured. Using the obtained numerical values, the water resistance of the sample was calculated as follows. Dimensional change rate (%) = (long side after test (cm) / long side before test (cm)) + (short side after test (cm) / short side before test (cm)) / 2 × 100
<Example 1>
(1) Synthesis of neopentyl bromobenzene-2,4-disulfonate In a four-necked flask equipped with a dropping funnel, thermometer and Dimroth, 186 g (1.2 mol) of chlorosulfonic acid was taken under a nitrogen atmosphere, and bromo was stirred. 31.4 g (0.2 mol) of benzene was added dropwise from the dropping funnel over about 30 minutes. After reacting at 120 ° C. for 6 hours, the reaction solution was poured into ice water, and the organic matter was extracted with ethyl acetate. The organic layer was dried using magnesium sulfate, and then the solvent was distilled off using an evaporator to obtain 70 g of a crude product of bromobenzene-2,4-disulfonyl chloride.

To a three-necked flask, 118.9 g (1.5 mol) of pyridine and 17.4 g (0.198 mol) of 2,2-dimethyl-1-propanol were added and cooled to 0 ° C. The crude sulfonyl chloride product obtained above was added slowly to this solution.
After reacting for 4 hours while keeping the temperature at 5 ° C. or lower in an ice bath, the ice bath was removed and the temperature was slowly raised to room temperature. The reaction solution was poured into 500 ml of an aqueous hydrochloric acid solution, and the organic matter was extracted with ethyl acetate. The organic layer was washed with an aqueous hydrochloric acid solution, a 5% sodium hydrogen carbonate solution and then with a saturated saline solution, and then the organic layer was dried over magnesium sulfate. The solvent was distilled off using an evaporator, and the resulting crude product was recrystallized from an ethyl acetate / hexane solution to obtain 72 g of a target crude crystal.
(2) Synthesis of 4- (2,5-dichlorobenzoyl) -benzeneboronic acid-2,2-dimethyl-1,3-propanediol ester Into a three-necked flask equipped with a Dean-Stark tube and thermometer, 300 ml of toluene was placed. 2,5-dichloro-4′-bromobenzophenone 115.5 g (0.35 mol), 2,2-dimethyl-1,3-propanediol 60.5 g (0.58 mol), p-toluenesulfonic acid monohydrate 6.66 g (0.04 mol) of the product was added, and the reaction was carried out while removing the water produced by heating to reflux at 130 ° C. After about 20 hours, it was confirmed that a theoretical amount (about 6.3 g) of water was recovered, and the reaction solution was transferred to a 1 L beaker. The reaction solution was cooled in a salt ice bath, and the precipitated crystals were collected by filtration and rinsed with ethanol to obtain 120 g of white crystals.

In a three-necked flask, 500 ml of dehydrated tetrahydrofuran was taken under a nitrogen atmosphere, 41.2 g (0.1 mol) of the above white crystals were added and dissolved, and then −7 in a dry ice / acetone bath.
Cooled to 5 ° C. A 10M hexane solution of n-butyllithium was slowly added dropwise using a 10.5 ml (0.105 mol) syringe and reacted at -65 ° C for 1 hour. Then, 15.5 g (0.15 mol) of trimethyl borate was added dropwise and reacted at −60 ° C. for 1 hour. Thereafter, the cooling bath was removed, and the temperature was slowly raised to room temperature. Next, a hydrochloric acid solution was added to the reaction solution and heated to 70 ° C. for reaction. After cooling, acetone was added and stirred, the solvent was removed by an evaporator, and the precipitated crude crystals were collected by filtration. Recrystallization from an ethyl acetate / hexane solution gave 23 g of the objective white crystal.
(3) Synthesis of 4 ′-(2,5-dichlorobenzoyl) biphenyl-2,4-disulfonate neopentyl 77 ml of toluene was placed in a three-necked flask equipped with a Dimroth and thermometer, and neopentyl bromobenzene-2,4-disulfonate. 14.0 g (0.03 mol) and 1.06 g (0.9 mmol) of tetrakistriphenylphosphine palladium were added and stirred. Further, 32 g of 2 mol / l potassium carbonate aqueous solution was added, and then 4- (2,5-dichlorobenzoyl) -benzeneboronic acid-2,2-dimethyl-1,3-propanediol ester was dispersed in 16 ml of ethanol. In addition, the mixture was heated to reflux for 6 hours. To the reaction solution, 1.8 g of 30% aqueous hydrogen peroxide was added and stirred for 1 hour, and then extracted with ethyl acetate added to the reaction solution. The organic layer was washed with water and then with saturated brine, and then dried over magnesium sulfate. The solvent was distilled off with an evaporator, and the resulting crude crystals were recrystallized from an acetone / hexane solution to obtain 12 g of a target product having a structure represented by the following formula (I). An NMR chart of the obtained compound is shown in FIG.

<Example 2>
In a 1 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube, 54.5 g (86.8 mmol) of neopentyl sulfonate obtained in Example 1 and hydrophobicity of Mn11,200 represented by the following structural formula (II) Unit 34.3 g (3.2 mmol), bis (triphenylphosphine) nickel dichloride 1.77 g (3.0 mmol), sodium iodide 0.41 g (2.7 mmol), triphenylphosphine 9.44 g (36.0 mmol) Then, 14.1 g (216 mmol) of zinc was weighed and replaced with dry nitrogen.

  270 mL of N, N-dimethylacetamide (DMAc) was added thereto, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 480 mL of DMAc was added for dilution, and insoluble matters were filtered off.

  The obtained solution was put into a 2 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. The mixture was heated and stirred at 115 ° C., and 23 g (260 mmol) of lithium bromide was added. After stirring for 7 hours, the product was precipitated by pouring into 7 L of ion-exchanged water. Subsequently, acetone, 1N hydrochloric acid, and pure water were washed in this order and dried to obtain 70 g of the desired polymer. The weight average molecular weight (Mw) of the obtained polymer was 235,000. The obtained polymer is presumed to be a sulfonated polymer represented by the formula (III). The ion exchange capacity of this polymer was 2.3 meq / g.

<Example 3>
In a 1 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube, 54.4 g (86.8 mmol) of neopentyl sulfonate obtained in Example 1 and hydrophobicity of Mn8,200 represented by the following structural formula (IV) Unit 34.3 g (4.2 mmol), bis (triphenylphosphine) nickel dichloride 2.38 g (3.6 mmol), sodium iodide 0.41 g (2.7 mmol), triphenylphosphine 9.55 g (36.4 mmol) Then, 14.3 g (218 mmol) of zinc was weighed and replaced with dry nitrogen.

  270 mL of N, N-dimethylacetamide (DMAc) was added thereto, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 480 mL of DMAc was added for dilution, and insoluble matters were filtered off.

  The obtained solution was put into a 2 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. The mixture was heated and stirred at 115 ° C., and 23 g (260 mmol) of lithium bromide was added. After stirring for 7 hours, the product was precipitated by pouring into 7 L of ion-exchanged water. Subsequently, acetone, 1N hydrochloric acid, and pure water were washed in this order and dried to obtain 70 g of the desired polymer. The weight average molecular weight (Mw) of the obtained polymer was 235,000. The obtained polymer is presumed to be a sulfonated polymer represented by the formula (III). The ion exchange capacity of this polymer was 2.3 meq / g.

<Example 4>
In a 1 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube, 54.0 g (86.0 mmol) of neopentyl sulfonate obtained in Example 1 and hydrophobicity of Mn 9,000 represented by the following structural formula (VI) Unit 35.6 g (4.0 mmol), bis (triphenylphosphine) nickel dichloride 2.36 g (3.6 mmol), sodium iodide 0.40 g (2.7 mmol), triphenylphosphine 9.44 g (36.0 mmol) Then, 14.1 g (216 mmol) of zinc was weighed and replaced with dry nitrogen.

  290 mL of N, N-dimethylacetamide (DMAc) was added thereto, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 500 mL of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 2 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. The mixture was heated and stirred at 115 ° C., and 22.4 g (258 mmol) of lithium bromide was added. After stirring for 7 hours, the product was precipitated by pouring into 7 L of ion-exchanged water. Subsequently, acetone, 1N hydrochloric acid, and pure water were washed in this order and dried to obtain 68 g of the desired polymer. The weight average molecular weight (Mw) of the obtained polymer was 250,000. The obtained polymer is presumed to be a sulfonated polymer represented by the formula (VII). The ion exchange capacity of this polymer was 2.3 meq / g.

<Example 5>
In a 1 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introducing tube, 53.3 g (85.0 mmol) of neopentyl sulfonate obtained in Example 1 and hydrophobicity of Mn7,000 represented by the following structural formula (VIII) Unit 35.6 g (5.0 mmol), bis (triphenylphosphine) nickel dichloride 2.36 g (3.6 mmol), sodium iodide 0.40 g (2.7 mmol), triphenylphosphine 9.44 g (36.0 mmol) Then, 14.1 g (216 mmol) of zinc was weighed and replaced with dry nitrogen.

  290 mL of N, N-dimethylacetamide (DMAc) was added thereto, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 500 mL of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 2 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. The mixture was heated and stirred at 115 ° C., and 22.1 g (255 mmol) of lithium bromide was added. After stirring for 7 hours, the product was precipitated by pouring into 7 L of ion-exchanged water. Subsequently, acetone, 1N hydrochloric acid, and pure water were washed in this order and dried to obtain 68 g of the desired polymer. The weight average molecular weight (Mw) of the obtained polymer was 250,000. The obtained polymer is presumed to be a sulfonated polymer represented by the formula (IX). The ion exchange capacity of this polymer was 2.3 meq / g.

<Example 6>
In a 1 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube, 53.3 g (85.0 mmol) of neopentyl sulfonate obtained in Example 1, Mn7 represented by the following structural formula (X),
000 hydrophobic units 35.6 g (5.0 mmol), bis (triphenylphosphine) nickel dichloride 2.36 g (3.6 mmol), sodium iodide 0.40 g (2.7 mmol), triphenylphosphine 9.44 g ( 36.0 mmol) and 14.1 g (216 mmol) of zinc were weighed and replaced with dry nitrogen.

  290 mL of N, N-dimethylacetamide (DMAc) was added thereto, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 500 mL of DMAc was added for dilution, and insoluble matter was filtered off.

  The obtained solution was put into a 2 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. The mixture was heated and stirred at 115 ° C., and 22.1 g (255 mmol) of lithium bromide was added. After stirring for 7 hours, the product was precipitated by pouring into 7 L of ion-exchanged water. Subsequently, acetone, 1N hydrochloric acid, and pure water were washed in this order and dried to obtain 68 g of the desired polymer. The weight average molecular weight (Mw) of the obtained polymer was 250,000. The obtained polymer is presumed to be a sulfonated polymer represented by the formula (XI). The ion exchange capacity of this polymer was 2.3 meq / g.

<Comparative Example 1>
In a 1L three-necked flask equipped with a stirrer, thermometer, and nitrogen inlet tube, the following structural formula (XII)
68.8 g (144 mmol) of neopentyl 4 ′-(2,5-dichlorobenzoyl) -biphenyl-4-sulfonate shown in the above, 11.0 g (1 .1 of hydrophobic unit of Mn 11,200 shown in the above structural formula (II). 0 mmol), bis (triphenylphosphine) nickel dichloride 3.79 g (5.8 mmol), sodium iodide 0.65 g (4.4 mmol), triphenylphosphine 15.2 g (58.0 mmol), zinc 22.75 g (348 mmol) ) And weighed with dry nitrogen.

  N, N-dimethylacetamide (DMAc) 255 mL was added thereto, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, DMAc 480 mL was added for dilution, and insoluble matters were filtered.

  The obtained solution was put into a 2 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. The mixture was heated and stirred at 115 ° C., and 37.5 g (432 mmol) of lithium bromide was added. After stirring for 7 hours, the product was precipitated by pouring into 7 L of ion-exchanged water. Subsequently, acetone, 1N hydrochloric acid, and pure water were washed in this order and dried to obtain 70 g of the desired polymer. The weight average molecular weight (Mw) of the obtained polymer was 335,000. The obtained polymer is presumed to be a sulfonated polymer represented by the formula (XIII). The ion exchange capacity of this polymer was 2.3 meq / g.

<Comparative example 2>
In a 1 L three-necked flask equipped with a stirrer, thermometer and nitrogen inlet tube, the following structural formula (XIV)
4 '-(2,5-dichlorobenzoyl) -biphenyl-2', 4-disulfonic acid neopentyl 54.5 g (86.8 mmol), Mn11,200 hydrophobic unit 34 represented by the above structural formula (II) .3 g (3.2 mmol), bis (triphenylphosphine) nickel dichloride 1.77 g (3.0 mmol), sodium iodide 0.41 g (2.7 mmol), triphenylphosphine 9.44 g (36.0 mmol), zinc 14.1 g (216 mmol) was weighed and replaced with dry nitrogen.

  270 mL of N, N-dimethylacetamide (DMAc) was added thereto, and stirring was continued for 3 hours while maintaining the reaction temperature at 80 ° C. Then, 480 mL of DMAc was added for dilution, and insoluble matters were filtered off.

The obtained solution was put into a 2 L three-necked flask equipped with a stirrer, a thermometer, and a nitrogen introduction tube. The mixture was heated and stirred at 115 ° C., and 23 g (260 mmol) of lithium bromide was added. After stirring for 7 hours, the product was precipitated by pouring into 7 L of ion-exchanged water. Subsequently, after washing in order of acetone, 1N hydrochloric acid and pure water, it was dried to obtain 70 g of the intended polymer. The weight average molecular weight (Mw) of the obtained polymer was 240,000. The obtained polymer is presumed to be a sulfonated polymer represented by the formula (XV). The ion exchange capacity of this polymer was 2.3 meq / g.

(Production of evaluation film)
The polymers obtained in Examples 1 to 6 and Comparative Examples 1 and 2 were each dissolved in N-methyl-2-pyrrolidone at a concentration of 14 to 16%, cast on a glass plate, and then dried to a film thickness of 40 μm. A film was obtained.
(Evaluation)
Using the obtained film, a water resistance test and measurement of proton conductivity were performed. The results are shown in Table 1.

  As shown in Table 1, the membrane composed of the sulfonated polymer (Examples 2 to 6) synthesized using the aromatic sulfonate ester derivative (Example 1) of the present invention has dimensional stability in a high-temperature humidified environment. It is excellent, and the decrease in proton conductivity under high temperature and low humidity environment is kept low, and it exhibits excellent electrical characteristics.

FIG. 1 shows an NMR chart of the compound obtained in Example 1.

Claims (5)

An aromatic sulfonic acid ester derivative represented by the following general formula (1):

[In the formula (1), X a halogen atom except fluorine (chlorine, bromine, iodine), - indicates OSO ₂ CH ₃ and atom or a group selected from the group consisting of -OSO ₂ CF _3, Y is -CO- Or -S
O ₂ − is shown. Z represents a direct bond or —CO— or —SO ₂ — or —SO—, and n represents an integer of 2 to 5. R independently represents a hydrocarbon group having 4 to 20 carbon atoms. ] A polyarylene polymer having a structural unit represented by the following general formula (1 ′).

[In the formula (1 ′), Y represents —CO— or —SO ₂ —. Z represents a direct bond or —CO— or —SO ₂ — or —SO—. n shows the integer of 2-5. ] Furthermore, it has a structural unit represented by General formula (2), The polyarylene-type copolymer of Claim 2 characterized by the above-mentioned.

[In the formula (2), A and D are each independently a direct bond, —O—, —S—, —CO—, —SO ₂ —.
, —SO—, —CONH—, —COO—, — (CF ₂ ) _i — (i is an integer of 1 to 10), — (CH ₂ ) _j — (j is an integer of 1 to 10) , —CR ″ ₂ — (R ″ represents an aliphatic hydrocarbon group, an aromatic hydrocarbon group or a halogenated hydrocarbon group), a cyclohexylidene group, or a fluorenylidene group. Wherein B independently represents an oxygen atom or a sulfur atom, R ^{1 to} R ¹⁶ may be the same or different from each other, and a hydrogen atom, a fluorine atom, an alkyl group, or a part or all of them are halogenated. And at least one atom or group selected from the group consisting of a halogenated alkyl group, an allyl group, an aryl group, a nitro group and a nitrile group, s and t each independently represent an integer of 0 to 4, and r is 0 or an integer of 1 or more is shown. ] The polyarylene copolymer according to claim 2 or 3, wherein the general formula (1 ') is a structural unit represented by the following general formula (1'a).

[In the formula (1′a), Z represents a direct bond, —CO—, —SO ₂ — or —SO—. n
Represents an integer of 2 to 5. ] A solid polymer electrolyte membrane comprising the polyarylene copolymer according to claim 3.

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