JP2007031398A - Method for producing sulfonic acid group-containing aromatic dihalide - Google Patents

Abstract

【Task】
The present invention is intended to provide a method for producing a sulfonic acid group-containing aromatic dihalide that is environmentally friendly because there are few by-products such as waste sulfuric acid and can be mass-produced and reduced in production costs. Furthermore, when a polymer electrolyte fuel cell is used, a sulfonic acid group as a monomer of an aromatic polyether polymer useful as a polymer electrolyte material that can achieve high output, high energy density, and high durability. It is intended to provide a method for producing a contained aromatic dihalide.
[Solution]
The method for producing a sulfonic acid group-containing aromatic dihalide according to the present invention is a method for producing a sulfonic acid group-containing aromatic dihalide according to the present invention, wherein the sulfonation reaction is carried out by bringing the aromatic dihalide into contact with liquid sulfuric anhydride. It is a feature.
[Selection figure] None

Description

  The present invention relates to a method for producing a sulfonic acid group-containing aromatic dihalide, and further to a method for producing a sulfonic acid group-containing aromatic dihalide as a monomer of an aromatic polyether polymer useful as a polymer electrolyte material.

  A fuel cell is a power generation device with low emissions, high energy efficiency, and low environmental burden. For this reason, it is in the spotlight again in recent years to the protection of the global environment. Compared to conventional large-scale power generation facilities, this is a power generation device expected in the future as a relatively small-scale distributed power generation facility, and as a power generation device for mobile objects such as automobiles and ships. It is also attracting attention as a power source for small mobile devices and portable devices, and is expected to be installed in mobile phones and personal computers in place of secondary batteries such as nickel metal hydride batteries and lithium ion batteries.

  So far, for example, Nafion (registered trademark), which is a perfluorosulfonic acid polymer, has been used in an electrolyte membrane of a polymer electrolyte fuel cell. However, Nafion (registered trademark) is a perfluoro polymer produced through multi-step synthesis, so it is very expensive, and methanol has a high affinity with water to form a cluster structure. However, there is a problem that the fuel easily permeates the electrolyte membrane, that is, the fuel crossover is large. In addition, since the hot water resistance and methanol resistance are insufficient, there is a problem that the mechanical strength of the film is reduced due to swelling, and further there are problems of disposal treatment after use and difficulty in recycling materials.

  In order to overcome such drawbacks, some efforts have already been made on polymer electrolyte materials based on non-perfluoro hydrocarbon polymers. As the polymer skeleton, aromatic polyether ketone and aromatic polyether sulfone have been particularly actively studied from the viewpoint of heat resistance and chemical stability. For example, a sulfonated product (for example, refer to Non-Patent Document 1) of a poorly soluble aromatic polyetheretherketone (including Victrex (registered trademark) PEEK (registered trademark) (manufactured by Victrex)), and aromatic. Polysulfone which is polyethersulfone (hereinafter sometimes abbreviated as PSF) (including UDEL P-1700 (manufactured by Amoco)) and polyethersulfone (hereinafter sometimes abbreviated as PES) ( Sulfonated products (for example, Non-Patent Document 2), etc.) have been reported, such as Sumika Excel PES (manufactured by Sumitomo Chemical Co., Ltd.). This tendency was remarkable in the fuel aqueous solution and in the composition having a high sulfonic acid group density. In addition, the method of introducing sulfonic acid groups onto the aromatic ring by sulfonation reaction (polymer reaction) of these polymers has a problem that the amount and position of the sulfonic acid groups introduced into the polymer cannot be precisely controlled. It was.

  As a method for improving this, a sulfonated aromatic polyether having a controlled amount of sulfonic acid group obtained by polymerization using a monomer having a sulfonic acid group introduced therein has been reported (for example, Patent Document 1, Non-Patent Document). Reference 3). However, since a large excess of fuming sulfuric acid is used as a sulfonating agent when producing a sulfonic acid group aromatic dihalide used as a monomer here, a large amount of waste sulfuric acid and / or neutralized inorganic salt is present. And thus difficult to separate from the sulfonic acid group-containing aromatic dihalide. In addition, in such a production method in which a large amount of by-products are generated, not only the yield is lowered when producing on an industrial scale, but also purification steps are increased, or by-products, waste water, waste solvents There is a problem that the disposal cost of the sulfonic acid group aromatic dihalide is high and the resulting sulfonic acid group aromatic dihalide is expensive. Further, the high environmental load due to such a large amount of waste is not sufficient as a method for producing a monomer for use in a fuel cell characterized by a low environmental burden.

  Further, as a known sulfonation technique using sulfuric anhydride, there is a method using gaseous sulfuric anhydride (see, for example, Patent Document 2). In this method, a sulfonated organic compound is charged into a reaction vessel, and a sulfuric acid-containing gas is blown into the reaction vessel with stirring to obtain a sulfonated product. However, in order to produce a sulfonated product in large quantities, a huge reaction apparatus is required, which is not suitable for mass production and reduction of production costs. Further, even if the liquid compound can be reacted by blowing an anhydrous sulfuric acid-containing gas, it is difficult to react the solid compound uniformly. Furthermore, in order to uniformly react the solid compound, a method of using a chlorine-containing solvent inert to sulfuric anhydride as a solvent may be considered, but in this case also a large amount of chlorine-containing waste solvent is generated. It's not environmentally friendly.

As described above, none of the known methods for producing sulfonic acid group-containing aromatic dihalides satisfy the above-mentioned environmental properties, reaction yields, and economics at the same time, and mass production and production cost reduction are possible. Development of a method for producing sulfonic acid group-containing aromatic dihalides has been awaited.
"Polymer", 1987, vol. 28, 1009. "Journal of Membrane Science", 83 (1993) 211-220. “Macromol. Chem. Phys.”, 199, 1421-1426 (1998). JP-T-2004-509224 JP-T-08-507301

  In view of the background of the prior art, the present invention provides a method for producing a sulfonic acid group-containing aromatic dihalide that is environmentally friendly because there are few by-products such as waste sulfuric acid and can be mass-produced and reduced in production cost. To do. The sulfonic acid group-containing aromatic dihalide is useful as a monomer of an aromatic polyether polymer suitable as a polymer electrolyte material.

  The present invention employs the following means in order to solve the above problems. That is, the method for producing a sulfonic acid group-containing aromatic dihalide of the present invention is characterized in that a sulfonation reaction is carried out by bringing an aromatic dihalide into contact with liquid sulfuric anhydride.

  According to the present invention, since there are few by-products such as waste sulfuric acid, it is environmentally friendly, and it is useful as a method for producing a sulfonic acid group-containing aromatic dihalide that can be mass-produced and reduced in production cost, and further useful as a polymer electrolyte material. A method for producing a sulfonic acid group-containing aromatic dihalide as a monomer of an aromatic polyether polymer can be provided.

  Hereinafter, the present invention will be described in detail.

  The present invention provides a sulfonic acid that is a monomer of an aromatic polyether polymer that is useful as a polymer electrolyte material because the above-mentioned problem, that is, there are few by-products such as waste sulfuric acid and mass production and production cost can be reduced. As a result of diligent investigations on the production method of the group-containing aromatic dihalide and contacting the aromatic dihalide with a specific liquid compound called liquid anhydrous sulfuric acid, it has been found that such problems can be solved at once.

  Unlike the conventional method, the method for producing a sulfonic acid group-containing aromatic dihalide of the present invention uses a specific agent called liquid sulfuric anhydride as a sulfonating agent, and hardly uses a solvent such as concentrated sulfuric acid. It has a feature that a sulfonic acid group-containing aromatic dihalide can be produced with little generation of waste sulfuric acid and / or inorganic salt after neutralization. In addition, by using sulfuric acid in a specific form of liquid state, the handling and the amount of charge can be easily adjusted, and the reactor can be simplified as compared with the case where conventional sulfuric anhydride is in a gaseous state. Even if it is a solid organic compound, it has achieved a dramatic effect that it can be reacted uniformly. In addition, the amount of concentrated sulfuric acid used can be greatly reduced, which greatly improves the yield that has been reduced so far when separating from by-products. This is the first time that a manufacturing method that can reduce production and manufacturing costs and has significant corporate value can be provided.

  In the present invention, liquid sulfuric anhydride means anhydrous sulfuric acid in a liquid state. Usually, anhydrous sulfuric acid is polymerized as it is to form an asbestos α-type or β-type and is generally solidified. However, in the present invention, it is difficult to polymerize by adding a small amount of a stabilizer. It is preferable to use γ-type sulfuric anhydride stabilized as described above. While α-type sulfuric anhydride has a melting point of 62 ° C or higher and β-type has 33 ° C, γ-type sulfuric anhydride has a low melting point of 17 ° C, so it can be used stably as a liquid at room temperature. It is. The type of the stabilizer is not particularly limited as long as it can prevent solidification of sulfuric anhydride, and dimethyl sulfate can be preferably used. Such liquid anhydrous sulfuric acid is not particularly limited as long as it is stable and liquid, but for example, Nisso Sulfan (registered trademark) manufactured by Nisso Metal Co., Ltd. is preferably used. it can.

  In the present invention, the amount of liquid sulfuric anhydride used is reduced from the amount of unreacted sulfuric anhydride and the amount of generated sulfuric acid and / or inorganic salt after neutralization is reduced. It is preferable to contact the liquid sulfuric anhydride in an amount of 0.9 mol or more and 1.3 mol or less with respect to 1 mol of the sulfonic acid group introduced into the solution. If the amount of liquid sulfuric anhydride used is less than 0.9 mol, the amount of raw material or by-product increases, and if the amount of liquid sulfuric anhydride used exceeds 1.3 mol, waste sulfuric acid and / or The inorganic salt after neutralization increases and side reactions occur, which is not preferable.

  In the present invention, the reaction temperature for carrying out the sulfonation reaction in the step of contacting with liquid sulfuric anhydride can be appropriately selected in consideration of the reactivity of the aromatic dihalide to be reacted. However, in consideration of the stability of liquid sulfuric anhydride, the sulfonation reaction is preferably performed at 20 ° C. or higher and 150 ° C. or lower. Furthermore, it is preferably 30 ° C. or higher and 120 ° C. or lower. In the present invention, it is preferable to add concentrated sulfuric acid. By adding concentrated sulfuric acid, the unreacted liquid sulfuric anhydride is converted to fuming sulfuric acid, the reactivity is lowered, the safety after the sulfonation reaction and the safety in the post-treatment process are improved, and the handling becomes easy. Further, by adding concentrated sulfuric acid, the fluidity of the reaction solution can be secured and workability such as drawing can be improved. The concentrated sulfuric acid is preferably used in a controlled amount of 1 mol or less, more preferably 0.3 mol or less, most preferably 0.1 mol or less with respect to 1 mol of the aromatic dihalide. From the viewpoint of the amount of waste sulfuric acid and / or the amount of inorganic salt produced after neutralization and the yield of the resulting sulfonic acid group-containing aromatic dihalide. When the amount of the concentrated sulfuric acid used exceeds 1 mol with respect to 1 mol of the aromatic dihalide, the amount of waste sulfuric acid and / or the amount of inorganic salt produced after neutralization is large, which not only increases the disposal cost. The sulfonic acid group-containing aromatic dihalide is not preferable because the yield is low and the price is high.

  In the present invention, when such concentrated sulfuric acid is added, liquid concentrated sulfuric acid may be solidified by adding concentrated sulfuric acid directly to liquid anhydrous sulfuric acid. Therefore, the aromatic dihalide is preferably brought into contact with liquid anhydrous sulfuric acid. Thereafter, a means for adding to concentrated sulfuric acid is preferably employed.

  The amount of concentrated sulfuric acid used is preferably a low amount controlled within a range of 0.001 mol or more and 0.3 mol or less with respect to 1 mol of liquid sulfuric anhydride.

  That is, when the concentrated sulfuric acid is less than 0.001 mol, the reaction mixture is solidified, or there is unreacted sulfuric anhydride, and when it comes in contact with moisture in the subsequent process, it generates heat rapidly. It is dangerous and undesirable. On the other hand, when the concentration of concentrated sulfuric acid exceeds 0.3 mol, the amount of waste sulfuric acid and / or inorganic salt after neutralization increases, which is not preferable from the viewpoint of environmental properties and disposal cost. From the standpoint of complete progress of the reaction and reduction of waste sulfuric acid, and prevention of solidification of the reaction system, the amount of concentrated sulfuric acid used is 0.01 mol or more and 0.1 mol or less with respect to 1 mol of liquid sulfuric anhydride. It is more preferable that it is within the range.

  In the present invention, the step of bringing into contact with the liquid sulfuric anhydride, and in addition to this, the step of neutralizing with an alkaline compound after the sulfonation reaction of the aromatic dihalide by the step of using concentrated sulfuric acid, and It is preferable to employ a method of further purifying the sulfonic acid group-containing aromatic dihalide obtained through the step of recrystallization with at least one selected from alcohol, water and aqueous alcohol.

Such alkaline compounds include sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, and the like, a -SO 3 _H group Any material can be used as long as it can be neutralized and converted into —SO ₃ Na group, —SO ₃ K group, and —SO ₃ Li. Such an alkaline compound is preferably added until the pH of the reaction mixture is around 7 while checking the pH of the reaction mixture with a pH test paper or the like.

  The recrystallization solvent used in the recrystallization step can be appropriately selected in consideration of the solubility of the sulfonic acid group-containing aromatic dihalide. In view of the solubility of the sulfonic acid group-containing aromatic dihalide and the by-product inorganic salt and the ease of crystallisation, alcohol and at least one solvent selected from water and a mixed aqueous solution of alcohol are preferably used. . Specific examples of such alcohols include methanol, ethanol, 1-propanol, 2-propanol, and the like, but can be appropriately selected and used in consideration of the solubility and crystallinity of the sulfonic acid group-containing aromatic dihalide. .

  The sulfonic acid group-containing aromatic dihalide obtained by the present invention may be an aromatic compound having two halogen atoms bonded to an aromatic ring and a sulfonic acid group, and by an aromatic nucleophilic substitution reaction with bisphenol. An aromatic dihalide capable of polymerization is preferred.

Here, in the present invention, the sulfonic acid group means a group represented by the following general formula (f1). However, this sulfonic acid group includes the case where the functional group (f1) forms a salt. Examples of the cation forming the salt include an arbitrary metal cation, NR ₄ ⁺ (R is an arbitrary organic group), and the like. In the case of such a metal cation, the valence can be used without any particular limitation. Specific examples of preferable metal ions include Li, Na, K, Rh, Mg, Ca, Sr, Ti, Al, Fe, Pt, Rh, Ru, Ir, and Pd. Among these, Na and K, which are inexpensive and do not adversely affect the solubility and can be easily proton-substituted, are more preferably used as the polymer electrolyte membrane. Two or more kinds of these cations can be contained in the sulfonic acid group-containing aromatic dihalide, and may be preferable by combining them.

  The sulfonic acid group-containing aromatic dihalide is represented by the compound represented by the following general formula (A1) and the following general formula (B1) from the viewpoint of polymerization activity and mechanical properties of the obtained polymer electrolyte material. Compounds are more preferred. Among these, from the viewpoint of raw material cost, a compound represented by the following general formula (A1) is more preferable.

(In formula (A1), X ₁ and X ₂ are halogen, Y is a group selected from —CO—, —SO ₂ — and —PORp— (Rp is an arbitrary organic group), M ¹ and M ² are H , A group selected from a metal cation and an ammonium cation, a1 and a2 each represent an integer of 0 to 4, and are not simultaneously 0. The compound represented by the formula (A1) may be further optionally substituted.)

(In Formula (B1), X ₃ and X ₄ are halogen, Rf ¹ and Rf ² are perfluoroalkyl groups having 1 to 12 carbon atoms, Ar ¹ is a divalent group having an aromatic ring, and M ^{3 to} M ⁵ are A group selected from H, a metal cation, and an ammonium cation, and a3 to a5 represent an integer of 0 to 4 that is not 0. The compound represented by the formula (B1) may be further substituted.
Specific examples of the sulfonic acid group-containing aromatic dihalide represented by the formula (A1) include 3,3′-disulfonate-4,4′-dichlorodiphenylsulfone, 3,3′-disulfonate— 4,4′-difluorodiphenyl sulfone, 3,3′-disulfonate-4,4′-dichlorodiphenyl ketone, 3,3′-disulfonate-4,4′-difluorodiphenyl ketone, 3,3′-disulfonate -4,4'-dichlorodiphenylphenylphosphine oxide, 3,3'-disulfonate-4,4'-difluorodiphenylphenylphosphine oxide, and the like. Among these, Y is —CO—, that is, 3, 3 from the viewpoint of the hot water resistance, hot methanol resistance, and fuel crossover suppression effect of the aromatic polyether polymer obtained from the sulfonic acid group-containing aromatic dihalide. '-Disulfonate-4,4'-dichlorodiphenyl ketone and 3,3'-disulfonate-4,4'-difluorodiphenyl ketone are more preferable, and Y is —CO—, X ₁ and X ₂ from the viewpoint of polymerization activity. Is most preferably F, ie 3,3′-disulfonate-4,4′-difluorodiphenyl ketone.

  These sulfonic acid groups are preferably salted with a monovalent cationic species during polymerization. The monovalent cation species may be sodium, potassium, other metal species, various amines, or the like, but is not limited thereto. These sulfonic acid group aromatic active dihalide compounds can be used alone, but a plurality of sulfonic acid group aromatic active dihalide compounds can also be used in combination.

  Examples of the use of the sulfonic acid group-containing aromatic dihalide obtained by the present invention include, but are not limited to, chemicals such as various monomers, additives, and surfactants, and precursors thereof. . Among these, a monomer use is preferable, and a use as a monomer for producing an aromatic polyether polymer is more preferable.

  Such an aromatic polyether polymer refers to a polymer mainly composed of an aromatic ring and containing an ether bond as a mode in which the aromatic ring units are connected. In addition to the ether bond, there may be a bond mode generally used for forming an aromatic polymer such as a direct bond, ketone, sulfone, sulfide, various alkylenes, imides, amides, esters, and urethanes. The ether bond is preferably at least one per repeating unit of the main constituent component. The aromatic ring may include not only a hydrocarbon aromatic ring but also a hetero ring. Further, a part of the aliphatic units may constitute a polymer together with the aromatic ring unit. Aromatic units include hydrocarbon groups such as alkyl groups, alkoxy groups, aromatic groups, aryloxy groups, halogen groups, nitro groups, cyano groups, amino groups, halogenated alkyl groups, carboxyl groups, phosphonic acid groups, hydroxyl groups, etc. And may have an arbitrary substituent.

  Examples of a method for synthesizing an aromatic polyether polymer using a sulfonic acid group-containing aromatic dihalide obtained by the present invention include bisphenol, a sulfonic acid group-containing aromatic dihalide and / or an aromatic dihalide not containing a sulfonic acid group. It can be synthesized using the aromatic nucleophilic substitution reaction.

  Further, the bisphenol used together with the sulfonic acid group-containing aromatic dihalide obtained by the present invention is particularly limited as long as it can be increased in molecular weight by an aromatic nucleophilic substitution reaction with the aromatic dihalide. Instead, two or more bisphenols can be used in combination. Moreover, what introduce | transduced the ionic group into these aromatic dihydroxy compounds can also be used as a monomer.

  In addition, halogenated aromatic hydroxy compounds can also be used without particular limitation, and specific examples include 4-hydroxy-4′-chlorobenzophenone, 4-hydroxy-4′-fluorobenzophenone, 4-hydroxy-4. '-Chlorodiphenylsulfone, 4-hydroxy-4'-fluorodiphenylsulfone, 4- (4'-hydroxybiphenyl) (4-chlorophenyl) sulfone, 4- (4'-hydroxybiphenyl) (4-fluorophenyl) sulfone, Examples include 4- (4′-hydroxybiphenyl) (4-chlorophenyl) ketone, 4- (4′-hydroxybiphenyl) (4-fluorophenyl) ketone, and the like. These can be used alone or in a mixture of two or more. Furthermore, in the reaction of the activated dihalogenated aromatic compound and the aromatic dihydroxy compound, these halogenated aromatic hydroxy compounds may be reacted together to synthesize an aromatic polyether polymer.

  In the polymerization by the aromatic nucleophilic substitution reaction performed using the sulfonic acid group-containing aromatic dihalide obtained by the present invention, a polymer can be obtained by reacting the monomer mixture in the presence of a basic compound. The polymerization reaction can be carried out in the temperature range of 0 to 350 ° C, but is preferably 50 to 250 ° C. When the temperature is lower than 0 ° C., the reaction does not proceed sufficiently, and when the temperature is higher than 350 ° C., the polymer tends to be decomposed.

  Such a polymerization reaction can be carried out in the absence of a solvent, but is preferably carried out in a solvent. As such a solvent, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethyl sulfoxide, diphenyl sulfone, sulfolane, 1,3-dimethyl-2-imidazolidinone and the like are used. However, the present invention is not limited to these, and any material that can be used as a stable solvent in the aromatic nucleophilic substitution reaction may be used. These organic solvents may be used alone or as a mixture of two or more.

  Examples of the basic compound include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, and the like, as long as aromatic diols can be converted into an active phenoxide structure. It can use without being limited to these. In the aromatic nucleophilic substitution reaction to be reacted in the presence of such a basic compound, water may be generated as a by-product. In this case, toluene or the like can coexist in the reaction system, and water can be removed from the system as an azeotrope. As a method for removing water out of the system, a water-absorbing agent such as molecular sieve can also be used.

  When this aromatic nucleophilic substitution reaction is carried out in a solvent, it is preferable to charge the monomer so that the resulting polymer concentration is 5 to 50% by weight. When the polymer concentration is less than 5% by weight, the degree of polymerization tends to be difficult to increase. On the other hand, when the polymer concentration is more than 50% by weight, the reaction system becomes too viscous and the reaction product is post-treated. Tend to be difficult. After completion of the polymerization reaction, the solvent is removed from the reaction solution by evaporation, and the residue is washed as necessary to obtain the desired polymer. In addition, the polymer can be obtained by precipitating the polymer as a solid by adding the reaction solution in a solvent having low polymer solubility, and collecting the precipitate by filtration.

  The weight average molecular weight of the aromatic polyether polymer obtained using the sulfonic acid group-containing aromatic dihalide obtained by the present invention is preferably 50,000 to 1,000,000, more preferably 100,000 to 600,000. is there. If the weight average molecular weight is less than 50,000, mechanical properties such as cracks and pinholes may be insufficient when the electrolyte membrane is used for a long period of time. In some cases, the solution viscosity is too high and the processability is poor.

  If the purity of raw material monomers such as sulfonic acid group-containing aromatic dihalide obtained in accordance with the present invention, and bisphenol used in combination and aromatic dihalide not containing sulfonic acid group is high enough not to impair the purpose of the present invention, there is a problem. However, it is preferably 98% or more, more preferably 99% or more.

  The method for analyzing the purity of the sulfonic acid group-containing aromatic dihalide obtained by the present invention is not particularly limited, but the combined use of capillary electrophoresis (CE) and ion chromatography (IC) is preferred. CE analysis can mainly check the purity and impurities of organic compounds. For example, using UV detector, fused silica as capillary, measurement under conditions of electrophoretic solution boric acid (pH 9) and positive applied voltage. It can be carried out. In IC analysis, the purity and impurities of inorganic compounds can be mainly confirmed. For example, an anion can be measured with an eluent KOH gradient and a cation can be measured with an eluent methanesulfonic acid. Examples of the method for confirming the chemical structure of the sulfonic acid group-containing aromatic dihalide obtained by the present invention include infrared absorption spectrum (IR) and nuclear magnetic resonance spectrum (NMR).

  The aromatic polyether polymer obtained by using the sulfonic acid group-containing aromatic dihalide obtained by the present invention can be applied to various uses. For example, it can be applied to medical applications such as extracorporeal circulation columns and artificial skin, applications for filtration, ion exchange resin applications, various structural materials, and electrochemical applications. Among them, it can be preferably used for various electrochemical applications. Examples of the electrochemical application include a fuel cell, a redox flow battery, a water electrolysis device, a chloroalkali electrolysis device, etc. Among them, the fuel cell is the most preferable use. Furthermore, among fuel cells, it is suitable for a polymer electrolyte material for a polymer electrolyte fuel cell, and there are those using hydrogen as a fuel and those using an organic compound such as methanol as the fuel. It is particularly preferably used for a direct fuel cell using at least one selected from organic compounds of -6 and a mixture of these with water as fuel. As this C1-C6 organic compound, C1-C3 alcohols, such as methanol, ethanol, and isopropyl alcohol, and dimethyl ether are preferable, and methanol is used most preferably.

  When the aromatic polyether polymer obtained by using the sulfonic acid group-containing aromatic dihalide obtained by the present invention is used for a fuel cell, it is usually used in a membrane state. However, the polymer electrolyte material of the present invention is not limited to a shape such as a membrane shape, and the shape may be a plate shape, a fiber shape, a hollow fiber shape, a particle shape, a lump shape, etc. in addition to the above-described film shape. Depending on the intended use, it can take various forms.

  The method for forming the polymer electrolyte material of the present invention into a film is not particularly limited, but a method of forming a film from a solution state, a method of forming a film from a molten state, or the like is employed.

  In the former, for example, a method of forming a film by dissolving the polymer electrolyte material in a solvent such as N, N-dimethylacetamide, casting the solution on a glass plate or the like, and removing the solvent is exemplified. it can. The solvent used for the film formation is not particularly limited as long as it dissolves the aromatic polyether polymer and can be removed thereafter. For example, N, N-dimethylacetamide, N, N-dimethylformamide, N-methyl Aprotic polar solvents such as 2-pyrrolidone, dimethyl sulfoxide, sulfolane, 1,3-dimethyl-2-imidazolidinone, hexamethylphosphontriamide, ester solvents such as γ-butyrolactone, butyl acetate, ethylene carbonate, propylene Carbonate solvents such as carbonate, alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, or isoprene Alcohol solvents such as propanol, water and mixtures thereof is preferably used, most soluble aprotic polar solvent is high are preferably used.

  The polymer electrolyte membrane made of an aromatic polyether polymer obtained by using the sulfonic acid group-containing aromatic dihalide obtained by the present invention may further crosslink the polymer structure by means such as radiation irradiation as necessary. You can also. By crosslinking such a polymer electrolyte membrane, an effect of further suppressing fuel crossover and swelling with respect to the fuel can be expected, and the mechanical strength may be improved, which may be more preferable. As the type of radiation irradiation, for example, electron beam irradiation or γ-ray irradiation can be employed.

  As the film thickness of the polymer electrolyte membrane made of an aromatic polyether polymer obtained by using the sulfonic acid group-containing aromatic dihalide obtained by the present invention, a film having a thickness of 1 to 2000 μm is preferably used. A thickness of more than 1 μm is more preferable for obtaining the strength of a film that can withstand practical use, and a thickness of less than 2000 μm is preferable for reducing the film resistance, that is, improving the power generation performance. A more preferable range of the film thickness is 3 to 500 μm, and a particularly preferable range is 5 to 250 μm. The film thickness can be controlled by the solution concentration or the coating thickness on the substrate.

  In addition, a polymer electrolyte membrane comprising an aromatic polyether polymer obtained by using the sulfonic acid group-containing aromatic dihalide obtained by the present invention has a plasticizer, a stabilizer or an ordinary polymer compound. Additives such as mold release agents can be added within a range that does not contradict the purpose of the present invention.

  In addition, the polymer electrolyte membrane composed of an aromatic polyether polymer obtained by using the sulfonic acid group-containing aromatic dihalide obtained by the present invention is within a range that does not adversely affect the above-mentioned properties. Various polymers, elastomers, fillers, fine particles, various additives, and the like may be included for the purpose of improving mechanical strength, thermal stability, processability, and the like.

  Furthermore, the application of the polymer electrolyte fuel cell using the aromatic polyether polymer obtained by using the sulfonic acid group-containing aromatic dihalide obtained by the present invention is not particularly limited, but the power supply of the mobile body A source is preferred. In particular, mobile devices such as mobile phones, personal computers, PDAs, televisions, radios, music players, digital cameras, video cameras, game machines, headsets, DVD players, various robots such as industrial humanoids and animal types, vacuum cleaners, etc. It is preferably used as a power supply source for automobiles such as home appliances, passenger cars, buses, trucks, and mobiles such as ships and railways.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these. In addition, the measurement conditions of each physical property are as follows.

(1) Purity analysis of sulfonic acid group-containing dihalide Purity analysis of sulfonic acid group-containing dihalide was measured by capillary electrophoresis (CE) and ion chromatography (IC) under the following measurement conditions, and the purity was calculated. The sample was prepared by diluting with pure water.

  CE analysis uses fused silica as a capillary, and the measurement is performed under conditions of electrophoretic boric acid (pH 9), applied voltage positive (20 kV), UV detector (195 nm), and the purity is the percentage of the area of the detected peak (%). Calculated with

  In addition, IC analysis uses DX-500 made by DIONEX, the anion is Ion Pac AG11HC + Ion Pac AS11HC, the eluent is KOH 1 to 35 mM gradient, the detector is electric conductivity, the cation is Ion Pac CG14 + Ion Pac CS14, eluent was 10 mM methanesulfonic acid solution, detector was measured under the conditions of electric conductivity, and purity was calculated by weight%.

(2) Nuclear magnetic resonance spectrum (NMR)
NMR measurement was performed under the following measurement conditions, and the structure of the sulfonic acid group-containing dihalide was confirmed.

Device: EX-270
Resonance frequency: 270 MHz ( ¹ H-NMR)
Measurement temperature: room temperature Dissolving solvent: DMSO-d6
Internal reference material: TMS (0 ppm)
Integration count: 16 times Example 1
As a sulfonating agent, disodium 3,3′-disulfonate-4,4′-difluorobenzophenone represented by the following formula (G1) was synthesized using liquid sulfuric anhydride.

  A 3 L vertical separable flask equipped with a Pyrex (registered trademark) glass stirring blade, reflux condenser and 200 mL dropping funnel was purged with nitrogen, and 4,4′-difluorobenzophenone (Aldrich reagent, purity 99.9%) 500 .2 g (2.290 mol) was charged, and while gently stirring, 371.5 g (4.644 mol, sulfonic acid group to be introduced) of liquid sulfuric anhydride (manufactured by Nisso Metal Co., Ltd., trade name “Nisso Sulfan”) 1.014 mol per 1 mol) was added dropwise over 100 minutes, and after completion of the addition, the reaction was carried out at 120 ° C. for 24 hours. It was a brown viscous liquid. Thereafter, 11.9 g of concentrated sulfuric acid (0.121 mol, 0.053 mol based on 1 mol of 4,4′-difluorobenzophenone which is an aromatic dihalide), followed by 395 mL of water and an aqueous NaOH solution (207.5 g ( 5.188 mol) of NaOH and 1264 mL of water) was added to neutralize. The slurry was easy to handle.

Next, the obtained slurry was transferred to a 10 L flask together with 273 mL of washing water, ethanol 3864 mL (total ethanol / water = 2/1) was added, and the mixture was dissolved by heating at 84 ° C. Next, after hot filtration, the mixture is left still at 4 ° C. for 1 day, filtered, washed with ethanol, vacuum dried at 120 ° C., and disodium 3,3′-disulfonate represented by the above formula (G1). 918.5 g of 4,4′-difluorobenzophenone was obtained (yield 95%). The purity of the obtained compound was 98.5% from CE and IC. As impurities, 0.13% of Na ₂ SO ₄ from IC and 1.4% of organic impurities from CE were observed. The structure was confirmed by ¹ H-NMR spectrum.

  Yield is high and waste sulfuric acid and by-product inorganic salts are hardly generated, so it is environmentally friendly, the disposal cost is low, and it is suitable for mass synthesis and production cost reduction.

Example 2
The method described in Example 1 except that the addition amount of concentrated sulfuric acid was changed to 44.9 g (0.458 mol, 0.2 mol with respect to 1 mol of 4,4′-difluorobenzophenone which is an aromatic dihalide). Similarly, disodium 3,3′-disulfonate-4,4′-difluorobenzophenone represented by the above formula (G1) was synthesized. The yield was 92%. Yield is high and waste sulfuric acid and by-product inorganic salts are hardly generated, so it is environmentally friendly, the disposal cost is low, and it is suitable for mass synthesis and production cost reduction.

Comparative Example 1
Using fuming sulfuric acid as a sulfonating agent, disodium 3,3′-disulfonate-4,4′-difluorobenzophenone represented by the following formula (G1) was synthesized.

This was performed based on the method described in “Macromol. Chem. Phys.”, 199, 1421-1426 (1998). That is, a 5 L vertical separable flask equipped with a Teflon (registered trademark) stirring blade and a reflux condenser was purged with nitrogen, and 1,226 g (5.62) of 4,4′-difluorobenzophenone (Aldrich reagent, purity 99.9%). Mole), and while gently stirring, 3500 g of fuming sulfuric acid (50% SO ₃ , Wako Pure Chemical Reagent) (1.94 mol per mol of sulfonic acid group introduced at 21.86 mol of SO ₃ , H ₂ SO ₄ was added slowly 3.17 mol) relative to 4,4'-difluorobenzophenone 1 mole of an aromatic dihalide in 17.84 molar. The reaction was carried out at 100 ° C. for 19 hours. It was a brown viscous liquid. Thereafter, the solution was poured little by little into 11 kg of water and neutralized with 2760 g of NaOH until the pH became 7, and then 1000 g of sodium chloride was added to precipitate the composite.

The resulting white precipitate was filtered off, recrystallized with 6.5 L of an aqueous ethanol solution (ethanol / water = 2/1), and disodium 3,3′-disulfonate-4,4 represented by the above formula (G1). 1279 g of '-difluorobenzophenone was obtained. The purity of the obtained compound was 99.3% from CE and IC. As impurities, 0.19% of Na ₂ SO ₄ from IC and 0.5% of organic impurities from CE were observed. The structure was confirmed by ¹ H-NMR spectrum.

  Compared to Example 1, the yield is low, and since it contains a large amount of waste sulfuric acid, by-product inorganic salts, and salt for salting out, it is not environmentally friendly, the disposal cost is high, and the mass synthesis and production costs are reduced. It was not suitable for.

  The sulfonic acid group-containing aromatic dihalide obtained by the present invention is useful as a polymer electrolyte material, and can be applied to various electrochemical devices (for example, a fuel cell, a water electrolysis device, a chloroalkali electrolysis device, etc.). Among these devices, it is suitable for a fuel cell, and particularly suitable for a fuel cell using a methanol aqueous solution as a fuel.

The use of the polymer electrolyte fuel cell using the aromatic polyether-based polymer obtained by using the sulfonic acid group-containing aromatic dihalide obtained by the present invention is not particularly limited, but includes a mobile phone, a personal computer, a PDA, Mobile devices such as video cameras, digital cameras, TVs, radios, music players, game machines, headsets, DVD players, various robots such as industrial humanoids and animal types, home appliances such as cordless vacuum cleaners, toys, electric bicycles, It is preferably used as a power supply source for vehicles such as motorcycles, automobiles, buses, trucks, etc., moving bodies such as ships and railways, conventional primary batteries such as stationary generators, alternative to secondary batteries, or a hybrid power source with these. It is done.

Claims (10)

A method for producing a sulfonic acid group-containing aromatic dihalide, wherein a sulfonation reaction is carried out by contacting an aromatic dihalide with liquid sulfuric anhydride. 2. The sulfone according to claim 1, wherein the liquid sulfuric acid is brought into contact with 0.9 mol to 1.3 mol of 1 mol of the sulfonic acid group introduced into the aromatic dihalide. A method for producing an acid group-containing aromatic dihalide. Concentrated sulfuric acid is added, The manufacturing method of the sulfonic acid group containing aromatic dihalide of Claim 1 or 2 characterized by the above-mentioned. 4. The method for producing a sulfonic acid group-containing aromatic dihalide according to claim 3, wherein concentrated aromatic sulfuric acid is added after the aromatic dihalide is brought into contact with liquid sulfuric anhydride. The sulfonic acid group-containing aromatic dihalide according to claim 3 or 4, wherein the concentrated sulfuric acid is added within a range of 0.001 mol to 0.3 mol with respect to 1 mol of the liquid sulfuric anhydride. Manufacturing method. 6. The method according to claim 1, wherein after the sulfonation reaction, the step of neutralizing with an alkaline compound and the step of recrystallization with at least one selected from alcohol, water and an aqueous alcohol solution are passed. A process for producing a sulfonic acid group-containing aromatic dihalide according to claim 1. The method for producing a sulfonic acid group-containing aromatic dihalide according to any one of claims 1 to 6, wherein the sulfonic acid group-containing aromatic dihalide is a compound represented by the following general formula (A1).

(In formula (A1), X ₁ and X ₂ are halogen, Y is a group selected from —CO—, —SO ₂ — and —PORp— (Rp is an arbitrary organic group), M ¹ and M ² are H , A group selected from a metal cation and an ammonium cation, a1 and a2 each represent an integer of 0 to 4, and are not simultaneously 0. The compound represented by the formula (A1) may be further optionally substituted.) In formula (A1), Y is -CO-, sulfonic acid group-containing aromatic dihalide method according to claim 7, characterized in that _{X 1} and _{X 2} are F. The method for producing a sulfonic acid group-containing aromatic dihalide according to any one of claims 1 to 8, wherein the sulfonic acid group-containing aromatic dihalide is used as a monomer of an aromatic polyether polymer. . The method for producing a sulfonic acid group-containing aromatic dihalide according to claim 9, wherein the aromatic polyether polymer is used for a polymer electrolyte material.