Method for producing fluorine-containing vinyl sulfonic acid fluoride or fluorine-containing vinyl sulfonate salt, and method for separating same

Abstract

To provide a method for producing fluorine-containing vinyl sulfonic acid fluoride and / or fluorine-containing vinyl sulfonate in high yield.SOLUTION: A method for producing fluorine-containing vinyl sulfonic acid fluoride and / or fluorine-containing vinyl sulfonate is provided. In a reaction between a fluorine-containing vinyl sulfonic acid anhydride (1) represented by general formula (1) and an alkali metal fluoride, the alkali metal fluoride is added to the fluorine-containing vinyl sulfonic acid anhydride (1) under heating. (In general formula (1), m is an integer of 0-3 and n is an integer of 1-6.)SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing fluorinated vinyl sulfonic acid fluoride or a fluorinated vinyl sulfonate salt, and a separation method thereof. It also relates to a method for reusing compounds used in the separation method. [Background technology]

[0002] Fluorine-containing polymer electrolytes (5) represented by the following general formula (5) have been mainly used as main components of membranes for fuel cells, catalyst binder polymers for fuel cells, membranes for salt electrolysis, and the like. [ka] (p is an integer between 0 and 6, and q is an integer between 1 and 6) It is known that a fluorine-containing polymer electrolyte represented by the general formula (5) can be produced by subjecting a copolymer of fluorine-containing vinylsulfonic acid fluoride (6) represented by the following general formula (6) and tetrafluoroethylene (TFE) to a saponification reaction and an acid treatment. [ka] (p is an integer between 0 and 6, and q is an integer between 1 and 6) As a method for producing the fluorine-containing vinyl sulfonic acid fluoride (6) represented by the above general formula (6), a method for producing a fluorine-containing vinyl sulfonic acid fluoride (6) represented by the following general formula (1): [ka] (In the formula, m is an integer of 0 to 3, and n is an integer of 1 to 6). A fluorine-containing vinyl sulfonic anhydride (1) represented by the formula: a fluorinating agent which is one or more selected from the group consisting of hydrogen fluoride, a metal fluoride, a quaternary ammonium fluoride, and a quaternary phosphonium fluoride; By contacting and mixing, the compound represented by the following general formula (3): [ka] (In the formula, m is an integer of 0 to 3, and n is an integer of 1 to 6). Patent Document 1 discloses a method for producing a fluorine-containing vinyl sulfonic acid fluoride (3) represented by the following general formula (4): [ka] (In the formula, m is an integer of 0 to 3, n is an integer of 1 to 6, M 2 is Li, Na, K, Rb, or Cs. It is disclosed that it is possible to produce a fluorine-containing vinyl sulfonate (4) represented by the following formula: Furthermore, a method for producing the fluorine-containing vinyl sulfonate (3) by reusing the fluorine-containing vinyl sulfonate (4) is also disclosed. It is also disclosed that the fluorine-containing vinyl sulfonate (4) can be converted to the fluorine-containing vinyl sulfonate (3) by a different method, and it is known to be a useful compound (Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2020 / 012913 [Patent Document 2] U.S. Pat. No. 3,560,568 Summary of the Invention [Problem to be solved by the invention]

[0004] Although Patent Document 1 discloses a method for producing fluorinated vinylsulfonic acid fluoride (3) and fluorinated vinylsulfonate (4) in which m=0 and n=2 by reacting fluorinated vinylsulfonic acid anhydride (1) in which m=0 and n=2 with sodium fluoride or potassium fluoride, there is a demand for a production method for obtaining fluorinated vinylsulfonic acid fluoride (3), which is a raw material for the above-mentioned fluorine-based polymer electrolyte (5), in a higher yield. There is also a demand for a method for separating fluorinated vinylsulfonic acid fluoride (3) and fluorinated vinylsulfonate (4). [Means for solving the problem]

[0005] As a result of intensive research aimed at solving the above-mentioned problems, the present inventors have found that the above-mentioned object can be achieved by adding an alkali metal fluoride (2) to a fluorine-containing vinyl sulfonic anhydride (1) under heating in the reaction between the fluorine-containing vinyl sulfonic anhydride (1) and the alkali metal fluoride (2), and have thus completed the present invention. In addition, they have also found a method for separating the fluorine-containing vinyl sulfonic acid fluoride (3) and the fluorine-containing vinyl sulfonate (4), and a method for reusing the compounds and the like used in the separation.

[0006] That is, the present invention is as follows. [1] The following general formula (3): [ka] (In the formula, m is an integer of 0 to 3, and n is an integer of 1 to 6). Fluorine-containing vinyl sulfonic acid fluoride (3) represented by the formula: and / or The following general formula (4): [ka] In the formula, m is an integer of 0 to 3, n is an integer of 1 to 6, and M is K, Rb, or Cs. The present invention relates to a method for producing a fluorine-containing vinyl sulfonate (4) represented by the following formula: The following general formula (1): [ka] (In the formula, m is an integer of 0 to 3, and n is an integer of 1 to 6). A fluorine-containing vinyl sulfonic anhydride (1) represented by the formula: The following general formula (2): Midfielder (2) (In the formula, M is K, Rb, or Cs.) In the reaction with an alkali metal fluoride (2) represented by An alkali metal fluoride (2) is added to a fluorine-containing vinyl sulfonic anhydride (1) under heating. A manufacturing method comprising: [2] The production method according to [1], wherein the reaction temperature is 60 to 250°C. [3] The production method according to [1] or [2], wherein a ratio (β / α) of the amount of substance (β) of the alkali metal fluoride (2) to the amount of substance (α) of the fluorinated vinyl sulfonic anhydride (1) is 1 to 100. [4] The following general formula (3): [ka] (In the formula, m is an integer of 0 to 3, and n is an integer of 1 to 6). The method according to [1], which is a method for producing a fluorinated vinyl sulfonic acid fluoride (3) represented by the following formula: [5] The following general formula (4): [ka] (In the formula, m is an integer of 0 to 3, n is an integer of 1 to 6, and M is K, Rb, or Cs.) The method for producing a fluorine-containing vinyl sulfonate (4) represented by the following formula (1): [6] The method according to [1], further comprising a step of separating the fluorinated vinyl sulfonic acid fluoride (3). [7] The method according to [6], comprising a step of distilling the fluorine-containing sulfonic acid fluoride (3). [8] The production method according to [6], comprising a step of mixing the fluorine-containing sulfonic acid fluoride (3) with an extraction compound. [9] The method according to [8], wherein the extract compound is at least one compound selected from the group consisting of water, an aqueous solution containing an inorganic salt, an alcohol compound, an amide compound, and a sulfo compound.

[10] The manufacturing method according to [9], wherein the inorganic salt-containing aqueous solution is an aqueous solution containing at least one inorganic salt compound selected from the group consisting of carbonates, sulfates, thiosulfates, acetates, phosphates, citrates, tartrates, and tetraborates.

[11] The production method according to [8], wherein the ratio (ζ / ε) of the mass (ζ) of the extracted compound to the mass (ε) of the fluorine-containing sulfonic acid fluoride (3) is 0.1 to 100.

[12] The production method according to [8], comprising a step of allowing the mixed solution obtained in the step of mixing the fluorine-containing sulfonic acid fluoride (3) with the extract compound to stand and separating it into a phase containing the fluorine-containing sulfonic acid fluoride (3) and a phase containing the extract compound.

[13] The method according to

[12] , wherein the phase containing the extracted compound is reused in the step of mixing the fluorinated sulfonic acid fluoride (3) with the extracted compound.

[14] The production method according to

[12] , comprising a step of separating the fluorine-containing sulfonic acid fluoride (3) from the phase containing the fluorine-containing sulfonic acid fluoride (3) by distillation.

[15] The method according to [1], further comprising a step of separating the reaction residue.

[16] The production method according to

[15] , comprising a step of mixing the reaction residue with a dissolving compound to prepare a fluorine-containing sulfonate solution.

[17] The method according to

[16] , wherein the dissolving compound is at least one compound selected from the group consisting of ether compounds, ketone compounds, ester compounds, carbonate compounds, and nitrile compounds.

[18] The production method according to

[16] , wherein a ratio (δ / γ) of a mass (δ) of the dissolved compound to a mass (γ) of the reaction residue is 0.01 to 100.

[19] The method according to

[16] , further comprising a step of filtering the solution of the fluorinated sulfonate to obtain a filtrate containing the fluorinated sulfonate.

[20] The method according to

[16] , comprising a step of filtering the fluorine-containing sulfonate solution to obtain a filtrate containing the alkali metal fluoride (2). [twenty one] The production method according to

[20] , wherein the filtrate containing the alkali metal fluoride (2) is reused in the reaction of the fluorine-containing vinyl sulfonic anhydride (1) with the alkali metal fluoride (2). [twenty two] The production method according to

[19] , comprising a step of separating a volatile component containing the dissolved compound from the fluorinated sulfonate-containing filtrate to obtain the fluorinated vinyl sulfonate (4). [twenty three] The production method according to

[22] , wherein the volatile components containing the dissolved compound are reused in the step of mixing the reaction residue with the dissolved compound and preparing a fluorine-containing sulfonate solution. [twenty four] The method according to

[19] , comprising a step of adding water to the filtrate containing the fluorine-containing sulfonate and mixing the same. [twenty five] The production method according to

[24] , wherein a ratio (κ / ι) of the mass (ι) of the fluorine-containing sulfonate-containing filtrate to the total mass (κ) of the water is 0.1 to 100.

[26] The production method according to

[24] , further comprising a step of adding water to the fluorine-containing sulfonate-containing filtrate, and separating a volatile component containing the dissolved compound from the solution obtained by the step of mixing, thereby preparing an aqueous solution containing a fluorine-containing sulfonate.

[27] The production method according to

[26] , further comprising a step of separating volatile components containing the dissolved compounds from a solution obtained by a step of adding water to and mixing the fluorine-containing sulfonate-containing filtrate, and separating water from the volatile components containing the dissolved compounds separated in the step of preparing an aqueous solution containing a fluorine-containing sulfonate.

[28] The production method according to

[26] or

[27] , wherein the volatile components containing the dissolved compound are recycled to the step of mixing the reaction residue with the dissolved compound and preparing a fluorine-containing sulfonate solution.

[29] The production method according to

[24] , wherein a volatile component containing the dissolved compound is separated from a solution obtained by a step of adding water to the fluorine-containing sulfonate-containing filtrate and mixing, and the water separated in a step of separating water from the volatile component containing the dissolved compound separated in the step of preparing an aqueous solution containing a fluorine-containing sulfonate is reused in the step of adding water to the fluorine-containing sulfonate-containing filtrate and mixing. Effect of the Invention

[0007] According to the present invention, fluorine-containing vinyl sulfonic acid fluoride (3) can be produced in a high yield. Also, fluorine-containing vinyl sulfonate (4) can be produced. Furthermore, fluorine-containing vinyl sulfonic acid fluoride (3) and fluorine-containing vinyl sulfonate (4) can be separated, and the compounds obtained by the above separation can be reused. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention (hereinafter, referred to as the present embodiment) will be described in detail. However, the present invention is not limited to the present embodiment, and can be modified in various ways within the scope of the present invention.

[0009] The production method of this embodiment is a method for producing a compound represented by the following general formula (3): [ka] (In the formula, m is an integer of 0 to 3, and n is an integer of 1 to 6). Fluorine-containing vinyl sulfonic acid fluoride (3) represented by the formula: and / or The following general formula (4): [ka] In the formula, m is an integer of 0 to 3, n is an integer of 1 to 6, and M is K, Rb, or Cs. The present invention relates to a method for producing a fluorine-containing vinyl sulfonate (4) represented by the following formula: The following general formula (1): [ka] In the formula, m is an integer of 0 to 3, and n is an integer of 1 to 6. A fluorine-containing vinyl sulfonic anhydride (1) represented by the formula: The following general formula (2): Midfielder (2) (In the formula, M is K, Rb, or Cs.) In the reaction with an alkali metal fluoride (2) represented by This method comprises adding an alkali metal fluoride (2) to a fluorine-containing vinyl sulfonic anhydride (1) under heating.

[0010] In this specification, the above-mentioned fluorine-containing vinyl sulfonic anhydride (1) may be referred to as "compound (1)", the above-mentioned alkali metal fluoride (2) as "compound (2)", the above-mentioned fluorine-containing vinyl sulfonic acid fluoride (3) as "compound (3)", and the above-mentioned fluorine-containing vinyl sulfonate (4) as "compound (4)". The reaction conditions and the like for producing compound (1), compound (2), and compound (3) and / or compound (4) will be described in detail below.

[0011] <Fluorine-containing vinyl sulfonic anhydride (1) (compound (1))> The fluorine-containing vinyl sulfonic anhydride (1) is represented by the following general formula (1): [ka] (In the formula, m is an integer of 0 to 3, and n is an integer of 1 to 6). It is expressed as: The fluorine-containing vinyl sulfonic anhydride (1) may be used alone or in combination of two or more kinds.

[0012] As m, an integer of 0 to 1 is preferable, and 0 is more preferable, since it is easily available or produced and tends to be economical. As n, 1 to 4 is preferable, 2 to 4 is more preferable, and 2 is even more preferable, because n is easily available or produced and tends to be economical. As a combination of m and n, m=0 and n=2 are particularly preferable.

[0013] The method for producing the fluorine-containing vinyl sulfonic anhydride (1) is not particularly limited, and can be produced by a conventionally known method. For example, it can be produced by the method described in International Publication No. 2020 / 012913.

[0014] <Alkali metal fluoride (2) (compound 2)> The alkali metal fluoride (2) is represented by the following general formula (2): Midfielder (2) (In the formula, M is K, Rb, or Cs.) It is expressed as: The alkali metal fluorides (2) may be used alone or in combination of two or more.

[0015] As M, K or Cs is more preferable since it is easily available and tends to be economical, and K is further preferable from the same viewpoint.

[0016] Compound (2) having a reduced water content can also be used, if necessary. The method for reducing the water content of compound (2) is not particularly limited as long as it is a commonly available method, and examples of the method include a method of heating, a method of heating under vacuum, and a method of heating under a dry gas flow. The heating temperature is not particularly limited as long as it is a temperature that can reduce the water content of compound (2), but since there is a tendency to suppress decomposition of compound (2), it is preferably 600°C or less. Since excessive heating is suppressed and there is a tendency to be more economical, it is more preferably 300°C or less, and from the same viewpoint, it is even more preferably 250°C or less, and particularly preferably 200°C or less. Furthermore, since there is a tendency to promote reduction of the water content, it is preferably 100°C or more, more preferably 120°C or more, and even more preferably 150°C or more. The dry gas is not particularly limited as long as it is a commonly used dry gas, and examples of the dry gas include dry air and dry nitrogen.

[0017] When reacting the fluorine-containing vinyl sulfonic anhydride (1) with the alkali metal fluoride (2), additives such as ether compounds, nitrile compounds, amide compounds, sulfo compounds, saturated hydrocarbon compounds, aromatic hydrocarbon compounds, halogenated hydrocarbon compounds, alcohol compounds, ketone compounds, ester compounds, and water can be used, if necessary. The above additives may be used alone or in combination of two or more. The above-mentioned additives can be used by mixing with compound (1) and / or compound (2), or the additives can be further mixed into a mixture of compound (1) and compound (2).

[0018] The additive is not particularly limited as long as it is a commonly used compound, and specific examples thereof include ether compounds such as tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 4-methyltetrahydropyran, cyclopentyl methyl ether, diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, methyl tert-butyl ether, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethylene glycol dibutyl ether, 1,2-dimethoxypropane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, and dipropylene glycol dimethyl ether; acetonitrile, propionitrile, butyl ether ... Nitrile compounds such as tyronitrile, isobutyronitrile, 2-methylbutyronitrile, cyclohexanecarbonitrile, benzonitrile, adiponitrile, m-fluorobenzonitrile, 2,3-difluorobenzonitrile, 2,3,4-trifluorobenzonitrile, 2,3,6-trifluorobenzonitrile, 2-fluoro-3-(trifluoromethyl)benzonitrile, 2-fluoro-4-(trifluoromethyl)benzonitrile, 2-fluoro-5-(trifluoromethyl)benzonitrile, 3-fluoro-5-(trifluoromethyl)benzonitrile, 2,3,4,5-tetrafluorobenzonitrile, fluoroacetonitrile, difluoroacetonitrile, 2-fluorobenzonitrile, 2,4,5-trifluorobenzonitrile, o-(trifluoromethyl)benzonitrile, and pentafluorobenzonitrile; N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methylpyrrolidone, tetramethylurea, and 1,Amide compounds such as 3-dimethyl-2-imidazolidinone, sulfo compounds such as dimethyl sulfoxide, dibutyl sulfoxide, ethyl methyl sulfone, ethyl isopropyl sulfone, sulfolane, and 3-methyl sulfolane, saturated hydrocarbon compounds such as n-pentane, n-hexane, isohexane, n-heptane, n-octane, isooctane, n-nonane, n-decane, cyclopentane, cyclohexane, cycloheptane, and cyclooctane, aromatic hydrocarbon compounds such as benzene, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, naphthalene, tetralin, and biphenyl, methylene chloride, chloroform, carbon tetrachloride, ethylene chloride, trichloroethane, tetrachloroethane, pentachloroethane, hexachloroethane, dichloroethylene, trichloroethylene, tetrachloroethylene, dichloropropane, trichloropropane, isopropyl chloride, butyl chloride, hexyl chloride, chlorobenzene, dichlorobenzene, and trichlorobenzene. , chlorotoluene, and chloronaphthalene, and other halogenated hydrocarbon compounds; methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, cyclohexanol, and other alcohol compounds; acetone, methylacetone, ethylmethylketone, methylpropylketone, methylbutylketone, methylisobutylketone, methylhexylketone, diethylketone, ethylbutylketone, dipropylketone, diisobutylketone, and cyclohexanone, and other ketone compounds; and ethylacetate, propylacetate, butylacetate, isobutylacetate, pentylacetate, hexylacetate, octylacetate, cyclohexylacetate, methylpropionate, ethylpropionate, butylpropionate, methylbenzoate, ethylbenzoate, propylbenzoate, butylbenzoate, and benzylbenzoate, and other ester compounds.

[0019] The above additives may be used with a reduced water content, if necessary. Additives with low water content can be purchased, or a method for reducing the water content of the additive can be used. The method for reducing the water content of the additive is not particularly limited as long as it is a commonly available method, and examples thereof include a method using a dehydrating agent and a distillation method. The dehydrating agent is not particularly limited as long as it is a commonly used dehydrating agent, and examples thereof include sodium hydride, magnesium sulfate, sodium sulfate, calcium sulfate, calcium chloride, zinc chloride, calcium oxide, magnesium oxide, diphosphorus pentoxide, activated alumina, silica gel, molecular sieve, etc. When a dehydrating agent is used, an additive containing a dehydrating agent may be used as long as it does not affect the reaction between compound (1) and compound (2), or an additive that does not contain a dehydrating agent after filtration or the like may be used.

[0020] <Ratio (β / α) of the amount of substance (β) of compound (2) to the amount of substance (α) of compound (1)> The ratio (β / α) of the amount of substance (β) of compound (2) to the amount of substance (α) of compound (1) is preferably 0.5 or more, more preferably 0.8 or more, since the yield of compound (3) tends to increase and the economic efficiency of the method for producing compound (3) tends to be excellent. Since the amount of unreacted compound (1) remaining can be suppressed, the ratio is further preferably 1 or more, and particularly preferably 1.5 or more.

[0021] The upper limit of the ratio (β / α) of the amount of substance (β) of compound (2) to the amount of substance (α) of compound (1) is not particularly limited, but since the amount of compound (2) used is reduced and the method for producing compound (3) tends to be more economical, it is preferably 100 or less, and from the same viewpoint, it is more preferable that β / α is 50 or less, even more preferable that β / α is 20 or less, and particularly preferable that β / α is 10 or less.

[0022] <Reaction of compound (1) with compound (2)> In the present embodiment, the reaction temperature refers to the temperature at which a container containing compound (1) or a container in which compound (1) and compound (2) are reacted is heated from the outside. The reaction temperature is not particularly limited as long as it is within a commonly used range, but is preferably 60 to 250°C. Depending on the type of compound (2), the reactivity with compound (1) tends to increase, so the temperature is more preferably 70°C or higher, even more preferably 80°C or higher, and particularly preferably 90°C or higher. Depending on the types of compound (1) and / or compound (3), deterioration due to heat tends to be suppressed, making the method for producing compound (3) more economical. Also, depending on the type of compound (1), volatilization tends to be suppressed, increasing the purity of compound (3). Therefore, the reaction temperature is more preferably 200° C. or less, even more preferably 170° C. or less, and particularly preferably 160° C. or less. The reaction temperature of compound (1) and compound (2) may be constant or may be changed during the reaction so long as it is within the above range. In the manufacturing method of this embodiment, compound (2) is added to compound (1) under heating. By heating compound (1) and / or compound (2) before mixing, the yield of compound (3) and compound (4) tends to be improved. Here, heating refers to heating compound (1) and / or compound (2) before mixing. Either compound (1) or compound (2) may be heated, or both may be heated. From the viewpoint of yield, it is preferable to add compound (2) to heated compound (1) at a temperature lower than the temperature of compound (1) after heating at an addition rate described below, and it is more preferable to heat only compound (1). The temperature of compound (1) after heating and the temperature of compound (2) after heating may be the same or different, but from the viewpoint of yield, they are preferably different, and it is more preferable that the temperature of compound (1) after heating is higher than the temperature at the time of adding compound (2). The temperature after the heating (preferably the temperature after the heating of compound (1)) is preferably 60° C. or higher, more preferably 70° C. or higher, even more preferably 80° C. or higher, and particularly preferably 90° C. or higher. From the viewpoint of improving the yield of compound (3) and compound (4) and further increasing the purity of the obtained compounds, the temperature is preferably 250° C. or lower, more preferably 200° C. or lower, even more preferably 170° C. or lower, and particularly preferably 160° C. or lower. From the viewpoint of yield, the difference between the temperature of compound (1) after heating and the temperature of compound (2) at the time of addition is preferably 0 to 200°C, more preferably 10 to 150°C, and even more preferably 20 to 130°C. In addition, the temperature after the heating (preferably the temperature after the heating of compound (1)) is preferably within the range of the reaction temperature ±30°C, more preferably within the range of the reaction temperature ±20°C, even more preferably within the range of the reaction temperature ±10°C, and particularly preferably within the range of the reaction temperature ±5°C, from the viewpoint of further improving the yields of compound (3) and compound (4).

[0023] The time from the start of adding compound (2) to compound (1) to the end of the total addition (hereinafter, sometimes referred to as "addition time") is not particularly limited as long as it is within a generally used range, but since side reactions due to a sudden reaction between compound (1) and compound (2) tend to be suppressed, it is preferably 1 minute or more, more preferably 3 minutes or more, and even more preferably 5 minutes or more. In addition, since an excessive addition time such that the reaction of compound (1) is completed and compound (1) no longer exists and the state in which compound (1) and compound (2) do not react continues for a long time tends to be a more economical production method, it is preferably 100 hours or less, more preferably 10 hours or less, even more preferably 5 hours or less, and particularly preferably 3 hours or less. The addition of compound (2) may be continuous or intermittent.

[0024] The rate of addition of compound (2) to compound (1) (meaning the value obtained by dividing the mass of compound (2) added by the addition time) is not particularly limited as long as it is within a range that is generally used, but since the reaction of compound (1) is completed and compound (1) is no longer present, and the state in which compound (1) and compound (2) do not react continues for a long time, the production method tends to be more economical, so the rate is preferably 0.01 g / min or more, more preferably 0.1 g / min or more, even more preferably 0.3 g / min or more, and particularly preferably 0.5 g / min or more. From the viewpoint of suppressing side reactions due to the sudden reaction of compound (1) and compound (2), the rate of addition of compound (2) to compound (1) is preferably 1000 g / min or less, more preferably 100 g / min or less, even more preferably 20 g / min or less, and particularly preferably 5 g / min or less. The rate of addition of compound (2) to compound (1) may be constant or may be changed midway within the above range. In the early stage of addition of compound (2), the reaction between compound (1) and compound (2) is likely to occur, but in the later stage of addition of compound (2), the reaction between compound (1) and compound (2) is unlikely to occur. Therefore, in some cases, it is preferable to slow down the rate of addition in the early stage of addition and increase the rate of addition toward the later stage of addition.

[0025] The ratio of the rate of addition of compound (2) to the mass of compound (1) (the mass of compound (2) added divided by the addition time and the mass of compound (1) used, which means the mass ratio of addition rate) is not particularly limited as long as it is within a commonly used range, but since it tends to be a more economical production method by not setting an excessive addition time such that the reaction of compound (1) is completed and compound (1) is no longer present, and the state in which compound (1) and compound (2) do not react continues for a long time, it is preferably 0.01 g / min / g or more, more preferably 0.05 g / min / g or more, even more preferably 0.08 g / min / g or more, and particularly preferably 0.1 g / min / g or more. From the viewpoint of suppressing side reactions due to the rapid reaction of compound (1) and compound (2), it is preferably 1000 g / min / g or less, more preferably 100 g / min / g or less, even more preferably 10 g / min / g or less, and particularly preferably 3 g / min / g or less. The ratio of the rate at which compound (2) is added to compound (1) relative to the mass of compound (1) may be constant or may be changed midway as long as it is within the above range.

[0026] After the addition of compound (2) is completed, the time for reacting the mixture of compound (1) and compound (2) is not particularly limited as long as it is within a commonly used range, but since the stability of the yield of compound (3) is further increased, it is preferably 0.1 hours or more, more preferably 0.3 hours or more, and even more preferably 0.5 hours or more. Since not making the reaction time excessive tends to result in a more economical production method, it is preferably 100 hours or less, and from the same viewpoint, it is more preferably 50 hours or less, even more preferably 10 hours or less, and particularly preferably 5 hours or less.

[0027] The pressure when reacting compound (1) with compound (2) is not particularly limited as long as it is within a range that is usually used, and may be any of pressurized, atmospheric, and reduced pressure, and may be changed during the reaction. Depending on the type of compound (1), it may volatilize at the reaction temperature. If compound (1) cannot be liquefied and reused, pressurizing to atmospheric pressure or higher is an effective method. When the generated compound (3) is separated during the reaction between compound (1) and compound (2), either atmospheric pressure or reduced pressure is preferable. From the viewpoint of promoting the separation of compound (3), reduced pressure is more preferable.

[0028] The atmosphere for the reaction of compound (1) and compound (2) is not particularly limited as long as it is a commonly used atmosphere, and typically, air, nitrogen, argon, and the like are used. Among these, nitrogen and argon atmospheres are preferred because they tend to produce compound (3) more safely. In addition, nitrogen atmosphere is more preferred because it tends to be a more economical production method. A circulating atmosphere may be used as a preferred method because it tends to promote separation of compound (3). The reaction atmosphere may be used alone or in combination of a plurality of reaction atmospheres.

[0029] The method used for reacting compound (1) and compound (2) is not particularly limited as long as it is a commonly used method, and examples thereof include a mixing tank type (horizontal type, vertical type), the number of stirring shafts (two shafts, three shafts, four shafts), the shape of the stirring blade (e.g., fan, propeller, cross, butterfly, dragonfly, turbine, disc turbine, disperse, paddle, inclined paddle, helical, double helical, ribbon, straight blade, 45° twist blade, 90° twist blade, etc.), and the installation of a baffle in the mixing tank. More specifically, examples of the apparatuses used in reacting compound (1) with compound (2) include a pressure kneader, Wonder kneader, kneading test device Mixlab, small-volume pressure kneader, MS-type small pressure kneader, twin-arm kneader, valve-equipped kneader, kneader-ruder, special pressure kneader, reduced-pressure pressure kneader, twin-screw taper extruder, twin-screw single-screw extruder, and feeder ruder manufactured by Nihon Spindle Mfg. Co., Ltd., and a KRC kneader, batch kneader, pressure kneader, extruder, CD dryer, SC processor, and CD kneader manufactured by Kurimoto Iron Works, Ltd. Dryer, Inoue Seisakusho Co., Ltd.'s BDM twin-shaft mixer, butterfly mixer, CDM concentric twin-shaft mixer, pony mixer, trimix, planetary mixer, PD mixer, kneader, flushing kneader, salt milling kneader, pressure kneader, and KX kneader, Pacific Machinery Co., Ltd.'s Pam Apex mixer, super double mixer, Nishimura Machinery Co., Ltd.'s vertical mixer, ribbon mixer, high-speed paddle mixer, and paddle mixer, Hosokawa Micron Co., Ltd.'s Byte mix, Nauta mixer, solid air, Micron Thermop Processor and Torus Disc, paddle dryer, single paddle dryer, Buno Cooler, multi-fin processor, extruder, and high-speed agitator / mixer granulator manufactured by Nara Machinery Co., Ltd., PV Mixer and SV Mixer manufactured by Kobelco Eco-Solutions Co., Ltd., Revo Cone and Flow Jet Granulator manufactured by Okawara Manufacturing Co., Ltd., twin-screw extruder manufactured by Japan Steel Works, Ltd., Hivis Mix, Hivis Disper Mix, and Combi Mix manufactured by Primix Corporation, ACM series manufactured by Aikosha Manufacturing Co., Ltd., Shinagawa Co., Ltd. Mixing and stirring machines, twin servo mixers, S-kneaders, spherical kneaders, spherical beveled-axis kneaders, and high-speed kneading granulators manufactured by Kogyosho Co., Ltd., intensive mixers and Evactherm manufactured by Nippon Eirich Co., Ltd., axial mixers and Hemisphere mixers manufactured by Sugiyama Heavy Industries Co., Ltd., vacuum stirrer dryers manufactured by Katsuragi Kogyo Co., Ltd., vacuum stirrer dryers manufactured by Yasujima Co., Ltd., mixers, semi-pressurized kneaders, kneader ruders, and vacuum extruders manufactured by MIG Co., Ltd., KID dryers, roturouba dryers, rotary dryers, and rotary kilns manufactured by Kurimoto Iron Works Co., Ltd.,Examples of such dryers include conical dryers manufactured by Kobelco Eco-Solutions Co., Ltd., electrically heated rotary kilns, gas heated rotary kilns, batch type rotary kilns, desktop rotary kilns, vacuum desktop rotary kilns, and special atmosphere + vacuum rotary kilns manufactured by Takasago Kogyo Co., Ltd., super rotary dryers and eco dryers manufactured by Okawara Seisakusho Co., Ltd., rotary kilns and double cone mixers manufactured by Sugiyama Heavy Industries Co., Ltd., double cone dryers manufactured by Katsuragi Kogyo Co., Ltd., and rotary kilns manufactured by Yasujima Co., Ltd., etc. The mixing device may be used alone or in combination of a plurality of types of mixing devices.

[0030] Examples of the method for adding compound (1) include a method of adding compound (1) by utilizing its own weight, a method of adding compound (1) by applying pressure, and a method of adding compound (1) by using a liquid-transfer pump (e.g., a smooth flow pump, a motor-driven metering pump, a solenoid-driven metering pump, an air-driven pump, a dynamic vacuum pump, a tube pump, a slurry pump, a magnet pump, an air-driven bellows pump, an electromagnetically-driven metering pump, a rotary volumetric pump, etc.). The method of adding compound (1) by using a liquid-transfer pump is preferred because it tends to have excellent controllability of the rate at which compound (1) is added. Examples of the method of adding compound (2) include a method of adding compound (2) by utilizing its own weight, a method of adding compound (2) by passing an air current (e.g., suction-type pneumatic transport, low-pressure pressure-feed pneumatic transport, high-pressure pressure-feed pneumatic transport, etc., and the pneumatic transport may be transport in a different atmosphere such as dry air transport, nitrogen transport, argon transport, etc.), and a method of adding compound (2) by using a powder feeder (e.g., screw feeder, vibration feeder, circle feeder, conveyor feeder, auger-type powder filling machine, weighing powder feeder, volumetric powder feeder, etc.). The method of using a powder feeder is preferred because it tends to have excellent controllability of the rate at which compound (2) is added.

[0031] Regarding the above-mentioned respective devices, adding means, containers, etc. (for example, a device for reacting compound (1) with compound (2), a container for adding compound (1) by utilizing its own weight, and a liquid delivery pump for adding compound (1)), and piping and the like connecting the respective devices, materials used in the places in contact with compound (1) and / or compound (2) are not particularly limited as long as they are generally used materials, and examples thereof include metals, metal alloys, resins, composite materials of metals and resins, ceramics, etc. More specific examples include titanium, nickel, zirconia, platinum, carbon steel, alloy steel, cast iron, stainless steel (SUS304, SUS304L, SUS430, SUS410, SUS316, SUS316L, SUS329J1, SUS329J4L, etc.), nickel-titanium alloys, nickel-chromium-molybdenum alloys (Inconel (registered trademark) 600, 625, 718, X750, etc., Hastelloy (registered trademark) C-22, C276, etc.), nickel-copper alloys (Monel (registered trademark) 400, K, S, H, Nickelvac (registered trademark) 400, Nikoros (registered trademark) 400, etc.), nickel-cobalt-chromium-molybdenum alloys, nickel-molybdenum alloys (Hastelloy (registered trademark) ALLOY B2, B, etc.), nickel-cobalt alloys, nickel-iron alloys, nickel-tungsten alloys, cobalt-chromium alloys, cobalt-chromium-molybdenum alloys (ELGILOY, PHYNOX (registered trademark), etc.), platinum-enriched stainless steel, fluorine-based resins (Teflon (registered trademark), copolymers of tetrafluoroethylene and perfluoroalkoxyethylene, perfluoroethylene propene copolymers, ethylene tetrafluoroethylene copolymers, polyvinylidene fluoride, polychlorotrifluoroethylene, ethylene chlorotrifluoroethylene copolymers, etc.), polyether ether ketone, polypropylene, polyphenylene ether, polyamide 6, polyamide 66, aromatic polyamide, polyphenylene sulfide, polysulfone, polyether sulfone, polyether imide, polyamide imide, etc. The above materials may be used alone or in combination of two or more.

[0032] The reaction of compound (1) with compound (2) produces compound (4) together with compound (3). Compounds (3) and (4) are known to be useful compounds as raw materials for fluoropolymer electrolytes, which are the main components of membranes for fuel cells, catalyst binder polymers for fuel cells, membranes for salt electrolysis, etc., and as raw materials that can be converted into various fluorine compounds. However, when using them, it is generally required to separate compound (3) and compound (4) and use them as each compound.

[0033] The method for separating compound (3) is not particularly limited as long as it is a commonly used method, and examples thereof include a method of distilling off and separating compound (3) while reacting compound (1) with compound (2), a method of distilling off and separating compound (3) after the reaction between compound (1) and compound (2) is completed, and a method of forming a solution containing compound (3) using a compound that can dissolve compound (3) but cannot dissolve compound (4), removing the compound used for dissolving, and separating compound (3), etc. Among these, the method of distilling off and separating compound (3) while reacting compound (1) with compound (2) is preferred because it does not require complicated operations and can separate compound (3). When compound (3) is distilled off while reacting compound (1) with compound (2), if the reaction temperature is a temperature at which compound (3) can be distilled off, the reaction may be carried out at normal pressure, or an inert gas (e.g., nitrogen) may be passed through compound (3) at normal pressure, or the reaction may be carried out at reduced pressure, or an inert gas (e.g., nitrogen) may be passed through compound (3) at reduced pressure. If the reaction temperature is insufficient to distill off compound (3), an inert gas (e.g., nitrogen) may be passed through compound (3) at normal pressure, or the reaction may be carried out at reduced pressure, or an inert gas (e.g., nitrogen) may be passed through compound (3) at reduced pressure.

[0034] Compounds that can dissolve the above-mentioned compound (3) but cannot dissolve the compound (4) are not particularly limited as long as they are compounds used in general boats, and include, for example, n-pentane, n-hexane, isohexane, n-heptane, n-octane, isooctane, n-nonane, n-decane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, benzene, toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, naphthalene, tetralin, biphenyl, methylene chloride, chloroform, carbon tetrachloride, ethylene chloride, trichloroethane, tetrachloroethane, pentachloroethane, hexachloroethane, dichloroethylene, trichloroethylene, tetrachloroethylene, dichloropropane, trichloropropane, Examples of suitable fluorine-based compounds include hydrocarbon compounds such as pantothenic acid, isopropyl chloride, butyl chloride, hexyl chloride, chlorobenzene, dichlorobenzene, trichlorobenzene, chlorotoluene, and chloronaphthalene; and fluorine-based compounds such as hydrofluoroethers, hydrofluorocarbons, hydrofluoroolefins, hydrochlorofluorocarbons, and hydrochlorofluoroolefins (more specifically, the Novec (registered trademark) series and Fluorinert (registered trademark) series manufactured by 3M, the Vertrel (registered trademark) series manufactured by Chemours, Solkan (registered trademark) manufactured by Solvay, the Asahiklin (registered trademark) series and Amorea (registered trademark) series manufactured by AGC Corporation, and Cerefin (registered trademark) manufactured by Central Glass Co., Ltd.). The compound capable of dissolving compound (3) but not compound (4) may be used alone or in combination of two or more kinds.

[0035] The purity of the separated compound (3) can be increased as necessary. The method for increasing the purity is not particularly limited as long as it is a commonly used method, but examples thereof include a method for increasing the purity by distillation, a method for reducing the content of the compound that decreases the purity contained in compound (3) by using a compound (hereinafter also referred to as an "extracted compound") that has a high solubility in the compound that decreases the purity and is separated from compound (3), and a combination of these methods.

[0036] When compound (3) is distilled, the distillation conditions are not particularly limited as long as they are generally used, and may be any of atmospheric distillation, pressurized distillation, and reduced pressure distillation. The distillation apparatus may be any of a plate tower, a packed tower, and a tower combining these. As the tray deck of the plate tower, any of a bubble cap, a sieve tray, a movable valve, and a fixed valve tray deck may be used. As the packing of the packed tower, any of a regular packing and an irregular packing may be used. When the amount of compound (3) to be distilled is small, an Oldershaw type distillation apparatus, a distillation apparatus equipped with a Vigreux column, a distillation apparatus equipped with a rotating band column, and a packed distillation apparatus may be used. As the packing, there is no particular limit as long as it is a commonly used packing, and examples thereof include Raschig rings, Lessing rings, Paul rings, Cross rings, Medalpack, Tollpack, Omnipack, Berl saddle, Intalox saddle, Dixon packing, McMahon packing, Helipack, Melapack, Gempack, Technopack, Flexipak, Sulzer packing, and Goodroll packing. The reflux ratio and the theoretical plate number can be in a generally used range, so long as they are reflux ratios and theoretical plate numbers that can achieve the desired purity of compound (3). The reflux ratio, which depends on the theoretical plate number, is preferably 100 or less, more preferably 50 or less, and even more preferably 25 or less, from the viewpoint of suppressing the energy required for distillation. Since the purity of compound (3) tends to improve, the reflux ratio is preferably 1 or more, more preferably 3 or more, and even more preferably 5 or more. As for the theoretical plate number, since the cost of the distillation apparatus can be suppressed and there is a tendency for it to be excellent in economy, it is preferably 300 or less, more preferably 200 or less, and even more preferably 100 or less. Since the purity of compound (3) tends to improve, the theoretical plate number is preferably 1 or more, more preferably 5 or more, and even more preferably 10 or more.

[0037] The separated compound (3) or the compound (3) distilled after separation can be mixed with the extracted compound to form a mixed solution. The extraction compound is not particularly limited as long as it is a commonly used compound, but examples thereof include water, an aqueous solution containing an inorganic salt, alcohol compounds such as methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, ethylene glycol, propylene glycol, and glycerol, amide compounds such as N,N-dimethylformamide, N,N-diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methylpyrrolidone, tetramethylurea, and 1,3-dimethyl-2-imidazolidinone, and sulfo compounds such as dimethylsulfoxide, dibutylsulfoxide, ethylmethylsulfone, ethylisopropylsulfone, sulfolane, and 3-methylsulfolane. Among these, water and an aqueous solution containing an inorganic salt are preferred because they tend to be less likely to be mixed into compound (3). The extract compound may be used alone or in combination of two or more kinds.

[0038] In this embodiment, the inorganic salt-containing aqueous solution may be an aqueous solution containing at least one inorganic salt compound selected from the group consisting of carbonates, sulfates, thiosulfates, acetates, phosphates, citrates, tartrates, and tetraborates.

[0039] The inorganic salt compound is not particularly limited as long as it is a commonly used compound, and specific examples thereof include carbonates such as lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, cesium hydrogen carbonate, ammonium hydrogen carbonate, lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, and ammonium carbonate; sulfates such as lithium hydrogen sulfate, sodium hydrogen sulfate, potassium hydrogen sulfate, rubidium hydrogen sulfate, cesium hydrogen sulfate, ammonium hydrogen sulfate, lithium sulfate, sodium sulfate, potassium sulfate, rubidium sulfate, cesium sulfate, and ammonium sulfate; thiosulfates such as lithium thiosulfate, sodium thiosulfate, potassium thiosulfate, rubidium thiosulfate, cesium thiosulfate, ammonium thiosulfate, and magnesium thiosulfate; acetates such as lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, and ammonium acetate; trilithium phosphate, trisodium phosphate, tripotassium phosphate, trirubidium phosphate, tricesium phosphate, triammonium phosphate, dilithium hydrogen phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, and dirubidium hydrogen phosphate; Phosphates such as disodium hydrogen phosphate, diammonium hydrogen phosphate, lithium dihydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, rubidium dihydrogen phosphate, cesium dihydrogen phosphate, and ammonium dihydrogen phosphate; trilithium citrate, trisodium citrate, tripotassium citrate, trirubidium citrate, tricesium citrate, triammonium citrate, dilithium hydrogen citrate, disodium hydrogen citrate, dipotassium hydrogen citrate, dirubidium hydrogen citrate, disodium hydrogen citrate, dicesium hydrogen citrate, diammonium hydrogen citrate, and lithium dihydrogen citrate. lithium, citrates such as sodium dihydrogen citrate, potassium dihydrogen citrate, rubidium dihydrogen citrate, cesium dihydrogen citrate, and ammonium dihydrogen citrate; tartrates such as lithium tartrate, sodium tartrate, potassium tartrate, rubidium tartrate, cesium tartrate, ammonium tartrate, lithium sodium tartrate, potassium sodium tartrate, potassium sodium tartrate, ammonium sodium tartrate, and potassium ammonium tartrate; lithium tetraborate, sodium tetraborate, potassium tetraborate, rubidium tetraborate, and cesium tetraborate;and tetraborates such as ammonium tetraborate.

[0040] Among these, sodium hydrogen carbonate, potassium hydrogen carbonate, cesium hydrogen carbonate, ammonium hydrogen carbonate, lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, ammonium carbonate, sodium hydrogen sulfate, potassium hydrogen sulfate, lithium sulfate, sodium sulfate, potassium sulfate, rubidium sulfate, cesium sulfate, ammonium sulfate, sodium thiosulfate, ammonium thiosulfate, magnesium thiosulfate, lithium acetate, sodium acetate, potassium acetate, rubidium acetate, cesium acetate, ammonium acetate, trilithium phosphate, trisodium phosphate, tripotassium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, diammonium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, ammonium dihydrogen phosphate, trilithium citrate, trisodium citrate, tripotassium citrate, triammonium citrate, disodium hydrogen citrate, diammonium hydrogen citrate, sodium tartrate, lithium tetraborate, sodium tetraborate, potassium tetraborate, and ammonium tetraborate are preferred because they tend to be easily available and economically advantageous. sodium, ammonium hydrogen carbonate, sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogen sulfate, potassium hydrogen sulfate, sodium sulfate, potassium sulfate, ammonium sulfate, sodium thiosulfate, ammonium thiosulfate, sodium acetate, potassium acetate, ammonium acetate, trisodium phosphate, tripotassium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, diammonium hydrogen phosphate, sodium dihydrogen phosphate, potassium dihydrogen phosphate, ammonium dihydrogen phosphate, trisodium citrate, tripotassium citrate, triammonium citrate, disodium hydrogen citrate, diammonium hydrogen citrate, sodium tartrate, sodium tetraborate, potassium tetraborate, and ammonium tetraborate are more preferred, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium hydrogen sulfate, potassium hydrogen sulfate, sodium sulfate, potassium thiosulfate, sodium acetate, potassium acetate, trisodium phosphate, tripotassium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, and potassium dihydrogen phosphate are even more preferred, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium carbonate, potassium carbonate, sodium hydrogen sulfate, potassium hydrogen sulfate, sodium sulfate, potassium thiosulfate, sodium acetate, potassium acetate, trisodium phosphate, tripotassium phosphate, disodium hydrogen phosphate, dipotassium hydrogen phosphate, sodium dihydrogen phosphate, and potassium dihydrogen phosphate are even more preferred, sodium hydrogen carbonate,Particularly preferred are sodium carbonate, sodium hydrogen sulfate, sodium sulfate, sodium thiosulfate, sodium acetate, trisodium phosphate, disodium hydrogen phosphate, and sodium dihydrogen phosphate.

[0041] The concentration of the inorganic salt-containing aqueous solution is not particularly limited, with the solubility of the inorganic salt compound as the upper limit. When the inorganic salt-containing aqueous solution is discarded after one use, the use of an excessive amount of the inorganic salt compound is suppressed, and the economical efficiency of producing the compound (3) tends to be excellent. Therefore, the concentration is preferably 0.5 times or less of the solubility of the inorganic salt compound, more preferably 0.2 times or less, even more preferably 0.1 times or less, and particularly preferably 0.05 times or less. When the inorganic salt-containing aqueous solution is used multiple times, the concentration is preferably 0.5 times or more of the solubility of the inorganic salt compound, more preferably 0.7 times or more, and even more preferably 0.9 times or more, since the property of reducing the content of the compound that reduces the purity contained in the compound (3) tends to be excellent.

[0042] <The ratio (ζ / ε) of the mass (ζ) of the extracted compound to the mass (ε) of compound (3) separated after the reaction of compound (1) with compound (2)> The ratio (ζ / ε) of the mass (ζ) of the extracted compound to the mass (ε) of compound (3) separated after the reaction of compound (1) with compound (2) is preferably 0.1 or more, more preferably 0.3 or more, and even more preferably 0.5 or more, since the content of compounds that reduce the purity of compound (3) tends to be further reduced.

[0043] The upper limit of the ratio (ζ / ε) of the mass (ζ) of the extracted compound to the mass (ε) of compound (3) separated after the reaction of compound (1) with compound (2), is not particularly limited. However, since the amount of compound (3) dissolved in the extracted compound tends to decrease, and the amount of compound (3) dispersed in the extracted compound tends to decrease, ζ / ε is preferably 100 or less, more preferably 20 or less, even more preferably 10 or less, and particularly preferably 5 or less.

[0044] After the reaction of compound (1) with compound (2), the separated compound (3) is stirred and mixed with the extracted compound, which tends to improve the rate at which the compound with a reduced purity is dissolved in the extracted compound. The stirring method is not particularly limited as long as it is a commonly used stirring method, and specific examples include stirring methods (stirring blade type, homogenizer, high pressure homogenizer, ultra-high pressure homogenizer, ultrasonic homogenizer, polytron homogenizer, etc.), stirring blade shapes (for example, fan, propeller, cross, butterfly, dragonfly, turbine, disk turbine, disperser, paddle, inclined paddle, etc.), installation of baffles in the reaction tank, and homogenizer shaft shapes (universal type, stirring type, multiple ultrasonic type, open type, closed type, etc.). In addition, devices equipped with the above stirring methods can be used. The above stirring methods and devices equipped with the stirring methods may be used alone or in combination of two or more.

[0045] The stirring / mixing time is not particularly limited as long as it is within a generally used range, but since the amount of compounds that reduce the purity of compound (3) that dissolve in the extracted compound tends to increase, it is preferably 0.01 hours or more, more preferably 0.1 hours or more, even more preferably 0.5 hours or more, and particularly preferably 1 hour or more. Since avoiding excessive stirring / mixing time tends to result in a more economical production method, it is preferably 100 hours or less, and from the same perspective, it is more preferably 50 hours or less, even more preferably 10 hours or less, and particularly preferably 5 hours or less.

[0046] Compound (3) and the extracted compound are stirred and mixed, and then the mixed solution is allowed to stand, whereby phase separation can occur into a phase containing compound (3) and a phase containing the extracted compound. The time for standing for phase separation is not particularly limited as long as it is within a range generally used, but since the amount of the phase containing compound (3) dispersed in the phase containing the extracted compound tends to decrease and the amount of compound (3) obtained tends to increase, it is preferably 0.01 hours or more, more preferably 0.1 hours or more, and even more preferably 0.5 hours or more. Since not leaving for an excessive time for standing tends to result in a more economical production method, it is preferably 100 hours or less, and from the same viewpoint, it is more preferably 50 hours or less, even more preferably 10 hours or less, and particularly preferably 5 hours or less.

[0047] The temperature at which the fluorinated vinylsulfonic acid fluoride (3) and the extract compound are stirred and mixed, and the temperature at which the mixture is left to stand and separated into phases are not particularly limited as long as they are generally used temperatures, but since there is a tendency for the amount of compounds that reduce the purity of compound (3) to dissolve in the extract compound to increase, and the amount of the phase containing compound (3) dispersed in the phase containing the extract compound to decrease, and the amount of compound (3) obtained to increase, the temperature is preferably -40°C or higher, and more preferably -20°C or higher. From the same viewpoint and from the tendency for there to be excellent economical efficiency in industrial temperature adjustment, the temperature is more preferably 0°C or higher, and particularly preferably 10°C or higher.

[0048] The upper limit of the temperature at which the fluorinated vinylsulfonic acid fluoride (3) and the extract compound are stirred and mixed, and the temperature at which they are allowed to stand and undergo phase separation, is not particularly limited, but since there is a tendency for dissolution of the compound (3) in the extract compound to be suppressed, the upper limit is preferably 120°C or lower, more preferably 100°C or lower, further preferably 80°C or lower, and particularly preferably 60°C or lower. The temperature at which the fluorine-containing vinylsulfonic acid fluoride (3) and the extraction compound are stirred and mixed, and the temperature at which they are left to stand for phase separation, may be constant or may be changed midway within the above range.

[0049] The pressure for stirring and mixing the fluorinated vinylsulfonic acid fluoride (3) and the extracted compound, and the pressure for allowing to stand and separating the phases are not particularly limited as long as they are within the ranges usually used, and the reaction is usually carried out under atmospheric pressure. However, since some types of the compound (3) and the extracted compound may volatilize, pressurization at atmospheric pressure or higher is an effective means for suppressing volatilization. When the volatilized compound is liquefied and reused, reduced pressure below atmospheric pressure may be used. The pressure under which the fluorinated vinylsulfonic acid fluoride (3) and the extraction compound are stirred and mixed, and the pressure under which they are left to stand for phase separation, may be constant or may be changed during the process so long as they are within the above range.

[0050] The atmosphere in which the fluorine-containing vinylsulfonic acid fluoride (3) and the extracted compound are stirred and mixed, and the atmosphere in which they are left to stand for phase separation are not particularly limited as long as they are commonly used, and usually, air, nitrogen, argon, etc. are used. Among these, nitrogen and argon atmospheres are preferred because they tend to produce compound (3) more safely. In addition, nitrogen atmosphere is more preferred because they tend to be a more economical production method. The atmosphere for stirring and mixing the fluorine-containing vinylsulfonic acid fluoride (3) and the extract compound, and the atmosphere for leaving them to effect phase separation may be one type alone or a combination of two or more types of atmospheres.

[0051] The fluorinated vinyl sulfonic acid fluoride (3) and the extracted compound are stirred and mixed, and then allowed to stand to cause phase separation. The phase containing the extracted compound thus obtained may be reused in preparing the above-mentioned mixed solution after the reaction of compound (1) with compound (2) in order to increase the purity of the separated compound (3). The fluorine-containing sulfonic acid fluoride (3) may be separated from the phase containing the phase-separated fluorine-containing sulfonic acid fluoride (3) by distillation.

[0052] Possible methods include using a smaller amount of compound (2) than compound (1) in the reaction between compound (1) and compound (2), leaving unreacted compound (1), separating the resulting compound (3), and then separating compound (1) from the resulting compound (4) to recover compound (1), or separating the resulting compound (3) and compound (1) from compound (4), and then separating compound (3) from compound (1) to recover compound (1). Reusing compound (1) after separation can reduce the waste of compound (1) and improve the economic efficiency of producing compound (3), but a recovery process is required. From the above viewpoints, and considering that between compound (1) and compound (2), compound (2) is more easily available and tends to be more economical for producing compound (3), it is considered that a method in which a larger amount of compound (2) is used than that of compound (1), the amount of unreacted compound (1) is reduced, a mixture containing compound (2), compound (3), and compound (4), compound (3) is obtained, and then compound (4) is separated from the mixture containing compound (2) and compound (4) tends to be more economical for producing compound (3).

[0053] The method for separating compound (4) from a mixture containing compound (2) and compound (4) (hereinafter referred to as "reaction residue") obtained after reacting compound (1) with compound (2) to produce compound (3) and separating compound (3) is not particularly limited as long as it is a commonly used method. For example, a method in which a compound having a high solubility in compound (4) and a low solubility in compound (2) (hereinafter referred to as "dissolved compound") is added to obtain a solution in which compound (4) is dissolved in the dissolved compound (hereinafter referred to as "fluorine-containing sulfonate solution"), compound (2) is removed by filtration, and then the compound having a high solubility in compound (4) is distilled off or compound (4) is crystallized to obtain compound (4) can be mentioned.

[0054] The dissolving compound is not particularly limited as long as it is a commonly used compound, but is preferably at least one compound selected from the group consisting of ether compounds, ketone compounds, ester compounds, carbonate compounds, and nitrile compounds.

[0055] Specific examples of the dissolving compound include ether compounds such as tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 4-methyltetrahydropyran, cyclopentyl methyl ether, diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, dihexyl ether, diheptyl ether, dioctyl ether, methyl tert-butyl ether, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethylene glycol dibutyl ether, 1,2-dimethoxypropane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, and dipropylene glycol dimethyl ether; acetone, methylacetone, ethyl methyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl tert-butyl ether, methyl tert-butyl ether, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethylene glycol dibutyl ether, 1,2-dimethoxypropane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol isopropyl methyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol butyl methyl ether, tetraethylene glycol dimethyl ether, and dipropylene glycol dimethyl ether; Ketone compounds such as ethylhexyl ketone, diethyl ketone, ethyl butyl ketone, dipropyl ketone, diisobutyl ketone, and cyclohexanone; ester compounds such as ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, hexyl acetate, octyl acetate, cyclohexyl acetate, methyl propionate, ethyl propionate, butyl propionate, methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, and benzyl benzoate; dimethyl carbonate, diethyl carbonate, dipropyl Carbonate, dibutyl carbonate, ethyl methyl carbonate, fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, trifluoromethyl methyl carbonate, bis(fluoromethyl)carbonate, bis(difluoromethyl)carbonate, bis(trifluoromethyl)carbonate, fluoromethyl difluoromethyl carbonate, 2,2,2-trifluoroethyl methyl carbonate, pentafluoroethyl methyl carbonate, ethyl trifluoromethyl carbonate, bis(2,2,2-trifluoroethyl) carbonate, ethylene carbonate, propylene carbonate, fluoroethylene carbonate, 4-(trifluoromethyl)-1,3-dioxolan-2-one, 4,4-difluoro-1,3-dioxolan-2-one, 4-fluoro-4-methyl-1,3-dioxolan-2-one, 4-(fluoromethyl)-1,3-dioxolan-2-one, 4,5-difluoro-1,3-dioxolan-2-one, 4-fluoro-5-methyl-1,3-dioxolan-2-one, 4,5-difluoro-4,5-dimethyl-1,3-dioxolan-2-one, vinylene carbonate, vinyl ethylene carbonate, methyl vinylene carbonate More preferred are carbonate compounds such as ethylvinylene carbonate and ethylvinylene carbonate, and acetonitrile, propionitrile, butyronitrile, isobutyronitrile, 2-methylbutyronitrile, cyclohexanecarbonitrile, benzonitrile, adiponitrile, fluoroacetonitrile, difluoroacetonitrile, 2-fluorobenzonitrile, 2,4,5-trifluorobenzonitrile, o-(trifluoromethyl)benzonitrile, and pentafluorobenzonitrile, and examples of such nitrile compounds include 2-fluorobenzonitrile, 2,4,5-trifluorobenzonitrile, o-(trifluoromethyl)benzonitrile, and pentafluorobenzonitrile.

[0056] Among the above ether compounds, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 4-methyltetrahydropyran, cyclopentyl methyl ether, diethyl ether, dipropyl ether, dibutyl ether, dipentyl ether, dihexyl ether, methyl tert-butyl ether, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethylene glycol dibutyl ether, 1,2-dimethoxypropane, and diethylene glycol dimethyl ether are preferred because they tend to be easily distilled off. Tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, diethyl ether, dipropyl ether, dibutyl ether, methyl tert-butyl ether, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, and 1,2-dimethoxypropane are more preferred because they tend to have high solubility of compound (4). More preferred are tetrahydrofuran, tetrahydropyran, methyl tert-butyl ether, 1,4-dioxane, and 1,2-dimethoxyethane because they are easily available or produced and tend to be economical.

[0057] Among the above ketone compounds, acetone, ethyl methyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, and cyclohexanone are preferred because the solubility of compound (4) is high, and acetone, ethyl methyl ketone, methyl propyl ketone, and methyl isobutyl ketone are more preferred, and acetone, ethyl methyl ketone, and methyl isobutyl ketone are even more preferred because they are easily available and tend to be economical.

[0058] Among the above ester compounds, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, hexyl acetate, cyclohexyl acetate, methyl propionate, ethyl propionate, and butyl propionate are preferred because they tend to be easily distilled off, and ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, methyl propionate, ethyl propionate, and butyl propionate are more preferred. Ethyl acetate, butyl acetate, and isobutyl acetate are even more preferred because they tend to be easily available and economically superior.

[0059] Among the above carbonate compounds, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, ethyl methyl carbonate, ethylene carbonate, propylene carbonate, vinylene carbonate, vinyl ethylene carbonate, methyl vinylene carbonate, and ethyl vinylene carbonate are preferred because they are easily available and tend to be economical, and dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, ethyl methyl carbonate, ethylene carbonate, and propylene carbonate are more preferred because the solubility of compound (4) tends to be high. Dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, and propylene carbonate are more preferred, and dimethyl carbonate and ethylene carbonate are particularly preferred.

[0060] Among the above nitrile compounds, acetonitrile, propionitrile, butyronitrile, isobutyronitrile, 2-methylbutyronitrile, cyclohexanecarbonitrile, benzonitrile, and adiponitrile are preferred because they are easily available and tend to be economically superior, and acetonitrile, propionitrile, butyronitrile, benzonitrile, and adiponitrile are more preferred. Acetonitrile, propionitrile, and adiponitrile are even more preferred because the solubility of compound (4) tends to be high.

[0061] <Ratio (δ / γ) of the mass of dissolved compound (δ) to the mass of reaction residue (γ)> The ratio (δ / γ) of the mass (δ) of the dissolved compound to the mass (γ) of the reaction residue is preferably 0.01 or more, more preferably 0.1 or more, even more preferably 0.5 or more, even more preferably 0.7 or more, and particularly preferably 1.0 or more, since the amount of compound (4) contained in the dissolved compound tends to increase. The upper limit of the ratio (δ / γ) of the mass (δ) of the dissolved compound to the mass (γ) of the reaction residue is not particularly limited, but is preferably 100 or less, more preferably 50 or less, even more preferably 25 or less, and particularly preferably 10 or less, since the use of an excessive amount of dissolved compound is suppressed and the production of compound (4) tends to be economical.

[0062] The method of stirring the reaction residue and the dissolved compound is not particularly limited as long as it is a commonly used stirring method, but specific examples include stirring methods (stirring blade type, homogenizer, high pressure homogenizer, ultra-high pressure homogenizer, ultrasonic homogenizer, polytron homogenizer, etc.), stirring blade shapes (for example, fan, propeller, cross, butterfly, dragonfly, turbine, disk turbine, disperser, paddle, inclined paddle, etc.), installation of baffles in the reaction tank, homogenizer shaft shapes (universal type, stirring type, multiple ultrasonic type, open type, closed type, etc.), etc. Also, devices equipped with the above stirring methods can be used. The above stirring methods and devices equipped with the stirring methods may be used alone or in combination of two or more.

[0063] The time for stirring the reaction residue and the dissolving compound is not particularly limited as long as it is within a range generally used, but since the amount of compound (4) dissolved in the dissolving compound tends to increase, it is preferably 0.01 hours or more, more preferably 0.1 hours or more, even more preferably 0.5 hours or more, and particularly preferably 1 hour or more. Since the production method tends to be more economical by avoiding excessive stirring and mixing time, it is preferably 100 hours or less, and from the same viewpoint, it is more preferably 50 hours or less, even more preferably 10 hours or less, and particularly preferably 5 hours or less.

[0064] The temperature at which the reaction residue and the dissolved compound are stirred is not particularly limited as long as it is a commonly used temperature, but since the rate at which compound (4) dissolves in the dissolved compound tends to improve, it is preferably -40°C or higher, and more preferably -20°C or higher. From the same viewpoint and from the tendency to be economically superior when adjusting the temperature industrially, it is more preferably 0°C or higher, and particularly preferably 10°C or higher. The upper limit of the temperature at which the reaction residue and the dissolved compound are stirred is not particularly limited, but since some types of dissolved compounds may volatilize, it is preferable that the temperature is 120°C or lower, more preferably 100°C or lower, more preferably 80°C or lower, and particularly preferably 60°C or lower, since the volatilization can be suppressed and the precipitation of compound (4) can be suppressed. The temperature at which the reaction residue and the dissolved compound are stirred may be constant or may be changed during the process as long as it is within the above range.

[0065] The pressure for stirring the reaction residue and the dissolved compound is not particularly limited as long as it is within the range that is usually used, and stirring is usually performed under atmospheric pressure. However, since some types of dissolved compounds may volatilize, it is effective to apply pressure at atmospheric pressure or higher to suppress volatilization. When the volatilized compounds are liquefied and reused, reduced pressure below atmospheric pressure may be used. The pressure under which the reaction residue and the dissolved compound are stirred may be constant or may be changed during the process as long as it is within the above range.

[0066] The atmosphere in which the reaction residue and the dissolved compound are stirred is not particularly limited as long as it is a commonly used atmosphere, and usually, air atmosphere, nitrogen atmosphere, argon atmosphere, etc. are used. Among these, nitrogen atmosphere and argon atmosphere are preferred because they tend to produce compound (4) more safely. In addition, nitrogen atmosphere is more preferred because it tends to be a more economical production method. The atmosphere for stirring the reaction residue and the dissolved compound may be one type alone or a combination of multiple types of atmospheres.

[0067] The method for separating compound (2) not dissolved in the fluorine-containing sulfonate solution is not particularly limited as long as it is a commonly used method, and examples thereof include a method of filtration separation, a method of precipitating compound (2) by centrifugation or leaving to stand, followed by solid-liquid separation and collecting the supernatant, etc. Among these, filtration separation is preferred because it tends to increase the recovery amount of compound (4) and is therefore more economical when producing compound (4).

[0068] The method of filtration and separation is not particularly limited as long as it is a commonly used method, and examples thereof include gravity filtration, centrifugal filtration, pressure filtration, reduced pressure filtration, squeeze filtration, magnetic filtration, electrostatic filtration, etc. These may be batch or continuous. The filtration device is not particularly limited as long as it is a device commonly used depending on the filtration method, and examples thereof include a horizontal filter plate type device, a multi-chamber horizontal filter plate type device, a ceramic membrane type device, a cylindrical multi-chamber type device, a cylindrical single-chamber type device, a horizontal traveling type device, a siphon type device, a basket type device, a separation plate type device, a decanter type device, a candle filter, and the like. The filtration device may be used alone or in combination of two or more types.

[0069] More specific examples of filtration devices include gravity type filtration devices such as strainers, sand filters, coke filter filters, sintered filter media filters, Nutsche filters, vibrating screens, rotary screens, belt strainers, candle plate discs, rotary drum filters, rotary disc filters, belt filters, table filters, pan filters, and internal feed type drum filters; centrifugal type filtration devices such as batch filters, quarter filters, scroll filters, pushers, vibrators, and centrifugal filters; pressurized Nutsche filters, filter presses, edge filters, compartment filters, paper roll filters, centrifugal discharge leaves, repulsive leaves, piston presses, plate presses, screw presses, Schneider filters, and pressurized pressurized filtration equipment such as scraper discharge filters, bag filters, candle filters, Druck filters, and sintered media filters; reduced pressure filtration equipment such as vacuum Nutsche filters, drum filters, Young filters, Dix filters, horizontal filters, horizontal belt filters, Nutsche filters, leaf filters, candle plate discs, rotary disc filters, rotary drum filters, belt filters, table filters, pan filters, internal feed type drum filters, and sintered media filters; compression filtration equipment such as belt presses, screw presses, tube presses, and Mars presses; magnetic filtration equipment such as ring-type magnetic separators and cylindrical magnetic separators; and electrostatic filtration equipment such as rotary electrostatic separators. The filtration device used for filtration and separation is equipped with a filtration layer that collects solids and allows liquid to pass through, and in this application, the filtration layer is referred to as a filter medium.

[0070] The apparatus that can be used in the method of settling compound (2), separating the solid and liquid, and collecting the supernatant is not particularly limited as long as it is a commonly used apparatus, and examples thereof include a decanter, a static screening machine, a kinetic screening machine, a table machine, a continuous settling tank, a batch settling tank, a tank with plates, a settling and flotation tank, an inclined classifier, a spiral classifier, a settling cone, a filter, a thickener, a scroll, a scroll disc, a gravitrol, a disc batch, a cylindrical bowl, a concentric circular bowl, a drum settling machine, a hydrocyclone, and a centrifugal separator.

[0071] In the filtration separation, a filter aid can be used as necessary. By using a filter aid, the removal efficiency of compound (2) can be improved (reducing the amount of residue and shortening the filtration time).

[0072] The filter aid is not particularly limited as long as it is a commonly used filter aid, but examples include diatomaceous earth (e.g., Radiolite manufactured by Showa Chemical Industry Co., Ltd., Celite manufactured by Imerys Co., Ltd., etc.), perlite (e.g., Topco manufactured by Showa Chemical Industry Co., Ltd., Rocahelp manufactured by Mitsui Mining and Smelting Co., Ltd., etc.), powdered cellulose (e.g., KC Flock manufactured by Nippon Paper Industries Co., Ltd., Rocaace Silky Aid manufactured by Musashino Chemical Research Institute Co., Ltd., etc.), etc. In addition, any of dried products, calcined products, and flux-calcined products can be used. Among these, diatomaceous earth and / or perlite are preferred, and diatomaceous earth is more preferred, because they have excellent removal efficiency of compound (2), are easily available, and tend to improve the economic efficiency of the process of purifying a sulfonic acid group-containing monomer. The filter aids may be used alone or in combination of two or more kinds.

[0073] The permeability (Darcy) of the filter aid is not particularly limited as long as it is within the range of commonly used permeability (Darcy), but is preferably 0.01 to 30. Since the residual amount of compound (2) tends to be small and the filtration time tends to be short, it is preferably 0.03 or more, and more preferably 0.05 or more. Since the filtration time of compound (2) tends to be short and the residual amount tends to be small, it is preferably 22 or less, more preferably 2 or less, and even more preferably 0.25 or less.

[0074] The amount of the filter aid used is not particularly limited as long as it is a commonly used amount, but the ratio (θ / η) of the mass (η) of the compound (2) to the mass (θ) of the filter aid is preferably 0.1 to 100. Since the residual amount of the compound (2) tends to be smaller and the filtration time tends to be shorter, θ / η is preferably 0.5 or more, more preferably 0.8 or more, and even more preferably 1 or more. Since the filtration time of the compound (2) tends to be shorter, θ / η is preferably 50 or less, and more preferably 30 or less. From the same viewpoint, and since the amount of the filter aid used is reduced and the economic efficiency when producing the compound (4) tends to be improved, it is more preferable that it is 20 or less, and particularly preferable that it is 10 or less.

[0075] The amount of filter aid used here is the total mass of the filter aid used in filtration and separation. For example, when the precoat method and the body feed method are used in combination, it is the total mass of the filter aid used in the two methods. In addition, when the filter aid layer formed by filtration and separation is partially removed and the remaining filter aid layer is reused, it is the total mass of the filter aid to be supplied and the remaining filter aid layer.

[0076] The method of using the filter aid is not particularly limited as long as it is a commonly used method, but examples include a pre-coat method in which a filter aid is attached to a filter medium to form a layer of the filter aid and then filtered, and a body feed method in which a filter aid is added to a liquid to be filtered and then filtered. These may be used alone or in combination of multiple types. The method of using the pre-coat method and the body feed method in combination is preferred because it tends to suppress clogging of the filter medium, tends to suppress clogging of the surface of the layer of the filter aid, and tends to extend the period during which it can be operated on an industrial scale.

[0077] The filter medium used for filtration and separation is not particularly limited as long as it is a commonly used filter medium, and examples thereof include filter cloth, metal filters, sintered metal filters, metal fiber / powder laminated types, etc. These may be used alone or in combination of two or more types. When using a filter cloth, it can be used in combination with a filter medium that supports the filter cloth, such as a metal filter, in order to improve the strength of the filter cloth.

[0078] The material of the filter cloth is not particularly limited as long as it is a commonly used material, and examples thereof include polypropylene, polyester, polyamide, vinylidene chloride, polyvinyl alcohol, polytetrafluoroethylene, modacrylic, cotton, etc. Polypropylene, polyester, and polyamide are preferred, and polypropylene and polyester are more preferred, because they are easily available and tend to improve the economic efficiency of the process of purifying the sulfonic acid group-containing monomer. When durability of the filter cloth is required due to the properties of the liquid to be filtered, vinylidene chloride and polytetrafluoroethylene are preferred, and polytetrafluoroethylene is more preferred.

[0079] The material of the metallic filter medium is not particularly limited as long as it is a commonly used material, and examples thereof include iron, carbon steel, stainless steel, alloys of nickel with molybdenum, chromium, iron, etc. (e.g., Hastelloy (trade name), Inconel (trade name), etc.), nickel, titanium, etc. are listed. Iron, carbon steel, and stainless steel are preferred because they are easily available and tend to improve the economic efficiency of the process of refining sulfonic acid group-containing monomers, and stainless steel is more preferred when durability of the metallic filter medium is required at the same time. When durability of the metallic filter medium is required due to the properties of the liquid to be filtered, alloys of nickel with molybdenum, chromium, iron, etc. and nickel are preferred, and when ease of availability is required at the same time, alloys of nickel with molybdenum, chromium, iron, etc. are more preferred.

[0080] The air permeability of the filter medium is not particularly limited as long as it is in a general range, but is preferably in the range of 0.01 to 200 cm 3 / cm 2 s is preferable. Since the filtration time of compound (2) tends to be short, it is preferable that the filtration rate is 0.05 cm 3 / cm 2 s or more is preferable, and 0.1 cm 3 / cm 2 s or more. The residual amount of compound (2) tends to be smaller, and when a filter aid is used, the amount of the filter aid that permeates tends to be smaller. 3 / cm 2 s or less is preferable, and 50 cm 3 / cm 2 s or less is more preferable, and 20 cm 3 / cm 2 It is even more preferable that the value is equal to or less than s.

[0081] The temperature during filtration and separation is not particularly limited as long as it is within a general temperature range, but is preferably 0 to 120°C. The temperature during filtration and separation is preferably 10°C or higher, more preferably 20°C or higher, because the viscosity of the filtrate tends to decrease, the filtration time tends to be shortened, and precipitation of compounds other than compound (2) may be suppressed. The temperature during filtration and separation is preferably 100°C or lower, more preferably 80°C or lower, because the amount of volatile components generated from the liquid to be filtered tends to decrease and the change in the state of the precipitate tends to be suppressed. The temperature is more preferably 70°C or lower, and particularly preferably 60°C or lower, because the amount of compound (2) dissolved in the dissolving compound tends to decrease and the residual amount of compound (2) tends to be smaller. The temperature during filtration and separation may be constant or may be varied.

[0082] The pressure on the side where the liquid being filtered through the filter media passes through (hereinafter referred to as the "downstream pressure") is lower than the pressure on the side where the liquid being filtered through the filter media is supplied (hereinafter referred to as the "upstream pressure"), so that compound (2) is collected on the side where the liquid being filtered through the filter media is supplied, and the filtrate can be recovered on the side where the liquid being filtered through the filter media passes through.

[0083] The upstream pressure and downstream pressure during filtration are not particularly limited as long as they are in the above-mentioned pressure state and are generally used pressures, and may be constant or may be changed.

[0084] In gravity filtration, the upstream pressure is normal pressure, and the liquid to be filtered is separated by the pressure generated by the weight of the liquid to be filtered.

[0085] In the case of pressure filtration, the upstream pressure is increased to perform filtration and separation. The upstream pressure in pressure filtration is not particularly limited as long as it is a commonly used pressure, but is preferably 0.01 to 2.0 MPaG. Since the filtration time of compound (2) tends to be shortened, it is more preferably 0.05 MPaG or more, and even more preferably 0.1 MPaG or more. Even if the pressure resistance of the filtration device is low, industrial filtration is possible, and since the filtration device tends to be generally easily available, it is more preferably 1.0 MPaG or less, even more preferably 0.6 MPaG or less, and particularly preferably 0.4 MPaG or less. The downstream pressure in pressure filtration is usually normal pressure, but can be reduced if the filtration time of compound (2) is desired to be shortened. The upstream and downstream pressures in pressure filtration may be constant or may be varied.

[0086] The downstream pressure in the reduced pressure filtration is not particularly limited as long as it is a commonly used pressure, but is below normal pressure. Since the filtration time of compound (2) tends to be shortened, it is preferably 0.08 MPaA or less, more preferably 0.06 MPaA or less, and even more preferably 0.04 MPaA or less. The lower limit of the downstream pressure in the reduced pressure filtration is not particularly limited and varies depending on the capacity of the pump for reducing the pressure and the airtightness of the filtration device, but since the size of the pump for reducing the pressure tends to be reduced and the structure of the filtration device tends to be prevented from becoming complicated in order to increase the airtightness of the filtration device, it is preferably 0.1 kPaA or more, more preferably 1 kPaA or more, and more preferably 2 kPaA or more. The downstream pressure in vacuum filtration may be constant or may vary.

[0087] The centrifugal force during centrifugal filtration is not particularly limited as long as it is within the range of commonly used centrifugal forces, but is preferably 100 to 10,000 G. Since the filtration time of compound (2) tends to be shortened, it is more preferably 500 G or more, and even more preferably 1,000 G or more. Since the structure of the centrifugal filtration device tends to be prevented from becoming complicated, it is more preferably 8,000 G or less, and even more preferably 7,000 G or less. The centrifugal force during centrifugal filtration may be constant or may be varied.

[0088] The amount of the liquid to be filtered is not particularly limited as long as it is within the range of a typical amount of the liquid to be filtered, but is preferably 10 to 10,000 kg / m 2 ·hr. Since the recovery amount of compound (4) per hour is increased and the economic efficiency of purifying compound (4) tends to improve, it is preferable that the recovery rate is 50 kg / m 2 hr or more is more preferable, and 80 kg / m 2 ·hr or more is even more preferable. When the supply amount of the liquid to be filtered is large, it is necessary to increase the amount of liquid passing through the filter medium. Therefore, it is necessary to reduce the resistance of the filter medium and the filter aid, and it is necessary to increase the air permeability of the filter medium and the air permeability of the filter aid. As a result, the amount of residual compound (2) increases. For the above reasons, there is a tendency to reduce the amount of residual compound (2), so it is preferable to use a filter medium with a filter capacity of 5000 kg / m 2 hr or less is more preferable, and 1000 kg / m 2 It is even more preferable that the time is 100 s or less. The supply of liquid to be filtered may be constant or may vary.

[0089] The atmosphere during filtration is not particularly limited as long as it is a commonly used atmosphere, and usually, air atmosphere, nitrogen atmosphere, argon atmosphere, etc. are used. Among these, nitrogen atmosphere and argon atmosphere are preferred because they tend to produce compound (4) more safely. In addition, nitrogen atmosphere is more preferred because it tends to be a more economical production method. The atmosphere for filtration may be one type alone or a combination of multiple types of atmospheres.

[0090] The mixture containing compound (2) recovered by filtering the fluorine-containing sulfonate solution (hereinafter referred to as "filtered residue") can be reused in the reaction for producing compound (3) from compound (1) and compound (2). The filtered residue may be used as it is, or the dissolved compound may be dried by vacuum drying or the like before being used. When the filtered residue is reused in the reaction for producing compound (3) from compound (1) and compound (2), unused compound (2) and the filtered residue or the dried filtered residue may be mixed and used in the reaction for producing compound (3) from compound (1) and compound (2).

[0091] The method for obtaining compound (4) by filtering the fluorine-containing sulfonate solution and separating the dissolved compounds from the recovered solution containing compound (4) (hereinafter referred to as "fluorine-containing sulfonate-containing filtrate") is not particularly limited as long as it is a commonly used method, and examples thereof include a method in which the dissolved compounds are distilled off under normal pressure or reduced pressure at room temperature or under heating conditions to separate compound (4). The temperature when heating to a temperature above room temperature is not particularly limited as long as it is within a commonly used range, but since there is a tendency for deterioration of compound (4) to be suppressed, it is preferably 250°C or less, more preferably 200°C or less, even more preferably 150°C or less, and particularly preferably 120°C or less. The temperature during the heating may be constant or may be changed during the heating process.

[0092] When the dissolved compounds are distilled off and compound (4) is separated, the lower limit of the pressure when reducing the pressure to a pressure lower than normal pressure is not particularly limited and varies depending on the capacity of a pump or the like for reducing the pressure and the airtightness of the device used. However, since there is a tendency for the size of the pump for reducing the pressure to be reduced and for the device used to have a high airtightness, the structure of the filtration device to be prevented from becoming complicated, the lower limit of the pressure is preferably 0.1 kPaA or more, more preferably 1 kPaA or more, and even more preferably 2 kPaA or more. The reduced pressure may be constant or may vary.

[0093] The atmosphere in which the dissolved compounds are distilled off and compound (4) is separated is not particularly limited as long as it is a commonly used atmosphere, and usually air, nitrogen, argon, and the like are used. Among these, nitrogen and argon atmospheres are preferred because they tend to produce compound (4) more safely. In addition, nitrogen atmosphere is more preferred because they tend to be a more economical production method. When the dissolved compounds are distilled off, circulation of the atmosphere tends to promote the distillation of the dissolved compounds, and therefore may be used as a preferred method. The atmosphere used for distilling off the dissolved compounds and separating the compound (4) may be one type alone or a combination of two or more types of atmospheres.

[0094] The apparatus used for separating the dissolved compounds from the fluorine-containing sulfonate-containing filtrate is not particularly limited as long as it is a commonly used apparatus, and examples thereof include a vertical mixer dryer, a horizontal mixer dryer, a spray dryer, a vibration dryer, a tray dryer, a double cone dryer, a belt dryer, a rotary evaporator, etc. More specific examples include a rebocone, an inner tube rotary, a sludge dryer, a super rotary dryer, an FV dryer, a horizontal fluidized bed dryer, a slit flow, a conduction flow, a slurry dryer, a rototiller, a custom dryer, an eco dryer, a groovy dryer, and an H-VCD dryer (manufactured by Okawara Manufacturing Co., Ltd.), a PV Mixer, an SV Mixer, conical dryer, and rotary filter dryer (manufactured by Kobelco Eco-Solutions Co., Ltd.), vacuum agitator dryer, vibrating fluidized bed device, vibrating dryer, drum dryer, shelf-type vacuum dryer, double cone dryer (manufactured by Chuo Kakoki Co., Ltd.), paddle dryer, Boono cooler, single paddle dryer, multi-fin processor, continuous fluidized bed dryer, batch-type fluidized dryer, Tornesch dryer, media fluidized dryer, tower dryer, and instantaneous airflow dryer (manufactured by Nara Machinery Co., Ltd.), CD dryer, M-CD dryer, KID dryer, steam tube dryer, airflow drying system, fluidized bed dryer, band dryer Examples of such dryers include dryers, rotovad dryers, rotary dryers, airflow dryers, SC processors, and rotary kilns (manufactured by Kurimoto Iron Works, Ltd.), band dryers, hot air box dryers, fluidized bed dryers, vibration fluidized bed dryers, airflow dryers, rotary crusher dryers, conical blender dryers, drum dryers, jacketed rotary dryers, vacuum tray dryers, vacuum vibration dryers, and agitator dryers (manufactured by Nippon Dryer Co., Ltd.), drum dryers, vacuum drum dryers, vacuum agitator dryers, and double cone dryers (manufactured by Katsuragi Kogyo Co., Ltd.), high evaporators (manufactured by Sakura Seisakusho Co., Ltd.), and vertical agitator dryers (manufactured by Salient Kogyo Co., Ltd.). These devices may be used alone or in combination of two or more types.

[0095] Compound (4) separated from compound (2) as described above can be reused as a raw material for compound (1) according to the method described in WO 2020 / 012913.

[0096] The dissolved compound (e.g., volatile components containing the dissolved compound) obtained when the dissolved compound is distilled off and compound (4) is separated can be reused in a step of mixing the reaction residue and the dissolved compound to prepare a fluorine-containing sulfonate solution. When reusing, the dissolved compound obtained when the dissolved compound is distilled off and compound (4) is separated may be mixed with unused dissolved compound and used.

[0097] By adding water to the fluorine-containing sulfonate-containing filtrate or adding the fluorine-containing sulfonate-containing filtrate to water and distilling off the dissolved compounds, an aqueous solution containing compound (4) (hereinafter referred to as "fluorine-containing sulfonate-containing aqueous solution") can be prepared without precipitating compound (4). When water is added to the fluorine-containing sulfonate-containing filtrate, the dissolved compounds may be distilled off once to prepare the fluorine-containing sulfonate-containing aqueous solution, or the addition and distillation of water may be repeated multiple times to prepare the fluorine-containing sulfonate-containing aqueous solution. Since the total mass of water used to reduce the dissolved compounds contained in the fluorine-containing sulfonate-containing aqueous solution tends to be reduced, a method in which water is added and distilled off multiple times is more preferred. When the fluorine-containing sulfonate-containing filtrate is added to water, the fluorine-containing sulfonate-containing filtrate is added to water once, and then the dissolved compounds are distilled off, and then water is further added and distilled off as necessary, since the total mass of water used tends to be reduced. This is a preferred method.

[0098] The ratio (κ / ι) of the mass (ι) of the fluorine-containing sulfonate-containing filtrate to the total mass (κ) of the water used when preparing the fluorine-containing sulfonic acid aqueous solution is not particularly limited as long as it is within a commonly used range, but since the amount of dissolved compounds contained in the fluorine-containing sulfonic acid aqueous solution tends to be reduced, it is preferably 0.1 or more, more preferably 0.5 or more, even more preferably 1.0 or more, and particularly preferably 1.2 or more. Depending on the concentration of compound (4) in the desired fluorine-containing sulfonic acid aqueous solution, the upper limit of κ / ι is not particularly limited, but since the total mass of the fluorine-containing sulfonate-containing filtrate and water tends to be small and the time required to distill off the dissolved compounds tends to be short, it is preferably 100 or less, more preferably 50 or less, even more preferably 25 or less, and particularly preferably 10 or less. When the concentration of compound (4) in the desired aqueous fluorinated sulfonic acid solution is low, it is more preferable to distill off the dissolved compounds at a small κ / ι ratio and then add water to adjust the concentration of compound (4) in the desired aqueous fluorinated sulfonic acid solution, since this tends to reduce the volume of the apparatus used for distillation and also tends to reduce the heat source used and the energy required to drive a vacuum pump when reducing the pressure.

[0099] The temperature at which water is added to the filtrate containing fluorine-containing sulfonate, the temperature at which the filtrate containing fluorine-containing sulfonate is added to water, and the temperature at which water is added after the distillation of the dissolved compounds are not particularly limited as long as they are generally used temperatures, but since there is a tendency to suppress the precipitation of compound (4), it is preferably -40 ° C or higher, and more preferably -20 ° C or higher. From the same viewpoint and from the tendency to be excellent in economics when adjusting the temperature industrially, it is more preferably 0 ° C or higher, and particularly preferably 10 ° C or higher. The upper limit of the temperature at which water is added to the filtrate containing fluorine-containing sulfonate, the temperature at which the filtrate containing fluorine-containing sulfonate is added to water, and the temperature at which water is added after the distillation of the dissolved compounds is not particularly limited, but since there is a tendency to suppress the volatilization and the precipitation of compound (4), it is preferably 120 ° C or lower, more preferably 100 ° C or lower, more preferably 80 ° C or lower, and particularly preferably 60 ° C or lower. The temperature at which water is added to the fluorine-containing sulfonate-containing filtrate, the temperature at which the fluorine-containing sulfonate-containing filtrate is added to water, and the temperature at which water is further added after the dissolved compounds have been distilled off may be constant or may be changed during the process.

[0100] The pressure of adding water to the filtrate containing fluorine-containing sulfonate, the pressure of adding the filtrate containing fluorine-containing sulfonate to water, and the pressure of adding water after distilling off the dissolved compounds are not particularly limited as long as they are within the ranges usually used, and are usually carried out under atmospheric pressure. However, since some types of dissolved compounds may volatilize, it is effective to pressurize at atmospheric pressure or higher in order to suppress volatilization. When volatilizing compounds are liquefied and reused, reduced pressure below atmospheric pressure may be used. The pressure when water is added to the fluorine-containing sulfonate-containing filtrate, the pressure when the fluorine-containing sulfonate-containing filtrate is added to water, and the pressure when water is further added after the dissolved compounds have been distilled off may be constant or may be changed midway as long as they are within the above-mentioned ranges.

[0101] The atmosphere for adding water to the fluorine-containing sulfonate-containing filtrate, the atmosphere for adding the fluorine-containing sulfonate-containing filtrate to water, and the atmosphere for adding water after distilling off the dissolved compounds are not particularly limited as long as they are commonly used atmospheres, and usually air atmosphere, nitrogen atmosphere, argon atmosphere, etc. are used. Among these, nitrogen atmosphere and argon atmosphere are preferred because they tend to produce compound (4) more safely. In addition, nitrogen atmosphere is more preferred because they tend to be a more economical production method. The atmosphere in which water is added to the fluorine-containing sulfonate-containing filtrate, the atmosphere in which the fluorine-containing sulfonate-containing filtrate is added to water, and the atmosphere in which water is further added after distillation of the dissolved compounds may be one kind alone or a combination of two or more kinds of atmospheres may be used.

[0102] The temperature when the dissolved compound is distilled off from the mixture of the fluorine-containing sulfonate-containing filtrate and water is not particularly limited as long as it is a commonly used temperature, but since there is a tendency for the efficiency of distilling off the dissolved compound (reduction in the amount of the dissolved compound remaining and shortening the distillation time) to be improved, it is preferably 0 ° C. or higher, more preferably 20 ° C. or higher, even more preferably 30 ° C. or higher, and particularly preferably 40 ° C. or higher. The upper limit of the temperature when the dissolved compound is distilled off from the mixture of the fluorine-containing sulfonate-containing filtrate and water is not particularly limited, but since there is a tendency for the deterioration of compound (4) to be suppressed, it is preferably 250 ° C. or lower, more preferably 200 ° C. or lower, even more preferably 150 ° C. or lower, and particularly preferably 120 ° C. or lower. The temperature at which the dissolved compounds are distilled off from the mixture of the fluorine-containing sulfonate-containing filtrate and water may be constant or may be changed during the process.

[0103] The pressure when the dissolved compound is distilled off from the mixture of the fluorine-containing sulfonate-containing filtrate and water is not particularly limited as long as it is within the range usually used, and may be pressurized, normal pressure, or reduced pressure, but is usually performed at normal pressure or reduced pressure. When the dissolved compound is distilled off at reduced pressure, the temperature during distillation can be lower than when distilled off at normal pressure, and depending on the type of compound (4), there is a tendency that the deterioration of compound (4) can be suppressed, so this is a preferred method. When the dissolved compound is distilled off at normal pressure, the energy required to drive the device used to achieve the desired pressure is not required, so this is a preferred method. The pressure at which the dissolved compounds are distilled off from the mixture of the fluorine-containing sulfonate-containing filtrate and water may be constant or may be changed during the process so long as it is within the above range.

[0104] The atmosphere in which the dissolved compound is distilled off from the mixture of the fluorine-containing sulfonate-containing filtrate and water is not particularly limited as long as it is a commonly used atmosphere, and usually, air atmosphere, nitrogen atmosphere, argon atmosphere, etc. are used. Among these, nitrogen atmosphere and argon atmosphere are preferred because they tend to produce compound (4) more safely. In addition, nitrogen atmosphere is more preferred because they tend to be a more economical production method. The atmosphere used when distilling off the dissolved compounds from the mixture of the fluorine-containing sulfonate-containing filtrate and water may be one type alone or a combination of two or more types of atmospheres.

[0105] The fluorine-containing sulfonic acid aqueous solution obtained as described above can be reused as a raw material for compound (1) according to the method described in WO 2020 / 012913.

[0106] The dissolved compound obtained by distilling off the dissolved compound from a mixture of a fluorine-containing sulfonate-containing filtrate and water can be reused in whole or in part when preparing a fluorine-containing sulfonate solution from the reaction residue and the dissolved compound.

[0107] When the dissolved compound obtained by distilling off the dissolved compound from the mixture of the fluorine-containing sulfonate-containing filtrate and water contains a large amount of water, and the amount of compound (2) contained in the reaction residue dissolved in the fluorine-containing sulfonate solution is large, the dissolved compound and water can be separated by distillation, or, depending on the type of the dissolved compound, the dissolved compound and water are separated into phases, so that the dissolved compound and water can be separated by distilling off the dissolved compound phase and separating the dissolved compound with an increased content, or by distilling off the water phase and separating the water with an increased content. The dissolved compound obtained by the above method can be reused in whole or in part when preparing a fluorine-containing sulfonate solution from the reaction residue and the dissolved compound. In addition, the water obtained by the above method can be reused in whole or in part when preparing an aqueous solution containing a fluorine-containing sulfonate.

[0108] As described above, the present invention can produce, in a high yield, fluorinated vinylsulfonic acid fluoride (3), which is useful as a raw material for fluorine-based polymer electrolytes that are main components of membranes for fuel cells, catalyst binder polymers for fuel cells, membranes for salt electrolysis, etc. Also, it can produce fluorinated vinylsulfonic acid salts (4), which can be converted into various fluorine compounds. Furthermore, it is possible to separate fluorinated vinylsulfonic acid fluoride (3) and fluorinated vinylsulfonic acid salts (4), and it is also possible to reuse the compounds used in the separation. EXAMPLES

[0109] The present invention is not limited to the following examples, so long as they do not depart from the gist of the present invention.

[0110] The analytical methods used in the examples and comparative examples are as follows.

[0111] <Nuclear magnetic resonance analysis (NMR): 19 Molecular structure analysis using F-NMR> Regarding the products obtained in the examples and comparative examples, 19Molecular structure analysis was carried out using F-NMR under the following measurement conditions. [Measurement conditions] Measurement equipment: JNM-ECZ400S nuclear magnetic resonance equipment (manufactured by JEOL Ltd.) Observation kernel: 19 F Solvent: deuterated chloroform Reference substance: tetramethylsilane (0.00 ppm) Observation frequency: 400MHz ( 1 H) Pulse width: 6.5μsec Wait time: 2 seconds Number of times: 16

[0112] <Nuclear magnetic resonance analysis (NMR): 1 Molecular structure analysis using H-NMR> Regarding the products obtained in the examples and comparative examples, 1 Molecular structure analysis was carried out using H-NMR under the following measurement conditions. [Measurement conditions] Measurement equipment: JNM-ECZ400S nuclear magnetic resonance equipment (manufactured by JEOL Ltd.) Observation kernel: 1 H Solvent: deuterated chloroform Reference substance: tetramethylsilane (0.00 ppm) Observation frequency: 400MHz ( 1 H) Pulse width: 7.3 μsec Wait time: 5 seconds Number of times: 8

[0113] <Gas Chromatography (GC)> The products obtained in the examples were subjected to molecular structure analysis using GC under the following measurement conditions. [Measurement conditions] Measuring device: GC-2010Plus Column: Capillary column RTX-200 (inner diameter 0.25 mm, length 60 m, film thickness 1 μm) manufactured by RESTEK, USA Carrier gas: Helium Carrier gas flow rate: 30mL / min Injection volume: 1μL Split ratio: 30 Vaporization chamber temperature: 200℃ Column temperature program: 40°C for 10 min, then increase temperature at 20°C / min, then hold at 280°C for 10 min Detection: FID, 200℃

[0114] The raw materials used in the examples and comparative examples are shown below.

[0115] [Production Example 1] (Fluorine-containing vinyl sulfonic anhydride (1) (compound (1)) According to JP 2019 / 156782 A, compound (7) represented by the following formula (7) was produced. CF2=CFOCF2CF2SO3Na (7) Using the obtained compound of formula (7) above, a compound (8) represented by the following formula (8) was produced according to WO 2020 / 012913. (CF2=CFOCF2CF2SO2)2O (8) The obtained compound (8) was distilled to obtain a purified mixed compound (8). The obtained mixed compound (8) had a purity of 98% by mass and contained 2% by mass of a compound (9) represented by the following formula (9). CF2=CFOCF2CF2SO3H (9)

[0116] (Alkali metal fluoride (2) (compound (2)) Potassium fluoride (Fujifilm Wako Pure Chemical Industries, special grade reagent) Rubidium fluoride (Aldrich, 99.8% purity) Cesium fluoride (Fujifilm Wako Pure Chemical Industries, special grade reagent)

[0117] (others) Ethanol (Fujifilm Wako Pure Chemical Industries, special grade reagent) Hexafluorobenzene (Tokyo Chemical Industry Co., Ltd.) Benzotrifluoride (Tokyo Chemical Industry Co., Ltd.) Purified water (Fujifilm Wako Pure Chemical Industries, Ltd.) 2,2,2-Trifluoroethanol (Tokyo Chemical Industry Co., Ltd.) Acetonitrile (Fujifilm Wako Pure Chemical Industries, special grade reagent) Butyl acetate (Fujifilm Wako Pure Chemical Industries, special grade reagent) 4-Methyl-2-pentanone (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) Dimethyl carbonate (Fujifilm Wako Pure Chemical Industries, special grade reagent) 1,2-Dimethoxyethane (Fujifilm Wako Pure Chemical Industries, Ltd., Wako special grade) Sodium bicarbonate aqueous solution: Prepared by mixing 18.0 g of sodium bicarbonate (special grade reagent, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 182.0 g of purified water.

[0118] [Example 1] In a space with a nitrogen atmosphere, 349.8 g of the mixed compound (8) produced in Production Example 1 (comprising 342.8 g (0.637 mol) of compound (8) and 7.00 g (0.025 mol) of compound (9)) was placed in a flask, and a half-moon-shaped stirring rod and a Liebig condenser with a receiver were attached. Furthermore, a concentration flask containing potassium fluoride dried at 150°C for 5 hours under vacuum was attached to the flask via an airless feed cock (manufactured by Asahi Seisakusho Co., Ltd.). The flask was removed from the space with a nitrogen atmosphere, and a three-one motor (manufactured by Shinto Scientific Co., Ltd., BLW300) was attached, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. Teflon (registered trademark) piping was installed so that the pressure between the concentration flask and the flask was equalized. The flask was placed in an oil bath (Tokyo Rikakikai Co., Ltd., OHB-3100S) set at 110°C, the pressure was reduced to 70 kPaA, and the mixture was stirred at 120 rpm for 10 minutes. By operating the airless feed cock, potassium fluoride was gradually added to the flask. It took 44 minutes to finish adding potassium fluoride to the flask. After the reaction was completed, the mass of the concentrated flask with the airless feed cock was measured before and after the addition, and it was found that 58.1 g (1.00 mol) of potassium fluoride had been added. When potassium fluoride was added, the liquid gradually began to be distilled out, and when the rate of the liquid distilled into the receiver reached 2 drops / min, the pressure was gradually reduced, finally reaching 2 kPaA. When the liquid did not distill into the receiver for more than 2 minutes, the reaction was judged to be complete, the flask was removed from the oil bath, a nitrogen atmosphere was created, and the rotation of the three-one motor was stopped. The refrigerant flowing through the Liebig condenser was stopped, the receiver was returned to room temperature, and the mass of the fraction in the receiver was measured, which was 176.5 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed together, 19Analysis was performed by F-NMR. As a result of the analysis, it was found that fluorine-containing vinyl sulfonic acid fluoride (10) represented by the following general formula (10) was produced (production amount: 170.5 g, product mass: 0.609 mol, production rate: 95.6%). In the analysis, the production amount of fluorine-containing vinyl sulfonic acid fluoride (10) was calculated from the mass of benzotrifluoride, the integral value of CF3 of benzotrifluoride, and the integral value of CF2 of fluorine-containing vinyl sulfonic acid fluoride (10). The production rate of fluorine-containing vinyl sulfonic acid fluoride (10) was calculated by the following formula (1). Production rate (%) of fluorine-containing vinyl sulfonic acid fluoride (10) = amount of fluorine-containing vinyl sulfonic acid fluoride (10) / amount of compound (8) × 100 (1) For example, the production rate (%) of the fluorine-containing vinylsulfonic acid fluoride (10) in this example is 0.609 (mol) / 0.637 (mol)×100=95.6. In this example, β / α was 1.6. CF2=CFOCF2CF2SO2F (10) 19 F-NMR: δ(ppm)42.43(1F), -86.34(2F), -114.21(2F), -116.58(1F), -123.87(1F), -138.96(1F) The residue remaining in the flask was collected and its mass was measured, which was 222.1 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and 19 The reaction mixture was analyzed by F-NMR. As a result of the analysis, it was confirmed that the fluorine-containing vinyl sulfonate (11) represented by the following general formula (11) was produced (amount produced: 202.3 g, mass of product: 0.640 mol). In the analysis, the amount of fluorine-containing vinyl sulfonate (11) produced was calculated from the mass of 2,2,2-trifluoroethanol, the integral value of CF3 of 2,2,2-trifluoroethanol, and the integral value of CF2 of fluorine-containing vinyl sulfonate (11). CF2=CFOCF2CF2SO3K (11) 19F-NMR: δ(ppm) -84.83(2F), -113.83(1F), -118.30(2F), -122.05(1F), -135.70(1F) In this example, the rate at which compound (2) was added to the flask (hereinafter referred to as "addition rate") was 1.3 g / min. The addition rate was calculated from the mass of compound (2) (58.1 g) and the time required to add compound (2) (44 min) as follows: 58.1 (g) / 44 (min) = 1.3 (g / min). The same calculation was performed in the following examples. In this example, the ratio of the rate at which compound (2) was added to the flask to the mass of compound (8) produced in Production Example 1 (hereinafter referred to as "mass ratio addition rate") was 0.23 g / min / g. The mass ratio addition rate was calculated as 58.1 (g) / 44 (min) / 349.8 (g) = 0.23 (g / min / g) from the mass of compound (2) (58.1 g), the time required for adding compound (2) (44 min), and the mass of compound (8) produced in Production Example 1 (349.8 g). Similar calculations were performed in the following examples.

[0119] [Example 2] In a space with a nitrogen atmosphere, 250.1 g of the mixed compound (8) produced in Production Example 1 (245.1 g (0.455 mol) of compound (8) and 5.00 g (0.018 mol) of compound (9)) was placed in a flask, and a half-moon-shaped stirring rod and a Liebig condenser with a receiver were attached. Furthermore, a concentration flask containing potassium fluoride dried at 150°C for 5 hours under vacuum was attached to the flask via an airless feed cock (manufactured by Asahi Seisakusho Co., Ltd.). The flask was removed from the space with a nitrogen atmosphere, and a three-one motor (manufactured by Shinto Scientific Co., Ltd., BLW300) was attached, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. Teflon (registered trademark) piping was installed so that the pressure between the concentration flask and the flask was equalized. The flask was placed in an oil bath (Tokyo Rikakikai Co., Ltd., OHB-3100S) set at 130°C, the pressure was reduced to 80 kPaA, and the mixture was stirred at 120 rpm for 10 minutes. By operating the airless feed cock, potassium fluoride was gradually added to the flask. It took 23 minutes to finish adding potassium fluoride to the flask. After the reaction was completed, the mass of the concentrated flask with the airless feed cock was measured before and after the addition, and it was found that 45.5 g (0.784 mol) of potassium fluoride had been added. When potassium fluoride was added, the liquid gradually began to be distilled out, and when the rate of the liquid distilled into the receiver reached 2 drops / min, the pressure was gradually reduced, finally reaching 2 kPaA. When the liquid did not distill into the receiver for more than 2 minutes, the reaction was judged to be complete, the flask was removed from the oil bath, a nitrogen atmosphere was created, and the rotation of the three-one motor was stopped. The refrigerant flowing through the Liebig condenser was stopped, the receiver was returned to room temperature, and the mass of the fraction in the receiver was measured, which was 127.4 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed together, 19 F-NMR analysis revealed that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 116.4 g, product mass: 0.416 mol, production rate: 91.3%). In this example, β / α was 1.7. The residue remaining in the flask was collected and its mass was measured, which was 162.5 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and 19 F-NMR analysis confirmed that the fluorine-containing vinyl sulfonate (11) represented by the following general formula (11) was produced (amount produced: 143.9 g, product mass: 0.455 mol). In this example, the addition rate was 2.0 g / min, and the mass specific addition rate was 0.48 g / min / g.

[0120] [Example 3] In a space with a nitrogen atmosphere, 100.2 g of the mixed compound (8) produced in Production Example 1 (comprising 98.2 g (0.182 mol) of compound (8) and 2.00 g (0.007 mol) of compound (9)) was placed in a flask, and a crescent-shaped stirring rod and a Liebig condenser with a receiver were attached. Furthermore, a concentration flask containing potassium fluoride dried at 150°C for 5 hours under vacuum was attached to the flask via an airless feed cock (manufactured by Asahi Seisakusho Co., Ltd.). The flask was removed from the space with a nitrogen atmosphere, and a three-one motor (manufactured by Shinto Scientific Co., Ltd., BLW300) was attached, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. Teflon (registered trademark) piping was installed so that the pressure between the concentration flask and the flask was equalized. The flask was placed in an oil bath (Tokyo Rikakikai Co., Ltd., OHB-3100S) set at 150°C, the pressure was reduced to 90 kPaA, and the mixture was stirred at 120 rpm for 10 minutes. The airless feed cock was operated to gradually add potassium fluoride to the flask. It took 5 minutes to finish adding potassium fluoride to the flask. After the reaction was completed, the mass of the concentrated flask with the airless feed cock was measured before and after the addition, and it was found that 19.8 g (0.341 mol) of potassium fluoride had been added. When potassium fluoride was added, the liquid gradually began to be distilled out, and when the rate of the liquid distilled into the receiver reached 2 drops / min, the pressure was gradually reduced, finally reaching 2 kPaA. When the liquid did not distill into the receiver for more than 2 minutes, the reaction was judged to be complete, the flask was removed from the oil bath, a nitrogen atmosphere was created, and the rotation of the three-one motor was stopped. The refrigerant flowing through the Liebig condenser was stopped, the receiver was returned to room temperature, and the mass of the fraction in the receiver was measured, which was 51.5 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed together, 19 F-NMR analysis revealed that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 44.3 g, product mass: 0.158 mol, production rate: 86.6%). In this example, β / α was 1.9. The residue remaining in the flask was collected and its mass was measured, which was 66.8 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and 19 F-NMR analysis confirmed that the fluorine-containing vinyl sulfonate (11) represented by the following general formula (11) was produced (amount produced: 57.6 g, product mass: 0.182 mol). In this example, the addition rate was 4.0 g / min, and the mass specific addition rate was 2.4 g / min / g.

[0121] [Example 4] In a space with a nitrogen atmosphere, 200.1 g of the mixed compound (8) produced in Production Example 1 (196.1 g (0.364 mol) of compound (8) and 4.00 g (0.014 mol) of compound (9)) was placed in a flask, and a half-moon-shaped stirring rod and a Liebig condenser with a receiver were attached. Furthermore, a concentration flask containing potassium fluoride dried at 150°C for 5 hours under vacuum was attached to the flask via an airless feed cock (manufactured by Asahi Seisakusho Co., Ltd.). The flask was removed from the space with a nitrogen atmosphere, and a three-one motor (manufactured by Shinto Scientific Co., Ltd., BLW300) was attached, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. Teflon (registered trademark) piping was installed so that the pressure between the concentration flask and the flask was equalized. The flask was placed in an oil bath (Tokyo Rikakikai Co., Ltd., OHB-3100S) set at 90°C, the pressure was reduced to 60 kPaA, and the mixture was stirred at 120 rpm for 10 minutes. Potassium fluoride was gradually added to the flask by operating the airless feed cock. It took 50 minutes to finish adding potassium fluoride to the flask. After the reaction was completed, the mass of the concentrated flask with the airless feed cock was measured before and after the addition, and it was found that 33.0 g (0.568 mol) of potassium fluoride had been added. When potassium fluoride was added, the liquid gradually began to be distilled out, and when the rate of the liquid distilled into the receiver reached 2 drops / min, the pressure was gradually reduced, finally reaching 2 kPaA. When the liquid did not distill into the receiver for more than 2 minutes, the reaction was judged to be complete, the flask was removed from the oil bath, a nitrogen atmosphere was created, and the rotation of the three-one motor was stopped. The refrigerant flowing through the Liebig condenser was stopped, the receiver was returned to room temperature, and the mass of the fraction in the receiver was measured, which was 102.0 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed together, 19 F-NMR analysis revealed that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 97.3 g, product mass: 0.348 mol, production rate: 95.4%). In this example, β / α was 1.6. The residue remaining in the flask was collected and its mass was measured, which was 126.6 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and 19 F-NMR analysis confirmed that the fluorine-containing vinyl sulfonate (11) represented by the following general formula (11) was produced (amount produced: 115.4 g, product mass: 0.365 mol). In this example, the addition rate was 0.66 g / min, and the mass specific addition rate was 0.20 g / min / g.

[0122] [Example 5] In a space with a nitrogen atmosphere, 349.9 g of the mixed compound (8) produced in Production Example 1 (comprising 342.9 g (0.637 mol) of compound (8) and 7.00 g (0.025 mol) of compound (9)) was placed in a flask, and a half-moon-shaped stirring rod and a Liebig condenser with a receiver were attached. Furthermore, a concentration flask containing potassium fluoride dried at 150°C for 5 hours under vacuum was attached to the flask via an airless feed cock (manufactured by Asahi Seisakusho Co., Ltd.). The flask was removed from the space with a nitrogen atmosphere, and a three-one motor (manufactured by Shinto Scientific Co., Ltd., BLW300) was attached, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. Teflon (registered trademark) piping was installed so that the pressure between the concentration flask and the flask was equalized. The flask was placed in an oil bath (Tokyo Rikakikai Co., Ltd., OHB-3100S) set at 110°C, the pressure was reduced to 70 kPaA, and the mixture was stirred at 120 rpm for 10 minutes. Potassium fluoride was gradually added to the flask by operating the airless feed cock. It took 32 minutes to finish adding potassium fluoride to the flask. After the reaction was completed, the mass of the concentrated flask with the airless feed cock was measured before and after the addition, and it was found that 42.2 g (0.727 mol) of potassium fluoride had been added. When potassium fluoride was added, the liquid gradually began to be distilled out, and when the rate of the liquid distilled into the receiver reached 2 drops / min, the pressure was gradually reduced, finally reaching 2 kPaA. When the liquid did not distill into the receiver for more than 2 minutes, the reaction was judged to be complete, the flask was removed from the oil bath, a nitrogen atmosphere was created, and the rotation of the three-one motor was stopped. The refrigerant flowing through the Liebig condenser was stopped, the receiver was returned to room temperature, and the mass of the fraction in the receiver was measured, which was 183.3 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed together, 19 F-NMR analysis revealed that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 161.2 g, product mass: 0.575 mol, production rate: 90.3%). In this example, β / α was 1.1. The residue remaining in the flask was collected and its mass was measured, which was 202.9 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and 19 F-NMR analysis confirmed that the fluorine-containing vinyl sulfonate (11) represented by the following general formula (11) was produced (amount produced: 197.3 g, product mass: 0.624 mol). In this example, the addition rate was 1.3 g / min, and the mass specific addition rate was 0.23 g / min / g.

[0123] [Example 6] In a space with a nitrogen atmosphere, 100.1 g of the mixed compound (8) produced in Production Example 1 (comprising 98.1 g (0.182 mol) of compound (8) and 2.00 g (0.007 mol) of compound (9)) was placed in a flask, and a crescent-shaped stirring rod and a Liebig condenser with a receiver were attached. Furthermore, a concentration flask containing potassium fluoride dried at 150°C for 5 hours under vacuum was attached to the flask via an airless feed cock (manufactured by Asahi Seisakusho Co., Ltd.). The flask was removed from the space with a nitrogen atmosphere, and a three-one motor (manufactured by Shinto Scientific Co., Ltd., BLW300) was attached, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. Teflon (registered trademark) piping was installed so that the pressure between the concentration flask and the flask was equalized. The flask was placed in an oil bath (Tokyo Rikakikai Co., Ltd., OHB-3100S) set at 110°C, the pressure was reduced to 70 kPaA, and the mixture was stirred at 120 rpm for 10 minutes. By operating the airless feed cock, potassium fluoride was gradually added to the flask. It took 75 minutes to finish adding potassium fluoride to the flask. After the reaction was completed, the mass of the concentrated flask with the airless feed cock was measured before and after the addition, and it was found that 99.0 g (1.70 mol) of potassium fluoride had been added. When potassium fluoride was added, the liquid gradually began to be distilled out, and when the rate of the liquid distilled into the receiver reached 2 drops / min, the pressure was gradually reduced, finally reaching 2 kPaA. When the liquid did not distill into the receiver for more than 2 minutes, the reaction was judged to be complete, the flask was removed from the oil bath, a nitrogen atmosphere was created, and the rotation of the three-one motor was stopped. The refrigerant flowing through the Liebig condenser was stopped, the receiver was returned to room temperature, and the mass of the fraction in the receiver was measured, which was 50.3 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed together, 19 F-NMR analysis revealed that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 48.8 g, product mass: 0.174 mol, production rate: 95.6%). In this example, β / α was 9.3. The residue remaining in the flask was collected and its mass was measured, which was 145.6 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and 19 F-NMR analysis confirmed that the fluorine-containing vinyl sulfonate (11) represented by the following general formula (11) was produced (amount produced: 58.5 g, product mass: 0.185 mol). In this example, the addition rate was 1.3 g / min, and the mass specific addition rate was 0.79 g / min / g.

[0124] [Example 7] In a space with a nitrogen atmosphere, 100.0 g of the mixed compound (8) produced in Production Example 1 (comprising 98.0 g (0.182 mol) of compound (8) and 2.00 g (0.007 mol) of compound (9)) was placed in a flask, and a crescent-shaped stirring rod and a Liebig condenser with a receiver were attached. Furthermore, a concentration flask containing rubidium fluoride dried at 150°C for 5 hours under vacuum was attached to the flask via an airless feed cock (manufactured by Asahi Seisakusho Co., Ltd.). The flask was removed from the space with a nitrogen atmosphere, and a three-one motor (manufactured by Shinto Scientific Co., Ltd., BLW300) was attached. A refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. Teflon (registered trademark) piping was installed so that the pressure between the concentration flask and the flask was equalized. The flask was placed in an oil bath (Tokyo Rikakikai Co., Ltd., OHB-3100S) set at 80°C, the pressure was reduced to 70 kPaA, and the mixture was stirred at 120 rpm for 10 minutes. Rubidium fluoride was gradually added to the flask by operating the airless feed cock. It took 46 minutes to finish adding rubidium fluoride to the flask. After the reaction was completed, the mass of the concentration flask with the airless feed cock was measured before and after the addition, and it was found that 33.1 g (0.317 mol) of rubidium fluoride had been added. When rubidium fluoride was added, the liquid gradually began to be distilled out, and when the rate of the liquid distilled into the receiver reached 2 drops / min, the pressure was gradually reduced, finally reaching 2 kPaA. When the liquid did not distill into the receiver for more than 2 minutes, the reaction was judged to be complete, the flask was removed from the oil bath, a nitrogen atmosphere was created, and the rotation of the three-one motor was stopped. The refrigerant flowing through the Liebig condenser was stopped, the receiver was returned to room temperature, and the mass of the fraction in the receiver was measured, which was 49.0 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed together, 19 F-NMR analysis revealed that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 48.3 g, product mass: 0.173 mol, production rate: 94.8%). In this example, β / α was 1.7. The residue remaining in the flask was collected and its mass was measured, which was 79.9 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and 19 The reaction mixture was analyzed by F-NMR. As a result of the analysis, it was confirmed that fluorine-containing vinyl sulfonate (4) (a compound represented by formula (4) in which m is 0, n is 2, and M is Rb) was produced (amount produced: 66.7 g, product mass: 0.184 mol). In this example, the addition rate was 0.72 g / min, and the mass specific addition rate was 0.43 g / min / g.

[0125] [Example 8] In a space with a nitrogen atmosphere, 100.2 g of the mixed compound (8) produced in Production Example 1 (comprising 98.2 g (0.182 mol) of compound (8) and 2.00 g (0.007 mol) of compound (9)) was placed in a flask, and a crescent-shaped stirring rod and a Liebig condenser with a receiver were attached. Furthermore, a concentration flask containing cesium fluoride dried at 150°C for 5 hours under vacuum was attached to the flask via an airless feed cock (manufactured by Asahi Seisakusho Co., Ltd.). The flask was removed from the space with a nitrogen atmosphere, and a three-one motor (manufactured by Shinto Scientific Co., Ltd., BLW300) was attached, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. Teflon (registered trademark) piping was installed so that the pressure between the concentration flask and the flask was equalized. The flask was placed in an oil bath (Tokyo Rikakikai Co., Ltd., OHB-3100S) set at 60°C, the pressure was reduced to 70 kPaA, and the mixture was stirred at 120 rpm for 10 minutes. Cesium fluoride was gradually added to the flask by operating the airless feed cock. It took 60 minutes to finish adding cesium fluoride to the flask. After the reaction was completed, the mass of the concentration flask with the airless feed cock attached was measured before and after the addition, and it was found that 47.5 g (0.313 mol) of cesium fluoride had been added. When cesium fluoride was added, the liquid gradually began to be distilled out, and when the rate of the liquid distilling into the receiver reached 2 drops / min, the pressure was gradually reduced, finally reaching 2 kPaA. When the liquid did not distill into the receiver for more than 2 minutes, the reaction was judged to be complete, the flask was removed from the oil bath, a nitrogen atmosphere was created, and the rotation of the three-one motor was stopped. The refrigerant flowing through the Liebig condenser was stopped, the receiver was returned to room temperature, and the mass of the fraction in the receiver was measured, which was 49.1 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed together, 19 F-NMR analysis revealed that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 48.6 g, product mass: 0.173 mol, production rate: 95.0%). In this example, β / α was 1.7. The residue remaining in the flask was collected and its mass was measured, which was 93.9 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and 19 The product was analyzed by F-NMR. As a result of the analysis, it was confirmed that fluorine-containing vinyl sulfonate (4) (a compound represented by formula (4) in which m is 0, n is 2, and M is Cs) was produced (amount produced: 75.4 g, product mass: 0.184 mol). In this example, the addition rate was 0.79 g / min, and the mass specific addition rate was 0.47 g / min / g.

[0126] [Comparative Example 1] Potassium fluoride (54.7 g, 0.941 mol) was placed in a flask equipped with a three-one motor (BLW300, manufactured by Shinto Scientific Co., Ltd.), a crescent-shaped stirring rod, and a Liebig condenser with a receiver attached, and placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.), dried at 150°C under vacuum for 5 hours, returned to room temperature, and placed in a nitrogen atmosphere. The mixed compound (8) (324.8 g, consisting of 318.3 g (0.591 mol) of compound (8) and 6.50 g (0.023 mol) of compound (9)) produced in Production Example 1 was added. A refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The pressure inside the flask was reduced to 50 kPaA, the three-one motor was rotated at 120 rpm, and the flask was placed in an oil bath set to 50°C. As the liquid did not start to distill off even after one hour had passed, the pressure was gradually reduced, at which point the liquid started to distill off, eventually reaching 2 kPaA. When no liquid was being distilled off into the receiver for more than two minutes, the reaction was deemed to have ended, the flask was removed from the oil bath, a nitrogen atmosphere was created, and the Three-One motor was stopped. The refrigerant flowing through the Liebig condenser was stopped, the receiver was returned to room temperature, and the mass of the fraction in the receiver was measured, which was 279.3 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed, 19F-NMR analysis revealed that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 40.2 g, product mass: 0.143 mol, production rate: 24.3%). In this example, β / α was 1.6.

[0127] [Comparative Example 2] Potassium fluoride (27.8 g, 0.479 mol) was placed in a flask equipped with a three-one motor (BLW300, manufactured by Shinto Scientific Co., Ltd.), a crescent-shaped stirring rod, and a Liebig condenser with a receiver attached, and placed in an oil bath (OHB-3100S, manufactured by Tokyo Rikakikai Co., Ltd.), dried at 150°C under vacuum for 5 hours, returned to room temperature, and placed in a nitrogen atmosphere. The mixed compound (8) (168.4 g, consisting of 165.0 g (0.307 mol) of compound (8) and 3.37 g (0.012 mol) of compound (9)) produced in Production Example 1 was added. A refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The pressure inside the flask was reduced to 95 kPaA, the three-one motor was rotated at 120 rpm, and the flask was placed in an oil bath set to 130°C. The liquid started to distill off, and when the rate of the liquid distilling off into the receiver reached 2 drops / min, the pressure was gradually reduced, finally reaching 2 kPaA. When no more liquid was distilling off into the receiver for more than 2 minutes, the reaction was deemed to have ended, the flask was removed from the oil bath, a nitrogen atmosphere was created, and the rotation of the Three-One motor was stopped. The refrigerant flowing through the Liebig condenser was stopped, the receiver was returned to room temperature, and the mass of the fraction in the receiver was measured, which was 100.3 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed, 19 F-NMR analysis revealed that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 53.9 g, product mass: 0.192 mol, production rate: 62.7%). In this example, β / α was 1.6.

[0128] As shown in Examples 1 to 8, in the reaction between fluorine-containing vinylsulfonic anhydride (1) and alkali metal fluoride (2), it was shown that fluorine-containing vinylsulfonic acid fluoride (3) can be obtained in high yield by adding alkali metal fluoride (2) to fluorine-containing vinylsulfonic anhydride (1) under heating. It was also shown that fluorine-containing vinylsulfonate (4) can be obtained.

[0129] [Example 9] 10.0 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1 was placed in a flask containing a stirrer, 36.9 g of acetonitrile was added, and the mixture was stirred for 30 minutes. The obtained solution was placed in a tank-attached stainless steel holder (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as filter paper) equipped with a flask at the outlet, pressurized to 0.2 MPaG with nitrogen, and filtered. The filtrate obtained in the flask was subjected to distillation of volatile components using a rotary evaporator (N-1300V, manufactured by Tokyo Rikakiki Co., Ltd.), and further vacuum-dried in a vacuum dryer (AVO-250V, manufactured by AS ONE Co., Ltd.) to obtain a solid. For analysis, the obtained solid (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed, and 19 F-NMR analysis confirmed that 9.02 g (28.5 mmol) of the fluorine-containing vinyl sulfonate (11) was obtained. In this example, γ / δ was 3.7.

[0130] [Example 10] 10.3 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1 was placed in a flask containing a stirrer, and 101.0 g of butyl acetate was added and stirred for 30 minutes. The obtained solution was placed in a tank-attached stainless steel holder (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as filter paper) equipped with a flask at the outlet, pressurized to 0.2 MPaG with nitrogen, and filtered. The filtrate obtained in the flask was subjected to distillation of volatile components using a rotary evaporator (N-1300V, manufactured by Tokyo Rikakiki Co., Ltd.), and further vacuum-dried in a vacuum dryer (AVO-250V, manufactured by AS ONE Co., Ltd.) to obtain a solid. For analysis, the obtained solid (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed, and 19 F-NMR analysis confirmed that 9.27 g (29.3 mmol) of the fluorine-containing vinyl sulfonate (11) was obtained. In this embodiment, γ / δ was 9.8.

[0131] [Example 11] 10.1 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1 was placed in a flask containing a stirrer, and 84.7 g of 4-methyl-2-pentanone was added and stirred for 30 minutes. The obtained solution was placed in a tank-attached stainless steel holder (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as filter paper) equipped with a flask at the outlet, pressurized to 0.2 MPaG with nitrogen, and filtered. The filtrate obtained in the flask was subjected to distillation of volatile components using a rotary evaporator (N-1300V, manufactured by Tokyo Rikakiki Co., Ltd.), and further vacuum-dried in a vacuum dryer (AVO-250V, manufactured by AS ONE Co., Ltd.) to obtain a solid. For analysis, the obtained solid (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed, and 19 F-NMR analysis confirmed that 9.06 g (28.7 mmol) of the fluorine-containing vinyl sulfonate (11) was obtained. In this example, γ / δ was 8.4.

[0132] [Example 12] 50.2 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1 was placed in a flask containing a stirrer, 117.6 g of dimethyl carbonate was added, and the mixture was stirred for 1 hour. The obtained solution was placed in a tank-attached stainless steel holder (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as filter paper) equipped with a flask at the outlet, pressurized to 0.2 MPaG with nitrogen, and filtered. The filtrate obtained in the flask was subjected to distillation of volatile components using a rotary evaporator (N-1300V, manufactured by Tokyo Rikakiki Co., Ltd.), and further vacuum-dried in a vacuum dryer (AVO-250V, manufactured by AS ONE Co., Ltd.) to obtain a solid. For analysis, the obtained solid (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed, and 19 F-NMR analysis confirmed that 45.1 g (0.143 mol) of the fluorine-containing vinyl sulfonate (11) was obtained. In this example, γ / δ was 2.3. The volatile components were removed by rotary evaporator. 1 Analysis by H-NMR confirmed that the main component was dimethyl carbonate. 30.0 g of the volatile component mainly composed of dimethyl carbonate was mixed with 10.0 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1, and the mixture was filtered in the same manner as described in this example. The volatile components were distilled off from the filtrate, and the mixture was dried in vacuum to obtain a solid. 19 F-NMR analysis confirmed that the fluorine-containing vinyl sulfonate (11) was obtained. The residue obtained on the filter paper by filtration was vacuum-dried using a vacuum dryer (AVO-250V, manufactured by AS ONE CORPORATION) to obtain 5.05 g of dried residue. In a space with a nitrogen atmosphere, 24.0 g of the mixed compound (8) produced in Production Example 1 (23.5 g (43.7 mmol) of compound (8) and 0.48 g (1.73 mmol) of compound (9)) was placed in a flask, and a half-moon-shaped stirring rod and a Liebig condenser with a receiver were attached. The concentrated flask containing the dried residue was attached to the flask via an airless feed cock (manufactured by Asahi Seisakusho Co., Ltd.). The flask was removed from the space with a nitrogen atmosphere, and a three-one motor (BLW300, manufactured by Shinto Scientific Co., Ltd.) was attached, a refrigerant at -5°C was circulated through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. Teflon (registered trademark) piping was installed so that the pressure between the concentration flask and the flask was equalized. The flask was placed in an oil bath (Tokyo Rikakikai Co., Ltd., OHB-3100S) set at 110°C, the pressure was reduced to 70 kPaA, and the mixture was stirred at 120 rpm for 10 minutes. The dried filtrate was gradually added to the flask by operating the cock of the airless feed cock. It took 10 minutes to finish adding the dried filtrate to the flask. When the dried filtrate was added, the liquid gradually began to be distilled, and when the rate of the liquid distilled into the receiver reached 2 drops / min, the pressure was gradually reduced and finally reached 2 kPaA. When the liquid did not distill into the receiver for more than 2 minutes, the reaction was judged to be complete, the flask was removed from the oil bath, and the atmosphere was changed to nitrogen, and the rotation of the three-one motor was stopped. The refrigerant flowing through the Liebig cooling tube was stopped, the receiver was returned to room temperature, and the mass of the fraction in the receiver was measured, which was 12.1 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed; 19 F-NMR analysis revealed that fluorine-containing vinyl sulfonic acid fluoride (10) was produced (amount produced: 11.0 g, product mass: 39.5 mmol, production rate: 90.2%). In this example, the addition rate was 0.42 g / min, and the mass specific addition rate was 1.1 g / min / g.

[0133] [Example 13] 10.1 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1 was placed in a flask containing a stirrer, 14.4 g of 1,2-dimethoxyethane was added, and the mixture was stirred for 1 hour. The obtained solution was placed in a tank-attached stainless steel holder (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as filter paper) equipped with a flask at the outlet, pressurized to 0.2 MPaG with nitrogen, and filtered. The filtrate obtained in the flask was subjected to distillation of volatile components using a rotary evaporator (N-1300V, manufactured by Tokyo Rikakiki Co., Ltd.), and further vacuum-dried in a vacuum dryer (AVO-250V, manufactured by AS ONE Co., Ltd.) to obtain a solid. For analysis, the obtained solid (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed, and 19 F-NMR analysis confirmed that 9.02 g (28.5 mmol) of the fluorine-containing vinyl sulfonate (11) was obtained. In this embodiment, γ / δ was 1.4.

[0134] [Example 14] 51.0 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1 was placed in a flask containing a stirrer, 108.4 g of dimethyl carbonate was added, and the mixture was stirred for 1 hour. The obtained solution was placed in a tank-equipped stainless steel holder (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as filter paper) equipped with a flask at the outlet, pressurized to 0.2 MPaG with nitrogen, and filtered. 100.0 g of the filtrate obtained in the flask was transferred to another flask, 55.7 g of purified water was added, and the volatile components were distilled off using a rotary evaporator (N-1300V, manufactured by Tokyo Rika Kiki Co., Ltd.) (the amount of the flask contents was 88.1 g). 55.7 g of purified water was added to the flask, and the volatile components were distilled off using a rotary evaporator (N-1300V, manufactured by Tokyo Rika Kiki Co., Ltd.) (the amount of the flask contents was 86.5 g). 55.7 g of purified water was added to the flask, and the volatile components were distilled off using a rotary evaporator (Tokyo Rikakiki Co., Ltd., N-1300V) (the amount of the flask contents was 85.7 g). For analysis, the obtained flask contents (1.00 g) were mixed with 2,2,2-trifluoroethanol (0.10 g), 19 F-NMR, and 1 The compound was analyzed by H-NMR. 19 As a result of F-NMR analysis, it was confirmed that the content of the flask contained 30.0 g of fluorine-containing vinyl sulfonate (11). 1 As a result of H-NMR analysis, no dimethyl carbonate was observed, confirming that the content of the flask was an aqueous solution of fluorine-containing vinyl sulfonate (11). When all the volatile components distilled off by the evaporator were collected, they were found to have separated into two phases. 1 Analysis by H-NMR confirmed that the lower phase was a phase mainly composed of dimethyl carbonate, and the upper phase was a layer mainly composed of water. Using a separatory funnel, the mixture was separated into a phase mainly composed of dimethyl carbonate (95.0 g) and a phase mainly composed of water (124.8 g). The moisture content of the phase mainly composed of dimethyl carbonate was analyzed using a Karl Fischer moisture meter (MKC-710D, manufactured by Kyoto Electronics Manufacturing Co., Ltd.), and the moisture content was 3.0% by mass. 11.1 g of the obtained phase mainly composed of dimethyl carbonate was mixed with 5.20 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1, and the mixture was filtered in the same manner as described in this example. The volatile components were distilled off from the filtrate, and the mixture was dried in vacuum to obtain a solid. 19 F-NMR analysis confirmed that the fluorine-containing vinyl sulfonate (11) was obtained. The obtained phase (84.0 g) mainly composed of dimethyl carbonate was placed in a flask of a distillation apparatus, and the volatile components were distilled off (the amount of the flask contents was 67.4 g). The moisture content of the obtained flask contents was analyzed using a Karl Fischer moisture meter (MKC-710D, manufactured by Kyoto Electronics Manufacturing Co., Ltd.), and the moisture content was found to be 1.0 mass%, indicating that a phase mainly composed of dimethyl carbonate with a reduced moisture content had been prepared. 20.8 g of the phase mainly composed of dimethyl carbonate with a reduced moisture content was mixed with 9.80 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1, and the mixture was filtered in the same manner as described in this example, and the volatile components were distilled off from the filtrate, followed by vacuum drying to obtain a solid. The obtained solid was 19 F-NMR analysis confirmed that the fluorine-containing vinyl sulfonate (11) was obtained. 39.8 g of an aqueous solution of the fluorinated vinyl sulfonate (11) (containing 13.9 g (44.1 mmol) of the fluorinated vinyl sulfonate (11)) was placed in a separable flask, and sulfuric acid (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) (8.64 g) was gradually added with stirring. Next, cyclopentyl methyl ether (Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) (27.9 g) was added, and the mixture was stirred for 1 hour and then allowed to stand for 2 hours. The upper cyclopentyl methyl ether phase (1.0 g) was taken out, 19 F-NMR analysis confirmed that compound (9) was obtained.

[0135] [Example 15] 39.9 g of the fluorine-containing vinyl sulfonic acid fluoride (10) obtained in Example 1 was placed in a flask of a distillation apparatus (Sulzer EX Laboratory Packing manufactured by Sulzer was used as a packing material) and distilled. 1.93 g was separated as an initial stream, and then 34.7 g of a fraction was obtained. The obtained fraction (0.30 g), hexafluorobenzene (3.00 g), and benzotrifluoride (0.10 g) were mixed and analyzed by GC, and the purity of the fluorine-containing vinyl sulfonic acid fluoride (10) was 99.9%.

[0136] [Example 16] 39.6 g of the fluorine-containing vinylsulfonic acid fluoride (10) obtained in Example 1 and 19.8 g of purified water were placed in a flask equipped with a stirrer, stirred for 30 minutes, and then placed in a separatory funnel and allowed to stand for 30 minutes to obtain an upper phase (20.2 g) and a lower phase (38.7 g). For analysis, the obtained lower phase (0.30 g), 1,2-dimethoxyethane (1.00 g), and benzotrifluoride (0.10 g) were mixed, 19 The results were analyzed by F-NMR. 19 F-NMR analysis confirmed that the collected lower phase contained 37.8 g of fluorine-containing vinyl sulfonyl fluoride (10). In this example, ζ / ε was 0.50. The lower phase was placed in a flask of a distillation apparatus (Sulzer EX Laboratory Packing, manufactured by Sulzer, was used as a packing material) and distilled. 3.10 g was separated as the initial stream, and then 32.5 g of a fraction was obtained. The obtained fraction (0.30 g), hexafluorobenzene (3.00 g), and benzotrifluoride (0.10 g) were mixed and analyzed by GC, and the purity of the fluorine-containing vinyl sulfonyl fluoride (10) was 99.9%. The obtained upper phase (10.3 g) and 10.1 g of the fluorine-containing vinyl sulfonic acid fluoride (10) obtained in Example 1 were placed in a flask equipped with a stirrer, stirred for 30 minutes, and then placed in a separatory funnel and allowed to stand for 30 minutes to obtain a lower phase (9.91 g). The obtained lower phase (0.30 g), 1,2-dimethoxyethane (1.00 g), and benzotrifluoride (0.10 g) were mixed, 19 The results were analyzed by F-NMR.19 F-NMR analysis confirmed that the collected lower phase contained 9.64 g of fluorine-containing vinyl sulfonyl fluoride (10).

[0137] [Example 17] 40.5 g of the fluorine-containing vinylsulfonic acid fluoride (10) obtained in Example 1 and 40.5 g of an aqueous sodium hydrogen carbonate solution were placed in a flask equipped with a stirrer, stirred for 30 minutes, and then placed in a separatory funnel and allowed to stand for 30 minutes to obtain an upper phase (40.5 g) and a lower phase (39.3 g). For analysis, the obtained lower phase (0.30 g), 1,2-dimethoxyethane (1.00 g), and benzotrifluoride (0.10 g) were mixed, 19 The results were analyzed by F-NMR. 19 F-NMR analysis confirmed that the collected lower phase contained 38.6 g of fluorine-containing vinyl sulfonyl fluoride (10). In this example, ζ / ε was 1.0. The lower phase was placed in a flask of a distillation apparatus (Sulzer EX Laboratory Packing, manufactured by Sulzer, was used as a packing material) and distilled. 2.56 g was separated as the initial stream, and then 33.6 g of a fraction was obtained. The obtained fraction (0.30 g), hexafluorobenzene (3.00 g), and benzotrifluoride (0.10 g) were mixed and analyzed by GC, and the purity of the fluorine-containing vinyl sulfonyl fluoride (10) was 99.9%. The obtained upper phase (20.4 g) and 10.2 g of the fluorine-containing vinyl sulfonic acid fluoride (10) obtained in Example 1 were placed in a flask equipped with a stirrer, stirred for 30 minutes, and then placed in a separatory funnel and allowed to stand for 30 minutes to obtain a lower phase (9.94 g). The obtained lower phase (0.30 g), 1,2-dimethoxyethane (1.00 g), and benzotrifluoride (0.10 g) were mixed, 19 The results were analyzed by F-NMR. 19 F-NMR analysis confirmed that the collected lower phase contained 9.73 g of fluorine-containing vinyl sulfonyl fluoride (10).

[0138] [Example 18] 10.6 g of the fluorine-containing vinylsulfonic acid fluoride (10) obtained in Example 1 and 53.0 g of an aqueous sodium hydrogen carbonate solution were placed in a flask equipped with a stirrer, stirred for 30 minutes, and then placed in a separatory funnel and allowed to stand for 30 minutes to obtain an upper phase (52.6 g) and a lower phase (10.3 g). For analysis, the obtained lower phase (0.30 g), 1,2-dimethoxyethane (1.00 g), and benzotrifluoride (0.10 g) were mixed, 19 The results were analyzed by F-NMR. 19 F-NMR analysis confirmed that the collected lower phase contained 10.1 g of fluorine-containing vinyl sulfonyl fluoride (10). In this example, ζ / ε was 5.0.

[0139] As shown in Examples 9 to 18, it was demonstrated that fluorine-containing vinylsulfonic acid fluoride (3) or fluorine-containing vinylsulfonate (4) obtained by reacting fluorine-containing vinylsulfonic acid anhydride (1) with alkali metal fluoride (2) can be separated. It was also demonstrated that the compounds used in the separation can be reused. [Industrial Applicability]

[0140] According to the production method of the present invention, fluorine-containing vinyl sulfonyl fluoride (3) can be produced in a higher yield than in the past, and therefore can be suitably used in the production of raw materials for various fluorine-containing compounds, ion exchange resins, ion exchange membranes, sodium chloride electrolysis membranes, fuel cell membranes, membranes for redox flow batteries, membranes for water electrolysis, etc. Also, fluorine-containing vinyl sulfonate (4) which can be converted into various fluorine compounds can be produced. Furthermore, fluorine-containing vinyl sulfonate (3) and / or fluorine-containing vinyl sulfonate (4) can be separated, and the compounds used in the separation can be reused.

Claims

1. The following general formula (3): 【Chemistry 1】 (wherein m is an integer from 0 to 3, and n is an integer from 1 to 6). Fluorine-containing vinyl sulfonic acid fluoride (3) represented by the formula: The following general formula (4): 【Chemistry 2】 (In the formula, m is an integer of 0 to 3, n is an integer of 1 to 6, and M is K, Rb, or Cs.) The present invention relates to a method for producing a fluorine-containing vinyl sulfonate (4) represented by the following formula: The following general formula (1): 【Chemistry 3】 (wherein m is an integer from 0 to 3, and n is an integer from 1 to 6). A fluorine-containing vinyl sulfonic anhydride (1) represented by the formula: The following general formula (2): Midfielder (2) (In the formula, M is K, Rb, or Cs.) In a reaction with an alkali metal fluoride (2) represented by An alkali metal fluoride (2) is added to a fluorine-containing vinyl sulfonic anhydride (1) under heating. A manufacturing method comprising:

2. The method according to claim 1, wherein the reaction temperature is 60 to 250° C.

3. The production method according to claim 1 or 2, wherein a ratio (β / α) of the amount of substance (β) of the alkali metal fluoride (2) to the amount of substance (α) of the fluorine-containing vinyl sulfonic anhydride (1) is 1 to 100.

4. The following general formula (3): 【Chemistry 4】 (wherein m is an integer from 0 to 3, and n is an integer from 1 to 6). The method according to claim 1, which is a method for producing a fluorine-containing vinyl sulfonic acid fluoride (3) represented by the following formula:

5. The following general formula (4): 【Chemistry 5】 (In the formula, m is an integer of 0 to 3, n is an integer of 1 to 6, and M is K, Rb, or Cs.) The method according to claim 1, which is a method for producing a fluorine-containing vinyl sulfonate (4) represented by the following formula:

6. The method according to claim 1, further comprising a step of separating the fluorine-containing vinyl sulfonic acid fluoride (3).

7. The method according to claim 6, further comprising a step of distilling the fluorine-containing vinyl sulfonic acid fluoride (3).

8. The method according to claim 6, further comprising a step of mixing the fluorine-containing vinyl sulfonic acid fluoride (3) with an extraction compound.

9. The method according to claim 8, wherein the extract compound is at least one compound selected from the group consisting of water, an aqueous solution containing an inorganic salt, an alcohol compound, an amide compound, and a sulfo compound.

10. The method according to claim 9, wherein the inorganic salt-containing aqueous solution is an aqueous solution containing at least one inorganic salt compound selected from the group consisting of carbonates, sulfates, thiosulfates, acetates, phosphates, citrates, tartrates, and tetraborates.

11. The production method according to claim 8, wherein the ratio (ζ / ε) of the mass (ζ) of the extracted compound to the mass (ε) of the fluorinated vinyl sulfonic acid fluoride (3) is 0.1 to 100.

12. The production method according to claim 8, further comprising a step of allowing the mixed solution obtained in the step of mixing the fluorinated vinyl sulfonic acid fluoride (3) with the extract compound to stand and separating the mixed solution into a phase containing the fluorinated vinyl sulfonic acid fluoride (3) and a phase containing the extract compound.

13. The method according to claim 12, wherein the phase containing the extracted compound is recycled to the step of mixing the fluorine-containing vinyl sulfonic acid fluoride (3) with the extracted compound.

14. The method according to claim 12, further comprising a step of separating the fluorine-containing vinylsulfonic acid fluoride (3) from the phase containing the fluorine-containing vinylsulfonic acid fluoride (3) by distillation.

15. The process of claim 1, further comprising the step of separating the reaction residue.

16. The production method according to claim 15, comprising a step of mixing the reaction residue with a dissolving compound to prepare a fluorine-containing sulfonate solution.

17. The method according to claim 16, wherein the dissolving compound is at least one compound selected from the group consisting of an ether compound, a ketone compound, an ester compound, a carbonate compound, and a nitrile compound.

18. The method according to claim 16, wherein the ratio (δ / γ) of the mass (δ) of the dissolved compound to the mass (γ) of the reaction residue is 0.01 to 100.

19. The method according to claim 16, further comprising a step of filtering the solution of the fluorine-containing sulfonate to obtain a filtrate containing the fluorine-containing sulfonate.

20. The method according to claim 16, further comprising a step of filtering the fluorine-containing sulfonate solution to obtain a residue containing the alkali metal fluoride (2).

21. The production method according to claim 20, wherein the filtrate containing the alkali metal fluoride (2) is reused in the reaction of the fluorine-containing vinyl sulfonic anhydride (1) with the alkali metal fluoride (2).

22. The production method according to claim 19, further comprising a step of separating a volatile component containing the dissolved compound from the fluorine-containing sulfonate-containing filtrate to obtain the fluorine-containing vinyl sulfonate (4).

23. The production method according to claim 22, wherein the volatile components containing the dissolved compound are reused in the step of mixing the reaction residue with the dissolved compound and preparing a fluorine-containing sulfonate solution.

24. The production method according to claim 19, comprising a step of adding water to the filtrate containing the fluorine-containing sulfonate and mixing the same.

25. The method according to claim 24, wherein a ratio (κ / ι) of the mass (ι) of the fluorine-containing sulfonate-containing filtrate to the total mass (κ) of water is 0.1 to 100.

26. The production method according to claim 24, further comprising a step of separating a volatile component containing the dissolved compound from a solution obtained by adding water to the fluorine-containing sulfonate-containing filtrate and mixing the solution, thereby preparing an aqueous solution containing the fluorine-containing sulfonate.

27. The production method according to claim 26, further comprising a step of separating a volatile component containing the dissolved compound from a solution obtained by a step of adding water to the fluorine-containing sulfonate-containing filtrate and mixing the filtrate, and separating water from the volatile component containing the dissolved compound separated in the step of preparing an aqueous solution containing a fluorine-containing sulfonate.

28. 28. The production method according to claim 26 or 27, wherein the volatile components containing the dissolved compound are reused in the step of mixing the reaction residue with the dissolved compound and preparing a fluorine-containing sulfonate solution.

29. The production method according to claim 24, wherein a volatile component containing the dissolved compound is separated from a solution obtained by a step of adding water to and mixing with the fluorine-containing sulfonate-containing filtrate, and the water separated in a step of separating water from the volatile component containing the dissolved compound separated in the step of preparing an aqueous solution containing a fluorine-containing sulfonate is reused in the step of adding water to and mixing with the fluorine-containing sulfonate-containing filtrate.

Images