JP7598260B2 - Method for producing fluorine-containing vinyl sulfonic acid fluoride or fluorine-containing vinyl sulfonate salt, and method for separating same - Google Patents

Description

The present invention relates to a method for producing fluorine-containing vinyl sulfonic acid fluoride or a fluorine-containing vinyl sulfonate salt, and a separation method. It also relates to a method for reusing compounds used in the separation method.

（ｐは０～６の整数、ｑは１～６の整数）
一般式（５）で表されるフッ素系高分子電解質は、下記一般式（６）で表される含フッ素ビニルスルホン酸フルオリド（６）とテトラフルオロエチレン（ＴＦＥ）との共重合体をケン化反応及び酸処理を施すことによって製造できることが知られている。

（ｐは０～６の整数、ｑは１～６の整数）
上記一般式（６）で表される含フッ素ビニルスルホン酸フルオリド（６）の製造方法として、下記一般式（１）：

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸無水物（１）と、
フッ化水素、金属フッ化物、４級アンモニウムフルオリド、及び４級ホスホニウムフルオリドからなる群より選択される１種以上であるフッ素化剤とを、
接触・混合させることにより、下記一般式（３）：

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸フルオリド（３）を製造する方法が開示されている（特許文献１）。また、該特許文献では、前記含フッ素ビニルスルホン酸フルオリド（３）を製造する際、同時に下記一般式（４）：

（式中、ｍは０～３の整数、ｎは１～６の整数、Ｍ^２はＬｉ、Ｎａ、Ｋ、Ｒｂ、又はＣｓである。）
で表される含フッ素ビニルスルホン酸塩（４）を製造できることが開示されている。さらに、前記含フッ素ビニルスルホン酸塩（４）を再利用し、前記含フッ素ビニルスルホン酸フルオリド（３）を製造する方法も開示されている。また、含フッ素ビニルスルホン酸塩（４）は、別法によっても含フッ素ビニルスルホン酸フルオリド（３）に変換できることが開示されており、有用な化合物であることが知られている（特許文献２）。 Conventionally, a fluoropolymer electrolyte (5) represented by the following general formula (5) has been mainly used as a main component of a membrane for a fuel cell, a catalyst binder polymer for a fuel cell, a membrane for salt electrolysis, and the like.

(p is an integer from 0 to 6, and q is an integer from 1 to 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.

(p is an integer from 0 to 6, and q is an integer from 1 to 6)
The fluorine-containing vinyl sulfonic acid fluoride (6) represented by the above general formula (6) can be produced by a method represented by the following general formula (1):

(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:
a fluorinating agent which is at least one selected from the group consisting of hydrogen fluoride, a metal fluoride, a quaternary ammonium fluoride, and a quaternary phosphonium fluoride;
By contacting and mixing, a compound represented by the following general formula (3):

(wherein m is an integer from 0 to 3, and n is an integer from 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):

(In the formula, m is an integer from 0 to 3, n is an integer from 1 to 6, and ^M2 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 another method, and it is known to be a useful compound (Patent Document 2).

International Publication No. 2020/012913 U.S. Pat. No. 3,560,568

Patent Document 1 discloses a method for producing fluorine-containing vinyl sulfonic acid fluoride (3) and fluorine-containing vinyl sulfonate (4) by reacting fluorine-containing vinyl sulfonic acid anhydride (1) with sodium fluoride or potassium fluoride, where m = 0 and n = 2. However, there is a demand for a production method that can obtain fluorine-containing vinyl sulfonic acid fluoride (3), which is a raw material for the fluorine-based polymer electrolyte (5), in a higher yield. There is also a demand for a method for separating fluorine-containing vinyl sulfonic acid fluoride (3) and fluorine-containing vinyl sulfonate (4).

As a result of intensive research to solve the above-mentioned problems, the present inventors have found that the above-mentioned object can be achieved by adding fluorine-containing vinyl sulfonic anhydride (1) (hereinafter also referred to as "compound (1)") to alkali metal fluoride (2) (hereinafter also referred to as "compound (2)") under heating in the reaction between the fluorine-containing vinyl sulfonic anhydride (1) and the alkali metal fluoride (2), thereby completing the present invention. In addition, the present inventors have also found a method for separating fluorine-containing vinyl sulfonic acid fluoride (3) and fluorine-containing vinyl sulfonate (4), and a method for reusing the compounds and the like used in the separation.

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸フルオリド（３）、又は
下記一般式（４）：

（式中、ｍは０～３の整数、ｎは１～６の整数、ＭはＫ、Ｒｂ、又はＣｓである。）
で表される含フッ素ビニルスルホン酸塩（４）の製造方法であり、
下記一般式（１）：

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸無水物（１）を、
下記一般式（２）：
ＭＦ （２）
（式中、Ｍは、Ｋ、Ｒｂ、又はＣｓである。）
で表されるアルカリ金属フッ化物（２）に、加熱下で添加して反応させる、
ことを特徴とする、製造方法。
［２］
前記反応の反応温度が、６０～２５０℃、である、［１］に記載の製造方法。
［３］
前記含フッ素ビニルスルホン酸無水物（１）の物質量（α）と前記アルカリ金属フッ化物（２）の物質量（β）の比率（β／α）が、１～１００、である、［１］又は［２］に記載の製造方法。
［４］
下記一般式（３）：

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸フルオリド（３）の製造方法である、［１］に記載の製造方法。
［５］
下記一般式（４）：

（式中、ｍは０～３の整数、ｎは１～６の整数、ＭはＫ、Ｒｂ、又はＣｓである。）
で表される含フッ素ビニルスルホン酸塩（４）の製造方法である、［１］に記載の製造方法。
［６］
前記含フッ素ビニルスルホン酸フルオリド（３）を分離する工程を含む、［１］に記載の製造方法。
［７］
前記含フッ素スルホン酸フルオリド（３）を蒸留する工程を含む、［６］に記載の製造方法。
［８］
前記含フッ素スルホン酸フルオリド（３）と、抽出化合物とを混合する工程を含む、［６］に記載の製造方法。
［９］
前記抽出化合物が、水、無機塩含有水溶液、アルコール化合物、アミド化合物、及びスルホ化合物からなる群より選ばれる少なくとも１種の化合物である、［８］に記載の製造方法。
［１０］
前記無機塩含有水溶液が、炭酸塩類、硫酸塩類、チオ硫酸塩類、酢酸塩類、リン酸塩類、クエン酸塩類、酒石酸塩類、及び四ホウ酸塩類からなる群より選ばれる少なくとも１種の無機塩化合物を含む水溶液である、［９］に記載の製造方法。
［１１］
前記含フッ素スルホン酸フルオリド（３）の質量（ε）に対する前記抽出化合物の質量（ζ）の比率（ζ／ε）が、０．１～１００、である、［８］に記載の製造方法。
［１２］
前記含フッ素スルホン酸フルオリド（３）と、抽出化合物とを混合する工程により得られた混合溶液を、静置し、前記含フッ素スルホン酸フルオリド（３）を含む相と、前記抽出化合物を含む相とに分離する工程を含む、［８］に記載の製造方法。
［１３］
前記抽出化合物を含む相を、前記含フッ素スルホン酸フルオリド（３）と、抽出化合物とを混合する工程に再利用する、［１２］に記載の製造方法。
［１４］
前記含フッ素スルホン酸フルオリド（３）を含む相から、含フッ素スルホン酸フルオリド（３）を、蒸留により分離する工程を含む、［１２］に記載の製造方法。
［１５］
反応残渣を分離する工程を含む、［１］に記載の製造方法。
［１６］
前記反応残渣と、溶解化合物とを混合し、含フッ素スルホン酸塩溶解液を調整する工程を含む、［１５］に記載の製造方法。
［１７］
前記溶解化合物が、エーテル化合物、ケトン化合物、エステル化合物、カーボネート化合物、及びニトリル化合物からなる群より選ばれる少なくとも１種の化合物である、［１６］に記載の製造方法。
［１８］
前記反応残渣の質量（γ）に対する前記溶解化合物の質量（δ）の比率（δ／γ）が、０．０１～１００である、［１６］に記載の製造方法。
［１９］
前記含フッ素スルホン酸塩溶解液をろ過し、含フッ素スルホン酸塩含有ろ液を得る工程を含む、［１６］に記載の製造方法。
［２０］
前記含フッ素スルホン酸塩溶解液をろ過し、アルカリ金属フッ化物（２）を含むろ物を得る工程を含む、［１６］に記載の製造方法。
［２１］
前記アルカリ金属フッ化物（２）を含むろ物を、前記含フッ素ビニルスルホン酸無水物（１）と反応させる際に再利用する、［２０］に記載の製造方法。
［２２］
前記含フッ素スルホン酸塩含有ろ液から、前記溶解化合物を含む揮発成分を分離し、前記含フッ素スルホン酸塩（４）を得る工程を含む
ことを特徴とする、［１９］に記載の製造方法。
［２３］
前記溶解化合物を含む揮発成分を、前記反応残渣と、溶解化合物とを混合し、含フッ素スルホン酸塩溶解液を調整する工程に再利用する、［２２］に記載の製造方法。
［２４］
前記含フッ素スルホン酸塩含有ろ液に、水を添加し、混合する工程を含む、［１９］に記載の製造方法。
［２５］
前記含フッ素スルホン酸塩含有ろ液の質量（ι）と水の総質量（κ）の比率（κ／ι）が、０．１～１００である、［２４］に記載の製造方法。
［２６］
前記含フッ素スルホン酸塩含有ろ液に、水を添加し、混合する工程により得られた溶液から、前記溶解化合物を含む揮発成分を分離し、含フッ素スルホン酸塩含有水溶液を調整する工程を含む、［２４］に記載の製造方法。
［２７］
前記含フッ素スルホン酸塩含有ろ液に、水を添加し、混合する工程により得られた溶液から、前記溶解化合物を含む揮発成分を分離し、含フッ素スルホン酸塩含有水溶液を調整する工程において分離した前記溶解化合物を含む揮発成分から、水を分離する工程を含む、［２６］に記載の製造方法。
［２８］
前記溶解化合物含む揮発成分を、前記反応残渣と、溶解化合物とを混合し、含フッ素スルホン酸塩溶解液を調整する工程に再利用する、［２６］又は［２７］に記載の製造方法。
［２９］
前記含フッ素スルホン酸塩含有ろ液に、水を添加し、混合する工程により得られた溶液から、前記溶解化合物を含む揮発成分を分離し、含フッ素スルホン酸塩含有水溶液を調整する工程において分離した前記溶解化合物を含む揮発成分から、水を分離する工程において分離した水を、前記含フッ素スルホン酸塩含有ろ液に、水を添加し、混合する工程に再利用する、［２４］に記載の製造方法。 That is, the present invention is as follows.
[1]
The following general formula (3):

(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 following general formula (4):

(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):

(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 following formula:
The following general formula (2):
Midfielder (2)
(In the formula, M is K, Rb, or Cs.)
and reacting the resulting mixture with an alkali metal fluoride (2) represented by the formula:
A manufacturing method comprising:
[2]
The 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 (α) of the fluorinated vinyl sulfonic anhydride (1) to the amount of substance (β) of the alkali metal fluoride (2) is 1 to 100.
[4]
The following general formula (3):

(wherein m is an integer from 0 to 3, and n is an integer from 1 to 6).
The method for producing a fluorinated vinyl sulfonic acid fluoride (3) represented by the formula (1) is described below.
[5]
The following general formula (4):

(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], further comprising a step of distilling the fluorine-containing sulfonic acid fluoride (3).
[8]
The method for producing a fluorine-containing sulfonic acid fluoride (3) according to [6], further 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 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], further comprising a step of allowing the mixed solution obtained by the step of mixing the fluorine-containing sulfonic acid fluoride (3) with the extract compound to stand and separating the mixed solution into a phase containing the fluorine-containing sulfonic acid fluoride (3) and a phase containing the extract compound.
[13]
The production method according to [12], wherein the phase containing the extracted compound is reused in the step of mixing the fluorine-containing 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 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 [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 [16], further comprising a step of filtering the fluorine-containing sulfonate solution to obtain a residue containing the alkali metal fluoride (2).
[21]
The method according to [20], wherein the filter cake containing the alkali metal fluoride (2) is reused in the reaction with the fluorine-containing vinyl sulfonic anhydride (1).
[22]
The production method according to [19], comprising a step of separating a volatile component containing the dissolved compound from the fluorine-containing sulfonate-containing filtrate to obtain the fluorine-containing sulfonate (4).
[23]
The production method according to [22], wherein the volatile components containing the dissolved compound are reused in a step of mixing the reaction residue with the dissolved compound to prepare a fluorine-containing sulfonate solution.
[24]
The method according to [19], further comprising a step of adding water to the filtrate containing the fluorine-containing sulfonate and mixing the filtrate.
[25]
The production method according to [24], wherein the 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 [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 a volatile component containing the dissolved compound 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 component containing the dissolved compound separated in the step of adjusting 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 reused in a step of mixing the reaction residue with the dissolved compound to prepare 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.

According to the present invention, fluorine-containing vinyl sulfonic acid fluoride (3) can be produced in high yield. In addition, 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 used in the separation can be reused.

The following provides a detailed description of the embodiment of the present invention (hereinafter, referred to as the "present embodiment"). However, the present invention is not limited to the present embodiment, and can be modified in various ways within the scope of the gist of the present invention.

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸フルオリド（３）、又は
下記一般式（４）：

（式中、ｍは０～３の整数、ｎは１～６の整数、ＭはＫ、Ｒｂ、又はＣｓである。）
で表される含フッ素ビニルスルホン酸塩（４）の製造方法であり、
下記一般式（１）：

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される含フッ素ビニルスルホン酸無水物（１）を、
下記一般式（２）：
ＭＦ （２）
（式中、Ｍは、Ｋ、Ｒｂ、又はＣｓである。）
で表されるアルカリ金属フッ化物（２）に、加熱下で添加して反応させる、
ことを特徴とする。 The manufacturing method of this embodiment is as follows:
The following general formula (3):

(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 following general formula (4):

(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):

(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 following formula:
The following general formula (2):
Midfielder (2)
(In the formula, M is K, Rb, or Cs.)
and reacting the resulting mixture with an alkali metal fluoride (2) represented by the formula:
It is characterized by:

Details of the reaction conditions for producing compounds (1), (2), (3), or (4) are described below.

（式中、ｍは０～３の整数、ｎは１～６の整数）
で表される。
含フッ素ビニルスルホン酸無水物（１）は、１種単独であっても、複数種を組み合わせて用いてもよい。 <Fluorine-containing vinyl sulfonic anhydride (1) (compound (1))>
The fluorine-containing vinyl sulfonic anhydride (1) is represented by the following general formula (1):

(wherein m is an integer from 0 to 3, and n is an integer from 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.

As m, 0 to 1 is preferable, and 0 is more preferable, since it tends to be easily available or produced and is economically superior.
As n, it is preferable that n is 1 to 4, more preferably 2 to 4, and even more preferably 2, because n is easily available or produced and tends to be economical.
A particularly preferred combination of m and n is m=0 and n=2.

The method for producing the fluorine-containing vinyl sulfonic anhydride (1) is not particularly limited, and it can be produced by a conventionally known method. For example, it can be produced by the method described in WO 2020/012913.

<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 fluoride (2) may be used alone or in combination of two or more kinds.

As M, K or Cs is more preferred because they are easily available and tend to be economical, and K is even more preferred from the same perspective.

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 the 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. In addition, since there is a tendency to promote the 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.

When the fluorine-containing vinyl sulfonic anhydride (1) is reacted with the alkali metal fluoride (2), for example, an ether compound, a nitrile compound, an amide compound, a sulfo compound, a saturated hydrocarbon compound, an aromatic hydrocarbon compound, a halogenated hydrocarbon compound, an alcohol compound, a ketone compound, an ester compound, water, or the like can be used as an additive, if necessary.
The additives may be used alone or in combination of two or more.
The 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).

The additive is not particularly limited as long as it is a commonly used compound, but specific examples 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, Nitrile compounds such as propionitrile, butyronitrile, 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-methyl amide compounds such as dimethylsulfoxide, dibutylsulfoxide, ethylmethylsulfone, ethylisopropylsulfone, sulfolane, and 3-methylsulfolane; 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, Examples of the organic solvent include halogenated hydrocarbon compounds such as benzene, trichlorobenzene, chlorotoluene, and chloronaphthalene; alcohol compounds such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, cyclohexanol, and benzyl alcohol; ketone compounds such as acetone, methylacetone, ethyl methyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl hexyl ketone, diethyl ketone, ethyl butyl ketone, dipropyl ketone, diisobutyl ketone, and cyclohexanone; and 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.

The additives may have 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.

<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, and further preferably 1 or more, since the amount of unreacted compound (1) tends to be suppressed.

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 preferable that β/α is 100 or less, and from the same viewpoint, it is more preferable that β/α is 50 or less, and even more preferable that β/α is 10 or less.

<Reaction of Compound (1) and Compound (2)>
In the present embodiment, the reaction temperature refers to the temperature at which a container containing compound (2) 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 is suppressed, and the method for producing compound (3) tends to be economically advantageous. For this reason, the temperature is more preferably 200° C. or lower, even more preferably 170° C. or lower, and particularly preferably 160° C. or lower.
The reaction temperature of the compound (1) and the compound (2) does not need to be constant so long as it is within the above range, and may be changed during the reaction.

The time for adding compound (1) to compound (2) is not particularly limited as long as it is within the range generally used, but from the viewpoint of suppressing side reactions due to the rapid reaction of compound (1) with compound (2), it is preferably 5 minutes or more, more preferably 10 minutes or more, and even more preferably 15 minutes or more. In addition, by avoiding an excessive addition time in which 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, a manufacturing method with better economics tends to be obtained. Therefore, the time for adding compound (1) to compound (2) is preferably 100 hours or less, more preferably 50 hours or less, even more preferably 10 hours or less, and particularly preferably 5 hours or less.

The rate of adding compound (1) to compound (2) (meaning the value obtained by dividing the mass of compound (1) used by the time of addition) is not particularly limited as long as it is within a commonly used range, but since 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, 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 rapid reaction of compound (1) and compound (2), the rate of adding compound (1) to compound (2) is preferably 1000 g/min or less, more preferably 100 g/min or less, even more preferably 50 g/min or less, and particularly preferably 30 g/min or less.
The rate at which compound (1) is added to compound (2) does not need to be constant as long as it is within the above range, and may be changed during the process. At the beginning of the addition of compound (1), the reaction between compound (1) and compound (2) is likely to occur, but at the later stage of the addition of compound (1), the reaction between compound (1) and compound (2) is unlikely to occur. Therefore, it may be preferable to slow down the addition rate at the beginning of the addition and increase the addition rate toward the later stage of the addition.

The rate of addition of compound (1) to compound (2) (meaning the value obtained by dividing the time for adding the mass of compound (1) used by the mass of compound (2) used) is not particularly limited as long as it is within a commonly used range. However, since a production method with better economic efficiency tends to be achieved by avoiding an excessive addition time in which the reaction of compound (1) is completed and compound (1) no longer exists, and a state in which compound (1) and compound (2) do not react continues for a long time, the rate is preferably 0.01 g/min/g or more, more preferably 0.1 g/min/g or more, even more preferably 0.5 g/min/g or more, and particularly preferably 1 g/min/g or more. From the viewpoint of suppressing a side reaction due to a rapid reaction between compound (1) and compound (2), the rate at which compound (1) is added to compound (2) is preferably 1000 g/min/g or less, more preferably 100 g/min/g or less, even more preferably 50 g/min/g or less, and particularly preferably 30 g/min/g or less.
The rate at which compound (1) is added to compound (2) does not need to be constant so long as it is within the above range, and may be changed during the addition.

After the addition of compound (1) is completed, the time for reacting the mixture containing 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 avoiding an excessive reaction time 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.

The pressure when reacting compound (1) with compound (2) is not particularly limited as long as it is within the range normally used, and may be pressurized, atmospheric pressure, or 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, pressurization to atmospheric pressure or higher is an effective method. If the resulting compound (3) is to be 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.

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 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 (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 the separation of compound (3).
The reaction atmosphere may be used alone or in combination of a plurality of reaction atmospheres.

The method used in 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 system (horizontal type, vertical type), the number of stirring shafts (two shafts, three shafts, four shafts), the shape of a stirring blade (for example, fan, propeller, cross, butterfly, dragonfly, turbine, disk 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 a 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, all of which are manufactured by Nihon Spindle Mfg. Co., Ltd.; a KRC kneader, batch kneader, pressure kneader, extruder, CD dryer, SC processor, and CD dryer, all of which are manufactured by Kurimoto Iron Works, Ltd.; and a BDM twin-screw mixer, butterfly mixer, CDM concentric twin-screw mixer, pony mixer, and trimmer, all of which are manufactured by Inoue Seisakusho Co., Ltd. Mixer, planetary mixer, PD mixer, kneader, flushing kneader, salt milling kneader, pressure kneader, and KX kneader manufactured by Pacific Machinery Co., Ltd., Pam Apex mixer, Super double mixer, vertical mixer, ribbon mixer, high-speed paddle mixer, and paddle mixer manufactured by Nishimura Machinery Co., Ltd., Byte mix, Nauta mixer, Solid air, Micron thermo processor, and Torus disk manufactured by Hosokawa Micron Co., Ltd., paddle dryer, single paddle dryer, Buno cooler, multi-fin processor, extruder, and high-speed stirring mixer granulator manufactured by Nara Machinery Co., Ltd., PV mixer, and S manufactured by Kobelco Eco-Solutions Co., Ltd. V mixer, Ribocone and Flowjet granulator manufactured by Okawara Manufacturing Co., Ltd., twin-screw kneading extruder manufactured by Japan Steel Works, Ltd., Hivismix, Hivisdispermix, and Combimix manufactured by Primix Corporation, ACM series manufactured by Aikosha Manufacturing Co., Ltd., mixer, twin servo mixer, S kneader, spherical kneader, spherical inclined axis kneader, and high-speed kneading granulator manufactured by Shinagawa Kogyosho Co., Ltd., intensive mixer and Evactherm manufactured by Nippon Eirich Co., Ltd., axial mixer and Hemisphere mixer manufactured by Sugiyama Heavy Industries Co., Ltd., vacuum mixer dryer manufactured by Katsuragi Kogyo Co., Ltd., vacuum mixer dryer manufactured by Yasujima Co., Ltd., mixer, semi-pressurized knee Examples of suitable dryers include kneader-ruders, kneader-ruders, and vacuum extruders, KID dryers, roto-louver dryers, rotary dryers, and rotary kilns manufactured by Kurimoto Iron Works, Ltd., conical dryers manufactured by Kobelco Eco-Solutions Co., Ltd., electrically heated rotary kilns, gas heated rotary kilns, batch rotary kilns, desktop rotary kilns, vacuum desktop rotary kilns, and special atmosphere + vacuum rotary kilns manufactured by Takasago Industrial Co., Ltd., super rotary dryers and eco dryers manufactured by Okawara Manufacturing 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 Corporation.
The mixing device may be used alone or in combination of a plurality of types of mixing devices.

Examples of methods for adding compound (1) include adding it by using its own weight, adding it by applying pressure, and adding it using a liquid delivery 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 using a liquid delivery pump is preferred because it tends to have excellent controllability over the rate at which compound (1) is added.

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-transfer pump for adding compound (1), etc.), and piping and the like connecting each of them, materials used in the places in contact with compound (1) and/or compound (2) are not particularly limited as long as they are commonly 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-cobalt 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.

Compound (1) and compound (2) are reacted to produce compound (3) and compound (4). Compound (3) and compound (4) are known to be useful compounds as raw materials for fluorine-based polymer 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.

The method for separating compound (3) is not particularly limited as long as it is a commonly used method, but examples include a method in which compound (1) and compound (2) are reacted while compound (3) is distilled off and separated, a method in which compound (3) is distilled off and separated after the reaction between compound (1) and compound (2) is completed, and a method in which a solution containing compound (3) is made using a compound that can dissolve compound (3) but not compound (4), the compound used for dissolving the compound is removed, and compound (3) is separated. Among these, the method in which compound (3) is distilled off and separated while compound (1) and compound (2) are reacted 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.

The compound capable of dissolving the compound (3) but not the compound (4) is not particularly limited as long as it is a compound used in general boats, and examples of the compound include 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 such 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, Novec (registered trademark) series and Fluorinert (registered trademark) series manufactured by 3M Corporation, Vertrel (registered trademark) series manufactured by Chemours, Solkan (registered trademark) manufactured by Solvay, Asahiklin (registered trademark) series and Amorea (registered trademark) series manufactured by AGC Inc., 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.

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 include a method for increasing the purity by distillation, a method for reducing the content of the compound that reduces 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 reduces the purity and separates from compound (3), and a combination of these methods.

When compound (3) is distilled, the conditions are not particularly limited as long as they are generally used, and any of atmospheric distillation, pressurized distillation, and reduced pressure distillation may be used. The distillation apparatus may be a plate tower, a packed tower, or a combination of these. As the tray deck of the plate tower, any of bubble caps, sieve trays, movable valves, and fixed valves may be used. As the packing of the packed tower, any of regular packing and 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. The packing material is not particularly limited as long as it is a commonly used packing material, but examples thereof include Raschig rings, Lessing rings, Paul rings, Cross rings, Medal Packs, Toll Packs, Omni Packs, Berl Saddles, Intalox Saddles, Dixon Packings, McMahon Packings, Heli Packs, Mela Packs, Gem Packs, Techno Packs, Flexi Packs, Sulzer Packings, Good Roll Packings, Good Roll Packings, and the like. The reflux ratio and theoretical plate number can be in the commonly used range as long as they are capable of achieving 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. The number of theoretical plates is preferably 300 or less, more preferably 200 or less, and even more preferably 100 or less, since this tends to reduce the cost of the distillation apparatus and is economical. The number of theoretical plates is preferably 1 or more, more preferably 5 or more, and even more preferably 10 or more, since this tends to improve the purity of compound (3).

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 dimethyl sulfoxide, dibutyl sulfoxide, ethyl methyl sulfone, ethyl isopropyl sulfone, sulfolane, and 3-methyl sulfolane. Among these, water and an aqueous solution containing an inorganic salt are preferred because they tend to suppress contamination of compound (3).
The extract compounds may be used alone or in combination of two or more.

In the specification of this embodiment, the inorganic salt-containing aqueous solution refers to 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.

The inorganic salt compound is not particularly limited as long as it is a commonly used compound, but specific examples 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; 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, magnesium thiosulfate, and other thiosulfates; 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, dirubidium hydrogen phosphate, dicesium hydrogen phosphate; phosphorus Phosphates such as diammonium hydrogen citrate, 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, discesium hydrogen citrate, diammonium hydrogen citrate, lithium dihydrogen citrate, sodium dihydrogen citrate, citrate Examples of the tartrate salts include potassium dihydrogen citrate, rubidium dihydrogen citrate, cesium dihydrogen citrate, and ammonium dihydrogen citrate; 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; and tetraborates such as lithium tetraborate, sodium tetraborate, potassium tetraborate, rubidium tetraborate, cesium tetraborate, and ammonium tetraborate.

Among these, the following are preferred because they tend to be easily available and economical: sodium bicarbonate, potassium bicarbonate, cesium bicarbonate, ammonium bicarbonate, 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, and sodium bicarbonate, potassium bicarbonate, ammonium bicarbonate, sodium carbonate, potassium carbonate, ammonium carbonate, and hydrogen sulfate are also preferred. Sodium, 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, and 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, and sodium hydrogen carbonate, sodium carbonate, sodium hydrogen sulfate, sodium sulfate, sodium thiosulfate, sodium acetate, potassium acetate, trisodium phosphate, tripotassium phosphate, disodium hydrogen phosphate, and sodium dihydrogen phosphate are particularly preferred.

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 economic 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.

<Ratio (ζ/ε) of the mass (ζ) of the extracted compound to the mass (ε) of the 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.

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, but 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.

By stirring and mixing the compound (3) separated after the reaction of compound (1) with compound (2) with the extracted compound, the rate at which the compound with reduced purity dissolves in the extracted compound tends to improve. The stirring method is not particularly limited as long as it is a commonly used stirring method, but specifically includes 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, a device equipped with the stirring method can be used.
The stirring method and the device equipped with the stirring method may be used alone or in combination of two or more kinds.

The stirring/mixing time is not particularly limited as long as it is within a commonly used range, but since there is a tendency for the amount of compounds that reduce the purity of compound (3) to dissolve in the extracted compound 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 times 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.

Compound (3) and the extracted compound are stirred and mixed, and then allowed to stand, causing phase separation 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. By not leaving it for an excessive time, it tends to become a production method with better economic efficiency, so 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.

The temperature at which the fluorine-containing vinyl sulfonic acid fluoride (3) and the extract compound are stirred and mixed, and the temperature at which the mixture is allowed to stand and separated into phases are not particularly limited as long as they are commonly used temperatures. However, 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 superior economical aspects when adjusting the temperature industrially, the temperature is more preferably 0°C or higher, and particularly preferably 10°C or higher.

The upper limits of the temperature at which the fluorinated vinyl sulfonic 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, are not particularly limited, but since there is a tendency for dissolution of the compound (3) in the extract compound to be suppressed, the upper limits are preferably 120° C. or lower, more preferably 100° C. or lower, even more preferably 80° C. or lower, and particularly preferably 60° C. or lower.
The temperature at which the fluorine-containing vinyl sulfonyl fluoride (3) and the extraction compound are stirred and mixed, and the temperature at which they are left to stand for phase separation, do not need to be constant so long as they are within the above-mentioned ranges, and may be changed during the process.

The pressure for stirring and mixing the fluorine-containing vinylsulfonic acid fluoride (3) and the extracted compound, and the pressure for allowing to stand and phase-separate 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 the compound (3) and the extracted compound may volatilize depending on their types, it is effective to apply pressure at atmospheric pressure or higher to suppress volatilization. When the volatilized compound is liquefied and reused, the pressure may be reduced to atmospheric pressure or lower.
The pressure under which the fluorinated vinylsulfonic acid fluoride (3) and the extracted compound are stirred and mixed, and the pressure under which the mixture is left to stand for phase separation, do not need to be constant so long as they are within the above-mentioned ranges, and may be changed during the process.

The atmosphere for stirring and mixing the fluorine-containing vinylsulfonic acid fluoride (3) and the extracted compound, and the atmosphere for allowing to stand and separate the phases are not particularly limited as long as they are commonly used, 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 the 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 fluorinated vinylsulfonic acid fluoride (3) and the extracted compound, and the atmosphere for leaving them to separate into phases may be one kind alone or a combination of two or more kinds of atmospheres.

The fluorine-containing vinyl sulfonic acid fluoride (3) and the extracted compound are stirred and mixed, and then allowed to stand to separate into phases. The phase containing the extracted compound obtained may be reused to increase the purity of the separated compound (3) after the reaction of compound (1) with compound (2).

In the reaction between compound (1) and compound (2), a smaller amount of compound (2) is used than the amount of compound (1), unreacted compound (1) is left behind, and the resulting compound (3) is separated, and then compound (1) is separated from the resulting compound (4) to recover compound (1), or compound (3) and compound (1) are separated from compound (4), and compound (1) is recovered by separating compound (3) and 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 viewpoint, and because compound (2) is easier to obtain than compound (1) and tends to be more economical for producing compound (3), it is believed that a method of using a larger amount of compound (2) than compound (1), reducing the amount of unreacted compound (1), forming a mixture containing compound (2), compound (3), and compound (4), separating compound (3), and then separating compound (4) from the mixture containing compound (2) and compound (4) tends to be more economical for producing compound (3).

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 of obtaining compound (4) from a mixture containing compound (2) and compound (4) (hereinafter referred to as "dissolved compound") that has a high solubility in compound (4) and a low solubility in compound (2) is added to obtain a solution in which compound (4) is dissolved in the dissolved compound (hereinafter referred to as "fluorine-containing sulfonate solution"), removing compound (2) by filtration, and then distilling off the compound that has a high solubility in compound (4) or crystallizing compound (4) can be mentioned.

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

Specific examples of dissolving compounds include 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 ether compounds such as acetone, methyl acetone, ethyl methyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, methyl hexyl ketone, diethyl ketone, ethyl butyl ketone, dipropyl ketone, diisobutyl ketone, and cyclohexanone; ketone 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; ester compounds such as dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, ethyl methyl carbonate, fluoromethyl methyl carbonate, difluoromethyl methyl carbonate, ester, 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-dioxolane-2-one, 4,5-difluoro-4,5-dimethyl-1,3-dioxolane-2-one, vinylene carbonate, vinyl ethylene carbonate, methyl vinylene carbonate, ethyl vinylene carbonate, and other carbonate compounds; acetonitrile, propionitrile, butyronitrile, isobutyronitrile, 2-methylbutyronitrile, cyclohexanecarbonitrile, benzonitrile, adiponitrile, fluoroacetonitrile, difluoroacetonitrile, 2-fluorobenzonitrile, 2,4,5-trifluorobenzonitrile, o-(trifluoromethyl)benzonitrile, and pentafluorobenzonitrile are more preferred, and examples of such nitrile compounds include 2-fluorobenzonitrile, 2,4,5-trifluorobenzonitrile, o-(trifluoromethyl)benzonitrile, and pentafluorobenzonitrile.

Among the 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. Compound (4) tends to have high solubility, so 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. Tetrahydrofuran, tetrahydropyran, methyl tert-butyl ether, 1,4-dioxane, and 1,2-dimethoxyethane are more preferred because they are easy to obtain or produce and tend to be economical.

Among the ketone compounds, acetone, ethyl methyl ketone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, and cyclohexanone are preferred because compound (4) tends to have high solubility, and acetone, ethyl methyl ketone, methyl propyl ketone, and methyl isobutyl ketone are more preferred. Acetone, ethyl methyl ketone, and methyl isobutyl ketone are even more preferred because they are easily available and tend to be economical.

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 economical.

Among the 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 tend to be easily available and economical, and dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, ethyl methyl carbonate, ethylene carbonate, and propylene carbonate are more preferred because they tend to have high solubility of compound (4). Dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, and propylene carbonate are even more preferred, and dimethyl carbonate and ethylene carbonate are particularly preferred.

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

<Ratio (δ/γ) of mass of dissolved compound (δ) to 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 excessive dissolved compound is suppressed and the economical efficiency when producing compound (4) tends to be excellent.

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, an apparatus equipped with the above stirring method can be used.
The stirring method and the device equipped with the stirring method may be used alone or in combination of two or more kinds.

The time for stirring the reaction residue and the dissolving compound is not particularly limited as long as it is within a commonly used range, 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 avoiding excessive stirring and mixing times 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.

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 the 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 the dissolved compound may volatilize depending on the type, it tends to be possible to suppress volatilization and to suppress precipitation of the compound (4), so 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 the reaction residue and the dissolved compound are stirred does not need to be constant so long as it is within the above range, and may be changed during the process.

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 does not need to be constant so long as it is within the above range, and may be changed during the process.

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 they tend 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.

The method for separating compound (2) that is 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 collection of the supernatant. 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).

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, but can be broadly classified into, for example, horizontal filter plate type devices, multi-chamber horizontal filter plate type devices, ceramic membrane type devices, cylindrical multi-chamber type devices, cylindrical single-chamber type devices, horizontal traveling type devices, siphon type devices, basket type devices, separation plate type devices, decanter type devices, candle filters, etc.
The filtration device may be used alone or in combination of two or more types.

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 devices such as scraper discharge filters, bag filters, candle filters, Druck filters, and sintered media filters; reduced pressure filtration devices 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 devices such as belt presses, screw presses, tube presses, and Mars presses; magnetic filtration devices such as ring-type magnetic separators and cylindrical magnetic separators; and electrostatic filtration devices such as rotary electrostatic separators.
The filtration device used for filtration and separation is equipped with a filtration layer that collects solids and allows liquids to pass through, and in this application, the filtration layer is referred to as a filter medium.

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, but examples include a decanter, a static screening machine, a moving 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, a centrifugal separator, and the like.

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).

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 & 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, fired products, and flux fired 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 sulfonic acid group-containing monomers.
The filter aids may be used alone or in combination of two or more.

The transmittance (Darcy) of the filter aid is not particularly limited as long as it is within the range of transmittances (Darcy) commonly used, but is preferably 0.01 to 30. Since the amount of compound (2) remaining is 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) is short and the amount of compound (2) remaining is small, it is preferably 22 or less, more preferably 2 or less, and even more preferably 0.25 or less.

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

The amount of filter aid used here refers to the total amount of filter aid used in filtration and separation. For example, when the precoat method and the body feed method are used in combination, it refers to the total amount of filter aid used in the two methods. Also, when the filter aid layer formed in filtration and separation is partially removed and the remaining filter aid layer is reused, it refers to the total amount of the filter aid supplied and the remaining filter aid layer.

The method of using the filter aid is not particularly limited as long as it is a commonly used method, but examples include the precoat method in which the filter aid is attached to a filter medium to form a layer of the filter aid and then filtration is performed, and the body feed method in which the filter aid is added to the liquid to be filtered and then filtered. These methods may be used alone or in combination of multiple types. A combined use of the precoat method and the body feed method is preferred, as this tends to suppress clogging of the filter medium, tends to suppress clogging of the surface of the filter aid layer, and tends to extend the period during which operation can be performed on an industrial scale.

The filter medium used for filtration and separation is not particularly limited as long as it is a commonly used filter medium, but examples include filter cloth, metal filters, sintered metal filters, metal fiber/powder laminated types, etc. These may be used alone or in combination of multiple types. When using filter cloth, it can also 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.

The material of the filter cloth is not particularly limited as long as it is a commonly used material, but examples 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 sulfonic acid group-containing monomers. 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.

The material of the metallic filter medium is not particularly limited as long as it is a commonly used material, but 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. 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.

The air permeability of the filter medium is not particularly limited as long as it is in a general range, but is preferably 0.01 to 200 cm ³ /cm ² ·s. Since the filtration time of the compound (2) tends to be shorter, it is preferably 0.05 cm ³ /cm ² ·s or more, and more preferably 0.1 cm ³ /cm ² ·s or more. Since the residual amount of the compound (2) tends to be smaller, and when a filter aid is used, the permeation amount of the filter aid tends to be smaller, it is more preferably 100 cm ³ /cm ² ·s or less, more preferably 50 cm ³ /cm ² ·s or less, and even more preferably 20 cm ³ /cm ² ·s or less.

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, since 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, since the amount of volatile components generated from the liquid to be filtered tends to decrease and changes in the state of the precipitate tend to be suppressed. The temperature is further preferably 70°C or lower, and particularly preferably 60°C or lower, since the amount of compound (2) dissolved in the dissolving compound tends to decrease and the remaining amount of compound (2) tends to be smaller.
The temperature during filtration and separation may be constant or may be varied.

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

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 commonly used pressures, and may be constant or may be changed.

When the filtration method is gravity filtration, the upstream pressure is normal pressure, and filtration and separation are achieved by the pressure generated by the weight of the liquid being filtered.

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 filtration devices tend to be generally easily available, so 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 it is desired to shorten the filtration time of compound (2).
The upstream and downstream pressures in pressure filtration may be constant or may be varied.

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, etc., 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 suppressed 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.

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.

The supply amount of the liquid to be filtered is not particularly limited as long as it is within the range of a general supply amount, but is preferably 10 to 10,000 kg/m ² ·hr. Since the recovery amount per hour of compound (4) is improved and the economy when purifying compound (4) tends to improve, it is more preferable that it is 50 kg/m ² ·hr or more, and even more preferable that it is 80 kg/m ² ·hr or more. 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 residual amount of compound (2) will increase. From the above, since there is a tendency to reduce the residual amount of compound (2), it is more preferable that it is 5000 kg/m ² ·hr or less, and even more preferable that it is 1000 kg/m ² ·hr or less.
The supply of liquid to be filtered may be constant or may vary.

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 they tend to be a more economical production method.
The filtration atmosphere may be one type alone or a combination of a plurality of types of atmospheres.

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

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.

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 apparatus used. However, since there is a tendency for the size of the pump for reducing the pressure to be reduced and for the airtightness of the apparatus used to be increased, the structure of the filtration apparatus to be prevented from becoming complicated, the lower limit 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.

The atmosphere in which the dissolved compounds are distilled off and the compound (4) is separated is not particularly limited as long as it is a commonly used atmosphere, and usually, an air atmosphere, a nitrogen atmosphere, an argon atmosphere, etc. are used. Among these, a nitrogen atmosphere and an argon atmosphere are preferred because they tend to produce the compound (4) more safely. In addition, a 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.

The apparatus used in separating the dissolved compound 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 rebo-cone, 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.

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.

The dissolved compound obtained when the dissolved compound is distilled off and compound (4) is separated can be reused in a method for separating compound (4) from a reaction residue. 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.

By adding water to the fluorine-containing sulfonate-containing filtrate or by 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 aqueous solution containing fluorine-containing sulfonate may be prepared by adding water once and distilling off the dissolved compounds, or the aqueous solution containing fluorine-containing sulfonate may be prepared by repeating the addition and distillation of water multiple times. Since the total mass of water used to reduce the dissolved compounds contained in the aqueous solution containing fluorine-containing sulfonate tends to be reduced, a method in which water is added and distilled off multiple times is more preferable. 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, which tends to reduce the total mass of water used, and is therefore a preferred method.

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 solution of fluorinated sulfonic acid is low, it is more preferable to distill off the dissolved compound at a small ratio of κ/ι and then add water to adjust the concentration of compound (4) in the desired aqueous solution of fluorinated sulfonic acid, 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 the vacuum pump when reducing the pressure.

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 added after distillation of the dissolved compounds are not particularly limited as long as they are commonly used temperatures, but since there is a tendency to be able to suppress 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 preferable to be 0 ° C. or higher, and particularly preferable to be 10 ° C. or higher. The upper limit of 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 added after distillation of the dissolved compounds is not particularly limited, but since there is a case where water and the dissolved compounds may volatilize depending on the type, it is possible to suppress volatilization and to suppress precipitation of compound (4), so 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.

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 do not need to be constant so long as they are within the above-mentioned ranges and may be changed during the process.

The atmosphere in which water is added to the filtrate containing fluorine-containing sulfonate, the atmosphere in which the filtrate containing fluorine-containing sulfonate is added to water, and the atmosphere in which water is further added 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 distilling off the dissolved compounds may be one kind alone or a combination of two or more kinds of atmospheres may be used.

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 when 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.

The pressure when distilling off the dissolved compound from the mixture of the fluorine-containing sulfonate-containing filtrate and water is not particularly limited as long as it is within the range of normal use, and may be any of pressurized, normal pressure, and reduced pressure, but is usually performed at normal pressure or reduced pressure.When distilling off the dissolved compound at reduced pressure, the temperature during distillation can be lower than that when distilling off at normal pressure, and depending on the type of compound (4), the deterioration of compound (4) tends to be suppressed, so this is a preferred method.When distilling off the dissolved compound 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 when the dissolved compounds are distilled off from the mixture of the fluorine-containing sulfonate-containing filtrate and water does not have to be constant so long as it is within the above range, and may be changed during the process.

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 for 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.

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

The dissolved compounds obtained by distilling off the dissolved compounds from the mixture of the 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 compounds.

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 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 the 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 the fluorine-containing salt-containing aqueous solution.

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

The following are examples that specifically explain this embodiment. The present invention is not limited to the following examples as long as they do not exceed the gist of the invention.

The analytical methods used in the examples and comparative examples are as follows:

<Nuclear Magnetic Resonance Analysis (NMR): Molecular Structure Analysis by ¹⁹ F-NMR>
The products obtained in the examples and comparative examples were subjected to molecular structure analysis using ¹⁹ F-NMR under the following measurement conditions.
[Measurement conditions]
Measurement device: JNM-ECZ400S nuclear magnetic resonance device (manufactured by JEOL Ltd.)
Observed nucleus: ^19F
Solvent: deuterated chloroform Standard substance: tetramethylsilane (0.00 ppm)
Observation frequency: 400MHz ( ^1H )
Pulse width: 6.5 μsec Waiting time: 2 sec Number of integrations: 16

<Nuclear Magnetic Resonance Analysis (NMR): Molecular Structure Analysis by ¹ H-NMR>
The products obtained in the examples and comparative examples were subjected to molecular structure analysis using ¹ H-NMR under the following measurement conditions.
[Measurement conditions]
Measurement device: JNM-ECZ400S nuclear magnetic resonance device (manufactured by JEOL Ltd.)
Observed nucleus: ¹ H
Solvent: deuterated chloroform Standard substance: tetramethylsilane (0.00 ppm)
Observation frequency: 400MHz ( ^1H )
Pulse width: 7.3 μsec Waiting time: 5 sec Number of integrations: 8

<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: 30 mL/min
Injection volume: 1 μL
Split ratio: 30
Vaporization chamber temperature: 200°C
Column temperature program: 40°C for 10 min, then heated at 20°C/min, then held at 280°C for 10 min. Detection: FID, 200°C

The raw materials used in the examples and comparative examples are listed below.

[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.
CF ₂ =CFOCF ₂ CF ₂ SO ₃ Na (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.
(CF ₂ = CFOCF ₂ CF ₂ SO ₂ ) ₂ O (8)
The obtained compound (8) was distilled to obtain a purified compound (8). The obtained 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} )

(Alkali Metal Fluoride (2) (Compound (2))
・Potassium fluoride (Fujifilm Wako Pure Chemical Industries, special grade reagent)
Rubidium fluoride (Aldrich, purity 99.8%)
・Cesium fluoride (Fujifilm Wako Pure Chemical Industries, special grade reagent)

(others)
- Ethanol (Fujifilm Wako Pure Chemical Industries, special grade reagent)
- Hexafluorobenzene (Tokyo Chemical Industry Co., Ltd.)
- Benzotrifluoride (Tokyo Chemical Industry Co., Ltd.)
・Purified water (manufactured by 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 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent)
- Dimethyl carbonate (Fujifilm Wako Pure Chemical Industries, special grade reagent)
1,2-Dimethoxyethane (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Wako special grade)
Sodium bicarbonate aqueous solution: This solution was 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.

[Example 1]
Potassium fluoride (56.8 g, 0.977 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 the flask was 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. In the nitrogen atmosphere space, the compound (8) produced in Production Example 1 was placed in the dropping funnel, the dropping funnel was removed from the nitrogen atmosphere space, and the dropping funnel was attached to the flask while flowing nitrogen. A refrigerant at -5°C was passed through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath set at 110°C, the three-one motor was rotated at 120 rpm, and the flask was stirred for 10 minutes, after which the pressure in the flask was reduced to 70 kPaA. The compound (8) produced in Production Example 1 was gradually dripped from the dropping funnel. It took 62 minutes to complete the dripping. After the reaction was completed, the mass of the dropping funnel before and after the dripping was measured, and it was found that 342.5 g of the compound (8) produced in Production Example 1 (335.7 g (0.624 mol) of the compound (8) and 6.85 g (0.025 mol) of the compound (9)) was dripped. When the compound (8) produced in Production Example 1 was dripped, 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, it was determined that the reaction was completed, the flask was removed from the oil bath, and the flask was placed in a nitrogen atmosphere, 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 172.8 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ 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: 166.9 g, product mass: 0.596 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 the fluorinated vinyl sulfonic acid fluoride (10) was calculated by the following formula (1).
Production rate (%) of fluorine-containing vinyl sulfonic acid fluoride (10)=amount of substance of fluorine-containing vinyl sulfonic acid fluoride (10)/amount of substance of compound (8)×100 (1)
For example, the production rate (%) of the fluorine-containing vinylsulfonic acid fluoride (10) in this example is 0.596 (mol)/0.624 (mol)×100=95.6.
In this embodiment, β/α was 1.6.
CF ₂ =CFOCF ₂ CF ₂ SO ₂ F (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 217.4 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was confirmed that fluorine-containing vinyl sulfonate (11) represented by the following general formula (11) was produced (amount produced: 198.1 g, product mass: 0.626 mol). In the analysis, the amount of fluorine-containing vinyl sulfonate (11) produced and the like were calculated from the mass of 2,2,2-trifluoroethanol, the integral values of _CF3 of 2,2,2-trifluoroethanol, and _CF2 of fluorine-containing vinyl sulfonate (11).
CF ₂ =CFOCF ₂ CF ₂ SO ₃ K (11)
¹⁹ F-NMR: δ (ppm) -84.83 (2F), -113.83 (1F), -118.30 (2F), -122.05 (1F), -135.70 (1F)
In this example, the dropwise addition rate (hereinafter referred to as "addition rate") of compound (8) produced in Production Example 1 was 5.5 g/min. The addition rate was calculated from the mass (342.5 g) of compound (8) produced in Production Example 1 used and the dropwise addition time (62 min) as 342.5 (g)/62 (min)=5.5 (g/min). The same calculation was performed in the following examples.
In this example, the dropwise addition rate of compound (8) produced in Production Example 1 relative to compound (2) (hereinafter referred to as "mass ratio addition rate") was 5.8 g/min/g. The mass ratio addition rate was calculated as 342.5 (g)/62 (min)/56.8 (g) = 5.8 (g/min/g) from the mass (342.5 g) of compound (8) produced in Production Example 1 used, the dropwise addition time (62 min), and the mass (56.8 g) of compound (2). Similar calculations were performed in the following examples.

[Example 2]
Potassium fluoride (55.2 g, 0.950 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 the flask was 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. In the nitrogen atmosphere space, the compound (8) produced in Production Example 1 was placed in the dropping funnel, the dropping funnel was removed from the nitrogen atmosphere space, and the dropping funnel was attached to the flask while flowing nitrogen. A refrigerant at −5° C. was passed through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath set at 130° C., the three-one motor was rotated at 120 rpm, and the flask was stirred for 10 minutes, after which the pressure in the flask was reduced to 80 kPaA. The compound (8) produced in Production Example 1 was gradually dripped from the dropping funnel. It took 38 minutes to complete the dripping. After the reaction was completed, the mass of the dropping funnel before and after the dripping was measured, and it was found that 334.1 g of the compound (8) produced in Production Example 1 (327.4 g (0.608 mol) of the compound (8) and 6.68 g (0.024 mol) of the compound (9)) was dripped. When the compound (8) produced in Production Example 1 was dripped, 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, it was determined that the reaction was completed, the flask was removed from the oil bath, and the flask was placed in a nitrogen atmosphere, 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 166.6 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was found that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 160.7 g, product mass: 0.574 mol, production rate: 94.3%).
In this embodiment, β/α was 1.6.
The residue remaining in the flask was collected and its mass was measured, which was 213.1 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was also confirmed that fluorine-containing vinyl sulfonate (11) was produced (amount produced: 194.5 g, product mass: 0.615 mol).
In this example, the addition rate was 8.8 g/min, and the mass specific addition rate was 9.6 g/min/g.

[Example 3]
Potassium fluoride (59.1 g, 1.02 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 the flask was 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. In the nitrogen atmosphere space, the compound (8) produced in Production Example 1 was placed in the dropping funnel, the dropping funnel was removed from the nitrogen atmosphere space, and the dropping funnel was attached to the flask while flowing nitrogen. A refrigerant at -5°C was passed through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath set at 150°C, the three-one motor was rotated at 120 rpm, and the flask was stirred for 10 minutes, after which the pressure in the flask was reduced to 90 kPaA. The compound (8) produced in Production Example 1 was gradually dripped from the dropping funnel. It took 19 minutes to complete the dripping. After the reaction was completed, the mass of the dropping funnel before and after the dripping was measured, and it was found that 356.2 g of the compound (8) produced in Production Example 1 (349.1 g (0.649 mol) of the compound (8) and 7.12 g (0.026 mol) of the compound (9)) was dripped. When the compound (8) produced in Production Example 1 was dripped, 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, it was determined that the reaction was completed, the flask was removed from the oil bath, and the flask was placed in a nitrogen atmosphere, 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 177.9 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was found that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 164.1 g, product mass: 0.586 mol, production rate: 90.3%).
In this embodiment, β/α was 1.6.
The residue remaining in the flask was collected and its mass was measured, which was 229.5 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was also confirmed that fluorine-containing vinyl sulfonate (11) was produced (amount produced: 209.0 g, product mass: 0.661 mol).
In this example, the addition rate was 18.7 g/min, and the mass specific addition rate was 19.0 g/min/g.

[Example 4]
Potassium fluoride (17.4 g, 0.300 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 the flask was 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. In the nitrogen atmosphere space, the compound (8) produced in Production Example 1 was placed in the dropping funnel, the dropping funnel was removed from the nitrogen atmosphere space, and the dropping funnel was attached to the flask while flowing nitrogen. A refrigerant at -5°C was passed through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath set at 90°C, the three-one motor was rotated at 120 rpm, and the flask was stirred for 10 minutes, after which the pressure in the flask was reduced to 60 kPaA. The compound (8) produced in Production Example 1 was gradually dripped from the dropping funnel. It took 175 minutes to complete the dripping. After the reaction was completed, the mass of the dropping funnel before and after the dripping was measured, and it was found that 105.1 g of the compound (8) produced in Production Example 1 (103.0 g (0.191 mol) of the compound (8) and 2.10 g (0.008 mol) of the compound (9)) was dripped. When the compound (8) produced in Production Example 1 was dripped, 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, it was determined that the reaction was completed, the flask was removed from the oil bath, and the flask was placed in a nitrogen atmosphere, 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 53.6 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was found that fluorine-containing vinyl sulfonyl fluoride (10) was produced (amount produced: 51.1 g, product mass: 0.183 mol, production rate: 95.4%).
In this embodiment, β/α was 1.6.
The residue remaining in the flask was collected and its mass was measured, which was 66.6 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was also confirmed that fluorine-containing vinyl sulfonate (11) was produced (amount produced: 60.6 g, product mass: 0.192 mol).
In this example, the addition rate was 0.60 g/min, and the mass specific addition rate was 2.1 g/min/g.

[Example 5]
Potassium fluoride (39.0 g, 0.672 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 the flask was 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. In the nitrogen atmosphere space, the compound (8) produced in Production Example 1 was placed in the dropping funnel, the dropping funnel was removed from the nitrogen atmosphere space, and the dropping funnel was attached to the flask while flowing nitrogen. A refrigerant at −5° C. was passed through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath set at 110° C., the three-one motor was rotated at 120 rpm, and the flask was stirred for 10 minutes, after which the pressure in the flask was reduced to 70 kPaA. The compound (8) produced in Production Example 1 was gradually dripped from the dropping funnel. It took 112 minutes to complete the dripping. After the reaction was completed, the mass of the dropping funnel before and after the dripping was measured, and it was found that 322.6 g of the compound (8) produced in Production Example 1 (316.1 g (0.587 mol) of the compound (8) and 6.45 g (0.023 mol) of the compound (9)) was dripped. When the compound (8) produced in Production Example 1 was dripped, 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, it was determined that the reaction was completed, the flask was removed from the oil bath, and the flask was placed in a nitrogen atmosphere, 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 165.9 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was found that fluorine-containing vinyl sulfonyl fluoride (10) was produced (amount produced: 152.5 g, product mass: 0.544 mol, production rate: 92.7%).
In this embodiment, β/α was 1.1.
The residue remaining in the flask was collected and its mass was measured, which was 189.3 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was also confirmed that fluorine-containing vinyl sulfonate (11) was produced (amount produced: 184.7 g, product mass: 0.584 mol).
In this example, the addition rate was 2.9 g/min, and the mass specific addition rate was 4.4 g/min/g.

[Example 6]
Potassium fluoride (121.8 g, 2.10 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 the flask was 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. In the nitrogen atmosphere space, the compound (8) produced in Production Example 1 was placed in the dropping funnel, the dropping funnel was removed from the nitrogen atmosphere space, and the dropping funnel was attached to the flask while flowing nitrogen. A refrigerant at -5°C was passed through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath set at 110°C, the three-one motor was rotated at 120 rpm, and the flask was stirred for 10 minutes, after which the pressure in the flask was reduced to 70 kPaA. The compound (8) produced in Production Example 1 was gradually dripped from the dropping funnel. It took 42 minutes to complete the dripping. After the reaction was completed, the mass of the dropping funnel before and after the dripping was measured, and it was found that 123.1 g of the compound (8) produced in Production Example 1 (120.6 g (0.224 mol) of the compound (8) and 2.46 g (0.009 mol) of the compound (9)) was dripped. When the compound (8) produced in Production Example 1 was dripped, 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, it was determined that the reaction was completed, the flask was removed from the oil bath, and the flask was placed in a nitrogen atmosphere, 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 61.8 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was found that fluorine-containing vinyl sulfonyl fluoride (10) was produced (amount produced: 60.0 g, product mass: 0.214 mol, production rate: 95.6%).
In this embodiment, β/α was 9.4.
The residue remaining in the flask was collected and its mass was measured, which was 179.2 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was also confirmed that fluorine-containing vinyl sulfonate (11) was produced (amount produced: 71.9 g, product mass: 0.227 mol).
In this example, the addition rate was 2.9 g/min, and the mass specific addition rate was 1.4 g/min/g.

[Example 7]
Rubidium fluoride (31.7 g, 0.303 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 the flask was 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. In the nitrogen atmosphere space, the compound (8) produced in Production Example 1 was placed in the dropping funnel, the dropping funnel was removed from the nitrogen atmosphere space, and the dropping funnel was attached to the flask while flowing nitrogen. A refrigerant at −5° C. was passed through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath set at 80° C., the three-one motor was rotated at 120 rpm, and the flask was stirred for 10 minutes, after which the pressure in the flask was reduced to 70 kPaA. The compound (8) produced in Production Example 1 was gradually dropped from the dropping funnel. It took 57 minutes to complete the dropping. After the reaction was completed, the mass of the dropping funnel before and after the dropping was measured, and it was found that 95.7 g of the compound (8) produced in Production Example 1 (93.8 g (0.174 mol) of the compound (8) and 1.91 g (0.007 mol) of the compound (9)) was dropped. When the compound (8) produced in Production Example 1 was dropped, the liquid gradually started 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, it was determined that the reaction was completed, the flask was removed from the oil bath, and the flask was placed in a nitrogen atmosphere, 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 46.4 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was found that fluorine-containing vinyl sulfonyl fluoride (10) was produced (amount produced: 45.8 g, product mass: 0.163 mol, production rate: 93.8%).
In this embodiment, β/α was 1.7.
The residue remaining in the flask was collected and its mass was measured, which was 76.5 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was also confirmed that fluorine-containing vinyl sulfonate (4) was produced (amount produced: 63.8 g, product mass: 0.176 mol).
In this example, the addition rate was 1.7 g/min, and the mass specific addition rate was 3.2 g/min/g.

[Example 8]
Cesium fluoride (52.3 g, 0.344 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 the flask was 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. In the nitrogen atmosphere space, the compound (8) produced in Production Example 1 was placed in a dropping funnel, the dropping funnel was removed from the nitrogen atmosphere space, and the dropping funnel was attached to the flask while flowing nitrogen. A refrigerant at −5° C. was passed through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath set at 60° C., the three-one motor was rotated at 120 rpm, and stirring was performed for 10 minutes, after which the pressure in the flask was reduced to 70 kPaA. The compound (8) produced in Production Example 1 was gradually dripped from the dropping funnel. It took 65 minutes to complete the dripping. After the reaction was completed, the mass of the dropping funnel before and after the dripping was measured, and it was found that 112.1 g of the compound (8) produced in Production Example 1 (109.9 g (0.204 mol) of the compound (8) and 2.24 g (0.008 mol) of the compound (9)) was dripped. When the compound (8) produced in Production Example 1 was dripped, 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, it was determined that the reaction was completed, the flask was removed from the oil bath, and the flask was placed in a nitrogen atmosphere, 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 54.4 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was found that fluorine-containing vinylsulfonic acid fluoride (10) was produced (amount produced: 53.8 g, product mass: 0.192 mol, production rate: 94.1%).
In this embodiment, β/α was 1.7.
The residue remaining in the flask was collected and its mass was measured, which was 104.2 g. For analysis, the residue (0.20 g), purified water (1.00 g), and 2,2,2-trifluoroethanol (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, it was also confirmed that fluorine-containing vinyl sulfonate (4) was produced (amount produced: 84.3 g, product mass: 0.206 mol).
In this example, the addition rate was 1.7 g/min, and the mass specific addition rate was 2.0 g/min/g.

[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. 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. Since the liquid did not start to distill off even after 1 hour, the pressure was gradually lowered, and the liquid started to distill off, eventually reaching 2 kPaA. When the liquid was no longer distilled off 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 279.3 g. For analysis, the fraction (0.30 g), hexafluorobenzene (1.30 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the analysis, fluorine-containing vinyl sulfonyl fluoride (10) was produced (amount produced: 40.2 g, product mass: 0.143 mol, production rate: 24.3%).
In this embodiment, β/α was 1.6.

[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. 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. When the liquid started to be distilled off and the rate of the liquid distilled off to the receiver reached 2 drops/min, the pressure was gradually reduced to 2 kPaA. When the liquid was no longer distilled off to the receiver for more than 2 minutes, the reaction was judged to be complete, the flask was removed from the oil bath, the atmosphere was replaced with nitrogen, 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 and analyzed by ¹⁹ F-NMR. As a result of the analysis, fluorine-containing vinyl sulfonyl fluoride (10) was produced (amount produced: 53.9 g, product mass: 0.192 mol, production rate: 62.7%).
In this embodiment, β/α was 1.6.

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 fluorine-containing vinylsulfonic anhydride (1) to alkali metal fluoride (2) under heating. It was also shown that fluorine-containing vinylsulfonate (4) can be obtained.

[Example 9]
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, 39.2 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 equipped with a flask at the outlet (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as the filter paper), 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 Rikakikai Co., Ltd.), and further vacuum-dried in a vacuum dryer (AVO-250V, manufactured by AS ONE Corporation) 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 analyzed by ¹⁹ F-NMR. As a result of analysis, it was confirmed that 9.11 g (28.8 mmol) of the fluorinated vinyl sulfonate (11) was obtained.
In this embodiment, γ/δ was 3.9.

[Example 10]
9.90 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1 was placed in a flask containing a stirrer, and 94.7 g of butyl acetate was added and stirred for 30 minutes. The obtained solution was placed in a tank-attached stainless steel holder equipped with a flask at the outlet (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as the filter paper), pressurized to 0.2 MPaG with nitrogen, and filtered. The filtrate obtained in the flask was distilled to remove volatile components using a rotary evaporator (N-1300V, manufactured by Tokyo Rikakikai Co., Ltd.), and further vacuum-dried in a vacuum dryer (AVO-250V, manufactured by AS ONE Corporation) 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 analyzed by ¹⁹ F-NMR. As a result of analysis, it was confirmed that 8.91 g (28.2 mmol) of the fluorinated vinyl sulfonate (11) was obtained.
In this embodiment, γ/δ was 9.6.

[Example 11]
10.2 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1 was placed in a flask containing a stirrer, and 86.5 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 equipped with a flask at the outlet (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as the filter paper), pressurized to 0.2 MPaG with nitrogen, and filtered. The filtrate obtained in the flask was distilled to remove 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 Corporation) 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 analyzed by ¹⁹ F-NMR. As a result of analysis, it was confirmed that 9.16 g (29.0 mmol) of the fluorinated vinyl sulfonate (11) was obtained.
In this embodiment, γ/δ was 8.5.

[Example 12]
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, 113.8 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 equipped with a flask at the outlet (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as the filter paper), pressurized to 0.2 MPaG with nitrogen, and filtered. The filtrate obtained in the flask was distilled to remove volatile components using a rotary evaporator (N-1300V, manufactured by Tokyo Rikakikai Co., Ltd.), and further vacuum-dried in a vacuum dryer (AVO-250V, manufactured by AS ONE Corporation) 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 analyzed by ¹⁹ F-NMR. As a result of analysis, it was confirmed that 45.8 g (0.145 mol) of the fluorinated vinyl sulfonate (11) was obtained.
In this embodiment, γ/δ was 2.2.
The volatile components distilled off by the rotary evaporator were analyzed by ¹ H-NMR, and it was confirmed that dimethyl carbonate was the main component. 30.0 g of the volatile components mainly composed of dimethyl carbonate were mixed with 10.1 g of the residue containing the fluorinated 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 analyzed by ¹⁹ F-NMR, and it was confirmed that the fluorinated 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 5.11 g of dried residue. The dried residue 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 equipped with a receiver, 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. In a space with a nitrogen atmosphere, the compound (8) produced in Production Example 1 was placed in a dropping funnel, the dropping funnel was removed from the space with a nitrogen atmosphere, and the dropping funnel was attached to the flask while flowing nitrogen. A refrigerant at -5°C was passed through the Liebig condenser, and the receiver attached to the Liebig condenser was cooled with ethanol cooled with dry ice. The flask was placed in an oil bath set at 110°C, and the three-one motor was rotated at 120 rpm to stir for 10 minutes, after which the pressure in the flask was reduced to 70 kPaA. Compound (8) produced in Production Example 1 was gradually dripped from the dropping funnel. It took 10 minutes to complete the dripping. After the reaction was completed, the mass of the dropping funnel before and after the dripping was measured, and it was found that 24.0 g of 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)) had been dripped. When compound (8) produced in Production Example 1 was dripped, 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 to 2 kPaA. When the liquid distilled into the receiver did not come out for more than 2 minutes, the reaction was judged to be over, 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 condenser 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 and analyzed by ¹⁹ F-NMR. As a result of the analysis, fluorine-containing vinyl sulfonyl fluoride (10) was produced (amount produced: 11.3 g, product mass: 40.3 mmol, production rate: 92.2%).
In this example, the addition rate was 2.4 g/min, and the mass specific addition rate was 33.5 g/min/g.

[Example 13]
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, 14.0 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 equipped with a flask at the outlet (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as the filter paper), 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 Rika Kiki Co., Ltd.), and further vacuum-dried in a vacuum dryer (AVO-250V, manufactured by AS ONE Corporation) 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 analyzed by ¹⁹ F-NMR. As a result of analysis, it was confirmed that 9.20 g (29.1 mmol) of the fluorinated vinyl sulfonate (11) was obtained.
In this embodiment, γ/δ was 1.4.

[Example 14]
52.0 g of the residue containing the fluorine-containing vinyl sulfonate (11) obtained in Example 1 was placed in a flask containing a stirrer, 110.6 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 equipped with a flask at the outlet (KST-47, manufactured by Advantec Toyo Co., Ltd.; TR G940B2K, manufactured by Nakao Filter Kogyo Co., Ltd., was used as the filter paper), pressurized to 0.2 MPaG with nitrogen, and filtered. 105.0 g of the filtrate obtained in the flask was transferred to another flask, 58.5 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 92.1 g). 58.5 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 90.5 g). 58.5 g of purified water was added to the flask, and volatile components were distilled off using a rotary evaporator (Tokyo Rikakiki Co., Ltd., N-1300V) (the amount of the flask contents was 90.0 g). For analysis, the obtained flask contents (1.00 g) were mixed with 2,2,2-trifluoroethanol (0.10 g) and analyzed by ¹⁹ F-NMR and ¹ H-NMR. As a result of the ¹⁹ F-NMR analysis, it was confirmed that the flask contents contained 31.5 g of fluorine-containing vinyl sulfonate (11). Furthermore, as a result of the ¹ H-NMR analysis, dimethyl carbonate was not observed. From this, it was confirmed that the flask contents were an aqueous solution of fluorine-containing vinyl sulfonate (11).
In this example, κ/ι was 1.7.
When all the volatile components distilled off by the evaporator were collected, the mixture was separated into two phases. Analysis of each phase by ¹ 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 (96.4 g) and a phase mainly composed of water (131.2 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.
12.8 g of the obtained phase mainly composed of dimethyl carbonate was mixed with 6.00 g of the residue containing the fluorinated 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 analyzed by ^19F -NMR, and it was confirmed that the fluorinated vinyl sulfonate (11) was obtained.
The obtained phase (83.6 g) mainly composed of dimethyl carbonate was placed in a flask of a distillation apparatus, and volatile components were distilled off (the amount of the flask contents was 67.2 g). The water 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 water content was 1.0 mass%, and a phase mainly composed of dimethyl carbonate with a reduced water content was prepared. 20.2 g of the phase mainly composed of dimethyl carbonate with a reduced water content was mixed with 9.50 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, and the mixture was vacuum-dried to obtain a solid. The obtained solid was analyzed by ¹⁹ F-NMR, and it was confirmed that the fluorine-containing vinyl sulfonate (11) was obtained.
49.7 g of an aqueous solution of the fluorinated vinyl sulfonate (11) (containing 17.4 g (55.0 mmol) of the fluorinated vinyl sulfonate (11)) was placed in a separable flask, and sulfuric acid (special grade reagent, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) (10.8 g) was gradually added with stirring. Subsequently, cyclopentyl methyl ether (special grade reagent, manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) (34.8 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 and analyzed by ¹⁹ F-NMR, and it was confirmed that compound (9) had been obtained.

[Example 15]
39.8 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. 1.92 g was separated as an initial stream, and then 34.6 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 sulfonic acid fluoride (10) was 99.9%.

[Example 16]
39.0 g of the fluorine-containing vinyl sulfonic acid fluoride (10) obtained in Example 1 and 19.5 g of purified water were placed in a flask containing a stirrer, stirred for 30 minutes, and placed in a separatory funnel and allowed to stand for 30 minutes to obtain an upper phase (19.8 g) and a lower phase (38.1 g). For analysis, the obtained lower phase (0.30 g), 1,2-dimethoxyethane (1.00 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the ¹⁹ F-NMR analysis, it was confirmed that the separated lower phase contained 37.2 g of fluorine-containing vinyl sulfonic acid fluoride (10).
In this embodiment, 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. 3.05 g was separated as an initial stream, and then 32.0 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 (10.1 g) and 9.90 g of the fluorine-containing vinyl sulfonic acid fluoride (10) obtained in Example 1 were placed in a flask containing 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 (9.72 g). The obtained lower phase (0.30 g), 1,2-dimethoxyethane (1.00 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the ¹⁹ F-NMR analysis, it was confirmed that the separated lower phase contained 9.45 g of the fluorine-containing vinyl sulfonic acid fluoride (10).

[Example 17]
41.2 g of the fluorine-containing vinyl sulfonic acid fluoride (10) obtained in Example 1 and 41.2 g of an aqueous sodium hydrogen carbonate solution were placed in a flask containing a stirrer, stirred for 30 minutes, and placed in a separatory funnel and allowed to stand for 30 minutes to obtain an upper phase (41.2 g) and a lower phase (40.0 g). For analysis, the obtained lower phase (0.30 g), 1,2-dimethoxyethane (1.00 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the ¹⁹ F-NMR analysis, it was confirmed that the separated lower phase contained 39.3 g of fluorine-containing vinyl sulfonic acid 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. 2.60 g was separated as an initial stream, and then 34.2 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 (19.6 g) and 9.80 g of the fluorine-containing vinyl sulfonic acid fluoride (10) obtained in Example 1 were placed in a flask containing a stirrer, stirred for 30 minutes, and placed in a separatory funnel and allowed to stand for 30 minutes to obtain a lower phase (9.55 g). The obtained lower phase (0.30 g), 1,2-dimethoxyethane (1.00 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the ¹⁹ F-NMR analysis, it was confirmed that the separated lower phase contained 9.35 g of the fluorine-containing vinyl sulfonic acid fluoride (10).

[Example 18]
10.1 g of the fluorine-containing vinyl sulfonic acid fluoride (10) obtained in Example 1 and 50.5 g of an aqueous sodium hydrogen carbonate solution were placed in a flask containing 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 (50.1 g) and a lower phase (9.77 g). For analysis, the obtained lower phase (0.30 g), 1,2-dimethoxyethane (1.00 g), and benzotrifluoride (0.10 g) were mixed and analyzed by ¹⁹ F-NMR. As a result of the ¹⁹ F-NMR analysis, it was confirmed that the separated lower phase contained 9.64 g of fluorine-containing vinyl sulfonic acid fluoride (10).
In this example, ζ/ε was 5.0.

As shown in Examples 9 to 18, it was demonstrated that fluorine-containing vinyl sulfonic acid fluoride (3) or fluorine-containing vinyl sulfonate (4) obtained by reacting fluorine-containing vinyl sulfonic 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.

According to the production method of the present invention, fluorine-containing vinyl sulfonate fluoride (3) can be produced in a higher yield than in the past, and can therefore be suitably used in the production of raw materials for various fluorine-containing compounds, ion exchange resins, ion exchange membranes, salt electrolysis membranes, fuel cell membranes, membranes for redox flow batteries, membranes for water electrolysis, and the like. In addition, fluorine-containing vinyl sulfonate salts (4) that can be converted into various fluorine compounds can be produced. Furthermore, fluorine-containing vinyl sulfonate salts (3) and/or fluorine-containing vinyl sulfonate salts (4) can be separated, and the compounds used in the separation can be reused.

Claims (29)

The following general formula (3):

(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 following general formula (4):

(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):

(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 following formula:
The following general formula (2):
Midfielder (2)
(In the formula, M is K, Rb, or Cs.)
and reacting the resulting mixture with an alkali metal fluoride (2) represented by the formula:
A manufacturing method comprising: The method according to claim 1, wherein the reaction temperature is 60 to 250°C. The method according to claim 1 or 2, wherein the ratio (β/α) of the amount of substance (α) of the fluorine-containing vinyl sulfonic anhydride (1) to the amount of substance (β) of the alkali metal fluoride (2) is 1 to 100. The following general formula (3):

(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: The following general formula (4):

(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: The method according to claim 1, further comprising a step of separating the fluorine-containing vinyl sulfonic acid fluoride (3). The method according to claim 6, further comprising a step of distilling the fluorine-containing sulfonic acid fluoride (3). The method according to claim 6, further comprising a step of mixing the fluorine-containing sulfonic acid fluoride (3) with an extraction compound. The method according to claim 8, wherein the extraction 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. 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. The method according to claim 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. The method according to claim 8, further comprising a step of allowing the mixed solution obtained by the step of mixing the fluorine-containing sulfonic acid fluoride (3) with the extracting compound to stand and separating the mixed solution into a phase containing the fluorine-containing sulfonic acid fluoride (3) and a phase containing the extracting compound. The method according to claim 12, wherein the phase containing the extracted compound is reused in the step of mixing the fluorine-containing sulfonic acid fluoride (3) with the extracted compound. The method according to claim 12, further 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. The method of claim 1, further comprising a step of separating the reaction residue. The method according to claim 15, further comprising the step of mixing the reaction residue with a dissolving compound to prepare a fluorine-containing sulfonate solution. The method according to claim 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. 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. The method according to claim 16, further comprising a step of filtering the fluorine-containing sulfonate solution to obtain a filtrate containing the fluorine-containing sulfonate. 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). The method according to claim 20, wherein the residue containing the alkali metal fluoride (2) is reused in the reaction with the fluorine-containing vinyl sulfonic anhydride (1). The production method according to claim 19, comprising a step of separating a volatile component containing the dissolved compound from the fluorine-containing sulfonate-containing filtrate to obtain the fluorine-containing sulfonate (4). The method according to claim 22, wherein the volatile components containing the dissolved compound are reused in a step of mixing the reaction residue with the dissolved compound to prepare a fluorine-containing sulfonate solution. The method according to claim 19, further comprising the step of adding water to the filtrate containing the fluorine-containing sulfonate and mixing it. The method according to claim 24, wherein the 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. The method according to claim 24, further comprising the step of adding water to the filtrate containing the fluorine-containing sulfonate, and separating volatile components containing the dissolved compound from the solution obtained by the step of mixing, thereby preparing an aqueous solution containing the fluorine-containing sulfonate. The method according to claim 26, further comprising a step of separating volatile components containing the dissolved compounds from the solution obtained by adding water to the fluorine-containing sulfonate-containing filtrate and mixing the filtrate, and separating water from the volatile components containing the dissolved compounds separated in the step of preparing the fluorine-containing sulfonate-containing aqueous solution. The method according to claim 26 or 27, wherein the volatile components containing the dissolved compound are reused in a step of mixing the reaction residue with the dissolved compound and preparing a fluorine-containing sulfonate solution. The method according to claim 24, wherein a volatile component containing the dissolved compound is separated from the solution obtained by the step of adding water to the fluorine-containing sulfonate-containing filtrate and mixing, and the water separated in the step of separating water from the volatile component containing the dissolved compound separated in the step of preparing the fluorine-containing sulfonate-containing aqueous solution is reused in the step of adding water to the fluorine-containing sulfonate-containing filtrate and mixing.