阅读说明：本技术 含磺酸基单体的制造方法 (Method for producing sulfonic acid group-containing monomer ) 是由 植松信之 长门康浩 堀开史 八木谷谦一 于 2019-02-13 设计创作，主要内容包括：本发明的目的在于提供一种能够以良好的收率制造含磺酸基单体的方法,该含磺酸基单体可成为燃料电池用隔膜、燃料电池用催化剂粘结剂聚合物、食盐电解用隔膜等氟系高分子电解质的原材料。本发明的通式(3)所表示的含磺酸基单体的制造方法的特征在于,其包括将通式(1)所表示的环状化合物与通式(2)所表示的硅烷醇化合物混合搅拌的工序。(The purpose of the present invention is to provide a method for producing a sulfonic acid group-containing monomer which can be used as a raw material for a fluorine-based polymer electrolyte such as a fuel cell separator, a fuel cell catalyst binder polymer, and a salt electrolysis separator, with good yield. The method for producing a sulfonic acid group-containing monomer represented by the general formula (3) of the present invention is characterized by comprising a step of mixing and stirring a cyclic compound represented by the general formula (1) and a silanol compound represented by the general formula (2).)

1. A method for producing a sulfonic acid group-containing monomer represented by the following general formula (3), which is characterized by comprising a step of mixing and stirring a cyclic compound represented by the following general formula (1) and a silanol compound represented by the following general formula (2),

[ solution 1]

In the formula (1), X is F or CF₃N is an integer of 1 to 6, and when n is 2 or more, each CFX is the same or different,

R¹R²R³Si(OM) (2)

in the formula (2), M is an alkali metal or an alkaline earth metal, R¹～R³Each independently is a C1-10 hydrocarbon group with or without substituent or OM, M in OM is alkali metal or alkaline earth metal,

CF₂＝CFO(CFX)_nSO₃Y (3)

in the formula (3), n and X are the same as those in the general formula (1), and Y is a hydrogen atom, M or R¹R²R³Si, and M, R therein¹～R³With M, R of said general formula (2)¹～R³The same is true.

2. The method for producing the sulfonic acid group-containing monomer according to claim 1, wherein the method comprises the steps of:

from the reaction mixture obtained in the above step, which contains the sulfonic acid group-containing monomer represented by the above general formula (3), and the siloxane represented by the following general formula (4) and/or the fluorine atom-containing silicon compound represented by the following general formula (5),

(i) separating and removing the siloxane represented by the general formula (4) and/or the fluorine atom-containing silicon compound represented by the general formula (5),

(ii) (ii) converting the siloxane represented by the general formula (4) and/or the fluorine atom-containing silicon compound represented by the general formula (5) separated and removed in the step (i) into a silanol compound represented by the general formula (2),

(iii) (iii) mixing and stirring the cyclic compound represented by the general formula (1) and the silanol compound represented by the general formula (2) obtained in the step (ii),

R¹R²R³SiOSiR¹R²R³(4)

in the formula (4), R¹～R³With R of said general formula (2)¹～R³In the same way, the first and second,

R¹R²R³SiF (5)

in the formula (5), R¹～R³With R of said general formula (2)¹～R³The same is true.

3. The method for producing the sulfonic acid group-containing monomer according to claim 1 or 2, wherein the silanol compound is a compound in which M in the general formula (2) is an alkali metal.

4. The method for producing the sulfonic acid group-containing monomer according to any one of claims 1 to 3, wherein the silanol compound is a compound selected from the group consisting of lithium trimethylsilanolate, lithium triethylsilanolate, lithium triisopropylsilanolate, lithium tert-butyldimethylsilanolate, lithium triphenylsilanolate, lithium dimethylsilanediol, lithium diethylsilanediol, dilithium diphenylsilanediol, sodium trimethylsilanolate, sodium triethylsilanolate, sodium triisopropylsilanolate, sodium tert-butyldimethylsilaneolate, sodium triphenylsilanolate, disodium dimethylsilanediol, disodium diethylsilanediol, and disodium diphenylsilanediol.

Technical Field

The present invention relates to a method for producing a sulfonic acid group-containing monomer. More specifically, the present invention relates to a method for producing a sulfonic acid group-containing monomer which can be used as a raw material for a fluorine-based polymer electrolyte such as a fuel cell separator, a fuel cell catalyst binder polymer, and a salt electrolysis separator, with a good yield.

Background

Disclosure of Invention

Problems to be solved by the invention

However, in practice, decarboxylation by heating is caused to proceed from CF₃CF(COF)O(CF₂)₂SO₂When a 5-membered cyclic compound obtained from F and sodium carbonate is reacted with sodium methoxide, a target sulfonic acid group-containing monomer (CF) is obtained₂＝CFO(CF₂)₂SO₃Na) is produced in a small amount, and a large amount of the presumed CH-containing substance is produced₃OCF₂CFH-or CF₃Complex reaction mixtures of compounds of the structure of CFH-. Presuming to have CH with respect to large amount of generation₃OCF₂CFH-or CF₃The reason why the compound having the structure of CFH-is produced is not clear, and it is considered that CH is produced₃OCF₂The reason why the compound having the structure of CFH-is presumably due to methoxy (CH)₃O^-) Readily added to vinyl (CF) produced by the reaction₂CF-).

Sulfonic acid group-containing monomer (CF) as cyclic compound not having 5-membered ring interposed therebetween₂＝CFO(CF₂)₂SO₃Na) and discloses the following processThe method comprises the following steps: make CF₃CF(COF)O(CF₂)₂SO₂F reacts with methanol to prepare methyl ester, and the methyl ester is neutralized by alcoholic sodium hydroxide to obtain powdery CF₃CF(CO₂Na)O(CF₂)₂SO₃Na, then decarboxylating by heating to obtain CF₂＝CFO(CF₂)₂SO₃And (4) Na. However, in CF₃CF(CO₂Na)O(CF₂)₂SO₃Prior to the decarboxylation reaction by heating of Na, it is necessary to completely remove alcohol and water and completely dry them, and therefore the reaction operation is complicated (for example, see patent document 3).

[ solution 6]

Therefore, in order to produce a fluorinated monomer represented by the above general formula (7) wherein p is 0, a method capable of producing a sulfonic acid group-containing monomer as a synthesis intermediate thereof in a good yield by an industrially advantageous method has been demanded.

The purpose of the present invention is to provide a method for producing a sulfonic acid group-containing monomer with good yield.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems and as a result, have found a method for obtaining a sulfonic acid group-containing monomer as a target product in a good yield by mixing and stirring a cyclic compound and a silanol compound, and have completed the present invention.

Namely, the present invention is as follows.

[1]

A method for producing a sulfonic acid group-containing monomer represented by the following general formula (3), characterized by comprising a step of mixing and stirring a cyclic compound represented by the following general formula (1) and a silanol compound represented by the following general formula (2).

[ solution 1]

(in the formula (1), X is F or CF₃N is an integer of 1 to 6, and when n is 2 or more, each CFX may be the same or different. )

R¹R²R³Si(OM)(2)

(in the formula (2), M is an alkali metal or an alkaline earth metal, R¹～R³Each independently is a C1-10 hydrocarbon group with or without a substituent or OM (M is alkali metal or alkaline earth metal). )

CF₂＝CFO(CFX)_nSO₃Y (3)

(in the formula (3), n and X are the same as those in the formula (1), and Y is a hydrogen atom, M or R¹R²R³Si(M、R¹～R³With M, R of the above general formula (2)¹～R³Same))

[2]

The method for producing a sulfonic acid group-containing monomer according to [1], which comprises the steps of:

from the reaction mixture obtained in the above step and containing the sulfonic acid group-containing monomer represented by the above general formula (3), and the siloxane represented by the following general formula (4) and/or the fluorine atom-containing silicon compound represented by the following general formula (5),

(i) separating and removing the siloxane represented by the general formula (4) and/or the fluorine atom-containing silicon compound represented by the general formula (5),

(ii) (ii) converting the siloxane represented by the general formula (4) and/or the fluorine atom-containing silicon compound represented by the general formula (5) separated and removed in the above (i) into a silanol compound represented by the above general formula (2),

(iii) the cyclic compound represented by the above general formula (1) and the silanol compound represented by the above general formula (2) obtained in the above (ii) are mixed and stirred.

R¹R²R³SiOSiR¹R²R³(4)

(in the formula (4), R¹～R³With R of the above general formula (2)¹～R³Same)

R¹R²R³SiF(5)

(in the formula (5), R¹～R³With R of the above general formula (2)¹～R³Same)

[3]

The process for producing a sulfonic acid group-containing monomer according to [1] or [2], wherein the silanol compound is a compound in which M in the general formula (2) is an alkali metal.

[4]

The method for producing a sulfonic acid group-containing monomer according to any one of [1] to [3], wherein the silanol compound is a compound selected from the group consisting of lithium trimethylsilanolate, lithium triethylsilanolate, lithium triisopropylsilanolate, lithium tert-butyldimethylsilanolate, lithium triphenylsilanolate, lithium dimethylsilanediol, lithium diethylsilanediol, dilithium diphenylsilanediol, sodium trimethylsilanolate, sodium triethylsilanolate, sodium triisopropylsilanolate, sodium tert-butyldimethylsilaneolate, sodium triphenylsilanolate, disodium dimethylsilanediol, disodium diethylsilanediol, and disodium diphenylsilanediol.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a sulfonic acid group-containing monomer can be produced in a good yield.

Detailed Description

The following describes in detail a specific embodiment of the present invention (hereinafter, simply referred to as "the present embodiment").

The present invention relates to a method for producing a sulfonic acid group-containing monomer represented by the following general formula (3), which comprises a step of mixing and stirring a cyclic compound represented by the following general formula (1) and a silanol compound represented by the following general formula (2).

[ solution 1]

(in the formula (1), X is F or CF₃N is an integer of 1 to 6, and when n is 2 or more, eachThe CFX may be the same or different. )

R¹R²R³Si(OM)(2)

(in the formula (2), M is an alkali metal or an alkaline earth metal, R¹～R³Each independently is a C1-10 hydrocarbon group with or without a substituent or OM (M is alkali metal or alkaline earth metal). )

CF₂＝CFO(CFX)_nSO₃Y (3)

(in the formula (3), n and X are the same as those in the formula (1), and Y is a hydrogen atom, M or R¹R²R³Si(M、R¹～R³With M, R of the above general formula (2)¹～R³Same))

In the present specification, the cyclic compound represented by the general formula (1) may be referred to as "compound (1)", the silanol compound represented by the general formula (2) may be referred to as "compound (2)", and the sulfonic acid group-containing monomer represented by the general formula (3) may be referred to as "compound (3)".

< Cyclic Compound (1) >

In the compound (1), X is F or CF₃N is an integer of 1 to 6, and when n is 2 or more, each CFX may be the same or different, and X is preferably F or CF in view of availability and ease of synthesis of the compound (1)₃N is preferably 2 to 4.

Compound (1) can be obtained, for example, by deriving from CF₃CF(COF)O(CFX)_nSO₂F (X is F or CF)₃And n is an integer of 1 to 6) is synthesized by thermal decomposition of an alkali metal carboxylate (see, for example, patent document 2).

< silanol Compound (2) >

In the compound (2), M is an alkali metal or an alkaline earth metal, and preferably, M is an alkali metal in view of availability and ease of synthesis of the compound (2). The alkali metal is preferably lithium, sodium or potassium, and particularly preferably lithium or sodium in view of reactivity with the compound (1). In the compound (2), when 2 or more M are present in 1 molecule, each M may be the same or different, and is preferably the same.

In the compound (2), R¹～R³Each independently is a C1-10 hydrocarbon group with or without a substituent or OM (M is alkali metal or alkaline earth metal). Each R is¹～R³May be the same or different.

As R¹～R³Examples of the "hydrocarbon group having or not having a substituent" in (1) include an aromatic hydrocarbon group such as an aliphatic hydrocarbon group or a phenyl group, and a fluorine-substituted hydrocarbon group such as a trifluoromethyl group in which all hydrogen atoms in the hydrocarbon group are substituted by fluorine atoms.

The hydrocarbon group may have a functional group as needed. Examples of such functional groups include halogen atoms such as a fluorine atom, a chlorine atom and a bromine atom, a nitrile group (-CN), an ether group (-O-), and a carbonate group (-OCO)₂-) an ester group (-CO)₂-), carbonyl (-CO-), sulfide (-S-), sulfoxide (-SO-), sulfone (-SO-), and the like₂-), carbamate (-NHCO)₂-) and the like.

With respect to R¹～R³The number of carbon atoms of each hydrocarbon group is 1 to 10, but the number of carbon atoms is more preferably 1 to 8 for the availability of the compound (2), and particularly preferably 1 to 6 from the viewpoint of reactivity with the compound (1).

As R¹～R³The following can be illustrated: aliphatic hydrocarbon groups such as methyl, ethyl, vinyl, allyl, 1-methylvinyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, and fluoromethyl; aromatic hydrocarbon groups such as benzyl, phenyl, nitrile-substituted phenyl, and fluorinated phenyl; and the like, more preferably methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, benzyl, phenyl, and particularly preferably methyl, ethyl, isopropyl, tert-butyl, phenyl.

Examples of the compound (2) include lithium trimethylsilanolate, lithium triethylsilanolate, lithium triisopropylsilanolate, lithium tert-butyldimethylsilanolate, lithium triphenylsilanolate, lithium dimethylsilanediol, lithium diethylsilanediol, lithium diphenylsilanediol, sodium trimethylsilanolate, sodium triethylsilanolate, sodium triisopropylsilanolate, sodium tert-butyldimethylsilanealkoxide, sodium triphenylsilanolate, disodium dimethylsilanediol, disodium diethylsilanediol, and disodium diphenylsilanediol.

The compound (2) may be a commercially available compound or may be synthesized from a compound obtainable from, for example, a halosilane, silanol, siloxane, or the like.

As a method for synthesizing the compound (2), for example, a halosilane (R) can be synthesized as shown below¹R²R³SiZ) (in the formula, R¹～R³The same as in the compound (2). Z represents a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and when Z represents a fluorine atom, the same as in the case of the compound (5) is converted into silanol (R) by hydrolysis¹R²R³SiOH) (wherein R is¹～R³Same as in the compound (2) or a siloxane (R)¹R²R³SiOSiR¹R²R³) (in the formula, R¹～R³The same as in the compound (2), and then in the case of silanol, the same as in the compound (2), M, MH, RM, etc. R represents an alkyl group having 1 to 10 carbon atoms or an aryl group), and MOH and M in the case of siloxane₂O、MNH₂And RM, wherein R represents an alkyl group or an aryl group having 1 to 10 carbon atoms, and M is the same as in the compound (2), thereby synthesizing the compound (2).

Examples of M used in the reaction with silanol include L i, Na, K and the like, examples of MH include L iH, NaH, KH and the like, and examples of RM include n-C₄H₉Li、sec-C₄H₉Li、tert-C₄H₉Li、CH₃Li、C₆H₅Li、n-C₄H₉Na、n-C₄H₉K, and the like. Among them, MH and RM are preferable, NaH, KH and n-C are more preferable, from the viewpoint of reactivity with silanol and reaction operability in the case of industrial treatment₄H₉Li、CH₃Li。

The amount of M, MH, and RM used is preferably 0.95 to 2mol based on 1 mol of the hydroxyl group in the silanol. The reaction temperature is preferably-100 to 200 ℃ and the reaction time is preferably 0.01 to 100 hours.

Examples of MOH used in the reaction with siloxane include L iOH, NaOH, KOH and the like, and M is₂O, L i₂O、Na₂O、K₂O, etc. as MNH₂L iNH can be mentioned₂、NaNH₂、KNH₂Etc. as RM, n-C may be mentioned₄H₉Li、sec-C₄H₉Li、tert-C₄H₉Li、CH₃Li、C₆H₅Li、n-C₄H₉Na、n-C₄H₉K, and the like. Among these, MOH and RM are preferable, and NaOH, KOH and n-C are more preferable, from the viewpoint of reactivity with siloxane and reactivity in industrial processing₄H₉Li、CH₃Li。

The MOH and M are contained in an amount of 1 mol based on a siloxane bond (Si-O-Si) in the siloxane₂O、MNH₂The amount of RM to be used is preferably 0.95 to 4 mol, the reaction temperature is preferably-100 to 200 ℃ and the reaction time is preferably 0.01 to 100 hours, it is noted that, in the case of MOH, water may be produced in the reaction system, and for example L iH, NaH, KH, MgO, CaO, CaCl may be added to the reaction system to remove the produced water₂、MgSO₄、Na₂SO₄L iH, NaH, KH, MgO, CaO, CaCl, and the like in an amount of 1 mole based on the siloxane bond (Si-O-Si) in the above-mentioned siloxane₂、MgSO₄、Na₂SO₄The amount of (B) is preferably 0.95 to 4 mol. The amount of the molecular sieve or activated alumina to be used is preferably 1 to 180g based on 1 mol of siloxane bond (Si-O-Si) in the siloxane.

[ solution 9]

< production of sulfonic acid group-containing monomer (Compound (3) >

The compound (3) can be obtained by mixing and stirring the compound (1) and the compound (2).

The detailed reason why the compound (3) can be obtained in a good yield by mixing and stirring the compound (1) and the compound (2) is not clear, but it is presumed that the compound (2) is used to open the ring of the compound (1) to form a silyl sulfonate (CF)₂＝CFO(CFX)_nSO₃SiR¹R²R³) Further, the compound (3) is produced by a cleavage reaction of an O-Si bond by the compound (2) and/or the Metal Fluoride (MF).

[ solution 10]

As mentioned above, in the presence of, for example, sodium methoxide (NaOCH)₃) Instead of reacting the compound (2) with a 5-membered cyclic compound, a sulfonic acid group-containing monomer (CF) as a target compound₂＝CFO(CF₂)₂SO₃Na) is produced in a small amount, and a large amount of the presumed CH-containing substance is produced₃OCF₂CFH-or CF₃Complex reaction mixtures of compounds of the structure of CFH-. In addition, even if potassium tert-butoxide (KOtC), known as a bulky base, is used₄H₉) Instead of the compound (2), a 5-membered cyclic compound is reacted with a sulfonic acid group-containing monomer (CF) as a target₂＝CFO(CF₂)₂SO₃K) The amount of generation of (2) is small, and a large amount of generated estimated tC₄H₉OCF₂CFH-or CF₃Complex reaction mixtures of compounds of the structure of CFH-.

For these reasons, the reason why the compound (3) is obtained from the compound (1) and the compound (2) in a good yield is presumably that the compound (2) is a silicon compound and has a bulky structure, and therefore the compound (2) is difficult to be added to the vinyl moiety of the compound (3) to be produced.

In the production method of the present embodiment, a solvent is preferably used for mixing and stirring.

The solvent may be inert during the reaction, and various aprotic polar solvents may be used, and examples thereof include various ether group-containing solvents such as tetrahydrofuran, 1, 2-dimethoxyethane, 1, 2-diethoxyethane, 1, 4-dioxane, cyclopentyl methyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether and 4-methyltetrahydropyran, nitrile group-containing solvents such as acetonitrile, and sulfone group-containing solvents such as sulfolane. Among them, an ether group-containing solvent such as tetrahydrofuran, 1, 2-dimethoxyethane, 1, 2-diethoxyethane, 4-methyltetrahydropyran or the like is preferably used because the compound (3) can be obtained in a good yield.

In the production method of the present embodiment, the amount of the compound (2) to be used is preferably not less than a molar equivalent to the compound (1), more preferably 1 to 4 times the molar equivalent of the compound (1), and most preferably 1 to 3 times the molar equivalent of the compound (1).

The mixing and stirring temperature is preferably-80 ℃ to 100 ℃, more preferably-50 ℃ to 80 ℃.

The mixing and stirring time is preferably 0.01 to 50 hours, more preferably 0.1 to 10 hours.

In the production method of the present embodiment, a proton adduct represented by the following general formula (8) (hereinafter referred to as compound (8)) may be produced as a by-product together with the target compound (3)

CF₃CFHO(CFX)_nSO₃Y(8)

(in the formula (8), n and X are the same as those in the above general formula (1), and Y is a hydrogen atom, M or R¹R²R³Si(M、R¹～R³And M, R in the above general formula (2)¹～R³The same applies), for example, as described in non-patent document 2, it is known that when a bulky base such as lithium hexamethyldisilazide is added to the compound (8), the compound (8) can be easily converted to the compound (3).

In the production method of the present embodiment, a siloxane represented by the following general formula (4) (hereinafter referred to as compound (4)) and/or a fluorine atom-containing silicon compound represented by the following general formula (5) (hereinafter referred to as compound (5)) is produced as a by-product produced together with the target compound (3) in addition to the compound (8).

R¹R²R³SiOSiR¹R²R³(4)

(in the formula (4), R¹～R³And R in the above general formula (2)¹～R³Same)

R¹R²R³SiF(5)

(in the formula (5), R¹～R³And R in the above general formula (2)¹～R³Same)

Further, by this reaction, a Metal Fluoride (MF) (M is the same as in the above general formula (2)) may be present in the reaction system. The detailed reasons for obtaining the compound (4), the compound (5) and the Metal Fluoride (MF) as by-products are not clear, and it is presumed that these are by-products by the above-mentioned mechanism.

In the production method of the present embodiment, the present inventors also conducted detailed studies on the following methods: from a reaction mixture containing the compound (3) as a target and the compound (4) and/or the compound (5) as a by-product, which is obtained by mixing and stirring the compound (1) and the compound (2), (i) after separating and removing the compound (4) and/or the compound (5), (ii) after further converting the separated and removed compound (4) and/or the compound (5) into the compound (2), (iii) after that, the compound (1) and the compound (2) obtained in the above (ii) are mixed and stirred to obtain the compound (3), and an industrially advantageous production method is found by this study, and therefore, this method will be described below.

As a method for separating and removing each of the compound (3) as the target product and the compound (4) and/or the compound (5) as the by-product from the reaction mixture, various removal methods can be employed. Examples thereof include separation and removal by distillation, extraction and separation and removal by an organic solvent or water, and the like. When the Metal Fluoride (MF) is precipitated and suspended to form a suspension, the metal fluoride may be removed by filtration in advance and then separated and purified.

For example, in a separation and removal method using a distillation operation, the solvent used and the compound (4) and/or the compound (5) may be distilled off from the solution or suspension after the reaction by the distillation operation, thereby obtaining the compound (3). The distilled product containing the distilled solvent, the compound (4) and/or the compound (5) may be further subjected to a distillation operation, an extraction operation, or the like to separate the solvent, the compound (4) and/or the compound (5), respectively.

In the method of extraction, separation and removal using an organic solvent or water, for example, after the solvent used is distilled off from the solution or suspension after the reaction by a distillation operation or the like, the compound (3) is dissolved by adding water to the residue, and therefore the compound (3) can be obtained by a filtration operation or the like.

As for the compound (4) and/or the compound (5) obtained by the above separation and removal operation, as described in the synthesis of the silanol compound (2)), the compound (4) and/or the compound (5) can be easily converted into the compound (2), and when they are mixed with the compound (1) again and stirred, the compound (3) can be obtained.

As described above, the present invention can efficiently produce a sulfonic acid group-containing monomer that is a raw material of various fluorine-based polymer electrolytes such as a fuel cell separator, a fuel cell catalyst binder polymer, and a salt electrolysis separator having high heat resistance.