JP4788267B2 - Polymer having fluorosulfonyl group and 1,3-dioxolane structure and use thereof - Google Patents

Description

  The present invention relates to a polymer having a fluorosulfonyl group and a perfluoro (1,3-dioxolane) structure. The present invention also relates to a method for producing the polymer and a compound useful in the production method. The present invention also relates to a novel fluoropolymer obtained from the polymer and its use as a solid polymer electrolyte.

Polymers having sulfonyl groups or derivatives thereof used for ion exchange membranes for salt electrolysis, solid polymer electrolytes for fuel cells, etc. (hereinafter, polymers having sulfonyl groups or derivatives thereof are collectively referred to as sulfonic acid polymers) .) Is a polymer obtained by polymerizing the compound represented by the following formula (1), followed by hydrolysis and acid treatment.
CF ₂ = CF (OCF ₂ CFY) _m1 (O) _m2 (CF ₂ ) _m3 SO ₂ F (1)
Y represents a fluorine atom or a trifluoromethyl group, m1 represents an integer of 0 to 3, m2 represents 0 or 1, and m3 represents an integer of 1 to 12.

  Patent Document 1 exemplifies a compound represented by the following formula (p).

However, ^{R p} is fluorine atom, an etheric oxygen atom which may contain a perfluoroalkyl group or a ^-Q p SO ₂ F 1 to 14 carbon atoms, ^{Q p} is etheric oxygen 1 to 14 carbon atoms A perfluoroalkylene group which may contain an atom is shown.

JP-A 64-0779170

  As a sulfonic acid polymer having a high softening temperature, a polymer having a fluorine atom has been proposed. Since the polymer electrolyte fuel cell needs to increase the power generation efficiency, it is desirable to operate at a high temperature (for example, operation at 120 ° C.). However, the conventional sulfonic acid polymer has a low softening temperature of about 80 ° C. and has insufficient physical properties as a solid polymer electrolyte for a fuel cell operated at a high temperature.

In addition, synthesis of sulfonic acid polymers having fluorine atoms is generally difficult, and the types of polymers actually provided are limited. For example, the method for producing the compound represented by the formula (p) is unknown. Further, even if the compound is obtained, the number of carbon atoms of Q ^p is 7 or more compounds (p) acid polymer obtained by polymerizing is insufficient softening temperature, the polymer electrolyte for high temperature operation It is insufficient as a solid polymer electrolyte used in a fuel cell.

  The present inventors believe that a sulfonic acid polymer having a high softening temperature can be produced from a monomer having a structure in which a specific group containing a fluorosulfonyl group is bonded to the 2-position of a perfluoro (1,3-dioxole) structure. It was. And the knowledge that this sulfonic acid polymer is useful as a solid polymer electrolyte was obtained. That is, the present invention provides the following inventions.

  <1>: A polymer containing a monomer unit represented by the following formula (A).

Where R ^F represents a fluorine atom, a C 1-6 perfluoroalkyl group, a C 2-6 carbon-carbon bond-containing perfluoroalkyl group containing an etheric oxygen atom, or —Q ^F SO ₂ F; ^F represents a perfluoroalkylene group having 1 to 6 carbon atoms or a perfluoroalkylene group containing an etheric oxygen atom between carbon-carbon bonds having 2 to 6 carbon atoms.

  <2>: The polymer of <1>, wherein the monomer unit represented by the formula (A) is a monomer unit represented by the following formula (A2).

However, R ^F2 represents a fluorine atom, a C 1-6 perfluoroalkyl group or —Q ^{F 2} SO ₂ F, and Q ^{F 2} is a perfluoroalkylene containing an etheric oxygen atom between C 2 -C 6 carbon-carbon bonds. Indicates a group.

<3>: The polymer of <1> or <2> having a number average molecular weight of 5000 to 5000000.
<4>: Method for producing a polymer containing the monomer unit represented by the following formula (A) for polymerizing the compound represented by the following formula (a) (wherein R ^F and Q ^F have the same meaning as described above) .)

<5>: A method for producing a compound represented by the following formula (a) in which a compound represented by the following formula (a-1) is dehalogenated in the presence of a dehalogenating agent (however, X ¹ and X ² each independently represents a chlorine atom or a bromine atom, and R ^F and Q ^F have the same meaning as described above.

<6>: A compound represented by the following formula (a-1) (provided that X ¹ , X ² , R ^F and Q ^F have the same meaning as described above).

<7>: A compound represented by the following formula (a2) (provided that R ^F2 and Q ^F2 have the same meaning as described above).

  <8>: A fluoropolymer containing a monomer unit represented by the following formula (B).

However, Q ^F has the same meaning as described above. R ^FB is a fluorine atom, perfluoroalkyl group having 1 to 6 carbon atoms, carbon atoms of 2 to 6 carbon atoms - a perfluoroalkyl group containing an etheric oxygen atom between carbon bond or _{^{-Q F (SO 2 Y, -}} (SO 2 R ^f ) _s ) M ⁺ group, Y represents an oxygen atom, a nitrogen atom, or a carbon atom, R ^f represents a perfluoroalkyl group that may contain an etheric oxygen atom, and s corresponds to Y , 0 when Y is an oxygen atom, 1 when Y is a nitrogen atom, 2 when Y is a carbon atom, M ⁺ is H ⁺ , a monovalent metal cation, or 1 represents ammonium in which one or more hydrogen atoms may be substituted with a hydrocarbon group.

  The present invention provides a compound useful as a monomer, an intermediate thereof, and a novel polymer obtained by polymerizing the compound. The present invention also provides novel fluoropolymers. The fluoropolymer of the present invention is a fluoropolymer having a high softening temperature and is excellent in mechanical strength even at a high temperature of about 120 ° C. That is, according to the present invention, a novel fluoropolymer useful as a solid polymer electrolyte suitable for high temperature use is provided.

  In this specification, a compound represented by the formula (a) is referred to as a compound (a), and a monomer unit represented by the formula (A) is referred to as a monomer unit (A). The same applies to compounds and monomer units represented by other formulas.

The present invention provides a polymer containing a monomer unit (A) represented by the following formula (hereinafter, simply referred to as polymer A) (provided that R ^F and Q ^F have the same meaning as described above. The same applies hereinafter). .)

When R ^F is a C 1-6 perfluoroalkyl group, a linear group is preferable, — (CF ₂ ) _n1 F (n1 is an integer of 1 to 4) is more preferable, and —CF ₃ is particularly preferable. .
When R ^F is a perfluoroalkyl group containing an etheric oxygen atom between a carbon-carbon bond having 2 to 6 carbon atoms, a straight-chain group is more preferable, and — (CF ₂ ) _n2 F (n2 is 2 to 4). In which an etheric oxygen atom is inserted between carbon-carbon bonds.
^{Q F} where R ^F is ^-Q F SO ₂ F is, ^{Q F} the same structure in another ^-Q F SO ₂ F attached to the 2-position carbon atom of the 1,3-dioxole are preferred.
R ^F is preferably a fluorine atom or a C 1-6 perfluoroalkyl group, more preferably —CF ₃ .

When Q ^F is a ^C 1-6 perfluoroalkylene group, a linear group is preferable, and — (CF ₂ ) _m1 — (m1 is an integer of 2 to 4) is particularly preferable.
Q ^F is carbon 2 to 6 carbon atoms - if a perfluoroalkylene group containing an etheric oxygen atom between carbon bond, more preferably a linear _{group, - (CF 2) m2 -} (m2 2-4 A group in which one etheric oxygen atom is inserted between carbon-carbon bonds, and a group represented by the formula —CF ₂ O (CF ₂ ) _m21 — (m21 is an integer of 1 to 3). However, the direction of the group means that the right side is bonded to —SO ₂ F. The same applies hereinafter.)

  As the monomer unit (A), the following monomer unit (A1) is preferable from the viewpoint of the softening temperature, and the following monomer unit (A2) is preferable from the viewpoint of the softening temperature and availability (hereinafter, the monomer unit (A1) is referred to as the monomer unit (A1)). The polymer containing the polymer A1 and the polymer containing the monomer unit (A2) are referred to as a polymer A2.)

^{However, R F1} is a fluorine atom or or perfluoroalkylene Le group having 1 to 6 carbon atoms ^{-Q F1} SO ₂ ^{F, Q} F1 represents a perfluoroalkylene group having 1 to 6 carbon ^{atoms, R F2} and ^{Q F2} is the Indicates the same meaning (the same shall apply hereinafter).
R ^F2 is preferably a trifluoromethyl group. Q ^F2 is preferably a group represented by the formula —CF ₂ O (CF ₂ ) _m21 —.

  Specific examples of the monomer unit (A1) include the following monomer units.

  Specific examples of the monomer unit (A2) include the following monomer units.

  The polymer A can be produced by polymerizing the following compound (a).

  As the compound (a), the following compound (a1) or the following compound (a2) is preferable. Polymer A1 can be produced by polymerizing the following compound (a1), and polymer A2 can be produced by polymerizing the following compound (a2).

  Specific examples of the compound (a1) include the following compounds.

  Specific examples of the compound (a2) include the following compounds.

Even if the polymer A is a polymer comprising the monomer unit (A), the polymer A includes a monomer unit (A) and a monomer unit other than the monomer unit (A) (hereinafter simply referred to as other monomer units). (Hereinafter simply referred to as a copolymer), and is preferably a copolymer.
The copolymer can be produced by polymerizing the compound (a) and a monomer that can be copolymerized with the compound (a) other than the compound (a) (hereinafter simply referred to as another monomer). The arrangement of the monomer units in the copolymer may be random or block, and is preferably random from the viewpoint of ease of polymerization.

  When the polymer A is a copolymer, the ratio of the monomer unit (A) to the total monomer units in the polymer A is 1 to 70 mol from the viewpoint of improving the solubility of the fluoropolymer described later, dimensional stability, and the like. % Is preferable, 5 to 40 mol% is more preferable, and 10 to 30 mol% is particularly preferable. Moreover, 30-99 mol% is preferable, as for the ratio of the other monomer unit with respect to all the monomer units in the polymer A, 60-95 mol% is more preferable, and 70-90 mol% is especially preferable.

  Other monomer units may or may not contain fluorine atoms, and other monomer units containing fluorine atoms are preferred from the viewpoint of heat resistance, water resistance, solvent resistance and durability of the fluoropolymer described below. From the viewpoint of moldability, other monomer units that do not contain a fluorine atom are preferred.

The other monomer unit containing a fluorine atom is preferably a monomer unit formed by polymerization of another monomer containing a fluorine atom. As the other monomer containing a fluorine atom, the following monomer (m1), the following monomer (m2) or the following monomer (m3) is preferable.
CHZ ¹ = CZ ² Z ³ (m1),
CFZ ⁴ = CZ ⁵ Z ⁶ (m2),
_{CF 2 = CFQCF = CF 2 (} m3).

However, the symbol in a formula shows the following meaning.
Z ¹ , Z ² and Z ³ : each independently a hydrogen atom, a fluorine atom, a chlorine atom or a polyfluoroalkyl group having 1 to 12 carbon atoms, at least one of which is a fluorine atom or a porfluoro having 1 to 12 carbon atoms It is an alkyl group.
Z ⁴ , Z ⁵ and Z ⁶ each independently represent a fluorine atom, a chlorine atom or a perfluoroalkyl group which may have a C 1-12 etheric oxygen atom. Or two groups selected from Z ⁴ , Z ⁵ and Z ⁶ together form a divalent fluorine-containing saturated organic group, and the remaining one group is a fluorine atom or a monovalent fluorine-containing saturated organic group. May be.
_{Q: -CF 2 CF 2 -,} - CF 2 O -, - CF 2 CF 2 O -, - CF (CF 3) CF 2 O-, or _{-CF 2 CF (CF 3) O-} .

Examples of the monomer _{(m1), CH 2 = CHF} , CH 2 = CF 2, CHF = CHF or CHF = CF ₂ is preferred.
As the monomer (m2), CF ₂ = CF ₂ , CF ₂ = CFCl, CF ₂ = CF (CF ₃ ), the following compound (m21), the following compound (m22) or CF ₂ = CF (OCF ₂ CF (CF _{3) )) a O (CF 2)} b F is preferred (where, a is .b represents an integer of 0 to 3 is an integer of 1-8.).

However, R < ¹¹ > and R < ¹² > shows a fluorine atom or a C1-C6 perfluoroalkyl group each independently. R ²¹ and R ²² each independently represent a fluorine atom or a C 1-3 perfluoroalkyl group. R ²³ represents a fluorine atom or a perfluoroalkoxy group having 1 to 3 carbon atoms.

  Specific examples of the monomer (m21) include the following units.

  Specific examples of the monomer (m22) include the following units.

Monomer The _{(m3), CF 2 = CFCF} 2 OCF = CF 2, CF 2 = CFCF (CF 3) OCF = CF 2, CF 2 = CFCF 2 CF 2 OCF = CF 2, CF 2 = CFCF (CF 3) CF ₂ OCF═CF ₂ or CF ₂ ═CFCF ₂ CF (CF ₃ ) OCF═CF ₂ is preferred.

When the below-mentioned fluoropolymer synthesized from the polymer A, which is a copolymer, is used for a solid polymer electrolyte for a fuel cell, another monomer containing a fluorine atom is CF ₂ = CF ₂ from the viewpoint of durability. From the viewpoint of gas permeability and softening temperature, the monomer (m21), the monomer (m22), or the monomer (m3) is preferable. In addition, the other monomer when a fluoropolymer described later is used as a material for a lithium ion battery is preferably CH ₂ = CF ₂ from the viewpoint of compatibility with other additives.

The polymer A may contain a monomer unit formed by polymerization of another monomer that does not contain a fluorine atom. Other monomers containing no fluorine _{atom, CH 2 = CH 2, CH} 2 = CHCl, CH 2 = CCl 2, preferably vinyl ether or vinyl ester, more preferably _CH 2 = CH ₂ from the viewpoint of moldability.

Other monomers and other monomer combinations where polymer A is a copolymer are CF ₂ = CF ₂ only, CF ₂ = CF ₂ and CH ₂ = CH ₂ , CF ₂ = CF ₂ and CH ₂ = CF ₂ , CH ₂ = CF ₂ only, CH ₂ = CF ₂ and monomer (m21), CF ₂ = CF ₂ and monomer (m21) or CF ₂ = CF ₂ and monomer (m22) are preferred, CF ₂ = CF ₂ Only, or CF ₂ = CF ₂ and the monomer (m22) are more preferred.

From the viewpoint of mechanical strength, the lower limit of the number average molecular weight of the polymer A is preferably 5000, more preferably 10,000, and particularly preferably 20000. The upper limit of the number average molecular weight of the polymer A is preferably 5 million, and more preferably 2 million, from the viewpoint of solvent solubility and molding processability of the fluoropolymer described later.
In addition, the value obtained by converting the molecular weight of the polymer A into the molecular weight per —SO ₂ F is preferably 500 to 1500 from the viewpoint of water resistance, durability, dimensional stability, and the like of the fluoropolymer described below. 550 to 1200 is more preferable, and 600 to 900 is particularly preferable.

The production of the polymer A is preferably performed by a method in which the compound (a) is polymerized in the presence of radiation (ultraviolet rays, γ rays, electron beams, etc.) or in the presence of a radical initiator.
As the radical initiator, peroxides, azo compounds, persulfates and the like can be used. As the polymerization initiator, it is preferable to use perfluorodiacyl peroxide or perfluorodialkyl peroxide from the viewpoint of obtaining polymer A having excellent durability.
The polymerization temperature is preferably 20 ° C to 150 ° C. The polymerization pressure is not particularly limited. The polymerization method is not particularly limited, and a bulk polymerization method, a solution polymerization method, a suspension polymerization method, an emulsion polymerization method, or the like can be employed.

The boiling point of the solvent used in the solution polymerization method is preferably 20 ° C to 350 ° C, particularly preferably 40 ° C to 150 ° C, and one or more types can be used.
Examples of the solvent include polyfluorotrialkylamine compounds, perfluoroalkanes, hydrofluoroalkanes, chlorofluoroalkanes, fluoroolefins having no double bond at the molecular chain end, polyfluorocycloalkanes, polyfluorocyclic ether compounds, hydrofluoro Examples include ether and t-butanol. Supercritical carbon dioxide may be used as a solvent.

  The polymer A directly produced by the polymerization is preferably subjected to a treatment for contacting with fluorine gas (hereinafter referred to as fluorination treatment). The unstable group (for example, a terminal group derived from a radical generator) in the polymer A is replaced by perfluorination or a fluorine atom by the fluorination treatment, and the durability of the polymer A is improved. The fluorine gas in the fluorination treatment is preferably diluted with an inert gas, and the concentration of the fluorine gas is preferably set to less than 0.1 to 100% by volume. Examples of the inert gas include nitrogen gas and argon gas.

The polymer A subjected to the fluorination treatment may be in a bulk state or may be dispersed or dissolved in a solvent. As the solvent, a fluorine-containing solvent usually used for fluorination treatment can be used. The temperature of the fluorination treatment is preferably 25 to 300 ° C., and particularly preferably 150 to 200 ° C. from the viewpoint of suppressing the elimination of —SO ₂ F in the polymer A. The contact time between the fluorine gas and the polymer A in the fluorination treatment is preferably 1 minute to 1 week, particularly preferably 1 hour to 50 hours.

  The compound (a) of the present invention is a novel compound. The compound (a) is preferably produced by dehalogenating the following compound (a-1) in the presence of a dehalogenating agent.

X ¹ and X ² are preferably chlorine atoms.

Q ^F in the dehalogenation reaction is preferably a ^C 3-6 perfluoroalkylene group or Q ^{F 2} . When the dehalogenation reaction is performed using the compound (a-1) in which Q ^F is any of these groups, the production of by-products is suppressed, and the compound (a) having high purity is obtained.
The dehalogenating agent is a reagent that releases X ¹ and X ² of the compound (a-1). When X ¹ and X ² are chlorine atoms, the dehalogenating agent is a dechlorinating agent. Use. As the dehalogenating agent, Zn, Na, Mg, Sn, Cu, or Fe is preferable, and Zn is more preferable from the viewpoint that low temperature reaction is possible. 1-20 times mole is preferable with respect to compound (a-1), and, as for the quantity of a dehalogenating agent, 2-8 times mole is more preferable. The temperature of the dehalogenation reaction is preferably 30 ° C to 100 ° C, more preferably 40 ° C to 70 ° C.

  The dehalogenation reaction is preferably performed in a polar solvent. As polar solvents, organic polarities such as dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidinone, N-methylimidazolidine, 1,4-dioxane, diclime, methanol, ethanol, acetic acid, acetic anhydride, acetonitrile, dimethyl sulfoxide, etc. A solvent or water is preferred. The reaction is preferably carried out in a reactive distillation format to obtain a distilled and purified compound (a).

As a method for producing the compound (a-1) in which X ¹ and X ² are chlorine atoms, the following compound (a-3) is reacted with chlorine gas under light irradiation to obtain the following compound (a-21). Next, a method in which the compound (a-21) is reacted in the presence of antimony trifluoride and antimony pentachloride is preferable.

The compound (a-3) in which R ^F is other than a fluorine atom is reacted with the following compound (a-6) in the presence of oxygen gas to obtain the following compound (a-5), and then the compound (a- 5) is reacted in the presence of a Lewis acid to obtain the following compound (a-4), and then the compound (a-4) and CH ₂ (OH) CH ₂ X ⁶ (X ⁶ is a chlorine atom or bromine). In the following, the same shall apply).
_{^{R FA -CF = CF-Q F}} SO 2 F (a-6),

_{^{R FA CF 2 C (O)}} -Q F SO 2 F (a-4).
However, R ^FA is a group which is the same as R ^F in the compound (a-3) when it becomes R ^FA CF ₂ —, and is a fluorine atom, a C 1-5 perfluoroalkyl group, a carbon number of 2 A perfluoroalkyl group containing an etheric oxygen atom between 5 carbon-carbon bonds is preferred.

Examples of the Lewis acid include aluminum chloride and aluminum fluoride chloride.
The reaction between compound (a-4) and CH ₂ (OH) CH ₂ X ⁶ is preferably carried out in the presence of a basic compound. Compound (a-3) may be produced by a method in which compound (a-4) and ethylene oxide are reacted in the presence of LiX ⁶ and water.

As the compound (a-6), the following compounds may be mentioned.
CF ₂ = CFCF ₂ CF ₂ SO ₂ F,
CF ₂ = CFCF ₂ CF ₂ CF ₂ CF ₂ SO ₂ F,
CF ₂ = CFCF ₂ OCF ₂ CF ₂ SO ₂ F,
_{CF 2 = CFCF 2 CF 2 OCF} 2 CF 2 SO 2 F.

  Among the compounds (a-3), the following compound (a1-31) may be produced using the following method 1, and the following compound (a2-31) may be produced using the following method 2.

Method 1: Compound (a1-31) is obtained by reacting the following compound (a1-71), the following compound (a1-6) and CF ₂ = CF ₂ to obtain the following compound (a1-51), The compound (a1-51) is reacted with chlorine gas to obtain the following compound (a1-41), and then the compound (a1-31) is subjected to a fluorination reaction in the presence of a fluorinating agent. ) Manufacturing method.
R ^a7 S ^- M ⁺ (a1-71)
R ^F1 C (O) OCH ₂ CH ₂ X ^a6 (a1-61)

However, ^Xa6 shows a chlorine atom or a bromine atom, ^Ra7 shows a C1-C20 hydrocarbon group and a C1-C8 hydrocarbon group is preferable. R ^a7 is preferably a group represented by the formula (R ⁷¹ ) (R ⁷² ) (R ⁷³ ) C— or a benzyl group. R ⁷¹ , R ⁷² and R ⁷³ may be the same group or different groups, are preferably the same group, and are particularly preferably a methyl group.

As the fluorinating agent in the fluorination reaction, KF, KHF ₂ , NaHF ₂ , NaF or CsF is preferable, KF or KHF ₂ is more preferable, and KHF ₂ is particularly preferable from the viewpoint of the simplicity of the reaction. The reaction temperature in the fluorination reaction is preferably 0 to 70 ° C, more preferably 0 to 50 ° C, and particularly preferably 0 to 50 ° C from the viewpoint of the reaction yield.

Method 2: The following compound (a2-8) and the following compound (a2-7) are reacted to obtain the following compound (a2-6), and then the compound (a2-6) is fluorinated to give the following compound (A2-5) was obtained, and then the compound (a2-5) was subjected to a thermal decomposition reaction in the presence of a metal fluoride to obtain the following compound (a2-41). method for producing a CH ₂ (OH) compounds reacting _CH 2 ^{X 6} _(a2-31).

^{_{FSO 2 CF 2 C (O)}} OCH (R 2) CH 2 OCF 2 CF 2 SO 2 F (a2-6),
FSO ₂ CF ₂ C (O) OCF (R ^F2 ) CF ₂ OCF ₂ CF ₂ SO ₂ F (a2-5),
R ^F2 C (O) CF ₂ OCF ₂ CF ₂ SO ₂ F (a2-41).
However R ² represents a group fluorinated carbon atoms sequence corresponding to R ^F2 and identical radicals or R ^F2 is converted to R ^F2. R ² is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

It is preferable to perform reaction of the following compound (a2-8) and the following compound (a2-7) using 2-5 times mole of compound (a2-7) with respect to compound (a2-8).
The reaction is preferably performed in the presence of a metal fluoride. As the metal fluoride, KF, KHF ₂ , NaHF ₂ , NaF or CsF is preferable. The reaction may be performed in the presence of a solvent or in the absence of a solvent, and is preferably performed in the presence of a polar solvent. As the polar solvent, organic polar solvents such as dimethylformamide, dimethylacetamide, 1,4-dioxane, diclime, and methanol are preferable.

The fluorination reaction of the compound (a2-6) is preferably performed using an electrochemical fluorination method (ECF method), a cobalt fluorination method, a gas phase fluorination method, or a liquid phase fluorination method. It is particularly preferable to use the liquid phase fluorination method from the viewpoint. The liquid phase fluorination method can be carried out by a method of reacting the compound (a2-6) and fluorine in a solvent.
A known method can be used for the thermal decomposition reaction of the compound (a2-5).

  Specific examples of the compound (a2-7) include the following compounds. Compound (a2-7s) is preferably produced using a method in which compound (a2-8) and epichlorohydrin are reacted in the presence of AgF.

The polymer of the present invention is a polymer essentially containing -SO ₂ F groups, some or all of the -SO ₂ F groups (preferably all.) The ^{_{-SO 2 Y - (SO 2 R}} f) s M Chemical conversion to a fluoropolymer having excellent ionic conductivity is preferred by chemical conversion to a ⁺ group (wherein the symbols in the formula have the same meaning as described above, the same shall apply hereinafter).
The present invention provides a fluoropolymer (hereinafter simply referred to as a fluoropolymer) containing the following monomer unit (B).

Formula _{^{- (SO 2 Y - (SO}} 2 R f) s) M + group group represented by (. Hereinafter, simply referred to as ionic groups), -SO ₃ Y is an oxygen atom s is 0 ^- M ^+, Y is is s is 1 nitrogen atom _{^{- (SO 2 N - SO 2}} R f) M +, or Y is and s is 2 carbon atoms _{^{- (SO 2 C - (SO}} 2 R ^f ) ₂ ) M ⁺ is preferred.
The M ^{+, H +,} alkali metal cations or ammonium of formula ^N + ^(R _{B) 4} (provided that four ^{R B} in the formula may be the same or different and each independently Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.), H ⁺ , lithium ion, sodium ion, potassium ion, NH ₄ ⁺ , N (CH ₃ ) ₄ ⁺ or N (CH ₂ CH ₂ CH ₂ CH ₃ ) ₄ ⁺ is more preferred.
R ^f is preferably a C 1-6 perfluoroalkyl group, more preferably —CF ₃ or —CF ₂ CF ₃ .

The fluoropolymer can be produced by treating the polymer A using a known method.
Among the fluoropolymers in which Y of the ionic group is an oxygen atom, a fluoropolymer having —SO ₃ ⁻ M ₁ ⁺ (wherein M ₁ ⁺ represents an alkali metal ion) represents polymer A as an alkali metal hydroxide. It can manufacture by the method of processing in the aqueous solution containing this. As the alkali metal hydroxide, sodium hydroxide or potassium hydroxide is preferable.

Fluoropolymers ionic group is -SO 3 _H, the ionic group was obtained by the method -SO ₃ ^- fluoropolymer is M ₁ ^+, can be prepared by methods further treated with an acid aqueous solution. As the acidic aqueous solution, a sulfuric acid aqueous solution or a hydrochloric acid solution is preferable.
_-SO ³ ionic groups - ^N + ^(R _B) fluoropolymer is _4, the ionic groups are _-SO ³ - in _M ^{1 +} or -SO ₃ H in which the fluoropolymer of formula ^{N (R} _{B) 3} It can manufacture by the method of processing in the aqueous solution containing the compound represented.
Among fluoropolymers Y ionizable group is a nitrogen atom ^{_{- (SO 2 N - (SO}} 2 R f)) fluoropolymer having a ^{M +} is a polymer ^{_{A (R f SO 2 NH 2}} ), alkali It can be produced by a method of reacting in the presence of a metal carbonate or an alkali metal fluoride. Examples of the alkali metal carbonate include Na ₂ CO ₃ and K ₂ CO ₃ . Examples of the alkali metal fluoride include NaF and KF.

When the fluoropolymer is used as a material for a solid polymer electrolyte (particularly a solid polymer electrolyte for a fuel cell), the ionic group of the fluoropolymer is preferably a —SO ₃ H group. The softening temperature of the fluoropolymer is preferably 90 ° C. or higher, more preferably 100 ° C. or higher, and particularly preferably 120 ° C. or higher. From the viewpoint of mechanical strength, the lower limit of the number average molecular weight of the fluoropolymer is preferably 5000, more preferably 10,000, and particularly preferably 20000. The upper limit of the number average molecular weight of the fluoropolymer is preferably 5 million and more preferably 2 million from the viewpoints of solvent solubility and moldability.

  The fluoropolymer of the present invention is a sulfonic acid polymer having a high softening temperature, and is useful as a solid polymer electrolyte, particularly a solid polymer electrolyte for a fuel cell. A solid polymer fuel cell comprising a solid polymer electrolyte containing the fluoropolymer of the present invention as an active ingredient can be operated at a high temperature (for example, operation at 120 ° C.).

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these.
In an embodiment, CF ₂ = CF ₂ is TFE, CF ₂ = CFOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ SO ₂ F is PSVE, and ((CH ₃ ) ₂ CHOC (O) O) ₂ is IPP. Azobisisobutyronitrile AIBN, CClF ₂ CF ₂ CHClF R-225cb, N, N-dimethyl sulfoxide DMSO, CF ₃ CF ₂ CF ₂ OCF (CF ₃ ) CF ₂ OCF (CF ₃ ) COF is abbreviated as (HFPO) ₃ respectively. The pressure is indicated by gauge pressure unless otherwise specified.
The softening temperature is determined by measuring the storage elastic modulus of a film obtained by acid treatment of a fluoropolymer according to a dynamic viscoelasticity measurement method under the conditions of dynamic viscoelasticity measurement of 1 Hz and a temperature increase rate of 2 ° C./min. It calculated | required from the intersection of the tangent in ° C and the tangent in storage elastic modulus 5x10 ⁷ Pa.

  [Example 1] Production Example of Compound (a11)

[Example 1-1] Production of Compound _{(a11-5) (CH 3) 3} CS - Na + (100g), CF 3 C (O) OCH 2 CH 2 Cl (166g), and 1,4-dioxane ( (1500 mL) was charged into an autoclave (internal volume 2500 mL), and freeze deaeration was performed. TFE (200 g) was supplied to the autoclave while maintaining the internal temperature of the autoclave at 20 to 30 ° C. The reaction was carried out by bringing the inside of the autoclave to 20 ° C. and stirring for 3 hours and further to 50 ° C. and stirring for 2 hours. Next, the autoclave was cooled and TFE was released to complete the reaction.

  The lower layer liquid of the two-layer separated liquid obtained by putting the autoclave contents into water was recovered. The lower layer liquid obtained by performing the same reaction and recovery twice in total was washed with water, dried over magnesium sulfate, and then distilled under reduced pressure to obtain a fraction (253 g) at (80 to 85) ° C./(267 to 400) Pa. ) As a result of analyzing the fraction, the production of the compound (a11-5) was confirmed.

¹ H-NMR (300.4 MHz, solvent: CDCl ₃ , standard: Si (CH ₃ ) ₄ ) δ (ppm): 1.53 ppm (9H), 4.20 to 4.35 ppm of compound (a11-5) 4H).
¹⁹ F-NMR (282.7 MHz, solvent: CDCl ₃ , standard: CFCl ₃ ) δ (ppm) of compound (a11-5): −79.45 ppm (3F), −84.30 ppm (2F), −118. 80 ppm (2F).

[Example 1-2] Production Example of Compound (a11-3) Compound (a11-) obtained in Example 1-1 while introducing chlorine gas into a 75 vol% acetonitrile aqueous solution (1 L) kept at 30 ° C or lower. 5) Acetonitrile (200 mL) containing (105 g) was added dropwise. After completion of dropping, the introduction of chlorine gas was stopped, and then chlorine in the acetonitrile aqueous solution was purged. Next, the lower layer liquid (211 g) of the two-layer separated liquid obtained by adding an aqueous acetonitrile solution to excess water was recovered.

Next, acetonitrile (200 g) and water (150 g) were added to the lower layer liquid (100 g), KHF ₂ (40 g) was added, and the mixture was stirred at 25 ° C. for 48 hours. Next, the lower layer liquid of the two-layer separated liquid obtained by adding water was recovered. Further, the lower layer liquid was washed with water, dried over magnesium sulfate, and distilled under reduced pressure to obtain a fraction (41 g) at (53 to 54) ° C./(533 to 667) Pa. As a result of analyzing the fraction, the production of the compound (a11-3) was confirmed.

¹ H-NMR (300.4 MHz, solvent: CDCl ₃ , standard: Si (CH ₃ ) ₄ ) δ (ppm) of compound (a11-3): 4.34 ppm (4H).
¹⁹ F-NMR (282.7 MHz, solvent: CDCl ₃ , standard: CFCl ₃ ) δ (ppm): 44.55 ppm (1F), −79.53 ppm (3F), −107.00 ppm of compound (a11-3) (2F), -118.05 ppm (2F).

[Example 1-3] Production example of compound (a11-1) Under irradiation with a mercury UV lamp, chlorine gas was bubbled into a fraction (106 g) obtained in the same manner as in Example 1-2 at 40 to 50 ° C. Then, after purging excess chlorine gas, a crude product was obtained. The crude product was distilled under reduced pressure to obtain a fraction (133 g) of (74 to 76) ° C./(267 to 400) Pa. As a result of analyzing the fraction using gas chromatography analysis and ¹ H-NMR, it was confirmed that the compound (a11-2) was produced.

  A fraction (132 g), antimony pentachloride (17 g) and antimony trifluoride (51 g) were added to a reactor equipped with a refluxer, and the mixture was heated to reflux at 150 ° C. for 4 hours. Next, the crude product obtained by distilling off the inside of the reactor under reduced pressure was washed twice with water, further washed once with a saturated aqueous sodium hydrogen carbonate solution and then dried over magnesium sulfate. The crude product was distilled under reduced pressure to obtain a fraction (110 g) of 62 ° C./2133 Pa. As a result of analyzing the fraction, the production of the compound (a11-1) was confirmed.

¹⁹ F-NMR data (282.7 MHz, solvent: CDCl ₃ , standard: CFCl ₃ ) δ (ppm): 46.20 (1F), −49.5 to −57.5 ppm (2F) of compound (a11-1) ), −78.7 to −79.5 ppm (3F), −107.46 ppm (2F), −117.7 to −118.7 ppm (2F).

[Example 1-4] Production Example of Compound (a11) Dry zinc (28 g) activated with an aqueous hydrochloric acid solution and N, N-dimethylformamide (90 mL) were added to the reactor, and the internal temperature of the reactor was 50 ° C. Dibromoethane (4 g) was gradually added dropwise to the reactor. After completion of the dropwise addition, the internal pressure of the reactor was reduced to 3.6 kPa while maintaining the internal temperature of the reactor at 60 ° C., and the fraction (30 g) obtained in Example 1-3 was dropped into the reactor.

  The distillate was collected until the distillation of the liquid distilling from the reactor stopped. Further, the internal pressure was reduced to 2 kPa, and the liquid distilled was collected together with the distillate to obtain a reaction crude liquid. The reaction crude liquid was washed with water and dried over magnesium sulfate to obtain a reaction liquid. The same reaction was repeated to obtain 315 g of a reaction solution.

  The reaction liquid (80 g) was distilled under reduced pressure using a spinning band distiller (38 to 39) to obtain a fraction (15 g) at 4 ° C./4 kPa. As a result of analyzing the fraction, formation of the compound (a11) was confirmed.

¹⁹ F-NMR (282.7 MHz, solvent: CDCl ₃ , standard: CFCl ₃ ) δ (ppm): 46.07 (1F), −82.08 ppm (3F), −108.12 ppm (2F) of compound (a11) ), -120.89 (2F), -158.02 (2F).

  [Example 2] Production example of compound (a21)

Example 2-1 Production Example of Compound (a21-6) Dry powdered potassium fluoride (58 g) and diglyme (465 g) were added to a cooled flask, and then sultone (1800 g) was further added to the flask. The obtained flask contents and propylene oxide (290 g) were added to an autoclave, and the reaction was carried out with stirring for 5 hours while maintaining the internal temperature at 90 ° C.

After the internal temperature of the autoclave was set to 25 ° C., the contents of the autoclave were collected and filtered to obtain a filtrate. As a result of analyzing the filtrate, it was confirmed that the compound (a21-6) and FSO ₂ CF ₂ CF ₂ OCH (CH ₃ ) CH ₂ OC (O) CF ₂ SO ₂ F were formed. The filtrate was washed with water, dried over magnesium sulfate, and distilled under reduced pressure to obtain a fraction (1200 g) at (61-63) ° C./(17.7-35.5) kPa. As a result of analyzing the fraction, the fraction was about 1: 1 (mass ratio) of the above compound (a21-6) and FSO ₂ CF ₂ CF ₂ OCH (CH ₃ ) CH ₂ OC (O) CF ₂ SO ₂ F. It was confirmed that the mixture contained at a ratio of

¹⁹ F-NMR of fraction (282.7 MHz, solvent: CDCl ₃ , standard: CFCl ₃ ) δ (ppm): 40.6-44.0 ppm (2F), -82.0--85.0 ppm (2F) -103.5 to -104.5 ppm (2F), -111.7 ppm (2F).

[Example 2-2] Production Example of Compound (a21-5) (HFPO) ₃ (4200 g) was added to an autoclave (internal volume 3000 mL, made of stainless steel) and stirred. At the gas outlet of the autoclave, a heat exchanger, a NaF pellet packed bed, and a circulation path arranged in series with a liquid return line for returning the condensed liquid to the autoclave were installed. Further, (HFPO) ₃ in the autoclave was circulated using a bellows pump having a capacity of 300 L / hour to maintain the internal temperature of the autoclave at 10 ° C.

  Fluorine gas diluted to 20% with nitrogen gas (hereinafter referred to as 20% diluted fluorine gas) is continuously supplied from an ejector (stainless steel) installed in the circulation path at a flow rate of 88.5 L / hour and circulated for 1 hour. It was.

  Next, while continuing the supply of 20% diluted fluorine gas, a raw material solution obtained by diluting the mixture (200 g) obtained in Example 2-1 to R-113 (1000 g) was supplied from a raw material supply pipe installed in a circulation path to 85 g / hour. The autoclave contents were continuously withdrawn in order to keep the liquid volume of the autoclave contents constant while continuously feeding at a flow rate of. After supplying the raw material solution, 20% diluted fluorine gas was further supplied at the same flow rate for 16 hours.

Nitrogen gas was blown into the autoclave for 3 hours, and then the content of the autoclave was withdrawn to obtain a reaction solution. As a result of analyzing the reaction solution using ¹⁹ F-NMR, it was confirmed that the compound (a21-5) and FSO ₂ CF ₂ CF ₂ OCF (CF ₃ ) CF ₂ OC (O) CF ₂ CF ₂ SO ₂ F were formed. did.

[Example 2-3] Production example of compound (a21-4) Reaction solution obtained by distilling off (HFPO) ₃ in the reaction solution (1200 g) obtained in the same manner as in Example 2-2, and potassium fluoride (7 g) Was added to a flask equipped with a reflux, and then heated for 3 hours while maintaining the internal temperature at 80 ° C. Next, the internal pressure of the flask was gradually reduced to raise the internal temperature of the flask to obtain a fraction (360 g) of (70 to 82) ° C./(13 to 35) kPa. As a result of analyzing the fraction, it was confirmed that the fraction was a mixture containing the compound (a21-4) and FSO ₂ CF ₂ CF ₂ OCF (CF ₃ ) COF in a ratio of 8: 2 (mass ratio).

[Example 2-4] Production example of compound (a21-3) The fraction (350 g) obtained in Example 2-3 and NaF (130 g) were added to a flask, and CH ₂ (OH) CH ₂ was stirred while the flask was stirred. Br (258 g) was added dropwise. After completion of the dropwise addition, the temperature inside the flask was kept at 25 ° C., and the inside of the flask was further stirred for 3 hours. Next, the filtrate obtained by filtering the contents of the flask was washed with water and dried over magnesium sulfate to obtain a reaction crude liquid (500 g).

  The reaction crude liquid (250 g), potassium hydrogen carbonate (210 g) and acetonitrile (465 g) were added to the flask, and the mixture was stirred at 25 ° C. for 3 hours while stirring. The filtrate obtained by filtering the solution in the flask was poured into excess water, and the lower layer liquid of the two-layer separated liquid obtained was separated. A solution obtained by combining the lower layer solution and the lower layer solution obtained by performing the same reaction twice in total was washed with water, dried over magnesium sulfate, and distilled under reduced pressure to obtain (52 to 55) ° C./(400 to 530). A fraction of Pa (160 g) was obtained. As a result of analyzing the fraction, the production of the compound (a21-3) was confirmed.

¹ H-NMR (300.4 MHz, solvent CDCl ₃ , standard: Si (CH ₃ ) ₄ ) δ (ppm) of compound (a21-3): 4.31 ppm (4H).
¹⁹ F-NMR (282.7 MHz, solvent: CDCl ₃ , standard: CFCl ₃ ) δ (ppm): 45.18 ppm (1F), −79.96 ppm (3F), −82.30 ppm of the compound (a21-3) (2F), -82.65 ppm (2F), -112.31 ppm (2F).

[Example 2-5] Production example of compound (a21-1) Except for using the fraction obtained in Example 2-4, the reaction was carried out in the same manner as in Example 1-3 to give the compound (a21-1). Obtained.
¹⁹ F-NMR (282.7 MHz, solvent: CDCl ₃ , standard: CFCl ₃ ) δ (ppm): 45.65 ppm (1F), −49.8 to −58.1 ppm (2F) of compound (a21-1) -79.1 to -80.0 ppm (3F), -81.5 to -83.2 ppm (4F), -112.2 to -112.8 ppm (2F).

[Example 2-6] Production Example of Compound (a21) The compound (a21) was reacted in the same manner as in Example 1-4 except that the compound (a21-1) obtained in Example 2-5 was used. Obtained.
¹⁹ F-NMR of compound (a21) (282.7 MHz, solvent CDCl ₃ , standard: CFCl ₃ ) δ (ppm): 45.20 ppm (1F), −82.20 ppm (3F), −82.45 ppm (2F) -85.08 ppm (2F), -112.63 ppm (2F), -158.43 ppm (2F).

[Example 3] Production example of polymer (A11-1) Compound (a11) (3.6 g), R-225cb (27 g), and IPP (15 mg) were charged into an autoclave (internal volume 30 mL), and freeze deaeration was performed. Went. Next, the internal temperature of the autoclave was kept at 40 ° C., and TFE was introduced while stirring the autoclave until the internal pressure reached 0.15 MPa. Subsequently, the reaction was carried out for 7 hours while continuously introducing TFE so as to maintain the internal pressure at 0.15 MPa.

  Next, the autoclave was cooled to release the internal pressure, and hexane was immediately charged into the autoclave. The agglomerated autoclave contents were collected and washed three times with hexane, and then vacuum-dried at 80 ° C. for 12 hours to obtain a polymer (hereinafter simply referred to as polymer (A11-1)) (3.4 g). Obtained.

As a result of analyzing the polymer (A11-1) by ¹⁹ F-NMR (standard: hexafluorobenzene) and IR, the ratio of the following monomer unit (A11) to all monomer units is 26.4 mol%, and —CF ₂ The proportion of CF ₂ -units was 73.6 mol%. The molecular weight of each of —SO ₂ F in the polymer (A11-1) was 637.

Example 4 Production Example of Polymer (A11-1N) The polymer (A11-1) was processed into a film having a thickness of 100 μm by a hot press method, and the film was KOH / H ₂ O / DMSO = 30/65/5. It was immersed in an aqueous solution mixed at a ratio of (mass ratio) at 90 ° C. for 17 hours. Next, it was washed with water three times at 25 ° C. and immersed in a 2 mol / L sulfuric acid aqueous solution for 2 hours. Washing with water and sulfuric acid immersion were repeated three times, and further three times with water.

  Subsequently, the film was air-dried at 80 ° C. for 16 hours and further vacuum-dried to obtain a light brown dry film. The softening temperature of the film as measured by dynamic viscoelasticity was 152 ° C. Further, as a result of analyzing the dried film using IR, a spectrum due to the carboxyl group was observed in the film.

  Dry using a four-terminal method in which a dry film (5 mm width) is adhered to a substrate on which electrodes are arranged at intervals of 5 mm under conditions of alternating current (10 kHz, 1 volt) under constant temperature and humidity (80 ° C., 95% RH). The specific resistance of the film (5 mm wide) was measured and found to be 3.3 Ω · cm.

[Example 5] Production example of polymer (A11-1F) The polymer (A11-1) was put into an autoclave (manufactured by Hastelloy), and the atmosphere inside the autoclave was deaerated. Next, fluorine gas diluted to 20% by volume with nitrogen gas was introduced into the autoclave until the internal pressure became 0.3 MPa, and the polymer was subjected to fluorination treatment for 4 hours while maintaining the internal temperature at 180 ° C. A polymer (referred to as A11-1F) was obtained. Coloring was not observed in the film obtained by treating the polymer (A11-1F) using the same method as in Example 4. Moreover, as a result of analyzing a film using IR, absorption of the carboxyl group was not recognized by the film.

[Example 6] Production example of polymer (A11-2) Compound (a11) (3.6 g), R-225cb (27 g) and IPP (15 mg) were charged into an autoclave (internal volume 30 mL), and freeze deaeration was performed. went. Next, the internal temperature of the autoclave was maintained at 40 ° C., and TFE was introduced while stirring the autoclave until the internal pressure reached 0.16 MPa. Subsequently, TFE was continuously introduced so as to maintain the internal pressure at 0.16 MPa, and the reaction was performed for 4 hours.

  Next, the autoclave was cooled to release the internal pressure, and hexane was immediately charged into the autoclave. The agglomerated autoclave contents were collected and washed three times with hexane, and then vacuum dried at 80 ° C. for 12 hours to obtain a polymer (hereinafter simply referred to as polymer (A11-2)) (1.8 g). Got.

As a result of analyzing the polymer (A11-2) by ¹⁹ F-NMR (standard: hexafluorobenzene) and IR, the ratio of the monomer unit (A11) to the total monomer units was 22.2 mol%, and —CF ₂ CF The proportion of ₂ -units was 77.8 mol%. The molecular weight per —SO ₂ F in the polymer (A11-2) was 708.

[Example 7] Production example of polymer (A11-2N) The polymer (A11-2) was processed into a film having a thickness of 100 µm by a hot press method, and the film was KOH / H ₂ O / DMSO = 30/65/5. It was immersed in an aqueous solution mixed at a ratio of (mass ratio) at 90 ° C. for 17 hours. Next, it was washed with water three times at 25 ° C. and then immersed in a 2 mol / L sulfuric acid aqueous solution for 2 hours. Washing with water and sulfuric acid immersion were repeated three times, and further three times with water.

  Subsequently, the film was air-dried at 80 ° C. for 16 hours and then vacuum-dried to obtain a light brown dry film. The softening temperature of the dry film by dynamic viscoelasticity measurement was 148 ° C., and the specific resistance of the dry film measured using the same method as in Example 4 was 3.4 Ω · cm.

[Example 8] Production example of polymer (A11-3) Compound (a11) (6.3 g), R-225cb (8.9 g) and AIBN (1.5 mg) were charged into an autoclave (internal volume 30 mL). Freeze deaeration was performed. Next, the internal temperature of the autoclave was maintained at 70 ° C., and TFE was introduced while stirring the autoclave until the internal pressure reached 0.5 MPa. Subsequently, TFE was continuously introduced so as to maintain the internal pressure at 0.5 MPa, and the reaction was performed for 9.5 hours.

  Next, the autoclave was cooled to release the internal pressure, and hexane was immediately charged into the autoclave. The agglomerated autoclave contents were collected, washed with hexane three times, and then vacuum-dried at 80 ° C. for 12 hours to give a polymer (hereinafter simply referred to as polymer (A11-3)) (3.1 g). Got.

The polymer (A11-3) was analyzed by ¹⁹ F-NMR (standard: hexafluorobenzene) and IR. As a result, the ratio of the monomer unit (A11) to the total monomer units was 33.8 mol%, and —CF ₂ CF The proportion of ₂ -units was 66.2 mol%. The molecular weight per one -SO ₂ F group of the polymer (A11-3) was 554. As a result of measuring the molecular weight of the polymer (A11-3) using GPC (developing solvent: R-225cb, standard sample: polymethyl methacrylate), the weight average molecular weight was 310,000 and the number average molecular weight was 180,000. It was.

[Example 9] Production example of polymer (A11-4) Compound (a11) (7.2 g), R-225cb (10.2 g), AIBN (8.7 mg) were charged into an autoclave (internal volume 30 mL). Freeze deaeration was performed. Next, the internal temperature of the autoclave was maintained at 70 ° C., and TFE was introduced while stirring the autoclave until the internal pressure reached 1.4 MPa. Subsequently, TFE was continuously introduced under the condition that the internal pressure was maintained at 1.4 MPa, and the reaction was performed for 2 hours.

  Next, the autoclave was cooled to release the internal pressure, and hexane was immediately charged into the autoclave. The agglomerated autoclave contents were collected, washed with hexane three times, and then vacuum dried at 80 ° C. for 12 hours to give a polymer (hereinafter simply referred to as polymer (A11-4)) (9.0 g). Got.

The polymer (A11-4) was processed into a film having a thickness of 100 μm by a hot press method. As a result of measuring the surface reflection IR of the film, and the absorption of 1140 cm ^-1 attributable to CF structure forming the absorption and 1,3-dioxolane structure of 1470 cm ^-1 attributable to the -SO ₂ F was confirmed. As a result of comparing the two absorptions and the absorption confirmed by the polymer (A11-1), the monomer unit (A11) was 18 mol% relative to the total monomer units of the polymer (A11-4), and —CF ₂ CF ₂ The proportion of units was 82 mol%. The molecular weight per —SO ₂ F group of the polymer (A11-4) was 814.

[Example 10] Production example of polymer (A11-4N) The polymer (A11-4) was processed into a film having a thickness of 100 µm by a hot press method, and the film was KOH / H ₂ O / DMSO = 30/65/5. It was immersed in an aqueous solution mixed at a ratio of (mass ratio) at 90 ° C. for 17 hours. Next, the film was washed three times with water at 25 ° C. and immersed in a 2 mol / L sulfuric acid aqueous solution for 2 hours. Washing with water and sulfuric acid immersion were repeated three times, and further three times with water. Subsequently, the film was air-dried at 80 ° C. for 16 hours and then vacuum-dried to obtain a dry film. The specific resistance of the dry film measured using the same method as in Example 4 was 5.3 Ω · cm.

[Example 11] Production example of polymer (A21-1) Compound (a21) (4.0 g), R-225cb (9.6 g), AIBN (3.3 mg) were charged into an autoclave (internal volume 30 mL), Freeze deaeration was performed. Next, the internal temperature of the autoclave was maintained at 70 ° C., and TFE was introduced while stirring the autoclave until the internal pressure reached 1.0 MPa. Subsequently, TFE was continuously introduced under the condition that the internal pressure was maintained at 1.0 MPa, and the reaction was performed for 5 hours.

  Next, the autoclave was cooled to release the internal pressure, and hexane was immediately charged into the autoclave. The agglomerated autoclave contents were collected, washed three times with hexane, and then vacuum-dried at 80 ° C. for 12 hours to give a polymer (hereinafter simply referred to as polymer (A21-1)) (1.8 g). Got.

As a result of analyzing the polymer (A21-1) by ¹⁹ F-NMR, the following monomer unit (A21) with respect to all monomer units was 30 mol%, and the ratio of —CF ₂ CF ₂ — units was 70 mol%. . The molecular weight of each of —SO ₂ F in the polymer (A21-1) was 657. As a result of measuring the molecular weight of the polymer (A21-1) using GPC (developing solvent: R-225cb, standard sample: polymethyl methacrylate), the weight average molecular weight was 250,000 and the number average molecular weight was 140,000. .

[Example 12] Production example of polymer (A21-1N) The polymer (A21-1) was processed into a film having a thickness of 100 µm by a hot press method, and the film was KOH / H ₂ O / DMSO = 30/65/5. It was immersed in an aqueous solution mixed at a ratio of (mass ratio) at 90 ° C. for 17 hours. Next, the film was washed three times with water at 25 ° C. and immersed in a 2 mol / L sulfuric acid aqueous solution for 2 hours. Washing with water and sulfuric acid immersion were repeated three times, and further three times with water.

  Subsequently, the film was air-dried at 80 ° C. for 16 hours and then vacuum-dried to obtain a dry film. The softening temperature of the dried film as measured by dynamic viscoelasticity was 125 ° C. The specific resistance of the dry film measured using the same method as in Example 4 was 2.2 Ω · cm.

[Example 13] Production example of polymer (A21-2) Compound (a21) (4.0 g), R-225cb (9.6 g), AIBN (3.3 mg) were charged into an autoclave (internal volume 30 mL). Freeze deaeration was performed. Next, the internal temperature of the autoclave was maintained at 70 ° C., and TFE was introduced while stirring the autoclave until the internal pressure reached 1.2 MPa. Subsequently, TFE was continuously introduced under the condition that the internal pressure was maintained at 1.2 MPa, and the reaction was performed for 3.6 hours.

  Next, the autoclave was cooled to release the internal pressure, and hexane was immediately charged into the autoclave. The agglomerated autoclave contents were recovered, washed with hexane three times, and then vacuum-dried at 80 ° C. for 12 hours to give a polymer (hereinafter simply referred to as polymer (A21-2)) (2.0 g). Got.

As a result of analyzing the polymer (A21-2) by ¹⁹ F-NMR, the monomer unit (A21) was 23 mol% with respect to the total monomer units, and the ratio of —CF ₂ CF ₂ — units was 77 mol%. The molecular weight per —SO ₂ F in the combined (A21-2) was 746.

[Example 14] solid-state polymer type fuel cell of preparation pressure autoclave (Hastelloy C alloy), the molecular weight per one -SO ₂ F are similar to TFE / PSVE copolymer 910 and Example 4 The polymer (1 part) in which —SO ₂ F obtained by the method is converted to —SO ₃ H and ethanol (9 parts) are added to a pressure-resistant autoclave (manufactured by Hastelloy C alloy), and a dispersion (hereinafter, simply referred to as “Solvent C”). The electrolyte solution was obtained.

A dispersion obtained by adding water (126 g) to carbon black powder (20 g) carrying 50% by mass of platinum and applying ultrasonic waves for 10 minutes was added to the electrolyte solution (80 g), and ethanol (54 g) was further added. This was added to obtain a coating solution for preparing the cathode catalyst layer. The coating solution was applied onto an ETFE substrate film and dried to prepare a cathode catalyst layer having a platinum amount of 0.5 mg / cm ² .

Further, 124 g of water was added to carbon black powder (20 g) carrying 53 mass% (platinum / ruthenium ratio = 30/23) of an alloy composed of platinum and ruthenium (platinum / ruthenium ratio = 30/23), and ultrasonic waves were applied. The dispersion obtained over 10 minutes was added to the electrolyte solution (75 g), and ethanol (56 g) was further added to prepare a coating solution for preparing the anode catalyst layer. The coating solution was applied onto an ETFE substrate film and dried to prepare an anode catalyst layer having a platinum amount of 0.35 mg / cm ² . The specific resistance of the water used for the cathode catalyst layer preparation coating solution and the anode catalyst layer preparation coating solution was 18 MΩ · cm, and the TOC was 10 ppb.

  The polymer (A11-1) is processed into a film having an average film thickness of 55 μm by a hot press method and then treated in the same manner as in Example 4 to obtain an acid type film (hereinafter referred to as acid type film (A11)). It was. The polymer (A21-1N) was processed and processed in the same manner to obtain an acid type film (hereinafter referred to as acid type film (A21)).

The acid-type film (A11) is sandwiched between the cathode catalyst layer and the anode catalyst layer and bonded using a hot press method (120 ° C., 2 minutes, 3 MPa) to form a membrane-catalyst layer assembly (electrode area: 25 cm ^2). )

A membrane-electrode assembly was prepared by sandwiching the electrode side of the membrane-catalyst layer assembly between the gas diffusion layer composed of two carbon papers having a layer composed of carbon and polytetrafluoroethylene on one surface. It was incorporated into a power generation cell. Hydrogen gas (75 mL / min) at 0.2 MPa is supplied to the anode side in the power generation cell, and humidified air (178 mL / min) with a dew point of 100 ° C. is supplied to the cathode side. As a result of continuously generating power while maintaining the density at 0.2 A / cm ² , a voltage of 0.73 V was obtained.

  Moreover, as a result of generating electricity using the membrane-catalyst layer assembly obtained by using the same method except that the polymer (A11-1) was changed to the polymer (A21-1), a voltage of 0.73 V was obtained. can get.

The fluoropolymer obtained by chemically treating the polymer of the present invention is a sulfonic acid polymer having a high softening temperature, and maintains a high mechanical strength in a high temperature region. The fluoropolymer of the present invention is useful as a solid polymer electrolyte, particularly as a solid polymer electrolyte for a fuel cell, for example, as a solid polymer electrolyte of a fuel cell operated at a high temperature of 100 ° C. or higher and pressurized in the cell. A fuel cell using the fluoropolymer of the present invention as a solid polymer electrolyte (for example, a membrane-electrode assembly) can be applied to a hydrogen / oxygen type fuel cell and a direct methanol type fuel cell.

Claims (19)

The polymer containing the monomer unit represented by the following Formula (A).

Where R ^F represents a fluorine atom, a C 1-6 perfluoroalkyl group, a C 2-6 carbon-carbon bond-containing perfluoroalkyl group containing an etheric oxygen atom, or —Q ^F SO ₂ F; ^F represents a perfluoroalkylene group having 1 to 6 carbon atoms or a perfluoroalkylene group containing an etheric oxygen atom between carbon-carbon bonds having 2 to 6 carbon atoms. The polymer containing the monomer unit represented by the following Formula (A2) .

However, R ^F2 represents a fluorine atom, a C 1-6 perfluoroalkyl group or —Q ^{F 2} SO ₂ F, and Q ^{F 2} is a perfluoroalkylene containing an etheric oxygen atom between C 2 -C 6 carbon-carbon bonds. Indicates a group.   The polymer according to claim 1 or 2, wherein the number average molecular weight is 5,000 to 5,000,000. The polymer of any one of Claims 1-3 used for manufacture of a solid polymer electrolyte. The manufacturing method of the polymer containing the monomer unit represented by the following Formula (A) characterized by polymerizing the compound represented by the following formula (a).

Where R ^F represents a fluorine atom, a C 1-6 perfluoroalkyl group, a C 2-6 carbon-carbon bond-containing perfluoroalkyl group containing an etheric oxygen atom, or —Q ^F SO ₂ F; ^F represents a perfluoroalkylene group having 1 to 6 carbon atoms or a perfluoroalkylene group containing an etheric oxygen atom between carbon-carbon bonds having 2 to 6 carbon atoms.   The manufacturing method of the polymer containing the monomer unit represented by the following Formula (A2) characterized by polymerizing the compound represented by the following formula (a2).

  However, R ^F2 Is a fluorine atom, a C 1-6 perfluoroalkyl group or -Q ^F2 SO ₂ F and Q ^F2 Represents a perfluoroalkylene group containing an etheric oxygen atom between carbon-carbon bonds having 2 to 6 carbon atoms. It is a manufacturing method of the polymer used for manufacture of a solid polymer electrolyte, Comprising: The manufacturing method of the polymer of Claim 5 or 6. A process for producing a compound represented by the following formula (a), which comprises dehalogenating a compound represented by the following formula (a-1) in the presence of a dehalogenating agent.

However, X < ¹ > and X < ² > show a chlorine atom or a bromine atom each independently, R ^<F > is etheric oxygen between a fluorine atom, a C1-C6 perfluoroalkyl group, and a C2-C6 carbon-carbon bond. shows a perfluoroalkyl group or a -Q F ^SO 2 _F includes atoms, Q ^F is a carbon of 2-6 perfluoroalkylene group carbon atoms or 1 to 6 carbon atoms - perfluoroalkylene group containing an etheric oxygen atom between carbon bond Indicates.   A process for producing a compound represented by the following formula (a2), which comprises dehalogenating a compound represented by the following formula (a-12) in the presence of a dehalogenating agent.

  However, X ¹ And X ² Each independently represents a chlorine atom or a bromine atom, and R ^F2 Is a fluorine atom, a C 1-6 perfluoroalkyl group or -Q ^F2 SO ₂ F and Q ^F2 Represents a perfluoroalkylene group containing an etheric oxygen atom between carbon-carbon bonds having 2 to 6 carbon atoms. It is a manufacturing method of the compound used for manufacture of a solid polymer electrolyte, Comprising: The manufacturing method of the compound of Claim 8 or 9. A compound represented by the following formula (a-1).

However, X < ¹ > and X < ² > show a chlorine atom or a bromine atom each independently, and R ^<F > is ether property between a fluorine atom, a C1-C6 perfluoroalkyl group, and a C2-C6 carbon-carbon bond. A perfluoroalkyl group containing an oxygen atom or —Q ^F SO ₂ F, wherein Q ^F is a perfluoroalkylene group having 1 to 6 carbon atoms or a perfluoroalkylene containing an etheric oxygen atom between carbon and carbon bonds having 2 to 6 carbon atoms Indicates a group.   The compound represented by the following formula (a-12).

  However, X ¹ And X ² Each independently represents a chlorine atom or a bromine atom, and R ^F2 Is a fluorine atom, a C 1-6 perfluoroalkyl group or -Q ^F2 SO ₂ F and Q ^F2 Represents a perfluoroalkylene group containing an etheric oxygen atom between carbon-carbon bonds having 2 to 6 carbon atoms. The compound of Claim 11 or 12 used for manufacture of a solid polymer electrolyte. A compound represented by the following formula (a).

  However, R ^F Is a fluorine atom, a C1-C6 perfluoroalkyl group, a C2-C6 carbon-carbon bond containing an etheric oxygen atom or -Q ^F SO ₂ F and Q ^F Represents a perfluoroalkylene group having 1 to 6 carbon atoms or a perfluoroalkylene group containing an etheric oxygen atom between carbon-carbon bonds having 2 to 6 carbon atoms. A compound represented by the following formula (a2).

However, R ^F2 represents a fluorine atom, a C 1-6 perfluoroalkyl group or —Q ^{F 2} SO ₂ F, and Q ^{F 2} is a perfluoroalkylene containing an etheric oxygen atom between C 2 -C 6 carbon-carbon bonds. Indicates a group. The compound according to claim 14 or 15, which is used for producing a solid polymer electrolyte. A fluoropolymer containing a monomer unit represented by the following formula (B).

However, R ^FB is a fluorine atom, a C 1-6 perfluoroalkyl group, a C 2-6 perfluoroalkyl group containing an etheric oxygen atom between carbon-carbon bonds, or —Q ^F (SO ₂ Y ^— ( SO ₂ R ^f ) _s ) M ⁺ group, Q ^F represents a ^C 1-6 perfluoroalkylene group or a ^C 2-6 carbon-carbon bond-containing perfluoroalkylene group containing an etheric oxygen atom, Y represents an oxygen atom, a nitrogen atom or a carbon atom, R ^f represents a perfluoroalkyl group which may contain an etheric oxygen atom, s corresponds to Y, and 0 when Y is an oxygen atom , 1 when Y is a nitrogen atom, 2 when Y is a carbon atom, M ⁺ is H ⁺ , a monovalent metal cation, or one or more hydrogen atoms are replaced by hydrocarbon groups Have been Also good ammonium.   A fluoropolymer containing a monomer unit represented by the following formula (B2).

  However, R ^F2 Is a fluorine atom, a C 1-6 perfluoroalkyl group or -Q ^F2 SO ₂ F and Q ^F2 Represents a perfluoroalkylene group containing an etheric oxygen atom between a carbon-carbon bond having 2 to 6 carbon atoms, Y represents an oxygen atom, a nitrogen atom or a carbon atom, R ^f Represents a perfluoroalkyl group which may contain an etheric oxygen atom, s corresponds to Y, 0 when Y is an oxygen atom, 1 when Y is a nitrogen atom, and Y is a carbon atom Indicates 2 and M ⁺ Is H ⁺ A monovalent metal cation or ammonium in which one or more hydrogen atoms may be substituted with a hydrocarbon group. A solid polymer electrolyte material comprising the fluoropolymer according to claim 17 or 18.