JPS5910658B2 - Novel fluorinated vinyl ether compound and its production method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel fluorinated vinyl ether compound and a method for producing the same.

More specifically, the present invention relates to a novel fluorinated vinyl ether compound having a functional group that can be derived into a sulfonic acid group and is useful as a raw material for producing a fluorinated cation exchange membrane used as a diaphragm for electrolyzing aqueous halogenated alkali metal solutions. be. Conventionally, fluorinated cation exchange membranes having carboxylic acid groups or sulfonic acid groups with excellent chemical resistance and heat resistance have been known as diaphragms for electrolysis of aqueous solutions of alkali metal halides. Cation exchange membranes having only acid groups have the disadvantage of low current efficiency.

On the other hand, a film having only carboxylic acid groups has a disadvantage that it has a higher electrical resistance than a film having sulfonic acid groups, and that increasing the current density increases the voltage and power consumption. Therefore, in order to overcome these drawbacks, a cation exchange membrane having sulfonic acid groups and carboxylic acid groups is a preferred type of membrane. However, after laminating a membrane copolymer having a carboxylic acid group or a functional group convertible to a carboxylic acid group and a membrane copolymer having a sulfonic acid group or a functional group convertible to a sulfonic acid group, cations In the case of an exchange membrane, it tends to peel off from the bonded part during electrolysis, and it is difficult to use a blend of the above two types of copolymers or a sulfonic acid group or a functional material that can be converted to a sulfonic acid group. In the case of a cation exchange membrane made from a terpolymer of a vinyl monomer having a carboxylic acid group or a vinyl monomer having a functional group that can be converted to a carboxylic acid group and a fluorinated olefin, the current efficiency is It has the disadvantage that the voltage is not high enough and the voltage is high. From this point of view, as a diaphragm for alkali halide monometallic electrolysis, JP-A-52-24
As disclosed in Japanese Patent Application No. 176, the most preferable type of membrane is one in which one side surface layer of a membrane having a sulfonic acid group is chemically treated to form a membrane having a carboxylic acid group on one side surface layer. There are drawbacks such as. In other words, there is a strong need in the industry for a membrane with high ion exchange capacity and high mechanical strength in order to obtain a high concentration of alkali with less power consumption. When producing a copolymer of a fluorinated olefin and a vinyl monomer having a sulfonic acid group or a functional group that can be converted into a sulfonic acid group, which is used to produce a membrane having a carboxylic acid group, a sulfonic acid group or a sulfonic acid group is used. It is necessary to use a vinyl monomer that has a low molecular weight per equivalent of functional group that can be converted into. However, CF2=CFO-FCF2CFO-)-MCF2 which has been used for the above purpose
Among known fluorinated vinyl ether monomers such as CF2SO2FCF3 (m is an integer of 0 to 2), those having the minimum molecular weight of m=0 can be used in the vinylation process as described in Japanese Patent Publication No. 47-2083. A cyclization reaction as shown in the following formula (1) occurs, and this cyclic sulfone is converted into CF2=
In order to convert it into CFOCF2CF2SO2F, many additional reactions are required and it is very difficult to produce it industrially.Depending on the conditions, it may also be cyclized during polymerization and the physical properties of the polymer may deteriorate.

Therefore, m=1 is usually used industrially, but this means that the sulfonic acid type membrane obtained and the chemical treatment disclosed in the above-mentioned Japanese Patent Application Laid-open No. 52-24176, A drawback arises in that the ion exchange capacity of a membrane in which groups are formed on the surface layer of a sulfonic acid type membrane cannot be sufficiently increased. The one with m=2 further amplifies the above disadvantages.
Furthermore, copolymers of fluorinated vinyl monomers that do not have an ether bond and tetrafluoroethylene, such as trifluorovinylsulfonyl fluoride, disclosed in Japanese Patent Publication No. 13392/1982, have the disadvantage of poor film-forming properties. There is.

Furthermore, JP-A-52-28588, JP-A-52-2
3192 and JP-A-52-36589, the general formula: C1 to ClO perfluoroalkyl group; X4 is FlOH. CRl, 0M2 and NR2R3, R1 is C1
~ClO alkyl group, R2 and R3 are H or one of R1, M2 is an alkali metal or quaternary ammonium group; a is an integer of O~3; b is O or 1; c is O~12 Membranes are described that are derived from fluorinated vinyl compounds and polymers of them with fluorinated olefins.

However, the method for producing the fluorinated vinyl compound is not specifically disclosed, nor is the precursor of the compound taught. Moreover, as can be seen from the description in the specification of the publication, the preferred form is X1=F, . X2-
CF3, X3=F or CF3, X4=F. a=O~1,
Although c=1 to 3, examples and preferred representative examples only include conventionally known c=2 and copolymers and membranes produced therefrom. In manufacturing a fluorinated cation exchange membrane as disclosed in JP-A No. 52-24176, the present inventors
Conventionally known FSO2CF2CF2 (0CFCF2) MO
As a result of our earnest efforts to overcome the drawback of not being able to sufficiently increase ion exchange capacity while maintaining physical strength when using CF=CF2 (m is the same as above) as a raw material, we have developed a structure with a specific structure. The inventors have discovered that the objective can be achieved by using a fluorinated vinyl ether compound, and have completed the present invention.

That is, the present invention is based on the general formula: [X is -SR or -SO2R, where R is C1 to ClO
p is an integer of 3 to 5; n is O or 1], and a method for producing the same is provided.

As for the fluorinated vinyl ether compounds having a functional group that can be converted into a sulfonic acid group, such as the fluorinated vinyl ether compounds, there have been only a few examples of fluorinated vinyl ether compounds such as Japanese Patent Publication No. 43-21408,
Specifically, FSO2 (C
F2) l+0CFCF2+MOCF=CF2(1=2,
Only the compounds m-0 to m-2) are disclosed, and the compounds of the present invention, in which 1 is 3 to 5, are not specifically taught.

The fluorinated cation exchange membrane obtained from the copolymer of the fluorinated vinyl ether compound of the present invention and a fluorinated olefin, such as tetrafluoroethylene, can have a sufficiently high ion exchange capacity while maintaining mechanical strength. It has extremely excellent characteristics. Furthermore, the compound of the present invention can be used for the synthesis of various fluorinated compounds used in surfactants, fiber treatment agents, lubricants, agricultural chemicals, etc., especially various fluorinated compounds having a terminal S-containing functional group. Useful as an intermediate.

Compounds of the invention are prepared according to the following equation.

[X,. p. n is the same as above, M is F or 0M', where M' is an alkali metal] From the reaction mechanism, n essentially has a distribution, and those with n=0 and 1 are co-produced.

Acid fluoride 8 can be synthesized, for example, according to the following formula.

Or (R4 is a C1-C, O alkyl group, M3 is H or an alkali metal) If the compound obtained by in the above synthesis step is used instead of R5SCF2CF2CO2CH3, R
4SO2CF2CF2COF is obtained.

Alternatively, the resulting carboxylic acid can be reacted directly or after oxidation with SF4, or with phosphorous pentachloride or thionyl chloride and then with sodium or potassium fluoride, for example according to the following formula (R5 is the same as R4): Possibly R5S(CF2)3C0F or R
5O2S(CF2)3C0F.

Furthermore, for example, according to the following formula (Y is a halogen excluding F), the sulfonyl fluoride group of the obtained carboxylic acid is converted to a sulfide group or a sulfone group by various chemical treatments, and then reacted with SF4, or or R6S by reaction with phosphorus pentachloride or thionyl chloride followed by sodium or potassium fluoride.
(CF2) 4C0F (R6 is the same as R4 and R5) or R
6SO2(CF2)4C0F is given.

Acid fluoride publication is the equation [according to 0, acid fluoride^] and H
It is obtained by reacting FPO in the presence of fluoride ions such as cesium fluoride and potassium fluoride. Further, if necessary, a carboxylic acid salt can be obtained by hydrolyzing the acid fluoride 8 with an alkali. General formula P of the present invention. According to the above equation, the fluorinated vinyl ether compound represented by
, +0CFCF2).

Although it can be obtained by thermally decomposing a compound represented by CFCOM (Xlp.n.M is the same as above), it is preferable to use MF because the reaction is easy. The reaction can be carried out in a substantially anhydrous state under elevated pressure, normal pressure, or reduced pressure, but normal pressure or reduced pressure is usually convenient.

Depending on the reaction type, use an inert gas or liquid, such as nitrogen, helium, carbon dioxide, or argon as the gas, and an aprotic liquid such as polyethers as the diluent at a dilution ratio of 0 to 100 times. It is also possible to do so.

Further, when the terminal group is an acid fluoride group, it is possible and preferable to carry out the reaction in the presence of a metal salt or metal oxide.

In this case, a solid base capable of decomposing the corrosive and toxic COF2 generated, such as sodium carbonate, potassium carbonate, sodium phosphate, potassium phosphate, etc., is preferably used. The reaction temperature is 100-600°C, preferably 100-350°C. If the temperature is too high, side reactions such as decomposition other than vinylation are likely to occur, and if the temperature is too low, the conversion rate of the raw material will decrease. Reaction time is 0.1 seconds to 1
0 hours, preferably 10 seconds to 3 hours. It is desirable to appropriately adopt suitable reaction conditions for the reaction temperature and reaction time, for example, when a high reaction temperature is selected, the reaction time is short, and when a low reaction temperature is selected, the reaction time is lengthened.
Conventionally, when producing a corresponding fluorinated vinyl ether compound (m is the same as above) by thermally decomposing a known acid fluoride having a sulfonyl fluoride group (same as above), when m=O, Due to the occurrence of a cyclization reaction, it has been difficult to produce FSO2(CF2)20CF-CF2 industrially.

However, according to the present invention, the general formula P, . Since a fluorinated acid fluoride represented by (n is the same as above) is used, x is not SO2F and the sizes of the rings are different, so the cyclization reaction does not occur or can be thermally decomposed to a negligible extent. , general formula P. Among the fluorinated vinyl ether compounds represented by (n is the same as above), those of n-0 can be easily produced.

Further, the vinyl ether does not cause deterioration of polymer physical properties due to cyclization reaction during polymerization. The fluorinated vinyl ether compound of the present invention P. (n is the same as above) is preferably p-3 from the viewpoint of ease of manufacture.

On the other hand, when p≧6, manufacturing becomes difficult. Further, X-1SR is preferred, where R is a C1-ClO alkyl group, and among these, a C1-C5 alkyl group is most preferred. On the other hand, it is desirable that the ion exchange capacity of the cation exchange membrane obtained from the copolymer of the fluorinated vinyl ether compound and tetrafluoroethylene is large. is preferred, and n=O is particularly preferred.

By copolymerizing the fluorinated vinyl ether compound of the present invention with a fluorinated olefin, such as tetrafluoroethylene, a copolymer with excellent chemical resistance and heat resistance can be obtained.

By chemically treating the copolymer after film formation, a fluorinated cation exchange membrane having sulfonic acid groups can be obtained. An extremely high-performance fluorinated cation exchange membrane for electrolysis of aqueous solutions of alkali metal halides having carboxylic acid groups is obtained. These cation exchange membranes have the excellent feature of increasing ion exchange capacity while maintaining mechanical strength compared to conventional membranes.

Examples are shown below, but the technical scope of the present invention is not limited thereto.

Reference example 1 (A) Sodium ethyl mercaptide 2501 and dimethyl carbonate 530r in a 31 stainless steel autoclave
After adding 750 r of tetrahydrofuran, the pressure of the reaction system was reduced to 50 to 6011 Hg.

While stirring the reaction system vigorously, tetrafluoroethylene was gradually blown in under reduced pressure while maintaining the temperature at 15°C. As the reaction progressed, the consumption rate of tetrafluoroethylene decreased, and finally, when the pressure of tetrafluoroethylene reached 1 Kf1/CrA, the consumption of tetrafluoroethylene stopped. After the reaction is complete, the reaction mixture contains 98
300y of % sulfuric acid was added to neutralize. The generated sodium sulfate was separated into mouths, and the mouth fluid was used an evaporator to remove tetrahydrofuran, and the residue was distilled and heated at 84°C/30
A fraction 520V of 11 Hg was obtained. The structure of the fraction was determined by elemental analysis, infrared and pigeon spectra to be C2H, SCF2.
It was confirmed to be CF2COOCH3.

IR properties absorption (liquid): 296012930, 2870a! L-1(C,H,-
) B) C2H5SCF2CF2C obtained in (4) above
While heating OOCH3lOOf to 50°C, a 10N aqueous solution of caustic soda was gradually added dropwise, and when the reaction mixture became slightly alkaline, the dropping was stopped and C2H5SCF2CF
It was set as 2CO2Na.

After sufficiently removing methanol produced in the reaction system using an evaporator, concentrated sulfuric acid was added to make the reaction system weakly acidic. From the reaction system separated into two layers, C2H5SCF2CF2CO,H
An organic layer consisting of was separated and thoroughly dried.

C2H5SCF2CF2CO2H8OV and 1,1,2-trichloro-1,202-trifluoroethane 40CC
and sodium fluoride 321 were placed in a stainless steel autoclave, and sulfur tetrafluoride 63y was press-fitted therein.

The reaction was carried out at 80° C. for 4 hours while stirring. After the reaction was completed, the reactor was purged with dry nitrogen, sodium fluoride was separated from the reaction mixture, and the solution was distilled to obtain a 54V fraction of 46° C./100 Hg. The structure of this fraction was determined by elemental analysis, infrared and Hatake spectra to be C2H5SCF2CF2CO.
It was confirmed that F.

IR characteristic absorption (liquid):) C2H obtained in the above (B)
5SCF2CF, COFlOOVl tetraglyme (tetraethylene glycol dimethyl ether) 1207,
and dried CsF75y were charged into a stainless steel 500CC autoclave equipped with a gas inlet.

After being left at room temperature for 16 hours with stirring, the temperature was increased to 30°C.
Hexafluoropropylene oxide (hereinafter referred to as 8P0) 801 was gradually blown into the reactor at a pressure of 165 kg/Cd or less. After blowing in a predetermined amount of HFPO, stirring was continued until the pressure reached a constant level, and after the internal pressure became constant, unreacted ``PO'' was removed. Distill the residue at 84-87℃
Fraction 707 of /10011Hg was obtained.

Its structure was determined by elemental analysis, infrared and light spectra.
It was confirmed that it was C2SCF2CF2CF2OCFCOF.

IR characteristic absorption (liquid): Crystal VVVv\ v engineering z Elemental analysis: C8H5FllO2S i-kai Mumuno 7 A. ? ．． ? ―
--! Reference Example 2 (4) In (B) of Reference Example 1, C2H5SCF2CF2CO,H obtained by treating C2H5SCF2CF2COOCH3 with alkali and concentrated sulfuric acid.
8O7 was mixed with 400ml of a 2:1 (volume ratio) mixed solution of 30% hydrogen peroxide and glacial acetic acid, and heated at 90℃ for 5 minutes while stirring.
Allowed time to react.

Add concentrated sulfuric acid to the reaction mixture to separate two layers, C2H,S
The organic layer consisting of O2CF2CF2CO2H was separated.

Methanol was added to this under acidic conditions and the mixture was reacted at 60° C. for 3 hours, and then the reaction mixture was distilled. 183-186
℃/40mw! Hg fraction 707 was obtained.

The structure of the fraction was confirmed to be C2H5SO2CF2CF2COOCH3 by elemental analysis, infrared and co-spectra.

IR characteristic absorption (liquid): 29601293012870 (1-JMo VL-1(-C
2H5) 1780 cm-1 (-CO,-), 1360
cTn-1 (-SO2-), 1300-1100 cm
-1 (-CF2-) Elemental analysis value: C6H8F4O4S Calculated value: Cl28.6; Hl3.2; Fl3O. 2;S
ll2.7 Actual value: Cl2863: Hl3.6: Fl2
9, 7; Sll2.9l) After sufficiently drying the organic layer consisting of C2H5SO2CF2CF2CO2H obtained in the above (8), the organic layer was dissolved in 1001,1,1,2-trichloro-1,2,2-trifluoroethane. 50CC1
and sodium fluoride 407 were placed in a 500 d autoclave, and 100 t of sulfur tetrafluoride was introduced under pressure and reacted at 80° C. for 6 hours with stirring.

After the reaction was completed, the reaction mixture was purged with dry nitrogen, sodium fluoride was separated from the reaction mixture, and the liquid was distilled.
A fraction 90y of 9-65°C/13mmHg was obtained. The structure of this fraction was confirmed to be C2H5SO2CF2CF2COF by elemental analysis, infrared and Hyota spectra.

IR characteristics absorption (liquid): 296012930, 2870cm-1 (-C2H5)
1880cm-1 (-COF), 1360CfL-1
(-SO2-), 1300-1100 (1-JmoV!-
1 (-CF2-) Elemental analysis value: C5H5F5O3S Calculated value: Cl25. O; H, 2.1; F, 39.6; Sl
l3,3 actual value: C, 25.5; H, 1.8, Fl39
．． 2;Sll3. l) In reference example 1 (0), C2H5SO is substituted for C2H5SCF2CF2COF.
The same operation was performed except that 2CF2CF2COFlOOy was used, and as a result, 50 t of a fraction of 90-95°C/1011Hg was obtained.

Its structure can be determined by elemental analysis, infrared and ? However, depending on the spectrum, C
It was confirmed to be 2H5SO2CF2CF2OCFCOF. IR (liquid): 2960, 2930, 2870 (1-1(-C2H5)
1880C! RL-1 (-COF), 1360C! !
L-1 (-SO2-), 1100-1300cWL-
1 (-0'2-) Elemental analysis: C8H5Fl, O4S Calculated value: Cl23.6; Hll. 2; Fl5l. 5;S
, 7.9 Example 1 A stainless steel tubular reaction vessel with a diameter of 3 cm and a length of 30 cm was filled with Na2cO3lOOcc, and dry N2 was flowed at 250 cc/Mm, and the filled layer was heated from the outside with an electric heater. It was pre-dried by heating to 350°C.

After preliminary drying for 4 hours, drying N2 was set to 50 cc/Wt, and while the temperature of the packed bed part was maintained at 185 to 190°C, Reference Example 1 was prepared.
H5C2SCF2CF, CF2O obtained by the method of
CFCO Fl2Of 30f7/Hr. was fed into the tubular reactor.

The vapor exiting the bottom of the tube was condensed and collected in a dry ice-methanol cooled tube. The liquid composition is distilled to a boiling point of 77-80°C/10011! Kg fraction 70
I got t. Its structure was confirmed to be H5C2SCF2CF2CF2OCF=CF2 by elemental analysis, infrared spectroscopy, and spectroscopy.

IR (liquid): 2960, 2930, 2870C1n-1 (C2H, -
)1840Cr1L-1 (CF2$CFO-), 11
00-1300cf1L-1 (-CF2-) Elemental analysis: C, H, F, OS Calculated value: Cl27.3; Hll, 6; Fl55.5; S
, lO. 4 Actual measurement value: C, 27. l; H, l. 8; Fl5
5. O;SllO. 3 Example 2 As a result of operating in Example 1 using the same conditions as those obtained in Example 2, a fraction 50f having a boiling point of 82 to 86° C./10% Hg was obtained by distillation.

Its structure was determined by elemental analysis, infrared and tortoise spectroscopy.
It was confirmed that H,SO2CF2CF2CF2OCF=CF2. Example 3 After hydrolyzing with the NaOH aqueous solution obtained by the method of Reference Example 1, it was dehydrated.

The solid residue was washed several times with acetone to extract and separate the carboxylic acid Na salt, and then acetone was removed from the extract using an evaporator. The solid material was pulverized and sufficiently dried at 100° C. under reduced pressure to obtain a solid product.

A 500 CC glass round bottom flask was equipped with a stirrer, a heater, and a glass outlet connected to a vacuum line via a dry ice-methanol cooled trap.

Put 1 into this flask and increase the internal pressure to 101! Thermal decomposition was carried out at 200° C. for 2 hours while maintaining HgIIC and stirring.

The liquid condensed in the trap is subjected to precision distillation, and 77-8
18 tons of fraction at 0°C/1001!1Hg were obtained. Its structure was determined by elemental analysis, infrared and tortoise spectra to indicate H5C2S.
It was confirmed that CF2CF2CF2OCF=CF.

Reference example 3 (A) Sodium methyl mercaptide 2801 and dimethyl carbonate 5301 in a 31 stainless steel autoclave
After adding 1000V of tetrahydrofuran, the reaction system was heated to 50~601! The current pressure was reduced.

While stirring the reaction system vigorously, tetrafluoroethylene was gradually blown in under reduced pressure while maintaining the temperature at 10°C. As the reaction progressed, the consumption rate of tetrafluoroethylene decreased, and finally consumption of tetrafluoroethylene stopped when the pressure of tetrafluoroethylene reached 1 kg/CrA. After the reaction was completed and unreacted tetrafluoroethylene was removed, 98% sulfuric acid 380 was added to the reaction mixture.
7 was added to neutralize it. The generated sodium sulfate was separated, and the mouth fluid was used to remove tetrahydrofuran using an evaporator, and the residue was distilled to obtain 660 tons of fraction at 83° C./50 μl Hg. The structure of the fraction was confirmed to be CH3SCF2CF2COOCH3 by elemental analysis, infrared and curse vectors.

IR characteristic absorption (liquid) (8) CH3SCF2CF2CO obtained in (4) above
While heating OCH3lOOf to 50°C, 10N caustic soda aqueous solution was gradually added dropwise, and when the reaction system became slightly alkaline, the dropping was stopped and CH3SCF2CF2C
It was set as O2Na.

After sufficiently removing methanol produced in the reaction system using an evaporator, concentrated sulfuric acid was added to make the reaction system acidic. An organic layer consisting of CH3SCF2CF2l2H was separated from the reaction system separated into two layers, and the organic layer was sufficiently dried. CH3S
CF2CF2CO2H8Of, 40 CC of 1,1,2-trichloro-1,2,2-trifluoroethane, and 32 V of sodium fluoride were placed in a stainless steel autoclave, and 657 mL of sulfur tetrafluoride was introduced under pressure. While stirring, 80
The reaction was carried out at ℃ for 4 hours. After the reaction is complete, purge with dry nitrogen and separate the sodium fluoride from the reaction mixture.
The oral fluid was distilled to obtain 577 fractions at 74-76°C. The structure of the fraction was determined by elemental analysis, infrared and co-spectra.
It was confirmed that it was 3SCF2CF2COF.

(0 CH3SCF2CF2COF obtained in (B) above
1OOt, 577 glyme (tetraethylene glycol dimethyl ether), and 39 l of dry CsF were charged into a stainless steel 500 CC autoclave equipped with a gas inlet. After standing for 16 hours at room temperature with stirring, 1.5k of hexafluoropropylene oxide (hereinafter referred to as HFPO) 1047 was added while maintaining the temperature at 5°C.
It was gradually blown in while keeping the amount below g/CrA. Predetermined amount of H
After the injection of FPO was completed, stirring was continued until the pressure became constant, and after the internal pressure became constant, unreacted HFPO was removed. After separating CsF from the reaction mixture, the oral liquid was distilled and 69
Fraction 65y of ~72°C/10011Hg was obtained. Its structure was confirmed to be CH3SCF2CF2OCFCOF by elemental analysis, infrared and spectroscopy.

m-characteristic absorption (liquid): r/Hr. obtained by the method of Reference Example 3 while maintaining the r/Hr. was fed into the tubular reactor.

The vapor exiting the bottom of the tube was condensed and collected in a trap cooled with dry ice-methanol. The liquid composition is distilled to a boiling point of 8rc/20011! A food fraction of 65V was obtained. Its structure was determined by elemental analysis, infrared and trace spectra.
It was confirmed that H3SCF2CF2CF2OCF=CF2.

IR characteristic absorption (liquid). Elemental analysis value: C6H3F, OS Usage example The vinyl ether monomer obtained in Example 1 was mixed with water as a solvent, ammonium persulfate-sodium bisulfite redox catalyst was used as a catalyst, ammonium perfluorooctanoate was used as an emulsifier, and tetrafluoroethylene was used. It was copolymerized with tetrafluoroethylene under the conditions of a pressure of 15K9/Crli and a polymerization temperature of 50°C.

The obtained copolymer was formed into a film with a thickness of 250μ, and then treated with chlorine gas to remove the SC2H5 group at the end of the side chain.
Changed to sulfonyl chloride group.

This film-like material is hydrolyzed with an alkali, and the exchange capacity is 1.
3meq/Gr. A strong fluorinated cation exchange membrane having sulfonic acid groups was obtained.

In addition, one side of the above membrane-like material having a sulfonyl chloride group was treated with a mixture of 57% hydroiodic acid and glacial acetic acid, then hydrolyzed with an alkali, and then added to a 5% aqueous solution of sodium hypochlorite. By immersion, a tough fluorinated cation exchange membrane having carboxylic acid groups in the surface layer portion of one side of the membrane and sulfonic acid groups in the remaining portion was obtained.

Claims (1)

[Claims] 1 General formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [X is -SR or -SO_2R, provided that R is C_1 to C
A novel fluorinated vinyl ether compound represented by an alkyl group of _1_0, p is an integer of 3 to 5, and n is 0 or 1]. 2. The compound according to claim 1, wherein p is 3. 3. The compound according to claim 1 or 2, wherein R is an alkyl group of C_1 to C_1_0. 4 General formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [M is F or OM', where M' is an alkali metal; X is -SR or -SO_2R, but R is C_1 to C_1_0
an alkyl group; p is an integer of 3 to 5; n is 0 or 1]
A general formula characterized by thermally decomposing the compound represented by in the presence of a metal salt or metal oxide if necessary: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [X, p, n are the same as above] A method for producing a novel fluorinated vinyl ether compound represented by 5. The method according to claim 4, wherein p is 3. 6. The method according to claim 4 or 5, wherein R is an alkyl group of C_1 to C_1_0. 7. The method according to any one of claims 4 to 6, wherein M is F.