JPS6115897B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a solution of a fluorine-containing polymer, and more specifically, to a novel solution obtained by dissolving a specific fluorine-containing polymer having a pendant side chain containing a carboxylic acid ester group in a fluorine-containing solvent. be. Conventionally, since fluorine-containing polymers generally have resistance to solvents, solutions of such fluorine-containing polymers are hardly known. In particular, no solvent is known that can dissolve a fluorine-containing polymer in which a large number of fluorine atoms are bonded to the main chain carbon atoms. On the other hand, if a solution of a fluorine-containing polymer as described above can be obtained, various avenues for commercial use will be expanded. For example, a copolymer of a fluorinated olefin such as tetrafluoroethylene and a fluorinated monomer having a carboxylic acid type side chain is a cation exchange resin with excellent oxidation resistance, chlorine resistance, alkali resistance, and heat resistance. Recently, attention has been paid to its use as a membrane for electrolysis in the production of alkali hydroxide and chlorine, a membrane for fuel cells, a membrane for general dialysis, and many other uses. If a solution obtained by dissolving such a fluorine-containing polymer in a solvent could be obtained, the means and operations for forming a film would be extremely easy, and it would be possible to manufacture membranes with arbitrary complex shapes and extremely thin membranes. Various advantages are brought about by making the solution into a solution, such as facilitating the production of diaphragms, and also making it possible to repair pinholes in the diaphragms and appropriately coat the surfaces of objects with fluorine-containing polymers. Fluorine-containing polymers with a high fluorine content bonded to the main chain carbon atoms, such as tetrafluoroethylene polymers, tetrafluoroethylene/hexafluoropropylene copolymers, and tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymers. It is less soluble than hydrocarbon polymers and is insoluble in most solvents. Even in such fluorine-containing polymers, in the case of polymers having highly polar and strongly acidic groups such as sulfonic acid, as seen in Japanese Patent Publication No. 13333/1983, the sulfonic acid group is acid, sulfonamide, etc. It is known that only certain forms such as sulfonate or sulfonate are soluble in highly polar organic solvents. However, in the case of fluorine-containing polymers with carboxylic acid side chains, the only difference is that the side chains are carboxylic acid groups, and they are soluble in organic solvents that well dissolve fluorine-containing polymers with sulfonic acid side chains. Does not show gender. For example, the above-mentioned Special Publication Publication No. 48-13333
Examples of the publication include tetrafluoroethylene/
Perfluoro(3,6-dioxa-4-methyl-
7-octensulfonic acid) (sulfonic acid monomer content of 17 mol% and 19 mol%) can be dissolved in n-butanol and dimethylacetamide when the sulfonic acid group is in the acid form. However, corresponding fluorine-containing polymers with carboxylic acid side chains do not dissolve in these solvents at all. Furthermore, nothing is known about the solubility of such fluorine-containing polymers having carboxylic acid side chains, and there have been no reports that they are even soluble. The present inventor has conducted various studies and studies on means for smoothly and advantageously dissolving a fluorine-containing polymer with a high fluorine content bonded to the main chain carbon atoms as described above, and has discovered the following new knowledge. , has succeeded for the first time in achieving the above object, and this is provided as the present invention. That is, −COOCH ₃ , −COOC ₄ H ₉ , −
COOC ₁₀ H ₂₁ , −COOC ₁₆ H ₃₃ ,

It was discovered that by introducing a pendant side chain containing a carboxylic acid ester group such as [Formula], it becomes possible to dissolve it in a fluorine-containing solvent such as trichlorotrifluoroethane or benzotrifluoride. . Thus, the present invention has been completed based on the above findings, and the present invention has been completed based on the above-mentioned findings. To provide a novel solution of a fluorine-containing polymer, characterized in that the fluorine-containing polymer is dissolved in a fluorine-containing solvent in an amount of about 150 to 313 parts by weight per 100 parts by weight of main chain skeleton carbon atoms. It is. The specific fluorine-containing polymer having pendant side chains containing carboxylic acid ester groups (hereinafter sometimes abbreviated as ester-type fluorine-containing polymer) that is made into a solution in the present invention includes carboxylic acid esters contained in the polymer. Since the concentration of the group is related to solubility, in order to provide sufficient solubility, the concentration (hereinafter referred to as ion exchange capacity) is preferably
is preferably 0.5 to 3.0 milliequivalents, particularly 1.0 to 2.5 milliequivalents/g, in terms of methyl ester, per gram of the ester-type fluorine-containing polymer. Furthermore, the type of carboxylic acid ester group is also related to solubility; generally, the larger the number of carbon atoms in the ester group, the better the solubility even with a low ion exchange capacity. Therefore, the ester type fluorine-containing polymer is a homopolymer of a fluorine-containing vinyl monomer having a carboxylic acid ester group or a functional group convertible to the carboxylic acid ester group, or a combination of such a monomer and a fluorinated olefin. , a copolymer with fluorinated vinyl ether, etc. In the case of a functional group that can be converted into a carboxylic ester group, it is converted to a carboxylic ester group by an appropriate treatment depending on the functional group after polymerization. In addition, functional groups other than carboxylic acid ester groups,
For example, reduction treatment of fluorine-containing polymers having sulfonic acid type functional groups (JP-A-52-24175, 52-
24176, 52-24177, etc.), oxidation treatment (see JP-A-53-132094, 53-132069, etc.) to change the sulfonic acid type functional group to a carboxylic acid type functional group, Furthermore, the ester type fluorine-containing polymer of the present invention can also be obtained by converting it into a carboxylic acid ester group. In the ester type fluorine-containing polymer of the present invention, the content of fluorine atoms bonded to carbon atoms constituting the main chain skeleton is about 150 to 313 parts by weight per 100 parts by weight of the carbon atoms of the main chain skeleton. That is, in the present invention, the carboxylic acid ester group-containing side chain is introduced into a fluorine-containing polymer having a high fluorine content on the main chain carbon, thereby dissolving it in a fluorine-containing solvent. be. The content of fluorine atoms on the main chain skeleton carbon atoms is preferably about 200 to 305 parts by weight per 100 parts by weight of carbon atoms. The fluorine content of the ester type fluorine-containing polymer is 20 to 60.
Approximately % by weight is selected. Preferred examples of the ester type fluorine-containing polymer include those containing the following repeating units (a) and (b). (a) (−CF ₂ −CXX′−) Here, X is -F, -Cl, -H or _-CF3 , X' is X or -( _CF2 ) _n - _CF3 , and m is 1
is an integer of ~5, n is 0 or 1, A is an organic group having 1 to 20 carbon atoms, and Y is -(P・Q・
R)- or -O-(P.Q.R)-. Then, P is −(CF ₂ ) _a −(CXX′) _b −(CF ₂ ) _c −, Q is −(CF ₂ −O−CXX′) _d −, and R is −
(CXX'-O-CF ₂ ) _e -, (P・Q・R) represents arranging at least one of P, Q and R in any order, and a, b, c, d and e
is 0 or an integer from 1 to 6. -(P・Q・R)−
Or as a specific example of -O-(P・Q・R)-, (-
CF ₂ −) _x , −O−(CF ₂ ) _x −, (−O−CF ₂ −CFZ−)
_y , -(O- _CF2 -CFZ) _y- (O- _CF2 -CFR _f- ) _z ,
−(CF ₂ ) _x −(CH ₂ ) _f −, −O−CF ₂ −(CFZ−O−
Examples include _CF2 ) _y- ( _CF2 ) _x- ( _CF2 -O- _CFRf ) _z- . x, y, z, and f are integers of 1 to 6, and Z and R _f are -F or a perfluoroalkyl group having 1 to 6 carbon atoms. The above A may be any organic group having 1 to 20 carbon atoms, and the following examples are usually exemplified. For example, aliphatic hydrocarbon groups having 1 to 20 carbon atoms such as mether group, ethyl group, propyl group, n-butyl group, n-hexyl group, 2-ethylhexyl group, decyl group, and cetyl group; 1H, 1H, 7H-dodecafluoro-1-heptyl group, 1H・1H-pentadecafluorooctyl group, 1H・1H・3H-tetrafluoro-1-propyl group, 1H・1H・11H-eicosafluoro-1-undecyl group, 1・Halogen-containing aliphatic hydrocarbon groups having 1 to 20 carbon atoms such as 1,1-trichloroethyl group, 1,1,2-trichlorobutyl group; cyclohexyl group, 3,4-dimethylcyclohexyl group, 4-chlorocyclohexyl group Alicyclic hydrocarbon groups and halogen-containing alicyclic hydrocarbon groups such as phenyl group, tolyl group, 2,3-dichlorophenyl group, O-fluorophenyl group, m-fluorophenyl group, P- Fluorophenyl group, O-
Chlorophenyl group, m-chlorophenyl group, P-
Phenyl groups and substituted phenyl groups such as chlorophenyl group, 3-trifluoromethylphenyl group, 3-nitrophenyl group; benzyl group such as benzyl group, O-chlorobenzyl group, O-fluorobenzyl group, m-nitrobenzyl group; Substituted benzyl group, etc. In a preferred embodiment of the present invention, the X and
An ester type fluorine-containing polymer in which X' is -F is used. Also, n is 1 and Y is -O-
(P・Q・R)− is practical. Furthermore, -O-(P・Q・R)- is -O-(CF ₂ CFZO) _y
−(CF ₂ ) _x −(CF ₂ OCFR _f ) _z −, and x is 1 to 6
The integers, y and z are 0 or 1, and Z and R _f are -
An ester type fluorine-containing polymer such as CF ₃ is particularly preferred. A is a repeating unit
It is desirable to select according to the content ratio of (b), but
Usually, there is no particular reason to limit it, and it is selected from among the above-mentioned specific examples in consideration of ease of acquisition.
For example, it is preferable that A is an aliphatic hydrocarbon group such as an alkyl group, and also a benzyl group, a phenyl group, a cyclohexyl group, etc. In the case of a fluorine-containing polymer consisting of repeating units (a) and (b), the composition ratio of (a) and (b) is selected so as to have the desired ion exchange capacity. and,
The molecular weight of the ester-type fluorine-containing polymer is expressed as a temperature at which a predetermined volumetric flow rate is exhibited, and the temperature (Tq) at which a volumetric flow rate of 100 mm ³ /sec is expressed in the methyl ester type is preferably 130 to 350°C, particularly 150°C. ~
It is at 230℃. Such ester-type fluorine-containing polymers may contain CF ₂ = CFOB (B
represents a fluorine-containing alkyl group having 1 to 10 carbon atoms), CF ₂ =CF−CF=CF ₂ , CF ₂ =CFO−
(CF ₂ ) _1-4 -OCF=CF ₂ A repeating unit formed from one or more types of monomers may be included. In this specification, the volumetric flow rate refers to an ester-type fluorinated polymer melted and flowed out from an orifice with a diameter of ¹ mm and a length of 2 mm at a constant temperature under a pressure of 30 Kg/cm 2 , and the flow rate of the fluorinated polymer flowing out is mm ³ /sec. It is expressed in units of . In addition, the ion exchange capacity is
It was obtained as follows. That is, the ester groups of the ester-type fluorine-containing polymer are hydrolyzed in an aqueous solution of caustic soda to convert them into -COONa groups, and the Na-type polymer is left in 1N HCl at 60°C for 5 hours to completely hydrogenate.
The mixture was converted into a mold and thoroughly washed with water to ensure that no HCl remained. Then, add 0.5g of this H-type polymer to
It was left standing at room temperature for 2 days in a solution prepared by adding 25 ml of water to 25 ml of 0.1N NaOH. Next, the polymer is taken out and the amount of NaOH in the solution is determined by back titration with 0.1N HCl. The repeating unit (a) as described above in the present invention and
The ester type fluorine-containing polymer containing (b) is
CF ₂ = fluorinated olefin represented by CXX′ and

It can be easily obtained by copolymerization with a polymerizable fluorine-containing carboxylic acid ester monomer represented by the formula (hereinafter simply referred to as ester monomer). In addition, during copolymerization, a methyl ester monomer or an ethyl ester monomer in which A is a methyl group or an ethyl group is used as the ester monomer, and the resulting polymer is treated to form an ester group. can also be converted into a decyl ester group, a butyl ester group, a cetyl ester group, a phenyl ester group, etc. As such a treatment, a method of first converting the ester group into an acid form and then converting the acid form into another ester group, or directly converting it into another ester group by transesterification etc. is adopted as appropriate. can be done. Furthermore, in the present invention,
As mentioned above, a fluorine-containing polymer having a functional group that can be converted into a carboxylic acid ester group can be converted into a carboxylic acid ester group through various reaction treatments such as hydrolysis, neutralization, reduction, and oxidation. The specific ester-type fluorine-containing polymer described above can be obtained. The molar ratio of the repeating units (b) in the ester-type fluorine-containing polymer is selected so as to provide the suitable ion exchange capacity, but is usually 5 to 5.
It is about 30 mol%, preferably about 10 to 25 mol%.
If the ion exchange capacity is too low, such as when the molar ratio of the repeating unit (b) is too low, the solubility will be insufficient and it will be difficult to obtain a practical fluorine-containing solvent solution. On the other hand, if the ion exchange capacity is too large, the molecular weight tends to decrease, resulting in problems such as the strength of the film obtained after scattering the solvent from the solution. The fluorine-containing solvent used for dissolving the ester-type fluorine-containing polymer in the present invention preferably has a fluorine content of 15% by weight or more, and various fluorine-containing organic compounds may be exemplified. For example, 1.
1,2-trichlorotrifluoroethane, 1-bromo-2-fluoroethane, 4-bromo-1.
1,2-trifluorobutene-1,1-chloro-
1,1-dibromotrifluoroethane, heptafluorobutyronitrile, perfluoro-n-heptyl bromide, perfluorooctanonitrile, hexafluoro-2,2,3,3-tetrachlorobutane, 1,2-dichloro- 1,2-difluoroethane, 1-bromo-2-chloro-1,1.
Aliphatic fluorohydrocarbons or aliphatic fluoronitrile compounds such as 2-trifluoroethane; bis(P-fluorophenyl) ether, P-bromophenyl trifluoromethyl ether, n-butyl-1, 1, 2, 2 -tetrafluoroethyl ether, 2-chloro-1,1,2-trifluoroethyl ethyl ether, 2-chloro-1,1,2-
Trifluoromethyl ether, perfluoro-2
-Fluorinated ether compounds such as butyltetrahydrofuran; bis(perfluoroisopropyl)
Ketone, hexafluoroacetylacetone, methylheptafluoropropyl ketone, 1, 1, 3-
Fluorinated ketone compounds such as trichlorotrifluoroacetone and trifluoroacetophenone;
1,2-dichlorohexafluorocyclobutane,
Fluorinated alicyclic compounds such as 1,2-dichlorooctafluorocyclohexene-1; benzotrifluoride, O-bromobenzotrifluoride, 3-bromo-4-chlorobenzotrifluoride, O-bromofluorobenzene, 2- Bromo-4-fluorotoluene, O-chlorobenzotrifluoride, m-chlorobenzotrifluoride, P-chlorobenzotrifluoride, O-chlorofluorobenzene, 3-chloro-4-fluoronitrobenzene, 2,4-dichlorobenzotrifluoride Ride, O-difluorobenzene, 2.4
Examples include fluorinated aromatic compounds such as -difluorotoluene, 1,3-di(trifluoromethyl)benzene, and 1,4-di(trifluoromethyl)benzene. As the fluorine-containing solvent used in the present invention, it is preferable to use one having a boiling point of preferably 250°C or less, since it is practically easily available and the solvent can be easily removed from the solution. . In addition, when considering the ease of preparing and handling the specific fluorine-containing polymer solution, a fluorine-containing solvent having an excessively low boiling point is not desirable. Therefore, it is usually desirable to select a fluorine-containing solvent with a boiling point of about 10 to 250°C, particularly about 20 to 220°C. From this point of view, in the present invention, 1,1,2-trichlorotrifluoroethane, 1,2-dichloro-1,2
-difluoroethane, benzotrifluoride,
and benzotrifluoride methyl, chloro,
Particularly suitable fluorine-containing solvents include those substituted with fluoro, nitro, or trifluoromethyl groups. When dissolving the ester-type fluorine-containing polymer in a fluorine-containing solvent, a predetermined amount of the specific fluorine-containing polymer is added to the solvent, and if necessary,
This is carried out by applying known dissolution promoting means such as heating and stirring. The shape of the ester type fluorine-containing polymer used is lump, film, sheet,
It may be in any form such as fibrous, rod, or pellet, but from the viewpoint of promoting dissolution, it is preferably in the form of fine particles of 20 or more meshes, such as granules or powder. The higher the temperature at the time of dissolution, the more favorable it is for promoting dissolution, and is usually 20°C.
The reaction is carried out at a temperature of -250°C, preferably 30 - 150°C, but can also be carried out under an increased pressure of 1 - 10 atm to promote dissolution. The solution of the ester-type fluorine-containing polymer thus obtained can be used for various purposes, but in particular, it can be used by casting the solution or impregnating a porous material such as asbestos or polytetrafluoroethylene with the solution. It is suitable for making films of arbitrary shapes, sheets, etc. for use in electrolysis, dialysis, fuel cells, etc., and is also suitable for removing damaged parts such as pinholes in films made in this way or other films. Extremely effective for repair. Moreover, by using the solution,
It is also extremely useful for coating the surface of objects such as spacer nets and electrodes. Next, embodiments of the present invention will be described in more detail, but it goes without saying that the present invention is not limited by such explanations. Incidentally, parts in the examples are parts by weight unless otherwise specified. Example 1 Tetrafluoroethylene and CF ₂ =CFO
A polymer powder consisting of a copolymer of (CF ₂ ) ₃ COOCH ₃ and having an ion exchange capacity of 1.40 meq/g and a temperature (Tq) of 230°C exhibiting a volumetric flow rate of 100 mm ³ /sec was mixed with 1 volume of acetic acid/2N hydrochloric acid. The polymer was immersed in a solution of 1 volume at 60° C. for 16 hours to convert the ion exchange groups of the polymer into an acid form and then dried. The acid type polymer
A mixture of 100 parts of decyl alcohol, 600 parts of decyl alcohol, and 2 parts of concentrated sulfuric acid was heated at 110° C. for 12 hours to convert the ion exchange group to a decyl ester type polymer, thereby obtaining 120 parts of a decyl ester type polymer. Add 5 parts of the decyl ester type polymer to 95 parts of P-chlorobenzotrifluoride, heat to 100°C to dissolve, and then heat to 60°C.
A 5% by weight solution of the decyl ester type polymer was obtained. Example 2 Tetrafluoroethylene and CF ₂ =CFO
100 parts of a polymer powder consisting of a copolymer of (CF ₂ ) ₃ COOCH ₃ and having an ion exchange capacity of 1.7 meq/g and a Tq of 215°C was added to a mixture of 600 parts of butanol and 2 parts of concentrated sulfuric acid, and the mixture was heated at 110°C. Polymer 107 whose ion exchange group became butyl ester after heating for 12 hours
I got the department. A polymer solution at 60° C. was obtained by dissolving 3 parts of the butyl ester type polymer in 97 parts of 1,1,2-trifluorotrichloroethane. Example 3 Tetrafluoroethylene and CF ₂ =CFO (CF ₂ )
Composed of a copolymer of COOCH ₃ , with ion exchange capacity
5 parts of polymer powder having 1.90 meq/g and Tq 220°C were added to O-chlorobenzotrifluoride 95
After heating to 110°C to dissolve, the mixture was cooled to 60°C to obtain a polymer solution having a concentration of 5% by weight. Example 4 Tetrafluoroethylene and CF ₂ =CFO
A polymer powder consisting of a copolymer of (CF ₂ ) ₃ COOCH ₃ and having an ion exchange capacity of 1.20 meq/g and a Tq of 230°C was treated in the same manner as in Example 1 to convert the ion exchange group into an acid form, and to 110 parts of a mixture of 100 parts of acid type polymer, 600 parts of cetyl alcohol, and 2 parts of concentrated sulfuric acid.
Heated at ℃ for 12 hours. 125 parts of a polymer in which the ion exchange group was cetyl ester was obtained. 5 parts of the cetyl ester type polymer were added to 95 parts of O-chlorobenzotrifluoride, heated to 100°C to dissolve, and then cooled to 60°C to obtain a 5% by weight solution of the cetyl ester type polymer. Example 5 Tetrafluoroethylene and

It consists of a copolymer of [formula], with an ion exchange capacity of 1.32 milliequivalents/g,
A polymer powder having a Tq of 224° C. was treated in the same manner as in Example 1 to convert the ion exchange group into a decyl ester type. Adding 5 parts of the decyl ester type polymer to 95 parts of O-chlorobenzotrifluoride,
After heating to 110°C to dissolve, the mixture was cooled to 60°C to obtain a 5% by weight solution of the decyl ester type polymer. Example 6 Tetrafluoroethylene and

Consisting of a copolymer of [formula], ion exchange capacity 1.40 meq/g, Tq215
100 parts of polymer powder, 600 parts of phenol
1 part and 2 parts of concentrated sulfuric acid and heated at 110°C for 12 hours to obtain 105 parts of a polymer in which the ion exchange group was of the phenyl ester type. 3 parts of the phenyl ester type polymer is P-chlorobenzotrifluoride97
After heating to 100°C to dissolve, the mixture was cooled to 60°C to obtain a 3% by weight solution of phenyl ester type polymer. Example 7 Tetrafluoroethylene and CF ₂ =CFO
A 200μ thick fluorine-containing polymer film made of a copolymer of (CF ₂ ) ₃ COOCH ₃ and having an ion exchange capacity of 1.50 meq/g was hydrolyzed in an aqueous NaOH solution to form the Na type. Cut a length of 2 into the membrane with a razor.
After making a scratch of mm, the membrane was used to partition an anode and a cathode to form a two-chamber electrolytic cell. A rhodium-coated titanium electrode was used as the anode, and stainless steel was used as the cathode. The distance between the electrodes was 2.2 cm, and the effective area of the membrane was 25 cm ² . Sodium hydroxide was produced by electrolyzing a sodium chloride aqueous solution under the following conditions. A 4N aqueous sodium chloride solution was placed in the anode chamber, and a 12N aqueous sodium hydroxide solution was placed in the cathode chamber.
Add 150ml of 4N sodium chloride solution to the anode chamber.
At this time, a predetermined amount of water was supplied to the cathode chamber so that the concentration of sodium hydroxide obtained therefrom was approximately 14.4N, and the current density of the electrolytic cell was 20N.
Electrolysis was carried out at A/dm ² and a liquid temperature of 85°C, and the catholyte containing 14.4N NaOH obtained as a result of electrolysis contained 1130 ppm of NaCl. Acetic acid 3.
volume, sprinkle with a solution consisting of 1 volume of 2N HCl and incubate the membrane for 3
After being left for a while, it was air-dried and further heated to 60°C. A 5% by weight solution of the decyl ester type polymer of Example 1 was poured into a 2 mm incision made with a razor, and the cut was repaired by air drying. The membrane with the repaired cut was treated in an aqueous NaOH solution, and the ion exchange group in the repaired area was converted into a sodium salt form, which was then used again for electrolysis of an aqueous sodium chloride solution. Voltage between poles
At 3.8 volts, a 14.4N NaOH aqueous solution is obtained from the cathode chamber with a current efficiency of 96%, and it contains
NaCl was 20 ppm. Example 8 Fluoropore, a porous fluororesin film
FP200 (manufactured by Sumitomo Electric Industries, Ltd.) was immersed in a 5% by weight solution of the decyl ester type polymer of Example 1 for 30 minutes, then pulled up and air-dried to obtain a porous film to which the decyl ester type polymer was attached. this film
The ion exchange group of the attached polymer was changed to Na type by treatment with an aqueous NaOH solution. Even after drying, the porous fluororesin material with the Na-type polymer attached easily became wet when immersed in water. On the other hand, Fluoropore FP200 without the above treatment did not get wet with water at all.

Claims (1)

[Scope of Claims] 1. The content of fluorine atoms having a pendant side chain containing a carboxylic acid ester group and bonded to carbon atoms constituting the main chain skeleton is equal to
A solution of a fluorine-containing polymer, characterized in that about 150 to 313 parts by weight of the fluorine-containing polymer per 100 parts by weight is dissolved in a fluorine-containing solvent. 2. The solution of the fluorine-containing polymer according to claim 1, wherein the concentration of carboxylic acid ester groups is 0.5 to 3.0 milliequivalents per gram of the fluorine-containing polymer in terms of methyl ester. 3. The fluorine-containing polymer solution according to claim 1, wherein the fluorine-containing polymer has a fluorine content of 20 to 60% by weight. 4. The solution of the fluorine-containing polymer according to claim 1, wherein the temperature at which the volume flow rate of the fluorine-containing polymer as defined in the text of the fluorine-containing polymer is 100 mm ³ /sec is 130 to 350°C. 5 The fluorine-containing polymer has the following repeating units (a) and
A solution of a fluorine-containing polymer according to claim 1, which contains (b). (a) (−CF ₂ −CXX′−) Here, X is -F, -Cl, -H or _-CF3 , X' is X or -( _CF2 ) _n - _CF3 , and m is 1
is an integer of ~5, n is 0 or 1, A is an organic group having 1 to 20 carbon atoms, and Y is -(P・Q・
R)- or -O-(P・Q・R)-. Then, P is −(CF ₂ ) _a −(CXX′) _b −(CF ₂ ) _c −, Q is −(CF ₂ −O−CXX′) _d −, and R is −
(CXX'-O-CF ₂ ) _e -, (P・Q・R) represents arranging at least one of P, Q and R in any order, and a, b, c, d and e
is 0 or an integer from 1 to 6. 6 A patent claim in which the fluorine-containing polymer is a copolymer of a fluorinated olefin monomer represented by CF ₂ =CXX′ and a fluorine-containing carboxylic acid ester monomer having polymerizability represented by the formula A solution of the fluorine-containing polymer according to item 5. 7. The solution of a fluorine-containing polymer according to claim 5 or 6, wherein the molar ratio of the repeating unit [formula] in the fluorine-containing polymer is 5 to 30 mol%. 8. The solution of a fluorine-containing polymer according to claim 1, wherein the fluorine content of the fluorine-containing solvent is 15% by weight or more. 9. The fluorine-containing polymer solution according to claim 1 or 8, wherein the fluorine-containing solvent has a boiling point of 10 to 250°C. 10 Fluorine-containing polymer concentration in solution is 1% by weight
A solution of a fluorine-containing polymer according to claim 1, which is as follows. 11 Claims 5 and 6, wherein A is selected from aliphatic, alicyclic, or aromatic hydrocarbon groups having 1 to 20 carbon atoms and groups derived therefrom;
Or the solution of the fluorine-containing polymer according to item 7. 12. The solution of a fluorine-containing polymer according to claim 8 or 9, wherein the fluorine-containing solvent is 1,1,2-trichlorotrifluoroethane. 13. The fluorine-containing solvent according to claim 8 or 9, wherein the fluorine-containing solvent is selected from benzotrifluoride and its substituted products with a methyl group, a chloro group, a fluoro group, a nitro group, or a trifluoromethyl group. solution of basic polymers.