WO1998054253A1 - Process for producing fluorine-containing copolymer composition - Google Patents

Abstract

A composition for vulcanizing a fluororubber containing a vulcanizing agent and a vulcanizing assistant homogeneously dispersed therein is efficiently produced by adding a solid solution of an onium compound such as a quaternary ammonium salt or a quaternary phosphonium salt and a polyhydroxyl compound or a salt thereof to an aqueous dispersion of a fluorine-containing copolymer and coagulating a composition comprising the fluorine-containing copolymer and the solid solution to cause separation.

Description

 Specification

 Method for producing fluorinated copolymer composition

 TECHNICAL FIELD-The present invention relates to a method for producing a fluorinated copolymer composition, and more particularly to a method for producing a fluorinated copolymer composition containing a polyhydroxy compound as a vulcanizing component.

 Background art

 A fluorinated elastic copolymer (hereinafter simply referred to as “fluororubber”) obtained from vinylidene fluoride and at least one other fluorinated monomer is a water-soluble initiator and an oil-soluble initiator. It is produced by copolymerizing a monomer with one or both of the above. For example, Japanese Patent Application Laid-Open No. 52-84271 (U.S. Pat. No. 4,141,874) discloses that a water-soluble initiator is used in the first stage of polymerization, A method for producing fluororubber by two-stage polymerization using an oil-soluble initiator is disclosed. In this case, in the second stage polymerization using an oil-soluble initiator, an emulsifier is added to the medium to uniformly disperse the oil-soluble initiator.

 The obtained fluororubber is mixed with a vulcanizing agent (for example, a polyhydroxy compound) and a vulcanization accelerator (for example, a quaternary ammonium salt) to obtain a vulcanizing composition.

 The method of mixing the vulcanizing agent and the vulcanization accelerator with the fluororubber can be roughly classified into a method of adding a vulcanizing agent and a vulcanization accelerator to an aqueous dispersion of the fluororubber and setting the fluororubber. There is a method of taking out by coagulation from the aqueous dispersion, drying, and kneading with a vulcanizing agent and a vulcanization accelerator.

Japanese Patent Application Laid-Open No. 52-73659 (U.S. Pat. No. 4,141,874) discloses an acid acceptor, a polyhydroxy aromatic compound and a specific A fluororubber composition in which a quaternary ammonium compound is compounded and kneaded is disclosed.

 However, kneading has poor workability, and it is difficult to uniformly mix a vulcanizing agent and a vulcanization accelerator with fluororubber. In addition, a large amount of energy is required to mix high viscosity fluoro rubber. Also, quaternary ammonium compounds are deliquescent and absorb moisture in the atmosphere, making them difficult to handle.

 On the other hand, a quaternary ammonium compound and / or a quaternary phosphonium compound as a vulcanization accelerator are added to an aqueous emulsion or aqueous dispersion of a fluororubber, followed by coagulation to obtain a composition for vulcanization of fluororubber. A method for obtaining the product is disclosed in Japanese Patent Publication No. 56-147480.

 According to this method, the fluororubber can be uniformly mixed with the vulcanizing agent and the vulcanization accelerator, which is more efficient than kneading.

 However, since the quaternary ammonium compound is deliquescent as described above, it tends to be taken into the aqueous medium when coagulating with the fluororubber from the aqueous dispersion, and a predetermined amount of the quaternary ammonium compound is used. When attempting to incorporate quaternary ammonium compound into fluororubber, it is necessary to add a predetermined amount or more of a quaternary ammonium compound to the aqueous dispersion, and the amount incorporated into the fluororubber is unstable. Both the fluororubber aqueous dispersion and the fluororubber aqueous emulsion obtained using the oil-soluble initiator contain an emulsifier. However, it has been found that the action of quaternary ammonium compounds is inhibited by emulsifiers.

 It is possible to mix a polyhydroxy aromatic compound and a quaternary phosphonium salt by kneading with the fluororubber produced by the two-step polymerization described above. WO-96 / 1787876 (PCT / JP95 / 2 4 8 5).

However, the action of quaternary phosphonium salts is also inhibited by emulsifiers. It has been known.

 In order to avoid the effects of deliquescent of quaternary ammonium compounds, Japanese Patent Publication No. 57-147475 discloses the use of a solid solution of a quaternary ammonium compound and a polyhydroxy aromatic compound. Kneading with fluororubber is disclosed. However, there is no mention or suggestion of using this solid solution for coagulation with fluororubber.

 Summary of the Invention

 An object of the present invention is to provide a method for efficiently producing a composition for vulcanizing a fluororubber by coagulation.

 Another object of the present invention is to provide a method capable of obtaining a fluororubber composition in which a vulcanizing agent and a vulcanization accelerator are uniformly dispersed in a fluororubber.

 According to the present invention, the above-mentioned object is achieved by adding a solid solution of an ammonia compound and a polyhydroxy compound or a salt thereof to an aqueous dispersion of a fluorine-containing copolymer, and then coagulating as necessary. This is achieved by a process for producing a fluorinated copolymer composition comprising coagulating and separating a composition comprising the fluorinated copolymer and the solid solution by adding an agent.

 In the production method of the present invention, when the aqueous dispersion of the fluorine-containing copolymer contains an emulsifier, the above object is achieved by adding an acid to the water-soluble dispersion before the addition of the onium compound and the polyhydroxy compound or a salt thereof. This is achieved by means for reducing the emulsifying action of the emulsifier.

Further, when the aqueous dispersion of the fluorinated copolymer is acidic, the above-mentioned object is attained in the state of the aqueous dispersion of the fluorinated copolymer having a pH of 7 to 9, and the ionic compound and the polyhydroxy compound are prepared. Alternatively, it can also be achieved by adding a salt thereof. Detailed description of the invention

 The aqueous fluororubber dispersion used in the present invention may be obtained by any of the polymerization methods known in the prior art. In particular, when the method of the present invention is applied to an aqueous dispersion obtained by the two-stage polymerization containing an emulsifier in the aqueous dispersion, the effect of the present invention is remarkable.

 The polyhydroxy compound used as the vulcanizing agent is preferably a polyhydroxy aromatic compound. As the polyhydroxy aromatic compound, any compound known as a vulcanizing agent for fluorine rubber can be used. Preferable examples are 2,2-bis (4-hydroxyphenyl) propane (bisphenol-A), 2,2-bis (4-hydroxyphenyl) perfluoropropane (bispheno-one AF), resonolecin, 1,3, 5—trihydroxybenzene, 1,7 dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6—dihydroxynaphthalene, 4, 4 ′ dihydroxydiphene ^, 4, 4 ′ — Dihydroxystinoleben, 2,6-dihydroxyanthracene, hydroquinone, catechol, 2,2-bis (4-hydroxyphenyl) butane (bisphenol-II), 4,4-bis (4-he Droxyphenyl) valeric acid, 2,2-bis (4-hydroxyphenyl) tetrafluorodichloropropane, 4, 4'-dihydroxydiphenylsulfone, 4,4'-dihydroxy Phenylketone, tri (4-hydroxyphenyl) methane, 3, 3 ', 5, 5'-tetrachlorinated bisphenol A, 3, 3', 5, 5'-tetrabromobisphenol A etc. Is mentioned. These alkaline metal salts or alkaline earth metal salts can also be used.

As the ammonium compound used in the present invention, there are an ammonium compound, a phosphonium compound, an oxonium compound, a sulfonium compound and the like, and a quaternary ammonium salt and a quaternary phosphonium salt are preferable. As the quaternary ammonium salt or the quaternary phosphonium salt, any of those known as vulcanization accelerators for fluorine rubber can be used. Preferred examples are as follows. -Quaternary ammonium salt:

 8-Methyl-1,8-diazabicyclolo [5.4.0] —7-indesedimuchloride, 8-Methyl-1,8-diazabicyclo [5.4.0] —7-didecenyl Muaiodide, 8-methyl-1,8-diazavicic mouth [5.4.0] —7-indesenamide hydroxide, 8-methyl-1,8-diazabicyclo [5.4.0] —7-indesenium-methylsulfate 1,8-ethyl 1,8-diazabicyclo mouth [5.4.0] —7-indesenim bromide, 8-propyl-11,8-diazabicyclo [5.4.0] -7-indesenium promide, 8 — Dodecyl 1,8—Jazavicik mouth [5.4.0] —7—Dindecenylum mouth, 8—Dodecyl1,8—Jazavicik mouth [5.4.0]-7 , 8-eicosyl 1, 8-diazabicyclo [5.4.0]-7-indecenium chloride, 8-te Lakosyl-1,8—diazavicik mouth [5.4.0] —7—indesenimuk mouth lid, 8—Benzyl-1,8—diazavicik mouth [5.4.0] —7—indesenimik mouth lid, 8— Benzyl-1,8-diazavicik mouth [5.4.0] —7-ndenesenidum hydroxide, 8-phenethyl1-1,8—diazavicik mouth [5.4.0] —7-indesenimchlor And 8- (3-phenylpropyl) -1,8-diazabic mouth [5.4.0] —7-indesenimuk lid. Quaternary phosphonium salts:

Tetrabutynolephosphonium chloride, benzinoletriphenylphosphonium chloride, benzyltrimethylphosphonium chloride, benzinoletributylphosphonium chloride and the like. Solid solutions of polyhydroxy compounds and quaternary salts are also known and can be prepared by conventional methods. For example, the solid solution used in the present invention is obtained from the above-mentioned polyhydroxy compound or a salt thereof and a quaternary salt, and the respective components may be made uniform by a conventional method. Easily by mixing and heating the components and melting them until both components liquefy and mix uniformly, or by heating and melting both components with stirring and mixing uniformly, and then cooling. Is obtained.

 The amount of the two components constituting the solid solution is 5 to 400 parts by weight of the quaternary salt with respect to 100 parts by weight of the polyhydroxy compound or the salt thereof, particularly 10 to 1 part by weight. It is preferable to adjust the amount to be 100 parts by weight. If the amount of the quaternary salt is less than the above lower limit, the solid solution generally formed tends to be non-uniform, and it takes extremely long time to vulcanize the fluororubber composition. The solid solution tends to have a high hygroscopicity, and both are not preferred.

 The ratio of the two components constituting the solid solution is preferably set to an appropriate mixing ratio from the beginning.However, a mixture prepared at a predetermined ratio is prepared in advance, and when the solid solution is used, the polyhydroxy compound is used. In addition, the mixing ratio of both components can be adjusted.

 Further, the solid solution may be used in combination of two or more solid solutions, for example, a solid solution of a quaternary ammonium salt and a polyhydroxy compound, and a solid solution of a quaternary phosphonium salt and a polyhydroxy compound. Can be used together.

The solid solution is preferably used as a fine powder in order to be uniformly mixed with the aqueous dispersion. For example, the average particle size is preferably from 10 to 2000 m, more preferably from 10 to 100 μm, especially from 20 to 300 μm. You.

 The content of the solid solution in the vulcanizing composition is usually 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, per 100 parts by weight of the fluororubber. -If the amount of the solid solution is too small, the vulcanization of the fluororubber composition will be insufficient, while if the amount of the solid solution is too large, the rubbery properties of the vulcanized product may be impaired.

 The aqueous dispersion of fluororubber contains an emulsifier due to its manufacturing method, especially when an oil-soluble initiator is used. As mentioned above, emulsifiers may interfere with the action of quaternary ammonium compounds, so add an acid before adding a vulcanizing agent or vulcanization accelerator to reduce the emulsifying effect of the emulsifier. Can be kept. In this case, the vulcanizing agent and vulcanization accelerator need not be in a solid solution. The acid is preferably added in such an amount that the pH of the aqueous dispersion of fluororubber becomes 2 or less.

 The acid may be an inorganic acid or an organic acid.Examples of the former include hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, and examples of the latter include carboxylic acids such as formic acid, acetic acid and oxalic acid. Can be

 Due to the type of compound used as the initiator, the aqueous fluororubber dispersion may exhibit acidity. In this case, before adding the vulcanizing agent or the vulcanization accelerator, the aqueous dispersion may be neutralized by adding a base. Also in this case, the vulcanizing agent ゃ the vulcanization accelerator need not be in a solid solution.

 The base is preferably added in such an amount that the fluororubber also has a pH of 7 to 9 in the aqueous dispersion.

As the base, Amin, ammonia, alkali metal hydroxides, although alkaline earth metal hydroxides can be used, preferably NH ₄ OH, N a ₂ C_〇 _3. In the method of the present invention, the solid solution or the like is added to the aqueous fluororubber dispersion, The precipitated and coagulated fluororubber composition is removed from the aqueous medium by a conventional method.

 Coagulation may be performed by a conventional method. For example, a suitable inorganic or organic acid (for example, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, acetic acid, oxalic acid, etc.) is added to the aqueous dispersion of fluorine rubber to which the solid solution has been added. If desired, an inorganic or organic coagulant such as magnesium chloride, ammonium chloride, potassium chloride, polyalkylamine or a salt thereof can be used in combination.

 To the aqueous fluororubber dispersion, additives which are usually added to the fluororubber composition may be added. Examples of additives that may be added to the aqueous fluororubber dispersion include fillers and reinforcing agents such as carbon black, clay, diatomaceous earth, and talc. If necessary, a plasticizer or a coloring agent can be added.

 Example

 Hereinafter, the present invention will be described specifically with reference to Examples.

 Examples 1 to 3 and Comparative Example 1

 Vinylidenefluoride hexafluoropropylene binary copolymer (vinylidenefluoride: he) synthesized by the method described in Examples of Japanese Patent Application Laid-Open No. 52-84271 is used as the fluororubber. Xafluoropropylene (molar ratio) = 78:22) was used.

 The specific synthesis method is as follows.

 (First stage polymerization)

After charging 15 liters of pure water to a polymerization tank having an internal volume of 36.6 liters, and thoroughly replacing the system with nitrogen gas, vinylidenefluoride hexane mixed propylene mixed monomer (molar ratio) 65:35) 690 g was charged, and the internal temperature was raised to 80 ° C while stirring. Then, add ammonium persulfate 2 A solution in which 6.3 g was dissolved in 10 O ml of pure water was injected with nitrogen gas to start polymerization. At the same time, inject a pre-prepared aqueous solution of ammonium persulfate with a concentration of 207 g / l at a rate of l ml / min commensurate with the decomposition of the ammonium persulfate to keep the concentration of undecomposed ammonium persulfate in the system constant. Kept.

Since the pressure decreases as the polymerization proceeds, the monomer mixture of xafluoropropylene (molar ratio: 78:22) is sequentially injected into vinylidene fluoride, and the reaction pressure is maintained at 8 kgZcm ² G. The reaction was continued, and after 164 minutes, the heating and stirring were stopped, and the monomers in the system were released to stop the reaction.

 The concentration of the aqueous dispersion thus obtained was 21.0% by weight. The copolymer was removed from a part of the aqueous dispersion by a conventional method, and the intrinsic viscosity [7] was measured. 0.90.

 (Second stage polymerization)

 Since the aqueous dispersion obtained by the first-stage polymerization reaction contains undecomposed ammonium persulfate, the aqueous dispersion was treated with activated carbon to decompose the ammonium persulfate.

 3 liters of the aqueous dispersion after treatment and 12 liters of pure water are placed in a polymerization tank with an internal volume of 36.6 liters, and the system is sufficiently replaced with nitrogen gas, and then vinylidene fluoride is mixed with xafluoropropylene. 1200 g of a monomer (molar ratio: 65:35) was charged, and the internal temperature was raised to 70 ° C. while stirring. Next, 15 g of diisopropylpropyl peroxydicarbonate was injected with nitrogen gas to start polymerization.

As the pressure decreases as the polymerization proceeds, the monomer mixture of xafluoropropylene (molar ratio: 78:22) is sequentially injected into vinylidene fluoride, and the reaction pressure is maintained at 14 kgZcm ² G. The reaction was continued, and after 220 minutes, heating and stirring were stopped to release the monomers in the system and stop the reaction. The concentration of the aqueous dispersion thus obtained was 27.3% by weight, and the intrinsic viscosity [] of the copolymer in the aqueous dispersion was 0.89.

 (Example 1)-To 7.3 liters of a 27.3% aqueous dispersion of vinylidenefluoride hexafluoropropylene copolymer, 8.7 g of "solid solution" was added, and stirred. After coagulation with a 3% potassium alum solution, separation was performed, followed by washing and drying to obtain a fluorinated elastic copolymer.

 The “solid solution” used was a mixture of 2 parts by weight of bisphenol AF and 0.35 parts by weight of DBU-B (8-benzyl-1.8-diazabicyclo [5,4,0] -17-indesenium chloride). Then, the mixture was heated to 170 ° C., and both components were melted and mixed uniformly with stirring, and then cooled to prepare.

 (Example 2)

 27.3% aqueous dispersion of vinylidenefluoride hexafluoropropylene copolymer To 1.3 liters, add 7.5 cc of a 10% aqueous hydrochloric acid solution, and stir with bisphenol-AF 7 4 g, DBU—B 1. 3 g was added. Thereafter, coagulation, separation, washing with water and drying were carried out in the same manner as in Example 1 to obtain a fluorinated elastic copolymer.

 (Example 3)

 Vinylidenefluoride 27.3% aqueous dispersion of hexanefluoropropylene copolymer To 1.3 liters, add 6.5 cc of 10% aqueous sodium carbonate solution, and add 7.4 g of bisphenol-AF with stirring. , DBU-B 1.3 g was added. Thereafter, coagulation, separation, washing with water and drying were carried out in the same manner as in Example 1 to obtain a fluorine-containing elastic copolymer.

 (Comparative Example 1)

For comparison, vinylidene fluoride-hexafluoropropylene 2 yuan A 27.3% aqueous solution of the copolymer is coagulated, separated, washed with water and dried by a usual method to obtain a binary copolymer. 2 parts by weight of AF and 0.35 parts by weight of DBU-B were sequentially added and kneaded on a roll at room temperature to obtain a fluorinated elastic copolymer.

 To the copolymers obtained in the respective Examples and Comparative Examples, other additives were sequentially added in the blending amounts (parts by weight) shown in Table 1, kneaded on a roll at room temperature, and left to mature overnight. .

Thereafter, re-kneading was performed, the mixture was placed in a mold, and subjected to primary vulcanization at a temperature of 170 ° C. under a pressure of 50 kg / cm ² for 10 minutes to form a sheet and a P 24 O-ring. Then, the molded product was removed from the mold and subjected to secondary vulcanization in a furnace at a temperature of 230 ° C for 24 hours.

 Tensile strength, elongation and hardness were measured for the vulcanized fluoro rubber sheet thus obtained, while compression set was measured for the P24O-ring. In addition, these measurements were performed by the method according to JIS6301. Table 1 shows the results.

 The dispersibility is as follows: Raw rubber (temperature of 100 ° C for 5 minutes or 120 ° C for 5 minutes) is molded into a 0.1 mm thick film, and vulcanized components are magnified with a 40x magnifying glass. Observe the dispersion of (solid solution, bisphenol AF and / or DBU-B). If the whole looks uniform, it is rated "good", and if it looks mottled, it is rated "bad".

The roll processability is defined as “good” when the compound can be kneaded smoothly without being separated into rolls before and after kneading, and “poor” when not. Comparative Example Example 1 Example 2 Example 3 Fluoro rubber 1 0 0 1 0 0 1 0 0 1 0 0 Solid solution ― 2.3 5 ― ― Bisphenol AF 2 ― 2 2

D B U-B 0.35-0.35 0.35

MT black Black 202 0 200 Magnesium oxide 3 3 3 3 Calcium hydroxide 6 6 6 6 Good dispersibility of vulcanized components Same as left Same as left Same as left

Same as left Same as left Same as left Same as left Vulcanization 170. CX 10 min Same as left Same as left Same as left Sulfur Oven vulcanization 230 ° C X24 hours Same as left Same as left Same as left Normal 100% tensile stress (kg / cm) 6 4 6 9 7 0 6 7 State Tensile strength (kg / cm ") 1 5 2 1 6 5 1 5 8 1 5 5 Object elongation (%) 1 90 2 220 0 210 205 Hardness 7 3 7 4 7 4 7 3 Compression set (%) 1 7.0 0 15. 0 1 6 .1 1 6 .9

(200 ° C x 70 hours)

 (Example 4)

 27.3% aqueous dispersion of vinylidenefluorhexafluoropropylene copolymer, 9.3 g of solid solution was added to 1.3 liters, and coagulated with 3% potassium alum solution under stirring. After separation, washing and drying were performed to obtain a fluorine-containing elastic copolymer.

 The solid solution used was a mixture of 2 parts by weight of bisphenol AF and 0.5 part by weight of BT PPC (benzyltriphenylphosphonium chloride), heated to 170 ° C, and stirred both components. Was melted and mixed uniformly, and then cooled to prepare.

 (Comparative Example 2)

 For comparison, a 27.3% aqueous solution of vinylidenefluoride hexafluoropropylene binary copolymer was coagulated, separated, washed with water and dried by a usual method to obtain a binary copolymer. To 100 parts by weight of this binary copolymer, 2 parts by weight of bisphenol AF and 0.5 part by weight of BTPPC were sequentially added and kneaded on a roll at room temperature to obtain a fluorinated elastic copolymer. I got

The amounts shown in Table 2 (parts by weight) were added to the copolymers obtained in Example 4 and Comparative Example 2. Then, other additives were sequentially added, kneaded on a roll at room temperature, and left overnight to ripen.

 Thereafter, in the same manner as in Examples 1 to 3 and Comparative Example 1, the tensile strength, elongation, and hardness of the vulcanized fluoro rubber sheet were measured. Table 2 shows the results. Table 2

 Comparative Example 2 Example 4

 Fluoro rubber 1 0 0 1 0 0

 Solid solution 2.5 Bisphenol A F 2

 B T P P C 0.5

 MT carbon black 20 20

 Magnesium oxide 3 3

 Calcium hydroxide 6 6

 Good dispersibility of vulcanized components Good Good

 D--processability good good

 Vulcanization Press vulcanization 170 ° C X 10 min

 Oven vulcanization 230 ° C X 24 hours

Always 100% tensile stress (kg / cm ² ) 5 1 5 3

State Tensile strength (kg / cm ² ) 1 6 9 1 7 0

 Object elongation (%) 2 20 2 3 0

 Sex hardness 7 2 7 3

Claims

The scope of the claims  1. To an aqueous dispersion of a fluorinated copolymer, add a solid solution of an onium compound and a polyhydroxy compound or a salt thereof, and then prepare a composition comprising the fluorinated copolymer and the solid solution. A process for producing a fluorine-containing copolymer composition comprising coagulating and separating.  2. The method according to claim 1, wherein the ammonia compound is at least one quaternary salt selected from the group consisting of a quaternary ammonium salt and a quaternary phosphonium salt.  3. The solid solution is a solid solution of a quaternary ammonium salt and a polyhydroxy compound, a solid solution of a quaternary ammonium salt and a salt of a polyhydroxy compound, and a solid solution of a quaternary phosphonium salt and a polyhydroxy compound. 2. The method according to claim 1, wherein the method is a solid solution and at least one solid solution selected from the group consisting of a solid solution of a quaternary phosphonium salt and a salt of a polyhydroxy compound.  4. The method according to claim 1, wherein the solid solution is a solid solution of a quaternary ammonium salt and a polyhydroxy compound.  5. The quaternary ammonium salt is 8—benzyl_1,8—diazabicyclo [5.4.0] -7—indesenium chloride, and the polyhydroxy compound is 2,2— 5. The method according to claim 4, which is bis (4-hydroxyphenyl) perfluoropropane.  6. The method according to claim 1, wherein the solid solution is a solid solution of a quaternary phosphonium salt and a polyhydroxy compound.  7. The method according to claim 6, wherein the quaternary phosphonium salt is benzyltriphenylphosphonium chloride, and the polyhydroxy compound is 2,2-bis (4-hydroxyphenyl) perfluoropropane. Manufacturing method. 8. Quaternary ammonium salt and solid solution of polyhydroxy compound, quaternary At least one selected from the group consisting of a solid solution of an ammonium salt and a salt of a polyhydroxy compound, a solid solution of a quaternary phosphonium salt and a polyhydroxy compound, and a solid solution of a quaternary phosphonium salt and a salt of a polyhydroxy compound. 2. The method according to claim 1, wherein both of the two solid solutions are used.  9. The method according to claim 1, wherein the solid solution has an average particle size of 10 to 200 m.  10. The process according to claim 1, wherein a polyhydroxy compound or a salt thereof is added to the aqueous dispersion after adding the solid solution and before coagulation.  11. The method according to claim 1 or 10, wherein after adding the solid solution, a coagulant is added to the aqueous dispersion for coagulation.  12. The method according to claim 1 or 10, wherein after the solid solution is added, an acid is added to the aqueous dispersion for coagulation.  13. The method according to any one of claims 1, 10, 11 and 12, wherein the composition comprising the fluorinated copolymer and the solid solution is pulverized, separated, and kneaded and dried.  14. Addition of an acid to the aqueous dispersion of the fluorine-containing copolymer containing the emulsifier to reduce the emulsifying action of the emulsifier, followed by addition of the honium compound and the polyhydroxy compound or a salt thereof, to give the fluorine-containing copolymer. A method for producing a fluorinated copolymer composition comprising coagulating, coagulating and separating a composition comprising an onium compound and a polyhydroxy compound or a salt thereof.  15. An ionic compound and a polyhydroxy compound or a salt thereof are added to an aqueous dispersion of a fluorinated copolymer having a pH of 7 to 9, and then the fluorinated copolymer, the honium compound and the polyhydroxy compound are added. Alternatively, a method for producing a fluorine-containing copolymer composition, comprising coagulating and separating a composition comprising a salt thereof.