Method for recovering water-soluble fluorine-containing polymer

Abstract

Provided is a method for recovering a water-soluble fluorine-containing polymer, wherein a composition containing water and a water-soluble fluorine-containing polymer having a number-average molecular weight of more than 0.1 × 104 is mixed with a cationic polymer to recover the water-soluble fluorine-containing polymer from the composition.

Description

Method for recovering water-soluble fluoropolymer

[0001] The present disclosure relates to a method for recovering a water-soluble fluoropolymer.

[0002] Patent Document 1 describes a method for reducing the amount of fluorine compounds in an aqueous phase, which includes the steps of: a) adding one or more polycationic polymers or precursor polymers thereof to the aqueous phase to at least partially precipitate the fluorine compounds; and b) adding one or more polyanionic polymers to the aqueous phase.

[0003] Patent Document 2 describes a water treatment method characterized by including a removal step of removing a polymer (I) from water containing the polymer (I) containing polymer units (I) based on a monomer represented by the following general formula (I): CX １ X ３ =CX ２ R (-CZ １ Z ２ -A ０ ) ｍ (I) (wherein, X １ and X ３ are each independently F, Cl, H or CF ３ and X ２ is H, F, an alkyl group or a fluorine-containing alkyl group; A ０ is an anionic group; R is a linking group; Z １ and Z ２ are each independently H, F, an alkyl group or a fluorine-containing alkyl group; and m is an integer of 1 or more.

[0004] JP 2011-519976 A International Publication No. 2020 / 218621

[0005] An object of the present disclosure is to provide a recovery method capable of recovering a water-soluble fluoropolymer at a high recovery rate.

[0006] According to the present disclosure, the number average molecular weight is 0.1 × 10 ４The present invention provides a method for recovering a water-soluble fluoropolymer, which comprises mixing a composition containing a water-soluble fluoropolymer exceeding 100% by mass and water with a cationic polymer, and recovering the water-soluble fluoropolymer from the composition.

[0007] According to the present disclosure, it is possible to provide a recovery method that can recover a water-soluble fluoropolymer at a high recovery rate.

[0008] In the present disclosure, the term "organic group" refers to a group containing one or more carbon atoms or a group formed by removing one hydrogen atom from an organic compound. The organic group is preferably an alkyl group which may have one or more substituents.

[0009] In this disclosure, ranges expressed by endpoints include all numbers subsumed within that range (eg, 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98, etc.).

[0010] In this disclosure, the term "at least 1" includes all numbers greater than or equal to 1 (e.g., at least 2, at least 4, at least 6, at least 8, at least 10, at least 25, at least 50, at least 100, etc.).

[0011] Specific embodiments of the present disclosure will be described in detail below, but the present disclosure is not limited to the following embodiments.

[0012] Number average molecular weight is 0.1 x 10 ４ It has been found that when a method using a cationic polymer is selected as a method for recovering a water-soluble fluoropolymer from a composition containing a water-soluble fluoropolymer and water, the water-soluble fluoropolymer can be recovered at a very high recovery rate. Patent Document 2 proposes a water treatment method, but does not specifically consider a treatment method using a cationic polymer.

[0013] That is, in the recovery method of the present disclosure, the number average molecular weight is 0.1 × 10 ４The present invention relates to a method for recovering water-soluble fluoropolymer from a composition containing a water-soluble fluoropolymer and water, the composition being more than 100% pure, by mixing the composition containing the water-soluble fluoropolymer and water with a cationic polymer. By using this method, it is possible to produce an agglomerate containing the water-soluble fluoropolymer and the cationic polymer, and by separating the water and the agglomerate, it is possible to recover the water-soluble fluoropolymer as the agglomerate, and further to recover water of high purity.

[0014] (Cationic Polymer) In the recovery method of the present disclosure, a cationic polymer is used. Examples of the cationic polymer include polyaminoalkyl methacrylate such as dimethylaminoethyl methacrylate, polyethyleneimine, halogenated polydiallylammonium, chitosan, and urea-formalin resin.

[0015] Commercially available cationic polymers include Takifloc C-403, C-408, C-805, C-806, and C-809 manufactured by Taki Chemical Industry Co., Ltd.; Aronfloc EC-509L, C-508, CX-400, C-303, and CX-333 manufactured by MT Aquapolymer Co., Ltd.; Epomin SP-200, HM-2000, P-1000, and P-3000 manufactured by Nippon Shokubai Co., Ltd.; Zeta Ace C-301, C-350, C-932, and P-702 manufactured by Kurita Water Industries, Ltd.; and Unisense FPA100L, KHE104L, KHF11L, and KHP10P manufactured by Senka Corporation.

[0016] As the cationic polymer, among these, at least one selected from the group consisting of polyethyleneimine, poly(diallyldimethylammonium) and salts thereof, poly(trimethylaminoethyl methacrylate) and salts thereof, polydimethylaminoethyl methacrylate, dimethylamine-epichlorohydrin condensates, dicyandiamide-formalin condensates and dicyandiamide-diethylenetriamine condensates is preferred, since it allows the water-soluble fluoropolymer to be recovered at an even higher recovery rate, and polyethyleneimine is more preferred.

[0017] (Mixing Step) In the recovery method of the present disclosure, a composition containing a water-soluble fluoropolymer and water is mixed with a cationic polymer. The composition and the water-soluble fluoropolymer will be described later.

[0018] The content of the water-soluble fluorine-containing polymer in the composition is preferably more than 0% by mass and not more than 1.0% by mass, relative to the mass of the composition. The content of the water-soluble fluorine-containing polymer in the composition is more preferably more than 0.003% by mass, 0.005% by mass or more, 0.010% by mass or more, 0.020% by mass or more, or 0.030% by mass or more, relative to the mass of the composition. The content of the water-soluble fluorine-containing polymer in the composition is 0.5% by mass or less, or 0.2% by mass or less, relative to the mass of the composition.

[0019] The content of the water-soluble fluorine-containing polymer in the composition can be determined by liquid chromatography or NMR measurement. When the water-soluble fluorine-containing polymer contains a carbonyl group, it can also be determined by a Fourier transform infrared spectrometer. Further, the content of the water-soluble fluorine-containing polymer can be determined by a Fourier transform infrared spectrometer as described in WO 2014 / 099453, WO 2010 / 075497, WO 2010 / 075496, WO 2011 / 008381, WO 2009 / 055521, WO 1987 / 007619, JP 61-293476 A, WO 2010 / 075494, WO 2010 / 075359, WO 2012 / 082454, WO 2006 / 119224, WO 2013 / 085864, ...4 / 099454, WO 2014 / 099455, WO 2014 / 099456, WO Measurement methods for each polymer are described in Publication No. 2012 / 082707, WO 2012 / 082703, WO 2012 / 082451, WO 2006 / 135825, WO 2004 / 067588, WO 2009 / 068528, JP 2004-075978, JP 2001-226436, WO 1992 / 017635, WO 2014 / 069165, JP 11-181009, etc. As a method for measuring the content of a water-soluble fluorine-containing polymer, the measurement methods for each polymer described therein can be used.

[0020] The content of the water-soluble fluoropolymer in the composition can be determined quantitatively by a nuclear magnetic resonance apparatus (NMR), liquid chromatography (LC), Fourier transform infrared spectrometer (FT-IR), etc. When the content of the water-soluble fluoropolymer in the composition is a low concentration of less than 0.1% by mass, it is preferable to determine the content by LC.

[0021] As the detector for LC, an ultraviolet absorbance detector (UV), a photodiode array detector (PDA), a parallax refractive index detector (RI), an evaporative light scattering detector (ELSD), a charged aerosol detector (CAD), a mass detector (MS), etc. are preferred, with an ELSD, a CAD, and an MS being more preferred, a CAD and an MS being even more preferred, and an MS being most preferred.

[0022] The separation mode of the column used for quantification is preferably reversed-phase chromatography, normal-phase chromatography, ion-exchange chromatography, size-exclusion chromatography, etc., and more preferably reversed-phase chromatography and size-exclusion chromatography.

[0023] The mobile phase is preferably water or a mixture of water and a water-soluble organic solvent, and the water used may contain a buffer or an ion-pair reagent. The organic solvent is preferably acetonitrile or methanol.

[0024] When the water-soluble fluorine-containing polymer is adsorbed to the metal material of the LC flow path, resulting in a decrease in quantitative performance and sensitivity, the use of an ion pair reagent can improve these performance and sensitivity. Preferred ion pair reagents include triethylamine (TEA) and N,N-diisopropylethylamine (DIPEA), and hexafluoro-2-propanol is preferred as an acidic buffer for adjusting the pH of the mobile phase.

[0025] The amount of the cationic polymer used in the recovery method of the present disclosure is preferably 1 to 10,000% by mass, more preferably 10% by mass or more, even more preferably 30% by mass or more, more preferably 1,000% by mass or less, and even more preferably 500% by mass or less, based on the mass of the water-soluble fluoropolymer.

[0026] The composition and the cationic polymer can be mixed, for example, by adding the cationic polymer to the composition. The cationic polymer may be added once or multiple times.

[0027] The pH of the composition to be mixed with the cationic polymer is preferably 4.0 or higher, more preferably 5.0 or higher, even more preferably 6.0 or higher, and preferably 11.0 or lower, more preferably 9.0 or lower, even more preferably 8.0 or lower.

[0028] The pH of the composition can be measured with a pH meter (for example, Horiba pH meter D-20).

[0029] Before mixing the composition with the cationic polymer, the pH of the composition may be adjusted. The pH can be adjusted by mixing the composition with a pH adjuster. The pH adjuster is not limited, and for example, an acid compound or an alkaline compound can be used. Examples of the acid compound include hydrochloric acid (HCl), nitric acid (HNO ３ ), sulfuric acid (H ２ SO ４ ), phosphoric acid (H ３ P.O. ４ ), and preferably hydrochloric acid (HCl) or nitric acid (HNO ３ The alkali compounds include, for example, hydroxides of alkali metals such as NaOH and KOH; Mg(OH) ２ , Ca(OH) ２ Examples include hydroxides of alkaline earth metals such as those mentioned above; salts with buffering properties such as disodium hydrogen phosphate; ammonia; amines; etc.

[0030] The temperature when mixing the composition and the cationic polymer is preferably 0°C or higher, more preferably 5°C or higher, even more preferably 10°C or higher, and preferably 50°C or lower, more preferably 40°C or lower, even more preferably 30°C or lower.

[0031] The composition and the cationic polymer can be mixed by stirring the mixture containing the composition and the cationic polymer for, for example, 30 seconds to 100 hours.

[0032] In the recovery method of the present disclosure, an inorganic flocculant may be mixed with the composition. The mixing of the composition and the inorganic flocculant may be carried out simultaneously with the mixing of the composition and the cationic polymer, before the mixing of the composition and the cationic polymer, or after the mixing of the composition and the cationic polymer.

[0033] The composition and the inorganic flocculant can be mixed, for example, by adding the inorganic flocculant to the composition. The inorganic flocculant may be added once or multiple times. Alternatively, the inorganic flocculant and the cationic polymer may be added alternately.

[0034] Examples of inorganic flocculants include metal salts, and commercially available products may be used. ２＋ , Ca ２＋ Seawater containing the above, and low molecular weight cationic polymer flocculants can also be used.

[0035] The inorganic flocculant is preferably a metal salt, more preferably a salt of a divalent to hexavalent metal, and even more preferably a salt of a trivalent to hexavalent metal. The metal element constituting the metal salt is preferably at least one selected from the group consisting of Fe, Al, and Ca, more preferably at least one selected from the group consisting of Fe and Al, and even more preferably Al. The counter ion of the metal element constituting the metal salt is preferably at least one selected from the group consisting of sulfate ions, hydroxide ions, fluoride ions, nitrate ions, and chloride ions, more preferably at least one selected from the group consisting of sulfate ions and chloride ions, and even more preferably sulfate ions.

[0036] The inorganic flocculant is preferably at least one selected from the group consisting of iron salts and aluminum salts, more preferably at least one selected from the group consisting of ferric chloride, aluminum sulfate, and polyaluminum chloride, even more preferably at least one selected from the group consisting of aluminum sulfate and polyaluminum chloride, and even more preferably aluminum sulfate.

[0037] The amount of the inorganic flocculant used in the recovery method of the present disclosure is preferably 0.1 to 1000% by mass, more preferably 1.0% by mass or more, even more preferably 10% by mass or more, still more preferably 30% by mass or more, more preferably 300% by mass or less, and still more preferably 100% by mass or less, relative to the mass of the water-soluble fluoropolymer.

[0038] In the recovery method of the present disclosure, in addition to the cationic polymer, at least one selected from the group consisting of anionic polymers, nonionic polymers and amphoteric polymers may be mixed with the composition. By using these polymers in addition to the cationic polymer, the flocculants containing the water-soluble fluoropolymer can be produced more smoothly, and the water-soluble fluoropolymer can be recovered at a higher recovery rate.

[0039] The composition may be mixed with at least one polymer selected from the group consisting of an anionic polymer, a nonionic polymer, and an amphoteric polymer simultaneously with the cationic polymer, before the composition is mixed with the cationic polymer, or after the composition is mixed with the cationic polymer. In particular, it is preferred to mix the composition with the cationic polymer and then mix at least one polymer selected from the group consisting of an anionic polymer, a nonionic polymer, and an amphoteric polymer with the composition.

[0040] The weight average molecular weight of the anionic polymer, nonionic polymer and amphoteric polymer is preferably 100,000 or more, more preferably 500,000 or more, and even more preferably 1,000,000 or more.

[0041] The composition can be mixed with at least one polymer selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers by, for example, adding at least one of these polymers to the composition. The at least one polymer may be added once or multiple times. Alternatively, at least one polymer selected from the group consisting of nonionic polymers and amphoteric polymers and a cationic polymer may be added alternately.

[0042] Examples of anionic polymers include polyacrylamide polymer flocculants such as sodium polyacrylate, partially hydrolyzed polyacrylamide, partially sulfomethylated polyacrylamide, and poly(2-acrylamide)-2-methylpropane sulfate.

[0043] Commercially available anionic polymers include Floclan A1210 manufactured by Katayama Nalco Corporation; Takifloc A-102, A-103, A-177T, A-108T, A-142, and A-50 manufactured by Taki Chemical Co., Ltd.; Acofloc A-95, A-110, and A-150 manufactured by MT Aquapolymer Co., Ltd.; Sumifloc FA-40 and FA-50 manufactured by MT Aquapolymer Co., Ltd.; Diafloc AP199, Ap120C, Ap784, and DF732B manufactured by Mitsubishi Chemical Corporation; and Waterfloc LA-912M, A-52M, and A-71 manufactured by Technica LLC.

[0044] The amount of the anionic polymer to be used in the recovery method of the present disclosure is preferably 0.001 to 50% by mass, more preferably 0.004% by mass or more, even more preferably 0.010% by mass or more, more preferably 30% by mass or less, and even more preferably 20% by mass or less, relative to the mass of the water-soluble fluoropolymer.

[0045] Examples of nonionic polymers include polymer flocculants such as polyacrylamide and polyethylene oxide.

[0046] Commercially available nonionic polymers include Acoflock N-100, N-102, and N-104 manufactured by MT Aquapolymer Co., Ltd., Orflock ON-1H, ON-2, ON-3, and N-1 manufactured by Organo Corporation, and Waterflock L N-52B manufactured by Technica Co., Ltd.

[0047] The amount of the nonionic polymer to be used in the recovery method of the present disclosure is preferably 0.001 to 50% by mass, more preferably 0.004% by mass or more, even more preferably 0.010% by mass or more, more preferably 30% by mass or less, and even more preferably 20% by mass or less, relative to the mass of the water-soluble fluoropolymer.

[0048] The amphoteric polymer may be a commercially available polymer as an amphoteric polymer flocculant, such as a copolymer of acrylamide, aminoalkyl methacrylate, and sodium acrylate.

[0049] Commercially available amphoteric polymers include Takiflock MC-601, MC-602, and MC-603 manufactured by Taki Chemical Industry Co., Ltd.; Diaflock KA003 and KA606A manufactured by Mitsubishi Chemical Corporation; and the like.

[0050] The amount of the amphoteric polymer to be used in the recovery method of the present disclosure is preferably 0.001 to 50% by mass, more preferably 0.004% by mass or more, even more preferably 0.010% by mass or more, more preferably 30% by mass or less, and even more preferably 20% by mass or less, relative to the mass of the water-soluble fluoropolymer.

[0051] In one embodiment of the recovery method of the present disclosure, the water-soluble fluoropolymer can be recovered as a flocculate by: mixing a composition containing a water-soluble fluoropolymer and water with an inorganic flocculant; mixing a composition containing a water-soluble fluoropolymer, water and an inorganic flocculant with a cationic polymer; mixing a composition containing a water-soluble fluoropolymer, water, an inorganic flocculant and a cationic polymer with at least one selected from the group consisting of an anionic polymer, a nonionic polymer and an amphoteric polymer; generating a flocculate containing the water-soluble fluoropolymer, the inorganic flocculant, the cationic polymer and at least one selected from the group consisting of an anionic polymer, a nonionic polymer and an amphoteric polymer; and separating the water from the flocculate.

[0052] In the above embodiment, the aggregates formed in each step may be appropriately separated from water and recovered. In the above embodiment, the pH of the composition may be appropriately adjusted in each step. Furthermore, each step may be performed in a batch or continuous manner.

[0053] In the recovery method of the present disclosure, the composition is mixed with a cationic polymer to produce an aggregate containing the water-soluble fluoropolymer and the cationic polymer, and the water and the aggregate are separated, whereby the water-soluble fluoropolymer can be recovered as the aggregate.

[0054] The separation of water and the coagulates can be carried out by a known method, such as filtering a mixture containing water and the coagulates, applying centrifugal force to a mixture containing water and the coagulates, or allowing a mixture containing water and the coagulates to stand to precipitate the coagulates.

[0055] By using the recovery method of the present disclosure, it is possible to recover 95.0% by mass or more of the water-soluble fluoropolymer contained in the composition. The recovery rate of the water-soluble fluoropolymer is preferably 99.0% by mass or more, more preferably 99.5% by mass or more.

[0056] Furthermore, by using the recovery method of the present disclosure, high-purity water can also be recovered. The content of the water-soluble fluoropolymer contained in the recovered water is 30 ppm by mass or less, more preferably 10 ppm by mass or less, and even more preferably less than 1 ppm by mass, based on the water. The content of the water-soluble fluoropolymer contained in the water is determined by the same measuring method as for the content of the water-soluble fluoropolymer in the composition.

[0057] (Composition containing water-soluble fluoropolymer and water) The composition to be subjected to the recovery method of the present disclosure contains a water-soluble fluoropolymer and water. The composition to be subjected to the recovery method of the present disclosure is usually an aqueous solution in which the water-soluble fluoropolymer is dissolved in water, but it may also be a dispersion in which a part of the components is dispersed in water.

[0058] The composition to be subjected to the recovery method of the present disclosure may contain components other than the water-soluble fluoropolymer and water. The other components include a water-insoluble fluoropolymer, a fluorine-free polymer, a compound having a molecular weight of 1,000 or less, etc.

[0059] Examples of compounds having a molecular weight of 1,000 or less include fluorine compounds such as fluorine-containing surfactants and fluorine-containing monomers, hydrocarbon surfactants, organic solvents, monomers, polymerization initiators, chain transfer agents, and coagulants.

[0060] The content of other components is preferably 1.0 mass% or less, more preferably 0.5 mass% or less, and even more preferably 0.2 mass% or less, relative to the composition, and the lower limit is not particularly limited and may be 0 mass%.

[0061] The composition to be subjected to the recovery method of the present disclosure may contain a polymer other than the water-soluble fluoropolymer. The other polymer may be water-soluble or water-insoluble, and typically has no ionic groups at all or a limited number of ionic groups that result in an ion-exchange rate of more than about 100. The ion-exchange rate of the other polymer is preferably more than 53, more preferably 100 or more, even more preferably 1000 or more, particularly preferably 2000 or more, and particularly preferably 5000 or more.

[0062] Other polymers include fluororesins and fluororubbers.

[0063] Examples of fluororesins include polytetrafluoroethylene (PTFE); copolymers of tetrafluoroethylene (TFE) and another monomer copolymerizable with TFE (fluorine-containing monomers such as vinylidene fluoride, hexafluoropropylene, chlorotrifluoroethylene, and perfluoro(alkyl vinyl ether), hydrocarbon olefins such as ethylene, propylene, and isobutene, and alkyl vinyl ethers) (for example, tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (PFA), and ethylene-tetrafluoroethylene copolymer (ETFE)); polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and ethylene-chlorotrifluoroethylene (ECTFE).

[0064] Examples of fluororubbers include vinylidene fluoride rubbers such as vinylidene fluoride-hexafluoropropylene copolymers, and perfluoroelastomers such as tetrafluoroethylene-propylene rubber and tetrafluoroethylene-perfluoromethylvinyl ether rubber.

[0065] The composition subjected to the recovery method of the present disclosure may be, for example, wastewater generated in industrial production. That is, the composition subjected to the recovery method of the present disclosure may be wastewater. The composition subjected to the recovery method of the present disclosure may be a composition generated in a polymer production process. The composition subjected to the recovery method of the present disclosure may be a composition derived from raw materials used in a polymerization process. The polymerization process may be a process of polymerizing a monomer in the presence of a water-soluble fluoropolymer and water.

[0066] The composition produced in the polymer production process may include not only the composition produced in the polymerization process in which one or more monomers are polymerized, but also the composition produced in the pretreatment process before the polymerization process (e.g., the process of preparing an emulsifier at a predetermined concentration) and the composition produced in the posttreatment process after the polymerization process (e.g., the process of concentrating an aqueous dispersion, the solid-liquid separation process, the coagulation process, the washing process, the dehydration process, the drying process, the heat treatment process, etc.). The composition produced in the polymerization process may also include an aqueous solution, a dispersion, a liquid obtained by liquefying a gas, etc. Furthermore, the composition produced in the polymerization process may include not only the composition produced directly in the polymerization process, but also a composition obtained by treating the composition produced directly in the polymerization process by a method such as filtration, distillation, concentration, or dilution.

[0067] Examples of the monomer include tetrafluoroethylene (TFE), hexafluoropropylene (HFP), chlorotrifluoroethylene (CTFE), vinyl fluoride, vinylidene fluoride (VDF), trifluoroethylene, fluoroalkyl vinyl ether, fluoroalkyl ethylene, fluoroalkyl allyl ether, trifluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutene, hexafluoroisobutene, and fluorocarbons represented by the general formula (100): CHX １０１ =CX １０２ Rf １０１ (In the formula, X １０１ and X １０２ is H on one side and F on the other side, and Rf １０１ is a straight-chain or branched fluoroalkyl group having 1 to 12 carbon atoms), fluorinated vinyl heterocyclic compounds, and monomers that provide crosslinking sites.

[0068] Examples of the fluoroalkyl vinyl ether include those represented by the general formula (110): CF ２ =CF-ORf １１１ (wherein, Rf １１１ represents a perfluoroorganic group.) A fluoromonomer represented by general formula (120): CF ２ =CF-OCH ２ -Rf １２１ (wherein, Rf １２１is a perfluoroalkyl group having 1 to 5 carbon atoms), a fluoromonomer represented by the general formula (130): CF ２ = CFOCF ２ ORf １３１ (wherein, Rf １３１ is a linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, a cyclic perfluoroalkyl group having 5 to 6 carbon atoms, or a linear or branched perfluorooxyalkyl group having 2 to 6 carbon atoms and containing 1 to 3 oxygen atoms.) Fluoromonomers represented by general formula (140): CF ２ = CFO (CF ２ CF (Y １４１ ) O) ｍ (CF ２ ) ｎ F (wherein, Y １４１ represents a fluorine atom or a trifluoromethyl group, m is an integer of 1 to 4, and n is an integer of 1 to 4.) and a fluoromonomer represented by the general formula (150): CF ２ =CF-O-(CF ２ CFY １５１ -O) ｎ -(CFY １５２ ) ｍ -A １５１ (In the formula, Y １５１ represents a fluorine atom, a chlorine atom, -SO ２ It represents a F group or a perfluoroalkyl group. The perfluoroalkyl group is an etheric oxygen and -SO ２ The group n may contain an F group. n represents an integer of 0 to 3. １５１ may be the same or different. １５２ represents a fluorine atom, a chlorine atom, or —SO ２ represents an F group, and m represents an integer of 1 to 5. １５２ may be the same or different. １５１ is -SO ２ X １５１ , -COZ １５１ or -POZ １５２ Z １５３ represents. １５１ is F, Cl, Br, I, -OR １５１ or -NR １５２ R １５３ Represents Z.１５１ , Z １５２ and Z １５３ are the same or different and represent -NR １５４ R １５５ Or -OR １５６ Represents R １５１ , R １５２ , R １５３ , R １５４ , R １５５ and R １５６ are the same or different and represent H, ammonium, an alkali metal, an alkyl group which may contain a fluorine atom, an aryl group, or a sulfonyl-containing group.

[0069] (Water-soluble fluoropolymer) In the recovery method of the present disclosure, a water-soluble fluoropolymer having a number average molecular weight of 0.1 × 10 ４ The water-soluble fluoropolymer is recovered from a composition containing a water-soluble fluoropolymer having a number average molecular weight exceeding 1000 kJ / kg and water. The recovery method of the present disclosure is intended to recover a water-soluble fluoropolymer having a relatively high molecular weight. It has now been found that a water-soluble fluoropolymer having a number average molecular weight that is too low cannot be recovered at a high recovery rate even when the recovery method of the present disclosure is used. One of the features of the recovery method of the present disclosure is that a cationic polymer is used to recover a water-soluble fluoropolymer having a relatively high molecular weight.

[0070] The term "water-soluble" means the property of being easily dissolved or dispersed in an aqueous medium. The particle size of a water-soluble fluoropolymer cannot be measured by dynamic light scattering (DLS), for example, or the particle size is 10 nm or less.

[0071] The water-soluble fluorine-containing polymer can be a water-soluble fluorine-containing polymer in which the proportion of hydrogen atoms bonded to carbon atoms substituted with fluorine atoms is 50% or more. The "proportion of hydrogen atoms bonded to carbon atoms substituted with fluorine atoms" is calculated as the proportion of the number of fluorine atoms to the total number of hydrogen atoms bonded to carbon atoms and halogen atoms (including fluorine atoms) bonded to carbon atoms.

[0072] The number average molecular weight of the water-soluble fluorine-containing polymer is 0.1 × 10 ４The number average molecular weight of the water-soluble fluoropolymer is preferably 0.2 × 10 or more, since this allows the water-soluble fluoropolymer to be recovered at a higher recovery rate. ４ Above, 0.3 x 10 ４ That's it, 0.4 x 10 ４ That's it, 0.5 x 10 ４ That's it, 1.0 x 10 ４ That's it, 3.0 x 10 ４ or more, or 3.1 x 10 ４ The number average molecular weight of the water-soluble fluorine-containing polymer is preferably 75.0×10 or more. ４ Below, 50.0 x 10 ４ Below, 40.0 x 10 ４ Below, 30.0 x 10 ４ or less, or 20.0 x 10 ４ It is preferable that:

[0073] The weight average molecular weight of the water-soluble fluorine-containing polymer is 0.2 × 10 ４ That's it, 0.4 x 10 ４ That's it, 0.6 x 10 ４ That's it, 0.8 x 10 ４ That's it, 1.0 x 10 ４ That's it, 2.0 x 10 ４ That's it, 5.0 x 10 ４ That's it, 10.0 x 10 ４ That's it, 15.0 x 10 ４ That's it, 20.0 x 10 ４ or more, or 25.0 x 10 ４ The weight average molecular weight of the water-soluble fluorine-containing polymer is preferably 150.0×10 or more. ４ Below, 100.0 x 10 ４ Below, 60.0 x 10 ４ Below, 50.0 x 10 ４ or less, or 40.0 x 10 ４ It is preferable that:

[0074] The number-average molecular weight and weight-average molecular weight of the water-soluble fluoropolymer are values ​​calculated by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard. When measurement by GPC is not possible, the number-average molecular weight of the water-soluble fluoropolymer can be determined from the correlation between the number-average molecular weight calculated from the number of terminal groups obtained by NMR, FT-IR, etc. and the melt flow rate. The melt flow rate can be measured in accordance with JIS K 7210.

[0075] The water-soluble fluorine-containing polymer preferably has an ionic group. The ionic group of the water-soluble fluorine-containing polymer is preferably an anionic group, and the anionic group (A ０ ) are preferably mentioned.

[0076] The water-soluble fluoropolymer preferably has an ion exchange ratio (IXR) of 53 or less. IXR is defined as the number of carbon atoms in the polymer backbone relative to the ionic group. Precursor groups that become ionic upon hydrolysis (e.g., —SO ２ F) is not considered an ionizable group for purposes of determining IXR.

[0077] The IXR of the water-soluble fluoropolymer is preferably 0.5 or more, 1 or more, 3 or more, 4 or more, 5 or more, or 8 or more. The IXR of the water-soluble fluoropolymer is preferably 43 or less, 33 or less, or 23 or less.

[0078] The ion exchange capacity of the water-soluble fluoropolymer is preferably 0.80 meq / g or more, 1.50 meq / g or more, 1.75 meq / g or more, 2.00 meq / g or more, 2.20 meq / g or more, more than 2.20 meq / g, 2.50 meq / g or more, 2.60 meq / g or more, 3.00 meq / g or more, or 3.50 meq / g or more. The ion exchange capacity is the content of ionic groups (anionic groups) in the water-soluble fluoropolymer, and can be calculated from the composition of the water-soluble fluoropolymer.

[0079] In water-soluble fluoropolymers, the ionic (anionic) groups are typically distributed along the polymer backbone. The water-soluble fluoropolymer comprises a polymer backbone with recurring side chains attached to the backbone, which preferably carry ionic groups.

[0080] The water-soluble fluoropolymer preferably contains ionic groups having a pKa of less than 10, more preferably less than 7. The ionic groups of the water-soluble fluoropolymer are preferably selected from the group consisting of sulfonate, carboxylate, phosphonate, and phosphate.

[0081] The terms "sulfonate, carboxylate, phosphonate, and phosphate" are intended to refer to the respective salts or the respective acids capable of forming salts. When salts are used, preferably the salts are alkali metal or ammonium salts. A preferred ionic group is a sulfonate group.

[0082] The water-soluble fluorine-containing polymer is preferably a polymer (I) containing polymerized units (I) based on a monomer (I) represented by general formula (I): General formula (I): CX １ X ３ =CX ２ R (-CZ １ Z ２ -A ０ ) ｍ (I) (wherein, X １ and X ３ are each independently F, Cl, H or CF ３ and X ２ is H, F, an alkyl group or a fluorine-containing alkyl group; A ０ is an anionic group; R is a linking group; Z １ and Z ２ are each independently H, F, an alkyl group or a fluorine-containing alkyl group; and m is an integer of 1 or more.

[0083] In the present disclosure, anionic groups include anionic groups such as sulfate groups, carboxylate groups, and acid groups such as —COOH, —COONH ４The anionic group includes a functional group that provides an anionic group such as an acid-base group, such as a sulfate group, a carboxylate group, a phosphate group, a phosphonate group, a sulfonate group, or a -C(CF ３ ) ２ OM (wherein M is —H, a metal atom, —NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group.

[0084] R is a linking group. In the present disclosure, a "linking group" is an (m+1)-valent linking group, and when m is 1, it is a divalent linking group. The linking group may be a single bond and preferably contains at least one carbon atom, and the number of carbon atoms may be 2 or more, 4 or more, 8 or more, 10 or more, or 20 or more. There is no upper limit, but it may be, for example, 100 or less, or 50 or less.

[0085] The linking group may be linear or branched, cyclic or acyclic in structure, saturated or unsaturated, substituted or unsubstituted, and may optionally contain one or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen, and may optionally contain one or more functional groups selected from the group consisting of ester, amide, sulfonamide, carbonyl, carbonate, urethane, urea, and carbamate. The linking group may not contain carbon atoms but may be a catenary heteroatom such as oxygen, sulfur, or nitrogen.

[0086] m is an integer of 1 or more, preferably 1 or 2, and more preferably 1. When m is an integer of 2 or more, Z １ , Z ２ and A ０ may be the same or different. Next, a preferred structure when m is 1 in general formula (I) will be described.

[0087] R is preferably a catenary heteroatom such as oxygen, sulfur, or nitrogen, or a divalent organic group.

[0088] When R is a divalent organic group, a hydrogen atom bonded to a carbon atom may be replaced with a halogen atom other than fluorine, such as chlorine, and may or may not contain a double bond. R may be either linear or branched, and may be cyclic or acyclic. R may also contain a functional group (e.g., ester, ether, ketone (keto group), amine, halide, etc.).

[0089] R may also be a non-fluorinated divalent organic group, or a partially fluorinated or perfluorinated divalent organic group.

[0090] R may be, for example, a hydrocarbon group in which no fluorine atoms are bonded to the carbon atoms, a hydrocarbon group in which some of the hydrogen atoms bonded to the carbon atoms are substituted with fluorine atoms, or a hydrocarbon group in which all of the hydrogen atoms bonded to the carbon atoms are substituted with fluorine atoms, and these may contain an oxygen atom, a double bond, or a functional group.

[0091] R is preferably a hydrocarbon group having 1 to 100 carbon atoms which may contain an ether bond or a keto group, and in the hydrocarbon group, some or all of the hydrogen atoms bonded to the carbon atoms may be substituted with fluorine.

[0092] R is preferably —(CH ２ ) ａ -, - (CF ２ ) ａ -, - (CF ２ ) ａ -O-, -O-(CF ２ ) ａ -, - (CF ２ ) ａ -O-(CF ２ ) ｂ -, -O(CF ２ ) ａ -O-(CF ２ ) ｂ -, - (CF ２ ) ａ -[O-(CF ２ ) ｂ ] ｃ -, -O(CF ２ ) ａ-[O-(CF ２ ) ｂ ] ｃ -、-[(CF ２ ) ａ -O] ｂ -[(CF ２ ) ｃ -O] ｄ -、-O[(CF ２ ) ａ -O] ｂ -、-O[(CF ２ ) ａ -O] ｂ -[(CF ２ ) ｃ -O] ｄ -、-O-[CF ２ CF(CF ３ )O] ａ -(CF ２ ) ｂ -、-O-(CF ２ ) ａ -O-[CF(CF ３ )CF ２ O] ｂ -O-、-O-[CF ２ CF(CF ３ )O] ａ -(CF ２ ) ｂ -O-、-O-[CF ２ CF(CF ３ )O] ａ -(CF ２ ) ｂ -O-[CF(CF ３ )CF ２ O] ｃ -O-、-[CF ２ CF(CF ３ )O] ａ -、-[CF(CF ３ )CF ２ O] ａ -、-(CF ２ ) ａ -O-[CF(CF ３ )CF ２ O] ａ -、-(CF ２ ) ａ -O-[CF(CF ３ )CF ２ O] ａ -(CF ２ )ｂ -, -[CF ２ CF (CF ３ )] ａ -CO-(CF ２ ) ｂ - and at least one selected from combinations thereof. In the formula, a, b, c, and d are independently at least 1. a, b, c, and d may independently be 2 or more, 3 or more, 4 or more, 10 or more, or 20 or more. The upper limit of a, b, c, and d is, for example, 100.

[0093] More preferably, R is —O—CF ２ -, -O-CF ２ CF ２ -, -O-CF ２ CF ２ —O—, —O—CF ２ CF ２ CF ２ -, -O-CF ２ CF ２ CF ２ —O—, —O—CF ２ CF (CF ３ ) -O-, -O-CF ２ CF ２ -O-CF(CF ３ )CF ２ —O—, —O—CF ２ CF (CF ３ )-O-CF ２ CF ２ —O— and —O—CF ２ CF (CF ３ )-O-CF ２ - At least one selected from the following.

[0094] R is a group represented by the general formula (r1): -CF ２ -O-(CX ６ ２ ) ｅ -{O-CF(CF ３ ) ｆ -(O) ｇ - (r1) (wherein, X ６ are each independently H, F or CF ３wherein e is an integer of 0 to 3, f is an integer of 0 to 3, and g is 0 or 1), and a divalent group represented by the general formula (r2): -CF ２ -O-(CX ７ ２ ) ｅ -(O) ｇ - (r2) (wherein, X ７ are each independently H, F or CF ３ wherein e is an integer of 0 to 3, and g is 0 or 1) is more preferred.

[0095] A specific example of a suitable R is —CF ２ —O—, —CF ２ -O-CF ２ -, -CF ２ -O-CH ２ -, -CF ２ -O-CH ２ CF ２ -, -O-CF ２ -, -O-CF ２ CF ２ -, -O-CF ２ CF ２ CF ２ -, -O-CF ２ CF ２ CF ２ CF ２ -, -O-CF ２ CF (CF ３ )-O-CF ２ -, -O-CF ２ CF (CF ３ )-O-CF ２ CF ２ -, -CF ２ -O-CF ２ CF ２ -, -CF ２ -O-CF ２ CH ２ -, -CF ２ -O-CF ２ CF ２ CH ２ -, -CF ２ -O-CF(CF ３ ) -, -CF ２ -O-CF(CF ３ )CF ２ -, -CF２ -O-CF(CF ３ )CF ２ —O—, —CF ２ -O-CF(CF ３ )CF ２ -O-CF ２ -, -CF ２ -O-CF(CF ３ ) CH ２ Among these, R is preferably a perfluoroalkylene group which may contain an oxygen atom, specifically, —CF ２ —O—, —CF ２ -O-CF ２ -, -O-CF ２ -, -O-CF ２ CF ２ -, -O-CF ２ CF (CF ３ )-O-CF ２ -, -O-CF ２ CF (CF ３ )-O-CF ２ CF ２ -, -CF ２ -O-CF ２ CF ２ -, -CF ２ -O-CF(CF ３ ) -, -CF ２ -O-CF(CF ３ )CF ２ - or -CF ２ -O-CF(CF ３ )CF ２ —O— is preferred.

[0096] -R-CZ of general formula (I) １ Z ２ - is a group represented by the general formula (s1): -CF ２ -O-(CX ６ ２ ) ｅ -{O-CF(CF ３ ) ｆ -(O) ｇ -CZ １ Z ２ - (s1) (wherein, X ６ are each independently H, F or CF ３wherein e is an integer of 0 to 3, f is an integer of 0 to 3, g is 0 or 1, and Z １ and Z ２ are each independently H, F, an alkyl group or a fluorine-containing alkyl group), and in formula (s1), Z １ and Z ２ is F or CF ３ is more preferred, one of which is F and the other is CF ３ It is more preferable that:

[0097] In addition, in the general formula (I), -R-CZ １ Z ２ - is a group represented by the general formula (s2): -CF ２ -O-(CX ７ ２ ) ｅ -(O) ｇ -CZ １ Z ２ - (s2) (wherein, X ７ are each independently H, F or CF ３ where e is an integer of 0 to 3, g is 0 or 1, and Z １ and Z ２ are each independently H, F, an alkyl group or a fluorine-containing alkyl group), and in formula (s2), Z １ and Z ２ is F or CF ３ is more preferred, one of which is F and the other is CF ３ It is more preferable that:

[0098] -R-CZ of general formula (I) １ Z ２ - is -CF ２ -O-CF ２ -, -O-CF ２ CF ２ -, -O-CF ２ CF ２ CF ２ -, -O-CF ２ CF ２ CF ２ CF ２ -, -O-CF ２ CF (CF ３ )-O-CF２ -、-O-CF ２ CF(CF ３ )-O-CF ２ CF ２ -、-O-CF ２ CF(CF ３ )-O-CF ２ CF ２ CF ２ -、-CF ２ -O-CF(CF ３ )-、-CF ２ -O-C(CF ３ ) ２ -、-CF ２ -O-CF ２ -CF ２ -、-CF ２ -O-CF ２ -CF(CF ３ )-、-CF ２ -O-CF ２ -C(CF ３ ) ２ -、-CF ２ -O-CF ２ CF ２ -CF ２ -、-CF ２ -O-CF ２ CF ２ -CF(CF ３ )-、-CF ２ -O-CF ２ CF ２ -C(CF ３ ) ２ -、-CF ２ -O-CF(CF ３ )-CF ２ -、-CF ２ -O-CF(CF ３ )-CF(CF ３ )-、-CF ２ -O-CF(CF ３ )-C(CF ３ ) ２ -、-CF ２ -O-CF(CF ３ )CF ２ -CF ２ -、-CF ２ -O-CF(CF ３ )CF ２ -CF(CF ３ )-、-CF２ -O-CF(CF ３ )CF ２ -C(CF ３ ) ２ -、-CF ２ -O-CF(CF ３ )CF ２ -O-CF ２ -、-CF ２ -O-CF(CF ３ )CF ２ -O-CF(CF ３ )-、or, -CF ２ -O-CF(CF ３ )CF ２ -O-C(CF ３ ) ２ - is preferred, -O-CF ２ CF ２ -、-O-CF ２ CF ２ CF ２ -、-O-CF ２ CF ２ CF ２ CF ２ -、-O-CF ２ CF(CF ３ )-O-CF ２ -、-O-CF ２ CF(CF ３ )-O-CF ２ CF ２ -、-CF ２ -O-CF(CF ３ )-、-CF ２ -O-CF ２ -CF(CF ３ )-、-CF ２ -O-CF ２ CF ２ -CF(CF ３ )-、-CF ２ -O-CF(CF ３ )-CF(CF ３ )-、-CF ２ -O-CF(CF ３ )CF ２ -CF(CF ３ )-、or, -CF ２ -O-CF(CF ３ )CF ２ -O-CF(CF ３)- is more preferred, and —O—CF ２ CF ２ -, -O-CF ２ CF (CF ３ )-O-CF ２ CF ２ - is more preferred.

[0099] It is also preferred that the polymer (I) is highly fluorinated. For example, the polymer (I) contains phosphate group moieties (e.g., CH ２ OP (O) (OM) ２ ) and sulfate group moieties (e.g., CH ２ OS (O) ２ anionic groups (A) such as ０ ), it is preferred that 80% or more, 90% or more, 95% or more, or 100% of the C—H bonds in polymer (I) are substituted with C—F bonds.

[0100] The monomer (I) and the polymer (I) contain an anionic group (A ０ ) except for the above, it is also preferable that the compound has a C—F bond and does not have a C—H bond. １ , X ２ , and X ３ is preferably F, and R is a perfluoroalkylene group having one or more carbon atoms, and the perfluoroalkylene group may be either linear or branched, may be cyclic or acyclic, and may contain at least one catenary heteroatom. The number of carbon atoms in the perfluoroalkylene group may be 2 to 20, or may be 4 to 18.

[0101] The monomer (I) and the polymer (I) may be partially fluorinated. That is, the monomer (I) and the polymer (I) may have an anionic group (A ０ ), it is also preferred that the alkyl group has at least one hydrogen atom bonded to a carbon atom and at least one fluorine atom bonded to a carbon atom.

[0102] Anionic group (A ０ ) is -SO ２ M, -SO ３ M, -OSO ３ M, -COOM, -SO２ NR'CH ２ COOM, -CH ２ OP (O) (OM) ２ , [-CH ２ O] ２ P(O)(OM), -CH ２ CH ２ OP (O) (OM) ２ , [-CH ２ CH ２ O] ２ P(O)(OM), -CH ２ CH ２ OSO ３ M, -P(O)(OM) ２ , -SO ２ NR'CH ２ CH ２ OP (O) (OM) ２ , [-SO ２ NR'CH ２ CH ２ O] ２ P(O)(OM), -CH ２ OSO ３ M, -SO ２ NR'CH ２ CH ２ OSO ３ M, or -C(CF ３ ) ２ Among them, -SO ３ M, -OSO ３ M, -COOM, -P(O)(OM) ２ or -C(CF ３ ) ２ -OM is preferred, -COOM and -SO ３ M, -OSO ３ M, -P(O)(OM) ２ or -C(CF ３ ) ２ OM is more preferred, and —SO ３ M, -COOM or -P(O)(OM) ２ is more preferred, and —SO ３ M or -COOM is particularly preferred.

[0103] M is H, a metal atom, or NR ７ ４, optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group.

[0104] The metal atom includes alkali metals (Group 1) and alkaline earth metals (Group 2), and is preferably Na, K or Li.

[0105] M is —H, a metal atom, or NR ７ ４ is preferred, and —H, an alkali metal (Group 1), an alkaline earth metal (Group 2), or NR ７ ４ is more preferred, and —H, —Na, —K, —Li or NH ４ is more preferred, and —H, —Na, —K or NH ４ is even more preferred, and —H, —Na or NH ４ is particularly preferred, and —H or —NH ４ is most preferred.

[0106] In the polymer (I), each polymer unit (I) may have a different anionic group or may have the same anionic group.

[0107] The monomer (I) is preferably a monomer represented by the general formula (Ia). The polymer (I) is preferably a polymer containing a polymerized unit (Ia) based on the monomer represented by the general formula (Ia). CF ２ ═CF—O—Rf ０ -A ０ (Ia) (wherein A ０ is an anionic group, and Rf ０ is a perfluorinated divalent linking group which may be linear or branched, cyclic or acyclic in structure, saturated or unsaturated, substituted or unsubstituted, and which optionally contains one or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen.

[0108] The monomer (I) is preferably a monomer represented by the general formula (Ib). The polymer (I) is preferably a polymer containing a polymerized unit (Ib) based on the monomer represented by the general formula (Ib). CH２ =CH-O-Rf ０ -A ０ (Ib) (wherein, A ０ is an anionic group, and Rf ０ is a perfluorinated divalent linking group as defined in formula Ia.

[0109] In general formula (I), A ０ is a sulfate group. ０ is, for example, -CH ２ OSO ３ M, -CH ２ CH ２ OSO ３ M or -SO ２ NR'CH ２ CH ２ OSO ３ M, where R' is H or an alkyl group having 1 to 4 carbon atoms, and M is the same as above.

[0110] A ０ is a sulfate group, examples of the monomer represented by general formula (I) include CF ２ =CF(OCF ２ CF ２ CH ２ OSO ３ M), CF ２ =CF(O(CF ２ ) ４ CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ CH ２ OSO ３ M), CH ２ =CH(O(CF ２ ) ４ CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF２ SO ２ N (CH ３ ) CH ２ CH ２ OSO ３ M), CH ２ =CH(OCF ２ CF ２ CH ２ OSO ３ M), CF ２ =CF(OCF ２ CF ２ CF ２ CF ２ SO ２ N (CH ３ ) CH ２ CH ２ OSO ３ M), CH ２ =CH(OCF ２ CF ２ CF ２ CH ２ OSO ３ In the above formula, M is the same as above.

[0111] In general formula (I), A ０ In one preferred embodiment, A is a sulfonate group. ０ For example, -SO ３ M, where M is the same as above.

[0112] A ０ is a sulfonate group, the monomer represented by general formula (I) is ２ =CF(OCF ２ CF ２ SO ３ M), CF ２ =CF(O(CF ２ ) ３ SO ３ M), CF ２ =CF(O(CF ２ ) ４ SO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) SO ３ M), CF ２ =CF(OCF ２ CF (CF ３) OCF ２ CF ２ SO ３ M), CH ２ =CH(OCF ２ CF ２ SO ３ M), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ CF ２ CF ２ SO ３ M), CH ２ =CH(O(CF ２ ) ４ SO ３ M), CH ２ =CH(O(CF ２ ) ３ SO ３ In the above formula, M is the same as above.

[0113] In general formula (I), A ０ In one preferred embodiment, A is a carboxylate group. ０ Examples of the ２ NR'CH ２ COOM, where R' is H or an alkyl group having 1 to 4 carbon atoms, and M is the same as above. ０ is a carboxylate group, the monomer represented by general formula (I) is ２ =CF(OCF ２ CF ２ COOM), C.F. ２ =CF(O(CF ２ ) ３ COOM), C.F. ２ =CF(O(CF ２ ) ４ COOM), C.F. ２ =CF(O(CF ２ ) ５ COOM), C.F. ２ =CF(OCF ２ CF (CF ３ ) COOM), CF ２ =CF(OCF ２ CF (CF ３ ) O(CF２ ) ｎ COOM) (n is greater than 1), CH ２ =CH(OCF ２ CF ２ COOM), CH ２ =CH(O(CF ２ )) ４ COOM), CH ２ =CH(O(CF ２ )) ３ COOM), CF ２ =CF(OCF ２ CF ２ SO ２ NR'CH ２ COOM), CF ２ =CF(O(CF ２ )) ４ SO ２ NR'CH ２ COOM), CF ２ =CF(OCF ２ CF(CF ３ )SO ２ NR'CH ２ COOM), CF ２ =CF(OCF ２ CF(CF ３ ))OCF ２ CF ２ SO ２ NR'CH ２ COOM), CH ２ =CH(OCF ２ CF ２ SO ２ NR'CH ２ COOM), CF ２ =CF(OCF ２ CF(CF ３ ))OCF ２ CF ２ CF ２ CF ２ SO ２ NR'CH ２ COOM), CH ２ =CH(O(CF ２ )) ４ SO ２ NR'CH ２ COOM), CH ２ =CH(O(CF ２ )) ３ SO ２NR'CH ２ In the above formula, R' is H or an alkyl group having 1 to 4 carbon atoms, and M is the same as above.

[0114] In general formula (I), A ０ In one preferred embodiment, A is a phosphate group. ０ Examples of the group include -CH ２ OP (O) (OM) ２ , [-CH ２ O] ２ P(O)(OM), -CH ２ CH ２ OP (O) (OM) ２ , [-CH ２ CH ２ O] ２ P(O)(OM), [-SO ２ NR'CH ２ CH ２ O] ２ P(O)(OM) or SO ２ NR'CH ２ CH ２ OP (O) (OM) ２ wherein R' is an alkyl group having 1 to 4 carbon atoms, and M is the same as above.

[0115] A ０ is a phosphate, the monomer represented by general formula (I) is CF ２ =CF(OCF ２ CF ２ CH ２ OP (O) (OM) ２ ), CF ２ =CF(O(CF ２ ) ４ CH ２ OP (O) (OM) ２ ), CF ２ =CF(OCF ２ CF (CF ３ ) CH ２ OP (O) (OM) ２ ), CF ２ =CF(OCF ２ CF (CF ３ ) OCF ２ CF ２ CH ２ OP (O) (OM)２ ), CF ２ =CF(OCF ２ CF ２ SO ２ N (CH ３ ) CH ２ CH ２ OP (O) (OM) ２ ), CF ２ =CF(OCF ２ CF ２ CF ２ CF ２ SO ２ N (CH ３ ) CH ２ CH ２ OP (O) (OM) ２ ), C.H. ２ =CH(OCF ２ CF ２ CH ２ OP (O) (OM) ２ ), C.H. ２ =CH(O(CF ２ ) ４ CH ２ OP (O) (OM) ２ ), C.H. ２ =CH(O(CF ２ ) ３ CH ２ OP (O) (OM) ２ In the above formula, M is the same as above.

[0116] In general formula (I), A ０ In one preferred embodiment, A is a phosphonate group. ０ is a phosphonate group, the monomer represented by general formula (I) is ２ =CF(OCF ２ CF ２ P(O)(OM) ２ ), CF ２ =CF(O(CF ２ ) ４ P(O)(OM) ２ ), CF ２ =CF(OCF ２ CF (CF ３ ) P (O) (OM) ２ ), CF ２ =CF(OCF ２ CF (CF３ ) OCF ２ CF ２ P(O)(OM) ２ ), C.H. ２ =CH(OCF ２ CF ２ P(O)(OM) ２ ), C.H. ２ =CH(O(CF ２ ) ４ P(O)(OM) ２ ), C.H. ２ =CH(O(CF ２ ) ３ P(O)(OM) ２ ) wherein M is the same as above.

[0117] The monomer (I) is preferably a monomer (1) represented by the general formula (1). The polymer (I) is preferably a polymer (1) containing a polymer unit (1) based on the monomer represented by the general formula (1). CX ２ =CY(-CZ ２ -O-Rf-A) (1) (In the formula, X is the same or different and represents -H or F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Z is the same or different and represents -H, -F, an alkyl group or a fluoroalkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. A is -COOM, -SO ３ M, -OSO ３ M or -C(CF ３ ) ２ OM (M is -H, metal atom, -NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group.) However, at least one of X, Y, and Z contains a fluorine atom.)

[0118] The polymer (1) may be a homopolymer of the monomer (1) represented by the general formula (1), or may be a copolymer with other monomers.

[0119] The fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond is an alkylene group that does not contain a structure in which an oxygen atom is at the terminal and that contains an ether bond between carbon atoms.

[0120] In general formula (1), X is —H or F. Both Xs may be —F, or at least one X may be —H. For example, one X may be —F and the other may be —H, or both Xs may be —H.

[0121] In general formula (1), Y is -H, -F, an alkyl group or a fluorine-containing alkyl group. The alkyl group is an alkyl group that does not contain a fluorine atom, and may have one or more carbon atoms. The alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and may have one or more carbon atoms. The fluorine-containing alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The Y may be -H, -F or CF ３ is preferred, and —F is more preferred.

[0122] In general formula (1), Z's may be the same or different and are -H, -F, an alkyl group, or a fluoroalkyl group. The alkyl group is an alkyl group that does not contain a fluorine atom, and may have one or more carbon atoms. The alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and may have one or more carbon atoms. The fluorine-containing alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The Z's may be -H, -F, or CF ３ is preferred, and —F is more preferred.

[0123] In general formula (1), at least one of X, Y, and Z contains a fluorine atom. For example, X may be —H, and Y and Z may be —F.

[0124] In the general formula (1), Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond.

[0125] The number of carbon atoms in the fluorine-containing alkylene group is preferably 2 or more. The number of carbon atoms in the fluorine-containing alkylene group is preferably 30 or less, more preferably 20 or less, even more preferably 10 or less, particularly preferably 6 or less, and most preferably 3 or less. The fluorine-containing alkylene group includes, for example, —CF ２ -, -CH ２ CF ２ -, -CF ２ CF ２ -, -CF ２ CH ２ -, -CF ２ CF ２ CF ２ -, -CF ２ CF ２ CH ２ -, -CF(CF ３ ) -, -CF(CF ３ )CF ２ -, -CF(CF ３ ) CH ２ The fluorine-containing alkylene group is preferably a perfluoroalkylene group.

[0126] The number of carbon atoms of the fluorine-containing alkylene group having an ether bond is preferably 3 or more. The number of carbon atoms of the fluorine-containing alkylene group having an ether bond is preferably 60 or less, more preferably 30 or less, even more preferably 12 or less, particularly preferably 9 or less, and most preferably 6 or less. The fluorine-containing alkylene group having an ether bond is, for example, a group represented by the general formula: (In the formula, Z １ is F or CF ３ ;Z ２ and Z ３ are H or F; Z ４ is H, F or CF ３ p1+q1+r1 is an integer of 1 to 10; s1 is 0 or 1; and t1 is an integer of 0 to 5).

[0127] Specific examples of the fluorine-containing alkylene group having an ether bond include —CF ２ CF (CF ３ ) OCF ２ -, -CF(CF ３ )CF ２ -O-CF(CF ３ )-,-(CF(CF ３ )CF ２ -O) ｎ -CF (CF ３ )-(wherein n is an integer from 1 to 10), -CF(CF ３ )CF ２ -O-CF(CF ３ ) CH ２ -, -(CF(CF ３ )CF ２ -O) ｎ -CF (CF ３ ) CH ２ - (wherein n is an integer of 1 to 10), -CH ２ CF ２ CF ２ O-CH ２ CF ２ CH ２ -, -CF ２ CF ２ CF ２ O-CF ２ -, -CF ２ CF ２ CF ２ O-CF ２ CF ２ -, -CF ２ CF ２ CF ２ O-CF ２ CF ２ CF ２ -, -CF ２ CF ２ CF ２ O-CF ２ CF ２ CH ２ -, -CF ２ CF ２ O-CF ２ -, -CF ２ CF ２ O-CF ２ CH ２The fluorine-containing alkylene group having an ether bond is preferably a perfluoroalkylene group.

[0128] In the general formula (1), A is -COOM, -SO ３ M, -OSO ３ M or -C(CF ３ ) ２ OM (M is H, metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group).

[0129] R ７ As the group, H or C １－１０ is preferably an organic group of the formula １－４ More preferred are organic groups of the formula: １－４ More preferred are alkyl groups of the formula:

[0130] The metal atom includes alkali metals (Group 1) and alkaline earth metals (Group 2), and is preferably Na, K or Li.

[0131] M is H, a metal atom, or NR ７ ４ is preferred, and H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or NR ７ ４ is more preferred, and H, Na, K, Li or NH ４ is more preferred, and H, Na, K or NH ４ is even more preferred, H, Na or NH ４ is particularly preferred, and H or NH ４ is most preferred.

[0132] A is -COOM or -SO ３ M is preferred.

[0133] Examples of the monomer represented by the general formula (1) include a monomer represented by the general formula (1a): CX ２ =CFCF ２ -O-(CF(CF ３ )CF ２ O)ｎ５ -CF (CF ３ )-A (1a) (wherein each X is the same and represents F or H, n5 represents 0 or an integer of 1 to 10, and A is as defined above).

[0134] In general formula (1a), n5 is preferably 0 or an integer of 1 to 5, more preferably 0, 1 or 2, and even more preferably 0 or 1, in that particles having a small primary particle size can be obtained.

[0135] The polymer (1) may be a homopolymer of the monomer represented by the general formula (1a) or a copolymer with other monomers.

[0136] The monomer (1) is preferably a monomer represented by the general formula (1A). The polymerized unit (1) is preferably a polymerized unit (1A) based on a monomer represented by the general formula (1A). CH ２ =CF(-CF ２ —O—Rf-A) (1A) (wherein Rf and A are the same as defined above.)

[0137] The polymer (1) may be a homopolymer of the monomer represented by the general formula (1A) or a copolymer with other monomers.

[0138] Specific examples of the monomer represented by formula (1A) include the monomer represented by the general formula:

[0139]

[0140] (In the formula, Z １ is F or CF ３ ;Z ２ and Z ３ are H or F; Z ４ is H, F or CF ３ p1+q1+r1 is an integer of 0 to 10; s1 is 0 or 1; t1 is an integer of 0 to 5, provided that Z ３ and Z ４ are both H, then p1+q1+r1+s1 is not 0; A is the same as defined above). More specifically,

[0141]

[0142] Among them,

[0143]

[0144] It is preferable that:

[0145] In the monomer represented by the general formula (1A), A in the formula (1A) is preferably -COOM, and particularly preferably CH ２ =CFCF ２ OCF (CF ３ ) COOM, and CH ２ =CFCF ２ OCF (CF ３ )CF ２ OCF (CF ３ )COOM (wherein M is as defined above), and CH ２ =CFCF ２ OCF (CF ３ ) COOM is more preferred.

[0146] Further, examples of the monomer represented by general formula (1) include a monomer represented by the following formula: CF ２ =CFCF ２ -O-Rf-A (wherein Rf and A are the same as above)

[0147] More specifically, etc.

[0148] The monomer (I) is preferably a monomer (2) represented by the general formula (2). The polymer (I) is preferably a polymer (2) containing a polymer unit (2) based on the monomer represented by the general formula (2). CX ２ =CY(-O-Rf-A) (2) (In the formula, X's may be the same or different and each represent -H or F; Y represents -H, -F, an alkyl group or a fluorine-containing alkyl group; Rf represents a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and having an ether bond or a keto group; and A is the same as defined above.)

[0149] The polymer (2) may be a homopolymer of the monomer represented by the general formula (2) or a copolymer with other monomers.

[0150] In general formula (2), X is —H or F. Both Xs may be —F, or at least one X may be —H. For example, one X may be —F and the other may be —H, or both Xs may be —H.

[0151] In general formula (2), Y is -H, -F, an alkyl group, or a fluorine-containing alkyl group. The alkyl group is an alkyl group that does not contain a fluorine atom, and may have one or more carbon atoms. The alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. The fluorine-containing alkyl group is an alkyl group that contains at least one fluorine atom, and may have one or more carbon atoms. The fluorine-containing alkyl group preferably has six or fewer carbon atoms, more preferably four or fewer carbon atoms, and even more preferably three or fewer carbon atoms. Y is -H, -F, or -CF ３ is preferred, and —F is more preferred.

[0152] In general formula (2), it is preferable that at least one of X and Y contains a fluorine atom. For example, X may be —H, and Y and Z may be —F.

[0153] In general formula (2), Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms, a fluorine-containing alkylene group having an ether bond having 2 to 100 carbon atoms, or a fluorine-containing alkylene group having a keto group having 2 to 100 carbon atoms. The fluorine-containing alkylene group having an ether bond having 2 to 100 carbon atoms is an alkylene group that does not contain a structure in which an oxygen atom is at the terminal and that contains an ether bond between carbon atoms.

[0154] The carbon number of the fluorine-containing alkylene group of Rf is preferably 2 or more, and more preferably 30 or less, more preferably 20 or less, even more preferably 10 or less, and particularly preferably 5 or less. Examples of the fluorine-containing alkylene group include -CF ２ -, -CH ２ CF ２ -, -CF ２ CF ２ -, -CF ２CH ２ -, -CF ２ CF ２ CH ２ -, -CF(CF ３ ) -, -CF(CF ３ )CF ２ -, -CF(CF ３ ) CH ２ -, -CF ２ CF ２ CF ２ -, CF ２ CF ２ CF ２ CF ２ The fluorine-containing alkylene group is preferably a perfluoroalkylene group, and more preferably an unbranched linear perfluoroalkylene group.

[0155] The number of carbon atoms in the fluorine-containing alkylene group having an ether bond is preferably 3 or more. The number of carbon atoms in the fluorine-containing alkylene group having an ether bond is preferably 60 or less, more preferably 30 or less, even more preferably 12 or less, and particularly preferably 5 or less. The fluorine-containing alkylene group having an ether bond is, for example, a group represented by the general formula: (In the formula, Z １ is F or CF ３ ;Z ２ and Z ３ are H or F; Z ４ is H, F or CF ３ p1+q1+r1 is an integer of 1 to 10; s1 is 0 or 1; and t1 is an integer of 0 to 5).

[0156] Specific examples of the fluorine-containing alkylene group having an ether bond include —CF ２ CF (CF ３ ) OCF ２ -, -CF ２ CF (CF ３ ) OCF ２ CF ２ -, -CF ２ CF (CF ３ ) OCF ２ CF ２ CF ２ -, -CF(CF ３ )CF２ -O-CF(CF ３ )-,-(CF(CF ３ )CF ２ -O) ｎ -CF (CF ３ )-(wherein n is an integer from 1 to 10), -CF(CF ３ )CF ２ -O-CF(CF ３ ) CH ２ -, -(CF(CF ３ )CF ２ -O) ｎ -CF (CF ３ ) CH ２ - (wherein n is an integer of 1 to 10), -CH ２ CF ２ CF ２ O-CH ２ CF ２ CH ２ -, -CF ２ CF ２ CF ２ O-CF ２ -, -CF ２ CF ２ CF ２ O-CF ２ CF ２ -, -CF ２ CF ２ CF ２ O-CF ２ CF ２ CF ２ -, -CF ２ CF ２ CF ２ O-CF ２ CF ２ CH ２ -, -CF ２ CF ２ O-CF ２ -, -CF ２ CF ２ O-CF ２ CH ２ The fluorine-containing alkylene group having an ether bond is preferably a perfluoroalkylene group.

[0157] The number of carbon atoms in the fluorine-containing alkylene group having a keto group is preferably 3 or more. The number of carbon atoms in the fluorine-containing alkylene group having a keto group is preferably 60 or less, more preferably 30 or less, even more preferably 12 or less, and particularly preferably 5 or less.

[0158] Specific examples of the fluorine-containing alkylene group having a keto group include: ２ CF (CF ３ )CO-CF ２ -, -CF ２ CF (CF ３ )CO-CF ２ CF ２ -, -CF ２ CF (CF ３ )CO-CF ２ CF ２ CF ２ -, -CF ２ CF (CF ３ )CO-CF ２ CF ２ CF ２ CF ２ The fluorine-containing alkylene group having a keto group is preferably a perfluoroalkylene group.

[0159] Water may be added to the keto group in the fluorine-containing alkylene group. Therefore, the monomer (2) may be a hydrate. Examples of the fluorine-containing alkylene group in which water is added to the keto group include —CF ２ CF (CF ３ )C(OH) ２ -CF ２ -, -CF ２ CF (CF ３ )C(OH) ２ -CF ２ CF ２ -, -CF ２ CF (CF ３ )C(OH) ２ -CF ２ CF ２ CF ２ -, -CF ２ CF (CF ３ )C(OH) ２ -CF ２ CF ２ CF ２ CF ２--etc.

[0160] The monomer represented by general formula (2) is preferably at least one selected from the group consisting of monomers represented by general formulas (2a), (2b), (2c), (2d), (2e), (2f) and (2g). ２ =CF-O-(CF ２ ) ｎ１ -A (2a) (wherein n1 represents an integer of 1 to 10, and A is the same as defined above) CF ２ =CF-O-(CF ２ C (CF ３ ) F) ｎ２ -A (2b) (wherein n2 represents an integer of 1 to 5, and A is as defined above) CF ２ =CF-O-(CFX １ ) ｎ３ -A (2c) (wherein, X １ is F or CF ３ wherein n3 represents an integer of 1 to 10, and A is as defined above. ２ =CF-O-(CF ２ CFX １ O) ｎ４ -(CF ２ ) ｎ６ -A (2d) (wherein n4 represents an integer of 1 to 10, n6 represents an integer of 1 to 3, and A and X １ is the same as the definition above.) CF ２ =CF-O-(CF ２ CF ２ CFX １ O) ｎ５ -CF ２ CF ２ CF ２ -A (2e) (wherein n5 represents an integer of 0 to 10, and A and X １ is the same as the definition above.) CF ２ =CF-O-(CF ２ ) ｎ７ -O-(CF ２ ) ｎ８ -A (2f) (wherein n7 represents an integer of 1 to 10, n8 represents an integer of 1 to 3, and A is as defined above.) CF ２=CF[OCF ２ CF (CF ３ )] ｎ９ O (CF ２ ) ｎ１０ O[CF(CF ３ )CF ２ O] ｎ１１ CF (CF ３ )-A (2g) (wherein n9 represents an integer of 0 to 5, n10 represents an integer of 1 to 8, and n11 represents an integer of 0 to 5. A is as defined above.)

[0161] In the general formula (2a), n1 is preferably an integer of 5 or less, and more preferably an integer of 2 or less.

[0162] Examples of the monomer represented by general formula (2a) include CF ２ =CF-O-CF ２ COOM, C.F. ２ =CF(OCF ２ CF ２ COOM), C.F. ２ =CF(O(CF ２ ) ３ COOM), C.F. ２ =CF(OCF ２ CF ２ SO ３ M), CF ２ = CFOCF ２ SO ３ M., C.F. ２ = CFOCF ２ CF ２ CF ２ SO ３ M (wherein M is as defined above).

[0163] In general formula (2b), n2 is preferably an integer of 3 or less, from the viewpoint of the dispersion stability of the resulting composition.

[0164] In the general formula (2c), n3 is preferably an integer of 5 or less from the viewpoint of water solubility, A is preferably -COOM, and M is preferably H, Na, or NH ４ It is preferable that:

[0165] In general formula (2d), X １In terms of dispersion stability of the composition, -CF ３ n4 is preferably an integer of 5 or less in terms of water solubility, A is preferably -COOM, and M is H, Na, or NH ４ It is preferable that:

[0166] Examples of the monomer represented by general formula (2d) include CF ２ = CFOCF ２ CF (CF ３ ) OCF ２ CF ２ COOM, C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ COOM, C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ CF ２ CF ２ COOM, C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ SO ３ M., C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ CF ２ SO ３ M., C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ CF ２ CF ２ SO ３ M (wherein M is H, NH ４ or an alkali metal.

[0167] In the general formula (2e), n5 is preferably an integer of 5 or less from the viewpoint of water solubility, A is preferably -COOM, and M is preferably H or NH ４ It is preferable that:

[0168] Examples of the monomer represented by general formula (2e) include CF ２ = CFOCF ２ CF２ CF ２ COOM (wherein M is H, Na, NH ４ or an alkali metal.

[0169] In the general formula (2f), n7 is preferably an integer of 5 or less in terms of water solubility, and A is -COOM or -SO ３ M is preferred, and -COOM is more preferred. M is H, Na, K or NH ４ It is preferable that:

[0170] Examples of the monomer represented by general formula (2f) include CF ２ =CF-O-(CF ２ ) ３ -O-CF ２ -COOM (wherein M is H, NH ４ or an alkali metal.

[0171] In the general formula (2g), n9 is preferably an integer of 3 or less in terms of water solubility, n10 is preferably an integer of 3 or less, n11 is preferably an integer of 3 or less, and A is -COOM or -SO ３ M is preferred, and -COOM is more preferred. M is H, Na, K or NH ４ It is preferable that:

[0172] Examples of the monomer represented by general formula (2g) include CF ２ = CFO (CF ２ ) ２ OCF (CF ３ ) COOM, C.F. ２ = CFOCF ２ CF ２ OCF (CF ３ )CF ２ OCF (CF ３ ) COOM, C.F. ２ = CFOCF ２ CF (CF ３ ) OCF ２ CF ２ OCF (CF ３ ) COOM, C.F. ２ =CF[OCF ２ CF (CF３ )] ２ O (CF ２ ) ２ O[CF(CF ３ )CF ２ O]CF(CF ３ ) COOM, C.F. ２ =CF[OCF ２ CF (CF ３ )] ３ O (CF ２ ) ２ O[CF(CF ３ )CF ２ O] ３ CF (CF ３ ) COOM (wherein M is H, NH ４ or an alkali metal.

[0173] The monomer (I) is preferably a monomer (3) represented by the general formula (3). The polymer (I) is preferably a polymer (3) containing a polymer unit (3) based on the monomer represented by the general formula (3). CX ２ =CY(-Rf-A) (3) (In the formula, X is the same or different and represents -H or F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond; and A is the same as defined above.)

[0174] The polymer (3) may be a homopolymer of the monomer represented by the general formula (3) or a copolymer with other monomers.

[0175] The fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond is an alkylene group that does not contain a structure in which an oxygen atom is at the terminal and that contains an ether bond between carbon atoms.

[0176] In general formula (3), Rf is preferably a fluorine-containing alkylene group having 1 to 40 carbon atoms. In general formula (3), at least one of X and Y preferably contains a fluorine atom.

[0177] The monomer represented by the general formula (3) is represented by the general formula (3a): CF ２ =CF-(CF２ ) ｎ１ -A (3a) (wherein n1 represents an integer of 1 to 10, and A is as defined above), and a monomer represented by the general formula (3b): CF ２ =CF-(CF ２ C (CF ３ ) F) ｎ２ -A (3b) (wherein n2 represents an integer of 1 to 5, and A is as defined above) is preferred.

[0178] In the general formula (3a) and the general formula (3b), A is —SO ３ M or COOM is preferred, where M is H, a metal atom, NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium. ７ represents H or an organic group.

[0179] In the general formula (3a), n1 is preferably an integer of 5 or less, more preferably an integer of 2 or less. A is preferably -COOM, and M is preferably H or NH. ４ It is preferable that:

[0180] Examples of the monomer represented by general formula (3a) include CF ２ =CFCF ２ COOM (wherein M is as defined above).

[0181] In the general formula (3b), n2 is preferably an integer of 3 or less from the viewpoint of dispersion stability of the resulting composition, A is preferably -COOM, and M is preferably H or NH ４ It is preferable that:

[0182] Next, a preferred structure when m in general formula (I) is an integer of 2 or more will be described.

[0183] It is also preferred that the monomer (I) is at least one selected from the group consisting of monomers represented by general formula (4a) and general formula (4b). It is also preferred that the polymer (I) is a polymer (4) containing polymerization units (4) based on at least one monomer selected from the group consisting of monomers represented by general formula (4a) and general formula (4b). CF ２ =CF-CF ２ -O-Q Ｆ１ -CF(-Q Ｆ２ -CZ １ Z ２ -A) ２ (4a) (wherein, Z １ , Z ２ and A is the same as defined above, Q Ｆ１ and Q Ｆ２ are the same or different and are a single bond, a fluorine-containing alkylene group which may contain an ether bond between carbon atoms, or a fluorine-containing oxyalkylene group which may contain an ether bond between carbon atoms. ２ =CF-O-Q Ｆ１ -CF(-Q Ｆ２ -CZ １ Z ２ -A) ２ (4b) (wherein, Z １ , Z ２ , A, Q Ｆ１ and Q Ｆ２ is the same as above)

[0184] The monomers represented by general formula (4a) and general formula (4b) include: etc.

[0185] The monomer (I) is preferably at least one selected from the group consisting of the monomer (1), the monomer (2), and the monomer (3), more preferably the monomer (1) or the monomer (2), and even more preferably the monomer (2). The polymer (I) is preferably at least one selected from the group consisting of the polymer (1), the polymer (2), and the polymer (3), more preferably the polymer (1) or the polymer (2), and even more preferably the polymer (2).

[0186] The polymer (I) may be a homopolymer consisting of only the polymerized unit (I), or may be a copolymer containing the polymerized unit (I) and a polymerized unit based on another monomer copolymerizable with the monomer represented by the general formula (I). From the viewpoint of solubility in an aqueous medium, a homopolymer consisting of only the polymerized unit (I) is preferred. The polymerized units (I) may be the same or different in each occurrence, and the polymer (I) may contain polymerized units (I) based on two or more different monomers represented by the general formula (I).

[0187] The other monomers include those represented by the general formula CFR=CR ２ (wherein R is independently H, F or a perfluoroalkyl group having 1 to 4 carbon atoms) is preferred. As the other monomer, a fluorine-containing ethylenic monomer having 2 or 3 carbon atoms is preferred. As the other monomer, for example, CF ２ =CF ２ , C.F. ２ = CFCl, CH ２ =CF ２ , CFH=CH ２ , CFH=CF ２ , C.F. ２ =CFCF ３ , C.H. ２ =CFCF ３ , C.H. ２ = CHCF ３ , CHF=CHCF ３ (E form), CHF=CHCF ３ (Z-isomer), etc.

[0188] Among these, tetrafluoroethylene (CF ２ =CF ２ ), chlorotrifluoroethylene (CF ２ =CFCl) and vinylidene fluoride (CH ２ =CF ２), and more preferably at least one selected from the group consisting of tetrafluoroethylene and vinylidene fluoride. Therefore, the polymerized units based on the other monomer are preferably polymerized units based on tetrafluoroethylene. The polymerized units based on the other monomer may be the same or different in each occurrence, and polymer (I) may contain polymerized units based on two or more different other monomers.

[0189] The other monomers also include those represented by the general formula (n1-2):

[0190]

[0191] (In the formula, X １ , X ２ are the same or different and are H or F; X ３ are H, F, Cl, CH ３ or CF ３ ;X ４ , X ５ are the same or different and are H or F; a and c are the same or different and are 0 or 1. ３ is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having 2 to 100 carbon atoms and having an ether bond).

[0192] Specifically, CH ２ =CFCF ２ -O-Rf ３ , C.F. ２ ═CF—O—Rf ３ , C.F. ２ =CFCF ２ -O-Rf ３ , C.F. ２ =CF-Rf ３ , C.H. ２ =CH-Rf ３ , C.H. ２ =CH-O-Rf ３ (wherein, Rf ３ is the same as the above formula (n1-2).

[0193] Examples of the other monomer include a monomer of the formula (n2-1):

[0194]

[0195] (In the formula, X ９ is H, F or CH ３ ; Rf ４ is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having 2 to 100 carbon atoms and having an ether bond). ４ The base is

[0196]

[0197] (wherein d3 is an integer of 1 to 4; e3 is an integer of 1 to 10).

[0198] Examples of the other monomer include a monomer represented by formula (n2-2): CH ２ =CHO-Rf ５ (n2-2) (wherein, Rf ５ is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having 2 to 100 carbon atoms and having an ether bond), and

[0199] Specific examples of the monomer of general formula (n2-2) include:

[0200]

[0201] (wherein e6 is an integer of 1 to 10) are preferred.

[0202] More specifically,

[0203]

[0204] Examples include:

[0205] Others include those represented by the general formula (n2-3): CH ２ =CHCH ２ O-Rf ６ (n2-3) (wherein, Rf ６ is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having 2 to 100 carbon atoms and an ether bond), a fluorine-containing allyl ether represented by the general formula (n2-4): CH ２ =CH-Rf ７ (n2-4) (wherein, Rf ７is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having 2 to 100 carbon atoms and having an ether bond), and the like.

[0206] Specific examples of the monomers represented by general formulas (n2-3) and (n2-4) include:

[0207]

[0208] Examples of such monomers include:

[0209] The polymer (I) usually has a terminal group. The terminal group is a terminal group generated during polymerization, and typical terminal groups are independently selected from hydrogen, iodine, bromine, linear or branched alkyl groups, and linear or branched fluoroalkyl groups, and may optionally contain at least one catenary heteroatom. The alkyl group or fluoroalkyl group preferably has 1 to 20 carbon atoms. These terminal groups are generally generated from the initiator or chain transfer agent used in forming the polymer (I) or during the chain transfer reaction.

[0210] In the polymer (I), the content of the polymerized units (I) relative to the total polymerized units is, in order of preference, 1.0 mol% or more, 3.0 mol% or more, 5.0 mol% or more, 10 mol% or more, 20 mol% or more, 30 mol% or more, 40 mol% or more, 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, and 90 mol% or more. The content of the polymerized units (I) is particularly preferably substantially 100 mol%, and the polymer (I) is most preferably composed only of the polymerized units (I).

[0211] In the polymer (I), the content of polymerization units based on other monomers copolymerizable with the monomer represented by general formula (I) is, in order of preference, 99.0 mol% or less, 97.0 mol% or less, 95.0 mol% or less, 90 mol% or less, 80 mol% or less, 70 mol% or less, 60 mol% or less, 50 mol% or less, 40 mol% or less, 30 mol% or less, 20 mol% or less, and 10 mol% or less, based on all polymerization units. It is particularly preferable that the content of polymerization units based on other monomers copolymerizable with the monomer represented by general formula (I) is substantially 0 mol%, and it is most preferable that the polymer (I) does not contain polymerization units based on other monomers.

[0212] In polymer (1), polymer (2), or polymer (3), the content of polymerized units (1), polymerized units (2), or polymerized units (3) relative to the total polymerized units is, in order of preference, 1.0 mol% or more, 3.0 mol% or more, 5.0 mol% or more, 10 mol% or more, 20 mol% or more, 30 mol% or more, 40 mol% or more, 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, or 90 mol% or more. The content of polymerized units (1), polymerized units (2), or polymerized units (3) is particularly preferably substantially 100 mol%, and polymer (1), polymer (2), or polymer (3) is most preferably composed solely of polymerized units (2) or polymerized units (3).

[0213] In polymer (1), polymer (2), or polymer (3), the content of polymerized units based on other monomers copolymerizable with polymerized units (1), polymerized units (2), or polymerized units (3) is, in order of preference, 99.0 mol% or less, 97.0 mol% or less, 95.0 mol% or less, 90 mol% or less, 80 mol% or less, 70 mol% or less, 60 mol% or less, 50 mol% or less, 40 mol% or less, 30 mol% or less, 20 mol% or less, and 10 mol% or less, based on the total polymerized units. It is particularly preferred that the content of polymerized units based on other monomers copolymerizable with polymerized units (1), polymerized units (2), or polymerized units (3) is substantially 0 mol%, and it is most preferred that polymer (1), polymer (2), or polymer (3) does not contain polymerized units based on other monomers.

[0214] The number average molecular weight of the polymer (I) is preferably 0.1 × 10 because this allows the polymer (I) to be recovered at a higher recovery rate. ４ Super, 0.2×10 ４ Above, 0.3 x 10 ４ That's it, 0.4 x 10 ４ That's it, 0.5 x 10 ４ That's it, 1.0 x 10 ４ That's it, 3.0 x 10 ４ or more, or 3.1 x 10 ４ The number average molecular weight of the polymer (I) is preferably 75.0×10 or more. ４ Below, 50.0 x 10 ４ Below, 40.0 x 10 ４ Below, 30.0 x 10 ４ or less, or 20.0 x 10 ４ It is preferable that:

[0215] The weight average molecular weight of the polymer (I) is 0.2 × 10 ４ That's it, 0.4 x 10 ４ That's it, 0.6 x 10 ４ That's it, 0.8 x 10 ４ That's it, 1.0 x 10 ４ That's it, 2.0 x 10 ４ That's it, 5.0 x 10 ４ That's it, 10.0 x 10 ４ That's it, 15.0 x 10 ４ That's it, 20.0 x 10 ４ or more, or 25.0 x 10 ４ The weight average molecular weight of the polymer (I) is preferably 150.0×10 or more. ４ Below, 100.0 x 10 ４ Below, 60.0 x 10 ４ Below, 50.0 x 10 ４ or less, or 40.0 x 10 ４ It is preferable that:

[0216] The number average molecular weight and weight average molecular weight of polymer (I) are values ​​calculated by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard. When measurement by GPC is not possible, the number average molecular weight of polymer (I) can be determined from the correlation between the number average molecular weight calculated from the number of terminal groups obtained by NMR, FT-IR, or the like, and the melt flow rate. The melt flow rate can be measured in accordance with JIS K 7210.

[0217] The number average molecular weight of polymer (1), polymer (2), or polymer (3) is preferably 0.1 × 10 because polymer (1), polymer (2), or polymer (3) can be recovered at a higher recovery rate. ４ Super, 0.2×10 ４ Above, 0.3 x 10 ４ That's it, 0.4 x 10 ４ That's it, 0.5 x 10 ４ That's it, 1.0 x 10 ４ That's it, 3.0 x 10 ４ or more, or 3.1 x 10 ４ The number average molecular weight of the polymer (1), polymer (2) or polymer (3) is preferably 75.0×10 or more. ４ Below, 50.0 x 10 ４ Below, 40.0 x 10 ４ Below, 30.0 x 10 ４ or less, or 20.0 x 10 ４ It is preferable that:

[0218] The weight average molecular weight of polymer (1), polymer (2), or polymer (3) is 0.2 × 10 ４ That's it, 0.4 x 10 ４ That's it, 0.6 x 10 ４ That's it, 0.8 x 10 ４ That's it, 1.0 x 10 ４ That's it, 2.0 x 10 ４ That's it, 5.0 x 10 ４ That's it, 10.0 x 10 ４ That's it, 15.0 x 10 ４ That's it, 20.0 x 10 ４ or more, or 25.0 x 10 ４The weight average molecular weight of the polymer (1), the polymer (2), or the polymer (3) is preferably 150.0×10 or more. ４ Below, 100.0 x 10 ４ Below, 60.0 x 10 ４ Below, 50.0 x 10 ４ or less, or 40.0 x 10 ４ It is preferable that:

[0219] The number average molecular weight and weight average molecular weight of polymer (1), polymer (2), or polymer (3) are values ​​calculated by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard. When measurement by GPC is not possible, the number average molecular weight of polymer (1), polymer (2), or polymer (3) can be determined from the correlation between the number average molecular weight calculated from the number of terminal groups obtained by NMR, FT-IR, or the like, and the melt flow rate. The melt flow rate can be measured in accordance with JIS K 7210.

[0220] The polymer (I) preferably has an ion exchange ratio (IXR) of 53 or less. The IXR is defined as the number of carbon atoms in the polymer backbone relative to the ionic group. ２ F) is not considered an ionizable group for purposes of determining IXR.

[0221] The IXR of the polymer (I) is preferably 0.5 or more, 1 or more, 3 or more, 4 or more, 5 or more, or 8 or more. The IXR of the polymer (I) is preferably 43 or less, 33 or less, or 23 or less.

[0222] The ion exchange capacity of the polymer (I) is preferably 0.80 meq / g or more, 1.50 meq / g or more, 1.75 meq / g or more, 2.00 meq / g or more, 2.20 meq / g or more, more than 2.20 meq / g, 2.50 meq / g or more, 2.60 meq / g or more, 3.00 meq / g or more, or 3.50 meq / g or more. The ion exchange capacity is the content of ionic groups (anionic groups) in the polymer (I) and is calculated from the composition of the polymer (I).

[0223] In polymer (I), the ionic (anionic) groups are typically distributed along the polymer backbone. The polymer (I) comprises a polymer backbone with recurring side chains attached to the backbone, which preferably carry ionic groups.

[0224] Preferably, polymer (I) comprises ionizable groups having a pKa of less than 10, more preferably less than 7. The ionizable groups of polymer (I) are preferably selected from the group consisting of sulfonate, carboxylate, phosphonate, and phosphate.

[0225] The terms "sulfonate, carboxylate, phosphonate, and phosphate" are intended to refer to the respective salts or the respective acids capable of forming salts. When salts are used, preferably the salts are alkali metal or ammonium salts. A preferred ionic group is a sulfonate group.

[0226] In addition, the water-soluble fluorine-containing polymer may be a polymer represented by the general formula: T Ｘ -O-[R ｆ １ -O] ｎ１ [R ｆ ２ -O] ｎ２ -T Ｘ’ (In the formula, T ｘ and T Ｘ’ are each independently at least one selected from the group consisting of (hydro)(fluoro)carbon groups having 1 to 24 carbon atoms and having one or more ionic groups (X), and (hydro)(fluoro)carbon groups having 1 to 24 carbon atoms and optionally containing one or more of H, O, and Cl (excluding groups having an ionic group (X)); R ｆ １ R may be the same or different in each occurrence and is a perfluoroalkylene group having 1 to 7 carbon atoms; ｆ ２ may be the same or different in each occurrence and are perfluoroalkylene groups having 1 to 11 carbon atoms and having one or more ionic groups (X); n1 and n2 are integers of 1 or greater; the ionic group (X) is -SO ３ Xａ , -PO ３ X ａ and -COOX ａ (X ａ is H, an ammonium group, or a monovalent metal; and

[0227] T in the formula Ｘ , T Ｘ’ , R ｆ １ , R ｆ ２ , n1 and n2 are combined so that the number average molecular weight falls within the above range.

[0228] In the general formula representing the polyfunctional fluoropolyether dispersant, the repeating unit -R ｆ １ -O- includes, for example, -CF ２ CF ２ O-, -CFYO-, -CF ２ CFYO-, -CF ２ O-, -CF ２ (CF ２ ) ｚ CF ２ O- (wherein Y is a fluoro(oxy)alkyl group having 1 to 5 carbon atoms; z is 1 or 2).

[0229] In the general formula representing the polyfunctional fluoropolyether dispersant, the repeating unit -R ｆ ２ -O- includes, for example, -CF ２ CF (G ｘ ) O-, -CF(G ｘ ) O-, -CF ２ (CF ２ ) ｘ１ CF (G ｘ ) (CF ２ ) ｘ２ O-(in the formula, G ｘ is a perfluoro(oxy)alkyl group having 1 to 5 carbon atoms and having one or more ionic groups (X), and X1 and X2 are independently integers of 0 to 3, with the proviso that the sum of X1 and X2 is 1 or more).

[0230] T ｘ and T Ｘ’ For example, -CFZ*-COOX ａ , -CFZ*CH ２ -COOX ａ or -CFZ*-CH ２ (OCH ２ CH ２ ) ｋ -COOX ａ (Wherein Z* is F or CF ３ k is an integer from 0 to 10; X ａ is H, an ammonium group, or a monovalent metal), a nonionic (per)fluoroalkyl group having 1 to 3 carbon atoms which may contain one or more of H, O, and Cl (for example, —CF ２ Cl, —CF ３ etc.), etc.

[0231] Examples of such polyfunctional fluoropolyether dispersants include dispersant (D) described in WO 2019 / 048394.

[0232] As the water-soluble fluorine-containing polymer, a fluoropolyether acid or a salt thereof can be used.

[0233] The fluoropolyether acid may be a fluoropolyether acid having a repeating unit represented by any one of formulas (11a) to (11d): (-CFCF ３ -CF ２ -O-) ｎ (11a) (-CF ２ -CF ２ -CF ２ -O-) ｎ (11b) (-CF ２ -CF ２ -O-) ｎ -(-CF ２ -O-) ｍ (11c) (-CF ２ -CFCF ３ -O-) ｎ -(-CF ２ -O-) ｍ(11d) (In the formula, m and n are integers of 1 or more.)

[0234] In the formula, m and n are integers of 1 or more, and are combined so that the number average molecular weight falls within the above-mentioned range.

[0235] Fluoropolyether acids can have an acid or acid salt group at one or both ends. For monofunctional fluoropolyether acids with an acid or acid salt group at one end, the other end of the molecule is usually perfluorinated but may contain a hydrogen or chlorine atom.

[0236] The fluoropolyether acid is preferably a carboxylic acid, a sulfonic acid, a sulfonamide, or a phosphonic acid, more preferably a carboxylic acid. Among the fluoropolyether acids or their salts, a salt of a fluoropolyether acid is preferred, an ammonium salt of a fluoropolyether acid is more preferred, and an ammonium salt of a fluoropolyether carboxylic acid is even more preferred.

[0237] Such fluoropolyether acids or salts thereof include those represented by the following formula: CF ３ -CF ２ -CF ２ -O(-CFCF ３ -CF ２ -O-) ｎ CFCF ３ -COOH, CF ３ -CF ２ -CF ２ -O(-CF ２ -CF ２ -CF ２ -O-) ｎ -CF ２ -CF ２ COOH or HOOC-CF ２ -O(-CF ２ -CF ２ -O-) ｎ -(-CF ２ -O-) ｍ CF ２ COOH (wherein m and n are the same as above) or a salt thereof is preferred.

[0238] Examples of the fluoropolyether acid or its salt include the fluoropolyether acids or its salts described in WO 2000 / 071590 and WO 2008 / 060461.

[0239] Although the embodiments have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims.

[0240] <1> According to the first aspect of the present disclosure, ４ and recovering the water-soluble fluoropolymer from the composition by mixing a cationic polymer with a composition containing a water-soluble fluoropolymer exceeding 1000 kJ / kg and water. <2> According to a second aspect of the present disclosure, there is provided a recovery method according to the first aspect, which comprises mixing the composition with the cationic polymer to form an aggregate containing the water-soluble fluoropolymer and the cationic polymer, and separating the water and the aggregate to recover the water-soluble fluoropolymer as the aggregate. <3> According to a third aspect of the present disclosure, there is provided a recovery method according to the first or second aspect, in which the cationic polymer is at least one selected from the group consisting of polyethyleneimine, poly(diallyldimethylammonium) and salts thereof, poly(trimethylaminoethyl methacrylate) and salts thereof, polydimethylaminoethyl methacrylate, dimethylamine-epichlorohydrin condensates, dicyandiamide-formalin condensates, and dicyandiamide-diethylenetriamine condensates. <4> According to a fourth aspect of the present disclosure, there is provided the method of recovering water-soluble fluoropolymers according to any one of the first to third aspects, wherein the amount of the cationic polymer is 1 to 10,000% by mass based on the mass of the water-soluble fluoropolymer. <5> According to a fifth aspect of the present disclosure, there is provided the method of recovering water-soluble fluoropolymers according to any one of the first to third aspects, wherein the number average molecular weight of the water-soluble fluoropolymer is 0.3×10 ４The recovery method according to any one of the first to fourth aspects is provided as described above. <6> According to a sixth aspect of the present disclosure, there is provided a recovery method according to any one of the first to fifth aspects, in which the water-soluble fluorine-containing polymer has an ionic group. <7> According to a seventh aspect of the present disclosure, there is provided a recovery method according to any one of the first to sixth aspects, in which the water-soluble fluorine-containing polymer is a polymer (I) containing polymerization units (I) based on a monomer (I) represented by general formula (I): General formula (I): CX １ X ３ =CX ２ R (-CZ １ Z ２ -A ０ ) ｍ (I) (wherein, X １ and X ３ are each independently F, Cl, H or CF ３ and X ２ is H, F, an alkyl group or a fluorine-containing alkyl group; A ０ is an anionic group; R is a linking group; Z １ and Z ２ are each independently H, F, an alkyl group, or a fluorine-containing alkyl group; and m is an integer of 1 or more.) <8> According to an eighth aspect of the present disclosure, ４A recovery method according to the seventh aspect is provided. <9> According to a ninth aspect of the present disclosure, there is provided a recovery method according to the seventh or eighth aspect, in which the ion exchange rate of polymer (I) is 53 or less. <10> According to a tenth aspect of the present disclosure, there is provided a recovery method according to any of the first to ninth aspects, in which the content of the water-soluble fluoropolymer in the composition is more than 0 mass % and 1 mass % or less, based on the mass of the composition. <11> According to an eleventh aspect of the present disclosure, there is provided a recovery method according to any of the first to tenth aspects, in which the recovery rate of the water-soluble fluoropolymer is 99.0 mass % or more. <12> According to a twelfth aspect of the present disclosure, the water-soluble fluoropolymer is at least one selected from the group consisting of a polymer (1) containing polymerized units (1) based on a monomer represented by general formula (1) and a polymer (2) containing polymerized units (2) based on a monomer represented by general formula (2), the content of polymerized units (1) in the polymer (1) being 90 mol% or more based on all polymerized units of the polymer (1), and the content of polymerized units (2) in the polymer (2) being 90 mol% or more based on all polymerized units of the polymer (2), and the number average molecular weight of the water-soluble fluoropolymer is 0.3 × 10 ４ ~20.0 x 10 ４ The present invention provides a recovery method according to any one of the first to eleventh aspects, wherein the content of the water-soluble fluoropolymer in the composition is 0.020 to 0.2% by mass, the cationic polymer is polyethyleneimine, and the amount of the cationic polymer is 30 to 500% by mass relative to the mass of the water-soluble fluoropolymer. ２ =CY(-CZ ２ -O-Rf-A) (1) (In the formula, X is the same or different and represents -H or F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Z is the same or different and represents -H, -F, an alkyl group or a fluoroalkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. A is -COOM, -SO ３ M, -OSO ３ M or -C(CF ３ )２ OM (M is -H, metal atom, -NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group.) CX ２ =CY(-O-Rf-A) (2) (wherein X may be the same or different and is -H or F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and having an ether bond or a keto group; A is -COOM, -SO ３ M, -OSO ３ M or -C(CF ３ ) ２ OM (M is -H, metal atom, -NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium, or optionally substituted phosphonium, and R ７ is H or an organic group.) <13> According to a thirteenth aspect of the present disclosure, there is provided a recovery method according to any of the first to twelfth aspects, comprising: mixing a composition containing the water-soluble fluorine-containing polymer and water with an inorganic flocculant; mixing a composition containing the water-soluble fluorine-containing polymer, water, and the inorganic flocculant with the cationic polymer; mixing a composition containing the water-soluble fluorine-containing polymer, water, the inorganic flocculant, and the cationic polymer with at least one selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers; generating a flocculate containing the water-soluble fluorine-containing polymer, the inorganic flocculant, the cationic polymer, and at least one selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers; and separating water from the flocculate.

[0241] Next, embodiments of the present disclosure will be described with reference to examples, but the present disclosure is not limited to these examples.

[0242] The values ​​in the examples were measured by the following methods.

[0243] <Molecular Weight of Water-Soluble Fluorine-Containing Polymer> The molecular weights of polymers 1 to 4 were measured by GPC.

[0244] <Concentration of Water-Soluble Fluorine-Containing Polymers> The concentrations of Polymers 1 to 4 were measured by liquid chromatography (LC) using a charged particle detector manufactured by Thermo Fisher Scientific as the detector.

[0245] <Concentration of Perfluorooctanoic Acid> The concentration of perfluorooctanoic acid was measured using liquid chromatography (LC) with a UV detector at a detection wavelength of 210 nm.

[0246] Example 1 CF with a number average molecular weight of 18,000 ２ = CFOCF ２ 5 g of a 10 wt% aqueous solution of polyethyleneimine was added to 1 L of an aqueous solution containing 1000 ppm by mass of a COOH homopolymer (polymer 1) while stirring. Immediately after the addition, a cloudy white solution was obtained, which was separated into solid and liquid using a centrifuge, and the liquid portion was measured by liquid chromatography (LC). As a result of the measurement, the concentration of polymer 1 was less than 1 ppm by mass. Therefore, it was found that polymer 1 could be recovered with a high recovery rate by recovering the solid portion.

[0247] Example 2 CF with a number average molecular weight of 15,000 ２ = CFOCF ２ CF ２ SO ３ To 1 L of an aqueous solution containing 1000 ppm by mass of a homopolymer of H (polymer 2), 4 g of a 10% by mass aqueous solution of polyethyleneimine was added with stirring. A cloudy white solution was obtained, and the solid and liquid were separated using a centrifuge, and the liquid portion was measured by LC. As a result of the measurement, the concentration of polymer 2 was less than 1 ppm by mass.

[0248] Example 3: To 1 L of an aqueous solution containing 430 ppm by mass of polymer 1 having a number average molecular weight of 18,000, 2 g of a 10 mass% aqueous solution of polyethyleneimine was added with stirring. Immediately after the addition, a cloudy white solution was obtained, which was separated into solid and liquid using a centrifuge, and the liquid portion was measured by LC. As a result of the measurement, the concentration of polymer 1 was less than 1 ppm by mass.

[0249] Example 4 1 g of a 10 mass % aqueous aluminum sulfate solution was added to 1 L of an aqueous solution containing 430 mass ppm of polymer 1 having a number average molecular weight of 18,000 and stirred, and then 2 g of a solution of Epomin P-1000 manufactured by Nippon Shokubai Co., Ltd., with the solids concentration adjusted to 10 mass %, was added and stirred for 1 minute. White flocs were generated, so the stirring was stopped and the mixture was allowed to stand for 1 hour to allow the flocs to settle. The supernatant was collected and the concentration of polymer 1 was measured by LC, and the concentration of polymer 1 was found to be less than 1 mass ppm.

[0250] Example 5 3 g of a 10 mass % aqueous aluminum sulfate solution was added to 1 L of an aqueous solution containing 860 mass ppm of polymer 2 having a number average molecular weight of 15,000 and stirred, and then 3 g of a solution of Epomin P-3000 manufactured by Nippon Shokubai Co., Ltd., adjusted to a solids concentration of 10%, was added and stirred for 1 minute. White flocs formed, so stirring was stopped and the mixture was allowed to stand for 1 hour to allow the flocs to settle. The supernatant was collected and the concentration of polymer 2 was measured by LC, and the concentration of polymer 2 was found to be less than 1 mass ppm.

[0251] Example 6: 2.5 g of a 10% by mass aluminum sulfate aqueous solution was added to 1 L of an aqueous solution containing 290 ppm by mass of polymer 2 having a number average molecular weight of 15,000, and the mixture was stirred. Then, 2.5 g of a solution containing Epomin P-3000 manufactured by Nippon Shokubai Co., Ltd., adjusted to a solids concentration of 10%, was added and stirred for 1 minute. The solution became cloudy, and no sedimentation occurred even after stopping the stirring and leaving it to stand for 1 hour. When 2 g of an aqueous solution containing an anionic polymer flocculant (Acofloc A-110 manufactured by MT Aquapolymer Co., Ltd.) adjusted to a concentration of 0.1% by mass was added to the solution and stirred, white flocs were generated. The stirring was stopped and the mixture was left to stand for 1 hour, allowing the flocs to settle. The supernatant was collected and the concentration of polymer 2 was measured by LC, resulting in a concentration of 1.9 ppm by mass.

[0252] Example 7: 3 g of a 10% by mass aluminum sulfate aqueous solution was added to 1 L of an aqueous solution containing 430 ppm by mass of polymer 2 having a number average molecular weight of 15,000, and the mixture was stirred. Then, 1 g of a solution of Epomin P-3000 manufactured by Nippon Shokubai Co., Ltd., with a solids concentration adjusted to 10%, was added and stirred for 1 minute. The solution became cloudy, and no sedimentation occurred even after stopping the stirring and leaving it to stand for 1 hour. When 0.05 g of an anionic polymer flocculant (Water Floc A-71 manufactured by Technica Co., Ltd.) was added to the solution and stirred, white flocs were generated. Stirring was stopped and the mixture was left to stand for 1 hour, allowing the flocs to settle. The supernatant was collected and the concentration of polymer 2 was measured by LC; the concentration of polymer 2 was found to be less than 1 ppm by mass.

[0253] Example 8 CF with a number average molecular weight of 5,300 ２ = CFOCF ２ CF ２ SO ３ To 1 L of an aqueous solution containing 1000 ppm by mass of a homopolymer of H (polymer 3), 4 g of a 10% by mass aqueous solution of polyethyleneimine was added with stirring. A cloudy white solution was obtained, and the solid and liquid were separated using a centrifuge, and the liquid portion was measured by LC. As a result of the measurement, the concentration of polymer 3 was 1.5 ppm by mass.

[0254] Example 9: 995 kg of an aqueous solution containing 630 ppm by mass of polymer 3 was placed in a 1000 L coagulation tank equipped with an agitator blade and stirred. 754 g of a 27% aqueous aluminum sulfate solution was added while stirring, and then 640 g of Epomin P-3000 manufactured by Nippon Shokubai Co., Ltd. was added to precipitate a solid. 15 g of Waterfloc L N-52B manufactured by Technica Co., Ltd. was added while stirring and stirred for 10 minutes. The liquid in the coagulation tank was supplied to a decanter-type centrifuge BDN006 manufactured by Tomoe Engineering Co., Ltd. using a Mohno Pump NEL16PUN manufactured by Heishin Soubi Co., Ltd., and solid-liquid separation was carried out at a centrifugal force of 2100 G. As a result, the concentration of polymer 3 in the separated water was less than 1 ppm by mass, the suspended solids (SS) concentration was 18 mg / L, and the water content of the sludge was 90% by mass.

[0255] Example 10 CH having a number average molecular weight of 122,000 ２ =CFCF ２ OCF (CF ３To 1 L of an aqueous solution containing 400 ppm of a homopolymer of 2,4-dimethylaminopropanediol (Dimethylaminopropanediol)-2,4-diol (Polymer 4), 1.4 g of a 10 mass % aqueous solution of polyethyleneimine was added with stirring. White flocs were generated, and the stirring was stopped and the mixture was allowed to stand for 1 hour to allow the flocs to settle. The supernatant was sampled and the concentration of Polymer 4 was measured by LC. The concentration of Polymer 4 was found to be less than 1 mass ppm.

[0256] Comparative Example 1 A total of 20 g of an aqueous solution containing an anionic polymer flocculant (Acofloc A-110, manufactured by MT Aquapolymer Co., Ltd.) adjusted to a concentration of 1% by mass was added in five 4 g portions to 1 L of a solution containing 430 ppm by mass of polymer 1 having a number average molecular weight of 18,000 while stirring. During the addition of 4 g to 20 g, the solution remained colorless and transparent, and no precipitate was observed. After 20 g was added, stirring was stopped, and the solution was allowed to stand for 1 hour, after which no precipitate was observed.

[0257] Comparative Example 2 A total of 20 g of an aqueous solution containing a nonionic polymer flocculant (Orflock ON-1H, manufactured by Organo Corporation) adjusted to a concentration of 1% by mass was added in five 4 g portions with stirring to 1 L of a solution containing 430 ppm by mass of polymer 1 having a number average molecular weight of 15,000. During the addition of 4 g to 20 g, the solution remained colorless and transparent, and no precipitate was observed. After 20 g was added, stirring was stopped, and the solution was allowed to stand for 1 hour, and no precipitate was observed.

[0258] To 1 L of a solution containing 1,000 ppm by mass of polymer 1 having a number average molecular weight of 15,000, 10 g of a 10% by mass aqueous aluminum sulfate solution was added, and the mixture was neutralized with stirring with a 1 mol / L aqueous sodium hydroxide solution until the pH reached 8. A white translucent precipitate was observed, and after allowing to stand for 1 hour, the supernatant was collected and the polymer 1 concentration was measured by LC, resulting in a polymer 1 concentration of 640 ppm by mass.

[0259] Comparative Example 4: 6 g of a 10% by weight aqueous solution of polyethyleneimine was added to 1 L of a solution containing 1000 ppm by weight of perfluorooctanoic acid, and the mixture was stirred for 1 minute. A cloudy solution was obtained, and the solid and liquid were separated using a centrifuge. The liquid portion was measured by LC. As a result of the measurement, the concentration of perfluorooctanoic acid was 99 ppm by weight.

Claims

1. Number average molecular weight is 0.1 x 10 ４ A method for recovering a water-soluble fluoropolymer, comprising mixing a composition containing a water-soluble fluoropolymer having a molecular weight of more than 1000 and water with a cationic polymer, and recovering said water-soluble fluoropolymer from said composition.

2. The method for recovering the water-soluble fluoropolymer according to claim 1, comprising mixing the composition with the cationic polymer to produce an agglomerate containing the water-soluble fluoropolymer and the cationic polymer, and separating the agglomerate from water, thereby recovering the water-soluble fluoropolymer as the agglomerate.

3. The method according to claim 1 or 2, wherein the cationic polymer is at least one selected from the group consisting of polyethyleneimine, poly(diallyldimethylammonium) and its salts, poly(trimethylaminoethyl methacrylate) and its salts, polydimethylaminoethyl methacrylate, dimethylamine-epichlorohydrin condensates, dicyandiamide-formalin condensates, and dicyandiamide-diethylenetriamine condensates.

4. The method according to any one of claims 1 to 3, wherein the amount of said cationic polymer is 1 to 10,000% by mass based on the mass of said water-soluble fluoropolymer.

5. The number average molecular weight of the water-soluble fluorine-containing polymer is 0.3 × 10 ４ The method for recovering the above-mentioned compound according to any one of claims 1 to 4.

6. The method according to any one of claims 1 to 5, wherein the water-soluble fluorine-containing polymer has an ionic group.

7. The method according to any one of claims 1 to 6, wherein the water-soluble fluorine-containing polymer is a polymer (I) containing polymerization units (I) based on a monomer (I) represented by general formula (I): General formula (I): CX １ X ３ = C.X. ２ R (-CZ １ Z ２ -A ０ ) ｍ (I) (wherein, X １ and X ３ are each independently F, Cl, H or CF ３ and X ２ is H, F, an alkyl group or a fluorine-containing alkyl group; A ０ is an anionic group; R is a linking group; Z １ and Z ２ are each independently H, F, an alkyl group or a fluorine-containing alkyl group; and m is an integer of 1 or more.

8. The number average molecular weight of the polymer (I) is 0.3×10 ４ The method for recovering the above-mentioned material according to claim 7.

9. The method for recovering polymer (I) according to claim 7 or 8, wherein the ion exchange rate of polymer (I) is 53 or less.

10. The method according to any one of claims 1 to 9, wherein the content of the water-soluble fluorine-containing polymer in the composition is more than 0 mass % and 1 mass % or less, based on the mass of the composition.

11. The method according to any one of claims 1 to 10, wherein the recovery rate of the water-soluble fluoropolymer is 99.0 mass % or more.

12. The water-soluble fluoropolymer is at least one selected from the group consisting of a polymer (1) containing polymerization units (1) based on a monomer represented by general formula (1) and a polymer (2) containing polymerization units (2) based on a monomer represented by general formula (2), the content of polymerization units (1) in the polymer (1) is 90 mol % or more based on the total polymerization units of the polymer (1), the content of polymerization units (2) in the polymer (2) is 90 mol % or more based on the total polymerization units of the polymer (2), and the number average molecular weight of the water-soluble fluoropolymer is 0.3×10 ４ ~20.0 x 10 ４ The method according to any one of claims 1 to 11, wherein the content of the water-soluble fluoropolymer in the composition is 0.020 to 0.2% by mass, the cationic polymer is polyethyleneimine, and the amount of the cationic polymer is 30 to 500% by mass relative to the mass of the water-soluble fluoropolymer. ２ = CY (-CZ ２ -O-Rf-A) (1) (In the formula, X is the same or different and is -H or F; Y is -H, -F, an alkyl group or a fluorine-containing alkyl group; Z is the same or different and is -H, -F, an alkyl group or a fluoroalkyl group. Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having 2 to 100 carbon atoms and an ether bond. A is -COOM, -SO ３ M, -OSO ３ M or -C(CF ３ ) ２ OM (M is -H, a metal atom, -NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium; R ７ is H or an organic group. ２ ═CY(—O—Rf-A) (2) (wherein X is the same or different and is —H or F; Y is —H, —F, an alkyl group or a fluorine-containing alkyl group; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having an ether bond or a keto group having 2 to 100 carbon atoms. A is —COOM, —SO ３ M, -OSO ３ M or -C(CF ３ ) ２ OM (M is -H, a metal atom, -NR ７ ４ , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium; R ７ is H or an organic group.

13. The method for recovering water according to any one of claims 1 to 12, comprising the steps of: mixing a composition containing the water-soluble fluorine-containing polymer and water with an inorganic flocculant; mixing a composition containing the water-soluble fluorine-containing polymer, water and the inorganic flocculant with the cationic polymer; mixing a composition containing the water-soluble fluorine-containing polymer, water, the inorganic flocculant and the cationic polymer with at least one selected from the group consisting of anionic polymers, nonionic polymers and amphoteric polymers; generating a flocculant containing the water-soluble fluorine-containing polymer, the inorganic flocculant, the cationic polymer and at least one selected from the group consisting of anionic polymers, nonionic polymers and amphoteric polymers; and separating water from the flocculant.

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