Method for recovering water-soluble fluoropolymer

Abstract

To provide a recovery method capable of recovering water-soluble fluorine-containing polymers at a high recovery rate.SOLUTION: There is provided a method for recovering water-soluble fluorine-containing polymers in which compositions containing water-soluble fluorine-containing polymers with an average molecular weight exceeding 0.1×104 and water with cationic polymers to recover the water-soluble fluorine-containing polymers from the compositions.SELECTED DRAWING: None

Description

[Technical field]

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

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

[0003] Patent Document 2 describes a water treatment method comprising a removal step of removing a polymer (I) from water containing the polymer (I) including polymerization 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) (In the formula, X 1 and X 3 are each independently F, Cl, H or CF 3 ;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. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-519976 A [Patent Document 2] International Publication No. 2020 / 218621 Summary of the Invention [Problem to be solved by the invention]

[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. [Means for solving the problem]

[0006] According to the present disclosure, the number average molecular weight is 0.1×10 4 The present invention provides a method for recovering a water-soluble fluoropolymer, which comprises mixing a composition containing a water-soluble fluoropolymer having a molecular weight of more than 1000 and water with a cationic polymer, and recovering the water-soluble fluoropolymer from the composition. Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a recovery method capable of recovering a water-soluble fluoropolymer at a high recovery rate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 0.1×10 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 4 A composition containing a water-soluble fluoropolymer and water of above 100% purity is mixed with a cationic polymer, and the water-soluble fluoropolymer is recovered from the composition. By using this method, an aggregate containing the water-soluble fluoropolymer and the cationic polymer can be produced, and by separating the water and the aggregate, the water-soluble fluoropolymer can be recovered as the aggregate, and further, water of high purity can also be recovered.

[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, and Unisense FPA100L, KHE104L, KHF11L, and KHP10P manufactured by Senka Corporation.

[0016] As the cationic polymer, among them, 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 enables the water-soluble fluorine-containing polymer to be recovered at an even higher recovery rate, and polyethyleneimine is more preferred.

[0017] (Mixing process) 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 1.0% by mass or less, based on 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, based on 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, based on 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, 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, WO 2014 / 09225, WO 2015 / 09226, WO 2016 / 09228, WO 2017 / 09229, WO 2019 / 09229, WO 2018 / 09229, WO 2019 ... Measurement methods for each polymer are described in Publication No. 2012 / 082707, International Publication No. 2012 / 082703, International Publication No. 2012 / 082451, International Publication No. 2006 / 135825, International Publication No. 2004 / 067588, International Publication No. 2009 / 068528, JP 2004-075978 A, JP 2001-226436 A, International Publication No. 1992 / 017635, International Publication No. 2014 / 069165, JP 11-181009 A, etc. As a method for measuring the content of the 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 quantified 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 quantitate by LC.

[0021] As a 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, CAD, and MS being more preferred, with CAD and MS being even more preferred, and MS being most preferred.

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

[0023] The mobile phase is preferably water or a mixed solvent 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] In cases where the water-soluble fluoropolymer is adsorbed to the metal material of the LC flow path, reducing quantitative performance and sensitivity, the use of an ion pair reagent can improve quantitative performance and sensitivity. Triethylamine (TEA) or N,N-diisopropylethylamine (DIPEA) is preferred as the ion pair reagent, and hexafluoro-2-propanol is preferred as the 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 by a pH meter (eg, 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. There are no limitations on the pH adjuster, and for example, an acid compound or an alkaline compound can be used. Examples of acid compounds include hydrochloric acid (HCl), nitric acid (HNO 3 ), sulfuric acid (H 2 SO 4 ), phosphoric acid (H 3 PO 4 ), and preferably hydrochloric acid (HCl) or nitric acid (HNO 3 ) Examples of the alkali compounds include hydroxides of alkali metals such as NaOH and KOH; Mg(OH) 2 , Ca(OH) 2 Examples include hydroxides of alkaline earth metals such as sodium hydroxide; 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 performed 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. In addition, 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 ion, hydroxide ion, fluorine ion, nitrate ion, and chloride ion, more preferably at least one selected from the group consisting of sulfate ion and chloride ion, and even more preferably sulfate ion.

[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 mass% relative to the mass of the water-soluble fluoropolymer, more preferably 1.0 mass% or more, even more preferably 10 mass% or more, still more preferably 30 mass% or more, more preferably 300 mass% or less, and still more preferably 100 mass% or less.

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

[0039] The mixing of the composition with at least one selected from the group consisting of anionic polymer, nonionic polymer and amphoteric polymer may be carried out simultaneously with the mixing of the composition with cationic polymer, or may be carried out before the mixing of the composition with cationic polymer, or may be carried out after the mixing of the composition with cationic polymer. Among them, it is preferable to mix the composition with at least one selected from the group consisting of anionic polymer, nonionic polymer and amphoteric polymer after the mixing of the composition with cationic polymer.

[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 further preferably 1,000,000 or more.

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

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

[0043] Commercially available anionic polymers include Floclan A1210 manufactured by Katayama Nalco; Takifloc A-102, A-103, A-177T, A-108T, A-142, and A-50 manufactured by Taki Chemical Industry; Acofloc A-95, A-110, and A-150 manufactured by MT Aquapolymer; Sumifloc FA-40 and FA-50 manufactured by MT Aquapolymer; 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 used in the recovery method of the present disclosure is preferably 0.001 to 50 mass %, more preferably 0.004 mass % or more, even more preferably 0.010 mass % or more, more preferably 30 mass % or less, and even more preferably 20 mass % or less, based on 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 Acofloc N-100, N-102, and N-104 manufactured by MT Aquapolymer Co., Ltd., Orfloc ON-1H, ON-2, ON-3, and N-1 manufactured by Organo Corporation, and Waterfloc L N-52B manufactured by Technica Co., Ltd.

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

[0048] As the amphoteric polymer, a polymer commercially available as an amphoteric polymer flocculant can be used, 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 used in the recovery method of the present disclosure is preferably 0.001 to 50 mass %, more preferably 0.004 mass % or more, even more preferably 0.010 mass % or more, more preferably 30 mass % or less, and even more preferably 20 mass % or less, based on the mass of the water-soluble fluoropolymer.

[0051] In one embodiment of the recovery method of the present disclosure, A composition containing a water-soluble fluorine-containing polymer and water is mixed with an inorganic flocculant, A composition containing a water-soluble fluorine-containing polymer, water and an inorganic flocculant is mixed with a cationic polymer; A composition containing a water-soluble fluorine-containing polymer, water, an inorganic flocculant and a cationic polymer is mixed with at least one polymer selected from the group consisting of an anionic polymer, a nonionic polymer and an amphoteric polymer, forming a flocculant containing a water-soluble fluorine-containing polymer, an inorganic flocculant, a cationic polymer, and at least one polymer selected from the group consisting of an anionic polymer, a nonionic polymer, and an amphoteric polymer; Separating the water and the condensate By this, the water-soluble fluoropolymer can be recovered as an agglomerate.

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

[0053] In the recovery method of the present disclosure, the composition is mixed with a cationic polymer to produce an agglomerate containing the water-soluble fluoropolymer and the cationic polymer, and the agglomerate is separated from the water, thereby recovering the water-soluble fluoropolymer as the agglomerate.

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

[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] In addition, 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 mass ppm or less, more preferably 10 mass ppm or less, and even more preferably less than 1 mass ppm, based on the water. The content of the water-soluble fluoropolymer contained in the water is determined by the same measurement method as that for the content of the water-soluble fluoropolymer in the composition.

[0057] (Composition containing water-soluble fluorine-containing polymer 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 may 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 non-fluorine-containing polymer, a compound having a molecular weight of 1000 or less, etc.

[0059] Examples of compounds having a molecular weight of 1000 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, with no particular lower limit and which may be 0 mass%.

[0061] The composition to be subjected to the recovery method of the present disclosure may contain other polymers other than the water-soluble fluorine-containing polymer. The other polymers may be water-soluble or water-insoluble, and usually have no ionic groups or a limited number of ionic groups that result in an ion exchange rate higher than about 100. The ion exchange rate of the other polymers 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, perfluoro(alkyl vinyl ether), etc., hydrocarbon olefins such as ethylene, propylene, isobutene, etc., alkyl vinyl ether, etc.) (for example, tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (PFA), ethylene-tetrafluoroethylene copolymer (ETFE), etc.); polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and ethylene-chlorotrifluoroethylene (ECTFE), etc.).

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

[0065] The composition to be subjected to the recovery method of the present disclosure may be, for example, wastewater generated in industrial production. That is, the composition to be subjected to the recovery method of the present disclosure may be wastewater. The composition to be subjected to the recovery method of the present disclosure may be a composition generated in a polymer production process. The composition to be 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 fluorine-containing polymer and water.

[0066] The composition produced in the polymer production process may include a composition produced in a polymerization process in which one or more monomers are polymerized, a composition produced in a pretreatment process before the polymerization process (e.g., a process for preparing an emulsifier at a predetermined concentration, etc.), and a composition produced in a post-treatment process after the polymerization process (e.g., a process for concentrating an aqueous dispersion, a solid-liquid separation process, a coagulation process, a washing process, a dehydration process, a drying process, a heat treatment process, etc.). The composition produced in the polymerization process may include an aqueous solution, a dispersion, a liquid obtained by liquefying a gas, and the like. Furthermore, the composition produced in the polymerization process may include a composition produced directly in the polymerization process, as well as a composition obtained by treating the composition produced directly in the polymerization process by a method such as filtration, distillation, concentration, dilution, etc.

[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 compounds 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 (wherein 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 General formula (110):CF 2 =CF-ORf 111 (In the formula, Rf 111 represents a perfluoro organic group; General formula (120):CF 2 =CF-OCH 2-Rf 121 (In the formula, Rf 121 is a perfluoroalkyl group having 1 to 5 carbon atoms), General formula (130):CF 2 =CFOCF 2 ORf 131 (In the formula, 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, General formula (140):CF 2 =CFO(CF 2 CF(Y 141 )O) m (CF 2 ) n F (In the formula, 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. General formula (150):CF 2 =CF-O-(CF 2 CFY 151 -O) n -(CFY 152 ) m -A 151 (In the formula, Y 151 is a fluorine atom, a chlorine atom, -SO 2 It represents a F group or a perfluoroalkyl group. A perfluoroalkyl group is an ether-type oxygen and -SO 2 F group. n represents an integer of 0 to 3. n Y 151 may be the same or different. Y 152 is a fluorine atom, a chlorine atom or -SO 2 F group; m represents an integer of 1 to 5; m Y 152 may be the same or different. A 151 -SO 2 X 151 , -COZ 151 or -POZ152 Z 153 Represents X. 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, -NR 154 R 155 -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. etc.

[0069] (Water-soluble fluorine-containing polymer) In the recovery method of the present disclosure, the number average molecular weight is 0.1 × 10 4 The water-soluble fluoropolymer is recovered from a composition containing a water-soluble fluoropolymer having a number average molecular weight of more than 1000 and water. The recovery method of the present disclosure is aimed at recovering 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 to use a cationic polymer in order to recover a water-soluble fluoropolymer having a relatively high molecular weight.

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

[0071] The water-soluble fluorine-containing polymer may be one in which the ratio of hydrogen atoms bonded to carbon atoms substituted with fluorine atoms is 50% or more. The "ratio of hydrogen atoms bonded to carbon atoms substituted with fluorine atoms" is calculated as the ratio 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 4 The number average molecular weight of the water-soluble fluoropolymer is 0.2×10 or more, because the water-soluble fluoropolymer can be recovered at a higher recovery rate. 4 Above, 0.3×10 4 Above, 0.4×10 4 Above, 0.5 x 10 4 That's it, 1.0 x 10 4 That's it, 3.0 x 10 4 or more, or 3.1×10 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 Less than or equal to 20.0 x 10 4 It is preferable that:

[0073] The weight average molecular weight of the water-soluble fluoropolymer is 0.2×10 4 Above, 0.4×10 4 Above, 0.6×10 4 Above, 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 25.0×10 4 The weight average molecular weight of the water-soluble fluorine-containing polymer is preferably 150.0×10 or more. 4Below, 100.0 x 10 4 Below, 60.0 x 10 4 Below, 50.0 x 10 4 Less than or equal to 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 fluorine-containing polymer 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 fluorine-containing polymer 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 fluorine-containing polymer 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 is calculated from the composition of the water-soluble fluoropolymer.

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

[0080] The water-soluble fluoropolymer preferably comprises an ionic group having a pKa of less than 10, more preferably less than 7. The ionic group of the water-soluble fluoropolymer is 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 to 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 the 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 the general formula (I). General formula (I):CX 1 X 3 =CX 2 R(-CZ 1 Z 2 -A 0 ) m (I) (In the formula, X 1 and X 3are each independently F, Cl, H or CF 3 ;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 the like, as well as acid groups such as -COOH, -COONH 4 The anionic group includes a functional group that provides an anionic group, such as an acid salt 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; R 7 is H or an organic group.

[0084] R is a linking group. In the present disclosure, the "linking group" is a (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 esters, amides, sulfonamides, carbonyls, carbonates, urethanes, ureas, and carbamates. 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, the hydrogen atom bonded to the carbon atom may be replaced with a halogen 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 either 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 atom, a hydrocarbon group in which some of the hydrogen atoms bonded to the carbon atom are substituted with fluorine atoms, or a hydrocarbon group in which all of the hydrogen atoms bonded to the carbon atom 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 be independently 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 represented by the general formula (r1): -CF 2 -O-(CX 6 2 ) e -{O-CF(CF 3 )} f -(O) g - (r1) (In the formula, X 6 are each independently H, F or CF 3 wherein 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) (In the formula, X 7 are each independently H, F or CF 3where e is an integer of 0 to 3, and g is 0 or 1) is more preferred.

[0095] A specific example of 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 -, -CF 2 -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 2Among them, 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 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) (In the formula, X 6 are each independently H, F or CF 3 where e is an integer from 0 to 3, f is an integer from 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 CF3 is more preferred, with one being F and the other being CF 3 It is even more preferable that:

[0097] In addition, in the general formula (I), -R-CZ 1 Z 2 - is represented by the general formula (s2): -CF 2 -O-(CX 7 2 ) e -(O) g -CZ 1 Z 2 - (s2) (In the formula, X 7 are each independently H, F or CF 3 where e is an integer from 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, with one being F and the other being CF 3 It is even more preferable that:

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

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

[0100] The monomer (I) and the polymer (I) each have an anionic group (A 0 ), it is also preferable that the compound has a C-F bond and does not have a C-H bond. That is, in the general formula (I), 1 , X 2 , and X 3 are all F, and R is preferably a perfluoroalkylene group having 1 or more carbon atoms, and the perfluoroalkylene group may be either linear or branched, may be either cyclic or noncyclic, 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, -SO 2 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 OM. Among them, -SO 3 M, -OSO 3 M, -COOM, -P(O)(OM) 2 or -C(CF 3 ) 2 OM is preferred, -COOM, -SO 3 M, -OSO 3 M, -P(O)(OM) 2 or -C(CF 3 ) 2 OM is more preferred, -SO 3 M, -COOM or -P(O)(OM) 2 More preferably, -SO 3 Particularly preferred is -M or -COOM.

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

[0104] The metal atom includes alkali metals (Group 1), alkaline earth metals (Group 2), etc., 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 More preferably, -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.

[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 also preferably a monomer represented by the general formula (Ia). The polymer (I) is also preferably a polymer containing a polymer unit (Ia) based on a monomer represented by the general formula (Ia). CF 2 =CF-O-Rf 0 -A 0 (Ia) (In the formula, 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 also preferably a monomer represented by the general formula (Ib). The polymer (I) is also preferably a polymer containing polymerized units (Ib) based on a monomer represented by the general formula (Ib). CH 2=CH-O-Rf 0 -A 0 (Ib) (In the formula, A 0 is an anionic group, and Rf 0 is a perfluorinated divalent linking group defined by formula Ia.

[0109] In the general formula (I), A 0 is a sulfate group. 0 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, in which R' is H or an alkyl group having 1 to 4 carbon atoms, and M is the same as above.

[0110] A 0 When is a sulfate group, examples of the monomer represented by the 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), C.H. 2 =CH(O(CF 2 ) 4 CH 2 OSO 3 M), CF 2 =CF(OCF2 CF 2 SO 2 N(CH 3 )CH 2 CH 2 OSO 3 M), C.H. 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), C.H. 2 =CH(OCF 2 CF 2 CF 2 CH 2 OSO 3 In the above formula, M is the same as above.

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

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

[0113] In the general formula (I), A 0 In one preferred embodiment, A is a carboxylate group. 0 For example, COOM or SO 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 formula (I) is 2 =CF(OCF 2 CF 2 COOM), CF 2 =CF(O(CF 2 ) 3 COOM), CF 2 =CF(O(CF 2 ) 4 COOM), CF 2 =CF(O(CF 2 ) 5 COOM), CF 2 =CF(OCF 2 CF(CF 3 )COOM), CF 2=CF(OCF 2 CF(CF 3 )O(CF 2 ) 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 2 NR'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 the general formula (I), A 0 In one preferred embodiment, A is a phosphate group. 0 For example, -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 In the formula, R' is an alkyl group having 1 to 4 carbon atoms, and M is the same as above.

[0115] A 0 When is a phosphate, the monomer represented by the 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 2CF(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 the general formula (I), A 0 In one preferred embodiment, A is a phosphonate group. 0 is a phosphonate group, the monomer represented by 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 2CF(CF 3 )P(O)(OM) 2 ), CF 2 =CF(OCF 2 CF(CF 3 )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 ) in which M is the same as above.

[0117] The monomer (I) is preferably a monomer (1) represented by general formula (1). The polymer (I) is preferably a polymer (1) containing polymerization units (1) based on a monomer represented by general formula (1). CX 2 =CY(-CZ 2 -O-Rf-A) (1) (In the formula, 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; Z may be 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 having 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; R 7is 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 a copolymer with other monomers.

[0119] The above-mentioned 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 contains an ether bond between carbon atoms.

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

[0121] In the 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 less carbon atoms, more preferably four or less, and even more preferably three or less. 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 less carbon atoms, more preferably four or less, and even more preferably three or less. The Y is -H, -F or CF 3 is preferred, with -F being more preferred.

[0122] In general formula (1), Z may be the same or different and is -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 less carbon atoms, more preferably four or less, and even more preferably three or less. 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 less carbon atoms, more preferably four or less, and even more preferably three or less. The Z may be -H, -F or CF 3 is preferred, with -F being more preferred.

[0123] In the 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), the above 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 2The above fluorine-containing alkylene group is preferably a perfluoroalkylene group.

[0126] 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, 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: [ka] (In the formula, Z 1 is F or CF 3 ;Z 2 and Z 3 are H or F;Z respectively 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 of 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 CF2 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 above-mentioned 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; R 7 is H or an organic group).

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

[0130] The metal atom includes alkali metals (Group 1), alkaline earth metals (Group 2), etc., 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, H, Na, K or NH 4 is even more preferred, H, Na or NH 4 is particularly preferred, H or NH 4 is most preferred.

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

[0133] The monomer represented by the general formula (1) may, for example, be 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) is exemplified.

[0134] In general formula (1a), n5 is preferably 0 or an integer from 1 to 5, more preferably 0, 1 or 2, and even more preferably 0 or 1, because 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 units (1) are preferably polymerized units (1A) based on a monomer represented by general formula (1A). CH 2 =CF(-CF 2 -O-Rf-A) (1A) (In the formula, Rf and A are the same as 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 those represented by the general formula:

[0139] [ka]

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

[0141] [ka]

[0142] The following are preferred, among which:

[0143] [ka]

[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), 2 =CFCF 2 OCF(CF 3 )COOM is more preferred.

[0146] Further, examples of the monomer represented by the general formula (1) include the 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, [ka] etc.

[0148] The monomer (I) is also preferably a monomer (2) represented by the general formula (2). The polymer (I) is also preferably a polymer (2) containing polymerized units (2) based on a monomer represented by general formula (2). CX 2 =CY(-O-Rf-A) (2) (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; 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; 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 X's may be -F, or at least one X may be -H. For example, one X may be -F and the other -H, or both X's may be -H.

[0151] In the 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 less carbon atoms, more preferably four or less, and even more preferably three or less. 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 less carbon atoms, more preferably four or less, and even more preferably three or less. Y is -H, -F or -CF 3 is preferred, with -F being more preferred.

[0152] In the 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 include a structure in which an oxygen atom is at the terminal and contains an ether bond between carbon atoms.

[0154] The carbon number of the fluorine-containing alkylene group of Rf is preferably 2 or more. Also, the carbon number is preferably 30 or less, more preferably 20 or less, further preferably 10 or less, and particularly preferably 5 or less. The fluorine-containing alkylene group is, for example, -CF 2 -, -CH 2 CF2 -, -CF 2 CF 2 -, -CF 2 CH 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: [ka] (In the formula, Z 1 is F or CF 3 ;Z 2 and Z 3 are H or F;Z respectively 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 )OCF2 CF 2 -,-CF 2 CF(CF 3 )OCF 2 CF 2 CF 2 -,-CF(CF 3 )CF 2 -O-CF(CF 3 )-,-(CF(CF 3 )CF 2 -O) n -CF(CF 3 )-(where 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 -(where n is an integer from 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 above-mentioned fluorine-containing alkylene group having an ether bond is preferably a perfluoroalkylene group.

[0157] The carbon number of the fluorine-containing alkylene group having a keto group is preferably 3 or more. The carbon number of 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 -CF 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 above-mentioned 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. The fluorine-containing alkylene group in which water is added to the keto group is, for example, -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 formulae (2a), (2b), (2c), (2d), (2e), (2f) and (2g). CF 2 =CF-O-(CF 2 ) n1 -A (2a) (In the formula, 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) (In the formula, n2 represents an integer of 1 to 5, and A is as defined above.) CF 2 =CF-O-(CFX 1 ) n3 -A (2c) (In the formula, X 1 is F or CF 3 n3 represents an integer of 1 to 10, and A is as defined above. CF 2 =CF-O-(CF 2 CFX 1 O) n4 -(CF 2 ) n6 -A (2d) (In the formula, 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 above definition.) CF 2 =CF-O-(CF 2 CF 2 CFX 1 O) n5 -CF 2 CF 2 CF 2 -A (2e) (In the formula, n5 represents an integer of 0 to 10; A and X 1 is the same as the above definition.) CF 2 =CF-O-(CF 2 ) n7 -O-(CF 2 ) n8 -A (2f) (In the formula, 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) (In the formula, 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), the above n1 is preferably an integer of 5 or less, and more preferably an integer of 2 or less.

[0162] The monomer represented by the general formula (2a) is, for example, CF 2 =CF-O-CF 2 COOM, C.F. 2 =CF(OCF 2 CF 2 COOM), CF 2 =CF(O(CF 2 ) 3 COOM), CF 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 3M (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, the above A is preferably -COOM, and the above M is preferably H, Na or NH 4 It is preferable that:

[0165] In the general formula (2d), X 1 In 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] The monomer represented by the general formula (2d) is, for example, 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(CF3 )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] The monomer represented by the general formula (2e) is, for example, CF 2 =CFOCF 2 CF 2 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] The monomer represented by the general formula (2f) is, for example, 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] The monomer represented by the general formula (2g) is, for example, CF 2 =CFO(CF 2 ) 2 OCF(CF 3 )COOM, CF 2 =CFOCF 2 CF 2 OCF(CF 3 )CF 2 OCF(CF 3 )COOM, CF 2 =CFOCF 2 CF(CF 3 )OCF 2 CF 2 OCF(CF 3 )COOM, CF 2 =CF[OCF 2 CF(CF 3 )] 2 O(CF 2 ) 2 O[CF(CF 3 )CF 2 O]CF(CF 3 )COOM, CF 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 also preferably a monomer (3) represented by the general formula (3). The polymer (I) is also preferably a polymer (3) containing polymerization units (3) based on a monomer represented by general formula (3). CX 2 =CY(-Rf-A) (3) (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; Rf is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having an ether bond having 2 to 100 carbon atoms; 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 include 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 a carbon number of 1 to 40. 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-(CF 2 ) n1 -A (3a) (wherein n1 represents an integer of 1 to 10, and A is as defined above), and a monomer represented by 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 preferable.

[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 4R is preferably an optionally substituted imidazolium, an optionally substituted pyridinium, or an 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 H or NH 4 It is preferable that:

[0180] The monomer represented by the general formula (3a) is, for example, 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 the 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 configuration in which m in general formula (I) is an integer of 2 or more will be described.

[0183] It is also preferable 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 preferable 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 -OQ F1 -CF(-Q F2 -CZ 1 Z 2 -A) 2 (4a) (In the formula, Z 1 , Z 2 and A is the same as above, Q F1 and QF2 are the same or different and each is 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. CF 2 =CF-OQ F1 -CF(-Q F2 -CZ 1 Z 2 -A) 2 (4b) (In the formula, Z 1 , Z 2 , A, Q F1 and Q F2 is the same as above)

[0184] As the monomers represented by the general formula (4a) and the general formula (4b), [ka] etc.

[0185] As the monomer (I), at least one selected from the group consisting of the monomer (1), the monomer (2) and the monomer (3) is preferable, the monomer (1) or the monomer (2) is more preferable, and the monomer (2) is even more preferable. 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 polymerization unit (I), or may be a copolymer containing the polymerization unit (I) and a polymerization 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 polymerization unit (I) is preferred. The polymerization unit (I) may be the same or different in each occurrence, and the polymer (I) may contain polymerization 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-isomer), CHF=CHCF 3 (Z form), 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 polymerization units based on the other monomer are preferably polymerization units based on tetrafluoroethylene. The polymerization units based on the other monomer may be the same or different in each occurrence, and the polymer (I) may contain polymerization units based on two or more different kinds of other monomers.

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

[0190] [ka]

[0191] (In the formula, X 1 , X 2 are the same or different H or F;X 3 are H, F, Cl, and 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. Rf 3 is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having ether bonds having 2 to 100 carbon atoms).

[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 (In the formula, Rf 3 is the same as the above formula (n1-2)).

[0193] As the other monomer, there may be mentioned a monomer represented by the formula (n2-1):

[0194] [ka]

[0195] (In the formula, X 9 is H, F or CH 3 ;Rf 4 Also included are fluorine-containing acrylate monomers represented by Rf (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). 4 The base is

[0196] [ka]

[0197] (wherein d3 is an integer of 1 to 4; e3 is an integer of 1 to 10), etc. can be mentioned.

[0198] As the other monomer, there may be mentioned a monomer represented by the formula (n2-2): CH 2 =CHO-Rf 5 (n2-2) (In the formula, Rf 5 Also included are fluorine-containing vinyl ethers represented by the formula (I) (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).

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

[0200] [ka]

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

[0202] More specifically,

[0203] [ka]

[0204] etc.

[0205] Others, general formula (n2-3): CH 2 =CHCH 2 O-Rf 6 (n2-3) (In the formula, Rf 6 is a fluorine-containing alkyl group having 1 to 40 carbon atoms or a fluorine-containing alkyl group having an ether bond having 2 to 100 carbon atoms), a fluorine-containing allyl ether represented by the general formula (n2-4): CH 2=CH-Rf 7 (n2-4) (In the formula, Rf 7 Also included are fluorine-containing vinyl monomers represented by the formula (I) being 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.

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

[0207] [ka]

[0208] and the like monomers.

[0209] The polymer (I) usually has a terminal group. The terminal group is a terminal group generated during polymerization, and representative 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 the formation of the polymer (I), or are generated during the chain transfer reaction.

[0210] In the polymer (I), the content of the polymerized units (I) 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 relative to the total polymerized units. 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 the polymerization units based on other monomers copolymerizable with the monomer represented by the 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 the total polymerization units. It is particularly preferable that the content of the polymerization units based on other monomers copolymerizable with the monomer represented by the general formula (I) is substantially 0 mol%, and it is most preferable that the polymer (I) does not contain any polymerization units based on other monomers.

[0212] In the polymer (1), polymer (2) or polymer (3), the content of the polymerization unit (1), polymerization unit (2) or polymerization unit (3) 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 relative to the total polymerization units. It is particularly preferable that the content of the polymerization unit (1), polymerization unit (2) or polymerization unit (3) is substantially 100 mol%, and it is most preferable that the polymer (1), polymer (2) or polymer (3) is composed only of the polymerization unit (2) or polymerization unit (3).

[0213] In the polymer (1), polymer (2) or polymer (3), the content of polymerization units based on other monomers copolymerizable with the polymerization units (1), (2) or (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 polymerization units. It is particularly preferable that the content of polymerization units based on other monomers copolymerizable with the polymerization units (1), (2) or (3) is substantially 0 mol%, and it is most preferable that the polymer (1), (2) or (3) does not contain polymerization units based on other monomers.

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

[0215] The weight average molecular weight of the polymer (I) is 0.2×10 4 Above, 0.4×10 4 Above, 0.6×10 4 Above, 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 25.0×10 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 Less than or equal to 40.0 x 10 4 It is preferable that:

[0216] The number average molecular weight and weight average molecular weight of the polymer (I) are values ​​calculated by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard. In addition, when measurement by GPC is not possible, the number average molecular weight of the polymer (I) can be obtained 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.

[0217] The number average molecular weight of the polymer (1), polymer (2) or polymer (3) is preferably 0.1×10 or less, since this allows the polymer (1), polymer (2) or polymer (3) to be recovered at a higher recovery rate. 4 Super, 0.2×10 4 Above, 0.3×10 4 Above, 0.4×10 4 Above, 0.5 x 10 4 That's it, 1.0 x 10 4 That's it, 3.0 x 10 4 or more, or 3.1×10 4 The number average molecular weight of the polymer (1), the polymer (2) or the 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 Less than or equal to 20.0 x 10 4 It is preferable that:

[0218] The weight average molecular weight of the polymer (1), the polymer (2) or the polymer (3) is 0.2×10 4 Above, 0.4×10 4 Above, 0.6×10 4 Above, 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 25.0×10 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 Less than or equal to 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, etc. 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 the 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 side chains preferably carry ionic groups.

[0224] The polymer (I) preferably comprises an ionic group having a pKa of less than 10, more preferably less than 7. The ionic group of the polymer (I) is 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 to 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 the sulfonate group.

[0226] In addition, the water-soluble fluorine-containing polymer is 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’each independently represents at least one selected from the group consisting of a (hydro)(fluoro)carbon group having 1 to 24 carbon atoms, which has one or more ionic groups (X), and a (hydro)(fluoro)carbon group having 1 to 24 carbon atoms, which may contain one or more of H, O and Cl (excluding groups having an ionic group (X)); R f 1 may be the same or different in each occurrence and are perfluoroalkylene groups having 1 to 7 carbon atoms; R 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 equal to or greater than 1; The ionic group (X) is -SO 3 X a , -PO 3 X a and -COOX a (X a is H, an ammonium group, or a monovalent metal; A polyfunctional fluoropolyether dispersant represented by the formula (I) can be used.

[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 Examples of -O- include -CF 2 CF 2 O-, -CFYO-, -CF 2 CFYO-, -CF 2 O-, -CF 2 (CF 2 ) z CF2 O- (wherein Y is a fluoro(oxy)alkyl group having 1 to 5 carbon atoms; z is 1 or 2), and the like.

[0229] In the general formula representing the polyfunctional fluoropolyether dispersant, the repeating unit -R f 2 Examples of -O- include -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 having one or more ionic groups (X), 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 (e.g., -CF 2 Cl, -CF 3 etc.), etc.

[0231] Such polyfunctional fluoropolyether dispersants include, for example, dispersants (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 includes fluoropolyether acids 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 having 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, the salts of the fluoropolyether acids are preferred, the ammonium salts of the fluoropolyether acids are more preferred, and the ammonium salts of the fluoropolyether carboxylic acids are even more preferred.

[0237] Such fluoropolyether acids or salts thereof include those of 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 (In the formula, m and n are the same as above.) or a salt thereof.

[0238] Examples of the fluoropolyether acid or a salt thereof include the fluoropolyether acids or salts thereof 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 are possible without departing from the spirit and scope of the claims.

[0240] <1> According to a first aspect of the present disclosure, Number average molecular weight is 0.1×10 4 The present invention provides a method for recovering a water-soluble fluoropolymer, which comprises mixing a composition containing a water-soluble fluoropolymer having a molecular weight of more than 1000 and water with a cationic polymer, and recovering the water-soluble fluoropolymer from the composition. <2> According to a second aspect of the present disclosure, There is provided a recovery method according to a first aspect, which comprises mixing the composition with the cationic polymer to produce an agglomerate containing the water-soluble fluoropolymer and the cationic polymer, and separating water from the agglomerate to recover the water-soluble fluoropolymer as the agglomerate. <3> According to a third aspect of the present disclosure, There is provided a recovery method according to the first or second aspect, wherein 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 recovery method 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, The number average molecular weight of the water-soluble fluorine-containing polymer is 0.3×10 4 A recovery method according to any one of the above first to fourth aspects is provided. <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, wherein 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, 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 =CX 2 R(-CZ 1 Z 2 -A 0 ) m (I) (In the formula, X 1 and X 3 are each independently F, Cl, H or CF 3 ;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, The number average molecular weight of the polymer (I) is 0.3×10 4 As described above, there is provided a recovery method according to the seventh aspect. <9> According to a ninth aspect of the present disclosure, According to the seventh or eighth aspect, there is provided a recovery method, in which the ion exchange rate of the polymer (I) is 53 or less. <10> According to a tenth aspect of the present disclosure, There is provided the recovery method according to any one of the first to ninth aspects, 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> According to an eleventh aspect of the present disclosure, There is provided a recovery method according to any one of the first to tenth aspects, wherein 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 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), and 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), The number average molecular weight of the water-soluble fluorine-containing polymer is 0.3×10 4 ~20.0×10 4 and the content of the water-soluble fluorine-containing polymer in the composition is 0.020 to 0.2% by mass, the cationic polymer is polyethyleneimine, The amount of the cationic polymer is 30 to 500% by mass based on the mass of the water-soluble fluoropolymer. According to any one of the first to eleventh aspects, there is provided a recovery method. CX 2 =CY(-CZ 2 -O-Rf-A) (1) (In the formula, 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; Z may be 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 having 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; R 7 is H or an organic group. CX 2 =CY(-O-Rf-A) (2) (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; 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, metal atom, -NR 7 4 , optionally substituted imidazolium, optionally substituted pyridinium or optionally substituted phosphonium; R 7 is H or an organic group. <13> According to a thirteenth aspect of the present disclosure, mixing the 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 polymer 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 polymer selected from the group consisting of an anionic polymer, a nonionic polymer, and an amphoteric polymer; Separating the water from the coagulate According to any one of the first to twelfth aspects, there is provided a recovery method. EXAMPLES

[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 fluoropolymer> The molecular weights of Polymers 1 to 4 were measured by GPC.

[0244] <Concentration of water-soluble fluoropolymer> The concentrations of the polymers 1 to 4 were measured by liquid chromatography (LC) using a charged aerosol detector manufactured by Thermo Fisher Scientific as a detector.

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

[0246] Example 1 CF with number average molecular weight of 18,000 2 =CFOCF 2 5 g of a 10 mass% aqueous solution of polyethyleneimine was added to 1 L of an aqueous solution containing 1000 mass ppm of a homopolymer of COOH (polymer 1) while stirring. Immediately after the addition, a cloudy 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 mass ppm. 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 number average molecular weight of 15,000 2 =CFOCF 2 CF 2 SO 3 4 g of a 10 mass% aqueous solution of polyethyleneimine was added to 1 L of an aqueous solution containing 1000 mass ppm of a homopolymer of H (polymer 2) while 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 mass ppm.

[0248] Example 3 2 g of a 10 mass% aqueous solution of polyethyleneimine was added to 1 L of an aqueous solution containing 430 mass ppm of polymer 1 having a number average molecular weight of 18000 while stirring. Immediately after the addition, a cloudy 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 mass ppm.

[0249] Example 4 1 g of 10 mass% aluminum sulfate aqueous 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 adjusted to a solid content concentration of 10 mass% Epomin P-1000 manufactured by Nippon Shokubai Co., Ltd. was added and stirred for 1 minute. White flocs were generated, and the stirring was stopped and the mixture was left 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 10% by mass aluminum sulfate aqueous solution was added to 1 L of an aqueous solution containing 860 ppm by mass of polymer 2 having a number average molecular weight of 15,000, and the solution was stirred. 3 g of a solution adjusted to a solid content concentration of 10% Epomin P-3000 manufactured by Nippon Shokubai Co., Ltd. was then added and stirred for 1 minute. White flocs were generated, and the stirring was stopped and the solution was left 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 ppm by mass.

[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 solution was stirred. 2.5 g of a solution in which the solid content concentration of Epomin P-3000 manufactured by Nippon Shokubai Co., Ltd. was adjusted to 10% was then added and stirred for 1 minute. The solution became cloudy, and did not settle even after stopping the stirring and leaving it for 1 hour. When 2 g of an aqueous solution in which an anionic polymer flocculant (manufactured by MT Aquapolymer Co., Ltd., Acofloc A-110) was adjusted to a concentration of 0.1% by mass was added to this solution and stirred, white flocs were generated, and the solution was left to stand for 1 hour after stopping the stirring 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 1.9 ppm by mass.

[0252] Example 7 3 g of 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 solution was stirred. 1 g of a solution in which the solid content concentration of Epomin P-3000 manufactured by Nippon Shokubai Co., Ltd. was adjusted to 10% was then added and stirred for 1 minute. The solution became cloudy, and did not settle 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 this solution and stirred, white flocs were generated, and the stirring was stopped and left 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 ppm by mass.

[0253] Example 8 CF with number average molecular weight of 5300 2 =CFOCF 2 CF 2 SO 3 4 g of a 10 mass% aqueous solution of polyethyleneimine was added to 1 L of an aqueous solution containing 1000 mass ppm of a homopolymer of H (polymer 3) while 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 mass ppm.

[0254] Example 9 995 kg of an aqueous solution containing 630 ppm by mass of polymer 3 was placed in a 1000 L agitator-equipped coagulation tank and stirred. 754 g of 27% aluminum sulfate aqueous 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 further 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 mono pump NEL16PUN manufactured by Heishin Soubi Co., Ltd., and solid-liquid separation was performed 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 Number average molecular weight of 122,000 CH2 =CFCF 2 OCF(CF 3 To 1 L of an aqueous solution containing 400 ppm of a homopolymer of 1,2-dichlorophenyl ether (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 solution was left to stand for 1 hour to allow the flocs to settle. The supernatant was collected and the concentration of polymer 4 was measured by LC, and 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 (MT Aquapolymer Co., Ltd., Acofloc A-110) 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 was colorless and transparent and no precipitate was observed. After the addition of 20 g, stirring was stopped and the solution was left to stand for 1 hour, but no precipitate was observed.

[0257] Comparative Example 2 A total of 20 g of an aqueous solution containing a nonionic polymer flocculant (Organo Corporation, Orflock ON-1H) adjusted to a concentration of 1% by mass was added in five 4 g portions while 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 was colorless and transparent and no precipitate was observed. After the addition of 20 g, stirring was stopped and the solution was left to stand for 1 hour, but no precipitate was observed.

[0258] Comparative Example 3 10 g of a 10% by mass aqueous aluminum sulfate solution was added to 1 L of a solution containing 1000 ppm by mass of polymer 1 having a number average molecular weight of 15000, and the solution was neutralized with 1 mol / L aqueous sodium hydroxide solution while stirring until the pH reached 8. A white translucent precipitate was observed, and after leaving the solution 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 10% by mass aqueous solution of polyethyleneimine was added to 1 L of a solution containing 1000 ppm by mass of perfluorooctanoic acid while stirring for 1 minute. 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 perfluorooctanoic acid was 99 ppm by mass.

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, thereby recovering the water-soluble fluoropolymer from the composition, comprising the steps of: 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; the water-soluble fluorine-containing polymer is a polymer (I) containing polymerization units (I) based on a monomer (I) represented by general formula (I), the ion exchange rate of the polymer (I) is 53 or less, The content of the water-soluble fluorine-containing polymer is 0.030% by mass or more relative to the mass of the composition, The amount of the cationic polymer is 30% by mass or more based on the mass of the water-soluble fluoropolymer. Recovery method. General formula (I): CX 1 X 3 =CX 2 R(-CZ 1 Z 2 -A 0 ) m (I) (In the formula, X 1 and X 3 each independently represent F, Cl, H or CF 3 ; X 2 represents H, F, an alkyl group or a fluorine-containing alkyl group; A 0 represents an anionic group; R represents a linking group; Z 1 and Z 2 each independently represent H, F, an alkyl group or a fluorine-containing alkyl group; and m represents an integer of 1 or greater.)

2. A method for recovering a water-soluble fluorine-containing polymer, comprising mixing a composition containing a water-soluble fluorine-containing polymer having a number average molecular weight of more than 0.1 x 10 4 and water with a cationic polymer, and then mixing with at least one polymer selected from the group consisting of anionic polymers, nonionic polymers and amphoteric polymers, thereby recovering the water-soluble fluorine-containing polymer from the composition, 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; The water-soluble fluoropolymer is a polymer (I) containing polymerization units (I) based on a monomer (I) represented by general formula (I), and the ion exchange rate of the polymer (I) is 53 or less. Recovery method. General formula (I): CX 1 X 3 =CX 2 R(-CZ 1 Z 2 -A 0 ) m (I) (In the formula, X 1 and X 3 each independently represent F, Cl, H or CF 3 ; X 2 represents H, F, an alkyl group or a fluorine-containing alkyl group; A 0 represents an anionic group; R represents a linking group; Z 1 and Z 2 each independently represent H, F, an alkyl group or a fluorine-containing alkyl group; and m represents an integer of 1 or more.)

3. The method for recovering the water-soluble fluoropolymer according to claim 1, further comprising the steps of: mixing the composition with the cationic polymer to produce an agglomerate containing the water-soluble fluoropolymer and the cationic polymer; and separating water from the agglomerate to recover the water-soluble fluoropolymer as the agglomerate.

4. 2. The method according to claim 1, wherein the amount of said cationic polymer is 30 to 10,000% by mass based on the mass of said water-soluble fluoropolymer.

5. The method for recovering a water-soluble fluorine-containing polymer according to claim 2, wherein the amount of the cationic polymer is 1 to 10,000 mass % relative to the mass of the water-soluble fluorine-containing polymer.

6. The number average molecular weight of the water-soluble fluorine-containing polymer is 0.3×10 ４ The method for recovering the above-mentioned composition according to claim 1 or 2.

7. The number average molecular weight of the polymer (I) is 0.3×10 ４ The method for recovering the above-mentioned composition according to claim 1 or 2.

8. 2. The method according to claim 1, wherein the content of said water-soluble fluorine-containing polymer in said composition is from 0.030% by mass to 1% by mass relative to the mass of said composition.

9. The recovery method described in claim 2, wherein the content of the water-soluble fluorine-containing polymer in the composition is greater than 0 mass% and less than 1 mass%, relative to the mass of the composition.

10. 3. The method according to claim 1, wherein the recovery rate of the water-soluble fluoropolymer is 99.0 mass % or more.

11. the water-soluble fluorine-containing polymer 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 all polymerization units of the polymer (1), and the content of polymerization units (2) in the polymer (2) is 90 mol % or more based on all polymerization units of the polymer (2), The number average molecular weight of the water-soluble fluorine-containing polymer is 0.3×10 ４ ~20.0 x 10 ４ and the content of the water-soluble fluorine-containing polymer in the composition is 0.030 to 0.2% by mass, the cationic polymer is polyethyleneimine, The amount of the cationic polymer is 30 to 500% by mass based on the mass of the water-soluble fluoropolymer. The recovery method according to claim 1. CX ２ =CY(-CZ ２ -O-Rf-A) (1) (In the formula, 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; Z may be 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. CX ２ =CY(-O-Rf-A) (2) (In the formula, 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 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.

12. mixing the 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 polymer 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 polymer selected from the group consisting of an anionic polymer, a nonionic polymer, and an amphoteric polymer; Separating the water from the coagulate The recovery method according to claim 2.

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