Method for recovering water-soluble fluorine-containing polymer

Abstract

The present invention provides a method for recovering a water-soluble fluorine-containing polymer by mixing a composition containing a water-soluble fluorine-containing polymer having a number average molecular weight of more than 0.1 * 104 and water with a cationic polymer, thereby recovering the water-soluble fluorine-containing polymer from the composition.

Description

Technical Field

[0001] This disclosure relates to a method for recovering water-soluble fluoropolymers. Background Technology

[0002] Patent document 1 describes a method for reducing the amount of fluoride compounds in an aqueous phase, comprising: a) The step of adding one or more polycationic polymers or their precursor polymers to the aqueous phase to at least partially precipitate fluorine compounds; and b) The step of adding one or more polyanionic polymers to the aqueous phase.

[0003] Patent document 2 discloses a water treatment method, characterized by a removal step of removing polymer (I) from water containing polymer (I), wherein the polymer (I) comprises a polymerization unit (I) based on a monomer represented by the following general formula (I).

[0004] CX 1 X 3 =CX 2 R(-CZ 1 Z 2 -A 0 ) m (I)

[0005] (where X) 1 and X 3 Each is independently F, Cl, H or CF3; X 2 It is H, F, alkyl, or fluorinated alkyl; A 0 R is an anionic group; R is a linking group; Z is an anionic group. 1 and Z 2 Each is independently H, F, alkyl, or fluoroalkyl; m is an integer greater than or equal to 1.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2011-519976

[0009] Patent Document 2: International Publication No. 2020 / 218621 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The purpose of this disclosure is to provide a recovery method for water-soluble fluoropolymers with a high recovery rate.

[0012] Methods for solving problems

[0013] According to this disclosure, a method for recovering water-soluble fluoropolymers is provided, which involves processing polymers containing a number average molecular weight exceeding 0.1 × 10⁻⁶. 4 A composition of a water-soluble fluoropolymer and water is mixed with a cationic polymer, and the water-soluble fluoropolymer is recovered from the composition.

[0014] The effects of the invention

[0015] According to this disclosure, a recovery method capable of recovering water-soluble fluoropolymers with a high recovery rate can be provided. Detailed Implementation

[0016] In this disclosure, "organic group" refers to a group formed by removing one hydrogen atom from a group containing one or more carbon atoms or an organic compound. Preferably, the organic group is an alkyl group having one or more substituents.

[0017] In this disclosure, the range represented by the endpoints includes all values ​​contained in that range (e.g., 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98, etc.).

[0018] In this disclosure, the term "at least 1" includes all values ​​greater than 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.).

[0019] The following describes in detail the specific embodiments of this disclosure, but this disclosure is not limited to the following embodiments.

[0020] As a group containing a number average molecular weight exceeding 0.1 × 10⁻⁶ 4 A method for recovering water-soluble fluoropolymers from a composition of water and water has been proposed. When using a cationic polymer, it was found that the water-soluble fluoropolymer could be recovered at a very high rate. Patent Document 2 discloses a water treatment method, but the treatment method using a cationic polymer has not been specifically studied.

[0021] That is, in the recovery method disclosed herein, by using molecules containing a number average molecular weight exceeding 0.1 × 10⁻⁶... 4 A composition of a water-soluble fluoropolymer and water is mixed with a cationic polymer, and the water-soluble fluoropolymer is recovered from the composition. By using this method, a coagulant containing both the water-soluble fluoropolymer and the cationic polymer can be generated. Therefore, by separating the water and the coagulant, the water-soluble fluoropolymer can be recovered in the form of the coagulant, and furthermore, high-purity water can also be recovered.

[0022] (Catonic polymer)

[0023] In the recycling method disclosed herein, a cationic polymer is used. Examples of cationic polymers include polyaminoalkyl methacrylates such as dimethylaminoethyl methacrylate, polyethyleneimine, halogenated polydiallyl ammonium, chitosan, and urea-formaldehyde resin.

[0024] Commercially available cationic polymers include Takifloc C-403, C-408, C-805, C-806, and C-809 manufactured by Taki Chemical 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 Kogyo Co., Ltd.; and UNISENCE FPA100L, KHE104L, KHF11L, and KHP10P manufactured by Senka Co., Ltd.

[0025] As a cationic polymer, the preferred choice is at least one of the following groups, namely polyethyleneimine, poly(diallyl dimethylammonium) and its salts, poly(trimethylaminoethyl methacrylate) and its salts, poly(dimethylaminoethyl methacrylate), dimethylaminoethyl methacrylate, dimethylamine-epimyl chlorohydrin condensate, dicyandiamide-formaldehyde condensate, and dicyandiamide-diethylenetriamine condensate, with polyethyleneimine being more preferred, in order to enable the recovery of water-soluble fluoropolymers at a higher recovery rate.

[0026] (Mixed process)

[0027] In the recycling method disclosed herein, a composition containing a water-soluble fluoropolymer and water is mixed with a cationic polymer. The composition and the water-soluble fluoropolymer are described below.

[0028] The content of the water-soluble fluoropolymer in the composition is preferably more than 0% by mass and less than 1.0% by mass relative to the mass of the composition. More preferably, the content of the water-soluble fluoropolymer in the composition is more than 0.003% by mass, more than 0.005% by mass, more than 0.010% by mass, more than 0.020% by mass, or more than 0.030% by mass relative to the mass of the composition. The content of the water-soluble fluoropolymer in the composition is less than 0.5% by mass or less than 0.2% by mass relative to the mass of the composition.

[0029] The content of water-soluble fluoropolymers in the composition can be determined by liquid chromatography or NMR. When the water-soluble fluoropolymer contains carbonyl groups, it can also be determined by Fourier transform infrared spectroscopy.

[0030] In addition, in International Publication Nos. 2014 / 099453, 2010 / 075497, 2010 / 075496, 2011 / 008381, 2009 / 055521, 1987 / 007619, Japanese Patent Application Publication No. 61-293476, 2010 / 075494, 2010 / 075359, 2012 / 082454, 2006 / 119224, and 2013 / 085864... Methods for determining the content of various polymers are described in publications such as Japanese Patent Application Publication No. 2012 / 082707, 2012 / 082703, 2012 / 082451, 2006 / 135825, 2004 / 067588, 2009 / 068528, Japanese Patent Application Publication No. 2004-075978, Japanese Patent Application Publication No. 2001-226436, Japanese Patent Application Publication No. 1992 / 017635, Japanese Patent Application Publication No. 2014 / 069165, and Japanese Patent Application Publication No. 11-181009. These methods for determining the content of water-soluble fluoropolymers can be used as methods for determining the content of various polymers.

[0031] The content of water-soluble fluoropolymers in the composition can be quantified using nuclear magnetic resonance (NMR), liquid chromatography (LC), Fourier transform infrared spectroscopy (FT-IR), etc. When the content of water-soluble fluoropolymers in the composition is at a low concentration of less than 0.1% by mass, quantification by LC is preferred.

[0032] As detectors for LC, ultraviolet absorbance detectors (UV), photodiode array detectors (PDA), differential refractive index detectors (RI), evaporative light scattering detectors (ELSD), charged particle detectors (CAD), and mass spectrometry detectors (MS) are preferred, ELSD, CAD, and MS are more preferred, CAD and MS are even more preferred, and MS is the most preferred.

[0033] For quantitative analysis, the preferred separation modes for the column include reversed-phase chromatography, normal-phase chromatography, ion-exchange chromatography, and size exclusion chromatography, with reversed-phase chromatography and size exclusion chromatography being more preferred.

[0034] The mobile phase is preferably water or a mixture of water and a water-soluble organic solvent. Buffers or ion-pairing reagents may be added to the water. Acetonitrile or methanol are preferred organic solvents.

[0035] When water-soluble fluoropolymers adsorb onto the metal materials in the LC flow path, reducing quantification and sensitivity, using ion-pairing reagents can improve quantification and sensitivity. Preferred ion-pairing reagents include triethylamine (TEA) and N,N-diisopropylethylamine (DIPEA). Hexafluoro-2-propanol is preferred as an acidic buffer for adjusting the pH of the mobile phase.

[0036] The amount of cationic polymer used in the recycling method disclosed herein is preferably 1% to 10,000% by mass relative to the mass of the water-soluble fluoropolymer, 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.

[0037] The composition can be mixed with a cationic polymer, for example, by adding the cationic polymer to the composition. The cationic polymer can be added once or more.

[0038] The pH of the composition mixed with the cationic polymer is preferably 4.0 or higher, more preferably 5.0 or higher, even more preferably 6.0 or higher, preferably 11.0 or lower, more preferably 9.0 or lower, and even more preferably 8.0 or lower.

[0039] The pH of the composition can be determined using a pH meter (e.g., Horiba pH meter D-20).

[0040] Before mixing the composition with the cationic polymer, the pH of the composition can be adjusted. pH adjustment can be achieved by mixing the composition with a pH adjuster. The pH adjuster is not limited; for example, acidic or basic compounds can be used. Examples of acidic compounds include hydrochloric acid (HCl), nitric acid (HNO3), sulfuric acid (H2SO4), and phosphoric acid (H3PO4), with hydrochloric acid (HCl) or nitric acid (HNO3) being preferred. Examples of basic compounds include alkali metal hydroxides such as NaOH and KOH; alkaline earth metal hydroxides such as Mg(OH)2 and Ca(OH)2; buffering salts such as disodium hydrogen phosphate; ammonia; amines; etc.

[0041] The temperature at which the composition is mixed with the cationic polymer is preferably 0°C or higher, more preferably 5°C or higher, even more preferably 10°C or higher, preferably 50°C or lower, more preferably 40°C or lower, and even more preferably 30°C or lower.

[0042] The composition can be mixed with the cationic polymer by stirring the mixture containing the composition and the cationic polymer. The stirring time is, for example, 30 seconds to 100 hours.

[0043] In the recycling method disclosed herein, an inorganic coagulant can be mixed with the composition. The mixing of the composition and the inorganic coagulant can be carried out simultaneously with the mixing of the composition and the cationic polymer, or before the mixing of the composition and the cationic polymer, or after the mixing of the composition and the cationic polymer.

[0044] The composition can be mixed with an inorganic coagulant, for example, by adding the inorganic coagulant to the composition. The inorganic coagulant can be added once or more than twice. Alternatively, the inorganic coagulant and the cationic polymer can be added alternately.

[0045] As inorganic coagulants, examples include metal salts, and commercially available products can be used. Products containing Mg can also be used. 2+ Ca 2+ Seawater, low molecular weight cationic polymeric coagulants, etc.

[0046] As an inorganic coagulant, a metal salt is preferred, more preferably a salt of a metal with a valence of 2 to 6, and even more preferably a salt of a metal with a valence of 3 to 6. As a metallic element constituting the metal salt, at least one element from the group consisting of Fe, Al, and Ca is preferred, more preferably at least one element from the group consisting of Fe and Al, and even more preferably Al. As a counter ion of the metallic element constituting the metal salt, at least one ion from the group consisting of sulfate ions, hydroxide ions, fluoride ions, nitrate ions, and chloride ions is preferred, more preferably at least one ion from the group consisting of sulfate ions and chloride ions, and even more preferably sulfate ions.

[0047] As an inorganic coagulant, it is preferred to select at least one of the group consisting of free iron salts and aluminum salts, more preferably at least one of the group consisting of free ferric chloride, aluminum sulfate and polyaluminum chloride, even more preferably at least one of the group consisting of free aluminum sulfate and polyaluminum chloride, and even more preferably aluminum sulfate.

[0048] The amount of inorganic coagulant used in the recycling method disclosed herein is preferably 0.1% to 1000% by mass relative to the mass of the water-soluble fluoropolymer, more preferably 1.0% by mass or more, even more preferably 10% by mass or more, even more preferably 30% by mass or more, more preferably 300% by mass or less, and even more preferably 100% by mass or less.

[0049] In the recycling method disclosed herein, in addition to cationic polymers, at least one selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers may be mixed with the composition. Besides cationic polymers, by using these polymers, it is possible to more readily generate condensates containing water-soluble fluoropolymers, enabling the recovery of water-soluble fluoropolymers at a higher recovery rate.

[0050] The mixing of the composition with at least one selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers can be carried out simultaneously with the mixing of the composition with the cationic polymer, before the mixing of the composition with the cationic polymer, or after the mixing of the composition with the cationic polymer. Preferably, at least one selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers is mixed with the composition after the composition is mixed with the cationic polymer.

[0051] The weight-average molecular weight of the anionic polymer, nonionic polymer, and amphoteric polymer is preferably 100,000 or more, more preferably 500,000 or more, and even more preferably 1,000,000 or more.

[0052] 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 addition of at least one of these polymers can be done once or more than twice. Alternatively, at least one selected from the group consisting of nonionic polymers and amphoteric polymers can be added alternately with a cationic polymer.

[0053] Examples of anionic polymers include sodium polyacrylate, partially hydrolyzed polyacrylamide, partially sulfonated polyacrylamide, and poly(2-acrylamide)-2-methylpropane sulfate, which are all polyacrylamide-based polymeric coagulants.

[0054] 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 Tagi Chemicals; SUMIFLOC FA-40 and FA-50 manufactured by MTAquaPolymer; DIAFLOC AP199, Ap120C, Ap784, and DF732B manufactured by Mitsubishi Chemicals; and Water Flock LA-912M, A-52M, and A-71 manufactured by Technica Goudou Co., Ltd.

[0055] The amount of anionic polymer used in the recycling method disclosed herein is preferably 0.001% to 50% by mass relative to the mass of the water-soluble fluoropolymer, more preferably 0.004% by mass or more, even more preferably 0.010% by mass or more, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0056] Examples of nonionic polymers include polyacrylamide and polyethylene oxide-based polymeric coagulants.

[0057] Commercially available nonionic polymers include ACCOFLOCN-100, N-102, and N-104 manufactured by MT AquaPolymer, ORFLOCK ON-1H, ON-2, ON-3, and N-1 manufactured by ORGANO Co., Ltd., and Water Flock L N-52B manufactured by TechnicaGoudou Co., Ltd.

[0058] The amount of nonionic polymer used in the recycling method disclosed herein is preferably 0.001% to 50% by mass relative to the mass of the water-soluble fluoropolymer, more preferably 0.004% by mass or more, even more preferably 0.010% by mass or more, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0059] As an amphoteric polymer, commercially available polymers that serve as amphoteric polymeric coagulants can be used. Examples of amphoteric polymers include copolymers of acrylamide, aminoalkyl methacrylate, and sodium acrylate.

[0060] Commercially available amphoteric polymers include Takifloc MC-601, MC-602, and MC-603 manufactured by Taki Chemical Co., Ltd., and DIAFLOC KA003 and KA606A manufactured by Mitsubishi Chemical Co., Ltd.

[0061] The amount of amphoteric polymer used in the recycling method disclosed herein is preferably 0.001% to 50% by mass relative to the mass of the water-soluble fluoropolymer, more preferably 0.004% by mass or more, even more preferably 0.010% by mass or more, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0062] In one embodiment of the recycling method disclosed herein, A composition containing a water-soluble fluoropolymer and water is mixed with an inorganic coagulant. A composition containing a water-soluble fluoropolymer, water, and an inorganic coagulant is mixed with a cationic polymer. A composition containing a water-soluble fluoropolymer, water, an inorganic coagulant, and a cationic polymer is mixed with at least one polymer selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers. The formation of a coagulant comprising a water-soluble fluoropolymer, an inorganic coagulant, a cationic polymer, and at least one selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers. Separate water from condensate. Therefore, water-soluble fluoropolymers can be recovered in the form of condensates.

[0063] In the above embodiments, the coagulants generated in each process can be appropriately separated from and recycled from the water. In the above embodiments, the pH of the composition can be appropriately adjusted in each process. In addition, each process can be intermittent or continuous.

[0064] In the recovery method disclosed herein, the composition is mixed with a cationic polymer to generate a coagulant containing a water-soluble fluoropolymer and a cationic polymer, and water is separated from the coagulant, thereby enabling the recovery of the water-soluble fluoropolymer in the form of the coagulant.

[0065] The separation of water and coagulation can be carried out by known methods such as filtering a mixture containing water and coagulation, applying centrifugal force to a mixture containing water and coagulation, or allowing the mixture to stand to allow the coagulation to precipitate.

[0066] By using the recovery method disclosed herein, it is possible to recover more than 95.0% by mass of the water-soluble fluoropolymer contained in the composition. The recovery rate of the water-soluble fluoropolymer is preferably more than 99.0% by mass, and more preferably more than 99.5% by mass.

[0067] Furthermore, high-purity water can also be recovered using the recovery method disclosed herein. The recovered water contains less than 30 ppm by mass relative to the water content, more preferably less than 10 ppm by mass, and even more preferably less than 1 ppm by mass. The content of water-soluble fluoropolymers in the water is determined by the same method as the determination of the content of water-soluble fluoropolymers in the composition.

[0068] (A composition containing a water-soluble fluoropolymer and water)

[0069] The composition provided for the recovery method of this disclosure contains a water-soluble fluoropolymer and water. The composition provided for the recovery method of this disclosure is generally an aqueous solution of a water-soluble fluoropolymer dissolved in water, but may also be a dispersion in which a portion of the components are dispersed in water.

[0070] The composition provided for the recycling method of this disclosure may contain water-soluble fluoropolymers and other components besides water. Examples of other components include water-insoluble fluoropolymers; fluorine-free polymers; compounds with a molecular weight of less than 1000; etc.

[0071] Examples of compounds with a molecular weight of less than 1000 include fluorinated surfactants, fluorinated monomers and other fluorinated compounds, hydrocarbon surfactants, organic solvents, monomers, polymerization initiators, chain transfer agents, and precipitants.

[0072] The content of other components relative to the composition is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.2% by mass or less. The lower limit is not particularly limited and can be 0% by mass.

[0073] The composition provided for the recycling method of this disclosure may contain polymers other than water-soluble fluoropolymers. These other polymers may be water-soluble or water-insoluble, and generally lack ionic groups entirely, or have a limited number of ionic groups that result in an ion exchange rate higher than about 100. The ion exchange rate of these other polymers is preferably greater than 53, more preferably greater than 100, further preferably greater than 1000, particularly preferably greater than 2000, and especially preferably greater than 5000.

[0074] Other examples of polymers include fluoropolymers and fluororubbers.

[0075] Examples of fluoropolymers include polytetrafluoroethylene (PTFE); copolymers of tetrafluoroethylene (TFE) and other monomers that can copolymerize with TFE (such as fluorinated monomers like vinylidene fluoride, hexafluoropropylene, trifluorochloroethylene, perfluoro(alkyl vinyl ethers), hydrocarbon olefins like ethylene, propylene, isobutylene, and alkyl vinyl ethers, etc.) (e.g., tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoro(alkyl vinyl ether) copolymer (PFA), and ethylene-tetrafluoroethylene copolymer (ETFE); polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and ethylene-chlorotrifluoroethylene (ECTFE).

[0076] Examples of fluororubbers include vinylidene fluoride-hexafluoropropylene copolymers and other vinylidene fluoride-based rubbers, tetrafluoroethylene-propylene rubbers, and tetrafluoroethylene-perfluoromethyl vinyl ether rubbers and other perfluoroelastomers.

[0077] The compositions provided for the recycling methods of this disclosure can be, for example, wastewater generated in industrial production. That is, the compositions provided for the recycling methods of this disclosure can be wastewater. The compositions provided for the recycling methods of this disclosure can be compositions generated in polymer manufacturing processes. The compositions provided for the recycling methods of this disclosure can be compositions derived from raw materials used in polymerization processes. The polymerization process can be a process in which monomers are polymerized in the presence of a water-soluble fluoropolymer and water.

[0078] The compositions produced in the polymer manufacturing process may include, in addition to compositions produced in the polymerization process of polymerizing one or more monomers, compositions produced in pretreatment processes before the polymerization process (e.g., processes for preparing emulsifiers of a specified concentration), and compositions produced in posttreatment processes after the polymerization process (e.g., concentration processes of aqueous dispersions, solid-liquid separation processes, precipitation processes, washing processes, dehydration processes, drying processes, heat treatment processes, etc.). Compositions produced in the polymerization process may also include aqueous solutions, dispersions, and liquids obtained by liquefying gases. Furthermore, compositions produced in the polymerization process may include, in addition to compositions directly produced in the polymerization process, compositions obtained by treating compositions directly produced in the polymerization process through methods such as filtration, distillation, concentration, and dilution.

[0079] Examples of monomers include tetrafluoroethylene (TFE), hexafluoropropylene (HFP), trifluorochloroethylene (CTFE), fluoroethylene, vinylidene fluoride (VDF), trifluoroethylene, fluoroalkyl vinyl ethers, fluoroalkyl vinyl ethers, fluoroalkyl allyl ethers, trifluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutylene, hexafluoroisobutylene, and general formula (100): CHX 101 =CX 102 Rf 101 (where X) 101 and X 102 One of them is H, the other is F, and Rf 101 Fluorinated monomers, fluorinated vinyl heterocyclic compounds, monomers that provide crosslinking sites, etc., are shown as straight-chain or branched fluorinated alkyl groups with 1 to 12 carbon atoms.

[0080] Examples of the aforementioned fluoroalkyl vinyl ethers include, for example...

[0081] General formula (110): CF2 = CF - ORf 111

[0082] (where Rf) 111 Fluorinated monomers (representing perfluorinated organic groups) General formula (120): CF2 = CF - OCH2 - Rf 121 (where Rf) 121 Fluorinated monomers (represented by perfluoroalkyl groups having 1 to 5 carbon atoms) General formula (130): CF2=CFOCF2ORf 131 (where Rf) 131It refers to fluorinated monomers represented by straight-chain or branched perfluoroalkyl groups having 1 to 6 carbon atoms, cyclic perfluoroalkyl groups having 5 to 6 carbon atoms, and straight-chain or branched perfluorooxyalkyl groups having 2 to 6 carbon atoms containing 1 to 3 oxygen atoms. General formula (140): CF2=CFO(CF2CF(Y) 141 )O) m (CF2) n F (where Y) 141 Represents a fluorine atom or a trifluoromethyl group. m is an integer from 1 to 4. n is an integer from 1 to 4. The fluorine-containing monomers shown are... General formula (150): CF2 = CF - O - (CF2CFY) 151 -O) n -(CFY 152 ) m -A 151 (where Y) 151 This indicates a fluorine atom, a chlorine atom, a -SO2F group, or a perfluoroalkyl group. Perfluoroalkyl groups may contain ether-like oxygen atoms and -SO2F groups. n represents an integer from 0 to 3. n Y atoms 151 They can be the same or different. Y 152 Represents a fluorine atom, a chlorine atom, or a -SO2F group. m represents an integer from 1 to 5. m Y atoms 152 They can be the same or different. A 151 Indicates -SO2X 151 -COZ 151 or -POZ 152 Z 153 X 151 Represents F, Cl, Br, I, -OR 151 or -NR 152 R 153 Z 151 Z 152 and Z 153 Same or different, indicating -NR 154 R 155 or -OR 156 R 151 R 152 R 153 R 154 R 155 and R 156 The same or different refers to fluorine-containing monomers such as H, ammonium, alkali metals, alkyl groups with or without fluorine atoms, aryl groups, or sulfonyl groups.

[0083] (Water-soluble fluoropolymer)

[0084] In the recovery method disclosed herein, the sample contains a number average molecular weight exceeding 0.1 × 10⁻⁶. 4 The present disclosure describes the recovery of water-soluble fluoropolymers from a composition of water and water. The recovery method aims to recover water-soluble fluoropolymers with higher molecular weights. It is currently known that even when using the recovery method of the present disclosure, water-soluble fluoropolymers with excessively low number-average molecular weights cannot be recovered at high rates. The use of cationic polymers for the purpose of recovering water-soluble fluoropolymers with higher molecular weights is one of the characteristics of the recovery method of the present disclosure.

[0085] Water solubility refers to the property of easily dissolving or dispersing in aqueous media. Fluoropolymers that are water-soluble, for example, cannot have their particle size determined by dynamic light scattering (DLS) or show particle sizes below 10 nm.

[0086] As a water-soluble fluoropolymer, a water-soluble fluoropolymer can be used in which the proportion of hydrogen atoms bonded to carbon atoms replaced by fluorine atoms is 50% or more. The "proportion of hydrogen atoms bonded to carbon atoms replaced by 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.

[0087] Water-soluble fluoropolymers have a number-average molecular weight exceeding 0.1 × 10⁻⁶. 4 Regarding the number-average molecular weight of water-soluble fluoropolymers, 0.2 × 10⁻⁶ is preferred, as it allows for higher recovery rates. 4 Above, 0.3×10 4 Above, 0.4×10 4 Above, 0.5×10 4 Above, 1.0×10 4 Above, 3.0×10 4 Above, or 3.1 × 10 4 That's all. Additionally, the preferred number-average molecular weight of the water-soluble fluoropolymer is 75.0 × 10⁻⁶. 4 Below, 50.0×10 4 Below, 40.0×10 4 Below, 30.0×10 4 Below, or 20.0×10 4 the following.

[0088] The preferred weight-average molecular weight of the water-soluble fluoropolymer is 0.2 × 10⁻⁶. 4 Above, 0.4×10 4 Above, 0.6×10 4 Above, 0.8×10 4 Above, 1.0×10 4 Above, 2.0×104 Above, 5.0×10 4 Above, 10.0×10 4 Above, 15.0×10 4 Above, 20.0×10 4 Above, or 25.0 × 10 4 That's all. Additionally, the weight-average molecular weight of the water-soluble fluoropolymer is preferably 150.0 × 10⁻⁶. 4 Below, 100.0×10 4 Below, 60.0×10 4 Below, 50.0×10 4 Below, or 40.0×10 4 the following.

[0089] The number-average molecular weight and weight-average molecular weight of water-soluble fluoropolymers are calculated using gel permeation chromatography (GPC) with monodisperse polystyrene as a standard. Alternatively, when GPC is not feasible, the number-average molecular weight of water-soluble fluoropolymers can be determined based on 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 determined according to JIS K 7210.

[0090] Water-soluble fluoropolymers preferably have ionic groups. As ionic groups in water-soluble fluoropolymers, anionic groups are preferred, and examples of anionic groups (A) described later are also preferred. 0 (The same group.)

[0091] Water-soluble fluoropolymers preferably have an ion exchange rate (IXR) of 53 or less. IXR is defined as the number of carbon atoms in the polymer backbone relative to an ionic group. Precursor groups that become ionic through hydrolysis (e.g., -SO2F) are not considered ionic groups for the purpose of determining IXR.

[0092] The IXR of water-soluble fluoropolymers is preferably 0.5 or more, 1 or more, 3 or more, 4 or more, 5 or more, or 8 or more. Furthermore, the IXR of water-soluble fluoropolymers is preferably 43 or less, 33 or less, or 23 or less.

[0093] The preferred ion exchange capacity of water-soluble fluoropolymers is 0.80 meq / g or higher, 1.50 meq / g or higher, 1.75 meq / g or higher, 2.00 meq / g or higher, 2.20 meq / g or higher, exceeding 2.20 meq / g, 2.50 meq / g or higher, 2.60 meq / g or higher, 3.00 meq / g or higher, or 3.50 meq / g or higher. The ion exchange capacity is the content of ionic groups (anionic groups) in the water-soluble fluoropolymer, calculated from the composition of the water-soluble fluoropolymer.

[0094] In water-soluble fluoropolymers, ionic groups (anionic groups) are typically distributed along the polymer backbone. Water-soluble fluoropolymers comprise a polymer backbone and repeating side chains bonded to that backbone, the side chains preferably having ionic groups.

[0095] The water-soluble fluoropolymer preferably contains ionic groups having a pKa of less than 10, more preferably less than 7. The ionic groups of the water-soluble fluoropolymer are preferably selected from the group consisting of sulfonates, carboxylates, phosphonates, and phosphates.

[0096] The terms "sulfonate, carboxylate, phosphonate, and phosphate" refer to their respective salts or their respective acids capable of forming salts. When using salts, alkali metal salts or ammonium salts are preferred. The preferred ionic group is the sulfonate group.

[0097] As a water-soluble fluoropolymer, a polymer (I) comprising a polymer unit (I) based on a monomer (I) represented by general formula (I) is preferred.

[0098] General formula (I): CX 1 X 3 =CX 2 R(-CZ 1 Z 2 -A 0 ) m (I)

[0099] (where X) 1 and X 3 Each is independently F, Cl, H or CF3; X 2 It is H, F, alkyl, or fluorinated alkyl; A 0 R is an anionic group; R is a linking group; Z is an anionic group. 1 and Z 2 Each is independently H, F, alkyl, or fluoroalkyl; m is an integer greater than or equal to 1.

[0100] In this disclosure, the anionic groups include, in addition to anionic groups such as sulfate groups and carboxyl groups, functional groups that provide anionic groups such as acid groups like -COOH and acid-base groups like -COONH4. Preferably, the anionic groups are sulfate groups, carboxyl groups, phosphate groups, phosphonate groups, sulfonate groups, or -C(CF3)2OM (where M is -H, a metal atom, or -NR). 7 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 7 (H or organic groups).

[0101] R represents a linking group. In this disclosure, a "linking group" is a (m+1) valent linking group, where m is 1 and it is a divalent linking group. The linking group can be a single bond, preferably containing at least one carbon atom, and the number of carbon atoms can be 2 or more, 4 or more, 8 or more, 10 or more, or 20 or more. There is no upper limit; for example, it can be less than 100 or less than 50.

[0102] The linking group can be chain-like or branched, cyclic or acyclic, saturated or unsaturated, substituted or unsubstituted, and may contain one or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen, and may contain one or more functional groups selected from the group consisting of esters, amides, sulfonamides, carbonyl groups, carbonates, carbamates, ureas, and carbamates. The linking group does not contain a carbon atom and may be a chain-like heteroatom such as oxygen, sulfur, or nitrogen.

[0103] When m is an integer greater than or equal to 1, preferably 1 or 2, and more preferably 1, then Z 1 Z 2 and A 0 They can be the same or different.

[0104] Next, the preferred configuration when m is 1 in general formula (I) will be explained.

[0105] R is preferably a chain heteroatom such as oxygen, sulfur, or nitrogen, or a divalent organic group.

[0106] When R is a divalent organic group, the hydrogen atom bonded to the carbon atom can be replaced by a halogen other than fluorine, such as chlorine, and may or may not contain a double bond. Furthermore, R can be either chain-like or branched, or cyclic or acyclic. Additionally, R can contain functional groups (e.g., esters, ethers, ketones (keto groups), amines, halides, etc.).

[0107] In addition, R can be a non-fluorinated divalent organic group, or a partially fluorinated or perfluorinated divalent organic group.

[0108] R can be, for example: a hydrocarbon group on a carbon atom that is not bonded with a fluorine atom; a hydrocarbon group on which a portion of the hydrogen atoms bonded to a carbon atom are replaced by fluorine atoms; or a hydrocarbon group on which all the hydrogen atoms bonded to a carbon atom are replaced by fluorine atoms. These can contain oxygen atoms, double bonds, or functional groups.

[0109] R is preferably a hydrocarbon group with 1 to 100 carbon atoms that may contain ether bonds or ketone groups, wherein some or all of the hydrogen atoms bonded to the carbon atoms in the hydrocarbon group may be replaced by fluorine.

[0110] As R, it is preferably selected from -(CH2). a -、-(CF2) a -、-(CF2) a -O-, -O-(CF2) a -、-(CF2) a -O-(CF2) b -、-O(CF2) a -O-(CF2) b -、-(CF2) a -[O-(CF2) b ] c -、-O(CF2) a -[O-(CF2) b ] c -、-[(CF2) a -O] b -[(CF2) c -O] d -、-O[(CF2) a -O] b -、-O[(CF2) a -O] b -[(CF2) c -O] d -、-O-[CF2CF(CF3)O] a -(CF2) b -、-O-(CF2) a -O-[CF(CF3)CF2O] b -O-、-O-[CF2CF(CF3)O] a -(CF2) b -O-、-O-[CF2CF(CF3)O] a -(CF2) b -O-[CF(CF3)CF2O] c -O-、-[CF2CF(CF3)O] a -、-[CF(CF3)CF2O] a-、-(CF2) a -O-[CF(CF3)CF2O] a -、-(CF2) a -O-[CF(CF3)CF2O] a -(CF2) b -、-[CF2CF(CF3)] a -CO-(CF2) b - and at least one of their combinations.

[0111] In the formula, a, b, c, and d are independently at least 1 or more. a, b, c, and d can be 2 or more, 3 or more, 4 or more, 10 or more, or 20 or more. The upper limit of a, b, c, and d is, for example, 100.

[0112] R is more preferably selected from at least one of -O-CF2-, -O-CF2CF2-, -O-CF2CF2-O-, -O-CF2CF2CF2-, -O-CF2CF2CF2-O-, -O-CF2CF(CF3)-O-, -O-CF2CF2-O-CF(CF3)CF2-O-, -O-CF2CF(CF3)-O-CF2CF2-O-, and -O-CF2CF(CF3)-O-CF2-.

[0113] For R, the preferred general formula (r1) is: -CF2-O-(CX 6 2) e -{O-CF(CF3)} f -(O) g - (r1) (where X) 6 Each is independently H, F or CF3, e is an integer from 0 to 3, f is an integer from 0 to 3, and g is 0 or 1) as shown in the divalent group, more preferably the general formula (r2): -CF2-O-(CX 7 2) e -(O) g - (r2) (where X) 7 Each is an independent divalent group, represented by H, F, or CF3, e is an integer from 0 to 3, and g is 0 or 1.

[0114] Specific examples of preferred values ​​for R include: -CF2-O-, -CF2-O-CF2-, -CF2-O-CH2-, -CF2-O-CH2CF2-, -O-CF2-, -O-CF2CF2-, -O-CF2CF2CF2-, -O-CF2CF2CF2CF2-, -O-CF2CF(CF3)-O-CF2-, -O-CF2CF(CF3)-O-CF2CF2-, -CF2-O-CF2CF2-, -CF2-O-CF2CH2-, -CF2-O-CF2CF2CH2-, -CF2-O-CF(CF3)-, -CF2-O-CF(CF3)CF2-, -CF2-O-CF(CF3)CF2-, -CF2-O-CF(CF3)CF2-O-, -CF2-O-CF(CF3)CF2-O-CF2-, -CF2-O-CF(CF3)CH2-, etc. Wherein, R preferably contains a perfluoroalkylene group containing an oxygen atom, specifically, preferably -CF2-O-, -CF2-O-CF2-, -O-CF2-, -O-CF2CF2-, -O-CF2CF(CF3)-O-CF2-, -O-CF2CF(CF3)-O-CF2CF2-, -CF2-O-CF2CF2-, -CF2-O-CF(CF3)-, -CF2-O-CF(CF3)CF2- or -CF2-O-CF(CF3)CF2-O-.

[0115] -R-CZ as general formula (I) 1 Z 2 - Preferred general formula (s1): -CF2-O-(CX 6 2) e -{O-CF(CF3)} f -(O) g -CZ 1 Z 2 - (s1) (where X) 6 Each is independently H, F, or CF3, e is an integer from 0 to 3, f is an integer from 0 to 3, g is 0 or 1, and Z is an integer from 0 to 3. 1 and Z 2 Each group is independently represented by H, F, alkyl, or fluoroalkyl groups, in formula (s1), Z 1 and Z 2 More preferably, it is F or CF3, and even more preferably, one is F and the other is CF3.

[0116] Additionally, in general formula (I), -R-CZ 1 Z 2 - Preferred general formula (s2): -CF2-O-(CX 7 2)e -(O) g -CZ 1 Z 2 - (s2) (where X) 7 Each is independently H, F, or CF3, e is an integer from 0 to 3, g is 0 or 1, and Z is... 1 and Z 2 Each group is independently represented by H, F, alkyl, or fluoroalkyl groups, in formula (s2), Z 1 and Z 2 More preferably, it is F or CF3, and even more preferably, one is F and the other is CF3.

[0117] -R-CZ as general formula (I) 1 Z 2-, preferably -CF2-O-CF2-, -O-CF2CF2-, -O-CF2CF2CF2-, -O-CF2CF2CF2CF2-, -O-CF2CF(CF3)-O-CF2-, -O-CF2CF(CF3)-O-CF 2CF2-, -O-CF2CF(CF3)-O-CF2CF2CF2-, -CF2-O-CF(CF3)-, -CF2-OC(CF3)2-, -CF2-O-CF2-CF2-, -CF2-O-CF2-CF(CF3 )-, -CF2-O-CF2-C(CF3)2-, -CF2-O-CF2CF2-CF2-, -CF2-O-CF2CF2-CF(CF3)-, -CF2-O-CF2CF2-C(CF3)2-, -CF2-O-CF (CF3)-CF2-, -CF2-O-CF(CF3)-CF(CF3)-, -CF2-O-CF(CF3)-C(CF3)2-, -CF2-O-CF(CF3)CF2-CF2-, -CF2-O-CF(CF3)CF 2-CF(CF3)-, -CF2-O-CF(CF3)CF2-C(CF3)2-, -CF2-O-CF(CF3)CF2-O-CF2-, -CF2-O-CF(CF3)CF2-O-CF(CF3)- or -CF2- O-CF(CF3)CF2-OC(CF3)2-, more preferably -O-CF2CF2-, -O-CF2CF2CF2-, -O-CF2CF2CF2CF2-, -O-CF2CF(CF3)-O-CF2-, -O-CF2CF (CF3)-O-CF2CF2-, -CF2-O-CF(CF3)-, -CF2-O-CF2-CF(CF3)-, -CF2-O-CF2CF2-CF(CF3)-, -CF2-O-CF(CF3)-CF(CF3) -, -CF2-O-CF(CF3)CF2-CF(CF3)- or -CF2-O-CF(CF3)CF2-O-CF(CF3)-, more preferably -O-CF2CF2-, -O-CF2CF(CF3)-O-CF2CF2-.

[0118] Polymer (I) is also preferably highly fluorinated. For example, it is preferable to use anionic groups (A) other than phosphate moieties (e.g., CH2OP(O)(OM)2) and sulfate moieties (e.g., CH2OS(O)2OM). 0 In addition to ), more than 80%, more than 90%, more than 95%, or 100% of the CH bonds in polymer (I) are replaced by CF bonds.

[0119] Monomer (I) and polymer (I) except for anionic groups (A)0 In addition to having CF bonds, it is also preferred to have CH bonds. That is, in general formula (I), X 1 X 2 and X 3 All are F, and R is preferably a perfluoroalkyl group having 1 or more carbon atoms. The perfluoroalkyl group can be either chain-like or branched, cyclic or acyclic, and can contain at least one chain heteroatom. The number of carbon atoms in the perfluoroalkyl group can be 2 to 20, or 4 to 18.

[0120] The monomer (I) and polymer (I) can be partially fluorinated monomers and polymers. That is, the monomer (I) and polymer (I) are preferably free of anionic groups (A). 0 In addition to having a carbon atom, it also has at least one hydrogen atom bonded to a carbon atom and at least one fluorine atom bonded to a carbon atom.

[0121] Anionic group (A) 0 ) can be -SO2M, -SO3M, -OSO3M, -COOM, -SO2NR'CH2COOM, -CH2OP(O)(OM)2, [-CH2O]2P(O)(OM), -CH2CH2OP(O)(OM)2, [-CH2CH2O]2P(O)(OM), -CH2CH2OSO3M, -P(O)(OM)2, -SO2NR'CH2CH2OP(O)(OM)2, [-SO2NR'CH2CH2O]2P(O)(OM), -CH2OSO3M, -SO2NR'CH2CH2OSO3M, or -C(CF3)2OM. Preferably, -SO3M, -OSO3M, -COOM, -P(O)(OM)2 or -C(CF3)2OM are used; more preferably, -COOM, -SO3M, -OSO3M, -P(O)(OM)2 or -C(CF3)2OM are used; even more preferably, -SO3M, -COOM or -P(O)(OM)2 are used; and especially preferably, -SO3M or -COOM are used.

[0122] M represents H, a metal atom, and NR. 7 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 7 It is an H or an organic group.

[0123] Examples of metal atoms include alkali metals (Group 1) and alkaline earth metals (Group 2), with Na, K, or Li being preferred.

[0124] As M, -H, a metal atom, or NR is preferred. 7 4, more preferably -H, alkali metal (Group 1), alkaline earth metal (Group 2) or NR7 4. Further preferred are -H, -Na, -K, -Li or NH4, even more preferred are -H, -Na, -K or NH4, particularly preferred are -H, -Na or NH4, and most preferred are -H or -NH4.

[0125] In polymer (I), each polymer unit (I) may have different anionic groups or the same anionic groups.

[0126] The monomer (I) is also preferably the monomer shown in general formula (Ia).

[0127] Polymer (I) is also preferably a polymer comprising a polymeric unit (Ia) based on a monomer represented by the general formula (Ia).

[0128] CF2=CF-O-Rf 0 -A 0 (Ia)

[0129] (where A is in the formula) 0 It is an anionic group, Rf 0 Perfluorinated compounds can be chain-like or branched, cyclic or acyclic, saturated or unsaturated, substituted or unsubstituted, and can arbitrarily contain one or more heteroatoms selected from the group consisting of sulfur, oxygen, and nitrogen as a perfluorinated divalent linking group.

[0130] The monomer (I) is also preferably the monomer shown in general formula (Ib).

[0131] Polymer (I) is also preferably a polymer comprising a polymeric unit (Ib) based on a monomer represented by the general formula (Ib).

[0132] CH2=CH-O-Rf 0 -A 0 (Ib)

[0133] (where A is in the formula) 0 It is an anionic group, Rf 0 (This refers to the perfluorinated divalent linker defined by formula Ia.)

[0134] In general formula (I), A 0 Using sulfate groups is one of the preferred methods. A 0 For example, it can be -CH2OSO3M, -CH2CH2OSO3M, or -SO2NR'CH2CH2OSO3M, where R' is H or an alkyl group with 1 to 4 carbon atoms, and M is the same as above.

[0135] A 0In the case of a sulfate group, examples of monomers represented by general formula (I) include CF2=CF(OCF2CF2CH2OSO3M), CF2=CF(O(CF2)4CH2OSO3M), CF2=CF(OCF2CF(CF3)CH2OSO3M), CF2=CF(OCF2CF(CF3)OCF2CF2CH2OSO3M), CH2=CH(O(CF2)4CH2OSO3M), CF2=CF(OCF2CF2SO2N(CH3)CH2CH2OSO3M), CH2=CH(OCF2CF2CH2OSO3M), CF2=CF(OCF2CF2CF2CF2SO2N(CH3)CH2CH2OSO3M), CH2=CH(OCF2CF2CF2CH2OSO3M), etc. In the above formulas, M is the same as described above.

[0136] In general formula (I), A 0 Using a sulfonate group is also a preferred method. As A 0 For example, it is -SO3M, where M is the same as above.

[0137] In A 0 In the case of a sulfonate group, examples of monomers represented by general formula (I) include CF2=CF(OCF2CF2SO3M), CF2=CF(O(CF2)3SO3M), CF2=CF(O(CF2)4SO3M), CF2=CF(OCF2CF(CF3)SO3M), CF2=CF(OCF2CF(CF3)OCF2CF2SO3M), CH2=CH(OCF2CF2SO3M), CF2=CF(OCF2CF(CF3)OCF2CF2CF2CF2SO3M), CH2=CH(O(CF2)4SO3M), CH2=CH(O(CF2)3SO3M), etc. In the above formulas, M is the same as described above.

[0138] In general formula (I), A 0 Using a carboxylate group is also a preferred method. As A 0 For example, it can be COOM or SO2NR'CH2COOM, where R' is H or an alkyl group with 1 to 4 carbon atoms, and M is the same as above. A 0 In the case of a carboxyl group, examples of monomers represented by general formula (I) include CF2=CF(OCF2CF2COOM), CF2=CF(O(CF2)3COOM), CF2=CF(O(CF2)4COOM), CF2=CF(O(CF2)5COOM), CF2=CF(OCF2CF(CF3)COOM), and CF2=CF(OCF2CF(CF3)O(CF2)).n COOM) (n is greater than 1), CH2=CH(OCF2CF2COOM), CH2=CH(O(CF2)4COOM), CH2=CH(O(CF2)3COOM), CF2=CF(OCF2C F2SO2NR'CH2COOM), CF2=CF(O(CF2)4SO2NR'CH2COOM), CF2=CF(OCF2CF(CF3)SO2NR'CH2COOM), CF2=C F(OCF2CF(CF3)OCF2CF2SO2NR'CH2COOM), CH2=CH(OCF2CF2SO2NR'CH2COOM), CF2=CF(OCF2CF(CF3)OC F2CF2CF2CF2SO2NR'CH2COOM), CH2=CH(O(CF2)4SO2NR'CH2COOM), CH2=CH(O(CF2)3SO2NR'CH2COOM), etc. In the above formula, R' is H or an alkyl group having 1 to 4 carbon atoms, and M is the same as above.

[0139] In general formula (I), A 0 Using phosphate groups is also a preferred method. As A 0 For example, -CH2OP(O)(OM)2, [-CH2O]2P(O)(OM), -CH2CH2OP(O)(OM)2, [-CH2CH2O]2P(O)(OM), [-SO2NR'CH2CH2O]2P(O)(OM) or SO2NR'CH2CH2OP(O)(OM)2, where R' is an alkyl group with 1 to 4 carbon atoms, and M is the same as above.

[0140] A 0 In the case of phosphate groups, examples of monomers represented by general formula (I) include CF2=CF(OCF2CF2CH2OP(O)(OM)2), CF2=CF(O(CF2)4CH2OP(O)(OM)2), CF2=CF(OCF2CF(CF3)CH2OP(O)(OM)2), CF2=CF(OCF2CF(CF3)OCF2CF2CH2OP(O)(OM)2), CF2=CF(OCF2CF2SO2N(CH3)CH2CH2OP(O)(OM)2), CF2=CF(OCF2CF2CF2CF2SO2N(CH3)CH2CH2OP(O)(OM)2), CH2=CH(OCF2CF2CH2OP(O)(OM)2), CH2=CH(O(CF2)4CH2OP(O)(OM)2), CH2=CH(O(CF2)3CH2OP(O)(OM)2), etc. In the above formula, M is the same as above.

[0141] In general formula (I), A 0 Phosphonate groups are also a preferred option. A 0 In the case of phosphonate groups, examples of monomers represented by general formula (I) include CF2=CF(OCF2CF2P(O)(OM)2), CF2=CF(O(CF2)4P(O)(OM)2), CF2=CF(OCF2CF(CF3)P(O)(OM)2), CF2=CF(OCF2CF(CF3)OCF2CF2P(O)(OM)2), CH2=CH(OCF2CF2P(O)(OM)2), CH2=CH(O(CF2)4P(O)(OM)2), and CH2=CH(O(CF2)3P(O)(OM)2), where M is the same as above.

[0142] The monomer (I) is preferably the monomer (1) shown in general formula (1).

[0143] The polymer (I) is preferably a polymer (1) comprising a polymer unit (1) based on a monomer represented by the general formula (1).

[0144] CX2=CY(-CZ2-O-Rf-A) (1)

[0145] (In the formula, X may be the same or different, and is -H or F; Y may be -H, -F, alkyl, or fluoroalkyl; Z may be the same or different, and is -H, -F, alkyl, or fluoroalkyl. Rf is a fluoroalkylene group with 1 to 40 carbon atoms, or a fluoroalkylene group with ether bonds having 2 to 100 carbon atoms. A is -COOM, -SO3M, -OSO3M, or -C(CF3)2OM (M is -H, a metal atom, or -NR).) 7 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 7 (It is an H or organic group.) Wherein, at least one of X, Y, and Z contains a fluorine atom.

[0146] The polymer (1) can be a homopolymer of the monomer (1) shown in general formula (1) or a copolymer of other monomers.

[0147] The aforementioned fluorinated alkylene groups with 2 to 100 carbon atoms and ether bonds are alkylene groups that do not have oxygen atoms at the end but contain ether bonds between carbon atoms.

[0148] In general formula (1), X is -H or F. X can be both -F or at least one -H. For example, one can be -F and the other can be -H, or both can be -H.

[0149] In general formula (1), Y is -H, -F, alkyl, or fluorinated alkyl. The alkyl group is an alkyl group without fluorine atoms, and has 1 or more carbon atoms. The alkyl group preferably has 6 or fewer carbon atoms, more preferably 4 or fewer, and even more preferably 3 or fewer. The fluorinated alkyl group is an alkyl group containing at least one fluorine atom, and has 1 or more carbon atoms. The fluorinated alkyl group preferably has 6 or fewer carbon atoms, more preferably 4 or fewer, and even more preferably 3 or fewer. Y is preferably -H, -F, or CF3, more preferably -F.

[0150] In general formula (1), Z can be the same or different, and can be -H, -F, alkyl, or fluoroalkyl. The alkyl group is an alkyl group without fluorine atoms, and has 1 or more carbon atoms. The alkyl group preferably has 6 or fewer carbon atoms, more preferably 4 or fewer, and even more preferably 3 or fewer. The fluoroalkyl group is an alkyl group containing at least one fluorine atom, and has 1 or more carbon atoms. The fluoroalkyl group preferably has 6 or fewer carbon atoms, more preferably 4 or fewer, and even more preferably 3 or fewer. Z is preferably -H, -F, or CF3, more preferably -F.

[0151] In general formula (1), at least one of X, Y and Z contains a fluorine atom. For example, X could be -H and Y and Z could be -F.

[0152] In general formula (1), Rf is a fluorinated alkylene group with 1 to 40 carbon atoms, or a fluorinated alkylene group with ether bonds with 2 to 100 carbon atoms.

[0153] The number of carbon atoms in the aforementioned fluorinated alkylene group is preferably 2 or more. Furthermore, the number of carbon atoms in the aforementioned fluorinated alkylene group is preferably 30 or less, more preferably 20 or less, further preferably 10 or less, particularly preferably 6 or less, and most preferably 3 or less. Examples of the aforementioned fluorinated alkylene group include -CF2-, -CH2CF2-, -CF2CF2-, -CF2CH2-, -CF2CF2CF2-, -CF2CF2CH2-, -CF(CF3)-, -CF(CF3)CF2-, and -CF(CF3)CH2-. The aforementioned fluorinated alkylene group is preferably a perfluorinated alkylene group.

[0154] The fluorinated alkylene group having an ether bond preferably has 3 or more carbon atoms. Furthermore, the fluorinated alkylene group having an ether bond preferably has 60 or fewer carbon atoms, more preferably 30 or fewer, further preferably 12 or fewer, particularly preferably 9 or fewer, and most preferably 6 or fewer. The fluorinated alkylene group having an ether bond can be, for example, derived from the general formula: [Chemical Formula 1] , (where Z) 1 For F or CF3; Z 2 and Z 3H or F respectively; Z 4 The divalent group is H, F, or CF3; p1+q1+r1 is an integer from 1 to 10; s1 is 0 or 1; t1 is an integer from 0 to 5.

[0155] Specifically, examples of fluorinated alkylene groups with ether bonds include -CF2CF(CF3)OCF2-, -CF(CF3)CF2-O-CF(CF3)-, and -(CF(CF3)CF2-O). n -CF(CF3)- (where n is an integer from 1 to 10), -CF(CF3)CF2-O-CF(CF3)CH2-, -(CF(CF3)CF2-O) n -CF(CF3)CH2- (where n is an integer from 1 to 10), -CH2CF2CF2O-CH2CF2CH2-, -CF2CF2CF2O-CF2-, -CF2CF2CF2O-CF2CF2-, -CF2CF2CF2O-CF2CF2-, -CF2CF2CF2O-CF2CF2CF2-, -CF2CF2CF2O-CF2CF2CH2-, -CF2CF2O-CF2-, -CF2CF2O-CF2CH2-, etc. The fluorinated alkylene groups with ether bonds mentioned above are preferably perfluoroalkylene groups.

[0156] In general formula (1), A is -COOM, -SO3M, -OSO3M or -C(CF3)2OM (M is H, metal atom, NR) 7 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 7 (H or organic groups).

[0157] As R 7 H or C are preferred 1-10 Organic groups, more preferably H or C 1-4 The organic groups, preferably H or C, are preferred. 1-4 Alkyl groups.

[0158] Examples of metal atoms include alkali metals (Group 1) and alkaline earth metals (Group 2), with Na, K, or Li being preferred.

[0159] As M, H, a metal atom, or NR are preferred. 7 4. More preferably, H, alkali metals (Group 1), alkaline earth metals (Group 2), or NR. 7 4. Further preferred materials are H, Na, K, Li or NH4, even more preferred materials are H, Na, K or NH4, particularly preferred materials are H, Na or NH4, and most preferred materials are H or NH4.

[0160] As A, -COOM or -SO3M is preferred.

[0161] As a monomer represented by general formula (1), for example, general formula (1a) is exemplified: CX2=CFCF2-O-(CF(CF3)CF2O) n5 -CF(CF3)-A (1a) (In the formula, each X is the same, representing F or H. n5 represents 0 or an integer from 1 to 10, and A is defined as above.) This represents the monomer shown.

[0162] In general formula (1a), from the viewpoint of obtaining particles with small primary particle size, n5 is preferably an integer from 0 or 1 to 5, more preferably 0, 1 or 2, and even more preferably 0 or 1.

[0163] The polymer (1) can be a homopolymer of the monomers represented by the general formula (1a) or a copolymer of other monomers.

[0164] The monomer (1) is preferably the monomer shown in general formula (1A).

[0165] The polymerization unit (1) is preferably a polymerization unit (1A) based on the monomer shown in general formula (1A).

[0166] CH2=CF(-CF2-O-Rf-A) (1A)

[0167] (In the formula, Rf and A are the same as above.)

[0168] The polymer (1) can be a homopolymer of the monomers represented by the general formula (1A) or a copolymer of other monomers.

[0169] As the monomer shown in formula (1A), specifically, the general formula can be cited.

[0170] [Chemical Formula 2] , (where Z) 1 For F or CF3; Z 2 and Z 3 H or F respectively; Z 4 Let H, F, or CF3 be the integers p1+q1+r1 from 0 to 10; s1 be 0 or 1; t1 be an integer from 0 to 5, where Z 3 and Z 4 When all are H, p1+q1+r1+s1 is not 0; A is defined the same as above. (The monomer is shown.) More specifically, the following can be preferred examples: [Chemical Formula 3] wait, Among them, the preferred option is: [Chemical Formula 4] .

[0171] As the monomer represented by general formula (1A), A in formula (1A) is preferably -COOM, particularly preferably at least one selected from the group consisting of CH2=CFCF2OCF(CF3)COOM and CH2=CFCF2OCF(CF3)CF2OCF(CF3)COOM (where M is the same as defined above), more preferably CH2=CFCF2OCF(CF3)COOM.

[0172] In addition, as a monomer shown in general formula (1), other monomers such as those shown in the following formula can also be cited.

[0173] CF2=CFCF2-O-Rf-A

[0174] (In the formula, Rf and A are the same as above.)

[0175] More specifically, examples include: [Chemical Formula 5] wait.

[0176] The monomer (I) is also preferably the monomer (2) shown in general formula (2).

[0177] Polymer (I) is also preferably a polymer (2) comprising a polymer unit (2) based on a monomer shown in general formula (2).

[0178] CX2=CY(-O-Rf-A) (2)

[0179] (In the formula, X may be the same or different, and can be -H or F; Y can be -H, -F, alkyl or fluorinated alkyl; Rf can be a fluorinated alkylene group with 1 to 40 carbon atoms, or a fluorinated alkylene group with 2 to 100 carbon atoms and having an ether bond or a ketone group; A is the same as above.)

[0180] The polymer (2) can be a homopolymer of the monomers shown in general formula (2) or a copolymer of other monomers.

[0181] In general formula (2), X is -H or F. X can be both -F or at least one -H. For example, one can be -F and the other can be -H, or both can be -H.

[0182] In general formula (2), Y is -H, -F, alkyl, or fluoroalkyl. An alkyl group is an alkyl group without fluorine atoms, and has 1 or more carbon atoms. The alkyl group preferably has 6 or fewer carbon atoms, more preferably 4 or fewer, and even more preferably 3 or fewer. A fluoroalkyl group is an alkyl group containing at least one fluorine atom, and has 1 or more carbon atoms. The fluoroalkyl group preferably has 6 or fewer carbon atoms, more preferably 4 or fewer, and even more preferably 3 or fewer. Y is preferably -H, -F, or CF3, more preferably -F.

[0183] In general formula (2), preferably at least one of X and Y contains a fluorine atom. For example, X can be -H, and Y and Z can be -F.

[0184] In general formula (2), Rf is a fluorinated alkylene group with 1 to 40 carbon atoms, a fluorinated alkylene group with ether bonds having 2 to 100 carbon atoms, or a fluorinated alkylene group with ketone groups having 2 to 100 carbon atoms. It should be noted that the fluorinated alkylene group with ether bonds having 2 to 100 carbon atoms is an alkylene group without oxygen atoms at the end but with ether bonds between carbon atoms.

[0185] The number of carbon atoms in the fluorinated alkylene group of Rf is preferably 2 or more. Furthermore, it is preferably 30 or less, more preferably 20 or less, even more preferably 10 or less, and particularly preferably 5 or less. Examples of fluorinated alkylene groups include -CF2-, -CH2CF2-, -CF2CF2-, -CF2CH2-, -CF2CF2CH2-, -CF(CF3)-, -CF(CF3)CF2-, -CF(CF3)CH2-, -CF2CF2CF2-, CF2CF2CF2CF2-, etc. The fluorinated alkylene group is preferably a perfluoroalkylene group, more preferably an unbranched, straight-chain perfluoroalkylene group.

[0186] The fluorinated alkylene group having an ether bond preferably has 3 or more carbon atoms. Furthermore, the fluorinated alkylene group having an ether bond preferably has 60 or fewer carbon atoms, more preferably 30 or fewer, even more preferably 12 or fewer, and particularly preferably 5 or fewer. The fluorinated alkylene group having an ether bond is also preferably of the general formula: [Chemical Formula 6] , (where Z) 1 For F or CF3; Z 2 and Z 3 H or F respectively; Z 4 The divalent group is H, F, or CF3; p1+q1+r1 is an integer from 1 to 10; s1 is 0 or 1; t1 is an integer from 0 to 5.

[0187] Specifically, examples of fluorinated alkylene groups with ether bonds include -CF2CF(CF3)OCF2-, -CF2CF(CF3)OCF2CF2-, -CF2CF(CF3)OCF2CF2CF2-, -CF(CF3)CF2-O-CF(CF3)-, and -(CF(CF3)CF2-O). n -CF(CF3)- (where n is an integer from 1 to 10), -CF(CF3)CF2-O-CF(CF3)CH2-, -(CF(CF3)CF2-O) n -CF(CF3)CH2- (where n is an integer from 1 to 10), -CH2CF2CF2O-CH2CF2CH2-, -CF2CF2CF2O-CF2-, -CF2CF2CF2O-CF2CF2-, -CF2CF2CF2O-CF2CF2-, -CF2CF2CF2O-CF2CF2CF2-, -CF2CF2CF2O-CF2CF2CH2-, -CF2CF2O-CF2-, -CF2CF2O-CF2CH2-, etc. The fluorinated alkylene groups with ether bonds mentioned above are preferably perfluoroalkylene groups.

[0188] The fluorinated alkylene group having a ketone group preferably has 3 or more carbon atoms. Furthermore, the fluorinated alkylene group having a ketone group preferably has 60 or fewer carbon atoms, more preferably 30 or fewer, even more preferably 12 or fewer, and particularly preferably 5 or fewer.

[0189] Examples of fluorinated alkylene groups having a ketone group include -CF2CF(CF3)CO-CF2-, -CF2CF(CF3)CO-CF2CF2-, -CF2CF(CF3)CO-CF2CF2CF2-, and -CF2CF(CF3)CO-CF2CF2CF2CF2-. The preferred fluorinated alkylene groups having a ketone group are perfluoroalkylene groups.

[0190] Water can also be added to the ketone group in the fluorinated alkylene group. Therefore, monomer (2) can be a hydrate. Examples of fluorinated alkylene groups that have water added to the ketone group include -CF2CF(CF3)C(OH)2-CF2-, -CF2CF(CF3)C(OH)2-CF2CF2-, -CF2CF(CF3)C(OH)2-CF2CF2CF2-, and -CF2CF(CF3)C(OH)2-CF2CF2CF2CF2-.

[0191] The monomer represented by general formula (2) is preferably at least one selected from the group consisting of monomers represented by general formulas (2a), (2b), (2c), (2d), (2e), (2f) and (2g).

[0192] CF2 = CF - O - (CF2)n1 -A (2a)

[0193] (In the formula, n1 represents an integer from 1 to 10, and A is the same as above.)

[0194] CF2 = CF-O - (CF2C(CF3)F) n2 -A (2b)

[0195] (In the formula, n2 represents an integer from 1 to 5, and A is defined as above.)

[0196] CF2=CF-O-(CFX 1 ) n3 -A (2c)

[0197] (where X) 1 Let F or CF3 represent n3, where n3 represents an integer from 1 to 10, and A is defined the same as above.

[0198] CF2=CF-O-(CF2CFX 1 O) n4 -(CF2) n6 -A (2d)

[0199] (In the formula, n4 represents an integer from 1 to 10, n6 represents an integer from 1 to 3, and A and X) 1 Same as the definition above.

[0200] CF2=CF-O-(CF2CF2CFX 1 O) n5 -CF2CF2CF2-A (2e)

[0201] (In the formula, n5 represents an integer from 0 to 10, and A and X) 1 Same as the definition above.

[0202] CF2 = CF - O - (CF2) n7 -O-(CF2) n8 -A (2f)

[0203] (In the formula, n7 represents an integer from 1 to 10, and n8 represents an integer from 1 to 3. A is defined the same as above.)

[0204] CF2 = CF[OCF2CF(CF3)] n9 O(CF2) n10 O[CF(CF3)CF2O] n11 CF(CF3)-A (2g)

[0205] (In the formula, n9 represents an integer from 0 to 5, n10 represents an integer from 1 to 8, and n11 represents an integer from 0 to 5. A is defined the same as above.)

[0206] In general formula (2a), n1 is preferably an integer of 5 or less, and more preferably an integer of 2 or less.

[0207] Examples of monomers represented by general formula (2a) include CF2=CF-O-CF2COOM, CF2=CF(OCF2CF2COOM), CF2=CF(O(CF2)3COOM), CF2=CF(OCF2CF2SO3M), CF2=CFOCF2SO3M, and CF2=CFOCF2CF2CF2SO3M (where M is defined as above).

[0208] In general formula (2b), from the perspective of the dispersion stability of the obtained composition, n2 is preferably an integer of 3 or less.

[0209] In general formula (2c), from the perspective of water solubility, n3 is preferably an integer of 5 or less, A is preferably -COOM, and M is preferably H, Na or NH4.

[0210] In general formula (2d), considering the dispersion stability of the composition, X 1 Preferably, -CF3 is used. Considering water solubility, n4 is preferably an integer of 5 or less, A is preferably -COOM, and M is preferably H, Na, or NH4.

[0211] Examples of monomers represented by the general formula (2d) include CF2=CFOCF2CF(CF3)OCF2CF2COOM, CF2=CFOCF2CF(CF3)OCF2COOM, CF2=CFOCF2CF(CF3)OCF2CF2CF2COOM, CF2=CFOCF2CF(CF3)OCF2SO3M, CF2=CFOCF2CF(CF3)OCF2CF2SO3M, and CF2=CFOCF2CF(CF3)OCF2CF2CF2SO3M (where M represents H, NH4, or an alkali metal).

[0212] In general formula (2e), from the perspective of water solubility, n5 is preferably an integer less than or equal to 5, A is preferably -COOM, and M is preferably H or NH4.

[0213] As a monomer represented by the general formula (2e), examples include CF2=CFOCF2CF2CF2COOM (where M represents H, Na, NH4 or an alkali metal).

[0214] In general formula (2f), from the perspective of water solubility, n7 is preferably an integer of 5 or less, A is preferably -COOM or -SO3M, more preferably -COOM. M is preferably H, Na, K or NH4.

[0215] As a monomer represented by the general formula (2f), examples include CF2=CF-O-(CF2)3-O-CF2-COOM (where M represents H, NH4 or an alkali metal).

[0216] In the general formula (2g), considering water solubility, n9 is preferably an integer of 3 or less, n10 is preferably an integer of 3 or less, n11 is preferably an integer of 3 or less, A is preferably -COOM or -SO3M, more preferably -COOM. M is preferably H, Na, K or NH4.

[0217] Examples of monomers represented by the general formula (2g) include CF2=CFO(CF2)2OCF(CF3)COOM, CF2=CFOCF2CF2OCF(CF3)CF2OCF(CF3)COOM, CF2=CFOCF2CF(CF3)OCF2CF2OCF(CF3)COOM, CF2=CF[OCF2CF(CF3)]2O(CF2)2O[CF(CF3)CF2O]CF(CF3)COOM, and CF2=CF[OCF2CF(CF3)]3O(CF2)2O[CF(CF3)CF2O]3CF(CF3)COOM (where M represents H, NH4 or an alkali metal).

[0218] The monomer (I) is also preferably the monomer (3) shown in general formula (3).

[0219] Polymer (I) is also preferably a polymer (3) comprising a polymer unit (3) based on a monomer shown in general formula (3).

[0220] CX2=CY(-Rf-A) (3)

[0221] (In the formula, X may be the same or different, and can be -H or F; Y can be -H, -F, alkyl, or fluoroalkyl; Rf can be a fluoroalkylene group with 1 to 40 carbon atoms, or a fluoroalkylene group with ether bonds having 2 to 100 carbon atoms. A is the same as above.)

[0222] The polymer (3) can be a homopolymer of the monomers shown in general formula (3) or a copolymer of other monomers.

[0223] It should be noted that fluorinated alkylene groups with ether bonds and 2 to 100 carbon atoms do not contain structures with oxygen atoms at the end; they are alkylene groups containing ether bonds between carbon atoms.

[0224] In general formula (3), Rf is preferably a fluorinated alkylene group having 1 to 40 carbon atoms. In general formula (3), preferably at least one of X and Y contains a fluorine atom.

[0225] The monomer shown in general formula (3) is preferably selected from general formula (3a): CF2 = CF - (CF2) n1 -A (3a) (In the formula, n1 represents an integer from 1 to 10, and A is defined as above) The single entity and general formula (3b) are shown: CF2 = CF - (CF2C(CF3)F) n2 -A (3b) (In the formula, n2 represents an integer from 1 to 5, and A is defined as above.) at least one of the groups consisting of the monomers shown.

[0226] In formulas (3a) and (3b), A is preferably -SO3M or COOM, and M is preferably H, a metal atom, or NR. 7 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphatonium with or without substituents. R 7 It represents H or an organic group.

[0227] In general formula (3a), n1 is preferably an integer of 5 or less, more preferably an integer of 2 or less. A is preferably -COOM, and M is preferably H or NH4.

[0228] As a monomer represented by the general formula (3a), examples include CF2=CFCF2COOM (where M is the same as defined above).

[0229] In general formula (3b), from the perspective of the dispersion stability of the obtained composition, n2 is preferably an integer of 3 or less, A is preferably -COOM, and M is preferably H or NH4.

[0230] Next, the preferred configuration for when m in general formula (I) is an integer greater than or equal to 2 will be explained.

[0231] The monomer (I) is preferably selected from at least one of the groups consisting of monomers represented by general formulas (4a) and (4b).

[0232] The polymer (I) is also preferably a polymer (4) comprising a polymer unit (4) based on at least one monomer selected from the group consisting of monomers shown in general formulas (4a) and (4b).

[0233] CF2 = CF - CF2 - OQ F1 -CF(-Q F2 -CZ 1 Z 2 -A)2 (4a)

[0234] (where Z) 1 Z 2A is defined the same as above, Q F1 and Q F2 (Whether the two are the same or different, they can be single bonds, fluorinated alkylene groups that may contain ether bonds between carbon atoms, or fluorinated oxyalkylene groups that may contain ether bonds between carbon atoms.)

[0235] CF2 = CF - OQ F1 -CF(-Q F2 -CZ 1 Z 2 -A)2 (4b)

[0236] (where Z) 1 Z 2 A, Q F1 and Q F2 Same as the definition above.

[0237] Examples of monomers represented by general formulas (4a) and (4b) include: [Chemical Formula 7] wait.

[0238] As monomer (I), it is preferably at least one selected from the group consisting of monomer (1), monomer (2) and monomer (3), more preferably monomer (1) or monomer (2), and even more preferably monomer (2).

[0239] Polymer (I) is preferably selected from at least one of the group consisting of polymer (1), polymer (2) and polymer (3), more preferably polymer (1) or polymer (2), and even more preferably polymer (2).

[0240] Polymer (I) can be a homopolymer consisting only of polymeric units (I), or a copolymer comprising polymeric units (I) and polymeric units based on other monomers capable of copolymerizing with monomers (I) represented by general formula (I). From the viewpoint of solubility in aqueous media, homopolymers consisting only of polymeric units (I) are preferred. The polymeric units (I) may be the same or different each time they appear, and polymer (I) may contain polymeric units (I) based on monomers represented by two or more different general formulas (I).

[0241] As other monomers mentioned above, monomers with the general formula CFR=CR2 (where R is independently H, F, or a perfluoroalkyl group having 1 to 4 carbon atoms) are preferred. Additionally, monomers with fluorinated olefinic bonds having 2 or 3 carbon atoms are preferred. Examples of other monomers include CF2=CF2, CF2=CFCl, CH2=CF2, CFH=CH2, CFH=CF2, CF2=CFCF3, CH2=CFCF3, CH2=CHCF3, CHF=CHCF3 (E form), and CHF=CHCF3 (Z form).

[0242] From the perspective of good copolymerization, it is preferable to select at least one from the group consisting of tetrafluoroethylene (CF2=CF2), trifluorochloroethylene (CF2=CFCl), and vinylidene fluoride (CH2=CF2), and more preferably at least one from the group consisting of tetrafluoroethylene and vinylidene fluoride. Therefore, the polymerization unit based on the above-mentioned other monomers is preferably a polymerization unit based on tetrafluoroethylene. The polymerization units based on the above-mentioned other monomers may be the same or different each time they appear, and the polymer (I) may contain polymerization units based on two or more different other monomers.

[0243] In addition, as other monomers mentioned above, the general formula (n1-2) can also be cited: [Chemical Formula 8] , (where X) 1 X 2 Same or different, indicated by H or F; X 3 For example, H, F, Cl, CH3 or CF3; X 4 X 5 If they are the same or different, the value is H or F; if a and c are the same or different, the value is 0 or 1. Rf 3 The monomer is a fluorinated alkyl group having 1 to 40 carbon atoms or a fluorinated alkyl group having ether bonds having 2 to 100 carbon atoms.

[0244] Specifically, CH2=CFCF2-O-Rf can be preferred as an example. 3 CF2 = CF-O-Rf 3 CF2=CFCF2-O-Rf 3 CF2 = CF - Rf 3 CH2=CH-Rf 3 CH2=CH-O-Rf 3 (where Rf) 3 (Same as the above formula (n1-2) etc.)

[0245] As other monomers mentioned above, equation (n²-1) can also be cited: [Chemical Formula 9] , (where X) 9 For H, F, or CH3; Rf 4 Fluorinated acrylate monomers are those consisting of a fluorinated alkyl group having 1 to 40 carbon atoms or a fluorinated alkyl group having an ether bond having 2 to 100 carbon atoms. The above Rf... 4 Examples of bases include: [Chemical Formula 10] , (where Z) 8 (where H, F, or Cl are used; d1 is an integer from 1 to 4; e1 is an integer from 1 to 10) , (In the formula, e2 is an integer from 1 to 5) , (In the formula, d3 is an integer from 1 to 4; e3 is an integer from 1 to 10) etc.

[0246] As another example of the aforementioned monomers, equation (n²-2) can also be cited: CH2=CHO-Rf 5 (n2-2) (where Rf) 5 Fluorinated vinyl ethers are fluorinated alkyl groups having 1 to 40 carbon atoms or fluorinated alkyl groups having ether bonds having 2 to 100 carbon atoms.

[0247] Specifically, as a monomer of the general formula (n²-2), the following are preferred examples: [Chemical Formula 11] , (where Z) 9 (e4 is an integer from 1 to 10) , (In the formula, e5 is an integer from 1 to 10) , (In the formula, e6 is an integer from 1 to 10) etc.

[0248] More specifically, examples can be given.

[0249] [Chemical Formula 12] wait.

[0250] In addition, the general formula (n²-3) can be cited: CH2=CHCH2O-Rf 6 (n2-3) (where Rf) 6 Fluorinated allyl ethers, general formula (n2-4), are fluoroalkyl groups having 1 to 40 carbon atoms or fluoroalkyl groups having 2 to 100 carbon atoms and containing ether bonds. CH2=CH-Rf 7 (n2-4) (where Rf) 7Fluorinated vinyl monomers, etc., are fluorinated alkyl groups having 1 to 40 carbon atoms or fluorinated alkyl groups having ether bonds having 2 to 100 carbon atoms.

[0251] Specifically, as monomers represented by general formulas (n2-3) and (n2-4), examples can be given as follows: [Chemical Formula 13] Monomers, etc.

[0252] Polymer (I) typically has terminal groups. These terminal groups are those generated during polymerization, and representative terminal groups are independently selected from hydrogen, iodine, bromine, chain-like or branched alkyl groups, and chain-like or branched fluoroalkyl groups, and may optionally contain at least one additional chain-like heteroatom. The number of carbon atoms in the alkyl or fluoroalkyl group is preferably 1 to 20. These terminal groups are typically generated by an initiator or chain transfer agent used to form polymer (I), or generated in a chain transfer reaction.

[0253] In polymer (I), the content of polymeric unit (I) relative to all polymeric units is preferably 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. Particularly preferably, the content of polymeric unit (I) is substantially 100 mol%, and most preferably, polymer (I) consists solely of polymeric unit (I).

[0254] In polymer (I), the content of polymerization units based on other monomers capable of copolymerizing with the monomers shown in general formula (I), relative to all polymerization units, is preferably 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. The content of polymerization units based on other monomers capable of copolymerizing with the monomers shown in general formula (I) is particularly preferably substantially 0 mol%, and polymer (I) most preferably contains no polymerization units based on other monomers.

[0255] In polymers (1), (2), or (3), the content of polymeric unit (1), polymeric unit (2), or polymeric unit (3) relative to all polymeric units is preferably 1.0 mol% or more, 3.0 mol% or more, 5.0 mol% or more, 10 mol% or more, 20 mol% or more, 30 mol% or more, 40 mol% or more, 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, or 90 mol% or more. The content of polymeric unit (1), polymeric unit (2), or polymeric unit (3) is particularly preferably substantially 100 mol%, and polymers (1), polymers (2), or polymers (3) are most preferably composed solely of polymeric unit (2) or polymeric unit (3).

[0256] In polymer (1), polymer (2), or polymer (3), the content of polymeric units based on other monomers that can copolymerize with polymeric unit (1), polymeric unit (2), or polymeric unit (3), relative to all polymeric units, is preferably 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. The content of polymeric units based on other monomers that can copolymerize with polymeric unit (1), polymeric unit (2), or polymeric unit (3) is particularly preferably substantially 0 mol%, and polymer (1), polymer (2), or polymer (3) most preferably does not contain polymeric units based on other monomers.

[0257] Regarding the number-average molecular weight of polymer (I), it is preferably greater than 0.1 × 10⁻⁶, since polymer (I) can be recovered at a higher rate. 4 0.2×10 4 Above, 0.3×10 4 Above, 0.4×10 4 Above, 0.5×10 4 Above, 1.0×10 4 Above, 3.0×10 4 Above, or 3.1 × 10 4 That's all. Furthermore, the number-average molecular weight of polymer (I) is preferably 75.0 × 10⁻⁶. 4 Below, 50.0×10 4 Below, 40.0×10 4 Below, 30.0×10 4 Below, or 20.0×10 4 the following.

[0258] The weight-average molecular weight of polymer (I) is preferably 0.2 × 10⁻⁶. 4Above, 0.4×10 4 Above, 0.6×10 4 Above, 0.8×10 4 Above, 1.0×10 4 Above, 2.0×10 4 Above, 5.0×10 4 Above, 10.0×10 4 Above, 15.0×10 4 Above, 20.0×10 4 Above, or 25.0 × 10 4 That's all. Furthermore, the weight-average molecular weight of polymer (I) is preferably 150.0 × 10⁻⁶. 4 Below, 100.0×10 4 Below, 60.0×10 4 Below, 50.0×10 4 Below, or 40.0×10 4 the following.

[0259] The number-average molecular weight and weight-average molecular weight of polymer (I) were calculated using monodisperse polystyrene as a standard by gel permeation chromatography (GPC). Alternatively, when GPC is not feasible, the number-average molecular weight of polymer (I) can be determined based on 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 determined according to JIS K 7210.

[0260] Regarding the number average molecular weight of polymer (1), polymer (2), or polymer (3), it is preferably greater than 0.1 × 10⁻⁶, since polymer (1), polymer (2), or polymer (3) can be recovered with a higher recovery rate. 4 0.2×10 4 Above, 0.3×10 4 Above, 0.4×10 4 Above, 0.5×10 4 Above, 1.0×10 4 Above, 3.0×10 4 Above, or 3.1 × 10 4 That's all. Furthermore, the number-average molecular weight of polymer (1), polymer (2), or polymer (3) is preferably 75.0 × 10⁻⁶. 4 Below, 50.0×10 4 Below, 40.0×10 4 Below, 30.0×10 4 Below, or 20.0×10 4 the following.

[0261] The weight-average molecular weight of polymer (1), polymer (2), or polymer (3) is preferably 0.2 × 10⁻⁶. 4 Above, 0.4×10 4 Above, 0.6×10 4 Above, 0.8×10 4 Above, 1.0×10 4 Above, 2.0×10 4 Above, 5.0×10 4 Above, 10.0×10 4 Above, 15.0×10 4 Above, 20.0×10 4 Above, or 25.0 × 10 4 That's all. Furthermore, the weight-average molecular weight of polymer (1), polymer (2), or polymer (3) is preferably 150.0 × 10⁻⁶. 4 Below, 100.0×10 4 Below, 60.0×10 4 Below, 50.0×10 4 Below, or 40.0×10 4 the following.

[0262] The number-average molecular weight and weight-average molecular weight of polymers (1), (2), or (3) were calculated using monodisperse polystyrene as a standard by gel permeation chromatography (GPC). Alternatively, if GPC is not feasible, the number-average molecular weight of polymers (1), (2), or (3) can be determined based on 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 determined according to JIS K 7210.

[0263] Polymer (I) preferably has an ion exchange rate (IXR) of 53 or less. The IXR is defined as the number of carbon atoms in the polymer backbone relative to the ionic group. Precursor groups that become ionic through hydrolysis (e.g., -SO2F) are not considered ionic groups for the purpose of determining the IXR.

[0264] The IXR of polymer (I) is preferably 0.5 or more, 1 or more, 3 or more, 4 or more, 5 or more, or 8 or more. Furthermore, the IXR of polymer (I) is preferably 43 or less, 33 or less, or 23 or less.

[0265] The preferred ion exchange capacity of polymer (I) is 0.80 meq / g or higher, 1.50 meq / g or higher, 1.75 meq / g or higher, 2.00 meq / g or higher, 2.20 meq / g or higher, exceeding 2.20 meq / g, 2.50 meq / g or higher, 2.60 meq / g or higher, 3.00 meq / g or higher, or 3.50 meq / g or higher. The ion exchange capacity is the content of ionic groups (anionic groups) in polymer (I), calculated from the composition of polymer (I).

[0266] In polymer (I), ionic groups (anionic groups) are typically distributed along the polymer backbone. The polymer (I) comprises a polymer backbone and repeating side chains bonded to the backbone, the side chains preferably having ionic groups.

[0267] Polymer (I) preferably contains ionic groups having a pKa of less than 10, more preferably less than 7. The ionic groups of polymer (I) are preferably selected from the group consisting of sulfonates, carboxylates, phosphonates and phosphates.

[0268] The terms "sulfonate, carboxylate, phosphonate, and phosphate" refer to their respective salts or their respective acids capable of forming salts. When using salts, alkali metal salts or ammonium salts are preferred. The preferred ionic group is the sulfonate group.

[0269] In addition, as a water-soluble fluoropolymer, it can be used

[0270] General formula: T X -O-[R f 1 -O] n1 [R f 2 -O] n2 -T X’

[0271] (in the formula, T x and T X’ Each is independently selected from at least one of the following groups: a (hydro) (fluoro) hydrocarbon group having 1 to 24 carbon atoms having one or more ionic groups (X), and a (hydro) (fluoro) hydrocarbon group having 1 to 24 carbon atoms having one or more of H, O and Cl (excluding groups having ionic groups (X)). R f 1 It can be the same or different each time it appears, and it is a perfluoroalkylene group with 1 to 7 carbon atoms; R f 2It may be the same or different each time it appears, and is a perfluoroalkylene group with 1 to 11 carbon atoms having one or more ionic groups (X); n1 and n2 are integers greater than or equal to 1; The ionic group (X) is selected from -SO3X a -PO3X a and -COOX a (X a A multifunctional fluoropolyether dispersant comprising at least one of the group consisting of H, ammonium, or monovalent metals.

[0272] T in the formula X T X’ R f 1 R f 2 n1 and n2 are combined in such a way that the number average molecular weight is within the above range.

[0273] In the general formula representing multifunctional fluoropolyether dispersants, -R is the repeating unit. f 1 Examples of -O- include -CF2CF2O-, -CFYO-, -CF2CFYO-, -CF2O-, and -CF2(CF2). z CF2O- (where Y is a fluoro(oxy)alkyl group with 1 to 5 carbon atoms; z is 1 or 2), etc.

[0274] In the general formula representing multifunctional fluoropolyether dispersants, -R is the repeating unit. f 2 -O-, for example -CF2CF(G x )O-、-CF(G x O-、-CF2(CF2) x1 CF(G x (CF2) x2 O-(where G is the formula) x It is a perfluoro(oxy)alkyl group having 1 to 5 carbon atoms and having one or more ionic groups (X), wherein X1 and X2 are independently integers from 0 to 3, and the sum of X1 and X2 is 1 or more, etc.

[0275] As T x and T X’ Examples can be given as follows:

[0276] -CFZ -COOX a -CFZ CH2-COOX a or -CFZ -CH2(OCH2CH2)k -COOX a (where Z) F or CF3; k is an integer from 0 to 10; X a Ionic groups (represented by H, ammonium, or monovalent metals) Nonionic (per)fluoroalkyl groups (e.g., -CF2Cl, -CF3, etc.) containing or not containing one or more of H, O, and Cl, with 1 to 3 carbon atoms.

[0277] Examples of such multifunctional fluorinated polyether dispersants include, for instance, the dispersant (D) described in International Publication No. 2019 / 048394.

[0278] In addition, fluoropolyether acid or its salts can be used as water-soluble fluoropolymers.

[0279] Examples of fluoropolyether acids include those having repeating units as shown in any of formulas (11a) to (11d).

[0280] (-CFCF3-CF2-O-) n (11a)

[0281] (-CF2-CF2-CF2-O-) n (11b)

[0282] (-CF2-CF2-O-) n -(-CF2-O-) m (11c)

[0283] (-CF2-CFCF3-O-) n -(-CF2-O-) m (11d)

[0284] (In the formula, m and n are integers greater than or equal to 1.)

[0285] In the formula, m and n are integers greater than or equal to 1, and are combined in a manner that ensures the number-average molecular weight is within the above range.

[0286] Fluoroether acids can have acid groups or acid-base groups at one or both ends. For monofunctional fluoroether acids with an acid group or acid-base group at one end, the other end of the molecule is usually perfluorinated, but may also contain hydrogen or chlorine atoms.

[0287] Fluoroether acids are preferably carboxylic acids, sulfonic acids, sulfonamides, or phosphonic acids, and more preferably carboxylic acids. Among fluoroether acids or their salts, salts of fluoroether acids are preferred, ammonium salts of fluoroether acids are more preferred, and ammonium salts of fluoroether carboxylic acids are even more preferred.

[0288] As such a fluoropolyether acid or its salt, the following formula is preferred: CF3-CF2-CF2-O(-CFCF3-CF2-O-) n CFCF3-COOH, CF3-CF2-CF2-O(-CF2-CF2-CF2-O-) n -CF2-CF2COOH or HOOC-CF2-O(-CF2-CF2-O-) n -(-CF2-O-) m CF2COOH (In the formula, m and n are the same as above.) The compound or its salt is indicated.

[0289] Examples of fluoropolyether acids or their salts include, for example, those described in International Publication No. 2000 / 071590 and International Publication No. 2008 / 060461.

[0290] The embodiments have been described above, but it is understood that various changes can be made to the methods and details without departing from the spirit and scope of the claims.

[0291] <1> According to the first aspect of this disclosure, a method for recovering water-soluble fluoropolymers is provided, which involves processing polymers containing a number average molecular weight exceeding 0.1 × 10⁻⁶. 4 A composition of a water-soluble fluoropolymer and water is mixed with a cationic polymer, and the water-soluble fluoropolymer is recovered from the composition.

[0292] <2> According to a second aspect of this disclosure, a recovery method based on the first aspect is provided, wherein the composition is mixed with the cationic polymer to generate a coagulant containing the water-soluble fluoropolymer and the cationic polymer, water is separated from the coagulant, thereby recovering the water-soluble fluoropolymer in the form of the coagulant.

[0293] <3> According to the third aspect of this disclosure, a recycling method based on the first or second aspect is provided, wherein the cationic polymer is at least one selected from the group consisting of polyethyleneimine, poly(diallyl dimethylammonium) and its salts, poly(trimethylaminoethyl methacrylate) and its salts, poly(dimethylaminoethyl methacrylate), dimethylamine-epimyl chlorohydrin condensate, dicyandiamide-formaldehyde condensate, and dicyandiamide-diethylenetriamine condensate.

[0294] <4> According to the fourth aspect of this disclosure, a recovery method based on any one of the first to third aspects is provided, wherein the amount of the cationic polymer is 1% to 10,000% by mass relative to the mass of the water-soluble fluoropolymer.

[0295] <5> According to the fifth aspect of this disclosure, a recovery method based on any one of the first to fourth aspects is provided, wherein the number average molecular weight of the water-soluble fluoropolymer is 0.3 × 10⁻⁶. 4 above.

[0296] <6> According to the sixth aspect of this disclosure, a recycling method based on any one of the first to fifth aspects is provided, wherein the water-soluble fluoropolymer has ionic groups.

[0297] <7> According to the seventh aspect of this disclosure, a recycling method based on any one of the first to sixth aspects is provided, wherein the water-soluble fluoropolymer is a polymer (I) comprising a polymeric unit (I) based on a monomer (I) represented by general formula (I).

[0298] General formula (I): CX 1 X 3 =CX 2 R(-CZ 1 Z 2 -A 0 ) m (I)

[0299] (where X) 1 and X 3 Each is independently F, Cl, H or CF3; X 2 It is H, F, alkyl, or fluorinated alkyl; A 0 R is an anionic group; R is a linking group; Z is an anionic group. 1 and Z 2 Each is independently H, F, alkyl, or fluoroalkyl; m is an integer greater than or equal to 1.

[0300] <8> According to the eighth aspect of this disclosure, a recycling method based on the seventh aspect is provided, wherein the number-average molecular weight of polymer (I) is 0.3 × 10⁻⁶. 4 above.

[0301] <9> According to the ninth point of this disclosure, a recycling method based on the seventh or eighth point is provided, wherein the ion exchange rate of the polymer (I) is 53 or less.

[0302] <10> According to the 10th aspect of this disclosure, a recycling method based on any one of the 1st to 9th aspects is provided, wherein the content of the water-soluble fluoropolymer in the composition is more than 0% by mass and less than 1% by mass relative to the mass of the composition.

[0303] <11> According to the 11th aspect of this disclosure, a recovery method based on any one of the 1st to 10th aspects is provided, wherein the recovery rate of the water-soluble fluoropolymer is 99.0% by mass or more.

[0304] <12> According to the 12th aspect of this disclosure, a recycling method based on any one of the 1st to 11th aspects is provided, wherein the water-soluble fluoropolymer is at least one selected from the group consisting of a polymer (1) comprising a polymeric unit (1) based on a monomer represented by general formula (1) and a polymer (2) comprising a polymeric unit (2) based on a monomer represented by general formula (2), wherein the content of polymeric unit (1) in polymer (1) is 90 mol% or more relative to all polymeric units in polymer (1), and the content of polymeric unit (2) in polymer (2) is 90 mol% or more relative to all polymeric units in polymer (2). The number-average molecular weight of the water-soluble fluoropolymer is 0.3 × 10⁻⁶. 4 ~20.0×10 4 , The water-soluble fluoropolymer in the composition comprises 0.020% to 0.2% by mass. The cationic polymer is polyethyleneimine. The amount of the cationic polymer is 30% to 500% by mass relative to the mass of the water-soluble fluoropolymer.

[0305] CX2=CY(-CZ2-O-Rf-A) (1)

[0306] (In the formula, X may be the same or different, and is -H or F; Y may be -H, -F, alkyl, or fluoroalkyl; Z may be the same or different, and is -H, -F, alkyl, or fluoroalkyl. Rf is a fluoroalkylene group with 1 to 40 carbon atoms, or a fluoroalkylene group with ether bonds having 2 to 100 carbon atoms. A is -COOM, -SO3M, -OSO3M, or -C(CF3)2OM (M is -H, a metal atom, or -NR).) 7 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 7 (It is an H group or an organic group.)

[0307] CX2=CY(-O-Rf-A) (2)

[0308] (In the formula, X may be the same or different, and can be -H or F; Y can be -H, -F, alkyl or fluorinated alkyl; Rf can be a fluorinated alkylene with 1 to 40 carbon atoms, or a fluorinated alkylene with ether or ketone groups with 2 to 100 carbon atoms; A can be -COOM, -SO3M, -OSO3M or -C(CF3)2OM (M can be -H, metal atom, -NR) 7 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 7 (It is an H group or an organic group.)

[0309] <13> According to the 13th aspect of this disclosure, a recycling method based on any of the 1st to 12th aspects is provided, wherein a composition containing the water-soluble fluoropolymer and water is mixed with an inorganic coagulant. The composition containing the water-soluble fluoropolymer, water, and the inorganic coagulant is mixed with the cationic polymer. The composition containing the water-soluble fluoropolymer, water, the inorganic coagulant, and the cationic polymer is mixed with at least one selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers. The resulting aggregate comprises the water-soluble fluoropolymer, the inorganic coagulant, the cationic polymer, and at least one selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers. The water is separated from the condensate.

[0310] Example

[0311] Next, embodiments will be given to illustrate the implementation of this disclosure, but this disclosure is not limited to the embodiments described.

[0312] The values ​​in the examples were measured using the following methods.

[0313] <Molecular weight of water-soluble fluoropolymers>

[0314] The molecular weights of polymers 1–4 were determined by GPC.

[0315] <Concentration of water-soluble fluoropolymers>

[0316] The concentrations of polymers 1–4 were determined using liquid chromatography (LC) with a charged particle detector manufactured by Thermo Fisher Scientific.

[0317] <Concentration of perfluorooctanoic acid>

[0318] The concentration of perfluorooctanoic acid (PFOA) was determined using liquid chromatography (LC) with a UV detector at a detection wavelength of 210 nm.

[0319] Example 1

[0320] Under stirring, 5 g of a 10% (w / w) aqueous solution of polyethyleneimine was added to 1 L of an aqueous solution containing 1000 ppm of CF2=CFOCF2COOH homopolymer (polymer 1) with a number average molecular weight of 18000. Immediately after addition, a turbid solution was obtained. The solid and liquid components were separated by centrifugation, and the liquid fraction was determined by liquid chromatography (LC). The results showed that the concentration of polymer 1 was less than 1 ppm. Therefore, it can be concluded that polymer 1 can be recovered with a high recovery rate by recovering the solid fraction.

[0321] Example 2

[0322] Under stirring, 4 g of a 10% (w / w) aqueous solution of polyethyleneimine was added to 1 L of an aqueous solution of a homopolymer (polymer 2) containing CF2=CFOCF2CF2SO3H with a number average molecular weight of 15000 and 1000 ppm by mass. A turbid solution was obtained, and the solid and liquid components were separated by centrifugation. The liquid fraction was determined by LC. The results showed that the concentration of polymer 2 was less than 1 ppm by mass.

[0323] Example 3

[0324] Under stirring, 2 g of a 10% (w / w) aqueous solution of polyethyleneimine was added to 1 L of an aqueous solution of polymer 1 containing 430 ppm by mass and a number-average molecular weight of 18000. Immediately after addition, a turbid solution was obtained. The solid and liquid components were separated by centrifugation, and the liquid fraction was determined by LC. The results showed that the concentration of polymer 1 was less than 1 ppm by mass.

[0325] Example 4

[0326] 1 g of a 10% (w / w) aluminum sulfate aqueous solution was added to 1 L of an aqueous solution containing polymer 1 (430 ppm by mass) with a number-average molecular weight of 18000. After stirring, 2 g of a solution containing EPOMIN P-1000 (manufactured by Nippon Shokubai Co., Ltd.) with a solid content adjusted to 10% (w / w) was added, and the mixture was stirred for 1 minute. White flocculent material was produced. Stirring was stopped, and the mixture was allowed to stand for 1 hour to allow the flocculent material to settle. The supernatant was collected, and the concentration of polymer 1 was determined by LC. The results showed that the concentration of polymer 1 was less than 1 ppm by mass.

[0327] Example 5

[0328] Add 3g of a 10% (w / w) aluminum sulfate aqueous solution to 1L of an aqueous solution containing polymer 2 with a number average molecular weight of 15000 and a concentration of 860 ppm by mass. After stirring, add 3g of a solution of EPOMIN P-3000 (manufactured by Nippon Shokubai Co., Ltd.) with a solid component concentration adjusted to 10% by mass, and stir for 1 minute. White flocculent material is produced. Stop stirring and allow the mixture to stand for 1 hour to allow the flocculent material to settle. Collect the supernatant and determine the concentration of polymer 2 by LC. The results show that the concentration of polymer 2 is less than 1 ppm by mass.

[0329] Example 6

[0330] 2.5 g of a 10% (w / w) aluminum sulfate aqueous solution was added to 1 L of an aqueous solution containing polymer 2 with a number average molecular weight of 15000 and a concentration of 290 ppm (w / w). After stirring, 2.5 g of a solution containing EPOMIN P-3000 (manufactured by Nippon Shokubai Co., Ltd.) adjusted to a solid content of 10% (w / w) was added, and the mixture was stirred for 1 minute. The solution became turbid. Stirring was stopped, and the solution remained turbid after standing for 1 hour. Then, 2 g of an aqueous solution containing an anionic polymeric coagulant (ACCOFLOC A-110, manufactured by MT AquaPolymer Co., Ltd.) adjusted to a concentration of 0.1% (w / w) was added, and the mixture was stirred. White flocculants were produced. Stirring was stopped, and the solution was allowed to stand for 1 hour to allow the flocculants to settle. The supernatant was collected, and the concentration of polymer 2 was determined by LC. The concentration of polymer 2 was found to be 1.9 ppm (w / w).

[0331] Example 7

[0332] 3 g of 10% aluminum sulfate aqueous solution was added to 1 L of an aqueous solution containing polymer 2 with a number average molecular weight of 15000 and a mass of 430 ppm. After stirring, 1 g of a solution containing EPOMIN P-3000 (manufactured by Nippon Shokubai Co., Ltd.) with a solid component concentration adjusted to 10% was added, and the mixture was stirred for 1 minute. The solution became turbid. Stirring was stopped, and the solution remained turbid even after standing for 1 hour. 0.05 g of an anionic polymeric coagulant (manufactured by Technica Goudou Co., Ltd., Water Flock A-71) was added to the solution and stirred. White flocculants were produced. Stirring was stopped, and the solution was allowed to stand for 1 hour to allow the flocculants to settle. The supernatant was collected, and the concentration of polymer 2 was determined by LC. The concentration of polymer 2 was found to be less than 1 ppm.

[0333] Example 8

[0334] Under stirring, 4 g of a 10% (w / w) aqueous solution of polyethyleneimine was added to 1 L of an aqueous solution of a homopolymer (polymer 3) containing CF2=CFOCF2CF2SO3H with a number average molecular weight of 5300 and 1000 ppm by mass. A turbid solution was obtained, and the solid and liquid components were separated by centrifugation. The liquid fraction was determined by LC. The concentration of polymer 3 was 1.5 ppm by mass.

[0335] Example 9

[0336] 995 kg of an aqueous solution containing 630 ppm of polymer 3 was added to a 1000 L coagulation tank with stirring blades and stirred. 754 g of a 27% aluminum sulfate aqueous solution was added while stirring, followed by 640 g of EPOMINP-3000 (manufactured by Nippon Shokubai Co., Ltd.), causing solids to precipitate. Then, 15 g of WaterFlock L N-52B (manufactured by Technica Goudou Co., Ltd.) was added while stirring for 10 minutes. The liquid in the coagulation tank was fed to a BDN006 sedimentation centrifuge (manufactured by Bakosei Co., Ltd.) using a Mohno PumpNEL16PUN (manufactured by Hyoshin Equipment Co., Ltd.), and solid-liquid separation was performed at a centrifugal force of 2100 G. The results showed that the concentration of polymer 3 in the separated water was less than 1 ppm, the suspended solids (SS) concentration was 18 mg / L, and the sludge moisture content was 90% by mass.

[0337] Example 10

[0338] Under stirring, 1.4 g of a 10% (w / w) aqueous solution of polyethyleneimine was added to 1 L of a homopolymer (polymer 4) containing 400 ppm of CH2=CFCF2OCF(CF3)COOH with a number average molecular weight of 122000. White flocculents were formed. Stirring was stopped, and the mixture was allowed to settle for 1 hour. The supernatant was collected, and the concentration of polymer 4 was determined by LC. The results showed that the concentration of polymer 4 was less than 1 ppm (w / w).

[0339] Comparative Example 1

[0340] While stirring, an aqueous solution of anionic polymeric coagulant (manufactured by MT AquaPolymer, ACCOFLOC A-110) was added in 5 portions (4g each time) to a total concentration of 1% (w / w) to polymer 1 containing 430 ppm by mass of polymer 1 with a number average molecular weight of 18000. From 4g to 20g, the solution remained colorless and transparent during the addition process, and no precipitate was observed. After adding 20g, stirring was stopped, and no precipitate was observed after standing for 1 hour.

[0341] Comparative Example 2

[0342] While stirring, an aqueous solution of a nonionic polymeric coagulant (ORGANO, ORFLOCK ON-1H) was added in 5 portions (4g each time) to a 1L solution of polymer 1 with a number average molecular weight of 15000, in which 4g was added to adjust the concentration to 1% by mass. From 4g to 20g, the solution remained colorless and transparent during the addition process, and no precipitate was observed. After adding 20g, stirring was stopped, and no precipitate was observed after standing for 1 hour.

[0343] Comparative Example 3

[0344] 10 g of 10% aluminum sulfate aqueous solution was added to 1 L of a solution containing 1000 ppm of polymer 1 with a number average molecular weight of 15000. The solution was then neutralized to pH 8 with 1 mol / L sodium hydroxide aqueous solution while stirring. A white, translucent precipitate was observed. After standing for 1 hour, the supernatant was collected, and the concentration of polymer 1 was determined by LC. The result showed that the concentration of polymer 1 was 640 ppm.

[0345] Comparative Example 4

[0346] Under stirring, 6 g of a 10% (w / w) aqueous solution of polyethyleneimine was added to 1 L of a solution containing 1000 ppm perfluorooctanoic acid (PFOA), and the mixture was stirred for 1 minute. A turbid solution was obtained, and the solid and liquid components were separated using a centrifuge. The liquid fraction was determined by LC. The concentration of PFOA was 99 ppm (w / w).

Claims

1. A method for recovering water-soluble fluoropolymers, comprising, by means of polymers containing a number average molecular weight exceeding 0.1 × 10⁻⁶... 4 A composition of a water-soluble fluoropolymer and water is mixed with a cationic polymer, and the water-soluble fluoropolymer is recovered from the composition.

2. The recycling method according to claim 1, wherein, The composition is mixed with the cationic polymer to generate a coagulant containing the water-soluble fluoropolymer and the cationic polymer. Water is separated from the coagulant, thereby recovering the water-soluble fluoropolymer in the form of the coagulant.

3. The recycling method according to claim 1 or 2, wherein, The cationic polymer is selected from at least one group consisting of polyethyleneimine, poly(diallyl dimethylammonium) and its salts, poly(trimethylaminoethyl methacrylate) and its salts, poly(dimethylaminoethyl methacrylate), dimethylamine-epimyl chlorohydrin condensate, dicyandiamide-formaldehyde condensate, and dicyandiamide-diethylenetriamine condensate.

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

5. The recycling method according to any one of claims 1 to 4, wherein, The number-average molecular weight of the water-soluble fluoropolymer is 0.3 × 10⁻⁶. 4 above.

6. The recycling method according to any one of claims 1 to 5, wherein, The water-soluble fluoropolymer has ionic groups.

7. The recycling method according to any one of claims 1 to 6, wherein, The water-soluble fluoropolymer is a polymer (I) comprising polymeric units (I) based on monomers (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 Each is independently F, Cl, H or CF3; X 2 It is H, F, alkyl, or fluorinated alkyl; A 0 R is an anionic group; R is a linking group; Z is an anionic group. 1 and Z 2 Each is independently H, F, alkyl, or fluorinated alkyl; m is an integer greater than or equal to 1.

8. The recycling method according to claim 7, wherein, The number-average molecular weight of polymer (I) is 0.3 × 10⁻⁶. 4 above.

9. The recycling method according to claim 7 or 8, wherein, The ion exchange rate of polymer (I) is below 53.

10. The recycling method according to any one of claims 1 to 9, wherein, The content of the water-soluble fluoropolymer in the composition is greater than 0% by mass and less than 1% by mass relative to the mass of the composition.

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

12. The recycling method according to any one of claims 1 to 11, wherein, The water-soluble fluoropolymer is at least one selected from the group consisting of polymer (1) comprising a polymer unit (1) based on a monomer shown in general formula (1) and polymer (2) comprising a polymer unit (2) based on a monomer shown in general formula (2), wherein the content of polymer unit (1) in polymer (1) is 90 mol% or more relative to all polymer units in polymer (1), and the content of polymer unit (2) in polymer (2) is 90 mol% or more relative to all polymer units in polymer (2). The number-average molecular weight of the water-soluble fluoropolymer is 0.3 × 10⁻⁶. 4 ~20.0×10 4 , The water-soluble fluoropolymer in the composition comprises 0.020% to 0.2% by mass. The cationic polymer is polyethyleneimine. The amount of the cationic polymer relative to the mass of the water-soluble fluoropolymer is 30% to 500% by mass. CX2=CY(-CZ2-O-Rf-A) (1) In the formula, X may be the same or different and is -H or F; Y may be -H, -F, alkyl or fluoroalkyl; Z may be the same or different and is -H, -F, alkyl or fluoroalkyl; Rf may be a fluoroalkylene group with 1 to 40 carbon atoms, or a fluoroalkylene group with ether bonds with 2 to 100 carbon atoms; A may be -COOM, -SO3M, -OSO3M or -C(CF3)2OM, where M may be -H, a metal atom, or -NR. 7 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 7 It is an H or an organic group. CX2=CY(-O-Rf-A) (2) In the formula, X may be the same or different, and can be -H or F; Y can be -H, -F, alkyl or fluorinated alkyl; Rf can be a fluorinated alkylene with 1 to 40 carbon atoms, or a fluorinated alkylene with 2 to 100 carbon atoms and an ether bond or ketone group; A can be -COOM, -SO3M, -OSO3M or -C(CF3)2OM, where M can be -H, a metal atom, or -NR. 7 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 7 It is an H or an organic group.

13. The recycling method according to any one of claims 1 to 12, wherein, The composition containing the water-soluble fluoropolymer and water is mixed with an inorganic coagulant. The composition containing the water-soluble fluoropolymer, water, and the inorganic coagulant is mixed with the cationic polymer. The composition containing the water-soluble fluoropolymer, water, the inorganic coagulant, and the cationic polymer is mixed with at least one selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers. The resulting aggregate comprises the water-soluble fluoropolymer, the inorganic coagulant, the cationic polymer, and at least one selected from the group consisting of anionic polymers, nonionic polymers, and amphoteric polymers. The water is separated from the condensate.

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