Method for producing fluoropolymers and aqueous dispersions

Abstract

To provide a method for producing a fluoropolymer with a small content of a fluorine-containing compound having a hydrophilic group.SOLUTION: Provided is a method for producing a fluoropolymer in which a fluoropolymer is obtained by polymerizing a fluoromonomer in the presence of a polymerization initiator, a telogenic compound, and an aqueous medium, wherein the polymerization initiator is a polymerization initiator that generates a hydrophobic primary radical.SELECTED DRAWING: None

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to methods for making fluoropolymers and aqueous dispersions. [Background technology]

[0002] Patent Document 1 describes a process for producing a fluoropolymer, which comprises preparing an aqueous mixture containing a perfluorinated monomer, a fluoroalkylsulfinic acid or its salt having 1 to 3 carbon atoms in the fluoroalkyl group, and an oxidizing agent capable of oxidizing the fluoroalkylsulfinic acid or its salt, and polymerizing the perfluorinated monomer under free radical conditions to prepare an aqueous dispersion of a fluoropolymer, wherein the amount of perfluorooctanoic acid or its salt in the aqueous dispersion of the fluoropolymer after polymerization is 25 nanograms or less per gram of fluoropolymer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 180547 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a method for producing a fluoropolymer having a low content of a fluorine-containing compound having a hydrophilic group. [Means for solving the problem]

[0005] According to the present disclosure, there is provided a method for producing a fluoropolymer, in which a fluoropolymer is obtained by polymerizing a fluoromonomer in the presence of a polymerization initiator, a compound having telogenicity, and an aqueous medium, wherein the polymerization initiator is a polymerization initiator that generates hydrophobic primary radicals. [Effects of the Invention]

[0006] According to the present disclosure, a method for producing a fluoropolymer with a low content of a fluorine-containing compound having a hydrophilic group can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0007] Before specifically describing the present disclosure, some terms used in the present disclosure will be defined or explained.

[0008] In the present disclosure, fluororesins are partially crystalline fluoropolymers, or fluoroplastics. Fluororesins have a melting point and are thermoplastic, but may be melt-processable or non-melt-processable.

[0009] In the present disclosure, melt-processable means that the polymer can be melted and processed using conventional processing equipment such as an extruder, an injection molding machine, etc. Therefore, melt-processable fluororesins usually have a melt flow rate of 0.01 to 500 g / 10 min, as measured by the measurement method described below.

[0010] In this disclosure, fluoroelastomer refers to an amorphous fluoropolymer. "Amorphous" means that the magnitude of the melting peak (ΔH) appearing in differential scanning calorimetry (DSC) (heating rate 10°C / min) or differential thermal analysis (DTA) (heating rate 10°C / min) of the fluoropolymer is 4.5 J / g or less. Fluoroelastomers exhibit elastomeric properties through crosslinking. Elastomeric properties refer to the ability of a polymer to be stretched and to retain its original length when the force required to stretch the polymer is no longer applied.

[0011] In the present disclosure, polytetrafluoroethylene [PTFE] is preferably a fluoropolymer having a content of tetrafluoroethylene units relative to all polymerized units of 99 mol % or more.

[0012] In the present disclosure, both the fluororesin (excluding polytetrafluoroethylene) and the fluororubber are preferably fluoropolymers having a tetrafluoroethylene content of less than 99 mol% relative to all polymerized units.

[0013] In the present disclosure, the content of each monomer constituting the fluoropolymer can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and X-ray fluorescence analysis depending on the type of monomer.

[0014] In the present disclosure, the term "organic group" refers to a group containing one or more carbon atoms or a group formed by removing one hydrogen atom from an organic compound. The organic group is preferably an alkyl group which may have one or more substituents.

[0015] In this disclosure, ranges expressed by endpoints include all numbers subsumed within that range (eg, 1 to 10 includes 1.4, 1.9, 2.33, 5.75, 9.98, etc.).

[0016] In this disclosure, the term "at least 1" includes all numbers greater than or equal to 1 (e.g., at least 2, at least 4, at least 6, at least 8, at least 10, at least 25, at least 50, at least 100, etc.).

[0017] Specific embodiments of the present disclosure will be described in detail below, but the present disclosure is not limited to the following embodiments.

[0018] 1. Manufacturing method The present disclosure relates to a method for producing a fluoropolymer by polymerizing a fluoromonomer in the presence of a polymerization initiator, a compound having telogenicity, and an aqueous medium to obtain a fluoropolymer.

[0019] (Polymerization initiator) In the production method of the present disclosure, a polymerization initiator that generates hydrophobic primary radicals is used.

[0020] In this disclosure, primary radicals refer to radicals generated directly from a polymerization initiator (or an oxidizing agent and a reducing agent when the polymerization initiator is a redox initiator). Primary radicals include radicals generated directly by cleavage of the polymerization initiator, and, when the polymerization initiator is a redox initiator, radicals generated by cleavage of an oxidizing agent constituting the redox initiator (such as a sulfate radical generated by cleavage of ammonium persulfate) and a reducing agent (such as sodium trifluoromethanesulfinate) (such as a CF3SO2 radical or a CF3 radical). On the other hand, radicals generated by reaction of a radical generated directly from the polymerization initiator with a compound other than the polymerization initiator, such as a chain transfer agent or a fluoromonomer, are not included in primary radicals.

[0021] Primary radicals are usually generated under polymerization conditions, and therefore include primary radicals generated at the start of polymerization and primary radicals generated during polymerization.

[0022] With respect to radicals, hydrophobicity refers to the property of having low affinity with water. An example of a hydrophobic radical is a radical that bonds with a hydrogen atom abstracted from another compound (for example, a compound having telogenicity, such as a chain transfer agent or a hydrocarbon surfactant) to give a compound having a solubility in water of less than 1.0 mass % at 20°C. Another example of a hydrophobic radical is a radical that does not have a hydrophilic group. A hydrophilic group is a polar atomic group that has a high affinity with water, and examples thereof include -SO3M, -OSO3M, -COOM, -PO3M, -OPO3M, -NR2, -OH, and -NR3X (wherein M is a cation, R is H or an organic group, and X is an anion). Examples of hydrophilic groups include those contained in fluorine-containing compounds having hydrophilic groups, which will be described later. Examples of cations include H + , ammonium ions, alkali metal ions, alkaline earth metal ions, etc.

[0023] The generation of hydrophobic primary radicals can be determined, for example, by the 19This can be confirmed by F-solid-state NMR analysis. For example, when tetrafluoroethylene is polymerized using a redox initiator composed of sodium trifluoromethanesulfinate and ammonium persulfate as the polymerization initiator and ethane as the chain transfer agent, peaks derived from -CF3 and -CF2H groups are observed in the NMR spectrum of the fluoropolymer obtained by polymerization. It can be assumed that the -CF3 group is formed by the reaction of tetrafluoroethylene with radicals generated from the polymerization initiator, and the -CF2H group is formed by the bonding of the propagating radical with a hydrogen atom abstracted from ethane. Therefore, when a redox initiator composed of sodium trifluoromethanesulfinate and ammonium persulfate is used as the polymerization initiator, it is clear that CF3 radicals are generated from the polymerization initiator. When the same polymerization as above is performed, except that sodium trifluoromethanesulfinate is not used and only ammonium persulfate is used as the polymerization initiator, no peaks derived from -CF3 groups are observed in the NMR spectrum of the fluoropolymer obtained by polymerization. This indicates that when only ammonium persulfate is used as the polymerization initiator, hydrophobic primary radicals such as CF3 radicals are not generated. The generation of hydrophobic primary radicals can also be confirmed by analyzing oligomers contained in aqueous dispersions or fluoropolymers using GC-MS. For example, in the above example, the oligomers of the general formula: CF3-(CF2) n A compound represented by —H (wherein n is an integer of 0 or more) is detected.

[0024] The hydrophobic primary radical is preferably a non-perfluoroalkyl radical or a perfluoroalkyl radical, and more preferably a perfluoroalkyl radical. When the alkyl group of a non-perfluoroalkyl radical or a perfluoroalkyl radical has two or more carbon atoms, these radicals may have an oxygen atom between the two carbon atoms. "Non-perfluoroalkyl" includes "fluorine-free alkyl" and "partially fluorinated alkyl."

[0025] Furthermore, the hydrophobic primary radical is preferably a radical containing a carbon atom, more preferably a radical having 1 to 19 carbon atoms, still more preferably a non-perfluoroalkyl radical having 1 to 19 carbon atoms, a non-perfluoroalkyl radical having 2 to 19 carbon atoms and having an oxygen atom between two carbon atoms, a perfluoroalkyl radical having 1 to 19 carbon atoms, or a perfluoroalkyl radical having 2 to 19 carbon atoms and having an oxygen atom between two carbon atoms, and still more preferably a perfluoroalkyl radical having 1 to 19 carbon atoms.

[0026] Hydrophobic primary radicals include, for example: General formula: R 1 · (In the formula, R 1 represents a linear or branched non-perfluoroalkyl group having 1 to 7 carbon atoms or a linear or branched perfluoroalkyl group having 1 to 7 carbon atoms, and represents an unpaired electron. A radical represented by General formula: R 1 -OR 2 · (In the formula, R 1 and R 2 each independently represents a linear or branched non-perfluoroalkyl group having 1 to 6 carbon atoms or a linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, and represents an unpaired electron. or a radical represented by General formula: R 1 -OR 2 -OR 3 · (In the formula, R 1 , R 2 and R 3 each independently represents a linear or branched non-perfluoroalkyl group having 1 to 6 carbon atoms or a linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, and represents an unpaired electron. A radical represented by Examples include:

[0027] Furthermore, the hydrophobic primary radical is preferably a radical containing a carbon atom, more preferably a radical having 1 to 7 carbon atoms, even more preferably a non-perfluoroalkyl radical having 1 to 7 carbon atoms or a perfluoroalkyl radical having 1 to 7 carbon atoms, and even more preferably a perfluoroalkyl radical having 1 to 7 carbon atoms. When the alkyl group of the non-perfluoroalkyl radical and perfluoroalkyl radical has 2 or more carbon atoms, these radicals may have an oxygen atom between the two carbon atoms. The alkyl group of the non-perfluoroalkyl radical and the perfluoroalkyl radical preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and even more preferably 1 carbon atom.

[0028] In one embodiment, the hydrophobic primary radical is General formula: R 111 · (In the formula, R 111 represents a linear or branched non-perfluoroalkyl group having 1 to 7 carbon atoms or a linear or branched perfluoroalkyl group having 1 to 7 carbon atoms, and represents an unpaired electron. 111 The number of carbon atoms is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. A radical represented by General formula: R 112 -OR 113 · (In the formula, R 112 and R 113 R independently represents a linear or branched non-perfluoroalkyl group having 1 to 6 carbon atoms or a linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, and represents an unpaired electron. 112 and R 113 The total number of carbon atoms is 2 to 7, preferably 2 to 5, more preferably 2 or 3, and even more preferably 2. or a radical represented by General formula: R 114 -OR 115 -OR 116 · (In the formula, R 114, R 115 and R 116 R independently represents a linear or branched non-perfluoroalkyl group having 1 to 6 carbon atoms or a linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, and represents an unpaired electron. 114 , R 115 and R 116 The total number of carbon atoms is 3 to 7, preferably 3 to 5, and more preferably 3. A radical represented by is.

[0029] In one embodiment, the hydrophobic primary radical is General formula: R 111 · (In the formula, R 111 represents a linear or branched non-perfluoroalkyl group having 1 to 7 carbon atoms or a linear or branched perfluoroalkyl group having 1 to 7 carbon atoms, and represents an unpaired electron. 111 The number of carbon atoms is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. It is a radical represented by the formula:

[0030] In one embodiment, the hydrophobic primary radical is General formula: R 111 · (In the formula, R 111 represents a linear or branched perfluoroalkyl group having 1 to 7 carbon atoms, and represents an unpaired electron. 111 The number of carbon atoms is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. It is a radical represented by the formula:

[0031] Also, examples of hydrophobic primary radicals include: General formula: CF3-(CF2) n · (In the formula, n represents an integer of 0 to 6, and · represents an unpaired electron.) Examples of the radical include:

[0032] The polymerization initiator may be a hydrophobic polymerization initiator or a water-soluble polymerization initiator. The polymerization initiator is preferably a water-soluble polymerization initiator. A water-soluble polymerization initiator refers to a polymerization initiator having a solubility in water of 1.0% by mass or more at 20°C, for example. By using a water-soluble polymerization initiator to generate hydrophobic primary radicals and polymerize a fluoromonomer, the polymerization reaction proceeds smoothly and the by-production of hydrophilic compounds can be further suppressed. Alternatively, a water-soluble polymerization initiator means that a solution of at least 0.1% by mass or at least 0.01% by mass can be obtained under the conditions in which the reaction step is carried out. Using a water-insoluble initiator can cause aggregates to form during the polymerization reaction, making it difficult to obtain a good aqueous dispersion.

[0033] As the polymerization initiator, a redox initiator is preferred. The redox initiator is not particularly limited as long as it is an initiator composed of an oxidizing agent and a reducing agent, but a water-soluble redox initiator is preferred. A water-soluble redox initiator refers to an initiator composed of a water-soluble oxidizing agent and a water-soluble reducing agent. If a water-insoluble redox initiator is used, it may cause agglomerates to form during the polymerization reaction, making it impossible to obtain a good aqueous dispersion.

[0034] Examples of the reducing agent constituting the redox initiator include sulfinates, carboxylates, sulfites, bisulfites, diimines, oxalic acid, etc. Preferred examples include sulfinates, sulfites, bisulfites, diimines, oxalic acid, etc.

[0035] In one embodiment, the reducing agent that makes up the redox initiator is General formula: R 111 -SO2M (In the formula, R 111 represents a linear or branched non-perfluoroalkyl group having 1 to 7 carbon atoms or a linear or branched perfluoroalkyl group having 1 to 7 carbon atoms, and M represents a cation. 111 The number of carbon atoms is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. A compound represented by General formula: R 112 -OR 113 -SO2M (In the formula, R 112 and R 113 R independently represents a linear or branched non-perfluoroalkyl group having 1 to 6 carbon atoms or a linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, and M represents a cation. 112 and R 113 The total number of carbon atoms is 2 to 7, preferably 2 to 5, more preferably 2 or 3, and even more preferably 2. or a compound represented by General formula: R 114 -OR 115 -OR 116 -SO2M (In the formula, R 114 , R 115 and R 116 R independently represents a linear or branched non-perfluoroalkyl group having 1 to 5 carbon atoms or a linear or branched perfluoroalkyl group having 1 to 5 carbon atoms, and M represents a cation. 114 , R 115 and R 116 The total number of carbon atoms is 3 to 7, preferably 3 to 5, and more preferably 3. A compound represented by is.

[0036] In one embodiment, the reducing agent that makes up the redox initiator is General formula: R 111 -SO2M (In the formula, R 111 represents a linear or branched non-perfluoroalkyl group having 1 to 7 carbon atoms or a linear or branched perfluoroalkyl group having 1 to 7 carbon atoms, and M represents a cation. 111 The number of carbon atoms is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. It is a compound represented by the formula:

[0037] In one embodiment, the reducing agent that makes up the redox initiator is General formula: R 111 -SO2M (In the formula, R 111 represents a linear or branched perfluoroalkyl group having 1 to 7 carbon atoms, and M represents a cation. 111 The number of carbon atoms is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. It is a compound represented by the formula:

[0038] In the general formula of the reducing agent constituting the redox initiator, the cation is H + ammonium ions; metal ions such as alkali metal ions, alkaline earth metal ions, and zinc ions; and the like.

[0039] The reducing agent constituting the redox initiator is preferably a fluorine-containing alkylsulfinic acid or a salt thereof, more preferably a fluorine-containing alkylsulfinic acid having 1 to 7 carbon atoms or a salt thereof.

[0040] Examples of fluorine-containing alkylsulfinic acids or salts thereof include: General formula: CF3-(CF2) n -SO2M (In the formula, n represents an integer of 0 to 6, and M represents a cation.) Examples of the cation include compounds represented by H + , ammonium ions, alkali metal ions, alkaline earth metal ions, etc.

[0041] Examples of fluorine-containing alkylsulfinic acids or salts thereof include trifluoromethanesulfinic acid, sodium trifluoromethanesulfinate, ammonium trifluoromethanesulfinate, potassium trifluoromethanesulfinate, pentafluoroethanesulfinic acid, sodium pentafluoroethanesulfinate, ammonium pentafluoroethanesulfinate, potassium pentafluoroethanesulfinate, perfluoro-n-propanesulfinic acid, sodium perfluoro-n-propanesulfinate, and perfluoro-n-propanesulfinic acid. ammonium perfluoro-n-propanesulfinate, potassium perfluoro-n-propanesulfinate, perfluoroisopropanesulfinic acid, sodium perfluoroisopropanesulfinate, ammonium perfluoroisopropanesulfinate, potassium perfluoroisopropanesulfinate, 1,1-difluoromethanesulfinic acid, zinc 1,1-difluoromethanesulfinate (bis(difluoromethylsulfonyl)zinc), 1,1,2,2-tetrafluoroethanesulfinic acid, 1,1,2,2,3,3-hexafluoropentanesulfinic acid, and the like.

[0042] Examples of oxidizing agents that constitute redox initiators include persulfates, organic peroxides, permanganates, manganese triacetate, cerium (IV) salts, silver (II) salts, copper (II) salts, iron (III) salts, bromates, chlorates, hypochlorites, perphosphates, and perborates.

[0043] The oxidizing agent constituting the redox initiator is preferably an oxidizing agent capable of oxidizing a fluorine-containing alkylsulfinic acid or a salt thereof, more preferably a persulfate, a cerium (IV) salt, a silver (II) salt, a bromate, a chlorate, a hypochlorite, a perphosphate, a perborate, or a percarbonate, still more preferably a persulfate, and particularly preferably ammonium persulfate or potassium persulfate.

[0044] To increase the decomposition rate of the initiator, it is also preferable to add a metal salt such as a copper salt, an iron salt, or a silver salt to the combination of redox initiators. Examples of copper salts include copper(I) sulfate, examples of iron salts include iron(II) sulfate, and examples of silver salts include silver(I) nitrate.

[0045] For example, the reducing agent may be a compound of the general formula: 111 -SO2M(in the formula, R 111 represents a linear or branched perfluoroalkyl group having 1 to 7 carbon atoms, and M represents a cation. When tetrafluoroethylene (CF2=CF2) is polymerized using a compound represented by the formula (I) and ammonium persulfate as an oxidizing agent, General formula: R 111 -(CF2-CF2) n1 · (In the formula, R 111 is as above, n1 represents an integer of 1 to 3, and · represents an unpaired electron.) It is presumed that radicals represented by the following formula are produced.

[0046] The radicals thus generated are hydrophobic, and therefore do not produce hydrophilic compounds even when they react with other compounds (for example, compounds having telogenicity, such as chain transfer agents or hydrocarbon surfactants). Therefore, although the production method of the present disclosure polymerizes a fluoromonomer in the presence of a compound having telogenicity, it polymerizes the fluoromonomer using a polymerization initiator that generates hydrophobic primary radicals, and therefore hydrophilic compounds are less likely to be by-produced during polymerization.

[0047] The amount of the polymerization initiator to be added is determined appropriately depending on the type of monomer, the molecular weight of the target fluoropolymer, and the reaction rate. The amount of the polymerization initiator to be added is preferably 0.00001 to 10% by mass, more preferably 0.0001% by mass or more, even more preferably 0.001% by mass or more, particularly preferably 0.01% by mass or more, more preferably 5% by mass or less, and even more preferably 2% by mass or less, based on the aqueous medium.

[0048] When a redox initiator is used as the polymerization initiator, the amount of the reducing agent added is preferably 0.00001 to 10% by mass, more preferably 0.0001% by mass or more, even more preferably 0.001% by mass or more, particularly preferably 0.01% by mass or more, more preferably 5% by mass or less, and even more preferably 2% by mass or less, relative to the aqueous medium. The amount of the oxidizing agent added is adjusted depending on the amount of the reducing agent added.

[0049] The polymerization initiator may be added all at once at the start of polymerization, or may be added to initiate polymerization and then further added during polymerization. When a redox initiator is used as the polymerization initiator, either an oxidizing agent or a reducing agent may be charged into a polymerization vessel in advance, and then the other may be added continuously or intermittently to initiate polymerization. For example, when a fluorine-containing alkylsulfinic acid or its salt is used as the reducing agent and a persulfate is used as the oxidizing agent, a fluorine-containing alkylsulfinic acid or its salt can be added to the polymerization system, and then the persulfate can be continuously added thereto.

[0050] (Telogenic compounds) In the production method of the present disclosure, polymerization is carried out in the presence of a compound having telogenicity, which is preferably at least one compound selected from the group consisting of chain transfer agents and hydrocarbon surfactants.

[0051] It has now been found that in conventional fluoropolymer production methods, when fluoromonomers are polymerized in the presence of a compound having telogenicity, fluorine-containing compounds having hydrophilic groups are produced. In the production method disclosed herein, fluoromonomers are polymerized in the presence of a compound having telogenicity using a polymerization initiator that generates hydrophobic primary radicals, thereby suppressing the by-production of fluorine-containing compounds having hydrophilic groups and enabling the production of fluoropolymers with high purity. This eliminates the need for additional methods to reduce the content of fluorine-containing compounds having hydrophilic groups. It is presumed that this is because fluorine-containing compounds having hydrophilic groups are produced by the generation of water-soluble radicals from the polymerization initiator.

[0052] (chain transfer agent) As the chain transfer agent, for example, a hydrocarbon compound having 1 to 6 carbon atoms is used.

[0053] Examples of chain transfer agents include esters such as dimethyl malonate, diethyl malonate, methyl acetate, ethyl acetate, butyl acetate, and dimethyl succinate, as well as isopentane, methane, ethane, propane, methanol, isopropanol, acetone, various mercaptans, various halogenated hydrocarbons such as carbon tetrachloride, and cyclohexane.

[0054] Among them, the chain transfer agent is preferably a non-halogenated alkane having 2 to 4 carbon atoms. Specifically, at least one selected from the group consisting of methane, ethane, propane, butane, and isobutane is more preferred, and at least one selected from the group consisting of ethane and propane is even more preferred.

[0055] The amount of the chain transfer agent used is usually preferably 1 to 50,000 ppm by mass, more preferably 1 to 20,000 ppm by mass, even more preferably 1 to 10,000 ppm by mass, and still more preferably 1 to 5,000 ppm by mass, relative to the total amount of fluoromonomers supplied.

[0056] The chain transfer agent may be added all at once to the reaction vessel before the initiation of polymerization, may be added all at once after the initiation of polymerization, may be added in multiple divided portions during the polymerization, or may be added continuously during the polymerization.

[0057] (surfactant) The surfactant may be either a fluorine-containing surfactant or a hydrocarbon-based surfactant. In the production method of the present disclosure, a hydrocarbon-based surfactant can be used. Although hydrocarbon-based surfactants exhibit telogenicity, the production method of the present disclosure can suppress the by-production of hydrophilic compounds.

[0058] (hydrocarbon surfactants) The hydrocarbon-based emulsifier is a non-fluorine-containing hydrocarbon-based emulsifier. Examples of hydrocarbon-based surfactants that can be used include those described in JP-A Nos. 2013-542308, 2013-542309, and 2013-542310.

[0059] The hydrocarbon surfactants may be surfactants having a hydrophilic portion and a hydrophobic portion on the same molecule, and may be cationic, nonionic, or anionic.

[0060] Cationic hydrocarbon surfactants typically have a positively charged hydrophilic portion, such as an alkylated ammonium halide, such as an alkylated ammonium bromide, and a hydrophobic portion, such as a long-chain fatty acid.

[0061] Examples of the anionic hydrocarbon surfactant include carboxylic acid or a salt thereof, sulfonic acid or a salt thereof, and sulfuric acid or a salt thereof. Anionic hydrocarbon surfactants typically have a hydrophilic portion, such as a carboxylic acid, carboxylate, sulfonic acid, sulfonate, sulfuric acid, or sulfate, and a hydrophobic portion, which is a long-chain hydrocarbon portion, such as an alkyl.

[0062] Nonionic hydrocarbon surfactants typically contain no charged groups and have a hydrophobic portion that is a long hydrocarbon chain. The hydrophilic portion of the nonionic surfactant contains a water-soluble functional group, such as an ethylene ether chain derived from polymerization with ethylene oxide.

[0063] Examples of nonionic hydrocarbon surfactants Polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, glycerol esters, and derivatives thereof.

[0064] Specific examples of polyoxyethylene alkyl ethers include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, and polyoxyethylene behenyl ether.

[0065] Specific examples of polyoxyethylene alkylphenyl ethers include polyoxyethylene nonylphenyl ether and polyoxyethylene octylphenyl ether.

[0066] Specific examples of polyoxyethylene alkyl esters include polyethylene glycol monolaurate, polyethylene glycol monooleate, and polyethylene glycol monostearate.

[0067] Specific examples of sorbitan alkyl esters include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, and polyoxyethylene sorbitan monooleate.

[0068] Specific examples of polyoxyethylene sorbitan alkyl esters include polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, and polyoxyethylene sorbitan monostearate.

[0069] Specific examples of glycerol esters include glycerol monomyristate, glycerol monostearate, and glycerol monooleate.

[0070] Specific examples of the above derivatives include polyoxyethylene alkylamines, polyoxyethylene alkylphenyl-formaldehyde condensates, polyoxyethylene alkyl ether phosphates, and the like.

[0071] The ethers and esters may have an HLB value of 10-18.

[0072] Examples of nonionic hydrocarbon surfactants include the Triton (registered trademark) X series (X15, X45, X100, etc.), Tergitol (registered trademark) 15-S series, Tergitol (registered trademark) TMN series (TMN-6, TMN-10, TMN-100, etc.), and Tergitol (registered trademark) L series, all manufactured by The Dow Chemical Company; the Pluronic (registered trademark) R series (31R1, 17R2, 10R5, 25R4 (m-22, n-23)) and the Iconol (registered trademark) TDA series (TDA-6, TDA-9, TDA-10), all manufactured by BASF.

[0073] Examples of anionic hydrocarbon surfactants include Versatic (registered trademark) 10 manufactured by Resolution Performance Products and Avanel S series (S-70, S-74, etc.) manufactured by BASF.

[0074] The anionic hydrocarbon surfactant is not particularly limited as long as it is an anionic surfactant that does not have a fluorine atom, but General formula (X):R Z -(LM) x (In the formula, R Z represents a hydrophobic hydrocarbon moiety containing one or more carbon atoms, L, which may be the same or different in each occurrence, represents an ionic hydrophilic moiety, and M, which may be the same or different in each occurrence, represents one or more counter ions of the ionic hydrophilic moiety. x represents the number of groups represented by -LM bonded to Rz and is an integer of 1 to 3.

[0075] R Z As the hetero group, a hydrocarbon group having 1 to 100 carbon atoms which may contain a heteroatom is preferred. The heteroatom may be inserted between carbon atoms, or may be contained in a substituent bonded to a carbon atom. L is -ArSO3 - , -ArSO4 - , -SO3 - , -SO4-, -PO3- or -COO - -ArSO3 - is an aryl sulfonate. -ArSO4 - is an aryl sulfate. M can be H, a metal atom, or NR 5Z 4. An imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent is preferred. 5Z is preferably H or an organic group (preferably an alkyl group having 1 to 3 carbon atoms). More specifically, the anionic hydrocarbon surfactants described below can be mentioned.

[0076] The hydrocarbon surfactants include R Z -LM (where R Z is a monovalent organic group containing one or more carbon atoms. L is -ArSO3 - , -SO3 - , -SO4-, -PO3 - or -COO - and M is H, a metal atom, or NR 5Z 4. An imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, R 5Z is H or an organic group, -ArSO3 - is an aryl sulfonate. ) Specifically, CH3-(CH2) such as lauric acid and lauryl sulfate (dodecyl sulfate) n -LM (wherein n is an integer of 6 to 17, and L and M are the same as above). R Z R may be a linear or branched alkyl group having 1 or more carbon atoms which may have a substituent, or a cyclic alkyl group having 3 or more carbon atoms which may have a substituent. Z When the alkyl group has 3 or more carbon atoms, it may contain a monovalent or divalent heterocycle or may form a ring. R ZA mixture in which is an alkyl group having 12 to 16 carbon atoms and LM is a sulfate may also be used. Other surfactant compounds include R 6Z (-LM)2(wherein, R 6Z is a monovalent organic group containing one or more carbon atoms. L is -ArSO3 - , -SO3 - , -SO4-, -PO3 - or -COO - and M is H, a metal atom, or NR 5Z 4. An imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, R 5Z is H or an organic group, -ArSO3 - is an aryl sulfonate. ) R 6Z R may be a linear or branched alkylene group having 1 or more carbon atoms which may have a substituent, or a cyclic alkylene group having 3 or more carbon atoms which may have a substituent. 6Z When the alkylene group has 3 or more carbon atoms, it may contain a monovalent or divalent heterocyclic ring or may form a ring. The hydrocarbon surfactants include R 7Z (-LM)3(wherein, R 7Z is a monovalent organic group containing one or more carbon atoms. L is -ArSO3 - , -SO3 - , -SO4-, -PO3 - or -COO - and M is H, a metal atom, or NR 5Z 4. An imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, R 5Z is H or an organic group. -ArSO3 - is an aryl sulfonate. ) R 7ZR may be a linear or branched alkylidyne group having 1 or more carbon atoms which may have a substituent, or a cyclic alkylidyne group having 3 or more carbon atoms which may have a substituent. 7Z When the alkylidyne group has 3 or more carbon atoms, it may contain a monovalent or divalent heterocycle or may form a ring. Above R 5z is preferably H or an alkyl group, more preferably H or an alkyl group having 1 to 10 carbon atoms, and even more preferably H or an alkyl group having 1 to 4 carbon atoms. In this disclosure, unless otherwise specified, the term "substituent" refers to a substitutable group. Examples of the "substituent" include an aliphatic group, an aromatic group, a heterocyclic group, an acyl group, an acyloxy group, an acylamino group, an aliphatic oxy group, an aromatic oxy group, a heterocyclic oxy group, an aliphatic oxycarbonyl group, an aromatic oxycarbonyl group, a heterocyclic oxycarbonyl group, a carbamoyl group, an aliphatic sulfonyl group, an aromatic sulfonyl group, a heterocyclic sulfonyl group, an aliphatic sulfonyloxy group, an aromatic sulfonyloxy group, a heterocyclic sulfonyloxy group, a sulfamoyl group, an aliphatic sulfonamido group, an aromatic sulfonamido group, a heterocyclic sulfonamido group, an amino group, an aliphatic amino group, an and hydroxy groups, cyano groups, sulfo groups, carboxy groups, aliphatic oxyamino groups, aromatic oxyamino groups, carbamoylamino groups, sulfamoylamino groups, halogen atoms, sulfamoylcarbamoyl groups, carbamoylsulfamoyl groups, dialiphatic oxyphosphinyl groups, and diaromatic oxyphosphinyl groups.

[0077] The hydrocarbon surfactant also includes a siloxane hydrocarbon surfactant, which is also disclosed in U.S. Patent No. 6,841,616.

[0078] Anionic hydrocarbon surfactants also include the sulfosuccinate surfactant Lankropol® K8300 from Akzo Nobel Surface Chemistry LLC. Sulfosuccinate surfactants include sodium diisodecyl sulfosuccinate (Emulsogen® SB10 from Clariant), sodium diisotridecyl sulfosuccinate (Polirol® TR / LNA from Cesapinia Chemicals), and the like.

[0079] The hydrocarbon surfactant may be PolyFox (registered trademark) surfactant from Omnova Solutions, Inc. TM PF-156A, PolyFox TM PF-136A, etc.)

[0080] The hydrocarbon surfactant is preferably an anionic hydrocarbon surfactant. The anionic hydrocarbon surfactants described above can be used, but for example, the following anionic hydrocarbon surfactants can be suitably used.

[0081] The hydrocarbon surfactant may be a surfactant represented by the general formula (1): [ka] (In the formula, R 1 ~R 5 represents H or a monovalent substituent, provided that R 1 and R 3 At least one of the groups has the general formula: -YR 6 a group represented by R 2 and R 5 At least one of the groups is a group represented by the general formula: -XA or a group represented by the general formula: -YR 6 represents a group represented by the following formula: Furthermore, X, in each occurrence, is the same or different and represents a divalent linking group or a bond; A is the same or different in each occurrence and is -COOM, -SO3M, or -OSO3M (M is H, a metal atom, NR 7 4. An imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, R 7 is H or an organic group); Y may be the same or different in each occurrence and may be -S(=O)2-, -O-, -COO-, -OCO-, -CONR 8 - and -NR 8 a divalent linking group selected from the group consisting of CO—, or a bond, R 8 is H or an organic group; R 6 are the same or different in each occurrence and each represents an alkyl group having one or more carbon atoms which may contain at least one group selected from the group consisting of a carbonyl group, an ester group, an amide group and a sulfonyl group between carbon atoms; Represents. R 1 ~R 5 Any two of these may be bonded to each other to form a ring.) (hereinafter also referred to as surfactant (1)) is a preferred example.

[0082] The surfactant (1) will be explained.

[0083] In the formula, R 1 ~R 5 represents H or a monovalent substituent, provided that R 1 and R 3 At least one of the groups has the general formula: -YR 6 a group represented by R 2 and R 5 At least one of the groups is a group represented by the general formula: -XA or a group represented by the general formula: -YR 6 R represents a group represented by 1 ~R 5 Any two of these may be bonded to each other to form a ring.

[0084] R 1The substituent that the alkyl group may have is preferably a halogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, or a hydroxy group, and more preferably a methyl group or an ethyl group.

[0085] R 1 The alkyl group as above preferably does not contain a carbonyl group. The alkyl group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms or chlorine atoms. The alkyl group preferably does not have any substituents.

[0086] R 1 As the alkyl group, a linear or branched alkyl group having 1 to 10 carbon atoms which may have a substituent or a cyclic alkyl group having 3 to 10 carbon atoms which may have a substituent is preferred, a linear or branched alkyl group having 1 to 10 carbon atoms which does not contain a carbonyl group or a cyclic alkyl group having 3 to 10 carbon atoms which does not contain a carbonyl group is more preferred, a linear or branched alkyl group having 1 to 10 carbon atoms which does not contain a substituent is even more preferred, a linear or branched alkyl group having 1 to 3 carbon atoms which does not contain a substituent is even more preferred, a methyl group (-CH3) or an ethyl group (-C2H5) is particularly preferred, and a methyl group (-CH3) is most preferred.

[0087] The monovalent substituent includes a group represented by the general formula: -YR 6 a group represented by the general formula: -XA; -H; optionally substituted C 1-20 Alkyl groups, -NH2, -NHR 9 (R 9 is an organic group), -OH, -COOR 9 (R 9 is an organic group) or -OR 9 (R 9is an organic group). The alkyl group preferably has 1 to 10 carbon atoms.

[0088] R 9 As for C 1-10 or C 1-10 The alkylcarbonyl group of C is preferred. 1-4 or C 1-4 An alkylcarbonyl group of the formula is more preferred.

[0089] In the formula, X may be the same or different in each occurrence and represents a divalent linking group or bond. R 6 When X does not contain any of a carbonyl group, an ester group, an amide group, and a sulfonyl group, X is preferably a divalent linking group containing at least one group selected from the group consisting of a carbonyl group, an ester group, an amide group, and a sulfonyl group.

[0090] X may be -CO-, -S(=O)2-, -O-, -COO-, -OCO-, -S(=O)2-O-, -OS(=O)2-, or -CONR 8 - and -NR 8 a divalent linking group containing at least one bond selected from the group consisting of CO—, C 1-10 An alkylene group or a bond represented by the formula R 8 represents H or an organic group.

[0091] R 8 The organic group in R is preferably an alkyl group. 8 As for H or C 1-10 is preferably an organic group represented by the formula: 1-4 The organic group is more preferably H or C 1-4 More preferred is an alkyl group of the formula (I), and even more preferred is H.

[0092] In the formula, A is the same or different in each occurrence and is -COOM, -SO3M, or -OSO3M (M is H, a metal atom, NR 7 4. An imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, R7 is H or an organic group. 7 may be the same or different. In general formula (1), A is one of the preferred embodiments -COOM.

[0093] R 7 The organic group in R is preferably an alkyl group. 7 As for H or C 1-10 is preferably an organic group represented by the formula: 1-4 The organic group is more preferably H or C 1-4 More preferred are alkyl groups of the formula: The metal atom includes alkali metals (Group 1) and alkaline earth metals (Group 2), and is preferably Na, K or Li.

[0094] M is H, a metal atom, or NR 7 4 is preferred, H, an alkali metal (Group 1), an alkaline earth metal (Group 2) or NR 7 4 is more preferred, H, Na, K, Li or NH4 is even more preferred, Na, K or NH4 is even more preferred, Na or NH4 is particularly preferred, and NH4 is most preferred.

[0095] In the formula, Y may be the same or different in each occurrence and may be -S(=O)2-, -O-, -COO-, -OCO-, -CONR 8 - and -NR 8 a divalent linking group selected from the group consisting of CO—, or a bond, R 8 represents H or an organic group.

[0096] Y is a bond, -O-, -COO-, -OCO-, -CONR 8 - and -NR 8 A divalent linking group selected from the group consisting of -CO- is preferred, and a divalent linking group selected from the group consisting of a bond, -COO-, and -OCO- is more preferred.

[0097] R 8 The organic group in R is preferably an alkyl group. 8 As for H or C 1-10is preferably an organic group represented by the formula: 1-4 The organic group is more preferably H or C 1-4 More preferred is an alkyl group of the formula (I), and even more preferred is H.

[0098] In the formula, R 6 In each occurrence, R may be the same or different and represent an alkyl group having one or more carbon atoms which may contain at least one group selected from the group consisting of a carbonyl group, an ester group, an amide group and a sulfonyl group between carbon atoms. 6 The organic group preferably has 2 or more carbon atoms and 20 or less carbon atoms, more preferably 2 to 20 carbon atoms, and even more preferably 2 to 10 carbon atoms.

[0099] R 6 When the alkyl group of R has two or more carbon atoms, it may contain one or more groups selected from the group consisting of a carbonyl group, an ester group, an amide group, and a sulfonyl group between carbon atoms, but does not contain these groups at both ends of the alkyl group. 6 The alkyl group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to the carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms or chlorine atoms.

[0100] R 6 As for General formula:-R 10 -CO-R 11 a group represented by General formula:-R 10 -COO-R 11 a group represented by General formula:-R 11 a group represented by General formula:-R 10 -NR 8 CO-R 11 or a group represented by General formula:-R 10 -CONR 8 -R 11 a group represented by (In the formula, R 8 represents H or an organic group. 10 is an alkylene group, R 11 is preferably an alkyl group which may have a substituent. R 6 As the general formula: -R 10 -CO-R 11 A group represented by the following formula is more preferred.

[0101] R 8 The organic group in R is preferably an alkyl group. 8 As for H or C 1-10 is preferably an organic group represented by the formula: 1-4 The organic group is more preferably H or C 1-4 More preferred is an alkyl group of the formula (I), and even more preferred is H.

[0102] R 10 The number of carbon atoms in the alkylene group of R is preferably 1 or more, more preferably 3 or more, and is preferably 20 or less, more preferably 12 or less, even more preferably 10 or less, and particularly preferably 8 or less. 10 The alkylene group preferably has 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, and even more preferably 3 to 10 carbon atoms.

[0103] R 11 The number of carbon atoms in the alkyl group may be 1 to 20, preferably 1 to 15, more preferably 1 to 12, even more preferably 1 to 10, even more preferably 1 to 8, particularly preferably 1 to 6, even more preferably 1 to 3, particularly preferably 1 or 2, and most preferably 1. 11 The alkyl group of R is preferably composed of only primary, secondary, and tertiary carbon atoms, and particularly preferably composed of only primary and secondary carbon atoms. 11 As the alkyl group, a methyl group, an ethyl group, an n-propyl group, or an isopropyl group is preferred, and a methyl group is most preferred.

[0104] In general formula (1), R 2 and R 5In one preferred embodiment, at least one of the above is a group represented by the general formula: -XA, where A is -COOM.

[0105] The hydrocarbon surfactant may be a surfactant represented by the following formula (1-0A): [ka] (In the formula, R 1A ~R 5A represents H, a monovalent hydrocarbon group which may contain an ester group between carbon atoms, or a group represented by the general formula: -X A -A, where R 2A and R 5A At least one of the groups has the general formula: -X A - represents a group represented by A. X A is, in each occurrence, the same or different, a divalent hydrocarbon radical or a bond; A is the same or different in each occurrence and is -COOM (M is H, a metal atom, NR 7 4. An imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, R 7 is H or an organic group); R 1A ~R 5A Any two of these may be bonded to each other to form a ring.

[0106] In general formula (1-0A), R 1A ~R 5A In R, the monovalent hydrocarbon group which may contain an ester group between carbon atoms preferably has 1 to 50 carbon atoms, more preferably 5 to 20 carbon atoms. 1A ~R 5A Any two of these may be bonded to each other to form a ring. The monovalent hydrocarbon group which may contain an ester group between carbon atoms is preferably an alkyl group. In the formula, X AIn the formula, the number of carbon atoms in the divalent hydrocarbon group is preferably 1 to 50, and more preferably 5 to 20. Examples of the divalent hydrocarbon group include an alkylene group and an alkanediyl group, with an alkylene group being preferred.

[0107] In general formula (1-0A), R 2A and R 5A any one of the above general formula: -X A -A is preferred, and R 2A is represented by the above general formula: -X A A group represented by -A is more preferred.

[0108] In the general formula (1-0A), a preferred embodiment is R 2A is represented by the general formula: -X A -A, and R 1A , R 3A , R 4A and R 5A is H. In this case, X A is preferably a bond or an alkylene group having 1 to 5 carbon atoms.

[0109] In the general formula (1-0A), a preferred embodiment is also R 2A is represented by the general formula: -X A -A, and R 1A and R 3A Ga-Y A -R 6 and Y A is the same or different in each occurrence and is -COO-, -OCO-, or a bond; R 6 In this embodiment, R is the same or different in each occurrence and is an alkyl group having 1 or more carbon atoms. 4A and R 5A is preferably H.

[0110] Examples of hydrocarbon surfactants represented by general formula (1-0A) include glutaric acid or a salt thereof, adipic acid or a salt thereof, pimelic acid or a salt thereof, suberic acid or a salt thereof, azelaic acid or a salt thereof, and sebacic acid or a salt thereof. Furthermore, the aliphatic carboxylic acid hydrocarbon surfactant represented by general formula (1-0A) may be a two-chain two-hydrophilic group synthetic surfactant, and examples of such Gemini surfactants include Geminisurf (Chukyo Yushi Co., Ltd.), Gemsurf α142 (12 carbon atoms, lauryl group), Gemsurf α102 (10 carbon atoms), and Gemsurf α182 (14 carbon atoms).

[0111] The hydrocarbon surfactant also includes a hydrocarbon surfactant having one or more carbonyl groups (excluding carbonyl groups in carboxyl groups). Furthermore, hydrocarbon surfactants obtained by subjecting the above hydrocarbon surfactants having one or more carbonyl groups (excluding carbonyl groups in carboxyl groups) to radical treatment or oxidation treatment can also be used. The radical treatment may be any treatment that generates radicals in a hydrocarbon surfactant having one or more carbonyl groups (excluding carbonyl groups in carboxyl groups). For example, deionized water and a hydrocarbon surfactant are added to a reactor, the reactor is sealed, the system is purged with nitrogen, the reactor is heated and pressurized, a polymerization initiator is added, the mixture is stirred for a certain period of time, the reactor is depressurized to atmospheric pressure, and then cooled. The oxidation treatment is a treatment in which an oxidizing agent is added to a hydrocarbon surfactant having one or more carbonyl groups (excluding carbonyl groups in carboxyl groups). Examples of oxidizing agents include oxygen, ozone, hydrogen peroxide, manganese(IV) oxide, potassium permanganate, potassium dichromate, nitric acid, and sulfur dioxide. To accelerate the radical treatment or oxidation treatment, the radical treatment or oxidation treatment may be carried out in an aqueous solution with an adjusted pH. The pH of the aqueous solution used for the radical treatment or oxidation treatment is preferably less than 7, and the pH of the aqueous solution can be adjusted using sulfuric acid, nitric acid, hydrochloric acid, or the like.

[0112] The hydrocarbon surfactant having one or more carbonyl groups (excluding carbonyl groups in carboxyl groups) is preferably a surfactant represented by the formula: R X -X X (In the formula, RX is a fluorine-free organic group having 1 to 2000 carbon atoms and one or more carbonyl groups (excluding carbonyl groups in carboxyl groups), and X X -OSO3X X1 , -COOX X1 or -SO3X X1 (X X1 is H, metal atom, NR X1 4. An optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, wherein R X1 R is H or an organic group and may be the same or different. Surfactants represented by the formula: X R preferably has 500 or less carbon atoms, more preferably 100 or less, even more preferably 50 or less, and even more preferably 30 or less. X1 The organic group in R is preferably an alkyl group. X1 is preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms, and even more preferably H or an alkyl group having 1 to 4 carbon atoms. The hydrocarbon surfactant may be a surfactant represented by the following formula (a): [ka] (In the formula, R 1a R is a linear or branched alkyl group having 1 or more carbon atoms or a cyclic alkyl group having 3 or more carbon atoms, in which a hydrogen atom bonded to a carbon atom may be substituted with a monovalent organic group containing a hydroxy group or an ester bond, and when it has 2 or more carbon atoms, it may contain a carbonyl group, and when it has 3 or more carbon atoms, it may contain a monovalent or divalent heterocycle or form a ring. 2a and R 3a R is independently a single bond or a divalent linking group. 1a , R 2a and R 3a X has a total of 6 or more carbon atoms. a is H, metal atom, NR 4a4. An optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, wherein R 4a are H or organic groups, and may be the same or different. 1a , R 2a and R 3a Any two of these may be bonded to each other to form a ring.) A surfactant (a) represented by the following formula (b): [ka] (In the formula, R 1b R is a linear or branched alkyl group having 1 or more carbon atoms which may have a substituent, or a cyclic alkyl group having 3 or more carbon atoms which may have a substituent, and when the alkyl group has 3 or more carbon atoms, it may contain a monovalent or divalent heterocycle or form a ring. 2b and R 4b are independently H or a substituent. 3b is an alkylene group having 1 to 10 carbon atoms which may have a substituent. n is an integer of 1 or more. p and q are independently integers of 0 or more. X b is H, metal atom, NR 5b 4. An optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, wherein R 5b are H or organic groups, and may be the same or different. 1b , R 2b , R 3b and R 4b Any two of may be bonded to each other to form a ring. L is a single bond, -CO2-B-*, -OCO-B-*, -CONR 6b -B-*, -NR 6b CO-B-* or -CO- (However, -CO2-B-, -OCO-B-, -CONR 6b -B-, -NR 6 The carbonyl group contained in CO-B- is excluded.) B is a single bond or an alkylene group having 1 to 10 carbon atoms which may have a substituent, and R 6b represents H or an alkyl group having 1 to 4 carbon atoms which may have a substituent. * represents -OSO3X in the formula.b (b) a surfactant represented by the following formula (c): [ka] (In the formula, R 1c R is a linear or branched alkyl group having 1 or more carbon atoms or a cyclic alkyl group having 3 or more carbon atoms, in which a hydrogen atom bonded to a carbon atom may be substituted with a monovalent organic group containing a hydroxy group or an ester bond, and when it has 2 or more carbon atoms, it may contain a carbonyl group, and when it has 3 or more carbon atoms, it may contain a monovalent or divalent heterocycle or form a ring. 2c and R 3c R is independently a single bond or a divalent linking group. 1c , R 2c and R 3c A has a total of 5 or more carbon atoms. c -COOX c or -SO3X c (X c is H, metal atom, NR 4c 4. An optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, wherein R 4c are H or organic groups, and may be the same or different. 1c , R 2c and R 3c Any two of these may be bonded to each other to form a ring.) and a surfactant (c) represented by the following formula (d): [ka] (In the formula, R 1d R is a linear or branched alkyl group having 1 or more carbon atoms which may have a substituent, or a cyclic alkyl group having 3 or more carbon atoms which may have a substituent, and when the alkyl group has 3 or more carbon atoms, it may contain a monovalent or divalent heterocycle or form a ring. 2d and R 4d are independently H or a substituent. 3dis an alkylene group having 1 to 10 carbon atoms which may have a substituent. n is an integer of 1 or more. p and q are independently integers of 0 or more. A d -SO3X d or -COOX d (X d is H, metal atom, NR 5d 4. An optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, wherein R 5d are H or organic groups, and may be the same or different. 1d , R 2d , R 3d and R 4d Any two of may be bonded to each other to form a ring. L is a single bond, -CO2-B-*, -OCO-B-*, -CONR 6d -B-*, -NR 6d CO-B-* or -CO- (However, -CO2-B-, -OCO-B-, -CONR 6d -B-, -NR 6d The carbonyl group contained in CO-B- is excluded.) B is a single bond or an alkylene group having 1 to 10 carbon atoms which may have a substituent, and R 6d is H or an alkyl group having 1 to 4 carbon atoms which may have a substituent. * represents A in the formula. d It is more preferable that the surfactant (d) is at least one selected from the group consisting of surfactants (d) represented by the formula:

[0113] The surfactant (a) will now be described.

[0114] In formula (a), R 1a is a linear or branched alkyl group having 1 or more carbon atoms or a cyclic alkyl group having 3 or more carbon atoms. When the alkyl group has three or more carbon atoms, it may contain a carbonyl group (-C(=O)-) between two carbon atoms. When the alkyl group has two or more carbon atoms, it may also contain the carbonyl group at the terminal of the alkyl group. In other words, acyl groups such as an acetyl group represented by CH3-C(=O)- are also included in the alkyl group. Furthermore, when the alkyl group has 3 or more carbon atoms, it may contain a monovalent or divalent heterocyclic ring or may form a ring. The heterocyclic ring is preferably an unsaturated heterocyclic ring, more preferably an oxygen-containing unsaturated heterocyclic ring, such as a furan ring. 1a In the above, a divalent heterocycle may be inserted between two carbon atoms, a divalent heterocycle may be located at a terminal and bonded to -C(=O)-, or a monovalent heterocycle may be located at the terminal of the alkyl group.

[0115] In the present disclosure, the "number of carbon atoms" of the alkyl group includes the number of carbon atoms constituting the carbonyl group and the number of carbon atoms constituting the heterocycle. For example, a group represented by CH3-C(=O)-CH2- has 3 carbon atoms, a group represented by CH3-C(=O)-C2H4-C(=O)-C2H4- has 7 carbon atoms, and a group represented by CH3-C(=O)- has 2 carbon atoms.

[0116] In the alkyl group, a hydrogen atom bonded to a carbon atom may be substituted with a functional group, for example, with a hydroxy group (—OH) or a monovalent organic group containing an ester bond, but it is preferable that the alkyl group is not substituted with any functional group. The monovalent organic group containing an ester bond is a group represented by the formula: -OC(=O)-R 101a (In the formula, R 101a is an alkyl group). The alkyl group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms or chlorine atoms.

[0117] In the formula, R 2a and R 3a are independently a single bond or a divalent linking group. R 2a and R 3aare preferably independently a single bond, a linear or branched alkylene group having 1 or more carbon atoms, or a cyclic alkylene group having 3 or more carbon atoms. R 2a and R 3a The alkylene group constituting the formula (I) preferably does not contain a carbonyl group.

[0118] In the alkylene group, a hydrogen atom bonded to a carbon atom may be substituted with a functional group, for example, with a hydroxy group (—OH) or a monovalent organic group containing an ester bond, but it is preferable that the alkylene group is not substituted with any functional group. The monovalent organic group containing an ester bond is a group represented by the formula: -OC(=O)-R 102a (In the formula, R 102a is an alkyl group). The alkylene group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkylene group that does not contain halogen atoms such as fluorine atoms or chlorine atoms.

[0119] R 1a , R 2a and R 3a has a total carbon number of 6 or more. The total carbon number is preferably 8 or more, more preferably 9 or more, and even more preferably 10 or more, and is preferably 20 or less, more preferably 18 or less, and even more preferably 15 or less. R 1a , R 2a and R 3a Any two of these may be bonded to each other to form a ring.

[0120] In formula (a), X a is H, metal atom, NR 4a 4. An optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, wherein R 4a is H or an organic group.4a may be the same or different. 4a The organic group in R is preferably an alkyl group. 4a is preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms, and even more preferably H or an alkyl group having 1 to 4 carbon atoms. Examples of the metal atom include monovalent and divalent metal atoms, such as alkali metals (Group 1) and alkaline earth metals (Group 2), and Na, K, or Li is preferred. X a H, alkali metals (group 1), alkaline earth metals (group 2) or NR 4a X is preferred, H, Na, K, Li or NH is more preferred because they are easily soluble in water, Na, K or NH is even more preferred because they are even more easily soluble in water, Na or NH is particularly preferred, and NH is most preferred because it is easily removed. a When is NH4, the surfactant has excellent solubility in an aqueous medium, and metal components are less likely to remain in the polymer or the final product.

[0121] Examples of surfactant (a) include the following surfactants: a is as described above.

[0122] [ka]

[0123] [ka]

[0124] [ka]

[0125] [ka]

[0126] [ka]

[0127] [ka]

[0128] [ka]

[0129] [ka]

[0130] Next, the surfactant (b) will be described.

[0131] In formula (b), R 1b is a linear or branched alkyl group having 1 or more carbon atoms which may have a substituent, or a cyclic alkyl group having 3 or more carbon atoms which may have a substituent. When the alkyl group has 3 or more carbon atoms, it may contain a monovalent or divalent heterocyclic ring or may form a ring. The heterocyclic ring is preferably an unsaturated heterocyclic ring, more preferably an oxygen-containing unsaturated heterocyclic ring, such as a furan ring. 1b In the above, a divalent heterocycle may be inserted between two carbon atoms, a divalent heterocycle may be located at a terminal and bonded to -C(=O)-, or a monovalent heterocycle may be located at the terminal of the alkyl group.

[0132] In the present disclosure, the "number of carbon atoms" of the alkyl group includes the number of carbon atoms constituting the heterocycle.

[0133] R 1b The substituent that the alkyl group may have is preferably a halogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, or a hydroxy group, and more preferably a methyl group or an ethyl group.

[0134] R 1b The alkyl group as above preferably does not contain a carbonyl group. The alkyl group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms or chlorine atoms. The alkyl group preferably does not have any substituents.

[0135] R 1b As the alkyl group, a linear or branched alkyl group having 1 to 10 carbon atoms which may have a substituent or a cyclic alkyl group having 3 to 10 carbon atoms which may have a substituent is preferred, a linear or branched alkyl group having 1 to 10 carbon atoms which does not contain a carbonyl group or a cyclic alkyl group having 3 to 10 carbon atoms which does not contain a carbonyl group is more preferred, a linear or branched alkyl group having 1 to 10 carbon atoms which does not contain a substituent is even more preferred, a linear or branched alkyl group having 1 to 3 carbon atoms which does not contain a substituent is even more preferred, a methyl group (-CH3) or an ethyl group (-C2H5) is particularly preferred, and a methyl group (-CH3) is most preferred.

[0136] In formula (b), R 2b and R 4b are independently H or a substituent. 2b and R 4b may be the same or different.

[0137] R 2b and R 4b The substituent as is preferably a halogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, or a hydroxy group, and particularly preferably a methyl group or an ethyl group.

[0138] R 2b and R 4bThe alkyl group as the alkyl group preferably does not contain a carbonyl group. The alkyl group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms or chlorine atoms. The alkyl group preferably does not have any substituents.

[0139] R 2b and R 4b The alkyl group as the alkyl group is preferably a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group, or a cyclic alkyl group having 3 to 10 carbon atoms and not containing a carbonyl group, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group, even more preferably a linear or branched alkyl group having 1 to 3 carbon atoms and not containing a substituent, and particularly preferably a methyl group (-CH3) or an ethyl group (-C2H5).

[0140] R 2b and R 4b are each independently preferably H or a straight-chain or branched-chain alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group, more preferably H or a straight-chain or branched-chain alkyl group having 1 to 3 carbon atoms and not containing a substituent, even more preferably H, a methyl group (-CH3) or an ethyl group (-C2H5), and particularly preferably H.

[0141] In formula (b), R 3b R is an alkylene group having 1 to 10 carbon atoms which may have a substituent. 3b When there are a plurality of, they may be the same or different.

[0142] The alkylene group preferably does not contain a carbonyl group. The alkylene group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms or chlorine atoms. The alkylene group preferably does not have any substituents.

[0143] The alkylene group is preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may have a substituent, or a cyclic alkylene group having 3 to 10 carbon atoms which may have a substituent, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms which does not contain a carbonyl group, or a cyclic alkylene group having 3 to 10 carbon atoms which does not contain a carbonyl group, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms which does not have a substituent, and still more preferably a methylene group (-CH2-), an ethylene group (-C2H4-), an isopropylene group (-CH(CH3)CH2-) or a propylene group (-C3H6-).

[0144] R 1b , R 2b , R 3b and R 4b Any two of may be bonded to each other to form a ring, but it is preferable that they do not form a ring.

[0145] In formula (b), n is an integer of 1 or greater. n is preferably an integer of 1 to 40, more preferably an integer of 1 to 30, still more preferably an integer of 5 to 25, and particularly preferably an integer of 5 to 9 or 11 to 25.

[0146] In formula (b), p and q are independently an integer of 0 or greater. p is preferably an integer of 0 to 10, more preferably 0 or 1. q is preferably an integer of 0 to 10, more preferably an integer of 0 to 5.

[0147] The sum of n, p, and q is preferably an integer of 5 or greater. The sum of n, p, and q is more preferably an integer of 8 or greater. The sum of n, p, and q is also preferably an integer of 60 or less, more preferably an integer of 50 or less, and even more preferably an integer of 40 or less.

[0148] In formula (b), X b is H, metal atom, NR 5b 4. An optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, wherein R 5b is H or an organic group. 5b may be the same or different. 5b The organic group in R is preferably an alkyl group. 5b is preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms, and even more preferably H or an alkyl group having 1 to 4 carbon atoms. Examples of the metal atom include monovalent and divalent metal atoms, such as alkali metals (Group 1) and alkaline earth metals (Group 2), with Na, K, or Li being preferred. X b is a metal atom or NR 5b 4(R 5b is as above). X b H, alkali metals (group 1), alkaline earth metals (group 2) or NR 5b X is preferred, H, Na, K, Li or NH is more preferred because they are easily soluble in water, Na, K or NH is even more preferred because they are even more easily soluble in water, Na or NH is particularly preferred, and NH is most preferred because it is easily removed. b When is NH4, the surfactant has excellent solubility in an aqueous medium, and metal components are less likely to remain in the polymer or the final product.

[0149] In formula (b), L represents a single bond, -CO2-B-*, -OCO-B-*, or -CONR 6b -B-*, -NR 6b CO-B-* or -CO- (However, -CO2-B-, -OCO-B-, -CONR6b -B-, -NR 6 The carbonyl group contained in CO-B- is excluded.) B is a single bond or an alkylene group having 1 to 10 carbon atoms which may have a substituent, and R 6b is H or an alkyl group having 1 to 4 carbon atoms which may have a substituent. The alkylene group more preferably has 1 to 5 carbon atoms. 6 is more preferably H or a methyl group. * represents -OSO3X in the formula. b This refers to the side that binds to the

[0150] L is preferably a single bond.

[0151] Examples of the surfactant (b) include: CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2CH2OSO3Na, CH3C(O)CH2CH2CH2CH2OSO3Na, (CH3)3CC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, (CH3)2CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, (CH2)5CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3CH2CH2C(O)CH2CH2CH2CH2CH2CH2CH2OSO3Na, CH3CH2CH2CH2C(O)CH2CH2CH2CH2CH2CH2OSO3Na, CH3CH2CH2CH2CH2C(O)CH2CH2CH2CH2CH2OSO3Naぁ CH3CH2CH2CH2CH2CH2C(O)CH2CH2CH2CH2OSO3Naぁ CH3CH2CH2CH2CH2CH2CH2C(O)CH2CH2CH2OSO3Naぁ CH3CH2CH2CH2CH2CH2CH2CH2C(O)CH2CH2OSO3Naぁ CH3CH2CH2CH2CH2CH2CH2CH2CH2C(O)CH2OSO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OCH2CH2OSO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)NHCH2OSO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2NHC(O)CH2OSO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OSO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH2OSO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OC(O)CH2OSO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3H、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Liぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3K、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3NH4、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH(CH3)2OSO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ (CH3)3CC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ (CH3)2CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ (CH2)5CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3CH2CH2CH2CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3CH2CH2CH2CH2CH2CH2CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)CH2CH2CH2CH2CH2CH2CH2OSO3Naぁ CH3CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)CH2CH2CH2CH2OSO3Naぁ CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OCH2CH2OSO3Naぁ CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)NHCH2CH2OSO3Na、 CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2NHC(O)CH2CH2OSO3Na、 CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH2CH2OSO3Na、 CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OC(O)CH2CH2OSO3Naぁ CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OSO3Na、 CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3H、 CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Liぁ CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3K、 CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3NH4、 Examples include CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2OSO3Na.

[0152] The surfactant (c) will now be explained.

[0153] In formula (c), R 1c is a linear or branched alkyl group having 1 or more carbon atoms or a cyclic alkyl group having 3 or more carbon atoms. When the alkyl group has three or more carbon atoms, it may contain a carbonyl group (-C(=O)-) between two carbon atoms. When the alkyl group has two or more carbon atoms, it may also contain the carbonyl group at the terminal of the alkyl group. In other words, acyl groups such as an acetyl group represented by CH3-C(=O)- are also included in the alkyl group. Furthermore, when the alkyl group has 3 or more carbon atoms, it may contain a monovalent or divalent heterocyclic ring or may form a ring. The heterocyclic ring is preferably an unsaturated heterocyclic ring, more preferably an oxygen-containing unsaturated heterocyclic ring, such as a furan ring. 1c In the above, a divalent heterocycle may be inserted between two carbon atoms, a divalent heterocycle may be located at a terminal and bonded to -C(=O)-, or a monovalent heterocycle may be located at the terminal of the alkyl group.

[0154] In the present disclosure, the "number of carbon atoms" of the alkyl group includes the number of carbon atoms constituting the carbonyl group and the number of carbon atoms constituting the heterocycle. For example, a group represented by CH3-C(=O)-CH2- has 3 carbon atoms, a group represented by CH3-C(=O)-C2H4-C(=O)-C2H4- has 7 carbon atoms, and a group represented by CH3-C(=O)- has 2 carbon atoms.

[0155] In the alkyl group, a hydrogen atom bonded to a carbon atom may be substituted with a functional group, for example, with a hydroxy group (—OH) or a monovalent organic group containing an ester bond, but it is preferable that the alkyl group is not substituted with any functional group. The monovalent organic group containing an ester bond is a group represented by the formula: -OC(=O)-R 101c (In the formula, R 101c is an alkyl group). The alkyl group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms or chlorine atoms.

[0156] In formula (c), R 2c and R 3c are independently a single bond or a divalent linking group. R 2c and R 3c are preferably independently a single bond, a linear or branched alkylene group having 1 or more carbon atoms, or a cyclic alkylene group having 3 or more carbon atoms. R 2c and R 3c The alkylene group constituting the formula (I) preferably does not contain a carbonyl group.

[0157] In the alkylene group, a hydrogen atom bonded to a carbon atom may be substituted with a functional group, for example, with a hydroxy group (—OH) or a monovalent organic group containing an ester bond, but it is preferable that the alkylene group is not substituted with any functional group. The monovalent organic group containing an ester bond is a group represented by the formula: -OC(=O)-R 102c (In the formula, R 102c is an alkyl group). The alkylene group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkylene group that does not contain halogen atoms such as fluorine atoms or chlorine atoms.

[0158] R 1c , R 2c and R 3c has a total carbon number of 5 or more. The total carbon number is preferably 7 or more, more preferably 9 or more, and is preferably 20 or less, more preferably 18 or less, and even more preferably 15 or less. R 1c , R 2c and R 3c Any two of these may be bonded to each other to form a ring.

[0159] In formula (c), in formula, A c -COOX c or -SO3X c (X c is H, metal atom, NR 4c 4. An optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, wherein R 4c are H or organic groups, and may be the same or different. 4c The organic group in R is preferably an alkyl group. 4c is preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms, and even more preferably H or an alkyl group having 1 to 4 carbon atoms. The metal atom includes monovalent and divalent metal atoms, such as alkali metals (Group 1) and alkaline earth metals (Group 2), and is preferably Na, K, or Li. X c H, alkali metals (group 1), alkaline earth metals (group 2) or NR 4cX is preferred, H, Na, K, Li or NH is more preferred because they are easily soluble in water, Na, K or NH is even more preferred because they are even more easily soluble in water, Na or NH is particularly preferred, and NH is most preferred because it is easily removed. c When is NH4, the surfactant has excellent solubility in an aqueous medium, and metal components are less likely to remain in the polymer or the final product.

[0160] Examples of the surfactant (c) include the following surfactants: c is as described above.

[0161] [ka]

[0162] [ka]

[0163] [ka]

[0164] [ka]

[0165] [ka]

[0166] [ka]

[0167] [ka]

[0168] [ka]

[0169] The surfactant (d) will now be described.

[0170] In formula (d), R 1d is a linear or branched alkyl group having 1 or more carbon atoms which may have a substituent, or a cyclic alkyl group having 3 or more carbon atoms which may have a substituent. When the alkyl group has 3 or more carbon atoms, it may contain a monovalent or divalent heterocyclic ring or may form a ring. The heterocyclic ring is preferably an unsaturated heterocyclic ring, more preferably an oxygen-containing unsaturated heterocyclic ring, such as a furan ring. 1d In the above, a divalent heterocycle may be inserted between two carbon atoms, a divalent heterocycle may be located at a terminal and bonded to -C(=O)-, or a monovalent heterocycle may be located at the terminal of the alkyl group.

[0171] In the present disclosure, the "number of carbon atoms" of the alkyl group includes the number of carbon atoms constituting the heterocycle.

[0172] R 1d The substituent that the alkyl group may have is preferably a halogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, or a hydroxy group, and more preferably a methyl group or an ethyl group.

[0173] R 1d The alkyl group as above preferably does not contain a carbonyl group. The alkyl group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms or chlorine atoms. The alkyl group preferably does not have any substituents.

[0174] R 1d As the alkyl group, a linear or branched alkyl group having 1 to 10 carbon atoms which may have a substituent or a cyclic alkyl group having 3 to 10 carbon atoms which may have a substituent is preferred, a linear or branched alkyl group having 1 to 10 carbon atoms which does not contain a carbonyl group or a cyclic alkyl group having 3 to 10 carbon atoms which does not contain a carbonyl group is more preferred, a linear or branched alkyl group having 1 to 10 carbon atoms which does not contain a substituent is even more preferred, a linear or branched alkyl group having 1 to 3 carbon atoms which does not contain a substituent is even more preferred, a methyl group (-CH3) or an ethyl group (-C2H5) is particularly preferred, and a methyl group (-CH3) is most preferred.

[0175] In formula (d), R 2d and R 4d are independently H or a substituent. 2d and R 4d may be the same or different.

[0176] R 2d and R 4d The substituent as is preferably a halogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, or a hydroxy group, and particularly preferably a methyl group or an ethyl group.

[0177] R 2d and R 4d The alkyl group as the alkyl group preferably does not contain a carbonyl group. The alkyl group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms or chlorine atoms. The alkyl group preferably does not have any substituents.

[0178] R 2d and R 4dThe alkyl group as the alkyl group is preferably a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group, or a cyclic alkyl group having 3 to 10 carbon atoms and not containing a carbonyl group, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group, even more preferably a linear or branched alkyl group having 1 to 3 carbon atoms and not containing a substituent, and particularly preferably a methyl group (-CH3) or an ethyl group (-C2H5).

[0179] R 2d and R 4d are each independently preferably H or a straight-chain or branched-chain alkyl group having 1 to 10 carbon atoms and not containing a carbonyl group, more preferably H or a straight-chain or branched-chain alkyl group having 1 to 3 carbon atoms and not containing a substituent, even more preferably H, a methyl group (-CH3) or an ethyl group (-C2H5), and particularly preferably H.

[0180] In formula (d), R 3d R is an alkylene group having 1 to 10 carbon atoms which may have a substituent. 3d When there are a plurality of, they may be the same or different.

[0181] The alkylene group preferably does not contain a carbonyl group. The alkylene group may have 75% or less, 50% or less, or 25% or less of the hydrogen atoms bonded to carbon atoms substituted with halogen atoms, but is preferably a non-halogenated alkyl group that does not contain halogen atoms such as fluorine atoms or chlorine atoms. The alkylene group preferably does not have any substituents.

[0182] The alkylene group is preferably a linear or branched alkylene group having 1 to 10 carbon atoms which may have a substituent, or a cyclic alkylene group having 3 to 10 carbon atoms which may have a substituent, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms which does not contain a carbonyl group, or a cyclic alkylene group having 3 to 10 carbon atoms which does not contain a carbonyl group, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms which does not have a substituent, and still more preferably a methylene group (-CH2-), an ethylene group (-C2H4-), an isopropylene group (-CH(CH3)CH2-) or a propylene group (-C3H6-).

[0183] R 1d , R 2d , R 3d and R 4d Any two of these may be bonded to each other to form a ring.

[0184] In formula (d), n is an integer of 1 or greater. n is preferably an integer of 1 to 40, more preferably an integer of 1 to 30, and even more preferably an integer of 5 to 25.

[0185] In formula (d), p and q are independently an integer of 0 or greater. p is preferably an integer of 0 to 10, more preferably 0 or 1. q is preferably an integer of 0 to 10, more preferably an integer of 0 to 5.

[0186] The sum of n, p, and q is preferably an integer of 6 or greater. The sum of n, p, and q is more preferably an integer of 8 or greater. The sum of n, p, and q is also preferably an integer of 60 or less, more preferably an integer of 50 or less, and even more preferably an integer of 40 or less.

[0187] In formula (d), A d -SO3X d or -COOX d (X d is H, metal atom, NR 5d4. An optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, wherein R 5d are H or organic groups, and may be the same or different. 5d The organic group in R is preferably an alkyl group. 5d is preferably H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms, and even more preferably H or an alkyl group having 1 to 4 carbon atoms. Examples of the metal atom include monovalent and divalent metal atoms, such as alkali metals (Group 1) and alkaline earth metals (Group 2), with Na, K, or Li being preferred. X d is a metal atom or NR 5d 4(R 5d is as above). X d H, alkali metals (group 1), alkaline earth metals (group 2) or NR 5d X is preferred, H, Na, K, Li or NH is more preferred because they are easily soluble in water, Na, K or NH is even more preferred because they are even more easily soluble in water, Na or NH is particularly preferred, and NH is most preferred because it is easily removed. d When is NH4, the surfactant has excellent solubility in an aqueous medium, and metal components are less likely to remain in the polymer or the final product.

[0188] In formula (d), L is a single bond, -CO2-B-*, -OCO-B-*, or -CONR 6d -B-*, -NR 6d CO-B-* or -CO- (However, -CO2-B-, -OCO-B-, -CONR 6d -B-, -NR 6d The carbonyl group contained in CO-B- is excluded.) B is a single bond or an alkylene group having 1 to 10 carbon atoms which may have a substituent, and R 6d is H or an alkyl group having 1 to 4 carbon atoms which may have a substituent. The alkylene group more preferably has 1 to 5 carbon atoms. 6d is more preferably H or a methyl group.d Refers to the side that binds to

[0189] L is preferably a single bond.

[0190] Examples of the surfactant (d) include CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2COOK, CH3C(O)CH2CH2CH2CH2CH2CH2CH2COONa, CH3C(O)CH2CH2CH2CH2CH2CH2COONa, CH3C(O)CH2CH2CH2CH2CH2COONa, CH3C(O)CH2CH2CH2CH2COONa, CH3C(O)CH2CH2CH2COONa, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2COONa, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2COONa, (CH3)3CC(O)CH2CH2CH2CH2CH2CH2CH2CH2COONa, (CH3)2CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2COONa, (CH2)5CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2COONa, CH3CH2C(O)CH2CH2CH2CH2CH2CH2CH2COONa, CH3CH2CH2C(O)CH2CH2CH2CH2CH2CH2COONa, CH3CH2CH2CH2C(O)CH2CH2CH2CH2CH2COONa, CH3CH2CH2CH2CH2C(O)CH2CH2CH2CH2COONa, CH3CH2CH2CH2CH2CH2C(O)CH2CH2CH2COONa, CH3CH2CH2CH2CH2CH2CH2C(O)CH2CH2COONa, CH3CH2CH2CH2CH2CH2CH2CH2C(O)CH2COONa、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2OCH2CH2COONa、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)NHCH2COOK、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2NHC(O)CH2COOK、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH2COONa、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2OC(O)CH2COONa、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)COONa、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)COOH、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)COOLi, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)COONH4、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(O)COONa、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2C(CH3)2COOK、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2SO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2SO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2SO3Na、 CH3C(O)CH2CH2CH2CH2CH2SO3Na、 CH3C(O)CH2CH2CH2CH2SO3Na, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Naぁ (CH3)3CC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Naぁ (CH3)2CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Naぁ (CH2)5CHC(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2SO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2SO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2SO3Naぁ CH3C(O)CH2CH2CH2CH2CH2SO3Naぁ CH3C(O)CH2CH2CH2CH2SO3Naぁ CH3C(O)CH2CH2CH2SO3Naぁ CH3C(O)CH2CH2SO3Naぁ CH3C(O)CH2SO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OCH2CH2CH2SO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)NHCH2SO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2NHC(O)CH2SO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)SO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2C(O)OCH2SO3Na、 CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2OC(O)CH2SO3Naぁ CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3H, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3K, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3Li, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2CH2SO3NH4, CH3C(O)CH2CH2CH2CH2CH2CH2CH2CH2C(CH3)2SO3Na etc.

[0191] The hydrocarbon surfactant may be a surfactant represented by the following formula I: R-(XZ) n (I) (wherein R is a hydrophobic hydrocarbon moiety containing one or more saturated or unsaturated, acyclic or cyclic aliphatic groups; the percentage of the total of CH groups relative to the total of CH, CH, and CH groups in the one or more aliphatic groups is at least about 70%, and the hydrophobic moiety does not contain a siloxane unit; each X, which may be the same or different, represents an ionic hydrophilic moiety; each Z, which may be the same or different, represents one or more counter ions of the ionic hydrophilic moiety; and n is 1 to 3.)

[0192] Compound I exhibits low reactivity with the polymerization initiator and / or propagating fluoropolymer radical in the polymerization of fluoromonomers.

[0193] Compound I has the formula: [ka] (In the formula, Y + is hydrogen, ammonium, quaternary ammonium, nitrogen heterocycle, alkali metal, or alkaline earth.

[0194] Compound I has the following formula II: [ka] (In the formula, R 2’ and R 2’’ are the same or different and are saturated or unsaturated, acyclic or cyclic aliphatic groups having 4 to 16 carbon atoms; R 2’ and R 2’’ the percentage of the total of CH3 groups to the total of CH3, CH2 and CH groups in the group is at least about 70%, or 2’ and R 2’’ may be linked together to form a saturated or unsaturated aliphatic ring which may contain ether or ester linkages, provided that the percentage of the total of CH3 groups relative to the total of CH3, CH2, and CH groups in the ring is at least about 70%. 1 is hydrogen, methoxy, ethoxy or phenoxy. + is hydrogen, ammonium, quaternary ammonium, a nitrogen heterocycle, an alkali metal, or an alkaline earth.

[0195] As compound II, for example, the following compounds are preferred. [ka] Y in the above formula + may be hydrogen, ammonium, or an alkali metal.

[0196] Compound I has the following formula III: [ka] (In the formula, R 3 , R 4’ , and R 4’’ are the same or different and are hydrogen or a saturated or unsaturated, acyclic or cyclic aliphatic group having 4 to 16 carbon atoms; R 3 , R 4’ , and R 4’’ The percentage of total CH3 with respect to the total of CH3, CH2 and CH groups in the group is at least about 70%, provided that R 3 , R 4’ , and R 4’’At least one of the groups is not hydrogen, and R 4’ and R 4’’ is hydrogen, R 3 is not hydrogen, but R 3 is hydrogen, R 4’ and R 4’’ is not hydrogen. Y + is hydrogen, ammonium, quaternary ammonium, a nitrogen heterocycle, an alkali metal, or an alkaline earth.

[0197] As the compound III, for example, the following compounds are preferred. [ka] Y in the above formula + may be hydrogen, ammonium, or an alkali metal.

[0198] In the production method of the present disclosure, two or more of the above hydrocarbon surfactants may be used simultaneously.

[0199] Further, examples of hydrocarbon surfactants include the above-mentioned surfactant (1), the above-mentioned hydrocarbon surfactants having one or more carbonyl groups (excluding carbonyl groups in carboxyl groups), and specific hydrocarbon surfactants obtained by subjecting hydrocarbon surfactants having one or more carbonyl groups (excluding carbonyl groups in carboxyl groups) to radical treatment or oxidation treatment. The specific hydrocarbon surfactant is preferably a hydrocarbon surfactant having one or more of the above-mentioned carbonyl groups (excluding carbonyl groups in carboxyl groups), or a hydrocarbon surfactant having one or more carbonyl groups (excluding carbonyl groups in carboxyl groups) that has been subjected to radical treatment or oxidation treatment. By using a specific hydrocarbon surfactant that has been subjected to radical treatment or oxidation treatment, primary particles having a small average primary particle size and aspect ratio can be easily obtained, which allows the polymerization of monomers in an aqueous medium to proceed smoothly and makes it easy to produce a polymer.

[0200] The radical treatment may be any treatment that involves reacting radicals with a hydrocarbon surfactant. For example, this treatment involves adding deionized water and a hydrocarbon surfactant to a reactor, sealing the reactor, replacing the atmosphere with nitrogen, and then heating and pressurizing the reactor. Then, a polymerization initiator is added, the mixture is stirred for a certain period of time, and the pressure in the reactor is reduced to atmospheric pressure, followed by cooling. The oxidation treatment is a treatment that involves reacting an oxidizing agent with a carboxylic acid-type hydrocarbon surfactant. Examples of oxidizing agents include oxygen, ozone, hydrogen peroxide, manganese (IV) oxide, potassium permanganate, potassium dichromate, nitric acid, and sulfur dioxide.

[0201] The specific hydrocarbon surfactant is preferably at least one selected from the group consisting of surfactant (1) represented by general formula (1) above, surfactant (a) represented by formula (a), surfactant (b) represented by formula (b), surfactant (c) represented by formula (c), surfactant (d) represented by formula (d), and surfactants obtained by subjecting these surfactants (a) to (d) to radical treatment or oxidation treatment, and more preferably at least one selected from the group consisting of surfactant (a) represented by formula (a), surfactant (b) represented by formula (b), surfactant (c) represented by formula (c), surfactant (d) represented by formula (d), and surfactants obtained by subjecting these surfactants (a) to (d) to radical treatment or oxidation treatment.

[0202] The hydrocarbon surfactant used in the manufacturing method of the present disclosure is preferably a carboxylic acid hydrocarbon surfactant. Carboxylic acid hydrocarbon surfactants tend to have a shorter coagulation completion time than sulfate ester surfactants. However, according to the manufacturing method of the present disclosure, even when a carboxylic acid hydrocarbon surfactant is used, an aqueous dispersion having a long coagulation completion time can be manufactured. That is, the production method of the present disclosure is particularly suitable when the hydrocarbon surfactant is a carboxylic acid type hydrocarbon surfactant. The carboxylic acid type hydrocarbon surfactant is usually an anionic hydrocarbon surfactant having a hydrophilic portion of a carboxylate salt and a hydrophobic portion of a long-chain hydrocarbon portion such as an alkyl. Specifically, it is not limited as long as it has a carboxyl group (-COOH) or a group in which the hydrogen atom of the carboxyl group is substituted with an inorganic cation (for example, a metal atom, ammonium, etc.), and for example, from among the above-mentioned hydrocarbon surfactants, a hydrocarbon surfactant having a carboxyl group or a group in which the hydrogen atom of the carboxyl group is substituted with an inorganic cation can be used.

[0203] The carboxylic acid type hydrocarbon surfactant may be an aliphatic carboxylic acid type hydrocarbon surfactant, or may be a non-aliphatic carboxylic acid type hydrocarbon surfactant. In the present disclosure, the term "aliphatic carboxylic acid type hydrocarbon surfactant" refers to a carboxylic acid type hydrocarbon surfactant that does not contain a carbonyl group (excluding carbonyl groups in carboxyl groups and ester groups). The ester group refers to a group represented by -COO- or -OCO-.

[0204] As the carboxylic acid type hydrocarbon surfactant, for example, from among the hydrocarbon surfactants described above, a hydrocarbon surfactant having a carboxyl group or a group in which the hydrogen atom of the carboxyl group is substituted with an inorganic cation can be used.

[0205] The carboxylic acid type hydrocarbon surfactant includes surfactant (1), the surfactant represented by the above formula: R 6z (-LM)2 and anionic surfactants represented by the above formula: R 7zAmong the anionic surfactants represented by (-LM)3, at least one selected from the group consisting of those having a carboxyl group (-COOH) or a group in which the hydrogen atom of the carboxyl group is substituted with an inorganic cation (e.g., a metal atom, ammonium, etc.), surfactant (1-0A), and surfactants obtained by radical treatment or oxidation treatment of these surfactants is preferred. The above carboxylic acid type hydrocarbon surfactants may be used alone or as a mixture of two or more.

[0206] As the carboxylic acid type hydrocarbon surfactant, at least one selected from the group consisting of lauric acid, capric acid, myristic acid, pentadecylic acid, palmitic acid, and salts thereof, and compounds obtained by radical treatment or oxidation treatment of these compounds, is particularly preferred, at least one selected from the group consisting of lauric acid and salts thereof, and compounds obtained by radical treatment or oxidation treatment of these compounds, is more preferred, at least one selected from the group consisting of salts of lauric acid and compounds obtained by radical treatment or oxidation treatment of these, is even more preferred, and at least one selected from the group consisting of sodium laurate and compounds obtained by radical treatment or oxidation treatment of these, is even more preferred. The above salts include those in which the hydrogen of the carboxyl group is bonded to a metal atom of the above formula M, NR 101 4. Examples include, but are not limited to, imidazolium which may have a substituent, pyridinium which may have a substituent, or phosphonium which may have a substituent.

[0207] (Fluorine-containing surfactant) In the production method of the present disclosure, a fluorine-containing surfactant can be used instead of or in addition to a hydrocarbon surfactant. Examples of the fluorine-containing surfactant include anionic fluorine-containing surfactants. The anionic fluorine-containing surfactant may be, for example, a surfactant containing fluorine atoms and having a total carbon number of 20 or less excluding the anionic group.

[0208] The fluorine-containing surfactant may also be a surfactant containing fluorine in the anionic moiety having a molecular weight of 1,000 or less. The "anionic portion" refers to the portion of the fluorine-containing surfactant excluding the cation. For example, F(CF2) represented by the formula (I) below n1 In the case of COOM, "F(CF2) n1 The "COO" part.

[0209] Specific examples of the fluorine-containing surfactants include those described in U.S. Patent Application Publication Nos. 2007 / 0015864, 2007 / 0015865, 2007 / 0015866, 2007 / 0276103, 2007 / 0117914, 2007 / 142541, 2008 / 0015319, and U.S. Pat. No. 3,250,808. No. 3,271,341, JP 2003-119204 A, WO 2005 / 042593, WO 2008 / 060461, WO 2007 / 046377, JP 2007-119526 A, WO 2007 / 046482, WO 2007 / 046345, U.S. Patent Application Publication No. 2014 / 0228531, WO 2013 / 189824, and WO 2013 / 189826.

[0210] The anionic fluorine-containing surfactant may be a compound represented by the following general formula (N 0 ): X n0 -Rf n0 -Y 0 (N 0 ) (In the formula, X n0 is H, Cl or F. n0 is a linear, branched or cyclic alkylene group having 3 to 20 carbon atoms, in which some or all of the H's are substituted with F, and the alkylene group may contain one or more ether bonds, and some of the H's may be substituted with Cl. Y 0is an anionic group. Y 0 The anionic group may be -COOM, -SO2M, or -SO3M, and may be -COOM or -SO3M. M is H, metal atom, NR 7 4. An optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, wherein R 7 is H or an organic group. The metal atom includes alkali metals (Group 1) and alkaline earth metals (Group 2), such as Na, K, or Li. R 7 As for H or C 1-10 may be an organic group of H or C 1-4 may be an organic group of H or C 1-4 The alkyl group may be: M is H, a metal atom, or NR 7 4, and may be H, an alkali metal (Group 1), an alkaline earth metal (Group 2), or NR 7 4, which may be H, Na, K, Li, or NH4. Above Rf n0 may be one in which 50% or more of H is substituted with fluorine.

[0211] The general formula (N 0 ) as a compound represented by The following general formula (N 1 ): X n0 -(CF2) m1 -Y 0 (N 1 ) (In the formula, X n0 is H, Cl, or F, m1 is an integer of 3 to 15, and Y 0 is as defined above, a compound represented by the following general formula (N 2 ): Rf n1 -O-(CF(CF3)CF2O) m2 CFX n1 -Y 0 (N2 ) (In the formula, Rf n1 is a perfluoroalkyl group having 1 to 5 carbon atoms, m2 is an integer of 0 to 3, and X n1 is F or CF3, and Y 0 is as defined above, a compound represented by the following general formula (N 3 ): Rf n2 (CH2) m3 -(Rf n3 ) q -Y 0 (N 3 ) (In the formula, Rf n2 is a partially or fully fluorinated alkyl group having 1 to 13 carbon atoms which may contain an ether bond, m3 is an integer of 1 to 3, and Rf n3 is a linear or branched perfluoroalkylene group having 1 to 3 carbon atoms, q is 0 or 1, and Y 0 is as defined above, a compound represented by the following general formula (N 4 ): Rf n4 -O-(CY n1 Y n2 ) p CF2-Y 0 (N 4 ) (In the formula, Rf n4 is a linear or branched partially or fully fluorinated alkyl group having 1 to 12 carbon atoms, which may contain an ether bond and / or a chlorine atom, and Y n1 and Y n2 are the same or different and are H or F, p is 0 or 1, and Y 0 is as defined above.) and a compound represented by the general formula (N 5 ): [ka] (In the formula, X n2 , X n3 and X n4Rf may be the same or different and are H, F, or a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, which may contain an ether bond. n5 is a linear or branched partially or fully fluorinated alkylene group having 1 to 3 carbon atoms, which may contain an ether bond; L is a linking group; Y 0 is as defined above, where X n2 , X n3 , X n4 and Rf n5 The total number of carbon atoms is 18 or less.

[0212] The general formula (N 0 ) More specifically, the compound represented by the formula (I) is a perfluorocarboxylic acid (I) represented by the following general formula (I), a ω-H perfluorocarboxylic acid (II) represented by the following general formula (II), a perfluoroethercarboxylic acid (III) represented by the following general formula (III), a perfluoroalkyl alkylene carboxylic acid (IV) represented by the following general formula (IV), a perfluoroalkoxy fluorocarboxylic acid (V) represented by the following general formula (V), a perfluoroalkyl sulfonic acid (VI) represented by the following general formula (VII), a ω-H perfluoro sulfonic acid (VII) represented by the following general formula (VII), a perfluoroalkyl alkylene sulfonic acid (VIII) represented by the following general formula (VIII), an alkyl alkylene carboxylic acid (IX) represented by the following general formula (IX), a fluorocarboxylic acid (X) represented by the following general formula (X), an alkoxy fluoro sulfonic acid (XI) represented by the following general formula (XI), a compound (XII) represented by the following general formula (XII), a compound (XIII) represented by the following general formula (XIII), and the like.

[0213] The perfluorocarboxylic acid (I) is represented by the following general formula (I): F(CF2) n1 COOM (I) (wherein n1 is an integer of 3 to 14, and M is H, a metal atom, or NR 74. An optionally substituted imidazolium, an optionally substituted pyridinium, or an optionally substituted phosphonium, wherein R 7 is H or an organic group.

[0214] The ω-H perfluorocarboxylic acid (II) is represented by the following general formula (II): H(CF2) n2 COOM (II) (wherein n2 is an integer of 4 to 15, and M is as defined above).

[0215] The perfluoroether carboxylic acid (III) is represented by the following general formula (III): Rf 1 -O-(CF(CF3)CF2O) n3 CF(CF3)COOM (III) (In the formula, Rf 1 is a perfluoroalkyl group having 1 to 5 carbon atoms, n3 is an integer of 0 to 3, and M is as defined above.

[0216] The perfluoroalkyl alkylene carboxylic acid (IV) is represented by the following general formula (IV): Rf 2 (CH2) n4 Rf 3 COOM (IV) (In the formula, Rf 2 is a perfluoroalkyl group having 1 to 5 carbon atoms, and Rf 3 is a linear or branched perfluoroalkylene group having 1 to 3 carbon atoms, n4 is an integer of 1 to 3, and M is as defined above.

[0217] The alkoxyfluorocarboxylic acid (V) is represented by the following general formula (V): Rf 4 -O-CY 1 Y 2 CF2-COOM (V) (In the formula, Rf 4is a linear or branched partially or fully fluorinated alkyl group having 1 to 12 carbon atoms, which may contain an ether bond and / or a chlorine atom, and Y 1 and Y 2 are the same or different and are H or F, and M is as defined above.

[0218] The perfluoroalkylsulfonic acid (VI) is represented by the following general formula (VI): F(CF2) n5 SO3M (VI) (wherein n5 is an integer of 3 to 14, and M is as defined above).

[0219] The ω-H perfluorosulfonic acid (VII) is represented by the following general formula (VII): H(CF2) n6 SO3M (VII) (wherein n6 is an integer of 4 to 14, and M is as defined above).

[0220] The perfluoroalkyl alkylene sulfonic acid (VIII) is represented by the following general formula (VIII): Rf 5 (CH2) n7 SO3M (VIII) (In the formula, Rf 5 is a perfluoroalkyl group having 1 to 13 carbon atoms, n7 is an integer of 1 to 3, and M is as defined above.

[0221] The alkyl alkylene carboxylic acid (IX) is represented by the following general formula (IX): Rf 6 (CH2) n8 COOM (IX) (In the formula, Rf 6 is a linear or branched partially or fully fluorinated alkyl group having 1 to 13 carbon atoms which may contain an ether bond, n8 is an integer from 1 to 3, and M is as defined above.

[0222] The fluorocarboxylic acid (X) is represented by the following general formula (X): Rf 7 -O-Rf 8 -O-CF2-COOM (X) (In the formula, Rf 7 is a linear or branched partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, which may contain an ether bond and / or a chlorine atom, and Rf 8 is a linear or branched, partially or fully fluorinated alkyl group having 1 to 6 carbon atoms, and M is as defined above.

[0223] The alkoxyfluorosulfonic acid (XI) is represented by the following general formula (XI): Rf 9 -O-CY 1 Y 2 CF2-SO3M (XI) (In the formula, Rf 9 is a linear or branched alkyl group having 1 to 12 carbon atoms, which may contain an ether bond, and which may contain chlorine, and which is partially or completely fluorinated; Y 1 and Y 2 are the same or different and are H or F, and M is as defined above.

[0224] The compound (XII) is represented by the following general formula (XII): [ka] (In the formula, X 1 , X 2 and X 3 may be the same or different and are H, F and linear or branched partially or fully fluorinated alkyl groups having 1 to 6 carbon atoms which may contain ether bonds; Rf 10 is a perfluoroalkylene group having 1 to 3 carbon atoms, L is a linking group, and Y 0 is an anionic group. Y 0may be -COOM, -SO2M, or -SO3M, and may be -SO3M or COOM (wherein M is as defined above). Examples of L include a single bond and a partially or fully fluorinated alkylene group having 1 to 10 carbon atoms which may contain an ether bond.

[0225] The compound (XIII) is represented by the following general formula (XIII): Rf 11 -O-(CF2CF(CF3)O) n9 (CF2O) n10 CF2COOM (XIII) (In the formula, Rf 11 is a fluoroalkyl group containing chlorine and having 1 to 5 carbon atoms, n9 is an integer of 0 to 3, n10 is an integer of 0 to 3, and M is as defined above. Compound (XIII) is represented by the formula: CF2ClO(CF2CF(CF3)O) n9 (CF2O) n10 CF2COONH4 (a mixture having an average molecular weight of 750, wherein n9 and n10 are defined above).

[0226] As mentioned above, examples of the anionic fluorine-containing surfactant include carboxylic acid surfactants and sulfonic acid surfactants.

[0227] The fluorine-containing surfactant may be one type of fluorine-containing surfactant or a mixture containing two or more types of fluorine-containing surfactants.

[0228] (aqueous medium) The aqueous medium is a reaction medium for polymerization and refers to a liquid containing water. The aqueous medium is not particularly limited as long as it contains water, and may contain water and, for example, a fluorine-free organic solvent such as an ether or a ketone, and / or a fluorine-containing organic solvent having a boiling point of 40° C. or lower.

[0229] As the aqueous medium, an aqueous medium containing only water or an aqueous medium containing only water and a fluorine-free organic solvent is preferred, as it allows the polymerization to proceed smoothly, and an aqueous medium containing only water is more preferred.

[0230] The content of water in the aqueous medium is preferably 90% or more, more preferably 95% or more, even more preferably 99.0% or more, still more preferably 99.5% or more, particularly preferably 99.9% or more, and may be 100%, based on the mass of the aqueous medium, in order to allow the polymerization to proceed smoothly.

[0231] (additives) In the polymerization, additives can be used, such as buffers, pH adjusters, stabilizing aids, and dispersion stabilizers.

[0232] The stabilizing aid is preferably paraffin wax, fluorine-based oil, fluorine-based solvent, silicone oil, etc. The stabilizing aid may be used alone or in combination of two or more. The stabilizing aid is more preferably paraffin wax. The paraffin wax may be liquid, semi-solid, or solid at room temperature, but is preferably a saturated hydrocarbon having 12 or more carbon atoms. The melting point of the paraffin wax is usually preferably 40 to 65°C, more preferably 50 to 65°C.

[0233] The amount of the stabilizing aid used is preferably 0.1 to 12 mass % based on the mass of the aqueous medium used, and more preferably 0.1 to 8 mass %. It is desirable that the stabilizing aid is sufficiently hydrophobic so that it is completely separated from the aqueous dispersion after polymerization and does not become a contaminating component.

[0234] In one embodiment, the polymerization is carried out by charging an aqueous medium, a monomer, a compound having telogenicity, and an additive into a polymerization reactor, stirring the contents of the reactor, maintaining the reactor at a predetermined polymerization temperature, and then adding a polymerization initiator to initiate the polymerization reaction. After the initiation of the polymerization reaction, additional monomers, polymerization initiators, compounds having telogenicity, etc. may be added depending on the purpose.

[0235] Usually, the polymerization temperature is 5 to 120° C. and the polymerization pressure is 0.05 to 10 MPaG. The polymerization temperature and polymerization pressure are appropriately determined depending on the type of monomer used, the molecular weight of the desired fluoropolymer, and the reaction rate.

[0236] (Fluoromonomer) The fluoromonomer preferably has at least one double bond. Examples of the fluoromonomer include tetrafluoroethylene (TFE), hexafluoropropylene (HFP), chlorotrifluoroethylene (CTFE), vinyl fluoride, vinylidene fluoride (VDF), trifluoroethylene, fluoroalkyl vinyl ether, fluoroalkyl ethylene, fluoroalkyl allyl ether, trifluoropropylene, pentafluoropropylene, trifluorobutene, tetrafluoroisobutene, hexafluoroisobutene, and fluoroalkyl ethers represented by the general formula (100): CHX 101 =CX 102 Rf 101 (In the formula, X 101 and X 102 is H on one side and F on the other side, and Rf 101 is preferably at least one selected from the group consisting of a fluoromonomer represented by (a linear or branched fluoroalkyl group having 1 to 12 carbon atoms), a fluorinated vinyl heterocyclic compound, and a monomer that provides a crosslinking site.

[0237] Examples of the fluoroalkyl vinyl ether include: General formula (110): CF2=CF-ORf 111 (In the formula, Rf 111represents a perfluoroorganic group; General formula (120): CF2=CF-OCH2-Rf 121 (In the formula, Rf 121 is a perfluoroalkyl group having 1 to 5 carbon atoms), General formula (130): CF2=CFOCF2ORf 131 (In the formula, Rf 131 is a linear or branched perfluoroalkyl group having 1 to 6 carbon atoms, a cyclic perfluoroalkyl group having 5 to 6 carbon atoms, or a linear or branched perfluorooxyalkyl group having 2 to 6 carbon atoms and containing 1 to 3 oxygen atoms, General formula (140): CF2=CFO(CF2CF(Y 141 )O) m (CF2) n F (In the formula, Y 141 represents a fluorine atom or a trifluoromethyl group, m is an integer of 1 to 4, and n is an integer of 1 to 4. General formula (150): CF2=CF-O-(CF2CFY 151 -O) n -(CFY 152 ) m -A 151 (In the formula, Y 151 represents a fluorine atom, a chlorine atom, a -SO2F group, or a perfluoroalkyl group. The perfluoroalkyl group may contain an etheric oxygen and a -SO2F group. n represents an integer of 0 to 3. n Y 151 may be the same or different. 152 represents a fluorine atom, a chlorine atom, or a -SO2F group. m represents an integer of 1 to 5. m Y 152 may be the same or different. 151 -SO2X 151 , -COZ 151 or -POZ 152 Z 153 represents X 151 are F, Cl, Br, I, -OR151 or -NR 152 R 153 Represents Z. 151 , Z 152 and Z 153 are the same or different and are -NR 154 R 155 -OR 156 Represents R 151 , R 152 , R 153 , R 154 , R 155 and R 156 are the same or different and represent H, ammonium, an alkali metal, an alkyl group which may contain a fluorine atom, an aryl group, or a sulfonyl-containing group. It is preferable that the material is at least one selected from the group consisting of:

[0238] In the present disclosure, the term "perfluoroorganic group" refers to an organic group in which all hydrogen atoms bonded to carbon atoms are substituted with fluorine atoms. The perfluoroorganic group may have an ether oxygen atom.

[0239] The fluoromonomer represented by the general formula (110) is Rf 111 is a perfluoroalkyl group having 1 to 10 carbon atoms. The number of carbon atoms in the perfluoroalkyl group is preferably 1 to 5.

[0240] Examples of the perfluoroorganic group in the general formula (110) include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, and a perfluorohexyl group. The fluoromonomer represented by the general formula (110) further includes a fluoromonomer represented by the general formula (110) in which Rf 111 is a perfluoro(alkoxyalkyl) group having 4 to 9 carbon atoms, Rf 111 is the following formula:

[0241] [ka]

[0242] (wherein m represents 0 or an integer of 1 to 4), and Rf is a group represented by the following formula:

[0243] CF3CF2CF2-(O-CF(CF3)-CF2) n - (wherein n represents an integer of 1 to 4).

[0244] Among the fluoromonomers represented by the general formula (110), General formula (160): CF2=CF-ORf 161 (In the formula, Rf 161 Rf represents a perfluoroalkyl group having 1 to 10 carbon atoms. Fluoromonomers represented by 161 is preferably a perfluoroalkyl group having 1 to 5 carbon atoms.

[0245] The fluoroalkyl vinyl ether is preferably at least one selected from the group consisting of fluoromonomers represented by the general formulas (160), (130) and (140).

[0246] The fluoromonomer represented by general formula (160) is preferably at least one selected from the group consisting of perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), and perfluoro(propyl vinyl ether), and more preferably at least one selected from the group consisting of perfluoro(methyl vinyl ether) and perfluoro(propyl vinyl ether).

[0247] The fluoromonomer represented by the general formula (130) is preferably at least one selected from the group consisting of CF2=CFOCF2OCF3, CF2=CFOCF2OCF2CF3, and CF2=CFOCF2OCF2CF2OCF3.

[0248] The fluoromonomer represented by general formula (140) is preferably at least one selected from the group consisting of CF2=CFOCF2CF(CF3)O(CF2)3F, CF2=CFO(CF2CF(CF3)O)2(CF2)3F, and CF2=CFO(CF2CF(CF3)O)2(CF2)2F.

[0249] The fluoromonomer represented by general formula (150) is preferably at least one selected from the group consisting of CF2=CFOCF2CF2SO2F, CF2=CFOCF2CF(CF3)OCF2CF2SO2F, CF2=CFOCF2CF(CF2CF2SO2F)OCF2CF2SO2F and CF2=CFOCF2CF(SO2F)2.

[0250] The fluoromonomer represented by the general formula (100) is Rf 101 is a linear fluoroalkyl group, and Rf 101 More preferred is a fluoromonomer in which Rf is a linear perfluoroalkyl group. 101 The number of carbon atoms in the formula (100) is preferably 1 to 6. Examples of the fluoromonomer represented by the formula (100) include CH2=CFCF3, CH2=CFCF2CF3, CH2=CFCF2CF2CF3, CH2=CFCF2CF2CF2H, CH2=CFCF2CF2CF2CF3, CHF=CHCF3 (E-isomer), and CHF=CHCF3 (Z-isomer), and among these, 2,3,3,3-tetrafluoropropylene represented by CH2=CFCF3 is preferred.

[0251] Fluoroalkylethylenes include: General formula (170): CH2=CH-(CF2) n -X 171 (In the formula, X 171 is H or F, and n is an integer of 3 to 10.) is preferred, and fluoroalkylethylenes represented by CH2=CH-C4F9 and CH2=CH-C6F 13 It is more preferable that the material is at least one selected from the group consisting of:

[0252] Examples of the fluoroalkyl allyl ether include: General formula (180): CF2=CF-CF2-ORf 111 (In the formula, Rf 111 represents a perfluoroorganic group.

[0253] Rf of general formula (180) 111 is Rf in general formula (110) 111 is the same as Rf 111 is preferably a perfluoroalkyl group having 1 to 10 carbon atoms or a perfluoroalkoxyalkyl group having 1 to 10 carbon atoms. The fluoroalkyl allyl ether represented by general formula (180) is preferably at least one selected from the group consisting of CF2=CF-CF2-O-CF3, CF2=CF-CF2-O-C2F5, CF2=CF-CF2-O-C3F7, and CF2=CF-CF2-O-C4F9, more preferably at least one selected from the group consisting of CF2=CF-CF2-O-C2F5, CF2=CF-CF2-O-C3F7, and CF2=CF-CF2-O-C4F9, and even more preferably CF2=CF-CF2-O-CF2CF2CF3.

[0254] The fluorinated vinyl heterocycle includes a compound represented by the general formula (230): [ka] (In the formula, X 231 and X 232 are independently F, Cl, a methoxy group, or a fluorinated methoxy group; Y 231 is the formula Y 232 or formula Y 233 is.

[0255] [ka] (In the formula, Z 231 and Z 232are independently F or a fluorinated alkyl group having 1 to 3 carbon atoms.

[0256] Monomers that provide crosslinking sites include CF2=CFOCF2CF(CF3)OCF2CF2CN, CF2=CFOCF2CF(CF3)OCF2CF2COOH, CF2=CFOCF2CF(CF3)OCF2CF2CH2I, CF2=CFOCF2CF2CH2I, CH2=CFCF2OCF(CF3)CF2OCF(CF3)CN, CH2=CFCF2OCF(CF3)CF2OCF(CF3)COOH, CH2=CFCF2OCF( It is preferably at least one selected from the group consisting of CF3)CF2OCF(CF3)CH2OH, CH2=CHCF2CF2I, CH2=CH(CF2)2CH=CH2, CH2=CH(CF2)6CH=CH2, and CF2=CFO(CF2)5CN, and more preferably at least one selected from the group consisting of CF2=CFOCF2CF(CF3)OCF2CF2CN and CF2=CFOCF2CF2CH2I.

[0257] In the polymerization, the fluoromonomer may be polymerized with a non-fluorine-containing monomer, such as a hydrocarbon-based monomer reactive with the fluoromonomer.

[0258] Examples of the hydrocarbon monomer include alkenes such as ethylene, propylene, butylene, and isobutylene; alkyl vinyl ethers such as ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, isobutyl vinyl ether, and cyclohexyl vinyl ether; vinyl acetate, vinyl propionate, vinyl n-butyrate, vinyl isobutyrate, vinyl valerate, vinyl pivalate, vinyl caproate, vinyl caprylate, vinyl caprate, vinyl versatate, vinyl laurate, vinyl myristate, vinyl palmitate, vinyl stearate, vinyl benzoate, vinyl para-t-butylbenzoate, vinyl cyclohexanecarboxylate, vinyl monochloroacetate, vinyl adipate, vinyl acrylate, vinyl methacrylate, vinyl crotonate, vinyl sorbate, vinyl cinnamate, vinyl undecylenate, vinyl hydroxyacetate, and vinyl hydroxybenzoates. vinyl esters such as vinyl hydroxypropionate, vinyl hydroxybutyrate, vinyl hydroxyvalerate, vinyl hydroxyisobutyrate, and vinyl hydroxycyclohexanecarboxylate; alkyl allyl ethers such as ethyl allyl ether, propyl allyl ether, butyl allyl ether, isobutyl allyl ether, and cyclohexyl allyl ether; alkyl allyl esters such as ethyl allyl ester, propyl allyl ester, butyl allyl ester, isobutyl allyl ester, and cyclohexyl allyl ester; and (meth)acrylic acid esters such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, and vinyl methacrylate.

[0259] The fluorine-free monomer may also be a functional group-containing hydrocarbon monomer (excluding the monomer that provides a crosslinking site). Examples of the functional group-containing hydrocarbon monomer include hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, hydroxypropyl vinyl ether, hydroxybutyl vinyl ether, hydroxyisobutyl vinyl ether, and hydroxycyclohexyl vinyl ether; fluorine-free monomers having a carboxyl group such as acrylic acid, methacrylic acid, itaconic acid, succinic acid, succinic anhydride, fumaric acid, fumaric anhydride, crotonic acid, maleic acid, maleic anhydride, and perfluorobutenoic acid; fluorine-free monomers having a sulfo group such as vinyl sulfonic acid; fluorine-free monomers having a glycidyl group such as glycidyl vinyl ether and glycidyl allyl ether; fluorine-free monomers having an amino group such as aminoalkyl vinyl ether and aminoalkyl allyl ether; fluorine-free monomers having an amide group such as (meth)acrylamide and methylolacrylamide; fluorine-free monomers having a nitrile group such as acrylonitrile and methacrylonitrile.

[0260] In the production method of the present disclosure, it is preferable to use at least TFE as the fluoromonomer. In one embodiment, only TFE or a combination of TFE and a fluoromonomer other than TFE is used as the fluoromonomer. As the fluoromonomer other than TFE, among the above-mentioned fluoromonomers, fluoromonomers other than TFE can be mentioned, and for example, at least one selected from the group consisting of HFP, CTFE, fluoroalkyl ethylene, and fluoroalkyl allyl ether can be suitably used. Among them, HFP is preferable as the fluoromonomer other than TFE. In one embodiment, no fluorine-containing monomer is used as the monomer to be polymerized. In one embodiment, only TFE or a combination of TFE and a fluoromonomer other than TFE is used as the fluoromonomer, and no fluorine-containing monomer is used as the monomer to be polymerized. In one embodiment of the polymerization of the fluoromonomer, a monomer having a hydrophilic group is not used. Examples of the hydrophilic group include those described below as hydrophilic groups possessed by fluorine-containing compounds having a hydrophilic group.

[0261] In the above polymerization, the desired fluoropolymer can be obtained by polymerizing one or more of the above fluoromonomers.

[0262] (fluoropolymer) The polymerization can produce an aqueous dispersion containing a fluoropolymer. The fluoropolymer usually has a concentration of 8 to 50 mass% in the aqueous dispersion obtained by the polymerization. In the aqueous dispersion, the lower limit of the fluoropolymer concentration is preferably 10 mass%, more preferably 15 mass%, and the upper limit is preferably 40 mass%, more preferably 35 mass%.

[0263] The fluoropolymer content (solids concentration) (P mass %) in the aqueous dispersion can be determined by the formula: P = Z / X × 100 (mass %), based on the heating residue (Z g) obtained by placing approximately 1 g (X g) of a sample in an aluminum cup with a diameter of 5 cm, heating it at 110°C for 30 minutes, and then heating it at 300°C for 30 minutes.

[0264] In one embodiment of the production method, polytetrafluoroethylene (PTFE) is produced using at least TFE as the fluoromonomer. When the polymerization of TFE is completed, a polymer dispersion having a solid content of 1.0 to 50 mass % and an average primary particle size of 50 to 500 nm can be obtained. The lower limit of the solid content is preferably 5% by mass, more preferably 8% by mass, and the upper limit is not particularly limited, but may be 40% by mass or 35% by mass. The lower limit of the average primary particle size is preferably 100 nm, more preferably 150 nm, and the upper limit is preferably 400 nm, more preferably 350 nm.

[0265] Alternatively, the fluoropolymer powder can be obtained by coagulating the fluoropolymer in the aqueous dispersion and drying the coagulated product. The coagulated product may be washed before being dried.

[0266] The manufacturing method of the present disclosure can provide a fluoropolymer, such as a TFE polymer in which the monomer having the largest molar fraction in the polymer (hereinafter referred to as the "most abundant monomer") is TFE, a VDF polymer in which the most abundant monomer is VDF, or a CTFE polymer in which the most abundant monomer is CTFE.

[0267] The fluoropolymers preferably have an ion exchange ratio (IXR) greater than 53. Preferred fluoropolymers have no ionic groups or a limited number of ionic groups resulting in an ion exchange ratio greater than about 100. Preferred fluoropolymers preferably have an ion exchange ratio of 1000 or greater, more preferably 2000 or greater, and even more preferably 5000 or greater.

[0268] The TFE polymer may suitably be a TFE homopolymer or a copolymer comprising (1) TFE, (2) one or more fluorine-containing monomers other than TFE having 2 to 8 carbon atoms, particularly HFP or CTFE, and (3) other monomers. Examples of the (3) other monomers include perfluoroalkylethylenes having an alkyl group having 1 to 5 carbon atoms, particularly 1 to 3 carbon atoms; ω-hydroperfluoroolefins, etc.

[0269] The TFE polymer may also be a copolymer of TFE and one or more fluorine-free monomers. Examples of the fluorine-free monomers include alkenes such as ethylene and propylene; vinyl esters; and vinyl ethers. The TFE polymer may also be a copolymer of TFE and one or more fluorine-containing monomers having 2 to 8 carbon atoms and one or more fluorine-free monomers.

[0270] The fluoropolymers may be glassy, ​​plastic or elastomeric. They may be amorphous or partially crystalline and may be subject to compression-sintering, melt-processing or non-melt-processing.

[0271] In the production method of the present disclosure, for example, (I) as a non-melt-processable fluororesin, tetrafluoroethylene polymer [TFE polymer (PTFE)] can be suitably produced; (II) as a melt-processable fluororesin, ethylene / TFE copolymer [ETFE], TFE / HFP copolymer [FEP], TFE / perfluoro(alkyl vinyl ether) copolymer [PFA, MFA, etc.], TFE / perfluoroallyl ether copolymer, TFE / VDF copolymer, and electrolyte polymer precursor can be suitably produced; and (III) as a fluororubber, TFE / propylene copolymer, TFE / propylene / third monomer copolymer (the third monomer is VDF, HFP, CTFE, fluoroalkyl vinyl ethers, etc.), copolymers composed of TFE and fluoroalkyl vinyl ethers; HFP / ethylene copolymer, HFP / ethylene / TFE copolymer; VDF / HFP copolymer, HFP / ethylene copolymer, VDF / TFE / HFP copolymer; and the fluorine-containing segmented polymer described in Japanese Patent Publication No. 61-49327 can be suitably produced.

[0272] The fluorine substitution rate of the fluoropolymer calculated by the following formula is preferably 50% or more, more preferably 55% or more, even more preferably 60% or more, still more preferably 75% or more, and particularly preferably 80% or more. The fluorine substitution rate of the fluoropolymer is most preferably 90 to 100%.

[0273] The fluoropolymer is preferably a fluororesin, and particularly, a fluororesin having a fluorine substitution rate of 50% or more as calculated by the following formula is more preferred, a fluororesin having a fluorine substitution rate of more than 50% is even more preferred, a fluororesin having a fluorine substitution rate of 55% or more is even more preferred, a fluororesin having a fluorine substitution rate of 60% or more is even more preferred, a fluororesin having a fluorine substitution rate of 75% or more is even more preferred, a fluororesin having a fluorine substitution rate of 80% or more is particularly preferred, and a fluororesin having a fluorine substitution rate of 90 to 100%, i.e., a perfluororesin, is most preferred.

[0274] (formula) Fluorine substitution rate (%) = (number of fluorine atoms bonded to carbon atoms constituting the fluoropolymer) / ((number of hydrogen atoms bonded to carbon atoms constituting the fluoropolymer) + (number of fluorine atoms and chlorine atoms bonded to carbon atoms constituting the fluoropolymer)) × 100

[0275] The perfluororesin is more preferably a fluororesin having a fluorine substitution rate of 95 to 100%, further preferably PTFE or FEP, still more preferably PTFE, and particularly preferably low-molecular-weight PTFE.

[0276] The fluoropolymer may have a core-shell structure. Examples of the fluoropolymer having a core-shell structure include modified PTFE particles containing a core of high molecular weight PTFE and a shell of lower molecular weight PTFE or modified PTFE. Examples of such modified PTFE include the PTFE described in JP-A-2005-527652.

[0277] The core-shell structure may have the following structure. Core: TFE homopolymer Shell: TFE homopolymer Core: Modified PTFE Shell: TFE homopolymer Core: Modified PTFE Shell: Modified PTFE Core: TFE homopolymer Shell: Modified PTFE Core: Low molecular weight PTFE Shell: High molecular weight PTFE Core: High molecular weight PTFE Shell: Low molecular weight PTFE

[0278] In the fluoropolymer having the core-shell structure, the lower limit of the core ratio is preferably 0.5% by mass, more preferably 1.0% by mass, even more preferably 2.0% by mass, even more preferably 3.0% by mass, particularly preferably 5.0% by mass, and most preferably 10.0% by mass. The upper limit of the core ratio is preferably 99.5% by mass, more preferably 99.0% by mass, even more preferably 98.0% by mass, even more preferably 97.0% by mass, particularly preferably 95.0% by mass, and most preferably 90.0% by mass.

[0279] In the fluoropolymer having the core-shell structure, the lower limit of the shell ratio is preferably 0.5% by mass, more preferably 1.0% by mass, even more preferably 2.0% by mass, even more preferably 3.0% by mass, particularly preferably 5.0% by mass, and most preferably 10.0% by mass. The upper limit of the shell ratio is preferably 99.5% by mass, more preferably 99.0% by mass, even more preferably 98.0% by mass, even more preferably 97.0% by mass, particularly preferably 95.0% by mass, and most preferably 90.0% by mass.

[0280] PTFE can be produced by polymerizing at least TFE as a fluoromonomer. In the production of PTFE, various known modified monomers can also be used in combination. In the present disclosure, PTFE is a concept that includes not only TFE homopolymer but also a copolymer of TFE and a modified monomer (hereinafter referred to as "modified PTFE").

[0281] The modifying monomer is not particularly limited as long as it is copolymerizable with TFE, and examples thereof include fluoromonomers and non-fluoromonomers. The modifying monomer used may be one type or multiple types.

[0282] The non-fluoromonomer is not particularly limited and may be selected from the group consisting of monomers having the general formula: CH2=CR Q1 -LR Q2 (In the formula, R Q1 represents a hydrogen atom or an alkyl group. L represents a single bond, -CO-O-*, -O-CO-* or -O-. * represents R Q2 R represents the bond position with Q2 represents a hydrogen atom, an alkyl group or a nitrile group.

[0283] Examples of non-fluoromonomers include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, vinyl methacrylate, vinyl acetate, acrylic acid, methacrylic acid, acrylonitrile, methacrylonitrile, ethyl vinyl ether, cyclohexyl vinyl ether, etc. Of these, butyl methacrylate, vinyl acetate, and acrylic acid are preferred as non-fluoromonomers.

[0284] Examples of fluoromonomers include perfluoroolefins such as hexafluoropropylene (HFP); hydrogen-containing fluoroolefins such as trifluoroethylene and vinylidene fluoride (VDF); perhaloolefins such as chlorotrifluoroethylene; perfluorovinyl ethers; (perfluoroalkyl)ethylenes; and perfluoroallyl ethers.

[0285] From the viewpoint of reactivity with TFE, the modifying monomer preferably contains at least one selected from the group consisting of hexafluoropropylene, perfluoro(alkyl vinyl ether), and (perfluoroalkyl)ethylene. More preferably, it contains at least one selected from the group consisting of hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(propyl vinyl ether), (perfluorobutyl)ethylene, (perfluorohexyl)ethylene, and (perfluorooctyl)ethylene. More preferably, it contains hexafluoropropylene.

[0286] In the production of the TFE polymer, a saturated hydrocarbon having 12 or more carbon atoms that is substantially inert to the reaction and becomes liquid under the reaction conditions can also be used as a dispersion stabilizer for the reaction system in an amount of 2 to 10 parts by mass per 100 parts by mass of the aqueous medium. Furthermore, ammonium carbonate, ammonium phosphate, or the like can be added as a buffer to adjust the pH during the reaction.

[0287] Fine powders can be produced by coagulating aqueous dispersions of TFE polymers. The aqueous dispersions of TFE polymers can be used for various applications as fine powders after coagulation, washing, and drying. When coagulating the aqueous dispersions of TFE polymers, the aqueous dispersion obtained by polymerization of a polymer latex or the like is typically diluted with water to a polymer concentration of 5 to 20% by mass. In some cases, the pH is adjusted to neutral or alkaline, and the mixture is stirred in a vessel equipped with a stirrer with more vigor than during the reaction. The coagulation may be performed while stirring, using a coagulant such as a water-soluble organic compound (e.g., methanol or acetone), an inorganic salt (e.g., potassium nitrate or ammonium carbonate), or an inorganic acid (e.g., hydrochloric acid, sulfuric acid, or nitric acid). The coagulation may also be performed continuously using an in-line mixer or the like.

[0288] The concentration of the unaggregated TFE polymer in the wastewater resulting from the aggregation is preferably low from the viewpoint of productivity, more preferably less than 0.4% by mass, and particularly preferably less than 0.3% by mass.

[0289] According to the production method of the present disclosure, it is also possible to produce low-molecular-weight PTFE as PTFE.

[0290] Low-molecular-weight PTFE (also called PTFE micropowder) having a molecular weight of 600,000 or less has excellent chemical stability, extremely low surface energy, and is resistant to fibrillation. Therefore, it is suitable as an additive for improving the slipperiness and texture of coating surfaces in the production of plastics, inks, cosmetics, paints, greases, office automation equipment components, toners, etc. (see, for example, JP-A-10-147617).

[0291] When the low-molecular-weight PTFE obtained by the above polymerization is used as a powder, the aqueous dispersion can be coagulated to form powder particles.

[0292] According to the production method of the present disclosure, high molecular weight PTFE can also be produced as PTFE. In this disclosure, high molecular weight PTFE refers to non-melt-processible and fibrillating PTFE, while low molecular weight PTFE refers to melt-processible and non-fibrillating PTFE.

[0293] The term "non-melt processable" means that the melt flow rate cannot be measured at a temperature higher than the crystallization melting point in accordance with ASTM D 1238 and D 2116.

[0294] The presence or absence of fibrillating properties can be determined by "paste extrusion," a typical method for molding "high molecular weight PTFE powder," a powder made from a TFE polymer. Paste extrusion is usually possible because high molecular weight PTFE has fibrillating properties. If the unsintered molded product obtained by paste extrusion has no substantial strength or elongation, for example, if it breaks when pulled at 0% elongation, it can be considered to have no fibrillating properties.

[0295] The high-molecular-weight PTFE preferably has a standard specific gravity (SSG) of 2.130 to 2.280. The standard specific gravity is measured by a water displacement method in accordance with ASTM D 792 using a sample molded in accordance with ASTM D4895-89. In the present disclosure, "high molecular weight" means that the standard specific gravity is within the above range.

[0296] The above low molecular weight PTFE has a melt viscosity of 1×10 at 380°C. 2 ~7×10 5 The molecular weight is Pa·s. In the present disclosure, "low molecular weight" means that the melt viscosity is within the above range. The melt viscosity is measured in accordance with ASTM D 1238 using a flow tester (manufactured by Shimadzu Corporation) and a 2φ-8L die, with a 2g sample preheated to 380°C for 5 minutes, and maintained at the above temperature under a load of 0.7 MPa.

[0297] The high-molecular-weight PTFE has a melt viscosity significantly higher than that of the low-molecular-weight PTFE, making it difficult to measure its melt viscosity accurately. On the other hand, while the melt viscosity of the low-molecular-weight PTFE can be measured, it is difficult to obtain a molded article from the low-molecular-weight PTFE that can be used to measure its standard gravity, making it difficult to measure its standard gravity accurately. Therefore, in this disclosure, standard gravity is used as an indicator of the molecular weight of the high-molecular-weight PTFE, and melt viscosity is used as an indicator of the molecular weight of the low-molecular-weight PTFE. There are no known methods for directly determining the molecular weight of either the high-molecular-weight PTFE or the low-molecular-weight PTFE.

[0298] The high-molecular-weight PTFE preferably has a melting point of 333 to 347°C, more preferably 335 to 345°C. The low-molecular-weight PTFE preferably has a melting point of 322 to 333°C, more preferably 324 to 332°C. The melting point can be determined as the minimum point of the heat of fusion in a temperature range of 250 to 380°C using a differential scanning calorimeter RDC220 (DSC) manufactured by SII NanoTechnology Inc. After temperature calibration using indium and lead as standard samples, approximately 3 mg of PTFE powder is placed in an aluminum pan (crimp container) and heated at a rate of 10°C / min in an air flow of 200 ml / min.

[0299] The melting point of PTFE may be 322 to 347°C. When the PTFE is a high molecular weight PTFE, the upper limit of the melting point of the PTFE may be 347°C or less, 346°C or less, 345°C or less, 344°C or less, 343°C or less, 342°C or less, 341°C or less, or 340°C or less. When the PTFE is a high-molecular-weight PTFE, the lower limit of the melting point of the PTFE may be 333°C or higher, or 335°C or higher. When the PTFE is a low-molecular-weight PTFE, the upper limit of the melting point of the PTFE may be 333°C or lower, or 332°C or lower. When the PTFE is a low-molecular-weight PTFE, the lower limit of the melting point of the PTFE may be 322°C or higher, or 324°C or higher.

[0300] The average primary particle size of the primary particles of the low-molecular-weight PTFE is preferably 10 to 350 nm, more preferably 100 nm or more, even more preferably 150 nm or more, more preferably 400 nm or less, and even more preferably 350 nm or less.

[0301] The high-molecular-weight PTFE preferably exhibits at least one endothermic peak in the range of 333 to 347°C in a heat of fusion curve when PTFE that has not been heated to a temperature of 300°C or higher is heated at a rate of 10°C / min using a differential scanning calorimeter (DSC), and the heat of fusion between 290 and 350°C calculated from the heat of fusion curve is 52 mJ / mg or more. The heat of fusion of PTFE is more preferably 55 mJ / mg or more, and even more preferably 58 mJ / mg or more.

[0302] The manufacturing method of the present disclosure can also be used to produce TFE / HFP copolymer (FEP). The monomer composition (mass %) of FEP is preferably TFE:HFP=(60-95):(5-40), more preferably (85-92):(8-15).

[0303] In addition to TFE and HFP, other monomers copolymerizable with these monomers may be polymerized to obtain a copolymer of TFE, HFP, and other monomers as FEP. Examples of the other monomers include the above-mentioned fluorine-containing monomers (excluding TFE and HFP) and non-fluorine-containing monomers. One or more types of other monomers may be used. Perfluoro(alkyl vinyl ether) is preferred as the other monomer. The content of the other monomer units in FEP may be 0.1 to 2% by mass based on the total monomer units.

[0304] The manufacturing method of the present disclosure can also be used to produce TFE / perfluoro(alkyl vinyl ether) copolymers (PFA). The preferred monomer composition (mol %) of the TFE / perfluoro(alkyl vinyl ether) copolymer is TFE:perfluoro(alkyl vinyl ether)=(90-99.7):(0.3-10), more preferably (97-99):(1-3). The perfluoro(alkyl vinyl ether) is represented by the formula: CF2=CFORf 4 (In the formula, Rf 4 It is preferable to use one represented by a perfluoroalkyl group having 1 to 6 carbon atoms.

[0305] In addition to TFE and perfluoro(alkyl vinyl ether), other monomers copolymerizable with these monomers may be polymerized to obtain a copolymer of TFE, perfluoro(alkyl vinyl ether), and other monomers as a TFE / perfluoro(alkyl vinyl ether) copolymer. Examples of the other monomers include the above-mentioned fluorine-containing monomers (excluding TFE and perfluoro(alkyl vinyl ether)) and fluorine-free monomers. One or more types of other monomers may be used. The content of the other monomer units in the TFE / perfluoro(alkyl vinyl ether) copolymer may be 0.1 to 2% by mass based on the total monomer units.

[0306] 2.Aqueous dispersion The present disclosure also relates to an aqueous dispersion containing PTFE particles and an aqueous medium, wherein the PTFE particles have an average primary particle size of 100 to 500 nm and the content of a fluorine-containing compound having a hydrophilic group is small. The aqueous dispersion of the present disclosure can be produced by using the production method of the present disclosure.

[0307] The PTFE forming the PTFE particles in the aqueous dispersion may have the same structure as the PTFE obtained by the manufacturing method of the present disclosure. Therefore, the PTFE may be either high-molecular-weight PTFE or low-molecular-weight PTFE.

[0308] The average primary particle size of PTFE is 500 nm or less, preferably 450 nm or less, more preferably 400 nm or less, even more preferably 350 nm or less, still more preferably 300 nm or less, particularly preferably 250 nm or less, preferably 10 nm or more, more preferably 100 nm or more, and even more preferably 150 nm or more.

[0309] By carrying out the polymerization of the fluoromonomer in the presence of the above-mentioned surfactant, the average primary particle size of the PTFE can be easily adjusted to fall within the above-mentioned range.

[0310] The average primary particle size is the average particle size of primary particles dispersed in an aqueous dispersion, and differs from the average particle size of secondary particles (powders) formed by aggregation of primary particles. The average primary particle size can be measured by dynamic light scattering. First, a low-molecular-weight PTFE aqueous dispersion is prepared with a polymer solids concentration of approximately 1.0% by mass. Then, using dynamic light scattering, the measurement temperature is 25°C, the refractive index of the solvent (water) is 1.3328, the viscosity of the solvent (water) is 0.8878 mPa·s, and the number of accumulations is 70. For dynamic light scattering, an ELSZ-1000S (manufactured by Otsuka Electronics Co., Ltd.) can be used.

[0311] The average primary particle diameter can also be measured by the following method. The dispersion is diluted with water to a solid content of 0.15% by mass, and the transmittance of 550 nm incident light per unit length of the diluted latex obtained and the number-average particle diameter determined by measuring the unidirectional diameter using a transmission electron microscope photograph are measured to prepare a calibration curve. Using this calibration curve, the average particle diameter can be calculated from the measured transmittance of 550 nm incident light for each sample.

[0312] (Fluorine-containing compound having a hydrophilic group) By using the production method of the present disclosure, an aqueous dispersion with a low content of fluorine-containing compounds having hydrophilic groups can be obtained.

[0313] The content of the fluorine-containing compound having a hydrophilic group in the aqueous dispersion may be 500 mass ppb or less, or may be more than 0 mass ppb. The content of the fluorine-containing compound having a hydrophilic group in the aqueous dispersion may be less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 20 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, 3 mass ppb or less, or 1 mass ppb or less, relative to the PTFE particles. The content of the fluorine-containing compound having a hydrophilic group is most preferably less than the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0314] The hydrophilic group may be an anionic group, an acid group, or an acid-base group. Examples of the hydrophilic group include -NH, -PO, -OPO, -SO, -OSO, and -COOM (in each formula, M represents H, a metal atom, or NR 7y 4. An imidazolium which may have a substituent, a pyridinium which may have a substituent, or a phosphonium which may have a substituent, R 7y are H or organic groups and may be the same or different. Any two of them may be bonded to each other to form a ring.) Among them, -PO3M, -OPO3M, -SO3M, -OSO3M or -COOM is preferred as the hydrophilic group, -SO3M or -COOM is more preferred, and -COOM is even more preferred. R 7y The organic group in R is preferably an alkyl group. 7y As for H or C 1-10 is preferably an organic group represented by the formula: 1-4 The organic group is more preferably H or C 1-4 More preferred are alkyl groups of the formula:

[0315] The metal atom may be a monovalent or divalent metal atom, such as an alkali metal (Group 1) or an alkaline earth metal (Group 2), with Na, K, or Li being preferred.

[0316] Examples of the fluorine-containing compound having a hydrophilic group include those exemplified above as the fluorine-containing surfactant. Typical compounds as the fluorine-containing surfactant are those having a molecular weight of 1000 g / mol or less, preferably 800 g / mol or less.

[0317] In one embodiment of the aqueous dispersion, the aqueous dispersion is substantially free of a compound represented by the following general formula (1) as a fluorine-containing compound having a hydrophilic group. General formula (1): [X-Rf-A - ] i M i+ (Wherein X represents H, Cl, Br, F or I, Rf represents a linear or branched partially or fully fluorinated aliphatic group, or a linear or branched partially or fully fluorinated aliphatic group interrupted by at least one oxygen atom, A - is the acid group, M i+ represents a cation having a valence of i, where i is an integer of 1 to 3.

[0318] In one embodiment of the aqueous dispersion, the aqueous dispersion is substantially free of a compound represented by the following general formula (2) as a fluorine-containing compound having a hydrophilic group. General formula (2):[C n-1 F 2n-1 COO - ]M + (wherein n is an integer of 9 to 14, M + represents a cation.)

[0319] It is known that compounds represented by general formula (2) (perfluoroalkanoic acids) are formed during polymerization when perfluoroalkyl vinyl ethers or the like are used as modified monomers (see WO 2019 / 161153).

[0320] In one embodiment of the aqueous dispersion, the aqueous dispersion does not substantially contain a compound represented by the following general formula (3) as a fluorine-containing compound having a hydrophilic group. General formula (3):[R 1 -OL-CO2 - ]M + (In the formula, R 1 represents a linear or branched partially or fully fluorinated aliphatic group, or a linear or branched partially or fully fluorinated aliphatic group interrupted by at least one oxygen atom; L represents a linear or branched non-fluorinated, partially fluorinated or fully fluorinated alkylene group; M represents a + represents a cation.)

[0321] In one embodiment of the aqueous dispersion, the aqueous dispersion is substantially free of a compound represented by general formula (4) as a fluorine-containing compound having a hydrophilic group. General formula (4):[H-(CF2) m-1 CO2 - ]M + (wherein m is an integer of 4 to 20, M + represents a cation.)

[0322] In the present disclosure, "substantially free of any of the compounds represented by general formulas (1) to (4)" means that the content of any of the compounds represented by general formulas (1) to (4) in the aqueous dispersion is 500 mass ppb or less relative to the PTFE particles. The content of any of the compounds represented by general formulas (1) to (4) in the fluoropolymer may be less than 500 mass ppb, 450 mass ppb or less, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less relative to the PTFE particles. The above content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0323] The cation is H + , ammonium ions, alkali metal ions, alkaline earth metal ions, etc.

[0324] In one embodiment, the content of the compound represented by the following general formula (4-a3) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a3):[H-(CF2)3CO2 - ]M + (In the formula, M + represents a cation.)

[0325] The content of the compound represented by general formula (4-a3) may be less than 500 mass ppb, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0326] In one embodiment, the content of the compound represented by the following general formula (4-a4) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a4):[H-(CF2)4CO2 - ]M + (In the formula, M + represents a cation.)

[0327] The content of the compound represented by general formula (4-a4) may be less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0328] In one embodiment, the content of the compound represented by the following general formula (4-a5) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a5):[H-(CF2)5CO2 - ]M + (In the formula, M + represents a cation.)

[0329] The content of the compound represented by general formula (4-a5) may be less than 500 mass ppb, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0330] In one embodiment, the content of the compound represented by the following general formula (4-a6) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a6):[H-(CF2)6CO2 - ]M + (In the formula, M + represents a cation.)

[0331] The content of the compound represented by general formula (4-a6) may be less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0332] In one embodiment, the content of the compound represented by the following general formula (4-a7) in the aqueous dispersion is 450 ppb by mass or less relative to the PTFE particles. General formula (4-a7):[H-(CF2)7CO2 - ]M + (In the formula, M + represents a cation.)

[0333] The content of the compound represented by general formula (4-a7) may be 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The above content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0334] In one embodiment, the content of the compound represented by the following general formula (4-a8) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a8):[H-(CF2)8CO2 - ]M + (In the formula, M + represents a cation.)

[0335] The content of the compound represented by general formula (4-a8) may be less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0336] In one embodiment, the content of the compound represented by the following general formula (4-a9) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a9):[H-(CF2)9CO2 - ]M + (In the formula, M + represents a cation.)

[0337] The content of the compound represented by general formula (4-a9) may be less than 500 mass ppb, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0338] In one embodiment, the content of the compound represented by the following general formula (4-a10) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a10):[H-(CF2) 10 CO2 - ]M + (In the formula, M + represents a cation.)

[0339] The content of the compound represented by general formula (4-a10) may be less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0340] In one embodiment, the content of the compound represented by the following general formula (4-a11) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a11):[H-(CF2) 11 CO2 - ]M + (In the formula, M + represents a cation.)

[0341] The content of the compound represented by general formula (4-a11) may be less than 500 mass ppb, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0342] In one embodiment, the content of the compound represented by the following general formula (4-a12) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a12):[H-(CF2) 12 CO2 - ]M + (In the formula, M + represents a cation.)

[0343] The content of the compound represented by general formula (4-a12) may be less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0344] In one embodiment, the content of the compound represented by the following general formula (4-a13) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a13):[H-(CF2) 13 CO2 - ]M + (In the formula, M + represents a cation.)

[0345] The content of the compound represented by general formula (4-a13) may be less than 500 mass ppb, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The above content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0346] In one embodiment, the content of the compound represented by the following general formula (4-a14) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a14):[H-(CF2) 14 CO2 - ]M + (In the formula, M + represents a cation.)

[0347] The content of the compound represented by general formula (4-a14) may be less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0348] In one embodiment, the content of the compound represented by the following general formula (4-a15) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a15):[H-(CF2) 15 CO2 - ]M + (In the formula, M + represents a cation.)

[0349] The content of the compound represented by general formula (4-a15) may be less than 500 mass ppb, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0350] In one embodiment, the content of the compound represented by the following general formula (4-a16) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a16):[H-(CF2) 16 CO2 - ]M + (In the formula, M + represents a cation.)

[0351] The content of the compound represented by general formula (4-a16) may be less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0352] In one embodiment, the content of the compound represented by the following general formula (4-a17) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a17):[H-(CF2) 17 CO2 - ]M + (In the formula, M + represents a cation.)

[0353] The content of the compound represented by general formula (4-a17) may be less than 500 mass ppb, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The above content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0354] In one embodiment, the content of the compound represented by the following general formula (4-a18) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a18):[H-(CF2) 18 CO2 - ]M + (In the formula, M + represents a cation.)

[0355] The content of the compound represented by general formula (4-a18) may be less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0356] In one embodiment, the content of the compound represented by the following general formula (4-a19) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a19):[H-(CF2) 19 CO2 - ]M + (In the formula, M + represents a cation.)

[0357] The content of the compound represented by general formula (4-a19) may be less than 500 mass ppb, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The above content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0358] In one embodiment, the content of the compound represented by the following general formula (4-a7) in the aqueous dispersion is 450 mass ppb or less relative to the PTFE particles, and the content of the compound represented by the following general formula (4-a8) in the aqueous dispersion is 500 mass ppb or less relative to the PTFE particles. General formula (4-a7):[H-(CF2)7CO2 - ]M + (In the formula, M + represents a cation.) General formula (4-a8):[H-(CF2)8CO2 - ]M + (In the formula, M + represents a cation.)

[0359] In one embodiment, the content of the compound represented by general formula (4-a7) may be 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles, and the content of the compound represented by general formula (4-a8) may be less than 500 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The above contents are most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0360] In one embodiment, the content of the compound represented by the following general formula (4-a7) in the aqueous dispersion is 450 mass ppb or less relative to the PTFE particles, the content of the compound represented by the following general formula (4-a8) in the aqueous dispersion is 500 mass ppb or less relative to the PTFE particles, and the content of the compound represented by the following general formula (4-a13) in the aqueous dispersion is 500 mass ppb or less relative to the PTFE particles. General formula (4-a7):[H-(CF2)7CO2 - ]M + (In the formula, M + represents a cation.) General formula (4-a8):[H-(CF2)8CO2 - ]M + (In the formula, M + represents a cation.) General formula (4-a13):[H-(CF2) 13 CO2 - ]M + (In the formula, M + represents a cation.)

[0361] In one embodiment, the content of the compound represented by general formula (4-a7) is 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles, and the content of the compound represented by general formula (4-a8) is less than 500 mass ppb or less, 100 mass ppb or less, relative to the PTFE particles, The concentration may be 50 ppb by mass or less, 25 ppb by mass or less, 10 ppb by mass or less, less than 5 ppb by mass, or 1 ppb by mass or less, and the content of the compound represented by general formula (4-a13) may be less than 500 ppb by mass, 400 ppb by mass or less, 300 ppb by mass or less, 200 ppb by mass or less, 100 ppb by mass or less, 50 ppb by mass or less, 25 ppb by mass or less, 10 ppb by mass or less, less than 5 ppb by mass, or 1 ppb by mass or less, relative to the PTFE particles. The above content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0362] In one embodiment, the content of the compound represented by the following general formula (4-a7) in the aqueous dispersion is 450 mass ppb or less relative to the PTFE particles, the content of the compound represented by the following general formula (4-a8) in the aqueous dispersion is 500 mass ppb or less relative to the PTFE particles, the content of the compound represented by the following general formula (4-a13) in the aqueous dispersion is 500 mass ppb or less relative to the PTFE particles, and the content of the compound represented by the following general formula (4-a12) in the aqueous dispersion is 500 mass ppb or less relative to the PTFE particles. General formula (4-a7):[H-(CF2)7CO2 - ]M + (In the formula, M + represents a cation.) General formula (4-a8):[H-(CF2)8CO2 - ]M + (In the formula, M + represents a cation.) General formula (4-a13):[H-(CF2)13 CO2 - ]M + (In the formula, M + represents a cation.) General formula (4-a12):[H-(CF2) 12 CO2 - ]M + (In the formula, M + represents a cation.)

[0363] In one embodiment, the content of the compound represented by general formula (4-a7) is 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles, and the content of the compound represented by general formula (4-a8) is less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles, and The content of the compound represented by general formula (4-a13) may be less than 500 mass ppb, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles, and the content of the compound represented by general formula (4-a12) may be less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The above content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0364] In one embodiment, the content of the compound represented by the following general formula (4-a13) in the aqueous dispersion is 500 mass ppb or less relative to the PTFE particles, and the content of the compound represented by the following general formula (4-a12) in the aqueous dispersion is 500 mass ppb or less relative to the PTFE particles. General formula (4-a13):[H-(CF2) 13 CO2 - ]M + (In the formula, M + represents a cation.) General formula (4-a12):[H-(CF2) 12 CO2 - ]M + (In the formula, M + represents a cation.)

[0365] In one embodiment, the content of the compound represented by general formula (4-a13) is less than 500 mass ppb, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles, and the content of the compound represented by general formula (4-a12) is less than 500 mass ppb, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The above content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0366] In one embodiment, the content of the compound represented by the following general formula (4-a13) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles, the content of the compound represented by the following general formula (4-a12) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles, and the content of the compound represented by the following general formula (4-a7) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a13):[H-(CF2) 13 CO2 - ]M + (In the formula, M + represents a cation.) General formula (4-a12):[H-(CF2) 12 CO2- ]M + (In the formula, M + represents a cation.) General formula (4-a7):[H-(CF2)7CO2 - ]M + (In the formula, M + represents a cation.)

[0367] In one embodiment, the content of the compound represented by general formula (4-a13) is less than 500 ppb by mass, 400 ppb by mass or less, 300 ppb by mass or less, 200 ppb by mass or less, 100 ppb by mass or less, 50 ppb by mass or less, 25 ppb by mass or less, 10 ppb by mass or less, less than 5 ppb by mass, or 1 ppb by mass or less, relative to the PTFE particles, and the content of the compound represented by general formula (4-a12) is less than 500 ppb by mass, 100 ppb by mass or less, relative to the PTFE particles. The concentration of the compound represented by general formula (4-a7) may be 450 mass ppb or less, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The above content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0368] In one embodiment, the content of the compound represented by the following general formula (4-a13) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles, the content of the compound represented by the following general formula (4-a12) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles, the content of the compound represented by the following general formula (4-a7) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles, and the content of the compound represented by the following general formula (4-a8) in the aqueous dispersion is 500 ppb by mass or less relative to the PTFE particles. General formula (4-a13):[H-(CF2) 12 CO2 - ]M + (In the formula, M + represents a cation.) General formula (4-a12):[H-(CF2) 12 CO2 - ]M + (In the formula, M + represents a cation.) General formula (4-a7):[H-(CF2)7CO2 - ]M + (In the formula, M + represents a cation.) General formula (4-a8):[H-(CF2)8CO2 - ]M + (In the formula, M + represents a cation.)

[0369] In one embodiment, the content of the compound represented by general formula (4-a13) is less than 500 ppb by mass, 400 ppb by mass or less, 300 ppb by mass or less, 200 ppb by mass or less, 100 ppb by mass or less, 50 ppb by mass or less, 25 ppb by mass or less, 10 ppb by mass or less, less than 5 ppb by mass, or 1 ppb by mass or less, relative to the PTFE particles, and the content of the compound represented by general formula (4-a12) is less than 500 ppb by mass, 100 ppb by mass or less, 50 ppb by mass or less, 25 ppb by mass or less, 10 ppb by mass or less, less than 5 ppb by mass, or 1 ppb by mass or less, relative to the PTFE particles. The content of the compound represented by general formula (4-a7) may be 450 mass ppb or less, 400 mass ppb or less, 300 mass ppb or less, 200 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles, and the content of the compound represented by general formula (4-a8) may be less than 500 mass ppb or less, 100 mass ppb or less, 50 mass ppb or less, 25 mass ppb or less, 10 mass ppb or less, less than 5 mass ppb, or 1 mass ppb or less, relative to the PTFE particles. The above content is most preferably below the lower limit of quantitation when measured by liquid chromatography mass spectrometry (LC / MS).

[0370] In one embodiment, the aqueous dispersion contains a compound represented by general formula (4). The content of the compound represented by general formula (4) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a3): The content of the compound represented by general formula (4-a3) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a4): The content of the compound represented by general formula (4-a4) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a5). The content of the compound represented by general formula (4-a5) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a6): The content of the compound represented by general formula (4-a6) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a7): The content of the compound represented by general formula (4-a7) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a8): The content of the compound represented by general formula (4-a8) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a9): The content of the compound represented by general formula (4-a9) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a10). The content of the compound represented by general formula (4-a10) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a11). The content of the compound represented by general formula (4-a11) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a12). The content of the compound represented by general formula (4-a12) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a13). The content of the compound represented by general formula (4-a13) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a14): The content of the compound represented by general formula (4-a14) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a15). The content of the compound represented by general formula (4-a15) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a16). The content of the compound represented by general formula (4-a16) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a17). The content of the compound represented by general formula (4-a17) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a18). The content of the compound represented by general formula (4-a18) may be greater than 0 ppb by mass. In one embodiment, the aqueous dispersion contains a compound represented by general formula (4-a19). The content of the compound represented by general formula (4-a19) may be greater than 0 ppb by mass.

[0371] In one embodiment of the aqueous dispersion of the present disclosure, the dispersion is substantially free of a fluorine-containing surfactant.

[0372] In the present disclosure, "substantially free of fluorine-containing surfactant" means that the content of fluorine-containing surfactant in the aqueous dispersion is 10 ppm by mass or less, preferably 1 ppm by mass or less, more preferably 100 ppb by mass or less, even more preferably 10 ppb by mass or less, still more preferably 1 ppb by mass or less, and particularly preferably below the lower limit of quantitation of the fluorine-containing surfactant as measured by liquid chromatography-mass spectrometry (LC / MS).

[0373] The content of the fluorine-containing compound having a hydrophilic group in the aqueous dispersion can be determined by a known method, for example, by LC / MS analysis. First, methanol is added to the aqueous dispersion to perform extraction, and the resulting extract is analyzed by LC / MS. To further increase the extraction efficiency, treatments such as Soxhlet extraction and ultrasonic treatment may be performed. The obtained extract is concentrated by nitrogen purging as needed, and the fluorine-containing compounds having hydrophilic groups in the concentrated extract are measured by LC / MS. Molecular weight information is extracted from the obtained LC / MS spectrum, and its match with the structural formula of the candidate fluorine-containing compound having a hydrophilic group is confirmed. Thereafter, aqueous solutions containing five or more levels of the confirmed fluorine-containing compound having a hydrophilic group are prepared, and the aqueous solutions containing each level are subjected to LC / MS analysis. The relationship between the content and the area for that content is plotted, and a calibration curve is drawn. Then, using the calibration curve, the area of ​​the LC / MS chromatogram of the fluorine-containing compound having a hydrophilic group in the extract can be converted into the content of the fluorine-containing compound having a hydrophilic group. The resulting extract can be concentrated by purging with nitrogen, which allows the lower limit of quantitation of the measurement method to be lowered.

[0374] In one embodiment, the aqueous dispersion of the present disclosure is substantially free of nonionic surfactants.

[0375] In the present disclosure, "substantially free of nonionic surfactant" means that the content of nonionic surfactant in the aqueous dispersion is less than 1.0 mass % relative to the PTFE particles, preferably 0.5 mass % or less, and more preferably 0.1 mass % or less.

[0376] The content of nonionic surfactant in the aqueous dispersion is a value obtained by calculating from the heating residue (Yg) obtained by heating 1 g of the aqueous dispersion at 110°C for 30 minutes and the heating residue (Zg) obtained by further heating the obtained heating residue (Yg) at 300°C for 30 minutes using the formula: N = [(YZ) / Z] × 100 (mass%).

[0377] The aqueous dispersion of the present disclosure can be suitably used for the above-mentioned applications.

[0378] Although the embodiments have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims.

[0379] <1> According to a first aspect of the present disclosure, A method for producing a fluoropolymer, comprising polymerizing a fluoromonomer in the presence of a polymerization initiator, a compound having telogenicity, and an aqueous medium to obtain a fluoropolymer, The method is provided in which the polymerization initiator is a polymerization initiator that generates hydrophobic primary radicals. <2> According to a second aspect of the present disclosure, In the first aspect, there is provided a production method wherein the polymerization initiator is water-soluble. <3> According to a third aspect of the present disclosure, There is provided a production method according to the first or second aspect, wherein the polymerization initiator is a redox initiator. <4> According to a fourth aspect of the present disclosure, There is provided a production method according to any one of the first to third aspects, wherein the primary radical is a non-perfluoroalkyl radical or a perfluoroalkyl radical. <5> According to a fifth aspect of the present disclosure, There is provided a production method according to any one of the first to fourth aspects, wherein the primary radical is a perfluoroalkyl radical. <6> According to a sixth aspect of the present disclosure, There is provided a production method according to any one of the first to fifth aspects, wherein the primary radical is a primary radical having 1 to 7 carbon atoms. <7> According to a seventh aspect of the present disclosure, There is provided a production method according to a third aspect, wherein the redox initiator comprises a fluorine-containing alkylsulfinic acid or a salt thereof, and an oxidizing agent capable of oxidizing the fluorine-containing alkylsulfinic acid or a salt thereof. <8> According to an eighth aspect of the present disclosure, There is provided a production method according to any one of the first to seventh aspects, wherein the fluoromonomer is tetrafluoroethylene. <9> According to a ninth aspect of the present disclosure, There is provided a production method according to any one of the first to eighth aspects, wherein the fluoromonomer is tetrafluoroethylene, or a fluoromonomer other than tetrafluoroethylene and tetrafluoroethylene. <10> According to a tenth aspect of the present disclosure, According to any one of the first to ninth aspects, there is provided a production method wherein the fluoropolymer is a fluororesin. <11> According to an eleventh aspect of the present disclosure, According to any one of the first to tenth aspects, there is provided a production method in which the compound having telogenicity is a chain transfer agent. <12> According to a twelfth aspect of the present disclosure, There is provided a production method according to any one of the first to eleventh aspects, wherein the compound having telogenicity is a hydrocarbon surfactant. <13> According to a thirteenth aspect of the present disclosure, the polymerization initiator is a redox initiator, the reducing agent constituting the redox initiator is a fluorine-containing alkylsulfinic acid having 1 to 7 carbon atoms or a salt thereof, the oxidizing agent constituting the redox initiator is a persulfate, the compound having telogenicity is at least one selected from the group consisting of a chain transfer agent and a hydrocarbon surfactant, the chain transfer agent is at least one selected from the group consisting of ethane and propane; the hydrocarbon surfactant is dodecyl sulfate, the fluoromonomer is tetrafluoroethylene or a fluoromonomer other than tetrafluoroethylene and tetrafluoroethylene, The fluoropolymer is polytetrafluoroethylene. According to any one of the first to eleventh aspects, there is provided a manufacturing method. <14> According to a fourteenth aspect of the present disclosure, An aqueous dispersion containing polytetrafluoroethylene particles and an aqueous medium, the polytetrafluoroethylene particles have an average primary particle diameter of 100 to 500 nm; The content of the compound represented by the following general formula (4-a7) is 450 mass ppb or less relative to the polytetrafluoroethylene particles. An aqueous dispersion is provided. General formula (4-a7):[H-(CF2)7CO2 - ]M + (In the formula, M + represents a cation.) <15> According to a fifteenth aspect of the present disclosure, According to a fourteenth aspect, there is provided an aqueous dispersion having a content of a compound represented by the following general formula (4-a8) of 500 ppb by mass or less relative to the polytetrafluoroethylene particles: General formula (4-a8):[H-(CF2)8CO2 - ]M + (In the formula, M + represents a cation.) <16> According to a sixteenth aspect of the present disclosure, An aqueous dispersion containing polytetrafluoroethylene particles and an aqueous medium, the polytetrafluoroethylene particles have an average primary particle diameter of 100 to 500 nm; The content of the compound represented by the following general formula (4-a13) is 500 mass ppb or less relative to the polytetrafluoroethylene particles. An aqueous dispersion is provided. General formula (4-a13):[H-(CF2) 13 CO2 - ]M + (In the formula, M + represents a cation.) <17> According to a seventeenth aspect of the present disclosure, According to a sixteenth aspect, there is provided an aqueous dispersion in which the content of the compound represented by the following general formula (4-a12) is 500 ppb by mass or less relative to the polytetrafluoroethylene particles: General formula (4-a12):[H-(CF2) 12 CO2 - ]M + (In the formula, M + represents a cation.) <18> According to an eighteenth aspect of the present disclosure, According to any one of the fourteenth to seventeenth aspects, there is provided an aqueous dispersion, wherein the polytetrafluoroethylene particles are particles of low-molecular-weight polytetrafluoroethylene. <19> According to a nineteenth aspect of the present disclosure, According to any one of the fourteenth to eighteenth aspects, there is provided an aqueous dispersion that is substantially free of a fluorine-containing surfactant. <20> According to a twentieth aspect of the present disclosure, According to any one of the fourteenth to nineteenth aspects, there is provided an aqueous dispersion that is substantially free of a nonionic surfactant. [Example]

[0380] Next, embodiments of the present disclosure will be described with reference to examples, but the present disclosure is not limited to these examples.

[0381] The values ​​in the examples were measured by the following methods.

[0382] <Measurement of fluorine-containing compounds with hydrophilic groups> The content of the fluorine-containing compound having a hydrophilic group contained in the aqueous dispersion was determined as the content of the fluorine-containing compound having a hydrophilic group extracted from the aqueous dispersion.

[0383] 0. Extraction of fluorine-containing compounds with hydrophilic groups from aqueous dispersions An aqueous dispersion equivalent to 2 g of solids and 20 g of methanol were added to a 50 mL polypropylene centrifuge tube, and the tube was shaken in a sealed state to coagulate the fluoropolymer. The coagulated polymer and supernatant in the polypropylene centrifuge tube were placed in a cylindrical filter paper in a Soxhlet extractor. The 50 mL polypropylene centrifuge tube was then washed with 130 g of methanol, and the liquid remaining in the 50 mL polypropylene centrifuge tube and the polymer were combined and placed in a cylindrical filter paper in the Soxhlet extractor. Extraction was then repeated 20 times by Soxhlet extraction to obtain an extract. The mass of the obtained extract, m e (g) and specific gravity d at 20°C e (g / mL), the volume of the extract V can be calculated from the following equation (1):e (mL) was obtained. V e =m e / d e (1)

[0384] <Measurement of the compound represented by general formula (4) (measurement method 1)> The content of the compound represented by general formula (4) was calculated in terms of perfluorooctanoic acid.

[0385] 1. Calibration curve of perfluorooctanoic acid Five levels of methanol standard solutions of perfluorooctanoic acid with known concentrations were prepared, and measurements were performed using a liquid chromatograph mass spectrometer (Agilent, 6470B triple quadrupole LC-MS) using the dynamic MRM method. For each concentration range, a and b were calculated using a first-order approximation from the methanol standard solution concentration and the peak area of ​​perfluorooctanoic acid using the relationship (2). A=a×X+b (2) A: Peak area of ​​perfluorooctanoic acid X: Perfluorooctanoic acid concentration (ng / mL)

[0386] Measurement equipment configuration and LC-MS measurement conditions [Table 1]

[0387] MRM measurement parameters [Table 2]

[0388] 2. Content of the compound represented by general formula (4) contained in the aqueous dispersion The peak area of ​​the compound represented by general formula (4) with carbon number m contained in the extract was measured by the dynamic MRM method using a liquid chromatograph mass spectrometer.

[0389] MRM measurement parameters [Table 3]

[0390] The content of the compound represented by general formula (4) with carbon number m in the extract was calculated using relational formula (3), where a and b in relational formula (3) were determined from relational formula (2). X Cm =((A Cm -b) / a)×((50×m-5) / 413) (3) X Cm : Content (ng / mL) of the compound represented by general formula (4) with carbon number m in the extract A Cm : Peak area of ​​the compound represented by general formula (4) with carbon number m in the extract

[0391] The content of the compound represented by general formula (4) with carbon number m contained in the aqueous dispersion The content of the compound represented by general formula (4) having a carbon number m contained in the aqueous dispersion was calculated using relational formula (4). Y Cm =X Cm ×V e / twenty four) Y Cm : Content of the compound represented by general formula (4) having carbon number m contained in the aqueous dispersion (mass ppb / fluoropolymer) The lower limit of determination in Measurement Method 1 for the content of the compound represented by general formula (4) having a carbon number m contained in the aqueous dispersion is 5 ppb by mass / fluoropolymer.

[0392] <Measurement of compounds having 8 carbon atoms and represented by general formula (4) (Measurement Method 2)> The compound represented by the general formula (4) in which the number of carbon atoms m is 8 may be obtained by the following method. 1. Calibration curve of the compound represented by general formula (4) with carbon number m of 8 Five levels of methanol standard solutions of compounds represented by general formula (4) with known concentrations of carbon number m = 8 were prepared, and measurements were performed using a liquid chromatograph mass spectrometer (Agilent, 6470B triple quadrupole LC-MS) with the dynamic MRM method. For each concentration range, a' and b' were calculated using a first-order approximation based on the methanol standard solution concentration and the peak area of ​​the compound represented by general formula (4) with a prime number m = 8, using the relationship (2'). A'=a'×X'+b' (2') A': Peak area of ​​the compound represented by general formula (4) having 8 carbon atoms X': concentration (ng / mL) of the compound represented by general formula (4) in which the number of carbon atoms m is 8

[0393] The measurement equipment configuration and LC-MS measurement conditions used were those shown in Table 1.

[0394] The MRM parameters used were those listed in Table 3.

[0395] The content of the compound represented by general formula (4) in which the carbon number m is 8 in the extract was calculated using relational formula (3'). a' and b' in relational formula (3') were obtained from formula (2'). XCm' = ((Cm' - b') / a') (3') XCm': Content of the compound represented by general formula (4) in which the carbon number m is 8 in the extract (ng / mL) ACm': Peak area of ​​the compound in the extract that is represented by general formula (4) and has a carbon number m of 8

[0396] Content of the compound represented by general formula (4) in which the carbon number m is 8 contained in the aqueous dispersion The content of the compound represented by general formula (4) in which the carbon number m is 8, contained in the aqueous dispersion, was calculated using relational formula (4'). YCm' = XCm' × Ve / 2 (4') YCm': content of the compound having 8 carbon atoms and represented by general formula (4) contained in the aqueous dispersion (mass ppb / fluoropolymer) In Measurement Method 2, the lower limit of determination for the content of the compound having 8 carbon atoms and represented by general formula (4) contained in the aqueous dispersion is 5 ppb by mass / fluoropolymer.

[0397] <Solid content concentration> Approximately 1 g (X g) of sample was placed in a 5 cm diameter aluminum cup, heated at 110°C for 30 minutes, and then heated at 300°C for 30 minutes. Based on the heating residue (Z g), P was determined using the formula: P = Z / X × 100 (mass%).

[0398] <Melt viscosity> In accordance with ASTM D 1238, a flow tester (manufactured by Shimadzu Corporation) and a 2φ-8L die were used to measure a 2g sample that had been preheated to the measurement temperature (380°C) for 5 minutes under a load of 0.7 MPa while maintaining the temperature.

[0399] Average primary particle size Measurements were made using dynamic light scattering. An aqueous fluoropolymer dispersion was prepared with a fluoropolymer solids concentration of 1.0% by mass, and measurements were made at 25°C with an ELSZ-1000S (Otsuka Electronics Co., Ltd.) for a total of 70 measurements. The refractive index of the solvent (water) was 1.3328, and the viscosity of the solvent (water) was 0.8878 mPa s.

[0400] Using a differential scanning calorimeter RDC220 (DSC) manufactured by SII Nanotechnology, after temperature calibration was performed in advance using indium and lead as standard samples, approximately 3 mg of PTFE powder was placed in an aluminum pan (crimp container) and heated at a rate of 10°C / min in the temperature range of 250 to 380°C under an air flow of 200 ml / min, and the minimum point of the heat of fusion in the above range was taken as the melting point.

[0401] Comparative Example 1 An aqueous dispersion of low-molecular-weight PTFE and low-molecular-weight PTFE powder were obtained using the method described in Example 1 of WO 2009 / 020187, except that 480 mg of ethane was added as a chain transfer agent and 330 mg of ammonium persulfate [APS] as a polymerization initiator and the temperature in the tank was adjusted to 70±1°C. The solids concentration of the obtained aqueous dispersion of low-molecular-weight PTFE was 20.7% by mass, the average primary particle size was 187 nm, and the melt viscosity of the low-molecular-weight PTFE was 9800 Pa s.

[0402] Experimental Example 1 An aqueous dispersion of low-molecular-weight PTFE and powder of low-molecular-weight PTFE were obtained using the method described in Comparative Example 1, except that 250 mg of sodium trifluoromethylsulfinate and 330 mg of APS were added in that order as polymerization initiators. The solids concentration of the obtained aqueous dispersion of low-molecular-weight PTFE was 21.0 mass%, the average primary particle size was 210 nm, and the melt viscosity of the low-molecular-weight PTFE was 9500 Pa s.

[0403] Experimental Example 2 An aqueous dispersion of low-molecular-weight PTFE and powder of low-molecular-weight PTFE were obtained using the method described in Comparative Example 1, except that 660 mg of sodium trifluoromethylsulfinate and 330 mg of APS were added in that order as polymerization initiators. The solids concentration of the obtained aqueous dispersion of low-molecular-weight PTFE was 20.7 mass%, the average primary particle size was 209 nm, and the melt viscosity of the low-molecular-weight PTFE was 10,900 Pa s.

[0404] Experimental Example 3 An aqueous dispersion of low-molecular-weight PTFE and powder of low-molecular-weight PTFE were obtained using the method described in Comparative Example 1, except that 2640 mg of sodium trifluoromethylsulfinate and 330 mg of APS were added in that order as polymerization initiators. The solids concentration of the obtained aqueous dispersion of low-molecular-weight PTFE was 21.7 mass%, the average primary particle size was 221 nm, and the melt viscosity of the low-molecular-weight PTFE was 10,000 Pa s.

[0405] Experimental Example 4 An aqueous dispersion of low-molecular-weight PTFE and a powder of low-molecular-weight PTFE were obtained using the method described in Comparative Example 1, except that 660 mg of bis(difluoromethylsulfonyl)zinc and 330 mg of APS were added in that order as polymerization initiators. The solids concentration of the obtained aqueous dispersion of low-molecular-weight PTFE was 21.5 mass%, the average primary particle size was 298 nm, and the melt viscosity of the low-molecular-weight PTFE was 11,000 Pa s. The content of the compound represented by general formula (4) having eight carbon atoms contained in the aqueous dispersion, as determined by measurement (Measurement Method 2), was 190 ppb by mass / fluoropolymer.

[0406] Experimental Example 5 An aqueous dispersion of low-molecular-weight PTFE and powder of low-molecular-weight PTFE were obtained using the method described in Comparative Example 1, except that 26 mg of silver nitrate (I), 250 mg of sodium trifluoromethylsulfinate, and 330 mg of APS were added in that order as polymerization initiators. The solids concentration of the obtained aqueous dispersion of low-molecular-weight PTFE was 21.7 mass%, the average primary particle size was 212 nm, and the melt viscosity of the low-molecular-weight PTFE was 9000 Pa s.

[0407] Experimental Example 6 An aqueous dispersion of low-molecular-weight PTFE and powder of low-molecular-weight PTFE were obtained using the method described in Comparative Example 1, except that 264 mg of silver nitrate (I), 660 mg of sodium trifluoromethylsulfinate, and 330 mg of APS were added in that order as polymerization initiators. The solids concentration of the obtained aqueous dispersion of low-molecular-weight PTFE was 21.1 mass%, the average primary particle size was 199 nm, and the melt viscosity of the low-molecular-weight PTFE was 11,000 Pa s.

[0408] Experimental Example 7 An aqueous dispersion of low-molecular-weight PTFE and powder of low-molecular-weight PTFE were obtained using the method described in Comparative Example 1, except that 264 mg of silver nitrate (I), 1320 mg of sodium trifluoromethylsulfinate, and 330 mg of APS were added in that order as polymerization initiators. The solids concentration of the obtained aqueous dispersion of low-molecular-weight PTFE was 21.8 mass%, the average primary particle size was 213 nm, and the melt viscosity of the low-molecular-weight PTFE was 8000 Pa s.

[0409] Experimental Example 8 An aqueous dispersion of low-molecular-weight PTFE and powder of low-molecular-weight PTFE were obtained using the method described in Comparative Example 1, except that 43 mg of iron(II) sulfate heptahydrate, 250 mg of sodium trifluoromethylsulfinate, and 330 mg of APS were added in that order as polymerization initiators. The solids concentration of the obtained aqueous dispersion of low-molecular-weight PTFE was 21.3 mass%, the average primary particle size was 193 nm, and the melt viscosity of the low-molecular-weight PTFE was 112,000 Pa s.

[0410] Experimental Example 9 An aqueous dispersion of PTFE and PTFE powder were obtained using the method described in Comparative Example 1, except that 33 mg of sodium dodecyl sulfate was added as a hydrocarbon surfactant instead of the chain transfer agent, and 250 mg of sodium trifluoromethylsulfinate and 330 mg of APS were added, in that order, as polymerization initiators. The solids concentration of the obtained aqueous dispersion of PTFE was 23.8 mass%, the average primary particle size was 234 nm, and since the melt viscosity of the obtained PTFE could not be measured, the obtained PTFE was a high-molecular-weight PTFE and had a melting point of 333.9°C.

[0411] [Table 4]

Claims

1. A method for producing a fluoropolymer, comprising polymerizing a fluoromonomer in the presence of a polymerization initiator, a compound having telogenicity, and an aqueous medium to obtain a fluoropolymer, the method comprising: The polymerization initiator is a polymerization initiator that generates a hydrophobic primary radical, and the hydrophobic primary radical is a radical having 1 to 3 carbon atoms.

2. The method according to claim 1 , wherein the polymerization initiator is water-soluble.

3. 3. The method according to claim 1, wherein the polymerization initiator is a redox initiator.

4. 3. The method according to claim 1, wherein the primary radical is an alkyl radical, and the alkyl radical is a non-perfluoroalkyl radical or a perfluoroalkyl radical.

5. 3. The method according to claim 1, wherein the primary radical is a perfluoroalkyl radical.

6. 4. The method according to claim 3, wherein the redox initiator comprises a fluorine-containing alkylsulfinic acid or a salt thereof, and an oxidizing agent capable of oxidizing the fluorine-containing alkylsulfinic acid or a salt thereof.

7. 3. The method according to claim 1, wherein the fluoromonomer is tetrafluoroethylene.

8. 3. The method according to claim 1, wherein the fluoromonomer is tetrafluoroethylene or a fluoromonomer other than tetrafluoroethylene and tetrafluoroethylene.

9. 3. The method according to claim 1, wherein the fluoropolymer is a fluororesin, and the fluororesin is a partially crystalline fluoropolymer.

10. 3. The method according to claim 1, wherein the compound having telogenicity is a chain transfer agent.

11. 3. The method according to claim 1, wherein the compound having telogenicity is a hydrocarbon surfactant.

12. the polymerization initiator is a redox initiator, the reducing agent constituting the redox initiator is a fluorine-containing alkylsulfinic acid having 1 to 7 carbon atoms or a salt thereof, the oxidizing agent constituting the redox initiator is a persulfate, the compound having telogenicity is at least one selected from the group consisting of a chain transfer agent and a hydrocarbon surfactant, the chain transfer agent is at least one selected from the group consisting of ethane and propane; the hydrocarbon surfactant is dodecyl sulfate or a salt thereof, the fluoromonomer is tetrafluoroethylene or a fluoromonomer other than tetrafluoroethylene and tetrafluoroethylene, The fluoropolymer is polytetrafluoroethylene. The method according to claim 1 or 2.

13. A manufacturing method described in claim 1 or 2, wherein the fluorine substitution rate of the fluoropolymer, calculated by the following formula, is 55% or more. Fluorine substitution rate (%) = (number of fluorine atoms bonded to carbon atoms constituting the fluoropolymer) / ((number of hydrogen atoms bonded to carbon atoms constituting the fluoropolymer) + (number of fluorine atoms and chlorine atoms bonded to carbon atoms constituting the fluoropolymer)) × 100

14. A manufacturing method according to claim 13, wherein the fluorine substitution rate of the fluoropolymer is 60% or more.

15. An aqueous dispersion containing polytetrafluoroethylene particles and an aqueous medium, the polytetrafluoroethylene particles have an average primary particle size of 100 to 500 nm; The content of the compound represented by the following general formula (4-a7) is 450 mass ppb or less relative to the polytetrafluoroethylene particles. Aqueous dispersion. General formula (4-a7): [H-(CF)] ２ ) ７ CO ２ － M ＋ (In the formula, M ＋ represents a cation.)

16. The aqueous dispersion according to claim 15, wherein the content of the compound represented by the following general formula (4-a8) is 500 mass ppb or less relative to the polytetrafluoroethylene particles: General formula (4-a8): [H-(CF)] ２ ) ８ CO ２ － M ＋ (In the formula, M ＋ represents a cation.)

17. An aqueous dispersion containing polytetrafluoroethylene particles and an aqueous medium, the polytetrafluoroethylene particles have an average primary particle size of 100 to 500 nm; The content of the compound represented by the following general formula (4-a13) is 500 mass ppb or less relative to the polytetrafluoroethylene particles. Aqueous dispersion. General formula (4-a13): [H-(CF)] ２ ) １３ CO ２ － M ＋ (In the formula, M ＋ represents a cation.)

18. The aqueous dispersion according to claim 17, wherein the content of the compound represented by the following general formula (4-a12) is 500 ppb by mass or less relative to the polytetrafluoroethylene particles: General formula (4-a12): [H-(CF)] ２ ) １２ CO ２ － M ＋ (In the formula, M ＋ represents a cation.)

19. The polytetrafluoroethylene particles are particles of low-molecular-weight polytetrafluoroethylene, and the low-molecular-weight polytetrafluoroethylene has a melt viscosity of 1×10 at 380° C. ２ ~7 x 10 ５ 18. The aqueous dispersion according to claim 15 or 17, wherein the viscosity is Pa·s.

20. 18. The aqueous dispersion according to claim 15 or 17, wherein the content of the fluorine-containing surfactant in the aqueous dispersion is 10 ppm by mass or less.

21. 18. The aqueous dispersion according to claim 15, wherein the content of the nonionic surfactant in the aqueous dispersion is less than 1.0% by mass relative to the polytetrafluoroethylene particles.

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