Composition containing fluorine-containing monomer and fluoride ions, method for producing fluorine-containing monomer having reduced fluoride ion content, and method for purifying fluorine-containing monomer

Abstract

The purpose of the present invention is to provide: a composition containing a fluorine-containing monomer and fluoride ions in which the amount of fluoride ions mixed into the fluorine-containing monomer is small; and a method for producing a fluorine-containing monomer having a further reduced fluoride ion content from the fluorine-containing monomer in which fluoride ions are mixed. And a method for purifying a fluorine-containing monomer into which fluoride ions have been mixed. The present invention pertains to a composition containing a fluorine-containing monomer (M) and fluoride ions, the fluoride ion content being 0.01-1000 ppm by mass relative to the mass of the composition, and the fluorine-containing monomer (M) being at least one monomer selected from the group consisting of compounds represented by formula (M1), compounds represented by formula (M2), and compounds represented by formula (M3). In the formula, each of R1-R10 independently represents a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group.

Description

TECHNICAL FIELD

[0001] The present application relates to a composition containing a fluorine-containing monomer and a fluoride ion, a manufacturing method of a fluorine-containing monomer with reduced content of a fluoride ion, and a refining method of a fluorine-containing monomer, and the like. BACKGROUND

[0002] A specific fluorine-containing monomer is used as a raw material for polymerization to obtain a fluorine-containing polymer. For example, a fluorine-containing polymer obtained by polymerization of perfluoro(2-methylene-4-methyl-1,3-dioxolane) having a ring structure is very useful as an electronic component, an optical material, and the like.

[0003] A specific fluorine-containing monomer is likely to polymerize during storage. Therefore, for the purpose of stabilizing the storage of the monomer, a technique for suppressing polymerization has been reported (Patent Documents 1 or 2). Patent Document 1 discloses a monomer composition containing a fluorine-containing monomer and 2,6-di-tert-butyl-p-cresol or the like. Patent Document 2 discloses a method for stabilizing perfluoro(2-methylene-4-methyl-1,3-dioxolane) by allowing a specific structure of a hydroxyl group-containing fluorine-containing aromatic compound to be present in a composition containing perfluoro(2-methylene-4-methyl-1,3-dioxolane).

[0004] PRIOR ART DOCUMENTS PATENT DOCUMENTS Patent Document 1: International Publication No. 2018 / 062193 Patent Document 2: International Publication No. 2020 / 130122 SUMMARY

[0005] PROBLEMS TO BE SOLVED BY THE INVENTION The present inventors have noted that a specific fluorine-containing monomer decomposes over time and generates a fluoride ion during storage, for example, resulting in the mixing of the fluoride ion into the fluorine-containing monomer.

[0006] MEANS OF SOLVING THE PROBLEMS Further, the present inventors have learned that, once a fluoride ion is mixed into a fluorine-containing monomer at a high concentration, the following problems are caused: the yield decreases when the fluorine-containing monomer is polymerized to manufacture a fluorine-containing polymer; the fluoride ion reacts with the fluorine-containing monomer, and the concentration of the fluorine-containing monomer decreases; and a polymer obtained by polymerization of the fluorine-containing monomer contains, after being subjected to heating, a metal fluoride contained in the fluorine-containing monomer as one kind of fluoride ion in the polymer after polymerization, and the metal fluoride acts on a COOH group or the like at the end of the polymer during heating, a decarboxylation reaction occurs, and as a result, the polymer decomposes (the thermal stability of the polymer decreases), and the like.

[0007] The present inventors have found that the fluoride ion mixed into a fluorine-containing monomer (M) can be reduced simply and effectively by activated carbon adsorption or washing.

[0008] An object of the present application is to provide a composition containing a fluorine-containing monomer and a fluoride ion with a small amount of the fluoride ion mixed into the fluorine-containing monomer, a method of producing a fluorine-containing monomer with a further reduced content of a fluoride ion from a fluorine-containing monomer into which a fluoride ion is mixed, a method of refining a fluorine-containing monomer into which a fluoride ion is mixed, and the like.

[0009] The present application includes, for example, the following modes.

[0010] Item 1. A composition containing a fluorine-containing monomer (M) and a fluoride ion, wherein the content of the fluoride ion is 0.01 to 1000 mass ppm with respect to the mass of the composition, the above-mentioned fluorine-containing monomer (M) is at least one monomer selected from the group consisting of a compound represented by formula (M1), a compound represented by formula (M2), and a compound represented by formula (M3), in the formula, R 1 and R 2 are each independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group, in the formula, R 3 , R 4 , R 5 , and R 6 are each independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group, in the formula, R 7 , R 8 , R 9 , and R 10 are each independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group.

[0011] Item 2. The composition according to item 1, wherein the above-mentioned fluorine-containing monomer (M) is at least one compound selected from the group consisting of a compound represented by the following formula (M1-1), a compound represented by the following formula (M2-1), a compound represented by the following formula (M2-2), a compound represented by the following formula (M3-1), and a compound represented by the following formula (M3-2). Item 3. The composition according to item 1 or 2, wherein the above-mentioned fluorine-containing monomer (M) is a compound represented by the following formula (M3-1). Item 4. The composition according to item 3, further containing a compound represented by the following formula (C). Item 5. The composition as described in Item 4, wherein the content of the compound represented by the above formula (C) is 0.01 to 10% by mass relative to the composition.

[0012] Item 6. The composition of any one of items 1 to 5, wherein the fluoride ion content is 50 to 600 ppm by mass relative to the composition.

[0013] Item 7. The composition as described in Item 1, wherein the fluorinated monomer (M) is a compound represented by the following formula (M3-1). The fluoride ion content is 50 to 600 ppm by mass relative to the composition.

[0014] Item 8. A method for manufacturing a fluorinated monomer (M), comprising a method for manufacturing a fluorinated monomer (M) with a further reduced fluoride ion content from a fluorinated monomer (M) mixed with fluoride ions, wherein, The process includes treating a fluorinated monomer (M) contaminated with fluoride ions using at least one method selected from activated carbon adsorption and cleaning, thereby reducing the amount of fluoride ions. The fluoride ion content in the manufactured fluorinated monomer (M) ranges from 0.01 to 1000 ppm by mass. The fluorinated monomer (M) mentioned above is at least one monomer selected from the compounds shown in formula (M1), formula (M2), and formula (M3). In the formula, R 1 and R 2 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. In the formula, R 3 R 4 R 5 and R 6 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. In the formula, R 7 R 8 R 9 and R 10 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group.

[0015] Item 9. The manufacturing method as described in Item 8, wherein the method for treating the fluorinated monomer (M) mixed with fluoride ions is activated carbon adsorption.

[0016] Item 10. The manufacturing method as described in Item 9, wherein the activated carbon adsorption treatment is a method of distilling a fluorinated monomer (M) mixed with fluoride ions, and then subjecting the distilled fluorinated monomer (M) to activated carbon adsorption treatment.

[0017] Item 11. The manufacturing method as described in Item 8, wherein the cleaning is performed using water or an alkaline aqueous solution.

[0018] Item 12. The manufacturing method as described in any one of items 8 to 11, wherein, The fluorinated monomer (M) mentioned above is at least one compound selected from the following formula (M1-1), the following formula (M2-1), the following formula (M2-2), the following formula (M3-1), and the following formula (M3-2). Item 13. The manufacturing method as described in any one of items 8 to 11, wherein, The fluorinated monomer (M) mentioned above is a compound represented by the following formula (M3-1). Item 14. The manufacturing method as described in any one of items 8 to 13, wherein, The fluoride ion content in the manufactured fluorinated monomer (M) is 50 to 600 ppm by mass.

[0019] Item 15. The manufacturing method as described in Item 8, wherein, The fluorinated monomer (M) mentioned above is a compound represented by the following formula (M3-1). The methods for treating fluorinated monomers (M) that have been mixed with fluoride ions are as follows: (1), (2) or (3). (1) A method for activated carbon adsorption treatment of fluorine-containing monomers (M) mixed with fluoride ions; (2) A method of distilling a fluorine-containing monomer (M) mixed with fluoride ions, and then subjecting the distilled fluorine-containing monomer (M) to activated carbon adsorption treatment. (3) A method for cleaning fluorine-containing monomers (M) mixed with fluoride ions using water or alkaline aqueous solutions. The fluoride ion content in the manufactured fluorinated monomer (M) is 50 to 600 ppm by mass.

[0020] Item 16. A method for purifying a fluorinated monomer (M) mixed with fluoride ions, wherein, The process includes treating a fluorinated monomer (M) contaminated with fluoride ions using at least one method selected from activated carbon adsorption and cleaning, thereby reducing the amount of fluoride ions. The fluorinated monomer (M) mentioned above is at least one monomer selected from the compounds shown in formula (M1), formula (M2), and formula (M3). In the formula, R 1 and R 2 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. In the formula, R 3 R 4 R 5 and R 6 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. In the formula, R 7 R 8 R 9 and R 10 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group.

[0021] Item 17. The purification method as described in Item 16, wherein the fluoride ion content in the purified fluorinated monomer (M) is 0.01 to 1000 ppm by mass.

[0022] Item 18. The purification method as described in Item 16, wherein the fluoride ion content in the purified fluorinated monomer (M) is 50 to 600 ppm by mass.

[0023] Item 19. The purification method as described in Item 16, wherein the method for treating the fluorinated monomer (M) mixed with fluoride ions is activated carbon adsorption.

[0024] Item 20. The purification method as described in Item 19, wherein the activated carbon adsorption treatment is a method of distilling a fluorinated monomer (M) mixed with fluoride ions, and then subjecting the distilled fluorinated monomer (M) to activated carbon adsorption treatment.

[0025] Item 21. The refining method as described in Item 16, wherein the above-mentioned cleaning is a cleaning using water or an alkaline aqueous solution.

[0026] Item 22. The refining method as described in any one of items 16 to 21, wherein, The fluorinated monomer (M) mentioned above is at least one compound selected from the following formula (M1-1), the following formula (M2-1), the following formula (M2-2), the following formula (M3-1), and the following formula (M3-2). Item 23. The refining method as described in any one of items 16 to 21, wherein, The fluorinated monomer (M) mentioned above is a compound represented by the following formula (M3-1). Item 24. The purification method as described in Item 23, wherein the fluorinated monomer (M) mixed with fluoride ions is a fluorinated monomer mixed with fluoride ions and a compound represented by the following formula (C). Item 25. The purification method as described in Item 24, wherein the content of the compound represented by the above formula (C) in the purified fluorinated monomer (M) is 100 to 100,000 ppm by mass.

[0027] Item 26. The refining method as described in Item 16, wherein, The fluorinated monomer (M) mentioned above is a compound represented by the following formula (M3-1). The fluorinated monomer (M) incorporating fluoride ions is a fluorinated monomer incorporating fluoride ions and a compound represented by the following formula (C). The methods for treating fluorinated monomers (M) that have been mixed with fluoride ions are as follows: (1), (2) or (3). (1) A method for activated carbon adsorption treatment of fluorine-containing monomers (M) mixed with fluoride ions; (2) A method of distilling a fluorine-containing monomer (M) mixed with fluoride ions, and then subjecting the distilled fluorine-containing monomer (M) to activated carbon adsorption treatment. (3) A method for cleaning fluorine-containing monomers (M) mixed with fluoride ions using water or alkaline aqueous solutions. The fluoride ion content in the manufactured fluorinated monomer (M) is 50–600 ppm by mass. The content of the compound represented by the above formula (C) in the purified fluorinated monomer (M) is 100 to 100,000 ppm by mass.

[0028] Invention Effects According to the present invention, a method for reducing fluoride ions mixed in a specific fluorinated monomer (a method for purifying fluorinated monomers) can be provided. By using this method, a composition containing fluorinated monomers and fluoride ions with a low amount of fluoride ions mixed in with the fluorinated monomer can be provided, and a fluorinated monomer with a further reduced fluoride ion content can be manufactured from the fluorinated monomer mixed with fluoride ions. Detailed Implementation

[0029] The above description of the present invention is not intended to describe all embodiments or implementations of the present invention.

[0030] The following description of the present invention provides more specific examples of implementation methods.

[0031] In some parts of this invention, guidance is provided by way of example, and such examples may be used in various combinations.

[0032] In all cases, the illustrated group serves as a non-exclusive and representative group.

[0033] All publications, patents and patent applications referenced in this specification may be incorporated herein by direct reference.

[0034] TERMS Unless otherwise specified, the symbols and abbreviations in this specification may be understood, in the context of this specification, as commonly used in the technical field to which this invention pertains.

[0035] In this specification, the use of the word "contains" is intended to include both the meaning of "substantially constitutes" and the meaning of "composed of".

[0036] Unless otherwise specified, the procedures, treatments, or operations described in this instruction manual can be performed at room temperature. In this instruction manual, room temperature may refer to a temperature in the range of 10 to 40°C.

[0037] In this specification, the expression "Cn-Cm" (where n and m are numbers) means, as commonly understood by those skilled in the art, a number of carbon atoms that is n or more and m or less.

[0038] Unless otherwise specified by those skilled in the art, the description of compounds in this specification includes all stereoisomers (enantiomers, diastereomers, geometric isomers, etc.).

[0039] In this specification, unless otherwise specified, "alkyl" includes straight-chain, branched, and cyclic alkyl groups. Alkyl groups can be straight-chain or branched.

[0040] The number of carbon atoms in an alkyl group can be, for example, 1–12, 1–6, 1–5, 1–4, 1–3, 6, 5, 4, 3, 2 or 1.

[0041] Examples of alkyl groups include: straight-chain or branched alkyl groups such as methyl, ethyl, propyl (e.g., n-propyl, isopropyl), butyl (e.g., n-butyl, isobutyl, sec-butyl, tert-butyl), pentyl (e.g., n-pentyl, tert-pentyl, neopentyl, isopentyl, sec-pentyl, 3-pentyl), hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, etc.; and cyclic alkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc.

[0042] Unless otherwise specified in this specification, "fluoroalkyl" includes linear, branched, or cyclic alkyl groups in which at least one hydrogen atom is replaced by a fluorine atom. Fluoroalkyl groups can be linear or branched.

[0043] The number of carbon atoms in a fluoroalkyl group can be, for example, 1–12, 1–6, 1–5, 1–4, 1–3, 6, 5, 4, 3, 2 or 1.

[0044] The number of fluorine atoms in a fluoroalkyl group can be more than one (e.g., 1 to 3, 1 to 5, 1 to 9, 1 to 11, 1 to the maximum number that can be substituted).

[0045] Fluoroalkyl groups include perfluoroalkyl groups. Perfluoroalkyl groups are alkyl groups in which all hydrogen atoms are replaced by fluorine atoms.

[0046] Examples of perfluoroalkyl groups include: methyl with 1 to 3 fluorine atoms, ethyl with 1 to 5 fluorine atoms, propyl with 1 to 7 fluorine atoms (e.g., n-propyl, isopropyl), butyl with 1 to 9 fluorine atoms (e.g., n-butyl, isobutyl, sec-butyl, tert-butyl), pentyl with 1 to 11 fluorine atoms (e.g., n-pentyl, tert-pentyl, neopentyl, isopentyl, sec-pentyl, 3-pentyl), hexyl with 1 to 13 fluorine atoms, heptyl with 1 to 15 fluorine atoms, octyl with 1 to 17 fluorine atoms, nonyl with 1 to 19 fluorine atoms, decyl with 1 to 21 fluorine atoms, undecyl with 1 to 23 fluorine atoms, dodecyl with 1 to 25 fluorine atoms, tridecyl with 1 to 27 fluorine atoms, tetradecyl with 1 to 29 fluorine atoms, and so on. Straight-chain or branched C1-C20 fluoroalkyl groups (e.g., C1-C10, C1-C4, C1-C3, preferably C1-C7, more preferably C1-C6 fluoroalkyl groups, such as pentadecyl with 1-31 fluorine atoms, hexadecyl with 1-33 fluorine atoms, heptadecanyl with 1-35 fluorine atoms, octadecyl with 1-37 fluorine atoms, nonadecanyl with 1-39 fluorine atoms, and eicosyl with 1-41 fluorine atoms); cyclic C3-C10 fluoroalkyl groups (e.g., C3-C6, C4-C6, C3-C5, C5-C6, C4-C8 fluoroalkyl groups, such as fluorocyclopropyl, fluorocyclobutyl, fluorocyclopentyl, fluorocyclohexyl, fluorocycloheptyl, fluorocyclooctyl, and fluoroadamantyl) (preferably perfluoroalkyl groups).

[0047] Examples of perfluoroalkyl groups include trifluoromethyl (CF3-), pentafluoroethyl (C2F5-), perfluoropropyl (e.g., CF3CF2CF2-, (CF3)2CF-), perfluorobutyl (e.g., CF3CF2CF2CF2-, (CF3)2CFCF2-, (CF3CF(CF3)CF2-, (CF3)3C-), perfluoropentyl (e.g., CF3CF2CF2CF2CF2-, (CF3)2CFCF2CF2-, CF3CF2CF(CF3)CF2-, CF3CF2CF2CF(CF3)-, CF3C(CF3)2CF2-), etc.

[0048] As fluoroalkyl groups, examples include perfluoroalkyl, monofluoromethyl, difluoromethyl, 2,2,2-trifluoroethyl (CF3CH2-), tetrafluoropropyl (e.g., HCF2CF2CH2-), hexafluoropropyl (e.g., (CF3)2CH-), octafluoropentyl (e.g., HCF2CF2CF2CF2CH2-), etc.

[0049] In this specification, unless otherwise specified, "alkoxy" can be a group represented by RO- [where R is an alkyl group]. Alkoxy groups include straight-chain, branched, and cyclic alkoxy groups. Alkoxy groups can be straight-chain or branched.

[0050] The number of carbon atoms in an alkoxy group can be, for example, 1–12, 1–6, 1–5, 1–4, 1–3, 6, 5, 4, 3, 2, or 1.

[0051] Examples of alkoxy groups include: linear or branched alkoxy groups such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentoxy, isopentoxy, neopentoxy, hexoxy, heptoxy, octoxy, nonoxy, and decoxy; and cyclic alkoxy groups such as cyclopropoxy, cyclobutoxy, cyclopentoxy, cyclohexoxy, cycloheptoxy, and cyclooctoxy.

[0052] Unless otherwise specified in this specification, "fluoroalkoxy" refers to an alkoxy group in which at least one hydrogen atom is replaced by a fluorine atom. "Fluoroalkoxy" can be either straight-chain or branched.

[0053] The number of carbon atoms in a fluoroalkoxy group can be, for example, 1–12, 1–6, 1–5, 1–4, 1–3, 6, 5, 4, 3, 2, or 1.

[0054] The number of fluorine atoms in a fluoroalkoxy group can be more than one (e.g., 1 to 3, 1 to 5, 1 to 9, 1 to 11, 1 to the maximum number that can be substituted).

[0055] Fluoroalkoxy groups include perfluoroalkoxy groups.

[0056] Perfluoroalkoxy groups are groups in which all hydrogen atoms of an alkoxy group are replaced by fluorine atoms.

[0057] Examples of perfluoroalkoxy groups include trifluoromethoxy (CF3O-), pentafluoroethoxy (C2F5O-), perfluoropropoxy (e.g., CF3CF2CF2O-, (CF3)2CFO-), perfluorobutoxy (e.g., CF3CF2CF2CF2O-, (CF3)2CFCF2O-, (CF3CF(CF3)CF2O-, (CF3)3CO-), perfluoropentoxy (e.g., CF3CF2CF2CF2CF2O-, (CF3)2CFCF2CF2O-, CF3CF2CF(CF3)CF2O-, CF3CF2CF2CF(CF3)O-, CF3C(CF3)2CF2O-), etc.

[0058] As fluoroalkoxy, specifically, examples include perfluoroalkoxy, monofluoromethoxy, difluoromethoxy, 2,2,2-trifluoroethoxy (CF3CH2O-), tetrafluoropropoxy (e.g., HCF2CF2CH2O-), hexafluoropropoxy (e.g., (CF3)2CHO-), octafluoropentoxy (e.g., HCF2CF2CF2CF2CH2O-), etc.

[0059] COMPOSITIONS One embodiment of the present invention is a composition containing a fluorinated monomer (M) and fluoride ions. In this composition, the content of fluoride ions is low, for example, 0.01 to 1000 ppm by mass relative to the composition. Therefore, the composition of the present invention can be effectively used as a supply source of the fluorinated monomer (M) when polymerizing the fluorinated monomer (M) to produce a fluoropolymer. For example, the composition can be directly supplied to the polymerization conditions to produce a fluoropolymer, or optionally supplied to the polymerization conditions after removing or reducing the fluoride ions contained in the composition. Furthermore, because the composition of the present invention has a low fluoride ion content, it can suppress corrosion of containers, piping, etc., that come into contact with the fluorinated monomer (M).

[0060] Fluorine-containing monomer (M) The fluorinated monomer (M) is at least one monomer selected from the compounds represented by formula (M1) (also referred to as "monomer (M1)" in this specification), the compounds represented by formula (M2) (also referred to as "monomer (M2)" in this specification), and the compounds represented by formula (M3) (also referred to as "monomer (M3)" in this specification). [In the formula, R] 1 and R 2 Each can be independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. [In the formula, R] 3 R 4 R 5 and R 6 Each can be independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. [In the formula, R] 7 R 8 R 9 and R 10 Each can be independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. The monomer (M) can be just one type or a combination of two or more types.

[0061] The manufacturing method of fluorinated monomer (M) is well known, and in this invention, the fluorinated monomer (M) can be manufactured using a well-known manufacturing method. For example, monomer (M3) can be manufactured using the methods described in Japanese Patent Application Publication No. 2005-002014, WO2020 / 166632, WO2020 / 230822, etc.

[0062] During storage, the fluorinated monomer (M) decomposes over time, generating fluoride ions, thus introducing fluoride ions into the fluorinated monomer. In this invention, the fluorinated monomer (M) containing fluoride ions is preferably generated in this manner. It can also be used when fluoride ions are generated during the manufacturing process of the fluorinated monomer (M), thereby producing a fluorinated monomer (M) containing fluoride ions. The fluorinated monomer (M) containing fluoride ions can also be obtained by adding fluoride ions to the fluorinated monomer (M).

[0063] Monomer (M1) R 1 and R 2 It can be independently a fluorine atom, a perfluorinated C1-C5 alkyl group, or a perfluorinated C1-C5 alkoxy group.

[0064] R 1 and R 2 It can be independently a fluorine atom, a perfluorinated C1-C4 alkyl group, or a perfluorinated C1-C4 alkoxy group.

[0065] R 1 and R 2 It can be independently a fluorine atom, a perfluorinated C1-C3 alkyl group, or a perfluorinated C1-C3 alkoxy group.

[0066] R 1 and R 2 It can be independently a fluorine atom, a perfluorinated C1-C2 alkyl group, or a perfluorinated C1-C2 alkoxy group.

[0067] R 1 and R 2 It can be a fluorine atom, trifluoromethyl, pentafluoroethyl or trifluoromethoxy, each independently.

[0068] R 1 and R 2 All of them can be fluorine atoms.

[0069] Preferred monomers (M1) include compounds represented by the following formula (M1-1) (also referred to as “monomer (M1-1)” in this specification). Monomer (M2) R 3 R 4 R 5 and R 6 It can be independently a fluorine atom, a perfluorinated C1-C5 alkyl group, or a perfluorinated C1-C5 alkoxy group.

[0070] R 3 R 4 R 5 and R 6 It can be independently a fluorine atom, a perfluorinated C1-C4 alkyl group, or a perfluorinated C1-C4 alkoxy group.

[0071] R 3 R 4 R 5 and R 6 It can be independently a fluorine atom, a perfluorinated C1-C3 alkyl group, or a perfluorinated C1-C3 alkoxy group.

[0072] R 3 R 4 R 5 and R 6 It can be a fluorine atom, trifluoromethyl, pentafluoroethyl, trifluoromethoxy, or pentafluoroethoxy, respectively.

[0073] R 3 R 4 R 5 and R 6 It can be a fluorine atom, trifluoromethyl, pentafluoroethyl or trifluoromethoxy, each independently.

[0074] R 3 R 4 R 5 and R 6 At least one group may be a fluorine atom, and the remaining groups may be perfluoroC1-C5 alkyl or perfluoroC1-C2 alkoxy groups. If there are multiple remaining groups, they may be the aforementioned groups independently.

[0075] R 3 R 4 R 5 and R 6 At least two groups may be fluorine atoms, and the remaining groups may be perfluoroC1-C5 alkyl or perfluoroC1-C2 alkoxy groups, wherein if there are multiple remaining groups, they are independently of the aforementioned groups. In this case, R is preferred. 3 and R 4 All are fluorine atoms, R 5 and R 6 They are, independently, perfluoroC1-C2 alkyl or perfluoroC1-C2 alkoxy.

[0076] R 3 R 4R 5 and R 6 It may have at least three groups that are fluorine atoms, and the remaining groups that are perfluoroC1-C5 alkyl or perfluoroC1-C2 alkoxy groups. In this case, R is preferred. 3 R 5 and R 6 All are fluorine atoms, R 4 It is a perfluoroC1-C5 alkyl or a perfluoroC1-C2 alkoxy group.

[0077] R 3 R 4 R 5 and R 6 It may have at least three groups that are fluorine atoms, and the remaining groups that are perfluoroC1-C2 alkoxy groups. In this case, R is preferred. 3 R 5 and R 6 All are fluorine atoms, R 4 It is a perfluoroC1-C2 alkoxy group.

[0078] R 3 R 4 R 5 and R 6 It can consist entirely of fluorine atoms.

[0079] Preferred monomers (M2) include compounds represented by formula (M2-1) and formula (M2-2) (also referred to as “monomer (M2-1)” and “monomer (M2-2)”, respectively, in this specification). Monomer (M3) R 7 R 8 R 9 and R 10 It can be independently a fluorine atom, a perfluorinated C1-C5 alkyl group, or a perfluorinated C1-C5 alkoxy group.

[0080] R 7 R 8 R 9 and R 10 It can be independently a fluorine atom, a perfluorinated C1-C4 alkyl group, or a perfluorinated C1-C4 alkoxy group.

[0081] R 7 R 8 R 9 and R 10 It can be independently a fluorine atom, a perfluorinated C1-C3 alkyl group, or a perfluorinated C1-C3 alkoxy group.

[0082] R 7 R8 R 9 and R 10 It can be a fluorine atom, trifluoromethyl, pentafluoroethyl, trifluoromethoxy, or pentafluoroethoxy, respectively.

[0083] R 7 R 8 R 9 and R 10 It can be a fluorine atom, trifluoromethyl, pentafluoroethyl or trifluoromethoxy, each independently.

[0084] R 7 R 8 R 9 and R 10 At least one group may be a fluorine atom, and the remaining groups may be perfluoroC1-C2 alkyl or perfluoroC1-C2 alkoxy groups, and when there are multiple remaining groups, they may be the aforementioned groups independently.

[0085] R 7 R 8 R 9 and R 10 At least two groups may be fluorine atoms, and the remaining groups may be perfluoroC1-C2 alkyl or perfluoroC1-C2 alkoxy groups. If there are multiple remaining groups, they may be the aforementioned groups independently.

[0086] R 7 R 8 R 9 and R 10 It may have at least 3 groups that are fluorine atoms and the remaining groups that are perfluoroC1-C2 alkyl or perfluoroC1-C2 alkoxy.

[0087] R 7 R 8 R 9 and R 10 It may have at least 3 groups that are fluorine atoms and the remaining groups that are perfluorinated C1-C2 alkyl groups.

[0088] R 7 R 8 R 9 and R 10 It can consist entirely of fluorine atoms.

[0089] As monomer (M3), the preferred compounds are those represented by the following formula (M3-1) (perfluoro(2-methylene-4-methyl-1,3-dioxolane, also referred to as "monomer (M3-1)" in this specification) or those represented by the following formula (M3-2) (perfluoro(2-methylene-1,3-dioxolane, also referred to as "monomer (M3-2)" in this specification). In the composition of the present invention, the content of the fluorinated monomer (M) relative to the mass of the composition can be, for example, 89.9 to 99.99% by mass, preferably 91 to 99.99% by mass, and more preferably 92 to 99.99% by mass.

[0090] Fluoride ion The compositions of the present invention contain fluoride ions in addition to a fluorinated monomer (M). Generally, the fluorinated monomer (M) decomposes during storage to generate fluoride ions. Fluoride ions can cause the following disadvantages: reduced thermal stability of polymers formed from the fluorinated monomer (M); corrosion of manufacturing equipment; increased costs of wastewater treatment; or the need for additional processes to remove or reduce fluoride ions. However, in the compositions of the present invention, the fluoride ion content is low. In the compositions of the present invention, the fluoride ion content relative to the mass of the composition is, for example, 0.01 to 1000 ppm by mass, preferably 0.01 to 800 ppm by mass, more preferably 0.01 to 600 ppm by mass, and even more preferably 50 to 600 ppm by mass.

[0091] Method for determining the content of fluoride ion The fluoride ion content in the fluorinated monomer (M) can be determined as follows.

[0092] Add 5 mL of pure water to 1 g of monomer (M) and stir at room temperature. Separate the resulting aqueous phase, and add 4 mL of total ionic strength adjustment buffer to 4 mL of the aqueous phase. Measure the fluoride ion concentration of the prepared solution using an ion meter. Considering the dilution rate, take 10 times the measured value as the fluoride ion (HF) concentration.

[0093] Compound represented by formula (C) The compositions of the present invention may contain a compound represented by formula (C) (also referred to as "compound (C)" in this specification). In the composition of the present invention, the content of compound (C) relative to the mass of the composition may be, for example, 0.01 to 10% by mass, preferably 0.01 to 8% by mass, and more preferably 0.01 to 6% by mass.

[0094] In addition to the fluorinated monomer (M) and fluoride ions, the composition of the present invention may also contain other components besides the compound (C). Examples of other components include impurities introduced during the manufacturing process of the fluorinated monomer (M). The proportion of these other components relative to the mass of the composition may be, for example, 0.001–8% by mass, 0.001–6% by mass, or 0.001–5% by mass.

[0095] The compositions of the present invention can be obtained, for example, by applying the purification method described later to a fluorinated monomer (M) incorporating fluoride ions. Alternatively, the compositions of the present invention can also be manufactured by incorporating fluoride ions into a fluorinated monomer (M) without fluoride ions.

[0096] Method for refining fluorine-containing monomer (M) Currently, there are no known methods for purifying fluorinated monomers (M) contaminated with fluoride ions. The purification method of the present invention is a method for purifying fluorinated monomers (M) contaminated with fluoride ions, comprising treating the fluorinated monomers (M) contaminated with fluoride ions using at least one method selected from activated carbon adsorption and washing, thereby reducing the amount of fluoride ions. By including this step, the purification method of the present invention can effectively reduce fluoride ions from fluorinated monomers (M).

[0097] In the process of reducing fluoride ions in a fluorinated monomer (M) that has been mixed with fluoride ions by activated carbon adsorption (activated carbon adsorption process), for example, by contacting the fluorinated monomer (M) mixed with fluoride ions with activated carbon, the activated carbon adsorbs the fluoride ions, and then the activated carbon is separated, thereby obtaining a fluorinated monomer (M) with reduced fluoride ion content.

[0098] The fluoride ion content in fluorinated monomers (M) mixed with fluoride ions can be 0.01–1000 ppm by mass, 0.01–800 ppm by mass, 0.01–600 ppm by mass, etc.

[0099] There are no particular limitations to activated carbon adsorption treatment methods, as long as the activated carbon comes into contact with the fluorinated monomer (M) mixed with fluoride ions. Activated carbon can be added to the fluorinated monomer (M) mixed with fluoride ions, or the fluorinated monomer (M) mixed with fluoride ions can be passed through a column packed with activated carbon, etc. After activated carbon adsorption, the activated carbon can be removed from the fluorinated monomer (M) using known solid-liquid separation methods.

[0100] Regarding the amount of activated carbon used in the activated carbon adsorption process, relative to 100g of fluorine-containing monomer (M) mixed with fluoride ions, it can be, for example, more than 1g, 1 to 20g, and preferably 1 to 10g.

[0101] The temperature for activated carbon adsorption treatment is, for example, -40 to 25°C, preferably -20 to 25°C.

[0102] The fluorinated monomer (M) purified using the purification method of the present invention may also contain compound (C). The content of the compound represented by formula (C) in the purified fluorinated monomer (M) may be 100 to 100,000 ppm by mass.

[0103] In the purification method of the present invention, a distillation step (distillation step) can be set up before the activated carbon adsorption step to distill the fluorinated monomer (M) mixed with fluoride ions. By distilling the fluorinated monomer (M) mixed with fluoride ions, high-boiling-point components such as oligomers of the fluorinated monomer (M) can be removed, which is advantageous.

[0104] Regarding the distillation treatment method, it can be carried out, for example, by applying a known distillation method to a fluorinated monomer (M) mixed with fluoride ions. The distillation temperature is, for example, 30–60°C, preferably 30–50°C. The distillation pressure is, for example, 50–500 hPa, preferably 200–500 hPa. The evaporated components generated by distillation are liquefied by cooling (for example, -78 to -20°C), and the resulting liquid is supplied to the activated carbon adsorption process.

[0105] In the process of reducing fluoride ions in a fluorinated monomer (M) by cleaning, for example, the fluorinated monomer (M) containing fluoride ions is contacted with a cleaning solution to extract the fluoride ions into the aqueous phase. The aqueous phase is then separated and removed to obtain a non-aqueous phase. This process yields a fluorinated monomer (M) with reduced fluoride ion content. The cleaning process can be performed once or repeatedly, preferably 1 to 3 times.

[0106] The cleaning solution used in the cleaning process can be water, KOH aqueous solution, K2CO3 aqueous solution, KHCO3 aqueous solution, NaOH aqueous solution, NaHCO3 aqueous solution, Na2CO3 aqueous solution, CsOH aqueous solution, Cs2CO3 aqueous solution, Ca(OH)2 aqueous solution, Ba(OH)2 aqueous solution, etc., preferably pure water, KOH aqueous solution, K2CO3 aqueous solution, KHCO3 aqueous solution, and more preferably pure water.

[0107] Regarding the amount of cleaning solution used in the cleaning process, relative to 100g of fluorinated monomer (M) mixed with fluoride ions, it can be, for example, 20g or more, 20 to 500g, and preferably 50 to 200g.

[0108] The cleaning temperature is, for example, 5–40°C, preferably 10–30°C.

[0109] During the cleaning process, the non-aqueous phase obtained from the cleaning treatment can be contacted with a desiccant (molecular sieve, silica gel, calcium chloride, calcium oxide, etc.) to remove residual moisture from the non-aqueous phase. The desiccant can be removed from the non-aqueous phase using known solid-liquid separation methods. The amount of desiccant used can be a suitable amount, relative to 100g of the non-aqueous phase, for example, 1-20g.

[0110] Method for producing fluorine-containing monomer (M) further reduced in fluoride ion content The manufacturing method of the present invention is a method for manufacturing a fluorinated monomer (M) with a further reduced fluoride ion content (e.g., a fluorinated monomer (M) with a fluoride ion content of 0.01 to 1000 ppm by mass) from a fluorinated monomer (M) mixed with fluoride ions, including a step of treating the fluorinated monomer (M) mixed with fluoride ions using at least one method selected from activated carbon adsorption and cleaning to reduce fluoride ions (the step of reducing fluoride ions).

[0111] The process of reducing fluoride ions can be carried out, for example, by applying the above-described purification method for fluorinated monomers (M) to fluorinated monomers (M) that have been contaminated with fluoride ions. Therefore, the process of reducing fluoride ions can be implemented using the above-described purification method for fluorinated monomers (M) within feasible limits.

[0112] The fluoride ion content in the fluorinated monomer (M) manufactured by the manufacturing method of the present invention is, for example, 0.01 to 1000 ppm by mass, preferably 0.01 to 800 ppm by mass, and more preferably 0.01 to 600 ppm by mass.

[0113] The implementation methods have been described above, but it is understood that various changes can be made to the methods and details as long as they do not depart from the essential points and scope of the claimed protection.

[0114] Example Hereinafter, an embodiment of the present invention will be described in more detail using examples, etc., but the present invention is not limited to these.

[0115] The fluorinated monomers used in the following examples are as follows.

[0116] (Fluorine-containing monomers) Perfluorinated (2-methylene-4-methyl-1,3-dioxolane (monomer (M3-1))) (Adsorbent: Activated carbon) Shirasagi A (Osaka Gas Chemical Co., Ltd.) (Adsorbent: Molecular sieve) Molecular Sieves 4A 1 / 16 (Fujifilm Wako Pure Chemical Industries, Ltd.) (Adsorbent: silica gel) Wakogel (trademark) C-300 (Fujifilm and Koko Pure Chemical Industries Co., Ltd.) (Adsorbent: Alumina) Activated alumina (Fujifilm and Wako Pure Chemical Industries, Ltd.) (Method for determining the fluoride ion content of fluorine-containing monomers) The fluoride ion content in fluorinated monomers was determined as described below.

[0117] Add 5 mL of pure water to 1 g of fluoride monomer and stir at room temperature. Separate the resulting aqueous phase, and add 4 mL of total ionic strength adjustment buffer to 4 mL of the aqueous phase. Measure the fluoride ion concentration of the prepared solution using an ion meter. Considering the dilution rate, take 10 times the measured value as the fluoride ion (HF) content.

[0118] (Distillation process) The distillation process is carried out as described below.

[0119] A fluorinated monomer was added to a glass flask and distilled at 40°C and 400 hPa. The mixture was collected using acetone cooled by dry ice at -78°C to obtain the fluorinated monomer.

[0120] (Activated carbon adsorption treatment) Add 0.5g of activated carbon to 10g of fluorinated monomer and shake at 0℃ for 10 minutes. Filter the fluorinated monomer using an injection filter to separate and remove the activated carbon, obtaining the purified fluorinated monomer.

[0121] (Cleaning process) The cleaning solution used is pure water or a 5% (w / v) KOH aqueous solution. 10g of cleaning solution is added to 10g of fluorinated monomer and stirred. The resulting aqueous phase is removed, yielding a non-aqueous phase. 10g of fresh cleaning solution is added to the non-aqueous phase, and the same process is repeated to obtain another non-aqueous phase. This process of adding cleaning solution and stirring (washing) is repeated three times. 0.5g of molecular sieve is added to the resulting non-aqueous phase and stirred to reduce residual cleaning solution components. The resulting non-aqueous phase is filtered using an injection filter to separate and remove the molecular sieve, yielding the purified fluorinated monomer.

[0122] Manufacturing Example 1 (Preparation of Monomer (M3-1)) The monomer (M3-1) was prepared using a known method. The obtained monomer (M3-1) had a fluoride ion content of 3000 ppm by mass.

[0123] Example 1 (Activated Carbon Adsorption Treatment) The monomer (M3-1) obtained in Manufacturing Example 1 was subjected to activated carbon adsorption treatment. The fluoride ion content of the obtained monomer (M3-1) was 500 ppm by mass. The fluoride ion content was reduced from 3000 ppm by mass to 500 ppm by mass.

[0124] Example 2 (Distillation and Activated Carbon Adsorption Treatment) The monomer (M3-1) obtained in Manufacturing Example 1 was subjected to distillation followed by activated carbon adsorption for purification. The fluoride ion content of the obtained monomer (M3-1) was 80 ppm by mass. The fluoride ion content was reduced from 3000 ppm by mass to 80 ppm by mass.

[0125] Example 3 (Cleaning treatment using water) The monomer (M3-1) obtained in Manufacturing Example 1 was cleaned with pure water. The fluoride ion content of the obtained monomer (M3-1) was 340 ppm by mass. The fluoride ion content was reduced from 3000 ppm by mass to 340 ppm by mass.

[0126] Example 4 (Cleaning treatment using 5% KOH aqueous solution) The monomer (M3-1) obtained in Manufacturing Example 1 was cleaned using a 5% KOH aqueous solution. The fluoride ion content of the obtained monomer (M3-1) was 290 ppm by mass. The fluoride ion content was reduced from 3000 ppm by mass to 290 ppm by mass.

[0127] Comparative Examples 1–3 (Distillation and Adsorption Treatments) Except for changing the adsorbent from activated carbon to molecular sieves, silica gel, or alumina, the monomer (M3-1) obtained in Manufacturing Example 1 was purified in the same manner as in Example 2. The fluoride ion contents of the obtained monomer (M3-1) were 2780 ppm by mass, 1340 ppm by mass, and 1900 ppm by mass, respectively.

[0128] The results of Examples 1-4 and Comparative Examples 1-3 are shown in Table 1. In Examples 1-4, the content of fluoride ions mixed in the fluorinated monomer was significantly reduced.

[0129] [Table 1]

Claims

1. A composition containing a fluorinated monomer (M) and fluoride ions, characterized in that, The fluoride ion content relative to the composition is 0.01 to 1000 ppm by mass. The fluorinated monomer (M) is at least one monomer selected from the compounds shown in formula (M1), formula (M2), and formula (M3). In the formula, R 1 and R 2 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. In the formula, R 3 R 4 R 5 and R 6 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. In the formula, R 7 R 8 R 9 and R 10 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group.

2. The composition according to claim 1, characterized in that, The fluorinated monomer (M) is at least one compound selected from the following formulas: (M1-1), (M2-1), (M2-2), (M3-1), and (M3-2). 。 3. The composition according to claim 1 or 2, characterized in that, The fluorinated monomer (M) is a compound represented by the following formula (M3-1). 。 4. The composition according to claim 3, characterized in that, It also contains the compound shown in formula (C) below. 。 5. The composition according to claim 4, characterized in that, The content of the compound represented by formula (C) is 0.01 to 10% by mass relative to the composition.

6. The composition according to any one of claims 1 to 5, characterized in that, The fluoride ion content is 50 to 600 ppm by mass relative to the composition.

7. The composition according to claim 1, characterized in that, The fluorinated monomer (M) is a compound represented by the following formula (M3-1). The fluoride ion content is 50 to 600 ppm by mass relative to the composition.

8. A method for manufacturing a fluorinated monomer (M), comprising a method for manufacturing a fluorinated monomer (M) with a further reduced fluoride ion content from a fluorinated monomer (M) mixed with fluoride ions, characterized in that, The process includes treating a fluorinated monomer (M) contaminated with fluoride ions using at least one method selected from activated carbon adsorption and cleaning, thereby reducing the amount of fluoride ions. The fluoride ion content in the manufactured fluorinated monomer (M) ranges from 0.01 to 1000 ppm by mass. The fluorinated monomer (M) is at least one monomer selected from the compounds shown in formula (M1), formula (M2), and formula (M3). In the formula, R 1 and R 2 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. In the formula, R 3 R 4 R 5 and R 6 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. In the formula, R 7 R 8 R 9 and R 10 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group.

9. The manufacturing method as described in claim 8, characterized in that, The method for treating fluorinated monomers (M) mixed with fluoride ions is activated carbon adsorption.

10. The manufacturing method as described in claim 9, characterized in that, The activated carbon adsorption treatment is a method of distilling a fluorine-containing monomer (M) mixed with fluoride ions, and then subjecting the distilled fluorine-containing monomer (M) to activated carbon adsorption treatment.

11. The manufacturing method as described in claim 8, characterized in that, The cleaning process involves using water or an alkaline solution.

12. The manufacturing method according to any one of claims 8 to 11, characterized in that, The fluorinated monomer (M) is at least one compound selected from the following formulas: (M1-1), (M2-1), (M2-2), (M3-1), and (M3-2). 。 13. The manufacturing method according to any one of claims 8 to 11, characterized in that, The fluorinated monomer (M) is a compound represented by the following formula (M3-1). 。 14. The manufacturing method according to any one of claims 8 to 13, characterized in that, The fluoride ion content in the manufactured fluorinated monomer (M) is 50 to 600 ppm by mass.

15. The manufacturing method as described in claim 8, characterized in that, The fluorinated monomer (M) is a compound represented by the following formula (M3-1). The methods for treating fluorinated monomers (M) that have been mixed with fluoride ions are as follows: (1), (2) or (3). (1) A method for activated carbon adsorption treatment of fluorine-containing monomers (M) mixed with fluoride ions; (2) A method of distilling a fluorine-containing monomer (M) mixed with fluoride ions, and then subjecting the distilled fluorine-containing monomer (M) to activated carbon adsorption treatment. (3) A method of cleaning fluorine-containing monomers (M) mixed with fluoride ions using water or alkaline aqueous solutions. The fluoride ion content in the manufactured fluorinated monomer (M) is 50 to 600 ppm by mass.

16. A method for purifying a fluorinated monomer (M) mixed with fluoride ions, characterized in that, The process includes treating a fluorinated monomer (M) contaminated with fluoride ions using at least one method selected from activated carbon adsorption and cleaning, thereby reducing the amount of fluoride ions. The fluorinated monomer (M) is at least one monomer selected from the compounds shown in formula (M1), formula (M2), and formula (M3). In the formula, R 1 and R 2 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. In the formula, R 3 R 4 R 5 and R 6 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group. In the formula, R 7 R 8 R 9 and R 10 Each is independently a fluorine atom, a perfluoroalkyl group, or a perfluoroalkoxy group.

17. The refining method as described in claim 16, characterized in that, The fluoride ion content in the refined fluorinated monomer (M) is 0.01 to 1000 ppm by mass.

18. The refining method as described in claim 16, characterized in that, The fluoride ion content in the refined fluorinated monomer (M) is 50-600 ppm by mass.

19. The refining method as described in claim 16, characterized in that, The method for treating fluorinated monomers (M) mixed with fluoride ions is activated carbon adsorption.

20. The refining method as described in claim 19, characterized in that, The activated carbon adsorption treatment is a method of distilling a fluorine-containing monomer (M) mixed with fluoride ions, and then subjecting the distilled fluorine-containing monomer (M) to activated carbon adsorption treatment.

21. The refining method as described in claim 16, characterized in that, The cleaning process involves using water or an alkaline solution.

22. The refining method according to any one of claims 16 to 21, characterized in that, The fluorinated monomer (M) is at least one compound selected from the following formulas: (M1-1), (M2-1), (M2-2), (M3-1), and (M3-2). 。 23. The refining method according to any one of claims 16 to 21, characterized in that, The fluorinated monomer (M) is a compound represented by the following formula (M3-1). 。 24. The refining method as described in claim 23, characterized in that, The fluorinated monomer (M) incorporating fluoride ions is a fluorinated monomer incorporating fluoride ions and a compound represented by the following formula (C). 。 25. The refining method as described in claim 24, characterized in that, The content of the compound represented by formula (C) in the purified fluorinated monomer (M) is 100 to 100,000 ppm by mass.

26. The refining method as described in claim 16, characterized in that, The fluorinated monomer (M) is a compound represented by the following formula (M3-1). The fluorinated monomer (M) incorporating fluoride ions is a fluorinated monomer incorporating fluoride ions and a compound represented by the following formula (C). The methods for treating fluorinated monomers (M) that have been mixed with fluoride ions are as follows: (1), (2) or (3). (1) A method for activated carbon adsorption treatment of fluorine-containing monomers (M) mixed with fluoride ions; (2) A method of distilling a fluorine-containing monomer (M) mixed with fluoride ions, and then subjecting the distilled fluorine-containing monomer (M) to activated carbon adsorption treatment. (3) A method of cleaning fluorine-containing monomers (M) mixed with fluoride ions using water or alkaline aqueous solutions. The fluoride ion content in the manufactured fluorinated monomer (M) is 50–600 ppm by mass. The content of the compound represented by formula (C) in the purified fluorinated monomer (M) is 100 to 100,000 ppm by mass.

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