Solid matter, composition, and molded body

Abstract

The present invention addresses the problem of providing: a solid matter having excellent crushability; a composition including the solid matter; a molded body obtained by molding the solid matter; and a molded body obtained by molding the composition.　A solid matter according to the present invention comprises: a copolymer including a unit based on tetrafluoroethylene, a unit based on ethylene, and a unit based on a specific compound selected from the group consisting of compounds represented by formula (1) CX1 2=CX2(CF2)mF and compounds represented by formula (2) CF2=CF-O-(CF2)nF; said specific compound; and a solvent. The solvent includes a fluorine-containing solvent including a hydrogen atom and a fluorine atom and optionally having an ether bond. The fluorine-containing solvent contains a hydrofluorocarbon having a group represented by formula (3) CF3(CF2)p-*. The proportion of the total contained amount of the hydrofluorocarbon and the specific compound with respect to the total contained amount of the solvent and the specific compound is 90.0 mass% or less.

Description

Solids, compositions and molded bodies

[0001] The present invention relates to solids, compositions and shaped bodies.

[0002] Ethylene / tetrafluoroethylene copolymer (hereinafter also referred to as "ETFE") is excellent in heat resistance, weather resistance, electrical insulation, non-stickiness, water and oil repellency, etc., and is characterized by high moldability and mechanical strength among fluororesins. Therefore, a variety of molded articles such as electric wire coverings, tubes, sheets, films, filaments, pump casings, joints, packings, linings, and coatings are produced by melt molding methods such as extrusion molding, blow molding, injection molding, and rotational molding. For example, Patent Document 1 discloses a method for recovering a fluorinated ether, including a step of producing a wet copolymer by suspension polymerization, solution polymerization, or bulk polymerization in the presence of a predetermined fluorinated ether, a step of heating the wet copolymer in a vessel to vaporize and discharge a vaporized substance containing the fluorinated ether, and a step of transferring the vaporized substance to a cooling means and cooling it.

[0003] Patent No. 5569660

[0004] When ETFE is used as a constituent material of a molded body, it is required to have various excellent properties.The present inventors have produced ETFE with reference to the method described in Patent Document 1, and evaluated the solid material containing the produced ETFE, and found that there is room for improvement in the crushability of the solid material.

[0005] Therefore, an object of the present invention is to provide a solid material having excellent crushability. Another object of the present invention is to provide a composition containing the solid material, a molded body obtained by molding the solid material, and a molded body obtained by molding the composition.

[0006] As a result of intensive research into the above-mentioned problems, the present inventors have found that a solid material containing a copolymer containing units based on tetrafluoroethylene, units based on ethylene, and units based on a specific compound described below, the specific compound, and a solvent that is a compound different from the specific compound, wherein the solvent contains a fluorine-containing solvent containing hydrogen atoms and fluorine atoms and which may have an ether bond, and the fluorine-containing solvent contains a hydrofluorocarbon having a group represented by formula (3) described below, and the ratio of the total content of the hydrofluorocarbon and the specific compound to the total content of the solvent and the specific compound is 90.0 mass% or less, is a solid material with excellent grindability, which led to the present invention.

[0007] That is, the inventors have found that the above-mentioned problems can be solved by the following configuration. [1] A solid product comprising a copolymer containing units based on tetrafluoroethylene, units based on ethylene, and units based on a specific compound selected from the group consisting of compounds represented by the below-described formula (1) and compounds represented by the below-described formula (2), the specific compound, and a solvent that is a compound different from the specific compound, wherein the solvent comprises a fluorine-containing solvent containing hydrogen atoms and fluorine atoms and optionally having an ether bond, and the fluorine-containing solvent comprises a hydrofluorocarbon having a group represented by the below-described formula (3), and the ratio of the total content of the hydrofluorocarbon and the specific compound to the total content of the solvent and the specific compound is 90.0 mass % or less. [2] The solid product according to [1], wherein the content of the units based on tetrafluoroethylene is 48.00 to 64.90 mol % of all units contained in the copolymer. [3] The solid material according to [1] or [2], wherein the content of the units based on ethylene is 35.00 to 51.90 mol % based on all units contained in the copolymer. [4] The solid material according to any one of [1] to [3], wherein the content of the units based on the specific compound in the copolymer is 0.10 to 5.00 mol % based on all units contained in the copolymer. [5] The solid material according to any one of [1] to [4], wherein the fluorine-containing solvent further contains a hydrofluoroether. [6] The solid material according to [5], wherein the hydrofluoroether contains a compound represented by formula (4) described below. [7] The solid material according to any one of [1] to [6], wherein the solvent further contains water. [8] The solid material according to any one of [1] to [7], wherein the content of the solvent is 0.01 to 2 mass % based on the total mass of the solid material. [9] The solid material according to any one of [1] to [8], wherein the content of the hydrofluorocarbon is 0.001 to 1.5% by mass relative to the total mass of the solid material.

[10] A composition comprising the solid material according to any one of [1] to [9] and at least one component selected from the group consisting of a resin other than the copolymer, a heat stabilizer, an antioxidant, a colorant, an ultraviolet absorber, a filler, a crosslinking agent, a crosslinking aid, and an organic peroxide.

[11] A molded article obtained by molding the solid material according to any one of [1] to [9].

[12] A molded article obtained by molding the composition according to

[10] .

[0008] According to the present invention, a solid material having excellent crushability can be provided. Furthermore, according to the present invention, a composition containing the solid material, a molded body obtained by molding the solid material, and a molded body obtained by molding the composition can be provided.

[0009] The meanings of terms used in this specification are as follows. A numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the upper and lower limits. In the numerical ranges described in stages in this specification, the upper or lower limit described in a certain numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in the numerical ranges described in this specification, the upper or lower limit described in a certain numerical range may be replaced with a value shown in the Examples. In this specification, each component may be used alone or in combination with two or more substances corresponding to the component. Here, when two or more substances are used in combination for each component, the content of that component refers to the total content of the substances used in combination, unless otherwise specified. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment.

[0010] "Unit" is a general term for the atomic group derived from one molecule of the above-mentioned monomer, which is directly formed by polymerizing the monomer, and the atomic group obtained by chemically converting a part of the above-mentioned atomic group.In the following, in some cases, the unit derived from each monomer will be described by adding "unit" to the name of the monomer.A "TFE unit" is a unit based on tetrafluoroethylene of the copolymer, and an "E unit" is a unit based on ethylene of the copolymer.In addition, an "A unit" is a unit based on a specific compound described below.A "solvent" means a substance that is liquid at 25°C and 1013hPa.

[0011] [Solid Product] The solid product of the present invention (hereinafter also referred to as "the solid product") comprises a copolymer containing TFE units, E units, and A units based on a specific compound described below, and further comprises the specific compound and a solvent which is a compound different from the specific compound. The solid product contains at least a hydrofluorocarbon having a group represented by formula (3) described below as the solvent. The solid product is also characterized in that the ratio of the total content of the hydrofluorocarbon and the specific compound to the total content of the solvent and the specific compound (hereinafter also referred to as "ratio S") is 90.0 mass% or less.

[0012] The details of why this solid is excellent in pulverizability have not yet been clarified, but it is considered that in this solid, among the components used in the manufacture of the copolymer or solid, the total content of specific compound and the compound represented by formula (3) described below is below a predetermined value.These specific compound and the compound represented by formula (3) described below have relatively high lipophilicity, so it is presumed that when they are contained in solid, they easily make the copolymer comprising TFE unit, E unit and A unit swell, and as a result, the hardness of the solid increases.In this solid, the total content of specific compound and the compound represented by formula (3) described below is below a predetermined value, so it is presumed that the copolymer is difficult to swell, and the hardness of the solid is suitable for pulverization.Here, the fact that the solid is excellent in pulverizability means that by pulverizing the solid, it is easy to produce a powder with narrow particle size distribution and uniform particle size.

[0013] Each component contained in the solid material will be explained below.

[0014] [Copolymer] The present solid contains a copolymer containing E units, TFE units, and A units. Hereinafter, unless otherwise specified, the mere expression "copolymer" means a copolymer containing E units, TFE units, and A units.

[0015] The copolymer contains TFE units based on tetrafluoroethylene, E units based on ethylene, and A units based on a specific compound selected from the group consisting of compounds represented by formula (1) and compounds represented by formula (2).

[0016] CX １ ２ =CX ２ (CF ２ ) ｍ F Formula (1) CF ２ =CF-O-(CF ２ ) ｎ F Formula (2) In Formula (1), X １ and X ２ each independently represents a hydrogen atom or a fluorine atom, and m represents an integer of 1 to 6. In formula (2), n represents an integer of 1 to 6.

[0017] In the compound represented by formula (1), X １ and X ２ From the viewpoint of polymerizability, m is preferably a hydrogen atom. m is preferably an integer of 2 to 6, more preferably an integer of 2 to 4, and even more preferably 4.

[0018] The compound represented by formula (1) includes CH ２ =CH(CF ２ ) ２ F, CH ２ =CH(CF ２ ) ４ F, CH ２ =CH(CF ２ ) ６ F or CH ２ =CF(CF ２ ) ４ F is preferred, CH ２ =CH(CF ２ ) ４F (hereinafter also referred to as "PFBE") is more preferred.

[0019] Specific examples of the compound represented by formula (2) include CF ２ =CF-O-(CF ２ ) F, CF ２ =CF-O-(CF ２ ) ２ F, CF ２ =CF-O-(CF ２ ) ３ F, CF ２ =CF-O-(CF ２ ) ４ F, CF ２ =CF-O-(CF ２ ) ５ F and CF ２ =CF-O-(CF ２ ) ６ Among them, CF corresponding to the compound where n is 3 ２ =CF-O-(CF ２ ) ３ F is preferred.

[0020] The copolymer may contain, as A units, either units based on a compound represented by formula (1) (hereinafter also referred to as "A1 units") or units based on a compound represented by formula (2) (hereinafter also referred to as "A2 units"), or may contain both A1 units and A2 units. In other words, when the copolymer contains both A1 units and A2 units, the "content of A units" means the sum of the content of A1 units and the content of A2 units.

[0021] As the copolymer, a copolymer containing TFE units, E units and A1 units, or a copolymer containing TFE units, E units and A2 units is preferred, and from the viewpoint of excellent long-term folding endurance, a copolymer containing E units, TFE units and A1 units is more preferred.

[0022] The content of TFE units is preferably 45.00 to 69.99 mol%, more preferably 48.00 to 64.90 mol%, and even more preferably 50.00 to 64.50 mol%, based on the total units contained in the copolymer. If the content is equal to or greater than the lower limit, the chemical resistance and heat resistance of the molded article during long-term use will be superior, and if the content is equal to or less than the upper limit, the mechanical properties of the molded article will be superior.

[0023] The content of E units is preferably 30.00 to 54.99 mol%, more preferably 35.00 to 51.90 mol%, and even more preferably 35.00 to 49.50 mol%, based on the total units contained in the copolymer. If the content is equal to or greater than the lower limit, the mechanical properties of the molded article will be superior, and if the content is equal to or less than the upper limit, the heat resistance and weather resistance during long-term outdoor use of the molded article will be superior.

[0024] The content of A units is preferably 0.01 to 10.00 mol %, more preferably 0.10 to 5.00 mol %, and even more preferably 0.50 to 4.00 mol %, based on the total units contained in the copolymer. If the content is equal to or greater than the lower limit, a molded article having excellent abrasion resistance can be formed, and if the content is equal to or less than the upper limit, a molded article having excellent dimensional stability can be formed.

[0025] In the copolymer, the total content of TFE units and E units is preferably 90.00 to 99.99 mol%, more preferably 95.00 to 99.90 mol%, and even more preferably 96.00 to 99.50 mol%, based on all units contained in the copolymer.

[0026] The copolymer may contain units based on other monomers other than tetrafluoroethylene, ethylene, and the specific compound. Specific examples of other monomers include fluoroolefins (e.g., vinyl fluoride, vinylidene fluoride, trifluoroethylene, hexafluoroisobutylene, etc., excluding the specific compound), CF ２ =CFORf １ SO ２ Y １ (However, Rf １ is a perfluoroalkylene group having 1 to 10 carbon atoms which may contain an oxygen atom between the carbon atoms, and Y １ is a halogen atom or a hydroxyl group.), CF ２ =CFORf２ CO ２ Y ２ (However, Rf ２ is a perfluoroalkylene group having 1 to 10 carbon atoms which may contain an oxygen atom between the carbon atoms, and Y ２ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.), CF ２ =CF(CF ２ ) pOCF=CF ２ (where p is 1 or 2), fluorine-containing monomers having a ring structure (for example, perfluoro(2,2-dimethyl-1,3-dioxole), 2,2,4-trifluoro-5-trifluoromethoxy-1,3-dioxole, perfluoro(2-methylene-4-methyl-1,3-dioxolane)), itaconic acid, itaconic anhydride, citraconic acid, and citraconic anhydride. Among these, itaconic acid, itaconic anhydride, citraconic acid, and citraconic anhydride are preferred, and itaconic anhydride is more preferred.

[0027] When the copolymer contains units based on other monomers, the content of the units based on other monomers is preferably 0.01 to 2.00 mol %, more preferably 0.10 to 1.00 mol %, based on all units contained in the copolymer.

[0028] As copolymer, the embodiment that comprises TFE unit, E unit and A unit is preferred, and the embodiment that comprises TFE unit, E unit and A1 unit is more preferred.In view of the fact that the crushability of this solid is more excellent, the content of copolymer in this solid is preferably 99% by mass or more, more preferably 99.5% by mass or more, and even more preferably 99.8% by mass or more.In view of the fact that the bending resistance of molded body is more excellent, the content of copolymer in this solid is preferably 99.99% by mass or less, more preferably 99.95% by mass or less.

[0029] <Melt Flow Rate> The melt flow rate (hereinafter also referred to as "MFR") of the copolymer is preferably 1 to 60 g / 10 min, more preferably 2 to 50 g / 10 min. When the MFR of the copolymer is equal to or greater than the above-mentioned lower limit, a molded article with excellent fluidity can be formed during melt molding. Furthermore, when the MFR of the copolymer is equal to or less than the above-mentioned upper limit, a molded article with excellent abrasion resistance at high temperatures can be formed. A specific example of a method for adjusting the MFR of the copolymer within the above range is to adjust the molecular weight of the copolymer. The higher the molecular weight of the copolymer, the smaller the MFR. The MFR of the copolymer can be obtained by measuring the mass of a solid material flowing from an orifice with a diameter of 2 mm and a length of 8 mm over 10 minutes at a temperature of 297°C and a load of 49 N in accordance with ASTM D3159. The copolymer is the main component of the solid material, and components other than the copolymer have little effect on the MFR measurement. Therefore, the measured MFR obtained by measuring the solid material can be considered the MFR of the copolymer.

[0030] <Melting Point> The melting point of the copolymer is preferably 210°C or higher, more preferably 215°C or higher, and even more preferably 220°C or higher, in order to provide a molded article with superior mechanical strength when used at high temperatures. The upper limit of the melting point of the copolymer is preferably 290°C or lower, more preferably 280°C or lower, and particularly preferably 270°C or lower, in order to provide superior moldability of the solid product. Specific examples of methods for adjusting the melting point of the copolymer within the above range include lowering the polymerization temperature during copolymer production and adjusting the content of A units in the copolymer. The melting point of the copolymer is the temperature corresponding to the endothermic peak detected when a solid product is heated at a rate of 10°C / min in an air atmosphere using a differential scanning calorimeter. As with MFR, the measured melting point obtained by measuring a solid product can be considered to be the melting point of the copolymer.

[0031] [Specific Compound] The present solid contains a specific compound. Specific examples and preferred embodiments of the specific compound are the same as those of the specific compound from which the A unit is derived.

[0032] The specific compound contained in the present solid may be both the compound represented by formula (1) and the compound represented by formula (2), but one of the compound represented by formula (1) and the compound represented by formula (2) is preferred, and the compound represented by formula (1) is more preferred.In addition, the specific compound from which the A unit contained in the copolymer is derived and the specific compound contained in the present solid are preferably the same.For example, when the copolymer contains PFBE units as A units, the present solid preferably contains PFBE as the specific compound.

[0033] The content of the specific compound contained in the solid material is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, and even more preferably 0.03% by mass or less, from the viewpoint of better crushability of the solid material, and is preferably 0.0001% by mass or more, more preferably 0.002% by mass or more, from the viewpoint of better bending resistance of the molded product.

[0034] The contents of the specific compounds and the solvents (excluding water) described below contained in the solid material can be measured by analyzing the volatile components when the solid material is heated to 240°C using a headspace GC / MS device.

[0035] [Solvent] The present solid material contains a solvent. However, the solvent contained in the present solid material is a compound different from the specific compound. Specific examples of the solvent contained in the present solid material include water and organic solvents such as hydrofluorocarbons, hydrofluoroethers, perfluorocarbons, alcohols, and hydrocarbons.

[0036] In this solid, the solvent includes a fluorine-containing solvent containing hydrogen atoms and fluorine atoms, which may have an ether bond (hereinafter also referred to as "solvent F"). Solvent F also includes a hydrofluorocarbon having a group represented by formula (3) (hereinafter also referred to as "solvent F3"). CF ３ (CF ２ ) ｐ -* (3) In formula (3), p represents an integer of 1 or more, and * represents a bonding site with an adjacent atom. p is preferably an integer of 1 to 5, and more preferably an integer of 1 to 3.

[0037] Solvent F3 is preferably a compound represented by formula (3a): CF ３ (CF ２ ) ｐ -R (3a) In formula (3a), R represents a hydrogen atom, or a fluoroalkyl or alkyl group having 1 to 6 carbon atoms. However, in the fluoroalkyl or alkyl group represented by R, CF ３ (CF ２ ) ｐ The carbon atom bonded to the - group is bonded to at least one hydrogen atom. The definition and preferred embodiments of p in formula (3a) are the same as those of p in formula (3). R is preferably a hydrogen atom or a fluoroalkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom. The number of carbon atoms in the compound represented by formula (3a) is preferably 3 to 8, more preferably 4 to 7.

[0038] Specific examples of solvent F3 include CF ３ CFHCF ２ CF ２ CF ３ , C.F. ３ (CF ２ ) ４ H, C.F. ３ CF ２ CFHCF ２ CF ３ , C.F. ３ CFHCFHCF ２ CF ３ , C.F. ２ HCFHCF ２ CF ２ CF ３ , C.F. ３ (CF ２ ) ５ H, C.F. ３ CH (CF ３ )CF ２ CF ２ CF ３ , C.F. ３ CF (CF ３ ) CFHCF ２ CF ３ , C.F. ３ CH (CF ３ ) CFHCF ２ CF ３, C.F. ３ CF ２ CH ２ CH ３ , and CF ３ (CF ２ ) ３ CH ２ CH ３ Among them, CF ３ (CF ２ ) ５ H is preferred.

[0039] The content of solvent F3 is preferably 0.001 to 2.0% by mass, more preferably 0.001 to 1.5% by mass, and even more preferably 0.001 to 1.2% by mass, based on the total mass of the solid material. If the content is equal to or less than the upper limit, the crushability of the solid material is superior, and if the content is equal to or more than the lower limit, the particle size of the solid material becomes uniform, resulting in superior handleability.

[0040] In this solid, it is preferable that solvent F further contains a hydrofluoroether. As the hydrofluoroether, a fluorine-containing solvent having an ether bond and containing a hydrogen atom and a fluorine atom can be used. In particular, it is preferable that the hydrofluoroether contains a compound represented by formula (4) (hereinafter also referred to as "solvent F4"). R １ -O-R ２ (4) In formula (4), R １ represents a fluoroalkyl group having 2 to 6 carbon atoms, and R ２ represents a fluoroalkyl group or an alkyl group having 1 to 4 carbon atoms, and R １ and R ２ The total number of carbon atoms in the above groups is not more than 8. When the solid contains a hydrofluoroether (more preferably solvent F4), the bulk density of the solid increases, resulting in better transportability in the production line.

[0041] R in formula (4) １ As R in formula (4), a fluoroalkyl group having 2 to 4 carbon atoms is preferable, and a fluoroalkyl group having 2 or 3 carbon atoms is more preferable. ２As R in formula (4), a fluoroalkyl group or alkyl group having 1 to 3 carbon atoms is preferable, a fluoroalkyl group or alkyl group having 1 or 2 carbon atoms is more preferable, and a fluoroalkyl group having 2 carbon atoms is even more preferable. １ and R ２ The total number of carbon atoms is preferably 3 to 7, more preferably 4 to 6, and even more preferably 4 or 5.

[0042] Specific examples of solvent F4 include CF ３ CH ２ OCF ２ CF ２ H, C.F. ３ (CF ３ ) CFCF ２ OCH ３ , C.F. ３ (CF ２ ) ３ OCH ３ , C.F. ３ (CF ２ ) ３ O.C. ２ H ５、 CF ３ (CF ２ ) ２ C ３ F ７ OCH ３ , and (CF ３ ) ２ CFOCH ３ CF ３ CH ２ OCF ２ CF ２ H is preferred.

[0043] When the solid contains solvent F4, the content of solvent F4 is preferably 0.0001 to 0.4 mass%, and more preferably 0.0001 to 0.3 mass%, relative to the total mass of the solid. When the solid contains a hydrofluoroether, the content of the hydrofluoroether is preferably 0.0001 to 0.5 mass%, and more preferably 0.0001 to 0.4 mass%, relative to the total mass of the solid.

[0044] The solid may contain a fluorine-containing solvent that contains hydrogen atoms and fluorine atoms and is not included in either solvent F3 or hydrofluoroether (hereinafter also referred to as "other fluorine-containing solvent"). Specific examples of other fluorine-containing solvents include 1,1,2,2-tetrafluorocyclobutane, CF ３ CFHCFHCF ３ , C.F. ３ CF (CF ３ ) CFHCFHCF ３ , C.F. ３ CH ２ CF ２ CH ３ (HFC-365mfc), CF ２ ClCFCl ２ , C.F. ２ ClCCl ２ F and CF ３ CClFCFClCF ３ Examples of the solvent include hydrofluorocarbons other than solvent F3, such as CF ３ CH ２ CF ２ CH ３ is preferred.

[0045] When the present solid contains another fluorinated solvent, the content of the other fluorinated solvent is preferably from 0.0001 to 0.4 mass %, more preferably from 0.0001 to 0.3 mass %, based on the total mass of the solid.

[0046] In the present solid material, the solvent preferably further contains water. When the present solid material contains water, the mechanical properties and moldability are better.

[0047] When the solid material contains water, the water content is preferably 0.01 to 0.5% by mass, more preferably 0.01 to 0.1% by mass, based on the total mass of the solid material. The water content in the solid material is determined from the difference between the weight loss of the solid material measured using a thermogravimetric differential thermal analyzer and the total content of the solvent and specific compound in the solid material measured using a headspace GC / MS device. More detailed measurement methods are described in the Examples below.

[0048] <Ratio S> As described above, in the present solid, the ratio S, which is the ratio of the total content of solvent F3 and the specific compound to the total content of the solvent and the specific compound ((content of solvent F3 + content of specific compound) / (content of solvent + content of specific compound)), is 90.0% by mass or less. The ratio S is preferably 0.5 to 60.0% by mass, more preferably 1.0 to 50.0% by mass, and even more preferably 1.0 to 12.0% by mass. If the ratio S is equal to or less than the upper limit, the crushability of the solid is superior, and if the ratio S is equal to or greater than the lower limit, the cohesiveness of the solid is reduced and the flowability is superior.

[0049] In the present solid material, the content of the solvent is preferably 0.01 to 2 mass %, more preferably 0.01 to 1.5 mass %, based on the total mass of the solid material.

[0050] The solid may be in the form of, for example, granules (beads), pellets, threads, or the like.

[0051] [Method for producing a solid product] The present solid product can be produced, for example, by a method comprising polymerizing the above-mentioned monomers (tetrafluoroethylene, ethylene, and a specific compound) in a polymerization solvent to produce a copolymer, heating a mixture containing the copolymer, polymerization solvent, and water with stirring to granulate the copolymer, and separating the polymerization solvent and unreacted monomers from the mixture, wherein the mixture is heated in two stages: a first stage at a lower temperature and a second stage at a higher temperature. Hereinafter, the above method, which is an example of a method for producing the present solid product, will be described.

[0052] <Production of Copolymer> The copolymer can be produced by polymerizing the above-mentioned monomers (tetrafluoroethylene, ethylene, and the specific compound) in a polymerization solvent by a known method such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization, and among these, production by solution polymerization is preferred. In producing the copolymer, in addition to the above-mentioned monomers and polymerization solvent, a polymerization initiator, a chain transfer agent, etc. can be used.

[0053] The polymerization initiator is preferably a radical polymerization initiator having a half-life of 10 hours at a temperature of 0 to 100°C, and particularly preferably a radical polymerization initiator having a temperature of 20 to 90°C. Specific examples of the polymerization initiator include the various polymerization initiators exemplified in WO 2013 / 015202. The polymerization initiator may be used alone or in combination of two or more types. The amount of the polymerization initiator used is preferably 0.01 to 0.9 parts by mass, particularly preferably 0.05 to 0.5 parts by mass, per 100 parts by mass of the amount of the monomer used.

[0054] As the polymerization solvent, fluorine-containing solvents such as hydrofluorocarbons, hydrofluoroethers, and perfluorocarbons can be used. The polymerization solvent may be used alone or in combination of two or more. As the polymerization solvent, solvent F is preferably used, solvent F3 is more preferably used, a combination of solvent F3 and hydrofluoroether is even more preferred, and a combination of solvent F3 and solvent F4 is particularly preferred. The amount of polymerization solvent used is preferably 5 times or more, more preferably 7 times or more, by mass ratio relative to the amount of monomer used. Also, it is preferably 20 times or less, more preferably 17 times or less.

[0055] In the production of the copolymer, a chain transfer agent may be used, and is preferably used. The chain transfer agent has a large chain transfer constant and can be added in a small amount, and is preferably an alcohol such as methanol, ethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoropropanol, 1,1,1,3,3,3-hexafluoroisopropanol, or 2,2,3,3,3-pentafluoropropanol; ２ H ２Preferred are hydrofluorocarbons such as n-pentane, n-hexane, and cyclohexane; ketones such as acetone; mercaptans such as methyl mercaptan; esters such as methyl acetate and ethyl acetate; and ethers such as diethyl ether and methyl ethyl ether. Among these, at least one selected from the group consisting of alcohols, hydrocarbons, and hydrofluorocarbons is preferred, with at least one selected from the group consisting of alcohols and hydrocarbons being more preferred, and alcohols being even more preferred, due to their higher chain transfer constant and high stability of the end groups of the copolymer. Among alcohols, methanol or ethanol is particularly preferred. Among these, methanol is most preferred due to its reactivity and availability. Two or more chain transfer agents may be used. The amount of chain transfer agent used is preferably 0.001 times or more, more preferably 0.005 times or more, by mass, relative to the amount of monomer used. Also, the amount is preferably 5 times or less, more preferably 4 times or less.

[0056] The polymerization temperature is preferably 15 to 90°C, more preferably 20 to 80°C, and particularly preferably 25 to 75°C. When the polymerization temperature is equal to or higher than the lower limit, the polymerizability is excellent. When the polymerization temperature is equal to or lower than the upper limit, the melting point of the copolymer can be improved. The polymerization pressure is preferably 0.5 to 3.0 MPa, and particularly preferably 0.9 to 2.5 MPa. The polymerization time is preferably 1 to 12 hours.

[0057] <Granulation> Next, the mixture containing the obtained copolymer, polymerization solvent, and water is heated with stirring to separate the polymerization solvent and unreacted monomer from the vessel, thereby carrying out granulation to produce a granulated product containing the copolymer.

[0058] In granulation, a mixture containing the copolymer, polymerization solvent, and water is first prepared. The mixture can be prepared, for example, by mixing a slurry containing the copolymer and polymerization solvent with water. To prepare the mixture, the slurry after the copolymer production may be used as is, or a concentrated slurry of the above slurry, or a slurry obtained by diluting the above slurry with a dilution solvent may be used. The dilution solvent may be the same as or different from the solvent used as the polymerization solvent, but is preferably the same. The amount of water used in granulation may be 20 to 500% by volume, more preferably 50 to 300% by volume, based on the total amount of the copolymer and polymerization solvent.

[0059] The mixture may be prepared by adding water to the polymerization tank containing the slurry after the production of the copolymer, or by transferring the slurry to a container (granulation tank) separate from the polymerization tank and mixing the slurry with water. It is preferable to transfer the slurry containing the copolymer and polymerization solvent from the polymerization tank to a granulation tank previously charged with water and mix them. The granulation tank may be a sealable container equipped with a stirring blade for stirring the contents, a heating means for heating the container or the contents, and a discharge means for discharging the separated gas. Commonly used stirring blades such as turbine blades and anchor blades can be used as the stirring blade. Heating means include, for example, a jacket, a hot water bath, an oil bath, and steam heating.

[0060] From the viewpoint of producing a solid with a low ratio S, when granulating a mixture containing a copolymer, a polymerization solvent, and water while stirring, it is preferable to carry out a first stage of granulation in which the mixture is heated at a lower temperature and the gas is discharged at a slower rate, and a second stage of granulation in which the mixture is heated at a higher temperature and the gas is discharged at a faster rate. When unreacted monomers and polymerization solvents are vaporized and separated from the copolymer by heating once during granulation, it is presumed that when substances such as unreacted monomers and polymerization solvents are vaporized, bubbles are generated in the mixture, especially in the granules whose shape is not sufficiently defined, resulting in the formation of non-uniform spaces within the granules. It is presumed that solvent F3 and the specific compound, which have relatively high lipophilicity and high affinity with the copolymer constituting the granules, tend to remain in the spaces within the granules. On the other hand, when granulation is performed in two stages, the first and second stages, it is assumed that in the first stage, gaseous raw material components such as unreacted tetrafluoroethylene and ethylene are separated from the mixture and discharged from the container, and in the subsequent second stage, substances dissolved in the mixture, such as unreacted specific compounds and polymerization solvents, are vaporized, and the vaporized substances are discharged from the container.In this case, in the first stage, while the gas that is likely to cause bubbles is slowly removed, a granule that has solidified to a certain extent is formed, and then in the second stage, dissolved substances such as unreacted specific compounds and polymerization solvents are vaporized and quickly removed.This is assumed to prevent the occurrence of uneven spaces within the granules and to prevent the residue of solvent F3 and specific compounds in the granules.

[0061] The rate at which the gas is discharged from the vessel in the first stage is preferably 0.01 to 0.50 kg / L / h, more preferably 0.01 to 0.40 kg / L / h, and even more preferably 0.01 to 0.30 kg / L / h. If the gas discharge rate in the first stage is equal to or less than the above upper limit, the vaporization of substances such as unreacted monomer and polymerization solvent in the first stage is suppressed, and the generation of bubbles during granulation can be suppressed, thereby further reducing the solid content S. The gas discharge rate is the mass of gas discharged per volume of the vessel used for granulation and per unit time.

[0062] The heating temperature in the first stage is preferably in the range of 25 to 95° C., more preferably in the range of 30 to 90° C., and even more preferably in the range of 30 to 90° C. The heating temperature in the first stage is preferably adjusted so that the rate at which gas is discharged from the container in the first stage falls within the above-mentioned range.

[0063] The pressure inside the vessel in the first stage is preferably 0.01 to 0.80 MPa, more preferably 0.01 to 0.70 MPa, and even more preferably 0.01 to 0.60 MPa. Note that the pressures described in this specification are gauge pressures based on atmospheric pressure.

[0064] The period for which the first stage is carried out may be, for example, 1 to 8 hours, and preferably 1 to 6 hours. The timing for ending the first stage and starting the second stage can be, for example, when the pressure inside the container in the first stage has remained constant for the same period of time. Once it is confirmed that the pressure inside the container has become constant, it can be assumed that most of the gaseous components contained in the space inside the container under the conditions of the first stage have been discharged.

[0065] The rate at which the gas is discharged from the vessel in the second stage is preferably 0.05 to 0.80 kg / L / h, more preferably 0.10 to 0.80 kg / L / h, and even more preferably 0.15 to 0.80 kg / L / h. If the gas discharge rate in the second stage is equal to or greater than the lower limit, substances such as the specific compound and polymerization solvent are rapidly removed from the granules, and a solid product with a lower ratio S can be produced. Furthermore, if the gas discharge rate in the second stage is equal to or less than the upper limit, a solid product with excellent shape stability can be produced.

[0066] The difference obtained by subtracting the gas discharge rate from the container in the first stage from the gas discharge rate from the container in the second stage is preferably 0.1 kg / L / h or more, more preferably 0.15 kg / L / h or more, and preferably 0.9 kg / L / h or less. If the difference in the gas discharge rates is equal to or greater than the above-mentioned lower limit, a solid product with a lower ratio S can be produced.

[0067] The heating temperature in the second stage is preferably in the range of 30 to 110°C, more preferably in the range of 30 to 90°C, and even more preferably in the range of 35 to 90°C. The heating temperature in the second stage is preferably adjusted so that the rate at which gas is discharged from the container in the second stage, or the difference obtained by subtracting the rate at which gas is discharged from the container in the first stage from the rate at which gas is discharged from the container in the second stage, falls within the above-mentioned range. The pressure inside the container in the second stage is preferably 0.01 to 1.00 MPa, more preferably 0.01 to 0.80 MPa, and even more preferably 0.01 to 0.70 MPa. The pressure at this time may be a gauge pressure.

[0068] The period for carrying out the second stage may be, for example, 0.5 to 8 hours, preferably 1 to 6 hours. The second stage may be terminated, for example, when a period of time has passed during which the amount of solvent discharged from the vessel and recovered in the second stage does not increase. Once it has been confirmed that the amount of recovered solvent has become constant, it can be assumed that most of the components, such as the solvent, discharged from the mixture containing the granulated product under the conditions of the second stage have been discharged.

[0069] The granules obtained by the above granulation may be collected from the container and then dried, if necessary. In the method for producing the present solid, the collected granules are preferably dried to obtain the present solid. A specific example of drying is a method in which the collected granules are transferred to a dryer and heated. By drying, substances such as water and solvent inside the granules can be further vaporized and removed.

[0070] Examples of the dryer used for drying include a batch type rotary dryer, an indirect heating dryer, a vacuum dryer, and a hot air dryer.

[0071] The drying temperature is preferably in the range of 60 to 250° C., more preferably in the range of 100 to 160° C. The drying time is preferably in the range of 1 to 48 hours, more preferably in the range of 1 to 24 hours.

[0072] The solid material obtained by the above drying or granulation may be melted and extruded using an extruder to form a solid material in other forms such as pellets or threads.

[0073] [Composition] The composition of the present invention (hereinafter also referred to as "the composition") contains the above-described solid and at least one component selected from the group consisting of other resins other than the copolymer, heat stabilizers, antioxidants, colorants, UV absorbers, fillers, crosslinking agents, crosslinking aids, and organic peroxides (hereinafter also referred to as "other components"). Because the composition contains the solid, molded articles with excellent surface properties can be formed by using the composition. The composition is preferably in a solid state. The content of the solid is preferably 50% by mass or more but less than 100% by mass, more preferably 70% by mass or more but less than 100% by mass, and even more preferably 90% by mass or more but less than 100% by mass, based on the total mass of the composition. The composition preferably does not contain any solvents or specific compounds other than those derived from the solid. The ratio of the content of the specific compound to the total content of the solvent and specific compound in the composition is preferably 0.1 to 50.0% by mass, more preferably 0.5 to 50.0% by mass.

[0074] The content of the above-mentioned "other components" in the present composition is preferably 0.0000001 to 70 parts by mass, more preferably 0.0000005 to 60 parts by mass, and even more preferably 0.000001 to 50 parts by mass, per 100 parts by mass of the copolymer in the present composition.

[0075] The present composition can be produced by melt-kneading the present solid or a powder obtained by pulverizing the present solid with the other components described above, which are used as needed, by a known method.

[0076] The solid material can be pulverized using a known pulverizer such as a rotor mill, hammer mill, turbo mill, or jet mill. Because the solid material has excellent pulverizability, for example, by using a powder obtained by pulverizing the solid material, a molded product with excellent surface smoothness can be produced. Furthermore, by heating and melting the powder obtained by pulverizing the solid material and molding it, a molded product with a small number of voids can be produced.

[0077] [Molded Article] The molded article of the present invention is obtained by molding the present solid or the present composition. Since the molded article of the present invention is formed using the present solid, it has excellent surface properties. Specific examples of molding methods include injection molding, extrusion molding, blow molding, press molding, rotational molding, electrostatic coating, and spray molding.

[0078] The molded article of the present invention may be a coating film formed using the present solid or the present composition. Examples of methods for forming a coating film include methods in which a powder obtained by pulverizing the present solid or the present composition containing the powder is used to form a coating film by rotational molding, electrostatic coating, or spray molding. The thickness of the coating film is preferably 1 μm to 10 mm, more preferably 50 μm to 5 mm, and even more preferably 100 μm to 3 mm.

[0079] Specific examples of the molded article of the present invention include nuts, bolts, joints, films, bottles, gaskets, wire coatings, tubes, hoses, pipes, valves, sheets, seals, packing, tanks, rollers, containers, cocks, connectors, filter housings, filter cages, flow meters, pumps, wafer carriers, and wafer boxes.

[0080] The present solid, the present composition or the above-mentioned molded article can be used for the following purposes. Fluid transfer components for food manufacturing equipment, such as food packaging films, lining materials, packings, sealing materials, and sheets for fluid transfer lines used in food manufacturing processes; chemical liquid transfer components, such as chemical stoppers, packaging films, lining materials, packings, sealing materials, and sheets for fluid transfer lines used in chemical manufacturing processes; inner lining components for chemical liquid tanks and piping in chemical plants or semiconductor factories; fuel transfer components, such as O-rings, tubes, packings, valve core materials, hoses, and sealing materials used in automotive fuel systems and peripheral devices, and hoses and sealing materials used in automotive automatic transmissions; carburetor flange gaskets, shaft seals, valve stem seals, sealing materials, and hoses used in automotive engines and peripheral devices, as well as other automotive components, such as automotive brake hoses, air conditioner hoses, radiator hoses, and wire coating materials; chemical liquid transfer components for semiconductor manufacturing equipment, such as O-rings, tubes, packings, valve core materials, hoses, sealing materials, rolls, gaskets, diaphragms, and fittings; coating and ink components such as paint rolls, hoses, tubes, and ink containers for coating equipment; food and beverage transport components such as tubes, hoses, belts, packing, and joints, such as food and beverage tubes or food and beverage hoses, food packaging materials, and glass cooking equipment; waste liquid transport components such as tubes and hoses for transporting waste liquid; high-temperature liquid transport components such as tubes and hoses for transporting high-temperature liquids; steam piping components such as tubes and hoses for steam piping; anti-corrosion tapes for piping, such as tapes wrapped around piping on ship decks, etc.; various coating materials such as electrical wire coating materials, optical fiber coating materials, and transparent surface coating materials and backing agents applied to the light-incident surface of photovoltaic elements in solar cells; sliding components such as diaphragms and various packings for diaphragm pumps; agricultural films, and weather-resistant covers for various roofing materials and side walls, etc.; interior materials used in the construction field, and glass coating materials such as non-flammable fire-resistant safety glass; lining materials such as laminated steel sheets used in home appliances, etc.; carrier films for fuel cells.In particular, the molded article of the present invention is particularly suitable for use as a chemical liquid transport member or coating material for semiconductor devices because of its excellent surface properties.

[0081] The present invention will be described in detail below with reference to examples. Examples 1 to 17 are working examples, and Examples 18 and 19 are comparative examples. However, the present invention is not limited to these examples. Various measurement methods and evaluation methods are as follows.

[0082] [Measurement] <Content of Solvent and Specific Compound in Solid> The content of the solvent and specific compound remaining in the solid was determined by analyzing the gas components present in the gas phase in the headspace when the solid was heated to 240°C using a headspace GC / MS device, and determining the content (mass%) of each component relative to the total mass of the copolymer. The water content in the solid was calculated from the difference between the weight loss of the solid measured using a thermogravimetric differential thermal analyzer (TG-DTA) and the total content of the solvent and specific compound in the solid measured using a headspace GC / MS device. The weight loss of the solid was determined by heating the solid from 30°C to 550°C at a heating rate of 10°C / min using a TG-DTA and measuring the weight of the solid before and after heating.

[0083] <Content of each unit in copolymer> The content (mol %) of each unit in the copolymer was calculated from the results of total fluorine measurement and melting F-NMR measurement. １ H and １３ The content of IAH units in the copolymer was calculated by C-NMR measurement. The content of IAH units in the copolymer was measured by the following method. The copolymer was press-molded to obtain a 200 μm film. In the infrared absorption spectrum, the absorption peak of the C═O stretching vibration in the IAH units in the copolymer was at 1870 cm －１ The absorbance of the absorption peak was measured, and the content of IAH units, M (mol%), was determined using the relation M = aL, where L is 1870 cm －１ where a is a coefficient. The value of a = 0.87 determined using IAH as a model compound was used.

[0084] <MFR (Melt Flow Rate)> Using a melt indexer (manufactured by Techno Seven Co., Ltd.), the mass (g) of solid matter flowing out of an orifice having a diameter of 2 mm and a length of 8 mm in 10 minutes was measured under conditions of a temperature of 297°C and a load of 49 N in accordance with ASTM D3159, and the obtained measured value was taken as the MFR (g / 10 min) of the copolymer.

[0085] <Melting Point> The melting point (°C) of the copolymer was determined from an endothermic peak detected when a solid substance was heated to 300°C at a heating rate of 10°C / min in an air atmosphere using a differential scanning calorimeter (DSC7020 manufactured by SII Corporation).

[0086] [Evaluation Tests] <Production of Powder> The solid sample obtained in each example was pulverized using a rotor mill (Rotor Speed ​​Mill P-14, manufactured by Fritsch) at a rotation speed of 1300 rpm to obtain a powder of the solid.

[0087] <Preparation of Coated Test Specimens> The surface of a 40 mm long, 150 mm wide, and 2 mm thick SUS304 stainless steel plate was sandblasted with 60-mesh alumina particles to a surface roughness Ra of 5 to 10 μm, followed by cleaning with ethanol to prepare a test substrate. A liquid primer ("Fluon (registered trademark) IL-300J" manufactured by AGC Inc.) was applied to the surface of the test substrate using an air-type liquid paint spray gun (manufactured by Meiji Machinery Works, Ltd.). The liquid primer-coated substrate was suspended in an oven and baked at 300°C for 30 minutes to form a 23 μm-thick primer layer, yielding a primer-coated substrate. Next, a solid powder was electrostatically sprayed onto the entire surface of the primer-coated substrate, followed by baking at 275°C for 15 minutes. This electrostatic coating and baking process was repeated three times to form a topcoat layer, yielding a coated test specimen. The topcoat layer had a thickness of 200 μm.

[0088] <Appearance Evaluation (Surface Smoothness)> The topcoat layer of the coated test piece was visually and tactilely inspected, and the appearance of the coated test piece was evaluated according to the following evaluation criteria. The higher the appearance evaluation of the coated test piece, the better the crushability of the solid object.

[0089] (Appearance evaluation criteria) ◎: A top coat layer is formed over the entire surface of the substrate. No irregularities are visible to the naked eye on the surface of the top coat layer, and a gloss is visible. No irregularities can be felt on the surface of the top coat layer by palpation. ○: A top coat layer is formed over the entire surface of the substrate. Irregularities are visible to the naked eye on the surface of the top coat layer, and no gloss is visible. No irregularities can be felt on the surface of the top coat layer by palpation. ×: Irregularities can be felt on the surface of the top coat layer by palpation. Alternatively, areas on the substrate where the top coat layer has not been formed due to foaming or the like can be visually confirmed.

[0090] [Example 1] A stainless steel polymerization vessel having an internal volume of 1.3 L (liters) and equipped with a stirrer and a jacket was evacuated, and then CF ３ CH ２ CF ２ CH ３ (hereinafter also referred to as "HFC-365mfc") 614g and CF ３ (CF ２ ) ４ CF ２ 541 g of H (hereinafter also referred to as "CH"), 10.2 g of methanol, and CH as a specific compound. ２ =CH(CF ２ ) ４ 7.5 g of F(PFBE) was charged. While stirring the mixture, 146 g of tetrafluoroethylene (TFE) and 8.7 g of ethylene (E) were charged, and then hot water was run through the jacket to raise the temperature inside the polymerization vessel to 66°C (polymerization temperature). The pressure inside the polymerization vessel at this time was 1.5 MPaG (gauge pressure). After the temperature stabilized, a 1% by mass solution of tert-butyl peroxypivalate (hereinafter also referred to as "PBPV") (solvent: CF ３ CH ２ CF ２ CH ３) was injected, and polymerization was initiated. During polymerization, a mixed gas of TFE / E = 54 / 46 molar ratio was added so that the internal pressure was constant at 1.5 MPaG. In addition, 1.0 mL of PFBE (an amount equivalent to 1.0 mol% relative to the total number of moles of TFE and E) was added every time 10 g of the TFE / E mixed gas added during polymerization was consumed. 210 minutes after the start of the reaction, when 100 g of the mixed gas of TFE / E = 54 / 46 molar ratio was added, the polymerization vessel was cooled, and the polymerization was terminated.

[0091] Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a 2.6 L vessel, followed by the addition of an equal volume of water to the slurry. The slurry was heated with stirring to remove only the gas in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 90°C so that the gas discharge rate X1 / V was 0.02 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel was constant at 0.1 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 85 to 100°C so that the discharge rate X2 / V of the vaporized solvent was 0.58 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, yielding a granulated product. The resulting granulated product was then dried in an oven at 150°C to obtain a granular solid product 1. The above-mentioned exhaust rate X1 / V is the average value of the gas exhaust rate during the first stage period, and the above-mentioned exhaust rate X2 / V is the average value of the gas exhaust rate during the second stage period.

[0092] As a result of the above measurements, the MFR of Copolymer 1 contained in Solid 1 was 14 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 53.08 / 44.60 / 2.32 (respectively mole %), and the melting point was 249° C. The proportion S of the obtained Solid 1 was 6.3 mass%.

[0093] [Example 2] TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of the components used in the polymerization and the polymerization conditions were changed as shown in Table 1. "AE-3000" in Table 1 represents CF３ CH ２ OCF ２ CF ２ H. Thereafter, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by the addition of water at an equal volume to the slurry. The slurry was heated with stirring to remove only the gas in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.06 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.2 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 90°C so that the discharge rate X2 / V of the vaporized solvent was 0.79 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained. The resulting granulated product was then dried in an oven at 150°C to obtain a granular solid product 2. As a result of the above measurements, the MFR of Copolymer 2 contained in Solid 2 was 6 g / 10 min, the composition was TFE unit / E unit / PFBE unit=53.41 / 45.58 / 1.01 (respectively mole %), and the melting point was 261° C. The proportion S of the obtained Solid 2 was 34.9 mass%.

[0094] [Example 3] TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, and the same volume of water as the slurry was added. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.05 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.4 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 95°C so that the discharge rate X2 / V of the vaporized solvent was 0.78 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained. The granulated product was then dried in an oven at 150 ° C to obtain a granular solid product 3. As a result of the above measurements, the MFR of the copolymer 3 contained in the solid product 3 was 12 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 53.36 / 45.10 / 1.54 (respectively mole %), and the melting point was 256 ° C. The proportion S of the obtained solid product 3 was 44.9 mass%.

[0095] Example 4 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.06 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.3 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 95°C so that the discharge rate X2 / V of the vaporized solvent was 0.79 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained.The granulated product obtained was then dried in an oven at 150 ° C to obtain a granular solid product 4.As a result of the above measurements, the MFR of copolymer 4 contained in solid product 4 was 11 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 53.40 / 45.50 / 1.10 (respectively mole %), and the melting point was 261 ° C.The proportion S of the obtained solid product 4 was 10.9 mass%.

[0096] Example 5 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.04 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.3 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 100°C so that the discharge rate X2 / V of the vaporized solvent was 0.81 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. When it was confirmed that the amount of recovered solvent did not increase and remained constant, the second stage was terminated, and a granulated product was obtained.The granulated product obtained was then dried in an oven at 150 ° C to obtain a granular solid product 5.As a result of the above measurements, the MFR of copolymer 5 contained in solid product 5 was 23 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 53.23 / 44.70 / 2.07 (respectively mole %), and the melting point was 251 ° C.The proportion S of the obtained solid product 5 was 15.3 mass%.

[0097] Example 6 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.05 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.1 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 105°C so that the discharge rate X2 / V of the vaporized solvent was 0.21 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained.The granulated product obtained was then dried in an oven at 150 ° C to obtain a granular solid product 6.As a result of the above measurements, the MFR of the copolymer 6 contained in the solid product 6 was 25 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 58.00 / 38.50 / 3.50 (respectively mole %), and the melting point was 233 ° C.The proportion S of the obtained solid product 6 was 5.1 mass%.

[0098] Example 7 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.05 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.3 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 100°C so that the discharge rate X2 / V of the vaporized solvent was 0.43 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained. The granulated product was then dried in an oven at 150 ° C to obtain a granular solid product 7. As a result of the above measurements, the MFR of the copolymer 7 contained in the solid product 7 was 13 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 58.10 / 38.40 / 3.50 (respectively mole %), and the melting point was 233 ° C. The proportion S of the obtained solid product 7 was 17.2 mass%.

[0099] Example 8 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.10 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.3 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 105°C so that the discharge rate X2 / V of the vaporized solvent was 0.78 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained. The granulated product was then dried in an oven at 150 ° C to obtain a granular solid product 8. As a result of the above measurements, the MFR of the copolymer 8 contained in the solid product 8 was 38 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 57.48 / 38.92 / 3.60 (respectively mole %), and the melting point was 233 ° C. The proportion S of the obtained solid product 8 was 6.1 mass%.

[0100] Example 9 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.03 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.4 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 97°C so that the discharge rate X2 / V of the vaporized solvent was 0.78 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained. The granulated product was then dried in an oven at 150 ° C to obtain a granular solid product 9. As a result of the above measurements, the MFR of the copolymer 9 contained in the solid product 9 was 11 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 57.80 / 38.20 / 4.00 (respectively mole %), and the melting point was 227 ° C. The proportion S of the obtained solid product 9 was 20.3 mass%.

[0101] Example 10 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.05 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.2 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 100°C so that the discharge rate X2 / V of the vaporized solvent was 0.56 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained.The granulated product was then dried in an oven at 150 ° C to obtain a granular solid product 10.As a result of the above measurements, the MFR of the copolymer 10 contained in the solid product 10 was 23 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 58.52 / 39.34 / 2.14 (respectively mole %), and the melting point was 244 ° C.The proportion S of the obtained solid product 10 was 16.0 mass%.

[0102] Example 11 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.25 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.3 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 100°C so that the discharge rate X2 / V of the vaporized solvent was 0.49 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained.The granulated product was then dried in an oven at 150 ° C to obtain a granular solid product 11.As a result of the above measurements, the MFR of the copolymer 11 contained in the solid product 11 was 5 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 58.30 / 38.50 / 3.20 (respectively mole %), and the melting point was 231 ° C.The proportion S of the obtained solid product 11 was 28.8 mass%.

[0103] Example 12 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.03 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.2 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 105°C so that the discharge rate X2 / V of the vaporized solvent was 0.58 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained.The granulated product was then dried in an oven at 150 ° C to obtain a granular solid product 12.As a result of the above measurements, the MFR of the copolymer 12 contained in the solid product 12 was 7 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 48.60 / 48.50 / 2.90 (respectively mole %), and the melting point was 248 ° C.The proportion S of the obtained solid product 12 was 10.4 mass%.

[0104] [Example 13] A stainless steel polymerization vessel having an internal volume of 1.3 L (liters) and equipped with a stirrer and a jacket was evacuated, and then CF ３ CH ２ OCF ２ CF ２ 1148g of H (AE-3000) and CF ３ (CF ２ ) ４ CF ２ 23 g of H(CH), 5.5 g of methanol, and CH as a specific compound ２ = CHCF ２ CF ３While stirring the mixture, 155 g of TFE and 5 g of ethylene (E) were charged, and then warm water was run through the jacket to raise the temperature inside the polymerization vessel to 66°C (polymerization temperature). At this time, the pressure inside the polymerization vessel was 1.5 MPaG. After the temperature stabilized, a 1% by mass solution of tert-butyl peroxypivalate (PBPV) (solvent: CF ３ CH ２ OCF ２ CF ２ 17 mL of TFE / E was injected to initiate polymerization. During polymerization, a mixed gas of TFE / E=60 / 40 molar ratio was added so that the internal pressure was kept constant at 1.5 MPaG. In accordance with the amount of the mixed gas charged, CH 3 was added in an amount equivalent to 2.0 mol % relative to the total number of moles of TFE and E. ２ = CHCF ２ CF ３ and 0.8 mol % of itaconic anhydride (hereinafter also referred to as "IAH") were continuously charged. 360 minutes after the start of the reaction, 100 g of a mixed gas having a molar ratio of TFE / E=60 / 40 was added, and then the polymerization vessel was cooled to terminate the polymerization.

[0105] Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L. An equal volume of water to the slurry was added. The slurry was heated while stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.02 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel was constant at 0.2 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 100°C so that the discharge rate X2 / V of the vaporized solvent was 0.30 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, yielding a granulated product. The resulting granulated product was then dried in an oven at 150°C to obtain a granular solid product 13. As a result of the above measurement, the MFR of the copolymer 13 contained in the solid matter 13 was 25 g / 10 min, and the composition was TFE unit / E unit / CH ２ = CHCF ２ CF３ The ratio of IAH units to IAH units was 53.40 / 43.75 / 2.10 / 0.75 (mol %), and the melting point was 236° C. The proportion S of the obtained solid 13 was 18.0 mass %.

[0106] Example 14 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 85°C so that the gas discharge rate X1 / V was 0.03 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.2 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 80 to 100°C so that the discharge rate X2 / V of the vaporized solvent was 0.65 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained. The granulated product was then dried in an oven at 150 ° C to obtain a granular solid product 14. As a result of the above measurements, the MFR of the copolymer 14 contained in the solid product 14 was 28 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 58.00 / 38.49 / 3.51 (respectively mole %), and the melting point was 236 ° C. The proportion S of the obtained solid product 14 was 50.4 mass%.

[0107] Example 15 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 40 to 95°C so that the gas discharge rate X1 / V was 0.03 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.3 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 95 to 110°C so that the discharge rate X2 / V of the vaporized solvent was 0.18 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. When it was confirmed that the amount of recovered solvent did not increase and remained constant, the second stage was terminated, and a granulated product was obtained.The granulated product obtained was then dried in an oven at 150 ° C to obtain a granular solid product 15.As a result of the above measurements, the MFR of the copolymer 15 contained in the solid product 15 was 7 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 53.10 / 45.96 / 0.94 (respectively mole %), and the melting point was 261 ° C.The proportion S of the obtained solid product 15 was 2.4 mass%.

[0108] Example 16 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 1, except that the types and amounts of each component used in the polymerization and the polymerization conditions were changed as shown in Table 1. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a vessel with an internal volume of 2.6 L, followed by addition of water at the same volume as the slurry. The slurry was heated with stirring, and only the gas was removed in the first stage. The temperature inside the vessel was adjusted within a range of 30 to 80°C so that the gas discharge rate X1 / V was 0.05 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel had become constant at 0.4 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 70 to 88°C so that the discharge rate X2 / V of the vaporized solvent was 0.42 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained.The granulated product was then dried in an oven at 150 ° C to obtain a granular solid product 16.As a result of the above measurements, the MFR of the copolymer 16 contained in the solid product 16 was 10 g / 10 min, the composition was TFE unit / E unit / PFBE unit = 53.10 / 45.30 / 1.60 (respectively mole %), and the melting point was 253 ° C.The proportion S of the obtained solid product 16 was 83.5 mass%.

[0109] [Example 17] As shown in Table 1, the same procedure as in Example 1 was repeated except that the types and amounts of the components used in the polymerization and the polymerization conditions were changed. ２ = CFO (CF ２ ) ２ CF ３ In Example 17, CF was used instead of 7.5 g of PFBE. ２ = CFO (CF ２ ) ２ CF ３ In addition, "Novec7100" shown in Table 1 is F(CF ２ ) ４ OCH ３This means that the residual monomer gas was then purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a 2.6 L vessel, to which the same volume of water as the slurry was added. The slurry was heated while stirring, and in the first stage, only the gas was removed. The temperature inside the vessel was adjusted within a range of 30 to 75°C so that the gas discharge rate X1 / V was 0.09 kg / L / h. The first stage was terminated when it was confirmed that the pressure inside the vessel was constant at 0.5 MPa. Next, in the second stage, the slurry was heated to vaporize and discharge the solvent. The temperature inside the vessel was adjusted within a range of 70 to 90°C so that the discharge rate X2 / V of the vaporized solvent was 0.30 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. The second stage was terminated when it was confirmed that the amount of recovered solvent did not increase and remained constant, and a granulated product was obtained. The resulting granulated product was then dried in an oven at 150°C to obtain a granular solid product 17. As a result of the above measurement, the MFR of the copolymer 17 contained in the solid matter 17 was 15 g / 10 min, and the composition was TFE unit / E unit / CF ２ = CFO (CF ２ ) ２ CF ３ The units were 53.24 / 44.35 / 2.41 (respectively mole %), and the melting point was 248° C. The proportion S of the obtained solid 17 was 88.4 mass %.

[0110] Example 18 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 2. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a 2.6 L vessel, followed by addition of the same volume of water as the slurry. The slurry was heated while stirring, and the gas and vaporized solvent were discharged. The temperature inside the vessel was adjusted within the range of 30 to 95°C so that the gas and vaporized solvent discharge rate was 0.25 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. Heating was terminated when it was confirmed that the amount of recovered solvent no longer increased and remained constant, yielding a granulated product. The resulting granulated product was then dried in an oven at 150°C, yielding a granular solid product 18. As a result of the above measurements, the MFR of the copolymer 18 contained in the solid material 18 was 6 g / 10 min, the composition was TFE unit / E unit / PFBE unit=53.41 / 45.58 / 1.01 (respectively mole %), and the melting point was 261° C. The proportion S of the obtained solid material 18 was 95.3 mass %.

[0111] Example 19 TFE, ethylene, and PFBE were copolymerized in the same manner as in Example 3. Subsequently, residual monomer gas was purged from the polymerization vessel to atmospheric pressure, and the slurry was transferred to a 2.6 L vessel, followed by addition of the same volume of water as the slurry. The slurry was heated while stirring, and the gas and vaporized solvent were discharged. The temperature inside the vessel was adjusted within the range of 30 to 105°C so that the discharge rate of the gas and vaporized solvent was 0.90 kg / L / h. The solvent discharged from the vessel was recovered in a tank using a cooling mechanism. Heating was terminated when it was confirmed that the amount of recovered solvent had not increased and remained constant, and a granulated product was obtained. The resulting granulated product was then dried in an oven at 150°C, yielding a granular solid product 19. As a result of the above measurements, the MFR of Copolymer 19 contained in Solid 19 was 12 g / 10 min, the composition was TFE unit / E unit / PFBE unit=53.40 / 45.06 / 1.54 (respectively mole %), and the melting point was 256° C. The proportion S of the obtained Solid 19 was 97.6 mass %.

[0112] Table 1 shows the compounds used in the production of the copolymers in each example, the polymerization conditions for the copolymers, and the production conditions for the solids. Table 2 shows the compositions and properties of the copolymers obtained in each example, as well as the measurement and evaluation results for the solids. In the table, the "TFE units", "E units", "A units", and "IAH units" columns indicate the content (unit: mol%) of each unit relative to the total units contained in the copolymer obtained in each example. In the table, the "solvent" column under "solid" indicates the ratio (unit: mass%) of the total content of solvents contained in the solid to the total mass of the solid obtained in each example. Note that water was contained in all of the solids of Examples 1 to 17. Furthermore, CF corresponding to solvent F4 was also contained in all of the solids of Examples 2 to 16. ３ CH ２ OCF ２ CF ２ The solid in Example 17 contains F(CF), which corresponds to solvent F4. ２ ) ４ OCH ３ It included:

[0113]

[0114]

[0115]

[0116] As shown in the table, it was confirmed that solids in which the ratio of the total content of solvent F3 and the specific compound to the total content of the solvent and the specific compound was 90.0 mass% or less had excellent grindability (Examples 1 to 17).

[0117] The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2023-220827, filed on December 27, 2023, are incorporated herein by reference as part of the disclosure of the present invention.

Claims

1. A copolymer comprising a unit based on tetrafluoroethylene, a unit based on ethylene, and a unit based on a specific compound selected from the group consisting of a compound represented by formula (1) and a compound represented by formula (2), the specific compound, and a solid material containing a solvent that is a compound different from the specific compound, wherein the solvent contains a fluorinated solvent containing a hydrogen atom and a fluorine atom, which may have an ether bond, the fluorinated solvent contains a hydrofluorocarbon having a group represented by formula (3), and the ratio of the total content of the hydrofluorocarbon and the specific compound to the total content of the solvent and the specific compound is 90.0% by mass or less. CX １ ２ =CX ２ (CF ２ ) ｍ F (1) CF ２ =CF−O−(CF ２ ) ｎ F (2) CF ３ (CF ２ ) ｐ −* (3) In formula (1), X １ and X ２ each independently represent a hydrogen atom or a fluorine atom, and m represents an integer from 1 to 6. In formula (2), n represents an integer from 1 to 6. In formula (3), p represents an integer of 1 or more, and * represents a bonding site with an adjacent atom.

2. The solid according to claim 1, wherein the content of the unit based on tetrafluoroethylene is 48.00 to 64.90 mol% with respect to all the units contained in the copolymer.

3. The solid according to claim 1 or 2, wherein the content of the unit based on ethylene is 35.00 to 51.90 mol% with respect to all the units contained in the copolymer.

4. The solid according to claim 1 or 2, wherein the content of the unit based on the specific compound in the copolymer is 0.10 to 5.00 mol% with respect to all the units contained in the copolymer.

5. The solid according to claim 1 or 2, wherein the fluorine-containing solvent further contains hydrofluoroether.

6. The solid according to claim 5, wherein the hydrofluoroether contains a compound represented by the formula (4). R １ -O-R ２ (4) In the formula (4), R １ represents a fluoroalkyl group having 2 to 6 carbon atoms, and R ２ represents a fluoroalkyl group or an alkyl group having 1 to 4 carbon atoms, and the total number of carbon atoms of R １ and R ２ is 8 or less.

7. The solid according to claim 1 or 2, wherein the solvent further contains water.

8. The solid according to claim 1 or 2, wherein the content of the solvent is 0.01 to 2% by mass with respect to the total mass of the solid.

9. The solid according to claim 1 or 2, wherein the content of the hydrofluorocarbon is 0.001 to 1.5% by mass with respect to the total mass of the solid.

10. A composition comprising the solid according to claim 1 or 2 and at least one component selected from the group consisting of other resins, heat stabilizers, antioxidants, colorants, ultraviolet absorbers, fillers, crosslinking agents, crosslinking aids, and organic peroxides other than the copolymer.

11. A molded article, characterized in that it is obtained by molding the solid according to claim 1 or 2.

12. A molded article, characterized in that it is obtained by molding the composition according to claim 10.

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