Copolymers, molded articles, extruded articles, blow-molded articles, transfer-molded articles, and coated electric wires

Abstract

The present application provides a copolymer containing tetrafluoroethylene units and perfluoro(propyl vinyl ether) units, the content of the perfluoro(propyl vinyl ether) units being 3.9 to 5.5 mass% relative to the total monomer units, the melt flow rate at 372°C being 2.8 to 4.0 g / 10 minutes, the number of functional groups being 20 or less per 10 6 main chain carbon atoms.

Description

Technical Field

[0001] This invention relates to copolymers, molded articles, extruded articles, blow-molded articles, transfer-molded articles, and coated wires. Background Technology

[0002] Patent Document 1 describes a molded article comprising a copolymer containing tetrafluoroethylene units and perfluoro(alkyl vinyl ether) units, wherein the surface roughness Ra of the molded article is less than 0.20 μm and the water contact angle of the molded article is less than 80 degrees.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2020-002341 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The purpose of this invention is to provide a copolymer that is not easily deformed even in the molten state, and can form a very thick coating layer with uniform thickness on a core wire with a very large diameter by extrusion molding. It can be easily molded into a film with uniform thickness, and has excellent wear resistance, low oxygen permeability, low reagent permeability, creep resistance and rigidity at a high temperature of 110°C. It also does not easily cause fluoride ions to dissolve into reagents such as hydrogen peroxide.

[0008] Methods for solving problems

[0009] According to the present invention, a copolymer is provided comprising tetrafluoroethylene units and perfluoro(propyl vinyl ether) units, wherein the content of perfluoro(propyl vinyl ether) units is 3.9% to 5.5% by mass relative to all monomer units, the melt flow rate at 372°C is 2.8 g / 10 min to 4.0 g / 10 min, and the number of functional groups per 10 6 The main chain has fewer than 20 carbon atoms.

[0010] In addition, according to the present invention, an extruded article, a blow-molded article or a transfer-molded article is provided, which contains the above-mentioned copolymer.

[0011] In addition, according to the present invention, a coated wire is provided having a coating layer containing the above-mentioned copolymer.

[0012] In addition, according to the present invention, a molded body is provided, which is a molded body containing the above-mentioned copolymer, wherein the molded body is a piping component, an electrical wire sheath, a pipe, a membrane, or a compressed component.

[0013] The effects of the invention

[0014] According to the present invention, a copolymer is provided that is not easily deformed even in the molten state, and can form a very thick coating layer with uniform thickness on a core wire with a very large diameter by extrusion molding. It can be easily molded into a film with uniform thickness and has excellent wear resistance, low oxygen permeability, low reagent permeability, creep resistance and rigidity at a high temperature of 110°C. It is also less likely to cause fluoride ions to dissolve into reagents such as hydrogen peroxide. Detailed Implementation

[0015] The specific embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments.

[0016] The copolymer of the present invention contains tetrafluoroethylene (TFE) units and perfluoro(propyl vinyl ether) (PPVE) units.

[0017] Polymeric fatty acids (PFAs) containing TFE and PPVE units are used as materials for forming piping components such as pipes, fittings, gaskets, and seals for conveying fluids. In particular, PFA-lined pipes, formed by transfer molding and lining large-diameter pipes with PFA, are used, for example, in chemical equipment for conveying corrosive, high-temperature reagents. Such pipes carry large volumes of high-temperature fluids, which can sometimes lead to wear or deformation problems. However, for PFA used in such pipes, excellent moldability for easy lining is required; therefore, PFA with excellent moldability and the ability to impart creep resistance and other strengths to the lined pipes is needed. Furthermore, when manufacturing large-diameter pipes by extrusion molding of PFA, the molten copolymer discharged from the extruder is easily deformed by its own weight before cooling and solidifying; therefore, a copolymer that is difficult to deform even in the molten state is required.

[0018] Discovery: By appropriately adjusting the PPVE unit content, melt flow rate (MFR), and number of functional groups in copolymers containing TFE and PPVE units, the moldability of the copolymer is significantly improved. Molded bodies containing such copolymers exhibit excellent abrasion resistance, low oxygen permeability, low reagent permeability, creep resistance, and rigidity at 110°C. Using such copolymers, piping can be easily lined, while suppressing abrasion and deformation caused by contact with high-temperature fluids, resulting in lining materials that inhibit fluid oxidation and prevent reagent diffusion. Furthermore, the copolymers of this invention are not easily deformed even in the molten state; therefore, by using the copolymers of this invention, large-diameter pipes with high dimensional accuracy can be manufactured using extrusion molding.

[0019] Furthermore, by using extrusion molding to form the copolymer of the present invention, a very thick coating layer with uniform thickness can be formed on core wires with very large diameters, resulting in aesthetically pleasing tubes and easily molded into films of uniform thickness. Thus, the copolymer of the present invention can be used not only as a material for piping components but also for a wide range of applications such as wire coatings, tubes, and films.

[0020] The copolymers of the present invention are melt-processable fluoropolymers. Melt processability refers to the ability to melt and process the polymer using existing processing equipment such as extruders and injection molding machines.

[0021] The content of PPVE units in the copolymer is 3.9% to 5.5% by mass relative to all monomer units. The content of PPVE units in the copolymer is preferably 4.0% by mass or more, more preferably 4.1% by mass or more, preferably 5.4% by mass or less, more preferably 5.3% by mass or less, further preferably 5.2% by mass or less, particularly preferably 5.1% by mass or less, and most preferably 5.0% by mass or less. By keeping the content of PPVE units in the copolymer within the above range, a molded body with excellent abrasion resistance, low oxygen permeability, low reagent permeability, creep resistance, and rigidity at 110°C can be obtained. If the content of PPVE units in the copolymer is too low, the abrasion resistance of the molded body containing the copolymer is poor. If the content of PPVE units in the copolymer is too high, the oxygen permeability, creep resistance, and rigidity at 110°C of the molded body containing the copolymer are poor.

[0022] The content of TFE units in the copolymer is preferably 94.5% to 96.1% by mass relative to all monomer units, more preferably 94.6% by mass or more, even more preferably 94.7% by mass or more, even more preferably 94.8% by mass or more, particularly preferably 94.9% by mass or more, most preferably 95.0% by mass or more, and more preferably 95.9% by mass or less. By keeping the content of TFE units in the copolymer within the above range, a molded article with excellent oxygen permeability, creep resistance, and rigidity at 110°C can be obtained. If the content of TFE units in the copolymer is too high, the wear resistance of the molded article containing the copolymer may deteriorate. If the content of TFE units in the copolymer is too low, the oxygen permeability, creep resistance, and rigidity at 110°C of the molded article containing the copolymer may deteriorate.

[0023] In this invention, the content of each monomer unit in the copolymer is determined by... 19 Determined by F-NMR method.

[0024] The copolymer may also contain monomer units from monomers capable of copolymerizing with TFE and PPVE. In this case, the content of monomer units capable of copolymerizing with TFE and PPVE is preferably 0 to 1.6% by mass, more preferably 0.05% to 1.0% by mass, and even more preferably 0.1% to 0.7% by mass, relative to all monomer units of the copolymer.

[0025] Monomers capable of copolymerizing with TFE and PPVE include hexafluoropropylene (HFP) and CZ. 1 Z 2 =CZ 3 (CF2) n Z 4 (where Z) 1 Z 2 and Z 3 Same or different, represented by H or F, Z 4 Vinyl monomers (represented by H, F, or Cl, where n represents an integer from 2 to 10), CF2 = CF-ORf 1 (where Rf) 1 Perfluoro(alkyl vinyl ether) [PAVE] (except for PPVE) represented by perfluoroalkyl groups having 1 to 8 carbon atoms, and CF2=CF-OCH2-Rf 1 (where Rf is in the formula) 1 This refers to perfluoroalkyl groups having 1 to 5 carbon atoms. Alkyl perfluorovinyl ether derivatives, etc., are also included. HFP is preferred.

[0026] The copolymer is preferably selected from at least one of the groups consisting of copolymers composed only of TFE units and PPVE units, and TFE / HFP / PPVE copolymers, and more preferably copolymers composed only of TFE units and PPVE units.

[0027] The melt flow rate (MFR) of the copolymer is from 2.8 g / 10 min to 4.0 g / 10 min. The MFR of the copolymer is preferably 2.9 g / 10 min, more preferably 3.9 g / 10 min or less, and more preferably 3.8 g / 10 min. By keeping the MFR of the copolymer within the above range, the moldability of the copolymer is improved, and molded articles with low oxygen permeability, excellent creep resistance, and excellent rigidity at 110°C can be obtained. If the MFR of the copolymer is too low, it is difficult to obtain molded articles with low oxygen permeability and excellent rigidity at 110°C. If the MFR of the copolymer is too high, it is difficult to obtain molded articles with excellent creep resistance.

[0028] The copolymers of the present invention, by appropriately adjusting the PPVE unit content, melt flow rate (MFR), and number of functional groups in copolymers containing TFE and PPVE units, can be molded by injection molding or by wire coating extrusion molding. In injection molding, copolymers that flow sufficiently through heating are suitable; however, if a copolymer with excessively high fluidity at high temperatures is used to form the wire coating in extrusion molding, the variation in outer diameter can sometimes be large. The copolymers of the present invention can produce aesthetically pleasing injection-molded bodies even when molded by injection molding, and can produce coated wires with minimal variation in outer diameter even when molded by extrusion molding.

[0029] In this invention, MFR is defined according to AS. T The MD1238 uses a melt indexer to obtain the value in the form of the mass (g / 10 min) of polymer flowing out of a nozzle with an inner diameter of 2.1 mm and a length of 8 mm every 10 minutes at 372°C and a load of 5 kg.

[0030] MFR can be adjusted by modifying the type and amount of polymerization initiator and the type and amount of chain transfer agent used in monomer polymerization.

[0031] per 10 of the copolymer 6 The number of functional groups per main chain carbon atom is less than 20. For every 10... 6 The number of functional groups per carbon atom in the main chain is preferably 15 or less, more preferably 10 or less, and even more preferably less than 6. By keeping the number of functional groups in the copolymer within the above range, it is possible to obtain a molded article with excellent oxygen permeability, reagent permeability, and creep resistance, and which does not easily allow fluoride ions to dissolve into reagents such as hydrogen peroxide.

[0032] The identification of the types of functional groups and the determination of the number of functional groups mentioned above can be achieved using infrared spectroscopy.

[0033] Regarding the number of functional groups, specifically, it was determined using the following method. First, the above copolymer was cold-pressed to produce a film with a thickness of 0.25 mm to 0.3 mm. The film was analyzed by Fourier transform infrared spectroscopy to obtain the infrared absorption spectrum of the above copolymer, and a differential spectrum was obtained compared with the background spectrum of a fully fluorinated copolymer without functional groups. The number of functional groups in the above copolymer was calculated from the absorption peaks of specific functional groups shown in the differential spectrum according to the following formula (A). 6 The number of functional groups N per carbon atom.

[0034] N = I × K / t (A)

[0035] I: Absorbance

[0036] K: Correction coefficient

[0037] t: Membrane thickness (mm)

[0038] For reference, the absorption frequencies, molar absorptivity, and correction factors for some functional groups are shown in Table 1. Furthermore, the molar absorptivity was determined using FT-IR measurements of low-molecular-weight model compounds.

[0039] [Table 1]

[0040] Table 1

[0041]

[0042] The absorption frequencies of -CH2CF2H, -CH2COF, -CH2COOH, -CH2COOCH3, and -CH2CONH2 are tens of Kaiser (cm⁻¹) lower than those of -CF2H, -COF, free -COOH, and bonded -COOH, -COOCH3, and -CONH2, respectively, as shown in the table. 1 ).

[0043] For example, the number of functional groups in -COF refers to the number of functional groups originating from the absorption frequency of -CF2COF at 1883 cm⁻¹. 1 The number of functional groups derived from the absorption peak at 1840 cm⁻¹ and the absorption frequency originating from -CH₂COF were also analyzed. 1 The total number of functional groups obtained from the absorption peak at the given location.

[0044] Functional groups are those present at the ends of the main chain or side chains of the copolymer, and those present in the main chain or side chains. The number of functional groups can be the total number of -CF=CF2, -CF2H, -COF, -COOH, -COOCH3, -CONH2, and -CH2OH.

[0045] The aforementioned functional groups are introduced into the copolymer, for example, through chain transfer agents or polymerization initiators used in the manufacturing of the copolymer. For instance, when an alcohol is used as a chain transfer agent, or when a peroxide having a -CH2OH structure is used as a polymerization initiator, -CH2OH is introduced to the ends of the copolymer's main chain. Alternatively, the aforementioned functional groups are introduced to the ends of the copolymer's side chains by polymerizing monomers containing functional groups.

[0046] By fluorinating the copolymer having such functional groups, copolymers having the number of functional groups within the aforementioned range can be obtained. That is, the copolymer of the present invention is preferably a fluorinated copolymer. The copolymer of the present invention also preferably has a -CF3 terminal group.

[0047] The melting point of the copolymer is preferably 295°C to 315°C, more preferably 298°C or higher, even more preferably 300°C or higher, particularly preferably 301°C or higher, more preferably 310°C or lower, and even more preferably 305°C or lower. By keeping the melting point within the above range, a copolymer that provides excellent wear resistance, low oxygen permeability, low reagent permeability, creep resistance, and superior rigidity at a high temperature of 110°C can be obtained.

[0048] In this invention, the melting point can be determined using a differential scanning calorimeter (DSC).

[0049] The oxygen permeability coefficient of the copolymer is preferably 970 cm⁻¹. 3 ·mm / (m 2 The oxygen permeability is below 24 h atm. The copolymers of the present invention exhibit excellent low oxygen permeability because the content of PPVE units, melt flow rate (MFR), and number of functional groups in copolymers containing TFE and PPVE units are appropriately adjusted. Therefore, oxygen does not easily permeate the molded body formed from the copolymer, and thus, for example, piping components obtained using the copolymers of the present invention can be appropriately used for conveying reagents for which oxidation should be avoided.

[0050] In this invention, the oxygen permeability coefficient can be measured under test conditions of 70°C and 0% RH. The specific measurement of the oxygen permeability coefficient can be performed using the methods described in the examples.

[0051] The preferred ethyl acetate permeability of the copolymer is 7.4 g·cm / m. 2 The following is more preferably 7.0 g·cm / m 2 The copolymers of the present invention exhibit excellent low permeability to ethyl acetate due to appropriate adjustments to the PPVE unit content, melt flow rate (MFR), and number of functional groups in copolymers containing TFE and PPVE units. In other words, by using the copolymers of the present invention, molded articles that are difficult for reagents such as ethyl acetate to permeate can be obtained.

[0052] In this invention, the ethyl acetate transmittance can be measured at 60°C for 45 days. The specific measurement of ethyl acetate transmittance can be performed using the methods described in the examples.

[0053] The copolymers of the present invention can be manufactured by polymerization methods such as suspension polymerization, solution polymerization, emulsion polymerization, and bulk polymerization. Emulsion polymerization or suspension polymerization is preferred as the polymerization method. In these polymerizations, conditions such as temperature and pressure, polymerization initiators, and other additives can be appropriately set according to the composition and amount of the copolymer.

[0054] Oil-soluble or water-soluble free radical polymerization initiators can be used as polymerization initiators.

[0055] Oil-soluble free radical polymerization initiators can be well-known oil-soluble peroxides, and the following substances can be cited as representative examples:

[0056] Dialkyl percarbonate esters, such as di-n-propyl percarbonate, diisopropyl percarbonate, disec-butyl percarbonate, and di-2-ethoxyethyl percarbonate;

[0057] Peroxide esters such as tert-butyl peroxide isobutyrate and tert-butyl perpentyl peroxide;

[0058] Dialkyl peroxides such as di-tert-butyl peroxide;

[0059] Di[fluoro(or fluorochloro)acyl] peroxides; etc.

[0060] Examples of diacyl peroxides include those represented by [(RfCOO)-]2 (where Rf is a perfluoroalkyl, ω-hydroperfluoroalkyl, or fluorochloroalkyl).

[0061] Examples of di[fluoro(or fluorochloro)acyl]peroxides include, for example, di(ω-hydro-dodecanoyl)peroxide, di(ω-hydro-tetradecanoyl)fluoroheptanoyl)peroxide, di(ω-hydro-hexadecanoyl)fluorononanoyl)peroxide, di(perfluoropropionyl)peroxide, di(perfluorobutyryl)peroxide, di(perfluoropentanoyl)peroxide, di(perfluorohexanoyl)peroxide, di(perfluoroheptanoyl)peroxide, di(perfluorooctanoyl)peroxide, di(perfluorononanoyl)peroxide, di(ω-chloro-hexafluorobutyryl)peroxide, and di... (ω-chloro-decafluorohexanoyl) peroxide, di(ω-chloro-tetrafluorooctanoyl) peroxide, ω-hydro-dodecanoheptafluorononanoyl-peroxide, ω-chloro-hexafluorobutyryl-ω-chloro-decafluorohexanoyl-peroxide, ω-hydro-dodecanoheptafluorobutyryl-perfluorobutyryl-peroxide, di(dichloropentafluorobutyryl) peroxide, di(trichlorooctafluorohexanoyl) peroxide, di(tetrachloroundecanoyl) peroxide, di(pentachlorotetrafluorodecanoyl) peroxide, di(undecachlorotetrafluorotetradecanoyl) peroxide, di(undecachlorotetrafluorotetradecanoyl) peroxide, etc.

[0062] Water-soluble free radical polymerization initiators can be well-known water-soluble peroxides, such as ammonium, potassium, and sodium salts of persulfate, perboric acid, perchloric acid, superphosphoric acid, and percarbonate; organic peroxides such as disuccinate peroxide and diglutaric acid peroxide; tert-butyl maleate peroxide; and tert-butyl hydroperoxide. Reducing agents such as sulfites can also be used in combination with peroxides, with the amount used relative to the peroxide ranging from 0.1 to 20 times.

[0063] In polymerization, surfactants, chain transfer agents, and solvents can be used, and previously known substances can be used respectively.

[0064] As the surfactant, known surfactants can be used, such as nonionic surfactants, anionic surfactants, and cationic surfactants. Among these, fluorinated anionic surfactants are preferred, and more preferably, fluorinated anionic surfactants with straight or branched chains having 4 to 20 carbon atoms, with or without ether-bonded oxygen (i.e., oxygen atoms can be inserted between carbon atoms). The amount of surfactant added (relative to the polymerization water) is preferably 50 ppm to 5000 ppm.

[0065] Examples of chain transfer agents include: hydrocarbons such as ethane, isopentane, n-hexane, and cyclohexane; aromatics such as toluene and xylene; ketones such as acetone; acetates such as ethyl acetate and butyl acetate; alcohols such as methanol and ethanol; thiols such as methyl mercaptan; and halogenated hydrocarbons such as carbon tetrachloride, chloroform, dichloromethane, and chloromethane. The amount of chain transfer agent added varies depending on the chain transfer constant of the compound used, and is typically used in the range of 0.01% to 20% by mass relative to the polymerization solvent.

[0066] Examples of solvents include water and mixed solvents of water and alcohol.

[0067] In suspension polymerization, fluorinated solvents can be used in addition to water. Examples of fluorinated solvents include hydrochlorofluorocarbons such as CH3CClF2, CH3CCl2F, CF3CF2CCl2H, and CF2ClCF2CFHCl; chlorofluorocarbons such as CF2ClCFClCF2CF3 and CF3CFClCFClCF3; hydrofluorocarbons such as CF3CFHCFHCF2CF2CF3, CF2HCF2CF2CF2CF2H, and CF3CF2CF2CF2CF2CF2CF2H; and CH3OC2F5, C Hydrofluoroethers such as H3OC3F5CF3CF2CH2OCHF2, CF3CHFCF2OCH3, CHF2CF2OCH2F, (CF3)2CHCF2OCH3, CF3CF2CH2OCH2CHF2, and CF3CHFCF2OCH2CF3; and perfluoroalkanes such as perfluorocyclobutane, CF3CF2CF2CF3, CF3CF2CF2CF2CF3, and CF3CF2CF2CF2CF2CF3, with perfluoroalkanes being preferred. From the perspectives of suspension performance and economy, the amount of fluorinated solvent relative to the aqueous medium is preferably 10% to 100% by mass.

[0068] There is no particular limitation on the polymerization temperature, which can be 0 to 100°C. The polymerization pressure is appropriately determined according to the type, amount, vapor pressure, polymerization temperature, and other polymerization conditions used, and is usually 0 to 9.8 MPaG.

[0069] When an aqueous dispersion containing a copolymer is obtained through polymerization, the copolymer can be recovered by precipitating it, washing, and drying. Alternatively, when a copolymer is obtained as a slurry through polymerization, the copolymer can be recovered by removing the slurry from the reaction vessel, washing, and drying. The copolymer can also be recovered as a powder by drying.

[0070] The copolymer obtained through polymerization can also be granulated. There are no particular limitations on the granulation method; existing known methods can be used. For example, methods such as using a single-screw extruder, twin-screw extruder, or tandem extruder to melt-extrude the copolymer and cut it to a specified length to form granules can be employed. The extrusion temperature during melt extrusion needs to be varied depending on the melt viscosity of the copolymer and the manufacturing method; preferably, it is between the copolymer's melting point +20°C and the copolymer's melting point +140°C. There are no particular limitations on the copolymer cutting method; existing known methods such as wire cutting, thermal cutting, underwater cutting, and sheet cutting can be used. The volatile components in the granules can also be removed by heating (degassing treatment). Alternatively, the granules can be treated by contacting them with warm water at 30°C to 200°C, steam at 100°C to 200°C, or hot air at 40°C to 200°C.

[0071] The copolymer obtained by polymerization can also be fluorinated. Fluorination can be carried out by contacting the unfluorinated copolymer with a fluorinated compound. Through fluorination, thermally unstable functional groups such as -COOH, -COOCH3, -CH2OH, -COF, -CF=CF2, and -CONH2, as well as relatively thermally stable functional groups such as -CF2H, can be converted into extremely thermally stable -CF3. As a result, the total number of functional groups (-COOH, -COOCH3, -CH2OH, -COF, -CF=CF2, -CONH2, and -CF2H) of the copolymer can be easily adjusted to the above-mentioned range.

[0072] There are no particular limitations on fluorine-containing compounds; examples of fluorine radical sources that generate fluorine radicals under fluorination conditions can be cited. Examples of such fluorine radical sources include F2 gas, CoF3, AgF2, UF6, OF2, N2F2, CF3OF, and fluorinated halogens (e.g., IF5, ClF3).

[0073] Fluorine radical sources such as F2 gas can be 100% concentrated, but from a safety perspective, it is preferable to mix them with an inert gas and dilute them to 5% to 50% by mass before use, and more preferably to 15% to 30% by mass. Examples of such inert gases include nitrogen, helium, and argon; from an economic perspective, nitrogen is preferred.

[0074] The conditions for fluorination are not particularly limited; the molten copolymer can be brought into contact with a fluorinated compound. However, it is generally carried out at a temperature below the melting point of the copolymer, preferably between 20°C and 240°C, and more preferably between 100°C and 220°C. The fluorination treatment is typically carried out for 1 hour to 30 hours, preferably 5 hours to 25 hours. Fluorination is preferably carried out by bringing the unfluorinated copolymer into contact with fluorine gas (F2 gas).

[0075] The copolymers of the present invention can also be mixed with other components as needed to obtain compositions. Examples of other components include fillers, plasticizers, processing aids, mold release agents, pigments, flame retardants, lubricants, light stabilizers, weather stabilizers, conductive agents, antistatic agents, ultraviolet absorbers, antioxidants, foaming agents, fragrances, oils, softeners, defluorinated hydrogen agents, etc.

[0076] Examples of fillers include silica, kaolin, clay, organoclay, talc, mica, alumina, calcium carbonate, calcium terephthalate, titanium dioxide, calcium phosphate, calcium fluoride, lithium fluoride, cross-linked polystyrene, potassium titanate, carbon, boron nitride, carbon nanotubes, and glass fiber. Examples of conductive agents include carbon black. Examples of plasticizers include dioctyl phthalate and pentaerythritol. Examples of processing aids include carnauba wax, sulfone compounds, low molecular weight polyethylene, and fluorinated additives. Examples of defluorinating agents include organonium and amidines.

[0077] Other polymers besides the copolymers described above can also be used as other components. Examples of other polymers include fluoropolymers, fluororubbers, and non-fluorinated polymers.

[0078] Examples of methods for manufacturing the above composition include: dry mixing of the copolymer with other components; pre-mixing of the copolymer with other components using a mixer, followed by melt mixing using a kneader, melt extruder, etc.; etc.

[0079] The copolymers of the present invention or the above-described compositions can be used as processing aids, molding materials, etc., and are preferably used as molding materials. Aqueous dispersions, solutions, suspensions, and copolymer / solvent systems of the copolymers of the present invention can also be used as coatings, or for encapsulation, impregnation, and film casting. However, the copolymers of the present invention have the above-described properties, and therefore are preferably used as the above-described molding materials.

[0080] The copolymer of the present invention or the above composition can also be molded to obtain a molded body.

[0081] The method for molding the above-mentioned copolymer or composition is not particularly limited, and examples include compression molding, transfer molding, extrusion molding, blow molding, rotational molding, and roll forming. As molding methods, compression molding, extrusion molding, transfer molding, or blow molding are preferred, extrusion molding, transfer molding, or blow molding are more preferred, and blow molding is even more preferred. That is, as the molded body, a compression molded body, an extrusion molded body, a transfer molded body, or a blow molded body is preferred, and an extrusion molded body, transfer molded body, or blow molded body is more preferred.

[0082] The molded body containing the copolymer of the present invention can be, for example, a nut, bolt, joint, membrane, bottle, gasket, wire sheath, tube, hose, pipe, valve, sheet, seal, gasket, can, roller, container, stopcock, connector, filter housing, filter cover, flow meter, pump, wafer carrier, wafer box, etc.

[0083] The copolymers, compositions, or molded articles of the present invention can be used for, for example, the following purposes.

[0084] Food packaging films, lining materials for fluid transport pipelines used in food manufacturing processes, gaskets, sealing materials, thin sheets, and other fluid transport components for food manufacturing equipment;

[0085] Chemical stoppers, packaging films, lining materials for fluid delivery pipelines used in chemical manufacturing processes, gaskets, sealing materials, thin plates, and other reagent delivery components;

[0086] Inner lining components for reagent containers and piping in chemical equipment and semiconductor plants;

[0087] O-rings / pipes / gaskets, valve core materials, hoses, sealing materials, etc. used in the fuel system and peripheral devices of automobiles; hoses, sealing materials, and other fuel delivery components used in the AT system of automobiles.

[0088] The carburetor flange gaskets, shaft seals, valve stem seals, sealing materials, hoses, etc. used in the engine and peripheral devices of automobiles; brake hoses, air conditioning hoses, radiator hoses, wire sheathing materials, and other automobile components.

[0089] O-rings, tubes, gaskets, valve core materials, hoses, sealing materials, rollers, washers, diaphragms, connectors and other reagent delivery components for semiconductor manufacturing equipment;

[0090] Coating and ink components for coating equipment, such as coating rollers, hoses, tubes, and ink containers;

[0091] Food and beverage conduits, hoses, belts, gaskets, connectors and other food and beverage conveying components, food packaging materials, and glass cooking equipment;

[0092] Pipes, hoses, and other components used for waste liquid transportation;

[0093] Pipes, hoses, and other components used for high-temperature liquid transfer;

[0094] Pipes, hoses and other components used in steam piping;

[0095] Corrosion-resistant tape for piping, such as tape wrapped around the piping on the deck of a ship;

[0096] Various coating materials, such as wire coating materials, optical fiber coating materials, transparent surface coating materials and backing agents applied to the light incident side of photovoltaic elements in solar cells;

[0097] The diaphragm and various sliding components such as gaskets in a diaphragm pump;

[0098] Weather-resistant covers for agricultural films, various roofing materials, and sidewalls;

[0099] Interior materials used in the construction industry, and glass-like covering materials such as non-combustible fire-resistant safety glass;

[0100] Lining materials such as laminated steel sheets used in the home appliance industry.

[0101] Further examples of fuel delivery components used in the fuel systems of the aforementioned automobiles include fuel hoses, filler hoses, and evaporator hoses. These fuel delivery components can also be used for fuels resistant to acidic gasoline, alcohol-based fuels, and fuels containing gasoline additives such as those resistant to methyl tert-butyl ether and amines.

[0102] The stoppers and packaging films used for the aforementioned chemicals exhibit excellent resistance to acids and other chemicals. Additionally, anti-corrosion tape wrapped around the piping of chemical equipment can also be cited as a component for transporting the aforementioned reagents.

[0103] Examples of such molded bodies include radiator water chambers for automobiles, reagent tanks, bellows, partitions, rollers, gasoline tanks, waste liquid conveying containers, high-temperature liquid conveying containers, and fish farming and aquaculture tanks.

[0104] Further examples of the molded bodies mentioned above include components used in automobile bumpers, door panels, dashboards, food processing devices, cooking machines, waterproof and oil-proof glass, lighting-related instruments, indicator panels and housings of OA instruments, electrically illuminated signboards, displays, LCD screens, mobile phones, printer chassis, electrical and electronic components, groceries, trash cans, bathtubs, prefabricated bathrooms, exhaust fans, lighting frames, etc.

[0105] The molded articles containing the copolymer of the present invention have excellent wear resistance, low oxygen permeability, low reagent permeability, creep resistance and rigidity at high temperature of 110°C, and do not easily cause fluoride ions to dissolve into reagents such as hydrogen peroxide. Therefore, they are suitable for use in nuts, bolts, joints, gaskets, valves, stopcocks, connectors, filter housings, filter covers, flow meters, pumps, etc.

[0106] Molded articles containing the copolymers of the present invention exhibit excellent wear resistance, low oxygen permeability, low reagent permeability, creep resistance, and rigidity at high temperatures of 110°C. They are also less prone to fluoride ion dissolution into reagents such as hydrogen peroxide, making them suitable for use as gaskets, sealing gaskets, and other compressed components.

[0107] The compressed component of the present invention exhibits excellent creep resistance. The compressed component of the present invention can be used under compression deformation at a compression rate of 10% or more, and can be used under compression deformation at a compression rate of 20% or more, or 25% or more. By using the compressed component of the present invention under such high compression deformation rates, it can maintain a certain degree of resilience over a long period, and can maintain sealing and insulation properties over a long period.

[0108] The compressed component of the present invention exhibits excellent creep resistance even when used at high temperatures. The compressed component of the present invention can be used at temperatures above 80°C with a compression deformation rate of 10% or more, and at temperatures above 80°C with a compression deformation rate of 20% or 25% or more. By using the compressed component of the present invention at such high temperatures with a high compression deformation rate, it can maintain a certain degree of resilience even at high temperatures for a long period, and can maintain its sealing and insulation properties at high temperatures for an extended period.

[0109] Regarding the aforementioned compressive deformation rate, when the compressed member is used in a compressed state, it is the compressive deformation rate of the part with the largest compressive deformation rate. For example, when a flat compressed member is used in a state where it is compressed along its thickness direction, it is the compressive deformation rate in the thickness direction. Furthermore, for example, when the compressed member is used in a state where only a portion of it is compressed, it is the compressive deformation rate of the part with the largest compressive deformation rate among the compressed portions.

[0110] The size and shape of the compressed member of the present invention can be appropriately set according to the application and are not particularly limited. The shape of the compressed member of the present invention can be, for example, ring-shaped. In addition, the compressed member of the present invention can have a circular, elliptical, or quadrilateral shape with rounded corners when viewed from above, and has a through hole in its central part.

[0111] The compressed member of the present invention is preferably used as a component for constructing a non-aqueous electrolyte battery. The compressed member of the present invention may have a liquid-contacting surface with the non-aqueous electrolyte in the non-aqueous electrolyte battery.

[0112] As for non-aqueous electrolyte batteries, there are no particular limitations as long as the battery contains a non-aqueous electrolyte; examples include lithium-ion secondary batteries and lithium-ion capacitors. Furthermore, components constituting non-aqueous electrolyte batteries include sealing components and insulating components.

[0113] The non-aqueous electrolyte is not particularly limited and can be one or more of the following known solvents: propylene carbonate, ethylene carbonate, butyl carbonate, γ-butyrolactone, 1,2-dimethoxyethane, 1,2-diethoxyethane, dimethyl carbonate, diethyl carbonate, and methyl ethyl carbonate. The non-aqueous electrolyte battery may further include an electrolyte. The electrolyte is not particularly limited and can be LiClO4, LiAsF6, LiPF6, LiBF4, LiCl, LiBr, CH3SO3Li, CF3SO3Li, cesium carbonate, etc.

[0114] The compressed component of the present invention can preferably be used as a sealing component such as a sealing gasket or sealing pad, or as an insulating component such as an insulating gasket or insulating sealing pad. A sealing component is used to prevent leakage of liquid or gas or intrusion of liquid or gas from the outside. An insulating component is used for electrical insulation. The compressed component of the present invention can also be used for both sealing and insulation purposes.

[0115] The compressed component of the present invention exhibits excellent creep resistance even when used at high temperatures, and therefore can be used appropriately in high-temperature environments. For example, the compressed component of the present invention is preferably used in environments with a maximum temperature of 40°C or higher. For example, the compressed component of the present invention is suitable for use in environments with a maximum temperature of 80°C or higher. Examples of situations where the compressed component of the present invention can withstand such high temperatures include, for example, the case where other battery components are installed in the battery by welding after the compressed component is installed in a compressed state; the case where a non-aqueous electrolyte battery generates heat; etc.

[0116] The compressible member of the present invention exhibits excellent creep resistance even when used at high temperatures, making it suitable for use as a sealing member or insulating member for non-aqueous electrolyte batteries. For example, during charging of batteries such as non-aqueous electrolyte secondary batteries, the battery temperature may temporarily exceed 40°C, and particularly exceed 80°C. The compressible member of the present invention, even when deformed at high compression rates in batteries such as non-aqueous electrolyte secondary batteries at high temperatures, does not compromise its high resilience even when in contact with non-aqueous electrolytes at high temperatures. Therefore, when the compressible member of the present invention is used as a sealing member, it exhibits excellent sealing properties, which are maintained for extended periods even at high temperatures. Furthermore, the compressible member of the present invention, containing the aforementioned copolymer, possesses excellent insulating properties. Therefore, when the compressible member of the present invention is used as an insulating member, it provides a strong seal with two or more conductive members, preventing short circuits for extended periods.

[0117] The copolymer of the present invention, when formed using an extrusion molding method, can form a thick coating layer of uniform thickness on core wires with very large diameters, thus making it suitable for use as a material for forming wire coatings. The outer diameter of the coated wire having a coating layer containing the copolymer of the present invention remains almost unchanged, resulting in excellent electrical properties.

[0118] To form a thick coating of uniform thickness on a core wire with a very large diameter, time is required for the molten coating to solidify, and the coating is also heavy. Therefore, when using existing copolymers, the coating deforms due to its own weight before solidification, making it difficult to form a coating of uniform thickness. By using the copolymer of the present invention, a thick coating of uniform thickness can be formed.

[0119] The coated wire has a core wire and a coating layer disposed around the core wire containing the copolymer of the present invention. For example, an extruded body formed by melt-extruding the copolymer of the present invention onto the core wire can be used as the coating layer. The coated wire is suitable for LAN cables (Eathernet cables), high-frequency transmission cables, flat cables, heat-resistant cables, etc., and is particularly suitable for transmission cables such as LAN cables (Eathernet cables) and high-frequency transmission cables.

[0120] For example, copper, aluminum, or other metallic conductors can be used as the core wire material. The core wire diameter is preferably 0.02 mm to 3 mm. More preferably, the core wire diameter is 0.04 mm or more, even more preferably 0.05 mm or more, and particularly preferably 0.1 mm or more. Even more preferably, the core wire diameter is 2 mm or less.

[0121] Specific examples of core wires include AWG (American wire gauge)-46 (solid copper wire with a diameter of 40μm), AWG-26 (solid copper wire with a diameter of 404μm), AWG-24 (solid copper wire with a diameter of 510μm), and AWG-22 (solid copper wire with a diameter of 635μm).

[0122] The thickness of the coating layer is preferably 0.1 mm to 3.0 mm. The thickness of the coating layer is also preferably less than 2.0 mm.

[0123] Coaxial cables are an example of high-frequency transmission cables. Coaxial cables typically have a structure consisting of an inner conductor, an insulating sheath, an outer conductor layer, and a protective sheath layer layered sequentially from the core to the outer periphery. Molded bodies containing the copolymer of the present invention can be suitable as the insulating sheath layer containing the copolymer. The thickness of each layer in the above structure is not particularly limited; typically, the diameter of the inner conductor is about 0.1 mm to 3 mm, the thickness of the insulating sheath is about 0.3 mm to 3 mm, the thickness of the outer conductor layer is about 0.5 mm to 10 mm, and the thickness of the protective sheath is about 0.5 mm to 2 mm.

[0124] The coating may contain air bubbles, which are preferably evenly distributed in the coating.

[0125] The average bubble diameter is not limited, but is preferably 60 μm or less, more preferably 45 μm or less, further preferably 35 μm or less, even more preferably 30 μm or less, particularly preferably 25 μm or less, and especially preferably 23 μm or less. Furthermore, the average bubble diameter is preferably 0.1 μm or more, more preferably 1 μm or more. The average bubble diameter can be obtained by acquiring an electron microscope image of the wire cross-section, calculating the diameter of each bubble using image processing, and then averaging the results.

[0126] The foaming rate of the coating layer can be 20% or more. More preferably, it is 30% or more, further preferably 33% or more, and even more preferably 35% or more. There is no particular upper limit, for example, 80%. The upper limit of the foaming rate can also be 60%. The foaming rate is calculated as ((specific gravity of wire coating material - specific gravity of coating layer) / specific gravity of wire coating material) × 100. The foaming rate can be adjusted appropriately according to the application, for example, by adjusting the gas insertion amount in the extruder described later, or by selecting the type of dissolved gas.

[0127] The coated wire may also have other layers between the core wire and the coating layer, and may further have other layers (outer layers) around the coating layer. If the coating layer contains air bubbles, the wire of the present invention may also be a two-layer structure (skin-foam body) with a non-foamed layer inserted between the core wire and the coating layer; a two-layer structure (foam body-skin body) with a non-foamed layer coated on the outer layer; and a three-layer structure (skin-foam body-skin body) with a non-foamed layer coated on the outer layer of the skin-foam body. The non-foamed layer is not particularly limited and may be a resin layer composed of TFE / HFP copolymers, TFE / PAVE copolymers, TFE / ethylene copolymers, vinylidene fluoride polymers, polyolefin resins such as polyethylene [PE], and resins such as polyvinyl chloride [PVC].

[0128] Coated wires can be manufactured, for example, by heating a copolymer using an extruder and extruding it onto the core wire while the copolymer is in a molten state to form a coating.

[0129] During the formation of the coating layer, the copolymer can also be heated, and gas can be introduced into the copolymer while it is in a molten state to form the aforementioned coating layer containing bubbles. The gas can be, for example, dichlorofluoromethane, nitrogen, carbon dioxide, or a mixture of these gases. The gas can be introduced into the heated copolymer in the form of pressurized gas, or it can be generated by mixing a chemical foaming agent into the copolymer. The gas dissolves in the molten copolymer.

[0130] In addition, the copolymers of the present invention are suitable for use as materials in products for high-frequency signal transmission.

[0131] As for the aforementioned high-frequency signal transmission products, there are no particular limitations as long as the product is used for high-frequency signal transmission. Examples include (1) insulating boards for high-frequency circuits, insulating materials for connecting components, printed wiring boards, and other molded boards; (2) bases for high-frequency vacuum tubes, radomes, and other molded bodies; and (3) sheathed wires such as coaxial cables and LAN cables. The aforementioned high-frequency signal transmission products are suitable for use in satellite communication equipment, mobile phone base stations, and other equipment that utilizes microwaves, especially microwaves from 3 GHz to 30 GHz.

[0132] In the aforementioned high-frequency signal transmission products, the copolymer of the present invention, from the perspective of low dielectric loss tangent, can be suitable for use as an insulator.

[0133] As for the molded plate described in (1) above, a printed wiring substrate is preferred from the perspective of obtaining good electrical characteristics. There are no particular limitations on the printed wiring substrate described above; examples include printed wiring substrates for electronic circuits in mobile phones, various computers, and communication devices. As for the molded body described in (2) above, an antenna radome is preferred from the perspective of low dielectric loss.

[0134] The copolymer of the present invention can be easily formed into a film of uniform thickness by extrusion molding. The molded body containing the copolymer of the present invention is suitable for use as a film or sheet.

[0135] The film of the present invention is useful as a release film. The release film can be manufactured by molding the copolymer of the present invention through melt extrusion molding, calendering, compression molding, casting, etc. From the perspective of obtaining a uniform film, the release film can be manufactured by melt extrusion molding.

[0136] The membrane of this invention can be applied to the surface of rollers used in OA equipment. Furthermore, the copolymer of this invention can be molded into necessary shapes, such as sheets, films, or tubes, through extrusion molding, compression molding, or pressing, for use as a surface material for OA equipment rollers or belts. In particular, thin-walled tubes and membranes can be manufactured using melt extrusion molding.

[0137] The molded articles containing the copolymers of the present invention exhibit excellent wear resistance, low oxygen permeability, low reagent permeability, creep resistance, and rigidity at 110°C. They also do not readily leach fluoride ions into reagents such as hydrogen peroxide, making them suitable for use as bottles or tubes. Furthermore, the copolymers of the present invention can be easily blow-molded into hollow molded articles. Therefore, molded articles containing the copolymers of the present invention are preferably blow-molded articles or blow-molded bottles.

[0138] The embodiments have been described above, but it is understood that various changes can be made to the methods and details without departing from the spirit and scope of the claims.

[0139] Example

[0140] Next, embodiments will be given to illustrate the implementation of the present invention, but the present invention is not limited to the embodiments described.

[0141] The values ​​in the examples were measured using the following methods.

[0142] (Monomer content)

[0143] The content of each monomer unit was determined by an NMR analyzer (e.g., an AVANCE300 high-temperature probe manufactured by Bruker BioSpin).

[0144] (Mel flow rate (MFR))

[0145] According to ASTM D1238, the mass (g / 10 min) of polymer flowing out of a nozzle with an inner diameter of 2.1 mm and a length of 8 mm per 10 minutes was determined using a melt indexer G-01 (manufactured by Toyo Seiki Co., Ltd.) at 372°C and a load of 5 kg.

[0146] (Number of functional groups)

[0147] The copolymer granules were cold-pressed to produce films with a thickness of 0.25 mm to 0.3 mm. The films were then scanned 40 times using a Fourier transform infrared spectroscopy (FT-IR) device (Spectrum One, PerkinElmer) to obtain infrared absorption spectra. A differential spectrum was obtained between this spectrum and the background spectrum of the fully fluorinated film, which lacks functional groups. The concentration of the sample relative to each 1 × 10⁻⁶ functional group was calculated from the absorption peaks of specific functional groups observed in the differential spectrum according to the following formula (A). 6 The number of functional groups N per carbon atom.

[0148] N = I × K / t(A)

[0149] I: Absorbance

[0150] K: Correction coefficient

[0151] t: Membrane thickness (mm)

[0152] For reference, the absorption frequencies, molar absorptivity, and correction factors for the functional groups in this invention are shown in Table 2. The molar absorptivity was determined by FT-IR measurements of the low-molecular-weight model compounds.

[0153] [Table 2]

[0154] Table 2

[0155]

[0156] (Melting point)

[0157] The first heating was performed using a differential scanning calorimeter (trade name: X-DSC7000, manufactured by Hitachi High-Tech Science) at a heating rate of 10°C / min, from 200°C to 350°C. Then, the temperature was cooled from 350°C to 200°C at a cooling rate of 10°C / min. The second heating was performed again at a heating rate of 10°C / min, from 200°C to 350°C. The melting point was determined from the peak value of the melting curve generated during the second heating process.

[0158] Comparative Example 1

[0159] 51.8 L of pure water was added to a 174 L autoclave, and after thorough nitrogen purging, 40.9 kg of perfluorocyclobutane, 2.43 kg of perfluoropropyl vinyl ether (PPVE), and 0.84 kg of methanol were added. The system temperature was maintained at 35 °C, and the stirring speed was maintained at 200 rpm. Next, tetrafluoroethylene (TFE) was injected to 0.64 MPa, followed by 0.026 kg of a 50% methanol solution of di-n-propyl peroxide dicarbonate, initiating polymerization. Since the pressure within the system decreased as polymerization progressed, TFE was continuously supplied to maintain a constant pressure, with an additional 0.053 kg of PPVE added for every 1 kg of TFE supplied. Polymerization was terminated when the additional TFE amount reached 40.9 kg. Unreacted TFE was released, and the autoclave pressure was restored to atmospheric pressure. The resulting reaction product was washed with water and dried to obtain 43.1 kg of powder.

[0160] The obtained powder was melt-extruded at 360°C using a screw extruder (trade name: PCM46, manufactured by Ikebe Co., Ltd.) to obtain TFE / PPVE copolymer granules. The PPVE content of the obtained granules was determined using the method described above.

[0161] The obtained granules were placed in a VVD-30 vacuum vibratory reactor (manufactured by Okawahara Seisakusho Co., Ltd.) and heated to 210°C. After evacuation, F2 gas diluted to 20% by volume with N2 gas was introduced to atmospheric pressure. 0.5 hours after the introduction of F2 gas, the reactor was temporarily evacuated, and F2 gas was introduced again. This process was repeated 0.5 hours later, followed by another evacuation and introduction of F2 gas. This process of introducing F2 gas and evacuating the reactor was repeated once every hour, and the reaction was carried out at 210°C for 10 hours. After the reaction was completed, the reactor was completely replaced with N2 gas to stop the fluorination reaction. Various physical properties of the fluorinated granules were measured using the above method.

[0162] Comparative Example 2

[0163] The amount of PPVE was changed to 2.37 kg, the amount of methanol was changed to 2.79 kg, and the amount of PPVE was changed to an additional 0.052 kg for every 1 kg of TFE supplied, resulting in 43.0 kg of dry powder. Otherwise, unfluorinated granules were obtained in the same manner as in Comparative Example 1.

[0164] Comparative Example 3

[0165] The amount of PPVE was changed to 2.53 kg, the amount of methanol was changed to 3.42 kg, and the amount of PPVE was changed to an additional 0.055 kg for every 1 kg of TFE supplied, resulting in 41.0 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Comparative Example 1.

[0166] Comparative Example 4

[0167] The amount of PPVE was changed to 1.53 kg, the amount of methanol was changed to 4.55 kg, and the amount of PPVE was changed to an additional 0.037 kg for every 1 kg of TFE supplied, resulting in 42.4 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Comparative Example 1.

[0168] Comparative Example 5

[0169] The amount of PPVE was changed to 3.21 kg, the amount of methanol was changed to 0.62 kg, and the amount of PPVE was changed to 0.066 kg added for every 1 kg of TFE supplied, resulting in 43.6 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Comparative Example 1.

[0170] Example 1

[0171] The amount of PPVE was changed to 1.85 kg, the amount of methanol was changed to 3.10 kg, and the amount of PPVE was changed to 0.043 kg added for every 1 kg of TFE supplied, resulting in 42.6 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Comparative Example 1.

[0172] Example 2

[0173] The amount of PPVE was changed to 2.05 kg, the amount of methanol was changed to 2.80 kg, and the amount of PPVE was changed to an additional 0.046 kg for every 1 kg of TFE supplied, resulting in 42.8 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Comparative Example 1.

[0174] Example 3

[0175] The amount of PPVE was changed to 2.24 kg, the amount of methanol was changed to 2.72 kg, and the amount of PPVE was changed to 0.049 kg added for every 1 kg of TFE supplied, resulting in 42.9 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Comparative Example 1.

[0176] Example 4

[0177] The amount of PPVE was changed to 2.43 kg, the amount of methanol was changed to 2.63 kg, and the amount of PPVE was changed to 0.053 kg added for every 1 kg of TFE supplied, resulting in 43.1 kg of dry powder. Otherwise, fluorinated granules were obtained in the same manner as in Comparative Example 1.

[0178] Using the granules obtained in the examples and comparative examples, various physical properties were determined by the methods described above. The results are shown in Table 3.

[0179] [Table 3]

[0180] Table 3

[0181]

[0182] The “<6” in Table 3 refers to the number of functional groups being less than 6.

[0183] Next, the obtained granules were used to evaluate the following properties. The results are shown in Table 4.

[0184] (Abrasion test)

[0185] Using a granulation and hot-press molding machine, sheet-like test pieces with a thickness of approximately 0.2 mm were prepared, from which 10 cm × 10 cm test pieces were cut. The prepared test pieces were fixed on the test bench of a Tiber abrasion testing machine (No. 101 Special Type Tiber Abrasion Testing Machine, manufactured by Yasuda Seiki Co., Ltd.). Abrasion tests were conducted using the Tiber abrasion testing machine under the following conditions: temperature 25°C, load 500 g, abrasion wheel CS-10 (grinding with #240 abrasive paper 20 times), and rotation speed 60 rpm. The weight of the test piece was measured after 1000 revolutions, and the same test piece was further tested after 10000 revolutions, and the weight of the test piece was measured again. The amount of abrasion was calculated using the following formula.

[0186] Wear amount (mg) = M1 - M2

[0187] M1: Weight of the test piece after 1000 revolutions (mg)

[0188] M2: Weight of the test piece (mg) after 10,000 revolutions.

[0189] (Oxygen permeability coefficient)

[0190] Using granulation and a hot press molding machine, sheet-like test pieces with a thickness of approximately 0.1 mm were prepared. Using the obtained test pieces, the oxygen permeability was measured using a differential pressure gas permeability meter (L100-5000 type gas permeability meter, manufactured by Systech Illinois) according to the method described in JIS K7126-1:2006. The resulting permeability area was 50.24 cm². 2 The oxygen permeability was measured at a test temperature of 70℃ and a test humidity of 0%RH. Using the obtained oxygen permeability and the thickness of the test piece, the oxygen permeability coefficient was calculated using the following formula.

[0191] Oxygen permeability (cm) 3 ·mm / (m 2 ·24h·atm))=GTR×d

[0192] GTR: Oxygen permeability (cm) 3 / (m 2 ·24h·atm))

[0193] d: Test piece thickness (mm)

[0194] (Ethyl acetate permeability)

[0195] Using granulation and a thermoforming machine, sheet-like test pieces with a thickness of approximately 0.1 mm were produced. These were then placed in a test cup (with a transparency area of ​​12.56 cm²). 2 Add 10g of ethyl acetate to the solution, cover with a test sheet, and secure with a PTFE gasket. Ensure the test sheet is in contact with the ethyl acetate. After maintaining the solution at 60℃ for 45 days, remove the test sheet and allow it to stand at room temperature for 1 hour to measure the mass loss. Calculate the ethyl acetate transmittance (g·cm / m) using the following formula. 2 ).

[0196] Ethyl acetate (g·cm / m 2 = Mass reduction (g) × Thickness of sheet test piece (cm) / Transmitting area (m²) 2 )

[0197] (Creep Resistance Evaluation)

[0198] Creep resistance was determined according to the methods described in ASTM D395 or JIS K6262:2013. A 13mm outer diameter and 8mm height molded body was prepared using granulation and a hot press. Test pieces with an outer diameter of 13mm and a height of 6mm were fabricated by cutting the molded body. The test pieces were compressed at room temperature to a compression set of 25% using a compression device. The compressed test pieces were then placed in an electric furnace at 80°C for 72 hours while still attached to the compression device. After removing the compression device from the furnace and cooling to room temperature, the test pieces were removed. The recovered test pieces were left at room temperature for 30 minutes, and their height was measured. The recovery ratio was calculated using the following formula.

[0199] Recovery rate (%) = (t2 - t1) / t3 × 100

[0200] t1: Height of the spacer (mm)

[0201] t2: Height of the test piece removed from the compression device (mm)

[0202] t3: Height after compression deformation (mm)

[0203] In the above experiment, t1 = 4.5 mm and t3 = 1.5 mm.

[0204] (Deflection under load at 110℃)

[0205] Using granulation and a hot press, sheet-like test pieces with a thickness of approximately 4.2 mm were prepared. 80 × 10 mm test pieces were cut from these pieces and heated in an electric furnace at 100°C for 20 hours. In addition to using the obtained test pieces, tests were conducted according to the method described in JIS K-K7191-1 using a heat distortion tester (manufactured by Yasuda Seiki Co., Ltd.) under the conditions of a test temperature of 30°C to 150°C, a heating rate of 120°C / hour, a bending stress of 1.8 MPa, and the flatwise method. The load deflection was calculated using the following formula. Sheets with low load deflection at 110°C exhibit excellent rigidity at this high temperature.

[0206] Load-induced deflection (%) = a2 / a1 × 100

[0207] a1: Thickness of the test piece before the test (mm)

[0208] a2: Deflection at 110℃ (mm)

[0209] (Extrusion pressure)

[0210] Extrusion pressure was measured using a RHEOGRAPH 25 dual capillary rheometer (manufactured by Goettfert). A main die inner diameter of 1 mm, L / D = 16, and a secondary die inner diameter of 1 mm, L / D < 1 were used. The test conditions were: a measurement temperature of 390°C, a residual heat time of 10 minutes after pellet feeding, and a shear rate of 20 sec. -1 The barrel pressure value after 10 minutes of extrusion is Bagley corrected and used as the extrusion pressure. Copolymers with low extrusion pressure exhibit excellent extrusion molding properties, injection molding properties, and other molding characteristics.

[0211] (Deformation test due to self-weight during melting)

[0212] Using granulation and a thermoforming machine, molded bodies with a diameter of 13 mm and a height of approximately 6.5 mm were produced. The resulting molded bodies were then cut to create test pieces with a height of 6.3 mm. The test pieces were placed in SUS (Sulfated Ultrasonic Flask) dishes and heated in an electric furnace at 330°C for 30 minutes. The dishes containing the test pieces were then water-cooled. The diameter of the bottom surface of the removed test piece was measured using vernier calipers, and the increase in bottom area was calculated using the following formula.

[0213] Bottom area increase rate (%) = {bottom area of ​​the test piece after heating (mm²)} 2 - Bottom area of ​​the test piece before heating (mm²) 2 )} / Bottom area of ​​the test piece before heating (mm²) 2 )×100

[0214] A lower base area increase rate means that the molded body is less likely to deform under its own weight when melted. Copolymers that provide molded bodies with a low base area increase rate are superior in that even when the copolymer is molded into thick sheets or large tubes by extrusion molding, the molded body in the molten state is not easily deformed, and the molded body obtains the desired shape after cooling and solidification.

[0215] (Hydrogen peroxide immersion test)

[0216] 25g of granules were immersed in 50g of a 3% (w / w) hydrogen peroxide solution, heated in an electric furnace at 90°C for 20 hours, then sterilized in a sterilizer at 121°C for 1 hour, and cooled to room temperature. The granules were removed from the aqueous solution, and TISAB solution (10) (manufactured by Kanto Chemical Co., Ltd.) was added to the remaining aqueous solution. The concentration of fluoride ions in the resulting aqueous solution was measured using a fluoride ion meter. The concentration of fluoride ions per unit weight of granules (amount of fluoride ions dissolved) was calculated from the measured values ​​according to the following formula.

[0217] Dissolved fluoride ion content (ppm by mass) = Measured value (ppm by mass) × Aqueous solution volume (g) / Granule weight (g)

[0218] (Membrane forming properties)

[0219] use An extruder (manufactured by Imoto Manufacturing Co., Ltd.) and a T-die are used to shape the granules into a film. The extrusion molding conditions are as follows.

[0220] a) Winding speed: 0.4 m / min

[0221] b) Roller temperature: 120℃

[0222] c) Membrane width: 70mm

[0223] d) Thickness: 0.25mm

[0224] e) Extrusion conditions:

[0225] • Single-screw extrusion molding machine with a barrel shaft diameter of 14mm and an L / D ratio of 20

[0226] Extruder set temperatures: Barrel section C-1 (330℃), Barrel section C-2 (350℃), Barrel section C-3 (370℃), T-die head (380℃)

[0227] The copolymer extrusion molding continues until the copolymer is stably extruded from the molding machine. Next, a film with a length of 5 m or more (70 mm wide) is produced by extruding the copolymer to a thickness of 0.25 mm. A 4-5 m section is cut from the end of the obtained film to prepare a test piece (1 m long, 70 mm wide) for measuring thickness variation. The thickness is measured at three locations: the center point in the width direction at the end of the film and two locations 25 mm away from that center point in the width direction. Furthermore, the thickness is measured at nine locations: three center points spaced 25 cm apart from the center point at one end of the film towards the other end, and two locations 25 mm away from each center point in the width direction. Of the total 12 measurements, those with 1 or fewer measurements outside the ±10% range of 0.25 mm are designated as ○, and those with 2 or more measurements outside the ±10% range of 0.25 mm are designated as ×.

[0228] (Wire Covering Test)

[0229] use A wire coating molding machine (manufactured by Tanabe Plastics Machinery Co., Ltd.) extrudes a coating copolymer onto a copper conductor with a conductor diameter of 1.00 mm to obtain a coated wire at the following coating thickness. The wire coating extrusion molding conditions are as follows.

[0230] a) Core conductor: Conductor diameter 1.00mm

[0231] b) Coating thickness: 0.50mm

[0232] c) Diameter of the covered wire: 2.00mm

[0233] d) Wire pulling speed: 7m / minute

[0234] e) Extrusion conditions:

[0235] • Single-screw extruder with a barrel diameter of 20mm and an L / D ratio of 22

[0236] • Mold (inner diameter) / Sheet (outer diameter) = 30.0mm / 10.0mm

[0237] Extruder set temperatures: Barrel section C-1 (330℃), Barrel section C-2 (360℃), Barrel section C-3 (375℃), Head H (390℃), Die head D-1 (405℃), Die head D-2 (395℃). Core wire preheating is set to 80℃.

[0238] (Changes in outer diameter)

[0239] The outer diameter of the coated wire was measured continuously for one hour using an outer diameter measuring instrument (Zumbach ODAC18XY). The outer diameter value was rounded to three decimal places from the maximum deviation from the specified outer diameter value (2.00 mm), thus determining the variation in outer diameter. The ratio of the absolute value of the difference between the specified outer diameter and the variation in outer diameter to the specified outer diameter (2.00 mm) (the rate of change in outer diameter) was calculated and evaluated according to the following criteria.

[0240] (Rate of change in outer diameter (%)) = |(Change in outer diameter) - (Specified outer diameter)| / (Specified outer diameter) × 100

[0241] ±1%: The variation rate of the outer diameter is less than 1%.

[0242] ±2%: The rate of change in outer diameter exceeds 1% but is less than 2%.

[0243] ×: The rate of change in outer diameter exceeds 2%.

[0244] (Tube Formability)

[0245] use The extruder (manufactured by Tanabe Plastic Machinery) extrudes the granules to form a tube with an outer diameter of 10.0 mm and a wall thickness of 1.0 mm. The extrusion molding conditions are as follows.

[0246] a) Die head inner diameter: 25mm

[0247] b) Outer diameter of the spindle: 13mm

[0248] c) Inner diameter of the shaping mold: 10.5mm

[0249] d) Traction speed: 0.4 m / min

[0250] e) Outer diameter: 10.0mm

[0251] f) Wall thickness: 1.0mm

[0252] g) Extrusion conditions:

[0253] • Single-screw extrusion molding machine with a barrel shaft diameter of 30mm and an L / D ratio of 22

[0254] Extruder set temperatures: Barrel section C-1 (350℃), Barrel section C-2 (370℃), Barrel section C-3 (380℃), Head section H-1 (390℃), Die section D-1 (390℃), Die section D-2 (390℃)

[0255] The obtained tubes are observed and evaluated according to the following criteria. The appearance of the tubes is confirmed visually.

[0256] ○: Good appearance

[0257] ×: The cross-section is not circular, and flatness or uneven thickness is observed, resulting in a poor appearance.

[0258] (Dielectric loss tangent)

[0259] The granules were melt-molded to produce cylindrical test pieces with a diameter of 2 mm. These test pieces were then placed on a 6 GHz cavity resonator manufactured by Kanto Electronics Application Development Co., Ltd., and measurements were taken using a network analyzer manufactured by Agilent Technologies. The measurement results were analyzed using the analysis software "CPMA" manufactured by Kanto Electronics Application Development Co., Ltd. on a personal computer connected to the network analyzer, thereby determining the dielectric loss tangent (tanδ) at 20°C and 6 GHz.

[0260]

Claims

1. A copolymer comprising tetrafluoroethylene units and perfluoro(propyl vinyl ether) units, The content of perfluoro(propyl vinyl ether) units is 3.9% to 5.5% by mass relative to all monomer units. The melt flow rate at 372℃ is 2.8 g / 10 min to 3.9 g / 10 min. The number of functional groups -CF=CF2, -CF2H, -COF, -COOH, -COOCH3, -CONH2, and -CH2OH relative to 10 6 The main chain has fewer than 20 carbon atoms.

2. An extruded article comprising the copolymer of claim 1.

3. A blow-molded article comprising the copolymer of claim 1.

4. A transfer molded article comprising the copolymer of claim 1.

5. A coated wire having a coating layer comprising the copolymer of claim 1.

6. A molded article comprising the copolymer of claim 1, wherein, The molded body is a piping component, wire sheath, pipe, membrane, or compressed component.

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