CN116897171A

CN116897171A - Copolymer, molded body, injection molded body, and coated electric wire

Info

Publication number: CN116897171A
Application number: CN202280016111.4A
Authority: CN
Inventors: 井坂忠晴; 善家佑美; 山本有香里; 津田早登; 山口安行
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2021-02-26
Filing date: 2022-01-31
Publication date: 2023-10-17

Abstract

The present invention provides a copolymer comprising tetrafluoroethylene units and perfluoro (propyl vinyl ether) units, wherein the content of the perfluoro (propyl vinyl ether) units is 4.4 to 6.0% by mass relative to the total monomer units, the melt flow rate at 372 ℃ is 7.5 to 11.0g/10 min, and the number of functional groups is per 10 ⁶ The number of carbon atoms of the main chain is 40 or less.

Description

Copolymer, molded body, injection molded body, and coated electric wire

Technical Field

The present invention relates to a copolymer, a molded body, an injection molded body, and a coated electric wire.

Background

Patent document 1 describes a molding material for ozone-resistant articles, which is composed of a copolymer (a) having a melt flow rate of 0.1g/10 min to 50g/10 min, and is characterized in that the copolymer (a) is a copolymer composed of tetrafluoroethylene and perfluorovinyl ether, contains 3.5 mass% or more of perfluorovinyl ether units, has a melting point of 295 ℃ or more, and has unstable terminal groups per 1×10 of the copolymer (a) ⁶ The number of carbon atoms is 50 or less.

Prior art literature

Patent literature

Patent document 1: international publication No. 2003/048214

Disclosure of Invention

Problems to be solved by the invention

The purpose of the present invention is to provide a copolymer which can be molded by an injection molding method, can easily give an injection molded article having a relatively large projected area and being beautiful, is less likely to corrode a mold used for molding, can form a very thick coating layer with a uniform thickness on a core wire having a very large diameter by an extrusion molding method, and can give a molded article having a low haze value, a mechanical strength at 100 ℃, an abrasion resistance at 150 ℃, an oxygen low permeability, a low reagent permeability, an extremely long-term ozone resistance, a creep resistance, excellent rigidity and non-adhesion at high temperature, and is less likely to dissolve out fluorine ions into a reagent such as an electrolyte.

Means for solving the problems

According to the present invention, there is provided a copolymer comprising tetrafluoroethylene units and perfluoro (propyl vinyl ether) units, perfluoro (propyl vinyl ether) unitsThe content of (C) is 4.4 to 6.0 mass% relative to the total monomer units, the melt flow rate at 372 ℃ is 7.5 to 11.0g/10 min, and the number of functional groups is relative to every 10 ⁶ The number of carbon atoms of the main chain is 40 or less.

Further, according to the present invention, there is provided an injection molded article comprising the copolymer.

Further, according to the present invention, there is provided a coated wire comprising a coating layer containing the copolymer.

Further, according to the present invention, there is provided a molded article comprising the copolymer, wherein the molded article is a flowmeter case, a film, a bottle, a wire coating or a tube.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide a copolymer which can be molded by injection molding, can easily give an injection molded article having a relatively large projected area and being beautiful, is less likely to corrode a mold used for molding, can form a very thick coating layer with a uniform thickness on a core wire having a very large diameter by extrusion molding, and can give a molded article having a low haze value, a mechanical strength at 100 ℃, a wear resistance at 150 ℃, a low oxygen permeability, a low reagent permeability, an extremely long-term ozone resistance, a creep resistance, excellent rigidity and non-adhesion at high temperature, and is less likely to cause elution of fluorine ions into a reagent such as an electrolyte.

Detailed Description

Hereinafter, specific embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

The copolymers of the present invention contain Tetrafluoroethylene (TFE) units and perfluoro (propyl vinyl ether) (PPVE) units.

A copolymer (PFA) containing TFE units and PPVE units is used as a piping member for transporting a reagent, and a flow meter member for measuring a flow rate of the reagent. In addition, from the viewpoint of easy confirmation of the reagent existing in the piping member and the flowmeter member, it is required that even when molding is performed by injection molding using a mold having a side gate, a beautiful molded article with suppressed surface roughness and flow mark generation is obtained and the haze value is small as a material for forming these. Further, since piping members and flowmeter members are used for, for example, transportation and flow measurement of a reagent at about 100 ℃, materials for forming these members are required to be capable of giving molded articles excellent in abrasion resistance at high temperatures, rigidity at high temperatures, oxygen low permeability, reagent low permeability, and mechanical properties at 100 ℃. Further, since the piping member and the flowmeter member repeatedly receive stress in response to the start of the flow of the reagent, the stop of the flow, and the change of the flow rate, a material capable of obtaining a molded article excellent in creep resistance is required as a material for forming these.

Patent document 1 describes that a molding material for an ozone resistant article having the above-described characteristics is a molding material excellent in ozone resistance in a state where chemical resistance, heat resistance, and mechanical properties of a fluororesin are maintained. In recent years, there has been a demand for a molding material having improved properties as compared with the molding material for ozone-resistant articles described in patent document 1, and in particular, a material which can provide a beautiful molded article having a roughened surface and suppressed flow mark generation and a molded article having improved oxygen low permeability and reagent low permeability even when molded by an injection molding method using a mold having a side gate is demanded. On the other hand, if it is intended to improve injection moldability or to improve oxygen low permeability and reagent low permeability, there is a problem that mechanical properties at 100 ℃ are poor or abrasion resistance at high temperature and ozone resistance over a long period of time are poor.

The discovery is as follows: by properly adjusting the content of PPVE unit, melt Flow Rate (MFR) and the number of functional groups of the copolymer containing TFE unit and PPVE unit, moldability of the copolymer is remarkably improved, and even in the case of molding by injection molding using a mold having a side gate, a beautiful molded article can be obtained while the mold for molding is not easily corroded. It was also found that: by using such a copolymer, a molded article having a small haze value, a mechanical strength at 100 ℃, abrasion resistance at 150 ℃, oxygen low permeability, reagent low permeability, extremely long-term ozone resistance, creep resistance, excellent rigidity and non-adhesion at high temperature, and being less likely to cause elution of fluorine ions into a reagent such as an electrolyte can be obtained.

Further, by molding the copolymer of the present invention by extrusion molding, a very thick coating layer can be formed with a uniform thickness on a very large diameter core wire. Thus, the copolymer of the present invention can be used not only as a material for piping members and flowmeter members, but also for a wide range of applications such as wire coating.

The copolymer of the present invention is a melt-processible fluororesin. Melt processability means that a polymer can be melted and processed using existing processing equipment such as an extruder and an injection molding machine.

The content of PPVE unit in the copolymer is 4.4-6.0% by mass relative to the total monomer units. The content of PPVE unit in the copolymer is preferably 4.5% by mass or more, more preferably 4.6% by mass or more, further preferably 4.7% by mass or more, still more preferably 4.8% by mass or more, particularly preferably 4.9% by mass or more, most preferably 5.0% by mass or more, preferably 5.9% by mass or less, more preferably 5.8% by mass or less, further preferably 5.7% by mass or less, and particularly preferably 5.6% by mass or less. By setting the PPVE unit content of the copolymer in the above range, a molded article having a small haze value, a mechanical strength at 100 ℃, an abrasion resistance at 150 ℃, a low permeability to oxygen, a low permeability to a reagent, an extremely long-term ozone resistance, a creep resistance, an excellent rigidity and non-adhesiveness at high temperature, and being less likely to cause elution of fluorine ions into a reagent such as an electrolyte can be obtained. If the content of PPVE unit in the copolymer is too small, a molded article having a small haze value, abrasion resistance at 150 ℃ and excellent ozone resistance over a very long period of time and mechanical strength at 100 ℃ cannot be obtained. If the PPVE unit content of the copolymer is too large, a molded article excellent in oxygen low permeability, reagent low permeability, rigidity at high temperature and creep resistance cannot be obtained.

The TFE unit content of the copolymer is preferably 94.0 to 95.6 mass%, more preferably 94.1 mass% or more, still more preferably 94.2 mass% or more, still more preferably 94.3 mass% or more, particularly preferably 94.4 mass% or more, still more preferably 95.5 mass% or less, still more preferably 95.4 mass% or less, still more preferably 95.3 mass% or less, particularly preferably 95.2 mass% or less, particularly preferably 95.1 mass% or less, and most preferably 95.0 mass% or less, based on the total monomer units. When the TFE unit content of the copolymer is in the above range, a molded article having a small haze value, a mechanical strength at 100 ℃, a low oxygen permeability, a low reagent permeability, a creep resistance, and excellent rigidity and non-tackiness at high temperatures, and being less likely to cause elution of fluorine ions into a reagent such as an electrolyte solution, can be obtained. If the TFE unit content of the copolymer is too large, there is a possibility that a molded article having a small haze value and excellent abrasion resistance at 150 ℃ and mechanical strength at 100 ℃ cannot be obtained. If the TFE unit content of the copolymer is too small, there is a possibility that a molded article excellent in oxygen low permeability, reagent low permeability, rigidity at high temperature and creep resistance cannot be obtained.

In the present invention, the content of each monomer unit in the copolymer is determined by ¹⁹ F-NMR measurement.

The copolymer may also contain monomer units derived from monomers copolymerizable with TFE and FAVE. In this case, the content of the monomer unit copolymerizable with TFE and PPVE is preferably 0 to 1.6 mass%, more preferably 0.05 to 1.4 mass%, and even more preferably 0.1 to 1.0 mass% relative to the total monomer units of the copolymer.

Examples of monomers copolymerizable with TFE and PPVE include Hexafluoropropylene (HFP) and CZ ¹ Z ² ＝CZ ³ (CF ₂ ) _n Z ⁴ (wherein Z is ¹ 、Z ² And Z ³ Identical or different, H or F, Z ⁴ H, F or Cl, n represents an integer of 2 to 10), and CF) ₂ ＝CF-ORf ¹ (wherein Rf ¹ Perfluoro (alkyl vinyl ether) [ PAVE ] represented by perfluoroalkyl group having 1 to 8 carbon atoms](except PPVE), and CF ₂ ＝CF-OCH ₂ -Rf ¹ (wherein Rf ¹ A perfluoroalkyl group having 1 to 5 carbon atoms. ) Alkyl perfluorovinyl ether derivatives shown and the like. Among them, HFP is preferable.

The copolymer is preferably at least one selected from the group consisting of a copolymer composed of only TFE units and PPVE units, and a TFE/HFP/PPVE copolymer, and more preferably a copolymer composed of only TFE units and PPVE units.

The Melt Flow Rate (MFR) of the copolymer is 7.5g/10 min to 11.0g/10 min. The MFR of the copolymer is preferably 8.0g/10 min or more, more preferably 8.5g/10 min or more, still more preferably 9.0g/10 min or more, preferably 10.9g/10 min or less, still more preferably 10.0g/10 min or less, still more preferably 9.5g/10 min or less, and particularly preferably 9.0g/10 min or less. If the MFR of the copolymer is too low, it may be difficult to obtain a beautiful injection molded article by injection molding, or the obtained molded article may be poor in rigidity at high temperature, oxygen low permeability and reagent low permeability. If the MFR of the copolymer is too high, it is difficult to form a very thick coating layer with a uniform thickness on a core wire having a very large diameter by extrusion molding, and there is a possibility that the abrasion resistance at 150 ℃ and ozone resistance for a very long period of time, and the mechanical strength and creep resistance at 100 ℃ of the obtained molded article may be deteriorated.

The copolymer of the present invention may be molded by injection molding or by wire coating extrusion molding, since the content of PPVE unit, melt Flow Rate (MFR) and the number of functional groups of the copolymer containing TFE unit and PPVE unit are appropriately adjusted. In the injection molding method, a copolymer that flows sufficiently by heating is suitable, but if an excessively high-temperature copolymer is used to form a coating layer of an electric wire having a large coating thickness, the variation in outer diameter may become large. The copolymer of the present invention can give an injection-molded article having a beautiful appearance even when molded by injection molding, and can give a coated wire having a small variation in outer diameter even when molded by wire coating extrusion molding.

In the present invention, MFR is a value obtained as a mass (g/10 min) of a polymer flowing out from a nozzle having an inner diameter of 2.1mm and a length of 8mm at 372℃under a 5kg load every 10 minutes using a melt index meter according to ASTM D1238.

The MFR can be adjusted by adjusting the kind and amount of a polymerization initiator used in polymerizing the monomers, the kind and amount of a chain transfer agent, and the like.

In the present invention, every 10 of the copolymer ⁶ The number of functional groups having the number of main chain carbon atoms is 40 or less. Every 10 of the copolymer ⁶ The number of functional groups having carbon atoms in the main chain is preferably 30 or less, more preferably 20 or less, still more preferably 15 or less, particularly preferably 10 or less, and most preferably less than 6. By setting the number of functional groups of the copolymer within the above range, the mold is less likely to corrode during molding using the mold. Further, a molded article having excellent ozone resistance, non-tackiness, and low permeability to a reagent such as an electrolyte solution and being less likely to cause elution of fluorine ions into the reagent such as the electrolyte solution can be obtained. In particular, by properly adjusting the content of PPVE unit, melt Flow Rate (MFR) and the number of functional groups of the copolymer containing TFE unit and PPVE unit, a molded article exhibiting excellent low permeability to various reagents such as dimethyl carbonate and methyl ethyl ketone can be obtained.

The identification of the kind of the functional group and the measurement of the number of functional groups may be performed by infrared spectroscopic analysis.

Specifically, the number of functional groups was measured by the following method. First, the copolymer was cold-molded to prepare a film having a thickness of 0.25mm to 0.3 mm. The film was analyzed by fourier transform infrared spectroscopy to obtain the infrared absorption spectrum of the above copolymer, and to obtain a differential spectrum from the fully fluorinated background spectrum without functional groups. The specific absorption peak of the specific functional group in the copolymer was calculated for every 1X 10 based on the following formula (A) ⁶ Number of functional groups N of carbon atoms.

N＝I×K/t(A)

I: absorbance of light

K: correction coefficient

t: film thickness (mm)

For reference, the absorption frequency, molar absorptivity, and correction factor are shown in table 1 for some functional groups. The molar absorptivity was determined from FT-IR measurement data of the low molecular weight model compound.

TABLE 1

-CH ₂ CF ₂ H、-CH ₂ COF、-CH ₂ COOH、-CH ₂ COOCH ₃ 、-CH ₂ CONH ₂ The absorption frequency ratios of (C) are shown in the tables respectively for-CF ₂ H. -COF, free-COOH and bonded-COOH, -COOCH ₃ 、-CONH ₂ Is tens of kesse (cm) ^-1 )。

For example, the functional group number of-COF means the number of functional groups derived from-CF ₂ Absorption frequency of COF 1883cm ^-1 The number of functional groups obtained from the absorption peak at the site and the number of functional groups obtained from the absorption peak derived from-CH ₂ Absorption frequency of COF 1840cm ^-1 The total number of functional groups obtained from the absorption peak at the position.

The functional groups are functional groups present at the main chain end or side chain end of the copolymer and functional groups present in the main chain or side chain. The number of functional groups may be-cf=cf ₂ 、-CF ₂ H、-COF、-COOH、-COOCH ₃ 、-CONH ₂ and-CH ₂ Total number of OH.

The functional group is introduced into the copolymer, for example, by a chain transfer agent or a polymerization initiator used in producing the copolymer. For example, using alcohols as chain transfer agents, or using compounds having-CH ₂ In the case of peroxides of OH structure as polymerization initiators, -CH ₂ OH is introduced into the backbone end of the copolymer. In addition, the functional group is introduced into the terminal of the side chain of the copolymer by polymerizing a monomer having the functional group.

By subjecting the copolymer having such a functional group to fluorination treatment, a copolymer having the number of functional groups in the above range can be obtained. That is, the copolymer of the present invention is preferably a fluorinated copolymer. The copolymers of the invention also preferably have-CF ₃ End groups.

The melting point of the copolymer is preferably 295℃to 315℃and more preferably 298℃or higher, still more preferably 300℃or higher, particularly preferably 301℃or higher, most preferably 302℃or higher, and still more preferably 308℃or lower. When the melting point is within the above range, a copolymer which provides a molded article having more excellent mechanical properties particularly at high temperature (for example, 100 ℃) can be obtained.

In the present invention, the melting point can be measured using a differential scanning calorimeter [ DSC ].

The haze value of the copolymer of the present invention is preferably 11.5% or less, more preferably 11% or less, further preferably 10.5% or less, particularly preferably 10% or less. When the haze value is within the above range, it is easy to confirm the flow rate and the remaining amount of the content by visual observation, a camera or the like in the inside of the molded article when the molded article such as a pipe, a joint, a flowmeter case or the like is obtained. In the present invention, the haze value can be measured in accordance with JIS K7136.

The copolymer of the present invention preferably has a tensile strength at 100℃of 19.5MPa or more, more preferably 20MPa or more. When the tensile strength at 100 ℃ is in the above range, the thermal deformation of the molded article can be further suppressed when the molded article obtained is used as a member in contact with a high-temperature reagent, and the life of the member can be further increased and the cost due to the reduction in the replacement frequency can be further reduced. In addition, even when pressure is applied from the high-temperature fluid, deformation and damage of the molded body can be prevented, and therefore, a large flow rate of the high-temperature fluid can be circulated. In the present invention, the tensile strength at 100℃can be measured in accordance with ASTM D638. The tensile strength can be increased by adjusting the PPVE unit content, melt Flow Rate (MFR) and the number of functional groups of the copolymer.

The oxygen permeability coefficient of the copolymer is preferably 920cm ³ ·mm/(m ² 24 h.atm) or less. The copolymer of the present invention has excellent oxygen low permeability because the content of PPVE unit, melt Flow Rate (MFR) and the number of functional groups of the copolymer containing TFE unit and PPVE unit are appropriately adjusted. Therefore, oxygen does not readily permeate the molded article formed of the copolymer, and therefore, for example, a piping member or a flowmeter member obtained by using the copolymer of the present invention can be suitably used for the purpose of avoiding oxidationIs used for conveying the reagent.

In the present invention, the oxygen permeability coefficient can be measured under the conditions of a test temperature of 70℃and a test humidity of 0% RH. The oxygen permeability coefficient can be specifically measured by the method described in examples.

The electrolyte permeability of the copolymer is preferably 7.5 g.cm/m ² The following is given. The copolymer of the present invention has excellent electrolyte low permeability because the content of PPVE unit, melt Flow Rate (MFR) and the number of functional groups of the copolymer containing TFE unit and PPVE unit are appropriately adjusted. That is, by using the copolymer of the present invention, a molded article which is difficult to permeate a reagent such as an electrolyte can be obtained.

In the present invention, the electrolyte permeability can be measured at a temperature of 60℃for 30 days. Specific measurement of the electrolyte permeability can be performed by the method described in examples.

The copolymer preferably has a Methyl Ethyl Ketone (MEK) permeability of 72.0mg cm/m ² Day or less. The copolymer of the present invention has excellent MEK low permeability because the content of PPVE unit, melt Flow Rate (MFR) and the number of functional groups of the copolymer containing TFE unit and PPVE unit are appropriately adjusted. That is, by using the copolymer of the present invention, a molded article which is less likely to be permeable to a reagent such as MEK can be obtained.

In the present invention, MEK transmittance can be measured at a temperature of 60 ℃ for 60 days. Specific measurement of MEK transmission can be performed by the methods described in examples.

The amount of the eluted fluoride ion detected in the electrolyte impregnation test of the copolymer of the present invention is preferably 1.0ppm or less, more preferably 0.8ppm or less, and still more preferably 0.7ppm or less on a mass basis. By adjusting the amount of the eluted fluoride ions within the above range, the generation of gas such as HF in the nonaqueous electrolyte battery can be further suppressed, and deterioration in battery performance and short lifetime of the nonaqueous electrolyte battery can be further suppressed.

In the present invention, the electrolyte impregnation test can be performed as follows: a test piece having a weight equivalent to 10 molded articles (15 mm. Times.15 mm. Times.0.2 mm) was prepared using the copolymer, and a glass sample bottle containing the test piece and 2g of dimethyl carbonate (DMC) was placed in a constant temperature bath at 80℃for 144 hours.

The copolymer of the present invention can be produced by a polymerization method such as suspension polymerization, solution polymerization, emulsion polymerization, or bulk polymerization. As the polymerization method, emulsion polymerization or suspension polymerization is preferable. In these polymerizations, the conditions such as temperature and pressure, polymerization initiator, and other additives may be appropriately set according to the composition and amount of the copolymer.

As the polymerization initiator, an oil-soluble radical polymerization initiator or a water-soluble radical polymerization initiator can be used.

The oil-soluble radical polymerization initiator may be a known oil-soluble peroxide, and the following are exemplified as typical examples:

dialkyl peroxycarbonates such as di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, and di-2-ethoxyethyl peroxydicarbonate;

peroxyesters such as t-butyl peroxyisobutyrate and t-butyl peroxypivalate;

dialkyl peroxides such as di-t-butyl peroxide;

di [ fluoro (or fluoro chloro) acyl ] peroxides; etc.

As bis [ fluoro (or fluoro chloro) acyl groups]The peroxides include [ (RfCOO) & lt- & gt ]] ₂ (Rf is perfluoroalkyl, omega-hydroperfluoroalkyl or fluorochloroalkyl).

Examples of the di [ fluoro (or fluorochloroacyl ] peroxides include di (ω -hydro-dodecafluoroheptanoyl) peroxide, di (ω -hydro-hexadecanoyl) peroxide, di (perfluoropropionyl) peroxide, di (perfluorobutanoyl) peroxide, di (perfluoropentanoyl) peroxide, di (perfluorohexanoyl) peroxide, di (perfluoroheptanoyl) peroxide, di (perfluorooctanoyl) peroxide, di (perfluorononanoyl) peroxide, di (ω -chloro-hexafluorobutanoyl) peroxide, di (ω -chloro-dodecafluoroheptanoyl) peroxide, di (ω -chloro-dodecafluorooctanoyl) peroxide, ω -hydro-dodecafluoroheptanoyl-peroxide, ω -chloro-hexafluorobutanoyl-peroxide, ω -hydrododecafluoroheptanoyl-perfluorobutanoyl-peroxide, di (perfluoroheptanoyl) peroxide, di (dichloro-heptanoyl) peroxide, di (dichloro-dodecanoyl) peroxide, and di (dichloro-dodecanoyl) dodecanoyl peroxide.

The water-soluble radical polymerization initiator may be a known water-soluble peroxide, and examples thereof include ammonium salts such as persulfuric acid, perboric acid, perchloric acid, perphosphoric acid, and percarbonic acid, potassium salts, sodium salts, disuccinic acid peroxide, and organic peroxides such as dipentaerythritol peroxide, t-butyl peroxymaleate, and t-butyl hydroperoxide. The reducing agent such as sulfite may be used in combination with the peroxide in an amount of 0.1 to 20 times the amount of the peroxide.

In the polymerization, a surfactant, a chain transfer agent and a solvent may be used, and conventionally known ones may be used, respectively.

As the surfactant, a known surfactant can be used, and for example, a nonionic surfactant, an anionic surfactant, a cationic surfactant, and the like can be used. Among them, the fluorinated anionic surfactant is preferable, and the fluorinated anionic surfactant having 4 to 20 carbon atoms, which may be linear or branched, and which may or may not contain ether-bonded oxygen (i.e., may have an oxygen atom interposed between carbon atoms), is more preferable. The amount of the surfactant to be added (relative to the polymerization water) is preferably 50ppm to 5000ppm.

Examples of the chain transfer agent include: hydrocarbons such as ethane, isopentane, n-hexane, and cyclohexane; aromatic compounds such as toluene and xylene; ketones such as acetone; acetate esters such as ethyl acetate and butyl acetate; alcohols such as methanol and ethanol; mercaptans such as methyl mercaptan; halogenated hydrocarbons such as carbon tetrachloride, chloroform, methylene chloride and methyl chloride; etc. The amount of the chain transfer agent to be added may vary depending on the amount of the chain transfer constant of the compound to be used, and is usually in the range of 0.01 to 20% by mass relative to the polymerization solvent.

Examples of the solvent include water, a mixed solvent of water and alcohol, and the like.

In the suspension polymerization, a fluorine-based solvent may be used in addition to water. As the fluorine-based solvent, CH may be mentioned ₃ CClF ₂ 、CH ₃ CCl ₂ F、CF ₃ CF ₂ CCl ₂ H、CF ₂ ClCF ₂ Hydrochlorofluoroalkanes such as CFHCl; CF (compact flash) ₂ ClCFClCF ₂ CF ₃ 、CF ₃ CFClCFClCF ₃ Isophlorofluoroalkanes; CF (compact flash) ₃ CFHCFHCF ₂ CF ₂ CF ₃ 、CF ₂ HCF ₂ CF ₂ CF ₂ CF ₂ H、CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ CF ₂ Hydrofluoroalkanes such as H; CH (CH) ₃ OC ₂ F ₅ 、CH ₃ OC ₃ F ₅ CF ₃ CF ₂ CH ₂ OCHF ₂ 、CF ₃ CHFCF ₂ OCH ₃ 、CHF ₂ CF ₂ OCH ₂ F、(CF ₃ ) ₂ CHCF ₂ OCH ₃ 、CF ₃ CF ₂ CH ₂ OCH ₂ CHF ₂ 、CF ₃ CHFCF ₂ OCH ₂ CF ₃ Isohydrofluoroethers; perfluorocyclobutane, CF ₃ CF ₂ CF ₂ CF ₃ 、CF ₃ CF ₂ CF ₂ CF ₂ CF ₃ 、CF ₃ CF ₂ CF ₂ CF ₂ CF ₂ CF ₃ Among them, perfluoroalkanes are preferable. The amount of the fluorine-based solvent to be used is preferably 10 to 100% by mass based on the aqueous medium in view of suspension property and economy.

The polymerization temperature is not particularly limited, and may be 0 to 100 ℃. The polymerization pressure is appropriately determined depending on the kind and amount of the solvent used, the vapor pressure, the polymerization temperature, and other polymerization conditions, and may be generally 0 to 9.8MPaG.

When an aqueous dispersion containing a copolymer is obtained by polymerization, the copolymer contained in the aqueous dispersion can be precipitated, washed, and dried to recover the copolymer. In addition, in the case where the copolymer is obtained as a slurry by polymerization, the copolymer can be recovered by taking out the slurry from the reaction vessel, washing it, and drying it. The copolymer can be recovered in the form of a powder by drying.

The copolymer obtained by polymerization may be molded into pellets. The molding method for molding the pellets is not particularly limited, and conventionally known methods can be used. For example, a method of melt-extruding a copolymer using a single screw extruder, a twin screw extruder, or a tandem extruder, cutting the copolymer into a predetermined length, and molding the copolymer into pellets, and the like can be mentioned. The extrusion temperature at the time of melt extrusion is required to be changed depending on the melt viscosity of the copolymer and the production method, and is preferably from +20℃to +140℃of the melting point of the copolymer. The method of cutting the copolymer is not particularly limited, and conventionally known methods such as a wire cutting method, a thermal cutting method, an underwater cutting method, and a sheet cutting method can be employed. The volatile components in the pellets may also be removed by heating the resulting pellets (degassing treatment). The obtained pellets may be treated by contacting them with warm water at 30 to 200 ℃, steam at 100 to 200 ℃ or hot air at 40 to 200 ℃.

The copolymer obtained by polymerization may also be subjected to a fluorination treatment. The fluorination treatment may be performed by contacting the copolymer that has not been subjected to the fluorination treatment with a fluorine-containing compound. By fluorination treatment, the-COOH, -COOCH-of the copolymer can be obtained ₃ 、-CH ₂ OH、-COF、-CF＝CF ₂ 、-CONH ₂ Isothermally labile functional groups and relatively thermally stable-CF ₂ Conversion of functional groups such as H to extremely thermally stable-CF ₃ . As a result, the-COOH, -COOCH-of the copolymer can be used ₃ 、-CH ₂ OH、-COF、-CF＝CF ₂ 、-CONH ₂ and-CF ₂ The total number of H (the number of functional groups) is easily adjusted to be within the above-mentioned range.

The fluorine-containing compound is not particularly limited, and examples thereof include a fluorine radical source that generates a fluorine radical under the fluorination treatment conditions. Acting asAs the fluorine radical source, F may be mentioned ₂ Gas, coF ₃ 、AgF ₂ 、UF ₆ 、OF ₂ 、N ₂ F ₂ 、CF ₃ OF, fluorinated halogens (e.g. IF ₅ 、ClF ₃ ) Etc.

F ₂ The fluorine radical source such as gas may be used at a concentration of 100%, but from the viewpoint of safety, it is preferably used by mixing with an inactive gas and diluting to 5 to 50% by mass, more preferably 15 to 30% by mass. The inert gas may be nitrogen, helium, argon, or the like, and nitrogen is preferable from the viewpoint of economy.

The conditions of the fluorination treatment are not particularly limited, and the copolymer in a molten state may be brought into contact with the fluorine-containing compound, but may be usually conducted at a temperature of 20 to 240℃and more preferably 100 to 220℃below the melting point of the copolymer. The fluorination treatment is generally carried out for 1 to 30 hours, preferably 5 to 25 hours. The fluorination treatment preferably involves reacting the copolymer which has not been subjected to the fluorination treatment with fluorine gas (F ₂ Gas) contact.

The copolymer of the present invention may be mixed with other components as needed to obtain a composition. Examples of the 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, perfumes, oils, softeners, dehydrofluorination agents, and the like.

Examples of the filler include silica, kaolin, clay, organized clay, talc, mica, alumina, calcium carbonate, calcium terephthalate, titanium oxide, calcium phosphate, calcium fluoride, lithium fluoride, crosslinked polystyrene, potassium titanate, carbon, boron nitride, carbon nanotubes, and glass fibers. Examples of the conductive agent include carbon black. Examples of the plasticizer include dioctyl phthalate and pentaerythritol. Examples of the processing aid include carnauba wax, sulfone compound, low molecular weight polyethylene, and fluorine-based aid. Examples of the dehydrofluorination agent include organic onium and amidines.

As the other components, other polymers than the above copolymers may be used. Examples of the other polymer include a fluororesin other than the above copolymer, a fluororubber, a nonfluorinated polymer, and the like.

The method for producing the composition includes: a method of dry-mixing the copolymer with other components; a method in which the copolymer and other components are mixed in advance by a mixer, and then melt-kneaded by a kneader, a melt extruder, or the like; etc.

The copolymer or the composition of the present invention can be used as a processing aid, a molding material, or the like, and is preferably used as a molding material. Aqueous dispersions, solutions, suspensions, and copolymer/solvent systems of the copolymers of the present invention may also be utilized, which may be applied as coatings or used for encapsulation, impregnation, film casting. However, the copolymer of the present invention is preferably used as the molding material because it has the above-mentioned characteristics.

The copolymer of the present invention or the above composition may be molded to obtain a molded article.

The method for molding the copolymer or the composition is not particularly limited, and examples thereof include injection molding, extrusion molding, compression molding, blow molding, transfer molding, rotational molding, and roll lining molding. Among the molding methods, extrusion molding, compression molding, injection molding or transfer molding is preferable, and injection molding is more preferable because a molded article can be produced with high productivity. That is, the molded article is preferably an extrusion molded article, a compression molded article, an injection molded article or a transfer molded article, and more preferably an injection molded article, an extrusion molded article or a transfer molded article, and even more preferably an injection molded article, since it can be produced at high productivity. By molding the copolymer of the present invention by injection molding, an injection molded article having a beautiful appearance can be obtained without corroding a mold for molding.

Examples of molded articles containing the copolymer of the present invention include nuts, bolts, joints, films, bottles, gaskets, wire coatings, pipes, hoses, pipes, valves, sheets, seals, gaskets, tanks, rolls, containers, taps, connectors, filter housings, filter covers, flow meters, pumps, wafer carriers, wafer cassettes, and the like.

The copolymer, the composition or the molded article of the present invention can be used for the following purposes, for example.

A film for packaging food, a lining material for a fluid transfer line used in a food manufacturing process, a gasket, a sealing material, a fluid transfer member for a food manufacturing apparatus such as a sheet;

reagent delivery members such as plugs for chemicals, packaging films, liners for fluid delivery lines used in chemical manufacturing processes, gaskets, seals, sheets, etc.;

inner lining members of reagent tanks and piping of chemical equipment and semiconductor factories;

fuel delivery members such as hoses and sealing materials used in AT devices of automobiles such as O (square) rings/tubes/gaskets, valve core materials, hoses and sealing materials used in fuel systems and peripheral devices of automobiles;

flange gaskets, shaft seals, stem seals, sealing materials, brake hoses for automobiles such as hoses, air conditioning hoses, radiator hoses, wire coating materials, and other automobile components used in engines and peripheral devices of automobiles;

A reagent transporting member for a semiconductor device, such as an O-ring, a tube, a gasket, a valve body material, a hose, a sealing material, a roller, a gasket, a diaphragm, and a joint of a semiconductor manufacturing apparatus;

coating and ink members such as coating rolls, hoses, tubes, ink containers for coating equipment;

pipes such as pipes for food and drink, hoses, belts, gaskets, joints, and other food and drink conveying members, food packaging materials, and glass cooking devices;

a waste liquid transporting member such as a tube or a hose for transporting waste liquid;

high-temperature liquid transmission members such as pipes and hoses for high-temperature liquid transmission;

a member for steam piping such as a pipe or a hose for steam piping;

a corrosion-resistant belt for piping such as a belt wound around piping such as a deck of a ship;

various coating materials such as a wire coating material, an optical fiber coating material, a transparent surface coating material provided on a light incidence side surface of a photovoltaic element of a solar cell, and a back surface agent;

sliding components such as diaphragms and various gaskets of the diaphragm pump;

weather resistant covers for agricultural films, various roofing materials, sidewalls, and the like;

glass-like coating materials such as interior materials and incombustible fire-resistant safety glass used in the construction field;

Lining materials such as laminated steel sheets used in the field of home appliances and the like.

Further examples of the fuel delivery member used in the fuel system of the automobile include a fuel hose, a filler hose, and an evaporator hose. The fuel delivery member can be used as a fuel delivery member for acid-resistant gasoline, alcohol-resistant fuel, and fuel to which a gasoline additive such as methyl t-butyl ether or amine-resistant additive is added.

The above-mentioned chemical stopper and packaging film have excellent chemical resistance to acids and the like. The reagent transporting member may be an anti-corrosive tape wound around a piping of a chemical apparatus.

Examples of the molded article include radiator chambers, reagent tanks, bellows, separators, rolls, gasoline tanks, waste liquid transport containers, high-temperature liquid transport containers, fishery and fish farming tanks, and the like of automobiles.

Further, examples of the molded article include a bumper, a door trim, an instrument panel, a food processing device, a cooking machine, water/oil resistant glass, a lighting-related instrument, an indication board and a housing for OA instruments, an electric lighting sign, a display screen, a liquid crystal display, a cellular phone, a printer chassis, electric and electronic parts, sundries, a dustbin, a bathtub, an entire bathroom, a ventilator, a lighting frame, and the like.

The molded article containing the copolymer of the present invention has a small haze value, a mechanical strength at 100 ℃, an abrasion resistance at 150 ℃, a low oxygen permeability, a low reagent permeability, an extremely long-term ozone resistance, a creep resistance, and excellent rigidity and non-adhesiveness at high temperatures, and is less likely to cause elution of fluorine ions into a reagent such as an electrolyte, and therefore can be suitably used for nuts, bolts, joints, gaskets, valves, taps, connectors, filter housings, filter housing frames, flow meters, pumps, and the like. Among them, the present invention can be suitably used as a piping member (in particular, a joint) used for transporting a reagent and a flowmeter case having a flow path for a reagent in a flowmeter. The piping member and the flowmeter case of the present invention have a low haze value, and are excellent in mechanical strength at 100 ℃, abrasion resistance at 150 ℃, low oxygen permeability, low reagent permeability, ozone resistance over a very long period of time, creep resistance, rigidity at high temperature, and non-tackiness. Therefore, the piping member and the flowmeter case of the present invention are excellent in visibility, and particularly in the flowmeter case, the float in the interior can be easily observed by visual observation, a camera, or the like, and the piping member and the flowmeter case can be suitably used for flow rate measurement of a reagent at about 100 ℃. Further, the piping member and the flowmeter case of the present invention can be easily manufactured by injection molding without corroding a mold for molding, and have a beautiful appearance.

The molded article containing the copolymer of the present invention can be easily produced by injection molding without corroding a mold, has excellent mechanical strength and non-tackiness at 100 ℃, and is less likely to cause elution of fluorine ions into a reagent such as an electrolyte, and therefore can be suitably used as a compressed member such as a gasket or a gasket. The compressed member of the present invention may be a gasket or a seal. The gasket or the gasket of the present invention can be manufactured at low cost by injection molding without corroding a mold, and is not easily damaged even if it is provided at a position where it is repeatedly opened and closed at a high frequency.

The size and shape of the compressed member of the present invention may be appropriately set according to the application, and are not particularly limited. The compressed member of the present invention may be annular in shape, for example. The compressed member of the present invention may have a circular shape, an elliptical shape, a quadrangular shape with rounded corners, or the like in a plan view, and may have a through hole in a central portion thereof.

The compressed member of the present invention is preferably used as a member for constituting a nonaqueous electrolyte battery. The compressed member of the present invention is particularly suitable as a member used in a state of being in contact with a nonaqueous electrolyte in a nonaqueous electrolyte battery because fluorine ions are not easily eluted into the electrolyte. That is, the compressed member of the present invention may have a liquid receiving surface of the nonaqueous electrolyte in the nonaqueous electrolyte battery.

The compressed member of the present invention is less likely to cause elution of fluorine ions into a nonaqueous electrolytic solution. Therefore, by using the compressed member of the present invention, an increase in the fluoride ion concentration in the nonaqueous electrolytic solution can be suppressed. As a result, by using the compressed member of the present invention, the generation of gas such as HF in the nonaqueous electrolyte battery can be suppressed, or the deterioration of the battery performance and the reduction of the lifetime of the nonaqueous electrolyte battery can be suppressed.

The compressed member of the present invention can further suppress the generation of gas such as HF in the nonaqueous electrolyte battery or can further suppress the deterioration of battery performance and the reduction of lifetime of the nonaqueous electrolyte battery, and therefore the amount of dissolved fluorine ions detected in the electrolyte impregnation test is preferably 1.0ppm or less, preferably 0.8ppm or less, more preferably 0.7ppm or less on a mass basis. The electrolyte impregnation test can be performed as follows: a test piece having a weight equivalent to 10 molded articles (15 mm. Times.15 mm. Times.0.2 mm) was produced using the compressed member, and a glass sample bottle containing the test piece and 2g of dimethyl carbonate (DMC) was placed in a constant temperature bath at 80℃for 144 hours.

The nonaqueous electrolyte battery is not particularly limited as long as it is a battery provided with a nonaqueous electrolyte, and examples thereof include a lithium ion secondary battery and a lithium ion capacitor. Further, as a member constituting the nonaqueous electrolyte battery, a sealing member, an insulating member, and the like can be given.

The nonaqueous electrolyte is not particularly limited, and propylene carbonate, ethylene carbonate, butylene carbonate, and gamma-butyl carbonate may be used1 or more of known solvents such as lactone, 1, 2-dimethoxyethane, 1, 2-diethoxyethane, dimethyl carbonate, diethyl carbonate, and methylethyl carbonate. The nonaqueous electrolyte battery may further include an electrolyte. The electrolyte is not particularly limited, and LiClO may be used ₄ 、LiAsF ₆ 、LiPF ₆ 、LiBF ₄ 、LiCl、LiBr、CH ₃ SO ₃ Li、CF ₃ SO ₃ Li, cesium carbonate, and the like.

The compressed member of the present invention can be preferably used as a sealing member such as a gasket or a packing, or an insulating member such as an insulating gasket or an insulating packing, for example. The sealing member is used to prevent leakage of liquid or gas or intrusion of liquid or gas from the outside. The insulating member is a member used for electrical insulation. The compressed member of the present invention may be a member used for both sealing and insulation purposes.

The compressed member of the present invention is excellent in mechanical strength and non-tackiness at 100 ℃ and is not likely to cause elution of fluorine ions into an electrolyte, and therefore can be suitably used as a sealing member for a nonaqueous electrolyte battery or an insulating member for a nonaqueous electrolyte battery. For example, when a battery such as a nonaqueous electrolyte secondary battery is charged, the temperature of the battery may temporarily reach 40 ℃ or higher. The compressed member of the present invention is used in a battery such as a nonaqueous electrolyte secondary battery by deforming at a high compression deformation rate even at a high temperature, and does not deteriorate high rebound resilience even when it is in contact with a nonaqueous electrolyte at a high temperature. Therefore, in the case where the compressed member of the present invention is used as a sealing member, it has excellent sealing properties and can maintain the sealing properties for a long period of time even at high temperatures. In addition, the compressed member of the present invention has excellent insulating properties because it contains the copolymer. Therefore, when the compressed member of the present invention is used as an insulating member, the compressed member is firmly adhered to 2 or more conductive members, and short-circuiting can be prevented for a long period of time.

By molding the copolymer of the present invention by extrusion molding, a very thick coating layer can be formed with a uniform thickness on a core wire having a very large diameter, and therefore the copolymer of the present invention can be suitably used as a material for forming an electric wire coating. Therefore, the coated wire having the coating layer containing the copolymer of the present invention has little variation in outer diameter and is excellent in electrical characteristics.

When a very thick coating layer is formed on a very large diameter core wire with a uniform thickness, it takes a long time until the coating layer in a molten state is solidified, and the weight of the coating layer is also large, so that when a conventional copolymer is used, the coating layer is deformed by its own weight before solidification, and there is a problem that it is difficult to form a coating layer with a uniform thickness. By using the copolymer of the present invention, a very thick coating layer can be formed with a uniform thickness.

The coated wire comprises a core wire and a coating layer provided around the core wire and containing the copolymer of the present invention. For example, an extrusion molded article obtained by melt-extruding the copolymer of the present invention on a core wire may be used as the coating layer. The coated electric wire is suitable for high-frequency transmission cables, flat cables, heat-resistant cables, and the like, among which is suitable for high-frequency transmission cables.

As the material of the core wire, for example, a metal conductor material such as copper or aluminum can be used. The core wire preferably has a diameter of 0.02mm to 3mm. The diameter of the core wire is more preferably 0.04mm or more, still more preferably 0.05mm or more, and particularly preferably 0.1mm or more. The diameter of the core wire is more preferably 2mm or less.

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

The thickness of the coating layer is preferably 0.1mm to 3.0mm. The thickness of the coating layer is also preferably 2.0mm or less.

As the high-frequency transmission cable, a coaxial cable may be mentioned. The coaxial cable generally has a structure in which an inner conductor, an insulating coating layer, an outer conductor layer, and a protective coating layer are laminated in this order from a core portion to an outer peripheral portion. The molded article containing the copolymer of the present invention can be suitably used as an insulating coating layer containing the copolymer. The thickness of each layer in the above-described structure is not particularly limited, and in general, the diameter of the inner conductor is about 0.1mm to 3mm, the thickness of the insulating coating layer is about 0.3mm to 3mm, the thickness of the outer conductor layer is about 0.5mm to 10mm, and the thickness of the protective coating layer is about 0.5mm to 2mm.

The coating may contain bubbles, which are preferably uniformly distributed in the coating.

The average cell diameter of the bubbles is not limited, and is, for example, preferably 60 μm or less, more preferably 45 μm or less, further preferably 35 μm or less, further preferably 30 μm or less, particularly preferably 25 μm or less, and particularly preferably 23 μm or less. The average cell diameter is preferably 0.1 μm or more, more preferably 1 μm or more. The average bubble diameter can be obtained by obtaining an electron microscope image of a wire cross section, calculating the diameter of each bubble by image processing, and averaging.

The foaming ratio of the coating layer may be 20% or more. More preferably 30% or more, still more preferably 33% or more, still more preferably 35% or more. The upper limit is not particularly limited, and is, for example, 80%. The upper limit of the foaming ratio may be 60%. The foaming ratio was obtained as ((specific gravity of wire coating material-specific gravity of coating layer)/specific gravity of wire coating material) ×100. The foaming ratio can be appropriately adjusted according to the application by, for example, adjusting the amount of gas inserted into an extruder to be described later, or by selecting the type of dissolved gas.

The coated wire may further include a different layer (outer layer) around the coating layer, and a different layer may be provided between the core wire and the coating layer. When the coating layer contains bubbles, the electric wire of the present invention may have a 2-layer structure (skin-foam) in which a non-foam layer is interposed between the core wire and the coating layer; a 2-layer structure (foam-skin) having a non-foam layer coated on the outer layer; further, the outer layer of the skin-foam was covered with a 3-layer structure (skin-foam-skin) of a non-foam layer. The non-expanded layer is not particularly limited, and may be a resin layer composed of a polyolefin resin such as TFE/HFP copolymer, TFE/PAVE copolymer, TFE/ethylene copolymer, vinylidene fluoride polymer, polyethylene [ PE ], or a resin such as polyvinyl chloride [ PVC ].

The coated wire can be produced, for example, by heating the copolymer using an extruder, extruding the copolymer onto the core wire in a molten state, and forming a coating layer.

In forming the coating layer, the gas may be introduced into the copolymer in a molten state by heating the copolymer, thereby forming the coating layer containing bubbles. As the gas, for example, a gas such as difluoromethane, nitrogen, carbon dioxide, or the like, or a mixture of the above gases can be used. The gas may be introduced into the heated copolymer as a pressurized gas or may be produced by mixing a chemical blowing agent into the copolymer. The gas is dissolved in the copolymer in a molten state.

In addition, the copolymer of the present invention can be suitably used as a material for a product for high-frequency signal transmission.

The product for transmitting a high-frequency signal is not particularly limited as long as it is a product for transmitting a high-frequency signal, and examples thereof include (1) a molded plate such as an insulating plate for a high-frequency circuit, an insulating material for a connecting member, and a printed wiring board, (2) a molded body such as a base or a radome for a high-frequency vacuum tube, and (3) a covered wire such as a coaxial cable or a LAN cable. The high-frequency signal transmission product can be suitably used for satellite communication equipment, mobile telephone base stations, and other equipment utilizing microwaves, particularly microwaves of 3GHz to 30 GHz.

In the above-mentioned high-frequency signal transmission product, the copolymer of the present invention is suitable for use as an insulator in view of low dielectric loss tangent.

The molded plate (1) is preferably a printed wiring board in terms of obtaining good electrical characteristics. The printed wiring board is not particularly limited, and examples thereof include printed wiring boards for electronic circuits of mobile phones, various computers, communication devices, and the like. As the molded article (2), a radome is preferable in terms of low dielectric loss.

The copolymer of the present invention can be molded by injection molding to obtain a beautiful sheet. Further, the molded article containing the copolymer of the present invention is excellent in mechanical strength and non-tackiness at 100 ℃. Therefore, the molded article containing the copolymer of the present invention can be suitably used as a film or sheet.

The films of the present invention are particularly excellent in non-adhesion. Therefore, even when the film of the present invention, the resin such as epoxy resin, toner, and the like are hot-pressed, the two are not adhered, and the resin, toner, and the like can be peeled from the film.

The film of the present invention is useful as a release film. The release film can be produced by molding the copolymer of the present invention by melt extrusion molding, calender molding, press molding, casting molding, or the like. From the viewpoint of obtaining a uniform film, a release film can be produced by melt extrusion molding.

The film of the present invention can be applied to the surface of a roll used in an OA apparatus. The copolymer of the present invention can be molded into a desired shape by extrusion molding, compression molding, press molding, etc., and formed into a sheet, film, tube shape, etc., for use as a surface material for OA equipment rolls, OA equipment belts, etc. In particular, thin-walled tubes and films can be produced by melt extrusion.

The molded article containing the copolymer of the present invention has a small haze value, a mechanical strength at 100 ℃, an abrasion resistance at 150 ℃, a low oxygen permeability, a low reagent permeability, an extremely long-term ozone resistance, a creep resistance, and excellent rigidity and non-adhesion at high temperatures, and is less likely to cause elution of fluorine ions into an electrolyte, and therefore can be suitably used as a bottle or a tube. The bottle or tube of the present invention can easily visually confirm the content, and is not easily damaged in use.

While the embodiments have been described above, it will be understood that various changes in form and details may be made therein without departing from the spirit and scope of the claims.

Examples

Next, embodiments of the present invention will be described with reference to examples, but the present invention is not limited to the examples.

The values of the examples were measured by the following methods.

(content of monomer units)

The content of each monomer unit was measured by an NMR analyzer (for example, AVANCE300 high temperature probe manufactured by Bruker Biospin Co.).

(melt flow Rate (MFR))

The mass (G/10 minutes) of the polymer flowing out from a nozzle having an inner diameter of 2.1mm and a length of 8mm per 10 minutes was determined by using a melt index analyzer G-01 (manufactured by Toyo Seisakusho-Sho Co., ltd.) at 372℃under a 5kg load in accordance with ASTM D1238.

(number of functional groups)

The pellets of the copolymer were cold-molded to prepare a film having a thickness of 0.25mm to 0.3 mm. By Fourier transform infrared Spectrum analysis device [ FT-IR (Spectrum One manufactured by Perkinelmer Co.)]The film was scanned 40 times and analyzed to obtain an infrared absorption spectrum and a differential spectrum from a fully fluorinated background spectrum without functional groups. The absorbance peak of the specific functional group shown by the differential spectrum was calculated for every 1X 10 in the sample according to the following formula (A) ⁶ Number of functional groups N of carbon atoms.

N＝I×K/t(A)

I: absorbance of light

K: correction coefficient

t: film thickness (mm)

For reference, regarding the functional groups in the present invention, the absorption frequency, molar absorptivity, and correction coefficient are shown in table 2. The molar absorptivity is determined from FT-IR measurement data of the low molecular weight model compound.

TABLE 2

(melting point)

The melting point was determined from the melting curve peak generated during the 2 nd heating process by performing the 1 st heating from 200℃to 350℃at a heating rate of 10℃per minute using a differential scanning calorimeter (trade name: X-DSC7000, manufactured by Hitachi High-Tech Science Co., ltd.), then cooling from 350℃to 200℃at a cooling rate of 10℃per minute, and performing the 2 nd heating from 200℃to 350℃again at a heating rate of 10℃per minute.

Example 1

After adding 26.6L of pure water to a 174L-volume autoclave and sufficiently performing nitrogen substitution, 30.4kg of perfluorocyclobutane, 1.40kg of perfluoro (propyl vinyl ether) (PPVE) and 0.31kg of methanol were added, the temperature in the system was kept at 35℃and the stirring speed was kept at 200rpm. Subsequently, tetrafluoroethylene (TFE) was introduced under pressure to 0.58MPa, and then 0.010kg of a 50% methanol solution of di-n-propyl peroxydicarbonate was introduced to start polymerization. Since the pressure in the system decreased as polymerization proceeded, TFE was continuously fed so that the pressure became constant, and 0.048kg of PPVE was added to each 1kg of TFE fed, and polymerization was continued for 6.5 hours. TFE was discharged, and after the autoclave was allowed to return to atmospheric pressure, the obtained reaction product was washed with water and dried to obtain 15kg of powder.

The obtained powder was melt-extruded at 360℃by a screw extruder (trade name: PCM46, manufactured by Mitsui Co., ltd.) to obtain pellets of TFE/PPVE copolymer. Using the pellets obtained, the PPVE content was determined by the method described above. The results are shown in Table 3.

The obtained pellets were placed in a vacuum vibration type reaction apparatus VVD-30 (manufactured by Dachuan original manufacturing Co., ltd.), and the temperature was raised to 210 ℃. After evacuation, N for introduction ₂ F gas dilution to 20 vol% ₂ The gas is brought to atmospheric pressure. From F ₂ After 0.5 hour from the time of gas introduction, the mixture was once evacuated and F was introduced again ₂ And (3) gas. After 0.5 hour, the mixture was again evacuated and F was introduced again ₂ And (3) gas. Thereafter, F is as described above ₂ The gas introduction and evacuation operations were continued for 1 time within 1 hour, and the reaction was carried out at 210℃for 10 hours. After the reaction, the inside of the reactor was fully replaced with N ₂ And (3) ending the fluorination reaction by using the gas. Using the fluorinated pellets, various physical properties were measured by the above-described method. The results are shown in Table 3.

Example 2

Fluorinated pellets were obtained in the same manner as in example 1, except that PPVE was changed to 1.48kg, methanol was changed to 0.34kg, and PPVE was changed to 0.050kg added per 1kg of TFE supplied. The results are shown in Table 3.

Example 3

Fluorinated pellets were obtained in the same manner as in example 1, except that PPVE was changed to 1.68kg, methanol was changed to 0.29kg, PPVE was changed to 0.056kg added per 1kg of TFE supplied, the polymerization time was changed to 7 hours, the temperature of the vacuum vibration reactor was changed to 170 ℃, and the reaction temperature was changed to 5 hours at 170 ℃. The results are shown in Table 3.

Example 4

Fluorinated pellets were obtained in the same manner as in example 1 except that 49.0L of pure water, 40.7kg of perfluorocyclobutane, 2.01kg of PPVE, 0.42kg of methanol, 0.64MPa of TFE pressure, 0.041kg of 50% methanol solution of di-n-propyl peroxydicarbonate, 0.059kg of PPVE was added to 1kg of TFE, and the polymerization time was changed to 18.5 hours. The results are shown in Table 3.

Comparative example 1

Fluorinated pellets were obtained in the same manner as in example 1 except that PPVE was changed to 1.76kg, methanol was changed to 0.21kg, PPVE was changed to 0.058kg added per 1kg of TFE supplied, and the polymerization time was changed to 7 hours. The results are shown in Table 3.

Comparative example 2

After filling a 174L-volume autoclave with 51.8L of pure water and sufficiently replacing the pure water with nitrogen, 40.9kg of perfluorocyclobutane, 1.85kg of perfluoro (propyl vinyl ether) (PPVE) and 3.36kg of methanol were charged, the temperature in the system was kept at 35℃and the stirring speed was kept at 200rpm. Subsequently, tetrafluoroethylene (TFE) was introduced under pressure to 0.64MPa, and then 0.051kg of a 50% methanol solution of di-n-propyl peroxydicarbonate was introduced to start polymerization. Since the pressure in the system decreased as polymerization proceeded, TFE was continuously fed so that the pressure became constant, and 0.043kg of PPVE was additionally fed per 1kg of TFE fed. When the additional amount of TFE fed reached 40.9kg, polymerization was terminated. Unreacted TFE was discharged, and after the autoclave was allowed to return to atmospheric pressure, the obtained reaction product was washed with water and dried to obtain 41.0kg of powder.

Using the obtained powder, a fluorination reaction was performed in the same manner as in example 1 to obtain fluorinated pellets. The results are shown in Table 3.

Comparative example 3

Fluorinated pellets were obtained in the same manner as in comparative example 2, except that PPVE was 2.88kg, methanol was 1.56kg, and 0.060kg of PPVE was additionally charged per 1kg of TFE supplied. The results are shown in Table 3.

Comparative example 4

An unfluorinated pellet was obtained in the same manner as in comparative example 2, except that PPVE was 2.43kg, methanol was 1.75kg, and 0.053kg of PPVE was additionally charged per 1kg of TFE supplied.

The obtained pellets were placed in a vacuum vibration reactor VVD-30 (manufactured by Dachuan Yuan Co., ltd.) and N was used ₂ Fully displacing the gas to make F ₂ Gas and N ₂ Mixed gas of gases (F) ₂ Gas concentration 10% by volume) was passed through at a flow rate of 1.0L/min for 3 hours. The reaction apparatus was heated to 170℃and allowed to react for 2 hours. After the reaction, the heating was stopped and switched to N ₂ Gas, F ₂ The gas was fully displaced for about 1 hour. At this time, the temperature was 30 ℃. Then, ammonia gas and N are reacted ₂ The mixed gas of gases (ammonia concentration 50% by volume) was passed through at a flow rate of 2.0L/min for 30 minutes, whereby ammonia treatment was performed. The temperature was room temperature (about 30 ℃). After the treatment, let N ₂ After the gas passes through the outlet until the gas becomes neutral, the reaction apparatus is opened to the atmosphere. Using the obtained pellets, various physical properties were measured by the above-described method. The results are shown in Table 3.

Comparative example 5

Fluorinated pellets were obtained in the same manner as in comparative example 2 except that PPVE was changed to 3.47kg, methanol was changed to 3.28kg, 50% methanol solution of di-n-propyl peroxydicarbonate was changed to 0.026kg, and PPVE was changed to 0.071kg of dry powder 43.8kg of additional feed per 1kg of TFE. The results are shown in Table 3.

TABLE 3

TABLE 3 Table 3

The expression "< 6" in Table 3 means that the number of functional groups is less than 6.

Next, using the obtained pellets, the following characteristics were evaluated. The results are shown in Table 4.

(haze value)

Sheets having a thickness of about 1.0mm were produced using pellets and a hot press molding machine. The sheet was immersed in a quartz dish containing pure water according to JIS K7136 using a haze meter (trade name: NDH7000SP, manufactured by Nippon Denshoku Kogyo Co., ltd.) to measure the haze value.

(tensile Strength at 100 ℃ C. (TS))

Tensile strength at 100℃was measured according to ASTM D638.

(injection moldability)

Condition

The copolymer was injection molded using an injection molding machine (IS 130FI, manufactured by Toshiba machinery Co., ltd.) at a cylinder temperature of 390℃and a mold temperature of 200℃at an injection speed of 5 mm/s. As the mold, a mold (130 mm×130mm×3mmt, side gate, flow length from gate more than 130 mm) in which Cr plating was performed on HPM38 was used. The obtained injection-molded article was observed and evaluated according to the following criteria. The presence or absence of surface roughness was confirmed by contacting the surface of the injection-molded article.

3: the entire surface was smooth, and no flow mark was observed in the entire molded article.

2: the surface was observed to be rough in a range of 1cm from the position of the gate of the mold, but the surface was smooth in the other range, and no flow mark was observed in the entire molded article.

1: roughness was observed on the surface in a range of 1cm from the position of the gate of the mold, and flow marks were observed in a range of 1cm from the position of the gate of the mold, but the surface in the other range was smooth as a whole, and no flow marks were observed.

0: roughness was confirmed on the surface in a range of 4cm from the position of the gate of the mold, and flow marks were observed in a range of 4cm from the position of the gate of the mold.

(electrolyte impregnation test)

About 5g of pellets were put into a mold (inner diameter: 120mm, height: 38 mm), melted at 370℃for 20 minutes by a hot plate press, and then water-cooled while being pressurized by a pressure of 1MPa (resin pressure), to prepare a molded article having a thickness of about 0.2 mm. Thereafter, using the obtained molded article, a 15mm square test piece was produced.

To a 20mL glass sample bottle, 10 pieces of the obtained test piece and 2g of dimethyl carbonate (DMC) were added, and the cap of the sample bottle was closed. The sample bottles were placed in a constant temperature bath at 80℃for 144 hours, whereby the test pieces were immersed in DMC. Then, the sample bottle was taken out of the incubator, cooled to room temperature, and then the test piece was taken out of the sample bottle. DMC remaining after the test piece was taken out was air-dried in a room at 25℃for 24 hours in a state of being placed in a sample bottle, and 2g of ultrapure water was added. The resulting aqueous solution was transferred to a cell of an ion chromatography system, and the fluorine ion content of the aqueous solution was measured by the ion chromatography system (Dionex ICS-2100, manufactured by Thermo Fisher Scientific Co.).

(mold Corrosion test)

20g of pellets were placed in a glass vessel (50 ml screw tube), and a metal column (5 mm square, 30mm in length) formed of HPM38 (Cr-plated) or HPM38 (Ni-plated) was suspended in the glass vessel so as not to contact the pellets. The glass container was then covered with aluminum foil. The glass container was put in an oven in this state and heated at 380℃for 3 hours. Then, the heated glass vessel was taken out of the oven, cooled to room temperature, and the degree of corrosion of the metal column surface was visually observed. The degree of corrosion was determined according to the following criteria.

O: no corrosion was observed

Delta: corrosion was slightly observed

X: corrosion was observed

(wire coating test)

By means ofAn electric wire coating and molding machine (manufactured by Takara Plastic mechanical Co., ltd.) was used to coat a copper conductor having a conductor diameter of 1.00mm with the following coating thicknessExtruding the coated copolymer to obtain a coated wire. The wire coating extrusion molding conditions were as follows.

a) Core conductor: conductor diameter 1.00mm

b) Coating thickness: 0.50mm

c) Coated wire diameter: 2.00mm

d) Wire drawing speed: 7 m/min

e) Extrusion conditions:

single screw extrusion moulding machine with barrel shaft diameter=20mm, l/d=22

Die (inner diameter)/sheet (outer diameter) =30.0 mm/10.0mm

Set temperature of extruder: barrel section C-1 (330 ℃), barrel section C-2 (360 ℃), barrel section C-3 (375 ℃), head section H (390 ℃), die section D-1 (405 ℃) and die section D-2 (395 ℃). The core wire preheating was set at 80 ℃.

(variation of outer diameter)

The outer diameter of the obtained coated wire was measured continuously for 1 hour using an outer diameter measuring instrument (ODAC 18XY manufactured by Zumbach Co.). The measured outer diameter value was rounded off from the predetermined outer diameter value (2.00 mm) by the third decimal point of the maximum outer diameter value, and the fluctuation value of the outer diameter was obtained. The ratio (change rate of the outer diameter) of the absolute value of the difference between the predetermined outer diameter and the change value of the outer diameter to the predetermined outer diameter (2.00 mm) was calculated, and the evaluation was performed according to the following criteria.

(change rate of outer diameter (%)) = | (change value of outer diameter) - (prescribed outer diameter) |/(prescribed outer diameter) ×100

1 percent: the change rate of the outer diameter is less than 1%

2% ± 2%: the change rate of the outer diameter exceeds 1% and is less than 2%

X: the change rate of the outer diameter exceeds 2 percent

(toner Release test)

UsingAn extruder (manufactured by hoku corporation) and a T-die, and a film was produced. Extrusion molding conditions were as follows.

a) Coiling speed: 1 m/min

b) Roller temperature: 120 DEG C

c) Film width: 70mm of

d) Thickness: 0.10mm

e) Extrusion conditions:

single screw extrusion moulding machine with cylinder axis diameter=14 mm and L/d=20

Set temperature of extruder: barrel section C-1 (330 ℃ C.), barrel section C-2 (350 ℃ C.), barrel section C-3 (370 ℃ C.), T die section (380 ℃ C.)

A50 mm by 50mm test piece was cut out from the obtained 0.10mm thick film, the obtained test piece was laid on a SUS bath, 3g of black toner powder was rolled up thereon into a round shape having a diameter of about 30mm, a lid of the bath was covered, and the bath was placed in a constant temperature bath heated to 160℃with the inside being a closed space. After 10 minutes, the cell was taken out, cooled to room temperature, and the test piece was taken out of the cell. The melt-cured product of the black toner was peeled from the test piece, and the peeled surface of the test piece was visually observed, and evaluated according to the following criteria.

O: no black deposit was observed on the peeled surface of the test piece

X: black deposit was observed on the peeled surface of the test piece

(abrasion test)

Using the pellets and a hot press molding machine, a sheet-like test piece having a thickness of about 0.2mm was produced, from which a 10 cm. Times.10 cm test piece was cut. The test piece thus prepared was fixed on a test stand of a taber abrasion tester (No. 101 model taber abrasion tester, manufactured by An Tian refiner manufacturing company), and abrasion test was performed using the taber abrasion tester under conditions of a test piece surface temperature of 150 ℃, a load of 500g, an abrasion wheel CS-10 (20 revolutions ground with grinding paper # 240), and a rotational speed of 60 rpm. The weight of the test piece after 1000 revolutions was measured, and the test piece weight was further measured after 10000 revolutions with the same test piece. The abrasion loss was determined by the following formula.

Abrasion loss (mg) =m1-M2

M1: test piece weight after 1000 revolutions (mg)

M2: weight of 5000 rpm test piece (mg)

(oxygen permeability coefficient)

A sheet-like test piece having a thickness of about 0.1mm was produced using the pellets and a hot press molding machine. Using the obtained test piece, the test piece was prepared according to JIS K7126-1:2006, oxygen permeability was measured using a differential pressure type gas permeability meter (L100-5000 type gas permeability meter, manufactured by Systemech ilinois Co.). Obtaining a permeation area of 50.24cm ² The oxygen permeability at a test temperature of 70℃and a test humidity of 0% RH. Using the obtained oxygen permeation rate and the thickness of the test piece, the oxygen permeation coefficient was calculated by the following formula.

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

GTR: oxygen permeability (cm) ³ /(m ² ·24h·atm))

d: test piece thickness (mm)

(electrolyte permeability)

A sheet-like test piece having a thickness of about 0.2mm was produced using the pellets and a hot press molding machine. In a test cup (permeation area 12.56 cm) ² ) 10g of dimethyl carbonate (DMC) was placed therein, covered with a sheet-like test piece, and fastened and sealed with a PTFE gasket interposed therebetween. The pellet was allowed to contact DMC, kept at 60℃for 30 days, and then taken out, and left at room temperature for 1 hour to measure the mass reduction. The DMC permeability (g.cm/m) was determined by ² )。

Electrolyte permeability (g.cm/m) ² ) =mass reduction amount (g) ×thickness (cm)/transmission area (m) of sheet-like test piece ² )

(methyl ethyl ketone (MEK) transmittance)

A sheet-like test piece having a thickness of about 0.1mm was produced using the pellets and a hot press molding machine. In a test cup (permeation area 12.56 cm) ² ) 10g of MEK was added thereto, and the mixture was covered with a sheet-like test piece, and fastened and sealed with a PTFE gasket interposed therebetween. The sheet-like test piece was brought into contact with MEK, kept at a temperature of 60℃for 60 days, taken out, and left at room temperature for 1 hour to measure the mass reduction. The MEK transmittance (mg.cm/m) was determined by the following formula ² Day).

MEK transmittance (mg cm/m) ² Day) = [ mass reduction (mg) ×sheet testThickness of sheet (cm)]Transmission area (m) ² ) Days (Tian)]

(95 ℃ C. Load deflection rate)

Using the pellets and a hot press molding machine, a sheet-like test piece having a thickness of about 3mm was produced, from which a test piece having a thickness of 80X 10mm was cut, and heated at 100℃for 20 hours by an electric furnace. The test was carried out using a thermal deformation tester (manufactured by An Tian refiner) according to the method described in JIS K-K7191, except for the test piece obtained, under conditions of a test temperature of 30 to 150 ℃, a temperature rising rate of 120 ℃/hr, a bending stress of 1.8MPa, and a flat-bed (flat-bed) method. The load deflection was obtained by the following method. The sheet having a small deflection under load at 95℃has excellent rigidity at high temperatures.

Load deflection (%) =a2/a1×100

a1: thickness of test piece before test (mm)

a2: deflection (mm) at 95 DEG C

(ozone exposure test)

The copolymer was compression molded at 350℃under a pressure of 0.5MPa to prepare a sheet having a thickness of 1mm, from which a 10X 20mm sample was cut out to prepare a sample for ozone exposure test. Ozone gas (ozone/oxygen=10/90 vol%) generated by an ozone generating apparatus (trade name: SGX-a11MN (modified), manufactured by sumitomo fine industries, co.) was connected to a container made of PFA containing ion-exchanged water, and after bubbling the ion-exchanged water and adding steam to the ozone gas, the sample was exposed to humid ozone gas at room temperature through a tank made of PFA containing the sample at 0.7 liter/min. After 180 days from the initial exposure, the sample was taken out, the surface was lightly rinsed with ion-exchanged water, and then a portion having a depth of 5 μm to 200 μm from the sample surface was observed at a magnification of 100 times by using a transmission optical microscope, taken together with a standard scale, and the surface of the sample was measured every 1mm ² The number of cracks having a length of 10 μm or more was evaluated according to the following criteria.

O: the number of cracks is less than 10

X: the number of cracks is more than 10

(evaluation of creep resistance)

Determination of creep resistance according to ASTM D395 or JIS K6262: 2013. A molded article having an outer diameter of 13mm and a height of 8mm was produced using pellets and a hot press molding machine. The obtained molded article was cut to prepare a test piece having an outer diameter of 13mm and a height of 6 mm. The test piece thus produced was compressed to a compression set of 25% at normal temperature using a compression device. The compressed test piece was left standing in an electric furnace at 80℃for 72 hours in a state of being fixed to a compression device. The compression device was taken out of the electric furnace, cooled to room temperature, and then the test piece was taken out. After the recovered test piece was left at room temperature for 30 minutes, the height of the recovered test piece was measured, and the recovery ratio was determined by the following formula.

Recovery ratio (%) = (t) ₂ －t ₁ )/t ₃ ×100

t ₁ : height of spacer (mm)

t ₂ : height (mm) of test piece removed from compression device

t ₃ : height after compression deformation (mm)

In the above test, t ₁ ＝4.5mm，t ₃ ＝1.5mm。

(tube formability)

Using the pellets obtained in the examplesAn extrusion molding machine (field plastic machine manufacturing) extrusion-molded a tube having an outer diameter of 10.0mm and a wall thickness of 1.0 mm.

Extrusion molding conditions were as follows.

a) Die inside diameter: 20mm of

b) Mandrel outside diameter: 13mm of

c) Sizing die inner diameter: 10.5mm

d) Traction speed: 0.4 m/min

e) Outer diameter: 10.0mm

f) Wall thickness: 1.0mm

g) Extrusion conditions:

single screw extrusion moulding machine with cylinder shaft diameter=30 mm, L/d=22

Set temperature of extruder: barrel part C-1 (330 ℃ C.), barrel part C-2 (365 ℃ C.), barrel part C-3 (380 ℃ C.), head part H-1 (380 ℃ C.), die part D-1 (390 ℃ C.), die part D-2 (390 ℃ C.)

The obtained tube was observed and evaluated according to the following criteria. The appearance of the tube was visually confirmed.

O: good appearance

X: the cross section was not circular, and the appearance was poor due to flattening, uneven thickness, and the like.

(dielectric loss tangent)

The pellets were melt-molded to prepare a cylindrical test piece having a diameter of 2 mm. The test piece thus fabricated was set in a cavity resonator for 6GHz manufactured by kanto electronics application development company, and measured by a network analyzer manufactured by agilent technologies. The measurement result was analyzed by analysis software "CPMA" manufactured by Kanto electronic application development Co., ltd. On a personal computer connected to the network analyzer, to thereby determine the dielectric loss tangent (tan. Delta.) at 20℃and 6 GHz.

TABLE 4

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Claims

1. A copolymer comprising tetrafluoroethylene units and perfluoro (propyl vinyl ether) units,

the content of perfluoro (propyl vinyl ether) unit is 4.4 to 6.0 mass% relative to the total monomer units,

the melt flow rate at 372 ℃ is 7.5g/10 min-11.0 g/10 min,

the number of functional groups per 10 ⁶ The number of carbon atoms of the main chain is 40 or less.

2. An injection molded article comprising the copolymer of claim 1.

3. A coated wire comprising a coating layer comprising the copolymer according to claim 1.

4. A molded body comprising the copolymer of claim 1, wherein the molded body is a flowmeter housing, a film, a bottle, a wire coating, or a tube.