Copolymer, composition and molded article

Abstract

Provided are a copolymer, a composition, and a molded article which are capable of forming a molded article having excellent tensile strength after a chemical resistance test, tensile strength after a thermal aging test, and tensile elongation after the thermal aging test. This copolymer contains a unit based on tetrafluoroethylene, a unit based on ethylene, and either or both of a unit based on a compound represented by formula (1) and a unit based on a compound represented by formula (2), the total content of the tetrafluoroethylene-based units and the ethylene-based units is 80.0-98.1 mol% with respect to the total units contained in the copolymer; the content of the tetrafluoroethylene-based unit is 49.0 mol% or more and less than 56.0 mol% with respect to the total content of the tetrafluoroethylene-based unit and the ethylene-based unit; the content of the unit based on the compound represented by formula (1) or the unit based on the compound represented by formula (2) is 1.9 mol% or more and less than 3.2 mol% with respect to the total units contained in the copolymer, and the melt flow rate of the copolymer measured under the conditions of a temperature of 297 DEG C and a load of 49 N in accordance with ASTM D3159 is 33-50 g / 10 minutes. Formula (1): CZ2 = CX (CF2) mY, and Formula (2): CF2 = CF-O-(CF2) nF.

Description

TECHNICAL FIELD

[0001] The present application relates to a copolymer, a composition, and a molded body. BACKGROUND

[0002] Ethylene / tetrafluoroethylene copolymer (hereinafter also referred to as "ETFE") not only has excellent heat resistance, weather resistance, electrical insulation, non-adhesion, water / oil repellency, and the like, but also has characteristics of high moldability and mechanical strength among fluororesins. Therefore, it is manufactured into various molded bodies such as a coating of electric wire, a tube, a sheet, a film, a filament, a pump housing, a joint, a package, an inner liner, a coating, and the like by a melt molding method such as extrusion molding, blow molding, injection molding, rotational molding, and the like.

[0003] For example, Patent Literature 1 discloses a polymer composition containing a copolymer having an ethylene repeating unit, a tetrafluoroethylene repeating unit, and another repeating unit.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Specification of Chinese Patent Application Publication No. 104151754 SUMMARY

[0007] PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] In the case of using ETFE as a constituent material of a molded body, it is required to have excellent characteristics such as chemical resistance, heat resistance, and mechanical strength.

[0009] The present inventors evaluated a molded body formed with ETFE described in Patent Literature 1, and as a result, found that there is still room for improvement in terms of chemical resistance and heat resistance, particularly in terms of tensile strength after a chemical resistance test, tensile strength after a heat aging test, and tensile elongation after a heat aging test.

[0010] Thus, the present application aims to provide a copolymer capable of forming a molded body having excellent tensile strength after a chemical resistance test, tensile strength after a heat aging test, and tensile elongation after a heat aging test. In addition, the present application aims to provide a composition containing the above-described copolymer, and a molded body obtained by molding the above-described copolymer.

[0011] MEANS OF SOLVING THE PROBLEMS

[0012] The inventors have carefully studied the above-mentioned technical problems and found that by using a copolymer containing tetrafluoroethylene-based units, ethylene-based units, and units based on compounds represented by the following formula (1) or compounds represented by the following formula (2), and with the content of each unit within a specified range and a melt flow rate of 33 to 50 g / 10 minutes, it is possible to form a molded body with excellent tensile strength after chemical resistance test, tensile strength after heat aging test, and tensile elongation after heat aging test, thereby completing the present invention.

[0013] That is, the inventors discovered that the above-mentioned technical problems can be solved by the following configuration.

[0014] [1] A copolymer comprising any one or both of tetrafluoroethylene-based units, ethylene-based units, and units based on a compound represented by formula (1) and a compound represented by formula (2) described below, wherein the total content of the tetrafluoroethylene-based units and the ethylene-based units is 80.0 to 98.1 mol% relative to all units contained in the copolymer, the content of the tetrafluoroethylene-based units is more than 49.0 mol% and less than 56.0 mol% relative to the total content of the tetrafluoroethylene-based units and the ethylene-based units, the content of the units based on the compound represented by formula (1) or the units based on the compound represented by formula (2) described below is more than 1.9 mol% and less than 3.2 mol% relative to all units contained in the copolymer, and the melt flow rate of the copolymer, as determined by ASTM D3159 at a temperature of 297°C and a load of 49 N, is 33 to 50 g / 10 min.

[0015] [2] The copolymer as described in [1] comprises the tetrafluoroethylene-based unit, the ethylene-based unit, and the unit based on the compound represented by formula (1), wherein the content of the unit based on the compound represented by formula (1) is more than 1.9 mol% and less than 3.2 mol% relative to all units contained in the copolymer.

[0016] [3] A composition comprising the copolymer described in [1] or [2].

[0017] [4] A solid composition comprising the copolymer described in [1] or [2], wherein the TOC (total organic carbon) leaching amount is 1000–63000 μg / cm³. 2 .

[0018] [5] A solid composition comprising the copolymer described in [1] or [2], having a water content of 0.02 to 0.8% by mass.

[0019] [6] A molded body obtained by molding the copolymer described in [1] or [2].

[0020] [7] A molded body obtained by molding the composition described in [3].

[0021] [8] A molded body obtained by molding the solid composition described in [4].

[0022] Invention Effects

[0023] According to the present invention, a copolymer capable of forming a molded article with excellent tensile strength after a chemical resistance test, tensile strength after a heat aging test, and tensile elongation after a heat aging test can be provided. Furthermore, according to the present invention, a composition comprising the above-mentioned copolymer, and a molded article obtained by molding the above-mentioned copolymer, can be provided. Detailed Implementation

[0024] The meanings of the terms used in this invention are as follows.

[0025] The range of values ​​represented by “~” refers to the range containing the values ​​recorded before and after “~” as the lower and upper limits.

[0026] "Unit" refers to the collective term for atomic groups derived directly from the monomer molecule formed by monomer polymerization and atomic groups obtained by chemical transformation of a portion of the aforementioned atomic groups. Additionally, in the following text, depending on the circumstances, units derived from each monomer may sometimes be referred to by the name of that monomer followed by the term "unit".

[0027] “TFE unit” refers to the tetrafluoroethylene-based unit of the copolymer, and “E unit” refers to the ethylene-based unit of the copolymer. In addition, “A unit” refers to the unit based on the compound represented by formula (1) or formula (2).

[0028] [Copolymer]

[0029] The copolymer of the present invention (hereinafter also referred to as "this copolymer") comprises E units, TFE units, and A units respectively within specified ranges. Furthermore, the melt flow rate of this copolymer, as determined according to ASTM D3159 at a temperature of 297°C and a load of 49N, is 33–50 g / 10 minutes.

[0030] This copolymer can form molded articles with excellent tensile strength after chemical resistance testing, tensile strength after heat aging testing, and elongation after heat aging testing. The detailed reasons are not yet clear, but the following are speculated.

[0031] In this specification, the tensile strength after the chemical resistance test is evaluated based on the retention rate of tensile strength before and after immersion in chemicals, after the molded body obtained from the copolymer has been immersed in chemicals for an extended period. Similarly, the tensile strength and elongation after the heat aging test are evaluated based on the rate of change of tensile strength and elongation before and after the heat aging test, respectively, after the heat aging test of the molded body obtained from the copolymer.

[0032] One of the reasons why this copolymer can form the molded articles with the above-mentioned excellent chemical resistance and heat resistance is that it uses a copolymer in which the content of A unit based on the compound represented by formula (1) or formula (2) is more than 1.9 mol% and less than 3.2 mol% relative to all units contained in the copolymer, and the melt flow rate is 33 to 50 g / 10 min.

[0033] That is, it is speculated that since the content of unit A is more than 1.9 mol% relative to all units contained in the copolymer, even if it cannot be guaranteed that the molded body will not melt in the heat aging test, it can suppress the decrease in high temperature tensile properties. Therefore, for the molded body formed, it can suppress the change in tensile elongation after the heat aging test.

[0034] Furthermore, it is speculated that since the content of unit A is less than 3.2 mol% relative to all units contained in the copolymer, the melting point of the copolymer will not decrease, and the melting of the molded body can be suppressed in the heat aging test. Therefore, for the molded body formed, the decrease in tensile strength after the heat aging test can be suppressed.

[0035] It is speculated that since the melt flow rate is above 33g / 10min, the melt flow rate will not be too low, thus resulting in excellent formability. For the formed molded body, it can suppress the change in tensile elongation after the heat aging test.

[0036] It is speculated that since the melt flow rate is below 50g / 10min, the melt flow rate will not be too high, which can suppress the decomposition caused by long-term chemical immersion. Therefore, for the formed molded body, it can suppress the decrease in tensile strength after the chemical resistance test.

[0037] Therefore, it is believed that by specifying the content of unit A and the melt flow rate, molded articles with excellent chemical resistance and heat resistance can be obtained.

[0038] This copolymer is a copolymer comprising TFE units based on tetrafluoroethylene, E units based on ethylene, and A units, which are either units based on compounds represented by formula (1) or units based on compounds represented by formula (2).

[0039] CZ2=CX(CF2) mY formula (1)

[0040] CF2 = CF - O - (CF2) n Formula F (2)

[0041] In equation (1), X, Y and Z each independently represent a hydrogen atom or a fluorine atom, and m represents an integer from 2 to 6.

[0042] In equation (2), n represents an integer from 1 to 6.

[0043] In the compound represented by formula (1), from the perspective of polymerizability, X and Z are preferably hydrogen atoms.

[0044] From the perspective of heat resistance, Y is preferably composed of fluorine atoms.

[0045] m is preferably 2 to 6, and more preferably 4.

[0046] As the compound represented by formula (1), CH2=CH(CF2)2F, CH2=CH(CF2)4F, CH2=CH(CF2)6F, CH2=CF(CF2)4F or CH2=CF(CF2)3H are preferred, and CH2=CH(CF2)4F (hereinafter also referred to as "PFBE").

[0047] Specific examples of compounds represented by formula (2) include any one of CF2=CF-O-(CF2)F, CF2=CF-O-(CF2)2F, CF2=CF-O-(CF2)3F, CF2=CF-O-(CF2)4F, CF2=CF-O-(CF2)5F, and CF2=CF-O-(CF2)6F. Among them, CF2=CF-O-(CF2)3F, which corresponds to the compound with n=3, is preferred.

[0048] In this copolymer, the A unit may include one of the units based on the compound represented by formula (1) (hereinafter also referred to as "A1 unit") and the units based on the compound represented by formula (2) (hereinafter also referred to as "A2 unit"), or both A1 unit and A2 unit may be included.

[0049] That is, when the copolymer contains both A1 units and A2 units, "A unit content" refers to the sum of the content of A1 units and the content of A2 units.

[0050] The content of unit A is more than 1.9 mol% and less than 3.2 mol% relative to all units contained in this copolymer.

[0051] Since the content of unit A is more than 1.9 mol% relative to all units contained in the copolymer, it is possible to form a molded body with excellent tensile elongation and optical properties after heat aging test.

[0052] Furthermore, since the content of unit A is less than 3.2 mol% relative to all units contained in the copolymer, it is possible to form a molded body with excellent tensile strength after heat aging test and excellent tensile strength after chemical resistance test.

[0053] Considering the excellent and well-balanced tensile strength, tensile strength, and tensile elongation after chemical resistance tests, as well as the heat aging resistance tests, the content of unit A relative to all units contained in the copolymer is preferably 1.9 to 3.0 mol.

[0054] As this copolymer, a copolymer containing TFE units, E units and A1 units or a copolymer containing TFE units, E units and A2 units is preferred. From the perspective of excellent long-term folding resistance, a copolymer containing E units, TFE units and A1 units is more preferred.

[0055] When this copolymer is a copolymer containing TFE units, E units and Al units, the content of Al units is 1.9 mol% or more and less than 3.2 mol% relative to all units contained in the copolymer, and preferably 1.9 to 3.0 mol%.

[0056] When this copolymer is a copolymer containing TFE units, E units and A2 units, the content of A2 units is 1.9 mol% or more and less than 3.2 mol% relative to all units contained in the copolymer, and preferably 1.9 to 3.1 mol%.

[0057] In this copolymer, the total content of TFE units and E units is 80.0 to 98.1 mol% relative to all units contained in the copolymer.

[0058] From the perspective of excellent long-term heat resistance, the total content of TFE units and E units is preferably 85.0 mol% or more, more preferably 88.0 mol% or more. Furthermore, from the perspective of excellent durability under repeated loads, the total content of TFE units and E units is preferably 97.0 mol% or less.

[0059] In this copolymer, the content of TFE units is more than 49.0 mol% and less than 56.0 mol% relative to the total content of TFE units and E units.

[0060] From the perspective of excellent heat resistance, the content of TFE unit relative to the total content of TFE unit and E unit is preferably 50.0 mol% or more and less than 56.0 mol%, more preferably 52.0 mol% or more and less than 56.0 mol%.

[0061] The content of TFE units relative to all units contained in the copolymer is preferably 40.0 to 54.9 mol%, more preferably 45.0 to 54.5 mol%, and particularly preferably 50.0 to 54.5 mol%. If the content is above the lower limit, the heat resistance of the molded article is better, and if the content is below the upper limit, the mechanical properties of the molded article are better.

[0062] The content of E units relative to all units contained in the copolymer is preferably 36.0 to 50 mol%, more preferably 40.0 to 48.0 mol%, and particularly preferably 42.0 to 47.0 mol%. If the content is above the lower limit, the mechanical properties of the molded article are better, and if the content is below the upper limit, the heat resistance of the molded article is better.

[0063] This copolymer may also contain units of monomers other than tetrafluoroethylene, ethylene, compounds represented by formula (1) and compounds represented by formula (2).

[0064] Specific examples of other monomers include: fluoroolefins (fluoroethylene, vinylidene fluoride, trifluoroethylene, hexafluoropropylene, hexafluoroisobutylene, etc.; but excluding compounds represented by formula (1) and compounds represented by formula (2), CF2=CFOR f1 SO2X 1 (where R) f1 It is a perfluoroalkylene group with 1 to 10 carbon atoms, and may contain oxygen atoms between the carbon atoms. 1 (It is a halogen atom or hydroxyl group), CF2=CFOR f2 CO2X 2 (where R) f2 It is a perfluoroalkylene group with 1 to 10 carbon atoms, and may contain oxygen atoms between the carbon atoms. 2 It consists of hydrogen atoms or alkyl groups having 1 to 3 carbon atoms, CF2=CF(CF2). p OCF=CF2 (where p is 1 or 2), fluorinated monomers with cyclic structures (perfluoro(2,2-dimethyl-1,3-dioxacyclopentene), 2,2,4-trifluoro-5-trifluoromethoxy-1,3-dioxacyclopentene, perfluoro(2-methylene-4-methyl-1,3-dioxacyclopentene), etc.); as well as itaconic acid, itaconic anhydride, citraconic acid and citraconic anhydride.

[0065] When the copolymer contains units based on other monomers, the content of units based on other monomers is preferably less than 2.0 mol% and more preferably less than 1.0 mol% relative to all units contained in the copolymer.

[0066] The copolymer is preferably composed of TFE units, E units and A units, and more preferably composed of TFE units, E units and Al units.

[0067] Melt flow rate

[0068] The melt flow rate (hereinafter also referred to as "MFR") of this copolymer is 33-50 g / 10 min.

[0069] Because the MFR of this copolymer is above 33 g / 10 min, it is possible to form molded articles with excellent elongation after heat aging test, as well as excellent tensile strength and optical properties after chemical resistance test.

[0070] Furthermore, since the MFR of this copolymer is less than 50 g / 10 min, it is possible to form molded articles with excellent tensile strength and excellent elongation after chemical resistance tests.

[0071] Considering the excellent and well-balanced tensile strength, tensile strength, and elongation after the chemical resistance test, as well as the heat aging test, the MFR of this copolymer is preferably 33-48 g / 10 min.

[0072] As a specific example of a method to bring the MFR of this copolymer within the above-mentioned range, a method for adjusting the molecular weight of this copolymer can be cited. The larger the molecular weight of this copolymer, the smaller the MFR.

[0073] The MFR of this copolymer refers to the mass of this copolymer that flows out of an orifice with a diameter of 2 mm and a length of 8 mm within 10 minutes, as measured according to ASTM D3159 at a temperature of 297°C and a load of 49 N.

[0074] Furthermore, since the MFR is above 33 g / 10 min and the content of A1 unit is above 1.9 mol% relative to all units contained in the copolymer, this copolymer can form molded articles with excellent optical properties (especially haze).

[0075] Melting point

[0076] From the perspective of superior crack resistance, the melting point of this copolymer is preferably above 245°C, more preferably above 248°C, and particularly preferably above 249°C.

[0077] Furthermore, from the perspective of the excellent formability of this copolymer, the melting point of this copolymer is preferably below 290°C, more preferably below 280°C, and particularly preferably below 270°C.

[0078] As specific examples of methods to bring the melting point of the copolymer within the above-mentioned range, methods such as lowering the polymerization temperature during the manufacture of the copolymer or adjusting the content of A units in the copolymer can be cited.

[0079] The melting point of this copolymer is the temperature corresponding to the endothermic peak after heating the copolymer in air at a rate of 10°C / min using a differential scanning calorimeter.

[0080] <Manufacturing Method>

[0081] This copolymer can be manufactured using the monomers described above (ethylene, tetrafluoroethylene, one or both of the compounds represented by formula (1) and the compounds represented by formula (2)) by known methods such as bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc., with solution polymerization being preferred.

[0082] In addition to the monomers mentioned above, polymerization initiators, polymerization media, chain transfer agents, etc., can also be used in the manufacture of this copolymer.

[0083] The polymerization initiator is preferably a free radical polymerization initiator with a half-life of 10 hours and a temperature of 0–100°C, and particularly preferably a free radical polymerization initiator with a temperature of 20–90°C. Specific examples of polymerization initiators include various polymerization initiators illustrated in International Publication No. 2013 / 015202.

[0084] Polymerization initiators can be used alone or in combination of two or more.

[0085] The amount of polymerization initiator used relative to 100 parts by mass of monomer is preferably 0.01 to 0.9 parts by mass, and particularly preferably 0.05 to 0.5 parts by mass.

[0086] Perfluorocarbons, hydrofluorocarbons, hydrofluoroethers, etc., can be used as polymerization media. Specific examples of polymerization media can be cited in International Publication No. 2013 / 015202.

[0087] The polymerization medium can be used alone or in combination of two or more.

[0088] The amount of polymerization medium used is preferably 5 times or more, more preferably 7 times or more, by mass ratio to the amount of monomer used. Furthermore, it is preferably 20 times or less, more preferably 17 times or less.

[0089] Considering the large chain transfer coefficient and low addition amount, the following chain transfer agents are preferred as chain transfer agents: alcohols such as methanol, ethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoropropanol, 1,1,1,3,3,3-hexafluoroisopropanol, and 2,2,3,3,3-pentafluoropropanol; hydrocarbons such as n-pentane, n-hexane, and cyclohexane; hydrofluorocarbons such as CF2H2; ketones such as acetone; thiols such as methanethiol; esters such as methyl acetate and ethyl acetate; and ethers such as diethyl ether and methyl ethyl ether.

[0090] From the perspective of higher chain transfer constant and higher stability of the terminal groups of the copolymer, at least one of alcohols, hydrocarbons, and hydrofluorocarbons is preferred, more preferably at least one of alcohols and hydrocarbons, and particularly preferably alcohols. Among alcohols, methanol or ethanol is particularly preferred. Methanol is particularly preferred from the perspective of reactivity and ease of acquisition. Two or more chain transfer agents can be used.

[0091] The amount of chain transfer agent used is preferably 0.001 times or more, more preferably 0.005 times or more, by mass ratio to the amount of monomer used. Furthermore, it is preferably 5 times or less, more preferably 4 times or less.

[0092] The polymerization temperature is preferably 15–60°C, more preferably 20–58°C, and particularly preferably 25–55°C. Polymerization properties are excellent when the polymerization temperature is above 15°C. The melting point of the copolymer can be increased when the polymerization temperature is below 60°C.

[0093] The polymerization pressure is preferably 0.5 to 3.0 MPa, and particularly preferably 0.9 to 2.5 MPa.

[0094] The preferred polymerization time is 1 to 12 hours.

[0095] [Composition]

[0096] The composition of the present invention (hereinafter also referred to as "the composition") comprises the above-described copolymer. Because the composition comprises the copolymer, it is possible to form molded articles with excellent tensile strength after chemical resistance testing, tensile strength after heat aging testing, and elongation after heat aging testing by using the composition.

[0097] The content of this copolymer relative to the total mass of the composition is preferably 50% by mass or more and less than 100% by mass, more preferably 70% by mass or more and less than 100% by mass, and particularly preferably 90% by mass or more and less than 100% by mass.

[0098] [Solid Composition]

[0099] The solid composition of the present invention (hereinafter also referred to as "the solid composition") comprises the copolymer, and the TOC (total organic carbon) leaching amount is 1000 to 63000 μg / cm² relative to the surface area of ​​the solid composition. 2 Considering the improvement in bond strength after the hot water resistance test, the TOC leaching amount is preferably below 50,000, more preferably below 30,000. Considering the improvement in tensile strength after the heat aging test, the TOC leaching amount is preferably above 2,000, more preferably above 5,000.

[0100] As a specific example of a method to bring the TOC leaching amount of this solid composition within the above-mentioned range, a method for adjusting the purity of the water used in the granulation of this copolymer and the moisture content of the copolymer can be cited.

[0101] This solid composition contains the copolymer, and the water content relative to the mass of the solid composition is preferably 0.02 to 0.8% by mass. Considering the reduction of TOC leaching, the water content is preferably 0.5% by mass or less, more preferably 0.3% by mass or less. Considering the improvement of tensile strength after heat aging tests, the water content is preferably 0.03% by mass or more, more preferably 0.04% by mass or more.

[0102] As a specific example of a method to bring the moisture content of the solid composition within the above-mentioned range, an adjustment method such as extending the time of maintaining the temperature at or above 100°C during drying after granulation of the copolymer can be cited.

[0103] <Other Ingredients>

[0104] This composition may also contain other components besides those described above. Specific examples of such other components include other resins besides this copolymer, heat stabilizers, antioxidants, colorants, ultraviolet absorbers, fillers, crosslinking agents, crosslinking aids, and organic peroxides.

[0105] When the composition contains other components, the content of the other components is preferably 0.0000001 to 70 parts by weight relative to 100 parts by weight of the copolymer in the composition, more preferably 0.0000005 to 60 parts by weight, and particularly preferably 0.000001 to 50 parts by weight.

[0106] As a method for manufacturing this composition, an example is a method of melt-blending the copolymer and the above-mentioned components used as needed by a known method.

[0107] [molded body]

[0108] The molded article of the present invention can be obtained by molding the above-described copolymer or the above-described composition. The molded article contains the copolymer, and therefore exhibits excellent tensile strength after chemical resistance testing, tensile strength after heat aging testing, and elongation after heat aging testing.

[0109] Specific examples of molding methods include injection molding, extrusion molding, blow molding, compression molding, rotational molding, and electrostatic coating. The molded body is preferably formed by compression molding. Furthermore, injection molding is preferred from the perspective of obtaining an injection-molded body with a beautiful appearance without corroding the molding die.

[0110] Specific examples of the molded bodies of the present invention include nuts, bolts, joints, membranes, bottles, gaskets, wire sheaths, tubes, hoses, pipes, valves, sheets, seals, encapsulations, cans, rollers, containers, stopcocks, connectors, filter housings, filter cages, flow meters, pumps, wafer carriers, and wafer boxes.

[0111] This copolymer, this composition, or the molded article described above may be used for the following purposes.

[0112] Food packaging films, lining materials for fluid transport lines used in food manufacturing processes, encapsulation components, sealing materials, and sheet materials, etc., are fluid transport components used in food manufacturing equipment.

[0113] Drug stoppers, packaging films, lining materials for fluid transport lines used in drug manufacturing processes, encapsulation components, sealing materials, and sheet-like components for transporting liquid drugs;

[0114] Inner lining components for pharmaceutical tanks and piping in chemical or semiconductor plants;

[0115] O-rings, square rings, pipes, seals, valve cores, hoses and sealing materials used in automobile fuel systems and peripheral devices, as well as hoses and sealing materials used in automobile AT systems and other fuel delivery components.

[0116] Flange gaskets, shaft seals, valve stem oil seals, sealing materials and hoses used in automobile engines and peripheral devices, as well as other automobile components such as brake hoses, air conditioning hoses, radiator hoses and wire sheathing materials;

[0117] O-rings, square rings, tubes, packages, valve cores, hoses, sealing materials, rollers, gaskets, diaphragms, and connectors are all chemical transport components used in semiconductor manufacturing equipment.

[0118] Coating and ink components for coating equipment, such as coating rollers, hoses, tubes, and ink containers;

[0119] Food and beverage tubing or flexible tubing, as well as hoses, belts, sealing components and connectors, food packaging materials, and glass cooking equipment;

[0120] Components for waste liquid transportation, such as pipes and hoses.

[0121] Pipes and hoses, and other components for transporting high-temperature liquids;

[0122] Steam piping components, such as pipes and hoses for steam piping;

[0123] Corrosion-resistant tape for piping, such as the tape wound around the piping on the deck of a ship;

[0124] Various coating materials, such as wire coating materials, optical fiber coating materials, and transparent surface coating materials and back coating materials applied to the light incident side surface of photovoltaic elements of solar cells;

[0125] The diaphragm and various encapsulation components of the diaphragm pump;

[0126] Agricultural films, fuel cell carrier membranes, and various roofing and sidewall weathering materials;

[0127] Interior decoration materials used in the construction industry, as well as glass covering materials such as non-combustible fireproof safety glass; and lining materials such as laminated steel plates used in the home appliance industry.

[0128] Among them, considering the excellent tensile strength after chemical resistance test, tensile strength after heat aging test, and tensile elongation after heat aging test of the molded body, the liquid transport component and coating material for semiconductor devices are particularly preferred.

[0129] Example

[0130] The present invention will now be described in detail with examples. Examples 1 to 12 are embodiments, and Examples 13 to 18 are comparative examples. However, the present invention is not limited to these examples.

[0131] The various measurement and evaluation methods are described below.

[0132] [Proportions of each unit]

[0133] The content (mol%) of each unit in the copolymer is determined by... 19 The content of E units in the copolymer was calculated using F-NMR measurements. 1 H-NMR measurements and 13 The result was calculated using C-NMR measurements.

[0134] [MFR (Mel Flow Rate)]

[0135] The mass (g) of copolymer flowing out of an orifice with a diameter of 2 mm and a length of 8 mm within 10 minutes was determined using a melt indexer (manufactured by Techno7 Co., Ltd.) according to ASTM D3159 at a temperature of 297°C and a load of 49 N. This mass is the MFR (g / 10 minutes).

[0136] [Melting Point]

[0137] The melting point (°C) of the copolymer was determined using a differential scanning calorimeter (trade name "DSC7020", manufactured by Hitachi High Technology Co., Ltd.) by heating the copolymer to 300°C in air at a rate of 10°C / min, based on the endothermic peak.

[0138] <Membrane Formation>

[0139] The copolymers obtained in each example were press-molded within a range of +50°C ± 20°C (for example, 280°C to 320°C if the copolymer's melting point is 250°C) to obtain films with a thickness of 200 μm and 1 mm. The press-molding was performed using a hot press (TESTER Sangyo Co., Ltd. "SA-301").

[0140] The obtained membrane was used to conduct the following evaluation tests.

[0141] <Heat resistance>

[0142] Dumbbell-shaped test pieces, as specified in JIS K6301 No. 3, were cut from the obtained 1 mm thick film. For these test pieces, following the ASTM D-3159 method, a STROGRAPH (manufactured by Toyo Seiki Co., Ltd.) was used, with the distance between the gripping fixtures set to 35 mm. The pieces were stretched at a tensile speed of 200 mm / min at room temperature (temperature 23±2℃) to determine the tensile elongation (in %).

[0143] The test piece was placed in a gear oven (forced circulation air heating aging test chamber) (manufactured by Toyo Seiki Co., Ltd.) for heat exposure treatment. The temperature was set at 250°C, and the heat treatment lasted for 24 hours. The tensile elongation was measured for the heat-treated test piece in the same manner as described above. The tensile elongation before heat treatment was set as 100%, and the ratio of the tensile elongation after heat treatment was calculated and evaluated according to the following criteria.

[0144] (Evaluation criteria for tensile elongation)

[0145] ○: The elongation at break after the heat aging test is above 50%.

[0146] △: The tensile elongation after the heat aging test is above 15% and less than 50%.

[0147] ×: Tensile elongation after heat aging test is less than 15%.

[0148] <Optical properties (haze)>

[0149] According to JIS K7105, the haze (haze value, unit: %) of a 200 μm thick film was measured using a haze meter (manufactured by Nippon Seiko Co., Ltd., model: SEP-T).

[0150] Based on the measured haze values, the optical properties of each film are evaluated according to the following evaluation criteria.

[0151] (Optical property evaluation criteria)

[0152] ○: Haze level is less than 10.0%.

[0153] ×: Haze is above 10.0%.

[0154] Chemical Resistance

[0155] The tensile strength of the film obtained by the above-described pressure forming was determined according to ASTM D-3159.

[0156] Dumbbell-shaped test pieces, as specified in ASTM-D638 Type V, were cut from the obtained 1 mm thick film. For the obtained test pieces, a STROGRAPH (manufactured by Toyo Seiki Co., Ltd.) was used, with the distance between the gripping fixtures set to 35 mm. The pieces were stretched at a tensile speed of 200 mm / min at room temperature (23 ± 2 °C) to determine the tensile strength (unit: MPa) of the test pieces before the chemical resistance test.

[0157] Similarly, test pieces in the dumbbell shape specified in ASTM-D638 Type V were cut from the obtained 1 mm thick film.

[0158] The chemicals and test pieces were placed in a clean pressure vessel with a PTFE inner cylinder. The pressure vessel was then sealed, and the test pieces were immersed in the chemicals at 60°C for 168 hours (7 days). Afterward, the test pieces were removed, cooled to 23°C, and the tensile strength of the test pieces after the chemical resistance test was determined according to the method described above. The tensile strength retention rate (%) before and after the chemical resistance test was calculated based on the ratio of the tensile strength of the test pieces after the test to that before the test.

[0159] Ethyl acetate, methyl isobutyl ketone, and butyl cellosolve were selected as the chemicals, and immersion tests were conducted using each chemical. The tensile strength retention rate before and after the test was calculated. The tensile strength retention rate obtained with the three chemicals was taken as the arithmetic mean. Based on the average value, the chemical resistance of each film was evaluated according to the following evaluation criteria.

[0160] (Chemical resistance evaluation criteria)

[0161] ○: The arithmetic mean of the tensile strength retention rate of the three chemicals is above 85%.

[0162] ×: The arithmetic mean of the tensile strength retention rates of the three chemicals is less than 85%.

[0163] <Heat resistance>

[0164] Cut out test pieces in the dumbbell shape specified by No. 3 of JIS K6301 from the obtained film with a thickness of 1 mm. For the obtained test pieces, in a constant temperature and humidity environment controlled at a temperature of 23 ± 2°C and a humidity of 50% ± 10%, use a STROGRAPH (manufactured by Toyo Seiki Seisaku-sho, Ltd.) to perform stretching under the conditions of a gauge length of 20 mm and a stretching speed of 200 mm / minute, thereby measuring the tensile strength (unit: MPa) and tensile elongation rate (unit: %) before the heat aging test.

[0165] Similarly, cut out test pieces in the dumbbell shape specified by No. 3 of JIS K6301 from the obtained film with a thickness of 1 mm.

[0166] Put the obtained test pieces into a gear oven (forced circulation type air heating aging test machine) (manufactured by Toyo Seiki Seisaku-sho, Ltd.) and perform heat exposure treatment. As the heat exposure treatment, the temperature is set to 200°C, and heat treatment is performed for 192 hours after putting them in. For the test pieces that have undergone heat treatment, perform a tensile test according to the above method to measure the tensile strength and tensile elongation rate after the heat aging test.

[0167] Based on the ratio of the tensile strength after heat treatment to the tensile strength before heat treatment, calculate the change rate (%) of the tensile strength caused by the heat aging test. Based on the ratio of the tensile elongation rate after heat treatment to the tensile elongation rate before heat treatment, calculate the change rate (%) of the tensile elongation rate caused by the heat aging test.

[0168] Based on the calculated change rate of the tensile strength, evaluate the tensile strength and tensile elongation rate before and after the heat aging test of each film respectively based on the following evaluation criteria.

[0169] (Evaluation criteria for the change rate of tensile strength)

[0170] ○: The change rate of the tensile strength before and after the heat aging test is 66% or more

[0171] ×: The change rate of the tensile strength before and after the heat aging test is less than 66%

[0172] (Evaluation criteria for the change rate of tensile elongation rate)

[0173] ○: The change rate of the tensile elongation rate before and after the heat aging test is less than 120%

[0174] ×: The change rate of the tensile elongation rate before and after the heat aging test is 120% or more

[0175] <TOC dissolution amount>

[0176] Measure the TOC (total organic carbon) dissolution amount in accordance with SEMI F57 "Specifications for Polymer Materials and Components Used in Ultra-Pure Water and Chemical Solution Supply Systems".

[0177] The sample (the solid composition obtained in the examples) and the PFA container were pre-washed with ultrapure water according to SEMI F40.

[0178] Add 30g of the pre-cleaned sample to the pre-cleaned PFA container, pour in 100mL of ultrapure water to completely immerse it, and carry out leaching at 85℃±3℃ for 7 days under sealed conditions.

[0179] The concentration of each component in the dissolution solution was determined using TOC-L CPH (manufactured by Shimadzu Corporation), and the amount of dissolution relative to the surface area was calculated.

[0180] Moisture content

[0181] Moisture content is determined according to the following steps.

[0182] The moisture content was determined using an infrared moisture meter “FD610” (manufactured by Kett Scientific Research Institute Co., Ltd.) at a drying temperature of 140°C, a time-still mode of 10 minutes, and a sample mass (the solid composition obtained in the examples) of 100g, based on the mass reduction rate before and after the test.

[0183] [Evaluation Experiment]

[0184] <Manufacturing of Coating Test Pieces>

[0185] A 50mm wide, 150mm long, and 2mm thick SUS304 stainless steel sheet was fired at 400°C for 1 hour. Its surface was then sandblasted with alumina particles (Pacific RANDUM Co., Ltd.'s "White Electrolytic Alumina 50A" (trade name)). The sandblasting powder was removed with an air gun to obtain a substrate. The solid composition obtained in the example was pulverized to an average particle size of 80–120 μm and electrostatically coated onto the substrate. The substrate was then fired at 275°C for 15 minutes in an oven. The coating and firing processes were each performed four times to obtain a coated article with a powder film layer approximately 250 μm thick on the substrate.

[0186] <Hot Water Resistance Test (PCT Peel Test)>

[0187] Horizontal parallel cuts were made at 10 mm intervals on the coating film formed on the coating test piece using a cutting knife. At one end of the coating test piece where there was no primer layer, the outermost and topcoat layers were peeled off from the substrate to create a clamp. After treating the clamp at 130°C for 24 hours in an autoclave (high-temperature steam pressure cooker), the clamp was fixed to the chuck of a tensile testing machine, and the 90-degree peel strength (unit: N / cm) was measured at a tensile speed of 50 mm / min.

[0188] Based on this value, the bond strength is evaluated according to the following criteria.

[0189] (Adhesive strength evaluation criteria)

[0190] ○: Above 1.5 N / cm

[0191] ×: Less than 1.5 N / cm

[0192] [Example 1]

[0193] 1167g of a fluorinated organic solvent (AGC Corporation's "ASAHIKLIN (registered trademark) AE-3000", CF3CH2OCF2CF2H), 10.7g of CH2=CH(CF2)4F (PFBE), and 3.6g of methanol were added to a pre-degassed 1.2L polymerization tank equipped with a stirrer. The solution in the polymerization tank was heated to 72°C (polymerization temperature), and then 180g of a TFE / ethylene mixture with a molar ratio of 88 / 12 was added. The pressure in the polymerization tank was then increased to 1.5MPa (gauge pressure).

[0194] At the start, 9.4 mL of a polymerization initiator solution obtained by dissolving tert-butyl peroxypentanoate at a concentration of 1% by mass in AE-3000 was added to initiate polymerization. Additionally, a mixed gas of TFE / ethylene (54 / 46 molar ratio) was continuously added to maintain the pressure in the polymerization tank at 1.5 MPa (gauge pressure). Furthermore, PFBE was continuously added at an amount equivalent to 3 mol% of the total molar amount of TFE and ethylene added during polymerization.

[0195] The polymerization was terminated when the amount of TFE / ethylene introduced reached 110g, yielding copolymer 1 of Example 1.

[0196] The composition of copolymer 1 is TFE unit / E unit / PFBE unit (molar ratio) = 53.4 / 43.6 / 3.0. Here, "PFBE unit" refers to the CH2=CH(CF2)4F-based units in each copolymer. Furthermore, copolymer 1 has an MFR of 34 g / 10 min and a melting point of 242 °C.

[0197] Pure water was added to the obtained copolymer 1, and the mixture was heated while stirring to remove the solvent. Next, water was removed from the mixture of pure water and copolymer 1, and the mixture was dried at a temperature above 100°C for 3.7 hours to obtain solid composition 1. The TOC leaching amount of the dried solid composition 1 was 7200 μg / cm³. 2 The moisture content is 0.05% by mass.

[0198] [Example 2]

[0199] The amount of PFBE initially added to the polymerization tank was changed to 6.9 g, the amount of methanol was changed to 6.0 g, the amount of polymerization initiator solution initially added was changed to 5.9 mL, and the amount of PFBE continuously added during polymerization was changed to 1.9 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 2 of Example 2.

[0200] The composition of copolymer 2 is TFE unit / E unit / PFBE unit (molar ratio) = 53.8 / 44.3 / 1.9. Furthermore, copolymer 2 has an MFR of 35 g / 10 min and a melting point of 252 °C.

[0201] In addition, except that the mixture was dried at a temperature above 100°C for 3.0 hours, the drying process was carried out in the same manner as in Example 1, yielding solid composition 2. The TOC leaching amount of the dried solid composition was 9100 μg / cm³. 2 The moisture content is 0.08% by mass.

[0202] [Example 3]

[0203] The amount of PFBE initially added to the polymerization tank was changed to 10.1 g, the amount of methanol was changed to 4.1 g, the amount of polymerization initiator solution initially added was changed to 8.8 mL, and the amount of PFBE continuously added during polymerization was changed to 2.8 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 3 of Example 3.

[0204] The composition of copolymer 3 is TFE units / E units / PFBE units (molar ratio) = 53.5 / 43.7 / 2.8. Furthermore, copolymer 3 has an MFR of 36 g / 10 min and a melting point of 244 °C.

[0205] In addition, except that the mixture was kept at a temperature above 100°C for 2.4 hours for drying, it was dried in the same manner as in Example 1 to obtain solid composition 3. The TOC leaching amount of the dried solid composition was 11800 μg / cm³. 2 The moisture content is 0.12% by mass.

[0206] [Example 4]

[0207] The amount of PFBE initially added to the polymerization tank was changed to 8.1 g, the amount of methanol was changed to 5.4 g, the amount of polymerization initiator solution initially added was changed to 6.9 mL, and the amount of PFBE continuously added during polymerization was changed to 2.2 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 4 of Example 4.

[0208] The composition of copolymer 4 is TFE unit / E unit / PFBE unit (molar ratio) = 53.8 / 44.0 / 2.2. Furthermore, copolymer 4 has an MFR of 37 g / 10 min and a melting point of 250 °C.

[0209] In addition, except for maintaining the temperature above 100°C for 3.4 hours for drying, the same drying process as in Example 1 was performed to obtain solid composition 4. The TOC leaching amount of the dried solid composition was 7700 μg / cm³. 2 The moisture content is 0.06% by mass.

[0210] [Example 5]

[0211] The amount of PFBE initially added to the polymerization tank was changed to 9.2 g, the amount of methanol was changed to 4.9 g, the amount of polymerization initiator solution initially added was changed to 7.8 mL, and the amount of PFBE continuously added during polymerization was changed to 2.5 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 5 of Example 5.

[0212] The composition of copolymer 5 is TFE units / E units / PFBE units (molar ratio) = 53.6 / 43.9 / 2.5. Furthermore, copolymer 5 has an MFR of 40 g / 10 min and a melting point of 247 °C.

[0213] In addition, except that the mixture was kept at a temperature above 100°C for 2.8 hours for drying, it was dried in the same manner as in Example 1 to obtain solid composition 5. The TOC leaching amount of the dried solid composition was 9800 μg / cm³. 2 The moisture content is 0.09% by mass.

[0214] [Example 6]

[0215] The amount of PFBE initially added to the polymerization tank was changed to 7.3 g, the amount of methanol was changed to 6.1 g, the amount of polymerization initiator solution initially added was changed to 6.3 mL, and the amount of PFBE continuously added during polymerization was changed to 2.0 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 6 of Example 6.

[0216] The composition of copolymer 6 is TFE units / E units / PFBE units (molar ratio) = 53.7 / 44.3 / 2.0. Furthermore, copolymer 6 has an MFR of 41 g / 10 min and a melting point of 251 °C.

[0217] In addition, except for maintaining the temperature above 100°C for 2.0 hours for drying, the same drying process as in Example 1 was performed to obtain solid composition 6. The TOC leaching amount of the dried solid composition was 14600 μg / cm³.2 The moisture content is 0.16% by mass.

[0218] [Example 7]

[0219] The amount of PFBE initially added to the polymerization tank was changed to 10.4 g, the amount of methanol was changed to 4.2 g, the amount of polymerization initiator solution initially added was changed to 9.1 mL, and the amount of PFBE continuously added during polymerization was changed to 2.9 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 7 of Example 7.

[0220] The composition of copolymer 7 is TFE units / E units / PFBE units (molar ratio) = 53.3 / 43.8 / 2.9. Furthermore, copolymer 7 has an MFR of 42 g / 10 min and a melting point of 243 °C.

[0221] In addition, except that the material was kept at a temperature above 100°C for 2.5 hours for drying, it was dried in the same manner as in Example 1 to obtain solid composition 7. The TOC leaching amount of the dried solid composition was 11000 μg / cm³. 2 The moisture content is 0.11% by mass.

[0222] [Example 8]

[0223] The amount of PFBE initially added to the polymerization tank was changed to 8.5 g, the amount of methanol was changed to 5.5 g, the amount of polymerization initiator solution initially added was changed to 7.2 mL, and the amount of PFBE continuously added during polymerization was changed to 2.3 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 8 of Example 8.

[0224] The composition of copolymer 8 is TFE units / E units / PFBE units (molar ratio) = 53.5 / 44.2 / 2.3. Furthermore, copolymer 8 has an MFR of 45 g / 10 min and a melting point of 249 °C.

[0225] In addition, except for maintaining the temperature above 100°C for 2.0 hours for drying, the same drying process as in Example 1 was performed to obtain solid composition 8. The TOC leaching amount of the dried solid composition was 13900 μg / cm³. 2 The moisture content is 0.15% by mass.

[0226] [Example 9]

[0227] The amount of PFBE initially added to the polymerization tank was changed to 10.4 g, the amount of methanol was changed to 4.6 g, the amount of polymerization initiator solution initially added was changed to 9.1 mL, and the amount of PFBE continuously added during polymerization was changed to 2.9 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 9 of Example 9.

[0228] The composition of copolymer 9 is TFE units / E units / PFBE units (molar ratio) = 53.4 / 43.7 / 2.9. Furthermore, copolymer 9 has an MFR of 50 g / 10 min and a melting point of 243 °C.

[0229] In addition, except that the mixture was kept at a temperature above 100°C for 3.2 hours for drying, it was dried in the same manner as in Example 1 to obtain solid composition 9. The TOC leaching amount of the dried solid composition was 8400 μg / cm³. 2 The moisture content is 0.07% by mass.

[0230] [Example 10]

[0231] The amount of PFBE initially added to the polymerization tank was changed to 6.9 g, the amount of methanol was changed to 6.5 g, the amount of polymerization initiator solution initially added was changed to 5.9 mL, and the amount of PFBE continuously added during polymerization was changed to 1.9 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 10 of Example 10.

[0232] The composition of copolymer 10 is TFE units / E units / PFBE units (molar ratio) = 54.0 / 44.1 / 1.9. Furthermore, copolymer 10 has an MFR of 46 g / 10 min and a melting point of 252 °C.

[0233] In addition, except that the mixture was kept at a temperature above 100°C for 2.8 hours for drying, it was dried in the same manner as in Example 1 to obtain solid composition 10. The TOC leaching amount of the dried solid composition was 9790 μg / cm³. 2 The moisture content is 0.09% by mass.

[0234] [Example 11]

[0235] 1167g of a fluorinated organic solvent (AGC Corporation's "ASAHIKLIN (registered trademark) AE-3000", CF3CH2OCF2CF2H), 110.1g of CF2=CFO(CF2)2F (PPVE), and 7.8g of methanol were added to a pre-degassed 1.2L polymerization tank equipped with a stirrer. The solution in the polymerization tank was heated to 66°C (polymerization temperature), and TFE / ethylene was further added at a molar ratio of 76 / 24 until the pressure in the polymerization tank reached 1.5MPa [gauge pressure].

[0236] At the start, 10.0 mL of a polymerization initiator solution obtained by dissolving tert-butyl peroxypentanoate at a concentration of 1% by mass in AE-3000 was added to initiate polymerization. Additionally, a mixed gas of TFE / ethylene (54 / 46 molar ratio) was continuously added to maintain the pressure in the polymerization tank at 1.5 MPa (gauge pressure). Furthermore, PPVE was continuously added at an amount equivalent to 2.7 mol% of the total molar amount of TFE and ethylene added during polymerization.

[0237] The polymerization was terminated when the amount of TFE / ethylene introduced reached 110g, yielding copolymer 11 of Example 11.

[0238] The composition of copolymer 11 is TFE units / E units / PPVE units (molar ratio) = 53.0 / 44.3 / 2.7. Here, "PPVE units" refers to the units in each copolymer based on CF2=CFO(CF2)2F. Furthermore, copolymer 11 has an MFR of 35 g / 10 min and a melting point of 253 °C.

[0239] Pure water was added to the obtained copolymer 11, and the mixture was heated in the same manner as in Example 1 while stirring to remove the solvent. Next, water was removed from the mixture of pure water and copolymer 11, and the mixture was dried at a drying temperature of 100°C or higher for 3.0 hours. The TOC of the dried solid composition 11 was 9100 μg / cm³. 2 The moisture content is 0.08% by mass.

[0240] [Example 12]

[0241] The amount of PPVE initially added to the polymerization tank was changed to 113.8 g, the amount of methanol was changed to 8.1 g, the amount of polymerization initiator solution initially added was changed to 11.0 mL, and the amount of PPVE continuously added during polymerization was changed to 2.9 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 11 was followed to obtain copolymer 12 of Example 12.

[0242] The composition of copolymer 12 is TFE units / E units / PFBE units (molar ratio) = 52.8 / 44.3 / 2.9. Furthermore, copolymer 12 has an MFR of 40 g / 10 min and a melting point of 251 °C.

[0243] In addition, except for maintaining the temperature above 100°C for 3.7 hours for drying, the drying process was carried out in the same manner as in Example 11 to obtain solid composition 12. The TOC leaching amount of the dried solid composition was 7040 μg / cm³. 2 The moisture content is 0.05% by mass.

[0244] [Example 13]

[0245] The amount of PFBE initially added to the polymerization tank was changed to 11.5 g, the amount of methanol was changed to 3.6 g, the amount of polymerization initiator solution initially added was changed to 10.3 mL, and the amount of PFBE continuously added during polymerization was changed to 3.3 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 13 of Example 13.

[0246] The composition of copolymer 13 is TFE units / E units / PFBE units (molar ratio) = 53.0 / 43.7 / 3.3. Furthermore, copolymer 13 has an MFR of 41 g / 10 min and a melting point of 240 °C.

[0247] In addition, except that the mixture was dried at a temperature above 100°C for 4.0 hours, it was dried in the same manner as in Example 1 to obtain solid composition 13. The TOC leaching amount of the dried solid composition was 6200 μg / cm³. 2 The moisture content is 0.04% by mass.

[0248] [Example 14]

[0249] The amount of PFBE initially added to the polymerization tank was changed to 8.8 g, the amount of methanol was changed to 4.6 g, the amount of polymerization initiator solution initially added was changed to 7.5 mL, and the amount of PFBE continuously added during polymerization was changed to 2.4 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 14 of Example 14.

[0250] The composition of copolymer 14 is TFE units / E units / PFBE units (molar ratio) = 53.4 / 44.2 / 2.4. Furthermore, copolymer 14 has an MFR of 31 g / 10 min and a melting point of 248 °C.

[0251] In addition, except for maintaining the temperature above 100°C for 3.0 hours for drying, the same drying process as in Example 1 was performed to obtain solid composition 14. The TOC leaching amount of the dried solid composition was 9100 μg / cm³. 2 The moisture content is 0.08% by mass.

[0252] [Example 15]

[0253] The amount of PFBE initially added to the polymerization tank was changed to 6.0 g, the amount of methanol was changed to 7.0 g, the amount of polymerization initiator solution initially added was changed to 5.3 mL, and the amount of PFBE continuously added during polymerization was changed to 1.7 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 15 of Example 15.

[0254] The composition of copolymer 15 is TFE units / E units / PFBE units (molar ratio) = 53.5 / 44.8 / 1.7. Furthermore, copolymer 15 has an MFR of 43 g / 10 min and a melting point of 254 °C.

[0255] In addition, except that the mixture was kept at a temperature above 100°C for 3.2 hours for drying, it was dried in the same manner as in Example 1 to obtain solid composition 15. The TOC leaching amount of the dried solid composition was 8400 μg / cm³. 2 The moisture content is 0.07% by mass.

[0256] [Example 16]

[0257] The amount of PFBE initially added to the polymerization tank was changed to 7.3 g, the amount of methanol was changed to 6.9 g, the amount of polymerization initiator solution initially added was changed to 7.1 mL, and the amount of PFBE continuously added during polymerization was changed to 2.0 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 16 of Example 16.

[0258] The composition of copolymer 16 is TFE units / E units / PFBE units (molar ratio) = 53.6 / 44.4 / 2.0. Furthermore, copolymer 15 has an MFR of 64 g / 10 min and a melting point of 251 °C.

[0259] In addition, except that the material was dried at a temperature above 100°C for 2.0 hours, the drying process was carried out in the same manner as in Example 1, yielding solid composition 16. The TOC leaching amount of the dried solid composition was 14000 μg / cm³. 2 The moisture content is 0.15% by mass.

[0260] [Example 17]

[0261] The amount of PFBE initially added to the polymerization tank was changed to 7.3 g, the amount of methanol was changed to 6.1 g, the amount of polymerization initiator solution initially added was changed to 6.3 mL, and the amount of PFBE continuously added during polymerization was changed to 2.0 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 17 of Example 17.

[0262] The composition of copolymer 17 is TFE units / E units / PFBE units (molar ratio) = 53.8 / 44.2 / 2.0. Furthermore, copolymer 17 has an MFR of 41 g / 10 min and a melting point of 251 °C.

[0263] In addition, except that the mixture was kept at a temperature above 100°C for 0.5 hours for drying, it was dried in the same manner as in Example 1 to obtain solid composition 17. The TOC leaching amount of the dried solid composition was 65000 μg / cm³. 2 The moisture content is 0.9% by mass.

[0264] [Example 18]

[0265] The amount of PFBE initially added to the polymerization tank was changed to 7.3 g, the amount of methanol was changed to 6.0 g, the amount of polymerization initiator solution initially added was changed to 6.3 mL, and the amount of PFBE continuously added during polymerization was changed to 2.0 mol% of the total molar amount of TFE and ethylene. Otherwise, the same procedure as in Example 1 was followed to obtain copolymer 18 of Example 18.

[0266] The composition of copolymer 18 is TFE units / E units / PFBE units (molar ratio) = 53.7 / 44.3 / 2.0. Furthermore, copolymer 18 has an MFR of 40 g / 10 min and a melting point of 251 °C.

[0267] In addition, except for maintaining the temperature above 100°C for 6.8 hours for drying, the same drying process as in Example 1 was performed to obtain solid composition 18. The TOC leaching amount of the dried solid composition was 975 μg / cm³. 2 The moisture content is 0.01% by mass.

[0268] The composition of the copolymers in each example, as well as the determination and evaluation results of the copolymers, are shown in Table 1.

[0269] In the table, the “TFE unit (mol%)” column indicates the TFE unit content (in mol%) relative to all units contained in this copolymer.

[0270] The “E-unit (mol%)” column indicates the E-unit content (in mol%) relative to all units contained in this copolymer.

[0271] The “TFE / (TFE+E)(mol%)” column indicates the TFE cell content (in mol%) relative to the total content of TFE cells and E cells.

[0272] The “A Unit (mol%)” column indicates the A unit content (in mol%) relative to all units contained in this copolymer.

[0273] [Table 1]

[0274]

[0275] [Table 2]

[0276]

[0277] As shown in Table 1, it can be confirmed that by using a copolymer containing TFE units, E units, and A units, where the total content of TFE units and E units is 80.0 to 98.1 mol% relative to all units contained in the copolymer, the content of TFE units is 49.0 mol% or more and less than 56.0 mol% relative to the total content of TFE units and E units, and the content of A units is 1.9 mol% or more and less than 3.2 mol% relative to all units contained in the copolymer, molded articles with excellent tensile strength after chemical resistance tests, tensile strength after heat aging tests, and tensile elongation after heat aging tests can be formed (Examples 1 to 12).

[0278] The determination and evaluation results of the solid compositions for each example are shown in Table 2.

[0279] In the table, the “TFE unit (mol%)” column indicates the TFE unit content (in mol%) relative to all units contained in this copolymer.

[0280] The “E-unit (mol%)” column indicates the E-unit content (in mol%) relative to all units contained in this copolymer.

[0281] The “TFE / (TFE+E)(mol%)” column indicates the TFE cell content (in mol%) relative to the total content of TFE cells and E cells.

[0282] The “A Unit (mol%)” column indicates the A unit content (in mol%) relative to all units contained in this copolymer.

[0283] [Table 3]

[0284]

[0285] [Table 4]

[0286]

[0287] Furthermore, the entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2023-099581, filed on June 16, 2023, are incorporated herein as a disclosure of the present invention.

Claims

1. A copolymer comprising units based on tetrafluoroethylene, units based on ethylene, and any or both of units based on a compound represented by formula (1) and units based on a compound represented by formula (2), wherein, The total content of the tetrafluoroethylene-based units and the ethylene-based units is 80.0–98.1 mol% relative to all units contained in the copolymer. The content of the tetrafluoroethylene-based unit relative to the total content of the tetrafluoroethylene-based unit and the ethylene-based unit is 49.0 mol% or more and less than 56.0 mol%. The content of units based on the compound represented by formula (1) or units based on the compound represented by formula (2) is more than 1.9 mol% and less than 3.2 mol% relative to all units contained in the copolymer. The copolymer, as determined by ASTM D3159 at a temperature of 297°C and a load of 49N, has a melt flow rate of 33–50 g / 10 minutes. CZ2=CX(CF2) m Y formula (1) CF2=CF-O-(CF2) n Formula (2) In equation (1), X, Y and Z each independently represent a hydrogen atom or a fluorine atom, and m represents an integer from 2 to 6; In equation (2), n represents an integer from 1 to 6.

2. The copolymer of claim 1, comprising the tetrafluoroethylene-based unit, the ethylene-based unit, and the unit based on the compound represented by formula (1), wherein, The content of the unit based on the compound represented by formula (1) is more than 1.9 mol% and less than 3.2 mol% relative to all units contained in the copolymer.

3. A composition comprising the copolymer of claim 1 or 2.

4. A solid composition comprising the copolymer of claim 1 or 2, wherein the total organic carbon leaching (TOC) is 1000–63000 μg / cm³. 2 .

5. A solid composition comprising the copolymer of claim 1 or 2, having a water content of 0.02 to 0.8% by mass.

6. A molded article obtained by molding the copolymer of claim 1 or 2.

7. A molded article obtained by molding the composition of claim 3.

8. A molded article obtained by molding the solid composition of claim 4.

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