Polymer composition, binder for electrochemical devices, electrode mixture, electrode, and secondary battery

Abstract

Polymer compositions for adhesives used in electrochemical devices are provided, which can improve the coulombic efficiency of electrochemical devices. One polymer composition, which is a polymer composition for adhesives used in electrochemical devices, comprises a fibrillable polymer, a thermoplastic polymer, and at least one compound selected from the group consisting of compounds represented by general formula (1) and compounds represented by general formula (2). General formula (1): (H-(CF2)) m‑1 -COO) p M 1 (In the formula, m is 4 to 20, M) 1 For H, metal atoms, NR 5 4(R 5 They can be the same or different (e.g., H or organic groups with 1 to 10 carbon atoms), p is 1 or 2). General formula (2): (H-(CF2) n -SO3) q M 2 (In the formula, n is 4 to 20, M) 2 For H, metal atoms, NR 5 4(R 5 (Same as above), etc., where q is 1 or 2).

Description

Technical Field

[0001] This disclosure relates to polymer compositions, binders for electrochemical devices, electrode compounds, electrodes, and secondary batteries. Background Technology

[0002] Lithium-ion batteries and other rechargeable batteries are used in small and portable electrical and electronic devices such as laptops, mobile phones, smartphones, tablets, and ultrabooks due to their high voltage, high energy density, low self-discharge, low memory effect, and ability to achieve ultra-lightweight designs. They are also being practically applied as power sources for automotive applications, such as driving power supplies for vehicles or large stationary power supplies. Further improvements in energy density and battery characteristics are needed for rechargeable batteries.

[0003] Patent document 1 describes an energy storage device in which at least one of the cathode and anode comprises a polytetrafluoroethylene mixed binder material.

[0004] Patent documents 2-6 describe the use of polytetrafluoroethylene as a binder for batteries.

[0005] Patent documents 7-9 describe composite adhesives made of polytetrafluoroethylene and polyvinylidene fluoride, etc.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Publication No. 2017-517862

[0009] Patent Document 2: International Publication No. 2021 / 181887

[0010] Patent Document 3: International Publication No. 2021 / 181888

[0011] Patent Document 4: International Publication No. 2021 / 192541

[0012] Patent Document 5: International Publication No. 2022 / 138942

[0013] Patent Document 6: International Publication No. 2022 / 138939

[0014] Patent Document 7: International Publication No. 2023 / 286787

[0015] Patent Document 8: International Publication No. 2022 / 234227

[0016] Patent Document 9: International Publication No. 2023 / 094623 Summary of the Invention

[0017] The problem that the invention aims to solve

[0018] The purpose of this disclosure is to provide polymer compositions for binders of electrochemical devices that can improve the coulombic efficiency of electrochemical devices, as well as binders, electrode mixtures, electrodes and secondary batteries for electrochemical devices using the same.

[0019] Methods for solving problems

[0020] This disclosure (1) is a polymer composition for use as an adhesive in electrochemical devices, comprising a fibrillated polymer, a thermoplastic polymer, and at least one compound selected from the group consisting of compounds represented by general formula (1) and general formula (2).

[0021] General formula (1): (H-(CF2)) m-1 -COO) p M 1

[0022] (In the formula, m ranges from 4 to 20. M) 1 For H, metal atoms, NR 5 4(R 5 They can be the same or different (either H or an organic group with 1 to 10 carbon atoms), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. p is 1 or 2).

[0023] General formula (2): (H-(CF2)) n -SO3) q M 2

[0024] (In the formula, n is 4 to 20. M) 2 For H, metal atoms, NR 5 4(R 5 (Same as above), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. q is 1 or 2).

[0025] This disclosure (2) is a polymer composition for use as an adhesive in electrochemical devices, comprising a fibrillated polymer and a thermoplastic polymer, wherein the fibrillated polymer has a thermal instability index (TII) of 10 or higher.

[0026] This disclosure (3) is a polymer composition as described in disclosure (1) or (2), wherein the fibrillable polymer is at least one selected from the group consisting of homopolymers of tetrafluoroethylene and modified polytetrafluoroethylene consisting only of tetrafluoroethylene units and hexafluoropropylene-based polymer units.

[0027] This disclosure (4) is a polymer composition as described in any one of (1) to (3) of this disclosure, wherein the content of the fibrillating polymer is more than 50% by mass and less than 97% by mass relative to the polymer composition.

[0028] This disclosure (5) refers to the polymer composition as described in any one of (1) to (4) of this disclosure, wherein the thermoplastic polymer is at least one vinylidene fluoride-based polymer selected from the group consisting of polyvinylidene fluoride and vinylidene fluoride / tetrafluoroethylene copolymers.

[0029] The polymer composition of any one of (1) to (5) of this disclosure (6) is in the form of a powder.

[0030] This disclosure (7) comprises the polymer composition as described in any one of disclosures (1) to (6), which is used as an adhesive for lithium-ion secondary batteries.

[0031] This disclosure (8) is an adhesive for electrochemical devices, which is an adhesive for electrochemical devices consisting substantially only of a polymer composition, wherein the polymer composition comprises a fibrillated polymer, a thermoplastic polymer, and at least one compound selected from the group consisting of a compound represented by the following general formula (1) and a compound represented by the following general formula (2).

[0032] General formula (1): (H-(CF2)) m-1 -COO) p M 1

[0033] (In the formula, m ranges from 4 to 20. M) 1 For H, metal atoms, NR 5 4(R 5 They can be the same or different (either H or an organic group with 1 to 10 carbon atoms), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. p is 1 or 2).

[0034] General formula (2): (H-(CF2)) n -SO3) q M 2

[0035] (In the formula, n is 4 to 20. M) 2 For H, metal atoms, NR 5 4(R 5 (Same as above), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. q is 1 or 2).

[0036] This disclosure (9) is an adhesive for electrochemical devices, which is an adhesive for electrochemical devices consisting substantially only of a polymer composition, wherein the polymer composition comprises a fibrillated polymer and a thermoplastic polymer, and the fibrillated polymer has a thermal instability index (TII) of 10 or more.

[0037] This disclosure (10) is an adhesive for electrochemical devices as described in disclosure (8) or (9), wherein the polymer composition has endothermic peaks in regions below and above 330°C.

[0038] This disclosure (11) is an adhesive for electrochemical devices as described in any one of disclosures (8) to (10), wherein the endothermic peak temperature of the fibrillable polymer exceeds 330°C.

[0039] This disclosure (12) is an adhesive for electrochemical devices as described in any one of disclosures (8) to (11), wherein the fibrillating polymer is a tetrafluoroethylene-based polymer.

[0040] This disclosure (13) includes an adhesive for electrochemical devices as described in any one of disclosures (8) to (12), wherein the fibrillable polymer is at least one selected from the group consisting of homopolymers of tetrafluoroethylene and modified polytetrafluoroethylene consisting only of tetrafluoroethylene units and hexafluoropropylene-based polymer units.

[0041] This disclosure (14) is an adhesive for electrochemical devices as described in any one of (8), (10) to (13) of this disclosure, wherein the thermal instability index (TII) of the fibrillable polymer is 10 or more.

[0042] This disclosure (15) is an adhesive for electrochemical devices as described in any one of disclosures (8) to (14), wherein the amount of the thermoplastic polymer is less than 50% by mass relative to the polymer composition.

[0043] This disclosure (16) is an adhesive for electrochemical devices as described in any one of disclosures (8) to (15), wherein the content of the fibrillable polymer is more than 50% by mass and less than 97% by mass relative to the polymer composition.

[0044] This disclosure (17) is an adhesive for electrochemical devices as described in any one of disclosures (8) to (16), wherein the polymer composition has a 0.1% mass reduction temperature of 340°C or higher.

[0045] This disclosure (18) is an adhesive for electrochemical devices as described in any one of disclosures (8) to (17), wherein the polymer composition has a 1.0% mass reduction temperature of 370°C or higher.

[0046] This disclosure (19) is an adhesive for electrochemical devices as described in any one of disclosures (8) to (16), wherein the thermoplastic polymer is a vinylidene fluoride-based polymer.

[0047] This disclosure (20) is an adhesive for electrochemical devices as described in this disclosure (19), wherein the vinylidene fluoride polymer is a fluorinated elastomer.

[0048] This disclosure (21) is an adhesive for electrochemical devices as described in this disclosure (20), wherein the fluorinated elastomer comprises vinylidene fluoride units and other monomer units capable of copolymerizing with vinylidene fluoride.

[0049] This disclosure (22) is an adhesive for electrochemical devices as described in disclosure (20) or (21), wherein the fluorinated elastomer is at least one selected from the group consisting of vinylidene fluoride / hexafluoropropylene copolymer, vinylidene fluoride / 2,3,3,3-tetrafluoropropylene copolymer and vinylidene fluoride / tetrafluoroethylene / hexafluoropropylene copolymer.

[0050] This disclosure (23) is an adhesive for electrochemical devices as described in any one of disclosures (8) to (16), wherein the polymer composition has an endothermic peak in at least the region of 130 to 200°C.

[0051] This disclosure (24) includes an adhesive for electrochemical devices as described in any one of disclosures (8) to (16), wherein the thermoplastic polymer is at least one vinylidene fluoride-based polymer selected from the group consisting of polyvinylidene fluoride and vinylidene fluoride / tetrafluoroethylene copolymers.

[0052] This disclosure (25) is an adhesive for electrochemical devices as described in this disclosure (24), wherein the average particle size of the vinylidene fluoride polymer is less than 10 μm and it does not contain fluorinated surfactants.

[0053] This disclosure (26) is an adhesive for electrochemical devices as described in any one of disclosures (8) to (25), wherein the polymer composition has an average aspect ratio of 2.5 or less in powder form.

[0054] This disclosure (27) is an adhesive for electrochemical devices as described in any one of disclosures (8) to (26), wherein the powder of the fibrillable polymer is not fibrillated.

[0055] The binder for electrochemical devices as described in any one of (8) to (27) of this disclosure (28) is in the form of a powder.

[0056] This disclosure (29) refers to the binder for electrochemical devices as described in any one of disclosures (8) to (28), which is a binder for lithium-ion secondary batteries.

[0057] This disclosure (30) is an electrode compound comprising any one of the polymer compositions of this disclosure (1) to (7) or any one of the binders and electrode active substances for electrochemical devices of this disclosure (8) to (29).

[0058] The electrode mixture described in this disclosure (31) as described in this disclosure (30) is in the form of a tablet.

[0059] This disclosure (32) is an electrode comprising the polymer composition of any one of the present disclosures (1) to (7) or the binder for electrochemical devices, electrode active material and current collector of any one of the present disclosures (8) to (29).

[0060] This disclosure (33) is a secondary battery having the electrodes described in this disclosure (32).

[0061] Invention Effects

[0062] According to this disclosure, it is possible to provide polymer compositions for binders of electrochemical devices that can improve the coulombic efficiency of electrochemical devices, as well as binders, electrode mixtures, electrodes and secondary batteries for electrochemical devices using the same. Detailed Implementation

[0063] In this disclosure, "organic group" means a group containing one or more carbon atoms, or a group formed by removing one hydrogen atom from an organic compound.

[0064] As the aforementioned organic group, an alkyl group with or without one or more substituents is preferred.

[0065] The following details this disclosure.

[0066] This disclosure provides a polymer composition (hereinafter also referred to as the polymer composition (1) of this disclosure) that is a polymer composition for use as an adhesive in electrochemical devices, comprising a fibrillated polymer, a thermoplastic polymer, and at least one compound selected from the group consisting of a compound represented by the following general formula (1) and a compound represented by the following general formula (2).

[0067] General formula (1): (H-(CF2)) m-1 -COO) p M 1

[0068] (In the formula, m ranges from 4 to 20. M) 1 For H, metal atoms, NR 5 4(R 5They can be the same or different (either H or an organic group with 1 to 10 carbon atoms), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. p is 1 or 2).

[0069] General formula (2): (H-(CF2)) n -SO3) q M 2

[0070] (In the formula, n is 4 to 20. M) 2 For H, metal atoms, NR 5 4(R 5 (Same as above), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. q is 1 or 2).

[0071] This disclosure also provides a polymer composition (hereinafter also referred to as the polymer composition (2) of this disclosure), which is a polymer composition for use as an adhesive in electrochemical devices, comprising a fibrillated polymer and a thermoplastic polymer, wherein the thermal instability index (TII) of the fibrillated polymer is 10 or higher.

[0072] In this specification, unless otherwise specified, the polymer compositions (1) to (2) disclosed herein are collectively referred to as “polymer compositions disclosed herein”.

[0073] The polymer composition disclosed herein, by having the above-described structure, can improve the coulombic efficiency of electrochemical devices. Furthermore, even with small amounts, it is possible to produce a composite sheet. Additionally, since a composite sheet with excellent adhesion to substrates such as metal foil can be obtained, the composite sheet can be bonded to the substrate even without increasing the density of the composite layer (even without compaction), enabling processing under a wider range of molding conditions.

[0074] When the polymer composition of this disclosure is made into powder form, its flowability can also be improved.

[0075] Furthermore, the polymer compositions disclosed herein can be used in a dry manner, thus eliminating the need for large amounts of dispersion media such as water or organic solvents. This allows for a wide selection of electrode active materials and solid electrolytes, which is advantageous in the production process. Additionally, it reduces the number of steps and costs associated with using dispersion media.

[0076] Furthermore, the polymer composition disclosed herein exhibits excellent adhesion to active substances and electrolytes, thereby enabling a reduction in the amount used.

[0077] The polymer composition disclosed herein comprises a fibrillating polymer. A fibrillating polymer is a polymer that readily fibrillates when shear stress is applied. The higher the molecular weight, the easier it is to fibrillate. The molecular weight of the aforementioned fibrillating polymer is, for example, 500,000 or more, preferably 1 million or more, more preferably 5 million or more, further preferably 10 million or more, even more preferably 20 million or more, and can be less than 200 million.

[0078] The molecular weight mentioned above can be the number average molecular weight (Mn), which can be calculated using the following formula.

[0079] SSG = -0.0579logMn + 2.6113

[0080] In the formula, SSG is the standard specific gravity of the polymer, which is determined using a sample molded according to ASTM D 4895 89 by the water displacement method according to ASTM D 792.

[0081] From the perspective of being able to form compound tablets with superior strength, the endothermic peak temperature of the above-mentioned fibrillable polymer is preferably above 330°C, more preferably above 333°C, even more preferably above 335°C, even more preferably above 337°C, particularly preferably above 340°C, and preferably below 350°C, more preferably below 346°C.

[0082] Regarding the aforementioned endothermic peak temperatures, for fibrillable polymers that have not been heated to temperatures above 300°C, differential scanning calorimetry (DSC) was performed at a heating rate of 10°C / min, and the temperature corresponding to the minimum point in the obtained heat of fusion curve was recorded. In cases where there are two or more minimum points within a single melting peak, each was used as the endothermic peak temperature.

[0083] In the polymer composition (1) disclosed herein, the thermal instability index (TII) of the fibrillable polymer is preferably 10 or more. In the polymer composition (2) disclosed herein, the TII of the fibrillable polymer is 10 or more.

[0084] Profibrillatory polymers with a TII of 10 or higher are obtained by using hydrocarbon-based surfactants.

[0085] From the perspectives of further improving the coulombic efficiency of electrochemical devices, further reducing the amount added, further improving the adhesion between the compound tablet and the substrate, and further improving the powder flowability, the TII is more preferably 15 or more, more preferably 20 or more, even more preferably 25 or more, even more preferably 30 or more, even more preferably 35 or more, even more preferably 40 or more, and preferably 200 or less, more preferably 100 or less, even more preferably 80 or less, and even more preferably 50 or less.

[0086] The above TII was determined according to ASTM D 4895-89.

[0087] The 0.1% mass reduction temperature of the above-mentioned fibrillable polymer can be below 400°C.

[0088] fibrillable polymers with a 0.1% mass reduction temperature below 400°C are obtained by using hydrocarbon-based surfactants. The aforementioned 0.1% mass reduction temperature is a value determined by the following method.

[0089] Approximately 10 mg of fibrillable polymer that has not been heated to temperatures above 300°C is accurately weighed and placed in a dedicated aluminum pan for TG-DTA (differential thermal-thermogravimetric analysis). The 0.1% mass reduction temperature is defined as follows: the aluminum pan is heated at 10°C / min in atmospheric conditions over a temperature range from 25°C to 600°C; the temperature corresponding to the point where a 0.1% mass reduction occurs is defined as the 0.1% mass reduction temperature.

[0090] The 1.0% mass reduction temperature of the above-mentioned fibrillable polymer can be below 492°C.

[0091] fibrillable polymers with a 1.0% mass reduction temperature below 492°C are obtained by using hydrocarbon-based surfactants. The aforementioned 1.0% mass reduction temperature is a value determined by the following method.

[0092] Approximately 10 mg of fibrillable polymer that has not been heated to temperatures above 300°C is accurately weighed and placed in a dedicated aluminum pan for TG-DTA (differential thermal-thermogravimetric analysis). The 1.0% mass reduction temperature is defined as the temperature at which a 1.0% mass reduction occurs when the aluminum pan is heated at 10°C / min in atmospheric conditions over a temperature range from 25°C to 600°C.

[0093] Examples of fibrillating polymers include tetrafluoroethylene (TFE) polymers, polyethylene, polyester, liquid crystal polymers (LCP), and acrylic resins. TFE polymers, polyethylene, and polyesters are preferred, with TFE polymers being more preferred.

[0094] The aforementioned TFE-based polymers can be homopolymers of TFE or TFE copolymers comprising TFE-based polymerization units (TFE units) and polymerization units based on modified monomers capable of copolymerizing with TFE (modified monomer units).

[0095] The aforementioned TFE-based polymers can be polytetrafluoroethylene (PTFE). The aforementioned PTFE includes homopolymers of TFE and modified PTFE containing more than 99.0% by mass of TFE units and less than 1.0% by mass of modified monomer units.

[0096] From the perspectives of further improving the coulombic efficiency of electrochemical devices, further reducing the amount added, further improving the adhesion between the compound tablet and the substrate, and further improving the flowability of the powder, the above-mentioned TFE-based polymer is preferably PTFE, and more preferably modified PTFE.

[0097] It should be noted that, in this disclosure, the homopolymer of TFE refers to a polymer in which the content of the modified monomer unit relative to the total polymeric unit is less than 0.0001% by mass.

[0098] From the perspectives of further improving the coulombic efficiency of electrochemical devices, further reducing the amount added, further improving the adhesion between the compound tablet and the substrate, and further improving the powder flowability, the content of the modified monomer unit relative to all polymer units is preferably in the range of 0.0001 to 10% by mass. As a lower limit for the content of the modified monomer unit, it is more preferably 0.001% by mass, more preferably 0.010% by mass, even more preferably 0.015% by mass, and particularly preferably 0.020% by mass. As an upper limit for the content of the modified monomer unit, it is preferably 5.0% by mass, more preferably 3.0% by mass, more preferably 1.0% by mass, even more preferably 0.80% by mass, even more preferably 0.60% by mass, even more preferably 0.50% by mass, even more preferably 0.40% by mass, even more preferably 0.30% by mass, and particularly preferably 0.20% by mass.

[0099] In this specification, the modified monomer unit mentioned above refers to a part of the molecular structure of the TFE-based polymer that is derived from the modified monomer.

[0100] The content of each of the above-mentioned polymerization units can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and fluorescence X-ray analysis according to the type of monomer.

[0101] As for the aforementioned modified monomers, there are no particular limitations as long as they can copolymerize with TFE. Examples include perfluoroolefins such as hexafluoropropylene [HFP]; hydrofluoroolefins such as trifluoroethylene and vinylidene fluoride [VdF]; perhaloolefins such as trifluorochloroethylene [CTFE]; perfluorovinyl ethers; perfluoroallyl ethers; (perfluoroalkyl)ethylene; ethylene; and monomers with polar groups. In addition, one or more modified monomers can be used.

[0102] The perfluorovinyl ethers mentioned above are not particularly limited; for example, perfluorounsaturated compounds represented by the following general formula (A) can be cited.

[0103] (where Rf) 1 (This refers to a perfluorinated organic group). In this specification, "perfluorinated organic group" refers to an organic group in which all hydrogen atoms bonded to carbon atoms are replaced by fluorine atoms. The aforementioned perfluorinated organic group may contain ether oxygen.

[0104] Examples of perfluorovinyl ethers include perfluoro(alkylvinyl ether) [PAVE], and preferably Rf of the above general formula (A). 1 The PAVE has 1 to 10 carbon atoms. The preferred number of carbon atoms for the above-mentioned perfluoroalkyl group is 1 to 5.

[0105] Examples of perfluoroalkyl groups in the aforementioned PAVE include perfluoromethyl, perfluoroethyl, perfluoropropyl, perfluorobutyl, perfluoropentyl, and perfluorohexyl.

[0106] As a further example of the aforementioned perfluorovinyl ether, Rf in the above general formula (A) can be cited. 1 Substances with a perfluoro(alkoxyalkyl) group having 4 to 9 carbon atoms; Rf 1 Substances with groups represented by the following formula; [Chemistry 1]

[0107] (In the formula, m represents 0 or an integer from 1 to 4); Rf 1 Substances containing groups represented by the following formulas, [Chemistry 2]

[0108] (In the formula, n represents an integer from 1 to 4).

[0109] There is no particular limitation as to (perfluoroalkyl)ethylene [PFAE], for example, (perfluorobutyl)ethylene [PFBE], (perfluorohexyl)ethylene, etc.

[0110] Examples of perfluoroallyl ethers include, for example, fluorinated monomers represented by general formula (B).

[0111] (where Rf) 2 (Indicates a perfluorinated organic group).

[0112] The above Rf 2Preferred are perfluoroalkyl groups having 1 to 10 carbon atoms or perfluoroalkoxyalkyl groups having 1 to 10 carbon atoms. As the above-mentioned perfluoroallyl ether, it is preferably selected from at least one of the group consisting of CF2=CF-CF2-O-CF3, CF2=CF-CF2-O-C2F5, CF2=CF-CF2-O-C3F7, and CF2=CF-CF2-O-C4F9, more preferably from at least one of the group consisting of CF2=CF-CF2-O-C2F5, CF2=CF-CF2-O-C3F7, and CF2=CF-CF2-O-C4F9, and even more preferably from CF2=CF-CF2-O-CF2CF2CF3.

[0113] The modified monomers are preferably compounds represented by the following general formula (i).

[0114] (where X) 1 ~X 3 Each can be H or F independently. X 4 It can be F, Cl, Rf, or O-Rf. Rf is a perfluorinated organic group.

[0115] As Rf in general formula (i), a perfluoroalkyl group having 1 to 10 carbon atoms is preferred, a perfluoroalkyl group having 1 to 5 carbon atoms is more preferred, and a perfluoroalkyl group having 1 to 4 carbon atoms is even more preferred.

[0116] The monomers with polar groups mentioned above can be either non-fluorinated monomers or fluorinated monomers.

[0117] Examples of non-fluorinated monomers include hydroxyl groups such as hydroxyl ethyl vinyl ether, hydroxyl propyl vinyl ether, hydroxyl butyl vinyl ether, hydroxyisobutyl vinyl ether, and hydroxycyclohexyl vinyl ether; non-fluorinated monomers with carboxyl groups such as acrylic acid, methacrylic acid, itaconic acid, succinic acid, fumaric acid, crotonic acid, maleic acid, citraconic acid, undecenoic acid, and ethynyl dicarboxylic acid; and itaconic anhydride (hereinafter also referred to as "IAH"), citraconic anhydride (hereinafter also referred to as "CAH"), and 5-norbornene-2- Non-fluorinated monomers with anhydride residues, such as 3-dicarboxylic anhydride (hereinafter also referred to as "NAH"), succinic anhydride, fumaric anhydride, and maleic anhydride; non-fluorinated monomers with sulfonate groups, such as vinyl sulfonic acid; non-fluorinated monomers with epoxy groups (glycidyl groups), such as glycidyl vinyl ether and glycidyl allyl ether; non-fluorinated monomers with amino groups, such as aminoalkyl vinyl ether and aminoalkyl allyl ether; non-fluorinated monomers with amide groups, such as (meth)acrylamide and hydroxymethylacrylamide; and non-fluorinated monomers with nitrile groups, such as acrylonitrile and methacrylonitrile.

[0118] Among them, non-fluorinated monomers having carboxyl groups and non-fluorinated monomers having anhydride residues are preferred, non-fluorinated monomers having anhydride residues are more preferred, and cyclic non-fluorinated monomers having anhydride residues are even more preferred.

[0119] The aforementioned monomers with polar groups also preferably include modified monomers (hereinafter referred to as "modified monomer (A)") having functional groups and hydrophilic groups capable of undergoing free radical polymerization.

[0120] Examples of hydrophilic groups in the aforementioned modified monomer (A) include -NH2, -PO3M, -OPO3M, -SO3M, -OSO3M, and -COOM (where M represents H, a metal atom, or NR). 7 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 7 It can be an H or an organic group, which can be the same or different. Any two can bond together to form a ring. As the above-mentioned hydrophilic group, -SO3M or -COOM is preferred. As R 7 H or C are preferred 1-10 Organic groups, more preferably H or C 1-4 The organic groups, preferably H or C, are preferred. 1-4 Alkyl groups.

[0121] Examples of metal atoms that can be classified as monovalent or divalent include alkali metals (Group 1) and alkaline earth metals (Group 2), with Na, K, or Li being preferred.

[0122] As a "functional group capable of undergoing reaction via free radical polymerization" in the aforementioned modified monomer (A), examples include groups with olefinic unsaturated bonds such as vinyl and allyl.

[0123] Groups containing olefinic unsaturated bonds can be represented by the following formula,

[0124] (where X) e X f and X g Each can be independently F, Cl, H, CF3, CF2H, CFH2, or CH3; R is a linking group. Examples of linking groups for R, as described later, can be found... aLinking groups include, preferably, groups with unsaturated bonds such as -CH=CH2, -CF=CH2, -CH=CF2, -CF=CF2, -CH2-CH=CH2, -CF2-CF=CH2, -CF2-CF=CF2, -(C=O)-CH=CH2, -(C=O)-CF=CH2, -(C=O)-CH=CF2, -(C=O)-CF=CF2, -(C=O)-C(CH3)=CH2, -(C=O)-C(CF3)=CH2, -(C=O)-C(CF3)=CF2, -(C=O)-C(CF3)=CF2, -O-CH2-CH=CH2, -O-CF2-CF=CH2, -O-CH2-CH=CF2, and -O-CF2-CF=CF2.

[0125] The modified monomer (A) described above possesses functional groups capable of undergoing free radical polymerization. Therefore, it is hypothesized that when used in polymerization, it reacts with the fluorinated monomer in the early stages of the polymerization reaction to form particles with hydrophilic groups derived from the modified monomer (A) and high stability. Thus, it is believed that the particle number increases when polymerization is carried out in the presence of the modified monomer (A).

[0126] The modified monomer (A) mentioned above can be used alone or in combination of two or more.

[0127] As the modified monomer (A) mentioned above, a compound having unsaturated bonds can be used.

[0128] The modified monomer (A) is preferably at least one selected from the group consisting of compounds represented by the following formulas (4a) to (4e).

[0129]

[0130] (In the formula, n1 represents an integer from 1 to 10, Y) 3 Indicates -SO3M 1 or -COOM 1 M 1 (Indicates H, NH4, or alkali metal).

[0131]

[0132] (In the formula, n2 represents an integer from 1 to 5, Y) 3 Same as the definition above).

[0133]

[0134] (where X) 1 Let F or CF3 represent n3, where n3 represents an integer from 1 to 10, and Y represents n3. 3 Same as the definition above).

[0135]

[0136] (In the formula, n4 represents an integer from 1 to 10, Y) 3 and X 1 Same as the definition above).

[0137]

[0138] (In the formula, each X) 2 Same, indicating F or H. n5 represents 0 or an integer from 1 to 10, Y 3 Same as the definition above).

[0139] Examples of alkali metals mentioned above include Na and K.

[0140] In the above formula (4a), n1 is preferably an integer of 5 or less, more preferably an integer of 2 or less. From the perspective of obtaining moderate water solubility and surface activity, the above Y 3 Preferred -COOM 1 From the perspective of minimizing residue as an impurity and improving the heat resistance of the resulting molded article, M 1 H or NH4 is preferred.

[0141] Examples of perfluorovinylalkyl compounds represented by formula (4a) above include CF2=CFCF2COOM. 1 (where M is in the formula) 1 Same as the definition above).

[0142] In the above formula (4b), from the perspective of emulsifying ability, n2 is preferably an integer of 3 or less; from the perspective of obtaining suitable water solubility and surface activity, Y 3 Preferred -COOM 1 From the perspective of minimizing residue as an impurity and improving the heat resistance of the resulting molded article, M 1 H or NH4 is preferred.

[0143] In the above formula (4c), from the perspective of water solubility, n3 is preferably an integer of 5 or less; from the perspective of obtaining moderate water solubility and surface activity, the above Y... 3 Preferred -COOM 1 From the perspective of good dispersion stability, the above-mentioned M 1 H or NH4 is preferred.

[0144] In the above equation (4d), from the perspective of surface activity energy, the above X 1 Preferably -CF3, from the perspective of water solubility, the above-mentioned n4 is preferably an integer of 5 or less, and from the perspective of obtaining moderate water solubility and surface activity, the above-mentioned Y3 Preferred -COOM 1 The above M 1 H or NH4 is preferred.

[0145] Examples of perfluorovinyl ether compounds represented by the above formula (4d) include CF2=CFOCF2CF(CF3)OCF2CF2COOM. 1 (where M is in the formula) 1 (Indicates H, NH4, or alkali metal).

[0146] In the above formula (4e), from the perspective of emulsifying ability, n5 is preferably an integer from 0 to 5, more preferably 0, 1, or 2, and even more preferably 0 or 1. From the perspective of obtaining suitable water solubility and surface activity, the above Y 3 Preferred -COOM 1 From the perspective of minimizing residue as an impurity and improving the heat resistance of the resulting molded article, the above-mentioned M 1 H or NH4 is preferred.

[0147] Examples of perfluorovinylalkyl compounds represented by formula (4e) above include CH2=CFCF2OCF(CF3)COOM. 1 , CH2=CFCF2OCF(CF3)CF2OCF(CF3)COOM 1 (where M is in the formula) 1 Same as the definition above).

[0148] As the modified monomer mentioned above, from the aspects of further improving the coulombic efficiency of electrochemical devices, further reducing the amount added, further improving the adhesion between the compound tablet and the substrate, and further improving the powder flowability, it is preferably selected from at least one of the group consisting of HFP, PAVE, PFAE and monomers having polar groups, more preferably selected from at least one of the group consisting of HFP, perfluoro(methyl vinyl ether) [PMVE], perfluoro(propyl vinyl ether) [PPVE], PFBE, non-fluorinated monomers having anhydride residues and modified monomer (A), further preferably selected from at least one of the group consisting of HFP, PMVE, PPVE, cyclic non-fluorinated monomers having anhydride residues and compounds represented by general formula (4e), even more preferably selected from at least one of the group consisting of HFP, PMVE and PPVE, and even more preferably HFP.

[0149] The aforementioned TFE-based polymer is preferably at least one of the following groups: homopolymers of TFE and modified PTFE comprising TFE units and HFP-based polymeric units; more preferably, it is at least one of the following groups: homopolymers of TFE and modified PTFE comprising only TFE units and HFP-based polymeric units.

[0150] The aforementioned TFE-based polymers can have a core-shell structure. Examples of TFE-based polymers with a core-shell structure include TFE copolymers containing a core of a high-molecular-weight TFE-based polymer and a shell of a lower-molecular-weight TFE-based polymer or TFE copolymer in the particles. Additionally, examples include modified PTFE containing a core of high-molecular-weight PTFE and a shell of lower-molecular-weight PTFE or modified PTFE in the particles. Examples of such modified PTFE include the PTFE described in Japanese Patent Application Publication No. 2005-527652.

[0151] The aforementioned TFE-based polymers are preferably non-melt processable.

[0152] In this specification, non-melt processability refers to a melt flow rate (MFR) of less than 0.25 g / 10 min, preferably less than 0.10 g / 10 min, more preferably less than 0.05 g / 10 min, and even more preferably less than 0.01 g / 10 min.

[0153] The above MFR is the value obtained according to ASTM D1238, using a melt indexer at 372°C and a load of 5 kg, as the mass (g / 10 min) of polymer flowing out of a nozzle with an inner diameter of 2.095 mm and a length of 8 mm per 10 minutes.

[0154] From the perspectives of further improving the coulombic efficiency of electrochemical devices, further reducing the amount added, further improving the adhesion between the compound tablet and the substrate, and further improving the flowability of the powder, the TII of the above-mentioned TFE-based polymer is preferably 10 or more, more preferably 15 or more, further preferably 20 or more, even more preferably 25 or more, even more preferably 30 or more, even more preferably 35 or more, particularly preferably 40 or more, and preferably 80 or less, more preferably 50 or less.

[0155] TFE-based polymers with a TII of 10 or higher are obtained by using hydrocarbon-based surfactants.

[0156] From the perspective of being able to form compound tablets with superior strength, the standard specific gravity (SSG) of the above-mentioned TFE-based polymer is preferably 2.280 or less, more preferably 2.250 or less, even more preferably 2.220 or less, even more preferably 2.200 or less, even more preferably 2.190 or less, particularly more preferably 2.180 or less, and especially preferably 2.170 or less.

[0157] In addition, the SSG value is preferably 2.130 or higher.

[0158] The above SSG was measured using samples molded according to ASTM D 4895 89 and determined by the water displacement method according to ASTM D 792.

[0159] In the polymer compositions disclosed herein, from the viewpoint of further improving powder flowability, it is preferable that the aforementioned fibrillating polymer has not undergone fibrillation in powder form. The fibrillating polymer not undergoing fibrillation in powder form means that the average aspect ratio of the aforementioned fibrillating polymer in powder form is 2.5 or less.

[0160] The aforementioned average aspect ratio is preferably 2.0 or less, more preferably 1.9 or less, even more preferably 1.8 or less, even more preferably 1.7 or less, even more preferably 1.6 or less, even more preferably 1.5 or less, even more preferably 1.4 or less, even more preferably 1.3 or less, and even more preferably 1.2 or less. Alternatively, the aforementioned average aspect ratio can be 1.0 or more.

[0161] The average major-to-minor ratio was calculated as follows: the powder of the polymer composition was spread thinly on a black paper with air without applying shear, and the fibrillated polymer contained in the polymer composition was observed under a microscope. The images of more than 100 randomly selected particles were processed, and the average ratio of their major-to-minor diameter was calculated.

[0162] From the perspectives of further improving the coulombic efficiency of electrochemical devices, further reducing the amount added, further improving the adhesion between the compound tablet and the substrate, and further improving the flowability of the powder, the content of the aforementioned fibrillable polymer is preferably more than 50% by mass relative to the polymer composition disclosed herein, more preferably 60% by mass or more, even more preferably 65% ​​by mass or more, even more preferably 70% by mass or more, and preferably 99% by mass or less, more preferably 97% by mass or less, even more preferably 95% by mass or less, even more preferably 92% by mass or less, and particularly preferably 90% by mass or less.

[0163] The polymer compositions disclosed herein comprise thermoplastic polymers. Preferably, the thermoplastic polymers do not exhibit fibrillation properties.

[0164] The aforementioned thermoplastic polymer can be a thermoplastic resin or an elastomer.

[0165] The melting point of the aforementioned thermoplastic resin is preferably 100°C or higher, more preferably 115°C or higher, even more preferably 130°C or higher, even more preferably 160°C or higher, particularly preferably 210°C or higher, even more preferably 250°C or higher, even more preferably 255°C or higher, especially preferably 295°C or higher, and preferably less than 324°C, more preferably less than 310°C, also preferably less than 275°C, also preferably less than 270°C, also preferably less than 230°C, also preferably less than 225°C, also preferably less than 200°C, also preferably less than 180°C, and also preferably less than 135°C.

[0166] In this specification, the melting point is the temperature corresponding to the maximum value in the heat of fusion curve when a second heating is performed using a differential scanning calorimeter (DSC) at a rate of 10°C / min.

[0167] Examples of thermoplastic resins include non-fluorinated polymers such as polyethylene, polypropylene, polyamide, polystyrene, thermoplastic polyurethane, polyimide, polyacrylate, polycarbonate, polylactic acid, polyetheretherketone, and polyethylene glycol; and fluoropolymers. Polyethylene and fluoropolymers are preferred, and fluoropolymers are more preferred.

[0168] The melt flow rate of the above-mentioned thermoplastic resin is preferably 0.01 to 500 g / 10 min, more preferably 0.1 to 300 g / 10 min.

[0169] The above melt flow rate is obtained according to ASTM D1238, using a melt indexer, at a test temperature determined according to the type of fluoropolymer (e.g., 372°C for PFA and FEP, and 297°C for ETFE), and a load (e.g., 49 N (5 kg) for PFA, FEP, and ETFE), as the mass (g / 10 min) of polymer flowing out of a nozzle with an inner diameter of 2 mm and a length of 8 mm per 10 minutes.

[0170] As the aforementioned fluoropolymers, preferably fluoropolymers capable of melt processing, examples include tetrafluoroethylene [TFE] / perfluoro(alkyl vinyl ether) [PAVE] copolymer [PFA], TFE / perfluoroallyl ether copolymer, TFE / hexafluoropropylene [HFP] copolymer [FEP], ethylene [Et] / TFE copolymer [ETFE], TFE / HFP / vinylidene fluoride [VdF] copolymer [THV], VdF / TFE copolymer [VT], Et / TFE / HFP copolymer [EFEP], polychlorotrifluoroethylene [PCTFE], chlorotrifluoroethylene [CTFE] / TFE copolymer, Et / CTFE copolymer, polyvinylidene fluoride [PVF], polyvinylidene fluoride [PVdF], etc.

[0171] The PFA is not particularly limited, but a copolymer with a TFE unit to PAVE unit molar ratio (TFE unit / PAVE unit) of 70 / 30 or more and less than 99 / 1 is preferred. A more preferred molar ratio is 70 / 30 or more and 98.9 / 1.1 or less; a further preferred molar ratio is 80 / 20 or more and 98.9 / 1.1 or less; an even more preferred molar ratio is 90 / 10 or more and 99.7 / 0.3 or less; and a particularly preferred molar ratio is 97 / 3 or more and 99 / 1 or less. If there are too few TFE units, the mechanical properties tend to decrease; if there are too many, the melting point is too high and the moldability tends to decrease. The PFA is also preferably derived from copolymers of monomers capable of copolymerizing with TFE and PAVE in the form of 0.1 to 10 mol% monomer units, with a total TFE and PAVE unit content of 90 to 99.9 mol%. Examples of monomers capable of copolymerizing with TFE and PAVE include HFP and CZ. 3 Z 4 =CZ 5 (CF2) n Z 6 (where Z) 3 Z 4 and Z 5 Same or different, indicating hydrogen or fluorine atoms, Z 6 The vinyl monomers and CF2=CF-OCH2-Rf (where n represents an integer from 2 to 10, indicating hydrogen, fluorine, or chlorine atoms) are shown. 7 (where Rf) 7 Alkyl perfluorovinyl ether derivatives, etc., representing perfluoroalkyl groups with 1 to 5 carbon atoms.

[0172] The PFA described above may have functional groups. These functional groups may be contained in the units constituting the PFA, in the terminal groups of the polymer backbone, or introduced into the PFA through plasma treatment or the like.

[0173] As a PFA that contains the aforementioned functional groups in its constituent units, an example of a PFA can be a copolymer of monomers having polar groups.

[0174] Examples of PFAs that contain the aforementioned functional groups in the terminal groups of the polymer backbone include PFAs that have functional groups as terminal groups derived from polymerization initiators, chain transfer agents, etc.

[0175] The aforementioned functional group is preferably a group containing a hydroxyl or carbonyl group, more preferably a group containing a carbonyl group, even more preferably a carbonate group, carboxyl group, haloformyl group, alkoxycarbonyl group or acid anhydride residue, and even more preferably a carboxyl group or acid anhydride residue.

[0176] The monomers with polar groups in the above-mentioned PFA can be either non-fluorinated monomers or fluorinated monomers.

[0177] Examples of non-fluorinated monomers include hydroxyl groups such as hydroxyl ethyl vinyl ether, hydroxyl propyl vinyl ether, hydroxyl butyl vinyl ether, hydroxyisobutyl vinyl ether, and hydroxycyclohexyl vinyl ether; non-fluorinated monomers with carboxyl groups such as acrylic acid, methacrylic acid, itaconic acid, succinic acid, fumaric acid, crotonic acid, maleic acid, citraconic acid, undecenoic acid, and ethynyl dicarboxylic acid; and itaconic anhydride (hereinafter also referred to as "IAH"), citraconic anhydride (hereinafter also referred to as "CAH"), and 5-norbornene-2- Non-fluorinated monomers with anhydride residues, such as 3-dicarboxylic anhydride (hereinafter also referred to as "NAH"), succinic anhydride, fumaric anhydride, and maleic anhydride; non-fluorinated monomers with sulfonate groups, such as vinyl sulfonic acid; non-fluorinated monomers with epoxy groups (glycidyl groups), such as glycidyl vinyl ether and glycidyl allyl ether; non-fluorinated monomers with amino groups, such as aminoalkyl vinyl ether and aminoalkyl allyl ether; non-fluorinated monomers with amide groups, such as (meth)acrylamide and hydroxymethylacrylamide; and non-fluorinated monomers with nitrile groups, such as acrylonitrile and methacrylonitrile.

[0178] Among them, non-fluorinated monomers having carboxyl groups and non-fluorinated monomers having anhydride residues are preferred, non-fluorinated monomers having anhydride residues are more preferred, and cyclic non-fluorinated monomers having anhydride residues are even more preferred.

[0179] The aforementioned monomers with polar groups preferably also include modified monomers having functional groups and hydrophilic groups capable of undergoing free radical polymerization. Examples of such modified monomers include the aforementioned modified monomer (A).

[0180] The melting point of the PFA is preferably above 180°C, more preferably above 230°C, even more preferably above 280°C, even more preferably above 290°C, particularly preferably above 295°C, and preferably below 324°C, more preferably below 320°C, and even more preferably below 310°C.

[0181] As a FEP, there are no particular limitations, but a copolymer with a TFE unit to HFP unit molar ratio (TFE unit / HFP unit) of 70 / 30 or more and less than 99 / 1 is preferred. A more preferred molar ratio is 70 / 30 or more and 98.9 / 1.1 or less, and an even more preferred molar ratio is 80 / 20 or more and 98.9 / 1.1 or less. Furthermore, as a FEP, there are no particular limitations, but a copolymer with a TFE unit to HFP unit mass ratio (TFE unit / HFP unit) of 60 / 40 or more and 98 / 2 or less is preferred. A more preferred mass ratio is 60 / 40 or more and 95 / 5 or less, and an even more preferred mass ratio is 85 / 15 or more and 92 / 8 or less. In addition, as the above-mentioned FEP, perfluoro(alkyl vinyl ether) monomers can be further used as monomers capable of copolymerizing with TFE and HFP, and the modified FEP can be used in the range of 0.1 to 2% by mass of all monomers. If there are too few TFE units, the mechanical properties tend to decrease; if there are too many, the melting point tends to be too high and the moldability tends to decrease. The aforementioned FEP is preferably derived from copolymers in which the monomer units capable of copolymerizing with TFE and HFP are 0.1 to 10 mol%, and the total TFE and HFP units are 90 to 99.9 mol%. Examples of monomers capable of copolymerizing with TFE and HFP include PAVE and alkyl perfluorovinyl ether derivatives.

[0182] Furthermore, the aforementioned FEP can possess functional groups. Examples of such functional groups that illustrate PFA can be cited.

[0183] The melting point of the aforementioned FEP is lower than that of the aforementioned PTFE, preferably 150°C or higher, more preferably 200°C or higher, even more preferably 240°C or higher, even more preferably 250°C or higher, and preferably lower than 324°C, more preferably 320°C or lower, even more preferably 300°C or lower, even more preferably 280°C or lower, and particularly preferably 275°C or lower.

[0184] As an ETFE, a copolymer with a TFE unit to ethylene unit molar ratio (TFE unit / ethylene unit) of 20 / 80 or more and 90 / 10 or less is preferred. A more preferred molar ratio is 37 / 63 or more and 85 / 15 or less, and a further preferred molar ratio is 38 / 62 or more and 80 / 20 or less. The TFE unit to ethylene unit molar ratio (TFE unit / ethylene unit) can be 50 / 50 or more and 99 / 1 or less. ETFE can be a copolymer composed of TFE, ethylene, and monomers capable of copolymerizing with TFE and ethylene. Examples of monomers capable of copolymerization include monomers represented by the following formula: CH2=CX 5 Rf 3 CF2=CFRf 3 CF2=CFORf3 CH2=C(Rf 3 )2 (where X) 5 Rf represents a hydrogen atom or a fluorine atom. 3 (This indicates that it may contain fluoroalkyl groups with ether bonds), wherein, preferably, CF2=CFRf 3 CF2=CFORf 3 and CH2=CX 5 Rf 3 The fluorinated vinyl monomers shown are more preferably HFP and CF2=CF-ORf. 4 (where Rf) 4 Perfluoroalkyl groups (representing alkyl groups with 1 to 5 carbon atoms) are shown as perfluoro(alkyl vinyl ethers) and Rf 3 CH2=CX of fluoroalkyl groups having 1 to 8 carbon atoms 5 Rf 3 The fluorinated vinyl monomers shown are as follows. Additionally, monomers capable of copolymerizing with TFE and ethylene can be aliphatic unsaturated carboxylic acids such as itaconic acid and itaconic anhydride. Monomers capable of copolymerizing with TFE and ethylene can be perfluorobutylethylene, 3,3,4,4,5,5,6,6,7,7,8,8,8-tetrafluoro-1-octene, 2,3,3,4,4,5,5-heptafluoro-1-pentene (CH2=CFCF2CF2CF2H), and 2-trifluoromethyl-3,3,3-trifluoropropylene ((CF3)2C=CH2). The monomers capable of copolymerizing with TFE and ethylene are preferably 0.1 to 10 mol%, more preferably 0.1 to 5 mol%, and particularly preferably 0.2 to 4 mol% relative to all polymerization units. Furthermore, as the above-mentioned ETFE, ETFE modified with monomers capable of copolymerizing with TFE and ethylene in the range of 0 to 20% by mass of all monomers can also be used. Preferred TFE: Ethylene: Monomers capable of copolymerizing with TFE and ethylene = (63-94): (27-2): (1-10).

[0185] Furthermore, the aforementioned ETFE may possess functional groups. Examples of such functional groups include those used to describe PFA.

[0186] The aforementioned ETFE can be a copolymer (EFEP) containing TFE units, ethylene units, and HFP units.

[0187] As described above, the molar ratio of TFE units to ethylene units in the EFEP is preferably 20:80 to 90:10, more preferably 37:63 to 85:15, and even more preferably 38:62 to 80:20. The HFP unit is preferably 0.1 to 30 mol% relative to all polymer units, more preferably 0.1 to 20 mol%. It is preferably composed of 20 to 80 mol% tetrafluoroethylene units, 10 to 80 mol% ethylene units, 0 to 30 mol% hexafluoropropylene units, and 0 to 10 mol% of other monomer units.

[0188] The melting point of the ETFE is preferably 140°C or higher, more preferably 160°C or higher, even more preferably 195°C or higher, even more preferably 210°C or higher, particularly preferably 215°C or higher, and preferably below 324°C, more preferably below 320°C, even more preferably below 300°C, even more preferably below 280°C, and particularly preferably below 270°C.

[0189] The melting point of the EFEP is preferably above 160°C, and more preferably below 200°C.

[0190] Regarding the aforementioned THV, the copolymerization ratio (molar percentage) of TFE, HFP, and VdF is preferably TFE / HFP / VdF = 75–95 / 0.1–10 / 0.1–19, more preferably 77–95 / 1–8 / 1–17 (molar ratio), even more preferably 77–95 / 2–8 / 2–16.5 (molar ratio), and most preferably 77–90 / 3–8 / 5–16 (molar ratio). Additionally, the TFE / HFP / VdF copolymer may also contain 0–20 mol% of other monomers. Other monomers may include at least one monomer selected from the group consisting of perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), trifluorochloroethylene, 2-chloropentafluoropropylene, perfluorinated vinyl ethers (e.g., perfluoroalkoxy vinyl ethers such as CF3OCF2CF2CF2OCF=CF2), perfluoroalkyl vinyl ethers, perfluoro-1,3-butadiene, trifluoroethylene, hexafluoroisobutylene, fluoroethylene, ethylene, propylene and alkyl vinyl ethers, BTFB(H2C=CH-CF2-CF2-Br), BDFE(F2C=CHBr), and BTFE(F2C-CFBr), preferably perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), BTFB(H2C=CH-CF2-CF2-Br), BDFE(F2C=CHBr), and BTFE(F2C-CFBr).

[0191] The melting point of the aforementioned THV is preferably 110°C or higher, more preferably 140°C or higher, even more preferably 160°C or higher, even more preferably 180°C or higher, particularly preferably 220°C or higher, and preferably 300°C or lower, more preferably 270°C or lower, even more preferably 250°C or lower, even more preferably 200°C or lower, especially more preferably 180°C or lower, especially more preferably 160°C or lower, and particularly preferably 130°C or lower.

[0192] VT preferably contains 80.0 to 90.0 mol% of VdF-based polymeric units (also known as "VdF units") relative to all polymeric units.

[0193] If the VdF unit is less than 80.0 mol%, the viscosity of the electrode mixture changes more over time; if it is more than 90.0 mol%, the flexibility of the electrode obtained from the mixture tends to deteriorate.

[0194] The aforementioned VT preferably contains 80.5 mol% or more of VdF units relative to all polymer units, more preferably 82.0 mol% or more. If it contains 82.0 mol% or more, there is a tendency for the cycle characteristics of the battery using the electrode mixture obtained from the present disclosure to become better.

[0195] Furthermore, the VT is more preferably composed of VdF units of 89.0 mol% or less relative to all polymerization units, and even more preferably of 88.9 mol% or less, and particularly preferably of 88.8 mol% or less.

[0196] In addition to VdF units and TFE-based polymeric units (also referred to as "TFE units"), the aforementioned VT may also include polymeric units based on monomers capable of copolymerizing with VdF and TFE. To achieve the effects of this disclosure, the copolymerization of VdF and TFE is sufficient to allow copolymerization of monomers capable of copolymerizing with them without compromising the excellent non-aqueous electrolyte swelling properties of the copolymer, thereby further improving adhesion.

[0197] The content of the polymeric units based on the monomers that can copolymerize with VdF and TFE is preferably less than 3.0 mol% relative to all the polymeric units of VT. If it is 3.0 mol% or more, the crystallinity of the VdF-TFE copolymer is usually significantly reduced, resulting in a tendency for reduced swelling in non-aqueous electrolytes.

[0198] Monomers capable of copolymerizing with the aforementioned VdF and TFE include unsaturated dicarboxylic acid monoesters as described in Japanese Patent Application Publication No. 6-172452, such as monomethyl maleate, monomethyl citrate, monoethyl citrate, and vinylene carbonate; and -NHR, which has -SO3M, -OSO3M, -COOM, -OPO3M (M represents an alkali metal), or as an amine polar group as described in Japanese Patent Application Publication No. 7-201316. 1 -NR 2 R 3 (R 1 R 2 R 3 Compounds containing hydrophilic polar groups such as alkyl groups, for example CH2=CH-CH2-Y, CH2=C(CH3)-CH2-Y, CH2=CH-CH2-O-CO-CH(CH2COOR) 4 CH2=CH-CH2-O-CH2-CH(OH)-CH2-Y, CH2=C(CH3)-CO-O-CH2-CH2-CH2-Y, CH2=CH-CO-O-CH2-CH2-Y, CH2=CHCO-NH-C(CH3)2-CH2-Y (Y represents a hydrophilic polar group; additionally, R...) 4 (representing alkyl groups); and maleic acid, maleic anhydride, etc.

[0199] Furthermore, CH2=CH-CH2-O-(CH2) n -OH(3≦n≦8), [Chemistry 3]

[0200] CH2=CH-CH2-O-(CH2-CH2-O) n -H(1≦n≦14), CH2=CH-CH2-O-(CH2-CH(CH3)-O) n -H(1≦n≦14) and other allyl ether hydroxide monomers, carboxylated and / or -(CF2) n -CF3(3≦n≦8) substituted allyl ethers and ester monomers, such as CH2=CH-CH2-O-CO-C2H4-COOH, CH2=CH-CH2-O-CO-C5H 10 -COOH, CH2=CH-CH2-O-C2H4-(CF2) n CF3, CH2=CH-CH2-CO-O-C2H4-(CF2) n CF3, CH2=C(CH3)-CO-O-CH2-CF3, etc. can also be used as copolymerizable monomers.

[0201] In addition to compounds containing polar groups as mentioned above, the crystallinity of copolymers of vinylidene fluoride and tetrafluoroethylene is slightly reduced, imparting flexibility to the material. This improves adhesion to current collectors made of aluminum or copper foil, as can be inferred from previous research. Therefore, for example, unsaturated hydrocarbon monomers such as ethylene and propylene (CH2=CHR, where R is a hydrogen atom, alkyl group, or halogen such as Cl), and fluorinated monomers such as trifluorochloroethylene, hexafluoropropylene, hexafluoroisobutylene, 2,3,3,3-tetrafluoropropylene, and CF2=CF-OC can also be used. n F 2n+1 (n is an integer greater than or equal to 1), CH2=CF-C n F 2n+1 (n is an integer greater than or equal to 1), CH2 = CF - (CF2CF2) n H (n is an integer greater than or equal to 1), and CF2 = CF-O - (CF2CF(CF3)O) m -C n F 2n+1 (m and n are integers greater than or equal to 1).

[0202] In addition, fluorinated olefinic monomers with at least one functional group, as shown in formula (1), can also be used. [Chemistry 4]

[0203] (In the formula, Y represents -CH2OH, -COOH, carboxyl salt, carboxyl ester group or epoxy group, X and X 1 Whether they are the same or different, they both represent hydrogen atoms or fluorine atoms, R f The monomers are divalent fluorinated alkylene groups with 1 to 40 carbon atoms or divalent fluorinated alkylene groups with ether bonds with 1 to 40 carbon atoms. By copolymerizing one or more of these monomers, the adhesion to the current collector is further improved, and the electrode active material will not peel off from the current collector even after repeated charge and discharge, resulting in good charge and discharge cycle characteristics.

[0204] Among these monomers, hexafluoropropylene and 2,3,3,3-tetrafluoropropylene are particularly preferred from the viewpoint of flexibility and chemical resistance.

[0205] Thus, the VT mentioned above may include other polymer units in addition to VdF units and TFE units, and more preferably it may consist only of VdF units and TFE units.

[0206] The weight-average molecular weight (converted to polystyrene) of the above-mentioned VT is preferably 50,000 to 2,000,000. More preferably, the weight-average molecular weight is 80,000 or more, even more preferably 100,000 or more, more preferably 1,950,000 or less, even more preferably 1,900,000 or less, particularly preferably 1,700,000 or less, and most preferably 1,500,000 or less.

[0207] The above weight-average molecular weight can be determined by gel permeation chromatography (GPC) using N,N-dimethylformamide as a solvent at 50°C.

[0208] The number-average molecular weight (converted to polystyrene) of the above-mentioned VT is preferably between 10,000 and 1,400,000. More preferably, the number-average molecular weight is 16,000 or more, even more preferably 20,000 or more, even more preferably 1,300,000 or less, and even more preferably 1,200,000 or less.

[0209] The number-average molecular weights mentioned above can be determined by gel permeation chromatography (GPC) using N,N-dimethylformamide as a solvent at 50°C.

[0210] The melting point of the above-mentioned VT is preferably above 120°C, more preferably above 130°C, and preferably below 160°C, more preferably below 150°C, even more preferably below 140°C, and even more preferably below 135°C.

[0211] The aforementioned PVdF can be a homopolymer composed solely of VdF-based polymeric units, or it can be a PVdF composed of VdF-based polymeric units and polymeric units based on monomers (α) that can copolymerize with the aforementioned VdF-based polymeric units.

[0212] Examples of the aforementioned monomers (α) include vinyl fluoride, trifluoroethylene, trifluorochloroethylene, fluoroalkyl vinyl ethers, hexafluoropropylene, 2,3,3,3-tetrafluoropropylene, and propylene. Additionally, examples include unsaturated dicarboxylic acid monoesters disclosed in Japanese Patent Application Publication No. 6-172452, such as monomethyl maleate, monomethyl citrate, monoethyl citrate, and vinylene carbonate; and -NHR, which has -SO3M, -OSO3M, -COOM, -OPO3M (M representing an alkali metal), and is an amine-based polar group, as disclosed in Japanese Patent Application Publication No. 7-201316. 1 -NR 2 R 3 (R 1 R 2 R 3 Compounds containing hydrophilic polar groups such as alkyl groups, for example CH2=CH-CH2-Y, CH2=C(CH3)-CH2-Y, CH2=CH-CH2-O-CO-CH(CH2COOR)4 CH2=CH-CH2-O-CH2-CH(OH)-CH2-Y, CH2=C(CH3)-CO-O-CH2-CH2-CH2-Y, CH2=CH-CO-O-CH2-CH2-Y, CH2=CHCO-NH-C(CH3)2-CH2-Y (Y represents a hydrophilic polar group; additionally, R...) 4 (representing alkyl groups); and maleic acid, maleic anhydride, etc.

[0213] Furthermore, CH2=CH-CH2-O-(CH2) n -OH(3≦n≦8), [Chemistry 5]

[0214] CH2=CH-CH2-O-(CH2-CH2-O) n -H(1≦n≦14), CH2=CH-CH2-O-(CH2-CH(CH3)-O) n -H(1≦n≦14) and other allyl ether hydroxide monomers, carboxylated and / or -(CF2) n -CF3(3≦n≦8) substituted allyl ethers and ester monomers, such as CH2=CH-CH2-O-CO-C2H4-COOH, CH2=CH-CH2-O-CO-C5H 10 -COOH, CH2=CH-CH2-O-C2H4-(CF2) n CF3, CH2=CH-CH2-CO-O-C2H4-(CF2) n CF3, CH2=C(CH3)-CO-O-CH2-CF3, etc., can also be used as copolymerizable monomers. Furthermore, besides compounds containing polar groups as mentioned above, slightly reducing the crystallinity of PVdF imparts flexibility to the material, thereby improving adhesion to current collectors made of aluminum or copper foils; this can be inferred from previous research. Therefore, for example, unsaturated hydrocarbon monomers such as ethylene and propylene (CH2=CHR, where R is a hydrogen atom, alkyl group, or halogen such as Cl), and fluorinated monomers such as trifluorochloroethylene, hexafluoropropylene, hexafluoroisobutylene, and CF2=CF-OC can also be used. n F 2n+1 (n is an integer greater than or equal to 1), CH2=CF-C n F 2n+1 (n is an integer greater than or equal to 1), CH2 = CF - (CF2CF2) n H (n is an integer greater than or equal to 1), and CF2 = CF-O - (CF2CF(CF3)O) m -Cn F 2n+1 (m and n are integers greater than or equal to 1).

[0215] In addition, fluorinated olefinic monomers with at least one functional group, as shown in formula (1), can also be used. [Chemistry 6]

[0216] (In the formula, Y represents -CH2OH, -COOH, carboxyl salt, carboxyl ester group or epoxy group, X and X 1 Whether they are the same or different, they both represent hydrogen atoms or fluorine atoms, R f The monomers are divalent fluorinated alkylene groups with 1 to 40 carbon atoms or divalent fluorinated alkylene groups with ether bonds with 1 to 40 carbon atoms. By copolymerizing one or more of these monomers, the adhesion to the current collector is further improved, and the electrode active material will not peel off from the current collector even after repeated charge and discharge, resulting in good charge and discharge cycle characteristics.

[0217] The PVdF mentioned above preferably has a monomer (α) polymerization unit of 5 mol% or less of all polymerization units, more preferably 4.5 mol% or less.

[0218] The weight-average molecular weight (converted to polystyrene) of the PVdF is preferably between 50,000 and 2,000,000. More preferably, the weight-average molecular weight is 80,000 or more, even more preferably 100,000 or more, even more preferably 1,700,000 or less, and even more preferably 1,500,000 or less.

[0219] The above weight-average molecular weight can be determined by gel permeation chromatography (GPC) using N,N-dimethylformamide as a solvent at 50°C.

[0220] The number-average molecular weight (converted from polystyrene) of the above PVdF is 150,000 to 1,400,000.

[0221] If the value is less than 150,000, the adhesion of the resulting electrode will be poor. If the value exceeds 1,400,000, gelation is likely to occur during the preparation of the electrode mixture.

[0222] The number-average molecular weight is preferably 200,000 or more, more preferably 250,000 or more, even more preferably 300,000 or more, preferably 1,300,000 or less, more preferably 1,200,000 or less, even more preferably 1,000,000, and particularly preferably 800,000.

[0223] The number-average molecular weights mentioned above can be determined by gel permeation chromatography (GPC) using N,N-dimethylformamide as a solvent at 50°C.

[0224] The melting point of the PVdF is preferably 130°C or higher, more preferably 150°C or higher, even more preferably 160°C or higher, and preferably 230°C or lower, more preferably 200°C or lower, and even more preferably 180°C or lower.

[0225] The content of each monomer unit in the above copolymer can be calculated by appropriately combining NMR, FT-IR, elemental analysis, and fluorescence X-ray analysis according to the type of monomer.

[0226] The fluoropolymer used as the aforementioned thermoplastic resin is preferably a perfluoropolymer, and more preferably at least one selected from the group consisting of PFA and FEP.

[0227] The fluoropolymer used as the aforementioned thermoplastic resin is preferably a VdF-based polymer, and more preferably at least one selected from the group consisting of PVdF and VT.

[0228] From the perspective of being able to disperse evenly, and having excellent strength and uniformity of the compound tablets, the average particle size of the above-mentioned VdF-based polymer is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 5 μm or less, even more preferably 2 μm or less, and preferably 0.1 μm or more, more preferably 0.5 μm or more.

[0229] The average particle size of VdF-based polymers can be adjusted, for example, by crushing.

[0230] The average particle size was measured using a Beckman Coulter laser diffraction particle size distribution measuring device (LS13320) under dry, vacuum pressure of 20 mH2O, and calculated based on the obtained particle size distribution (volume basis). The average particle size is equal to the particle size corresponding to 50% of the cumulative particle size distribution.

[0231] The aforementioned VdF-based polymers are preferably free of fluorinated surfactants. VdF-based polymers free of fluorinated surfactants can be manufactured, for example, by suspension polymerization.

[0232] As described in the examples below, the absence of fluorinated surfactants in VdF polymers can be confirmed by measuring the amount of fluorinated surfactants as determined by liquid chromatography-mass spectrometry, which is less than the detection limit.

[0233] The glass transition temperature of the above-mentioned elastomer is preferably below 25°C, more preferably below 10°C, even more preferably below 0°C, and preferably above -50°C, more preferably above -30°C.

[0234] Examples of the aforementioned elastomers include nitrile rubber, hydrogenated nitrile rubber, styrene-butadiene rubber (SBR), chloroprene rubber (CR), butadiene rubber (BR), natural rubber (NR), isoprene rubber (IR), ethylene-α-olefin rubber, ethylene-α-olefin-non-conjugated diene rubber, chlorinated polyolefin rubber, chlorosulfonated polyolefin rubber, acrylic rubber, ethylene-based acrylic rubber, epichlorohydrin rubber, silicone rubber, butyl rubber (IIR), ethylene-vinyl ester rubber, ethylene-methacrylate rubber, and other non-fluorinated rubbers; and fluorinated elastomers. Fluorinated elastomers are preferred among the aforementioned elastomers. The aforementioned elastomers can be cross-linked or uncross-linked elastomers.

[0235] Specifically, examples of the aforementioned fluorinated elastomers include vinylidene fluoride (VdF) based fluorinated elastomers, TFE / propylene (Pr) based fluorinated elastomers, TFE / Pr / VdF based fluorinated elastomers, ethylene (Et) / HFP based fluorinated elastomers, Et / HFP / VdF based fluorinated elastomers, Et / HFP / TFE based fluorinated elastomers, fluoroorganosilicon based fluorinated elastomers, and fluorophosphazene based fluorinated elastomers. These can be used individually or in any combination without impairing the effects of this disclosure. VdF based fluorinated elastomers are preferred.

[0236] The aforementioned VdF-based fluorinated elastomer is a fluorinated elastomer comprising VdF units and other monomer units capable of copolymerizing with VdF. In the VdF-based fluorinated elastomer, the content of VdF units relative to the total content of VdF units and other monomer units is preferably 20 mol% to 90 mol%, more preferably 40 mol% to 85 mol%. A further preferred lower limit is 45 mol%, a particularly preferred lower limit is 50 mol%, and a further preferred upper limit is 80 mol%.

[0237] Furthermore, as a comonomer in the aforementioned VdF-based fluorinated elastomers, there are no particular limitations as long as it can copolymerize with VdF. Examples include tetrafluoroethylene (TFE), hexafluoropropylene (HFP), perfluoroalkyl vinyl ether (PAVE), trifluorochloroethylene (CTFE), trifluoroethylene, trifluoropropylene, tetrafluoropropylene, pentafluoropropylene, trifluorobutylene, tetrafluoroisobutylene, hexafluoroisobutylene, fluorinated vinyl ethers containing iodine, and fluorinated monomers represented by general formula (1-1). CH2=CFRf1 (1-1) (In the formula, Rf1 is a straight-chain or branched fluoroalkyl or fluoroalkoxy group with 1 to 12 carbon atoms. If the number of carbon atoms is 2 or more, oxygen atoms may be included between carbon atoms.) Fluorine-containing monomers, such as those represented by general formula (2-1), CHF=CHRf2 (2-1) (In the formula, Rf2 is a straight-chain or branched fluoroalkyl or fluoroalkoxy group with 1 to 12 carbon atoms. If the number of carbon atoms is 2 or more, oxygen atoms may be included between carbon atoms.) Non-fluorinated monomers such as ethylene (Et), propylene (Pr), and alkyl vinyl ethers, monomers that provide crosslinking groups (curing sites), and reactive emulsifiers can be used in combination, with one or more of these monomers or compounds being used.

[0238] In the above general formula (1-1), Rf1 is a straight-chain or branched fluoroalkyl group with 1 to 12 carbon atoms, or a straight-chain or branched fluoroalkoxy group with 1 to 12 carbon atoms. Both fluoroalkyl and fluoroalkoxy groups may contain oxygen atoms (-O-) between carbon atoms when they have 2 or more carbon atoms.

[0239] The fluoroalkyl group of Rf1 can be a partially fluoroalkyl group in which some of the hydrogen atoms bonded to the carbon atom are replaced by fluorine atoms, or it can be a perfluoroalkyl group in which all of the hydrogen atoms bonded to the carbon atom are replaced by fluorine atoms. In addition, the hydrogen atoms of the fluoroalkyl group of Rf1 can be replaced by substituents other than fluorine atoms, but preferably do not contain substituents other than fluorine atoms.

[0240] Furthermore, the fluoroalkoxy group of Rf1 can be a partially fluoroalkoxy group in which a portion of the hydrogen atom bonded to the carbon atom is replaced by a fluorine atom, or a perfluoroalkoxy group in which all the hydrogen atom bonded to the carbon atom is replaced by a fluorine atom. Additionally, the hydrogen atom of the fluoroalkoxy group of Rf1 can be replaced by a substituent other than a fluorine atom, but preferably does not contain any substituents other than a fluorine atom.

[0241] The number of carbon atoms in Rf1 is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 4, and particularly preferably 1.

[0242] In formula (2-1) above, Rf2 is a straight-chain or branched fluoroalkyl group with 1 to 12 carbon atoms, or a straight-chain or branched fluoroalkoxy group with 1 to 12 carbon atoms. Both fluoroalkyl and fluoroalkoxy groups can contain oxygen atoms (-O-) between carbon atoms when they have 2 or more carbon atoms.

[0243] The fluoroalkyl group of Rf2 can be a partially fluoroalkyl group in which some of the hydrogen atoms bonded to the carbon atom are replaced by fluorine atoms, or it can be a perfluoroalkyl group in which all of the hydrogen atoms bonded to the carbon atom are replaced by fluorine atoms. In addition, the hydrogen atoms of the fluoroalkyl group of Rf2 can be replaced by substituents other than fluorine atoms, but preferably do not contain substituents other than fluorine atoms.

[0244] Furthermore, the fluoroalkoxy group of Rf2 can be a partially fluoroalkoxy group in which some of the hydrogen atoms bonded to the carbon atom are replaced by fluorine atoms, or it can be a perfluoroalkoxy group in which all of the hydrogen atoms bonded to the carbon atom are replaced by fluorine atoms. Additionally, the hydrogen atoms of the fluoroalkoxy group of Rf2 can be replaced by substituents other than fluorine atoms, but preferably do not contain substituents other than fluorine atoms.

[0245] The number of carbon atoms in Rf2 is preferably 1 to 10, more preferably 1 to 6, even more preferably 1 to 4, and particularly preferably 1.

[0246] Preferably, the copolymer unit is composed of hexafluoropropylene (HFP), tetrafluoroethylene (TFE), 2,3,3,3-tetrafluoropropylene, 1,3,3,3-tetrafluoropropylene, and perfluoroalkyl vinyl ether (PAVE). Furthermore, it is most preferred that at least a portion of the copolymer unit is hexafluoropropylene (HFP). Examples of vinylidene fluoride-based elastomers in which at least a portion of the copolymer unit is hexafluoropropylene (HFP) include binary elastomers composed of vinylidene fluoride and hexafluoropropylene, and ternary elastomers composed of vinylidene fluoride, tetrafluoroethylene, and hexafluoropropylene.

[0247] As for the aforementioned PAVE, perfluoro(methyl vinyl ether) (PMVE) and perfluoro(propyl vinyl ether) (PPVE) are more preferred, and PMVE is particularly preferred.

[0248] Alternatively, the formula CF2 = CFOCF2ORf can also be used as the above PAVE. c The perfluorovinyl ether shown, (where Rf) c It is a straight-chain or branched perfluoroalkyl group with 1 to 6 carbon atoms, a cyclic perfluoroalkyl group with 5 to 6 carbon atoms, or a straight-chain or branched perfluoroalkyl group with 2 to 6 carbon atoms containing 1 to 3 oxygen atoms. For example, CF2=CFOCF2OCF3, CF2=CFOCF2OCF2CF3 or CF2=CFOCF2OCF2CF2OCF3 are preferred.

[0249] As the aforementioned VdF-based fluorinated elastomer, it is preferable to have at least one copolymer selected from the group consisting of VdF / HFP copolymer, VdF / TFE / HFP copolymer, VdF / CTFE copolymer, VdF / CTFE / TFE copolymer, VdF / PAVE copolymer, VdF / TFE / PAVE copolymer, VdF / HFP / PAVE copolymer, VdF / HFP / TFE / PAVE copolymer, VdF / TFE / Pr copolymer, VdF / Et / HFP copolymer, and copolymers of VdF with fluorinated monomers shown in formula (1-1) or (2-1). Furthermore, as other comonomers besides VdF, it is more preferable to have at least one comonomer selected from the group consisting of TFE, HFP, and PAVE.

[0250] Preferably, it is a copolymer selected from at least one copolymer chosen from the group consisting of VdF / HFP copolymer, VdF / TFE / HFP copolymer, copolymer of VdF / fluorinated monomers shown in formula (1-1) or (2-1), VdF / PAVE copolymer, VdF / TFE / PAVE copolymer, VdF / HFP / PAVE copolymer, and VdF / HFP / TFE / PAVE copolymer, more preferably a copolymer selected from VdF / HFP copolymer, VdF / TFE / HFP copolymer, VdF / fluorinated monomers shown in formula (1-1) or (2-1). At least one copolymer selected from the group consisting of copolymers of fluorinated monomers shown and VdF / PAVE copolymers, more preferably at least one copolymer selected from the group consisting of VdF / HFP copolymers, VdF / TFE / HFP copolymers and VdF / 2,3,3,3-tetrafluoropropylene copolymers shown in formula (1-1), more preferably at least one copolymer selected from the group consisting of VdF / HFP copolymers, VdF / TFE / HFP copolymers and VdF / 2,3,3,3-tetrafluoropropylene copolymers, and particularly preferably VdF / HFP copolymers.

[0251] The VdF / HFP composition of the VdF / HFP copolymer is preferably (45–85) / (55–15) (mol%), more preferably (50–80) / (50–20) (mol%), and even more preferably (60–80) / (40–20) (mol%). The VdF / HFP composition is also preferably (50–78) / (50–22) (mol%).

[0252] The preferred composition of the VdF / TFE / HFP copolymer is (30-80) / (4-35) / (10-35) (molar percentage).

[0253] As a VdF / PAVE copolymer, the VdF / PAVE composition is preferably (65-90) / (35-10) (molar percentage). Alternatively, a VdF / PAVE composition of (50-78) / (50-22) (molar percentage) is also a preferred option.

[0254] As a VdF / TFE / PAVE copolymer, the preferred composition of VdF / TFE / PAVE is (40-80) / (3-40) / (15-35) (molar percentage).

[0255] As a VdF / HFP / PAVE copolymer, the preferred composition of VdF / HFP / PAVE is (65-90) / (3-25) / (3-25) (molar percentage).

[0256] As a VdF / HFP / TFE / PAVE copolymer, the VdF / HFP / TFE / PAVE composition is preferably (40-90) / (0-25) / (0-40) / (3-35) (molar percentage), and more preferably (40-80) / (3-25) / (3-40) / (3-25) (molar percentage).

[0257] As a copolymer of VdF and fluorinated monomers (1-1) or (2-1) as shown in formula (1-1) or (2-1), it is preferable that the VdF / fluorinated monomer (1-1) or (2-1) unit is 87 / 13 to 20 / 80 (mol%), and the VdF and other monomer units besides fluorinated monomers (1-1) or (2-1) are 0 to 50 mol% of all monomer units. More preferably, the mol% ratio of VdF / fluorinated monomer (1-1) or (2-1) unit is 80 / 20 to 20 / 80. In addition, a composition of VdF / fluorinated monomer (1-1) or (2-1) unit of 78 / 22 to 50 / 50 (mol%) is also a preferred embodiment. Furthermore, it is also preferred that the VdF / fluorinated monomer (1-1) or (2-1) unit is 87 / 13 to 50 / 50 (mol%), and that the other monomer units besides VdF and the fluorinated monomer (1-1) or (2-1) are 1 to 50 mol% of all monomer units. As other monomers besides VdF and the fluorinated monomer (1-1) or (2-1), TFE, HFP, PMVE, perfluoroethyl vinyl ether (PEVE), PPVE, CTFE, trifluoroethylene, hexafluoroisobutylene, fluoroethylene, Et, Pr, alkyl vinyl ethers, monomers providing crosslinking groups, and reactive emulsifiers are preferred as comonomers of the above-mentioned VdF, among which PMVE, CTFE, HFP, and TFE are more preferred.

[0258] TFE / Pr-based fluorinated elastomers refer to fluorinated copolymers composed of 45–70 mol% TFE and 55–30 mol% Pr. In addition to these two components, they may also contain 0–40 mol% of a specific third component (e.g., PAVE).

[0259] As an Et / HFP copolymer, the composition of Et / HFP is preferably (35-80) / (65-20) (molar percentage), and more preferably (40-75) / (60-25) (molar percentage).

[0260] The preferred composition of Et / HFP / TFE in the Et / HFP / TFE copolymer is (35-75) / (25-50) / (0-15) (mol%), more preferably (45-75) / (25-45) / (0-10) (mol%).

[0261] Examples of perfluorinated elastomers include substances composed of TFE / PAVE. The composition of TFE / PAVE is preferably (50-90) / (50-10) (mol%), more preferably (50-80) / (50-20) (mol%), and even more preferably (55-75) / (45-25) (mol%).

[0262] As for PAVE at this time, examples include PMVE, PPVE, etc., which can be used individually or in any combination.

[0263] The fluorine content of the fluorinated elastomer is preferably 50% by mass or more, more preferably 55% by mass or more, and even more preferably 60% by mass or more. There is no particular upper limit to the fluorine content, but it is preferably 71% by mass or less.

[0264] The fluorine content is a value calculated from the composition of the fluorinated elastomer measured using 19F-NMR.

[0265] The molecular weight is calculated from the composition ratio, the mass of fluorine atoms contained therein is determined, and the fluorine content is calculated.

[0266] In this disclosure, the composition ratio of each repeating unit of the fluorinated elastomer is a value determined by NMR. Specifically, it is a value determined by the following solution NMR method.

[0267] Measuring apparatus: VNMRS400 manufactured by Varian

[0268] Resonant frequency: 376.04 (Sfrq)

[0269] Pulse width: 30° (pw=6.8)

[0270] The non-perfluorinated and perfluorinated elastomers described above can be manufactured using conventional methods such as emulsion polymerization, suspension polymerization, and solution polymerization. In particular, polymerization methods using iodine (bromine) compounds, known as iodine (bromine) transfer polymerization, can produce fluorinated elastomers with narrow molecular weight distributions.

[0271] The polymer described above may have structural units other than vinylidene fluoride units and copolymer units (A). In this case, the content of other structural units is preferably 50 mol% or less. It should be noted that it may also consist only of vinylidene fluoride units and copolymer units (A). The content of other structural units is more preferably 30 mol% or less, and even more preferably 15 mol% or less.

[0272] The polymers described above may use monomers that provide crosslinking sites as other monomers mentioned above.

[0273] The monomer providing the aforementioned crosslinking site is not particularly limited; for example, the general formula can be used: CX 1 2=CX 1 -Rf 1 CHR 1 X 2 (where X) 1 It can be a hydrogen atom, a fluorine atom, or -CH3, Rf 1 It is a fluoroalkylene group, a perfluoroalkylene group, a fluoro(poly)oxyalkylene group, or a perfluoro(poly)oxyalkylene group, R 1 For hydrogen atoms or -CH3, X 2 Monomers containing iodine or bromine (with iodine or bromine atoms) and general formulas are as follows: CF2=CFO(CF2CF(CF3)O) m (CF2) n -X 3 (In the formula, m is an integer from 0 to 5, n is an integer from 1 to 3, X) 3 Monomers and general formulas represented by cyano, carboxyl, alkoxycarbonyl, iodine, or bromine atoms: CH2=CFCF2O(CF(CF3)CF2O) m (CF(CF3)) n -X 4 (In the formula, m is an integer from 0 to 5, n is an integer from 1 to 3, X) 4 Monomers represented by cyano, carboxyl, alkoxycarbonyl, iodine, bromine or -CH2OH are used as other monomers.

[0274] Preferably, it is selected from at least one of the following groups: CF2=CFOCF2CF(CF3)OCF2CF2CN, CF2=CFOCF2CF(CF3)OCF2CF2COOH, CF2=CFOCF2CF2CH2I, CF2=CFOCF2CF(CF3)OCF2CF2CH2I, CH2=CFCF2OCF(CF3)CF2OCF(CF3)CN, CH2=CFCF2OCF(CF3)CF2OCF(CF3)COOH, and CH2=CFCF2OCF(CF3)CF2OCF(CF3)CH2OH. Alternatively, it may contain repeating units based on monomers providing crosslinking sites, but in one embodiment of this disclosure, it does not contain a crosslinking agent.

[0275] To ensure good adhesion, flexibility, and solubility in solvents, the number-average molecular weight (Mn) of the above-mentioned fluorinated elastomer is preferably 7,000 to 5,000,000, the mass-average molecular weight (Mw) is preferably 10,000 to 10,000,000, and the Mw / Mn ratio is preferably 1.0 to 30.0, more preferably 1.5 to 25.0. The above-mentioned number-average molecular weight (Mn), mass-average molecular weight (Mw), and Mw / Mn are values ​​determined by GPC method.

[0276] The Mooney viscosity (ML1+10(121°C)) of the above-mentioned fluorinated elastomer at 121°C is preferably 2 or more, more preferably 5 or more, even more preferably 10 or more, particularly preferably 30 or more, and can be 200 or less.

[0277] The Mooney viscosity (ML1+10(140°C)) of the fluorinated elastomer at 140°C is preferably 2 or more, more preferably 5 or more, even more preferably 10 or more, even more preferably 30 or more, particularly preferably 50 or more, but can be 200 or less, or 100 or less.

[0278] Mooney viscosity is a value determined according to ASTM-D1646-15 and JIS K6300-1:2013.

[0279] The terminal structure of the above-mentioned fluorinated elastomer preferably satisfies the following inequality: 0.01≦([-CH2OH]+[-COOH]) / ([-CH3]+[-CF2H]+[-CH2OH]+[-CH2I]+[-OC(O)RH]+[-COOH])≦0.25 (In the formula, RH is an alkyl group with 1 to 20 carbon atoms). By making the terminal functional groups satisfy the above formula, the adhesion and flexibility become good, and it has excellent functions.

[0280] It should be noted that satisfying the above general formula does not mean that the fluorinated copolymer has all of the functional groups such as [-CH3], [-CF2H], [-CH2OH], [-CH2I], [-OC(O)RH], and [-COOH], but rather that the ratio of the number of terminal groups present in the fluorinated copolymer is within the above range.

[0281] The presence of terminal groups in fluorinated copolymers can be determined by NMR-based analysis.

[0282] For example, NMR terminal group analysis was performed using proton solution NMR. The sample was analyzed using deuterated acetone (Acetone-d6) as solvent, adjusted to a 20% by mass solution.

[0283] Regarding the reference peak, the peak value of acetone was set to 2.05 ppm.

[0284] Measuring apparatus: VNMRS400 manufactured by Varian

[0285] Resonant frequency: 399.74 (Sfrq)

[0286] Pulse width: 45°

[0287] Make each end correspond to the following peak position.

[0288] [-CH3]: 1.72~1.86ppm

[0289] [-CF2H]: 6.1~6.8ppm

[0290] [-CH2OH]: 3.74~3.80ppm

[0291] [-CH2I]: 3.87~3.92ppm

[0292] [-OC(O)RH]: 1.09~1.16ppm

[0293] [-COOH]: 10~15ppm

[0294] Based on the integral values ​​of each peak determined by the above measurements, the functional group content is calculated from the peak intensity, and the result is used to calculate using the following formula.

[0295] ([-CH2OH]+[-COOH]) / ([-CH3]+[-CF2H]+[-CH2OH]+[-CH2I]+[-OC(O)RH]+[-COOH])

[0296] There are no particular limitations on the method for setting [-CH2OH] and [-COOH] within the range specified above, and they can be controlled by known methods (e.g., the selection and dosage of the initiator used for polymerization).

[0297] The aforementioned thermoplastic polymers can be manufactured using conventional free radical polymerization. The polymerization method can be any of bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization; emulsion polymerization is preferred for ease of industrial implementation.

[0298] In polymerization, polymerization initiators, chain transfer agents, surfactants, and solvents can be used, each of which can be a known substance.

[0299] The copolymers described above can be in any form, such as aqueous dispersions or powders. Regarding copolymer powders, in the case of emulsion polymerization, they can be obtained by precipitating the polymerized dispersion and then washing, dehydrating, and drying it. Precipitation can be achieved by adding inorganic salts or acids such as aluminum sulfate, applying mechanical shear force, or freezing the dispersion. In the case of suspension polymerization, they can be obtained by recovering and drying the polymerized dispersion. In the case of solution polymerization, they can be obtained by drying the solution containing the fluoropolymer as is, or by adding a poor solvent and refining the mixture.

[0300] The aforementioned thermoplastic polymer is preferably selected from at least one of the groups consisting of perfluoropolymers and VdF-based polymers; more preferably, it is selected from at least one of the groups consisting of PFA, FEP, PVdF, VT, and VdF-based fluorinated elastomers; even more preferably, it is selected from at least one of the groups consisting of PFA, FEP, PVdF, VT, VdF / HFP copolymers, VdF / TFE / HFP copolymers, and VdF / 2,3,3,3-tetrafluoropropylene copolymers; even more preferably, it is selected from at least one of the groups consisting of PFA, FEP, PVdF, VT, and VdF / HFP copolymers; and particularly preferably, it is selected from at least one of the groups consisting of PVdF and VT. The aforementioned VdF-based polymers are also preferably fluorinated elastomers.

[0301] From the perspectives of further improving the coulombic efficiency of electrochemical devices, further reducing the amount added, further improving the adhesion between the compound tablet and the substrate, and further improving the flowability of the powder, the content of the above-mentioned thermoplastic polymer relative to the polymer composition disclosed herein is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more, even more preferably 8% by mass or more, particularly preferably 10% by mass or more, and preferably less than 50% by mass, more preferably 45% by mass or less, even more preferably 40% by mass or less, even more preferably 35% by mass or less, and particularly preferably 30% by mass or less.

[0302] The total amount of the fibrillable polymer and the thermoplastic polymer relative to the polymer composition disclosed herein can be 95.0% by mass or more, preferably 98.0% by mass or more, more preferably 99.0% by mass or more, further preferably 99.5% by mass or more, particularly preferably 99.9% by mass or more, and most preferably 99.95% by mass or more.

[0303] The polymer composition (1) disclosed herein comprises at least one compound selected from the group consisting of compounds represented by the following general formula (1) (hereinafter also referred to as compound (1)) and compounds represented by the following general formula (2) (hereinafter also referred to as compound (2)). The polymer composition (2) disclosed herein may comprise the above-mentioned compounds.

[0304] General formula (1): (H-(CF2)) m-1 -COO) p M 1

[0305] (In the formula, m ranges from 4 to 20. M) 1 For H, metal atoms, NR 5 4(R 5 They can be the same or different (either H or an organic group with 1 to 10 carbon atoms), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. p is 1 or 2).

[0306] General formula (2): (H-(CF2)) n -SO3) q M 2

[0307] (In the formula, n is 4 to 20. M) 2 For H, metal atoms, NR 5 4(R 5 (Same as above), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. q is 1 or 2).

[0308] As for the above M 1 and M 2 The aforementioned metal atoms can be categorized as monovalent or divalent metal atoms, and can include alkali metals (Group 1) or alkaline earth metals (Group 2). Specifically, examples include Na, K, and Li.

[0309] 4 Rs 5 They can be the same or different. As R... 5 Preferably, it contains H or an organic group having 1 to 10 carbon atoms, more preferably H or an organic group having 1 to 4 carbon atoms. As R 5 The organic groups are preferably fluorine-free organic groups.

[0310] In general formula (1), m is preferably 6 or more, more preferably 8 or more, even more preferably 11 or more, even more preferably 13 or more, particularly preferably 15 or more, and preferably 18 or less, even more preferably 16 or less.

[0311] In general formula (2), n is preferably 6 or more, more preferably 8 or more, further preferably 11 or more, even more preferably 13 or more, particularly preferably 15 or more, and preferably 18 or less, more preferably 16 or less.

[0312] The polymer composition disclosed herein may contain one or more compounds (1), or two or more compounds, or three or more compounds.

[0313] When the polymer composition disclosed herein contains compound (1), the content of compound (1) (the content of each component if there are two or more) relative to the above polymer composition may be less than 10 ppm by mass, preferably less than 5000 ppb by mass, more preferably less than 1000 ppb by mass, even more preferably less than 500 ppb by mass, even more preferably less than 100 ppb by mass, even more preferably less than 50 ppb by mass, even more preferably less than 25 ppb by mass, and particularly preferably less than 10 ppb by mass.

[0314] The lower limit is not specifically limited and can be 0.1 mass ppb, 1 mass ppb, 10 mass ppb, or 50 mass ppb.

[0315] The polymer composition disclosed herein may contain one or more compounds (2), or two or more compounds, or three or more compounds.

[0316] When the polymer composition of this disclosure contains compound (2), the content of compound (2) (the content of each component if there are two or more) relative to the above polymer composition may be less than 10 ppm by mass, preferably less than 5000 ppb by mass, more preferably less than 1000 ppb by mass, even more preferably less than 500 ppb by mass, even more preferably less than 100 ppb by mass, even more preferably less than 50 ppb by mass, even more preferably less than 25 ppb by mass, even more preferably less than 10 ppb by mass, even more preferably less than 1 ppb by mass, and particularly preferably less than the lower limit of quantitation. The lower limit is not particularly limited and may be an amount less than the lower limit of quantitation.

[0317] The polymer composition comprising compound (1) and / or (2) is obtained by using a hydrocarbon surfactant. The polymer compositions disclosed herein may comprise fibrillating polymers, thermoplastic polymers, compound (1) and / or (2), and a hydrocarbon surfactant. The content of the hydrocarbon surfactant in the above polymer compositions is not particularly limited, but is typically 100 ppm to 10% by mass.

[0318] In the above-mentioned hydrocarbon surfactants, the proportion of hydrogen atoms bonded to carbon atoms that are replaced by fluorine atoms is preferably 50% or less, more preferably 25% or less, further preferably 10% or less, and most preferably 0% (completely unsubstituted by fluorine atoms).

[0319] The polymer compositions disclosed herein preferably do not substantially contain the compounds represented by the following general formula (3) (hereinafter also referred to as compound (3)).

[0320]

[0321] (where M is in the formula) 2 For H, metal atoms, NR 5 4(R 5 The groups can be the same or different, and can be H or an organic group with 1 to 10 carbon atoms (preferably a fluorine-free organic group), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. q is 1 or 2).

[0322] "Substantially not containing compound (3)" means that the content of compound (3) is 25 ppb or less by mass relative to the above polymer composition. The content of compound (3) relative to the above TFE-based polymer is preferably 20 ppb or less by mass, more preferably 15 ppb or less by mass, and even more preferably 10 ppb or less by mass. The lower limit is not particularly limited and can be 0 ppb by mass, 0.1 ppb by mass, or 1 ppb by mass.

[0323] The polymer composition disclosed herein preferably comprises at least one compound selected from the group consisting of a compound represented by the following general formula (4) (hereinafter also referred to as compound (4)) and a compound represented by the following general formula (4') (hereinafter also referred to as compound (4')), the amounts of which are all less than 1000 ppb by mass relative to the above polymer composition.

[0324] General formula (4): (H-(CF2)) 15 -COO) p M 1

[0325] (where M is in the formula) 1 For H, metal atoms, NR 5 4(R 5 The groups can be the same or different, and can be H or an organic group with 1 to 10 carbon atoms (preferably a fluorine-free organic group), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. p is 1 or 2).

[0326] General formula (4'): (H-(CF2)) 16 -COO) p M 1

[0327] (where M is in the formula) 1 For H, metal atoms, NR 5 4(R 5 (Same as above), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. p is 1 or 2).

[0328] When the polymer composition disclosed herein contains compound (4), the content of compound (4) relative to the above polymer composition is more preferably 500 ppb by mass or less, more preferably 250 ppb by mass or less, even more preferably 100 ppb by mass or less, even more preferably 50 ppb by mass or less, even more preferably 25 ppb by mass or less, even more preferably 15 ppb by mass or less, and particularly preferably 10 ppb by mass or less. The lower limit is not particularly limited and can be 0.1 ppb by mass or 1 ppb by mass.

[0329] When the polymer composition disclosed herein contains compound (4'), the content of compound (4') relative to the above polymer composition is more preferably 500 ppb by mass or less, more preferably 250 ppb by mass or less, even more preferably 100 ppb by mass or less, even more preferably 50 ppb by mass or less, even more preferably 25 ppb by mass or less, even more preferably 15 ppb by mass or less, and particularly preferably 10 ppb by mass or less. The lower limit is not particularly limited and can be 0.1 ppb by mass or 1 ppb by mass.

[0330] The polymer composition disclosed herein preferably comprises at least one compound selected from the group consisting of compounds represented by the following general formula (5) (hereinafter also referred to as compound (5)) and compounds represented by the following general formula (5') (hereinafter also referred to as compound (5')), the amounts of which are all less than 1000 ppb by mass relative to the above polymer composition.

[0331] General formula (5): (H-(CF2)) 13 -COO) p M 1

[0332] (where M is in the formula) 1 For H, metal atoms, NR 5 4(R 5 The groups can be the same or different, and can be H or an organic group with 1 to 10 carbon atoms (preferably a fluorine-free organic group), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. p is 1 or 2).

[0333] General formula (5'): (H-(CF2)) 14 -COO) p M 1

[0334] (where M is in the formula) 1 For H, metal atoms, NR 5 4(R 5 (Same as above), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. p is 1 or 2).

[0335] When the polymer composition disclosed herein contains compound (5), the content of compound (5) relative to the above polymer composition is more preferably 500 ppb by mass or less, more preferably 250 ppb by mass or less, even more preferably 100 ppb by mass or less, even more preferably 50 ppb by mass or less, even more preferably 25 ppb by mass or less, even more preferably 15 ppb by mass or less, and particularly preferably 10 ppb by mass or less. The lower limit is not particularly limited and can be 0.1 ppb by mass or 1 ppb by mass.

[0336] When the polymer composition disclosed herein contains compound (5'), the content of compound (5') relative to the above polymer composition is more preferably 500 ppb by mass or less, more preferably 250 ppb by mass or less, even more preferably 100 ppb by mass or less, even more preferably 50 ppb by mass or less, even more preferably 25 ppb by mass or less, even more preferably 15 ppb by mass or less, and particularly preferably 10 ppb by mass or less. The lower limit is not particularly limited and can be 0.1 ppb by mass or 1 ppb by mass.

[0337] The contents of compounds (1), (2), (3), (4), (4'), (5) and (5') were determined using liquid chromatography-mass spectrometry as described in the examples described later.

[0338] The polymer composition disclosed herein is preferably substantially free of moisture. This suppresses gas generation and deterioration of electrochemical device characteristics. Furthermore, a wide range of electrode active materials and solid electrolytes can be selected for combination, which is advantageous in the manufacturing process. "Substantially free of moisture" means that the moisture content relative to the above polymer composition is 0.050% by mass or less.

[0339] The moisture content is preferably 0.030% by mass or less, more preferably 0.010% by mass or less, even more preferably 0.005% by mass or less, even more preferably 0.003% by mass or less, even more preferably 0.002% by mass or less, and particularly preferably 0.001% by mass or less.

[0340] The moisture content was determined using the following method.

[0341] The mass of the polymer composition before and after heating at 150°C for 2 hours was determined and calculated using the following formula. Three samples were taken, and the mass was calculated separately. The average value was then used.

[0342] Moisture content (mass %) = [(mass of the polymer composition before heating (g)) - (mass of the polymer composition after heating (g))] / (mass of the polymer composition before heating (g)) × 100

[0343] The polymer compositions disclosed herein are preferably substantially free of fluorinated compounds with a molecular weight of 1000 or less. "Substantially free of fluorinated compounds" means that the amount of such fluorinated compounds is 25 ppb or less by mass relative to the polymer composition.

[0344] The amount of the aforementioned fluorinated compound is preferably 20 ppb or less by mass, more preferably 15 ppb or less by mass, even more preferably 10 ppb or less by mass, even more preferably less than 10 ppb by mass, even more preferably less than 1 ppb by mass, even more preferably less than 1 ppb by mass, and particularly preferably less than the lower limit of quantitation. The lower limit is not particularly limited and can be an amount less than the lower limit of quantitation.

[0345] The amount of the fluorinated compounds with a molecular weight of less than 1000 was determined by the following method.

[0346] Weigh 1 g of the sample, add 10 g (12.6 ml) of methanol, and sonicate for 60 minutes to obtain an extract. Concentrate the extract by purging with nitrogen. Analyze the fluorine-containing compounds in the concentrated extract using LC / MS / MS. Select the molecular weight information from the obtained LC / MS spectrum to confirm its consistency with the structural formula of the candidate fluorine-containing compounds. Prepare aqueous solutions of the standard substance at five or more levels of concentration, and perform LC / MS analysis on each concentration. Plot the relationship between the concentration and the area of ​​the region relative to that concentration to create a calibration curve. Using the calibration curve, convert the area of ​​the LC / MS chromatogram of the fluorine-containing compounds in the extract into the concentration of the fluorine-containing compounds.

[0347] It should be noted that the limit of quantitation in this assay method is 10 ppb by mass.

[0348] Examples of fluorinated compounds with a molecular weight of 1000 or less include those with a molecular weight of 1000 g / mol or less and containing a hydrophilic group. The molecular weight of the aforementioned fluorinated compounds is preferably 800 or less, more preferably 500 or less.

[0349] Polymer particles obtained by polymerization in the presence of fluorinated surfactants typically contain the fluorinated surfactant in addition to the target polymer. In this specification, the fluorinated surfactant is used during polymerization.

[0350] The aforementioned fluorinated compounds with a molecular weight of less than 1000 can be compounds that were not added during polymerization, such as compounds that are byproducts produced during polymerization.

[0351] It should be noted that, when referring to fluorinated compounds with a molecular weight of 1000 or less, including both anionic and cationic portions, this means fluorinated compounds in which the molecular weight of the anionic portion is 1000 or less. These fluorinated compounds with a molecular weight of 1000 or less do not include fibrillable polymers or thermoplastic polymers.

[0352] As the aforementioned hydrophilic group, it can be, for example, -COOM, -SO2M, or -SO3M. Examples include -COOM and -SO3M (in each formula, M is H, a metal atom, or NR). 1 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 1 Anionic groups such as H (or organic groups).

[0353] As the aforementioned fluorinated surfactants, fluorinated surfactants with anionic moiety molecular weight of 1000 or less (anionic fluorinated surfactants) can also be used. The term "anionic moiety" refers to the portion of the aforementioned fluorinated surfactant other than the cationic moiety. For example, in F(CF2)... n1 In the case of COOM, it is "F(CF2)". n1 The "COO" part.

[0354] As examples of the aforementioned anionic fluorinated surfactants, the following general formula (N 0 The compound shown is )

[0355] (where X) n0 It can be H, Cl, or F. Rf n0 Y is a chain, branched, or cyclic alkylene group having 3 to 20 carbon atoms, in which some or all of the H atoms are substituted with F. This alkylene group may contain more than one ether bond, and some of the H atoms may be substituted with Cl. 0 (It is an anionic group).

[0356] Y 0 The anionic group can be -COOM, -SO2M or -SO3M.

[0357] M represents H, a metal atom, and NR. 1 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 1 It is an H or an organic group.

[0358] Examples of metal atoms mentioned above include alkali metals (Group 1) and alkaline earth metals (Group 2), such as Na, K, or Li.

[0359] As R 1 It can be H or C 1-10 The organic group can be H or C. 1-4 The organic group can be H or C. 1-4 Alkyl groups.

[0360] M can be H, a metal atom, or NR. 1 4 can be H, alkali metals (Group 1), alkaline earth metals (Group 2), or NR. 1 4 can be H, Na, K, Li or NH4.

[0361] The above Rf n0 In this process, more than 50% of H can be replaced by fluorine.

[0362] The aforementioned fluorinated surfactant can be a single fluorinated surfactant or a mixture containing two or more fluorinated surfactants.

[0363] Examples of fluorinated surfactants include compounds represented by the following formulas. Fluorinated surfactants can be mixtures of these compounds.

[0364] F(CF2)7COOM、 F(CF2)5COOM, CF3O(CF2)3OCHFCF2COOM, C3F7OCF(CF3)CF2OCF(CF3)COOM, CF3CF2CF2OCF(CF3)COOM, CF3CF2OCF2CF2OCF2COOM, C2F5OCF(CF3)CF2OCF(CF3)COOM, CF3OCF(CF3)CF2OCF(CF3)COOM, CF2ClCF2CF2OCF(CF3)CF2OCF2COOM, CF2ClCF2CF2OCF2CF(CF3)OCF2COOM, CF2ClCF(CF3)OCF(CF3)CF2OCF2COOM, CF2ClCF(CF3)OCF2CF(CF3)OCF2COOM, and [Chemistry 7]

[0365] (In each formula, M represents H, a metal atom, and NR) 14. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 1 (H or organic groups).

[0366] The polymer compositions disclosed herein preferably do not substantially contain any of the fluorinated compounds shown in the above formulas.

[0367] In the above formulas, M can be H, a metal atom, or NR. 1 4 can be H, alkali metals (Group 1), alkaline earth metals (Group 2), or NR. 1 4 can be H, Na, K, Li or NH4.

[0368] R 1 It can be H or C 1-10 The organic group can be H or C. 1-4 The organic group can be H or C. 1-4 Alkyl groups.

[0369] When the polymer composition disclosed herein is substantially free of any of the fluorinated compounds shown in the above formula, it can further suppress gas generation and degradation of electrochemical device characteristics.

[0370] "Substantively free of any of the fluorinated compounds shown in the above formula" means that the amount of the fluorinated compound is less than 25 ppb by mass relative to the above polymer composition.

[0371] The amount of the aforementioned fluorinated compound is preferably 20 ppb or less by mass, more preferably 15 ppb or less by mass, even more preferably 10 ppb or less by mass, even more preferably less than 10 ppb by mass, even more preferably less than 1 ppb by mass, even more preferably less than 1 ppb by mass, and particularly preferably less than the lower limit of quantitation. The lower limit is not particularly limited and can be an amount less than the lower limit of quantitation.

[0372] The polymer compositions disclosed herein are also preferably substantially free of fluorinated compounds represented by the following general formula: [C n-1 F 2n-1 COO - M + (In the formula, n is an integer from 9 to 14, preferably an integer from 9 to 12, M) + (This indicates a cation). Therefore, it is possible to further suppress gas generation and the degradation of electrochemical device characteristics.

[0373] The cation M that constitutes the above formula + The M is the same as the M mentioned above.

[0374] The absence of fluorinated compounds as shown in the above formula means that the amount of such fluorinated compounds is less than 25 ppb by mass relative to the above polymer composition.

[0375] The amount of the aforementioned fluorinated compound is preferably 20 ppb or less by mass, more preferably 15 ppb or less by mass, even more preferably 10 ppb or less by mass, even more preferably less than 10 ppb by mass, even more preferably less than 1 ppb by mass, even more preferably less than 1 ppb by mass, and particularly preferably less than the lower limit of quantitation. The lower limit is not particularly limited and can be an amount less than the lower limit of quantitation.

[0376] The polymer compositions disclosed herein preferably have endothermic peaks in regions below and above 330°C. The presence of endothermic peaks in these regions indicates that the polymer composition comprises fibrillable polymers and thermoplastic polymers.

[0377] The temperature range of the region below 330°C (also referred to as region (A)) is preferably less than 330°C, and more preferably 320°C or higher, more preferably 324°C or higher, and even more preferably 326°C or higher.

[0378] The temperature range of the region exceeding 330°C (also referred to as region (B)) is preferably 333°C or higher, more preferably 335°C or higher, even more preferably 340°C or higher, and preferably 350°C or lower, more preferably 348°C or lower, and even more preferably 346°C or lower.

[0379] The polymer compositions disclosed herein preferably have an endothermic peak in at least the region of 130–200 °C (also referred to as region (C)). The presence of an endothermic peak in region (C) indicates that the polymer composition comprises at least one VdF-based polymer selected from the group consisting of PVdF and VT as a thermoplastic polymer.

[0380] The temperature range of region (C) is preferably below 190°C, more preferably below 180°C, and even more preferably above 140°C.

[0381] Regarding the endothermic peak temperature mentioned above, the temperatures corresponding to the minimum points in regions (A) to (C) of the heat of fusion curve when the polymer composition has not been heated to a temperature above 300°C is heated at a rate of 10°C / min using a differential scanning calorimeter (DSC).

[0382] The 0.1% mass reduction temperature of the polymer composition disclosed herein is preferably 340°C or higher. A 0.1% mass reduction temperature within the above range indicates that the polymer composition contains perfluoropolymers such as PFA and FEP as thermoplastic polymers.

[0383] The temperature at which the mass decreases by 0.1% is more preferably 350°C or higher, more preferably 370°C or higher, and preferably 400°C or lower, more preferably 390°C or lower.

[0384] The aforementioned 0.1% mass reduction temperature is a value determined by the following method.

[0385] Approximately 10 mg of the polymer composition, which has not been heated to temperatures above 300°C, is accurately weighed and placed in a dedicated aluminum pan for TG-DTA (differential thermal-thermogravimetric analysis). The 0.1% mass reduction temperature is defined as the temperature at which a 0.1% mass reduction occurs when the aluminum pan is heated at 10°C / min in atmospheric conditions over a temperature range from 25°C to 600°C.

[0386] The 1.0% mass reduction temperature of the polymer composition disclosed herein is preferably 370°C or higher.

[0387] A 1.0% mass reduction temperature within the above range indicates that the polymer composition contains perfluoropolymers such as PFA and FEP as thermoplastic polymers.

[0388] The aforementioned 1.0% mass reduction temperature is more preferably 400°C or higher, more preferably 420°C or higher, even more preferably 440°C or higher, even more preferably 460°C or higher, and preferably 492°C or lower.

[0389] The 1.0% mass reduction temperature mentioned above is a value determined by the following method.

[0390] Approximately 10 mg of the polymer composition, which has not been heated to temperatures above 300°C, is accurately weighed and placed in a dedicated aluminum pan for TG-DTA (differential thermal-thermogravimetric analysis). The 1.0% mass reduction temperature is defined as the temperature at which a 1.0% mass reduction occurs when the aluminum pan is heated at 10°C / min in atmospheric conditions over a temperature range from 25°C to 600°C.

[0391] From the perspective of further improving powder flowability, the average aspect ratio of the polymer composition in powder form disclosed herein is preferably 2.5 or less, more preferably 2.0 or less, even more preferably 1.9 or less, even more preferably 1.8 or less, even more preferably 1.7 or less, even more preferably 1.6 or less, even more preferably 1.5 or less, even more preferably 1.4 or less, even more preferably 1.3 or less, and particularly preferably 1.2 or less. Furthermore, the aforementioned average aspect ratio can be 1.0 or more.

[0392] The average length-to-diameter ratio was calculated as follows: the polymer composition powder was spread thinly on a black paper with air without applying shear, the polymer composition was observed with an electron microscope, and the images of more than 100 randomly selected particles were processed, and the average ratio of their length-to-diameter ratio was calculated.

[0393] The average secondary particle size of the polymer composition disclosed herein can be 350 μm or more, preferably 400 μm or more, more preferably 450 μm or more, even more preferably 500 μm or more, even more preferably 550 μm or more, particularly preferably 600 μm or more, and preferably 1000 μm or less, more preferably 900 μm or less, even more preferably 800 μm or less, and even more preferably 700 μm or less.

[0394] The average secondary particle size was determined according to JIS K 6891.

[0395] From the perspective of excellent processability, the apparent density of the polymer composition disclosed herein is preferably 0.40 g / ml or more, more preferably 0.43 g / ml or more, further preferably 0.45 g / ml or more, even more preferably 0.48 g / ml or more, and particularly preferably 0.50 g / ml or more. There is no particular upper limit, and it can be 0.70 g / ml.

[0396] The apparent density was determined according to JIS K 6892.

[0397] The form of the polymer composition disclosed herein is not limited, but from the viewpoint of being able to mix with electrode active materials and solid electrolytes without using a large amount of dispersion medium, powder is preferred.

[0398] It should be noted that the above-mentioned TFE-based polymer composition can be in forms other than powder, such as dispersion or molded body.

[0399] The polymer composition disclosed herein can be manufactured by mixing a fibrillating polymer and a thermoplastic polymer. The mixing method is not limited; the fibrillating polymer and the thermoplastic polymer can be mixed in powder form, in aqueous dispersion form, or in both aqueous dispersion and powder form. From the viewpoint of achieving more uniform mixing, it is preferable to mix the two in aqueous dispersion form, or in both aqueous dispersion and powder form, and more preferably in aqueous dispersion form.

[0400] The polymer composition disclosed herein can be suitably manufactured, for example, by a manufacturing method comprising the following steps: a step (A) of mixing an aqueous dispersion of a fibrillating polymer with an aqueous dispersion or powder of a thermoplastic polymer; a step (B) of precipitating the mixed aqueous dispersion to obtain a wetted powder; and a step (C) of drying (heat treatment) the wetted powder.

[0401] The aforementioned aqueous dispersion of fibrillable polymer can be manufactured, for example, by a manufacturing method that includes the step of emulsion polymerization of the necessary monomers in an aqueous medium in the presence of a hydrocarbon surfactant.

[0402] The following is a detailed description of the method for manufacturing an aqueous dispersion when the fibrillating polymer is a TFE-based polymer.

[0403] In hydrocarbon-based surfactants, the proportion of hydrogen atoms bonded to carbon atoms that are replaced by fluorine atoms is preferably 50% or less, more preferably 25% or less, further preferably 10% or less, and most preferably 0% (completely unsubstituted by fluorine atoms).

[0404] The aforementioned hydrocarbon surfactants are preferably carboxylic acid type hydrocarbon surfactants. As for the aforementioned carboxylic acid type hydrocarbon surfactants, there are no limitations as long as they have a carboxyl group (-COOH) or a group in which the hydrogen atom of the carboxyl group is replaced by an inorganic cation (e.g., a metal atom, ammonium, etc.). For example, specific hydrocarbon surfactants described later, or other hydrocarbon surfactants with surface-active properties that have a carboxyl group or a group in which the hydrogen atom of the carboxyl group is replaced by an inorganic cation, can be used.

[0405] The aforementioned hydrocarbon surfactants are preferably sulfonic acid type hydrocarbon surfactants. As for the aforementioned sulfonic acid type hydrocarbon surfactants, there are no limitations as long as they have a -SO3H group, a -OSO3H group, or groups in which the hydrogen atoms of these groups are replaced by inorganic cations (e.g., metal atoms, ammonium, etc.). For example, specific hydrocarbon surfactants described later, or other hydrocarbon surfactants with surface-active properties having a -SO3H group, a -OSO3H group, or groups in which the hydrogen atoms of these groups are replaced by inorganic cations, can be used.

[0406] From the perspective of good emulsifying performance, the aforementioned hydrocarbon-based surfactant preferably exhibits water solubility. Water solubility of the hydrocarbon-based surfactant means that the maximum concentration of the surfactant dissolved in water at 85°C is 100 ppm by mass or more. The maximum concentration in water is preferably 500 ppm by mass or more, more preferably 1000 ppm by mass or more, further preferably 2000 ppm by mass or more, even more preferably 3000 ppm by mass or more, even more preferably 5000 ppm by mass or more, even more preferably 1% by mass or more, even more preferably 3% by mass or more, even more preferably 5% by mass or more, particularly preferably 10% by mass or more, and may be 50% by mass or less.

[0407] The emulsion polymerization described above preferably includes: a step of carrying out emulsion polymerization of tetrafluoroethylene alone, or emulsion polymerization of tetrafluoroethylene and a modified monomer capable of copolymerizing with the aforementioned tetrafluoroethylene, in an aqueous medium in the presence of a specific hydrocarbon surfactant; and a step of continuously adding the specific hydrocarbon surfactant in the aforementioned steps.

[0408] Continuous addition of a specific hydrocarbon surfactant refers to the addition of the specific hydrocarbon surfactant over a period of time without interruption or in batches, rather than all at once. The specific hydrocarbon surfactant is, for example, a hydrocarbon surfactant having one or more carbonyl groups (excluding the carbonyl group in the carboxyl group), or a hydrocarbon surfactant obtained by free radical treatment or oxidation treatment of a hydrocarbon surfactant having one or more carbonyl groups (excluding the carbonyl group in the carboxyl group). The aforementioned free radical treatment is any treatment that causes the hydrocarbon surfactant having one or more carbonyl groups (excluding the carbonyl group in the carboxyl group) to generate free radicals. For example, it can be the following treatment: adding deionized water and the hydrocarbon surfactant to a reactor, sealing the reactor, purging the system with nitrogen, heating and pressurizing the reactor, adding a polymerization initiator, stirring for a certain period, depressurizing until the reactor reaches atmospheric pressure, and then cooling. The aforementioned oxidation treatment is the treatment of adding an oxidant to a hydrocarbon surfactant having one or more carbonyl groups (excluding the carbonyl group in the carboxyl group). Examples of oxidizing agents include oxygen, ozone, hydrogen peroxide, manganese oxide (IV), potassium permanganate, potassium dichromate, nitric acid, and sulfur dioxide. Using the above manufacturing method, TFE-based polymers with the same molecular weight as those produced using existing fluorinated surfactants can be manufactured even without the use of existing fluorinated surfactants.

[0409] In the above manufacturing method, the step of continuously adding the specific hydrocarbon surfactant preferably begins when the solid content of the TFE-based polymer formed in the aqueous medium is less than 0.60% by mass. More preferably, the specific hydrocarbon surfactant is added when the solid content is 0.5% by mass or less. More preferably, the specific hydrocarbon surfactant is added when the solid content is 0.3% by mass or less, even more preferably when it is 0.2% by mass or less, and even more preferably when it is 0.1% by mass or less. Particularly preferably, the addition begins simultaneously with the start of polymerization. The solid content refers to the concentration relative to the total concentration of the aqueous medium and the TFE-based polymer.

[0410] In the above-described process of continuously adding a specific hydrocarbon surfactant, the amount of the specific hydrocarbon surfactant added relative to 100% by mass of the aqueous medium is preferably 0.01 to 10% by mass. More preferably, the lower limit is 0.05% by mass, and even more preferably, the lower limit is 0.1% by mass. More preferably, the upper limit is 5% by mass, and even more preferably, the upper limit is 1% by mass.

[0411] In the process of emulsion polymerization of tetrafluoroethylene alone, or emulsion polymerization of tetrafluoroethylene and a modified monomer capable of copolymerizing with the aforementioned specific hydrocarbon surfactant in an aqueous medium, the amount of the aforementioned specific hydrocarbon surfactant is preferably high, preferably 0.0001 to 10% by mass relative to 100% by mass of the aqueous medium. A more preferred lower limit is 0.001% by mass, and a more preferred upper limit is 1% by mass. When the amount is less than 0.0001% by mass, the dispersing force may be insufficient; when the amount is greater than 10% by mass, while the effect is proportional to the amount, it may instead cause a decrease in polymerization rate or cessation of the reaction. The amount of the aforementioned specific hydrocarbon surfactant is appropriately determined based on the type of monomer used, the molecular weight of the target TFE-based polymer, etc.

[0412] As the specific hydrocarbon surfactant mentioned above, at least one of the surfactants represented by free formula RX and surfactants (e) described later is preferred (where R is a non-fluorinated organic group having 1 to 2000 carbon atoms having one or more carbonyl groups (excluding the carbonyl groups in the carboxyl groups), and X is -OSO3X). 1 -COOX 1 or -SO3X 1 (X 1 For H, metal atoms, NR 1 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 1R is H or an organic group (preferably a fluorine-free organic group, which may be the same or different). R preferably has 500 or less carbon atoms, more preferably 100 or less, further preferably 50 or less, and even more preferably 30 or less.

[0413] As the specific hydrocarbon-based surfactant mentioned above, at least one surfactant selected from the group consisting of the surfactants described below, specifically surfactant (a) represented by formula (a) below, is preferred. [Chemistry 8]

[0414] (where R is in the formula) 1a It is a straight-chain or branched alkyl group with 1 or more carbon atoms, or a cyclic alkyl group with 3 or more carbon atoms. The hydrogen atoms bonded to the carbon atoms can be replaced by hydroxyl groups or monovalent organic groups containing ester bonds (preferably non-fluorine organic groups). If it has 2 or more carbon atoms, it can contain a carbonyl group. If it has 3 or more carbon atoms, it can contain monovalent or divalent heterocycles, or it can form a ring. R 2a and R 3a Independently a single bond or a divalent linker. R 1a R 2a and R 3a The total number of carbon atoms is 6 or more. X a For H, metal atoms, NR 4a 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 4a It can be H or an organic group (preferably a fluorine-free organic group), and can be the same or different. R 1a R 2a and R 3a Any two of them can bond together to form a ring; The surfactant (b) shown in formula (b) below, [Chemistry 9]

[0415] (where R is in the formula) 1b It is a straight-chain or branched alkyl group with one or more carbon atoms, with or without substituents, or a cyclic alkyl group with three or more carbon atoms, with or without substituents. When it has three or more carbon atoms, it may contain monovalent or divalent heterocycles, or it may form a ring. R 2b and R 4b Independently, it can be H or a substituent. R 3b It is an alkylene group with 1 to 10 carbon atoms, with or without substituents. n is an integer greater than or equal to 1. p and q are independently integers greater than or equal to 0. X b For H, metal atoms, NR5b 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 5b R can be H or an organic group (preferably a fluorine-free organic group), and can be the same or different. 1b R 2b R 3b and R 4b Any two bonds in the group can bond together to form a ring. L is a single bond, -CO2-B- -OCO-B- -CONR 6b -B- -NR 6b CO-B- Or -CO- (where -CO2-B-, -OCO-B-, -CONR) 6b -B-、-NR 6 (excluding the carbonyl group contained in CO-B-), B is a single bond or an alkylene group with or without substituents, having 1 to 10 carbon atoms, R 6b It is H or an alkyl group with or without substituents, having 1 to 4 carbon atoms. This refers to -OSO3X in the formula. b (The bonded side); The surfactant (c) shown in the following formula (c) [Chemistry 10]

[0416] (where R is in the formula) 1c It is a straight-chain or branched alkyl group with 1 or more carbon atoms, or a cyclic alkyl group with 3 or more carbon atoms. The hydrogen atoms bonded to the carbon atoms can be replaced by hydroxyl groups or monovalent organic groups containing ester bonds (preferably non-fluorine organic groups). If it has 2 or more carbon atoms, it can contain a carbonyl group. If it has 3 or more carbon atoms, it can contain monovalent or divalent heterocycles, or it can form a ring. R 2c and R 3c Independently a single bond or a divalent linker. R 1c R 2c and R 3c The total number of carbon atoms is 5 or more. A c For -COOX c or -SO3X c (X c For H, metal atoms, NR 4c 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 4cR is an H group or an organic group (preferably a fluorine-free organic group, which can be the same or different). 1c R 2c and R 3c Any two of them can bond together to form a ring; The surfactant (d) shown in the following formula (d) [Chemistry 11]

[0417] (where R is in the formula) 1d It is a straight-chain or branched alkyl group with one or more carbon atoms, with or without substituents, or a cyclic alkyl group with three or more carbon atoms, with or without substituents. When it has three or more carbon atoms, it may contain monovalent or divalent heterocycles, or it may form a ring. R 2d and R 4d Independently, it can be H or a substituent. R 3d It is an alkylene group with 1 to 10 carbon atoms, with or without substituents. n is an integer greater than or equal to 1. p and q are independently integers greater than or equal to 0. A d -SO3X d or -COOX d (X d For H, metal atoms, NR 5d 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 5d R is an H group or an organic group (preferably a fluorine-free organic group, which can be the same or different). 1d R 2d R 3d and R 4d Any two bonds in the group can bond together to form a ring. L is a single bond, -CO2-B- -OCO-B- -CONR 6d -B- -NR 6d CO-B- Or -CO- (where -CO2-B-, -OCO-B-, -CONR) 6d -B-、-NR 6d (excluding the carbonyl group contained in CO-B-), B is a single bond or an alkylene group with or without substituents, having 1 to 10 carbon atoms, R 6d It is H or an alkyl group with or without substituents, having 1 to 4 carbon atoms. This refers to A in the formula. d (the bonded side); and

[0418] The surfactant (e) shown in the following formula (e) [Chemistry 12]

[0419] (where R is in the formula) 1e ~R 5e Represents H or a monovalent substituent, where R 1e and R 3e At least one of the general formulas in the formula is: -Y e -R 6e The groups shown, R 2e and R 5e At least one of the following represents the general formula: -X e -A e The indicated group, or general formula: -Y e -R 6e The group shown.

[0420] Additionally, X e The presence of the same or different elements in different instances indicates a divalent linking group or bond; A e The same or different occurrences indicate -COOM e -SO3M e or -OSO3M e (M e For H, metal atoms, NR 7e 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 7e It is an H group or an organic group (preferably a fluorine-free organic group); Y e The fact that they appear the same or different indicates that the choice is free from -S(=O)2-, -O-, -COO-, -OCO-, -CONR. 8e -and-NR 8e The divalent linking group or bond in the CO- group, R 8e Indicates H or an organic group (preferably a fluorine-free organic group); R 6e The same or different in each occurrence indicates that at least one alkyl group with two or more carbon atoms selected from the group consisting of carbonyl, ester, amide and sulfonyl groups may be included between carbon atoms; R 1e ~R 5e Any two of them can bond together to form a ring.

[0421] Surfactant (a) can be manufactured, for example, by the manufacturing method described in International Publication No. 2020 / 022355.

[0422] Surfactant (b) can be manufactured, for example, by the manufacturing method described in International Publication No. 2020 / 022355.

[0423] Surfactant (c) can be manufactured, for example, by the manufacturing method described in International Publication No. 2020 / 022355.

[0424] Surfactant (d) can be manufactured, for example, by the manufacturing method described in International Publication No. 2020 / 022355.

[0425] Surfactants (e) can be manufactured using known manufacturing methods.

[0426] The aforementioned specific hydrocarbon surfactants are preferably carboxylic acid type hydrocarbon surfactants. As for the aforementioned carboxylic acid type hydrocarbon surfactants, there are no limitations as long as they have a carboxyl group (-COOH) or a group in which the hydrogen atom of the carboxyl group is replaced by an inorganic cation (e.g., a metal atom, ammonium, etc.). For example, the aforementioned specific hydrocarbon surfactants can be used that have a carboxyl group or a group in which the hydrogen atom of the carboxyl group is replaced by an inorganic cation.

[0427] The aforementioned carboxylic acid-based hydrocarbon surfactant preferably has a fluorine atom substitution ratio of 50% or less, more preferably 25% or less, further preferably 10% or less, and most preferably 0% (completely unsubstituted by fluorine atoms).

[0428] As the above-mentioned carboxylic acid type hydrocarbon surfactant, it is preferred to be a surfactant having a carboxyl group (-COOH) or a group in which the hydrogen atom of the carboxyl group is replaced by an inorganic cation (e.g., a metal atom, ammonium, etc.) from at least one of the surfactants (c) and (d) shown in the above formula (c) and the surfactant (d) shown in the above formula (d).

[0429] Furthermore, the aforementioned specific hydrocarbon surfactants are preferably sulfonic acid type hydrocarbon surfactants. As for the aforementioned sulfonic acid type hydrocarbon surfactants, there are no limitations as long as they have a -SO3H group, a -OSO3H group, or a group in which the hydrogen atoms of these groups are replaced by inorganic cations (e.g., metal atoms, ammonium, etc.). For example, hydrocarbon surfactants with -SO3H groups, -OSO3H groups, or groups in which the hydrogen atoms of these groups are replaced by inorganic cations can be used.

[0430] The sulfonic acid-based hydrocarbon surfactants described above preferably have a fluorine atom substitution ratio of 50% or less, more preferably 25% or less, further preferably 10% or less, and most preferably 0% (completely unsubstituted by fluorine atoms).

[0431] The polymer composition disclosed herein can be efficiently manufactured using only at least one of the aforementioned specific hydrocarbon surfactants. Furthermore, the polymer composition disclosed herein can be manufactured using two or more of the aforementioned specific hydrocarbon surfactants simultaneously, or using other surface-active compounds besides the aforementioned specific hydrocarbon surfactants, as long as they are volatile or can remain in molded articles or the like made of TFE-based polymers.

[0432] Other compounds with surface-active properties may be used, for example, the substances described in Japanese Patent Application Publication Nos. 2013-542308, 2013-542309, and 2013-542310.

[0433] Other compounds with surface-active properties can be surfactants having both hydrophilic and hydrophobic portions on the same molecule, such as hydrocarbon surfactants (except for the specific hydrocarbon surfactants mentioned above). They can be cationic, nonionic, or anionic.

[0434] The proportion of hydrogen atoms bonded to carbon atoms in the above-mentioned compounds that are replaced by fluorine atoms is preferably 50% or less, more preferably 25% or less, further preferably 10% or less, and most preferably 0% (completely unsubstituted by fluorine atoms).

[0435] Cationic surfactants typically have positively charged hydrophilic portions, such as alkylated ammonium bromide and alkylated ammonium halide, and hydrophobic portions, such as long-chain fatty acids.

[0436] The proportion of hydrogen atoms bonded to carbon atoms in the aforementioned cationic surfactant that are replaced by fluorine atoms is preferably 50% or less, more preferably 25% or less, further preferably 10% or less, and most preferably 0% (completely unreplaced by fluorine atoms).

[0437] Anionic surfactants typically have hydrophilic moieties such as carboxylates, sulfonates, or sulfates, and hydrophobic moieties such as alkyl groups as long-chain hydrocarbon moieties.

[0438] The proportion of hydrogen atoms bonded to carbon atoms in the aforementioned anionic surfactant that are replaced by fluorine atoms is preferably 50% or less, more preferably 25% or less, further preferably 10% or less, and most preferably 0% (completely unreplaced by fluorine atoms).

[0439] Nonionic surfactants typically do not contain charged groups and have a hydrophobic portion that is a long-chain hydrocarbon. The hydrophilic portion of nonionic surfactants contains water-soluble functional groups such as ethylene ether chains derived from the polymerization of ethylene oxide.

[0440] The nonionic surfactants described above preferably have a fluorine atom substitution ratio of 50% or less for hydrogen atoms bonded to carbon atoms, more preferably 25% or less, further preferably 10% or less, and most preferably 0% (completely unsubstituted by fluorine atoms).

[0441] Other compounds with surface-active properties include anionic surfactants represented by RLM (where R is a straight-chain or branched alkyl group with or without substituents, or a cyclic alkyl group with or without substituents, having or without substituents, having 3 or more carbon atoms; in the case of 3 or more carbon atoms, it may contain monovalent or divalent heterocycles, or may form a ring; L is -ArSO3-, -SO3-, -SO4-, -PO3-, or -COO-, M is H, a metal atom, NR...). 5 4(R 5 They can be the same or different, and can be H or an organic group (preferably a fluorine-free organic group), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. -ArSO3- is an aryl sulfonate. R 5 Preferably, it is an organic group with H or 1 to 10 carbon atoms, more preferably an organic group with H or 1 to 4 carbon atoms.

[0442] Specifically, examples include lauryl acids, which are composed of CH3-(CH2). n The substance is represented by -LM (where n is an integer from 6 to 17. L and M are the same as above).

[0443] Alternatively, a mixture of substances in which R is an alkyl group having 12 to 16 carbon atoms and LM is a sulfate or sodium dodecyl sulfate (SDS) can be used.

[0444] Other compounds with surface active energy can also be cited as examples of those derived from R. 6 (-LM)2 represents an anionic surfactant (where R is an anionic surfactant). 6 It is a straight-chain or branched alkylene group with one or more carbon atoms, with or without substituents, or a cyclic alkylene group with three or more carbon atoms, with or without substituents. When there are three or more carbon atoms, it may contain monovalent or divalent heterocycles, or it may form a ring. L is -ArSO3-, -SO3-, -SO4-, -PO3-, or -COO-, and M is H, a metal atom, or NR. 5 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 5 It is H or an organic group (preferably a fluorine-free organic group), and -ArSO3- is an aryl sulfonate.

[0445] Other compounds with surface active energy can also be cited as examples of those derived from R. 7 (-LM)3 represents an anionic surfactant (where R is an anionic surfactant). 7 It is a straight-chain or branched alkyne group with one or more carbon atoms, with or without substituents, or a cyclic alkyne group with three or more carbon atoms, with or without substituents. When there are three or more carbon atoms, it may contain monovalent or divalent heterocycles, or form a ring. L is -ArSO3-, -SO3-, -SO4-, -PO3-, or -COO-, and M is H, a metal atom, or NR. 5 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 5 It is an H or an organic group (preferably a fluorine-free organic group). -ArSO3- is an aryl sulfonate.

[0446] Examples of siloxane surfactants include those described in Silicon Surfactants, R.M.Hill, Marcel Dekker, Inc., ISBN: 0-8247-00104. The structure of a siloxane surfactant comprises a clearly defined hydrophobic and a hydrophilic moiety. The hydrophobic moiety contains one or more dialkylsiloxane units, where the substituents on the silicon atoms are entirely hydrocarbons.

[0447] When the carbon atom of the hydrocarbon group can be replaced by halogens such as fluorine, these siloxane surfactants can also be regarded as hydrocarbon surfactants in the sense that they are completely replaced by hydrogen atoms, that is, the monovalent substituent on the carbon atom of the hydrocarbon group is hydrogen.

[0448] The aforementioned siloxane surfactant preferably has a fluorine atom substitution ratio of 50% or less for hydrogen atoms bonded to carbon atoms, more preferably 25% or less, further preferably 10% or less, and most preferably 0% (completely unsubstituted by fluorine atoms).

[0449] Regarding siloxane-based surfactants, it is also disclosed in U.S. Patent No. 6,841,616.

[0450] As other compounds with surface-active properties, anionic hydrocarbon surfactants are preferred. The substances described above can be used as anionic hydrocarbon surfactants, and the following hydrocarbon surfactants are also preferred.

[0451] Examples of anionic hydrocarbon surfactants include, for instance, compounds (α) represented by the following formula (α):

[0452] (where R is in the formula) 100It is a monovalent organic group containing one or more carbon atoms (preferably a fluorine-free organic group). M is H, a metal atom, or NR. 101 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 101 It can be H or an organic group (preferably a fluorine-free organic group, which can be the same or different). As R 101 The organic group is preferably alkyl. As R 101 Preferably, H or an organic group having 1 to 10 carbon atoms is preferred, more preferably H or an organic group having 1 to 4 carbon atoms is preferred, and even more preferably H or an alkyl group having 1 to 4 carbon atoms is preferred.

[0453] From the perspective of surface activity energy, R 100 The number of carbon atoms is preferably 2 or more, more preferably 3 or more. Furthermore, from the perspective of water solubility, R... 100 The number of carbon atoms is preferably 29 or less, more preferably 23 or less.

[0454] Examples of metal atoms that can serve as M include alkali metals (Group 1) and alkaline earth metals (Group 2), with Na, K, or Li being preferred. For M, H, a metal atom, or NR are preferred. 101 4. More preferably, H, alkali metals (Group 1), alkaline earth metals (Group 2), or NR. 101 4. Further preferred materials include H, Na, K, Li or NH4, even more preferred materials include Na, K or NH4, particularly preferred materials include Na or NH4, and most preferred materials include NH4.

[0455] As for the aforementioned compound (α), examples can also be given by R. 102 -COOM represents an anionic surfactant (where R is an anionic surfactant). 102 It is a straight-chain or branched alkyl, alkenyl, alkylene, or alkenyl group with one or more carbon atoms, having or without substituents, or a cyclic alkyl, alkenyl, alkylene, or alkenyl group with or without substituents, having or without substituents, and may contain ether bonds. In the case of three or more carbon atoms, it may contain monovalent or divalent heterocycles, or may form a ring. (M is the same as above).

[0456] Specifically, examples include CH3-(CH2) n -COOM (where n is an integer from 2 to 28. M is the same as above) represents the substance.

[0457] In addition, as an anionic hydrocarbon surfactant, compounds (β) represented by the following formula (β) can also be cited as examples:

[0458] (where R is in the formula) 100It is a monovalent organic group containing one or more carbon atoms (preferably a fluorine-free organic group). M is H, a metal atom, or NR. 101 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, R 101 It can be H or an organic group (preferably a fluorine-free organic group, which can be the same or different). As R 101 The organic group is preferably alkyl. As R 101 Preferably, H or an organic group having 1 to 10 carbon atoms is preferred, more preferably H or an organic group having 1 to 4 carbon atoms is preferred, and even more preferably H or an alkyl group having 1 to 4 carbon atoms is preferred.

[0459] From the perspective of surface activity energy, R 100 The number of carbon atoms is preferably 2 or more, more preferably 3 or more. Furthermore, from the perspective of water solubility, R... 100 The number of carbon atoms is preferably 29 or less, more preferably 23 or less.

[0460] Examples of metal atoms that can serve as M include alkali metals (Group 1) and alkaline earth metals (Group 2), with Na, K, or Li being preferred. For M, H, a metal atom, or NR are preferred. 101 4. More preferably, H, alkali metals (Group 1), alkaline earth metals (Group 2), or NR. 101 4. Further preferred materials include H, Na, K, Li or NH4, even more preferred materials include Na, K or NH4, particularly preferred materials include Na or NH4, and most preferred materials include NH4.

[0461] As for the aforementioned compound (β), examples can also be derived from R. 102 -SO3M represents an anionic surfactant (where R is an anionic surfactant). 102 It is a straight-chain or branched alkyl, alkenyl, alkylene, or alkenyl group with one or more carbon atoms, having or without substituents, or a cyclic alkyl, alkenyl, alkylene, or alkenyl group with or without substituents, having or without substituents, and may contain ether bonds. In the case of three or more carbon atoms, it may contain monovalent or divalent heterocycles, or may form a ring. (M is the same as above).

[0462] Specifically, examples include CH3-(CH2) n The substance is represented by -SO3M (where n is an integer from 2 to 28. M is the same as above).

[0463] Compound I, represented by the following formula I, can also be cited as an anionic hydrocarbon surfactant:

[0464] (In the formula, R is a hydrophobic hydrocarbon moiety containing one or more saturated or unsaturated, acyclic or cyclic aliphatic groups. The total percentage of CH3 groups in the one or more aliphatic groups relative to the total percentage of CH3, CH2 and CH groups is at least about 70%, and the hydrophobic moiety does not contain siloxane units. Each X can be the same or different, representing the ionic hydrophilic moiety. Each Z can be the same or different, representing one or more counterions of the ionic hydrophilic moiety. n is 1 to 3).

[0465] Compound I exhibits low reactivity with polymerization initiators and / or the free radicals of the fluorinated polymers grown in the emulsion polymerization of fluorinated monomers.

[0466] Compound I preferably contains the substitution moiety shown in the following formula: [Chemistry 13]

[0467] (where Y) + (It can be hydrogen, ammonium, quaternary ammonium, nitrogen heterocycle, alkali metal or alkaline earth metal).

[0468] Compound I is preferably compound II as shown in formula II below: [Chemistry 14]

[0469] (where R is in the formula) 2’ and R 2’’’ Whether the groups are the same or different, they are saturated or unsaturated, acyclic or cyclic aliphatic groups having 4 to 16 carbon atoms, R 2’ and R 2’’’ The total percentage of CH3 groups relative to the total percentage of CH3, CH2, and CH groups is at least about 70%, or R 2’ and R 2’’’ They are mutually bonded and can form saturated or unsaturated aliphatic rings, which may contain ether or ester bonds. The total percentage of CH3 groups in the ring relative to the total percentage of CH3, CH2, and CH groups is at least about 70%. 1 It can be hydrogen, methoxy, ethoxy, or phenoxy. + (It can be hydrogen, ammonium, quaternary ammonium, nitrogen heterocycle, alkali metal or alkaline earth metal).

[0470] As compound II, the following compounds are preferred, for example.

[0471] [Chemistry 15]

[0472] Y in the above formula + It can be hydrogen, ammonium, or alkali metal.

[0473] Compound I is also preferably compound III as shown in formula III below: [Chemistry 16]

[0474] (where R is in the formula) 3 R 4’ and R 4’’ Whether the groups are the same or different, they are hydrogen or saturated or unsaturated, acyclic or cyclic aliphatic groups having 4 to 16 carbon atoms, R 3 R 4’ and R 4’’ The total percentage of CH3 in the groups relative to the total percentage of CH3, CH2, and CH groups is at least about 70%. Among them, R... 3 R 4’ and R 4’’ At least one of them is not hydrogen, R 4’ and R 4’’ In the case of hydrogen, R 3 Not hydrogen, R 3 In the case of hydrogen, R 4’ and R 4’’ Not hydrogen. Y + (It can be hydrogen, ammonium, quaternary ammonium, nitrogen heterocycle, alkali metal or alkaline earth metal).

[0475] As compound III, the following compounds are preferred, for example.

[0476] [Chemistry 17]

[0477] Y in the above formula + It can be hydrogen, ammonium, or alkali metal.

[0478] The polymer composition disclosed herein can be obtained even without using the aforementioned specific hydrocarbon surfactant by a manufacturing method including the following polymerization step: in the presence of a hydrocarbon surfactant and a polymerization initiator, in an aqueous medium with a pH of 4.0 or higher, only tetrafluoroethylene is polymerized, or tetrafluoroethylene and a modified monomer capable of copolymerizing with the aforementioned tetrafluoroethylene are polymerized, to obtain a TFE-based polymer.

[0479] Previously, polymerization processes used to manufacture TFE-based polymers employed acidic polymerization initiators, resulting in aqueous media with a pH less than 4.0. Through in-depth research, the present inventors unexpectedly discovered that by using an aqueous media with a pH of 4.0 or higher for polymerization, the stability of the polymerization is improved, enabling the production of high molecular weight TFE-based polymers.

[0480] In the above manufacturing method, tetrafluoroethylene is polymerized only in an aqueous medium with a pH of 4.0 or higher, or tetrafluoroethylene is polymerized with a modified monomer capable of copolymerizing with the aforementioned tetrafluoroethylene. A pH of 4.0 or higher is acceptable, preferably greater than 4.0, more preferably 4.5 or higher, further preferably 5.0 or higher, even more preferably 5.5 or higher, particularly preferably 6.0 or higher, especially preferably 6.5 or higher, especially preferably 7.0 or higher, especially preferably 7.5 or higher, and especially preferably 8.0 or higher. The upper limit of the pH is not particularly limited; for example, it can be 13.0 or lower. From the perspective of corrosion of the polymerization reactor, a pH of 12.0 or lower is preferred, more preferably 11.5 or lower, and even more preferably 11.0 or lower.

[0481] The pH value mentioned above can be measured using a pH meter.

[0482] The polymer composition disclosed herein can be obtained even without using the aforementioned specific hydrocarbon surfactant by a process comprising a polymerization step in an aqueous medium in the presence of an anionic hydrocarbon surfactant and a polymerization initiator, wherein tetrafluoroethylene is polymerized alone, or tetrafluoroethylene is polymerized with a modified monomer capable of copolymerizing with the aforementioned tetrafluoroethylene to obtain a TFE-based polymer, wherein the hydrocarbon surfactant comprises a salt of the hydrocarbon surfactant. In other words, at least a portion of the anionic hydrocarbon surfactant in the above polymerization step is in the form of a salt.

[0483] The authors conducted in-depth research and unexpectedly discovered that by using anionic hydrocarbon surfactants containing salts of anionic hydrocarbon surfactants, the stability of polymerization is improved, and TFE-based polymers with large molecular weights can be manufactured.

[0484] This is believed to be due to the increased water solubility of anionic surfactants containing salts, which readily exhibit emulsifying properties.

[0485] The aforementioned anionic hydrocarbon surfactants will be described later.

[0486] The presence of salts of the aforementioned anionic hydrocarbon surfactants can be confirmed by measuring their conductivity.

[0487] In the above manufacturing method, the concentration of the salt of the anionic hydrocarbon surfactant relative to the total mass of the anionic hydrocarbon surfactant is preferably 50% by mass, more preferably 60% by mass or more, further preferably 70% by mass or more, even more preferably 80% by mass or more, particularly more preferably 90% by mass or more, and especially preferably 95% by mass or more.

[0488] The proportion of the above-mentioned salts can be determined by the solution concentration and conductivity.

[0489] In the above manufacturing method, the hydrocarbon surfactant is more preferably a carboxylic acid type hydrocarbon surfactant. The above hydrocarbon surfactant is fluorine-free.

[0490] In the salts of anionic hydrocarbon surfactants, the cations that replace the hydrogen atoms of the acid (excluding the hydrogen atoms) are, for example, metal atoms, NR... y 4(R y The groups can be the same or different, and can be H or an organic group (preferably a fluorine-free organic group), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. The above R... y H or alkyl is preferred, H or alkyl with 1 to 10 carbon atoms is more preferred, and H or alkyl with 1 to 4 carbon atoms is even more preferred.

[0491] The aforementioned cations in the salts of anionic hydrocarbon surfactants are preferably metal atoms or NR atoms. y 4. More preferably NR y 4. Further optimize NH4.

[0492] Conductivity varies greatly with temperature. Therefore, a constant temperature bath is used to maintain the sample liquid temperature at 25°C, and the temperature of the pH meter cell is also kept constant before measuring conductivity.

[0493] The polymer composition disclosed herein can be suitably manufactured by a manufacturing method comprising an addition step of adding at least one of a decomposing agent selected from the group consisting of a free radical scavenger and a polymerization initiator. The addition step is performed in a step of emulsion polymerization in an aqueous medium. By adding a free radical scavenger or a decomposing agent of the polymerization initiator, the free radical concentration during polymerization can be adjusted. From the perspective of reducing the free radical concentration, a free radical scavenger is preferred.

[0494] As the aforementioned free radical scavengers, compounds that do not possess the ability to re-initiate after addition or chain transfer into the polymerization system are used. Specifically, compounds with the following functions are used: readily undergoing chain transfer reactions with primary or growth free radicals to generate stable free radicals that do not react with monomers; or readily undergoing addition reactions with primary or growth free radicals to generate stable free radicals.

[0495] The activity of substances commonly referred to as chain transfer agents is characterized by chain transfer constants and re-initiation efficiency. Among chain transfer agents, substances with a re-initiation efficiency of essentially 0% are called free radical scavengers.

[0496] The aforementioned free radical scavengers can also be described as compounds whose chain transfer constant with TFE at the polymerization temperature is greater than the polymerization rate constant, and whose re-initiation efficiency is substantially zero%. "Substantially zero re-initiation efficiency" means that the generated free radicals make the free radical scavenger a stable free radical.

[0497] Preferably, the compound is a compound with a chain transfer constant (Cs) with TFE at the polymerization temperature (= chain transfer rate constant (kc) / polymerization rate constant (kp)) greater than 0.1. More preferably, the chain transfer constant (Cs) of the above compound is 0.5 or more, further preferably 1.0 or more, even more preferably 5.0 or more, and particularly preferably 10 or more.

[0498] As the free radical scavenger described above in this disclosure, it is preferably selected from at least one of the following groups: aromatic hydroxyl compounds, aromatic amines, N,N-diethylhydroxylamine, quinone compounds, terpenes, thiocyanates, and copper chloride (CuCl2).

[0499] Examples of aromatic hydroxyl compounds include non-substituted phenols, polyphenols, salicylic acid, meta-salicylic acid or para-salicylic acid, gallic acid, naphthol, etc.

[0500] Examples of non-substituted phenols include o-nitrophenol, m-nitrophenol, or p-nitrophenol, o-aminophenol, m-aminophenol, or p-aminophenol, and p-nitrosophenol. Examples of polyphenols include catechol, resorcinol, hydroquinone, pyrogallol, pyrogallol, naphthol, and resorcinol.

[0501] Examples of aromatic amines include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, and benzidine.

[0502] Examples of the aforementioned quinone compounds include ortho-benzoquinone, meta-benzoquinone or para-benzoquinone, 1,4-naphthoquinone, alizarin, etc.

[0503] Examples of thiocyanates include ammonium thiocyanate (NH4SCN), potassium thiocyanate (KSCN), and sodium thiocyanate (NaSCN).

[0504] As the aforementioned free radical scavenger, aromatic hydroxyl compounds are preferred, non-substituted phenols or polyphenols are more preferred, and hydroquinone is even more preferred.

[0505] From the perspective of reducing the standard proportion, the amount of the aforementioned free radical scavenger added is preferably equivalent to 3 to 500% (molar basis) of the polymerization initiator concentration. More preferably, the lower limit is 5% (molar basis), further preferably 8% (molar basis), more preferably 10% (molar basis), even more preferably 15% (molar basis), particularly preferably 20% (molar basis), especially preferably 25% (molar basis), particularly preferably 30% (molar basis), and particularly preferably 35% (molar basis). More preferably, the upper limit is 400% (molar basis), further preferably 300% (molar basis), even more preferably 200% (molar basis), and especially preferably 100% (molar basis).

[0506] As a decomposing agent for the polymerization initiator, any compound capable of decomposing the polymerization initiator used is acceptable, and preferably at least one is selected from the group consisting of sulfites, bisulfites, bromates, diimides, diimine salts, oxalic acid, oxalates, copper salts, and iron salts. Examples of sulfites include sodium sulfite and ammonium sulfite. Examples of copper salts include copper(II), and examples of iron salts include ferric(II) sulfate.

[0507] The amount of the decomposing agent of the above-mentioned polymerization initiator added is in the range of 25% to 300% by mass relative to the amount of oxidant in the polymerization initiator (redox initiator group described later). Preferably, it is 25% to 150% by mass, more preferably 50% to 100% by mass.

[0508] From the perspective of reducing the standard proportion, the amount of decomposing agent added to the above-mentioned polymerization initiator is preferably equivalent to 3 to 500% (molar basis) of the polymerization initiator concentration. More preferably, the lower limit is 5% (molar basis), further preferably 8% (molar basis), further preferably 10% (molar basis), further preferably 13% (molar basis), and even more preferably 15% (molar basis). More preferably, the upper limit is 400% (molar basis), further preferably 300% (molar basis), even more preferably 200% (molar basis), and particularly preferably 100% (molar basis).

[0509] The TFE-based polymer, preferably formed in an aqueous medium, is added when the concentration of at least one of the group consisting of a free radical scavenger and a polymerization initiator is 5% by mass or more. More preferably, it is added when the concentration is 10% by mass or more.

[0510] Furthermore, it is preferable to add the TFE-based polymer formed in the aqueous medium when the concentration is 40% by mass or less. More preferably, it is added when the concentration is 35% by mass or less, and even more preferably, it is added when the concentration is 30% by mass or less.

[0511] The above-mentioned addition process can be a process of continuously adding at least one of the decomposing agents selected from the group consisting of free radical scavengers and polymerization initiators.

[0512] At least one of the decomposing agents selected from the group consisting of free radical scavengers and polymerization initiators is added continuously, for example, not all at once, but over time and without interruption or in batches.

[0513] The above polymerization process can further polymerize tetrafluoroethylene in the presence of a nucleating agent.

[0514] As the nucleating agent mentioned above, it is preferably selected from at least one of the group consisting of fluorinated polyethers, nonionic surfactants and chain transfer agents.

[0515] In this case, the above-mentioned polymerization process is preferably a process in which tetrafluoroethylene is polymerized in an aqueous medium in the presence of a hydrocarbon surfactant and the above-mentioned nucleating agent to obtain a TFE-based polymer.

[0516] As the aforementioned fluorinated polyether, perfluoropolyether is preferred.

[0517] The fluorinated polyethers described above preferably have repeating units as shown in formulas (1a) to (1d).

[0518]

[0519] (In equations (1a) to (1d), m and n are integers greater than or equal to 1).

[0520] As the aforementioned fluorinated polyether, a fluorinated polyether acid or a salt thereof is preferred. The fluorinated polyether acid is preferably a carboxylic acid, sulfonic acid, sulfonamide, or phosphonic acid, and more preferably a carboxylic acid. Among the fluorinated polyether acid or its salt, a salt of a fluorinated polyether acid is preferred, an ammonium salt of a fluorinated polyether acid is more preferred, and an ammonium salt of a fluorinated polyether carboxylic acid is even more preferred.

[0521] The aforementioned fluoropolyether acids or their salts can have any chain structure in which the oxygen atom in the molecular backbone is separated by a saturated fluorocarbon group having 1 to 3 carbon atoms. Two or more types of fluorocarbon groups can exist in the molecule.

[0522] As the above-mentioned fluoropolyether acid or its salt, the preferred compounds are those shown in the following formula or their salts: CF3-CF2-CF2-O(-CFCF3-CF2-O-) n CFCF3-COOH, CF3-CF2-CF2-O(-CF2-CF2-CF2-O-) n -CF2-CF2COOH, or HOOC-CF2-O(-CF2-CF2-O-)n-(-CF2-O-) m CF2COOH, (In the formula, m and n are the same as above).

[0523] These structures were studied by Kasai in J. Appl. Polymer Sci., 57, 797 (1995). As disclosed herein, such fluorinated polyethers may have carboxylic acid groups or their salts at one or both ends. Similarly, such fluorinated polyethers may have sulfonic acid or phosphonic acid groups or their salts at one or both ends. Furthermore, fluorinated polyethers with acid functional groups at both ends may have different groups at each end. Regarding monofunctional fluorinated polyethers, the other end of the molecule is usually perfluorinated, but may also contain hydrogen or chlorine atoms.

[0524] Fluorinated polyethers having acid groups at one or both ends have at least two ether oxygen atoms, preferably at least four ether oxygen atoms, and more preferably at least six ether oxygen atoms. Preferably, at least one of the fluorocarbon groups separating the ether oxygen atoms has two or three carbon atoms, more preferably at least two such fluorocarbon groups have two or three carbon atoms. More preferably, at least 50% of the fluorocarbon groups separating the ether oxygen atoms have two or three carbon atoms. Additionally, it is preferred that the fluorinated polyethers have at least 15 carbon atoms in total, for example, the minimum value of n or n+m in the repeating unit structure described above is at least 5. Two or more fluorinated polyethers having acid groups at one or both ends can be used in the methods based on this disclosure. Typically, fluorinated polyethers can contain two or more compounds in various proportions within a molecular weight range relative to the average molecular weight, unless special care is taken when manufacturing a single type of specific fluorinated polyether compound.

[0525] The aforementioned fluorinated polyethers preferably have a number-average molecular weight of 800 g / mol or higher. Fluorinated polyether acids or their salts may be difficult to disperse in aqueous media; therefore, their number-average molecular weight is preferably less than 6000 g / mol. More preferably, the number-average molecular weight of the fluorinated polyether acid or its salt is 800–3500 g / mol, and even more preferably 1000–2500 g / mol.

[0526] The amount of the above-mentioned fluorinated polyether relative to the aqueous medium is preferably 5 to 3000 ppm, more preferably 5 to 2000 ppm, further preferably 10 ppm, and further preferably 100 ppm.

[0527] For nonionic surfactants used as nucleating agents, examples of such nonionic surfactants can be cited, with fluorine-free nonionic surfactants being preferred. For instance, compounds represented by the following general formula (i) can be cited as examples of such nonionic surfactants:

[0528] (where R is in the formula) 3 A is a straight-chain or branched primary or secondary alkyl group with 8 to 18 carbon atoms. 1 (It consists of polyoxyethylene chains).

[0529] R 3 The number of carbon atoms is preferably 10 to 16, more preferably 12 to 16. 3 When the number of carbon atoms is 18 or less, it is difficult to obtain good dispersion stability in aqueous dispersions. Additionally, R... 3 When the number of carbon atoms is greater than 18, the flow temperature is high, making it difficult to process. R 3 When the number of carbon atoms is less than 8, the surface tension of the aqueous dispersion increases, and its permeability and wettability are easily reduced.

[0530] Polyoxyethylene chains can be composed of ethylene oxide and propylene oxide. A polyoxyethylene chain consisting of an average repeating number of 5–20 for vinyl oxide groups and an average repeating number of 0–2 for propylene oxide groups, and containing hydrophilic groups, is described. The number of ethylene oxide units can include either a commonly provided broad or narrow unimodal distribution, or a broader or bimodal distribution obtained through blending. When the average repeating number of propylene oxide groups is greater than 0, the vinyl oxide and propylene oxide groups in the polyoxyethylene chain can be arranged in block or random arrangements.

[0531] From the perspective of viscosity and stability of aqueous dispersions, polyoxyethylene chains composed of an average repeat number of 7 to 12 for vinyl oxides and an average repeat number of 0 to 2 for propylene oxides are preferred. In particular, A... 1 Having an average of 0.5 to 1.5% propylene oxide groups results in good low foaming properties and is therefore preferred.

[0532] More preferably R 3 The formula is (R')(R'')HC-, where R' and R'' are the same or different straight-chain, branched, or cyclic alkyl groups, and the total number of carbon atoms is at least 5, preferably 7 to 17. Preferably, at least one of R' or R'' is a branched or cyclic hydrocarbon group.

[0533] As a specific example of the aforementioned polyoxyethylene alkyl ethers, C can be cited. 13 H 27 -O-(C2H4O) 10 -H, C 12 H 25 -O-(C2H4O) 10 -H, C 10 H 21 CH(CH3)CH2-O-(C2H4O)9-H,C 13 H 27 -O-(C2H4O)9-(CH(CH3)CH2O)-H, C16 H 33 -O-(C2H4O) 10 -H, HC(C5H) 11 (C7H) 15 Examples of commercially available polyoxyethylene alkyl ethers include Genapol X080 (manufactured by Clariant), the Noigen TDS series (manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.) with Noigen TDS-80 as an example, the Leocol TD series (manufactured by LION) with Leocol TD-90 as an example, the LIONOL TD series (manufactured by LION) with registered trademark, the T-Det A series (manufactured by Harcros Chemicals) with T-Det A138 as an example, and the TERGITOL 15S series (manufactured by Dow).

[0534] The aforementioned nonionic surfactants are preferably ethoxylated derivatives of 2,6,8-trimethyl-4-nonanol having an average of about 4 to about 18 ethylene oxide units, ethoxylated derivatives of 2,6,8-trimethyl-4-nonanol having an average of about 6 to about 12 ethylene oxide units, or mixtures thereof. Such nonionic surfactants are also commercially available, for example, TERGITOL TMN-6, TERGITOL TMN-10, and TERGITOL TMN-100X (all product names, manufactured by Dow Chemical).

[0535] In addition, the hydrophobic group of a nonionic surfactant can be any one of alkylphenol, straight-chain alkyl, and branched-chain alkyl.

[0536] For example, as a nonionic compound of polyoxyethylene alkylphenyl ether, compounds represented by the following general formula (ii) can be cited:

[0537] (where R is in the formula) 4 A is a straight-chain or branched primary or secondary alkyl group with 4 to 12 carbon atoms. 2 (It is a polyoxyethylene alkylphenyl ether chain). As a nonionic compound of polyoxyethylene alkylphenyl ether, examples include Triton X-100 (a registered trademark, manufactured by Dow Chemical Company).

[0538] Other nonionic surfactants include difunctional block copolymers supplied by BASF under the Pluronic (registered trademark) R series, tridecyl alcohol alkoxylates supplied by BASF Corporation under the Iconol (registered trademark) TDA series, hydrocarbon-containing siloxane surfactants, and preferably hydrocarbon surfactants. Here, if the hydrocarbon group can be replaced by halogens such as fluorine, it can be completely replaced by hydrogen atoms. Thus, these siloxane surfactants can also be regarded as hydrocarbon surfactants, that is, the monovalent substituent on the hydrocarbon group is hydrogen.

[0539] In addition to the specific hydrocarbon-based surfactants and other compounds with surface-active properties as desired, additives for stabilizing the compounds may also be used in the above manufacturing method. Examples of such additives include buffers, pH adjusters, stabilizing agents, and dispersing stabilizers.

[0540] Preferred stabilizing agents include paraffin wax, fluorinated oils, fluorinated solvents, and silicone oils. One stabilizing agent can be used alone or in combination of two or more. Paraffin wax is more preferred. Paraffin wax can be liquid, semi-solid, or solid at room temperature, and is preferably a saturated hydrocarbon with 12 or more carbon atoms. The melting point of paraffin wax is typically preferred to be 40–65°C, more preferably 50–65°C.

[0541] The amount of stabilizing agent used is preferably 0.1 to 12% by mass, more preferably 0.1 to 8% by mass, based on the mass of the aqueous medium used. The stabilizing agent preferably has sufficient hydrophobicity and completely separates from the aqueous emulsion of the TFE-based polymer after the emulsion polymerization of TFE without becoming a contaminating component.

[0542] In the above manufacturing method, emulsion polymerization can be carried out as follows: an aqueous medium, the aforementioned hydrocarbon-based surfactant, monomer, and other additives as needed are added to a polymerization reactor; the contents of the reactor are stirred; the reactor is maintained at a specified polymerization temperature; then a specified amount of polymerization initiator is added to initiate the polymerization reaction. After the polymerization reaction begins, monomers, polymerization initiators, chain transfer agents, and the aforementioned surfactants can be added as needed. The aforementioned hydrocarbon-based surfactant can be added after the polymerization reaction begins.

[0543] In the above emulsion polymerization, the polymerization temperature and polymerization pressure are appropriately determined according to the type of monomer used, the molecular weight of the target TFE-based polymer, and the reaction rate. Typically, the polymerization temperature is 5°C to 150°C, preferably 10°C or higher, more preferably 30°C or higher, and even more preferably 50°C or higher. Furthermore, it is more preferably 120°C or lower, and even more preferably 100°C or lower.

[0544] The polymerization pressure is 0.05 MPaG to 10 MPaG. More preferably, the polymerization pressure is 0.3 MPaG or more, and even more preferably, 0.5 MPaG or more. Furthermore, more preferably, it is 5.0 MPaG or less, and even more preferably, 3.0 MPaG or less.

[0545] In particular, from the perspective of increasing yield, it is preferred to be 1.0 MPaG or more, more preferably 1.2 MPaG or more, further preferably 1.5 MPaG or more, even more preferably 1.8 MPaG or more, and especially preferably 2.0 MPaG or more.

[0546] In the above emulsion polymerization, the hydrocarbon surfactant is preferably added when the concentration of the TFE-based polymer formed in the aqueous medium is less than 0.60% by mass. More preferably, the concentration is 0.50% by mass or less, further preferably 0.36% by mass or less, even more preferably 0.30% by mass or less, particularly more preferably 0.20% by mass or less, especially preferably 0.10% by mass or less, and most preferably added at the start of polymerization. The above concentrations are the total concentrations relative to the aqueous medium and the TFE-based polymer.

[0547] Furthermore, in the above-mentioned emulsion polymerization, the amount of hydrocarbon surfactant at the start of polymerization is preferably 1 ppm or more relative to the aqueous medium. The amount of hydrocarbon surfactant at the start of polymerization is preferably 10 ppm or more, more preferably 50 ppm or more, further preferably 100 ppm or more, and even more preferably 200 ppm or more. There is no particular upper limit, but for example, 100,000 ppm is preferred, and 50,000 ppm is more preferred. By using the above-mentioned range of hydrocarbon surfactant at the start of polymerization, an aqueous dispersion with a smaller average primary particle size and better stability can be obtained.

[0548] As the polymerization initiator described above, there are no particular limitations as long as free radicals can be generated within the aforementioned polymerization temperature range; known oil-soluble and / or water-soluble polymerization initiators can be used. Furthermore, it can be combined with reducing agents to initiate polymerization in a redox manner. The concentration of the polymerization initiator is appropriately determined based on the type of monomer, the molecular weight of the target TFE-based polymer, and the reaction rate.

[0549] Oil-soluble free radical polymerization initiators or water-soluble free radical polymerization initiators can be used as polymerization initiators.

[0550] As an oil-soluble free radical polymerization initiator, it can be a known oil-soluble peroxide, such as the following peroxides as representative substances: diisopropyl peroxide, disec-butyl peroxide, and other dialkyl peroxide esters; tert-butyl peroxide, tert-butyl peroxyisobutyrate, and other peroxide esters; dialkyl peroxides such as di-tert-butyl peroxide, etc.

[0551] As a water-soluble free radical polymerization initiator, it can be a known water-soluble peroxide, such as ammonium salts, potassium salts, sodium salts of persulfate, perboric acid, perchloric acid, superphosphoric acid, and percarbonate, as well as tert-butyl maleate peroxide and tert-butyl hydroperoxide. It can also contain reducing agents such as sulfites and sulfites, and their amount relative to the peroxide can be 0.1 to 20 times.

[0552] For example, when polymerization is carried out at low temperatures below 30°C, a redox initiator combining an oxidant and a reducing agent is preferred as the polymerization initiator. Examples of oxidants include persulfates, organic peroxides, potassium permanganate, manganese triacetate, cerium ammonium nitrate, and bromates. Examples of reducing agents include sulfites, bisulfites, bromates, diimides, and oxalic acid. Examples of persulfates include ammonium persulfate and potassium persulfate. Examples of sulfites include sodium sulfite and ammonium sulfite. To improve the decomposition rate of the initiator, it is also preferable to add copper or iron salts to the combination of redox initiators. Examples of copper salts include copper(II) sulfate, and examples of iron salts include ferric(II) sulfate.

[0553] As the above-mentioned redox initiator, the preferred oxidant is permanganic acid or its salt, persulfate, manganese triacetate, cerium(IV) salt, or bromic acid or its salt, and the preferred reducing agent is dicarboxylic acid or its salt, or diimine.

[0554] More preferably, the oxidant is permanganic acid or its salt, persulfate, or bromic acid or its salt, and the reducing agent is dicarboxylic acid or its salt.

[0555] Examples of redox initiators include combinations such as potassium permanganate / oxalic acid, potassium permanganate / ammonium oxalate, manganese triacetate / oxalic acid, manganese triacetate / ammonium oxalate, cerium ammonium nitrate / oxalic acid, and cerium ammonium nitrate / ammonium oxalate.

[0556] When using a redox initiator, either the oxidant or the reducing agent can be added to the polymerization reactor beforehand, followed by the addition of the other continuously or intermittently to initiate polymerization. For example, when using potassium permanganate / ammonium oxalate, it is preferable to add ammonium oxalate to the polymerization reactor and then continuously add potassium permanganate thereto.

[0557] It should be noted that when the redox initiator in this specification is designated as "potassium permanganate / ammonium oxalate," it refers to the combination of potassium permanganate and ammonium oxalate. The same applies to other compounds.

[0558] As the aforementioned redox initiator, it is preferable to use an oxidizing agent or a reducing agent that can set the pH of the aqueous redox initiator solution to 4.0 or higher. The aforementioned aqueous redox initiator solution refers to an aqueous solution with a concentration of 0.50% by mass of the oxidizing agent or a 0.50% by mass of the reducing agent.

[0559] That is, at least one of the 0.50% by mass aqueous solution of the oxidant and the 0.50% by mass aqueous solution of the reducing agent has a pH of 4.0 or higher, and preferably both the 0.50% by mass aqueous solution of the oxidant and the 0.50% by mass aqueous solution of the reducing agent have a pH of 4.0 or higher.

[0560] The pH of the above-mentioned redox initiator aqueous solution (0.50% by mass aqueous solution of oxidant or 0.50% by mass aqueous solution of reductant) is more preferably 5.0 or above, further preferably 5.5 or above, and particularly preferably 6.0 or above.

[0561] The aforementioned redox initiator is particularly preferably a combination of an oxidant as a salt and a reducing agent as a salt.

[0562] For example, the oxidizing agent of the above-mentioned salt is more preferably at least one selected from the group consisting of persulfate, permanganate, cerium(IV) salt and bromate, and is further preferably permanganate, particularly preferably potassium permanganate.

[0563] Furthermore, the reducing agent for the aforementioned salt is more preferably at least one selected from the group consisting of oxalate, malonate, succinate, glutarate and bromate, and is even more preferably oxalate, particularly preferably ammonium oxalate.

[0564] Specifically, the redox initiator is preferably selected from at least one of the group consisting of potassium permanganate / ammonium oxalate, potassium bromate / ammonium sulfite, manganese triacetate / ammonium oxalate, and cerium ammonium nitrate / ammonium oxalate, and more preferably from at least one of the group consisting of potassium permanganate / ammonium oxalate, potassium bromate / ammonium sulfite, and cerium ammonium nitrate / ammonium oxalate.

[0565] By using a redox initiator in the above polymerization process, the molecular weight of the obtained TFE-based polymer can be increased. Therefore, the SSG (sulfate-saturated group) can be reduced, and a stretchable polymer can be produced.

[0566] Furthermore, by using a redox initiator in the above polymerization process, the number of TFE-based polymer particles generated in the aqueous dispersion can be increased. Additionally, the yield of TFE-based polymers can be improved.

[0567] When using a redox initiator, the oxidant and reductant can be added all at once at the beginning of polymerization, or the reductant can be added all at once at the beginning of polymerization and the oxidant can be added continuously, or both the oxidant and reductant can be added continuously.

[0568] When using a redox initiator as a polymerization initiator, the amount of oxidant added is preferably 5 to 10,000 ppm, more preferably 10 to 1,000 ppm, relative to the aqueous medium, and the amount of reductant added is preferably 5 to 10,000 ppm, more preferably 10 to 1,000 ppm.

[0569] Furthermore, when a redox initiator is used in the above polymerization process, the polymerization temperature is preferably 100°C or below, more preferably 95°C or below, and even more preferably 90°C or below. Additionally, it is preferably 10°C or above, more preferably 20°C or above, and even more preferably 30°C or above.

[0570] The amount of polymerization initiator added is not particularly limited, as long as it is an amount that will not significantly reduce the polymerization rate when added once, gradually, or continuously at the beginning of polymerization (e.g., a concentration of a few ppm relative to water). The upper limit is the range where the heat of polymerization can be deheated from the apparatus surface while simultaneously increasing the reaction temperature; a more preferred upper limit is the range where the heat of polymerization can be removed from the apparatus surface. More specifically, for example, it is preferably 1 ppm or more relative to an aqueous medium, more preferably 10 ppm or more, and even more preferably 50 ppm or more. Furthermore, it is preferably 100,000 ppm or less, more preferably 10,000 ppm or less, and even more preferably 5,000 ppm or less.

[0571] The aforementioned aqueous medium refers to the reaction medium that enables polymerization, which is a liquid containing water. There are no particular limitations on the aqueous medium as long as it contains water; it can contain water and non-fluorinated organic solvents such as alcohols, ethers, and ketones, and / or fluorinated organic solvents with a boiling point below 40°C.

[0572] In the above emulsion polymerization, the polymerization rate and molecular weight can be adjusted by adding a known chain transfer agent according to the purpose.

[0573] Examples of chain transfer agents include esters such as dimethyl malonate, diethyl malonate, methyl acetate, ethyl acetate, butyl acetate, and dimethyl succinate, as well as various halogenated hydrocarbons such as isopentane, methane, ethane, propane, isobutane, methanol, ethanol, isopropanol, acetone, various thiols, carbon tetrachloride, and cyclohexane.

[0574] Bromine or iodine compounds can be used as chain transfer agents. For example, a polymerization method using bromine or iodine compounds can be described as the polymerization of fluorine monomers in an aqueous medium under substantially anaerobic conditions in the presence of bromine or iodine compounds (iodine transfer polymerization). Representative examples of the bromine or iodine compounds used include compounds represented by the following general formula:

[0575] (In the formula, x and y are integers from 0 to 2 and satisfy 1≤x+y≤2, R) a It can be a saturated or unsaturated fluorocarbon or chlorofluorocarbon group with 1 to 16 carbon atoms, or a hydrocarbon group with 1 to 3 carbon atoms, and may contain oxygen atoms. By using bromine or iodine compounds, iodine or bromine is introduced into the polymer to function as a crosslinking point.

[0576] Examples of iodine compounds include 1,3-diiodoperfluoropropane, 2-iodoperfluoropropane, 1,3-diiodo-2-chloroperfluoropropane, 1,4-diiodoperfluorobutane, 1,5-diiodo-2,4-dichloroperfluoropentane, 1,6-diiodoperfluorohexane, 1,8-diiodoperfluorooctane, 1,12-diiodoperfluorododecane, 1,16-diiodoperfluorohexadecane, diiodomethane, 1,2-diiodoethane, 1,3-diiodopropane, CF₂Br₂, BrCF₂CF₂Br, CF₃CFBrCF₂Br, CFClBr₂, and Br. CF2CFClBr, CFBrClCFClBr, BrCF2CF2CF2Br, BrCF2CFBrOCF3, 1-bromo-2-iodoperfluoroethane, 1-bromo-3-iodoperfluoropropane, 1-bromo-4-iodoperfluorobutane, 2-bromo-3-iodoperfluorobutane, 3-bromo-4-iodoperfluoro-1-butene, 2-bromo-4-iodoperfluoro-1-butene, monoiodomonobromo-substituted derivatives of benzene, diiodomonobromo-substituted derivatives, and (2-iodoethyl) and (2-bromoethyl)-substituted derivatives, etc. These compounds can be used alone or in combination with each other.

[0577] Among these, 1,4-diiodoperfluorobutane, 1,6-diiodoperfluorohexane, and 2-iodoperfluoropropane are preferred in terms of polymerization reactivity, crosslinking reactivity, and ease of acquisition.

[0578] The amount of the chain transfer agent used is typically 1 to 50,000 ppm, preferably 1 to 20,000 ppm, relative to the total amount of fluorine monomer supplied.

[0579] The chain transfer agent described above can be added to the reaction vessel all at once before the start of polymerization, or all at once after the start of polymerization, or added separately in multiple stages during polymerization, or added continuously during polymerization.

[0580] An aqueous dispersion of a TFE-based polymer can be obtained through the emulsion polymerization described above. This aqueous dispersion typically comprises a TFE-based polymer, compound (1) and / or (2), and an aqueous medium. The concentration of the solids component in the aqueous dispersion is not limited, and can be, for example, 1.0 to 70% by mass. The concentration of the solids component is preferably 8.0% by mass or more, more preferably 10.0% by mass or more, and preferably 60.0% by mass or less, more preferably 50.0% by mass or less.

[0581] In the above manufacturing method, the amount of adhesion relative to the final TFE-based polymer is preferably 3.0% by mass or less, more preferably 2.0% by mass or less, even more preferably 1.0% by mass or less, more preferably 0.8% by mass or less, even more preferably 0.7% by mass or less, and particularly preferably 0.6% by mass or less.

[0582] The aqueous dispersion or powder of the thermoplastic polymer in step (A) can be manufactured by known methods such as suspension polymerization, emulsion polymerization, and solution polymerization. Among these methods, suspension polymerization and emulsion polymerization are preferred, and emulsion polymerization is more preferred.

[0583] For precipitation in process (B), it can be done by known methods.

[0584] When precipitating aqueous dispersions of TFE-based polymers, water is typically used to dilute the aqueous dispersion obtained through polymerization, such as polymer emulsions, to a polymer concentration of 10–25% by mass (preferably 10–20% by mass). Depending on the situation, the pH is adjusted to neutral or alkaline, and then the mixture is stirred more vigorously than during the reaction in a vessel equipped with a stirrer. This precipitation can be carried out while stirring is applied, with the addition of water-soluble organic compounds such as methanol and acetone, inorganic salts such as potassium nitrate and ammonium carbonate, or inorganic acids such as hydrochloric acid, sulfuric acid, and nitric acid as precipitating agents. The precipitation can also be carried out continuously using an online mixer or similar equipment.

[0585] The drying (heat treatment) in step (C) is typically carried out using methods such as vacuum, high frequency, or hot air, while keeping the moist powder in a state where it does not flow much, preferably a static state. Friction between powders, especially at high temperatures, usually has an adverse effect on fine-powdered fibrillable polymers. This is because particles composed of such fibrillable polymers have the property of easily fibrillating even under small shear forces, thus losing their originally stable particle structure.

[0586] From the perspective of being able to remove moisture and fluorine-containing compounds more efficiently, the drying temperature in step (C) is preferably 130°C or higher, more preferably 140°C or higher, even more preferably 150°C or higher, even more preferably 160°C or higher, even more preferably 180°C or higher, even more preferably 200°C or higher, particularly preferably 220°C or higher, and preferably 300°C or lower, more preferably 280°C or lower, and even more preferably 250°C or lower.

[0587] When using a vacuum, drying at low temperatures such as above 60°C, above 70°C, above 80°C, or above 90°C is preferred.

[0588] From the perspective of more efficient removal of moisture and fluorine-containing compounds, the drying time in step (C) is preferably 2 hours or more, more preferably 5 hours or more, further preferably 10 hours or more, and even more preferably 15 hours or more. There is no particular upper limit, but for example, 100 hours is preferred, more preferably 50 hours, and even more preferably 30 hours.

[0589] From the perspective of more efficient removal of moisture and fluorine-containing compounds, the air velocity in step (C) is preferably 0.01 m / s or more, more preferably 0.03 m / s or more, even more preferably 0.05 m / s or more, and even more preferably 0.1 m / s or more. Furthermore, from the perspective of suppressing powder scattering, it is preferably 50 m / s or less, more preferably 30 m / s or less, and even more preferably 10 m / s or less.

[0590] The drying in step (C) can be carried out using an electric furnace or a steam furnace. For example, a parallel-flow box furnace, a pneumatic box furnace, a pneumatic conveyor furnace, a belt furnace, a radiant conveyor furnace, a fluidized bed furnace, a vacuum furnace, a stirred furnace, an airflow furnace, a hot air circulation furnace, or a corresponding steam furnace can be used. From the perspective of more efficient removal of moisture and fluorine-containing compounds, a parallel-flow box furnace, a pneumatic box furnace, a pneumatic conveyor furnace, a belt furnace, a fluidized bed furnace, a hot air circulation furnace, or a corresponding steam furnace is preferred.

[0591] From the perspective of more efficient removal of moisture and fluorine compounds, the drying in step (C) is preferably performed by placing the aforementioned moist powder in a container with a breathable bottom and / or sides. The container with a breathable bottom and / or sides need only be able to withstand the aforementioned drying temperature, and is preferably made of metal such as stainless steel.

[0592] As a container with breathable bottom and / or sides, a tray (basin) with breathable bottom and / or sides is preferred, and a tray with a mesh bottom and / or sides is more preferably made of a mesh material (mesh tray).

[0593] The aforementioned mesh is preferably either woven mesh or perforated mesh.

[0594] The mesh size of the aforementioned mesh is preferably 2000 μm or less (10 mesh or more according to ASTM standards), more preferably 595 μm or less (30 mesh or more), further preferably 297 μm or less (50 mesh or more), even more preferably 177 μm or less (80 mesh or more), particularly preferably 149 μm or less (100 mesh or more), and especially preferably 74 μm or less (200 mesh or more). Additionally, a mesh size of 25 μm or more (500 mesh or less) is preferred.

[0595] For example, when the aforementioned mesh is used as a woven net, weaving methods include plain weave, twill weave, flat overlay weave, and twill overlay weave.

[0596] When the aforementioned mesh is a perforated mesh, the open area ratio is preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more. Furthermore, it is preferably 95% or less.

[0597] In step (C), from the perspective of more efficient removal of moisture and fluoride compounds, the preferred amount of the aforementioned moist powder is 10 g / cm³. 2 The following, or more preferably, is 8g / cm 2 The following, and more preferably 5g / cm 2 The following, especially preferred, is 3g / cm³. 2 Furthermore, 0.01 g / cm³ is preferred. 2 The above, and more preferably, is 0.05 g / cm³. 2 The above, and more preferably 0.1 g / cm 2 above.

[0598] Regarding the moisture content of the wet powder dried in step (C), from the perspective of being able to remove moisture and fluorine-containing compounds more efficiently, it is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, and preferably 150% by mass or less, more preferably 100% by mass or less, relative to the aforementioned wet powder.

[0599] In addition, the polymer composition disclosed herein can also be suitably manufactured by a manufacturing method including step (D) of mixing powder of a fibrillating polymer with powder of a thermoplastic polymer.

[0600] The powder of the fibrillating polymer in step (D) can be manufactured, for example, by precipitating and drying an aqueous dispersion of the fibrillating polymer obtained from emulsion polymerization. This aqueous dispersion can be manufactured using the same method as the aqueous dispersion of the fibrillating polymer obtained from emulsion polymerization in step (A). The precipitation and drying can be performed using the same methods as in steps (B) and (C).

[0601] The thermoplastic polymer powder in step (D) can be manufactured using the same method as the thermoplastic polymer powder in step (A).

[0602] The mixing in step (D) can be carried out by dry mixing. From the perspective of improving powder flowability, in order to suppress fibrillation of fibrillating polymers, a mixing method with low shear force is preferred. For example, mixing methods that do not use stirring blades, such as air-jet mixing or mixing using a V-type mixer, are preferred.

[0603] The polymer composition disclosed herein is used as an adhesive for electrochemical devices. In the aforementioned adhesive for electrochemical devices, the polymer composition of this disclosure may be used alone or in combination with other materials, but it is preferred to use the polymer composition of this disclosure substantially alone, and more preferably, to use it alone. It should be noted that using the polymer composition of this disclosure substantially alone means using it in such a manner that the amount of the polymer composition in the adhesive for electrochemical devices falls within the range described below.

[0604] This disclosure also provides an adhesive for electrochemical devices (hereinafter also referred to as the adhesive (1) of this disclosure), which is an adhesive for electrochemical devices substantially composed only of a polymer composition, wherein the polymer composition comprises a fibrillated polymer, a thermoplastic polymer, and at least one compound selected from the group consisting of a compound represented by the following general formula (1) and a compound represented by the following general formula (2).

[0605] General formula (1): (H-(CF2)) m-1 -COO) p M 1

[0606] (In the formula, m ranges from 4 to 20. M) 1 For H, metal atoms, NR 5 4(R 5 They can be the same or different (either H or an organic group with 1 to 10 carbon atoms), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. p is 1 or 2).

[0607] General formula (2): (H-(CF2)) n -SO3) qM 2

[0608] (In the formula, n is 4 to 20. M) 2 For H, metal atoms, NR 5 4(R 5 (Same as above), imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents. q is 1 or 2).

[0609] This disclosure also provides an adhesive for electrochemical devices (hereinafter also referred to as the adhesive (2) of this disclosure), which is an adhesive for electrochemical devices that is substantially composed only of a polymer composition, wherein the polymer composition comprises a fibrillated polymer and a thermoplastic polymer, and the thermal instability index (TII) of the fibrillated polymer is 10 or more.

[0610] In this specification, unless otherwise specified, the adhesives (1) to (2) of this disclosure are collectively referred to as "the adhesives of this disclosure".

[0611] The adhesive disclosed herein, by comprising a specific polymer composition, can improve the coulombic efficiency of electrochemical devices. Furthermore, even small amounts can be used to produce adhesive sheets. Additionally, since adhesive sheets with excellent adhesion to substrates such as metal foils can be obtained, the adhesive sheets can be bonded to the substrate even without increasing the density of the adhesive layer (even without compaction), enabling processing under a wider range of molding conditions.

[0612] When the binder of this disclosure is made into powder form, its flowability can also be improved.

[0613] Furthermore, the binder disclosed herein can be used in a dry manner, thus eliminating the need for large amounts of dispersion media such as water or organic solvents. This allows for a wide selection of electrode active materials and solid electrolytes, which is advantageous in the production process. Additionally, it reduces the number of steps and costs associated with using dispersion media.

[0614] Furthermore, the adhesive disclosed herein exhibits excellent adhesion to active substances and electrolytes, thus enabling a reduction in the amount used.

[0615] As the polymer composition in the adhesive of this disclosure, the same polymer composition as the polymer composition of this disclosure described above can be used, and preferably in the same manner.

[0616] The adhesive disclosed herein is substantially composed solely of the aforementioned polymer composition. Therefore, the effects of the aforementioned polymer composition can be significantly utilized. "Substantially composed solely of the aforementioned polymer composition" means that the content of the aforementioned polymer composition relative to the adhesive is 95.0% by mass or more.

[0617] The content of the polymer composition relative to the binder is preferably 98.0% by mass or more, more preferably 99.0% by mass or more, even more preferably 99.5% by mass or more, particularly preferably 99.9% by mass or more, and most preferably 99.95% by mass or more.

[0618] The adhesive disclosed herein is preferably composed solely of the polymer composition described above.

[0619] The adhesive disclosed herein is preferably substantially free of organic solvents. This reduces the steps and costs associated with using organic solvents. "Substantially free of organic solvents" means that the organic solvent content in the adhesive is 5% by mass or less.

[0620] The organic solvent content is preferably 3% by mass or less, more preferably 1% by mass or less, further preferably 0.1% by mass or less, even more preferably 0.01% by mass or less, and particularly preferably 0.001% by mass or less.

[0621] The binder disclosed herein is preferably in the form of a powder, but may also be in other forms, such as a dispersion or a molded body.

[0622] The binder disclosed herein is used in electrochemical devices such as batteries and capacitors.

[0623] Examples of batteries include secondary batteries such as lithium-ion batteries.

[0624] There are no particular limitations on the capacitor, but electrochemical capacitors are preferred. Examples of electrochemical capacitors include double-layer capacitors, hybrid capacitors, and redox capacitors. Examples of hybrid capacitors include sodium-ion capacitors, lithium-ion capacitors, and magnesium-ion capacitors. Among these, double-layer capacitors are particularly preferred.

[0625] The adhesive disclosed herein is suitable for use as a battery adhesive, and is particularly suitable for use as an adhesive for secondary batteries such as lithium-ion batteries.

[0626] The binder disclosed herein can be used to manufacture electrochemical device components, preferably battery components.

[0627] The binder disclosed herein is particularly suitable for use as an electrode binder.

[0628] In addition, the binder disclosed herein can also be used as a binder in the solid electrolyte layer of a solid secondary battery.

[0629] This disclosure also provides an electrode binder comprising the polymer composition or binder and electrode active material of this disclosure described above. Using the electrode binder of this disclosure improves the coulombic efficiency of the electrochemical device. Furthermore, even with a small amount of binder, the electrode active material can be retained, allowing for the addition of more active materials, conductive additives, and other materials that enhance the characteristics of the electrochemical device. Additionally, since a binder sheet with excellent adhesion to substrates such as metal foil can be obtained, the binder sheet can be bonded to the substrate even without increasing the density of the binder layer (even without compaction), enabling processing under a wider range of molding conditions.

[0630] Examples of active electrode materials mentioned above include positive electrode active materials and negative electrode active materials.

[0631] As the positive electrode active material, there are no particular limitations as long as it can electrochemically encapsulate / release alkali metal ions; for example, materials containing an alkali metal and at least one transition metal are preferred. Specific examples include transition metal composite oxides containing alkali metals and transition metal phosphate compounds containing alkali metals. Among these, transition metal composite oxides containing alkali metals that can generate high voltage are particularly preferred as the positive electrode active material. Examples of the aforementioned alkali metal ions include lithium ions, sodium ions, and potassium ions. In a preferred embodiment, the alkali metal ion can be lithium ions. That is, in this embodiment, the alkali metal ion secondary battery is a lithium-ion secondary battery.

[0632] Examples of transition metal composite oxides containing alkali metals include: Formula: M a Mn 2-b M 1 b O4 represents alkali metal manganese spinel composite oxides (such as lithium manganese spinel composite oxides). (In the formula, M is at least one metal selected from the group consisting of Li, Na, and K; 0.9 ≤ a; 0 ≤ b ≤ 1.5; M 1 (It is selected from at least one metal in the group consisting of Fe, Co, Ni, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si and Ge); Formula: MNi 1-c M 2 c O2 represents alkali metal nickel composite oxides (lithium nickel composite oxides, etc.). (In the formula, M is at least one metal selected from the group consisting of Li, Na, and K; 0 ≤ c ≤ 0.5; M 2(Selected as at least one metal from the group consisting of Fe, Co, Mn, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si, and Ge); or Formula: MCo 1-d M 3 d O2 represents alkali metal cobalt composite oxides (lithium cobalt composite oxides, etc.). (In the formula, M is at least one metal selected from the group consisting of Li, Na, and K; 0 ≤ d ≤ 0.5; M 3 It is selected from at least one metal chosen from the group consisting of Fe, Ni, Mn, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si, and Ge.

[0633] In the above, M is preferably a metal selected from the group consisting of Li, Na and K, more preferably Li or Na, and even more preferably Li.

[0634] From the perspective of providing secondary batteries with high energy density and high output, MCoO2, MMnO2, MNiO2, MMn2O4, and MNi are preferred. 0.8 Co 0.15 Al 0.05 O2, or MNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, etc., preferably compounds represented by the following general formula (3).

[0635]

[0636] (In the formula, M is at least one metal selected from the group consisting of Li, Na, and K, M 5 The value is selected from at least one element in the group consisting of Fe, Cu, Zn, Al, Sn, Cr, V, Ti, Mg, Ca, Sr, B, Ga, In, Si, and Ge, where (h+i+j+k)=1.0, 0≤h≤1.0, 0≤i≤1.0, 0≤j≤1.5, and 0≤k≤0.2).

[0637] Examples of transition metal phosphate compounds containing alkali metals include compounds represented by the following general formula (4):

[0638] (In the formula, M is at least one metal selected from the group consisting of Li, Na, and K, M 4The term "selected from at least one metal from the group consisting of V, Ti, Cr, Mn, Fe, Co, Ni, and Cu, where 0.5 ≤ e ≤ 3, 1 ≤ f ≤ 2, and 1 ≤ g ≤ 3" is used. Among these, M is preferably a metal selected from the group consisting of Li, Na, and K, more preferably Li or Na, and even more preferably Li. That is, as the aforementioned alkali metal transition metal phosphate compound, a lithium-containing transition metal phosphate compound is preferred.

[0639] The transition metals used in the aforementioned lithium-containing transition metal phosphate compounds are preferably V, Ti, Cr, Mn, Fe, Co, Ni, Cu, etc. Specific examples include iron phosphates such as LiFePO4, Li3Fe2(PO4)3, and LiFeP2O7; cobalt phosphates such as LiCoPO4; and substances obtained by replacing a portion of the transition metal atoms that form the main body of these lithium transition metal phosphate compounds with other elements such as Al, Ti, V, Cr, Mn, Fe, Co, Li, Ni, Cu, Zn, Mg, Ga, Zr, Nb, and Si. The lithium-containing transition metal phosphate compounds preferably have an olivine-type structure.

[0640] Other positive electrode active materials include lithium-nickel composite oxides. Among these lithium-nickel composite oxides, the positive electrode active material represented by the following general formula (5) is preferred:

[0641] (In the formula, x is 0.01≤x≤0.7, y is 0.9≤y≤2.0, and M represents a metal atom (excluding Li and Ni)).

[0642] Other examples of positive electrode active materials include MFePO4 and MNi. 0.8 Co 0.2 O2, M 1.2 Fe 0.4 Mn 0.4 O2, MNi 0.5 Mn 1.5 O2, MV3O6, M2MnO3, etc. Especially M2MnO3 and MNi 0.5 Mn 1.5 Positive electrode active materials such as O2 (where M is at least one metal selected from the group consisting of Li, Na, and K) do not have a broken crystal structure when the secondary battery is operated at a voltage exceeding 4.4V or 4.6V, which is preferred from this perspective. Therefore, electrochemical devices such as secondary batteries using positive electrode materials containing the positive electrode active materials described above do not easily experience a decrease in residual capacity or a change in the rate of increase in resistance even when stored at high temperatures, and their battery performance does not deteriorate even when operating at high voltages, making them preferred.

[0643] As other positive electrode active materials, M2MnO3 and MM 6 O2 (where M is at least one metal selected from the group consisting of Li, Na, and K, and M 6 is a transition metal such as Co, Ni, Mn, Fe, etc.) and solid solution materials.

[0644] As the above solid solution material, for example, a general formula M x [Mn (1-y) M 7 y O z The alkali metal manganese oxide shown. Here, M in the formula is at least one metal selected from the group consisting of Li, Na, and K, and M 7 is composed of at least one metal element other than M and Mn, and for example, contains one or more elements selected from the group consisting of Co, Ni, Fe, Ti, Mo, W, Cr, Zr, and Sn. In addition, the values of x, y, and z in the formula are in the range of 1 < x < 2, 0 ≤ y < 1, and 1.5 < z < 3. Among them, Li 1.2 Mn 0.5 Co 0.14 Ni 0.14 O2 such a manganese-containing solid solution material based on Li2MnO3 and solid-dissolved with LiNiO2 and LiCoO2 can provide an alkali metal ion secondary battery with high energy density and is preferred in this regard.

[0645] In addition, if the positive electrode active material contains lithium phosphate, the continuous charging characteristics are improved, so it is preferred. The use of lithium phosphate is not limited, and it is preferred to mix and use the above positive electrode active material with lithium phosphate. The amount of lithium phosphate used is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and further preferably 0.5% by mass or more with respect to the lower limit of the total of the above positive electrode active material and lithium phosphate, and the upper limit is preferably 10% by mass or less, more preferably 8% by mass or less, and further preferably 5% by mass or less.

[0646] Examples of the shape of the particles of the positive electrode active material include the conventional block shape, polyhedral shape, spherical shape, ellipsoidal shape, plate shape, needle shape, columnar shape, etc. In addition, the primary particles can also aggregate to form secondary particles.

[0647] The median diameter d50 of the positive electrode active material particles (the secondary particle size when primary particles agglomerate to form secondary particles) is preferably 0.1 μm or more, more preferably 0.5 μm or more, further preferably 0.8 μm or more, and most preferably 1.0 μm or more. It is also preferably 30 μm or less, more preferably 27 μm or less, further preferably 25 μm or less, and most preferably 22 μm or less. If the diameter is less than the lower limit, a high tap density product may not be obtained; if the diameter exceeds the upper limit, lithium diffusion within the particles takes longer, which can lead to problems such as reduced battery performance. Here, by mixing two or more of the above-mentioned positive electrode active materials with different median diameters d50, the fillability during positive electrode fabrication can be further improved.

[0648] The median diameter d50 was measured using a known laser diffraction / scattering particle size distribution measuring device. Using a HORIBA LA-920 as the particle size distribution measuring device and a 0.1% (w / w) sodium hexametaphosphate aqueous solution as the dispersion medium, the refractive index was set to 1.24 after 5 minutes of ultrasonic dispersion.

[0649] The preferred BET specific surface area of ​​the positive electrode active material is 0.1 m². 2 / g or more, more preferably 0.2m 2 / g or more, more preferably 0.3m 2 / g or more, with an upper limit preferably of 50m 2 / g or less, more preferably 40m 2 / g or less, more preferably 30m 2 Below / g. If the BET specific surface area is less than this range, the battery performance is prone to deterioration; if the BET specific surface area is greater than this range, the tap density is difficult to improve, and sometimes the processability during the formation of the positive electrode active material layer is prone to problems.

[0650] The BET specific surface area is defined as follows: using a surface area meter (e.g., a fully automated surface area measuring device manufactured by Riken Corporation of Okura), the sample is pre-dried at 150°C for 30 minutes under nitrogen flow. Then, a nitrogen-helium mixed gas is precisely adjusted to a relative pressure of 0.3 nitrogen relative to atmospheric pressure. The measurement is performed by the nitrogen adsorption BET single-point method based on gas flow. The obtained value is used to define the BET specific surface area.

[0651] The positive electrode active material is preferably composed mainly of secondary particles. The particles of the positive electrode active material preferably have an average secondary particle size of 40 μm or less, and contain 0.5 vol% to 30.0 vol% of primary particles with an average primary particle size of 1 μm or less. By containing particles with an average primary particle size of 1 μm or less, the contact area with the electrolyte is increased, which further accelerates lithium-ion diffusion between the electrode binder and the electrolyte, thereby improving the battery's output performance.

[0652] To manufacture the positive electrode, the aforementioned positive electrode active materials can be used alone, or two or more with different compositions can be combined in any combination or proportion. As a preferred combination in this case, LiCoO2 and LiNi can be cited as examples. 0.33 Co 0.33 Mn 0.33 Combinations of ternary systems such as O2, combinations of LiCoO2 and LiMn2O4 or substances in which a portion of Mn is replaced by other transition metals, or combinations of LiFePO4 and LiMn2O4.

[0653] From the perspective of high battery capacity, the content of the aforementioned positive electrode active material is preferably 50% to 99.5% by mass, more preferably 80% to 99% by mass, of the positive electrode compound. Furthermore, the content in the positive electrode active material layer is preferably 80% by mass or more, more preferably 82% by mass or more, and particularly preferably 84% by mass or more. The upper limit is preferably 99% by mass or less, more preferably 98% by mass or less. If the content of the positive electrode active material in the positive electrode active material layer is low, the capacity may sometimes be insufficient. Conversely, if the content is too high, the strength of the positive electrode may sometimes be insufficient.

[0654] There are no particular limitations on the negative electrode active material. Examples include materials containing carbonaceous materials such as lithium metal, artificial graphite, graphite carbon fiber, resin-sintered carbon, thermally decomposed vapor-grown carbon, coke, mesophase carbon microspheres (MCMB), furfuryl alcohol resin-sintered carbon, polyphenylene oxide, pitch-based carbon fiber, vapor-grown carbon fiber, natural graphite and non-graphitizable carbon, silicon-containing compounds such as silicon and silicon alloys, and Li4Ti5O. 12 Any one or a mixture of two or more of the above. Among them, it is particularly preferred to use a substance containing at least a portion of carbonaceous material or a silicon-containing compound.

[0655] The negative electrode active material used in this disclosure preferably contains silicon as a constituent element. By including silicon as a constituent element, high-capacity batteries can be manufactured.

[0656] As silicon-containing materials, silicon particles, particles having a structure of silicon microparticles dispersed in a silicon-based compound, silicon oxide particles with the general formula SiOx (0.5 ≤ x ≤ 1.6), or mixtures thereof are preferred. By using these substances, negative electrode mixtures for lithium-ion secondary batteries with higher initial charge-discharge efficiency, higher capacity, and excellent cycle characteristics are obtained.

[0657] The physical properties of the silicon-containing particles can be appropriately selected based on the target composite particles. For example, the average particle size is preferably 0.1 μm to 50 μm, with a lower limit more preferably 0.2 μm or more, and even more preferably 0.5 μm or more. The upper limit is more preferably 30 μm or less, and even more preferably 20 μm or less. The above-mentioned average particle size is expressed as the weight-average particle size in particle size distribution determination based on laser diffraction.

[0658] The preferred specific surface area for BET is 0.5m². 2 / g~100m 2 / g, more preferably 1m 2 / g~20m 2 / g. If the specific surface area of ​​BET is 0.5m² 2 If the content is above / g, there is no possibility of reduced adhesion or decreased battery performance during processing to the electrode. Additionally, if it is 100m 2 When the content of silica on the particle surface is below a certain value, the proportion of silica on the particle surface increases, and the battery capacity cannot be reduced when used as a negative electrode material for lithium-ion secondary batteries.

[0659] By applying a carbon coating to the silicon-containing particles, conductivity is imparted, and an improvement in battery performance is observed. Methods for imparting conductivity include mixing the silicon-containing particles with conductive particles such as graphite, coating the surface of the silicon-containing particles with a carbon coating film, and combining both methods. The carbon coating method is preferred, and chemical vapor deposition (CVD) is more preferred.

[0660] To increase the capacity of the obtained electrode mixture, the content of the aforementioned negative electrode active material in the electrode mixture is preferably 40% by mass or more, more preferably 50% by mass or more, and particularly preferably 60% by mass or more. Furthermore, the upper limit is preferably 99% by mass or less, more preferably 98% by mass or less.

[0661] The electrode mixture disclosed herein preferably further comprises a conductive additive.

[0662] As the aforementioned conductive additives, any known conductive material can be used. Specific examples include metallic materials such as copper and nickel, graphite such as natural graphite and artificial graphite, carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal cracking black, as well as carbon materials such as needle coke, carbon nanotubes, fullerenes, and amorphous carbon such as VGCF. It should be noted that one of these additives can be used alone, or two or more can be used in any combination and proportion.

[0663] The conductive additive is typically used in the electrode mixture at a concentration of 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 1% by mass or more, and typically 50% by mass or less, preferably 30% by mass or less, more preferably 15% by mass or less. If the concentration is below this range, the conductivity may be insufficient. Conversely, if the concentration is above this range, the battery capacity may be reduced.

[0664] The electrode mixture disclosed herein may further comprise a thermoplastic resin. Examples of thermoplastic resins include polyvinylidene fluoride, polypropylene, polyethylene, polystyrene, polyethylene terephthalate, and polyoxyethylene. One type may be used alone, or two or more types may be used in any combination and proportion.

[0665] The proportion of thermoplastic resin relative to the electrode active material is typically 0.01% by mass or more, preferably 0.05% by mass or more, more preferably 0.10% by mass or more, and typically 3.0% by mass or less, preferably 2.5% by mass or less, more preferably 2.0% by mass or less. Adding thermoplastic resin can improve the mechanical strength of the electrode. However, if this range is exceeded, the proportion of the electrode active material in the electrode mixture decreases, sometimes leading to problems such as reduced battery capacity or increased resistance between active materials.

[0666] In the electrode compound disclosed herein, the binder content relative to the electrode compound can be 0.1% by mass or more, preferably 0.2% by mass or more, more preferably 0.5% by mass or more, and can also be 50% by mass or less, preferably 40% by mass or less, more preferably 30% by mass or less, more preferably 10% by mass or less, particularly preferably 5% by mass or less, and most preferably 3% by mass or less. If the binder ratio is too low, the active material of the electrode compound may not be sufficiently retained, resulting in insufficient mechanical strength of the electrode compound sheet and deterioration of battery performance such as cycle characteristics. On the other hand, if the binder ratio is too high, it may sometimes lead to a decrease in battery capacity and conductivity. The binder of this disclosure has excellent adhesion, so even with a low content, the active material of the electrode can be sufficiently retained.

[0667] In the electrode adhesive disclosed herein, the binder component preferably consists substantially only of the aforementioned polymer composition, more preferably only of the aforementioned polymer composition. "The binder component consists substantially only of the aforementioned polymer composition" means that the content of the aforementioned polymer composition in the binder component constituting the electrode adhesive is 95.0% by mass or more relative to the aforementioned binder component. The content of the aforementioned polymer composition relative to the aforementioned binder component is preferably 98.0% by mass or more, more preferably 99.0% by mass or more, further preferably 99.5% by mass or more, particularly preferably 99.9% by mass or more, and most preferably 99.95% by mass or more.

[0668] The electrode mixture disclosed herein is preferably in the form of tablets.

[0669] The electrode mixture disclosed herein is suitable for use as an electrode mixture in secondary batteries. In particular, the electrode mixture disclosed herein is suitable for lithium-ion secondary batteries. When used in secondary batteries, the electrode mixture disclosed herein is typically used in sheet form.

[0670] The thickness of the aforementioned electrode mixture sheet is preferably 300 μm or less, more preferably 250 μm or less, even more preferably 200 μm or less, even more preferably 180 μm or less, particularly preferably 150 μm or less, and preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more.

[0671] The following is an example of a specific manufacturing method for an electrode compound sheet containing an electrode compound. The electrode compound sheet can be obtained by a manufacturing method having the following steps: a step (1) of mixing a raw material composition containing an electrode active material and a binder and a conductive additive as needed; a step (2) of molding the raw material composition obtained by the above step (1) into a block shape; and a step (3) of calendering the block-shaped raw material composition obtained by the above step (2) into a sheet shape.

[0672] In the stage of mixing the raw material composition in the above process (1), the raw material composition exists in a state where the electrode active material, binder, etc. are simply mixed without a fixed shape. As specific mixing methods, examples include mixing using a drum mixer, a conical screw mixer, a single screw mixer, a twin screw mixer, a grinding mill, a stirring mixer, a planetary mixer, a Henschel mixer, a high-speed mixer, etc.

[0673] In the above process (1), the binder mixing conditions are preferably 3000 rpm or less. Preferably, it is 10 rpm or more, more preferably 15 rpm or more, and even more preferably 20 rpm or more. Furthermore, it is preferably 2000 rpm or less, more preferably 1500 rpm or less, and even more preferably 1000 rpm or less. If the mixing time is below these ranges, it will be too long and affect productivity. Furthermore, if the mixing time exceeds these ranges, excessive fibrillation may occur, potentially resulting in electrode adhesive sheets with poor strength and flexibility.

[0674] In the above process (2), forming into a block refers to making the raw material composition into a block. Specific methods for forming into a block include extrusion molding and compression molding. In addition, the term "block" does not refer to a particularly specific shape; it can refer to any state that results in a block, including rod-shaped, sheet-shaped, spherical, cubic, and other forms.

[0675] As a specific calendering method in the above process (3), calendering methods using roller presses, flat presses, calendering rolls, etc. can be cited.

[0676] Furthermore, it is preferable to have a step (4) after step (3): applying a greater load to the obtained calendered sheet and calendering it into a thinner sheet. It is also preferable to repeat step (4). In this way, the calendered sheet is not thinned all at once, but calendered little by little in stages, thereby achieving better softness. As for the number of steps (4), it is preferable to repeat them more than twice and less than ten times, more preferably more than three times and less than nine times. As a specific calendering method, for example, the following method can be used: rotating two or more rollers and passing the calendered sheet between them, thereby processing it into a thinner sheet.

[0677] In addition, from the perspective of adjusting the diameter of the raw fibers, it is preferable to have a step (5) after step (3) or step (4): crushing the calendered sheet and then re-forming it into a block shape, and calendering it into a sheet shape. It is also preferable to repeat step (5). As for the number of times step (5) is performed, it is preferable to perform it more than once and less than 12 times, and more preferably more than twice and less than 11 times.

[0678] In step (5), specific methods for coarsely crushing the calendered sheet and forming it into a block shape can include folding the sheet, forming it into a rod or film sheet, or fragmenting it. In this disclosure, "coarse crushing" refers to changing the shape of the calendered sheet obtained in step (3) or step (4) into other shapes in order to calender it into a sheet shape in the next step, and also includes the case of simply folding the calendered sheet.

[0679] In addition, step (4) can be performed after step (5), or it can be repeated. Alternatively, uniaxial or biaxial stretching can be performed in steps (2) or (3), (4), and (5). Furthermore, the diameter of the fibrils can be adjusted according to the degree of coarseness in step (5).

[0680] In the above steps (3), (4), or (5), the calendering rate is preferably 10% or more, more preferably 20% or more, and preferably 80% or less, more preferably 65% ​​or less, and even more preferably 50% or less. If it is less than the above range, time will be consumed as the number of calendering cycles increases, affecting productivity. In addition, if it exceeds the above range, excessive fibrillation will occur, which may result in electrode composite sheets with poor strength and softness. It should be noted that the calendering rate mentioned here refers to the rate of reduction of the thickness of the sample after processing relative to the thickness before calendering. The sample before calendering can be a block-shaped raw material composition or a sheet-shaped raw material composition. The thickness of the sample refers to the thickness in the direction in which the load is applied during calendering.

[0681] The aforementioned electrode mixture tablets can also be suitably manufactured by the following manufacturing method, characterized in that it includes: Process (a): The step of mixing powder components (electrode active materials, etc.) and a binder to form an electrode mixture; and Process (b): The step of calendering or extruding the electrode mixture to manufacture a sheet. The mixing of process (a) includes: (a1) A process of homogenizing powder components and binders to form powder; (a2) A process of preparing an electrode mixture by mixing the powdered raw material mixture obtained by process (a1).

[0682] For example, PTFE has two transition temperatures: approximately 19°C and approximately 30°C. Below 19°C, PTFE can be easily mixed while maintaining its shape. However, above 19°C, the structure of the PTFE particles becomes looser and more sensitive to mechanical shear. Above 30°C, a higher degree of fibrillation occurs.

[0683] Therefore, the homogenization of (a1) is preferably carried out at a temperature below 19°C, preferably between 0°C and 19°C.

[0684] That is, in such a (a1), it is preferable to mix and homogenize while suppressing fibrillation.

[0685] The mixing process in the next step (a2) is preferably carried out at a temperature of 30°C or above to promote fibrillation.

[0686] The above process (a2) is preferably carried out at a temperature of 30°C to 150°C, more preferably at 35°C to 120°C, and even more preferably at 40°C to 100°C.

[0687] In one embodiment, the calendering or extrusion of the above-described step (b) is performed at a temperature between 30°C and 150°C, preferably between 35°C and 120°C, and more preferably between 40°C and 100°C.

[0688] The mixing process in step (a) above is preferably performed while shearing force is applied.

[0689] Specific mixing methods include using drum mixers, conical screw mixers, single-screw mixers, twin-screw mixers, grinding mills, agitators, planetary mixers, Henschel mixers, and high-speed mixers.

[0690] The mixing conditions can be achieved simply by setting the rotation speed and mixing time appropriately. For example, the rotation speed is preferably 15,000 rpm or less. More preferably, it is 10 rpm or more, more preferably 50 rpm or more, and even more preferably 100 rpm or more. Furthermore, it is preferably 12,000 rpm or less, more preferably 10,000 rpm or less, and even more preferably 8,000 rpm or less. If the speed is below these ranges, the mixing time will be excessive, which will affect productivity. Conversely, if the speed exceeds these ranges, excessive fibrillation may occur, potentially resulting in electrode composite sheets with poor strength.

[0691] In step (a1), it is preferable to use a weaker shearing force than in step (a2).

[0692] In addition, process (a1) is preferably performed in a shorter time than process (a2).

[0693] In step (a2) above, the raw material composition preferably does not contain a liquid solvent, but a small amount of lubricant may also be used. That is, a paste can be prepared by adding a lubricant to the powdered raw material mixture obtained by step (a1) above.

[0694] There are no particular limitations on the above-mentioned lubricants, and examples include water, ether compounds, alcohols, ionic liquids, carbonates, aliphatic hydrocarbons (low-polarity solvents such as heptane and xylene), isoparaffin hydrocarbon compounds, and petroleum fractions (gasoline (C4-C10), naphtha (C4-C11), kerosene / alkanes (C10-C16) and mixtures thereof).

[0695] The moisture content of the above-mentioned lubricant is preferably below 1000 ppm.

[0696] Maintaining a moisture content of 1000 ppm or less is preferred in terms of reducing the degradation of electrochemical devices. More preferably, the moisture content is 500 ppm or less.

[0697] When using the above-mentioned lubricants, solvents with low polarity such as butyl butyrate or ether compounds are particularly preferred.

[0698] When using the above-mentioned lubricant, its amount relative to the total weight of the composition supplied to step (a1) can be 5.0 parts by weight to 35.0 parts by weight, preferably 10.0 parts by weight to 30.0 parts by weight, and more preferably 15.0 parts by weight to 25.0 parts by weight.

[0699] The above-mentioned raw material composition preferably does not contain a liquid medium. Existing electrode binder formation methods typically use solvents that dissolve the binder to prepare a slurry containing powders as electrode binder components, and then coat / dry this slurry to prepare electrode binder sheets. In this case, a solvent that disperses or dissolves the binder is used. However, solvents that can dissolve binder resins are conventionally limited to specific solvents such as N-methylpyrrolidone. Due to their high polarity and the drying process, the use of solvents increases costs and procedures. Furthermore, they react with electrolytes such as electrolytes and solid electrolytes, causing electrolyte degradation; therefore, residual components during slurry preparation and after drying sometimes contribute to reduced battery performance. Additionally, in the case of low-polarity solvents such as heptane, the amount of binder resin that can be dissolved is very limited, and sometimes the flash point is low, making the process cumbersome.

[0700] By using a powdery binder with low moisture content instead of a solvent during the formation of the electrode binder sheet, it is possible to manufacture a battery with less electrolyte degradation. Furthermore, in the above manufacturing method, it is possible to manufacture an electrode binder sheet containing a binder with a fine fibrous structure, and by eliminating the need to prepare a slurry, the burden of the manufacturing process can be reduced.

[0701] Step (b) is calendering or extrusion. Calendering and extrusion can be carried out by known methods. This allows the electrode mixture to be formed into a sheet shape.

[0702] Step (b) preferably includes: (b1) a step of molding the electrode mixture obtained by step (a) into a block shape; and (b2) a step of calendering or extruding the block electrode mixture.

[0703] Forming into a block shape means making the electrode mixture into one block.

[0704] Specific methods for shaping into blocks include extrusion molding and compression molding.

[0705] Furthermore, the term "block-like" does not refer to a particularly specific shape; it simply means that the block is formed, including shapes such as rods, sheets, spheres, and cubes. Preferably, the diameter of the cross-section or the smallest side of the block is 10,000 μm or more. More preferably, it is 20,000 μm or more.

[0706] As a specific method for calendering or extrusion molding in the above-mentioned process (b2), one example is the method of calendering the electrode mixture using a roller press, calendering roller machine, etc.

[0707] The above-described step (b) is preferably performed at a temperature between 30°C and 150°C. As mentioned above, PTFE has a glass transition temperature around 30°C, and therefore readily fibrillates above 30°C. Therefore, step (b) is preferably performed at such a temperature.

[0708] Furthermore, calendering or extrusion, due to the application of shear force, causes PTFE to be fibrillated and thus formed.

[0709] Following step (b), it is preferable to further perform step (c) by applying a greater load to the resulting calendered sheet to roll it into a thinner sheet. It is also preferable to repeat step (c). In this way, instead of thinning the calendered sheet all at once, the calendering is performed in stages, little by little, thereby achieving better softness.

[0710] The number of times process (c) is preferably 2 to 10 times, and more preferably 3 to 9 times.

[0711] As a specific calendering method, one can cite the following method: rotating two or more rollers and passing a calender sheet between them, thereby processing it into a thinner sheet.

[0712] Furthermore, from the perspective of adjusting sheet strength, it is preferable to have a step (d) after step (b) or step (c): the calendered sheet is coarsely crushed and then re-formed into a block shape, and calendered into a sheet shape. It is also preferable to repeat step (d). As for the number of times step (d) is performed, it is preferable to perform it more than once and less than 12 times, and more preferably more than twice and less than 11 times.

[0713] In step (d), specific methods for coarsely crushing and shaping the calendered sheet into blocks include folding the calendered sheet, shaping it into rods or films, and fragmentation. In this disclosure, "coarse crushing" refers to changing the shape of the calendered sheet obtained in step (b) or step (c) to another shape in order to calender it into a sheet in the next step, and also includes the case of simply folding the calendered sheet.

[0714] Alternatively, step (c) can be performed after step (d), or it can be repeated.

[0715] Alternatively, uniaxial or biaxial stretching can be performed in process (a), (b), (c), or (d).

[0716] Alternatively, the strength of the flakes can be adjusted according to the degree of coarseness in process (d).

[0717] In processes (b), (c), or (d) above, the calendering rate is preferably 10% or more, more preferably 20% or more, and preferably 80% or less, more preferably 65% ​​or less, and even more preferably 50% or less. If it is less than the above range, the time consumed increases with the number of calendering cycles, affecting productivity. Furthermore, if it exceeds the above range, excessive fibrillation occurs, potentially resulting in electrode composite sheets with poor strength and flexibility.

[0718] It should be noted that the rolling rate mentioned here refers to the rate of reduction in the thickness of the sample after processing relative to its thickness before rolling. The sample before rolling can be a block-shaped raw material composition or a sheet-shaped raw material composition. The thickness of the sample refers to the thickness in the direction in which the load is applied during rolling.

[0719] The above-mentioned processes (c) to (d) are preferably performed at a temperature of 30°C or higher, more preferably at 60°C or higher. Furthermore, it is preferable to perform them at a temperature of 150°C or lower.

[0720] The above-mentioned electrode compound sheets can be used as electrode compound sheets for secondary batteries. They can also be used as either negative or positive electrodes. In particular, the above-mentioned electrode compound sheets are suitable for lithium-ion secondary batteries.

[0721] This disclosure also provides an electrode comprising the polymer composition, binder, electrode active material, and current collector of the present disclosure described above. The electrode of this disclosure can improve the coulombic efficiency of electrochemical devices. Furthermore, even with a small amount of binder, the electrode active material can be maintained, thus allowing for the addition of more active materials, conductive additives, and other materials that improve the characteristics of electrochemical devices. Additionally, the adhesive sheet exhibits excellent adhesion to substrates such as metal foils.

[0722] The electrode of this disclosure may include the electrode mixture (preferably an electrode mixture sheet) and a current collector as described above.

[0723] The electrode disclosed herein can be either a positive electrode or a negative electrode.

[0724] The aforementioned positive electrode preferably comprises a current collector and an electrode mixture sheet containing the aforementioned positive electrode active material. Examples of materials that can be used for the current collector include: metals such as aluminum, titanium, tantalum, stainless steel, and nickel, or their alloys; and carbon materials such as carbon cloth and carbon paper. Among these, metal materials, particularly aluminum or its alloys, are preferred.

[0725] The preferred density of the positive electrode compound tablet is 2.80 g / cm³. 3The above, and more preferably 3.00 g / cm 3 The above, and more preferably, is 3.20 g / cm³. 3 In addition, the preferred value is 3.80 g / cm³. 3 The following, or more preferably, is 3.75 g / cm³. 3 The following, and more preferably, is 3.70 g / cm³. 3 The following range applies. Exceeding this range can sometimes lead to internal cracking. Conversely, falling below this range can sometimes reduce the conductivity between active materials, resulting in increased battery resistance and lower output.

[0726] The thickness of the positive electrode is not particularly limited. From the perspective of high capacity and high output, the thickness of the mixture layer after subtracting the thickness of the metal foil of the current collector is preferably 10 μm or more, more preferably 20 μm or more, and preferably 500 μm or less, more preferably 450 μm or less, relative to one side of the current collector.

[0727] The aforementioned negative electrode preferably comprises a current collector and an electrode mixture sheet containing the aforementioned negative electrode active material. Examples of materials for the current collector include metals such as copper, nickel, titanium, tantalum, and stainless steel, or their alloys; and carbon materials such as carbon cloth and carbon paper. Among these, metal materials are preferred, and copper, nickel, or their alloys are particularly preferred.

[0728] The preferred density of the negative electrode mixture tablets is 1.3 g / cm³. 3 The above, and more preferably, is 1.4 g / cm³ 3 The above, and more preferably 1.5 g / cm 3 In addition, the preferred value is 2.0 g / cm³. 3 The following, or more preferably, is 1.9 g / cm³ 3 The following, and more preferably, is 1.8 g / cm³. 3 The following range applies. Exceeding this range can sometimes lead to internal cracking. Conversely, falling below this range can sometimes reduce the conductivity between active materials, resulting in increased battery resistance and lower output.

[0729] The thickness of the negative electrode is not particularly limited. From the perspective of high capacity and high output, the thickness of the mixture layer after subtracting the thickness of the metal foil of the current collector is preferably 10 μm or more, more preferably 20 μm or more, and preferably 500 μm or less, more preferably 450 μm or less, relative to one side of the current collector.

[0730] Examples of current collector shapes for the positive and negative electrodes include metal foil, metal mesh, stamped metal, and foamed metal. Among these, metal foil is preferred. It should be noted that the metal foil can be suitably formed into a mesh. The thickness of the metal foil is arbitrary, typically 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more, and typically 1 mm or less, preferably 100 μm or less, more preferably 50 μm or less. If the metal foil is thinner than this range, the strength required for use as a current collector may be insufficient. Conversely, if the metal foil is thicker than this range, the processability may be compromised.

[0731] In addition, from the perspective of improving the adhesion between the current collector and the positive electrode active material layer and reducing the electrical contact resistance, it is also preferable to roughen the surface of the current collector.

[0732] The surface roughness of the current collector, expressed as Sa (arithmetic mean height), is preferably about 260 nm or more, more preferably about 280 nm or more, and even more preferably about 300 nm or more.

[0733] Furthermore, from the viewpoint of reducing the electrical contact resistance between the current collector and the positive electrode active material layer, it is preferable to coat the surface of the current collector with a conductive additive. Examples of conductive additives include carbon or precious metals such as gold, platinum, and silver. From the perspective of low weight, carbon is particularly preferred.

[0734] The positive and negative electrodes can be manufactured using conventional methods. For example, a method can be used to laminate the electrode composite sheet with the current collector using an adhesive and then press them together.

[0735] This disclosure also provides a secondary battery having the electrodes described above.

[0736] The secondary battery disclosed herein can be a secondary battery using an electrolyte or a solid-state secondary battery.

[0737] It should be noted that, in this specification, a solid-state secondary battery is any secondary battery that contains a solid electrolyte. It can be a semi-solid-state secondary battery that contains both solid electrolyte and liquid components as electrolytes, or a fully solid-state secondary battery that contains only solid electrolyte as electrolyte.

[0738] Secondary batteries using the above-described electrolyte can utilize electrolytes, separators, and other components known for use in secondary batteries. These will be explained in detail below.

[0739] As the electrolyte described above, a non-aqueous electrolyte is preferred. As a non-aqueous electrolyte, an electrolyte prepared by dissolving a known electrolyte salt in a known organic solvent for dissolving electrolyte salts can be used.

[0740] As an organic solvent for dissolving electrolyte salts, there are no particular limitations; one or more of the following can be used: propylene carbonate, ethylene carbonate, butyl carbonate, γ-butyrolactone, 1,2-dimethoxyethane, 1,2-diethoxyethane, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, etc.; and fluorinated solvents such as fluoroethylene carbonate, fluoroether, fluorinated carbonate, etc.

[0741] Examples of electrolyte salts include LiClO4, LiAsF6, LiBF4, LiPF6, LiN(SO2CF3)2, and LiN(SO2C2F5)2. From the perspective of good cycling characteristics, LiPF6, LiBF4, LiN(SO2CF3)2, LiN(SO2C2F5)2, or combinations thereof are particularly preferred.

[0742] The concentration of the electrolyte salt is preferably 0.8 mol / L or more, and more preferably 1.0 mol / L or more. The upper limit also depends on the organic solvent used to dissolve the electrolyte salt, and is usually 4.0 mol / L or less.

[0743] The secondary battery using the above-mentioned electrolyte preferably also includes a separator. Regarding the material and shape of the separator, there are no particular limitations as long as the electrolyte is stable and has excellent liquid retention; known separators can be used. Preferably, a porous sheet or non-woven fabric-like material with excellent liquid retention, formed from a material stable to the electrolyte, such as resin, glass fiber, or inorganic material, is used.

[0744] The aforementioned solid-state secondary battery is preferably an all-solid-state secondary battery. The aforementioned solid-state secondary battery is preferably a lithium-ion battery, and also preferably a sulfide-based solid-state secondary battery.

[0745] The aforementioned solid-state secondary battery preferably comprises a positive electrode, a negative electrode, and a solid electrolyte layer between the positive electrode and the negative electrode.

[0746] In the above-mentioned solid-state secondary battery, the binder disclosed herein can be used for the electrode layer or for the solid electrolyte layer.

[0747] Solid-state secondary battery binders (preferably binder sheets) containing the binder and solid electrolyte of this disclosure, and solid electrolyte layers (preferably solid electrolyte layer sheets) containing the binder and solid electrolyte of this disclosure are also preferred embodiments of this disclosure.

[0748] The solid electrolyte used in the compound for solid-state secondary batteries can be either a sulfide-based solid electrolyte or an oxide-based solid electrolyte. In particular, when using a sulfide-based solid electrolyte, there is an advantage of flexibility.

[0749] There are no particular limitations on the aforementioned sulfide-based solid electrolytes, and those selected from Li₂S-P₂S₅, Li₂S-P₂S₃, Li₂S-P₂S₃-P₂S₅, Li₂S-SiS₂, LiI-Li₂S-SiS₂, LiI-Li₂S-P₂S₅, LiI-Li₂S-P₂O₅, LiI-Li₃PO₄-P₂S₅, LiI-Li₂S-SiS₂-P₂S₅, Li₂S-SiS₂-Li₄SiO₄, Li₂S-SiS₂-Li₃PO₄, Li₃PS₄-Li₄GeS₄, Li₂S-P₂S₅ ...P₂S₅, Li₂S-P₂S₅, Li₂S-P₂S₅, Li₂S-P₂S₅, Li₂S-P₂S₅, Li₂S-P₂S₅, Li₂S-P₂S₅, Li₂S-P₂S₅, Li₂S-P₂S₅, Li₂S-P� 3.4 P 0.6 Si 0.4 S4, Li 3.25 P 0.25 Ge 0.76 S4, Li 4-x Ge 1-x P x S4 (X=0.6~0.8), Li 4+y Ge 1-y Ga y S4(y=0.2~0.3), LiPSCl, LiCl, Li 7-x-2y PS 6-x-y Cl x (0.8≦x≦1.7、0 <y≦-0.25x+0.5)、Li 10 SnP2S 12 Any one or more of the following mixtures.

[0750] The aforementioned sulfide-based solid electrolyte preferably contains lithium. Lithium-containing sulfide-based solid electrolytes are particularly preferred from the perspective of electrochemical devices with high energy density, especially for use in solid-state batteries that utilize lithium ions as carriers.

[0751] The oxide-based solid electrolytes are preferably compounds containing oxygen atoms (O), having ionic conductivity of metals belonging to Group 1 or Group 2 of the periodic table, and having electronic insulation.

[0752] As a specific example of a compound, Li can be cited. xa La ya TiO3[xa=0.3~0.7, ya=0.3~0.7](LLT), Li xb La yb Zr zb M bb mb O nb (M bbIt consists of at least one element selected from Al, Mg, Ca, Sr, V, Nb, Ta, Ti, Ge, In, and Sn, where xb satisfies 5 ≤ ​​xb ≤ 10, yb satisfies 1 ≤ yb ≤ 4, zb satisfies 1 ≤ zb ≤ 4, mb satisfies 0 ≤ mb ≤ 2, nb satisfies 5 ≤ ​​nb ≤ 20), and Li. xc B yc M cc zc O nc (M cc For at least one of the elements C, S, Al, Si, Ga, Ge, In, and Sn, xc satisfies 0 ≤ xc ≤ 5, yc satisfies 0 ≤ yc ≤ 1, zc satisfies 0 ≤ zc ≤ 1, nc satisfies 0 ≤ nc ≤ 6), and Li xd (Al,Ga) yd (Ti,Ge) zd Si ad P md O nd (where 1≤xd≤3, 0≤yd≤2, 0≤zd≤2, 0≤ad≤2, 1≤md≤7, 3≤nd≤15), Li (3-2xe) M ee xe D ee O(xe represents a number greater than 0 and less than 0.1, M) ee This represents a divalent metal atom. (D) ee (representing a halogen atom or a combination of two or more halogen atoms), Li xf Si yf O zf (1≤xf≤5,0 <yf≤3,1≤zf≤10)、Li xg S yg O zg (1≤xg≤3,0 <yg≤2,1≤zg≤10)、Li3BO3-Li2SO4、Li2O-B2O3-P2O5、Li2O-SiO2、Li6BaLa2Ta2O 12 Li3PO (4-3 / 2w) N w Li (where w satisfies w<1) has a LISICON (lithium superion conductor) type crystal structure 3.5 Zn 0.25 GeO4, La with a perovskite-type crystal structure 0.51 Li 0.34 TiO 2.94 La 0.55 Li 0.35 TiO3, LiTi2P3O with a NASICON (sodium superionic conductor) crystal structure 12 Li 1+xh+yh (Al,Ga)xh (Ti,Ge) 2-xh Si yh P 3-yh O 12 (where 0≤xh≤1, 0≤yh≤1), Li7La3Zr2O with a garnet-type crystal structure 12 (LLZ), etc. In addition, ceramic materials in which elemental substitutions have been performed on LLZ are also known. For example, Li can be categorized as a partial substitution of LLZ with Al. 6.24 La3Zr2Al 0.24 O 11.98 Li 6.25 Al 0.25 La3Zr2O 12 A portion of the Li was replaced with Ta. 6.6 La3Zr 1.6 Ta 0.4 O 12 A portion of Li after Nb replacement 6.75 La3Zr 1.75 Nb 0.25 O 12 Furthermore, examples include LLZ-based ceramic materials in which at least one element of Mg (magnesium) and A (where A is at least one element selected from the group consisting of Ca (calcium), Sr (strontium), and Ba (barium)) has been substituted for LLZ. Additionally, phosphorus compounds containing Li, P, and O are preferred. Examples include lithium phosphate (Li3PO4), LiPON (LiPON) and LiPOD (LiPON is formed by replacing a portion of the oxygen in lithium phosphate with nitrogen). 1 (D 1 It is selected from at least one of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Ag, Ta, W, Pt, Au, etc. Alternatively, LiAl is also preferred. 1 ON(A 1 (It is selected from at least one of Si, B, Ge, Al, C, Ga, etc.) etc. As specific examples, Li2O-Al2O3-SiO2-P2O5-TiO2-GeO2, Li2O-Al2O3-SiO2-P2O5-TiO2, etc. can be given.

[0753] The aforementioned oxide-based solid electrolyte preferably contains lithium. Lithium-containing oxide-based solid electrolytes are particularly preferred from the perspective of electrochemical devices with high energy density, especially for use in solid-state batteries that utilize lithium ions as carriers.

[0754] The aforementioned oxide-based solid electrolyte is preferably an oxide with a crystalline structure. From the perspective of good Li-ion conductivity, oxides with a crystalline structure are particularly preferred. Examples of oxides with a crystalline structure include perovskite-type (La) oxides. 0.51 Li 0.34 TiO 2.94 etc.), NASICON type (Li 1.3 Al 0.3 Ti 1.7 (PO4)3, etc.), garnet type (Li7La3Zr2O) 12 (LLZ) etc. Among them, garnet type is preferred.

[0755] The aforementioned solid-state secondary battery may have a separator between the positive and negative electrodes. Examples of such separators include porous membranes made of polyethylene or polypropylene; and nonwoven fabrics made of resins such as polypropylene or glass fiber nonwoven fabrics.

[0756] The aforementioned solid-state secondary battery may also include a battery casing. The shape of the battery casing is not particularly limited as long as it can accommodate the positive electrode, negative electrode, and solid electrolyte layer; examples include cylindrical, square, button-shaped, and laminated types.

[0757] The aforementioned solid-state secondary battery can be manufactured, for example, by sequentially stacking a positive electrode, a solid electrolyte layer, and a negative electrode and then pressing them together.

[0758] The implementation methods have been described above. However, it should be understood that various changes can be made to the methods and specific circumstances without departing from the spirit and scope of the claims.

[0759] Example

[0760] The present disclosure will now be described in more detail by way of examples, but the present disclosure is not limited to these examples.

[0761] Various physical properties were determined by the following methods.

[0762] <Average primary particle size>

[0763] The determination was performed using dynamic light scattering. An aqueous dispersion of the fluoropolymer was prepared with a solid content adjusted to approximately 1.0% by mass, and measured 70 times cumulatively at 25°C using an ELSZ-1000S (manufactured by Otsuka Electronics Co., Ltd.). The refractive index of the solvent (water) was 1.3328, and the viscosity of the solvent (water) was 0.8878 mPa·s.

[0764] <Polymer solids concentration>

[0765] 1 g of the aqueous polymer dispersion was dried in a forced-air dryer under the conditions of 150 °C for 60 minutes, and the value representing the ratio of the mass of the heating residue to the mass of the aqueous dispersion (1 g) was used, expressed as a percentage.

[0766] <Content of the modifying monomer in PTFE>

[0767] Regarding the HFP content, a film disk was prepared by compression molding of the polymer composition, and based on the infrared absorbance obtained by FT-IR measurement of the film disk, the absorbance at 982 cm -1 divided by the absorbance at 935 cm -1 was multiplied by 0.3 to obtain the value.

[0768] <Endothermic peak temperature>

[0769] For a polymer composition that has not been heated to a temperature above 300 °C, differential scanning calorimetry [DSC] was performed at a heating rate of 10 °C / min, and the temperature corresponding to the minimum point in the obtained heat of fusion curve was taken as the endothermic peak temperature. In the case where there are two or more minimum points in one melting peak, each was taken as the endothermic peak temperature.

[0770] <Standard specific gravity (SSG)>

[0771] Using a sample molded according to ASTM D4895 89, the measurement was carried out by the water displacement method according to ASTM D792.

[0772] <Average aspect ratio of the polymer composition (powder)>

[0773] The polymer composition powder was thinly spread on a black paper surface with air without applying shear to the powder, and the polymer composition was observed with an electron microscope. Image processing was performed on 100 or more randomly selected particles, and the average of the ratio of the long diameter to the short diameter was obtained.

[0774] <Fibrillation presence or absence>

[0775] The fibrillating polymer (PTFE) contained in the polymer composition was observed with an electron microscope by thinly spreading the polymer composition powder on a black paper surface with air without applying shear to the powder. Image processing was performed on 100 or more randomly selected particles, and the average aspect ratio of the fibrillating polymer powder was obtained from the average of the ratio of the long diameter to the short diameter. When the average aspect ratio is 2.5 or less, it is judged that fibrillation of the fibrillating polymer powder has not occurred.

[0776] <Thermoplastic polymer composition>

[0777] By 1 1H-NMR analysis,19 The determination was performed using F-NMR analysis.

[0778] <mfr>

[0779] In accordance with ASTM D1238, using a melt indexer, the mass (g / 10 minutes) of the polymer flowing out of a nozzle with an inner diameter of 2 mm and a length of 8 mm per 10 minutes is measured at the measurement temperature and load determined according to the type of fluoropolymer.

[0780] <Melting point of thermoplastic polymer>

[0781] The melting point is set as the temperature corresponding to the maximum value in the melting heat curve during the second heating at a rate of 10 °C / minute using a differential scanning calorimeter [DSC].

[0782] <Weight-average molecular weight of VT>

[0783] The measurement is carried out by gel permeation chromatography (GPC). Using HLC-8320GPC manufactured by Tosoh Corporation and columns (3 SuperAWM-H connected in series), the measurement is carried out at 50 °C using dimethylformamide (DMF) as a solvent, and calculated from the measured data (reference: polystyrene). <<

[0784] <Average particle size of PVdF and VT powders>

[0785] Using a laser diffraction particle size distribution measuring device (LS13 320) manufactured by Beckman Coulter, the measurement is carried out in a dry state and under a vacuum pressure of 20 mH2O, and calculated based on the obtained particle size distribution (volume basis). The average particle size is equal to the particle size corresponding to 50% of the cumulative particle size distribution.

[0786] <Amount of fluorosurfactant in PVdF and VT powders>

[0787] ]Weigh 1 g of the powder separately, add 10 g (12.6 ml) of methanol, and perform ultrasonic treatment for 60 minutes to obtain an extract. The obtained extract is subjected to LC / MS / MS measurement. For the fluorine-containing compounds in the extract, a liquid chromatography mass spectrometer (Waters, LC-MS ACQUITY UPLC / TQD) is used for measurement. The measurement equipment configuration and LC-MS measurement conditions are shown in Table 1. An aqueous solution of a fluorine-containing compound with a known concentration is used to prepare aqueous solutions with 5 or more levels of content, and LC / MS analysis of each aqueous solution with different content is carried out. A calibration curve is plotted by graphing the relationship between the content and the area of the region corresponding to that content. Using the above calibration curve, the area of the region in the LC / MS chromatogram of the fluorine-containing compounds in the extract is converted into the content of the fluorine-containing compounds.

[0788] It should be noted that the detection limit in this measurement method is 10 mass ppb. [[ID=...]]

[0789] [Table 1] ]

[0790] <Mouney viscosity of fluoroelastomers (ML1+10 (121℃, 140℃))>

[0791] The determination was performed in accordance with ASTM D1646-15 and JIS K6300-1:2013.

[0792] Measuring instrument: MV2000E model manufactured by ALPHA TECHNOLOGIES

[0793] Rotor speed: 2 rpm

[0794] Measurement temperatures: 121℃, 140℃

[0795] Measurement time: After preheating for 1 minute, immediately rotate the rotor and measure the value after 10 minutes.

[0796] <Heat of Melting of Fluorinated Elastomers>

[0797] Using a differential scanning calorimeter (Hitachi Techno Science, X-DSC823e), 10 mg of sample was heated at 20 °C / min to obtain the DSC curve. The heat of fusion was calculated from the magnitude of the melting peak (ΔH) in the DSC curve.

[0798] <Glass transition temperature (Tg) of fluorinated elastomers>

[0799] Using a differential scanning calorimeter (Hitachi Techno Science, X-DSC823e), 10 mg of sample was heated at 20 °C / min to obtain the DSC curve. The temperature at which the extension of the baseline representing the second transition of the DSC curve intersects the tangent at the inflection point of the DSC curve is taken as the glass transition temperature.

[0800] <Weight-average molecular weight of fluorinated elastomers>

[0801] The determination was performed by gel permeation chromatography (GPC). A Tosoh AS-8010 or CO-8020 column (three GMHHR-H columns connected in series) and a Shimadzu RID-10A were used. Dimethylformamide (DMF) was added as a solvent at a flow rate of 1.0 ml / min, and the determination was performed using the measured data (reference: polystyrene).

[0802] Moisture content

[0803] The mass of approximately 20g of the polymer composition before and after heating at 150°C for 2 hours was determined and calculated using the following formula. Three samples were taken, and the mass was calculated separately. The average value was then used.

[0804] Moisture content (mass %) = [(mass of the polymer composition before heating (g)) - (mass of the polymer composition after heating (g))] / (mass of the polymer composition before heating (g)) × 100

[0805] <0.1% mass reduction temperature>

[0806] Approximately 10 mg of the polymer composition, which has not been heated to temperatures above 300°C, is accurately weighed and placed in a dedicated aluminum pan for TG-DTA (differential thermal-thermogravimetric analysis). The 0.1% mass reduction temperature is defined as the temperature at which a 0.1% mass reduction occurs when the aluminum pan is heated at 10°C / min in atmospheric conditions over a temperature range from 25°C to 600°C.

[0807] <1.0% mass reduction temperature>

[0808] Approximately 10 mg of the polymer composition, which has not been heated to temperatures above 300°C, is accurately weighed and placed in a dedicated aluminum pan for TG-DTA (differential thermal-thermogravimetric analysis). The 1.0% mass reduction temperature is defined as the temperature at which a 1.0% mass reduction occurs when the aluminum pan is heated at 10°C / min in atmospheric conditions over a temperature range from 25°C to 600°C.

[0809] Thermal Instability Index (TII)

[0810] The determination was made in accordance with ASTM D 4895-89.

[0811] <Content of specific fluorine compounds>

[0812] The determination was performed using liquid chromatography-mass spectrometry under the following conditions.

[0813] [Method for determining the content of compounds represented by general formula (1)]

[0814] Extract from the composition

[0815] Add 10 g (12.6 mL) of methanol to 1 g of the composition and sonicate for 60 minutes to extract the supernatant containing the compound represented by general formula (1). Concentrate the obtained extract by purging with nitrogen gas as appropriate to obtain a concentrated extract.

[0816] Determination of the content of compounds represented by general formula (1) in the extract

[0817] The content of the compound represented by general formula (1) in the extract was determined by conversion to perfluorooctanoic acid.

[0818] Calibration curve of perfluorooctanoic acid

[0819] Five methanol standard solutions of perfluorooctanoic acid (PFOA) with known concentrations ranging from 1 ng / mL to 100 ng / mL were prepared at five levels and analyzed using a Waters LC-MS ACQUITY UPLC / TQD. a and b were determined using a first approximation based on their respective sample concentrations and peak integrals, through the following relationship (1).

[0820] A = a × X + b (1)

[0821] A: Peak area of ​​perfluorooctanoic acid

[0822] X: Concentration of perfluorooctanoic acid (ng / mL)

[0823] Equipment composition and LC-MS measurement conditions

[0824] [Table 2]

[0825] MRM measurement parameters

[0826] [Table 3]

[0827] The content of compounds of general formula (1) with 4 to 20 carbon atoms in the extract.

[0828] Compounds of general formula (1) with 4 to 20 carbon atoms were determined using liquid chromatography-mass spectrometry. For the extracted liquid phase, the peak area of ​​compounds of general formula (1) with each number of carbon atoms was determined using the MRM method.

[0829] MRM measurement parameters

[0830] [Table 4]

[0831] The content of the compound represented by the general formula (1) with the number of carbon atoms (m+1) in the extract is calculated using the following formula (3). a and b in formula (3) are obtained from formula (1).

[0832] XCm=((ACm-b) / a)×((50×m+45) / 413) (3)

[0833] XCm: The concentration (ng / mL) of the compound represented by general formula (1) with the number of carbon atoms (m+1) in the extraction solution.

[0834] ACm: Peak area of ​​the compound represented by formula (1) with the number of carbon atoms (m+1) in the extraction solution.

[0835] The limit of quantitation in this assay is 1 ng / mL.

[0836] The content of compounds represented by general formula (1) with the number of carbon atoms (m+1) in the composition.

[0837] The content of the compound represented by the general formula (1) with the number of carbon atoms (m+1) in the composition is determined by the following formula (4).

[0838] YCm=XCm×12.6 (4)

[0839] YCm: The content (ppb, relative to TFE polymers) of the compound represented by the general formula (1) with the number of carbon atoms (m+1) in the composition.

[0840] The lower limit of quantitation is 10 ppb by mass.

[0841] [Method for determining the content of compounds represented by general formula (2)]

[0842] Extract from the composition

[0843] Add 10 g (12.6 mL) of methanol to 1 g of the composition and sonicate for 60 minutes to extract the supernatant containing the compound represented by general formula (2). Concentrate the obtained extract by purging with nitrogen gas as appropriate to obtain a concentrated extract.

[0844] Determination of the content of compounds represented by general formula (2) in the extract

[0845] The content of the compound represented by general formula (2) in the extract was determined by conversion to perfluorooctane sulfonic acid.

[0846] Calibration curve of perfluorooctane sulfonic acid

[0847] Five methanol standard solutions of perfluorooctane sulfonic acid with known concentrations ranging from 1 ng / mL to 100 ng / mL were prepared at five levels and analyzed using a liquid chromatography-mass spectrometry (Waters, LC-MS ACQUITY UPLC / TQD). a and b were determined using a first approximation based on their respective sample concentrations and peak integrals, through the following relationship (1).

[0848] A = a × X + b (1)

[0849] A: Peak area of ​​perfluorooctane sulfonic acid

[0850] X: Concentration of perfluorooctane sulfonic acid (ng / mL)

[0851] Equipment composition and LC-MS measurement conditions

[0852] [Table 5]

[0853] MRM measurement parameters

[0854] [Table 6]

[0855] The content of compounds of general formula (2) with 4 to 20 carbon atoms in the extract.

[0856] Compounds of general formula (2) with 4 to 20 carbon atoms were determined using liquid chromatography-mass spectrometry. For the extracted liquid phase, the peak area of ​​compounds of general formula (2) with each number of carbon atoms was determined using the MRM method.

[0857] MRM measurement parameters

[0858] [Table 7]

[0859] The content of the compound represented by the general formula (2) with the number of carbon atoms n in the extract is calculated using the following formula (3). a and b in formula (3) are obtained from formula (1).

[0860] XSn=((ASn-b) / a)×((50×n+81) / 499) (3)

[0861] XSn: The content (ng / mL) of the compound represented by the general formula (2) with the number of carbon atoms n in the extraction solution.

[0862] ASn: Peak area of ​​compounds with the general formula (2) representing the number of carbon atoms n in the extract solution.

[0863] The limit of quantitation in this assay is 1 ng / mL.

[0864] The content of compounds represented by the general formula (2) for the number of carbon atoms n in the composition.

[0865] The content of the compound represented by the general formula (2) with the number of carbon atoms n in the composition is determined by the following formula (4).

[0866] YSn=XSn×12.6 (4)

[0867] YSn: The content (ppb, relative to TFE polymer) of the compound represented by the general formula (2) with the number of carbon atoms n in the composition.

[0868] The lower limit of quantitation is 10 ppb by mass.

[0869] White solid A was obtained by the method described in Synthesis Example 1 of International Publication No. 2021 / 045228.

[0870] Preparation Example 1

[0871] Add 0.273g of lauric acid to 16g of deionized water, and slowly add 2.77g of ammonia solution (2.8% concentration) while stirring to obtain aqueous solution C.

[0872] Add 10g of lauric acid to 100g of deionized water, and slowly add 25g of a 10% ammonia solution while stirring to obtain aqueous solution D. The pH at this point is 9.6.

[0873] Manufacturing Example 1

[0874] 1748 g of deionized water, 90 g of paraffin, the aqueous solution C obtained in Preparation Example 1, and 0.5 g of ammonium oxalate were added to a 3 L SUS reactor equipped with a stirrer. The pH of the aqueous dispersion was 9.0 at this point. The reactor was sealed, and the system was purged with nitrogen to remove oxygen. The reactor was heated to 70 °C, and 2.0 g of HFP was added. The pressure was further increased using TFE to 2.70 MPa. A 0.5% (w / w) potassium permanganate aqueous solution was continuously added to the reactor as a polymerization initiator, resulting in a pressure drop and initiation of the reaction. TFE was added at a constant reaction pressure of 2.70 MPa. After 80 g of TFE was added, stirring was stopped, and depressurization was carried out until the reaction pressure reached atmospheric pressure.

[0875] Immediately fill the reactor with TFE to bring the reaction pressure to 2.70 MPa, and restart stirring to continue the reaction. Simultaneously, begin continuously adding the aqueous solution D obtained in Preparation Example 1 to the reactor. After adding 680 g of TFE, stop stirring and depressurize until the reactor reaches atmospheric pressure. At the end of the reaction, add 56.0 g of potassium permanganate aqueous solution and 26.2 g of aqueous solution D. Remove the aqueous dispersion from the reactor, cool it, and separate the paraffin wax to obtain an aqueous PTFE dispersion. The obtained aqueous PTFE dispersion has a pH of 8.8, a solids concentration of 27.1% by mass, and a primary particle size of 220 nm.

[0876] The obtained PTFE aqueous dispersion was diluted with deionized water to a solid content concentration of 13% by mass. After being vigorously stirred in a container with a stirrer to solidify, it was filtered with water to obtain a wet powder.

[0877] The obtained wet powder was placed in a stainless steel mesh tray and heat-treated in a hot air circulating electric furnace at 210°C. After 18 hours, the mesh tray was removed and air-cooled to obtain PTFE powder.

[0878] The obtained PTFE powder has a moisture content of 0.002% by mass, a standard specific gravity of 2.170, a thermal instability index of 44, an HFP content of 0.002% by mass, a reduction temperature of 391℃ for 0.1% by mass, and a reduction temperature of 491℃ for 1.0% by mass.

[0879] The obtained PTFE powder contains 67 ppb by mass of the compound represented by the general formula (1) with carbon number m (4-20) and less than 10 ppb by mass of the compound represented by the general formula (2) with carbon number n (4-20).

[0880] Manufacturing Example 2

[0881] 3580 g of deionized water and 7.56 g of white solid A were added to a 6 L SUS reactor equipped with a stirrer. The reactor contents were then heated to 70 °C while being evacuated and purged with TFE to remove oxygen, and the contents were stirred. 0.5 g of ethane and 71 g of perfluoropropyl vinyl ether (PPVE) were added to the reactor, followed by the addition of TFE until the pressure reached 2.4 MPaG. 306 mg of ammonium persulfate (APS) initiator dissolved in 20 g of deionized water was injected into the reactor. A pressure drop occurred after the initiator injection, indicating the start of polymerization. TFE was added to the reactor to maintain a constant pressure of 2.4 MPaG. After polymerization began, 108 mg of ammonium persulfate and 84 g of PPVE were continuously added. The TFE supply was stopped when approximately 1600 g of TFE was consumed in the reaction, and stirring was ceased to terminate the reaction. Afterwards, the pressure inside the reactor is vented until it reaches atmospheric pressure, thus obtaining PFA aqueous dispersion 1.

[0882] The PFA aqueous dispersion 1 was removed from the reactor and cooled to the atmosphere to obtain PFA aqueous dispersion 2. The solid content concentration of the obtained PFA aqueous dispersion 2 was 30.5% by mass.

[0883] The obtained PFA aqueous dispersion 2 was stirred, precipitated and dried to obtain PFA powder.

[0884] The obtained PFA powder had a PPVE content of 6.5% by mass, an MFR of 2.1 g / 10 min, and a melting point of 295 °C.

[0885] Manufacturing Example 3

[0886] 655L of deionized water and 6kg of white solid A were added to a 1000L SUS reactor equipped with a stirrer. Nitrogen replacement and vacuum degassing were performed to remove oxygen from the reactor, and the contents were stirred. Then, 100kg of HFP monomer was added, followed by a mixture of TFE and HFP monomers (TFE:HFP = 86:14 (mass%)). While stirring, the temperature was increased to 95°C, and the pressure was raised to 1.5 MPaG. 70kg of a 10% (mass) ammonium persulfate (APS) aqueous solution was added as an initiator to begin the reaction. The mixed monomers were continuously supplied to maintain a pressure of 1.5 MPaG in the reaction system. After 30 minutes of reaction, stirring was stopped, the reaction was terminated, and the gas in the reactor was released to atmospheric pressure, yielding an aqueous dispersion of the TFE / HFP binary polymer. The solid content of the obtained TFE / HFP binary polymer aqueous dispersion was 4.5% (mass).

[0887] In addition, 600 L of deionized water and 20 kg of the aforementioned binary polymer emulsion dispersion were added to the same SUS reactor for nitrogen replacement and vacuum degassing to remove oxygen from the reactor, and the contents were stirred. Then, 138 kg of HFP monomer and 4 kg of PPVE were added, and the temperature was increased while stirring to bring the reactor contents to 95°C. A mixture of TFE and HFP monomers (TFE:HFP = 87.3:12.7 (mass%)) was then added, thereby pressurizing to 4.2 MPaG. 2.8 kg of a 10% (mass) APS aqueous solution was added as an initiator to start the reaction. After the reaction started, a 10% (mass) APS aqueous solution was continuously added at a rate of approximately 20 g / min. During the reaction, 180 g of PPVE was added each time when the amount of the above-mentioned mixed monomers reached 25%, 50%, and 75% of the total supplied monomers. The above-mentioned mixed monomers were continuously supplied in a manner that maintained the pressure in the reaction system at 4.2 MPaG. Fifty-one minutes after the start of the reaction, the addition of 10% (w / w) APS aqueous solution was stopped, stirring was stopped, and the reaction was terminated. The gas in the reactor was released to atmospheric pressure, yielding an aqueous dispersion of TFE / HFP / PPVE FEP. The solid content of the obtained TFE / HFP / PPVE FEP aqueous dispersion was 20.2% (w / w).

[0888] The obtained polymer had an MFR of 35.7 g / 10 min, a composition ratio (mass %) of TFE / HFP / PPVE = 87.6 / 11.5 / 0.9, and a melting point of 257 °C.

[0889] Manufacturing Example 4

[0890] Referring to Example 1 of Japanese Patent Application Publication No. 2014-141673, an aqueous dispersion of PVdF was obtained. Specifically, 1700 g of pure water, 0.85 g of H-(CF2CF2)3-CH2-O-CO-CH2CH(-SO3Na)-CO-O-CH2-(CF2CF2)3-H (surface tension 22 mN / m) as a fluorinated surfactant, and 17 g of paraffin were added to a 3.0 L SUS reactor for nitrogen replacement to remove oxygen. Then, 150 g of vinylidene fluoride (VdF) was added, and the reactor temperature was raised to 115 °C. While stirring the contents, 0.5 g of acetone and 5.6 g of di-tert-butyl peroxide were added to initiate the reaction. 427 g of vinylidene fluoride was added over 9 hours while maintaining the pressure at 4.0 MPaG in the tank. 1.45 g of H-(CF2CF2)3-CH2-O-CO-CH2CH(-SO3Na)-CO-O-CH2-(CF2CF2)3-H was added midway through the reaction to obtain an aqueous dispersion of PVdF.

[0891] The solid content of the obtained PVdF aqueous dispersion was 20.6% by mass.

[0892] The obtained PVdF aqueous dispersion was precipitated, dried at 120℃, and pulverized to obtain PVdF powder.

[0893] PVdF has a melting point of 161℃, an average particle size of 1.1μm, and contains 110 ppb of fluorinated surfactant.

[0894] Manufacturing Example 5

[0895] 1.3 kg of pure water was added to a 4 L reactor for nitrogen replacement to remove oxygen. Then, 0.88 kg of octafluorocyclobutane was added, and the system was brought to 37 °C and stirred. Next, a mixed gas with a TFE / VdF ratio of 5 / 95 mol% was added until the system pressure reached 1.3 MPaG. Then, 1.5 g of a 50% (w / w) methanol solution of di-n-propyl peroxide was added to initiate the reaction. As the reaction proceeded, the system pressure decreased; therefore, a mixed gas with a TFE / VdF ratio of 15 / 85 mol% was continuously supplied to maintain the system pressure at 1.3 MPaG. The reaction was continued for 44 hours. Stirring was stopped to stop the reaction. After depressurization and restoration to atmospheric pressure, the reaction product was washed with water and dried at 120 °C to obtain a white powder. The obtained white powder was pulverized using a high-speed mill to obtain VT powder.

[0896] The obtained VT powder has a melting point of 136℃, a composition ratio of VdF / TFE=85.0 / 15.0 (mol%), a weight-average molecular weight of 1,100,000, and an average particle size of 1.0 μm.

[0897] Because no fluorinated surfactants are used, it does not contain fluorinated surfactants.

[0898] Manufacturing Example 6

[0899] In a 3L SUS polymerization tank equipped with a stirrer, 1500g of deionized water, 4.8g of white solid A (as a fluorinated surfactant), and 0.3g of CH2=CFCF2OCF(CF3)CF2OCF(CF3)COONH4 were added and the tank was sealed. After purging the tank with nitrogen, a vacuum was created, and 400cc of isopropanol (as a chain transfer agent) was added using a syringe while the vacuum was being created. Then, while stirring at 70°C, a mixed gaseous monomer with a VdF / TFE ratio of 67 / 33 mol% was added to the tank until the pressure reached 0.8 MPaG. The reaction was then initiated by pressurizing an aqueous solution containing 0.15g of ammonium persulfate with nitrogen. To maintain the tank pressure, additional VdF / TFE mixed monomers with a ratio of 67 / 33 mol% were added. Stirring was stopped when 346g of monomer was added, the gas in the tank was released, and the reaction was terminated. The tank was cooled to obtain an aqueous dispersion of VT. The solid content of the obtained VT aqueous dispersion was 20% by mass.

[0900] It should be noted that the composition ratio of the obtained VT aqueous dispersion is VdF / TFE = 67.0 / 33.0 (mol%), the weight-average molecular weight is 1,300,000, and the melting point is 160℃.

[0901] In addition, the obtained VT aqueous dispersion was stirred, precipitated, and dried at 120°C to obtain a powder. The obtained powder was then pulverized using a high-speed mill to obtain VT powder.

[0902] The obtained VT powder has an average particle size of 1.1 μm and contains 340 ppb of fluorinated surfactant.

[0903] Manufacturing Example 7

[0904] 1650 ml of pure water was added to a 3 L SUS autoclave for nitrogen purging. Hexafluoropropylene (HFP) was used for micro-pressurization, and the temperature was adjusted to 80 °C while stirring. HFP was added until the pressure reached 0.23 MPaG, followed by the addition of a monomeric mixture of vinylidene fluoride (VdF) and HFP in a molar ratio of 78.2 / 21.8 until the pressure reached 1.472 MPaG. 0.097 ml of 2-methylbutane was added under nitrogen pressure. 36.4 g of ammonium persulfate was dissolved in 80 ml of pure water, and the resulting solution was added under nitrogen pressure to initiate the reaction. When the pressure dropped to 1.44 MPaG, the pressure was increased to 1.50 MPaG using a continuous monomer and maintained. After approximately 9.3 hours of reaction, 607 g of the continuous monomer was added, stirring was stopped, the gas in the autoclave was released, and the mixture was cooled. 2299 g of the dispersion was recovered. The solids concentration of the obtained aqueous elastomer dispersion was 26.9% by mass.

[0905] The resulting elastomer had a composition of VdF / HFP = 77.9 / 22.1 (mol%). The Mooney viscosity (ML1+10 (140℃)) of the resulting elastomer was 77, the weight-average molecular weight was 850,000, and the Tg via DSC was -18℃. Furthermore, no heat of fusion was detected during the second heating.

[0906] Manufacturing Example 8

[0907] In a 6-liter SUS reactor equipped with SUS stirring blades and a temperature control jacket, 3480 g of deionized water, 100 g of paraffin wax, and 5.3 g of white solid A were added. The mixture was heated to 70°C while oxygen was removed by displacing the reactor with nitrogen. TFE was then injected to bring the system pressure to 0.78 MPaG, and the temperature was maintained at 70°C with stirring. Next, an aqueous solution containing 15.0 mg of ammonium persulfate dissolved in 20 g of water was injected with TFE to initiate the polymerization reaction. As the polymerization proceeded, the system pressure decreased; additional TFE was added to maintain the temperature at 70°C and the pressure at 0.78 MPaG.

[0908] At the point when 400g of TFE had been consumed since the start of polymerization, TFE was pressurized into an aqueous solution containing 18.0mg of hydroquinone as a free radical scavenger, dissolved in 20g of water. Polymerization continued until approximately 1200g of TFE had been added, at which point stirring and TFE supply were stopped, and the gas in the system was immediately released to bring the pressure to atmospheric level, thus ending the polymerization reaction. The aqueous dispersion was removed, cooled, and the paraffin was separated to obtain an aqueous PTFE dispersion. The average primary particle size of the obtained aqueous PTFE dispersion was 310nm, and the solids concentration was 25.3% by mass.

[0909] The obtained PTFE aqueous dispersion was precipitated and dried to obtain PTFE powder.

[0910] The obtained PTFE powder has an SSG of 2.156 and an endothermic peak temperature of 343℃.

[0911] Preparation Example 2

[0912] A mixture of 10-undecen-1-ol (16 g), 1,4-benzoquinone (10.2 g), DMF (160 mL), water (16 mL), and PdCl2 (0.34 g) was heated and stirred at 90 °C for 12 hours.

[0913] The solvent was then removed by distillation under reduced pressure. The resulting residue was purified by separation and column chromatography to give 11-hydroxyundecane-2-one (15.4 g).

[0914] A mixture of 11-hydroxyundecane-2-one (13 g), sulfur trioxide triethylamine complex (13.9 g), and tetrahydrofuran (140 mL) was stirred at 50 °C for 12 hours. A sodium methoxide (3.8 g) / methanol (12 mL) solution was added dropwise to the reaction mixture.

[0915] The precipitated solid was filtered under reduced pressure and washed with ethyl acetate to obtain sodium 10-oxoundecyl sulfate (15.5 g) (hereinafter referred to as surfactant A).

[0916] 588.6 g of deionized water and 70.0 g of surfactant A were added to a 1 L glass reactor equipped with a stirrer. The reactor was sealed, and the system was purged with nitrogen to remove oxygen. The reactor was heated to 90 °C and pressurized to 0.4 MPaG with nitrogen. 41.4 g of ammonium persulfate (APS) was added, and the mixture was stirred for 3 hours. Stirring was stopped, and the reactor was depressurized to atmospheric pressure and cooled to obtain an aqueous solution of surfactant B.

[0917] Manufacturing Example 9

[0918] In a 6L SUS reactor equipped with a stirrer, 3600g of deionized water, 180g of paraffin wax, and 0.540g of surfactant A were added. The reactor was sealed, and the system was purged with nitrogen to remove oxygen. The reactor was heated to 70°C, and TFE was added to bring the reactor pressure to 2.70MPa. 0.620g of ammonium persulfate (APS) and 1.488g of succinyl peroxide (DSP) were added as polymerization initiators. TFE was added at a constant reaction pressure of 2.70MPa. Simultaneously with the addition of TFE, an aqueous solution of surfactant B was continuously added. When 540g of TFE had been added, 20g of deionized water containing 0.76g of hydroquinone was added. Stirring was stopped when 1200g of TFE had been added, and the pressure was depressurized until the reactor reached atmospheric pressure. 103g of surfactant aqueous solution B was added to terminate the reaction. The contents were removed from the reactor, cooled, and the paraffin wax was separated to obtain an aqueous dispersion B of the TFE-based polymer.

[0919] The obtained TFE-based polymer aqueous dispersion B has a solid content of 25.9% by mass and an average primary particle size of 290 nm.

[0920] The obtained TFE-based polymer aqueous dispersion B was diluted with deionized water to a solid content concentration of 13% by mass. After being vigorously stirred in a container with a stirrer to solidify, it was filtered with water to obtain a wet powder.

[0921] The obtained wet powder was placed in a stainless steel mesh tray and heat-treated in a hot air circulating electric furnace at 210°C. After 18 hours, the mesh tray was removed and air-cooled to obtain PTFE powder.

[0922] The obtained PTFE powder has a moisture content of 0.003% by mass, a standard specific gravity of 2.151, a thermal instability index of 42, a 0.1% by mass reduction temperature of 397℃, and a 1.0% by mass reduction temperature of 492℃.

[0923] Compounds of general formula (1) with carbon atoms m=15 and 16 were detected in the obtained PTFE powder. The content of the compound of general formula (1) with carbon atoms m=15 was 73 ppb by mass, and the content of the compound of general formula (1) with carbon atoms m=16 was 141 ppb by mass. In addition, compounds of general formula (2) with carbon atoms n=4, 6, 8, 10, 12 and 14 were detected. The content of the compound of general formula (2) with carbon atoms n=8 was 1413 ppb by mass.

[0924] Production example 1

[0925] 886g of the PTFE aqueous dispersion obtained in Manufacturing Example 1 and 197g of the PFA aqueous dispersion 2 obtained in Manufacturing Example 2 were placed in a container and diluted with deionized water to a solid component concentration of 13% by mass. The PTFE / PFA mixture was co-precipitated while being stirred at high speed, and then filtered with water to obtain a wet powder.

[0926] The obtained wet powder was placed in a stainless steel mesh tray and heat-treated in a hot air circulating electric furnace at 240°C. After 20 hours, the mesh tray was removed and allowed to air cool, yielding a PTFE / PFA mixed powder. The mixing ratio (mass ratio) of the obtained PTFE / PFA mixed powder was PTFE / PFA = 80 / 20.

[0927] The obtained PTFE / PFA mixed powder is used as polymer composition A.

[0928] The endothermic peak temperatures of polymer composition A are 295℃ and 342℃, the thermal instability index is 56, the temperature decreases by 0.1% by mass at 385℃, the temperature decreases by 1.0% by mass at 486℃, and the moisture content is 0.000% by mass.

[0929] The polymer composition A contains less than 10 ppb by mass of the compound represented by general formula (1) with the number of carbon atoms m (4-20) and less than 10 ppb by mass of the compound represented by general formula (2) with the number of carbon atoms n (4-20).

[0930] Production example 2

[0931] 886g of the PTFE aqueous dispersion obtained in Manufacturing Example 1 and 297g of the FEP aqueous dispersion obtained in Manufacturing Example 3 were placed in a container and diluted with deionized water to a solid content concentration of 13% by mass. The PTFE / FEP mixture was co-precipitated while being stirred at high speed, and then filtered with water to obtain a wet powder.

[0932] The obtained wet powder was placed in a stainless steel mesh tray and heat-treated in a hot air circulating electric furnace at 210°C. After 20 hours, the mesh tray was removed and allowed to air cool, yielding a PTFE / FEP mixed powder. The mixing ratio (mass ratio) of the obtained PTFE / FEP mixed powder was PTFE / FEP = 80 / 20.

[0933] The obtained PTFE / FEP mixed powder was used as polymer composition B.

[0934] The endothermic peak temperatures of polymer composition B are 257℃ and 342℃, the thermal instability index is 64, the temperature decreases by 0.1% by mass at 382℃, the temperature decreases by 1.0% by mass at 484℃, and the moisture content is 0.000% by mass.

[0935] The polymer composition B contains a compound of formula (1) with a number of carbon atoms m (4-20) containing 67 ppb by mass, and a compound of formula (2) with a number of carbon atoms n (4-20) containing less than 10 ppb by mass.

[0936] Production example 3

[0937] 775g of the aqueous PTFE dispersion obtained in Manufacturing Example 1 and 437g of the aqueous PVdF dispersion obtained in Manufacturing Example 4 were placed in a container and diluted with deionized water to a solid content concentration of 13% by mass. Nitric acid was added as a precipitant, and the PTFE / PVdF mixture was co-precipitated while stirring. After filtration with water, a wet powder was obtained.

[0938] The obtained wet powder was placed in a stainless steel mesh tray and heat-treated in a hot air circulating electric furnace at 120°C. After 30 hours, the mesh tray was removed and allowed to air cool, yielding a PTFE / PVdF mixed powder. The mixing ratio (mass ratio) of the obtained PTFE / PVdF mixed powder was PTFE / PVdF = 70 / 30.

[0939] The obtained PTFE / PVdF mixed powder was used as polymer composition C.

[0940] The endothermic peak temperatures of polymer composition C are 161℃ and 342℃, and the moisture content is 0.003 by mass.

[0941] The polymer composition C contains a compound of general formula (1) with a number of carbon atoms m (4-20) containing 3786 ppb by mass, and a compound of general formula (2) with a number of carbon atoms n (4-20) containing less than 10 ppb by mass.

[0942] Production example 4

[0943] 886g of the PTFE aqueous dispersion obtained in Manufacturing Example 1, 60g of the VT powder obtained in Manufacturing Example 5, and 960g of deionized water were placed in a container. Nitric acid, used as a precipitating agent, was added, and co-precipitation and drying were carried out in the same manner as in Manufacturing Example 3, with stirring, to obtain a mixed powder. The mixing ratio (mass ratio) of the obtained PTFE / VT mixed powder was PTFE / VT = 80 / 20.

[0944] The obtained PTFE / VT mixed powder was used as polymer composition D.

[0945] The endothermic peak temperatures of polymer composition D are 136℃ and 342℃, the moisture content is 0.005% by mass, the average aspect ratio is 1.1, and the PTFE powder has not undergone fibrillation.

[0946] The polymer composition D contains a compound of formula (1) with a number of carbon atoms m (4-20) containing 4326 ppb by mass, and a compound of formula (2) with a number of carbon atoms n (4-20) containing less than 10 ppb by mass.

[0947] Production example 5

[0948] 996g of the PTFE aqueous dispersion obtained in Manufacturing Example 1, 30g of the VT powder obtained in Manufacturing Example 6, and 1080g of deionized water were placed in a container. Nitric acid, used as a precipitating agent, was added, and co-precipitation and drying were carried out in the same manner as in Manufacturing Example 3 while stirring to obtain a mixed powder. The mixing ratio (mass ratio) of the obtained PTFE / VT mixed powder was PTFE / VT = 90 / 10.

[0949] The obtained PTFE / VT mixed powder is used as polymer composition E.

[0950] The endothermic peak temperatures of polymer composition E are 160℃ and 342℃, the moisture content is 0.003% by mass, the average aspect ratio is 1.2, and the PTFE powder has not undergone fibrillation.

[0951] The polymer composition E contains a compound of general formula (1) with a number of carbon atoms m (4-20) containing 4867 ppb by mass, and a compound of general formula (2) with a number of carbon atoms n (4-20) containing less than 10 ppb by mass.

[0952] Production example 6

[0953] 135g of PTFE powder obtained in Manufacturing Example 1 and 15g of VT powder obtained in Manufacturing Example 6 were placed in a V-type mixer (VK-1, manufactured by Irie Shokai Co., Ltd.) and mixed at 30 rpm for 10 minutes. The resulting PTFE / VT mixed powder had a mixing ratio (mass ratio) of PTFE / VT = 90 / 10.

[0954] The obtained PTFE / VT mixed powder is used as polymer composition F.

[0955] The endothermic peak temperatures of polymer composition F are 160℃ and 342℃, the moisture content is 0.001% by mass, the average aspect ratio is 1.5, and the PTFE powder has not undergone fibrillation.

[0956] The polymer composition F contains a compound of general formula (1) with a carbon number m (4-20) of 60 ppb by mass, and a compound of general formula (2) with a carbon number n (4-20) of less than 10 ppb by mass.

[0957] Production example 7

[0958] 886g of the PTFE aqueous dispersion obtained in Manufacturing Example 1 and 223g of the elastomer aqueous dispersion obtained in Manufacturing Example 7 were placed in a container and diluted with deionized water to a solid component concentration of 15% by mass. Nitric acid was added as a precipitant, and the PTFE / elastomer mixture was co-precipitated while stirring at high speed. After filtration with water, a wet powder was obtained.

[0959] The obtained wet powder was placed in a stainless steel mesh tray and heat-treated in a hot air circulating electric furnace at 120°C. After 30 hours, the mesh tray was removed and allowed to air cool, yielding a PTFE / elastomer mixed powder. The mixing ratio (mass ratio) of the obtained PTFE / elastomer mixed powder was PTFE / elastomer = 80 / 20.

[0960] The obtained PTFE / elastomer mixed powder is used as polymer composition G.

[0961] The endothermic peak temperature of polymer composition G is 342℃, the moisture content is 0.005% by mass, the average aspect ratio is 1.1, and the PTFE powder has not undergone fibrillation.

[0962] The polymer composition G contains a compound of formula (1) with a number of carbon atoms m (4-20) containing 4846 ppb by mass, and a compound of formula (2) with a number of carbon atoms n (4-20) containing less than 10 ppb by mass.

[0963] Production example 8

[0964] 830g of the aqueous PTFE dispersion obtained in Manufacturing Example 8 and 437g of the aqueous PVdF dispersion obtained in Manufacturing Example 4 were placed in a container and diluted with deionized water to a solid content concentration of 13% by mass. Nitric acid was added as a precipitant, and the PTFE / PVdF mixture was co-precipitated while stirring. After filtration with water, a wet powder was obtained.

[0965] The obtained wet powder was placed in a stainless steel mesh tray and heat-treated in a hot air circulating electric furnace at 120°C. After 30 hours, the mesh tray was removed and allowed to air cool, yielding a PTFE / PVdF mixed powder. The mixing ratio (mass ratio) of the obtained PTFE / PVdF mixed powder was PTFE / PVdF = 70 / 30.

[0966] The obtained PTFE / PVdF mixed powder was used as polymer composition X.

[0967] The endothermic peak temperatures of polymer composition X are 161℃ and 343℃, the moisture content is 0.003% by mass, the average aspect ratio is 1.1, and the PTFE powder has not undergone fibrillation.

[0968] The polymer composition X uses PTFE without the use of hydrocarbon surfactants and therefore does not contain the compounds shown in general formulas (1) and (2).

[0969] Therefore, the content of the compound represented by the general formula (1) with the number of carbon atoms m (4-20) in the polymer composition X is less than 10 ppb by mass, and the content of the compound represented by the general formula (2) with the number of carbon atoms n (4-20) is less than 10 ppb by mass.

[0970] Production example 9

[0971] 811g of the aqueous PTFE dispersion obtained in Manufacturing Example 9 and 437g of the aqueous PVdF dispersion obtained in Manufacturing Example 4 were placed in a container and diluted with deionized water to a solid content concentration of 13% by mass. Nitric acid was added as a precipitant, and the PTFE / PVdF mixture was co-precipitated while sti...

Claims

1. A polymer composition for use as an adhesive in electrochemical devices, comprising a fibrillable polymer, a thermoplastic polymer, and at least one compound selected from the group consisting of compounds represented by general formula (1) and general formula (2). General formula (1): (H-(CF2)) m-1 -COO) p M 1 In the formula, m ranges from 4 to 20, and M... 1 For H, metal atoms, NR 5 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphorium with or without substituents, where p is 1 or 2, wherein... R 5 Whether the groups are the same or different, they are H or organic groups with 1 to 10 carbon atoms. General formula (2): (H-(CF2)) n -SO3) q M 2 In the formula, n is 4 to 20, M 2 For H, metal atoms, NR 5 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, where q is 1 or 2, and R 5 Same as above.

2. A polymer composition for use as an adhesive in electrochemical devices, comprising a fibrillated polymer and a thermoplastic polymer, wherein the fibrillated polymer has a thermal instability index (TII) of 10 or higher.

3. The polymer composition according to claim 1 or 2, wherein, The fibrillable polymer is at least one selected from the group consisting of homopolymers of tetrafluoroethylene and modified polytetrafluoroethylene composed only of tetrafluoroethylene units and hexafluoropropylene-based polymeric units.

4. The polymer composition according to any one of claims 1 to 3, wherein, The content of the fibrillable polymer is more than 50% by mass and less than 97% by mass relative to the polymer composition.

5. The polymer composition according to any one of claims 1 to 4, wherein, The thermoplastic polymer is at least one vinylidene fluoride-based polymer selected from the group consisting of polyvinylidene fluoride and vinylidene fluoride / tetrafluoroethylene copolymers.

6. The polymer composition according to any one of claims 1 to 5, wherein it is in the form of a powder.

7. The polymer composition according to any one of claims 1 to 6, used as a binder for lithium-ion secondary batteries.

8. An adhesive for electrochemical devices, which is substantially composed solely of a polymer composition, wherein, The polymer composition comprises a fibrillable polymer, a thermoplastic polymer, and at least one compound selected from the group consisting of compounds represented by general formula (1) and general formula (2). General formula (1): (H-(CF2)) m-1 -COO) p M 1 In the formula, m ranges from 4 to 20, and M... 1 For H, metal atoms, NR 5 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphorium with or without substituents, where p is 1 or 2, and R 5 Whether the groups are the same or different, they are H or organic groups with 1 to 10 carbon atoms. General formula (2): (H-(CF2)) n -SO3) q M 2 In the formula, n is 4 to 20, M 2 For H, metal atoms, NR 5 4. Imidazolium with or without substituents, pyridinium with or without substituents, or phosphonium with or without substituents, where q is 1 or 2, and R 5 Same as above.

9. An adhesive for electrochemical devices, which is substantially composed solely of a polymer composition, wherein, The polymer composition comprises a fibrillating polymer and a thermoplastic polymer, wherein the fibrillating polymer has a thermal instability index (TII) of 10 or higher.

10. The adhesive for electrochemical devices as described in claim 8 or 9, wherein, The polymer composition exhibits endothermic peaks in regions below and above 330°C.

11. The adhesive for electrochemical devices according to any one of claims 8 to 10, wherein, The endothermic peak temperature of the fibrillable polymer exceeds 330°C.

12. The adhesive for electrochemical devices according to any one of claims 8 to 11, wherein, The fibrillating polymer is a tetrafluoroethylene-based polymer.

13. The adhesive for electrochemical devices according to any one of claims 8 to 12, wherein, The fibrillable polymer is at least one selected from the group consisting of homopolymers of tetrafluoroethylene and modified polytetrafluoroethylene composed only of tetrafluoroethylene units and hexafluoropropylene-based polymeric units.

14. The adhesive for electrochemical devices according to any one of claims 8, 10-13, wherein, The thermal instability index (TII) of the fibrillable polymer is greater than 10.

15. The adhesive for electrochemical devices according to any one of claims 8 to 14, wherein, The amount of the thermoplastic polymer is less than 50% by mass relative to the polymer composition.

16. The adhesive for electrochemical devices according to any one of claims 8 to 15, wherein, The content of the fibrillable polymer is more than 50% by mass and less than 97% by mass relative to the polymer composition.

17. The adhesive for electrochemical devices according to any one of claims 8 to 16, wherein, The polymer composition has a 0.1% mass reduction temperature of 340°C or higher.

18. The adhesive for electrochemical devices according to any one of claims 8 to 17, wherein, The polymer composition has a 1.0% mass reduction temperature of 370°C or higher.

19. The adhesive for electrochemical devices according to any one of claims 8 to 16, wherein, The thermoplastic polymer is a vinylidene fluoride-based polymer.

20. The adhesive for electrochemical devices as described in claim 19, wherein, The vinylidene fluoride polymer is a fluorinated elastomer.

21. The adhesive for electrochemical devices as described in claim 20, wherein, The fluorinated elastomer comprises vinylidene fluoride units and other monomer units capable of copolymerizing with vinylidene fluoride.

22. The adhesive for electrochemical devices as described in claim 20 or 21, wherein, The fluorinated elastomer is selected from at least one of the following groups: vinylidene fluoride / hexafluoropropylene copolymer, vinylidene fluoride / 2,3,3,3-tetrafluoropropylene copolymer, and vinylidene fluoride / tetrafluoroethylene / hexafluoropropylene copolymer.

23. The adhesive for electrochemical devices according to any one of claims 8 to 16, wherein, The polymer composition has an endothermic peak in the region of at least 130°C to 200°C.

24. The adhesive for electrochemical devices according to any one of claims 8 to 16, wherein, The thermoplastic polymer is at least one vinylidene fluoride-based polymer selected from the group consisting of polyvinylidene fluoride and vinylidene fluoride / tetrafluoroethylene copolymers.

25. The adhesive for electrochemical devices as described in claim 24, wherein, The average particle size of the vinylidene fluoride polymer is less than 10 μm, and it does not contain fluorinated surfactants.

26. The adhesive for electrochemical devices according to any one of claims 8 to 25, wherein, The polymer composition has an average aspect ratio of 2.5 or less in powder form.

27. The adhesive for electrochemical devices according to any one of claims 8 to 26, wherein, The powder of the fibrillable polymer did not undergo fibrillation.

28. The binder for electrochemical devices as described in any one of claims 8 to 27, wherein it is a powder.

29. The binder for electrochemical devices as described in any one of claims 8 to 28, wherein it is a binder for lithium-ion secondary batteries.

30. An electrode binder comprising a polymer composition according to any one of claims 1 to 7 or an electrochemical device binder and an electrode active substance according to any one of claims 8 to 29.

31. The electrode mixture as described in claim 30, wherein it is in the form of a sheet.

32. An electrode comprising a polymer composition according to any one of claims 1 to 7 or an electrochemical device binder, an electrode active material, and a current collector according to any one of claims 8 to 29.

33. A secondary battery comprising the electrode as described in claim 32.

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