Method for producing metal fluoride, and composition

Abstract

The purpose of the present disclosure is to provide: a method for producing a metal fluoride; and a composition, whereby it is possible to produce the metal fluoride while suppressing the generation of a corrosive gas. The present disclosure relates to a method for producing a metal fluoride, the method comprising: a step (1) for subjecting a fluorine-containing compound and a basic metal compound containing at least one selected from the group consisting of alkali metals and alkaline earth metals to a mechanochemical treatment to obtain a composition containing the fluorine-containing compound and the basic metal compound; and a step (2) for heat-treating the composition to obtain a metal fluoride containing at least one selected from the group consisting of alkali metals and alkaline earth metals.　

Description

METHOD FOR PRODUCING METAL FLUORIDE AND COMPOSITION

[0001] The present disclosure relates to methods and compositions for producing metal fluorides.

[0002] After mixing the compression-molded polytetrafluoroethylene with calcium oxide, 400 to 500 kg / cm ２ A method for obtaining calcium fluoride by heating the mixture at a temperature of 390 to 410°C under a pressure of 1000 kJ / cm 2 is known (see, for example, Patent Document 1).

[0003] Russian Patent No. 2656488

[0004] However, the conventional method has a problem in that a large amount of corrosive gas such as hydrogen fluoride is generated during heating.

[0005] An object of the present disclosure is to provide a method for producing a metal fluoride and a composition that can produce a metal fluoride while suppressing the generation of corrosive gases.

[0006] The present disclosure (1) is a method for producing a metal fluoride, comprising: a step (1) of mechanochemically treating a fluorine-containing compound and a basic metal compound containing at least one selected from the group consisting of alkali metals and alkaline earth metals to obtain a composition containing the fluorine-containing compound and the basic metal compound; and a step (2) of heat-treating the composition to obtain a metal fluoride containing at least one selected from the group consisting of alkali metals and alkaline earth metals.

[0007] The present disclosure (2) is the manufacturing method according to the present disclosure (1), wherein the energy in the mechanochemical treatment is 0.1 J / s / g or more.

[0008] The present disclosure (3) is the manufacturing method according to the present disclosure (1) or (2), wherein the energy in the mechanochemical treatment is 0.5 to 10 J / s / g.

[0009] The present disclosure (4) is a manufacturing method of any combination with any of the present disclosures (1) to (3), in which the cumulative energy in the mechanochemical treatment is 3000 J / g or more.

[0010] The present disclosure (5) is a manufacturing method of any combination with any of the present disclosures (1) to (4), in which the cumulative energy in the mechanochemical treatment is 3800 to 400,000 J / g.

[0011] The present disclosure (6) is a manufacturing method in which the mechanochemical treatment is carried out using a planetary mill or a vibratory mill, and is any combination of this disclosure (1) to (5).

[0012] The present disclosure (7) is a manufacturing method of any combination with any of the present disclosures (1) to (6), in which the temperature of the heat treatment is 300° C. or higher.

[0013] The present disclosure (8) is a manufacturing method of any combination with any of the present disclosures (1) to (7), in which the temperature of the heat treatment is 300 to 800°C.

[0014] The present disclosure (9) is a manufacturing method for any combination with any of the present disclosures (1) to (8), in which the heat treatment time is 10 minutes to 100 hours.

[0015] The present disclosure (10) is a method for producing any combination of the present disclosures (1) to (9), in which the basic metal compound is at least one selected from the group consisting of a basic metal oxide, a basic metal hydroxide, and a basic metal carbonate.

[0016] The present disclosure (11) is a method for producing any combination of the present disclosures (1) to (10), in which the basic metal compound is a basic metal compound containing magnesium or calcium.

[0017] The present disclosure (12) is a method for producing any combination of the present disclosures (1) to (11), in which the basic metal compound is at least one selected from the group consisting of calcium carbonate, calcium oxide, calcium hydroxide, magnesium oxide, and magnesium hydroxide.

[0018] The present disclosure (13) is a method for producing any combination of the present disclosures (1) to (12) in which the fluorine-containing compound is a fluorine-containing polymer.

[0019] The present disclosure (14) is a method for producing any combination of the present disclosures (1) to (13), in which the fluorine-containing compound is at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, polydifluoroethylene, ethylene / tetrafluoroethylene copolymer, and fluororubber.

[0020] The present disclosure (15) is a production method of any combination with any of the present disclosures (1) to (14), in which the mixing ratio of the basic metal compound is 1 to 10 equivalents per equivalent of the fluorine-containing compound.

[0021] The present disclosure (16) is a production method of any combination with any of the present disclosures (1) to (15), in which the mixing ratio of the basic metal compound is 1 to 4 equivalents per equivalent of the fluorine-containing compound.

[0022] The present disclosure (17) is a composition comprising a fluorine-containing compound and a basic metal compound containing at least one selected from the group consisting of alkali metals and alkaline earth metals, wherein the amount of fluoride ions generated when heated at 600°C for 1 hour is 15 mass% or less relative to the fluorine-containing compound, and the basic metal compound is at least one selected from the group consisting of basic metal carbonates and basic metal hydroxides.

[0023] The present disclosure (18) is the composition according to the present disclosure (17), in which the content of the fluorine-containing compound is 10% by mass or more.

[0024] The present disclosure (19) is the composition according to the present disclosure (17) or (18), wherein the content of the fluorine-containing compound is 10 to 40 mass%.

[0025] The present disclosure (20) is a composition of any combination with any of the present disclosures (17) to (19), in which the content of the basic metal compound is 65 to 90 mass%.

[0026] The present disclosure (21) is a composition in any combination with any of the present disclosures (17) to (20), in which the ratio of the mass loss at 500°C to the mass loss at 600°C is 25% or more when thermogravimetric analysis is performed at a heating rate of 10°C / min.

[0027] The present disclosure (22) is a composition of any combination with any of the present disclosures (17) to (21) in which the fluorine-containing compound is a fluorine-containing polymer.

[0028] The present disclosure (23) is a composition in any combination with any of the present disclosures (17) to (22), in which the fluorine-containing compound is at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, polydifluoroethylene, ethylene / tetrafluoroethylene copolymer, and fluororubber.

[0029] The present disclosure (24) is a composition of any combination with any of the present disclosures (17) to (23), wherein the basic metal compound is at least one selected from the group consisting of calcium carbonate, calcium oxide, calcium hydroxide, magnesium oxide, and magnesium hydroxide.

[0030] The present disclosure (25) is a composition for use as a foaming inhibitor, which is any combination with any of the present disclosures (17) to (24).

[0031] According to the present disclosure, it is possible to provide a method for producing a metal fluoride and a composition that can produce a metal fluoride while suppressing the generation of corrosive gases.

[0032] The present disclosure will be specifically described below.

[0033] The present disclosure relates to a method for producing a metal fluoride, comprising: a step (1) of mechanochemically treating a fluorine-containing compound and a basic metal compound containing at least one selected from the group consisting of alkali metals and alkaline earth metals to obtain a composition containing the fluorine-containing compound and the basic metal compound; and a step (2) of heat-treating the composition to obtain a metal fluoride containing at least one selected from the group consisting of alkali metals and alkaline earth metals.

[0034] In the production method of the present disclosure, mechanochemical treatment is performed before heat treatment, thereby suppressing the generation of corrosive gases such as hydrogen fluoride. It is presumed that the mechanochemical treatment causes the fluorine-containing compound and the basic metal compound to form aggregates of fine particles, thereby increasing the contact area between the fluorine-containing compound and the basic metal compound and suppressing the generation of corrosive gases. According to the production method of the present disclosure, metal fluorides can be produced without using equipment with high corrosion resistance. Furthermore, since high-pressure treatment is not required and production can be performed using general-purpose equipment, industrialization is easy.

[0035] The fluorine-containing compound used in the production method of the present disclosure may be any compound having a fluorine atom, excluding metal fluorides. The fluorine-containing compound may be a compound having a fluorine atom bonded to a carbon atom, and is preferably an organic compound having a fluorine atom bonded to a carbon atom. In addition, the fluorine-containing compound is preferably solid at 25°C, in order to facilitate mechanochemical treatment.

[0036] The fluorine-containing compound is preferably a fluorine-containing polymer compound, more preferably a fluorine-containing polymer. The molecular weight of the fluorine-containing polymer compound is usually more than 2000, and can be measured by a known method depending on the type of compound.

[0037] The fluoropolymer preferably contains polymerization units based on at least one monomer selected from the group consisting of tetrafluoroethylene [TFE], difluoroethylene, chlorotrifluoroethylene [CTFE], hexafluoropropylene [HFP], trifluoroethylene, and monofluoroethylene, more preferably contains polymerization units based on at least one monomer selected from the group consisting of TFE, difluoroethylene, and CTFE, further preferably contains polymerization units based on at least one monomer selected from the group consisting of TFE and VdF, and still more preferably contains polymerization units based on TFE. Examples of the difluoroethylene include vinylidene fluoride [VdF] and 1,2-difluoroethylene.

[0038] The fluorine-containing polymer may be a fluororesin or a fluororubber, but is preferably a fluororesin.

[0039] Examples of the fluororesin include polytetrafluoroethylene [PTFE], tetrafluoroethylene [TFE] / perfluoro(alkyl vinyl ether) [PAVE] copolymer [PFA], TFE / hexafluoropropylene [HFP] copolymer [FEP], ethylene [Et] / TFE copolymer [ETFE], Et / TFE / HFP copolymer [EFEP], polychlorotrifluoroethylene [PCTFE], chlorotrifluoroethylene [CTFE] / TFE copolymer, CTFE / TFE / PAVE copolymer, Et / CTFE copolymer, polyfluoro Examples of the perfluoroalkyl allyl ether include vinyl fluoride [PVF], polydifluoroethylene (polyvinylidene fluoride [PVdF], poly(1,2-difluoroethylene), etc.), vinylidene fluoride [VdF] / TFE copolymer, VdF / HFP copolymer, VdF / TFE / HFP copolymer, VdF / HFP / (meth)acrylic acid copolymer, VdF / CTFE copolymer, VdF / pentafluoropropylene copolymer, VdF / PAVE / TFE copolymer, TFE / perfluoroalkyl allyl ether copolymer, and the like, and these can be used alone or in combination. The perfluoroalkyl allyl ether is CF ２ =CFCF ２ -O-Rf １ (Rf １ is a perfluoroalkyl group having 1 to 5 carbon atoms).

[0040] The fluororesin may be a fluororesin having a monomer unit having a C—H bond, or may be a perhalopolymer, preferably a perfluoropolymer, in which halogen atoms are bonded to all of the carbon atoms constituting the main chain of the polymer.

[0041] Examples of the fluororubber include vinylidene fluoride [VdF]-based fluororubbers, tetrafluoroethylene [TFE] / propylene [Pr]-based fluororubbers, TFE / Pr / VdF-based fluororubbers, ethylene [Et] / hexafluoropropylene [HFP]-based fluororubbers, Et / HFP / VdF-based fluororubbers, Et / HFP / TFE-based fluororubbers, fluorosilicone-based fluororubbers, and fluorophosphazene-based fluororubbers, and these may be used alone or in combination.

[0042] Examples of the VdF-based fluororubbers include VdF / HFP copolymer, VdF / TFE / HFP copolymer, VdF / chlorotrifluoroethylene [CTFE] copolymer, VdF / CTFE / TFE copolymer, VdF / perfluoro(alkyl vinyl ether) [PAVE] copolymer, VdF / TFE / PAVE copolymer, VdF / HFP / PAVE copolymer, VdF / HFP / TFE / PAVE copolymer, VdF / TFE / Pr copolymer, VdF / Et / HFP copolymer, and VdF / copolymer of a fluorine-containing monomer represented by the following formula (1): Formula (1): CH ２ = CFRf ２ (1) (wherein, Rf ２ represents a linear or branched fluoroalkyl group having 1 to 12 carbon atoms)

[0043] As the fluorine-containing polymer, at least one selected from the group consisting of PTFE, PFA, FEP, polydifluoroethylene, ETFE and fluorine rubber is preferred, at least one selected from the group consisting of PTFE, PFA, FEP, PVdF, ETFE and fluorine rubber is more preferred, at least one selected from the group consisting of PTFE, PFA, FEP, PVdF, ETFE and VdF-based fluorine rubber is even more preferred.As the fluorine-containing polymer, fluororesin is preferred, at least one selected from the group consisting of PTFE, PFA, FEP, PVdF and ETFE is more preferred, at least one selected from the group consisting of PTFE, PVdF and ETFE is even more preferred, at least one selected from the group consisting of PTFE and PVdF is even more preferred, and PTFE is even more preferred. As the fluorine-containing polymer, from the viewpoint of reactivity, a fluororesin having a monomer unit having a C—H bond is also preferred, at least one selected from the group consisting of PVdF and ETFE is more preferred, and PVdF is still more preferred.

[0044] The fluorine-containing compound does not have to be a polymer, and may be a fluorine-containing low-molecular-weight compound, so long as it is solid at 25° C. The fluorine-containing low-molecular-weight compound may have a molecular weight of 2000 or less. The molecular weight of the fluorine-containing low-molecular-weight compound can be determined by calculation from the chemical formula.

[0045] The fluorine-containing low molecular weight compound is preferably a fluorine-containing telomer. Examples of the fluorine-containing telomer include those represented by the following formula: ２ F ５ (CF ２ CF ２ ) ｎ -X (wherein X is a halogen atom and n is an integer of 5 or greater). In the above formula, X may be a halogen atom other than a fluorine atom, and is preferably a chlorine atom, a bromine atom, or an iodine atom, more preferably a bromine atom or an iodine atom, and even more preferably an iodine atom. In the above formula, n is preferably an integer of 5 or greater and an integer of 10 or less.

[0046] The fluorine-containing low molecular weight compound is represented by the following general formula (I): Y—(CF ２ ) ｘ１ - (CH ２ ) ｙ１ -A (I) (wherein Y represents H or F, x1 represents an integer of 4 or more, y1 represents an integer of 0 to 3, and A represents -SO ３ M Ｉ or -COOM Ｉ indicates M Ｉ is H, NH ４ , Li, Na, Mg, Al, K or Ca), and a compound (I) represented by the following general formula (II): F—(CF ２ ) ｘ２ O(CFXCF ２ O) ｙ２ -CFX-A (II) (wherein x2 represents an integer of 1 or more, y2 represents an integer of 0 to 10, and X represents F or CF ３ A represents -SO ３ M ＩＩ or -COOM ＩＩ indicates M ＩＩ is H, NH ４ , Li, Na, Mg, Al, K or Ca.

[0047] Examples of the compound (I) include fluorocarboxylic acids and salts thereof, such as perfluorocarboxylic acids and salts thereof. Examples of salts include ammonium salts and sodium salts. Examples of the compound (I) also include fluorosulfonic acids and salts thereof, such as perfluorosulfonic acids and salts thereof. Examples of salts include ammonium salts and sodium salts. Examples of the compound (II) include perfluoroethercarboxylic acids and salts thereof, such as 2,3,3,3-tetrafluoro-2-[1,1,2,3,3,3-hexafluoro-2-(trifluoromethoxy)propoxy]-propanoic acid.

[0048] The fluorine-containing low molecular weight compound may be adsorbed onto an adsorbent. In this embodiment, the solid obtained by adsorbing the fluorine-containing low molecular weight compound onto the adsorbent may be subjected to mechanochemical treatment. The adsorbent is not limited as long as it is a solid capable of adsorbing the fluorine-containing low molecular weight compound, but is preferably at least one selected from the group consisting of activated carbon, silica gel, clay, metal-organic framework (MOF), and zeolite.

[0049] In the manufacturing method of the present disclosure, a composition containing the fluorine-containing compound and other components may be subjected to mechanochemical treatment. The other components may be used within a range that does not impair the effects of the manufacturing method of the present disclosure. Examples of the other components include general fillers, polymers, and the adsorbents described above.

[0050] Examples of the common filler include inorganic fillers such as glass fiber, glass beads, carbon fiber, spherical carbon, carbon black, graphite, silica, alumina, mica, silicon carbide, boron nitride, aluminum nitride, titanium oxide, bismuth oxide, cobalt oxide, magnesium oxide, molybdenum disulfide, bronze, gold, silver, copper, nickel, aluminum fluoride, carbon fluoride, and carbon black.

[0051] Examples of the common polymers include polyolefin resins such as polyethylene and polypropylene; polyamide [PA] resins such as nylon 6, nylon 11, nylon 12, nylon 46, nylon 66, nylon 610, nylon 612, and nylon MXD6; polyesters such as polyethylene terephthalate [PET], polybutylene terephthalate [PBT], polyarylate, aromatic polyesters (including liquid crystal polyesters), and polycarbonate [PC]; polyacetal [POM] resins; polyether resins such as polyphenylene oxide [PPO], modified polyphenylene ether, and polyether ether ketone [PEEK]; polyamide imide [PAI] resins such as polyamino bismaleimide; polysulfone resins such as polysulfone [PSF] and polyethersulfone [PES]; vinyl polymers such as ABS resin and poly 4-methylpentene-1 (TPX resin), as well as polyphenylene sulfide [PPS], polyketone sulfide, polyetherimide, polyimide [PI], and epoxy resins. The nylon MXD6 is a crystalline polycondensate obtained from metaxylenediamine (MXD) and adipic acid. The general polymer may be a polymer that does not contain fluorine.

[0052] The content of the above other components may be 50% by mass or less, preferably 30% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less, relative to the composition, and may be 0% by mass or more, 0.01% by mass or more, 0.1% by mass or more, or 1% by mass or more.

[0053] The fluorine-containing compound (or the composition when the other components are present; the same applies hereinafter) may be in the form of a powder, a molded product, or waste material from the manufacturing process or after use of a product. It may also be one that has been heated once to or above its melting point. If necessary, the fluorine-containing compound may be pulverized before use.

[0054] The shape of the fluorine-containing compound is not particularly limited and may be powder, sheet, block, pellet, flake, or the like, but from the viewpoint of reaction efficiency, it is preferably in the form of a sheet, block, pellet, or flake, more preferably in the form of a sheet, block, or pellet, even more preferably in the form of a sheet or block, and even more preferably in the form of a block. Powder or flake is also preferred.

[0055] The size of the fluorine-containing compound is not particularly limited, but it has been found that a larger size to some extent improves the reaction efficiency. Generally, the smaller the size, the higher the reaction efficiency tends to be, so this finding is unexpected. Of the three dimensions indicating the size of the fluorine-containing compound, the length of at least one dimension may be 0.001 mm or more, preferably 0.010 mm or more, more preferably 0.100 mm or more, more preferably 1.0 mm or more, even more preferably 2.0 mm or more, particularly preferably 3.0 mm or more, and preferably 20 mm or less, more preferably 10 mm or less, even more preferably 5.0 mm or less, and even more preferably 4.0 mm or less. Of the three dimensions indicating the size of the fluorine-containing compound, it is preferable that the length of the shortest dimension is within the above range. Furthermore, it is more preferable that the lengths of at least two of the three dimensions indicating the size of the fluorine-containing compound are within the above range, and it is even more preferable that the length of the third dimension is within the above range. The length of the dimension indicating the size of the fluorine-containing compound is measured using a micrometer or vernier calipers.

[0056] When the fluorine-containing compound is in powder form, the average particle size can also be used as an index of size. When the fluorine-containing compound is in powder form, the average particle size may be 10 μm or more, preferably 30 μm or more, more preferably 100 μm or more, and even more preferably 200 μm or more, and is preferably 4000 μm or less, more preferably 2000 μm or less, and even more preferably 1000 μm or less. The average particle size of the fluorine-containing compound is measured in a dry state using a laser diffraction / scattering particle size distribution analyzer manufactured by Nikkiso Co., Ltd., under a vacuum pressure of 20 mH. ２ Measurement is carried out at 0°C and is considered to be equal to the particle diameter corresponding to 50% of the integrated particle size distribution (volume basis).

[0057] The basic metal compound used in the production method of the present disclosure contains at least one selected from the group consisting of alkali metals and alkaline earth metals. Examples of the alkali metal include lithium, sodium, potassium, etc., and one or more of these can be used. Examples of the alkaline earth metal include magnesium, calcium, strontium, barium, etc., and one or more of these can be used. From the viewpoint of reactivity and corrosive gas suppression, the basic metal compound preferably contains an alkaline earth metal, more preferably contains at least one selected from the group consisting of magnesium, calcium, and strontium, even more preferably contains at least one selected from the group consisting of magnesium and calcium, and even more preferably contains calcium.

[0058] From the viewpoint of reactivity and suppression of corrosive gases, the basic metal compound is preferably at least one selected from the group consisting of basic metal oxides, basic metal hydroxides, and basic metal carbonates.

[0059] Examples of the basic metal oxide include alkali metal oxides and alkaline earth metal oxides. Examples of the alkali metal oxide include lithium oxide, sodium oxide, potassium oxide, etc., and one or more of these can be used. Examples of the alkaline earth metal oxide include magnesium oxide, calcium oxide, strontium oxide, barium oxide, etc., and one or more of these can be used. From the viewpoint of reactivity and corrosive gas suppression, the basic metal oxide is preferably an alkaline earth metal oxide, more preferably at least one selected from the group consisting of magnesium oxide, calcium oxide, and strontium oxide, even more preferably at least one selected from the group consisting of magnesium oxide and calcium oxide, and even more preferably calcium oxide (CaO).

[0060] Examples of the basic metal hydroxide include alkali metal hydroxides and alkaline earth metal hydroxides. Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, etc., and one or more of these can be used. Examples of the alkaline earth metal hydroxide include magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, etc., and one or more of these can be used. From the viewpoint of reactivity and corrosive gas suppression, the basic metal hydroxide is preferably an alkaline earth metal hydroxide, more preferably at least one selected from the group consisting of magnesium hydroxide, calcium hydroxide, and strontium hydroxide, and even more preferably at least one selected from the group consisting of magnesium hydroxide and calcium hydroxide, and calcium hydroxide (Ca(OH) ２ ) is even more preferred.

[0061] Examples of the basic metal carbonate include alkali metal carbonate and alkaline earth metal carbonate. Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, potassium carbonate, etc., and one or more of these can be used. Examples of the alkaline earth metal carbonate include magnesium carbonate, calcium carbonate, strontium carbonate, barium carbonate, etc., and one or more of these can be used. From the viewpoint of reactivity and corrosive gas suppression, the basic metal carbonate is preferably an alkaline earth metal carbonate, more preferably at least one selected from the group consisting of magnesium carbonate, calcium carbonate, and strontium carbonate, and even more preferably at least one selected from the group consisting of magnesium carbonate and calcium carbonate, and calcium carbonate (CaCO ３ ) is even more preferred.

[0062] From the viewpoints of reactivity and corrosive gas suppression, the basic metal compound is preferably at least one selected from the group consisting of basic metal carbonates and basic metal hydroxides, more preferably basic metal carbonates, and even more preferably calcium carbonate. From the same viewpoint, the basic metal compound is also preferably at least one selected from the group consisting of calcium carbonate, calcium oxide, calcium hydroxide, magnesium oxide, and magnesium hydroxide, more preferably at least one selected from the group consisting of calcium carbonate, calcium oxide, and magnesium hydroxide. Similarly, at least one selected from the group consisting of calcium carbonate, calcium hydroxide, and magnesium hydroxide is also preferred.

[0063] The mixing ratio of the basic metal compound in the mechanochemical treatment is preferably 0.1 equivalents or more, more preferably 0.5 equivalents or more, even more preferably 1 equivalent or more, even more preferably 1.5 equivalents or more, particularly preferably 2 equivalents or more, and is preferably 10 equivalents or less, more preferably 8 equivalents or less, even more preferably 5 equivalents or less, even more preferably 4 equivalents or less, particularly preferably 3 equivalents or less, relative to 1 equivalent (molar equivalent) of the fluorine-containing compound. When the fluorine-containing compound is a fluorine-containing polymer, the equivalent is calculated based on the monomers constituting the fluorine-containing polymer.

[0064] The mechanochemical treatment is a treatment method in which mechanical energy is applied to a reactant (preferably a solid reactant) by methods such as shearing, compression, stretching, grinding, friction, kneading, mixing, dispersing, crushing, shaking, etc., to activate the reactant and impart structural change, phase transition, reactivity, adsorptivity, catalytic activity, etc. The method of mechanochemical treatment is not particularly limited, and examples include a compression shear treatment method, an impact treatment method, and a mixed shear friction method, with the impact treatment method being preferred.

[0065] The mechanochemical treatment is usually carried out using a grinding medium. The grinding medium is preferably not connected to the reaction vessel. The grinding medium may be used in combination with a member connected to the reaction vessel, such as a stirring member.

[0066] The shape of the grinding medium is not particularly limited, and may be spherical, ellipsoidal, cylindrical, cylindrical, bale-shaped, tea canister-shaped, etc., but from the viewpoint of reaction efficiency, it is preferably spherical, ellipsoidal, or cylindrical, more preferably spherical or ellipsoidal, and even more preferably spherical.

[0067] From the viewpoint of reaction efficiency, the grinding medium may have a length of at least one of the three dimensions indicating the size of the grinding medium of 1 mm or more, preferably 5 mm or more, and preferably 100 mm or less, more preferably 70 mm or less, even more preferably 50 mm or less, and even more preferably 40 mm or less. Of the three dimensions indicating the size of the grinding medium, it is preferable that the length of the shortest dimension is within the above range. Furthermore, it is more preferable that the lengths of at least two of the three dimensions indicating the size of the grinding medium are within the above range, and even more preferable that the length of the third dimension is within the above range. When the grinding medium is spherical, it is preferable that the diameter is within the above range. By using grinding media of such sizes, the energy in the mechanochemical treatment can be further increased, and the reaction efficiency can be further improved.

[0068] The material of the grinding medium is not particularly limited, and examples thereof include steels such as carbon steel, stainless steel, and chromium steel, zirconia, tungsten carbide, agate, silicon nitride, alumina, and polyamide, and one or more of these may be used. Among these, steels and zirconia are preferred, steels are more preferred, and carbon steel and stainless steel are even more preferred.

[0069] The material of the reaction vessel used in the mechanochemical treatment is not particularly limited, and examples thereof include steels such as carbon steel, stainless steel, and chromium steel, zirconia, tungsten carbide, agate, silicon nitride, alumina, and polyamide, and one or more of these can be used. Among these, steels and zirconia are preferred, steels are more preferred, and carbon steel and stainless steel are even more preferred. The material of the reaction vessel may be the same as or different from the grinding medium.

[0070] From the viewpoint of reaction efficiency, the filling rate of the grinding medium relative to the internal volume of the reaction vessel is preferably 50% by volume or more, more preferably 60% by volume or more, and is preferably 90% by volume or less, more preferably 85% by volume or less, and even more preferably 83% by volume or less.

[0071] From the viewpoint of reaction efficiency, the ratio of the material to the internal volume of the reaction vessel is preferably 0.3% by volume or more, more preferably 0.5% by volume or more, and even more preferably 1% by volume or more, and is preferably 20% by volume or less, more preferably 10% by volume or less, and even more preferably 6% by volume or less. The ratio of the material to be treated is the total ratio of all raw materials to be mechanochemically treated, such as the fluorine-containing compound and the basic metal compound.

[0072] The mechanochemical treatment is preferably carried out by applying an energy of 0.1 J / s / g or more. The energy is more preferably 0.3 J / s / g or more, even more preferably 0.5 J / s / g or more, even more preferably 1.0 J / s / g or more, even more preferably 2.0 J / s / g or more, and particularly preferably 2.5 J / s / g or more, and is preferably 30 J / s / g or less, more preferably 15 J / s / g or less, even more preferably 10 J / s / g or less, and even more preferably 5.0 J / s / g or less. Applying energy within the above range can further increase the reaction efficiency and further suppress the generation of corrosive gases during heat treatment. The energy to be applied is not particularly limited as long as it is mechanical energy, but collision energy is particularly preferred.

[0073] The energy is energy per unit mass, and in the case of collision energy, for example, it is calculated using simulation software according to the following formula, based on the method described in AIChE Journal, Vol. 52, No. 10, 2006, pp. 3421-3426. The simulation software is not limited as long as it can perform calculations based on the above method, and for example, KIK DEM manufactured by Tohoku University or UX-DEM manufactured by JX Metals can be used. (In the formula, E ｗ is the total collision energy (J / s / g), m is the mass of the grinding media (g), v ｊ is the relative velocity (m / s), W is the total mass (g) of the object to be treated introduced into the container, t ｓrepresents the simulation time (s). The relative velocity is the relative velocity between the grinding media or between the grinding media and the inner wall of the reaction vessel when they collide, and can be adjusted, for example, by the mass of the powder media, the vibration frequency or rotation speed of the device.

[0074] The mechanochemical treatment is preferably carried out by applying an integrated energy of 3000 J / g or more. The integrated energy is more preferably 3800 J / g or more, even more preferably 5000 J / g or more, even more preferably 10000 J / g or more, and preferably 400000 J / g or less, more preferably 150000 J / g or less, even more preferably 100000 J / g or less, and even more preferably 90000 J / g or less. By applying an integrated energy within the above range, the reaction efficiency can be further improved and the generation of corrosive gases during heat treatment can be further suppressed. The energy to be applied is not particularly limited as long as it is mechanical energy, but collision energy is particularly preferred.

[0075] The integrated energy is the integrated energy per unit mass, and is a value obtained by multiplying the above-mentioned energy by the processing time of the mechanochemical treatment.

[0076] The apparatus for carrying out the mechanochemical treatment is not particularly limited as long as it is an apparatus capable of applying mechanical energy by the above-mentioned method, and known pulverizers and mixers can be used. For example, pulverizers such as ball mills, rod mills, jet mills, rotary mills, vibration mills, SAG mills, and planetary mills; grinders such as rotary stone mills and crushers; (horizontal axis rotation) container rotation type mixers such as horizontal cylindrical, V-type, double cone, square cube, S-type, and continuous V-type; (baffle blade equipped) container rotation type mixers such as horizontal cylindrical, V-type, double cone, and ball mill types; (rotational vibration) container rotation type mixers such as rocking type and cross rotary type; ribbon type, paddle type, single shaft rotor type, and bug mill type. (horizontal axis rotation) fixed vessel type mixers; (vertical axis rotation) fixed vessel type mixers such as ribbon type, screw type, planetary type, turbine type, high speed fluid type, rotating disk type and Mahler type; (vibration) fixed vessel type mixers such as vibration mill type and sieve type; (fluidization) fluid motion type mixers such as heterogeneous fluidized bed, swirling fluidized bed, type with riser and Jot pump type; (gravity) fluid motion type mixers such as gravity type and static mixer; and kneaders such as twin-screw kneaders, single-screw kneaders, mixers, roll mills, etc.

[0077] As an apparatus for carrying out the mechanochemical treatment, a rotary mill, a vibration mill, or a planetary mill is preferred, with a vibration mill or a planetary mill being more preferred. In addition, from the viewpoint of ease of industrialization, a rotary mill or a vibration mill is preferred, with a vibration mill being more preferred.

[0078] The mechanochemical treatment can be carried out using a planetary mill, but is also preferably carried out without a planetary mill. While a planetary mill is a device that can impart high energy, it is also a device that generates a large amount of wear powder derived from the device (see, for example, J.Soc.Powder Technol., Japan, 44, 186-190 (2007) [https: / / www.jstage.jst.go.jp / article / sptj1978 / 44 / 3 / 44_3_186 / _pdf / -char / ja]). The inclusion of wear powder may interfere with the use of the product after reaction. The manufacturing method of the present disclosure can react a fluorine-containing compound under conditions that are less likely to generate wear powder derived from the device. In addition, methods that use general-purpose equipment such as a ball mill or vibration mill rather than a planetary mill also have the advantage of being easily industrialized.

[0079] The temperature of the mechanochemical treatment is preferably 5°C or higher, more preferably 10°C or higher, even more preferably 15°C or higher, even more preferably 20°C or higher, and is preferably less than 300°C, more preferably 250°C or lower, even more preferably 200°C or lower, and even more preferably 160°C or lower.

[0080] In particular, when the fluorine-containing compound is a fluorine-containing polymer compound that does not contain hydrogen, the reaction is accelerated by heating, so it is preferable to carry out the reaction at room temperature (25° C.) or above.

[0081] The time for the mechanochemical treatment can be determined depending on the equipment used, the amount of material to be treated, etc., but may be, for example, 0.1 hours or more, 0.5 hours or more, 1 hour or more, or 100 hours or less, 50 hours or less, 30 hours or less, 20 hours or less, or 10 hours or less.

[0082] The mechanochemical treatment may be carried out in any atmosphere, for example, in air, in an inert gas, in vacuum, etc. From the viewpoint of low cost, it is preferably carried out in air.

[0083] The mechanochemical treatment is preferably carried out in a dry manner, which means that the amount of liquid in the reaction system is 5% by mass or less, preferably 1% by mass or less, more preferably 0.1% by mass or less, and even more preferably 0.01% by mass or less.

[0084] The mechanochemical treatment provides a composition containing the fluorine-containing compound and the basic metal compound. When the basic metal compound is at least one selected from the group consisting of the basic metal carbonates and the basic metal hydroxides, the composition obtained in step (1) can be used as the composition of the present disclosure described below.

[0085] The content of the fluorine-containing compound in the composition obtained in step (1) is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, even more preferably 30% by mass or less, and particularly preferably 25% by mass or less, relative to the composition. The content of the fluorine-containing compound is measured by a gravimetric method after washing the composition with hydrochloric acid to remove components other than the fluorine-containing compound.

[0086] The content of the basic metal compound in the composition is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, even more preferably 70% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. The content of the basic metal compound is determined by measuring the composition by XRD, and if no metal fluoride is present, washing the composition with hydrochloric acid and determining the mass loss. If a metal fluoride is present, the ratio of the basic metal compound to the metal fluoride is determined from the chart obtained by XRD using the RIR method (reference intensity ratio method), and then washing the product with hydrochloric acid, and determining the mass loss and the ratio of the basic metal compound to the metal fluoride before washing. The RIR method can be performed by performing analysis on an XRD measurement device and an analysis device attached to the XRD measurement device.

[0087] The composition may or may not contain a metal fluoride containing at least one selected from the group consisting of alkali metals and alkaline earth metals. The content of the metal fluoride in the composition may be 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, or 5% by mass or less, based on the composition. The content of the metal fluoride may be 0% by mass, 0.5% by mass or more, or 1% by mass or more. The content of the metal fluoride can be measured by an RIR method using X-ray diffraction (XRD) or the like.

[0088] In step (2), the composition obtained in step (1) is heat-treated to obtain a metal fluoride containing at least one metal selected from the group consisting of alkali metals and alkaline earth metals.

[0089] From the viewpoint of reactivity, the temperature of the heat treatment is preferably 300°C or higher, more preferably 350°C or higher, even more preferably 400°C or higher, and even more preferably 450°C or higher; from the viewpoint of production costs, etc., the temperature is preferably 800°C or lower, more preferably 700°C or lower, even more preferably 600°C or lower, and even more preferably 550°C or lower.

[0090] The heat treatment may be performed under pressure. In this case, the pressure is not particularly limited, but is preferably 30 MPa or less, more preferably 20 MPa or less, and even more preferably 10 MPa or less. The lower limit is not particularly limited, and may be the minimum pressure that can be set by the apparatus. In the manufacturing method of the present disclosure, heat treatment can be performed under the above-mentioned relatively low pressure conditions, so that production costs can be reduced.

[0091] The time for the heat treatment can be determined depending on the equipment used, the amount of material to be treated, etc., and may be, for example, 10 minutes or more, 0.5 hours or more, 1 hour or more, 3 hours or more, or 100 hours or less, 50 hours or less, 30 hours or less, or 10 hours or less.

[0092] The heat treatment may be carried out in any atmosphere, for example, in air, in an inert gas, in vacuum, etc. From the viewpoint of low cost, it is preferably carried out in air.

[0093] The heat treatment can be carried out using known equipment, such as a hot air circulation device, a vacuum heat treatment device, a box-type electric furnace, a single-screw extruder, a twin-screw extruder, a kiln furnace, a microwave device, or an infrared heater.

[0094] The heat treatment produces a metal fluoride containing at least one selected from the group consisting of alkali metals and alkaline earth metals. Examples of the alkali metals and alkaline earth metals include those contained in the basic metal compound, and preferred forms are also similar. The metal fluoride may be at least one selected from the group consisting of alkali metal fluorides and alkaline earth metal fluorides, preferably an alkaline earth metal fluoride, more preferably at least one selected from the group consisting of magnesium fluoride and calcium fluoride, and more preferably calcium fluoride (CaF ２ ) is more preferred.

[0095] The production method of the present disclosure also preferably includes a step of purifying the crude product obtained in the above step (2) to recover the metal fluoride. The purification method is not particularly limited, and any known method can be used.

[0096] The production method of the present disclosure can be used not only for producing metal fluorides but also for decomposing (defluorinating) fluorine-containing compounds.

[0097] The present disclosure also relates to a composition comprising a fluorine-containing compound and a basic metal compound containing at least one selected from the group consisting of alkali metals and alkaline earth metals, wherein the amount of fluoride ions generated when heated at 600°C for 1 hour is 15 mass% or less relative to the fluorine-containing compound, and the basic metal compound is at least one selected from the group consisting of basic metal carbonates and basic metal hydroxides.

[0098] The composition of the present disclosure has the above-described configuration, and therefore can suppress the generation of corrosive gases such as hydrogen fluoride during heat treatment, and can produce a metal fluoride after heat treatment. Therefore, the composition can be used for various purposes, such as the production of metal fluorides, using general-purpose equipment without using equipment with high corrosion resistance.

[0099] Examples of the fluorine-containing compound in the composition of the present disclosure include the same fluorine-containing compounds as those that can be used in the production method of the present disclosure, and the preferred forms are also the same.

[0100] The content of the fluorine-containing compound in the composition of the present disclosure is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, even more preferably 30% by mass or less, and particularly preferably 25% by mass or less, relative to the composition. The content of the fluorine-containing compound is measured by a gravimetric method after washing the composition with hydrochloric acid to remove components other than the fluorine-containing compound.

[0101] In the composition of the present disclosure, the maximum length of the fluorine-containing compound is preferably less than 2 mm, more preferably 1.5 mm or less, even more preferably 1 mm or less, even more preferably 0.5 mm or less, and may be 0.0001 mm or more, or even 0.001 mm or more. A composition in which the maximum length of the fluorine-containing compound falls within the above range can be obtained by mechanochemical treatment. The maximum length is determined by cross-sectioning the secondary particles of the composition, identifying the region where the fluorine element (the fluorine-containing compound) is present using SEM / EDX, and measuring the maximum length of the region where the fluorine element is continuously present (the region occupied by the fluorine-containing compound) from the SEM image. Cross-sectioning can be performed, for example, by embedding the composition in a thermosetting resin or the like and cutting out the embedded composition using a microtome or the like.

[0102] Examples of the basic metal compound in the composition of the present disclosure include the same basic metal carbonates and basic metal hydroxides as the basic metal compounds that can be used in the production method of the present disclosure, and the preferred forms are also the same.

[0103] The content of the basic metal compound in the composition of the present disclosure is preferably 1% by mass or more, more preferably 50% by mass or more, 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 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. The content of the basic metal compound is determined by measuring the composition by XRD, and if no metal fluoride is present, washing the composition with hydrochloric acid and determining the mass loss. If a metal fluoride is present, the ratio of the basic metal compound to the metal fluoride is determined from the chart obtained by XRD using the RIR method (reference intensity ratio method), and then washing the product with hydrochloric acid, and determining the mass loss and the ratio of the basic metal compound to the metal fluoride before washing. The RIR method can be performed by performing analysis with an analyzer attached to an XRD measurement device.

[0104] The composition of the present disclosure may or may not contain a metal fluoride containing at least one selected from the group consisting of alkali metals and alkaline earth metals. The metal fluoride may be at least one selected from the group consisting of alkali metal fluorides and alkaline earth metal fluorides, preferably an alkaline earth metal fluoride, more preferably at least one selected from the group consisting of magnesium fluoride and calcium fluoride, and more preferably calcium fluoride (CaF ２ ) is more preferable. The content of the metal fluoride in the composition may be 50% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, or 10% by mass or less, relative to the composition. The content of the metal fluoride may be 0% by mass, 0.5% by mass or more, or 1% by mass or more. The content of the metal fluoride can be measured by an RIR method using X-ray diffraction (XRD) or the like.

[0105] The composition of the present disclosure generates fluoride ions in an amount of 15% by mass or less, preferably 13% by mass or less, more preferably 11% by mass or less, even more preferably 10% by mass or less, even more preferably 9% by mass or less, even more preferably 6% by mass or less, particularly preferably 3% by mass or less, and may also be 0% by mass or more, 0.01% by mass or more, or even 0.1% by mass or more. The amount of fluoride ions generated within the above range can adequately suppress the generation of corrosive gases during heat treatment. A composition having a fluoride ion generation amount within the above range can be obtained by mechanochemical treatment.

[0106] The amount of generated fluoride ions is measured by the following method. The sample is heated by placing a quartz tube containing the sample in a furnace heated under the following conditions, and the generated gas is collected and dissolved in 20 mL of alkaline collection liquid. The collection liquid containing the dissolved generated gas is analyzed by ion chromatography under the following conditions to quantify the amount of fluoride ions. (Heating conditions) Sample: Approximately 10 mg Heating temperature: 600°C Pressure: Atmospheric pressure Atmosphere: Air flow rate: 50 mL / min Collection time: 1 hour (Ion chromatography conditions) Apparatus: ICS-5000 manufactured by Thermo Fisher Scientific ＋ Separation column: 2 mmφ×250 mm IonPac AS30 Eluent: potassium hydroxide / gradient Sample injection volume: 10 μL Detector: electrical conductivity meter

[0107] In the composition of the present disclosure, the fluorine component is preferably uniformly dispersed. The dispersion state of the fluorine component can be confirmed, for example, by cutting a block of the composition and observing the cross section by mapping fluorine atoms using SEM / EDX.

[0108] When the composition of the present disclosure is subjected to thermogravimetric analysis at a heating rate of 10°C / min, the ratio of the mass loss at 500°C to the mass loss at 600°C is preferably 25% or more, more preferably 30% or more, even more preferably 50% or more, even more preferably 70% or more, even more preferably 90% or more, particularly preferably 95% or more, and may be less than 100%, may be 99.99% or less, or may be 99.9% or less. When the ratio of the mass loss at 500°C to the mass loss at 600°C is within the above range, the generation of corrosive gases during heat treatment can be further suppressed. A composition in which the ratio of the mass loss at 500°C to the mass loss at 600°C is within the above range can be obtained by mechanochemical treatment.

[0109] The ratio of the mass loss at 500°C to the mass loss at 600°C is calculated by precisely weighing out about 10 mg of a sample, placing it in a dedicated aluminum pan, and using a TG / DTA (thermogravimetric / differential thermal analyzer) to increase the temperature from 25°C to 600°C at a rate of 10°C / min in an air atmosphere, measuring the mass losses at 500°C and 600°C (mass loss from 25°C), and then calculating using the following formula: Ratio of mass loss at 500°C to mass loss at 600°C = mass loss at 500°C / mass loss at 600°C × 100

[0110] The composition of the present disclosure preferably has a 1% decomposition temperature of 450°C or less, more preferably 400°C or less, even more preferably 350°C or less, even more preferably 335°C or less, and may be 300°C or more. When the 1% decomposition temperature is within the above range, the generation of corrosive gases during heat treatment can be further suppressed. A composition having a 1% decomposition temperature within the above range can be obtained by mechanochemical treatment.

[0111] The 1% decomposition temperature is determined by precisely weighing out about 10 mg of a sample, placing it in a dedicated aluminum pan, and heating it in an air atmosphere using a TG / DTA (thermogravimetric / differential thermal analyzer) in a temperature range from 25°C to 600°C at a rate of 10°C / min, and determining the temperature at which the mass has decreased by 1% by mass from the mass at 25°C.

[0112] The composition of the present disclosure preferably contains secondary particles in which both fluorine and at least one metal selected from the group consisting of alkali metals and alkaline earth metals are detected when observed by SEM / EDX. This makes it possible to further suppress the generation of corrosive gases during heat treatment. The composition containing the above-mentioned specific secondary particles can be obtained by mechanochemical treatment. The above-mentioned specific secondary particles are considered to be a complex of a fluorine-containing compound and a basic metal compound, and cannot be obtained by simply mixing the fluorine-containing compound and the basic metal compound.

[0113] The composition of the present disclosure can be suitably produced, for example, by step (1) of the production method of the present disclosure described above.

[0114] The composition of the present disclosure generates a metal fluoride containing at least one selected from the group consisting of alkali metals and alkaline earth metals by heat treatment, and therefore can be suitably used for producing metal fluorides. The composition can also be suitably used as a foaming inhibitor in steel production, a raw material for hydrogen fluoride, and the like. In particular, the composition can be suitably used as a foaming inhibitor.

[0115] Although the embodiments have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the claims.

[0116] The present disclosure will now be described in more detail with reference to examples, but the present disclosure is not limited to these examples.

[0117] Each value was determined by the following method.

[0118] <Size of Fluorine-Containing Compound> (Flake Form) The thickness (μm) of 20 or more fluorine-containing compounds was measured using a micrometer, and the average value was taken as the thickness. The long side (mm) and short side (mm) of the fluorine-containing compound were measured using images taken using a Keyence VHX5000 video microscope, and the long side and short side of 90 or more flakes were taken as the average values. (Powder Form) Using a laser diffraction / scattering particle size distribution analyzer manufactured by Nikkiso Co., Ltd., the long side and short side were measured in a dry state at a vacuum pressure of 20 mH. ２ The measurement was carried out at 0°C and was set to be equal to the particle diameter corresponding to 50% of the integrated particle size distribution (volume basis).

[0119] <Collision Energy, Cumulative Collision Energy> Collision energy was calculated from the following formula using simulation software KIK DEM (Tohoku University) based on the method described in AIChE Journal, Vol. 52, No. 10, 2006, pp. 3421-3426. (In the formula, E ｗ is the total collision energy (J / s / g), m is the mass of the grinding media (g), v ｊ is the relative velocity (m / s), W is the total mass (g) of the object to be treated introduced into the container, t ｓrepresents the simulation time (s). The cumulative collision energy was calculated by multiplying the collision energy by the processing time of the mechanochemical treatment.

[0120] <Maximum length of fluorine-containing compound in composition obtained by mechanochemical treatment> After cross-sectioning of secondary particles of the composition, the region where fluorine element (fluorine-containing compound) is present is identified by SEM / EDX, and the maximum length of the region where fluorine element is continuously present (region occupied by fluorine-containing compound) is measured from the SEM image. The cross-sectioning was performed by embedding the composition in a thermosetting resin or the like and cutting out the embedded composition using a microtome or the like.

[0121] <Content of Fluorine-Containing Compound in Composition Obtained by Mechanochemical Treatment> The composition was washed with hydrochloric acid to remove components other than the fluorine-containing compound, and the content of the fluorine-containing compound was measured by a gravimetric method.

[0122] <Content of basic metal compound in composition obtained by mechanochemical treatment> The composition was measured by XRD, and if no metal fluoride was present, the composition was washed with hydrochloric acid and the content was determined from the mass loss. If a metal fluoride was present, the ratio of basic metal compound to metal fluoride was determined from the chart obtained by XRD by the RIR method (reference intensity ratio method), and the product was then washed with hydrochloric acid and the content was determined from the mass loss and the ratio of basic metal compound to metal fluoride before washing. The RIR method was performed by performing analysis on an XRD measurement device with an attached analyzer.

[0123] <Ratio of Mass Loss at 500°C to Mass Loss at 600°C> A composition obtained by mechanochemical treatment was used as a sample. Approximately 10 mg of the sample was precisely weighed and placed in a dedicated aluminum pan. Using a TG / DTA (differential thermal / thermogravimetric simultaneous analyzer), the sample was heated in an air atmosphere from 25°C to 600°C at a rate of 10°C / min. The mass losses at 500°C and 600°C (mass loss from 25°C) were measured and calculated using the following formula: Ratio of Mass Loss at 500°C to Mass Loss at 600°C = Mass Loss at 500°C / Mass Loss at 600°C × 100

[0124] <1% Decomposition Temperature> The composition obtained by the mechanochemical treatment was used as a sample. Approximately 10 mg of the sample was precisely weighed and placed in a dedicated aluminum pan. Using a TG / DTA (differential thermal / thermogravimetric simultaneous analyzer), the sample was heated in an air atmosphere from 25°C to 600°C at a rate of 10°C / min, and the temperature was set to the point where the mass had decreased by 1% by mass from the mass at 25°C.

[0125] <Amount of Fluoride Ions Generated> A composition obtained by mechanochemical treatment was used as a sample. The sample was heated by placing a quartz tube containing the sample in a furnace heated under the following conditions, and the generated gas was collected and dissolved in 20 mL of alkaline collection liquid. The collection liquid containing the dissolved generated gas was analyzed by ion chromatography under the following conditions to quantify the amount of fluoride ions. (Heating Conditions) Sample: Approximately 10 mg Heating Temperature: 600°C Pressure: Atmospheric Pressure Atmosphere: Air Flow Rate: 50 mL / min Collection Time: 1 hour (Ion Chromatography Conditions) Apparatus: ICS-5000 manufactured by Thermo Fisher Scientific ＋ Separation column: 2 mmφ×250 mm IonPac AS30 Eluent: potassium hydroxide / gradient Sample injection volume: 10 μL Detector: electrical conductivity meter

[0126] In each experimental example, the following materials (all solid at 25°C) were used. <Fluorine-containing compound> PTFE (1): Powder of PTFE M18 manufactured by Daikin Industries, Ltd. was compression-molded under conditions of 30 MPa for 1 minute, and baked at 370°C for 3 hours to obtain a molded product. The molded product obtained was cut and then pulverized to obtain flakes with an average thickness of 129 μm, an average long side of 2.4 mm, and an average short side of 0.9 mm. PTFE (2): PTFE (1) was further pulverized with an impact pulverizer to obtain powdered secondary particles with a D50 of 208 μm. PFA: AP-201 manufactured by Daikin Industries, Ltd. Fluororubber: A crosslinked sheet obtained by peroxide vulcanization of Dai-el G801 manufactured by Daikin Industries, Ltd. was freeze-pulverized. <Basic metal compound> CaCO ３(Basic metal carbonate): Calcium carbonate (special grade reagent) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. CaO (basic metal oxide): Prepared by heating calcium hydroxide (special grade reagent) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. at 900°C for 2 hours, and stored in a desiccator until cooled to room temperature before use. MgO (basic metal oxide): Magnesium oxide Mg(OH) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. ２ (Basic metal hydroxide): Magnesium hydroxide manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0127] Examples 1, 2, 5 to 7, 9, 10 to 13 The raw materials (fluorine-containing compound, basic metal compound) shown in Table 1 were weighed out. The raw materials and zirconia balls as grinding media were placed in the pot of a planetary mill. A lid was attached to the pot, and the pot was placed in the planetary mill body, and rotation was started. Mechanochemical treatment was carried out for a predetermined time to obtain a composition containing a fluorine-containing compound and a basic metal compound. The physical properties of the obtained composition were measured. The results are shown in Table 1. The planetary mill used for the mechanochemical treatment is as follows: Apparatus: Pulverisette planetary ball mill P-7 manufactured by Fritsch Grinding tube: zirconia pot (internal volume 45 mL, φ40 mm) Grinding media: zirconia balls (φ15 mm), 7 balls, filling rate 80% by volume

[0128] Approximately 10 mg of the composition obtained above was weighed out and placed in a dedicated aluminum pan. The composition was then heat-treated using a TG / DTA (differential thermal and thermogravimetric simultaneous analyzer, Hitachi High-Tech Science Corporation, TG / DTA7200) in an air atmosphere by increasing the temperature from 25°C to 600°C at a rate of 10°C / min. The residue obtained was measured by XRD (Rigaku Corporation, Smartlab). In Examples 1, 2, 5 to 7, and 9, CaF ２ A peak was detected at a position that could be identified as CaF ２ In Example 10, the production of MgF ２ A peak was detected at a position that could be identified as MgF ２ The generation of was confirmed.

[0129] Furthermore, for Examples 1, 2, and 5 to 7, the compositions obtained by the mechanochemical treatment were used to measure the amount of fluoride ions generated in accordance with the method for measuring the amount of fluoride ions generated described above. The results are shown in Table 1.

[0130] Examples 3, 4, and 8 The raw materials (fluorine-containing compound, basic metal compound) shown in Table 1 were weighed. Approximately half of the steel balls used as grinding media were placed in the pot of a vibration mill, followed by approximately half of the raw materials. The remaining steel balls were then placed in the pot, followed by the remaining raw materials. A lid was attached to the pot, and the pot was placed on the vibration mill body, and vibration was initiated. Mechanochemical treatment was carried out for a predetermined time to obtain a composition containing a fluorine-containing compound and a basic metal compound. The physical properties of the obtained composition were measured. The results are shown in Table 1. The vibration mill used for the mechanochemical treatment was as follows: Apparatus: MB1 type vibration mill manufactured by Chuo Kakoki Co., Ltd. Grinding tube: SUS pot (internal volume 3.6 L, φ145 x 225 mm) Grinding media: carbon steel balls (φ35 mm or φ20 mm), filling rate 80%, or SUS rods (φ25 mm, length 215 mm), filling rate 60% by volume Vibration frequency: 1200 rpm Total amplitude: 8 mm Water cooling: none

[0131] The composition obtained above was used to measure the amount of fluoride ions generated in accordance with the above-mentioned method for measuring the amount of fluoride ions generated. The results are shown in Table 1. After the mechanochemical treatment, the composition was heated from room temperature to 600°C at 10°C / min, and the residue after heating was measured using XRD. ２ A peak was detected at a position that could be identified as CaF ２ The generation of was confirmed.

[0132] Comparative Example 1 An experiment was carried out in the same manner as in Example 1, except that the raw materials (fluorine-containing compound, basic metal compound) shown in Table 1 were weighed, placed in a polyethylene bag without undergoing mechanochemical treatment, and then mixed by shaking for 3 minutes. The results are shown in Table 1.

[0133] Comparative Example 2 Physical properties were measured using only PTFE (1). The results are shown in Table 1.

[0134]

[0135] From the results of each example, it was found that the production method and composition of the present disclosure generate a small amount of fluoride ions during heat treatment, and therefore can suppress the generation of corrosive gas (HF).

Claims

1. A method for producing a metal fluoride, comprising: (1) a step of mechanochemically treating a fluorine-containing compound and a basic metal compound containing at least one selected from the group consisting of alkali metals and alkaline earth metals to obtain a composition containing the fluorine-containing compound and the basic metal compound; and (2) a step of heat-treating the composition to obtain a metal fluoride containing at least one selected from the group consisting of alkali metals and alkaline earth metals.

2. The method of claim 1, wherein the energy in the mechanochemical treatment is 0.1 J / s / g or more.

3. The manufacturing method according to claim 1 or 2, wherein the energy in the mechanochemical treatment is 0.5 to 10 J / s / g.

4. The method of any one of claims 1 to 3, wherein the cumulative energy in the mechanochemical treatment is 3000 J / g or more.

5. The method of any one of claims 1 to 4, wherein the cumulative energy in the mechanochemical treatment is 3,800 to 400,000 J / g.

6. The manufacturing method according to any one of claims 1 to 5, wherein the mechanochemical treatment is carried out using a planetary mill or a vibrating mill.

7. The method according to any one of claims 1 to 6, wherein the temperature of the heat treatment is 300°C or higher.

8. The method according to any one of claims 1 to 7, wherein the temperature of the heat treatment is 300 to 800°C.

9. The method of any one of claims 1 to 8, wherein the heat treatment time is from 10 minutes to 100 hours.

10. The method according to any one of claims 1 to 9, wherein the basic metal compound is at least one selected from the group consisting of basic metal oxides, basic metal hydroxides, and basic metal carbonates.

11. The method according to any one of claims 1 to 10, wherein the basic metal compound is a basic metal compound containing magnesium or calcium.

12. The method according to any one of claims 1 to 11, wherein the basic metal compound is at least one selected from the group consisting of calcium carbonate, calcium oxide, calcium hydroxide, magnesium oxide and magnesium hydroxide.

13. The method according to any one of claims 1 to 12, wherein the fluorine-containing compound is a fluorine-containing polymer.

14. The method according to any one of claims 1 to 13, wherein the fluorine-containing compound is at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, polydifluoroethylene, ethylene / tetrafluoroethylene copolymer, and fluororubber.

15. The method according to any one of claims 1 to 14, wherein the mixing ratio of the basic metal compound is 1 to 10 equivalents per equivalent of the fluorine-containing compound.

16. The method according to any one of claims 1 to 15, wherein the mixing ratio of the basic metal compound is 1 to 4 equivalents per equivalent of the fluorine-containing compound.

17. A composition comprising a fluorine-containing compound and a basic metal compound containing at least one selected from the group consisting of alkali metals and alkaline earth metals, wherein the amount of fluoride ions generated when heated at 600°C for 1 hour is 15 mass% or less relative to the fluorine-containing compound, and the basic metal compound is at least one selected from the group consisting of basic metal carbonates and basic metal hydroxides.

18. The composition according to claim 17, wherein the content of the fluorine-containing compound is 10% by mass or more.

19. The composition according to claim 17 or 18, wherein the content of the fluorine-containing compound is 10 to 40% by mass.

20. The composition according to any one of claims 17 to 19, wherein the content of the basic metal compound is 65 to 90 mass %.

21. The composition according to any one of claims 17 to 20, wherein when subjected to thermogravimetric analysis at a heating rate of 10°C / min, the ratio of the mass loss at 500°C to the mass loss at 600°C is 25% or more.

22. The composition according to any one of claims 17 to 21, wherein the fluorine-containing compound is a fluorine-containing polymer.

23. The composition according to any one of claims 17 to 22, wherein the fluorine-containing compound is at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene / perfluoro(alkyl vinyl ether) copolymer, tetrafluoroethylene / hexafluoropropylene copolymer, polydifluoroethylene, ethylene / tetrafluoroethylene copolymer, and fluororubber.

24. The composition according to any one of claims 17 to 23, wherein the basic metal compound is at least one selected from the group consisting of calcium carbonate, calcium oxide, calcium hydroxide, magnesium oxide and magnesium hydroxide.

25. The composition according to any one of claims 17 to 24, which is used as a foaming inhibitor.

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