Method for producing fluorine-containing compound

Abstract

Provided is a method for producing a fluorine-containing compound, said method having an excellent starting material conversion rate when producing a fluorine-containing compound such as a hydrochlorofluorocarbon and / or hydrofluorocarbon. A method for producing a fluorine-containing compound in which a fluorine-containing compound (A1) represented by formula (A1) is reacted with hydrogen in a gas phase in the presence of an activated metal catalyst to produce a fluorine-containing compound (A2) in which at least one of the chlorine atoms contained in the fluorine-containing compound (A1) is substituted by a hydrogen atom, the activated metal catalyst is obtained by heating a metal catalyst containing activated carbon and a metal supported on the activated carbon at 175-250 DEG C in the presence of oxygen gas and a diluent gas, and the ratio of the volume of the oxygen gas to the total volume of the oxygen gas and the diluent gas is 0.01-21 vol%.

Description

Technical Field

[0001] The present invention relates to a method for producing a fluorine-containing compound. Background Art

[0002] Hydrofluorocarbons are used as cleaning agents, refrigerants, foaming agents, and aerosols, as well as raw materials for the synthesis of these products. In addition, generally speaking, hydrofluorocarbons are obtained by hydrogen reduction of chlorofluorocarbons or hydrochlorofluorocarbons, and hydrochlorofluorocarbons are obtained by hydrogen reduction of chlorofluorocarbons. Patent Document 1 describes the use of 1-chloro-2,2,3,3-tetrafluoropropane as a synthetic raw material for producing 1-chloro-2,3,3-trifluoropropene, and Patent Document 2 describes the use of 1-chloro-1,1,2,2-tetrafluoropropane as a synthetic raw material for producing 2,2,3,3-tetrafluoropropene. Prior art literature Patent Literature

[0003] Patent Document 1: International Publication No. 2018 / 131394 Patent Document 2: Japanese Patent No. 5348240 Summary of the Invention Technical problem to be solved by the invention

[0004] In conventional methods for producing fluorine-containing compounds such as hydrochlorofluorocarbons and hydrofluorocarbons using a hydrogen reduction reaction, the conversion rate of the raw materials, such as chlorofluorocarbons and hydrochlorofluorocarbons, is sometimes low. Therefore, an object of the present invention is to provide a method for producing a fluorine-containing compound, wherein the method achieves an excellent raw material conversion rate when producing a fluorine-containing compound such as a hydrochlorofluorocarbon and / or a hydrofluorocarbon by subjecting raw materials such as a chlorofluorocarbon and a hydrochlorofluorocarbon to a hydrogen reduction reaction. Technical solutions used to solve technical problems

[0005] In order to solve the above technical problems, the inventors have conducted in-depth research and found that the above technical problems can be solved by the following technical solutions.

[0006] [1] A method for producing a fluorine-containing compound, This is a method for producing a fluorine-containing compound, wherein a fluorine-containing compound (A1) represented by the formula (A1) described below is reacted with hydrogen in the presence of an activated metal catalyst in a gas phase to produce a fluorine-containing compound (A2) in which at least one chlorine atom in the chlorine-containing compound (A1) is replaced with a hydrogen atom, wherein: The activated metal catalyst is obtained by heating a metal catalyst comprising activated carbon and a metal supported on the activated carbon at 175 to 250° C. in the presence of oxygen and a diluent gas. The ratio of the volume of the oxygen gas to the total volume of the oxygen gas and the diluent gas is 0.01 to 21 volume %. X a F2C-R f -CX a 3(A1) In the formula (A1) described below, X a Each independently represents a hydrogen atom, a fluorine atom or a chlorine atom; 4 X a Medium, 0 or 1 X a represents a fluorine atom, at least one X a represents a chlorine atom; R f represents a fluoroalkylene group. [2] The method for producing a fluorine-containing compound as described in [1], wherein the metal supported on the activated carbon is at least one selected from platinum, palladium, rhodium, ruthenium, nickel, rhenium, molybdenum and zirconium. 〔3〕 The method for producing a fluorine-containing compound as described in [1] or [2], wherein R f It is difluoromethylene. [4] The method for producing a fluorine-containing compound as described in any one of [1] to [3], wherein the fluorine-containing compound (A1) is selected from 1,1,1,3-tetrachloro-2,2,3,3-tetrafluoropropane, 1,1,3-trichloro-2,2,3,3-tetrafluoropropane, 1,1,1-trichloro-2,2,3,3-tetrafluoropropane, 1,3-dichloro-1,1,2,2-tetrafluoropropane, 1,1-dichloro-2,2,3,3-tetrafluoropropane, 1-chloro-1,1,2,2-tetrafluoropropane, 1-chloro-2,2,3,3-tetrafluoropropane At least one of fluoropropane, 1,3,3-trichloro-1,1,2,2,3-pentafluoropropane, 1,3-dichloro-1,1,2,2,3-pentafluoropropane, 1,1-dichloro-1,2,2,3,3-pentafluoropropane, 1-chloro-1,1,2,2,3-pentafluoropropane, 1-chloro-1,2,2,3,3-pentafluoropropane, 3,3,3-trichloro-1,1,1,2,2-pentafluoropropane, 3,3-dichloro-1,1,1,2,2-pentafluoropropane and 3-chloro-1,1,1,2,2-pentafluoropropane. 〔5〕 The method for producing a fluorine-containing compound as described in any one of [1] to [4], wherein The above reaction is further carried out in the presence of hydrogen chloride, The ratio of the volume of the hydrogen chloride to the total volume of the fluorine-containing compound (A1), the hydrogen, and the hydrogen chloride is 100 to 10,000 ppm by volume. [6] The method for producing a fluorine-containing compound according to any one of [1] to [5], wherein the ratio of the volume of the oxygen gas to the total volume of the oxygen gas and the diluent gas is 0.01 to 5% by volume. [7] The method for producing a fluorine-containing compound as described in any one of [1] to [6], wherein the metal specific surface area of ​​the activated metal catalyst calculated by a pulse adsorption method using carbon monoxide is within 4.0 m2 per 1 g of metal supported on the activated carbon. 6 / g or above. 〔8〕 A method for producing a fluorine-containing compound, comprising: Reaction step X, comprising reacting a fluorinated compound (B1) represented by formula (B1) described below with hydrogen in a gas phase in the presence of a first activated metal catalyst to obtain a composition comprising a fluorinated compound (B2) having at least one chlorine atom in which at least one chlorine atom in the fluorinated compound (B1) is replaced with a hydrogen atom, and hydrogen chloride; a purification step, wherein a purified product is obtained by removing at least a portion of the hydrogen chloride from the composition; and Reaction step Y, comprising reacting the fluorinated compound (B2) in the purified product with hydrogen in a gas phase in the presence of a second activated metal catalyst to obtain a fluorinated compound (B3) in which at least one of the chlorine atoms in the fluorinated compound (B2) is replaced with a hydrogen atom; The first activated metal catalyst and the second activated metal catalyst are obtained by heating a metal catalyst comprising activated carbon and a metal supported on the activated carbon at 175 to 250° C. in the presence of oxygen and a diluent gas. The ratio of the volume of the oxygen gas to the total volume of the oxygen gas and the diluent gas is 0.01 to 21 volume %. X b F2C-R f -CX b 3(B1) In the formula (B1) described below, X b Each independently represents a hydrogen atom, a fluorine atom or a chlorine atom; 4 X b Medium, 0 or 1 X b represents a fluorine atom, at least 2 X b represents a chlorine atom; R f represents a fluoroalkylene group. 〔9〕 A method for producing a fluorine-containing compound as described in [8], wherein the metal supported on the activated carbon of the first activated metal catalyst and the second activated metal catalyst is selected from at least one of platinum, palladium, rhodium, ruthenium, nickel, rhenium, molybdenum and zirconium. 〔10〕 The method for producing a fluorine-containing compound according to any one of <8> to <9>, wherein R f is difluoromethylene. 〔11〕 The method for producing a fluorine-containing compound according to any one of <8> to <10>, wherein the fluorine-containing compound (Bl) is at least one of 1,1,1,3-tetrachloro-2,2,3,3-tetrafluoropropane, 1,1,3-trichloro-2,2,3,3-tetrafluoropropane, 1,1,1-trichloro-2,2,3,3-tetrafluoropropane, 1,3-dichloro-1,1,2,2-tetrafluoropropane, 1,1-dichloro-2,2,3,3-tetrafluoropropane, 1,3,3-trichloro-1,1,2,2,3-pentafluoropropane, 1,3-dichloro-1,1,2,2,3-pentafluoropropane, 1,1-dichloro-1,2,2,3,3-pentafluoropropane, 3,3,3-trichloro-1,1,1,2,2-pentafluoropropane, and 3,3-dichloro-1,1,1,2,2-pentafluoropropane. 〔12〕 The method for producing a fluorine-containing compound according to any one of <8> to <11>, wherein the reaction step Y is further performed in the presence of hydrogen chloride, the ratio of the volume of the hydrogen chloride to the total volume of the purified product, the hydrogen, and the hydrogen chloride is 100 to 10,000 volume ppm. 〔13〕 The method for producing a fluorine-containing compound according to any one of <8> to <12>, wherein the ratio of the volume of the oxygen to the total volume of the oxygen and the dilution gas is 0.01 to 12 vol%. 〔14〕 The method for producing a fluorine-containing compound according to any one of <8> to <13>, wherein the specific surface area of the first activated metal catalyst and the second activated metal catalyst calculated by a pulse adsorption method with carbon monoxide is 4.0 m 6 / g or more per 1 g of metal supported on the activated carbon. Effects of the Invention

[0007] According to the present application, a method for producing a fluorine-containing compound can be provided, which is excellent in raw material conversion rate when producing a chlorofluorohydrocarbon and / or a hydrofluorocarbon. DETAILED DESCRIPTION

[0008] The meanings of the terms in the present specification are as shown below. A numerical range indicated with "~" means a range including the lower limit value and the upper limit value indicated before and after "~" as the lower limit value and the upper limit value.

[0009] In this specification, chlorofluorocarbons refer to compounds composed of chlorine atoms, fluorine atoms, and carbon atoms. Hydrochlorofluorocarbons refer to compounds composed of hydrogen atoms, chlorine atoms, fluorine atoms, and carbon atoms. Hydrofluorocarbons refer to compounds composed of hydrogen atoms, fluorine atoms, and carbon atoms.

[0010] In this specification, the following compounds may be represented by abbreviated names. 214cb: 1,1,1,3-tetrachloro-2,2,3,3-tetrafluoropropane 224ca: 1,1,3-trichloro-2,2,3,3-tetrafluoropropane 234cc: 1,3-dichloro-1,1,2,2-tetrafluoropropane 244cc: 1-chloro-1,1,2,2-tetrafluoropropane 224cc: 1,1,1-trichloro-2,2,3,3-tetrafluoropropane 234cb: 1,1-dichloro-2,2,3,3-tetrafluoropropane 244ca: 1-chloro-2,2,3,3-tetrafluoropropane 254cb: 1,1,2,2-tetrafluoropropane 215ca: 1,3,3-trichloro-1,1,2,2,3-pentafluoropropane 225cb: 1,3-dichloro-1,1,2,2,3-pentafluoropropane 235cc: 1-chloro-1,1,2,2,3-pentafluoropropane 225cc: 1,1-dichloro-1,2,2,3,3-pentafluoropropane 235ca: 1-chloro-1,2,2,3,3-pentafluoropropane 245ca: 1,1,2,2,3-pentafluoropropane 215cb: 3,3,3-trichloro-1,1,1,2,2-pentafluoropropane 225ca: 3,3-dichloro-1,1,1,2,2-pentafluoropropane 235cb: 3-chloro-1,1,1,2,2-pentafluoropropane 245cb: 1,1,1,2,2-pentafluoropropane

[0011] [Method for producing fluorine-containing compounds] As the method for producing the fluorine-containing compound of the present invention, there are exemplified the first embodiment and the second embodiment.

[0012] <First embodiment> The manufacturing method of the fluorine-containing compound of the first embodiment is a manufacturing method of a fluorine-containing compound in which at least one of chlorine atoms possessed by the fluorine-containing compound (A1) represented by formula (A1) is replaced with a hydrogen atom, by reacting the fluorine-containing compound (A1) with hydrogen in the presence of an activated metal catalyst in a gas phase (hereinafter also referred to as "reaction A"), wherein The activated metal catalyst is obtained by heating a metal catalyst containing activated carbon and a metal supported on the activated carbon in the presence of oxygen and a dilution gas at 175 to 250°C, The ratio of the volume of oxygen with respect to the total volume of oxygen and the dilution gas is 0.01 to 21 vol. %.

[0013] X a F2C-R f -CX a 3 (A1) In formula (A1), X a each independently represents a hydrogen atom, a fluorine atom, or a chlorine atom. Four X a Among them, 0 or 1 X a represents a fluorine atom, at least 1 X a represents a chlorine atom. R f represents a fluoroalkylene group.

[0014] Hereinafter, heating of the metal catalyst in the presence of a prescribed amount of oxygen and a dilution gas at 175 to 250°C is also referred to as "activation treatment".

[0015] In the first embodiment, the reason why the conversion rate of the fluorine-containing compound (A1) is excellent is not entirely clear, but the present inventors presume the following. As a feature of the first embodiment, there is the use of an activated metal catalyst obtained by performing activation treatment on a metal catalyst. It is presumed that since the activated metal catalyst is used in reaction A, peeling of the metal contained on the activated carbon in the activated metal catalyst is less and reaction A can be sufficiently promoted, and thus the conversion rate of the fluorine-containing compound (A1) is excellent.

[0016] Hereinafter, the fluorine-containing compound (A1) and the fluorine-containing compound (A2) are described in detail. In the first embodiment, one or two or more kinds of the fluorine-containing compound (A1) can be used alone. Furthermore, the fluorine-containing compound (A2) can be one or two or more kinds alone.

[0017] -Fluorine-containing compound (A1)- The fluorine-containing compound (A1) is a compound represented by formula (A1).

[0018] X a F2C-R f-CX a 3(A1)

[0019] In formula (A1), X a Each independently represents a hydrogen atom, a fluorine atom or a chlorine atom. a Medium, 0 or 1 X a represents a fluorine atom, at least one X a Represents a chlorine atom. f represents a fluoroalkylene group. Multiple Xs a Can be the same or different. For X a , preferably 4 X a 0 or 1 X a represents a fluorine atom, 1 to 3 X a Represents a chlorine atom, 0 to 3 X a represents a hydrogen atom, more preferably 4 X a 0 or 1 X a represents a fluorine atom, 2 or 3 X a Represents a chlorine atom, 0 to 2 X a Represents a hydrogen atom. R f The fluoroalkylene group represented is an alkylene group having at least one fluorine atom. The fluoroalkylene group may be linear, branched, or cyclic, but is preferably linear. The number of carbon atoms in the fluoroalkylene group is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. The number of fluorine atoms in the fluoroalkylene group is preferably equal to or greater than the number of carbon atoms in the fluoroalkylene group, more preferably 1.8 to 2.0 times the aforementioned number of carbon atoms, further preferably 2.0 times the aforementioned number of carbon atoms. The fluoroalkylene group is preferably a perfluoroalkylene group, and more preferably a difluoromethylene group.

[0020] As the fluorine-containing compound (A1), 214cb, 224ca, 224cc, 234cc, 234cb, 244cc, 244ca, 215ca, 225cb, 225cc, 235cc, 235ca, 215cb, 225ca or 235cb is preferred, 214cb, 224ca, 224cc, 234cc, 234cb, 244cc, 244ca, 225cb, 225cc, 235cc, 235ca, 225ca or 235cb is more preferred, and 214cb, 224ca, 224cc, 234cc, 234cb, 244cc, 244ca, 225cb, 225cc, 235cc, 235ca, 225ca or 235cb is still more preferred. ca, 234cc, 234cb, 244cc, 244ca, 225cb, 225cc, 235cc, 235ca, 225ca or 235cb, further preferably 224ca, 234cc, 234cb, 244cc, 244ca, 225cb, 225cc, 235cc, 235ca, 225ca or 235cb, particularly preferably 234cc, 234cb, 244cc, 244ca, 225cb, 225cc, 235cc, 235ca, 225ca or 235cb.

[0021] The fluorinated compound (A1) may be a mixture containing two or more fluorinated compounds among the fluorinated compounds exemplified as the above-mentioned fluorinated compound (A1). Examples of the above-mentioned mixture include: a mixture comprising at least two fluorine-containing compounds selected from 214cb, 224ca, 224cc, 234cc, 234cb, 244cc and 244ca; a mixture comprising at least two fluorine-containing compounds selected from 215ca, 225cb, 225cc, 235cc and 235ca; and a mixture comprising at least two fluorine-containing compounds selected from 215cb, 225ca and 235cb. Among them, the above-mentioned mixture is preferably a mixture of at least two fluorine-containing compounds selected from 234cc, 234cb, 244cc and 244ca, a mixture of at least two fluorine-containing compounds selected from 225cb, 225cc, 235cc and 235ca, or a mixture of fluorine-containing compounds including 225ca and 235cb.

[0022] -Fluorine-containing compound (A2)- The fluorinated compound (A2) is a compound in which at least one of the chlorine atoms in the fluorinated compound (A1) is substituted with a hydrogen atom. The fluorinated compound (A2) is preferably a compound in which 1 to 3 of the chlorine atoms in the fluorinated compound (A1) are substituted with hydrogen atoms, and more preferably a compound in which 1 or 2 of the chlorine atoms in the fluorinated compound (A1) are substituted with hydrogen atoms. Furthermore, the number of chlorine atoms in the fluorinated compound (A2) is preferably 0 to 2, and more preferably 0 or 1.

[0023] Next, while showing the manufacturing flow chart, the R f An example of a method for producing a fluorinated compound by producing a fluorinated compound (A2) from a difluoromethylene fluorinated compound (A1) will be described in detail. As described above, in the first embodiment, the fluorinated compound (A1) is reacted with hydrogen in a gas phase to produce the fluorinated compound (A2) in which at least one of the chlorine atoms in the fluorinated compound (A1) is replaced with a hydrogen atom. In the following manufacturing flow chart, the compound described on the starting point side of the arrow corresponds to the fluorinated compound (A1), and the compound described on the end point side of the arrow corresponds to the fluorinated compound (A2). In addition, a fluorinated compound (A2) can also be produced in which a plurality of chlorine atoms in the chlorinated compound (A1) are replaced with hydrogen atoms.

[0024]

Chemical Formula 1

[0025] For example, when one fluorinated compound (A1) is reacted with hydrogen, one or more fluorinated compounds (A2) can be generated from the one fluorinated compound (A1). Specifically, 224ca can be generated from 214cb, 224ca and 244cc can be generated from 214cb, and 235cc and 235ca can be generated from 225cb. Furthermore, when two or more fluorinated compounds (A1) are reacted with hydrogen, one or more fluorinated compounds (A2) can be generated from the two or more fluorinated compounds (A1). Specifically, 244cc and 244ca can be generated from 234cc and 234cb, and 244ca can be generated from 234cc and 234cb.

[0026] -hydrogen- The molar amount of hydrogen in the reaction A is preferably from 0.5 to 10.0 mol, more preferably from 0.8 to 8.0 mol, further preferably from 1.0 to 5.0 mol, per 1 mol of chlorine atoms in the fluorine-containing compound (A1). When the molar amount of hydrogen is 0.5 mol or more, the selectivity of the fluorinated compound (A2) is easily improved. In addition, when the molar amount of hydrogen is 10.0 mol or less, the selectivity of the fluorinated compound (A2) in which one or two chlorine atoms in the chlorinated compound (A1) are replaced with hydrogen atoms is easily improved. In the case of producing a fluorinated compound (A2) in which one of the chlorine atoms in the fluorinated compound (A1) is replaced by a hydrogen atom, the molar amount of hydrogen in the reaction A is preferably 0.5 to 5.0 mol, more preferably 0.8 to 3.0 mol, and further preferably 1.0 to 2.0 mol, relative to 1 mol of the chlorine atoms in the fluorinated compound (A1).

[0027] -Hydrogen chloride- Hydrogen chloride may be present in reaction A. The ratio of the volume of hydrogen chloride to the total volume of the fluorinated compound (A1), hydrogen, and hydrogen chloride in Reaction A is preferably 1 to 200,000 ppm by volume, more preferably 1 to 100,000 ppm by volume, further preferably 100 to 10,000 ppm by volume, particularly preferably 150 to 5,000 ppm by volume, and most preferably 200 to 2,000 ppm by volume. When the volume ratio of hydrogen chloride is below the above upper limit, hydrogen chloride will not be adsorbed on the active sites of the activated metal catalyst, and the conversion rate of the fluorinated compound (A1) will be easily improved. In addition, when the volume ratio of hydrogen chloride is above the above lower limit, the selectivity of the fluorinated compound (A2) will be easily improved. The volume of hydrogen chloride can be measured by, for example, ion chromatography. Examples of a method for adjusting the volume of hydrogen chloride include a method of increasing hydrogen chloride and a method of removing hydrogen chloride by the purification step in the second embodiment.

[0028] -Other ingredients- In the method for producing a fluorinated compound, when the fluorinated compound (A1) is reacted with hydrogen, other components besides the fluorinated compound (A1) and hydrogen may be present. In other words, when the fluorinated compound (A1) is reacted with hydrogen, the reaction may be carried out in the presence of other components. Examples of other components include impurities such as HFC, raw materials for producing the fluorinated compound (A1), and by-products other than the fluorinated compound (A1) produced during the production of the fluorinated compound (A1). The impurities are preferably as small as possible. Examples of methods for removing the impurities include distillation, reduced pressure distillation, azeotropic distillation, membrane separation, layer separation, and adsorption.

[0029] (Activation treatment) -Activated Metal Catalyst- The activated metal catalyst is a catalyst obtained by heating a metal catalyst comprising activated carbon and a metal supported on the activated carbon at 175 to 250° C. in the presence of oxygen and a diluent gas, wherein the ratio of the volume of oxygen to the total volume of the oxygen and the diluent gas is 0.01 to 21% by volume. In other words, the activated metal catalyst is a metal catalyst that has been subjected to an activation treatment.

[0030] The heating temperature for the activation treatment is 175 to 250°C, preferably 200 to 250°C. The heating time for the activation treatment is preferably 0.5 to 100 hours, more preferably 1 to 100 hours. When the heating temperature is not more than the upper limit, it is preferable from the viewpoint of suppressing metal peeling, and when the heating temperature is not less than the lower limit, it is preferable because the metal catalyst can be sufficiently activated. When the heating time is equal to or greater than the lower limit, the metal catalyst can be easily and sufficiently activated. In contrast, when the heating time is equal to or less than the upper limit, this is preferable in terms of cost. As the heating method, a known heating method can be mentioned, and a method of heating the reactor in a salt bath furnace is preferred.

[0031] The activation treatment is carried out in the presence of oxygen and a diluent gas. The ratio of the volume of oxygen gas to the total volume of oxygen gas and diluent gas is 0.01 to 21% by volume, preferably 0.01 to 10% by volume, and more preferably 0.01 to 5% by volume. When the volume ratio of oxygen is above the lower limit, the metal catalyst can be heated more efficiently. In addition, when the volume ratio of oxygen is below the upper limit, damage to the activated carbon and flaking of the metal can be further suppressed. The volume ratio of the oxygen gas can be adjusted, for example, by adjusting the flow rates of the oxygen gas and the dilution gas. The linear velocity during oxygen supply is preferably 0.001 to 12,600 cm / min, more preferably 0.5 to 6,300 cm / min, and further preferably 0.5 to 100 cm / min. The linear velocity when supplying the dilution gas is preferably 1.2 to 12,600 cm / min, more preferably 10 to 6,300 cm / min, and even more preferably 50 to 500 cm / min. When the linear velocity of the oxygen gas and the diluent gas is at least the lower limit, the metal catalyst can be sufficiently activated. When the linear velocity is at most the upper limit, the metal catalyst is less likely to be damaged. The total amount of oxygen supplied during the activation treatment is preferably 0.1 to 2.0 mmol / g, more preferably 0.2 to 1.5 mmol / g, per 1 g of the activated metal catalyst. When the total amount of oxygen supplied is greater than or equal to the lower limit, the metal catalyst can be more easily activated. Furthermore, when the total amount of oxygen supplied is less than or equal to the upper limit, metal flaking can be more easily suppressed. Examples of the diluent gas include nitrogen, carbon dioxide gas, helium, and argon. Nitrogen, helium, and argon are preferred, and nitrogen is more preferred in terms of cost.

[0032] The metal catalyst used for activation treatment may be dried in advance. The conditions for the drying treatment are not particularly limited, but conditions that reduce the water content of the metal catalyst are preferred. The heating temperature for the drying treatment is preferably 100 to 170°C, more preferably 100 to 150°C. Examples of the drying treatment include vacuum drying and drying with a dilute gas. The drying treatment is preferably performed in a dilute gas atmosphere, more preferably in a nitrogen atmosphere. Furthermore, the drying treatment is preferably not performed in an oxygen atmosphere. The pressure of the drying treatment may be any of normal pressure, increased pressure, and reduced pressure. The metal catalyst is preferably dried until the water content in the dilution gas after contact with the metal catalyst is 20 ppm by volume or less relative to the total volume of the dilution gas and water. In other words, the crude gas after passing through the reactor is preferably dried until the water content in the crude gas is 20 ppm by volume or less relative to the total volume of the crude gas.

[0033] The metal specific surface area of ​​the activated metal catalyst calculated by the pulse adsorption method using carbon monoxide is preferably 1.0 m2 per 1 g of metal supported on the activated carbon. 2 / g or more, and more preferably 4.0m / g from the viewpoint of a better conversion rate of the fluorinated compound (A1). 2 / g or more, more preferably 10.0m 2 / g or more, particularly preferably 13.0m 2 The upper limit of the metal specific surface area is preferably 50.0 m2 per 1 g of metal supported on the activated carbon. 2 / g or less, more preferably 40.0m 2 / g or less. The metal specific surface area of ​​the activated metal catalyst can be measured, for example, by the following method. ·Device: Belcat-II manufactured by Macchik Bayer Co., Ltd. Sample amount: 3.0 g activated metal catalyst ·Measurement steps: Place the sample in the device and allow helium to flow at 50 sccm for 20 minutes at 130°C to dry the sample. Thereafter, perform a reduction treatment at 130°C with hydrogen at 50 sccm for 30 minutes, and further perform atmosphere replacement at -15°C with helium at 50 sccm for 20 minutes. For the obtained sample, helium is flowed at 50 sccm, and a mixed gas of 10% by volume carbon monoxide and 90% by volume helium is flowed 10 times at a pulse interval of 10 minutes (1 sccm / pulse), so that carbon monoxide is adsorbed on the surface of the metal in the activated metal catalyst, and the amount of carbon monoxide adsorbed is measured. Carry out the above measurement 3 times, take the average value, and use the following formula to calculate the metal specific surface area. Metal specific surface area [m 2 / g] = {(amount of carbon monoxide adsorbed [mol]) × (cross-sectional area of ​​the metal that adsorbs 1 mol of carbon monoxide [m 2 / mol])} / metal amount in activated metal catalyst [g] When the metal is palladium, the cross-sectional area of ​​the metal that adsorbs 1 mol of carbon monoxide [m 2 / mol] is 0.0787.

[0034] The metal catalyst includes activated carbon and a metal supported on the activated carbon.

[0035] Examples of activated carbon include activated carbon obtained from plant materials such as wood, charcoal, fruit shells, and coconut shells, and mineral materials such as peat, lignite, and coal. From the viewpoint of durability of the activated metal catalyst, activated carbon obtained from plant materials is preferred, and activated carbon obtained from coconut shells is more preferred. The shape of the activated carbon is not particularly limited, but examples thereof include a 2- to 10-mm-long shaped shape, a 4- to 50-mesh crushed shape, and a granular shape.

[0036] The metal is not particularly limited, but includes metals of Group 4 elements such as zirconium, metals of Group 6 elements such as molybdenum, metals of Group 7 elements such as rhenium, metals of Group 8 elements such as iron, ruthenium and osmium, metals of Group 9 elements such as cobalt, rhodium and iridium, metals of Group 10 elements such as palladium, nickel and platinum, and metals of Group 11 elements such as gold. Among them, the metal is preferably at least one metal selected from platinum, palladium, rhodium, ruthenium, nickel, rhenium, molybdenum and zirconium, more preferably at least one metal selected from palladium and platinum, and still more preferably palladium, from the viewpoint of excellent conversion of the fluorine-containing compound (A1).

[0037] The activating metal catalysts may be used alone or in combination of two or more. The amount of metal supported in the activating metal catalyst is preferably 0.1 to 10.0% by mass, more preferably 0.5 to 3.0% by mass, further preferably 1.0 to 3.0% by mass, and particularly preferably 1.5 to 2.5% by mass, relative to the total mass of the activated carbon. When the metal loading is 0.1% by mass or more, the conversion rate of the fluorinated compound (A1) is more easily improved. When the metal loading is 10.0% by mass or less, it is easier to suppress excessive temperature rise of the activated metal catalyst due to reaction heat and to suppress the formation of by-products.

[0038] (Reaction A) In the reaction A, the fluorine-containing compound (A1) is reacted with hydrogen in the presence of an activated metal catalyst in a gas phase.

[0039] In reaction A, the fluorine-containing compound (A1) is reacted with hydrogen in a reactor. For example, the reaction of the fluorinated compound (A1) and hydrogen is carried out by supplying the fluorinated compound (A1) and hydrogen to a reaction site where an activated metal catalyst is provided. Examples of the reaction site where an activated metal catalyst is provided include a reactor containing an activated metal catalyst. The method of supplying a fluorinated compound (A1) and reacting with hydrogen into a reactor accommodating an activated metal catalyst will be described in detail below.

[0040] Reaction A is a gas phase reaction. Reaction A includes a method of supplying a raw material fluorine-containing compound (A1) and hydrogen heated to a gaseous state into a reactor and contacting the fluorine-containing compound (A1) with hydrogen in the presence of an activated metal catalyst filled in the reactor to obtain the fluorine-containing compound (A2). In view of flow rate adjustment, suppression of by-products, and suppression of deactivation of the activated metal catalyst, a diluent gas may be supplied to the reactor in reaction A. Examples of the diluent gas include nitrogen, carbon dioxide gas, helium, and argon. The diluent gas may be used alone or in combination of two or more.

[0041] When a diluent gas is used in Reaction A, the amount of diluent gas supplied to the reactor is preferably 0.1 mol or more, more preferably 0.5 mol or more, relative to 1.0 mol of the fluorinated compound (A1), from the perspective of easily maintaining the maximum temperature of the activated metal catalyst at a low level, suppressing the formation of by-products, suppressing the degradation of the activated metal catalyst, and maintaining the activity of the activated metal catalyst. From the perspective of the recovery rate of the diluent gas, the upper limit of the amount of diluent gas supplied is preferably 10.0 mol or less, more preferably 5.0 mol or less, and even more preferably 3.0 mol or less, relative to 1.0 mol of the fluorinated compound (A1).

[0042] From the viewpoint of more efficient production of the fluorinated compound (A2), the reaction temperature of Reaction A (temperature in the reactor) is preferably 150°C or higher, more preferably 150 to 350°C, further preferably 160 to 300°C, particularly preferably 180 to 270°C. When the reaction temperature is 150° C. or higher, the conversion rate of the fluorinated compound (A1) is easily increased. When the reaction temperature is 350° C. or lower, the formation of by-products and the degradation of the activated metal catalyst are easily suppressed. The reaction temperature can be controlled by regulating the temperature and pressure of the raw materials supplied to the reactor. In addition, as needed, auxiliary heating can be carried out in the reactor by an electric heater or a microwave generator.

[0043] The contact time (reaction time) of the fluorinated compound (A1) and hydrogen in the reactor is not particularly limited, but is preferably 0.01 to 150 seconds, more preferably 4 to 120 seconds, and even more preferably 8 to 100 seconds. When the contact time is at least the above lower limit, the conversion rate of the fluorinated compound (A1) tends to be excellent. On the other hand, when the contact time is at most the above upper limit, the generation of by-products tends to be suppressed. The contact time can be controlled by adjusting the amount (flow rate) of the fluorine-containing compound (A1) and hydrogen supplied to the reactor.

[0044] The pressure in the reactor may be either normal pressure or pressurized pressure, but normal pressure is preferred from the viewpoint of ease of industrial implementation.

[0045] Examples of the reactor include a glass reactor, an SUS reactor, a glass-lined reactor, and a resin-lined reactor. The reactor may be equipped with a temperature control unit for controlling the temperature inside the reactor. The temperature control unit may be any unit capable of controlling the reaction temperature of reaction A, and an oil bath may be mentioned. The temperature control unit may be integrated with the reactor.

[0046] An activated metal catalyst is contained in the reactor, and an activated metal catalyst layer can be formed as a reaction site. The activated metal catalyst may be either a fixed bed type or a fluidized bed type. Furthermore, the fixed bed type may be either a horizontal fixed bed type or a vertical fixed bed type. Of these, a vertical fixed bed type is preferred from the perspective of achieving a uniform concentration distribution of the components constituting the mixed gas at various locations due to differences in specific gravity in the mixed gas.

[0047] When the activated metal catalyst is filled in the reactor of the vertical fixed bed type, the activated metal catalyst can be charged from the upper portion of the reactor. At this time, attention is paid so that the impact of the activated metal catalyst charged from the upper portion of the reactor when it reaches the bottom surface of the reactor does not cause breakage of the catalyst. Specifically, when the length in the vertical direction from the bottom surface of the reactor to the charging port is set as h [m], the acceleration of gravity is set as g [m / s 2 ], and the maximum value of the falling speed of the catalyst from the upper portion of the reactor until it reaches the bottom surface is set as v [m / s], v preferably satisfies the following relation of formula (V).

[0048] 0 < v ≤ (2 x g x h) 0.5 (V)

[0049] The method of supplying the fluorine-containing compound (Al) and hydrogen to the activated metal catalyst layer preferably supplies them separately through different pipes into the reactor, mixes them near the inlet of the reactor, and makes them flow through the activated metal catalyst layer from the inlet side to the outlet side of the reactor. Further, the above-mentioned method of supply also preferably mixes the fluorine-containing compound (Al) and hydrogen in advance and makes them flow through the activated metal catalyst layer from the inlet side to the outlet side of the reactor.

[0050] The first embodiment can be either of a batch type and a continuous type. In the case where the first embodiment is the batch type, one of the fluorine-containing compound (Al) and hydrogen can be supplied into the reactor after the other is supplied into the reactor. In the case where the first embodiment is the continuous type, the fluorine-containing compound (Al) and hydrogen can be continuously supplied into the reactor at a prescribed supply rate in a prescribed molar ratio so that they contact each other for a prescribed time in the reactor. One of the fluorine-containing compound (Al) and hydrogen can be supplied first, and the other can be supplied thereafter, or both can be supplied at the same time. In the case where one of the fluorine-containing compound (Al) and hydrogen is supplied first, the fluorine-containing compound (Al), hydrogen, and activated metal catalyst can be made to contact each other for a prescribed time by making the component supplied first to stay in the reactor and then supplying the other component into the reactor. Further, in the case where the fluorine-containing compound (Al) and hydrogen are simultaneously supplied into the reactor, the supply of the fluorine-containing compound (Al) and hydrogen into the reactor can be performed through different supply pipes or can be performed through one supply pipe after being mixed in advance. Further, in the initial stage of the supply of the fluorine-containing compound (Al), since adsorption heat is generated between the fluorine-containing compound (Al) and the activated metal catalyst, it is preferable to supply the fluorine-containing compound (Al) first and then supply hydrogen after the adsorption heat has dissipated from the viewpoint of controlling the reaction temperature. In the continuous type, the supply rate of the fluorine-containing compound (Al) and hydrogen into the reactor can be adjusted by the supply flow rate of each compound.

[0051] The generated gas discharged from the outlet of the reactor contains the fluorine-containing compound (A2). Furthermore, the exhaust gas may contain, in addition to the fluorine-containing compound (A2), the fluorine-containing compound (A1) used as a raw material, hydrogen, various by-products, and hydrogen chloride.

[0052] Reaction A can be carried out two or more times. In the first embodiment, when reaction A is carried out two or more times, when the fluorinated compound (A2) obtained after producing the fluorinated compound (A2) from the fluorinated compound (A1) by the first reaction A contains a compound equivalent to the fluorinated compound (A1), it is preferred to further carry out reaction A directly or after carrying out the purification step described later.

[0053] In the first embodiment, when the activated metal catalyst is extracted from the reactor after reaction A, in order to prevent the combustion of the activated metal catalyst, it is preferred to fully purge the activated metal catalyst with hydrogen at a temperature above 150°C, then add water to the reactor at a temperature below 100°C, and extract the activated metal catalyst while increasing the water content of the activated metal catalyst.

[0054] <Second embodiment> The second embodiment is a method for producing a fluorine-containing compound, which comprises: Reaction step X, comprising reacting a fluorinated compound (B1) represented by formula (B1) with hydrogen in a gas phase in the presence of a first activated metal catalyst to obtain a composition comprising a fluorinated compound (B2) having at least one chlorine atom in which at least one chlorine atom in the fluorinated compound (B1) is replaced with a hydrogen atom, and hydrogen chloride; a purification step, wherein a purified product is obtained by removing at least a portion of the hydrogen chloride from the composition; and Reaction step Y, comprising reacting the fluorinated compound (B2) in the purified product with hydrogen in the gas phase in the presence of a second activated metal catalyst to obtain a fluorinated compound (B3) in which at least one of the chlorine atoms in the fluorinated compound (B2) is replaced with a hydrogen atom; The first activated metal catalyst and the second activated metal catalyst are obtained by heating a metal catalyst comprising activated carbon and a metal supported on the activated carbon at 175 to 250° C. in the presence of oxygen and a diluent gas. The ratio of the volume of oxygen gas to the total volume of oxygen gas and diluent gas is 0.01 to 21 volume %.

[0055] The second embodiment is a production method in which, after reacting the raw material fluorine-containing compound with hydrogen, the resulting composition is purified to obtain a purified product, and the fluorine-containing compound in the purified product is further reacted with hydrogen. Specifically, this production method comprises at least reaction step X and reaction step Y, which involve a hydrogen reduction reaction, and includes a purification step between reaction steps X and Y. As in the first embodiment, the reason why the conversion rate of the fluorinated compound (B1) is excellent in the second embodiment is presumably because an activated metal catalyst is used and a purification step described later is carried out.

[0056] (Activation treatment) -First activated metal catalyst, second activated metal catalyst- The first activating metal catalyst and the second activating metal catalyst are the same as the above-mentioned activating metal catalyst, and the preferred forms are also the same. Furthermore, the activation treatment for obtaining the first activated metal catalyst and the second activated metal catalyst is also the same as the activation treatment for the activated metal catalyst described above, and the preferred embodiment is also the same. The first activating metal catalyst and the second activating metal catalyst may be the same or different. Furthermore, the term "same" means that the types and component ratios of the components constituting the activated metal catalyst are the same and the conditions of the activation treatment are also the same.

[0057] (Reaction Step X) Reaction process X is a process in which a fluorine-containing compound (B1) represented by formula (B1) is reacted with hydrogen in a gas phase in the presence of a first activated metal catalyst to obtain a composition of a fluorine-containing compound (B2) having at least one chlorine atom in which at least one chlorine atom of the fluorine-containing compound (B1) is replaced by a hydrogen atom, and hydrogen chloride. Reaction step X is preferably carried out under the conditions of reaction A in the first embodiment.

[0058] -Fluorine-containing compound (B1)- The fluorine-containing compound (B1) is a compound represented by formula (B1).

[0059] X b F2C-R f -CX b 3(B1)

[0060] In formula (B1), X b Each independently represents a hydrogen atom, a fluorine atom or a chlorine atom. b Medium, 0 or 1 X b represents a fluorine atom, at least 2 X b Represents a chlorine atom. f represents a fluoroalkylene group. Multiple Xs b Can be the same or different. For X b , preferably 4 X b 0 or 1 X b represents a fluorine atom, 2 or 3 X b Represents a chlorine atom, 0 to 2 X b represents a hydrogen atom, more preferably 4 X b 0 or 1 X b represents a fluorine atom, 2 X b represents a chlorine atom, 1 or 2 X b Represents a hydrogen atom. R in formula (B1) f and R in formula (A1) f The preferred embodiments are also the same.

[0061] As the fluorine-containing compound (B1), 214cb, 224ca, 224cc, 234cc, 234cb, 215ca, 225cb, 225cc, 215cb or 225ca is preferred, 224ca, 224cc, 234cc, 234cb, 225cb, 225cc or 225ca is more preferred, 234cc, 234cb, 225cb, 225cc or 225ca is further preferred, 234cc or 225cb is particularly preferred, and 225cb is most preferred. The fluorinated compound (B1) may be a mixture containing two or more fluorinated compounds exemplified as the above-mentioned fluorinated compound (B1). Examples of the above-mentioned mixture include: a mixture comprising at least two fluorine-containing compounds selected from 214cb, 224ca, 224cc, 234cc and 234cb; a mixture comprising at least two fluorine-containing compounds selected from 215ca, 225cb and 225cc; and a mixture comprising at least two fluorine-containing compounds selected from 215cb and 225ca. Among them, the mixture is preferably a mixture containing at least two fluorine-containing compounds selected from 234cc and 234cb, a mixture containing at least two fluorine-containing compounds selected from 225cb and 225cc, or a mixture containing 225ca.

[0062] -Fluoro compound (B2)- The fluorinated compound (B2) is a compound having at least one chlorine atom in which at least one of the chlorine atoms in the fluorinated compound (B1) is substituted with a hydrogen atom. The fluorinated compound (B2) is preferably a compound having at least one chlorine atom in which 1 to 3 of the chlorine atoms in the fluorinated compound (B1) are substituted with hydrogen atoms, and more preferably a compound having at least one chlorine atom in which 1 or 2 of the chlorine atoms in the fluorinated compound (B1) are substituted with hydrogen atoms. Furthermore, the number of chlorine atoms in the fluorinated compound (B2) is preferably 1 or 2, and more preferably 1.

[0063] (Purification process) The purification step is a step of obtaining a purified product by removing at least a portion of hydrogen chloride from the composition obtained in the reaction step X. By performing the purification step, the content of hydrogen chloride in the composition can be reduced. Examples of methods for removing hydrogen chloride include alkali washing, water washing, and anhydrous sodium carbonate washing. As the alkali cleaning, a method of passing the treated material through an alkali cleaning tower is preferred. Specifically, an absorbing liquid containing an aqueous alkaline solution is sprayed from the upstream side of the flow direction of the treated object containing hydrogen chloride, and hydrogen chloride is neutralized by gas-liquid contact to remove hydrogen chloride from the treated object. Furthermore, the purification process may include other purification treatments in addition to the above-mentioned treatments. Other purification treatments include dehydration using molecular sieves or the like and distillation purification. As for the distillation purification, when a component having a standard boiling point lower than that of the fluorinated compound (B2) (low-boiling-point component) forms an azeotropic composition with water or forms an azeotropic-like composition with water, the low-boiling-point component can be used to remove water from the composition obtained in the reaction step X. Examples of the low-boiling-point component include 1-fluoropropane, 2-fluoropropane, fluoromethane, difluoromethane, 1,1,1,2-tetrafluoroethane, fluoroethane, and 1,2-difluoroethane.

[0064] (Reaction Step Y) Reaction process Y is a process in which the fluorine-containing compound (B2) in the purified product is reacted with hydrogen in the gas phase in the presence of a second activated metal catalyst to obtain a fluorine-containing compound (B3) in which at least one of the chlorine atoms in the fluorine-containing compound (B2) is replaced by a hydrogen atom. Reaction step Y is preferably carried out under the conditions of reaction step X except that the fluorine-containing compound (B2) in the purified product obtained in the purification step is reacted with hydrogen in the gas phase in the presence of the second activated metal catalyst.

[0065] -Fluorinated compound (B3)- The fluorinated compound (B3) is a compound in which at least one of the chlorine atoms in the fluorinated compound (B2) is substituted with a hydrogen atom. As the fluorine-containing compound (B3), there is no particular limitation as long as it is a compound in which at least one of the chlorine atoms possessed by the fluorine-containing compound (B2) is replaced with a hydrogen atom.

[0066] In the second embodiment, reaction step X, reaction step Y, purification step, and other steps can be further carried out after reaction step Y. As the other step, a hydrogen reduction reaction that does not correspond to any of reaction A, reaction step X, and reaction step Y can be exemplified.

[0067] In the second embodiment, when the activated metal catalyst is withdrawn from the reactor after reaction step X or after reaction step Y, in order to prevent combustion of the activated metal catalyst, it is preferable to sufficiently perform hydrogen purge at a temperature of 150°C or higher, and then to introduce water into the reactor at a temperature of 100°C or lower to withdraw the activated metal catalyst in a state where the water content of the activated metal catalyst is increased. Example

[0068] Hereinafter, the present application will be described in detail with examples. Examples 1, 3, 6, 8, 12, 15, and 16 are comparative examples, and the others are examples. However, the present application is not limited to these examples.

[0069] (Synthesis of fluorine-containing compound (Al)) <Manufacture of 224ca> First, anhydrous aluminum chloride (25 g), CHCl3(500 g), and 214cb (100 g) were added to a 500 mL stainless autoclave, and after degassing under reduced pressure while stirring, tetrafluoroethylene (TFE) was supplied until the pressure in the autoclave reached 0.05 MPa, and the autoclave was warmed to 80°C. Thereafter, while maintaining the pressure in the autoclave at 0.8 MPa, TFE was further supplied. The total amount of TFE supplied to the autoclave was 0.17 kg. Further, after stirring for 1 hour, it was cooled to room temperature, and the obtained reaction liquid was analyzed by gas chromatography. As a result, the conversion rate of CHCl3was 33%, and the selectivity of 224ca was 84%. The liquid after the reaction was filtered, and 102 g of molecular sieves 5A were added to the obtained crude liquid, and dehydration was performed by stirring overnight. The crude liquid after stirring was filtered, and the crude product was purified by distillation to manufacture 224ca (230 g).

[0070] <Manufacture of other fluorine-containing compounds> • 225cb: ASAHIKLIN AK-225G manufactured by AGC Inc. was used. • 225ca: 225ca separated by atmospheric distillation using ASAHIKLIN AK-225 (a mixture of 225ca and 225cb) manufactured by AGC Inc. through a 25-stage distillation column.

[0071] The fluorine-containing compound (Al) other than the above or the fluorine-containing compound (Bl) other than the above is obtained by atmospheric distillation in a 25-stage distillation column as needed from the product obtained by the example described later.

[0072] 〔Metal catalyst and preparation of activated metal catalyst〕 < Metal catalyst A > A cylindrical reactor (SUS 316, diameter 25 mm, length 30 cm) equipped with a salt bath furnace was filled with a palladium catalyst support (metal catalyst, 15 g) on which palladium was supported at a ratio of 2.0 mass% with respect to 100 mass% of activated carbon (crushed carbon), and was heated to 130°C while flowing nitrogen gas (100 cm / min). While maintaining the pressure in the reactor at atmospheric pressure (1 atm), drying was performed until the amount of moisture in the crude gas after the reactor reached 20 ppm by volume or less with respect to the total volume of the crude gas. After the end of drying, the supply of nitrogen gas was stopped, the reactor was heated to 200°C while supplying hydrogen (flow rate: 37 cm / min), and then 224ca (flow rate: 0.44 g / min, contact time 20 seconds) was supplied and the hydrogen reduction reaction was continuously performed for 1000 hours. The obtained metal catalyst was denoted as metal catalyst A.

[0073] < Activated metal catalyst A > A cylindrical reactor (SUS 316, diameter 25 mm, length 30 cm) equipped with a salt bath furnace was filled with metal catalyst A (15 g) again, nitrogen gas was supplied (flow rate: 60 cm / min), and the reactor was heated to 225°C. After confirming the temperature rise, oxygen gas was mixed (flow rate: 0.6 cm / min) so that the ratio of the volume of oxygen gas to the total volume of oxygen gas and nitrogen gas was 1 vol%, and heating treatment (equivalent to activation treatment) was performed for 60 minutes to obtain activated metal catalyst A.

[0074] < Metal catalyst B > A gas phase reactor (made of SUS316, 25 mm in diameter, 30 cm in length) consisting of a cylindrical reaction tube equipped with a salt bath furnace was filled with a palladium catalyst support (metal catalyst, 15 g) loaded with palladium at a ratio of 2.0% by mass relative to 100% by mass of activated carbon (crushed carbon). The temperature was raised to 130°C while nitrogen gas (100 cm / min) was flowing. While maintaining the pressure within the reactor at atmospheric pressure (1 atmosphere), the crude gas after passing through the reactor was dried until the moisture content in the crude gas reached 20 volppm or less relative to the total volume of the crude gas, thereby obtaining Metal Catalyst B. Furthermore, unlike the metal catalyst A, the metal catalyst B is a metal catalyst that is not used for hydrogen reduction reaction.

[0075] Activated Metal Catalyst B1 After drying was completed during the preparation of Metal Catalyst B, the reactor was continuously heated to 225°C. After confirming the temperature rise, the nitrogen flow rate was changed to 60 / min, and oxygen (flow rate: 0.6 cm / min) was mixed in so that the volume of oxygen relative to the total volume of oxygen and nitrogen reached 1% by volume. Heat treatment (equivalent to activation treatment) was performed for 30 minutes to obtain activated Metal Catalyst B1.

[0076] <Activated Metal Catalyst B2> Activated metal catalyst B2 was obtained by the same procedure as that for activated metal catalyst B1 except that the heating time was changed to 60 minutes.

[0077] <Activated Metal Catalysts B3 and B4> Activated metal catalysts B3 and B4 were obtained by the same procedure as that for activated metal catalyst B1 except that the heating conditions were changed to those shown in the table.

[0078] <Metal Catalysts C1 and C2> Metal catalysts C1 and C2 were obtained by the same procedure as for the activated metal catalyst B2 except that the heating temperature was changed to that shown in the table.

[0079] <Activated Metal Catalysts C1 and C2> Activated metal catalysts C1 and C2 were obtained by the same procedure as for the activated metal catalyst B2 except that the heating conditions were changed to those shown in the table.

[0080] (Metal Specific Surface Area of ​​Each Metal Catalyst and Each Activated Metal Catalyst) The metal specific surface area of ​​each metal catalyst and each activated metal catalyst was calculated by a pulse adsorption method using carbon monoxide. The measurement conditions were as described above.

[0081] [Example 1] After 1,000 hours of hydrogen reduction reaction to obtain Metal Catalyst A, the hydrogen reduction reaction was continued under the same conditions. The generated gas was washed with water, passed through an alkali cleaning column and molecular sieve 5A, and captured in a cold trap. The captured crude product was analyzed by gas chromatography. The gas chromatography column used was a DB-1301 (60 m length × 250 μm inner diameter × 1 μm thickness, manufactured by Agilent Technologies). The conversion rate of the starting compound and the selectivity of the generated compound shown below were calculated. Furthermore, the metal content of the metal catalyst after the hydrogen reduction reaction was measured.

[0082] <Conversion rate of raw material compound> Conversion rate of raw material compound (%) = {(amount of raw material compound supplied to the reactor (mol) - amount of raw material compound contained in the generated gas (mol)) / amount of raw material compound supplied to the reactor (mol)} × 100

[0083] <Selectivity of generated compounds> Selectivity of product compound (%) = {amount of each product compound contained in the product gas (mol) / amount of raw material compound consumed in the reaction (mol)} × 100

[0084] <Metal content after reaction> In Example 1, the metal content of the metal catalyst used in the above reaction was measured. The metal content (mass %, supported amount) relative to 100 mass % of the activated carbon (crushed carbon) was measured by dissolving the metal catalyst with aqua regia and titrating the obtained solution with potassium iodide.

[0085] [Example 2] After obtaining the activated metal catalyst A, nitrogen (flow rate: 102 cm / min) continues to flow through, and at the same time, the reactor is heated to 200°C in a salt bath furnace, and then hydrogen (flow rate: 37 cm / min) and 224ca (flow rate: 0.44 g / min, contact time 20 seconds) are supplied to carry out a hydrogen reduction reaction. The resulting gas was washed with water, passed through an alkali cleaning tower and molecular sieve 5A, and collected in a cold trap. The collected crude product was analyzed by gas chromatography in the same manner as in Example 1 to calculate the conversion of the starting compound and the selectivity of the product compound. Furthermore, in the same manner as in Example 1, the metal content of the activated metal catalyst after the hydrogen reduction reaction was measured.

[0086] [Example 3] After drying in the preparation of metal catalyst B, the nitrogen supply was continuously stopped, and the reactor was heated to 190°C while supplying hydrogen (flow rate: 37 cm / min). Then, 225 cb (flow rate: 0.44 g / min, contact time 20 seconds) was supplied and hydrogen reduction reaction was carried out. The resulting gas was washed with water, passed through an alkali cleaning tower and molecular sieve 5A, and collected in a cold trap. The collected crude product was analyzed by gas chromatography in the same manner as in Example 1 to calculate the conversion of the starting compound and the selectivity of the product compound. Furthermore, in the same manner as in Example 1, the metal content of the metal catalyst after the hydrogen reduction reaction was measured.

[0087] [Example 4] After obtaining the activated metal catalyst B1, nitrogen (flow rate: 102 cm / min) continued to flow through, and at the same time, the reactor was heated to 190°C by a salt bath furnace, and then hydrogen (flow rate: 37 cm / min) and 225cb (flow rate: 0.44 g / min, contact time 20 seconds) were supplied to carry out hydrogen reduction reaction. The resulting gas was washed with water, passed through an alkali cleaning tower and molecular sieve 5A, and collected in a cold trap. The collected crude product was analyzed by gas chromatography in the same manner as in Example 1 to calculate the conversion of the starting compound and the selectivity of the product compound. Furthermore, in the same manner as in Example 1, the metal content of the activated metal catalyst after the hydrogen reduction reaction was measured.

[0088] [Example 5~Example 17] Except for changing the conditions to those shown in the table below, Examples 5 and 9 to 15 were performed with the same steps as Example 4, Examples 6 and 16 were performed with the same steps as Example 1, Examples 7 and 17 were performed with the same steps as Example 2, and Example 8 was performed with the same steps as Example 3.

[0089] [Example 18~Example 25] Examples 18 to 25 were carried out in the same manner as in Example 5, except that the raw material compounds and reaction temperature were changed to those shown in the table below, hydrogen chloride was supplied until a predetermined hydrogen chloride concentration was reached, and the raw material compounds were reacted with hydrogen (hydrogen reduction reaction).

[0090] [Example 26 and Example 28] For Example 26 and Example 28, except that the raw material compound and reaction temperature are changed to those shown in the table below, the first hydrogen reduction reaction is carried out in the same manner as in Example 5. The generated gas obtained is washed with water and then captured in a cold trap by passing through an alkali cleaning tower and molecular sieve 5A. The chlorine concentration in the captured crude product is measured by ion chromatography (Dionex ICS-5000+ hybrid HPIC). In addition, gas chromatography analysis is performed in the same manner as in Example 1 to obtain the composition ratio of the product. Afterwards, the crude product was used as the raw material compound, and a second hydrogen reduction reaction was carried out under the same conditions as the first hydrogen reduction reaction, except that the reaction temperature was set to 220°C. The resulting gas was washed with water and then passed through an alkali cleaning tower and molecular sieve 5A and captured in a cold trap. The captured crude product was analyzed by gas chromatography in the same manner as in Example 1 to calculate the conversion rate of the raw material compound and the selectivity of the generated compound. In addition, the metal content of the activated metal catalyst after the above-mentioned hydrogen reduction reaction was measured in the same manner as in Example 1. In addition, the conversion rate of the raw material compound in Examples 26 and 28 was different from that in the other examples above and was calculated according to the following formula. Conversion rate of raw material compound (%) = {(amount (mol) of raw material compound supplied to the reactor in the first hydrogen reduction reaction - amount (mol) of raw material compound in the first hydrogen reduction reaction contained in the generated gas in the second hydrogen reduction reaction) / amount (mol) of raw material compound supplied to the reactor in the first hydrogen reduction reaction} × 100

[0091] [Example 27] Example 27 was carried out in the same manner as in Example 26, except that the generated gas obtained after the first hydrogen reduction reaction in Example 26 was not passed through the alkali cleaning tower. In addition, since the raw material compound in the second hydrogen reduction reaction in Example 27 did not pass through the alkali cleaning tower, the chlorine concentration of the raw material compound in the second hydrogen reduction reaction in Example 26 was higher.

[0092] [Example 29] Example 29 was carried out in the same manner as in Example 28, except that the generated gas obtained after the first hydrogen reduction reaction in Example 28 was not passed through the alkali cleaning tower. In addition, since the raw material compound for the second hydrogen reduction reaction in Example 29 did not pass through the alkali cleaning tower, the chlorine concentration of the raw material compound for the second hydrogen reduction reaction in Example 29 was higher than that in Example 29.

[0093] The following table shows the evaluation results. The "CO-MSA" column in Tables 1 to 3 shows the metal specific surface area of ​​each metal catalyst and each activated metal catalyst calculated by a pulse adsorption method using carbon monoxide. The column "Other compounds A" in Tables 1 to 3 shows compounds other than the produced fluorinated compound (A2). The "Other Compounds B" column in Tables 4 to 6 shows compounds other than the compounds specifically indicated in each example in Tables 4 to 6. Specifically, the "Other Compounds B" in Example 18 in Table 4 indicates a compound that does not correspond to any of 234cc, 244cc, 244ca, and 254cb. The "Other Compounds C" column in Tables 7 and 8 shows compounds other than the compounds specifically indicated in each example in Tables 7 and 8. Specifically, the "Other Compounds C" in Example 26 in Table 7 indicates a compound that does not correspond to any of 234cc, 244cc, 244ca, 254cb, and hydrogen chloride.

[0094] [Table 1]

[0095] [Table 2]

[0096] [Table 3]

[0097] [Table 4]

[0098] [Table 5]

[0099] [Table 6]

[0100] [Table 7]

[0101] [Table 8]

[0102] As shown in the above table, it was confirmed that the method for producing a fluorine-containing compound of the present invention is excellent in the conversion rate of the raw material. It was confirmed that when the heating time of the activation treatment was 1 to 100 hours, the conversion rate of the raw material was more excellent (Examples 4 and 5). It was confirmed that the conversion rate of the raw material was more excellent when the ratio of the volume of the activated oxygen gas to the total volume of the oxygen gas and the diluent gas was 0.01 to 5 volume % (Examples 9 to 11).

[0103] In addition, the entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2023-035602 filed on March 8, 2020 are cited herein as a disclosure of the present invention.

Claims

1. A method for producing a fluorine-containing compound, This is a method for producing a fluorine-containing compound, wherein a fluorine-containing compound (A1) represented by formula (A1) is reacted with hydrogen in the presence of an activated metal catalyst in a gas phase to produce a fluorine-containing compound (A2) in which at least one chlorine atom in the fluorine-containing compound (A1) is replaced with a hydrogen atom, wherein: The activated metal catalyst is obtained by heating a metal catalyst comprising activated carbon and a metal supported on the activated carbon at 175 to 250° C. in the presence of oxygen and a diluent gas. The ratio of the volume of the oxygen gas to the total volume of the oxygen gas and the dilution gas is 0.01 to 21 volume %. X a F2C-R f -CX a 3 (A1) In formula (A1), X a Each independently represents a hydrogen atom, a fluorine atom or a chlorine atom; 4 X a Medium, 0 or 1 X a represents a fluorine atom, at least one X a represents a chlorine atom; R f represents a fluoroalkylene group.

2. The method for producing a fluorine-containing compound according to claim 1, wherein The metal supported on the activated carbon is at least one selected from platinum, palladium, rhodium, ruthenium, nickel, rhenium, molybdenum and zirconium.

3. The method for producing a fluorine-containing compound according to claim 1 or 2, wherein R f It is difluoromethylene.

4. The method for producing a fluorine-containing compound according to claim 1 or 2, wherein The fluorine-containing compound (A1) is selected from 1,1,1,3-tetrachloro-2,2,3,3-tetrafluoropropane, 1,1,3-trichloro-2,2,3,3-tetrafluoropropane, 1,1,1-trichloro-2,2,3,3-tetrafluoropropane, 1,3-dichloro-1,1,2,2-tetrafluoropropane, 1,1-dichloro-2,2,3,3-tetrafluoropropane, 1-chloro-1,1,2,2-tetrafluoropropane, 1-chloro-2,2,3,3-tetrafluoropropane, 1,3,3-trichloro-1,1,2,2-tetrafluoropropane At least one of 1,2,2,3-pentafluoropropane, 1,3-dichloro-1,1,2,2,3-pentafluoropropane, 1,1-dichloro-1,2,2,3,3-pentafluoropropane, 1-chloro-1,1,2,2,3-pentafluoropropane, 1-chloro-1,2,2,3,3-pentafluoropropane, 3,3,3-trichloro-1,1,1,2,2-pentafluoropropane, 3,3-dichloro-1,1,1,2,2-pentafluoropropane and 3-chloro-1,1,1,2,2-pentafluoropropane.

5. The method for producing a fluorine-containing compound according to claim 1 or 2, wherein The reaction is further carried out in the presence of hydrogen chloride, The ratio of the volume of the hydrogen chloride to the total volume of the fluorinated compound (A1), the hydrogen, and the hydrogen chloride is 100 to 10,000 ppm by volume.

6. The method for producing a fluorine-containing compound according to claim 1 or 2, wherein The ratio of the volume of the oxygen gas to the total volume of the oxygen gas and the dilution gas is 0.01 to 5 volume %.

7. The method for producing a fluorine-containing compound according to claim 1 or 2, wherein The metal specific surface area of ​​the activated metal catalyst calculated by the pulse adsorption method using carbon monoxide is within 4.0 m2 per 1 g of metal supported on the activated carbon. 2 / g or above.

8. A method for producing a fluorine-containing compound, comprising: Reaction step X, comprising reacting a fluorine-containing compound (B1) represented by formula (B1) with hydrogen in a gas phase in the presence of a first activated metal catalyst to obtain a composition comprising a fluorine-containing compound (B2) having at least one chlorine atom in which at least one chlorine atom in the fluorine-containing compound (B1) is replaced with a hydrogen atom, and hydrogen chloride; a purification step, wherein a purified product is obtained by removing at least a portion of the hydrogen chloride from the composition; as well as Reaction step Y, wherein the fluorinated compound (B2) in the purified product is reacted with hydrogen in a gas phase in the presence of a second activated metal catalyst to obtain a fluorinated compound (B3) in which at least one of the chlorine atoms in the fluorinated compound (B2) is replaced with a hydrogen atom; The first activated metal catalyst and the second activated metal catalyst are obtained by heating a metal catalyst comprising activated carbon and a metal supported on the activated carbon at 175 to 250° C. in the presence of oxygen and a diluent gas. The ratio of the volume of the oxygen gas to the total volume of the oxygen gas and the dilution gas is 0.01 to 21 volume %. X b F2C-R f -CX b 3(B1) In formula (B1), X b Each independently represents a hydrogen atom, a fluorine atom or a chlorine atom; 4 X b Medium, 0 or 1 X b represents a fluorine atom, at least 2 X b represents a chlorine atom; R f represents a fluoroalkylene group.

9. The method for producing a fluorine-containing compound according to claim 8, wherein The metal supported on the activated carbon of the first activating metal catalyst and the second activating metal catalyst is at least one selected from platinum, palladium, rhodium, ruthenium, nickel, rhenium, molybdenum and zirconium.

10. The method for producing a fluorine-containing compound according to claim 8 or 9, wherein R f It is difluoromethylene.

11. The method for producing a fluorine-containing compound according to claim 8 or 9, wherein The fluorine-containing compound (B1) is at least one selected from 1,1,1,3-tetrachloro-2,2,3,3-tetrafluoropropane, 1,1,3-trichloro-2,2,3,3-tetrafluoropropane, 1,1,1-trichloro-2,2,3,3-tetrafluoropropane, 1,3-dichloro-1,1,2,2-tetrafluoropropane, 1,1-dichloro-2,2,3,3-tetrafluoropropane, 1,3,3-trichloro-1,1,2,2,3-pentafluoropropane, 1,3-dichloro-1,1,2,2,3-pentafluoropropane, 1,1-dichloro-1,2,2,3,3-pentafluoropropane, 3,3,3-trichloro-1,1,1,2,2-pentafluoropropane and 3,3-dichloro-1,1,1,2,2-pentafluoropropane.

12. The method for producing a fluorine-containing compound according to claim 8 or 9, wherein The reaction step Y is further carried out in the presence of hydrogen chloride, The ratio of the volume of the hydrogen chloride to the total volume of the purified product, the hydrogen, and the hydrogen chloride is 100 to 10,000 ppm by volume.

13. The method for producing a fluorine-containing compound according to claim 8 or 9, wherein The ratio of the volume of the oxygen gas to the total volume of the oxygen gas and the dilution gas is 0.01 to 5 volume %.

14. The method for producing a fluorine-containing compound according to claim 8 or 9, wherein The metal specific surface areas of the first activated metal catalyst and the second activated metal catalyst calculated by the pulse adsorption method using carbon monoxide are both within 4.0 m2 per 1 g of metal supported on the activated carbon. 2 / g or above.

Images