JP3031465B2 - Method for producing 1,1,1,3,3-pentafluoropropane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fluorinated propane by fluorinating a halogenated propane or a halogenated propene, and more particularly, to 1,1,1 useful as a foaming agent such as polyurethane foam or a refrigerant. 1,3,3
It is suitable for a method for producing 3-pentafluoropropane.

[0002]

2. Description of the Related Art As a method for producing a fluorinated propane, a corresponding chlorinated substance is fluorinated with hydrogen fluoride in the presence of a catalyst, addition of hydrogen fluoride to a halogenated propene or subsequent chlorine-fluorine exchange. And a method of converting propanes already having a fluorine atom into fluorinated propane different from the original fluorinated propane by reduction with hydrogen or chlorination with chlorine.

For example, as a method for producing 1,1,1,3,3-pentafluoropropane, CF ₃ -CC
a method of contact hydrogenating 1X-CF ₂ Cl (X represents a halogen atom) (JP-A-6-256235);
1,1,3,3,3 method pentafluoro-1-propene are hydrogenated with Pd-Al ₂ O ₃ (Izvest.Aa
d. Nauk S.D. S. S. R. , Otdel. Khi
m. Nauk. 1960, 1412-18; CA 5
5,349f), hydrogenation of 1,2,2-trichloropentafluoropropane (US Pat. No. 2,942,036)
Liquid phase fluorination of 1,1,1,3,3-pentachloropropane with hydrogen fluoride in the presence of a catalyst (US Pat. No. 5,574,192).
A method for fluorinating 1,1,3,3-pentachloropropane with hydrogen fluoride in the presence of a catalyst (JP-A-9-002998)
No. 3), 1,1,1,3,3-pentachloropropane is fluorinated in the gas phase with hydrogen fluoride in the presence of a catalyst to obtain 1-chloro-3,3,3-trifluorolopropene. Gas-phase fluorination of the same compound except hydrogen chloride by hydrogen fluoride in the presence of a catalyst
183740) and the like.

[0004]

SUMMARY OF THE INVENTION The above-mentioned JP-A-6-2
The hydrogen substitution of chlorine atom by hydrogenation described in US Pat. No. 56235 or US Pat. No. 2,942,036 is a method excellent in the reaction rate and selectivity, but the catalyst is remarkably deteriorated, and the fluorinated chlorinated material as a raw material is used. Must be prepared in advance, and there are many difficulties for industrial application. On the other hand, the method by hydrogenation to an olefin described above is an excellent method for producing 1,1,1,3,3-pentafluoropropane.
It is difficult to obtain 3,3,3-pentafluoro-1-propene and there is a problem in industrially adopting it. U
The method described in SP 5,574,192 is a liquid phase method, and has a lot of difficulties as an industrial method by a continuous method such as severe corrosion of a reactor and deterioration of a catalyst due to generation of a tar-like substance.

Further, the method disclosed in Japanese Patent Application Laid-Open No. 9-183740 discloses a method in which 1,1,1,
In this method, 1,1,1,3,3-pentafluoropropane is obtained by fluorinating 1,3,3-pentachloropropane with hydrogen fluoride, but sufficient yield is obtained under a single fluorination reaction condition. Since 1-chloro-3,3,3-trifluoropropene was obtained as an intermediate in the first-stage reaction, it was further obtained in the second-stage reaction under almost the same fluorination conditions. By fluorinating with, the yield could be increased. This is a condition in which the ratio of hydrogen fluoride / hydrogen chloride in the second-stage reaction is increased to remove the hydrogen chloride generated in the first-stage reaction and fluorinated propane is easily produced. The selectivity of 3,3-pentafluoropropane is limited to a maximum of 52.3 mol%, and the remainder is the unsaturated compound 1-chloro-3,3,3-.
Trifluoropropene and 1,3,3,3-tetrafluoropropene.

Further, fluorination of 1,1,1,3,3-pentachloropropane and 1-chloro-3,3,3-trifluoropropene (cis- and trans-forms) gives 1,1,1,3 , 3-pentafluoropropane (boiling point 1
5.3 ° C.) and 1-chloro-3,3,3
-Trifluoropropene (trans form, boiling point 21.0
C) and 1,3,3,3-tetrafluoropropene (cis form) are often contained in the target product. However, the distillative separation of 1,1,1,3,3-pentafluoropropane from these mixtures is extremely difficult because of the formation of an azeotropic composition and the content of these fluorinated propenes in the product Reducing is critical for simplification of the process.

Known gas phase fluorination catalysts for fluorinated or chlorinated fluorinated hydrocarbons include aluminum or chromium oxyfluoride prepared by fluorinating alumina and chromia, and supported catalysts supporting various metals. ing. Literature (Chemistry of Organic Fluorine Compoun
ds: 2nd Ed. (1976) Milos Hudlicky, p99), 1,1, using a catalyst in which antimony pentachloride is adsorbed on activated carbon
Hydrogen fluoride and chlorine in 2,2-tetrachloroethane
1,2,2-trichloro-1,2,2-
It is stated that trifluoroethane is obtained in a yield of 65%. EP 712826 discloses that a catalyst in which antimony pentachloride is supported on activated carbon can fluorinate 1-chloro-1,1-difluoroethane with hydrogen fluoride to form 1,1,1-trifluoroethane. Is disclosed. These can be said to provide antimony pentachloride-supported activated carbon as one of the catalysts effective for the fluorination of chlorinated ethanes.

However, when fluorinating halogenated propanes with hydrogen fluoride in the presence of a fluorination catalyst, chromium disclosed in Japanese Patent Application Laid-Open No. 9-183740, which is considered to have a remarkable fluorination activity, is disclosed. As is also seen in the case of a gas phase reaction using a catalyst as a catalyst, there is a problem that the yield of a desired fluorinated propane is reduced due to the formation of fluorinated propenes or the raw fluorinated propene remaining unreacted. Occurs. Thus, the present invention aims at suppressing the coexistence of such fluorinated propenes in the product, but these patents or documents not only describe a solution to this problem but also discuss the problem. No mention is made.

[0009]

In view of the above problems of the prior art, the present inventors have considered fluorinated propane, particularly 1,1,1,3,3- suitable for production on an industrial scale. After intensive studies on various production processes to establish a method for producing pentafluoropropane, the fluorinated propene obtained by fluorinating the corresponding halogenated propane with hydrogen fluoride in the first step was further converted into the second step. In the gas phase fluorination with hydrogen fluoride in the first step, the reaction is carried out under a pressure of normal pressure or more, and in the second step, activated carbon carrying a high valent metal halide is used as a catalyst at normal pressure or By performing the reaction under a lower pressure than in the first step, the conversion of the raw material organic matter and the selectivity of the target fluorinated propane are increased, and as a result, the target product It found that can significantly reduce the content of a distillate separation difficult raw material or intermediate product unsaturated compounds, in which have reached the present invention.

That is, the present invention is a method for producing fluorinated propane, which comprises at least the following two steps.

[0011] (a) the general formula (1) C ₃ in _{H a F b X c (1} ) ( wherein, X is independently a chlorine atom, a bromine atom or an iodine atom, a is 1 to 6, b is 0-6, c is 1
Represents an integer of 7, and a + b + c = 8. Halogenated propane or represented by the general _{formula) (2) C 3 H d} F e X f (2) ( wherein, X independently represents a chlorine atom, bromine atom or iodine atom, d is 0 to 5 , E is 0-5, f is 1
Represents an integer of 6, and d + e + f = 6. ) Is fluorinated with hydrogen fluoride to obtain a compound represented by the following general formula (3): C _{3 HgF h} X _i (3) (wherein X independently represents a chlorine atom, a bromine atom or an iodine atom) Represents, g is 0 to 5, h is 1 to 6, i is 0 to
Represents an integer of 5, and g + h + i = 6. A) obtaining a reaction product containing a fluorinated propene represented by the formula (1), wherein the first step is performed under the conditions of a pressure of 0.05 to 5.0 MPa (gauge pressure) and a temperature of 100 to 450 ° C. Yes, then, (b) transferring the reaction product obtained in the first step to a reaction zone where a catalyst composed of activated carbon supporting a high-valent metal halide is present, and fluorinating with hydrogen fluoride in a gas phase; equation _{(4) C 3 H j F} k X l (4) ( wherein, X represents independently a chlorine atom, a bromine atom or an iodine atom, j is 1 to 6, k is 2 to 7, l is 0 ~
Represents an integer of 5, and j + k + 1 = 8. A) a second step of obtaining a fluorinated propane represented by

The first step is a gas phase reaction or a liquid phase reaction, and the reaction mode of the first step and the second step performed in the gas phase reaction may be any of a fixed bed, a fluidized bed, and the like. Is preferably a flow type or semi-flow type, but may be a batch type.

[0013] The process for producing fluorinated propane of the present invention comprises:
In the first step, at least one of the halogens other than fluorine in the halogenated propane or halogenated propene is replaced with fluorine and dehydrohalogenated to obtain a fluorinated propene, and the fluorinated propene is further fluorinated in the second step To produce fluorinated propane having more fluorine atoms than the starting material.

In a preferred embodiment of the present invention, the starting material, wherein the halogenated propane represented by the general formula (1) and the halogenated propene represented by the general formula (2) do not contain halogen other than chlorine, And a method for producing a fluorinated propane in which the halogenated propene represented by the general formula (4) is a hydrofluoropropane containing no halogen other than fluorine.

The halogenated propane represented by the general formula (1) or the halogenated propene represented by the general formula (2) according to the present invention is characterized in that at least one of the hydrogen atoms of propane or propene is halogen (halogen is These compounds are substituted with chlorine, fluorine, bromine, and iodine; the same applies hereinafter), and can be used as a raw material as a mixture with each other. As a halogen other than fluorine, chlorine is most preferable for economic reasons. The halogenated propane represented by the general formula (1) is not particularly limited.
1,1,3,3,3-hexachloropropane, 1,1,
1,3,3-pentachloropropane, 1,1,1,3-
Tetrachloropropane, 1,1,2,2-tetrachloropropane, 1,1,3,3-tetrachloropropane,
1,1,3-trichloropropane, 1,1,1-trichloropropane, 1,1-dichloropropane, 1,3-dichloropropane and the like, and halogenated propane in which a part of these chlorine atoms is substituted by fluorine, For example, 1,1,
1-trichloro-3-fluoropropane, 3-chloro-
1,1,1-trifluoropropane, 3,3-dichloro-1,1,1-trifluoropropane, 1,1-dichloro-1-fluoropropane, 1,1-dichloro-3,3
-Difluoropropane, 3-chloro-1,1,1,3-
Examples thereof include tetrafluoropropane, and may be an isomer thereof, or a mixture thereof.

Further, the halogenated propene represented by the general formula (2) is not particularly limited.
For example, 1,1,2,3,3,3-hexachloropropene, 1,1,2,3,3-pentachloropropene,
1,2,3-tetrachloropropene, 1,2,3,3-
Tetrachloropropene, 1,3,3,3-tetrachloropropene, 2,3,3,3-tetrachloropropene,
1,1,3,3-tetrachloropropene, 1,1,2-
Trichloropropene, 3,3,3-trichloropropene, 3,3-dichloropropene, and the like, and halogenated propenes in which some of the chlorine atoms are substituted with fluorine, isomers thereof, and general formulas exemplified below. (3)
And a halogenated propene represented by the formula:

The fluorinated propene represented by the general formula (3) according to the present invention is a compound obtained by removing hydrogen chloride from a halogenated propane represented by the general formula (1) or represented by the general formula (2). A chlorinated propene obtained by substituting a part or all of chlorine with a fluorine atom. These may be isomers, cis-forms or trans-forms, or may be mixtures.

The reaction gas generated in the first step in the method of the present invention contains, as an organic component, a fluorinated propene represented by the general formula (3) as a main component, and hydrogen chloride and unreacted hydrogen fluoride. Consists of Naturally, since the fluorinated propene represented by the general formula (3) depends on the raw material used in the first step, it can be guessed by a person skilled in the art or can be easily known by preliminary experiments. is there.
However, in carrying out the method of the present invention, since the first step and the second step are performed continuously, it is not always necessary to accurately know the organic components contained in the reaction gas. In the method of the present invention, as the fluorinated propene represented by the general formula (3), those having a small number of halogen atoms other than fluorine are preferable, and the number of halogens other than fluorine is particularly preferably 0 to 2. .

The fluorinated propene represented by the general formula (3) according to the present invention is not particularly limited, and may be a cis or trans form, or may be a mixture. Specifically, for example, 3-chloropentafluoropropene, 2-chloropentafluoropropene, 1-chloropentafluoropropene, 1,1-dichlorotetrafluoropropene, 1,2-dichlorotetrafluoropropene, 1,3- Dichlorotetrafluoropropene, hexafluoropropene, 1-chloro-2,3,3,3-
Tetrafluoropropene, 1,3-dichloro-2,3
3-trifluoropropene, 1,2-dichloro-3,
3,3-trifluoropropene, 1,1,3,3,3-
Pentafluoropropene, 1,2,3,3,3-pentafluoropropene, 2-chloro-3,3,3-trifluoropropene, 2,3,3,3-tetrafluoropropene, 1,2,3 3-tetrafluoropropene, 1,
1,2-trifluoropropene and halogenated propene having a vinylene group exemplified below.

The fluorinated propene represented by the general formula (3) according to the present invention is preferably a compound having a vinylene group (-CH = CH-). Specifically, 3,
3,3-trifluoropropene, 3-bromo-3,3-
Difluoropropene, 3-chloro-3,3-difluoropropene, 3-fluoropropene or the compound exemplified below. C in which halogen other than fluorine is chlorine
F _3-m Cl _m CH = CY (m is an integer of 0 to 3 and Y represents a fluorine atom or a chlorine atom) is preferable, and as the fluorinated propane, CF _3-n Cl _n C
H ₂ CFYHn is an integer of from 0 to 3, Y represents a fluorine atom or a chlorine atom. ) Represented by a methylene group (-CH
_2- ) are obtained.

As the fluorinated propene represented by the general formula (3) according to the present invention, R ¹ —CH ＝ CH—R ² (wherein R ¹ represents a trihalomethyl group and R ² represents a halogen).
Is more preferable.
Specifically, 3,3,3-trichloro-1-fluoropropene, 1,3,3-trichloro-3-fluoropropene, 3,3-dichloro-1,3-difluoropropene,
1,3-dichloro-3,3-difluoropropene, 3-
Chloro-1,3,3-trifluoropropene, 3-bromo-1,3,3-trifluoropropene, 1-iodo-
3,3,3-trifluoropropene, 1-chloro-3,
Examples thereof include 3,3-trifluoropropene and 1,3,3,3-tetrafluoropropene. As a raw material in the first step or the second step, these may be mixed in any ratio. Of the above fluorinated propenes,
In particular, 1-chloro-3,3,3-trifluoropropene (trans form or cis form) and 1,3,3,3-tetrafluoropropene (trans form or cis form) are preferably employed.

The general formula (4) produced by the method of the present invention
The fluorinated propane represented by the formula (1) varies depending on the type of halogenated propane or halogenated propene used as a raw material in the first step. In the reaction in the second step, it is considered that hydrogen fluoride addition to the double bond occurs ^first , and C (Z ¹ ) ₃ -C
From (Z ² ) = C (Z ³ ) ₂ (Z ¹ , Z ² and Z ³ are each a hydrogen atom or a halogen atom), C (Z ¹ ) ₃ —CH (Z
² ) While obtaining the fluorinated propane represented by CF (Z ₂ (Z ¹ , Z ² , and Z ³ are the same as described above), while controlling the reaction conditions described below, only this addition reaction can be carried out. It is also possible to generate or to replace any remaining number of halogen atoms with fluorine atoms.

For example, R ¹ —CH ＝ CH—R ² (where R
¹ represents a trihalomethyl group, and R ² represents a halogen. )), R ³ —CH ₂ —R ⁴ (wherein R ³ is a trihalomethyl group,
R ⁴ represents a dihalomethyl group, and at least one of halogens in Table R ⁴ represents fluorine. ) Is obtained. Specifically, for example, 1,1,1,3-tetrachloro-3-fluoropropane, 1,1,1-trichloro-3,3-difluoropropane, 1,1,3-trichloro-1,3- Difluoropropane, 1,1-dichloro-1,3,3-trifluoropropane, 1,3-dichloro-1,1,3-trifluoropropane, 1-chloro-1,1,3,3-tetrachloropropane, 3-chloro-1,1,1,3-tetrafluoropropane, 1,
Examples thereof include 1,1,3,3-pentafluoropropane. When the halogen-fluorine exchange reaction is sufficiently advanced, a halogenated propene represented by R ¹ —CH ＝ CH—R ² (wherein R ¹ represents a trihalomethyl group and R ² represents a halogen) is converted to In the case of using the intermediate material in two steps, 1,1,1,3,3-pentafluoropropane can be obtained by appropriately selecting the reaction conditions.

The raw material used in the present invention can be produced by a known method. For example, 1,1,1,3,3
-Pentachloropropane is obtained by reacting vinylidene chloride and chloroform in the presence of a copper amine catalyst (M.K.
Otora et al., React. Kinet. Catal.
Lett. , 44, 2, 1991, 415. ), A method of reacting carbon tetrachloride and vinyl chloride in the presence of a copper amine catalyst (M. Kotora et al., J. Mol.
l. , 77, 1992, 51. ), A method of reacting carbon tetrachloride and vinyl chloride in the presence of a ferrous chloride catalyst (J.
Org. Chem. USSR, 3, 1969, 210
1. ).

The first step is carried out in the presence or absence of a fluorination catalyst. The fluorination catalyst according to the first step includes Group III, Group IVb, Group Vb, Group VIb or Group VI of the periodic table.
It is a metal belonging to Group Ib or Group VIII, and is used as it is or as supported on a carrier. Further, fluorinated alumina (eg, fluorinated alumina), titania, stainless steel, or the like, or activated carbon can also be used as the fluorination catalyst. Examples of the supported catalyst include a catalyst in which one or two metals selected from aluminum, chromium, manganese, nickel, and cobalt are supported on a carrier. As the carrier, alumina, fluorinated alumina, aluminum fluoride, activated carbon and the like are used. The method for preparing the catalyst is not particularly limited, but the carrier is impregnated or sprayed with a solution in which a soluble compound such as nitrate, chloride or the like is dissolved, and then dried. It can be obtained by contacting with hydrogen chloride, hydrogen chloride, chlorofluorohydrocarbon, or the like, and halogen-modifying a part or all of the supported metal or carrier. The fluorination method may be any method, for example,
Fluorinated alumina is passed through the gaseous phase with hydrogen fluoride while heating to commercially available alumina for drying or catalyst support, or spraying or immersing in an aqueous solution of hydrogen fluoride at around room temperature, It can be prepared by drying. The activated carbon used in the fluorination catalyst may be the same as the activated carbon used in the second step.

When the first step is carried out in a liquid phase, the catalyst used may be a high valent metal halide used in the second step shown below as it is, a catalyst supported on a carrier, or activated carbon.

The fluorination catalyst according to the second step of the present invention is a catalyst in which a high-valent metal halide is supported on activated carbon. Examples of the high valent metal include antimony, tantalum, niobium, molybdenum, tin, titanium, and the like. Antimony and tantalum are preferred, and antimony is most preferred. The supported high valent metal halide is
SbQ ₅ (Q independently represents fluorine, chlorine, bromine, iodine; the same applies hereinafter), TaQ ₅ , NbQ ₅ , Mo
It is a halide represented by Q ₅ , SnQ ₄ , TiQ _4, etc., must not be an oxyhalide, and containing oxygen must be avoided because it reduces the activity.

The preparation method is not particularly limited as long as the metal halide adheres to the activated carbon. Compounds that are liquid at around normal temperature, such as antimony pentachloride, tin tetrachloride or titanium tetrachloride, if necessary, may be subjected to a pretreatment of a basic substance, an acid or hot water or a dehydration treatment as described below. It can be directly attached to the applied activated carbon by a method such as dropping, spraying, dipping, or the like. When the compound is a liquid or solid compound at room temperature, it is impregnated by immersing activated carbon in a solution of the compound in a solvent, or attached to the activated carbon by a method such as spraying. Then, the activated carbon with the metal compound thus obtained is dried by heating or / and reducing the pressure, and then the activated carbon with the metal halide is dried under heating with hydrogen fluoride, chlorine, hydrogen chloride, fluorinated chloride. The catalyst is prepared by contacting with a hydrocarbon or the like. In particular, when antimony pentachloride is supported, it is preferable to activate the catalyst by treating it with at least one equivalent of chlorine at 100 ° C. or more.

The solvent may be any solvent that can dissolve the metal halide and does not decompose the metal halide at that time. Specifically, for example, methanol, ethanol,
Lower alcohols such as isopropanol; ethers such as methyl cellosolve, ethyl cellosolve and diethyl ether; ketones such as acetone and methyl ethyl ketone; aromatic compounds such as benzene, toluene and xylene; esters such as ethyl acetate and butyl acetate; Chlorinated solvents such as methylene, chloroform, tetrachloroethylene and tetrachloroethane, 1,1-dichloro-1
-Fluoroethane 3,3-dichloro-1,1,2,2
Fluorinated solvents such as 3-pentafluoropropane, 1,3-bis (trifluoromethyl) benzene, trifluoromethylbenzene, and 3-chloro-1,1,1,3
-Tetrafluoropropane, 3,3-dichloro-1,
Examples include the starting material in the method of the present invention, such as 1,1-trifluoropropane, and an intermediate or a product, such as fluorinated propane.

Examples of solvents such as antimony pentachloride, niobium pentachloride, tantalum pentachloride and molybdenum pentachloride include 3-chloro-1,1,1,3-tetrafluoropropane and 3,3-dichloro-1,1 Fluorinated solvents such as, 1,1-trifluoropropane, 1,3-bis (trifluoromethyl) benzene, and trifluoromethylbenzene are preferred. When these solvents are used or when no solvent is used, it is preferable to remove a substance having reactivity with a halide such as water from the solvent and the treatment system, and carry the substance substantially in the absence of water.

As the high valent metal halide used in the preparation of the catalyst, a halide having the highest possible valence usually available is preferred. Therefore, specifically, antimony (V: oxidation number; the same applies hereinafter), tin (IV), titanium (IV), niobium (V), tantalum (V), and molybdenum (V) are preferable. However, after the metal halide is supported on the carrier, it is usually oxidized with chlorine or the like to the highest oxidation number that can be obtained. Further, the metal compound is supported and then subjected to halogenation and / or higher oxidation to thereby increase the valence. A catalyst supporting a metal halide may be used.

The metal halide used in the preparation of the catalyst is, specifically, antimony compounds such as antimony pentachloride, antimony trichloride, antimony trichloride, antimony pentabromide, antimony tribromide, and antimony pentafluoride. Antimony halides such as antimony, antimony trifluoride and antimony triiodide can be mentioned, and antimony pentachloride can be mentioned as the most preferable one. Similarly, as tin compounds, tin tetrachloride, tin dichloride, titanium compounds, titanium tetrachloride, titanium trichloride, niobium compounds, niobium pentachloride, tantalum compounds, tantalum pentachloride, molybdenum compounds, And molybdenum pentachloride.

The supported amount of the high valent metal halide used in the preparation of the catalyst used in the present invention is 0.1 to 500 parts by weight, preferably 1 to 250 parts by weight, per 100 parts by weight of activated carbon.
Parts by weight. It is also preferable to adjust the catalytic activity by combining two or more metals. In that case, an antimony halide (especially antimony pentachloride) as a main component, another niobium compound (especially niobium pentachloride) or a tantalum compound (especially tantalum pentachloride), tin, titanium, niobium,
It is preferred to combine tantalum and molybdenum halides. The atomic ratio of the auxiliary component metal / main component metal may be 50/50 to 0/1 since the case where the auxiliary component metal is not included may be used.
00, preferably 30/70 to 0/100.

The activated carbon used as a catalyst or a carrier in the first and second steps of the present invention is a plant based on wood, charcoal, coconut shell charcoal, palm kernel charcoal, ash, etc., peat, lignite, lignite, There are coal based on bituminous coal and anthracite, petroleum residue, petroleum based on oil carbon, and synthetic resin based on polyvinylidene chloride. It is possible to use by selecting from these commercially available activated carbons. For example, activated carbon produced from bituminous coal (BPL granular activated carbon manufactured by Toyo Calgon), coconut shell charcoal (granular Shirasagi GX, G2 manufactured by Takeda Pharmaceutical Co., Ltd.)
X, SX, CX, XRC, PCB manufactured by Toyo Calgon, and the like, but are not limited thereto. The shape and size are usually used in the form of granules, but if they are suitable for a reactor such as a sphere, fiber, powder, or honeycomb, they can be used within the ordinary knowledge range.

The activated carbon used in the present invention is preferably an activated carbon having a large specific surface area. The specific surface area and the pore volume of the activated carbon are within the range of the specifications of commercial products, but are preferably larger than 400 m ² / g and larger than 0.1 cm ³ / g, respectively. In addition, each 800-3000m
² / g and 0.2 to 1.0 cm ³ / g may be used. Furthermore, when using activated carbon as a carrier, ammonium hydroxide, sodium hydroxide, or immersed in a basic aqueous solution such as potassium hydroxide at about room temperature for about 10 hours or more,
It is desirable to perform a pretreatment with an acid such as nitric acid, hydrochloric acid, hydrofluoric acid, etc., which is conventionally performed when using activated carbon as a catalyst carrier, to activate the carrier surface and remove ash in advance.

In the case where the catalyst in the second step is pretreated by any method, the catalyst is heated in advance so as not to be deteriorated by hydrolysis or the like when the high valent metal halide is carried, and the catalyst is depressurized. It is desirable to remove water as much as possible.

The catalyst of the first step or the second step prepared by any method is brought into contact with a fluorinating agent such as hydrogen fluoride, a fluorinated or fluorinated chlorinated hydrocarbon before use, and It is effective to prevent a change in the composition of the catalyst in the inside, shortening of the service life, abnormal reaction, and the like. It is preferable that the catalyst used in the second step is kept in contact with hydrogen fluoride and / or chlorine for the same reason. Also, supplying chlorine, fluorinated chlorinated or chlorinated hydrocarbon into the reactor during the reaction is effective for extending the life of the catalyst, improving the reaction rate, and improving the reaction yield. Particularly, the introduction of chlorine is preferable for improving and maintaining the catalytic activity, and is about 0.1 to 10 mol per 100 mol of the halogenated propane or the propene halide represented by the general formula (1) or (2) as a raw material. It is desirable to be accompanied.

The life of the antimony pentahalide catalyst is generally such that an antimony compound is reduced from pentavalent to trivalent by the action of a reducing agent, and when a highly polymerizable organic material is fluorinated, a high boiling organic compound is used. It is said that the compound loses the catalytic action by covering the catalyst surface or the like. These problems can be prevented by coexisting an oxidizing agent such as chlorine in the reaction system. The reaction temperature in the first step is 100 to 450 ° C., preferably 100 to 200 ° C. for the liquid phase reaction, and 150 to 350 ° C. for the gas phase reaction. Reaction temperature 100 ° C
If it is less than 450 ° C., the reaction rate is low, and if it is 450 ° C., it is difficult to maintain the catalytic activity, which is not preferable. On the other hand, the reaction temperature in the second step is from 20 to 300 ° C, preferably from 40 to 180 ° C. It is generally preferred that the reaction temperature be higher in the first step than in the second step. If the reaction temperature in the second step is lower than 20 ° C., the reagents involved in the reaction are liquefied, and the reaction is slow and not practical. If the reaction temperature is increased, the life of the catalyst is shortened, and the reaction proceeds rapidly, but decomposition products and the like are generated and the selectivity of fluorinated propane generated is undesirably reduced.

The molar ratio of the hydrogen fluoride to the halogenated propane or halogenated propene as the raw material in the first step of the present invention is not problematic as long as it is stoichiometric or more. In the case of 3,3-pentachloropropane, if the molar ratio of hydrogen fluoride / organic substance is 3 or more, the amount is sufficient for producing 1-chloro-3,3,3-trifluoropropene as a main intermediate. Generally C ₃ H _a F _b X _c
In the halogenated propane represented by the general formula (1), the amount of hydrogen fluoride may be c-1 mol or more with respect to the organic substance. Further, the halogenated propene commonly formula represented by _{C 3 H d F e X f} (2), hydrogen fluoride content may be at f mol or more with respect to organic matter. In the second step,
The molar ratio of fluorinated propene / hydrogen fluoride as the intermediate raw material to be supplied to the reaction zone is more advantageous for the product side in terms of chemical equilibrium from the viewpoint of chemical equilibrium. It becomes bigger and hinders economic efficiency. Therefore, the molar ratio of fluorinated propene / hydrogen fluoride of the intermediate material is approximately 1/1 to 1/50, preferably 1/2 to 1/1/50.
20. When the first step and the second step are performed continuously, the excess hydrogen fluoride in the first step is used as it is in the second step. Excessive amounts are not particularly problematic. In the second step, hydrogen fluoride can be further added in addition to the unreacted hydrogen fluoride used in the first step.

Hydrogen chloride generated in the reaction contained in the reaction gas in the first step is a substance that is not preferable in terms of chemical equilibrium in the reaction in the second step. It is not particularly necessary to separate and remove hydrogen chloride in between. In a general fluorination catalyst, the product composition is often determined by the ratio of hydrogen chloride to hydrogen fluoride, but in the catalyst of the second step according to the present invention, the product composition has little effect on the presence of hydrogen chloride. Some features are not received.

However, although hydrogen chloride does not participate in the reaction in the second reaction, the presence of hydrogen chloride must increase the volume of the reactor more than necessary from the viewpoint of the space velocity or contact time of the reaction substrate. There is a disadvantage that it must be done.

According to the method of the present invention, since the first step is carried out under a pressure higher than the normal pressure, the reaction product (reaction gas) itself is taken out of the reactor in a pressurized state, and the reaction product is formed. There is an advantage that the cooling required for gas-liquid separation or distillation separation of hydrogen chloride and other components contained in the product can be significantly reduced as compared with the case where the first step is performed at normal pressure.

The reaction pressure in the first step of the present invention is preferably set to about 0.05 to 5.0 MPa (gauge pressure). In the case of a gas phase reaction, the starting organic substances present in the system are particularly preferable. Since it is desirable that the intermediate substance and hydrogen fluoride do not liquefy in the reaction system and conform to the mechanical conditions of the catalyst, the pressure is more preferably 0.05 to 2.0 MPa (gauge pressure). It is preferable to carry out at about 05 to 1.0 MPa. In the case of the liquid phase, the raw material organic substance, the intermediate substance, and the hydrogen fluoride are preferably liquefied in the reaction system, so that the pressure is more preferably 0.5 to 3.0 MPa (gauge pressure). On the other hand, it is not preferable to use an unnecessarily high pressure in view of the pressure resistance, economy, etc. of the reactor.

On the other hand, since a trace amount of the high boiling organic compound produced in the first step may cause a decrease in the activity of the catalyst in the second step, it is preferable to remove a part of the organic compound. It is preferable to add a step of removing high organic compounds. The means is not particularly limited. For example, a method such as adsorption with activated carbon, absorption with sulfuric acid, solvent absorption, or liquefaction separation by cooling can be appropriately employed.

The reaction pressure in the second step of the present invention may be normal pressure, but since the reaction is assumed to be an equilibrium reaction, a pressurized system is considered to be advantageous in order to bias the reaction toward the product. Therefore, it is generally more preferable to set the pressure higher than normal pressure. In addition, since the physical adsorption effect of the reaction substrate on the catalyst surface is increased by pressurization and an increase in the reaction rate can be expected, a high pressure is preferable from this viewpoint. Since this effect is expected to be particularly prominent in an activated carbon catalyst having a large surface area, activated carbon having a large surface area is preferably used. On the other hand, a too high pressure is difficult to use because of the pressure resistance, economy, etc. of the reactor, so the reaction pressure is 0 to 5.0M.
Preferably, the pressure is about Pa (gauge pressure). In particular, it is desirable that the raw material organic substances, intermediate substances, and hydrogen fluoride present in the system do not liquefy in the reaction system and conform to the mechanical conditions of the catalyst. The pressure is more preferably 0 to 2.0 MPa (gauge pressure), and in practice, it is preferably performed at substantially normal pressure of about 0 to 1.0 MPa. Further, it is preferable that the reaction pressure in the second step be lower than the reaction pressure in the first step from the viewpoint of simplifying the process.

The contact time of the reaction according to the method of the present invention is:
When the first step is a gas phase reaction, it is usually 0.1 to 300 seconds for both the first step and the second step, and preferably 1 to 60 seconds in terms of productivity.

The reactor may be made of a material having heat resistance and corrosion resistance to hydrogen fluoride, hydrogen chloride and the like.
Stainless steel, Hastelloy, Monel, platinum and the like are preferred. It can also be made of materials lined with these metals.

Antimony pentahalide and hydrogen fluoride have been shown to corrode reactor materials. Particularly, in the liquid phase reaction, the degree of corrosion becomes remarkable because the antimony halide and hydrogen fluoride are in dynamic solid-liquid contact with the apparatus material.
In the gas phase reaction of the present invention, antimony pentahalide is present in pores in the carrier, and hydrogen fluoride is considered to be present in a gaseous state, so such conditions are not satisfied, and corrosion is extremely reduced. .

For the fluorinated propane produced by the method of the present invention, a general purification method performed on a fluorinated product of a halogenated hydrocarbon with hydrogen fluoride can be applied. For example, the reactor effluent gas consisting of organic matter containing the target product, unreacted hydrogen fluoride, and generated hydrogen chloride that flows out of the reactor is separated and extracted using the difference in solubility, such as water washing and basic solution washing. After removing the acidic gas by separation or distillation, the desired fluorinated propane can be obtained by further purifying and distilling the organic substance.

In the method of the present invention, for example, when both the first step and the second step are carried out by a gas phase reaction, a first reactor at 200 to 300 ° C. filled with fluorinated alumina, more preferably activated carbon is preferably used. A second reactor at 40 to 180 ° C. filled with activated carbon carrying antimony is connected in series, and 1,1,1,3,3-pentachloropropane and hydrogen fluoride are supplied to the inlet of the first reactor, 1, from the outlet of the second reactor
Removing the product containing 1,1,3,3-pentafluoropropane and hydrogen chloride.

When the raw material is 1,1,1,3,3-pentachloropropane, 1-chloro-
3,3,3-trifluoropropene is mainly formed,
In the second step, the reactor effluent gas containing trace amounts of 1-chloro-3,3,3-trifluoropropene and 1,3,3,3-tetrafluoropropene separates hydrogen chloride and leaves residual fluoride. A method in which hydrogen fluoride in a mixture of hydrogen and an organic substance (in this example, the hydrogen fluoride and the organic substance are dissolved with each other) is absorbed by sulfuric acid or the like, and the organic substance is washed and dried, and then purified by distillation or the like can be exemplified. It goes without saying that the method is not limited to this method.

In this organic separation by distillation, 1,1,
1-chloro-3,3,3-trifluoropropene (trans form) and 1,3,3,3-tetrafluoropropene (cis form) whose boiling points are close to 1,3,3-pentafluoropropane and which are critical components ) Are 1,1,1,
The specific volatility of 3,3-pentafluoropropane is close to 1, and it is extremely difficult to separate by ordinary distillation. However, it is possible to form an azeotropic composition by lowering the content of critical components as much as possible to separate as low boiling components. it can. 1-chloro-3,
3,3-trifluoropropene (cis form), 1,3
Other components such as 3,3-tetrafluoropropene (trans form) have a boiling point different from that of 1,1,1,3,3-pentafluoropropane and can be separated by ordinary distillation. The product can be purified and purified by the above method. In fact, according to the production method of the present invention, as shown in the examples, these difficult-to-separate components are 1,1,1,3,3-
It is easy to make the pentafluoropropane 1% or less for the selectivity of 90% or more. Therefore, purification can be performed by ordinary distillation without causing a problem such as a reduction in distillation yield due to azeotropic distillation or use of a special distillation apparatus.

Of course, the method for producing fluorinated propane of the present invention comprises the step of c) separating the fluorinated propane represented by the general formula (4) from the reaction mixture produced in the second step, A third step consisting of returning the fluorinated propene represented by (3) to the second step can be included.

Hereinafter, the present invention will be described in more detail with reference to Examples, but it should not be construed that the invention is limited thereto. In Examples and Tables, “%” of the organic composition is “area%” of the gas chromatogram.

[0055]

EXAMPLES [Catalyst Preparation Example 1] Granular coconut shell charcoal having a surface area of 1200 m ² / g and a pore size of 18 Å (granular Shirasagi G2 manufactured by Takeda Pharmaceutical Co., Ltd.) was placed in a 1-liter glass flask.
X, 4-6 mesh) 0.2 liter and 130-1
After heating to 50 ° C., water was removed by a vacuum pump.
When the distillation of water was stopped, nitrogen was introduced into the flask to adjust the pressure to normal pressure.

[Catalyst Preparation Example 2] Granular coconut shell charcoal having a surface area of 1200 m ² / g and a pore diameter of 18 Å (granular Shirasagi G2 manufactured by Takeda Pharmaceutical Co., Ltd.) was placed in a 1-liter glass flask.
X, 4-6 mesh) 0.2 liter and 130-1
After heating to 50 ° C., water was removed by a vacuum pump.
When the distillation of water was stopped, nitrogen was introduced into the flask to normal pressure, and 100 g of antimony pentachloride was introduced into the activated carbon layer while stirring with a dropping funnel for 1 hour. The activated carbon impregnated with antimony pentachloride was kept at 150 ° C. for about 1 hour and aged.

[Catalyst Preparation Example 3] Activated carbon was dried in the same manner as in Catalyst Preparation Example 2 (granular coconut shell charcoal granular Shirasagi G2X, manufactured by Takeda Pharmaceutical Co., Ltd., 0.2 liter), and 31 g of 50% niobium pentachloride / dehydrated ethanol was added. The solution was introduced with stirring in a dropping funnel for 1 hour. Activated carbon impregnated with niobium pentachloride removes ethanol under reduced pressure and then heats at 150 ° C for about 1 hour.
And aged.

[Catalyst Preparation Example 4] Activated carbon was dried in the same manner as in Catalyst Preparation Example 2 (granular coconut shell charcoal granular Shirasagi G2X, manufactured by Takeda Pharmaceutical Co., Ltd., 0.2 liter), and 48 g of 50% tantalum pentachloride / dehydrated ethanol was added. The solution was introduced with stirring in a dropping funnel for 1 hour. After removing ethanol under reduced pressure, activated carbon impregnated with tantalum pentachloride
Aged at 0 ° C.

[Example 1] A gas phase reaction apparatus comprising a cylindrical reaction tube provided with an electric furnace (first reactor: SUS316L)
(Diameter 2.5 cm, length 30 cm) was charged with 150 ml of activated carbon prepared in Catalyst Preparation Example 1 as a gas phase fluorination catalyst. The temperature of the reaction tube was raised to 200 ° C. while flowing nitrogen gas at a flow rate of about 160 ml / min, and hydrogen fluoride was entrained with the nitrogen gas at a rate of about 0.2 g / min.
The temperature of the reaction tube was raised to 250 ° C., and the supply rate of hydrogen fluoride was set to 0.75 g / min.
-Pentachloropropane was fed to the reactor at a rate of 0.42 g / min. The pressure in the system was adjusted to 0.8 MPa by a back pressure valve provided at the rear of the reactor.

Since the reaction was stable 2 hours after the start of the reaction, the product gas flowing out of the reactor was blown into water to remove the acidic gas, and then collected with a dry ice-acetone trap. The results of analyzing the collected organic matter by gas chromatography are shown in Table 1.

[0061]

[Table 1]

Example 2 In a 1 liter SUS316L autoclave equipped with a reflux condenser and a stirrer, 100 ml of the activated carbon shown in Preparation Example 1, 1, 1, 2, 2
0.3 mol (50.4 g) of tetrachloroethane was charged, the temperature was maintained at 180 ° C. while stirring, the supply rate of hydrogen fluoride was 0.75 g / min, and 1,1,1,3,3-pentachloropropane was added. Was fed to the reactor at a rate of 0.42 g / min. Although the pressure in the system increased due to the generation of hydrogen chloride as the reaction proceeded, the pressure was adjusted to 1 MPa by a back pressure valve provided at the rear of the reactor.

Since the reaction was stable 3 hours after the start of the reaction, the generated gas flowing out of the reactor was blown into water to remove the acidic gas, and then collected with a dry ice-acetone trap. The results of analyzing the collected organic matter by gas chromatography are shown in Table 1.

[Example 3] A gas phase reactor (second reactor: SUS316L) comprising a cylindrical reaction tube equipped with an electric furnace
(Diameter 2.5 cm, length 30 cm) was charged with 150 ml of the catalyst prepared in Catalyst Preparation Example 2 as a gas phase fluorination catalyst. The temperature of the reaction tube was raised to 80 ° C. while flowing nitrogen gas at a flow rate of about 160 ml / min, chlorine gas was supplied at a rate of 0.6 g / min for 1 hour, and hydrogen fluoride was supplied at a rate of about 0.2 g / min. After the temperature of the reaction tube was raised to 100 ° C., the temperature was lowered to 80 ° C., and the reaction of the product mixture from the first reactor shown in Example 1 was stabilized. Supplied.

Since the reaction was stable 2 hours after the start of the reaction, the generated gas flowing out of the reactor was blown into water to remove the acidic gas, and then collected with a dry ice-acetone trap. The results of analyzing the collected organic matter by gas chromatography are shown in Table 2.

[0066]

[Table 2]

Example 4 The reaction product flowing out of the liquid phase reactor shown in Example 2 was directly introduced into the second reactor shown in Example 3, and the reaction was carried out in the same manner.

Since the reaction was stable 2 hours after the start of the reaction, the product gas flowing out of the reactor was blown into water to remove the acidic gas, and then collected with a dry ice-acetone trap. The results of analyzing the collected organic matter by gas chromatography are shown in Table 2.

[Examples 5 and 6] Catalyst Preparation Example 3 [Example 5] and Catalyst Preparation Example 4 as a gas phase fluorination catalyst in the first reactor
Using the catalyst prepared in [Example 6], a reaction was performed in the same manner as in Example 3.

Since the reaction was stable 2 hours after the start of the reaction, the product gas flowing out of the reactor was blown into water to remove the acidic gas, and then collected with a dry ice-acetone trap. The results of analyzing the collected organic matter by gas chromatography are shown in Table 2. [Reference Example] The same reaction operation, recovery operation, and analysis as in Example 1 were performed without filling the reactor with activated carbon. Table 1 shows the results.

[0071]

According to the present invention, the method of converting a halogenated propane with hydrogen fluoride into a fluorinated propane by a two-step reaction comprising a first step and a second step is as follows. Since the reaction gas in the second step can be used as it is without treating the reaction gas, the process for intermediate purification can be omitted or simplified. (2) Since the reaction is a gas phase reaction, the structure of the reaction apparatus is simple. (3) Chlorinated products with a well-established production method can be used as raw materials. (4) Since it is a two-stage reaction, the control of the reaction is easy and the process is optimal. In addition to at least one of the effects such as easy conversion, industrially advantageous in that the composition of the reaction product of the first step can be easily adjusted since the first step is reacted at a pressure higher than normal pressure. Production method A.

Continuation of the front page (56) References JP-A-9-183740 (JP, A) JP-A-9-2983 (JP, A) JP-A-9-2984 (JP, A) JP-A-57-135046 (JP) JP-A-11-228461 (JP, A) JP-A-11-106358 (JP, A) US Pat. No. 5,681,819 (US, A) US Pat. No. 5,710,352 (US, A) US Pat. No. 5,449,842 (US, A) United Kingdom Patent Application Publication 2313118 (GB, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 17/087 C07C 17/20 C07C 19/08 CAPLUS (STN) REGISTRY (STN) WPIDS (STN)

Claims (7)

(57) [Claims] 1. The method according to claim 1, which comprises at least the following two steps:
A method for producing 1,1,3,3-pentafluoropropane . (A) 1,1,1,3,3-pentachloropropane,
1,3,3,3-tetrachloropropene and their differences
Halogenated propane or halogenated propane
By fluorination of emissions with hydrogen fluoride 1-chloro-3,3,3
-Trifluoropropene or 1,3,3,3-tetra
A first step of obtaining a reaction product containing fluoropropene , wherein the first step is performed under the conditions of a pressure of 0.05 to 5.0 MPa (gauge pressure) and a temperature of 100 to 450 ° C; 1) The reaction product obtained in the first step is transferred to a reaction zone in which a catalyst composed of activated carbon supporting a high valent metal halide is present, and is fluorinated with hydrogen fluoride in a gas phase to be 1,1,1,3. Second step to obtain 3,3-pentafluoropropane . 2. The method according to claim 1, wherein the first step is a gas phase reaction, and the reaction is performed in the presence or absence of a fluorination catalyst .
A method for producing 1,1,3,3-pentafluoropropane . 3. The method according to claim 1, wherein the first step is a liquid phase reaction and the reaction is carried out in the presence or absence of a fluorination catalyst .
A method for producing 1,1,3,3-pentafluoropropane . 4. The method according to claim 1, wherein the high-valent metal halide applied to the catalyst in the second step is a halide of antimony, tantalum or niobium .
A method for producing 3,3-pentafluoropropane . 5. The halogenated propane represented by the general formula (1) is 1,1,1,3,3-pentachloropropane, and the fluorinated propene represented by the general formula (3) is 1-chloro-
3,3,3-trifluoropropene or 1,3,3
The 1,1 according to any one of claims 1 to 4, which is 3-tetrafluoropropene, and the fluorinated propane represented by the general formula (4) is 1,1,1,3,3-pentafluoropropane. For producing 1,1,3,3- pentafluoropropane . 6. The reaction temperature of the first step is 100 to 450 ° C.
The reaction temperature of the second step is 20 to 300 ° C., the reaction temperature of the first step is higher than the reaction temperature of the second step, and the reaction pressure of the first reaction step and the second reaction step is a gauge pressure. The method for producing 1,1,1,3,3-pentafluoropropane according to any one of claims 1 to 5, wherein the pressure is 0 to 1.0 MPa. 7. The 1,1,1,3,3-pentafluoropropane according to claim 1, further comprising the following steps:
A method for producing lopan . (C) 1,1,1,1 from the reaction mixture produced in the second step
3,3-pentafluoropropane is separated, and at least 1-chloro-3,3,3-trifluoro
Propene or 1,3,3,3-tetrafluoroprope
A third step consisting in returning down to the second step.