JPH09268139A - Production of 1,1,1,3,3-pentafluoropropane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain 1,1,1,3,3-pentafluoropropane which is useful as a foaming agent for polyurethane foam or the like or as a refrigerant by using a readily available or readily predicable 1,1,1,3,3-pentachluoropropane as a raw material to effect vapor-phase fluoridation in the presence of a specific catalyst. SOLUTION: 1,1,1,3,3-Pentachluoropropane and hydrogen fluoride are subjected to vapor-phase reaction in the presence of a fluoridation catalyst. As a fluoridation catalyst, are cited one or 2 or more kinds of oxides, fluorides, chlorides or fluorochlorides of metals selected from Al, Cr, Mn, Ni and Co. Particularly, a chromium-supporting alumina catalyst is preferred, This process is industrially advantageous as it can be continuously conducted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to 1,1,1,1 useful as a foaming agent such as polyurethane foam or a refrigerant.
The present invention relates to a method for producing 3,3-pentafluoropropane.

[0002]

2. Description of the Related Art As a method for producing 1,1,1,3,3-pentafluoropropane, conventionally, CF ₃ -CClX-C
Method for catalytic hydrogenation of F ₂ Cl (JP-A-6-25623)
No. 5), 1,1,3,3,3-pentafluoro-1-
Method of hydrogenating propene with Pd-Al ₂ O ₃ (Izve
st. Akad. Nauk S.D. S. S. R. , Otd
el. Khim. Nauk. 1960, 1412-1
8; CA 55,349f), a method for hydrogenating 1,2,2-trichloropentafluoropropane (USP2)
942036), a method of fluorinating 1,1,1,3,3-pentachloropropane in the presence of a catalyst (WO
96/01797) and the like are known.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Although hydrogen replacement of chlorine atoms by hydrogenation described in US Pat. No. 56235 or US Pat. No. 2,942,366 is a method excellent in the reaction rate and the selectivity, the deterioration of the catalyst is remarkable.
Further, a fluorinated chlorinated product as a raw material must be prepared in advance, and there are many difficult points for industrial application. On the other hand, the above-mentioned method of adding hydrogen to an olefin is an excellent method for producing 1,1,1,3,3-pentafluoropropane, but it is 1,1,3,3,3 as a raw material.
It is difficult to obtain -pentafluoro-1-propene, and there is a problem in industrial application. In addition, WO9
The method described in 6/01797 is a liquid phase method, and there are many difficulties as an industrial method by a continuous method such as retention of by-products in a reactor.

[0004]

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the inventors of the present invention use industrially-scaled materials using raw materials that are easily available or easily manufactured.
As a result of extensive studies on various processes in order to establish a method for producing 1,1,3,3-pentafluoropropane, a chromium compound was used as a catalyst when the corresponding chlorinated compound was vapor-phase fluorinated with hydrogen fluoride. The inventors have found that the desired 1,1,1,3,3-pentafluoropropane can be obtained by using, and have reached the present invention.

That is, the present invention is characterized in that 1,1,1,3,3-pentachloropropane is reacted with hydrogen fluoride in the presence of a fluorination catalyst in the gas phase.
This is a method for producing 1,1,3,3-pentafluoropropane.

The 1,1,1,3,3-pentachloropropane used in the present invention is prepared by reacting vinylidene chloride with chloroform in the presence of a copper amine catalyst (M. Kot).
ora et al., React. Kinet. Catal. Le
tt. 44, No. 2, p. 415, 1991), a method of reacting carbon tetrachloride and vinyl chloride in the presence of a copper amine catalyst (M. Kotora et al., J. of Mol. C.).
atal. 77, 51, 1992), a method of reacting carbon tetrachloride with vinyl chloride in the presence of a ferrous chloride catalyst (J. Org. Chem. USSR, 3, 21).
01, 1969).

The fluorination catalyst according to the present invention is an oxide, fluoride, chloride, fluorinated chloride or oxyfluoride of one or more metals selected from aluminum, chromium, manganese, nickel and cobalt. Compound, oxychloride, oxyfluorinated chloride and the like. If multiple metals are used, it is preferred that one of them is chromium. These may also be supported on a known carrier. As the carrier, aluminum oxide, fluoride, chloride, fluorinated chloride, oxyfluoride, oxychloride, oxyfluorinated chloride, etc., or activated carbon can be used.

The method for preparing these catalysts is not limited, but when the catalyst is prepared without using a carrier, it is prepared once from a metal hydroxide precipitated from a solution of the soluble compound of the above metal using a basic substance. It can be obtained by partially or completely modifying the formed metal oxide with hydrogen fluoride, hydrogen chloride, chlorinated fluorinated hydrocarbon or the like. When used as a supported catalyst, aluminum oxide such as γ-alumina or hydrogen fluoride, hydrogen chloride, or
Impregnating or spraying a solution in which a soluble compound of one or more metals selected from chromium, manganese, nickel and cobalt is dissolved in alumina modified with halogen such as chlorinated fluorinated hydrocarbon. Is prepared in.

The amount of supported metal is 0.1 to 20 wt%, preferably 1 to 10 wt%. In the catalyst according to the present invention, an alkaline earth element such as Mg and Ca and a lanthanoid element such as La and Ce can be added as subcomponents. These are added in order to suppress recrystallization of the oxyhalide which is the carrier or the supported metal and maintain the activity. The weight ratio of the accessory component element to the supported metal is 50:50 to 99.9: 0.1, preferably 70:30 to 99: 1.

As the soluble compound, water, ethanol,
Examples thereof include nitrates, chlorides, oxides, etc. of the corresponding metals which are soluble in a solvent such as acetone. Specifically, chromium nitrate, chromium trichloride, chromium trioxide, potassium dichromate, manganese nitrate, manganese chloride, manganese dioxide, nickel nitrate, nickel chloride, cobalt nitrate, cobalt chloride and the like can be used.

The catalyst prepared by any method is treated in advance with a fluorinating agent such as hydrogen fluoride, fluorinated or fluorinated chlorinated hydrocarbon at a temperature higher than a predetermined reaction temperature before use. It is effective to prevent changes in the composition of the catalyst. Supplying oxygen, chlorine, fluorinated or chlorinated hydrocarbons, etc. into the reactor during the reaction is effective for extending the life of the catalyst, improving the reaction rate, and improving the reaction yield.

The reaction temperature is 200 to 500 ° C., preferably 300 to 450 ° C. If the reaction temperature is low, the reaction is slow and not practical. If the reaction temperature is raised, the life of the catalyst is shortened and the reaction proceeds rapidly, but olefins such as tetrafluoropropene are produced and the selectivity of 1,1,1,3,3-pentafluoropropane decreases, which is not preferable.

In the method of the present invention, the molar ratio of 1,1,1,3,3-pentachloropropane / hydrogen fluoride supplied to the reaction zone can be changed depending on the reaction temperature, but is 1/5 to
It is 1/30, preferably 1/6 to 1/15. Excessive hydrogen fluoride will hinder the reduction of the amount of organic substances to be treated and the separation of the mixture of unreacted hydrogen fluoride and the product discharged from the reaction system. As a result, the yield of the desired product decreases. However, over- or under-fluorination is not critical in large-scale production, since the low fluorinated, unreacted, or hydrogen fluoride normally associated with the product is separated from the product and recycled.

The reaction pressure is not particularly limited, but it is preferably ¹ to 10 kg / cm ² from the viewpoint of the apparatus. It is desirable to select conditions so that the raw material organic substances, intermediate substances and hydrogen fluoride present in the system are not liquefied in the reaction system.
The contact time is usually 0.1 to 300 seconds, preferably 5 to 6 seconds.
0 seconds.

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

The product containing 1,1,1,3,3-pentafluoropropane discharged from the reactor after being treated by the method of the present invention is purified by a known method to be a product.
Although the purification method is not limited, for example, the product is first washed with water or / and an alkaline solution to remove acidic substances such as hydrogen chloride and hydrogen fluoride, dried and then distilled to remove organic impurities. It can be done by excluding it.

[0017]

【Example】

[Preparation Example 1] 336 g of special grade reagent CrCl ₃ .6H ₂ O was dissolved in pure water to make 1 L. 250 ml of granular γ-alumina having a diameter of 5 mm and a surface area of 340 m ² was immersed in this solution, and left standing overnight. Next, γ-alumina was removed by filtration, kept at 100 ° C. in a hot air circulating dryer, and further dried overnight. The obtained chromium-supported alumina was equipped with an electric furnace and had a cylindrical shape of SUS316L having a diameter of 5 cm and a length of 30 cm.
The reaction tube was filled, heated to 300 ° C. while flowing nitrogen gas, and when the outflow of water was no longer observed, hydrogen fluoride was entrained in the nitrogen gas and its concentration was gradually increased. The hot spot due to the fluorination of the filled chromium-supported alumina reached the outlet end of the reaction tube, and the reactor temperature was adjusted to 45
The temperature was raised to 0 ° C., and the state was maintained for 1 hour to prepare a catalyst.

Example 1 Preparation Example 1 as a gas phase fluorination catalyst in a gas phase reactor (made of SUS316L, diameter 1 inch, length 30 cm) consisting of a cylindrical reaction tube equipped with an electric furnace.
150 ml of the catalyst prepared in the above was charged. About 155 ml /
While flowing nitrogen gas at a flow rate of 300
C., and hydrogen fluoride was entrained in nitrogen gas at a rate of about 0.25 g / min. The temperature of the reaction tube was raised to 350 ° C. and kept for 1 hour. Next, the temperature of the reaction tube was lowered to 300 ° C., hydrogen fluoride was supplied at a rate of 0.23 g / min,
1,1,1,3,3-Pentachloropropane was vaporized in advance and the supply to the reactor was started at a rate of 0.21 g / min.

After 1 hour from the start of the reaction, the reaction was stable. For 1 hour from that time, the produced gas flowing out of the reactor was blown into water to remove the acid gas, and 70 g of organic matter was removed with a dry ice-acetone trap. I collected it. The results of gas chromatography analysis of the obtained organic matter are shown in Table 1.

[0020]

[Table 1]

Example 2 Preparation Example 1 as a gas phase fluorination catalyst in a gas phase reactor (made of SUS316L, diameter 1 inch, length 30 cm) consisting of a cylindrical reaction tube equipped with an electric furnace.
150 ml of the catalyst prepared in the above was charged. About 155 ml /
While flowing nitrogen gas at a flow rate of 300
C., and hydrogen fluoride was entrained in nitrogen gas at a rate of about 0.25 g / min. The temperature of the reaction tube was raised to 450 ° C. and kept for 1 hour. Next, 0.23 g of hydrogen fluoride
/ 1,1,3,3-pentachloropropane was vaporized in advance and the supply was started at a rate of 0.21 g / min into the reactor.

After 1 hour from the start of the reaction, the reaction was stable. For 1 hour from that time, the produced gas flowing out of the reactor was blown into water to remove the acidic gas, and 67 g of organic matter was removed with a dry ice-acetone trap. I collected it. The results of gas chromatography analysis of the obtained organic matter are shown in Table 1.

[0023]

EFFECTS OF THE INVENTION The method for producing 1,1,1,3,3-pentafluoropropane of the present invention is 1,1,1,1 which is easily available.
Since 1,1,1,3,3-pentafluoropropane can be continuously produced from 3,3-pentachloropropane as a raw material, it is useful as an industrial production method.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yasuo Hibino 2805 Imafuku Nakadai, Kawagoe City, Saitama Central Glass Co., Ltd.

Claims (2)

[Claims] 1. The method according to claim 1, wherein 1, 1
A method for producing 1,1,1,3,3-pentafluoropropane, which comprises reacting 1,1,3,3-pentachloropropane with hydrogen fluoride. 2. The 1,1,1,3 according to claim 1, wherein the fluorination catalyst is a chromium-supported alumina catalyst.
Method for producing 3-pentafluoropropane.