JPH0873385A - Production of 1, 1, 1, 3, 3-pentafluoropropane - Google Patents

Abstract

PURPOSE: To readily obtain the subject compound which has been hard to industrially produce on an industrial scale by reacting difluoroethylene with dichorofluoromethane in the presence of a Lewis acid catalyst and then fluorinating the resultant product with hydrogen fluoride. CONSTITUTION: This method for producing 1,1,1,3,3-pentafluoropropane is to initially react 1,1-difluoroethylene (hereinafter referred to as 2F) with dichlorofluoromethane (hereinafter referred to as R21) in the presence of a Lewis acid catalyst (preferably BF3 , AlCl3 , etc.), provide 1,2,2- trihydrodichlorotrifluoropropane and then fluorinate the resultant compound with hydrogen fluoride. The addition reaction of the F2 with R21 is preferably carried out in the liquid phase at -10 to +100 deg.C under a slight pressure to 10kg/cm<2> (gauge pressure). The fluorinating reaction is preferably conducted in the liquid phase at 20-150 deg.C according to a continuous reactional method. Furthermore, SbF5 , NbCl5 , etc., are preferred as the fluorinating catalyst used for the fluorination in the liquid phase.

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 1,1,1,3,3-pentafluoropropane (hereinafter abbreviated as R245fa). R245fa is a hydrofluorocarbon (HFC) that is useful as a blowing agent and does not destroy the ozone layer.

[0002]

2. Description of the Related Art As a method for manufacturing R245fa,
(1) Method of hydrogenating 1,1,3,3,3-pentafluoro-1-pentene in the presence of a palladium catalyst (Izve
st.Akad.Nauk SSSR, Otdel.Khim.Nauk.1960,1412)
Or (2) 1,1,3,3,3-pentafluoro-2,
A method of reducing hydrogen 2,3-trichloropropane in the presence of a palladium catalyst (US Pat. No. 2,942,036) is known.

[0003]

In the methods (1) and (2), the raw materials used are very expensive, and it is difficult to obtain them industrially.

[0004]

The present invention is a method for producing R245fa which overcomes the drawbacks found in the conventional methods, and is 1,1-difluoroethylene (hereinafter referred to as 2F) which can be obtained at a low cost on an industrial scale. Abbreviated) and dichlorofluoromethane (hereinafter abbreviated as R21) are reacted in the presence of a Lewis acid catalyst to obtain 1,2,2-trihydrodichlorotrifluoropropane, which is fluorinated with hydrogen fluoride. Is a method of easily producing R245fa in high yield.

Prior to describing the present invention in detail, the main reaction formula in the present invention is shown in Chemical formula 1. The starting materials 2F and R21 for this reaction are industrially available at low cost.

[0006]

Embedded image

In the addition reaction for obtaining 1,2,2-trihydrodichlorotrifluoropropane (hereinafter simply referred to as "addition reaction"), 2F and R21 are selectively reacted with each other in the presence of a Lewis acid catalyst. , 2-Trihydrodichlorotrifluoropropane. Where 1,2,2-
Trihydrodichlorotrifluoropropane is R24
It means at least one selected from 3fa and R243fb. The production ratio of R243fa and R243fb varies depending on the catalyst used, but both isomers can be converted to R245fa by the fluorination reaction.

The reaction molar ratio of 2F to R21 is 0.
5 to 1.5 are preferable, and 1.0 to 1.1 are more preferable.
It is a range of degrees. The addition reaction employs a batch reaction or a continuous reaction in which the raw materials are continuously supplied to the reactor and the reaction product is continuously withdrawn from the reactor. Preferred is a continuous reaction. The addition reaction of R21 and 2F itself is known from JP-A-4-193841.

As the Lewis acid catalyst used in the addition reaction,
At least one selected from the group 13 elements of B, Al, Ga and In, the group iron elements of Fe, Ni and Co, the group 4 elements of Ti, Zr and Hf, the group 5 elements such as Nb and Ta, and Sb, Sn and W. Preference is given to halides or oxides of one element. Particularly preferably, 13
Group 4, 4 and 5 elements.

As the halide catalyst, B, Al, G
a, In, Fe, Ni, Co, Sb, Nb, Sn, T
halides of i, Zr, Hf, W, such as chlorinated compounds,
Fluorinated or chlorinated fluorinated are preferred.

Specifically, BF ₃ , AlCl ₃ , AlC
_{lF 2, GaCl 3, InCl 3} , FeCl 3, NiC
l ₂ , CoCl ₂ , SbF ₅ , SbCl ₂ F ₃ , NbC
l ₅ , SnCl ₂ , TiCl ₄ , TiCl ₂ F ₂ , Zr
Cl ₄ , ZrCl ₂ F ₂ , ZrClF ₃ , HfCl ₄ ,
HfClF ₃ , WCl ₆ , TaCl _{5 and the} like are preferred.

As the halogenated oxide catalyst, an oxide of only one of the above elements or a composite oxide of two or more of the above elements is used as a suitable halogenating agent such as trichlorofluoromethane (hereinafter abbreviated as R11) or dichloro. Difluoromethane (hereinafter abbreviated as R12), 1,1,2-trichloro-
Chlorofluorocarbons such as 1,2,2-trifluoroethane, hydrochlorofluorocarbons such as R21 and chlorodifluoromethane, or chlorine, hydrogen fluoride,
It is preferable to use the one prepared by treating with fluorine or the like.

The halide or halogenated oxide catalysts of the above elements include elements other than the above, such as Si, Zn,
At least one kind of Mg, Cr, Cu, V, Bi, Mo and the like may be contained. In this case, these S
Elements such as i, Zn, Mg, Cr, Cu, V, Bi and Mo are generally contained in the state of halide or halogenated oxide.

The conditions for preparing the halogenated oxide catalyst vary depending on the oxide used and the halogenating agent, but an excess amount of halogenating agent is usually used with respect to the oxide.

The temperature for preparing the halogenated oxide catalyst is usually 100 to 500 ° C., preferably 200 to 450 ° C. when the catalyst is prepared in the gas phase. When the catalyst is prepared in the liquid phase, it is usually 0 to 200 ° C., preferably 20 to 120 ° C.
℃

The amount of the Lewis acid catalyst present in the addition reaction is 100 parts by weight of the total amount of the raw materials (2F and R21) in the reactor in the batch reaction, whereas the amount of the raw materials (2F and R21) staying in the reactor in the continuous reaction is 100 parts by weight. 0.01 to 50 parts by weight, preferably 0.1 to 50 parts by weight, based on 100 parts by weight in total.
It is set to 10 parts by weight.

The reaction temperature of the addition reaction is usually from -40 to +.
The temperature is 200 ° C, preferably -10 to + 100 ° C. The reaction pressure of the addition reaction is not particularly limited, and normal pressure does not cause any problem, but slight pressure to 10 kg / cm ² (gauge pressure) is preferable.

The addition reaction may be a gas phase reaction or a liquid phase reaction. A liquid phase reaction with less side reaction products is preferable. The reaction is perfluorooctane or perfluoro (2
-Butyltetrahydrofuran) may be used in an inert solvent. In order to facilitate purification, it is usually preferable to use no solvent other than the reaction raw materials and reaction products.

1,2,2-trihydrodichlorotrifluoropropane is fluorinated with hydrogen fluoride to obtain the target R
The fluorination reaction for obtaining 245fa (hereinafter, simply referred to as fluorination reaction) may be a liquid phase reaction or a gas phase reaction. A liquid phase reaction with less side reaction products is preferable. The fluorination reaction employs a batch reaction or a continuous reaction in which the raw materials are continuously supplied to the reactor and the reaction product is continuously withdrawn from the reactor. Preferred is a continuous reaction.

The starting material 1,2,2-trihydrodichlorotrifluoropropane is R243f obtained by addition reaction.
The reaction product containing a and R243fb may be directly subjected to the fluorination reaction, and R2 separated from the reaction product may be used.
A mixture of only 43fa and R243fb may be subjected to the fluorination reaction. In addition, R243 separated from the reaction product
fa and R243fb may be subjected to separate fluorination reactions.

Since R243fa has a higher reactivity with hydrogen fluoride than R243fb, R used for the fluorination reaction
The mixture of 243fa and R243fb preferably has a high mixing ratio of R243fa. Also, R243fa and R
Only R243fa separated from the mixture of 243fb may be subjected to the fluorination reaction.

As the fluorination catalyst used in the liquid phase fluorination with hydrogen fluoride, a halide of at least one element selected from Sb, Nb, Ta and Sn, for example, a chloride, a fluoride or a fluorinated fluoride is used. preferable. Specifically, SbF ₅ , SbCl ₅ , SbCl ₂ F
₃ , NbCl ₅ , NbClF ₄ , NbF ₅ , TaF ₅ ,
TaCl ₅ , TaClF ₄ , SnCl ₄ , SnClF ₃
Are preferred.

The abundance of the fluorination catalyst is such that, in the batch reaction, 100 parts by weight of 1,2,2-trihydrodichlorotrifluoropropane as the raw material in the reactor, and in the continuous reaction, the raw material staying in the reactor. 1,2,2-trihydrodichlorotrifluoropropane of 100 parts by weight,
Usually, 0.01 to 50 parts by weight, preferably 0.1 to 10
It is considered to be part by weight.

The liquid phase fluorination reaction is carried out under normal pressure or under pressure.
It is preferably carried out in a temperature range of 0 to 200 ° C, particularly 20 to 150 ° C. The reaction may be performed using a reaction solvent other than the reaction raw material and the reaction product. The solvent used in this case is not particularly limited as long as it dissolves the raw material and the solvent itself is less likely to be fluorinated than the raw material. Examples of such a solvent include hydrofluorocarbons other than R245fa, perfluorocarbons such as perfluorooctane, and perfluoropolyethers.

The supply molar ratio of hydrogen fluoride to 1,2,2-trihydrodichlorotrifluoropropane (the stoichiometric ratio is 2) is not particularly limited as long as it is 2 or more. Considering the efficiency of the reaction vessel and the loss due to the recovery of hydrogen fluoride, the range of 2 to 20, particularly 2 to 10 is preferable.
Hydrogen fluoride may be charged in advance before the reaction, or may be blown into the liquid phase during the reaction. In particular, a method of blowing into the liquid phase during the reaction is preferable.

Usually, the reaction pressure is set to 0 to 20 kg / cm ² (gauge pressure), and when a reaction solvent other than the reaction raw material and the reaction product is used, it varies depending on the kind of the solvent.

[0027]

【Example】

[Preparation Example 1] 1000 g of commercially available γ-alumina was dried to remove water, and then 1 in a R12 / nitrogen mixed gas stream.
Chlorine fluorination was carried out at 00 to 300 ° C to obtain a halogenated oxide catalyst.

[Preparation Example 2] 1000 g of zirconium oxide prepared from an aqueous solution of zirconium nitrate and aqueous ammonia and baked was dried to remove water, and then R12 /
Chlorination and fluorination were performed at 150 to 400 ° C. in a nitrogen mixed gas stream to obtain a halogenated oxide catalyst.

[Preparation Example 3] 1000 g of titanium oxide prepared from an aqueous solution of titanium tetrachloride and ammonia and calcined.
Was dried to remove water, and then chlorinated and fluorinated at 100 to 400 ° C. in an R11 / nitrogen mixed gas stream to obtain a halogenated oxide catalyst.

Example 1 20 g of AlCl ₃ was added to a 2 liter Hastelloy C autoclave, degassed under reduced pressure, and 1200 g (11.65 mol) of R21 was added.
2F was continuously added while keeping the autoclave at -20 ° C. After adding 760 g (11.88 mol) of 2F, the stirring was continued for an additional 1 hour, and the reaction solution was filtered to obtain a crude reaction solution 1920
g was recovered. Table 1 shows the results of analysis of the composition of the recovered reaction crude liquid (unit: mol%, the same in other Examples) using a gas chromatograph and ¹⁹ F-NMR.

The reaction crude liquid was distilled to obtain 1680 g of a mixture of R243fa and R243fb. Next, in a reactor equipped with a 0 ° C. cooling pipe in a 5 liter Hastelloy C autoclave, the R243fa and R243fb were placed.
A mixture of 1680 g (10.06 mol) and SbCl ₅ 2
0 g and hydrogen fluoride 600 g (30 mol) were charged, and after degassing, the reaction was carried out at a reaction temperature of 80 ° C.

While the HCl by-produced by the reaction was purged through a 0 ° C. cooling pipe, the internal pressure of the reactor was adjusted to 10 kg / c.
After reacting for 10 hours while maintaining m ² (gauge pressure),
The total amount (131
0 g) was recovered. Table 2 shows the results of analysis of the composition of the recovered reaction crude liquid (unit: mol%, the same in other examples) using a gas chromatograph and ¹⁹ F-NMR.

[Example 2] R in the same manner as in Example 1 except that 20 g of ZrCl ₄ was used instead of 20 g of AlCl _3.
21 and 2F are reacted, the reaction solution is filtered and the reaction crude solution 1
912 g was recovered. Table 1 shows the results of analysis of the composition of this crude reaction liquid in the same manner as in Example 1.

The reaction crude liquid was distilled to obtain 1750 g of a mixture of R243fa and R243fb. This R243
The fluorination reaction was performed in the same manner as in Example 1 except that 1750 g of a mixture of fa and R243fb was used, and the reaction crude liquid 13
20 g was obtained. The composition of this reaction crude liquid was analyzed in the same manner as in Example 1, and the results are shown in Table 2.

[Examples 3 to 5] R21 and 2F were reacted in the same manner as in Example 1 except that 20 g of each of the catalysts prepared in Preparation Examples 1 to 3 was used. The composition of the reaction crude liquid obtained by separating the reaction liquid by filtration was analyzed in the same manner as in Example 1, and the results are shown in Table 1. This reaction crude liquid was subjected to a fluorination reaction in the same manner as in Example 1 using 20 g of each of the catalysts shown in Table 2 without distillation. The composition of the obtained reaction crude liquid was analyzed in the same manner as in Example 1, and the results are shown in Table 2.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

INDUSTRIAL APPLICABILITY As shown in the examples, the present invention has an effect that R245fa, which has been difficult to produce on an industrial scale, can be easily produced in a high yield.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B01J 27/132 X 27/135 X C07C 17/20 17/278 19/10 // C07B 61/00 300 (72) Inventor Keiichi Onishi 1160 Matsubara, Hazawa-machi, Kanagawa-ku, Kanagawa Prefecture A-G Technology Co., Ltd. (72) Shin Tatematsu 1160 Matsubara, Hazawa-machi, Kanagawa-ku, Yokohama Kanagawa Prefecture・ In Technology Co., Ltd.

Claims (5)

[Claims] 1. 1,1-Difluoroethylene and dichlorofluoromethane are reacted in the presence of a Lewis acid catalyst to obtain 1,2,2-trihydrodichlorotrifluoropropane, which is fluorinated with hydrogen fluoride. A method for producing 1,1,1,3,3-pentafluoropropane. 2. A Lewis acid catalyst is B, Al, Ga, In,
Fe, Ni, Co, Sb, Nb, Sn, Ti, Zr, H
The method according to claim 1, which is a halide or a halogenated oxide of at least one element selected from f, W and Ta. 3. A method for producing 1,1,1,3,3-pentafluoropropane, which comprises fluorinating 1,2,2-trihydrodichlorotrifluoropropane with hydrogen fluoride. 4. The method according to claim 1, 2 or 3, wherein the fluorination is carried out in the presence of a fluorination catalyst composed of a halide of at least one element selected from Sb, Nb, Ta and Sn. 5. 1,2,2-Trihydrodichlorotrifluoropropane is 1,1-dichloro-3,3,3-trifluoropropane and 1,3-dichloro-1,1,3-
The method according to claim 1, wherein the production method is at least one selected from trifluoropropane.