JP2864037B2 - Method for producing antimony pentafluoride - Google Patents

Description

The present invention relates to an improved method for producing antimony pentafluoride.

[Conventional technology and its problems]

Antimony pentafluoride is a useful substance as a super-acid catalyst, fluorinating agent (particularly halogen exchange of organic chlorine compounds), and a strong oxidizing agent. It reacts with antimony pentachloride and a large excess of hydrofluoric anhydride. Or by the reaction of metallic antimony or antimony trioxide with fluorine gas. In the former method using hydrofluoric anhydride,
Antimony pentachloride is not completely converted to antimony pentafluoride, and various stable intermediate compounds (SbCl ₃ F ₂ , SbCl ₂ F
₃ )) and the purity of the product is low. The progress of the reaction is slow, requiring several days to one week or more. When the metallic antimony in the method according to the latter fluorine gas as a starting material, once generated antimony pentafluoride is redox reaction with the metal antimony unreacted, generated by double salt such as SbF ₅ · 2SbF _3. These are solid high-melting substances at the reaction temperature,
Not readily converted to the F ₅ alone. Therefore, when these substances are formed on the surface of antimony, the fluorination reaction does not proceed and the yield of antimony pentafluoride decreases. Also, the three case of antimony oxide as a raw material, the free oxygen and fluorine to produce the reaction was very toxic OF _2.

[Knowledge related to problem solving]

The present inventors, in the production of antimony pentafluoride,
We sought to find a way to suppress the formation of intermediate compounds that hinder the reaction and avoid the generation of harmful substances associated with side reactions. As a result, they have found that, in the reaction between granular metal antimony and fluorine gas, when HF gas is added to fluorine gas, antimony pentafluoride can be obtained without producing an intermediate compound that hinders the fluorination reaction.

[Configuration of the invention]

The present invention pentafluoride which comprises condensing collecting antimony pentafluoride vapor containing HF to the F ₂ gas containing metallic antimony particles and HF gas is reacted at 0.99 ° C. to 300 ° C., to produce at 50 ° C. or less Provided is a method for producing antimony halide.

It is important to select the size of metal antimony as a raw material. The particle size is preferably from 0.1 mm to 5 mm. If the thickness is less than 0.1 mm, the reaction with the F ₂ gas may occur rapidly, so the reaction gas needs to be diluted with an inert gas. If it exceeds 5 mm, on the contrary, the efficiency of the reaction with F ₂ gas decreases.

The amount of HF added to the F ₂ gas may be 1 vol% or more.
The addition of HF to F ₂ gas promotes the fluorination of antimony,
Inhibiting the production of SbF ₅ · 2SbF _3. Although the reason is not clear, it is known that when a small amount of HF is mixed into antimony pentafluoride, the vapor pressure increases, and there is an effect that antimony pentafluoride is easily evaporated and released. Addition amount
If it is less than 1 vol%, the concentration of antimony pentafluoride released into the gas phase without the progress of fluorination of antimony is extremely low.
When HF is added in an amount of 30 vol% or more, the content of accompanying HF in the generated antimony pentafluoride increases, and the purity of antimony pentafluoride obtained by condensation decreases. The addition of HF can be performed according to a usual method.

The reaction temperature of the fluorination is in the range of 150 ° C to 300 ° C. If the temperature is lower than 150 ° C., the fluorination reaction does not proceed. On the other hand, if the temperature exceeds 300 ° C, antimony trifluoride (melting point 292 ° C)
Is melted and vaporized, so it is unavoidable to mix it into the generated antimony pentafluoride (boiling point: 142.7 ° C) gas.
Double salt formation of ₅ · 2SbF ₃ progresses.

The reaction time of the fluorination reaction is determined according to the reaction temperature, gas flow rate, and the like. The produced antimony pentafluoride is condensed and recovered. The lower the condensation temperature, the higher the recovery of antimony pentafluoride, but it is preferably 0 ° C. or lower. HF contained in antimony pentafluoride can be easily removed by distillation, but the condensation temperature is preferably −40 ° C. or higher because the HF condensation increases as the condensation temperature decreases.

[Specific Disclosure of the Invention] Hereinafter, the present invention and its effects will be specifically described with reference to Examples and Comparative Examples. Reaction conditions and results are further summarized in Table 1.

Example 1 An aluminum boat containing 50.3 g of antimony metal having a particle size of 0.1 to 5 mm and a purity of 99.75% and having a purity of 99.75% was charged into an aluminum reaction tube (inner diameter: 70 mm, length: 640 mm). After the inside of the reaction tube was sufficiently replaced, an F ₂ gas containing 25 vol% of HF was ventilated while maintaining the temperature of the reaction tube at 250 ° C., and the gas containing the reaction product was maintained at 40 ° C. in a quartz flask. The reaction product was condensed and collected by distillation, and after removal of HF by distillation, the reaction product was a colorless viscous substance (83.5 g) which was a liquid at room temperature.F / Sb molar ratio Was 4.8.

Example 2 By the same operation as in Example 1, containing 2 vol% HF
200.3 g of metal antimony (purity 99.75%) having a particle size of 0.1 to 5 mm was fluorinated with F ₂ gas at a temperature of 250 ° C., and the reaction product was condensed and collected at a temperature of −20 ° C. The reaction product after the distillation was 350.2 g of a colorless viscous substance which was a liquid at room temperature. (F / S
b) The molar ratio was 4.8.

Example 3 By the same operation as in Example 1, 200.7 g of metal antimony (purity: 99.75%) having a particle size of 0.1 to 5 mm was fluorinated at a temperature of 250 ° C. with F ₂ gas containing 10 vol% of HF to form a reaction product. The material was condensed and collected at a temperature of -30 ° C. The reaction product after the distillation was 353.1 g of a colorless viscous substance which was a liquid at ordinary temperature.
(F / Sb) molar ratio was 4.9.

300 ° C. EXAMPLE 4-6 Reaction temperature, 200 ° C., except made in 170 ° C., to obtain a SbF ₅ under the same conditions as in Example 3. Table 1 shows the results.

Comparative Example 1 By the same operation as in Example 1, about 60 g of metal antimony (purity: 99.75%) having a particle size of 0.1 to 5 mm was fluorinated at a temperature of 250 ° C. with F ₂ gas containing 0.2 vol% of HF at a temperature of 250 ° C. Condensed and collected at a temperature of 20 ° C. The reaction product was a white solid at room temperature, the (F / Sb) molar ratio was 2.7, and the yield was 1.6 g.

Comparative Examples 2 and 3 Fluorination was performed under the same conditions as in Example 3 except that the reaction temperatures were 350 ° C. and 150 ° C., respectively. The reaction product in Comparative Example 2 was a white solid at room temperature, the F / Sb molar ratio was 3.4, and the amount produced was 29.7 g. At a reaction temperature of 150 ° C., no reaction occurred.

In this way, metal antimony can be fluorinated with an F ₂ gas containing less than 1 vol% of HF, or a gas of the same composition can be used
When fluorinated at a temperature exceeding 350 ° C., the fluorination of antimony metal was insufficient, and the production of SbF ₅ did not proceed, and the main component of the reaction product was SbF ₃ .

The same procedure as in Reference Example 1 Example 1 was fluorinated by heating in size in the F ₂ gas containing 10 vol% of HF is the 151.3g of metallic antimony 0.02 to 0.1 mm (purity 99.75%) from 142 ° C. , −
As a result of condensation and collection at a temperature of 20 ° C, the temperature of the reaction tube suddenly increased.
The temperature rose to 350 ° C and the reaction ran away.

The (F / Sb) molar ratio of the obtained reaction product was 4.3,
bF ₃ was mixed.

According to the method of the present invention, antimony pentafluoride can be efficiently obtained at a high yield. Further, in the method of the present invention, since the reaction proceeds gently and no toxic substance is generated,
Antimony pentafluoride can be produced safely and on a large scale.

Continued on the front page (72) Inventor Akihiro Nakama 1-297 Kitabukuro-cho, Omiya-shi, Saitama In the Chemical Products Development Center, Mitsui Kinzoku Co., Ltd. No. Within Tochem Products Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) C01G 30/00

Claims (4)

(57) [Claims] 1. An antimony metal particle and an F ₂ gas containing HF are mixed with
A method for producing antimony pentafluoride, comprising reacting at 0 ° C. to 300 ° C. and condensing antimony pentafluoride vapor containing HF at 50 ° C. or less. 2. The method according to claim 1, wherein the condensation temperature is 0 ° C. or less. 3. The method according to claim 1, wherein the particle size of the metal antimony is 0.1 mm to 5 mm. 4. The content of HF contained in F ₂ gas is 1 to 30 vol%.
The method according to any one of claims 1 to 3, wherein