JPH044981B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] Antimonic acid hexafluoride and antimonate hexafluoride are currently used as non-aqueous electrolytes for batteries and polymerization catalysts for organic compounds, and their use will continue to increase in the future. I think that the. The present invention relates to this manufacturing method.

[Problems to be solved by conventional technology and invention]

Generally known methods for producing antimony hexafluoride hydrochloric acid include a method in which an alkali carbonate and antimony pentafluoride are dissolved in hydrofluoric acid, and a method in which a mixture of an alkali carbonate and antimony trioxide is reacted with bromine trifluoride. ing. The production of antimony pentafluoride and bromine trifluoride requires expensive and extremely dangerous fluorine gas, so methods using these compounds as raw materials lack economic efficiency and safety, and are not suitable for industrial use. It's hard to call it a method. Also, JP-A-51-
Publication No. 129891, "Method for producing fluorine-containing condensed acid alkali," discloses a method for producing hexafluorinated antimonic acid salt by adding an alkali fluoride to hexafluorinated antimonic acid. The method for producing hexafluorinated antimonic acid is not clear. The use of pentavalent antimony compounds such as antimony pentafluoride, antimony pentachloride, and antimony pentoxide can be considered as raw materials for producing antimony hexafluoride, but antimony pentafluoride is produced and processed as described above. Antimony pentachloride is not easy to handle and is the most common raw material for pentavalent antimony, but Cl ^- cannot be avoided in an aqueous solution of antimony hexafluoride. It is extremely difficult to produce hexafluorinated antimonic acid, as it does not dissolve easily.

[Means and actions for solving problems]

Therefore, the present inventors conducted extensive research to establish industrial production of hexafluoroantimonic acid and its salts, and found that antimony trioxide, which is the most common raw material for antimony and has good reactivity with hydrofluoric acid. We have devised a method for producing hexafluorinated antimonic acid or its salts using as a raw material.

That is, by dissolving antimony trioxide in hydrofluoric acid and adding an aqueous hydrogen peroxide solution to the solution, trivalent antimony becomes pentavalent antimony under extremely mild conditions, and easily becomes antimony hexafluoride. It was discovered that an acid can be obtained. Further, any one of a fluoride salt, an acid fluoride salt, a carbonate, a hydroxide, etc. is added to the mixed solution in advance. Alternatively, by using alkali peroxide instead of an aqueous hydrogen peroxide solution, antimony hexafluoride hydrochloride can be produced in a form that does not contain the hydroxy compound [M ⁺ SbF _6-o (OH) ^- _o ], which is a hydrolysis product. We also found that it can be obtained by

The order in which the above-mentioned salts and the like and antimony trioxide are added does not affect the synthesis of antimonate hexafluoride. Regarding the above-mentioned salts, it is preferable to use an acidic fluoride salt, which requires less water if the compound has a high solubility in order to extract the antimonate hexafluoride in the form of crystals. Furthermore, when added to hydrofluoric acid, acidic fluoride salts have the advantage of generating less heat than other salts and compounds. The hydrofluoric acid used is usually 80% or less, preferably 40 to 70%. If the concentration is too high, increase the reaction temperature to 40℃
Since it is necessary to maintain the temperature above, the vaporization and scattering of hydrogen fluoride becomes large. On the other hand, if the concentration is too low, the yield will decrease due to solubility.

The reaction temperature is arbitrary up to 0°C or higher and the boiling point of the solution, but is preferably 40°C or higher and 70°C or lower. If the reaction temperature is less than 40℃, the oxidation reaction of hydrogen peroxide will be poor, and when the hydrogen peroxide concentration in the reaction solution increases, the reaction will occur rapidly and the temperature in the reaction solution will rise rapidly, and in the worst case, the reaction will not occur. There is a risk of liquid bumping. If the reaction temperature is too high, hydrogen fluoride and vaporized scattering will increase, making it difficult to maintain the composition of the reaction solution. Hydrogen peroxide may be added in an amount of from an equivalent to more than an equivalent to trivalent antimony, but preferably from an equivalent to 1.05 equivalents or less. If more than 1.05 equivalents are added, excess hydrogen peroxide will remain in the aqueous hexafluorinated antimonic acid solution, which may be undesirable depending on the use of the synthesized acid. If the amount is less than the equivalent amount, trivalent antimony will remain and the quality will deteriorate.

Hydrogen fluoride is used in an amount equal to or more than the amount of antimony raw material. This is because when hexafluorinated antimonate is extracted as crystals, a hydroxyl compound with an OH group crystallizes if hydrogen fluoride is insufficient. Therefore, in order to prevent this crystallization, hydrogen fluoride is added in excess.

Fluoride salts, acidic fluoride salts, carbonates, and hydroxides should be used in equivalent or less amounts relative to antimony. If the amount exceeds the equivalent amount, the fluoride salt and the acidic fluoride salt will be mixed into the antimonate hexafluoride, resulting in a decrease in quality.

〔Example〕

Examples of the invention are as follows.

Example 1 445g of 70% hydrofluoric acid and 292g of antimony trioxide
After stirring for 1 hour, the Teflon beaker containing the above reaction solution was placed in a 40°C water bath, and 114 g of a 60% aqueous hydrogen peroxide solution was added dropwise over about 7 hours while stirring. During this time, the temperature of the reaction solution was increased to 50-60℃.
Adjust the dropwise addition of the hydrogen peroxide solution to maintain the temperature at °C. After completing the dropwise addition of the aqueous hydrogen peroxide solution, the mixture was cooled to room temperature to obtain 750 g of a synthetic solution. When an equivalent amount of acidic sodium fluoride was added to this synthetic solution, sodium hexafluoride antimonate crystallized as powder
Confirmed by line circuit analysis. The results of chemical analysis of this synthetic solution were 32.3% Sb ⁵⁺ , no Sb ³⁺ , and 31.0% F.
This corresponds to about 62.8% hexafluoroantimonic acid aqueous solution.

Example 2 229g of 70% hydrofluoric acid and 146g of antimony trioxide
g and 78 g of acidic potassium fluoride were added, and after stirring for 1 hour, the Teflon beaker containing the above reaction solution was placed in a 40°C water bath, and 57 g of 60% hydrogen peroxide aqueous solution was added dropwise over about 6 hours while stirring. do.
During this time, the dropwise addition of the hydrogen peroxide solution is controlled so as to maintain the reaction temperature at 40 to 50°C. After completing the addition of the hydrogen peroxide solution, stir in a water bath for 30 minutes. Thereafter, the beaker was transferred to a cold water bath, the temperature of the synthesis solution was cooled to 18°C, and the crystals were filtered off and dried at 105°C to obtain 221 g of crystals.

Powder X-ray diffraction analysis confirmed that the crystals were potassium hexafluoroantimonate. The results of chemical analysis are Sb ⁵⁺ 43.8%, F41.4% (theoretical value Sb ⁵⁺ 44.30
%, F41.47%).

Example 3 114 g of acidic ammonium fluoride and 357 g of antimony trifluoride were added to 320 g of 50% hydrofluoric acid and stirred. A Teflon beaker containing the above reaction solution was placed in a 40°C water bath, and 113 g of a 60% aqueous hydrogen peroxide solution was added dropwise over 7 hours while stirring.
During this time, the dropwise addition of the aqueous peroxide solution is adjusted so as to maintain the temperature of the reaction solution at 50 to 55°C. After completing the addition of the hydrogen peroxide aqueous solution, stir in a water bath for 30 minutes.
Then transfer the beaker to a cold water bath and bring the temperature of the synthetic solution to 16
The mixture was cooled to 0.degree. C., and the crystals were filtered off and dried at 105.degree. C. to obtain 250 g of crystals. Powder X-ray diffraction analysis confirmed that the crystals were ammonium hexafluoride antimonate. Chemical analysis results are Sb ⁵⁺ 47.5%, F44.7%
(Theoretical value Sb ⁵⁺ 47.98%, F44.92%).

Example 4 89 g of antimony trifluoride was added to 100 g of 50% hydrofluoric acid and stirred. A Teflon beaker containing the above reaction solution was placed in a 40°C water bath, and 19.5 g of sodium peroxide was added over 7 hours while stirring.
Add 14g of 60% hydrogen peroxide solution. During this time, the addition of sodium peroxide and hydrogen peroxide aqueous solution is adjusted so as to maintain the reaction temperature at 50 to 60°C. After adding the sodium peroxide and hydrogen peroxide aqueous solutions, stir in a water bath for 30 minutes. Thereafter, the beaker was transferred to a cold water bath, the temperature of the synthesis solution was cooled to 18°C, and the crystals were filtered off and dried at 105°C to obtain 58 g of crystals.

Powder X-ray diffraction confirmed that the crystals were sodium hexafluoride antimonate. The chemical analysis results are Sb ⁵⁺ 46.2%, F4 3.72% (theoretical value Sb ⁵⁺ 47.06%,
F44.06%).

〔Effect of the invention〕

The synthesis method of the present invention is excellent in all aspects such as economy and safety, and can be fully utilized industrially.

Claims (1)

[Claims] 1. A mixture of hydrofluoric acid and a trivalent antimony compound, or a mixture of a fluoride salt, an acidic fluoride salt, a carbonate, or a hydroxide. A method for synthesizing hexafluorinated antimonic acid and hexafluorinated antimonate, which comprises adding an aqueous hydrogen peroxide solution or an alkali peroxide to oxidize trivalent antimony to pentavalent antimony. 2. The fluoride salt, acidic fluoride salt, and carbonate described in claim 1 are alkali metal salts and ammonium salts, and the hydroxide is alkali metal hydroxide and aqueous ammonia. Alkali oxide is a method for synthesizing hexafluoroantimonic acid and hexafluoroantimonate, which are sodium peroxide and potassium peroxide.