JPS647005B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing high purity metal hydroxides or oxides. More specifically, the present invention relates to a method for producing high-purity metal hydroxides or oxides from organometallic compounds. The high purity metal hydroxide or oxide will be described below using aluminum oxide as a representative. however,
It is clear that the invention is not limited thereto. It is well known that aluminum hydroxide or aluminum oxide can be produced by oxidizing or hydrolyzing an organoaluminum compound such as an alkyl aluminum compound or an alkoxy aluminum compound. However, ordinary organoaluminum compounds contain trace amounts of titanium, vanadium, chromium, manganese,
Elements or metal compounds (hereinafter referred to as impurities) such as iron, cobalt, nickel, copper, uranium, and silicon are present. Impurities in this organoaluminum compound may be extracted from the aluminum raw material for the synthesis of the organoaluminum compound, extracted from the reactor material, or added to additives to accelerate the reaction during the synthesis reaction of the organoaluminum compound. Therefore, it exists. The presence of impurities in organoaluminum compounds is
When producing aluminum hydroxide or alumina by hydrolyzing an organoaluminum compound, there is a disadvantage that high purity aluminum hydroxide or alumina cannot be produced. When producing aluminum hydroxide or aluminum oxide from an organoaluminum compound, it is easy to think of a method in which the above-mentioned impurities in the raw organoaluminum compound are removed by a method such as precision distillation, and then oxidized or hydrolyzed. In such cases, it is essentially difficult to purify and recover products that require purity of three nines or more. This is because the impurities present in the organoaluminum compound are organometallic compounds having the same organic groups as the organoaluminum compound, and their boiling point ranges are similar, so they cannot be effectively separated. Under such circumstances, the present inventors conducted intensive research to find an industrial method for producing highly pure metal hydroxides or metal oxides from organometallic compounds, and as a result, they found that the above-mentioned impurities We discovered an unexpected behavior in which impurities in the organometallic compound are concentrated into the reaction product when the organometallic compound containing the compound is first hydrolyzed under specific conditions and then distilled. The invention was completed. It is an object of the present invention to provide a new process for obtaining metal hydroxides or oxides that are substantially to completely free of impurities. That is, the present invention deals with general formulas in a liquid state.

[Formula] or

[Formula] (In the formula, M ₃ is a trivalent element selected from Al or Y,
M ₄ is a tetravalent element selected from Si, Ti or Zr, R ₁ ,
R ₂ , R ₃ and R ₄ are the same or different alkyl, alkoxy or hydrogen atoms) is stirred under stirring conditions.
pre-hydrolyzing 0.1 to 50% to produce a solid reaction product, distilling the pre-reaction product, distilling and separating the solid reaction product and unreacted organometallic compound to recover the organometallic compound; The present invention provides a method for producing a high-purity metal hydroxide or oxide by subjecting the recovered organometallic compound to main hydrolysis. The raw organometallic compound used in the production of metal hydroxides or oxides according to the method of the present invention is an organometallic compound containing at least one metal impurity other than the metal forming the mother liquor. Such impurities include at least one metal or metal compound other than the metal forming the mother liquor, such as titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, aluminum, gallium, or uranium.
It exhibits a remarkable effect on the removal of these impurities from seed-containing organometallic compounds. Although the concentration of impurities in the organometallic compound is not a limiting factor in the purification process according to the method of the present invention, it is usually possible to use a starting material organometallic compound with an impurity concentration of about 0.5% by weight or less to an extremely high impurity concentration of about 0.01% by weight or less. Purity organometallic compounds can be obtained. As a raw material organometallic compound, the general formula

【formula】 or

[Formula] (In the formula, M ₃ is a trivalent element selected from Al or Y,
M ₄ is a tetravalent element selected from Si, Ti or Zr, R ₁ ,
R ₂ , R ₃ and R ₄ are the same or different alkyl, alkoxy or hydrogen atoms). Preferably, an organometallic compound having an alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 8 carbon atoms of a metal element such as Al, Si, Zr, or Sn is treated. Especially triethylaluminum, tripropylaluminum, tributylaluminum, trihexylaluminum, dibutylaluminum hydride, dihexylaluminum hydride,
Dioctylaluminium hydride, triethoxyaluminum, tripropoxyaluminum, tributoxyaluminum, and triamyloxyaluminum are preferably used. Further, in the purification treatment of the method of the present invention, the impurity-containing organometallic compound can be subjected to the purification treatment alone, but it is also possible to use it as a mixture with an organic solvent. Such organic solvents include pentane, hexane,
Saturated aliphatic hydrocarbons such as octane, decane, dodecane, paraffin oil, and kerosene; unsaturated aliphatic hydrocarbons such as pentene, hexene, heptene, octene, decene, and dodecene; alicyclic hydrocarbons such as cyclohexane and cyclopentane; Aromatic hydrocarbons such as benzene and toluene, alcohols such as methanol, ethanol, propanol and butanol, and ethers such as diethyl ether, dipropyl ether, anisole, dioxane and tetrahydrofuran can be used. In the method of the present invention, about 0.1 to 50% of the organometallic compound containing impurities as described above is hydrolyzed under stirring conditions while the organometallic compound is kept in a liquid state. It is essential that this reaction be carried out under stirring conditions while keeping the organometallic compound in a liquid state. Stirring conditions can be easily determined through preliminary experiments.
Usually, it is sufficient to rotate the stirring blade at 10 to 200 rpm. When the above reaction is kept in a liquid state and carried out under stirring conditions, a reaction of impurities occurs at the same time as the reaction of the organometallic compound. After carrying out the reaction, the unreacted organometallic compound is essentially to completely free of impurities, and the impurities become present in the solid reaction product. However, even if the mixture is kept in a liquid state, impurities cannot be substantially removed unless it is stirred because local reactions occur. Water, steam, acidic aqueous solution, etc. are usually used as the reactant. It is desirable to supply water, acidic aqueous solution, etc. in a diluted state with an organic solvent, but it is of course possible to supply them as they are. In the preliminary reaction of the present invention, the amount of the reactant used is generally about 0.1 to 0.1 to
An amount is used in which 50%, preferably about 1 to 20%, is oxidized or hydrolyzed. When the reaction ratio of the organometallic compound is less than 0.1%, the removal rate of impurities decreases, while when it is more than 50%, the removal rate is good but it becomes uneconomical, which is not preferable. Preliminary reaction conditions may be carried out at a temperature of about 0 to 150°C. Further, any method of contacting the impurity-containing organometallic compound and the reactant may be used, but a method in which the reactant is added to a state where the organometallic compound is stirred is usually suitably applied. The pre-reacted organometallic compound may be subjected to a distillation treatment as it is or after separation of reaction products by standing, filtration, centrifugation, etc. as necessary. In carrying out the method of the present invention, the organometallic compound pre-reacted as described above is subjected to distillation treatments such as simple distillation, precision distillation, and vacuum distillation. The distillation method may be appropriately selected depending on the purity of the target organometallic compound, and the distillation temperature may also be determined depending on the physical properties of the organometallic compound to be purified. Generally, distillation treatment is carried out under a reduced pressure of 0.1 to 100 mmHg at 50
It is desirable to use a temperature range of ~250°C. Distillation treatment is therefore an essential step in the purification method of the present invention, and impurities cannot be effectively removed unless such distillation treatment is performed. In implementing the method of the present invention, the organometallic compound purified as described above is then subjected to the main hydrolysis reaction (hereinafter referred to as the main reaction). This reaction may be carried out by keeping the purified organometallic compound in a liquid state and bringing it into contact with the reactant with or without stirring, but it is preferable to carry out the reaction with stirring. The reactant is usually water, steam, acidic aqueous solution,
Oxygen, air, etc. can be used. Although water, acidic aqueous solution, etc. are preferably supplied in a diluted state with the organic solvent, they can also be supplied as they are. Although the amount of the reactant to be used is arbitrary, it is generally sufficient to use a substantially stoichiometric amount or more of the reactant. The reaction is generally carried out at a temperature range of about 0-150°C. The organometallic compound purified in carrying out this reaction can be subjected to the reaction alone or as a mixture with an organic solvent. Examples of such organic solvents include saturated aliphatic hydrocarbons such as pentane, hexane, octane, decane, dodecane, paraffin oil, and kerosene, unsaturated aliphatic hydrocarbons such as pentene, hexene, heptene, octene, decene, and dodecene, and cyclohexane. , alicyclic hydrocarbons such as cyclopentane, aromatic hydrocarbons such as benzene and toluene, alcohols such as methanol, ethanol, propanol and butanol, ethers such as diethyl ether, dipropyl ether, anisole, dioxane, and tetrahydrofuran, etc. can be used. In carrying out the method of the present invention, the reactants reacted as described above are subjected to over-separation, sedimentation, centrifugation,
The metal hydroxide or metal oxide is separated by known means such as evaporation. The metal hydroxide or metal oxide thus obtained has extremely high purity, with a purity of three nines or more. According to the method of the present invention detailed above, impurities can be substantially to completely removed from an impurity-containing organometallic compound, and high-purity metal hydroxides or oxides can be produced from the organometallic compound thus purified. can be produced, and its industrial value is great. Hereinafter, the method of the present invention will be explained in more detail with reference to Examples, but the present invention is not limited by the following Examples unless the gist thereof is exceeded. Example 1 570 g of triethylaluminum containing various impurities at the concentrations shown in the raw material column of Table 1 was charged into a reactor No. 5 equipped with a stirrer, a condenser, a water dropping tube, etc., and the mixture was heated while maintaining the temperature at 65°C. While stirring at 100rpm
18 g of water diluted with 1000 c.c. of tetrahydrofuran
was supplied over 1 hour to preliminarily hydrolyze triethylaluminum (hydrolysis rate: 10%). The obtained reaction product was separated and removed by filtration, and then 70
After heating and removing tetrahydrofuran at °C, 10 mm
Distilled under reduced pressure with Hg at 97°C to obtain 490 g of purified triethylaluminum. 490 g of the obtained purified triethyl aluminum and 500 c.c. of tetrahydrofuran were charged into a reactor 5 equipped with a stirrer, a condenser, a water dropping tube, etc.
While stirring at 100 rpm and keeping the temperature at 65℃,
Water diluted with 1000 c.c. of tetrahydrofuran
300 g was fed over 3 hours, and triethylaluminum was completely hydrolyzed (main reaction) to obtain aluminum hydroxide. The concentrations of various impurity elements in the obtained aluminum hydroxide were as shown in the aluminum hydroxide column of Table 1.

[Table] Example 2 Into the same reactor as in Example 1, 992 g of triisobutylaluminum containing various impurities as shown in the raw material column of Table 2 and 1000 c.c. of tetrahydrofuran were charged, and the mixture was heated while maintaining the temperature at 65°C. While stirring at 100 rpm, 1.8 g of water diluted with 100 c.c. of tetrahydrofuran was fed over 1 hour to pre-hydrolyze triisobutylaluminum (hydrolysis rate 1%). The resulting reaction product was separated and removed by filtration, and then tetrahydrofuran was removed by heating at 70°C, followed by distillation under reduced pressure at 10 mmHg and 85°C to obtain 850 g of purified triisobutylaluminum. 850 g of the obtained purified isobutyl aluminum,
500 c.c. of tetrahydrofuran was charged into the same reactor as used in Example 1, and hydrolyzed while stirring at 100 rpm and maintaining the temperature at 65°C to obtain aluminum hydroxide. The concentrations of various impurity elements in the obtained aluminum hydroxide were as shown in Table 2.

【table】

[Table] Example 3 Using the same reactor as Example 1, 1020 g of aluminum isopropoxide and isopropanol were added.
Pour 1500c.c. and raise the temperature to 80℃ while stirring at 100rpm.
C., water diluted with 200 c.c. of isopropanol in the amount shown in Table 3 was fed over a period of 1 hour to pre-hydrolyze the aluminum isopropoxide. The resulting reaction product was separated and removed by filtration, and then the isopropanol was removed by heating at 90°C, followed by distillation under reduced pressure at 135°C and 10 mmHg to obtain about 940 g of purified aluminum isopropoxide. Obtained purified aluminum isopropoxide
940 g of isopropanol and 1500 c.c. of isopropanol were charged into the same reactor used in Example 1, and while stirring at 100 rpm and maintaining the temperature at 80°C, 300 g of water diluted with 500 c.c. of isopropanol was added over 3 hours. The aluminum isopropoxide was completely hydrolyzed to obtain aluminum hydroxide. The concentrations of various impurity elements in the obtained aluminum hydroxide were as shown in Table 3.

[Table] From the above results, it is clear that impurities in the raw materials can be effectively removed by hydrolyzing approximately 0.1% or more of the raw materials. Example 4 Using the same reactor as in Example 1, 1422 g of titanium isopropoxide and 1500 g of isopropanol were prepared.
cc, and while stirring at 100 rpm and keeping the temperature at 80°C, 9 g of water diluted with 200 c.c.
%)did. The resulting reaction product was separated and removed by filtration, and then the isopropanol was removed by heating at 90°C, followed by vacuum distillation at 116°C and 10 mmHg to obtain 1280 g of purified titanium isopropoxide. Obtained purified titanium isopropoxide
1280 g of isopropanol and 1500 c.c. of isopropanol were charged into the same reactor used in Example 1, and while stirring at 100 rpm and keeping the temperature at 80°C, 300 g of water diluted with 500 c.c. of isopropanol was added over 3 hours. The titanium isopropoxide was completely hydrolyzed to obtain titanium hydroxide. The concentrations of various impurity elements in the obtained titanium hydroxide were as shown in Table 4.

[Table] Example 5 100 g of an organometallic compound containing impurities at a concentration as shown in the raw material organometallic compound column of Table 5 was charged into a reactor equipped with a stirrer, a condenser, a water dropping tube, etc. It was diluted with 300 g of the solvent shown in the solvent column. Then, 100 rpm while maintaining the temperature shown in the pre-hydrolysis column.
200 g of the solvent shown in the pre-hydrolysis column while stirring at
The organic metal compound was decomposed to the hydrolysis rate shown in the preliminary hydrolysis column of Table 5 by feeding water diluted with water over 1 hour. The obtained reaction product is separated and removed by filtration,
Next, the solvent was removed under the conditions shown in Table 5, followed by further distillation to obtain a purified organic metal. 50 g of the purified organometallic compound obtained and 150 g of the same solvent shown in the preliminary hydrolysis column were mixed in a stirrer, a condenser,
Pour into a 0.5 reactor equipped with a water dropping tube, etc.
While stirring at 100 rpm and maintaining the same temperature as shown in the hydrolysis column, 50 g of water was supplied over 1 hour to completely hydrolyze (main hydrolysis) to obtain a metal hydroxide. The concentrations of various impurity elements in the obtained metal hydroxide were as shown in the metal hydroxide column of Table 5.

【table】

Claims (1)

[Claims] 1 General formula [Formula] or [Formula] in a liquid state (wherein M ₃ is a trivalent element selected from Al or Y,
M ₄ is a tetravalent element selected from Si, Ti or Zr, R ₁ ,
R ₂ , R ₃ and R ₄ are the same or different alkyl, alkoxy or hydrogen atoms) is stirred under stirring conditions.
0.1 to 50% is pre-hydrolyzed to produce a solid reaction product, the pre-reaction product is distilled, the solid reaction product and unreacted organometallic compound are separated by distillation, and the organometallic compound is recovered. and then subjecting the recovered organometallic compound to main hydrolysis to produce a solid metal hydroxide or oxide. A method for producing a high purity metal hydroxide or oxide. 2 Pre-hydrolysis of organometallic compounds is approximately 1-20%
A method for producing a high-purity metal hydroxide or oxide according to claim 1, characterized in that: 3. The method for producing a high-purity metal hydroxide or oxide according to claims 1 to 2, wherein the preliminary hydrolysis reaction is carried out at 0 to 150°C. 4. The method for producing a high-purity metal hydroxide or oxide according to claims 1 to 3, wherein the hydrolysis reaction is carried out at a temperature of 0 to 150°C. 5. A method for producing a high-purity metal hydroxide or oxide according to claims 1 to 4, characterized in that the pre-reactant is subjected to solid-liquid separation treatment before being subjected to distillation.