JPS63227593A - Production of metal alkoxide solution - Google Patents

Abstract

PURPOSE:To advantageously obtain the titled solution for glass production, etc., in high purity and good stability on an industrial scale, by reacting a halide of metal such as vanadium with ethanolamines in the presence of ammonia gas. CONSTITUTION:One or more kinds of halide of metal (e.g. tantalum pentachloride) such as vanadium, niobium and tantalum is reacted with one or more kinds of monoethanolamine, diethanolamine, triethanolamine, etc., in a state dissolved or suspended in 1-4C alcohol while blowing ammonia gas and the resultant solution is treated by passing through an ion exchange resin column chromatography to provide the aimed compound.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides stable alkoxides of elements selected from the group consisting of vanadium, niobium, and tantalum, which have traditionally been considered unstable and difficult to handle. The present invention relates to a method for producing a solution.

[Prior art] Alkoxides of vanadium, niobium, and tantalum are usually obtained in solution form, but they have the property of easily deliquescence or hydrolysis even when exposed to moisture in the air, transforming them into oxides and hydroxides of these elements. It is difficult to handle because it is extremely unstable.

In general, metal alkoxides have the property of being transformed into hydroxides and oxides by hydrolysis or thermal decomposition, and these properties can be used to produce fine powders of high-purity hydroxides or oxides. It is useful as a material in the field of producing glass materials such as porous glass and hollow glass, and in the field of ceramics using composite metal oxides as raw materials. It can also be effectively used as a raw material for producing oxide thin films.

By the way, alkoxides of elements selected from the group consisting of vanadium, niobium, and tantalum are usually prepared by reacting chlorides of these elements with alcohol in the presence of ammonia gas, or by reacting chlorides of these elements with alkoxides of alkali metals. It is synthesized by reacting. By thermally decomposing these synthesized metal alkoxides, fine powders of metal oxides can be obtained, and by hydrolyzing them, oxides or hydroxides can also be obtained. However, metal alkoxides synthesized by the above-mentioned conventional methods are easily deliquesced or hydrolyzed by moisture in the air, making them extremely difficult to handle.

[Problems to be solved by the invention] Metal alkoxides of vanadium, niobium, and tantalum are
For example, when it contains an alkyl group having 1 to 4 carbon atoms, it is usually obtained as a liquid [however, vanadium (I) alkoxide is obtained as a solid], but like other metal alkoxides, it is easily deliquesced by moisture in the air. or undergo hydrolysis. In addition, since these alkoxides are liquid substances, they can be purified by vacuum distillation, but their vapor pressure is extremely low and the degree of vacuum must be extremely high for vacuum distillation, so they are not suitable for industrial use. is problematic.

However, the alkoxides of these three elements are extremely useful as raw materials for obtaining oxides and hydroxides useful as materials in the glass manufacturing field, ceramics field, etc. Moreover, they can be sintered at low temperatures and Because it has the advantage of being able to be completed in a short time, demand is likely to continue to grow, and it is also being used as a raw material for oxide thin films.

The present invention has been made in view of these points, and its object is to provide a metal alkoxide selected from the group consisting of vanadium, niobium, and tantalum, which is stable against moisture in the air, The object of the present invention is to provide a method for producing a stable and easy-to-handle metal alkoxide solution that can be thermally decomposed or hydrolyzed to yield a high-purity fine powder of an oxide or hydroxide.

[Means for Solving the Problems] The structure of the present invention that has achieved the above object includes one or more metal halides selected from the group consisting of vanadium, tantalum, and niobium, and monoethanolamine. , one or more of jetanolamine and triethanolamine (preferably such that the molar ratio of the halide to amine is in the range l:0.5 to 1:5, with the exception that vanadium chloride Time is 1:0.5
The gist of this method is to dissolve or suspend it in an alcohol having 1 to 4 carbon atoms (so that the ratio of carbon atoms is 1 to 1:3), and to proceed with the reaction in the presence of ammonia gas.

Another structure according to the present invention is a metal halide selected from the group consisting of vanadium, niobium, and tantalum.
species, one or more of monoethanolamine, jetanolamine and triethanolamine (preferably the halide to amine ratio is 1:
0.5 to 1:5 (however, in the case of vanadium chloride, the ratio is 1:0.5 to 1:3) dissolved or suspended in an alcohol having 1 to 4 carbon atoms. The gist is that the reaction is allowed to proceed in the presence of ammonia gas, and then the resulting solution is treated with an ion exchange resin.

[Function] Examples of the halides used in the present invention include chlorides, bromides, fluorides, and iodides, but since chlorides are industrially most preferred, chlorides will be representatively explained below. proceed.

In carrying out the method of the present invention, a metal chloride selected from the group consisting of vanadium, niobium, and tantalum and one or more of monoethanolamine, jetanolamine, and triethanolamine (preferably, the chloride and the amine Alcohols having 1 to 4 carbon atoms (so that the molar ratio of Use a solution dissolved or suspended in Chloride dissolves in alcohols up to its saturation concentration, but generally 0.00% chloride is dissolved in alcohols having 1 to 4 carbon atoms.
The amount is preferably 1 to 5 mol, preferably 0.5 to 1 mol.

Vanadium, niobium, and tantalum chlorides can be prepared by conventionally known methods such as vanadium (V) trichloride, niobium chloride (
V) and tantalum chloride (V) are their respective oxides (
V), a carbonaceous mixture, and chlorine gas.

One feature of the present invention is that the metal chloride selected from the group consisting of vanadium, niobium, and tantalum prepared as described above and a specific amine are dissolved or suspended in an alcohol having 1 to 4 carbon atoms. , the reaction proceeds in the presence of ammonia gas.

As the specific amine used here, one or more of monoethanolamine, jetanolamine, and triethanolamine are selected. Even if it belongs to ethanolamines, the general formula % formula % [However, R1+ R2 is an alkyl group (R+)H.

R2 H)], such as N-methylethanolamine,
When N,N-dimethylethanolamine, N-ethylethanolamine, etc. are used, a gel-like substance is produced when the reaction is carried out in the presence of ammonia gas, and a metal alkoxide selected from the group consisting of vanadium, niobium, and tantalum is produced. A stable solution cannot be obtained.

In the present invention, one or more of monoethanolamine, jetanolamine and triethanolamine are generally used in a molar ratio of metal chloride to amine of 1:0.
5 to 1:5, in the case of vanadium 1:0.5 to 1:3, particularly preferred are molar ratios in the range 1:1 to 1:3.

As described above, a metal chloride selected from the group consisting of vanadium, niobium, and tantalum and the above amine are dissolved or suspended in an alcohol having 1 to 4 carbon atoms, and the reaction is allowed to proceed in the presence of ammonia gas. The formation of gel-like or crystalline substances does not occur, and stable vanadium,
An alcohol solution of a metal alkoxide selected from the group consisting of niobium and tantalum is obtained. In particular, the amount of amine is 1 per mole of the metal element constituting the metal alkoxide.
At ~3 mol, this stabilizing effect is significant.

In the present invention, a method of introducing ammonia gas is adopted as a method of promoting the reaction. For example, tantalum pentachloride and the above-mentioned specific amine are dissolved in an alcohol having 1 to 4 carbon atoms, and ammonia gas is introduced to advance the reaction. The amount of ammonia gas blown is preferably in excess of the theoretical amount (theoretical equivalent to the metal halide), for example, at a ratio of about 5.5 to 6.5 moles per mole of tantalum pentachloride. This reaction is an exothermic reaction, and as the reaction progresses, the temperature rises and ammonium chloride is precipitated as a by-product. 1 to 4 carbon atoms selected from the group consisting of
A stable alcoholic solution of a metal alkoxide having an alkyl group can be obtained.

The alcohol solution of metal alkoxide thus obtained is stable for a long period of time without gelation, and is not easily hydrolyzed by moisture in the air. This solution may also be mixed with other organic solvents that are compatible with the alcohol used, such as other alcohols,
It can be diluted with ketones, aromatic hydrocarbons (eg toluene, benzene, xylene, etc.), chloroform, etc.

Note that the alcohol solution of metal alkoxide obtained in this way contains a small amount of chloride, mainly ammonium chloride, as an impurity, and depending on the application, such chloride may be removed to obtain a solution with even higher purity. is desired. However, as mentioned above, alkoxides of vanadium, niobium, and tantalum are essentially liquids, so they cannot be purified to a high degree (removal of chloride) by recrystallization using a solvent, and vacuum distillation cannot be achieved as described above. For these reasons, it is unsuitable as an industrial method. Furthermore, a removal method using the difference in solubility of chloride in a solvent can be considered, but even this method cannot sufficiently achieve the purpose of high purity.

Taking these points into consideration, the inventors of the present invention have repeatedly researched and examined a method that can obtain a highly pure alcoholic solution of a metal alkoxide with simple operations. By subjecting the solution to ion exchange treatment with an anion exchange resin, the amount of chloride (chloride ion) present in the solution is reduced to 1 mole of alkoxide of the element consisting of vanadium, niobium, and tantalum. It has been found that the amount can be reduced to less than /1000 mol.

In carrying out the above purification method according to the present invention, any anion exchange resin can be used as long as it can capture and remove chloride ions in the solution by ion exchange. Strongly basic anion exchange resins having a terminal group are particularly preferred, and those having the former terminal group are particularly preferred.

These ion exchange resins are Amberlyte IRA, Amberlyst A, and Diaion SA.

It is available on the market under trade names such as FA and DOWEX SAR.

In the ion exchange resin treatment, the alcohol solution (containing chloride ions as an impurity) of a metal alkoxide selected from the group consisting of vanadium, niobium, and tantalum, produced as described above, is treated with the anion exchange resin using an arbitrary method. It is carried out by contacting with a resin. The most common method is to pass the solution through a column packed with ion exchange resin. If particularly high purity purification is desired, such purification operations may be repeated several times.

Furthermore, even when the metal alkoxide solution obtained according to the present invention is treated with an ion exchange resin as described above, hydroxides and oxides are produced by hydrolysis of the alkoxide solution by water produced as a by-product during the anion exchange reaction. The chloride ions in the solution can be significantly reduced to 1/1000 mole or less per mole of metal ions in the alkoxide solution, making ideal purification possible.

[Example] The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited to the following examples.

Example 1 358 g of tantalum pentachloride TaCIs (1%) (manufactured by Mitsuwa Chemical) and the amounts of monoethanolamine, jetanolamine, or triethanolamine shown in Table 1.2 were dissolved in 2M of methyl alcohol or ethyl alcohol. Then, ammonia gas was blown at 0.3 fL for 1 minute for 10 hours, and the liquid temperature was 23°C at the start of ammonia gas injection.
However, as the blowing progressed, the temperature of the reaction solution rose, so after that it was moderately cooled in a water bath and maintained at 60°C. After the reaction is completed, the reaction mixture is cooled to room temperature and the by-produced ammonium chloride is filtered off to obtain a methyl alcohol solution of tantalum methoxide containing ethanolamine (Product) or an ethyl alcohol solution of tantalum ethoxide (Product ■). Ta. The condition and storage stability of this product I, ① are shown in Table 1.2.

(Margin below) Table 1 [Stability of tantalum (v) methoxide 1 Δ: 1 to 2 weeks O: Within 1 month O: More than 1 month - Excluded from the target because it is obtained in a gelatinous state.
2 Table [Tantalum (V) ethoxide] Stability Δ
: 1-2 weeks O: Less than 1 month Oat More than 1 month
- Excluded from the scope because it is obtained in a gelatinous state Example 2 Niobium pentachloride NbCIs 270g (1 mol) (manufactured by Mitsuwa Kagaku) and the amounts shown in Table 3.4 of monoethanolamine, jetanolamine or triethanolamine were added. Methyl alcohol or isopropyl alcohol 2fL
ammonia gas at 0.3 fL for 1 min.
I took the time. The liquid temperature at the start of ammonia gas blowing was 26°C, but as the blowing progressed, the temperature of the reaction liquid rose, so after that it was moderately cooled in a water bath and brought to 60°C.
was held at After the reaction is completed, it is cooled to room temperature and the by-produced ammonium chloride is filtered off, resulting in a methyl alcohol solution of niobium methoxide containing ethanolamine (product I).
Alternatively, an isopropyl alcohol solution of niobium isopropoxide (product ■) was obtained. The state and storage stability of this product are shown in Tables 3 and 4.

Example 3 173 g (1 mol) of vanadium oxytrichloride VOCl3 (manufactured by Kishida Chemical Co., Ltd.) and the amounts shown in Table 5 of monoethanolamine, jetanolamine or triethanolamine were dissolved in tertiary butyl alcohol 21, and ammonia gas was blown in at a rate of 0.21/min for 9 hours. The liquid temperature was 24°C at the start of ammonia gas blowing, but as the blowing progressed, the temperature of the reaction liquid rose, so after that it was heated in a water bath to moderate the temperature. After completion of the six reactions, which were cooled and maintained at 60° C., the mixture was cooled to room temperature and by-produced ammonium chloride was filtered off to obtain a tertiary butyl alcohol solution (product) of vanadyl butoxide containing ethanolamine. The condition and storage stability of this product are shown in Table 5.

(Left below) Table 3 [Niobium (V) methoxide] Stability ×:
Within 1 week Δ: l~2 weeks O: Within 1 month o
: For more than 1 month - Excluded because it is obtained in the form of two gels Table 4 [
Niobium (V) impropoxide 1 stability Δ: 1-2
Weeks 0: Within 1 month o: More than 1 month - Excluded from the target because it is obtained in two gel-like forms Table 5 [Vanadyl butoxide J stability ×: Within 1 week Δ; l~2 weeks O: Within 1 month m: Gel Excluded from the scope because it is obtained in the form of Example 4 3157 g (1 mol) of vanadium trichloride VCl (manufactured by Kishida Chemical Co., Ltd.) and the amounts shown in Table 6 of monoethanolamine, jetanolamine, or triethanolamine are dissolved in 2 parts of methyl alcohol. and ammonia gas at 0.21/
It blew for 9 hours in minutes.

The liquid temperature at the start of ammonia gas blowing was 28°C, but as the blowing progressed, the temperature of the reaction liquid rose, so after that it was maintained at 60°C by cooling it appropriately in a water bath. After the reaction was completed, the mixture was cooled to room temperature and the by-produced ammonium chloride was filtered off to obtain a methyl alcohol solution (product) of vanadium methoxide containing ethanolamine.

The condition and storage stability of this product are shown in Table 6.

(Margin below) Table 6 [Vanadium (m) methoxide] Stability X: Within 1 week Δ: 1 to 2 weeks O: Within 1 month
Example 5 Excluded from the scope because it is obtained in a gelatinous state Part of the methyl alcohol solution of tantalum methoxide obtained in Example 1 (using 1 mole of monoethanolamine for 1 mole of tantalum pentachloride) (liquid volume: 5001 So 28
000 g of chloride ion CI-, Ta205-(
2 containing 45 g of strongly basic anion exchange resin Amberly) filled with IRA-410 (manufactured by Organo).
It was passed through a column with a diameter of 0 and a diameter of 950 H at a flow rate of 2.5 I/min. By repeating this operation four times, the chloride ion content of the liquid obtained was 28,000 mg before treatment, but it was reduced to 6 mg (0.013 mg per oxide equivalent).
%, 8/10000 mol per 1 mol of tantalum), and it was confirmed that most of the impurity chloride ions were removed.

Example 6 A portion of the methyl alcohol solution of niobium methoxide obtained in Example 2 (using 1 mole of triethanolamine per 1 mole of niobium pentachloride) (2300
01 g of chloride ion CI-.

(containing 20,528 g of Nb) was added to a column with a diameter of 20 mm and a diameter of 980 mm filled with a strongly basic anion exchange resin Amberly) IRA-410 (manufactured by Organo).
It was passed at a flow rate of 1/min. By repeating this operation four times, the chloride ion content of the liquid obtained was 6.7 rag, which was 23,000 vsg before treatment (0.024% per oxide equivalent, 9/10 per mol of niobium).
000 mol), and it was confirmed that most of the impurity chloride ions were removed.

[Effects of the Invention] The present invention is configured as described above, and its effects can be summarized as follows.

(1) It is now possible to obtain vanadium, niobium, and tantalum alkoxides with alkyl groups having 1 to 4 carbon atoms in a stable solution state, which were previously obtained in solution form but were extremely unstable. Ta.

(2) When the alkoxide having an alkyl group having 1 to 4 carbon atoms such as vanadium, niobium, or tantalum in a solution state is treated with an ion exchange resin, its purity can be dramatically increased.

(3) By adding water to an alcohol solution of these metal alkoxides and subjecting them to hydrolysis or thermal decomposition, high-purity fine powders can be obtained, which can be used in the glass manufacturing field, ceramics field, and as a raw material for oxide thin films. The usefulness in those fields can be further increased.

Claims (2)

[Claims] (1) One or more metal halides selected from the group consisting of vanadium, niobium, and tantalum, and one or more of monoethanolamine, diethanolamine, and triethanolamine with a carbon number of 1 to 4.
A method for producing a metal alkoxide solution, which comprises dissolving or suspending the metal alkoxide solution in an alcohol and carrying out the reaction in the presence of ammonia gas. (2) one or more metal halides selected from the group consisting of vanadium, niobium, and tantalum, and one or more of monoethanolamine, diethanolamine, and triethanolamine, each having a carbon number of 1 to 4;
A method for producing a metal alkoxide solution, which comprises dissolving or suspending the metal alkoxide solution in an alcohol, performing a reaction in the presence of ammonia gas, and then treating the resulting solution with an ion exchange resin.