JPH09278489A - Coating solution and formation of thin film using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating solution excellent in stability, long in pot life and capable of forming an inexpensive metal oxide thin film by using an anion metallic complex expressed by a specific formula and having an alkylamine as a counter ion. SOLUTION: The coating solution contains at least one kind of the anion metallic complex expressed by the formula [(A1)m (A2)n ][MB] and having the alkylamine as the counter ion. In the formula, A1 is an alkylamine expressed by the general formula, N+ R1 R2 R3 R4 (each of R<1> to R<4> expresses hydrogen atom or a 1-10C alkyl group and at least one of R<1> to R<4> is an alkyl group), A2 expresses hydrogen ion or univalent or bivalent cation, each of (m) and (n) expresses the numbers of >=0, M expresses at least one kind of a metallic ion of group 1 to 16 in Periodic table and/or its oxo form and B is expressed by a formula, R<5> R<6> -N-R<7> -N-R<8> R<9> or R<5> -R<6> -N-R<7> -N-R<10> R<7> -N-R<8> R<9> (each of R<5> , R<6> , R<8> , R<9> , R<10> expresses -CH2 COOH, -CH2 CH2 OH or the like, R<7> expresses -CH2 CH2 -, -CH2 CH2 CH2 - or the like).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating solution and a method for producing a thin film using the same, and particularly to a coating solution for producing a metal oxide thin film by coating on a substrate and baking the same. The present invention relates to a thin film manufacturing method using.

[0002]

2. Description of the Related Art Conventionally, it is known that a metal oxide thin film is produced by applying a coating solution containing metal ions onto a substrate and baking the coating solution. For example, water is added to a solution in which a metal alcoholate is dissolved in an organic solvent, and the metal alcoholate is hydrolyzed to prepare a sol containing metal ions. A coating film is prepared by applying the sol solution as a coating solution on a substrate. A metal oxide thin film is obtained by baking this coating film.

In recent years, a sol solution was prepared by hydrolyzing a metal alcoholate solution containing acetylacetone as an organic ligand as a coating solution, or a solution containing metal soap was used to carry out the same method as described above. Alternatively, a metal oxide thin film can be prepared.

These methods are called the so-called sol-gel method (Sakuo Sakuo, Science of sol-gel method, Agne Jofusha, 1988, 85-103).
page).

[0005]

However, although the above metal oxide film can be produced by the sol-gel method, it has some problems.

Since the metal alcoholate has a high hydrolysis rate, it is difficult to control the hydrolysis rate. For this reason, if left as it is, gelation proceeds, which makes it unusable as a coating liquid, or there is a problem that the viscosity changes and a uniform thick film cannot be obtained. For example, titanium tetraisopropoxide has a very high hydrolysis rate, so that gelation proceeds only by exposure to air to form a white gel, and thus cannot be used as a coating solution. In order to solve such a problem, a method using a metal alcoholate containing acetylacetone has been proposed, but even this method cannot sufficiently control the hydrolysis rate.

Further, when a composite oxide film containing a plurality of metal ions is produced, if the hydrolysis rates are different, there is a problem that these metal ions cannot be mixed uniformly.

Further, these metal alcoholates are generally expensive and the raw material cost is high. In order to solve this problem, there is a method using metal soap as a raw material. However, this method has a problem that a dense film cannot be obtained after firing because the content of organic substances is large.

Therefore, an object of the present invention is to solve the above problems and to provide a stable coating solution, a long pot life and a low cost when a metal oxide film is produced by coating and subsequent firing steps. It is to provide a coating liquid for producing a metal oxide film.

Another object of the present invention is to provide a method for forming a metal oxide film using the above coating solution. In particular, another object of the present invention is to provide a method for easily forming a composite metal oxide thin film in which a plurality of metal ions are uniformly mixed.

[0011]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that an anionic metal complex containing a predetermined organic ligand having a predetermined alkylamine as a counter ion is coordinated. The inventors have found that the above-mentioned problems can be solved by using the applied coating solution, and arrived at the present invention.

The first invention is the following general formula (1):

[(A1) _m (A2) _n ] [MB] (1) [A1 in the formula is represented by the general formula N ⁺ (R ¹ ) (R ² ) (R ³ ).
(R ⁴ ) (wherein R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom or an alkyl group having ¹ to 10 carbon atoms, and these R ¹ , R ² , R ³ and R ⁴ are , Which may be the same or different, but at least one represents an alkyl group),
Represents a hydrogen ion or a +1 or +2 cation, and m and n are cations {(A1) _m (A2)
_n } represents a number of 0 or more that satisfies the absolute value of the charge of the complex anion [MB], and M is 1 to 16 in the periodic table.
Represents at least one metal ion selected from the group consisting of groups and / or an oxo form thereof, and B is represented by the following general formula (2) or (3):

(R ⁵ ) (R ⁶ ) -N-R ⁷ -N- (R ⁸ ) (R ⁹ ) ... (2)

Embedded image (R^Five) (R⁶) -NR⁷-N- (R^Ten) (R⁷) -N- (R⁸) (R⁹) ··· (3) (R in the formula^Five, R⁶, R⁸, R⁹And R^TenIs -CH
_TwoCOOH, -CH_TwoCH_TwoCOOH, -CH_TwoCH_Two
OH, -CH_TwoCH_TwoCH_TwoOH, -CH_TwoPO _ThreeH_Two
Or -CH_TwoCH_TwoPO_ThreeH_TwoAnd these R^Five,
R⁶, R⁸, R⁹And R^TenAre the same but different
R may⁷Is -CH_TwoCH_Two-, -CH_Two
CH_TwoCH_Two-Or-CH_TwoCH (OH) CH_TwoIn
A)) having an alkylamine as a counter ion
Characterized by containing at least one kind of a nonionic metal complex
It is in the coating liquid.

A second aspect of the present invention is a method for forming a metal oxide film, characterized in that a metal oxide film is produced by applying the above-mentioned coating liquid on a substrate and baking it.

The present invention will be described in more detail below. Here, the metal complex used is a compound in which at least one arbitrary ligand such as organic or inorganic is coordinated to a metal ion, and its structure and chemical properties are described in inorganic chemistry (F.A. -Cotton and Gee Wilkinson, translated by Katsushi Nakahara, 8th edition 1980, Baifukan).

In the present invention, in the above general formula,
M is Al, Si, V, Fe, Co, Cr, Ni, Zn,
Ga, Y, Zr, Nb, Mo, In, Sn, Pb, H
A metal complex which is at least one selected from the group consisting of f, Ta, W, Cu, Mg, Ca, Sr and Ba, and / or an oxo form thereof is preferable.

Examples of the ligand B include those shown below.

Embedded image

Examples of the anion metal complex having an alkylamine containing the ligand B as a counter ion include those shown below.

Embedded image

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The anion metal complex used in the present invention is stable, and the pot life of a coating solution containing this complex as an alkylamine counter ion is long. By using a coating solution formed by mixing a plurality of alkylamines as counter ions with an anion complex, a composite film containing a plurality of metal ions can be easily formed, and a thin film in which these metal ions are uniformly mixed can be formed. Obtainable.

In the prior art in which a solution containing a plurality of metal alcoholates is hydrolyzed, the hydrolysis rate of each metal alcoholate is different, so that a polymer in which the same kind of metal ions are aggregated is easily generated, and a plurality of metal ions are not formed. It is difficult to obtain a uniformly dispersed thin film.

On the other hand, in the present invention, even if a coating solution is prepared by using an anion metal complex containing alkylamine as a counter ion and containing a plurality of metal ions, the metal ions are uniformly mixed. A thin film in which these metal ions are uniformly dispersed can be produced. Furthermore, unlike the metal alcoholate, this anion metal complex having an alkylamine as a counter ion can be manufactured at low cost. Further, unlike the metal soap, the anion metal complex having an alkylamine as a counter ion used in the present invention has a small organic substance content contained in the complex molecule, so that a dense film can be formed after coating and baking.

The coating solution of the present invention can be produced by dissolving an anionic metal complex in an arbitrary solvent with alkylamine as a counter ion. In consideration of applicability, drying property, solution preservability, and the like, the solvent is preferably water, alcohols such as methanol, ethanol, isopropyl alcohol, and normal butyl alcohol, acetone, and a mixed solvent thereof. The anion metal complex can be dissolved in these solvents at any concentration, but the amount of the anion metal complex is 1 to 3 from the viewpoint of coating properties and drying properties.
A range of 0% by weight is preferred. The amount of anion metal complex is 1
When it is less than 30% by weight, the coating property deteriorates, and when it exceeds 30% by weight, the drying property deteriorates.

The coating solution of the present invention can be coated on a substrate by any method such as a flow method, a curtain coating method, a dipping method. As the substrate used in the present invention, any substrate can be used, but in view of resistance to the firing temperature, glasses such as soda lime glass, low expansion glass and quartz glass, metals such as iron, aluminum and SUS are used. Ceramics such as silica, alumina, aluminum nitride, and polymer films such as polyimide are preferably used. Further, in addition to such a substrate, a coating liquid can be applied to any thin or thick film.

According to the method of the present invention, it is preferable that after the coating liquid is applied to the substrate, firing is performed in at least one gas selected from the group consisting of air, oxygen gas and nitrogen gas. It is also possible to provide a plurality of firing steps, for example, first firing in air and then firing in nitrogen. The firing temperature is not particularly limited, and the firing temperature can be set in multiple stages, for example, the coating film is first fired at 200 ° C. and then at 500 ° C.

[0024]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention.

The anion metal complex having an alkylamine as a counter ion can be synthesized, for example, by the following method.

Synthesis Example Synthesis of Complex 2 In a beaker, 4.93 g of cobalt (II) chloride hexahydrate was dissolved in about 40 ml of water, and 6.01 g of the solution was dissolved.
B1 of was added with stirring and the mixed solution was heated at 90 ° C. Once cooled to 55 ° C, add 1 to this heterogeneous solution.
2.81 g of tributylamine was added slowly. The mixture was heated and stirred at the same temperature until a transparent homogeneous solution was obtained.
While cooling the solution with ice, 30 ml of 3% hydrogen peroxide solution
Was gradually added, and then the mixture was heated and stirred at 55 ° C. for 1 hour.
The resulting deep red-purple solution was concentrated under reduced pressure to 30 ml, and the solution was left at room temperature overnight. The generated precipitate was filtered off, washed with a small amount of acetonitrile, and then dried under reduced pressure to obtain complex 2.

Synthesis of Complex 3 In a beaker, 4.89 g of cobalt (II) chloride hexahydrate was dissolved in about 40 ml of water and the aqueous solution was added with 6.63 g.
No. B2 was added with stirring and the mixed solution was heated to 90 ° C. Once cooled to 55 ° C, add 1 to this heterogeneous solution.
2.61 g of tributylamine was added slowly. The mixture was heated and stirred at the same temperature until a transparent homogeneous solution was obtained.
While cooling the solution with ice, 30 ml of 3% hydrogen peroxide solution
Was gradually added, and then the mixture was heated with stirring at 55 ° C. for 2 hours.
The resulting deep red-purple solution was concentrated under reduced pressure to 20 ml. Add 60 ml of methanol and 200 ml to this concentrate.
And diethyl ether were added with stirring to deposit a precipitate. The generated precipitate was separated by filtration, washed with a small amount of diethyl ether, and then dried under reduced pressure to obtain complex 3.

Synthesis of Complex 4 15.40 g of cobalt (II) chloride hexahydrate was dissolved in about 100 ml of water in a beaker, and 20.
00g of B2 was added with stirring and the mixed solution was heated to 90 ° C.
Heated. To this heterogeneous solution was gradually added 38.01 g of potassium acetate. The mixture was heated and stirred at the same temperature until a transparent homogeneous solution was obtained. To this solution, 60 ml of 3% hydrogen peroxide solution was gradually added, and then heated and stirred at 90 ° C. for 1 hour. The resulting deep red-purple solution was concentrated under reduced pressure to 30 ml. To this concentrated solution, 90 ml of methanol and 300 ml of diethyl ether were added with stirring to deposit a precipitate. The generated precipitate was filtered off, washed with a small amount of diethyl ether, and dried under reduced pressure.

10.00 g of the obtained precipitate was added to 40 ml of water.
To obtain a potassium salt aqueous solution. Wet volume of this aqueous solution adjusted to tetrabutylammonium type 300 ml
The cation exchange resin (Dowex 50W-X2) was injected from the top of a glass column (45 × 2 cm), and the colored components that passed through the resin were collected. The aqueous solution was concentrated under reduced pressure to 20 ml. To this concentrated solution, 60 ml of methanol and 200 ml of diethyl ether were added with stirring to deposit a precipitate. After allowing to stand overnight for aging, the formed precipitate was filtered off, washed with a small amount of diethyl ether, and then dried under reduced pressure to obtain complex 4.

Synthesis of Complex 5 In a beaker, 3.58 g of cobalt (II) chloride hexahydrate was dissolved in about 40 ml of water, and 4.38 g of the solution was dissolved.
B1 of was added with stirring and the mixed solution was heated to 90 ° C. Once cooled to 55 ° C, add 1 to this heterogeneous solution.
0.28 g tripentylamine was added slowly. The mixture was heated and stirred at the same temperature until a transparent homogeneous solution was obtained. While cooling the solution with ice, 30% hydrogen peroxide solution 30%
ml was gradually added, and then heated and stirred at 55 ° C. for 1 hour to obtain a transparent and uniform complex 5.

Synthesis of Complex 8 In a beaker, 5.81 g of B1 was added to about 40 ml of water heated to 90 ° C. with stirring, and 4.36 g of zinc (II) acetate dihydrate was added to the aqueous solution. added. To this heterogeneous solution was slowly added 9.03 g tripentylamine. The mixture was heated and stirred at 90 ° C. for 2 minutes to obtain a transparent and uniform complex 8.

Synthesis of Complex 9 In a beaker, 6.51 g of B2 was added to about 100 ml of water heated to 90 ° C. with stirring, and 3.35 g of indium (III) hydroxide hydrate was added in a 3-fold molar ratio. A slight excess of hydrochloric acid was added to the aqueous solution instead of indium (III) chloride. After cooling once to 70 ° C. (below the boiling point of 2-propanol), 40 ml of 2-propanol was added, and 17.93 g of tripentylamine was gradually added to this heterogeneous solution. The mixture was heated and stirred at the same temperature until a transparent and uniform solution was obtained. The solution was cooled to room temperature and free unreacted tripentylamine was removed by ether extraction. The solution becomes cloudy when excess amine is present. Also in this case, transparent and uniform complex 9 was obtained by heating.

Synthesis of Complex 10 In a beaker, 3.88 g of copper (II) acetate monohydrate 9 was added.
Add to about 50 ml of water heated to 0 ° C with stirring,
To the aqueous solution was added 5.66 g of B11. To the solution in which the color of the solution changed from blue to green, 9.13 g of tripentylamine was gradually added. The mixture was heated and stirred at 90 ° C. for 30 minutes to obtain a blue transparent uniform complex 10.

Synthesis of Complex 11 In a beaker, 5.895 g of B5 was added to about 100 ml of water heated to 90 ° C. with stirring, and 4.51 g of tin (II) chloride dihydrate was added to the aqueous solution. added. To this heterogeneous solution, 18.06 g tripentylamine was slowly added. After cooling once to 60 ° C. (below the boiling point of 2-propanol), 100 ml of 2-propanol was added, and the mixture was heated and stirred for 1 hour until a transparent homogeneous solution was obtained at the same temperature to obtain a transparent and homogeneous complex 11. It was

Synthesis of Complex 13 In a beaker, 5.87 g of B1 was added with stirring to about 150 ml of water heated to 90 ° C. 7.71 g of yttrium (III) nitrate hexahydrate was added to the aqueous solution.
To this heterogeneous solution was gradually added 18.20 g tripentylamine. After cooling to 80 ° C (below the boiling point of 2-propanol), 100 ml of 2-propanol
Was added and the mixture was heated and stirred at the same temperature until a transparent homogeneous solution was obtained. The solution was cooled to room temperature and free unreacted tripentylamine was removed by ether extraction. The solution becomes cloudy when excess amine is present. Also in this case, transparent and uniform complex 13 was obtained by heating.

Synthesis of Complex 14 In a beaker, 5.56 g of lead (II) chloride was dissolved in about 40 ml of water, and 6.02 g of B1 was added to the solution.
The mixture was added with heating and stirring at 0 ° C. Add to this heterogeneous solution 18.
24 g of tripentylamine was added slowly. 90 ° C
After stirring for 30 minutes, a transparent and uniform complex 14 was obtained.

Synthesis of Complex 16 In a beaker, 5.76 g of B7 was added with stirring to about 100 ml of water heated to 80 ° C. 5.4 g of iron (III) chloride hexahydrate was added to this aqueous solution. To this heterogeneous solution was slowly added 10 g of tripropylamine. 6
After cooling to 0 ° C once, 2-propanol 100 ml
Was added and the mixture was heated and stirred at the same temperature until a transparent homogeneous solution was obtained. The solution was cooled to room temperature and free unreacted tripropylamine was removed by ether extraction. The solution becomes cloudy when excess amine is present. Also in this case, transparent and uniform complex 16 was obtained by heating.

Synthesis of Complex 23 In a beaker, 60.1 g of B1 was added to about 150 ml of water heated to 90 ° C. with stirring. 5.56 g of lead (II) chloride was added to this aqueous solution. 10 in this heterogeneous solution
g of tripropylamine was added slowly. After cooling once to 80 ° C., 100 ml of 2-propanol was added, and the mixture was heated and stirred at the same temperature until a transparent homogeneous solution was obtained. The solution was cooled to room temperature and free unreacted tripentylamine was removed by ether extraction. The solution becomes cloudy when excess amine is present. Also in this case, the transparent and uniform complex 23 was obtained by heating.

Synthesis of Complex 24 In a beaker, 5.56 g of B12 was added to about 100 ml of water heated to 90 ° C. with stirring, and 4.75 g of nickel (II) chloride hexahydrate was added to the aqueous solution. added. To this heterogeneous solution was slowly added 10 g of tripropylamine. After cooling once to 80 ° C., 100 ml of 2-propanol was added, and the mixture was heated and stirred at the same temperature until a transparent homogeneous solution was obtained. The solution was cooled to room temperature and free unreacted tripropylamine was removed by ether extraction. The solution becomes cloudy when excess amine is present. Also in this case, the transparent and uniform complex 24 can be obtained by heating.
was gotten.

Example 1 Anion metal complex 1 having an alkylamine as a counter ion was dissolved in ethanol to prepare a 10 wt% solution, which was used as a coating solution. This coating solution was applied onto soda lime glass by a flow method to obtain a coating film free from pinholes and cissing defects. This coating film was baked in air at 500 ° C. for 30 minutes to obtain a brown-colored thin film. This thin film has a film thickness of 100n
There was no variation in m and it was uniform. In addition, there was no failure such as pinholes, cissing and cracks in the thin film. When this thin film was analyzed by elemental analysis and X-ray diffraction,
It was a cubic phase with a composition of Co ₃ O ₄ . When the coating solution was allowed to stand at room temperature for one month, the coating solution remained transparent without clouding or precipitation and did not change in viscosity. One month later, when the same test as above was conducted using this coating solution, the same result as above was obtained.

Example 2 A solution of anion metal complex 8 having an alkylamine as a counter ion was concentrated to 5 ml, and ethanol was added to this concentrated solution to make 96 ml. This coating solution was applied onto soda lime glass by a dipping method to obtain a coating film free from pinholes and cissing defects. This coating in air 500
It was baked at 40 ° C. for 40 minutes to obtain a transparent thin film. This thin film had a thickness of 200 nm and was uniform without variation.
In addition, there was no failure such as pinholes, cissing and cracks in the thin film. When this thin film was analyzed by elemental analysis and X-ray diffraction, it was a crystal having a composition of ZnO. When the coating solution was allowed to stand at room temperature for one month, the coating solution remained transparent without clouding or precipitation and did not change in viscosity.
One month later, when the same test as above was conducted using this coating solution, the same result as above was obtained.

Example 3 A solution of anion metal complex 9 having an alkylamine as a counter ion was concentrated to 5 ml, and ethanol was added to this concentrated solution to make 280 ml. This coating solution was applied onto soda lime glass by a flow method to obtain a coating film free from pinholes and cissing defects. 450 in air
It was baked at 60 ° C. for 60 minutes to obtain a transparent thin film. This thin film had a thickness of 150 nm and was uniform without variation.
In addition, there was no failure such as pinholes, cissing and cracks in the thin film. When this thin film was analyzed by elemental analysis and X-ray diffraction, it was a crystalline body having a composition of In ₂ O ₃ . When the coating solution was allowed to stand at room temperature for one month, the coating solution remained transparent without clouding or precipitation and did not change in viscosity. One month later, when the same test as above was conducted using this coating solution, the same result as above was obtained.

Example 4 Anion metal complex 11 having an alkylamine as a counter ion
The solution of 1 was concentrated to 5 ml, and ethanol was added to this concentrated solution to make 95 ml. This coating solution was applied onto borosilicate glass by a dipping method to obtain a coating film free from pinholes and cissing defects. 60 in air
It was baked at 0 ° C. for 50 minutes to obtain a transparent thin film. This thin film had a thickness of 250 nm and was uniform without variation.
In addition, there was no failure such as pinholes, cissing and cracks in the thin film. When this thin film was analyzed by elemental analysis and X-ray diffraction, it was a crystal having a composition of SnO ₂ . When the coating solution was allowed to stand at room temperature for one month, the coating solution remained transparent without clouding or precipitation and did not change in viscosity.
One month later, when the same test as above was conducted using this coating solution, the same result as above was obtained.

Example 5 Anion metal complex 13 having an alkylamine as a counter ion
The solution of 1 was concentrated to 10 ml, and isopropanol was added to this concentrated solution to make 150 ml. This coating solution was applied onto quartz glass by a flow method to obtain a coating film free from pinholes and cissing defects. 60 in air
It was baked at 0 ° C. for 50 minutes to obtain a transparent thin film. This thin film had a thickness of 100 nm and was uniform without variation.
In addition, there was no failure such as pinholes, cissing and cracks in the thin film. When this thin film was analyzed by elemental analysis and X-ray diffraction, it was a crystal having a composition of Y ₂ O ₃ . When the coating solution was allowed to stand at room temperature for one month, the coating solution remained transparent without clouding or precipitation and did not change in viscosity.
One month later, when the same test as above was conducted using this coating solution, the same result as above was obtained.

Example 6 Anion metal complex 16 having an alkylamine as a counter ion
The coating solution of was applied onto soda lime glass by a dipping method to obtain a coating film free from pinholes and cissing defects. This coating film was baked in air at 500 ° C. for 50 minutes to obtain a transparent thin film. This thin film had a film thickness of 180 nm and was uniform without variation. In addition, there was no failure such as pinholes, cissing and cracks in the thin film. When this thin film was analyzed by elemental analysis and X-ray diffraction, it had a composition of Fe ₂ O ₃ . When the coating solution was allowed to stand at room temperature for one month, the coating solution remained transparent without clouding or precipitation and did not change in viscosity. One month later, when the same test as above was conducted using this coating solution, the same result as above was obtained.

Example 7 Anion metal complex 19 having an alkylamine as a counter ion
The coating solution of was applied onto borosilicate glass by a spinner method to obtain a coating film free from pinholes and cissing defects.
This coating film was baked in air at 550 ° C. for 45 minutes to obtain a transparent thin film. This thin film had a thickness of 230 nm and was uniform without variation. Also, pinholes in the thin film,
There were no failures such as cissing and cracks. When this thin film was analyzed by elemental analysis and X-ray diffraction, Nb ₂ (N
b ₂ O ₅₎ had a composition of O _5. Apply coating solution at room temperature 1
When left for a month, the coating liquid remained transparent without white turbidity or precipitation, and the viscosity did not change. One month later, when the same test as above was conducted using this coating solution, the same result as above was obtained.

Example 8 Anion metal complex 23 having an alkylamine as a counter ion
The coating solution of was applied onto borosilicate glass by a spinner method to obtain a coating film free from pinholes and cissing defects.
This coating film was baked in air at 530 ° C. for 20 minutes to obtain a transparent thin film. This thin film had a uniform thickness with a thickness of 120 nm. Also, pinholes in the thin film,
There were no failures such as cissing and cracks. When this thin film was analyzed by elemental analysis and X-ray diffraction, it had a composition of PbO ₂ . When the coating solution was allowed to stand at room temperature for one month, the coating solution remained transparent without clouding or precipitation and did not change in viscosity. One month later, when the same test as above was conducted using this coating solution, the same result as above was obtained.

Example 9 Anion metal complex 24 having an alkylamine as a counter ion
The coating liquid of was applied onto quartz glass by a spinner method to obtain a coating film free from pinholes and cissing defects. This coating film was baked in air at 600 ° C. for 40 minutes to obtain a transparent thin film. This thin film had a thickness of 160 nm and was uniform without variation. In addition, there was no failure such as pinholes, cissing and cracks in the thin film. When this thin film was analyzed by elemental analysis and X-ray diffraction, it had a NiO composition. When the coating solution was allowed to stand at room temperature for one month, the coating solution remained transparent without clouding or precipitation and did not change in viscosity. One month later, when the same test as above was conducted using this coating solution, the same result as above was obtained.

Comparative Example 1 Titanium tetraisopropoxide (28.4 g) was dissolved in absolute ethanol (200 ml). While stirring this solution, 60% HNO _{3 (1} ml) and water (1.8 ml) were gradually added at room temperature, and stirring was continued for another 30 minutes to prepare a titania sol coating solution. This coating solution was applied on soda lime glass by a flow method and baked at 500 ° C. for 30 minutes to obtain a transparent thin film. This thin film has a film thickness of 100n
There was no variation in m and it was uniform. In addition, there was no failure such as pinholes, cissing and cracks in the thin film. When this thin film was analyzed by elemental analysis and X-ray diffraction, T
It was a polycrystal of iO ₂ . When this coating liquid was left at room temperature for one month, the coating liquid became cloudy from the third day. After 3 days, the same test as above was conducted using this coating solution, but a devitrified film was obtained, and a transparent film could not be prepared. The coating solution thickened on the 10th day and coating was impossible.

Comparative Example 2 A coating solution was prepared in the same manner as in Comparative Example 1 except that 1 ml of 60% HNO ₃ and 3.0 ml of water were used.
The liquid became cloudy rapidly and could not be used as a coating liquid.

[0051]

[Table 1]

[0052]

[Table 2]

[0053]

According to the present invention, by preparing a coating liquid containing at least one anion metal complex having an alkylamine as a counter ion, a coating liquid having a long pot life and a low manufacturing cost can be provided. it can.

Further, according to the method of the present invention, a dense metal oxide thin film can be easily obtained by applying and baking the coating solution.

Claims (5)

[Claims] 1. The following general formula (1): [(A1)]_m(A2)_n] [MB] (1) [A1 in the formula is the general formula N]⁺(R¹) (R^Two) (R^Three)
(R^Four) (R in the formula¹, R^Two, R^ThreeAnd R^FourIs it
Alkyl each having a hydrogen atom or 1-10 carbon atoms
On the basis of these R¹, R^Two, R^ThreeAnd R^FourRespectively
They may be the same or different, but at least one
And represents a hydrogen atom or a positive ion having a valence of +1 or +2.
Represents on, m and n are cations [(A1)_m(A2)_n] Is an illusion
Meets the absolute value of the charge of the anion [MB]
Represents a number greater than or equal to 0, and M is a small number selected from the group consisting of groups 1 to 16 of the periodic table.
Represents one metal ion and / or its oxo form
Where B is the following general formula (2) or (3):^Five) (R⁶) -NR⁷-N- (R⁸) (R⁹) ・ ・ ・ ・ ・ (2) [Chemical formula 3] (R^Five) (R⁶) -NR⁷-N- (R^Ten) (R⁷) -N- (R⁸) (R⁹) ··· (3) (R in the formula^Five, R⁶, R⁸, R⁹And R^TenIs -CH
_TwoCOOH, -CH_TwoCH_TwoCOOH, -CH_TwoCH_Two
OH, -CH_TwoCH_TwoCH_TwoOH, -CH_TwoPO _ThreeH_Two
Or -CH_TwoCH_TwoPO_ThreeH_TwoAnd these R^Five,
R⁶, R⁸, R⁹And R^TenAre the same but different
R may⁷Is -CH_TwoCH_Two-, -CH_Two
CH_TwoCH_Two-Or-CH_TwoCH (OH) CH_TwoIn
A)) having an alkylamine as a counter ion
Characterized by containing at least one kind of a nonionic metal complex
Coating liquid. 2. The coating liquid according to claim 1, wherein the content of the anionic metal complex is in the range of 1 to 30% by weight. 3. M is Al, Si, V, Fe, Co, C
r, Ni, Zn, Ga, Y, Zr, Nb, Mo, In,
Sn, Pb, Hf, Ta, W, Cu, Mg, Ca, Sr
2. The coating liquid according to claim 1, which is at least one selected from the group consisting of and Ba and / or an oxo form thereof. 4. A method for producing a thin film, which comprises forming a metal oxide film by applying the coating liquid according to any one of claims 1 to 3 on a substrate and baking the coating liquid. 5. The method for producing a thin film according to claim 4, wherein the baking is performed in at least one gas selected from the group consisting of air, oxygen gas and nitrogen gas.