JPH0122684B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a new material useful for manufacturing various electronic components and a method for manufacturing the same. Tungsten oxide, such as tungsten trioxide (WO ₃ ), exhibits various unique electrical properties and is therefore widely used as a manufacturing material for electronic components or as a component of such materials. By the way, when metal oxides are generally supplied as electronic component materials, it is often required that they be supported as a film on the surface of a substrate such as glass, various metals, ceramics, plastics, semiconductors, etc. Therefore, attempts have been made to support tungsten oxide on a substrate by a coating method, but this has not been successful so far because it is difficult to apply tungsten trioxide as a solution to the surface of the substrate. Therefore, in the field of electronic component materials, forming a tungsten oxide film on the surface of a substrate has become an important issue. The present inventors have conducted various studies to solve this problem, and have found that phosphotungstic acid is superior to tungsten trioxide, which has been used as a source of tungsten oxide, in terms of solution formation properties. We focused on this and tried to utilize it. However, phosphotungstic acid, water,
Even if it is dissolved in a solvent such as alcohol and baked after being applied to the surface of a substrate, the surface will simply whiten and peel off when rubbed, and a uniform and stable continuous film will not be formed. Therefore, as a result of further research, the present inventors discovered that the adhesion of this phosphotungstic acid film was significantly improved when a film-forming aid was used in combination.Based on this knowledge, the present invention was made. It came to this. That is, according to the present invention, a coating solution for forming an electronic component material is made of a solution containing phosphotungstic acid and a film-forming aid, and the coating solution is coated on an inorganic or organic substrate and then subjected to a firing treatment. A method of manufacturing an electronic component material formed by the method is provided. The phosphotungstic acid used in the present invention is a general term for substances having a composition represented by the general formula xP ₂ O ₅ .yWO ₃ .nH ₂ O, but the _most well-known _is 24WO ₃ .nH ₂ O. This thing is
When applied onto a substrate, it is included in the solution at a concentration of about 1 to 30% by weight. In addition, the film forming aid used in the present invention is
Silicon compounds, titanium compounds, zirconium compounds, vanadium compounds, tantalum compounds, lanthanum compounds, lithium compounds, sodium compounds, potassium compounds, magnesium compounds, calcium compounds, aluminum compounds, boron compounds or phosphorus compounds that are soluble in the solvent used. Or synthetic resins. Examples of such are commercially available silanol solutions as silicon compounds, commercially available Aerosil, methoxysilane, ethoxysilane, butoxysilane, etc.
Titanium compounds include the reaction product of titanium tetrachloride and carboxylic acid, which is further reacted with alcohol, titanium ethylate, titanium isopropylate, titanium butyrate, etc. Zirconium compounds include zirconium ethylate, zirconium isopropylate, vanadium Compounds such as vanadium methylate, vanadium ethylate, vanadium butyrate, tantalum compounds such as tantalum ethylate, tantalum butyrate, etc.
Lanthanum compounds such as lanthanium isopropylate and lanthanium butyrate; lithium compounds such as lithium methylate, lithium ethylate, and lithium butyrate; sodium compounds such as sodium methylate, sodium ethylate, and sodium butyrate; and potassium compounds such as potassium. Methylate, potassium ethylate, potassium butyrate, etc. Magnesium compounds include magnesium methylate, magnesium ethylate, magnesium butyrate, etc. Calcium compounds include calcium ethylate, calcium propylate, etc. Aluminum compounds include alumina, aluminum ethylate, aluminum Boron compounds such as isopropylate and aluminum butyrate; boron compounds such as boron trioxide, boric acid, boron methylate, boron ethylate, and boron butyrate; phosphorus compounds such as phosphorus pentoxide, phosphorus trioxide, orthophosphoric acid, metaphosphoric acid, and Examples include phosphorus bromide, phosphorus pentachloride, phosphorus ethylate, and phosphorus butyrate. Examples of synthetic resins include polyvinyl acetate, polyacrylic ester, polymethacrylic ester, polyvinyl ether, polyvinylpyrrolidone, ethyl cellulose, nitrocellulose, shellac, phenolic resin, epoxy resin, polyamide resin, and polyurethane resin. These film-forming aids contribute approximately to the total solids content.
It is used in a proportion of 0.1 to 49% by weight. Next, as the inorganic or organic substrate constituting the material of the present invention, a glass plate, a metal plate, a ceramic plate, a plastic plate, a semiconductor plate, a transparent electrode, etc. are used. There is no particular limit to the size of this substrate, and it may be determined by considering only the issue of workability. The electronic component material of the present invention is manufactured by applying an electronic component material forming coating solution containing phosphotungstic acid and a film forming aid onto a predetermined substrate, drying it, and then firing it. Ru. The coating solution used in this case is prepared by dissolving the film forming aid in a suitable solvent, and then adding and dissolving phosphotungstic acid therein. Although this can be carried out at room temperature, heating to a temperature of up to 50° C. is advantageous to increase the rate of dissolution. This dissolution usually takes 2 to 30 minutes. After dissolution, the liquid temperature is cooled to room temperature, and a solvent is added as necessary. In this case, it is also possible to first dissolve the phosphotungstic acid and then add and dissolve the film forming aid. The solvent used to prepare this coating solution may be any solvent as long as it can dissolve each component and can be applied uniformly to the substrate surface during coating, including water, alcohols, esters, etc. ,
Ketones, polyhydric alcohols and their ethers,
β-diketones or mixtures thereof are preferred. Examples of alcohols include methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, and amyl alcohol. Examples of esters include methyl acetate, ethyl acetate, propyl acetate, and butyl acetate. Examples of ketones include acetone. , methyl ethyl ketone, methyl butyl ketone, and cyclohexanone, and examples of polyhydric alcohols and their ethers include ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol isopropyl ether, and ethylene glycol monobutyl ether. ,
Ethylene glycol dibutyl ether, propylene glycol, glycerin, etc. are used, and as the β-diketone, for example, acetylacetone is used. As a means of applying a coating solution to the substrate surface,
Any conventionally used application means can be used. Such methods include, for example, a spinner method, a spray method, a brush coating method, a dipping method,
Examples include a roll coating method, a flow coating method, a curtain coating method, and a screen printing method. After applying the coating solution onto the substrate in this way, it is dried and then subjected to a baking process.
This is done by heating to a temperature of 150-1200°C. This temperature must be selected within a temperature range that does not lead to undesirable conditions such as melting, softening, or decomposition of the substrate. The longer the baking time, the better, but considering workability, it is usually 5 to 60 minutes.
Selected within minutes. Although there are no particular restrictions on the atmosphere, firing is usually performed in air or oxygen. By baking in this manner, a uniform continuous film with a thickness of several hundred angstroms to several micrometers is formed on the substrate. The substrate with the continuous film obtained in this way is
Suitable for use as a material for various electronic components. For example, when a semiconductor such as a silicon single crystal is used as a substrate, the film serves as a source of impurities for diffusion to form an N type, and can also be used as a passivation or insulating film. Further, when a liquid crystal display is used as a substrate, the film becomes an effective alignment film. Furthermore, if the substrate is a transparent electrode formed on a glass substrate, it can be an electrochromic material. Next, the present invention will be explained in more detail with reference to Examples. Example 1 10g of phosphotungstic acid, _SiO2 equivalent concentration 10
% silanol solution (manufactured by Tokyo Ohka Kogyo Co., Ltd., trade name "OCD") and stirred for 15 minutes at room temperature to dissolve. Next, 20 g of methyl alcohol is added to this solution to prepare a coating solution. The coating solution thus obtained is dropped onto a smooth sodium glass plate with a thickness of 1.7 mm, coated with a spinner for 15 seconds, and baked in air at 400° C. for 30 minutes. The properties of the material thus obtained are shown below.

[Table] The transmittance of the raw glass was 91%. Example 2 5 g of phosphotungstic acid and 10 g of ethyl alcohol
g and stir for 5 minutes at room temperature to dissolve. Add 50 g of silanol solution with a SiO ₂ equivalent concentration of 8.5% to this solution.
and 1 g of phosphorus pentoxide to prepare a coating solution. Next, a transparent conductive film is formed with a thickness of 0.7
After dropping the above coating solution onto a glass substrate of mm size and applying it using a spinner at 2000 rpm for 10 seconds,
This substrate is baked at 300°C for 30 minutes in an oxygen atmosphere (film thickness is 3500 Å). Next, add 10 parts by weight of glycerin and 1 part of sulfuric acid to a beaker.
Mix parts by weight, and place the above substrate and a stainless steel plate as a counter electrode therein. When a negative voltage of 2.0 V was applied to the transparent conductive film side, a blue color developed, and when a positive voltage was applied, the color disappeared. Example 3 15g of phosphotungstic acid at a TiO ₂ equivalent concentration of 12%
Dissolve in 80 g of hydroxytitanium alcohol solution (Titanium Film, manufactured by Tokyo Ohka) by stirring at 30°C for 20 minutes. Add 20g of ethylene glycol monoethyl ether to this solution to make a coating solution.
It is applied by dipping onto smooth sodium glass with a thickness of 1.1 mm and fired at 200°C for 60 minutes in air. The properties thus obtained are as follows.

[Table] The transmittance of the raw glass was 92%. Example 4 10 g of phosphotungstic acid is dissolved in 10 g of acetone by stirring at room temperature for 10 minutes. Add 50g of 15% polyvinyl butyral ethyl alcohol solution to this solution.
and 30 g of ethylene glycol monomethyl ether to prepare a coating solution. A smooth stainless steel plate with a thickness of 1.5 mm was immersed in this coating solution, pulled up at a pulling speed of 25 cm/min, and coated at 200°C in air.
Baked for 60 minutes. The film thickness thus obtained was approximately 5000 Å, and the resistance value was 10 ¹⁴ Ωcm or more. Example 5 8 g of phosphotungstic acid at a SiO ₂ equivalent concentration of 6.1%
Dissolve in 80 g of silanol solution (manufactured by Tokyo Ohka, Silica Film) by stirring for 20 minutes at room temperature. 5 g of n-butyl alcohol and 5 g of butyl acetate are added to this solution to prepare a coating solution. This coating solution was applied onto a silicon thin plate using a spinner at 4000 rpm for 20 seconds, and then heated at 300°C for 30 minutes and further heated at 1100°C (dry N ₂ 2
/min) for 30 minutes to diffuse, the diffusion depth was 1.0μ, and the surface resistivity was 60Ω/□. Example 6 10 g of phosphotungstic acid and 60 g of ethyl alcohol
Stir and dissolve in g at 30℃ for 10 minutes. 6 g of tantalum butyrate, 0.5 g of phosphorus pentoxide, and 2 g of acetylacetone are added to this solution to prepare a coating solution. This coating solution is applied onto a glass substrate on which a transparent conductive film is formed by dipping at a rate of 30 cm/min. Then about
It was fired at a temperature of 200°C to obtain a film thickness of 2000 Å. This coating layer is rubbed in a certain direction using cotton cloth,
A device was constructed using nematic liquid crystal and a display operation test was performed, which showed good twisted nematic orientation.

Claims (1)

[Claims] 1. A coating solution for forming an electronic component material containing phosphotungstic acid and a film forming aid. 2. A method for producing an electronic component material, which comprises applying a coating solution for forming an electronic component material containing phosphotungstic acid and a film-forming aid onto an inorganic or organic substrate, and then firing the substrate.