Coating liquid for forming film and substrate with film applied thereto

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical Field of Invention]

The present invention relates to a coating liquid for forming a film and a base material with a coating, and more particularly, a coating liquid capable of forming a titanium oxide-based coating having a high refractive index or a titanium oxide-based coating having a high conductivity on a base material and the coating liquid thereof. The present invention relates to a coated base material in which such a titanium oxide-based coating is formed on the base material.

【0002】

[Technical Background of the Invention]

Conventionally, as a method of forming a titanium oxide-based coating on a base material, 1) A solution of titanium alkoxide in an organic solvent such as alcohol is used as a coating liquid, and this coating liquid is applied to the surface of a substrate to form a coating film, and the titanium alkoxide contained in this coating film is low. A method of heating after hydrolysis in a humid atmosphere, or 2) A method in which a coating film is formed on a substrate as described above, and then the titanium alkoxide in the coating film is directly heated to a high temperature for thermal decomposition. Etc. are known.

【0003】

However, when the titanium oxide-based film is formed on the base material by the method 1) above, the hydrolysis of the titanium alkoxide becomes faster unless the number of carbon atoms of the alkyl group contained in the titanium alkoxide is large to some extent. As a result, there is a problem that the film formed on the base material becomes non-uniform.

【0004】

Further, when the titanium oxide-based coating is formed on the base material by the method 1) above, there is a problem that the alkyl group in the titanium alkoxide remains in the coating formed on the base material.

【0005】

Further, in the thermal decomposition method of 2) above, it is difficult to thicken the film formed on the base material, and voids and the like are generated due to the decomposition of the alkyl group contained in the titanium alkoxide. Therefore, there is a problem that a dense film cannot be formed on the base material.

【0006】

By the way, regarding peroxotitanic acid, it has been conventionally practiced in the field of analytical chemistry that peroxotitanic acid is produced by directly reacting an inorganic acid salt such as titanium sulfate or titanium tetrachloride or a titanium alkoxide with a hydrogen peroxide solution. Is known for. Further, Japanese Patent Application Laid-Open No. 62-252319 describes a method for producing peroxotitanic acid by directly reacting alkoxide titanium or titanium hydride with hydrogen peroxide solution.

【0007】

However, the peroxotitanic acid produced by these methods is a monomer and has a problem that it is stable only at an extremely dilute concentration and cannot exist in a stable state for a long period of time.

【0008】

Further, when peroxotitanic acid produced by these methods is dissolved in water to produce a coating liquid and a film is formed on the substrate with the obtained coating liquid, water as a solvent evaporates to form a film. At the initial stage, peroxotitanic acid changes to a gel state. This gel contains a large amount of solvent, and there is a problem that the film formed on the substrate shrinks in the process of reducing the amount of this solvent, and cracks and peeling are likely to occur.

【0009】

Further, when the film formed on the substrate in this way is fired at a high temperature, the film after firing tends to be porous, and the porous film thus obtained is inferior in strength and adhesion. There was a point.

【0010】

[Purpose of Invention]

The present invention has been made in view of the above circumstances, and is a coating liquid capable of forming a titanium oxide-based coating having a high refractive index or a titanium oxide-based coating having a high conductivity on a substrate, and such a titanium oxide-based coating. It is an object of the present invention to provide a coated base material in which a coating film is formed on the base material.

【0011】

[Summary of Invention]

The coating liquid for film formation according to the present invention is characterized by containing peroxopolytitanic acid as a film forming component in a state of being dissolved in water and / or an organic solvent.

【0012】

In this case, it is preferable that the coating liquid is further contained in a state in which peroxopolytitanic acid containing a metal other than Ti is dissolved. Further, it is preferable that the coating liquid further contains the inorganic compound fine particles in a dispersed state.

【0013】

Further, the base material with a coating according to the present invention is characterized in that it has a coating film formed by using the coating liquid for forming a coating film as described above on the base material.

【0014】

[Specific Description of the Invention]

Hereinafter, the coating liquid for forming a film according to the present invention will be specifically described. Coating liquid for film formation The coating liquid for film formation according to the present invention contains peroxopolytitanic acid as a film forming component.

【0015】

In the present invention, the peroxopolytitanic acid is an oxide of titanium having a peroxo bond (-OO-), and means a polymer of peroxotitanic acid. The peroxopolytitanic acid used in the present invention has a degree of polymerization such that the average particle size measured by the laser Doppler method is 1 to 50 nm.

【0016】

Since the peroxopolytitanic acid used in the present invention has a peroxo group coordinated with titanium, it shows a crystal structure similar to anatase crystal when analyzed by X-ray diffraction method. When this is calcined, the peroxo group is eliminated and transformed into anatase crystals.

【0017】

In the present invention, peroxopolytitanic acid produced by the following method is used. a) A method for producing peroxopolytitanic acid by reacting titanium hydroxide or titanium oxide hydrate with hydrogen peroxide, or b) Titanium metal or titanium carbide and H₂O₂A method for producing peroxopolytitanic acid by reacting.

【0018】

The above method a) will be described in more detail as follows. A gel or sol of titanium oxide hydrate is prepared by a conventionally known method, for example, a method of hydrolyzing an inorganic titanium compound such as titanium chloride or titanium sulfate or a hydrolyzable organic titanium compound such as titanium alkoxide. The titanium oxide hydrate referred to here includes titanium hydroxide and titanium acid.

【0019】

Then, hydrogen peroxide is added to the dispersion liquid, sol or mixed dispersion liquid of these gels, and the solution is obtained at room temperature or at 90 ° C. or lower to obtain a solution of peroxotitanic acid.

【0020】

Titanium oxide hydrate TiO used as a raw material in the production of peroxotitanic acid₂The concentration is preferably about 10% by weight or less, preferably 5% by weight or less. Also hydrogen peroxide and titanium oxide hydrate (TiO₂Quantity ratio (H) to conversion amount)₂O₂/ TiO₂) Is preferably 1 to 10 (mol / mol), preferably 3 to 10 (mol / mol). If the amount ratio is less than 1 mol / mol, unreactant may remain, and if it exceeds 10 mol / mol, excess H₂O₂Is not desirable because it will remain.

【0021】

The peroxopolytitanic acid used in the present invention may contain a metal element other than Ti. Such a peroxopolytitanic acid containing a metal element other than Ti can be obtained, for example, as follows.

【0022】

Prepare a mixed gel or coprecipitated gel of titanium oxide hydrate and a hydrate of a metal oxide other than Ti, or a sol thereof. The method for preparing these gels or sol is not particularly limited, and for example, gels obtained by hydrolyzing each inorganic salt or alkoxide may be mixed, or a mixed aqueous solution of each salt may be hydrolyzed. , These gels or sol are prepared by a conventionally known method.

【0023】

As for the hydrate of the metal oxide other than Ti when preparing the gel or sol, the metal oxide other than Ti is TiO in peroxopolytitanium acid.₂It is mixed with titanium oxide hydrate so that it is contained in an amount of 1/200 to 1/1 (wt / wt), preferably 1/20 to 1/1 (wt / wt).

【0024】

Peroxopolytitanic acid containing a metal element other than the target Ti can be obtained by adding hydrogen peroxide to the dispersion liquid of the mixed gel or coprecipitation gel obtained as described above, or by adding hydrogen peroxide to these sols and heating them. Be done.

【0025】

Heating temperature for producing peroxopolytitanic acid containing metal elements other than Ti, H₂O₂/ TiO₂Conditions such as the molar ratio are the same as in the case of producing peroxopolytitanic acid containing no metal element other than Ti.

【0026】

In the peroxopolytitanic acid containing a metal element other than Ti thus obtained, the metal element other than Ti is present in the crystal of peroxopolytitanic acid in a so-called doped state, that is, in a state of being incorporated. The fact that a metal element other than Ti exists in a doped state means that the absorption spectrum of M-OH is that of Ti-OH when the infrared absorption spectrum of peroxopolytitanic acid containing the metal element M other than Ti is measured. It is confirmed by overlapping with the absorption spectrum.

【0027】

The coating liquid according to the present invention is obtained by dissolving the peroxopolytitanic acid obtained as described above in water and / or an organic solvent. The concentration of peroxopolytitanic acid in the coating liquid is TiO₂The converted amount is preferably 10% by weight or less.

【0028】

As the organic solvent, a solvent capable of dissolving peroxopolytitanic acid alone or in a mixed state with water is used, and specifically, methanol, ethanol, 1,2-butanol, iso-propyl alcohol, etc. Alcohols such as n-propyl alcohol, n-butanol, cyclohexanol, allyl alcohol, glycerin, diethyl ether, dipropyl alcohol, dioxane, trioxane, 2-methylfuran, tetrahydrofuran, tetrahydropyran, diethylene glycol dimethyl ether, crown ether and other ethers. , Acetals, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, cellosolves such as furfuryl alcohol, acetone, methyl ethyl ketone, 2-pentanone, 4-heptanone, methyl isobutyl ketone, isophorone, cyclohexanone. , Ketones such as methylcyclohexanone, esters such as methyl acetate, ethyl acetate, propyl acetate, γ-butyrolactone, dibutyl tartrate, ethylene glycol monoacetate, acetonitrile, pyrrol, α-picolin, β-picolin, quinoline, aniline, ethylenediamine , Methylamine, triethylamine, formamide, N-methylpyrrolidone, ε-caprolactam and other nitrogen-containing organic solvents and the like. These organic solvents are used alone or in a mixed state of two or more kinds.

【0029】

The coating liquid according to the present invention may contain fine particles of an inorganic compound in addition to the peroxopolytitanic acid component as described above. Specific examples of the inorganic compound fine particles to be blended in the coating liquid according to the present invention include inorganic oxide fine particles such as silica, titania, zirconia, alumina, ceria, tungsten oxide, tin oxide, antimony oxide, and iron oxide. Fluoride fine particles such as magnesium fluoride, calcium fluoride, and calcium fluoride fluoride can be mentioned. The inorganic compound fine particles may be fine particles composed of one of these inorganic compounds, or may be composite compound fine particles composed of two or more of these inorganic compounds.

【0030】

In the present invention, the size and type of the fine particles of the inorganic compound to be blended in the coating liquid are selected according to the function of the coating film formed on the base material, and one or more kinds of inorganic compound fine particles are used in the coating liquid. It is blended inside.

【0031】

For example, from a coating liquid containing silica fine particles as inorganic compound fine particles, a film having fine irregularities can be formed on the base material, and the surface reflection of the base material can be prevented by the fine irregularities. Further, from a coating liquid containing conductive inorganic oxide fine particles such as antimony, fluorine-doped tin oxide, tin-doped indium oxide (ITO), and antimony oxide as inorganic compound fine particles, the substrate is conductive. A sex film can be formed.

【0032】

The refractive index of the coating film formed on the substrate can be adjusted by the type of the inorganic compound fine particles contained in the coating liquid and the combination of two or more types. For example, ceria, iron oxide, etc. are used as the inorganic compound fine particles. When used, a transparent film having a high refractive index can be obtained, and when magnesium fluoride, calcium fluoride or the like is used, a film having a low refractive index and a low surface reflectance can be obtained.

【0033】

Further, it is obtained by subjecting the composite oxide fine particles as described in Japanese Patent Application No. 4-91650, which the applicant has previously filed, with acid treatment to dissolve and remove a part of metal elements other than silica. Even if the porous composite oxide fine particles are used as the inorganic compound fine particles, a film having low surface reflectance can be obtained.

【0034】

These fine particles are usually added in the form of powder or sol, and the amount thereof is peroxopolytitanic acid (TiO).₂Conversion) 0.5 to 10 parts by weight, preferably 1 to 8 parts by weight, per 1 part by weight.

【0035】

As described above, the coating liquid for forming a film according to the present invention can be obtained. The coating liquid according to the present invention is not particularly limited as long as it contains peroxopolytitanic acid dissolved in water and / or an organic solvent as a matrix component, and is synthesized as necessary in addition to the above-mentioned inorganic compound fine particles. It may contain any colorant such as resin fine particles, organic pigments, and dyes.

【0036】

Coating base material Next, the coated base material according to the present invention will be specifically described. In the coated base material according to the present invention, the coating liquid obtained as described above is applied onto a base material such as glass, plastic, metal, ceramics, or semiconductor by a coating method such as a spinner method to form a coating film. It is obtained by drying the coating film and then firing it if necessary.

【0037】

The heating temperature of the coating film required for firing the above coating film may be about 150 to 200 ° C, and a dense coating film that can sufficiently withstand practical use on the substrate simply by firing the coating film at such a low temperature. Is formed.

【0038】

The coating film formed on the substrate from the coating liquid according to the present invention containing only peroxopolytitanic acid as described above is usually about 10.⁹~10¹⁴It has a surface resistance of Ω / , and is therefore suitable as a conductive coating for antistatic purposes.

【0039】

Further, this coating film is TiO formed on the base material by the conventional method.₂It has a high refractive index of 1.9 to 2.0, similar to the coating. Further, this film has a feature that it can be thickened by 1 μm or more because the shrinkage at the time of film formation is small.

【0040】

By containing a metal element other than Ti in the peroxopolytitanic acid, the surface resistance value and the refractive index of the coating film can be changed according to the type and the amount of the metal element.

【0041】

For example, when the peroxopolytitanic acid contains a metal element other than Ti such as Zr, Ce, Si, Fe, Cu, Sn, Nb, etc., the surface resistance value of the coating film is 10.⁷~10¹³It changes in the range of Ω / . When the peroxopolytitanic acid contains Ce, Sn, Zr, and W, respectively, the refractive index of the coating film is 1.7 to 1.9 (in the case of containing Ce), 1.8, depending on the amount of doping of each metal element. It changes from ~ 2.0 (when Sn is contained), 2.0 to 2.1 (when Zn is contained), and 2.1 to 2.2 (when W is contained).

【0042】

Further, when the inorganic compound fine particles are contained in the coating film, various functions are imparted to the coating film according to the type and amount of the inorganic compound fine particles. For example, a highly conductive film can be obtained by containing conductive fine particles in the film. Since the coating has high conductivity as described above, this coating is formed on the substrate by using a conventional coating liquid for forming a conductive coating containing an insulating coating forming component and conductive fine particles. It is possible to exhibit the same degree of conductivity by containing a small amount of conductive particles as compared with the conductive film.

【0043】

Therefore, according to the present invention, the amount of conductive fine particles in the coating can be reduced, so that a substrate with a conductive coating having better mechanical strength and adhesion than the conventional one can be obtained. Further, the film formed on the substrate from the coating liquid according to the present invention containing metal colloidal particles such as Ag, Pd, and Ni in addition to peroxopolytitanic acid becomes a low-resistance conductive film, for example, the above-mentioned metal colloidal particle. When the particles are Ag colloidal particles, the film formed on the substrate from the coating liquid according to the present invention becomes a translucent film having a high refractive index, so that it can also be used as a half mirror.

【0044】

When the metal colloid particles are black Ni or Cr metal colloid particles, the coating film formed on the substrate from the coating liquid according to the present invention is suitable as a black mask or black stripe for a color filter.

【0045】

[Effect of the invention]

The coating liquid for film formation according to the present invention has excellent storage stability and is TiO.₂Even at a high concentration of about 10% by weight in terms of conversion amount, the viscosity does not increase for several months, and it is highly compatible with hydrophilic organic solvents such as alcohol.

【0046】

According to the present invention, a conductive film is formed on a base material from a coating solution for forming a film containing only peroxopolytitaic acid. Therefore, when conductive fine particles are contained in the conductive film, conventional coating solutions are used. The intergranular resistance between the conductive particles is smaller than that of the conductive film formed on the substrate from the coating liquid for forming the conductive film containing the insulating matrix component, for example, the silica-based matrix component and the conductive fine particles. Therefore, there is a feature that a low resistance film can be obtained.

【0047】

Further, since the peroxopolytitanic acid contained in the coating liquid for film formation according to the present invention undergoes elimination of the peroxo group at a low temperature of 200 ° C. or lower, according to the present invention, it is extremely dense and strong at a relatively low temperature. It has the advantage that a fine film can be formed on the base material.

【0048】

Further, since the peroxopolytitanic acid is easily desorbed from the peroxo group by ultraviolet rays, electron beams, etc., the coating film-forming coating solution according to the present invention is suitable as an inorganic resist film-forming coating solution.

【0049】

Furthermore, since this peroxopolytitanic acid releases active oxygen when the peroxo group is eliminated (decomposed), there is also a feature that a bactericidal film is formed on the substrate according to the present invention.

【0050】

In addition, according to the present invention, when a metal cluster is contained in the coating film, a coated substrate having a photocatalytic function can be obtained.

【0051】

[Example]

Hereinafter, the present invention will be described with reference to Examples, but the present invention is not limited to these Examples.

【0052】

[Example 1]

Titanium tetrachloride aqueous solution (TiCl₄Titanium oxide concentration 28% by weight) 160g was diluted with 2000g of pure water. 230 g of 15% aqueous ammonia was added to this solution to neutralize it, and the mixture was hydrolyzed to form a gel. After washing this gel, it is suspended in pure water again and TiO₂1500 g of a slurry having a concentration of 2% by weight was prepared. 340 g of hydrogen peroxide solution (35% concentration) was added to this slurry, and the mixture was heated at 80 ° C. for 1 hour to obtain a transparent yellow peroxopolytitanic acid aqueous solution. The average particle size of peroxopolytitanic acid in this aqueous solution was 2.5 nm when measured with a laser Doppler particle size measuring instrument (NIOMP). In addition, when the infrared absorption spectrum of the yellow powder obtained by freeze-drying this solution was measured, a strong peak indicating that the peroxo group was coordinated to the titanium metal was 900 cm.^-1Appeared in the vicinity. In addition, X-ray diffraction of this freeze-dried product showed anatase-like crystals.

【0053】

A coating solution was prepared by adding 50 g of methanol to 50 g of the peroxopolytitanic acid aqueous solution obtained as described above. The obtained coating liquid was applied to glass by a spinner method (200 rpm), dried at 100 ° C for 10 minutes, and then heat-treated at 200 ° C for 30 minutes. When the surface resistance of the coating film formed on the glass substrate in this way is measured with a high resistance meter (Hiresta; manufactured by Mitsubishi Yuka), it is 9 × 10.⁹It was Ω / . The refractive index of the film was measured using an ellipsometer and found to be 1.9.

【0054】

The above results are shown in Table 1.

【0055】

[Example 2]

Zirconium oxychloride (ZrCl)₂O 8H₂O) 32g is dissolved in 1000g of pure water, and an aqueous solution of titanium tetrachloride (manufactured by Sumitomo Sticks; TiO)₂Concentration 28%) Mixed with 393 g.

【0056】

The hydroxide gel produced by adding 600 g of 15% ammonia water to this mixed solution was washed. A slurry was prepared by adding 80 g of pure water to 20 g of the washed gel (solid content weight 10%). To 100 g of the obtained slurry, 10 g of hydrogen peroxide (35%) was added and heated at 80 ° C. for 1 hour to prepare a zirconium-doped peroxopolytitanic acid aqueous solution.

【0057】

A coating solution was prepared by mixing 50 g of this peroxopolytitanic acid aqueous solution and 50 g of methanol. This coating solution was applied to glass by the spinner method (150 rpm), dried at 100 ° C for 10 minutes, and then fired at 200 ° C for 30 minutes.

【0058】

Table 1 shows the surface resistance and refractive index of the coating film thus formed on the glass substrate.

【0059】

[Example 3]

Stannous tetrachloride (SnCl)₄) 26g of titanium tetrachloride aqueous solution (manufactured by Sumitomo Sticks; TiO₂Concentration 28%) Mixed to 482 g.

【0060】

1165 g of pure water was added to this mixed solution to dilute it. 690 g of 15% aqueous ammonia was added to this diluted solution to form a hydroxide gel. After washing this hydroxide gel, 500 g of pure water was added to 100 g of this gel (solid content concentration 12% by weight) to prepare a slurry. To 100 g of the obtained slurry, 10 g of hydrogen peroxide (35%) was added, and the mixture was heated at 80 ° C. for 1 hour to prepare a tin-doped peroxopolytitanic acid.

【0061】

A coating solution was prepared by adding 50 g of methanol to 50 g of the tin-doped peroxopolytitanic acid aqueous solution thus obtained. The obtained coating liquid was applied to glass by the spinner method (150 rpm), dried at 100 ° C for 10 minutes, and then fired at 200 ° C for 30 minutes.

【0062】

Table 1 shows the surface resistance and refractive index of the coating film thus formed on the glass substrate.

【0063】

[Example 4]

Sodium tungstate (Na₂WO₃ 2H₂O) 100 g of an aqueous solution prepared by dissolving 33 g of 33 g of pure water in 267 g of pure water and 1285 g of the peroxopolytitanic acid aqueous solution (2% by weight) prepared in Example 1 were mixed. 30 cc of cation exchange resin was added to this mixed solution to adjust the pH to 4.2. Then, 15% aqueous ammonia was added again to raise the pH to 8 again. This solution was heat treated at 80 ° C. for 1 hour to give a tungsten-doped peroxopolytitanic acid.

【0064】

50 g of methanol and 50 g of ethanol were mixed with 100 g of peroxopolytitanic acid doped with tungsten thus obtained to prepare a coating solution. The obtained coating liquid was applied to glass by a spinner method (10 rpm), dried at 100 ° C for 10 minutes, and then heat-treated at 150 ° C for 30 minutes.

【0065】

Table 1 shows the surface resistance and refractive index of the coating film thus formed on the glass substrate.

【0066】

[Example 5]

Cerium ammonium nitrate ((NH)₄)₂Ce (NO₃)₆) 55 g was mixed with 100 g of an aqueous solution prepared in 445 g of pure water and 1530 g of the peroxopolytitanic acid aqueous solution prepared in Example 1. 120 cc of anion exchange resin was added to this mixed solution to adjust the pH to 9.3. This solution was heated at 80 ° C. for 2 hours to obtain a cerium-doped peroxopolytitanic acid aqueous solution. A coating solution was prepared by mixing 25 g of methanol and 25 g of isopropyl alcohol with 50 g of the obtained peroxopolytitanic acid aqueous solution.

【0067】

The obtained coating liquid was applied to glass by a spinner method (200 rpm), dried at 100 ° C. for 10 minutes, and then irradiated with UV having a light intensity of 300 mJ. Then it was fired at 150 ° C for 1 hour.

【0068】

Table 1 shows the surface resistance and refractive index of the coating film thus formed on the glass substrate.

【0069】

[Example 6]

1 g of titanium carbide (TiC; made by Shin-Nippon Metal) and 0.3 g of zirconium carbide (ZrC; made by Shin-Nippon Metal) were suspended in 200 g of 10% hydrogen peroxide solution and heated at 70 ° C. In this way, a peroxopolytitanic acid aqueous solution doped with green-yellow transparent zirconium was obtained.

【0070】

A coating solution was prepared by mixing 25 g of isopropyl alcohol and 25 g of ethanol with 50 g of the zirconium-doped peroxopolytitanic acid aqueous solution. The obtained coating liquid was applied onto a PES film using a bar coater, dried at 100 ° C for .0 minutes, and then heat-treated at 200 ° C for 30 minutes.

【0071】

Table 1 shows the surface resistance and refractive index of the film formed on the PES film in this way.

【0072】

[Example 7]

Isopropoxide Titanium [Ti (OC)₃H₇)₄] 320g and aluminum-tri-sec-butoxide [(C₄H₉O)₃25 g of Al] was dissolved in 900 g of isopropyl alcohol.

【0073】

90 g of pure water was added to the solution to hydrolyze the mixed metal alkoxide. After washing the gel thus obtained, 200 g of this gel (solid content concentration 5%) was redispersed in 800 g of pure water to form a slurry. To 1000 g of the obtained slurry, 115 g of hydrogen peroxide solution (35%) was added and heated at 80 ° C. for 1 hour to obtain an aluminum-doped peroxopolytitanic acid aqueous solution. 25 g of methanol and 25 g of isopropyl alcohol were mixed with 50 g of this solution and subjected to ultrasonic treatment to prepare a coating solution.

【0074】

The obtained coating liquid was applied onto a polyimide film using a bar coater, dried at 110 ° C for 10 minutes, and then calcined at 200 ° C for 30 minutes. Table 1 shows the surface resistance and refractive index of the film formed on the polyimide film in this way.

【0075】

[Example 8]

Tin chloride (SnCl)₄) 260g, Antimony trichloride (SbCl)₃) 1300 g of 15% aqueous ammonia was added to an aqueous solution prepared by dissolving 23 g in 3000 g of dilute hydrochloric acid (5% by weight), and a mixture of tin chloride and antimony trichloride was hydrolyzed to form a gel.

【0076】

The gel was washed and then dried at 110 ° C. overnight. Then, it was calcined at 650 ° C. for 2 hours under air flow to obtain a conductive tin oxide fine powder doped with Sb. The volume resistance value of this conductive powder was 0.1 Ω · cm. 20 g of the slurry (solid content concentration 10% by weight, average particle size 0.3 μm) after crushing this powder with a wet sand mill, 20 g of the peroxopolytitanic acid aqueous solution (2% by weight) prepared in Example 1 and 50 g of methanol were added. Was mixed and the powder was sufficiently dispersed by sonication to prepare a coating liquid.

【0077】

This coating liquid was applied to glass by the spinner method (150 rpm), dried at 100 ° C for 10 minutes, and then fired at 200 ° C for 30 minutes. Table 1 shows the surface resistance and refractive index of the coating film thus formed on the glass substrate.

【0078】

[Example 9]

Indium nitrate (In (NO)₃)₃ 3H₂O) 350g and stannous chloride (SnCl)₂ 2H₂O) 750 g of 15% ammonia water was added to an aqueous solution of 23 g of pure water dissolved in 4000 g of pure water, and indium nitrate and stannous chloride were hydrolyzed to form a hydroxide gel. The gel was washed and then dried at 110 ° C. overnight. Then at 650 ° C for 2 hours N₂Firing in an atmosphere gave a Sn-doped conductive indium oxide fine powder.

【0079】

The volume resistance value of this conductive powder is 2 × 10.^-2It was Ω · cm. 20 g of the peroxopolytitanic acid aqueous solution prepared in Example 1 and 50 g of methanol are mixed with 30 g of a slurry (solid content concentration 10% by weight, average particle size 0.17 μm) after crushing 100 g of this powder with a wet sand mill, and sonicated. It was treated and a coating solution was prepared.

【0080】

This coating liquid was applied to glass by a spinner method (100 rpm), dried at 100 ° C for 10 minutes, and then fired at 200 ° C for 30 minutes. Table 1 shows the surface resistance and refractive index of the coating film thus formed on the glass substrate.

【0081】

[Example 10]

4 g of silica sol with an average particle size of 18 nm (manufactured by Catalysis Chemical Industry Co., Ltd., OSCAL-1133, silica concentration 30% by weight) monodispersed in methanol is mixed with 30 g of the peroxopolytitanic acid aqueous solution prepared in Example 1 and 30 g of methanol. A coating solution was prepared.

【0082】

This coating liquid was applied to glass by a spinner method (100 rpm), dried at 100 ° C for 10 minutes, and then heat-treated at 200 ° C for 30 minutes. Table 1 shows the surface resistance and refractive index of the coating film thus formed on the glass substrate.

【0083】

[Example 11]

100 g of titanium black (manufactured by Mitsubishi Materials) was mixed with 900 g of pure water and pulverized with a ball mill for 3 hours. The average particle size of the particles in the slurry thus obtained was measured with a centrifugal sedimentation type particle size distribution measuring instrument (manufactured by HORIBA, Ltd .; Capa-500) and found to be 0.36 μm.

【0084】

The coating liquid was prepared by mixing 20 g of the titanium black slurry after this pulverization treatment, 50 g of the peroxopolytitanic acid aqueous solution prepared in Example 1, and 70 g of methanol.

【0085】

This coating liquid was applied to glass by a spinner method (50 rpm), dried at 100 ° C for 10 minutes, and then heat-treated at 200 ° C for 30 minutes. Table 1 shows the surface resistance and refractive index of the coating film thus formed on the glass substrate.

【0086】

[table 1]

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