JP2000271491A - Photocatalytic membrane and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocatalytic membrane exhibiting excellent defogging and durability and excellent in productivity, the producing method, a stain resistant defogging material and a coating material forming the same. SOLUTION: The photocatalytic membrane has a photocatalytic layer containing titania and a transition element. The activating wavelength is 380-420 nm. The photocatalytic membrane contains 45-95 pts.wt. titania, 5-55 pts.wt. silica and 10-2-10-8 mol transition metal per 1g titania. A hydrophilicity maintaining layer containing silica, alumina, titania and the like and having <=50 nm thickness can be laminated on the photocatalytic layer. The stain resistant defogging material is formed by covering base material such as a glass plate with the photocatalytic layer. The coating material is the coating material for forming the photocatalytic membrane and contains titania fine particle and/or a titania precursor, silica fine particle and/or a silica precursor and the transition element compound. The producing method of the photocatalytic membrane is by imparting a desired membrane shape to the coating material and heating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photocatalytic film and a method for producing the same, and more particularly, to a photocatalytic film applied to a surface of a glass, a mirror or the like, which is excellent in stain resistance and abrasion resistance and has a long antifogging property. The present invention relates to a photocatalyst film, a stain-resistant antifogging material, a coating material for forming the same and a method for producing the photocatalyst film.

[0002]

2. Description of the Related Art Conventionally, inorganic glass and the like have been widely used in articles such as window glasses, mirror surfaces, and spectacle lenses by utilizing the properties of a transparent substrate. However, the disadvantages of articles using these transparent substrates are that when used in places of high temperature and high humidity or interfaces with a large temperature difference, dew condensation occurs on the surface of the articles,
As a result, the surface of the article becomes cloudy. In particular, among window substrates, spectacle lenses, mirrors and the like among transparent substrates, it is a serious problem that the surface of the article is easily fogged or scratched. Therefore, improvement of these problems has been desired from various aspects, and various attempts have been made to impart anti-fog properties and durability to various articles such as transparent substrates. I have.

As a method for preventing such fogging on the surface of a substrate, a method of forming a hydrophilic film on a surface of glass or the like has been performed. It has long been known that fogging can be prevented by applying a surfactant to the surface as the simplest method.
In Japanese Patent Laid-Open Publication No. H10-163, it has been proposed that a water-soluble polymer such as polyacrylic acid or polyvinyl alcohol is blended with a surfactant to improve the durability of the anti-fogging effect. However, such a method can only temporarily provide the anti-fogging property, so that a continuous effect cannot be expected.

Further, Japanese Patent Application Laid-Open No. 55-154351 discloses
Molybdenum oxide and tungsten
One or more of phosphorous oxides and phosphorus oxides.
Film formed by physical vapor deposition, chemical vapor deposition, etc.
A method for obtaining a conductive thin film has been proposed.
No. 5210 states that P₂P on glass containing O₂O ₅
To impart hydrophilicity by contacting liquid or vapor
JP-A-53-58492 discloses a sulfonic acid type amphoteric field.
A composition comprising a surfactant and an inorganic or acetate salt is added to a lower grade
Adhesion is achieved by applying to the substrate using
A method for forming a hydrophilic film having excellent properties has been proposed.
However, even with a hydrophilic film obtained by either method,
It is difficult to obtain anti-fog properties with excellent long-term durability.
Was.

Further, a method of using titania as a photocatalyst has been proposed, but it can be sufficiently used in an environment such as outdoors where ultraviolet rays are abundant.
These photocatalysts cannot exhibit sufficient activity when used in an environment with a small amount of ultraviolet light of m or less.
Japanese Patent Application Laid-Open No. 9-262482 discloses that the surface of a titania film has Cr, V, Cu, Fe, Mg, Ag, Pd, N
A method has been proposed in which metal ions selected from i, Mn, and Pt are ion-implanted using an accelerator to exhibit catalytic activity even in a long wavelength region of 400 nm or more. However, this method is difficult to mass-produce industrially. is there.

As described above, in the prior art, there is a problem that a photocatalyst film which can be used in an environment with a small amount of ultraviolet light, such as a vehicle cabin, and has excellent productivity, and a method for producing the same have not been realized. Was. The present invention has been made in view of the problems of the related art, and even under an environment with a small amount of ultraviolet light, exhibits excellent antifogging property and durability, and has excellent photocatalytic film and productivity. An object of the present invention is to provide a method for producing the same, a stain-resistant antifogging material, and a coating material for forming the same.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, mixed a transition element into a photocatalyst film in which titania or silica is dispersed,
By adding and dispersing a transition element compound in a solution containing titania fine particles and a titania precursor, by coating and heating on a substrate, the inventors have found that the above-mentioned problems can be solved, and have completed the present invention. .

That is, the photocatalyst film of the present invention has a photocatalyst layer containing titania and a transition element, and has a catalytic active wavelength range of 380 to 420 nm.

A preferred mode of the photocatalyst film of the present invention is that the photocatalytic layer has a hydrophilic maintenance layer having a thickness of 50 nm or less containing at least one selected from the group consisting of silica, alumina and titania on the photocatalyst layer. Are laminated.

Further, the stain-resistant antifogging material of the present invention is characterized in that the photocatalytic film as described above is coated on a substrate.

In a preferred embodiment of the antifouling antifogging material of the present invention, a silica and / or alumina based metal oxide layer is inserted between the substrate and the photocatalytic film. I do.

Further, the coating material for forming a photocatalyst film of the present invention is a coating material used for forming a photocatalyst film as described above, which comprises titania fine particles and / or a titania precursor, silica fine particles and / or It is characterized by containing a silica precursor and a transition element compound.

In a preferred embodiment of the coating material of the present invention, the titania fine particles have an anatase structure, the titania precursor is a titania sol obtained by hydrolyzing a titanium alkoxide, and the silica precursor is A silica sol obtained by hydrolyzing a silicon alkoxide, wherein the transition element compound is tungsten (W), yttrium (Y), vanadium (V), cobalt (C
o), iron (Fe), molybdenum (Mo), chromium (C
r) at least one element selected from the group consisting of nickel (Ni) and lanthanum (La), selected from the group consisting of acetates, nitrates, hydrochlorides, ammonium salts, acetylacetonate salts and alkoxides At least one
It is a kind of compound.

Further, the method for producing a photocatalyst film according to the present invention is characterized in that, in producing the above-mentioned photocatalyst film, a desired film shape is imparted to the above-mentioned coating material, and then heating is performed.

[0015]

The ordinary titania catalyst does not exhibit catalytic activity unless irradiated with light having a wavelength of 380 nm or less, and cannot exhibit its performance under a condition of low ultraviolet rays, such as when used indoors. If the size of the titania particles is reduced in order to improve the activity itself, the absorption wavelength shifts to a shorter wavelength side, and is activated only by light having a shorter wavelength.

On the other hand, according to the present invention, by dispersing a transition element in a photocatalyst, the hydrophilicity can be recovered by light irradiation even under a condition of low ultraviolet rays, such as in a room or inside a window glass. It achieves long-term durability of stain resistance and anti-fog performance. The details of obtaining such excellent properties are not always clear, but at present, the added transition elements have caused high activation of the photocatalytic reaction and increase in the wavelength that causes this catalytic reaction. It is inferred.

In the photocatalyst film of the present invention, a predetermined layer using silica fine particles, silica sol, alumina fine particles, alumina sol, titania fine particles, titania sol or the like is overcoated on the photocatalyst layer in which such transition elements are dispersed. However, in this case, since the abundance ratio of the silica component and the alumina component on the outermost surface can be increased, the hydrophilicity can be further improved.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the photocatalyst film of the present invention will be described in detail. As described above, the photocatalyst film of the present invention has a photocatalyst layer, which contains titania and a transition element, preferably silica. The catalytic activity wavelength region of the photocatalyst film is 380 to 420 nm.

Here, the titania functions as a photocatalyst, and decomposes contaminants attached to the photocatalyst film to contribute to maintaining hydrophilicity for a long time. Titania may be amorphous or may have an anatase or rutile crystal structure, but most preferably has an anatase structure. As the transition elements, W, Y, V, Co, F
e, Mo, Cr, Ni or La and any mixture thereof can be suitably used, and it is considered that such a transition element brings about high activation of the photocatalytic reaction of titania, extension of the wavelength at which activity is exhibited, and the like. Further, silica is added as required and functions as a hydrophilic component imparting agent and a binder component. The details will be described later.

In the above photocatalyst layer, the content of such a component is
The amount is 45 to 95 parts by weight of titania and 5 to 55 parts by weight of silica.
Parts by weight, 10 g of the above transition element per 1 g of titania^-2~
10 ^-8It is preferably set to mol. Titania content
If less than 45 parts by weight, sufficient catalytic activity cannot be obtained, and
Exceeds 95 parts by weight, the film strength is extremely reduced and peels off.
May occur, which is not preferable. Furthermore, the transition source
If the elemental content deviates from the above range, the photocatalytic performance will increase.
It may be undesirably reduced.

The thickness of the photocatalyst film of the present invention is 50 to 50.
Preferably, it is 300 nm. Below 50 nm,
If the photocatalytic performance is not sufficient, and if it exceeds 300 nm, peeling of the film or the like is likely to occur.

In the photocatalyst film of the present invention, a hydrophilic maintenance layer containing silica, alumina, titania and a mixture thereof is laminated on the above-mentioned photocatalyst layer to improve the hydrophilicity of the entire photocatalyst film. However, in this case, the thickness of the hydrophilic maintenance layer is preferably set to 50 nm or less. If the thickness of the hydrophilicity-maintaining layer exceeds 50 nm, the photocatalytic performance is significantly reduced, which is not preferable.

Next, the stain-resistant anti-fog material of the present invention will be described. This antifouling antifogging material is obtained by coating the above-described photocatalyst film of the present invention on a substrate. In this case, examples of the substrate to be used include inorganic or organic materials such as metal, glass and resin. Can be Such a substrate may be transparent or opaque, and may be a mirror body having a mirror surface formed on one surface of the transparent substrate.

In this antifogging material, a silica layer, an alumina layer, a silica-alumina and a silica-titania composite are provided between the substrate and the photocatalyst film, more specifically, between the substrate surface and the above-mentioned photocatalyst layer. It is possible to insert a metal oxide layer such as an oxide layer, thereby avoiding oxidative decomposition of the substrate due to the reaction of titania as a photocatalyst component when the substrate to be used is made of an organic material. Can be.

The light source for exhibiting the functions of the photocatalyst film and the antifouling antifogging material of the present invention described above, specifically, the light source for decomposing the contaminants adhered by the catalytic properties of titania includes: For example, sunlight, mercury lamps, fluorescent lamps,
Examples include a halogen lamp, short arc xenon light, and laser light. In the present invention, a light source may be provided so that light is directly applied to a portion where the photocatalytic film (hydrophilic film) is formed. However, the photocatalytic film of the present invention has a catalytic active wavelength region of 380 as described above. Since the wavelength is about 420 nm, a special light source is not usually required, and the performance can be sufficiently obtained by natural light such as indoor fluorescent light or sunlight.

Next, the method for producing the photocatalyst film and the stain resistant antifogging material will be described in relation to the photocatalyst film forming coating material of the present invention. In the present invention, the photocatalyst film and the stain-resistant antifogging material impart a desired film shape to a coating material for forming a photocatalyst film described below. It is manufactured by applying the coating material to a substrate and then heating.

Here, the coating material is usually in a liquid state, and titania fine particles and / or a titania precursor,
It contains silica fine particles and / or a silica precursor and a compound of the above-mentioned transition element. The content of these components in such a coating solution is such that the resulting photocatalytic film has the above-mentioned component content, that is, 45 to 95 parts by weight of titania, 5 to 95 parts by weight.
55 parts by weight of silica, 10 ⁻² to 1 per 1 g of titania
It is preferable to control the ratio so as to satisfy 0 to ⁸ mol of the transition element.

As described above, anatase-type titania is most preferably used as the titania to be used. Such anatase-type crystal titania can be selected from commercially available ones, and one having a small particle diameter is preferable. And those having a particle size of 7 to 20 nm can be particularly preferably used. For example, Ishihara Sangyo serial number ST-01 has an average particle diameter of 7 nm, and ST-21 has an average particle diameter of 20 nm, and these may be appropriately selected and used.

The titania precursor may be any as long as it produces titania by firing. For example, a titania sol obtained by hydrolyzing a titanium alkoxide can be used. As described above, a commercially available titania sol can be used, but a titania sol having improved stability using a ligand can also be suitably used.
For example, as a ligand, the following general formula

[0030]

Embedded image

(Wherein R1, R2, R4 and R5 each represent an alkyl group having 1 to 5 carbon atoms, and R3 represents an alkyl group having 1 to 3 carbon atoms). And the like. Further, the above-mentioned diol type organic compound is added to a titanium alkoxide solution such as titanium tetraisopropoxide or tetraethoxytitanium in a molar ratio to titanium of 1: 1 to 1: 8, and then hydrolyzed. The titania sol or the like obtained can also be used.

The diol type organic compound is, specifically, 2-ethyl-1,3-hexanediol,
2,4-trimethyl-1,3-pentanediol, 1,
2-butanediol, 1,3-butanediol, 2,3
It is desirable to use selected from -butanediol or 2-methyl-2,4-pentanediol and any mixture thereof. Other commercially available titania sols include T
A-10, TA-15 (manufactured by Nissan Chemical Industries, Ltd.), Atron TiN-500 (manufactured by Nippon Soda Co., Ltd.) and the like can also be used.

When titania is produced using a titania precursor, if more anatase-type crystals are to be obtained in the photocatalytic film, anatase-type titania particles may be mixed and used. By dispersing anatase-type titania particles of fine particles (for example, a particle diameter of 7 to 20 nm) and titania sol in a coating solution, fine particles of anatase-type titania particles in which crystal growth of titania is added and dispersed in advance during firing after film formation. As a nucleus, the ratio of anatase titania in the film after firing can be stably increased. In this case, the ratio of titania sol to anatase titania particles is preferably 15:75 to 85: 1 in terms of titania equivalent weight ratio.

Next, the transition element compound is added to the coating solution such that the transition element is contained in a ratio of 10 ⁻² to 10 ⁻⁸ mol per 1 g of the generated titania in the obtained photocatalytic film. Is desirable. Such transition elements are as described above, and as the compounds of these transition elements, those which are soluble in the solvent of the titania precursor can be selected, for example, acetate, nitrate, hydrochloride of these transition elements, Examples include sulfates, ammonium salts, acetylacetonate salts or metal alkoxides and any mixtures thereof.

The silica fine particles to be used are preferably those having a particle diameter of 7 to 20 nm, and the silica precursor to be used is not particularly limited as long as it generates silica by firing. Specifically, silica sol or colloidal silica and a mixture thereof can be used. In addition, it is preferable that the compounding ratio of the silica precursor and the silica fine particles in this coating liquid is 5:95 to 99: 1 in terms of silica conversion weight ratio.

Such a silica sol can be prepared by hydrolyzing alkoxysilane, but a commercially available silica sol can also be used. For example, trade name Super Cera (manufactured by Daiichi Kagaku Kogyosho), trade name Cera Mica (manufactured by Nippon Institute), trade name HAS (manufactured by Colcoat)
Trade name: Atron SiN-500 (manufactured by Nippon Soda Co., Ltd.)
And trade name CGS-D1-0600 (manufactured by Chisso Corporation)
Etc. can be used. Further, such a silica sol forms an amorphous film after firing, and in the present invention, functions to greatly improve the abrasion resistance of the photocatalytic film. That is, since the titania after firing forms crystal grains, the obtained film itself may be brittle. Therefore, when stress is applied from the outside, brittle fracture may occur, and eventually, the material may be separated from the substrate. On the other hand, when an amorphous component such as silica is added to titania, the growth of crystal grains is appropriately controlled, so that it becomes possible to withstand external stress and the wear resistance is improved. On the other hand, as the colloidal silica, for example, Snowtex (trade name) (manufactured by Nissan Chemical Industries, Ltd.) can be used, but it is not limited thereto.

In the present invention, the addition of colloidal silica or the like provides the following advantages. That is, although the titania itself, which is a constituent component of the photocatalytic film, is hydrophilic, the surface activity is extremely high, so that when left in the air, contaminants such as hydrocarbons are adsorbed and lose hydrophilicity. . In an environment where the irradiation intensity of ultraviolet rays is large, organic contaminants adsorbed on the surface are decomposed, so that hydrophilicity can be maintained. However, it is difficult to maintain hydrophilicity for a long time at night or in rainy weather. . This problem can be solved by adding fine particles, such as colloidal silica, which contain a large amount of physically adsorbed water to the photocatalytic film.

Further, in addition to the above-mentioned essential components, a metal oxide capable of forming an amorphous metal oxide can be added to and mixed with the coating solution of the present invention.
Zirconia sols such as -30A, NZS-30B (manufactured by Nissan Chemical Industries, Ltd.) and AZS-A, AZS-NB, AZS-B (manufactured by Nippon Shokubai Chemical Co., Ltd.), and alumina sol-100, trade name alumina sol Alumina sol such as -200, alumina sol-520 (manufactured by Nissan Chemical Industry Co., Ltd.) and Cataloid AS-3 (trade name, manufactured by Catalyst Chemical Industry Co., Ltd.) can be used. Furthermore, a composite oxide sol such as silica-alumina and silica-zirconia can be used.

The amount of the amorphous metal oxide to be added is such that the total of titania and metal oxide
When it is 0% by weight, it is preferably in the range of 5 to 20% by weight. If the amount is less than 5% by weight, the effect of improving the wear resistance cannot be expected. If the amount exceeds 20% by weight, the crystal growth is inhibited and the photocatalytic effect may not be obtained.

Further, the coating liquid of the present invention can contain other metal oxides. Specifically, iron titanate, bismuth oxide, tin oxide, manganese oxide, zinc oxide, Copper, silver oxide or zirconium oxide and any mixtures thereof can be included. Further, as these metal oxides, particulate oxides already in the form of oxides may be used, but it is also possible to use salts that become these oxides by firing. Examples of such metal salts include acetates, nitrates, hydrochlorides, sulfates, ammonium salts, acetylacetonate salts or metal alkoxides of the metal and any mixtures thereof.

In the method for producing a photocatalyst film and a stain-resistant antifogging material of the present invention, typically, the above-mentioned coating solution is applied on a substrate so that the film thickness becomes 50 to 300 nm after heat treatment. . Next, the coating film is dried, and thereafter,
Baking is performed at 500 to 700 ° C. Such coating methods include a water immersion pulling method (dipping method), a spray method,
Known methods such as a flow coating method and a spin coating method can be appropriately employed. When the firing temperature is lower than 500 ° C., the film hardness is insufficient. When the firing temperature is higher than 700 ° C., the glass substrate frequently used as a base material is softened, and a transmission image may be distorted. Is not preferred.

As described above, in the photocatalyst film and the antifouling antifogging material of the present invention, silica, alumina or titania and any of them are provided on a layer (photocatalyst layer) containing titania, silica and a transition element. Can be employed in which a layer containing a mixture of the above (a hydrophilic maintenance layer) is laminated. In order to form such a layer structure, the coating liquid is applied to a substrate and dried at 100 to 300 ° C., and then the coating liquid for forming a hydrophilic maintenance layer has a thickness of 5 after firing.
The coating may be performed so as to have a thickness of 0 nm or less, dried, and then fired in the above temperature range. The application method is the same as described above.

As such a coating liquid for forming a hydrophilic maintenance layer, those containing the above-mentioned components for forming silica or the like upon firing can be used. Specifically, silica fine particles, silica sol, alumina fine particles, alumina sol,
It is preferable to use titania fine particles or those containing titania and any mixture thereof. In this case, the particle size of alumina is typically 10 to 50 nm. In order to further improve the hydrophilicity maintaining performance, it is desirable to use silica and alumina in combination.

Here, the same silica fine particles, silica sol, titania fine particles and titania sol as described above can be suitably used. On the other hand, as the alumina sol, one obtained by hydrolyzing an aluminum alkoxide or the like can be used, and further, a commercially available alumina sol can be used. Examples of the dispersion liquid of alumina fine particles that can be suitably used include alumina sol-100, alumina sol-200, and alumina sol-520 (manufactured by Nissan Chemical Industries, Ltd.) and Cataroid AS-3 (trade name, manufactured by Catalyst Chemical Industry Co., Ltd.). And the like.

The content of the silica and / or alumina fine particles in the hydrophilic maintenance layer is 0% with respect to the entire layer.
It is preferably from 100 to 100% by weight, preferably from 10 to 50% by weight. If the amount is less than 10% by weight, sufficient hydrophilicity maintaining performance cannot be obtained, and if it exceeds 50% by weight, the photocatalytic performance of the photocatalyst film or the stain resistant antifogging material may not be sufficiently obtained. On the other hand, if the content of titania in the hydrophilicity maintaining layer is too large, the hydrophilicity maintaining performance may be degraded. Therefore, the content is preferably 50% by weight or less.

The above sol solution can be used by diluting it with water or an organic solvent, if necessary. Any organic solvent may be used as long as it dissolves the metal oxide sol contained in the coating solution. Examples thereof include primary alcohols such as methanol, ethanol and propyl alcohol, and secondary alcohols such as isopropylene alcohol. , Tertiary alcohols such as tertal butanol,
Ketones such as acetone and methyl ethyl ketone, ethers, benzene, toluene, xylene, chloroform,
Aliphatics such as pentane, hexane and cyclohexane,
Common solvents such as aromatic and alicyclic hydrocarbons can be mentioned, and these can be used alone or in combination.

Further, in the stain-resistant antifogging material of the present invention, as described above, when an organic material or soda lime glass which is easily oxidized and decomposed by a photocatalyst is used as a base material,
Provide a predetermined metal oxide layer as an intermediate layer on this substrate,
Further, a photocatalyst film may be coated thereon. In this case, the coating liquid for forming the silica and / or alumina-based intermediate layer may be any coating liquid that can prevent the diffusion of Na from soda lime glass. Silica-alumina, silica-titania composite oxide and the like can be suitably added. Further, another metal oxide may be mixed in the intermediate layer. When sodium ions are present in the titania _film, to form a _{TiO 2 (2-x) Na} x,
This is because it becomes a recombination site of holes and electrons generated by ultraviolet rays, so that photolysis performance may be reduced.

In addition, as a method of controlling the weight ratio of silica and / or alumina components to titania on the surface of the photocatalytic film, the specific gravity of silica and / or alumina fine particles is determined by adjusting the specific gravity of titania to an amorphous metal oxide sol and a dilution solvent. There is a method in which a coating is formed so as to have a specific gravity lower than the specific gravity.
According to this method, silica and / or alumina fine particles can be used even when a coating liquid in which the silica and / or alumina components with respect to titania are mixed in a weight ratio of 1: 0.1 to 1: 1.3 is used. Is floated near the outermost surface, so that the desired configuration can be obtained.

[0049]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In addition, the performance of the photocatalyst film obtained in each example was evaluated by the following evaluation items, and the obtained results are shown in Tables 2 and 4.

(Water Drop Contact Angle) The water drop contact angle on the film surface was measured. To determine the presence or absence of hydrophilicity, a contact angle of 1
If it is 0 ° or less, it can be determined that the wetting effect and the anti-fog effect are excellent, and if it is 20 ° or less, it can be determined that there is a wetting effect.

(Photocatalytic performance) The surface of the film coated with oleic acid was evaluated by irradiating it through a laminated glass with xenon light having an irradiation intensity of ² mW / cm ² for 48 hours, and the catalytic property was judged by the contact angle of water droplets after photolysis. did.

(Hydrophilic maintenance ability) UV intensity is 0.01
It was left for 24 hours in an environment of mW / cm ² or less, and was judged by an increase in the contact angle of a water droplet.

(Abrasion resistance) Using a canvas cloth as a wear element, a sliding test was performed 3000 times under a load of 100 g / cm ² , and the appearance was visually evaluated.

(Durability) The film was immersed in 5% salt water at 70 ° C., and the presence or absence of film peeling or flaws was visually evaluated.

(Examples 1 to 4) Anatase type crystalline titania particles (Ishihara Sangyo: ST-01 / particle diameter 7 nm, ST-2)
1 / particle diameter 20 nm) and silica sol (Atron NSi-
500, trade name manufactured by Nippon Soda Co., Ltd.), colloidal silica as fine silica particles (ST-O, trade name manufactured by Nissan Chemical Industry Co., Ltd.), and a transition metal element were added, as shown in Table 1. Was blended in. A coating liquid was obtained by adjusting the total amount of all metal oxides to 2% by weight when the solid content concentration was used, and the coating liquid was applied on a quartz glass plate as a base material by a spin coating method. 80 rp
m, for 30 seconds. Since the solvent was not completely evaporated even after the spin, the sample was left to stand and air-dried until the surface became tack-free. 150 ° C after air drying
, And baked at 650 for 15 minutes to obtain a coating (photocatalytic film) of each example.

(Examples 5 to 31) A soda lime glass plate was used as a substrate, and a commercially available silica sol (Atron NSi
-500, trade name of Nippon Soda Co., Ltd.) with isopropyl alcohol so as to be 1.5% by weight in terms of silica, and spin coating at 200 rpm and 30 rpm.
After coating under the condition of seconds, it was dried at 200 ° C. for 10 minutes.

Titanium tetraisopropoxide as an alkoxide of titanium was dissolved in ethanol at a concentration of 0.5 mol / L, and ligands having the contents shown in Tables 1 and 3 were added thereto. The ligand was added in an amount of 1 to 8 mol per 1 mol of the alkoxide, and the mixture was refluxed for 1 hour. After cooling to room temperature, nitric acid was added to the mixture to make it acidic, water was added dropwise in an equimolar amount to the alkoxide, and the mixture was refluxed for 1 hour to obtain a titania sol.

The titania sol solution obtained as described above is mixed with anatase-type crystalline titania particles (Ishihara Sangyo: ST).
-01 / particle diameter 7 mm, ST-21 / particle diameter 20 mm),
Commercially available silica sol (Atron NSi-500, trade name of Nippon Soda Co., Ltd.) and colloidal silica as silica fine particles (ST-O, trade name of Nissan Chemical Industries, Ltd.)
And a transition metal element, and Examples 5 to 5 of Tables 1 and 3 were added.
The coating liquid shown in No. 31 was prepared. At this time, as a rule, the total amount of all metal oxides was adjusted to be 2% by weight when the solid content concentration was used. This coating solution was coated on the substrate by a spin coating method at 80 rpm for 30 seconds. Since the solvent was not completely evaporated even after the spin, the sample was left to stand and air-dried until the surface became tack-free. 150 after air drying
After drying at 10 ° C. for 10 minutes, it was baked at 650 ° C. for 15 minutes to obtain a coating (photocatalytic film) of each example. However, in Example 30, the total amount of all the metal oxides was set to 0.4% by weight, and in Example 31, the total amount of all the metal oxides was set to 2.2% by weight. %.

Examples 32 to 49 Titanium tetraisopropoxide as an alkoxide of titanium was dissolved in ethanol at a concentration of 0.5 mol / L, and a ligand having the contents shown in Table 3 was added thereto. The ligand is alkoxide 1
2 mol per mol was added, and the mixture was refluxed for 1 hour. After cooling to room temperature, nitric acid was added to the mixture to adjust it to be acidic, and water was added dropwise in an equimolar amount to the alkoxide, and the mixture was refluxed for 1 hour to obtain a titania sol.

A commercially available silica sol (Atron NSi-500, trade name of Nippon Soda Co., Ltd.) and a commercially available colloidal silica (ST-O, Nissan Chemical Industries, Ltd.) were added to the titania sol solution obtained as described above. ) And a transition metal element were mixed to prepare coating liquids shown in Examples 32 to 49 in Table 3. In addition, it adjusted so that it might become 2 weight% when the total amount of all the metal oxides was made into solid concentration.

A quartz glass plate was used as a base material, and the above coating solution was spin-coated at 80 rpm.
m, for 30 seconds. Since the solvent was not completely evaporated even after the spin, the sample was left to stand and air-dried until the surface became tack-free. 150 ° C after air drying
For 10 minutes to cover the first layer of the coating of each example.

Next, the coating liquid for the second layer was obtained according to the mixing ratio of the second layer shown in Examples 32 to 49 in Table 3, and this was coated on the first layer. Here, in the coating liquid of the second layer, the silica fine particles, silica sol, titania fine particles and titania sol used in the coating liquid of the first layer are used, and as the alumina sol, aluminum isopropoxide is 0.5 mol / L in ethanol. After dissolving in this manner, nitric acid was added thereto to adjust the solution to be acidic, then water was dropped in an equimolar amount to the alkoxide, and the mixture was refluxed for 1 hour. As the alumina fine particles, alumina sol-200 (particle diameter: 10 to 20 n)
m), alumina sol-520 (particle diameter 10-20 nm)
Using Nissan Chemical Industries, Ltd., coating liquids for the second layer having the contents shown in Examples 32 to 49 were prepared. In addition, it adjusted so that the total amount of all the metal oxides might be 1 weight% as a solid content concentration. The obtained coating solution for the second layer was coated at 400 rpm and 30 rpm by a spin coating method.
After coating on the first layer under the condition of seconds, air-dry,
After drying at a temperature of 10 ° C. for 10 minutes, it was baked at 650 for 15 minutes to obtain a laminated type coating (photocatalytic film) of each example. However, in Example 48, it was 100 rpm and 30 seconds, and in Example 50, it was 250 rpm.
Coating was performed at pm for 30 seconds.

(Comparative Examples 1 and 2) Titania in the obtained coating film (photocatalytic film) was blended so as to be 40% by weight, and a film to which a ligand was added and a film to which no ligand was added were produced. However, no transition element was added.

(Comparative Examples 3 and 4) Titania in the obtained coating film (photocatalytic film) was blended so as to be 40% by weight, and a film to which a ligand was added and a film to which no ligand was added were produced. However, no transition element was added.

(Comparative Examples 5 and 6) As an alkoxide of titanium, titanium tetraisopropoxide was dissolved in ethanol at a concentration of 0.5 mol / L, and a ligand having the content shown in Comparative Example 7 was added. The ligand is alkoxide 1mo
As shown in Table 3, 0.5 and 9 moles were added to 1
Refluxed for hours. After cooling to room temperature, nitric acid was added thereto to adjust the solution to be acidic, and water was added dropwise in an equimolar amount to the alkoxide, and the mixture was refluxed for 1 hour to prepare a coating liquid. However, no transition element was added. Comparative Example 7
For, gelation occurred and no coating liquid was obtained. In Comparative Example 8, the coating liquid shown in Table 3 was obtained, and a photocatalyst film was prepared using the coating liquid.

(Comparative Examples 7 and 8) On the basis of the coating solution of Example 30, the photocatalyst film in which the transition element was added in an amount of 10 ^-1 mol with respect to the titania in the photocatalyst film, and
^A photocatalyst film of ^-9 mol was produced.

Comparative Example 9 Using the coating solution of Example 49, coating was performed at 230 rpm for 30 seconds to produce a photocatalytic film.

[0068]

[Table 1]

[0069]

[Table 2]

[0070]

[Table 3]

[0071]

[Table 4]

[0072]

As described above, according to the present invention, a transition element is mixed in a photocatalyst film in which titania or silica is dispersed, or a transition element compound is added to a solution containing titania fine particles or a titania precursor. Is added and dispersed, coated on a substrate and heat-treated. Therefore, even in an environment with little UV light, it exhibits excellent antifogging properties and durability, and has excellent productivity as well. And its production method,
It is possible to provide a stain-resistant antifogging material, and a coating material for forming the same.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 23/28 B01J 23/30 M23 / 30 C03C 17/23 23/745 C09D 5/00 L 23/75 C09K 3/18 23/755 B01D 53/36 J C03C 17/23 B01J 23/74 301M C09D 5/00 311M C09K 3/18 321M (72) Inventor Yasuo Kai 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Automotive Stock In-house F-term (reference) 4D048 AA17 AA24 AB01 AB03 BA03X BA03Y BA06X BA06Y BA07X BA07Y BA23X BA23Y BA25X BA25Y BA26X BA26Y BA27X BA27Y BA28X BA28Y BA36X BA36Y BA37X BA37Y BA38X BA38Y BB03 A01A01 A01 A03 A01 A01 A01 A01 A01 A01 A01 A01 BA04A BA04B BA14A BA14B BA48A BB04A BB04B BC29A BC40A BC40B BC42A BC42B BC54A BC54B BC58A BC58B BC59A BC5 9B BC60A BC60B BC66A BC66B BC67A BC67B BC68A BC68B CA10 CA11 DA06 EA08 FB23 FC08 4H020 AA01 AB02 4J038 AA011 HA016 HA216 HA446 KA12 KA20 NA05 NA06 NA11 NA18 PB02 PB05 PC03

Claims (19)

[Claims] 1. A photocatalytic film having a photocatalytic layer containing titania and a transition element, and having a catalytic active wavelength range of 380 to 420 nm. 2. 45 to 95 parts by weight of titania, 5 to 55 parts by weight.
10 ^-2 to 1 per part by weight of silica and titania
The photocatalyst film according to claim 1, comprising 0 to ⁸ mol of a transition element. 3. The method according to claim 2, wherein the transition element is tungsten (W),
Yttrium (Y), vanadium (V), cobalt (C
o), iron (Fe), molybdenum (Mo), chromium (C
3. The photocatalyst film according to claim 1, wherein the photocatalyst film is at least one element selected from the group consisting of r), nickel (Ni), and lanthanum (La). 4. A photo-catalytic layer comprising a hydrophilic maintenance layer having a thickness of 50 nm or less containing at least one selected from the group consisting of silica, alumina and titania. The photocatalyst film according to claim 1. 5. The method according to claim 1, wherein at least a part of the titania has an anatase type structure.
The photocatalyst film according to any one of the above items. 6. A stain-resistant anti-fog material comprising a photocatalyst film according to claim 1 coated on a substrate. 7. The antifouling material according to claim 6, wherein a silica and / or alumina metal oxide layer is inserted between the substrate and the photocatalytic film. 8. The stain-resistant anti-fog material according to claim 6, wherein the base material is vitreous. 9. A coating material used for forming the photocatalyst film according to any one of claims 1 to 5, comprising titania fine particles and / or titania precursor, silica fine particles and / or silica. A coating material for forming a photocatalyst film, comprising a precursor and a transition element compound. 10. The coating material according to claim 9, wherein said titania fine particles have an anatase structure. 11. The titania fine particles having a particle size of 7 to 2
The coating material according to claim 9 or 10, wherein the thickness is 0 nm. 12. The method according to claim 9, wherein the titania precursor is at least one selected from the group consisting of titanium alkoxides, chlorides, complex compounds, nitrates and acetylacetonate salts. Item 12. The coating material according to any one of items 11. 13. The coating material according to claim 9, wherein the titania precursor is a titania sol obtained by hydrolyzing a titanium alkoxide. 14. The compounding ratio of the titania precursor and the titania fine particles is 15:75 to 8 by weight in terms of titania.
The coating material according to any one of claims 9 to 13, wherein the ratio is 5: 1. 15. The silica fine particles having a particle diameter of 7 to 20.
The coating material according to any one of claims 9 to 14, wherein the thickness of the coating material is nm. 16. The coating material according to claim 9, wherein the silica precursor is a silica sol obtained by hydrolyzing a silicon alkoxide. 17. The method according to claim 9, wherein a mixing ratio of the silica precursor and the silica fine particles is 5:95 to 99: 1 in terms of silica. The coating material as described. 18. The transition element compound may be selected from the group consisting of tungsten (W), yttrium (Y), vanadium (V), cobalt (Co), iron (Fe), molybdenum (Mo), chromium (Cr), and nickel (Ni). And at least one compound selected from the group consisting of acetate, nitrate, hydrochloride, ammonium salt, acetylacetonate and alkoxide of at least one element selected from the group consisting of lanthanum (La). Claim 9-
Item 18. The coating material according to any one of items 17. 19. In producing the photocatalyst film according to any one of claims 1 to 5, a desired film shape is imparted to the coating material according to any one of claims 9 to 18. And then heating the photocatalyst film.