Article with silica film containing powder of functional substance

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to articles useful for decomposition, removal, sterilization, etc. of various malodorous gases, harmful gases, harmful compounds in water, etc. generated in daily life, and specifically, exhibits decomposition effects of various organic substances and inorganic substances by irradiation with ultraviolet rays. A silica film containing a photocatalytic active substance such as titanium dioxide and zinc oxide and a deodorant containing titanium dioxide, iron oxide, zinc oxide and the like is placed on the substrate via a resin layer and a silica film fixed on the resin layer. Regarding the articles formed in. The obtained silica film on the surface of the article is characterized by being excellent in processability and weather resistance.

【0002】

[Conventional technology]

It is widely known that when a photocatalyst such as titanium dioxide is irradiated with ultraviolet rays, electrons are transferred from the valence band to the conduction band by photoexcitation to become an n-type semiconductor, which exhibits decomposition and bactericidal effects of various compounds, and is an organic substance in water. ("Water and waste water", vol.30 No.10 (1988) p943-948), decomposition and deodorization of organic matter, sterilization ("Surface" vol.25 No.8 (1987) p477-495, "Ceramics" 21 It has been reported that it can be used in (1986) No. 4, p326-333). However, when the photocatalytic activity is actually used for the purpose of decomposing and removing harmful gases in exhaust gas, malodorous gases such as cigarettes and toilets, harmful substances such as pesticides, and environmental pollutants, and sterilization, it is easy to use. , It is necessary to support and fix it on some substrate. In addition, few functional substance powders such as deodorants that have been developed in recent years are used in the form of powder.

【0003】

As an example of the functional substance powder, a method of supporting titanium dioxide for a photocatalyst on a substrate has been proposed below, for example. (1) Fine titanium oxide powder adheres to a film-shaped, bead-shaped, board-shaped, fibrous-shaped substrate made of a light-transmitting material such as nitrocellulose, glass, polyvinyl chloride, nylon, methacrylic resin, and polypropylene. Method to make (Japanese Patent Laid-Open No. 62-66861) (2) A method of impregnating a porous glass support with an alcohol solution of titanium (IV) tetrabutoxyoxide and heating it to form anatase-type titanium oxide to hold and fix it to the porous glass support (Japanese Patent Laid-Open No. 2-50154) (3) The semiconductor catalyst powder is held and fixed in a porous polymer membrane (for example, polyfluoroethylene resin) having a photosensitizer such as a dye or a metal complex as a side chain by press-fitting, impregnating, adhering, or the like. Method (Japanese Patent Laid-Open No. 58-125602) (4) Method of supporting titanium oxide on a filtration filter made of polypropylene fiber or ceramics (Japanese Patent Laid-Open No. 2-68190) (5) A method of holding and fixing titanium oxide powder in the entanglement of quartz, glass, and plastic fibers and holding both sides with light-transmitting glass (US Patent 4888101). (6) Platinum is fixed to an alumina substrate by a sputtering method, and a mixed dispersion of anatase-type titanium oxide powder and an organic solvent solution of methyl methacrylate is applied thereto by a spin coating method, and then a binder is applied. (Robert E. Hetric, Applied Physics Communications, 5, (3), 177-187 (1985)) (7) Method of spraying and supporting titanium oxide on the surface of polyester cloth by low temperature spraying method (Tsukasa Sakurada, Surface Technology Vol. 41, No. 10, P60 (1990)) [0004]

The above-mentioned methods for supporting the known photocatalytic titanium dioxide on a substrate have the following drawbacks. In fixing using organic substances such as (1), (3), (4), and (5) as binders, most of the organic substances are decomposed by the photocatalytic action of titanium dioxide, so fixing during long-term use is reliable. There is no. The method (2) uses an expensive organic titanium compound as a raw material and is directly supported on fragile glass, so that the strength is not reliable. Further, the methods (6) and (7) are not preferable because the temperature becomes very high during fixing and the high photocatalytic activity of titanium dioxide is lost. Other commonly used methods include simply an inorganic porous body, a method of impregnating and supporting slurry-like titanium dioxide in fibers, and a binder obtained by hydrolyzing or heating and melting an alkali salt such as silica or alumina. There are methods to use, but in the former, titanium dioxide particles are not fixed, so they easily fall off due to vibration or impact, and in the latter, the catalyst surface is covered with a binder for fixing the catalyst and is active. There was a problem that most of them were lost. Furthermore, since these methods require heat resistance and the like, the types of substrates that can be used are also limited, and since it is difficult to fix or process them on a wide surface, the cost is high, but the light energy cannot be fully utilized. There was a problem. This problem is common to all photocatalysts other than titanium dioxide and highly active substances such as adsorbents and bactericides. When these highly active substances are put into practical use, a fixing method that does not reduce the activity, has excellent strength, is inexpensive, and is easy to handle has been desired.

【0005】

PROBLEM TO BE SOLVED: To solve a problem

An object of the present invention is to solve the above problems, and the deodorizing effect of a deodorant, the bactericidal effect of an antibacterial agent, and the photocatalytic activity of titanium dioxide, etc._X It is an object of the present invention to provide an article having excellent processability and weather resistance, which is excellent in decomposing and removing harmful gases such as pesticides and environmental pollutants and bactericidal effect.

【0006】

[Means to solve the problem]

As a result of diligent research to achieve the above object, the present inventors applied a mixed solution of silicate ester, water and an arbitrary organic solvent on a resin layer prepared on the surface of a substrate to form a silica film. A resin prepared on a substrate and a surface of a substrate formed by applying a paint in which a functional substance powder is dispersed in a mixture of a siliceous ester, water and an arbitrary organic solvent on the silica film. An article composed of a layer, a silica film fixed on a resin layer, and a silica film containing a functional substance powder does not lose the characteristics of the functional substance, and has a deodorizing effect of a deodorant, a bactericidal effect of an antibacterial agent, and irradiation with ultraviolet rays. Odorous gas such as aldehyde and silica, NO_X Harmful gases such as pesticides, harmful substances such as pesticides, and photocatalytic effects such as decomposition and removal of environmental pollutants and sterilization, and adhesion and processing even when applied to non-heat resistant substrates such as aluminum plates and resins The present invention has been completed by finding that it has excellent properties and weather resistance.

【0007】

That is, the present invention relates to an article having a substrate, a resin layer formed on the surface of the substrate, a silica film fixed to the resin layer, and a silica film containing a functional substance powder fixed on the silica film. The substrate may be any as long as it can form a resin layer on its surface, but preferably contains at least one selected from the group consisting of aluminum, iron, nickel and copper as a main component. It is selected from metallic materials, glass, ceramics, resins, cloths, fibers, or combinations thereof. The type of resin layer formed on the surface of the substrate is epoxy, if there is adhesion to the substrate and solubility in silicate, a mixture of water and any organic solvent or alcohol produced by hydrolysis of the silicate. Anything can be used, such as acrylic, urethane, silicone resin, ordinary paint resin, etc. Of these, acrylic and epoxy resins are preferable, and epoxy resins are particularly preferable because they have strong adhesiveness to various substrates. As the epoxy resin, any of bisphenol A type, novolak type, and aliphatic type resins can be used. The type of epoxy resin and the type of curing agent can be appropriately selected according to the type of the substrate to be used and the required performance. It is also possible to add a pigment to the resin to color it, or to add an ultraviolet absorber to improve the light resistance. It is sufficient that the thickness of the resin layer is 1 μm or more.

【0008】

The functional substance powder used in the production of the silica film of the present invention refers to a powder having functions such as photocatalyst, deodorization and antibacterial, and those having photocatalytic function include titanium dioxide, iron oxide and deodorizing function. Examples thereof include titanium dioxide, iron oxide and zinc oxide, and those having an antibacterial function include compounds such as silver, copper and zinc. In addition, a porous body carrying these, a microcapsule containing a drug, and the like are also included. Although these have high activity, they tend to lose their activity due to surface coating or heating during immobilization, and when they are fixed by painting with a resin or the like, the resin is deteriorated due to the activity. There are many problems such as. In the fixing with the silica film of the present invention, these highly active substances are uniformly fixed in the silica film at a relatively low temperature, and further fixed on the resin layer formed on the surface of the substrate via the silica film to form a resin. The resin layer can be fixed to the substrate as a strong binder without fear of deteriorating the layer. The particle size of the functional substance powder is preferably 5 μm or less, more preferably 0.5 μm or less, and most preferably 0.1 μm or less in terms of coating film strength. As an example of the functional substance powder, titanium dioxide for photocatalyst is preferably anatase type and has a specific surface area of 20 m.² / g or more is preferable, 50m² / g or more is more preferable. It is also preferable that titanium dioxide contains metal oxides such as W, Sn, Mo, V, Mn, Pt, Ni, Ag, Cu and Zn that improve the catalytic activity. In addition to these functional substance powders, pigments and the like can be added to the silica film.

【0009】

In the article of the present invention, since the silica film containing the functional substance powder is fixed to the substrate via the silica film fixed on the resin layer, the resin is not deteriorated by the functional substance powder. In particular, a deodorant containing titanium dioxide for a photocatalyst and titanium dioxide has a strong tendency to decompose the resin by irradiation with ultraviolet rays, but the silica film of the present invention is characterized in that the resin layer is not easily deteriorated by ultraviolet rays for a long time. There is. In addition, both silica films fixed on the resin layer are integrated on the adhesive surface with each other, and due to the dehydration of the silica sol caused by the hydrolysis of the silicic acid ester and the shrinkage of the volume due to the evaporation of the solvent, it is several μm to several tens of μm or more. Because it is divided into blocks, for example, even if the metal plate with both silica films fixed is bent and processed, or the cloth with both silica films fixed is folded, the deformation can be absorbed, so peeling is unlikely to occur. It also has the advantage of. Since the strength tends to decrease as the thickness of both silica films increases, the film thickness is preferably 100 μm or less. The ratio of the functional substance powder in the silica film containing the functional substance powder fixed on the silica film fixed on the resin layer is preferably 10 to 90% by weight, more preferably 20 to 85% by weight. , Most preferably 40-80% by weight. As a method of providing a resin layer on the surface of the substrate, a method of providing a silica film on the resin layer, and a method of providing a silica film containing a functional substance powder on the silica film, known methods can be used. An appropriate coating method such as coating, spraying, or dipping can be selected according to the shape.

【0010】

The present invention is further a method for producing the above-mentioned article, in which a mixed solution of a silicate ester, water and an arbitrary organic solvent is formed on a resin layer prepared on the surface of a substrate, and the silicate ester is further formed on the resin layer. Provided is a production method in which a coating film in which a functional substance powder is dispersed in water or an arbitrary organic solvent is formed and then heat-treated at 400 ° C. or lower. Any known silicate ester can be used, but methyl silicate, ethyl silicate, and butyl silicate are preferable, and ethyl silicate is most preferable. In the mixed liquid which is the raw material of the silica film to be formed on the resin layer, the organic solvent is mixed with the silicic acid ester and alcohol which is a decomposition product thereof, in order to adhere the silica film to the substrate well. It is necessary to be able to dissolve the resin layer. Further, in the paint in which the functional substance powder is dispersed, the organic solvent is compatible with the silica sol produced by the hydrolysis of the silicic acid ester to enhance the dispersibility of the functional substance powder particles and facilitate the application. is required. If the alcohol produced by the hydrolysis of the silicic acid ester has the property of dissolving the resin layer and the amount thereof is sufficient, it is not necessary to add a solvent.

【0011】

The type of solvent can be appropriately selected depending on the type of resin layer to be used, and typical examples thereof include cellosolves, carbitoles and alcohols. Among the cellosolves, those having an alkyl group are preferable, and butyl cellosolve having a butyl group is particularly preferable. Among the carbitols, carbitol and carbitol acetate are preferable. As alcohols, ethanol and butanol are preferable.

【0012】

The water added to the paint is used for hydrolysis of silicic acid ester, but the paint pH is preferably acidic and pH 4 or less in order to increase the dispersibility of the functional substance powder in the paint and the strength of the paint film. Is more preferable, and pH 2 or less is particularly preferable. As a method for lowering the paint pH, it is preferable to add a small amount of acid to water to adjust the paint pH. Further, the pH of the mixed solution as a raw material for the silica film containing no functional substance powder is preferably acidic. As the acid added to water, hydrochloric acid, sulfuric acid, nitric acid and the like can be used.

【0013】

First, the mixing ratio of the mixed solution as the raw material of the silica film to be fixed on the resin layer is 25 to 100 parts by weight, preferably 50 to 100 parts by weight, with respect to 100 parts by weight of the silicic acid ester, and 0 for the organic solvent. It is ~ 2000 parts by weight, preferably 0 ~ 500 parts by weight. Next, the blending ratio of the coating material for producing the silica film containing the functional substance powder to be fixed on the silica film is the case where ethyl silicate is used as the silicic acid ester with respect to 100 parts by weight of the functional substance powder. , Ethyl silicate is 30 to 3200 parts by weight, preferably 60 to 1400 parts by weight, more preferably 80 to 520 parts by weight, and when methyl silicate and butyl silicate are used as silicate esters, the preferable amounts are respectively. The coefficient corresponding to the ratio of molecular weights of 0.73 and 1.54 is multiplied by the value of ethyl silicate. The solvent is 0 to 1000 parts by weight, preferably 0 to 500 parts by weight, and the water is 10 to 1100 parts by weight, preferably 20 to 500 parts by weight, and more preferably 30 to 200 parts by weight. In the above blending ratio, if the amount of the functional substance powder is less than the blending ratio, the photocatalytic activity as a film is lowered, and if it is more than the blending ratio, the adhesion and strength of the silica film are deteriorated, which is not preferable.

【0014】

The silica film obtained by applying it on the resin layer after a long time has passed after preparing a mixed solution of silicic acid ester, water and an arbitrary organic solvent is easy to peel off, especially when the acid concentration and liquid temperature of the mixed solution are high. Since the tendency is strong, the mixed solution should be applied at 90 ° C. or lower, preferably within 1 week. If a paint for creating a silica film containing a functional substance powder is applied immediately after applying a mixed solution of silicate ester, water and any organic solvent, the two are completely mixed and the functional substance is mixed. This is the same as applying a silica film with a small proportion of powder, which is not preferable because contact between the functional substance powder and the resin occurs. In order to integrate the silica film fixed on the resin layer and the silica film containing the functional substance powder fixed on the silica film on the adhesive surface, a mixture of silicic acid ester, water and an arbitrary organic solvent is required. After applying the liquid on the resin layer prepared on the substrate, the functional substance powder is contained within 1 week, preferably within 3 days, particularly preferably within 1 day at 90 ° C or lower, preferably 60 ° C or lower. It is better to apply the applied paint. The heat treatment after applying the latter is preferably performed in a temperature range in which oxidation, alteration and deformation of the resin layer and the substrate do not occur. Generally, 400 ° C or lower is preferable, but 100 to 400 ° C is more preferable because gelation of the silica sol takes a long time and it is difficult to obtain film strength at 100 ° C or lower. The silica film containing the functional substance powder of the present invention becomes porous by evaporation of alcohol generated by hydrolysis of silicic acid ester, dehydration of silica sol, and evaporation of solvent, and contact between the functional substance powder and atmosphere. However, in order to make the silica film more porous, a soluble substance such as boric acid is added to the paint in which the functional substance powder is dispersed, the silica film is solidified, and then the coating film is heated with warm water. It is also possible to remove soluble substances by washing with. Further, even when no soluble substance is added to the paint, free silica, deposits and the like are removed by cleaning the coating film, so that the activity of the functional substance powder in the film is improved. Furthermore, when the functional substance powder has photocatalytic activity, it is irradiated with ultraviolet rays on the surface of the functional substance powder particles.

【0015】

Since it is preferable to spread fine particles thinly and fix the functional substance powder in order to improve efficiency, it is preferable to apply it as a paint on a substrate and fix it as a coating film. In the production method according to the present invention, by adding an organic solvent to a mixed solution of silica ester and water, not only the stability, viscosity, dispersibility and drying rate of the mixed solution are improved, but also the surface of the substrate is coated. The resin is dissolved by applying it to the surface of the produced resin layer to form a layer in which silica and resin are mixed, and then a paint containing a functional substance powder is applied onto the layer, and both silica layers are bonded to each other. At the same time, we succeeded in firmly fixing it on the resin layer. Moreover, since the functional substance powder itself is fixed in the silica film and is interposed through the silica film fixed on the resin layer, the effect of not directly contacting the resin and not deteriorating the resin can be obtained. Further, even if the resin is sensitive to ultraviolet rays, the silica film fixed on the resin layer and the functional substance shield the ultraviolet rays, so that the resin also has an advantage of preventing deterioration. When forming the first silica film, it is conceivable to apply a resin in which the resin is dissolved in the mixed solution in advance on a substrate on which a resin layer has not been formed and fix the resin film. According to this method, the functional substance and the resin come into contact with each other, causing deterioration of the resin, which is not preferable.

【0016】

The silica film in the article of the present invention becomes porous due to dehydration from the silica sol produced by hydrolysis of the siliceous ester, evaporation of alcohol, and evaporation of an organic solvent, and the contained functional substance powder particles become an atmospheric gas or gas. Since it easily comes into contact with surface-adsorbed substances such as water and bacteria, it can react efficiently with these substances. The article according to the present invention is preferably used as a deodorant. That is, as one aspect of the present invention, a substrate, a resin layer formed on the surface of the substrate, a silica film fixed on the resin layer, and a deodorant or photocatalytic titanium dioxide fixed on the silica film. Provided is a deodorant having a silica film containing a functional substance powder such as. Of the functional substances, titanium dioxide, which has photocatalytic activity, has NO in addition to the deodorizing effect of aldehydes and mercaptans._X , Inorganic gases such as ammonia and hydrogen sulfide, harmful substances such as pesticides, decomposition and removal of environmental pollutants, and sterilization and removal of fungi and algae are known as photocatalytic effects. It is clear that other effects known as effects can be obtained at the same time. The contents of the present invention will be described in more detail with reference to Examples below, but these Examples are merely examples, and the scope of the present invention is not limited thereto.

【0017】

Example 1 A deodorant composed of a tightly bonded product of titanium dioxide and zinc oxide was produced by the method described in Japanese Patent Publication No. 3-33022 by the following procedure. 1 liter of pure water was separated into a 5 liter beaker, and the mixture was heated and held at a temperature of 60 ° C with stirring. Next, TiO prepared separately₂ 2 liters of a titanium sulfate-zinc sulfate mixed aqueous solution containing 144 g as and 16 g as ZnO and an aqueous ammonia solution were simultaneously added dropwise to the pure water over 30 minutes, taking care to maintain the pH of these combined solutions at 7.5. did. After filtering and washing the product, it is dried at 200 ° C for 3 hours, and a deodorant consisting of tightly bonded particles of titanium dioxide and zinc oxide (specific surface area 410 m).² / G, average particle size 0.4 μm) was manufactured. Put 6 g of the above deodorant, 9 g of ethyl silicate, 3 g of water with 0.5 mol of hydrochloric acid, 0.12 g of boric acid and 6 g of butyl cellosolve in a 120 ml mayonnaise bottle together with 90 g of 3 mm glass beads, and 10 with a paint conditioner manufactured by Red Devil. It was dispersed and mixed for a minute to obtain a paint containing a deodorant. Further, 6 g of ethyl silicate and 2 g of water to which 0.05 mol of hydrochloric acid was added were placed in a 120 ml mayonnaise bottle and dispersed for 1 minute with a paint conditioner manufactured by Red Devil Co., Ltd. to prepare a mixed solution. Apply the above silica sol to the epoxy resin coated surface (60 mm x 150 mm x 0.5 mm) of Sky Coat manufactured by Sky Aluminum Co., Ltd. with a 2 mil doctor blade, and after 30 minutes, apply the above paint to the 2 mil doctor blade. Was applied with. After air-drying for a whole day and night, it is baked at 150 ° C for 1 hour to form a silica film, then washed with warm water at 60 ° C to remove boric acid, and then irradiated with ultraviolet rays to irradiate the deodorant particles with organic matter adhering to the surface. Was disassembled and removed. From the scanning electron microscope observation, it was confirmed that a silica film containing the deodorant particles was formed on the surface of the substrate on the silica film not containing the deodorant, and these films were fixed on the substrate by the resin. It was. The thickness of the silica film is about 20 μm, and the weight of the silica film is about 1.5 mg / cm.² Met. This film is When the adhesiveness and hardness of the coating film were examined by the method of JIS-K5400, the adhesiveness was an evaluation point of 10 and the pencil hardness was 3H or more. Cut out the coated surface by 5 cm x 1 cm, put it in a 120 ml glass bottle, inject acetaldehyde to an amount that makes the gas concentration in the bottle 1000 ppm, leave it at room temperature for 1 hour, and then let the air in the bottle be made by Yanagimoto Seisakusho. The acetaldehyde concentration was 0 ppm as measured by gas chromatograph G3800 (detector FID). By the same test, in any case of 100 ppm of acetic acid, 1000 ppm of trimethylamine, 1000 ppm of ethyl mercaptan, and 50 ppm of dimethyl sulfide, it became 0 ppm after 1 hour. In addition, when the deodorant powder used 10 mg (almost the same amount as that contained in the coating film surface of 5 cm x 1 cm) was subjected to the same deodorization test of acetaldehyde, the rate of decrease in concentration was almost the same. It is considered that there is not much decrease in activity due to coating film formation. Table 6 shows the current deodorizing data for acetaldehyde and ethyl mercaptan. Furthermore, this coating film was applied to 3.0 mW / cm using a Dew panel optical control weather meter manufactured by Suga Test Instruments Co., Ltd.² No discoloration or strength deterioration of the coating film occurred after irradiation with ultraviolet rays for 500 hours.

【0018】

Example 2 Titanium dioxide (antase type, specific surface area 60 m)² / g, average particle size 0.1 μm) 6 g, ethyl silicate 9 g, water 3 g with 0.5 mol hydrochloric acid, boric acid 0.12 g and butyl cellosolve 6 g were placed in a 120 ml mayonnaise bottle together with 90 g of 3 mm glass beads. Dispersed and mixed for 10 minutes with a paint conditioner made of Titanium Dioxide to obtain a paint containing titanium dioxide. Further, 6 g of ethyl silicate, 2 g of water to which 0.05 mol of hydrochloric acid was added, and 4 g of butyl cellosolve were placed in a 120 ml mayonnaise bottle and dispersed for 1 minute with a paint conditioner manufactured by Red Devil to prepare a mixed solution. Apply the above mixture to the epoxy resin coated surface (60 mm x 150 mm x 0.5 mm) of Sky Coat manufactured by Sky Aluminum Co., Ltd. with a 2 mil doctor blade, and after 30 minutes, apply the above paint to a 2 mil doctor. It was applied with a blade. After air-drying for a whole day and night, it is baked at 150 ° C for 1 hour to form a silica film, then washed with warm water at 90 ° C to remove boric acid, and then irradiated with ultraviolet rays to decompose organic substances adhering to the catalyst. Removed. From the scanning electron microscope observation, it was confirmed that a silica film containing titanium dioxide was formed on the silica film not containing titanium dioxide on the surface of the substrate, and these films were fixed on the substrate by the resin. The thickness of the silica film is about 20 μm, and the weight of the silica film is about 1.5 mg / cm.² Met. When the adhesiveness and hardness of the coating film of this film were examined by the method of JIS-K5400, the adhesiveness was an evaluation point of 10 and the pencil hardness was 3H or more. Put the coating film cut out to 5 cm x 1 cm in a 120 ml glass bottle, inject acetaldehyde in an amount that makes the gas concentration in the bottle 1000 ppm, and inject ultraviolet rays with a wavelength of 350 nm from the outside of the bottle 4.0-4.4 mW / cm.² After irradiating with the above for 1 hour, the air in the bottle was measured with a gas chromatograph G3800 (detector FID) manufactured by Yanagimoto Seisakusho, and the acetaldehyde concentration was 0 ppm. Similarly, acetic acid 50 ppm, trimethylamine 1000 ppm, and dimethyl sulfide 50 ppm became 0 ppm after 1 hour of ultraviolet irradiation. In addition, with 1000 ppm of ethyl mercaptan, it became 60 ppm after 1 hour of ultraviolet irradiation. Further, when the decomposition test of acetaldehyde was carried out in the same manner with 10 mg of the titanium dioxide powder for catalyst used above (almost the same amount contained in the coating film surface of 5 cm × 1 cm), the rate of decrease in concentration was almost the same. It is considered that there is not much decrease in catalytic activity due to the coating film formation this time. Table 7 shows the removal data of acetaldehyde and ethyl mercaptan by this ultraviolet irradiation. When a coating film cut into 5 cm x 1 cm and 20 ml of water were placed in a glass test tube and left outdoors for a week, algae grew in those without the coating film, but the coating film was added. There was no change in what was. Furthermore, this coating film was applied to 300 mW / cm using a Dew panel optical control weather meter manufactured by Suga Test Instruments Co., Ltd.² No discoloration or strength deterioration of the coating film occurred after irradiation with ultraviolet rays for 500 hours.

【0019】

Example 3 In Example 1, the paint was iron oxide (plate-like hematite, specific surface area 40 m).² / g, major axis / minor axis ratio 5) 6 g, ethyl silicate 9 g, water 3 g with 0.5 mol nitric acid added, boric acid 0.12 g and butyl cellosolve 6 g are charged in a 120 ml mayonnaise bottle together with 90 g of 3 mm glass beads, and red. A silica film containing iron oxide and a silica film not containing iron oxide were prepared on the substrate in the same manner except that the mixture was dispersed and mixed with a paint conditioner manufactured by Devil Co., Ltd. for 10 minutes.

【0020】

Example 4 In Example 1, the paint was zinc oxide (specific surface area 10 m).² / g) 6 g, 9 g of ethyl silicate, 3 g of water with 0.5 mol of nitric acid, and 6 g of butyl cellosolve were placed in a 120 ml mayonnaise bottle together with 90 g of 3 mm glass beads, and dispersed and mixed with a paint conditioner manufactured by Red Devil for 10 minutes. A silica film containing zinc oxide and a silica film not containing zinc oxide were produced on the substrate in the same manner except that the silica film was produced in the same manner.

【0021】

Example 5-7 In Example 2, the silica film containing titanium dioxide was formed in the same manner except that the substrate was a polyester, acrylic and fluororesin coated surface (60 mm × 150 mm × 0.5 mm) of Skycoat manufactured by Sky Aluminum Co., Ltd. A silica film containing no titanium dioxide was prepared on the substrate. These are shown in Tables 1 and 2.

【0022】

Example 8-21 In Example 2, a film was prepared in which a silica sol containing no titanium dioxide particles and a coating material in which titanium dioxide particles were dispersed were blended, and the type of resin to be applied to the substrate, the application method, and the like were changed. These are shown in Tables 1 and 2. Table 7 shows the data for removing acetaldehyde and ethyl mercaptan by ultraviolet irradiation in Examples 8-21 in the same manner as in Example 2.

【0023】

Examples 22,23 A film was prepared in the same manner as in Example 21 except that the substrate was polypropylene cloth and fibers. Even after bending 100 times or more and washing in a washing machine, no weight loss due to peeling of the silica film was observed.

【0024】

Comparative example 1 In Example 1, the paint film containing titanium dioxide was directly applied to the aluminum plate and baked at 150 ° C. for 1 hour, and the powder was peeled off just by touching the coated surface. Comparative example 2 A paint in which titanium dioxide was dispersed in an acrylic resin according to the paint composition shown in Table 5 was applied to an aluminum plate. The acrylic resin film was peeled off by irradiation with ultraviolet rays for 500 hours using a Dew panel optical control weather meter manufactured by Suga Test Instruments Co., Ltd. Comparative example 3 A paint in which titanium dioxide was dispersed in a urethane resin according to the paint composition shown in Table 5 was applied to an aluminum plate. The urethane resin film was peeled off by irradiation with ultraviolet rays for 200 hours using a Dew Panel optical control weather meter manufactured by Suga Test Instruments Co., Ltd. Comparative example 4 An aluminum plate coated with a paint in which titanium dioxide was dispersed in melamine and an alkyd resin had no aldehyde decomposition effect.

【0025】

[table 1]

<img file="JPH09613A_D0001.tif" /><img file="JPH09613A_D0002.tif" />【0026】

[Table 2]

<img file="JPH09613A_D0003.tif" />【0027】

[Table 3]

<img file="JPH09613A_D0004.tif" /><img file="JPH09613A_D0005.tif" />【0028】

[Table 4]

<img file="JPH09613A_D0006.tif" /><img file="JPH09613A_D0007.tif" />【0029】

[Table 5]

<img file="JPH09613A_D0008.tif" /><img file="JPH09613A_D0009.tif" />【0030】

[Table 6]

<img file="JPH09613A_D0010.tif" />【0031】

[Table 7]

<img file="JPH09613A_D0011.tif" />