JP2010005611A - Article coated with photocatalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an article coated with a photocatalyst that exhibits an excellent antifungal capacity while preventing the deterioration of its substrate for a long time and is free from a coloration problem when adding or using. <P>SOLUTION: The article coated with a photocatalyst constituted of a substrate, an intermediate layer disposed on the substrate, and a photocatalyst layer disposed on the intermediate layer, is characterized in that the photocatalyst layer comprises ionized elemental copper and photocatalyst particles including a metal oxide excited by ultraviolet rays, and the intermediate layer comprises a weather resistant resin and a hydroxyphenyltriazine compound. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention is a photocatalyst coating provided with a photocatalyst layer that is particularly suitable for applications such as exterior materials and interior materials such as buildings, and is excellent in high weather resistance, anti-algae properties, mildew-proof properties, light resistance and various film performances. About the body.

  In recent years, photocatalysts such as titanium oxide have been used in many applications such as exterior and interior materials for buildings. For exterior applications, by applying a photocatalyst to the substrate surface, it is possible to impart decomposition functions such as anti-algae and anti-fungal functions such as roofs using light energy. For interior use, it is possible to impart decomposition functions such as an alga-proof and anti-mold function to the inner wall agent and the like.

  When obtaining such a photocatalyst-coated body, an intermediate layer is provided between the base material serving as the base and the photocatalyst for the purpose of adhesion and / or suppression of deterioration of the base material surface due to the photocatalyst. The following are known as techniques for obtaining a photocatalyst-coated body coated with such a photocatalyst.

  A technique is known in which an intermediate layer such as a silicone-modified resin is provided between a base material serving as a base and a photocatalyst for the purpose of adhesion and / or suppression of deterioration of the base material surface by the photocatalyst. (For example, refer to Patent Document 1 (International Publication No. 97/00134 pamphlet)).

  In addition, an intermediate layer is provided between the base substrate and the photocatalyst, and an ultraviolet absorbing material such as an inorganic semiconductor, salicylic acid-based, benzophenone-based, benzotriazole-based, or cyanoacrylate-based organic material is blended in the intermediate layer. Further, techniques for suppressing deterioration of the substrate surface are also known (see, for example, Patent Document 2 (Japanese Patent Laid-Open No. 2006-116461) and Patent Document 3 (Japanese Patent Laid-Open No. 2008-272718)).

A technique for obtaining a photocatalyst by forming a coating film containing silica sol as a binder component of a photocatalyst layer and photocatalytic titanium dioxide on a substrate is also known (for example, Japanese Patent Application Laid-Open No. 11-169727). reference). In this technique, the amount of silica sol added is ₂₀ to 200 parts by weight with respect to titanium dioxide on the basis of SiO ₂ , and the content ratio of titanium dioxide is high. In addition, the particle size of silica sol is as small as 0.1 to 10 nm.

  In addition, a technique for adding a binder component such as hydrolyzable silicone to the photocatalyst for the purpose of enhancing the durability of the coated body is known. (See Patent Document 5 (Japanese Patent Laid-Open No. 2001-212510)), (See Patent Document 6 (Japanese Patent Laid-Open No. 2002-137322)).

  In addition, a technique for adding copper to a photocatalyst to improve antibacterial and antifungal properties is also known (see Patent Document 7 (Japanese Patent Laid-Open No. 6-65012)).

WO97 / 00134 pamphlet JP 2006-116461 A JP 2008-272718 A JP 11-169727 A JP 2001-212510 A JP 2002-137322 A JP-A-6-65012 Japanese Patent No. 4092434 JP 2008-307528 A

  In order to increase the photocatalytic activity, the amount of the photocatalyst contained in the photocatalyst layer has been conventionally increased. However, in that case, there is a concern that the base material may be deteriorated by the photocatalyst. there were. Further, if the amount of the photocatalyst is simply reduced, it becomes difficult to obtain sufficient photocatalytic activity, and the ultraviolet shielding effect in the photocatalyst layer is weakened, and there is a concern about deterioration of the substrate and the like due to ultraviolet rays. Therefore, it has been conventionally used to use an ultraviolet absorber. However, when an inorganic ultraviolet absorber is used, a large amount of addition is required to obtain a sufficient effect, and there is a problem that coloring, devitrification, and the like are caused by the addition. In addition, when an organic ultraviolet absorber such as a triazole compound is used, there is a problem that discoloration occurs during use particularly when copper is added in order to increase the antifungal activity by the photocatalyst.

  In the present invention, in view of the above circumstances, to provide a photocatalyst-coated body that does not cause coloring problems during addition and use while preventing deterioration of the base material for a long time while exhibiting excellent antifungal performance. Objective.

  That is, the photocatalyst-coated body according to the present invention is a photocatalyst-coated body comprising a base material, an intermediate layer provided on the base material, and a photocatalyst layer provided on the intermediate layer. Includes photocatalyst particles made of metal oxides excited by ultraviolet rays and copper element in an ionic state, and the intermediate layer contains a weather resistant resin and a hydroxyphenyltriazine compound. It is a featured photocatalyst-coated body.

Photocatalyst-coated body A photocatalyst-coated body according to the present invention is a photocatalyst-coated body comprising a base material, an intermediate layer provided on the base material, and a photocatalyst layer provided on the intermediate layer, the photocatalyst layer Contains photocatalyst particles made of metal oxides excited by ultraviolet rays and copper element in an ionic state, and the intermediate layer contains a weather resistant resin and a hydroxyphenyltriazine compound Is a photocatalyst-coated body.
That is, the photocatalyst-coated body according to the present invention does not cause coloring problems during addition and use while exhibiting excellent antifungal performance and preventing deterioration of the base material for a long period of time.

In a preferred embodiment of the present invention, the content of the photocatalyst particles contained in the photocatalyst layer is more than 1% by mass and less than 20% by mass, more preferably more than 1% by mass and less than 5% by mass. .
By making it within the above range, it is possible to effectively exhibit the decomposition function of the photocatalyst and to improve the weather resistance of the base material and the intermediate layer to such an extent that it can withstand long-term use in the tropics and the like. It is also possible to suppress deterioration of the base material and the intermediate layer due to. That is, it is possible to simultaneously exhibit an ultraviolet absorption function in the photocatalyst layer and an excellent photocatalyst function under sunlight irradiation in the temperate and subarctic regions and sufficient weather resistance.

  In a preferred embodiment of the present invention, a hindered amine compound is contained. By including a hindered amine compound as a light stabilizer, the absorption performance of ultraviolet rays having a short wavelength of less than 380 nm by the hydroxyphenyltriazine compound is stabilized.

  In a preferred embodiment of the present invention, the weather resistant resin is a silicone-modified resin. By using the silicone-modified resin, the intermediate layer can simultaneously exhibit weather resistance and crack resistance.

In a preferred embodiment of the present invention, the silicon content in the silicone-modified resin is 0.2% by mass or more and less than 16.5% by mass, more preferably 6.5% by mass with respect to the solid content of the silicone-modified resin. The amount is made less than 16.5% by mass.
By doing so, weather resistance to ultraviolet rays in the intermediate layer and erosion by the photocatalyst can be sufficiently suppressed, and generation of cracks can be suppressed.
Here, the silicon atom content in the silicone-modified resin can be measured by chemical analysis using an X-ray photoelectron spectrometer (XPS).

In a preferred embodiment of the present invention, the hydroxyphenyl triazine compound is contained in an amount of 0.1% by mass or more and less than 10% by mass with respect to the intermediate layer.
By setting it within this range, the ultraviolet ray absorbing performance is sufficiently exhibited without causing the intermediate layer to be discolored.

  The hydroxyphenyl triazine compound used in the present invention is a derivative of hydroxyphenyl triazine and / or hydroxyphenyl triazine having a basic skeleton represented by the following general formula (Chemical Formula 1), and a commercially available hydroxyphenyl triazine-based UV absorber is preferable. Can be used.

In a preferred embodiment of the present invention, the photocatalyst layer has air permeability.
By doing so, the contact opportunity of photocatalyst particle and harmful gas increases, and comes to exhibit the outstanding photocatalyst decomposition function.

In a preferred embodiment of the present invention, the photocatalyst layer contains inorganic oxide particles in addition to the photocatalyst particles.
By making the main component of the binder component other than the photocatalyst particles into a particulate inorganic oxide, sufficient air permeability can be secured in the photocatalyst layer, the opportunity for contact between the photocatalyst particles and harmful gas increases, and an excellent photocatalytic decomposition function. To come out.

In a preferred embodiment of the present invention, the photocatalyst layer is hydrolyzable as an optional component, with photocatalyst particles exceeding 1 part by mass and less than 20 parts by mass, inorganic oxide particles exceeding 70 parts by mass and less than 99 parts by mass. At least one selected from the group consisting of a polycondensation product of silicone and a polycondensation product of a hydrolyzate of an organometallic compound is used in an amount of 0 to 10 parts by mass, the photocatalyst particles, the inorganic oxide particles, and the optional It is made to contain so that the total amount of the component oxide conversion amount may be 100 mass parts.
By doing so, the chances of contact between the photocatalyst particles and harmful gas increase, effectively exhibiting the excellent photocatalytic decomposition function, and the weather resistance of the substrate and intermediate layer can withstand long-term use in the tropics and the like It is possible to improve to a certain extent, and it is also possible to suppress deterioration of the base material and intermediate layer due to the photocatalyst.

In a preferred embodiment of the present invention, the photocatalyst layer is hydrolyzable as an optional component, with photocatalyst particles exceeding 1 part by mass and less than 5 parts by mass, inorganic oxide particles exceeding 85 parts by mass and less than 99 parts by mass. At least one selected from the group consisting of a polycondensation product of silicone and a polycondensation product of a hydrolyzate of an organometallic compound is used in an amount of 0 to 10 parts by mass, the photocatalyst particles, the inorganic oxide particles, and the optional It is made to contain so that the total amount of the component oxide conversion amount may be 100 mass parts.
By doing so, the chances of contact between the photocatalyst particles and harmful gas increase, effectively exhibiting the excellent photocatalytic decomposition function, and the weather resistance of the substrate and intermediate layer can withstand long-term use in the tropics and the like It is possible to improve to a certain extent, and it is also possible to suppress deterioration of the base material and intermediate layer due to the photocatalyst.

Photocatalyst layer The photocatalyst layer of the present invention contains photocatalyst particles made of a metal oxide excited by ultraviolet rays and an ionic copper element.

  The photocatalyst sol of the present invention is basically composed of photocatalyst particles made of a metal oxide, an amine, and a solvent.

  As the photocatalyst particles, metal oxide particles such as anatase-type titanium oxide, rutile-type titanium oxide, brookite-type titanium oxide, tin oxide, zinc oxide, strontium titanate, tungsten oxide, and cerium oxide can be suitably used. .

  According to a preferred embodiment of the present invention, the photocatalyst particles preferably have an average particle size of 10 nm or more and less than 100 nm, more preferably 10 nm or more and 60 nm or less. The average particle diameter is calculated as a number average value obtained by measuring the length of any 100 particles that enter a 200,000-fold field of view with a scanning electron microscope.

  As the shape of the particle, a true sphere is the best, but it may be approximately circular or elliptical, and the length of the particle in this case is approximately calculated as ((major axis + minor axis) / 2). Within this range, weather resistance, harmful gas decomposability, and various desired coating properties (transparency, coating strength, etc.) are efficiently exhibited.

  Furthermore, it is more preferable that the linear transmittance of the photocatalyst layer at a wavelength of 550 nm is secured to 90% or more, more preferably 95% or more. By doing so, it becomes possible to express without impairing the color and design of the groundwork. Moreover, even if it is coated on highly transparent glass or plastic, the transparency is not impaired.

  In the present invention, the photocatalytic layer further contains an ionic copper element. The valence may be +1 or +2. The addition amount of the copper element contained in the photocatalyst layer is preferably 0.5 parts by mass to 5% by mass in terms of CuO with respect to the photocatalyst particles.

  According to a preferred embodiment of the present invention, at least one metal selected from the group consisting of vanadium, iron, cobalt, nickel, palladium, zinc, ruthenium, rhodium, silver, platinum and gold is used to develop higher photocatalytic ability. And / or a metal compound composed of the metal can be added to a photocatalyst coating liquid applied on the intermediate layer to form a photocatalyst layer or a photocatalyst layer. This addition can be performed by any method such as a method in which the metal or metal compound is mixed and dissolved or dispersed in a coating solution, or a method in which the metal or metal compound is supported on a photocatalyst layer or photocatalyst particles.

  In the present invention, it is preferable that inorganic oxide particles are contained in the photocatalyst layer. The inorganic oxide particles are not particularly limited as long as they are inorganic oxide particles capable of forming a layer together with the photocatalyst particles, and any kind of inorganic oxide particles can be used. Examples of such inorganic oxide particles include silica, alumina, zirconia, ceria, yttria, tin oxide, iron oxide, manganese oxide, nickel oxide, cobalt oxide, hafnia and other single oxide particles; and titanic acid Examples include particles of complex oxides such as barium, calcium silicate, aluminum borate, and potassium titanate, and silica particles are more preferable. These inorganic oxide particles are preferably in the form of an aqueous colloid using water as a dispersion medium; or an organosol dispersed in a hydrophilic solvent such as ethyl alcohol, isopropyl alcohol, or ethylene glycol, and particularly preferably. Colloidal silica.

  The inorganic oxide particles have an average particle diameter of more than 5 nm and not more than 20 nm, preferably not less than 10 nm and not more than 20 nm. The average particle diameter is calculated as a number average value obtained by measuring the length of any 100 particles that enter a 200,000-fold field of view with a scanning electron microscope. As the shape of the particle, a true sphere is the best, but it may be approximately circular or elliptical, and the length of the particle in this case is approximately calculated as ((major axis + minor axis) / 2). Within this range, weather resistance, harmful gas decomposability, and various desired coating properties (transparency, coating strength, etc.) are efficiently exhibited, and in particular, a photocatalyst layer that is transparent and has good adhesion can be obtained. Not only can a film that is strong against sliding wear be obtained.

  In order to ensure air permeability, the photocatalyst layer of the present invention preferably does not substantially contain a hydrolyzable silicone condensation polymer, and more preferably does not contain it at all. Here, the hydrolyzable silicone is a general term for an organosiloxane having an alkoxy group and / or a partially hydrolyzed condensate thereof. The content of the hydrolyzable silicone polycondensate is 0 to 10 parts by mass with respect to 100 parts by mass of the total amount of photocatalyst particles, inorganic oxide particles, and hydrolyzable silicone polycondensate in terms of silica. Is preferably 5 parts by mass or less, and most preferably 0 part by mass. As the hydrolyzable silicone, a silicone compound having 2 to 4 functional silane as a monomer unit is often used, and for example, ethyl silicate, methyl silicate, alkyl group-containing silicone, phenyl group-containing silicone and the like can be suitably used.

  In order to ensure air permeability, the photocatalyst layer of the present invention preferably contains substantially no polycondensate of a hydrolyzate of an organometallic compound, and more preferably does not contain at all. Here, the organometallic compound is a metal alkoxide containing a metal element such as titanium, zirconium, or aluminum, a metal organic complex, or the like. The content of the polycondensation product of the hydrolyzate of the organic metal is 0 parts by mass or more and 10 parts by mass with respect to 100 parts by mass of the total amount of photocatalyst particles, inorganic oxide particles, and hydrolyzable silicone in terms of metal oxide. Is preferably 5 parts by mass or less, and most preferably 0 part by mass.

  The photocatalyst layer of the present invention comprises at least one selected from the group consisting of a hydrolyzable silicone polycondensate and an organometallic compound hydrolyzate as an optional component. The content of the optional component is preferably 0 parts by mass or more and less than 10 parts by mass with respect to 100 parts by mass of the total amount of the photocatalyst particles, the inorganic oxide particles, and the oxide conversion amount of these optional components, Preferably it is 5 mass parts or less, Most preferably, it is 0 mass part.

  The photocatalyst layer preferably has a thickness of 0.1 μm to 5.0 μm, more preferably 0.5 μm to 3.0 μm, and most preferably 1.0 μm to 2.0 μm. is there. Within such a range, the photocatalyst particles having a lower content ratio than the inorganic oxide particles can be increased in the film thickness direction, so that the harmful gas decomposability is improved. Furthermore, excellent characteristics can be obtained in terms of transparency.

  The photocatalyst-coated body of the present invention is easily produced by applying a photocatalyst coating liquid containing a photocatalyst particle composed of a metal oxide excited by ultraviolet rays and a copper compound onto a substrate having an intermediate layer. be able to. As a method for coating the photocatalyst layer, generally used methods such as brush coating, roller, spray, roll coater, flow coater, dip coating, flow coating, and screen printing can be used. After applying the coating liquid to the substrate, it may be dried at room temperature, or may be heat-dried as necessary.

  In addition, as a solvent of a photocatalyst coating liquid, all the solvents which can disperse | distribute the said component appropriately can be used, and may be water and / or an organic solvent. Moreover, the solid content concentration of the photocatalyst coating liquid is not particularly limited, but it is preferably 1 to 10% by mass because it is easy to apply. The components in the photocatalyst coating composition are analyzed by separating the coating solution into particle components and filtrate by ultrafiltration, and analyzing each by infrared spectroscopic analysis, gel permeation chromatography, fluorescent X-ray spectroscopic analysis, etc. It can be evaluated by analyzing the spectrum.

  The photocatalyst coating liquid may contain a surfactant as an optional component. The surfactant used in the present invention may be contained in the photocatalyst layer in an amount of 0 to less than 10 parts by mass with respect to 100 parts by mass of the total amount of photocatalyst particles, inorganic oxide particles, and hydrolyzable silicone, Preferably they are 0 mass part or more and 8 mass parts or less, More preferably, they are 0 or more and 6 mass parts or less. One of the effects of the surfactant is leveling to the substrate, and the amount of the surfactant may be appropriately determined within the above-mentioned range depending on the combination of the coating liquid and the substrate, and the lower limit at that time is 0 It may be 1 part by mass. This surfactant is an effective component for improving the wettability of the photocatalyst coating solution, but in the photocatalyst layer formed after coating, it is an inevitable impurity that no longer contributes to the effect of the photocatalyst-coated body of the present invention. Equivalent to. Therefore, it may be used within the above-mentioned content range depending on the wettability required for the photocatalyst coating liquid, and if the wettability is not a problem, the surfactant may be contained substantially or not at all. The surfactant to be used can be appropriately selected in consideration of the dispersion stability of the photocatalyst and inorganic oxide particles, and wettability when applied on the intermediate layer, but a nonionic surfactant is preferable, More preferably, an ether type nonionic surfactant, an ester type nonionic surfactant, a polyalkylene glycol nonionic surfactant, a fluorine-based nonionic surfactant, or a silicon-based nonionic surfactant is used. Can be mentioned.

  The contents described in the above-mentioned sections “photocatalyst layer” and “photocatalyst-coated body” can be arbitrarily combined.

Intermediate Layer The intermediate layer of the present invention contains a weather resistant resin and a hydroxyphenyltriazine compound as essential components.

  The weather resistant resin is not particularly limited as long as it has good compatibility with the ultraviolet absorber, has adhesion to the base material, and adhesion to the photocatalyst, and can suppress deterioration of the intermediate layer surface due to the photocatalyst. Silicone-modified resins such as silicone-modified acrylic resins, silicone-modified epoxy resins, silicone-modified urethane resins, and silicone-modified polyesters containing polysiloxane in the resin are suitable. When applied to exterior building materials, silicone-modified acrylic resins are more suitable from the viewpoint of weather resistance. In the silicone-modified acrylic resin, it is more preferable to use a mixture of two liquids of a silicone-modified acrylic resin having a carboxyl group and a silicone resin having an epoxy group from the viewpoint of improving the strength of the coating film.

  Although the dry film thickness of an intermediate | middle layer is not specifically limited, Preferably they are 1 micrometer-50 micrometers, More preferably, they are 1 micrometer-10 micrometers. If the thickness is less than 1 μm, the effect of suppressing degradation of the intermediate layer and the substrate by the photocatalyst may be inferior. When it is thicker than 50 μm, although it depends on the type of the intermediate layer, there is a possibility that fine cracks may occur after drying.

It is also possible to mix extender pigments, colored pigments, algaeproofing agents and the like as optional components in the intermediate layer.
As the extender pigment, for example, titanium oxide whisker, calcium carbonate whisker, aluminum borate whisker, potassium titanate whisker, mica, talc and the like can be suitably used.
Examples of the color pigment include titanium oxide white, zinc oxide white iron oxide, carbon black, spinel green, bengara, cobalt aluminate, ultramarine blue and the like, phthalocyanine series, benzimidazolone series, isoindolinone series, azo Organic color pigments such as those based on anthraquinone, quinophthalone, anthrapyridinine, quinacridone, toluidine, pyrathrone, and perylene can be suitably used.
As the anti-algae, organic anti-fungal agents having good compatibility with the resin component of the intermediate layer can be suitably used. For example, organic nitrogen sulfur compounds, pyrithion compounds, organic iodine compounds, triazine compounds, isothiazolines A compound, an imidazole compound, a pyridine compound, a nitrile compound, a thiocarbamate compound, a thiazole compound, a disulfide compound, or the like can be suitably used.

  The contents described in the above-mentioned “intermediate layer”, “photocatalyst-coated body”, and “photocatalyst layer” can be arbitrarily combined.

Intermediate Layer Manufacturing Method The intermediate layer can be easily manufactured by applying an intermediate layer coating solution onto the substrate. As a method for coating the intermediate layer, generally used methods such as brush coating, roller, spray, roll coater, flow coater, dip coating, flow coating, and screen printing can be used. After applying the coating liquid to the substrate, it may be dried at room temperature, or may be heat-dried as necessary.

  The intermediate layer coating solution basically contains a weather resistant resin or a precursor before polymerization thereof, and a hydroxyphenyltriazine compound.

  As the “weather resistant resin”, those described in the above “photocatalyst layer” and “photocatalyst-coated body” can be suitably used.

  As the solvent for the intermediate layer coating liquid, any solvent that can appropriately disperse the above components can be used, and water and / or an organic solvent may be used. The solid content concentration of the intermediate layer coating solution of the present invention is not particularly limited, but it is preferably 10 to 20% by mass in terms of easy application. In addition, the analysis of the structural component in an intermediate | middle layer coating liquid can be evaluated by infrared spectroscopy about a resin component.

  In addition to the above, “intermediate pigment”, “colored pigment”, “algae-proofing agent”, etc. may also be added to the intermediate layer coating solution, which is also described in the above “intermediate layer” section Can be suitably used.

  In addition to the above, the intermediate layer coating solution may contain paint additives such as pigment dispersants, antifoaming agents, and antioxidants, and other components usually included in paints. Further, a matting agent such as silica fine particles may be included.

Base Material The base material used in the present invention may be any material, regardless of inorganic material or organic material, as long as the intermediate layer can be formed thereon, and the shape is not limited. Preferred examples of the substrate from the viewpoint of materials include metals, ceramics, glass, plastics, rubber, stones, cement, concrete, fibers, fabrics, wood, paper, combinations thereof, laminates thereof, Examples thereof include those having at least one layer of coating on the surface. Preferred examples of base materials from the viewpoint of applications include building materials, building exteriors and interiors, window frames, window glass, structural members, exteriors and coatings of vehicles, exteriors of machinery and articles, dust covers and coatings, traffic signs, Various display devices, advertising towers, sound insulation walls for roads, sound insulation walls for railways, bridges, guard rail exteriors and paintings, tunnel interiors and paintings, insulators, solar cell covers, solar water heater heat collection covers, plastic houses, vehicle lighting Covers, outdoor lighting fixtures, tables, bathroom materials, kitchen panels, sinks, ranges, ventilation fans, air conditioning, filters, toilets, bathtubs, and films, sheets, seals and the like for attachment to the surface of the article.

  The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples.

<Preparation of painted body sample>
Examples and comparative examples were produced as follows.
Example 1:
Base material: Glass base material Intermediate layer: Silicone-modified acrylic resin dispersion having a silicon atom content of 10% by weight based on the solid content of the silicone-modified resin, and 1% by weight of hydroxyphenyltriazine based on the solid content of the dispersion An intermediate layer coating solution containing the compound and 1% by mass of a hindered amine light stabilizer was spray coated and dried at 120 ° C. to form an intermediate layer having a thickness of 10 μm.
Photocatalyst layer: Anatase-type titanium oxide aqueous dispersion (average particle size: about 50 nm) in which 0.5% by mass of a copper compound is added to TiO _{2 in} terms of CuO, and water-dispersed colloidal silica (average particle size: about 30 nm) ) And a polyether-modified silicone surfactant were mixed to obtain a photocatalyst coating solution. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass. The obtained photocatalyst coating liquid was spray-coated on the intermediate layer-coated body heated in advance and dried at 120 ° C. Titanium oxide in the obtained photocatalyst layer was 2 parts by mass, silica was 98 parts by mass, and the surfactant was 6 parts by mass. The film thickness of the photocatalyst layer was 0.5 μm.

Example 2: In Example 1 above, the amount of titanium oxide in the photocatalyst layer was 15 parts by mass, and the silica was 85 parts by mass.
Example 3 In the above Example 1, the amount of titanium oxide in the photocatalyst layer was 4 parts by mass, and the silica was 96 parts by mass.
Example 4: In the first embodiment, as titanium oxide, 0.35 wt% with respect to TiO ₂ a copper compound in terms of CuO, was added 0.15 wt% with respect to TiO2 silver compound Ag ₂ O in terms An anatase-type titanium oxide aqueous dispersion (average particle diameter: about 50 nm) was used.
Example 5: In Example 2, as titanium oxide, 0.35 wt% with respect to TiO ₂ a copper compound in terms of CuO, 0.15 wt% with respect to TiO ₂ silver compound Ag ₂ O in terms of added An anatase-type titanium oxide aqueous dispersion (average particle size: about 50 nm) was used.
Example 6: In Example 3 above, as titanium oxide, a copper compound was added in an amount of 0.35% by mass with respect to TiO _{2 in} terms of CuO, and a silver compound was added in an amount of 0.15% by mass with respect to TiO _{2 in} terms of Ag ₂ O. An anatase-type titanium oxide aqueous dispersion (average particle size: about 50 nm) was used.

Comparative Example 1: In Example 1 above, a triazole compound was used in place of the hydroxyphenyl triazine compound in the intermediate layer.

<Evaluation>
About the obtained sample, photocatalytic decomposition activity by BLB of 30 W / m ² , long-term deterioration acceleration test by repeated irradiation of xenon lamp (irradiance 80 W / m ^{2 of} wavelength 300 to 400 nm) and spray of 1% hydrogen peroxide Carried out. The evaluation results are shown in Table 1.

Claims (11)

A photocatalyst-coated body comprising a base material, an intermediate layer provided on the base material, and a photocatalyst layer provided on the intermediate layer,
The photocatalyst layer contains photocatalyst particles made of a metal oxide excited by ultraviolet rays and copper element in an ionic state,
The intermediate layer contains a weather resistant resin and a hydroxyphenyltriazine compound.   The photocatalyst-coated body according to claim 1, wherein the content of the photocatalyst particles contained in the photocatalyst layer is 1% by mass or more and less than 20% by mass.   2. The photocatalyst-coated body according to claim 1, wherein the content of the photocatalyst particles contained in the photocatalyst layer is more than 1% by mass and less than 5% by mass.   The photocatalyst-coated body according to any one of claims 1 to 3, wherein the intermediate layer further contains a hindered amine compound.   The photocatalyst-coated body according to any one of claims 1 to 4, wherein the weather-resistant resin is a silicone-modified resin.   The photocatalyst-coated body according to claim 5, wherein the silicon content in the silicone-modified resin is 0.2% by mass or more and less than 16.5% by mass with respect to the solid content of the silicone-modified resin.   The photocatalyst-coated body according to any one of claims 1 to 6, wherein the hydroxyphenyltriazine compound is contained in an amount of 0.1 mass% or more and less than 10 mass% with respect to the intermediate layer.   The said photocatalyst layer has air permeability, The photocatalyst coating body of any one of Claims 1-6 characterized by the above-mentioned.   The photocatalyst-coated body according to any one of claims 1 to 8, wherein the photocatalyst layer contains inorganic oxide particles in addition to the photocatalyst particles. The photocatalytic layer is
The photocatalyst particles of more than 1 part by weight and less than 20 parts by weight;
Greater than 70 parts by weight and less than 99 parts by weight of the inorganic oxide particles;
As an optional component, at least one selected from the group of hydrolyzable silicone polycondensate and organometallic hydrolyzate polycondensate is 0 to 10 parts by mass,
The photocatalyst-coated body according to claim 9, comprising a total amount of the photocatalyst particles, the inorganic oxide particles, and the oxide-converted amount of the optional component of 100 parts by mass. The photocatalytic layer is
The photocatalyst particles of more than 1 part by weight and less than 5 parts by weight;
Greater than 85 parts by weight and less than 99 parts by weight of the inorganic oxide particles;
As an optional component, at least one selected from the group of hydrolyzable silicone polycondensate and organometallic hydrolyzate polycondensate is 0 to 10 parts by mass,
The photocatalyst-coated body according to claim 9 or 10, comprising a total amount of the photocatalyst particles, the inorganic oxide particles, and the oxide-converted amount of the optional component of 100 parts by mass.