JP2009136868A - Photocatalyst-coated body and photocatalyst coating liquid therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocatalyst composite material having an excellent alga-proof property, good performance when used for decomposing toxic gasses such as NOx, and also excellent weatherability. <P>SOLUTION: A photocatalyst-coated body being the photocatalyst composite material has such a structure that an organic mildewproofing agent-containing intermediate layer and a photocatalyst layer are formed on a base material. The photocatalyst layer comprises a photocatalyst particle of ≥1 part mass and <20 parts mass, an inorganic oxide particle of >70 parts mass and ≤99 parts mass, a copper element, a silver element and, as an optional component, dried hydrolyzable silicone of ≥0 and <10 parts mass in terms of silica so that the total amount of the photocatalyst particle, the inorganic oxide particle and the dried hydrolyzable silicone in terms of silica is 100 parts mass. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photocatalyst-coated body that exhibits excellent effects such as antifouling properties, decomposability of harmful substances, and inhibition of mold and algae growth.

  In recent years, photocatalysts such as titanium oxide have been used in many applications such as exterior materials for buildings. By coating a photocatalyst on the surface of the substrate, it is possible to provide a self-cleaning function, a function of decomposing harmful substances such as NOx and SOx, and a function of suppressing the growth of fungi and algae using light energy. 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. In this intermediate layer, in order to supplement the function to suppress the growth of mold and algae by photocatalyst, in order to ensure the ability to suppress the growth of mold and algae, especially in areas where the photocatalytic function is difficult to express, such as shade, An example of adding an organic fungicide can be seen. 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, a technique for adding an organic antifungal agent to such an intermediate layer in order to complement the function of suppressing the growth of mold and algae of the photocatalyst is known (Patent Document 2 (Japanese Patent Laid-Open No. 2001-232215)). reference)).

  A technique is known in which metallic silver and metallic copper or ions thereof are added to a photocatalyst layer to impart a deodorizing, antibacterial, and antifungal function (see Patent Document 3 (Japanese Patent No. 3559892)).

  A technique for increasing the photocatalytic activity by adding silver, copper, zinc, platinum or the like to the photocatalyst layer is known (see Patent Document 4 (Japanese Patent Laid-Open No. 11-169726)), (Patent Document 5 (International Publication No. 00 / No. 06300 pamphlet)).

  A technique for adding a binder component such as hydrolyzable silicone to the photocatalyst layer is known for the purpose of enhancing the durability of the coated body. (See Patent Document 6 (Japanese Patent Laid-Open No. 2000-212510)), (See Patent Document 7 (Japanese Patent Laid-Open No. 2002-137322)).

WO97 / 00134 pamphlet JP 2001-232215 A Japanese Patent No. 355992 JP-A-11-169726 International Publication No. 00/06300 Pamphlet Japanese Patent Laid-Open No. 2000-212510 JP 2002-137322 A

  When hydrolyzable silicone is added as a binder component to the photocatalyst layer, the hydrolyzable silicone forms a dense film, so that the voids between the particles constituting the photocatalyst layer are blocked. As a result, the elution rate of the fungicide added to the intermediate layer is reduced, and there is a concern that a problem that the purpose of supplementing the anti-algae and fungicide functions cannot be achieved. Furthermore, depending on the amount of hydrolyzable silicone added, there is a concern that the function inherent to the photocatalyst may be lost, for example, the diffusion rate of the gas that permeates the photocatalyst layer decreases and the harmful gas decomposition function of the photocatalyst decreases.

  In order to obtain sufficient photocatalytic activity, the amount of photocatalyst contained in the photocatalyst layer has been conventionally increased. However, in such a coating film structure, the intermediate layer may be deteriorated by the photocatalyst. In addition, there is a concern that the organic antifungal agent contained in the intermediate layer is decomposed, causing problems such as the algae prevention by the photocatalyst and the purpose of complementing the antifungal function cannot be achieved.

  Therefore, the present invention achieves both the original functions of a photocatalyst such as antialgae, antifungal, harmful gas decomposability, super hydrophilicity, the weather resistance of the coating and the strength of the coating, as well as antialgae and antifungal performance. It aims at providing the composite material which has a photocatalyst which does not prevent the elution of the organic algaeproofing agent which complements.

In order to solve the above problems, 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,
The intermediate layer comprises an organic antifungal agent;
The photocatalytic layer is
1 to 20 parts by mass of photocatalyst particles,
70 to 99 parts by mass of inorganic oxide particles,
A hydrolyzable silicone dry matter having a weight of 0 to less than 10 parts by weight in terms of silica, and the total amount of silica equivalents of the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone is 100 parts by weight. Including
In addition, containing copper element and silver element,
The photocatalyst layer has gaps between particles.

  Furthermore, the preferable aspect of this invention is a set of the photocatalyst coating liquid and the coating liquid for forming an intermediate | middle layer. By combining the coating liquid, it is possible to easily form a painted body.

  According to the present invention, since the elution of the organic antifungal agent added to the intermediate layer is not hindered, the purpose of supplementing the photocatalytic antialgal and antifungal functions can be sufficiently achieved. Further, since the diffusion of the gas component that permeates the photocatalyst layer is not hindered, the harmful gas decomposition function by the photocatalyst works effectively. Furthermore, the coating film of the present invention is also excellent in weather resistance and strength, and can exhibit a high degree of antialgae and antifungal properties due to the copper element and the silver element.

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 layer comprises an organic fungicide and
The photocatalytic layer is
1 to 20 parts by mass of photocatalyst particles,
70 to 99 parts by mass of inorganic oxide particles,
A hydrolyzable silicone dry product of 0 to 10 parts by mass in terms of silica,
The total amount of the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone in terms of silica is 100 parts by mass, and further contains copper element and silver element. It is characterized by the presence of gaps between particles.

  Since the photocatalyst layer contains only a small amount of hydrolyzable silicone and is substantially composed of particles, it does not hinder the elution of the organic antifungal agent added to the intermediate layer. Can be fulfilled. In addition, since the diffusion of gas components is not hindered, the function of decomposing harmful gases such as NOx and SOx also works effectively despite the small amount of photocatalyst.

  In the present invention, the reason why these several excellent effects are realized at the same time is not clear or is considered as follows. However, the following description is merely a hypothesis, and the present invention is not limited by the following hypothesis. First, since the photocatalyst layer is basically composed of two types of particles, photocatalyst particles and inorganic oxide particles, there are abundant gaps between the particles. When a large amount of hydrolyzable silicone widely used as a binder for the photocatalyst layer is used, it is considered that the gap between the particles is densely filled, and thus gas diffusion is hindered. However, the photocatalyst layer of the present invention does not contain hydrolyzable silicone or even if it contains 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, It is considered that a sufficient gap between particles can be secured. And by such a gap, an organic antifungal agent contained in the intermediate layer, a structure in which noxious gases such as NOx and SOx easily diffuse into the photocatalyst layer is realized, and as a result, the organic mold agent acts effectively, It is thought that harmful gas is efficiently contacted with the photocatalyst particles and decomposed by the photocatalytic activity.

  At the same time, the proportion of photocatalyst particles is considerably smaller than that of inorganic oxide particles, so that direct contact of the photocatalyst particles with the intermediate layer can be minimized, thereby making it difficult to erode the intermediate layer. Conceivable.

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, window frames, window glass, structural members, exteriors and coatings of vehicles, exteriors of machinery and articles, dust covers and coatings, traffic signs, and various displays Equipment, 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 General exterior materials such as outdoor lighting fixtures, stands, and films, sheets, seals and the like for attaching to the article surface.

The resin used for the intermediate layer and the intermediate layer coating liquid intermediate layer has good compatibility with the organic antifungal agent, has adhesion to the substrate, and adhesion to the photocatalyst. Any silicone-modified resin such as silicone-modified acrylic resin, silicone-modified epoxy resin, silicone-modified urethane resin, and silicone-modified polyester containing polysiloxane in the resin is suitable as long as it can suppress deterioration. The silicone-modified resin has high weather resistance, and is excellent in adhesion to a substrate, particularly an organic substrate or a substrate whose surface is coated with an organic coating film. When applied to exterior building materials, silicone-modified acrylic resins are more suitable from the viewpoint of weather resistance.

  The silicone-modified resin preferably has a silicon atom content of 0.2% by mass or more and less than 16.5% by mass with respect to the solid content of the silicone-modified resin. When the silicon atom content contained in the silicone-modified resin is less than 0.2% by mass, that is, when the amount of the organic resin component is large, the weather resistance of the intermediate layer is lowered and the photocatalyst may be eroded. In addition, when the silicon atom content contained in the silicone-modified resin is 16.5% by mass or more, that is, when the silicone component is large, the properties of the intermediate layer are closer to the inorganic substance, so that the weather resistance is improved. The crack may occur in the intermediate layer.

  The silicon atom content in the silicone-modified resin can be measured by chemical analysis using an X-ray photoelectron spectrometer (XPS). Measuring instruments and conditions can be appropriately selected by those skilled in the art.

  An organic antifungal agent is added to the intermediate layer. In the present invention, any organic fungicide can be used as long as it has good compatibility with the intermediate layer. Examples include organic nitrogen sulfur compounds, pyrithione compounds, organic iodine compounds, triazine compounds, isothiazoline compounds, imidazole compounds, pyridine compounds, nitrile compounds, thiocarbamate compounds, thiazole compounds, organic iodine. Compounds and disulfide compounds may be mentioned and used alone or as a mixture. Since many antifungal agents generally have an effect of preventing algae, addition of the antifungal agent can be expected to suppress both mold and algae.

  Further, the same effect can be obtained by adding an organic algal / antifungal agent that has both an algal and fungicidal effect to the intermediate layer.

  The addition part by weight of the organic antifungal agent may be determined as appropriate by carrying out an optimum amount determined by the organic antifungal agent manufacturer or a simulated antifungal test.

The intermediate layer may additionally contain organic solvents, color pigments, extender pigments, pigment dispersants, antifoaming agents, UV absorbers, antioxidants and other paint additives, and other components usually included in paints. it can. Further, silica fine particles may be included as a matting agent.
The color pigment is not particularly limited, and examples thereof include inorganic pigments such as titanium dioxide, iron oxide, and carbon black, phthalocyanine series, benzimidazolone series, isoindolinone series, azo series, anthraquinone series, quinophthalone series, anthra Organic pigments such as pyridinin, quinacridone, toluidine, pyrathrone, and perylene can be used.

  The intermediate layer coating solution of the present invention can be obtained by dispersing the aforementioned silicone-modified resin and organic antifungal agent in a solvent. As the solvent, any solvent capable of appropriately dispersing the above components can be used, and it may be water or an organic solvent. 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. The analysis of the constituent components in the intermediate layer coating liquid is performed by infrared spectroscopic analysis for the resin component, and after being diluted or cured for the organic antifungal component, extracted with an appropriate solvent, and gel permeation. The analysis can be performed by chromatography and the spectrum can be analyzed.

Intermediate Layer Manufacturing Method The intermediate layer coated body of the present invention can be easily manufactured by applying the intermediate layer coating liquid of the present invention 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, screen printing, electrodeposition, vapor deposition and the like 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.

  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 it is thinner than 1 μm, the effect of suppressing deterioration of 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.

Photocatalyst layer and photocatalyst coating liquid therefor In the present invention, the photocatalyst layer is provided on the substrate, and the intermediate layer has 1 to 20 parts by mass of photocatalyst particles,
70 to 99 parts by mass of inorganic oxide particles,
Copper element, silver element,
The total amount of the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone in terms of silica becomes 100 parts by mass with respect to 0 to 10 parts by mass of the hydrolyzable silicone dry matter in terms of silica. As including.

The photocatalyst layer is formed from photocatalyst particles and inorganic oxide particles, and contains no or only a small amount of hydrolyzable silicone. Examples of the photocatalyst that can be used include metal oxides such as titanium oxide (TiO ₂ ), ZnO, SnO ₂ , SrTiO ₃ , WO ₃ , Bi ₂ O ₃ , and Fe ₂ O _{3. 2} ) is most preferred. Titanium oxide is harmless, chemically stable, and can be obtained at a lower cost than other substances having photocatalytic activity. Furthermore, titania has a high band gap energy, and therefore requires ultraviolet light for photoexcitation and does not absorb visible light in the process of photoexcitation, so that no color formation due to complementary color components occurs.

  Although titania can be obtained in various forms such as powder, sol, and solution, any form can be used as long as it exhibits photocatalytic activity. According to a preferred embodiment of the present invention, the photocatalyst particles preferably have an average particle size of 10 nm to 100 nm, more preferably 10 nm to 60 nm. Within this range, weather resistance, harmful gas decomposability, and various desired film properties (such as ultraviolet absorption, transparency, and film strength) are efficiently exhibited.

  This particle size 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 particle shape, a true sphere is most preferable, but a substantially circular or elliptical shape is also preferable. In this case, the particle length is approximately calculated as ((major axis + minor axis) / 2).

  The preferable content of titanium oxide particles in the photocatalyst layer and the coating liquid of the present invention is 1 part by mass or more with respect to 100 parts by mass as the total amount of titanium oxide particles, inorganic oxide particles, and hydrolyzable silicone in terms of silica. It is less than 20 parts by mass, more preferably more than 1 part by mass and 15 parts by mass or less. By reducing the blending ratio of the titanium oxide particles in this way, direct contact of the titanium oxide particles with the base material can be reduced as much as possible to prevent erosion of the base material (especially organic material) and weather resistance. It is thought that the property improves. Nevertheless, the functions resulting from the photocatalytic activity such as harmful gas decomposability can be sufficiently exhibited. Further, by setting the content of the titanium oxide particles to 5 parts by mass or more and 15 parts by mass or less, more preferably 5 parts by mass or more and 10 parts by mass or less, not only the functions due to the weather resistance and the photocatalytic activity described above, but also ultraviolet rays. Absorbability can also be exhibited sufficiently.

The inorganic oxide particles used in the present invention are not particularly limited as long as they are inorganic oxide particles capable of forming a layer together with photocatalyst particles, and any kind of inorganic oxide particles can be used. Examples of such inorganic oxide particles include single oxides such as silica, alumina, zirconia, ceria, yttria, boronia, magnesia, calcia, ferrite, amorphous titania, and hafnia, as well as barium titanate and silicic acid. A complex oxide such as calcium can be used. These inorganic oxides are preferably in the form of an aqueous colloid using water as a dispersion medium or an organosol dispersed in a colloidal form in a hydrophilic solvent such as ethyl alcohol, isopropyl alcohol or ethylene glycol.
According to a preferred embodiment of the present invention, the inorganic oxide particles are preferably silica. As the silica, colloidal silica dispersed in various solvents including water can be easily obtained.

  The preferred particle size of the inorganic oxide particles is an average particle size of more than 5 nm and not more than 40 nm, preferably more than 5 nm and not more than 30 nm, more preferably not less than 10 nm and not more than 30 nm, when formed in the form of an aqueous colloid or an organosol. . Within this range, weather resistance, harmful gas decomposability, and various desired film properties (such as ultraviolet absorption, transparency, and film strength) are efficiently exhibited. In particular, a photocatalyst layer that is transparent and has good adhesion can be obtained. 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 particle shape, a true sphere is most preferable, but a substantially circular or elliptical shape is also preferable. In this case, the particle length is approximately calculated as ((major axis + minor axis) / 2). Within this range, weather resistance, harmful gas decomposability, and various desired film properties (such as ultraviolet absorption, transparency, and film strength) are efficiently exhibited. In particular, a photocatalyst layer that is transparent and has good adhesion can be obtained.

  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 particle shape, a true sphere is most preferable, but a substantially circular or elliptical shape is also preferable. In this case, the particle length is approximately calculated as ((major axis + minor axis) / 2).

  The content of the inorganic oxide particles in the photocatalyst layer and the coating liquid of the present invention exceeds 70 parts by mass with respect to 100 parts by mass as the total amount of silica of the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone. 99 parts by mass or less, preferably more than 95 parts by mass and less than 99 parts by mass, and more preferably 95.5 parts by mass to 98 parts by mass.

  The photocatalyst layer and the coating liquid of the present invention contain copper element and silver element in order to exhibit high photocatalytic ability. In these, a metal and / or a metal compound composed of the metal can be added to the photocatalyst layer and the photocatalyst coating liquid. This addition can be performed by any of the method of mixing the metal or metal compound-containing solution or dispersion into the photocatalyst coating liquid, or the method of supporting the metal compound on the photocatalyst particles or the photocatalyst layer.

Copper element and silver element exist as metals and / or metal compounds. The ratio of the silver element to the copper element is preferably 0/100 <[Ag ₂ O / CuO] ≦ 60/40 in terms of mass ratio as Ag ₂ O / CuO in terms of Ag ₂ O and CuO, more preferably 10 / 90 or more and 60/40 or less, more preferably 10/90 or more and 55/45 or less. Also, elemental copper and silver elements, which total amount in terms of Ag 2 _O and CuO are added 0.5 to 5 wt% with respect to the photocatalyst particles. When the ratio of the silver element to the copper element is in such a range, compared to the photocatalyst layer to which each of the copper element and the silver element is added alone, it has antifungal properties under irradiation of light capable of exciting the photocatalyst such as ultraviolet rays. And a photocatalyst layer with extremely good alga-proof properties.

When an appropriate amount of ultraviolet rays is irradiated in a situation where a photocatalyst, a copper compound and a silver compound coexist, it is considered that the photocatalyst and the copper compound directly act on antifungal properties. It is considered that the silver compound is reduced by electrons generated by the photocatalyst and contributes to improvement of charge separation efficiency. The optimum value for the Ag ₂ O / CuO ratio in the photocatalyst layer is that if the ratio is too small, the specific effect due to the coexistence of the silver compound is also small. This is presumably because the relative concentration of the compound is reduced, the antifungal property is reduced, and further, the influence of coloring by silver cannot be ignored.

The photocatalyst layer of the present invention preferably contains substantially no dried hydrolyzable silicone, and more preferably does not contain at all. The hydrolyzable silicone is a general term for an organosiloxane having an alkoxy group and / or a partially hydrolyzed condensate thereof. However, it is permissible to contain hydrolyzable silicone as an optional component as long as elution of the organic antifungal agent of the present invention and harmful gas decomposability can be ensured. Therefore, the content of hydrolyzable silicone is 0 part by mass or more with respect to 100 parts by mass of the total amount of photocatalyst particles, inorganic oxide particles, and hydrolyzable silicone in terms of silica in terms of silica (SiO ₂ ). The amount is less than 10 parts by mass, preferably 5 parts by mass or less, and most preferably 0 part by mass. As the hydrolyzable silicone, a tetrafunctional silicone compound is often used. For example, ethyl silicate 40 (oligomer, R is an ethyl group), ethyl silicate 48 (oligomer, R is an ethyl group), methyl silicate 51 (oligomer, R is a methyl group) Group) (both manufactured by Colcoat Co.).

In the photocatalyst layer of the present invention, the mass ratio (a) / (b) of the content (a) of the photocatalyst particles and the combined value (b) of the hydrolyzable silicone content in terms of inorganic oxide particles and SiO ₂ is The range is preferably from 1/99 to less than 20/80, more preferably from 3/97 to less than 20/80, and still more preferably from 5/95 to less than 20/80. By setting it as such a range, the photocatalyst coating body excellent in photocatalyst performance and a weather resistance is obtained.

  The photocatalyst coating liquid of the present invention can be obtained by dispersing photocatalyst particles, inorganic oxide particles, copper element, silver element, and optionally hydrolyzable silicone and surfactant in the solvent at the above specific mixing ratio. it can. As the solvent, any solvent that can appropriately disperse the above-described constituent components can be used, and water and / or an organic solvent may be used. Moreover, the solid content concentration of the photocatalyst coating liquid of the present invention 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 is contained as an optional component in an amount of 0 parts by mass or more and less than 10 parts by mass with respect to 100 parts by mass as a total of 100 parts by mass 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 depending on the combination of the coating liquid and the substrate, and the lower limit in that case is 0.1 part by mass. May be. 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 according to the wettability required for the photocatalyst coating solution, 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.

Photocatalyst layer manufacturing method The photocatalyst coating body of this invention can be easily manufactured by apply | coating the photocatalyst coating liquid of this invention on the base material which has the said intermediate | middle layer. 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, screen printing, electrodeposition, vapor deposition and the like 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.

  Although the dry film thickness of a coating film is not specifically limited, Preferably it is 0.4 micrometer-5 micrometers, More preferably, they are 0.5 micrometer or more and 3 micrometers or less. When it is thinner than 0.4 μm, the photocatalytic performance, particularly harmful gas decomposability, is reduced. On the other hand, if it is thicker than 5 μm, the transparency may be lowered, and further, the effect of increasing the addition amount cannot be obtained, which is not economical.

The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples.
In the following examples, the intermediate layer coating solution was prepared by appropriately mixing one of the following silicone-modified acrylic resin materials, water, and a film-forming aid, and details are shown in Table 1. The film-forming aid concentration was 3% by mass with respect to the intermediate layer coating solution.
Silicone-modified acrylic resin dispersion having a silicon atom content of 10% by mass with respect to the solid content of the silicone-modified resin. Silicone modification having a silicon atom content of 0.2% by mass with respect to the solid content of the silicone-modified resin. Acrylic resin dispersion ・ Silicone-modified acrylic resin dispersion having a silicon atom content of 16.5% by mass based on the solid content of the silicone-modified resin.

  As the organic fungicide, a commercially available nitrogen-sulfur compound and a triazine compound were used, and the concentration of the fungicide was 0.5% by mass with respect to the intermediate layer coating solution.

In the following examples, the photocatalyst layer coating liquid was prepared by appropriately mixing the photocatalyst particles shown below, any inorganic oxide, water, and a surfactant. Details are shown in Table 2. The raw materials used are as follows.
Photocatalyst particles / titania water dispersion (average particle size: 42 nm, basic)
Ag / Cu-containing titania aqueous dispersion: photocatalytic titania aqueous dispersion in which a total amount of silver compound and copper compound converted to Ag ₂ O and CuO was added in an amount of 0 to 5% by mass with respect to titania (average particle diameter : 48 nm, basic)
Inorganic oxide particles / water-dispersed colloidal silica (average particle size: 14 nm, basic)
・ Water-dispersed colloidal silica (average particle size: 26 nm, basic)
Water-dispersed colloidal silica (average particle size: 5 nm, basic)
Water-dispersed colloidal silica (average particle size: 51 nm, basic)
Hydrolyzable silicone / tetramethoxysilane polycondensate (manufactured by Tama Chemical Co., Ltd., trade name: M silicate 51)
Surfactant / polyether modified silicone surfactant

Examples 1 to 8: Evaluation of gas decomposability (reference)
The photocatalyst coating body provided with the intermediate | middle layer containing an organic fungicide and a photocatalyst layer was manufactured as follows. First, a float plate glass was prepared as a base material. The intermediate layer coating solution described in M-1 in Table 1 was spray-coated on a glass substrate previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes to obtain an intermediate layer. The solid content concentration of the resin in this M-1 solution was about 20% by mass. When the film thickness of the intermediate layer was measured by observation with a scanning electron microscope, it was about 10 μm in any of Examples 1 to 8.

  On the other hand, a titania aqueous dispersion as a photocatalyst, a water-dispersed colloidal silica as an inorganic oxide, and water as a solvent are mixed at a blending ratio shown by T-1 to T-8 in Table 2 to form a photocatalytic coating. A liquid was obtained. The total solid content concentration of the photocatalyst, the inorganic oxide, and the hydrolyzable silicone in the photocatalyst coating liquid was 5.5% by mass. The obtained photocatalyst coating liquid was spray-coated on the intermediate layer coating body heated in advance to 50 ° C., and dried at 120 ° C. for 5 minutes. When the film thickness of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 0.5 μm in any of Examples 1 to 8. Thus, an intermediate layer and a photocatalyst layer were formed to obtain a photocatalyst-coated body.

The photocatalyst-coated body having a size of 50 × 100 mm thus obtained was subjected to a gas decomposability test as follows. As a pretreatment, the photocatalyst-coated body was irradiated with 1 mW / cm ² of BLB light for 12 hours or more. One coated body sample was set in the reaction vessel described in JIS R1701. NO gas was mixed with air adjusted to 25 ° C. and 50% RH so as to be about 1000 ppb, and introduced into a light-shielded reaction vessel for 20 minutes. Thereafter, BLB light adjusted to 3 mW / cm ² was irradiated for 20 minutes while the gas was introduced. Thereafter, the reaction vessel was shielded from light again with the gas introduced. The NOx removal amount was calculated according to the following formula from the NO and NO ₂ concentrations before and after the BLB light irradiation.
NOx removal amount = [NO (after irradiation) −NO (at irradiation)] − [NO ₂ (at irradiation) −NO ₂ (after irradiation)]

  The obtained results were as shown in Table 3. As shown in Table 3, when the photocatalyst layer was composed of photocatalyst particles and an inorganic oxide and did not contain hydrolyzable silicone, good NOx decomposability was exhibited. On the other hand, those containing 10 parts by mass of hydrolyzable silicone were found to lose NOx decomposability. Moreover, even if the photocatalyst ratio in the photocatalyst layer was increased 2.5 times, the tendency was not changed.

Examples 9 and 10: Evaluation of algae resistance (reference)
The photocatalyst coating body provided with the intermediate | middle layer and the photocatalyst layer was manufactured as follows. First, a float plate glass was prepared as a base material. An intermediate layer coating solution described in M-1 and M-2 in Table 1 was spray-coated on a glass substrate previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes to obtain an intermediate layer. The solid content concentration of the resin in the liquids M-1 and M-2 was about 20% by mass. When the film thickness of the intermediate layer was measured by observation with a scanning electron microscope, it was about 10 μm in any of Examples 9 and 10.

  On the other hand, a titania aqueous dispersion as a photocatalyst, a water-dispersed colloidal silica as an inorganic oxide, and water as a solvent were mixed at a mixing ratio shown by T-4 in Table 2 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 coating body heated in advance to 50 ° C., and dried at 120 ° C. for 5 minutes. When the film thickness of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 0.5 μm in any of Examples 9 and 10. Thus, an intermediate layer and a photocatalyst layer were formed to obtain a photocatalyst-coated body.

  The photocatalyst-coated body having a size of 50 × 50 mm obtained in this way was subjected to an algal control test as follows. Chlorella (NIES-642) was used as a substitute for algae. Inorganic salt medium was used as a nutrient source for chlorella during the test. A photocatalyst-coated body was placed in the petri dish, and water containing a certain amount of chlorella and an inorganic salt medium was placed. The lid was covered and cultured under a fluorescent lamp with an illuminance of 4000 lx under a temperature of 25 ° C. ± 2 ° C. A transparent acrylic plate was sandwiched between the petri dish and the fluorescent lamp to completely block ultraviolet rays. Chlorella reproduction was compared and judged visually.

  The obtained results were as shown in Table 4. Here, ○ in the table indicates that no algae were visually observed, and x indicates that algae was visually observed.

Examples 11 to 13: Evaluation of transparency of coating film (reference)
The photocatalyst coating body provided with the photocatalyst layer was manufactured as follows. First, a float plate glass was prepared as a base material. A titania aqueous dispersion as a photocatalyst, a water-dispersed colloidal silica as an inorganic oxide, and water as a solvent are mixed in a mixing ratio shown in T-4, T-9, and T-10 in Table 2, A photocatalytic coating solution was obtained. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass. After 1 g of the obtained photocatalyst coating liquid was dropped on a 50 × 50 mm plate glass, it was spin-coated at 1000 rpm for 10 seconds to obtain a coating film transparency test body.

  About the photocatalyst coating body of the magnitude | size of 50x50 mm obtained in this way, the haze value was measured in BYK-Gardner company make-gard plus.

  The results obtained were as shown in Table 5. From Table 5, it was found that the photocatalyst-coated bodies of Examples 11 and 12 were able to suppress the haze value to less than 1% and ensure transparency.

Examples 14 to 16: Evaluation of adhesion of coating film (reference)
The photocatalyst coating body provided with the intermediate | middle layer containing an organic fungicide and a photocatalyst layer was manufactured as follows. First, a general-purpose epoxy resin-based primer was applied to a float plate glass as a base material and dried. The intermediate layer coating solution described in M-1 in Table 1 was spray-coated on a glass substrate previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes to obtain an intermediate layer. The solid content concentration of the resin in the M-1 solution was about 20% by mass. When the film thickness of the intermediate layer was measured by observation with a scanning electron microscope, it was about 10 μm in any of Examples 14 to 16.

  On the other hand, a titania aqueous dispersion as a photocatalyst, a water-dispersed colloidal silica as an inorganic oxide, and water as a solvent are mixed in a mixing ratio shown in T-4, T-9, and T-11 in Table 2. Thus, a photocatalyst coating solution was obtained. 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 coating body heated in advance to 50 ° C., and dried at 120 ° C. for 5 minutes. When the film thickness of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 0.5 μm in any of Examples 14 to 16. Thus, an intermediate layer and a photocatalyst layer were formed to obtain a photocatalyst-coated body.

  The photocatalyst-coated body having a size of 50 × 50 mm obtained in this way was immersed in a saturated aqueous calcium hydroxide solution at room temperature for 18 hours. After washing with water and drying at 50 ° C. for 1 hour, a cellophane tape specified in JIS Z1522 is applied to the surface of the coating film, peeled off instantaneously in a vertical direction, the peeled surface is observed, and the film remains before and after It was confirmed.

  The obtained results were as shown in Table 6. Here, ○ in the table indicates that no photocatalyst layer peeling was observed, and Δ indicates that some photocatalyst layer peeling was observed. It turned out that the photocatalyst coating body of Examples 14 and 15 has sufficient adhesiveness with respect to an intermediate | middle layer.

Examples 17 to 23: Evaluation of weather resistance of coating film-1 (reference)
The photocatalyst coating body provided with the intermediate | middle layer containing an organic fungicide and a photocatalyst layer was manufactured as follows. First, a float plate glass was prepared as a base material. A glass substrate that had been heated to 50 ° C. in advance was spray-coated with the intermediate layer coating liquid described in M-3 of Table 1 mixed with a color pigment, and dried at 120 ° C. for 5 minutes to obtain an intermediate layer.
The solid content concentration of the resin in the liquid was about 20% by mass. When the film thickness of the intermediate layer was measured by observation with a scanning electron microscope, it was about 10 μm in any of Examples 17-23.

  On the other hand, titania aqueous dispersion as a photocatalyst, water-dispersed colloidal silica as an inorganic oxide, and water as a solvent are T-1 to T-4, T-6, T-12, and T-13 in Table 2. To obtain a photocatalyst coating liquid. 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 coating body heated in advance to 50 ° C., and dried at 120 ° C. for 5 minutes. When the film thickness of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 0.5 μm in any of Examples 17-23. Thus, an intermediate layer and a photocatalyst layer were formed to obtain a photocatalyst-coated body.

  About the photocatalyst coating body of a magnitude | size of 50x100 mm obtained in this way, the weather resistance test was done as follows. The photocatalyst-coated body was put into a sunshine weatherometer (S-300C, manufactured by Suga Test Instruments) defined in JIS B7753. After 300 hours, the test piece was taken out, the color difference was measured before and after the acceleration test with a color difference meter ZE2000 manufactured by Nippon Denshoku, and the degree of color change was evaluated by comparing the Δb values.

  The obtained results were as shown in Table 7. Here, G in the table indicates that the color has hardly changed, and NG indicates that the Δb value has shifted to the plus side (yellowing side). As shown in Table 7, by making the photocatalyst content in the photocatalyst layer less than 20 parts by mass, the photocatalyst layer has sufficient weather resistance even when the photocatalyst layer is applied to the intermediate layer having a small silicon atom content. I understood.

Examples 24 and 25: Evaluation of weather resistance of coating film-2 (reference)
The photocatalyst coating body provided with the intermediate | middle layer containing an organic fungicide and a photocatalyst layer was manufactured as follows. First, a general-purpose epoxy resin-based primer was applied to a galvanized steel sheet as a base material and dried. The intermediate layer coating liquid described in M-1 and M-4 of Table 1 was spray coated and dried at 120 ° C. for 5 minutes to obtain an intermediate layer. The solid content concentration of the resin in the M-1 and M-4 solutions was about 20% by mass. When the film thickness of the intermediate layer was measured by observation with a scanning electron microscope, it was about 10 μm in both Examples 24 and 25.

  On the other hand, a titania aqueous dispersion as a photocatalyst, a water-dispersed colloidal silica as an inorganic oxide, and water as a solvent were mixed at a mixing ratio shown by T-4 in Table 2 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 coating body heated in advance to 50 ° C., and dried at 120 ° C. for 5 minutes. When the film thickness of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 0.5 μm in both Examples 24 and 25. Thus, an intermediate layer and a photocatalyst layer were formed to obtain a photocatalyst-coated body.

  About the photocatalyst coating body of a magnitude | size of 50x100 mm obtained in this way, the weather resistance test was done as follows. The photocatalyst-coated body was put into a metering weatherometer (M6T manufactured by Suga Test Instruments). The appearance of the test piece was confirmed after 150 hours.

  In Example 24, in which an acrylic modified silicone resin having a silicon atom content of 10% by mass with respect to the solid content of the silicone modified resin was used for the intermediate layer, no cracks were observed, the appearance was good, and sufficient weather resistance. It was found to have On the other hand, in Example 25 using an acrylic-modified silicone resin having a silicon atom content of 16.5% by mass, generation of cracks was partially observed.

Example 26: Weather resistance evaluation of coating film-3 (reference)
A photocatalyst-coated body was prepared under the same conditions as in Example 24 except that the size of the substrate was 150 × 65 mm. About this photocatalyst coating body, the weather resistance test was done as follows. The photocatalyst-coated body was put into a sunshine weatherometer (S-300C, manufactured by Suga Test Instruments) defined in JIS B7753. After 4500 hours had elapsed, the test piece was taken out, the color difference was measured with a color difference meter ZE2000 manufactured by Nippon Denshoku, and the ΔE value was calculated. Further, the water contact angle was measured with a contact angle meter (CA-X150, manufactured by Kyowa Interface Science). The ΔE value was calculated based on the method described in JIS Z8730.

  The photocatalyst-coated body obtained in the present invention was found to have surprising weather resistance and super hydrophilicity, with a ΔE value of 0.5 and a water contact angle of 5 ° or less after 4500 hours of sunshine weatherometer. . Moreover, the NOx gas decomposition and the adhesion of the coating film were almost the same level as in the initial stage.

Example 27: Evaluation of weather resistance of coating film-4 (reference)
About the photocatalyst coating body produced on the same conditions as Example 26, the weather resistance test was done as follows. The photocatalyst-coated body was exposed outdoors in Chigasaki City, Kanagawa Prefecture, with a 45 ° slope from the horizontal to the top, facing south. After about 500 days, the test piece was taken out and the color difference was measured with a color difference meter ZE2000 manufactured by Nippon Denshoku.

  The photocatalyst-coated body obtained in the present invention was found to have an amazing antifouling property, with a ΔE value of about 0.5 or less after about 500 days after outdoor exposure.

Examples 28 to 33: Evaluation of antifungal property by silver compound and copper compound-1
The photocatalyst coating body provided with the intermediate | middle layer and the photocatalyst layer was manufactured as follows. First, a float plate glass was prepared as a base material. An intermediate layer coating solution described in M-2 of Table 1 was spray-coated on a glass substrate previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes to obtain an intermediate layer. The solid content concentration of the resin in the liquid M-2 was about 20% by mass. When the film thickness of the intermediate layer was measured by observation with a scanning electron microscope, it was about 10 μm in any of Examples 28 to 33.

  On the other hand, a titania aqueous dispersion as a photocatalyst, a water-dispersed colloidal silica as an inorganic oxide, and water as a solvent are mixed at a blending ratio shown in T-4 and T-14 to T-18 in Table 2. Thus, a photocatalyst coating solution was obtained. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass. In Examples 28 to 32, an Ag / Cu-containing titania aqueous dispersion in which the compounding ratio of the silver compound and the copper compound was adjusted was used (however, Example 31 was all a copper compound, and Example 32 was a silver compound). In No. 33, a titania aqueous dispersion containing no silver compound or copper compound was used.

The obtained photocatalyst coating liquid was spray-coated on the intermediate layer coating body heated in advance to 50 ° C., and dried at 120 ° C. for 5 minutes. When the film thickness of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 1 μm in any of Examples 28 to 33. Thus, an intermediate layer and a photocatalyst layer were formed to obtain a photocatalyst-coated body. After pre-treatment of these photocatalyst-coated bodies with 1 mW / cm ² of BLB light for 24 hours, the following antifungal test was performed.

The anti-fungal property of the photocatalyst-coated body having a size of 50 × 50 mm thus obtained was evaluated as follows. Aspergillus niger (NBRC6341) previously cultured at 25 ° C. for 7 to 14 days on a potato dextrose agar medium as a test bacterium, this was dispersed in physiological saline containing 0.005% by weight of dioctyl sodium sulfosuccinate, and a spore suspension It was created.

The spore suspension was dropped on the photocatalyst-coated body obtained by the above method so that the amount of the spore suspension was 4 to 6 × 10 ⁵ pieces / mL per one test piece to obtain an anti-mold test piece. In accordance with the film adhesion method described in JIS R1702 (2006), the test piece was covered with an adhesion film, placed in a petri dish capable of moisture retention, and moisturized glass was placed and used for the test.

The test piece was placed together with the petri dish under BLB light irradiation, and irradiated with BLB light for 24 hours so that the photocatalyst-coated body surface was 0.4 mW / cm ² .

  After 24 hours of irradiation, the spore suspension was collected and cultured on a potato dextrose agar medium, and the number of surviving bacteria was counted. The antifungal property was obtained by determining the difference between the logarithmic value of the survival cell count obtained in Examples 28 to 33 and the logarithmic value of the survival cell count of the photocatalyst-unprocessed specimen subjected to the same test. .

The test results are shown in Table 8. Here, the antifungal activity value in the table is the value of the difference between the logarithmic value of the survival cell count obtained in Examples 28 to 33 and the logarithmic value of the survival cell count of the photocatalyst untreated specimen, The larger the value, the higher the antifungal property. In the example produced using the Ag / Cu-containing titania aqueous dispersion, the antifungal activity value is higher than the example in which only the silver compound or only the copper compound is added. It was confirmed that high antifungal performance was obtained by mixing.

Examples 34 and 35: Evaluation of antifungal property by silver compound and copper compound-2
The photocatalyst coating body provided with the intermediate | middle layer and the photocatalyst layer was manufactured as follows. First, a float plate glass was prepared as a base material. An intermediate layer coating solution described in M-2 of Table 1 was spray-coated on a glass substrate previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes to obtain an intermediate layer. The solid content concentration of the resin in the liquid M-2 was about 20% by mass. When the film thickness of the intermediate layer was measured by observation with a scanning electron microscope, it was about 10 μm in both Example 34 and Example 35.

  On the other hand, an Ag / Cu-containing titania aqueous dispersion as a photocatalyst, water-dispersed colloidal silica as an inorganic oxide, and water as a solvent are mixed in a mixing ratio shown by T-19 and T-21 in Table 2. Thus, a photocatalyst coating solution was obtained. 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 formed into a film by the method similar to Examples 28-33, and the photocatalyst body of Example 34 and Example 35 was obtained. When the film thickness of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 1 μm in both Examples 34 and 35. About this photocatalyst body, antifungal evaluation was performed by the method similar to Examples 28-33.

The test results are shown in Table 9. The antifungal activity values of Example 29 are also shown in Table 9. It was confirmed that high antifungal performance was obtained when the amount of [Ag ₂ O + CuO] was 0.5% by mass, 3% by mass, and 5% by mass with respect to the titanium oxide particles.

Examples 36 and 37: Evaluation of antifungal property by silver compound and copper compound-3
The photocatalyst coating body provided with the intermediate | middle layer and the photocatalyst layer was manufactured as follows. First, a float plate glass was prepared as a base material. An intermediate layer coating solution described in M-1 and M-2 in Table 1 was spray-coated on a glass substrate previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes to obtain an intermediate layer. The solid content concentration of the resin in the liquid M-1 or M-2 was about 20% by mass. When the film thickness of the intermediate layer was measured by observation with a scanning electron microscope, it was about 10 μm in both Example 36 and Example 37.

  On the other hand, an Ag / Cu-containing titania aqueous dispersion as a photocatalyst, a water-dispersed colloidal silica as an inorganic oxide, and water as a solvent are mixed in a mixing ratio shown by T-20 in Table 2 to obtain a photocatalytic coating. A liquid was obtained. 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 formed into a film in the same manner as in Examples 28 to 33, and the photocatalyst of Example 36 was obtained. When the film thickness of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 1 μm in both Example 36 and Example 37. About this photocatalyst body, antifungal evaluation was performed by the method similar to Examples 28-33.

  The test results are shown in Table 10. In Example 37 in which the organic antifungal agent was included in the intermediate layer, the effect of the antifungal agent was synergized, and the antifungal activity value was further increased.

Claims (12)

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 intermediate layer comprises an organic antifungal agent;
The photocatalytic layer is
1 to 20 parts by mass of photocatalyst particles,
70 to 99 parts by mass of inorganic oxide particles,
A hydrolyzable silicone dry matter having a weight of 0 to less than 10 parts by weight in terms of silica, and the total amount of silica equivalents of the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone is 100 parts by weight. Including
In addition, containing copper element and silver element,
A photocatalyst-coated body in which gaps between particles exist in the photocatalyst layer.   The average particle diameter of the inorganic oxide is calculated by measuring the length of any 100 particles that enter a 200,000-fold field of view with a scanning electron microscope. The number average particle diameter of more than 5 nm and less than 40 nm The photocatalyst coating body of Claim 1 which has these.   The photocatalyst-coated body according to claim 1 or 2, wherein the photocatalyst particles are titanium oxide.   The photocatalyst coating body as described in any one of Claims 1-3 whose said inorganic oxide particle is a silica.   The photocatalyst coating body as described in any one of Claims 1-4 in which the said intermediate | middle layer comprises a silicone modified resin.   The photocatalyst coating body as described in any one of Claims 1-5 used as an exterior material. It is a photocatalyst coating liquid used for manufacture of the photocatalyst coating body as described in any one of Claims 1-6,
A solvent,
1 to 20 parts by mass of photocatalyst particles,
70 parts by mass or more and 99 parts by mass or less of inorganic oxide particles and 0 to 10 parts by mass of hydrolyzable silicone in terms of silica,
A photocatalyst coating liquid comprising a total amount of the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone in an amount equivalent to silica of 100 parts by mass, and further containing a copper element and a silver element.   The average particle diameter of the inorganic oxide is calculated by measuring the length of any 100 particles that enter a 200,000-fold field of view with a scanning electron microscope. The number average particle diameter of more than 5 nm and less than 40 nm The photocatalyst coating liquid according to claim 7, comprising:   The photocatalyst coating liquid according to claim 7 or 8, wherein the photocatalyst particles are titanium oxide particles.   The photocatalyst coating liquid as described in any one of Claims 7-9 whose said inorganic oxide particle is a silica particle.   It is a coating liquid for forming the intermediate | middle layer used for manufacture of the photocatalyst coating body as described in any one of Claims 1-6, Comprising: A solvent, silicone modified resin, and an organic antifungal agent are included. A coating solution consisting of   It is a combination of the coating liquid used for manufacture of the photocatalyst coating body as described in any one of Claims 1-6, Comprising: The photocatalyst coating liquid as described in any one of Claims 7-10, The combination with the coating liquid for forming the intermediate | middle layer of 11.