JP2011056418A - Exterior structure, and coating solution therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exterior structure which is constituted so as to suppress the deterioration of a base material and also excellent in harmful gas decomposition properties and fungicidal-algicidal properties, and a coating solution therefor. <P>SOLUTION: The exterior structure is formed by providing a photocatalyst layer on the surface of the base material and the photocatalyst layer is obtained by drying the photocatalyst coating solution applied to the surface of the base material. The photocatalyst coating solution is composed of photocatalytic metal oxide particles, silica particles, a curable silicone emulsion, a water soluble copper compound and water. The silica particles are partially subjected to coating or modification treatment by a substance having a hydrophobic group and the photocatalytic metal oxide particles have oxidation power stronger than reduction power. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to an outer structure having a photocatalytic function such as decomposability of harmful gas and self-cleaning property by rain / washing.
Alternatively, the present invention relates to a coating liquid for exteriors capable of providing a photocatalytic function such as harmful gas decomposability, self-cleaning property by rain / water washing, etc., by forming a coating layer on a building, a vehicle, members constituting them, and a composite material. .

In recent years, photocatalysts such as titanium oxide have been used in many applications such as buildings of buildings, vehicles, members constituting them, and composite materials.
For outdoor use, by applying a photocatalyst to the surface of the base material, it is possible to impart a function of decomposing harmful substances such as NOx and SOx using light energy. Further, if the surface of the layer is made at least hydrophilic when irradiated with light, it is possible to provide a self-cleaning function in which attached dirt is washed away by rain.
In addition, for indoor use, it is possible to impart a function of decomposing toxic substances such as VOCs and an antibacterial function using light energy.

In the case of building structures, vehicles, and members, composite materials, etc., the surface of the base material to which the photocatalytic function is to be applied is enameled or applied on top of the enamel to provide design. Often painted clear.
If an attempt is made to directly form a photocatalyst layer there, the enameled and clear painted surfaces are mainly composed of organic matter, and in the long term, the painted surface will deteriorate due to the photocatalyst particles present at the interface between the photocatalyst layer and the painted surface. Cause problems.

Therefore, conventionally, a barrier layer containing a large amount of inorganic components has been formed between the enamel-coated surface, the clear-coated surface, and the photocatalyst layer (Japanese Patent Laid-Open No. 2007-167718).
However, when the barrier layer is formed, not only the cost is increased, but also man-hours are required and the photocatalytic function cannot be easily provided.

  Therefore, the photocatalytic function is exhibited while suppressing the deterioration of the enameled surface or the clear painted surface, more preferably, there is no off-flavor or environmental pollution during application, and most preferably the deterioration of the substrate surface due to ultraviolet rays is suppressed. A photocatalyst-coated body or a photocatalyst coating solution that directly coats the material to form a photocatalytic functional layer is required.

As such a photocatalyst coating composition that directly exerts a photocatalytic function on one substrate, the content of silane-modified photocatalyst particles and alkoxy groups and / or hydroxyl groups bonded to silicon atoms is 7 to 20 mmol. An aqueous organic / inorganic composite composition comprising colloidal silica of / g and polymer emulsion particles having an alkoxy group bonded to a silicon atom and / or a hydroxyl group content of 1 to 20 mmol / g is known. (Japanese Unexamined Patent Application Publication No. 2008-222887).
Further, JP-A-2008-31297 states that “the above-mentioned photocatalyst (a1) is preferably added with a metal such as Pt, Rh, Ru, Nb, Cu, Sn, Ni, Fe and / or an oxide thereof. It can also be used after being fixed or coated with silica, porous calcium phosphate or the like (see, for example, JP-A-10-244166).

JP 2007-167718 A JP 2008-2222887 A Patent 3985164 JP 2004-51644 A JP 2008-31297

However, in Japanese Patent Application Laid-Open No. 2008-222887, a high photocatalytic decomposition activity cannot be obtained when a thick film exceeding 2 μm is applied so as to suppress the deterioration of the enamel coating surface or the clear coating surface.
In addition, when Cu and / or oxides thereof are added to a photocatalyst as disclosed in Japanese Patent Application Laid-Open No. 2008-31297, copper is reduced by the photocatalytic action, and an antifungal / algae-proof effect is expected. , The effect becomes weaker.
Therefore, in the present invention, in view of the above circumstances, even when coating with a thick film exceeding 2 μm so as to suppress the deterioration of the enamel painted surface or the clear painted surface, the photocatalyst has a high antifungal and algal control effect. An object of the present invention is to provide an exterior and an exterior coating liquid capable of obtaining gas decomposition activity.

  That is, the outer surface of the substrate is provided with a photocatalyst layer, and the photocatalyst layer is obtained by applying a photocatalyst coating liquid and then drying, and the photocatalyst coating liquid comprises photocatalytic metal oxide particles and silica. The silica particle comprises a particle, a curable silicone emulsion, a water-soluble copper compound, and water, and the silica particle is partially coated or modified with a substance having a hydrophobic group. .

  The exterior coating liquid according to the present invention includes photocatalytic metal oxide particles, silica particles, a curable silicone emulsion, a water-soluble copper compound, and water, and the silica particles are hydrophobic groups. A coating liquid for exteriors, which is partially coated or modified with a substance having

Exterior are by Exterior present invention, there is provided a Exterior having a photocatalyst layer on a substrate surface, wherein the photocatalyst layer is obtained by drying after coating the photocatalyst coating liquid, the photocatalyst coating liquid, photocatalytic Metal oxide particles, silica particles, a curable silicone emulsion, a water-soluble copper compound, and water, wherein the silica particles are partially coated or modified with a substance having a hydrophobic group. It is a featured site.
By adopting such a configuration, it is possible to provide an outer structure and a photocatalyst coating liquid that are excellent in harmful gas decomposability and mold / algae resistance while suppressing deterioration of the substrate.
The reason is considered as follows.
When photocatalytic coating liquid is applied to a substrate and dried, the photocatalytic metal oxide particles and silica particles have an affinity for water, so that when water diffuses and evaporates on the surface, it easily moves to the surface. . On the other hand, since photocatalytic metal oxide particles and silica particles have an affinity for water, the particles are likely to aggregate with each other, and in particular, silica particles having an excellent affinity for water are prominent.
In the present invention, silica particles are partially coated or modified in advance with a substance having a hydrophobic group. By doing so, aggregation of silica particles can be effectively suppressed.
By using the above silica particles, it is possible to effectively avoid a state where the silica particles block the gap between the silicone emulsions and prevent the photocatalytic metal oxide particles from moving upward. You can concentrate on concentration.
In addition, when the photocatalyst coating liquid is applied to the substrate and then dried, the water is dissolved in water as the water evaporates, along with the photocatalytic metal oxide particles having a small surface energy, and diffusion to the surface of the water. Copper compounds also move to the surface. As a result, the photocatalytic metal oxide particles and the copper compound are present at a high concentration while being separated from each other on the surface of the coated body when the drying is completed. Here, in the present invention, since the photocatalytic metal oxide particles are photocatalyst particles having an oxidizing power stronger than the reducing power, the copper compound is present at a suitable distance, so that the photoreducing action of copper hardly occurs. In addition, the photocatalytic metal oxide particles and copper can enhance the photocatalytic oxidizing power through the interaction with copper, and are also excellent in harmful gas decomposability and mold / algae resistance.
In the coated body, since the photocatalytic metal oxide particles are present at a high concentration on the surface side, not on the substrate side, the UV absorption of the photocatalyst particles is suppressed while suppressing the reaction at the interface between the photocatalyst and the substrate. This makes it possible to suppress the deterioration of ultraviolet rays.

According to a preferred embodiment of the present invention, the substance having a hydrophobic group is a silane having a hydrophobic group and / or a silicone having a hydrophobic group.
By doing so, it becomes easy to control the form of coating and modification on the silica surface.

According to the preferable form of this invention, the said silica particle makes the total amount of the hydroxyl group couple | bonded with the silicon atom, and the alkoxy group smaller than the amount in an untreated silica (6.3 mmol / g). More preferably, it should be less than 6 mmol / g.
By doing so, the aggregation of silica particles can be effectively suppressed, so that the photocatalytic metal oxide particles easily move upward, and even in a film having a long upward movement process, such as a thick film exceeding 2 μm, it is highly advanced. It becomes easier to provide an external structure capable of obtaining photocatalytic decomposition activity.

According to a preferred embodiment of the present invention, the curable silicone emulsion has a cured product with a total mass of the cured product (solid content mass) of the curable silicone emulsion, the photocatalytic metal oxide particles, and the silica particles. On the other hand, it is made 85 mass% or more, preferably 90 mass% or more.
By making it 85% by mass or more, a high photocatalytic decomposition activity can be obtained even in a film having a long upward movement process, such as a thick film exceeding 2 μm, and a transparent photocatalytic layer when no colorant is added. Can be formed.
Furthermore, by setting it to 90% by mass or more, a high photocatalytic decomposition activity can be obtained even in a film having a long upward movement process, such as a thick film exceeding 5 μm, and transparent when no colorant is added. A photocatalytic layer can be formed.

According to a preferred embodiment of the present invention, the film thickness of the photocatalyst layer is more than 2 μm and less than 20 μm, preferably more than 5 μm and less than 20 μm.
By doing so, the influence of the ultraviolet-ray to a base material can be lowered | hung and degradation of the base material by an ultraviolet-ray can be suppressed effectively.

According to a preferred embodiment of the present invention, the average particle size of the curable silicone emulsion is larger than the average particle size of the photocatalytic metal oxide particles and the silica particles.
By doing so, the upward movement of the photocatalytic metal oxide particles and silica particles becomes remarkable.
Accordingly, the silica particles can easily move upward without being bound by the silicone emulsion, and even in a film having a long upward movement process such as a thick film exceeding 2 μm, it is possible to obtain a high photocatalytic degradation activity. Is easier to provide.

According to a preferred embodiment of the present invention, the photocatalyst layer is transparent.
By doing so, when the base material is enamel coating or clear coating, high photocatalytic degradation activity can be obtained even in a film with a long upward movement process, such as a thick film exceeding 2 μm, while making effective use of its design. It is easier to provide a possible external structure.

  Here, as the degree of “transparency”, it is more preferable to secure the linear transmittance of the photocatalyst layer at a wavelength of 550 nm of 70% or more, more preferably 80% 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.

  According to a preferred embodiment of the present invention, the photocatalytic metal oxide particles include anatase type titanium oxide, rutile type titanium oxide, brookite type titanium oxide, tin oxide, zinc oxide, strontium titanate, tungsten oxide and cerium oxide. Particles of various metal oxides, particles obtained by combining a plurality of these particles, particles obtained by combining or doping these particles with a metal such as copper, platinum, iron, palladium, silver, and gold, and the surface of these particles. Particles partially coated and modified with silane, silicone, or hydrolyzable metal salt can be suitably used.

  According to a preferred embodiment of the present invention, the photocatalytic metal oxide 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.

  According to a preferred embodiment of the present invention, the photocatalyst particles preferably have an average crystallite diameter of 3 nm or more and less than 30 nm, more preferably 5 nm or more and 20 nm or less. The average particle diameter is calculated by the Scherrer equation from the integral width of the three strong lines of the X-ray profile obtained by the powder X-ray diffraction method.

  According to a preferred embodiment of the present invention, the content of the photocatalyst particles is a dry mass (solid content mass) of 0. 0 to the total mass of the curable silicone emulsion, the photocatalytic metal oxide particles, and the silica particles. It is more than 1% by mass and less than 15% by mass, more preferably more than 0.5% 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.

  As the water-soluble copper compound of the present invention, preferred examples of the copper (II) compound include gluconate, sulfate, malate, lactate, chloride, sulfate, nitrate, formate, acetate, Chelates can be suitably used.

  According to a preferred embodiment of the present invention, the silica particles preferably have an average particle size of more than 10 nm and 200 nm or less, more preferably more than 20 nm and 100 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).

  According to a preferred embodiment of the present invention, the degree of hydrophobicity of the silica particles is such that the total amount of hydroxyl groups and alkoxy groups bonded to silicon atoms in the silica particles is smaller than that in the untreated state (6.3 mmol / g). Preferably it is less than 6 mmol / g.

As a substance having a hydrophobic group that partially coats or modifies silica particles, for example, 1-3 functional silanes, silicones, and the like can be suitably used.
The amount of the substance used for coating or modifying treatment in the silica particles made of the substance having a hydrophobic group is preferably from 0.1 to 20% by mass, more preferably from 1 to 10% by mass, based on the amount of silica.

    Examples of the silane having a hydrophobic group used in the present invention include methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrisilane. Methoxysilane, isopropyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane, Vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltrie Xysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane, 3-aminopropyltrimethoxy Silane, 3-aminopropyltriethoxysilane, 2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanate pro Rutriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl Triethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3- (meth) acryloyloxypropyltri-n-propoxysilane, 3- (meth) acryloyloxy Trialkoxysilanes such as propyltriisopropoxysilane, 3-ureidopropyltrimethoxysilane, and 3-ureidopropyltriethoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, and diethyl Rudiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, diisopropyldimethoxysilane, diisopropyldiethoxysilane, di-n-butyldimethoxysilane, di-n-butyldiethoxysilane, di-n -Pentyldimethoxysilane, di-n-pentyldiethoxysilane, di-n-hexyldimethoxysilane, di-n-hexyldiethoxysilane, di-n-heptyldimethoxysilane, di-n-heptyldiethoxysilane, di- n-octyldimethoxysilane, di-n-octyldiethoxysilane, di-n-cyclohexyldimethoxysilane, di-n-cyclohexyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, 3- (meth) acryloyloxypropylmethyl Dialkoxysilane such as dimethoxysilane; trimethylmethoxysilane, monoalkoxysilane such as trimethyl silane, and the like. Moreover, these can be used individually or in mixture of 2 or more types.

  As the silicone having a hydrophobic group used in the present invention, a (partial) hydrolysis / condensation product of the above silane can be suitably used.

The curable silicone emulsion refers to a silicone emulsion that, when applied to a substrate and dried, causes a curing polymerization reaction due to a functional group present in the silicone emulsion, thereby forming a cured film.
Here, a hydrolysis / condensation reaction, a photopolymerization reaction, or the like can be suitably used for the curing reaction.
When the curing reaction is a hydrolysis / condensation reaction, a curable silicone emulsion having an alkoxide group as a functional group and generating a siloxane bond by the hydrolysis / condensation reaction can be suitably used.

In the curable silicone emulsion, in addition to the functional group that causes the curing reaction, an organic cross-linked portion by emulsion polymerization is present.
As the organic crosslinking part, a crosslinking part produced by radical polymerization such as an ethylene crosslinking part in which a vinyl group and a vinyl group are polymerized can be suitably used. Any cross-linked portion generated by radical polymerization is not particularly limited to a hydrocarbon group, and a combination of various modifying groups can be suitably used.

  In the curable silicone emulsion, an organic group bonded to a silicon atom may be present in addition to the functional group causing the curing reaction and the organic cross-linking portion. Here, examples of the organic group include hydrocarbon groups such as an alkyl group, a phenyl group, and a cycloalkyl group, and organic groups in which a part of the hydrogen is substituted with a modifying group. Here, as the modifying group, an amino group, a carboxyl group, a mercapto group, an acrylic group, an epoxy group, or the like can be suitably used.

  Next, the surfactant used as an emulsifier for the emulsion will be described. As the surfactant, conventionally known nonionic, cationic, and anionic surfactants and reactive emulsifiers containing functional groups capable of radical polymerization can be applied. Furthermore, nonionic surfactants such as polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene carboxylic acid ester, sorbitan ester, polyoxyethylene sorbitan ester, and cations such as alkyltrimethylammonium chloride and alkylbenzylammonium chloride Surfactants, alkyl or alkyl allyl sulfates, anionic surfactants such as alkyl or alkyl allyl sulfonates, dialkyl sulphosuccinates, zwitterionic surfactants such as amino acid types and betaine types, Radically polymerizable (meth) acrylate containing a group such as sulfonate, polyoxyethylene chain, quaternary ammonium salt in the molecule described in JP-A-8-27347, Styrene, can exhibit various reactive surfactants containing derivatives such as maleic acid ester compound.

  These surfactants may be used alone or in combination of two or more. The surfactant is preferably used in an amount of 0.5 to 15% by weight, particularly 1 to 10% by weight, based on the resin solid content in the emulsion.

  In the present invention, the photocatalyst layer may contain inorganic oxide particles other than silica particles. 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 alumina, zirconia, ceria, yttria, tin oxide, iron oxide, manganese oxide, nickel oxide, cobalt oxide, hafnia and other single oxide particles; and barium titanate, Examples thereof include composite oxide particles such as calcium silicate, aluminum borate, and potassium titanate.

  You may mix | blend a ultraviolet absorber in a photocatalyst layer. The content of the ultraviolet absorber is not limited as long as the weather resistance can be improved without inhibiting the expression of the photocatalytic activity. For example, 0.001 to 10% by mass, preferably 0.01 to 10% by weight in the photocatalyst layer. It is preferable to contain 5 mass%.

  Preferred examples of the ultraviolet absorber that can be used in the present invention include benzophenone-based, benzotriazole-based, and triazine-based ultraviolet absorbers.

  In particular, a triazine ultraviolet absorber is preferable because it is chemically stable. Specifically, hydroxyphenyltriazine or a derivative thereof can be suitably used as the triazine-based ultraviolet absorber.

  Specific examples of the benzophenone-based ultraviolet absorber include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid, and 2-hydroxy-4. -N-octoxybenzophenone, 2-hydroxy-4-n-dodecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, bis (5-benzoyl-4-hydroxy-2-methoxyphenyl) methane, 2,2 ' -Dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'dimethoxybenzophenone, 2,2 ', 4,4'-tetrahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy- 4-methoxy-2'- Ruboxybenzophenone, 2-hydroxy-4-stearyloxybenzophenone, octabenzone, and 2-hydroxy-4-acryloxybenzophenone, 2-hydroxy-4-methacryloxybenzophenone, 2-hydroxy-5-acryloxybenzophenone, 2-hydroxy -5-methacryloxybenzophenone, 2-hydroxy-4- (acryloxy-ethoxy) benzophenone, 2-hydroxy-4- (methacryloxy-ethoxy) benzophenone, 2-hydroxy-4- (methacryloxy-diethoxy) benzophenone, 2-hydroxy- Examples thereof include polymerizable benzophenone-based ultraviolet absorbers such as 4- (acryloxy-triethoxy) benzophenone and (co) polymers thereof.

  Specific examples of the benzotriazole-based UV absorber include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole and 2- (2′-hydroxy-5′-tert-butylphenyl) benzo. Triazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) benzotriazole, 2- (2-hydroxy-5-tert-octylphenyl) benzotriazole, 2- (2-hydroxy- 3,5-di-tert-octylphenyl) benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (α, α′-dimethylbenzyl) phenyl] benzotriazole), methyl-3- [3 -Tert-butyl-5- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] propionate Condensate with polyethylene glycol (molecular weight 300) (product name: TINUVIN-1130 manufactured by Ciba Geigy Co., Ltd.), isooctyl-3- [3- (2H-benzotriazol-2-yl) -5-tert-butyl- 4-hydroxyphenyl] propionate (manufactured by Ciba Geigy Japan, product name: TINUVIN-384), 2- (3-dodecyl-5-methyl-2-hydroxyphenyl) benzotriazole (manufactured by Ciba Geigy Japan, product name) : TINUVIN-571), 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-) tert-amylphenyl) benzotriazole, 2- (2′-hydroxy-4′-octoxyphe) ) Benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methylphenyl] benzotriazole, 2,2-methylenebis [4 -(1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (2H-benzotriazol-2-yl) -4,6-bis (1 -Methyl-1-phenylethyl) phenol (manufactured by Ciba Geigy Japan, product name: TINUVIN-900), and 2- (2′-hydroxy-5′-methacryloxyethylphenyl) -2H-benzotriazole (Otsuka Chemical) Product name: RUVA-93), 2- (2′-hydroxy-5′-methacryloxyethyl-3-tert-butylphenyl) -2H Benzotriazole, 2- (2′-hydroxy-5′-methacrylyloxypropyl-3-tert-butylphenyl) -5-chloro-2H-benzotriazole, 3-methacryloyl-2-hydroxypropyl-3- [3 ′ Polymerizable benzotriazole ultraviolet absorbers such as-(2 "-benzotriazolyl) -4-hydroxy-5-tert-butyl] phenylpropionate (manufactured by Ciba-Geigy Japan, product name: CGL-104) And TINUVIN-384-2 (product name, manufactured by Ciba-Geigy Corporation of Japan), TINUVIN-99-2 (product name, manufactured by Ciba-Geigy Corporation of Japan), TINUVIN-109 (product) Name, manufactured by Nippon Ciba-Geigy Corp.), TINUVIN-328 (product name, manufactured by Ciba-Geigy Corp. Japan), INUVIN-928 (product name, manufactured by Nihon Ciba-Geigy Corporation), and the like.

  Further, in the photocatalyst layer of the present invention, those further containing a hindered amine-based and / or hindered phenol-based light stabilizer, the photocatalyst layer of the present invention has excellent weather resistance due to a synergistic effect with the ultraviolet absorber. In view of light resistance, it is preferable.

  In particular, according to a preferred embodiment of the present invention, a hydroxyphenyl triazine compound may be blended as an ultraviolet absorber and a hindered amine compound as a light stabilizer. By doing so, the absorption performance of ultraviolet rays having a short wavelength of less than 380 nm by the photocatalyst layer is stabilized.

The content of the light stabilizer in the photocatalyst layer of the present invention is not limited as long as the weather resistance can be improved without inhibiting the expression of photocatalytic activity, but for example 0.001 to 10% by mass in the photocatalyst layer, It is preferable to contain 0.01-5 mass% preferably.
Specific examples of the hindered amine light stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, bis (2,2,6,6-tetramethylpiperidyl) sebacate, bis (1, 2,2,6,6-pentamethyl-4-piperidyl) 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-butylmalonate, 1- [2- [3- (3 5-Di-tert-butyl-4-hydroxyphenyl) propynyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propynyloxy] -2,2,6 6-tetramethylpiperidine, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl-1,2,2,6,6-pentamethyl-4-piperidyl-sebake Mixture (manufactured by Ciba Geigy Japan, product name: TINUVIN-292), bis (1-octoxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, TINUVIN-123 (product name, Japan) Ciba-Geigy Co., Ltd.), TINUVIN-111FDL (product name, manufactured by Nippon Ciba-Geigy Co., Ltd.), TINUVIN 292 (product name, manufactured by Ciba-Geigy Japan), and 1,2,2,6,6-pentamethyl-4- Piperidyl methacrylate, 1,2,2,6,6-pentamethyl-4-piperidyl acrylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl Acrylate, 1,2,2,6,6-pentamethyl-4-iminopiperidyl methacrylate, 2,2,6 6, -tetramethyl-4-iminopiperidyl methacrylate, 4-cyano-2,2,6,6-tetramethyl-4-piperidyl methacrylate, 4-cyano-1,2,2,6,6-pentamethyl-4- Examples thereof include polymerizable hindered amine ultraviolet absorbers such as piperidyl methacrylate and (co) polymers thereof.

  Specific examples of the hindered phenol light stabilizer include bis (3,5-tert-butyl) -4-hydroxytoluene, TINUVIN-144 (product name, manufactured by Ciba Geigy Japan, Inc.), and the like. it can.

As an optional component, the photocatalyst coating liquid may contain a surfactant in the coating liquid in addition to the emulsion emulsifier.
In a preferred embodiment of the present invention, the surfactant is preferably added in an amount of less than 10 parts by weight, more preferably about 0.1 to 2 parts by weight with respect to 1 part by weight of the photocatalyst particles.

  Examples of surfactants that can be added to the photocatalyst coating liquid according to the present invention include sulfonic acid polyoxyethylene alkylphenyl ether ammonium salt, sulfonic acid polyoxyethylene alkylphenyl ether sodium salt, fatty acid sodium soap, fatty acid potassium soap, dioctyl sulfosuccinate. Sodium acid, alkyl sulfate, alkyl ether sulfate, alkyl sulfate soda salt, alkyl ether sulfate soda salt, polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl ether sulfate soda salt, alkyl sulfate TEA salt, polyoxyethylene alkyl ether sulfate TEA salt 2-ethylhexyl alkyl sulfate sodium salt, acylmethyl taurate sodium , Sodium lauroylmethyl taurate, sodium dodecylbenzene sulfonate, disodium lauryl sulfosuccinate, disodium lauryl polyoxyethylene sulfosuccinate, polycarboxylic acid, oleoyl sarcosine, amide ether sulfate, lauroyl sarcosinate, sulfo FA ester Anionic surfactant such as sodium salt; polyoxyethylene lauryl ether, polyoxyethylene tridecyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene alkyl ether, polyoxyethylene Alkyl ester, polyoxyethylene alkylphenol ether, polyoxyethylene nonylphenyl ether, polyoxyethylene Xylethylene octyl phenyl ether, polyoxyethylene laurate, polyoxyethylene stearate, polyoxyethylene alkyl phenyl ether, polyoxyethylene oleate, sorbitan alkyl ester, polyoxyethylene sorbitan alkyl ester, polyether modified silicone, polyester modified silicone Sorbitan laurate, sorbitan stearate, sorbitan palmitate, sorbitan oleate, sorbitan sesquioleate, polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan oleate, Glycerol stearate, polyglycerin fatty acid ester, alkylalkylol Lauric acid diethanolamide, oleic acid diethanolamide, oxyethylene dodecylamine, polyoxyethylene dodecylamine, polyoxyethylene alkylamine, polyoxyethylene octadecylamine, polyoxyethylene alkylpropylenediamine, polyoxyethyleneoxypropylene block polymer, Nonionic surfactants such as polyoxyethylene stearate; amphoteric surfactants such as dimethylalkylbetaine, alkylglycine, amidebetaine, imidazoline, octadecyldimethylbenzylammonium chloride, alkyldimethylbenzylammonium chloride, tetradecylmethylbenzylammonium chloride, Dioleyldimethylammonium chloride, 1-hydroxyethyl-2- Rukiruimidazoline quaternary salt, alkylisoquinolinium bromide, polymeric amine, octadecyltrimethylammonium chloride, alkyltrimethylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, behenyltrimethylammonium chloride, alkylimidazoline quaternary salt, dialkyl And cationic surfactants such as dimethylammonium chloride, octadecylamine acetate, tetradecylamine acetate, alkylpropylenediamine acetate, and didecyldimethylammonium chloride.

  An organic antifungal agent may be blended in the photocatalyst 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, and 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.

Exterior coating liquid The exterior coating liquid according to the present invention comprises photocatalytic metal oxide particles, silica particles, a curable silicone emulsion, a water-soluble copper compound, and water, and the silica particles are hydrophobic. An exterior coating solution characterized in that it is partially coated or modified with a group-containing substance.
By adopting such a configuration, it is possible to provide an exterior and an exterior coating liquid that are excellent in harmful gas decomposability and antifungal / algae resistance while suppressing deterioration of the substrate.
The reason is considered as follows.
When the exterior coating solution is applied to the substrate and dried, the photocatalytic metal oxide particles and silica particles move to the surface when water diffuses and evaporates on the surface because of its affinity with water. It's easy to do. On the other hand, since photocatalytic metal oxide particles and silica particles have an affinity for water, the particles are likely to aggregate with each other, and in particular, silica particles having an excellent affinity for water are prominent.
In the present invention, silica particles are partially coated or modified in advance with a substance having a hydrophobic group. By doing so, aggregation of silica particles can be effectively suppressed.
By using the above silica particles, it is possible to effectively avoid a state where the silica particles block the gap between the silicone emulsions and prevent the photocatalytic metal oxide particles from moving upward. You can concentrate on concentration.
In addition, when the exterior coating liquid is applied to the substrate and then dried, it dissolves in water as the water evaporates, along with the photocatalytic metal oxide particles having a small surface energy, and diffusion to the surface of the water. The water-soluble copper compound is also moved to the surface. As a result, the photocatalytic metal oxide particles and the copper compound are present at a high concentration while being separated from each other on the surface of the coated body when the drying is completed. Here, in the present invention, since the photocatalytic metal oxide particles are photocatalyst particles having an oxidizing power stronger than the reducing power, the copper compound is present at a suitable distance, so that the photoreducing action of copper hardly occurs. In addition, the photocatalytic metal oxide particles and copper can enhance the photocatalytic oxidizing power through the interaction with copper, and are also excellent in harmful gas decomposability and mold / algae resistance.
In the coated body, since the photocatalytic metal oxide particles are present at a high concentration on the surface side, not on the substrate side, the UV absorption of the photocatalyst particles is suppressed while suppressing the reaction at the interface between the photocatalyst and the substrate. This makes it possible to suppress the deterioration of ultraviolet rays.

According to a preferred embodiment of the present invention, the substance having a hydrophobic group is a silane having a hydrophobic group and / or a silicone having a hydrophobic group.
By doing so, it becomes easy to control the form of coating and modification on the silica surface.

According to the preferable form of this invention, the said silica particle makes the total amount of the hydroxyl group couple | bonded with the silicon atom and the alkoxy group smaller than 6.3 mmol / g which is an unprocessed state. Preferably it is less than 6 mmol / g.
This makes it easy to effectively suppress the aggregation of silica particles and provides a structure capable of obtaining a high degree of photocatalytic decomposition activity even in a film having a long upward movement process, such as a thick film exceeding 2 μm. It will be easier to do.

According to a preferred embodiment of the present invention, the curable silicone emulsion has a cured product with a total mass of the cured product (solid content mass) of the curable silicone emulsion, the photocatalytic metal oxide particles, and the silica particles. On the other hand, it is made 85 mass% or more, preferably 90 mass% or more.
By making it 85% by mass or more, a high photocatalytic decomposition activity can be obtained even in a film having a long upward movement process, such as a thick film exceeding 2 μm, and a transparent photocatalytic layer when no colorant is added. Can be formed.
Furthermore, by setting it to 90% by mass or more, a high photocatalytic decomposition activity can be obtained even in a film having a long upward movement process, such as a thick film exceeding 5 μm, and transparent when no colorant is added. A photocatalytic layer can be formed.

According to a preferred embodiment of the present invention, the average particle size of the curable silicone emulsion is larger than the average particle size of the photocatalytic metal oxide particles and the silica particles.
By doing so, the upward movement of the photocatalytic metal oxide particles becomes remarkable.
Therefore, the photocatalytic coating can obtain a high photocatalytic decomposition activity even in a film having a long upward movement process, such as a thick film exceeding 2 μm, since the silica particles are easily moved upward without being bound by the silicone emulsion. It becomes easier to provide the composition.

In addition to the above “photocatalyst particles”, “silica particles”, “curable silicone emulsion”, and “water-soluble copper compound”, the coating liquid for external use is not limited to the following, but “inorganic oxide particles other than silica particles” ”,“ Ultraviolet absorber ”,“ light stabilizer ”,“ surfactant ”,“ organic antifungal agent ”and the like.
In addition, “photocatalyst particles”, “silica particles”, “curable silicone emulsion”, “water-soluble copper compound” -related matters, “containing inorganic oxide particles other than silica particles”, “formulation of UV absorber”, With respect to “formulation of light stabilizer”, “formulation of surfactant”, and “formulation of algaeproofing agent”, all the contents described in the section “Outside Structure” can be suitably used.

  In the exterior coating solution of the present invention, a film-forming aid having a boiling point of 100 ° C. or higher that is soluble in water or can be uniformly dispersed in water can be blended. This film-forming aid remains in the film even after most of the water has evaporated, and it provides fluidity to the film until it is completely cured, thereby repairing the film that was rough at the time of vaporization. It is given. In order to obtain a good film, the non-reactive film-forming aid must eventually disappear from the cured film, and does not contain hydroxyl groups that can be bonded to silicon atoms by transesterification. It is preferable. Therefore, the film forming aid is preferably an organic solvent having a boiling point of 100 ° C. or higher, preferably 100 to 250 ° C., particularly 100 to 200 ° C. If the boiling point is too high, it may easily remain in the film. Specifically, alcohols such as 1-butanol, isobutyl alcohol, 2-pentanol, 3-pentanol, isopentyl alcohol, methyl lactate, ethyl lactate, and 3-methyl-3-methoxybutanol, 1,2-propane Polyols such as diol, 1,3-butanediol 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2-methyl-2,4-pentanediol, glycerin, trimethylolpropane, Ethylene glycol derivatives such as 2-butoxyethanol, 2-phenoxyethanol, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, diethylene glycol monobutyl ether acetate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 1-methoxy-2 Propylene glycol derivatives such as methyl ethyl acetate, 1-ethoxy-2-methyl ethyl acetate, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monomethyl ether acetate, 3-methoxybutyl Examples include butylene glycol derivatives such as acetate, ketones such as cyclohexanone, esters such as butyl acetate, isobutyl acetate, γ-butyrolactone, propylene carbonate, and dibutyl phthalate. In particular, alkylene glycol derivatives such as 2-ethoxyethyl acetate, 2-butoxyethyl acetate, diethylene glycol monobutyl ether acetate, 1-ethoxy-2-methylethyl acetate, dipropylene glycol monomethyl ether acetate are leveling properties. To preferred. Since these organic solvents are inferior in water solubility as compared with low boiling alcohols such as methanol and ethanol, they do not impair the stability of the emulsion and contribute only to the formation of a uniform film.

  The amount of the film forming aid added is preferably 0 to 20 parts by weight, particularly 1 to 15 parts by weight, based on 100 parts by weight of the silicone resin. If added in excess of 20 parts by weight, the amount of the film-forming auxiliary agent remaining in the film even after the completion of curing increases, so that the characteristics of the film may be insufficient.

  The solvent of the exterior coating liquid of the present invention is mainly water. As a result, it is possible to effectively prevent the odor and environmental pollution associated with the volatilization and evaporation of organic substances during coating film formation.

  Moreover, the solid content concentration of the exterior coating liquid is not particularly limited, but is preferably 1 to 10% by mass because it is easy to apply. The coating solution for the exterior is analyzed for the constituents in the coating fluid for the exterior by separating the coating solution into a particle component and a filtrate by ultrafiltration, and analyzing each of them by infrared spectroscopy, gel permeation chromatography, fluorescence X It can be evaluated by analyzing by spectrum analysis etc. and analyzing the spectrum.

  It should be noted that the contents described in the sections of “Exterior” and “External Coating Liquid” can be arbitrarily combined.

Manufacturing method of outer structure The outer structure of the present invention can be easily manufactured by applying the photocatalyst coating liquid onto a substrate. 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.

Base Material The base material used in the present invention may be various materials regardless of inorganic materials, organic materials, and multilayer materials, and the shape thereof 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. As a preferable example of the base material from the viewpoint of application, outer wall, building material for outer wall, roof, roofing, roofing material, roofing material, gutter, building material for gutter, veranda fence, building material for veranda fence, veranda support, For example, building materials for veranda posts and window sashes.
In particular, the outer structure of the present invention is exposed to sunlight, and the photocatalyst is photoexcited by ultraviolet rays contained in the sunlight, causing photooxidation action such as gas decomposition and mold prevention, and deterioration of the substrate due to the ultraviolet rays. It is particularly preferable that it is used in a use form with fear.
Particularly preferably, a substrate whose surface is enamel-coated or clear-coated is most preferable because the effect of the present invention can be fully enjoyed.

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

Example 1.
Contains 1.3 parts by mass of anatase-type titanium oxide particles (average crystallite size 10 nm), 8.7 parts by mass of silica particles (average particle size 50 nm) 5% surface-coated with trifunctional silane, methyl group and phenyl group A photocatalytic aqueous coating solution having a solid content concentration of 25% by mass containing 90 parts by mass of a curable silicone emulsion, 0.007 parts by mass of a copper amine complex, and 0.003 parts by mass of a silver amine complex was prepared on a transparent acrylic substrate. And dried at 150 ° C. for 5 minutes to obtain a photocatalyst-coated body.
When the photocatalyst layer of the obtained photocatalyst-coated body was observed in cross section, the film thickness was about 7 μm, and it was observed that anatase-type titanium oxide particles and silica particles were present at a high concentration on the surface.
Moreover, when it observed from the surface of the photocatalyst coating body, the experimental stand which mounted the coating body was seen through.
About this photocatalyst coating body, the photocatalytic decomposition activity was confirmed by investigating NOx decomposition | disassembly performance. Here, the NOx decomposition function by the photocatalyst was performed by a test method of JIS R1701-1 “Testing method for air purification performance of photocatalytic material—Part 1: Nitrogen oxide removal performance”. As a result, ΔNOx exceeded 0.5 μmol, indicating a good result.
Furthermore, antifungal performance was confirmed about this photocatalyst coating body. As a pretreatment, 1 mW / cm ² of BLB light was irradiated for 24 hours, and then the antifungal test described below was performed. About the photocatalyst coating body of a magnitude | size of 50x50 mm obtained in this way, antifungal evaluation was performed as follows. Aspergillus niger (NBRC6341) pre-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 onto the photocatalyst-coated body obtained by the above method so as to be 4 to 6 × 10 ⁵ pieces / mL per 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 calculating the difference between the logarithmic value of the number of surviving bacteria obtained and the logarithmic value of the number of surviving bacteria of the photocatalyst untreated specimen. As a result, the logarithmic value exceeded 1 and showed a good result.

Example 2
Anatase-type titanium oxide particles (average crystallite diameter 10 nm) 1.3 parts by mass Silica particles 5% surface-coated with trifunctional silane (average particle size 50 nm) 8.7 parts by mass, curable silicone having a dimethylsilyl group An aqueous photocatalyst coating solution having a solid content concentration of 25% by mass containing 90 parts by mass of emulsion, 0.007 parts by mass of copper amine complex and 0.003 parts by mass of silver amine complex was prepared, and 150 ° C. on a transparent acrylic substrate. X Dry for 5 minutes to obtain a photocatalyst-coated body.
When the photocatalyst layer of the obtained photocatalyst-coated body was observed in cross section, the film thickness was about 7 μm, and it was observed that anatase-type titanium oxide particles and silica particles were present at a high concentration on the surface.
Moreover, when it observed from the surface of the photocatalyst coating body, the experimental stand which mounted the coating body was seen through.
About this photocatalyst coating body, the photocatalytic decomposition activity was confirmed by investigating NOx decomposition | disassembly performance. Here, the NOx decomposition function by the photocatalyst was performed by a test method of JIS R1701-1 “Testing method for air purification performance of photocatalytic material—Part 1: Nitrogen oxide removal performance”. As a result, ΔNOx exceeded 0.5 μmol, indicating a good result.
Furthermore, antifungal performance was confirmed about this photocatalyst coating body. As a pretreatment, 1 mW / cm ² of BLB light was irradiated for 24 hours, and then the antifungal test described below was performed. About the photocatalyst coating body of a magnitude | size of 50x50 mm obtained in this way, antifungal evaluation was performed as follows. Aspergillus niger (NBRC6341) pre-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 onto the photocatalyst-coated body obtained by the above method so as to be 4 to 6 × 10 ⁵ pieces / mL per 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 calculating the difference between the logarithmic value of the number of surviving bacteria obtained and the logarithmic value of the number of surviving bacteria of the photocatalyst untreated specimen. As a result, the logarithmic value exceeded 1 and showed a good result.

Example 3
Contains 1.3 parts by mass of anatase-type titanium oxide particles (average crystallite size 10 nm), 8.7 parts by mass of silica particles (average particle size 50 nm) 5% surface-coated with trifunctional silane, methyl group and phenyl group 90 parts by mass of curable silicone emulsion, 0.01 parts by mass of copper amine complex, and a mixed photocatalyst aqueous coating solution having a solid content concentration of 25% by mass are prepared and dried on a transparent acrylic substrate at 150 ° C. for 5 minutes. A painted body was obtained.
When the photocatalyst layer of the obtained photocatalyst-coated body was observed in cross section, the film thickness was about 7 μm, and it was observed that anatase-type titanium oxide particles and silica particles were present at a high concentration on the surface.
Moreover, when it observed from the surface of the photocatalyst coating body, the experimental stand which mounted the coating body was seen through.
About this photocatalyst coating body, the photocatalytic decomposition activity was confirmed by investigating NOx decomposition | disassembly performance. Here, the NOx decomposition function by the photocatalyst was performed by a test method of JIS R1701-1 “Testing method for air purification performance of photocatalytic material—Part 1: Nitrogen oxide removal performance”. As a result, ΔNOx exceeded 0.5 μmol, indicating a good result.
Furthermore, antifungal performance was confirmed about this photocatalyst coating body. As a pretreatment, 1 mW / cm ² of BLB light was irradiated for 24 hours, and then the antifungal test described below was performed. About the photocatalyst coating body of a magnitude | size of 50x50 mm obtained in this way, antifungal evaluation was performed as follows. Aspergillus niger (NBRC6341) pre-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 onto the photocatalyst-coated body obtained by the above method so as to be 4 to 6 × 10 ⁵ pieces / mL per 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 calculating the difference between the logarithmic value of the number of surviving bacteria obtained and the logarithmic value of the number of surviving bacteria of the photocatalyst untreated specimen. As a result, the logarithmic value exceeded 1 and showed a good result.

Claims (12)

It is an exterior equipped with a photocatalyst layer on the substrate surface,
The photocatalyst layer is obtained by applying a photocatalyst coating liquid and drying it,
The photocatalytic coating liquid comprises photocatalytic metal oxide particles, silica particles, a curable silicone emulsion, a water-soluble copper compound, and water,
The silica particles are partially coated or modified with a substance having a hydrophobic group,
The photocatalytic metal oxide particles are photocatalytic metal oxide particles having an oxidizing power stronger than a reducing power.   The exterior according to claim 1, wherein the substance having a hydrophobic group is a silane having a hydrophobic group and / or a silicone having a hydrophobic group.   The external structure according to claim 2, wherein the silica particles have a total amount of hydroxyl groups and alkoxy groups bonded to silicon atoms of less than 6 mmol / g.   The cured product of the curable silicone emulsion is 80% by mass or more based on a total mass of the cured product of the curable silicone emulsion, the photocatalytic metal oxide particles, and the silica particles. Item 4. The external structure according to any one of Items 1 to 3.   The outer structure according to any one of claims 1 to 4, wherein the film thickness of the photocatalyst layer is more than 2 µm and less than 20 µm.   The outer structure according to any one of claims 1 to 5, wherein an average particle size of the curable silicone emulsion is larger than an average particle size of the photocatalytic metal oxide particles and the silica particles.   The exterior according to any one of claims 1 to 6, wherein the photocatalyst layer is transparent. Photocatalytic metal oxide particles;
Silica particles;
A curable silicone emulsion;
A water-soluble copper compound,
With water,
The silica particles are partially coated or modified with a substance having a hydrophobic group,
The exterior coating liquid, wherein the photocatalytic metal oxide particles are photocatalytic metal oxide particles having an oxidizing power stronger than a reducing power.   The exterior coating liquid according to claim 8, wherein the substance having a hydrophobic group is a silane having a hydrophobic group and / or a silicone having a hydrophobic group.   The photocatalyst coating liquid according to claim 9, wherein the silica particles have a total amount of hydroxyl groups and alkoxy groups bonded to silicon atoms of less than 6 mmol / g.   The cured product of the curable silicone emulsion is 80% by mass or more based on a total mass of the cured product of the curable silicone emulsion, the photocatalytic metal oxide particles, and the silica particles. Item 11. The exterior coating liquid according to any one of Items 9 or 10.   The external use according to any one of claims 9 to 11, wherein an average particle size of the curable silicone emulsion is larger than an average particle size of the photocatalytic metal oxide particles and the silica particles. Coating liquid.