JP5391892B2 - Photocatalyst-coated body and photocatalyst coating liquid - Google Patents

Description

The present invention relates to a photocatalyst-coated body excellent in harmful gas decomposability and antifungal / algae resistance.
Alternatively, the present invention relates to a photocatalyst coating solution that can impart a photocatalytic function such as harmful gas decomposability and fungiproof / algaeproofing properties to buildings, vehicles, members constituting them, and composite materials by forming a coating layer.

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 substrate, it is possible to impart a function of decomposing toxic substances such as NOx and SOx, antifungal and antialgal properties, etc. 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, the enameled or clear-coated surface is mainly composed of organic matter, so the effects of photocatalyst particles existing at the interface between the photocatalyst layer and the above-mentioned painted surface, and The problem is that the painted surface deteriorates due to the influence.

For this reason, 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 liquid 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, for example, a composition for preventing water pollution comprising silane-modified photocatalyst particles, colloidal silica, and silicone polymer emulsion particles. Things are known (Japanese Patent Laid-Open No. 2008-31297).
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 2008-31297 Patent 3985164 JP 2004-51644 A Japanese Patent Laid-Open No. 10-244166

However, when Cu and / or oxides thereof are added to a photocatalyst as disclosed in Japanese Patent Application Laid-Open No. 2008-31297, silver is reduced by the photocatalytic action, and an antifungal / algae-proof effect is expected. , The effect becomes weaker.
Therefore, in view of the above circumstances, an object of the present invention is to provide a photocatalyst-coated body and a photocatalyst coating liquid that are excellent in harmful gas decomposability and antifungal / algae-proof properties while suppressing deterioration of the substrate.

  That is, the photocatalyst-coated body of the present invention is a photocatalyst-coated body comprising a base material and a photocatalyst layer provided on the base material, and the photocatalyst layer is dried by applying a photocatalyst coating liquid. The obtained photocatalyst coating liquid comprises photocatalyst particles made of a metal oxide partially coated or modified with a substance having a hydrophobic group, a silicone emulsion, and a water-soluble silver compound, and The photocatalyst particles are photocatalyst particles having a higher oxidizing power than a reducing power.

  The photocatalyst coating solution of the present invention comprises photocatalyst particles made of a metal oxide partially coated or modified with a substance having a hydrophobic group, a silicone emulsion, and a water-soluble silver compound, and The photocatalyst particles are photocatalyst particles having a stronger oxidizing power than a reducing power.

Photocatalyst-coated body The photocatalyst-coated body of the present invention is a photocatalyst-coated body including a base material and a photocatalyst layer provided on the base material, and the photocatalyst layer is dried after applying a photocatalyst coating liquid. The photocatalyst coating liquid obtained by the process comprises photocatalyst particles made of a metal oxide partially coated or modified with a substance having a hydrophobic group, a silicone emulsion, and a water-soluble silver compound, and The photocatalyst particles are photocatalyst particles having an oxidizing power stronger than a reducing power.
With such a configuration, it is possible to provide a photocatalyst-coated body and a photocatalyst coating liquid that are excellent in harmful gas decomposability and mold-proof / algae-proof properties while suppressing deterioration of the substrate.
The reason is considered as follows. When the photocatalyst coating liquid is applied to the substrate and dried, the water-soluble water soluble in the 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 silver compound moves to the surface. As a result, the photocatalytic metal oxide particles and the silver compound are present at a high concentration while being separated from each other on the surface of the coated body when drying is completed. Here, in the present invention, the photocatalyst particles are photocatalyst particles whose oxidizing power is stronger than the reducing power. Therefore, the silver compound is present at an appropriate distance, so that the photocatalyst and the silver are hardly generated with almost no photoreduction action of silver. The photocatalytic oxidative power can be enhanced by the interaction with, and it is 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, silica particles are further added to the photocatalyst-coated body.
By doing so, the film strength is improved.

The substance having a hydrophobic group may be a silane having a hydrophobic group and / or a silicone having a hydrophobic group.
By doing so, it becomes easy to control the coating and modification forms on the surface of the photocatalytic metal oxide particles.

According to a preferred embodiment of the present invention, the cured product of the curable silicone emulsion contained in the photocatalyst coating liquid is contained in the photocatalyst layer at 85% by mass or more, preferably 90% or more.
Here, the mass of hardened | cured material means the constant value at the time of 105 degreeC drying.
By setting it to 85% or more, a high photocatalytic decomposition activity can be obtained even in a film having a long transfer process on the surface, 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% or more, a high photocatalytic decomposition activity can be obtained even in a film having a long movement process on the surface, 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 photocatalytic metal oxide particles contained in the photocatalyst layer are more than 0% by mass and less than 5% by mass.
By doing so, deterioration of the substrate can be suppressed.

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 movement of the photocatalytic metal oxide particles to the surface becomes remarkable.
Accordingly, the photocatalytic metal oxide particles easily move to the surface, and a photocatalyst-coated body capable of obtaining a high degree of photocatalytic decomposition activity even in a film having a long moving process on a surface such as a thick film exceeding 2 μm is provided. It will be easier to do.

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 for a film with a long travel distance on the surface, such as a thick film exceeding 2 μm while effectively utilizing its design properties. It becomes easier to provide a photocatalyst-coated body capable of this.

  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. Suitable metal oxide particles, particles obtained by combining a plurality of these particles, particles obtained by partially covering these particles with silica, alumina, or the like 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 photocatalytic metal oxide particles preferably have an average crystallite size 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.

  As the water-soluble silver compound of the present invention, preferred examples of the silver (I) compound include gluconate, sulfate, malate, lactate, nitrate, formate, acetate, chelate and the like. it can.

According to a preferred embodiment of the present invention, a nonionic surfactant or an anionic surfactant may be added to the photocatalyst coating liquid separately from the emulsifier added during the emulsion production process.
As the nonionic surfactant, a surfactant having an HLB value of 10 to 20 is preferable. As the type, for example, polyoxyethylene lauryl ether, polyoxyethylene tridecyl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, Polyoxyethylene alkyl phenol ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene laurate, polyoxyethylene stearate, polyoxyethylene alkyl phenyl ether, polyoxyethylene oleate, sorbitan alkyl ester, poly Oxyethylene sorbitan alkyl ester, polyether modified silicone, polyester modified Ricone, sorbitan laurate, sorbitan stearate, sorbitan palmitate, sorbitan oleate, sorbitan sesquioleate, polyoxyethylene sorbitan laurate, polyoxyethylene sorbitan stearate, polyoxyethylene sorbitan palmitate, polyoxyethylene sorbitan oleate , Glycerol stearate, polyglycerol fatty acid ester, alkyl alkylolamide, lauric acid diethanolamide, oleic acid diethanolamide, oxyethylene dodecylamine, polyoxyethylene dodecylamine, polyoxyethylene alkylamine, polyoxyethylene octadecylamine, polyoxy Ethylene alkylpropylenediamine, polyoxyethyleneoxypropylene block polymer Mer, polyoxyethylene stearate and the like can be suitably used.
Examples of the anionic surfactant include polyoxyethylene alkylphenyl ether ammonium salt of sulfonic acid, sodium salt of polyoxyethylene alkylphenyl ether of sulfonic acid, fatty acid sodium soap, fatty acid potassium soap, dioctyl sodium sulfosuccinate, alkyl sulfate, alkyl ether sulfate, alkyl Sulfate 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, acyl Sodium methyl taurate, sodium lauroyl methyl taurate , Sodium dodecylbenzenesulfonate, disodium lauryl sulfosuccinate, disodium polyoxyethylene sulfosuccinate lauryl, polycarboxylic acid, oleoyl sarcosine, amide ether sulfate, lauroyl sarcosinate, sulfo FA ester sodium salt, etc. Is available.

  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).

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

  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 addition to the functional group that causes the curing reaction, the curable silicone emulsion includes an organic cross-linked portion by emulsion polymerization and a surface portion for dispersing in water.
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. As long as it is a crosslinked part produced by radical polymerization, it is not particularly limited to a hydrocarbon group, and a combination of various modifying groups can be suitably used.
The surface portion is formed so that, for example, an emulsifier such as a surfactant is fixed and can be dispersed in water.

  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 Japan Co., Ltd.), isooctyl-3- [3- (2H-benzotriazol-2-yl) -5-tert-butyl- 4-hydroxyphenyl] propionate (manufactured by Ciba Japan Co., Ltd., product name: TINUVIN-384), 2- (3-dodecyl-5-methyl-2-hydroxyphenyl) benzotriazole (manufactured by Ciba Japan Co., Ltd., 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'-octoxyphenyl) benzo Riazole, 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 Japan Co., Ltd., product name: TINUVIN-900), and 2- (2′-hydroxy-5′-methacryloxyethylphenyl) -2H-benzotriazole (Otsuka Chemical Co., Ltd.) Product name: RUVA-93), 2- (2′-hydroxy-5′-methacryloxyethyl-3-tert-butylphenyl) -2H-benzotriazo 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 Japan Co., Ltd., product name: CGL-104) In addition to these (co) polymers, TINUVIN-384-2 (product name, manufactured by Ciba Japan), TINUVIN-99-2 (product name, manufactured by Ciba Japan), TINUVIN-109 (product name) , Ciba Japan Co., Ltd.), TINUVIN-328 (Product Name, Ciba Japan Co., Ltd.), TINUVIN-928 (Product Name, Ciba) Made Yapan Co., Ltd.), 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 (product name: TINUVIN-292, manufactured by Ciba Japan Co., Ltd.), bis (1-octoxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, TINUVIN-123 (product name, Ciba Japan Co., Ltd.), TINUVIN-111FDL (product name, manufactured by Ciba Japan Co., Ltd.), TINUVIN 292 (product name, manufactured by Ciba Japan Co., Ltd.), 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 Such as ru-4-iminopiperidyl methacrylate, 4-cyano-2,2,6,6-tetramethyl-4-piperidyl methacrylate, 4-cyano-1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, etc. Examples thereof include polymerizable hindered amine ultraviolet absorbers and their (co) polymers.

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

  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.

Photocatalyst coating liquid The photocatalyst coating liquid according to the present invention comprises photocatalyst particles made of a metal oxide partially coated or modified with a substance having a hydrophobic group, a silicone emulsion, and a water-soluble silver compound. In addition, the photocatalyst particle is a photocatalyst coating liquid characterized in that the photocatalyst particle has an oxidizing power stronger than a reducing power.
With such a configuration, it is possible to provide a photocatalyst-coated body and a photocatalyst coating liquid that are excellent in harmful gas decomposability and mold-proof / algae-proof properties while suppressing deterioration of the substrate.
The reason is considered as follows. When the photocatalyst coating liquid is applied to the substrate and dried, the water-soluble water soluble in the 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 silver compound moves to the surface. As a result, the photocatalytic metal oxide particles and the silver compound are present at a high concentration while being separated from each other on the surface of the coated body when drying is completed. Here, in the present invention, the photocatalyst particles are photocatalyst particles whose oxidizing power is stronger than the reducing power. Therefore, the silver compound is present at an appropriate distance, so that the photocatalyst and the silver are hardly generated with almost no photoreduction action of silver. The photocatalytic oxidative power can be enhanced by the interaction with, and it is 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, silica particles are further added to the photocatalyst-coated body.
By doing so, the film strength is improved.

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 coating and modification forms on the surface of the photocatalytic metal oxide particles.

According to a preferred embodiment of the present invention, the cured product of the curable silicone emulsion contained in the photocatalyst coating solution is contained in an amount of 85% by mass or more, preferably 90% or more, based on the dried product of the photocatalyst coating solution. Like that.
Here, the mass of hardened | cured material means the constant value at the time of 105 degreeC drying.
By setting it to 85% or more, a high photocatalytic decomposition activity can be obtained even in a film having a long transfer process on the surface, 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% or more, a high photocatalytic decomposition activity can be obtained even in a film having a long movement process on the surface, 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 photocatalytic metal oxide particles contained in the photocatalyst coating solution are more than 0% by mass and less than 5% by mass with respect to the dried product of the photocatalyst coating solution.
By doing so, deterioration of the substrate can be suppressed.

According to a preferred embodiment of the present invention, the average particle size of the curable silicone emulsion is made larger than the average particle size of the photocatalytic metal oxide particles.
By doing so, movement becomes remarkable on the surface of the photocatalytic metal oxide particles.
Accordingly, the photocatalytic metal oxide particles are easily transferred to the surface without being bound by the silicone emulsion, and a high photocatalytic degradation activity can be obtained even in a film having a long moving process on the surface, such as a thick film exceeding 2 μm. It is easier to provide a possible photocatalytic coating composition.

The photocatalyst coating liquid is not limited to the following, in addition to the above “photocatalyst metal oxide particles”, “water-soluble silver compound”, “curable silicone emulsion”, but “silica particles”, “inorganic oxidation other than silica particles” Product particles "," surfactants "," metals or metal compounds "," ultraviolet absorbers "," light stabilizers "," organic antifungal agents ", and the like.
Items related to “photocatalytic metal oxide particles”, “water-soluble silver compounds”, “curable silicone emulsion”, “silica particles”, “containing inorganic oxide particles other than silica particles”, “metal or metal” For "compound addition", "surfactant blending", "UV absorber blending", "light stabilizer blending", and "algaeproofing blending", all of those mentioned in the section "Photocatalyst coating" The contents can be suitably used.

  In the photocatalyst coating liquid 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 aid remaining in the film after the curing is increased, and the film characteristics may be insufficient.

  The solvent of the photocatalyst 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 photocatalyst coating liquid is not particularly limited, but it is preferably 10 to 60% by mass in terms of easy application. Photocatalyst coating liquid In addition, the components of the photocatalyst coating liquid are analyzed by separating the coating liquid into particle components and filtrate by ultrafiltration, and analyzing each of them by infrared spectroscopic analysis, gel permeation chromatography, fluorescent X-ray spectroscopic analysis, etc. And can be evaluated by analyzing the spectrum.

  The contents described in the above-mentioned “photocatalyst-coated bodies” and “photocatalyst coating liquid” can be arbitrarily combined.

Method for Producing Photocatalyst-Coated Body The photocatalyst-coated body of the present invention can be easily produced by applying the photocatalyst coating liquid on 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. Preferred examples of base materials from the viewpoint of applications include building materials, building exteriors and interiors, window frames, window glass, structural members, exteriors and coatings of vehicles, exteriors of machinery and articles, dust covers and coatings, traffic signs, Various display devices, advertising towers, sound insulation walls for roads, sound insulation walls for railways, bridges, guard rail exteriors and paintings, tunnel interiors and paintings, insulators, solar cell covers, solar water heater heat collection covers, plastic houses, vehicle lighting Covers, outdoor lighting fixtures, tables, bathroom materials, kitchen panels, sinks, ranges, ventilation fans, air conditioning, filters, toilets, bathtubs, and films, sheets, seals and the like for attachment to the surface of the article.

In particular, the photocatalyst-coated body 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 to use it in a usage form that may occur.
Such applications include building materials, building exteriors, window frames, window glass, structural members, exterior and painting of vehicles, exteriors of machinery and goods, traffic signs, advertising towers, signboards, 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, greenhouses, vehicular lighting lamp covers, outdoor lighting fixtures, road pavements and the like.
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.
1.3 parts by mass of anatase-type titanium oxide particles (average crystallite size 10 nm) coated with 5% of trifunctional silane and 8.7 masses of silica particles (average particle size 50 nm) coated with 5% of trifunctional silane Part, methylphenyl silicone emulsion 90 parts by mass, polyoxyethylene alkyl ether 5% by mass, silver amine complex 0.007 parts by mass, silver amine complex 0.003 parts by mass, solid content concentration 25% by mass photocatalytic aqueous coating A liquid was prepared and dried on a transparent acrylic substrate 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 3 μm, and it was observed that anatase-type titanium oxide particles and silica particles were present at high concentrations 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 harmful substance removal performance by a photocatalyst was confirmed by investigating NOx decomposition performance. Here, the NOx decomposition function by the photocatalyst was performed by the 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. 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 calculating the difference between the logarithmic value of the obtained number of surviving bacteria 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)

A photocatalyst-coated body comprising a substrate and a photocatalyst layer provided on the substrate,
The photocatalyst layer is obtained by applying a photocatalyst coating liquid and then drying,
The photocatalyst coating liquid comprises photocatalyst particles made of a metal oxide partially coated or modified with a substance having a hydrophobic group, a silicone emulsion, a water-soluble silver compound, and water, and ,
The photocatalyst particles are anatase-type titanium oxide particles.   2. The photocatalyst-coated body according to claim 1, wherein silica particles are further added to the photocatalyst-coated body.   The photocatalyst-coated body according to any one of claims 1 and 2, 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 according to any one of claims 1 to 3, wherein a cured product of the curable silicone emulsion contained in the photocatalyst coating liquid is contained in the photocatalyst layer in an amount of 85% by mass or more. body.   The photocatalyst-coated body according to any one of claims 1 to 4, wherein the photocatalytic metal oxide particles contained in the photocatalyst layer are more than 0% by mass and less than 5% by mass. The photocatalyst-coated body according to any one of claims 1 to 5, wherein the photocatalyst layer has a thickness of more than 2 µm and less than 20 µm . The photocatalyst-coated body according to any one of claims 1 to 6 , wherein the photocatalyst layer is transparent. Photocatalyst particles made of a metal oxide partially coated or modified with a substance having a hydrophobic group;
Silicone emulsion,
A water-soluble silver compound and water,
And the said photocatalyst particle is an anatase type titanium oxide particle, The photocatalyst coating liquid characterized by the above-mentioned. Furthermore, the silica catalyst is added, The photocatalyst coating liquid of Claim 8 characterized by the above-mentioned. It said substance having a hydrophobic group, a photocatalyst coating liquid according to any one of claims 8 or 9, characterized in that a silicone having a silane and / or a hydrophobic group having a hydrophobic group. The cured product of the curable silicone emulsion contained in the photocatalyst coating liquid, any one of claims 8 to 10, characterized in that contained more than 85% by weight, based on the dry matter of the photocatalyst coating liquid The photocatalyst coating liquid described in 1. Photocatalytic metal oxide particles contained in the photocatalyst coating liquid, any claims 8 to 11, characterized in that the dry matter of the photocatalyst coating liquid is less than 5 wt% exceeding 0 wt% 2. The photocatalyst coating solution according to item 1.