JP2011050873A - Article coated with photocatalyst, and photocatalytic coating liquid - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an article coated with a photocatalyst, capable of exhibiting high photocatalytic activity of decomposing a gas even if an enamel coating layer and a clear coating layer are formed thereon each with a film thickness of greater than 2 μm to prevent the degradation of the faces of the coating layers, and a photocatalytic coating liquid. <P>SOLUTION: The article coated with the photocatalyst, including a photocatalyst layer disposed on the surface of a substrate, which photocatalyst layer is formed by applying a photocatalytic coating liquid thereonto and subsequently drying the same, with the photocatalytic coating liquid including photocatalytic titanium oxide particles, a water soluble tin compound and a curable silicone emulsion, is characterized in that the photocatalytic titanium oxide particles are partially coated or modified with a substance comprising a hydrophobic group. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a photocatalyst-coated body that is particularly excellent in harmful gas decomposability while suppressing deterioration of the substrate.
Alternatively, the present invention relates to a photocatalyst coating liquid that can be imparted by forming a coating layer with a photocatalytic function such as decomposability of harmful gas while suppressing deterioration of a base material 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.
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).

JP 2007-167718 A JP 2008-2222887 A WO99 / 28393

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.
Therefore, in the present invention, in view of the above circumstances, a photocatalyst coating capable of obtaining a high photocatalytic gas decomposition activity even when coating with a thick film exceeding 2 μm so as to suppress deterioration of the enamel coating surface or the clear coating surface. The object is to provide a body and a photocatalytic coating liquid.

  That is, the present invention is a photocatalyst-coated body provided with a photocatalyst layer on a substrate surface, the photocatalyst layer being obtained by applying a photocatalyst coating liquid and drying the photocatalyst coating liquid, A photocatalyst-coated body comprising particles, a water-soluble tin compound, and a curable silicone emulsion, wherein the photocatalytic titanium oxide particles are partially coated or modified with a substance having a hydrophobic group. is there.

  The photocatalytic coating liquid according to the present invention comprises photocatalytic titanium oxide particles, a water-soluble tin compound, a curable silicone emulsion, and water, and the photocatalytic titanium oxide particles are partially formed by a substance having a hydrophobic group. It is a photocatalyst coating liquid characterized by being coated or modified.

Photocatalyst-coated body The photocatalyst-coated body according to the present invention is a photocatalyst-coated body provided with a photocatalyst layer on a substrate surface, and the photocatalyst layer is obtained by applying a photocatalyst coating liquid and then drying, and the photocatalyst coating liquid is A photocatalytic titanium oxide particle, a water-soluble tin compound, and a curable silicone emulsion, wherein the photocatalytic titanium oxide particle is partially coated or modified with a substance having a hydrophobic group. It is a photocatalyst coating body.
By adopting such a configuration, a photocatalyst-coated body capable of obtaining a high photocatalytic gas decomposing activity even when coating with a thick film exceeding 2 μm so as to suppress the deterioration of the enamel coated surface and the clear painted surface is achieved. It becomes possible to provide.
When the photocatalytic coating solution is applied to the substrate and dried, the photocatalytic titanium oxide particles are partially coated or modified with a substance having a hydrophobic group, and are moved to the surface because of low surface energy. It's easy to do. Water-soluble tin compounds also move to the surface as the water evaporates. Therefore, the photocatalytic titanium oxide particles and the water-soluble tin compound are concentrated at a high concentration on the surface during drying.
Therefore, after the curing is completed, the silicone emulsion is concentrated at the base material side and adheres to the base material, and on the surface side, the photocatalytic titanium oxide particles are firmly fixed by the curing of the water-soluble tin compound and interact with each other. As a result, the gas decomposition activity is specifically improved.

According to a preferred embodiment of the present invention, the curable silicone emulsion contained in the photocatalyst coating solution is such that the cured product 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 titanium 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 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 titanium oxide particles include anatase type titanium oxide, rutile type titanium oxide, brookite type titanium oxide, particles obtained by combining a plurality of these particles, copper, platinum Particles that are composite or doped with metals such as iron, palladium, silver, and gold, and particles that are partially coated with silane, silicone, or hydrolyzable metal salts, and modified with particles can be suitably used. is there.

  According to a preferred embodiment of the present invention, the photocatalytic titanium 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 titanium 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 substance having a hydrophobic group that partially coats or modifies the photocatalytic titanium oxide particles, for example, 1 to 3 functional silane, silicone and the like can be suitably used.
The amount of the substance used for the coating or modification treatment in the photocatalytic titanium oxide particles made of the substance having a hydrophobic group is preferably 0.1 to 20% by mass, more preferably 1 with respect to the amount of the photocatalytic titanium oxide particles. -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.

  According to a preferred embodiment of the present invention, the content of the photocatalytic titanium oxide particles is a dry mass (solid content mass), and the oxide conversion of the curable silicone emulsion, the photocatalytic titanium oxide particles, and the water-soluble tin compound. More than 0.1% by mass and less than 15% by mass, and more preferably more than 0.5% by mass and less than 5% by mass with respect to the total mass of the amount. 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 tin compound, tin chloride, tin sulfate, tin acetate and the like 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 causing the curing reaction, there is an organic cross-linked portion by emulsion polymerization.
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, and 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 and dialkyl sulphosuccinates, zwitterionic surfactants such as amino acid types and betaine types, Radical polymerizable (meth) acrylate containing a hydrophilic group such as sulfonate, polyoxyethylene chain, quaternary ammonium salt in the molecule described in JP-A-8-27347 DOO, can indicate styrene, 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, inorganic oxide particles may be contained in the photocatalyst layer. The inorganic oxide particles are not particularly limited as long as they are inorganic oxide particles capable of forming a layer together with the photocatalyst particles, and any kind of inorganic oxide particles can be used. Examples of such inorganic oxide particles include silica, alumina, zirconia, ceria, yttria, tin oxide, iron oxide, manganese oxide, nickel oxide, cobalt oxide, hafnia and other single oxide particles; and titanic acid Examples thereof include composite oxide particles such as barium, calcium silicate, aluminum borate, and potassium titanate.

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

  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 photocatalytic activity and / or the expression of hydrophilicity. For example, the photocatalyst is 0.001 to 10% by mass, preferably Is preferably contained in an amount of 0.01 to 5% by 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) , Nippon Ciba-Geigy Co., Ltd.), TINUVIN-328 (product name, manufactured by Ciba Japan Co., Ltd.), TINUVIN-928 (product name, This produced by Ciba Geigy 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 photocatalytic activity and / or the expression of hydrophilicity. -10% by mass, preferably 0.01-5% by mass.
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 Japan Co., Ltd., 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 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, -teto Such as methyl-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 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.

Photocatalytic coating liquid The photocatalytic coating liquid according to the present invention comprises photocatalytic titanium oxide particles, a water-soluble tin compound, a curable silicone emulsion, and water, and the photocatalytic titanium oxide particles have a hydrophobic group. It is a photocatalyst coating liquid characterized in that it is partially coated or modified with a substance having it.
By adopting such a configuration, a photocatalyst-coated body capable of obtaining a high photocatalytic gas decomposing activity even when coating with a thick film exceeding 2 μm so as to suppress the deterioration of the enamel coated surface and the clear painted surface is achieved. It becomes possible to provide.
When the photocatalytic coating solution is applied to the substrate and dried, the photocatalytic titanium oxide particles are partially coated or modified with a substance having a hydrophobic group, and are moved to the surface because of low surface energy. It's easy to do. Water-soluble tin compounds also move to the surface as the water evaporates. Therefore, the photocatalytic titanium oxide particles and the water-soluble tin compound are concentrated at a high concentration on the surface during drying.
Therefore, after the curing is completed, the silicone emulsion becomes a high concentration on the substrate side and adheres to the substrate. On the surface side, the photocatalytic titanium oxide particles are firmly fixed by the curing of the water-soluble tin compound, and the interaction As a result, the gas decomposition activity is specifically improved.

According to a preferred embodiment of the present invention, the curable silicone emulsion contained in the photocatalyst coating solution contains 85% by mass or more, preferably 90% or more, of the cured product based on the dried product of the photocatalyst coating solution. To be.
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 titanium oxide particles contained in the photocatalyst layer are more than 0% by mass and less than 5% by mass with respect to the dried product of the photocatalyst coating liquid.
By doing so, deterioration of the substrate can be suppressed.

The photocatalyst coating liquid is not limited to the following, in addition to the above “photocatalytic titanium oxide particles”, “water-soluble tin compound”, “curable silicone emulsion”, “inorganic oxide particles”, “metal or metal compound” , “Ultraviolet absorbers”, “light stabilizers”, “surfactants”, “organic antifungal agents”, and the like.
Matters related to “photocatalytic titanium oxide particles”, “water-soluble tin compounds”, “curable silicone emulsion”, “containing inorganic oxide particles”, “addition of metal or metal compound”, “incorporation of UV absorber” As for "", "light stabilizer blending", "surfactant blending", and "algaeproofing blending", all the contents described in the section of "photocatalyst-coated body" can be preferably 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 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 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. The components in the photocatalyst coating solution are analyzed by separating the coating solution into particle components and filtrate by ultrafiltration, and analyzing each by infrared spectroscopic analysis, gel permeation chromatography, fluorescent X-ray spectroscopic analysis, etc. It can be evaluated by analyzing the spectrum.

  The contents described in the above-mentioned sections “photocatalyst-coated body” 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, exterior and painting of guard rails, interior and painting of tunnels, insulators, solar battery 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.

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

Example 1.
Anatase-type titanium oxide particles 5% surface-coated with trifunctional silane (average crystallite diameter 10 nm) 1.3 parts by mass, tin chloride 8.7 parts by mass, curable silicone emulsion containing methyl group and phenyl group 90 parts by mass A photocatalyst aqueous coating solution having a solid content concentration of 25% by mass 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 7 μm, and it was observed that anatase-type titanium oxide particles and tin oxide 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.

Example 2
Formulated with 1.3 parts by mass of anatase-type titanium oxide particles (average crystallite diameter 10 nm) 5% surface-coated with trifunctional silane, 8.7 parts by mass of tin chloride, and 90 parts by mass of curable silicone emulsion containing dimethylsilyl group A photocatalyst aqueous coating solution having a solid content concentration of 25% by mass was prepared and dried on a transparent acrylic substrate at 150 ° C. for 5 minutes to obtain a photocatalyst-coated body.
When a cross-sectional observation of the photocatalyst layer of the obtained photocatalyst-coated body was performed, the film thickness was about 7 μm, and it was observed that anatase-type titanium oxide particles and tin oxide 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.

Claims (6)

A photocatalyst-coated body provided with a photocatalyst layer on a substrate surface,
The photocatalyst layer is obtained by applying a photocatalyst coating liquid and drying it,
The photocatalytic coating solution comprises photocatalytic titanium oxide particles, a water-soluble tin compound, and a curable silicone emulsion,
The photocatalyst-coated titanium oxide particles are partially coated or modified with a substance having a hydrophobic group. 2. The photocatalyst-coated body according to claim 1, wherein a cured product of the curable silicone emulsion contained in the photocatalyst coating liquid is contained in the photocatalyst layer by 85% by mass or more.   3. The photocatalyst-coated body according to claim 1, wherein the photocatalyst layer has a thickness of more than 2 μm and less than 20 μm.   The said photocatalyst layer is transparent, The photocatalyst coating body of any one of Claims 1-3 characterized by the above-mentioned. Photocatalytic titanium oxide particles,
A water-soluble tin compound;
A curable silicone emulsion;
With water,
A photocatalytic coating liquid, wherein the photocatalytic titanium oxide particles are partially coated or modified with a substance having a hydrophobic group.   The photocatalyst coating liquid according to claim 5, wherein a cured product of the curable silicone emulsion contained in the photocatalyst coating liquid is contained in the photocatalyst layer by 85% by mass or more.