JP2008142655A - Water-based photocatalyst composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocatalyst composition and a coating material excellent in dispersion stability and efficiently retaining photocatalytic activity and/or hydrophilicity for a long period and a coated article. <P>SOLUTION: The photocatalyst is a modified photocatalyst obtained by modification treatment by (1) a modification agent compound having an organosilane unit and/or (2) at least one kind compound selected from a group consisting of oxides of silicon and/or aluminum, wherein the primary particle diameter of the photocatalyst is 1 to 100 nm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

Since the present invention exhibits a substance decomposing action and a surface hydrophilizing action by light energy, it is based on a photocatalyst represented by titanium oxide, which is known to be applied in the fields of environmental purification, antifouling, antifogging and the like. It is related with the immobilization technology to the material surface.
Specifically, the substrate and the photocatalyst composition coating film (hereinafter referred to as coating) are maintained while maintaining the decomposition activity (photocatalytic activity) and / or hydrophilicity of the organic substance based on the photocatalyst immobilized on the substrate surface. The present invention relates to a modified photocatalyst excellent in durability and a modified photocatalyst composition containing the modified photocatalyst. Furthermore, the present invention relates to a water-based photocatalyst composition having a low environmental load and capable of being firmly fixed under mild conditions, and a coated product coated with the photocatalyst composition.

A photocatalyst is a substance that undergoes an oxidation or reduction reaction upon irradiation with light. That is, when light (excitation light) with an energy larger than the energy gap between the conduction band and the valence band (ie, a short wavelength) is irradiated, excitation (photoexcitation) of electrons in the valence band occurs, resulting in conduction. It is a substance that can generate electrons and holes. At this time, various chemical reactions are performed using the reducing power of electrons generated in the conduction band and / or the oxidizing power of holes generated in the valence band. Can do.
The photocatalytic activity means that an oxidation or reduction reaction is caused by light irradiation. It is known that the photocatalytic activity exhibits an organic substance decomposing action and a surface hydrophilizing action.

Photocatalysts having such functions are applied to fields such as environmental purification, antifouling, and antifogging. For example, Patent Document 1 proposes an outdoor display panel that includes a surface layer portion containing photocatalyst particles and has a surface that is self-cleaned by rain (self-cleaning), and a cleaning method therefor. By providing a surface layer containing a photocatalyst, the surface of the surface layer portion exhibits hydrophilicity in response to photoexcitation of the photocatalyst, so that deposits and / or contaminants are deposited when the surface of the outdoor display panel is exposed to rainfall. It can be washed away by raindrops.
By the way, when a photocatalyst is applied to fields such as environmental purification, antifouling, and antifogging, the photocatalyst immobilization technology plays a very important role. That is, (a) it is necessary to firmly fix to a substrate without impairing the photocatalytic activity, and (b) stability that does not deteriorate the substrate and the coating itself by the photocatalytic action.

  In order to fix such a photocatalyst, a method in which a protective layer is interposed between the base material and the photocatalyst-containing surface layer portion has been proposed. However, this method has a drawback in that workability is poor due to an increase in the coating process. is there. For example, Patent Document 2 proposes a multilayer photocatalytic film in which a metal oxide vapor deposition layer is provided on a base material and a photocatalytic layer is provided thereon. Alternatively, Patent Document 3 proposes a photocatalyst carrier stacked so that a photocatalyst layer is formed in the vicinity of the surface of the polymer layer. A method of mixing a photocatalyst in a resin paint and coating the resin paint on a substrate has also been proposed. However, in these methods, in order to show sufficient photocatalytic activity and / or hydrophilicity, it is necessary to reduce the use of a resin paint. In this case, the durability of the substrate, the hardness of the coating, and the adhesion are not sufficient. There is a disadvantage of not. When the resin paint is used more frequently, the photocatalytic activity and / or hydrophilicity becomes insufficient, and it is not easy to balance these physical properties.

In addition, most of these paints use an organic solvent, and there is a problem that an organic solvent having a problem of toxicity or environmental pollution and a risk of fire is released into the atmosphere at the time of use. Furthermore, from the viewpoint of solvent resistance, there is also a problem that it is difficult to use a substrate on which a resin substrate or an organic film is formed.
Therefore, it has been very difficult to achieve a photocatalyst excellent in durability of the substrate and the coating in an aqueous system while maintaining the decomposition activity (photocatalytic activity) and / or hydrophilicity of the organic substance.

Japanese Patent Laid-Open No. 9-230810 Japanese Patent Laid-Open No. 11-348172 JP 2000-93809 A

  An object of the present invention is to provide a modified photocatalyst excellent in durability of a substrate and a coating while maintaining the decomposition activity (photocatalytic activity) and / or hydrophilicity of an organic substance based on the photocatalyst immobilized on the surface of the member. It is to provide a modified photocatalyst composition comprising. Furthermore, it is providing the water-based photocatalyst composition with little environmental impact, and the coating material which coated the said photocatalyst composition.

As a result of intensive studies aimed at solving the above problems, the present inventors have reached the present invention. That is, the present invention
1) (I) From a triorganosilane unit represented by the following formula (1), a monooxydiorganosilane unit represented by the following formula (2), and a dioxyorganosilane unit represented by the following formula (3) Modified by one or more modifier compounds selected from the group consisting of compounds having at least one structural unit selected from the group consisting of: and (II) a modifier compound consisting of oxides of silicon and / or aluminum. A modified photocatalyst being treated, wherein the photocatalyst has a primary particle size of 1 to 100 nm,
R ₃ Si- (1)
(In the formula, each R is independently a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, or a linear or branched carbon group having 1 to 30 carbon atoms. (A fluoroalkyl group, a linear or branched alkenyl group having 2 to 30 carbon atoms, a phenyl group, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group.)
_{- (R 2 SiO) - (} 2)
(In the formula, R is as defined in the above formula (1).)

（式中、Ｒは上記式（１）で定義した通りである。）

(In the formula, R is as defined in the above formula (1).)

2) The modified photocatalyst according to 1), wherein the modifier compound contains one or more linear or branched fluoroalkyl groups,
3) The modified photocatalyst according to 1) or 2), wherein the number average dispersed particle size of the photocatalyst is 1 to 400 nm,
4) The ratio (L / D) of the particle length (L) to the particle diameter (D) of the modified photocatalyst particles is from 1/1 to 20/1, according to any one of 1) to 3) Modified photocatalyst,
5) The modified photocatalyst according to any one of 1) to 4), wherein the photocatalyst is titanium oxide.

6) The modified photocatalyst according to any one of 1) to 4), wherein the photocatalyst is anatase-type titanium oxide;
7) The modified photocatalyst according to any one of 1) to 4), wherein the photocatalyst is rutile titanium oxide,
8) A modified photocatalyst composition comprising the modified photocatalyst according to any one of 1) to 7) and an aqueous binder,
9) A photocatalyst-coated product obtained by coating the substrate with the modified photocatalyst composition described in 8),
10) The photocatalyst-coated product according to 9), which has anisotropy with respect to the distribution of the modified photocatalyst, and the concentration of the modified photocatalyst is higher on the other exposed surface than on the surface in contact with the substrate.
It is invention of this.

  The present invention can provide a modified photocatalyst that is excellent in dispersion stability in a photocatalyst composition and that effectively retains photocatalytic activity and / or hydrophilicity. In addition, it is possible to provide a photocatalyst composition that can be cured with a small environmental load and is excellent in durability of a substrate and a coating. Furthermore, the composition is excellent in weather resistance, water resistance, and transparency, and can provide a coated product that is resistant to staining over a long period of time.

Hereinafter, the present invention will be described in detail.
The photocatalyst that can be used for the modified photocatalyst in the present invention is a valence electron when irradiated with light (excitation light) having an energy (ie, short wavelength) larger than the energy gap between the conduction band and the valence band of the crystal. A substance that can generate conduction electrons and holes due to excitation (photoexcitation) of electrons in the band. Among them, a semiconductor compound having a band gap energy of 1.2 to 5.0 eV is preferable in view of the balance between the ability to cause oxidation and reduction reaction by light irradiation and the energy of light necessary for generating holes and electrons. A semiconductor compound of 5 to 4.1 eV is more preferable.

Photocatalyst The example _{TiO 2, ZnO, SrTiO 3,} CdS, GaP, InP, GaAs, BaTiO 3, BaTiO 4, BaTi 4 O 9, K 2 NbO 3, Nb 2 O 5, Fe 2 O 3, Ta 2 O 5 , K ₃ Ta ₃ Si ₂ O ₃ , WO ₃ , SnO ₂ , Bi ₂ O ₃ , BiVO ₄ , NiO, Cu ₂ O, SiC, MoS ₂ , InPb, RuO ₂ , CeO ₂ , etc., and further Ti, Nb, Ta And layered oxides having at least one element selected from V (Japanese Patent Laid-Open Nos. 62-74452, 2-172535, 7-24329, and 8-89799) JP-A-8-89800, JP-A-8-89804, JP-A-8-198061, JP-A-9-248465, JP-A-1 No. 0-99694, JP-A-10-244165, etc.). In addition, a photocatalyst coated with a metal such as Pt, Rh, Ru, Nb, Cu, Sn, Ni, or Fe and / or a metal oxide added thereto or immobilized thereon, or a photocatalyst coated with porous calcium phosphate ( JP-A-11-267519) can also be used.
When a visible light responsive photocatalyst capable of developing photocatalytic activity and / or hydrophilicity by irradiation with visible light (for example, a wavelength of about 400 to 800 nm) is selected as the photocatalyst of the present invention, the photocatalyst composition of the present invention is selected. The photocatalyst member treated with is preferable because the environmental purification effect and the antifouling effect in a place where ultraviolet rays such as indoors are not sufficiently irradiated are very large.

Any visible light responsive photocatalyst can be used as long as it exhibits photocatalytic activity and / or hydrophilicity with visible light. For example, TaON, LaTiO ₂ N, CaNbO ₂ N, LaTaON ₂ , and CaTaO ₂ N can be used. Such as oxysulfide compounds such as Sm ₂ Ti ₂ S ₂ O ₇ (see, for example, JP 2002-233770 A), CaIn ₂ O ₄ , and SrIn _2. O ₄ , ZnGa
Oxides containing metal ions in the d10 electronic state such as ₂ O ₄ and Na ₂ Sb ₂ O ₆ (see, for example, JP 2002-59008 A), titanium oxide precursors in the presence of nitrogen-containing compounds such as ammonia and urea (Titanium oxysulfate, titanium chloride, alkoxytitanium, etc.) and nitrogen-doped titanium oxide obtained by firing high surface titanium oxide (for example, JP 2002-29750 A, JP 2002-87818 A, JP 2002-154823 A). And sulfur-doped titanium oxide obtained by calcining a titanium oxide precursor (titanium oxysulfate, titanium chloride, alkoxytitanium, etc.) in the presence of a sulfur compound such as thiourea, Oxygen defect type acid obtained by hydrogen plasma treatment of titanium oxide or heat treatment under vacuum Titanium (see, for example, JP-A-2001-98219), photocatalyst particles are treated with a halogenated platinum compound (see, for example, JP-A-2002-239353), or treatment with tungsten alkoxide (JP-A-2001-286755). The surface-treated photocatalyst obtained by (see) can be preferably mentioned.
In order to improve the performance of the photocatalyst, a metal such as platinum, gold, silver, copper, palladium, rhodium, and ruthenium or an oxide of the metal may be deposited on the surface of the photocatalyst particles.

The photocatalyst used in the present invention is required to have a primary particle diameter in the range of 1 to 100 nm from the viewpoint of performance as a photocatalyst and from the viewpoint of dispersibility. It is more preferably in the range of 1 to 50 nm, and further preferably in the range of 5 to 50 nm. The primary particle diameter of the photocatalyst can be measured with a transmission electron microscope.
As the form of the photocatalyst used in the present invention, any of powder, dispersion and sol can be used.
In general, fine photocatalyst particle powder forms secondary particles in which a plurality of particles are strongly agglomerated, so there are many surface properties to be wasted, and it is very difficult to disperse into individual primary particles. is there.
In contrast, in the case of a photocatalyst sol, the photocatalyst particles do not dissolve and exist in a form close to primary particles, so that the surface characteristics can be used effectively, and the modified photocatalyst produced therefrom has dispersion stability, film formability, etc. It can be preferably used because it effectively exhibits various functions. Here, the photocatalyst sol is obtained by dispersing photocatalyst particles in water and / or an organic solvent at a solid content of 0.01 to 70% by weight, preferably 0.1 to 50% by weight.

  As the photocatalyst used in the present invention, a photocatalyst having a number average dispersed particle size of a mixture of primary particles and secondary particles of 400 nm or less is preferable because the surface characteristics of the modified photocatalyst can be effectively used. In particular, when a photocatalyst having a number average dispersed particle size of 100 nm or less is used, it is very preferable because a film having excellent transparency can be obtained from the resulting modified photocatalyst. More preferably, a photocatalyst of 80 nm or less and 3 nm or more, and more preferably 50 nm or less and 3 nm or more is suitably selected. The number average dispersed particle size of the photocatalyst can be measured with a wet particle size analyzer (for example, Nikkiso Microtrac UPA-9230). These photocatalysts are preferably sols or dispersions of photocatalysts. Further, it is more preferably a photocatalyst hydrosol using water as a dispersion medium. (Here, substantially using water as a dispersion medium means that about 80% or more of water is contained in the dispersion medium.)

The preparation of such sols is known and can be easily produced (JP-A 63-17221, JP-A 7-819, JP-A 9-165218, JP-A 11-43327, etc.). For example, metatitanic acid produced by heating and hydrolyzing an aqueous solution of titanium sulfate or titanium tetrachloride is neutralized with aqueous ammonia, and the precipitated hydrous titanium oxide is filtered, washed, and dehydrated to obtain aggregates of titanium oxide particles. It is done. Titanium oxide hydrosol can be obtained by peptizing the agglomerates under the action of nitric acid, hydrochloric acid, ammonia or the like and performing hydrothermal treatment. In addition, as titanium oxide hydrosols, titanium oxide particles are peptized under the action of acids and alkalis, and dispersion stabilizers are used as necessary without using acids or alkalis. A sol dispersed in water under water can also be used. Further, an anatase-type titanium oxide sol having excellent dispersion stability even in an aqueous solution having a pH near neutral and having a particle surface modified with a peroxo group can be easily obtained by the method proposed in JP-A-10-67516. it can.

The titanium oxide hydrosol described above is commercially available as a titania sol. (For example, product name “STS-01” / Ishihara Sangyo Co., Ltd./Japan, product name “TKS203” / Taika Co., Ltd./Japan, etc.)
The solid content in the titanium oxide hydrosol is 50% by weight or less, preferably 35% by weight or less. More preferably, it is 35% by weight or less and 0.1% by weight or more. Such a hydrosol has a relatively low viscosity (20 ° C.) and may be, for example, in the range of about 2000 cps to 0.5 cps. Preferably it is 1000 cps-1 cps, More preferably, it is 500 cps-1 cps.
Further, for example, a cerium oxide sol (JP-A-8-59235) or a layered oxide sol having at least one element selected from Ti, Nb, Ta, and V (JP-A-9-25123, JP-A-9-9). -67124, JP-A-9-227122, JP-A-9-227123, JP-A-10-259023, etc.) are also disclosed in the same manner as titanium oxide sol. .

  The modified photocatalyst of the present invention can be obtained by modifying the above-mentioned photocatalyst with a modifier compound. By carrying out the modification treatment with the compound, the dispersion stability when the photocatalyst sol is concentrated / diluted or mixed with an aqueous binder can be maintained. In addition, the photocatalyst is dispersed not only in the photocatalyst composition comprising the modified photocatalyst and the aqueous binder or in the photocatalyst-coated product coated with the photocatalyst composition by the modification treatment, but also from the inside to the surface of the coating film. This is effective in that it has the effect of inclining the distribution of.

Examples of the modifier compound include (I) a triorganosilane unit represented by the following formula (1), a monooxydiorganosilane unit represented by the following formula (2), and a dioxyorgano represented by the following formula (3). It is selected from compounds having at least one structural unit selected from the group consisting of silane units.
R ₃ Si- (1)
(In the formula, each R is independently a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, or a linear or branched carbon group having 1 to 30 carbon atoms. (A fluoroalkyl group, a linear or branched alkenyl group having 2 to 30 carbon atoms, a phenyl group, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group.)
_{- (R 2 SiO) - (} 2)
(In the formula, R is as defined in the above formula (1).)

（式中、Ｒは上記式（１）で定義した通りである。）

(In the formula, R is as defined in the above formula (1).)

Among the modifier compounds, a modifier compound having the structure of the above formula (2) or the above formula (3) is preferable from the viewpoint of reactivity with the photocatalyst and dispersibility in the photocatalyst sol.
The photocatalyst modification treatment with the modifier compound can be performed by mixing the photocatalyst sol and the modifier compound at any temperature from 5 ° C. to 100 ° C. and stirring them. The modifier compound can be directly mixed with the photocatalyst sol, or can be mixed after being dissolved in a solvent. In addition, the modification treatment can be performed in a neutral pH range, and can also be performed in an acidic or alkaline pH range. From the viewpoint of shortening the denaturation time, the denaturation is preferably performed while heating to any temperature between 40 ° C and 90 ° C.
In the modification treatment with the modifier compound, the weight ratio of photocatalyst / modifier is preferably in the range of 100 / 0.5 to 100/50, more preferably in the range of 100/1 to 100/30. When the modification is performed within the above range, the effect of dispersion stability and the performance of the photocatalyst can be expressed more effectively.

  The modified photocatalyst of the present invention is preferably further modified with (II) an oxide of silicon and / or aluminum from the viewpoint of dispersion stability at a neutral pH. The modification treatment with silicon and / or aluminum oxide can be carried out, for example, by a method of neutralizing a photocatalyst sol by adding an alkali metal silicate or alkali metal aluminate such as sodium silicate or sodium aluminate. (Japanese Patent Laid-Open Nos. 10-158015 and 2005-170687). In the modification treatment with the oxide of silicon and / or aluminum, the weight ratio of the photocatalyst to the oxide of silicon and / or aluminum is preferably in the range of 100/1 to 100/30, and in the range of 100/1 to 100/20. It is more preferable that When the modification is performed within the range, the effect of dispersion stability and the performance of the photocatalyst can be effectively expressed.

Furthermore, as the modifier compound, it is preferable to use a modifier containing one or more linear or branched fluoroalkyl groups in the compound. By introducing a fluoroalkyl group, the dispersion stability of the photocatalyst is further improved, and the photocatalyst is surfaced in a photocatalyst composition comprising a modified photocatalyst and an aqueous binder in an aqueous binder or in a photocatalyst-coated product coated with the paint. This is effective in increasing the effect of uneven distribution.
The fluoroalkyl group is not limited and may be any of a monofluoroalkyl group, a difluoroalkyl group, and a trifluoroalkyl group, but a trifluoroalkyl group that increases the amount of fluorine in the modifier may be introduced. Most effective. The alkyl group is a linear or branched alkyl group having 1 to 30 carbon atoms.

The modification treatment for the photocatalyst in the present invention is either (I) a modification treatment with at least one modifier compound having an organosilane unit or (II) a modification treatment with an oxide of silicon and / or aluminum. And then the other can be performed, or the denaturation by both can be performed simultaneously.
Furthermore, it is possible to carry out the denaturation treatment in multiple stages of three or more stages. From the viewpoint of reactivity between the photocatalyst and the modifier, the reactivity between the modifiers and the dispersibility of the modified photocatalyst, at least one or more having an organosilane unit after first being modified with an oxide of silicon and / or aluminum It is more preferable to perform the modification treatment with the modifier compound.
(II) For the modification with silicon and / or aluminum oxide, a commercially available photocatalyst that has been modified in advance with an oxide of silicon can also be used.

The photocatalyst used in the present invention has a particle shape (L / D) ratio of 1/1 from the viewpoint of the specific surface area of the photocatalyst particles and the particle orientation effect from the viewpoint of the particle orientation effect. It is preferably in the range of 20/1. More preferable L / D is in the range of 1/1 to 15/1, and further preferable L / D is in the range of 1/1 to 10/1.
As these photocatalysts used in the present invention, TiO ₂ (titanium oxide) is preferable because it is harmless and excellent in chemical stability. In addition, titanium oxide having any crystal structure of anatase, rutile, or brookite can be used, and a mixture of titanium oxides having a plurality of crystal structures can also be used.
Use of anatase-type titanium oxide as the titanium oxide is preferable in that the photocatalytic activity and / or hydrophilicity is more strongly expressed. In addition, it is preferable to use rutile type titanium oxide as the titanium oxide in terms of excellent weather resistance while exhibiting photocatalytic activity and / or hydrophilicity.
The crystal structure of titanium oxide can be identified by X-ray diffraction. In addition to normal titanium oxide, titanium oxide includes those called hydrous titanium oxide, hydrated titanium oxide, orthotitanic acid, metatitanic acid, and titanium hydroxide.

The aqueous binder used in the present invention refers to a binder resin solution or a dispersion of a binder resin substantially using water as a dispersion medium. For example, polyvinyl alcohol, cation-modified polyvinyl alcohol, polyvinyl alcohol derivatives such as silanol-modified polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamides, starch and starch derivatives, cellulose derivatives such as carboxymethyl cellulose, hydroxyethyl cellulose, casein, gelatin, in an aqueous medium Conventionally known poly (meth) acrylate type, polyvinyl acetate type, vinyl acetate-acrylic type, ethylene vinyl acetate type, silicone type, polybutadiene type, styrene butadiene type, NBR type obtained by radical polymerization, anionic polymerization, cationic polymerization, etc. , Polyvinyl chloride, chlorinated polypropylene, polyethylene, polystyrene, vinylidene chloride, polystyrene- (meth) acryl Over preparative system, a styrene - maleic anhydride copolymer-based or the like, silicone-modified acrylic-based, fluorine - acrylic, acrylic silicone, epoxy - and the like aqueous dispersion of the modified copolymer such as an acrylic.
Further, the aqueous binder can contain a compound having a functional group that reacts with a functional group contained in the binder resin. Examples include (poly) isocyanate compounds, (poly) epoxy compounds, amino compounds, (poly) carboxy compounds, (poly) hydroxy compounds, glycol compounds, silanol compounds, silyl compounds, alkoxy compounds, (meth) acrylates, and the like. Can do.

  Moreover, an emulsifier and a dispersion stabilizer can also be used from the viewpoint of dispersion stability in the photocatalyst composition comprising the modified photocatalyst and the aqueous binder in the present invention. Examples of the emulsifier include acidic emulsifiers such as alkylbenzenesulfonic acid, alkylsulfonic acid, alkylsulfosuccinic acid, polyoxyethylene alkylsulfuric acid, polyoxyethylene alkylarylsulfuric acid, polyoxyethylene distyrylphenyl ether sulfonic acid, and alkali metal of acidic emulsifier. (Li, Na, K, etc.) salts, ammonium salts of acidic emulsifiers, anionic surfactants such as fatty acid soaps, quaternary ammonium salts such as alkyltrimethylammonium bromide, alkylpyridinium bromide, imidazolinium laurate, pyridinium Salt, imidazolinium salt type cationic surfactant, polyoxyethylene alkyl aryl ether, polyoxyethylene sorbitan fatty acid ester, polyoxyethyleneoxypropylene Lock copolymers may be exemplified a reactive emulsifier or the like having a nonionic surface active agent and a radical polymerizable double bond, such as polyoxyethylene distyryl phenyl ether.

Examples of the reactive emulsifier having a radical polymerizable double bond include a vinyl monomer having a sulfonic acid group or a sulfonate group, a vinyl monomer having a sulfate ester group, an alkali metal salt thereof, an ammonium salt, Examples include vinyl monomers having a nonionic group such as oxyethylene, and vinyl monomers having a quaternary ammonium salt.
Examples of the dispersion stabilizer include various water-soluble oligomers selected from the group consisting of polycarboxylic acids and sulfonates, polyvinyl alcohol, hydroxyethyl cellulose, starch, maleated polybutadiene, maleated alkyd resin, polyacrylic acid ( Salt), polyacrylamide, synthetic or natural water-soluble or water-dispersible acrylic resins, and various water-soluble polymer substances that are water-soluble or water-dispersible. These emulsifiers and dispersion stabilizers can be used singly or as a mixture of two or more.
A small amount of an organic solvent such as alcohol can be added to the photocatalyst composition of the present invention for the purpose of controlling the interaction between the photocatalyst and the aqueous binder.

Examples of the substrate on which the photocatalyst composition of the present invention is coated include organic substrates such as synthetic resins, natural resins, and fibers, inorganic substrates such as metals, ceramics, glass, stone, cement, and concrete, and combinations thereof. Etc.
As the synthetic resin, a thermoplastic resin and a curable resin (thermosetting resin, photocurable resin, moisture curable resin, etc.) can be used. For example, silicone resin, acrylic resin, methacrylic resin, fluororesin, Alkyd resin, amino alkyd resin, vinyl resin, polyester resin, styrene-butadiene resin, polyolefin resin, polystyrene resin, polyketone resin, polyamide resin, polycarbonate resin, polyacetal resin, polyether ether ketone resin, polyphenylene oxide resin, polysulfone resin, Examples thereof include polyphenylene sulfone resin, polyether resin, polyvinyl chloride resin, polyvinylidene chloride resin, urea resin, phenol resin, melamine resin, epoxy resin, urethane resin, and silicone-acrylic resin.
Examples of the natural resin include cellulose resins, isoprene resins such as natural rubber, and protein resins such as casein.
In the present invention, the surface of the resin plate or fiber may be subjected to surface treatment such as corona discharge treatment, flame treatment, or plasma treatment, but these surface treatments are not essential.
The type and film thickness of the substrate used in the present invention can be properly used depending on the application.

  In addition, the photocatalyst composition of the present invention is usually added to and blended with paints and molding resins, for example, thickeners, leveling agents, thixotropic agents, antifoaming agents, depending on the application and method of use. Agent, freezing stabilizer, matting agent, crosslinking reaction catalyst, pigment, curing catalyst, crosslinking agent, filler, anti-skinning agent, dispersant, wetting agent, light stabilizer, antioxidant, UV absorber, rheology control Agent, antifoaming agent, film-forming aid, rust preventive agent, dye, plasticizer, lubricant, reducing agent, antiseptic agent, antifungal agent, deodorant agent, anti-yellowing agent, antistatic agent or charge preparation agent Etc. can be selected and combined in accordance with each purpose.

The coated article containing the photocatalyst composition of the present invention is excellent in photocatalytic activity and / or hydrophilicity and in weather resistance, water resistance and optical properties.
The photocatalytic activity can be determined, for example, by measuring the decomposability of an organic substance such as a dye during light irradiation on the material surface. A surface having photocatalytic activity exhibits excellent decomposition activity and contamination resistance of contaminating organic substances.
The hydrophilicity can be determined by measuring the contact angle at the time of light irradiation on the material surface. A surface with excellent hydrophilicity exhibits a low contact angle. From the viewpoint of antifouling properties, the contact angle during light irradiation is preferably 60 ° C. or less.
Here, the light irradiation is performed using a light source having a higher energy than the band gap energy of the photocatalyst. As a light source, light such as black light, xenon lamp, mercury lamp and LED can be used in addition to light obtained in a general residential environment such as sunlight and indoor lighting.

The coated product of the present invention, for example, after applying the photocatalyst composition to a substrate and drying at a low temperature of 20 ° C. to 80 ° C., preferably 20 ° C. to 500 ° C., more preferably 40 ° C. to 250 ° C. It can be obtained by performing a heat treatment, ultraviolet irradiation, or the like to form a coating film of a contamination prevention layer on the substrate. Examples of the coating method include spray spraying, flow coating, roll coating, brush coating, dip coating, spin coating, screen printing, casting, gravure printing, flexographic printing, and the like.
When forming the composition for water pollution prevention of this invention as a coating film on a base material, it is preferable that the thickness of this coating film is 0.05-100 micrometers, Preferably it is 0.1-10 micrometers. The thickness is preferably 100 μm or less from the viewpoint of transparency, and in order to exhibit functions such as antifouling properties and photocatalytic activity, the thickness is preferably 0.05 μm or more.

In this specification, the expression “coating film” is used, but it is not necessarily a continuous film, and may be a discontinuous film, an island-shaped dispersion film, or the like.
The manufacturing method of the coated material of this invention is not limited to the case where the photocatalyst composition of this invention is formed on a base material. The base material and the composition for preventing water pollution of the present invention may be molded at the same time, for example, integrally molded. Moreover, you may shape | mold a base material after shape | molding the photocatalyst composition of this invention. Alternatively, the coated product and the base material may be individually molded and then manufactured by adhesion, fusion, or the like.

The present invention will be specifically described by the following examples, reference examples and comparative examples. The gist of the present invention is not limited to the following examples. In addition, the measurement or evaluation described in the following Examples and Comparative Examples was performed by the following method.
1. Average primary particle size The sample was dropped on a mesh for an electron microscope and air-dried. The sample on the mesh was observed with an ultra high resolution transmission electron microscope (H-9000UHR manufactured by Hitachi) at an acceleration voltage of 300 kV and 1,000,000 times. 100 arbitrary particles were extracted from the observed image, and the average primary particle diameter was determined.

2. Number average particle size The sample was diluted with a suitable solvent so that the solid content in the sample was 0.5% by mass, and measured using a wet particle size analyzer (Microtrack UPA-9230 manufactured by Nikkiso).
3. Ratio of particle length (L) to particle diameter (D) (L / D)
1. The ratio of the particle length (L) to the particle diameter (D) was determined using arbitrary 100 particles extracted from the electron microscope image observed in (1).
4). Contact angle of water to the surface of the coating film A drop of deionized water was placed on the surface of the coating film, left at 23 ° C. for 1 minute, and then measured using a CA-X150 contact angle meter manufactured by Kyowa Interface Science.
The smaller the contact angle of water with the coating film, the higher the hydrophilicity of the coating film surface.

5. Transparency Using a Nippon Denshoku Industries turbidimeter NDH2000, haze values and total light transmittance were measured according to JIS-K7105.
6). Color difference The color difference from the standard plate was determined using a color guide manufactured by BYK Gardner.
7). Weather resistance An exposure test (black panel temperature 63 ° C., rainfall 18 minutes / 2 hours) was conducted using a sunshine weather meter manufactured by Suga Test Instruments. The contact angle of water before exposure and after 500 hours of exposure is In the above method, the transparency is set to the above 5. The change before and after exposure was evaluated.

8). Contamination Resistance After the test plate was attached to a fence facing a general road (truck traffic of about 500 to 1000 vehicles / day) for 6 months, the degree of contamination was evaluated visually.
◎: No dirt, ○: Little dirt, △: Slightly rain streaks, x: Significant rain streaks Photocatalytic activity The test plate was irradiated with black light for 3 hours. Thereafter, 0.1 ml of a 100 mg / l methylene blue aqueous solution was dispensed, and a 35 ml × 35 ml transparent polyester film was coated thereon. Above 6. After the initial color difference was measured by this method, the light of black light was irradiated and the color difference was measured every 5 minutes. The change from the initial color difference was determined by ΔE, and photocatalytic activity was evaluated by ΔE after 1 hour. The greater the ΔE, the higher the activity.
At this time, the light of the FL20S BLB type black light manufactured by Toshiba Lighting & Technology is used as the black light, and the UVR-2 type UV intensity meter manufactured by Topcon, Japan {as the light receiving unit, the UD-36 type light receiving unit manufactured by Topcon, Japan (wavelength 310). Was used so that the ultraviolet intensity measured using 1) was adjusted to 1 mW / cm ² .

[Production Example 1]
Synthesis of Modified Titanium Oxide Hydrosol (A-1) LS-8600 [1,3,5,7-tetramethylcyclotetrasiloxane trade name (Shin-Etsu Chemical Co., Ltd.) was added to a reactor having a reflux condenser, a thermometer and a stirring device. 474 g, LS-8620 [trade name of octamethylcyclotetrasiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.)] 76.4 g, LS-8490 [1,3,5-trimethyl-1,3,5-triphenylcyclo After charging 408 g of trisiloxane trade name (manufactured by Shin-Etsu Chemical Co., Ltd.), LS-7130 [trade name of hexamethyldisiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.) 40.5 g, and 20 g of sulfated zirconia, and stirring at 50 ° C. for 3 hours The mixture was further stirred for 5 hours while being heated to 80 ° C. After filtering the sulfated zirconia, low-boiling components were removed under vacuum at 130 ° C., and a methylhydrogensiloxane-methylphenylsiloxane-dimethylsiloxane copolymer having a weight average molecular weight of 6600 and a Si—H group content of 7.93 mmol / g ( 780 g of a synthetic silicone compound) was obtained.

The synthetic silicone compound 40 g was put into a reactor equipped with a reflux condenser, a thermometer and a stirring device, and the temperature was raised to 80 ° C. with stirring. To this, UNIOX PKA-5118 [trade name of polyoxyethylene allyl methyl ether (manufactured by NOF Corporation), weight average molecular weight 800] 200 g and dehydrated methyl ethyl ketone 200 g, chloroplatinic acid hexahydrate 5 mass%, isopropanol solution A solution in which 1.0 g was mixed was added over about 1 hour under stirring, and the stirring was further continued at 80 ° C. for 5 hours, followed by cooling to room temperature, whereby the Si—H group-containing compound solution (1) was obtained. Obtained.
When 100 g of water was added to 4 g of the obtained Si—H group-containing compound solution (1), a transparent aqueous solution was obtained.
Further, 8 g of butyl cellosolve was added to and mixed with 3.97 g of the obtained Si—H group-containing compound solution (1), and then 8 ml of 1N aqueous sodium hydroxide solution was added to generate hydrogen gas. 21.0 ml. The Si—H group content per gram of the Si—H group-containing compound solution (1) determined from this hydrogen gas production amount was 0. The content was 22 mmol / g (the Si—H group content calculated per 1 g of the synthetic silicone compound was about 2.37 mmol / g).

A reactor equipped with a reflux condenser, a thermometer, and a stirring device was charged with 78.1 g of TKS-203 [trade name of anatase-type titanium oxide hydrosol (manufactured by Teika)] and 221.9 g of water, and then synthesized. 41.3 g of the Si-H group-containing compound solution (1) was added with stirring at 40 ° C. over about 30 minutes, and stirring was further continued at 40 ° C. for 12 hours. Then, methyl ethyl ketone was removed by distillation under reduced pressure, Water was added to obtain a modified photocatalyst hydrosol (A-1) having a very good dispersibility of 5% by mass. At this time, the amount of hydrogen gas produced by the reaction of the Si—H group-containing compound solution (1) was 210 ml at 20 ° C. Further, when the obtained modified titanium oxide hydrosol (A-1) was coated on a KBr plate and the IR spectrum was measured, the disappearance of absorption of Ti—OH groups (3630 to 3640 cm ⁻¹ ) was observed.
Moreover, the particle size distribution of the obtained modified photocatalyst hydrosol (A-1) is a single dispersion (number average particle diameter is 55 nm), and further, the single dispersion of TKS203 before the modification treatment (number average particle diameter is 12 nm). It was confirmed that the particle size distribution of the particles moved parallel to the larger particle size side.
In addition, the number average molecular weight of the modified photocatalyst hydrosol (A-1) obtained above is a measured numerical value when the concentration is 5% by mass, while that shown in Table 1 shows that the concentration and 0.5% by mass. % Is a measured numerical value, and the former value is smaller because the concentration is larger. (same as below.)
Table 1 shows the properties of the modified photocatalyst hydrosol (A-1).

[Production Example 2]
Synthesis of Modified Titanium Oxide Hydrosol (B-1) In a reactor equipped with a reflux condenser, a thermometer and a stirring device, MPT-422 [trade name of anatase-type titanium oxide hydrosol (manufactured by Ishihara Sangyo), TiO ₂ after putting 14 those are surface modified with weight% of SiO _2] 77.3 g of water 231.9g against which the production example 1 synthesized Si-H group-containing compound solution (1) 41 .3 g was added at 40 ° C. with stirring over about 30 minutes, and further stirring was continued at 40 ° C. for 12 hours. Then, methyl ethyl ketone was removed by distillation under reduced pressure, water was added, and 5% by mass was very dispersible. The modified photocatalyst hydrosol (B-1) having a good quality was obtained. At this time, the amount of hydrogen gas produced by the reaction of the Si—H group-containing compound solution (1) was 210 ml at 20 ° C. Further, when the obtained modified titanium oxide hydrosol (B-1) was coated on a KBr plate and the IR spectrum was measured, disappearance of Ti—OH group absorption (3630 to 3640 cm ⁻¹ ) was observed.
Moreover, the particle size distribution of the obtained modified photocatalyst hydrosol (B-1) is monodisperse (number average particle size is 50 nm), and further monodisperse of MPT422 before modification (number average particle size is 9 nm). It was confirmed that the particle size distribution of the particles moved parallel to the larger particle size side.
Table 1 shows the characteristics of the modified photocatalyst hydrosol (B-1).

[Production Example 3]
Synthesis of Modified Titanium Oxide Hydrosol (C-1) To a reactor equipped with a reflux condenser, a thermometer and a stirrer, TSK-5 [trade name of rutile titanium oxide hydrosol (made by Ishihara Sangyo), TiO ₂ On the other hand, the surface is modified with 14 wt% SiO ₂ ] After 51.5 g and 257.5 g of water were added, the Si—H group-containing compound solution (1) 41 synthesized in [Production Example 1] was added thereto. .3 g was added at 40 ° C. with stirring over about 30 minutes, and further stirring was continued at 40 ° C. for 12 hours. Then, methyl ethyl ketone was removed by distillation under reduced pressure, water was added, and 5% by mass was very dispersible. The modified photocatalyst hydrosol (A-3) with good quality was obtained. At this time, the amount of hydrogen gas produced by the reaction of the Si—H group-containing compound solution (1) was 210 ml at 20 ° C. Moreover, when the obtained modified titanium oxide hydrosol (C-1) was coated on a KBr plate and the IR spectrum was measured, the disappearance of absorption of Ti—OH groups (3630 to 3640 cm ⁻¹ ) was observed.
Moreover, the particle size distribution of the obtained modified photocatalyst hydrosol (C-1) is a single dispersion (number average particle diameter is 50 nm), and further, the single dispersion of MPT422 before the modification treatment (number average particle diameter is 9 nm). It was confirmed that the particle size distribution of the particles moved parallel to the larger particle size side.
Table 1 shows the properties of the modified photocatalyst hydrosol (C-1).

[Production Example 4]
Into a reactor equipped with a reflux condenser, a thermometer and a stirring device, 78.1 g of TKS-203 [trade name of anatase-type titanium oxide hydrosol (manufactured by Teika)] and 221.9 g of water were added, and then KBM7103 [Product name of 3,3,3-trifluoropropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)] 0.77 g was added at 80 ° C. with stirring over about 30 minutes, and further stirred at 80 ° C. for 3 hours. As a result, a modified photocatalyst hydrosol (A-2) having a very good dispersibility of 5% by mass was obtained. When the obtained modified titanium oxide hydrosol (A-2) was coated on a KBr plate and the IR spectrum was measured, a decrease in absorption of Ti—OH groups (3630 to 3640 cm ⁻¹ ) was observed.
Moreover, the particle size distribution of the obtained modified photocatalyst hydrosol (A-2) is monodisperse (number average particle size is 53 nm), and further monodispersion of TKS203 before modification (number average particle size is 12 nm). It was confirmed that the particle size distribution of the particles moved parallel to the larger particle size side.
Table 1 shows the characteristics of the modified photocatalytic hydrosol (A-2).

[Production Example 5]
Reflux condenser, into a reactor equipped with a thermometer and a stirrer, MPT-422 [anatase titanium oxide hydrosol trade name (manufactured by Ishihara Sangyo Kaisha), is surface-modified with respect to TiO ₂ in 14 weight% of SiO ₂ After adding 77.3 g and 231.9 g of water, 0.77 g of KBM7103 [trade name of 3,3,3-trifluoropropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)] was added to 80 ° C. The mixture was added over about 30 minutes with stirring, and the stirring was further continued at 80 ° C. for 3 hours to obtain 5% by mass of a modified photocatalyst hydrosol (B-2) having very good dispersibility. When the obtained modified titanium oxide hydrosol (A-2) was coated on a KBr plate and the IR spectrum was measured, a decrease in absorption of Ti—OH groups (3630 to 3640 cm ⁻¹ ) was observed.
Moreover, the particle size distribution of the obtained modified photocatalyst hydrosol (B-2) is a single dispersion (number average particle diameter is 53 nm), and further, the single dispersion of TKS203 before the modification treatment (number average particle diameter is 12 nm). It was confirmed that the particle size distribution of the particles moved parallel to the larger particle size side.
Table 1 shows the characteristics of the modified photocatalytic hydrosol (B-2).

[Production Example 6]
In a reactor equipped with a reflux condenser, a thermometer and a stirrer, TSK-5 [trade name of rutile titanium oxide hydrosol (manufactured by Ishihara Sangyo), surface-modified with 14 wt% SiO ₂ with respect to TiO ₂ After adding 51.5 g and 257.5 g of water, 0.77 g of KBM7103 [trade name of 3,3,3-trifluoropropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd.)] was added to 80 ° C. The mixture was added over about 30 minutes with stirring, and further stirred at 80 ° C. for 3 hours to obtain 5% by mass of a modified photocatalyst hydrosol (C-2) with very good dispersibility. When the obtained modified titanium oxide hydrosol (C-2) was coated on a KBr plate and the IR spectrum was measured, a decrease in absorption of the Ti—OH group (3630 to 3640 cm ⁻¹ ) was observed.
Moreover, the particle size distribution of the obtained modified photocatalyst hydrosol (C-2) is a single dispersion (number average particle diameter is 53 nm), and further, the single dispersion of TKS203 before the modification treatment (number average particle diameter is 12 nm). It was confirmed that the particle size distribution of the particles moved parallel to the larger particle size side.
Table 1 shows the characteristics of the modified photocatalytic hydrosol (C-2).

[Production Example 7]
Synthesis of aqueous binder emulsion (a) After charging 1600 g of ion-exchanged water and 2 g of dodecylbenzenesulfonic acid into a reactor having a reflux condenser, a dropping tank, a thermometer and a stirring device, the temperature was increased to 80 ° C. with stirring. Warm up. To this, a mixed solution of 85 g of butyl acrylate, 135 g of phenyltrimethoxysilane, 1.3 g of 3-methacryloxypropyltrimethoxysilane, 100 g of diethylacrylamide, 3 g of acrylic acid, a reactive emulsifier (trade name “ADEKA rear soap SR-1025 “Asahi Denka Co., Ltd., 25% solid content aqueous solution) 13 g, ammonium persulfate 2% by weight aqueous solution 40 g, and ion-exchanged water 1500 g of a mixed solution of about 2 with the temperature in the reaction vessel maintained at 80 ° C. It was dripped simultaneously over time. Further, stirring was continued for about 2 hours in a state where the temperature in the reaction vessel was 80 ° C., then cooled to room temperature, filtered through a 100-mesh wire mesh, and the solid content was adjusted to 10.0% by mass with ion-exchanged water. A polymer emulsion particle (a) aqueous dispersion having a number average particle diameter of 100 nm was obtained.

[Production Example 8]
Synthesis of Aqueous Binder Emulsion (b) 1000 g of ion-exchanged water was charged into a reactor having a reflux condenser, a dropping tank, a thermometer and a stirring device, and then the temperature was heated to 80 ° C. with stirring. To this, 100 g of diethylacrylamide, 3 g of acrylic acid, 13 g of reactive emulsifier (trade name “ADEKA rear soap SR-1025”, manufactured by Asahi Denka Co., Ltd., 25% solid content aqueous solution), 2% by weight aqueous solution of ammonium persulfate 4
A mixed solution of 0 g and 500 g of ion-exchanged water and 100 g of butyl acrylate were simultaneously added dropwise over about 2 hours while maintaining the temperature in the reaction vessel at 80 ° C. Further, stirring was continued for about 2 hours in a state where the temperature in the reaction vessel was 80 ° C., then cooled to room temperature, filtered through a 100-mesh wire mesh, and the solid content was adjusted to 10.0% by mass with ion-exchanged water. A polymer emulsion particle (b) aqueous dispersion having a number average particle diameter of 80 nm was obtained.

[Production Example 9]
Synthesis of water-based binder (c) 356 parts of methanol was added to 208 parts of tetraethoxysilane, 18 parts of water and 18 parts of 0.01N hydrochloric acid were mixed, and mixed well using a disper. The obtained liquid was heated in a 60 ° C. constant temperature bath for 2 hours to obtain a silicone resin. Next, to this silicone resin, 10% of γ-glycidoxypropyltrimethoxysilane (thermal decomposition temperature 280 ° C.) as a thermally decomposable material is added to the total solid content of the inorganic paint to be obtained. The aqueous binder (c) was obtained by diluting so that a content might become 13 to 15%.

[Example 1]
Water was added to silica-modified anatase-type titanium oxide hydrosol (MPT-422, manufactured by Ishihara Sangyo Co., Ltd.) to prepare 5% titanium oxide hydrosol (B). 14 g of the titanium oxide hydrosol, 100 g of the aqueous binder emulsion produced in Production Example 7 and water-dispersed colloidal silica having a number average particle size of 12 nm (trade name “Snowtex O”, manufactured by Nissan Chemical Industries, Ltd., solid content 20%) 60 g was mixed to prepare a modified photocatalyst composition.
The modified photocatalyst composition was bar-coated on a 10 cm × 10 cm PET film so as to have a film thickness of 2 μm, and then dried at room temperature for 1 week to obtain a test plate.
The evaluation results are shown in Table 2.

[Example 2]
Water was added to silica-modified rutile-type titanium oxide hydrosol (TSK-5, manufactured by Ishihara Sangyo) to prepare 5% titanium oxide hydrosol (C). 14 g of the titanium oxide hydrosol, 100 g of the aqueous binder emulsion produced in Production Example 7 and water-dispersed colloidal silica having a number average particle size of 12 nm (trade name “Snowtex O”, manufactured by Nissan Chemical Industries, Ltd., solid content 20%) 60 g was mixed to prepare a modified photocatalyst composition.
The modified photocatalyst composition was bar-coated on a 10 cm × 10 cm PET film so as to have a film thickness of 2 μm, and then dried at room temperature for 1 week to obtain a test plate.
The evaluation results are shown in Table 2.
[Example 3] to [Example 8]
Example 1 is different from Example 1 except that any one of the modified titanium oxide hydrosols synthesized in [Production Example 1] to [Production Example 6] is used in place of the silica-modified anatase-type titanium oxide hydrosol (B). Similarly, a composition was prepared and a test plate was prepared. The evaluation results are shown in Table 2.

[Comparative Example 1]
A composition was prepared in the same manner as in Example 1 except that titanium oxide was not used in Example 1, and a test plate was prepared.
The evaluation results are shown in Table 2.
[Comparative Example 2]
A composition was prepared in the same manner as in Example 1 except that unmodified titanium oxide hydrosol (TKS-203) was used as titanium oxide in Example 1, and a test plate was prepared.
The evaluation results are shown in Table 2.

[Example 9]
Water was added to silica-modified anatase-type titanium oxide hydrosol (MPT-422, manufactured by Ishihara Sangyo Co., Ltd.) to prepare 5% titanium oxide hydrosol (B). 14 g of the titanium oxide hydrosol, 100 g of the aqueous binder emulsion produced in Production Example 8, and water-dispersed colloidal silica having a number average particle size of 12 nm (trade name “Snowtex O”, manufactured by Nissan Chemical Industries, Ltd., solid content 20%) 60 g was mixed to prepare a modified photocatalyst composition.
The modified photocatalyst composition was bar-coated on a 10 cm × 10 cm PET film so as to have a film thickness of 2 μm, and then dried at room temperature for 1 week to obtain a test plate.
The evaluation results are shown in Table 3.

[Example 10]
Water was added to silica-modified rutile-type titanium oxide hydrosol (TSK-5, manufactured by Ishihara Sangyo) to prepare 5% titanium oxide hydrosol (C). 14 g of the titanium oxide hydrosol, 100 g of the aqueous binder emulsion produced in Production Example 8, and water-dispersed colloidal silica having a number average particle size of 12 nm (trade name “Snowtex O”, manufactured by Nissan Chemical Industries, Ltd., solid content 20%) 60 g was mixed to prepare a modified photocatalyst composition.
The modified photocatalyst composition was bar-coated on a 10 cm × 10 cm PET film so as to have a film thickness of 2 μm, and then dried at room temperature for 1 week to obtain a test plate.
The evaluation results are shown in Table 3.
[Example 11] to [Example 16]
Example 9 is different from Example 9 except that any one of the modified titanium oxide hydrosols synthesized in [Production Example 1] to [Production Example 6] is used instead of using the silica-modified anatase-type titanium oxide hydrosol (B). Similarly, a composition was prepared and a test plate was prepared. The evaluation results are shown in Table 3.

[Comparative Example 3]
A composition was prepared in the same manner as in Example 9 except that titanium oxide was not used in Example 9, and a test plate was prepared.
The evaluation results are shown in Table 3.
[Comparative Example 4]
A composition was prepared in the same manner as in Example 9 except that unmodified titanium oxide hydrosol (TKS-203) was used as titanium oxide in Example 9, and a test plate was prepared.
The evaluation results are shown in Table 3.

[Example 17]
The composition was the same as in Example 1 except that water-dispersed colloidal silica (trade name “Snowtex O”, manufactured by Nissan Chemical Industries, Ltd., 20% solid content) was not used in Example 1. The test plate was prepared. The evaluation results are shown in Table 4.
[Example 18]
The composition was the same as in Example 2 except that water-dispersed colloidal silica (trade name “Snowtex O”, manufactured by Nissan Chemical Industries, Ltd., 20% solid content) was not used in Example 2. The test plate was prepared. The evaluation results are shown in Table 4.
[Example 19] to [Example 24]
Example 3 to Example 8 were carried out from Example 3 except that water-dispersed colloidal silica (trade name “Snowtex O”, manufactured by Nissan Chemical Industries, Ltd., solid content 20%) having a number average particle size of 12 nm was not used. A composition was prepared in the same manner as in Example 8, and a test plate was prepared. The evaluation results are shown in Table 4.

[Comparative Example 5]
A composition was prepared in the same manner as in Example 17 except that titanium oxide was not used in Example 17, and a test plate was prepared.
The evaluation results are shown in Table 4.
[Comparative Example 6]
A composition was prepared in the same manner as in Example 9 except that unmodified titanium oxide hydrosol (TKS-203) was used as titanium oxide in Example 17, and a test plate was prepared.
The evaluation results are shown in Table 4.

[Example 25]
Water was added to silica-modified anatase-type titanium oxide hydrosol (MPT-422, manufactured by Ishihara Sangyo Co., Ltd.) to prepare 5% titanium oxide hydrosol (B). 1 g of the titanium oxide hydrosol and 100 g of the binder produced in Production Example 9 were mixed to prepare a modified photocatalyst composition.
The modified photocatalyst composition was bar-coated on a 10 cm × 10 cm PET film so as to have a film thickness of 2 μm, and then dried at room temperature for 1 week to obtain a test plate.
The evaluation results are shown in Table 5.

[Example 26]
Water was added to silica-modified rutile type titanium oxide hydrosol (TSK-5, manufactured by Ishihara Sangyo) to prepare 5% titanium oxide hydrosol (B). 1 g of the titanium oxide hydrosol and 100 g of the binder produced in Production Example 9 were mixed to prepare a modified photocatalyst composition.
The modified photocatalyst composition was bar-coated on a 10 cm × 10 cm PET film so as to have a film thickness of 2 μm, and then dried at room temperature for 1 week to obtain a test plate.
The evaluation results are shown in Table 5.
[Example 27] to [Example 32]
Example 25 is different from Example 25 except that any one of the modified titanium oxide hydrosols synthesized in [Production Example 1] to [Production Example 6] is used instead of the silica-modified anatase-type titanium oxide hydrosol (B). Similarly, a composition was prepared and a test plate was prepared. The evaluation results are shown in Table 5.

[Comparative Example 7]
A composition was prepared in the same manner as in Example 25 except that titanium oxide was not used in Example 25, and a test plate was prepared.
The evaluation results are shown in Table 5.
[Comparative Example 8]
A composition was prepared in the same manner as in Example 25 except that unmodified titanium oxide hydrosol (TKS-203) was used as titanium oxide in Example 25, and a test plate was prepared.
The evaluation results are shown in Table 5.

  The photocatalyst composition provided by the present invention is a modified photocatalyst that has excellent dispersion stability and effectively retains photocatalytic activity and / or hydrophilicity, and can be cured with a small environmental load. It is useful as a coating agent for uses, automobiles, displays, lenses and the like.

Claims (10)

(I) A group consisting of a triorganosilane unit represented by the following formula (1), a monooxydiorganosilane unit represented by the following formula (2), and a dioxyorganosilane unit represented by the following formula (3). Modified with one or more modifier compounds selected from the group consisting of compounds having at least one structural unit selected from: and / or (II) a modifier compound consisting of oxides of silicon and / or aluminum. A modified photocatalyst having a primary particle size of 1 to 100 nm.
R ₃ Si- (1)
(In the formula, each R is independently a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, or a linear or branched carbon group having 1 to 30 carbon atoms. (A fluoroalkyl group, a linear or branched alkenyl group having 2 to 30 carbon atoms, a phenyl group, an alkoxy group having 1 to 20 carbon atoms, or a hydroxyl group.)
_{- (R 2 SiO) - (} 2)
(In the formula, R is as defined in the above formula (1).)

(In the formula, R is as defined in the above formula (1).)   The modified photocatalyst according to claim 1, wherein the modifier compound contains one or more kinds of linear or branched fluoroalkyl groups.   The modified photocatalyst according to claim 1 or 2, wherein the photocatalyst has a number average dispersed particle size of 1 to 400 nm.   The modified photocatalyst according to any one of claims 1 to 3, wherein the ratio (L / D) of the particle length (L) to the particle diameter (D) of the modified photocatalyst particles is 1/1 to 20/1. .   The modified photocatalyst according to any one of claims 1 to 4, wherein the photocatalyst is titanium oxide.   The modified photocatalyst according to any one of claims 1 to 4, wherein the photocatalyst is anatase-type titanium oxide. The modified photocatalyst according to any one of claims 1 to 4, wherein the photocatalyst is rutile titanium oxide.   A modified photocatalyst composition comprising the modified photocatalyst according to any one of claims 1 to 7 and an aqueous binder.   A photocatalyst-coated product obtained by coating the substrate with the modified photocatalyst composition according to claim 8. The photocatalyst-coated product according to claim 9, wherein the modified photocatalyst has anisotropy, and the concentration of the modified photocatalyst is higher on the other exposed surface than on the surface in contact with the substrate.