JP2006297209A - Photocatalyst - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocatalyst of which the surface exhibits photocatalytic activities and/or hydrophilicity for a long time by irradiation with light without causing deterioration in the interface between the photocatalyst and an organic substrate and which is excellent in durability to maintain high transparency. <P>SOLUTION: The photocatalyst composed of a photocatalyst particle (a), a binder component (B) and an ultraviolet absorber (U) has a mass ratio (a)/(B) of the photocatalyst particle (a) and the binder component (B) of 0.01/99.99-5/95 and a total light transmission of 95% or more and the surface exhibits the photocatalytic activities and/or hydrophilicity by irradiation with a light of energy higher than the bandgap energy of the photocatalyst particle (a). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention shows the surface of a photocatalyst represented by titanium oxide, which is known to be applied to fields such as environmental purification, antifouling, and antifogging because it exhibits a substance decomposing action and a surface hydrophilizing action by light energy. Related to immobilization technology.

  For certain substances, light having an energy larger than the energy gap (band gap) between the conduction band and valence band of the substance, that is, light having a shorter wavelength than the light corresponding to the band gap of the substance ( When excitation light is irradiated, excitation of electrons in the valence band (photoexcitation) occurs due to light energy, and electrons are generated in the conduction band and holes are generated in the valence band. At this time, various chemical reactions can be performed using the reducing power of electrons generated in the conduction band and / or the oxidizing power of holes generated in the valence band.

That is, the above substances can be used like a catalyst under excitation light irradiation. Therefore, the above substances are called photocatalysts, and titanium oxide is known as the most typical example.
Examples of chemical reactions promoted by this photocatalyst include oxidative decomposition reactions of various organic substances. Therefore, if this photocatalyst is immobilized on the surface of various base materials, various organic substances adhering to the surface of the base material can be oxidatively decomposed using light energy.

On the other hand, it is known that when a certain type of photocatalyst is irradiated with light, the hydrophilicity of the surface of the photocatalyst increases. Therefore, if this photocatalyst is immobilized on the surface of various base materials, the hydrophilicity of the surface of the base material can be enhanced by light irradiation.
In recent years, research for applying the characteristics of the above photocatalysts to various fields such as environmental purification, prevention of adhesion of dirt to the surface of various substrates and prevention of fogging has been actively conducted. Yes. In this case, a method for immobilizing the photocatalyst on the surface of various base materials plays a very important role.

Various proposals have been made so far for immobilizing a photocatalyst, and as one particularly useful method, a surface of a substrate is coated with a composition containing a photocatalyst to form a film containing the photocatalyst. Thus, a method of fixing the photocatalyst to the surface of the base material has attracted attention.
When immobilizing the photocatalyst by this method, (1) the photocatalyst can be firmly immobilized on the surface of the substrate without impairing the photocatalytic activity, and (2) the film to be formed and the film coated with the film It is required that the substrate has durability that does not deteriorate due to the action of the photocatalyst.

Furthermore, as a preferable condition for expanding the application range of the substrate to be immobilized, (3) the immobilization condition is mild (room temperature to about 150 ° C.), (4) the coating film is excellent in transparency, durability, Forming a film excellent in stain resistance, hardness and the like.
Various methods have been proposed so far for immobilizing a photocatalyst by coating.
For example, in Patent Document 1, after a sol containing a photocatalyst precursor, for example, an organic titanate, is applied to the surface of a base material, the photocatalyst precursor is gelled by calcination and converted into a photocatalyst. A method of immobilizing on the surface of a substrate has been proposed. However, this method includes a step of generating photocatalyst fine-particle crystals on the surface of the substrate, and this step requires firing at a high temperature. Therefore, when the surface area of a base material is large, there exists a fault that fixation of a photocatalyst becomes difficult.

  In Patent Document 2, as a method of using a photocatalyst-containing sol (and thus not requiring a photocatalyst fine-particle crystal formation process), a method of coating the surface of a substrate with a titanium oxide sol peptized in water is proposed. Has been. However, since titanium oxide sol has no film-forming property under mild conditions, this method also requires firing at a high temperature. In addition, the resulting coating is brittle and easily broken, and the photocatalyst falls off from the surface of the substrate, so that the photocatalyst cannot be effective on the surface of the substrate.

  A method of coating the surface of a substrate using a resin paint mixed with a photocatalyst has also been proposed. For example, in Patent Document 3, Patent Document 4 and Patent Document 5, a photocatalyst is mixed with a resin paint containing a resin that is not easily decomposed by the action of a photocatalyst, such as a fluororesin or a silicone resin, as a coating film forming element. A method of using and coating the surface of a substrate has been proposed. However, in these methods, since the dispersibility of the photocatalyst with respect to the resin paint is poor, the resin paint becomes cloudy. In addition, in order to obtain a film showing good physical properties by these methods, it is necessary to increase the amount of the above-mentioned resin. However, in this case, the photocatalyst is buried in the film formed by the coating. Therefore, there is a drawback that it does not show sufficient activity.

Further, when an organic base material such as a plastic molded body, a film, or an organic coating film is used as a base material for immobilizing the photocatalyst, the photocatalytic film obtained by the above-described conventional technology is coated with the organic base material by photocatalytic action. Oxidative decomposition causes interface deterioration between the organic base material and the photocatalytic film, and has a disadvantage that durability over a long period cannot be maintained.
Patent Document 6 proposes a method in which a resin paint and photocatalyst particles adjusted in wettability with respect to a solvent constituting the resin paint are used in combination. That is, a method has been proposed in which a resin paint is first applied to the surface of a substrate, and then photocatalyst particles are applied on the resin paint before the resin paint is cured. However, this method has a drawback that the process is complicated and a uniform and transparent coating film cannot be obtained. In this patent publication, for the purpose of simplifying the process, a method of coating by applying a mixture of photocatalyst particles adjusted in wettability to a solvent in a resin paint is also proposed. However, just adjusting the wettability to the solvent cannot prevent the photocatalyst particles from being embedded in the film formed by the coating, and most of the photocatalyst particles are completely embedded in the film. There is no effect of preventing deterioration of the organic base material due to the photocatalytic action.

  As a method for overcoming the various disadvantages of the prior art described above, we have developed a photocatalyst composition comprising a modified photocatalyst whose surface is modified with a silicone compound having a low surface energy and a binder having a higher surface energy. Proposed as Patent Document 7. The photocatalytic composition forms a film (self-graded film) that is anisotropically distributed in the surface direction such that the concentration of the photocatalyst particles is small near the interface in contact with the organic substrate and is largely distributed near the film surface. The photocatalytic film having a large photocatalytic activity having excellent weather resistance and no interfacial deterioration due to the organic substrate is formed. However, in applications where very high transparency is required, further improvement in transparency has been desired in a state where both high weather resistance and photocatalytic activity are achieved.

JP 60-118236 A JP-A-6-278241 JP-A-7-171408 Japanese Patent Application Laid-Open No. 9-100347 JP-A-11-188271 JP-A-9-314052 International Publication No. 00/30747 Pamphlet

  The problem of the present invention is that there is no deterioration of the interface between the photocatalyst body having high transparency and the organic base material and the deterioration of the binder in the photocatalyst film, and the surface has a photocatalytic activity and a long period by light irradiation. In other words, a functional composite that exhibits hydrophilicity and maintains high transparency and excellent durability is obtained with good reproducibility without requiring a complicated process.

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 is as follows.
1. A photocatalyst comprising a photocatalyst particle (a), a binder component (B) and an ultraviolet absorber (U), wherein the mass ratio (a) / (B) of the photocatalyst particle (a) to the binder component (B) is 0. 0.01 / 99.99 to 5/95, the total light transmittance is 95% or more, and the photocatalytic activity and / or hydrophilicity is obtained by irradiating light with energy higher than the band gap energy of the photocatalyst particles (a). A photocatalyst that exhibits properties.
2. 1. A light stabilizer (H) is further included. A photocatalyst described in 1.
3. 1. The surface energy of the photocatalyst particles (a) is smaller than that of the binder component (B). Or 2. A photocatalyst described in 1.

4). The binder component (B) is a phenyl group-containing silicone (BP) represented by the formula (1). Or 2. A photocatalyst described in 1.
R ¹ _p R ² _q X _r SiO _{(4-PQR) / 2} (1)
(In the formula, each R ¹ represents a phenyl group, and each R ^{2 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 group. Represents an alkenyl group having 2 to 30 carbon atoms, each X independently represents a hydrogen atom, a hydroxyl group, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, an aminoxy group, or 1 to 20 carbon atoms. And p, q, and r are 0 <p <4, 0 ≦ q <4, 0 ≦ r <4, and 0 <(p + q + r) <4, and 0.05 ≦ p / (p + q) ≦ 1)

5. 1. The photocatalyst particle (a) is a visible light responsive photocatalyst. Or 2. A photocatalyst described in 1.
6). Above 1. Or 2. A photocatalyst composition described in the above, is formed.
7). Above 1. Or 2. A functional composite, wherein the photocatalyst described in 1 is formed as a film on a substrate, and the film thickness thereof is 0.1 to 100 μm.
8). The photocatalyst having anisotropy with respect to the distribution of the photocatalyst particles (a), and the concentration of the photocatalyst particles (a) is higher on the surface than on the surface of the photocatalyst in contact with the substrate. . The functional complex described in 1.
9. 6. The photocatalyst particles (a) form a layer having a thickness of 0.1 μm or less on the coating surface. Or 8. The functional complex described in 1.
10. 6. The photocatalyst particles (a) are not present on the surface in contact with the substrate. ~ 9. The functional complex in any one of.

  The photocatalyst of the present invention is excellent in durability that the surface exhibits photocatalytic activity and / or hydrophilicity over a long period of time by light irradiation and maintains high transparency.

Hereinafter, the present invention will be described in detail.
The photocatalyst of the present invention comprises photocatalyst particles (a), a binder component (B) and an ultraviolet absorber (U), and the mass ratio (a) / (B) of the photocatalyst particles (a) to the binder component (B). Is 0.01 / 99.99 to 5/95.
From the viewpoint of transparency, the mass ratio (a) / (B) of the photocatalyst particles (a) to the binder component (B) is preferably 5/95 or less, from the viewpoint of the expression of photocatalytic activity and / or hydrophilicity. The mass ratio (a) / (B) of the photocatalyst particles (a) is preferably 0.01 / 99.99 or more, and more preferably, the mass ratio (a) / (B) is 0.1 / 99.9. To 5/95, and more preferably the mass ratio (a) / (B) is in the range of 0.3 / 99.7 to 5/95.

The total light transmittance of the photocatalyst of the present invention is 95% or more. For example, when used for applications that require particularly high transparency such as window films, a total light transmittance of 98% or more is preferable. Preferably it is 99% or more.
In the present invention, the photocatalytic activity means that an oxidation or reduction reaction is caused by light irradiation. These photocatalytic activities can be determined, for example, by measuring the decomposability of organic substances such as pigments when the material surface is irradiated with light. A surface having photocatalytic activity exhibits excellent decomposition activity and contamination resistance of contaminating organic substances.

  In the present invention, the term “hydrophilic” refers to a case where the water contact angle at 20 ° C. is preferably 60 ° or less. It is preferable because it exhibits stain resistance due to its self-purifying ability (self-cleaning). Further, from the viewpoint of excellent stain resistance and antifogging properties, the contact angle of water on the surface is preferably 10 ° or less, and more preferably 5 ° or less.

The photocatalyst of the present invention is preferably a photocatalyst composition (C) containing photocatalyst particles (a) and a binder component (B) or a precursor (B ′) of the binder component (B) and an ultraviolet absorber (U). Can be formed.
Here, the precursor (B ′) of the binder component (B) reacts by drying, heating, moisture absorption, light irradiation, etc. to form the binder component (B) contained in the photocatalyst of the present invention. Say.

In the present invention, the surface energy of the binder component (B) and / or its precursor (B ′) is preferably larger than that of the photocatalyst particles (a), and the relative difference in surface energy is 2 mN / m or more. preferable. The greater the relative difference in surface energy, the greater the self-tilting property of the distribution of the photocatalyst particles (a).
Here, the self-gradient is a structure in which the photocatalyst particles (a) have a concentration gradient of the photocatalyst particles (a) corresponding to the properties (interface energy, etc.) of the interface with which the photocatalyst body contacts in the process of forming the photocatalyst body. This means that the photocatalyst is formed so as to be in contact with air, and the photocatalyst particles (a) are present in a large proportion on the surface of the photocatalyst that is in contact with air.

In addition, since the photocatalytic activity and / or hydrophilicity is expressed on the surface of the photocatalyst, it is preferable that the photocatalyst particles (a) are present on the surface of the film in view of the utilization efficiency of the photocatalyst particles (a). More preferably.
It is preferable that the photocatalyst particles (a) do not exist on the surface in contact with the base material because the base material is not violated even when the photocatalytic activity is exhibited.

Examples of the photocatalyst particles (a) that can be used in the present invention include, for 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 , Ta ₃ N ₅ etc., and further, Ti, Nb, Ta, Layered oxides having at least one element selected from V (for example, JP-A-62-274452, JP-A-2-172535, JP-A-7-24329, JP-A-8-89799) JP-A-8-89800, JP-A-8-89804, JP-A-8-198061, JP-A-9-248465, JP-A-10-99694, JP-A-10-244165, etc. ).

Among these photocatalyst particles (a), TiO ₂ (titanium oxide) is preferable because it is harmless and has excellent chemical stability. Any of anatase, rutile, and brookite can be used as titanium oxide.
Further, when a visible light responsive photocatalyst capable of expressing photocatalytic activity and / or hydrophilicity by irradiation with visible light (for example, a wavelength of about 400 to 800 nm) is selected as the photocatalytic particle (a) used in the present invention, The photocatalyst formed from the photocatalyst composition of the present invention is preferable because it can sufficiently exhibit antibacterial and antifouling effects, etc. even in places where ultraviolet rays such as indoors are not sufficiently irradiated.

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 Oxynitride compounds (for example, see JP-A-2002-66333), oxysulfide compounds such as Sm ₂ Ti ₂ S ₂ O ₇ (for example, see JP-A-2002-233770), and nitriding such as Ta ₃ N ₅ Compounds, oxides containing metal ions in the d10 electronic state such as CaIn ₂ O ₄ , SrIn ₂ O ₄ , ZnGa ₂ O ₄ , Na ₂ Sb ₂ O ₆ (see, for example, JP-A-2002-59008), ammonia and urea In the presence of nitrogen-containing compounds such as titanium oxide precursors (titanium oxysulfate, titanium chloride, alkoxy titanium, etc.) and high surface titanium oxide Nitrogen-doped titanium oxide (see, for example, JP-A-2002-29750, JP-A-2002-87818, JP-A-2002-154823, JP-A-2001-207082), thiourea, etc. Sulfur-doped titanium oxide and titanium oxide obtained by firing a titanium oxide precursor (titanium oxysulfate, titanium chloride, alkoxytitanium, etc.) in the presence of a sulfur compound may be subjected to hydrogen plasma treatment or heat treatment under vacuum. The oxygen-deficient titanium oxide obtained by the above (for example, see JP-A-2001-98219), further, the photocatalyst particles are treated with a halogenated platinum compound (for example, see JP-A-2002-239353), or treated with tungsten alkoxide. (See JP 2001-286755 A) It can be given a surface treatment photocatalyst etc. suitably.
Among the visible light responsive photocatalysts, oxynitride compounds, oxysulfide compounds, and nitride compounds have a large photocatalytic activity by visible light, and can be particularly preferably used.

Furthermore, the above-mentioned photocatalyst particles (a) are preferably added or fixed with metals such as Pt, Rh, Ru, Nb, Cu, Sn, Ni, Fe and / or their oxides, or with porous calcium phosphate or the like. It can also be used as a photocatalyst (see, for example, JP-A-10-244166).
As the form of the photocatalyst particles (a), any of powder, dispersion, and sol can be used. In the modification treatment with the modifier compound (b) in the present invention, it is preferable to use a photocatalyst sol or a photocatalyst dispersion for reasons such as efficiency and uniformity. Here, the photocatalyst sol and the photocatalyst dispersion used in the present invention are 0.01 to 80% by mass, preferably 0.1 to 50% by mass of primary particles and / or photocatalyst particles in water and / or an organic solvent. Dispersed as secondary particles.

  As the photocatalyst sol and the photocatalyst dispersion liquid, the photocatalyst particles having a number average dispersed particle size of 400 nm or less of a mixture of primary particles and secondary particles (which may be either primary particles or secondary particles) are modified. This is desirable because the surface characteristics of the photocatalyst can be used effectively. In particular, when photocatalyst particles having a number average dispersed particle size of 100 nm or less are used, a film having excellent transparency can be obtained from the photocatalyst composition of the present invention, which is very preferable. More preferably, a photocatalyst sol and a photocatalyst dispersion liquid of 80 nm or less and 3 nm or more, and more preferably 50 nm or less and 3 nm or more are suitably selected.

  Here, examples of the organic solvent used in the photocatalyst sol or the photocatalyst dispersion include, for example, alcohols such as ethylene glycol, butyl cellosolve, n-propanol, isopropanol, n-butanol, ethanol, methanol, toluene, xylene, and the like. Aromatic hydrocarbons, aliphatic hydrocarbons such as hexane, cyclohexane and heptane, esters such as ethyl acetate and n-butyl acetate, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, tetrahydrofuran, dioxane and the like Ethers, amides such as dimethylacetamide, dimethylformamide, halogen compounds such as chloroform, methylene chloride, carbon tetrachloride, dimethyl sulfoxide, nitrobenzene, etc., and a mixture of two or more of these And the like.

Taking a titanium oxide sol as an example of the photocatalyst sol, for example, a titanium oxide hydrosol in which water is substantially used as a dispersion medium and titanium oxide particles are peptized therein can be exemplified. Here, substantially using water as a dispersion medium means that about 80% by mass or more of water is contained in the dispersion medium. Such sol adjustment is known and can be easily produced (see, for example, 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. Furthermore, 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, for example, by the method proposed in JP-A-10-67516. Can do.
The titanium oxide hydrosol described above is also commercially available as a titania sol. (For example, “STS-02” manufactured by Ishihara Sangyo Co., Ltd .: trade name, “TO-240” manufactured by Tanaka Transcript Co., Ltd .: trade name, etc.)

  Further, for example, a cerium oxide sol (for example, see JP-A-8-59235) or a layered oxide sol having at least one element selected from the group consisting of Ti, Nb, Ta, and V (for example, JP-A-9-9 No. 25123, JP-A-9-67124, JP-A-9-227122, JP-A-9-227123, JP-A-10-259023, etc.) and other methods for producing photocatalyst sols are also oxidized. It is known as well as titanium sol.

Furthermore, a visible light responsive photocatalyst sol that can be suitably used in the present invention is also commercially available. (For example, “NTB-200” manufactured by Showa Denko KK, “TSS” manufactured by Sumitomo Chemical Co., Ltd., etc.)
In addition, a photocatalyst organosol in which an organic solvent is substantially used as a dispersion medium and in which photocatalyst particles are dispersed is a compound having a phase transfer activity such as polyethylene glycol (for example, different first phase and second phase). A third phase is formed at the interface with the phase, the first phase, the second phase, the third phase are mutually dissolved and / or solubilized compounds) and diluted with an organic solvent (for example, JP-A-10-167727), a method of preparing a sol by dispersing and dispersing in an organic solvent insoluble in water with an anionic surfactant such as sodium dodecylbenzenesulfonate (for example, JP-A-58-29863) After adding an alcohol having a boiling point higher than that of water such as butyl cellosolve to the photocatalyst hydrosol, it can be obtained by a method of removing water by distillation under reduced pressure. Further, a titanium oxide organosol in which an organic solvent is substantially used as a dispersion medium and in which titanium oxide particles are dispersed is commercially available (for example, “TKS-251” manufactured by TEIKA CORPORATION). Here, the phrase “substantially using an organic solvent as a dispersion medium” means that the dispersion medium contains about 80% by mass or more of the organic solvent.
The photocatalyst dispersion liquid is obtained by dispersing the above-mentioned photocatalyst particle (a) powder in water and / or an organic solvent under a strong shearing force, if necessary, by adding a dispersion stabilizer. be able to.

The photocatalyst particles (a) of the present invention can be modified using at least one modifier compound (b) described below. Since the surface energy of the photocatalyst particles (a) can be reduced by performing the modification treatment, the difference in surface energy from the binder component (B) and / or its precursor (B ′) can be increased. This is possible and preferable.
In the present invention, modification means that at least one modifier compound (b) described later is immobilized on the surface of the photocatalyst particles (a). The above-mentioned immobilization of the modifier compound on the surface of the photocatalyst particles is considered to be due to physical adsorption by van der Waals force or chemical bonding. In particular, modification using a chemical bond is preferable because the interaction between the modifier compound and the photocatalyst is strong, and the modifier compound is firmly immobilized on the surface of the photocatalyst particles.

In the present invention, as the modifier compound (b) used for modifying the photocatalyst particles (a), a triorganosilane unit represented by the following formula (2), a mono compound represented by the following formula (3): It consists of compounds having at least one structural unit selected from the group consisting of an oxydiorganosilane unit, a dioxyorganosilane unit represented by the following formula (4), and a methylene fluoride (—CF ₂ —) unit. It is more preferable in terms of surface energy reduction that it is selected from the group.
R ₃ Si- (2)
(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 fluoroalkyl group having 1 to 30 carbon atoms. A 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) - (} 3)
(In the formula, R is as defined in formula (2).)

（式中、Ｒは式（２）で定義した通りである。）

(In the formula, R is as defined in formula (2).)

In the present invention, the modification treatment of the photocatalyst particles (a) with the modifier compound (b) is performed in the presence or absence of water and / or an organic solvent in the same manner as the above-described photocatalyst particles (a). (B) is preferably a mass ratio (a) / (b) = 1/99 to 99.99 /
0.01, more preferably (a) / (b) = 10/90 to 99.5 / 0.5, preferably 0 to 200 ° C., more preferably 10 to 80 ° C. Or by changing the solvent composition of the mixture by distillation (reduced pressure) or the like.

  Here, when performing the above modification treatment, examples of the organic solvent that can be used include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, cyclohexane, and heptane, ethyl acetate, and n-butyl acetate. Esters such as ethylene glycol, butyl cellosolve, alcohols such as isopropanol, n-butanol, ethanol and methanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ethers such as tetrahydrofuran and dioxane, dimethylacetamide, dimethyl Examples include amides such as formamide, halogen compounds such as chloroform, methylene chloride, and carbon tetrachloride, dimethyl sulfoxide, nitrobenzene, and mixtures of two or more thereof.

  Examples of the modifier compound (b) suitably used for modifying the photocatalyst particles (a) of the present invention include, for example, Si—H groups, hydrolyzable silyl groups (alkoxysilyl groups, hydroxysilyl groups, Halogenated silyl group, acetoxysilyl group, aminoxysilyl group, etc.), epoxy group, acetoacetyl group, thiol group, acid anhydride group and other photocatalyst particles (a) reactive with silicon compounds, fluoroalkyl compounds, A fluoroolefin polymer etc. can be mentioned. These compounds are more preferable because they can chemically bond to the photocatalyst particles (a) and are firmly fixed on the surface of the photocatalyst particles (a).

  Among the above modifiers, for example, compounds having Si-H groups are exemplified: bis (trimethylsiloxy) methylsilane, bis (trimethylsiloxy) ethylsilane, bis (trimethylsiloxy) n-propylsilane, bis (trimethylsiloxy) i-propyl. Silane, bis (trimethylsiloxy) n-butylsilane, bis (trimethylsiloxy) n-hexylsilane, bis (trimethylsiloxy) cyclohexylsilane, bis (trimethylsiloxy) phenylsilane, bis (triethylsiloxy) methylsilane, bis (triethylsiloxy) ethylsilane , Tris (trimethylsiloxy) silane, tris (triethylsiloxy) silane, pentamethyldisiloxane, 1,1,1,3,3,5,5-heptamethyltrisiloxane, 1,1,1,3,3 , 5,6,6-nonamethyltetrasiloxane, trimethylsilane, ethyldimethylsilane, methyldiethylsilane, triethylsilane, phenyldimethylsilane, diphenylmethylsilane, cyclohexyldimethylsilane, t-butyldimethylsilane, di-t-butylmethyl Silane, n-octadecyldimethylsilane, tri-n-propylsilane, tri-i-propylsilane, tri-i-butylsilane, tri-n-hexylsilane, triphenylsilane, allyldimethylsilane, 1-allyl-1,1 , 3,3-tetramethyldisiloxane, chloromethyldimethylsilane, 7-octenyldimethylsilane and the like.

  Examples of the modifier compound (b) used in the present invention include Si-H groups, hydrolyzable silyl groups (alkoxysilyl groups, hydroxysilyl groups, halogenated silyl groups, acetoxysilyl groups, and aminoxysilyl groups. Reactive groups that can be expected to form chemical bonds with photocatalyst particles such as epoxy groups, acetoacetyl groups, thiol groups, and acid anhydride groups, polyoxyalkylene groups, sulfonic acid groups, carboxyl groups, phosphoric acid groups, etc. Modification obtained by using a fluorine-based compound such as a fluoroalkyl compound having 1 to 30 carbon atoms having a hydrophilic group that can be expected to have an affinity for photocatalyst particles or a fluoroalkylene compound having a number average molecular weight of 100 to 1,000,000 The surface energy of the photocatalyst (a) becomes very small, and the photocatalyst composition of the present invention has a large photocatalytic activity, antibacterial properties, Preferable since it is possible to obtain an excellent photocatalyst sexual like.

Examples of the fluorine compound include a fluoroalkyl compound represented by the formula (5) and a fluoroolefin polymer represented by the formula (7).
_{CF 3 (CF 2) g -Y-} (V) w (5)
[In formula, g represents the integer of 0-29. Y represents a w-valent organic group having a molecular weight of 14 to 50,000. w is an integer of 1-20. V is composed of an epoxy group, a hydroxyl group, an acetoacetyl group, a thiol group, a cyclic acid anhydride group, a carboxyl group, a sulfonic acid group, a polyoxyalkylene group, a phosphoric acid group, and a group represented by the following formula (6). It represents at least one functional group selected from the group.
-SiW _x R _y (6)
(In the formula, W represents an alkoxy group having 1 to 20 carbon atoms, a hydroxyl group, an acetoxy group having 1 to 20 carbon atoms, a halogen atom, a hydrogen atom, an oxime group having 1 to 20 carbon atoms, an enoxy group, an aminoxy group, and an amide group. Represents at least one selected group, and R represents a linear or branched alkyl group having 1 to 30 carbon atoms, a cycloalkyl group having 5 to 20 carbon atoms, and an unsubstituted or substituted one. Represents at least one hydrocarbon group selected from an alkyl group of -20, an alkoxy group of 1-20 carbon atoms, or an aryl group of 6-20 carbon atoms substituted with a halogen atom, and x is 1 or more and 3 or less. It is an integer, y is an integer of 0 or more and 2 or less, and x + y = 3.]]

（式中、Ａ¹ 〜Ａ⁵ は同一でも異なっていても良く、それぞれフッ素原子、水素原子、塩素原子、炭素数１〜６のアルキル基、及び炭素数１〜６のハロ置換アルキル基から選ばれる１種を示す。Ｙは分子量１４〜５００００のｗ価の有機基（当該有機基Ｙの主鎖との結合以外にｗ価である基、好ましくはフッ化メチレン単位を有する基、より好ましくはパーフルオロアルキル基を有する基）を表す。Ｖは、エポキシ基、水酸基、アセトアセチル基、チオール基、環状酸無水物基、カルボキシル基、スルホン酸基、ポリオキシアルキレン基、加水分解性シリル基からなる群から選ばれた少なくとも１つの官能基を表す。ｋは０以上１００００００以下の整数であり、ｌは１以上１０００００以下の整数を表す。ただし、ｋ＝０の時は、好ましくはＡ³ 〜Ａ⁵ の少なくとも１つがフッ素原子、より好ましくはＡ³ 、Ａ⁴ が共にフッ素原子を表す。ｗは１〜２０の整数である。）

(In the formula, A ^{1 to} A ⁵ may be the same or different and are each selected from a fluorine atom, a hydrogen atom, a chlorine atom, an alkyl group having 1 to 6 carbon atoms, and a halo-substituted alkyl group having 1 to 6 carbon atoms. Y is a w-valent organic group having a molecular weight of 14 to 50000 (a group having a w-value other than the bond to the main chain of the organic group Y, preferably a group having a methylene fluoride unit, more preferably V represents an epoxy group, a hydroxyl group, an acetoacetyl group, a thiol group, a cyclic acid anhydride group, a carboxyl group, a sulfonic acid group, a polyoxyalkylene group, or a hydrolyzable silyl group. Represents at least one functional group selected from the group consisting of: k is an integer of 0 or more and 1000000 or less, and l is an integer of 1 or more and 100000 or less, provided that k = 0 is preferable. At least one fluorine atom in A ³ to A ^5, more preferably .w representing the A ^3, A ⁴ are both fluorine atoms is an integer of from 1 to 20.)

Specific examples of the fluorine-based compound include, for example, 2-perfluorooctylethyltrimethoxysilane, 2-perfluorooctylethyltriethoxysilane, 2-perfluorooctylethylmethyldimethoxysilane, and trifluoromethylethyltrimethoxy. Fluoroalkylsilanes such as silane and trifluoromethylethyltriethoxysilane, Nafion resin, fluoroolefins such as chlorotrifluoroethylene and tetrafluoroethylene, and epoxy groups, hydroxyl groups, carboxyl groups, acetoacetyl groups, thiol groups, cyclic acids Examples thereof include copolymers with monomers having an anhydride group, sulfonic acid group, polyoxyalkylene group and the like (vinyl ether, vinyl ester, allyl compound, etc.).
In the present invention, as the modifier compound (b) used for modifying the photocatalyst particles (a), the affinity between the long-chain alkyl group having 10 to 100 carbon atoms and the reactive group and / or the photocatalyst particles is used. It is also possible to use a compound (b3) having a hydrophilic group that can be expected to have good properties.
Examples of the long-chain alkyl group-containing compound (b3) include nonionic surfactants such as alkyl polyoxyethylene ether, alkyl polyoxyethylene ether phosphate, alkyl polyoxyethylene ether sulfate, and alkyl polyoxyethylene phosphoric acid. Examples thereof include anionic surfactants such as esters, alkyl polyoxyethylene sulfates, alkyl sulfates, alkylbenzene sulfonates, and alkylbenzene sulfonic acids.

Specific examples of these include sodium lauryl polyoxyethylene ether phosphate, sodium lauryl polyoxyethylene ether sulfate, lauryl polyoxyethylene phosphate ester, lauryl polyoxyethylene sulfate ester, sodium dodecylbenzenesulfonate, sodium laurylbenzenesulfonate, Examples include sodium dodecyl sulfate, sodium lauryl sulfate, dodecyl benzene sulfonic acid, and lauryl benzene sulfonic acid.
These compounds can be used alone or in combination of two or more.

  In a preferred embodiment of the photocatalyst particles (a) modified with the modifier compound (b) in the present invention, the number average dispersed particle size of the mixture of primary particles and secondary particles of the modified photocatalyst is 800 nm or less, more preferably 1 nm. It is not less than 400 nm, particularly preferably not less than 5 nm and not more than 100 nm. A sol or dispersion state is preferred. The state of the sol or dispersion can be suitably obtained by using the above-mentioned photocatalyst sol or photocatalyst dispersion as the photocatalyst particles (a) to be modified with the modifier compound (b). Further, when the photocatalyst powder is modified with the modifier compound (b), it is preferably dispersed in a solvent by a bead mill, a ball mill or the like after the modification treatment.

  In the present invention, examples of components that can be used for the binder component (B) and its precursor (B ′) include various monomers, synthetic resins, natural resins, and the like. The thing hardened | cured by heating, moisture absorption, light irradiation, etc. can also be mentioned. Further, the form thereof may be in a solvent-free state (pellet, powder, liquid, etc.) or may be dissolved or dispersed in a solvent, and is not particularly limited.

As the synthetic resin, any thermoplastic resin and curable resin (thermosetting resin, photocurable resin, moisture curable resin, etc.) can be used. For example, acrylic resin, methacrylic resin, 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, polyphenylene sulfone resin , Polyether resin, polyvinyl chloride resin, polyvinylidene chloride resin, urea resin, phenol resin, melamine resin, epoxy resin, urethane resin, silicone-acrylic resin, silicone resin, fluorine resin, and water glass Zirconium compounds include inorganic compounds such as titanium peroxide.
Examples of the natural polymer include cellulose resins such as nitrocellulose, isoprene resins such as natural rubber, protein resins such as casein, and starch.

In the present invention, the surface energy and the relative difference between the surface energies are referred to, for example, Polymer Handbook (published by A Wiley-interscience publication in the United States), the wetting tension test of Japanese standard (JIS-K-6768), Can be preferably determined by measuring by the following method or the like.
For example, a base material having a coating of the binder component (B) or its precursor (B ′) is prepared, deionized water is added dropwise to measure a contact angle (θ) at 20 ° C., and the following Cell and Neumann's The surface energy can also be obtained by an empirical formula.

［式中、γｓは脱イオン水の接触角を測定した表層部の表面エネルギー（ｍＮ／ｍ）を表し、γｌは水の表面エネルギー｛７２．８ｍＮ／ｍ（２０℃）｝を表わす。］

[Wherein γs represents the surface energy (mN / m) of the surface layer portion where the contact angle of deionized water was measured, and γl represents the surface energy of water {72.8 mN / m (20 ° C.)}. ]

As the binder component (B) and its precursor (B ′) used in the photocatalyst composition of the present invention, the surface energy is preferably 2 mN / m or more, more preferably 5 mN / m or more than the above-described modified photocatalyst (a). Further, it is very preferable to select a material having a larger value of 10 mN / m or more because the self-tilt property is increased.
Examples of the binder component (B) having a relatively large surface energy and the precursor (B ′) that can be used in the photocatalyst of the present invention include a phenyl group-containing silicone (BP) represented by the following formula (1): However, since the siloxane bond (—O—Si—) constituting the skeleton is not oxidatively decomposed by photocatalysis, it can be most preferably used.
^{_{R 1 p R 2 q X r}} SiO (4-pqr) / 2 (1)
(In the formula, each R ¹ represents a phenyl group, and each R ² 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 Represents a branched alkenyl group having 2 to 30 carbon atoms, each X independently represents a hydrogen atom, a hydroxyl group, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, an aminoxy group, 1 to 1 carbon atom; 20 represents an oxime group, a halogen atom, and p, q, r and s are 0 <p <4, 0 ≦ q <4, 0 ≦ r <4 and 0 <(p + q + r) <4, and 0 .05 ≦ p / (p + q) ≦ 1.)

Moreover, as said phenyl group containing silicone (BP), the phenyl group containing silicone (BP1) which does not contain the alkyl group represented by following formula (8) becomes higher in surface energy, and is preferable.
R ¹ _t X _u SiO _{(4-tu) / 2} (8)
(In the formula, R ¹ represents a phenyl group, and each X independently represents a hydrogen atom, a hydroxyl group, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, an aminoxy group, or an oxime having 1 to 20 carbon atoms. A group, a halogen atom, and t and u are 0 <t <4, 0 ≦ u <4, and 0 <(t + u) <4.)

  Among the phenyl group-containing silicones (BP1) represented by the above formula (8), the most preferable one in terms of reactivity (good crosslinkability) is the number average obtained by polycondensation of phenyltrialkoxysilane and / or phenyltrichlorosilane. It is a phenyl group-containing silicone having a number average molecular weight of 400 to 1,000,000 obtained by reacting an oligomer having a molecular weight of 300 to 5000 with a polycondensation of tetraalkoxysilane and / or tetraalkoxysilane and having a number average molecular weight of 100 to 3000.

In the present invention, a silicone resin such as the above-mentioned phenyl group-containing silicone (BP) is contained as the binder component (B) or its precursor (B ′), and the silicone resin is a hydroxysilyl group and / or a hydrolyzate. When it has a decomposable silyl group, a conventionally known hydrolysis catalyst or curing catalyst is preferably added in an amount of 0.01 to 30% by mass, more preferably 0.1 to 15% by mass with respect to the silicone resin. be able to.
As the hydrolysis catalyst, acidic hydrogen halides, carboxylic acids, sulfonic acids, acidic or weakly acidic inorganic salts, solid acids such as ion exchange resins, and the like are preferable. The amount of the hydrolysis catalyst is preferably in the range of 0.001 to 5 mol with respect to 1 mol of the hydrolyzable group on the silicon atom.

  Examples of the curing catalyst include basic compounds such as sodium hydroxide, potassium hydroxide, sodium methylate, sodium acetate, tetramethylammonium chloride, tetramethylammonium hydroxide; tributylamine, diazabicycloundecene, Amine compounds such as ethylenediamine, diethylenetriamine, ethanolamines, γ-aminopropyltrimethoxysilane, γ- (2-aminoethyl) -aminopropyltrimethoxysilane; titanium compounds such as tetraisopropyl titanate and tetrabutyl titanate; aluminum Such as triisopropoxide, aluminum-triacetylacetonate, tris- (ethylacetoacetonato) aluminum, aluminum perchlorate, aluminum chloride Aluminum compounds; tin compounds such as tin acetylacetonate, dibutyltin octylate, dibutyltin dilaurate; zirconium-tetraacetylacetonate, tetra- (ethylacetoacetonato) zirconium, zirconium-tributoxy-acetylacetonate, zirconium-dibutoxy- Zirconium compounds such as diacetylacetonate, zirconium-dichloro-diacetylacetonate, tetrabutylzirconate; metal-containing compounds such as cobalt octylate, cobalt acetylacetonate, iron acetylacetonate; phosphoric acid, nitric acid, phthalic acid, Examples thereof include acidic compounds such as p-toluenesulfonic acid and trichloroacetic acid.

In the present invention, it is preferable to use a metal compound among the above curing catalysts because the effect as a reactive improver of a reactive group is exhibited as described above. Of these, the use of a zirconium compound, preferably zirconium-tetraacetylacetonate, is preferable because the hardness, chemical resistance, boiling water resistance, weather resistance and the like of the photocatalyst formed therefrom are further improved.
Moreover, as a binder component (B) and its precursor (B ') in this invention, a hydroxyl group and / or a C1-C20 alkoxy group, an enoxy group, a C1-C20 acyloxy group, an aminoxy group, carbon An acrylic polymer having a silyl group having a silicon atom bonded to at least one hydrolyzable group selected from the group consisting of an oxime group of 1 to 20 and a halogen atom at the terminal and / or side chain of the polymer molecular chain Since the surface energy is relatively high and the weather resistance is excellent, it can be preferably used.

  In the present invention, a binder component (F) selected from a silicone resin and a fluororesin having a surface energy smaller than that of the binder component (B) and its precursor (B ′) is a mass ratio (F) / (B) = 0.01 / 99.9 to 95/5, preferably (F) / (B) = 0.01 / 99.9 to 50/50, more preferably (F) / (B) = 0.01 / 99 In the range of .9 to 10/90, since the binder component (F) has an action of promoting the self-tilting function of the photocatalyst particles (a), an excellent self-tilting photocatalyst is obtained, which is very preferable. .

In the photocatalyst of the present invention, examples of the fluorine-based resin that can be suitably used as the binder component (F) include 2-perfluorooctylethyltrimethoxysilane, 2-perfluorooctylethyltriethoxysilane, and 2-perfluorooctyl. Fluoroalkylsilanes such as ethylmethyldimethoxysilane, trifluoromethylethyltrimethoxysilane, and trifluoromethylethyltriethoxysilane and their polycondensates, PTFE and polyvinylidene fluoride, Nafion resin, chlorotrifluoroethylene and tetrafluoro Examples thereof include copolymers of fluoroolefins such as ethylene and monomers (vinyl ether, vinyl ester, allyl compound, etc.). These fluororesins can be used alone or in combination of two or more.

  In the photocatalyst of the present invention, examples of the silicone resin that can be suitably used as the binder component (F) include dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, alkoxy group-containing silicone oil, and silanol group. -Containing silicone oil, vinyl group-containing silicone oil, silicone oils such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, polyether-modified silicone, polyglycerin-modified silicone, amino-modified silicone, epoxy-modified silicone, mercapto-modified silicone, methacryl Modified silicone, carboxylic acid modified silicone, fatty acid ester modified silicone, alcohol modified silicone, alkyl modified silicone, fluoroalkyl modified Modified silicones such as silicone, monomers, oligomers and polymers of (alkyl) alkoxysilane such as tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, γ-aminopropyltri Examples include silane coupling agents such as methoxysilane, reaction products thereof, and silicone surfactants. These silicones can be used alone or in combination of two or more.

  In the present invention, when the above-described phenyl group-containing silicone (BP) is used as the binder component (B) or its precursor (B ′), when phenylmethylpolysiloxane is used as the binder component (F), film forming properties are obtained. It is preferable because it is excellent in terms of hardness, heat resistance, contamination resistance, chemical resistance, and the like.

  The photocatalyst of the present invention is characterized by containing an ultraviolet absorber (U) in addition to the photocatalyst particles (a) and the binder component (B) described above. By containing the ultraviolet absorber (U), the photocatalyst of the present invention is extremely excellent in light resistance, weather resistance and the like. In addition, the functional composite of the present invention in which the photocatalyst is formed as a film on the substrate is also very light and weather resistant due to the effect of the ultraviolet absorber (U) contained in the photocatalyst. It will be excellent.

The effect of improving the weather resistance by the ultraviolet absorber (U) in the present invention is a structure that exhibits photocatalytic activity and / or hydrophilicity with a very small photocatalyst content in the photocatalyst of the present invention, that is, photocatalyst particles (a). Is effectively expressed by the structure present in a large proportion on the surface of the photocatalyst body in contact with air. That is, in a photocatalyst body with a high photocatalyst content, the ultraviolet absorber (U) itself is decomposed by the photocatalytic action, so that the effect of improving weather resistance cannot be effectively exhibited.
The content of the ultraviolet absorber (U) in the photocatalyst 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. 0.001 to 10% by mass, preferably 0.01 to 5% by mass.

Preferred examples of the ultraviolet absorber (U) that can be used in the present invention include benzophenone-based, benzotriazole-based, and triazine-based ultraviolet absorbers.
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'-carboki Benzophenone, 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-4- Examples thereof include polymerizable benzophenone ultraviolet absorbers such as (acryloxy-triethoxy) benzophenone, and (co) polymers thereof.

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

Specific examples of triazine-based ultraviolet absorbers that can be used in the present invention include TINUVIN-400 (product name, manufactured by Ciba-Geigy Corporation), TINUVIN-411L (product name, manufactured by Ciba-Geigy Corporation), and the like.
Further, in the photocatalyst of the present invention, those further containing a hindered amine-based and / or hindered phenol-based light stabilizer (H) have a synergistic effect with the above-mentioned ultraviolet absorber, so that The composite is preferable because it exhibits excellent weather resistance and light resistance.

The content of the light stabilizer (H) in the photocatalyst 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. It is preferable to contain 0.001-10 mass%, Preferably 0.01-5 mass% is contained.
Specific examples of the hindered amine light stabilizer include bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, bis (2,2,6,6-tetramethylpiperidyl) sebacate, bis (1, 2,2,6,6-pentamethyl-4-piperidyl) 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-butylmalonate, 1- [2- [3- (3 5-Di-tert-butyl-4-hydroxyphenyl) propynyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propynyloxy] -2,2,6 6-tetramethylpiperidine, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and methyl-1,2,2,6,6-pentamethyl-4-piperidyl-sebake Mixture (manufactured by Ciba Geigy Japan, product name: TINUVIN-292), bis (1-octoxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, TINUVIN-123 (product name, Japan) Ciba-Geigy Co., Ltd.), TINUVIN-111FDL (product name, manufactured by Nippon Ciba-Geigy Co., Ltd.), TINUVIN 292 (product name, manufactured by Ciba-Geigy Corp. Japan), and 1,2,2,6,6-pentamethyl-4- Piperidyl methacrylate, 1,2,2,6,6-pentamethyl-4-piperidyl acrylate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 2,2,6,6-tetramethyl-4-piperidyl Acrylate, 1,2,2,6,6-pentamethyl-4-iminopiperidyl methacrylate, 2,2,6 6, -tetramethyl-4-iminopiperidyl methacrylate, 4-cyano-2,2,6,6-tetramethyl-4-piperidyl methacrylate, 4-cyano-1,2,2,6,6-pentamethyl-4- Examples thereof include polymerizable hindered amine ultraviolet absorbers such as piperidyl methacrylate and (co) polymers thereof.

Specific examples of the hindered phenol light stabilizer include bis (3,5-tert-butyl) -4-hydroxytoluene, TINUVIN-144 (product name, manufactured by Ciba Geigy Japan, Inc.), and the like. it can.
The photocatalyst composition for obtaining the photocatalyst of the present invention may be in a solvent-free state (liquid or solid) or dissolved or dispersed in a solvent, and is not particularly limited, but is used as a coating agent. In this case, a dissolved or dispersed state in a solvent is preferable from the viewpoint of viscosity adjustment. At this time, the total amount of the photocatalyst particles (a), the binder component (B), the precursor (B ′) and the ultraviolet absorber (U) in the photocatalyst composition is preferably 0.01 to 95% by mass, more Preferably it is 0.1-70 mass%.

In the photocatalyst composition of the present invention, a compound having a boiling point of 150 ° C. or more and a molecular weight of 1000 or less can be blended.
By blending a compound having a boiling point of 150 ° C. or more and a molecular weight of 1000 or less, the influence of the environment (temperature, humidity, coating conditions, etc.) in the photocatalyst formation process becomes smaller, and the self-tilt related to the above-mentioned photocatalyst particles (a) It becomes possible to further improve the reproducibility of formation of the photocatalyst.
In the photocatalyst composition of the present invention, examples of the compound having a boiling point of 150 ° C. or more and a molecular weight of 1000 or less include various solvents and plasticizers having a boiling point of 150 ° C. or more.

Examples of the solvent include alcohols such as butyl cellosolve, butyl carbitol, propylene glycol, propylene glycol monoethyl ether, propylene glycol monobutyl ether, hydrocarbons such as decane, undecane, dodecane, and sorbesos, and esters such as cellosolve acetate. And ketones such as cyclohexanone, ethers such as diethyl carbitol and dibutyl carbitol, amides such as dimethylacetamide and dimethylformamide, and dimethyl sulfoxide. These solvents are used alone or in combination.

  Examples of the plasticizer include aliphatic dibasic acid esters such as di (2-ethylhexyl) adipate, phosphoric acid triesters such as tri (2-ethylhexyl) phosphate, glycol esters, and dibutyl phthalate. Phthalic acid diesters such as di-n-octyl phthalate and dilauryl phthalate, tetralin paraffin and isoparaffin.

At this time, examples of the viscosity adjusting solvent used in the photocatalyst composition of the present invention include solvents having a boiling point of 150 ° C. or lower in addition to the solvents described above. Examples of these include water, ethylene glycol, isopropanol, n-butanol, ethanol, alcohols such as methanol, aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, cyclohexane, heptane, acetic acid, etc. Examples thereof include esters such as ethyl and n-butyl acetate, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ethers such as tetrahydrofuran and dioxane, and the like. These solvents are used alone or in combination.
In addition, the photocatalyst composition of the present invention usually contains components that are usually added and blended with paints and molding resins as necessary, for example, pigments, curing catalysts, crosslinking agents, fillers, dispersants, wetting agents, thickeners, Rheology control agents, antifoaming agents, plasticizers, film forming aids, rust inhibitors, dyes, preservatives, and the like can be selected, combined, and blended according to their respective purposes.

The photocatalyst of the present invention is preferably in the form of a film or a molded body.
When the photocatalyst in the present invention is formed into a film, the photocatalyst composition is applied to a substrate and dried, and then preferably 20 ° C to 500 ° C, more preferably 40 ° C to 250 ° C, heat treatment or ultraviolet rays. It can be obtained by performing irradiation or the like and forming a film 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 the photocatalyst of the present invention is formed as a film on a substrate, the thickness of the film is preferably 0.1 to 100 μm. The thickness is preferably 100 μm or less from the viewpoint of transparency, and is preferably 0.1 μm or more from the viewpoint of base protection. More preferably, it is 0.5-50 micrometers.
In the present specification, the expression “film” is used. However, the film is not necessarily a continuous film, and may be a discontinuous film, an island-shaped dispersion film, or the like.
The functional composite having the film, which is the photocatalyst of the present invention, on the substrate thus obtained has its surface exhibit photocatalytic activity and / or hydrophilicity, and further exhibits a photoelectric conversion function by light irradiation. Is possible. That is, in another aspect of the present invention, as a photocatalyst formed from the photocatalyst composition, a molded body or a functional composite having a film on a substrate is provided.

The substrate used for obtaining the functional composite of the present invention is not particularly limited, and for example, all substrates used for the applications disclosed in the present invention can be used.
Examples of the base material used to obtain the functional composite of the present invention include organic base materials such as synthetic resins and natural resins, inorganic base materials such as metals, ceramics, glass, stone, cement, and concrete, A combination thereof can be mentioned.
In the functional composite of the present invention, even when an organic base material that is decomposed by a photocatalyst is used, the durability is very excellent. That is, the photocatalyst of the present invention can provide a functional composite having excellent durability even with respect to organic substrates that could not be used conventionally due to durability problems.

The method for producing the functional composite of the present invention is not limited to the case where the photocatalyst of the present invention is formed on a substrate. The base material and the photocatalyst composition of the present invention may be simultaneously molded, for example, integrally molded. Moreover, you may shape | mold a base material after shape | molding the photocatalyst composition of this invention. Moreover, it is good also as a functional composite body by adhesion | attachment, melt | fusion, etc., after shape | molding the photocatalyst composition and base material of this invention separately. When the above method is used for molding in a state where it does not contact the original substrate, another substrate may be used. The substrate in this case is not limited to a solid, and may be a liquid or a gas as long as the effects of the present invention are not impaired.
If necessary, the molded product or functional composite of the present invention can be formed into a film, sheet, block, pellet, or a molded product having a more complicated shape by a method used for resin molding. In molding, it can be used in combination with other resins as long as the effects of the present invention are not impaired.

  The molding method for the present invention can be an extrusion molding method, an injection molding method, a press molding method, or the like. Further, depending on the selection of the resin, such as using a thermoplastic resin in combination, a calendar molding method is also possible. Further, organic fibers including natural fibers, inorganic fibers such as glass (and these woven fabrics), etc. are used as a reinforcing material to impregnate the molded product or functional composite of the present invention and these and other resin mixtures. It is also possible to laminate and form.

  The molded body or functional composite of the present invention may be fibrous. In order to process into a fiber form, a normal spinning method can be used as long as the effects of the present invention are not impaired. As the spinning method, melt spinning and solution spinning are used. In spinning, it can be processed into a fiber by using it together with the other resins described above. For example, an ordinary resin (thermoplastic resin is preferable for molding), for example, polyester, nylon, etc., or the molded product or functional composite of the present invention is blended, or the molded product or functional composite of the present invention These resins may be composite-spun (sheath core, side-by-side type, etc.).

The fibers may be long fibers or short fibers, and may be uniform or thick in the length direction, and the cross-sectional shape is round, triangular, L-shaped, T-shaped, Y-shaped, W-shaped, Yaba It may be a polygonal shape such as a shape, flatness, or dogbone shape, a multi-leaf shape, a hollow shape, or an irregular shape.
The shaped article or functional composite of the present invention in a fibrous form can also be used as a woven fabric or a non-woven fabric (short fiber or long fiber).

Moreover, the form of the fiber which can be used includes a cheese, a woven fabric, a knitted fabric, a non-woven fabric, etc., which are aggregates of yarns and yarns, and may be mixed with fibers of other resins. The forms of the yarn include raw yarn, false twisted yarn (including stretched false twisted yarn), pre-twisted false twisted yarn, air injection processed yarn, ring spun yarn, open-end spun yarn, etc., multifilament raw yarn (extra fine yarn) ), Mixed fiber and the like. The mixed fibers include polyester fibers, polyamide fibers, polyacrylic fibers, polyvinyl fibers, polypropylene fibers, polyurethane fibers, etc. (metal oxides such as magnesium oxide and zinc oxide, metals) Synthetic fibers such as those added with chlorinated water deterioration inhibitors such as hydroxide), natural fibers such as cotton, hemp, wool, and silk, and cellulose fibers and acetate fibers such as cupra, rayon, and polynosic Can be mentioned.
The molded article or functional composite of the present invention processed into the above-described fibrous form can be used for clothing, gas, and liquid filters for the purpose of antibacterial, antifouling, odor prevention, and toxic gas decomposition.

The photocatalyst of the present invention, or the above-mentioned functional complex in which the photocatalyst is immobilized on a substrate, is hydrophobic or hydrophilic by irradiating light with energy higher than the band gap energy of the photocatalyst contained therein. / Or shows photocatalytic activity, and also a photoelectric conversion function.
The photocatalyst particles (a) in the photocatalyst are represented by the triorganosilane unit represented by the formula (1), the monooxydiorganosilane unit represented by the formula (2), and the formula (3). Photocatalyst particles (a) are modified with at least one modifier compound (b) selected from the group consisting of compounds having at least one structural unit selected from the group consisting of dioxyorganosilane units. In some cases, at least a part of the organic group (R) bonded to the silicon atom of the modifier compound (b) present in the vicinity of the photocatalyst particle (a) by excitation light irradiation is substituted with a hydroxyl group by the decomposition action of the photocatalyst. The As a result, the hydrophilicity of the surface of the photocatalyst body of the present invention is enhanced, and when the generated hydroxyl groups are subjected to a dehydration condensation reaction to form a siloxane bond, the hardness of the photocatalyst body becomes very high. Such a state is preferable in the aspect of the present invention.

Similarly, when the above-described silicone-based resin is used as the binder component (B), at least a part of the organic groups bonded to the silicon silicon atoms present in the vicinity of the photocatalyst particles (a) by excitation light irradiation are as follows: When the photocatalyst is substituted with a hydroxyl group by the decomposition action, the hydrophilicity of the surface of the photocatalyst of the present invention is increased, and when the generated hydroxyl group undergoes a dehydration condensation reaction to form a siloxane bond, the hardness of the photocatalyst is very high. To be high. Such a state is preferable in the aspect of the present invention.
In the present invention, as a light source of light having energy higher than the band gap energy of the photocatalyst particles (a), in addition to light obtained in a general residential environment such as sunlight and indoor lighting, black light, xenon lamp, mercury lamp Light such as LED can be used.

The photocatalyst or functional composite of the present invention, which has photocatalytic activity such as organic matter decomposition, exhibits various functions such as antibacterial, antifouling, deodorant, NOx decomposition, and purification of the environment such as air and water It can be used for such applications.
The photocatalyst or functional composite of the present invention, which has a hydrophilic property (hydrophilic film, and the like) having a contact angle with water at 20 ° C. of 60 ° or less (preferably 10 ° or less) by light irradiation. The substrate coated with a hydrophilic film can be applied to anti-fogging technology for preventing fogging of mirrors and glass, and further to antifouling technology and antistatic technology for building exteriors.

  Examples of the application of the photocatalyst or functional composite of the present invention to the antifouling technology field include, for example, building materials, building exteriors, building interiors, window frames, window glass, structural members, building equipment such as houses, particularly toilets, Bathtub, wash basin, lighting fixture, lighting cover, kitchenware, tableware, dishwasher, tableware dryer, sink, cooking range, kitchen hood, ventilation fan, etc. It can be used, and is effective for use in parts that require transparency such as covers for vehicle lighting, window glass, instruments, display panels, etc. Covers, traffic signs, display devices, display items such as advertising towers, sound insulation walls for roads, railways, etc., bridges, guardrail exteriors and paintings, tunnel interiors and paintings, insulators, solar cell covers, solar water heaters Exterior parts of electronic and electrical equipment used outside such as bars, especially transparent members, plastic houses, greenhouses, etc., especially transparent members, and environments that may be contaminated even inside, such as medical and The use of facilities and equipment for physical education can be listed.

Examples of application of the photocatalyst or functional composite of the present invention to the anti-fogging technology field include, for example, mirrors (vehicle rear-view mirrors, bathroom mirrors, bathroom mirrors, dental mirrors, road mirrors, etc.), lenses (Eyeglass lenses, optical lenses, illumination lenses, semiconductor lenses, photocopier lenses, vehicle rear-facing camera lenses, etc.), prisms, window glass of buildings and viewing towers, vehicle window glasses (automobiles, railway vehicles, aircraft) , Ships, submersibles, snow vehicles, ropeway gondola, amusement park gondola, spacecraft, etc.), vehicle windshields (automobiles, motorcycles, rail vehicles, aircraft, ships, submersibles, snow vehicles, snowmobiles, ropeways) Gondola, amusement park gondola, spacecraft, etc.), protective goggles, sports goggles, protective mask shield, sports mask shield, helmet shield, cold Glass for food display cases, glass for insulated food display cases, covers for measuring devices, covers for vehicle rear-view camera lenses, focusing lenses for laser dental treatment devices, covers for sensors for detecting laser light such as distance sensors between vehicles, Applications such as infrared sensor covers and camera filters can be mentioned.

  Examples of the application of the photocatalyst or functional composite of the present invention to the antistatic technical field include, for example, cathode ray tubes, magnetic recording media, optical recording media, magneto-optical recording media, audio tapes, video tapes, analog records, and home use. Housing and parts of electrical products and exteriors and coatings, housings and parts and exteriors and coatings of OA equipment products, building materials, building exteriors, building interiors, window frames, window glass, structural members, exteriors and coatings of vehicles, machinery and equipment Applications such as exterior, dust-proof cover and painting.

Examples of the application of the photocatalyst or the functional composite of the present invention to the antibacterial and antifungal technical fields include, for example, building materials, building exteriors, building interiors, window frames, structural members, and building equipment such as toilets, bathtubs, Wash basin, luminaire, lighting cover, kitchenware, tableware, dishwasher, dish dryer, sink, cooking range, kitchen hood, exhaust fan, cupboard, cabinet, bathroom or toilet wall, ceiling, doorknob, and even For hygiene management in medical and public facilities such as hospital parts, ambulance parts, food / pharmaceutical factories, public facilities such as schools / gymnasiums / stations, public baths, public toilets, inns, hotels, etc. In addition, applications such as walls, floors and ceilings, fixtures, fixtures and doorknobs in various places can be mentioned. In particular, it can be widely used as a hospital infection prevention method for members in hospitals. Examples of the members in the hospital include floors, walls, ceilings, handrails, door handles, water faucets in places where an unspecified number of objects come into contact, such as hospital rooms, examination rooms, corridors, stairs, elevators, waiting rooms, and washrooms. And various medical devices. In addition, the antibacterial and antifungal properties can be effectively imparted not only in hospitals but also to various members in places requiring hygiene such as ambulances, food storage rooms, and food cooking rooms.
The photocatalyst or functional composite of the present invention having a photoelectric conversion function is capable of expressing functions such as power conversion of solar energy, and is an optical semiconductor electrode used for (wet) solar cells and the like It can be used for such applications.

The present invention will be described more specifically with reference to the following examples, reference examples and comparative examples, but these do not limit the scope of the present invention in any way.
In Examples, Reference Examples and Comparative Examples, various physical properties were measured by the following methods.
1. Number average particle diameter A sample was appropriately diluted by adding a solvent so that the photocatalyst content in the sample was 1 to 20% by mass, and measured using a wet particle size analyzer (manufactured by Nikkiso Co., Ltd., Microtrac UPA-9230).

2. Number average molecular weight It calculated | required by the gel permeation chromatography (GPC) using the calibration curve created using the polystyrene sample.
The conditions for GPC are as follows.
Apparatus: Tosoh HLC-8020LC-3A type chromatograph Column: TSKgel G1000H _XL , TSKgel G2000H _XL and TSKgel G4000 _XL (all manufactured by Tosoh) were used in series.

-Data processor: CR-4A type data processor manufactured by Shimadzu Corporation-Mobile phase:
Tetrahydrofuran (used for analysis of phenyl group-containing silicone)
Toluene (used to analyze silicones that do not contain phenyl groups)
-Flow rate: 1.0 ml / min.
-Sample preparation method It diluted with the solvent used for a mobile phase (concentration was adjusted suitably in the range of 0.5-2 weight%), and used for the analysis.

3. Infrared absorption spectrum The infrared absorption spectrum was measured using a FT / IR-5300 type infrared spectrometer manufactured by JASCO Corporation.
4). Film hardness It calculated | required as pencil hardness (scratch of a film | membrane) according to JIS-K-5400.
5. Film hardness after UV irradiation The film surface was irradiated with light of a FL20SBLB type black light manufactured by Toshiba Lighting & Technology for 7 days, and then 4. It measured by the method of.
At this time, measurement was performed using a UVR-2 type ultraviolet intensity meter manufactured by Topcon, Japan {using a UD-36 type light receiving unit (corresponding to light with a wavelength of 310 to 400 nm) manufactured by Topcon, Japan as the light receiving unit}. The adjusted ultraviolet intensity was adjusted to 1 mW / cm ² .

6). Transparency Using a turbidimeter NDH2000 manufactured by Nippon Denshoku Industries Co., Ltd., haze value and total light transmittance were measured according to JIS-K-7105.
7). Contact angle of water with respect to the surface of the film A drop of deionized water was placed on the surface of the film and allowed to stand at 20 ° 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 film, the higher the hydrophilicity of the film surface.
8). Change in hydrophilicity (hydrophobicity) of the coating surface before and after UV irradiation. After irradiating with ultraviolet rays for 7 days by the above method, 7. The contact angle of water was measured by the method described above.

9. Photocatalytic activity After coating a 5% by mass ethanol solution of methylene blue on the surface of the film, the above 5. The ultraviolet rays were irradiated by the method of 5 days.
Thereafter, the activity of the photocatalyst was evaluated in the following three steps based on the degree of decomposition of methylene blue by the action of the photocatalyst (evaluated visually based on the degree of fading of the coating surface).
A: Methylene blue is completely decomposed.
Δ: Slightly methylene blue blue remains.
X: Methylene blue was hardly decomposed.

10. Weather resistance (transparency)
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 and transparency of water after 2000 hours of exposure were evaluated.
11. Contamination resistance After the test plate was attached to a fence facing a general road (traffic volume of about 500 to 1000 units / day) for 3 months, the degree of contamination was visually evaluated.

[Reference Example 1]
[Synthesis of phenyl group-containing silicone (BP)]
After adding 26.0 g of phenyltrichlorosilane to 78 g of dioxane in a reactor having a reflux condenser, a thermometer and a stirrer, the mixture was stirred at room temperature for about 10 minutes. A mixture of 3.2 g of water and 12.9 g of dioxane was added dropwise thereto over about 30 minutes while maintaining the reaction solution at 10 to 15 ° C., followed by further stirring at 10 to 15 ° C. for about 30 minutes, The reaction solution was heated to 60 ° C. and stirred for 3 hours. The resulting reaction solution was cooled to 25-30 ° C., 392 g of toluene was added dropwise over about 30 minutes, and then the reaction solution was again heated to 60 ° C. and stirred for 2 hours.

The resulting reaction solution was cooled to 10 to 15 ° C., and 19.2 g of methanol was added over about 30 minutes. Thereafter, stirring was further continued at 25-30 ° C. for about 2 hours, and then the reaction solution was heated to 60 ° C. and stirred for 2 hours. The solvent was distilled off from the resulting reaction solution at 60 ° C. under reduced pressure to obtain a phenyl group-containing silicone (BP1) having a ladder skeleton having a number average molecular weight of 1200. In the obtained phenyl group-containing silicone (BP1), absorptions (1130 cm ⁻¹ and 1037 cm ⁻¹ ) derived from the stretching vibration of the ladder skeleton in the IR spectrum were observed.

Subsequently, 100 g of the above phenyl group-containing silicone (BP1) was added to 100 g of toluene in a reactor having a reflux condenser, a thermometer, and a stirring device, and stirred at room temperature for about 10 minutes. To this was added 50 g of tetramethoxysilane oligomer (methoxy group content 65 mass%) and 7.5 g of dibutyltin dilaurate. Thereafter, the temperature of the reaction solution was raised to 80 ° C. and stirred for 3 hours, and then 125 g each of toluene and ethanol were added to the reaction solution to obtain a phenyl group-containing silicone (BP2) solution.
The number average molecular weight of the obtained phenyl group-containing silicone (BP2) was 4300.

[Reference Example 2]
[Synthesis of modified photocatalyst particles (a)]
4 g of sodium lauryl polyoxyethylene ether sulfate is added to 20 g of anatase-type titanium oxide particles obtained by hydrothermal synthesis, and 27 g of isopropanol and 68 g of toluene are added to thereby add a long-chain alkyl-modified titanium oxide having a number average particle size of 12 nm. Organosol (a1) was obtained.

[Reference Example 3]
[Synthesis of modified photocatalyst particles (a)]
45 g of the long chain alkyl-modified titanium oxide organosol (a1) prepared in Reference Example 2 was placed in a reactor having a reflux condenser, a thermometer and a stirrer, and 1 g of bis (trimethylsiloxy) methylsilane was added thereto at 40 ° C. By adding over about 5 minutes and continuing stirring at 40 ° C. for 12 hours, a silicon-modified photocatalyst organosol (a2) having a number average particle size of 17 nm was obtained.
At this time, the amount of hydrogen gas produced by the reaction of bis (trimethylsiloxy) methylsilane was 90 ml at 23 ° C. Further, when the obtained modified titanium oxide organosol 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.

[Example 1]
12.55 g of toluene, 9.5 g of isopropanol, and 8.5 g of cyclohexanone were added to 18.1 g of the phenyl group-containing silicone (BP2) synthesized in Reference Example 1, and TINUVIN-400 {trade name (manufactured by Ciba Geigy Japan) was added as an ultraviolet absorber. )} 0.018 g and TINUVIN-384-2 {trade name (manufactured by Ciba-Geigy Japan)} 0.018 g and stirred at room temperature, then 1.1 g of X-1044 {tetrakis (acetylacetonato) zirconium 20 A mass% solution (trade name of mass ratio toluene / methanol = 5/1) (manufactured by Matsumoto Pharmaceutical)} was added. To this, 0.19 g of the long-chain alkyl-modified titanium oxide organosol (a1) prepared in Reference Example 2 was added with stirring at room temperature to obtain a photocatalyst composition (C-1).
After spray-coating the photocatalyst composition (C-1) on a 10 cm × 10 cm acrylic resin plate (thickness 2 mm) to a film thickness of 2 μm, drying at room temperature for 30 minutes and heating at 80 ° C. for 30 minutes Thus, a test plate (G-1) having a photocatalyst-containing film was obtained.

The test plate (G-1) having the photocatalyst-containing film thus obtained had an average pencil hardness of 2B and an average contact angle with water of 85 °. Further, the transparency was such that the average haze value was 0, the total light transmittance was 100%, and the appearance transparency was also good.
The contact angle of water after the ultraviolet ray (black light) irradiation of the test plate (G-1) having the obtained photocatalyst-containing film was 0 °. Further, the pencil hardness was F, and the photocatalytic activity evaluation result was also very good (（).

In addition, as a result of the stain resistance evaluation of the obtained test plate (G-1), no stain was observed and very good stain resistance was shown.
Furthermore, the transparency by the exposure test (after 2000 hours) using a dew panel light control weather meter has an average haze value of 0.8, almost no change in appearance, and a water contact angle of 0 °, which is very good weather resistance. showed that.
As a result of observing the cross section of the obtained test plate (G-1) with a transmission electron microscope (TEM), almost no photocatalyst particles exist at the interface between the photocatalyst-containing film and the acrylic resin as the base material. It was observed that modified photocatalyst particles were present on the surface of the photocatalyst-containing film.

[Example 2]
12.55 g of toluene, 9.5 g of isopropanol, and 8.5 g of cyclohexanone were added to 18.1 g of the phenyl group-containing silicone (BP2) synthesized in Reference Example 1, and TINUVIN-400 {trade name (manufactured by Ciba Geigy Japan) was added as an ultraviolet absorber. )} 0.018 g and 0.018 g of TINUVIN-123 {trade name (manufactured by Ciba-Geigy Japan)} as a light stabilizer, and after stirring at room temperature, 1.1 g of X-1044 {tetrakis (acetylacetonato) zirconium 20 mass% solution (trade name (made by Matsumoto Pharmaceutical Co., Ltd.)} of mass ratio of toluene / methanol = 5/1) was added. To this, 0.19 g of the silicon-modified photocatalyst organosol (a2) prepared in Reference Example 3 was added with stirring at room temperature to obtain a photocatalyst composition (C-2).
After spray-coating the photocatalyst composition (C-2) on a 10 cm × 10 cm acrylic resin plate (thickness 2 mm) to a film thickness of 2 μm, drying at room temperature for 30 minutes and heating at 80 ° C. for 30 minutes Thus, a test plate (G-2) having a photocatalyst-containing film was obtained.

The test plate (G-2) having the resulting photocatalyst-containing film had an average pencil hardness of 3B and an average contact angle with water of 92 °. Further, the transparency was such that the average haze value was 0, the total light transmittance was 100%, and the appearance transparency was also good.
The contact angle of water after the ultraviolet ray (black light) irradiation of the test plate (G-2) having the obtained photocatalyst-containing film was 0 °. Furthermore, the pencil hardness was HB, and the photocatalytic activity evaluation result was also very good (良好).

In addition, as a result of the stain resistance evaluation of the obtained test plate (G-2), no stain was observed, and the stain resistance was very good.
Furthermore, the transparency by the exposure test (after 2000 hours) using a dew panel light control weather meter has an average haze value of 0.4, almost no change in appearance, and a water contact angle of 0 °, which is very good weather resistance. showed that.
As a result of observing the cross section of the obtained test plate (G-2) with TEM, almost no photocatalyst particles were present at the interface between the photocatalyst-containing film and the acrylic resin as the substrate, and the surface of the photocatalyst-containing film It was observed that modified photocatalyst particles were present.

[Comparative Example 1]
A photocatalyst composition (C-3) was prepared in the same manner as in Example 1 except that no ultraviolet absorber was added.
Using the obtained photocatalyst composition (C-3), the same operation as in Example 1 was performed to obtain a test plate (G-3) having a photocatalyst-containing film.
Transparency of the obtained test plate (G-3) by an exposure test (after 2000 hours) using a dew panel light control weather meter was an average haze value of 2.8, and whitening of the test plate (G-3) was observed. .
As a result of observing the cross section of the obtained test plate (G-3) with TEM, there was almost no photocatalyst particles at the interface between the photocatalyst-containing film and the acrylic resin as the substrate, but the cross section of the film was observed. Some photocatalyst particles were present at the interface with the substrate depending on the location, and this was presumed to be the cause of whitening in the weather resistance test. In Examples 1 and 2, even if some photocatalyst particles were present at the base material interface, the light did not reach the photocatalyst particles at the base material interface due to the presence of the UV absorber in the film, and thus showed good weather resistance. It is estimated to be.

  The photocatalyst or functional composite provided by the photocatalyst composition of the present invention has good transparency and weather resistance, and exhibits various functions such as antibacterial, antifouling, deodorant, NOx decomposition, etc. In addition, it can be suitably used for environmental purification such as air and water.

Claims (10)

  A photocatalyst comprising a photocatalyst particle (a), a binder component (B) and an ultraviolet absorber (U), wherein the mass ratio (a) / (B) of the photocatalyst particle (a) to the binder component (B) is 0. 0.01 / 99.99 to 5/95, the total light transmittance is 95% or more, and the surface of the photocatalyst particles (a) is irradiated with light having an energy higher than the band gap energy, so that the surface has photocatalytic activity and A photocatalyst having a hydrophilic property.   The photocatalyst body according to claim 1, further comprising a light stabilizer (H).   The photocatalyst body according to claim 1 or 2, wherein the surface energy of the photocatalyst particles (a) is smaller than that of the binder component (B). The photocatalyst according to claim 1 or 2, wherein the binder component (B) is a phenyl group-containing silicone (BP) represented by the formula (1).
R ¹ _p R ² _q X _r SiO _{(4-PQR) / 2} (1)
(In the formula, each R ¹ represents a phenyl group, and each R ^{2 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 group. Represents an alkenyl group having 2 to 30 carbon atoms, each X independently represents a hydrogen atom, a hydroxyl group, an alkoxy group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, an aminoxy group, or 1 to 20 carbon atoms. And p, q, and r are 0 <p <4, 0 ≦ q <4, 0 ≦ r <4, and 0 <(p + q + r) <4, and 0.05 ≦ p / (p + q) ≦ 1)   The photocatalyst body according to claim 1 or 2, wherein the photocatalyst particles (a) are visible light responsive photocatalysts.   The photocatalyst composition for forming the photocatalyst body of Claim 1 or 2.   3. A functional composite comprising the photocatalyst according to claim 1 or 2 formed as a film on a substrate and having a thickness of 0.1 to 100 [mu] m.   The photocatalyst is anisotropic in the distribution of the photocatalyst particles (a), and the concentration of the photocatalyst particles (a) is higher on the surface than on the surface of the photocatalyst that contacts the substrate. 8. The functional complex according to 7.   9. The functional composite according to claim 7, wherein the photocatalyst particles (a) form a layer having a thickness of 0.1 μm or less on the surface of the coating.   The functional composite according to any one of claims 7 to 9, wherein the photocatalyst particles (a) are not present on the surface in contact with the substrate.