JP2006136782A - Photocatalyst aluminum member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocatalyst aluminum member, which develops photocatalytic activity and/or hydrophilicity by the irradiation with light, by a simple method. <P>SOLUTION: The photocatalyst aluminum member is surface-treated with a photocatalyst composition containing a modified photocatalyst having waxy properties. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  Since the present invention exhibits the action of decomposing substances and hydrophilizing the surface by light energy, surface treatment with a photocatalyst represented by titanium oxide, which is known to be applied in fields such as environmental purification, antifouling, and antifogging. It is related with the photocatalyst aluminum member formed.

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 light corresponding to the band gap of the substance ( When excitation light is irradiated, excitation of electrons in the valence band (photoexcitation) occurs by 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 surfaces of various substrates plays a very important role.
For example, when developing a building member made of aluminum or an aluminum alloy (hereinafter referred to as an aluminum alloy) having the above photocatalytic properties, if the photocatalyst such as titanium oxide is coated on the panel material, the panel surface is caused by the strong redox action of the photocatalyst. There is a problem that it is easily corroded (oxidized). Further, there is a problem that sufficient adhesion between the aluminum alloy substrate and the photocatalyst cannot be obtained, and the coated photocatalyst film is easily peeled off.

  In order to solve these problems, for example, Japanese Patent Application Laid-Open No. 8-302498 discloses a semiconductor fine particle in which an anodized film is formed on the surface of a base material made of aluminum or an aluminum alloy, and further has a photocatalytic action on the anodized film. There has been proposed a building material in which a coating film containing or carrying is formed. According to the present invention, the anodic oxide film formed on the surface of the base material certainly improves the adhesion with the coating film containing or carrying the semiconductor particles having photocatalytic action formed thereon, The problem of the deterioration of the binder-coating due to the photo-oxidation function of the semiconductor fine particles having the above has not been solved. In addition, it is difficult to uniformly coat a photocatalyst on a building material having a complicated shape. Furthermore, when coating a photocatalyst, it is usually necessary to heat the substrate to a temperature exceeding 200 ° C. 60-118236 and JP-A-6-278241), when the aluminum alloy is exposed to such a temperature, the strength of the aluminum alloy is significantly reduced.

For the reasons mentioned above, it has been self-cleaning for a long time, it is a simple method that does not require any special equipment, and it is coated with a photocatalyst with a good appearance under mild conditions. An aluminum member having a photocatalytic film having functions such as moldability has been desired.
JP-A-8-302498 JP 60-118236 A JP-A-6-278241

  The subject of this invention is providing the photocatalytic aluminum member which expresses photocatalytic activity and / or hydrophilicity by light irradiation by a simple method.

  As a result of intensive studies, the present inventors have found that a photocatalyst composition containing a modified photocatalyst having a wax property that has been modified using a specific modifier compound has a good appearance under mild conditions such as room temperature. A member that can be coated with a photocatalyst and has been treated with the composition has been found to exhibit photocatalytic activity and / or hydrophilicity upon irradiation with light, and has led to the present invention.

That is, the present invention is as follows.
1. The photocatalyst (a) is surface-treated with a photocatalyst composition (C) containing a modified photocatalyst (A) having a wax property that has been modified using the modifier compound (b) represented by the formula (1). Photocatalytic aluminum member.
_{R x X y Q z SiO (} 4-x-y-z) / 2 (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 number having 1 to 30 carbon atoms. It represents a group consisting of one or more selected from a fluoroalkyl group, a linear or branched alkenyl group having 2 to 30 carbon atoms, and a phenyl group.
Q represents a C1-C30 organic group containing a group represented by the following formula (2) or a group represented by the following formula (2).
— (O) _a R ¹ O (R ² O) _b R ³ (2)
(Wherein R ¹ and R ² each independently represents a linear or branched alkylene group having 1 to 10 carbon atoms. R ³ represents a hydrogen atom, a linear or branched carbon group having 1 to 30 carbon atoms. An alkyl group, a cycloalkyl group having 5 to 20 carbon atoms, or a linear or branched alkenyl group having 2 to 30 carbon atoms and a phenyl group, a is 0 or 1, and b is an integer of 1 to 100 Represents.)
X represents each independently 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, an oxime group having 1 to 20 carbon atoms, or a halogen atom. Further, 0 ≦ x <4, 0 ≦ y <4, 0 <z <4, and 0 <(x + y + z) <4. )

2. The above invention 1, wherein the photocatalyst composition (C) contains a sensitizing dye (D). Photocatalytic aluminum member.
3. The invention 1 above, wherein the photocatalyst composition (C) contains water and / or alcohol. Or 2. Any of the photocatalytic aluminum members.
4). The above invention 1, wherein the photocatalyst composition (C) comprises an amino group-containing silane coupling agent. ~ 3. Any of the photocatalytic aluminum members.
5. The invention 1, wherein the photocatalyst composition (C) contains a surfactant. ~ 4. Any of the photocatalytic aluminum members.
6). The invention 1 characterized by having a wax property. ~ 5. A photocatalytic aluminum member which is surface-treated with any one of the photocatalytic composition (C).

7). The invention according to the invention 1, which exhibits photocatalytic activity and / or hydrophilicity by irradiating light having energy higher than the band gap energy of the photocatalyst (a) to be contained. Photocatalytic aluminum member.
8). The invention 2 characterized by exhibiting photocatalytic activity and / or hydrophilicity by irradiating light having an energy higher than the band gap energy of the contained sensitizing dye and / or the photocatalyst (a). . Photocatalytic aluminum member.
9. The invention according to the invention 7, which has antifouling performance. Or 8. Photocatalytic aluminum member.
10. The above invention 7, which has antibacterial performance. Or 8. Photocatalytic aluminum member.
11. Invention 1 above. ~ 5. A surface treatment method for an aluminum member, wherein the photocatalyst composition (C) is applied to the aluminum member and then spread.

  Since the photocatalyst composition of the present invention can be coated with a photocatalyst with a good appearance under mild conditions in a simple manner, it is possible to provide a photocatalytic aluminum building material that exhibits photocatalytic activity and / or hydrophilicity by light irradiation by the coating. it can.

Hereinafter, the present invention will be described in detail.
The photocatalytic aluminum member of the present invention is characterized by being surface-treated with a photocatalyst composition (C) containing a modified photocatalyst (A) having a wax property.
Here, the wax property in the present invention means one that passes the evaluation of ease of spreading and wiping in the JIS K 2236 test.
Further, the modified photocatalyst (A) having a wax property in the present invention preferably has a spreadability measured by the following spreadability test of 10 cm or more, more preferably a spreadability of 50 cm or more, and spreadability. Is more preferably 200 cm or more. Furthermore, the photocatalyst composition (C) containing the modified photocatalyst (A) of the present invention preferably has a spreadability measured by the following spreadability test of 5 cm or more, and further has a spreadability of 50 cm or more. It is preferable that the spreadability is 200 cm or more.

(Coating test)
1) A dispersion of a modified photocatalyst dispersed in a solvent (a solvent having a boiling point of 100 ° C. or less, preferably water) so as to be 5% by mass is dropped on a glass plate in an amount of about 0.03 g (one drop with a dropper), Dry at 105 ° C. for 30 minutes.
2) Cool for 30 minutes at 23 ° C and 55% humidity.
3) The dried modified photocatalyst on the glass plate is stretched with a plastic spatula, the length until the formed modified photocatalyst film starts to break, and the elongation (cm) per 0.01 g of the modified photocatalyst is spread out. Sexually.

The modified photocatalyst (A) of the present invention is obtained by modifying the photocatalyst (a) with at least one modifier compound (b) described later.
In the present invention, the modification means that at least one modifier compound (b) described later is immobilized on the surface of the photocatalyst (a). Immobilization of the above-described modifier compound on the surface of the photocatalyst particles is due to van der Waals force (physical adsorption), Coulomb force or chemical bonding. it is conceivable that. 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, the photocatalyst (a) refers to a substance that causes an oxidation or reduction reaction by light irradiation. 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. For example, oxidative decomposition reaction of various organic substances can be mentioned. Therefore, if this photocatalyst is supported on the surface of the aluminum member, various organic substances (contaminants) adhering to the aluminum member can be oxidized and decomposed using light energy, and the surface of the aluminum member is made hydrophilic. It becomes possible to keep it.

  In the present invention, the photocatalytic activity means that an oxidation or reduction reaction is caused by light irradiation. For example, it is possible to determine whether or not the surface is photocatalytically active by measuring the decomposability of organic substances such as pigments at the time of light irradiation. The surface having photocatalytic activity has excellent decomposition activity of contaminating organic substances such as bacteria and fungi, and exhibits antifouling properties, antibacterial properties and fungicidal properties.

  Examples of the photocatalyst (a) that can be usefully used in the present invention include a semiconductor compound having a band gap energy of preferably 1.2 to 5.0 eV, more preferably 1.5 to 4.1 eV. If the band gap energy is less than 1.2 eV, the ability to cause oxidation and reduction reaction by light irradiation is very weak, which is not preferable. If the band gap energy is larger than 5.0 eV, the energy of light necessary for generating holes and electrons becomes very large, which is not preferable. Band gap energy is the energy difference between a valence band and a conduction band in a semiconductor such as a photocatalyst, and is usually calculated by measuring the absorption start wavelength of a light absorption spectrum. The

Examples of the photocatalyst (a) include 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 and the} like, and further a layered oxide having at least one element selected from Ti, Nb, Ta, and V (for example, JP 62-74452 A, JP 2-172535 A, JP-A-7-24329, JP-A-8-89799, JP-A-8-89800, JP-A-8-89804, JP-A-8-198061 JP-9-248465, JP-A No. 10-99694 and JP-reference Publication No. Hei 10-244165) can be mentioned.
Of these photocatalysts (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.

  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 photocatalyst (a) used in the present invention, The photocatalytic aluminum member surface-treated with the photocatalyst composition of the invention 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. The bandgap energy of these visible light responsive photocatalysts is preferably 1.2 to 3.1 eV, more preferably 1.5 to 2.9 eV, and still more preferably 1.5 to 2.8 eV.

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. Oxynitride compounds such as JP-A-2002-66333, oxysulfide compounds such as Sm ₂ Ti ₂ S ₂ O ₇ (see JP-A-2002-233770, for example), 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 , and Na ₂ Sb ₂ O ₆ (see, for example, JP 2002-59008 A), ammonia and urea In the presence of nitrogen-containing compounds such as titanium oxide precursors (titanium oxysulfate, titanium chloride, alkoxytita Etc.) or 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, JP 2001-207082 A). See), sulfur-doped titanium oxide obtained by firing titanium oxide precursors (titanium oxysulfate, titanium chloride, alkoxytitanium, etc.) in the presence of sulfur compounds such as thiourea, hydrogen plasma treatment or under vacuum Or oxygen-deficient titanium oxide obtained by heat treatment (for example, see JP-A-2001-98219), and further, photocatalyst particles are treated with a halogenated platinum compound (for example, JP-A-2002-239353). And treatment with tungsten alkoxide (see JP 2001-286755 A). The surface-treated photocatalyst obtained by this can be mentioned suitably.

Among the visible light responsive photocatalysts, oxynitride compounds and oxysulfide compounds have a large photocatalytic activity by visible light and can be used particularly preferably.
The oxynitride compound that can be particularly preferably used in the present invention is an oxynitride containing a transition metal, and preferably has a high photocatalytic activity, and the transition metal is preferably selected from the group consisting of Ta, Nb, Ti, Zr, and W. The oxynitride is characterized in that it further comprises at least one element selected from the group consisting of alkali, alkaline earth and group IIIB metals. The oxynitride further includes at least one metal element selected from the group consisting of Ca, Sr, Ba, Rb, La, and Nd.

Examples of oxynitride containing the transition _{metal, LaTiO 2 N, La v Ca} w TiO 2 N (v + w = 3), La v Ca w TaO 2 N (v + w = 3), LaTaON 2, CaTaO 2 N, General formula AMO _x N _y such as SrTaO ₂ N, BaTaO ₂ N, CaNbO ₂ N, CaWO ₂ N, SrWO ₂ N (A = alkali metal, alkaline earth metal, group IIIB metal; M = Ta, Nb, Ti, Zr, W; x + y = 3), TaON, NbON, WON, Li ₂ LaTa ₂ O ₆ N, and the like. Among these, LaTiO ₂ N, La _v Ca _w TiO ₂ N (v + w = 3), La _v Ca _w TaO ₂ N (v + w = 3), and TaON are preferable because the photocatalytic activity in visible light is very large.

The oxysulfide compound that can be used particularly preferably in the present invention is an oxysulfide containing a transition metal, and has a high photocatalytic activity, and the transition metal is preferably selected from the group consisting of Ta, Nb, Ti, Zr, and W. Oxysulfide, characterized in that it is at least one, more preferably at least one element selected from the group consisting of alkali, alkaline earth and group IIIB metals More preferably, the oxysulfide is characterized by further containing a rare earth element.
Examples of the oxysulfide containing the transition metal include Sm ₂ Ti ₂ S ₂ O ₅ , Nd ₂ Ti ₂ S ₂ O ₅ , La ₆ Ti ₂ S ₈ O ₅ , Pr ₂ Ti ₂ S ₂ O ₅ , and Sm _3. NbS ₃ O _{4 and the} like can be mentioned. Among these, Sm ₂ Ti ₂ S ₂ O ₅ and Nd ₂ Ti ₂ S ₂ O ₅ are very preferable because of their very high photocatalytic activity under visible light.

Further, as a photocatalyst (a) in the present invention, a metal-modified apatite obtained by ion-exchange of a part of metal ions in an apatite crystal with a metal ion of a metal oxide having a photocatalytic action (for example, titanium ion) 2000-327315 public information) can also be suitably used because of its excellent adsorption characteristics against bacteria, viruses, dirt and the like.
Furthermore, the above-mentioned photocatalyst (a) is preferably added or fixed with a metal such as Pt, Rh, Ru, Nb, Cu, Sn, Ni, Fe and / or an oxide thereof, or coated with porous calcium phosphate or the like. It can also be used as a photocatalyst (see, for example, JP-A-10-244166).

The crystal particle size (primary particle size) of the photocatalyst (a) is preferably 1 to 5000 nm, and more preferably a photocatalyst of 1 to 500 nm is suitably selected.
As the form of the photocatalyst (a) used in the present invention, 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.

  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 and methyl isobutyl ketone, ethers such as tetrahydrofuran and dioxane Amides such as dimethylacetamide and dimethylformamide, halogen compounds such as chloroform, methylene chloride and carbon tetrachloride, dimethyl sulfoxide, nitrobenzene, and a mixture of two or more of these.

  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 the dispersion medium contains about 80% or more of water.) Such sol adjustment is known and can be easily produced (for example, (See 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 hydrosol, titanium oxide particles are peptized under the action of acid or alkali, or dispersion stabilizer such as sodium polyacrylate is used as required without using acid or alkali. Sols that are used and dispersed in water under strong shear forces can also be used. Furthermore, an anatase-type titanium oxide sol having excellent dispersion stability even in an aqueous solution with a pH near neutral and having a particle surface modified with a peroxo group can be easily obtained by, for example, 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., “TO-240” manufactured by Tanaka Transfer Co., Ltd., etc.)
The solid content in the titanium oxide hydrosol is preferably 50% by mass or less, more preferably 30% by mass or less. More preferably, it is 30 mass% or less and 0.1 mass% or more.
Further, 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-9-25123). No. 9-67124, JP-A-9-227122, JP-A-9-227123, JP-A-10-259023, etc.), etc. Similarly known.

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-4110” 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.

  In addition, a titanium oxide organosol in which an organic solvent is substantially used as a dispersion medium and titanium oxide particles are dispersed therein is also commercially available (for example, “TKS-251” manufactured by Teika Co., Ltd.). Here, substantially using an organic solvent as a dispersion medium means that the dispersion medium contains about 20% by mass or more of the organic solvent.

  In the present invention, the properties of the photocatalyst particles (a) to be used are important factors for the dispersion stability of the modified photocatalyst (A), film formability, and expression of various functions. The photocatalyst (a) used in the present invention has a number average dispersed particle size of a mixture of primary particles and secondary particles (which may be either primary particles or secondary particles) of 5 μm or less, preferably 800 nm. The following photocatalyst particles are desirable because the wax properties are very good. In particular, when photocatalyst particles having a number average dispersed particle diameter of 100 nm or less are used, a film having excellent transparency can be obtained from the resulting modified photocatalyst (A), which is very preferable. 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. Conventionally, a numerical value simply displayed as a particle diameter in titanium dioxide or the like is mostly a primary particle diameter (crystal particle diameter), and is not a numerical value considering a secondary particle diameter due to aggregation.

The modified photocatalyst (A) used in the photocatalyst composition of the present invention is a photocatalyst having a wax property obtained by modifying the photocatalyst (a) with the modifier compound (b) represented by the formula (1).
_{R x X y Q z SiO (} 4-x-y-z) / 2 (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 number having 1 to 30 carbon atoms. It represents a group consisting of one or more selected from a fluoroalkyl group, a linear or branched alkenyl group having 2 to 30 carbon atoms, and a phenyl group.

Q represents a C1-C30 organic group containing a group represented by the following formula (2) or a group represented by the following formula (2).
— (O) _a R ¹ O (R ² O) _b R ³ (2)
(Wherein R ¹ and R ² each independently represents a linear or branched alkylene group having 1 to 10 carbon atoms. R ³ represents a hydrogen atom, a linear or branched carbon group having 1 to 30 carbon atoms. An alkyl group, a cycloalkyl group having 5 to 20 carbon atoms, or a linear or branched alkenyl group having 2 to 30 carbon atoms and a phenyl group, a is 0 or 1, and b is an integer of 1 to 100 Represents.)
X represents each independently 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, an oxime group having 1 to 20 carbon atoms, or a halogen atom. Further, 0 ≦ x <4, 0 ≦ y <4, 0 <z <4, and 0 <(x + y + z) <4. )

  In the present invention, the group of the above formula (2) in the modifier compound (b) represented by the formula (1) has a number average molecular weight of 200 to 5000 particularly in terms of imparting a wax property to the modified photocatalyst (A). The group can be suitably selected. Further, the content of the group of the formula (2) in the modifier compound (b) is preferably 30 to 99.9% by mass, more preferably 50 to 99% by mass, particularly 70 to 90% by mass. If a material is selected, the effect of imparting wax properties to the modified photocatalyst (A) becomes very large, which is preferable.

Specific examples particularly suitable as the group of the above formula (2) in the present invention include, for example, a monomethyl polyoxyethylene group, a monomethyl polyoxypropylene group, a monomethyl polyoxytetramethylene group, a monomethyl polyoxy group having a number average molecular weight of 200 to 5,000. (Oxyethylene-oxypropylene) group, monomethyl poly (oxyethylene-oxytetramethylene) group and the like can be exemplified.
Further, when the photocatalyst composition (C) of the present invention is aqueous, it contains a modified photocatalyst (A) modified with a modifier compound (b) having a polyoxyethylene unit as the group of the above formula (2). It is very preferable from the viewpoint of achieving both the water dispersion stability and the wax properties of the modified photocatalyst (A).

In the present invention, when a compound having a reactive group (X) (0 <y <4 in the formula (1)) is used as the modifier compound (b) used for modification of the photocatalyst (a), This is preferable because the interaction between a) and the modifier compound (b) becomes very large.
In the present invention, the modification of the photocatalyst (a) with the modifier compound (b) is preferably performed by using the above-described photocatalyst (a) and the modifier compound (b) in the presence or absence of water and / or an organic solvent. Is mixed at a mass ratio (a) / (b) = 1/99 to 99.99 / 0.01, more preferably (a) / (b) = 10/90 to 99 / 0.1, preferably Can be obtained by performing operations such as heating at 0 to 200 ° C., more preferably 10 to 80 ° C., or changing the solvent composition of the mixture by (reduced pressure) distillation or the like.

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

In the present invention, when the modifier compound (b) used for modification of the photocatalyst (a) is one containing a Si-H group, the particle surface of the photocatalyst (a) can be modified very efficiently. Therefore, it is preferable.
As a preferable example of the modifier compound (b) having the Si—H group, for example, a Si—H group-containing compound (b1) represented by the formula (3) and / or the formula (4) can be exemplified.
_{H- (R 2 SiO) m -SiR} 2 -Q (3)
(In the formula, R and Q are as defined in formula (1). M is an integer, and 0 ≦ m ≦ 1000.)
(RHSiO) _p (R ₂ SiO) _q (RQSiO) _r (R ₃ SiO _1/2 ) _s (4)
(Wherein R and Q are as defined in formula (1)).
p is an integer of 1 or more, q and r are 0 or an integer of 1 or more, (p + q + r) ≦ 10000, and s is 0 or 2. However, when (p + q + r) is an integer of 2 or more and s = 0, the H silicone compound is a cyclic silicone compound, and when s = 2, the H silicone compound is a chain silicone compound. )

In the present invention, the modification treatment of the photocatalyst (a) with the Si—H group-containing compound (b1) represented by the formula (3) and / or the formula (4) is performed in the presence or absence of water and / or an organic solvent. Below, the photocatalyst (a) and the Si—H group-containing compound (b1) are preferably mass ratio (a) / (b1) = 1/99 to 99.9 / 0.1, more preferably (a) / (B1) = A ratio of 10/90 to 99/1, preferably by mixing at 0 to 200 ° C.
By this modification operation, hydrogen gas is generated from the mixed solution, and when the photocatalyst sol is used as the photocatalyst (a), an increase in the average particle diameter is observed.
When titanium oxide is used as the photocatalyst (a), a decrease in Ti—OH group is observed as a decrease in absorption or disappearance of 3630 to 3640 cm ^{−1 in} the IR spectrum by the above modification operation.

Accordingly, the modified photocatalyst (A) modified with the Si—H group-containing compound (b1) represented by the formula (3) and / or the formula (4) is the Si—H group-containing compound (b1). It can be predicted that some kind of interaction is caused between the two and the photocatalyst (a) due to a chemical reaction.
In fact, the modified photocatalyst (A) thus obtained is very excellent in dispersion stability in solvents, wax properties, transparency, chemical stability, durability, and the like.
A preferred form of the modified photocatalyst (A) of the present invention is that the number average dispersed particle size of the mixture of primary particles and secondary particles (which may be either primary particles or secondary particles) of the modified photocatalyst is 5 μm or less, Preferably they are 1 nm or more and 800 nm or less, Especially preferably, they are 5 nm or more and 100 nm or less. It is preferably in a sol or water dispersion state. A smaller number average dispersed particle size is more desirable because it can cover a large area with a small amount and is inconspicuous when attached to the surface.

  When the photocatalyst composition (C) of the present invention containing a sensitizing dye (D) is used, the aluminum member that is surface-treated with the photocatalyst composition (C) has a photocatalyst (a) like titanium oxide. Even those that do not exhibit photocatalytic activity for light in the visible light region are preferred because they exhibit photocatalytic activity upon irradiation with visible light absorbed by the sensitizing dye (D). Here, the sensitizing dye (D) that can be used in the present invention refers to various metal complexes and organic dyes having absorption in the visible light region. Examples of such sensitizing dyes include xanthene dyes, oxonol dyes, cyanine dyes, merocyanine dyes, rhodocyanine dyes, styryl dyes, hemicyanine dyes, merocyanine dyes, phthalocyanine dyes (metal complexes). ), Porphyrin dyes (including metal complexes), triphenylmethane dyes, perylene dyes, coronene dyes, azo dyes, nitrophenol dyes, and JP-A 1-220380 and patent application publications Examples thereof include a complex of ruthenium, osmium, iron, and zinc described in JP-A-5-504023 and a metal complex such as ruthenium red.

  Among these sensitizing dyes, those having absorption in a wavelength region of 400 nm or more and having the lowest empty orbital energy level (excited state redox potential) higher than the energy level of the photocatalytic conduction band are preferably selected. Is done. Such spectral sensitizing dyes are selected by measuring the absorption spectrum of light in the infrared, visible, and ultraviolet regions, and measuring the redox potential by an electrochemical method (T. Tani, Photogr. Sci. Eng., 14, 72 (1970), etc.), energy level calculation using molecular orbital method (T. Tani, etal., Photogr. Sci. Eng., 11, 129 (1967), etc.), and also created by photocatalyst and spectral sensitizing dye The Gretzel type wet solar cell can be implemented depending on the presence or absence of electromotive force due to light irradiation and the efficiency.

Examples of preferred sensitizing dyes from such a viewpoint include compounds having a 9-phenylxanthene skeleton (such as fluorescein, eosin Y, eosin B, rose bengal, rhodamine B, phloxine, pyrogallol, uranin, acid red, etc.) Examples thereof include a ruthenium complex containing a 2,2-bipyridine derivative as a ligand, ruthenium red, a compound having a perylene skeleton, a phthalocyanine metal complex, and a porphyrin metal complex.
In the photocatalyst composition of the present invention, the mass ratio of the modified photocatalyst (A) to the sensitizing dye (D) is preferably (A) / (D) = 1/99 to 99.999 / 0.001, more preferably. (A) / (D) = 50/50 to 99.99 / 0.01.

In the photocatalyst composition (C) of the present invention, when the plasticizer (E) is added to the modified photocatalyst (A) at a mass ratio (A) / (E) = 1/99 to 99/1, the wax property is further improved. Highly preferred.
The plasticizer is preferably a compound having a boiling point of 150 ° C. or more and a molecular weight of 50,000 or less. For example, silicone derivatives, alkylene oxide derivatives, aliphatic dibasic acid esters such as di (2-ethylhexyl) adipate, triphosphate phosphate, and the like. Examples include phosphoric acid triesters such as (2-ethylhexyl), glycol esters, dibutyl phthalate, di-n-octyl phthalate, diphthalyl phthalate and other phthalic acid diesters, tetralin paraffin, and isoparaffin.

Among these plasticizers (E), an ethylene glycol derivative and a propylene glycol derivative are preferable because of good compatibility with the modified photocatalyst (A) of the present invention. Specific examples thereof include polyethylene glycol, polyethylene glycol monomethyl ether, polyethylene glycol glyceryl ether, poly (ethylene glycol-tetramethylene glycol), poly (ethylene glycol-propylene glycol) and the like having a number average molecular weight of 200 to 5,000. Can be listed.
In the photocatalyst composition of the present invention, one containing a solvent is very preferable for surface treatment of an aluminum member. At this time, it is preferable that the modified photocatalyst (A) is uniformly dispersed in a solvent. In addition, as the amount of the solvent, the total content of the modified photocatalyst (A) and the sensitizing dye (D) is preferably 0.0001 to 30% by mass, more preferably 0.001 to 5% by mass.

Examples of the solvent that can be suitably used in the photocatalyst composition of the present invention include water and / or an organic solvent.
Examples of the organic solvent include hydrocarbon solvents having 8 to 20 carbon atoms, alcohol solvents such as alcohol and polyhydric alcohol, ether solvents, and the like. Specific examples of the hydrocarbon solvent include decane, undecane, dodecane, paraffin or isoparaffin, and specific examples of the alcohol solvent include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, Examples include 2-butanol, denatured ethanol (8-acetyl sucrose denatured alcohol), ethylene glycol or glycerin. Specific examples of ether solvents include monoalkyl monoglyceryl ethers having 1 to 12 carbon atoms in the alkyl chain, diethylene glycol Monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether , Propylene glycol monobutyl ether, dipropylene glycol monoethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monobutyl ether or di or tetraethylene glycol monophenyl ether.

  As a solvent suitably used for the photocatalyst composition of the present invention, water and / or alcohol is preferable. Examples of the alcohol include ethanol, modified ethanol, glycerin, monoalkyl monoglyceryl ether having 3 to 8 carbon atoms in the alkyl chain, propylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, dipropylene. Glycol monoethyl ether, dipropylene glycol monobutyl ether or di to tetraethylene glycol monophenyl ether is preferred. In particular, when a mixture of water / ethanol = 95/5 to 10/90 mass ratio is used as the solvent, the wettability of the photocatalyst composition of the present invention to the aluminum member becomes very good, which is preferable.

  In the photocatalyst composition of the present invention, the amino group-containing silane coupling agent (F) is further in a mass ratio (A) / (F) = 99.9 / 0.1 to 10/90 with respect to the modified photocatalyst (A). When it is contained, the fixability of the photocatalyst composition to the member is greatly improved, which is preferable. Examples of the amino group-containing silane coupling agent include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyldimethylmethoxysilane, γ-aminopropylmethyldisilane. Ethoxysilane, γ-aminopropyldimethylethoxysilane, γ- (2-aminoethyl) -aminopropyltrimethoxysilane, γ- (2-aminoethyl) -aminopropyltriethoxysilane, γ- (2-aminoethyl)- Preferred examples include aminopropylmethyldimethoxysilane and γ- (2-aminoethyl) -aminopropyldimethylmethoxysilane.

  In addition, the photocatalyst composition of the present invention has an object of improving wettability to members and dirt components, and improving adhesion, coating property, spreadability, and dispersibility of the modified photocatalyst (A) in a solvent. Therefore, it is preferable to add the surfactant (G) at a mass ratio (A) / (G) = 99.99 / 0.01 to 10/90 with respect to the modified photocatalyst (A). As the surfactant that can be added, at least one selected from nonionic surfactants, amphoteric surfactants, cationic surfactants and anionic surfactants is appropriately selected according to various members. Is desirable.

  Examples of the nonionic surfactant include polyoxyethylene alkyl phenyl ether, polyoxypropylene alkyl phenyl ether, polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, polyoxyethylene alkyl ester, polyoxypropylene alkyl ester, polyethylene glycol Alkyl ester, polypropylene glycol alkyl ester, alkyl amine polyethylene glycol ether, alkyl amine polypropylene glycol ether, alkyl diamine polyethylene glycol ether, alkyl diamine polypropylene glycol ether, alkyl amide polyethylene glycol ether, alkyl amide polyprolene glycol ether, alkyl amine oxide, alkyl Luamide amine oxide, polyethylene glycol, polypropylene glycol, glycerin, sorbitol, pentaerythritol, trimethylolpropane, fluoroalkyl group-containing ethylene oxide adduct, fluoroalkyl group-containing propylene oxide adduct, organopolysiloxane ethylene oxide adduct, organopolysiloxane propylene oxide Addenda. The number of carbon atoms in the alkyl group including the alkyl group is preferably 6-22.

Examples of the amphoteric surfactant include imidazolinium betaine type, amidopropyl betaine type, glycine type, and alanine type.
Examples of the cationic surfactant include tetramethylammonium salt, tetraethylammonium salt, tetrabutylammonium salt, alkyltrimethylammonium salt, dialkyldimethylammonium salt, trialkylmethylammonium salt, trimethylphenylammonium salt, triethylphenylammonium salt, tributyl Phenylammonium salt, alkyldimethylbenzylammonium salt, alkyldiethylbenzylammonium salt, alkyldibutylbenzylammonium salt, benzyltrimethylammonium salt, benzyltriethylammonium salt, benzyltributylammonium salt, dialkanol polyethylene glycol ether alkylmethylammonium salt, dipolypropylene glycol Alkanol ether Kill methyl ammonium salts, alkylamine salts, alkanolamine salts, polyethylene glycol alkanol ether amine salts, polypropylene glycol alkanol ether amine salts. The number of carbon atoms in the alkyl group including the alkyl group is preferably 6-22.

  Examples of the anionic surfactant include alkylbenzene sulfonate, alkyl sulfate ester salt, alkyl ether sulfonate, alkyl phenyl ether sulfonate, methyl taurate, alaninate salt, sulfosuccinate, alkyl ether sulfonate, Alkylamide sulfate, alkanol nitrate, carboxylic acid nitrate, alkanol phosphate, fluoroalkyl group-containing sulfonate, fluoroalkyl group-containing carboxylate, organopolysiloxane-containing sulfonate, organopolysiloxane-containing carboxylate Can be given. The number of carbon atoms in the alkyl group including the alkyl group is preferably 6-22.

In the photocatalyst composition of the present invention, one containing an antibacterial metal (H) in a mass ratio (A) / (H) = 99.999 / 0.001 to 90/10 with respect to the modified photocatalyst (A) is selected. Then, since an antibacterial and antifungal function can be expressed more efficiently, it is preferable. In other words, antibacterial metals are known to have antibacterial and strong antibacterial and antifungal effects due to photocatalysis when exposed to light. Can be combined with antibacterial and antifungal effects of antibacterial metals in the dark.
Examples of the antibacterial metal that can be used in the present invention include metals such as silver, copper, platinum, gold, palladium, nickel, cobalt, rhodium, niobium, tin, and / or oxides thereof and mixtures thereof. Can do. Among these, it is preferable to use silver or copper.

The antibacterial metal can be used by simply adding it to the photocatalyst composition or immobilizing it on the modified photocatalyst (A). Examples of the method for immobilizing the antibacterial metal on the modified photocatalyst (A) include a method of physically adsorbing the antibacterial metal, a method of immobilization by a photoreduction method and heat treatment. Alternatively, the antibacterial metal can be immobilized on the photocatalyst (a) by physical adsorption, photoreduction, heat treatment, etc., and then modified by the above-described method using the modifier compound (b).
In addition, in the photocatalyst composition of the present invention, the resin (I) is added to the modified photocatalyst (A) of the present invention in a mass ratio (A) / (I) = for the purpose of assisting the fixing property to the aluminum member. You may make it contain by 1 / 99-99 / 1, Preferably (A) / (I) = 10 / 90-90 / 10. At this time, since it is not preferable to contain a resin that hinders the spreadability of the photocatalyst composition of the present invention, the content of the resin can pass the evaluation of ease of spreading and wiping of the photocatalyst composition in the JISK 2236 test. The range is preferable.

As the resin (I) that can be contained in the photocatalyst composition of the present invention, all synthetic resins and natural resins can be used.
As the synthetic resin, thermoplastic resin and curable resin (thermosetting resin, photocurable resin, moisture curable resin, etc.) can be used. For example, 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, 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, water glass and zirconi Beam 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.
Among these resins, silicon resins that are hardly decomposable with respect to the photocatalyst are preferably used. Examples of such silicon-based resins include alkoxysilanes and / or organoalkoxysilanes and their hydrolysis products (polysiloxanes) and / or colloidal silica, and acrylic-silicon resins having a silicon content of 1 to 80% by weight. , Epoxy-silicone resin, urethane-silicone resin, alkoxysilane and / or organoalkoxysilane, a hydrolysis product thereof (polysiloxane) and / or a resin containing 1 to 80% by weight of colloidal silica. These silicon resins may be any of a solvent-soluble type, a dispersion type, and a powder type, and may contain additives such as a crosslinking agent and a catalyst.

  Specific examples of the alkoxysilane and / or organoalkoxysilane include tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, and tetra-n-butoxysilane; Methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, n- Butyltrimethoxysilane, n-butyltriethoxysilane, n-pentyltrimethoxysilane, n-hexyltrimethoxysilane, n-heptyltrimethoxysilane, n-octyltrimethoxysilane, vinyltrimethoxy Sisilane, vinyltriethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3,3,3-tri Fluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane,

2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3- Mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxy Silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloxy Trialkoxysilanes such as propyltrimethoxysilane, 3- (meth) acrylicoxypropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane; dimethyldimethoxysilane, dimethyldiethoxysilane, Diethyldimethoxysilane, diethyldiethoxysilane, di-n-propyldimethoxysilane, di-n-propyldiethoxysilane, di-i-propyldimethoxysilane, di-i-propyldiethoxysilane, di-n-butyldimethoxysilane Di-n-butyldiethoxysilane, di-n-pentyldimethoxysilane,
Di-n-pentyldiethoxysilane, di-n-hexyldimethoxysilane, di-n-hexyldiethoxysilane, di-n-heptyldimethoxysilane, di-n-heptyldiethoxysilane, di-n-octyldimethoxysilane Dialkoxysilanes such as di-n-octyldiethoxysilane, di-n-cyclohexyldimethoxysilane, di-n-cyclohexyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane; trimethylmethoxysilane, trimethylethoxysilane, etc. And monoalkoxysilanes. Of these, trialkoxysilanes and dialkoxysilanes are preferable. As the trialkoxysilanes, methyltrimethoxysilane and methyltriethoxysilane are preferable. As dialkoxysilanes, dimethyldimethoxysilane and dimethyldimethoxysilane are preferable. Ethoxysilane is preferred. These alkoxysilanes and / or organoalkoxysilanes can be used alone or in admixture of two or more.

When the above alkoxysilane and / or organoalkoxysilane is used as a hydrolysis product (polysiloxane), the polystyrene equivalent weight average molecular weight of the partial condensate is preferably 400 to 100,000, more preferably 800 to 50,000. .
In addition, the photocatalyst composition of the present invention includes an antifoaming agent, a wax, a fragrance, an antifungal agent, a chelating agent, an antioxidant, a pH adjusting agent, an ultraviolet absorber, a pigment, a dye, an inorganic filler, and a crosslinking agent as necessary. , Light stabilizers, preservatives, and the like can be selected and combined according to their respective purposes.

  In the modified photocatalyst (A) contained in the photocatalyst composition of the present invention, the surface of the photocatalyst (a) is modified with a modifier compound (b) whose skeleton structure does not change due to photocatalytic activity. Difficult to come in contact with members directly. Therefore, even when the modified photocatalyst (A) of the present invention is used for the treatment of an aluminum member, the base coat for protecting the aluminum member from corrosion or the like is not essential, and the band gap energy of the contained photocatalyst (a) Exhibits excellent photocatalytic activity and / or hydrophilicity by irradiating light with higher energy and / or absorption light of the contained sensitizing dye (D), and exhibiting soil decomposition performance and environmental purification function over a long period of time Can do.

The photocatalyst composition (C) of the present invention contains a modified photocatalyst (A) obtained by modifying the photocatalyst (a) with a modifier compound (b ′) represented by the following formula (1) ′, for example. In this case, the photocatalytic aluminum member treated with the photocatalyst composition (C) has a higher energy than the band gap energy of the photocatalyst (a) and / or the absorbed light of the sensitizing dye (D) contained. Irradiation first shows a unique behavior in which the water contact angle increases (hydrophobizes) and then the water contact angle decreases (hydrophilization). This phenomenon is caused by the hydrophobization caused by firstly decomposing hydrophilic polyoxyethylene units by photocatalysis by photoirradiation, and then at least a part of the hydrophobic Si-R groups is converted into hydrophilic Si-OH groups. It is presumed to be due to hydrophilization by conversion by photocatalytic action.
_{R t X y Q 'z SiO} (4-x-y-z) / 2 (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 number having 1 to 30 carbon atoms. It represents a group consisting of one or more selected from a fluoroalkyl group, a linear or branched alkenyl group having 2 to 30 carbon atoms, and a phenyl group.

Q ′ represents a C 1-30 organic group containing a group represented by the following formula (2) ′ or a group represented by the following formula (2) ′.
_{- (O) a CH 2 CH} 2 O (CH 2 CH 2 O) b R 3 (2) '
(In the formula, R ³ is a hydrogen atom, 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 number having 2 to 30 carbon atoms. A represents 0 or 1, and b represents an integer of 1 to 100.)
X represents each independently 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, an oxime group having 1 to 20 carbon atoms, or a halogen atom. Further, 0 <t <4, 0 <y <4, 0 <z <4, and 0 <(x + y + z) <4. )

In the present invention, as a light source of light containing energy higher than the band gap energy of the photocatalyst (a) or light absorbed by the sensitizing dye (D), for example, a light source in the environment such as sunlight, street light, night light, Furthermore, general lighting can be used. As general illumination, fluorescent lamps, incandescent lamps, metal halide lamps, black light lamps, xenon lamps, mercury lamps, LEDs, and the like can be suitably used.
When the surface treatment of the aluminum member is performed with the photocatalyst composition of the present invention, the amount of the modified photocatalyst (A) immobilized on the aluminum member is preferably 0.0001 g / m ² to the area of the aluminum member to be treated. was 100 g / ^{m 2,} more preferably ^{0.001g / m 2 ~10g / m 2} .

  As a method for immobilizing the photocatalyst composition on the member in the present invention, for example, after applying the photocatalyst composition to the member and drying it, it is preferably −20 ° C. to 500 ° C., more preferably 10 ° C. to 250 ° C. The method of performing the heat processing of this, ultraviolet irradiation, etc. can be mentioned. Examples of the application method include spraying, flow coating, roll coating, brush coating, dip coating, padding, casting, sponge coating, knife coating, gravure coating, and scribing. Examples of the method include a coat method, a sculpture roll coat method, and a flexo coat method.

Furthermore, the photocatalyst composition of the present invention uses the specific wax property of the modified photocatalyst (A) to be contained, a method of fixing while spreading on the member, a surplus amount with a cloth after being applied excessively on the member Thus, the modified photocatalyst (A) can be suitably immobilized on the member by the method of wiping off. At this time, the aluminum member may be washed and then treated with the photocatalyst composition, or the modified photocatalyst (A) may be fixed to the aluminum member while washing the member with the photocatalyst composition.
In the present invention, the immobilization state of the modified photocatalyst (A) in the photocatalytic aluminum member surface-treated with the photocatalyst composition may be a continuous film, a discontinuous film, an island-shaped dispersion film, or the like. I do not care.

  In the photocatalytic aluminum member of the present invention, the modified photocatalyst (A) may be directly fixed to a member made of aluminum or an aluminum alloy, but an anodized film is formed on the surface of the base material made of aluminum or aluminum alloy. Furthermore, it is preferable that the modified photocatalyst (A) is immobilized on the anodized film. The anodized film is an insulating film and has a microporous structure with irregularities with numerous pores having a diameter of about 5 nm to 200 nm opened on the surface. Therefore, the redox action of the photocatalyst with respect to the aluminum alloy metal is blocked to some extent by the insulating effect, and the adhesion of the photocatalyst-containing film of the present invention can be improved by the anchor effect by the microporous structure.

The aluminum member that can be used to obtain the photocatalytic aluminum member of the present invention can be subjected to surface treatment in advance for the purpose of adjusting the foundation, improving adhesion, sealing the porous base material, smoothing, and patterning. . Examples of the surface treatment include polishing, degreasing, plating treatment, chromate treatment, flame treatment, and coupling treatment.
The photocatalytic aluminum member provided by the present invention can be used very favorably as a building material.
For example, the photocatalytic aluminum member provided by the present invention and having a photocatalytic activity such as organic matter decomposition exhibits various functions such as antibacterial, antifouling, antifungal, deodorizing, NOx decomposition, etc. For example, building materials, building exteriors, building interiors, window frames, structural members, residential building equipment, lighting fixtures, lighting covers, kitchen utensils, tableware, sinks, etc. It can be used for kitchen hoods, doors, door knobs, exteriors and interiors of vehicles, medical and public facilities.

  Further, the photocatalytic member provided by the present invention, which has a hydrophilic contact angle with water at 20 ° C. of 30 ° or less (preferably 10 ° or less) by light irradiation, is suitable for interior and exterior of buildings, etc. It can be applied to antifouling technology, antistatic technology, and the like. For example, it can be used for building materials, building exteriors, building interiors, window frames, structural members, and building equipment such as houses.

The present invention will be specifically described by the following examples, reference examples and comparative examples. In Examples, Reference Examples and Comparative Examples, various physical properties were measured by the following methods.
1. Particle size distribution and number average particle size The sample was diluted with an appropriate solvent so that the photocatalyst content in the sample was 1 to 20% by mass, and measured using a wet particle size analyzer (Nikkiso Microtrac UPA-9230).

2. Weight average molecular weight It calculated | required by the gel permeation chromatography (GPC) using the analytical curve created using the polystyrene sample.
The conditions for GPC are as follows.
Apparatus: Tosoh HLC-8020 LC-3A type chromatography column: using connected _TSKgel G1000H _XL, TSKgelG2000H XL and TSKgel G4000H _XL (both manufactured by Tosoh Corp.) were connected serially.
Data processor: CR-4A type data processor manufactured by Shimadzu Corporation Mobile phase: Tetrahydrofuran Flow rate: 1.0 ml / min.
Sample preparation method: The sample was diluted with a solvent used for the mobile phase (concentration was appropriately adjusted in the range of 0.5 to 2% by weight) and subjected to analysis.

3. Infrared absorption spectrum The infrared absorption spectrum was measured using an FT / IR-5300 type infrared spectrometer manufactured by JASCO Corporation.
4). Wax properties (ease of spreading and wiping)
It carried out according to JIS K 2236.

5. Spreadability Evaluation was made according to the following procedure.
1) A sample containing 5% by mass of a modified photocatalyst weighed to 0.03 g was dropped onto a glass plate with a dropper.
2) The glass plate on which the sample was dropped was dried at 105 ° C. for 30 minutes, and then cooled at 23 ° C. and 55% humidity for 30 minutes.
3) Extend the dried modified photocatalyst with a plastic spatula, measure the length until the formed modified photocatalyst film starts to break, calculate the elongation (cm) per 0.01 g of the modified photocatalyst, and calculate this value. It was set as spreadability.

6). Contact angle of water A drop of deionized water was placed on the surface of the sample, left at 20 ° C. for 1 minute, and then measured using a CA-X150 contact angle meter manufactured by Kyowa Interface Science.
7). Antibacterial test A 5 cm x 1 cm sample was placed in a sterilized plastic dish, and a bacterial solution adjusted so that the number of E. coli bacteria was about 10 ⁵ cells / ml was added to each sample in each dish. 0.5 ml each was dropped, and the dish was covered with a polyethylene film to block it from the outside air, thereby preventing the bacterial solution on the specimen sample from drying and the entry of bacteria from the outside. Subsequently, after irradiating the light of the FL20SBLB type black light made by Toshiba Lighting & Technology from outside the petri dish for 4 hours, the bacterial solution was washed from the sample of the petri dish, transferred to the medium, and the number of viable bacteria was measured. Based on the calculated kill rate, antibacterial properties were evaluated in the following three stages.
Death rate = {(initial viable cell count−viable cell count after test) / initial viable cell count} × 100
○: Death rate of 80% or more Δ: Death rate of 20% or more and less than 80% ×: Death rate of less than 20% The UV intensity of Topcon UVR-2 type UV intensity meter {as the light receiving part, UD-36 type light receiving part made by Topcon (Corresponding to light having a wavelength of 310 to 400 nm)} was used to adjust the ultraviolet intensity measured to ² mW / cm ² .

8). Antifouling performance A sample cut into 5 cm x 1 cm is placed in a 120 ml glass bottle, filled with 5 cigarettes of smoke, and a sample of cigarette dust is attached to the sample. The sample was irradiated with light for 4 hours, and the antifouling performance was evaluated in the following three stages based on the appearance (visually evaluated) of the sample. At this time, the UV intensity measured using a Topcon UVR-2 type UV intensity meter {using a TOPCON UD-36 type light receiving part (corresponding to light with a wavelength of 310 to 400 nm) as the light receiving part} is ² mW / cm ^2. It adjusted so that it might become.
○: Coloring due to cigarette annihilation completely disappeared △: Coloring due to cigarette tinge lightened ×: No change in coloring due to cigarette crazing

9. Weather resistance (appearance)
An exposure test (irradiation: 60 ° C. for 4 hours, dark / wet: 40 ° C. for 4 hours) was performed using a DPWL-5R type dew panel light control weather meter manufactured by Suga Test Instruments. Based on the appearance (visual evaluation) of the sample after 1000 hours of exposure, the weather resistance was evaluated in the following three stages.
○: No change in appearance Δ: Whitening occurs ×: Photocatalyst-containing film peels off

[Reference Example 1]
Synthesis of modified photocatalytic hydrosol (A-1).
LS-8600 [trade name of 1,3,5,7-tetramethylcyclotetrasiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.)] 474 g, LS-8620 [Octamethyl] Trade name of cyclotetrasiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.)] 76.4 g, product name of LS-8490 [1,3,5-trimethyl-1,3,5-triphenylcyclotrisiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.) 408 g LS-7130 [trade name of hexamethyldisiloxane (manufactured by Shin-Etsu Chemical Co., Ltd.), 40.5 g, and sulfated zirconia 20 g were charged, stirred at 50 ° C. for 3 hours, and further stirred at 80 ° C. for 5 hours. . After filtering the sulfated zirconia, the low-boiling components were removed under vacuum at 130 ° C., and a methylhydrogensiloxane-methylphenylsiloxane-dimethylsiloxane copolymer (weight average molecular weight 6600, Si—H group content 7.93 mmol / g) ( 780 g of a synthetic silicone compound) was obtained.

Into a reactor equipped with a reflux condenser, a thermometer and a stirrer, 40 g of the synthetic silicone compound was put, 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, dehydrated methyl ethyl ketone 200 g, and chloroplatinic acid hexahydrate 5 mass% isopropanol solution 1 0.0 g of the mixed solution was added over about 1 hour with stirring, and the mixture was further stirred at 80 ° C. for 5 hours and then cooled to room temperature to obtain a Si—H group-containing compound solution (1). It was.
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 sodium hydroxide aqueous solution was added to generate hydrogen gas. 15.8 ml. The Si—H group content per 1 g of the Si—H group-containing compound solution (1) determined from this hydrogen gas production amount was 0.16 mmol / g (the Si—H group content calculated per 1 g of the synthetic silicone compound was about 1 .78 mmol / g).

To a reactor equipped with a reflux condenser, a thermometer and a stirrer, TKS-203 [trade name of titanium oxide hydrosol (manufactured by Teika), neutral, TiO ₂ concentration 19.2 mass%, average crystallite diameter 6 nm ( Catalog value)] After adding 252.0 g and 748.0 g of water, 61.1 g of the synthesized Si—H group-containing compound solution (1) was added to this at 40 ° C. with stirring over about 30 minutes. After further stirring at 40 ° C. for 12 hours, methyl ethyl ketone was removed by distillation under reduced pressure, and water was added to obtain 8.3% by mass of a highly-dispersible modified photocatalyst hydrosol (A-1). . At this time, the amount of hydrogen gas produced by the reaction of the Si—H group-containing compound solution (1) was 160 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 monodisperse (number average particle size is 75 nm), and further monodispersion of TKS203 before modification treatment (number average particle size is 12 nm). It was confirmed that the particle size distribution of was shifted to the larger particle size side.
The obtained modified photocatalyst hydrosol (A1) passed the tests of ease of spreading and wiping according to JIS K2236, and was confirmed to have a wax property. Also, the coating test was 380 cm, which was very good.

[Reference Example 2]
Synthesis of modified photocatalytic hydrosol (A-2).
A reactor equipped with a reflux condenser, a thermometer, and a stirrer was charged with 15 g of TSS4110 [trade name of visible light responsive titanium oxide sol (manufactured by Sumitomo Chemical Co., Ltd., photocatalyst concentration 10 mass%)] and 15 g of water. 2.9 g of the Si—H group-containing compound solution (1) synthesized in Reference Example 1 was added at 40 ° C. over about 30 minutes with stirring, and stirring was further continued at 40 ° C. for 12 hours, followed by vacuum distillation. Then, methyl ethyl ketone was removed and water was added to obtain a modified photocatalyst hydrosol (A-2) 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 19 ml at 20 ° C.
Moreover, the particle size distribution of the obtained modified photocatalyst hydrosol (A-2) is monodisperse (number average particle size is 21 nm), and further monodispersion of TSS4110 before modification (number average particle size is 13 nm). It was confirmed that the particle size distribution of was shifted to the larger particle size side.
The obtained modified photocatalyst hydrosol (A2) passed the tests of ease of spreading and wiping according to JIS K2236, and was confirmed to have a wax property. Also, the coating test was 320 cm, which was very good.

[Example 1]
10 g of the modified photocatalyst hydrosol (A1) synthesized in Reference Example 1 and 0.1 g of UNIOX M550 [trade name of polyoxyethylene monomethyl ether (manufactured by NOF Corporation), weight average molecular weight 550] and γ-aminopropyltriethoxysilane 1.5 g of a 1% by weight aqueous solution was added at room temperature with stirring, and stirring was continued for 1 hour. 88.5 g of a water-ethanol mixed solvent (water 53.1 g and ethanol 35.4 g) was stirred at room temperature. This was added to obtain a photocatalyst composition (C1). The photocatalyst composition (C1) passed the test for ease of spreading and wiping according to JISK 2236, and was confirmed to have a wax property.

By spraying the obtained photocatalyst composition (C1) onto a 10 cm × 10 cm aluminum plate on which an anodized film having a thickness of 10 μm is formed in a sulfuric acid electrolytic bath, drying at room temperature for 30 minutes, and then wiping with a towel A photocatalytic aluminum member (K1) was prepared.
The water contact angle of the obtained photocatalyst member (K1) was 10 °. Light of a FL20SBLB type black light manufactured by Toshiba Lighting & Technology (K1) on the photocatalyst member (K1) [Adjusted so that the UV intensity (UD-36 type light receiving part) measured using a UVR-2 type UV intensity meter manufactured by Topcon is ² mW / cm ² ] For 12 hours, the water contact angle was 100 °, and for 48 hours, the water contact angle was 3 °. The antibacterial property of the photocatalyzed aluminum member (K1) irradiated with this light was very good (◯). Furthermore, when the antifouling performance was evaluated, a very good result (◯) was obtained. Moreover, the appearance change in the weather resistance test of this photocatalytic aluminum member (K1) was very good (◯).

[Example 2]
The photocatalyst composition was obtained by performing the same operation as in Example 1 except that the modified photocatalyst hydrosol (A-1) obtained in Reference Example 1 was used instead of the modified photocatalyst hydrosol (A-1) obtained in Reference Example 2. (C2) was obtained. The photocatalyst composition (C2) passed the tests of ease of spreading and wiping according to JISK 2236, and was confirmed to be waxy.
The photocatalyst aluminum member (K2) was created by the process similar to Example 1 using the obtained photocatalyst composition (C2).
The water contact angle of the obtained photocatalyst member (K2) was 8 °. UV light shielding fluorescent lamp (Neoline Deluxe FL20S-N-SDL / NU / manufactured by Toshiba Lighting & Technology Corp.) [UV intensity measured with Topcon UVR-2 UV intensity meter] (UD-36 type light receiving unit) is 0.2~0.3μW / cm ^2, so that the visible light intensity measured using the same UV intensity meter (UD-40 type light receiving unit) is 750~800μW / cm ² When adjusted for 24 hours, the water contact angle was 100 °, and when further irradiated for 120 hours, the water contact angle was 14 °. The antibacterial property of the photocatalytic aluminum member (K2) irradiated with the ultraviolet shielding fluorescent lamp was very good (◯). Furthermore, when the antifouling performance was evaluated, a very good result (◯) was obtained. Moreover, the appearance change in the weather resistance test of this photocatalytic aluminum member (K2) was very good (◯).

[Example 3]
The photocatalyst composition (C3) was obtained by adding 1.0 g of 0.1 mass% aqueous solution of eosin Y as a sensitizing dye to the photocatalyst composition (C1) prepared in Example 1 at room temperature with stirring. The photocatalyst composition (C3) passed the tests of ease of spreading and wiping according to JISK 2236, and was confirmed to have a wax property.
The photocatalyst aluminum member (K3) was created by the process similar to Example 1 using the obtained photocatalyst composition (C3).
The water contact angle of the obtained photocatalyst member (K3) was 11 °. UV light shielding fluorescent lamp (Neoline Deluxe FL20S-N-SDL / NU / manufactured by Toshiba Lighting & Technology Corp.) [UV intensity measured with Topcon UVR-2 UV intensity meter] (UD-36 type light receiving unit) is 0.2~0.3μW / cm ^2, so that the visible light intensity measured using the same UV intensity meter (UD-40 type light receiving unit) is 750~800μW / cm ² When adjusted for 24 hours, the water contact angle was 105 °, and after 72 hours, the water contact angle was 10 °. The antibacterial property of the photocatalytic aluminum member (K3) irradiated with the ultraviolet shielding fluorescent lamp was very good (◯). Furthermore, when the antifouling performance was evaluated, a very good result (◯) was obtained. Moreover, the appearance change in the weather resistance test of this photocatalytic aluminum member (K3) was very good (◯).

[Comparative Example 1]
Instead of the modified photocatalyst hydrosol (A-1) obtained in Reference Example 1, the same operation as in Example 1 was carried out except that TKS203 (same as Reference Example 1) was diluted with water to 5% by mass. Thus, a photocatalyst composition (C4) was obtained. The photocatalyst composition (C4) did not pass the test for ease of spreading and wiping in JISK 2236.
Although the photocatalyst composition (C4) obtained was sprayed on a 10 cm × 10 cm aluminum plate on which an anodized film having a thickness of 10 μm was formed in a sulfuric acid electrolytic bath, dried at room temperature for 30 minutes, and then wiped with a towel. It was impossible.

  The photocatalytic aluminum member of the present invention can be used for applications such as environmental purification, antibacterial, and antifouling in living spaces, and can be widely used particularly as a functional building material.

Claims (11)

The photocatalyst (a) is surface-treated with a photocatalyst composition (C) containing a modified photocatalyst (A) having a wax property that has been modified using the modifier compound (b) represented by the formula (1). Photocatalytic aluminum member.
_{R x X y Q z SiO (} 4-x-y-z) / 2 (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 number having 1 to 30 carbon atoms. It represents a group consisting of one or more selected from a fluoroalkyl group, a linear or branched alkenyl group having 2 to 30 carbon atoms, and a phenyl group.
Q represents a C1-C30 organic group containing a group represented by the following formula (2) or a group represented by the following formula (2).
— (O) _a R ¹ O (R ² O) _b R ³ (2)
(Wherein R ¹ and R ² each independently represents a linear or branched alkylene group having 1 to 10 carbon atoms. R ³ represents a hydrogen atom, a linear or branched carbon group having 1 to 30 carbon atoms. An alkyl group, a cycloalkyl group having 5 to 20 carbon atoms, or a linear or branched alkenyl group having 2 to 30 carbon atoms and a phenyl group, a is 0 or 1, and b is an integer of 1 to 100 Represents.)
X represents each independently 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, an oxime group having 1 to 20 carbon atoms, or a halogen atom. Further, 0 ≦ x <4, 0 ≦ y <4, 0 <z <4, and 0 <(x + y + z) <4. )   The photocatalytic aluminum member according to claim 1, wherein the photocatalytic composition (C) contains a sensitizing dye (D).   The photocatalytic aluminum member according to claim 1 or 2, wherein the photocatalytic composition (C) contains water and / or alcohol.   The photocatalytic aluminum member according to any one of claims 1 to 3, wherein the photocatalytic composition (C) contains an amino group-containing silane coupling agent.   The photocatalytic aluminum member according to any one of claims 1 to 4, wherein the photocatalytic composition (C) contains a surfactant.   A photocatalytic aluminum member having a wax property and surface-treated with the photocatalyst composition (C) according to any one of claims 1 to 5.   2. The photocatalytic aluminum member according to claim 1, which exhibits photocatalytic activity and / or hydrophilicity when irradiated with light having energy higher than the band gap energy of the contained photocatalyst (a).   The photocatalytic activity and / or hydrophilicity is exhibited by irradiating light having an energy higher than the band gap energy of the absorbed light of the contained sensitizing dye and / or the contained photocatalyst (a). The photocatalytic aluminum member described in 1.   The photocatalytic aluminum member according to claim 7 or 8, which has antifouling performance.   The photocatalytic aluminum member according to claim 7 or 8, which has antibacterial performance.   A surface treatment method for an aluminum member, wherein the photocatalyst composition (C) according to any one of claims 1 to 6 is applied to the aluminum member and then spread.