Structure carrying photocatalyst

The present invention relates to a structure carrying a photocatalyst used for water purification, deodorization, antifouling, sterilization, wastewater treatment, algae growth suppression, various chemical reactions, etc., and has sufficient durability even in an outdoor environment having excellent transparency. The present invention relates to a photocatalyst-supporting structure having the above, and a coating liquid for forming an adhesive layer.

Conventionally, a photocatalyst-supporting structure in which a photocatalyst is supported on a carrier (base material or substrate) is known with the intention of antibacterial, antifungal properties, and decomposition of harmful substances by the action of the photocatalyst. Such a photocatalyst-supporting structure is usually produced by forming a photocatalyst layer by applying a photocatalyst layer-forming coating liquid containing a photocatalyst component on a carrier surface and curing it.

However, when a photocatalyst layer (a film or layer containing a photocatalyst) is formed directly on the carrier, problems such as deterioration and discoloration of the carrier due to the strong oxidizing action of the photocatalyst and problems such as peeling of the photocatalyst layer from the carrier occur. There was a risk. Therefore, a photocatalyst structure having a binder layer (persistent intermediate layer: adhesive layer) between the carrier and the photocatalyst layer is known (Patent Document 1, Patent Document 2, Patent Document 3, Patent Document 4). , Patent Document 5, Patent Document 6). Silica sol has been widely used as such a binder layer.

However, when such a photocatalyst-supporting structure is used outdoors, it is exposed to changes in the environment such as temperature and humidity for a long period of time, and there is a problem that the transparency of the binder layer and the photocatalyst layer deteriorates. In particular, in the case of a structure in which the transparency of the carrier and the color and pattern of the carrier are important, deterioration of the transparency of the binder layer and the photocatalyst layer has been a big problem.

On the other hand, in Patent Document 7, the elastic modulus of the resin member is improved and the coefficient of thermal expansion is reduced by adding a silica composition obtained by modifying the surface of fine particle silica such as granular or chain silica to the resin monomer. It discloses that it can be done. However, it has not been known that the transparency of the photocatalyst layer for photocatalyst and the adhesive layer can be maintained for a longer period of time by using silica bonded in an elongated shape as chain silica or the like.

<patcit num="1"><text>Japanese Patent Application Laid-Open No. 2005-137977</text></patcit><patcit num="2"><text>Japanese Unexamined Patent Publication No. 2004-351365</text></patcit><patcit num="3"><text>Japanese Unexamined Patent Publication No. 8-131842</text></patcit><patcit num="4"><text>Japanese Unexamined Patent Publication No. 2005-61156</text></patcit><patcit num="5"><text>Japanese Unexamined Patent Publication No. 10-278168</text></patcit><patcit num="6"><text>WO2003-0331 44 Pamphlet</text></patcit><patcit num="7"><text>Japanese Unexamined Patent Publication No. 2003-286306</text></patcit>

<p> An object of the present invention is a structure in which a photocatalyst layer, an adhesive layer and a carrier are provided, and an adhesive layer and a photocatalyst layer are sequentially provided on the carrier, and the transparency of the photocatalyst layer and the adhesive layer is maintained for a longer period of time. It is an object of the present invention to provide a photocatalyst-supporting structure.</p>

<p> The present inventors have made the transparency of the photocatalyst layer and the adhesive layer more transparent by utilizing silica bonded in an elongated shape, particularly a conjugate of spherical colloidal silica particles, rod-shaped colloidal silica, or a mixture thereof for the adhesive layer. We have found that it is retained for a long period of time, and have completed the present invention.</p><p> That is, the present invention is a structure in which (1) a photocatalyst layer, an adhesive layer, and a carrier are provided, and an adhesive layer and a photocatalyst layer are sequentially provided on the carrier, and the adhesive layer contains silica bonded in an elongated shape. A photocatalyst-supported structure characterized by the fact that (2) silica bonded in an elongated shape is applied to the adhesive layer.The photocatalyst-supported structure according to (1) above, which is characterized by containing 1 to 60% by weight, and (3) silica bonded in an elongated shape are a conjugate of spherical colloidal silica particles, rod-shaped colloidal silica, or them. The photocatalyst-supported structure according to (1) or (2) above, which is a mixture of the above, and (4) the particle size of spherical colloidal silica particles is in the range of 10 to 50 nm. The photocatalyst-supported structure according to (3) or (4) above, wherein the photocatalyst-supported structure described in 3) and the conjugate of (5) spherical colloidal silica particles are linked with three or more colloidal silicas. The structure and the conjugate of (6) spherical colloidal silica particles are characterized in that the length of the short side thereof is in the range of 10 to 50 nm and the length of the long side thereof is in the range of 50 to 400 nm. The photocatalyst-supported structure according to any one of (3) to (5) above and (7) rod-shaped colloidal silica have a short side length in the range of 10 to 50 nm and a long side length of 50. The photocatalyst-supported structure according to any one of (3) to (6) above, which is characterized in the range of ~ 400 nm, and (8) silica bonded in an elongated shape are measured by the dynamic photoconfusion method. The ratio D1 / D2 of (D1) and the particle size (D2) measured by the nitrogen gas adsorption method is 5 or more, and this D1 is 40 to 300 nm, and the thickness is within the range of 5 to 20 nm and only in one plane. From the group consisting of the photocatalyst-supported structure according to any one of (1) to (7) above, which is an amorphous colloidal silica having the elongation of (9) a zirconium compound, an aluminum compound, and a silicon compound. The photocatalyst-supported structure according to any one of (1) to (8) above, or the zirconium compound (10), which further contains at least one selected kind in a portion other than the carrier, oxidizes zirconium. One or a mixture of two or more selected from the group consisting of substances, oxide hydroxides, hydroxides, oxynitrates, oxycarbonates, alkoxides having 1 to 4 carbon atoms, and hydrolysates of the alkoxides. The present invention relates to the photocatalyst-supported structure according to (9) above.Oxide, oxide hydroxide, hydroxide, oxynitrate, oxycarbonate, alkoxide having 1 to 4 carbon atoms, and one or a mixture of two or more selected from the group consisting of a hydrolyzate of the alkoxide. The present invention relates to the photocatalyst-supporting structure according to (9) above.Oxide, oxide hydroxide, hydroxide, oxynitrate, oxycarbonate, alkoxide having 1 to 4 carbon atoms, and one or a mixture of two or more selected from the group consisting of a hydrolyzate of the alkoxide. The present invention relates to the photocatalyst-supporting structure according to (9) above.</p><p> Further, in the present invention, the (11) aluminum compound comprises an aluminum oxide, an oxide hydroxide, a hydroxide, an oxynitrate, an oxycarbonate, an alkoxide having 1 to 4 carbon atoms, and a hydrolyzate of the alkoxide. The photocatalyst-supporting structure according to (9) or (10) above, which is one or a mixture of two or more selected from the group, and (12) a silicon compound are silicon resins, polysiloxanes, and alkoxides. The photocatalyst-supporting structure according to any one of (9) to (11) above, and (13) a zirconium compound and / or an aluminum compound, which is characterized in that it is at least one selected from the group consisting of silica, is 150. Specific surface area after drying at ° C is 100 m²The photocatalyst-supported structure according to any one of (9) to (12) above, which is characterized by being in the form of a porous gel of / g or more, and the (14) photocatalyst layer are converted into oxides and are zirconium compounds. 5 to 60% by weight, 20 to 90% by weight of an aluminum compound, 5 to 60% by weight of titanium oxide, and 5 to 50% by weight of a silicon compound. The photocatalyst-supported structure according to any one of (1) to (14) above, which further contains (15) silica bonded in an elongated shape in the photocatalyst layer. (16) The photocatalyst-supported structure according to any one of (1) to (15) above, wherein the haze rate of the coating film including the photocatalyst layer and the adhesive layer is 3% or less, or (17) boiling. The photocatalyst-supported structure according to (16) above, wherein the haze rate of the coating film including the photocatalyst layer and the adhesive layer after boiling in ion-exchanged water for 1 hour is 3% or less, or (18). ) The photocatalyst-supported structure according to any one of (1) to (17) above, wherein the carrier is for an outer wall.</p><p> Further, the present invention is (19) a coating liquid used for forming an adhesive layer in a photocatalyst-supporting structure, which comprises silica bonded in an elongated shape, and a coating liquid for forming an adhesive layer. (20) Silica bonded to an elongated shape is used as a solid content in terms of oxides of 0.01 to 12.The coating liquid for forming an adhesive layer according to (19) above, which is characterized by containing 0% by weight, and (21) silica bonded in an elongated shape are a conjugate of spherical colloidal silica particles, rod-shaped colloidal silica, or a rod-shaped colloidal silica thereof. The coating liquid for forming an adhesive layer according to the above (19) or (20), which is a mixture, and (22) the spherical colloidal silica particles, which are characterized in that the particle size is in the range of 10 to 50 nm. The above-mentioned (21) or (22), wherein the coating liquid for forming an adhesive layer according to (21) or a conjugate of (23) spherical colloidal silica particles is a conjugate of three or more colloidal silicas. The above-mentioned coating liquid for forming an adhesive layer and (24) a conjugate of spherical colloidal silica particles have a short side length in the range of 10 to 50 nm and a long side length in the range of 50 to 400 nm. The coating liquid for forming an adhesive layer according to any one of (21) to (23) described above and (25) rod-shaped colloidal silica have a short side length in the range of 10 to 50 nm. The coating liquid for forming an adhesive layer according to any one of (21) to (24) above, which is characterized in that the length of its long side is in the range of 50 to 400 nm, and (26) silica bonded to an elongated shape. The ratio of the particle size (D1) measured by the dynamic photoconfusion method to the particle size (D2) measured by the nitrogen gas adsorption method is 5 or more, and this D1 is 40 to 300 nm, which is 5 to 20 nm. The coating liquid for forming an adhesive layer according to any one of (19) to (25) above, which is an amorphous colloidal silica having a thickness within the range and extending only in one plane, or (27). At least one of the resins selected from the group consisting of a silicon-modified resin containing 2 to 60% by weight of silicon, a resin containing 5 to 40% by weight of colloidal silica, and a resin containing 3 to 60% by weight of polysiloxane. Further contains the coating liquid for forming an adhesive layer according to any one of (19) to (26) above, (28) acrylic-silicon resin, silicon-modified resin containing polysiloxane, and colloidal silica. Silicon-modified resin selected from the group consisting of silicon-modified resinsThe coating liquid for forming an adhesive layer according to any one of (19) to (26) above, which further contains at least one of the above.</p>

<p> In the photocatalyst-supporting structure including the photocatalyst layer, the adhesive layer and the carrier of the present invention, the transparency of the photocatalyst layer and the adhesive layer is maintained for a longer period of time.</p>

The photocatalyst-supporting structure of the present invention is a photocatalyst-supporting structure provided with a photocatalyst layer, an adhesive layer, and a carrier, and an adhesive layer and a photocatalyst layer are sequentially provided on the carrier. It is characterized by containing silica. The photocatalyst-supporting structure of the present invention includes a photocatalyst layer, an adhesive layer, and a carrier, and as long as the adhesive layer and the photocatalyst layer are sequentially provided on the carrier, other configurations are further provided in other portions. You may be doing it. Other configurations are not particularly limited, but for example, a coating layer further existing on the photocatalyst layer, an intermediate layer further existing between the photocatalyst layer and the adhesive layer, a printing layer further existing between the adhesive layer and the carrier, and the like. And so on.

The adhesive layer in the present invention is not particularly limited as long as it contains silica bonded in an elongated shape. By providing such an adhesive layer between the photocatalyst layer and the carrier, it is possible to prevent the underlying carrier from being deteriorated by the photocatalytic action of the photocatalyst in the photocatalyst layer, and the photocatalyst layer is more firmly adhered to the carrier. In addition, the transparency of the photocatalyst layer and the adhesive layer can be maintained for a long period of time.

In the present invention, the silica bonded to the elongated shape includes, for example, one in which spherical silica particles are connected to form an elongated shape, rod-shaped silica itself, or a mixture thereof, and among them, spherical colloidal silica particles. The conjugates, rod-shaped colloidal silica, or mixtures thereof are preferred from the standpoint of longer retention of the transparency of the photocatalyst layer and the adhesive layer.

The conjugate of the spherical colloidal silica particles of the present invention means a conjugate of spherical colloidal silica particles. Here, the "spherical colloidal silica particles" mean colloidal silica particles having a particle size in the range of 1 to 1000 nm, preferably 1 to 100 nm, and more preferably 10 to 50 nm. Further, the spherical colloidal silica particles in the present invention are not limited to the spherical shape in a strict sense, and include shapes having different major and minor diameters such as capsule shape and rugby ball shape. In the present invention, the fact that the colloidal silica particles are connected means that the colloidal silica particles are bonded to each other. Bonding here does not matter whether it is direct or indirect.

Examples of the conjugate of the spherical colloidal silica particles in the present invention include those in which three or more spherical colloidal silica particles are linked. In addition, the length of the short side of the spherical colloidal silica particles is in the range of 10 to 50 nm, and the length of the long side is in the range of 50 to 400 nm for the photocatalyst layer and adhesion. It is preferable from the viewpoint of long-term retention of the transparency of the layer. Here, the short side of the connected product of the spherical colloidal silica particles means the particle size or the minor axis of the spherical colloidal silica particles having the smallest particle size among the connected spherical colloidal silica particles, and the spherical colloidal silica particles. The long side of the conjugate of the spherical colloidal silica particles means the longest side of the conjugate of the spherical colloidal silica particles. Further, among the connected products of the spherical colloidal silica particles in the present invention, the photocatalyst is one in which another spherical colloidal silica particles are connected in a two-dimensional direction (in one plane) starting from one spherical colloidal silica particles. It is preferable from the viewpoint of long-term retention of the transparency of the layer or the adhesive layer.

The particle size or minority of the spherical colloidal silica particles in the conjugate of the spherical colloidal silica particles may be different, but from the viewpoint of longer-term retention of transparency, the largest particle size and the smallest particle size. The difference between the two, or the difference between the largest minor axis and the smallest minor axis, is preferably included in the range of 20 nm, and preferably included in the range of 10 nm. The shape of the conjugate of the spherical colloidal silica particles in the present invention is not particularly limited, and may be a linear shape, a branched shape, a bent shape or the like.

The rod-shaped colloidal silica in the present invention means colloidal silica in which the length of the long side is at least twice or more the length of the short side. Here, the short side of the rod-shaped colloidal silica means the diameter of the thinnest portion of the rod-shaped colloidal silica, and the long side means the longest side of the rod-shaped colloidal silica. In addition, rod-shaped colloidal silica has a short side length in the range of 10 to 50 nm and a long side length in the range of 50 to 400 nm over a longer period of transparency of the photocatalyst layer and the adhesive layer. It is preferable from the viewpoint of retention.

The thickness of the rod-shaped colloidal silica in the present invention does not have to be equal throughout, but the difference between the diameter of the thickest part and the diameter of the thinnest part from the viewpoint of long-term retention of the transparency of the photocatalyst layer and the adhesive layer. Is preferably contained in the range of 20 nm, and is preferably contained in the range of 10 nm. The shape of the rod-shaped colloidal silica in the present invention is not particularly limited, and a shape including a rod-shaped colloidal silica as a part is also included. For example, rod-shaped colloidal silica and spherical colloidal silica may be connected, rod-shaped colloidal silica may be branched, or may be bent.

When the conjugate of spherical colloidal silica particles or rod-shaped colloidal silica has a bent shape, the diameters of the longest side and the thinnest portion are measured based on the linearly stretched state. When the conjugate of spherical colloidal silica particles or rod-shaped colloidal silica is branched, the diameters of the longest side and the thinnest part are measured based on the state in which the longest side is the longest.

Specifically, as the silica bonded to the elongated shape in the present invention, the ratio D1 / D2 of the particle size (D1) measured by the dynamic light scattering method and the particle size (D2) measured by the nitrogen gas adsorption method is 5 or more. Thus, this D1 is 40-300 nm, and an elongated form of amorphous colloidal silica with a thickness in the range of 5-20 nm as observed by electron microscopy and elongation only in one plane can be exemplified. As a method for producing such a sol in which colloidal silica is dispersed, the methods described in JP-A-1-317115 and JP-A-7-118008 can be exemplified.

The content of silica bonded to the elongated shape contained in the adhesive layer in the present invention is not particularly limited as long as the effect of the present invention that the transparency of the photocatalyst layer and the adhesive layer is maintained for a long period of time can be obtained, but the adhesive layer is not particularly limited. On the other hand, it is preferably 0.1 to 60% by weight, more preferably 1 to 30% by weight, and even more preferably 1 to 15% by weight in terms of oxide.

The adhesive layer in the present invention preferably contains a resin in addition to silica bonded in an elongated shape because it provides better adhesive strength and a deterioration-preventing effect due to photocatalytic action, and silica bonded in an elongated shape is preferable. It is more preferable that the resin is substantially uniformly compounded. The content of the resin in the adhesive layer in the present invention is not particularly limited, but the solid content is preferably 30 to 90% by weight, more preferably 60 to 80% by weight, based on the total amount of the adhesive layer.

Such a resin is not particularly limited as long as it can protect the carrier from deterioration due to photocatalytic action and further fix the photocatalyst layer. For example, (1) the silicon content is converted into an oxide as a solid substance. 2 to 60% by weight of silicon-modified resin (acrylic-silicon resin, epoxy silicon resin, polyester silicon resin, etc.), (2) Resin containing 3 to 60% by weight of polysiloxane as a solid in terms of oxide (poly) It is preferable to use (3) a silicon-modified resin containing siloxane) or (3) a resin containing 5 to 40% by weight of colloidal silica as a solid in terms of oxide (silicon-modified resin containing colloidal silica). it can. These resins can firmly bond the photocatalyst and protect the carrier from the photocatalyst.

When silicon, polysiloxane or colloidal silica is contained in the above range, the adhesive force to the photocatalyst layer and the adhesion to the carrier are well balanced.

The resin into which silicon is introduced is not particularly limited, and examples thereof include acrylic resin, epoxy resin, polyester resin, alkyd resin, and urethane resin. Of these, an acrylic resin, an epoxy resin, and a polyester resin are particularly preferable in terms of film forming property, toughness, and adhesion to a carrier. These resins can be used in either solution form or emulsion type. Further, these resins may contain additives such as a cross-linking agent.

When the resin of the adhesive layer contains polysiloxane, it is better if the polysiloxane is a hydrolyzate of silicon alkoxide having an alkoxy group having 1 to 5 carbon atoms or a product of the hydrolyzane. And durability is obtained, which is preferable. It is also possible to use a polysiloxane obtained by hydrolyzing a silicon alkoxide partially containing chlorine.

As such a silicon alkoxide, for example, a silicon alkoxide represented by the formula (IV) described later or a hydrolysis product thereof can be preferably used. A preferable specific example of the silicon alkoxide represented by the formula (IV) is Si (OCH).₃)₄, Si (OC₂H₅)₄, Si (OC₃H₇)₄, Si (OC₄H₉)₄, Si (OC₅H₁₁)₄, Si (OC₆H₁₃)₄, SiC H₃(OCH₃)₃, SiC H₃(OC₂H₅)₃, SiC H₃(OC₃H₇)₃, SiC H₃(OC₃H₇)₃, SiC H₃(OC₄H₉)₃, SiCl (OCH)₃)₃, SiCl (OC)₂H₅)₃, SiCl (OC)₃H₇)₃, SiCl (OC)₄H₉)₃, SiCl (OC)₆H₁₃)₃, SiCl (OH) (OCH₃)₂, SiCl (OH) (OC₂H₅)₂, SiCl (OH) (OC₃H₇)₂, SiCl (OH) (OC₄H₉)₂, SiCl₂(OCH₃)₂, SiCl₂(OC₂H₅)₂And so on.

The method for introducing silicon into these silicon-modified resins is not particularly limited. Examples of such a method include a transesterification reaction, a graft reaction using a silicon macromer or a reactive silicon monomer, a hydrosilylation reaction, a block copolymerization method and the like. For example, as a more specific method for introducing polysiloxane into a resin, (1) a method in which silicon alkoxide is mixed with a resin solution in the form of a monomer and hydrolyzed with water in the air when an adhesive layer is formed, (2). ) Examples thereof include a method in which a partial hydrolyzate of silicon alkoxide is mixed with a resin in advance, and further hydrolyzed with moisture in the air when an adhesive layer is formed. In addition, in order to adjust the hydrolysis rate of silicon alkoxide, a small amount of acid or base catalyst may be added. The amount of the polysiloxane added to the resin is preferably 3 to 90% by weight in terms of oxide with respect to the total amount of the resin from the viewpoint of more firmly adhering the photocatalyst layer to the carrier.

The resin into which the polysiloxane is introduced is not particularly limited, and examples thereof include acrylic resin, epoxy resin, polyester resin, urethane resin, and alkyd resin. Of these, it is preferable to use an acrylic resin, an epoxy resin, a polyester resin, or a mixed resin thereof because excellent durability can be obtained when polysiloxane is introduced.

When the resin used for the adhesive layer is a resin containing colloidal silica, the particle size of colloidal silica is not particularly limited, but the particle size is 50 nm or less from the viewpoint of durability against photocatalytic action and adhesion to the photocatalytic layer. Is preferable. The method of introducing colloidal silica into the resin is not particularly limited, but one of the simplest methods is to mix the resin solution and the colloidal silica solution, and then apply-dry to form a protective film. In addition, colloidal silica A method of polymerizing the resin in a dispersed state can also be mentioned. Further, in order to improve the adhesiveness and dispersibility between the colloidal silica and the resin, colloidal silica treated with a silane coupling agent can also be used. The amount of colloidal silica added to the resin is preferably 5 to 90% by weight in terms of oxide with respect to the total amount of the resin from the viewpoint of more firmly adhering the photocatalyst layer to the carrier.

The resin into which colloidal silica is introduced is not particularly limited, and examples thereof include acrylic resin, epoxy resin, urethane resin, polyester resin, and alkyd resin. Of these, acrylic resin, epoxy resin, and polyester resin are preferable because excellent durability can be obtained when colloidal silica is introduced. The method for producing colloidal silica is not particularly limited, and examples thereof include a method of cation exchange of an aqueous sodium silicate solution and a method of hydrolyzing silicon alkoxide.

Further, in the present invention, a resin containing both polysiloxane and colloidal silica can be used as the adhesive layer. In that case, the total amount of polysiloxane and colloidal silica added to the resin may be 5 to 90% by weight in terms of oxide with respect to the total amount of the resin, because better adhesive strength can be obtained. preferable.

When the resin used for the adhesive layer is a resin containing colloidal silica and / or a resin containing polysiloxane, the particle size of the colloidal silica or polysiloxane is not particularly limited, but it has better dispersibility and transparency of the adhesive layer. Since light property can be obtained, it is desirable that each is 50 nm or less.

A light stabilizer and / or an ultraviolet absorber can be further added to the adhesive layer resin for the purpose of suppressing deterioration due to photocatalytic action. The light stabilizer is not particularly limited, but a hindered amine-based light stabilizer can be preferably used. The ultraviolet absorber is not particularly limited, but a triazole-based ultraviolet absorber or the like can be used. The amount of the light stabilizer and the ultraviolet absorber added is not particularly limited, but can be preferably 0.005% by weight to 10% by weight, more preferably 0.01% by weight to 5% by weight, respectively, with respect to the adhesive layer resin. ..

Further, by treating the surface of the adhesive layer on the side in contact with the photocatalyst layer with, for example, a silane-based or titanium-based coupling agent, the adhesiveness with the photocatalyst layer can be enhanced.

The method for forming the adhesive layer on the surface of the carrier is not particularly limited, and for example, a coating method for forming an adhesive layer, which will be described later, is applied to the carrier by a method such as a printing method, a sheet forming method, a spray spraying method, a dip coating method, or a spin coating method. A method of coating the surface and drying / curing can be exemplified. The temperature at the time of drying and curing varies depending on the type of solvent and resin, but is generally preferably about 50 ° C to 300 ° C.

The thickness of the adhesive layer is not particularly limited, but it is preferably about 0.1 μm to 20 μm in order to obtain good adhesion to the photocatalyst layer. If the thickness of the adhesive layer is too thin, the adhesive force to the photocatalyst layer may not be sufficient, but if it is too thick, there is little merit.

The photocatalyst in the present invention is not particularly limited as long as it contains a substance having photocatalytic activity (hereinafter, referred to as "photocatalyst"). As a photocatalyst, specifically TiO₂, ZnO, SrTiO₃, CdS, GaP, InP, GaAs, BaTiO₃, KNbO₃, Fe₂O₃, Ta₂O₅, WO₃, SnO₂, Bi₂O₃, NiO, Cu₂O, SiC, SiO₂, MoS₂, InPb, RuO₂, CeO₂Etc. can be exemplified, and Pt, Rh, RuO can be further added to these photocatalysts.₂, Nb, Cu, Sn, Ni, Fe and other metals or metal oxides added can be used. Of these, titanium oxide (TiO) is considered in consideration of durability, cost, and photocatalytic activity.₂) Is particularly preferable, and anatase-type titanium oxide is more preferable in consideration of photocatalytic activity. Further, not only titanium oxide that exhibits catalytic activity with light containing a large amount of ultraviolet rays such as sunlight, but also titanium oxide that exhibits catalytic activity even in indoor light having less ultraviolet rays by doping with a noble metal or the like can be used. The photocatalyst layer of the present invention may contain only one type of photocatalyst, but may contain two or more types of photocatalyst.

Further, the photocatalyst layer of the present invention is selected from the group consisting of a zirconium compound, an aluminum compound and a silicon compound in addition to the photocatalyst from the viewpoint of improving the adhesiveness with the adhesive layer and maintaining the transparency for a longer period of time. It is preferable to contain at least one of these.

Any photocatalyst can be used, such as powder, sol, and solution, as long as it adheres to the adhesive layer and exhibits photocatalytic activity when dried and cured. In particular, if a sol-like material having a particle size of 50 nm or less, preferably 20 nm or less is used, the transparency of the photocatalyst layer is improved and the parallel light transmittance is increased. It is preferable when applying. Further, when a carrier having a color or pattern is used, it is preferable to use such a transparent photocatalyst layer because the color and pattern of the base are not impaired. When a photocatalyst having a particle size of 50 nm or more is used, the parallel light transmittance is reduced and the haze rate is increased as compared with the case where a photocatalyst having a particle size of 50 nm or less is used. Here, the haze rate is a value obtained by the relational expression of haze rate = (total light transmittance-parallel light transmittance) × 100 / total light transmittance. For example, the window glass of a toilet has a high total light transmittance so that the inside of the toilet can be brightened by sufficiently transmitting the outside sunlight, and the inside of the toilet must not be clearly visible from the outside. The rate needs to be high.

The total content of the photocatalyst in the photocatalyst layer is preferably 0.1 to 60% by weight, more preferably 10 to 40% by weight, in terms of oxide, with respect to the photocatalyst layer. Further, when the photocatalyst is titanium oxide, the same range is mentioned as a preferable range. When used in such a range, a well-balanced photocatalytic layer can be obtained from the viewpoint of adhesiveness to the adhesive layer and photocatalytic activity. When the photocatalyst layer of the present invention contains a zirconium compound, the content of the zirconium compound is preferably 5 to 60% by weight, more preferably 10 to 30% by weight, based on the photocatalyst layer. When the photocatalyst layer of the present invention contains an aluminum compound, the content of the aluminum compound is preferably 20 to 90% by weight, more preferably 20 to 40% by weight, based on the photocatalyst layer. When the photocatalyst layer of the present invention contains a silicon compound, the content of the silicon compound is preferably 5 to 50% by weight, more preferably 20 to 40% by weight, based on the photocatalyst layer. Within these ranges, a well-balanced photocatalyst layer can be obtained from the viewpoint of adhesiveness to the adhesive layer and long-term retention of transparency. When the photocatalyst layer contains any two or more compounds selected from the group consisting of a zirconium compound, an aluminum compound and a silicon compound, the total of these compounds is preferably 40 to 40 to the photocatalyst layer. 95% by weight, more preferably 60 to 90% by weight. Within these ranges, a well-balanced photocatalytic layer can be obtained from the viewpoints of adhesiveness to the adhesive layer, long-term retention of transparency, and photocatalytic activity.

The zirconium compound is not particularly limited, but zirconium oxide, oxide hydroxide, hydroxide, nitrate, oxynitrate, carbonate, oxycarbonate, oxalate, oxyhydrate, acetate, oxyacetate, A gel of one or a mixture of two or more selected from the group consisting of alkoxides having 1 to 6 carbon atoms and hydrolysis products of the alkoxides is preferable, and zirconium oxide, zirconium oxynitrate, zirconium oxychloride, zirconium hydrated zirconium oxide , Zirconium oxyhydroxide, hydrated zirconium nitrate, hydrated zirconium oxychloride, zirconium oxalate, zirconium acetate, zirconium tetraisopropoxide, zirconium tetrabutoxide, zirconium dibutoxide acetylacetonate, zirconium dibutoxide lactoate, hydrolysis of zirconium butoxide The product, a hydrolysis product of zirconium isopropoxide, is particularly preferred.

The aluminum compound is not particularly limited, but is limited to aluminum oxides, oxide hydroxides, hydroxides, nitrates, oxynitrates, carbonates, oxycarbonates, oxalates, oxyhydrates, acetates, oxyacetates, etc. One or a mixture of two or more selected from the group consisting of alkoxides having 1 to 6 carbon atoms and hydrolysis products of the alkoxides is preferable, and aluminum oxide, aluminum oxide hydroxide, aluminum hydroxide, and hydrated aluminum oxide are preferable. , Boehmite, aluminum nitrate, aluminum oxynitrate, aluminum carbonate, aluminum oxycarbonate, aluminum oxalate, aluminum oxychloride, aluminum acetate, aluminum oxyacetate, aluminum triisopropoxide, aluminum tributoxide, aluminum butoxide acetylacetonate, aluminum butoxide lactoate , Aluminum butoxide hydrolysis products, aluminum isopropoxide hydrolysis products and the like are particularly preferred.

The particle size of the zirconium compound and the aluminum compound in the present invention is not particularly limited, but it is preferable to use a sol having a particle size of 2 nm to 50 nm, preferably 2 nm to 20 nm. When a photocatalyst layer having such a particle size is used, the transparency of the photocatalyst layer is improved and the parallel light transmittance is increased, which is preferable when the photocatalyst layer is applied to a glass substrate or a plastic molded body which requires transparency. Further, when a carrier having a color or pattern is used, it is preferable to use such a transparent photocatalyst layer because the color and pattern of the base are not impaired. When a photocatalyst having a particle size of 50 nm or more is used, the parallel light transmittance is reduced and the haze rate is increased as compared with the case where a photocatalyst having a particle size of 50 nm or less is used.

In the present invention, when an oxide of zirconium or aluminum, an oxide hydroxide, or a hydroxide is used, the specific surface area after drying at 150 ° C for 60 minutes is 100 m.²It is preferable to use a porous gel of / g or more. The porous gel has adsorptive properties and has the effect of increasing photocatalytic activity.

When a sol-like photocatalyst, a zirconium compound and / or an aluminum compound is used, an acid or alkaline sizing agent can be added to the coating liquid for forming a photocatalyst for stabilization. Further, in order to improve the adhesiveness and operability, a surfactant of 5% by weight or less can be added to the photocatalyst in the sol suspension.

The silicon compound in the present invention is not particularly limited, and examples thereof include a silicon resin and polysiloxane. More specifically, for example, the formula (I)

<chemistry num="1"><img file="JP2007055207A_D0001.tif" /></chemistry>

(In the formula, R₁Indicates an alkyl group which may have a substituent having 1 to 20 carbon atoms, and X₁, X₂And X₃Independently indicate a chlorine atom, a hydrogen atom, a hydroxyl group, or an alkoxy group having 1 to 8 carbon atoms. ), Silicon compound, formula (II)

<chemistry num="2"><img file="JP2007055207A_D0002.tif" /></chemistry>

(In the formula, R₁And R₂Indicates an alkyl group that may independently have a substituent having 1 to 20 carbon atoms.₁And X₂Independently indicate a chlorine atom, a hydrogen atom, a hydroxyl group, or an alkoxy group having 1 to 8 carbon atoms. ), And formula (III)

<chemistry num="3"><img file="JP2007055207A_D0003.tif" /></chemistry>

(In the formula, R₁, R₂And R₃Indicates an alkyl group that may independently have a substituent having 1 to 20 carbon atoms.₁Indicates a chlorine atom, a hydrogen atom, a hydroxyl group, or an alkoxy group having 1 to 8 carbon atoms. ), And one or more silicon compounds selected from the group consisting of their hydrolysis products.

Here, as the alkyl group having 1 to 20 carbon atoms, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. , Hexyl group, heptyl group, octyl group, decyl group, dodecyl group, octadecyl group and the like. Also, X₁, X₂And X₃Indicates a chlorine atom, a hydrogen atom, a hydroxyl group, or an alkoxy group having 1 to 8 carbon atoms. At this time, X₁, X₂And X₃May be the same or different. Here, as the alkoxy group having 1 to 8 carbon atoms, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group and a hexyloxy group. , 2-Ethylhexyloxy group, octyloxy group and the like.

More specifically, among the above silicon compounds, as the monosubstituted alkyl silicon compound represented by the formula (I), n-butyltrichlorosilane, n-butyltrimethoxysilane, n-decyltrichlorosilane, n-decyl Triethoxysilane, dimethoxymethylchlorosilane, n-dodecyltrichlorosilane, n-dodecyltriethoxysilane, ethyltrichlorosilane, ethyltriethoxysilane, ethyltrimethoxysilane, n-heptiltrichlorosilane, n-hexadecyltrichlorosilane, n- Hexadecyltrimethoxysilane, n-hexyltrichlorosilane, n-hexyltriethoxysilane, n-hexyltrimethoxysilane, methyltrichlorosilane, methyltriethoxysilane, n-octadecyltrichlorosilane, n-octadecyltriethoxysilane, n- Examples thereof include octadecyltrimethoxysilane, n-propyltrichlorosilane, n-propyltriethoxysilane, and n-propyltrimethoxysilane.

Examples of the disubstituted alkyl silicon compound represented by the formula (II) include n-butylmethyldichlorosilane, n-decylmethyldichlorosilane, di-n-butyldichlorosilane, diethyldichlorosilane, and diethyldiethoxysilane. Di-n-hexyldichlorosilane, dimethyldichlorosilane, dimethyldiethoxysilane, dimethyldimethoxysilane, dimethyldipropoxysilane, dimethylmethoxychlorosilane, di-n-octyldichlorosilane, docosylmethyldichlorosilane, dodecylmethyldichlorosilane, dodecyl Methyldiethoxysilane, ethylmethyldichlorosilane, n-heptylmethyldichlorosilane, n-hexylmethyldichlorosilane, methylpentyldichlorosilane, n-octadecylmethoxydichlorosilane, n-octadecylmethyldichlorosilane, propylmethyldichlorosilane, etc. Be done.

Examples of the trisubstituted alkyl silicon compound represented by the formula (III) include n-decyldimethylchlorosilane, ethyldimethylchlorosilane, n-octadecyldimethylchlorosilane, n-octadecyldimethylmethoxysilane, n-octyldimethylchlorosilane, and n-. Examples thereof include propyldimethylchlorosilane, trimethylchlorosilane, trimethylethoxysilane, trimethylmethoxysilane, trimethyl-n-propoxysilane, and tri-n-propylchlorosilane.

In addition, in the silicon compound represented by the formula (I), the silicon compound represented by the formula (II), and the silicon compound represented by the formula (III), R₁, R₂, And R₃May have a substituent and may have a branch. Examples of the substituent include an amino group, a carboxyl group, a chlorine atom and the like. Also, R₁, R₂And R₃May be an alkyl group which may independently have a substituent having 1 to 8 carbon atoms.

Further, among the above-mentioned silicon compounds in the present invention, the formula (IV): SiCln₁(OH) n₂R₄n₃(OR₅) n₄It is preferably a silicon alkoxide represented by or a hydrolysis product thereof. Where R₄Is methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, hexyl, octyl, aminomethyl, aminoethyl, carboxymethyl, carboxyethyl, chloromethyl, chloroethyl, chloropropyl group, etc. (amino group, carboxyl) Represents an alkyl group having 1 to 8 carbon atoms (which may be substituted with a group or a chlorine atom). R₅Is an alkyl group having 1 to 8 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, hexyl group, or methoxymethyl, ethoxymethyl, propoxymethyl, isopropoxymethyl, butoxymethyl, Represents an alkyl group having 1 to 8 carbon atoms substituted with an alkoxy group such as methoxyethyl, ethoxymethyl, propoxyethyl, methoxypropyl, or methoxybutyl group. Also n₁, N₂And n₃Represents 0, 1 or 2 and n₄Represents an integer from 2 to 4, and n₁+ n₂+ n₃+ n₄= 4.

Preferred specific examples of the silicon alkoxide represented by the formula (IV) include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, and methyltriethoxysilane.

The silicon compound in the present invention does not have to be a mixture of spherical colloidal silica particles or rod-shaped colloidal silica, but since the transparency of the photocatalyst layer can be maintained for a longer period of time, a mixture of spherical colloidal silica particles or rod-shaped colloidal silica can be maintained. Alternatively, it is preferable to include a mixture thereof in the photocatalyst layer. The conjugate or rod-shaped colloidal silica of the spherical colloidal silica particles and their preferred embodiments are the same as the conjugate or rod-shaped colloidal silica of the spherical colloidal silica particles in the above-mentioned adhesive layer.

The method for forming the photocatalyst layer on the surface of the adhesive layer is not particularly limited, and for example, a coating liquid for forming a photocatalyst layer described later can be applied by a method such as a printing method, a sheet forming method, a spray spraying method, a dip coating method, or a spin coating method. A method of coating the surface of the adhesive layer and drying / curing it can be exemplified. The temperature at the time of drying and curing varies depending on the carrier material and the resin material in the adhesive layer, but is usually preferably about 50 ° C to 300 ° C.

The thickness of the photocatalyst layer in the present invention is not particularly limited, but is preferably in the range of 0.1 to 20 μm. When the photocatalyst layer is formed by using a specific coating liquid for forming a photocatalyst layer, the thicker the photocatalyst layer, the higher the obtained photocatalyst activity tends to be. However, when the thickness of the photocatalyst layer exceeds 20 μm. While the photocatalytic activity is almost saturated, the actual coating process is often difficult, and the light transmittance of the photocatalyst layer is lowered. On the other hand, when the thickness of the photocatalyst is less than 0.1 μm, although the translucency is good, most of the ultraviolet rays used when the photocatalyst exerts the photocatalytic action also pass through the photocatalyst layer, so that the photocatalyst activity is excellent. May not be obtained.

In the photocatalyst-supporting structure of the present invention, the total light transmittance at a wavelength of 550 nm in the coating film obtained by combining the photocatalyst layer and the adhesive layer may be less than 80%, or the haze rate may be higher than 2%, but the photocatalyst layer It is preferable that the total light transmittance at a wavelength of 550 nm is 80% or more and the haze rate is 2% or less in the coating film in which the adhesive layer is combined. For such a photocatalyst-supporting structure, for example, the thickness of the photocatalyst layer is in the range of 0.1 to 20 μm, and photocatalyst particles having an average particle of 50 nm or less, and a gel of an aluminum oxide or hydroxide are used. As long as the total light transmittance at a wavelength of 550 nm is 80% or more and the haze rate is 2% or less in the coating film obtained by combining the photocatalyst layer and the adhesive layer, such a photocatalyst-supporting structure can be used. It is not limited. When the photocatalyst layer and the adhesive layer are used for a transparent carrier, visible light transmitted through the photocatalyst-supported structure composed of the photocatalyst layer, the adhesive layer and the carrier can be used as illumination, and when the photocatalyst layer and the adhesive layer are used for an opaque carrier. However, since the pattern or pattern on the carrier is not impaired, a photocatalyst-supporting structure having excellent decorativeness can be obtained.

Further, in the photocatalyst-supported structure of the present invention, the haze rate of the coating film including the adhesive layer and the photocatalyst layer after boiling in boiling ion-exchanged water for 1 hour may be higher than 3%, but is 3% or less. It is preferable to have. For such a photocatalyst-supporting structure, for example, the thickness of the photocatalyst layer is in the range of 0.1 to 20 μm, and photocatalyst particles having an average particle of 50 nm or less, and a gel of an aluminum oxide or hydroxide are used. However, as long as the haze rate of the coating film including the adhesive layer and the photocatalyst layer after boiling in boiling ion-exchanged water for 1 hour is 3% or less, the structure is limited to such a photocatalyst-supporting structure. is not it.

Further, the photocatalyst-supported structure of the present invention has an ultraviolet intensity of 3 mW / cm.²The haze rate of the coating film including the adhesive layer and the photocatalyst layer after irradiation with the black light of 40 ° C. and 90% relative humidity for 500 hours may be higher than 3%, but 3 It is preferably less than or equal to%. For such a photocatalyst-supporting structure, for example, a photocatalyst layer having a thickness in the range of 0.1 to 20 μm and a photocatalyst particle having an average particle of 50 nm or less, and an aluminum oxide or hydroxide gel may be used. Obtained by UV intensity 3mW / cm²As long as the haze rate of the coating film including the adhesive layer and the photocatalytic layer after irradiation with black light of 40 ° C. and 90% relative humidity for 500 hours is 3% or less, such The structure is not limited to the photocatalyst-supported structure.

The photocatalyst-supporting structure of the present invention includes architectural paints, wallpaper, windowpanes, blinds, curtains, carpets, lighting fixtures, lighting, road lights, tunnel lighting, highway and Shinkansen sound insulation walls, black lights, ship bottoms and fishing nets. It can be used for antifouling paints, fillers for water treatment, agricultural bifilm, weed control sheets, packaging materials, etc. Especially when it is used in a hot and humid environment or in an outdoor environment, it exhibits characteristics such as excellent durability and excellent transparency and retention.

The material, shape, thickness, etc. of the carrier in the present invention are not particularly limited. The material of the carrier may be, for example, ceramics; inorganic material; organic material; or the like, and further, the carrier material is an organic polymer that cannot be heated; a metal that is easily oxidatively corroded by heat, water, or the like; It may be. Further, as the shape of the carrier, for example, any complicated shape such as a film shape, a sheet shape, a plate shape, a tubular shape, a fibrous shape, and a net shape can be used. The thickness of the carrier is preferably 10 μm or more because it can firmly support the photocatalyst layer and the adhesive layer. Further, in order to improve the adhesion between the carrier and the adhesive layer, it is also possible to use a carrier whose surface has been subjected to an easy adhesion treatment such as a discharge treatment or a primer treatment. Further, the carrier in the present invention is preferably for an outer wall.

The method for preparing the coating liquid for forming an adhesive layer of the present invention is not particularly limited, and for example, a method of mixing a mixture of spherical colloidal silica particles, rod-shaped colloidal silica, or a mixture thereof in a solvent and the like are used. Illustrated.

The content of silica bonded to an elongated shape contained in the coating liquid for forming an adhesive layer of the present invention is not particularly limited as long as the effect of the present invention that the transparency of the photocatalyst layer and the adhesive layer is maintained for a long period of time can be obtained. , It is preferable that the amount is 0.01 to 12.0% by weight in terms of oxide with respect to the coating liquid for forming the adhesive layer.

Examples of the solvent used include alcohols such as water, methanol, ethanol, propyl alcohol, isopropyl alcohol, butanol and t-butanol, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, acetyl acetone and cyclohexanone, diethyl ether and methyl. Ethers such as cellsolve and tetrahydrofuran, aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as dichloromethane and chloroform, esters such as succinethyl, propyl acetate and butyl acetate, pentane, hexane, cyclohexane and the like. Saturated hydrocarbons and the like can be mentioned.

The method for preparing the coating liquid for forming the photocatalyst layer is not particularly limited, and examples thereof include a method of mixing the photocatalyst with a zirconium compound, an aluminum compound, and a silicon compound in a solvent. As the solvent, the same solvent as that in the coating liquid for forming the adhesive layer can be mentioned.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the technical scope of the present invention is not limited to these examples.

1) Production of Photocatalyst-Supported Structure The photocatalyst-supported structures of Examples 1 to 6 and Comparative Examples 1 to 3 having the configurations shown in Table 1 below were produced as follows.

(1) Adhesive layer Silicon-modified resin, etc. (PS-1), resin solution (J-1), colloidal silica (KS-1, KS-2) were mixed to obtain a solution for forming an adhesive layer whose concentration was adjusted. .. This solution was coated and formed on a soda lime glass carrier (TA) by a dipping method. It was dried at room temperature for 60 minutes to form an adhesive layer with a thickness of 1 μm. (PS-1): Polyethoxysiloxane (manufactured by Corcote, trade name ethyl silicate 40) (J-1): Acrylic silicone resin xylene solution (silicon content 3% by weight) The silicon content is SiO in the resin solid content.₂It was converted to and displayed. (KS-1): Colloidal silica (manufactured by Nissan Chemical Industries, Ltd., trade name Snowtex PS-S, necklace-shaped) (KS-2): Colloidal silica (manufactured by JGC Catalysts and Chemicals, trade name Cataloid SI-350, granular)

(2) Photocatalyst layer The photocatalyst, silica sol, aluminum compound and zirconium compound shown below are mixed and prepared in an appropriate range of pH 1.5 to 9, and then a predetermined amount of surfactant is added to the photocatalyst complex solution (photocatalyst layer). Composition for formation) was obtained. The obtained photocatalytic complex solution was coated and formed on the adhesive layer by a dipping method. The photocatalyst layer was dried at the same temperature as the adhesive layer was dried to form a thickness of 1 μm. The following photocatalysts, silica sol, aluminum compounds, and zirconium compounds were used. (T-1): Nitrate acid titanium oxide sol (crystal particle size 8 nm) (KS-1): Colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name Snowtex PS-S, necklace) (A-1): Aluminum compound (Nissan) Chemical product, trade name Aluminasol-520) (Z-1): After dissolving a zirconium compound (zirconium oxynitrate hexahydrate zirconium compound (Wako Pure Chemicals, special grade reagent) in water to make a 10% aqueous solution, 12 The solution obtained by heating for hours to remove half of the water was used as a zirconium oxynitrate solution).

<tables num="1"><img file="JP2007055207A_D0004.tif" /></tables>

2) Performance test of photocatalyst-supported structure The following performance evaluation test was performed using the photocatalyst-supported structure obtained in 1) above. (1) Evaluation test of photocatalyst activity Using the photocatalyst-supported structure obtained in 1) above, a test piece having a size of 70 mm × 70 mm was cut out and placed in a glass container made of Pyrex (registered trademark) having a capacity of 4 L. In this container, a mixed gas of air and aldehyde was adjusted to an aldehyde concentration of 2000 ppm, and then the sample was subjected to an ultraviolet intensity of 2 mW / cm.²After irradiating with black light (FL15BLB, manufactured by Toshiba Litec) for 3 hours, the concentration of aldehyde gas inside the container was measured by gas chromatography, and the photocatalytic activity was evaluated by the amount of decrease. As a result, the photocatalyst-supported structures of Examples 1 to 6 and Comparative Examples 1 to 3 showed a reduction of aldehyde gas of 100 ppm or more, respectively, and thus all the photocatalyst-supported structures showed excellent photocatalytic activity. Do you get it.

(2) Measurement of haze rate The haze rate was measured with a turbidity meter (NDH 300A manufactured by Nippon Denshoku Kogyo Co., Ltd.). Air was measured as a reference. The haze rate (%) was calculated from the formula "(total light transmittance-parallel light transmittance) x 100 / total light transmittance". The measurement results are shown in Table 2 below.

(3) Tape peeling test Twenty-five squares were formed on the surface of each sample at intervals of 2 mm, and the adhesiveness was evaluated by the grid tape method test specified in JIS K5400. Those that did not peel off were evaluated as , and those that peeled off even a little were evaluated as x. The evaluation results are shown in Table 2 below.

(4) Finger friction test The surface of the sample was rubbed with a finger, and those that did not peel off were evaluated as , and those that peeled off even a little were evaluated as x. The evaluation results are shown in Table 2 below.

(5) Durability test UV intensity 3mW / cm with black light on the sample surface²After irradiating the light in a constant temperature and humidity chamber with a temperature of 40 ° C. and a relative humidity of 90% for 2000 hours, a tape peeling test and a finger friction test were performed to evaluate the durability. The results are shown in Table 2 below.

<tables num="2"><img file="JP2007055207A_D0005.tif" /></tables>

From Table 2, the photocatalyst-supported structures of Examples 1 to 6 maintained a low haze rate and had excellent weather resistance even in the accelerated weather resistance test. In comparison, Comparative Example 1 having an adhesive layer formed from an adhesive layer forming solution to which colloidal silica was not added was excellent in adhesion but inferior in weather resistance in haze rate. Comparative Example 2 having a photocatalyst layer using a photocatalyst complex solution formed only of a photocatalyst and a silica sol was inferior in weather resistance in terms of haze rate and adhesion. Comparative Example 3 having an adhesive layer formed from a solution for forming an adhesive layer to which spherical colloidal silica was added showed inferior weather resistance in terms of haze rate and adhesion.

The photocatalyst-supported structure of the present invention has high photocatalytic activity and excellent transparency, the photocatalyst is firmly adhered to the carrier, and the carrier does not deteriorate or the photocatalyst does not come off due to the photocatalytic action. .. In addition, it can be used for a long time even under light irradiation, and can be used in a hot and humid environment or an outdoor environment.