JP2009119462A - Photocatalytic coated body and photocatalytic coating liquid for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocatalytic coated body which exhibits excellent weather resistance, harmful gas decomposing property, suppression of the propagation of fungi or algae and other desired characteristics (ultraviolet absorption, transparency, film strength and the like) while preventing erosion to a base material, and to provide a photocatalytic coating liquid for manufacturing the photocatalytic coated body. <P>SOLUTION: The photocatalytic coated body comprises the base material; and a photocatalytic layer disposed on the base material. The photocatalytic layer contains: photocatalytic particles of 1 pts.wt. or more and less than 20 pts.wt.; inorganic oxide particles of more than 70 pts.wt. and of 99 pts.wt. or less; copper element; silver element; and a dried hydrolytic silicone of 0 pts.wt. or more and less than 10 pts.wt. in terms of silica as an arbitrary component such that the total amount of the photocatalytic particles, inorganic oxide particles and the hydrolytic silicone in terms of silica amounts to 100 pts.wt. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photocatalyst-coated body excellent in weather resistance, harmful gas decomposability, mold and algae growth suppression, and various coating properties, and a photocatalyst coating liquid therefor, which are particularly suitable for the use of exterior materials such as buildings.

  In recent years, photocatalysts such as titanium oxide have been used in many applications such as exterior materials for buildings. By using photocatalyst, it is possible to decompose various harmful substances using light energy, or to make the surface of the substrate coated with photocatalyst hydrophilic and easily wash away dirt adhering to the surface with water. . The following are known as techniques for obtaining a photocatalyst-coated body coated with such a photocatalyst.

  A technique for imparting hydrophilicity to the surface of a synthetic resin or the like using an aqueous dispersion containing photocatalytic metal oxide particles, colloidal silica, and a surfactant is known (Patent Document 1 (Japanese Patent Application Laid-Open No. Hei 5 (1994)). 11-14432 publication). In this technique, hydrophilicity is enhanced by containing a surfactant in a large amount of 10 to 25% by weight. Moreover, the cloudiness by the irregular reflection of light is prevented by making a film thickness into 0.4 micrometer or less.

A technique for obtaining a photocatalyst by forming a coating film containing silica sol as a binder component and photocatalytic titanium dioxide on a substrate is also known (see Japanese Patent Application Laid-Open No. 11-169727). In this technique, the amount of silica sol added is ₂₀ to 200 parts by weight with respect to titanium dioxide on the basis of SiO ₂ , and the content ratio of titanium dioxide is high. In addition, the particle size of silica sol is as small as 0.1 to 10 nm.

  There is also known a technique for forming a photocatalyst coating film by transmitting 50% or more of light having a wavelength of 500 nm and blocking 80% or more of light having a wavelength of 320 nm by using a photocatalyst paint (Japanese Patent Application Laid-Open No. 2004-359902). No.)). In this technique, an organosiloxane partial hydrolyzate is used as a binder of a photocatalyst coating, and the blending amount is preferably 5 to 40% by weight of the entire coating composition.

  A technique is known in which metallic silver and metallic copper or ions thereof are added to a photocatalyst layer to impart a deodorizing, antibacterial, and antifungal function (see Patent Document 4 (Patent No. 3555992)).

  A technique for increasing the photocatalytic activity by adding silver, copper, zinc, platinum or the like to the photocatalyst layer is known (see Patent Document 5 (Japanese Patent Laid-Open No. 11-169726)), (Patent Document 6 (International Publication No. 00 / No. 06300 pamphlet)).

  By the way, when the base material of a photocatalyst layer is comprised with an organic material, the problem that an organic material is decomposed | disassembled or deteriorated by the photocatalytic activity of a photocatalyst is known conventionally. In order to cope with this problem, a technique for protecting an underlying carrier from degradation due to photocatalysis by providing an adhesive layer such as a silicon-modified resin between the photocatalyst layer and the carrier is known (Patent Document 7 (International Publication 97/00134 pamphlet)).

Japanese Patent Application Laid-Open No. 11-14432 JP 11-169727 A JP 2004-359902 A Japanese Patent No. 355992 JP-A-11-169726 International Publication No. 00/06300 Pamphlet WO97 / 00134 pamphlet

  The present inventors now include photocatalyst particles and inorganic oxide particles in a specific mass ratio, and further contain copper element and silver element, and do not contain hydrolyzable silicone and surfactant, or as little as possible. By configuring the photocatalyst layer with a suppressed specific composition, while suppressing erosion to the substrate (especially organic substrate), weather resistance, harmful gas decomposability, mold and algae growth suppression, and various desired film properties The knowledge that a photocatalyst-coated body excellent in (ultraviolet absorption, transparency, film strength, etc.) was obtained was obtained.

  Therefore, the object of the present invention is to prevent erosion of the base material (especially organic base material), weather resistance, harmful gas decomposability, mold and algae growth inhibition, and various desired film properties (ultraviolet absorption, transparency). Another object is to provide a photocatalyst-coated body excellent in film strength and the like, and a photocatalyst coating liquid therefor.

That is, the photocatalyst-coated body according to the present invention is
A photocatalyst-coated body comprising a substrate and a photocatalyst layer provided on the substrate,
The photocatalytic layer is
1 to 20 parts by mass of photocatalyst particles,
Inorganic oxide particles exceeding 70 parts by mass and 99 parts by mass or less;
0 to 10 parts by weight of hydrolyzable silicone dry matter in terms of silica;
Including the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone in a total amount of silica equivalent of 100 parts by mass,
In addition, containing copper element and silver element,
The photocatalyst layer has gaps between particles.

Moreover, the photocatalyst coating liquid according to the present invention is a photocatalyst coating liquid used for producing the photocatalyst-coated body,
A solvent,
1 to 20 parts by mass of photocatalyst particles,
Inorganic oxide particles exceeding 70 parts by mass and 99 parts by mass or less;
Hydrolyzable silicone of 0 parts by weight or more and less than 10 parts by weight in terms of silica;
In such a manner that the total amount of silica equivalents of the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone is 100 parts by mass, and further contains a copper element and a silver element.

Photocatalyst-coated body The photocatalyst-coated body according to the present invention comprises a base material and a photocatalyst layer provided on the base material. The photocatalyst layer is 1 part by mass or more and less than 20 parts by mass of photocatalyst particles, more than 70 parts by mass of inorganic oxide particles of 99 parts by mass or less, copper element, silver element, and optional components, 0 mass in terms of silica. And a dry product of hydrolyzable silicone in an amount of 10 parts by weight or more and less than 10 parts by weight, and the photocatalyst layer is characterized in that there are gaps between particles.

  That is, the photocatalyst layer according to the present invention is basically composed of 1 part by mass or more and less than 20 parts by mass of photocatalyst particles and more than 70 parts by mass and 99 parts by mass or less of inorganic oxide particles, and further includes copper element and silver element Comprising. With this configuration, while preventing erosion to the substrate (especially organic substrate), weather resistance, harmful gas decomposability, mold and algae growth suppression, and various desired film properties (ultraviolet absorption, transparency, film strength, etc.) Can be obtained. The reason why these excellent effects are realized at the same time is not clear, but is thought to be as follows. However, the following description is merely a hypothesis, and the present invention is not limited by the following hypothesis. First, since the photocatalyst layer is basically composed of two types of particles, photocatalyst particles and inorganic oxide particles, there are abundant gaps between the particles. When a large amount of hydrolyzable silicone widely used as a binder for the photocatalyst layer is used, it is considered that the gap between the particles is densely filled, and thus gas diffusion is hindered. However, the photocatalyst layer of the present invention does not contain hydrolyzable silicone or even if it contains less than 10 parts by mass with respect to 100 parts by mass of the total amount of photocatalyst particles, inorganic oxide particles, and hydrolyzable silicone, It is considered that a sufficient gap between particles can be secured. Such a gap realizes a structure in which harmful gases such as NOx and SOx are likely to diffuse into the photocatalyst layer, and as a result, the harmful gas may be efficiently contacted with the photocatalyst particles and decomposed by the photocatalytic activity. Conceivable.

Copper element and silver element exist as metals and / or metal compounds. The ratio of silver element to copper element is preferably 0/100 <[Ag ₂ O / CuO] ≦ 60/40 in terms of mass ratio as Ag ₂ O / CuO in terms of Ag ₂ O and CuO, respectively. Is from 10/90 to 60/40, more preferably from 10/90 to 55/45. Also, elemental copper and silver elements, which total amount in terms of Ag 2 _O and CuO are added 0.5 to 5 wt% with respect to the photocatalyst particles. When the ratio of the silver element to the copper element is in such a range, compared to the photocatalyst layer to which each of the copper element and the silver element is added alone, it has antifungal properties under irradiation of light capable of exciting the photocatalyst such as ultraviolet rays. And a photocatalyst layer with extremely good alga-proof properties.

When an appropriate amount of ultraviolet rays is irradiated in a situation where a photocatalyst, a copper compound and a silver compound coexist, it is considered that the photocatalyst and the copper compound directly act on antifungal properties. It is considered that the silver compound is reduced by electrons generated by the photocatalyst and contributes to improvement of charge separation efficiency. The optimum value for the Ag ₂ O / CuO ratio in the photocatalyst layer is that if the ratio is too small, the specific effect due to the coexistence of the silver compound is also small. This is presumably because the relative concentration of the compound is reduced, the antifungal property is reduced, and further, the influence of coloring by silver cannot be ignored.

  At the same time, the proportion of photocatalyst particles is considerably less than that of inorganic oxide particles, so that direct contact of the photocatalyst particles with the substrate can be minimized, thereby reducing the substrate (especially organic substrate). It is thought that it becomes difficult to erode. Further, it is considered that the amount of ultraviolet rays reaching the substrate can be reduced by the ultraviolet absorption by the photocatalyst itself, and damage to the substrate due to ultraviolet rays can be reduced. As a result, the photocatalyst layer of the present invention can be directly applied to a substrate having at least a surface formed of an organic material without interposing an intermediate layer for protecting the substrate. Therefore, the time and cost required for manufacturing the photocatalyst-coated body can be reduced by the amount that the intermediate layer is not required. Further, the photocatalyst layer of the present invention may be constituted without containing a surfactant, but even if it is contained, the photocatalyst layer, inorganic oxide particles, and hydrolyzable silicone are added in an amount of 100 parts by mass. When the amount is less than 10 parts by mass, it is considered that deterioration of the function of film strength and harmful gas decomposability due to containing a large amount of surfactant is prevented. The various phenomena described above occur simultaneously, preventing erosion of the base material (especially organic base material), weather resistance, harmful gas decomposability, and various desired film properties (ultraviolet absorption, transparent It is considered that a photocatalyst-coated body excellent in properties, film strength, etc. is realized.

Base Material The base material used in the present invention may be various materials regardless of inorganic materials or organic materials as long as it can form a photocatalyst layer thereon, and the shape is not limited. Preferred examples of the substrate from the viewpoint of materials include metals, ceramics, glass, plastics, rubber, stones, cement, concrete, fibers, fabrics, wood, paper, combinations thereof, laminates thereof, Examples thereof include those having at least one layer of coating on the surface. Preferred examples of base materials from the viewpoint of applications include building materials, building exteriors, window frames, window glass, structural members, exteriors and coatings of vehicles, exteriors of machinery and articles, dust covers and coatings, traffic signs, and various displays Equipment, advertising towers, sound insulation walls for roads, sound insulation walls for railways, bridges, guard rail exteriors and paintings, tunnel interiors and paintings, insulators, solar cell covers, solar water heater heat collection covers, plastic houses, vehicle lighting covers General exterior materials such as outdoor lighting fixtures, stands, and films, sheets, seals and the like for attaching to the article surface.

  According to a preferred embodiment of the present invention, a substrate having at least a surface formed of an organic material can be used as the substrate, and the entire substrate is formed of an organic material or an inorganic material. Any of those in which the surface of the substrate is coated with an organic material (for example, a decorative board) is included. According to the photocatalyst layer of the present invention, it is difficult to erode even to an organic material that is easily damaged by the photocatalytic activity, and therefore, a photocatalyst coating having an excellent function in one layer called a photocatalyst layer without interposing an intermediate layer The body can be manufactured. As a result, the time and cost required for manufacturing the photocatalyst-coated body can be reduced by the amount that the intermediate layer is not required.

Photocatalyst layer and photocatalyst coating liquid therefor The photocatalyst layer of the present invention comprises 1 to 20 parts by mass of photocatalyst particles, 70 to 99 parts by mass of inorganic oxide particles, copper element, and silver element And 0 to 10 parts by mass of hydrolyzable silicone dry matter in terms of silica, the total amount of photocatalyst particles, inorganic oxide particles, and hydrolyzable silicone in terms of silica is 100 parts by mass. As including. And this photocatalyst layer can be formed by apply | coating a photocatalyst coating liquid formed by disperse | distributing a photocatalyst particle, an inorganic oxide particle, and a hydrolysable silicone in the said mass ratio in a solvent on a base material.

  According to a preferred embodiment of the present invention, the photocatalyst layer preferably has a film thickness of 0.5 μm or more and 3 μm or less, more preferably 1.0 μm or more and 2.0 μm or less. Within such a range, the ultraviolet rays that reach the interface between the photocatalyst layer and the substrate are sufficiently attenuated, thereby improving the weather resistance. Moreover, since the photocatalyst particles having a lower content ratio than the inorganic oxide particles can be increased in the film thickness direction, harmful gas decomposability is also improved. Furthermore, excellent characteristics can be obtained in terms of ultraviolet absorption, transparency, and film strength.

The photocatalyst particles used in the present invention are not particularly limited as long as they have photocatalytic activity, and all kinds of photocatalyst particles can be used. Examples of the photocatalyst particles include metal oxide particles such as titanium oxide (TiO ₂ ), ZnO, SnO ₂ , SrTiO ₃ , WO ₃ , Bi ₂ O ₃ , Fe ₂ O ₃ , and preferably titanium oxide. Particles, more preferably anatase type titanium oxide particles. Titanium oxide is harmless, chemically stable, and available at low cost. Titanium oxide has a high band gap energy, and therefore requires ultraviolet light for photoexcitation and does not absorb visible light in the process of photoexcitation, so that no color formation due to a complementary color component occurs. Titanium oxide is available in various forms such as powder, sol, and solution, but any form can be used as long as it exhibits photocatalytic activity.

  According to a preferred embodiment of the present invention, the photocatalyst particles preferably have an average particle size of 10 nm to 100 nm, more preferably 10 nm to 60 nm. The average particle diameter is calculated as a number average value obtained by measuring the length of any 100 particles that enter a 200,000-fold field of view with a scanning electron microscope. As the particle shape, a true sphere is most preferable, but a substantially circular or elliptical shape is also preferable. In this case, the particle length is approximately calculated as ((major axis + minor axis) / 2). Within this range, weather resistance, harmful gas decomposability, and various desired film properties (such as ultraviolet absorption, transparency, and film strength) are efficiently exhibited.

  The content of the photocatalyst particles in the photocatalyst layer and the coating liquid of the present invention is 1 part by mass or more and 20 parts by mass with respect to 100 parts by mass of the total amount of photocatalyst particles, inorganic oxide particles, and hydrolyzable silicone in terms of silica. Less than, preferably 5 parts by mass or more and 15 parts by mass or less, more preferably 5 parts by mass or more and 10 parts by mass or less. By reducing the blending ratio of the photocatalyst particles in this way, the direct contact of the photocatalyst particles with the base material can be reduced as much as possible to prevent erosion of the base material (especially organic material) and the weather resistance is also improved. It is thought to improve. Nevertheless, functions due to photocatalytic activity such as decomposability of harmful gas and ultraviolet absorption can be sufficiently exhibited.

  The photocatalyst layer and the coating liquid of the present invention contain copper element and silver element in order to exhibit high photocatalytic ability. In these, a metal and / or a metal compound composed of the metal can be added to the photocatalyst layer and the photocatalyst coating liquid. This addition can be carried out by any of a method of mixing the metal or metal compound into the photocatalyst coating liquid and a method of supporting the metal compound on the photocatalyst particles or the photocatalyst layer.

  The inorganic oxide particles used in the present invention are not particularly limited as long as they are inorganic oxide particles capable of forming a layer together with photocatalyst particles, and any kind of inorganic oxide particles can be used. Examples of such inorganic oxide particles include single oxide particles such as silica, alumina, zirconia, ceria, yttria, boronia, magnesia, calcia, ferrite, amorphous titania, hafnia; and barium titanate, silica The particle | grains of complex oxides, such as calcium acid, are mentioned, More preferably, it is a silica particle. These inorganic oxide particles are preferably in the form of an aqueous colloid using water as a dispersion medium; or an organosol dispersed in a hydrophilic solvent such as ethyl alcohol, isopropyl alcohol, or ethylene glycol, and particularly preferably. Colloidal silica.

  According to a preferred embodiment of the present invention, the inorganic oxide particles have an average particle size of more than 5 nm and less than 40 nm, more preferably more than 5 nm and 30 nm or less, and further preferably 10 nm or more and 30 nm or less. The average particle diameter is calculated as a number average value obtained by measuring the length of any 100 particles that enter a 200,000-fold field of view with a scanning electron microscope. As the particle shape, a true sphere is most preferable, but a substantially circular or elliptical shape is also preferable. In this case, the particle length is approximately calculated as ((major axis + minor axis) / 2). Within this range, weather resistance, harmful gas decomposability, and various desired film properties (such as ultraviolet absorption, transparency, and film strength) are efficiently exhibited. In addition, a photocatalyst layer that is transparent and has good adhesion can be obtained.

  The content of the inorganic oxide particles in the photocatalyst layer and the coating liquid of the present invention exceeds 70 parts by mass with respect to 100 parts by mass as the total amount of silica of the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone. 99 parts by mass or less, preferably 80 parts by mass or more and 95 parts by mass or less, more preferably 85 parts by mass or more and 95 parts by mass or less, and still more preferably 90 parts by mass or more and 95 parts by mass or less.

The photocatalyst layer of the present invention preferably contains substantially no dried hydrolyzable silicone, and more preferably does not contain at all. The hydrolyzable silicone is a general term for an organosiloxane having an alkoxy group and / or a partially hydrolyzed condensate thereof. However, it is allowed to contain hydrolyzable silicone as an optional component as long as the harmful gas decomposability of the present invention can be ensured. Therefore, the content of hydrolyzable silicone is 0 part by mass or more with respect to 100 parts by mass of the total amount of photocatalyst particles, inorganic oxide particles, and hydrolyzable silicone in terms of silica in terms of silica (SiO ₂ ). The amount is less than 10 parts by mass, preferably 5 parts by mass or less, and most preferably 0 part by mass. As the hydrolyzable silicone, a tetrafunctional silicone compound is often used. For example, ethyl silicate 40 (oligomer, R is an ethyl group), ethyl silicate 48 (oligomer, R is an ethyl group), methyl silicate 51 (oligomer, R is a methyl group) Group) (both manufactured by Colcoat Co.).

  The photocatalyst coating liquid may contain a surfactant as an optional component. The surfactant used in the present invention is contained as an optional component in an amount of 0 parts by mass or more and less than 10 parts by mass with respect to 100 parts by mass as a total of 100 parts by mass of photocatalyst particles, inorganic oxide particles, and hydrolyzable silicone. Preferably, they are 0 mass part or more and 8 mass parts or less, More preferably, they are 0 or more and 6 mass parts or less. One of the effects of the surfactant is leveling to the substrate, and the amount of the surfactant may be appropriately determined depending on the combination of the coating liquid and the substrate, and the lower limit in that case is 0.1 part by mass. May be. This surfactant is an effective component for improving the wettability of the photocatalyst coating solution, but in the photocatalyst layer formed after coating, it is an inevitable impurity that no longer contributes to the effect of the photocatalyst-coated body of the present invention. Equivalent to. Therefore, it may be used according to the wettability required for the photocatalyst coating solution, and if the wettability is not a problem, the surfactant may be contained substantially or not at all. The surfactant to be used can be appropriately selected in consideration of the dispersion stability of the photocatalyst and inorganic oxide particles, and wettability when applied on the intermediate layer, but a nonionic surfactant is preferable, More preferably, an ether type nonionic surfactant, an ester type nonionic surfactant, a polyalkylene glycol nonionic surfactant, a fluorine-based nonionic surfactant, or a silicon-based nonionic surfactant is used. Can be mentioned.

  The photocatalyst coating liquid of the present invention can be obtained by dispersing photocatalyst particles, inorganic oxide particles, copper element, silver element, and optionally hydrolyzable silicone and surfactant in the solvent at the above specific mixing ratio. it can. As the solvent, any solvent that can appropriately disperse the above-described constituent components can be used, and water and / or an organic solvent may be used. Moreover, the solid content concentration of the photocatalyst coating liquid of the present invention is not particularly limited, but it is preferably 1 to 10% by mass because it is easy to apply. The components in the photocatalyst coating composition are analyzed by separating the coating solution into particle components and filtrate by ultrafiltration, and analyzing each by infrared spectroscopic analysis, gel permeation chromatography, fluorescent X-ray spectroscopic analysis, etc. It can be evaluated by analyzing the spectrum.

Manufacturing method The photocatalyst coating body of this invention can be easily manufactured by apply | coating the photocatalyst coating liquid of this invention on a base material. As a method for coating the photocatalyst layer, generally used methods such as brush coating, roller, spray, roll coater, flow coater, dip coating, flow coating, screen printing, electrodeposition, vapor deposition and the like can be used. After applying the coating liquid to the substrate, it may be dried at room temperature, or may be heat-dried as necessary, but when heated until sintering proceeds, the voids between the particles are reduced and sufficient photocatalytic activity is obtained. You can't get it. In this invention, drying temperature is 10 degreeC or more and 500 degrees C or less, and an upper limit may be suitably set according to the kind of base material. When the resin is contained in at least a part of the substrate, the preferable drying temperature is 10 ° C. or higher and 200 ° C. or lower in consideration of the heat-resistant temperature of the resin. As described above, according to the photocatalyst layer of the present invention, the photocatalyst-coated body of the present invention is not easily eroded even by an organic material that is easily damaged by photocatalytic activity. A photocatalyst-coated body having an excellent function in one layer can be produced. As a result, the time and cost required for manufacturing the photocatalyst-coated body can be reduced by the amount that the intermediate layer is not required.

The present invention will be specifically described based on the following examples, but the present invention is not limited to these examples.
In the following examples, the raw materials used for preparation of the photocatalyst coating liquid are as follows.
Photocatalyst particles / titania aqueous dispersion (average particle diameter: 42 nm, basic) (used in Examples 1 to 11, Examples 14 to 28, and Example 34)
Ag / Cu-containing titania aqueous dispersion: a photocatalytic titania aqueous dispersion in which the total amount of silver compound and copper compound converted to Ag ₂ O and CuO is added in the following mass% with respect to titania (average particle diameter: 48nm, basic,)
0.5% by mass (used in Examples 29 to 33 and Example 35)
3% by weight (used in Examples 12-13, 36, 38, 39)
・ 5% by mass (used in Example 37)
Inorganic oxide particles / water-dispersed colloidal silica (average particle size: 26 nm, basic) (used in Examples 1-21, 23, and 25-39)
Water-dispersed colloidal silica (average particle size: 14 nm, basic) (used in Example 22)
Water-dispersed colloidal silica (average particle size: 5 nm, basic) (used in Example 24)
Hydrolyzable silicone / tetramethoxysilane polycondensate (manufactured by Tama Chemical Co., Ltd., trade name: M silicate 51) surfactant / polyether-modified silicone surfactant

Examples 1 to 7: Evaluation of weather resistance (reference)
The photocatalyst coating body provided with the photocatalyst layer was manufactured as follows. First, a colored organic coated body was prepared as a base material. This colored organic coated body is obtained by applying general-purpose acrylic silicone to which carbon black powder is added on a float plate glass and sufficiently drying and curing it. On the other hand, a titania aqueous dispersion as a photocatalyst, a water-dispersed colloidal silica as an inorganic oxide, water as a solvent, and a polyether-modified silicone surfactant are mixed at a blending ratio shown in Table 1, A photocatalytic coating solution was obtained. In addition, this photocatalyst coating liquid does not contain hydrolysable silicone. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass.

  The obtained photocatalyst coating liquid was spray-coated on the colored organic coating body previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes. Thus, a photocatalyst layer was formed to obtain a photocatalyst-coated body. When the film thickness of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 0.5 μm in any of Examples 1 to 7.

  About the photocatalyst coating body of a magnitude | size of 50x100 mm obtained in this way, the weather resistance test was done as follows. The photocatalyst-coated body was put into a sunshine weatherometer (S-300C, manufactured by Suga Test Instruments) defined in JIS B7753. After 300 hours, the test piece was taken out, the color difference was measured before and after the acceleration test with a color difference meter ZE2000 manufactured by Nippon Denshoku, and the degree of color change was evaluated by comparing the Δb values.

  The obtained results were as shown in Table 1. Here, G in the table indicates that the color has hardly changed, and NG indicates that the Δb value has shifted to the plus side (yellowing side). As shown in Table 1, it was found that by setting the content of the photocatalyst in the photocatalyst layer to less than 20 parts by mass, the photocatalyst layer has sufficient weather resistance even when the photocatalyst layer is coated on the organic substrate.

Examples 8 to 11: Evaluation of harmful gas decomposability (reference)
The photocatalyst coating body provided with the photocatalyst layer was manufactured as follows. First, a colored organic coated body was prepared as a base material. This colored organic coated body is obtained by applying general-purpose acrylic silicone to which carbon black powder is added on a float plate glass and sufficiently drying and curing it. On the other hand, polycondensation of titania aqueous dispersion as photocatalyst, water-dispersed colloidal silica as inorganic oxide, water as solvent, polyether-modified silicone surfactant, and tetramethoxysilane as hydrolyzable silicone Were mixed at a blending ratio shown in Table 2 to obtain a photocatalyst coating solution. In addition, the photocatalyst coating liquid of Example 8 and Example 10 does not contain hydrolysable silicone. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass.

  The obtained photocatalyst coating liquid was spray-coated on the colored organic coating body previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes. Thus, a photocatalyst layer was formed to obtain a photocatalyst-coated body. When the film thickness (μm) of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 1 μm in any of the examples.

The photocatalyst-coated body having a size of 50 × 100 mm thus obtained was subjected to a gas decomposability test as follows. As a pretreatment, the photocatalyst-coated body was irradiated with BLB light of 1 mW / cm 2 for 12 hours or more. One coated body sample was set in the reaction vessel described in JIS R1701. NO gas was mixed with air adjusted to 25 ° C. and 50% RH so as to be about 1000 ppb, and introduced into a light-shielded reaction vessel for 20 minutes. Thereafter, BLB light adjusted to 3 mW / cm 2 was irradiated for 20 minutes while the gas was introduced. Thereafter, the reaction vessel was shielded from light again with the gas introduced. The NOx removal amount was calculated according to the following formula from the NO and NO2 concentrations before and after the BLB light irradiation.
NOx removal amount = [NO (after irradiation) −NO (at irradiation)] − [NO 2 (at irradiation) −NO 2 (after irradiation)]

  The obtained results were as shown in Table 2. Here, G in the table represents a NOx removal amount of 400 ppb or more, and NG represents a NOx removal amount of 10 ppb or less. As shown in Table 2, when the photocatalyst layer was composed of photocatalyst particles and an inorganic oxide and substantially free of hydrolyzable silicone, good NOx decomposability was exhibited. On the other hand, those containing 10 parts by mass of hydrolyzable silicone were found to lose NOx decomposability.

Examples 12 to 21: Measurement of linear transmittance and ultraviolet shielding rate A photocatalyst-coated body provided with a photocatalyst layer was produced as follows. First, a float plate glass having a transmittance of 94% at a wavelength of 550 nm was prepared as a substrate. On the other hand, a titania aqueous dispersion as a photocatalyst, a water-dispersed colloidal silica as an inorganic oxide, water as a solvent, and 6 parts by mass of polyether with respect to 100 parts by mass of the total amount of photocatalyst particles and inorganic oxide particles. The modified silicone surfactant was mixed at a blending ratio shown in Table 3 to obtain a photocatalyst coating liquid. This photocatalyst coating liquid does not contain hydrolyzable silicone. In Examples 12 and 13, Ag / Cu-containing titania aqueous dispersions were used as photocatalysts. In Examples 14 to 21, titania aqueous dispersions containing no silver compound and copper compound were used. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass.

  The obtained photocatalyst coating liquid was spray-coated on the float plate glass previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes. Thus, a photocatalyst layer was formed to obtain a photocatalyst-coated body. When the film thickness (μm) of the photocatalyst layer was measured by observation with a scanning electron microscope, the values shown in Table 3 were obtained.

  With respect to the photocatalyst-coated body having a size of 50 × 100 mm obtained as described above, the measurement of the linear (550 nm) transmittance and the ultraviolet ray (300 nm) shielding rate was carried out by using an ultraviolet / visible / near infrared spectrophotometer (UV manufactured by Shimadzu Corporation). -3150).

The obtained results were as shown in Table 3. Here, the evaluation criteria of the linear transmittance and the ultraviolet shielding rate were as follows.
<Linear transmittance>
A: Linear (550 nm) transmittance is 97% or more B: Linear (550 nm) transmittance is 95% or more and less than 97% <UV shielding factor>
a: Ultraviolet (300 nm) shielding rate of 80% or more b: Ultraviolet (300 nm) shielding rate of 30% or more and less than 80% c: Ultraviolet (300 nm) shielding rate of less than 30% As shown in Table 3, in the photocatalyst layer When the content of the photocatalyst is 5 to 15 parts by mass, the film thickness is 3 μm or less, so that even if an Ag / Cu-containing titania aqueous dispersion is used for the photocatalyst, ultraviolet rays due to deterioration of organic matter are sufficiently shielded. It was also found that transparency can be secured.

Examples 22 to 24: Measurement of haze (reference)
The photocatalyst coating body provided with the photocatalyst layer was manufactured as follows. First, a float plate glass having a transmittance of 94% at a wavelength of 550 nm was used as a substrate. On the other hand, a titania aqueous dispersion as a photocatalyst, water-dispersed colloidal silica as an inorganic oxide having various average particle diameters shown in Table 4, water as a solvent, and a polyether-modified silicone surfactant are listed in Table 4. To obtain a photocatalyst coating liquid. Therefore, this photocatalyst coating liquid does not contain hydrolyzable silicone. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass.

  The obtained photocatalyst coating liquid was spin-coated on the above-mentioned substrate at 1000 rpm for 10 seconds and dried at 120 ° C. for 5 minutes to obtain a photocatalyst layer. The haze of the photocatalyst-coated body having a size of 50 × 100 mm obtained in this manner was measured using a haze meter (haze-gard plus from Gardner).

  The obtained results were as shown in Table 4. As Table 4 shows, it turned out that the photocatalyst coating body of Examples 22 and 23 can suppress a haze value to less than 1%, and can ensure transparency.

Examples 25 to 28: Evaluation of influence by addition of surfactant (reference)
The photocatalyst coating body provided with the photocatalyst layer was manufactured as follows. First, a colored organic coated body was prepared as a base material. This colored organic coated body is obtained by applying general-purpose acrylic silicone to which carbon black powder is added on a float plate glass and sufficiently drying and curing it. On the other hand, a titania aqueous dispersion as a photocatalyst, a water-dispersed colloidal silica as an inorganic oxide, water as a solvent, and a polyether-modified silicone surfactant are mixed at a blending ratio shown in Table 5, A photocatalytic coating solution was obtained. In addition, this photocatalyst coating liquid does not contain hydrolysable silicone. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass.

  The obtained photocatalyst coating liquid was spray-coated on the colored organic coating body heated to 50 to 60 ° C. in advance, and dried at 120 ° C. for 5 minutes. Thus, a photocatalyst layer was formed to obtain a photocatalyst-coated body. When the film thickness (μm) of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 1 μm in any of Examples 25 to 28.

The photocatalyst-coated body having a size of 50 × 100 mm thus obtained was subjected to a gas decomposability test as follows. As a pretreatment, the photocatalyst was irradiated with BLB light of 1 mW / cm 2 for 12 hours or more. One coated body sample was set in the reaction vessel described in JIS R1701. NO gas was mixed with air adjusted to 25 ° C. and 50% RH so as to be about 1000 ppb, and introduced into a light-shielded reaction vessel for 20 minutes. Thereafter, BLB light adjusted to 3 mW / cm 2 was irradiated for 20 minutes while the gas was introduced. Thereafter, the reaction vessel was shielded from light again with the gas introduced. The NOx removal amount was calculated according to the following formula from the NO and NO2 concentrations before and after the BLB light irradiation.
NOx removal amount = [NO (after irradiation) −NO (at irradiation)] − [NO 2 (at irradiation) −NO 2 (after irradiation)]

  The results obtained were as shown in Table 5. Here, the NOx removal rate in the table is relatively shown with the removal amount of Example 26 as 100. As shown in Table 5, it was found that the removal rate was lowered by increasing the amount of the surfactant added.

Examples 29 to 34: Evaluation of antifungal property by silver compound and copper compound-1
The photocatalyst coating body provided with the photocatalyst layer was manufactured as follows. First, a colored organic coated body was prepared as a base material. This colored organic coated body is obtained by applying general-purpose acrylic silicone to which a white pigment is added on a float plate glass and sufficiently drying and curing it. On the other hand, Ag / Cu-containing titania aqueous dispersion as a photocatalyst, water-dispersed colloidal silica as an inorganic oxide having an average particle size of 26 nm, water as a solvent, and a total amount of photocatalyst particles and inorganic oxide particles of 100 parts by mass 6 parts by mass of a polyether-modified silicone surfactant was mixed at a blending ratio shown in Table 6 to obtain a photocatalyst coating solution. This photocatalyst coating liquid does not contain hydrolyzable silicone. In Examples 29 to 33, an Ag / Cu-containing titania aqueous dispersion in which the compounding ratio of the silver compound and the copper compound was adjusted (all examples are copper compounds and example 33 is all silver compounds) was used. In Example 34, an aqueous titania dispersion containing no silver compound or copper compound was used. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass.

The obtained photocatalyst coating liquid was spray-coated on the colored organic coating body previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes. Thus, a photocatalyst layer was formed to obtain a photocatalyst-coated body. When the film thickness (μm) of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 1 μm in any of Examples 29 to 34. After pre-treatment of these photocatalyst-coated bodies with 1 mW / cm ² of BLB light for 24 hours, the following antifungal test was performed.

The anti-fungal property of the photocatalyst-coated body having a size of 50 × 50 mm thus obtained was evaluated as follows. Aspergillus niger (NBRC6341) previously cultured at 25 ° C. for 7 to 14 days on a potato dextrose agar medium as a test bacterium, this was dispersed in physiological saline containing 0.005% by weight of dioctyl sodium sulfosuccinate, and a spore suspension It was created.

The spore suspension was dropped on the photocatalyst-coated body obtained by the above method so that the amount of the spore suspension was 4 to 6 × 10 ⁵ pieces / mL per one test piece to obtain an anti-mold test piece. In accordance with the film adhesion method described in JIS R1702 (2006), the test piece was covered with an adhesion film, placed in a petri dish capable of moisture retention, and moisturized glass was placed and used for the test.

The test piece was placed together with the petri dish under BLB light irradiation, and irradiated with BLB light for 24 hours so that the photocatalyst-coated body surface was 0.4 mW / cm ² .

  After 24 hours of irradiation, the spore suspension was collected and cultured on a potato dextrose agar medium, and the number of surviving bacteria was counted. The antifungal property was obtained by calculating the difference between the logarithmic value of the survival cell count obtained in Examples 29 to 34 and the logarithmic value of the survival cell count of the test specimen unprocessed with photocatalyst.

  The test results are shown in Table 6. Here, the antifungal activity value in the table is the value of the difference between the logarithmic value of the survival cell count obtained in Examples 29 to 34 and the logarithmic value of the survival cell count of the photocatalyst unprocessed test specimen, The larger the value, the higher the antifungal property. In the example produced using the Ag / Cu-containing titania aqueous dispersion, the antifungal activity value is higher than the example in which only the silver compound or only the copper compound is added. It was confirmed that high antifungal performance was obtained by mixing.

Examples 35 to 37: Evaluation of antifungal property by silver compound and copper compound-2
The photocatalyst coating body provided with the photocatalyst layer was manufactured as follows. First, a colored organic coated body was prepared as a base material. This colored organic coated body is obtained by applying general-purpose acrylic silicone to which a white pigment is added on a float plate glass and sufficiently drying and curing it. On the other hand, Ag / Cu-containing titania aqueous dispersion as a photocatalyst, water-dispersed colloidal silica as an inorganic oxide having an average particle size of 26 nm, water as a solvent, and a total amount of photocatalyst particles and inorganic oxide particles of 100 parts by mass 6 parts by mass of a polyether-modified silicone surfactant was mixed at a blending ratio shown in Table 7 to obtain a photocatalyst coating solution. This photocatalyst coating liquid does not contain hydrolyzable silicone. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass.

The obtained photocatalyst coating liquid was spray-coated on the colored organic coating body previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes. Thus, a photocatalyst layer was formed to obtain a photocatalyst-coated body. When the film thickness (μm) of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 1 μm in any of Examples 35 to 37. After pre-treatment of these photocatalyst-coated bodies with 1 mW / cm ² of BLB light for 24 hours, the following antifungal test was performed.

  About the photocatalyst coating body of a magnitude | size of 50x50 mm obtained in this way, antifungal evaluation was performed by the method similar to Examples 29-34.

  After 24 hours of irradiation, the spore suspension was collected and cultured on a potato dextrose agar medium, and the number of surviving bacteria was counted. Antifungal property was obtained by calculating the difference between the logarithmic value of the number of surviving bacteria obtained in Examples 35 to 37 and the logarithmic value of the number of surviving bacteria of the photocatalyst untreated specimen.

The test results are shown in Table 7. Here, the antifungal activity value in the table is the value of the difference between the logarithmic value of the survival cell count obtained in Examples 35 to 37 and the logarithmic value of the survival cell count of the photocatalyst untreated specimen, The larger the value, the higher the antifungal property. It was confirmed that high antifungal performance was obtained when the amount of [Ag ₂ O + CuO] was 0.5% by mass, 3% by mass, and 5% by mass with respect to the titanium oxide particles.

Example 38: Evaluation of harmful gas decomposability A photocatalyst-coated body provided with a photocatalyst layer was produced as follows. First, a colored organic coated body was prepared as a base material. This colored organic coated body is obtained by applying general-purpose acrylic silicone to which carbon black powder is added on a float plate glass and sufficiently drying and curing it. On the other hand, Ag / Cu-containing titania aqueous dispersion as a photocatalyst, water-dispersed colloidal silica as an inorganic oxide having an average particle size of 26 nm, water as a solvent, and a total amount of photocatalyst particles and inorganic oxide particles of 100 parts by mass 6 parts by mass of a polyether-modified silicone surfactant was mixed at a blending ratio shown in Table 8 to obtain a photocatalyst coating solution. This photocatalyst coating liquid does not contain hydrolyzable silicone. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass.

  The obtained photocatalyst coating liquid was spray-coated on the colored organic coating body previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes. Thus, a photocatalyst layer was formed to obtain a photocatalyst-coated body. When the film thickness (μm) of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 1 μm.

  About the photocatalyst coating body of the magnitude | size of 50x100 mm obtained in this way, the gas decomposability test was done by the method similar to Examples 8-11. The sample of Example 8 was subjected to the same measurement as a comparison.

  The obtained results were as shown in Table 8. Here, the NOx removal rate in the table is relatively shown with the removal amount of Example 8 being 100. As shown in Table 8, it was found that a sufficient removal rate could be obtained even when an Ag · Cu-containing titania aqueous dispersion as a photocatalyst was used.

Example 39: Evaluation of weather resistance A photocatalyst-coated body provided with a photocatalyst layer was produced as follows. First, a colored organic coated body was prepared as a base material. This colored organic coated body is obtained by applying general-purpose acrylic silicone to which carbon black powder is added on a float plate glass and sufficiently drying and curing it. On the other hand, Ag / Cu-containing titania aqueous dispersion as a photocatalyst, water-dispersed colloidal silica as an inorganic oxide having an average particle size of 26 nm, water as a solvent, and a total amount of photocatalyst particles and inorganic oxide particles of 100 parts by mass 6 parts by mass of a polyether-modified silicone surfactant was mixed at a blending ratio shown in Table 9 to obtain a photocatalyst coating solution. This photocatalyst coating liquid does not contain hydrolyzable silicone. The total solid concentration of the photocatalyst and the inorganic oxide in the photocatalyst coating solution was 5.5% by mass.

  The obtained photocatalyst coating liquid was spray-coated on the colored organic coating body previously heated to 50 ° C. and dried at 120 ° C. for 5 minutes. Thus, a photocatalyst layer was formed to obtain a photocatalyst-coated body. When the film thickness of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 0.5 μm.

  About the photocatalyst coating body of a magnitude | size of 50x100 mm obtained in this way, the weather resistance test was done by the method similar to Examples 1-7.

  The obtained results were as shown in Table 9. Here, G in the table indicates that there was almost no discoloration. As shown in Table 9, it was found that even if an Ag / Cu-containing titania aqueous dispersion as a photocatalyst was used or a photocatalyst layer was coated on an organic substrate, the weather resistance was sufficient.

Example 40: Evaluation of coating film adhesion A photocatalyst-coated body provided with a photocatalyst layer was produced in the same manner as in Example 38. When the film thickness of the photocatalyst layer was measured by observation with a scanning electron microscope, it was about 0.5 μm.

  About the photocatalyst coating body of a magnitude | size of 50x100 mm obtained in this way, coating-film adhesiveness was evaluated as follows. The photocatalyst-coated body was immersed in a calcium hydroxide saturated solution at 20 ± 5 ° C. After 7 days had elapsed, the surface was dried indoors, and then a cellophane tape was affixed to the surface. After holding the tape at one end and pulling it off in a direction perpendicular to the surface, the surface of the coating film is observed with a digital microscope. I understood.

Claims (15)

A photocatalyst-coated body comprising a substrate and a photocatalyst layer provided on the substrate,
The photocatalytic layer is
1 to 20 parts by mass of photocatalyst particles,
Inorganic oxide particles exceeding 70 parts by mass and 99 parts by mass or less;
The total amount of silica-converted amounts of the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone is 100 parts by mass with respect to 0 to 10 parts by mass of the hydrolyzable silicone dry matter in terms of silica. Including
In addition, containing copper element and silver element,
A photocatalyst-coated body in which gaps between particles exist in the photocatalyst layer.   The photocatalyst coating body of Claim 1 in which the said photocatalyst layer has a film thickness of 0.5 micrometer or more and 3 micrometers or less.   The surfactant is contained in an amount of 0 to less than 10 parts by mass with respect to 100 parts by mass of the total amount of the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone in terms of silica. The photocatalyst coating body of description.   The photocatalyst coating body as described in any one of Claims 1-3 in which the said photocatalyst layer contains the said photocatalyst particle 5-15 mass parts. The photocatalyst coating body as described in any one of Claims 1-4 whose said photocatalyst particle is a titanium oxide particle. The photocatalyst coating body as described in any one of Claims 1-5 whose said inorganic oxide particle is a silica particle.   The inorganic oxide has a number average particle size of more than 5 nm and less than 40 nm calculated by measuring the length of any 100 particles entering a 200,000-fold field of view with a scanning electron microscope. Item 7. The photocatalyst-coated body according to any one of items 1 to 6.   The photocatalyst coating body as described in any one of Claims 1-7 used as an exterior material. It is a photocatalyst coating liquid used for manufacture of the photocatalyst coating body as described in any one of Claims 1-8,
A solvent,
1 to 20 parts by mass of photocatalyst particles,
Inorganic oxide particles exceeding 70 parts by mass and 99 parts by mass or less;
Hydrolyzable silicone of 0 parts by weight or more and less than 10 parts by weight in terms of silica;
The photocatalyst coating liquid which contains copper element and silver element so that the total amount of the silica conversion amount of the said photocatalyst particle, the said inorganic oxide particle, and the said hydrolysable silicone may be 100 mass parts.   The surfactant is contained in an amount of 0 part by mass or more and less than 10 parts by mass with respect to 100 parts by mass of the total amount of silica equivalents of the photocatalyst particles, the inorganic oxide particles, and the hydrolyzable silicone. Photocatalyst coating solution.   The photocatalyst coating liquid according to claim 9 or 10, wherein the photocatalyst layer contains 5 to 15 parts by mass of the photocatalyst particles.   The photocatalyst coating liquid as described in any one of Claims 9-11 whose said photocatalyst particle is a titanium oxide particle.   The photocatalyst coating liquid as described in any one of Claims 9-12 whose said inorganic oxide particle is a silica particle.   The inorganic oxide has a number average particle size of more than 5 nm and less than 40 nm calculated by measuring the length of any 100 particles entering a 200,000-fold field of view with a scanning electron microscope. Item 14. The photocatalyst coating solution according to any one of Items 9 to 13.   The photocatalyst coating liquid according to any one of claims 9 to 14, wherein the solvent is water.