JP2000254449A - Base material for decomposing harmful or odor gas and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the adsorbing and removing efficiency of harmful material by forming a photocatalyst layer formed of a coating material composed of a photocatalyst powder deposied with metallic powder having no photocatalytic action and consisting of core powder having photocatalytic ability, a photocatalyst powder having adsorbability and a binder on the surface of a base material. SOLUTION: The photocatalyst powder, on which the metallic powder having no photocatalytic ability itself is deposited, and the photocatalyst powder having adsorbability are incorporated into the core powder having the photocatalytic ability. The photocatalytic layer is formed by applying the coating material prepared by mixing both photocatalyst powders with the binder on the base material and burning them. For example, outdoor air from which dust is previously captured by a dust collecting means 6 is passed through the base material irradiated with light by a light irradiating means 7 via a fan 2 while being made in contact with the base material. At this time, a part of the harmful material incorporated in the outdoor air being in contact with the base material 8 is decomposed and removed by the photocatalytic reaction, and is adsorbed in the base material 8, then the adsorbed harmful material is decomposed and removed by the photocatalytic reaction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a substrate and an apparatus for decomposing harmful or odorous gases (hereinafter, harmful substances). More specifically, the present invention relates to a substrate capable of decomposing harmful substances by light irradiation, and an apparatus using the substrate for decomposition.

[0002]

2. Description of the Related Art In the space where we live, there are many harmful substances such as cigarette smoke and exhaust gas emitted from automobiles. It is a problem. Therefore, it is desired to purify such harmful substances.

[0003] Generally, as a purification method, methods such as adsorption and removal using an adsorbent and decomposition and removal using an oxidation catalyst, ozone, and plasma are widely used.

[0004] However, the removal method using only the adsorbent has a problem that it is necessary to limit the amount of adsorption, desorb adsorbed components, and replace the adsorbent. Next, the use of plasma and ozone requires a high voltage, which limits the use and limits the amount of ozone generated.

[0005] In addition to the above general methods, the following removal methods have been reported.

Japanese Patent Application Laid-Open No. 7-16473 discloses an ethylene decomposition catalyst in which a photocatalytic layer is formed on an adsorption layer. However, since the photocatalyst layer covers the surface of the adsorption layer, sufficient adsorption performance cannot be obtained, and among the harmful substances adsorbed on the adsorption layer, decomposition by the photocatalyst layer is limited to the immediate vicinity of the photocatalyst layer. Would. Therefore, the removal efficiency was poor.

JP-A-1-189321, JP-A-1-189321
In JP-A-189322 and JP-A-1-234729, a photocatalyst is formed from a light source by forming a photocatalyst layer on the surface of an adsorbent, kneading a photocatalyst material in the adsorbent, or using a photocatalyst material that can be an adsorbent. An apparatus that removes harmful substances by irradiating light is disclosed. However, under an atmosphere in which a plurality of harmful substances exist (hereinafter, under an atmosphere of complex harmful substances), the removal efficiency and the catalyst regeneration efficiency were insufficient.

Japanese Patent Application Laid-Open No. 9-276378 discloses that a mixture of an adsorbent and a fine powder of a photocatalytic material is used for removing harmful substances. However, this was limited in application because it was merely mixed.

Japanese Patent Application Laid-Open No. 1-218635 discloses an adsorbent, a photocatalytic material, and C as a second component different from these.
A method for producing a deodorizing material obtained by mixing and sintering u, Zn, Sn, Ag, Pt and the like is disclosed. However, the photocatalytic materials described in this publication have insufficient photocatalytic ability.

Japanese Patent Application Laid-Open No. 1-252244 discloses a method for decomposing ethylene using a photocatalyst such as titanium oxide or titanium oxide carrying platinum. However, the removal efficiency was low with the photocatalyst alone.

In JP-A-8-117606, a photocatalyst layer containing a first metal element having a porous surface is formed,
A method of deodorizing using a photocatalytic film in which a second metal powder different from the first metal element smaller than the gap is immobilized in the gap between the photocatalyst layers is described. JP-A-9-1
Japanese Patent No. 68722 discloses a method for preventing contamination in a clean room by using titanium oxide or a photocatalytic material obtained by adding Pt, Ag, Pd, RuO ₂ , Co ₃ O ₄ or the like to titanium oxide. However, even these methods do not have sufficient removal efficiency.

[0012]

Thus, according to the present invention, the surface of the base material is composed of a core powder having photocatalytic ability carrying a fine powder of a metal or an oxide thereof having no photocatalysis itself. A substrate for decomposing harmful or odorous gas, comprising: a photocatalyst film formed of a coating material consisting essentially of a photocatalyst powder, a second photocatalyst powder exhibiting adsorption ability, and a binder. Is done.

Further, according to the present invention, there is provided an apparatus for decomposing harmful gas or odorous gas, comprising at least the above-mentioned substrate and means for irradiating the substrate with ultraviolet light.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the history of finding the present invention will be described.

In general, the photocatalyst is excited by irradiation with ultraviolet light or the like, and electrons existing in the valence band jump over the band cap and move to the conduction band. h ⁺ ) is formed and an oxidation reaction occurs, and one conduction band receives electrons (e ⁻ ) to cause a reduction reaction. Such a reaction is called a photocatalytic reaction.

Further, Cu, Ag,
A second metal having no catalytic action per se, such as Fe, Co, Pt, Ni, Pd, and Au, which is different from the first metal, is supported on the surface of a photocatalytic powder (core powder) having a photocatalytic reaction. The present inventors have found that the electron capturing effect of the second metal makes it possible to improve the reducing power of a core powder having a strong oxidizing power such as titanium oxide but a weak reducing power.

Here, there are two possible mechanisms for removing harmful substances in an atmosphere of complex harmful substances containing various harmful substances. The first is a mechanism in which harmful substances in the atmosphere in contact with the photocatalyst are sequentially decomposed by the above-described photocatalytic reaction, changed into other components, and removed. The second is a mechanism in which harmful substances are first adsorbed, and when the adsorbed harmful substances come into contact with a photocatalyst, they are decomposed by a photocatalytic reaction to be converted into other components and removed.

In the former case, the photocatalytic activity of the photocatalyst greatly affects the removal rate. However, this mechanism cannot sufficiently remove (deodorize) harmful substances derived from tobacco smoke and the like required in a real life environment. Thus, the present inventors have conducted intensive studies on a photocatalytic film using the latter mechanism, and as a result, have reached the present invention.

That is, the present inventor has proposed a first photocatalyst powder in which a metal powder having no photocatalyst itself is supported on a core powder having photocatalytic ability, and a second photocatalyst powder having an adsorption ability. A high-performance base material for decomposing harmful substances having high adsorptive power, high activity and high regenerative ability, including the body, was completed.

Next, the present invention will be described in detail.

As the core powder, any powder having the above-mentioned photocatalytic reaction can be used. For example, Ti, W, Mo, Si, In, Cd, Ga, Cr,
Metals such as Pb and Sn, and powders of alloys or oxides of these metals are exemplified. Furthermore, one or more of these powders may be used. Of these, titanium oxide powder is the most practical in terms of cost and safety. The crystal structure of titanium oxide may be any of anatase type and rutile type. In particular, the anatase type is suitable. The core powder is preferably a fine powder having a particle size of 100 nm or less. When the particle size is larger than 100 nm, the specific surface area becomes small, and the contact amount of the substance to be decomposed is reduced, which is not preferable. The particle size is more preferably from 5 to 100 nm, particularly preferably from 70 to 10 nm.

Next, fine powder is carried on the surface of the core powder. As fine powder, Cu, Ag, Fe, C
Metals such as o, Pt, Ni, Pd, and Au, or powders of oxides of these metals are exemplified. Furthermore, one or more of these powders may be used. The fine powder is preferably an ultrafine powder having a particle size of 10 nm or less. The particle size is more preferably 2 nm or less. The fine powder is preferably contained in the first photocatalyst powder in an amount of 0.1 to 10% by weight.

Examples of the method for supporting the fine powder on the core powder include a fixing method such as a light precipitation method, a mixing method, an impregnation method, a chemical deposition method, and a simultaneous deposition method.

If the particle size of the core powder is small and the particle size of the fine powder is large, the fine powder covers the core powder, so that the movement path of e ⁻ and h ⁺ is cut off. . Therefore, in the photocatalyst powder, it is preferable to appropriately set the respective particle diameters so as to maintain the movement path of e ⁻ and h ⁺ . The specific particle size depends on the application, but generally in the gas phase,
More preferably, the core powder has a particle size of about 10 to 100 nm, and the fine powder has a particle size of about 2 nm or less.

Next, since only the first photocatalyst powder has a low adsorptivity, only the harmful substances in contact with the first photocatalyst powder can be decomposed and removed. Therefore, a second photocatalyst powder having an adsorption ability is added. By adding the second photocatalyst powder, a harmful substance directly contacted with the first photocatalyst powder,
Both harmful substances adsorbed on the second photocatalyst powder can be decomposed and removed. Therefore, in addition to the improvement of the removal efficiency of harmful substances, the removal efficiency can be further improved because the photocatalyst powder having the adsorption ability is used. More specifically, as the second photocatalyst powder, Ti, W, Mo, S
Metals such as i, In, Cd, Ga, Cr, Pb, and Sn, and powders of alloys or oxides of these metals can be used. Further, one or more of these powders can be used. Here, the second photocatalyst powder is preferably a fine powder having a particle size of 50 nm or less and a specific surface area of 50 m ² / g or more. In particular, the particle size is about 10 nm or less and the specific surface area is 15
It is preferably 0 m ² / g or more.

Further, when only the first and second photocatalyst powders are used, in the atmosphere of the composite harmful substance, the component which is inferior to the decomposition adsorbs on the surface of the second photocatalyst powder and blocks the surface. As a result, the original function may be impaired. Therefore, it is preferable to use the following adsorbent having lower adsorption characteristics than the second photocatalyst powder. The use of the adsorbent enables high-performance removal even in an atmosphere of complex harmful substances.

Examples of the adsorbent include single or composite materials such as silica gel, silicalite, activated carbon and zeolite. Considering the harmful substance adsorption performance, a hydrophobic zeolite (Si / Al = 50 or more) is suitable for the adsorbent. Here, the zeolite converts some of the hydrogen atoms or sodium atoms contained therein into Cu, Ag, F
e-exchanged zeolite substituted with e, Co, Pt, Ni, Pd, Au, etc. (M = Cu, Ag, Fe, Co, Pt, N
i, Pd, Au, etc.). By using this zeolite, the adsorptivity can be further improved, and as a result, highly efficient removal can be realized.

The mixing amount of the second photocatalyst powder depends on the amount of the second
Can be appropriately set depending on the type and performance of the photocatalyst powder, but is preferably about 1 to 70% by weight based on the first photocatalyst powder. The mixing amount of the adsorbent can be appropriately determined depending on the type and performance of the adsorbent to be used, but is preferably about 1 to 70% by weight based on the first photocatalyst powder.

The M-exchanged zeolite has a C content therein.
Since u, Ag, Fe, Co, Pt, Ni, Pd, and Au exhibit an electron trapping effect, they tend to inhibit the reduction reaction of the first and second photocatalyst powders. Therefore, for the purpose of suppressing this effect, it is preferable to simultaneously mix an appropriate amount of solid base powder such as calcium oxide, calcium carbonate, potassium oxide, and sodium hydroxide.

The photocatalyst film comprises the first and second photocatalyst powders,
It is formed by mixing with a binder to form a coating, applying the coating on a substrate, and firing. As the binder, organic binders such as silicone resin and fluororesin, colloidal silica, titanium oxide, SiO
An inorganic binder mainly composed of ₂ or the like can be used. The binder may include a solvent as desired. It is preferable that the mixing ratio of the binder is adjusted so that the first photocatalyst powder is in a range of about 20 to 80% by weight based on the solid content of the binder. By selecting a binder containing SiO ₂ as a main component and having a small amount of impurities, a photocatalytic film can be formed without deteriorating the photocatalytic ability.

Here, the photocatalytic activity may be impaired by the influence of the solid acid substance contained in the binder. Therefore, in order to pseudo-neutralize these solid acid substances, appropriate amounts of solid base powders such as calcium oxide, calcium carbonate, potassium oxide and sodium hydroxide may be mixed at the same time.

When an inorganic binder is used, there is a possibility that the grain boundary strength of the formed photocatalyst film is weakened and the film strength is deteriorated. In order to increase the grain boundary strength, one or both of inorganic powders such as mica (hydrous potassium aluminum silicate) and wet talc (natural hydrous magnesium silicate) having a plate-like or chain-like crystal structure may be added. Good. The amount of the inorganic powder added is preferably about 50% by weight or less based on the inorganic binder.
Further, by mixing this inorganic powder, the obtained photocatalyst film becomes porous, and the photocatalytic ability after film formation can be further improved.

However, if a solid acid substance is contained in such an inorganic powder, the photocatalytic activity may be impaired by the influence of the solid acid substance. Therefore, as in the case of the binder, the solid acid substance is pseudo-neutralized (meaning that it is not strictly neutralized but neutralized as a whole photocatalytic film).
For this purpose, a solid base substance such as calcium oxide, calcium carbonate, potassium oxide, or potassium hydroxide may be added.

The amount of the solid base substance to be mixed depends on other mixed substances such as a binder to be used and the type of the solid base substance, and should be adjusted in consideration of the amount of the solid acid substance contained in the mixed substance. Can be. Specifically, in the case of calcium oxide, it is preferably 0.5% by weight or less in the coating material, and in the case of calcium carbonate, it is preferably 1% by weight or less.

Further, when preparing various materials, additives such as a dispersant and a surfactant may be mixed in order to uniformly disperse and stabilize the paint. Also at this time, when a substance having an electron capturing effect such as a solid acid substance is included in each additive, it is preferable to mix an appropriate amount of a solid base substance to form a coating material.

As long as the substrate can form a photocatalytic film, the material, shape and structure can be appropriately selected according to the purpose of use. The method for forming the photocatalyst film is not particularly limited, and any known method can be used.

As the base material, glass, metal, ceramic, plastic fiber and the like can be mentioned. The shape of the substrate is not particularly limited, and examples thereof include a plate shape, a linear shape, and a tubular shape.

The photocatalyst film is formed by applying a coating containing each of the above-mentioned components to the surface of a substrate by a method such as spray coating, dip coating, roll coating, spin coating, brush coating, etc., and firing at a relatively low temperature of 400 ° C. or less. Can be formed. The firing temperature is more preferably 200 ° C. or lower. If necessary, a preliminary drying step may be performed before firing. However, when the base material is plastic, a binder that can be dried at room temperature to 70 ° C. (for example, a silica binder manufactured by Colcoat)
It is preferable to use Incidentally, the photocatalytic film of the present invention,
It is preferable to have a thickness of 20 to 1 μm depending on the application.

The harmful substances in the present invention include organic and inorganic harmful gases and / or odorous gases emitted from tobacco, automobiles and the like, and more specifically, ammonia, xylene, pyridine, acetaldehyde, styrene and the like. And inorganic gases such as nitrogen monoxide and nitrogen dioxide.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the photocatalyst film of the present invention and a product to which the photocatalyst film is applied will be described in more detail with reference to the accompanying drawings, but the present invention is not limited to these embodiments. (1) Hazardous substance removal test Platinum-supported titanium oxide powder (first photocatalyst powder) manufactured by Daiken Chemical Co., Ltd., and Nissan were placed in four 27-liter acrylic containers equipped with a blower fan. Titanium oxide powder (photocatalyst powder), platinum-supported titanium oxide powder + titanium oxide powder (first and second photocatalyst powders), platinum-supported titanium oxide powder + Cu-exchanged pentazil powder manufactured by Chemical Co., Ltd. 0.5 g of each sample of the body (first and second photocatalyst powders) was placed, and one cigarette (Mild Seven, manufactured by Japan Tobacco Inc.) was burned. After burning, it was allowed to stand for about 30 minutes, and then irradiated with ultraviolet light with black light for about 30 minutes.
One minute after the burning of the tobacco, the initial value was set, and after 60 minutes (leaving for about 30 minutes → irradiating with ultraviolet rays for about 30 minutes), the treatment was terminated.
With respect to each sample, various harmful substances were measured for each lapse of time using a detector tube. The test results are shown in FIG.

As can be seen from FIG. 1, the adsorption ability was low only with the platinum-supported titanium oxide powder. On the other hand, in the case of using only the titanium oxide powder, the removal rates of acetaldehyde and acetic acid were larger than in the case of using only the titanium oxide powder carrying platinum. In addition, when the platinum-supported titanium oxide and the adsorbent were mixed, it was confirmed that the removal rate of harmful substances was greatly increased. In addition, when titanium oxide was used as the second photocatalyst powder, it had a wide range of removal characteristics in an atmosphere of complex harmful substances, but the removal characteristics were inferior to those when mixed with the second photocatalyst powder. (2) Example of manufacturing photocatalyst film Snowtex O manufactured by Nissan Chemical Industries, Ltd. (main component:
Colloidal silica 20.5% by weight) (binder)
In 100 g, platinum (particle diameter 1.5 n) was formed on the surface of rutile titanium oxide (particle diameter 70 nm) manufactured by Daiken Chemical Industry Co., Ltd.
20.5 g of the first photocatalyst powder supporting m) was mixed. Then, # 5500 mica powder manufactured by Wakita Mining Co., Ltd. (chemical name: hydrous aluminum potassium silicate, main component:
5.125 g of SiO ₂ -about 43.3% by weight, Al ₂ O ₃ -about 41.9% by weight (inorganic powder for enhancing grain boundary strength) are mixed, and further calcium carbonate powder (solid base substance) Was mixed to prepare a photocatalyst coating material A.

As the second photocatalyst powder in 125.67625 g of the photocatalyst coating material A, titanium oxide (particle diameter: 7 nm) manufactured by Ishihara Sangyo Co., Ltd.
Photocatalytic paints B and C were prepared by mixing 20.5 g of each of the exchanged pentazils.

The photocatalyst paints A, B and C thus prepared
Was degreased with acetone on an aluminum substrate (60
× 160 mm, the surface of which has been subjected to chromate treatment), spray-coated, baked at 200 ° C. and has a photocatalytic film for decomposing harmful or odorous gases X, Y, Z
Was prepared. (3) Acetaldehyde decomposition test After the two substrates X, Y, and Z prepared in the above item (2) were respectively placed in an acrylic container having a capacity of 27 liters in which a blower fan was placed, acetaldehyde was placed in the container. 100 ppm was injected. After stirring the air in the container for about 1 minute, the change in concentration with time was measured using a detector tube. The results are shown in FIG.

As shown in FIG. 2, the base material Z had poor acetaldehyde decomposition activity. Although the reason for this has not been clarified yet, it is considered that the reducing power of the photocatalytic film is suppressed by the electron capturing effect of Cu contained in the adsorbent. Therefore, in order to increase the activity of the substrate Z, it is considered that it is necessary to further add a solid base substance.

On the other hand, the base material Y has almost the same acetaldehyde decomposition activity as the base material X. Here, the activity of the base material Y is slightly inferior to that of the base material X because the amount of platinum-supported titanium oxide exposed on the surface of the film is smaller in the base material Y than in the base material X (irradiation with ultraviolet rays). The surface area of the platinum-supported photocatalyst powder is small. For this,
The problem can be solved by preparing a porous and uniformly dispersed photocatalyst film by adjusting the mixing amount of the inorganic powder (mica powder) or mixing a dispersant. (4) Embodiment of Apparatus Using Photocatalytic Film FIG. 3 is a schematic diagram showing an example of the internal configuration of an apparatus using the harmful or odor gas decomposition substrate of the present invention. This device has a fan 2 for circulating outside air into the device 1 in a main body 1.
And an operation panel unit 5 that arranges an intake port 3 and an exhaust port 4 in the main body 1 with the fan 2 interposed therebetween and controls various operations. In this device, the outside air is circulated from the intake port 3 to the exhaust port 4 by the fan 2, but in the following description, it will be referred to as upstream and downstream with respect to the flowing direction of the circulating outside air.

In the main body 1, dust collecting means 6 for collecting dust in the outside air is disposed between a downstream portion of the intake port 3 and an upstream portion of the fan 2, and a downstream portion of the fan 2 and an exhaust port 4 are provided. The light irradiation means 7 and the base material 8 are provided in this order between the upstream portions.

The dust collecting means 6 includes a filter using an electric means such as an electric dust collector, a HEPA (high-efficiency particle adsorption) filter, an activated carbon filter, and the like. These filters may be used alone or in combination. May be.

The light irradiating means 7 is arranged so as to illuminate the substrate 8 vertically and evenly, and includes a cold cathode tube, a black light, a white light and the like. Among them, those having higher ultraviolet intensity are more suitable for utilizing the photocatalysis.

Next, the operation configuration of this device will be described. In the outside air, dust contained therein is captured by the dust collecting means 6. Then, the light passes through the fan 2 while being in contact with the substrate 8 to which light is irradiated by the light irradiation means 7 and is exhausted. At this time, a part of the harmful substances contained in the outside air in contact with the base material 8 is decomposed and removed by the photocatalytic reaction, and a part of the harmful substances is adsorbed by the adsorbent in the base material 8.
The adsorbed harmful substances are subsequently decomposed and removed by a photocatalytic reaction.

FIG. 4 shows a modification of the apparatus shown in FIG.
In FIG. 4, the air is exhausted by circulating the dust collecting means 6, the light irradiating means 7, the substrate 8, and the fan 2 from the upstream side. The operation of this apparatus and the method of decomposing and removing harmful substances are the same as the layer values in FIG.

The configuration of the apparatus of the present invention is not limited to the configurations shown in FIGS. 3 and 4 as long as it has at least the substrate and the means for irradiating the substrate with ultraviolet light. Can take. Further, the device of the present invention can be used not only for an air purifier but also for a deodorizing device attached to a refrigerator, an air conditioner, or the like.

[0052]

According to the present invention, when a photocatalytic film is used for decomposing and removing harmful substances in an atmosphere of complex harmful substances such as cigarette smoke,
In the photocatalytic film composed of only the first photocatalyst powder carrying the fine powder (not including the second photocatalyst powder having the adsorbing ability), only the contacted harmful substances were decomposed, and the removal efficiency was poor. However, according to the present invention, the second photocatalyst powder having the adsorptivity is further included, so that the removal efficiency is excellent.

Further, by selecting the particle size and specific surface area of the first and second photocatalyst powders, the photocatalyst film can be made porous, so that the contact area with harmful substances can be increased. Further, by adding an inorganic powder to enhance the grain boundary strength of the photocatalytic film, by adding a solid base substance for pseudo-neutralization of the solid acid substance contained in the photocatalytic film, or by adding a dispersant, A substrate having a photocatalytic film that can decompose and remove organic substances with high efficiency and can regenerate with high efficiency can be formed.

As a secondary effect of the present invention, reduction in power consumption, and antibacterial and antifungal properties can be expected by selecting a powder containing a metal such as Ag, Pt, or Au as the core powder.

[Brief description of the drawings]

FIG. 1 is a graph showing the removal rates of various harmful substances of a first photocatalyst powder and first and second photocatalyst powders of an example.

FIG. 2 is a graph showing the acetaldehyde decomposing activity of the substrate of Example over time.

FIG. 3 is a schematic view of an apparatus for decomposing and removing harmful substances using a substrate according to the present invention.

FIG. 4 is a schematic view of an apparatus for decomposing and removing harmful substances using a substrate according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 2 Fan 3 Intake port 4 Exhaust port 5 Operation panel part 6 Dust collection means 7 Light irradiation means 8 Base material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 23/16 B01J 23/16 A 23/38 23/38 A 23/72 23/72 A 23/74 23 / 74 A 35/02 35/02 J B01D 53/36 HF term (reference) 4D048 AA17 AA19 AA22 AB03 AB05 BA05Y BA06Y BA07X BA11Y BA13X BA16Y BA17Y BA20Y BA21Y BA25Y BA26Y BA27Y BA30X BA34Y BA35X BA38Y BA39 CC40CC DA11 DA20 EA01 EA04 4G069 AA03 AA09 BA02A BA02B BA04A BA04B BA07A BA07B BA08A BA11A BA11B BA16A BA18 BA22C BA47A BA48A BB01A BB02A BB02B BB04A BB05A BB16A BB16B BC02A BC03A BC09A BC09B BC17A BC18A BC21A BC22A BC26A BC31A BC31B BC32A BC33A BC36A BC50A BC58A BC59A BC60A BC66A BC67A BC68A BC72A BC75A BC75B BD05A BE32C BE34C CA10 CA17 EA01X EA07 EB18X EB19 EC02X EC03X EC04X EC05X EC22X EC22Y EC28 ED03 FC05 FC08 ZA10B ZA36A ZD01

Claims (19)

[Claims] 1. A first photocatalyst powder comprising a core powder having a photocatalytic ability carrying a fine powder of a metal or an oxide thereof which does not itself have a photocatalytic action, and exhibiting an adsorbing ability. A substrate for decomposing harmful or odorous gas, comprising a photocatalyst film formed from a paint essentially consisting of a second photocatalyst powder and a binder. 2. The substrate according to claim 1, wherein the core powder has a particle size of 100 nm or less. 3. The core powder is made of Ti, W, Mo, Si, I
The base material according to claim 1, wherein one or more types are selected from powders of metals of n, Cd, Ga, Cr, Pb, and Sn, alloys of these metals, and oxide powders. 4. The fine powder is composed of Cu, Ag, Fe, Co, P
The substrate according to any one of claims 1 to 3, wherein one or more kinds are selected from powders of metals of t, Ni, Pd, and Au and oxides of these metals. 5. The substrate according to claim 3, wherein the core powder is an anatase-type or rutile-type titanium oxide powder having a particle size of 5 to 100 nm, and the fine powder has a particle size of 10 nm or less. 6. The photocatalyst powder according to claim 1, wherein the second photocatalyst powder is contained in a proportion of 1 to 70% by weight based on the first photocatalyst powder.
The substrate according to any one of the above. 7. The method of claim 2, wherein the second photocatalyst powder is Ti, W, Mo,
The group according to any one of claims 1 to 6, wherein one or more kinds are selected from powders of metals of Si, In, Cd, Ga, Cr, Pb, and Sn, alloys of these metals, and oxides. Wood. 8. The substrate according to claim 7, wherein the second photocatalyst powder is a powder having a particle size of 50 nm or less and a specific surface area of 50 m ² / g or more. 9. The substrate according to claim 7, wherein the second photocatalyst powder is an anatase type or rutile type titanium oxide having a particle size of 50 nm or less. 10. The base material is silica gel, silicalite,
Activated carbon, zeolite or M-exchanged zeolite (M = C) in which some of the elements constituting zeolite are exchanged for metal ions
u, Ag, Fe, Co, Pt, Ni, Pd, Au, S
The substrate according to any one of claims 1 to 9, comprising one or more adsorbents selected from b). 11. A photocatalyst film comprising a first and second photocatalyst powder and a coating composed of a silicone resin, a fluororesin, colloidal silica, a binder containing silicon oxide or titanium oxide as a main component, and sintering the substrate. The base material according to any one of claims 1 to 10, wherein the base material is formed by coating, and the binder is contained in the coating material in an amount of 20 to 80% by weight. 12. The coating material is used for enhancing the grain boundary strength of the photocatalyst film, and further includes an inorganic powder having a plate-like or chain-like structure, wherein the inorganic powder accounts for 50% by weight or less of the binder. The substrate according to claim 11, which is included in: 13. The substrate according to claim 12, wherein the inorganic powder is mica, wet talc, or both powders having an average particle size of 50 μm or less. 14. The substrate according to claim 12, wherein when the binder or the inorganic powder contains a solid acid substance, the base substance contains an amount of a solid base substance capable of pseudo-neutralizing the solid acid substance. 15. The solid base substance is selected from calcium oxide, calcium carbonate, potassium oxide and sodium hydroxide.
The base material according to claim 14, wherein one or more kinds are selected. 16. The substrate according to claim 15, wherein the solid basic substance is calcium oxide, and the calcium oxide is contained in the photocatalytic coating in an amount of 0.5% by weight or less. 17. The substrate according to claim 15, wherein the solid base substance is calcium carbonate, and the calcium carbonate is contained in the photocatalytic coating in an amount of 1% by weight or less. 18. The substrate according to claim 11, wherein the coating material contains 10% by weight or less of a dispersant. 19. An apparatus for decomposing harmful gas or odor gas, comprising at least the substrate according to claim 1 and means for irradiating the substrate with ultraviolet light.