JP2001009295A - Photocatalyst body, lamp and lighting fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the adhesion property of a photocatalyst film to a base body by improving the formation of a photocatalyst film by coating with a dispersion liquid of ultrafine particles, to provide a photocatalyst having good transmittance for light, and to provide a lamp and a lighting fixture using this photocatalyst. SOLUTION: The photocatalyst consists of a base body 1, a base layer 2 formed on the base body 1, and a photocatalyst film 3 formed on the surface of the base layer 2. The base layer 2 essentially consists of at least one kind of oxide fine particles 2b selected from aluminum, zirconium and silicon, and a silicon compd. The average particle size of the oxide fine particles 2b ranges from 10 to 40 nm, and the molar ratio of the oxide fine particles is 40 to 90%. The photocatalyst film 3 essentially consists of titanium oxide ultrafine particles having a smaller average particle size than the oxide fine particles 2b. By this method, the film forming property and wettability of the photocatalyst film 3 can be improved and the film strength can be increased. Since absorption of UV rays by the base layer 2 is low, the use efficiency of UV rays by the photocatalyst film 3 can be increased to improve the photocatalyst effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photocatalyst, a lamp using the same, and a lighting apparatus.

[0002]

2. Description of the Related Art It is known to use a photocatalytic film for deodorizing, antifouling and / or antibacterial.

When a photocatalytic film is irradiated with ultraviolet rays and absorbs its light energy, electrons and holes are generated in a semiconductor which forms the photocatalytic film and exhibits a photocatalytic action. The electrons and holes are said to react with oxygen and water on the film surface to generate active oxygen and other active radicals, and to decompose organic dirt and odor components by redox reduction.

[0004] Among the photocatalytic substances, titanium oxide is currently the most promising. Titanium oxide is
This is because the substance has a remarkable photocatalytic action, is safe, is industrially reasonable, and can be obtained in a required amount.

In recent years, attention has been paid to the usefulness of photocatalytic films, and there is an active movement to form photocatalytic films on a wide range of articles such as building materials, lighting fixtures and lamps.

Although there are various methods for producing a photocatalyst film, a so-called dip method and an ultrafine particle dispersion coating method are generally used.

In the so-called dip method, a metal alkoxide constituting a photocatalyst film is coated on a substrate. For example, when the photocatalyst film is titanium oxide, a coating solution containing a titanium alkoxide is applied and fired at a temperature of 400 to 500 ° C. This is a method of forming a photocatalyst film by using The photocatalytic film obtained by this production method has excellent durability and durability.

In the ultrafine particle dispersion coating method, a water-soluble dispersion in which photocatalytic ultrafine particles such as titanium oxide are dispersed in a solution composed of water, alcohol, or the like is applied to a substrate and baked to obtain a photocatalytic film. Is the way. The photocatalytic film obtained by this manufacturing method has high crystallinity and excellent photocatalytic properties.

[0009]

The photocatalytic film obtained by the so-called dip method must be fired at a high temperature for a long time,
There is a problem that the crystallinity on the film surface is not sufficient and the photocatalytic property is low. When the substrate is a soft glass such as soda-lime glass, the glass cannot be fired at a required high temperature because the softening temperature of the glass is relatively low, so that it is difficult to obtain a sufficient photocatalytic property.

When a photocatalyst film is formed by the above-described method, the refractive index of the photocatalyst film mainly composed of titanium oxide is larger than the refractive index of glass. There is also a problem that the visible light transmittance is reduced.

In order to solve these problems in the dipping method, the applicant has first added a metal oxide such as silica to the photocatalyst film to reduce the refractive index of the photocatalyst film and to reduce the refractive index of the photocatalyst film and the glass of the substrate. Japanese Patent Application No. 9-1 to make them almost equal
No. 40372. According to the invention of this application,
The addition of the metal oxide reduced the refractive index of the photocatalyst film, thereby preventing a decrease in light transmittance and preventing the occurrence of interference colors.

On the other hand, in the ultrafine particle dispersion coating method, it is difficult to obtain sufficient adhesion to a substrate, and when an organic binder is used, cracks tend to occur in the binder. When a crack occurs in the binder, there is a problem that the transmittance decreases due to cloudiness or the like.

The present invention improves the photocatalytic film formation by the ultrafine particle dispersion coating method, improves the adhesion of the photocatalytic film to the substrate, and provides a photocatalyst having good light transmittance, a lamp and an illumination using the same. Its main purpose is to provide equipment.

[0014]

The photocatalyst of claim 1 is:
A base; at least one oxide fine particle selected from the group consisting of aluminum, zirconium, and silicon and a silicon compound as a main component, wherein the oxide fine particles have an average particle size of 10 to 60 nm and a molar ratio of 40;
An underlayer formed on the substrate so as to be 90% or less;
And a photocatalyst film formed on the surface of the underlayer mainly composed of ultrafine titanium oxide particles having an average particle diameter smaller than the oxide fine particles.

According to a second aspect, in the photocatalyst according to the first aspect, the titanium oxide ultrafine particles of the photocatalyst film have an average particle size of 4 to 4.
The thickness is 10 nm.

A third aspect of the present invention is the photocatalyst according to the first or second aspect, wherein an average linear transmittance of visible light of the composite layer including the underlayer and the photocatalyst film is 90% or more.

A fourth aspect of the present invention is the photocatalyst according to any one of the first to third aspects, wherein the ultrafine titanium oxide particles of the photocatalyst film are mainly composed of anatase crystals.

According to a fifth aspect of the present invention, in the photocatalyst according to any one of the first to third aspects, the ultrafine particles of titanium oxide in the photocatalytic film are a mixture of anatase crystal and rutile crystal.

According to a sixth aspect of the present invention, in the photocatalyst according to any one of the first to fifth aspects, ultrafine particles of titanium oxide of the photocatalyst film are soaked in the underlayer.

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

(About the substrate)

The substrate supports the photocatalyst film and is formed not only for the purpose of supporting the photocatalyst film but also for other functions which are not originally intended for the support of the photocatalyst (hereinafter, referred to as “substrate”). "Functional material").

Examples of the functional material include various optional materials such as building materials such as tiles, window glasses, and ceiling panels, kitchen and sanitary equipment, home appliances, lighting equipment, deodorizing or dust collecting filters, and the like. Can be used as a substrate.

As the material of the base, metal, glass, ceramics (including porcelain), pottery, stone, synthetic resin, wood and the like are allowed.

When the photocatalytic film is formed by firing the photocatalyst film at a high temperature, the substrate must have heat resistance enough to withstand the firing.

(Regarding Underlayer)

In the present invention, the photocatalyst film is formed on the substrate via the underlayer without directly adhering to the surface of the substrate. The underlayer is mainly composed of at least one kind of oxide fine particles selected from the group consisting of aluminum (Al), zirconium (Zr), and silicon (Si), and a silicon compound, in which metal oxide fine particles contained in the underlayer are selected from the group consisting of aluminum (Al), zirconium (Zr), and silicon (Si). The average particle size of the oxide fine particles is in the range of 10 to 60 nm.
In addition, the molar ratio (mol
%) Is in the range of 40-90%. The average particle size of the oxide fine particles can be determined by averaging the primary particle size of the oxide fine particles present in the cross section of the underlayer observed by an electron microscope or the like, and the molar ratio can be determined by SIMS.

It is preferable that the surface of the underlayer, especially on the photocatalytic film side, is porous. For example, the underlayer may have an uneven surface which does not optically reduce the transmittance. Since the underlayer is mainly composed of oxide fine particles, the underlayer has good compatibility with the photocatalyst film containing titanium oxide as a main component, and can be firmly bound to the substrate by firing.

Preferably, the average particle diameter of the oxide fine particles contained in the underlayer is 10 to 40 nm and the molar ratio thereof is 40 to 90%. It has been found that under these conditions, the linear transmittance of visible light can be further increased, and ultraviolet absorption of the underlayer can be almost eliminated. Therefore, the photocatalyst provided with such an underlayer has high optical characteristics and can obtain a high photocatalytic effect.

The oxide fine particles of the underlayer are made of aluminum (A
l) In the case of an oxide selected from a material other than the group consisting of zirconium (Zr) and silicon (Si), the stability of the underlayer cannot be ensured, the refractive index of the underlayer increases, and the occurrence of light interference occurs. Thus, there are problems such as a decrease in visible transmittance and an underlayer absorbing ultraviolet rays.

The average particle diameter of the oxide fine particles in the underlayer is 10 n.
If it is less than m, the wettability of the photocatalyst film is deteriorated, and the strength of the photocatalyst film is reduced, the photocatalyst film is easily peeled off, and the adhesion to the underlayer is deteriorated. On the other hand, if the average particle size exceeds 60 nm, the total transmittance of visible light is good but the light tends to be diffused, and there is a problem that the linear transmittance is reduced. If the amount of the oxide fine particles is less than 40 mol%, the adhesion of the photocatalytic film to the underlayer tends to decrease, and if it exceeds 90 mol%, the strength of the underlayer and the linear transmittance tend to decrease. When the average particle diameter of the titanium oxide ultrafine particles constituting the photocatalyst film is less than the average particle diameter of the oxide fine particles in the underlayer, the organic substance decomposition characteristics in the photocatalytic effect are reduced.

Further, the metal oxide constituting the underlayer is
For example, the occurrence of light interference can be suppressed or anti-reflection can be achieved by forming a gradient structure with a middle refractive index between a substrate having a small refractive index and a photocatalytic film having a large refractive index, such as soda lime glass. An effect can be provided.

The underlayer can be formed, for example, by preparing a coating solution prepared by diluting oxide particles and a silicon compound such as polysiloxane with an organic solvent, applying the coating solution to a substrate, and baking.

It is desirable that the visible average linear transmittance of the underlayer is 90% or more. This is the same for the photocatalytic film. As a result, when a substrate having a high visible light transmittance such as glass is used, the amount of visible light transmitted through the underlayer and the photocatalyst layer hardly decreases. The present invention can also be applied.

This visible average linear transmittance is the transmittance of only two layers excluding the reflection and absorption at the substrate. For example, when the substrate is glass, a substrate glass without a layer is placed as a reference to measure the transmission characteristics. In the case of a reflecting member, the base of the layerless reflecting member as a reference may be similarly put, and the reflection characteristics may be measured and converted.

(Photocatalyst film)

The photocatalytic substance contains titanium oxide (TiO ₂ ) as a main component. Titanium oxide, which has a remarkable photocatalytic action, is safe, industrially reasonable, and can be obtained in a required amount, is currently regarded as the most promising photocatalytic substance.

Further, titanium oxide has rutile crystal and anatase crystal as its crystal structure. It is said that the anatase form is superior in photocatalysis.

Therefore, in the present invention, it is preferable to use titanium oxide of anatase crystal. But,
Actually, rutile crystals are often mixed with anatase crystals.Moreover, when ultrafine particles of titanium oxide are used, practical photocatalysis can still be obtained. A mixed aspect of both is allowed. Further, the decomposability of the organic matter changes depending on the mixing ratio.

Further, in the present invention, a photocatalyst substance other than titanium oxide may be added as a subcomponent in the photocatalyst film. Other photocatalytic materials include the following. WO ₃ , LaRhP ₃ , FeTiO ₃ , Fe ₂ O
₃ , CdFe ₂ O ₄ , SrTiO ₃ , CdSe, GaAs,
GaP, RuO ₂ , ZnO, CdS, MoS ₃ , LaRh
O ₃ , CdFeO ₃ , Bi ₂ O ₃ , MoS ₂ , In ₂ O ₃ , C
dO, SnO ₂ and the like. These substances can be used alone or in combination of two or more.

Note that TiO_Two, WO_Three, SrTiO_Two, F
e_TwoO_Three, CdS, MoS_Three, Bi_TwoO_Three , MoS_Two, In_Two
O_Three, CdO, etc. are equivalent electronic band redox potentials
Is the absolute value of the conduction band redox potential
Oxidizing power is larger than reducing power because it is larger than logarithmic value
Deodorizing action, antifouling action or
Excellent antibacterial action.

Among the above substances, Fe ₂ O ₃ and ZnO are superior in terms of raw material cost.

Further, in the present invention, the titanium oxide is used in the form of ultrafine particles. The ultrafine particles are extremely fine particles having an average particle size of 4 to 10 nm, and are preferably fine particles having a shape as close to a spherical shape as possible, with a small variation in particle size and good crystallinity.

Further, when the photocatalytic film has irregularities on the surface of the underlayer, it is possible to partially enter the irregularities and adhere to the irregularities.

Further, when the underlayer of the present invention is formed of a porous material, the ultrafine particles of titanium oxide of the photocatalytic film partially permeate not only the surface of the underlayer but also the inside thereof. The term "soak" means that the ultrafine particles of titanium oxide penetrate between the ultrafine particles of the underlayer at a depth not less than the average particle diameter of the fine particles of the underlayer. Therefore, titanium oxide having a high refractive index is substantially mixed in the underlayer, and the refractive index of the underlayer is adjusted so as to approach the refractive index of the photocatalytic film. As the ratio of the titanium oxide ultrafine particles increases from the substrate side of the underlayer toward the surface side of the underlayer, the refractive index of the underlayer continuously changes, and the refractive index difference at the interface causes Optical interference is suppressed.
In addition, since the ultrafine particles of titanium oxide permeate into the underlayer, it is possible to firmly adhere.

The firing is performed at 150 ° C. or more, for example, at 30 ° C.
It can be performed in the range of 0 to 600 ° C.

Further, a trace amount of silicon dioxide, aluminum oxide, zirconium oxide or silicone can be added to the photocatalyst film. These act as binders.

Since the photocatalyst film is mainly composed of ultrafine particles of titanium oxide, it has a strong photocatalytic action similarly to a conventional photocatalyst film using ultrafine titanium oxide particles.

(Operation of the Present Invention)

The photocatalyst of the present invention having the above-described structure has the following effects.

(1) Good photocatalytic action.

High photocatalysis can be obtained by the ultrafine particles having good crystallinity.

(2) The strength of the photocatalyst film is large.

Ultrafine titanium oxide particles are adhered to the surface of the underlayer made of fine oxide particles having good adhesion, and the titanium oxide ultrafine particles partially penetrate into the porous underlayer. The adhesion of the film is good, and the photocatalytic film has high strength.

(3) The underlayer and the photocatalytic film have high transmittance in the visible light region.

Since an underlayer having an apparent lower refractive index than that of porous titanium oxide is formed on the surface of the substrate, light reflection is reduced between the glass substrate and the photocatalytic film, and visible light is transmitted. When the glass is used for the substrate, the visible light transmittance is equal to or higher than that of the glass of the fabric.
When the underlying layer is porous, a part of the titanium oxide ultrafine particles permeates the underlying layer, and the interface is non-uniform, so that the visible light transmittance further increases.

(4) The UV transmission characteristics of the underlayer are high, and the utilization efficiency of UV light in the photocatalytic film is high.

The metal oxide fine particles contained in the underlayer are at least one oxide selected from the group consisting of aluminum (Al), zirconium (Zr) and silicon (Si), and have an average particle diameter of 10 to 10. Since it is 60 nm and its molar ratio is in the range of 40 to 90%, the underlayer hardly absorbs ultraviolet light of 400 nm or less,
High UV transmission characteristics and high UV utilization efficiency of the photocatalyst film.

(5) The photocatalytic film has good film formability and coatability.

When the underlayer is porous, it easily contains water (H ₂ O) and the wettability is good, so that the adhesion of the photocatalytic film is improved.

The lamp according to claim 7 is a lamp body in which a glass bulb surrounds a light emitting portion and emits light containing light having a wavelength of 400 nm or less; and a glass bulb as a base and is attached to at least an outer surface thereof. And a photocatalyst according to any one of (1) to (6).

The principle of light emission of the lamp of the present invention does not matter.
For example, it is allowed to be an incandescent lamp, a discharge lamp, or the like.

In the case of an incandescent lamp, a halogen lamp having a higher color temperature has a higher light emission ratio at a wavelength of 400 nm or less than a general lighting lamp, but may be an incandescent lamp for general lighting.

In the case of a discharge lamp, either a low-pressure discharge lamp or a high-pressure discharge lamp may be used.

As a low-pressure discharge lamp, for example, there is a fluorescent lamp. Select the phosphor used for the fluorescent lamp and select 40
Emission below 0 nm can be increased appropriately. Such a fluorescent lamp is suitable as a lamp for activating a photocatalyst because the decrease in visible light is relatively small and the activation of the photocatalyst is better than that of a fluorescent lamp for general illumination. However, the present invention allows a fluorescent lamp using a phosphor of three-wavelength emission or a calcium halophosphate phosphor, which has been widely used for general illumination.

In addition, a germicidal lamp, a black light, a chemical lamp, and the like, which mainly use light emission of 400 nm or less, are allowed.

On the other hand, as a high-pressure discharge lamp, for example, a mercury lamp, a metal halide lamp, a high-pressure sodium lamp, and the like are allowed.

The glass bulb may be a mode surrounding the discharge medium, or may be an outer tube further surrounding the arc tube enclosing the light emitting section.

In the present invention, since the photocatalytic film is formed using the glass bulb of the lamp as a base, the photocatalytic film can be sufficiently activated even if the amount of light emitted from the lamp at 400 nm or less is small.

Further, when the lamp of the present invention is used, organic dirt substances such as tobacco oil and soot adhering to the glass bulb are decomposed by the photocatalysis, so that a decrease in luminous flux due to dirt on the glass bulb is reduced. Therefore, good illumination can be performed over a long period of time, and the lamp cleaning interval can be lengthened.

Further, heat convection is generated around the lamp due to the heat generated as the lamp is turned on, and the air in the room convects. Deodorization and sterilization of air in contact with the lamp are performed. Therefore, indoor air can be deodorized and sterilized by using the lamp of the present invention.

The luminaire of claim 8 is a luminaire main body provided with light control means; and the photocatalyst according to any one of claims 1 to 6, wherein at least a part of the luminous control means of the luminaire main body is formed as a base. And a body.

In the present invention, the lighting equipment may be either outdoor or indoor.

The light control means includes a reflector, a globe, a shade,
It is allowed to be used in one kind or a combination of arbitrary plural kinds such as a translucent cover and a louver.

Further, the photocatalytic film may be formed on the whole of the light control means, but may be formed on a part thereof.

When the light control means is used, the optical performance of the lighting fixture is reduced when dirt composed of organic substances such as smoke and tobacco fat adheres thereto, but the dirt is reduced by forming a photocatalytic film. Since it is decomposed, a decrease in optical performance can be suppressed.

In addition, by decomposing and sterilizing odorous substances in the air that have come into contact with the light control means, it is possible to perform deodorization and sterilization in the room.

Further, the lighting equipment can be made into a size and a structure that can be stored in, for example, a refrigerator, an air conditioner, an air purifier, and the like, and can be used as a deodorizing or sterilizing means by disposing the lighting equipment in these apparatuses.

As can be understood from the above description, since the photocatalytic film is formed on the light control means, it is preferable that the photocatalytic film has good transparency.

[0080]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a conceptual enlarged cross-sectional view of a principal part showing a cross section of a photocatalyst film in a first embodiment of the photocatalyst of the present invention.

In each figure, 1 is a substrate, 2 is an underlayer, 3
Is a photocatalyst film.

The base 1 is made of soda lime glass.

The underlayer 2 is composed of a mixture of aluminum oxide fine particles at a molar ratio of 80:20, is transparent and porous, and has an average surface depth of about 30 n.
m is a coating film formed on the uneven surface 2a.

The underlayer 2 is prepared by applying a coating solution in which aluminum oxide fine particles 2b having an average particle size of about 15 nm are dispersed in a solution of polysiloxane dissolved in ethanol, applied to the surface of the substrate 1, and dried. And formed by firing at about 150 ° C.

The photocatalytic film 2 is formed by binding ultrafine particles of titanium oxide having an average particle size of about 7 nm on the underlayer 2. The photocatalyst film 3 enters the uneven surface 2 a formed on the surface of the underlayer 2, and a very small amount of ultrafine particles are deposited on the underlayer 2.
And adheres to the underlayer 2. Although not shown here, when the cross section of the photocatalyst body of the present embodiment was observed with a micrograph, it was confirmed that the ultrafine particles of titanium oxide had permeated into the base layer 2 near the base 1.

FIG. 2 is a graph showing the spectral transmittance characteristics of the photocatalyst film in the first embodiment of the photocatalyst of the present invention.

In the figure, the horizontal axis represents the wavelength (nm), and the vertical axis represents the transmittance (%).

The curve shows the spectral transmittance characteristic of the photocatalyst film according to the present embodiment.

As is apparent from the figure, according to the present embodiment, the transmittance is improved in the visible light and ultraviolet regions.

FIG. 3 is a graph showing the measurement results of the ink decomposability in the first embodiment of the photocatalyst of the present invention.

In the figure, the horizontal axis indicates elapsed time (minutes), and the vertical axis indicates relative values of degradability.

The curve shows the decomposability of the ink according to the present embodiment.

As is clear from the figure, according to this embodiment, it is understood that the photocatalytic action is excellent.

FIG. 4 is a sectional front view of a main part showing a fluorescent lamp in one embodiment of the lamp of the present invention. In the figure, 11 is a glass bulb, 12 is a photocatalytic film, 13 is a phosphor layer, 14 is a filament electrode, and 15 is a base.

The glass bulb 11 functions as a base for the photocatalytic film 12, and hermetically accommodates therein a functional part as a fluorescent lamp. That is, a rare gas mainly composed of mercury and argon as a discharge medium is sealed in the glass bulb 11 for several torr, a phosphor layer 13 is carried on the inner surface, and a pair of filament electrodes 1 are provided at both ends.
4 is sealed.

The base 15 comprises an aluminum cap-shaped base body 15a made of aluminum and a pair of base pins 15b insulated from the base body 15a and is adhered to both ends of the glass bulb 11. Both ends of the filament electrode 14 are connected to base pins 15b, respectively.

When the fluorescent lamp of the present embodiment is used for illumination, the organic catalytic substances adhered to the surface of the fluorescent lamp are decomposed by the photocatalytic action of the photocatalyst film 12, and the odorous substances in the air contacted therewith are removed. It is decomposed and the surrounding odor is eliminated.

FIG. 5 is a perspective view showing a tunnel lighting device in one embodiment of the lighting device of the present invention.

In the figure, 21 is a lighting fixture main body, 22 is a front frame, 23 is a translucent glass cover, 24 is a lamp socket, 25 is a high-pressure discharge lamp, and 26 is a reflector.

The lighting fixture body 21 is formed by molding a stainless steel plate into a box shape having an opening on the front surface, and a mounting bracket 21a on the back surface.

The front frame 22 is formed by molding a stainless steel plate, and has a light projecting opening 22a in the center, a hinge 22b on one side, and a latch (not shown) on the other side. The hinge 2a is pivotally attached to one side of the front side of the lighting fixture body 21 so as to be openable and closable, and is fixed to a closed position by a latch.

The translucent glass cover 23 is mounted on the front frame 22 in a waterproof manner via the silicone rubber packing 2a. The translucent glass cover 23 transmits visible light and has relatively high transmittance characteristics in at least a part of an ultraviolet region having a wavelength of 400 nm or less.
A photocatalytic film shown in FIG. 1 is formed on the front surface of the translucent glass cover 23.

[0104] The lamp socket 24 is
It is arranged in.

The high-pressure discharge lamp 25 is 340 to 400 n
In the wavelength range of m, ultraviolet rays having an intensity of 0.05 W or more per 1000 lm of a visible light beam are emitted.

The reflecting plate 26 is provided in the lighting fixture main body 21 so that the light emitted from the high-pressure discharge lamp 25 is reflected by the reflecting plate 26 and exhibits a required light distribution characteristic. Are located.

A ballast, a terminal block and the like are arranged on the back side of the reflection plate 26 of the lighting fixture body 21.

[0108] Thus, the lighting fixture of the present embodiment is installed in the tunnel via the mounting bracket 21a and used for use, and illuminates the inside of the tunnel.

Further, ultraviolet rays mainly within the wavelength range of 340 to 400 nm emitted from the high-pressure discharge lamp 25 simultaneously with the illumination pass through the translucent glass cover 23 together with the visible light and enter the photocatalytic film. The film is activated by ultraviolet rays, and decomposes organic dirt such as soot and smoke to perform self-cleaning.

[0110]

According to the photocatalyst of claims 1 to 6,
It is possible to improve the film forming property and wettability of the photocatalyst film, increase the film strength, and enhance the photocatalytic effect by increasing the ultraviolet light utilization efficiency of the photocatalytic film because the underlayer absorbs less ultraviolet light. can do.

According to the lamp of the seventh aspect, a lamp having the effects of the first to sixth aspects can be provided.

According to the lighting device of the eighth aspect, it is possible to provide a lighting device having the effects of the first to sixth aspects.

[Brief description of the drawings]

FIG. 1 is a conceptual enlarged cross-sectional view showing a principal part of a photocatalyst film according to a first embodiment of the photocatalyst body of the present invention.

FIG. 2 is a graph showing a spectral transmittance characteristic of a photocatalyst film in the first embodiment of the photocatalyst of the present invention.

FIG. 3 is a graph showing the measurement results of the decomposability of ink in the first embodiment of the photocatalyst of the present invention.

FIG. 4 is a cross-sectional front view of a main part showing a fluorescent lamp in one embodiment of the lamp of the present invention.

FIG. 5 is a perspective view showing a lighting device for a tunnel in one embodiment of the lighting device of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Base, 2 ... Underlayer, 2a ... Uneven surface, 2b ... Oxide fine particles, 3 ... Photocatalytic film.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4G069 AA01 AA12 BA01A BA01B BA02A BA02B BA04A BA04B BA05A BA05B BA48A CA17 DA05 EA08 EB18X EB18Y EB19 EC22X EC22Y FA03 5C043 AA20 BB09 CC01 CC09 CD11 EC27 DD39 EB14

Claims (8)

[Claims] 1. A substrate comprising: at least one oxide fine particle selected from the group consisting of aluminum, zirconium and silicon and a silicon compound as a main component, wherein the oxide fine particles have an average particle diameter of 10 to 60 nm; An underlayer formed on the substrate so as to have a molar ratio of 40 to 90%; and a photocatalyst formed on the surface of the underlayer mainly by ultrafine titanium oxide particles having an average particle size smaller than the oxide fine particles. A photocatalyst, comprising: a film; 2. The photocatalyst according to claim 1, wherein the ultrafine titanium oxide particles of the photocatalyst film have an average particle size of 4 to 10 nm. 3. The photocatalyst according to claim 1, wherein the composite layer comprising the underlayer and the photocatalyst film has an average linear transmittance of visible light of 90% or more. 4. The photocatalyst according to claim 1, wherein the ultrafine titanium oxide particles of the photocatalyst film are mainly composed of anatase crystals. 5. The photocatalyst according to claim 1, wherein the ultrafine particles of titanium oxide in the photocatalyst film are a mixture of anatase crystal and rutile crystal. 6. The photocatalyst according to claim 1, wherein ultrafine particles of titanium oxide in the photocatalyst film are soaked in the underlayer. 7. A lamp body which surrounds a light emitting portion by a glass bulb and emits light containing light having a wavelength of 400 nm or less; and a glass bulb as a base and which is attached to at least an outer surface thereof. And a photocatalyst according to claim 1. 8. A lighting fixture main body provided with light control means; and a photocatalyst according to any one of claims 1 to 6, wherein at least a part of the light control means of the lighting fixture main body is formed as a base. A lighting fixture characterized by the fact that: