JPH11262671A - Optical catalyst body and lighting fixture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical catalyst body and a lighting fixture to prevent soiling by utilizing a relation between a temperature of a base for coating an optical catalyst film and an adhered quantity of substance causing soiling. SOLUTION: The optical catalyst body 1 is provided with a base 2, an optical catalyst film 4 formed on at least one portion of the region on the base 2, and a heating means 3 for heating the base 2 to a specified temperature. Thus, when the temperature of a translucent cover is raised, a flow (an air stream) of contamination substance changes in the vicinity of the surface, namely an air stream ascending against the translucent cover increases, than adherence of the soiling becomes difficult.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a photocatalyst using a photocatalyst and a lighting apparatus.

[0002]

2. Description of the Related Art Conventionally, in road or tunnel lighting fixtures, carbon particles contained in exhaust gas and incompletely combusted oil mist emitted from diesel engine vehicles have been increased with the increase in the number of automobiles in recent years. Such,
Substances causing fouling are increasing. As a result, exhaust gas from automobiles adheres to the translucent cover on the front of the appliance,
In a short period of time, the light output will drop and the brightness in the tunnel will decrease. Frequent cleaning work will be required to maintain proper illuminance. I have. In particular, these road or tunnel lighting fixtures are installed at high places on roads where vehicles are constantly driving and in dark places in tunnels, so maintenance work is dangerous and reduces risk. For this reason, when driving restrictions are imposed, traffic congestion becomes a major problem in road operation.

In order to solve such a problem, for example, Japanese Unexamined Patent Application Publication No. 9-237511 discloses a technique for efficiently disassembling dirt on road or tunnel lighting equipment and reducing maintenance costs. It has been disclosed.

This prior art is based on the photocatalysis of a metal oxide semiconductor such as titanium oxide. A photocatalytic film is applied to the outer surface of a light-transmitting cover of a lighting fixture, and is exposed to sunlight or a high-pressure discharge lamp or a fluorescent lamp. In addition, the photocatalytic action is activated by ultraviolet light contained in the radiation light of an artificial light source such as an incandescent light bulb to remove dirt.

On the other hand, Japanese Patent Application Laid-Open No. Hei 7-111104 discloses a technique for applying a photocatalytic film to a light-transmitting cover such as a shade to prevent contamination in general lighting equipment for facilities and homes.

[0006]

However, looking at the situation where the above-mentioned conventional lighting device for roads or tunnels is actually installed in a tunnel, it is found that the balance between the amount of dirt and the decomposing power of the photocatalytic film causes all conditions to be satisfied. In some cases, it is difficult to show an effective effect. For this reason, it has been found that when such a situation occurs, it is necessary to perform a cleaning operation every time.

In response to this problem, the present inventors have conducted detailed research and found that the effect of preventing contamination, that is, the antifouling effect is determined by the ratio (α) expressed by the following equation. .

[0008]

(Equation 1) For this reason, it has been found that it is important how to prevent the contaminants from being adsorbed on the photocatalyst film under the condition that the decomposition power of the photocatalyst is constant.

Therefore, as a result of conducting experiments under various conditions such as tunnels and roads, there is a correlation between the temperature of the light-transmitting cover, which is the front glass of the appliance, and the amount of adhered dirt, and the temperature of the light-transmitting cover is reduced. It was found that the amount of soiling substances decreased when the temperature was increased. The details of this phenomenon are unknown, but when the temperature of the translucent cover is increased, the flow (airflow) of the contaminant near the surface changes, that is, the airflow that rises with respect to the translucent cover increases. It is considered that dirt hardly adheres.

[0010] This phenomenon also occurs in the case where a photocatalytic film is applied to a light-transmitting cover of a general lighting fixture to prevent contamination, and when the temperature of the substrate on which the photocatalytic film is applied is increased, the contaminant substance is reduced. The relationship is that the amount of adherence decreases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a photocatalyst and a lighting device which prevent contamination by focusing on the relationship between the temperature of a substrate on which a photocatalytic film is applied and the amount of a substance which causes contamination. And

[0012]

The photocatalyst of claim 1 is:
It is characterized by comprising a base material, a photocatalytic film formed in at least a part of the region on the base material, and a heating means for heating the base material to a predetermined temperature.

In this claim and the following claims,
The definitions and technical meanings of the terms are as follows unless otherwise specified.

The substrate must prevent dirt from adhering to the substrate over a long period of use and impair the original function of the substrate. The material may be any of metal, synthetic resin, glass, ceramic, and the like. For example, in the field of lighting equipment, a transparent cover made of glass or synthetic resin,
A metal reflecting plate, a metal or synthetic resin device main body, and the like correspond to this.

When the base material is a light-transmitting cover of a lighting fixture, the material may be any substance having a property of selectively transmitting light of 410 nm or less and a substance having a property of transmitting visible light. Any of these can be selected and used. For example, various inorganic substances such as soda lime glass, borosilicate glass, and quartz glass, microcrystalline glass, translucent ceramics, and translucent single crystal in addition to soda lime glass, borosilicate glass, and quartz glass, which are often used for lighting, It can be arbitrarily selected and used from the group of a transparent organic material such as a transparent synthetic resin. Further, the shape, size and thickness of the substrate can be arbitrarily selected. The reason is that when irradiating light from the back of the substrate to activate the photocatalyst, the substrate is not particularly limited as long as the energy of light transmitted through the substrate is at a level necessary to activate the catalyst. It is.

The photocatalyst film of the present invention is fired at an optimum temperature to increase the visible light transmittance or the photocatalytic activity as required.

The method for producing the photocatalyst film and the method for forming the film on the substrate may be any. For example, a desired titanium oxide can be obtained by hydrolyzing a titanium alkoxide produced in the presence or absence of a noble metal. The titanium oxide film thus manufactured has high transparency and can be a thin and dense film. A known method such as a spray method, a dipping method, or a CVD method can be used as a method of applying the application liquid to the substrate.

In the present invention, the expression that the photocatalyst film is formed in at least a part of the region of the substrate means that it is not necessary to dispose the photocatalyst film on the entire surface of the substrate, but it may be formed on a required part. Is the meaning of For example, since the light-transmitting cover, which is the base material, is attached to the apparatus body in a liquid-tight manner, if the packing comes into contact with the light-transmitting cover, the photocatalytic film can be prevented from being formed around the light-transmitting cover. . Further, the photocatalyst film may be provided only on the inner surface of the substrate, only on the outer surface, or on both inner and outer surfaces.

The heating means of the present invention is a means for heating with infrared light emitted from the light emitting means and heat absorbed by the infrared absorbing means. A device that heats with infrared light emitted from the light emitting means and infrared light reflected back by the reflecting means. In addition, it includes a device that is heated by the heat of a heat generating means such as an infrared ray emitted from the light emitting means and a heater that generates heat itself.

In the present invention, heating the base material to a predetermined temperature means that when the photocatalyst of the present invention is applied to a lighting fixture, it is heated at least in its use state, that is, in the lighting state of a lamp which is a light emitting means. However, if the heating means itself generates heat, that is, a heater that heats to a predetermined temperature, it only means that power is always supplied to the heater. Rather, it also includes a heater for turning on and off a heater, which is a heat source, at predetermined time intervals for temperature control or power saving. , A transparent cover that is a base material,
It is sufficient that the state where the reflector, the instrument body, and the like are heated to a predetermined temperature by the heater is maintained.

Thus, the photocatalyst obtained by the present invention can reduce the amount of contaminants adhered by raising the temperature of the base material by heating means, and can prevent the antifouling action of the photocatalyst for a long time. Can be demonstrated. Particularly when the photocatalyst of the present invention is applied to a light-transmitting cover of a lighting fixture,
Combined with the effect of reducing the amount of adhered contaminants, organic contaminants (for example, oil film,
Due to the action of decomposing and removing tobacco fat, etc., proper illuminance, which is the original function of the translucent cover, can be maintained for a long period of time. Further, when applied to lighting equipment for facilities or homes, it is expected to have an effect of decomposing substances causing odor such as acetaldehyde and various germs, as well as an antifouling effect.

[0022] The photocatalyst according to claim 2 comprises a light-transmitting base material,
A photocatalyst film formed in at least a part of the region on the substrate, a light emitting unit disposed to face the substrate and emitting light including infrared rays, and an absorption unit provided on the substrate and absorbing infrared rays from the light emitting unit And a heating means comprising:

The translucency of the present invention permits the transmission of ultraviolet light, visible light and infrared light, and may be any one or both of sunlight and artificial light, and the wavelength range is arbitrary.

The light-emitting means of the present invention may be any light-emitting source that emits light up to the ultraviolet, visible and infrared regions as the light region. When applied to a lighting device for a tunnel, it means a lamp itself such as a high-pressure sodium lamp.

The absorbing means of the present invention for absorbing infrared rays includes:
It is sufficient that the infrared ray generated from the light emitting means is accumulated in the base material by the absorbing means, and the base material is heated together with the infrared light generated by the light emitting means. When the photocatalyst of the present invention is applied to a lighting device, the light emitting means The lamp is a heat source, an infrared absorbing film is formed on the inner or outer surface of the light-transmitting cover that is the base material, and a photocatalytic film is formed on the outer surface, and infrared light generated by the lamp is transmitted by the absorbing film. This can be realized by heating the transparent cover, which is a base material, together with the infrared rays generated from the lamp itself and accumulated in the transparent cover. Further, an infrared absorbing film may be formed on both the inner and outer surfaces of the light-transmitting cover to increase the efficiency of absorbing infrared rays, and the light-transmitting cover may be heated more efficiently.

The infrared absorbing film may have a function of transmitting ultraviolet light and visible light and absorbing infrared light. For example, a transparent conductive film mainly composed of tin oxide may be used. Good. The method of forming the infrared absorbing film includes spraying, dipping, CVD, P
A VD method or the like can be used.

[0027] The photocatalyst according to claim 3 comprises a light-transmitting base material,
A photocatalyst film formed in at least a part of the region on the base material, a light emitting unit provided to face the base material and emitting infrared light, and a reflection provided on the base material and reflecting infrared light from the light emitting unit And a heating means comprising:

The reflecting means for reflecting infrared rays according to the present invention includes:
The infrared ray generated from the light emitting means may be returned to the base material by the reflection action, and the base material may be heated together with the infrared light generated by the light emitting means. For example, the photocatalyst of the present invention is applied to a lighting fixture. In this case, an infrared reflective film is formed on the outer surface of the light-transmitting cover serving as the base material, and a photocatalytic film is further formed thereon, and the infrared light generated by the lamp as the light emitting means is returned to the light-transmitting cover by the reflecting film. This can be realized by heating the translucent cover which is the base material together with the infrared rays generated from the lamp itself.

The infrared reflecting film may have a function of transmitting visible light and reflecting infrared light. For example, the infrared reflecting film is formed on the outer surface of a bulb of a halogen bulb and has been put to practical use.
A metal oxide dielectric multilayer film in which seven to nine high refractive index layers and low refractive index layers are alternately stacked is preferred. The high refractive index layer is made of a material containing titanium oxide as a main component, and the low refractive index layer is made of a material containing silicon oxide as a main component and containing aluminum oxide.

[0030] The photocatalyst according to claim 4 comprises a light-transmitting base material,
A photocatalyst film formed in at least a part of the region on the substrate, a light-emitting device that emits infrared light toward the substrate, and an infrared-absorbing film that is provided on the substrate and absorbs infrared light from the light-emitting device and faces the light-emitting device. And a heating means comprising a reflecting plate provided as described above.

The present invention can be realized by the following configuration. That is, a light-transmitting cover on which a photocatalytic film and an infrared absorbing film are formed, a lamp in the center of the device main body, and a reflector opposed to the back of the lamp are arranged on the front surface of the appliance body. This can be realized by returning infrared rays radiated to the back side from the lamp to the front light-transmitting cover, and heating the light-transmitting cover together with the action of the infrared absorbing film provided on the light-transmitting cover as the base material.

The reflecting plate of the present invention may be a metal plate made of stainless steel or the like and subjected to chrome plating to form a reflecting surface, or a glass reflecting plate formed by depositing silver or aluminum or the like to form a reflecting surface. . In the case of a reflecting plate made of glass, the above-mentioned infrared reflecting film may be formed on the back surface.

[0033] The photocatalyst of claim 5 comprises: a light-transmitting base material;
A photocatalyst, comprising: a photocatalyst film formed in at least a part of a region on a substrate; and a heating unit including a heating unit provided on the substrate.

The heating means of the present invention may be any heating means such as an electric heater for heating the substrate. For example, when the photocatalyst of the present invention is applied to lighting equipment, In order not to hinder the translucency of the glass on the inner surface or the outer surface of the translucent cover to be formed, the heater can be realized by meandering or parallelly arranging a heater made of a fine wire and generating electricity by energizing. In addition, heaters may be arranged on both sides to increase the amount of heat generated, and the translucent cover may be heated more efficiently. Further, a transparent or translucent printing heater may be used. The heater may not be provided directly on the light-transmitting cover, but may be heated by installing a separate heater close to the light-transmitting cover.

In this example, the heater is energized while the lamp, which is a light emitting means, is turned on. However, in the case of a device such as a street light or a road lighting device in which the lamp is turned off during the day, or in a tunnel. It is desirable that the heater is not turned off and that the heater is always energized regardless of whether the lamp is turned on or off when the lighting device is turned off after thinning. The reason is that when the heater that is generating heat when the lamp is turned on is turned off, the updraft that has made it difficult for dirt to adhere to the surface of the translucent cover temporarily flows backward,
This is considered to prevent the antifouling action from being reduced.

A lighting device according to a sixth aspect is characterized in that the photocatalyst according to any one of the second to fifth aspects forms a part of the lighting device.

The lighting fixture of the present invention allows outdoor lighting fixtures such as road or tunnel lighting fixtures, street lights, floodlights, etc., as well as general lighting fixtures used indoors for homes and facilities such as buildings.

[0038]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is an enlarged cross-sectional view schematically showing a main part of a first embodiment of the photocatalyst of the present invention, and FIG.
FIG. 2 is a partially cutaway perspective view showing a tunnel lighting device using the photocatalyst of FIG.

In FIG. 1, 1 is a photocatalyst, 2 is a substrate,
Reference numeral 3 denotes an infrared absorbing film formed on the outer surface of the substrate, and reference numeral 4 denotes a photocatalytic film formed on the upper surface of the infrared absorbing film. The base material 2 is a glass plate, and is a soda-lime glass that transmits light having a wavelength of at least 410 nm or less. Reference numeral 11 denotes a lamp as light emitting means.

The infrared absorbing film is composed of a transparent conductive film mainly composed of tin oxide, and has a thickness of about 0.08 μm.

The infrared absorbing film 3 is formed on the glass plate 2 by the following method.
Formed on the outer surface. First, the glass plate is placed in a heating furnace while being kept horizontal, and heated. The heating temperature at this time is about 560 ° C
It is. In this state, tin tetrachloride vapor is introduced from above toward the upper surface of the glass plate. At this time, the dimethyltin dichloride was decomposed by contact with the high temperature of the glass plate, and at the same time, was oxidized and deposited on the upper surface of the glass plate in the form of tin oxide to form an infrared absorbing film.

Next, a photocatalytic film 4 was formed on the infrared absorbing film 3 by the following method. That is, titania alkoxide was applied to the surface of the infrared absorbing film on which the infrared absorbing film was formed by dip coating, dried, and fired at about 650 ° C. for about 5 minutes to form a photocatalytic film. The thickness of the photocatalyst film is approximately 0.
The range was from 01 μm to 0.1 μm. According to the above method, the photocatalyst 1 composed of the glass plate 2 having the infrared absorbing film 3 and the photocatalytic film 4 formed on the outer surface thereof was formed.

Next, an embodiment in which the photocatalyst 1 constructed as described above is used for a lighting device for a tunnel will be described with reference to FIG.

The tunnel lighting fixture 5 has a stainless steel fixture body 6 of a hollow thin box rectangular parallelepiped.
A light projecting opening 7 is formed on the lower surface of the device main body 6, and a plate-like mounting leg 8 for mounting is formed on the back surface of the device main body 6. A mirror-finished curved stainless steel reflecting plate 9 that reflects light toward the opening 7 in opposition to the opening 7 is mounted in the instrument body 6. A lamp socket 10 is attached to one end of the reflector 9 in the longitudinal direction.
The lamp socket 10 has a thickness of 300 nm to 400 nm.
A high-pressure sodium lamp 11 with a rating of 110 W as a light source that emits ultraviolet light of nm is detachably mounted.

The opening 7 is formed in a frame 12 which forms a part of the instrument body 6, and the opening 7 of the frame 12 has a photocatalyst 1 made of the glass plate 2 constructed in the first embodiment.
Is mounted as the light-transmitting cover 13 of the appliance main body 6 with the surface on which the photocatalytic film is formed facing the outer surface of the appliance main body 6.

That is, the packing 15 is fitted into the opening 7, and the glass plate 2 is fitted into the groove formed on the inner peripheral edge of the packing 15, and the glass plate 2 is
Is kept watertight. The frame body 12 is attached to the instrument main body 6 by a hinge 14 provided on one side so as to be openable and closable, and the latch 12 (not shown) provided on the other side of the opening 7 closes the frame body 12 during use. It is held in the instrument body 6 in the state. Further, packing (not shown) for sealing the frame 12 in a watertight manner in a state where the frame 12 is closed to the instrument body 6 is provided on the instrument body 6.
Is installed.

A starting circuit for starting and lighting the high-pressure sodium lamp 11 and a ballast are housed at a desired position in the apparatus main body.

Activating the lighting fixture configured as described above,
That is, when the high-pressure sodium lamp 11 is turned on, light from the lamp 11 is incident from the back surface of the glass plate 2 of the photocatalyst 1, and the photocatalytic film 3 is activated by ultraviolet light having a wavelength of 410 nm or less when transmitted through the glass plate 2. The photocatalyst 1 exerts a desired soil decomposition power.

Further, the high-pressure sodium lamp 11 contains infrared rays. The infrared rays enter from the back surface of the glass plate 2, and the transmitted infrared rays are transmitted to the front surface of the glass plate 2 by the infrared absorbing film 3 formed on the front surface of the glass plate 2. With the accumulated infrared rays generated from the lamp itself, the front surface of the glass plate 2 is heated to increase the temperature. As a result, the airflow near the front surface of the glass plate changes, that is, the airflow that rises with respect to the front surface of the glass plate increases, and an effect of making it difficult for dirt to adhere is exhibited.

The lighting equipment for a tunnel according to the present embodiment was installed in a tunnel on a highway for three months together with a conventional lighting equipment without an infrared absorbing film, and a field test was conducted. Was observed.

While the conventional device without the infrared absorbing film has a 22% reduction in transmittance, the device of the present embodiment has only a 12.5% reduction in light transmittance.

When the temperature of the front surface of the glass plate was measured in the above-mentioned field test, the conventional device without the infrared absorbing film was 6
The temperature was 2 ° C., whereas the temperature of the device of the present embodiment was 86 ° C. In the high-pressure sodium lamp 11 having a rating of 110 W used in the test, 1/5 to 1/4 is infrared light, and this infrared light is reflected by the infrared absorbing film on the front surface of the glass plate.
By increasing the temperature, the rising airflow near the front surface of the glass plate increases, thereby exhibiting the effect of making it difficult for dirt to adhere.

Next, a second embodiment of the present invention will be described with reference to FIG.

FIG. 3 is a cross-sectional view schematically showing a main part of a second embodiment of the photocatalyst according to the present invention in an enlarged manner.

In FIG. 3, 16 is a photocatalyst, 17 is a substrate, 18 is an infrared reflection film formed on the outer surface of the substrate, 19
Is a photocatalytic film formed on the upper surface of the infrared reflective film. The base material 17 is a glass plate, and is a soda-lime glass that transmits light having a wavelength of at least 410 nm or less. Reference numeral 11 denotes a lamp as light emitting means.

The infrared reflecting film 18 was formed on the outer surface of the glass plate by the following dipping method. First, about 10 mm of the inner and outer peripheral portions of the glass plate are masked with an adhesive heat-resistant sheet, the glass plate masked with a solution of titanium alkoxide dissolved in an alcohol-based solvent is immersed, pulled up at a constant speed, dried, and then dried. The resultant was baked at about 500 ° C. for about 10 minutes to form a high refractive index layer made of titanium oxide. Next, the glass plate on which the high refractive index layer is formed is immersed in a solution in which an alkoxysilane is dissolved in an organic solvent together with an alkoxide of aluminum.
The resultant was baked at 0 ° C. for about 10 minutes to form a low refractive index layer. This step was repeated nine times to form an infrared reflective film, and finally the masking was peeled off. The thickness of the reflection film is 0.1 to 0.3 μm for each of the high and low refractive index layers, and nine layers are stacked.

Next, the photocatalyst film 1 is formed on the upper surface of the infrared reflection film 18.
9 was formed by the following method. That is, the titania alkoxide is applied to the film forming surface of the infrared reflection film by dip coating, dried, and dried at about 650 ° C. for about 5 hours.
It was baked for a minute to form a photocatalyst film. The thickness of the photocatalyst film was in the range of approximately 0.01 μm to 0.1 μm. According to the above method, the photocatalyst 16 composed of the glass plate 17 having the infrared reflection film 18 and the photocatalyst film 19 formed on the outer surface thereof was formed.

Next, an embodiment in which the photocatalyst 16 constructed as described above is used for a tunnel lighting device will be described with reference to FIG.

That is, in the lighting device for a tunnel shown in FIG.
Is mounted by setting the surface on which the infrared reflective film 18 and the photocatalyst film 19 are formed on the outer surface thereof to the outer surface side of the instrument body 6. Other configurations are the same as those of the first embodiment.

By turning on the high-pressure sodium lamp 11 of the lighting apparatus configured as described above, light from the lamp 11 is incident from the back surface of the glass plate 17 on which the photocatalytic film 19 is formed, and is transmitted when the light passes through the glass plate 17. The photocatalyst film 19 is activated by ultraviolet light having a wavelength of 410 nm or less, and exhibits a desired dirt decomposition power.

Further, the high-pressure sodium lamp 11 contains infrared rays. The infrared rays enter from the back surface of the glass plate 17, and the transmitted infrared rays are transmitted to the front surface of the glass plate 2 by the infrared reflection film 18 formed on the front surface of the glass plate 17. Reflected,
With the infrared rays generated from the lamp itself, the front surface of the glass plate 17 is heated to increase the temperature. As a result, the airflow near the front surface of the glass plate changes, that is, the airflow that rises with respect to the front surface of the glass plate increases, and an effect of making it difficult for dirt to adhere is exhibited.

The lighting equipment for a tunnel according to the present embodiment was installed in a tunnel on an expressway for three months along with a conventional equipment having no infrared reflecting film, and a field test was conducted. As a result, substantially the same effect as in the first embodiment was obtained.

Next, a third embodiment of the present invention will be described with reference to FIG.

FIG. 4 is a cross-sectional view schematically showing a third embodiment of the photocatalyst according to the present invention, in which main parts are enlarged.

In FIG. 4, 20 is a photocatalyst, 21 is a substrate, 22 is an infrared reflecting film formed on the outer surface of the substrate, 23
Is a glass plate, and 24 is a photocatalytic film formed on the outer surface of the glass plate 23. The substrate 21 is a glass reflection plate. The glass plate 23 is a soda-lime glass that transmits at least light having a wavelength of 410 nm or less. Reference numeral 11 denotes a lamp as light emitting means.

The infrared reflection film 22 on the base material, that is, the reflection plate 21 made of glass, is formed by silver (Ag) evaporation or aluminum (Al) evaporation. This infrared reflection film 2
No. 2 reflects visible light as well as infrared light.

Next, the photocatalyst film 24 formed on the outer surface of the glass plate 23 was formed by the following method as in the first embodiment. That is, the titania alkoxide was applied to the outer surface of the glass plate by dip coating, dried, and fired at about 650 ° C. for about 5 minutes to form a photocatalytic film. The thickness of the photocatalyst film 24 is approximately 0.01 μm to 0.1 μm
Within the range. As a result, a photocatalyst body 20 including the reflection plate 21 on which the infrared reflection film 22 was formed and the glass plate 23 on which the photocatalyst film 24 was formed was formed.

Next, an embodiment in which the photocatalyst body 20 constructed as described above is used for a tunnel lighting device will be described with reference to FIG.

That is, in the tunnel lighting fixture shown in FIG. 2, a high-pressure sodium lamp is provided with a reflecting plate 21 having the structure shown in FIG. And a light-transmitting cover 13 of the opening 7.
In place of the glass plate 23 shown in FIG.
The device was configured such that the surface on which the device 4 was formed was mounted on the outer surface of the device main body 6. Other configurations are the same as those of the first embodiment.

By turning on the high-pressure sodium lamp 11 of the lighting apparatus configured as described above, the light of the lamp 11 is incident from the back surface of the glass plate 23 on which the photocatalytic film is formed, and is 410 nm when transmitted through the glass plate 23. The photocatalytic film 24 is activated by ultraviolet rays having the following wavelengths, and exhibits a desired dirt-decomposing power.

The high-pressure sodium lamp 11 contains infrared rays. The infrared rays radiated from the front side of the lamp heat the glass plate 23 and the infrared rays radiated from the rear side of the lamp are formed on the back side of the reflection plate 21. The reflected infrared reflection film 22 efficiently reflects the infrared light toward the glass plate 23 efficiently without being radiated as heat to the rear surface of the reflection plate 21, and heats the glass plate to increase the temperature. Thereby, similarly to the first embodiment, the glass plate 2
(3) The ascending airflow near the front surface is increased to exert an effect of making it difficult for dirt to adhere.

The tunnel lighting fixture of the present embodiment was installed in a tunnel on an expressway for three months along with a conventional fixture without an infrared reflective film, and a field test was conducted. As a result, substantially the same effect as in the first embodiment was obtained.

The reflector 21 of the third embodiment may be a metal reflector such as aluminum (Al) as long as it reflects infrared light and visible light.

Next, a fourth embodiment of the present invention will be described with reference to FIG.

FIG. 5A is a cross-sectional view schematically showing an enlarged main part of a fourth embodiment of the photocatalyst of the present invention.
(B) is a perspective view thereof.

In FIG. 5, 25 is a photocatalyst, 26 is a base material, 27 is a heater wire as a heating means formed on the outer surface of the base material, and 28 is a photocatalyst film formed on the upper surface of the heater wire. Substrate 26 is a glass plate, at least 410 nm
The photocatalyst film 28 is a soda lime glass that transmits light of the following wavelengths, and is formed on the outer surface of the glass plate 26 covering the heater wires 27. Reference numeral 11 denotes a lamp as light emitting means.

The heater wire was attached to the glass plate 26 as a base material by forming a 0.3 mm-diameter nichrome wire in a meandering shape, and using the formed nichrome wire on the outer surface of the glass plate 26 using a heat-resistant adhesive. It was configured by sticking. The power of the heater wire was set to 100W.

Next, the photocatalyst film 28 formed on the outer surface of the glass plate 26 was formed by the following method as in the first embodiment. That is, first, the inner surface of the glass plate where the heater wire is not attached is masked with an adhesive heat-resistant sheet,
The titania alkoxide was applied to the outer surface of the glass plate by dip coating, dried, and baked at about 650 ° C. for about 5 minutes to form a photocatalytic film. The thickness d of the photocatalyst film 3 was in the range of approximately 0.01 μm to 0.1 μm. Finally, the masking on the inner surface was peeled off to form a photocatalyst body 25 composed of a glass plate 26 having a heater wire 27 and a photocatalyst film 28 formed on its outer surface.

Next, an embodiment in which the photocatalyst body 25 constructed as described above is used for a tunnel lighting device will be described with reference to FIG.

That is, in the lighting fixture for tunnel shown in FIG.
Is mounted by setting the surface on which the heater wire 27 and the photocatalyst film 28 are formed on the outer surface side of the apparatus main body 6. Other configurations are the same as those of the first embodiment.

By turning on the high-pressure sodium lamp 11 of the luminaire configured as described above, light from the lamp 11 is incident from the back surface of the glass plate 26 on which the photocatalytic film 28 is formed, and is transmitted through the glass plate 26. The photocatalyst film 28 is activated by ultraviolet light having a wavelength of 410 nm or less, and exhibits a desired dirt decomposition power.

Further, by energizing the heater 27, the glass plate 26 is heated, thereby increasing the ascending airflow near the front surface of the glass plate 26 and exerting an effect of making it difficult for dirt to adhere as in the first embodiment. .

The tunnel lighting fixture of this embodiment was installed in a tunnel on a highway for three months along with a conventional fixture without a heater wire, and a field test was conducted. As a result, substantially the same effects as in the first embodiment were obtained.

When the photocatalyst 25 of the fourth embodiment was used not for a tunnel but for a road lighting device, and a three-month field test was conducted on an expressway in the same manner as described above. Has fallen. This is because, in the case of road lighting equipment, the heater is turned off when the light is turned off in the daytime, the heating state on the photocatalyst is reduced, and the rising air current that made it difficult for dirt substances to adhere near the surface of the light-transmitting cover is reduced. This is considered to be due to the temporary backflow and the reduction in the antifouling effect. By turning on the heater even when the heater was turned off, the same effect level as in the above embodiments could be achieved.

[0086]

According to the present invention, the substrate is irradiated with light to activate the photocatalyst film, and has an antifouling effect of decomposing and removing organic and other dirt adhered to the substrate, and has a long-term effect. The original function of the substrate can be maintained. Further, it is possible to provide a photocatalyst and a lighting device that also have an effect of decomposing substances causing malodor such as acetaldehyde and various germs.

[Brief description of the drawings]

FIG. 1 is an enlarged cross-sectional view schematically showing a main part of a photocatalyst according to a first embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view showing a tunnel lighting device using the photocatalyst of FIG. 1;

FIG. 3 is a cross-sectional view schematically showing an enlarged main part of a photocatalyst according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view schematically showing a main part of a photocatalyst body according to a third embodiment of the present invention in an enlarged manner.

FIG. 5A is a cross-sectional view schematically showing an enlarged main part of a photocatalyst according to a fourth embodiment of the present invention, and FIG. 5B is a perspective view thereof.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Photocatalyst, 2 ... Substrate, 3 ... Infrared absorption film, 4 ... Photocatalyst film.

Claims (6)

[Claims] 1. A substrate comprising: a substrate; a photocatalytic film formed in at least a part of the region on the substrate; and a heating unit for heating the substrate to a predetermined temperature. Photocatalyst. 2. A light-transmitting substrate; a photocatalytic film formed on at least a part of the region on the substrate; A heating means provided on the material and comprising an absorbing means for absorbing infrared rays from the light emitting means. 3. A light-transmitting substrate; a photocatalytic film formed on at least a part of the region on the substrate; and a light-emitting means and a substrate for emitting light including infrared rays disposed opposite to the substrate. A heating means provided on the member and reflecting means for reflecting infrared rays from the light emitting means; 4. A light-transmitting substrate; a photocatalytic film formed on at least a part of a region of the substrate; a light-emitting means for emitting infrared rays toward the substrate; A heating means comprising: an infrared absorbing film for absorbing infrared light; and a reflector provided opposite to the light emitting means. 5. A light-transmitting base material; a photocatalytic film formed on at least a part of the base material; and a heating means provided on the base material and comprising a heat generating means. A photocatalyst, characterized in that: 6. A lighting device, characterized in that the photocatalyst according to any one of claims 2 to 5 constitutes a part of the lighting device.