Luminaire and method for maintaining illuminance

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to a luminaire having excellent cleanability and self-purification and a method for maintaining the illuminance thereof.

【0002】

[Conventional technology]

Titanium oxide (TiO) on the surface of lighting equipment such as fluorescent lamps₂) Proposals to form a film and enhance self-purification are the proceedings of the Society (2nd Symposium "Recent Developments of Photocatalysts", December 25, 1995: The University of Tokyo), JP-A-6-25857. , JP-A-7-51646 and JP-A-7-11104.

【0003】

In the above-mentioned conference proceedings, by applying a liquid agent in which titanium oxide fine particles are dispersed and a liquid agent for sol-gel to the outer surface of a fluorescent lamp, stains such as ink and oil adhering to the lamp surface are decomposed, and at the same time, malodorous components are also decomposed. It has been reported that it will be done. According to JP-A-6-25857, a fluorescent lamp with little decrease in brightness can be obtained by spraying gaseous titanium isopropoxide onto the surface of phosphor particles to form a titanium oxide film on the surface. Is described. Japanese Unexamined Patent Publication No. 7-51646 discloses that a titanium oxide film is formed on the surface of glass or the like, and the titanium oxide film is irradiated with ultraviolet rays to decompose stains such as tar and oil and fat components. .. Japanese Unexamined Patent Publication No. 7-11104 discloses that by forming a titanium oxide film on the inner surface of a lighting cover, malodorous components and toxic components are decomposed and harmful ultraviolet rays are not emitted from fluorescent lamps. Has been done.

【0004】

[Problems to be Solved by the Invention]

In any of the above-mentioned prior examples, a titanium oxide film is formed directly on the arc tube or cover of a lighting fixture, and the titanium oxide film is irradiated with ultraviolet rays to chemically perform stain components and the like by photocatalytic action or photosemiconductor action. It cannot be used in an extremely harsh environment where the amount of dirt components is large and the photocatalytic decomposition action cannot catch up. Further, it does not effectively perform cleaning with rainwater, cleaning water, or the like when dirt is attached.

【0005】

[Means for solving problems]

In order to solve the above problems, the luminaire according to the present invention forms a surface layer containing optical semiconductor particles on the outer surface of the arc tube or the cover covering the arc tube, and the arc tube or light emitting light on which the surface layer is formed. The thickness of the cover covering the tube was set so that the illumination light from the light emitting source could excite the optical semiconductor particles to impart hydrophilicity to the surface layer.

【0006】

Here, as the surface layer, for example, a resin having a SiO bond (SiO).₂), Titanium oxide is dispersed and exists.

【0007】

Further, in addition to the above structure, a base layer for preventing the diffusion of alkali metal (Na, etc.) is formed on the surface of the arc tube or covers covering the arc tube, and the underlayer is composed of optical semiconductor particles. It may be a structure that forms a surface layer. As the base layer formed on the base material such as plastic, a resin having a SiO bond is preferable, and as the base layer formed on the base material such as glass, silicon dioxide is preferable.

【0008】

Originally, titanium oxide alone has some hydrophilicity, but by forming the base layer, impurities contained in the arc tube or the covers covering the arc tube diffuse to titanium oxide and inhibit the hydrophilicity of the surface layer. It has the effect of preventing it from happening.

【0009】

On the other hand, in the method for maintaining illuminance according to the present invention, a lighting fixture having a surface layer containing optical semiconductor particles formed on the outer surface of an arc tube or a cover covering the arc tube is turned on to excite the optical semiconductor particles. Illumination light having a wavelength equal to or lower than the wavelength is transmitted through the arc tube or the cover covering the arc tube to irradiate the surface layer, and the surface layer is made hydrophilic by exciting the optical semiconductor particles so as to exhibit this hydrophilicity. By sprinkling rainwater or washing water on the surface layer, foreign matter adhering to the surface layer was removed.

【0010】

Further, another method for maintaining illuminance according to the present invention is to light a luminaire in which a surface layer containing optical semiconductor particles is formed on an arc tube or an outer surface of a cover covering the arc tube, and the optical semiconductor particles. The surface layer is irradiated with illumination light having a wavelength equal to or lower than the excitation wavelength of No. 1 through the arc tube or the cover covering the arc tube, and the photo-semiconductor particles are excited to make the surface layer hydrophilic and adhere to the surface layer. A thin water film was formed without making water such as washing water, dew, or rainwater into water droplets, and the water in this thin water film state was dried.

【0011】

In the present invention, stains are removed by a physical action in addition to a chemical action. That is, in the chemical action, by irradiating optical semiconductor particles such as titanium oxide with light (ultraviolet rays) having an energy equal to or higher than the band gap, electrons are generated in the conduction band and holes are generated in the valence band by photoexcitation. , Decomposes dirt components, etc. by the reducing power of electrons and the oxidizing power of holes. In addition to this, in the physical action, by irradiating the photosemiconductor particles with light having an energy equal to or higher than the band gap, the polarity of the surface layer surface is increased and the amount of physically adsorbed water is increased, so that the hydrophilicity is improved. As a result, the dirt is peeled off from the surface of the luminaire as it is together with rainwater and washing water without being decomposed. By this action, even when a significant amount of dirt adheres and cannot be decomposed by a chemical decomposition action, the dirt can be easily removed and the lighting function can be maintained.

【0012】

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described below. (Example 1) Ammonia sinter type anatase type titanium sol (STS-11 manufactured by Ishihara Sangyo, solute concentration 35% by weight, average crystal particle size 17 nm) and colloidal silica sol (Nissan Chemical Snowtex O, solute concentration 20% by weight) , Average crystal particle size 15 nm, pH 3) was mixed so that the molar ratio of solid content was 88:12, and then applied to the surface of fluorescent lamp 1 (Toshiba FL20SW) shown in Fig. 1 (a) by the dipping method. , Bake at 450 ° C for 30 minutes, and TiO on the surface of fluorescent lamp 1 as shown in Fig. (B).₂And SiO₂The surface layer 2 composed of and was formed to have a thickness of 3 μm. The thickness of the tube of the fluorescent lamp 1 is 2 mm, which is a thickness that does not prevent the ultraviolet rays emitted from the white fluorescent lamp from reaching the surface layer 2. The contact angle of the surface layer of the surface layer of the fluorescent lamp obtained as described above immediately after firing was 15 °. In addition, the fluorescent lamp was turned on after being left in a dark place for one week, and as a result of measuring the elapsed time after turning on and the change in the contact angle, the contact angle with water changed even if it was left in the dark place for one week. It remained at 15 ° without lighting, and when lighting was started, the contact angle became 0 ° (superhydrophilic) in about 1 hour, and the contact angle was always 0 ° during lighting. Moreover, even if the lighting was stopped, the contact angle was less than 5 ° for about one week. When this fluorescent lamp was used on the street, it was self-cleaned by rainfall, and no decrease in illuminance occurred even after one month.

【0013】

FIG. 2A is a conceptual diagram of the surface layer before being irradiated with ultraviolet rays. As shown in this figure, since the alkyl group (R) is bonded to the Si atom, the surface layer before being irradiated with ultraviolet rays. Shows hydrophobicity. Then, when the surface layer is irradiated with ultraviolet rays, as shown in FIG. 2 (b), TiO₂The alkyl group (R) is replaced with a hydroxyl group (OH) by the photosemiconductor effect or photocatalytic effect of the above, and physically adsorbed water is bonded to this hydroxyl group (OH) by a hydrogen bond to form a thin water film on the surface of the surface layer, which is hydrophilic. The sex is demonstrated.

【0014】

(Example 2) The surface of the incandescent lamp 3 (Mitsubishi LW100V19W) shown in Fig. 3 (a) was coated with silicon alkoxide. The coating procedure is to first mix tetraethoxysilane, 36% hydrochloric acid, pure water, and ethanol at a ratio of 6: 2: 6: 86 (weight ratio), leave it for 1 hour, and after the heat generated by the mixing has subsided, dip it. Was applied to the surface of the incandescent lamp 3. Next, titanium alkoxide was coated on it. The coating procedure is prepared by first mixing tetraethoxysilane and ethanol at a ratio of 1: 9 (weight ratio), and then adding 10% by weight of 36% hydrochloric acid to tetraethoxysilane to suppress the hydrolysis rate. did. The solution was then dipped onto the silicon alkoxide layer in dry air. The coating amount is 45 μg / cm in terms of titanium oxide.²And said. Next, the silicon alkoxide layer and the titanium alkoxide layer are promoted by hydrolysis and dehydration condensation by drying for 1 to 10 minutes to form a silica layer and an amorphous titanium oxide layer, and then calcined at 450 ° C. SiO on the surface of the incandescent lamp 3 as shown in 3 (b)₂Layer 4 and TiO₂A surface layer 2 composed of layers 5 was formed.

【0015】

When the incandescent lamp produced as described above was left unlit in the toilet for one week, the contact angle with water was 30 °. When this was turned on, the contact angle became 0 ° in 6 hours.

【0016】

(Example 3) Mix the silica content weight in the silica sol (Grasca A manufactured by Japan Synthetic Rubber Co., Ltd.) so that the net weight of trimethoxymethylsilane (Grasca B manufactured by Japan Synthetic Rubber Co., Ltd.) is 3: 1. A liquid material having a total solute concentration of 20% by weight was applied to the polycarbonate lighting cover 6 (thickness 2 mm) shown in FIG. 4 (a). Then, it was heat-solidified at 100 ° C. to form a resin layer 7 having a film thickness of 5 μm. Next, the silica sol was added to anatase-type titanium oxide sol (TA-15 solute concentration 10% by weight manufactured by Nissan Chemical Industries, Ltd.), diluted with ethanol, and then the solution to which the trimethoxymethylsilane was added was placed on the resin layer 7. Applied. Then, it was heat-solidified at 150 ° C. to form a surface layer 2 having a film thickness of 0.5 μm. Here, the ratio of the titanium oxide solid content weight to the sum of the solid content weight (resin weight) of silica and trimethoxymethylsilane and the titanium oxide solid content weight was set to 50%.

【0017】

The contact angle of the surface layer prepared as described above was initially 90 °, but the contact angle one week after lighting became 0 °. When the lighting fixture with this lighting cover was used in the kitchen, even if the scattered oil stains adhered to the cover, it could be easily removed by washing with water.

【0018】

In the examples, an example in which a surface layer is formed on the arc tube itself of the lighting equipment or the outer surface of the cover is shown, but even if the surface layer is formed on the surface of the covers such as the lighting louver and the reflector. Good.

【0019】

[Effect of the invention]

As described above, the lighting fixture according to the present invention forms a surface layer made of a resin or the like having a Si-O bond containing optical semiconductor particles such as titanium oxide on the outer surface of the arc tube or the cover covering the arc tube. Alternatively, a layer of optical semiconductor particles is formed via an underlayer that prevents the diffusion of alkali metals contained in the arc tube or covers that cover the arc tube, and further covers the arc tube or arc tube on which this surface layer is formed. Since the thickness of the cover is set so that the illumination light from the light emitting source can excite the optical semiconductor particles to impart hydrophilicity to the surface layer, the illumination light that reliably excites the optical semiconductor particles reaches the optical semiconductor particles. Can be blamed.

【0020】

Then, when the illumination light that excites the optical semiconductor particles reaches the surface layer containing the optical semiconductor particles, the surface layer becomes hydrophilic, and rainwater or washing water is applied to the surface layer that exhibits this hydrophilicity. As a result, foreign matter adhering to the surface layer can be physically removed, and the cleaning effect is greatly improved.

【0021】

In addition, by making the surface layer hydrophilic, the water film such as washing water, dew, or rainwater adhering to the surface layer becomes a thin water film, so that it can be dried in a short time, and it functions as a lighting fixture. Is improved.

[Simple explanation of drawings]

[Figure 1]

(a) is an overall view of the lighting fixture according to the first embodiment, and (b) is an enlarged sectional view thereof. [Figure 2]

(a) is a conceptual diagram of a hydrophobic surface, and (b) is a conceptual diagram of a hydrophilic surface. [Fig. 3]

(a) is an overall view of the lighting fixture according to the second embodiment, and (b) is an enlarged sectional view thereof. [Fig. 4]

(a) is an overall view of the lighting fixture according to Example 3, and (b) is an enlarged sectional view thereof. [Explanation of symbols]

1 ... fluorescent lamp, 2 ... surface layer, 3 ... incandescent lamp, 4 ... SiO₂Layer, 5 ... TiO₂Layer, 6 ... cover, 7 ... resin layer.