JPH1196971A - Light source with photocatalyst and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance a production speed and facilitate manufacturing, by making a condition in which interference color is seldom produced. SOLUTION: Photocatalyst chemical composed of titanium sol made by diluting alkoxide of titanium with alcohol and hydrolyzing it with acid catalyst is supplied to a spray nozzle 2 through a hose 3, and as a straight tube type arc tube 1 of glass is being rotated, the photocatalyst chemical is coated on the arc tube 1 by spraying the photocatalyst liquid-drops with diameter of 5-30 μm, it is baked at 500 deg.C after drying, and photocatalyst film in a condition that flaky particles with diameter of 10-100 μm are piled, is formed on the outer surface of the arc tube 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source with a photocatalyst, such as a fluorescent lamp with a photocatalyst, having a photocatalyst film formed on the outer surface of an arc tube, and a method for manufacturing the same.

[0002]

2. Description of the Related Art Recently, a light source with a photocatalyst in which a photocatalyst film is formed on the outer surface of an arc tube has been considered. In the light source with a photocatalyst, since the photocatalyst film decomposes organic matter, it is necessary to prevent the outer surface of the arc tube from becoming dirty. As a result, the brightness of the light source with a photocatalyst can be prevented from lowering, and there are also deodorizing, antibacterial and sterilizing effects.

Conventionally, in order to form a photocatalytic film on the outer surface of an arc tube made of glass of a fluorescent lamp with a photocatalyst, the arc tube is immersed in a dip tank containing a photocatalyst chemical solution, thereby forming an outer surface of the arc tube. After applying the photocatalytic chemical, it is baked.

[0004]

However, in such a fluorescent lamp with a photocatalyst, when a titanium oxide (TiO ₂ ) film having a high refractive index is used as the photocatalyst film, the surface of the photocatalyst film becomes flat. Since the interference color of the rainbow color in the appearance becomes strong, the original color of the phosphor may be shifted in color, which is an obstacle to commercialization. In addition, when the pulling speed of the arc tube from the photocatalyst solution in the dipping tank is increased, the thickness of the photocatalyst film increases, and the photocatalytic film cracks during firing. Because it is not possible, the production speed cannot be increased more than a certain level. Further, since the photocatalytic chemical in the dip tank evaporates, it is difficult to control the concentration of the photocatalytic chemical in the dip tank, and it is difficult to handle, so that the production is troublesome.

The present invention has been made in order to solve the above-mentioned problems, and provides a light source with a photocatalyst, which can be produced with little interference color, can be produced at a high speed, and can be easily produced, and a method for producing the same. The purpose is to do.

[0006]

In order to achieve this object, according to the present invention, in a light source with a photocatalyst, a photocatalyst film in which flake-like particles having a diameter of 10 to 100 μm are superposed on the outer surface of an arc tube is formed. I do.

In a method for manufacturing a light source with a photocatalyst,
A photocatalyst solution having a droplet diameter of 5 to 30 μm is sprayed onto the outer surface of the arc tube from a spray nozzle, applied, and baked to form a photocatalytic film on the outer surface of the arc tube.

In this case, a titanium sol containing a titanium organic compound, an acid, water and an alcohol is used as the photocatalyst solution.

Further, an iron compound as the photocatalytic chemical solution;
An iron sol containing glycol and acid is used.

Further, the photocatalyst solution is applied while rotating the arc tube.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of a method for manufacturing a fluorescent lamp with a photocatalyst according to the present invention. In this method of manufacturing a light source with a photocatalyst, a photocatalytic chemical solution composed of a titanium sol obtained by diluting an alkoxide of titanium (Ti) with alcohol and hydrolyzing with an acid catalyst is supplied to a spray nozzle 2 through a hose 3, and is directly formed of glass. While rotating the tubular arc tube 1, the diameter of the droplet is 5 to 30 from the spray nozzle 2.
A photocatalytic chemical solution of μm is sprayed, the photocatalytic chemical solution is applied to the arc tube 1, dried, and fired at 500 ° C. to form a photocatalytic film on the outer surface of the arc tube 1.

FIG. 2 is a sectional view showing a part of a fluorescent lamp manufactured by the manufacturing method described with reference to FIG. 1, that is, a fluorescent lamp according to the present invention. As shown in the figure, a photocatalyst film 11 is formed on the outer surface of the arc tube 1 in a state where flake-like particles 11a of titanium oxide having a diameter of 10 to 100 μm and a thickness of 0.1 to 1 μm overlap.

In this photocatalyst-equipped fluorescent lamp and the method of manufacturing the same, micro-interference occurs with each of the titanium oxide flake-like particles 11a in the reflection of the photocatalyst film 11, and the reflected light from the photocatalyst film 11 Since the light is scattered light, almost no rainbow interference color appears on the appearance, so that the original color of the phosphor does not deviate in color and it is easy to control the light color to a constant. It is. Also, since the photocatalytic chemical is applied to the arc tube 1 by spraying,
Since the coating speed per arc tube can be improved as compared with the dipping method, the production speed can be increased. In addition, since the photocatalytic chemical is disposable, the concentration of the photocatalytic chemical can be easily controlled, and the production is easy. Further, since the photocatalyst chemical is sprayed while rotating the arc tube 1, the photocatalyst chemical can be applied to the arc tube 1 without unevenness, so that a homogeneous photocatalyst film 11 excellent in appearance can be obtained, and the photocatalyst can be applied. It is easier to control the light color of the fluorescent lamp to be constant. Further, since the photocatalyst solution obtained by diluting titanium alkoxide with alcohol and hydrolyzing with an acid catalyst is used, the photocatalyst film 11 can be fixed to the arc tube 1 without a binder, and the photocatalyst film 11 The purity of titanium oxide can be 90% or more. X-ray analysis of the crystal structure of the titanium oxide flake particles 11a of the photocatalytic film 11 showed that the crystal structure of the titanium oxide flake particles 11a was 100%.
It is an anatase type, has a good acetaldehyde removal rate, and has a high air cleaning effect.

FIG. 3 is a graph showing the change over time in the residual ratio of acetaldehyde when 10 ppm of acetaldehyde is sealed in the closed box. When a fluorescent lamp with a photocatalyst having a photocatalyst film formed by the spray method according to the present invention is inserted, a line c
Shows a case where a fluorescent lamp with a photocatalyst having a photocatalyst film formed by a conventional dip method is put in a closed box. As is clear from this graph, the acetaldehyde removal rate of the fluorescent lamp with a photocatalyst according to the present invention is as good as the conventional fluorescent lamp with a photocatalyst.

In the above-described embodiment, a photocatalytic chemical solution comprising a titanium sol obtained by diluting an alkoxide of titanium with an alcohol and hydrolyzing with an acid catalyst is used. However, a titanium sol containing a titanium organic compound, an acid, water and an alcohol is used. Can be used. In this case, it is desirable that the titanium concentration is 0.1 to 2 mol / l, the molar ratio of water / titanium is 0.1 to 10, and the equivalent ratio of water / acid is 2 to 40. Titanium isopropoxide or the like can be used as an alkoxide of titanium as a titanium organic compound, hydrochloric acid or the like can be used as an acid, and ethanol or the like can be used as an alcohol.

Further, a photocatalytic chemical solution comprising an iron sol containing an iron compound such as iron nitrate, a glycol such as ethylene glycol and an acid may be used. In this case, a photocatalytic film composed of an iron oxide film may be formed. The photocatalytic film can be fixed to the arc tube without a binder at the time of film formation,
Moreover, the iron oxide purity of the photocatalyst film can be made high.

Further, after forming a photocatalytic film on the arc tube,
It is also possible to bend and bond the arc tube.

In the above-described embodiment, the case where the light source with a photocatalyst is a fluorescent lamp with a photocatalyst has been described.
The present invention can also be applied to lamps such as gh intensity discharge lamps. In the above-described embodiment, the diameter of the droplet from the spray nozzle 2 is 5 mm.
Although a photocatalyst chemical solution of 〜30 μm was sprayed, it is desirable to spray a photocatalytic chemical solution having a droplet diameter of 5 to 10 μm from the spray nozzle 2.

[0019]

According to the light source with photocatalyst and the method of manufacturing the same according to the present invention, the reflected light from the photocatalyst film becomes scattered light as a whole, so that almost no interference color is produced, and the light source is provided with a light intensity less than the dip method. As a result, the application speed per arc tube can be improved, so that the production speed can be increased, and the control of the concentration of the photocatalytic chemical solution is easy, so that the production is easy.

Further, when a titanium sol containing a titanium organic compound, an acid, water and an alcohol is used as the photocatalytic chemical solution, the purity of the titanium oxide in the photocatalytic film can be increased.

When an iron sol containing an iron compound, a glycol and an acid is used as the photocatalyst solution, the iron oxide purity of the photocatalyst film can be increased.

When the photocatalyst solution is applied while rotating the arc tube, the photocatalyst solution can be applied to the arc tube without unevenness, so that a homogeneous photocatalyst film excellent in appearance can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a method for manufacturing a fluorescent lamp with a photocatalyst according to the present invention.

FIG. 2 is a sectional view showing a part of the fluorescent lamp according to the present invention.

FIG. 3 is a graph showing a temporal change of a residual ratio of acetaldehyde.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Arc tube 2 ... Spray nozzle 11 ... Photocatalytic film

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinichi Ichikawa 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Inside Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Yoshinori Furukawa 7-1 Omikacho, Hitachi City, Ibaraki Prefecture No. 1 Inside the Hitachi Research Laboratory, Hitachi, Ltd.

Claims (5)

[Claims] 1. A light source with a photocatalyst, wherein a photocatalyst film in which flake-like particles having a diameter of 10 to 100 μm are superposed on the outer surface of an arc tube is provided. 2. A photocatalyst solution having a droplet diameter of 5 to 30 μm is sprayed from a spray nozzle onto an outer surface of an arc tube, applied, and fired to form a photocatalyst film on the outer surface of the arc tube. A method for producing a light source with a photocatalyst, comprising: 3. A titanium organic compound as the photocatalytic chemical solution,
The method for producing a light source with a photocatalyst according to claim 2, wherein a titanium sol containing an acid, water and an alcohol is used. 4. The method for producing a light source with a photocatalyst according to claim 2, wherein an iron sol containing a compound of iron, a glycol and an acid is used as the photocatalytic chemical solution. 5. The method for producing a light source with a photocatalyst according to claim 2, wherein the photocatalyst solution is applied while rotating the arc tube.