JP5644039B2 - Fluorescent lamp emitting ultraviolet light and method for manufacturing the same - Google Patents

Description

  The present invention relates to a fluorescent lamp that emits light in the ultraviolet region and a method for manufacturing the fluorescent lamp.

Recently, ultraviolet light having a wavelength of about 300 nm has been used for photocatalysts and broad applications such as resin curing, sterilization, beauty, and medicine. As such a light source, a fluorescent lamp that emits ultraviolet rays in which a phosphor having an intensity peak in the vicinity of a wavelength of 250 to 380 nm is applied to the inner surface of the arc tube is used.
In such a fluorescent lamp that emits ultraviolet light, by obtaining ultraviolet light having a relatively short wavelength (for example, 200 nm or less) for exciting the phosphor by discharge, the ultraviolet light is irradiated onto the phosphor to fluoresce. Ultraviolet light obtained by exciting the body and converting it into light of a predetermined wavelength range is transmitted through the phosphor layer and arc tube, and is emitted in principle, as in the case of obtaining visible light It is.

In general, so-called hard glass such as soda glass, borosilicate glass, and aluminosilicate glass is suitably used as the arc tube of the fluorescent lamp.
However, for example, in a fluorescent lamp that emits ultraviolet light having a wavelength in the vicinity of 250 to 380 nm, when the hard glass described above is used in the arc tube, ultraviolet light is absorbed, so that the transmittance of ultraviolet light is low and the efficiency is low. End up. Accordingly, the glass constituting the arc tube is preferably one having a higher ultraviolet light transmittance.

  In view of such circumstances, for example, Patent Documents 1 and 2 disclose fluorescent lamps using quartz glass as the arc tube. Like the techniques described in these documents, if the arc tube is made of quartz glass, the transmittance of ultraviolet light is high and light can be extracted efficiently.

Special table 2008-503046 gazette Special table 2007-534128 gazette

By the way, in general, a fluorescent lamp includes a step of fixing the phosphor by raising the temperature to the vicinity of the softening point of the glass constituting the base material of the arc tube in the manufacturing process. However, since quartz glass has a softening point of around 1600 ° C., when heated to such a high temperature range, there is a problem in that the phosphor is deteriorated and predetermined light cannot be obtained.
In view of this, when the firing temperature of the phosphor is lowered to a temperature range where there is no problem with the light emission characteristics, for example, 900 ° C. or less, the quartz glass cannot be softened, and the phosphor layer peels off from the tube wall and falls. A predetermined light distribution cannot be obtained.

  Accordingly, the present invention provides a fluorescent lamp that emits ultraviolet light and has a quartz tube in the arc tube so as to obtain an efficient fluorescent lamp with high ultraviolet light transmittance and no problems such as peeling or dropping of the phosphor. An object of the present invention is to provide a highly reliable fluorescent lamp.

Therefore, the fluorescent lamp according to the present invention is a fluorescent lamp that emits ultraviolet rays,
The arc tube is made of quartz glass,
A layer of glass powder having a softening point lower than that of quartz glass is baked, and a glass layer formed by being bonded on the discharge space side surface of the arc tube,
And a phosphor layer that is formed on the surface of the glass layer and emits ultraviolet light when excited.
The glass layer preferably contains either borosilicate glass or aluminosilicate glass.
The average thickness of the glass layer is preferably 1 to 30 μm.

Further, the manufacturing method of the fluorescent lamp of the present invention is a manufacturing method of a fluorescent lamp that emits ultraviolet rays,
Prepare a tube made of quartz glass as the arc tube,
In the quartz glass tube, a layer of glass powder having a softening point lower than that of quartz glass is baked to previously form a glass layer bound to the quartz glass tube ,
Apply a phosphor suspension in which a phosphor and a binder agent are mixed on the glass layer ,
The quartz glass tube, the glass layer, and the phosphor are fired.
Further, the glass powder having a softening point lower than that of the quartz glass may include one of borosilicate glass and aluminosilicate glass.

According to the fluorescent lamp of the present invention, a glass layer made of glass having a softening point lower than the softening point of quartz glass is formed between the quartz glass arc tube and the phosphor layer. It can be baked without being heated to a temperature of ℃ or higher, and it becomes a fluorescent lamp with less phosphor deterioration and good conversion efficiency to ultraviolet light, and a glass interposed between the phosphor layer and the arc tube Since it is softened, it is possible to strengthen the bonding between the phosphor layer and the arc tube, and to obtain a fluorescent lamp in which the phosphor layer is not peeled off or dropped off and illuminance unevenness does not occur. it can. Moreover, since the arc tube is made of quartz glass, a fluorescent lamp having good ultraviolet light transmittance and high ultraviolet light radiation efficiency can be obtained.
And when the said glass layer contains at least any glass among borosilicate glass (Si-B-O type | system | group glass) and aluminosilicate glass (Si-Al-O type | system | group glass), thermal shock resistance is favorable. Therefore, the phosphor layer can withstand temperature changes when used as a fluorescent lamp, without causing problems such as peeling off of the glass layer or bonding with the phosphor layer. Can be held.
Furthermore, when the average thickness of the glass layer is 1 to 30 μm, the phosphor layer can be reliably held, and the fluorescent lamp can be made highly efficient without impairing the transmittance of ultraviolet rays.

  According to the fluorescent lamp manufacturing method of the present invention, a glass layer made of glass having a softening point lower than the softening point of quartz glass is formed between the quartz glass arc tube and the phosphor layer, and thereafter Since the phosphor layer is formed on the substrate, the firing temperature of the phosphor can be set relatively low, the phosphor is less deteriorated and the conversion efficiency to ultraviolet light is good, and the glass is softened. By doing so, the phosphor layer and the arc tube are strongly bonded, the phosphor layer is not peeled off or dropped off, and a fluorescent lamp in which unevenness in illuminance does not occur can be obtained. As a result, it is possible to easily and reliably obtain a fluorescent lamp whose arc tube is made of quartz glass, which has good ultraviolet light transmittance and high ultraviolet light radiation efficiency.

[First Embodiment]
An embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 is a flowchart explaining the manufacturing process of this fluorescent lamp, FIG. 2 is a glass tube which is a material for the arc tube of the lamp, FIG. 3 is a cross-sectional view cut perpendicularly to the tube axis and explaining the manufacturing process of the arc tube FIG. 4 is an explanatory sectional view showing the entire fluorescent lamp according to the present invention. As can be seen from FIGS. 2 to 4, in the fluorescent tube 11 of the fluorescent lamp according to the first embodiment, the inner tube 111 and the outer tube 112 are arranged substantially coaxially, and both end portions 11A and 11B are sealed. Thus, a cylindrical discharge space S is formed inside. In the present embodiment, the arc tube 11 constituting glass tube 80 is made of fused silica glass.

  Hereinafter, a method for manufacturing a fluorescent lamp according to the present invention will be described with reference to FIGS. 2 to 4 according to the flowchart of FIG.

1. A slurry in which glass powder for constituting the glass layer is dispersed is manufactured (step 1).
The glass block constituting the glass block is crushed into pieces and applied to a ball mill. The particle size is classified by applying the pulverized glass powder to a mesh, and a glass powder having an average particle size of 0.5 to 10 μm (preferably 1 to 5 μm) is produced.
This glass powder is mixed with nitrocellulose and butyl acetate solution at a weight ratio of 1: 4. The mixed solution is ball milled with alumina balls and sufficiently milled to produce a slurry in which glass powder is dispersed. Hereinafter, the slurry in which the glass powder is dispersed is referred to as “glass slurry”.
The glass which comprises a glass layer is glass which has a softening point lower than the softening point (1600 degreeC) of quartz glass used as the base material of an arc_tube | light_emitting_tube. Preferably, the glass has a softening point in the range of the firing temperature (400 to 900 ° C.) of the phosphor, and more preferably a hard glass with good thermal shock resistance.
Of these, borosilicate glass (Si—B—O-based glass, softening point: about 800 ° C.) and aluminosilicate glass (Si—Al—O-based glass, softening point: about 900 ° C.) are preferable, and such hard glass. May be used singly or as a mixture at an appropriate ratio.

2. Then, a glass slurry is apply | coated to the inner surface of the glass tube for arc tube structure (step 2).
In the present embodiment, the arc tube constituting glass tube 80 includes an inner tube 81 and an outer tube 82 such that the discharge space is cylindrical as shown in FIG. Exhaust pipes 83A and 83B communicating with the outside are formed at both ends in the longitudinal direction of the glass pipe 80). The arc tube constituting glass tube 80 is held vertically, and one of the exhaust pipes 83B, for example, is placed in the liquid level of the container filled with the glass slurry, and suction is performed from the one exhaust pipe 83A to suck up the glass slurry. The inside of the tube 80 is filled with glass slurry, and then is extracted from the other exhaust tube 83B and applied. The thickness of the glass layer finally obtained can be changed by adjusting the viscosity of the glass slurry and the number of coatings. At this time, the thickness of the glass slurry is preferably formed in the range of 1 to 30 μm. In addition, in order to obtain a high transmittance with respect to predetermined ultraviolet light, it is preferable that the thickness of the glass layer is as small as possible as long as the phosphor formed in the post-process can be held.

3. The glass slurry is dried (step 3).
By flowing dry nitrogen gas from one exhaust pipe 83A of the arc tube constituting glass tube 80 to the other exhaust pipe 83B, butyl acetate contained in the glass slurry is evaporated. As a result, a layer in which glass powder having a thickness of 1 to 30 μm is deposited on the inner surface of the glass tube 80 is formed. The gas used for drying may be dry air.

4). The glass tube is heated to fire the glass powder layer (step 4).
Firing conditions are in the atmosphere, about 500 to 1000 ° C., and the time is 0.2 to 1 hour in terms of holding time at the maximum temperature. When the above-described borosilicate glass or aluminosilicate glass is used, it is preferably performed at 600 to 900 ° C. The particles are bonded to each other by this baking process, and are fused to the glass tube, so that the glass layer is strongly bonded to the substrate.
The glass layer is normally maintained in a powdery form because it does not rise to the melting temperature, but it may be melted at a higher temperature.

5. The glass tube is cooled to room temperature (step 5), and the prepared phosphor slurry is applied into the arc tube by the suction method (step 6).
As for the method of applying the phosphor, see 2. The procedure is the same as that described above, and the glass tube 80 for arc tube construction is held vertically, and one of the exhaust pipes 83B, for example, is placed on the liquid surface of the container filled with the phosphor slurry, and from one exhaust pipe 83A Suction is performed, the phosphor slurry is sucked up, and the phosphor slurry is filled in the inside of the suction tube 80, and then is removed from the other exhaust pipe 83B and applied.
Examples of the phosphor that can be suitably used in the fluorescent lamp according to the present invention include a europium-activated strontium borate (Sr—B—O: Eu (hereinafter referred to as SBE) phosphor having a central wavelength of 368 nm), Cerium-activated magnesium lanthanum aluminate (La-Mg-Al-O: Ce (hereinafter referred to as LAM), center wavelength 338 nm (but broad)) phosphor, gadolinium, praseodymium-activated lanthanum phosphate (La-P-) O: Gd, Pr (hereinafter referred to as LAP: Pr, Gd, center wavelength 311 nm) phosphors, etc. Each of these phosphors absorbs ultraviolet light having a wavelength of less than 250 nm, and has a respective center It is converted into ultraviolet rays in the wavelength band and emitted.

6). The phosphor slurry is dried by removing moisture (step 7).
By flowing dry nitrogen gas from one exhaust pipe 83A of the arc tube constituting glass tube 80 to the other exhaust pipe 83B, butyl acetate contained in the phosphor slurry is evaporated. The gas used for drying may be dry air.

7). The phosphor is fired (step 8).
A glass tube for the arc tube is placed in a furnace and fired. Firing conditions are about 500 to 800 ° C. in the atmosphere, and heating is performed for 0.2 to 1 hour as a holding time at the maximum temperature. In this firing step, the softening of the glass occurs at the interface between the phosphor layer and the glass layer, and the phosphor is bound to the glass layer, resulting in a strong bonded state.
As a result, as shown in FIG. 3, the glass layer 14 made of the low softening point glass powder and the phosphor layer 15 are laminated in this order on the inner surface of the glass tube 80 for the arc tube construction made of quartz glass. Is obtained.
In the case of a phosphor that is severely deteriorated in the air, the temperature is raised to a temperature at which nitrocellulose is burned out in the air, and then heated to about 800 ° C. in a non-oxidizing atmosphere or a reducing atmosphere. It is possible.

8). The glass tube is cooled to room temperature (step 9), and a rare gas is sealed inside the glass tube and hermetically sealed (step 10).
More specifically, after removing the phosphor layer 15 and the glass layer 14 attached to the inner surfaces of the exhaust pipes 83A and 83B, one of the exhaust pipes 83A is heat-sealed and exhausted from the other exhaust pipe 83B. A predetermined rare gas (filled material) is sealed and hermetically sealed (chip off). As a result, a fluorescent lamp arc tube 11 having a cylindrical airtight discharge space S as shown in FIG. 4 is obtained. The rare gas to be sealed is, for example, xenon (Xe), krypton (Kr), argon (Ar), or neon (Ne), and may be used alone or in a suitable combination. The wavelengths obtained by discharging these rare gases are xenon 160-190 nm, krypton 124, 140-160 nm, argon 107-165 nm, and neon 80-90 nm.

9. Subsequently, the inner electrode is disposed along the inner peripheral surface of the inner tube, and the outer electrode is disposed along the outer peripheral surface of the outer tube (step 11).
A pair of external electrodes composed of the inner electrode 12 and the outer electrode 13 are arranged on the arc tube 11 obtained in step 10 to complete the excimer lamp 10. The inner electrode 12 is formed, for example, by placing two metal plates having a C-shaped cross section facing each other and along the inner peripheral surface of the inner tube 111. The outer electrode 13 is made of, for example, a mesh electrode and is disposed so as to cover the entire outer surface of the outer tube 112.

  In the fluorescent lamp described above, the pair of electrodes are both positioned outside the discharge space. However, the present invention is not limited to such an example. For example, at least one electrode may be disposed inside. Applicable. In addition, when arrange | positioning an electrode in discharge space, what is necessary is just to attach an electrode before the arc tube sealing process (step 8).

Specific dimensions of the final product dimensions of the fluorescent lamp thus obtained are as follows.
The total length of the arc tube (11) is about 300 to 2000 mm, the thickness of the inner tube (111) is 1 to 2 mm, and the thickness of the outer tube (112) is 2 to 3 mm. The average thickness of the phosphor layer (15) is 10 to 20 μm, and the thickness of the glass layer (14) made of low softening point glass formed between the phosphor layer (14) and the arc tube (11). Length: 1 to 30 μm.

  In the fluorescent lamp shown in FIG. 4, the inner electrode 12 and the outer electrode 13 are arranged to face each other with the inner tube 111, the outer tube 112, and the discharge space S interposed therebetween. Lead wires W11 and W12 are connected to the inner electrode 12 and the outer electrode 13, and a power supply device 16 is connected. When a high frequency voltage is applied from the power supply device 16, a dielectric (111, 112) and the like, and ultraviolet light having a wavelength of 172 nm is generated by light emission of a discharge gas such as xenon (Xe) gas. The ultraviolet light obtained here is light emission for excitation of the phosphor, and the phosphor is excited by irradiating the phosphor layer with this ultraviolet light having a wavelength of 172 nm. For example, by selecting the type of the phosphor Ultraviolet light having a wavelength of 250 to 380 nm is emitted. The ultraviolet light having a wavelength of 250 to 380 nm thus obtained is transmitted through the phosphor layer 15, the glass layer 14, the arc tube 11, and the outer electrode 13 (void portion) in this order, and is emitted to the outside.

  The glass layer 14 is inferior to quartz glass in the transmittance of ultraviolet light, but the thickness of the layer 14 is about 30 μm or less at the maximum. Accordingly, the absorption of ultraviolet light having a wavelength of 250 to 380 nm is small, and most of the light is transmitted and emitted to the outside. As a result, it becomes possible to radiate ultraviolet light of a desired wavelength band with much higher efficiency than that of the whole arc tube made of glass having a low softening point.

  Note that vacuum ultraviolet light having a wavelength of 172 nm generated by discharge of xenon gas has almost no absorption edge of borosilicate glass or aluminosilicate glass used for the glass layer in the 200 nm range. Accordingly, there is no possibility that ultraviolet light having a short wavelength which is not required is emitted to the outside.

Examples of the present invention will be described below, but the present invention is not limited to the following.
[Example 1]
<Preparation of glass slurry liquid>
A glass prepared by mixing borosilicate glass (Si—B—O-based glass) and aluminosilicate glass (Si—Al—O-based glass) at a ratio of 1: 1 is finely pulverized and then subjected to a ball mill to obtain an average particle size of 1. Prepared to a particle size of ˜5 μm.
This mixed glass powder was mixed with a mixed solution of butyl acetate and nitrocellulose at a weight ratio of 1: 4, and further stirred with a ball mill to prepare a slurry in which the glass powder was dispersed. The slurry in which the glass powder is dispersed is referred to as “glass slurry A”.

<Preparation of rare gas fluorescent lamp>
Subsequently, a rare gas fluorescent lamp according to Example 1 was manufactured according to the configuration shown in FIG. Note that a detailed description of the configuration described above in the embodiment is omitted.
On the inner surface of a glass tube made of fused silica glass for arc tube construction, glass slurry A was applied by a suction method and dried. Then, it baked by hold | maintaining at 700 degreeC for 1 hour. After firing, it was confirmed that powdered glass was appropriately melted on the inner surface of the glass tube and fixed in a state of being welded to the inner surface of the arc tube.
Subsequently, a phosphor slurry was prepared using LAP: Pr, Gd as the phosphor, and the slurry liquid was sucked up and applied onto the inner surface of the glass tube on which the glass layer was formed by a natural drop method. After drying the phosphor slurry, the phosphor was fired by heating at 500 ° C. for 1 hour. After that, after sealing one end of the glass tube, a rare gas (Xe gas (xenon gas)) is sealed at 27 kPa (200 Torr) under static pressure, and the other end is hermetically sealed to form a discharge space S. The arc tube 11 was manufactured.
In the arc tube 11, the outer tube 112 had an outer diameter of 30 mm and an inner diameter of 28 mm (wall thickness 2 mm), and the inner tube 111 had an outer diameter of 20 mm and an inner diameter of 18 mm (wall thickness 1 mm).
After the arc tube was hermetically sealed, a mesh electrode was disposed on the outer peripheral surface of the outer tube, and an aluminum foil electrode was disposed on the inner surface of the inner tube.

[Comparative Example 1-1]
A rare gas fluorescent lamp according to Comparative Example 1-1 was produced in the same manner as in Example 1 except that the phosphor slurry was directly applied to the quartz glass tube without using the glass slurry liquid. The phosphor was fired at 500 ° C. for 1 hour.

[Comparative Example 1-2]
A comparative example having the same configuration and procedure as in Example 1 except that the phosphor slurry was directly applied to the quartz glass tube without using the glass slurry liquid, and the firing condition of the phosphor was 1000 ° C. for 1 hour. A rare gas fluorescent lamp according to 1-2 was produced.

[Example 2]
<Preparation of glass slurry liquid>
Borosilicate glass (Si—B—O-based glass) was finely pulverized and then subjected to a ball mill to prepare an average particle size of 1 to 5 μm.
This borosilicate glass powder was mixed with a mixed solution of butyl acetate and nitrocellulose at a weight ratio of 1: 4, and further stirred with a ball mill to prepare a slurry in which the glass powder was dispersed. The slurry in which the glass powder is dispersed is referred to as “glass slurry B”.

<Preparation of rare gas fluorescent lamp>
Using the glass slurry B, an external electrode type rare gas fluorescent lamp (20) having the shape shown in FIG. 2A is a cross-sectional view cut perpendicularly to the axis of the tube, and FIG. 3B is a cross-sectional view taken along the line AA in FIG. Details will be described below.
The glass tube for the arc tube (21) had an outer diameter of 10 mm, an inner diameter of 9 mm (thickness of 0.5 mm), a total length of 1500 mm, and was made of fused silica glass. The glass slurry B was sucked up and applied to the glass tube by a natural dropping method, and the liquid was dried. Then, it baked by hold | maintaining at 600 degreeC for 1 hour. The glass tube after firing is fixed by melting the powdered glass appropriately and welding it to the inner surface of the glass tube.
An appropriate amount of phosphor powder was mixed with a small amount of a mixed solution of nitrocellulose and butyl acetate to prepare a suspension in which the fluorescent material was dispersed so that the viscosity was 20 mPa · s. Here, LAM was used as the phosphor. The phosphor slurry was an emulsion dispersion.
The phosphor slurry was sucked up and applied to a glass tube with a predetermined glass layer formed on the inner surface by a natural dropping method. After drying the phosphor slurry, the phosphor was fired by heating at 500 ° C. for 1 hour.
After sealing one end of the glass tube, a rare gas is sealed at 21 kPa (160 Torr) under static pressure, and a glass layer 24 made of glass having a softening point lower than that of quartz glass is formed on the inner surface of the arc tube 21. The arc tube 21 in which the layers 25 were laminated in this order was obtained. A silver paste is applied and formed on the outer surface of the arc tube 21 with a width of 2 mm and a length of 1450 mm, and a pair of external electrodes 22, 23 extending on the outer surface of the arc tube 21 in the length direction of the tube. The noble gas fluorescent lamp 20 according to Example 2 was manufactured. The lead wires W21 and W22 were connected to the one and the other electrodes 22 and 23, and were connected to a predetermined power source 26 for the rare gas fluorescent lamp 20.

[Comparative Example 2-1]
A rare gas fluorescent lamp was produced in the same manner as in Example 2 except that the phosphor slurry was directly applied to the quartz glass tube without using the glass slurry solution, and the rare gas fluorescent lamp according to Comparative Example 2-1 was manufactured. Was made. The phosphor was fired at 600 ° C. for 1 hour.

[Comparative Example 2-2]
A comparative example was applied in the same manner as in Example 2 except that the phosphor slurry was directly applied to the quartz glass tube without using the glass slurry solution, and that the firing condition of the phosphor was 1000 ° C. for 1 hour. A rare gas fluorescent lamp according to 2-2 was produced.

In Examples 1 and 2 above, xenon (Xe) gas is used as the discharge gas, and light having a wavelength of 172 nm is obtained by discharge with a dielectric interposed therebetween, and this is converted into ultraviolet light having a wavelength band of 300 nm or more by a phosphor. An example of conversion has been described. The present invention is not limited to these rare gas fluorescent lamps, and can also be applied to low-pressure mercury lamps. Other embodiments will be described below.
[Example 3]
Subsequently, an internal electrode type low-pressure mercury fluorescent lamp according to Example 3 was manufactured according to the configuration of FIG.
The glass tube for constituting the arc tube was fused silica glass. The glass slurry A obtained by the same method as in Example 1 was applied to the inside of the glass tube by a suction method, dried, and then fired at 700 ° C. for 1 hour.
Thereafter, a phosphor slurry is prepared using SBE as a phosphor, and the phosphor slurry is sucked up and applied by a natural drop method as described above, and the phosphor slurry is dried and then baked at 500 ° C. for 1 hour. The body was fixed to the glass tube.
Thereafter, filament mounts (32, 33) obtained by activating (Ba, Sr, Ca) O and triple carbonate at the end of the arc tube were disposed. A low pressure mercury fluorescent lamp as shown in FIG. 6 was finally obtained by sealing the inside of the glass tube with 4 kPa (30 Torr) of rare gas argon and 10 mg / cm ^{3 of} mercury and hermetically sealing it. In this embodiment, since mercury is used as the discharge material, ultraviolet rays having a wavelength band of 185 nm, 254 nm, 320-370 nm, etc. can be obtained. However, in the low-pressure mercury lamp according to Example 3, the energy of wavelengths of 185 nm and 254 nm occupies most of the radiation, so that it is not expected to emit light in the 300 nm range. Converting light with a wavelength of 185 nm and wavelength of 254 nm into light with a wavelength of about 300 nm using a phosphor is much more efficient than using only light with a wavelength in the vicinity of 320-370 nm obtained only by ordinary mercury discharge. Light with a wavelength of about 300 nm can be emitted.

Here, the configuration of the low-pressure mercury fluorescent lamp will be described with reference to FIG.
In this example, the arc tube 31 had an outer diameter of φ10 mm, an inner diameter of φ8.8 mm (wall thickness of 0.6 mm), and a total length of 1200 mm. The internal electrodes 32 and 33 made of a filament mount are supported by the arc tube 31 by sealing members 37 and 38 and are arranged to face each other. Lead wires W31 and W32 were connected to these internal electrodes 32 and 33, and were connected to a predetermined power supply device (not shown).
The glass layer 34 and the phosphor layer formed on the inner surface of the arc tube 31 had average thicknesses of 10 μm and 15 μm, respectively.

[Comparative Example 3-1]
An internal electrode fluorescent lamp according to Comparative Example 3-1 was produced in the same manner as in Example 3 except that the phosphor slurry was directly applied to the quartz glass tube without using the glass slurry liquid. The phosphor was baked under the same conditions as in Example 3 at 700 ° C. for 1 hour.

[Comparative Example 3-2]
Comparative Example 3-2 was performed in the same manner as in Example 3 except that the phosphor slurry was directly applied to the quartz glass tube without using the glass slurry liquid, and the firing temperature of the phosphor was 1000 ° C. for 1 hour. An internal electrode fluorescent lamp according to the present invention was produced.

[Experimental Example 1]
The lamp was turned on using a lighting power source suitable for each fluorescent lamp, and the ultraviolet illuminance was measured. The ultraviolet illuminance was measured using a spectroscope (USR40, manufactured by USHIO INC.) At the center position of the lamp length and the light receiver placed at a position 20 mm away from the tube wall of the arc tube. The ultraviolet illuminance of the fluorescent lamps of Examples 1, 2, and 3 was set to 100, and the ultraviolet illuminance of the lamp of the comparative example was expressed as a relative value. The results are shown in the column of “UV illuminance” in Table 1.

[Experiment 2]
Furthermore, the fluorescent lamps according to Examples 1 to 3 and the fluorescent lamps according to Comparative Examples 1-1 to 3-2 were evaluated for adhesion of the phosphors. When the lamp was dropped from 5 cm on a wooden board, it was easily peeled off: x, when partially peeled: △, when not peeled at all: ○ Is.
The results are shown in the column of “Adhesion” in Table 1 below.

  The lamps according to Examples 1, 2, and 3 were found to be excellent in both ultraviolet illuminance and adhesion. In the lamps according to Comparative Examples 1-1, 2-1, and 3-1, since the glass layer is not provided, the transmittance of the ultraviolet light is better than that of the lamp of the example, but the adhesion of the phosphor layer is high. It was bad. Even when the lamp was lit, peeling and falling occurred, and as a result, the desired illuminance could not be obtained. On the other hand, each of the lamps of Comparative Examples 2-2 and 3-2 in which the firing temperature was set to around 1000 ° C. near the softening point of quartz glass was sufficient for the adhesion of the phosphor layer, but the phosphor was excited. The state was not obtained, and as a result, the desired ultraviolet light could not be obtained and the lamp with the lowest ultraviolet illuminance was obtained. In addition, since the lamp of Comparative Example 1-2 was set at a temperature lower than that of Other Comparative Examples 2-2 and 3-2 and 800 ° C., the adhesion of the phosphor was not good.

The above embodiment is merely an example for carrying out the present invention, and it goes without saying that it can be changed as appropriate.
For example, in Examples 1 to 3 described above, as the phosphor, SBE (Sr—B—O: Eu), LAM (La—Mg—Al—O: Ce), LAP: Pr, Gd (La—P—O) are used. : Gd, Pr) are used as examples, but any of these phosphors may be used in the lamp having the configuration according to each embodiment, and these phosphors are appropriately used. It is also possible to mix and use at a ratio of. Of course, as long as the wavelength of the radiated light obtained by light emission and the wavelength of the ultraviolet light after conversion are appropriate, other phosphors can be used without being limited to the above.

FIG. 1 is a flowchart for explaining the manufacturing process of the fluorescent lamp of the present invention. It is a sectional view in the tube axis direction of the arc tube. It is a sectional view in the direction perpendicular to the tube axis of the fluorescent lamp arc tube according to the present invention. It is sectional drawing for description which cut | disconnected the arc tube for fluorescent lamps which concerns on this invention along the tube axis. It is sectional drawing cut | disconnected in the direction perpendicular | vertical to the (a) tube-axis direction of the external electrode type | mold fluorescent lamp which concerns on this invention, (b) tube axis. 1 is a sectional view in the tube axis direction of an internal electrode type mercury fluorescent lamp which is an embodiment of the present invention.

Explanation of symbols

10 rare gas fluorescent lamp 11 arc tube 12 inner electrode 13 outer electrode 14 low softening point glass layer 15 phosphor layer 16 power source 20 noble gas fluorescent lamp 21 arc tube 22 one electrode 23 other electrode 24 low softening point glass layer 25 fluorescence Body layer 26 Power supply 30 Low-pressure mercury fluorescent lamp 31 Arc tube 32 One electrode 33 The other electrode 34 Low softening point glass layer 35 Phosphor layer 37 Seal member 38 Seal member W11, W12 Lead wires W21, W22 Lead wires W31, W32 Lead line

Claims (5)

A fluorescent lamp that emits ultraviolet rays,
The arc tube is made of quartz glass,
A layer of glass powder having a softening point lower than that of quartz glass is baked, and a glass layer formed by being bonded on the discharge space side surface of the arc tube,
A fluorescent lamp that emits ultraviolet light, comprising a phosphor layer that is formed on the surface of the glass layer and emits ultraviolet light when excited.   The fluorescent lamp according to claim 1, wherein the glass layer includes one of borosilicate glass and aluminosilicate glass.   The fluorescent lamp according to claim 1 or 2, wherein the glass layer has an average thickness of 1 to 30 µm. A method of manufacturing a fluorescent lamp that emits ultraviolet rays;
Prepare a tube made of quartz glass as the arc tube,
In the quartz glass tube, a layer of glass powder having a softening point lower than that of quartz glass is baked to previously form a glass layer bound to the quartz glass tube ,
Apply a phosphor suspension in which a phosphor and a binder agent are mixed on the glass layer ,
A method for producing a fluorescent lamp emitting ultraviolet rays, comprising firing the quartz glass tube, the glass layer, and the phosphor. The method of manufacturing a fluorescent lamp according to claim 4, wherein the glass powder having a softening point lower than that of the quartz glass includes any one of borosilicate glass and aluminosilicate glass.

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