JP3644302B2 - Fluorescent lamp - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluorescent lamp that is lit at a high load.
[0002]
[Prior art]
In recent years, various fluorescent lamps such as compact fluorescent lamps and bulb-type fluorescent lamps have been put on the market in addition to conventional straight fluorescent lamps and round fluorescent lamps. In addition, the compact design of the fluorescent lamp contributes to the production of various lighting spaces by saving space, increasing brightness, and increasing output.
[0003]
In order to make the conventional fluorescent lamp compact, the diameter of the arc tube is reduced, the straight glass tube is heated and bent (bending), and two glass tubes are bridge-joined. In particular, using a technology that bridges two glass tubes and obtains twice the light emitting area, 4 glass tubes, 6 or 8 tubes are joined, and the discharge path length is long and compact. Fluorescent lamps have been developed.
[0004]
In recent years, fluorescent lamps using straight arc tubes have been saved in space, and arc tubes using straight glass tubes having an outer diameter of 16 mm or less have been developed.
[0005]
Various types of glass are used in the fluorescent tube of fluorescent lamps, and it is necessary to consider that the physical properties such as expansion coefficient, softening temperature, working temperature, etc. differ depending on the glass composition, and glass workability. . In addition, it is necessary to consider the low cost, strength and durability. In general, soda-lime glass that can be obtained at a low price and appropriate strength, and lead glass with better workability are mainly used as arc tube materials. Since such glass has a low processing temperature, it is possible to easily form a bent arc tube.
[0006]
[Problems to be solved by the invention]
Conventional fluorescent lamps have a problem in that, as the size of the fluorescent lamp decreases, the luminous flux maintenance factor decreases, and black spots and darkening occur as the lighting time elapses. In addition, there is a problem that the luminous flux maintenance factor is remarkably lowered by high output lighting by high frequency, lighting in an envelope made of a glove and a case, or a sealing device such as a ceiling. The decrease in the luminous flux maintenance factor is considered to be caused by adsorption of mercury existing in the discharge space to the inner wall of the arc tube, coloring of glass by ultraviolet rays, reduction in luminance of the phosphor, and the like. Among them, fluorescent lamps with high tube wall load expressed by lamp power consumption per arc tube area are particularly prominent in arc tube blackening and black spots caused by mercury compounds during lighting, and therefore maintain the luminous flux. The rate decline is also significant.
[0007]
In particular, in a light bulb-type fluorescent lamp in which an arc tube is provided in an envelope made up of a globe and a case, the tube wall temperature of the arc tube reaches 100 ° C. or more during lighting, so the luminous flux maintenance factor The decline of In addition, the compact fluorescent lamp in which the glass tube is bent or joined by a bridge has a problem that the glass-processed portion is markedly colored during lighting and the appearance is impaired.
[0008]
In this way, the electrical and temperature load on the arc tube tends to increase in recent years as the output of the fluorescent lamp increases, improving the luminous flux maintenance factor of the high-load fluorescent lamp and extending the service life. Longer length is desired.
[0009]
On the other hand, soda lime glass, which is inexpensive and has good workability, has been used as a fluorescent tube arc tube material as a glass composition for a glass tube used in such an arc tube of a fluorescent lamp. However, this soda-lime glass has a very high sodium content. Sodium is indispensable for improving the glass workability, but if the content is large, the glass workability is improved, but sodium tends to precipitate on the glass surface. Accordingly, when a large amount of sodium is contained, mercury tends to adhere to the inner surface of the arc tube, which causes coloring inside the arc tube.
[0010]
For example, in the case of a thin fluorescent lamp with an arc tube having an inner diameter of 15 mm or less, or a compact fluorescent lamp having a high tube wall load, the luminous flux maintenance factor is significantly reduced.
[0011]
This is because the area inside the arc tube with respect to the power consumption is extremely small, so that the ultraviolet intensity per unit area, ion bombardment, and temperature load become so large that they cannot be compared with a conventional fluorescent lamp.
[0012]
FIG. 1 shows the load on the tube wall of various fluorescent lamps and the luminous flux maintenance factor of the lamp. As is apparent from FIG. 1, in the conventional fluorescent lamp indicated by symbol x, the tube wall load is 0.13 W / cm.²From the above, it can be seen that the luminous flux maintenance factor is extremely lowered. Tube wall load is 0.13 W / cm²The above is equivalent to a so-called compact fluorescent lamp having two or more bridge joints or two or more bent portions having an arc tube inner diameter of 15 mm or less.
[0013]
In addition, lead glass as a conventional arc tube material generally has a composition of PbO of 20% or more, Na₂O is contained in an amount of about 6 to 10%, has good workability and durability, and is relatively inexpensive. Therefore, it is used in various fluorescent lamps. However, since it contains lead, it is necessary to suppress the use of lead in consideration of the global environment. As disclosed in Japanese Patent Application Laid-Open No. 6-206737, a composition of a glass for electric lamps as an alternative to this lead glass has been reported. However, such a tube wall load is 0.13 W / cm.²However, it was insufficient to improve various drawbacks when applied to high fluorescent lamps.
[0014]
In addition, in order to improve the disadvantages of fluorescent lamps using glass containing a lot of sodium, it is known that a protective film is provided on the inner surface of the glass tube to prevent mercury from adhering and to improve lamp characteristics such as luminous flux maintenance factor. It has been. A commonly used material is coated with a metal oxide layer such as alumina or silica. However, in a fluorescent lamp with a high tube wall load, the bulb must be coated with a thickness of 1 μm or more in order to maintain the performance, but there is a problem that the fluorescent film is liable to be peeled off in the bulb processing step.
[0015]
The present invention has been made to solve such a problem, and has good workability, and can improve the luminous flux maintenance factor by preventing darkening and black spots of a fluorescent lamp having a high tube wall load. The object is to provide a long-life compact fluorescent lamp.
[0016]
[Means for Solving the Problems]
  In the fluorescent lamp according to the first aspect of the present invention, mercury and a rare gas are enclosed in a glass tube having an inner surface coated with a phosphor layer, and the tube wall load is 0.13 W / cm.²And the glass tube has a weight ratio of SiO₂57% to 78%, BaO over 0% to 6%, SrO 2% to 10%, CaO0 or more6% or less, MgO0 or more6% or less, Na₂O is 4% to 11%, K2O is 2% to 11%, Li₂O0 or more4% or less, B₂O_Three0.5% to 3%, P₂O_FiveThe0 or moreLess than 3%, Al₂O_Three1% to 6%, Sb₂O_ThreeMore than 0% and 1.5% or less, Fe₂O_ThreeThe0 or more0.5% or less, SO_ThreeThe0 or moreIncluding 0.5% or lessThe combined weight ratio of BaO and SrO is 11% or less, and the weight ratio of BaO and SrO is B ₂ O _Three , P ₂ O _Five Is 1/2 or lessIt has a configuration.
[0017]
As a result, it has the same level of workability, strength, and durability as conventional soda glass, and also reduces the diffusion of sodium in the glass to the inner wall of the arc tube, thereby reducing the luminous flux and luminous flux that are the characteristics of fluorescent lamps. The maintenance rate can be significantly improved.
[0018]
According to a second aspect of the present invention, in the fluorescent lamp according to the first aspect, the arc tube is housed in a glass or resin globe.
[0019]
As a result, it is possible to prevent the occurrence of darkening and black spots in a fluorescent lamp having a bent arc tube at high temperature lighting with the arc tube envelope sealed, and to improve the luminous flux maintenance factor.
[0020]
A third aspect of the present invention is the fluorescent lamp according to the first or second aspect, wherein a protective film is formed between the inner surface of the glass tube and the phosphor layer.
[0021]
As a result, the processing characteristics can be maintained, and further, the coloring of glass, the adsorption of mercury, and the movement of sodium can be prevented, so that the luminous flux maintenance factor of the fluorescent lamp can be greatly improved.
[0022]
According to a fourth aspect of the present invention, in the fluorescent lamp according to the third aspect, the protective film is a metal oxide and includes at least one element of aluminum, silicon, yttrium, cerium, and titanium as an element. Have.
[0023]
By using a small amount of inexpensive and easily available metal oxides, the luminous flux maintenance factor of fluorescent lamps can be improved more effectively by preventing mercury adsorption, suppressing sodium diffusion, and preventing UV degradation of glass. It is something that can be done.
[0024]
According to a fifth aspect of the present invention, in the fluorescent lamp according to any one of the first to fourth aspects, the inner diameter of the glass tube is 15.0 mm or less.
[0025]
As a result, the luminous flux maintenance factor of a fluorescent lamp using a thin tube, which has been impossible to improve the luminous flux maintenance factor, can be significantly improved.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
The fluorescent lamp according to the present invention has Na as a glass composition.₂O addition amount is 4% or more and 11% or less by weight. Na₂When the addition amount of O exceeds 11% by weight, the workability is good, but the luminous flux maintenance factor of the arc tube is markedly lowered. If the weight ratio is less than 4%, the processing temperature of the glass is high, and the viscosity is higher than that of soda lime glass that has been conventionally used.
[0027]
K₂O, Li₂O is Na₂Along with O, it has the effect of lowering the processing temperature by reducing the viscosity of the glass. In addition, because of the effect of preventing the elution of sodium ions to the surface by the alkali mixing effect, K₂O, Li₂O for Na₂It can be mixed with O to make the glass workability comparable to that of soda-lime glass used in the past. However, K₂O, Li₂Increasing O is not preferable because the water resistance and strength of the glass are lowered.
[0028]
K₂O is preferably added in a weight ratio of 2% or more and 11% or less, and if it is less than 2%, an alkali mixing effect cannot be obtained, and if it exceeds 11%, devitrification occurs.
[0029]
In the present invention, Li₂By adding O at a weight ratio of 4% or less, the linear expansion coefficient of the glass can be adjusted. However, if it exceeds 4%, the expansion coefficient becomes too high, making it unsuitable as a glass for a tube.
[0030]
Furthermore, BaO and SrO are added in order to maintain physical properties similar to soda lime glass. BaO and SrO are relatively large divalent ions in glass and have an effect of preventing the diffusion of sodium ions. However, when added in a large amount, both cause crystallization and easily devitrify. Suitable addition amounts are up to about 10% by weight.
[0031]
B₂O_Three, P₂O_FiveThe addition of can prevent devitrification of the glass due to the presence of BaO and SrO. B₂O_Three, P₂O_FiveIs a material constituting the glass network structure, and by adding a small amount, the glass strength can be increased and the processing temperature can be reduced. Moreover, since water resistance can be improved, there exists an effect which the durability with respect to use of the fluorescent lamp which uses this glass tube improves. Therefore, the movement of sodium ions is prevented by the effect of strengthening the glass structure.
[0032]
As mentioned above, BaO and SrO are B₂O_Three, P₂O_FiveIn addition, it is effective to add to the glass composition. But B₂O_Three, P₂O_FiveHas a property of phase separation when the addition amount is increased, so it is necessary to avoid using a large amount. BaO is more than 0% by weight and less than 6%, SrO is more than 2% by weight and less than 10%, B against it₂O_ThreeIs 0.5% to 3% by weight, P₂O_FiveIs preferably added in a range of 3% or less by weight. In particular, the combined weight ratio of BaO and SrO is preferably 11% or less, and the weight ratio of BaO and SrO is₂O_Three, P₂O_FiveIs preferably added to be 1/2 or less.
[0033]
By adding CaO and MgO, processability as tube glass and appropriate strength are imparted. Moreover, in order to prevent the devitrification of a glass, and since it is cheap, it is preferable to add instead of another metal. The weight ratio of CaO is 6% or less, and the weight ratio of MgO is 6% or less. If CaO and MgO are added in excess of 6% by weight, the effect of suppressing devitrification disappears.
[0034]
Sb₂O_Three, Fe₂O_ThreeWhen a small amount of is added, the transmittance of the glass increases due to the defoaming action, so that the luminous flux of the fluorescent lamp can be improved. It should be noted that this also contributes to an improvement in the luminous flux maintenance factor. In particular, it has been found that a fluorescent lamp having a bent arc tube represented by a bulb-type fluorescent lamp is highly effective. These materials improve the luminous flux maintenance factor depending on the addition amount, but it is preferable that the glass is not colored. Therefore, Sb₂O_ThreeIs more than 0% by weight and 1.5% or less, Fe₂O_ThreeIs preferably added in a range of 0.5% or less by weight. Sb₂O_ThreeIs 1.5% by weight, Fe₂O_ThreeHowever, if the weight ratio exceeds 0.5%, the luminous flux of the lamp is reduced.
[0035]
Also, as a clarifier, SO_ThreeBy adding Sb₂O_Three, Fe₂O_ThreeIt is preferable in order to prevent coloring due to. In addition, SO_ThreeIs preferably added at a weight ratio of 0.5% or less.
[0036]
ZnO, TiO₂, CeO₂And the like are preferable because they increase the visible light transmittance of the glass and prevent ultraviolet degradation.
[0037]
SiO₂Is an important substance as a glass constituent, but when the weight ratio is 50% or less, devitrification due to recrystallization of each additive metal and an extreme decrease in glass strength are caused. Therefore, it is necessary to add more than 50% by weight, and in the present invention, the range of 57% to 78% by weight is most suitable.
[0038]
Al₂O_ThreeHas the effect of preventing devitrification of the glass and increasing water resistance. Therefore, it is preferable to add a weight ratio of 1% or more and 6% or less. If it is less than 1%, devitrification prevention and water resistance cannot be added, and if it exceeds 6%, the glass formation temperature and the glass processing temperature increase. Therefore, it is not preferable.
[0039]
Thus, by using the above glass composition, it is possible to reduce the bond between mercury and sodium ions in the arc tube, and in particular, the luminous flux maintenance rate of compact fluorescent lamps and bulb-type fluorescent lamps is greatly improved. it can.
[0040]
Further, a protective film is preferably provided between the inner surface of the glass tube and the phosphor layer, and is preferably used in combination with the glass tube having the composition of the present invention. The effect of the protective film is to improve the luminous flux maintenance factor by reducing the adhesion of mercury to the glass surface of the inner wall of the arc tube. A specific material is preferably a metal oxide layer containing at least one element of aluminum, silicon, yttrium, cerium, and titanium.
[0041]
In order to prevent the movement of sodium ions into the arc tube, it is important to block the sodium movement path. Sufficient effects were confirmed using a protective film material having a primary particle diameter of 0.01 to 0.1 μm. If such a protective film material is used, the effect of improving the luminous flux maintenance factor of a compact fluorescent lamp, a bulb-type fluorescent lamp, etc. is exhibited even with a thin film of 1 μm or less. Unlike the prior art, forming as a thin film does not greatly change the glass workability at the time of lamp production, and hardly causes appearance problems due to film peeling.
[0042]
The most common material for the protective film is a method in which an organic metal solution, a sol liquid, or a fine powder dispersion containing the above elements is applied by dipping. Since a protective film is formed through firing, the starting material may not be an oxide, and a more uniform protective film can be formed by combining various organic material dispersants and binders.
[0043]
FIG. 1 measures the tube wall load of a fluorescent lamp and compares the luminous flux maintenance factor after a 2500-hour lighting life test. The luminous flux maintenance factor is a luminous flux maintenance factor after lighting for 2500 hours with a luminous flux of 100 hours as 100%. In the figure, symbol ◯ indicates the result of the fluorescent lamp according to the present invention, and symbol x indicates the result of the conventional fluorescent lamp.
[0044]
As is apparent from the measurement results shown in FIG. 1, the tube wall load is 0.13 W / cm.²The conventional fluorescent lamp described above has a luminous flux maintenance factor of 80% or less, whereas the fluorescent lamp according to the present invention has a tube wall load of 0.13 W / cm.²Even if it is above, the luminous flux maintenance factor can be maintained at 80% or more, and the fluorescent lamp of the present invention improves the luminous flux maintenance factor of about 10% or more when lit for 2500 hours as compared with the conventional fluorescent lamp. I was able to.
[0045]
As this fluorescent lamp with a high tube wall load, for example, as shown in FIG. 2, one end portions of two straight tubular glass tubes are connected and integrated by bridge joining, and both ends of the integrated glass tube are integrated. An electrode is provided on the inner part, a phosphor layer is formed on the inner surface of the integrated glass tube, and mercury and a rare gas are enclosed inside to form an arc tube. There is a structure (FPL) in which a base is fixed to the part.
[0046]
In addition to this, tube tubes such as compact fluorescent lamps such as FDL and FHT, bulb-type fluorescent lamps in which arc tubes such as EFT and EFG are housed in glass or resin globes, fluorescent lamps such as FHF, etc. The same effect can be obtained by using it as a glass tube of a fluorescent lamp with a high load. Examples of the lighting device include a ceiling light, a downlight, a high-frequency lighting system using an inverter, or a combination thereof. The present invention is effective with such fluorescent lamps and lighting fixtures.
[0047]
Examples of the present invention will be described below.
[0048]
Example 1
Various glass compositions were examined, and glass composed of various glass compositions was prepared and evaluated. FIG. 3 shows the composition and characteristics of various glass composition glass tubes evaluated. Moreover, all the compositions in the figure are described in weight percentages. The linear expansion coefficient of each glass composition is a linear expansion coefficient at a temperature of about 25 to 300 ° C. The softening temperature of each glass is such that the viscosity of the glass itself upon heating is 107.6 dPa.s. This is the temperature when s is reached. The working temperature is that when heated, the viscosity of the glass itself is 104 dPa.s. This is the temperature when s is reached. The transmittance of each glass was determined by measuring the transmittance of the glass tube with a transmittance spectrometer and calculating the transmittance per millimeter thickness. The measurement of the alkali elution amount of each glass was based on JIS R3502.
[0049]
The glass composition related to the fluorescent lamp of the present invention (in the table, the composition indicated by the present invention product 1 (hereinafter referred to as the present invention product 1)) and the glass composition related to the fluorescent lamp of the present invention (in the table, the present invention product 2) The glass tube which consists of the composition of the composition shown (henceforth this invention product 2) and the composition of the comparative product 1 shown as a comparative example and the comparative product 2 was created. That is, various raw material ratios were added as shown in the table, and after melting, a glass tube was produced through a sleeve.
[0050]
These compositions were easy to mold as a glass tube and could be processed into a fluorescent lamp arc tube without problems. The reason for this is that the addition of strontium, barium, and boron has the effect of lowering the glass melting temperature due to the small amount of sodium. Compositions that did not become glass or that did not achieve the desired characteristics are shown in Comparative Product 3 and Comparative Product 4 in FIG.
[0051]
With respect to an example of soda lime glass and lead glass, which are conventional glass compositions, the glass composition and physical properties are described in Conventional Product 1 and Conventional Product 2 shown in FIG.
[0052]
These glass compositions show almost satisfactory physical properties. However, in the present invention, it is necessary to satisfy the luminous flux maintenance factor as the performance of the fluorescent lamp. The results of evaluating how the characteristics change when a lamp is formed using the glass of the present invention product 1, the present invention product 2, the comparison product 1, the comparison product 2, the conventional product 1 and the conventional product 2 are shown below. This is shown in the examples.
[0053]
(Example 2)
As a high-load fluorescent lamp, an FHT32W type arc tube was manufactured with the glass of the composition of the present invention product 1, comparative product 1, comparative product 2, conventional product 1 and conventional product 2 shown in FIG. 3, and the lamp characteristics were compared.
[0054]
First, glass of various compositions was processed into a bulb having an outer diameter of 12.5 mm and a wall thickness of 1.0 mm, and cut into a total length of 230 mm as a straight glass tube. After the glass tube was washed with water, a protective film was applied to the inner surface of the glass tube as necessary, and a phosphor suspension was applied onto the protective film and dried. This valve is baked in a sinter, and one valve is burned out into two at the center. These two valves are closed at the same time as one of the burned out burners, and the other is an exhaust tube Alternatively, a mount having an electrode was sealed.
[0055]
The three bulbs were thus processed into four exhaust tubules and two mount-sealed ones, and a single arc tube was formed by mutual bridge processing. There are 5 bridges in total. Finally, only one exhaust thin tube was used, and after heating and evacuating with an exhaust device, mercury and a small amount of rare gas were sealed, and the exhaust thin tube was closed to produce an arc tube. A base was attached and finished so that it could be attached to the lighting device.
[0056]
In this arc tube processing, the product 1, the comparative product 1 and the conventional product 1 were not particularly problematic, but when the glass having the composition of the comparative product 2 was used, the arc tube leaked, and several days During this period, about 70% became non-lighting lamps.
[0057]
As a result of analysis, after one valve was burned into two, a mechanical shock was applied during transfer, cracks at the tip portion grew at the final stage, and appeared as a slow leak after exhaust. In particular, when the strength of the arc tube end is compared by performing an iron ball drop test, the comparative product 2 is extremely lower than the glass of other compositions, and is ½ the strength of the product 1 of the present invention. there were. From this, it is considered that the comparative product 2 has low glass strength.
[0058]
Next, the fluorescent lamp produced using the product 1 of the present invention, the comparative product 1 and the conventional product 1 was lit at 32W. The tube wall load is the same, 0.17 W / cm²It is. During lighting, the tube wall temperature of the fluorescent lamp was high and exceeded 130 ° C. at the bridge portion.
[0059]
When the characteristics of each lamp were measured, the initial luminous flux value of the comparative product 1 was reduced by about 5% as compared with the product 1 of the present invention and the conventional product 1 with the same power consumption. This is considered to be due to the amount of barium added, and there is a possibility that excessive barium deteriorates the initial lamp characteristics.
[0060]
In the life test, the life and luminous flux were measured in a cycle of lighting for 2.5 hours per day and 0.5 hours for light extinction, and changes over time were investigated.
[0061]
In FIG. 4, the luminous flux maintenance factor of this invention product 1 and the conventional product 1 is shown. In comparison, the product 1 of the present invention has a luminous flux maintenance factor of about 10% higher than that of the conventional product 1. In addition, the product 1 of the present invention having a structure coated with a protective film (indicated by symbol B in FIG. 4) is approximately compared to the product 1 of the present invention in which a protective film is not provided (indicated by symbol A in FIG. 4). 7% luminous flux maintenance factor is improved. The protective film was alumina, and an alumina powder dispersion having an average particle size of 0.1 μm was applied. The average thickness of the protective film was 0.7 μm. In the case of the conventional product 1 (indicated by symbol D in FIG. 4), the effect of improving the luminous flux maintenance factor is low and only a few percent, even though the same protective film is applied.
[0062]
In the conventional product 1 (indicated by symbol C in FIG. 4), a black spot appeared when the lamp was turned on for over 1000 hours and gradually spread with the lighting time. Even if a protective film is provided, black spots appear after about 2000 hours of lighting, so this glass has a fundamentally large amount of sodium deposited, and it is considered impossible to eliminate the black spots. In the glass of the product 1 of the present invention, no black spot was generated even after lighting for 7000 hours regardless of the presence or absence of the protective film.
[0063]
In this way, using the glass material of the present invention, a remarkable improvement in luminous flux maintenance factor is recognized, and by applying a protective film, further effective improvement is possible compared to the case of a single glass. I found out.
[0064]
(Example 3)
Further, the glass of the present invention product 2 shown in FIG.₂O_ThreeAlthough the softening point increased by about 10 ° C., glass processing was possible without changing the glass processing conditions at all as in the case of the product 1 of the present invention. Using this glass tube, an FHT type fluorescent lamp was manufactured, and a lighting test was performed at 32 W with a dedicated inverter. After lighting for 2500 hours, the luminous flux maintenance factor was compared, which was about 12% improvement over the conventional product 1 The effect was recognized. Moreover, this glass was effective in increasing the strength of the fluorescent lamp, and the compressive strength of the bridge joint reached 1.3 times the normal.
[0065]
Example 4
A glass tube having an outer diameter of 12.0 mm, a thickness of 1.0 mm, and a thickness of 256 mm was produced using the product 1 of the present invention, the conventional product 1 and the conventional product 2 shown in FIG. The glass tube was coated with a protective film and a phosphor according to Example 1 and sinter baked, and then heated twice with a burner to bend twice to produce an arc tube having three bent portions. The arc tube was assembled as a bulb-type fluorescent lamp incorporating a transparent glass globe and an electronic circuit. The power consumption is about 14 W and the tube wall load is about 0.14 W / cm.²It is. Similar to Example 1, the luminous flux maintenance factors after 2500 hours of lighting were compared.
[0066]
As a result, the fluorescent lamp made of glass of the product 1 of the present invention was found to have an improvement in the luminous flux maintenance factor of about 12% after being lit for 2500 hours compared to the conventional product 1. In addition, a comparison with the conventional product 2 shows a difference in the luminous flux maintenance factor of about 5%, and a longer effect was obtained over a long period of time. This seems to be because the sodium ion migration is lower than that of the conventional product 2 in the glass compositions of the product 1 of the present invention and the conventional product 2 even though the amount of sodium is almost equal to about 7%. Therefore, even in a light bulb type fluorescent lamp in which a fluorescent tube is covered with a globe, the glass composition of the present invention can effectively improve the luminous flux maintenance factor.
[0067]
(Example 5)
Using the glass of the product 1 of the present invention and the conventional product 1 shown in FIG. 3, a linear luminous tube having a tube outer diameter of 32.5 mm and a length of 580 mm was produced, and a fluorescent lamp having a base attached to both extremes was produced. And it lights at 20W and the tube wall load is 0.04W / cm.²Met. A life lighting test of these two kinds of glass fluorescent lamps was conducted, and the luminous flux maintenance rates of 2500 hours and 7000 hours were compared. As a result, an average of 1.5% was improved in 2500 hours, and about 3% in 7000 hours. Only the improvement effect was recognized. When this fluorescent lamp was turned on and measured in a sealed lighting fixture, the improvement of the luminous flux maintenance factor was only about 3% as compared with the conventional product 1 in about 2500 hours. The maximum temperature of the lamp was in the vicinity of the electrode, and was about 70 ± 5 ° C. at room temperature of 25 ° C.
[0068]
However, when the glass of the product 1 of the present invention and the conventional product 1 are processed into a linear arc tube having a tube inner diameter of 14.5 mm and a length of 360 mm and are lit at a high frequency lighting of about 20 W, a luminous flux maintenance factor of 2500 hours is obtained. The glass of the present invention 1 was about 5% higher. Further, in lighting in a sealed device whose front surface is covered with a light diffusing plastic, the product 1 of the present invention has a higher luminous flux maintenance rate than the conventional 1 by about 10%. In this case, the temperature of the tube wall exceeded 100 ° C. Tube wall load is 0.13 W / cm²Met. From this, even in a fluorescent lamp using a straight tube, it was confirmed that the present invention improves the luminous flux maintenance factor by lighting at a high temperature when the tube wall load is high.
[0069]
【The invention's effect】
As described above, the present invention provides a luminous flux maintenance factor by reducing the amount of sodium ions deposited on the inner wall of the arc tube in a fluorescent lamp with a high tube wall load represented by a compact fluorescent lamp and a bulb-type fluorescent lamp. , And the occurrence of blackening of the arc tube and generation of black spots can be eliminated. The tube wall load is 0.13 W / cm²Compared to the above compact fluorescent lamp and bulb-type fluorescent lamp, it is possible to suppress a decrease in the luminous flux maintenance factor without impairing the workability of the conventional arc tube. Further, by providing the protective film on the inner wall of the arc tube, it is possible to effectively suppress the precipitation of sodium on the inner wall of the arc tube, and to improve the luminous lifetime of the arc tube in combination with the above-described composition glass tube. In addition to fluorescent lamps with high tube wall load, if the wall temperature of at least some of the light-emitting tubes that are lit exceeds 100 ° C, a fluorescent tube such as a bulb-type fluorescent lamp that is housed in an envelope. The lifetime of a compact fluorescent lamp with a bent lamp or arc tube can be significantly improved. In addition, it is possible to provide a fluorescent lamp that can reduce the burden on the environment without using lead at all, and can be made cheaper and lighter.
[Brief description of the drawings]
FIG. 1 is a graph showing the relationship between the tube wall load of a fluorescent lamp and the luminous flux maintenance factor after 2500 hours of lighting.
FIG. 2 is a diagram showing an FPL type fluorescent lamp according to an embodiment of the present invention.
FIG. 3 shows a comparison of various glass compositions and physical properties.
FIG. 4 is a graph showing the change over time of the luminous flux maintenance factor of a compact fluorescent lamp.

Claims (5)

Mercury and a rare gas are sealed in a glass tube having a phosphor layer deposited on the inner surface, the tube wall load is 0.13 W / cm ² or more, and the glass tube is made of SiO 2 by weight. ₂ to 57% to 78%, BaO to more than 0% to 6%, SrO to 2% to 10%, CaO to 0 to 6%, MgO to 0 to 6%, Na ₂ O to 4% more than 11% or less, 2% or more 11% or less K2O, the Li ₂ O 0 or more and 4% or less, the B ₂ O ₃ 0.5% 3% or less, the P ₂ O ₅ 0 to less than 3%, Al ₂ O ₃ is 1% or more and 6% or less, Sb ₂ O ₃ is more than 0% and 1.5% or less, Fe ₂ O ₃ is 0 or more and 0.5% or less, and SO ₃ is 0 or more and 0.5% or less. The combined weight ratio of BaO and SrO is 11% or less, and with respect to the weight ratio of BaO and SrO, B ₂ O ₃ and P ₂ O ₅ are 1 / A fluorescent lamp characterized by being 2 or less .   The fluorescent lamp according to claim 1, wherein the arc tube is housed in a glass or resin globe.   The fluorescent lamp according to claim 1 or 2, wherein a protective film is formed between an inner surface of the glass tube and the phosphor layer.   The fluorescent lamp according to claim 3, wherein the protective film is a metal oxide and contains at least one element of aluminum, silicon, yttrium, cerium, and titanium as an element.   The fluorescent lamp according to any one of claims 1 to 4, wherein an inner diameter of the glass tube is 15.0 mm or less.

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