JPH11176379A - Fluorescent lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress consumption of mercury by equipping with a glass bulb having a specific metal oxide as essential components, a phosphor layer on an inner bulb surface, noble gas and mercury to fill and a discharge maintenance means. SOLUTION: Essential components to form a glass bulb are SiO2 , alkali components and at least one components of SrO and BaO. It contains SiO2 for 62-78 wt.% as a skeletal component and Na2 O in particular for 9-18 wt.% as a modifying oxide selected from alkali components of Na2 O, K2 O and Li2 O. SrO and BaO are added to substitute NaO2 component and their substitution quantity is 4-10 wt.% and 0.5-6 wt.% respectively. SrO and BaO prevent alkali components from being diffused onto a bulb surface, and shows an effect to reduce consumption of mercury by amalgamation during lighting for a long time. In addition, the glass bulb 1 should preferably contain Fe2 O3 effective to prevent ultraviolet ray from leaking outside for 0.3-1.0 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent lamp, and more particularly, to a fluorescent lamp in which the consumption of mercury sealed in a glass bulb is suppressed.

[0002]

2. Description of the Related Art Conventionally, as a fluorescent lamp of this type, a soda-lime quartz glass (soda-lime silica glass) bulb and a bulb formed on the inner surface of the bulb in order to prevent the consumption of mercury and the decrease in luminous flux on the glass surface are known. Protective film consisting of metal oxide fine particles or a continuous metal oxide film, a rare earth element-based or calcium halophosphate-based phosphor layer formed on the inner surface side of the protective film, and mercury sealed in a bulb. And a rare gas such as argon and an electrode such as a hot cathode (see, for example,
No. 30788).

[0003]

However, in the conventional fluorescent lamp, since the diameter of the fine particles of the metal oxide in the protective film is as large as 300 times or more the atomic diameter of mercury, the metal oxide diffuses from the glass during long-time operation. There has been a problem that sodium and mercury react to form amalgam and mercury that contributes to light emission is consumed.

Further, in the conventional fluorescent lamp, since the linear expansion coefficient of the protective film is different from that of the glass bulb, there is a problem that the glass bulb shrinks or the protective film is cracked in a manufacturing process.

[0005] The present invention has been made in view of such circumstances, and by improving the composition of a glass bulb,
An object is to provide a fluorescent lamp with reduced mercury consumption.

[0006]

In order to achieve the above object, the fluorescent lamp of the present invention comprises SiO ₂ , an alkali component,
A glass bulb containing at least one selected from SrO and BaO as an essential component, a phosphor layer formed on the discharge space side of the glass bulb, a rare gas and mercury sealed in the glass bulb, Discharge maintaining means for maintaining a discharge in the discharge space.

As described above, by adding at least one component selected from SrO and BaO, the diffusion of the alkali component in the glass bulb to the surface of the glass bulb is suppressed, and the consumption of mercury during lighting of the fluorescent lamp is reduced. be able to.

In the above-mentioned fluorescent lamp, the alkali elution amount of the glass bulb is preferably 25% or less of the alkali elution amount when all of SrO and BaO contained in the glass bulb are replaced with alkali components. . Here, the alkali elution amount is determined according to JIS R3
It is a quantity measured and determined based on 502.

Further, in the above fluorescent lamp, the glass bulb may contain 4 to 10% by weight of SrO and 0.5% by weight.
It is preferable to contain at least one selected from BaO of up to 6% by weight. SrO or BaO suppresses the diffusion of the alkali component, but if contained excessively, the glass may partially crystallize and become cloudy, so the above range is preferable. Further preferred ranges are 4 to 8% for SrO and 0.5 to 5% for BaO, also expressed by weight%. Note that SrO and BaO may include only one or both of them.

In the above-mentioned fluorescent lamp, the glass bulb preferably contains 0.3 to 1.0% by weight of Fe ₂ O ₃ . According to this preferred example, it is possible to suppress ultraviolet rays generated from mercury from leaking to the outside of the fluorescent lamp.

Preferably, the fluorescent lamp includes a film made of a metal oxide between the glass bulb and the phosphor layer. According to this preferred example, since the contact between mercury and the glass bulb can be reduced, the consumption of mercury can be further suppressed. In this case, as the metal oxide, Al ₂ O ₃ , Y ₂ O ₃
And at least one metal oxide selected from SiO ₂ and SiO ₂ .

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the fluorescent lamp of the present invention will be described below with reference to the drawings. FIG. 1A is a diagram showing a longitudinal section (tube longitudinal section) of a straight tube fluorescent lamp according to an embodiment of the present invention. Flare stems 2 are hermetically sealed to both ends of the glass bulb 1, and a pair of lead wires 3 is passed through each of them in an airtight manner. Between these lead wires 3 at both ends, a filament electrode 4 coated with an electron-emitting substance is laid. In addition, bases 5 are fixed to both ends of the glass bulb 1, and base pins 6 electrically connected to the lead wires 3 are fixed to these bases 5.

On the other hand, FIG. 1B is a view showing a cross section (transverse tube cross section) of the straight tube type fluorescent lamp in the short direction. On the inner surface of the glass bulb 1, a phosphor layer 7 of a rare earth phosphor is formed. The phosphor layer 7 is, for example, three types of rare earth phosphors that emit light at red, green, and blue wavelengths, for example, a yttrium-based red phosphor, a lanthanum-based green phosphor, and a strontium-based blue phosphor. Are used, and these three types of phosphor powders are mixed. The glass bulb 1 is filled with a predetermined amount of mercury and a rare gas such as argon.

Hereinafter, the glass components constituting the glass bulb 1 will be described.

The glass components constituting the glass bulb 1 are as follows:
At least SiO ₂ is contained as a glass skeleton component, and N 2
alkaline components such as a ₂ O, K ₂ O and Li ₂ O (particularly Na ₂
O) as a modifying oxide, and at least one of SrO and BaO as an alkali component diffusion suppressing component. The glass component is, for example, CaO, Mg
It contains O and Al ₂ O ₃ as optional components.

Table 1 shows examples of such glass components. (Table 1) SiO _2: 62~78% by weight: eg 72.3 wt% Na ₂ O: 9 to 18 wt%: 16.4 wt% CaO: 1 to 9 wt%: 8.7 wt% MgO: 1 4%: 1.5 wt% Al ₂ O _3: 0.5 to 5% by weight: at 1.1 wt% this embodiment, in addition to the components shown in Table 1, further of SrO and BaO At least one component is added in a manner that replaces the Na ₂ O component of the above components. The substitution amount is, for example, 4-1 for SrO.
0% by weight and about 0.5 to 6% by weight for BaO.

Furthermore, harmful ultraviolet rays can be absorbed by incorporating a transition metal oxide, Fe ₂ O _3, into the glass bulb. When the content is 0.3% by weight or more, a preferable ultraviolet absorptivity can be obtained. When the content is 1.0% by weight or less, an excessive increase in absorption of visible light can be suppressed to maintain the luminous efficiency of the lamp. it can.

The compounds constituting the glass component are not limited to the above examples, and B ₂ O ₃ , P ₂ and P ₂ may be used in order to improve the stability and workability of the glass in a fluorescent lamp.
It may contain other compounds such as O ₅ and Sb ₂ O ₃ , and may further contain a trace amount of impurities mixed in the manufacturing process.

In the above fluorescent lamp, as a discharge maintaining means for initiating and maintaining the discharge in the discharge space, the filament electrode 4 coated with the electron-emitting substance (and connected thereto) is directly used as a discharge maintaining means. However, the discharge maintaining means does not necessarily need to be installed inside the discharge space, and a device capable of applying energy required for discharge from outside the bulb 1 serving as the discharge space may be used. I do not care. Examples of such a device include a device using electromagnetic induction and a device using microwaves.

In the above-described fluorescent lamp, a rare earth phosphor is used as a phosphor, but another phosphor such as a calcium halophosphate phosphor may be used.

FIG. 2 is a view showing a tube cross section of a straight tube type fluorescent lamp according to another embodiment of the present invention. This fluorescent lamp has aluminum oxide Al _{2 on} the inner surface of the glass bulb 1.
It differs from the fluorescent lamp shown in FIG. 1 in that a particulate metal oxide film 21 made of O ₃ is formed. The protective film made of the fine metal oxide film 21 has an effect of reducing contact between mercury and the glass bulb.
The protective film is provided to reduce contact between mercury and the glass bulb, and is not limited to metal oxide fine particles. For example, a similar effect can be obtained even with a continuous metal oxide protective film formed of an organic metal or the like.

[0022]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. Hereinafter, all percentages indicating the content ratio of each component are expressed by weight%.

In order to suppress the consumption of mercury in the fluorescent lamp, a soda-lime quartz glass obtained by replacing a certain amount of Na ₂ O with SrO was used. The amount of Na ₂ O eluted from the soda lime quartz glass when Na ₂ O in the glass was replaced with SrO was measured based on the alkali elution test (R3502) of JIS. This result is shown in FIG.
Shown in The conventional soda-lime quartz glass component used is the component exemplified in the right column of Table 1.

As shown in FIG. 3, N 2 from conventional soda-lime quartz glass, ie, glass containing no SrO, is used.
The elution amount of a ₂ O was 0.40 mg. When a part of the amount of Na ₂ O in the conventional soda-lime quartz glass is replaced with SrO, the Na ₂ O elution amount sharply decreases in a region where the SrO content is 3% to 4%, and SrO Is 4% or more, the elution amount of Na ₂ O is 25% or less as compared with the case where SrO is not contained. Therefore, a glass that is particularly effective in mercury consumption when used in a fluorescent lamp has an SrO content of 4% or more. In addition, as the content of SrO increases, the elution amount of Na ₂ O decreases. However, when the content of SrO exceeds 10%, crystallization occurs inside the glass, the transmittance decreases, and white turbidity may occur. Occurs. Further, by setting the content of SrO to 8% or less, processing of the glass becomes easy.

BaO can also suppress the diffusion of Na ₂ O. In the case of BaO, since the effect of suppressing alkali diffusion is better than that of SrO, the content in glass can be smaller than that of SrO. When the content of BaO is 0.5% or more, a preferable alkali diffusion suppressing effect can be obtained. Further, in order to suppress crystallization of glass, the content of BaO is set to 6%.
% Is preferable. Further, when the content of BaO is set to 5% or less, processing of the glass becomes easy.

In order to improve the effect of suppressing alkali diffusion, both oxides of SrO and BaO can be contained in the glass.

Next, the mercury consumption of the fluorescent lamp was experimentally confirmed. FIG. 4 is a characteristic diagram obtained by examining the mercury consumption of the present invention, in which the vertical axis indicates the mercury consumption [mg] and the horizontal axis indicates the lighting time [hour]. The characteristic a is that aluminum oxide Al ₂ O _{3 is} added to the above-mentioned conventional soda-lime quartz glass bulb.
This is a result of a fluorescent lamp (hereinafter, referred to as “fluorescent lamp A”) in which a protective film made of metal oxide fine particles is provided between a glass bulb and three kinds of rare earth phosphor layers.
Characteristic b is (without a protective film) has the same structure as shown in FIG. 1, replacing 5.0% of the of Na ₂ O in the composition shown in Table 1 the right column with SrO (Na ₂ O: 11.4%, S
This is a result of a fluorescent lamp using a glass bulb (rO: 5.0%) (hereinafter, referred to as “fluorescent lamp B”). The characteristic c has a structure similar to that shown in FIG. 2 (with a protective film: a protective film made of fine particles of aluminum oxide Al ₂ O ₃ is provided between the glass bulb and the three kinds of rare earth phosphor layers. ), A fluorescent lamp using a glass bulb having the same composition as the fluorescent lamp B (hereinafter, “fluorescent lamp C”)
It is a result about.

As shown in FIG. 4, since the fluorescent lamp B is a fluorescent lamp using a glass bulb having an effect of suppressing sodium diffusion, consumption of mercury due to amalgam formation of sodium and mercury occurring on the glass surface for a long time is suppressed. Have been. In the fluorescent lamp C, the consumption of mercury is suppressed similarly to the fluorescent lamp B, and in addition, since the aluminum oxide protective film is formed between the glass bulb and the phosphor layer, the mercury contacts the glass. The probability has decreased and the consumption of mercury due to the amalgam formation of sodium and mercury has been further suppressed. On the other hand, the fluorescent lamp A is obtained by forming a protective film of aluminum oxide on the conventional soda-lime quartz glass, but has a sufficient effect of suppressing mercury consumption compared to the fluorescent lamps B and C in long-term lighting. Not obtained.

Subsequently, the luminous flux maintenance factor was experimentally confirmed. FIG. 5 is a characteristic diagram obtained by examining a luminous flux maintenance factor in the fluorescent lamp of the present invention. The vertical axis indicates the total luminous flux [lm], and the horizontal axis indicates the lighting time [hour]. The characteristic d is the result for the fluorescent lamp C, the characteristic e is the result for the fluorescent lamp B, and the characteristic f is the result for the fluorescent lamp A.

As shown in FIG. 5, in the fluorescent lamp C, the protective film of aluminum oxide is formed between the glass bulb and the phosphor layer, and the ultraviolet light passing through the phosphor layer is applied to the protective film of aluminum oxide. Is reflected by the fluorescent lamp A
And the initial total luminous flux is improved by about 3% as compared with the fluorescent lamp B. Furthermore, since a glass bulb having an effect of suppressing sodium diffusion is used, the generation of amalgam due to the reaction between mercury and sodium is reduced, and the luminous flux maintenance ratio (96.3%) of the fluorescent lamp C is lower than that of the fluorescent lamp A. It is higher than the luminous flux maintenance rate (94.9%). Fluorescent lamp B
(96.5%) is better than the luminous flux maintenance factor of the fluorescent lamp A despite the absence of the aluminum oxide protective film. That is, fluorescent lamps without a protective film on the glass bulb that has the effect of suppressing sodium diffusion,
This shows that the consumption of mercury is suppressed as compared with the conventional fluorescent lamp in which a protective film such as aluminum oxide is provided on soda-lime quartz glass. Here, the luminous flux maintenance ratio is a ratio of the total luminous flux to the initial total luminous flux in a certain lighting time, and the above-mentioned numerical value is a value in the lighting time of 4000 hours.

Subsequently, a fluorescent lamp C was manufactured using a protective film composed of fine particles of silicon oxide SiO ₂ and yttrium oxide Y ₂ O ₃ in addition to aluminum oxide Al ₂ O ₃ .

The mercury consumption of the fluorescent lamps having these various protective films was experimentally confirmed. FIG. 6 is a characteristic diagram showing the results, in which the vertical axis indicates mercury consumption [mg] and the horizontal axis indicates lighting time [hour]. Characteristic g is silicon oxide SiO
₂ is a result of a fluorescent lamp in which a protective film made of metal oxide fine particles is provided between a glass bulb and three kinds of rare earth phosphor layers, and the characteristic h is aluminum oxide Al _2.
The results are for a fluorescent lamp in which a protective film made of fine particles of O ₃ metal oxide is provided between a glass bulb and three kinds of rare earth phosphor layers, and the characteristic i is yttrium oxide Y ₂ O ₃
3 shows the results of a fluorescent lamp in which a protective film made of metal oxide fine particles was provided between a glass bulb and three kinds of rare earth phosphor layers.

As shown in FIG. 6, the effect of suppressing the consumption of mercury in the fluorescent lamp is best when yttrium oxide is used as the protective film and aluminum oxide and silicon oxide are almost the same. Mercury consumption was able to be suppressed more than a fluorescent lamp using lime quartz glass.

[0034]

As described above, according to the present invention,
SiO ₂ , alkali components, and SrO and BaO
A glass bulb containing at least one selected from the following as an essential component, a phosphor layer formed on the discharge space side of the glass bulb, a rare gas and mercury sealed in the glass bulb, and discharge in the discharge space. By using a fluorescent lamp provided with a discharge maintaining means for maintaining the above condition, it is possible to provide a fluorescent lamp which consumes less mercury, that is, reduces the amount of enclosed mercury and is environmentally friendly.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a fluorescent lamp according to the present invention by a vertical cross section (FIG. 1A) and a horizontal cross section view (FIG. 1B).

FIG. 2 is a diagram showing another embodiment of the fluorescent lamp of the present invention by a cross-sectional view thereof.

3 is a characteristic diagram showing the Na ₂ O elution amount when the Na ₂ O in the soda-lime-silica glass was replaced with SrO.

FIG. 4 is a characteristic diagram showing the mercury consumption of a straight tube fluorescent lamp depending on the type of glass bulb.

FIG. 5 is a characteristic diagram showing a luminous flux maintenance factor of a straight tube fluorescent lamp depending on a difference in a glass bulb.

FIG. 6 is a characteristic diagram showing mercury consumption of a straight tube fluorescent lamp depending on the material of a protective film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass bulb 4 Filament electrode 7 Phosphor layer 21 Fine metal oxide coating

Claims (6)

[Claims] 1. The method according to claim 1, wherein the SiO ₂ , the alkali component, and Sr
A glass bulb containing at least one selected from O and BaO as an essential component, a phosphor layer formed on the discharge space side of the glass bulb, a rare gas and mercury sealed in the glass bulb, A fluorescent lamp, comprising: discharge maintaining means for maintaining a discharge in a discharge space. 2. The alkali elution amount of the glass bulb is as follows:
25% of the alkali elution amount when all SrO and BaO contained in this glass bulb were replaced with alkali components.
%. 3. The fluorescent lamp according to claim 1, wherein the glass bulb contains at least one selected from 4 to 10% by weight of SrO and 0.5 to 6% by weight of BaO. 4. The fluorescent lamp according to claim 1, wherein the glass bulb contains 0.3 to 1.0% by weight of Fe ₂ O ₃ . 5. The fluorescent lamp according to claim 1, further comprising a metal oxide film between the glass bulb and the phosphor layer. 6. The fluorescent lamp according to claim 5, wherein the metal oxide is at least one selected from Al ₂ O ₃ , Y ₂ O ₃ and SiO ₂ .