JPH03194846A - Amalgam and low pressure mercury vapor discharge lamp with the amalgam sealed - Google Patents

Abstract

PURPOSE:To obtain a lamp suitable for an intermediate bulb wall temperature by using amalgam obtained with mercury of specific wt.% of whole amalgam contained in specific base metal. CONSTITUTION:Amalgams 5, 6 for a low pressure mercury vapor discharge lamp are used wherein the amalgam is obtained by allowing mercury to be contained by 1 to 12wt.% of whole amalgam in base metal composed of 50 to 65wt.% of bismuth and 35 to 50wt.% of tin. This amalgam is with little natural oxidation during a manufacturing process, and it exhibits mercury vapor pressure suitable for discharging over a wide temperature range so that it can be used for a low pressure mercury vapor discharge lamp to be used in various bulb shapes over a wide environmental temperature range. Thus a low pressure mercury vapor discharge lamp exhibiting optimum mercury vapor pressure even in an intermediate bulb wall temperature can be obtained.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention aims to maintain a mercury vapor pressure suitable for discharge over a wide temperature range in an amalgam sealed in a low-pressure mercury vapor discharge lamp, and to maintain a mercury vapor pressure suitable for discharge over a wide temperature range. Suitable for discharge lamp structures or usage methods that exhibit a bulb bottom temperature of approximately

(Prior Art) A low-pressure mercury vapor discharge lamp, such as a fluorescent lamp, is filled with pure mercury, and when the tube wall temperature during operation is 40°C, the mercury vapor pressure inside the tube is 6. It exhibits OX 10-''Torr, and it is said that the lamp exhibits the best characteristics when the mercury vapor pressure is around this value.

In recent years, a compact fluorescent lamp, called a compact fluorescent lamp, has been developed in which a compact fluorescent lamp with a bent bulb is housed together with a ballast in a small, sealed globe. In such compact fluorescent lamps, the heat generated from both the lamp and the ballast is trapped within the small globe, so the temperature of the tube wall reaches over 90 degrees Celsius during operation, and in this case, the temperature inside the tube increases. An excessive increase in mercury vapor pressure will reduce the light output of the lamp. Therefore, in conventional compact fluorescent lamps, amalgams such as bismuth (Bi), indium (
During operation, the mercury vapor pressure inside the tube was appropriately controlled by sealing an amalgam such as In) in the valve.

However, in recent years, fluorescent lamps having curved discharge paths, such as U-shaped fluorescent lamps and H-shaped fluorescent lamps, have come into widespread use, and there has been a demand for improved lamp characteristics. That is, in such a fluorescent lamp, due to its structure, the tube wall temperature is slightly lower than that of the above-mentioned conventional compact fluorescent lamp, which is 90° C. or higher.

Compared to the naked lighting of ordinary straight tube fluorescent lamps, the tube wall temperature is much higher, so to speak, at a medium level.

In this case, if the above-mentioned bismuth or indium amalgam is sealed in the bulb, the mercury vapor pressure will be too low and the lamp output will not be sufficient. If you replace the amalgam with mercury instead, the mercury vapor pressure will be too high and the lamp output will not be sufficient.

Furthermore, when a straight tube fluorescent lamp is operated naked in a high-temperature atmosphere, the tube wall temperature remains at the medium level described above, and similarly, if bismuth or indium amalgam is sealed inside the bulb, the mercury vapor pressure will be reduced. It is too low, and if mercury is enclosed, the mercury vapor pressure will be too high.

(Problems to be Solved by the Invention) Regarding the problem of mercury vapor pressure related to the above-mentioned medium tube wall temperature, for example, as proposed in Japanese Patent Application No. 63-021366, bismuth-lead (Bi-Pb) based amalgam has been proposed. By enclosing it in a low-pressure mercury vapor discharge lamp, it exhibits a mercury vapor pressure intermediate between pure mercury and the above-mentioned bismuth-indium amalgam, and good lamp output can be obtained even at moderate tube wall temperatures.

However, the surface of the above-mentioned bismuth-lead amalgam tends to blacken and oxidize during handling, and for this reason, low-pressure mercury vapor discharge lamps filled with bismuth-lead amalgam tend to have unstable discharge. It has the disadvantage of being easily blackened.

Therefore, the object of the present invention is to provide a low-pressure mercury vapor discharge lamp that exhibits appropriate mercury vapor pressure even at moderate tube wall temperatures.
Moreover, it is an object of the present invention to provide an amalgam that is free from natural oxidation, and a low-pressure mercury vapor discharge lamp containing this amalgam.

[Structure of the invention]

(Means for Solving the Problem) The present invention is mainly directed to a low-pressure mercury vapor discharge lamp that operates at a medium tube wall temperature.
An amalgam for low-pressure mercury vapor discharge lamps, which is made of a base metal consisting of 5% by weight and 35% to 50% by weight of tin, and 1 to 12% by weight of the entire amalgam. It exhibits suitable mercury vapor pressure within the range. The second claim is a low-pressure mercury vapor discharge lamp filled with the amalgam described in the first claim, which can be applied to lamps of various shapes, and can be applied to a wide temperature range even with the same shape. Furthermore, the third claim forms a continuous discharge path having both ends in the same direction and at least one folded part in the opposite direction to the both ends, so that the coldest part of the bulb is always aligned with the line of gravity during lighting. A low-pressure mercury vapor discharge lamp, which has a bulb shape so as to be located on the lower side and is filled with the amalgam described in claim 1, exhibits an appropriate mercury vapor pressure during lighting to obtain high efficiency, and is capable of achieving high efficiency. Brightness fluctuations caused by mercury dripping can be prevented.

(Function) The above-mentioned bismuth/tin-based amalgam (Bi-3n/Hg)
has less natural oxidation during the manufacturing process and has a mercury vapor pressure (6, OX 1) that is suitable for discharge over a wide temperature range.
It can be used in low-pressure mercury vapor discharge lamps used in various bulb shapes and in a wide range of environmental temperatures.

(Example) The present invention will be described in detail below. The amalgam of the present invention has an alloy of bismuth (Bi) and tin (Sn) as a base and contains mercury (Hg). Therefore, mercury is added to a base metal consisting of 57% by weight of bismuth and 43% by weight of tin, with the total weight of the amalgam being 1,0.5.0.
Various amalgams containing 12, 0, and 17.0% by weight were prepared, and the mercury vapor pressure of each amalgam was measured at various temperatures. In addition, for comparison, pure mercury, conventional high-temperature amalgam of bismuth 64.3% by weight, indium 31.7% by weight, mercury 4.0% by weight amalgam, and medium-temperature amalgam bismuth 54.2% by weight, The mercury vapor pressure at various temperatures of an amalgam containing 41.8% by weight of tin and 4.0% by weight of mercury was also measured. The results are shown in FIG.

In the figure, the horizontal axis shows temperature in degrees Celsius, and the vertical axis shows mercury vapor pressure in Torr, and the curve B1-8n Hg
(solid line) is the above-mentioned bismuth-tin amalgam of the present invention, with the amount of mercury subscripted, curve 1 (g (solid line) is pure mercury, curve B1-In HHg (dashed line) is the above-mentioned conventional high temperature amalgam Bismuth-indium amalgam, curve Bi-P
b-Hg (dashed line) is the conventional medium bisma・Hg mentioned above.
The mercury vapor pressure curves of each lead amalgam are shown.

As is clear from this Figure 1, the mercury content is 17% by weight.
Amalgam has a narrow stable temperature range and is not preferred. Furthermore, if the mercury content is 12% or less, the mercury vapor pressure at low temperatures is close to that of pure mercury, and the mercury vapor pressure at high temperatures is much lower than that of pure mercury and close to that of bismuth-indium amalgam for high temperatures. This means that the bismuth-tin amalgam of the present invention is not only optimal for low-pressure mercury vapor discharges with moderate tube wall temperatures, but also can withstand to some extent tube wall temperatures from low to high, and is stable over a wide temperature range. It is shown that this method can be used in low-pressure mercury vapor discharge lamps with various bulb shapes and in a wide range of environments. This is because the stabilization temperature range of the above-mentioned bismuth-lead amalgam, which is a conventional medium-use amalgam, is extremely narrow and can only be used for lamps of specific shapes or lamps used in specific environments. Amalgam is particularly good.

Next, the present inventors investigated the minimum required amount of mercury in the bismuth-tin amalgam of the present invention.

Approximately 150 mg of amalgam was sealed in the lamp, and a life test was conducted. As a result, it was found that all amalgams with a mercury content of 1% by weight or more had no problem in life. Furthermore, when the amount of mercury in the present amalgam was less than 1% by weight, the amount of mercury was too small and was consumed during the life, causing a short life.

Regarding the content of bismuth and tin, it is most desirable to use a eutectic alloy containing 57% by weight of bismuth and 43% by weight of tin from the viewpoint of compositional variation. It was found from the results of the lamp test that there is no practical problem within this range.

In addition, even when the bismuth-tin amalgam of the present invention was stored in a lamp for about one year after manufacture and then sealed in a lamp, no discoloration of the surface was observed in terms of characteristics.

Next, FIG. 2 shows an H-shaped fluorescent lamp, which is an example of a low-pressure mercury vapor discharge lamp filled with the above-mentioned bismuth-tin amalgam of the present invention. In the figure, (1) is an H-shaped valve,
(2) is a discharge path formed in the internal space of this bulb (1), (3) is a fluorescent film formed on the inner surface of the bulb (1),
(4), (4) is a stem that closes both ends of the valve (1), (5) is the main amalgam made of bismuth-tin amalgam of the present invention provided at the end of the valve (1), and (6) is the stem. (4), This is the auxiliary amalgam attached to (4).

The above bulb (1) is two straight glass bulbs (11)
, (11) are arranged in parallel, the tip surfaces (12), (12) of the planned folding portions are closed, and the tip surfaces (12), (12) are arranged in parallel.
12) A communication part (13) is formed between adjacent side surfaces to couple both glass bulbs (11), (11), and the discharge path (2) is communicated in an H-shape to form a folded part (14). It is.

The stem (4) has a pair of lead wires (41), (41)
The filament (42) is inserted between the inner ends of the lead wire, and the main amalgam (5) of the present invention described above is filled in the exhaust pipe (43). An auxiliary amalgam (6) is attached to the area adjacent to the auxiliary amalgam (6).

The above-mentioned folded portion (14) (excluding the fluorescent film) is shown in FIG. In the figure, let Q be the distance between the center line (15) of the communicating portion (13) and the inner wall of the tip surface (12), and let Dl be the inner diameter of the straight portion of the glass bulb (11).

Q≦0.8D□ There is a relationship.

As mentioned above, the main amalgam contains 50 to 50 bismuth.
The amalgam contains mercury in an amount of 1 to 12% by weight of the entire amalgam in a base metal consisting of 65% by weight and 35 to 50% by weight of tin.

Next, the operation of the fluorescent lamp of this embodiment will be explained.

As mentioned above, this fluorescent lamp uses the bismuth-tin amalgam of the present invention as the main amalgam, so even though the temperature at the coldest part of the bulb reaches around 70°C during horizontal lighting, the mercury vapor pressure inside the tube is almost constant. 6, OX 1O-3To
It is maintained around rr, discharges normally, and exhibits high efficiency as specified. Moreover, even if the environmental temperature changes considerably, the mercury vapor pressure inside the tube does not change much, and the production efficiency does not change much. Furthermore, since there is no natural oxidation of the amalgam during the manufacturing process, there is very little variation in lamp characteristics.

In addition, since the fluorescent lamp of this embodiment has the folded portion (14) configured as described above, the natural cooling of the folded portion (14) is appropriately weak, and for example, the folded portion (14) is located below the line of gravity. When the light is turned on in a state where the valve is located in the base-up state, the folded part (14) is not affected by convection in the tube, so there is less heating, and the inner surface of the bulb near the folded part (14) becomes the coldest part. become. In this case, since the main amalgam (5) is located above, the temperature rises due to the influence of convection, but the change in mercury vapor pressure due to temperature changes in the bismuth-tin amalgam of the present invention is small. The cold part becomes the main amalgam (
Since the effect of 5) is complemented, fluctuations in the mercury vapor pressure inside the tube are further reduced. Moreover, in the case of this base-up lighting, the folded part (14), which is the coldest part, is located at the bottom, so even if mercury condenses on the inner surface of the folded part (14), it drips onto the filament (42) and brightens up. There is also an effect that does not change the intensity.

In addition, when the fluorescent lamp of this example is lit with the folded part (14) located above the line of gravity (base-down shape M), the folded part (14) is warmed by convection and is sufficiently cooled by natural cooling. Instead, the coldest part is formed at a part other than the folded part (14), usually at the end of the tube. In this case, the mercury vapor pressure inside the tube is determined by the mercury vapor pressure of the main amalgam (5), and as mentioned above,
Maintained 0-3 orders orr. Moreover, the main amalgam (
5) There is little change in the mercury vapor pressure due to the temperature of the bismuth/tin amalgam that constitutes the tube, and there is little change in the mercury vapor pressure in the tube due to changes in the environmental temperature, so the best efficiency can always be maintained.

In this way, the fluorescent lamp of this embodiment can maintain the mercury vapor pressure inside the tube normally in all cases, whether it is lit horizontally, lit with the base up, or lit with the base down. Furthermore, even if the environmental temperature changes, the mercury vapor pressure inside the tube does not change much, so starting characteristics are good and high efficiency can be maintained.

Next, FIG. 4 shows a U-shaped fluorescent lamp, which is another example of the low-pressure mercury vapor discharge lamp filled with the bismuth-salmon amalgam of the present invention. This device is characterized by the folded portion (14) of the discharge path (2).

Since everything else is the same as the H-shaped fluorescent lamp shown in FIG. 2, only the differences will be explained in detail. That is, valve (1)
1 is a long straight glass bulb (16) whose middle part is bent into a U-shape to form a bent part (17), and other identical parts are given the same reference numerals and explanations are omitted. Then, the fifth
As shown in the figure, the inner diameter of the straight pipe part of the valve (1) is Dl,
When the inner diameter of the top of the bent part (17) is D2, and the inner diameter of the middle part of the bent surface is D3.

D, <Dl<D3, and the main amalgam (5) is a base metal consisting of 50 to 65% by weight of bismuth and 35 to 50% by weight of tin, and mercury added to 1 to 12% by weight of the entire amalgam. % is used.

Since the main amalgam (5) of this lamp is also composed of the above-mentioned bismuth-tin amalgam, the tube wall temperature of this fluorescent lamp is about 70°C, similar to the above-mentioned figure 8 fluorescent lamp. The temperature is about 6. OX 10-'Torr
The mercury vapor pressure inside the tube is maintained at a certain level, and even if the environmental temperature fluctuates considerably, the mercury vapor pressure inside the tube does not change much.

In addition, since the folded part (14) of this U-shaped fluorescent lamp is configured as described above, the cooling capacity of the folded part (14) is appropriately weak, and in this case as well, the base is increased as in the above-mentioned 8-shaped fluorescent lamp. The mercury vapor pressure inside the tube does not fluctuate much even when the lamp is turned on in the base down condition or when the base is down, and the mercury vapor pressure inside the tube does not change much even if the environmental temperature fluctuates considerably. Therefore, it maintains approximately constant luminous efficiency at 5N under various usage conditions.

Furthermore, even if this U-shaped fluorescent lamp is turned on with the base down, mercury does not condense in the folded part (14), so there is no change in brightness due to dripping of condensed mercury, and there is no natural oxidation during the amalgam manufacturing process. Therefore, the variation in lamp characteristics is reduced by 1°.
Tin amalgam is used not only as the main amalgam for both types of fluorescent lamps mentioned above, but also for adjusting the mercury vapor pressure inside the tube in other types of fluorescent lamps, germicidal lamps, and various types of ultraviolet lamps. The mercury vapor pressure in the tube is kept almost at an appropriate level over the wall temperature range, and is used in various low-pressure mercury vapor discharge lamps with a medium tube wall temperature of around 70°C. It has the advantage of maintaining pressure.

〔Effect of the invention〕

Thus, the first claim of the present invention is that bismuth is 50 to 50%.
The amalgam is made of a base metal containing 65% by weight and 35-50% by weight of tin, and 1-12% by weight of mercury based on the total amalgam, and is sealed in various low-pressure mercury vapor discharge lamps.
It maintains luminous efficiency by keeping the mercury vapor pressure inside the tube within an appropriate range and maintaining a good discharge state over a wide tube wall temperature range, and is particularly suitable for lamps with medium tube wall temperatures. Furthermore, this amalgam has the advantage that there is little natural oxidation during the manufacturing process, so there is little variation in the characteristics of the resulting lamps.

In addition, the second aspect of the present invention is that a low-pressure mercury vapor discharge lamp is constructed by sealing the amalgam according to claim 1 in a bulb with a pair of filaments sealed at both ends, so that it can be used in a wide tube wall temperature range. It maintains good luminous efficiency by keeping the mercury vapor pressure inside the tube appropriate, and is particularly suitable for bulbs with moderate bulb temperatures of about 70°C.

Furthermore, the third aspect of the present invention is a bulb formed by sealing a pair of filaments at both ends of a bulb forming a continuous discharge path having both ends in the same direction and at least one folded part in the opposite direction from the both ends. In a low-pressure mercury vapor discharge lamp, when the bulb is lit and the folded part is located below the line of gravity, the inner surface of the bulb near this folded part becomes the coldest part, and the folded part is located above the line of gravity. when located.

This low-pressure mercury vapor discharge lamp has a shape in which the inner surface of the bulb other than the folded portion is the coldest part, and the amalgam according to claim 1 is sealed inside the bulb, so it can of course be used for horizontal lighting. , the mercury vapor pressure inside the tube remains almost constant both when the lamp is turned on in the base-up state and when the lamp is turned on in the base-down state, and the mercury vapor pressure inside the tube does not change much even with large changes in the environmental temperature. It has the advantage of always maintaining good luminous efficiency, and even if it is turned on in a base-down state, condensed mercury will not drip onto the filament and the mercury vapor pressure inside the tube will fluctuate, causing sudden changes in brightness. .

[Brief explanation of drawings]

FIG. 1 is a graph of mercury vapor pressure curves for the amalgam of the present invention, a conventional amalgam to be compared, and pure mercury, and FIG. 2 is a graph of an embodiment of a low-pressure mercury vapor discharge lamp filled with the amalgam of the present invention. FIG. 3 is a sectional view showing the dimensions of the main part, FIG. 4 is a sectional view of another embodiment, and FIG. 5 is a sectional view showing the dimensions of the main part. (1)... Bulb, (11), (16)... Glass bulb, (12)... Tip surface, (13)... Communication portion, (14)... Folded portion, (17 )...bending part,
(18)...Bending corner, (2)...Discharge path, (3
)... Fluorescent film, (4)... Stem, (41)...
Lead wire, (42)...Filament (5)...Main amalgam, (6)...Auxiliary amalgam

Claims (3)

[Claims] (1) A base metal consisting of 50 to 65% by weight of bismuth and 35 to 50% by weight of tin contains 1 to 12% by weight of mercury based on the total weight of the amalgam, and is sealed in a low-pressure mercury vapor discharge lamp. Amalgam. (2) A low-pressure mercury vapor discharge lamp characterized in that the amalgam according to claim 1 is sealed in a bulb having a pair of filaments sealed at both ends. (3) A low-pressure mercury vapor discharger formed by sealing a pair of filaments at both ends of a bulb forming a continuous discharge path with both ends in the same direction and at least one folded part in the opposite direction. In an electric light, when the above-mentioned bulb is turned on and the folded part is located below the line of gravity, the inner surface of the bulb near this folded part becomes the coldest part,
Further, when the folded part is located above the line of gravity, the inner surface of the bulb other than the folded part is the coldest part, and the amalgam according to claim 1 is sealed in the bulb. A low-pressure mercury vapor discharge lamp characterized by: