JPH0536377A - Bulb - Google Patents

Abstract

(57) [Summary] [Objective] To provide a bulb with improved lamp characteristics by adsorbing impurities in the bulb. [Structure] Inside the valve, the specific surface area is 100m ² / G or more of ultrafine particles having a particle size of 44 to 74 µm and a charging tendency of +3.0 µC / g or more to the reduced iron powder, or a powder having a pH of 9 or more in an aqueous solution of 20% by weight. It is characterized by Since the powder of the present invention adsorbs CO, CO ₂ and H ₂ O in the bulb, impurities do not remain in the bulb, and the discharge voltage can be lowered in the case of a fluorescent lamp. In the case of an incandescent light bulb, the life characteristics are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for purifying impurities in a bulb of a bulb such as a fluorescent lamp or an incandescent lamp.

[0002]

2. Description of the Related Art Recently, a three-wavelength emission type phosphor has been used as a phosphor of a rapid start type fluorescent lamp. The rapid start type fluorescent lamp is formed by forming a transparent conductive film (EC film = NES film) on the inner surface of the arc tube bulb, and forming a fluorescent material film on the inner surface of the EC film. Since the Nesa membrane plays a role of reducing the resistance of the tube wall, it has a characteristic that the starting is easy. When a three-wavelength emission type phosphor is used as the phosphor, there is an advantage that high brightness and high color rendering can be obtained. However, in this type of rapid start type fluorescent lamp, there are some cases in which the lighting start voltage Vs of the lamp becomes high.

There are various causes for increasing the lighting start voltage, and it is conceivable that the impure gas in the bulb affects one of them. It has been known that a normal fluorescent lamp has a high lighting start voltage Vs when impurities such as carbon dioxide CO, carbon monoxide CO ₂ and water H ₂ O are present in the bulb.

For this reason, various measures have been taken in the process of manufacturing the lamp so that no impure gas remains in the bulb, and the bulb wall and the mount components are heated, or gas is replaced by a method such as gas replacement. Care is taken not to release the impurities that have been attached or adsorbed to the mount components or to the mount components, or to prevent the impurities from adhering to or adsorbing the phosphor. However, these measures are not perfect, and impurities may be knocked out from the bulb wall, mount components, etc. during lighting. When activated by heating, CO, CO ₂ and H ₂ O may be released from this emitter. Therefore, it is impossible to completely avoid releasing CO and CO ₂ into the valve.

On the other hand, in the case of an incandescent light bulb, for example, a light bulb used for a traffic signal light, there are some lamps whose life characteristics are significantly deteriorated due to subtle changes in exhaust conditions. In the case of an incandescent light bulb, if moisture H ₂ O remains in the bulb, there is a problem that the filamentation causes a water cycle and early disconnection. Although a getter or the like is used to prevent such a water cycle, there are drawbacks such as insufficient moisture adsorption performance and high cost.

[0006] In the case of an incandescent light bulb, even if oxygen, nitrogen, CO, or CO ₂ remains, the effect is small if the remaining amount is small, but there is a demand to avoid even a small amount of water H ₂ O remaining. is there.

[0007]

That is, regardless of whether the bulb is a fluorescent lamp or an incandescent lamp, if impurities remain in the bulb, the starting voltage will rise and the life characteristics will deteriorate. There is a demand to eliminate such residual impurities.

The present invention has been made under these circumstances, and an object thereof is to provide a bulb in which impurities such as CO, CO ₂ and H ₂ O do not remain in the valve. To do.

[0009]

The first aspect of the present invention is characterized in that a powder having a charging tendency of +3.0 μC / g or more for reduced iron powder having a particle diameter of 44 to 74 μm is provided inside the valve. And The second aspect of the present invention is that inside the valve,
A powder having a pH of 9 or more in a 20 wt% aqueous solution is additionally provided.

[0010]

According to the first aspect of the present invention, the particle size is 44 to 74.
The powder having a charging tendency of +3.0 μC / g or more for the reduced iron powder of μm adsorbs impurities in the valve, and CO
And CO ₂ and H ₂ O do not remain. Therefore, in the case of a fluorescent lamp, the starting voltage can be lowered, and in the case of an incandescent lamp, the life characteristics are improved.

According to the second aspect of the present invention, a powder having a pH of 9 or more in a 20 wt% aqueous solution adsorbs impurities in the valve, and CO, CO ₂ and H ₂ are stored in the valve.
Do not allow O etc. to remain. Also in this case, when applied to a fluorescent lamp, the starting voltage can be lowered, and when used for an incandescent lamp, the life characteristics are improved.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS.

The drawing shows a straight tube type rapid start fluorescent lamp, 1 being a glass bulb. Both ends of the valve 1 are airtightly closed by flare stems 2 and 2, and a pair of lead wires 3 ...

A hot cathode made of tungsten or the like, that is, filaments 4 and 4, is provided between the lead wires 3 and 3 of both the stems 2 and 2. The filaments 4, 4
Although not shown in the drawing, an electron emitting substance such as barium oxide is applied.

A transparent conductive film (EC film = nesa film) 5 such as tin oxide is formed on the inner surface of the bulb 1, and the phosphor film 6 is formed on the surface of the transparent conductive film 5. Are formed. The phosphor coating 6 uses a three-wavelength light-emitting phosphor, and specifically, Y ₂ O ₃ : Eu (red), (Re, Tb, Ce). (P, Si) O ₄ (green). ) (Where Re is a rare earth element) and BaMg ₂ Al ₁₁
It is composed by mixing each phosphor powder of O ₂₇ : Eu (blue).

The phosphor has a specific surface area of 100 m ²
/ G or more of ultrafine particles of metal oxide are attached. That is, as shown in FIG. 1B, the phosphor powder 1
On the surface of 0, for example, a powder of a metal oxide such as MgO 2
0 is attached, and the powder 20 has a specific surface area of 10
0 m ² Therefore, the metal oxide powder 20 has a charge tendency of +3.0 μC / g or more, or has a pH of 9 or more (alkaline) in a 20 wt% aqueous solution.

As shown in FIG. 2, the charging tendency of the metal oxide has a property of being positively charged and a property of being negatively charged depending on the type. MgO is positively charged, but Si is
O ₂ tends to be negatively charged. And, in place of Mg, at least one kind of metal oxide selected from the oxides of Ca, Sr, Ba, and Zn has a property of positive charging tendency. In addition, instead of SiO ₂ , Sn, Ti, G
At least one selected from the oxides of e, Ta, Nb, V, and Mo has a property that the charging tendency is negative.

In the case of this embodiment, a powder 20 having a positive charging tendency and having a charging tendency of +3.0 μC / g or more for the reduced iron powder having a particle diameter of 44 to 74 μm is used.

Such a powder 20 has the property that the pH of the powder 20 when dissolved in a 20% by weight aqueous solution becomes 9 or more (alkaline). It should be noted that when the pH is 7 or more, it is alkaline,
It is considered acidic when the pH is less than 7. The bulb 1 is filled with a predetermined amount of mercury and a rare gas such as argon.

The fluorescent lamp having such a structure has the fluorescent substance 10 of the fluorescent substance coating 6 formed on the inner surface of the bulb 1,
A powder 20 having a charge tendency of +3.0 μC / g or more, such as MgO, is attached to the reduced iron powder having a particle diameter of 44 to 74 μm. MgO has a strong property of adsorbing CO, CO ₂ and H ₂ O, but has a property of dissociating at 540 ° C., and when admixed with a phosphor, CO or C adsorbed
O ₂ and H ₂ O are released in the baking step of the phosphor film to clean the inside of the valve 1, and the MgO powder 20 mainly remains in the valve 1 after the subsequent sealing step. It exerts a getter function by adsorbing impurities such as CO, CO ₂ and H ₂ O. It was adsorbed on MgO-
OH group reacts with CO _{2 to} cause Mg (OH) or Mg on the surface.
It is speculated that a compound of CO ₃ is produced. For this reason, since the impurities do not remain in the valve 1 in a floating state, the starting voltage Vs can be lowered and the starting becomes easy.

FIG. 3 shows the result of measuring the relationship between the charging tendency and the starting voltage Vs using a powder of MgO for a 40 W rapid start type fluorescent lamp. From the measurement results, the powder 20 having a charge tendency of +3.0 μC / g or more with respect to the reduced iron powder having a particle diameter of 44 to 74 μm
It has been found that the use of the can reduce the starting voltage Vs and facilitate the starting.

FIG. 4 also shows the result of measuring the relationship between the pH value and the starting voltage Vs using a powder of MgO for a rapid start type fluorescent lamp of 40 W.
From this measurement result, it was found that when the powder 20 having a pH of 9 or more was used, the starting voltage Vs could be lowered and the starting could be facilitated.

The specific surface area is 100 m ^2. / G or more, and if it is more than this, the surface area is large, so that adsorption of impurities is good, and if it is less than this, a sufficient effect cannot be expected. Next, a second embodiment shown in FIGS. 5 to 8 will be described.

The second embodiment shows an incandescent light bulb, for example, a traffic signal light bulb, and 30 is an R-shaped bulb. One end of the valve 30 is closed at its one end by a stem 31, and a pair of lead wires 32, 32 are hermetically penetrated through the stem 31. A filament 33 is stretched around the inner ends of the lead wires 32, 32, and the central portion of the filament 33 is supported by an anchor wire 34. A base 35 is attached to the neck of the valve 30.

A white light diffusion film 36 is formed on the inner surface of the bulb 30.
The light diffusion film 36 is formed by adhering silica SiO ₂ powder 37 to the inner surface of the bulb 30 by means such as electrostatic coating.

In the case of this embodiment, as shown in FIG. 5 (B), the light diffusion film 36 contains 1 weight of powder 40 of metal oxide such as MgO in addition to silica powder 37. %, And the powder 40 has a specific surface area of 100 m ² / G or more, whereby the powder 40 of the metal oxide has a charge tendency of +3.0 μC / g or more, or has a pH of 9 or more (alkaline).

In the case of the incandescent light bulb having such a structure, the silica powder of the light diffusion film 36 formed on the inner surface of the bulb 30 is
Since MgO powder having a charge tendency of +3.0 μC / g or more with respect to the reduced iron powder having a particle diameter of 44 to 74 μm is attached, the MgO powder 40 has impurities remaining in the valve 1, particularly It exerts a getter function by adsorbing H ₂ O. Therefore, since H ₂ O does not remain in the bulb 1, no water cycle is generated and the filament has a long life.

FIG. 6 shows the relationship between the specific surface area of the MgO powder 40 and the lamp life when it is applied to a 60 W incandescent lamp. From the measurement result, the specific surface area of the powder 40 is 100 m ^2. It was found that the effect was low unless it was more than / g. It is considered that when the surface area is small, the contact area with impurities is small, so that the adsorption performance becomes low.
Therefore, the specific surface area of the MgO powder 40 is 100 m ^2. / G or more is required.

FIG. 7 shows the results of measurement of the relationship between the charging tendency of the metal oxide mixed in the silica powder and the lamp life. The charging tendency of the metal oxide is as shown in FIG.
The oxides of Mg, Ca, Sr, Ba, and Zn have the property of being positively charged, and conversely, Si, Sn, Ti, Ge, and T.
Each oxide of a, Nb, V, and Mo has a property that the charging tendency is negative.

When each of these oxides is selected and the relationship between the charging tendency and the lamp life is measured, the charging tendency is −3.0 μC / g or less, or +3.0 μC / g, as shown in FIG.
It has been found that it is better to be charged more than g. That is, the charging tendency exceeds −3.0 μC / g and +3.0 μC.
If it is less than C / g, the water content is H because the charging tendency is neutral.
_It is considered that the force for taking in ₂ O is weak, and therefore impurities remain in the valve.

On the other hand, when the charging tendency to the reduced iron powder is −3.0 μC / g or less, or +3.0 μC / g
In the above cases, the tendency of charging is biased, and the moisture H ₂
It is considered that the performance of adsorbing O is improved and H ₂ O is not left in the valve, so that the life is extended. Further, FIG. 8 shows the results of measuring the relationship between the pH value of the metal oxide and the lamp life.

By selecting metal oxides having different pH values,
When the relationship between the value and the lamp life was measured, it was found that better results were obtained when the pH value was 5 or less (acidic) or 9 or more (alkaline). When the pH value is 5 or lower, or 9 or higher, the acidity and alkalinity are both strong, so that the ability to adsorb water H ₂ O is strong, and therefore H ₂ O does not remain in the valve, which prolongs the service life. It is considered to be a thing.

As can be understood from the above description, what is common to fluorescent lamps and incandescent lamps is that the specific surface area of the bulb is 100 m ^2. / G or more, the powder has a particle size of 44 to 74 μm, and the charging tendency to the reduced iron powder is +3.0 μC / g or more, or 20% by weight.
If the pH value in the aqueous solution of is not less than 9 (alkaline), it exerts a getter action of adsorbing impurities in the valve,
For fluorescent lamps, it is effective in improving starting characteristics.
Incandescent light bulbs are effective in improving life characteristics.

In addition to the above range, the charging tendency is −
Even when the pH value in an aqueous solution of 3.0 μC / g or less, or 20% by weight is 5 or less (acidic), a getter action of adsorbing water in the bulb is exhibited, which is effective in improving the life characteristics of the incandescent lamp. The present invention is not limited to the above embodiment.

That is, the fluorescent lamp of the present invention is not limited to the rapid start type fluorescent lamp, but may be an ordinary fluorescent lamp, and the lamp shape may be various shapes such as a straight tube shape, a ring shape and a compact bent shape. Can be implemented in the case of.

[0036]

As described above, according to the first aspect of the present invention, powder having a charging tendency of +3.0 μC / g or more adsorbs CO, CO ₂ and H ₂ O in the valve and leaves them. Since it is eliminated, the starting voltage can be lowered in the case of a fluorescent lamp, and the life characteristics are improved in the case of an incandescent lamp.

According to the second aspect of the present invention, the pH is 9
The above powder adsorbs impurities in the bulb, and in this case also, when applied to a fluorescent lamp, the starting voltage can be lowered, and when used in an incandescent lamp, life characteristics are improved.

[Brief description of drawings]

1 shows a first embodiment of the present invention, FIG. 1 (A) is a sectional view of a rapid start type fluorescent lamp, and FIG. 1 (B) is a state in which MgO powder is adhered to a phosphor. Pattern diagram.

FIG. 2 is a diagram showing a charging tendency of a metal oxide powder.

FIG. 3 is a characteristic diagram showing a relationship between a charging tendency of a metal oxide powder and a starting voltage of a fluorescent lamp.

FIG. 4 is a characteristic diagram showing the relationship between the pH value of the metal oxide powder and the starting voltage of the fluorescent lamp.

5A and 5B show a second embodiment of the present invention, FIG. 5A is a sectional view of an incandescent lamp, and FIG. 5B is a schematic view showing a state where MgO powder is mixed in a diffusion film.

FIG. 6 is a characteristic diagram showing the relationship between the specific surface area of the metal oxide powder and the lamp life.

FIG. 7 is a characteristic diagram showing a relationship between a charging tendency of a metal oxide powder and a lamp life.

FIG. 8 is a characteristic diagram showing the relationship between the pH value of the metal oxide powder and the lamp life.

[Explanation of symbols]

1 ... Valve, 2 ... Stem, 3 ... Lead wire, 4 ... Electrode, 5
... Nesa film, 6 ... Fluorescent film, 10 ... Fluorescent material, 20 ...
MgO powder, 30 ... Valve, 33 ... Filament, 36
... Light diffusion film, 27 ... Silica powder, 40 ... MgO powder.

Continued front page    (72) Inventor Masaaki Tamaya             1st Komukai Toshiba-cho, Sachi-ku, Kawasaki-shi, Kanagawa             Inside the Toshiba Research Institute

Claims (5)

[Claims] 1. A particle diameter of 44 to 74 μm inside the valve.
A tube characterized in that a powder having a charging tendency of m of reduced iron powder of +3.0 μC / g or more is attached. 2. When the bulb is an incandescent light bulb, the tendency of charging on the inner surface of the bulb for the reduced iron powder having a particle size of 44 to 74 μm is outside the range of −3.0 to +3.0 μC / g. The tube according to claim 1, further comprising a powder having a particle. 3. A bulb characterized in that a powder having a pH of 9 or more in a 20% by weight aqueous solution is attached inside the bulb. 4. When the bulb is an incandescent lamp, the bulb has an inner surface provided with a powder having a pH of a 20% by weight aqueous solution other than the range of 5 to 9. The tube according to item 3. 5. The powder has a specific surface area of 100 m ^2. / G
The tube according to any one of claims 1 to 4, which is the above ultrafine particles.