JPH0479119A - Manufacture of fluorescent lamp - Google Patents

Abstract

PURPOSE:To restrain deformation of a glass bulb that could be caused by thermal distortion by mixing metal oxide particles of diameter less than 1mum in a water soluble solvent, applying the mixture to the glass bulb, and drying the mixture so as to form a protecting film, and forming a fluorescent film by means of mixing of fluorescent particles in an application solvent, application of the mixture to the glass tube, and drying of the mixture, and baking the fluorescent film after that. CONSTITUTION:Metal oxide particles of diameter less than 1mum are mixed in a water soluble solvent and the mixture is applied to a glass bulb and dried so as to form a protecting film 7 and particles of fluorescent material are mixed in an application solvent and the mixture is applied to the glass bulb to form a fluorescent film 10 and then the film 10 is baked. Since the protecting film 7 which forms on the inner surface of the glass bulb 6 is formed by means of application of particles of a metal oxide e.g. alumina on the inner surface of the glass bulb 6 and removal of the water soluble solvent through drying, the glass bulb 6 is restrained from being deformed by thermal distortion. The glass bulb 6 is thus prevented from being deformed and broken by thermal distortion at the formation of the protecting film 7 and the fluorescent film 10 and uniform film thickness can be offered over the inner surface of the glass bulb 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a fluorescent lamp, and more particularly to a method for sequentially forming a protective film and a fluorescent film on the inner surface of a glass bulb.

(Prior art) In recent years, efforts have been made to slow down the coloring reaction of fluorescent substances to the inner surface of the glass bulb when lighting a fluorescent lamp, improve the maintenance rate of the luminous flux emitted by the filament, and furthermore prevent deterioration of the glass bulb. , a structure is adopted in which a protective film is formed between the inner surface of the glass bulb and the phosphor film. In particular, this structure consists of configuring the glass bulb in an H-shape, double H-shape, or U-shape, and connecting parts and bent parts. It is often used in single-capped fluorescent lamps, so-called compact fluorescent lamps.

This protective film is made by mixing metal oxide particles such as alumina with a coating solvent such as nitrocellulose or butyl acetate, applying it to the inner surface of the glass bulb, and baking it at a temperature of around 550°C.
A method of forming by removing the solvent has been adopted.

Generally, the fluorescent film of a fluorescent lamp is formed by mixing phosphor particles in a coating solvent such as nitrocellulose, coating the mixture on the inner surface of a glass bulb, and baking the mixture at a temperature of about 550°C.

Therefore, when forming a protective film and a fluorescent film in order on the inner surface of a glass bulb, the above-mentioned conventional method for forming a protective film requires
The glass bulb is heated to a temperature of around 550° C. over multiple cycles.

(Problems to be Solved by the Invention) As described above, in order to form a protective film and a fluorescent film on the inner surface of a glass bulb, the glass bulb is heated in a dish cycle, and the glass bulb is heated due to thermal distortion caused by the heating in the dish cycle. The deformation of tends to be larger than the deformation caused by - times of heating.

Fluorescent lamps such as this compact type are JIS
Since the glass bulb width dimension, opening end surface dimension, etc. are regulated by standards, deformation of the glass bulb beyond the allowable range poses a problem that reduces the yield of fluorescent lamps.

Further, deformation of the open end of the glass bulb and change in the bulb width dimension pose a problem that may make it impossible to attach the stem in the sealing process.

Furthermore, there is also the problem that the glass bulb is easily damaged due to deformation stress caused by thermal distortion during firing of the fluorescent film.

In addition, in the conventional method for forming a protective film, the surface of the protective film has unevenness, which causes local unevenness in the film thickness, and furthermore, the film thickness varies significantly depending on the inner surface of the glass bulb. Another problem is that the mechanical strength of the glass bulb on which the protective film is formed becomes non-uniform.

For example, alumina 4w196, butyl acetate 95w196
Looking at the cross section of the protective film formed on the inner surface of the H-shaped glass bulb using a solution containing 1 wt% of nitrocellulose, as shown in FIGS. The thickness of the protective film 32 is 2.0
~3.5 μ mark, and as shown in FIGS. 29 and 30, the thickness of the protective film 32 at the approximate center of the straight pipe portion of the glass bulb 31 is 50 to 5.5 Wm, and the thickness of the protective film 32 is 50 to 5.5 Wm, The thickness of the protective film at approximately the center of the tube portion is approximately twice that of the thickness near the communication portion, and the thickness varies by ±1. Unevenness of ejm has occurred.

When a fluorescent film is formed on this protective film with an uneven surface,
Another problem is that the thickness of the fluorescent film tends to become locally non-uniform, and brightness unevenness tends to occur when the fluorescent lamp is turned on.

An object of the present invention is to solve the above-mentioned problems, and to prevent deformation of the glass bulb due to thermal distortion during the formation of the protective film and the fluorescent film.
It is an object of the present invention to provide a method for manufacturing a fluorescent lamp which can prevent breakage, and can form a protective film having a smooth surface without irregularities and having a uniform thickness over the inner surface of a glass bulb.

[Structure of the invention]

(Means for Solving the Problems) A method for manufacturing a fluorescent lamp according to the present invention is a method for manufacturing a fluorescent lamp in which a protective film and a fluorescent film are sequentially laminated on the inner surface of a glass bulb, wherein the protective film has a diameter of 1 jffi or less. The fluorescent film is formed by mixing metal oxide particles in a water-soluble solvent and applying the mixture and drying the mixture, and the fluorescent film is formed by mixing phosphor particles in a coating solvent, applying the mixture and drying the mixture, and then baking the mixture. be.

(Function) The method for manufacturing a fluorescent lamp of the present invention involves mixing metal oxide particles with a diameter of 11 or less in a water-soluble solvent, applying the mixture to the inner surface of a glass bulb and drying it to form a protective film, and then adding phosphor particles. Since the fluorescent film is formed by mixing it with a coating solvent, applying it, drying it, and then baking it, it is possible to suppress the deformation of the glass bulb due to thermal distortion, thereby preventing a decrease in the yield of fluorescent lamps.

In addition, the surface of the protective film formed is smooth with no irregularities, and the thickness of the protective film inside the glass bulb is formed anywhere between the lines, so the thickness of the fluorescent film formed on this protective film is also Glass buff 1 that is uniform and prevents uneven brightness when lighting a fluorescent lamp, and has a protective film and a fluorescent film formed on it.
Strengthen the mechanical strength of the block.

(Example) An example of the method for manufacturing a fluorescent lamp of the present invention will be described based on the drawings.

First, as a first embodiment, a method for manufacturing an H-shaped fluorescent lamp will be described with reference to FIGS. 1 to 8.

In FIG. 1, 2 has open ends 1 and 2 formed at both ends.
By holding the glass bulbs 3 in the form of straight tubes in parallel and spaced apart, and heating and blowing out the opposing side surfaces near one open end 1, the blow-out parts 4, 4 with open ends are formed. Form. Then, while heating and melting both the blow-through parts 4, 4, the double-sided tube-shaped glass bulbs 3, 3 are brought close to each other so that the openings at their tips are aligned with each other, and as shown in FIG. 4 are interconnected so as to communicate with each other to form a communicating portion 5, thereby forming a figure 8-shaped glass bulb 6.

Next, as shown in FIG. 3, hold the figure-8-shaped glass bulb 6 with the communicating part 5 facing upward, and apply a water-soluble solvent to the inner surface of the glass bulb 6.
For example, in pure water, metal oxide particles with a particle size of 0.1 μm are added.
4v1% of alumina is mixed and applied to form a protective coating. When this glass bulb 6 is air-dried at a temperature of 50° C., the pure water in the protective coating film evaporates and becomes a protective film 7 made of alumina.

This protective film 7 has a smooth surface with no irregularities in the vicinity of the communication portion 5 of the glass bulb 6, as shown in FIGS. 25 and 26 show cross sections of the protective film 7 at approximately the center of the straight pipe portion of the glass bulb 6, for example, at point R and 8 points. It has a smooth surface and is formed to a thickness of 0.7 to 1.0 μm.

Thereafter, as shown in FIG. 4, sealing margins 8 and 9 are formed in the vicinity of both opening ends 12 by removing the protective film 7, respectively.

Next, as shown in FIG. 5, phosphor particles are mixed with a coating solvent such as nitrocellulose and coated on the inner surface of the glass bulb 6. Then, after applying it and letting it air dry for a while,
A phosphor coating is formed. In this state, the temperature is 550℃
When the glass bulb 6 is heated, nitrocellulose is removed from the phosphor coating, and this phosphor coating is fired to become the phosphor film 10.

Thereafter, as shown in FIG. 6, the fluorescent film 10 is removed at the sealing margin 9 without exposing the peripheral portion of the protective film 70.

Next, as shown in FIG.
, 1 are melted and closed to form closed end surfaces II and II.

At this time, a part of the fluorescent film 1G is also stretched along the closed end surfaces 11, and the fluorescent film 10 is formed in a film shape on the inner surface of each closed end surface 11.

Then, as shown in FIG. 8, the lower end of the stem 14, which is made of a flare 13 with a filament 12 implanted therein, is aligned with the other open end portions 2, 2, and the sealing gap 9 is heated and melted to seal the stem 14. The bulb 6 is pumped up from below and sealed together, exhausted from an exhaust pipe (not shown) and filled with a suitable amount of mercury along with a starting gas such as argon to complete a figure 8-shaped fluorescent lamp.

Next, as a second embodiment, a method for manufacturing a double H-shaped fluorescent lamp will be described with reference to FIGS. 9 to 16.

First, as shown in FIG. 9, four straight tube-shaped glass bulbs 3 are arranged in parallel on the same plane, and the vicinity of one open end 1.1 of the two sets is connected to connect the communicating portion 5. 5, and connect the other open end portions 2, 2 of the two intermediate straight tube-shaped glass bulbs 3.3 to form an intermediate communication portion 5 to form a double H-shaped glass bulb. form 15. Then, similar to the first embodiment, a protective film 7 is formed inside the glass bulb 15.

Next, as shown in FIG. 10, the protective film 7 near each open end 1, 2 of the double H-shaped glass bulb 15 is removed to form a sealing pad 6.17.

Next, as shown in FIG. 11, a fluorescent film 10 is formed in the same manner as in the first embodiment. Then, as shown in FIG. 12, the sealing margin 16. The fluorescent film 10 formed on the phosphor film 17 is sealed and removed so as not to expose the protective film 7 in the vicinity of the film 16 and 17.

Next, as shown in FIG. 13, one open end 1 of the glass bulb 3 is closed to form a closed end surface 11. Then, a stem 14 made of a flare 13 in which a filament 12 is implanted is sealed to the other open end 2 of the glass bulb 3 located on the outside of the surface, and the other opening of the glass bulb 3 located on the inside is sealed. The end portions 2 are each closed to form a closed end surface 11. Further, a suitable amount of mercury is filled in with a starting gas such as argon after being exhausted from an exhaust pipe (not shown), thereby completing a double figure-eight fluorescent lamp.

In addition, the method for manufacturing double figure-eight fluorescent lamps is as follows:
In addition to the above method, there is also a method of connecting two U-shaped glass bulbs 6 as shown in FIG.

In this method, first, as shown in FIG. 14, a stem 14 made of a flare 13 in which a filament 12 is implanted is sealed to one of the other open ends 2 of each glass bulb 6. One open end 2 is closed to form a closed end surface 11. Next, as shown in Figure 15,
In order to allow the glass bulbs 6 to communicate with each other, a blowout portion 18 is formed by removing the protective film 7 and the fluorescent film 10 at a predetermined portion near the closed end face 11 that was later closed. Then, as shown in FIG. 16, this blow-out part 18 is heated and melted to form a communication part 19 between the two glass bulbs 6, and after exhausting, a starting gas such as argon and mercury are filled in. It is also possible to make a figure-8 fluorescent lamp.

Next, as a third embodiment, a method for manufacturing a U-shaped fluorescent lamp will be described with reference to FIGS. 17 to 22.

First, as shown in FIG. 17, a straight glass bulb 3
The central part of the glass bulb 3 is bent without being heated, and the bent glass bulbs 3 are held parallel to each other at a distance to form a U-shaped glass bulb 20.

Next, as shown in FIG. 18, a protective film 7 is formed on the inner surface of the glass pulp 20 in the same manner as in the first and second embodiments.

Thereafter, as shown in FIG. 19, the protective film 7 near both opening ends 2] and 2+ of the glass bulb 20 is removed to form sealing margins 22 and 22.

Next, as shown in FIG. 20, a fluorescent film 10 is formed in the same manner as in the first and second embodiments. Then, as shown in FIG. 21, the fluorescent film IO formed on the sealing margin 22.22 of the glass bulb 20 is removed so as not to expose the protective film 7 near the sealing margin 22.22.

Next, as shown in FIG.
, 2+, exhaust from an exhaust pipe (not shown), and fill in an appropriate amount of mercury with a starting gas such as argon.
The letter-shaped fluorescent lamp is completed.

Thus, according to the above embodiment, the glass bulb 6 constituting a U-shaped, double 8-shaped, U-shaped, etc. fluorescent lamp
, 15.20, the protective film 7 is formed on the inner surface of the glass bulb 6°+5. Apply to the inner surface of Hl,
Since the glass bulbs 6, 15 and 20 are heated only once when forming the fluorescent film 10, the glass bulbs 6, 15 and 20 are heated only once when forming the fluorescent film 10.
．． 20, deformation caused by thermal strain is suppressed. Therefore, the glass bulb 6, 15.2 during firing of the phosphor coating
In addition, the glass bulb 6, 15.20 will not be deformed beyond the allowable range, and will comply with JIS standards.
Standards are met, the stem 14 can always be sealed, and the yield of fluorescent lamps is improved and increased.

In addition, the protective film 7 formed on the inner surface of the glass bulb 6, 15, 20 is, for example, located at points P and Q near the communicating portion 5 of the glass bulb 6 shown in FIGS. Second
As shown in the cross-sectional shape of the protective film 7 at points R and 8 at the approximate center of the straight pipe section shown in FIG. .2
The film thickness is formed between the paths over the entire inner surface of the 0. Therefore, the thickness of the fluorescent film 10 laminated on the protective layer 7 can be formed to be approximately uniform, which prevents uneven brightness when the fluorescent lamp is turned on and strengthens the mechanical strength of the fluorescent lamp. You can also do that.

The protective film 7 is sandwiched between the inner surface of the glass bulb 3 and the fluorescent film 10, and is further sealed by a sealing margin of 8,9°+6. 17.
Since the peripheral edge of the protective film 7 near 22 is also covered with the fluorescent film 10, the protective film 7 will not peel off from the inner surface of the glass bulb 3.

In the above embodiment, alumina as a metal oxide particle was used as protection@7 as an example, but in addition to alumina,
The same effect can be obtained even if the protective film 7 is formed of titanium oxide, silicon oxide, zinc oxide, etc. having a grain size of 11 or less.

〔Effect of the invention〕

According to the method for manufacturing a fluorescent lamp of the present invention, the protective film on the inner surface of the glass bulb is formed by mixing metal oxide particles with a diameter of 11ffi or more in a water-soluble solvent, coating the mixture, and drying the coating. Since heating is performed only once during firing to form the fluorescent film, deformation of the glass bulb due to thermal strain can be suppressed.

Therefore, a glass bulb in which a protective film and a fluorescent film are sequentially formed complies with JIS standards, prevents the stem from being impossible to seal due to breakage or deformation, and improves the yield of fluorescent lamps.

In addition, the surface of the protective film formed inside the glass bulb is smooth with no irregularities, and the film is thick enough to be formed over the entire inner surface of the glass bulb. The thickness of the fluorescent film can also be formed uniformly, preventing uneven brightness when the fluorescent lamp is turned on, and increasing the mechanical strength of the fluorescent lamp.

[Brief explanation of the drawing]

1 to 8 are explanatory diagrams explaining the first embodiment of the method for manufacturing a fluorescent lamp of the present invention in the order of steps, and FIGS. 9 to 1
3 is an explanatory diagram explaining the second embodiment same as above in the order of steps, FIGS. 14 to 16 are explanatory diagrams explaining the second embodiment same as above in the order of other steps, and FIGS. 17 to 22 are the same as above. Explanatory diagrams explaining the third embodiment in the order of steps, FIGS. 23 and 24
The figure is a sectional view of the protective film near the communication part of the fluorescent lamp according to the first embodiment, FIGS. 25 and 26 are sectional views of the protective film approximately at the center of the straight tube part, and Figure 28 is
29 and 30, which are cross-sectional views of the protective film near the communication part of the H-shaped glass bulb manufactured by the conventional fluorescent lamp manufacturing method, show the protective film approximately at the center of the straight tube part of the same glass bulb. FIG. 6. Glass bulb, 7. Protective film, 10. Fluorescent film. July 20, 1990 Inventor Kimio Shiraiwa

Claims (1)

[Claims] (1) In a method for manufacturing a fluorescent lamp in which a protective film and a fluorescent film are sequentially laminated on the inner surface of a glass bulb, the protective film is formed by coating metal oxide particles with a diameter of 1 μm or less mixed in a water-soluble solvent, and drying. A method for manufacturing a fluorescent lamp, characterized in that the fluorescent film is formed by mixing phosphor particles in a coating solvent, coating the mixture, drying it, and then baking it.