JPH04229943A - Fluorescent lamp and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent color change of a fluorescent film formed at a bent part of a fluorescent lamp having the bent part and a bulb. CONSTITUTION:A fist invention is a fluorescent lamp having a protective film formed for primer of a fluorescent film which is thicker at a bent part than at the other bulb positions. A second invention is a manufacturing method for a fluorescent lamp in which a U-letter shaped glass bulb having suspension liquid for protective film material applied to the inner surface is supported with the bent part directed up, the suspension liquid on the inner surface of the bent part is forcedly heated and dried prior to that at the other bulb positions, and the whole suspension liquid on the inner surface of the bulb is dried. In the first invention, a high density sodium component existing in a glass surface part at the bent part of the bulb is prohibited by the expecially thick protective film, so deterioration of the fluorescent material by the sodium is prevented, coloring of glass by UV-ray 15 prevented, and the mechanical strength at the bent part is improved. In the second invention, the protective film can be expecially formed thick at the bent part of the bulb by forcedly heating and drying time suspension liquid.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

[Industrial Application Field] The present invention relates to a fluorescent lamp in which a fluorescent film as a protective film base is provided on the inner surface of a glass bulb consisting of a bent portion and a straight pipe portion, and the structure of the protective film and the manufacturing method thereof have been improved. be.

0002

2. Description of the Related Art A U-shaped glass bulb is obtained by heating and softening the middle part of a straight glass tube and bending it by 180 degrees. A suspension of a protective film material such as fine alumina powder and a binder in an organic solvent or water is injected onto the inner surface of the U-shaped glass bulb thus obtained, and the bulb is then held with the bent portion facing upward. After supporting and discharging unnecessary suspension, hot air is blown from one open end to dry and bake to form a protective film. Then, a fluorescent film is formed on this protective film, and a fluorescent lamp is formed by a conventional method. In fluorescent lamps manufactured in this way, even if alkaline components contained in the glass of the bulb ooze out, this is blocked by the protective film and does not reach the fluorescent film, so there is no coloring of the bulb itself or deterioration of the fluorescent film. Therefore, it was thought that it would have a long life.

0003

[Problem to be Solved by the Invention] In a U-shaped glass bulb, the bent portion is heated to a high temperature during the bending process and softened, so the sodium in the glass components oozes out, resulting in an abnormally high sodium concentration near the surface. It has become. When ultraviolet rays are incident on such bent portions, the glass becomes colored, and the mechanical strength of the bent portions is reduced due to thermal processing during bending.

Furthermore, if the protective film is formed to have the same thickness at all parts, the fluorescent film at the bent portion of the bulb will be attacked by sodium and deteriorated earlier than that at other parts of the bulb.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a fluorescent lamp having a glass bulb consisting of a bent portion and a straight tube portion, to prevent the fluorescent film in the bent portion from deteriorating early, to prevent coloring of the bulb, and to prevent the bulb from discoloring. It has improved mechanical strength.

[Configuration of the invention]

[0007]

[Means for Solving the Problems] The present invention relates to an improvement in a fluorescent lamp having a glass bulb consisting of a plurality of straight tube sections successively connected through bent sections. By forming the tube thicker at the bent portion than at other parts of the bulb, the fluorescent film at the bent portion is prevented from deteriorating early. The second aspect of the present invention is to support a U-shaped glass bulb whose inner surface is coated with a suspension of protective film material, with the bent portion facing upward, and to force the suspension on the inner surface of the bent portion before applying it to other parts of the bulb. By heating and drying, and then drying the suspension on the entire inner surface of the bulb to form a protective film, which serves as a base film for the fluorescent film, the thickness of the protective film was made thicker at the bent part of the bulb than at other parts. It is something.

[0008]

[Operation] As a result of the bending process, a glass bulb having a bent portion has a significantly high sodium concentration near the glass surface within the bent portion. However, if the protective film is formed thicker in the bent portion than in other parts, even if the sodium concentration is high, the sodium will not ooze out and deteriorate the quality of the fluorescent film. It can also prevent discoloration of glass. In addition, when drying the applied protective film material suspension, if the suspension on the inner surface of the bent part is forcibly heated and dried before drying on other parts, the suspension on the inner surface of the bent part will dry before it flows down naturally. Therefore, it can be formed thicker than other parts. In particular, for suspensions using water as a solvent, water evaporates slowly, so in conventional drying methods there is a lot of gravity flow, making the protective film especially thin at the bends, but with the method of the present invention, the suspension at the bends becomes thinner. Since the liquid is forcibly dried before being dried in other parts, natural flow is extremely small, and the protective film at the bent part can be formed thicker than that at other parts of the valve.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be explained below with reference to illustrated embodiments. FIG. 1 shows an embodiment of the fluorescent lamp of the present invention, in which (1) is a U-shaped glass bulb, (2) is a protective film formed on the inner surface of this bulb (1), and (3) is this U-shaped glass bulb. Fluorescent film formed on the surface of the protective film (2), (4), (4)
are the stems that close both ends of the valve, (5), (5)... are the pairs of introduction lines introduced through these stems (4), (4), and (6), (6) are these Electrode filaments are installed between the tips of the pair of lead-in wires (5), (5), and (7) are exhaust pipes provided in the stems (4), (4). An appropriate amount of mercury is sealed in the bulb (1) along with a starting gas such as argon.

The protective film (2) is formed by applying and baking fine γ-alumina powder, for example, by the method described below, and the portion formed on the inner surface of the bent portion (11) of the bulb (1) is coated with fine powder of γ-alumina and baked. ) The protective film is formed much thicker than the protective film (2) formed on the portion. In the drawings, the thickness of the protective film (2) and its local deviations are exaggerated.

The fluorescent film (3) may be of any type that is normally used in fluorescent lamps; for example, it may be of one type, such as a halophosphate phosphor;
It may also be a mixture of color component phosphors in appropriate proportions.

Next, an example of a method for manufacturing this fluorescent lamp will be explained with reference to FIG. 2 and subsequent figures. First, as shown in Figure 2(a), cut the middle part of a glass tube to an appropriate length by approximately 7
After heating to 00℃, it is bent into a U shape and opened at both ends.
Form into a letter-shaped glass bulb (1).

[0013] Next, a protective film material suspension, such as γ alumina, is dispersed in water together with a water-soluble binder to prepare a protective film material suspension. Next, as shown in FIG. 3(b), the U-shaped glass bulb (1) is supported with the bent part (11) facing upward, and the above-mentioned protective film material suspension (21) is poured into the U-shaped glass bulb (1).
For example, injected from one open end (12) of the valve (1) and discharged from the other open end (13), the valve (1)
Apply the above-mentioned suspension (21) to the inner surface to a uniform thickness,
Stop the injection of the suspension (21).

Then, as shown in FIG. 3(c), the glass bulb (1) immediately after the protective film material suspension (21) is applied.
) is injected with hot air from the outside by a semicircular nozzle (81), and at the same time, one open end (12
). Then, the temperature of the inner surface of the bent part (11) rises rapidly, and water, which is the solvent of the suspension (21), rapidly evaporates due to the air current, and the suspended liquid (21) on the inner surface of the bent part (11) rapidly evaporates. It dries to form a thick protective film (2). However, since the suspended liquid (21) in the valve parts other than the bent part (11) is not forcibly heated, the water evaporates slowly and becomes gradually thinner due to natural flow due to its own weight.

Next, as shown in FIG. 2(d), the valve (
Hot air is blown in from one open end (12) of 1) by a nozzle (82), and is caused to flow out from the other open end (13). Then, the entire inner surface of the valve (1) is heated to a high temperature, and the undried protective film material suspension (21) is rapidly dried. In this drying process, the suspension (21) in the bent part (11) is force-dried immediately after application, so a thick protective film (2) is obtained with less natural flow, and other valve parts are free from natural flow. After the process has progressed to a certain extent, it is forced to dry, resulting in a thin protective film.

[0016] Next, as shown in FIG. 2(e), the protective film (2) at both opening ends (12) and (13) is removed and fired to decompose the binder in the protective film (2). Remove.

Then, as shown in FIG. 3(f), a fluorescent film (3) is formed on the inner surface of the bulb (1) on which the protective film (2) is formed by a conventional method. Then, the fluorescent lamp shown in FIG. 1 is constructed by a conventional method.

In the above-mentioned fluorescent lamp manufactured in this manner, when the glass tube is bent into a U-shape to form the bulb (1), the bent portion (11) is exposed to the high temperature (approximately 700° C.) during bending. Therefore, the sodium component of the glass oozes out and collects near the glass surface, resulting in a significantly high sodium concentration on the surface. However, the fluorescent lamp of the present invention has a U-shaped bend (
11) The protective film (2) on the inner surface is particularly thick compared to other parts, so even if sodium oozes out during lighting, it is blocked by the protective film (2) and does not reach the phosphor. It will not change its quality. In addition, the ultraviolet rays that have passed through the fluorescent film (3) are transmitted through the thick protective film (2) at the bent part (11).
) is almost completely blocked by the bending part (11)
The incidence of ultraviolet rays on the glass is extremely low, and the glass does not become colored despite the high sodium concentration in the glass. Furthermore, since mercury ions are blocked by the thick protective film (2) at the bent portion (11), there is no risk of blackening due to reaction between mercury ions and high concentration sodium in the glass. Furthermore, since the protective film (2) has fine particles bound to the glass surface, it has a reinforcing effect, and the strength decreases due to the concentration of distortion due to the bending of the bent portion (11) and the reduction of the wall thickness. By supplementing this, sufficient strength comparable to that of straight pipe sections can be obtained.

Furthermore, in the method for manufacturing the fluorescent lamp described above, after applying the protective film material suspension, first, the suspension at the bent part is forcibly heated and dried, and then the suspension on the entire inner surface of the other bulbs is dried. Therefore, along with adjusting the viscosity of the suspension, the thickness of the protective film on the inner surface of the bent portion can be adjusted as desired.

Next, the structure and characteristics of an actual fluorescent lamp were investigated. The results are shown in the table below.

[0021]

As is clear from Table 1, the inventive example has the advantage that there is almost no deterioration of the fluorescent film at the bent portion, high bulb strength, and almost no blackening due to mercury adhesion.

Note that the fluorescent lamp of the present invention is not limited to the above-mentioned U-shaped bulb, but may also have a WU-shaped bulb, for example.
In short, any glass bulb may be used as long as it has a glass bulb consisting of a plurality of straight tube sections connected one after another through bent sections. In addition, the protective film material is not limited to the above-mentioned γ-alumina, but may also be made of other materials such as α-alumina.
Alumina, titanium oxide, etc. may also be used. The thickness of the protective film at the bent portion may be thicker than at other valve portions and may be thick enough to obtain the above-mentioned effects.

Furthermore, in the manufacturing method of the present invention, the protective film material suspension is not limited to the above-mentioned one using water as a solvent, but may also be a suspension using an organic solvent and nitrocellulose, for example. Further, the means for forcibly heating and drying is not limited to the above-mentioned example. Furthermore, the protective film and the fluorescent film may be fired at the same time.

[0025]

As described above, the present invention relates to an improvement in a fluorescent lamp and a method for manufacturing the same. In the case where a fluorescent film is formed as the base of the film, the thickness of the protective film is thicker at the bent part than at other parts, so the fluorescent film at the bent part is not altered by sodium, which is a glass component, and the glass itself It has the advantage that it does not discolor due to ultraviolet rays and has a high bulb strength.

In addition, the second aspect of the present invention is to support a U-shaped glass bulb with a protective film material suspension coated on the inner surface with the bent portion facing upward, and to transfer the suspension on the inner surface of the bent portion to that of other parts of the bulb. First, the suspension is forcibly heated and dried, and then the suspension on the entire inner surface of the bulb is dried to form a protective film that serves as the base for the fluorescent film. It can be formed thickly and is particularly suitable for manufacturing methods using suspensions using solvents with poor evaporability, such as water.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of a fluorescent lamp according to the first invention.

FIG. 2 is an explanatory diagram illustrating an embodiment of the method for manufacturing a fluorescent lamp according to the second invention in the order of steps, in which (a) is an explanatory diagram after the bending process, and (b) is an explanatory diagram after applying the protective film material suspension. The latter explanatory diagram (c) is an explanatory diagram of a step of locally forcibly drying the protective film material suspension on the inner surface of the bent portion of the valve.

FIG. 3 is an explanatory diagram illustrating the steps following the steps of the present manufacturing method shown in FIG. 2 in order; (d) is an explanatory diagram of the step of drying the protective film material suspension on the entire inner surface of the valve; (e) is an explanatory diagram showing a state in which the protective film formation is completed, and (f) is an explanatory diagram showing a state in which a fluorescent film is formed on the protective film.

[Explanation of symbols]

(1)...Valve (11)...Bending part (2)…Protective film (21)...Protective film material suspension (3)...Fluorescent film (4)...Stem (6)...filament (81), (82)...nozzle

Claims (2)

[Claims] 1. A glass bulb consisting of a plurality of straight tube sections connected one after another through bent sections, and a protective film formed on the inner surface of the bulb to be thicker at the bent sections than at the straight tube sections. , and a fluorescent film formed on the protective film. [Claim 2] U whose inner surface is coated with a protective film material suspension
A letter-shaped glass bulb is supported with the bent part facing upward, and the suspension on the inner surface of the bent part is forcibly heated and dried before drying on the other parts of the bulb.Then, the suspension on the entire inner surface of the bulb is dried and a protective film is formed. 1. A method for manufacturing a fluorescent lamp, the method comprising: forming a fluorescent film as a base for a fluorescent film.