JPS60115124A - Manufacture of fluorescent lamp - Google Patents

Abstract

PURPOSE:To inhibit drop in flux during use by coating the surface of the fluorescent material particles with silicon oxide. CONSTITUTION:A solution containing organic silicon is mixed with a fluorescent material or with a fluorescent material suspension. The mixture is heat-treated to coat the surface of the fluorescent material particles with silicon oxide. A fluorescent lamp is manufactured by applying the fluorescent material on the inner surface of a tube. According to this method, silicon oxide film is formed on the surface of the particle stably, and furthermore, a fluorescent lamp characterized by greatly inhibited flux drop is obtained.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method of manufacturing a fluorescent lamp.

Conventional Structures and Problems Generally, during the life of a phosphor coated on the inner surface of a fluorescent lamp tube, its brightness is significantly reduced due to bombardment of ions generated by discharge. This is explained by J. Elec.
trochem Sac, 107 (3) 210~
216 (1960), L Harriso
nya, J, Electroahem, Soc, 1
30 (2) 426-431 (1eas), it was reported by Will Lehmann et al. It is known that it has the effect of suppressing the decrease in luminous flux inside.

However, since 5b205 itself is a material used as an activator, when added to a phosphor, it often impairs the original light emission. Therefore, JP-A-61-134393 discloses a method of coating the surfaces of phosphor particles using silicon oxide or magnesium oxide instead of 5b2o3. However, even with this method, it is difficult to stably form a uniform film on the surface of the phosphor particles, and special equipment such as a reaction tube for oxidizing chloride to form an oxide is required. Therefore, when making a fluorescent lamp using these fluorescent materials, problems arise such as unstable quality and increased manufacturing cost of the fluorescent rung.

Purpose of the Invention The present invention has been made in view of the above circumstances, and it is an object of the present invention to coat the surface of phosphor particles with silicon oxide using a simple method, and to stably form this silicon oxide film. The present invention provides a method for manufacturing a fluorescent lamp that suppresses a decrease in luminous flux during its life.

Structure of the Invention The present invention involves mixing a solution containing organosilicon with a phosphor or a phosphor suspension, then heat-treating the surface of the phosphor particles with silicon oxide, and applying the phosphor to the inner surface of a tube. The present invention features a method of manufacturing a fluorescent lamp.

DESCRIPTION OF EMBODIMENTS As is well known, organosilicon such as ethyl silicate becomes silicon oxide through hydrolysis and is used to form a thin film of silicon oxide on the surface of a substrate such as glass. Therefore, by utilizing this chemical reaction and forming a silicon oxide coating film on the surface of the phosphor particles, an ion bombardment resistant phosphor can be obtained.

Next, the present invention will be explained in detail.

Example 1 200q of strontium-magnesium-aluminate phosphor activated with divalent europium is dispersed in 4 ounces of ethyl alcohol and thoroughly stirred. after that,
40 mJ of ethyl silica) ((C2H50)4
Si) was added and stirred thoroughly again to form a 0.2 mol percent ammonium carbonate [(NH4)2C03] solution 1.
Add 00m2 and continue stirring. After stirring for about 30 minutes,
After the above solution is left to precipitate sufficiently, the upper liquid is removed, filtered, and dried at about 7 o'clock.The dried phosphor is baked at 900°C for about 1 hour in a slightly reducing atmosphere. do.

This phosphor was adhered to the inner surface of a glass tube, and a straight tube 40W fluorescent lamp (outer diameter 321 m
) was produced. The luminous flux deterioration rate of this lamp after 100 Q hours was 92%, which was achieved by the method of the present invention.

Example 2 A fluorescent lamp was manufactured in the same manner as in Example 1 except for the step of adding ammonium carbonate. The luminous flux reduction rate of this lamp after 1000 hours is 93%, and compared to a fluorescent lamp using a phosphor not treated by the method of the present invention, the luminous flux reduction during the life of this lamp is suppressed by approximately 5%. was completed.

Example 3 Using strontium-calcium-barium-chlorophosphate-blue phosphor activated with divalent europium, the process of firing in a weakly reducing atmosphere at 90° C. for about 1 hour in Example 1 was repeated. A fluorescent lamp was manufactured in the same manner as in Example 1, except that the firing process was performed at 650° C. for about 1 hour in a weakly reducing atmosphere. The luminous flux deterioration rate of this lamp after 1000 hours is 94%, which suppresses the luminous flux decline during its life by about 3% compared to a fluorescent lamp using a phosphor not treated by the method of the present invention. I was able to do that.

Example 4 A fluorescent lamp was manufactured in the same manner as in Example 2 using a zinc silicate green phosphor activated with divalent manganese. The luminous flux deterioration rate of this lamp in 1000 hours is 90chi,
Compared to a fluorescent lamp using a phosphor that has not been treated by the method of the present invention, the decrease in luminous flux during the lifetime could be suppressed by about 1.0%.

Incidentally, in the present invention, similar improvement effects as in the above-mentioned embodiments could be obtained with respect to fluorescent lamps using other fluorescent materials other than the above-mentioned embodiments, which have a relatively large decrease in luminance during their lifetime.

In addition, in the above example, ethyl silicate was used, but
Of course, other organosilicon compounds may also be used.

DETAILED DESCRIPTION OF THE INVENTION As described above, the present invention involves mixing a solution containing an organosilicon with a phosphor or a phosphor suspension, and then heat-treating the surface of the phosphor particles to coat the phosphor particles with silicon oxide. Provided is a method for manufacturing a fluorescent lamp, which can form a silicon oxide film in a simple manner and stably by depositing a luminous substance on the inner surface of the tube, thereby greatly suppressing a decrease in luminous flux during its life. 8.

Claims (1)

[Claims] It is characterized by mixing a solution containing organosilicon with a phosphor or a phosphor suspension, then heat-treating the surface of the phosphor particles with silicon oxide, and depositing this phosphor on the inner surface of the tube. A method for manufacturing a fluorescent lamp.