JPS63200460A - Phosphor discharge lamp - Google Patents

Abstract

PURPOSE:To prevent a phosphor surface from being deteriorated so as to maintain high brightness for a long period by containing a surface treatment phosphor whose phosphor surface is possessed of surface treatment substance which contains compounds which contain phosphorus and at least one species of elements selected from a group of Zr, Ti, Hf, Ge, Si, Al, Y, La, and Sc. CONSTITUTION:Compounds, which contain phosphorus and at least one species of elements selected from a group of Zr, Ti, Hf, Ge, Al, Y, La, and Sc and which are contained in surface treatment substance, are as follows: (I) a mixture of oxide, which is made of at least one species of elements selected from a group of Zr, Ti, Hf, Ge, Si, Al, Y, La, and Sc, and oxide which is made of at least one species of phosphorus, (II) composite oxide composed of oxide, which is made of one species of elements selected from a group of Zr, Ti, Hf, GE, Si, Al, Y, La, and Sc, and oxide, which is made of at least one species of phosphorus, (III) phosphoric acid salt which is made of at least one species of elements selected from a group of Zr, Ti, Hf, Ge, Si, Al, Y, La, and Sc, and mixture containing at least two selected from (IV), (I) to (III). Thus, a phosphor discharge lamp with high initial brightness can be obtained and the brightness of this lamp is prevented from being deteriorated with the lapse of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a fluorescent discharge tube, and more particularly to a fluorescent discharge tube that uses a surface-treated phosphor and has high brightness and little reduction in brightness.

[Conventional technology]

BACKGROUND ART Conventionally, surface treatments have rarely been applied to phosphors used in fluorescent discharge tubes such as fluorescent lamps and discharge panels. This is because the fluorescent films of fluorescent discharge tubes were not required to have the same high performance as the fluorescent films of color cathode ray tubes, and the added value of fluorescent discharge tubes was not very high. .

However, the performance of the fluorescent film of conventional fluorescent discharge tubes has not always been fully satisfactory. For example, many fluorescent lamps currently produced are heated to high temperatures during lamp manufacture. Therefore, surface treatment substances, especially many surface treatment substances containing metal elements, end up diffusing into the surface layer of the phosphor. Also, in a fluorescent lamp, the phosphor is exposed to mercury vapor at the same time as it is excited. Therefore, the surface of the phosphor deteriorates due to mercury vapor. Diffusion of such a surface treatment substance into the surface layer of the phosphor and deterioration of the surface of the phosphor due to mercury vapor cause a decrease in the brightness of the surface layer of the phosphor. The performance of a fluorescent discharge tube that excites a phosphor with ultraviolet rays (ultraviolet rays have low energy) is significantly degraded by a decrease in the brightness of the surface layer of the phosphor.

Therefore, it is desired to provide a fluorescent discharge tube having a fluorescent film with less reduction in brightness.

Furthermore, in recent years, fluorescent lamps with high added value and high color rendering properties have become mainstream. In high color rendering fluorescent lamps,
Fluorescent materials using rare earth elements are often used. The price of phosphors using rare earth elements is more than ten times the price of conventional phosphors. For this reason, high color rendering fluorescent lamps using expensive fluorescent materials need to be able to be used for a longer period of time than conventional lamps.

Therefore, there is a desire for a technology that can prevent a decrease in brightness due to deterioration of the phosphor.

Incidentally, phosphors used in color cathode ray tubes and the like that are conventionally excited by electron beams are usually subjected to various surface treatments. This surface treatment involves coating each color of phosphor separately and finely on the face plate of a cathode ray tube (more specifically, it improves coating properties to form a good film and improves cross contrast with other colors. prevent color mixing),
Alternatively, this is done for the purpose of preventing deterioration of the phosphor due to electron beams. As substances used for the above-mentioned surface treatment, various oxides, silicate compounds, aluminate compounds, phosphate compounds, zinc hydroxide compounds, metal oxides, etc. are known (Japanese Patent Publication No. 44 -1
1769, JP-A-49-8478, JP-A-59-36182). In particular, silicon compounds have been widely used for a long time because of their ease of processing. Silicon dioxide, zinc silicate, aluminum silicate, and the like are known as such silicon compounds.

However, although these surface treatment agents are suitable for treating phosphors for color cathode ray tubes and the like, they are not necessarily satisfactory as treatment agents for phosphors for fluorescent discharge tubes.

[Problem that the invention seeks to solve]

An object of the present invention is to provide a fluorescent discharge tube using a surface-treated phosphor that can maintain high brightness for a long period of time by preventing deterioration of the surface of the phosphor.

[Means for solving problems]

The present invention uses Zr5Ti, Hf, Ge5Si, Aβ,
At least one selected from the group consisting of Y, La and Sc
The present invention relates to a fluorescent discharge tube having a phosphor film including a surface-treated phosphor having a surface treatment substance containing a compound containing a seed element and phosphorus on the surface of the phosphor.

The present invention will be described in further detail below.

In the present invention, lr contained in the surface treatment substance.

A compound containing phosphorus and at least one element selected from the group consisting of Ti, HfGeSSiSAn, Y, La, and Sc (hereinafter referred to as a phosphorus-containing compound),
(a) ZrS'rlSHfSGeSSISAIN
At least one selected from the group consisting of ylLa and Sc
A mixture of oxides of elemental species and at least one oxide of phosphorus, (r+)ZrSTiSHf, Ge5Si, ^
2. Composite oxide of at least one oxide of element selected from the group consisting of YSLa and Sc and at least one oxide of phosphorus, (c) Zr, Ti, Hf5GeSSi
, A ji! SY, a phosphate of at least one element selected from the group consisting of La and Sc, and (d) (
Examples include mixtures containing at least two of (a) to (8).

In the above (a), Zr5Ti, Hf5Ge, S
The oxide of at least one element selected from the group consisting of i, A I, Y, La and Sc includes 2rO,, Tie
□, HfO2, Gem2.5in2, A120a, Y2
It includes O3,1,, a20j, Sc, and C13, and may also be a mixture of these oxides. Further, examples of phosphorus oxides include P2O6 and the like.

As the composite oxide (0) above, for example, 2Aj2
20s.3PzOs can be mentioned.

Furthermore, the above (c) Zr5Ti, Hf, Ge5SiX
A1, Y: As the phosphate of at least one element selected from the group consisting of La and Sc, for example, 2Ge
Examples include O□.P2O3 and ZrO2.P2O2.

The phosphor is not particularly limited as long as it is a phosphor for a fluorescent discharge tube, and a commercially available product can be used as is.

Examples of phosphors include Ln2O3:Eu (Ln: y, GdS LaS
Lu) , L A P C (LnCeTb) PO
<(Ln:Lu, La, Gd5Y) ], apatite C (Ca, Sr) s (PO4) 3Cl:
εU], B A M (BaMg2A 1raO□q:
EIJ”J, CCB [Ca2BSD9CjI!:ε
U], CA T ((Ce, Tb) MgA j! zO
+s], Y S T (Y2S+Os:Tb, Ce),
MB○ [MgO: 2.5B203; Ce, Tb)
etc. can be mentioned. However, it is not limited to these.

The surface treatment substance has a concentration of about 5 Xl0-5 to phosphor.
5 X 10-"% by weight, preferably I X 10-5
It is preferable to include the phosphor in an amount of ˜3×10 −′% by weight from the viewpoint of not impairing the brightness of the phosphor and preventing a decrease in brightness.

Next, a method for manufacturing the surface-treated phosphor used in the fluorescent discharge tube of the present invention will be explained.

The surface-treated phosphor used in the fluorescent discharge tube of the present invention includes, for example, (a) lr, Ti, Hf, Ge, Si,
Oxide of at least one element selected from the group consisting of Al, YSLa and Sc, Zr5Ti, Hf,
At least one compound that becomes an oxide of at least one element selected from the group consisting of Ge5SiSA 1, YlLa, and Sc, or a mixture of the compound and the oxide of the above element, et al.) At least one oxide of phosphorus , at least one compound that becomes a phosphorus oxide at high temperature, or a mixture of the compound and the above-mentioned phosphorus oxide, and (C) a phosphor, and the resulting mixture is obtained by high temperature treatment. Can be done.

In this production method, the compound that becomes an oxide of phosphorus at high temperature is phosphoric acid CH3PO4:l or phosphoric acid am% 2'
7 Mu [(NH4)h H3-, POa (n=1:2
．． 3): is preferred, and ammonium phosphate is particularly preferred. Also, Zr, Ti, I(f
The oxide of an element selected from the group consisting of SGe, Si, Al, YSLa, and Sc preferably has a small particle size, and is particularly preferably in the form of a sol, since a phosphor film with high coverage can be created. .

The above components (a), (b) and (C) are generally mixed in a solvent at room temperature. Examples of the solvent include water, ethyl alcohol, and the like. The amount of solvent used is
(a), however, with respect to the total weight of components (C), 0
．． A suitable amount is 1 to 10% by weight.

A surface-treated phosphor can be obtained from a mixture of (a), (b) and (C) by subjecting it to high temperature treatment. The high temperature treatment is
It is suitably carried out at a temperature of about 50°C to about 1000°C, preferably about 50°C to about 900°C, under an air atmosphere. The air may be in a flowing state or in a stationary state. Note that it can also be carried out under an inert atmosphere other than air, such as N2.

Incidentally, the surface-treated phosphor obtained by high-temperature treatment can be pulverized and sieved if necessary to adjust the particle size to suit the intended use.

Among the surface-treated phosphors used in the fluorescent discharge tube of the present invention, when a phosphate such as Zr is used as the surface treatment agent, for example, a phosphor such as Zr is mixed with the phosphor, A surface-treated phosphor can be obtained by heat-treating the resulting mixture. The phosphor and the phosphor such as Zr can be mixed in a solvent such as water or ethyl alcohol. The amount of the solvent used is suitably 0.1 to 30% by weight based on the total weight of the phosphate such as Zr and the components of the phosphor. A mixture of a phosphor such as Zr and a phosphor can be heat-treated to obtain a surface-treated phosphor. The heat treatment is suitably carried out at a temperature of about 350°C to 1000°C, preferably about 50°C to about 900°C, under an air atmosphere. The air may be in a flowing state or in a stationary state. Note that it can also be carried out under an inert atmosphere other than air, such as N2.

Incidentally, the surface-treated phosphor obtained by heat treatment can be pulverized and sieved if necessary to adjust the particle size to suit the intended use.

The surface-treated phosphor thus obtained can be applied to the inner surface of a glass tube or the like by a conventional method and then dried (baked) to form the fluorescent discharge tube of the present invention.

More specifically, the surface-treated phosphor is dispersed in a solvent such as water to form a dispersion, and the dispersion is applied to the inner surface of a glass tube by a conventional method and baked. Next, a fluorescent discharge tube can be obtained by installing electrodes at both ends of the obtained glass tube, evacuating the tube, filling it with a small amount of mercury and a rare gas (argon, etc.), sealing it, and attaching a cap. The amount of surface-treated phosphor attached to the glass tube is 2 mg/ct in terms of phosphor weight.
l ~6mg/cff! , preferably 2.5 mg/
It is appropriate to set the crl to 4.5 mg/cm.

Further, in the fluorescent discharge tube of the present invention, an ultraviolet reflecting film can be provided between the fluorescent film and the glass tube.

Providing an ultraviolet reflection film is preferable because it increases the utilization rate of ultraviolet rays and increases the luminous flux. Examples of the ultraviolet reflection film include aluminum oxide, barium titanate, and calcium phosphate.

The thus obtained fluorescent discharge tube of the present invention has high brightness equal to or higher than that of conventional fluorescent discharge tubes, and can maintain brightness for a long period of time.

The present invention will be further explained below with reference to Examples.

Example I Y, O,:Eu phosphor (100 g) and 1tos sol (He1203 concentration 10%, alumina sol #100 (average particle size: 10 to 100 mμ), manufactured by Yasan Kagaku Kogyo) (0.1 g
) was added to 1500 g of water and stirred and dispersed to obtain a slurry. Add (NH4)28PO4 (0,016g) to the slurry and water (160g
) obtained by dissolving in (0.01% (NH,), HP○
4] Aqueous solution was added and stirred for 60 minutes. The resulting slurry was filtered, and the resulting solids were washed three times with 1000 g of water. The washed solid matter was dried in a dryer at 120° C. for 5 hours to obtain a surface-treated phosphor of the present invention. The phosphor was sieved through a 300 mesh sieve. The surface treatment agent is 0.
4A120. - It was 0.6P20S, and the amount of adhesion to the phosphor was 0.025%.

The sieved phosphor was coated twice on the inner surface of a pipe with a diameter of 20 mm, and fired to form a phosphor layer (coating amount: 4 IT 1 g/Cd), and a 40 watt red fluorescent lamp using the back gas as the filler gas was prepared. was created.

The initial luminous flux of the fluorescent lamp and the luminous flux after 100 hours of lighting were determined using an integrating sphere. The results are shown in Table 1 along with the deterioration rate.

Comparative Example 1 A fluorescent lamp (30W) was produced in the same manner as in Example 1 using a Y2O3:Eu phosphor that had not been surface-treated as a phosphor, and the initial luminous flux and luminous flux after 100 hours of lighting were determined. . The results are shown in Table 1.

Table 1 Examples 2 to 4 The same procedure as Example 1 was carried out except that the amount of surface treatment agent deposited was 0.1% (Example 2), 1% (Example 3), and 10% (Example 4). A fluorescent lamp was manufactured using the same method, and the luminous flux was measured. The results are shown in Table 2.

Comparative Example 2 A phosphor lamp was produced in the same manner as in Example 1, except that the surface treatment was performed without adding the (NH4)28P○4 aqueous solution to the phosphor slurry. The results are shown in Table 2.

Table 2 Examples 5 to 11, Comparative Examples 3 to 8 Surface-treated phosphors of the present invention were prepared using the phosphors and surface treatment agents shown in Table 3 according to the same procedure as in Example 1, and then A fluorescent lamp was produced using the obtained phosphor. A comparative fluorescent lamp was also prepared using a phosphor without surface treatment. Table 3 shows the deterioration rate and initial luminous flux of the fluorescent lamp.

Example 12, Comparative Example 9 After thoroughly grinding zirconium oxyphosphate ZrP2L in a mortar, 1g of it, Y, and 0. :Eu phosphor (100
50 mJ of water was added to g) and kneaded. Then,
This slurry was dried in a dryer at 120°C for 15 hours, and
The surface-treated phosphor of the present invention was obtained by passing through a 0.00 mesh sieve. Using the obtained phosphor, a fluorescent lamp was produced in the same manner as in Example 1, and the luminous flux was measured. The results are shown in Table 4. A fluorescent lamp of Comparative Example 9 was prepared using a Y,03:Eu phosphor without surface treatment as a phosphor, and the luminous flux was measured in the same manner.

Table 4 Example 13, Comparative Example 10 An ultraviolet reflection film was provided in a glass tube having a diameter of 20fflffl by applying aluminum oxide in advance using a conventional flow coating method or a known method such as JP-A-57-105269.

Next, the same surface-treated phosphor as in Example 2 was applied onto the film and baked to form a phosphor layer (approximately 3 mg/cffI coating amount), and a fluorescent lamp was produced in the same manner as in Example 1. . The luminous flux of the obtained fluorescent lamp was measured in the same manner as in Example 1.

In addition, a fluorescent lamp was prepared in the same manner as in Example 13 using a Y, O, :Eu phosphor without surface treatment, and compared (
Comparative Example 10).

The results are shown in Table 5.

Table 5 [Effects of the Invention] The fluorescent discharge tube of the present invention has high initial brightness and little decrease in brightness over time.

Procedural amendment band 1, Indication of case Patent Application No. 32946 of 1988 2, Title of invention Fluorescent discharge tube 3, Person making amendment Relationship to case Applicant name Kasei Optonics Co., Ltd. 4, Agent 5, Amendment Date of Order Voluntary (1) Amend the scope of claims as shown in the attached sheet.

(2) The following portions of the specification shall be corrected as follows.

Claim (1) Zr, Ti5Hf, Ge5Si, A1
, Y, LA, and Sc, and has a surface-treated phosphor containing a surface-treated substance containing a compound containing phosphorus and at least one element selected from the group consisting of , Y, LA, and Sc. discharge tube.

(2) 1rSTiSHf, Ge5SiS, a, Y
The compound containing phosphorus and at least one element selected from the group consisting of , La and Sc is Zr5Ti, Hf5G
Claim 1, which is a mixture or composite oxide of at least one oxide of an element selected from the group consisting of eSSi, YSLa, and Sc, and at least one oxide of phosphorus. Fluorescent discharge tube.

(3) lr, Ti, Hf, Ge, Si,
The compound containing phosphorus and at least one element selected from the group consisting of Ai, Y, La, and Sc contains Zr, Ti
, Hf, Ge5SiSA1, YSLa, and Sc.

(4) Claims (1) to (3) in which the surface-treated phosphor contains a surface-treated substance in a weight ratio of 5 x 10-5 to 5 x 10-2 to the phosphor. The fluorescent discharge tube according to any one of the above.

(5) The fluorescent discharge tube according to any one of claims (1) to (4), wherein the fluorescent discharge tube has an ultraviolet reflecting film between the fluorescent film and the glass tube. tube.

(6) The particle size of the surface treatment substance attached to the phosphor surface is 0.
．． 01 to 1.5 μm. The fluorescent discharge tube according to claim (1).

(7) The fluorescent discharge tube according to any one of claims (1) to (6), wherein the phosphor is a phosphor containing a rare earth element.

Claims (7)

[Claims] (1) Zr, Ti, Hf, Ge, Si, Al, Y, La
A fluorescent discharge tube having a phosphor film including a surface-treated phosphor having a surface-treated substance containing a compound containing phosphorus and at least one element selected from the group consisting of Sc and Sc on the surface of the phosphor. (2) Zr, Ti, Hf, Ge, Si, Al, Y, La
The compound containing phosphorus and at least one element selected from the group consisting of Zr, Ti, Hf, Ge, S
Claim (1) is a mixture or composite oxide of an oxide of at least one element selected from the group consisting of i, Al, Y, La, and Sc and at least one oxide of phosphorus. The fluorescent discharge tube described. (3) Zr, Ti, Hf, Ge, Si, Al, Y, La
The compound containing phosphorus and at least one element selected from the group consisting of Zr, Ti, Hf, Ge, S
The fluorescent discharge tube according to claim 1, which is a phosphate of at least one element selected from the group consisting of i, Al, Y, La, and Sc. (4) The surface-treated phosphor contains a surface-treated substance in an amount of 5 x 10^-^5 to 5 x 10^-^2% by weight based on the phosphor. The fluorescent discharge tube according to any one of item (3). (5) The fluorescent discharge tube according to any one of claims (1) to (4), wherein the fluorescent discharge tube has an ultraviolet reflecting film between the fluorescent film and the glass tube. tube. (6) The particle size of the surface treatment substance attached to the phosphor surface is 0.
．． 01 to 1.5 μm. The fluorescent discharge tube according to claim (1). (7) The fluorescent discharge tube according to any one of claims (1) to (6), wherein the phosphor is a phosphor containing a rare earth element.