JP2001354956A - Aluminate phosphor and fluorescent lamp using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a stable aluminate phosphor capable of improving emission strength while maintaining good color purity. SOLUTION: The aluminate phosphor is represented by the formula: (Ce, Tb) (Mg1-a-bMaMnb)Al2zO2.5+3z.ySiO2 (wherein M is at least one element selected from Ba, Sr, and Ca; 0<a<=0.6; 0<a+b<1; 0<y<=1.0; and 4.5<=z<=10).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminate phosphor and a fluorescent lamp using the same.

[0002]

2. Description of the Related Art In recent years, a large-sized color image display device that can be used outdoors has been developed, and its use has been spreading. Japanese Patent Application Laid-Open Nos. 61-55851 and 2-129847 disclose a flat emission type variable color fluorescent lamp used for pixels and the like of such a large display. These variable-color fluorescent lamps are composed of one or more sets of picture elements that emit monochromatic light from phosphors emitting G (green), R (red), and B (blue), respectively, in order to form pixels of a large display. Have been. Among these phosphors, for example, terbium-activated cerium magnesium aluminate (hereinafter referred to as CAT) is used as the G component phosphor.

However, G component phosphors used in conventional flat light emitting fluorescent lamps for large displays include:
Since light emission by trivalent terbium is used as represented by CAT, as shown in FIG. 3, the color purity of green is not satisfactory, and the color reproduction range is narrower than that of a general color television. There was a problem, and improvement was desired. In FIG. 3, the R component phosphor is yttrium oxide (denoted as YOX in FIG. 3) activated with trivalent europium, and the B component phosphor is barium magnesium aluminate activated with divalent europium. (Also referred to as BAM).

For this reason, divalent manganese light emission is suitable as a phosphor having good color purity of green light emission, and divalent manganese-activated zinc silicate, divalent europium and divalent manganese are suitable for fluorescent lamps. Co-activated barium magnesium aluminate with manganese, divalent manganese activated cerium magnesium aluminate, and divalent manganese and 3
Cerium magnesium aluminate co-activated with monovalent terbium is known.

[0005] However, the above-described conventional flat light emitting fluorescent lamps for large displays are usually operated under high load, so that divalent manganese-activated zinc silicate and divalent europium and divalent manganese are used. In the case of co-activated barium magnesium aluminate, the luminance retention rate during the life is inferior,
In the case of divalent manganese-activated cerium magnesium aluminate and co-activated cerium magnesium aluminate of divalent manganese and trivalent terbium, the luminance retention rate during the lifetime is good, but the luminance itself is low. There was a disadvantage of being low.

Therefore, in order to improve the luminance of divalent manganese-activated cerium magnesium aluminate, an aluminate phosphor in which a part of magnesium is replaced with barium, strontium, calcium or zinc has been known (Patent). No. 2663306).

[0007] The aluminate phosphor disclosed in Japanese Patent No. 2663306 is used not only for a flat emission fluorescent lamp for a large display but also for a fluorescent lamp for general illumination.

[0008]

However, in such a conventional aluminate phosphor, even when a part of magnesium is replaced with a divalent metal element, these two aluminate phosphors may be used.
Divalent metal element is hardly dissolved in the phosphor crystal stably,
As a result, there is a problem that a sufficient light emission intensity cannot be obtained.

Further, in the conventional fluorescent lamp provided with a phosphor film made of an aluminate phosphor, as described above, the divalent metal element is hardly solid-dissolved in the phosphor crystal.
There is a problem that a sufficient luminous flux and a luminance maintenance rate during the life cannot be obtained.

The present invention has been made to solve such a problem, and is particularly suitable as a fluorescent material used for a flat light emitting fluorescent lamp for a large display, a fluorescent lamp for general lighting, and the like. It is an object of the present invention to provide a stable aluminate phosphor capable of improving emission intensity while maintaining color purity.

Further, the present invention can improve the luminous flux while maintaining good color purity, particularly in a flat light emitting fluorescent lamp for a large display, a fluorescent lamp for general lighting, and the like, and can improve the life span. And to provide a fluorescent lamp with less reduction in luminance.

[0012]

SUMMARY OF THE INVENTION According to the present invention, there is provided an aluminate fluorescent lamp.
The light body has the general formula: (Ce, Tb) (Mg_1-abM_aM
n _b) Al_2zO_{2.5 + 3z}・ YSiO_Two(However, M is Ba,
At least one element selected from Sr and Ca
0 <a ≦ 0.6, 0 <a + b <1, 0 <y ≦ 1.
0, 4.5 ≦ z ≦ 10)
Is what is done.

Thus, barium in which silicon dioxide is dissolved as a solid during phosphor synthesis and a part of magnesium is substituted,
At least one kind of divalent metal element (M) selected from strontium and calcium can be stably dissolved in the phosphor crystal, so that emission intensity is improved while maintaining good color purity. Can be.

Further, the fluorescent lamp of the present invention has a structure provided with a phosphor film containing the aluminate phosphor of the first aspect.

Thus, at least one kind of divalent metal element (M) selected from barium, strontium, and calcium partially substituted for magnesium is stably dissolved in the crystal of the phosphor. In addition, the luminous flux can be improved while maintaining good color purity, and a decrease in luminance can be suppressed throughout the life.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FCL according to an embodiment of the present invention
The 30/28 fluorescent lamp has a tube diameter of 29, as shown in FIG.
The glass bulb 1 is provided with stems 2 sealed at both ends of the glass bulb 1.

In FIG. 1, reference numeral 3 denotes a base.

A predetermined amount of mercury and a rare gas such as argon are sealed in the glass bulb 1, respectively. Further, a phosphor film 4 is formed on the inner surface of the glass bulb 1.

The stem 2 has a filament 6 laid between two lead wires 5 (only one is shown).

The phosphor film 4 is a G (green) component phosphor.
And the general formula: (Ce, Tb) (Mg _1-abM_aMn_b) A
l_2zO_{2.5 + 3z}・ YSiO_Two(However, M is Ba, Sr,
At least one element selected from Ca,
3. <a ≦ 0.6, 0 <a + b <1, 0 <y ≦ 1.0,
A number that satisfies the condition of 5 ≦ z ≦ 10).
An example in which a luminate phosphor is used as an R (red) component phosphor
For example, if YOX is used as a B (blue) component phosphor, for example, B
It consists of a mixed phosphor mixed with AM.

In the above general formula representing the aluminate phosphor as the G component phosphor, a is barium (Ba) which substitutes for part of magnesium (Mg), strontium (S
r) and the substitution amount of at least one divalent metal element (M) selected from calcium (Ca), and b represents the concentration of manganese (Mn) as an activator. The ranges are 0 <a ≦ 0.6, 0 <b <0.4 (0 <a +
b <1). Substitution amount a of divalent metal element (M)
Exceeds 0.6, the generation of regular phosphor crystals is inhibited, and the emission intensity is reduced. On the other hand, when the manganese concentration b is 0.4 or more, the emission intensity is reduced due to concentration quenching.

Y indicates the amount (mol ratio) of silicon dioxide (SiO ₂ ) to be added, and is defined in the range of 0 <y ≦ 1.0. In particular, y is preferably defined in the range of 0.01 ≦ y ≦ 0.5. Details of the reason will be described later.

Further, z is aluminum oxide (Al
_It indicates the composition ratio of ₂ O ₃ ) and is specified in the range of 4.5 ≦ z ≦ 10.

Next, a method for producing such an aluminate phosphor will be described.

The following materials are used as the phosphor material.

As the cerium source, at least one selected from cerium compounds such as cerium oxide and cerous nitrate is used.

As the terbium source, terbium oxide,
At least one selected from terbium compounds such as terbium nitrate is used.

As the magnesium source, at least one selected from magnesium compounds such as basic magnesium carbonate, magnesium hydroxide, and magnesium fluoride is used.

As the barium source, at least one selected from barium compounds such as barium carbonate and barium chloride is used.

As the strontium source, at least one selected from strontium compounds such as strontium carbonate and strontium chloride is used.

As a calcium source, calcium carbonate,
At least one selected from calcium compounds such as calcium chloride is used.

As the manganese source, at least one selected from manganese compounds such as manganese carbonate is used.

As the aluminum source, at least one selected from aluminum compounds such as aluminum oxide and aluminum hydroxide is used.

As the silicon source, at least one selected from silicon compounds such as silicon oxide is used.

A predetermined amount of these raw materials is weighed and thoroughly mixed. Put this mixture in a crucible and in air at 1200 ° C
Bake at １1600 ° C. for 2-4 hours. After the obtained fired product is pulverized, it is again put into a crucible and fired at 1400 ° C. to 1600 ° C. for another 2 to 4 hours in a reducing atmosphere of a mixed gas of nitrogen and hydrogen (nitrogen; 95%, hydrogen; 5%). I do. The burned material is subjected to a treatment such as grinding and washing with water to obtain the aluminate phosphor of the present invention which emits green light.

In the above method for producing an aluminate phosphor, fluorides such as aluminum fluoride, ammonium chloride, and magnesium fluoride, which are well known as a flux material used for the rare earth aluminate phosphor, or boric acid It was found that the addition of boron oxide or boron oxide was effective in improving the emission intensity as described below if it was in an appropriate amount.

The above general formula: (Ce, Tb) (M
_{g 1-ab M a Mn b} ) Al 2z O 2.5 + 3z · ySiO 2 ( however, M is at least one element selected from Ba, Sr, among Ca, 0 <a ≦ 0.6,0 < a + b <1,
According to the aluminate phosphor represented by 0 <y ≦ 1.0 and 4.5 ≦ z ≦ 10), part of magnesium is selected from barium, strontium, and calcium. When substituting with the divalent metal element (M), the solid solution of the divalent metal element (M) can be stabilized by dissolving silicon dioxide during the production of the phosphor. Emission intensity can be improved while maintaining color purity.

Further, according to the fluorescent lamp having the phosphor film containing the aluminate phosphor of the present invention, the divalent metal element (M) partially substituted for magnesium contains in the crystal of the phosphor. Since the solid solution is stable, the luminous flux can be improved while maintaining good color purity, and a decrease in luminance can be suppressed throughout the life.

An experimental example for confirming the operation and effect of the present invention will be described below.

Example 1 The composition formula of the aluminate phosphor of Example 1 is Ce _0.6 Tb _0.4 (Mg _0.68 Ba _0.3 Mn).
_0.02 ) Al ₁₁ O ₁₉ · 0.5 SiO ₂ . The materials of the aluminate phosphor of Example 1 are as follows. CeO ₂ 0.60 mol Tb ₄ O ₇ 0.10 mol Mg (OH) ₂ 0.68 mol BaCO ₃ 0.30 mol Al ₂ O ₃ 5.50 mol SiO ₂ 0.50 mol MnCO ₃ 0.02 mol The aluminate of Example 1 luminous intensity by 254nm ultraviolet excitation phosphors, aluminate contains no silicon dioxide phosphor _{Ce 0.6 Tb 0.4 (Mg 0.68 Ba} 0. 3 Mn
_0.02 ) It was found to be 13% higher than the emission intensity of Al ₁₁ O ₁₉ (hereinafter referred to as Comparative Example 1).

The FCL 30/28 fluorescent lamp manufactured by using the aluminate phosphor of Example 1 was used.
The luminous flux after the elapse of the time lighting was 10% of the FCL30 / 28 fluorescent lamp manufactured using the aluminate phosphor of Comparative Example 1.
It was found that the luminous flux was improved by 5% as compared with the luminous flux after lighting for 0 hours.

Further, the luminance retention rate of the FCL30 / 28 fluorescent lamp using the aluminate phosphor of Example 1 after the lapse of 2000 hours of lighting was determined by the FCL30 / 28 fluorescence using the aluminate phosphor of Comparative Example 1. It was found that the luminance was improved by 1% as compared with the luminance maintenance ratio after the lamp was turned on for 2000 hours.

As described above, in the fluorescent lamp using the aluminate phosphor of Example 1, the characteristics of the luminous flux and the luminance maintenance ratio can be clearly improved.

Example 2 The composition formula of the aluminate phosphor of Example 2 is Ce _0.8 Tb _0.2 (Mg _0.85 Sr _0.05 Mn).
_0.1 ) Al ₁₆ O _26.5 · 0.05 SiO ₂ . The materials of the aluminate phosphor of Example 2 are as follows. _{Ce 2 (NO 3) 3 ·} 6H 2 O 0.40mol Tb 4 O 7 0.05mol MgO 0.85mol SrCO 3 0.05mol Al 2 O 3 8.00mol SiO 2 0.05mol MnF 2 0.10mol this embodiment luminous intensity by 254nm UV excitation aluminate phosphor of 2, aluminate contains no silicon dioxide phosphor _{Ce 0.8 Tb 0.2 (Mg 0.85 Sr} 0. 05 Mn
_0.1 ) It was found to be 11% higher than the emission intensity of Al ₁₆ O _26.5 (hereinafter referred to as Comparative Example 2).

Further, 100% of the FCL30 / 28 fluorescent lamp manufactured using the aluminate phosphor of Example 2 was used.
The luminous flux after the elapse of the time lighting was 10% of the FCL30 / 28 fluorescent lamp manufactured using the aluminate phosphor of Comparative Example 2.
It was found that the luminous flux was improved by 8% as compared with the luminous flux after 0 hours of lighting.

Further, the luminance retention rate of the FCL30 / 28 fluorescent lamp using the aluminate phosphor of Example 2 after the lapse of 2,000 hours of lighting was determined by the FCL30 / 28 fluorescent lamp using the aluminate phosphor of Comparative Example 2. It was found that the luminance was improved by 1% as compared with the luminance maintenance ratio after the lamp was turned on for 2000 hours.

As described above, in the fluorescent lamp using the aluminate phosphor of the second embodiment, the characteristics of the luminous flux and the luminance maintenance ratio can be clearly improved.

Example 3 Aluminate Fluorescence of Example 3
The composition formula of the body is Ce_0.96Tb_0.04(Mg_0.35Ca_{0. Five}Mn
_0.15) Al₁₄O_23.5・ 0.03SiO_TwoIt is. Also,
The material of the aluminate phosphor of Example 3 is shown below.
It is as follows. Ce_Two(NO_Three)_Three・ 6H_TwoO 0.48mol Tb_FourO₇ 0.01 mol MgO 0.35 mol CaCO_Three 0.50mol Al_TwoO_Three 7.00mol SiO_Two 0.03mol MnF_Two 0.15 mol 254 nm ultraviolet light of the aluminate phosphor of Example 3
The emission intensity by excitation is
Phosphate phosphor Ce_0.96Tb_0.04(Mg_0.35Ca _0.5Mn
_0.15) Al₁₄O_23.5(Hereinafter referred to as Comparative Example 3)
It was found to be improved by 4% compared to the degree.

Further, 100% of the FCL30 / 28 fluorescent lamp manufactured using the aluminate phosphor of Example 3 was used.
The luminous flux after the elapse of the time lighting was 10% of the FCL30 / 28 fluorescent lamp manufactured using the aluminate phosphor of Comparative Example 3.
It was found that the luminous flux was improved by 3% as compared with the luminous flux after lighting for 0 hours.

Further, the luminance retention rate of the FCL30 / 28 fluorescent lamp using the aluminate phosphor of Example 3 after the lapse of 2,000 hours of lighting was determined by the FCL30 / 28 using the aluminate phosphor of Comparative Example 3. It was found that the luminance was improved by 1% as compared with the luminance maintenance rate after the lapse of 2000 hours of lighting of the fluorescent lamp.

As described above, in the fluorescent lamp using the aluminate phosphor of the third embodiment, the characteristics of the luminous flux and the luminance maintenance ratio can be clearly improved.

Example 4 Aluminate Fluorescence of Example 4
The composition formula of the body is Ce_0.64Tb_0.36(Mg_0.94Ba_{0. 01}Mn
_0.05) Al₁₁O₁₉・ 0.003SiO_TwoIt is. Also,
The material of the aluminate phosphor of Example 4 is shown below.
It is as follows. CeO_Two 0.64mol Tb_FourO₇ 0.09mol MgO 0.94mol BaCO_Three 0.01mol Al_TwoO_Three 5.50mol SiO_Two 0.003mol MnF_Two 0.05 mol UV light of the aluminate phosphor of Example 4 at 254 nm
The emission intensity by excitation is
Phosphate phosphor Ce_0.64Tb_0.36(Mg_0.94Ba _0.01Mn
_0.05) Al₁₁O₁₉(Hereinafter referred to as Comparative Example 4)
It was found to be improved by 3% as compared with.

The FCL 30/28 fluorescent lamp manufactured by using the aluminate phosphor of Example 4 is 100%.
The luminous flux after the elapse of the time lighting was 10% of the FCL30 / 28 fluorescent lamp manufactured using the aluminate phosphor of Comparative Example 4.
It was found that the luminous flux was improved by 2% as compared to the luminous flux after the lighting for 0 hours.

Further, the luminance retention rate of the FCL30 / 28 fluorescent lamp using the aluminate phosphor of Example 4 after the lapse of 2000 hours of lighting was determined by the FCL30 / 28 fluorescent lamp using the aluminate phosphor of Comparative Example 4. It was found that the luminance was improved by 1% as compared with the luminance maintenance ratio after the lamp was turned on for 2000 hours.

As described above, in the fluorescent lamp using the aluminate phosphor of the fourth embodiment, the characteristics of the luminous flux and the luminance maintenance ratio can be clearly improved.

Here, as the aluminate phosphor according to the present invention, for example, (Ce _0.6 Tb _0.4 ) (Mg _0.68 Zn
_0.3 Mn _0.02 ) Al ₁₁ O ₁₉ .ySiO _{2 In} the phosphor (Ce) containing no silicon dioxide, that is, y = 0, by varying the addition amount y (mol ratio) of silicon dioxide.
_0.6 Tb _0.4 ) (Mg _0.68 Zn _0.3 Mn _0.02 ) Al ₁₁ O ₁₉
When the relative light emission intensity (%) with respect to the light emission intensity was examined, the results shown in Table 1 were obtained.

In Table 1, “○” indicates good,
“X” indicates a defect.

[0058]

[Table 1]

As shown in Table 1, when the addition amount y of silicon dioxide exceeds 0, for example, at 0.001, the relative emission intensity was 100.1%. On the other hand, when the addition amount y of silicon dioxide exceeds 1.0, for example, when the addition amount was 1.001, the relative emission intensity was 99.5%. Therefore,
The emission intensity can be improved by setting the amount y of silicon dioxide to be more than 0 and not more than 1.0.

In particular, the addition amount y of silicon dioxide is
It is preferable that the light emission intensity is defined in the range of 0.01 or more and 0.5 or less, which can further improve the light emission intensity.

As an example of the aluminate phosphor according to the present invention, (Ce _0.6 Tb _0.4 ) (Mg _0.68 Zn _0.3 M
n _0.02 ) 2 of Al ₁₁ O ₁₉ .0.1 SiO ₂ (Example 1)
FIG. 2 shows an emission spectrum by excitation with a 54 nm ultraviolet ray. However, the vertical axis in FIG. 2 is the peak emission intensity (wavelength 54
The relative luminescence intensity (%) is shown with 4 nm) as 100.

FIG. 3 shows, for example, (Ce _0.6 Tb _0.4 )
(Mg _0.68 Zn _0.3 Mn _0.02 ) Al ₁₁ O ₁₉ · 0.5Si
₂ of the aluminate phosphor according to the present invention represented by O 2
The chromaticity point P of light emission by excitation of 54 nm ultraviolet light is determined by CA used in a conventional flat fluorescent lamp for a large display.
These are shown on the x and y coordinates together with those for T, YOX and BAM.

In FIG. 3, G, R, and B are chromaticity coordinates of the NTSC system used in a general color television.

As is clear from FIG. 3, the color purity of the aluminate phosphor according to the present invention is good, and by combining it with conventional YOX and BAM, for example, the same color reproduction as that of a general color television can be obtained. It can be seen that it can be realized.

In the above embodiment, the case where the aluminate phosphor of the present invention is used for an FCL30 / 28 fluorescent lamp has been described. However, the aluminate phosphor of the present invention is not limited to this, and may be, for example, a straight tube. The same effects as described above can be obtained by using the present invention in a fluorescent lamp for general illumination such as a compact fluorescent lamp or a compact fluorescent lamp, or a flat emission fluorescent lamp for a large display.

In the above embodiment, the case where the phosphor film 4 containing the aluminate phosphor of the present invention is directly formed on the glass bulb 1 has been described. The same effect as described above can be obtained even if a protective film is formed on the substrate.

[0067]

As described above, the present invention can provide a stable aluminate phosphor capable of improving emission intensity while maintaining good color purity.

Further, the present invention can provide a fluorescent lamp which can improve the luminous flux while maintaining good color purity and has a small decrease in luminance throughout its life.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of an FCL30 / 28 fluorescent lamp according to an embodiment of the present invention.

FIG. 2 shows an emission spectrum of an aluminate phosphor according to one embodiment of the present invention.

FIG. 3 is a diagram showing the chromaticity of the aluminate phosphor shown in Example 1 of the present invention on an x, y chromaticity diagram.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass bulb 2 Stem 3 Base 4 Phosphor film 5 Lead wire 6 Filament

Continued on the front page F term (reference) 4H001 CA04 CA07 XA08 XA12 XA13 XA14 XA20 XA38 XA56 XA58 YA25 YA65 5C043 AA02 AA20 CC09 DD28 EB02

Claims (2)

[Claims] 1. The general formula: (Ce, Tb) (Mg _1-ab M _a
Mn _b ) Al _2z O _{2.5 + 3 z} · ySiO ₂ (where M is B
at least one element selected from a, Sr, and Ca, 0 <a ≦ 0.6, 0 <a + b <1, 0 <y ≦
1.0, 4.5 ≦ z ≦ 10)
An aluminate phosphor represented by the formula: 2. A fluorescent lamp comprising a phosphor film containing the aluminate phosphor according to claim 1.