JPH0196283A - Fluorescent substance - Google Patents

Abstract

PURPOSE:To obtain a fluorescent substance consisting of a specific aluminate, activated with bivalent europium and emitting blue light with hardly any change in color of emitted light during lighting a lamp. CONSTITUTION:A fluorescent substance obtained by using a compound expressed by the formula (0.1<=x<=0.5; 0.1<=y<=0.8; 0.03<=z<=0.10; x+y+z=1; 1.5<=a<=4.5; M is Ti, Zr or Hf; 0<b<=0.05).

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (INDUSTRIAL APPLICATION) The present invention relates to divalent europium-activated blue-emitting aluminate phosphors.

(Prior art) In recent years, fluorescent lamps for general lighting have been required to have high color rendering and high output, and one way to meet these demands is to use blue, green, and red emitting fluorescent lamps that have a relatively narrow band emission spectrum distribution. Three-wavelength fluorescent lamps are being researched and developed that use a mixture of substances in appropriate proportions. In this type of fluorescent lamp, each phosphor emits a significantly different color, which causes a color shift phenomenon caused by the lamp. Furthermore, aluminate-based phosphors are used as the blue light-emitting component of recent three-wavelength fluorescent lamps. The europium-activated aluminate phosphor ((Ba+Eu)MgzAI2isOzt (Japanese Patent Publication No. 52-22836)), which is a well-known blue-emitting phosphor, and the same europium-activated aluminate phosphor ((Ba,Eu) )0-x'P4
go-yGd, 03・z A(1,0, (Special Public Service 1986-
No. 25468) and No. 25468) and the like have room for improvement in terms of the magnitude of change in the color of emitted light from the phosphor during lamp lighting.

(Problems to be Solved by the Invention) As mentioned above, it is desired that a three-wavelength fluorescent lamp has a high lamp emission output and a small color shift phenomenon, but it is desirable to minimize this color shift phenomenon. For this purpose, it is desirable to have a phosphor with a small change in luminescent color during lamp lighting.

The present invention was made to solve the above problems, and an object of the present invention is to provide a blue-emitting aluminate phosphor that exhibits high luminescence under 254 nm mercury emission line excitation and exhibits little change in luminescent color during lamp lighting. do.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a blue-emitting aluminate phosphor in -format (
BaxMgyEuz)0・aAj! ,0.・It is characterized by being expressed as bMO. However, 0.1
≦X≦0.5.0.1≦y≦0.8.0.03≦z≦0
．． 10. x+y+z=1.1.5=≦a≦4.5.
M is at least one selected from Ti, Zr, and Hf, and o<b≦0.05.

In the general formula, a more preferably has a value in the range of 2.0≦a≦3.0.

(Function) Table 1 is for explaining the effects of the present invention. When comparing the phosphor of the present invention and the conventional blue-emitting aluminate phosphor, the general formula (BaxMg
The phosphor represented by yEuz)O-aAet al.03.bMO2 showed a smaller difference in emission color between the phosphors removed from the glass bulb after 0 hours and 1000 hours after the production of the fluorescent lamp, and an improvement was observed. Furthermore, the index a is 2.0≦a≦3.
A more favorable improvement was observed in the case of 0.

(Example) Phosphor (BaxMgyEuz) (l aAl
2O3.bMO2 can be synthesized as follows.

The phosphor raw material contains at least one compound selected from the group of barium compounds such as barium oxide, barium hydroxide, and barium carbonate as a barium source.

At least one compound selected from the magnesium compound group such as magnesium oxide, magnesium hydroxide, and basic magnesium carbonate as a magnesium source, and at least one compound selected from the europium compound group such as europium oxide and cottonized europium as the europium source. at least one aluminum oxide as an aluminum source;
At least one compound selected from the group of aluminum compounds such as aluminum hydroxide, and titanium oxide,
At least one of zirconium oxide and hafnium oxide is used. A predetermined amount of these raw materials is weighed and the raw material mixture is thoroughly mixed. The mixture is placed in a heat-resistant container such as a crucible and fired in air at 1200°C to 1600°C for 3 to 4 hours. The obtained fired product is subjected to treatments such as pulverization and washing with water, and after drying, it is placed in a crucible or the like again and fired at 1400° C. to 1600° C. for 3 to 4 hours in a reducing atmosphere. The blue-emitting aluminate phosphor of the present invention can be obtained by subjecting the fired product to treatments such as pulverization and washing with water.

(Example-1) BaCO, 0.45 mol BgO, 50 mol Eu20. 0.025 mol AQ, 0
．． 2.00 molTie2
0.01 mol of the above raw materials were thoroughly mixed and calcined in air at 1400°C for 4 hours. The obtained fired product was crushed, washed with water, dried, and then fired at 1600° C. for 4 hours in a reducing atmosphere to obtain a phosphor after being crushed, washed with water, and dried. The composition of the obtained phosphor was (Bao, 4sMgo, 5Euo,
as) 0 ・2AQ203'0.01T102.

This phosphor is applied to the inner surface of the glass bulb and FL20SS/
A 1g fluorescent lamp was prepared, and the phosphor peeled from this lamp was excited with 254 mercury emission lines, and the emission color was x = 0.14.
6. y = 0.063. After 1000 hours it is x
=0.147. When y = 0.065, the magnitude of the change in luminescent color is Δx = 0.001. Δy=o, o02.

This is a comparative example (Bao, 5Euo, x) MgzA
ΔX of ffxsOzt=0.008. Δy=o, o07
smaller.

(Example-2) BaO0, 45 mol Bg(OH), 0.50 molEu, 0.
0.025 molAQ(On)35-Omo
l Tie2 0.01 mol The above raw material is treated in the same manner as in Example-1. The composition of the obtained phosphor is (Bao, *Jga, 5Eua, as)0' 2-5
Aj2.03・0.01TiO, and the magnitude of the change in the emission color of this phosphor is Δx=0.002. Δy=0.
It is 003. This is smaller than the comparative example.

(Example-3) BaCO30, 45 mol MgC030, 50 mol Eu, 0. 0.05 molAQ2033.
0 mol Tie20.01 mol The above raw materials are treated in the same manner as in Example-1. The composition of the obtained phosphor is (Bao, n!Mgo, Juo, as)O”
3-OAQ, 03·0.01TiO□. The magnitude of the change in the luminescent color of this phosphor is Δx=o, oo1. Δy
-=0.002. This is smaller than the comparative example.

Table 1 shows the results of Examples 1 to 3, the results of Examples 4 to 18 synthesized by the same method, and the results of Comparative Examples.

(Left below) In Table 1 Fluorescent material is applied to the inner surface of the glass bulb, and FL20SS
/18 After manufacturing a fluorescent lamp, peel off the phosphor from the lamp after 0 hours of production, and emit color when the phosphor is made to emit light with 254no+ excitation. After lighting one fluorescent lamp for 1000 hours, remove the phosphor from the lamp in the same way. Emission color when peeled off and excited at 254 nm [Effects of the Invention] As explained above, according to the present invention, a phosphor whose emission color changes little during lamp operation can be obtained.

Agent: Patent Attorney Noriyuki Chika Same Kikuo Takehana

Claims (2)

[Claims] (1) General formula (Ba_xMg_yEu_z)O・aAl
_2O_3・bMO_2 (where x is 0.1≦x≦0.
5, y is 0.1≦y≦0.8, z is 0.03≦z≦0.
10, x+y+z=1, a is 1.5=≦a≦4.5, M
is at least one selected from Ti, Zr, and Hf,
b is a value in the range of 0<b≦0.05). (2) The phosphor according to claim 1, wherein a in the general formula has a value in the range of 2.0≦a≦3.0.