JPS6169885A - Phosphor - Google Patents

Abstract

PURPOSE:To provide a bluish green phosphor having a high emission peak, prepd. by adding P2O5 as solid solution to a strontiun aluminate phosphor activated with Eu<2+>. CONSTITUTION:Phosphoric acid, etc. are added to a raw material consisting of (A) SrO or nitrate, carbonate, halide, etc. of Sr which are readily converted to SrO at a high temp., (B) Al2O3 or nitrate, hydroxide, halide, etc. of Al which are readily converted to Al2O3 at a high temp., (C) compd. such as ammonium (hydrogen) phosphate which is readily converted to P2O5 at a high temp., Sr3(PO4)2, AlPO4, etc. and (D) Eu2O3 or nitrate, carbonate, halide, etc. of Eu which are readily converted to Eu2O3. The mixt. is crushed and mixed thoroughly and is burned at 1,100-1,600 deg.C for several hours in a reducing gas atmos. to obtain a phosphor of the formula (where 6<=x<=8; 0<y<=0.4) activated with Eu<2+> and contg. P2O5 as solid solution.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to phosphors, and more particularly to 21111fi europium-activated strontium aluminate phosphors.

Conventional structure and its problems Concerning the conventional strontium aluminate phosphor activated with divalent europium, see ■.

S., patent 3,294.699 (1966)
It is described in.

S r A 1204: E u 2+ has been known for a long time and exhibits green light emission with a peak emission wavelength of 520 nm. On the other hand, M e A l 20 a ; E u
and MeA112o19; G, Blasse and A, Br11 for E-u2+.

philips Res+ Rapt-23 (1968
)201 has a research report, 5rA112019:Eu
It is known that the emission peak of is 395 nm.

In recent years, Japanese Unexamined Patent Application Publication No. 5
Publication No. 4-102073 and JP-A-55-11548
No. 9 was proposed, and a phosphor having an emission peak in the vicinity of 480 to 500 nm has been attracting attention. According to recent studies, for example, J, T, C.

Van Kemenade and G, P, F
, Hoeks Extendedabstract
&, 607, E, C, S - Spring Mee
S r 4 reported in ting(1ss3)
A l 1402. ;Eu2+ phosphor is a new type of aluminate with an emission peak wavelength of 490 nm. However, this real green phosphor activated with divalent europium has an insufficient emission peak height, and it has been desired to improve it.

OBJECTS OF THE INVENTION The present invention was made based on the above-mentioned circumstances, and it is an object of the present invention to provide a divalent 21ropium-activated aluminate phosphor with improved emission peak height.

Components of the Invention The inventors conducted various experiments on a strontium aluminate phosphor activated with divalent europium, and found that by further dissolving phosphorus oxide in this phosphor, the emission peak of the strontium aluminate phosphor could be improved. It has been found that the height can be further improved. That is, according to experiments conducted by the inventors, a strontium aluminate phosphor activated with divalent europium has a composition formula of 4(Sr, Eu)0.2A1.
2Q3・yp2o5, and the ranges of z and y in the above composition formula are 6≦I≦8. okuy≦0.
In case No. 4, a very favorable improvement in the emission peak height was observed. Furthermore, in the case of the phosphor according to the present invention, even in the region where the A12o3 amount However, even with these improved peak heights, it was confirmed that they could not exceed the emission peak height of the currently used 5r4A114025:Eu2+ fluorophore, and did not reach a practical level. Furthermore, the europium-added solution as an activator was found to have the effect of improving the above-mentioned emission peak height within the range of europium concentrations found in other commonly used phosphors.

Description of Examples The phosphor according to the present invention is obtained by the manufacturing method described below. First, as a raw material for the phosphor, (1) strontium oxide (S r O) or a compound that can be easily converted to SrO at high temperature, such as nitrate, carbonate, or halide.

(2) Aluminum oxide (A1203) or A12o easily at high temperatures such as nitrates, hydroxides, arsenides, halides, etc.
Compounds that can change into 3.

(3) ') Compounds that can be easily converted to P2O3 at high temperatures, such as ammonium hydrogen heptaoxide and ammonium phosphate, or phosphate compounds, such as strontium phosphate and aluminum phosphate.

(4) Europium oxide (Eu203) or compounds that can be easily converted to Eu2o3 at high temperatures, such as nitrates, carbonates, and halides.

is used. The above raw materials are weighed, and an appropriate amount of boric acid, boric anhydride, etc. are added and thoroughly ground and mixed using a ball mill. A phosphor is obtained by filling this into a quartz boat and firing it in a reducing atmosphere at a temperature within the range of 1100 to 1 eoOC for several hours.

Examples of the present invention will be described below.

Example 1 Strontium carbonate 246.85E aluminum oxide 3.07.69 europium oxide 9.1F boric anhydride
6.77 Ammonium hydrogen phosphate
6.7y The above raw materials were sufficiently pulverized and mixed in a ball mill, and fired in a reducing atmosphere at a temperature within the range of 1100 to 1600 C for several hours to obtain a phosphor. The compositional formula of the obtained phosphor is as follows.

' (””0.97 0.03)○−7AI O−o°
1P2o5' E u 2 3 Beak Masada, the target of ultraviolet threshold excitation of this phosphor, is a conventional phosphor that does not contain phosphorus oxide, 4 (S r o , s 7 0 , () 3) 0
This was 116% compared to the emission peak height of 7A l 203 ·Eu, and a clear improvement was observed.

Example 2 Strontium carbonate 245, 55' aluminum oxide 305.5y europium oxide 9.1F boric anhydride
6.61 Ammonium hydrogen phosphate
11.3y Using the above-mentioned conventional raw materials, a phosphor was obtained in the same manner as in Example 1. The compositional formula of the obtained phosphor is as follows.

4 (Sro, s-r”Euo, o3) O-7AI20
3-, 2P2o5 The peak height of this phosphor due to ultraviolet excitation was 111% compared to the emission peak height of a conventional phosphor that did not contain phosphorus oxide, which was a clear improvement. .

Example 3 Strontium carbonate 247.57 aluminum oxide 308.5y europium oxide 9.2y boric anhydride
6.7y ammonium hydrogen phosphate
2.91 Using the above raw materials, a phosphor was obtained in the same manner as in Sister Example 1. The compositional formula of the obtained phosphor is as follows.

4 (S ro, 9□” E uo, os ) O-
7A 1203 ” O-O5P2O5 The height of the luminescence peak of this phosphor upon excitation with ultraviolet light was 109% of that of the conventional fluorophore that did not contain acid fylline, and a clear improvement was observed. It was done.

Example 4 Strontium carbonate 259.8F aluminum oxide 300.6y europium oxide 9.61 boric anhydride
7.01 hydrogen phosphate a/monicum
5.8y A phosphor was obtained in the same manner as in Example 1 using the above raw materials. The compositional formula of the obtained phosphor is as follows.

4 (S ro , 97' Euc), o3) 0
・6-sA 1203・o, 1P205 The height of the emission peak of this phosphor due to ultraviolet excitation is the same as that of the conventional phosphor '(SrO,970,03)0°7A12o3Eu which does not contain phosphorus oxide. It was 110% compared to V, and a clear improvement was recognized.

Although it was observed that the boron compound used as a flux in the above actual case remained in the obtained phosphor, it did not have any particular negative effect on the luminescent properties of the phosphor, and if necessary, It can be removed by treatment such as washing with water.

DETAILED DESCRIPTION OF THE INVENTION As described above, the present invention provides a immersed blue-green phosphor with improved emission peak height by dissolving phosphorus oxide in a divalent europium activated stro/thium aluminate phosphor. This is something that can be provided.

Claims (1)

[Claims] A phosphor comprising a strontium aluminate phosphor activated with divalent europium and a solid solution of phosphorus oxide.