JPS59128211A - Phosphor - Google Patents

Abstract

PURPOSE:To obtain a phosphor having high output for light emission represented by a specified formula by solubilizing boron oxide in a strontium aluminate phosphor contg. bivalent europium as an activator. CONSTITUTION:SrCO3, Sr(NO3)2, Al2O3, Al(OH)3, AlF3, H3BO3, NH4HB4O9. 3H2O, SrB4O7, etc. are mixed by prescribed amounts. The mixture is put in an alumina crucible or the like, and it is repeatedly calcined at about 800- 1,400 deg.C for a fixed time in an electric furnace. The final calcination is carried out in an atmosphere of a gaseous nitrogen hydrogen mixture passed through water. A phosphor emitting green light represented by a formula (Me1-nEun)O.x(Al1-mBm)2O3 (where Me is at least one among Ba, Sr and Ca, 0<=n<=1, 0.6<=x<=2, and 0<=m<=0.5) is obtd. The phosphor has the maximum emission wavelength at about 520nm.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a phosphor, and more particularly to a green-emitting phosphor.

Conventional structure and its problems Conventionally, as a green-emitting phosphor that emits light in the vicinity of 52 Q nm, there is a phosphor represented by Zn25io4:Mn, but this phosphor has poor lifetime characteristics. There are major obstacles to practical application. For example, when used in a low-pressure mercury vapor discharge lamp, it not only deteriorates due to ultraviolet rays but also adsorbs mercury, resulting in a large loss of light capacity of the low-pressure mercury vapor discharge lamp. In addition, divalent europium was used as an activator for a green-emitting phosphor (S
r, Eu) There is a fluorophore designated as AM204, and much research has been conducted on it. For example, Journal
of Electrochemical 5ociet
y (1971) Vol. 118, A 6 (p. 930) shows that the green light output can be increased by increasing the amount of aluminum in (Sr, Eu)A22o4 phosphor. . However, even if the amount of aluminum is increased to improve the luminous output, sufficient luminous efficiency for practical use cannot be obtained, and it has been difficult to apply this method to at least low-pressure steam discharge lamps.

OBJECTS OF THE INVENTION The present invention provides a green-emitting phosphor having a maximum emission wavelength near 62 Onm, which has a large emission output.

Structure of the Invention The present invention provides a general formula (Mel, -n, Eun)O-x(
A21. -mBm) 203 (however, O(n≦1.0.
A phosphor expressed by 6≦X≦3, o (m≦0.6, Me is at least one element selected from Ba, Sr, and Ca), and has a high luminous output. It's a Nishida thing.

Description of Examples
The headline is that a large luminous output can be obtained by incorporating boron oxide into a solid solution for a green phosphor that emits light in the nanometer range. FIG. 1 shows the relative luminous output with respect to the amount m of boron oxide dissolved in solid solution in the composition formula 4 (%). In this case, by dissolving boron oxide,
The maximum emission wavelength does not change, but if part or all of strontium is replaced with Ba and Ca, it shifts to the shorter wavelength side. Composition formula (Mel-n, Eun) ollx (
821-mBrr1)2o3 (where Me = Sr
, Ca, Ba), m is o (if m≦0.6, sufficient luminous output can be obtained, but ○, ○0
6 fists≦0, it is also good to have a range of 2. Also, n HO
(Eu can be dissolved in solid solution in the range of n≦1, but 0
．． The best range is 01≦n≦0.1. Sufficient light emitting output can be obtained for X in the range of 0.6≦X≦2, and especially in the range of 0.9≦X≦1.3, the light emitting output is not affected by changes in X.

To synthesize the phosphor of the present invention, S r CO3+S
r (No3) 2. AQ203. Aft (OH)
3. AQF3. H3BO3゜NH4HB409.3
Mix a predetermined amount of H20, 5rB407, etc., put this mixed part into an alumina or silica crucible, and heat it to a temperature of 8oO.
It is sufficient to repeat firing several times in an electric furnace for a certain period of time in the range of ~14001C. The firing atmosphere may be air or a reducing gas, but for the final firing, a mixed gas of nitrogen and hydrogen passed through water is used as the firing atmosphere.

The phosphor of the present invention is excited by ultraviolet rays, cathode rays, or X-rays and emits highly efficient green light, and can be used as a phosphor for mercury vapor discharge lamps such as fluorescent lamps and cathode ray tubes. can.

Next, the present invention will be explained in detail.

Example 1 SrCOs 5.519 grams A
f1203 3.973 Gram An'
3 0.040 grams H3BO3o
, 122 grams Eu2O30,346 grams A weighed mixture of the above compounds was placed in an alumina crucible and heated at a temperature of 1200°C in a nitrogen stream containing 8% hydrogen.
The phosphor obtained by firing for 2 hours, cooling and pulverizing the phosphor was
In a nitrogen stream containing 8% hydrogen passed through water at a temperature of 12oO℃
The chemical composition of this phosphor was (S"0.95 EuO,05)"("0
．． 95B0.05)203, and the luminescence output upon excitation with ultraviolet light at 254 nm was approximately 30% higher than that of the (SrO,950,05)o''8 to 203U phosphor that does not contain boron oxide. FIG. 2 shows the emission spectrum of the example phosphor upon excitation with 264 nm ultraviolet light.

Example 2 SrC○ 5.325 grams A
f! , 203 3.833 grams Ai
3 0.039 grams HBOO, 4
69 grams 3 Eu203 0.334 grams The above compounds were weighed and mixed, and the chemical composition of the phosphor was obtained by the same method as in Example 1. The luminous output was improved by about 20% over the boron oxide-free (Sro, 95EuO1o5)○°Aa203 phosphor.

Example 3 SrCO35,337 grams An O4,171 grams 3 ARP3 0.039 grams H3
BO30, 117 g Eu2O3o, 335 g The chemical composition formula of the phosphor obtained by weighing and mixing the above compounds in the same manner as in Example 1 is (SrO,96=EuO,06) "1.1 ( “0.
95B0.05)203, and the luminescence output upon excitation with 254 nm ultraviolet light was approximately 30% higher than that of the (SrO,9510,05)203u phosphor that does not contain boron oxide.

Example 4 The same mixture as in Example 1 above was placed in an aluminum crucible, fired in air at a temperature of 1300°C for 2 hours, cooled and crushed to obtain a phosphor in a nitrogen stream containing 8 parts hydrogen. temperature 120
The phosphor was baked at 0°C for 2 hours, cooled, and then passed through water at a temperature of 12°C in a nitrogen stream containing 8% hydrogen.
It was baked for 2 hours. The chemical composition of the phosphor thus obtained was the same as in Example 1, and the luminous output and spectral distribution were also the same.

As described in detail, the present invention provides an alkaline earth metal borosilicate aluminate fluorescent lamp using divalent europium as an activator, which has a predetermined chemical composition and has a maximum optical wavelength around 52 Onm. phosphors with excellent luminous output.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relative luminescence output with respect to solid-dissolved boron oxide in the phosphor of the present invention, and FIG. 2 is a diagram showing the emission spectral distribution in response to 254 nm ultraviolet excitation of Example 1 of the present invention. .

Claims (1)

[Claims] The general formula is (Mel, -n, Eury○・x(Af/, 1-
rnBm) 203 (however, o<n≦1.0.6≦X≦
2. A phosphor characterized in that okm≦0.6, Me being at least one element selected from Ba, Sr, and Ca.