JPS61145278A - Phosphor - Google Patents

Abstract

PURPOSE:To enhance light emission efficiency, by incorporating a small amt. of fluorine in strontium magnesium borate phosphor activated with divalent europium. CONSTITUTION:0.1-1% fluorine is incorporated in strontium magnesium borate phosphor of the formula (wherein 0.07<=x<=0.3; 0.003<=y<=0.04; 1.7<=z<=2) activat ed with divalent europium to prepare the purpose phosphor. The phosphor exhibits high luminence in comparison with a fluosine-free phosphor. The phos phor is prepd. in the following method. Raw material powders such as SrCO3, MgCO3, H3BO3 and Eu2O3 powders are mixed in a predetermined proportion, packed in a crucible, subjected to primary baking, crushed, and then mixed with 0.1-1%, in terms of fluorine, fluoride such as MgF2 or NH4F. The resul tant mixture is subjected to reducing backing in a hydrogen-contg. gas stream, crushed and sieved.

Description

[Detailed description of the invention] A. Industrial application field The present invention relates to phosphors for use in fluorescent lamps.

In particular, the present invention relates to a phosphor for radiating ultraviolet rays that absorbs ultraviolet rays having wavelengths of 253 nm and 135 nm and emits (radiates) light at a wavelength of 353 nm in the near ultraviolet region.

B. Prior Art Fluorescent lamps coated with this type of fluorescent material have a wide range of uses, including for attracting insects, trapping insects, photochemical action, flaw detection of metals, and illuminating aircraft instruments.

europium-activated strontium fluoroarsenate phosphor, (
(Japanese Patent Publication No. 45-2293) and europium-activated strontium magnesium fluoroborate phosphor:
It is publicly known. (Japanese Patent Publication No. 49-3754, Japanese Patent Publication No. 5
5-16188.0) Furthermore, in this type of phosphor, a technique has been developed to improve the luminous efficiency by limiting the content of SrF to a narrow range. (Japanese Patent Publication No. 52-32815) The present invention was developed in a 1-1 manner to further improve the luminous efficiency of these conventional phosphors. By further limiting the content of fluorine I to within a specific range of 2il, luminous efficiency can be greatly improved compared to conventional ones.
-It's something new.

C1 Outline of the invention In a preliminary experiment, a part of Sr was converted to 1 m of alkaline earth gold (Ba, Ca, Mg).
It was found that it is effective at -1 Mp. Next, Mg
The optimal replacement ratio was determined.

First, regarding the concentration of the activator, in the case of a phosphor activated with E'u"', '-, the concentration of (Eu2+ The optimum value is around 0.01 to 0.02 gram atom.

The raw materials used are highly pure 5rcoI, MgCO2, H3.
BO]Eu2O, was used. Since it is difficult to obtain an M g COa K tweet with an accurate formula, a sample with an MgO content of 45.1 wt % was used after conducting a second analysis. Hereinafter, for example, when M g CO is written as 0.1 mole, the amount to be prepared is corrected (1.06 times) so that Mg is substantially 0.1 mole.

Regarding the amount of Mg to replace Sr, nine types were tested as shown in Table 1. In Table 1, units are expressed in moles for ease of understanding.

The manufacturing method of the phosphor is as follows: 5rco1. MgC0,.

The powders of i-+3BO3, Eu2O, and (7) are thoroughly mixed in a fluorine, then filled into an alumina crucible, and fired in air at 820° C. for 1 hour. by this,
Boric acid dehydrates and the carbonate decomposes, all becoming acidic compounds.

After thoroughly grinding this fired product in a bot mill,
In order to reduce ``- to (Eu2++), reduction firing is performed again at 870°C for 2 hours in a nitrogen gas flow containing 2 to 4% hydrogen.Next, this is ground in a ball mill and passed through a Tetron 200 mesh sieve. A sample can be obtained through the

For these samples, the relative value of the height of the spectrum peak (368 nm) was determined using a self-recording spectrophotometer. A comparison of the peak ratio of 1 and the luminance of the phosphor (output of Near Purple 1) is shown.

Chemical analysis of the composition of the produced phosphor revealed that the amount of metals (Sr, Mg, Eu) was the same as the amount of the compound. However, the amount of boron was detected as low r=Tlc in all cases. This may be due to some scattering during reduction firing, and the values may vary slightly, or this variation itself is not directly related to brightness.

As shown in Table 1, the optimum value for the Mg substitution amount is approximately 0.1 to 0.2 mol.

Next, a very small amount of rVIgF2 was added during the second firing (
4,)), an experiment was conducted to see if the effect of adding a small amount of MgF2 was high. Mg 2 F, is known to be effective as a flux when making conventional phosphors.

However, in that case, the amount used is only a few percent of that of the fluorescent material @11 (Z).

The present invention is based on the experiment described in (g) above, and shows that 9. (The luminance is extremely limited to less than 1% at a time.) By limiting the luminance to this range, I wondered if it would be possible to achieve a luminance that far exceeds conventional ones.

In this experiment, compared to the molar ratio of raw materials, S r CO:
+0.84. MgC0,,0,15,Eu2O,0,O
12,)-1,BO,,4. This mixture was first calcined at 820° (21 hours) to form a complete oxide as described above, and then MgF2 was added to the phosphor in an amount of 4% from 0% as shown in Table 2. 8 types of samples were made by adding and mixing them in 8 kinds of samples.
As a result, the phosphor was analyzed to confirm the remaining m, and as a result, culm loss of 20 to 30% occurred in each case.

As can be seen from Table 2 and FIG. 1, the residual amount of fluorine was improved by 6 to 11% in the vicinity of 0.1 to 1.0% in the case of the phosphor.

Regarding the highest value of Eu2→-, as in 1-,
Mg00.15 mol, MgF2)illJll @0-
6% CD In the most preferred composition, Eu2
O3 mole is 0°0025.0.005,0.01. 0
．． As shown in FIG. 2, it was confirmed that EuO had the highest brightness around 0.01 to 0.02.

Example 1 Strontium carbonate 124 grams (0.84 mol), M
13.4 grams (0.15 mol) of red sea bream carbonate with an O content of 45.1%, 1.76 grams of europium oxide
(0,005 mol) and 247.3 g (4 mol) of boric acid were mixed together in a blender, then filled into an alumina crucible, and then primary fired in air at 820°C for 1 hour. The produced oxide compound is ground in a ;j'' mill. 22 grams (1 wt%) of MgF is added to 200 grams of this high-L acid, and the mixture is milled again and mixed.

This mixture is subjected to reduction firing at 870° for 2 hours in an alumina crucible in a nitrogen stream containing 2 to 4% hydrogen. Next is Tetromba (200 meters of &B)
H and not completed Z).

The brightness of this phosphor is MgO, MI? The fluorine content of this phosphor was 0.46 wt%, showing a high efficiency of 116% compared to that without F2.

Example 2: Pond fluoride can be used in place of magnesium fluoride. Here, NH4F was used, and in this case, since the amount of volatilization was large, a rather large amount was added. Mixing of raw materials and primary firing were performed in the same manner as in Example 1. -Next Step 1: 15 g of NH4F was added and mixed to 200 g of the sucked and pulverized fired product, and the mixture was then reduced and fired in the same manner as in Example 1 and then passed through the rear surface.

The obtained phosphor had a fluorine content of o-11 wt%,
Compared to a phosphor containing fluorine and magnesium oxide without fζ, the brightness was 113%.

[Brief explanation of drawings]

FIG. 1 is an M property graph showing the brightness of the phosphor as a function of the content of F, and line 21 is a characteristic graph showing the brightness of the phosphor as a function of the EuO content. Applicant [] Shin Kagaku Kogyo Co., Ltd. p:: ,' (j (l-1) 10= He Fupope Weiai Job Opportunity

Claims (1)

[Claims] (1) In a strontium magnesium borate phosphor activated with divalent europium (Eu^2^+), its composition is (SrO)_1_-_X_-_yx_MgOy_EuO
z_B_2O_3 However, it is expressed by 0.07≦x≦0.30 0.003≦y≦0.04 1.7≦z<2.0 and contains 0.1 to 1% of fluorine (F) A phosphor characterized by: