KR960000869B1 - Fluorescent material and its preparation method of the same - Google Patents

Abstract

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Description

Phosphor and its manufacturing method

The present invention relates to an alkaline earth metal haloborate phosphor containing a divalent flow path product as an activator. More specifically, the present invention relates to a divalent europium-activated alkaline earth metal haloborate phosphor containing lithium as a scavenger.

Conventional haloborate-based phosphors are divalent euro product activating aralito and haloborate-based phosphors [(M, Eu2 +) 2B5O8 × (wherein M is at least one of calcium, strontium and barium, and X is at least one of chlorine, bromine and iodine) One.)]

Journal of Inorganic Nuclear Chemistry (1970) Vol. 32, 1089-1095 is known.

These divalent europium-activated alkaline earth and haloborate phosphors emit light as peaks at about 400 to 450 m under ultraviolet, X-ray, vacuum-ultraviolet or electron beam excitation depending on the type of alkaline earth as a parent constituent.

Therefore, this phosphor is promising as a blue phosphor for a high color rendering lamp, or as a phosphor for a copier lamp, and as a blue light emitting component phosphor of color and black and white television CRTs.

By the way, further improvement of luminous efficiency is desired for practical use. MEANS TO SOLVE THE PROBLEM The present inventors discovered that the luminous efficiency can be improved by studying lithium in a divalent europium-barb alkaline earth and a haloborate type fluorescent substance as a result of various examination in order to achieve the said request, and came to this invention.

The present invention relates to an alkaline earth metal haloborate phosphor having divalent europium as an activator, which contains lithium as a study lubricant.

Hereinafter, the present invention will be described.

Alkaline earth metal haloborate phosphors having a divalent europium as a parent of the phosphor of the present invention as an activator may be any conventionally known ones. For example, the composition formula is M2B5O8 x Eu2 +.

(Wherein M is an alkaline earth metal (for example, at least one of calcium, strontium and barium) and X is a halogen (for example, at least one of chlorine, bromine and iodine)).

In the phosphor of the present invention, the lithium content is preferably 5 × 10 −2 g / g or less, particularly preferably 3 × 10 −6 to 3 × 10 −4 g / g.

In addition, the present invention is a calcium, barium, chloroborate-based fluorescent substance containing a divalent europium containing lithium as a study activator, the barium content is 50 mol% or less of the sum of calcium, europium and barium, and the CIE color system of the emission color Also included are phosphors whose Y value of the chromaticity coordinates is 0.06 or greater.

In this fluorescent substance, it is preferable that lithium content is 1 * 10 <-3> g / g-3 * 10 <-2> g / g.

As an example of this phosphor,

Formula (Cai-i-j, Bal, Eu2 + j) 2B5O9Cl: Li

(In the formula, I is 0 <i≤0.5, and j is 0.0005≤j≤0.25). The phosphor raw material including calcium compound, barium compound, chloride, boron compound and europium compound is mixed with lithium compound do. As a phosphor raw material, the mixture of the following compounds can be used, for example.

(1) Calcium Compound

Calcium oxide or a calcium-containing compound that can be easily converted into calcium oxide at high temperatures such as nitrates and carbonates.

(2) barium compounds

Barium-containing compounds that can be easily converted to barium oxide at high temperatures such as barium oxide or nitrates, carbonates, and the like.

(3) chloride

Calcium chloride, barium chloride

(4) boron compounds

Boron oxide, boric acid

(5) Europium compound

Europium compounds which can be easily converted to europium oxide at high temperatures such as europium oxide or nitrates and chlorides.

The phosphor raw material containing the compound and the lithium compound are weighed in the above five groups, and the basis weight is sufficiently mixed with water or the like as a medium to obtain a paste-like mixture.

The resulting paste mixture is dried (for example, 140 ° C. for 8 hours), and then sieved to classify.

The phosphor raw material compound obtained by sifting and sorting is then fired in a high reducing atmosphere.

Firing in a reducing atmosphere can be performed, for example, by coexisting carbon.

More specifically, the phosphor raw material compound is filled into crucibles in a layered manner, and carbon such as amorphous carbon or graphite is disposed on the top and bottom of each raw material mixture through quartz cross, and the inside of the crucible is sealed.

The sealing in the crucible can be obtained by covering the opening of the crucible with an adhesive such as water glass.

The firing temperature is suitably, for example, about 800 to 980 ° C, preferably 850 to 950 ° C.

The firing time varies depending on the firing temperature, the amount of the raw material mixture to be calcined, and the like, for example, about 1 to 7 hours, preferably 2 to 5 hours is appropriate.

By firing under the above conditions, the crucible becomes a reducing atmosphere due to the presence of carbon.

This reducing atmosphere can be maintained more favorable by making the atmosphere other than the crucible into a neutral or verbal atmosphere.

Moreover, although the method of coexisting carbon was demonstrated and demonstrated as a formation method of a reducing atmosphere, baking can be performed under conditions, such as a method which can form the same reducing component crisis, for example, hydrogen atmosphere containing steam.

After firing, each operation employed in the phosphor manufacturing method such as washing, drying, and color classification can be performed in general, thereby obtaining the phosphor of the present invention.

In the manufacture of phosphors, a flux is often added to a phosphor raw material for the purpose of improving the luminous intensity, powder characteristics, etc. of the phosphor generally obtained.

In the production of the phosphor of the present invention, the ammonium chloride or the chloride of the phosphor raw material 3 is used in excess of the amount satisfying the above-mentioned mixed composition.

In addition, the excessive amount of the raw material 4 may be used for the flux. In addition, the phosphor represented by the present invention (I) may further contain a divalent element and / or a trivalent element as described above in order to improve characteristics such as luminance.

Examples of such elements include strontium, magnesium and zinc. It is preferable to contain at least one of these elements in the phosphor, and in particular, containing strontium is particularly preferable in terms of improving the Y value.

The present invention will be described by the following examples.

Example 1

Calcium Carbonate CaCO3 100g

Calcium chloride CaCl2, 2H2O 77g

Boron oxide C2O3 123g

Europium oxideEu2O3 8.4 g

Lithium Phosphate Li3PO4 9.1g

Water was added to the phosphor raw material, and the mixture was sufficiently mixed into a paste.

The resulting mixture was dried, ground by pulverization, charged into an alumina crucible and calcined at a temperature of 900 ° C. for 2 hours in a reducing atmosphere.

After baking, the baked material was pulverized, washed several times with warm water, and dried and sieved.

The phosphor thus obtained contains 100 ppm of Li, and exhibits good blue light emission of color purity under excitation of ultraviolet rays, vacuum ultraviolet rays, X-rays and electron beams.

This phosphor exhibited the same spectrum as the phosphor obtained in the same manner as in Example 1 except that lithium phosphate was not used, and the luminescence efficiency was as high as 6%.

Example 2

Calcium Carbonate CaCO3 100g

Calcium chloride CaCl2, 2H2Ol 77g

Boron oxide B2O3 123g

Euro europium Eu2O3 8.4g

Lithium Sulfate Li2SO4, H2O 1.51g

The phosphor obtained by treating the above-mentioned phosphor raw material in the same manner as in Example 1 was 8% higher in luminescence efficiency than the phosphor obtained without using lithium containing 30 ppm of lithium sulfate.

Example 3

Calcium Carbonate CaCO3 100g

Calcium chloride CaCl2, 2H2O 77g

Boron oxide B2O3 123g

Europium oxide Eu2O3 8.4 g

20 g of lithium chloride LiCl

The phosphor obtained by treating the phosphor raw material in the same manner as in Example 1 was 16% higher in luminous efficiency than the phosphor obtained without containing 56 ppm of Li and without using lithium chloride.

Example 4

Calcium Carbonate CaCO3 100g

Calcium chloride CaCl2, 2H2O 77g

Boron oxide B2O3 130g

Europium oxide Eu2O3 8.4 g

Lithium Sulfate Li2SO4, H2O 0.3g

The phosphor obtained by treating the above-mentioned phosphor raw material in the same manner as in Example 1 contained 7 ppm of Li and was 2% higher in luminous efficiency than the phosphor obtained without using lithium sulfate.

Example 5

Calcium Carbonate CaCO3 100g

Barium chloride BaCl2, 2H2O 298 g

Boron oxide B2O3 190g

Europium oxide Eu2O3 10.9 g

Lithium Chloride LiCl 14.6g

The phosphor obtained by treating the phosphor raw material in the same manner as in Example 1 contained 20,000 ppm of lithium, and the luminous efficiency was 12% higher than that of the phosphor obtained without using lithium chloride.

Example 6

Calcium Carbonate CaCO3 `100g

Calcium chloride CaCl2, 2H2O 45.3g

Barium chloride BaCl2, 2H2O 52g

Boron oxide B2O3 130g

Europium oxide Eu2O3 6.7g

10 g of lithium chloride LiCl

The phosphor obtained by treating in the same manner as in Example 1 contained 10,000 ppm of lithium and was 8% higher in luminous efficiency than the phosphor obtained without using lithium chloride.

The phosphor of the present invention has a higher luminous efficiency than the conventional alkaline earth metal haloborate phosphor with divalent europium as an activator, and has a blue phosphor for a high color rendering lamp, a phosphor for a copier, a lamp for a lamp, and a blue light for a television CRT. It is useful as a component phosphor.

Claims (8)

An alkaline earth metal haloborate phosphor comprising divalent europium as an activator, which contains lithium as a study lubricant. The phosphor according to claim 1, wherein the lithium content is 5 x 10 &lt; -2 &gt; g / g or less. The phosphor according to claim 1, wherein the lithium content is 3 × 10 −6 g / g to 3 × 10 −4 g / g. The fluorescent agent according to claim 1, which contains calcium and barium as alkaline earth metal and chlorine as halogen. The phosphor according to claim 4, wherein the lithium content is 1 × 10 −3 g / g to 3 × 10 −2 g / g. A process for producing an alkaline earth metal haloborate phosphor, characterized by firing a mixture of a raw material for an alkaline earth metal haloborate phosphor having a divalent europium as an activator and a lithium compound in a reducing atmosphere. The method for producing a phosphor according to claim 6, wherein the lithium compound is at least one of phosphate, sulfate, halide, borate, and carbonate of lithium. The process for producing a phosphor according to claim 6, wherein firing is carried out at least once at 800 to 980 캜.