JPH01190A - Fluorescent material and its manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an alkaline earth metal haloborate phosphor containing divalent europium as an activator. More specifically, it relates to a divalent europium-activated alkaline earth metal haloborate phosphor containing lithium as a co-activator.

[Conventional technology]

Conventionally, divalent europium-activated alkaline earth/haloborate phosphor C (MS8u”) was used as a haloborate phosphor.
Bs○9X (However, M is at least one of calcium, strontium, and barium, and X is at least one of chlorine, bromine, and iodine.)
[Journal of! organic nucl
ear Chemistry (1970) vol.
32.1089-1095) are known. These divalent europium-activated alkaline earth/haloborate phosphors have a peak at approximately 400 to 450 nm under ultraviolet, X-ray, vacuum ultraviolet, or electron beam excitation, depending on the type of alkaline earth that is the base component. It emits light. This phosphor is therefore promising as a blue phosphor for high color rendering lamps or as a phosphor for copier lamps, and as a phosphor for the blue-emitting component of color and monochrome television cathode ray tubes.

[Problem that the invention seeks to solve]

However, for practical use, it is currently desired to improve the luminous efficiency of the layer. As a result of various studies to achieve the above requirements, the present inventors have found that luminous efficiency can be improved by co-activating lithium into a divalent europium-activated alkaline earth/haloborate phosphor. This discovery led to the present invention.

[Means for solving problems]

The present invention relates to an alkaline earth metal haloborate phosphor using divalent europium as an activator, which is characterized by containing lithium as a co-activator.

The present invention will be explained below.

The alkaline earth metal haloborate phosphor using divalent europium as an activator, which is the base material of the phosphor of the present invention, may be any conventionally known phosphor, for example, one having a composition formula of M 2 B s ○sX:Eu" (in the formula, M is an alkaline earth metal (for example, at least one of calcium, strontium, and barium), and
is a halogen (for example at least one of chlorine, bromine and iodine).

In the phosphor of the present invention, the lithium content C is 5×10
It is preferably -6 g/g to 3 x 10-4 g/g, particularly preferably 3 x 10-6 to 3 x lo-4 g/g.

Furthermore, the present invention provides a solution containing lithium as a co-activator.
Calcium/barium/chloroborate-based phosphor using valence europium as an activator, the barium content is 50 mol% or less of the total of calcium, eurohyum, and hbarium, and the CrE table of the luminescent color is used. It also includes phosphors whose color system chromaticity coordinate has a y value of 0.06 or more. In the phosphor, the lithium content is lXl0--2g/
It is preferable that it is g~3XIV6g/g~3x10-4g/g. Examples of the phosphor include the formula (Ca+-+-i, Bat, Eu"J)2 BS
09Cj! : Ll (I) (wherein, 1
is 0×1≦0.5, and j is 0, 0005≦J≦
0.25) and its luminescent color, CIE
A chloroborate phosphor having a y value of chromaticity coordinate of a color system of 0.06 or more can be mentioned.

Further, the phosphor of the present invention includes, in addition to the phosphor whose composition is represented by the above formula (1), a divalent metal element (for example, Sr, Mg, Zn, Be5S) in the phosphor of the formula (I>).
nSPb, etc.), a phosphor containing a halogen other than chlorine, such as bromine, in place of some or all of the chlorine in the phosphor of formula (I), and a phosphor of formula (I) In the body, some of the boron is converted into trivalent elements other than boron (e.g. Aβ, Ga, In, etc.).

Tj! , Bi, etc.) is also included.

In addition, in formula (1) representing the composition of an example of the phosphor of the present invention,
1 is 0,025≦1≦ from the viewpoint of emission color and emission brightness.
Particularly preferred is 0.32.

Further, the y value of the CIE display system chromaticity coordinate of the emitted light color is particularly preferably 0.065 or more in order to provide high brightness.

The method for manufacturing the phosphor of the present invention will be explained below.

The phosphor of the present invention can be produced by firing a mixture of a raw material for an alkaline earth metal haloborate phosphor and a lithium compound using divalent europium as an activator in a reducing atmosphere. Firing at about 800-980°C, preferably 85°C
It is appropriate to carry out the reaction at a temperature of 0 to 950°C. Further, firing is performed once under the above conditions, and can be performed two or more times if necessary. Further, as the lithium compound, for example, phosphates, sulfates, halides, borates, and carbonates of lithium can be used alone or in combination of two or more.

The method for manufacturing the phosphor of the present invention will be explained below using the phosphor represented by the above formula (1) as an example.

Formula (Cat-1-J, Bat s Bu”j)2Bs
OsC1: Li (I (wherein, l is 0<i≦0.5
and ``is 0,0005≦''≦0.25)
A phosphor raw material containing a calcium compound, a barium compound, a chloride, a boron compound, and a europium compound prepared to satisfy the following conditions is mixed with a lithium compound.

For example, a mixture of the following compounds can be used as the phosphor raw material.

(1) Calcium compounds such as calcium oxide or nitrates, carbonates, etc., which are calcium-containing compounds that can be easily converted to calcium oxide at high temperatures. (2) Barium compounds: barium oxide, nitrates, carbonates, etc. that can be easily converted to barium oxide at high temperatures. Containing compounds (3) Chlorides Calcium chloride, barium chloride (4) Boron compounds boron oxide, boric acid) (5) Europium compounds Europium oxide or nitrates, chlorides, etc. Europium compounds that can be easily converted to europium oxide at high temperatures (5) A phosphor raw material containing two groups of compounds and the lithium compound are weighed, and the weighed raw materials are thoroughly mixed using water or the like as a medium to obtain a paste-like mixture. The resulting pasty mixture is dried (for example at 140° C. for 8 hours) and then sieved. The phosphor raw material mixture obtained by sieving is then fired in a highly reducing atmosphere. Firing in a reducing atmosphere can be performed, for example, by allowing carbon to coexist. More specifically, a crucible is filled with a phosphor raw material mixture in layers, amorphous carbon or carbon such as graphite is placed between the layers and on top of each raw material mixture via quartz cloth, and the inside of the crucible is sealed. I will do it. The inside of the crucible can be sealed, for example, by covering the opening of the crucible with an adhesive such as water glass. The firing temperature is, for example, approximately 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 fired, etc., but is suitably about 1 to 7 hours, preferably 2 to 5 hours, for example.

By performing the firing under the above conditions, the inside of the crucible becomes a reducing atmosphere due to the presence of carbon. The reducing atmosphere is
The atmosphere outside the crucible can be maintained more favorably by making it a neutral or reducing atmosphere.

In addition, as a method for forming a reducing atmosphere, the method of coexisting carbon has been explained as an example, but a method that can form a similar reducing atmosphere, for example, performing calcination under conditions such as a hydrogen atmosphere containing water vapor, etc. You can also do it.

After firing, the phosphor of the present invention can be obtained by performing various operations generally employed in phosphor manufacturing methods, such as washing, drying, and sieving.

In the production of phosphors, fluxing agents are often added to phosphor raw materials for the purpose of improving the luminance, powder properties, etc. of the phosphor obtained.

Also in the production of the phosphor of the present invention, ammonium chloride or the chloride of the phosphor raw material (3) can be used as a flux. When the chloride of the phosphor raw material (3) is used as a fluxing agent, the chloride of the phosphor raw material (3) is used in excess of the amount satisfying the above mixing compositional formula. Also, an excessive amount of raw material (4) may be used as a fluxing agent.

Note that the phosphor represented by formula (1) of the present invention may further contain a divalent element and/or a trivalent element as described above in order to improve characteristics such as brightness. Examples of such elements include strontium, magnesium and zinc. It is preferable that at least one of these elements be contained in the phosphor, and it is particularly preferable to contain strontium, since the y value can be improved.

The present invention will be explained below with reference to Examples.

Example 1 Calcium carbonate CaCO3 100g Calcium chloride CaCi z・2 Hz 77g Boron oxide
Btu3123 g europium oxide ELI,
03 8.4 g Lithium phosphate Ll3
P 04 9.1 g Water was added to the above phosphor raw material to form a paste and thoroughly mixed. The resulting mixture was dried and ground in a mortar, then filled into an aluminum crucible and fired at a temperature of 900° C. for 2 hours in a reducing atmosphere.

After firing, the fired product is crushed, washed several times with warm water, and dried.
Sieved. The phosphor thus obtained contained 1100 Li
It emits blue light with good color purity under excitation of pp-containing ultraviolet rays, vacuum ultraviolet rays, X-rays, and electron beams. This phosphor showed the same spectrum as the phosphor obtained in exactly the same manner as Example 1, except that lithium phosphate was not used, and the luminous efficiency was 6% higher.

Example 2 Calcium carbonate CaCO3 100g Calcium chloride CaCj! 2.2 H2C77g boron oxide
8203 123 g europium oxide
Eu2O+ 8.4g lithium sulfate
The phosphor obtained by treating the above phosphor raw material in the same manner as in Example 1 contains 3 opp of Li.
The luminous efficiency was 8% higher than that of a phosphor obtained without using m-containing lithium sulfate.

Example 3 Calcium carbonate CaC0, 100g chlorination power/l/
Cium CaCj! z・2 H2C? 7 g Boron oxide 8203 123 g Europium oxide Eu2038.4 g Lithium chloride 1c
The phosphor obtained by treating 20 g of the above phosphor raw material in the same manner as in Example 1 contains 56 ppm of Ll, which is 16 ppm compared to the phosphor obtained without using lithium chloride.
The luminous efficiency was also high.

Example 4 Calcium carbonate CaCO3 100g Calcilla chloride A
CaCj! z・2 H2C77g boron oxide
8203 130 g europium oxide
Snake u20. + 8.4g sulfuric acid 'J f Lum L12 S O'4' 820 3.3g The phosphor obtained by treating the above phosphor raw material in the same manner as in Example 1 was
The luminous efficiency was 2% higher than that of a phosphor obtained without using lithium sulfate.

Example 5 Calcium carbonate CaCO3 100g Barium chloride B
aCL・2 H2C298g Boron oxide 820
3 190g europium oxide E! u203
10.9 g Lithium chloride Lick
A phosphor obtained by treating 14.6 g of the above phosphor raw material in the same manner as in Example 1 was obtained by adding 20.00 g of lithium to the phosphor.
The luminous efficiency was 12% higher than that of a phosphor obtained without using lithium chloride.

Example 6 Calcium carbonate CaCO3100g Calcium chloride CaCL'2LO45,3g Barium chloride B
aCI! 2-2 H2C52g boron oxide Bi
a, 130g europium oxide Eu2O3
6.7g Lithium chloride LiCf
10g The phosphor obtained in the same manner as in Example 1 contained 10.0001) Ilm of lithium and had a luminous efficiency 8% higher than that of the phosphor obtained without using lithium chloride.

〔Effect of the invention〕

The phosphor of the present invention has higher luminous efficiency than the conventional alkaline earth metal haloborate phosphor using divalent europium as an activator, and is a blue phosphor for a high color rendering lamp. It is useful as a phosphor for copiers, lamps, and a blue-emitting component phosphor for television cathode ray tubes.

Procedural amendment document Showa year, month, day 1, case description 1988 patent application No. 155076
No. 2, Title of the invention Fluorescent material and its manufacturing method 3. Relationship with the case of the person making the amendment Applicant name Kasei Optonics Co., Ltd. 4, Agent 5, Date of amendment order Voluntary 6. Subject of amendment Description The following parts in the detailed description of the invention section of the specification are respectively corrected as follows.

Claims (8)

[Claims] (1) An alkaline earth metal haloborate phosphor using divalent europium as an activator, which is characterized by containing lithium as a co-activator. (2) The phosphor according to claim (1), which has a lithium content of 5 x 10^-^2 g/g or less. (3) Lithium content is 3x10^-^6g/g ~ 3x
Claim No. 1 in the range of 10^-^4g/g
). (4) The phosphor according to claim (1), which contains calcium and barium as alkaline earth metals and chlorine as a halogen. (5) Lithium content is 1x10^-^3g/g ~ 3x
10^-^2 g/g of the phosphor according to claim (4). (6) An alkaline earth metal haloborate characterized by firing a mixture of an alkaline earth metal haloborate phosphor raw material and a lithium compound using divalent europium as an activator in a reducing atmosphere. Method for producing salt phosphor. (7) The manufacturing method according to claim (6), wherein the lithium compound is at least one of lithium phosphates, sulfates, halides, borates, and carbonates. (8) The manufacturing method according to claim (6), wherein the firing is performed at least once at 800 to 980°C.