JP2001247862A - Aluminate fluorescent substance, its preparation process and device using this fluorescent substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a preparation process of an aluminate fluorescent substance which does not add any fluorine compound, improves the crystallinity of the aluminate fluorescent substance and controls the particle size and the shape. SOLUTION: A mixture of barium carbonate 12 (22 wt.%), basic magnesium carbonate 13 (11 wt.%), a globular alpha-alumina 11 having a particle size of 10 μm (65 wt.%) and europium oxide 14 (2 wt.%) is calcined in an atmosphere of a mixed gas of hydrogen and nitrogen with a hydrogen concentration of 5 vol.%. Here, the temperature is elevated at a rate of 400 deg.C/hr, the mixture is calcined at 1,700 deg.C for 2 hr, and the temperature is subsequently dropped at a rate of 400 deg.C/hr to obtain a globular aluminate fluorescent substance 15 of the formula: (Ba0.9, Eu0.1)MgAl10O17 having a particle size of 10 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a phosphor used for a fluorescent lamp, a display, and the like.

[0002]

2. Description of the Related Art In 1974, an aluminate phosphor developed by JMPJ Verstegen et al. For a three-band fluorescent lamp has become widely used with the spread of a three-band fluorescent lamp. .

[0003] A method of firing such an aluminate phosphor is described, for example, in Journal of Electrochemical Society 121 (1974), pp. 1623 to 1627 (J. Electrochem. Soc. 121 (1974) P.1).
623-1627), for example, the general formula (B
a _0.86 Eu _0.14 ) In the case of an aluminate phosphor represented by Mg ₂ Al ₁₆ O ₂₇ , barium carbonate, europium oxide,
Using magnesium carbonate and alumina as raw materials, 120
It is fired in a hydrogen reducing atmosphere at 0 ° C. At this time, by adding a fluoride compound such as aluminum fluoride or magnesium fluoride, the aluminate phosphor is applied to a device such as a fluorescent lamp or a display so that the aluminate phosphor is not deteriorated by heat treatment. In order to improve the crystallinity of the phosphor and further facilitate uniform application to the device, the particle size and shape of the aluminate phosphor are controlled by changing the amount of the fluorine compound added.

[0004]

In the conventional method for producing an aluminate phosphor, a fluorine compound such as aluminum fluoride is added to improve the crystallinity and control the particle size and shape. However, when a fluorine compound is added, extra costs are required in addition to the raw material due to its sublimation property, and since the fluorine compound is corrosive, the firing furnace is corroded and damaged. There is a problem that the crystallinity of the acid salt phosphor is not improved and the particle size and shape cannot be controlled.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and does not add a fluorine compound such as aluminum fluoride, improves the crystallinity of the aluminate phosphor, and controls the particle size and shape of the aluminate phosphor. An object of the present invention is to provide a method for producing an acid phosphate phosphor.

[0006]

In order to achieve the above object, a method for producing an aluminate phosphor of the present invention comprises an alkaline earth metal compound containing no fluorine molecules in atoms and a fluorine molecule contained in atoms. The present invention is characterized in that a rare earth compound and an aluminum compound containing no fluorine molecules in the atoms are calcined in a reducing atmosphere at a temperature higher than 1600 ° C. and lower than 2000 ° C.

In the method for producing an aluminate phosphor of the present invention, the reducing atmosphere is desirably a reducing atmosphere composed of a mixed gas of hydrogen gas and nitrogen gas.

In the method for producing an aluminate phosphor according to the present invention, the concentration of hydrogen gas in a reducing atmosphere comprising a mixed gas of hydrogen gas and nitrogen gas is 0.1% by volume or more.
It is desirably 0% by volume or less.

In the method for producing an aluminate phosphor of the present invention, it is preferable that the firing time is 5 minutes or more.

In the method for producing an aluminate phosphor of the present invention, the alkaline earth metal compound is a barium compound or a magnesium compound containing no fluorine atom in the molecule, and the rare earth compound contains a fluorine atom. A europium compound not contained in the molecule, and the aluminate phosphor is represented by the general formula (Ba _1-w , Eu _w ) Mg _x Al _y O _z, where 0.03 ≦ w ≦ 0.3, 0.8 ≦ x ≦ 1.2,
It is preferable that the composition be a composition represented by 8 ≦ y ≦ 12 and 14 ≦ z ≦ 20.

In the method for producing an aluminate phosphor according to the present invention, the alkaline earth metal compound is a magnesium compound containing no fluorine atom in the molecule, and the rare earth compound is free from a fluorine atom in the molecule. a cerium compound and a terbium compound, aluminate phosphor, the general formula _{(Ce 1-w, Tb w} ) Mg x Al y O z where, 0.03 ≦ w ≦ 0.6, 0.8 ≦ x ≦ 1.2,
It is preferable that the composition be a composition represented by 9 ≦ y ≦ 13 and 15 ≦ z ≦ 23.

In the method for producing an aluminate phosphor of the present invention, the alkaline earth metal compound is a strontium compound containing no fluorine atom in the molecule, and the rare earth compound is free from a fluorine molecule in the atom. A europium compound, wherein the aluminate phosphor is represented by the general formula (Sr _{4 (1-w)} , Eu _4w ) Al _x O _y, where 0.01 ≦ w ≦ 0.6, 11 ≦ x ≦ 17, 2
It is preferable that the composition be a composition represented by 0 ≦ y ≦ 30.

In the method for producing an aluminate phosphor of the present invention, the desired aluminate phosphor is converted into an aluminum compound containing no fluorine molecule in its atoms, which is a raw material of the aluminate phosphor. The same particle size as the particle size or
It is preferable to use aluminum compounds having substantially the same particle size.

In the method for producing an aluminate phosphor of the present invention, the particle diameter of the aluminum compound containing no fluorine atom in the molecule is preferably 1 μm or more and 20 μm or less.

In the method for producing an aluminate phosphor of the present invention, the desired aluminate phosphor may be formed in the form of an aluminum compound containing no fluorine atom in the molecule, which is a raw material of the aluminate phosphor. It is preferable to use an aluminum compound having the same shape or substantially the same shape as the body.

In the method for producing an aluminate phosphor of the present invention, the shape of the aluminum compound is preferably spherical or substantially spherical.

In the method for producing an aluminate phosphor according to the present invention, the alkaline earth metal compound containing no fluorine atom in the molecule may be an oxide, carbonate or basic carbonate of an alkaline earth metal. Desirably, the compound is at least one alkaline earth metal compound selected from the group consisting of salts, nitrates and chlorides.

In the method for producing an aluminate phosphor of the present invention, the rare earth compound containing no fluorine atom in the molecule is selected from the group consisting of oxides, carbonates, nitrates and chlorides of rare earth elements. Desirably, at least one selected rare earth compound is used.

Further, in the method for producing an aluminate phosphor of the present invention, the aluminum compound containing no fluorine atom in the molecule is a group consisting of aluminum oxide, chloride, nitrate, sulfate and alkoxide. Preferably, the compound is at least one aluminum compound selected from the group consisting of

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for producing an aluminate phosphor of the present invention, an alkaline earth metal compound containing no fluorine atom in a molecule, a rare earth compound containing no fluorine atom in a molecule, and a fluorine atom When an aluminum compound not included in the molecule is fired in a high-temperature reducing atmosphere at a temperature higher than 1600 ° C. and equal to or lower than 2000 ° C., the reaction is promoted, whereby the crystallinity can be improved without using a fluorine compound.

The alkaline earth metal compound containing no fluorine atom in the molecule of the raw material of the aluminate phosphor used in the present invention includes alkaline earth metal oxides, carbonates, and the like.
Basic carbonates, nitrates or chlorides are preferably used because they are relatively inexpensive and easily available, and are relatively stable compounds. Preferred specific examples of alkaline earth metal compounds containing no fluorine atom in the molecule include, for example, barium oxide, barium carbonate, barium nitrate, barium chloride, magnesium oxide, basic magnesium carbonate, magnesium nitrate, magnesium chloride, strontium oxide Strontium carbonate, strontium nitrate, strontium chloride, calcium oxide, calcium carbonate, calcium nitrate, calcium chloride and the like.

In order to further increase the luminance of the phosphor, a manganese compound containing no fluorine atom in the molecule, such as manganese oxide, manganese chloride, manganese carbonate or manganese nitrate, may be added.

The rare earth compound which does not contain fluorine atoms in the molecule of the raw material of the aluminate phosphor used in the present invention includes oxides, carbonates, nitrates or chlorides of rare earth elements which are relatively rare earth elements. Among the compounds, they are preferably used because they are inexpensive, easily available, and relatively stable. Specifically, for example, europium oxide,
Preferable examples include cerium oxide, terbium oxide, lanthanum oxide, and tamarium oxide. In addition to oxides, the various compounds described above can also be used.

The aluminum compound which does not contain a fluorine atom in the molecule of the material for the aluminate phosphor used in the present invention includes aluminum oxides, chlorides, nitrates, sulfates and carbon atoms of alkoxy groups. Are preferably used because they are relatively inexpensive and easily available, and are relatively stable compounds. Preferred specific examples of the aluminum compound containing no fluorine atom in the molecule of the raw material of the aluminate phosphor include, for example,
Examples include aluminum oxide, aluminum chloride, aluminum nitrate, aluminum sulfate, and triisopropoxy aluminum. Examples of aluminum oxide include alpha alumina and gamma alumina. In addition,
The aluminum compound which is not an oxide is preferably preliminarily fired in an oxidizing atmosphere in order to suppress the incorporation of elements other than oxygen into the phosphor as impurities.

The proportions of the alkaline earth metal compound, the rare earth compound and the aluminum compound to be used are different depending on the composition of the target aluminate phosphor, so it is difficult to unconditionally define them. 5 to 40% of alkaline earth metal compound, 0.1 to 10% of rare earth compound, 50 to 90% of aluminum compound in terms of atomic ratio of element, rare earth element and aluminum element
The range may be appropriately determined depending on the specific compound used and the composition of the target aluminate phosphor.

Further, in the production method of the present invention, since no fluorine compound is used, the particle size and / or the shape of the aluminate phosphor whose aluminum compound as the raw material of the aluminate phosphor is desired in advance are predetermined. By using an aluminum compound having the same or substantially the same particle size and / or shape as the diameter and / or the shape, the aluminate phosphor after firing reflects the particle size and the shape of the aluminum material, and By selecting the above, it is possible to synthesize the aluminate phosphor having the same or substantially the same particle size and the same or substantially the same shape. In the case of the conventional example using the above-described fluorine compound, generally, the larger the amount of the fluorine compound used, the larger the particle size of the obtained aluminate phosphor tends to be. Because of the plate shape, it is difficult to control the particle size and / or shape of the obtained aluminate phosphor.

The synthesized aluminate phosphor is usually
Appropriately dispersed in a suitable aqueous solvent or organic solvent, etc. together with a resin binder as required, and applied to a target device or the like. For example, the organic solvent is removed by heating in the air at 600 to 800 ° C. By oxidizing the carbon inside and removing it as carbon dioxide gas, it is fixed to the target device, but at this time, the particle shape and particle size that are easy to apply evenly and uniformly according to the solvent and device used are set It is desirable. Therefore, as described above, in the method of the present invention, the aluminate fluorescent material having the same particle size or substantially the same particle size and the same shape or substantially the same shape as the aluminum compound used as the raw material, as described above. Since it can be made into a body, there is an advantage that control of the particle size and shape of the obtained aluminate phosphor is extremely easy.

The particle size of the aluminate phosphor varies depending on the target device, but usually has a high coatability in the range of about 1 to 20 μm. When used for a fluorescent lamp, usually a range of about 1 to 10 μm is preferably used.

The shape of the particles of the aluminate phosphor varies depending on the purpose, and may be, for example, a flat plate, a hexagonal plate, or the like.
Examples include a spherical shape, a needle shape, and a cubic shape having a relatively sharp angle. When used in fluorescent lamps and displays, when the synthesized aluminate phosphor is fixed to the device, it is heated in the air at, for example, 600 to 800 ° C., so that it oxidizes from the surface and the brightness decreases. It is known from our experiments that the use of a spherical or substantially spherical aluminate phosphor reduces the specific surface area of the phosphor and reduces the degree of decrease in luminance with respect to heating in the atmosphere. And it is known from our experiments that it is suitable. Examples of the aluminum compound as a raw material of the spherical aluminate phosphor include, for example, an aluminum compound such as alpha-alumina which is exposed to high temperature such as plasma and spheroidized by quenching, or a high-purity spherical alumina manufactured by Admatex. Examples thereof include spheres formed by a self-baking method such as "Admafine". Further, as the aluminum compound as a raw material of the substantially spherical aluminate phosphor, as in the case of alumina “Sumicorundum” manufactured by Sumitomo Chemical Co., Ltd., once gasified, polyhedral such as octahedron was formed by crystallization. Aluminum oxide and the like can be mentioned.

Further, it is preferable to use a spherical or substantially spherical phosphor for a fluorescent lamp, a display, or the like because the transmittance of visible light increases and the light extraction efficiency increases. When the production method of the present invention is employed, for the above-described reason, if an aluminum compound having substantially the same particle size and shape as the target aluminate phosphor is used, the target particle size and shape can be reduced. An aluminate phosphor can be obtained.

In the method for producing an aluminate phosphor of the present invention, the alkaline earth metal compound is a barium compound or a magnesium compound containing no fluorine atom in the molecule, and the rare earth compound contains a fluorine atom. It is a europium compound not contained in the molecule, and the aluminate phosphor is represented by the general formula (Ba _1-w , Eu _w ) Mg _x Al _y O _z, provided that 0.03 ≦ w ≦ 0.3, 0.8 ≦ x ≦ 1.2,
By using a phosphor represented by 8 ≦ y ≦ 12 and 14 ≦ z ≦ 20, europium can be efficiently emitted, and a phosphor which emits blue light with high luminance is preferable.

In order to obtain the composition of the aluminate phosphor obtained as described above, the same ratio as the atomic ratio of the alkaline earth metal element, the rare earth metal element and the aluminum element represented by the above chemical formula is used. It can be obtained by blending the raw materials of the alkaline earth metal compound, the rare earth compound and the aluminum compound so that the alkaline earth metal element, the rare earth metal element and the aluminum element are contained, and firing the mixture under the reducing atmosphere as described above. .
The same applies to other compositions.

In the method for producing an aluminate phosphor according to the present invention, the alkaline earth metal compound is a magnesium compound containing no fluorine atom in the molecule, and the rare earth compound is free from a fluorine atom in the molecule. a cerium compound and a terbium compound, aluminate phosphor, the general formula _{(Ce 1-w, Tb w} ) Mg x Al y O z where, 0.03 ≦ w ≦ 0.6, 0.8 ≦ x ≦ 1.2,
By using an aluminate phosphor represented by 9 ≦ y ≦ 13, 15 ≦ z ≦ 23, terbium can be efficiently emitted, and a phosphor emitting green light with high luminance can be obtained, which is preferable. .

In the method for producing an aluminate phosphor of the present invention, the alkaline earth metal compound is a strontium compound containing no fluorine atom in the molecule, and the rare earth compound is free from a fluorine molecule in the atom. A europium compound, wherein the aluminate phosphor is represented by the general formula (Sr _{4 (1-w)} , Eu _4w ) Al _x O _y, where 0.01 ≦ w ≦ 0.6, 11 ≦ x ≦ 17, 2
By making the phosphor represented by 0 ≦ y ≦ 30,
This is preferable because europium can be efficiently emitted and a phosphor that emits blue-green light with high luminance can be obtained.

[0035]

(Example 1) Method for producing aluminate phosphor (hereinafter abbreviated as BAM phosphor) represented by chemical formula (Ba _0.9 , Eu _0.1 ) MgAl ₁₀ O ₁₇ Hereinafter, a first embodiment of the present invention will be described. This will be described with reference to Table 1. Table 1 shows the types of raw materials for synthesizing the BAM phosphor and the weight percentage ratio of the raw materials.

[0036]

[Table 1]

Barium carbonate and basic magnesium carbonate were used as the alkaline earth metal compound, alpha alumina was used as the aluminum compound, and europium oxide was used as the rare earth compound.

The raw materials having the weight percentage ratios shown in Table 1 were mixed and pulverized with a mortar, a ball mill, or the like, and fired in a tubular furnace using a mixed gas of nitrogen gas and hydrogen gas. The flow rate of the nitrogen gas was 380 ml / min, the flow rate of the hydrogen gas was 20 ml / min, and the hydrogen concentration was 5% by volume. The BAM phosphor was synthesized by raising the temperature at a rate of 400 ° C./hour, firing at 1700 ° C. for 2 hours, and lowering the temperature at 400 ° C./hour. The concentration of hydrogen gas at the time of sintering is sufficient if the concentration is 0.1% by volume or more because hydrogen has a strong reducing power. When the concentration of hydrogen gas is higher than 10% by volume, the concentration is preferably 10% by volume or less because the strong reducing power inhibits the synthesis of the BAM phosphor. The firing time is 160
At a high temperature of 0 ° C. or higher, the diffusion reaction proceeds quickly.
If it is longer than minutes, the synthesis is completed.

The high crystallization in the above-described BAM phosphor and its manufacturing method will be described with reference to FIG.

In FIG. 1, the vertical axis represents the strongest peak in the X-ray diffraction spectrum of the crystal of the BAM phosphor.
It is the half width of the 07 plane.

Here, the half width of the X-ray diffraction spectrum indicates the crystallinity of the BAM phosphor. The smaller the half width, the higher the crystallinity, and the higher the crystallinity, the more the BAM phosphor is converted into a fluorescent lamp or the like. It has been found from our experiments that the deterioration of the brightness of the BAM phosphor due to the heat treatment when applied to a device such as a display is small.

The horizontal axis is the reciprocal of the firing temperature (K) at the time of synthesizing the BAM phosphor. The firing temperature (° C) is shown in the upper part of FIG.
The scale is given for reference. In FIG. 1, the points indicated by the triangles are the measured data of the half-value width of the X-ray diffraction spectrum of the BAM phosphor of this example. In FIG. 1, the solid line a is a linear function obtained by fitting the measured data of the half-value width of the X-ray diffraction spectrum using the least square method. Here, the X-ray diffraction spectrum of the conventional BAM phosphor using a fluorine compound is shown as 1
For comparison, the half-value width of the 07 surface is indicated by a broken line b in the graph of FIG.
Indicated by

As shown by the solid line a in FIG. 1, as the firing temperature of the BAM phosphor of this embodiment increases, the half-value width of the X-ray diffraction spectrum decreases.
When the temperature exceeds 1600 ° C., BA using a fluorine compound
It is smaller than the half width (dashed line b) of the 107 plane of the X-ray diffraction spectrum of the M phosphor. That is, the crystallinity is higher than that of a conventional BAM phosphor using a fluorine compound as a reaction accelerator.

Further, it has been found by our experiments that the BAM phosphor melts at a temperature higher than 2000 ° C. Therefore, in FIG. 1, in the region higher than 2000 ° C., the half width of the X-ray diffraction spectrum is actually saturated.

Thus, the temperature is higher than 1600 ° C. and 2000 ° C.
By firing in the following high-temperature reducing atmosphere, the reaction is promoted, the crystallinity can be improved without using a fluorine compound, and a high-luminance BAM phosphor can be obtained.

(Example 2) Method for producing aluminate phosphor (hereinafter abbreviated as CAT phosphor) represented by chemical formula (Ce _0.67 , Tb _0.33 ) MgAl ₁₁ O ₁₉ Hereinafter, a second embodiment of the present invention will be described. This will be described with reference to Table 2. Table 2 shows the types of raw materials for synthesizing the CAT phosphor and the weight percentage ratio of the raw materials.

[0047]

[Table 2]

Basic magnesium carbonate was used as an alkaline earth metal compound, alpha alumina was used as an aluminum compound, and cerium oxide and terbium oxide were used as rare earth compounds.

The raw materials having the weight percentage ratios shown in Table 2 were mixed in a mortar, a ball mill, or the like, and fired in a tubular furnace using a mixed gas of nitrogen gas and hydrogen gas. The flow rate of nitrogen gas is 3
The flow rate of hydrogen gas was 20 ml / min, and the concentration of hydrogen gas was 5%. The CAT phosphor was synthesized by raising the temperature at a rate of 400 ° C./hour, firing at 1700 ° C. for 2 hours, and then reducing the temperature at 400 ° C./hour.

High crystallization in the above-described CAT phosphor and its manufacturing method will be described with reference to FIG.

In FIG. 2, the vertical axis is the strongest peak in the X-ray diffraction spectrum of the crystal of the CAT phosphor.
It is a half width of 14 surfaces.

As in Example 1, the half-width of the X-ray diffraction spectrum indicates the crystallinity of the CAT phosphor. The smaller the half-width, the higher the crystallinity, and the higher the crystallinity, the higher the CAT fluorescence. CAT by heat treatment when applying body to devices such as fluorescent lamps and displays
It is known from our experiments that the luminance degradation of the phosphor is small.

The horizontal axis is the reciprocal of the firing temperature (K) during the synthesis of the CAT phosphor. The firing temperature (° C) is shown in the upper part of FIG.
The scale is given for reference. In FIG. 2, the points indicated by ● are the measured data of the half width of the X-ray diffraction spectrum of the CAT phosphor. In FIG. 2, the solid line a is a linear function obtained by fitting the measured data of the half-width of the X-ray diffraction spectrum using the least square method. Here, the X-ray diffraction spectrum of the CAT phosphor obtained by the above-mentioned conventional method using a fluorine compound is 114.
The half width of the surface is indicated by a broken line b in the graph of FIG. 2 for comparison. As is clear from FIG. 2, as the firing temperature of the CAT phosphor of this example was increased, the half-width of the X-ray diffraction spectrum was reduced, and when it exceeded 1600 ° C., the CAT phosphor of the conventional method using a fluorine compound was used. It becomes smaller than the half width (dashed line b) of the 114 plane of the X-ray diffraction spectrum of the body. That is, the crystallinity is higher than that of a conventional CAT phosphor using a fluorine compound as a reaction accelerator.

Further, it is known from our experiments that the CAT phosphor of this embodiment melts at a temperature higher than 2000 ° C. like the BAM phosphor of the first embodiment. Therefore, in FIG. 2, in the region higher than 2000 ° C., the half width of the X-ray diffraction spectrum is actually saturated.

As described above, the temperature higher than 1600 ° C. and 2000 ° C.
By firing in the following high-temperature reducing atmosphere, the reaction is promoted, the crystallinity can be improved without using a fluorine compound, and a high-brightness CAT phosphor can be obtained.

(Example 3) Method for producing aluminate phosphor having the same or substantially the same particle size as the raw aluminum compound and having the same or substantially the same shape Next, a drawing of a third embodiment of the present invention will be described with reference to the drawings. It will be described with reference to FIG.

FIG. 3 is a schematic view showing a reaction state in the manufacturing process of the aluminate phosphor according to the third embodiment of the present invention when spherical alumina having a particle diameter of 10 μm is used as an aluminum compound as a raw material. . Note that this embodiment is also described using a BAM phosphor as in the first embodiment. Also,
The synthesis process is the same as in Example 1.

In FIG. 3, the manufacturing process of the aluminate phosphor proceeds from (A) to (D) in FIG. FIG.
(A) shows spherical particles in the state of alpha alumina 11 alone, which is a raw material of the BAM phosphor,
(B) shows the above-mentioned alpha alumina 11, barium carbonate 12, basic magnesium carbonate 1 which is a raw material of a BAM phosphor.
3 shows a state of a mixture in which europium oxide 14 is mixed. (C) is a schematic diagram of a state during firing in the firing step of the mixture of (B). (D) shows the synthesized BAM phosphor 15. The synthesis process is the same as in Example 1.

Spherical alpha alumina 1 having a particle size of 10 μm
1 (FIG. 3A) is mixed and ground with barium carbonate 12, basic magnesium carbonate 13, and europium oxide 14, which are other raw materials. However, although other raw materials are pulverized, the alpha alumina 11 is hard to be pulverized due to its high hardness, and there is almost no change in the particle size and shape (FIG. 3B). During firing at a temperature of 1600 ° C. or more, barium carbonate 12, basic magnesium carbonate 13, and europium oxide 14, which are other raw materials, are diffused and mixed into the alpha alumina 11 ((C) in FIG. 3). A spherical BAM phosphor 15 having the same particle size (10 μm) and the same shape as the alpha alumina 11 was obtained ((D) in FIG. 3).

Next, FIG. 4 shows the result of examining the dependency of the synthesized BAM phosphor on the particle diameter of the alumina raw material. In FIG. 4, the horizontal axis represents the average particle diameter of alpha alumina as a raw material, and the vertical axis represents the average particle diameter of the synthesized BAM phosphor.
FIG. 4 shows that the average particle size of the BAM phosphor depends on the average particle size of alpha alumina as a raw material.

The aluminate phosphor has a particle size of 15 μm.
FIG. 5 shows electron microscope photographs of the results of observation with an electron microscope before and after sintering in the case of using alumina having a square shape of m as the raw material aluminum compound. In FIG. 5, (A), (B), and (C) show (A),
(B), the state in the process corresponding to (D) is shown. Here, angular alpha alumina having an average particle size of 15 μm is used, but comparing FIG. 5A and FIG. 5C shows that the particle size and angular shape of the alpha alumina are maintained. I understand.

As described above, by selecting the particle size and shape of the aluminum compound, an aluminate phosphor having an arbitrary particle size and shape can be obtained without using a fluorine compound.

In the first embodiment and the third embodiment, (B
Although the explanation has been made using the aluminate phosphor represented by a _0.9 , Eu _0.1 ) MgAl ₁₀ O ₁₇ , the region where a single crystal is generated is represented by the general formula (Ba _{1 -w} , Eu _w ) Mg
_x Al _y O _z , where 0.03 ≦ w ≦ 0.3, 0.8 ≦
A composition range represented by x ≦ 1.2, 8 ≦ y ≦ 12, and 14 ≦ z ≦ 20 is desirable. In the above general formula,
0.03 ≦ w ≦ 0.3, 0.97 <x <1.03,
If 9.7 <y <10.3 and 16 <z <18, the stability is particularly high against oxidation by heat, and the luminance by the heating process in the air generated when the phosphor is applied to the device is increased. An aluminate phosphor with extremely small deterioration can be obtained, which is more preferable.

Although barium carbonate and basic magnesium carbonate are used as alkaline earth metal compounds as raw materials of the BAM phosphor, other alkaline earth metal compounds such as barium nitrate and barium chloride may be used. Although alpha alumina was used as the aluminum compound,
Other aluminum compounds such as gamma alumina, aluminum chloride, aluminum nitrate, aluminum sulfate, and triisopropoxy aluminum may be used.
In this case, it is more preferable that the aluminum compound which is not an oxide is preliminarily fired in an oxidizing atmosphere, because unnecessary elements other than oxygen are prevented from being mixed as impurities into the phosphor.

Further, a calcium compound or a strontium compound may be added as an alkaline earth metal compound. Further, a manganese compound such as manganese oxide may be added to further increase the luminance.

In Example 2, the chemical formula (Ce
_0.67, Tb _0.33) showed the example represented by MgAl ₁₁ O _19, as the region capable single crystal of the composition, the general formula _{(Ce 1-w, Tb w} ) Mg x Al y O z, However, 0.0
3 ≦ w ≦ 0.6, 0.8 ≦ x ≦ 1.2, 9 ≦ y ≦ 1
It is preferable that the composition range is represented by 3, 15 ≦ z ≦ 23. In the above general formula, 0.03 ≦ w
≦ 0.6, 0.97 <x <1.03, 10.7 <y
In the case of <11.3, 18 ≦ z ≦ 20, the stability is particularly high with respect to oxidation by heat, and the deterioration of luminance due to the heating step in the air which occurs when the phosphor is applied to the device is extremely low. A small aluminate phosphor can be obtained,
More preferred.

In the first to third embodiments, (B
a _0.9 , Eu _0.1 ) MgAl ₁₀ O ₁₇ or (Ce
_{An example of 0.67} , Tb _0.33 ) MgAl ₁₁ O ₁₉ is shown, and the phosphor has a chemical formula of (Sr, Eu) ₄ Al ₁₄ O ₂₅ , (S
The same effect can be obtained with a phosphor having a composition such as (r, Eu) Al ₂ O ₄ or (Ca, Eu) Al ₂ O ₄ .

In the third embodiment, the shape of the alpha alumina 11 may be any one of a plate shape, a hexagonal plate shape, a spherical shape, and a needle shape. It is possible to obtain an aluminate phosphor with extremely small luminance degradation due to heating in the atmosphere at the time.
More preferred.

[0069]

The method for producing an aluminate phosphor of the present invention comprises an alkaline earth metal compound containing no fluorine atom in the molecule, a rare earth compound containing no fluorine atom in the molecule, and a fluorine atom contained in the molecule. By baking an aluminum compound not contained in a high temperature of 1600 ° C. or higher and 2,000 ° C. or lower in a reducing atmosphere, it is possible to improve crystallinity without using a fluorine compound which easily sublimates and has high corrosiveness. Can provide a high quality aluminate phosphor. Since a fluorine compound that easily sublimates is not used, there are few components that are sublimated and lost during firing, and the cost can be reduced. Since a highly corrosive fluorine compound is not used, the risk of corrosion and breakage of the firing furnace can be reduced.

In the method for producing an aluminate phosphor of the present invention, the reducing atmosphere is preferably a reducing atmosphere composed of a mixed gas of hydrogen gas and nitrogen gas. It is preferable because a desired reducing atmosphere can be realized.

In the method for producing an aluminate phosphor of the present invention, the concentration of hydrogen gas in a reducing atmosphere composed of a mixed gas of hydrogen gas and nitrogen gas is 0.1 vol% or more and 10 vol% or less.
By setting the preferred embodiment of the present invention to not more than% by volume, the synthesis of the aluminate phosphor is favorably performed without being hindered.

Further, in the method for producing an aluminate phosphor of the present invention, the preferred embodiment of the present invention in which the calcination time is 5 minutes or longer allows the aluminate phosphor to be completely synthesized. It is preferable to obtain a high quality aluminate phosphor.

In the method for producing an aluminate phosphor of the present invention, the alkaline earth metal compound is a barium compound or a magnesium compound containing no fluorine atom in the molecule, and the rare earth compound is a fluorine atom containing the fluorine atom in the molecule. Which is a europium compound not contained therein and whose aluminate phosphor is represented by the general formula (Ba _1-w , Eu _w ) Mg _x Al _y O _z, provided that 0.03 ≦ w ≦ 0.3, 0.8 ≦ x ≦ 1.2,
By adopting a preferred embodiment of the present invention having a composition represented by 8 ≦ y ≦ 12 and 14 ≦ z ≦ 20, europium can be efficiently emitted, and a phosphor that emits blue light with high luminance can be obtained. This is preferable.

In the method for producing an aluminate phosphor of the present invention, the alkaline earth metal compound is a magnesium compound containing no fluorine atom in the molecule, and the rare earth compound is a cerium compound containing no fluorine atom in the molecule. compound and a terbium compound, aluminate phosphor, the general formula _{(Ce 1-w, Tb w} ) Mg x Al y O z where, 0.03 ≦ w ≦ 0.6, 0.8 ≦ x ≦ 1 .2,
By providing a preferred embodiment of the present invention having a composition represented by 9 ≦ y ≦ 13 and 15 ≦ z ≦ 23, it is possible to obtain a phosphor that can efficiently emit terbium and emit green light with high luminance. Is preferred.

In the method for producing an aluminate phosphor of the present invention, the alkaline earth metal compound is a strontium compound containing no fluorine atom in the molecule, and the rare earth compound is a europium compound containing no fluorine molecule in the atom. A compound, wherein the aluminate phosphor is represented by the general formula (Sr _{4 (1-w)} , Eu _4w ) Al _x O _y, where 0.01 ≦ w ≦ 0.6, 11 ≦ x ≦ 17, 2
By adopting a preferred embodiment of the present invention having a composition represented by 0 ≦ y ≦ 30, europium can be efficiently emitted, and a phosphor that emits blue-green light with high luminance is preferably obtained.

Further, in the method for producing an aluminate phosphor of the present invention, a desired aluminate phosphor particle is used as an aluminum compound containing no fluorine molecule in its atoms as a raw material of the aluminate phosphor. By using a preferred embodiment of the present invention using an aluminum compound having the same particle diameter as the diameter or substantially the same particle diameter, firing the aluminate phosphor having the same particle diameter as the aluminum compound or the substantially same particle diameter. Therefore, it is possible to provide a method for producing an aluminate phosphor in which the particle size can be easily controlled.

Further, in the method for producing an aluminate phosphor of the present invention, the particle diameter of the aluminum compound containing no fluorine atom in the molecule, which is a raw material of the aluminate phosphor, is 1 μm.
By adopting a preferred embodiment of the present invention having a thickness of at least 20 m and at most 20 m, a method for producing an aluminate phosphor excellent in coatability when applied to a device can be provided.

In the method for producing an aluminate phosphor of the present invention, the desired aluminate phosphor may be formed in the form of an aluminum compound containing no fluorine atom in the molecule, which is a raw material of the aluminate phosphor. By using a preferred embodiment of the present invention using an aluminum compound having the same shape or substantially the same shape as the above, an aluminate phosphor having the same shape or substantially the same shape as the aluminum compound can be obtained. Can provide a method for producing an aluminate phosphor that can be easily controlled.

In the method for producing an aluminate phosphor of the present invention, the specific surface area of the phosphor can be reduced by adopting a preferred embodiment of the present invention in which the shape of the aluminum compound is spherical or substantially spherical. It is preferable because an aluminate phosphor having a very low degree of decrease in luminance with respect to heating in the air at the time of applying the phosphor can be obtained. Further, by using the spherical or substantially spherical aluminate phosphor for a fluorescent lamp, a display, or the like, the transmittance of visible light is increased, the light extraction efficiency is increased, and the excellent aluminate phosphor is used. Can be provided.

In the method for producing an aluminate phosphor of the present invention, the alkaline earth metal compound containing no fluorine atom in the molecule may be an oxide or carbonate of an alkaline earth metal.
According to a preferred embodiment of the present invention, which is at least one kind of alkaline earth metal compound selected from the group consisting of basic carbonate, nitrate and chloride, these alkaline earth metal compounds are relatively inexpensive. The compound is easily available and is relatively stable, so that it is easy to handle and preferable.

In the method for producing an aluminate phosphor of the present invention, the rare earth compound containing no fluorine atom in the molecule is selected from the group consisting of oxides, carbonates, nitrates and chlorides of rare earth elements. By adopting a preferred embodiment of the present invention, which is at least one rare earth compound, these rare earth compounds are relatively inexpensive and easily available among rare earth compounds, and are relatively stable compounds. Is also easy and preferable.

Further, in the method for producing an aluminate phosphor of the present invention, the aluminum compound containing no fluorine atom in the molecule is selected from aluminum oxide, chloride, nitrate,
By adopting a preferred embodiment of the present invention, which is at least one aluminum compound selected from the group consisting of sulfates and alkoxides, these aluminum compounds are relatively inexpensive, easily available, and relatively stable compounds. Therefore, handling is easy and preferable.

[Brief description of the drawings]

FIG. 1 is a characteristic diagram showing the relationship between the firing temperature and the crystallinity of an aluminate phosphor obtained according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the firing temperature and the crystallinity of an aluminate phosphor obtained according to a second embodiment of the present invention.

FIG. 3 is a schematic view showing a reaction state in a manufacturing process when a spherical aluminum compound according to a third embodiment of the present invention is used.

FIG. 4 is a characteristic diagram showing the dependency correlation of the phosphor of the third embodiment of the present invention with the particle size of the alumina raw material.

FIG. 5 is a sketch of an electron micrograph showing an observation result of a reaction state in a manufacturing process when angular alumina is used as a raw material aluminum compound in a third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 11 alpha alumina particles 12 barium carbonate particles 13 basic magnesium carbonate particles 14 europium oxide particles 15 BAM phosphor particles

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[Procedure amendment]

[Submission date] March 13, 2001 (2001.3.1.
3)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Method for producing aluminate phosphor and its [Title of the Invention],
And device using this phosphor

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a phosphor used for a fluorescent lamp, a display, and the like.

[0002]

2. Description of the Related Art In 1974, an aluminate phosphor developed by JMPJ Verstegen et al. For a three-band fluorescent lamp has become widely used with the spread of a three-band fluorescent lamp. .

[0003] A method of firing such an aluminate phosphor is described, for example, in Journal of Electrochemical Society 121 (1974), pp. 1623 to 1627 (J. Electrochem. Soc. 121 (1974) P.1).
623-1627), for example, the general formula (B
a _0.86 Eu _0.14 ) In the case of an aluminate phosphor represented by Mg ₂ Al ₁₆ O ₂₇ , barium carbonate, europium oxide,
Using magnesium carbonate and alumina as raw materials, 120
It is fired in a hydrogen reducing atmosphere at 0 ° C. At this time, by adding a fluorine compound such as aluminum fluoride or magnesium fluoride, in applying the A Rumin phosphor to a device such as a fluorescent lamp or a display, the aluminate so as not to deteriorate by heat treatment to improve the crystallinity of the phosphor, by changing the amount of fluoride <br/> containing compound in order to facilitate uniformly applied to the device to further control the particle size and shape of the a Rumin phosphor ing.

[0004]

In the conventional method for producing an aluminate phosphor, a fluorine compound such as aluminum fluoride is added to improve the crystallinity and control the particle size and shape. However the addition of fluorine compound, its and excess costly that in addition the raw material from sublimation, fluorine compounds firing furnace is corroded damaged because of its corrosive property and, A Le to be added fluorine compound There is a problem that the crystallinity of the mate phosphor is not improved, and the particle size and shape cannot be controlled.

The present invention solves the above-mentioned conventional problems, and does not require the addition of a fluorine compound such as aluminum fluoride.
Another object of the present invention is to provide a method for producing an aluminate phosphor capable of controlling the particle size and shape.

[0006]

In order to achieve the above object,
A method for producing an aluminate phosphor of the present inventionForm of
IsIf the particle size is the same as the desired aluminate phosphor particle size
Or the aluminum containing aluminum oxide having substantially the same particle size.
By firing the raw material of the phosphate phosphor,
The present invention is characterized in that an aluminate phosphor is obtained. Ma
Another form of the method for producing an aluminate phosphor of the present invention
The shape may be the same as the desired aluminate phosphor shape.
Or the aluminum containing aluminum oxide of substantially the same shape
By baking the raw material of phosphate phosphate,
Characterized by obtaining an aluminate phosphor having the same.

In the method for producing an aluminate phosphor of the present invention, it is preferable that the calcination is performed in a reducing atmosphere.
Further , it is desirable that this reducing atmosphere is a reducing atmosphere composed of a mixed gas of hydrogen gas and nitrogen gas.

In the method for producing an aluminate phosphor according to the present invention, the concentration of hydrogen gas in a reducing atmosphere comprising a mixed gas of hydrogen gas and nitrogen gas is 0.1% by volume or more.
It is desirably 0% by volume or less.

In the method for producing an aluminate phosphor of the present invention, it is preferable that the firing time is 5 minutes or more.

[0010] Also, in the manufacturing method of the aluminate phosphor of the present invention, A Rumin phosphor has the general formula _{(Ba 1-w, Eu w} ) where _{Mg x Al y O z, 0} . 03 ≦ w ≦ 0.3, 0.8 ≦ x ≦ 1.2,
It is preferable that the composition be a composition represented by 8 ≦ y ≦ 12 and 14 ≦ z ≦ 20.

[0011] Also, in the manufacturing method of the aluminate phosphor of the present invention, A Rumin phosphor has the general formula _{(Ce 1-w, Tb w} ) where _{Mg x Al y O z, 0} . 03 ≦ w ≦ 0.6, 0.8 ≦ x ≦ 1.2,
It is preferable that the composition be a composition represented by 9 ≦ y ≦ 13 and 15 ≦ z ≦ 23.

[0012] Also, in the manufacturing method of the aluminate phosphor of the present invention, A Rumin phosphor has the general formula _{(Sr 4 (1-w)} , Eu 4w) Al x O y where 0 .01 ≦ w ≦ 0.6, 11 ≦ x ≦ 17, 2
It is preferable that the composition be a composition represented by 0 ≦ y ≦ 30.

Further, in the manufacturing method of the aluminate phosphor of the present invention, properly even particle size equal diameter and aluminate phosphors Nozomu Tokoro is that aluminum oxide having substantially the same diameter preferable.

Further, in the method for producing an aluminate phosphor of the present invention, it is preferable that the particle diameter of the aluminum oxide is 1 μm or more and 20 μm or less.

Further, in the manufacturing method of the aluminate phosphor of the present invention, the same shape of the aluminate phosphor to Nozomu Tokoro also properly it is preferable to use an aluminum oxide substantially the same shape.

[0016] Also, in the manufacturing method of the aluminate phosphor of the present invention, the shape of the aluminum oxide spherical or
It is preferably substantially spherical.

Further, in the method for producing an aluminate phosphor of the present invention, the raw material of the aluminate phosphor is alkali.
An alkaline earth metal compound , wherein the alkaline earth metal compound has at least one fluorine atom selected from the group consisting of alkaline earth metal oxides, carbonates, basic carbonates, nitrates and chlorides. It is desirable that the compound is an alkaline earth metal compound not contained in the molecule .

In the method for producing an aluminate phosphor of the present invention, the raw material of the aluminate phosphor is rare earth
The rare earth compound is a rare earth compound not containing at least one fluorine atom selected from the group consisting of oxides, carbonates, nitrates and chlorides of rare earth elements in the molecule. Desirably .

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION In the method for producing an aluminate phosphor of the present invention, an alkaline earth metal compound containing no fluorine atom in the molecule, a rare earth compound containing no fluorine atom in the molecule, and aluminum oxide are used. Is fired in a high-temperature reducing atmosphere at a temperature higher than 1600 ° C. and equal to or lower than 2000 ° C., whereby the reaction is promoted and the crystallinity can be improved without using a fluorine compound.

[0020] As used in the present invention, the alkaline earth metal compound containing no raw material fluorine atoms A Rumin phosphor in the molecule, oxides of alkaline earth metals, carbonates, basic carbonates, nitrates Alternatively, chloride and the like are preferably used because they are relatively inexpensive and easily available, and are relatively stable compounds. Preferred specific examples of the alkaline earth metal compound containing no fluorine atom in the molecule include, for example, barium oxide, barium carbonate, barium nitrate, barium chloride,
Examples include magnesium oxide, basic magnesium carbonate, magnesium nitrate, magnesium chloride, strontium oxide, strontium carbonate, strontium nitrate, strontium chloride, calcium oxide, calcium carbonate, calcium nitrate, calcium chloride and the like.

In order to further increase the luminance of the phosphor, a manganese compound containing no fluorine atom in the molecule, such as manganese oxide, manganese chloride, manganese carbonate or manganese nitrate, may be added.

Moreover, used in the present invention, the rare earth compound containing no raw material fluorine atoms A Rumin phosphor in the molecule, oxides of rare earth elements, carbonates, nitrates or the like chlorides relatively rare Among the compounds, they are preferably used because they are inexpensive, easily available, and relatively stable. Specifically, preferable examples include europium oxide, cerium oxide, terbium oxide, lanthanum oxide, and tamarium oxide. In addition to oxides, the various compounds described above can also be used.

Examples of the aluminum oxide used in the present invention include alpha alumina and gamma alumina .

The proportions of the alkaline earth metal compound, the rare earth compound and the aluminum oxide used differ depending on the composition of the target aluminate phosphor.
Although it is difficult to stipulate a general rule, 5 to 40% of an alkaline earth metal compound, 0.1 to 10% of a rare earth compound, 50 of aluminum oxide, The range of about 90% may be appropriately determined depending on the specific compound used and the composition of the target aluminate phosphor.

Further, the in the production method of the present invention does not use fluorine compounds, a raw material of A Rumin acid phosphor
Oxide Al particle size and / or particle size and / or the same or substantially the same as the shapes of the pre-desired aluminate phosphor particle size and / or shape of the aluminum oxide
By using minium, the aluminate phosphor after firing reflects the particle size and shape of aluminum oxide . did
Therefore, by selecting the aluminum oxide can be synthesized by the same particle size or substantially the same particle size, and the same shape or A Rumin phosphor having substantially the same shape. In the case of the conventional example using the above-described fluorine compound, generally, the larger the amount of the fluorine compound used, the larger the particle size of the obtained aluminate phosphor tends to be. Because of the plate shape, it is difficult to control the particle size and / or shape of the obtained aluminate phosphor.

The synthesized aluminate phosphor is usually
Appropriately dispersed in a suitable aqueous solvent or organic solvent, etc. together with a resin binder as required, and applied to a target device or the like. For example, the organic solvent is removed by heating in the air at 600 to 800 ° C. By oxidizing the carbon inside and removing it as carbon dioxide gas, it is fixed to the target device, but at this time, the particle shape and particle size that are easy to apply evenly and uniformly according to the solvent and device used are set It is desirable. Therefore, as described above, in the method of the present invention, the oxide used
Since the aluminate phosphor having the same particle size or substantially the same particle size as that of luminium, and the same shape or substantially the same shape can be obtained, it is extremely easy to control the particle size and shape of the obtained aluminate phosphor. Has advantages.

The particle size of the aluminate phosphor varies depending on the intended device, but usually has a high coatability in the range of about 1 to 20 μm. When used for a fluorescent lamp, usually a range of about 1 to 10 μm is preferably used.

The shape of the particles of the aluminate phosphor varies depending on the purpose, and may be, for example, a flat plate, a hexagonal plate, or the like.
Examples include a spherical shape, a needle shape, and a cubic shape having a relatively sharp angle. When used in fluorescent lamps and displays, when the synthesized aluminate phosphor is fixed to the device, it is heated in the air at, for example, 600 to 800 ° C., so that it oxidizes from the surface and the brightness decreases. Although There is known from our experiments, by using a spherical or substantially aluminate phosphor spherical, with respect to the heating of a specific surface area of the phosphor is small <br/> a Redirecting a aerial, decrease in brightness Has been found to be very low and suitable from our experiments. Aluminum oxide as raw material for spherical aluminate phosphor
The beam, for example, aluminum oxide such as alpha alumina
Exposing the bromide in hot plasma and the like, and those spheroidized than <br/> to quenching, such as those spheroidized by self firing method as in Admatechs Co. high purity spherical alumina "Admafine" is No. Also, as the aluminum oxide as a raw material of the substantially spherical aluminate phosphor, polyhedron such as octahedron was formed by gasification and then crystallization, such as alumina “Sumicorundum” manufactured by Sumitomo Chemical Co., Ltd. Aluminum oxide and the like can be mentioned.

It is preferable to use a spherical or substantially spherical phosphor for a fluorescent lamp, a display, or the like, because the transmittance of visible light increases and the light extraction efficiency increases. When the production method of the present invention is employed, for the above-described reason, if aluminum oxide having substantially the same particle size and shape as the target aluminate phosphor is used, the target particle size and shape can be reduced. An aluminate phosphor can be obtained.

In the method for producing an aluminate phosphor of the present invention, the alkaline earth metal compound is a barium compound or a magnesium compound containing no fluorine atom in the molecule, and the rare earth compound contains a fluorine atom. It is a europium compound not contained in the molecule, and the aluminate phosphor is represented by the general formula (Ba _1-w , Eu _w ) Mg _x Al _y O _z, provided that 0.03 ≦ w ≦ 0.3, 0.8 ≦ x ≦ 1.2,
By using a phosphor represented by 8 ≦ y ≦ 12 and 14 ≦ z ≦ 20, europium can be efficiently emitted, and a phosphor which emits blue light with high luminance is preferable.

In order to make the composition of the aluminate phosphor obtained as described above, the same ratio as the atomic number ratio of the alkaline earth metal element, the rare earth metal element and the aluminum element represented by the above chemical formula is used. It can be obtained by blending a raw material of an alkaline earth metal compound, a rare earth compound and aluminum oxide so as to include an alkaline earth metal element, a rare earth metal element and an aluminum element, and firing the mixture under a reducing atmosphere as described above. . The same applies to other compositions.

In the method for producing an aluminate phosphor of the present invention, the alkaline earth metal compound is a magnesium compound containing no fluorine atom in the molecule, and the rare earth compound is free from a fluorine atom in the molecule. a cerium compound and a terbium compound, aluminate phosphor, the general formula _{(Ce 1-w, Tb w} ) Mg x Al y O z where, 0.03 ≦ w ≦ 0.6, 0.8 ≦ x ≦ 1.2,
By using an aluminate phosphor represented by 9 ≦ y ≦ 13, 15 ≦ z ≦ 23, terbium can be efficiently emitted, and a phosphor emitting green light with high luminance can be obtained, which is preferable. .

In the method for producing an aluminate phosphor of the present invention, the alkaline earth metal compound is a strontium compound containing no fluorine atom in the molecule, and the rare earth compound is free from a fluorine molecule in the atom. A europium compound, wherein the aluminate phosphor is represented by the general formula (Sr _{4 (1-w)} , Eu _4w ) Al _x O _y, where 0.01 ≦ w ≦ 0.6, 11 ≦ x ≦ 17, 2
With 0 ≦ y ≦ 30, in the represented Ru Phosphors, it is possible to europium efficiently emit light, it is possible to obtain a phosphor emitting blue-green with high luminance preferred.

[0034]

(Example 1) Method for producing aluminate phosphor (hereinafter abbreviated as BAM phosphor) represented by chemical formula (Ba _0.9 , Eu _0.1 ) MgAl ₁₀ O ₁₇ Hereinafter, a first embodiment of the present invention will be described. This will be described with reference to Table 1. Table 1 kind of raw material in the synthesis of B AM phosphor, the weight percent ratio of Oyo BiHara fee.

[0035]

[Table 1]

[0036] Using barium carbonate as alkaline earth metal compounds and basic magnesium carbonate, alpha alumina and <br/> aluminum oxide, europium oxide as a rare earth compound.

The raw materials having a weight percentage ratio shown in Table 1 were mixed and pulverized in a mortar, a ball mill, or the like, and fired in a tubular furnace using a mixed gas of nitrogen gas and hydrogen gas. The flow rate of the nitrogen gas was 380 ml / min, the flow rate of the hydrogen gas was 20 ml / min, and the hydrogen concentration was 5% by volume. When the temperature was increased at a rate of 400 ° C./hour and calcined at 1700 ° C. for 2 hours, the temperature was decreased at 400 ° C./hour to synthesize a BAM phosphor. The concentration of hydrogen gas at the time of sintering is sufficient if the concentration is 0.1% by volume or more because hydrogen has a strong reducing power. The concentration of hydrogen gas is preferably 10 vol% or less than to inhibit the synthesis of I Ri B AM phosphor becomes larger than 10% by volume to its strong reducing power <br/>. Further, when the baking time is at a high temperature of 1600 ° C. or higher, the diffusion reaction proceeds rapidly, and thus the synthesis is completed when the baking time is 5 minutes or longer.

In the above-mentioned BAM phosphor and its manufacturing method, high crystallization will be described with reference to FIG.

In FIG. 1, the vertical axis is the strongest peak 107 in the X-ray diffraction spectrum of the crystal of the BAM phosphor.
The half width of the surface.

Here, the half width of the X-ray diffraction spectrum
Represents the crystallinity of the B AM phosphor, the half width is small and has high crystallinity, the higher the crystallinity thereof, in applying the B AM phosphor device such as a fluorescent lamp or a display, heat treatment that the deterioration of the brightness of by that B AM phosphor is small it is known by our experiments.

The horizontal axis represents the reciprocal of the firing temperature (K) at the time of synthesis of the BAM phosphor. The scale of the sintering temperature (° C.) is provided on the upper side of FIG. 1 for reference. Point indicated by △ mark in FIG. 1 is actually measured data of the half-value width of the X-ray diffraction spectrum of B AM phosphor of the present embodiment. In FIG. 1, the solid line a is a linear function obtained by fitting the measured data of the half-value width of the X-ray diffraction spectrum using the least square method. Here, the half value width of the 107 plane of the X-ray diffraction spectrum of the conventional BAM phosphor using a fluorine compound is shown by a broken line b in the graph of FIG. 1 for comparison.

As shown by the solid line a in FIG. 1, as the firing temperature of the BAM phosphor of this embodiment increases, the half-value width of the X-ray diffraction spectrum decreases,
When the temperature exceeds 0 ° C., the X-ray diffraction spectrum of the BAM phosphor using the fluorine compound becomes smaller than the half-value width of 107 plane (broken line b). That is, the crystallinity is higher than that of a conventional BAM phosphor using a fluorine compound as a reaction accelerator.

Further , it has been found by our experiments that the BAM phosphor melts at a temperature higher than 2000 ° C.
Therefore, in FIG. 1, in the region higher than 2000 ° C., the half width of the X-ray diffraction spectrum is actually saturated.

Thus, the temperature is higher than 1600 ° C. and 2000 ° C.
By firing in the following high-temperature reducing atmosphere, the reaction is promoted, this to improve the crystallinity without using fluorine compounds
Accordingly , a high-luminance BAM phosphor can be obtained.

(Example 2) Method for producing aluminate phosphor (hereinafter abbreviated as CAT phosphor) represented by chemical formula (Ce _0.67 , Tb _0.33 ) MgAl ₁₁ O ₁₉ Hereinafter, a second embodiment of the present invention will be described. This will be described with reference to Table 2. Table 2 kinds of raw materials in the synthesis of C AT phosphor, the weight percent ratio of及BiHara fee.

[0046]

[Table 2]

Basic magnesium carbonate was used as an alkaline earth metal compound, alpha alumina was used as aluminum oxide, and cerium oxide and terbium oxide were used as rare earth compounds.

The raw materials having the weight percentage ratios shown in Table 2 were mixed in a mortar, ball mill, or the like, and fired in a tubular furnace using a mixed gas of nitrogen gas and hydrogen gas. The flow rate of nitrogen gas is 3
The flow rate of hydrogen gas was 20 ml / min, and the concentration of hydrogen gas was 5%. When the temperature was increased at a rate of 400 ° C./hour and calcined at 1700 ° C. for 2 hours, the temperature was decreased at 400 ° C./hour, whereby a CAT phosphor was synthesized.

The high crystallization in the above-described CAT phosphor and its manufacturing method will be described with reference to FIG.

In FIG. 2, the vertical axis represents the strongest peak in the X-ray diffraction spectrum of the crystal of the CAT phosphor.
It is a half width of 14 surfaces.

[0051] As in Example 1, the half-value width of the X-ray diffraction spectrum indicates the crystallinity of the C AT phosphor, the half width is small, the crystallinity is high, higher the crystallinity thereof,
It luminance degradation of the C AT phosphor that by the heat treatment at the time of applying the C AT phosphor device such as a fluorescent lamp or a display is small, have been found by our experiments.

The horizontal axis is the reciprocal of the firing temperature (K) during the synthesis of the CAT phosphor. The firing temperature (° C) is shown in the upper part of FIG.
The scale is given for reference. In FIG. 2, the points indicated by ● are the measured data of the half width of the X-ray diffraction spectrum of the CAT phosphor. In FIG. 2, the solid line a is a linear function obtained by fitting the measured data of the half-width of the X-ray diffraction spectrum using the least square method. CA obtained here in the conventional method using a fluorine compound
The half width of the X-ray diffraction spectrum of the T phosphor on the 114 plane is shown by a broken line b in the graph of FIG. 2 for comparison. As is clear from FIG. 2, as the firing temperature of the CAT phosphor of this example was increased, the half-width of the X-ray diffraction spectrum was reduced, and when it exceeded 1600 ° C., the CAT phosphor of the conventional method using a fluorine compound was used. It becomes smaller than the half width (dashed line b) of the 114 plane of the X-ray diffraction spectrum of the body. That is, the crystallinity is higher than that of a conventional CAT phosphor using a fluorine compound as a reaction accelerator.

It has been found from our experiments that the CAT phosphor of this embodiment melts at a temperature higher than 2000 ° C., similarly to the BAM phosphor of the first embodiment. Therefore, in FIG. 2, in the region higher than 2000 ° C., the half width of the X-ray diffraction spectrum is actually saturated.

Thus, the temperature is higher than 1600 ° C. and 2000 ° C.
By firing in the following high-temperature reducing atmosphere, the reaction is promoted, this to improve the crystallinity without using fluorine compounds
Thus , a high-luminance CAT phosphor can be obtained.

(Example 3) Method for producing aluminate phosphor having the same or substantially the same particle size as aluminum oxide and having the same or substantially the same shape Next, referring to the drawings, for a third embodiment of the present invention. I will explain while.

FIG. 3 shows the aluminate phosphor according to the third embodiment of the present invention in which spherical alumina having a particle diameter of 10 μm is used as a raw material.
It is a schematic diagram which shows the reaction state in the manufacturing process when used as aluminum oxide . Note that this embodiment is also described using a BAM phosphor as in the first embodiment. The synthesis process is the same as in the first embodiment.

[0057] In FIG. 3, the manufacturing process of the A Rumin phosphor is proceed in FIG 3 (A) to (D). In FIG. 3 (A) shows the alpha alumina 11 alone state of spherical particles as a raw material of BAM phosphor, (B) a raw material Der luer Alpha alumina 11 of a BAM phosphor, barium carbonate 12, It shows the state of a mixture in which basic magnesium carbonate 13 and europium oxide 14 are mixed.
(C) is a schematic diagram of a state during firing in the firing step of the mixture of ( B). (D) is a synthesized BAM phosphor 1
5 is shown. The synthesis process is the same as in Example 1.

Spherical alpha alumina 1 having a particle size of 10 μm
1 (FIG. 3A) is mixed and ground with barium carbonate 12, basic magnesium carbonate 13, and europium oxide 14, which are other raw materials. However, although other raw materials are pulverized, the alpha alumina 11 is hard to be pulverized due to its high hardness, and there is almost no change in the particle size and shape (FIG. 3B). During firing at a temperature of 1600 ° C. or more, barium carbonate 12, basic magnesium carbonate 13, and europium oxide 14, which are other raw materials, are diffused and mixed into the alpha alumina 11 ((C) in FIG. 3). A spherical BAM phosphor 15 having the same particle size (10 μm) and the same shape as the alpha alumina 11 was obtained ((D) in FIG. 3).

FIG. 4 shows the result of examining the dependence of the synthesized BAM phosphor on the particle diameter of the alumina raw material. In FIG. 4, the horizontal axis represents the average particle diameter of alpha alumina as a raw material, and the vertical axis represents the average particle diameter of the synthesized BAM phosphor.
FIG. 4 shows that the average particle size of the BAM phosphor depends on the average particle size of alpha alumina as a raw material.

The aluminate phosphor has a particle size of 15 μm.
FIG. 5 shows electron microscope photographs of the results of observation with an electron microscope before and after sintering in the case where alumina having a square shape of m was used as the raw material aluminum oxide . In FIG. 5, (A), (B), and (C) show (A), (B),
The state in the step corresponding to (D) is shown. While using the alpha alumina angular average particle size 15μm here, by comparing the 5 (A) and (C), that the particle size of the A Alpha alumina, and angular shape is maintained I understand.

As described above, by selecting the particle size and shape of aluminum oxide, an aluminate phosphor having an arbitrary particle size and shape can be obtained without using a fluorine compound.

In Examples 1 and 3, (B
Although the explanation has been made using the aluminate phosphor represented by a _0.9 , Eu _0.1 ) MgAl ₁₀ O ₁₇ , the region where a single crystal is generated is represented by the general formula (Ba _{1 -w} , Eu _w ) Mg
_x Al _y O _z , where 0.03 ≦ w ≦ 0.3, 0.8 ≦
A composition range represented by x ≦ 1.2, 8 ≦ y ≦ 12, and 14 ≦ z ≦ 20 is desirable. In the above general formula,
0.03 ≦ w ≦ 0.3, 0.97 <x <1.03,
If 9.7 <y <10.3 and 16 <z <18, the stability is particularly high against oxidation by heat, and the luminance by the heating process in the air generated when the phosphor is applied to the device is increased. An aluminate phosphor with extremely small deterioration can be obtained, which is more preferable.

In the above description, barium carbonate and basic magnesium carbonate are used as alkaline earth metal compounds as raw materials of the BAM phosphor, but other alkaline earth metal compounds such as barium nitrate and barium chloride may be used. Good. Although using alpha alumina as aluminum oxide, may be used other aluminum oxide, such as gamma alumina.

Further, a calcium compound or a strontium compound may be added as the alkaline earth metal compound. Further, a manganese compound such as manganese oxide may be added to further increase the luminance.

In Example 2, the chemical formula (Ce
_0.67, Tb _0.33) showed the example represented by MgAl ₁₁ O _19, as the region capable single crystal of the composition, the general formula _{(Ce 1-w, Tb w} ) Mg x Al y O z, However, 0.0
3 ≦ w ≦ 0.6, 0.8 ≦ x ≦ 1.2, 9 ≦ y ≦ 1
It is preferable that the composition range is represented by 3, 15 ≦ z ≦ 23. In the above general formula, 0.03 ≦ w
≦ 0.6, 0.97 <x <1.03, 10.7 <y
In the case of <11.3, 18 ≦ z ≦ 20, the stability is particularly high with respect to oxidation by heat, and the deterioration of luminance due to the heating step in the air which occurs when the phosphor is applied to the device is extremely low. A small aluminate phosphor can be obtained,
More preferred.

In the first to third embodiments, (B
a _0.9 , Eu _0.1 ) MgAl ₁₀ O ₁₇ or (Ce
_{An example of 0.67} , Tb _0.33 ) MgAl ₁₁ O ₁₉ is shown, and the phosphor has a chemical formula of (Sr, Eu) ₄ Al ₁₄ O ₂₅ , (S
The same effect can be obtained with a phosphor having a composition such as (r, Eu) Al ₂ O ₄ or (Ca, Eu) Al ₂ O ₄ .

[0067] The shape of the alpha alumina 11 in Example 3, plate-like, hexagonal plate-shaped, spherical, it may also be any acicular Iga, spherical or when is a substantially spherical aluminate phosphor It is more preferable to obtain an aluminate phosphor with extremely small deterioration in luminance with respect to heating in the atmosphere during coating.

[0068]

The method for producing the aluminate phosphor of the present invention.
According to the above, the particle size and shape of the desired aluminate phosphor are the same.
One particle size or almost the same particle size, same shape or almost same shape
By using a raw aluminum compound in the form of
Even without using a compound, the particle size and shape of the aluminate phosphor
You can control the shape. Easy control of particle size
Method for producing novel aluminate phosphor, control of particle shape
Can provide a method for manufacturing an aluminate phosphor that is easy to use.
You.

Further , by setting the reducing atmosphere to a preferred embodiment of the present invention, which is a reducing atmosphere composed of a mixed gas of hydrogen gas and nitrogen gas, a relatively inexpensive and desirable reducing atmosphere can be realized.

[0070] The concentration of the hydrogen gas in the reducing atmosphere of a mixed gas of hydrogen gas and nitrogen gas, by a preferred embodiment of the present invention which is more than 0.1 vol% 10 vol% or less, aluminates It is preferable that the synthesis of the phosphor is performed well without being hindered.

[0071] Further, with the preferred embodiment of the present invention baked formation time is 5 minutes or more, the synthesis of aluminate phosphor is completely performed, preferably can be obtained aluminate phosphor of good quality .

[0072] Further, A Rumin phosphor has the general formula _{(Ba 1-w, Eu w} ) Mg x Al y O z where 0.03 ≦ w ≦ 0.3, 0.8 ≦ x ≦ 1.2 ,
By adopting a preferred embodiment of the present invention having a composition represented by 8 ≦ y ≦ 12 and 14 ≦ z ≦ 20, europium can be efficiently emitted, and a phosphor that emits blue light with high luminance can be obtained. This is preferable.

[0073] Further, A Rumin phosphor has the general formula _{(Ce 1-w, Tb w} ) where _{Mg x Al y O z, 0.03} ≦ w ≦ 0.6, 0.8 ≦ x ≦ 1. 2,
By providing a preferred embodiment of the present invention having a composition represented by 9 ≦ y ≦ 13 and 15 ≦ z ≦ 23, it is possible to obtain a phosphor that can efficiently emit terbium and emit green light with high luminance. Is preferred.

[0074] Further, A Rumin phosphor has the general formula _{(Sr 4 (1-w)} , Eu 4w) Al x O y where, 0.01 ≦ w ≦ 0.6, 11 ≦ x ≦ 17, 2
By adopting a preferred embodiment of the present invention having a composition represented by 0 ≦ y ≦ 30, europium can be efficiently emitted, and a phosphor that emits blue-green light with high luminance is preferably obtained.

[0075] In addition, acid which is a raw material of A Rumin phosphor
By adopting a preferred embodiment of the present invention in which the particle size of aluminum halide is 1 μm or more and 20 μm or less, it is possible to provide a method for producing an aluminate phosphor excellent in coatability when applied to a device.

The shape of the aluminum oxide is spherical or
In a preferred embodiment of the present invention, which has a substantially spherical shape, the specific surface area of the phosphor is reduced, and the degree of decrease in luminance with respect to heating in the atmosphere during the application of the phosphor is extremely low. It is preferable because an acid salt phosphor can be obtained. Further, by using a fluorescent lamp or a display or the like spherical or A Le <br/> amine acid salt phosphors substantially spheroidized, increased visible light transmittance, the light extraction efficiency is increased, excellent An aluminate phosphor can be provided.

[0077] Further, at least one alkaline earth metal compound containing no fluoride atom in the molecule, oxides of alkaline earth metals, carbonates, basic carbonates, selected from the group consisting of nitrates and chlorides By the preferred embodiment of the present invention, which is a kind of alkaline earth metal compound, these alkaline earth metal compounds are relatively inexpensive and easily available, and are relatively stable compounds, so that they are easy to handle. Yes and preferred.

[0078] Further, the rare earth compound containing no fluoride atom in the molecule, oxides of rare earth elements, preferably of the present invention is a carbonate, nitrate and at least one rare earth compound selected from the group consisting of chloride According to the embodiment, these rare earth compounds are relatively inexpensive and easily available among rare earth compounds, and are relatively stable compounds, so that they are easy to handle and are preferable .

[Brief description of the drawings]

FIG. 1 is a characteristic diagram showing the relationship between the firing temperature and the crystallinity of an aluminate phosphor obtained according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing the relationship between the firing temperature and the crystallinity of an aluminate phosphor obtained according to a second embodiment of the present invention.

Schematic diagram showing a reaction state of the manufacturing process in the case of Figure 3 with spherical alumina of a third embodiment of the present invention.

FIG. 4 is a characteristic diagram showing the dependency correlation of the phosphor of the third embodiment of the present invention with the particle size of the alumina raw material.

FIG. 5 is a sketch drawing of an electron micrograph showing an observation result of a reaction state in a manufacturing process when angular alumina is used as a raw material aluminum oxide in a third embodiment of the present invention.

[Description of Signs] 11 Alpha alumina particles 12 Barium carbonate particles 13 Basic magnesium carbonate particles 14 Europium oxide particles 15 BAM phosphor particles

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeta Lighting 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Takeshi Nishiura 1006 Oji Kadoma Kadoma City, Osaka Matsushita Electric Industrial Co. ( 72) Inventor Shigeru Horii 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Tomizo Matsuoka 1006 Kadoma Odari Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (14)

[Claims] An alkaline earth metal compound containing no fluorine atom in a molecule, a rare earth compound containing no fluorine atom in a molecule, and an aluminum compound containing no fluorine atom in a molecule are reduced in a reducing atmosphere. 2000 above 1600 ° C
A method for producing an aluminate phosphor characterized by firing at a temperature of not more than ℃. 2. The method for producing an aluminate phosphor according to claim 1, wherein the reducing atmosphere is a reducing atmosphere comprising a mixed gas of hydrogen gas and nitrogen gas. 3. The concentration of hydrogen gas in a reducing atmosphere composed of a mixed gas of hydrogen gas and nitrogen gas is 0.1% by volume or more.
3. The method for producing an aluminate phosphor according to claim 2, wherein the content is not more than% by volume. 4. The sintering time is 5 minutes or more.
3. The method for producing an aluminate phosphor according to any one of 3. 5. The alkaline earth metal compound is a barium compound or a magnesium compound containing no fluorine atom in the molecule, the rare earth compound is a europium compound containing no fluorine atom in the molecule, and the aluminate phosphor is General formula (Ba _1-w , Eu _w ) Mg _x Al _y O _z, where 0.03 ≦ w ≦ 0.3, 0.8 ≦ x ≦ 1.2,
The method for producing an aluminate phosphor according to any one of claims 1 to 4, comprising a composition represented by 8 ≦ y ≦ 12 and 14 ≦ z ≦ 20. 6. The alkaline earth metal compound is a magnesium compound not containing a fluorine atom in a molecule, the rare earth compound is a cerium compound and a terbium compound not containing a fluorine atom in a molecule, and the aluminate phosphor is generally used. formula _{(Ce 1-w, Tb w} ) Mg x Al y O z where, 0.03 ≦ w ≦ 0.6, 0.8 ≦ x ≦ 1.2,
The method for producing an aluminate phosphor according to any one of claims 1 to 4, comprising a composition represented by 9 ≦ y ≦ 13 and 15 ≦ z ≦ 23. 7. The alkaline earth metal compound is a strontium compound containing no fluorine atom in the molecule, the rare earth compound is a europium compound containing no fluorine molecule in the atom, and the aluminate phosphor is represented by the general formula (Sr _{4 (1-w)} , Eu _4w ) Al _x O _y where 0.01 ≦ w ≦ 0.6, 11 ≦ x ≦ 17, 2
5. A composition represented by the formula: 0.ltoreq.y.ltoreq.30.
The method for producing an aluminate phosphor according to any one of the above. 8. As an aluminum compound containing no fluorine molecules as atoms, which is a raw material of the aluminate phosphor, an aluminum compound having the same or substantially the same particle size as the desired aluminate phosphor is used. A method for producing an aluminate phosphor according to any one of claims 1 to 7. 9. The method for producing an aluminate phosphor according to claim 8, wherein the particle diameter of the aluminum compound is 1 μm or more and 20 μm or less. 10. An aluminum compound having no fluorine atom in its molecule, which is a raw material of an aluminate phosphor, is made of an aluminum compound having the same shape or substantially the same shape as that of a desired aluminate phosphor. A method for producing an aluminate phosphor according to claim 1. 11. The method for producing an aluminate phosphor according to claim 10, wherein the shape of the aluminum compound is spherical or substantially spherical. 12. The alkaline earth metal compound containing no fluorine atom in the molecule, at least one selected from the group consisting of alkaline earth metal oxides, carbonates, basic carbonates, nitrates and chlorides. The method for producing an aluminate phosphor according to any one of claims 1 to 4, wherein the alkaline earth metal compound is an alkaline earth metal compound. 13. The rare earth compound containing no fluorine atom in the molecule is at least one rare earth compound selected from the group consisting of oxides, carbonates, nitrates and chlorides of rare earth elements. The method for producing an aluminate phosphor according to any one of the above. 14. The aluminum compound containing no fluorine atom in the molecule is at least one aluminum compound selected from the group consisting of aluminum oxides, chlorides, nitrates, sulfates and alkoxides.
5. The method for producing an aluminate phosphor according to any one of items 1 to 4.