JP3268431B2 - Method for producing aluminate-based phosphor having afterglow characteristics - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aluminate having an afterglow characteristic which is used for a phosphorescent material or the like which is excited by ultraviolet light or visible light and exhibits a long time (several tens of minutes to several hours). The present invention relates to a method for producing a phosphor.

[0002]

2. Description of the Related Art Conventionally, a self-luminous luminous paint in which a radioactive substance is added to a phosphor has been used for nighttime display and luminous timepieces. Recently, applications of phosphorescent phosphors having long-term persistence without using radioactive substances have been widely studied. As the phosphorescent phosphor, for example, europium-activated strontium aluminate has been mainly studied (Japanese Patent No. 2543825).

It is well known that the characteristics of a phosphor are affected by the primary particle diameter of the phosphor particles, and the luminous efficiency is higher when the phosphor particles are larger. It is said that afterglow luminance also increases in the phosphorescent phosphor in proportion to the primary particle diameter. Therefore, a phosphorescent phosphor having a primary particle diameter of usually 20 μm to 50 μm is used.

Further, it is well known that the emission characteristics of phosphors are greatly affected by trace impurities. Therefore, high-purity alumina powder such as high-purity high-purity α-alumina or high-purity γ-alumina is used as the main raw material for aluminate, which is the base of the aluminate-based phosphor having afterglow characteristics. It is manufactured by adding aluminum fluoride or the like as a flux during firing. These high-purity alumina powders have a fine primary particle diameter, usually 1 μm.
, And are melted during sintering by the flux to form hard agglomerated particles.

On the other hand, the hard agglomerated particles can be reduced by pulverization, but the particle size distribution after the pulverization becomes wide due to the remaining of the agglomerated particles and generation of fine particles accompanying the pulverization. Therefore, the phosphor synthesized using these high-purity alumina powders is a powder having a wide particle size distribution from submicron to about 100 μm.

That is, the aluminate-based phosphor having the afterglow characteristic uses a fine high-purity alumina raw material of less than 1 μm as a raw material alumina, and grows into phosphor particles of submicron to about 200 μm by high-temperature firing. for that reason,
The phosphor particles after firing have a wide particle size distribution and are strongly aggregated, and need to be pulverized. In addition, it is essential to remove fine particles and coarse particles by classification. as a result,
There were major problems such as degradation of afterglow characteristics due to destruction of primary particles and non-uniformity of crystallinity due to pulverization, and low yield as phosphor particles.

[0007] Accordingly, small particle (for example, 10 µm or less) aluminate-based phosphors which are easy to grind, have few fine particles, have excellent afterglow characteristics, and have high afterglow characteristics with a high product yield have been obtained. Not.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides a method for producing an aluminate-based phosphor having afterglow characteristics that hardly impairs the particle diameter derived from the raw material alumina powder, thereby obtaining the raw material alumina powder. An object is to obtain an aluminate-based phosphor having afterglow characteristics. Further, even if the powders adhere to each other, a method for producing an aluminate-based phosphor having afterglow characteristics, which is easy to pulverize and has a small amount of fine particles, has excellent afterglow characteristics, and has a high product yield. The purpose is to:

[0009]

According to the first aspect of the present invention, there is provided a method for producing an aluminate-based phosphor having afterglow characteristics, comprising a general formula: aMO.Al ₂ O ₃ (M is strontium (Sr ), Calcium (Ca),
At least one selected from the group consisting of barium (Ba)
A compound comprising at least one metal element, a is from 0.5 to 1.
On the composite oxide substrate shown in 1), a user as an activator is added.
Molar% of metal element represented by M by ropium (Eu)
In the range of 0.002% to 20%
Lanthanum (La), cerium (Ce), plastic
Theodium (Pr), Neodymium (Nd), Samarium
(Sm), gadolinium (Gd) terbium (Tb),
Dysprosium (Dy), Holmium (Ho), Erbi
(Er), thulium (Tm), ytterbium (Y
b), lutetium (Lu), manganese (Mn), tin
(Sn), bismuth (Bi), scandium (Sc)
A metal wherein at least one element of the group consisting of:
0.002% or more and 20% or less in mole% based on the element
Of aluminate-based phosphor with improved afterglow properties
In this case, the raw material alumina has a primary particle diameter of 0.3.
α having a crushed surface of not less than μm and not more than 30 μm
-Using alumina powder, the raw material alumina powder, selected
After mixing the metal element, activator and coactivator
At the time of firing, firing at a predetermined temperature without adding a flux
It is a method to achieve .

[0010]

According to the second aspect of the present invention, a method for producing an aluminate-based phosphor having afterglow characteristics is represented by the general formula: (Sr, Eu, Pb, Dy) O.y (Al, Bi) ₂ Eu ^{2+ represented by} O ₃ (provided that 0.83 ≦ y ≦ 1.67)
In synthesizing an aluminate-based phosphor having an afterglow characteristic based on an activated strontium-aluminate-based phosphor , the primary particle diameter of the raw material alumina is 0.3 μm.
Α-A having substantially no crushed surface of 30 μm or less
Using lumina powder, during the firing after mixing the raw material alumina powder, the selected metal element, activator and co-activator, firing at a predetermined temperature without adding a flux How to

[0012]

According to a third aspect of the present invention, there is provided a method for producing an aluminate-based phosphor having an afterglow characteristic, comprising a method represented by the following general formula: (Sr, Eu, Dy) O.Al ₂ O ₃ Upon synthesizing aluminate phosphor having a light characteristics, as a raw material of alumina, using α- alumina powder having no following substantially fractured surface 30μm in primary particle size of 0. 3 [mu] m or more, the raw material alumina powder And a method of firing at a predetermined temperature without adding a flux when firing after mixing the selected starting metal element of the general formula, an activator and a coactivator.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The present invention uses α-alumina powder having a predetermined average particle size and particle size distribution as a raw material alumina, and melts the raw material α-alumina powder by flux during firing after mixing the raw materials. Since it is a method of firing without being carried out, an aluminate-based phosphor having a persistence characteristic of a particle diameter of a size derived from the raw material alumina powder can be obtained. That is,
By sintering without melting with a flux, there is partial melting of the adjacent α-alumina powder, but the entire α-alumina powder is baked without melting. Therefore, an aluminate-based phosphor having an afterglow characteristic that maintains the particle diameter derived from the raw material α-alumina powder can be obtained.

Therefore, by selecting a raw material alumina having a desired average particle diameter and a desired particle size distribution, the afterglow characteristics due to the destruction of the primary particles due to the pulverization and the non-uniform crystallinity are reduced, and An aluminate-based phosphor having afterglow characteristics without problems such as a low yield as phosphor particles is obtained.

More specifically, the aluminate-based phosphor having the afterglow characteristic obtained by the production method of the present invention is fired without being melted by the flux, so that the adjacent α-phosphorus can be obtained. Although the alumina powder is partially melted, the whole α-alumina powder is fired without melting.
Regarding this, observation with an electron microscope showed that the raw material α-
Differences were found in the phosphors obtained depending on the type of alumina powder and the size of the primary particle diameter.

When a general α-alumina powder having a substantially crushed surface is fired without adding a flux at the time of firing, not all of the raw material α-alumina powder is melted, but the crushed surface Are partially melted, and the fired crystal is in a so-called “rounded corner” state, and the phosphor is fired while almost maintaining the appearance of the raw material α-alumina powder. In particular, when the primary particle diameter of the raw material α-alumina powder is smaller, adjacent particles of the α-alumina powder are fused with each other to form droplet-shaped particles having a primary particle diameter of about several μm. It is fired in a state where particles of about several μm are adhered by a weak force.

Since the obtained aluminate-based phosphor having the afterglow characteristic is fired in a state where the fused bodies are bonded to each other with a weak force, it is applied with a force enough to loosen the bonding between the fused bodies. It easily falls apart. Therefore, an aluminate-based phosphor having excellent afterglow characteristics due to easy disintegration and small number of fine particles and high product yield can be easily obtained.

On the other hand, when the primary particle diameter is 0.3 μm or more, 30
There is no corner in α-alumina powder having substantially no crushed surface of μm or less. Therefore, if the primary particle diameter of the raw material α-alumina powder is smaller, adjacent particles of the α-alumina powder fuse with each other to form droplet-shaped particles having a primary particle diameter of about several μm. It is fired in a state where particles of about several μm are adhered by a weak force. For more information,
If the particle diameter of the raw material α-alumina powder is smaller than about 1 μm, a part of the surface layer of adjacent α-alumina powder particles is fused with each other to form particles having a primary particle diameter of about several μm,
Further, the particles are fired in a state where the fused particles having a size of about several μm are adhered by a weak force. On the other hand, the raw material α-
If the primary particle diameter of the alumina powder is larger than about 1 μm, the particles of the raw material α-alumina powder maintain the particle diameter as they are without melting, and the particles adjacent to each other are bonded with a weak force. Fired.

The obtained aluminate-based phosphor having the afterglow characteristic is obtained by using a general α-alumina powder in which a part of the particle surface layer of the raw material α-alumina powder has a substantially crushed surface as described above. Since the particles are fired in a state where they are bonded with a much weaker force than the particles, the particles are easily separated with a weaker force enough to loosen the adhesion between the particles, and the particles are easily crushed and the generation of fine particles is small. Accordingly, the aluminate-based phosphor having excellent afterglow properties and high product yield and having high afterglow properties can be easily obtained because the crushing is extremely easy and the number of fine particles is small.

As the aluminate-based phosphor having a specific afterglow characteristic produced in the present invention, any phosphor containing an aluminate in a mother crystal may be used. For example, Patent No. 2543
An aluminate-based phosphor having afterglow characteristics of several tens of minutes to several hours described in Japanese Patent Application Laid-Open No. 825 and Japanese Patent Application No. 7-112574 is exemplified.

Specifically, a general formula aMO.Al ₂ O ₃ (M is strontium (Sr), calcium (Ca),
At least one selected from the group consisting of barium (Ba)
A compound comprising at least one metal element, a is from 0.5 to 1.
In the composite oxide substrate shown in 1), mol% of europium (Eu) as an activator with respect to a metal element represented by M is added.
And at least 0.002% to 20%, and lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), gadolinium (Gd) terbium as a co-activator. (Tb),
Dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Y
b), at least one element of the group consisting of lutetium (Lu), manganese (Mn), tin (Sn), bismuth (Bi), and scandium (Sc) is 0.002 in mol% with respect to the metal element represented by M. Aluminate-based phosphors having afterglow characteristics added in an amount of from 20% to 20% are exemplified.

For example, an aluminate-based phosphor having an afterglow characteristic is prepared by adding europium as an activator to a composite oxide substrate represented by the general formula aMO.Al ₂ O ₃ and at least one selected from dysprosium and neodymium. In the case where the metal element is added as a co-activator, a is preferably in the range of 0.5 to 1.1.

Specifically, an aluminate-based phosphor having an afterglow characteristic is prepared by adding europium as an activator to a composite oxide substrate represented by the general formula aSrO.Al ₂ O ₃ , and further co-activating with dysprosium. In the case of a compound added as an agent, a is preferably in the range of 0.9 to 1.1. Further, an aluminate-based phosphor having an afterglow characteristic is a compound obtained by adding europium as an activator and neodymium as a coactivator to a composite oxide substrate represented by the general formula aCaO.Al ₂ O ₃ . In this case, a is from 0.9 to 1.
It is preferably in the range of 1.

Further, for example, an aluminate-based phosphor having an afterglow property is used as an activator for europium and a dysprosium as a coactivator for a composite oxide substrate represented by the general formula aSrO.Al ₂ O _3. In the case of the added compound, the amount of europium added is from 0.01a to 0.1a,
It is preferable that the added amount of dysprosium is in the range of 0.02a to 0.2a. For example, an aluminate-based phosphor having an afterglow characteristic is a composite oxide substrate represented by the general formula aCaO.Al ₂ O ₃ , in which europium is used as an activator.
Further, in the case of a compound to which neodymium is added as a coactivator, the amount of europium added is from 0.01a to 0.1.
a, the amount of neodymium is preferably in the range of 0.02a to 0.2a. Addition of an activator in a smaller amount or a larger amount than these preferable ranges is not preferable because it lowers the luminance.

Lanthanum (La) as a co-activator,
Cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), gadolinium (G
d) Terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (T
m), ytterbium (Yb), lutetium (Lu),
Manganese (Mn), tin (Sn), bismuth (Bi),
May be 0. 1a added from 0. 001a in the composite oxide substrate represented at least one metal element of the group consisting of scandium (Sc) by the formula aMO · Al ₂ O _3.

Further, a general formula: (Sr, Eu, Pb, Dy) O.y (Al, Bi) ₂ O
₃ (where 0.83 ≦ y ≦ 1.67) is exemplified by an aluminate-based phosphor having an afterglow characteristic, which is based on a Eu ²⁺ -activated strontium-aluminate-based phosphor.

In the aluminate phosphor having the afterglow characteristic, the range of y is 0.83 ≦ y ≦ 1.67, and the composition ratio (mol) of each element is 0.016 ≦ Eu ≦ 0.0
33, 0.006 ≦ Pb ≦ 0.017, 0.050 ≦ D
y ≦ 0.133, 1.655 ≦ Al ≦ 3.334,0.
0030 ≦ Bi ≦ 0.0100, and more preferably, 1.00 ≦ y ≦ 1.15, 0.020 ≦ E
u ≦ 0.023, 0.010 ≦ Pb ≦ 0.011, 0.
05 ≦ Dy ≦ 0.133, 1.994 ≦ Al ≦ 2.29
64, 0.0036 ≦ Bi ≦ 0.006. As a more preferred embodiment, y = 1, 0.017 ≦ Eu ≦ 0.
03, 0.008 ≦ Pb ≦ 0.017, 0.08 ≦ Dy
≦ 0.11, 1.994 ≦ Al ≦ 1.9964, 0.0
036 ≦ Bi ≦ 0.006.

It is to be noted that a composition in which several mol% (preferably 1.3% to 2.6 mol%) of strontium (Sr) of the aluminate-based phosphor having the afterglow characteristic is substituted with zinc is used. May be.

The α-alumina powder having a predetermined average particle size and a predetermined particle size distribution used in the present invention takes into consideration the average particle size and the particle size distribution required for an aluminate-based phosphor having afterglow characteristics. Selected. As the α-alumina powder, a general α-alumina powder having a substantially crushed surface can be used as long as it has the required average particle size and particle size distribution. In addition, the primary particle diameter is 0.3.
α having a crushed surface of not less than μm and not more than 30 μm
-Alumina powder can be used. This α-alumina powder having substantially no crushed surface is sold by Sumitomo Chemical Co., Ltd. under the trade name of Advanced Alumina, and has almost no aggregated particles and a sharp particle size distribution.

Strontium constituting the aluminate,
Compound powders such as calcium, zinc, lead or bismuth include oxides, hydroxides, carbonates, nitrates,
Those which can be decomposed at high temperature to become oxides, such as halides, can be used.

Raw materials such as europium as an activator for generating luminescence and dysprosium and neodymium as co-activators include oxides, hydroxides, carbonates, nitrates, and halides at high temperatures. Those that can be used as oxides can be used.

These materials are mixed using a ball mill, a V-type mixer or the like, and then fired at 1100 to 1800 ° C. for several hours. Further, the product obtained by the above method is crushed using a ball mill, an automatic mortar, a jet mill or the like, and then classified if necessary.

[0034]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Various measurements in the present invention were performed as follows. 1. Characteristic evaluation of α-alumina powder (1) The primary particle size of α-alumina powder is 80 to 100 particles from a SEM (scanning electron microscope, manufactured by JEOL Ltd .: T-300) photograph of α-alumina powder. Was selected and subjected to image analysis to determine the average value of the circle equivalent diameter. The equivalent circle diameter is a value converted into the diameter of a perfect circle having the same area. (2) The average particle diameter (D50) and particle size distribution (D90 / D10) of the α-alumina powder were measured using a master sizer (manufactured by Malvern Co.) using a laser scattering method as a measurement principle. (3) The specific surface area of the α-alumina powder is measured by the BET method. (4) The purity analysis of the α-alumina powder was performed using an emission spectrometer (CQM-75 manufactured by Shimadzu Corporation). (5) The particle shape of the α-alumina powder was photographed using a scanning electron microscope (manufactured by JEOL Ltd .: T-220A).

2. Evaluation of Characteristics of Aluminate Phosphor Having Afterglow Characteristics (1) The average particle diameter (D50) and particle size distribution (D90 / D10) of the aluminate phosphor having afterglow characteristics are measured by a laser scattering method. The measurement was performed using an SK laser micron sizer (manufactured by Seishin Enterprise) as a principle. (2) The particle shape of the aluminate-based phosphor having afterglow characteristics is determined by a scanning electron microscope (manufactured by JEOL Ltd .: T-22).
OA). (3) The emission intensity of the aluminate-based phosphor having the afterglow characteristic was measured using a fluorescence spectrophotometer (manufactured by Opto-Research). (4) The afterglow intensity of the aluminate-based phosphor having the afterglow characteristic was measured by the following method. The sample container was filled with the phosphor powder (diameter 38 mm, thickness 5 mm), stored in a dark place for 16 hours, and then irradiated with a fluorescent lamp installed at a height of 150 mm of the sample container for 10 minutes. After a certain period of time after the irradiation was stopped, the intensity of the afterglow was measured using a luminance meter (manufactured by Matsushita Electronics R & D Center: type 5712) and a phototube (manufactured by Hamamatsu Photonics: R).
847).

Examples (Production of High _Persistence Acid Phosphors without Using Flux) (Sr _0.988 , Eu _0.010 , Dy _0.002 ) _{O.Al 2} O
_The aluminate-based phosphor having the afterglow characteristic shown in ₃ was fired without adding a flux. The raw materials used are as follows. Strontium carbonate (SrCO ₃ ), europium oxide (Eu ₂ O ₃ ), dysprosium oxide (Dy
₂ O ₃ ), α-alumina powder (α-Al ₂ O ₃ ),

As the α-alumina powder, α-alumina powders AA-07, AA-3, and A having substantially no crushed surface
A-5 (trade name "Advanced Alumina", manufactured by Sumitomo Chemical Co., Ltd.) and RA-40 (commercially available, manufactured by Iwatani Chemical Industry Co., Ltd.) were used. The average particle size and particle size characteristics of the particle size distribution of the used raw material α-alumina powder are as shown in Table 1 below. In addition, the particle shapes of the used raw material α-alumina powder with a scanning electron microscope are shown in FIGS.

[0039]

[Table 1]

The above raw materials are thoroughly mixed in a ball mill,
After firing at 1300 ° C. for 3 hours in a reducing atmosphere, the obtained oxide was ground in an automatic mortar for 20 minutes to obtain each phosphor. In addition, as a comparative example, a commercially available aluminate-based phosphor CP-05 6C30 having afterglow characteristics (commercially available product, trade name “Picalyco”, manufactured by Chemitec Corporation) was crushed in an automatic mortar for 120 minutes. 6C30SS was used.

Table 2 shows the characteristics of the obtained phosphor such as the afterglow intensity.
Table 3 shows the average particle size and the particle size characteristics of the particle size distribution.
The afterglow intensity is a value calculated by assuming that CP-05 6C30 (commercial product, trade name “Pikarico”, manufactured by Chemitech Co., Ltd.) is crushed in an automatic mortar for 120 minutes (CP-05 6C30SS) as 100%. . In addition, the particle shapes of the obtained aluminate-based phosphor having the afterglow characteristics with a scanning electron microscope are shown in FIGS. FIG. 1 is a drawing substitute photograph of the particle shape of the aluminate-based phosphor CP-056C30 having the afterglow characteristic as compared with FIG.
FIG. 0 shows a drawing substitute photograph of the particle shape of the crushed phosphor (CP-05 6C30SS) shown in FIG. 9 with a scanning electron microscope.

[0042]

[Table 2]

[0043]

[Table 3]

As can be seen from a comparison between the raw materials shown in FIGS. 1 to 4 and the fired products shown in FIGS. 5 to 8, when observed by an electron microscope, firing was performed without adding a flux during firing. As a result, the aluminate-based phosphor having afterglow characteristics can be obtained while the α-alumina powder is fired without melting, and the raw material α-alumina powder does not melt and maintains the particle size as it is.

However, comparing Tables 1 and 3, the measured value of the average particle diameter of the obtained aluminate-based phosphor having the afterglow characteristic based on the laser scattering method is substantially the same as that of the crushed surface. AA-07, AA-3,
In the case of using AA-5 and RA-40 having a crushed surface, the average particle diameter of the α-alumina powder raw material before firing is 0.66 μm to 4.7 μm, and the average particle diameter in a wide range is used. However, the average particle diameter of the obtained aluminate-based phosphor having afterglow characteristics after firing is 6.4 μm to 1 μm.
0.9 μm, which is about 13 times to about 2.3 times the average particle diameter of the raw material α-alumina powder.

This is based on the raw materials shown in FIGS.
As can be seen from comparison with the calcined product up to FIG. 8, if the primary particle diameter of the raw material α-alumina powder is small, adjacent particles of the α-alumina powder are fused with each other and the primary particle diameter is about several μm. Droplets are formed, and the particles are fired in a state where the fused particles having a size of about several μm are adhered by a weak force. In addition, when the particle diameter of the raw material α-alumina powder is large, the particles of the raw material α-alumina powder maintain the particle diameter as they are without melting, but the particles adjacent to each other are adhered with a weak force. Fired. Therefore, by crushing with an automatic mortar for about 20 minutes, small particles having almost no coarse particles and fine powder and having an average particle diameter of about 10 μm can be obtained.

On the other hand, in the case of a commercially available aluminate-based phosphor having afterglow characteristics, the 50% average particle diameter (D50) is set to a particle diameter equivalent to that of AA-07, AA-3, or AA-5. For this purpose, crushing must be performed sufficiently, and the labor involved in this crushing is enormous. In addition, it is apparent that the afterglow intensity is equal to or less than that of the particles having the same particle diameter, the particle diameters are irregular, and classification is required.

In the case of RA-40, the afterglow intensity was lower than that of a commercially available aluminate-based phosphor having afterglow characteristics. This is because the primary particle diameter of the raw material α-alumina is 0.46
μm is much smaller than other particle diameters, and the average particle diameter of the obtained phosphor is much smaller at 6.4 μm. Therefore, a commercially available aluminate-based phosphor having afterglow characteristics was compared. It should be compared with an average particle diameter of about RA-40, but it is practically impossible to grind a commercially available aluminate-based phosphor having afterglow characteristics to about 6.4 μm.

As can be seen from the above results, the aluminate-based phosphor having the afterglow characteristic according to the present invention exhibits a high afterglow intensity despite the small average particle diameter, and the aluminate phosphor having extremely excellent afterglow characteristic A salt-based phosphor can be obtained.

In this embodiment, (Sr _0.988 , Eu
_0.010, Dy _0.002) although an example of O · Al ₂ O ₃ phosphor, the general formula; aMO · Al ₂ O ₃ (where, M is strontium (Sr), calcium (Ca), barium (B
a) a compound comprising at least one or more metal elements selected from the group consisting of a), a is a composite oxide substrate represented by 0.5 to 1.1), and europium (E) as an activator;
u) is 0.00% by mol% based on the metal element represented by M.
2% or more and 20% or less are added, and as a co-activator,
Cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), terbium (T
b), dysprosium (Dy), holmium (Ho),
Erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (S
c) an aluminate-based phosphor having afterglow characteristics, wherein at least one or more elements in the group consisting of M are added in an amount of 0.002% or more and 20% or less with respect to a metal element represented by M;
And a general formula: (Sr, Eu, Pb, Dy) O.y (A
l, Bi) Aluminate-based phosphor having afterglow characteristics based on Eu ²⁺ -activated strontium-aluminate-based phosphor represented by ₂ O ₃ (where 0.83 ≦ y ≦ 1.67) Also, by firing without using a flux, an aluminate-based phosphor having fine afterglow characteristics derived from the raw material alumina powder can be obtained.

[0051]

According to the present invention, it is possible to obtain an aluminate-based phosphor having excellent afterglow characteristics, which is easy to pulverize and has a small amount of fine particles, and which has high afterglow characteristics with a high product yield. The aluminate-based phosphor having this afterglow characteristic is industrially extremely useful.

[Brief description of the drawings]

FIG. 1 is a drawing substitute photograph of the particle shape of a raw material α-alumina (AA-07) powder with a scanning electron microscope. FIG. 1A is a drawing having a magnification of 2000 times, and FIG. 1B is a drawing having a magnification of 5000 times. Things.

FIG. 2 is a drawing substitute photograph of the particle shape of a raw material α-alumina (AA-3) powder with a scanning electron microscope, wherein FIG. Things.

FIG. 3 is a drawing substitute photograph of the particle shape of a raw material α-alumina (AA-5) powder with a scanning electron microscope. FIG. 3A is a drawing having a magnification of 2000 times, and FIG. 3B is a drawing having a magnification of 5000 times. Things.

FIG. 4 is a drawing substitute photograph of the particle shape of a raw material α-alumina (RA-40) powder with a scanning electron microscope. FIG. Things.

FIG. 5 is a drawing substitute photograph of the particle shape of the aluminate-based phosphor (AA07-127R) having afterglow characteristics obtained by the present invention, which is taken by a scanning electron microscope.
2,000 times, and the b figure shows a 5000 times magnification.

FIG. 6 is a drawing substitute photograph of the particle shape of the aluminate-based phosphor (AA30-129R) having afterglow characteristics obtained by the present invention, which is obtained by a scanning electron microscope.
2,000 times, and the b figure shows a 5000 times magnification.

FIG. 7 is a drawing substitute photograph of the particle shape of the aluminate-based phosphor (AA50-130R) having afterglow characteristics obtained by the present invention, which is taken by a scanning electron microscope.
2,000 times, and the b figure shows a 5000 times magnification.

FIG. 8 is a drawing substitute photograph of the particle shape of the aluminate-based phosphor (RA-124R) having afterglow characteristics obtained in the present invention, which is obtained by a scanning electron microscope.
The figure at 0 times and the figure at b have a magnification of 5000 times.

FIG. 9 shows a comparative phosphor CP-05 6C30 having afterglow characteristics.
3 is a drawing-substitute photograph of the particle shape with a scanning electron microscope before crushing, and FIG. A is a photograph having a magnification of 2000 times and FIG. B is a photograph having a magnification of 5000 times.

FIG. 10 is a drawing substitute photograph of a particle shape of a comparative example of CP-05 6C30SS with a scanning electron microscope.
The figure at 00 times and the figure at b have a magnification of 5000 times.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-59617 (JP, A) JP-A-10-53762 (JP, A) JP-A-6-191833 (JP, A) JP-A-6-191833 191835 (JP, A) JP-A-6-191836 (JP, A) JP-A-7-187663 (JP, A) JP-A-10-251637 (JP, A) JP-A-9-316444 (JP, A) WO 96/32457 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09K 11/64 CPM C09K 11/08

Claims (3)

(57) [Claims] 1. A general formula: aMO.Al ₂ O ₃ (M is strontium (Sr), calcium (Ca),
At least one selected from the group consisting of barium (Ba)
A compound comprising at least one metal element, a is from 0.5 to 1.
In the composite oxide substrate shown in 1), mol% of europium (Eu) as an activator with respect to a metal element represented by M is added.
And at least 0.002% to 20%, and lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), gadolinium (Gd) terbium as a co-activator. (Tb),
Dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Y
b), at least one element of the group consisting of lutetium (Lu), manganese (Mn), tin (Sn), bismuth (Bi), and scandium (Sc) is 0.002 in mol% with respect to the metal element represented by M. % To 20% or less in the synthesis of an aluminate-based phosphor having afterglow characteristics , the primary alumina having a primary particle diameter of 0.3 μm or more is 3 μm or more.
Α-alumina powder having substantially no crushed surface of 0 μm or less
Using powder, at the time of firing after mixing the raw material alumina powder, the selected metal element, activator and coactivator, firing at a predetermined temperature without adding a flux A method for producing an aluminate-based phosphor having afterglow characteristics. 2. Eu ^{2+ represented by the} general formula: (Sr, Eu, Pb, Dy) O.y (Al, Bi) ₂ O ₃ (where 0.83 ≦ y ≦ 1.67)
In synthesizing an aluminate-based phosphor having an afterglow characteristic based on an activated strontium-aluminate-based phosphor , a primary alumina having a primary particle diameter of 0.3 μm or more is used as a raw material alumina.
Α-alumina powder having substantially no crushed surface of 0 μm or less
Using powder, at the time of firing after mixing the raw material alumina powder, the selected metal element, activator and coactivator, firing at a predetermined temperature without adding a flux A method for producing an aluminate-based phosphor having afterglow characteristics. 3. In synthesizing an aluminate-based phosphor having the afterglow characteristic represented by the general formula: (Sr, Eu, Dy) O.Al ₂ O ₃ , the primary particle diameter is set to 0 as a raw material alumina. . 3μm or more and 3
Using α-alumina powder having substantially no crushed surface of 0 μm or less, firing after mixing the raw material alumina powder, the selected raw material metal element of the general formula, an activator and a co-activator; A method for producing an aluminate-based phosphor having afterglow characteristics, wherein the aluminate-based phosphor is fired at a predetermined temperature without adding a flux.