JPH09143464A - High-luminance long-afterglow phosphorescent material and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a luminous material having long afterglow and high brightness and to produce the luminous material by simple production facilities.

SOLUTION: This luminous material is a sintered compact of the formula MO.(n-x) [aAl₂O₃(α)+(1-a)Al₂O₃(γ)].xBO₂O₃:R [in the formula, M is an alkaline earth metal; R is a rare earth element; (a) is in a range of 0.5<a≤0.99; (x) is in a range of 0.001≤x≤0.35; (n) is in a range of 1≤n≤8]. Especially preferably M is strontium and R is europium. Especially preferably, (a) is in a range of 0.8≤a≤0.9 and (x) is in a range of 0.05≤x≤0.1. The luminous material is obtained by mainly carrying out (1) a baking process, (2) a grinding process and (3) a process for reducing the ground material. The processes 1 and 3 can be simultaneously carried out. In the reducing process 3, carbon powder can be used as the reducing agent.

COPYRIGHT: (C)1997,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-brightness long-afterglow phosphorescent material and a method for producing the same, and more specifically to 200n.
The present invention relates to a phosphorescent material having a long afterglow property and exhibiting high brightness when excited by ultraviolet rays of m to 450 nm, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, luminous paints used for timepiece dials, safety signboards, and the like, use a phosphorescent material (ZnS: Cu) obtained by activating a sulfide, for example, zinc sulfide, with copper. It is kneaded in. This sulfide is excited by absorbing energy such as ultraviolet rays having a wavelength in a certain range and emits light, and therefore has the same mechanism as the light emitting mechanism of the phosphorescent material. However, these sulfides have few problems in practical use because they have almost no afterglow properties or are chemically unstable and thus have poor light resistance. When such a sulfide is used, for example, in a luminous timepiece, the afterglow time that can be recognized by the human eye is about 20 to 30 minutes, which is not practical, and the luminescence function is lost by photolysis with ultraviolet rays. Therefore, it was insufficient for outdoor use.

Conventionally, in order to extend the afterglow time of the sulfide as described above, a means for adding a radioactive substance, for example, promethium (Pm), to the sulfide to impart self-luminous properties has been used. If radioactive materials are used, measures must be taken to take into account the harmful effects on the human body, strict management is required during use, and waste materials such as equipment used for manufacturing and washing wastewater At present, it has not been put into practical use because of the high cost of disposal.

On the other hand, as a light emitting body different from these sulfide-based phosphorescent materials, there has been proposed a fluorescent material in which a rare earth element europium is added to an alkaline earth metal aluminate. For example, US Pat. No. 3,294,699 discloses strontium aluminate (SrAl ₂ O ₄ : Eu) using divalent europium as an activator. The amount of the divalent europium added is 2 to 8 mol% in mol% with respect to the strontium aluminate. The emission peak wavelength when this fluorescent material is excited by ultraviolet light is 520 nm. However, such a fluorescent material has almost no afterglow and is distinguished from the above-described phosphorescent material or phosphorescent material.

Similarly, another example is a fluorescent material obtained by adding an alkaline earth metal to strontium aluminate. For example, British Patent fluorescent material was activated by bivalent europium to the 1,190,520 Pat, Ba _x Sr _y
Ca _z Eu _p Al ₁₂ with _{O 19 (x + y + z} + p = 1, x,
One or two of y and z may be 0, and 0.1 ≧ p ≧ 0.
It is 001. ) Is disclosed. The peak wavelength at which the fluorescent material emits light when excited by ultraviolet light is 380 n.
m to 440 nm. Each of these fluorescent materials emits light when excited by ultraviolet rays or electron beams, and is mainly used for cathode ray tubes.

As the boron-containing SrAl ₂ O ₄ -based light emitting material, for example, European Patent Application Publication No. 009 is used.
Japanese Patent No. 4132 discloses a SrAl ₂ O ₄ structure to which boron oxide is added as a fluxing agent, and the addition amount is from 0.002 mol. It is limited to 1 mol and has poor afterglow.

Besides this, for example, Japanese Patent Laid-Open No. 7-11250.
In addition, boron oxide is added as a fluxing agent in the production of the phosphorescent material made of SrAl ₂ O ₄ crystal, but the addition amount is limited to 1 to 10%. The reason for limiting the amount of boron oxide added is that if it is 1% by weight or less, there is no flux effect, and if it exceeds 10% by weight, the fired product solidifies,
This is because the subsequent crushing and classification work becomes difficult.

Recently, a luminescent material having a long afterglow time has been developed by exciting it with desired light energy. For example, Chinese Patent Application Publication No. CN1053807A discloses an invention relating to a long persistence luminescent material. This long afterglow luminescent material has the general formula m (Sr _1-x Eu _x ) O.
nAl ₂ O ₃ .yB ₂ O ₃ [However, 1 ≦ m ≦ 5, 1 ≦ n
≦ 8, 0.001 ≦ y ≦ 0.35]. This long afterglow light-emitting material is made of a divalent oxide of aluminum, strontium and europium or a salt capable of producing these oxides after heating as a raw material at 1200 ° C.
After firing at ˜1600 ° C., it is manufactured by a process of reducing at 1000 ° C. to 1400 ° C. in a reducing atmosphere of nitrogen and hydrogen.

[0009]

However, this long afterglow luminescent material has a problem that the practical brightness is not sufficient because the initial brightness is low although the afterglow time is actually 4 to 5 hours. . Therefore, the inventors of the present invention, in order to solve such problems, improved a light emitting material in which an aluminate of an alkaline earth metal of the above general formula and a rare earth metal as an activator are combined, As a result of various researches to produce a crystalline body made of a compound, it has higher brightness and longer life than a conventional luminescent material in which a sulfide compound or an alkaline earth metal aluminate and a rare earth metal as an activator are combined. We have succeeded in developing a luminous material having a luminous property and a method for producing the same, and have accomplished the present invention. That is, the first problem to be solved by the present invention is to provide a phosphorescent material having long afterglow and high brightness. A second problem to be solved by the present invention is to provide a method for manufacturing a phosphorescent material having a long afterglow and a high brightness, which can be safely manufactured by a simple manufacturing facility.

[0010]

Means for solving the above problems of the present invention are achieved by the following respective inventions. (1) General formula MO · (n−x) [aAl ₂ O ₃ (α)
+ (1-a) Al ₂ O ₃ (γ)] · xB ₂ O ₃ : R [wherein M represents an alkaline earth metal, R represents a rare earth element, and a is 0.5 <a ≦ 0.99 and x is 0.001
≦ x ≦ 0.35, and n is 1 ≦ n ≦ 8. ] A high-brightness long-afterglow phosphorescent material comprising a fired body represented by: (2) M is strontium and R is europium. The high-brightness long-afterglow phosphorescent material as described in the above item 1. (3) A part of strontium represented by M is Mg, C
The second aspect, which can be substituted with at least one kind of alkaline earth metal selected from the group of a and Ba.
High-luminance long-afterglow phosphorescent material according to the item. (4) A part of europium represented by R is La or C
e, Pr, Nd, Sm, Gd, Tb, Dy, Ho, E
The high-brightness long-afterglow phosphorescent material according to the above item 2 or 3, which can be substituted with at least one kind of metal selected from the group consisting of r, Tm, Yb, Lu, Mn, and Bi. (5) The addition amount of R in the general formula is 0.001% to 10% in mol% with respect to M.
Item 5. A high-brightness long-afterglow phosphorescent material according to any one of items 4 to 4. (6) The range of a is 0.8 ≦ a ≦ 0.9, and x is 0.
05 ≦ x ≦ 0.1, The high-intensity long-afterglow phosphorescent material according to any one of the first to fifth items. (7) In the method for producing a high-luminance long-afterglow phosphorescent material according to the above-mentioned item 1, a high-luminance long-afterglow phosphorescent material comprising the following steps (a) to (g): Production method. (A) a step of pulverizing and then mixing all raw materials consisting of α-alumina, γ-alumina, a boron compound, an alkaline earth metal compound and a rare earth compound (b) the obtained mixture at a temperature of 800 ° C to 1400 ° C Step of firing for ~ 5 hours (c) Step of cooling and then grinding the obtained fired material (d) Step of reducing the ground material at a temperature of 800 ° C-1400 ° C for 2-5 hours (E) Step of cooling the fired body (f) Step of pulverizing the cooled fired body (g) Step of classifying the pulverized powder (8) The steps (b) and (d) are performed simultaneously Item 8. A method for producing a high-luminance long-afterglow phosphorescent material according to Item 7. (9) In the reducing step of (d), carbon powder is used as a reducing agent, and the above-mentioned item 7 or 8 is provided.
Item 3. A method for producing a high-luminance long-afterglow phosphorescent material according to the item. (10) The step (a) comprises (a) a step of thoroughly mixing α-alumina and γ-alumina, (b) and then the mixture obtained in (a), a boron compound, an alkaline earth metal compound and a rare earth compound. The method for producing a high-brightness long-afterglow phosphorescent material according to any one of items 7 to 9, which is a step of pulverizing and mixing all raw materials.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. A phosphorescent material is a material that is excited by sunlight or a fluorescent lamp, particularly ultraviolet rays to absorb its energy, and converts the absorbed energy into visible light. Thus, it is a material that continues to emit light for a long time while gradually emitting light even after the excitation is stopped. The present invention relates to such a phosphorescent material, and the high-brightness long-afterglow phosphorescent material of the present invention has the general formula MO · (n−x) [aAl ₂ O ₃
(Α) + (1-a) Al ₂ O ₃ (γ)] · xB ₂ O ₃ :
R [in the formula, M represents an alkaline earth metal, R represents a rare earth element, a is 0.5 ≦ a ≦ 0.99, and x is 0.
001 ≦ x ≦ 0.35, and n is 1 ≦ n ≦ 8. ] It is characterized by comprising a calcined body, M is strontium, a part of the metal represented by M can be replaced by calcium, barium, magnesium, and a part of the europium represented by R is La, Ce, Pr, Nd, S
m, Gd, Tb, Dy, Ho, Er, Tm, Yb, L
It can be replaced with u, Mn, or Bi. The main component of this fired body is presumed to be a monoclinic crystal body. These high-brightness long afterglow phosphorescent materials have a high emission brightness,
It has a long afterglow and an emission peak wavelength of 520.
It develops a wide range of colors in the range of nm or less. Further, the number tends to increase as the number of n increases.

In the present invention, a part of strontium represented by M can be replaced with calcium up to 25% by mol%. If calcium is added in an amount of more than 25% by mol, a crystalline structure cannot be obtained. Similarly, the addition amount of barium is 10 mol% or less of strontium, and the addition amount of magnesium is 30 mol% or less. Furthermore, by adding these alkaline earth metals, phosphorescent materials having different emission peak wavelengths can be produced. For example, the emission peak wavelength when barium is added to a part of strontium tends to be shorter than that when only strontium is added, becomes shorter when magnesium is added, and becomes the shortest when calcium is added. . The above alkaline earth metals may be used alone or in combination of two or more. When two or more kinds are added, the total amount of MO added is represented by the general formula MO · (n−x) [aAl ₂ O
₃ (α) + (1-a) Al ₂ O ₃ (γ)] xB ₂ O ₃
A ratio of 1: 1 is preferable.

A representative fired body of the high brightness long afterglow phosphorescent material of the present invention is SrO. (Nx) [aAl ₂ O ₃ (α) +
(1-a) Al ₂ O ₃ (γ)] · xB ₂ O ₃ : Eu, which has the characteristics of long afterglow and high brightness due to the fired product. Specifically, it is an oxide of strontium. Manufactured by mixing and firing aluminum oxide and boron oxide or boron compound and europium oxide as an activator, and the obtained fired body is presumed to have a monoclinic system crystal body. To be done. The amount of α-type alumina (α-Al ₂ O ₃ ) in this fired body was 5% of the total amount of alumina.
0% to 99%, γ-type alumina (γ-Al ₂ O ₃ ).
Is 1% to 50% of the total amount of alumina. In this fired body, the ratio of α-type alumina to γ-type alumina was a
Is 0.8 to 0.9, the brightness and long afterglow are good.

According to the present invention, strontium oxide, α type
Alumina and γ-type alumina, boron oxide or boron compound
SrO. (Nx) [aAl by firing at high temperature
_TwoO _Three(Α) + (1-a) Al_TwoO_Three(Γ)] xB_Two
O_ThreeTo produce a crystal body represented by. This crystal is monoclinic
It is a crystalline system and has an activator and an addition activator.
Has not only long afterglow performance but also high brightness
It is something.

When M is strontium, a part of this strontium may be replaced with at least one of Mg, Ca and Ba, and the ratio of MO to the total amount of Al ₂ O ₃ and B ₂ O ₃ is 0. .9 to 1.1 is preferable.
Here, "a part of strontium" refers to the ratio of the total amount of strontium in the crystal body, and is therefore the ratio of Mg, Ca, or Ba to the total amount of strontium in the crystal body.

With respect to the amount of boron in the present invention, when x is less than 0.001, it has no influence on the expression of the long afterglow light storage performance of the crystal. When x is more than 0.35, the amount of boron is not preferable because the long afterglow property is decreased because the amount of boron oxide-based products is increased in the fired body. Usually, x is preferably 0.05 to 0.1.

In the prior art, for example, European Patent Application Publication No. 0094132 discloses a SrAl ₂ O ₄ structure to which boron oxide is added as a fluxing agent, but the addition amount is 0.002 mol. From. Limited to 1 mole. Further, for example, Japanese Patent Laid-Open No. 7-1
In 1250, boron oxide was added as a fluxing agent when the SrAl ₂ O ₄ crystal was produced.
It is limited to 1 to 10% by weight. The reason for limiting the amount of boron oxide to be added is that if it is 1% by weight or less, no flux effect is obtained, and if it exceeds 10% by weight, the fired product is solidified, and subsequent pulverization and classification work becomes difficult. On the other hand, the high-brightness long-afterglow phosphorescent material of the present invention contains boron oxide of less than 0.1%.
By adding 001 to 0.35 mol, a crystal assumed to be a monoclinic system was obtained, and a conventional SrAl ₂ O ₄ :
It is possible to provide a long afterglow and a high brightness different from those of a material having no afterglow such as Eu. The high-brightness long-afterglow phosphorescent material of the present invention is very firm and has a Mohs hardness of 6.0 to 7.

As a raw material for the high-brightness long-afterglow phosphorescent material of the present invention, an oxide of strontium, calcium, barium or magnesium, or a salt capable of forming these oxides by heating can be used. In the present invention, europium is used as the activator, and as the raw material thereof, an oxide of europium or a salt capable of producing these oxides by heating can be used. Further, in the present invention, a rare earth element other than europium is used as an additional activator, whereby the brightness can be improved. Therefore, the brightness can be further improved by combining the activator and the additional activator. As a raw material of the additional activator, an oxide of the additional activator or a salt capable of generating these oxides by heating can be used.

The high brightness long afterglow phosphorescent material of the present invention is MO.
(Nx) [aAl ₂ O ₃ (α) + (1-a) Al ₂ O
₃ (γ)] · xB ₂ O ₃ : R structure, in which R is a divalent rare earth element europium, which acts as an activator, has practical afterglow and brightness, but further has MO. (N -X) [a
Al ₂ O ₃ (α) + (1-a) Al ₂ O ₃ (γ)] x
In order to improve the brightness of the B ₂ O ₃ structure, in addition to europium, another rare earth element as an additional activator, for example,
La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, H
Better brightness can be obtained by using one or more of o, Er, Tm, Yb, and Lu. Besides, Mn or Bi can be used as an additional activator.
It is presumed that this structure is basically a monoclinic crystal. The amount of the activator and the addition activator used is 0.001 to 10% in mol% of the amount of M used in the general formula of the present invention.
When the use amount of the activator and the addition activator is 0.001 or less in mol%, the excitation effect cannot be promoted. Further, when the amount of the activator and the addition activator used exceeds 10% in terms of mol%, rapid quenching (quenching out) may occur, which is not preferable.

The high luminance long afterglow phosphorescent material of the present invention is manufactured by the following manufacturing method. (A) a step of pulverizing and then mixing all raw materials consisting of α-alumina, γ-alumina, a boron compound, an alkaline earth metal compound and a rare earth compound (b) the obtained mixture at a temperature of 800 ° C to 1400 ° C Step of firing for ~ 5 hours (c) Step of cooling the obtained fired product and then pulverizing (d) Then, reducing the pulverized material at a temperature of 800 ° C-1400 ° C for 2-5 hours (E) Step of cooling fired body (f) Step of pulverizing cooled fired body (g) Step of classifying pulverized powder

In the above, the step (a) is (a) the step of thoroughly mixing α-alumina and γ-alumina, and (b)
Then, when the mixture obtained in (a), the boron compound, the alkaline earth metal compound, and the rare earth compound are all pulverized and then mixed, in the case of a step of mixing, α-alumina and γ-alumina may be sufficiently mixed. Not only can it be done, but there is an advantage that one crushing step can be omitted.
The step (b) can be carried out in a normal atmosphere, for example, air, and the step (d) can be carried out under a reducing atmosphere, for example, while introducing a mixed gas of N ₂ and H ₂ or By embedding the fired body or the mixture to be fired in the carbon powder, a reducing atmosphere is created without contacting the fired body or the mixture to be fired with oxygen in the air.
Further, the case where the step (b) and the step (d) are simultaneously carried out is a method of embedding the latter sintered body or a mixture to be sintered in carbon powder and firing in this state in an oxidizing atmosphere. The latter method of directly reducing with carbon powder is a safe and economical method and is particularly preferable in the present invention.

Since the high-brightness long-afterglow phosphorescent material of the present invention contains a large amount of boron, it does not require a high firing temperature, and therefore the production cost can be reduced. The high-luminance long-afterglow phosphorescent material of the present invention can be mixed with ink or resin to produce luminescent ink or luminescent resin. The brightness of the phosphorescent material of the present invention is so high that it can be used for display at night. For example, when it is used for road displays, advertisements, stationery, toys, sports equipment, etc., it absorbs light, emits the absorbed energy in the form of light in the dark, and continuously emits light for 10 hours or more. Further, if a liquid crystal backlight is used as an auxiliary light source, it is possible to save the power supply and reduce the weight of the device.

[0023]

EXAMPLES The present invention will be further described below based on examples, but the examples are for explaining the present invention and the present invention is not limited thereto.

Example 1 14.468 g of SrCO _{3 and} 4.72 of α-Al ₂ O ₃
g, γ-Al ₂ O ₃ 4.36 g, H ₃ BO ₃ 1.36 g
Prepare As a raw material for the activator and the additional activator, Eu ₂
0.13 g of O _{3 and} 0.187 g of Dy ₂ O ₃ are prepared. The above raw materials are crushed, mixed well, and then put in a crucible. The crucible containing the above mixture is placed in an electric furnace and baked in a N ₂ + H ₂ reducing atmosphere at a temperature of around 1100 ° C. for 4 hours. Then, after cooling to 200 ° C., it is taken out from the electric furnace. Crush with a ball mill at room temperature,
Further, classification was performed with a 200-mesh sieve to obtain the phosphorescent material [1] of the present invention. The obtained crystal is MO. (Nx)
[AAl ₂ O ₃ (α) + (1-a) Al ₂ O ₃ (γ)]
· XB ₂ O _3: In structure represented by R, wherein, M is strontium, X = 0.11, n = 1 , a = 0.52
It is.

Example 2 SrCO_Three14.468 g, α-Al_TwoO_Three9.931
g, γ-Al_TwoO_Three0.095g, H_ThreeBO_Three0.86
Prepare 6 g. As a raw material for the activator and the additional activator, E
u_TwoO_Three0.176g, Dy_TwoO_Three0.187g it
Prepare each one. The above raw materials were crushed and mixed
Then put in a crucible. Place the crucible containing the above mixture in carbon
Put in an electric furnace in a reducing atmosphere surrounded by powder,
Hold at a temperature around 0 ° C. for 4 hours. Cool to 200 ° C
You. Then, remove from the electric furnace. When it reaches room temperature,
Crushed with a mill and then classified with a 200 mesh screen.
Thus, the phosphorescent material [2] of the present invention was obtained. Manufactured crystals
Is MO · (n−x) [aAl _TwoO_Three(Α) + (1-
a) Al_TwoO_Three(Γ)] xB_TwoO_Three: Structure represented by R
In the formula, M is strontium and X = 0.0.
7, n = 1 and a = 0.99.

Example 3 SrCO_Three144.68 g, α-Al_TwoO_Three80.63
g, γ-Al_TwoO_Three14.23g, H_ThreeBO_Three8.66
Prepare g. As a raw material for the activator and the additional activator, Eu
_TwoO_Three1.76g, Dy_TwoO_Three1.87g for each
I mean. After crushing and mixing the above raw materials,
Put in a pot. Place the crucible containing the above mixture in an electric furnace.
And fired at 1200 ° C. for 4 hours. Cool this,
After crushing, N for 3 hours at 1000 ° C_Two+ H_TwoAtmosphere
Give back with care. The following steps are performed in the same manner as in Example 1.
The phosphorescent material [3] of the present invention was obtained. The produced crystal is M
O · (n−x) [aAl_TwoO_Three(Α) + (1-a) Al
_TwoO_Three(Γ)] xB_TwoO _Three: A structure represented by R,
In the formula, M is strontium, X = 0.07, n = 1,
a = 0.85.

Example 4 14.468 g of SrCO _{3 and} 6.39 of α-Al ₂ O ₃
g, γ-Al ₂ O ₃ 3.76 g, H ₃ BO ₃ 0.061
Prepare 8 g. As a raw material for the activator and the additional activator, E
u ₂ O ₃ 0.176g, prepared respectively Dy ₂ O ₃ 0.187g. The above raw materials were manufactured by the manufacturing method of Example 1 to obtain the phosphorescent material [4] of the present invention. The obtained crystal was MO. (N−x) [aAl ₂ O ₃ (α) + (1-
a) Al ₂ O ₃ (γ)] · xB ₂ O ₃ : R is a structure represented by the formula, where M is strontium and X = 0.00.
5, n = 1 and a = 0.63.

Example 5 14.468 g of SrCO _{3 and} 6.03 of α-Al ₂ O ₃
g, γ-Al ₂ O ₃ 0.59 g, H ₃ BO ₃ 4.832.
Prepare g. As a raw material for the activator and the additional activator, Eu
0.176 g of ₂ O _{3 and} 0.187 g of Dy ₂ O ₃ are prepared. The above raw materials are crushed, mixed, and put in a crucible. The crucible containing the above mixture is placed in an electric furnace and fired at a temperature of 800 ° C. for 5 hours. After cooling and crushing, the temperature was raised to 1000 ° C., CO gas was introduced, and the mixture was held in a reducing atmosphere for 2 hours for reduction. Then
Cool to 200 ° C. Then, remove from the electric furnace.
When it reached room temperature, it was crushed with a ball mill and classified with a 200-mesh sieve to obtain the phosphorescent material [5] of the present invention. The obtained crystal is MO. (N−x) [aAl ₂ O ₃ (α)
+ (1-a) Al ₂ O ₃ (γ)] × B ₂ O ₃ : R is a structure represented by the formula, where M is strontium and X =
0.35, n = 1, and a = 0.91.

Example 6 14.468 g of SrCO _{3 and} 13.71 of α-Al ₂ O ₃
g, γ-Al ₂ O ₃ 5.86 g, H ₃ BO ₃ 0.99 g
Prepare As a raw material for the activator and the additional activator, Eu ₂
0.13 g of O _{3 and} 0.187 g of Dy ₂ O ₃ are prepared. After the above raw materials are crushed and mixed, they are put into a crucible. Put the crucible containing the above mixture in an electric furnace,
Hold at a temperature of 1300 ° C. for 5 hours in a reducing atmosphere of N ₂ + H ₂ . Cool to 200 ° C. Then, remove from the electric furnace. It was crushed with a ball mill at room temperature and classified with a 200-mesh sieve to obtain the phosphorescent material [6] of the present invention. The obtained crystal was MO. (N−x) [aAl ₂ O ₃ (α) +
(1-a) Al ₂ O ₃ (γ)] · xB ₂ O ₃ : R is a structure, in which M is strontium and X = 0.
08, n = 2, and a = 0.70.

Example 7 SrCO ₃ 123 g, CaCO ₃ 14.7 g, α-Al
₂ O ₃ 57.38 g, γ-Al ₂ O ₃ 19.13 g, H
₃ BO ₃ 30.91 g is prepared. As raw materials for the activator and the additional activator, 1.76 g of Eu ₂ O ₃ and Dy ₂ O ₃ 1.
Prepare 87 g of each. The above raw materials are crushed, thoroughly mixed, and then put in a crucible. The crucible containing the above mixture is placed in an electric furnace and fired at a temperature of 1300 ° C. for 2 hours in a reducing atmosphere obtained by embedding carbon powder in the crucible and simultaneously reduced. Then, after cooling to 200 ° C., it is taken out from the electric furnace. When it reached room temperature, it was crushed with a ball mill, and the crushed product was classified with a 200-mesh sieve to obtain the phosphorescent material [7] of the present invention. The obtained crystal is MO. (N
-X) [aAl ₂ O ₃ (α) + (1-a) Al ₂ O
₃ (γ)] · xB ₂ O ₃ : R is a structure, in which M is 85% strontium and 15% calcium.
, Α-Al ₂ O ₃ 75%, γ-Al ₂ O ₃ 25%, X
= 0.25, n = 1, and a = 0.75.

Example 8 SrCO_Three130.2g, BaCO_Three19.34 g, α
-Al_TwoO_Three172.63 g, γ-Al_TwoO_Three12.9
9g, H_ThreeBO_ThreePrepare 22.25 g. With activator
Eu as a raw material of the activating agent_TwoO_Three1.76g, Dy_Two
O_ThreePrepare 1.87 g each. Crush the above raw materials
Then, after mixing, put in a crucible. Put the above mixture
Put the crucible in the electric furnace and_Two+ H_Two1 in a reducing atmosphere
Hold at a temperature of 300 ° C. for 4 hours. Then up to 200 ℃
After cooling, take out from the electric furnace. When it reaches room temperature,
Crushed with a mill and classified with a 200 mesh screen
The phosphorescent material [8] of the invention was obtained. The produced crystal is MO
-(N-x) [aAl_TwoO _Three(Α) + (1-a) Al_Two
O_Three(Γ)] xB_TwoO_Three: R is a structure represented by the formula
Medium, M is Sr90% and Ba10%, α-Al_TwoO_Three9
3%, γ-Al_TwoO _Three7%, X = 0.18, n = 2, a
= 0.93.

The phosphorescent material (1) of the present invention produced as described above
The characteristics of (8) are shown in Table 1. Table 2 shows the results of a comparison test of the phosphorescent materials (1) to (8) of the present invention with respect to the decrease in luminance with time, with the zinc sulfide phosphorescent material “ZnS: Cu”. Test conditions: (1) to (8) and (Zn
Each sample of S: Cu) was taken in a dark room in an amount of 0.2 g, placed in an aluminum container having a diameter of 10 mm and a depth of 5 mm, at a temperature of 24 ° C. and a humidity of 25% RH, and at a distance of 20 cm vertically below a 15 W fluorescent lamp for 15 minutes. Irradiated. Then, each brightness is measured with a Topcon BM-5 brightness meter over time.

[0033]

[Table 1]

As is clear from Table 1, the emission peak wavelength of the high-brightness long-afterglow phosphorescent material of the present invention varies depending on the number of n, and as the number increases, shift from the long-wavelength side to the short-wavelength side. However, it can be seen that the color changes from green to blue, which is close to indigo.

[0035]

[Table 2]

As is clear from Table 2, the results of the test conducted under the same conditions show that the initial luminance of the high-brightness long-afterglow phosphorescent material of the present invention is compared with the initial luminance of the zinc sulfide phosphorescent material of the comparative example.
It turns out that it has 10 times or more. Regarding the afterglow time, the afterglow time of the zinc sulfide phosphorescent material of Comparative Example is about 1 hour, whereas the afterglow time of the high-brightness long-afterglow phosphorescent material of the present invention is about 50 hours. You can see that it is over.

Example 9 107.39 g of SrCO _3, 20.44 g of MgCO _{3
α-Al 2 O 3 57.38g,} γ-Al 2 O 3 19.1
3g, to prepare the H ₃ BO ₃ 30.91g. As a raw material for the activator and the additional activator, Eu ₂ O ₃ 2.64 g, Dy ₂
Prepare 2.80 g of O ₃ respectively. The above raw materials are crushed, thoroughly mixed, and then put in a crucible. The crucible containing the above mixture is placed in an electric furnace and fired at a temperature of 1300 ° C. for 2 hours in a reducing atmosphere obtained by embedding carbon powder in the crucible and simultaneously reduced. Then, after cooling to 200 ° C., it is taken out from the electric furnace. When it reaches room temperature, it is crushed with a ball mill, and the crushed product is classified with a 200-mesh sieve to obtain the phosphorescent material of the invention.

[9] was obtained. The obtained crystal is MO
· (N-x) _{[aAl 2 O 3 (α) +} (1-a) Al 2
O ₃ (γ)] · xB ₂ O ₃ : R is a structure represented by the formula where M is 85% strontium and 15% calcium.
, Α-Al ₂ O ₃ 75%, γ-Al ₂ O ₃ 25%, S
r: Mg = 3: 1, X = 0.05, n = 1, a = 0.7
5 An excellent phosphorescent material was obtained even when magnesium was used as a part of strontium.

Example 10 144.68 g of SrCO ₃ and α-Al ₂ O ₃ 234.1
9 g, γ-Al ₂ O ₃ 51.41 g, H ₃ BO ₃ 24.
Prepare 72 g. As a raw material for activators and additional activators,
1.76 g of Eu ₂ O _{3 and} 1.87 g of Dy ₂ O ₃ are prepared. After the above raw materials are crushed and mixed, they are put into a crucible. The crucible containing the above mixture is placed in an electric furnace and fired at a temperature of 1350 ° C. for 5 hours in a reducing atmosphere in the presence of carbon powder. After cooling to 200 ℃,
Remove from electric furnace. When it reaches room temperature, it is crushed with a ball mill and classified with a 200-mesh sieve to obtain the phosphorescent material of the present invention.

[9] was obtained. The obtained crystal is MO. (Nx)
[AAl ₂ O ₃ (α) + (1-a) Al ₂ O ₃ (γ)]
XB ₂ O ₃ : a structure represented by R, where M is Sr
, Α-Al ₂ O ₃ 82%, γ-Al ₂ O ₃ 18%, X
= 0.20, n = 3, and a = 0.82. This phosphorescent material (10) has an emission peak wavelength of 450 nm and an initial brightness of 4
000 and an afterglow time of 20 hours or longer, an excellent blue color close to indigo was obtained.

Example 11 Instead of the step of crushing and mixing all the raw materials,
First, α-Al_TwoO_Three80.63 g and γ-Al_TwoO_Three
14.23 g was mixed well to obtain a uniform mixture.
Compound and SrCO_Three144.68 g, H_ThreeBO_Three8.6
6 g, Eu as a raw material for the activator and the additional activator,_TwoO
_Three1.76g, Dy_TwoO_Three1.87g each crushed
Then, the same method as in Example 3 is performed except that these are mixed.
Thus, the phosphorescent material [10] of the present invention was obtained. Manufacture
The obtained crystal is MO · (n−x) [aAl _TwoO_Three(Α)
+ (1-a) Al_TwoO_Three(Γ)] xB_TwoO_Three: R table
In the formula, M is strontium and X =
0.07, n = 1, and a = 0.85. This phosphorescent material
Α-Al according to the manufacturing method of [11]_TwoO_ThreeAnd γ-Al_Two
O_ThreeCan be mixed well and the crushing process can be saved
It was economical.

Example 12 Instead of the step of crushing and mixing all the raw materials,
First, α-Al_TwoO_Three9.931 g and γ-Al_TwoO_Three
0.095 g was mixed well to obtain a uniform mixture.
Compound and SrCO_Three14.468g, H_ThreeBO_Three0.8
66 g, Eu as a raw material for the activator and the additional activator,_TwoO_Three
0.176g, Dy_TwoO_Three0.187g each crushed
Then, the same method as in Example 2 was performed except that these were mixed.
As a result, the phosphorescent material [11] of the present invention was obtained. Manufacture
The obtained crystal is MO · (n−x) [aAl_TwoO_Three(Α)
+ (1-a) Al_TwoO_Three(Γ)] xB_TwoO_Three: R table
In the formula, M is strontium and X =
0.07, n = 1, and a = 0.99. This phosphorescent material
Α-Al according to the manufacturing method of [12]_TwoO_ThreeAnd γ-Al _Two
O_ThreeCan be mixed well and the crushing process can be saved
It was economical.

[0041]

The high-luminance long-afterglow phosphorescent material of the present invention is a phosphorescent material represented by the general formula, and has the following excellent effects. Since it has a high initial luminance and a long afterglow property, it is bright and can maintain a light emitting state for a long time, and thus can be used for many purposes. Since the high-brightness long-afterglow phosphorescent material of the present invention contains no radioactive substance, there is no danger of radiation. By the method for producing a long-afterglow high-brightness phosphorescent material of the present invention, a phosphorescent material having a long afterglow property is obtained, and particularly when carbon powder is used as a reducing atmosphere, the process is simplified, It is also efficient, safe and therefore industrially productive.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Liu Baozen, Yungang Haifung Machinery Technology Research Center, Fengtai-ku, Beijing, China (72) Inventor ▲ Kaku ▼ Keilong, Beijing, Fengtai-ku, China Junior high school (72) Inventor Xu Qian No.45 Zhujia Killi, Changxiang store, Fengtai-ku, Beijing, China (72) Inventor Ogura, Atsushi Wakamatsucho, Fuchu, Tokyo 33, Chemtech Co., Ltd. at 8th place (72) Inventor ▲ Kure ▼ 2, 33, Wakamatsucho, Fuchu-shi, Tokyo Keimitech Co., Ltd.

Claims (10)

[Claims] 1. A general formula MO. (N-x) [aAl ₂ O ₃
(Α) + (1-a) Al ₂ O ₃ (γ)] · xB ₂ O ₃ :
R [in the formula, M represents an alkaline earth metal, R represents a rare earth element, a is 0.5 ≦ a ≦ 0.99, and x is 0.
001 ≦ x ≦ 0.35, and n is 1 ≦ n ≦ 8. ] A high-brightness long-afterglow phosphorescent material comprising a fired body represented by: 2. The high-brightness long-afterglow phosphorescent material according to claim 1, wherein M is strontium and R is europium. 3. A part of strontium represented by M is M
The high-brightness long-afterglow phosphorescent material according to claim 2, which can be substituted with at least one kind of alkaline earth metal selected from the group consisting of g, Ca, and Ba. 4. A part of europium represented by R is L
a, Ce, Pr, Nd, Sm, Gd, Tb, Dy, H
The high-brightness long-afterglow phosphorescent material according to claim 2 or 3, which can be substituted with at least one metal selected from the group consisting of o, Er, Tm, Yb, Lu, Mn, and Bi. 5. The high-brightness long-afterglow according to claim 1, wherein the addition amount of R in the general formula is 0.001% to 10% in mol% with respect to M. Material phosphorescent material. 6. The range of a is 0.8 ≦ a ≦ 0.9, and x
Is 0.05≤x≤0.1. 6. The high-brightness long-afterglow phosphorescent material according to claim 1, wherein 7. The method for producing a high-luminance long-afterglow phosphorescent material according to claim 1, comprising the following steps (a) to (g): Manufacturing method. (A) a step of pulverizing and then mixing all raw materials consisting of α-alumina, γ-alumina, a boron compound, an alkaline earth metal compound and a rare earth compound (b) the obtained mixture at a temperature of 800 ° C to 1400 ° C Step of firing for ~ 5 hours (c) Step of cooling the obtained fired product and then pulverizing (d) Then, reducing the pulverized material at a temperature of 800 ° C-1400 ° C for 2-5 hours (E) Step of cooling fired body (f) Step of pulverizing cooled fired body (g) Step of classifying pulverized powder 8. The method for producing a high-luminance long-afterglow phosphorescent material according to claim 7, wherein steps (b) and (d) are performed simultaneously. 9. The method for producing a high brightness long afterglow phosphorescent material according to claim 7, wherein carbon powder is used as a reducing agent in the reducing step (d). 10. The step (a) comprises (a) α-alumina and γ
-Process of mixing alumina well, (b) and then (a)
10. The high brightness length according to claim 7, which is a step of pulverizing and then mixing all the raw materials consisting of the mixture, the boron compound, the alkaline earth metal compound and the rare earth compound obtained in Manufacturing method of afterglow phosphorescent material.