JP3447274B2 - Method for producing aluminate phosphor - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an aluminate phosphor. Specifically, divalent europium (Eu ²⁺ ) or Eu ²⁺ and 2 which can provide a high-luminance fluorescent film with high luminance and less deterioration in luminance over time and high phosphor packing density.
The present invention relates to a method for producing a blue to blue-green light emitting alkaline earth metal aluminate phosphor activated with valent manganese (Mn ²⁺ ).

[0002]

2. Description of the ^Related Art Alkaline earth metal aluminate phosphors activated by Eu ²⁺ or Eu ²⁺ and Mn ²⁺ emit high-luminance blue or blue-green light when excited by ultraviolet rays or vacuum ultraviolet rays, High color rendering fluorescent lamp and plasma display (P
It is widely used as a fluorescent film for a blue to blue-green light emitting component of DP). In order to increase the emission brightness of these fluorescent lamps and PDPs, various studies have been made to further improve the emission brightness of the above aluminate phosphor.

However, conventional Eu 2 ⁺ -activated or Eu ²⁺ and Mn ²⁺ co-activated alkaline earth metal aluminate phosphors have non-uniform particle size, and the particle shape is plate-shaped. Due to the tendency of aggregation, the phosphor film using this had a poor filling rate of the phosphor in the film and the phosphor film was also non-uniform.

Therefore, in order to obtain a uniform phosphor film at a low cost by increasing the phosphor filling rate when the phosphor film is used and reducing the amount of phosphor used per unit weight, the shape of the phosphor is spherical or nearly spherical. It has been proposed to use the Alkaline earth metal aluminate phosphor particles.

As a method for producing the same, a method of melting a phosphor material by plasma and then condensing it into spherical particles (see Japanese Patent Publication No. 7-45655), dropletizing an aqueous solution of the phosphor material, Although a method has been proposed in which these droplets are instantly frozen and then heated (see Japanese Patent Application Laid-Open No. 9-291275), all of them have poor production efficiency and are not suitable for industrial production.

Further, in Japanese Unexamined Patent Publication (Kokai) No. 11-199867, particles having a uniform major axis diameter and an aluminum oxide having an approximately spherical shape and an approximately spherical aspect ratio, an amorphous barium carbonate, an amorphous europium oxide and an amorphous form are disclosed. The raw material mixture consisting of basic magnesium carbonate is baked to give a maximum of 1μ on the particle surface.
Ba _0.9 E, which is roughly spherical as a whole, having irregularities of about m
It is described that a u _0.1 MgAl ₁₀ O ₁₇ europium-activated phosphor was obtained. It is described that this phosphor has a better coating property on the glass surface than a spherical phosphor having a smooth surface.

The conventional alkaline earth metal aluminate phosphors activated by Eu ²⁺ , Mn ^2+, etc. have high emission brightness, but on the other hand, they deteriorate in the baking process for manufacturing a fluorescent lamp. There is a problem in that the light emission occurs at both ends of the tube (color difference between tube ends). Further, when the fluorescent lamp is continuously turned on, there are problems that the emission brightness is lowered with time and the emission color is changed, and improvement thereof has been desired.

[0008]

Therefore, according to the present invention, the luminous efficiency is high, the baking resistance is good, and when used as the fluorescent film of a fluorescent lamp, the luminous brightness is reduced and the luminescent color is changed with time. Therefore, it is an object of the present invention to provide a method for producing an aluminate phosphor containing Eu ²⁺ as an activator, which is capable of providing a fluorescent lamp having a small amount of color difference and a tube-end color difference less likely to occur.

[0009]

Means for Solving the Problems In the method for producing a phosphor by firing a raw material compound of an aluminate phosphor at a high temperature, the present inventors have studied in detail the firing step, and as a result, at least an Al compound Which is selected from the group consisting of Ba, Sr, and Ca after primary firing of the phosphor raw material with a flux, excluding the compound consisting of one or more elements selected from the group consisting of Ba, Sr, and Ca. By mixing the compound consisting of one or more elements of the following and the remaining raw materials not added during the primary baking with the primary baked product and performing the secondary baking, the luminous efficiency is high and the baking resistance is good, When used as a fluorescent film of a fluorescent lamp, it was found that it is possible to provide an aluminate phosphor having a reduced emission luminance of the fluorescent lamp over time, a change in emission color and a tube end color difference.
The present invention has been completed. The configuration of the present invention is as follows.

(1) A compound of at least one element selected from the group of Ba, Sr and Ca, and a Mg compound or M
a mixture of a g compound and a Zn compound, an Al compound, and E
In a method for producing an aluminate phosphor by firing a u compound or a mixture of an Eu compound and a Mn compound as a phosphor raw material, first, at least the Al compound in the phosphor raw material is included, And the above-mentioned Ba, S
The phosphor raw material excluding the compound of at least one element selected from the group of r and Ca and the flux are mixed and fired.
A method for producing an aluminate phosphor, comprising obtaining a second-baked product, mixing the remaining compound of the phosphor raw material with the first-baked product, and then second-baking the mixture.

(2) The method for producing an aluminate phosphor according to (1) above, wherein the Al compound and the flux are mixed and fired to obtain a primary fired product. (3) A phosphor raw material comprising the Al compound, a mixture of the Eu compound or a Eu compound and a Mn compound, and / or a mixture of the Mg compound or a Mg compound and a Zn compound, and the flux. The method for producing an aluminate phosphor according to the above (1), characterized in that a primary fired product is obtained by mixing and firing.

(4) The flux is at least one selected from the group consisting of aluminum fluoride, boric acid, lithium fluoride and barium fluoride.
(1) The method for producing an aluminate phosphor according to any one of (3) to (3). (5) Any one of (1) to (4) above, wherein the Al compound is γ-alumina or aluminum hydroxide.
The method for producing an aluminate phosphor described in 1. (6) The Al compound has a specific surface area of 10 to 200 m ² / g
The method for producing an aluminate phosphor according to the above (5), characterized in that it is used in the range of

(7) The primary firing temperature is set to 1150 to 165.
The method for producing an alkaline earth metal aluminate phosphor according to any one of (1) to (6) above, characterized in that the temperature is adjusted to 0 ° C, preferably 1200 to 1600 ° C. (8) The method for producing an aluminate phosphor according to any one of (1) to (7), wherein the primary firing is performed in an oxidizing, neutral or reducing atmosphere. (9) The method for producing an alkaline earth metal aluminate phosphor according to the above (8), wherein the reducing atmosphere is a gas containing carbon and / or sulfur elements as constituent components.

(10) The secondary firing temperature is set to 1400 to 165
The method for producing an aluminate phosphor according to any one of (1) to (9) above, wherein the temperature is adjusted to 0 ° C., preferably 1400 to 1600 ° C. (11) The method for producing an aluminate phosphor according to any one of (1) to (10), wherein the secondary firing is performed in a neutral or reducing atmosphere.

(12) The method for producing an alkaline earth metal aluminate phosphor according to the above (11), wherein the neutral atmosphere is nitrogen gas or argon gas. (13) The alkaline earth metal aluminate phosphor according to any one of (1) to (12), wherein the alkaline earth metal aluminate phosphor has a substantially spherical shape. Manufacturing method.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The phosphor material used in the present invention is illustrated below. As the Al compound, A
oxides of l, and, nitrates, carbonates, sulfates, hydroxide thereof
It can be used Al compounds which form oxides by a throat heating. Among them, γ-alumina and aluminum hydroxide are suitable. The specific surface area of Al compounds is 1
A range of 0 to ²⁰⁰ m ² / g is preferable, and a more preferable range is 40 to 150 m ² / g. Eu compound and M
Examples of the n compound include oxides of the above elements and nitrates,
Carbonates, may be used compounds which form oxides sulfates, the oxalates soil heating.

Examples of the Mg compound and Zn compound include oxides of the above elements, nitrates, carbonates, sulfates, and oxalic acid.
It may be used compounds which form oxides by salt soil heating. Ba, as the compound of at least one element selected from the group consisting of Sr and Ca, oxides of the element, and, using nitrates, carbonates, compounds which form oxides by throat heating sulfates You can As the flux, aluminum fluoride, boric acid, lithium fluoride, barium fluoride or the like can be used. Among them, aluminum fluoride is the most suitable.

The method for producing the aluminate phosphor of the present invention is carried out by the following procedure. The present invention always includes an Al compound,
In addition, the phosphor raw material excluding the compound of at least one element selected from the group of Ba, Sr, and Ca is mixed with the flux and fired to obtain a primary fired product, and then the phosphor is added to the primary fired product. the remaining compounds of the raw materials were mixed, further add new flux thereto
The feature is that the second firing is performed without heating. This 2
The significance of stage firing is as follows.

The matrix of the phosphor according to the present invention is an alkaline earth metal aluminate (eg BaMgAl ₁₀ O ₁₇ ) crystal. Since the stable shape of the crystal is a plate, all phosphor raw materials are used. When fired in the presence of a flux, crystal growth is promoted and plate crystals are produced. On the other hand, when a fluorescent lamp is manufactured by applying a three-color mixed phosphor slurry to the inside of a tube, if there is a difference in the sedimentation speed of the phosphor of each color, the mixing ratio of the three-color phosphor between both tube ends of the fluorescent lamp. Fluctuates and causes a color difference. Since the sedimentation behavior of the phosphor particles in the phosphor slurry depends on the particle shape of the phosphor, it is desirable that the phosphor is made into a substantially spherical shape while avoiding an irregular shape such as a plate shape.

When the compound raw material of at least one element selected from the group of Ba, Sr and Ca and the Al compound raw material coexist in a system in which the firing is performed under the flux, it is aimed at the emission brightness and the like. There is a high possibility that compounds having a different composition from those of the above, such as BaAl ₂ O ₄ and Ba ₄ Al ₁₄ O ₂₅ , are generated, and compounds other than the desired alkaline earth metal aluminate are mixed even after secondary firing. As a result, it becomes a factor that deteriorates the light emission characteristics. On the other hand, the phosphor raw material excluding the element selected from the group of Ba, Sr, and Ca forms a solid solution with aluminum relatively easily, so that the composition of the primary fired product under the flux is Can be stabilized. Then, a compound of at least one element selected from the group consisting of Ba, Sr, and Ca and the remaining compound of the phosphor raw material are added to the primary calcined product containing Al, and 2 When the subsequent firing is performed, it is possible to obtain an alkaline earth metal aluminate phosphor having a substantially spherical shape with rounded corners instead of a plate shape.

In the present invention, activators such as Eu and Mn are preferably added during the primary firing. 1 in the presence of flux
The addition of activator in the next firing, it is Rukoto is uniformly diffused throughout the primary fired product. When added at the time of secondary firing, the flux does not exist, so that it becomes difficult to uniformly diffuse it throughout the phosphor that is the secondary fired product, which causes a decrease in various emission characteristics. The addition of Mg, Zn or the like may be performed during the primary firing or during the secondary firing.

The primary firing may be carried out in an oxidizing atmosphere such as air, a neutral atmosphere or a weak reducing atmosphere. The primary firing is performed in the temperature range of 1150 to 1650 ° C. and in the range of 1 to 24 hours depending on the filling amount of the raw material. Preferred firing conditions are 1200 to 1600 ° C. and 1-2.
It's time.

Nitrogen gas, argon gas, etc. are used as the neutral atmosphere in the primary firing, and nitrogen gas, CO containing a small amount of hydrogen gas of about 2% as CO is used as the weak reducing atmosphere.
Although carbon oxides such as x and SOx and oxides of sulfur are used, the emission brightness of the phosphor can be increased by including carbon and sulfur in the constituent components of the gas.

The primary fired product thus obtained is simply crushed and subjected to the secondary firing without washing with water. This primary fired product is secondarily fired by adding and mixing the compound of at least one element selected from the group of Ba, Sr, and Ca with the residue of the phosphor raw material at the time of first firing.

The secondary firing may be performed in either a neutral atmosphere or a weak reducing atmosphere. Secondary firing is 1400-
1 to 24 depending on the filling amount of the raw material in the temperature range of 1650 ° C
Bake for hours. Preferred secondary firing conditions are 1450-16
It is 2-3 hours at 00 ° C.

The secondary fired product obtained by the secondary firing is crushed, washed with water and sieved to obtain the phosphor of the present invention. Thus, the aluminate phosphor obtained by the two-step firing has a rounded shape, has less aggregation, and individual particles are scattered. It emits blue-green light. When this phosphor is applied to a fluorescent lamp, the luminous efficiency is high, the baking resistance is good, and it becomes possible to suppress the deterioration of the emission brightness and the change of the emission color over time. Color difference can be reduced.

[0027]

Example 1 γ-alumina (Al ₂ O ₃ ) 246.75 g (manufactured by Baikowski Ltd., type A125, specific surface area 107 m ² / g) europium oxide (Eu ₂ O ₃ ) 8.516 g manganese dioxide (MnO ₂ ) 0.421 g Aluminum fluoride 0.406 g The above components were thoroughly mixed and filled in an alumina crucible, which was then capped and calcined in air at a temperature of 1450 ° C. for 2 hours to obtain a primary calcined product. It was

The above-mentioned primary calcined product 232.02 g Barium carbonate (BaCO ₃ ) 34.73 g Strontium carbonate (SrCO ₃ ) 32.48 g Magnesium carbonate (MgCO ₃ ) 39.52 g Then, the above components were sufficiently mixed and put into an alumina crucible. A secondary fired product was obtained by filling and firing at a firing temperature of 1550 ° C. for 2 hours in a reducing atmosphere in which hydrogen-containing nitrogen gas was passed.
This secondary fired product was crushed, washed, dried and sieved to obtain the phosphor of Example 1. When the composition of this phosphor was investigated, it was found that Ba _0.4 Sr _0.5 Eu _0.1 Mg _0.99 Mn _0.01 Al
_{It was 10} O ₁₇ and was a rounded Eu ²⁺ and Mn ²⁺ co-activated aluminate blue light emitting phosphor. FIG. 1 is an SEM photograph of this phosphor.

Next, 23% by weight of the blue light emitting aluminate phosphor of Example 1, 44% by weight of trivalent europium-activated yttrium oxide red light emission phosphor (YOX), and cerium and terbium coactivated lanthanum phosphate. 33% by weight of a green light emitting phosphor (LAP) was mixed, and butyl acetate was added together with a nitrocellulose lacquer and sufficiently mixed to prepare a phosphor slurry. This slurry was applied to a glass tube, dried, and then a color temperature of 5000 K was obtained in the same manner as in Example 1 according to a conventional method.
The fluorescent lamp (tube diameter 32 mm, straight tube 20 W) was manufactured.

Example 2 Aluminate Fluorescence of Example 1
Nitrogen gas is used as the firing atmosphere during the primary firing in the production of the body.
Same as Example 1 except that the atmosphere was changed to neutral
Thus, the phosphor of Example 2 was obtained. This phosphor has a composition formula
Is Ba_0.4Sr_0.5Eu_0.1Mg_0.99Mn _0.01Al_TenO
₁₇So, the rounded shape of Eu²⁺And Mn²⁺Co-activity Al
It was a luminate blue light emitting phosphor. Next, of the fluorescent lamp
Production was carried out by replacing the blue light emitting phosphor of Example 1 with that of Example 2.
A blue light emitting phosphor is used, and other conditions are the same as in Example 1.
Then, the fluorescent lamp of Example 2 was manufactured.

Example 3 In the production of the aluminate phosphor of Example 1, the same as the phosphor of Example 1 except that the firing atmosphere during the primary firing was changed to a reducing atmosphere of hydrogen-containing nitrogen gas. Example 3
To obtain a phosphor. The composition formula of this phosphor is Ba _0.4 Sr.
_{It was 0.5} Eu _0.1 Mg _0.99 Mn _0.01 Al ₁₀ O _{17 and} was a rounded Eu ²⁺ and Mn ²⁺ co-activated aluminate blue light emitting phosphor. Next, in the manufacture of the fluorescent lamp, the blue light emitting phosphor of Example 3 was used in place of the blue light emitting phosphor of Example 1, and other conditions were the same as in Example 1
Manufactured fluorescent lamp.

Example 4 γ-Alumina (Al ₂ O ₃ ) 246.75 g (manufactured by Baikowski Ltd., type A125, specific surface area 107 m ² / g) Europium oxide (Eu ₂ O ₃ ) 8.516 g manganese dioxide ( MnO ₂ ) 0.421 g Aluminum Fluoride (AlF ₃ ) 0.406 g The above components were sufficiently mixed and filled in an alumina crucible, and separately from this, a container filled with a mass of graphite and a container filled with sulfur powder were heat-resistant. Put in line in a container, cover with a lid and ventilate nitrogen gas containing hydrogen to perform primary firing in a reducing atmosphere,
The other conditions were the same as in Example 1 to obtain the phosphor of Example 4. This phosphor has a composition formula of Ba _0.4 Sr _0.5 Eu.
_{It was 0.1} Mg _0.99 Mn _0.01 Al ₁₀ O _{17 and} was a rounded shape of Eu ²⁺ and Mn ²⁺ co-activated aluminate blue light emitting phosphor. Next, in the fluorescent lamp, the blue light emitting phosphor of Example 1 was used in place of the blue light emitting phosphor of Example 1, and the other conditions were the same as in Example 1 to manufacture the fluorescent lamp of Example 4.

Example 5 In the production of the aluminate phosphor of Example 3, γ-alumina (manufactured by Baikowski,
Aluminum hydroxide (Al (OH) ₃ ) (made by Iwatani Chemical Co., Ltd., in place of type A125, specific surface area 107 m ² / g)
Type RH40, specific surface area 46m ² / g) 333.0
A phosphor of Example 5 was obtained in the same manner as in Example 3 except that 5 g was blended. The composition of this phosphor is Ba _0.4 Sr _0.5 E
It was u _0.1 Mg _0.99 Mn _0.01 Al ₁₀ O ₁₇ , and was a rounded Eu ²⁺ and Mn ²⁺ co-activated aluminate blue light emitting phosphor. Next, for the fluorescent lamp, the blue light emitting phosphor of Example 5 was used in place of the blue light emitting phosphor of Example 1,
The other conditions were the same as in Example 1 to manufacture the fluorescent lamp of Example 5.

(Example 6) γ-alumina (Al ₂ O ₃ ) 246.75 g (manufactured by Baikowski Ltd., type A125, specific surface area 107 m ² / g) magnesium carbonate (MgCO ₃ ) 43.48 g aluminum fluoride (AlF) ₃ ) 0.406 g The above components were sufficiently mixed, filled in an alumina crucible, covered with a lid, and fired in air at a temperature of 1450 ° C. for 2 hours to obtain a primary fired product.

The above primary calcined product 243.21 g Barium carbonate (BaCO ₃ ) 34.73 g Strontium carbonate (SrCO ₃ ) 32.48 g Europium oxide (Eu ₂ O ₃ ) 7.742 g Manganese dioxide (MnO ₂ ) 0.383 g , The above components are sufficiently mixed and filled in an alumina crucible, and the mixture is fired at a firing temperature of 1550 ° C. for 2 hours in a reducing atmosphere in which hydrogen-containing nitrogen gas is passed to obtain a secondary fired product,
The phosphor of Example 6 was obtained by treating in the same manner as in Example 1. The composition of this phosphor is Ba _0.4 Sr _0.5 Eu _0.1 Mg _0.99 M
It was n _0.01 Al ₁₀ O ₁₇ , and was a rounded Eu ²⁺ and Mn ²⁺ co-activated aluminate blue light emitting phosphor.
Next, in the manufacture of the fluorescent lamp, the blue light-emitting phosphor of Example 6 was used in place of the blue light-emitting phosphor of Example 1, and the other conditions were the same as in Example 1 to manufacture the fluorescent lamp of Example 6. did.

(Example 7) γ-alumina (Al ₂ O ₃ ) 246.75 g (Baikousky's type A125, specific surface area 107 m ² / g) Aluminum fluoride 0.406 g The above components were thoroughly mixed. The alumina crucible was filled, covered with a lid, and fired in air at a temperature of 1450 ° C. for 2 hours to obtain a primary fired product.

The above-mentioned primary calcined product 224.32 g Barium carbonate (BaCO ₃ ) 34.73 g Strontium carbonate (SrCO ₃ ) 32.48 g Magnesium carbonate (MgCO ₃ ) 39.52 g Europium oxide (Eu ₂ O ₃ ) 7.742 g Dioxide 0.383 g of manganese (MnO ₂ ) Next, the above components were sufficiently mixed and filled in an alumina crucible, and the mixture was fired at a firing temperature of 1550 ° C. for 2 hours in a reducing atmosphere in which hydrogen-containing nitrogen gas was aerated to obtain a secondary fired product. Got
The phosphor of Example 7 was obtained by treating in the same manner as in Example 1. The composition of this phosphor is Ba _0.4 Sr _0.5 Eu _0.1 Mg _0.99 M
It was n _0.01 Al ₁₀ O ₁₇ , and was a rounded Eu ²⁺ and Mn ²⁺ co-activated aluminate blue light emitting phosphor.
FIG. 2 is an SEM photograph of this phosphor. Next, in the manufacture of the fluorescent lamp, the blue light emitting phosphor of Example 1 was used in place of the blue light emitting phosphor of Example 1, and the other conditions were the same as in Example 1 to manufacture the fluorescent lamp of Example 7. did.

[0038] [Comparative Example 1]   γ-alumina (Al₂O₃) 224.32g   (Baikousky type A125, specific surface area 107m²/ G)   Barium carbonate (BaCO₃) 34.733 g   Strontium carbonate (SrCO₃) 32.478 g   Magnesium carbonate (MgCO₃) 39.522g   Europium oxide (Eu₂O₃) 7.742 g   Manganese dioxide (MnO₂) 0.383 g   Aluminum Fluoride (AlF₃) 0.369g The above raw materials are thoroughly mixed and filled in an alumina crucible, and
Firing at a firing temperature of 1550 ° C for 2 hours in a nitrogen-containing gas atmosphere
did. Then, the fired product is crushed, washed, dried and sieved.
By processing, the phosphor of Comparative Example 1 was obtained. This phosphor has a composition
The formula is Ba_0.4Sr_0.5Eu_0.1Mg_0.99Mn_0.01Al _Ten
O₁₇Eu, which is the fusion or aggregation of plate-shaped particles²⁺And Mn
²⁺Co-activated barium strontium magnesium aluminum
It was an acid blue emitting phosphor. Figure 3 shows the SE of this phosphor.
It is an M photograph. Next, the fluorescent lamp emits the blue light of Example 1.
The blue light emitting phosphor of Comparative Example 1 was used instead of the photophosphor.
The other conditions are the same as in Example 1, and the fluorescent run of Comparative Example 1 is used.
Manufactured.

[Comparative Example 2] In the production of the aluminate phosphor of Comparative Example 1, γ-alumina (manufactured by Baikowski,
Type A 125, specific surface area 107 m ² / g) in place of α
A phosphor of Comparative Example 2 was obtained in the same manner as in Comparative Example 1 except that alumina (type RA40-12, manufactured by Iwatani Chemical Co., Ltd., specific surface area 4.7 m ² / g) was used. The composition of this phosphor is
Ba _0.4 Sr _0.5 Eu _0.1 Mg _0.99 Mn _0.01 Al ₁₀ O ₁₇
And the plate-like particles were a co-activated aluminate blue light-emitting phosphor of Eu ²⁺ and Mn ²⁺ . Next, the fluorescent lamp of Comparative Example 2 was manufactured in the same manner as in Example 1 except that the blue emitting phosphor of Comparative Example 2 was used instead of the blue emitting phosphor of Example 1 in the fluorescent lamp.

[Comparative Example 3] In the production of the aluminate phosphor of Comparative Example 1, aluminum fluoride (A
lF ₃₎ except omitting the in the same manner as in Comparative Example 1, to obtain a phosphor of Comparative Example 3. The composition of this phosphor is Ba _0.4 Sr.
_{It was 0.5} Eu _0.1 Mg _0.99 Mn _0.01 Al ₁₀ O ₁₇ , and was a co-activated aluminate blue light emitting phosphor of Eu ²⁺ and Mn ²⁺ in which tabular particles were aggregated. FIG. 4 is a SEM photograph of this phosphor. Next, as the fluorescent lamp, the blue light emitting phosphor of Comparative Example 3 was used in place of the blue light emitting phosphor of Example 1, and the other conditions were the same as in Example 1 to manufacture the fluorescent lamp of Comparative Example 3.

Comparative Example 4 γ-Alumina (Al ₂ O ₃ ) 246.75 g (manufactured by Baikousky, type A125, specific surface area 107 m ² / g) Barium carbonate (BaCO ₃ ) 38.207 g Strontium carbonate (SrCO _3). ) 35.727 g Aluminum Fluoride (AlF ₃ ) 0.406 g The above ingredients were thoroughly mixed and filled in an alumina crucible, which was then capped and fired in air at a firing temperature of 1450 ° C. for 2 hours to obtain a primary fired product. Obtained.

The above-mentioned primary calcined product 274.10 g Magnesium carbonate (MgCO ₃ ) 39.522 g Europium oxide (Eu ₂ O ₃ ) 7.742 g Manganese dioxide (MnO ₂ ) 0.383 g The above raw materials were sufficiently mixed into an alumina crucible. Filled with hydrogen
A secondary fired product was obtained by firing in a nitrogen-containing gas atmosphere at a firing temperature of 1550 ° C. for 2 hours. This fired product was treated in the same manner as in Example 1 to obtain the phosphor of Comparative Example 4. The composition formula of this phosphor is Ba _0.4 Sr _0.5 Eu _0.1 Mg _0.99 Mn _0.01 Al ₁₀
In O _17, it was aggregated Eu ²⁺ and Mn ²⁺ coactivated barium strontium magnesium aluminate blue light emitting phosphor plate-like particles. Next, the fluorescent lamp of Comparative Example 4 was manufactured in the same manner as in Example 1 except that the blue emitting phosphor of Comparative Example 4 was used instead of the blue emitting phosphor of Example 1 in the fluorescent lamp.

Comparative Example 5 γ-alumina (Al ₂ O ₃ ) 246.75 g (manufactured by Baikowski Ltd., type A125, specific surface area 107 m ² / g) Barium carbonate (BaCO ₃ ) 38.207 g Strontium carbonate (SrCO _3). ) 35.727 g Magnesium carbonate (MgCO ₃ ) 43.48 g Aluminum fluoride (AlF ₃ ) 0.406 g The above components were thoroughly mixed and charged in an alumina crucible, and the mixture was covered with air and baked at a temperature of 1450 ° C. for 2 hours. It was fired for a time to obtain a primary fired product.

The above-mentioned primary calcined product 292.99 g Europium oxide (Eu ₂ O ₃ ) 7.742 g Manganese dioxide (MnO ₂ ) 0.383 g The above raw materials were sufficiently mixed and filled in an alumina crucible to contain hydrogen.
A secondary fired product was obtained by firing in a nitrogen-containing gas atmosphere at a firing temperature of 1550 ° C. for 2 hours. This fired product was treated in the same manner as in Example 1 to obtain the phosphor of Comparative Example 5. The composition formula of this phosphor is Ba _0.4 Sr _0.5 Eu _0.1 Mg _0.99 Mn _0.01 Al ₁₀
In O _17, the shape is a plate-like Eu ²⁺ and Mn ²⁺ coactivated barium strontium magnesium aluminate blue light emitting phosphor. Next, as the fluorescent lamp, the blue light emitting phosphor of Comparative Example 5 was used in place of the blue light emitting phosphor of Example 1, and the other conditions were the same as in Example 1 to manufacture the fluorescent lamp of Comparative Example 5.

(Average Particle Diameter of Phosphor)
7 to 7 and Comparative Examples 1 to 5, the raw materials, the firing atmosphere, and the average particle diameter of the phosphors during the primary and secondary firings are described. The approximate shape of the phosphor is the result of observation with a scanning electron microscope (SEM), and the average particle size was measured by an air permeation method using a Fisher particle sizer (Fisher Subsieve Sizer, manufactured by Fisher Co.).

(Characteristic Evaluation of Phosphor and Fluorescent Lamp) The phosphors of Examples 1 to 7 and Comparative Examples 1 to 5 were prepared using 253.
It was excited by 7 nm ultraviolet light to emit light, and the emission efficiency of each phosphor at that time, the emission color (chromaticity point by the CIA color system) and the maintenance rate of the emission efficiency after baking were measured and shown in Table 2. . In Table 2, the luminous efficiency of the phosphor particles is a value obtained by dividing the emission luminance of each phosphor by the y value of its chromaticity (luminance / y value).
Is obtained and is a relative percentage with respect to the luminous efficiency (luminance / y value) of the aluminate phosphor manufactured by the conventional manufacturing method. The luminous efficiency maintenance rate after baking was about 650 ° C. for each phosphor in an air atmosphere.
The luminous efficiency when each phosphor was heated at 25 ° C. for 15 minutes and then cooled to room temperature was excited by 253.7 nm ultraviolet light.
It is the percentage when divided by the y value).

Further, the obtained Examples 1 to 7 and Comparative Example 1 were obtained.
With respect to the fluorescent lamps Nos. 5 to 5, the luminous flux (initial luminous flux) immediately after lighting, the luminous flux maintenance factor, the temporal change of the emission color and the tube end color difference were measured and shown in Table 3. In Table 3, the value of the initial luminous flux of the lamp is measured by measuring the luminous efficiency (luminance / y value) of each fluorescent lamp when the lamp is first turned on after manufacturing, and the aluminate phosphor obtained by the conventional manufacturing method is blue. It is a percentage with respect to the luminous efficiency (luminance / y value) of a conventional three-color mixed fluorescent lamp used as a luminescent component phosphor.

The luminous flux maintenance factor is 1 for each fluorescent lamp.
It is a value showing the luminous efficiency (luminance / y value) of the fluorescent lamp at the time of continuous lighting for 000 hours as a relative percentage with respect to the luminous efficiency (luminance / y value) immediately after lighting of each fluorescent lamp. The change with time of the luminescent color is the difference (Δx) in the x value (Δx) and the difference (Δy) in the y value of the luminescent chromaticity points when the fluorescent lamp is first lit for 1000 hours and after it is lit for 1000 hours.
Further, the tube end color difference (ΔA) is a difference in emission color at 8 cm from both ends of each fluorescent lamp, and the emission chromaticity of emission at 8 cm from both ends of the fluorescent lamp is (x ₁ , y). ₁ ) and (x ₂ , y ₂ ), ΔA = {(x ₁ −x ₂ ) ² + (y ₁ −y ₂ ) ² }
It is a value defined by ^1/2 .

[0049]

[Table 1]

[0050]

[Table 2]

[0051]

[Table 3]

(Results) As can be seen from Table 1, for the phosphor particles, after at least the Al compound in the phosphor raw material is primarily fired together with the flux, at least one selected from the group consisting of Ba, Sr and Ca. The phosphors of Examples 1 to 7 in which the compound of one element was mixed with the remaining raw material that was not compounded during the primary firing and the secondary firing was performed, the appearance is almost spherical and rounded. On the other hand, the phosphors of Comparative Examples 1 to 5 were aggregates of plate-like particles.

As can be seen from Table 2, the luminous efficiency of the phosphor particles of Examples 1 to 7 is equal to or higher than that of Comparative Example 1 which is a conventional example, and the maintenance rate of the luminous efficiency after baking is Comparative Example 1. It can be seen that there is a considerable improvement over ~ 5.

As can be seen from Table 3, the fluorescent lamps of Examples 1 to 7 using the aluminate phosphor of the Example as the blue light emitting component phosphor of the three-wavelength type fluorescent lamp are the same as those of Comparative Examples 1 to 1.
The initial luminous flux values were all higher than those of the fluorescent lamps of No. 5. In addition, the luminous flux maintenance rates of the fluorescent lamps of Examples 1 to 7 when continuously lit for a certain period of time are larger than those of the fluorescent lamps of Comparative Examples 1 to 5, and in addition, the luminescent color over time due to continuous lighting. The changes in the values all showed small values. Furthermore, the fluorescent lamps of Examples 1 to 7 have a tube end color difference of Comparative Example 1.
It was possible to significantly reduce it compared with the fluorescent lamps of ~ 5.

[0055]

INDUSTRIAL APPLICABILITY The present invention adopts the above-mentioned constitution, and particularly B
Primary firing is performed by mixing the phosphor raw material excluding compounds such as a, Sr, and Ca with the flux and firing, and the remaining phosphor raw material is newly added.
It is possible to provide an aluminate phosphor that has a rounded shape with almost no aggregation and has a high luminous efficiency and a high luminous efficiency maintenance rate after heat treatment, by performing a secondary baking in which no flux is added to Became. Further, when such a phosphor is applied as a blue phosphor of a three-wavelength band emission type fluorescent lamp, the efficiency is high, and there is little deterioration in emission efficiency with time or change in emission color, and the emission color at both ends of the fluorescent lamp is reduced. It has become possible to provide a blue phosphor for a three-wavelength band emission type fluorescent lamp with a small difference, high color rendering and high efficiency.

[Brief description of drawings]

FIG. 1 is an electron micrograph of an aluminate phosphor manufactured in Example 1. The magnification is 800 times.

FIG. 2 is an electron micrograph of an aluminate phosphor manufactured in Example 7. The magnification is 800 times.

FIG. 3 is an electron micrograph of an aluminate phosphor manufactured in Comparative Example 1. The magnification is 800 times.

4 is an electron micrograph of an aluminate phosphor manufactured in Comparative Example 3. FIG. The magnification is 800 times.

─────────────────────────────────────────────────── --- Continuation of the front page (56) Reference JP-A-56-116778 (JP, A) JP-A-10-223370 (JP, A) JP-A-59-36183 (JP, A) JP-A-49- 184 (JP, A) JP 63-265990 (JP, A) JP 11-158464 (JP, A) JP 48-95387 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09K 11/08-11/89

Claims (5)

(57) [Claims] 1. A compound of at least one element selected from the group of Ba, Sr and Ca, and a Mg compound or Mg.
A mixture of a compound and a Zn compound, an Al compound, and Eu
In a method for producing a aluminate phosphor by firing a compound or a mixture of an Eu compound and a Mn compound as a phosphor raw material, first, at least the Al compound in the phosphor raw material is included, and The above Ba, Sr
After mixing the phosphor raw material excluding the compound of the element selected from the group of Ca and Ca and the flux to obtain a primary fired product,
A method for producing an aluminate phosphor, characterized in that the primary calcination product is mixed with the remaining compound of the phosphor raw material and secondarily calcinated. 2. The method for producing an aluminate phosphor according to claim 1, wherein the Al compound and the flux are mixed and fired to obtain a primary fired product. 3. A phosphor raw material comprising the Al compound, the Eu compound or the mixture of the Eu compound and the Mn compound, and / or the Mg compound or the mixture of the Mg compound and the Zn compound, and the flux. The method for producing an aluminate phosphor according to claim 1, wherein the primary fired product is obtained by mixing and firing. 4. The flux is aluminum fluoride, boric acid,
2. At least one selected from the group consisting of lithium fluoride and barium fluoride.
4. The method for producing an aluminate phosphor according to any one of 1 to 3. 5. The method for producing an aluminate phosphor according to claim 1, wherein the Al compound is γ-alumina or aluminum hydroxide.