JP2002249766A - Method for producing aluminate phosphor - Google Patents

Abstract

(57) [Summary] [Problems] High luminous efficiency, good baking resistance,
A method for producing an aluminate phosphor containing Eu ²⁺ as an activator, which can provide a fluorescent lamp with less decrease in emission luminance and little change in emission color over time when used as a fluorescent film of a fluorescent lamp It is intended to provide. SOLUTION: In a method for producing an aluminate phosphor, a compound such as Ba, Sr, Ca, etc., a Mg, Zn compound, an Al compound, and an Eu, Mn compound are used as phosphor raw materials, and these are calcined. , A phosphor material containing an Al compound and excluding compounds such as Ba, Sr, and Ca, and a flux are mixed and fired to obtain a primary fired material, and then the primary fired material is treated with the remaining phosphor material remaining. A method for producing an aluminate phosphor, comprising mixing a compound and performing secondary firing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing an aluminate phosphor. Specifically, divalent europium (Eu ²⁺ ) or Eu ²⁺ and divalent europium (Eu ²⁺ ) which can provide a high-luminance phosphor film with high luminance, little decrease in luminance over time, and a high phosphor filling density.
The present invention relates to a method for producing a blue to blue-green luminescent alkaline earth metal aluminate phosphor activated with manganese (Mn ²⁺ ).

[0002]

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

However, the conventional Eu ²⁺ activated or Eu ²⁺ and Mn ²⁺ co-activated alkaline earth metal aluminate phosphor has a non-uniform particle size and a plate-like particle shape. Because of the tendency of agglomeration, the fluorescent film using this had a poor filling rate of the phosphor in the film, and the fluorescent film was also non-uniform.

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

As a method for producing the phosphor, a method of melting a phosphor raw material with plasma and condensing the same into spherical particles (see Japanese Patent Publication No. 7-45655) is known. A method has been proposed in which these droplets are instantaneously frozen and then heated (see Japanese Patent Application Laid-Open No. 9-291275). However, none of them has a low production efficiency and is not suitable for industrial production.

Japanese Unexamined Patent Publication No. Hei 11-199867 discloses that particles having a uniform long axis diameter and aluminum oxide having an aspect ratio close to 1 are substantially spherical, amorphous barium carbonate, amorphous europium oxide and amorphous. By firing the raw material mixture consisting of basic magnesium carbonate, a maximum of 1μ
m about _0.9 m, and as a whole, approximately spherical Ba _0.9 E
It is described that u _0.1 MgAl ₁₀ O ₁₇ europium activated phosphor was obtained. It is described that this phosphor has better applicability to a glass surface than a spherical phosphor having a smooth surface.

[0007] The conventional alkaline earth metal aluminate phosphor activated with Eu ²⁺ , Mn ^2+, etc. has a high luminous luminance, but the luminance is deteriorated in a baking process for producing a fluorescent lamp. And the phenomenon that the emission colors differ at both ends of the tube (tube end color difference) occurs. In addition, when the fluorescent lamp is continuously turned on, there is a problem that the emission luminance decreases over time or the emission color changes, and improvement thereof has been desired.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a light-emitting device having high luminous efficiency, good baking resistance, and a decrease in luminous luminance and a change in luminous color over time when used as a fluorescent film of a fluorescent lamp. It is an object of the present invention to provide a method for producing an aluminate phosphor containing Eu ²⁺ as an activator, which can provide a fluorescent lamp which has a small amount of light and hardly causes a tube end color difference.

[0009]

Means for Solving the Problems The present inventors have studied in detail the firing step in a method of manufacturing a phosphor by firing a starting compound of an aluminate phosphor at a high temperature. After primary calcination of a phosphor raw material together with a flux, excluding a compound comprising at least one element selected from the group consisting of Ba, Sr and Ca, the phosphor raw material is selected from the group consisting of Ba, Sr and Ca. By mixing the compound consisting of one or more elements and the remaining raw materials not added during the primary firing into the primary fired product and performing the secondary firing, the luminous efficiency is high, the baking resistance is good, When used as a fluorescent film of a fluorescent lamp, it has been found that it is possible to provide an aluminate phosphor with a decrease in emission luminance over time of the fluorescent lamp and a change in emission color and a small 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 consisting of Ba, Sr and Ca, a Mg compound or M
a mixture of a g compound and a Zn compound, an Al compound,
In a method for producing an aluminate phosphor by sintering a mixture of a u compound or an Eu compound and a Mn compound as a phosphor raw material, first, the phosphor raw material contains at least the Al compound, And the aforementioned Ba and S
a mixture of a phosphor material excluding a compound of at least one element selected from the group consisting of
A method for producing an aluminate phosphor, comprising: after obtaining a second fired product, mixing the remaining compound of the phosphor raw material into the first fired material and performing second firing.

(2) The method for producing an aluminate phosphor according to (1), wherein the Al compound and the flux are mixed and fired to obtain a first fired material. (3) a phosphor raw material comprising the Al compound, the Eu compound or a mixture of the Eu compound and the Mn compound, and / or the Mg compound or a mixture of the Mg compound and the Zn compound, and the flux; The method for producing an aluminate phosphor according to the above (1), wherein 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 (1) to (3). (5) Any one of the above (1) to (4), wherein the Al compound is γ-alumina or aluminum hydroxide.
5. A method for producing an aluminate phosphor according to any one of the above. (6) The Al compound has a specific surface area of 10 to 200 m ² / g.
(5) The method for producing an aluminate phosphor according to the above (5), wherein the phosphor of the present invention is used.

(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 the above (1) to (6), wherein 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 (8), wherein the reducing atmosphere is a gas containing carbon and / or sulfur as a constituent.

(10) The secondary firing temperature is set to 1400 to 165.
The method for producing an aluminate phosphor according to any one of the above (1) to (9), 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 a nitrogen gas or an argon gas. (13) The alkaline earth metal aluminate phosphor according to any one of (1) to (12), wherein the shape of the alkaline earth metal aluminate phosphor is substantially spherical. Manufacturing method.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The phosphor materials used in the present invention are exemplified as follows. As Al compounds, oxides and nitrates of Al,
Al compounds that generate oxides by heating, such as carbonates, sulfates, hydroxides, and halides, can be used. Among them, gamma alumina and aluminum hydroxide are suitable. The Al compound has a specific surface area of 10 to 200.
The range of m ² / g is preferred, and the more preferred range is 40 to
150 m ² / g. As the Eu compound and the Mn compound, oxides of the above-mentioned elements and compounds that generate oxides by heating, such as nitrates, carbonates, sulfates, oxalates, and halides, can be used.

As the Mg compound and the Zn compound, there can be used oxides of the above-mentioned elements and compounds which form oxides by heating, such as nitrates, carbonates, sulfates, oxalates and halides. At least one selected from the group consisting of Ba, Sr and Ca
As the compound of the kind of element, an oxide of the element, and
Compounds that generate oxides by heating, such as nitrates, carbonates, sulfates, and halides, can be used. As the flux, aluminum fluoride, boric acid, lithium fluoride, barium fluoride, or the like can be used.
Among them, aluminum fluoride is most suitable.

The method for producing the aluminate phosphor of the present invention is performed according to the following procedure. The present invention always includes an Al compound,
A phosphor material excluding a compound of at least one element selected from the group consisting of Ba, Sr and Ca is mixed with a flux and fired to obtain a first fired material. It is characterized in that the remaining compounds of the raw materials are mixed and subjected to secondary firing in the absence of a flux. The significance of this two-stage firing is as follows.

The base material of the phosphor according to the present invention is an alkaline earth metal aluminate (for example, BaMgAl ₁₀ O ₁₇ ) crystal, but since the stable shape of the crystal is plate-like, all the phosphor raw materials are used. When calcined in the presence of a flux, crystal growth is promoted and plate-like crystals are formed. On the other hand, when a three-color mixed phosphor slurry is applied in a tube to produce a fluorescent lamp, if there is a difference in the sedimentation speed of the phosphor of each color, the mixing ratio of the three-color phosphor at the tube end of the fluorescent lamp fluctuates. There is a problem that a color difference occurs. Since the sedimentation behavior of the phosphor particles in the phosphor slurry depends on the particle shape of the phosphor, it is desired that the phosphor should be substantially spherical, avoiding a plate-like or other irregular shape.

Further, when sintering under a flux in a system in which a compound raw material of at least one element selected from the group consisting of Ba, Sr, and Ca and a raw material of an Al compound coexist, a desired emission luminance and the like can be obtained. It is likely to produce compounds having different compositions from those, for example, BaAl ₂ O ₄ and Ba ₄ Al ₁₄ O ₂₅ , and compounds other than the target alkaline earth metal aluminate are mixed even after secondary firing. As a result, it becomes a factor of deteriorating the light emission characteristics. On the other hand, since the phosphor raw material excluding elements selected from the group consisting of Ba, Sr and Ca relatively easily forms a solid solution with aluminum, the composition of the primary fired material under a flux is relatively low. 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 fired product containing Al, and the compound is added in the absence of a flux. At the time of the subsequent firing, an alkaline earth metal aluminate phosphor having not a plate shape but a substantially spherical shape with sharp corners can be obtained.

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

The primary firing may be performed in an oxidizing atmosphere such as air, a neutral atmosphere, or a weak reducing atmosphere. The primary firing is performed at a temperature in the range of 1150 to 1650 ° C. and for a time 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 to 2
Time.

As the neutral atmosphere in the first firing, nitrogen gas, argon gas or the like is used. As the weak reducing atmosphere, nitrogen gas containing a small amount of hydrogen gas of about 2%, CO 2
Although an oxide gas of carbon or sulfur such as x or SOx is used, the emission luminance of the phosphor can be increased by including carbon or sulfur in the constituent components of the gas.

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

The secondary firing may be performed in a neutral atmosphere or a weakly reducing atmosphere. The second firing is 1400
In the temperature range of 1650 ° C., 1 to 24
Bake for hours. Preferred secondary firing conditions are 1450 to 16
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. The aluminate phosphor thus obtained by the two-stage baking has a rounded shape, is less agglomerated and individual particles are dispersed, and is excited by vacuum ultraviolet rays or ultraviolet rays to obtain a high-brightness blue or Emit blue-green light. When this phosphor is applied to a fluorescent lamp, the luminous efficiency is high, the baking resistance is good, and it is possible to suppress a decrease in luminous brightness and a change in luminescent color over time. The color difference can be reduced.

[0027]

EXAMPLES (Example 1) 246.75 g of γ-alumina (Al ₂ O ₃ ) (manufactured by Baikovsky, 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 sufficiently mixed, filled into an alumina crucible, covered, and fired in air at a temperature of 1450 ° C. for 2 hours to obtain a primary fired product. Was.

The above-mentioned first 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 mixed into an alumina crucible. It was filled and fired at a firing temperature of 1550 ° C. for 2 hours in a reducing atmosphere through which a hydrogen-containing nitrogen gas was passed to obtain a secondary fired product.
The secondary fired product was crushed, washed, dried, and sieved to obtain a phosphor of Example 1. When the composition of this phosphor was examined, 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 shape Eu ²⁺ and Mn ²⁺ coactivated aluminate blue light emitting phosphor. FIG. 1 is a SEM photograph of this phosphor.

Next, the blue-emitting aluminate phosphor of Example 1 was 23% by weight, the trivalent europium-activated yttrium oxide red-emitting phosphor (YOX) was 44% by weight, and cerium and terbium-activated lanthanum phosphate were used. 33% by weight of a green light-emitting phosphor (LAP) was mixed, butyl acetate was added together with a nitrocellulose lacquer, and the mixture was sufficiently mixed to prepare a phosphor slurry. This slurry was applied to a glass tube and dried.
(Tube diameter 32 mm, straight tube 20 W) was manufactured.

(Example 2) Aluminate fluorescence of Example 1
In the production of the body, the firing atmosphere during the primary firing is nitrogen gas
Same as the phosphor of Example 1 except that the neutral atmosphere was changed to
Thus, the phosphor of Example 2 was obtained. This phosphor has the composition formula
Is Ba_0.4Sr_0.5Eu_0.1Mg_0.99Mn _0.01Al_TenO
₁₇The rounded shape of Eu²⁺And Mn²⁺Co-activation
It was a phosphoric acid blue light emitting phosphor. Next, the fluorescent lamp
The production was performed in the same manner as in Example 2 except that the blue light-emitting phosphor of Example 1 was used.
A blue light-emitting phosphor was used, and other conditions were the same as in Example 1.
Thus, the fluorescent lamp of Example 2 was manufactured.

Example 3 In the manufacture of the aluminate phosphor of Example 1, the same as the phosphor of Example 1 except that the firing atmosphere during the first firing was changed to a reducing atmosphere of hydrogen-containing nitrogen gas. Thus, the phosphor of Example 2 was obtained. This phosphor composition formula _{Ba 0.4 Sr 0.5 Eu 0.1 Mg 0.99} Mn
_0.01 Al ₁₀ O ₁₇ , rounded Eu ²⁺ and Mn
^{It was a 2+} co-activated aluminate blue light emitting phosphor. next,
For 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 the other conditions were the same as in Example 1 to manufacture the fluorescent lamp of Example 3.

Example 4 246.75 g of γ-alumina (Al ₂ O ₃ ) (manufactured by Baikowski Co., 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 charged into an alumina crucible, and separately heat-resistant together with a container filled with a lump of graphite and a container filled with sulfur powder. Are placed side by side in a neutral container, covered with a hydrogen gas containing nitrogen gas, and first fired in a reducing atmosphere.
Other conditions were the same as in Example 1 to obtain a phosphor of Example 4. This phosphor composition formula of Ba _0.4 Sr _0.5 Eu
_It was a Eu ²⁺ and Mn ²⁺ co-activated aluminate blue light-emitting phosphor having a rounded shape of _0.1 Mg _0.99 Mn _0.01 Al ₁₀ O ₁₇ . Next, as the fluorescent lamp, the blue light emitting phosphor of Example 4 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 produce a fluorescent lamp of Example 4.

Example 5 In the production of the aluminate phosphor of Example 3, γ-alumina (manufactured by Baikovsky,
Aluminum hydroxide (Al (OH) ₃ ) (manufactured by Iwatani Chemical Co., Ltd.) in place of type A125, specific surface area 107 m ² / g
Type RH40, specific surface area 46 m 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
u _0.1 Mg _0.99 Mn _0.01 Al ₁₀ O ₁₇ , which was a rounded Eu ²⁺ and Mn ²⁺ co-activated aluminate blue light emitting phosphor. Next, the fluorescent lamp uses the blue light emitting phosphor of the fifth embodiment instead of the blue light emitting phosphor of the first embodiment,
The other conditions were the same as in Example 1 to produce a fluorescent lamp of Example 5.

Example 6 γ-Alumina (Al ₂ O ₃ ) 246.75 g (manufactured by Baikowski Co., 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, charged into an alumina crucible, covered, and fired in air at a temperature of 1450 ° C. for 2 hours to obtain a primary fired product.

The above-mentioned primary fired 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 were sufficiently mixed, filled in an alumina crucible, and fired at a firing temperature of 1550 ° C. for 2 hours in a reducing atmosphere through which hydrogen-containing nitrogen gas was passed to obtain a secondary fired product.
The same treatment as in Example 1 was performed to obtain a phosphor of Example 6. The composition of the phosphor is _{Ba 0.4 Sr 0.5 Eu 0.1 Mg 0.99} M
n _0.01 Al ₁₀ O ₁₇ , and a rounded Eu ²⁺ and Mn ²⁺ co-activated aluminate blue light-emitting phosphor.
Next, the manufacture of the fluorescent lamp uses the blue light emitting phosphor of Example 6 in place of the blue light emitting phosphor of Example 1 and manufactures the fluorescent lamp of Example 6 in the other conditions in the same manner as in Example 1. did.

(Example 7) 246.75 g of γ-alumina (Al ₂ O ₃ ) (manufactured by Baikowski Co., Ltd., type A125, specific surface area 107 m ² / g) Aluminum fluoride 0.406 g The above components were sufficiently mixed. It was filled in an alumina crucible, covered, and fired in air at a temperature of 1450 ° C. for 2 hours to obtain a primary fired product.

The above primary fired 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 Manganese (MnO ₂ ) 0.383 g Next, the above components were sufficiently mixed, filled in an alumina crucible, and fired at a firing temperature of 1550 ° C. for 2 hours in a reducing atmosphere through which a hydrogen-containing nitrogen gas was passed to form a second fired product. Get
The same procedure as in Example 1 was carried out to obtain a phosphor of Example 7. The composition of the phosphor is _{Ba 0.4 Sr 0.5 Eu 0.1 Mg 0.99} M
n _0.01 Al ₁₀ O ₁₇ , and a rounded Eu ²⁺ and Mn ²⁺ co-activated aluminate blue light-emitting phosphor.
FIG. 2 is an SEM photograph of the phosphor. Next, in manufacturing the fluorescent lamp, the blue light emitting phosphor of Example 7 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.

Comparative Example 1 γ Alumina (Al_TwoO_Three224.32 g (manufactured by Baikovsky, type A125, specific surface area 107 m)^Two/ G) barium carbonate (BaCO_Three34.733 g strontium carbonate (SrCO_Three) 32.478 g magnesium carbonate (MgCO_Three) 39.522 g Europium oxide (Eu_TwoO_Three7.742 g manganese dioxide (MnO)_Two) 0.383 g aluminum fluoride (AlF_Three) 0.369 g The above raw materials were mixed well, and charged into an alumina crucible.
Firing at 1550 ° C for 2 hours in a nitrogen-containing gas atmosphere
did. Next, the fired product is crushed, washed, dried, and sieved.
By performing the treatment, the phosphor of Comparative Example 1 was obtained. This phosphor has the composition
The formula is Ba_0.4Sr_0.5Eu_0.1Mg_0.99Mn_0.01Al _Ten
O₁₇In the above, Eu in which plate-like particles are fused or aggregated²⁺And Mn
²⁺Co-activated barium strontium magnesium aluminum
It was a phosphoric acid blue light emitting phosphor. FIG. 3 shows the SE of this phosphor.
It is an M photograph. Next, the fluorescent lamp emits blue light according to the first embodiment.
The blue light emitting phosphor of Comparative Example 1 was used in place of the light phosphor,
The other conditions were the same as in Example 1, and the fluorescent lamp of Comparative Example 1 was used.
Manufactured.

Comparative Example 2 In the production of the aluminate phosphor of Comparative Example 1, γ-alumina (by Baikowski,
Α instead of type A125, specific surface area 107 m ² / g)
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 a blue phosphor of Eu ²⁺ and Mn ²⁺ co-activated aluminate in which plate-like particles were aggregated. Next, as the fluorescent lamp, the blue light emitting phosphor of Comparative Example 2 was used instead of the blue light emitting phosphor of Example 1, and the other conditions were the same as in Example 1 to produce a fluorescent lamp of Comparative Example 2.

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 Eu ²⁺ and Mn ²⁺ co-activated aluminate blue light emitting phosphor in which plate-like particles were aggregated. FIG. 4 is an 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 produce a fluorescent lamp of Comparative Example 3.

[Comparative Example 4] 246.75 g of γ-alumina (Al ₂ O ₃ ) (manufactured by Baikovsky, 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 components were sufficiently mixed, filled in an alumina crucible, covered, and fired in air at a firing temperature of 1450 ° C. for 2 hours to obtain a primary fired product. Obtained.

The above-mentioned first 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-mentioned raw materials are sufficiently mixed and placed in an alumina crucible. It was filled and fired at a firing temperature of 1550 ° C. for 2 hours in a nitrogen-containing hydrogen gas atmosphere to obtain a secondary fired product. This fired product was treated in the same manner as in Example 1 to obtain a phosphor of Comparative Example 4. This phosphor has a composition formula of Ba _0.4 Sr _0.5 Eu _0.1 Mg _0.99 Mn _0.01 Al ₁₀
It was a barium strontium magnesium aluminate blue-emitting phosphor co-activated with Eu ²⁺ and Mn ²⁺ aggregated plate-like particles at O ₁₇ . Next, as the fluorescent lamp, the blue light emitting phosphor of Comparative Example 4 was used instead of the blue light emitting phosphor of Example 1, and the other conditions were the same as in Example 1 to produce a fluorescent lamp of Comparative Example 4.

Comparative Example 5 γ alumina (Al ₂ O ₃ ) 246.75 g (manufactured by Baikowski Co., 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 mixed well, filled into an alumina crucible, covered, and fired at 1450 ° C. in air at 1450 ° C. It was fired for a time to obtain a primary fired product.

The above-mentioned primary fired product 292.99 g Europium oxide (Eu ₂ O ₃ ) 7.742 g Manganese dioxide (MnO ₂ ) 0.383 g The above-mentioned raw materials are sufficiently mixed and filled into an alumina crucible, and the mixture is placed in a nitrogen-containing hydrogen gas atmosphere. At a firing temperature of 1550 ° C. for 2 hours to obtain a secondary fired product. This fired product was treated in the same manner as in Example 1 to obtain a phosphor of Comparative Example 5. This phosphor has a composition formula of Ba _0.4 Sr _0.5 Eu _0.1 Mg _0.99 Mn _0.01 Al ₁₀
O ₁₇ was a plate-shaped Eu ²⁺ and Mn ²⁺ co-activated 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 produce a fluorescent lamp of Comparative Example 5.

(Average Particle Size of Phosphor) Table 1 shows Example 1
Raw materials, firing atmospheres, and average particle diameters of the phosphors of the phosphors of Comparative Examples 1 to 5 and Comparative Examples 1 to 5 were described. The approximate shape of the phosphor is a result of observation with a scanning electron microscope (SEM), and the average particle size was measured by an air permeation method using a Fischer particle sizer (Fisher subsieve sizer, manufactured by Fischer).

(Evaluation of Characteristics of Phosphor and Fluorescent Lamp) Each of the phosphors of Examples 1 to 7 and Comparative Examples 1 to 5 was 253.
The phosphor was excited by 7 nm ultraviolet light to emit light, and the luminous efficiency, luminescent color (chromaticity point according to the CIA color system) of each phosphor and the maintenance ratio of the luminous 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 luminous luminance of each phosphor by the y value of the chromaticity (luminance / y value).
And the relative percentage to the luminous efficiency (luminance / y value) of the aluminate phosphor produced by the conventional production method. The luminous efficiency maintenance rate after baking was determined for each phosphor at 650 ° C. in an air atmosphere.
The baking treatment was performed at a temperature of 15 minutes, and then the phosphors cooled to room temperature were excited with 253.7 nm ultraviolet light.
(y value).

The obtained Examples 1 to 7 and Comparative Example 1
Table 3 shows the luminous flux (initial luminous flux) immediately after lighting, the luminous flux maintenance factor, the change over time in the emission color, and the tube end color difference for the fluorescent lamps Nos. 5 to 5. In Table 3, the value of the initial luminous flux of the lamp was determined by measuring the luminous efficiency (luminance / y value) of each fluorescent lamp when it was first turned on after the lamp was manufactured, and using the aluminate phosphor obtained by the conventional manufacturing method in blue. This 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.
The luminous efficiency (luminance / y value) of the fluorescent lamp at the time of continuous lighting for 000 hours is a value expressed as a relative percentage to the luminous efficiency (luminance / y value) immediately after the lighting of each fluorescent lamp. The change with time of the emission color is the difference (Δx) between the emission chromaticity points x value (y) and the difference (y) between the y values when the respective fluorescent lamps are lit for the first time after manufacture and when they are continuously lit for 1000 hours.
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 represented by (x ₁ , y, respectively). 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, at least the Al particles in the phosphor material were first fired together with a flux, and then at least one selected from the group consisting of Ba, Sr and Ca, as can be seen from Table 1. The phosphors of Examples 1 to 7 in which the compound of one element and the remaining raw materials not mixed during the primary firing were subjected to the secondary firing were substantially spherical in appearance 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 efficiencies of the phosphor particles in Examples 1 to 7 are equal to or higher than those of Comparative Example 1 which is a conventional example, and the maintenance ratio of the luminous efficiency after baking is shown in Comparative Example 1. It can be seen that this is considerably improved with respect to ５5.

As can be seen from Table 3, the fluorescent lamps of Examples 1 to 7 in which the aluminate phosphor of the example was used as the blue light-emitting component phosphor of the three-wavelength fluorescent lamp were the comparative examples 1 to 7.
In each case, the initial luminous flux value was higher than that of the fluorescent lamp No. 5. Further, the luminous flux maintenance ratios 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. Changes showed small values. Further, the fluorescent lamps of Examples 1 to 7 have a tube end color difference of Comparative Example 1
5 could be significantly reduced as compared with the fluorescent lamps Nos.

[0055]

According to the present invention, the above configuration is adopted.
By performing a primary firing in which a phosphor material excluding compounds such as a, Sr, and Ca is mixed with a flux and firing, and a secondary firing in which the remaining phosphor material is fired in the absence of the flux, The present invention can provide an aluminate phosphor that has a rounded shape with little aggregation and a high luminous efficiency and a high luminous efficiency maintenance ratio after heat treatment. Further, when such a phosphor is applied as a blue phosphor of a three-wavelength band fluorescent lamp, the efficiency of the phosphor is high, the luminous efficiency is not decreased with time and the change of the luminescent color is small, and the luminescent color at both ends of the fluorescent lamp is low. It has become possible to provide a blue phosphor for a three-wavelength band fluorescent lamp with a small difference, high color rendering and high efficiency.

[Brief description of the drawings]

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

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

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

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

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[Procedure amendment]

[Submission date] June 20, 2001 (2001.6.2)
0)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction contents]

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The phosphor raw materials used in the present invention are as follows. As Al compounds, oxides and nitrates of Al,
Carbonates, may be used Al compounds that form oxides sulfate, the hydroxide compound soil heating. Among them,
Gamma alumina and aluminum hydroxide are suitable. Also,
Al compound specific surface area is preferably in the range of 10 to 200 m ² / g, more preferred range is 40 to 150 m ² / g. The Eu compound and Mn compound, an oxide of the element, and can be used nitrates, carbonates, sulfates, compounds which form oxides by oxalate soil heating.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction contents]

The Mg compound and the Zn compound include oxides of the above-mentioned elements, nitrates, carbonates, sulfates, and oxalic acids.
It may be used compounds which form oxides by salt soil heating. At least one selected from the group consisting of Ba, Sr and Ca
As the compound of the kind of element, an oxide of the element, and
Nitrates, carbonates, may be used compounds which form oxides by throat heating sulfates. As the flux, aluminum fluoride, boric acid, lithium fluoride, barium fluoride, or the like can be used.
Among them, aluminum fluoride is most suitable.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

The method for producing the aluminate phosphor of the present invention is performed according to the following procedure. The present invention always includes an Al compound,
A phosphor material excluding a compound of at least one element selected from the group consisting of Ba, Sr and Ca is mixed with a flux and fired to obtain a first fired material. Mix the remaining compounds of the raw materials and add additional flux to it
It is characterized in that secondary firing is performed without performing. This 2
The significance of the step firing is as follows.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction contents]

The base material of the phosphor according to the present invention is an alkaline earth metal aluminate (for example, BaMgAl ₁₀ O ₁₇ ) crystal, but since the stable shape of the crystal is plate-like, all the phosphor raw materials are used. When calcined in the presence of a flux, crystal growth is promoted and plate-like crystals are formed. On the other hand, when a fluorescent lamp is manufactured by applying a three-color mixed phosphor slurry into 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 ends of the fluorescent lamp Fluctuates, causing 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 desired that the phosphor should be substantially spherical, avoiding a plate-like or other irregular shape.

[Procedure amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

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

[Procedure amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction contents]

Example 3 In the manufacture of the aluminate phosphor of Example 1, the same as the phosphor of Example 1 except that the firing atmosphere during the first firing was changed to a reducing atmosphere of hydrogen-containing nitrogen gas. Thus, the phosphor of Example 3 was obtained. This phosphor composition formula _{Ba 0.4 Sr 0.5 Eu 0.1 Mg 0.99} Mn
_0.01 Al ₁₀ O ₁₇ , rounded Eu ²⁺ and Mn
^{It was a 2+} co-activated aluminate blue light emitting phosphor. next,
For 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 the other conditions were the same as in Example 1 to manufacture the fluorescent lamp of Example 3.

[Procedure amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0042

[Correction method] Change

[Correction contents]

The above-mentioned first 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-mentioned raw materials are sufficiently mixed and placed in an alumina crucible. Filled with hydrogen
By firing at a firing temperature of 1550 ° C. for 2 hours in a nitrogen- containing gas atmosphere, a secondary fired product was obtained. This fired product was treated in the same manner as in Example 1 to obtain a phosphor of Comparative Example 4. This phosphor has a composition formula of Ba _0.4 Sr _0.5 Eu _0.1 Mg _0.99 Mn _0.01 Al ₁₀
It was a barium strontium magnesium aluminate blue-emitting phosphor co-activated with Eu ²⁺ and Mn ²⁺ aggregated plate-like particles at O ₁₇ . Next, as the fluorescent lamp, the blue light emitting phosphor of Comparative Example 4 was used instead of the blue light emitting phosphor of Example 1, and the other conditions were the same as in Example 1 to produce a fluorescent lamp of Comparative Example 4.

[Procedure amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0044

[Correction method] Change

[Correction contents]

The above-mentioned first calcined product 292.99 g Europium oxide (Eu ₂ O ₃ ) 7.742 g Manganese dioxide (MnO ₂ ) 0.383 g The above-mentioned raw materials are mixed well, filled in an alumina crucible, and containing hydrogen.
By firing at a firing temperature of 1550 ° C. for 2 hours in a nitrogen- containing gas atmosphere, a secondary fired product was obtained. This fired product was treated in the same manner as in Example 1 to obtain a phosphor of Comparative Example 5. This phosphor has a composition formula of Ba _0.4 Sr _0.5 Eu _0.1 Mg _0.99 Mn _0.01 Al ₁₀
O ₁₇ was a plate-shaped Eu ²⁺ and Mn ²⁺ co-activated 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 produce a fluorescent lamp of Comparative Example 5.

[Procedure amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0049

[Correction method] Change

[Correction contents]

[0049]

[Table 1]

[Procedure amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0055

[Correction method] Change

[Correction contents]

[0055]

According to the present invention, the above configuration is adopted.
The primary firing, in which the phosphor raw material excluding compounds such as a, Sr, and Ca is mixed with a flux, and firing, and the remaining phosphor raw material are newly added.
By performing the secondary firing in which firing is performed without adding a flux to the alumina, 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 maintaining rate after heat treatment. Became. Further, when such a phosphor is applied as a blue phosphor of a three-wavelength band fluorescent lamp, the efficiency of the phosphor is high, the luminous efficiency is not decreased with time and the change of the luminescent color is small, and the luminescent color at both ends of the fluorescent lamp is low. It has become possible to provide a blue phosphor for a three-wavelength band fluorescent lamp with a small difference, high color rendering and high efficiency.

Claims (5)

[Claims] 1. A compound of at least one element selected from the group consisting 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 an aluminate phosphor by sintering a compound or a mixture of an Eu compound and a Mn compound as a phosphor raw material, and baking these, first, the phosphor raw material contains at least the Al compound, and Ba, Sr described above
And a mixture of a phosphor material excluding a compound of an element selected from the group of Ca and a flux, followed by firing to obtain a primary fired product,
A method for producing an aluminate phosphor, comprising mixing the remaining compound of the phosphor raw material with the primary fired product and secondary firing. 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 first fired material. 3. A phosphor raw material comprising said Al compound, said Eu compound or a mixture of Eu compound and Mn compound, and / or said Mg compound or a mixture of Mg compound and Zn compound, and said flux. 2. A method for producing an aluminate phosphor according to claim 1, wherein the mixture is mixed and fired to obtain a first fired material. 4. The method according to claim 1, wherein the flux is aluminum fluoride, boric acid,
2. The method according to claim 1, wherein the at least one member is selected from the group consisting of lithium fluoride and barium fluoride.
The method for producing an aluminate phosphor according to any one of claims 1 to 3. 5. The method for producing an aluminate phosphor according to claim 1, wherein the Al compound is gamma alumina or aluminum hydroxide.