JPH11106748A - Preparation of tetradecahedral type rare earth-activated alkaline earth metal halogenated fluoride phosphor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for preparing a tetradecahedral type accelerated phosphor having improved properties in stimulated emission, erasing properties, afterimage properties, fading properties, X-ray afterglow, etc. SOLUTION: A process for preparing a tetradecahedral type rare earth- accelerated alkaline earth metal halogenated fluoride phosphor of the formula Ba1-x Cax FBr1-y Iy :aEu, bM, eA (wherein M is Li, Na, K, Rb or Cs; A is an oxide such as Al2 O3 and SiO2 ; 0<x<=0.03, 0<y<=0.03, 0.0001<=a<=0.01, 0<b<=0.05 and 0<e<=0.05) comprises (a) a step of preparing a barium bromine fluoride phosphor precursor, (b) a step of forming a barium iodine fluoride phosphor precursor, (c) a step of mixing said phosphor precursors with an oxide A for preventing calcining, optionally, a halide M, (d) a step of calcining, (e) a step of unfastening, classifying and decanting and (f) a step of solid-liquid separation and drying.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a stimulable phosphor based on a tetrahedral rare earth-activated alkaline earth metal fluorinated halide.

[0002]

2. Description of the Related Art A radiation image recording / reproducing method using a stimulable phosphor is known as an alternative to the conventional radiographic method. This method uses a radiation image conversion panel (a stimulable phosphor sheet) containing a stimulable phosphor, and transmits radiation transmitted through a subject or emitted from a subject to the stimulable phosphor of the panel. By absorbing the stimulable phosphor with electromagnetic waves (excitation light) such as visible light and infrared light in a time series manner, the radiation energy stored in the stimulable phosphor is absorbed by the body. The fluorescent light is emitted (stimulated emission light), the fluorescent light is read photoelectrically to obtain an electric signal, and a radiation image of a subject or a subject is reproduced as a visible image based on the obtained electric signal. . After the reading of the panel is completed, after the remaining image is deleted, the panel is prepared for the next photographing.
That is, the radiation image conversion panel can be used repeatedly.

According to the above-described radiographic image recording / reproducing method, a radiation having a much smaller amount of exposure and a richer amount of information than a conventional radiographic method using a combination of a radiographic film and an intensifying screen. There is an advantage that an image can be obtained. Furthermore, while the conventional radiographic method consumes radiographic film for each shot, the radiographic image recording / reproducing method uses a radiographic image conversion panel repeatedly, which leads to resource conservation and economic efficiency. Is also advantageous.

A stimulable phosphor is a phosphor that emits stimulable light when irradiated with radiation and then with excitation light. However, in practice, the stimulable phosphor has a wavelength of 400 to 900 nm due to the excitation light. Phosphors that exhibit stimulated emission in the 500 nm wavelength range are commonly used. Examples of the stimulable phosphor conventionally used in the radiation image conversion panel include a rare earth activated alkaline earth metal halide-based phosphor.

The radiation image conversion panel used in the radiation image recording / reproducing method has, as a basic structure, a support and a stimulable phosphor layer provided on the surface of the support. However, when the phosphor layer is self-supporting, a support is not necessarily required. The stimulable phosphor layer usually comprises a stimulable phosphor and a binder containing and supporting the stimulable phosphor in a dispersed state. However, there is also known a stimulable phosphor layer which does not include a binder formed by a vapor deposition method or a sintering method and is composed of only an aggregate of the stimulable phosphor. Also,
There is also known a radiation image conversion panel having a stimulable phosphor layer in which a polymer substance is impregnated in a gap between stimulable phosphor aggregates. In any of these phosphor layers, the stimulable phosphor has a property of exhibiting stimulable emission when irradiated with excitation light after absorbing radiation such as X-rays. The radiation emitted from the specimen
The radiation image is absorbed by the stimulable phosphor layer of the radiation image conversion panel in proportion to the radiation dose, and a radiation image of the subject or the subject is formed on the panel as a radiation energy accumulation image. This accumulated image can be emitted as stimulated emission light by irradiating the excitation light, and the accumulated image of radiation energy is imaged by photoelectrically reading the stimulated emission light and converting it into an electric signal. It is possible to do.

The rare earth-activated alkaline earth metal halide-based stimulable phosphor has excellent sensitivity and, when used as a radiation image conversion panel, provides a radiation-reproduced image with high sharpness. It can be called an excellent stimulable phosphor. However, as radiation image recording / reproducing methods have been put to practical use, demands for stimulable phosphors having higher characteristics have been increasing.

[0007] Japanese Patent Application Laid-Open No. 7-233369 discloses the problem that the conventionally used rare earth activated alkaline earth metal fluorinated halide stimulable phosphor is composed of plate-like particles. As a solution to the problem, a rare-earth activated alkaline earth metal fluorinated halide stimulable phosphor having a specific basic composition formula and having a tetrahedral shape and a method for producing the same, It has been proposed to use a luminescent phosphor for a radiation image conversion panel.

[0008]

SUMMARY OF THE INVENTION The present invention, when used in a radiation image recording / reproducing method, has practical characteristics such as stimulated emission, erasing characteristics, afterimage characteristics, fading characteristics, and X-ray persistence. The present invention provides a novel method for producing a tetrahedral rare earth activated alkaline earth metal fluorohalide-based stimulable phosphor having a specific composition, which is more excellent.

[0009]

SUMMARY OF THE INVENTION The present invention, formula _{(I): Ba 1-x} Ca x FBr 1-y I y: aEu, bM, eA ... (I) [ however, M is Li, Na, A represents at least one alkali metal selected from the group consisting of K, Rb and Cs; A represents an oxide such as Al ₂ O ₃ or SiO ₂ ;
x, y, a, b and e are respectively 0 <x ≦ 0.03,
0 <y ≦ 0.30, 0.0001 ≦ a ≦ 0.01, 0 <
It is a numerical value satisfying the conditions of b ≦ 0.05 and 0 <e ≦ 0.05. A method comprising the combination of the following steps for producing a tetrahedral rare earth activated alkaline earth metal fluorohalide-based phosphor represented by the formula: a) Eu halide and Ca halogen in an aqueous solution of BaBr ₂ And optionally MX (X is a halogen,
At least one amount of) the addition of selected from the group consisting of NO _3, NO ₂ and carboxylic acid residues, BaBr ₂
Concentration is 0.9 to 1.6 mol / L, temperature is 20 to 100 ° C
Preparing a rare earth-activated barium fluorobromide-based phosphor precursor by adding an inorganic fluoride to the solution at a constant rate; and b) adding a Eu halide to an aqueous solution of BaI _2. When added, the BaI ₂ concentration is 2.9 to 4.2 mol / L and the temperature is 20 to
Preparing a solution at 100 ° C. and then adding inorganic fluoride at a constant rate to the solution to obtain a rare earth activated barium fluoroiodide-based phosphor precursor; c) the rare earth obtained in step a) Activated barium fluorobromide-based phosphor precursor, rare-earth activated barium fluoroiodide-based phosphor precursor obtained in step b), oxide comprising A for preventing sintering, and if necessary M halide, Ba
Mixing F ₂ and / or BaBr ₂ ; d) baking the mixture obtained in step c) in a trace oxygen-containing nitrogen gas atmosphere at a temperature of 700 to 900 ° C. for 1 to 6 hours; e. ) The slurry obtained by dispersing the calcined product obtained in the step d) in a lower alcohol or an aqueous solution containing Ba ²⁺ to reduce sintering and agglomeration due to calcining, and then removing particles having a certain particle size or more by wet classification. And then leaving the slurry to stand for a certain period of time, removing the supernatant to obtain a slurry from which excess oxide A has been removed; f) performing solid-liquid separation on the slurry obtained in step e) After that, a step of drying and then performing a dry classification; the above-described coefficients such as x, y, a, b, and e in the phosphor composition described in the present specification are obtained by analyzing the obtained phosphor. It is the numerical value obtained. Since the composition changes before and after the firing step in the manufacture of the phosphor, the ratio of each component of each raw material used in the manufacture of the phosphor and the ratio of each component of the completed phosphor are slightly different.

In the above composition formula (I), considering the amount of stimulable luminescence to be obtained and the erasing / afterimage characteristics, x,
y, a, b and e are each 0.001 ≦ x ≦ 0.0
3, 0.10 ≦ y ≦ 0.20, 0.001 ≦ a ≦ 0.0
1, ⁵ × 10 ⁻⁵ ≦ b ≦ 0.005 and 0.001 ≦ e
It is preferable that the value be in the range of ≦ 0.03.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing a tetrahedral rare earth activated alkaline earth metal fluorohalide phosphor of the present invention will be described in detail below.

A) First, a halide of Eu and a halide of Ca are added to an aqueous solution of BaBr ₂ . Further, a compound of an alkali metal M (a halide, a nitrite, a nitrate, an acetate, or the like) is added as needed. The alkali metal compound need not always be added here, and may be added at the time of mixing the phosphor precursor crystal and the oxide in step c). The alkali metal M is preferably K, Cs and Li. At this time, if desired, a small amount of acid, ammonia, alcohol, water-soluble polymer, insoluble metal oxide fine powder, or the like may be further added. This solution (reaction mother liquor) contains 2
It is maintained at a temperature of 0-100 ° C. The concentration of BaBr _{2 in} this solution before the start of the reaction is preferably 0.9 to 0.9%.
It is 1.6 mol / L, especially about 1.0 mol / L. Next, 20 to 100 ° C, preferably 40 to 80 ° C,
In particular, while stirring this solution (reaction mother liquor) maintained at about 60 ° C., an inorganic fluoride (an aqueous solution of ammonium fluoride,
Barium fluoride slurry) is injected at a constant rate using a pipe with a pump or the like. This injection is preferably carried out in the region where the stirring is particularly violent. By injection of the inorganic fluoride into the reaction mother liquor, 14
A facet type rare earth activated barium fluorobromide-based phosphor precursor crystal (hereinafter, referred to as a BFB crystal) precipitates. Next, the BFB crystals are separated from the solvent by filtration, centrifugation, or the like, sufficiently washed with methanol or the like, and dried.

B) Eu halide is added to the aqueous solution of BaI ₂ . At this time, a small amount of acid, ammonia, alcohol, water-soluble polymer, insoluble metal oxide fine particles, or the like may be further added as needed. This solution (reaction mother liquor) is maintained at a temperature of 20-100 ° C.
Further, BaI ₂ concentration in the solution before initiation of the reaction is preferably 2.9 to 4.2 mol / L, especially about 3.8 mol / L. Next, while stirring this solution (reaction mother liquor) maintained at 20 to 100 ° C., preferably 40 to 80 ° C., especially around 60 ° C., an inorganic fluoride (aqueous solution of hydrogen fluoride, a slurry of barium fluoride, etc.) ) Is injected at a constant rate using a pipe with a pump. This injection is preferably carried out in the region where the stirring is particularly violent. By injecting the inorganic fluoride into the reaction mother liquor, a tetrahedral rare earth activated barium fluoroiodide-based phosphor precursor crystal (hereinafter, referred to as a BFI crystal) precipitates. Next, the BFI crystals are separated from the solvent by filtration, centrifugation or the like, sufficiently washed with isopropanol or the like, and dried.

C) Fine particles of oxide A (Al ₂ O ₃ , SiO _2, etc.) are added to the BFB crystal and the BFI crystal.
And, if necessary, a halide of an alkali metal M, B
Mix aF ₂ and / or BaBr ₂ thoroughly with stirring. The oxide A is added for the purpose of preventing a change in particle shape due to sintering of the phosphor precursor crystal and a change in particle size distribution due to fusion between particles during firing in the next step d). . By this mixing, the fine particles of oxide A uniformly adhere to the crystal surface. The oxide A is preferably Al ₂ O ₃ , and its addition amount is suitably from 0.1 to 1.0% by weight of the phosphor precursor crystal.

D) The above mixture is filled in a heat-resistant container such as a quartz boat, an alumina crucible, a quartz crucible, etc., and placed in a furnace core of an electric furnace for firing. Firing temperature is 700-90
A range of 0 ° C. is appropriate, and a range of 750 to 900 ° C. is particularly preferable. As the firing atmosphere, a nitrogen gas atmosphere containing a small amount of oxygen gas is used. The firing time varies depending on the filling amount of the mixture, the firing temperature, the temperature at which the mixture is taken out of the furnace, and the like.
Particularly, 2 to 6 hours are preferable.

For example, first, the mixture is placed in an electric furnace at 750 to
Bake at a constant temperature in the range of 900 ° C. for 2 to 6 hours. During this time, the inside of the furnace is evacuated at least once, and then replaced with a nitrogen gas atmosphere containing a small amount of oxygen gas. Next, the temperature in the furnace is lowered to a temperature of 750 ° C. or less over 30 minutes or more, and then replaced with a nitrogen gas atmosphere containing a trace amount of oxygen gas again. Next, keep the inside of the furnace out of
After cooling to a temperature of 50 ° C. or lower, the fired product is taken out to the atmosphere.

The total weight of the phosphor precursor crystals m
(Kg) and the furnace volume l (L) of the electric furnace are m /
It is preferable that l ≧ 0.05 (kg / L).

E) The above fired product is dispersed in a lower alcohol such as methanol or an aqueous solution containing Ba ²⁺ , and then subjected to a loosening treatment using a roll mill or the like, thereby alleviating sintering and aggregation due to firing. I do. Next, the slurry of the fired product is subjected to wet classification using a vibration sieve or the like to obtain a slurry from which coarse particles having a certain particle size or more have been removed. Next, the slurry is allowed to stand for a certain period of time (for example,
After leaving still for 10 hours, the supernatant is removed to carry out decanting, thereby obtaining a slurry from which the excess of the oxide A has been removed. In this step, the aqueous solution containing Ba ²⁺ is preferably prepared by dissolving a phosphor substantially conforming to the composition formula (I) in water.

F) The solid slurry is subjected to solid-liquid separation by filtration under reduced pressure or filtration under pressure, washed with methanol or the like, and dried. Further, the fired product is subjected to dry classification using a vibration sieve or the like.

In this way, the desired tetrahedral rare earth activated alkaline earth metal fluorinated halide stimulable phosphor is obtained.

[0021]

【Example】

[Example 1] Ba _0.993 Ca _0.007 FBr _0.85 I _0.15 :
0.004Eu, 0.0006K, 0.00002 Cs, 0.01Al 2
Production of O ₃ a) 1200 mL of an aqueous solution of BaBr ₂ (2.5 mol / L)
Into a reactor having a volume of 4000 mL, into which EuBr
₃ aqueous solution (0.2 mol / L) 37.5 mL, KBr3
0.9 g, 3.54 g of CaBr ₂ .2H ₂ O, and 1762.5 mL of water were added. The reaction mother liquor (BaBr ₂ concentration: 1.00 mol / L) in this reactor was kept at 60 ° C., and a screw stirring blade having a diameter of 60 mm was rotated at 500 rpm.
and the reaction mother liquor was stirred. 300 mL of an NH ₄ F aqueous solution (5 mol / L) was injected into the above-described reaction mother liquor kept under stirring at a liquid sending rate of 5.0 mL / min using a roller pump to generate a precipitate. After completion of the injection, the precipitate was ripened by continuing the warming and stirring for 2 hours.
Next, the precipitate was separated by filtration and washed with 2 L of methanol. Next, the washed precipitate was taken out and vacuum dried at 120 ° C. for 4 hours to obtain about 350 g of a europium-activated barium fluorobromide-based phosphor precursor crystal (BFB crystal). Observation of the obtained crystal with a scanning electron microscope revealed that most of the crystal was a tetrahedral crystal. Next, this crystal was used as a light diffraction type particle size distribution measuring device (manufactured by Horiba, Ltd .: LA).
-500), the average crystal size was 5.0.
μm was confirmed.

B) BaI ₂ aqueous solution (4.0 mol / L) 2
Put 850mL reactor volume 4000 mL, this was added EuI ₃ aqueous solution (0.2 mol / L) 90 mL and water 60 mL. The reaction mother liquor (BaI) in this reactor
₂ concentration: 3.80 mol / L) at 60 ° C.
The reaction mother liquor was stirred by rotating a 0 mm screw type stirring blade at 500 rpm. HF aqueous solution (5 mol / L)
720 mL was injected into the above-mentioned reaction mother liquor kept under stirring at a liquid sending rate of 12 mL / min using a roller pump to generate a precipitate. After completion of the injection, the keeping and stirring were continued for 2 hours to ripen the precipitate. Next, the precipitate was separated by filtration and washed with 2 L of isopropanol. Next, the washed precipitate was taken out and vacuum-dried at 120 ° C. for 4 hours to obtain about 1000 g of a europium-activated barium fluoroiodide phosphor precursor crystal (BFI crystal). Observation of the obtained crystals with a scanning electron microscope revealed that most of them were 14
It was a faceted crystal. Next, when the crystals were measured by a light diffraction type particle size distribution analyzer, it was confirmed that the average crystal size was 6.5 μm.

C) 165 g of the above BFB crystal and B
35 g of FI crystal was taken, 0.10 g of CsBr was added thereto, and alumina (Al ₂ O) was used to prevent sintering during firing.
₃ ) Ultrafine particle powder (1.0 g, 0.5% by weight) was added, and the mixture was sufficiently stirred and mixed with a double cone mixer to uniformly adhere the ultrafine alumina powder to the crystal surface.

D) filling the above mixture into a quartz boat,
Using a tube furnace, baking was performed at 820 ° C. for 3 hours in a nitrogen gas atmosphere. Oxygen gas was introduced at a rate of 0.6% during the firing to form a nitrogen gas atmosphere containing a trace amount of oxygen gas. Next, after the temperature in the furnace was lowered to 700 ° C. over one and a half hours, the furnace was evacuated and replaced with a nitrogen gas atmosphere containing a small amount of oxygen gas. Next, the inside of the furnace was cooled to 350 ° C. or less without being exposed to the atmosphere, and then the fired product was taken out to the atmosphere.

E) After dispersing 1000 g of the above calcined product in 1.5 L of methanol, a roll mill (rotation speed: 5
(0 rpm) for 15 hours. Next, the slurry of the fired product was passed through a vibration sieve (nylon mesh; # 508) to perform wet classification. Next, the slurry was allowed to stand for 10 hours, and then the supernatant was removed to obtain a slurry from which excess alumina was removed.

F) The calcined product slurry was filtered under reduced pressure to perform solid-liquid separation, washed with methanol, and vacuum dried at 150 ° C. for 10 hours. Next, the fired product was again passed through a vibration sieve (nylon mesh; # 460) to perform dry classification. In this way, europium-activated barium fluorobromide-based phosphor particles represented by the composition formula described above were obtained. Observation of the obtained phosphor particles with a scanning electron microscope revealed that most of the particles were in the shape of a tetrahedron, like the raw material crystal. The average crystal size of the crystals measured by an optical diffraction type particle size distribution analyzer was 7.0 μm.

[Evaluation of phosphor] Regarding the above phosphor,
Various characteristics were evaluated by the following methods. [Stimulated luminescence] After irradiating the phosphor with X-rays of 80 kVp and 100 mR, He-Ne laser light was applied at 12.4 J / m ^2.
And the luminescence (PSL) of stimulated emission emitted from the phosphor was measured.

[Erase Characteristics (Erase Value)] 80 kV
After irradiating X-rays of p, 100 mR, He-Ne laser light is irradiated at 12.4 J / m ² , and the luminescence (PSL) of photostimulated luminescence emitted from the phosphor is measured and the initial value is obtained. And Next, a white fluorescent light was applied to this phosphor at 400,000 lx · s.
After performing an erasing operation by irradiating under the conditions described above, He-Ne laser light was applied at 12.4 J / m ² , and the amount of stimulated emission of the phosphor was measured to obtain an erasing level value. The ratio of the erase level value to the initial value (erase level value / initial value) was defined as the erase value.

[Afterimage Characteristics (Afterimage Value)] After the erase level value was measured by the above method, the phosphor was allowed to stand at 60 ° C. for 24 hours, and then irradiated with a He—Ne laser beam at 12.4 J / m ^2. The amount of stimulated emission of the phosphor was measured to obtain an afterimage level value. The ratio of the afterimage level value to the initial value (afterimage level value / initial value) was defined as the afterimage value.

[Fading Characteristics (Fading Value)] After measuring the stimulating light emission amount (initial value) of the phosphor by the above-mentioned method, the phosphor was left at 32 ° C. for 1 hour, and then He-Ne.
Laser light was applied at 12.4 J / m ² , and the amount of stimulated emission of the phosphor was measured to obtain a fading level value. The ratio of the fading level value to the initial value (fading level value / initial value) × 100 was defined as the fading value.

[X-ray persistence (X-ray persistence value)]
After irradiating with X-rays of 0 kVp and 100 mR, it was left as it was for 46 seconds, and then the amount of afterglow emitted from the phosphor was measured to obtain the afterglow level value. The ratio of the afterglow level value to the initial value was represented by a common logarithm (log ₁₀ (afterglow level value / initial value)), which was taken as the X-ray afterglow value.

[Experimental Results] The tetrahedral europium-activated barium fluorobromide-based phosphor produced by the method of the present invention has a large stimulating luminescence, a low erase value and a low afterimage value, and a low fading value. High and low X-ray persistence.

[0033]

The tetrahedral rare earth activated alkaline earth metal fluorinated halide phosphor prepared according to the method of the present invention has photostimulable emission, erasing, afterimage, fading, and X-ray emission properties. It shows excellent improved properties in persistence.

Claims (14)

[Claims] 1. A composition formula _{(I): Ba 1-x} Ca x FBr 1-y I y: aEu, bM, eA ... (I) [ however, M is a group consisting of Li, Na, K, Rb and Cs A represents an oxide selected from the group consisting of Al ₂ O ₃ and SiO ₂ ; x, y, a, b and e each represent 0 <x ≦ 0. 03, 0 <y ≦ 0.30, 0.000
1 ≦ a ≦ 0.01, 0 <b ≦ 0.05, and 0 <e ≦
It is a numerical value satisfying the condition of 0.05. A method comprising the combination of the following steps for producing a tetrahedral rare earth activated alkaline earth metal fluorohalide-based phosphor represented by the formula: a) Eu halide and Ca halogen in an aqueous solution of BaBr ₂ And optionally MX (X is a halogen,
At least one amount of) the addition of selected from the group consisting of NO _3, NO ₂ and carboxylic acid residues, BaBr ₂
Concentration is 0.9 to 1.6 mol / L, temperature is 20 to 100 ° C
Preparing a rare earth-activated barium fluorobromide-based phosphor precursor by adding an inorganic fluoride to the solution at a constant rate; and b) adding a Eu halide to an aqueous solution of BaI _2. When added, the BaI ₂ concentration is 2.9 to 4.2 mol / L and the temperature is 20 to
Preparing a solution at 100 ° C. and then adding inorganic fluoride at a constant rate to the solution to obtain a rare earth activated barium fluoroiodide-based phosphor precursor; c) the rare earth obtained in step a) Activated barium fluorobromide-based phosphor precursor, rare-earth activated barium fluoroiodide-based phosphor precursor obtained in step b), oxide comprising A for preventing sintering, and if necessary M halide, Ba
Mixing F ₂ and / or BaBr ₂ ; d) baking the mixture obtained in step c) in a trace oxygen-containing nitrogen gas atmosphere at a temperature of 700 to 900 ° C. for 1 to 6 hours; e. ) The slurry obtained by dispersing the calcined product obtained in the step d) in a lower alcohol or an aqueous solution containing Ba ²⁺ to reduce sintering and agglomeration due to calcining, and then removing particles having a certain particle size or more by wet classification. And then leaving the slurry to stand for a certain period of time, removing the supernatant to obtain a slurry from which excess oxide A has been removed; f) performing solid-liquid separation on the slurry obtained in step e) Thereafter, a step of drying and then performing dry classification. 2. The method of claim 1, wherein in step a), the inorganic fluoride is an ammonium fluoride solution or a slurry of BaF _2. Method. 3. The tetrahedral rare earth activated alkaline earth metal fluoride halide-based phosphor according to claim 1, wherein in step b), the inorganic fluoride is a hydrogen fluoride solution or a slurry of BaF _2. Manufacturing method. 4. The method according to claim 1, wherein the mixture is heated to 750-900 ° C.
Baking at a constant temperature in the range of 2 to 6 hours in a baking furnace, during which the inside of the furnace is evacuated at least once and then replaced with a nitrogen gas atmosphere containing a trace amount of oxygen.
A step of reducing the temperature to 750 ° C. or lower over a period of at least one minute and then replacing the atmosphere with a nitrogen gas atmosphere containing a small amount of oxygen again, and cooling the temperature to 350 ° C. or lower without touching the air, and then taking out the fired product into the air 4. The method according to claim 1, which comprises the steps of:
The method for producing a tetrahedral rare earth activated alkaline earth metal fluorohalide-based phosphor according to any one of the above items. 5. In step d), the ratio of the total weight m (kg) of the phosphor precursor used for firing to the inner volume l (L) of the furnace used for firing is m / l ≧ 0.05 ( kg /
The method for producing a tetrahedral rare earth activated alkaline earth metal fluorinated halide-based phosphor according to any one of claims 1 to 4, which is L). 6. The method according to claim 1, wherein in step e), the aqueous solution containing Ba ²⁺ is prepared by dissolving a phosphor substantially conforming to the composition formula (I) in water. 13. The method for producing a tetrahedral rare earth activated alkaline earth metal fluorohalide-based phosphor according to item 8. 7. The tetrahedral rare earth activated alkaline earth metal fluorinated halide according to claim 1, wherein the solid-liquid separation method in step f) is pressure filtration. A method for producing a phosphor. 8. The formula _{(II): Ba 1-x} Ca x FBr 1-y I y: aEu, bK, cCs, dLi, eAl 2 O 3 ... (II) [ However, x, y, a, b , C, d and e are respectively 0 <x ≦ 0.03, 0 <y ≦ 0.30, 0.000
1 ≦ a ≦ 0.01, 0 <b ≦ 0.001, 0 ≦ c ≦ 0.
001, 0 ≦ d ≦ 0.001, and 0 <e ≦ 0.05
Is a numerical value that satisfies the condition of The method comprises the following combination of steps for fabricating the tetradecahedral rare earth activated alkaline earth metal fluoride halide phosphors represented by]: a) an aqueous solution of BaBr ₂ EuBr _3, the CaBr ₂ and need MBr (M is K, Cs and / or Li)
It was added, BaBr ₂ concentration 0.9 to 1.6 mol /
L, preparing a solution having a temperature of 20 to 100 ° C., and then adding an inorganic fluoride to the solution at a constant rate to obtain a rare earth-activated barium fluorobromide-based phosphor precursor; b) BaI ₂ EuI ₃ was added to the aqueous solution of the above to prepare a solution having a BaI ₂ concentration of 2.9 to 4.2 mol / L and a temperature of 20 to 100 ° C. Then, an inorganic fluoride was added to this solution at a constant rate. Obtaining a rare earth-activated barium fluoroiodide-based phosphor precursor by heating; c) the rare earth-activated barium fluorobromide-based phosphor precursor obtained in step a); the rare earth-activated barium fluorobromide-based phosphor precursor obtained in step b) Active barium fluoroiodide-based phosphor precursor, Al ₂ for preventing sintering
O ₃ and, if necessary, MBr (M is K, Cs and / or
Or Li), mixing BaF ₂ and / or BaBr ₂ ; d) calcining the mixture obtained in step c) in a trace oxygen-containing nitrogen gas atmosphere at a temperature of 700 to 900 ° C. for 1 to 6 hours. E) dispersing the calcined product obtained in the step d) in a lower alcohol or an aqueous solution containing Ba ²⁺ to alleviate sintering and agglomeration due to the calcining; After obtaining the removed slurry, and then allowing the slurry to stand for a certain period of time, the supernatant was removed to remove excess Al ₂
F) a step of obtaining a slurry from which O ₃ has been removed; f) a step of performing solid-liquid separation on the slurry obtained in step e), followed by drying and then dry classification. 9. The method of claim 8, wherein in step a), the inorganic fluoride is an ammonium fluoride solution or a slurry of BaF _2. Method. 10. The tetrahedral rare earth activated alkaline earth metal fluoride halide phosphor according to claim 8, wherein in step b), the inorganic fluoride is a hydrogen fluoride solution or a slurry of BaF _2. Manufacturing method. 11. The step d) comprises mixing the mixture with 750-900
Baking in a baking furnace at a constant temperature in the range of 2 ° C. for 2 to 6 hours, during which the furnace is evacuated at least once and then replaced with a nitrogen gas atmosphere containing a trace amount of oxygen.
A step of lowering the temperature to 750 ° C. or lower over 0 minutes or more and then replacing the atmosphere with a nitrogen gas atmosphere containing a small amount of oxygen again, and cooling the fired product to 350 ° C. or lower without contacting the air, The method for producing a tetrahedral rare earth-activated alkaline earth metal fluorohalide-based phosphor according to any one of claims 8 to 10, comprising a removing step. 12. In step d), the ratio of the total weight m (kg) of the phosphor precursor used for firing to the inner volume l (L) of the furnace used for firing is m / l ≧ 0.05 ( kg
/ L), the method for producing a tetrahedral rare earth activated alkaline earth metal fluorohalide-based phosphor according to any one of claims 8 to 11. 13. The method according to claim 8, wherein in step e), the aqueous solution containing Ba ²⁺ is prepared by dissolving a phosphor substantially according to the composition formula (I) in water. 13. The method for producing a tetrahedral rare earth activated alkaline earth metal fluorohalide-based phosphor according to item 8. 14. The tetrahedral rare earth activated alkaline earth metal fluorohalide system according to claim 8, wherein the solid-liquid separation method in step f) is pressure filtration. A method for producing a phosphor.