JPH0412910B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a phosphor and a method for manufacturing the same.
More specifically, the present invention relates to a rare earth element-activated divalent metal fluorohalide phosphor and a method for producing the same. Conventionally, as a type of fluorohalide-based phosphor, there is a rare earth element-activated divalent metal fluorohalide phosphor that uses a fluorohalide compound of a divalent metal, which is mainly an alkaline earth metal, as a host and uses a rare earth element as an activator. Are known. For example, Tokko Akira
51-28591, the compositional formula is (Ba _1-xy , Sr _x , Ca _y , Eu ²⁺ _p ) F(Cl _1-ab , _Bra , I _b ) (However, x, y, p, a and b are x+y+p≦
1, y≦0.20, 0.001≦p≦0.20 and a+b≦1
A divalent europium-activated divalent metal fluorohalide phosphor represented by the following is disclosed. When this phosphor is excited by X-rays, ultraviolet rays, electron beams, etc.
It exhibits near-ultraviolet light emission with a peak in the emission spectrum distribution at 390 nm. In particular, this phosphor has high absorption efficiency for X-rays, and the above-mentioned near-ultraviolet emission is
Since it matches the spectral sensitivity of ray film, it is used as a phosphor for X-ray intensifying screens. The rare earth element-activated divalent metal fluorohalide phosphor disclosed in the above-mentioned Japanese Patent Publication No. 51-28591 can be obtained by firing the phosphor raw material at a temperature of 600 to 1000°C for an appropriate period of time. However, this phosphor has the property of being easily sintered during the firing process. Therefore, in the production of this phosphor, it is generally necessary to perform a crushing operation and an accompanying classification operation after firing, which not only complicates the production process but also significantly lowers the yield of the phosphor. Furthermore, it is a common belief in the field of phosphor technology that the sintering phenomenon only has a negative effect on the luminescent properties of the phosphor, especially the luminous efficiency. It is thought that the sintering phenomenon during the firing process has an adverse effect on the luminous efficiency of this phosphor. As stated in U.S. Patent No. 4,080,306,
The above sintering phenomenon is caused by the presence of KCl, NaCl, etc. in the phosphor raw materials.
This can be alleviated by adding a fluxing agent such as LiCl, BaCl ₂ or MgCl ₂ , but if a solvent is used, a washing process must be performed to remove the flux after the firing process. Although the crushing process and the accompanying classification process are no longer necessary, this new water washing process is required in its place.Therefore, although the method of using a flux can shorten the processing time to some extent, it simplifies the manufacturing process. It's hard to call it a thing. Furthermore, since rare earth element-activated divalent metal fluorohalide phosphors have a relatively high solubility in water, the phosphor also flows out along with the flux during the water washing process, which causes the phosphor to deteriorate. The yield decreases, and from this point of view as well, use of a flux is not preferred. Furthermore, rare earth element-activated divalent metal fluorohalide phosphors are hygroscopic, and therefore have the disadvantage of poor fluidity as a powder and a tendency to agglomerate. Therefore, when putting this phosphor into practical use, it often occurs that handling thereof is difficult due to aggregation. Furthermore, the afterglow properties of rare earth element-activated divalent metal fluorohalide phosphors are not necessarily satisfactory. For example, U.S. Pat. No. 3,951,848 states:
A phosphor in which metal oxides of aluminum, lead, and thallium are added to the divalent europium-activated barium fluorochloride phosphor raw material has been described in order to improve luminance. is relatively slow and cannot be said to be fully satisfactory in terms of afterglow characteristics. As mentioned earlier, rare earth element-activated divalent metal fluorohalide phosphors are being used or are being used in large quantities in X-ray intensifying screens, storage type radiation image converters, etc. The above-mentioned drawbacks are serious problems in terms of both cost and phosphor properties. Furthermore, there is a strong need for a phosphor that has good afterglow properties, which solves all of the conventional problems. The present invention was made under the above-mentioned circumstances, and does not cause sintering during the firing process, and therefore does not require a crushing process after firing and a classification process associated with it, and is thus economically and economically efficient. The object of the present invention is to provide a rare earth element-activated divalent metal fluorohalide phosphor that can be obtained in high yield and a method for producing the same. Another object of the present invention is to provide a rare earth element-activated divalent metal fluorohalide phosphor with improved luminance and a method for producing the same. A further object of the present invention is to provide a rare earth element-activated divalent metal fluorohalide phosphor having good powder fluidity and a method for producing the same. A further object of the present invention is to provide a rare earth element-activated divalent metal fluorohalide phosphor with good afterglow properties and a method for producing the same. In order to achieve the above object, the present inventors have developed a divalent europium-activated divalent metal fluorohalide phosphor disclosed in the above-mentioned Japanese Patent Publication No. 51-28591, and a composition formula of which is M〓FX・xA: yLn (where M〓 is at least one of Ba, Ca, and Sr, Ln is at least one of Eu and Sm, X is at least one of Br and I, and y is 0<y≦ We have conducted various studies on rare earth element-activated divalent metal fluorohalide phosphors expressed as 0.2. As a result, in manufacturing these rare earth element-activated divalent metal fluorohalide phosphors, specific compounds are added and mixed to the phosphor raw materials and fired, and the phosphors contain specific metal oxides. In this case, sintering does not occur during the firing process, and therefore there is no need for pulverization and accompanying classification after firing, which makes it possible to produce the phosphor with a high yield, and the resulting phosphor The present inventors have discovered that the powder exhibits higher luminance than conventional products, and has better powder fluidity and afterglow properties, leading to the completion of the present invention. The rare earth element-activated divalent metal fluorohalide phosphor of the present invention has a composition formula of M〓FX・xA:yLn (where M〓 is at least one of Ba and Sr).
species, A is Al ₂ O ₃ , Ln is at least one of Eu and Sm, X is at least one of Br and I, and x and y are each 5×10 ^-5 ≦
It is a number that satisfies the conditions x≦0.5 and 0<y≦0.2). However, Ba or Sr in M〓 is contained in a small amount (within 20 at. May be substituted with Ca. Further, the method for producing a rare earth element-activated divalent metal fluorohalide phosphor of the present invention includes a divalent metal fluoride that is at least one of BaF ₂ and SrF ₂ , and a halogen donor containing at least one of Br and I. an activator raw material which is one or more rare earth element compounds selected from the Eu compound group and the Sm compound group; and at least Al ₂ O ₃ and an Al compound that can be easily converted to Al ₂ O ₃ at high temperatures. Using either of the metal oxide raw materials, stoichiometrically M〓FX・xA:yLn (where M〓 is at least one of Ba and Sr)
species, A is Al ₂ O ₃ , Ln is at least one of Eu and Sm, X is at least one of Br and I, and x and y are each 5×10 ^-5 ≦
The present invention is characterized by preparing a phosphor raw material having the following composition (x≦0.5 and 0<y≦0.2) and firing this phosphor raw material. The present invention will be explained in detail below. The rare earth element-activated divalent metal fluorohalide phosphor of the present invention is manufactured by the manufacturing method described below. First, the raw materials include a divalent metal fluoride that is at least one of BaF ₂ and SrF ₂ , a halogen donor that includes at least one of Br and I, and one selected from the Eu compound group and the Sm compound group. The following four materials are used: an activator raw material that is a species or a compound of two or more rare earth elements, and a metal oxide raw material that is at least one of Al ₂ O ₃ and an Al compound that can be easily converted to Al ₂ O ₃ at high temperatures. It will be done. The halogen donor (above) is one that donates halogen, which is at least one of Br and I, which are constituent components of the phosphor, and this halogen donor includes Ba and Sr.
Halides (bromides and iodides) of divalent metals excluding fluorides and chlorides, ammonium salts of halogens excluding fluorine and chlorine (NH ₄ Br and NH ₄ I), etc. are used. As a halogen,
By using Br and I, using Cl as disclosed in the aforementioned U.S. Pat. No. 3,951,848
It is possible to obtain better afterglow characteristics than Al ₂ O ₃ doped europium activated barium fluorochloride phosphor. In addition, when the above-mentioned divalent metal halide is used as a halogen donor, this halogen donor not only donates at least one of Br and I, but also is another constituent of the phosphor of the present invention. It also donates some of the divalent metals. That is, when the halogen donor is not the above-mentioned divalent metal halide, the divalent metal that is a component of the obtained phosphor is provided only by the divalent metal fluoride (above), but when the halogen donor is Above 2
In the case of a valent metal halide, the divalent metal that is a component of the phosphor is provided by the divalent metal fluoride (above) and this halogen donor. The Eu and Sm compounds used as activator raw materials for the above) include oxides, halides,
Nitrates, carbonates, sulfates, etc. are used. Although these rare earth element compounds may be used in a solid state, it is more preferable to use them in the form of a solution in order to improve their diffusivity in the phosphor raw material. These rare earth element compound solutions contain rare earth element compounds.
It can be easily prepared by dissolving it in an acid such as HBr or HNO ₃ . Al ₂ O ₃ (above) serves to prevent sintering during the firing process, and remains in the resulting phosphor to improve the luminance brightness, powder fluidity, and afterglow properties of the phosphor. It is something. As mentioned above, in addition to Al ₂ O ₃ , compounds that can be easily converted to Al ₂ O ₃ at high temperatures can be used. Specific examples of Al compounds that can easily turn into Al ₂ O ₃ at this high temperature include compounds that easily decompose into Al ₂ O ₃ at high temperatures, such as nitrates, carbonates, sulfates, and hydroxides. . In addition, the metal oxide raw material has an average particle size of 10 to 1000.
It is preferable to use microparticles of . The average particle size is
If it is smaller than 10 Å, the metal oxide raw material particles tend to aggregate with each other, making it difficult to obtain a phosphor raw material in which the metal oxide raw material is uniformly diffused. On the other hand, if the average particle diameter is larger than 1000 Å, the effects of the present invention, such as the sintering prevention effect, will be small. Even within the above average particle size range, especially
The range is preferably 30 to 700 Å, more preferably
It ranges from 50 to 500 Å. Next, using the above four raw materials, stoichiometrically M〓FX・xA:yLn (where M〓 is at least one of Ba and Sr)
species, A is Al ₂ O ₃ , Ln is at least one of Eu and Sm, X is at least one of Br and I, and x and y are each 5×10 ^-5 ≦
A phosphor raw material having a composition (a number satisfying the conditions x≦0.5 and 0<y≦0.2) is prepared. The above
is preferably 10 ^-5 ≦x≦0.3, more preferably 10 ^-4 ≦x≦0.2. It goes without saying that in the above compositional formula, when Ln is composed of two types of rare earth elements, y indicates the total number of gram atoms of each rare earth element. The phosphor raw material may be prepared by simply mixing the above four raw materials, or alternatively the above)
Using the divalent metal fluoride of A divalent metal fluorohalide represented by
It may be prepared by mixing Al ₂ O ₃ or an Al compound, or it may be prepared by mixing the above) activator raw material and the above) Al ₂ O ₃ or Al compound. By reacting the divalent metal fluoride with the halogen donor (above) to produce the divalent metal fluorohalide containing the activator raw material and metal oxide raw material (AAl ₂ O ₃ or Al compound). May be prepared. Among the above three phosphor raw material preparation methods, the second and third
Better results can be obtained using this method. In the second and third phosphor raw material preparation methods, a divalent metal fluorohalide is prepared from a divalent metal fluoride and a halogen donor, or a divalent metal fluorohalide, a halogen donor, an activator raw material, and a metal oxide are used. Various methods are employed to produce divalent metal fluorohalides containing activator raw materials and metal oxide raw materials from raw materials. For example, a divalent metal fluorohalide or a divalent metal fluorohalide containing an activator raw material and a metal oxide raw material is
The valent metal fluoride and the divalent metal halide (halogen donor) mentioned above, or the divalent metal fluoride,
It can be easily produced by mixing a divalent metal halide, an activator raw material, and a metal oxide raw material and heating the resulting mixture at a temperature of 100° C. or higher for several hours (dry method). Alternatively, a divalent metal fluorohalide, or a divalent metal fluorohalide containing an activator raw material and a metal oxide raw material, can be prepared by adding a divalent metal halide solution to a suspension of a divalent metal fluoride, or adding a divalent metal halide solution to a suspension of a divalent metal fluoride. It can also be easily produced by adding a divalent metal fluoride, an activator raw material, and a metal oxide raw material, stirring thoroughly, and reacting a divalent metal fluoride with a divalent metal halide (wet method). ). The phosphor raw material obtained by the third method is a homogeneous mixture of divalent metal fluorohalide, activator raw material, and metal oxide raw material. In addition, when preparing a phosphor raw material by the above-mentioned second method, in both the above-mentioned dry method and wet method, divalent metal fluorohalide can be prepared by interposing an activator raw material in the reaction system. Uniform mixing of the divalent metal fluorohalide and the activator raw material can be achieved simultaneously with the production. In the first and second phosphor raw material preparation methods described above, a divalent metal fluoride, a halogen donor, an activator raw material, and a metal oxide raw material, or a divalent metal fluorohalide, an activator raw material, and a metal oxide raw material are used. are thoroughly mixed and used as a phosphor raw material. Mixing is carried out using a conventional mixer such as a stirrer equipped with stirring blades, various types of mixers, V-type blenders, ball mills, and rod mills. In addition, when the activator raw material is used as a solution, it is preferable to dry the formulation containing the activator raw material solution in advance, and then perform the above-mentioned mixing. In addition, as mentioned earlier, the metal oxide raw material has an average particle size of 10 to 10.
It is preferable to use fine particles of 1000 Å, but it is also preferable to use particles with a relatively small average particle size in the formulation excluding the metal oxide raw material, and usually particles with an average particle size of about 1 to about 100 μ are used. . Therefore, if the average particle size of the mixture excluding the metal oxide raw material is larger than approximately 100μ, the mixture is ground in advance and, in some cases, further classified to ensure that the average particle size falls within the above range. It is preferable to keep it as is. Grinding is carried out using a conventional grinder such as a mortar, ball mill, tube mill, or centrifugal mill. Note that this pulverization may be performed on the formulation after the metal oxide raw material has been added, or if it is performed on the formulation after the metal oxide raw material has been added, the mixing for preparing the phosphor raw material may be carried out. You can also do this at the same time. Further, the above-mentioned pulverization may be performed on the phosphor raw material prepared by the above-mentioned third method. The phosphor raw material prepared as described above is the same as the phosphor raw material used in the production of the conventional rare earth element-activated divalent metal fluorohalide phosphor (i.e., the metal oxide raw material is removed from the phosphor raw material used in the production method of the present invention). It exhibits extremely superior powder fluidity compared to other materials. This is thought to be because the hygroscopicity of conventional phosphor raw materials is alleviated by the inclusion of metal oxide raw materials. The improved powder fluidity of the phosphor raw material greatly facilitates the handling of the phosphor raw material, such as filling it into a heat-resistant container and up to the firing process described below. This improvement in the powder fluidity of the phosphor raw material is also one of the advantages of the manufacturing method of the present invention. Next, the phosphor raw material is filled into a heat-resistant container such as an aluminium crucible, a quartz crucible, or a quartz boat, and then placed in a firing furnace for firing. The firing atmosphere may be an ambient atmosphere (oxidizing atmosphere), a reducing atmosphere, or an inert atmosphere, but firing in an ambient atmosphere may oxidize the phosphor, so it is preferable. The calcination is carried out in a reducing atmosphere or in an inert atmosphere. As the reducing atmosphere, a nitrogen gas atmosphere containing 10% by volume or less of hydrogen gas, a carbon vapor atmosphere, etc. are used. Further, as the inert atmosphere, a nitrogen gas atmosphere, an argon gas atmosphere, etc. are used. Incidentally, as an extremely practical phosphor included in the rare earth element-activated divalent metal fluorohalide phosphor of the present invention, there is a phosphor using divalent Eu as an activator. A trivalent Eu compound is used as the raw material for the activator, and during the firing process, Eu is converted into trivalent Eu.
It is reduced from valence to bivalence. Therefore, this bivalent
When manufacturing a phosphor using Eu as an activator,
The firing atmosphere must be a reducing atmosphere. The firing temperature varies depending on the type of phosphor raw material (that is, the type of target phosphor), but generally the appropriate range is 600 to 1000°C, as in conventional manufacturing methods, and preferably 700 to 950°C. range. The firing time varies depending on the type of phosphor raw material, the amount of phosphor raw material packed into the heat-resistant container, the firing temperature, etc., but in the above firing temperature range, 30 minutes to 48 hours is generally appropriate, and preferably 1 The duration is between 12 hours and 12 hours. Note that, after firing under the above firing conditions, the fired product is once taken out of the firing furnace and mixed, and then fired again under the same conditions to further increase the luminance of the resulting phosphor. A phosphor is produced from the phosphor raw material through the above-mentioned firing process, but the resulting phosphor cannot be sintered like a conventional phosphor due to the sintering prevention effect of the metal oxide raw material contained in the phosphor raw material. It is not a powder, but a powder. Therefore, unlike conventional sintered phosphors, the phosphor obtained by firing does not need to be crushed and classified after firing, and can be used as is or after classification if necessary for various purposes. can do. As described above, in the production method of the present invention, the pulverization process after the firing process and the accompanying classification process are unnecessary, and therefore the production process can be shortened and the phosphor can be obtained in good yield.
Furthermore, the phosphor obtained by the manufacturing method of the present invention exhibits better phosphor properties than conventional phosphors, as described below. The rare earth element-activated divalent metal fluorohalide phosphor of the present invention manufactured by the manufacturing method described above has the composition formula M〓FX・xA:yLn (where M〓 is at least one of Ba and Sr). 1
species, A is Al ₂ O ₃ , Ln is at least one of Eu and Sm, X is at least one of Br and I, and x and y are each 5×10 ^-5 ≦
It is a number that satisfies the conditions x≦0.5 and 0<y≦0.2). That is, the phosphor of the present invention replaces the conventional Al ₂ O ₃ -doped europium activated barium fluorochloride phosphor with an Al ₂ O ₃ -doped rare earth element activated barium fluorobromide phosphor, or an Al ₂ O ₃ -doped rare earth element activated barium phosphor. This is an improved version of the fluoroiodide phosphor. The phosphor of the present invention exhibits higher luminance than conventional phosphors that do not contain metal oxides when excited by X-rays, ultraviolet rays, electron beams, etc. Shows better afterglow properties than the body. Among the phosphors of the present invention, phosphors whose phosphor raw materials are prepared by the above wet method seem to exhibit particularly excellent afterglow properties. Note that the emission spectrum of the phosphor of the present invention is substantially the same as that of a conventional phosphor that does not contain Al ₂ O ₃ . Further, the phosphor of the present invention is a constituent component thereof.
Hygroscopicity is moderated by Al ₂ O ₃ , which results in better powder flow than conventional phosphors that do not contain metal oxides. Therefore, the phosphor of the present invention is much easier to handle than conventional phosphors when used in various applications. Among the phosphors included in the rare earth element-activated divalent metal fluorohalide phosphor of the present invention, a divalent metal (having the above compositional formula) is a particularly practical phosphor.
M〓) is an alkaline earth metal which is at least one of Ba and Sr (however, as mentioned above, a part of it may be substituted with Ca), and the activator (in the above composition) Examples include divalent Eu-activated alkaline earth metal fluorohalide phosphors in which Ln) is divalent Eu. The amount of Al ₂ O ₃ (x in the above compositional formula) is the divalent metal fluorohalide (in the above compositional formula).
It is preferably 10 ^-5 to 0.3 mol, more preferably 10 ^-4 to 0.2 mol, per 1 mol of M FX). As explained above, according to the method for producing a rare earth element-activated divalent metal fluorohalide phosphor of the present invention, sintering of the phosphor during the firing process can be prevented. Also, the classification process involved therein can be omitted. Therefore, according to the manufacturing method of the present invention, the manufacturing process can be shortened, and the yield of the phosphor can be increased.
A rare earth element-activated divalent metal fluorohalide phosphor can be obtained at low cost. Furthermore, the production method of the present invention has manufacturing advantages such as no water washing step and high yield compared to production methods using fluxes. Moreover, the rare earth element activation 2 of the present invention
The valent metal fluorohalide phosphor is superior to conventional phosphors in terms of luminance, powder fluidity, and afterglow properties. As described above, the present invention improves both the cost and the phosphor properties of a rare earth element-activated divalent metal fluorohalide phosphor, and its industrial utility value is extremely large. Next, the present invention will be explained with reference to Examples. In addition,
The examples described below relate to a divalent Eu-activated alkaline earth metal fluorohalide phosphor, but other phosphors included in the phosphor of the present invention may also have effects depending on the type of phosphor. It was confirmed that the same effects as those described in the following examples can be obtained even though there is a difference. [Example 1] An example in which not only europium but also samarium is used as the rare earth element to be activated will be described. Weighed 87.68 g of special reagent grade BaF ₂ (manufactured by Morita Chemical Co., Ltd.) and 166.6 g of special reagent grade BaBr 2.2H ₂ O (manufactured _by Kanto Chemical Co., Ltd.), and thoroughly ground and mixed them in an agate mortar for 30 minutes. BaFBr was obtained by heating the resulting mixture at 150°C for 2 hours. I got it like this
A solution of reagent special grade Eu ₂ O ₃ (manufactured by Wako Pure Chemical Industries, Ltd.) dissolved in HBr was added to BaFBr at a concentration of Eu per mol of BaFBr.
10 ^-3 gram atoms, and further HBr
A solution of reagent grade Sm ₂ O ₃ (manufactured by Wako Pure Chemical Industries, Ltd.) dissolved in BaFBr was added thereto in an amount of 10 ^-3 gram atoms of Sm per mole of BaFBr, and thoroughly kneaded. The obtained slurry was dried by heating under reduced pressure at 130°C for 2 hours, and then pulverized and mixed for 2 hours in an automatic mortar made of high-purity alumina (GRINDO-MAT, manufactured by RETSCHMUHLE) to form BaFBr, EuBr ₃ and
A mixture of _SmBr3 was obtained. Next, high purity Al ₂ O ₃ fine particles (manufactured by Nippon Aerosil Co., Ltd.) with an average particle diameter of 50 to 200 Å were added to the above mixture.
A phosphor raw material was prepared by adding 0.056 mol per mol of BaFBr. The powder fluidity of this phosphor raw material was extremely good, and no aggregation of particles was observed. 20 g of the phosphor raw material prepared as described above was taken, placed in a quartz board, and fired in a tube furnace. Firing was carried out at 900° C. for 4 hours while flowing nitrogen gas containing 1% by volume of hydrogen gas at a flow rate of 280 c.c./min. After firing, the quartz board was taken out of the tube furnace and allowed to cool to room temperature until the composition formula was BaFBr.
A phosphor represented by 0.056Al ₂ O ₃ :0.001Eu ²⁺ , 0.001Sm was obtained. This phosphor was not sintered and was obtained as a powder. On the other hand, for comparison, the above BaFBr, EuBr ₃ and
A phosphor was obtained by firing a mixture of SmBr ₃ under the same firing conditions as above without adding and mixing a metal oxide raw material (Al ₂ O ₃ or the Al compound). Since the obtained phosphor was sintered, it was placed in the automatic mortar body mentioned above.
It was ground for 30 minutes to form a powder. The phosphor of the present invention obtained as described above exhibits luminance about four times as high as that of a phosphor that is not mixed with a metal oxide raw material (Al ₂ O ₃ or the aforementioned Al compound), and also has excellent powder fluidity. The yield of classification using a sieve was also extremely high. [Example 2] The afterglow characteristics of the phosphor of the present invention and a conventional fluorochloride phosphor containing a metal oxide and a fluorohalide phosphor not containing a metal oxide were compared. 1 First, a method for synthesizing an Al ₂ O ₃ -doped europium-activated barium fluorochloride phosphor, which is a comparison sample, will be described. Reagent special grade BaF ₂ (manufactured by Morita Chemical Co., Ltd.) 87.68g and reagent special grade BaCl _{2.2H 2} O (manufactured by Kanto Chemical Co., Ltd.) 122.16g
were weighed, thoroughly ground and mixed in an agate mortar for 30 minutes, and the resulting mixture was heated at 150° C. for 2 hours to obtain BaFCl. In this BaFCl
Reagent grade Eu ₂ O ₃ dissolved in HCl (Wako Pure Chemical Industries, Ltd.)
0.001 gram atom of Eu per 1 mol of BaFCl was added to the solution (manufactured by Nippon Steel Co., Ltd.) and thoroughly kneaded.
The obtained slurry was dried by heating under reduced pressure at 130°C for 2 hours, and then placed in a high-purity alumina automatic mortar (GRINDOMAT manufactured by RETSCH-MUHLE).
A mixture of BaFCl and EuCl ₃ was obtained by pulverization and mixing for 2 hours. Next, high-purity Al ₂ O ₃ fine particles (manufactured by Nippon Aerosil Co., Ltd.) with an average particle diameter of 50 to 200 Å were added to the mixture of BaFCl and EuCl ₃ at a rate of 0.056 molar per mole of BaFCl.
Add only moles and mixer (Willy A.
The phosphor raw material was prepared by mixing for 30 minutes at 90 revolutions per minute in TURBULA (manufactured by Bachofen). 20g of the phosphor raw material prepared as above
It was then placed in a quartz board and fired in a tube furnace. Firing was carried out at 900° C. for 4 hours while flowing nitrogen gas containing 1% by volume of hydrogen gas at a flow rate of 280 c.c./min. After firing, the quartz board was taken out of the tube furnace and allowed to cool to room temperature. 2 On the other hand, an Al ₂ O ₃ -doped europium-activated barium fluorobromide phosphor, which is a phosphor of the present invention, was obtained as follows. Reagent special grade BaF ₂ (manufactured by Morita Chemical Co., Ltd.) 87.68g and reagent special grade BaBr ₂・2H ₂ O (manufactured by Kanto Chemical Co., Ltd.) 166.6g
were weighed, thoroughly ground and mixed in an agate mortar for 30 minutes, and the resulting mixture was heated at 150° C. for 2 hours to obtain BaFBr. In this BaFBr
Reagent grade Eu ₂ O ₃ dissolved in HBr (Wako Pure Chemical Industries, Ltd.)
0.001 Eu per mole of BaFBr
It was added so as to make gram atoms and thoroughly kneaded. The resulting slurry was treated in the same manner as for the fluorochloride phosphor described above, and BaFBr
A mixture of and EuBr ₃ was obtained. The same Al ₂ O ₃ as in the case of the above-mentioned fluorochloride phosphor was added to this and mixed in the same manner to prepare a phosphor raw material.
The powder fluidity of this phosphor raw material was extremely good, and no aggregation of particles was observed. The phosphor raw material thus obtained was fired in the same manner as in the case of the fluorochloride phosphor described above to obtain a phosphor. This phosphor is not sintered,
Obtained as a powder. 3 Furthermore, an Al ₂ O ₃ -doped europium-activated barium fluoroiodide phosphor, which is a phosphor of the present invention, was obtained as follows. Weighed 175.34 g of reagent special grade BaF ₂ (manufactured by Morita Chemical Co., Ltd.) and 427.18 g of reagent special grade BaI 2.2H ₂ O (manufactured by Kanto Chemical Co., _Ltd. ), and thoroughly ground and mixed them in an agate mortar for 30 minutes. BaFI was obtained by heating the resulting mixture at 150°C for 2 hours. A solution of reagent grade Eu ₂ O ₃ (manufactured by Wako Pure Chemical Industries, Ltd.) dissolved in HI was added to this BaFI so that Eu was 0.001 gram atom per mole of BaFI, and the mixture was thoroughly kneaded. The resulting slurry was treated in the same manner as for the fluorochloride phosphor and fluorobromide phosphor described above to obtain a mixture of BaFI and EuI ₃ . This is followed by the same method as in the case of the fluorochloride phosphor and fluorobromide phosphor described above.
A phosphor raw material was prepared by adding Al ₂ O ₃ and mixing in the same manner. The powder fluidity of this phosphor raw material was also very good, and no aggregation of particles was observed. The phosphor raw material thus obtained was fired in the same manner as in the case of the fluorochloride and fluorobromide phosphors described above to obtain a phosphor. This phosphor was also not sintered and was obtained as a powder. 4 The compositional formulas of the three types of phosphors obtained as described above (referred to as comparative samples, sample 1, and sample 2, respectively) are as follows. Comparison sample BaFCl・0.056Al ₂ O ₃ : 0.001Eu Sample 1 BaFBr・0.056Al ₂ O ₃ : 0.001Eu Sample 2 BaFI・0.056Al ₂ O ₃ : 0.001Eu 5 Each of the above samples was described in Example 1. A fluorohalide phosphor containing no metal oxide was prepared and compared. 6 The afterglow characteristics of the phosphor of the present invention and a conventional fluorochloride phosphor containing a metal oxide and a fluorohalide phosphor not containing a metal oxide were compared. The results are shown in Table 1 below.

[Table] Yes.
As is clear from Table 1 above, the phosphors of the present invention (samples 1 and 2) have smaller values of relative afterglow brightness than the conventional fluorochloride phosphors (comparison sample) and have superior characteristics. be. In addition, the phosphor of the present invention (samples 1 and 2)
The relative afterglow afterglow brightness of the conventional fluorochloride phosphor (comparison sample) increases (deteriorates) with the addition of Al ₂ O ₃ , whereas the relative afterglow afterglow brightness increases with the addition of Al ₂ O ₃ . decreases (improves).

Claims (1)

[Claims] 1. The compositional formula is M〓FX・xA:yLn (where M〓 is at least one of Ba and Sr)
species, A is Al ₂ O ₃ , Ln is at least one of Eu and Sm, X is at least one of Br and I, and x and y are each 5×10 ^-5 ≦
A rare earth element-activated divalent metal fluorohalide phosphor, which is a number satisfying the following conditions: x≦0.5 and 0<y≦0.2. 2. The phosphor according to claim 1, wherein x is a number satisfying the condition 10 ^-5 ≦x≦0.3. 3. The phosphor according to claim 2, wherein x is a number satisfying the condition 10 ^-4 ≦x≦0.2. 4. The phosphor according to claim 1, wherein the M〓 is Ba and the Ln is divalent Eu. 5 At least one of BaF ₂ and SrF ₂
a divalent metal fluoride as a species, a halogen donor containing at least one of Br and I, an activator that is one or more rare earth element compounds selected from the Eu compound group and the Sm compound group; and a metal oxide raw material which is at least one of Al ₂ O ₃ and an Al compound that can be easily converted to Al ₂ O ₃ at high temperatures. At least one of Ba and Sr
species, A is Al ₂ O ₃ , Ln is at least one of Eu and Sm, X is at least one of Br and I, and x and y are each 5×10 ^-5 ≦
A rare earth element-activated divalent metal fluorohalide characterized by preparing a phosphor raw material having the composition (x≦0.5 and 0<y≦0.2) and firing this phosphor raw material. Method of manufacturing phosphor. 6 Using the above divalent metal fluoride and the above halogen donor, the composition formula is M〓FX (where M〓 is at least one of Ba and Sr).
species, X is at least one of Br and I) and mixing the above activator raw material and the above metal oxide raw material of the divalent metal fluorohalide. 6. The manufacturing method according to claim 5, wherein the phosphor raw material is prepared by: 7 The above divalent metal fluoride, the above halogen donor,
Using the above activator raw material and the above metal oxide raw material, the composition formula containing the above activator raw material and the above metal oxide raw material is M〓FX (where M〓 is at least one of Ba and Sr).
A divalent metal fluorohalide represented by the species X is at least one of Br and I is produced, and this is used as the raw material for the phosphor. Production method. 8 The above divalent metal fluoride, the above halogen donor,
6. The manufacturing method according to claim 5, wherein the phosphor raw material is prepared by mixing the activator raw material and the metal oxide raw material. 9. The manufacturing method according to any one of claims 5 to 8, wherein x is a number satisfying the condition 10 ^-5 ≦x≦0.3. 10. The manufacturing method according to claim 9, wherein x is a number satisfying the condition 10 ^-4 ≦x≦0.2. 11 The average particle diameter of the metal oxide raw material is 10 to 10.
10. The manufacturing method according to any one of claims 5 to 10, characterized in that the thickness is 1000 Å. 12 The average particle diameter of the metal oxide raw material is 30 to 30.
12. The manufacturing method according to claim 11, wherein the thickness is 700 Å. 13 The average particle size of the metal oxide raw material is 50 to 50.
13. The manufacturing method according to claim 12, wherein the thickness is 500 Å.