JP2006233136A - Method for producing phosphor composition and phosphor composition obtained by the method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a phosphor composition that has high emission intensity, is reduced in cost and is applied to a scintillator material and a phosphor material, contains no impurity structure having adverse effect on luminous efficiency and is constituted of a high-purity single crystal structure. <P>SOLUTION: The phosphor composition is obtained by dropping a phosphor composition raw material in a solution of a phosphor composition raw material to a solution of an alkali-based precipitant to precipitate a phosphor composition precursor, washing the obtained phosphor composition precursor with water and then firing the washed phosphor composition precursor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing a phosphor composition and a phosphor composition obtained thereby. More preferably, the phosphor composition can be applied to scintillators used in radiation detectors such as gamma rays, X-rays, and neutron rays, phosphors for plasma displays (PDP), phosphors for cathode ray tubes (CRT), phosphors for projection tubes, etc. The present invention relates to a method for manufacturing a product.

The phosphor composition has a wide range of uses such as a phosphor for display such as PDP, CRT, and projection tube, and a scintillator used for radiation detectors such as gamma rays, X-rays, and neutron rays. From the viewpoint of reducing the power consumption of various devices, there is a demand for phosphors with good luminous efficiency. One of the factors affecting the luminous efficiency is the structural uniformity of the phosphor base material, and it is required to synthesize a phosphor base material composed of a single crystal structure. For example, when Y ₂ SiO ₅ : Tb, which is one of green phosphors, is synthesized by a conventional method that does not include a phosphor composition precursor cleaning step, in addition to the main structure Y ₂ SiO ₅ phase, Generation of a Y ₂ O ₃ phase that is an impurity structure is recognized from the X-ray diffraction pattern of the phosphor composition (see, for example, Non-Patent Document 1).
Yun Chan Kang et al., J. Solid State Chem. 146, 168-175 (1999)

  The present invention provides a method for producing a phosphor composition having a high-purity crystal structure, with respect to a phosphor composition that can be applied to a scintillator material and a phosphor material that have high emission intensity and can be reduced in cost. Objective.

  In order to solve the above-mentioned problems, the present inventors have removed residues such as alkali components remaining in the phosphor composition precursor obtained by the reaction of the phosphor composition raw material solution and the alkaline precipitant. The above problem is solved by removing the residue by washing the phosphor composition precursor obtained by the reaction between the phosphor composition raw material solution and the alkaline precipitant multiple times with water. The present inventors have found that the present invention can be accomplished and have completed the present invention.

That is, the present invention relates to the following phosphor composition manufacturing method and the phosphor composition obtained by the manufacturing method.
(1) The phosphor composition raw material in the phosphor composition raw material solution is dropped into the alkaline precipitant solution to precipitate the phosphor composition precursor, and the obtained phosphor composition precursor is washed with water. And then firing the phosphor composition.

  (2) The method for producing a phosphor composition according to (1), wherein the phosphor composition precursor is washed with water until the pH of the washed water becomes 7-8.

  (3) Production of the phosphor composition according to (1) or (2), wherein when preparing the phosphor composition precursor, the phosphor composition raw material solution is dropped into an alkaline precipitant solution. Method.

  (4) The phosphor composition raw material contains at least one compound of at least one element selected from the group consisting of at least one alkaline earth element, at least one rare earth element, aluminum, and silicon. The method for producing a phosphor composition according to any one of (1) to (3).

  (5) The alkaline earth element compound is an alkaline earth element nitrate, chloride or sulfate, the rare earth element compound is a rare earth element nitrate, chloride or sulfate, and the aluminum compound is aluminum nitrate, It is aluminum chloride, aluminum sulfate, or aluminum alkoxide, and the compound of silicon is tetraalkoxysilane or silica sol, The manufacturing method of the fluorescent substance composition in any one of Claims 1-4.

(6) The phosphor composition has the general formula [1]
(A ₂ O ₃ ) _x (B ₂ O ₃ ) _y (SiO ₂ ) _z [1]
(However, when x + y + z = 1, 0 <x <0.5, 0 <y <0.5, 0 <z <0.95, and A is at least one selected from Gd, Y, Lu and La. The element B represents at least one rare earth element other than A.)
The phosphor according to any one of (1) to (5), comprising a crystalline substance that emits light in the ultraviolet, visible, or infrared region by light stimulation, electron beam stimulation, or radiation stimulation. A method for producing the composition.

(7) The method for producing a phosphor composition according to (6), wherein the crystalline crystal structure is the same type as that of Y ₂ SiO ₅ .

(8) The phosphor composition has the general formula [2]
(A ₂ O ₃ ) _a (B ₂ O ₃ ) _b (Al ₂ O ₃ ) _c [2]
(However, when a + b + c = 1, 0 <a <0.375, 0 <b <0.375, 0 <c <0.85, and A is at least one selected from Gd, Y, Lu and La. The element B represents at least one rare earth element other than A.)
The phosphor according to any one of (1) to (5), comprising a crystalline substance that emits light in the ultraviolet, visible, or infrared region by light stimulation, electron beam stimulation, and radiation stimulation. A method for producing the composition.

(9) The method for producing a phosphor composition according to (8), wherein the crystalline crystal structure is the same type as that of Y ₃ Al ₅ O ₁₂ .

(10) The phosphor composition has the general formula [3]
(QO) _d (BO) _e (RO) _f (SiO _z ) _g [3]
(However, when d + e + f + g = 1, 0 <d <0.25, 0 <e <0.25, 0 <f <0.4, 0 <g <0.95, and B is selected from rare earth elements. (At least one element, Q represents at least one element selected from Mg, Ca, Sr, Ba and Ra, and R represents at least one alkaline earth element other than Q.)
The phosphor composition according to any one of (1) to (5), comprising a crystalline material that emits light in the ultraviolet, visible, or infrared region by light stimulation, electron beam stimulation, or radiation stimulation. Manufacturing method.

(11) The method for producing a phosphor composition according to (10), wherein the crystalline crystal structure is the same type as that of CaMgSi ₂ O ₆ .

(12) The phosphor composition has the general formula [4].
(QO) _h (BO) _i (RO) _k (Al ₂ O ₃ ) _m [4]
(However, when h + i + k + m = 1, 0 <h <0.143, 0 <i <0.143, 0 <k <0.3, 0 <m <0.95, and B is selected from rare earth elements. (At least one element, Q represents at least one element selected from Mg, Ca, Sr, Ba and Ra, and R represents at least one alkaline earth element other than Q.)
The phosphor composition according to any one of (1) to (5), comprising a crystalline material that emits light in the ultraviolet, visible, or infrared region by light stimulation, electron beam stimulation, or radiation stimulation. Manufacturing method.

(13) The method for producing a phosphor composition according to (12), wherein the crystalline crystal structure is the same type as BaMgAl ₁₀ O ₁₇ .

  (14) A phosphor composition manufactured by the method for manufacturing a phosphor composition according to any one of (1) to (13).

  INDUSTRIAL APPLICABILITY According to the present invention, a phosphor composition that has a high emission intensity and can be applied to a low-cost scintillator material and phosphor material can be provided with a method for producing a phosphor composition having a high-purity crystal structure.

  Examples of the phosphor composition material used in the present invention include compounds of at least two elements selected from the group consisting of at least one alkaline earth element, at least one rare earth element, aluminum, and silicon. The mixture which contains is mentioned.

  Examples of alkaline earth element compounds include alkaline earth element nitrates, chlorides and sulfates. Examples of rare earth element compounds include nitrates, chlorides and sulfates of rare earth elements. Examples of the aluminum compound include aluminum nitrate, aluminum chloride, aluminum sulfate, and aluminum alkoxide such as aluminum methoxide and aluminum ethoxide. Examples of silicon compounds include tetraalkoxysilanes such as tetramethoxysilane and tetraethoxysilane, and silica sol. As the silicon compound, it is preferable to use a silica sol obtained by hydrolyzing tetraalkoxysilane in a hydrochloric acid catalyst.

  As the phosphor composition raw material solution, for example, an aqueous solution or an alcohol solution in which the phosphor composition raw material is dissolved in water or an alcohol solvent is preferable. The concentration of the phosphor composition raw material in the phosphor composition raw material solution is preferably 1 to 50% by weight, more preferably 3 to 40% by weight as the solid content in the solution.

As the alkaline precipitant, ammonia is preferable, and it is usually preferable to use ammonia water. Examples include JIS special grade 28-30 wt% ammonia water manufactured by Kanto Chemical Co., Ltd., Wako Pure Chemical reagent special grade 25 wt% ammonia water, Wako Pure Chemical reagent first grade 25 wt% ammonia water, and the like. Pharmaceutical reagent special grade 25% by weight ammonia water is preferred.
In addition, the aqueous ammonia can be further diluted with a solvent such as water or alcohol according to the volume and concentration of the phosphor composition raw material solution.

Alkaline precipitants other than ammonium can also be used, such as ammonium hydrogen carbonate, imidazole, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, sodium hydroxide, water Potassium oxide, sodium hydrogen carbonate and the like can also be used. These alkaline precipitants are also preferably used as an aqueous solution or an alcohol solution.
It is also possible to use a surfactant mixed with an alkaline precipitant.

  When the alkaline precipitant is used as an aqueous solution or an alcoholic solution, the concentration of the alkaline precipitant is preferably 1 to 30% by weight, and more preferably 4 to 25% by weight.

  A phosphor composition precursor is obtained by a liquid phase reaction between a phosphor composition raw material and an alkaline precipitant using a phosphor composition raw material solution. In order to uniformly produce a phosphor composition precursor, Is a reaction in which the phosphor composition raw material solution is dropped into an alkaline precipitant solution. In this reaction method, the reaction temperature is not particularly limited, and room temperature is sufficient. For example, the reaction system is preferably reacted at a temperature of 15 to 30 ° C., more preferably 20 to 27 ° C. while stirring the reaction system. desirable. Moreover, it is desirable to continue stirring after the completion of dropping, preferably for 5 to 30 minutes, more preferably for 10 to 20 minutes.

The washing of the phosphor composition precursor obtained as a precipitate with water is preferably performed until the pH of the washed water becomes 7 to 8, more preferably until the pH becomes 7 to 7.5. It is particularly preferable to carry out until the pH reaches 7 to 7.2.
The water used for washing is preferably ultrapure water, preferably water having an electrical resistivity of 18 MΩ · cm or more, more preferably 18 to 18.2 MΩ · cm. 10-25 degreeC is preferable and the temperature of water has more preferable 15-20 degreeC.

The phosphor composition precursor is preferably washed by dispersing the phosphor composition precursor in water and then performing re-separation by centrifugation a plurality of times until the above conditions are satisfied.
Centrifugation is preferably performed by selecting a rotation speed and a time at which the phosphor composition precursor is not confirmed to flow out to water. For example, when an apparatus having a rotation radius of 20 cm is used, the rotation speed is 1000 rpm to 4000 rpm. The time is preferably 3 to 10 minutes, more preferably at a rotational speed of 2000 rpm to 3000 rpm and a separation time of 4 to 7 minutes, and particularly preferably at a rotational speed of 3000 rpm and a separation time of 4 to 5 minutes.

  The phosphor composition can be obtained by calcination of the phosphor composition precursor after washing with water as described above. The phosphor composition can be obtained in an air atmosphere, an inert atmosphere such as nitrogen, or a reducing atmosphere such as diluted hydrogen. It can also be obtained by firing in an atmosphere. Particularly preferred is an inert atmosphere such as nitrogen. The firing temperature is preferably 1000 to 1600 ° C, more preferably 1100 to 1500 ° C, and the firing time is preferably 3 to 10 hours, more preferably 5 to 8 hours.

  According to the production method of the present invention, for example, the compositions [1], [2], [3] and [4] represented by the following general formulas [1], [2], [3] and [4], respectively. It is possible to obtain a phosphor composition containing a crystalline substance that emits light in the ultraviolet, visible, or infrared region by light stimulation, electron beam stimulation, or radiation stimulation. These phosphor compositions emit light in the ultraviolet, visible, or infrared region by at least one of light stimulation, electron beam stimulation, and radiation stimulation.

Phosphor composition [1]
(A ₂ O ₃ ) _x (B ₂ O ₃ ) _y (SiO ₂ ) _z [1]
(However, when x + y + z = 1, 0 <x <0.5, 0 <y <0.5, 0 <z <0.95, preferably 0.44 <x <0.495, 0.005 < y <0.06, 0.2 <z <0.8, more preferably 0.455 <x <0.485, 0.015 <y <0.045, 0.4 <z <0.6. A represents at least one element selected from Gd, Y, Lu and La, and B represents at least one rare earth element other than A.)

Phosphor composition [2]
(A ₂ O ₃ ) _a (B ₂ O ₃ ) _b (Al ₂ O ₃ ) _c [2]
(However, when a + b + c = 1, 0 <a <0.375, 0 <b <0.375, 0 <c <0.85, preferably 0.3375 <a <0.37125, 0.00375 < b <0.0375, 0.2 <c <0.75, more preferably 0.3525 <a <0.3675, 0.0075 <b <0.0225, 0.4 <c <0.65 A represents at least one element selected from Gd, Y, Lu and La, and B represents at least one rare earth element other than A.)

Phosphor composition [3]
(QO) _d (BO) _e (RO) _f (SiO _z ) _g [3]
(However, when d + e + f + g = 1, 0 <d <0.25, 0 <e <0.25, 0 <f <0.4, 0 <g <0.95, preferably 0.2125 <d. <0.2475, 0.0025 <e <0.0375, 0.1 <f <0.35, 0.2 <g <0.8, more preferably 0.2225 <d <0.2375, 0.0125 <e <0.0275, 0.2 <f <0.3, 0.4 <g <0.6, B is at least one element selected from rare earth elements, Q is Mg, Ca And at least one element selected from Sr, Ba and Ra, and R represents at least one alkaline earth element other than Q.)

Phosphor composition [4]
(QO) _h (BO) _i (RO) _k (Al ₂ O ₃ ) _m [4]
(However, when h + i + k + m = 1, 0 <h <0.143, 0 <i <0.143, 0 <k <0.3, 0 <m <0.95, preferably 0.12155 <h. <0.14157, 0.00143 <i <0.02145, 0.05 <k <0.25, 0.2 <m <0.8, more preferably 0.12727 <h <0.13585, 0.00715 <i <0.01573, 0.1 <k <0.2, 0.5 <m <0.75, B is at least one element selected from rare earth elements, Q is Mg, Ca And at least one element selected from Sr, Ba and Ra, and R represents at least one alkaline earth element other than Q.)

As the phosphor composition [1], the phosphor composition [5] having the same crystalline crystal structure as that of Y ₂ SiO ₅ is preferable.
As the phosphor composition [2], the phosphor composition [6] in which the crystalline crystal structure is the same type as that of Y ₃ Al ₅ O ₁₂ is preferable.
As the phosphor composition [3], a phosphor composition [7] having the same crystalline crystal structure as that of CaMgSi ₂ O ₆ is preferable.
As the phosphor composition [4], the phosphor composition [8] having the same crystalline crystal structure as that of BaMgAl ₁₀ O ₁₇ is preferable.

In the phosphor compositions [5] to [8], “the crystal structures are the same type as Y ₂ SiO ₅ , Y ₃ Al ₅ O ₁₂ , CaMgSi ₂ O ₆ and BaMgAl ₁₀ O ₁₇ , respectively. "" Means that each phosphor composition is formed only by the same type of crystal structure as the structure shown in [5] to [8]. For example, in the case of the phosphor composition in which A is Y and B is Tb in the formula [1], in the case of the conventional phosphor composition, in addition to the crystal structure of the same type as Y ₂ SiO ₅ , Y ₂ Si ₂ Although the O ₇ structure and the Y ₂ O ₃ structure may be included, the phosphor composition [5] of the present invention is constituted only by the same type of crystal structure as the Y ₂ SiO ₅ structure.

Further, among these phosphor compositions [1] to [8], A is Y in the general formulas [1] to [4], B is Tb, Ce or Eu, and Q is Ba or Ca. A phosphor composition in which R is Mg is preferable.
In particular, the rare earth element A constituting the phosphor base material is preferably Y for use in phosphors for electron beam stimulation or ultraviolet light stimulation, and Gd, Lu, La, etc. can be efficiently applied for use in scintillators.
Similarly, the alkaline earth element Q constituting the phosphor base material is preferably Ba for phosphor applications, and Ca and Sr can also be efficiently applied.
Further, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb and the like having a light emission wavelength in the visible region or the infrared region can be suitably applied as the B element that functions as an activator.

[Example 1]
A = Y, B = Tb are selected as constituent elements of the phosphor composition described in the general formula [1], and composition x = 0.465, y = 0.035, and z = 0.5 are synthesized by the following method. did.
Yttrium nitrate aqueous solution (concentration: 19.2% by weight), terbium nitrate aqueous solution (concentration: 4.5% by weight), and tetraethoxysilane were prepared as raw materials for Y, Tb, and Si components, respectively.
Phosphor composition is mixed with silica sol liquid (solid content concentration: 20.8% by weight) obtained by pre-hydrolyzing tetraethoxysilane under a hydrochloric acid catalyst so as to have a predetermined composition. A raw material solution was prepared.
The silica sol solution was prepared as follows. Specifically, 5 ml of 1 mol / l HCL and 2.5 ml of ultrapure water were added to 20.8 g of tetraethoxysilane, and stirring was continued for 5 minutes until the exotherm subsided. Then, it diluted with ethanol until it became a density | concentration of 20.8 weight%.
Next, 60 ml of the raw material solution was added dropwise to 60 ml of 25 wt% aqueous ammonia while stirring at a temperature of 20 ° C. After completion of the dropwise addition, stirring was continued for 15 minutes at the same temperature to prepare a phosphor composition precursor (precipitate). .
Washing of the phosphor composition precursor with water (500 ml, 15 ° C.) and solid-liquid separation by centrifugation (rotation radius 20 cm, rotation speed 3000 rpm, separation time 5 minutes) are repeated 5 times to eliminate ammonia odor and after washing After confirming that the pH of the water became 7.8, it was dried at 150 ° C. for 2 hours to obtain 3.4 g of a powder sample.
The sample was then heat-treated in air at 1500 ° C. for 8 hours to obtain 2.5 g of a powder sample of the phosphor composition.
When the produced sample was irradiated with an ultraviolet lamp, green light emission was observed.
Next, the crystal structure by X-ray diffraction of the powder sample of the phosphor composition obtained after the heat treatment was evaluated.
The results are shown in FIG. 1 and FIG. The measurement conditions for X-ray diffraction in each figure are as follows.
Fig. 1: Measuring range 10-80 °, step width 0.05 °, counting time 2 seconds Fig. 2: Measuring range 27-30 °, step width 0.02 °, counting time 5 seconds

As a result of X-ray diffraction, the 150 ° C. dry powder showed an amorphous pattern, while the 1500 ° C. fired product showed a diffraction pattern consisting of a number of peaks indicating the presence of a crystalline phase as shown in FIG.
The diffraction pattern coincided with the diffraction pattern of Y ₂ SiO ₅ (JCPDS card No. 21-1458) as shown in FIG.
When Y ₂ O ₃ is present as an impurity phase, a peak is shown at 2θ = 29.16 ° (JCPDS card No. 25-1200), but no peak is observed at the angular position as shown in FIG. It was confirmed that only Y ₂ SiO ₅ exists as a crystal structure.

[Example 2]
A phosphor composition precursor was prepared by the same constituent elements, composition, and method as in Example 1.
A powder sample 3.4 g obtained by carrying out the method of the present invention and dried was heat-treated at 1300 ° C. for 8 hours in a nitrogen atmosphere to obtain 2.5 g of a powder sample of the phosphor composition.
When the produced sample was irradiated with an ultraviolet lamp, green light emission was observed.
Next, the crystal structure of each powder sample by X-ray diffraction was evaluated.
As a result of X-ray diffraction, as in Example 1, it was confirmed that only Y ₂ SiO ₅ was present as a crystal structure.

[Comparative Example 1]
The same constituent elements and compositions (x = 0.465, y = 0.035, z = 0.5) as in Example 1 were selected, and a phosphor composition raw material solution was prepared in the same manner as in Example 1.
Next, 60 ml of 25 wt% ammonia water was dropped into 60 ml of the raw material solution while stirring at a temperature of 20 ° C. After completion of the dropping, stirring was continued for 15 minutes at the same temperature to prepare a phosphor composition precursor (precipitate). did.
Washing of the phosphor composition precursor with water (500 ml, 15 ° C.) and solid-liquid separation by centrifugation (rotation radius 20 cm, rotation speed 3000 rpm, separation time 5 minutes) are repeated 5 times to eliminate ammonia odor and after washing After confirming that the pH of the water became 7.8, it was dried at 150 ° C. for 2 hours to obtain 3.4 g of a powder sample.
The sample was then heat-treated in air at 1500 ° C. for 8 hours to obtain 2.5 g of a powder sample of the phosphor composition.
When the produced sample was irradiated with an ultraviolet lamp, green light emission was observed.
Next, the crystal structure of each powder sample by X-ray diffraction was evaluated.
Results of X-ray diffraction peaks were observed attributable to the Y ₂ O ₃ in the 2 [Theta] = 29.16 °, it was confirmed that there is in addition to Y ₂ O ₃ of Y ₂ SiO ₅ as a crystal structure.

[Example 3]
A = Y and B = Ce are selected as constituent elements of the phosphor composition described in the general formula [2], and the composition a = 0.36, b = 0.015, c = 0.625 is synthesized by the following method did.
As raw materials for Y, Ce, and Al components, yttrium nitrate aqueous solution (concentration: 19.2% by weight), cerium nitrate aqueous solution (concentration: 4.3% by weight), and aluminum nitrate aqueous solution (concentration: 37.5% by weight), respectively. Prepared.
The Y, Ce, and Al raw material aqueous solutions were mixed so as to have a predetermined composition to prepare a phosphor composition raw material solution.
Next, 60 ml of the raw material solution was added dropwise to 60 ml of 4 wt% aqueous ammonia while stirring at a temperature of 20 ° C. After completion of the dropwise addition, stirring was continued for 15 minutes at the same temperature to prepare a phosphor composition precursor (precipitate). .
Washing of the phosphor composition precursor with water (500 ml, 20 ° C.) and solid-liquid separation by centrifugation (rotation radius 20 cm, rotation speed 3000 rpm, separation time 5 minutes) are repeated three times, the ammonia odor disappears, and after washing After confirming that the pH of the water became 7.7, it was dried at 150 ° C. for 2 hours to obtain 3.6 g of a powder sample.
The sample was then heat-treated in air at 1200 ° C. for 5 hours to obtain 2.7 g of a powder sample of the phosphor composition.
When the prepared sample was irradiated with light of 470 nm, yellow light emission was observed.
Next, the crystal structure of each powder sample by X-ray diffraction was evaluated.
The results are shown in FIG. 3 and FIG. The measurement conditions for X-ray diffraction in each figure are as follows.
Fig. 3: Measurement range 10-80 °, step width 0.05 °, counting time 1 second Fig. 4: Measurement range 26-30 °, step width 0.02 °, counting time 10 seconds

As a result of X-ray diffraction, the 150 ° C. dry powder showed an amorphous pattern, while the 1200 ° C. fired product showed a diffraction pattern consisting of a number of peaks indicating the presence of a crystalline phase as shown in FIG.
The diffraction pattern coincided with the diffraction pattern of Y ₃ Al ₅ O ₁₂ (JCPDS card No. 8-178) as shown in FIG.
Further, it is conceivable that Y ₂ O ₃ is present as the impurity phase as in Example 1, but no peak was observed at 2θ = 29.16 ° as shown in FIG.
Similarly, Y ₄ Al ₂ O ₉ (JCPDS card No. 22-987), YAlO ₃ (JCPDS card No. 11-662), or Al ₂ O ₃ (JCPDS card No. 10-173) exists as an impurity phase. However, these peaks were not observed, and it was confirmed that only Y ₃ Al ₅ O ₁₂ was present as the crystal structure.

[Comparative Example 1]
The same constituent elements and compositions (x = 0.465, y = 0.035, z = 0.5) as in Example 1 were selected, and a phosphor composition raw material solution was prepared in the same manner as in Example 1.
Next, 60 ml of 25 wt% ammonia water was dropped into 60 ml of the raw material solution while stirring at a temperature of 20 ° C. After completion of the dropping, stirring was continued for 15 minutes at the same temperature to prepare a phosphor composition precursor (precipitate). did.
Washing of the phosphor composition precursor with water (500 ml, 15 ° C.) and solid-liquid separation by centrifugation (rotation radius 20 cm, rotation speed 3000 rpm, separation time 5 minutes) are repeated 5 times to eliminate ammonia odor and after washing After confirming that the pH of the water became 7.8, it was dried at 150 ° C. for 2 hours to obtain 3.4 g of a powder sample.
The sample was then heat-treated in air at 1500 ° C. for 8 hours to obtain 2.5 g of a powder sample of the phosphor composition.
When the produced sample was irradiated with an ultraviolet lamp, green light emission was observed.
Next, the crystal structure of each powder sample by X-ray diffraction was evaluated.
Results of X-ray diffraction peaks were observed attributable to the Y ₂ O ₃ in the 2 [Theta] = 29.16 °, it was confirmed that there is in addition to Y ₂ O ₃ of Y ₂ SiO ₅ as a crystal structure.

[Comparative Example 2]
A phosphor composition precursor was prepared by the same constituent elements, composition, and method as in Example 1.
The phosphor precursor was centrifuged without washing with water, which is the method of the present invention, and dried at 150 ° C. to obtain 3.4 g of a powder sample.
The sample was then heat-treated in air at 1500 ° C. for 8 hours to obtain 2.5 g of a powder sample of the phosphor composition.
When the produced sample was irradiated with an ultraviolet lamp, green light emission was observed.
Next, the crystal structure of each powder sample by X-ray diffraction was evaluated.
The results are shown in FIG. 5 and FIG. The measurement conditions for X-ray diffraction in each figure are as follows.
Fig. 5: Measurement range 10-80 °, step width 0.05 °, counting time 2 seconds Fig. 6: Measurement range 27-30 °, step width 0.02 °, counting time 5 seconds

As a result of X-ray diffraction, the 150 ° C. dry powder showed an amorphous pattern, while the 1500 ° C. fired product showed a diffraction pattern consisting of a number of peaks indicating the presence of a crystalline phase as shown in FIG.
The diffraction pattern coincided with the diffraction pattern of Y ₂ SiO ₅ as shown in FIG.
On the other hand, the impurity phase as described in Example 1, a peak attributable to Y ₂ O ₃ in the 2 [Theta] = 29.16 ° is observed as shown in FIG. 6, in addition to Y ₂ O of Y ₂ SiO ₅ as a crystal structure ₃ was confirmed to exist.

Consideration about Examples 1-3 and Comparative Examples 1-2 When the phosphor composition precursor is synthesized, it is considered that ammonia and nitrate ions remain as residual components in the precursor. When the phosphor composition precursor containing the residual component is baked, it is considered that the Si component disappears due to the influence of the residual component, and the Y ₂ O ₃ phase is generated due to the lack of Si in the phosphor composition. Therefore, as shown in Example 1, the phosphor composition precursor is synthesized by the method of the present invention, and further, the residual component in the phosphor composition precursor is removed, so that a high-purity crystal structure is formed. It was found that the phosphor composition [1] or [5] can be obtained.

  As shown in Example 2, it was found that the phosphor composition [2] or [6] can also be obtained by the method of the present invention. .

  Further, the phosphor compositions [3], [4], [7], and [8] that can be synthesized by the methods of Example 1 and Example 2 also have a high-purity crystal structure by the method of the present invention. It is clear that a phosphor composition comprising:

  When the alkaline precipitant is dropped into the phosphor composition raw material solution as in Comparative Example 1, it is considered that a uniform phosphor composition precursor is not generated, and the phosphor composition precursor is washed with water. It is considered that the disappearance of the Si component cannot be suppressed. Therefore, in order to obtain a phosphor composition composed of a high-purity crystal structure, a method of dropping the phosphor composition raw material solution into an alkaline precipitant solution is preferable.

FIG. 2 is a powder X-ray diffraction pattern of 2θ = 10 ° to 80 ° of the phosphor composition obtained in Example 1. FIG. FIG. 2 is a powder X-ray diffraction pattern of 2θ = 27 ° to 30 ° of the phosphor composition obtained in Example 1. FIG. FIG. 2 is a powder X-ray diffraction pattern of 2θ = 10 ° to 80 ° of the phosphor composition obtained in Example 3. FIG. The powder X-ray-diffraction pattern of 2 (theta) = 26 degrees-30 degrees of the fluorescent substance composition obtained in Example 3. FIG. FIG. 2 is a powder X-ray diffraction pattern of 2θ = 10 ° to 80 ° of the phosphor composition obtained in Comparative Example 2. FIG. 2 is a powder X-ray diffraction pattern of 2θ = 27 ° to 30 ° of the phosphor composition obtained in Comparative Example 2. FIG.

Claims (14)

  The phosphor composition raw material in the phosphor composition raw material solution is dropped into the alkaline precipitant solution to precipitate the phosphor composition precursor, and the obtained phosphor composition precursor is washed with water, A method for producing a phosphor composition, comprising firing.   The method for producing a phosphor composition according to claim 1, wherein the phosphor composition precursor is washed with water until the pH of the washed water becomes 7-8.   The method for producing a phosphor composition according to claim 1 or 2, wherein when preparing the phosphor composition precursor, the phosphor composition raw material solution is dropped into an alkaline precipitant solution.   The phosphor composition raw material contains at least one element of at least one element selected from the group consisting of at least one alkaline earth element, at least one rare earth element, aluminum and silicon. Item 4. A method for producing a phosphor composition according to any one of Items 1 to 3.   The alkaline earth element compound is an alkaline earth element nitrate, chloride or sulfate, the rare earth element compound is a rare earth element nitrate, chloride or sulfate, and the aluminum compound is aluminum nitrate, aluminum chloride, It is aluminum sulfate or aluminum alkoxide, and the compound of silicon is tetraalkoxysilane or silica sol, The manufacturing method of the fluorescent substance composition in any one of Claims 1-4. The phosphor composition has the general formula [1]
(A ₂ O ₃ ) _x (B ₂ O ₃ ) _y (SiO ₂ ) _z [1]
(However, when x + y + z = 1, 0 <x <0.5, 0 <y <0.5, 0 <z <0.95, and A is at least one selected from Gd, Y, Lu and La. The element B represents at least one rare earth element other than A.)
The phosphor composition according to claim 1, comprising a crystalline material that emits light in the ultraviolet, visible, or infrared region by light stimulation, electron beam stimulation, or radiation stimulation. Manufacturing method. The method for producing a phosphor composition according to claim 6, wherein the crystalline crystal structure is the same type as that of Y ₂ SiO ₅ . The phosphor composition has the general formula [2]
(A ₂ O ₃ ) _a (B ₂ O ₃ ) _b (Al ₂ O ₃ ) _c [2]
(However, when a + b + c = 1, 0 <a <0.375, 0 <b <0.375, 0 <c <0.85, and A is at least one selected from Gd, Y, Lu and La. The element B represents at least one rare earth element other than A.)
The phosphor composition according to claim 1, comprising a crystalline substance that emits light in the ultraviolet, visible, or infrared region by light stimulation, electron beam stimulation, and radiation stimulation. Manufacturing method. The method for producing a phosphor composition according to claim 8, wherein the crystalline crystal structure is the same type as that of Y ₃ Al ₅ O ₁₂ . The phosphor composition has the general formula [3]
(QO) _d (BO) _e (RO) _f (SiO _z ) _g [3]
(However, when d + e + f + g = 1, 0 <d <0.25, 0 <e <0.25, 0 <f <0.4, 0 <g <0.95, and B is selected from rare earth elements. (At least one element, Q represents at least one element selected from Mg, Ca, Sr, Ba and Ra, and R represents at least one alkaline earth element other than Q.)
The phosphor composition according to claim 1, comprising a crystalline material that emits light in the ultraviolet, visible, or infrared region by light stimulation, electron beam stimulation, or radiation stimulation. Production method. The method for producing a phosphor composition according to claim 10, wherein the crystalline crystal structure is the same type as CaMgSi ₂ O ₆ . The phosphor composition has the general formula [4].
(QO) _h (BO) _i (RO) _k (Al ₂ O ₃ ) _m [4]
(However, when h + i + k + m = 1, 0 <h <0.143, 0 <i <0.143, 0 <k <0.3, 0 <m <0.95, and B is selected from rare earth elements. (At least one element, Q represents at least one element selected from Mg, Ca, Sr, Ba and Ra, and R represents at least one alkaline earth element other than Q.)
The phosphor composition according to claim 1, comprising a crystalline material that emits light in the ultraviolet, visible, or infrared region by light stimulation, electron beam stimulation, or radiation stimulation. Production method. The method for producing a phosphor composition according to claim 12, wherein the crystalline crystal structure is the same type as that of BaMgAl ₁₀ O ₁₇ .   The fluorescent substance composition manufactured by the manufacturing method of the fluorescent substance composition in any one of Claims 1-13.

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