JP6545055B2 - Method of manufacturing phosphor - Google Patents

Description

The present invention relates to a method for producing a phosphor that emits red light efficiently when excited by blue light.

In Patent Document 1, as a red phosphor, A ₂ [MF ₆ ]: Mn ^{4 +} (element A is Li, Na, K, Rb, Cs, NH ₄ or the like, element M is Ge, Si, Sn, Ti, A phosphor represented by the formula of Zr etc. is disclosed.

In Patent Document 1, as a method for producing the phosphor, an A ₂ [MF ₆ ] crystal serving as a matrix of the phosphor and a K ₂ MnF ₆ crystal containing Mn serving as a light emission center are contained in hydrofluoric acid. Disclosed is a manufacturing method in which a solution produced by dissolution and attached to the manufactured phosphor is evaporated and then dried.

In the said manufacturing method, in order to evaporate hydrofluoric acid, the reactor excellent in heat resistance and corrosion resistance, and the installation which excludes the harmful | toxic hydrogen fluoride gas generate | occur | produced with evaporation were required.

Patent Document 2 discloses a poor solvent method as one of the methods for producing an A ₂ MF ₆ : Mn phosphor which does not require the evaporation of hydrofluoric acid at high risk. However, in the said manufacturing method, while the uniformity of the particle size of the manufactured fluorescent substance is low, in order to obtain a desired particle size, the subject that control is difficult occurs.
In the method for producing phosphors of Patent Documents 3 to 5, it is difficult to control the particle diameter in a state where the produced phosphors have sufficient emission characteristics.

Japanese Patent Publication 2009-528429 U.S. Pat. No. 3,576,756 Unexamined-Japanese-Patent No. 2010-209311 JP 2012-224536 A JP, 2015-044971, A

In the manufacturing method for producing a phosphor represented by the general formula: A ₂ MF ₆ : Mn, the present inventors previously add particles serving as a crystal growth starting point before the phosphor deposition reaction, and select them. The present invention has been accomplished by finding a manufacturing method capable of controlling the particle size in a wide range while maintaining good fluorescence characteristics by growing the crystals.

The present invention is a method for producing a phosphor for producing a phosphor represented by the general formula A ₂ MF ₆ : Mn, wherein the element A is an alkali metal element, and the element M is Si, Ge, Sn, Ti, A solution producing step of producing a hydrofluoric acid solution in which element A, element M and Mn are dissolved in hydrofluoric acid, which is one or more tetravalent metal elements selected from Zr and Hf; A suspension producing step of producing a suspension by adding at least one of A ₂ MF ₆ : Mn particles and A ₂ MF ₆ particles as seed crystals, and a phase compatible with hydrofluoric acid in the suspension surface in formula a ₂ MF solutions were mixed with the seed crystal 6: is a manufacturing method of the phosphor having a precipitation step of precipitating _Mn.

As a phase solution in the precipitation step, one or more liquids selected from water, methanol, ethanol, isopropanol and acetone are preferable.

The seed crystal concentration in the suspension produced in the above-mentioned suspension production step is preferably 0.01 mol / kg or more and 0.2 mol / kg or less.

As for the average particle diameter of the seed crystal added at the said suspension manufacturing process, 8 micrometers or more and 35 micrometers or less are preferable.

According to the method for producing a phosphor of the present invention, the phosphor represented by the general formula: A ₂ MF ₆ : Mn is stabilized while controlling the particle diameter of the phosphor while maintaining the internal quantum efficiency at a certain level. Can be manufactured. More specifically, when depositing a phosphor represented by A ₂ MF ₆ : Mn in a solution, the amount and size of seed crystals are adjusted in the process of adding seed crystals as nuclei of crystal growth. To obtain a phosphor having an average particle size of 10 to 40 μm.

FIG. 1 is a flow diagram showing an overview of the present invention. The figure which shows the X-ray-diffraction pattern of the fluorescent substance obtained by the reference example. The figure which shows the scanning electron micrograph of the fluorescent substance obtained by the reference example. The figure which shows the excitation * fluorescence spectrum of the fluorescent substance obtained by the reference example. The figure which shows the scanning electron micrograph of the fluorescent substance obtained in Examples 1-4.

The present invention is a method for producing a phosphor represented by the general formula: A ₂ MF ₆ : Mn.
The element A in the general formula is an alkali metal element, preferably one or more elements selected from Na (sodium), K (potassium) and Rb (rubidium).
The element M in the general formula is one or more metal elements selected from Si (silicon), Ge (germanium), Sn (tin), Ti (titanium), Zr (zirconium) and Hf (hafnium), and Si, Ge and Ti are preferable in terms of chemical stability. The fluorescence properties of the phosphor according to the present invention are influenced by the type of element M.
F is fluorine. Mn is manganese and is a luminescent center substance of a phosphor.

Manufacturing method of the phosphor of the present invention, as shown in FIG. 1, a solution manufacturing process elements A, element M and Mn to produce a solution obtained by melting the hydrofluoric acid which is a raw material, A ₂ to the solution MF ₆ : A suspension manufacturing step of adding at least one of Mn particles and A ₂ MF ₆ particles as seed crystals and mixing them to produce a suspension, and a precipitation step of precipitating phosphors from the suspension Have. After the precipitation step, as a post-treatment step, the phosphor after the precipitation step can be subjected to a washing step, a solid content separation step, and a drying step.

Solution manufacturing process
The solution production process is a solution production process for producing a hydrofluoric acid solution in which element A, element M and Mn are dissolved in hydrofluoric acid, element A is an alkali metal element, and element M is Si, Ge At least one tetravalent metal element selected from Sn, Ti, Zr and Hf.
The higher the concentration of hydrogen fluoride in hydrofluoric acid in the solution production process, the higher the concentration of the source elements can be dissolved, and the phosphor can be deposited with high productivity, but if it is too high, the vapor pressure becomes high. The risk of handling increases. If the concentration of hydrogen fluoride is too low, the amount of dissolution of the raw material element will be low, and the yield will be lowered. Therefore, the hydrogen fluoride concentration is preferably 40% by mass to 70% by mass.

Element A, M and M as raw materials are the same compounds as phosphors (including those not containing Mn), or a plurality of phosphors which can be dissolved in hydrofluoric acid and react with each other. There is a compound.
The latter compounds include element A fluorides, hydrogen fluoride salts, nitrates, carbonates, acetates, chlorides, etc., oxides of element M, and hydrogen fluoride compounds.
As a raw material of Mn, K ₂ MnF ₆ is preferable because it is dissolved in hydrofluoric acid and present as Mn ^{4 +} in the phosphor.
The composition of the element of the raw material is selected according to the composition ratio of the phosphor to be obtained, and in fact, since the ease of precipitation from the solution differs depending on the type of the constituent element, the difference between the preparation composition and the synthetic powder composition Will occur.
For example, the Mn / Si ratio of a product obtained by dissolving K ₂ SiF ₆ powder and K ₂ MnF ₆ powder in hydrofluoric acid and mixing a poor solvent as the raw materials is more than the Mn / Si of the raw materials It becomes smaller. In this case, the raw material K ₂ MnF ₆ powder is added in excess in order to obtain the target Mn amount in the synthetic powder.
The composition of the raw material should be adjusted as appropriate according to the target composition.

<Suspension manufacturing process>
In the suspension production step, at least one of A ₂ MF ₆ : Mn particles and A ₂ MF ₆ particles is added as a seed crystal to a hydrofluoric acid solution in which A, M and Mn are dissolved in hydrofluoric acid To produce a suspension.
The seed crystals are dissolved to a saturated state when added to the solution, and the undissolved residue becomes the nucleus of the phosphor to be manufactured.

<Seed crystal>
The reason why at least one of the A ₂ MF ₆ : Mn particles and the A ₂ MF ₆ particles is added as a seed crystal is as follows.
Precipitation of the phosphor from the solution is caused by nucleation of crystals from the solution as well as being made on the surface of the added seed crystals. If the seed crystal is large, it tends to obtain a large phosphor, and if the seed crystal is small, it tends to obtain a small phosphor. When the number of seed crystals is large, precipitates tend to be allocated to a large number of seed crystals, which tends to give small phosphors. When the number of seed crystals is small, the amount of precipitation per unit seed crystal increases, and a large phosphor tends to be obtained.

Particle size control of the phosphor is possible by adjusting the size and number of seed crystals. When applied to a white LED, the particle size of the phosphor is 10 μm to 40 μm in average, and in order to obtain a phosphor in this range, the average particle size of the seed crystal is preferably 8 μm to 35 μm.

If the amount of the seed crystal added is too small, crystal nucleation will occur in addition to the seed crystal in the precipitation step and particle size control tends to be difficult, and if too large, the precipitation amount / seed crystal ratio in the phosphor becomes extremely low. Productivity tends to decrease. It is preferable to adjust the seed crystal addition amount so that the seed crystal concentration in the said hydrofluoric acid solution will be 0.01 mol / kg or more and 0.2 mol / kg or less. The seed crystal concentration is the number of moles of seed crystals per unit mass of suspension.

When the hydrofluoric acid solution is a saturated solution, the particle size and amount of the powder added as seed crystals directly correspond to the size and number of seed crystals in the suspension, but in the case of non-saturation, some of them are In order to dissolve, it is necessary to consider the dissolved content. If the solute concentration of the hydrofluoric acid solution is low, the amount of dissolution of the powder added as seed crystals becomes extremely large and it becomes difficult to control, so it is preferable to increase the solute concentration of the hydrofluoric acid solution.

The shape of the seed crystal includes single particles and agglomerated particles in which the single particles are agglomerated, and single particles are preferable to agglomerated particles. The reason that aggregated particles are not preferable is that the aggregated particles added to the hydrofluoric acid solution lose their aggregation, and the particle diameter of the added seed crystals and the particles of the seed crystal particles actually dispersed in the hydrofluoric acid solution This is because there is a divergence between the diameter and the difficulty of particle size control. Agglomerated particles are also undesirable because, upon grain growth, there is a complex shape due to the growth of each particle.

The elements A and M of the A ₂ MF ₆ : Mn particles and A ₂ MF ₆ particles in the seed crystal may not be the same as the elements in the hydrofluoric acid solution in terms of the design of the phosphor.

<Deposition process>
The precipitation step is a step of precipitating the general formula A ₂ MF ₆ : Mn on the seed crystals by mixing the suspension produced by the suspension production step with a liquid compatible with hydrofluoric acid. .

The precipitation step is a step of precipitating the phosphor by reducing the saturated solubility of A ₂ MF ₆ : Mn in the solvent by mixing the liquids. The liquid to be mixed is a liquid having a function of reducing the saturation solubility of A ₂ MF ₆ : Mn in a solvent, and specifically, a liquid or two or more kinds selected from water, methanol, ethanol, isopropanol and acetone Water is preferable from the viewpoint of ease of handling and safety.

<Post-processing process>
A ₂ MF 6 of the phosphor obtained in the precipitation step: _Mn as post-processing, cleaning process to the phosphor after the deposition process, may be provided solids separation step, a drying step.

The washing step is a step of separating the liquid and phosphor after the precipitation step into the liquid and the phosphor by a method such as filtration, centrifugation, decantation and the like, and then washing with an organic solvent such as methanol, ethanol, acetone or the like.
In the washing step, when the phosphor is washed with water, a part of the phosphor is hydrolyzed to form a brown manganese compound, and the properties of the phosphor are degraded. The reason for using an organic solvent is to prevent it from being generated.
In the washing step, if washing is performed several times with hydrofluoric acid before washing with an organic solvent, impurities generated in a small amount can be dissolved and removed more effectively. The concentration of hydrofluoric acid in this case is preferably 5% by mass or more from the viewpoint of suppressing the hydrolysis of the fluoride phosphor.

The solid content separation step is a step of separating the phosphor after the washing step and the washing solution, which is performed, for example, by filtration.

The drying step is a step of completely evaporating the cleaning solution remaining and adhering to the phosphor.
After the drying step, in order to make the particle size of the phosphor uniform and adjust the maximum particle size, it is preferable to perform classification of the phosphor. Specifically, there is a method of classifying a classification process into one that has passed a sieve and one that has not.

Examples will be described in detail using tables and figures while comparing them with reference examples. Table 1 shows the production conditions of Examples and Reference Examples and the evaluation results of the manufactured phosphors, and Table 2 shows the characteristic values of the seed crystals used in the Examples. The seed crystals No1 to No4 are all prototypes manufactured by Denki Kagaku Kogyo Co., Ltd.

(Reference example)
A method of producing a phosphor of the general formula A ₂ MF ₆ : Mn as a reference example will be described. In this phosphor, K was used as the element A, and Si was used as the element M. The manufacturing methods of the reference examples and the examples were all performed at an ambient temperature of 23 ° C., except for the steps that particularly referred to the temperature.

The method of manufacturing the phosphor of the reference example is a conventional manufacturing method, and K ₂ SiF ₆ (manufactured by Morita Chemical Co., Ltd., purity 98% or more) and K ₂ MnF ₆ were used as the raw materials of the phosphor. Both are powdery. It will be described the manufacturing process of K ₂ MnF _6.

<Manufacturing process of K ₂ MnF ₆ >
In a 1-liter Teflon (registered trademark) beaker, 800 ml of 40 mass% hydrofluoric acid was placed, 260 g of powdered KHF ₂ (Wako Pure Chemical Industries, Ltd., special grade reagent) and potassium permanganate powder ( 12 g of Wako Pure Chemical Industries, Ltd., reagent grade 1) was dissolved.
While stirring this hydrofluoric acid reaction solution with a magnetic stirrer, 8 ml of 30% hydrogen peroxide water (manufactured by Wako Pure Chemical Industries, Ltd., special grade reagent) was dropped little by little.

When the amount of the hydrogen peroxide solution dropped exceeds a certain amount, yellow particles began to precipitate, and the color of the reaction liquid began to change from purple. After a predetermined amount of hydrogen peroxide solution was dropped, stirring was continued for a while, and then stirring was stopped to precipitate precipitated particles.

<Cleaning step of K ₂ MnF ₆ >
After precipitation, the supernatant was removed, methanol was added, and the mixture was stirred and allowed to stand. The supernatant was removed and methanol was further added. This operation was repeated until the solution became neutral.
Thereafter, the precipitated particles were recovered by filtration and further dried to remove methanol completely by evaporation to obtain 19 g of powdered K ₂ MnF ₆ .

<Production process of phosphor>
In a beaker made of Teflon (registered trademark) having a capacity of 3000 ml, 1000 ml of 55% by mass hydrofluoric acid is placed, and 30 g of powdered K ₂ SiF ₆ (Morita Chemical Co., Ltd., purity 98% or more) and the above K ₂ MnF 5 g of ₆ was added and dissolved by sufficiently stirring.

While stirring the hydrofluoric acid aqueous solution, 1500 ml of distilled water was poured in with a beaker in about 1 minute. It was visually confirmed that a yellow powder was generated in the reaction solution by the addition of distilled water.

<Washing process of phosphor>
After the entire amount of distilled water was charged, the mixture was further stirred for 20 minutes and then allowed to stand to precipitate solid content. After confirmation of precipitation, the supernatant is removed, washing is performed with 20% by mass of hydrofluoric acid and methanol, the solid portion is separated and recovered by filtration, and the remaining methanol is further evaporated and removed by drying, to obtain phosphor powder I got

The dried phosphors were limited to those having passed through a nylon screen of 75 μm mesh.
Through the above steps, K ₂ SiF ₆ : Mn as a phosphor was obtained.

A method of crystal phase evaluation, particle size distribution measurement, scanning electron microscope observation, and fluorescence characteristic (excitation and fluorescence spectrum, quantum efficiency) evaluation of the phosphor shown in Table 1 will be described.

<Crystal phase>
The crystal phase of the phosphor was measured by an X-ray diffraction pattern using an X-ray diffractometer (Ultima IV manufactured by Rigaku Corporation). For the measurement, a CuKα tube was used. The X-ray diffraction pattern of the phosphor obtained by the manufacturing method of the reference example is shown in FIG. From the X-ray diffraction pattern, it was single with the K ₂ SiF ₆ crystal.

<Particle size distribution>
The particle size distribution of the phosphor was measured by a laser diffraction scattering type particle size distribution measuring apparatus (LC 13 320 manufactured by Beckman Coulter, Inc.). Ethanol was used as a measurement solvent. From the cumulative particle size distribution curve obtained, 10% by volume diameter (D10), 50% by volume diameter (D50) and 90% by volume diameter (D90) were determined. The average particle diameter of the phosphor obtained by the manufacturing method of the reference example was 30.3 μm. The mean particle size in this case means D50.
The acceptance value of the average particle diameter (D50) of the said fluorescent substance was 10-40 micrometers, and the fluorescent substance of the reference example was 30.3 micrometers.

<Particle form of phosphor>
The particle morphology of the phosphor was not shown in Table 1, but was measured by a scanning electron microscope (JSM-7001F SHL manufactured by JEOL Ltd.). A scanning electron micrograph of the phosphor of the reference example is shown in FIG.

<Excitation and fluorescence spectrum>
The excitation and fluorescence spectrum of the phosphor of the reference example measured by a spectrofluorimeter (F-7000 manufactured by Hitachi High-Technologies Corporation) is shown in FIG.
The excitation wavelength of the fluorescence spectrum in this measurement is 455 nm, and the monitor fluorescence wavelength of the excitation spectrum is 632 nm. This phosphor was a phosphor having two excitation bands of ultraviolet light in the vicinity of a peak wavelength of 350 nm and blue light in the vicinity of a peak wavelength of 450 nm, and having a plurality of narrow band emission in the red region of 600 nm to 700 nm.

<Fluorescent measurement>
The fluorescence measurement shown in Table 1 was evaluated at normal temperature by the following method.
A standard reflector (Spectralon manufactured by Labsphere, Inc.) having a reflectance of 99% was set in the side opening (φ 10 mm) of the integrating sphere (φ 60 mm). A monochromatic light split to a wavelength of 455 nm from a light emitting light source (Xe lamp) was introduced to this integrating sphere by an optical fiber, and the spectrum of the reflected light was measured by a spectrophotometer (MCPD-7000 manufactured by Otsuka Electronics Co., Ltd.). At that time, the excitation light photon number (Q _ex ) was calculated from the spectrum in the wavelength range of 450 to 465 nm. Next, a concave cell filled with a fluorescent substance so as to have a smooth surface is set at the opening of the integrating sphere, and monochromatic light of wavelength 455 nm is irradiated, and the spectrum of the reflected light and fluorescence of the excitation is spectrophotometric It measured by the meter.
The excitation reflected light photon number (Q _ref ) and the fluorescence photon number (Q _em ) were calculated from the obtained spectrum data.
The number of excitation reflected light photons was calculated in the same wavelength range as the number of excitation light photons, and the number of fluorescence photons was calculated in the range of 465 to 800 nm.
From the three photon numbers obtained, the external quantum efficiency (= Q _em / Q _ex × 100), the absorptivity (= (Q _ex −Qr _ef ) × 100), the internal quantum efficiency (= Q _em / (Q _ex −) Q _ref ) × 100) was determined.
The absorptivity, internal quantum efficiency, and external quantum efficiency of the phosphor of the reference example were 76.5%, 80.1%, and 61.2%, respectively.
The pass value at internal quantum efficiency is 75% or more.

The spectrum measured by setting the phosphor of the reference example is measured according to JIS Z 8724 (color measurement method-light source color-) according to the calculation method in the XYZ color specification system defined in JIS Z 8701. The chromaticity coordinates (x, y) were calculated using a color function. The wavelength range used for chromaticity coordinate calculation was set to 465 to 780 nm. The chromaticity coordinates (x, y) of the reference example were (0.693, 0.306).

<Seed crystal>
Table 2 shows data of K ₂ SiF ₆ : Mn as a seed crystal used in the examples. The Mn content is a value measured by ICP (Inductively Coupled Plasma) method.

The method for producing the phosphor of Example 1 is a method for producing the general formula A ₂ MF ₆ : Mn, the element A is K, and the element M is Si.

<Manufacturing process>
In a beaker made of Teflon (registered trademark) having a volume of 2000 ml, 500 ml of 55% by mass hydrofluoric acid is placed, and 30 g of K ₂ SiF ₆ powder (Morita Chemical Co., Ltd., purity 98% or more) and seed crystal 1 of Table 1 2.5 g of K ₂ MnF ₆ was added and thoroughly stirred to prepare a hydrofluoric acid solution.
To this hydrofluoric acid solution was added 20 g of K ₂ SiF ₆ : Mn of seed crystal No. 1 in Table 2 (seed crystal concentration in suspension was 0.14 mol / kg), and stirring was carried out for a while, Example A suspension of 1 was prepared.
While stirring this solution, 750 ml of distilled water was poured in with a beaker in about 1 minute. After adding the whole amount of distilled water, it was stirred for 30 minutes and then allowed to stand to precipitate solid content.

<Post-processing process>
After confirmation of precipitation, the supernatant was removed, washed with 20% by mass hydrofluoric acid, and then washed with methanol, and the solid portion was separated and collected by filtration, and the remaining methanol was evaporated and removed by drying treatment.
The dried phosphors were classified into only those which were passed through a nylon sieve having an opening of 75 μm, to obtain K ₂ SiF ₆ : Mn phosphor powder of Example 1. The recovered amount of the obtained phosphor was 38.4 g.

When X-ray diffraction measurement was performed on the phosphor of Example 1, the crystal phase was K ₂ SiF ₆ single phase. The excitation and fluorescence spectra had the same shape as the reference example shown in FIG. A scanning electron micrograph of the phosphor of Example 1 is shown in FIG. 5 (A).

Examples 2 and 3 are the same production method as Example 1 except that the seed crystals are changed. Scanning electron micrographs of the phosphors of Examples 2 and 3 are shown in FIGS. 5 (B) and (C).
As shown in Table 1, the particle size of the obtained phosphor changed according to the particle size of the added seed crystals. As can be seen from the scanning electron micrograph of FIG. 5, since the phosphor particles are almost single particles and the size distribution is also small, it is possible that the added seed crystals become nuclei and selective growth proceeds It is guessed.

The internal quantum efficiency of each of the phosphors of Examples 1 to 3 was 80% or more, and regardless of the type of the seed crystal, it was a phosphor of high internal quantum efficiency.
The rate of absorption increased with increasing particle size.
The chromaticity was almost the same because there was no difference in the shape of the fluorescence spectrum.
The size of the seed crystal allows the particle size to be controlled while maintaining the high quantum efficiency of the phosphor.

Example 4
The seed crystal used in Example 3 was used for the method of manufacturing the phosphor of Example 4. The production method is the same as in Example 3 except that the amount of the seed crystals added is 5 g (the concentration of seed crystals in the suspension is 0.036 mol / kg).
The phosphor obtained by the method for producing a phosphor of Example 4 is 23 g, is a K ₂ SiF ₆ crystal single phase, the average particle diameter is 28.2 μm, the absorptivity by blue light excitation at 455 nm, the internal quantum efficiency The external quantum efficiencies were 73.8%, 85.2% and 62.9%, respectively, and the chromaticity coordinates (x, y) were (0.688, 0.307). The excitation and fluorescence spectrum had the same shape as the reference example (FIG. 4).
The scanning electron micrograph of the phosphor of Example 4 is shown in FIG. 5 (D). Since the phosphor particles of Example 4 are almost single particles and the size distribution is also small, it is inferred that the added seed crystals become nuclei and selective growth proceeds.
By adjusting the addition amount of the seed crystals, it was possible to control the particle size while maintaining the high quantum efficiency of the phosphor.

Example 5
The method of producing the phosphor of Example 5 is the same as that of Example 4 except that a K ₂ SiF ₆ powder containing no Mn and having the same particle diameter as that used in Example 3 is used as a seed crystal.
The phosphor obtained by the method for producing a phosphor of Example 5 is 23 g, is a K ₂ SiF ₆ crystal single phase, has an average particle diameter of 28.6 μm, an absorptivity at blue light excitation of 455 nm, an internal quantum efficiency The external quantum efficiencies were 68.5%, 83.8% and 57.4%, respectively, and the chromaticity coordinates (x, y) were (0.690, 0.306).
Even as K ₂ SiF ₆ not containing Mn as a raw material, it could be used as a seed crystal for controlling the particle size of the phosphor.

Other Embodiments
Other examples not described in Table 1 will be described.
When K as element A in Example 1 is Na, the same effect as Example 1 is exhibited.
The raw materials as element A in Example 1 are fluoride of element A, hydrogen fluoride salt of element A, nitrate of element A, carbonate of element A, acetate of element A, chloride solution of element A, and the like When it did, it showed the same effect as execution example 1.
When element A in Example 1 is Na, Rb, K and Na, K and Rb, Na and Rb, K, Na and Rb, respectively The same effect as in Example 1 was exhibited.
When the element M in Example 1 is Ge, Sn, Ti, Zr, Hf, Si and Ge, Si and Sn, Si and Sn In the case of Ti, in the case of Si and Zr, in the case of Si and Hf, in the case of Ge and Sn, in the case of Ge and Ti, in the case of Ge and Zr, in the case of Ge and Hf, Sn and Ti In the case of Sn and Zr, the case of Sn and Hf, the case of Ti and Zr, the case of Ti and Hf, the case of Zr and Hf, the case of Si, Ge and Sn, Si, When used as Ge and Ti, when used as Si, Ge and Zr, when used as Si, Ge and Hf, when used as Si, Sn and Ti, when used as Si, Sn and Zr, used as Si, Sn and Hf In the case of Si, Ti and Zr, Si, Ti and Hf, Si, Zr and Hf, Si, Ge, Sn and Ti, Si, Ge, Sn and Zr , Si, Ge, Sn and Hf, Si, Ge, Ti and Zr, Si, Ge, Ti and Hf, Si, Ge, Zr and Hf, Si, Ge and Ti Although the fluorescence characteristics were superior when one was used, it was possible to control the average particle diameter in the range of 10 to 40 μm as an example.

Claims (4)

A method of producing a phosphor for producing a phosphor represented by the general formula A ₂ MF ₆ : Mn, wherein the element A is an alkali metal element, the element M is from Si, Ge, Sn, Ti, Zr and Hf One or more tetravalent metal elements to be selected, F is fluorine, Mn is manganese,
A solution manufacturing step of manufacturing a hydrofluoric acid solution in which element A, element M and Mn are dissolved in hydrofluoric acid;
A suspension producing step of producing a suspension by mixing the solution with at least one of A ₂ MF ₆ : Mn particles and A ₂ MF ₆ particles as seed crystals;
A method for producing a phosphor, comprising a precipitation step of mixing a phase solution compatible with hydrofluoric acid with the suspension to precipitate the general formula A ₂ MF ₆ : Mn on the surface of the seed crystal. The method for producing a phosphor according to claim 1, wherein the phase solution in the precipitation step is one or more liquids selected from water, methanol, ethanol, isopropanol and acetone. The method for producing a phosphor according to claim 1 or 2, wherein a seed crystal concentration in the suspension produced in the suspension production step is 0.01 mol / kg or more and 0.2 mol / kg or less. The method for producing a phosphor according to any one of claims 1 to 3, wherein an average particle diameter of seed crystals added in the suspension production step is 8 μm or more and 35 μm or less.