TWI627261B - Method for producing complex fluoride phosphor - Google Patents

Abstract

About Formula (I) A ₂ MF ₆ : Mn (I)

(M is one or two or more kinds of tetravalent elements selected from Si, Ti, Zr, Hf, Ge, and Sn, and A is selected from Li, Na, K, Rb, and Cs, and contains at least Na and/or Or one or more alkali metals of K)

In the production of the Mn-activated complex fluoride red phosphor, the M-containing compound and the A-containing compound and the Mn-containing compound, the M-containing compound, the A-containing Mn compound, the M-containing compound, and the Mn-containing compound are used as a raw material. a compound or a compound containing A and Mn and a compound containing M and A, and mixing the above-mentioned raw materials in a reaction tank in a liquid containing hydrogen fluoride or a salt thereof to form a double fluoride phosphor of A ₂ MF ₆ : Mn In the case of crystallization, a method for producing a complex fluoride phosphor containing Mn ⁴⁺ as a main component and further containing 0.5 to 10 at% of Mn ²⁺ and/or Mn ³⁺ in the above-mentioned raw material can be prevented according to the present invention. The oxidation of Mn ⁴⁺ produces a high performance red phosphor.

Description

Method for producing complex fluoride phosphor

The present invention relates to a formula A ₂ MF ₆ : Mn which can be used as a red fluoride phosphor for blue LEDs (wherein M is one or two selected from Si, Ti, Zr, Hf, Ge and Sn) The above tetravalent element, A is an alkali metal selected from Li, Na, K, Rb, and Cs and containing at least one or two or more alkali metals of Na and/or K.) A method of producing a red phosphor (polyfluoride phosphor).

In order to enhance the color reproducibility of a white LED (Light Emitting Diode) or to use a white LED as a backlight of a liquid crystal display, it is necessary to emit red light by exciting light of an LED equivalent to near ultraviolet to blue. The phosphor is undergoing research. In the above-mentioned Japanese Patent Publication No. 2009-528429 (Patent Document 1), it is described in the formula of A ₂ MF ₆ (A is Na, K, Rb, etc., M is Si, Ge, Ti, etc.). It is useful to add Mn (polyfluoride phosphor) to fluoride.

In the method for producing a phosphor described above, Patent Document 1 discloses that a hydrofluoric acid solution in which all the constituent elements are dissolved or dispersed is evaporated. The method of precipitation after shrinking. As a separate production method, in the specification of the U.S. Patent No. 3,576,756 (Patent Document 2), a method in which a solvent of a hydrofluoric acid in which each element is dissolved is mixed, and acetone in a water-soluble organic solvent is added to lower the solubility and precipitate is disclosed. Further, in the patent No. 4,582,259 (Patent Document 3) and JP-A-2012-224536 (Patent Document 4), it is disclosed that the element M and the element A in the above formula are respectively dissolved in respective hydrogen fluorides. The acid solution is mixed again with any method in which Mn has been added to precipitate the phosphor.

In this case, in the Mn-activated complex fluoride red phosphor (polyfluoride phosphor), Mn must be tetravalent Mn, and Mn ⁴⁺ is a luminescent center, and Mn in divalent, trivalent Mn or hexavalent, etc. Although it is not a luminescent center of a red phosphor, in the conventional manufacturing method of A ₂ MF ₆ : Mn, the oxidation of Mn ⁴⁺ in production is not fully considered.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for producing a complex fluoride phosphor which can provide a high-performance red phosphor without oxidizing Mn ⁴⁺ .

As a result of an effort to achieve the above object, the inventors of the present invention found that A ₂ MF ₆ :Mn is crystallized by oxidizing Mn ⁴⁺ of the luminescent center of the A ₂ MF ₆ :Mn phosphor. The Mn ion having a small number of valences can prevent oxidation of Mn ^{4+ which} is generated in the reaction step, and a high-performance red phosphor can be produced, and the present invention has been completed.

Accordingly, the present invention provides a method of producing a polyfluoride phosphor as described below.

[1] A method for producing a complex fluoride phosphor, which is characterized by the following formula (I) A ₂ MF ₆ : Mn (I)

(wherein M is one or two or more kinds of tetravalent elements selected from Si, Ti, Zr, Hf, Ge, and Sn, and A is selected from Li, Na, K, Rb, and Cs, and is at least One or more alkali metals containing Na and/or K)

In the production of the Mn-activated complex fluoride red phosphor, a compound containing M and a compound containing A and a compound containing Mn, a compound containing M, a compound containing A and Mn, and M and A are used as a raw material. The compound and the compound containing Mn, or the compound containing A and Mn, and the compound containing M and A, and the above-mentioned raw materials are mixed in a reaction tank in a liquid containing hydrogen fluoride or a salt thereof to obtain A ₂ MF ₆ : When the Mn complex fluoride phosphor is crystallized, Mn ^{4+ is} mainly contained in the above-mentioned raw material, and further 0.5 to 10 at% of Mn ²⁺ and/or Mn ^{3+ is} contained.

[2] The production method according to [1], wherein water is prepared in a container, and hydrogen fluoride is introduced therein, and then a compound containing M (however, M is as described above) is introduced, stirred, dissolved, and then charged with A ( However, the compound of A with the above) and the compound containing Mn or the compound containing A (but A with the above) and Mn are stirred and dissolved to prepare a matrix solution, and finally, the matrix solution is stirred while adding A (however, a with the above) is added with dissolved fluoride or hydrofluoric acid solution of the agent is fluoride formed in the matrix solution to a a ₂ MF _6: Mn (however, when a and M are the same above) crystallization, consisting of The raw material composed of the Mn-containing compound or the above-mentioned compound containing A and Mn contains Mn ⁴⁺ as a main component and 0.5 to 10 at% of Mn ²⁺ and/or Mn ³⁺ .

[3] The production method according to [1] or [2] wherein at least the crystallization reaction is carried out in an inert gas atmosphere.

[4] The production method according to any one of [1] to [3] wherein the liquid for crystallization of A ₂ MF ₆ : Mn is subjected to a crystallization reaction while being purged with an inert gas.

[5] The production method according to any one of [1] to [4] wherein the activated Mn ion in the red phosphor represented by A ₂ MF ₆ : Mn (however, A and M are the same as above) The content is 0.2 to 1.2 at% of the entire phosphor.

According to the present invention, it is possible to prevent Mn ions having a small number of valences in a solution without oxidizing Mn ⁴⁺ of the luminescent center of the A ₂ MF ₆ :Mn phosphor, by the presence of Mn ions having a small valence. The oxidation of Mn ⁴⁺ produces a high performance red phosphor. Further, by removing oxygen from the ambient atmosphere in a specific step of the manufacturing process to prevent oxidation of Mn ⁴⁺ , a high-performance red phosphor can be produced. Further, the production method of the present invention is an excellent production method which can be gradually added to a raw material in one reaction vessel and can be carried out in a rational and highly productive manufacturing facility.

1‧‧‧ container

2‧‧‧Agitating mechanism

3,7,9‧‧‧with door fittings

4‧‧‧ pump

5‧‧‧ supply slot

6‧‧‧Powder supply device

8‧‧‧Drip tank

Fig. 1 is a schematic view showing an example of a manufacturing apparatus used for carrying out the production method of the present invention.

The production method of the present invention is to obtain the following formula (I) A ₂ MF ₆ : Mn (I)

(wherein M is one or two or more kinds of tetravalent elements selected from Si, Ti, Zr, Hf, Ge, and Sn, and A is selected from Li, Na, K, Rb, and Cs, and is at least One or two or more alkali metals containing Na and/or K.)

A method of forming a complex fluoride phosphor.

Here, M is preferably Si, Ti or Ge, especially Si or Ti, and A is preferably Na or K.

In the present invention, a compound containing M and a compound containing A and a compound containing Mn, a compound containing M and a compound containing A and Mn, a compound containing M and A, a compound containing Mn, or a compound containing A and Mn are used. The compound and the compound containing M and A are mixed in a reaction bath with a compound containing a hydrogen fluoride or a salt thereof to crystallize the A ₂ MF ₆ :Mn polyfluoride phosphor.

In this case, the method of producing A ₂ MF ₆ : Mn may be any method which is carried out in a wet manner by using the above compound, but the components obtained as raw materials are sequentially dissolved in water, for example, and the resulting aqueous solution is finally made. The method of precipitating the red phosphor of the formula (I) is preferred.

At this time, as the raw material, an M source (a tetravalent element source), an A source (alkali metal source), a Mn source, a fluorine source, and further a hydrogen fluoride as a reaction medium are used. These materials are dissolved in water to cause a reaction to obtain a precipitate of a phosphor. Although the order of dissolution is not limited, it is preferred to add the alkali metal A after all the other materials have been dissolved. Further, in order to make it easy to dissolve, it is preferred to add hydrogen fluoride to the M source and the Mn source.

In particular, it includes a first solution each containing a fluoride containing a tetravalent element M, and a fluoride containing a alkali metal A, a hydrogen fluoride salt, a nitrate, a sulfate, a hydrogen sulfate, a carbonate, a hydrogencarbonate, and a hydroxide. a step of mixing the second solution of the selected compound and/or the solid of the compound of the alkali metal A, mixing the first solution with the second solution and/or solid, and mixing the fluoride of the tetravalent element M with the alkali metal A The step of reacting the compound and the step of recovering the solid product formed by the reaction and solid-liquid separation, in particular, it is preferred to prepare water in the vessel, into which hydrogen fluoride is introduced, and then to contain M (but, M The compound of the above) is stirred and dissolved, and then a compound containing A (but A is the same as above) and a compound containing Mn or a compound containing A (but A is the same as above) and Mn are added, followed by stirring, dissolving, and preparing a matrix solution, and finally, while stirring the matrix solution, adding an additive comprising a fluoride of A (but, A is as described above) or a hydrofluoric acid solution in which the fluoride is dissolved, and A ₂ MF is added to the matrix solution. ₆ : A method of precipitation of Mn (however, A and M are the same as above).

As a source of the tetravalent element M, a fluoride, an oxide, a hydroxide, a carbonate, or the like can be used, and an oxide or a fluoride is preferable. These may be used alone or in combination of two or more. For example, SiO ₂ , TiO ₂ or the like can be mentioned. When these are dissolved in water together with the aqueous solution of hydrogen fluoride, it is substantially an aqueous solution containing the polyfluoride of the element M. It also can be obtained solution H ₂ SiF _6, etc. of polyvinyl fluoride salt used.

As a raw material of manganese, a fluoride, a carbonate, an oxide, a hydroxide, or the like of manganese may be used, but it is preferably used in the form of a compound containing a compound of A and Mn (fluoride, oxide, chloride, etc.). From the viewpoint of the oxidized state and the degree of ease of dissolution, it is preferred to use a double fluoride represented by A ₂ MnF ₆ or a double oxide represented by A ₂ MnO ₃ . Examples thereof include K ₂ MnF ₆ and the like.

As a source of the alkali metal A (A is one or more selected from Li, Na, K, Rb, and Cs, and at least Na and/or K), the fluoride AF, the hydrogen fluoride salt AHF ₂ , and the nitric acid can be used. The selected compounds of salt ANO ₃ , sulfate A ₂ SO ₄ , hydrogen sulfate AHSO ₄ , carbonate A ₂ CO ₃ , hydrogencarbonate AHCO ₃ and hydroxide AOH are dissolved in hydrogen fluoride (hydrogen fluoride solution) as necessary. After water, it is prepared as an aqueous solution. On the other hand, the solid (corresponding to the solid of the second solution) may be composed of fluoride AF, hydrogen fluoride salt AHF ₂ , nitrate ANO ₃ , sulfate A ₂ SO ₄ , hydrogen sulfate AHSO ₄ , carbonate A ₂ CO ₃ The compound selected from the hydrogencarbonate AHCO ₃ and the hydroxide AOH is prepared as a solid. Preferred are fluorides or hydrogen fluoride salts.

As a raw material for producing a complex fluoride phosphor A suitable method is to first add water to the reaction vessel and then to add hydrogen fluoride. In this case, the concentration of the hydrogen fluoride acid is preferably 10 to 50% by mass, particularly preferably 15 to 45% by mass, based on the substrate solution to be described later.

Then put in a combination of M (but, M is the same as above) The mixture was stirred and dissolved. The concentration of the compound of the above M in the above aqueous solution of hydrogen fluoride is 0.02 to 1.0 mol/liter in the substrate solution to be described later, preferably 0.05 to 0.5 mol/liter.

Then, a compound containing A (but, A is the same as above) is introduced. One or two or more kinds of the compound containing Mn, preferably a compound containing A and Mn, are stirred and dissolved to prepare a matrix solution. At this time, the concentration of A and the concentration of Mn are preferably 0.00005 to 0.4 mol/liter in the respective matrix solutions, particularly preferably 0.0001 to 0.2 mol/liter.

Finally, add A to the matrix solution while stirring (but, A The fluoride of the above) or the hydrofluoric acid solution in which the fluoride is dissolved is used as an additive. In this case, examples of the fluoride include sodium fluoride, sodium hydrogen fluoride, potassium fluoride, and potassium hydrogen fluoride, and particularly preferably sodium hydrogen fluoride or potassium hydrogen fluoride. Further, the concentration of the hydrogen fluoride in the hydrogen fluoride solution is preferably the same as or higher than the concentration of A in the case of using the fluoride or the hydrogen fluoride as the A raw material, and more preferably twice or more the concentration of A. When a fluoride or a hydrogen fluoride salt is used as the A raw material, the concentration of the hydrogen fluoride acid is not limited. The concentration of alkali metal A is 0.25 m / liter or more, especially 0.5 m / g Above is better. Further, the amount of the alkali metal A to be added is preferably 2.0 to 10.0 (mole ratio), more preferably 2.0 to 5.0 (mole ratio), based on the total of M and Mn in the matrix solution.

The concentration in the state in which the reaction materials are all mixed is preferably 0.02 to 1.0 mol/liter in terms of the total concentration of the elements M and Mn. More preferably 0.05 to 0.5 m / liter. Especially preferably 0.05 m / liter or more.

Further, the ratio of the total of the tetravalent element M to Mn in the state in which the reaction materials are all mixed with the alkali metal A is A/(M+Mn)=2.0 to 10.0 (mole ratio), particularly 2.0 to 5.0 (mo Ear ratio) is better.

The ratio of Mn added to the reaction system with respect to M is preferably Mn/(M+Mn)=0.002 to 0.4 (mole ratio), particularly preferably 0.005 to 0.2 (mole ratio).

The temperature of the liquid in the reaction can be carried out by heating or cooling in the range of -20 to 100 °C. The suppression of the volatilization of the hydrogen fluoride gas is preferably 60 ° C or lower, particularly preferably 50 ° C or lower.

Further, after the step of introducing the compound containing A and Mn or the step of adding at least the above-mentioned additive agent, it is carried out in an inert gas atmosphere such as Ar or nitrogen, and it is preferable from the viewpoint of preventing oxidation of Mn ions contained in the solution. .

The reaction apparatus for realizing the production method of the present invention is required to include a reaction vessel, an acid solution supply tank, a stirrer, a drip tank, a pump, a powder supply device, and a slurry discharge pipe.

More specifically, as the manufacturing apparatus, as shown in FIG. 1, each of the main reaction vessels 1 having the stirring mechanism 2 is provided with a supply a valve fitting 3 for a solution, a solution supply tank 5 having a pump 4, a powder supply device 6, a drip tank 8 having a shutter 7 attached thereto, and a shutter for discharging a slurry containing the produced polyfluoride phosphor The device of the pipe 9 is preferred.

The mixer is installed in the reaction vessel. Attached with a stirring wing In the agitator shaft, the entire agitator shaft is preferably rotated. The shape of the stirring blade can be arbitrarily selected, and examples thereof include a flat plate shape (no or oblique), an anchor shape, and the like. In the reaction, the solution in the reaction vessel is stirred in the range of from 0.5 times/second to 100 times/second. It is preferably 1 to 10 times/second.

The dropping tank can be arbitrarily arranged above the reaction vessel. The liquid can be added to the reaction vessel or a pump or the like by opening the shutter, and the flow rate can be controlled by adding the liquid to the reaction vessel. When the hydrofluoric acid solution in which the alkali metal A is dissolved is dropped into the solution, it is preferably added dropwise to the solution in a fixed amount of 1/500 to 1/10 of the total amount of the hydrogen fluoride solution. The speed is preferably 1/200 to 1/20.

In order to add the powder raw material to the reaction liquid in the reaction vessel, the powder A body supply device is necessary. The powder supply device is preferably a mechanism capable of controlling the supply amount of the powder, in order to increase the amount of the substance to be added, or to add the raw material of the alkali metal A to the powder. In order to perform solid-liquid separation of the phosphor obtained by precipitation, a slurry discharge pipe is required. The discharged slurry is subjected to solid-liquid separation by filtration, centrifugation, decantation or the like.

The complex fluoride phosphor of the present invention can be obtained as a solid product To. The solid product after solid-liquid separation can be washed, if necessary, The treatment such as solvent substitution can be carried out by vacuum drying or the like.

The phosphor obtained by the production method of the present invention is made of Mn The complex fluoride phosphor which is a luminescent center exhibits red luminescence due to blue (400 to 480 nm, as a case of 450 nm) light excitation. It has the strongest peak before and after 630 nm, and exhibits an emission spectrum composed of peaks of several sharp line widths. When it is produced under the standard conditions of the present invention, the absorption rate of light of 450 nm is 0.7 or more, preferably 0.71 to 0.85, and the internal quantum efficiency is 0.8 or more, preferably 0.82 to 0.92, preferably as a blue LED. A red phosphor for the white LED of the excitation source.

[Examples]

The present invention will be more specifically illustrated by the following examples and comparative examples, but the invention is not limited thereto.

[Example 1]

234 cm ^{3 of a} 40% by mass aqueous solution of fluoroantimonic acid (H ₂ SiF ₆ ) (manufactured by Morita Chemical Industry Co., Ltd.), first with 50% by mass of hydrofluoric acid (HF) (SA-X, manufactured by Stella-Chemifa Co., Ltd.) Mix 2,660 cm ³ . 13.32 g of K ₂ MnF ₆ powder prepared by the method of the reference example described later was previously added thereto, and stirred and dissolved. Further, 1.33 g of K ₂ MnF ₅ powder was added, and the mixture was stirred and dissolved (solution A).

Further, potassium hydrogen fluoride (Stella-Chemifa made acidic potassium fluoride, KHF ₂₎ 210.5g of 50 mass% hydrofluoric acid aqueous solution ^3, a mixed water 1,270cm ³ dissolved (solution B) 680cm.

The solution A was stirred at room temperature (15 ° C) using a stirring blade and a motor, and the solution B (15 ° C) was added in small portions for 1 minute and 30 seconds with stirring. The temperature of the liquid became 26 ° C, and a pale orange precipitate (K ₂ SiF ₆ : Mn) was produced. After further stirring for 10 minutes, the precipitate was filtered through a Buchner funnel and degreased as much as possible. Further, it was washed with acetone, deliquored, and vacuum dried to obtain a powder product K ₂ SiF ₆ : Mn 181.0 g.

The particle size distribution of the obtained powder product was measured by a gas flow dispersion type laser diffraction particle size distribution analyzer (HELOS & RODOS, manufactured by Sympatec Co., Ltd.). As a result, particles having a particle diameter of 10.27 μm or less are 10% (D10 = 10.27 μm) of the entire volume, and particles having a particle diameter of 20.26 μm or less are 50% (D50 = 20.26 μm) of the entire volume, and particles having a particle diameter of 29.68 μm or less. It is 90% of the full volume (D90 = 29.68 μm).

[Reference example] _{(K 2 MnF 6, K 2} MnF of producing ₅₎

It is prepared by the following method according to the method described in Maruzen Co., Ltd., the Japanese Chemical Society, the New Experimental Chemistry Lecture 8 "Synthesis of Inorganic Compounds III", 1977, and 1166 pages (Non-Patent Document 1).

A partition made of a fluororesin-based ion exchange membrane is disposed in the center of the reaction vessel made of a polyvinyl chloride resin, and an anode and a cathode made of a platinum plate are provided on both sides thereof. A hydrogen fluoride acid solution in which manganese (II) fluoride was dissolved was added to the anode side of the reaction vessel, and a hydrogen fluoride acid solution was added to the cathode side. The two electrodes were connected to a power source, and electrolysis was carried out at a voltage of 3 V and a current of 0.75 A. After the completion of the electrolysis, a potassium fluoride solution saturated with hydrogen fluoride was added to the reaction liquid on the anode side, and the resulting brown precipitate was collected by filtration to obtain K ₂ MnF ₅ . K ₂ MnF ₆ was obtained by filtration and recovery without filtration and electrolysis until a yellow precipitate was obtained.

[Example 2]

The powder product K ₂ SiF ₆ : Mn 181.8 g was obtained in the same manner as in Example 1 except that the amount of the K ₂ MnF ₅ powder was 0.04 g. The particle size distribution measured in the same manner as in Example 1 was D10 = 9.40 μm, D50 = 18.56 μm, and D90 = 28.08 μm.

[Example 3]

The powder product K ₂ SiF ₆ : Mn 182.1 g was obtained in the same manner as in Example 2 except that the solution in the vessel was purged with nitrogen.

The particle size distribution measured in the same manner as in Example 1 was D10: 9.45 μm, D50 = 18.68 μm, and D90 = 28.08 μm.

[Example 4]

The powder product K ₂ SiF ₆ : Mn 181.1 g was obtained in the same manner as in Example 1 except that manganese carbonate was added in an amount of 0.25 g of MnF ₂ . The particle size distribution measured in the same manner as in Example 1 was D10 = 10.16 μm, D50 = 19.82 μm, and D90 = 29.24 μm.

[Example 5]

The powder product K ₂ SiF ₆ : Mn (181.4 g) was obtained in the same manner as in Example 1 except that the solution B was placed in the solution A, and the inside of the container to which the solution A was added was a nitrogen atmosphere. The particle size distribution measured in the same manner as in Example 1 was D10 = 11.54 μm, D50 = 21.67 μm, and D90 = 31.96 μm.

[Example 6]

In the same manner as in Example 1, except that the K ₂ MnF ₆ powder was added before the addition of the K ₂ MnF ₆ powder, the powder product K ₂ SiF ₆ : Mn was obtained in the same manner as in Example 1. The particle size distribution measured in the same manner as in Example 1 was D10 = 10.78 μm, D50 = 20.82 μm, and D90 = 30.37 μm.

[Comparative Example 1]

The powder product K ₂ SiF ₆ : Mn 180.5 g was obtained in the same manner as in Example 1 except that the K ₂ MnF ₅ powder was not added.

The particle size distribution measured in the same manner as in Example 1 was D10 = 8.36 μm, D50 = 17.29 μm, and D90 = 25.56 μm.

The luminescence of the phosphor obtained in the examples and the comparative examples The quantum, the luminescence spectrum, the absorption rate, and the quantum efficiency were measured by a quantum efficiency measuring device QE1100 (manufactured by Otsuka Electronics Co., Ltd.). The absorbance and quantum efficiency at an excitation wavelength of 450 nm are shown in Table 1.

Further, the present invention has been described above by way of embodiments, but The present invention is not limited to the embodiment, and other embodiments, additions, changes, deletions, and the like can be changed within the range conceivable by the manufacturer, and are included in the present invention in any aspect that can achieve the effects of the present invention. range.

Claims (5)

A method for producing a complex fluoride phosphor characterized by the following formula (I) A ₂ MF ₆ : Mn (I) (wherein M is selected from Si, Ti, Zr, Hf, Ge, and Sn One or two or more kinds of tetravalent elements, and A is Mn represented by Li, Na, K, Rb, and Cs, and is an alkali metal containing at least one or two or more kinds of Na and/or K. In the production of an activated double-fluoride red phosphor, a compound containing M and a compound containing A and a compound containing Mn, a compound containing M, a compound containing A and Mn, a compound containing M and A, and a compound are used as a raw material. a compound of Mn or a compound containing A and Mn and a compound containing M and A, and the above-mentioned raw materials are mixed in a reaction tank in a liquid containing hydrogen fluoride or a salt thereof to cause a recombination of A ₂ MF ₆ :Mn When the phosphor is crystallized, Mn ^{4+ is} mainly contained in the raw material, and further 0.5 to 10 at% of Mn ²⁺ and/or Mn ^{3+ is} contained. The production method according to claim 1, wherein water is prepared in a container, and hydrogen fluoride is introduced therein, and then a compound containing M (however, M is as described above) is introduced, stirred, dissolved, and then charged with A (but, A The compound of the above) and the compound containing Mn or the compound containing A (but A is the same as above) and Mn are stirred and dissolved to prepare a matrix solution, and finally, the matrix solution is stirred while adding A (but, A is the same as above). When the fluoride or the hydrogen fluoride solution in which the fluoride is dissolved is added to the matrix solution, A ₂ MF ₆ : Mn (however, A and M are the same as above) is crystallized, and the above-mentioned Mn is contained. The raw material composed of the compound or the compound containing A and Mn described above contains Mn ⁴⁺ as a main component and 0.5 to 10 at% of Mn ²⁺ and/or Mn ³⁺ . The production method according to claim 1, wherein at least the crystallization reaction is carried out in an inert gas atmosphere. The production method according to claim 1, wherein the A ₂ MF ₆ :Mn crystallization liquid is subjected to a crystallization reaction while being purged with an inert gas. The production method according to claim 1, wherein the content of the activated Mn ions in the red phosphor represented by A ₂ MF ₆ : Mn (however, A and M are the same as above) is 0.2 to the entire phosphor. 1.2at%.