Method for producing inorganic fluoride luminescent material

Abstract

Provided is a method for producing an inorganic fluoride luminescent material having exceptional luminescence characteristics by using a non-aqueous hydrogen-fluoride-containing liquid.　A method for producing an inorganic fluoride luminescent material, the method including bringing a first inorganic fluoride luminescent material and a non-aqueous hydrogen-fluoride-containing liquid that has a hydrogen fluoride content in the range of 20-100 mass% (inclusive) into contact with each other to obtain a non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material, and bringing the non-aqueous solution and a non-aqueous organic liquid that has a hydrogen fluoride content of less than 20 mass% into contact with each other to precipitate a second inorganic fluoride luminescent material.　

Description

[Technical Field]

[0001] The present invention relates to a method for producing an inorganic fluoride luminescent material. [Background technology]

[0002] Fluoride crystals have excellent transparency. Inorganic fluoride luminescent materials obtained by adding rare earth metal elements to fluoride crystals are used as laser media for fiber lasers and fiber amplifiers, and as phosphors that convert the wavelength of excitation light from a light source. Phosphors are used in combination with light-emitting elements that emit light on the short wavelength side, corresponding to ultraviolet light to visible light, in light-emitting devices for lighting, automotive applications, LCD backlights, and the like.

[0003] As a phosphor, a fluoride phosphor that emits red light can be used. For example, Patent Document 1 discloses that K2SiF6:Mn 4+ A method for obtaining an inorganic fluoride phosphor having a composition represented by the formula: [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-224536 Summary of the Invention [Problem to be solved by the invention]

[0005] The optical properties of inorganic fluoride luminescent materials depend on the hydroxide ions (OH - ) or water (HO). For example, as described in Patent Document 1, inorganic fluoride phosphors produced using an aqueous solution are significantly affected by the moisture (hydroxide ions (OH) - ) or water) may affect the optical properties. Therefore, an object of the present invention is to provide a method for producing an inorganic fluoride luminescent material having excellent luminescent properties using a non-aqueous hydrogen fluoride-containing liquid. [Means for solving the problem]

[0006] One aspect of the present invention is a method for producing a non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material by contacting the first inorganic fluoride luminescent material with a non-aqueous hydrogen fluoride-containing liquid having a hydrogen fluoride content of 20% by mass or more and 100% by mass or less; and bringing the non-aqueous solution into contact with a non-aqueous organic liquid containing less than 20% by mass of hydrogen fluoride to precipitate a second inorganic fluoride luminescent material.

[0007] According to one aspect of the present invention, it is possible to provide a method for producing an inorganic fluoride luminescent material, which can provide an inorganic fluoride luminescent material having excellent luminescent properties. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a flowchart showing a method for manufacturing an inorganic fluoride luminescent material according to an embodiment. [Figure 2] FIG. 1 is a schematic cross-sectional view showing an example of a light-emitting device using an inorganic fluoride fluorescent material. [Figure 3] 1 is a diagram showing infrared reflection spectra of an inorganic fluoride phosphor according to Example 1 and an inorganic fluoride phosphor according to Comparative Example 1. FIG. [Figure 4] 1 is a diagram showing ultraviolet-visible reflection spectra of an inorganic fluoride phosphor according to Example 1 and an inorganic fluoride phosphor according to Comparative Example 1. FIG. [Figure 5] 1 is a diagram showing the excitation spectra of an inorganic fluoride phosphor according to Example 1 and an inorganic fluoride phosphor according to Comparative Example 1. FIG. [Figure 6] 1 is a diagram showing the emission spectra of an inorganic fluoride phosphor according to Example 1 and an inorganic fluoride phosphor according to Comparative Example 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] The method for producing an inorganic fluoride luminescent material according to the present invention will be described below based on one embodiment. However, the embodiment shown below is an example for realizing the technical concept of the present invention, and the present invention is not limited to the inorganic fluoride luminescent material below. The relationship between color names and chromaticity coordinates, and the relationship between light wavelength ranges and color names of monochromatic light conform to JIS Z8110.

[0010] Method for producing inorganic fluoride luminescent material The method for producing an inorganic fluoride luminescent material includes: contacting a first inorganic fluoride luminescent material with a non-aqueous hydrogen fluoride-containing liquid having a hydrogen fluoride content in the range of 20% by mass or more and 100% by mass or less to obtain a non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material; and contacting the non-aqueous solution with a non-aqueous organic liquid having a hydrogen fluoride content of less than 20% by mass to precipitate a second inorganic fluoride luminescent material.

[0011] According to the method for producing an inorganic fluoride luminescent material, an inorganic fluoride luminescent material can be produced using a non-aqueous hydrogen fluoride-containing liquid. According to the production method of this embodiment, the inorganic fluoride luminescent material can be produced by absorbing water (hydroxide ions (OH)) contained in the aqueous liquid. - ) or water), and for example, the element that becomes the luminescence center contained in the inorganic fluoride luminescent material is not easily affected by hydroxide ions (OH - ) or reduction by water, the luminescent properties of which are not deteriorated, and an inorganic fluoride luminescent material having excellent luminescent properties can be produced.

[0012] 1 is a flowchart showing an example of a method for producing an inorganic fluoride luminescent material. The method for producing an inorganic fluoride luminescent material includes the steps of: preparing a first inorganic fluoride luminescent material (S101); preparing a non-aqueous hydrogen fluoride-containing liquid having a hydrogen fluoride content of 20% by mass or more and 100% by mass or less (S102); contacting the first inorganic fluoride luminescent material with the non-aqueous hydrogen fluoride-containing liquid to obtain a non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material (S103); and contacting the non-aqueous solution with a non-aqueous organic liquid having a hydrogen fluoride content of less than 20% by mass to precipitate a second inorganic fluoride luminescent material (S105). The method for producing an inorganic fluoride luminescent material may also include the step of preparing a non-aqueous organic liquid having a hydrogen fluoride content of less than 20% by mass (S104).

[0013] Preparation of the first inorganic fluoride luminescent material The first inorganic fluoride luminescent material is Li + , Na + , K. + , Rb + , Cs + and NH4 + and Mn. The first inorganic fluoride luminescent material has a composition containing at least one A ion selected from the group consisting of:

[0014] The first inorganic fluoride luminescent material preferably has a composition represented by the following formula (Ii): The first inorganic fluoride luminescent material is preferably an inorganic fluoride phosphor having a composition represented by the following formula (Ii). A x [M 1-z Mn 4+ z F y ] (II) (In formula (Ii), A is Li + , Na + , K. + , Rb + , Cs + and NH4 +At least one ion selected from the group consisting of, M is at least one element selected from the group consisting of Group 4 elements and Group 14 elements, and x is [M 1-z Mn 4+ F y The absolute value of the charge of the ion, and y and z satisfy 5 ≦ y ≦ 7 and 0 < z < 0.2.) M is preferably at least one selected from the group consisting of Si, Ge, Ti, Zr, Hf, and Sn, more preferably at least one selected from the group consisting of Si, Ge, Ti, Zr, and Hf, and even more preferably at least one selected from the group consisting of Si, Ge, Ti, and Zr.

[0015] When the first inorganic fluoride light-emitting material is an inorganic fluoride phosphor having a composition represented by, for example, the above formula (I-i), a first aqueous solution containing hydrogen fluoride and a first fluoride complex ion containing tetravalent manganese ions, a second aqueous solution containing the A ion and hydrogen fluoride, and a third aqueous solution containing a second fluoride complex ion containing an ion composed of the M element are prepared, and the first aqueous solution, the second aqueous solution, and the third aqueous solution are mixed to produce the first inorganic fluoride light-emitting material. The method for producing the first inorganic fluoride light-emitting material can refer to, for example, the method described in JP-A-2015-44973.

[0016] Step of preparing a non-aqueous hydrogen fluoride-containing liquid Non-aqueous hydrogen fluoride-containing liquid The non-aqueous hydrogen fluoride-containing liquid has a hydrogen fluoride content in the range of 20% by mass or more and 100% by mass or less. The non-aqueous hydrogen fluoride-containing liquid may contain an amount of hydrogen fluoride that allows the first inorganic fluoride luminescent material to dissolve. The first inorganic fluoride luminescent material that comes into contact with the non-aqueous hydrogen fluoride-containing liquid dissolves, and ions derived from the first inorganic fluoride luminescent material are contained in the non-aqueous solution. When the first inorganic fluoride luminescent material is an inorganic fluoride phosphor, when the first inorganic fluoride luminescent material comes into contact with the non-aqueous hydrogen fluoride-containing liquid, A ions derived from the first inorganic fluoride luminescent material, Mn ions, ions containing an M element, and ions containing fluorine are contained in the non-aqueous solution. The ions derived from the first inorganic fluoride luminescent material contained in the non-aqueous solution may be complex ions derived from the first inorganic fluoride luminescent material. The content of hydrogen fluoride in the non-aqueous hydrogen fluoride-containing liquid in which the first inorganic fluoride luminescent material can be dissolved as ions is within the range of 20% by mass to 100% by mass. The non-aqueous hydrogen fluoride-containing liquid may be 100% by mass of liquid hydrogen fluoride under standard conditions (25°C, 1 atmosphere). The content of hydrogen fluoride in the non-aqueous hydrogen fluoride-containing liquid may be within the range of 20% by mass to 80% by mass, 30% by mass to 60% by mass, 20% by mass to 30% by mass, or 60% by mass to 80% by mass.

[0017] In addition to hydrogen fluoride, the non-aqueous hydrogen fluoride-containing liquid may contain a compound that is liquid under standard conditions (25°C, 1 atmosphere) and has a boiling point of 120°C or higher. The non-aqueous hydrogen fluoride-containing liquid may contain at least one compound selected from the group consisting of nitrogen-containing heterocyclic compounds, amines, ureas, amides, carbamic acids, trialkylphosphines, ethers, esters, alcohols, and quaternary ammonium salts. The compound contained in the non-aqueous hydrogen fluoride-containing liquid may be at least one compound selected from the group consisting of nitrogen-containing heterocyclic compounds, amines, ureas, amides, carbamic acids, trialkylphosphines, ethers, esters, alcohols, and quaternary ammonium salts. An example of a commercially available non-aqueous hydrogen fluoride-containing liquid is Olah's reagent, which is a pyridine-HF complex containing 70% by mass of hydrogen fluoride and pyridine. Another example of a non-aqueous hydrogen fluoride-containing liquid is a triethylamine-HF complex containing 28% by mass of hydrogen fluoride and triethylamine. Other examples of non-aqueous hydrogen fluoride-containing liquids include a urea-HF complex containing 65-75% by mass of hydrogen fluoride and urea, and a DMPU-HF complex containing 65% by mass of hydrogen fluoride and N,N'-dimethylpropylene urea.

[0018] Examples of the nitrogen-containing heterocyclic compounds include alicyclic compounds having a ring selected from pyrrolidine and piperidine, and heterocyclic aromatic compounds having a ring selected from pyrrole, pyrazole, imidazole, isoxazole, thiazole, thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine, indole, benzimidazole, benzoxazole, benzothiazole, benzotriazole, purine, quinoline, isoquinoline, quinoxaline, quinazoline, acridine, and phenanthroline. The nitrogen-containing heterocyclic compounds may contain fluorine, chlorine, or bromine.

[0019] Examples of the nitrogen-containing heterocyclic compound include imidazole, and examples of the fluorine-containing compound include imidazolium salts represented by the following formula (1).

[0020] [ka]

[0021] In formula (1), R1 and R3 each independently represent an alkyl group having 1 to 4 carbon atoms; 2、 R 4、 and R5 each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. In addition, some or all of R1 to R5 may be bonded to each other to form a ring. Examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, and an n-butyl group. R 2、 R 4、 and R5 may be a hydrogen atom, a methyl group, or an ethyl group, or may be a hydrogen atom. In formula (1), q is a number from 1 to 4 and does not necessarily have to be an integer. The number of q can be calculated from the elemental analysis value of the compound.

[0022] Specific examples of the compound represented by formula (1) include 1,3-dimethylimidazolium salt, 1,3,4-trimethylimidazolium salt, and 1-ethyl-3-methylimidazolium salt. 1-Ethyl-3-methylimidazolium salt is a salt that melts at room temperature. In addition, in formula (1), some or all of R1 to R5 may be bonded to each other to form a ring. Specific examples include 1,3-dimethylbenzimidazolium salt and 1-ethyl-3-methylbenzimidazolium salt.

[0023] Among the nitrogen-containing heterocyclic compounds containing fluorine, chlorine or bromine, the nitrogen-containing heterocyclic compounds mainly containing chlorine or bromine include 2-trichloromethylpyrrole, 2-tribromomethylpyrrole, 4-chloro-3-trichloromethylpyrazole, 4-chloro-3,5-bis[trichloromethyl]pyrazole, 4-chloro-3-tribromomethylpyrazole, 4-chloro-3,5-bis[tribromomethyl]pyrazole, 1-methyl-3-trichloromethylpyrazole-4-carboxylate, 1,2-bis[trichloromethyl]imidazole, 1,3 -Bis[trichloromethyl]imidazole, 1,5-bis[trichloromethyl]imidazole, 2,5-bis[trichloromethyl]imidazole, 4,5-bis[trichloromethyl]imidazole, 1,2,5-tris[trichloromethyl]imidazole, 2,3,4-tris[trichloromethyl]imidazole, 1,2-bis[tribromomethyl]imidazole, 1,3-bis[tribromomethyl]imidazole, 1,5-bis[tribromomethyl]imidazole, 2,5-bis[tribromomethyl]imidazole, 4,5-bis[tribromomethyl]imidazole ]imidazole, 1,2,5-tris[tribromomethyl]imidazole, 2,3,4-tris[tribromomethyl]imidazole, 2-trichloromethylpyridine, 3-trichloromethylpyridine, 4-trichloromethylpyridine, 2,3-2,5-bis[trichloromethyl]pyridine, 2,6-bis[trichloromethyl]pyridine, 3,5-bis[trichloromethyl]pyridine, 2-tribromomethylpyridine, 3-tribromomethylpyridine, 4-tribromomethylpyridine, 2,3-2,5-bis[tribromomethyl]pyridine, 2,6-bis Bis[tribromomethyl]pyridine, 3,5-bis[tribromomethyl]pyridine, 3-trichloromethylpyridazine, 3-tribromomethylpyridazine, 4-trichloromethylpyridazine, 4-tribromomethylpyridazine, 2,4-bis[trichloromethyl]pyrimidine, 2,6-bis[trichloromethyl]pyrimidine, 2,4-bis[tribromomethyl]pyrimidine, 2,6-bis[tribromomethyl]pyrimidine, 2,4-dichloro-5-trichloromethylpyrimidine, 2-trichloromethylpyrazine, 2-tribromomethylpyrazine, 1,3,5-Trisbis[trichloromethyl]triazine, 1,3,5-trisbis[tribromomethyl]triazine, 4-trichloromethylindole, 5-trichloromethylindole, 4-tribromomethylindole, 5-tribromomethylindole, 2-trichloromethylbenzimidazole, 2-tribromomethylbenzimidazole, 5-trichloromethyl-1H-benzotriazole, 5-tribromomethyl-1H-benzotriazole, 6-trichloromethylpurine, 6-tribromomethylpurine, 3-trichloromethylquinoline, 4-trichloromethylquinoline, 3-tribromomethylquinoline, 4-tribromomethyl Examples of the bromomethyl quinolone include 3-trichloromethylisoquinoline, 3-tribromomethylisoquinoline, 4-trichloromethylchinoline, 4-tribromomethylchinoline, 2-trichloromethylquinoxaline, 2-tribromomethylquinoxaline, 5-trichloromethylquinoxaline, 5-tribromomethylquinoxaline, 9-trichloromethylacridine, 9-tribromomethylacridine, 4-trichloromethyl-1,10-phenanthroline, 4-tribromomethyl-1,10-phenanthroline, 5-trichloromethyl-1,10-phenanthroline, and 5-tribromomethyl-1,10-phenanthroline.

[0024] Among the oxygen- and nitrogen-containing heterocyclic compounds containing fluorine, chlorine, or bromine, examples of the oxygen- and nitrogen-containing heterocyclic compounds containing chlorine or bromine include 3,5-bis[trichloromethyl]isoxazole, 3,5-bis[tribromomethyl]isoxazole, 2-trichloromethylbenzoxazole, and 2-tribromomethylbenzoxazole.

[0025] Among the sulfur- and nitrogen-containing heterocyclic compounds containing fluorine, chlorine, or bromine, examples of the sulfur- and nitrogen-containing heterocyclic compounds containing chlorine or bromine include 4,5-bis[trichloromethyl]thiazole, 4,5-bis[tribromomethyl]thiazole, 5-trichloromethyl-thiadiazole, 5-tribromomethyl-thiadiazole, 2-trichloromethylbenzothiazole, and 2-tribromomethylbenzothiazole.

[0026] Examples of amines include methylamine, ethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, n-propylamine, isopropylamine, n-butylamine, dibutylamine, tributylamine, diethylenetriamine, monoethanolamine, triethanolamine, 1,2-propylenediamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, o-toluidine, p-nitrotoluene, N-(2-aminoethyl)ethanolamine, aniline, piperazine, and triethylenetetramine.

[0027] Examples of ureas include urea, 1,1,3,3-tetramethylurea, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-di(n-propyl)-2-imidazolidinone, 1,3-di(n-butyl)-2-imidazolidinone, 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone, N,N'-dimethylpropylurea, N,N'-diethylpropylurea, N,N'-di(n-propyl)propylurea, and N,N'-di(n-butyl)propylurea.

[0028] Examples of amides include N,N'-dimethylformamide, N,N'-diethylformamide, N,N'-dimethylacetamide, and 1-methyl-2-pyrrolidone.

[0029] Examples of carbamic acids include carbamic acid and ethyl carbamate.

[0030] Examples of trialkylphosphines include hexamethylphosphoramide.

[0031] Examples of ethers include n-butyl ether, n-hexyl ether, anisole, phenetole, butylphenyl ether, amylphenyl ether, methoxytoluene, benzyl methyl ether, diphenyl ether, dibenzyl ether, 1,2-diethoxyethane, 1,2-dibutoxyethane, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol dibutyl ether.

[0032] Examples of esters include n-butyl acetate, n-pentyl acetate, isopentyl acetate, cyclohexyl acetate, benzyl acetate, butyl propionate, isopentyl propionate, methyl benzoate, dimethyl phthalate, and γ-butyrolactone.

[0033] The alcohols are alcohols having a hydrocarbon group with 4 or more carbon atoms, such as 1-butanol, 2-methyl-1-propanol, 2-butanol, 2-methyl-2-propanol, butanol, 1-pentanol, 2-pentanol, 1-hexanol, 2-hexanol, 2-methyl-2-pentanol, 1-heptanol, 2-heptanol, 1-octanol, 1-nonanol, 1-decanol, 1-undecanol, and 1-dodecanol.

[0034] The quaternary ammonium salt includes a quaternary ammonium salt represented by the following formula (2).

[0035] [ka]

[0036] In formula (2), R6 represents an alkyl group having 1 to 4 carbon atoms, R7 represents a methoxymethyl group, a methoxyethyl group, or an ethoxymethyl group, and q represents a number from 1 to 4.

[0037] The quaternary ammonium salt represented by formula (2) is composed of a quaternary ammonium cation and a fluorohydrogenate anion. Examples of R6 in the quaternary ammonium cation include linear or branched alkyl groups having 1 to 4 carbon atoms. Specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and tert-butyl groups. Examples of R7 in the quaternary ammonium cation include methoxymethyl, methoxyethyl, and ethoxymethyl groups. Examples of the fluorohydrogenate anion include F(HF) where q is a number between 1 and 4. q - Examples of the fluorohydrogenate anion include the fluorohydrogenate anion represented by the following formula: q does not necessarily have to be an integer, and is preferably a number of 1.5 or more and 3 or less, and more preferably a number of 2 or more and 2.5 or less.

[0038] Specific examples include N-methoxymethyl-N-methylpyrrolidinium fluorohydrogenate, N-methoxymethyl-N-ethylpyrrolidinium fluorohydrogenate, N-methoxymethyl-Nn-propylpyrrolidinium fluorohydrogenate, N-methoxymethyl-N-iso-propylpyrrolidinium fluorohydrogenate, N-methoxymethyl-Nn-butylpyrrolidinium fluorohydrogenate, N-methoxymethyl-N-iso-butylpyrrolidinium fluorohydrogenate, N-methoxymethyl-N-tert-butylpyrrolidinium fluorohydrogenate, N-methoxyethyl-N-methylpyrrolidinium fluorohydrogenate, N-methoxyethyl-N-ethylpyrrolidinium fluorohydrogenate, N-methoxyethyl-Nn-propylpyrrolidinium fluorohydrogenate, and N-methoxyethyl-N-iso-propylpyrrolidinium. Examples of the fluorohydrogenate include N-methoxyethyl-Nn-butylpyrrolidinium fluorohydrogenate, N-methoxyethyl-N-iso-butylpyrrolidinium fluorohydrogenate, N-methoxyethyl-N-tert-butylpyrrolidinium fluorohydrogenate, N-ethoxymethyl-N-methylpyrrolidinium fluorohydrogenate, N-ethoxymethyl-N-ethylpyrrolidinium fluorohydrogenate, N-ethoxymethyl-Nn-propylpyrrolidinium fluorohydrogenate, N-ethoxymethyl-N-iso-propylpyrrolidinium fluorohydrogenate, N-ethoxymethyl-Nn-butylpyrrolidinium fluorohydrogenate, N-ethoxymethyl-N-iso-butylpyrrolidinium fluorohydrogenate, and N-ethoxymethyl-N-tert-butylpyrrolidinium fluorohydrogenate.

[0039] Obtaining a non-aqueous solution The non-aqueous solution can be obtained by contacting the first inorganic fluoride luminescent material with a non-aqueous hydrogen fluoride-containing liquid. The first inorganic fluoride luminescent material may be added to the non-aqueous hydrogen fluoride-containing liquid while stirring the non-aqueous hydrogen fluoride-containing liquid to obtain a non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material. By contacting the first inorganic fluoride luminescent material with the non-aqueous hydrogen fluoride-containing liquid to obtain a non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material, hydroxide ions (OH - ) to fluoride ions (F - ) and hydroxide ion (OH - ) and has excellent luminescent properties.

[0040] The concentration of the first inorganic fluoride luminescent material in the non-aqueous solution is preferably in the range of 0.01 g / mL to 1.0 g / mL, and may be in the range of 0.03 g / mL to 0.8 g / mL, or in the range of 0.05 g / mL to 0.5 g / mL. When the concentration of the first inorganic fluoride luminescent material in the non-aqueous solution is in the range of 0.01 g / mL to 1.0 g / mL, hydroxide ions (OH - ) to fluoride ions (F - ) to obtain a second inorganic fluoride luminescent material. - It is possible to obtain a second inorganic fluoride luminescent material that does not contain hydroxide ions (OH − ) or has reduced hydroxide ions (OH − ).

[0041] Non-aqueous organic liquid preparation process Non-aqueous organic liquid The non-aqueous organic liquid has a hydrogen fluoride content of less than 20% by mass. The hydrogen fluoride content in the non-aqueous organic liquid may be an amount sufficient to precipitate a second inorganic fluoride luminescent material derived from the first inorganic fluoride luminescent material in a mixture of a non-aqueous solution and a non-aqueous organic liquid (hereinafter also referred to as a "non-aqueous liquid mixture"). The hydrogen fluoride content in the non-aqueous organic liquid that can precipitate the second inorganic fluoride luminescent material in the non-aqueous liquid mixture is less than 20% by mass. The hydrogen fluoride content in the non-aqueous organic liquid may be 10% by mass or less, 5% by mass or less, 3% by mass or less, or 1% by mass or less. The hydrogen fluoride content may be 0% by mass, and the non-aqueous organic liquid may be substantially free of hydrogen fluoride. A non-aqueous organic liquid that is substantially free of hydrogen fluoride refers to a non-aqueous organic liquid having a fluorine content of less than 1% by mass. The non-aqueous organic liquid includes at least one selected from the group consisting of nitriles, ketones, amines, amides, nitrogen-containing heterocyclic compounds, fluorocompounds, ethers, esters, alcohols, and mixtures thereof. The non-aqueous organic liquid may be at least one selected from the group consisting of nitriles, ketones, amines, amides, nitrogen-containing heterocyclic compounds, fluorocompounds, ethers, esters, alcohols, and mixtures thereof.

[0042] Examples of nitriles include acetonitrile, propionitrile, benzonitrile, acrylonitrile, and methacrylonitrile.

[0043] Examples of ketones include acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, etc. Examples of ketone compounds having a hydroxyl group (alcohol) as a functional group include diacetone alcohol, etc. Examples include:

[0044] Examples of fluoro compounds include 1,1,2,2-tetrafluoroethylene, 2,2,3,3-tetrafluoropropyl ether, perfluorocarbon, hydrochlorofluorocarbon, hydrofluorocarbon, and hydrofluoroether.

[0045] Examples of the amines, amides, nitrogen-containing heterocyclic compounds, ethers, esters, and alcohols include the compounds exemplified above as compounds used in the non-aqueous hydrogen fluoride-containing liquid. The amines, amides, nitrogen-containing heterocyclic compounds, ethers, esters, and alcohols may be the same or different compounds as those used in the non-aqueous hydrogen fluoride-containing liquid.

[0046] Precipitating a second inorganic fluoride luminescent material In the step of precipitating the second inorganic fluoride luminescent material, a non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material is contacted with a non-aqueous organic liquid to precipitate the second inorganic fluoride luminescent material in the non-aqueous liquid mixture. The contact between the non-aqueous solution and the non-aqueous organic liquid is preferably carried out by dropping the non-aqueous organic liquid while stirring the non-aqueous solution, thereby precipitating the second inorganic fluoride luminescent material. The non-aqueous solution is preferably continuously stirred, and the non-aqueous organic liquid is preferably continuously dropped into the continuously stirred non-aqueous solution to precipitate the second inorganic fluoride luminescent material. The second inorganic fluoride luminescent material can be precipitated by dropping the non-aqueous organic liquid while continuously stirring the non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material. The contact between the non-aqueous solution and the non-aqueous organic liquid may be carried out using a batch reactor.

[0047] In the step of precipitating the second inorganic fluoride luminescent material, the temperature of the non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material is preferably in the range of 10°C to 40°C, and the temperature of the non-aqueous organic liquid is preferably in the range of 10°C to 40°C. When the temperatures of the non-aqueous solution and the non-aqueous organic liquid are in the range of 10°C to 40°C, adhesion of organic impurities to the precipitated second inorganic fluoride luminescent material is reduced, making it easier to precipitate a purified second inorganic fluoride luminescent material. The temperature of the non-aqueous solution may be in the range of 15°C to 35°C, or may be approximately room temperature. The temperature of the non-aqueous organic liquid may be in the range of 15°C to 35°C, or may be approximately room temperature. The temperature difference between the non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material and the non-aqueous organic liquid may be 30°C or less, or may be 20°C or less, 10°C or less, or even 0°C.

[0048] In the step of precipitating the second inorganic fluoride luminescent material, the volume ratio of the non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material to the non-aqueous organic liquid (non-aqueous solution:non-aqueous organic liquid) is preferably in the range of 1:1 to 5:1, may be in the range of 1:1 to 4:1, or may be in the range of 1:1 to 3:1. If the volume of the non-aqueous solution is in the range of 1 to 5 times the volume of the non-aqueous organic liquid, hydroxide ions (OH - ) is replaced with fluoride ions, and a purified second inorganic fluoride luminescent material can be precipitated.

[0049] In the step of precipitating the second inorganic fluoride luminescent material, when the non-aqueous organic liquid is added dropwise while continuously stirring the non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material, the stirring speed of the non-aqueous solution is preferably within a range of 20 rpm to 1000 rpm, and may be within a range of 30 rpm to 800 rpm, or may be within a range of 50 rpm to 500 rpm, or may be within a range of 80 rpm or more and 400 rpm or less. When the stirring speed of the non-aqueous solution is within a range of 20 rpm to 1000 rpm, the non-aqueous solution and the non-aqueous organic liquid are sufficiently contacted with each other, and hydroxide ions (OH - ) are replaced by fluoride ions, and a purified second inorganic fluoride luminescent material can be precipitated. The method for stirring the non-aqueous solution may be any method that can alleviate the concentration gradient of each component contained in the non-aqueous solution. Stirring methods include rotating a stirrer at a constant speed, pressurizing the non-aqueous solution with a pump to generate a flow, and using a mechanical stirrer.

[0050] In the step of precipitating the second inorganic fluoride luminescent material, the dropping speed of the non-aqueous organic liquid is preferably in the range of 0.1 mL / min to 10 mL / min, and may be in the range of 0.5 mL / min to 8 mL / min, or may be in the range of 1 mL / min to 7 mL / min. If the dropping speed of the non-aqueous organic liquid dropped into the non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material is in the range of 0.1 mL / min to 10 mL / min, the non-aqueous solution and the non-aqueous organic liquid will be in sufficient contact with each other, and hydroxide ions (OH - ) is replaced with fluoride ions, and a purified second inorganic fluoride luminescent material can be precipitated.

[0051] In the method for producing an inorganic fluoride light-emitting material, the obtained second inorganic fluoride light-emitting material may be subjected to post-treatment such as separation treatment, washing treatment, and drying treatment from a non-aqueous liquid mixture. The washing treatment can be performed using a non-aqueous organic liquid. The drying treatment can be carried out by means of devices and methods commonly used industrially, such as a vacuum dryer, a heating dryer, a conical dryer, a rotary evaporator, etc. The drying temperature in the heating drying treatment may be a temperature at which the liquid adhering to the second inorganic fluoride light-emitting material evaporates, usually 40°C or higher, preferably 50°C or higher, and usually 100°C or lower, preferably 70°C or lower. The drying time may be a time at which the liquid adhering to the second inorganic fluoride light-emitting material evaporates, for example, about 8 hours.

[0052] The second inorganic fluoride light-emitting material The second inorganic fluoride light-emitting material preferably has a composition represented by the following formula (I). The second inorganic fluoride light-emitting material is preferably an inorganic fluoride phosphor having a composition represented by the following formula (I). A x [M 1-z Mn 4+ z F y (I) (In formula (I), A is at least one ion selected from the group consisting of Li + , Na + , K [[ID=2P]] + , Rb + , Cs + [[ID=Z9]]and NH4 + . M is at least one element selected from the group consisting of Group 4 elements and Group 14 element elements. x is the absolute value of the charge of the [M 1-z Mn 4+ z F y ion, and y and z satisfy 5 ≤ y ≤ 7 and 0 < z < 0.2, respectively.) M is preferably at least one selected from the group consisting of Si, Ge, Ti, Zr, Hf, and Sn, more preferably at least one selected from the group consisting of Si, Ge, Ti, Zr, and Hf, and even more preferably at least one selected from the group consisting of Si, Ge, Ti, and Zr.

[0053] The second inorganic fluoride luminescent material obtained by the manufacturing method according to the present disclosure has hydroxide ions (OH - ) to fluoride ions (F - ) to form hydroxide ions (OH - ) content can be reduced, so the hydroxide ion (OH - Due to the influence of the fluorine-containing compound, the element that serves as the luminescence center is less likely to be reduced, and excellent luminescence properties can be maintained. The components (e.g., pyridine) contained in the non-aqueous hydrogen fluoride-containing liquid can be detected by nuclear magnetic resonance (proton NMR) by dissolving the resulting second inorganic fluoride luminescent material in a deuterated solvent.

[0054] As the second inorganic fluoride luminescent material obtained by the manufacturing method according to the present disclosure, for example, an inorganic fluoride phosphor having a composition represented by formula (I) contains Mn 4+The inorganic fluoride phosphor is activated by the formula (I) and absorbs light in the short wavelength region of visible light, emitting red light. The excitation light, which is light in the short wavelength region of visible light, is preferably light in the blue region. Specifically, the excitation light irradiated onto the inorganic fluoride phosphor having the composition represented by formula (I) as the second inorganic fluoride luminescent material preferably has an emission spectrum with a peak wavelength in the range of 380 nm to 485 nm. The emission spectrum of the inorganic fluoride phosphor having the composition represented by formula (I) preferably has a peak wavelength in the range of 610 nm to 650 nm. Furthermore, the half width of the emission spectrum of the inorganic fluoride phosphor having the composition represented by formula (I) as the second inorganic fluoride luminescent material is preferably small, specifically, 10 nm or less. The half width refers to the full width at half maximum (FWHM) of the emission peak in the emission spectrum, and refers to the wavelength width of the emission peak that is 50% of the maximum value of the emission peak in the emission spectrum.

[0055] As the second inorganic fluoride luminescent material, an inorganic fluoride phosphor having a composition represented by formula (I) can be used in a light-emitting device used in a lighting device, a backlight for a liquid crystal display device, etc., in combination with an excitation light source such as an LED or an LD.

[0056] The excitation light source used in the light-emitting device can be an excitation light source that emits light in the wavelength range of 400 nm to 570 nm. By using an excitation light source in this wavelength range, a light-emitting device with high emission intensity can be provided. The light-emitting element used as the excitation light source for the light-emitting device preferably has an emission peak wavelength in the range of 420 nm to 500 nm, more preferably in the range of 420 nm to 460 nm.

[0057] As a light-emitting element, nitride semiconductors (In X Al Y Ga 1-X-YIt is preferable to use a semiconductor light-emitting element using a semiconductor light-emitting element having a wavelength of 0≦X, 0≦Y, X+Y≦1. By using a semiconductor light-emitting element as an excitation light source for a light-emitting device, it is possible to obtain a stable light-emitting device that is highly efficient, has high output linearity relative to input, and is resistant to mechanical shock. The half-width of the emission spectrum of the light-emitting element is preferably, for example, 30 nm or less.

[0058] The light emitting device can use, for example, an inorganic fluoride phosphor having a composition represented by formula (I) as the second inorganic fluoride luminescent material. For example, an inorganic fluoride phosphor having a composition represented by formula (I) can be used as the first phosphor, and a second phosphor having an emission peak wavelength different from that of the first phosphor can be used. As the first phosphor, one type of phosphor can be used alone, or two or more types of phosphors can be used in combination, as long as they have an emission peak wavelength within the desired wavelength range. As the second phosphor, one type of phosphor can be used alone, or two or more types of phosphors can be used in combination, as long as they have an emission peak wavelength within the desired wavelength range.

[0059] An example of a light emitting device will be described with reference to the drawings. Figure 2 is a schematic cross-sectional view showing an example of a light emitting device. This light emitting device is an example of a surface-mounted light emitting device.

[0060] The light emitting device 100 includes a package 40 having a recess formed by lead electrodes 20, 30 and a molded body 42, a light emitting element 10, and a sealing member 50 that covers the light emitting element 10. The light emitting element 10 is disposed in the recess of the package 40 and is electrically connected to a pair of positive and negative lead electrodes 20, 30 provided on the package 40 by conductive wires 60. The sealing member 50 fills the recess, covers the light emitting element 10, and seals the recess of the package 40. The sealing member 50 includes, for example, a phosphor 70 that converts the wavelength of light from the light emitting element 10 and a resin. The phosphor 70 further includes a first phosphor 71 and a second phosphor 72. The pair of positive and negative lead electrodes 20, 30 are partially exposed on the outer surface of the package 40. The light emitting device 100 emits light when power is supplied from an external source via the lead electrodes 20, 30.

[0061] The sealing member 50 contains a resin and a phosphor 70, and is formed so as to cover the light emitting element 10 placed in the recess of the light emitting device 100. [Example]

[0062] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0063] Example 1 Preparation of the first inorganic fluoride luminescent material 0.99 g of potassium hexafluoromanganate (K2MnF6) and 34.58 g of hexafluorosilicic acid (H2SiF6) were weighed out and dissolved in 100 mL of an HF aqueous solution containing 55 mass % hydrogen fluoride and 45 mass % deionized water, and then 100 mL of deionized water was added to prepare a first aqueous solution. Furthermore, 15.6 g of potassium hydrogen fluoride (KHF2) was weighed out and dissolved in 50 mL of an aqueous HF solution containing 55 mass % of hydrogen fluoride and 45 mass % of deionized water to prepare a second aqueous solution. Next, the second aqueous solution was added dropwise to the first aqueous solution over a period of about 10 minutes while stirring the first aqueous solution at room temperature to obtain a precipitate. The obtained precipitate was subjected to solid-liquid separation, washed with ethanol, and dried at 110°C for 8 hours to obtain K2[Si 0.958 Mn 4+ 0.042 A first inorganic fluoride phosphor having a composition represented by the formula: Mn content (mass %) in the first inorganic fluoride phosphor was 1.03 mass %.

[0064] Preparation process of non-aqueous hydrogen fluoride-containing liquid As a non-aqueous hydrogen fluoride-containing liquid, a pyridine-HF complex solution containing 70 mass % hydrogen fluoride and 30 mass % pyridine was prepared.

[0065] Obtaining a non-aqueous solution 10.00 g of the first inorganic fluoride phosphor was dissolved in 90 mL of a non-aqueous hydrogen fluoride-containing liquid to obtain a non-aqueous solution containing ions derived from the first inorganic fluoride phosphor. The concentration of the first inorganic fluoride phosphor in the non-aqueous solution was 0.1 g / mL.

[0066] Second inorganic fluoride luminescent material deposition process A non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material in a batch-type reaction vessel was adjusted to 25°C and continuously stirred at 30 rpm using a mechanical stirrer. A non-aqueous organic liquid, acetonitrile at approximately 25°C, was continuously added dropwise at a rate of 1 mL / min for 100 minutes using a tubular metering pump (Pump 33, manufactured by Harvard). The acetonitrile used as the non-aqueous organic liquid was substantially free of hydrogen fluoride, with a hydrogen fluoride content of substantially 0% by mass. The volume ratio of the non-aqueous solution to the non-aqueous organic liquid was 1:1. A precipitate was precipitated in the non-aqueous liquid mixture. The precipitate was subjected to solid-liquid separation, washed with acetonitrile, then with isopropanol, and vacuum-dried at 25°C for 8 hours to obtain K2[Si] as the second inorganic fluoride luminescent material. 0.962 Mn 4+ 0.038 A second inorganic fluoride phosphor of Example 1 having a composition represented by the formula: [F6] was prepared. The Mn content (mass%) in the second inorganic fluoride phosphor of Example 1, measured by the measurement method described below, was 0.93 mass%. When the second inorganic fluoride phosphor of Example 1 was dissolved in a deuterated solvent and measured by nuclear magnetic resonance (proton NMR), pyridine, a component contained in the non-aqueous hydrogen fluoride-containing liquid, was detected from the second inorganic fluoride phosphor of Example 1.

[0067] Comparative Example 1 The first inorganic fluoride phosphor used as the first inorganic fluoride luminescent material of Example 1 was the inorganic fluoride luminescent material of Comparative Example 1. When the inorganic fluoride luminescent material of Comparative Example 1 was dissolved in a deuterated solvent and measured by nuclear magnetic resonance (proton NMR), the inorganic fluoride luminescent material of Comparative Example 1 did not contain pyridine (pyridine was 0 ppm by mass).

[0068] Evaluation and Results 1 Infrared reflectance spectrum The infrared reflectance spectrum of each inorganic fluoride phosphor was measured by a diffuse reflectance method using a Fourier transform infrared spectrophotometer (FT / IR-6600, manufactured by JASCO Corporation.) Figure 3 shows the infrared reflectance spectra of the second inorganic fluoride phosphor according to Example 1 and the first inorganic fluoride phosphor according to Comparative Example 1.

[0069] Evaluation and Results 2 Mn content and internal quantum efficiency The Mn content (mass%) of each inorganic fluoride phosphor was measured using a high-frequency inductively coupled plasma (ICP) optical emission spectrometer (PS3500DD-II, Hitachi High-Tech Science Corporation). Furthermore, the emission spectrum of each inorganic fluoride phosphor excited by excitation light with an emission peak wavelength of 450 nm was measured using a quantum efficiency measurement device (QE-2100, Otsuka Electronics Co., Ltd.), and the internal quantum efficiency of the emission of each inorganic fluoride phosphor was measured from the emission spectrum in the range of 600 nm to 650 nm.

[0070] [Table 1]

[0071] The infrared reflectance spectrum of the second inorganic fluoride phosphor according to Example 1 is 2500 cm -1 From 4000cm -1 In the wave number region of 2500 cm, the decrease in the infrared reflection spectrum is suppressed compared to the infrared reflection spectrum of the first inorganic fluoride luminescent material according to Comparative Example 1. -1 From 4000cm -1 The reduction in the infrared reflectance spectrum in the wavenumber region is due to hydroxide ions (OH - ) or indicates the presence of water, and -1 From 4000cm -1 The fact that the reduction in the infrared reflectance spectrum in the wavenumber region is suppressed is due to the hydroxide ions (OH -) or water is less than that of the first inorganic fluoride phosphor of Comparative Example 1. - ) and water, and the deterioration of optical properties due to hydroxide ions was suppressed.

[0072] The second inorganic fluoride phosphor according to Example 1 has a hydroxide ion (OH - ) and water, and the tetravalent manganese that forms the luminescence center is not reduced to a trivalent state but remains tetravalent. Therefore, the internal quantum efficiency was higher than that of the first inorganic fluoride phosphor of Comparative Example 1, and the phosphor had excellent luminescence properties.

[0073] Evaluation and Results 3 UV-Visible Reflectance Spectrum The ultraviolet-visible reflectance spectrum of each inorganic fluoride phosphor was measured using an ultraviolet-visible near-infrared spectrophotometer (U-4100, manufactured by Hitachi High-Tech Science Corp.) Figure 4 shows the ultraviolet-visible reflectance spectra of the second inorganic fluoride phosphor according to Example 1 and the first inorganic fluoride phosphor according to Comparative Example 1.

[0074] It was confirmed that the ultraviolet-visible reflection spectrum of the second inorganic fluoride phosphor according to Example 1 has a higher reflectance in the wavelength range of 500 nm to 600 nm than the ultraviolet-visible reflection spectrum of the first inorganic fluoride phosphor according to Comparative Example 1. In the ultraviolet-visible reflection spectrum of the second inorganic fluoride phosphor according to Example 1, the reduction in reflectance in the ultraviolet-visible reflection spectrum in the wavelength range of 500 nm to 600 nm is due to the presence of Mn, which does not contribute to light emission. 3+ The UV-visible reflection spectrum of the second inorganic fluoride phosphor according to Example 1 has a higher reflectance in the wavelength range of 500 nm to 600 nm than the UV-visible reflection spectrum of the first inorganic fluoride phosphor according to Comparative Example 1, which is due to the presence of Mn, which does not contribute to light emission. 3+ Mn contributes relatively little to luminescence 4+From the ultraviolet-visible reflectance spectrum of the second inorganic fluoride phosphor according to Example 1, it can be seen that the second inorganic fluoride phosphor according to Example 1 contains more Mn, which does not contribute to light emission, than the first inorganic fluoride phosphor according to Comparative Example 1. 3+ Mn contributes relatively little to luminescence 4+ It had a high content of fluorine and excellent luminescence properties.

[0075] Evaluation and Results 4 and 5 Excitation and Emission Spectra The excitation spectrum and emission spectrum of each inorganic fluoride phosphor were measured using a spectrofluorometer (FP-8500DS, manufactured by JASCO Corporation). Fig. 5 shows the excitation spectrum of the second inorganic fluoride phosphor according to Example 1 and the first inorganic fluoride phosphor according to Comparative Example 1. Fig. 6 shows the emission spectrum of the second inorganic fluoride luminescent material according to Example 1 and the first inorganic fluoride luminescent material according to Comparative Example 1.

[0076] It was confirmed that the second inorganic fluoride phosphor according to Example 1 and the first inorganic fluoride phosphor according to Comparative Example 1 have excitation spectrum peaks at 350 nm and 450 nm, and have high absorption of excitation light of approximately the same wavelength.

[0077] The second inorganic fluoride phosphor according to Example 1 and the first inorganic fluoride phosphor according to Comparative Example 1 had almost the same emission spectrum, and both had sharp emission spectra with narrow half-widths. [Industrial Applicability]

[0078] The inorganic fluoride luminescent material obtained by the manufacturing method of the present disclosure can be used as a fiber laser, a laser medium for a fiber amplifier, or a phosphor. In particular, among the inorganic fluoride luminescent materials obtained by the manufacturing method of the present disclosure, the inorganic fluoride phosphor can be suitably used in lighting sources using light-emitting diodes as excitation light sources, light sources for LED displays or liquid crystal backlights, traffic lights, illuminated switches, various sensors, various indicators, small strobes, etc. [Explanation of symbols]

[0079] 10: light emitting element, 20, 30: lead electrode, 40: package, 42: molded body, 50: sealing member, 60: wire, 70: phosphor, 71: first phosphor, 72: second phosphor, 100: light emitting device.

Claims

1. contacting a first inorganic fluoride luminescent material with a non-aqueous hydrogen fluoride-containing liquid having a hydrogen fluoride content in the range of 20% by mass or more and 100% by mass or less to obtain a non-aqueous solution containing ions derived from the first inorganic fluoride luminescent material; and contacting the non-aqueous solution with a non-aqueous organic liquid having a hydrogen fluoride content of less than 20 mass % to precipitate a second inorganic fluoride luminescent material.

2. 2. The method for producing an inorganic fluoride luminescent material according to claim 1, wherein the non-aqueous hydrogen fluoride-containing liquid contains at least one selected from the group consisting of nitrogen-containing heterocyclic compounds, amines, ureas, amides, carbamic acids, trialkylphosphines, ethers, esters, alcohols, and quaternary ammonium salts.

3. 3. The method for producing an inorganic fluoride luminescent material according to claim 1 or 2, wherein the non-aqueous organic liquid comprises at least one selected from the group consisting of nitriles, ketones, amines, amides, nitrogen-containing heterocyclic compounds, fluoro compounds, ethers, esters, alcohols, and mixtures thereof.

4. 4. The method for producing an inorganic fluoride luminescent material according to claim 1, wherein the concentration of the first inorganic fluoride luminescent material in the non-aqueous solution is in the range of 0.01 g / mL or more and 1.0 g / mL or less.

5. 5. The method for producing an inorganic fluoride luminescent material according to claim 1, wherein in the step of precipitating the second inorganic fluoride luminescent material, the temperature of the non-aqueous solution is in the range of 10°C or more and 40°C or less, the temperature of the non-aqueous organic liquid is in the range of 10°C or more and 40°C or less, and the temperature difference between the temperature of the non-aqueous solution and the temperature of the non-aqueous organic liquid is less than 10°C.

6. 6. The method for producing an inorganic fluoride luminescent material according to claim 1, wherein in the step of precipitating the second inorganic fluoride luminescent material, the volume ratio of the non-aqueous solution to the non-aqueous organic liquid is 1:1 to 5:

1.

7. 7. The method for producing an inorganic fluoride luminescent material according to claim 1, wherein in the step of precipitating the second inorganic fluoride luminescent material, the non-aqueous organic liquid is added dropwise while continuously stirring the non-aqueous solution to precipitate the second inorganic fluoride luminescent material.

8. 8. The method for producing an inorganic fluoride luminescent material according to claim 7, wherein in the step of precipitating the second inorganic fluoride luminescent material, the stirring speed of the non-aqueous solution is in the range of 20 rpm to 1000 rpm.

9. 9. The method for producing an inorganic fluoride luminescent material according to claim 7 or 8, wherein in the step of precipitating the second inorganic fluoride luminescent material, the dropping speed of the non-aqueous organic liquid is in the range of 0.1 mL / min to 10 mL / min.

10. The method for producing an inorganic fluoride luminescent material according to claim 1 , wherein the second inorganic fluoride luminescent material has a composition represented by the following formula (I): A ｘ [M １－ｚ Mn ４＋ ｚ F ｙ ] (I) (In formula (I), A is Li ＋ , Na ＋ , K. ＋ , Rb ＋ , Cs ＋ and N.H. ４ ＋ where M is at least one element selected from the group consisting of Group 4 elements and Group 14 elements, and x is [M １－ｚ Mn ４＋ ｚ F ｙ ] is the absolute value of the charge of the ion, and y and z satisfy the ranges 5≦y≦7 and 0<z<0.2, respectively.

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