Red phosphor and its manufacturing method

Abstract

The present invention provides a red phosphor with excellent optical properties and durability under high temperature and high humidity environments, and a method for manufacturing the same. The red phosphor according to the present invention comprises an Mn reactivated polyfluoride represented by general formula (1) and a perovskite compound represented by general formula (2). L2MF6:Mn4+(1) (In the formula, L represents at least one alkali metal element selected from the group consisting of sodium, potassium, etc., and M represents at least one tetravalent element selected from the group consisting of silicon, germanium, etc.) ABX3(2) (In the formula, A represents at least one element selected from the group consisting of sodium, potassium, etc. B represents at least one element selected from the group consisting of magnesium, calcium, etc. X represents at least one element selected from the group consisting of fluorine, chlorine, bromine, iodine, and sulfur.)

Description

Technology Field

[0001] The present invention relates to a red phosphor that emits red light when excited by excitation light such as ultraviolet light and blue light, and a method for manufacturing the same. More specifically, the invention relates to a red phosphor comprising a Mn (manganese) reactivated polyfluoride and a perovskite compound, wherein the perovskite compound is present on or within the surface of the Mn reactivated polyfluoride, thereby providing a red phosphor with excellent optical properties and durability under high temperature and high humidity environments, and a method for manufacturing the same. Background Technology

[0002] White LEDs (Light Emitting Diodes) have a longer lifespan and lower power consumption compared to fluorescent lamps. For this reason, their widespread adoption as backlights for lighting fixtures and displays has progressed rapidly. White LEDs in commercially available lighting fixtures are composed of a combination of a blue LED that emits light ranging from near-ultraviolet to blue light, and a yellow phosphor that is excited by that light. Consequently, white LEDs enable the emission of pseudo-white light by mixing the light emitted by the blue LED with the light emitted by the yellow phosphor. However, because the pseudo-white light emitted by white LEDs contains little to no red light component, there is a problem in that the pseudo-white light has lower color rendering index (CRI) compared to natural light (or sunlight, blackbody radiation). (CRI refers to the characteristic of color visibility when viewing an object under that lighting compared to the aforementioned natural light. For example, high CRI is indicated when an object appears to have colors similar to those seen when illuminated by natural light when illuminated by the lighting.)

[0003] Therefore, there is a need for red phosphors that emit red light when excited by ultraviolet light emitted by near-ultraviolet LEDs or blue light emitted by blue LEDs. As such red phosphors, in recent years, the transition metal Mn 4+Mn reactivated complex fluoride (K2SiF6:Mn) that emits red light with ions as the emission center. 4+ Phosphor compositions containing (KSF:Mn)) have been developed (see, for example, Patent Documents 1 and 2 and Non-Patent Document 1), and their adoption is progressing rapidly. KSF:Mn has an excitation band at the wavelength of blue light and has a red emission peak with a narrow half-width in a narrow band of 600 to 650 nm.

[0004] In KSF:Mn, the K2SiF6 crystal serves as the framework of the phosphor, and SiF6 2- Si at the hexacoordinate-octahedral sites formed by ions 4+ At the location of, Mn 4+ MnF6 by ion incorporation 2- It forms an octahedral site and acts as a luminescence center.

[0005] However, it has been pointed out that there is a practical problem with this red phosphor containing KSF:Mn, which is that the particle surface becomes blackened when in contact with water or steam under high temperature and high humidity environments. Specifically, on the particle surface of the red phosphor, manganese dioxide is produced when the tetravalent manganese ions constituting the red phosphor react with water, and this manganese dioxide causes absorption of excitation light and suppression of fluorescence, resulting in deterioration of optical properties and a decrease in optical properties (deterioration of durability) over time. Prior art literature

[0006] Japanese Patent Publication No. 2009-528429 WO2015 / 093430 Japanese Patent Publication No. 2018-12813 Japanese Patent Publication No. 2017-141447

[0007] HDNguyen, CCLin, RSLiu, Angew. Chem. Vol. 54, No. 37, pp. 10,866 (2015) RAJAMANI NAGARAJAN, Bull. Mater. Sci., Vol.32, No.6, December 2009, pp.583-587 The problem to be solved

[0008] The present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide a red phosphor with excellent optical properties and durability under high temperature and high humidity environments, and a method for manufacturing the same. means of solving the problem

[0009] The red phosphor according to the present invention is characterized by comprising an Mn-reactivated polyfluoride represented by the following general formula (1) and a perovskite compound represented by the following general formula (2) in order to solve the above problem.

[0010] L2MF6:Mn 4+ (1)

[0011] (In the formula, L represents at least one alkali metal element selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium, and M represents at least one tetravalent element selected from the group consisting of silicon, germanium, tin, titanium, zirconium, and hafnium.)

[0012] ABX3(2)

[0013] (In the formula, A represents at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, silver, indium, gold, thallium, ammonium, primary ammonium, secondary ammonium, tertiary ammonium, and quaternary ammonium. The primary ammonium, secondary ammonium, tertiary ammonium, and quaternary ammonium have an alkyl group having 1 to 10 carbon atoms, or an alkyl group having a heteroatom having 1 to 10 carbon atoms. B represents at least one element selected from the group consisting of magnesium, calcium, barium, zinc, zirconium, strontium, manganese, iron, cobalt, nickel, copper, titanium, vanadium, chromium, mercury, cadmium, tin, lead, strontium, europium, yttrium, beryllium, indium, aluminum, ruthenium, osmium, and antimony.) The above X represents at least one element selected from the group consisting of fluorine, chlorine, bromine, iodine, and sulfur.

[0014] In the above configuration, the perovskite compound represented by the general formula (2) may be attached to at least a portion of the surface of the Mn reactivated polyfluoride represented by the general formula (1) and / or may be present inside.

[0015] In addition, in the above configuration, the Mn reactivated polyfluoride represented by the general formula (1) may be attached to at least a portion of the surface of the perovskite compound represented by the general formula (2) and / or may be present inside.

[0016] In addition, in the above composition, it is preferable that the average particle size D50 of the perovskite compound represented by the above general formula (2) is 0.002 μm to 20 μm in the laser diffraction scattering method.

[0017] In addition, in the above composition, it is preferable that the content ratio of the Mn reactivated polyfluoride represented by the above general formula (1) and the perovskite compound represented by the above general formula (2) be in the range of 10:90 to 99.999:0.001 on a mass basis.

[0018] In the above composition, it is preferable to include a process of contacting an Mn-reactivated polyfluoride represented by the following general formula (1) and a perovskite compound represented by the following general formula (2) in the presence of a solvent.

[0019] The method for manufacturing a red phosphor according to the present invention is characterized by including a process of contacting an Mn-reactivated polyfluoride represented by the following general formula (1) and a perovskite compound represented by the following general formula (2) in the presence of a solvent in order to solve the above problem.

[0020] L2MF6:Mn 4+ (1)

[0021] (In the formula, L represents at least one alkali metal element selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium, and M represents at least one tetravalent element selected from the group consisting of silicon, germanium, tin, titanium, zirconium, and hafnium.)

[0022] ABX3(2)

[0023] (In the formula, A represents at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, silver, indium, gold, thallium, ammonium, primary ammonium, secondary ammonium, tertiary ammonium, and quaternary ammonium. The primary ammonium, secondary ammonium, tertiary ammonium, and quaternary ammonium have an alkyl group having 1 to 10 carbon atoms, or an alkyl group having a heteroatom having 1 to 10 carbon atoms. B represents at least one element selected from the group consisting of magnesium, calcium, barium, zinc, zirconium, strontium, manganese, iron, cobalt, nickel, copper, titanium, vanadium, chromium, mercury, cadmium, tin, lead, strontium, europium, yttrium, beryllium, indium, aluminum, ruthenium, osmium, and antimony.) The above X represents at least one element selected from the group consisting of fluorine, chlorine, bromine, iodine, and sulfur.

[0024] In the above composition, it is preferable that the average particle size D50 of the perovskite compound represented by the above general formula (2) is 0.002 μm to 20 μm in the laser diffraction scattering method.

[0025] In the above composition, it is preferable that the ratio of Mn reactivated polyfluoride to perovskite compound in the red phosphor obtained by contacting the Mn reactivated polyfluoride represented by the above general formula (1) and the perovskite compound represented by the above general formula (2) be in the range of 10:90 to 99.999:0.001 by mass.

[0026] In the above composition, it is preferable that the solvent is water, an organic solvent, a mixed solvent thereof, or an acidic solvent thereof.

[0027] In the above composition, it is preferable that the mixing ratio of the solvent, the Mn reactivated polyfluoride represented by the general formula (1), and the perovskite compound represented by the general formula (2) be in the range of 2:1 to 100:1 by mass.

[0028] In addition, in the above-described composition, the acidic solvent is an acidic solvent containing hydrogen fluoride, and it is preferable that the concentration of the hydrogen fluoride in the acidic solvent containing hydrogen fluoride is in the range of 1 mass% to 70 mass% with respect to the total mass of the acidic solvent. Effects of the invention

[0029] The present invention produces the same effect as described below by means of the means described above.

[0030] That is, according to the red phosphor of the present invention, by the presence of an Mn reactivated hexafluoride and a perovskite compound, Mn 4+ The reaction between the material and water to form colored manganese dioxide is reduced or prevented. As a result, the absorption of excitation light and fluorescence by manganese dioxide, or the decrease in fluorescence emission accompanying the absorption of excitation light, can be prevented, thereby providing a red phosphor with good optical properties, reduced degradation of optical properties due to changes over time in high temperature and high humidity environments, and excellent durability.

[0031] Furthermore, according to the method for manufacturing a red phosphor of the present invention, by contacting a treatment solution containing a perovskite compound with a Mn-reactivated polyfluoride, it is possible to manufacture a red phosphor comprising a Mn-reactivated polyfluoride and a perovskite compound. As a result, it is possible to manufacture a red phosphor with good optical properties, reduced degradation of optical properties due to changes over time in high temperature and high humidity environments, and excellent durability. Brief explanation of the drawing

[0032] Figure 1 is a graph showing the X-ray diffraction pattern of KMgF3 according to Example 1 of the present invention. Figure 2 is an SEM image of KMgF3 according to Example 1 of the present invention. Figure 3 is a graph showing the X-ray diffraction pattern of a red phosphor according to Example 1 of the present invention. Figure 4 is an SEM image of a red phosphor according to Example 1 of the present invention. Specific details for implementing the invention

[0033] (Red fluorescent material)

[0034] The red phosphor according to the present embodiment is described below.

[0035] The red phosphor according to the present embodiment comprises an Mn-reactivated polyfluoride represented by the following general formula (1) (hereinafter referred to as "Mn-reactivated polyfluoride") and a perovskite compound represented by the following general formula (2) (hereinafter referred to as "perovskite compound").

[0036] L2MF6:Mn 4+ (1)

[0037] (In the formula, L represents at least one alkali metal element selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium, and M represents at least one tetravalent element selected from the group consisting of silicon, germanium, tin, titanium, zirconium, and hafnium.)

[0038] ABX3(2)

[0039] (In the formula, A represents at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, silver, indium, gold, thallium, ammonium, primary ammonium, secondary ammonium, tertiary ammonium, and quaternary ammonium. The primary ammonium, secondary ammonium, tertiary ammonium, and quaternary ammonium have an alkyl group having 1 to 10 carbon atoms, or an alkyl group having a heteroatom having 1 to 10 carbon atoms. B represents at least one element selected from the group consisting of magnesium, calcium, barium, zinc, zirconium, strontium, manganese, iron, cobalt, nickel, copper, titanium, vanadium, chromium, mercury, cadmium, tin, lead, strontium, europium, yttrium, beryllium, indium, aluminum, ruthenium, osmium, and antimony.) The above X represents at least one element selected from the group consisting of fluorine, chlorine, bromine, iodine, and sulfur.

[0040] The red phosphor of the present embodiment may be a single red phosphor or a mixture of two or more types of red phosphors.

[0041] The general formula L2MF6:Mn representing the above Mn reactivated diofluoride 4+ In this, "L2MF6" represents the composition of the matrix crystal of the red phosphor. Also, "Mn 4+ 」 represents a reactivated ion that becomes the center of luminescence.

[0042] Here, in this specification, "revitalization" refers to the use of an revitalizing agent, Mn, with respect to the parent crystal L2MF6 in order to induce fluorescence. 4+ It means adding. In its revived form, Mn 4+ Examples include a form in which is partially substituted with any atom constituting L2MF6. In the case of the present embodiment, Mn 4+ It is desirable that it substitutes M of the parent crystal.

[0043] General formula L2MF6:Mn4+ As an Mn regenerated polyfluoride represented by, specifically, for example, Li2SiF6:Mn 4+ , Na2SiF6:Mn 4+ , K2SiF6:Mn 4+ , Rb2SiF6:Mn 4+ , Cs2SiF6:Mn 4+ , Li2GeF6:Mn 4+ , Na2GeF6:Mn 4+ , K2GeF6:Mn 4+ , Rb2GeF6:Mn 4+ , Cs2GeF6:Mn 4+ , Li2SnF6:Mn 4+ , Na2SnF6:Mn 4+ , K2SnF6:Mn 4+ , Rb2SnF6:Mn 4+ , Cs2SnF6:Mn 4+ , Li2TiF6:Mn 4+ , Na2TiF6:Mn 4+ , K2TiF6:Mn 4+ , Rb2TiF6:Mn 4+ , Cs2TiF6:Mn 4+ , Li2ZrF6:Mn 4+ , Na2ZrF6:Mn 4+ , K2ZrF6:Mn 4+ , Rb2ZrF6:Mn 4+ , Cs2ZrF6:Mn 4+ , Li2HfF6:Mn 4+ , Na2HfF6:Mn 4+ , K2HfF6:Mn 4+ , Rb2HfF6:Mn 4+ , Cs2HfF6:Mn 4+ Examples include the above. Among these Mn-revived polyfluorides, in terms of ease of availability and ease of synthesis, K2SiF6:Mn 4+ , K2TiF6:Mn 4+ , K2GeF6:Mn 4+ , Na2SiF6:Mn 4+ , Na2TiF6:Mn 4+ , Na2GeF6:Mn 4+It is desirable, and K2SiF6:Mn 4+ , K2TiF6:Mn 4+ ...is more desirable. Furthermore, Mn-reactivated bifluorides can be selected according to the optical properties required for various applications. Therefore, they are not specifically limited to the Mn-reactivated bifluorides exemplified.

[0044] Here, in this specification, "optical properties" refers to the absorption rate and internal quantum efficiency of a red phosphor, etc. "Absorption rate" refers to the efficiency of a red phosphor absorbing excitation light. For example, when the peak value of the spectral radiance of excitation light (wavelength 449 nm) irradiated from a blue LED is set to Ex1 and the peak value of the excitation light not absorbed by the red phosphor is set to Ex2, the absorption rate α is expressed by the following formula (1).

[0045] Absorption rate α(%)=(Ex1-Ex2) / Ex1×100 (1)

[0046] In addition, "internal quantum efficiency" refers to the efficiency of converting the excitation light absorbed by the red phosphor into fluorescence. For example, when the peak value of the spectral radiance of the red phosphor's fluorescence under irradiation with excitation light (wavelength 449 nm) from a blue LED is Ex2, the internal quantum efficiency η is expressed by the following formula (2).

[0047] Internal quantum efficiency η(%)=Em / (Ex1-Ex2)×100 (2)

[0048] It is preferable that the Mn-reactivated polyfluoride be solid and further particulate. If the Mn-reactivated polyfluoride is particulate, its average particle size is not particularly limited, as long as the ratio of scattering to absorption and conversion with respect to excitation light does not become too large, and no problems arise when mixing with resin for mounting on an LED device.

[0049] The molar ratio of Mn is preferably in the range of 0.005 to 0.15 with respect to the total moles of M and Mn in the red phosphor (or Mn regenerated polyfluoride), more preferably in the range of 0.01 to 0.12, and particularly preferably in the range of 0.02 to 0.1. By making the molar ratio 0.005 or higher, good luminescence intensity of the red phosphor can be maintained. On the other hand, by making the molar ratio 0.15 or lower, the durability of the red phosphor under high temperature and high humidity environments can be suppressed from deteriorating too much.

[0050] In addition, in this specification, "durability" refers to the degree to which the initial optical properties of a red phosphor are maintained when the red phosphor is stored for a certain period of time in a high-temperature and high-humidity environment. The meaning of optical properties is as described above.

[0051] 일반식 ABX3으로 표시되는 페로브스카이트 화합물로서는, 구체적으로는, 예를 들어 LiBaF3, LiMgF3, LiMnF3, LiFeF3, LiCoF3, LiNiF3, LiCuF3, NaCaF3, NaMgF3, NaZnF3, NaZrF3, NaMnF3, NaFeF3, NaCoF3, NaNiF3, NaCuF3, NaTiF3, NaSnF3, NaBeF3, KCaF3, KBaF3, KMgF3, KZnF3, KZrF3, KMnF3, KFeF3, KCoF3, KNiF3, KCuF3, KTiF3, KHgF3, KCdF3, KSnF3, KPbF3, KSrF3, RbCaF3, RbBaF3, RbMgF3, RbZnF3, RbZrF3, RbFeF3, RbNiF3, RbTiF3, RbHgF3, RbCdF3, RbSnF3, RbPbF3, RbSrF3, CsCaF3, CsBaF3, CsZnF3, CsZrF3, CsFeF3, CsCuF3, CsTiF3, CsVF3, CsCrF3, CsHgF3, CsCdF3, CsSrF3, InCaF3, InMgF3, InZnF3, InCdF3, InOsF3, AuBaF3, AuMgF3, AuZnF3, TlCaF3, TlMgF3, TlZnF3, TlZrF3, TlNiF3, TlTiF3, TlVF3, TlHgF3, TlCdF3, TlSnF3, TlPbF3, TlOsF3, AgMgF3, AgZnF3, AgZrF3, AgFeF3, AgTiF3, AgVF3, AgCrF3, AgCdF3, XeScF3, HgScF3, HgYF3, HgInF3, GaMgF3, GaZnF3, GaRuF3, ZnScF3, ZnYF3, ZnInF3, ZnAlF3, CdScF3, CdYF3, CdSbF3, BaCuF3, AlMgF3, AlZnF3, AlFeF3, BeScF3, BeYF3, BeAlF3, PdScF3, PdYF3, NH4MgF3, NaMgCl3, KMgCl3, RbMgCl3, CsMgCl3, InMgCl3, NaZnCl3, KZnCl3, RbZnCl3, InZnCl3,Examples include RbHgCl3, RbTiCl3, TlCaCl3, TlHgCl3, RbCaBr3, CsCaBr3, TlCaBr3, RbHgBr3, CsEuBr3, CsCaI3, CsHgI3, CaZrS3, BaZrS3, etc. Among these perovskite compounds, from the perspective of ease of availability and ease of synthesis, NaCaF3, KCaF3, NaFeF3, KFeF3, NaNiF3, KNiF3, NaZnF3, NaZrF3, KZnF3, KZrF3, NaMgF3, and KMgF3 are preferred, and NaMgF3 and KMgF3 are more preferred.

[0052] In addition, in the case where A in general formula (2) is a primary ammonium, a secondary ammonium, a tertiary ammonium, or a quaternary ammonium, A has an alkyl group having 1 to 10 carbon atoms, preferably 1 to 6, and more preferably 1 to 5 carbon atoms. Or, A has an alkyl group having heteroatoms, in the range of 1 to 10 carbon atoms, preferably 1 to 6, and more preferably 1 to 5 carbon atoms. Also, in this specification, "heteroatoms" means atoms such as oxygen, nitrogen, and sulfur. Also, when a range of carbon atoms is indicated in this specification, the range means that it includes all integer carbon atoms included in the said range. Accordingly, for example, an alkyl group having "1 to 3 carbon atoms" means all alkyl groups having 1, 2, and 3 carbon atoms.

[0053] Here, when M in the Mn-reactivated polyfluoride is any one of silicon, germanium, tin, titanium, and zirconium, a combination in which B in the perovskite compound is any one of magnesium, calcium, zinc, iron, nickel, and titanium is preferred. Furthermore, when M in the Mn-reactivated polyfluoride is silicon, it is even more preferable that B in the perovskite compound is magnesium.

[0054] In addition, perovskite compounds can be selected based on the durability required for various applications. Therefore, they are not specifically limited to the perovskite compounds exemplified.

[0055] The content ratio of Mn-reactivated polyfluoride to perovskite compound is preferably in the range of 10:90 to 99.999:0.001 by mass, more preferably in the range of 10:90 to 99.99:0.01, and particularly preferably in the range of 15:85 to 99.97:0.03. By making the content ratio of Mn-reactivated polyfluoride to perovskite compound 10:90 or higher, the optical properties of the red phosphor can be maintained in good condition. On the other hand, by making the content ratio of Mn-reactivated polyfluoride to perovskite compound 99.999:0.001 or lower, the optical properties and durability of the red phosphor under high temperature and high humidity environments can be further improved.

[0056] The (initial) absorption rate of the red phosphor is preferably within the range of 30% to 100%, more preferably within the range of 40% to 100%, and even more preferably within the range of 50% to 100%. By making the absorption rate 30% or higher, the optical properties of the red phosphor can be maintained in good condition. In particular, in the present invention, since the decrease in the absorption of excitation light by the red phosphor is suppressed even after storage for a certain period of time in a high-temperature and high-humidity environment, the maintenance of good optical properties is ensured. Furthermore, the numerical range of the absorption rate is suitable not only for the initial absorption rate of the red phosphor but also for the absorption rate after the red phosphor has been stored for a certain period in a high-temperature and high-humidity environment. The definition of the absorption rate is as described above.

[0057] The (initial) internal quantum efficiency of the red phosphor is preferably within the range of 60% to 100%, more preferably within the range of 75% to 100%, and even more preferably within the range of 80% to 100%. By making the internal quantum efficiency 70% or higher, the luminescence efficiency of the red phosphor can be maintained in good condition. Furthermore, the numerical range of the internal quantum efficiency is suitable not only for the initial internal quantum efficiency of the red phosphor but also for the internal quantum efficiency after storing the red phosphor in a high-temperature and high-humidity environment for a certain period. The definition of internal quantum efficiency is as described above.

[0058] In the red phosphor of the present embodiment, the Mn reactivated hexafluoride and the perovskite compound can be present in various forms.

[0059] For example, a perovskite compound can be present on at least a portion of the surface of Mn reactivated polyfluoride. It is believed that the tetravalent manganese ions constituting Mn reactivated polyfluoride react with water to produce colored manganese dioxide, causing black spots on the Mn reactivated polyfluoride. It is speculated that under high temperature and high humidity conditions, the occurrence of these black spots accelerates, leading to the deterioration of the optical properties and reduced durability of the red phosphor. However, by presenting a perovskite compound on at least a portion of the surface of Mn reactivated polyfluoride, the reaction of tetravalent manganese ions upon contact with water can be reduced or prevented. In particular, when the perovskite compound covers the entire surface of the Mn reactivated polyfluoride as a coating layer, it suppresses the penetration of moisture or water vapor into the red phosphor, thereby promoting improved durability and optical properties under high temperature and high humidity environments.

[0060] From the perspective of preventing the formation of manganese dioxide, it is desirable for a perovskite compound to exist as a coating layer over the entire surface of the Mn-reactivated polyfluoride. However, having a perovskite compound covering the entire surface of the Mn-reactivated polyfluoride may not be industrially suitable in terms of manufacturing costs and ease of manufacturing. According to the results of the inventors' careful investigation, it was found that even when a perovskite compound is present on a part of the surface of the Mn-reactivated polyfluoride, it is not necessary to cover the entire surface of the Mn-reactivated polyfluoride, as this improves durability and optical properties under high temperature and high humidity environments. Although the reason for this has not yet been revealed, it is thought that in the manufacturing process of the red phosphor of the present invention, passing through a three-phase interface comprising a perovskite compound formed on the surface of the red phosphor, the Mn-reactivated polyfluoride, and a reaction solution / treatment solution is involved. In other words, when the reaction / treatment solution is removed by distillation, a phenomenon may occur in which perovskite compounds present in small amounts within it are deposited extremely thinly on the surface layer of the Mn-reactivated polyfluoride, for example, at the molecular level. Furthermore, in harsh environments such as high temperature and high humidity, the adsorption layer of water molecules on the surface of the Mn-reactivated polyfluoride can be regarded as the reaction / treatment solution; it is also thought that the perovskite compounds present on a portion of the surface of the Mn-reactivated polyfluoride act as a reservoir, and it is believed that durability is improved under high temperature and high humidity environments even without covering the entire surface of the Mn-reactivated polyfluoride.

[0061] In addition, the perovskite compound may exist inside the Mn-reduced complex fluoride. By doing so, the perovskite compound existing inside causes scattering of the excitation light, and Mn 4+ It increases the opportunity for contact with ions and contributes to the improvement of optical properties, particularly absorption rate.

[0062] In addition, Mn reactivated hexafluoride may be present on at least a portion of the surface of the perovskite compound. In this form of existence, since the perovskite compound contains optically non-problematic components, Mn, which is the luminescent ion of the red phosphor, 4+ The amount of Mn-reactivated polyfluoride containing [the substance] can be reduced, and this can contribute to reducing the cost of phosphor raw materials used in light-emitting devices such as LEDs, lighting fixtures, and image display devices.

[0063] In addition, the Mn-reactivated complex fluoride may be present inside the perovskite compound. This prevents the tetravalent manganese ions from coming into contact with water or water vapor, and further prevents the formation of manganese dioxide. As a result, the durability of the red phosphor under high temperature and high humidity environments can be further improved.

[0064] The red phosphor of the present embodiment is preferably a solid and further in the form of particles. When the red phosphor is in the form of particles, its average particle size is not particularly limited as long as the ratio of scattering to absorption and conversion with respect to excitation light does not become too large, and there is no problem when mixing with resin, etc., since it is mounted on an LED device.

[0065] The red phosphor of the present embodiment is suitable, for example, as a red phosphor for a white LED using blue light as a light source. The red phosphor of the present embodiment can be suitably used in light-emitting devices such as lighting fixtures and image display devices.

[0066] (Method for manufacturing red phosphor)

[0067] Next, a method for manufacturing a red phosphor according to the present embodiment is described below.

[0068] One aspect of the method for manufacturing a red phosphor according to the present embodiment may include, for example, a method comprising at least a process of contacting a Mn reactivated polyfluoride and a perovskite compound in the presence of a solvent. With this method, it is possible to manufacture a red phosphor in which the perovskite compound is present on at least a portion of the surface of the Mn reactivated polyfluoride, or a red phosphor in which the Mn reactivated polyfluoride is present on at least a portion of the surface of the perovskite compound.

[0069] Examples of solvents include water, organic solvents, mixtures thereof, or acidic solvents thereof. Among these solvents, the complete use of Mn-reactivated polyfluoride can drastically reduce the yield of the red phosphor. Therefore, from the perspective of improving productivity, it is desirable to select a solvent that does not allow for the complete use of Mn-reactivated polyfluoride.

[0070] Examples of organic solvents among such solvents include methyl alcohol, ethyl alcohol, isopropyl alcohol, isobutyl alcohol, acetone, methyl acetate, ethyl acetate, tetrahydrofuran, 1,2-dimethoxyethane, etc. Among these organic solvents, methyl alcohol, ethyl alcohol, isopropyl alcohol, isobutyl alcohol, and acetone are preferred from the perspective of ease of availability and convenience of the working environment, and ethyl alcohol, isopropyl alcohol, and acetone are particularly preferred.

[0071] In addition, among such solvents, acidic solvents (i.e., solvents containing acids having protons) include, for example, hydrogen fluoride, nitric acid, sulfuric acid, hydrochloric acid, and hydrosilicofluoric acid. From the perspective of the manufacturing process or the characteristics of the red phosphor, hydrogen fluoride, nitric acid, and hydrosilicofluoric acid are preferred, and hydrogen fluoride is particularly preferred.

[0072] The amount of perovskite compound added is preferably appropriately set so that the ratio of Mn reactivated polyfluoride to perovskite compound in the red phosphor obtained by the manufacturing method of the present embodiment is within the following range. That is, the ratio of Mn reactivated polyfluoride to perovskite compound is preferably in the range of 10:90 to 99.999:0.001 by mass, more preferably in the range of 10:90 to 99.99:0.01, and particularly preferably in the range of 15:85 to 99.97:0.03. By making the ratio of Mn reactivated polyfluoride to perovskite compound 99.999:0.001 or less, the optical properties of the red phosphor can be maintained in good condition. Meanwhile, by increasing the content ratio of Mn-reactivated polyfluoride and perovskite compound to 10:90 or higher, the optical properties and durability of the red phosphor under high temperature and high humidity environments can be further improved.

[0073] The mixing ratio of the solvent, Mn reactivated polyfluoride, and perovskite compound can be appropriately adjusted within a range that does not affect subsequent stirring or filtration (details of stirring and filtration will be described later). Specifically, the mixing ratio of the two is preferably in the range of 2:1 to 100:1 by mass, more preferably in the range of 3:1 to 50:1, and particularly preferably in the range of 3:1 to 10:1. By making the mixing ratio 100:1 or less, the amount of solvent discharged as waste liquid can be reduced, and the environmental burden can be reduced. On the other hand, by making the mixing ratio 2:1 or more, the dispersibility of the Mn reactivated polyfluoride and perovskite compound in the solvent can be improved, thereby preventing the Mn reactivated polyfluoride and perovskite compound from existing unevenly.

[0074] In addition, when using an acidic solvent containing hydrogen fluoride, namely hydrofluoric acid or a mixed solvent of said hydrofluoric acid and an organic solvent, as a solvent, the concentration of hydrogen fluoride is preferably in the range of 1 mass% to 70 mass% with respect to the total mass of said acidic solvent, more preferably in the range of 5 mass% to 60 mass%, and particularly preferably in the range of 10 mass% to 50 mass%. By setting the concentration of hydrogen fluoride to 70 mass% or less, the solubility of Mn reactivated complex fluoride in the acidic solvent containing hydrogen fluoride can be reduced, and the reduction in the yield of red phosphor can be suppressed. On the other hand, by setting the concentration of hydrogen fluoride to 1 mass% or more, the increase in the amount of acidic solvent used can be suppressed, and productivity can be improved.

[0075] The method of contacting the Mn-reactivated polyfluoride and the perovskite compound in the presence of a solvent is not particularly limited, and examples include immersion (injection, addition) or spraying methods. In the former case, for example, the Mn-reactivated polyfluoride and the perovskite compound are injected (immersed) into the solvent in any order or simultaneously. By doing so, a suspension in which the Mn-reactivated polyfluoride and the perovskite compound are dispersed in the solvent is obtained. The number of injections is not particularly limited, and in addition to injecting the Mn-reactivated polyfluoride and the perovskite compound into the solvent at once, injections may be performed multiple times. In the latter case, for example, a solvent containing the perovskite compound is sprayed onto the Mn-reactivated polyfluoride. The amount of the sprayed solvent containing the perovskite compound is not particularly limited and can be set appropriately. In addition, after spraying the Mn-reactivated polyfluoride with a solvent containing a perovskite compound, it is desirable to remove the solvent remaining on the surface of the Mn-reactivated polyfluoride by distillation. The method of distillation removal is not particularly limited, and, for example, the drying process described below may be performed. From the perspective of industrially manufacturing a red phosphor, a method of introducing (immersing) the Mn-reactivated polyfluoride and the perovskite compound into a solvent is preferred.

[0076] When the contact process between the above-mentioned Mn-activated polyfluoride and the perovskite compound is carried out by the above-mentioned immersion method, it is preferable to sequentially perform a stirring process for stirring the obtained suspension, a solid-liquid separation process of the suspension, a washing process of the solid separated from the liquid, and a solid drying process after washing, after the contact process.

[0077] The stirring method in the above stirring process is not particularly limited and can be performed using known stirring devices. The stirring time of the suspension is not particularly limited and can be appropriately adjusted based on the efficiency of the manufacturing equipment. The stirring speed is also not particularly limited and can be set appropriately as needed.

[0078] The above solid-liquid separation process is a process for separating dispersed solid particles from a suspension after a stirring process. The method of solid-liquid separation is not particularly limited; examples include filtering the suspension, or settling or centrifuging the suspension to precipitate the dispersed solid particles, followed by decantation. The settling time of the suspension, the number of centrifugations, and the time are not particularly limited and must be sufficient to allow the solid particles to settle sufficiently.

[0079] The above washing process is performed to wash the cake obtained by solid-liquid separation. In this washing process, water, organic solvents, a mixture of solvents thereof, or acidic solvents thereof may be used as washing agents. The washing time or the number of washes is not particularly limited and can be set appropriately as needed.

[0080] The organic solvent used in the cleaning process is not particularly limited, and examples include methyl alcohol, ethyl alcohol, isopropyl alcohol, isobutyl alcohol, acetone, methyl acetate, ethyl acetate, tetrahydrofuran, 1,2-dimethoxyethane, etc. From the perspective of ease of availability and simplicity of the working environment, methyl alcohol, ethyl alcohol, isopropyl alcohol, isobutyl alcohol, and acetone are preferred, and ethyl alcohol, isopropyl alcohol, and acetone are particularly preferred.

[0081] In addition, the acidic solvent used in the cleaning process refers to a solution containing an acid having protons. The acid having protons is not particularly limited and may include, for example, hydrogen fluoride, nitric acid, sulfuric acid, hydrochloric acid, silicofluoric acid, etc. The content of the acid having protons is preferably in the range of 0.1 mass% to 70 mass% with respect to the total mass of the acidic solvent, more preferably in the range of 1 mass% to 55 mass%, and particularly preferably in the range of 5 mass% to 50 mass%.

[0082] The above drying process is performed on the cake after the washing process. By doing so, solvent residues remaining in the cake or cleaning agents used in the washing process can be removed by distillation. The drying method is not particularly limited and may include, for example, heat drying or hot air drying. In the case of heat drying, it is preferable to perform the process under a nitrogen gas atmosphere. The drying temperature is preferably in the range of 60°C to 200°C, more preferably in the range of 70°C to 150°C, and particularly preferably in the range of 80°C to 110°C. By setting the drying temperature to 60°C or higher, good drying efficiency can be maintained. Furthermore, the retention of impurities can be prevented, and the degradation of the optical properties of the red phosphor caused by the retention of said impurities can be suppressed. On the other hand, by setting the drying temperature to 200°C or lower, the deterioration of the obtained red phosphor due to heat can be prevented. Additionally, in the case of heat drying, the drying time is preferably in the range of 0.5 hours to 20 hours, and more preferably in the range of 2 hours to 15 hours. By making the drying time 0.5 hours or more, the retention of impurities can be prevented, and the degradation of the optical properties of the red phosphor caused by the retention of said impurities can be suppressed. On the other hand, by making the drying time 20 hours or less, the decrease in the production efficiency of the red phosphor can be prevented.

[0083] By the above, it is possible to manufacture a red phosphor in which a perovskite compound is present on at least a portion of the surface of an Mn regenerated polyfluoride, or a red phosphor in which an Mn regenerated polyfluoride is present on at least a portion of the surface of a perovskite compound.

[0084] In addition, as another aspect of the method for manufacturing a red phosphor according to the present embodiment, for example, a method of adding a perovskite compound during the process of manufacturing a Mn-reactivated polyfluoride can be cited. With this method, a red phosphor in which the perovskite compound is present inside the Mn-reactivated polyfluoride, or a red phosphor in which the Mn-reactivated polyfluoride is present inside the perovskite compound, can be manufactured.

[0085] For example, first, a perovskite compound is dissolved or dispersed in a hydrogen fluoride solution in which Mn reactivated polyfluoride is dissolved. Subsequently, a solid material that does not contain element Mn is added to the hydrogen fluoride solution containing Mn reactivated polyfluoride and the perovskite compound. As a result, the solubility of Mn reactivated polyfluoride decreases with the dissolution of the solid material, causing Mn reactivated polyfluoride to precipitate. Then, as a result of introducing the perovskite compound during the precipitation process of Mn reactivated polyfluoride, a red phosphor in which the perovskite compound exists inside the Mn reactivated polyfluoride can be produced. Alternatively, a raw material containing elements L, M, and Mn is dissolved or dispersed in a hydrogen fluoride solution. Subsequently, a solution in which the perovskite compound is dissolved is added to the hydrogen fluoride solution containing said raw material. By doing so, a red phosphor in which Mn reactivated polyfluoride exists inside the perovskite compound can be produced. The ratio of Mn-activated polyfluoride to perovskite compound is not specifically limited and can be appropriately set according to the amount of raw material used, the application of the red phosphor, and the performance requirements for said application.

[0086] (Other matters)

[0087] The method for manufacturing Mn-reactivated polyfluoride, which is a raw material for red phosphors, is not particularly limited, and known methods may be employed. For example, a method of dissolving a compound containing the constituent elements of Mn-reactivated polyfluoride in a hydrofluoric acid solution, mixing them, and reacting to precipitate (see HDNguyen, CCLin, RSLiu, Angew. Chem. Vol. 54, No. 37, p. 10866 (2015)); a method of dissolving or dispersing all of the compounds containing the constituent elements of Mn-reactivated polyfluoride in a hydrofluoric acid solution and precipitating them by evaporation and concentration (see Japanese Patent Publication No. 2009-528429); a method of sequentially dissolving compounds containing the constituent elements of Mn-reactivated polyfluoride in a hydrofluoric acid solution, adding one of the manganese-free constituent elements of the solid Mn-reactivated polyfluoride to it, and K2SiF6:Mn 4+ Examples include a method of precipitating crystals and filtering and drying (see WO2015 / 093430).

[0088] Examples

[0089] The present invention will be described in detail below using examples, but the present invention is not limited to the following examples without departing from the gist thereof.

[0090] (Creation of Mn Resurrection Reverse Cargo)

[0091] Based on the method described in HDNguyen, CCLin, RSLiu, Angew. Chem. Vol. 54, No. 37, p. 10866 (2015), Mn-reactivated polyfluoride was synthesized by the following method.

[0092] First, 35 ml of a 48 mass% hydrofluoric acid solution was added to a PFA container with a volume of 0.1 L. Then, 1.2 g of SiO2 was added and dissolved while stirring the hydrofluoric acid solution. In addition, 0.3 g of K2MnF6 was added and dissolved in this solution.

[0093] Next, 3.5 g of KF was slowly added to the above solution over a period of 15 minutes to obtain a crystal. This crystal was washed with a 20 mass% hydrofluoric acid solution and acetone, and then dried at 70°C for 6 hours. By doing so, K2SiF6:Mn was obtained as a Mn-reactivated polyfluoride. 4+ I obtained.

[0094] (Example 1)

[0095] Magnesium potassium fluoride was synthesized by the following method in accordance with the method described in RAJAMANI NAGARAJAN, Bull. Mater. Sci., Vol. 32, No.6, December 2009, pp.583-587.

[0096] First, 10 g of magnesium chloride was added and dissolved in 100 mL of anhydrous methanol (dehydration solvent). 18.3 g of potassium fluoride was added to the solution. The molar ratio of potassium fluoride to magnesium chloride was adjusted to 3:1. In addition, the obtained solution was stirred for 120 minutes, then filtered, and the filtrate was washed with ethanol. After washing, the filtrate was also washed with acetone. The obtained solid was dried under a nitrogen atmosphere at a drying temperature of 105°C. By this, 11.5 g of a white solid (perovskite compound) was obtained.

[0097] The obtained white solid was analyzed by X-ray diffraction (XRD), and as shown in Fig. 1, a peak matching the reference (ICSD-56096) of potassium magnesium fluoride (KMgF3) was observed. Fig. 1 is a graph showing the X-ray diffraction pattern of KMgF3 of Example 1. In addition, the white solid was observed using a scanning electron microscope (SEM). As a result, as shown in Fig. 2, it was confirmed from the observation image that it has a cubic crystal structure of 1 μm. In addition, Fig. 2 is an SEM image of the white solid.

[0098] Next, 2 g of potassium magnesium fluoride (KMgF3) was added to 73 g of isopropyl alcohol as a solvent, and a suspension was prepared by stirring for 5 minutes. In addition, while stirring this suspension, the aforementioned K2SiF6:Mn 4+ 20g of was added and stirred for 10 minutes.

[0099] After stirring was finished, the suspension was allowed to stand for 10 minutes to precipitate the dispersed solids. Subsequently, the filtrate was recovered by suction filtration. In addition, isopropyl alcohol was added to the filtrate, and the supernatant was removed by suction filtration again; this operation was repeated to wash the filtrate. The washed filtrate was recovered and dried under a nitrogen atmosphere at a drying temperature of 105°C to evaporate the isopropyl alcohol.

[0100] Based on the above, a red phosphor according to Example 1 was prepared. The obtained red phosphor was analyzed by X-ray diffraction (XRD), and as shown in Fig. 3, peaks matching the reference (ICSD-29407) of K2SiF6, the parent crystal of Mn reactivated polyfluoride, and the reference (ICSD-56096) of magnesium potassium fluoride were observed. Fig. 3 is a graph showing the X-ray diffraction pattern of the red phosphor of Example 1. In addition, the red phosphor was observed using a scanning electron microscope (SEM). As a result, as shown in Fig. 4, it was confirmed that KMgF3 having a cubic crystal structure of 1 μm was attached to the surface of the Mn reactivated polyfluoride. In addition, Fig. 4 is an SEM image of the red phosphor.

[0101] (Example 2)

[0102] In this embodiment, the isopropyl alcohol used in Example 1 was changed to pure water. Except for that, a red phosphor according to Example 2 was prepared in the same manner as in Example 1.

[0103] (Example 3)

[0104] In this embodiment, the isopropyl alcohol used in Example 1 was changed to hydrofluoric acid with a concentration of 1 mass%. Except for that, the red phosphor according to Example 3 was prepared in the same manner as in Example 1.

[0105] (Example 4)

[0106] In this embodiment, the isopropyl alcohol used in Example 1 was changed to hydrofluoric acid with a concentration of 43 mass%. In addition, the amount of potassium magnesium fluoride added was changed from 2 g to 0.12 g. Except for these changes, the red phosphor according to Example 4 was prepared in the same manner as in Example 1.

[0107] (Example 5)

[0108] In this embodiment, the isopropyl alcohol used in Example 1 was changed to hydrofluoric acid with a concentration of 43 mass%. In addition, the amount of potassium magnesium fluoride added was changed from 2 g to 0.02 g. Except for these changes, the red phosphor according to Example 5 was prepared in the same manner as in Example 1.

[0109] (Example 6)

[0110] In this embodiment, the perovskite compound was changed from potassium magnesium fluoride to sodium magnesium fluoride (NaMgF3). Except for these changes, the red phosphor according to Example 6 was prepared in the same manner as in Example 4.

[0111] (Comparative Example 1)

[0112] In this comparative example, the aforementioned K2SiF6:Mn 4+ It was used as a red phosphor.

[0113] (Evaluation of red phosphor)

[0114] For the red phosphors of Examples 1 to 6 and Comparative Example 1, each evaluation was performed using the method described below.

[0115] Evaluation of Optical Properties of Red Phosphors

[0116] To evaluate the optical properties of each red phosphor of Examples 1 to 6 and Comparative Example 1, the absorption rate and internal quantum efficiency of each were calculated.

[0117] The absorption rate and internal quantum efficiency were measured using a quantum efficiency measurement system (product name: QE-2000, manufactured by Otsuka Denshi Co., Ltd.). Specifically, samples of the red phosphors of Examples 1 to 6 and Comparative Example 1 were each filled into a cell for measuring the powder and measured. As a result, the absorption rates of the red phosphors for Examples 1 to 6 were 62%, 68%, 67%, 72%, 73%, and 72%, respectively, and the internal quantum efficiency was 90% for all of them. Meanwhile, the absorption rate of the red phosphor for Comparative Example 1 was 72%, and the internal quantum efficiency was 90%.

[0118] Evaluation of the Durability of Red Phosphors

[0119] Durability tests were performed as follows. First, 0.3 g of the red phosphor of Examples 1 to 6 or Comparative Example 1 was placed in a PFA tray, set in a constant temperature and humidity chamber controlled at a temperature of 85°C and a relative humidity of 85%, and stored for 64 hours and 232 hours, respectively. Afterward, the absorption rate and internal quantum efficiency were determined by the method described above.

[0120] In addition, based on the following formula (3), the durability index of the red phosphor under high temperature and high humidity environments was calculated from the measured values ​​of internal quantum efficiency before and after the durability test of each red phosphor. The results are shown in Table 1.

[0121] (Indicator of durability) = (Internal quantum efficiency after durability test) / (Internal quantum efficiency before durability test) × 100 (3)

[0122] In addition, the term “after durability test” in formula (3) refers to the case after 64 hours of storage and 232 hours of storage in an environment with a temperature of 85°C and a relative humidity of 85%.

[0123] (result)

[0124] As shown in Table 1, it was confirmed that the red phosphors of Examples 1 to 6, in which a perovskite compound is present on the surface of an Mn-reactivated complex fluoride, have a lower rate of change under high temperature and high humidity environments and improved durability compared to the red phosphor of Comparative Example 1, which does not contain a perovskite compound.

[0125]

Claims

Claim 1 A red phosphor comprising a Mn reactivated polyfluoride represented by the following general formula (1) and a perovskite compound represented by the following general formula (2), wherein the perovskite compound is in particulate form and is attached to the surface of the Mn reactivated polyfluoride such that a portion of the surface of the Mn reactivated polyfluoride is exposed, and the average particle size D50 of the perovskite compound is 0.002 μm to 20 μm in laser diffraction scattering. L2MF6:Mn 4+ (1) (In the formula, L represents at least one alkali metal element selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium, and M represents at least one tetravalent element selected from the group consisting of silicon, germanium, tin, titanium, zirconium, and hafnium.) ABX3(2) (In the formula, A represents at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, silver, indium, gold, thallium, ammonium, primary ammonium, secondary ammonium, tertiary ammonium, and quaternary ammonium. The primary ammonium, the secondary ammonium, the tertiary ammonium, and the quaternary ammonium have an alkyl group having 1 to 10 carbon atoms, or an alkyl group having a heteroatom with a carbon number in the range of 1 to 10 carbon atoms. B represents magnesium, calcium, barium, zinc, It represents at least one element selected from the group consisting of zirconium, strontium, manganese, iron, cobalt, nickel, copper, titanium, vanadium, chromium, mercury, cadmium, tin, lead, strontium, europium, yttrium, beryllium, indium, aluminum, ruthenium, osmium, and antimony. The above X represents at least one element selected from the group consisting of fluorine, chlorine, bromine, iodine, and sulfur.) Claim 2 In claim 1, the red phosphor is a perovskite compound represented by the general formula (2) that exists inside the Mn regenerated polyfluoride represented by the general formula (1). Claim 3 A red phosphor comprising an Mn reactivated polyfluoride represented by the following general formula (1) and a perovskite compound represented by the following general formula (2), wherein the Mn reactivated polyfluoride represented by the general formula (1) is attached to at least a portion of the surface of the perovskite compound represented by the general formula (2) and / or is present inside, and the average particle size D50 of the perovskite compound is 0.002 μm to 20 μm in laser diffraction scattering. L2MF6:Mn 4+ (1) (In the formula, L represents at least one alkali metal element selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium, and M represents at least one tetravalent element selected from the group consisting of silicon, germanium, tin, titanium, zirconium, and hafnium.) ABX3(2) (In the formula, A represents at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, silver, indium, gold, thallium, ammonium, primary ammonium, secondary ammonium, tertiary ammonium, and quaternary ammonium. The primary ammonium, the secondary ammonium, the tertiary ammonium, and the quaternary ammonium have an alkyl group having 1 to 10 carbon atoms, or an alkyl group having a heteroatom with a carbon number in the range of 1 to 10 carbon atoms. B represents magnesium, calcium, barium, zinc, It represents at least one element selected from the group consisting of zirconium, strontium, manganese, iron, cobalt, nickel, copper, titanium, vanadium, chromium, mercury, cadmium, tin, lead, strontium, europium, yttrium, beryllium, indium, aluminum, ruthenium, osmium, and antimony. The above X represents at least one element selected from the group consisting of fluorine, chlorine, bromine, iodine, and sulfur.) Claim 4 A red phosphor according to claim 1 or 3, wherein the content ratio of the Mn reactivated polyfluoride represented by the general formula (1) and the perovskite compound represented by the general formula (2) is in the range of 10:90 to 99.999:0.001 on a mass basis. Claim 5 A method for manufacturing a red phosphor comprising a process of contacting a Mn reactivated polyfluoride represented by the following general formula (1) and a particulate perovskite compound represented by the following general formula (2) in the presence of a solvent, thereby producing a red phosphor attached to the surface of the Mn reactivated polyfluoride such that a portion of the surface of the Mn reactivated polyfluoride is exposed, wherein the average particle size D50 of the perovskite compound is 0.002 μm to 20 μm in the laser diffraction scattering method. L2MF6:Mn 4+ (1) (In the formula, L represents at least one alkali metal element selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium, and M represents at least one tetravalent element selected from the group consisting of silicon, germanium, tin, titanium, zirconium, and hafnium.) ABX3(2) (In the formula, A represents at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, silver, indium, gold, thallium, ammonium, primary ammonium, secondary ammonium, tertiary ammonium, and quaternary ammonium. The primary ammonium, the secondary ammonium, the tertiary ammonium, and the quaternary ammonium have an alkyl group having 1 to 10 carbon atoms, or an alkyl group having a heteroatom with a carbon number in the range of 1 to 10 carbon atoms. B represents magnesium, calcium, barium, zinc, It represents at least one element selected from the group consisting of zirconium, strontium, manganese, iron, cobalt, nickel, copper, titanium, vanadium, chromium, mercury, cadmium, tin, lead, strontium, europium, yttrium, beryllium, indium, aluminum, ruthenium, osmium, and antimony. The above X represents at least one element selected from the group consisting of fluorine, chlorine, bromine, iodine, and sulfur.) Claim 6 A method for manufacturing a red phosphor comprising a process of contacting a particulate Mn reactivated polyfluoride represented by the following general formula (1) and a perovskite compound represented by the following general formula (2) in the presence of a solvent, thereby ensuring that the Mn reactivated polyfluoride adheres to at least a portion of the surface of the perovskite compound, wherein the average particle size D50 of the perovskite compound is 0.002 μm to 20 μm in the laser diffraction scattering method. L2MF6:Mn 4+ (1) (In the formula, L represents at least one alkali metal element selected from the group consisting of lithium, sodium, potassium, rubidium, and cesium, and M represents at least one tetravalent element selected from the group consisting of silicon, germanium, tin, titanium, zirconium, and hafnium.) ABX3(2) (In the formula, A represents at least one element selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, silver, indium, gold, thallium, ammonium, primary ammonium, secondary ammonium, tertiary ammonium, and quaternary ammonium. The primary ammonium, the secondary ammonium, the tertiary ammonium, and the quaternary ammonium have an alkyl group having 1 to 10 carbon atoms, or an alkyl group having a heteroatom with a carbon number in the range of 1 to 10 carbon atoms. B represents magnesium, calcium, barium, zinc, It represents at least one element selected from the group consisting of zirconium, strontium, manganese, iron, cobalt, nickel, copper, titanium, vanadium, chromium, mercury, cadmium, tin, lead, strontium, europium, yttrium, beryllium, indium, aluminum, ruthenium, osmium, and antimony. The above X represents at least one element selected from the group consisting of fluorine, chlorine, bromine, iodine, and sulfur.) Claim 7 A method for manufacturing a red phosphor according to claim 5 or 6, wherein the ratio of the Mn reactivated polyfluoride and the perovskite compound in the red phosphor obtained by contacting the Mn reactivated polyfluoride represented by general formula (1) and the perovskite compound represented by general formula (2) is in the range of 10:90 to 99.999:0.001 by mass. Claim 8 A method for manufacturing a red phosphor according to claim 5 or 6, wherein the solvent is water, an organic solvent, a mixed solvent thereof, or an acidic solvent thereof. Claim 9 A method for manufacturing a red phosphor according to claim 5 or 6, wherein the mixing ratio of the solvent, the Mn reactivated polyfluoride represented by the general formula (1), and the perovskite compound represented by the general formula (2) is in the range of 2:1 to 100:1 by mass. Claim 10 A method for manufacturing a red phosphor according to claim 8, wherein the acidic solvent is an acidic solvent containing hydrogen fluoride, and the concentration of the hydrogen fluoride in the acidic solvent containing hydrogen fluoride is in the range of 1 mass% to 70 mass% with respect to the total mass of the acidic solvent. Claim 11 delete

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