JP5822045B2 - Method for producing double fluoride phosphor - Google Patents

Description

The present invention relates to a formula A ₂ MF ₆ : Mn useful as a red phosphor for a blue LED, wherein M is one or more tetravalent elements selected from Si, Ti, Zr, Hf, Ge and Sn. , A is selected from Li, Na, K, Rb and Cs and is at least one or two or more alkali metals containing Na and / or K.) Mn-activated double fluoride red phosphor The present invention relates to a method for producing (double fluoride phosphor).

For the purpose of improving the color rendering of white LEDs (Light Emitting Diodes) or improving the color reproducibility when white LEDs are used as backlights for liquid crystal displays, they are excited by light equivalent to LEDs from near-ultraviolet to blue. Phosphors that emit light are needed and research is ongoing. Among them, JP 2009-528429 A (Patent Document 1) discloses a compound F ₂ represented by a formula such as A ₂ MF ₆ (A is Na, K, Rb, etc., M is Si, Ge, Ti, etc.). It is described that a compound obtained by adding Mn to a compound (double fluoride phosphor) is useful.

  As for the method for producing the phosphor, Patent Document 1 discloses a method in which a hydrofluoric acid solution in which all constituent elements are dissolved or dispersed is evaporated and concentrated. As another manufacturing method, in US Pat. No. 3,576,756 (Patent Document 2), after mixing a hydrofluoric acid solution in which each constituent element is dissolved, acetone, which is a water-soluble organic solvent, is added to lower the solubility. The method of making it precipitate by making it disclose is disclosed. Furthermore, Japanese Patent No. 4582259 (Patent Document 3) and Japanese Patent Application Laid-Open No. 2012-224536 (Patent Document 4) disclose a solution containing hydrofluoric acid in which the element M and the element A in the above formulas are separate. A method for precipitating phosphors by dissolving them in the solution and mixing them with Mn added to them is disclosed.

The manufacturing process of the double fluoride phosphor represented by the known Mn-added A ₂ MF ₆ (A is Na, K, Rb, etc., M is Si, Ge, Ti, etc.) described above includes the above-mentioned literature. In the step of forming the phosphor, a high concentration of hydrofluoric acid is used in a considerably large amount with respect to the amount of the phosphor obtained. Since hydrofluoric acid is highly corrosive, there are restrictions on the material of the reaction apparatus and the like, which may be a problem when attempting large-scale production. In addition, since it is highly toxic to the human body, there are obstacles to increasing the scale of the chemical process that uses it, even from the viewpoint of the safety of workers handling it.

On the other hand, it has been pointed out that these double fluoride phosphors may be deteriorated in fluorescence characteristics under high temperature and high humidity. In JP 2009-280763 A (Patent Document 5), along with the indication, it is described that the problem of moisture resistance can be alleviated by contrivance in a process of mixing with a silicone resin at the time of LED fabrication. Japanese Patent Application Laid-Open No. 2010-45328 (Patent Document 6) describes that these double fluoride phosphors are covered with a resin or the like before the LED is manufactured to alleviate the problem of moisture resistance.
However, an advantageous method for further improving moisture resistance is desired.
The prior art documents related to the present invention include the following documents in addition to the above documents.

Special table 2009-528429 gazette US Pat. No. 3,576,756 Japanese Patent No. 4582259 JP 2012-224536 A JP 2009-280763 A JP 2010-45328 A

H. Bode, H.M. Jenssen, F.M. Bandte, Angew. Chem. Volume 65 Page 304 (1953) R. Hoppe, W.H. Liebe, W.M. Daehne, Z .; Anorg, Allg. Chem. 307 pages 276 (1961) B. Cox, A.M. G. Sharpe, J. et al. Chem. Soc. , 1798 pages (1954) Published by Maruzen Co., Ltd., Chemical Society of Japan, New Experimental Chemistry Course 8 “Synthesis of Inorganic Compounds III”, published in 1977, page 1166

  An object of this invention is to provide the manufacturing method of the double fluoride fluorescent substance which can be performed by the process which does not use hydrofluoric acid for the main part among the processes which manufacture a double fluoride fluorescent substance.

  As a result of diligent studies to achieve the above object, the present inventor, when producing a red phosphor that is a Mn-activated bifluoride, is not essentially wet, but is mixed with the raw material powder described later, It has been found that it is effective to adopt a dry method for producing the desired double fluoride phosphor by causing the diffusion movement of the substance by heating, and the present invention has been made by examining the conditions and the like. .

  In addition, the red phosphor, which is a Mn-activated bifluoride produced by this dry method, has better moisture resistance than the double fluoride red phosphor produced by a wet method, and has already been produced. It has been found that the moisture resistance of the phosphor can be improved by adding an additive that promotes the diffusion of the substance to the double fluoride red phosphor and heat-treating it, and the present invention has been completed.

That is, this invention provides the manufacturing method of the following double fluoride fluorescent substance.
[1] The following formula (1)
A ₂ MF ₆ : Mn (1)
Wherein M is one or more tetravalent elements selected from Si, Ti, Zr, Hf, Ge and Sn, A is selected from Li, Na, K, Rb and Cs, and at least Na and And / or one or more alkali metals containing K.)
Is a method for producing a red phosphor which is a Mn-activated double fluoride represented by the following formula (2)
A ₂ MF ₆ (2)
(Wherein, M is Si, Ti, Zr, Hf, Ru one or more tetravalent element der selected from Ge and Sn. A is selected Li, Na, K, from Rb and Cs, and One or more alkali metals containing at least Na and / or K.)
A solid of a double fluoride represented by the following formula (3)
A ₂ MnF ₆ (3)
(In the formula, A is one or more alkali metals selected from Li, Na, K, Rb and Cs and containing at least Na and / or K.)
A method for producing a Mn-activated bifluoride phosphor, comprising mixing a solid of a manganese compound represented by formula ( I), sealing the mixture in a reaction vessel, and heating the mixture at 100 ° C to 500 ° C.
[2] The method for producing a Mn-activated bifluoride phosphor according to [1], wherein the reaction raw material is heated and reacted in a ceramic container or a reaction container in which a part in contact with the reactant is formed of a fluororesin. .
[3] The Mn-activated double fluoride fluorescent material according to [1], wherein the reaction raw material is heated and reacted at 100 ° C. or higher and 270 ° C. or lower in a reaction vessel in which a part in contact with the reactant is formed of a fluororesin. Body manufacturing method.
[4] The reaction mixture obtained by heating is washed with an inorganic acid solution or a fluoride salt solution to remove unnecessary components, followed by solid-liquid separation and drying of the solid content [1] to [3] The method for producing a Mn-activated double fluoride phosphor according to any one of [3].
[5] Further, an alkali metal nitrate, sulfate, hydrogen sulfate or fluoride is added to the above mixture, and the following formula (4):
A ¹ F · nHF (4)
(In the formula, A ¹ is one or more alkali metals or ammonium selected from Na, K, Rb and NH ₄ , and n is a number of 0.7 or more and 4 or less.)
The method for producing a Mn-activated double fluoride phosphor according to any one of [1] to [4], wherein the mixture is heated together with a hydrogen fluoride salt represented by the formula:
Furthermore, the present invention is a manufacturing method and a processing method of the double fluoride phosphors below pertains.
[6] Furthermore, the following formula (4) is added to the above mixture.
A ¹ F · nHF (4)
(In the formula, A ¹ is one or more alkali metals or ammonium selected from Na, K, Rb and NH ₄ , and n is a number of 0.7 or more and 4 or less.)
The method for producing a Mn-activated bifluoride phosphor according to any one of [1] to [4], wherein the hydrogen fluoride salt represented by formula (1) is mixed with a solid and heated.
[7] The following formula (1)
A ₂ MF ₆ : Mn (1)
Wherein M is one or more tetravalent elements selected from Si, Ti, Zr, Hf, Ge and Sn, A is selected from Li, Na, K, Rb and Cs, and at least Na and And / or one or more alkali metals containing K.)
In the red phosphor that is a Mn-activated double fluoride represented by the following formula (4)
A ¹ F · nHF (4)
(In the formula, A ¹ is one or more alkali metals or ammonium selected from Na, K, Rb and NH ₄ , and n is a number of 0.7 or more and 4 or less.)
A method for treating a Mn-activated double fluoride phosphor, comprising mixing and heating a hydrogen fluoride salt represented by the formula:
[8] The method for treating a Mn-activated bifluoride phosphor according to [7], wherein the reaction raw material is heated and reacted in a ceramic container or a reaction container in which a portion in contact with the reactant is formed of a fluororesin. .
[9] The reaction mixture obtained by heating is washed with an inorganic acid solution or a fluoride salt solution to remove unnecessary components, followed by solid-liquid separation and drying of the solid content [7] or [7] 8] The processing method of Mn activation double fluoride fluorescent substance of description.

  According to the production method of the present invention, a Mn-activated bifluoride phosphor having good light emission characteristics can be obtained without using hydrofluoric acid in the main process. Moreover, according to the processing method of the present invention, a Mn-activated double fluoride phosphor excellent in moisture resistance can be obtained.

It is a schematic sectional drawing which shows an example of the reaction apparatus used for implementation of this invention. 2 is a powder X-ray diffraction pattern of the mixed powder obtained in Example 1. FIG. It is a powder X-ray-diffraction pattern of the heating unwashed powder of Example 1. 3 is a powder X-ray diffraction pattern of the washed dry powder of Example 1. FIG. It is the spectrum of the excitation light and fluorescence of the mixed powder of the same Example 1, unheated powder, and washed dry powder. It is a schematic sectional drawing which shows the other example of the reaction apparatus used for implementation of this invention. It is a schematic sectional drawing of the light-emitting device for a test used in the evaluation experiment 3.

Below, embodiment of the manufacturing method of the double fluoride fluorescent substance concerning this invention is described.
The phosphor production method according to the present invention comprises the following formula (1):
A ₂ MF ₆ : Mn (1)
Wherein M is one or more tetravalent elements selected from Si, Ti, Zr, Hf, Ge and Sn, A is selected from Li, Na, K, Rb and Cs, and at least Na and And / or one or more alkali metals containing K.)
A red phosphor that is a Mn-activated bifluoride represented by the following formula (2):
A ₂ MF ₆ (2)
(In the formula, M is one or two or more tetravalent elements selected from Si, Ti, Zr, Hf, Ge and Sn, and substantially does not contain Mn, A is Li, Na, K, Rb. And one or more alkali metals selected from Cs and containing at least Na and / or K.)
A solid of a double fluoride represented by the following formula (3)
A ₂ MnF ₆ (3)
(In the formula, A is one or more alkali metals selected from Li, Na, K, Rb and Cs and containing at least Na and / or K.)
Is mixed with a solid of a manganese compound represented by the formula, and heated at 100 ° C. or more and 500 ° C. or less.

One of the double fluorides used as a raw material in the present invention is a double fluoride represented by the above formula (2). These can use a commercial item. Further, the following formula (5) corresponding to each element M
H ₂ MF ₆ (5)
(In the formula, M is one or more tetravalent elements selected from Si, Ti, Zr, Hf, Ge, and Sn, and substantially does not contain Mn.)
And a solution of a water-soluble salt of a corresponding alkali metal A such as fluoride, chloride, nitrate, sulfate, carbonate, bicarbonate, hydroxide, or a solid, or a solid. It is also possible to use one.

  The manganese raw material used in the present invention is a hexafluoromanganate represented by the above formula (3). This is a known method, namely (A) H. Bode, H.M. Jenssen, F.M. Bandte, Angew. Chem. 65, 304 (1953) (Non-patent Document 1), a method of reducing potassium permanganate with hydrogen peroxide in the presence of potassium fluoride, (B) Hoppe, W.H. Liebe, W.M. Daehne, Z .; Anorg, Allg. Chem. 307, 276 (1961) (Non-patent Document 2), a method of heating a mixture of manganese and anhydrous alkali metal chloride in a fluorine gas stream, (C) B. Cox, A.M. G. Sharpe, J. et al. Chem. Soc. , 1798 pages (1954) (Non-Patent Document 3) and published by Maruzen Co., Ltd., edited by The Chemical Society of Japan, New Experimental Chemistry Course 8 “Synthesis of Inorganic Compounds III”, published in 1977, Non-Patent Document 4 A method prepared by any of the methods described above for synthesis by electrolytic reaction of a liquid containing manganese fluoride can be used.

The mixing ratio of the raw material of the tetravalent metal M and the manganese raw material is 0.001 to 0.3 mol, preferably 0.002 to 0.2 mol, and more preferably 0 to 0.001 to 0.3 mol, with respect to 1 mol. 0.005 to 0.15 mole. If the amount is less than 0.001 mol, the amount of the activator Mn in the product phosphor is too small, and the light emission characteristics are not sufficient. Even if the amount exceeds 0.3 mol, the light emission characteristics are deteriorated.
To mix these ingredients, put both ingredients in a polyethylene bag, shake or rotate, put it in a container with a lid made of polyethylene, put it on a rocking mixer, tumbler mixer, etc. Arbitrary methods can be used.

Furthermore, the following formula (4) is added to the above mixture.
A ¹ F · nHF (4)
(In the formula, A ¹ is one or more alkali metals or ammonium selected from Li, Na, K, Rb and NH ₄ , and n is 0.7 or more and 4 or less, preferably 0.9 or more. The number is 2.5 or less.)
The reaction can be promoted by mixing and heating the hydrogen fluoride salt represented by As these hydrogen fluoride salts, commercially available products such as ammonium hydrogen fluoride (NH ₄ HF ₂ ), sodium hydrogen fluoride (NaHF ₂ ), potassium hydrogen fluoride (KHF ₂ ), and KF · 2HF may be used. it can.

The amount of hydrogen fluoride added is preferably 0 to 2.5 moles of A ¹ such as an alkali metal with respect to 1 mole of the main component metal M. More preferably, it is 0.1-2.0 mol. Even if the amount of the hydrogen fluoride salt is increased beyond 2.5 mol, there is no advantage in the production of the phosphor, and there is a possibility that the product becomes a lump and is difficult to be loosened.
Although the method of mixing the hydrogen fluoride salt is not limited, it may generate heat during mixing. Therefore, it is desirable to avoid mixing with strong force and to mix in a short time.

The hydrogen fluoride salt may be mixed at the same time when the double fluoride A ₂ MF ₆ and the manganese raw material A ₂ MnF ₆ are mixed. However, if the above points are taken into consideration, A ₂ MF is mixed in advance. It is preferable to mix a hydrogen fluoride salt with a mixture of ₆ and A ₂ MnF ₆ later.

  As a reaction accelerator, it is also effective to add alkali metal nitrate, sulfate, hydrogen sulfate, and fluoride together with hydrogen fluoride in addition to hydrogen fluoride. The addition amount in this case is preferably in a range not exceeding the hydrogen fluoride salt in terms of moles.

The mixed raw material is heated as described above. The heating temperature is 100 to 500 ° C, preferably 150 to 450 ° C, more preferably 170 to 400 ° C. Atmosphere during heating in air, in nitrogen, but good like argon, a reducing atmosphere containing hydrogen is preferable because there is a possibility of decrease in emission characteristics caused by manganese is reduced.
A method can be applied in which the mixed raw materials are put into a sealed container and the whole container is put into a dryer, oven, or the like. When using an airtight container, it is preferable to use the one in which the part in contact with the reactant is made of a fluororesin. Not only this but the container made from a fluororesin can be used suitably when heating temperature is 270 degrees C or less. When the heating temperature is higher than this, it is preferable to use a ceramic container. The ceramic in this case is preferably alumina, magnesia or magnesium aluminum spinel.

  More specifically, as a reaction vessel, a double vessel 1 in which an inner layer 3 made of polytetrafluoroethylene is formed on the inner wall of a stainless steel vessel main body 2 shown in FIG. 1 is used. It is preferable to make it. In addition, as a material of the cover body 4, it is preferable to use stainless steel. It is also effective to use the reaction apparatus shown in FIG. The reactor shown in FIG. 6 has a ceramic inner layer 6 formed on the inner wall of a SUS (stainless steel) container 5, covered with a fluorine resin covering the upper end opening, and a gas outlet hole 7 formed in the center. A stainless steel cooling pipe 9a is installed on the outer peripheral upper end of the container 5 and on the outer peripheral part of the gas outflow pipe 7a projecting from the gas outflow hole 7, and the powder mixture 10 placed in the inside is installed. Is a heater 9b that is heated at the bottom of the outer periphery of the container 5.

  The reaction product obtained as described above may contain unreacted hexafluoromanganate in addition to the desired double fluoride phosphor, and when hydrogen fluoride is added, It also remains. These can be removed by washing.

For washing, an inorganic acid solution such as hydrochloric acid, nitric acid, or hydrofluoric acid, or a fluoride salt solution such as ammonium fluoride or potassium fluoride can be used. A hydrofluoric acid or ammonium fluoride solution is more preferable. In order to suppress the elution of the phosphor component, a water-soluble organic solvent such as ethanol or acetone can be added. It is also effective to dissolve the raw material A ₂ MF ₆ in a cleaning solution.

  In addition, as described above, the method for producing a double fluoride phosphor according to the present invention is to obtain a double fluoride phosphor by heating the mixture of the raw material powders. Is not used in the manufacture of double fluoride phosphors. In this case, hydrofluoric acid is used as a cleaning component for cleaning the obtained reaction product containing the double fluoride phosphor to remove unnecessary components (raw material powder and reaction by-products other than the target double fluoride phosphor). It may be used. Thus, even when hydrofluoric acid is used, the amount used is small compared to the case where it is used when the double fluoride phosphor is produced by a conventional wet method.

After washing as described above, the solid content is dried by a conventional method to obtain Mn activated double fluoride.
The obtained double fluoride is excellent in light emission characteristics equivalent to the Mn-activated double fluoride obtained by a conventional wet method.

As another embodiment of the present invention, a method for treating a previously prepared Mn-activated double fluoride red phosphor will be described. The red phosphor used is the above formula (1)
A ₂ MF ₆ : Mn (1)
Wherein M is one or more tetravalent elements selected from Si, Ti, Zr, Hf, Ge and Sn, A is selected from Li, Na, K, Rb and Cs, and at least Na and And / or one or more alkali metals containing K.)
It is a red fluorescent substance which is Mn activation double fluoride represented by these. Any of the conventionally known wet methods and those produced by any of the dry methods described in the present invention can be used.

In addition to the above equation (4)
A ¹ F · nHF (4)
(In the formula, A ¹ is one or more alkali metals or ammonium selected from Li, Na, K, Rb and NH ₄ , and n is a number of 0.7 or more and 4 or less.)
A hydrogen fluoride salt represented by the following formula is mixed with a solid and heated. As these hydrogen fluoride salts, commercially available products such as ammonium hydrogen fluoride (NH ₄ HF ₂ ), sodium hydrogen fluoride (NaHF ₂ ), potassium hydrogen fluoride (KHF ₂ ), and KF · 2HF may be used. it can.

The addition amount of these hydrogen fluoride salts is preferably 0.01 to 2.0 mol of A ¹ such as an alkali metal with respect to 1 mol of the main component metal M. More preferably, it is 0.03-1.5 mol. There is no advantage in increasing the amount of hydrogen fluoride beyond 2.0 mol.
Although the method of mixing the hydrogen fluoride salt is not limited, it may generate heat during mixing. Therefore, it is desirable to avoid mixing with strong force and to mix in a short time.

  Operations such as addition of a reaction accelerator, heating, washing / recovery after heating, and the like can be performed in the same manner as the above-described phosphor manufacturing method, and may be performed according to the above-described method.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

[Example 1]
26.43 g of potassium silicofluoride (manufactured by Morita Chemical Co., Ltd., K ₂ SiF ₆ ) powder and 2.46 g of potassium hexafluoromanganate (produced by the method described in Reference Example 1 described later, K ₂ MnF ₆ ) powder Placed in the same polyethylene zippered bag. The mixture was shaken by hand or slowly rotated for 5 minutes. The mixing ratio corresponds to 0.083 mol of Mn relative to 1 mol of Si.
To this mixed powder, powder 14.06 g of potassium hydrogen fluoride (acidic potassium fluoride manufactured by Stella Chemifa, KHF ₂ ) was further added and mixed in the same manner as described above. The ratio corresponds to 1.5 mol of KHF ₂ with respect to 1 mol of Si. Of the powder mixture, 2.0 g (mixed powder) was reserved for later evaluation.
The powder mixture was placed in a double container 1 shown in FIG. 1 and sealed. Here, in FIG. 1, a double container 1 is formed by forming an inner layer 3 made of polytetrafluoroethylene on the inner wall of a stainless steel (SUS) container body 2, and the double container 1 contains powder. The mixture 10 was put in, sealed with a lid 4 made of SUS, and heated in an oven. The temperature was 250 ° C. and the time was maintained for 12 hours, followed by natural cooling.

Although the cooled reaction product was partly powdery, most of it was agglomerated, so it was roughly crushed and mixed, and a part of 2.0 g was taken out for evaluation. The taken out portion was further ground in a mortar (heated unwashed powder).
As a cleaning solution, a solution in which 4.1 g of potassium silicofluoride was dissolved in 100 cm ³ of 50% by mass hydrofluoric acid (SA-X manufactured by Stella Chemifa, 50% by mass HF) was prepared. Of these, the remainder of the reaction product was added to 75 cm ³ and allowed to stand for 10 minutes with stirring. The massive part was loosened and became powdery.
The powdery precipitate was filtered off with a Buchner funnel and washed with the rest of the previously prepared cleaning solution. Further, it was washed with acetone and collected, and then dried in vacuum. 28.2 g of powder product was obtained (washed dry powder). The particle size distribution of the powder product was measured with an airflow dispersion type laser diffraction particle size distribution analyzer (HELOS & RODOS, manufactured by Sympatec). As a result, particles having a particle size of 8.6 μm or less were 10% of the total volume (D10 = 8.6 μm), particles having a particle size of 21.3 μm or less were 50% of the total volume (D50 = 21.3 μm), and particle size 33 Particles of less than 0.7 μm accounted for 90% of the total volume (D90 = 33.7 μm).

The powder X-ray diffraction pattern of the mixed powder is shown in FIG. The assignment of peaks identified with reference to the database is indicated by marks. In addition to K ₂ SiF ₆ , K ₂ MnF ₆ and KHF ₂ are observed.
Next, the powder X-ray diffraction pattern of the unwashed powder is shown in FIG. While the ratio of the KHF ₂ peak is large, the peak of K ₂ MnF ₆ is significantly weaker than that of the mixed powder in FIG. This can be clearly seen by looking at a peak around 2θ = 34 ° that does not overlap with the peaks of other compounds. It can be estimated that Mn is taken into K ₂ SiF ₆ and K ₂ MnF ₆ is reduced.

Furthermore, the powder X-ray diffraction pattern of the washed dry powder is shown in FIG. It matches the pattern of K ₂ SiF _{6 in} PDF01-075-0694 of the ICDD (International Center for Diffraction Data) powder X-ray diffraction database, and no impurities are observed. It can be seen that KHF ₂ was removed by washing.
The emission spectra of the powder samples at these stages were measured at an excitation wavelength of 450 nm using a quantum efficiency measurement device QE1100 (manufactured by Otsuka Electronics Co., Ltd.). The excitation light and fluorescence spectra are shown in FIG. The mixed powder does not emit light, but the heated unwashed powder exhibits red light emission. The luminescence is strengthened by washing and drying.
Table 1 shows the absorptance and internal quantum efficiency at 450 nm excitation measured with the same apparatus.

  Combining X-ray diffraction and light emission characteristics, it can be said that the phosphor is generated in the heating step before cleaning.

[Reference Example 1]
[Preparation of K ₂ MnF ₆ ]
In accordance with the method described in Non-Patent Document 4, it was prepared by the following method.
A fluororesin-based ion exchange membrane partition (diaphragm) was provided at the center of the reaction vessel made of vinyl chloride resin, and an anode and a cathode each made of a platinum plate were installed in each of the two chambers sandwiching the ion exchange membrane. A hydrofluoric acid aqueous solution in which manganese (II) was dissolved was placed on the anode side of the reaction tank, and a hydrofluoric acid aqueous solution was placed on the cathode side. Both electrodes were connected to a power source, and electrolysis was performed at a voltage of 3 V and a current of 0.75 A. After the electrolysis, an excessive solution of potassium fluoride saturated with an aqueous hydrofluoric acid solution was added to the reaction solution on the anode side. The produced yellow solid product was separated by filtration and recovered to obtain K ₂ MnF ₆ .

[Example 2]
31.0 g of potassium hydrogen fluoride was replaced with 11.72 g in the same manner as in Example 1 except that 4.08 g of potassium hydrogen sulfate (special grade of Wako Pure Chemicals, KHSO ₄ ) was added. A powder product of K ₂ SiF ₆ : Mn was obtained. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 8.2 μm, D50 = 22.1 μm, and D90 = 35.4 μm.

[Example 3]
30.4 g of K _{2 in the same} manner as in Example 1 except that 14.06 g of potassium hydrogen fluoride is replaced with 11.72 g and 3.03 g of potassium nitrate (special grade of Wako Pure Chemicals, KNO ₃ ) is added. A powder product of SiF ₆ : Mn was obtained. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 6.9 μm, D50 = 20.0 μm, and D90 = 31.0 μm.

[Example 4]
26.43 g of K ₂ SiF ₆ powder and 1.23 g of the same K ₂ MnF ₆ powder as in Example 1 were put in the same bag with polyethylene chuck. The mixture was shaken by hand or slowly rotated for 5 minutes. The mixing ratio corresponds to 0.042 mol of Mn with respect to 1 mol of Si.
This mixture was put into a magnesia crucible, and further put into an outer container of SUS, and then put into a temperature-controlled tube furnace. The furnace was placed in a draft chamber, and a SUS container was provided with a port through which gas was generated, and a hole was also made in the lid of the magnesia crucible. In addition, the outlet portion of the SUS container that was not in the tubular furnace was wound with a SUS tube so that water could flow to cool it. This reactor is shown in FIG. Using this apparatus, it heated at 300 degreeC for 8 hours, and cooled naturally. The reaction was removed and ground to collect. A powder product of 30.2 g of K ₂ SiF ₆ : Mn was obtained. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 7.3 μm, D50 = 16.7 μm, and D90 = 37.5 μm.

[Example 5]
K ₂ SiF ₆ and K ₂ MnF ₆ were mixed in the same amount as in Example 4. To this, 6.85 g of ammonium hydrogen fluoride (acidic ammonium fluoride manufactured by Stella Chemifa, NH ₄ HF ₂ ) was further mixed. This was charged in the same apparatus of FIG. 6 as in Example 4 and heated at 350 ° C. for 6 hours. The removed after cooling 35 wt% hydrochloric acid (manufactured by Wako Pure Chemical Industries, Ltd. electronic industry, HCl) was added and stirred in a mixture of 10 cm ³ of ethanol 70cm ^3. The solution was filtered with a Buchner funnel, washed with acetone, collected, and dried in vacuo. A powder product of 32.7 g of K ₂ SiF ₆ : Mn was obtained. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 9.1 μm, D50 = 18.0 μm, and D90 = 32.5 μm.

[Example 6]
K ₂ SiF ₆ and K ₂ MnF ₆ were mixed in the same amount as in Example 4. This was further mixed with 7.03 g of KHF ₂ . Heated as in Example 5. The solution was taken out after cooling, and added to 80 cm ³ of 40% by mass ammonium fluoride solution (for semiconductor, manufactured by Morita Chemical Co., Ltd., NH ₄ F) and stirred. The solution was filtered with a Buchner funnel, washed with acetone, collected, and dried in vacuo. A powder product of 32.3 g of K ₂ SiF ₆ : Mn was obtained. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 8.9 μm, D50 = 18.6 μm, and D90 = 28.1 μm.

[Example 7]
Potassium hexafluorotitanate (Morita Chemical Co., Ltd., K ₂ TiF ₆ ) powder was used in an amount of 28.8 g, the same K ₂ MnF ₆ as in Example 1 was used in an amount of 1.48 g, and KHF ₂ was used in 9.37 g. Other than the above, mixing was performed in the same manner as in Example 1, and heating was performed under the same conditions. The removed after cooling and stirred for 10 minutes added to a mixture of 50 wt% HF10cm ³ and acetone 70cm ^3. The powdered precipitate was filtered off with a Buchner funnel, washed with acetone, collected, and dried in vacuo. A powder product of 32.7 g of K ₂ TiF ₆ : Mn was obtained. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 9.9 μm, D50 = 38.2 μm, and D90 = 72.6 μm.

[Example 8]
Sodium hexafluoromanganate (produced by the method of Reference Example 2 described later, Na ₂ MnF ₆ ) 2.14 g using sodium silicofluoride (Morita Chemical Co., Ltd., Na ₂ SiF ₆ ) powder , Except that 9.36 g of sodium hydrogen fluoride (Stella Chemifa acid sodium fluoride, NaHF ₂ ) was used instead of potassium hydrogen fluoride, mixing was performed in the same manner as in Example 1, and heating was performed under the same conditions. did. After cooling, the reaction product was recovered and crushed roughly.
Separately, a solution prepared by dissolving 2.8 g of potassium silicofluoride in 50% by mass of HF of 100 cm ³ was prepared. Of these, the above reaction product was added to 75 cm ³ and allowed to stand for 10 minutes with stirring. The massive part was loosened and became powdery. The powdery precipitate was filtered off with a Buchner funnel and washed with the rest of the previously prepared cleaning solution. Further, it was washed with acetone and collected, and then dried in vacuum. A powder product of 25.6 g Na ₂ SiF ₆ : Mn was obtained. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 6.2 μm, D50 = 29.7 μm, and D90 = 56.1 μm.

[Reference Example 2]
[Preparation of Na ₂ MnF ₆ ]
Using the same electrolytic reaction vessel as that for the preparation of K ₂ MnF _{6 in} Reference Example 1, the reaction was performed in the same manner except that sodium fluoride was added instead of potassium fluoride, and the resulting yellow solid product was filtered off. recovered to obtain a Na ₂ MnF _6.

[Example 9]
In place of potassium hydrogen fluoride (KHF ₂ ), 11.77 g of a hydrogen fluoride salt (Morita Chemical Industry Co., Ltd.) represented by KF · 2HF is added, and the amount of potassium hexafluoromanganate powder added is 0 29.9 g of a K ₂ SiF ₆ : Mn powder product was obtained in the same manner as in Example 1 except that the amount was changed to .99 g. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 18.1 μm, D50 = 27.8 μm, and D90 = 40.9 μm.

[Comparative Example 1]
40 wt% silicate hydrofluoric acid (H ₂ SiF ₆₎ solution (manufactured by Morita Chemical Industries (Ltd.)) 15.6cm ^3, was first mixed with 50 wt% HF100cm ^3. To this, 1.19 g of the same K ₂ MnF ₆ powder as in Example 1 was added and dissolved by stirring to prepare an aqueous solution (first solution) containing Si, F and Mn. Further, 13.95 g of potassium fluoride was dissolved in 40 cm ³ of 50% by mass HF, allowed to cool to room temperature, and an aqueous solution containing potassium fluoride (second solution) was prepared. Next, the second solution was added little by little to the stirred first solution over about 3 minutes, and stirred for about 10 minutes to produce a pale orange solid. The solid product was filtered off, washed with acetone and dried in vacuo to give 15.64 g of K ₂ SiF ₆ : Mn powder product. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 15.1 μm, D50 = 36.9 μm, and D90 = 60.3 μm.

[Comparative Example 2]
40 mass% titanium hydrofluoric acid (H ₂ SiF ₆ ) aqueous solution (Morita Chemical Industry Co., Ltd.) 15.6 cm ³ was first mixed with 50 mass% HF 100 cm ³ HF. To this, 0.74 g of the same K ₂ MnF ₆ powder as in Example 1 was added and dissolved by stirring to prepare an aqueous solution (first solution) containing Ti, F and Mn. Further, 23.43 g of KHF ₂ was dissolved in 22 cm ³ of 50% by mass HF and 34 cm ³ of pure water to prepare an aqueous solution containing potassium fluoride (second solution). Next, the second solution was added little by little to the stirred first solution over about 2 minutes, and the mixture was stirred for about 10 minutes to produce a pale orange solid. The solid product was filtered off, washed with acetone and dried in vacuo to give 13.73 g of a K ₂ TiF ₆ : Mn powder product. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 13.6 μm, D50 = 46.5 μm, and D90 = 103.2 μm.

[Example 10]
First, 50 mass% hydrofluoric acid (HF) (SA-X, manufactured by Stella Chemifa Co., Ltd.) was added to 234 cm ³ of 40 mass% hydrofluoric acid (H ₂ SiF ₆ ) aqueous solution (Morita Chemical Industry Co., Ltd.). ) Mixed with 2,660 cm ³ . To this, 13.32 g of K ₂ MnF ₆ powder prepared in advance by the aforementioned method was added and stirred to dissolve (first solution).
Separately, potassium hydrogen fluoride (KHF ₂₎ 210.5g of 50 wt% hydrofluoric acid aqueous solution 680 cm ^3, were dissolved and mixed with purified water 1,270cm ³ (second solution).
While the first solution was stirred, the second solution was added little by little, and a pale orange precipitate was formed. This precipitate was filtered off with a Buchner funnel and sufficiently drained, then washed with acetone, drained and recovered, and further vacuum dried. 184.9 g of a powder product was obtained.
Take 26.43 g of this powder, mix it with 1.96 g of hydrogen fluoride salt represented by KF · 2HF, put it in the same container as in Example 1, and heat it under the same conditions. As a result, 26.87 g of a phosphor was obtained. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 13.1 μm, D50 = 25.8 μm, and D90 = 39.7 μm.

[Comparative Example 3]
In Example 10, only the precipitation, filtration, washing, and vacuum drying were performed, and the remainder not used for the heat treatment was taken. The results of the particle size distribution measured in the same manner as in Example 1 were D10 = 8.4 μm, D50 = 19.2 μm, and D90 = 29.3 μm.

[Evaluation Experiment 1]
The emission characteristics of the phosphors obtained in the examples and comparative examples were measured with the quantum efficiency measuring device QE1100 (manufactured by Otsuka Electronics Co., Ltd.) described in Example 1. Table 2 shows the absorptance and quantum efficiency at an excitation wavelength of 450 nm.

[Evaluation Experiment 2]
Durability tests were performed on the phosphors obtained in the examples and comparative examples.
Put the phosphor in powder in a small dish without a lid, and leave it for 30 minutes and 7 days in a constant temperature and humidity chamber (manufactured by Espec Corp.) maintained at a temperature of 65 ° C. and a relative humidity of 90% as a durability test. Then, the internal quantum efficiency was measured in the same manner as in Experimental Example 2. The results are shown in Table 3.

[Evaluation Experiment 3]
The test light emitting device shown in FIG. 7 was produced. In FIG. 7, 11 is an opaque base housing having a recess 12, and a chip 13 is arranged on the inner bottom surface of the recess 12. The chip 13 is an InGaN blue light emitting diode having a light emission peak wavelength of 450 nm and a peak half-value width of 20 nm. In the figure, reference numerals 14 and 15 denote electrical connection portions embedded in the base housing 11. One electrical connection portion 14 is in electrical contact with the lower electrode of the chip 13, and the other electrical connection portion 15 is connected to the chip 13. The upper electrode is connected to the upper electrode via a bonding wire 16. The wall surface 17 of the recess 12 of the base housing 11 reflects visible light, and the recess 12 is filled with a cured product 19 of a liquid thermosetting resin previously kneaded with the phosphor 18. The chip 13 is sealed.
In the experiment, 10 parts by mass of a silicone resin (LPS-5547 manufactured by Shin-Etsu Chemical Co., Ltd.) as a thermosetting resin and 4 parts by mass of a double fluoride red phosphor obtained in Examples and Comparative Examples were mixed as a phosphor. Used. After this was poured into the recess of the base housing, it was cured by heating at 150 ° C. for 4 hours.
The emission color of the prepared LED was first measured with an Otsuka Electronics total luminous flux measuring device. The color is represented by CIE chromaticity coordinates (x, y). Next, in a thermostat at 85 ° C., a current of 0.2 A was continuously supplied for 100 hours, and then the emission color was measured in the same manner. The product dxdy of the change dx of x and the change dy of y after 100 hours was observed. The same test was conducted at 60 ° C. and a relative humidity of 90%. The results are shown in Table 4.

Table 5 shows the results of comparing the amount of 50% by mass hydrofluoric acid used when converted to 100 g of a phosphor (K ₂ SiF ₆ : Mn, etc.) between the known method and the present invention. The present invention accounts for hydrofluoric acid used for cleaning. Each example does not include the amount used for producing a manganese intermediate as a raw material for producing a phosphor. Comparative Example 1 is also Example 1 of Patent Document 4, Reference Example 3 is Example 5 of Patent Document 2, and Reference Example 4 is Examples 1 to 9 of Patent Document 3.

※実施例６はフッ化水素酸を使用しないが、参考として４０質量％フッ化アンモニウム溶液の使用量を記載した。

* Although Example 6 does not use hydrofluoric acid, the amount of 40% by mass ammonium fluoride solution used is described as a reference.

  Although the present invention has been described with the embodiment, the present invention is not limited to the embodiment, and other embodiments, additions, changes, deletions, and the like can be conceived by those skilled in the art. As long as the effects of the present invention are exhibited in any aspect, they are included in the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Double container 2 Container main body 3 Inner layer 4 Lid body 5 Container 6 Inner layer 7 Gas outflow hole 7a Gas outflow pipe 8 Lid 9a Cooling pipe 9b Heater 10 Powder mixture 11 Base housing 12 Recess 13 Chip 14 Electrical connection part 15 Electrical connection Part 16 Bonding wire 17 Wall surface 18 Phosphor 19 Thermosetting resin

Claims (5)

Following formula (1)
A ₂ MF ₆ : Mn (1)
Wherein M is one or more tetravalent elements selected from Si, Ti, Zr, Hf, Ge and Sn, A is selected from Li, Na, K, Rb and Cs, and at least Na and And / or one or more alkali metals containing K.)
Is a method for producing a red phosphor which is a Mn-activated double fluoride represented by the following formula (2)
A ₂ MF ₆ (2)
(Wherein, M is Si, Ti, Zr, Hf, Ru one or more tetravalent element der selected from Ge and Sn. A is selected Li, Na, K, from Rb and Cs, and One or more alkali metals containing at least Na and / or K.)
A solid of a double fluoride represented by the following formula (3)
A ₂ MnF ₆ (3)
(In the formula, A is one or more alkali metals selected from Li, Na, K, Rb and Cs and containing at least Na and / or K.)
A method for producing a Mn-activated bifluoride phosphor, comprising mixing a solid of a manganese compound represented by formula ( I), sealing the mixture in a reaction vessel, and heating the mixture at 100 ° C to 500 ° C.   2. The method for producing a Mn-activated bifluoride phosphor according to claim 1, wherein the reaction raw material is heated and reacted in a ceramic container or a reaction container in which a part in contact with the reactant is formed of a fluororesin.   2. The production of a Mn-activated double fluoride phosphor according to claim 1, wherein the reaction raw material is heated and reacted at 100 ° C. or higher and 270 ° C. or lower in a reaction vessel in which a part in contact with the reactant is formed of a fluororesin. Method.   The reaction mixture obtained by heating is washed with an inorganic acid solution or a fluoride salt solution to remove unnecessary components, followed by solid-liquid separation and drying of the solid content. A method for producing the Mn-activated double fluoride phosphor according to claim 1. Furthermore, an alkali metal nitrate, sulfate, hydrogen sulfate or fluoride is added to the above mixture, and the following formula (4):
A ¹ F · nHF (4)
(In the formula, A ¹ is one or more alkali metals or ammonium selected from Na, K, Rb and NH ₄ , and n is a number of 0.7 or more and 4 or less.)
The method for producing a Mn-activated bifluoride phosphor according to any one of claims 1 to 4, wherein the mixture is heated in a solid together with a hydrogen fluoride salt represented by formula (1).

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