WO2014136840A1 - Phosphate phosphor and method for manufacturing phosphate phosphor - Google Patents

Phosphate phosphor and method for manufacturing phosphate phosphor Download PDF

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WO2014136840A1
WO2014136840A1 PCT/JP2014/055633 JP2014055633W WO2014136840A1 WO 2014136840 A1 WO2014136840 A1 WO 2014136840A1 JP 2014055633 W JP2014055633 W JP 2014055633W WO 2014136840 A1 WO2014136840 A1 WO 2014136840A1
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phosphor
mol
namgpo
concentration
phosphate phosphor
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PCT/JP2014/055633
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French (fr)
Japanese (ja)
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戸田 健司
峰夫 佐藤
和義 上松
雅 石垣
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国立大学法人 新潟大学
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Priority to JP2015504359A priority Critical patent/JP6379332B2/en
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    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09KMATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/08Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
    • C09K11/77Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals
    • C09K11/7728Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing rare earth metals containing europium
    • C09K11/7737Phosphates
    • C09K11/7738Phosphates with alkaline earth metals

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  • the present invention relates to a novel phosphate phosphor having a crystal structure different from existing NaMgPO 4 : Eu 2+ and NaMgPO 4 : Ce 3+ and exhibiting different light emission characteristics.
  • a known red light-emitting phosphor made of nitride includes CaAlSiN 3 : Eu 2+ (see Non-Patent Document 1).
  • a phosphor using nitride as a raw material has problems such as extremely high firing temperature (for example, about 1900 ° C.) and the need for a pressure furnace.
  • CaS: Eu ⁇ 2+> is mentioned as a well-known red light emission fluorescent substance which consists of sulfides (refer nonpatent literature 2).
  • phosphors using sulfides as raw materials have been pointed out problems such as low water resistance.
  • NaMgPO 4 : Eu 2+ which is one of oxides, has been reported to emit blue light (see Non-Patent Document 3).
  • the phosphor disclosed in Non-Patent Document 3 is produced under firing conditions of 950 ° C. and 5 hours, is excited in the range of 240 to 410 nm, and exhibits blue emission with a blue emission peak wavelength of 437 nm.
  • Mg 3 Na 3 (PO 4 ) 3 has been proposed as a phosphor of the same kind as NaMgPO 4 and has already been reported to have a glasselite type structure (see FIG. 18 of this application and Non-Patent Document 4). ).
  • NaMgPO 4 : Ce 3+ is also disclosed in Non-Patent Document 5, and there is an example in which it is produced under the same firing conditions as disclosed in Non-Patent Document 3. It is reported that the XRD pattern disclosed in Non-Patent Document 5 is the same as that disclosed in Non-Patent Document 3, and it is considered that the phosphor also has a glasselite structure.
  • an object of the present invention is to provide a phosphate phosphor that is a novel oxide that emits red light.
  • Another object of the present invention is to provide a novel phosphate phosphor having a crystal structure different from that of existing NaMgPO 4 : Eu 2+ and NaMgPO 4 : Ce 3+ and exhibiting different light emission characteristics.
  • the inventors of the present invention when producing existing NaMgPO 4 : Eu 2+ , which is reported to emit blue light, were baked at a temperature higher than the normal firing temperature (about 950 ° C.). It has been found that it has a different crystal structure and emits light with a color different from that of existing reports, and has come to the present invention.
  • the present invention has the following configuration / features.
  • (Aspect 1) It contains NaMgPO 4 activated by luminescent ions including Eu, the activation concentration of the luminescent ions is 1 to 10 mol%, the crystal structure of the NaMgPO 4 is an olivine-related structure, and emits light in orange to red A phosphate phosphor characterized by that.
  • (Aspect 2) The phosphate phosphor according to aspect 1, wherein a part of P is substituted with at least one element of the group consisting of Si and Al.
  • Aspect 5 The phosphate phosphor according to any one of aspects 1 to 4, wherein a part of Na or Mg is substituted with at least one element of the group consisting of K, Li, Ca, and Sr.
  • Aspect 6) A method for producing a phosphate phosphor according to any one of Embodiments 1 to 5, A mixing step of mixing a compound containing an element contained in the phosphate phosphor as a raw material; A firing step of firing the mixture in air or in a reducing atmosphere; Including, and In the firing step, the mixture is melted and then cooled.
  • the present invention for example, it is possible to provide a red light-emitting phosphor made of a pure oxide. Therefore, the drawbacks of the red light emitting phosphors made of conventional nitrides and sulfides are solved. For example, a water-resistant red light-emitting phosphor can be easily and inexpensively manufactured.
  • FIG. 2 is a diagram showing a powder X-ray diffraction pattern of the phosphor of Example 1.
  • FIG. It is the figure which showed the Rietveld analysis result using the diffraction pattern of Example 1. It is the figure which showed the crystal structure of the fluorescent substance of Example 1 obtained by the said analysis.
  • FIG. 3 is a diagram showing the fluorescence characteristics of the phosphor of Example 1.
  • FIG. 3 is a diagram showing thermal quenching characteristics of the phosphor of Example 1.
  • 2 is an SEM image showing phosphor particles of Example 1.
  • FIG. 6 is a diagram showing a powder X-ray diffraction pattern of the phosphor of Example 2.
  • FIG. FIG. 6 is a diagram showing the fluorescence characteristics of the phosphor of Example 2.
  • Example 2 It is the figure which showed the thermal-quenching characteristic of the fluorescent substance of Example 2.
  • 3 is an SEM image showing phosphor particles of Example 2.
  • 6 is a diagram showing a powder X-ray diffraction pattern of the phosphor of Example 3.
  • FIG. 6 is a diagram showing the fluorescence characteristics of the phosphor of Example 3.
  • FIG. 13 is a diagram showing the fluorescence characteristics of conventional NaMgPO 4 : Ce 3+ .
  • 6 is a diagram showing a powder X-ray diffraction pattern of the phosphor of Example 4.
  • FIG. It is the figure which showed the fluorescence characteristic of the fluorescent substance of Example 4.
  • 6 is a diagram showing a powder X-ray diffraction pattern of the phosphor of Example 5.
  • FIG. It is the figure which showed the fluorescence characteristic of the fluorescent substance of Example 5. It is the figure which showed the crystal structure of the conventional same kind of fluorescent substance.
  • the phosphate phosphor according to the first embodiment of the present invention includes NaMgPO 4 activated by luminescent ions including Eu, the activation concentration of luminescent ions is 1 to 10 mol% (mol%), and The crystal structure of NaMgPO 4 is an olivine-related structure.
  • concentration or other parameters in the present specification for example, when described as 1 to 10 mol%, it means a range of 1 mol% or more and 10 mol% or less.
  • concentration range of luminescent ions is not preferable because sufficient luminescence intensity cannot be obtained.
  • a preferred concentration range is 1 to 5 mol%, and a more preferred concentration range is 2 to 3 mol%.
  • concentration range of the luminescent ions in the embodiment described later is also determined from the viewpoint of the emission intensity, as in the first embodiment.
  • the phosphate phosphor of the present invention including the first embodiment is characterized by having an olivine-related structure.
  • the olivine-related structure is derived from a crystal structure similar to the ore olivine (olivine), a nesosilicate mineral that is a continuous solid solution between mafic olivine and iron olivine. Specifically, it has a tetrahedral site into which cations enter and two types of octahedral sites in the gap of the hexagonal close-packed structure of oxide ions.
  • the tetrahedral site has four oxygen atoms at the apex.
  • the octahedral site has six oxygen atoms at the apex.
  • silicon is arranged at the center of the tetrahedral site
  • magnesium or iron is arranged at the center of the octahedral site.
  • the phosphate phosphor of the present invention has a crystal structure different from the crystal structure (Glaserite type) reported so far for the existing NaMgPO 4 : Eu 2+ .
  • the phosphate fluorescent substance of the present invention having the above-mentioned olivine-related structure may have a strain larger than that of ore olivine.
  • the composition ratio of sodium, magnesium, phosphorus, and oxygen is not limited to 1: 1: 1: 4.
  • a phosphorus atom is arranged at the center of the tetrahedral site, sodium is mainly arranged at the center of the large octahedral site, and magnesium is mainly arranged at the center of the small octahedral site.
  • Each tetrahedral site and octahedral site may dissolve different cations so as to maintain an olivine-related structure.
  • Starting materials include: (1) a first compound containing Na (sodium) such as Na 2 CO 3 , NaNO 3 .6H 2 O, (2) MgO, Mg (NO 3 ) 2 .6H 2 O A second compound containing Mg (magnesium), a third compound containing a phosphate such as (3) NH 4 H 2 PO 4 , (NH 4 ) 2 HPO 4 , (4) Eu 2 O 3 , a fourth compound containing Eu (europium) such as EuCO 3 , Eu (NO 3 ) 2 is used.
  • a first compound containing Na (sodium) such as Na 2 CO 3 , NaNO 3 .6H 2 O, (2) MgO, Mg (NO 3 ) 2 .6H 2 O
  • a third compound containing a phosphate such as (3) NH 4 H 2 PO 4 , (NH 4 ) 2 HPO 4 , (4) Eu 2 O 3
  • the first, second, and third compounds do not necessarily have to be prepared separately, and use a compound that contains Na, Mg, and phosphate, such as MgHPO 4 and NaH 2 PO 4. Also good. These compounds may be solid (for example, powder) or liquid (solution state).
  • each of these raw materials is weighed according to the stoichiometric ratio and mixed.
  • the mixture is fired in air or in a reducing atmosphere.
  • the mixture is once melted and then cooled.
  • This firing technique can be achieved using, for example, an arc imaging furnace.
  • the arc imaging furnace is also called a condensing furnace, and is an optical device that condenses radiant energy (high-density heat energy flux) generated by arc discharge in a small region by an elliptical mirror.
  • a high radiance xenon short arc lamp or the like is used as the light source, and the light condensing point reaches 1800 ° C. to 3000 ° C. at a very high temperature. Therefore, if the said mixture is arrange
  • the mixture that has been melted as described above is then rapidly cooled to become unable to withstand the distortion of the phase transition and to exhibit an olivine-related structural type phase.
  • the mixture exhibits a powder form having a desirable dimension as a phosphor.
  • the inventors of the present invention have a crystal structure different from that of known phosphors of the same kind reported in Non-Patent Document 3 and Non-Patent Document 5 and have different emission characteristics. The reason for exerting this is considered below.
  • NaMgPO 4 : Eu 2+ and NaMgPO 4 : Ce 3+ form at least two stable phases depending on the firing temperature in the production process.
  • the firing temperature of the known phosphor already reported is about 950 ° C. (first firing temperature range), and a first stable phase (stable at a relatively low temperature) that is fired (manufactured) near this temperature. Phase).
  • the present inventors further developed a phase developed at another firing temperature that has not been reported so far (in other words, a “second stable phase”, that is, a “stable phase at a relatively high temperature”). Think of it as discovered.
  • This “second stable phase”, ie, “stable phase at a relatively high temperature” is manifested by firing the mixture of starting materials at a temperature near or above the melting point at which each compound of the starting materials melts.
  • the melting point varies depending on each compound as a starting material, but is considered to be about 1100 to 1300 ° C. Therefore, in order to obtain this “second stable phase”, the firing temperature of the mixture of starting materials should be set near the melting point or higher (1100 ° C. or higher, that is, the second firing temperature range). Can be considered.
  • the arc imaging furnace which can heat a material for a short time was mentioned above as a baking method, if the above-mentioned 2nd baking temperature can be achieved, it will not necessarily be limited to this method.
  • a known solid phase method, a heating method using microwaves, or a method of heating after dissolving a starting material in a solution can be applied.
  • the phosphor of the second embodiment also has similar features such as having an olivine-related structure.
  • the phosphor of the second embodiment is different from the phosphor of the first embodiment in that the phosphor (P) in NaMgPO 4 is at least one member of the group consisting of silicon (Si) and aluminum (Al). The point is that it is replaced by an element. Due to this difference, the emission wavelength of the phosphor of the second embodiment is shifted to the longer wavelength side compared to the phosphor of the first embodiment. That is, the phosphor of the second embodiment emits deeper red light when excited with blue.
  • the manufacturing method of the phosphate phosphor according to the second embodiment is the same as that described above except that a compound containing Si or Al (for example, SiO 2 , Si 3 N 4 , Al 2 O 3 ) is further used as a starting material.
  • the first embodiment can be carried out in substantially the same process.
  • the phosphate phosphor according to the third embodiment includes NaMgPO 4 activated by luminescent ions containing Ce (cerium), the activation concentration of the luminescent ions is 1 to 5 mol%, and the NaMgPO 4
  • the crystal structure is an olivine-related structure.
  • the phosphor according to the third embodiment is also characterized by having an olivine-related structure like the phosphor according to the first embodiment.
  • the phosphor of the third embodiment is different from the phosphor of the first embodiment in that cerium (Ce) is used as a light emitting ion to be activated. Due to this difference, the phosphor of the third embodiment emits purple light when excited with blue.
  • the manufacturing method of the phosphor phosphor of the third embodiment uses a compound containing cerium ions (for example, CeO 2 , Ce (CH 3 COO) 3 .H 2 O) as the fourth compound as a starting material. Can be carried out in substantially the same process as in the first embodiment described above.
  • cerium ions for example, CeO 2 , Ce (CH 3 COO) 3 .H 2 O
  • the phosphate phosphor according to the fourth embodiment includes NaMgPO 4 activated by luminescent ions including Ce and Tb (terbium), and each activation concentration of the luminescent ions is 1 to 5 mol%, and
  • the crystal structure of the NaMgPO 4 is an olivine related structure.
  • the phosphor of the fourth embodiment has an olivine-related structure.
  • the phosphor of the fourth embodiment is different from the phosphor of the third embodiment in that not only cerium (Ce) but also terbium (Tb) is used as a luminescent ion to be dissolved. . Due to this difference, the phosphor of the fourth embodiment emits green light when excited in blue.
  • the manufacturing method of the phosphate phosphor according to the fourth embodiment is the same as that described above except that it is used for the compound containing Ce and the compound containing Tb (for example, Tb 4 O 7 ) as the fourth compound of the starting material. It can be carried out in substantially the same process as in the first embodiment.
  • a part of Na or Mg in NaMgPO 4 is made of K (potassium), Li (lithium), Ca (calcium), and Sr (strontium). It may be substituted with at least one element of the group.
  • K potassium
  • Li lithium
  • Ca calcium
  • Sr sinrontium
  • a compound containing the above-described substitution element for example, K 2 CO 3 , SrCO 3 , Li 2 CO 3 , CaCO 3 ) May be further used.
  • Example 1 includes NaMgPO 4 activated by luminescent ions containing Eu, the activation concentration of luminescent ions is 1 to 10 mol% (mol%), and the crystal structure of NaMgPO 4 is an olivine-related structure
  • a phosphor was prepared as follows. For the phosphor (sample) of Example 1, powder X-ray diffraction measurement with a powder X-ray diffractometer (manufactured by Mac Science Co., Ltd., MX-Labo), and spectrofluorimeter (manufactured by JASCO Corporation, FP-6500) was evaluated for fluorescence characteristics. In addition, the same evaluation was performed also about the below-mentioned Example and comparative example using the same apparatus.
  • FIG. 1 shows the powder X-ray diffraction pattern of Example 1. It was confirmed that the Eu concentration has a peak at approximately the same position from 1 mol% to 10 mol%, and that the diffraction pattern becomes strongest when the Eu concentration is 2.5 mol%. As a result, a similar crystal structure (an olivine-related structure described later) is obtained under any of the concentration conditions in Example 1, and the above structure is optimal when the Eu concentration is 2.5 mol%. It is inferred.
  • FIG. 2 shows the analysis results. Specifically, the upper part of FIG. 2 shows the pattern obtained by Rietveld analysis, while the middle part of FIG. 2 shows the actually observed diffraction pattern. Furthermore, the lower part of FIG. 2 shows the disagreement between the upper part (analysis result) and the middle part (actual observation result), and it was confirmed from the figure that both agree well.
  • FIG. 3 shows the crystal structure of the composite of Example 1 obtained by the Rietveld analysis described above.
  • the crystal structure shown in FIG. 3 has a tetrahedral site (PO 4 -coordinate tetrahedron) into which cations enter and two types of octahedral sites in the gap of the hexagonal close-packed structure of oxide ions.
  • PO 4 -coordinate tetrahedron tetrahedral site into which cations enter
  • two types of octahedral sites in the gap of the hexagonal close-packed structure of oxide ions in order to make the crystal structure easy to see, only the main first octahedron is shown three-dimensionally, while the subordinate second octahedron shows only cations located in the center.
  • the space group is Pnma (No. 62).
  • FIG. 4 is a graph showing the fluorescence characteristics of the phosphor of Example 1.
  • the spectrum indicated by the broken line on the left side is the excitation spectrum of Example 1
  • the spectrum indicated by the solid line on the right side is an emission spectrum corresponding to the excitation spectrum.
  • FIG. 4 shows fluorescence characteristics of phosphors having different Eu concentrations (1 mol%, 2.5 mol%, 5 mol%, and 10 mol%).
  • the display method of an excitation spectrum and an emission spectrum is the same also in the below-mentioned Example.
  • the phosphor of Example 1 is excited by light mainly having light intensity in the ultraviolet to blue region (300 nm to 460 nm), and has red emission (specifically, a peak near 620 nm). Emission spectrum). The highest emission intensity was exhibited when the Eu concentration was 2.5 mol%, and the decrease in emission intensity was confirmed in the order of the Eu concentration of 5 mol%, 1 mol%, and 10 mol%. Table 1 quantitatively shows the emission intensity (arbitrary unit: au) and the emission wavelength (nm) at the peak under each concentration condition in Example 1.
  • FIG. 5 shows the thermal quenching characteristics of the phosphor of Example 1 (when the Eu concentration is 2.5 mol%). Thermal quenching is also called thermal quenching and means a phenomenon in which the amount of light emission is reduced by heat (high temperature environment). From FIG. 5, even when the ambient temperature of the phosphor reaches 150 ° C., it is maintained at about 86% at room temperature (25 ° C.). This result is at a level that does not hinder the practical use of the phosphor.
  • FIG. 6 is an SEM image showing particles of the phosphor of Example 1 (when the Eu concentration is 2.5 mol%).
  • the resulting product is usually obtained in a state where the melt is solidified (a relatively small surface area such as a spherical surface) and therefore cannot be used as a phosphor. It was considered.
  • the sample of Example 1 was obtained as a powder as shown in FIG. 6 because it was cooled after melting.
  • the particle size of this powder is 5 ⁇ m to 15 ⁇ m, which is optimal as an LED phosphor.
  • Example 2 (Method for producing phosphor of Example 2)
  • SiO 2 manufactured by Kanto Chemical Co., Inc.
  • wet mixing, temporary firing, and firing in an arc imaging furnace were performed in the same manner as in Example 1.
  • appropriately adjusting the amount of adding Eu 2 O 3 and SiO 2 were synthesized with different phosphors Eu concentration and Si concentration.
  • FIG. 7 shows the powder X-ray diffraction pattern of Example 2.
  • the concentration of (Eu, Si) is almost (1 mol%, 1 mol%), (2.5 mol%, 2.5 mol%), (5 mol%, 5 mol%), and (10 mol%, 10 mol%). It was confirmed that there was a peak at the same position and that the diffraction pattern became strong and clear when the concentration of (Eu, Si) was 1 mol% to 2.5 mol%.
  • a crystal structure (olivine-related structure) similar to that in Example 1 was obtained under any concentration conditions in Example 2, and the concentrations of (Eu, Si) were (2.5 mol%, 2.5 mol%). ) Is presumed to be in an optimal state as the above structure.
  • FIG. 8A and 8B are diagrams showing the fluorescence characteristics of the phosphor of Example 2.
  • FIG. 8B shows the normalized emission intensity obtained by dividing the emission intensity under each condition by the maximum emission intensity under each condition.
  • the phosphor of Example 2 is excited by light mainly having light intensity in the ultraviolet to blue region (300 nm to 460 nm), and emits red (deep red) light (specifically, 625 to Shows an emission spectrum having a peak near 660 nm. The highest emission intensity was exhibited when both the Eu concentration and the Si concentration were 2.5 mol%.
  • Table 2 quantitatively shows the emission intensity (arbitrary unit; au) under each concentration condition in Example 2. Compared with the results of Example 1 shown in Table 1, it can be seen that in Example 2 shown in Table 2, the emission wavelength increases (shifts) as the Si concentration increases. Table 2 also shows the experimental results when the Eu concentration and the Si concentration are both 7 mol%.
  • FIG. 9 shows the thermal quenching characteristics of the phosphor of Example 2 (when both the Eu concentration and the Si concentration are 2.5 mol%). From FIG. 9, even when the ambient temperature of the phosphor reaches 150 ° C., it is maintained up to about 73% at room temperature (25 ° C.). This result is at a level that does not hinder the practical use of the phosphor.
  • FIG. 10 is an SEM image showing particles of the phosphor of Example 2 (when both the Eu concentration and the Si concentration are 2.5 mol%). As shown in FIG. 10, the synthesized phosphor is in the form of particles, and the size of each particle is 5 ⁇ m to 10 ⁇ m. Therefore, it was also found that the phosphor of Example 2 has a particle state suitable for the LED phosphor as in Example 1.
  • NaMgPO 4 activated by a luminescent ion containing Ce (cerium) is included, the activation concentration of the luminescent ion is 1 to 5 mol%, and the crystal structure of NaMgPO 4 is an olivine-related structure.
  • a phosphor was prepared as follows.
  • FIG. 11 shows the powder X-ray diffraction pattern of Example 3. Under any condition of Ce concentration of 1 mol%, 3 mol%, and 5 mol%, it has a peak at almost the same position, and the diffraction pattern is strongly evident when the concentration of Ce is 1 mol% or 3 mol%. confirmed. As a result, the same crystal structure (olivine-related structure) is obtained under any concentration conditions of Example 3, and the structure is in an optimal state when the Ce concentration is 1 mol% or 3 mol%. Is inferred.
  • FIG. 12 is a diagram showing the fluorescence characteristics of the phosphor of Example 3. From the results shown in FIG. 12, it was confirmed that the phosphor of Example 3 was excited in the ultraviolet region and showed purple emission. The highest emission intensity was exhibited when the Ce concentration was 3 mol%.
  • FIG. 13 the conventional NaMgPO had Gurase write structure 4: shows the fluorescence properties of Ce 3+ (Non-Patent Document 5). It was confirmed that both the excitation spectrum and the emission spectrum in FIG. 13 were completely different from the spectra of Example 3 shown in FIG.
  • Example 4 includes NaMgPO 4 activated by luminescent ions containing Ce and Tb (terbium), each activating ion concentration is 1 to 5 mol%, and the crystal structure of NaMgPO 4 is A phosphor having an olivine-related structure was prepared as follows.
  • Example 4 (Method for Producing Phosphor of Example 4)
  • Tb 4 O 7 manufactured by Kanto Chemical Co., Inc.
  • wet mixing, temporary firing, and firing in an arc imaging furnace were performed in the same manner as in Example 1.
  • FIG. 14 shows the powder X-ray diffraction pattern of Example 4. It was confirmed that the concentration of (Ce, Tb) had a peak at almost the same position under any of the conditions (3 mol%, 1 mol%), (3 mol%, 3 mol%), and (3 mol%, 5 mol%). . Thereby, it is inferred that the same crystal structure (olivine-related structure) is obtained under any concentration conditions of Example 4.
  • FIG. 15 is a diagram showing the fluorescence characteristics of the phosphor of Example 4. From this FIG. 15, it was confirmed that the phosphor of Example 4 was excited in the ultraviolet region and showed green emission (emission spectrum having a peak near 545 nm). The highest emission intensity was shown when the Tb concentration was 3 mol%.
  • the fluorescent substance substituted by Sr (strontium) was produced as follows.
  • Example 5 (Method for Producing Phosphor of Example 5)
  • K 2 CO 3 manufactured by Kanto Chemical Co., Inc.
  • SrCO 3 manufactured by Kanto Chemical Co., Ltd.
  • FIG. 16 shows the powder X-ray diffraction pattern of Example 5. It was confirmed that there was a peak at substantially the same position under any condition of K or Sr in the figure. Thus, even when a part of Na or Mg constituting NaMgPO 4 of Examples 1 to 4 is replaced with an alkali metal element or alkaline earth metal element such as K or Sr, the same crystal structure is obtained. It is inferred that (olivine-related structure) is obtained.
  • FIG. 17 is a diagram showing the fluorescence characteristics of the phosphor of Example 5. From FIG. 17, the phosphor of Example 5 was excited by light mainly having light intensity in the ultraviolet to blue region (300 nm to 460 nm), and had red light emission (specifically, a peak near 620 nm). Emission spectrum). That is, it was observed that the fluorescence characteristics similar to Example 1 were exhibited.
  • the phosphate phosphor produced according to the present invention can be expected as an inexpensive alternative to the existing red phosphor for white LEDs. Further, according to the present invention, the emission color can be freely changed by selecting the luminescent ions to be activated or adding Si. Therefore, the present invention has very high industrial utility value and applicability.

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Abstract

[Problem] To provide a phosphate phosphor consisting of a novel oxide that emits red light. [Solution] This phosphate phosphor is characterized in that: said phosphate phosphor contains NaMgPO4 activated by light-emitting ions including europium; the activation concentration of said light-emitting ions is between 1 and 10 mol.%, inclusive; the NaMgPO4 exhibits an olivine-like crystal structure; and this phosphate phosphor emits light of an orange to red color. To make this phosphate phosphor emit light of a somewhat deep red color, some of the phosphorus should be replaced by silicon and/or aluminum. In a firing step for manufacturing such phosphate phosphors, a mixture of starting materials is preferably cooled after being melted.

Description

リン酸塩蛍光体及びリン酸塩蛍光体の製造方法Phosphate phosphor and method for producing phosphate phosphor
 本発明は、既存のNaMgPO:Eu2+やNaMgPO:Ce3+とは異なる結晶構造を有し、異なる発光特性を発揮する新規なリン酸塩蛍光体に関するものである。 The present invention relates to a novel phosphate phosphor having a crystal structure different from existing NaMgPO 4 : Eu 2+ and NaMgPO 4 : Ce 3+ and exhibiting different light emission characteristics.
 近年、赤色に発光するLED用蛍光体の開発が注目されている。青色光で励起可能な公知の赤色発光蛍光体は、ほとんどが窒化物や硫化物からなり、純粋な酸化物で構成された実用的な材料は少ない。 In recent years, the development of LED phosphors that emit red light has attracted attention. Most of the known red light-emitting phosphors that can be excited by blue light are composed of nitrides or sulfides, and there are few practical materials composed of pure oxides.
 窒化物からなる公知の赤色発光蛍光体には、CaAlSiN:Eu2+が挙げられる(非特許文献1を参照)。しかしながら、このような窒化物を原料とした蛍光体は、その作製に際して極めて高い焼成温度(例えば、1900℃程度)や加圧炉が必要になる等の問題点が指摘されている。 A known red light-emitting phosphor made of nitride includes CaAlSiN 3 : Eu 2+ (see Non-Patent Document 1). However, it has been pointed out that such a phosphor using nitride as a raw material has problems such as extremely high firing temperature (for example, about 1900 ° C.) and the need for a pressure furnace.
 一方、硫化物からなる公知の赤色発光蛍光体には、CaS:Eu2+が挙げられる(非特許文献2を参照)。しかしながら、このような硫化物を原料とした蛍光体は、耐水性が低いこと等の問題点が指摘されている。 On the other hand, CaS: Eu <2+> is mentioned as a well-known red light emission fluorescent substance which consists of sulfides (refer nonpatent literature 2). However, such phosphors using sulfides as raw materials have been pointed out problems such as low water resistance.
 ところで、酸化物の一つであるNaMgPO:Eu2+は、青色に発光すると報告されている(非特許文献3を参照)。非特許文献3に開示の蛍光体は、具体的には、950℃及び5時間の焼成条件で作製され、240~410nmの範囲で励起され、青発光ピーク波長が437nmを有した青色発光を示すものである。また、NaMgPOと同種の蛍光体として、MgNa(POが提案され、グラセライト型の構造を有することが既に報告されている(本願の図18及び非特許文献4を参照)。 Incidentally, NaMgPO 4 : Eu 2+ , which is one of oxides, has been reported to emit blue light (see Non-Patent Document 3). Specifically, the phosphor disclosed in Non-Patent Document 3 is produced under firing conditions of 950 ° C. and 5 hours, is excited in the range of 240 to 410 nm, and exhibits blue emission with a blue emission peak wavelength of 437 nm. Is. Further, Mg 3 Na 3 (PO 4 ) 3 has been proposed as a phosphor of the same kind as NaMgPO 4 and has already been reported to have a glasselite type structure (see FIG. 18 of this application and Non-Patent Document 4). ).
 なお、NaMgPO:Ce3+も、非特許文献5に開示されており、非特許文献3に開示の焼成条件と同様の条件で作製された例がある。非特許文献5に開示のXRDパターンは、非特許文献3に開示のものと同様であったとの報告されており、当該蛍光体もグラセライト型構造を有すると考えられる。 NaMgPO 4 : Ce 3+ is also disclosed in Non-Patent Document 5, and there is an example in which it is produced under the same firing conditions as disclosed in Non-Patent Document 3. It is reported that the XRD pattern disclosed in Non-Patent Document 5 is the same as that disclosed in Non-Patent Document 3, and it is considered that the phosphor also has a glasselite structure.
 そこで、本発明は上記問題点に鑑み、赤色に発光する新規な酸化物であるリン酸塩蛍光体を提供することを目的とする。 Therefore, in view of the above problems, an object of the present invention is to provide a phosphate phosphor that is a novel oxide that emits red light.
 また、本発明は、既存のNaMgPO:Eu2+やNaMgPO:Ce3+とは異なる結晶構造を有し、異なる発光特性を発揮する新規なリン酸塩蛍光体を提供することを目的とする。 Another object of the present invention is to provide a novel phosphate phosphor having a crystal structure different from that of existing NaMgPO 4 : Eu 2+ and NaMgPO 4 : Ce 3+ and exhibiting different light emission characteristics.
 本発明者らは、青色発光すると報告されている既存のNaMgPO:Eu2+を製造するに際し、通常の焼成温度(950℃程度)よりも高い温度で焼成してみたところ、既存の報告とは異なる結晶構造を有し、かつ、既存の報告とは異なる色で発光することを見出し、本発明に想到するに至った。 The inventors of the present invention, when producing existing NaMgPO 4 : Eu 2+ , which is reported to emit blue light, were baked at a temperature higher than the normal firing temperature (about 950 ° C.). It has been found that it has a different crystal structure and emits light with a color different from that of existing reports, and has come to the present invention.
 すなわち本発明は、以下の構成・特徴を備えるものである。
(態様1)
 Euを含んだ発光イオンによって賦活されたNaMgPOを含み、前記発光イオンの賦活濃度は1~10mol%であり、前記NaMgPOの結晶構造がオリビン関連構造であり、かつ、橙色~赤色に発光することを特徴とするリン酸塩蛍光体。
(態様2)
 Pの一部がSi及びAlからなる群の少なくとも一種の元素で置換されていることを特徴とする態様1に記載のリン酸塩蛍光体。
(態様3)
 Ceを含んだ発光イオンによって賦活されたNaMgPOを含み、前記発光イオンの賦活濃度は1~5mol%であり、かつ、前記NaMgPOの結晶構造がオリビン関連構造であることを特徴とするリン酸塩蛍光体。
(態様4)
 Ce及びTbを含んだ発光イオンによって賦活されたNaMgPOを含み、前記発光イオンの各賦活濃度は1~5mol%であり、かつ、前記NaMgPOの結晶構造がオリビン関連構造であることを特徴とするリン酸塩蛍光体。
(態様5)
 Na又はMgの一部が、K、Li、Ca、及びSrからなる群の少なくとも一種の元素で置換されていることを特徴とする態様1~4のいずれかに記載のリン酸塩蛍光体。
(態様6)
 態様1~5のいずれかに記載のリン酸塩蛍光体の製造方法であって、
 前記リン酸塩蛍光体が含有する元素を含んだ化合物を原料として混合する混合工程と、
 混合物を空気中又は還元雰囲気下で焼成する焼成工程と、
 を含み、かつ、
 前記焼成工程では、前記混合物を溶融させた後に、冷却することを特徴とする製造方法。
That is, the present invention has the following configuration / features.
(Aspect 1)
It contains NaMgPO 4 activated by luminescent ions including Eu, the activation concentration of the luminescent ions is 1 to 10 mol%, the crystal structure of the NaMgPO 4 is an olivine-related structure, and emits light in orange to red A phosphate phosphor characterized by that.
(Aspect 2)
The phosphate phosphor according to aspect 1, wherein a part of P is substituted with at least one element of the group consisting of Si and Al.
(Aspect 3)
It includes NaMgPO 4 which is activated by emitting ions containing Ce, activation concentration of the luminescent ions is 1 ~ 5 mol%, and phosphoric acid, wherein the crystal structure of the NaMgPO 4 is olivine related structures Salt phosphor.
(Aspect 4)
It contains NaMgPO 4 activated by luminescent ions including Ce and Tb, each activating ion concentration is 1 to 5 mol%, and the crystal structure of NaMgPO 4 is an olivine-related structure. Phosphate phosphor.
(Aspect 5)
The phosphate phosphor according to any one of aspects 1 to 4, wherein a part of Na or Mg is substituted with at least one element of the group consisting of K, Li, Ca, and Sr.
(Aspect 6)
A method for producing a phosphate phosphor according to any one of Embodiments 1 to 5,
A mixing step of mixing a compound containing an element contained in the phosphate phosphor as a raw material;
A firing step of firing the mixture in air or in a reducing atmosphere;
Including, and
In the firing step, the mixture is melted and then cooled.
 本発明によれば、例えば、純粋な酸化物からなる赤色発光蛍光体を提供することができる。従って、従来の窒化物や硫化物からなる赤色発光蛍光体の欠点を解決するものとなる。例えば、耐水性のある赤色発光蛍光体を容易かつ安価に製造できることができる。 According to the present invention, for example, it is possible to provide a red light-emitting phosphor made of a pure oxide. Therefore, the drawbacks of the red light emitting phosphors made of conventional nitrides and sulfides are solved. For example, a water-resistant red light-emitting phosphor can be easily and inexpensively manufactured.
実施例1の蛍光体の粉末X線回折パターンを示した図である。2 is a diagram showing a powder X-ray diffraction pattern of the phosphor of Example 1. FIG. 実施例1の回折パターンを利用したリートベルト解析結果を示した図である。It is the figure which showed the Rietveld analysis result using the diffraction pattern of Example 1. 上記解析によって得られた実施例1の蛍光体の結晶構造を示した図である。It is the figure which showed the crystal structure of the fluorescent substance of Example 1 obtained by the said analysis. 実施例1の蛍光体の蛍光特性を示した図である。FIG. 3 is a diagram showing the fluorescence characteristics of the phosphor of Example 1. 実施例1の蛍光体の熱消光特性を示した図である。FIG. 3 is a diagram showing thermal quenching characteristics of the phosphor of Example 1. 実施例1の蛍光体の粒子を示したSEM画像である。2 is an SEM image showing phosphor particles of Example 1. FIG. 実施例2の蛍光体の粉末X線回折パターンを示した図である。6 is a diagram showing a powder X-ray diffraction pattern of the phosphor of Example 2. FIG. 実施例2の蛍光体の蛍光特性を示した図である。FIG. 6 is a diagram showing the fluorescence characteristics of the phosphor of Example 2. 実施例2の蛍光体の熱消光特性を示した図である。It is the figure which showed the thermal-quenching characteristic of the fluorescent substance of Example 2. 実施例2の蛍光体の粒子を示したSEM画像である。3 is an SEM image showing phosphor particles of Example 2. 実施例3の蛍光体の粉末X線回折パターンを示した図である。6 is a diagram showing a powder X-ray diffraction pattern of the phosphor of Example 3. FIG. 実施例3の蛍光体の蛍光特性を示した図である。FIG. 6 is a diagram showing the fluorescence characteristics of the phosphor of Example 3. 図13は、従来のNaMgPO:Ce3+の蛍光特性を示した図である。FIG. 13 is a diagram showing the fluorescence characteristics of conventional NaMgPO 4 : Ce 3+ . 実施例4の蛍光体の粉末X線回折パターンを示した図である。6 is a diagram showing a powder X-ray diffraction pattern of the phosphor of Example 4. FIG. 実施例4の蛍光体の蛍光特性を示した図である。It is the figure which showed the fluorescence characteristic of the fluorescent substance of Example 4. 実施例5の蛍光体の粉末X線回折パターンを示した図である。6 is a diagram showing a powder X-ray diffraction pattern of the phosphor of Example 5. FIG. 実施例5の蛍光体の蛍光特性を示した図である。It is the figure which showed the fluorescence characteristic of the fluorescent substance of Example 5. 従来の同種の蛍光体の結晶構造を示した図である。It is the figure which showed the crystal structure of the conventional same kind of fluorescent substance.
 (第1実施形態; 新規構造を有した赤色発光リン酸塩蛍光体)
 本発明の第1実施形態に係るリン酸塩蛍光体は、Euを含んだ発光イオンによって賦活されたNaMgPOを含み、発光イオンの賦活濃度は1~10mol%(モル%)であり、かつ、NaMgPOの結晶構造がオリビン関連構造である。なお、本明細書における濃度或いはその他のパラメータの単位表記として、例えば1~10mol%と記載した場合は、1mol%以上10mol%以下の範囲を意味するものとする。
(First embodiment; red light-emitting phosphate phosphor having a novel structure)
The phosphate phosphor according to the first embodiment of the present invention includes NaMgPO 4 activated by luminescent ions including Eu, the activation concentration of luminescent ions is 1 to 10 mol% (mol%), and The crystal structure of NaMgPO 4 is an olivine-related structure. In addition, as a unit notation of concentration or other parameters in the present specification, for example, when described as 1 to 10 mol%, it means a range of 1 mol% or more and 10 mol% or less.
 ここで、発光イオン(Eu)の上述の濃度範囲の下限あるいは上限を超えると、十分な発光強度を得られなくなるため、好ましくない。加えて、好適な濃度範囲は1~5mol%であり、さらに好適な濃度範囲は、2~3mol%である。なお、後述の実施形態の発光イオンの濃度範囲も、第1実施形態同様に、発光強度の観点から決定されている。 Here, exceeding the lower limit or the upper limit of the above-described concentration range of luminescent ions (Eu) is not preferable because sufficient luminescence intensity cannot be obtained. In addition, a preferred concentration range is 1 to 5 mol%, and a more preferred concentration range is 2 to 3 mol%. In addition, the concentration range of the luminescent ions in the embodiment described later is also determined from the viewpoint of the emission intensity, as in the first embodiment.
 (第1実施形態の蛍光体の結晶構造及び発光特性)
 第1実施形態を含め本発明のリン酸塩蛍光体は、上述のように、オリビン(olivine)関連構造を有することを特徴とする。
(Crystal structure and emission characteristics of the phosphor of the first embodiment)
As described above, the phosphate phosphor of the present invention including the first embodiment is characterized by having an olivine-related structure.
 (オリビン関連構造)
 ここで、オリビン関連構造とは、苦土かんらん石と鉄かんらん石との間の連続固溶体であるネソケイ酸塩鉱物である鉱石オリビン(かんらん石)に類似した結晶構造から由来しており、具体的には酸化物イオンの六方最密充填構造の隙間に、陽イオンが入る四面体サイト及び二種類の八面体サイトを有する。四面体サイトは頂点に4つの酸素原子を有する。八面体サイトは頂点に6つの酸素原子を有する。なお、鉱石のオリビン(かんらん石)では四面体サイトの中心にはケイ素が配置され、八面体サイトの中心にマグネシウムまたは鉄が配置される。
(Olivine-related structure)
Here, the olivine-related structure is derived from a crystal structure similar to the ore olivine (olivine), a nesosilicate mineral that is a continuous solid solution between mafic olivine and iron olivine. Specifically, it has a tetrahedral site into which cations enter and two types of octahedral sites in the gap of the hexagonal close-packed structure of oxide ions. The tetrahedral site has four oxygen atoms at the apex. The octahedral site has six oxygen atoms at the apex. In the ore olivine (olivine), silicon is arranged at the center of the tetrahedral site, and magnesium or iron is arranged at the center of the octahedral site.
 つまり、本発明のリン酸塩蛍光体は、既存のNaMgPO:Eu2+について今までに報告されている結晶構造(グラセライト(Glaserite)型)とは異なる結晶構造を有することが極めて興味深い。なお、上述のオリビン関連構造を持つ本発明のリン酸塩蛍光体は、鉱石のオリビンよりも大きな歪みを有してもよい。そして、蛍光体の母体NaMgPOにおいて、ナトリウム、マグネシウム、リン、及び酸素の組成比は、1:1:1:4に限定されない。本発明のリン酸塩蛍光体は、四面体サイトの中心にはリン原子が配置され、大きな八面体サイトの中心には主としてナトリウム、小さな八面体サイトの中心には主としてマグネシウムが配置される。それぞれの四面体サイトおよび八面体サイトはオリビン関連構造を保つように異なる陽イオンを固溶してもよい。 That is, it is extremely interesting that the phosphate phosphor of the present invention has a crystal structure different from the crystal structure (Glaserite type) reported so far for the existing NaMgPO 4 : Eu 2+ . In addition, the phosphate fluorescent substance of the present invention having the above-mentioned olivine-related structure may have a strain larger than that of ore olivine. In the phosphor host NaMgPO 4 , the composition ratio of sodium, magnesium, phosphorus, and oxygen is not limited to 1: 1: 1: 4. In the phosphate phosphor of the present invention, a phosphorus atom is arranged at the center of the tetrahedral site, sodium is mainly arranged at the center of the large octahedral site, and magnesium is mainly arranged at the center of the small octahedral site. Each tetrahedral site and octahedral site may dissolve different cations so as to maintain an olivine-related structure.
 この結晶構造の違い等により、既存の同種の蛍光体とは全く異なる発光特性を発揮する。つまり、既存の同種の蛍光体は紫外励起波長で青色に発光すると報告されているが、本発明の蛍光体は青色励起波長で、橙色~赤色に発光することが判明したのである。 Due to the difference in crystal structure, etc., it exhibits light emission characteristics that are completely different from existing phosphors of the same type. In other words, it has been reported that the same type of existing phosphor emits blue light at the ultraviolet excitation wavelength, but the phosphor of the present invention emits light from orange to red at the blue excitation wavelength.
 (第1実施形態の蛍光体の製造方法)
 出発原料には、(1)NaCO、NaNO・6HO、のようなNa(ナトリウム)を含んだ第1化合物、(2)MgO、Mg(NO・6HOのようなMg(マグネシウム)を含んだ第2化合物、(3)NHPO、(NHHPO、のようなリン酸塩を含んだ第3化合物、(4)Eu、EuCO、Eu(NOのようなEu(ユウロピウム)を含んだ第4化合物を用いる。なお、第1・第2・第3化合物は、必ずしも別個に用意する必要は無く、MgHPOやNaHPO等のように、NaやMgやリン酸塩を併せて含んだ化合物を用いても良い。なお、これらの化合物は、固体(例えば、粉状)であっても、液体(溶液状態)であってもよい。
(Method for Producing Phosphor of First Embodiment)
Starting materials include: (1) a first compound containing Na (sodium) such as Na 2 CO 3 , NaNO 3 .6H 2 O, (2) MgO, Mg (NO 3 ) 2 .6H 2 O A second compound containing Mg (magnesium), a third compound containing a phosphate such as (3) NH 4 H 2 PO 4 , (NH 4 ) 2 HPO 4 , (4) Eu 2 O 3 , a fourth compound containing Eu (europium) such as EuCO 3 , Eu (NO 3 ) 2 is used. The first, second, and third compounds do not necessarily have to be prepared separately, and use a compound that contains Na, Mg, and phosphate, such as MgHPO 4 and NaH 2 PO 4. Also good. These compounds may be solid (for example, powder) or liquid (solution state).
 その後、これらの各原料を化学量論比に従って秤量し、混合する。混合物は、空気中又は還元雰囲気下で焼成される。 After that, each of these raw materials is weighed according to the stoichiometric ratio and mixed. The mixture is fired in air or in a reducing atmosphere.
 (焼成工程)
 本発明の焼成工程では、一旦、混合物を溶融させた後に、冷却することが好ましい。この焼成手法は、例えば、アークイメージング炉を用いて達成可能である。ここで、アークイメージング炉とは、集光炉とも呼ばれ、アーク放電によって生じる放射エネルギー(高密度の熱エネルギー束)を、楕円ミラーで小領域に集光させる光学装置である。光源には高放射輝度のキセノンショートアークランプなどが使用され、集光点では極めて高い温度で1800℃~3000℃に達する。従って、集光点に上記混合物を配置すれば、上述のように極めて高い温度で焼成がなされる。
(Baking process)
In the firing step of the present invention, it is preferable that the mixture is once melted and then cooled. This firing technique can be achieved using, for example, an arc imaging furnace. Here, the arc imaging furnace is also called a condensing furnace, and is an optical device that condenses radiant energy (high-density heat energy flux) generated by arc discharge in a small region by an elliptical mirror. A high radiance xenon short arc lamp or the like is used as the light source, and the light condensing point reaches 1800 ° C. to 3000 ° C. at a very high temperature. Therefore, if the said mixture is arrange | positioned at a condensing point, as mentioned above, baking will be made at a very high temperature.
 上述のように溶融した混合物は、その後、急冷されることで、相転移の歪みに耐えられなくなりオリビン関連構造型の相を呈するようになる。また、その混合物は、実施例で後述するように、蛍光体として望ましい寸法を有した粉末状を呈するようになる。 The mixture that has been melted as described above is then rapidly cooled to become unable to withstand the distortion of the phase transition and to exhibit an olivine-related structural type phase. In addition, as will be described later in Examples, the mixture exhibits a powder form having a desirable dimension as a phosphor.
(焼成温度の影響)
 本発明者らは、非特許文献3や非特許文献5等で報告された公知の同種の蛍光体と比べて、本発明の蛍光体が異なった結晶構造を有し、かつ、異なった発光特性を発揮する理由を以下に考察する。
(Influence of firing temperature)
The inventors of the present invention have a crystal structure different from that of known phosphors of the same kind reported in Non-Patent Document 3 and Non-Patent Document 5 and have different emission characteristics. The reason for exerting this is considered below.
 すなわち、NaMgPO:Eu2+やNaMgPO:Ce3+は、その製造工程における焼成温度によって、少なくとも2つの安定な相が形成されるものと本発明者らは考える。既に報告された公知の蛍光体の焼成温度は950℃程度(第1の焼成温度の範囲)であり、この温度付近で焼成(製造)される第1の安定な相(比較的低温で安定な相)が存在する。そして、本発明者らは、さらに、今までに報告されていない別の焼成温度で発現する相(言い換えれば、「第2の安定な相」、つまり「比較的高温で安定な相」)を発見したものと考える。 That is, the present inventors consider that NaMgPO 4 : Eu 2+ and NaMgPO 4 : Ce 3+ form at least two stable phases depending on the firing temperature in the production process. The firing temperature of the known phosphor already reported is about 950 ° C. (first firing temperature range), and a first stable phase (stable at a relatively low temperature) that is fired (manufactured) near this temperature. Phase). Further, the present inventors further developed a phase developed at another firing temperature that has not been reported so far (in other words, a “second stable phase”, that is, a “stable phase at a relatively high temperature”). Think of it as discovered.
 この「第2の安定な相」すなわち「比較的高温で安定な相」は、出発原料の各化合物が溶融する融点近傍又は融点を超える温度にて出発原料の混合物を焼成することによって、発現するものと考える。なお、出発原料の各化合物に依ってその融点は上下するが、1100~1300℃程度であると考えられる。従って、この「第2の安定な相」を得るためには、出発原料の混合物の焼成温度を、融点近傍又はそれより高温(1100℃以上、つまり第2の焼成温度の範囲)に設定することが考えられる。 This “second stable phase”, ie, “stable phase at a relatively high temperature” is manifested by firing the mixture of starting materials at a temperature near or above the melting point at which each compound of the starting materials melts. Think of things. The melting point varies depending on each compound as a starting material, but is considered to be about 1100 to 1300 ° C. Therefore, in order to obtain this “second stable phase”, the firing temperature of the mixture of starting materials should be set near the melting point or higher (1100 ° C. or higher, that is, the second firing temperature range). Can be considered.
 なお、焼成方法として、短時間で材料を加熱できるアークイメージング炉を上述したが、上述の第2の焼成温度を達成できれば、必ずしもこの方法に限定されない。例えば、公知の固相法、マイクロ波を利用した加熱法、出発原料を溶液に溶かした後に加熱する方法も適用可能である。 In addition, although the arc imaging furnace which can heat a material for a short time was mentioned above as a baking method, if the above-mentioned 2nd baking temperature can be achieved, it will not necessarily be limited to this method. For example, a known solid phase method, a heating method using microwaves, or a method of heating after dissolving a starting material in a solution can be applied.
 (第2実施形態; 新規構造を有した赤色発光リン酸塩蛍光体)
 第2実施形態の蛍光体も、第1実施形態の蛍光体と同様に、オリビン関連構造を有する点など同様の特徴を有する。しかしながら、第1実施形態の蛍光体と異なる点として、第2実施形態の蛍光体は、NaMgPOにおけるリン(P)の一部がシリコン(Si)及びアルミニウム(Al)からなる群の少なくとも一種の元素で置換されている点である。この相違点により、第2実施形態の蛍光体では、第1実施形態の蛍光体に比べ、その発光波長が長波長側にシフトする。つまり、第2実施形態の蛍光体では、青色励起した際に、より深い赤色に発光することになる。
(Second Embodiment; red-emitting phosphor phosphor having a novel structure)
Similarly to the phosphor of the first embodiment, the phosphor of the second embodiment also has similar features such as having an olivine-related structure. However, the phosphor of the second embodiment is different from the phosphor of the first embodiment in that the phosphor (P) in NaMgPO 4 is at least one member of the group consisting of silicon (Si) and aluminum (Al). The point is that it is replaced by an element. Due to this difference, the emission wavelength of the phosphor of the second embodiment is shifted to the longer wavelength side compared to the phosphor of the first embodiment. That is, the phosphor of the second embodiment emits deeper red light when excited with blue.
 (第2実施形態の蛍光体の製造方法)
 第2実施形態のリン酸塩蛍光体の製造方法は、出発原料として更に、SiやAlを含んだ化合物(例えば、SiO、Si、Al)を更に用いる以外は、上述の第1実施形態の場合とほぼ同様の工程で実施可能である。
(Method for Producing Phosphor of Second Embodiment)
The manufacturing method of the phosphate phosphor according to the second embodiment is the same as that described above except that a compound containing Si or Al (for example, SiO 2 , Si 3 N 4 , Al 2 O 3 ) is further used as a starting material. The first embodiment can be carried out in substantially the same process.
 (第3実施形態; 新規構造を有した紫色発光リン酸塩蛍光体)
 第3実施形態に係るリン酸塩蛍光体は、Ce(セリウム)を含んだ発光イオンによって賦活されたNaMgPOを含み、前記発光イオンの賦活濃度は1~5mol%であり、かつ、前記NaMgPOの結晶構造がオリビン関連構造であることを特徴とする。
(Third embodiment; a purple-emitting phosphor phosphor having a novel structure)
The phosphate phosphor according to the third embodiment includes NaMgPO 4 activated by luminescent ions containing Ce (cerium), the activation concentration of the luminescent ions is 1 to 5 mol%, and the NaMgPO 4 The crystal structure is an olivine-related structure.
 (第3実施形態の蛍光体の結晶構造及び発光特性)
 第3実施形態の蛍光体も、第1実施形態の蛍光体と同様に、オリビン関連構造を有することを特徴とする。しかしながら、第1実施形態の蛍光体と異なる点として、第3実施形態の蛍光体は、賦活させる発光イオンとしてセリウム(Ce)を使用している点である。この相違点により、第3実施形態の蛍光体では、青色励起した際に紫色に発光することになる。
(Crystal structure and emission characteristics of phosphor of the third embodiment)
The phosphor according to the third embodiment is also characterized by having an olivine-related structure like the phosphor according to the first embodiment. However, the phosphor of the third embodiment is different from the phosphor of the first embodiment in that cerium (Ce) is used as a light emitting ion to be activated. Due to this difference, the phosphor of the third embodiment emits purple light when excited with blue.
 一方、従来のNaMgPO:Ce3+は、グラセライト型構造を有し、紫外~紫色に発光することが知られている(非特許文献4,5を参照)。従って、第3実施形態は、従来の同種の材料に比べ、発光特性において大差は無いが、全く異なる結晶構造を有すると言える。 On the other hand, conventional NaMgPO 4 : Ce 3+ has a glasserite structure and is known to emit ultraviolet to purple light (see Non-Patent Documents 4 and 5). Therefore, it can be said that the third embodiment has a completely different crystal structure, although there is not much difference in light emission characteristics as compared with the same kind of conventional materials.
 (第3実施形態の蛍光体の製造方法)
 第3実施形態のリン酸塩蛍光体の製造方法は、出発原料の第4化合物として、セリウムイオンを含んだ化合物(例えば、CeO、Ce(CHCOO)・HO)を用いる以外は、上述の第1実施形態の場合とほぼ同様の工程で実施可能である。
(Method for Producing Phosphor of Third Embodiment)
The manufacturing method of the phosphor phosphor of the third embodiment uses a compound containing cerium ions (for example, CeO 2 , Ce (CH 3 COO) 3 .H 2 O) as the fourth compound as a starting material. Can be carried out in substantially the same process as in the first embodiment described above.
 (第4実施形態; 新規構造を有した緑色発光リン酸塩蛍光体)
 第4実施形態に係るリン酸塩蛍光体は、Ce及びTb(テルビウム)を含んだ発光イオンによって賦活されたNaMgPOを含み、前記発光イオンの各賦活濃度は1~5mol%であり、かつ、前記NaMgPOの結晶構造がオリビン関連構造である。
(Fourth embodiment; green light-emitting phosphate phosphor having a novel structure)
The phosphate phosphor according to the fourth embodiment includes NaMgPO 4 activated by luminescent ions including Ce and Tb (terbium), and each activation concentration of the luminescent ions is 1 to 5 mol%, and The crystal structure of the NaMgPO 4 is an olivine related structure.
 (第4実施形態の蛍光体の結晶構造及び発光特性)
 第4実施形態の蛍光体も、第3実施形態の蛍光体と同様に、オリビン関連構造を有することを特徴とする。しかしながら、第3実施形態の蛍光体と異なる点として、第4実施形態の蛍光体は、固溶させる発光イオンとしてセリウム(Ce)のみならず、テルビウム(Tb)をも使用している点である。この相違点により、第4実施形態の蛍光体では、青色励起した際に緑色に発光することになる。
(Crystal structure and emission characteristics of phosphor of fourth embodiment)
Similarly to the phosphor of the third embodiment, the phosphor of the fourth embodiment has an olivine-related structure. However, the phosphor of the fourth embodiment is different from the phosphor of the third embodiment in that not only cerium (Ce) but also terbium (Tb) is used as a luminescent ion to be dissolved. . Due to this difference, the phosphor of the fourth embodiment emits green light when excited in blue.
 (第4実施形態の蛍光体の製造方法)
 第4実施形態のリン酸塩蛍光体の製造方法は、出発原料の第4化合物として、Ceを含んだ上記化合物及びTbを含んだ化合物(例えば、Tb)に用いる以外は、上述の第1実施形態の場合とほぼ同様の工程で実施可能である。
(Method for Producing Phosphor of Fourth Embodiment)
The manufacturing method of the phosphate phosphor according to the fourth embodiment is the same as that described above except that it is used for the compound containing Ce and the compound containing Tb (for example, Tb 4 O 7 ) as the fourth compound of the starting material. It can be carried out in substantially the same process as in the first embodiment.
 (第1~第4実施形態を変形した形態)
 第1~第4実施形態のリン酸塩蛍光体の変形形態として、NaMgPOにおけるNa又はMgの一部が、K(カリウム)、Li(リチウム)、Ca(カルシウム)、及びSr(ストロンチウム)からなる群の少なくとも一種の元素で置換されていてもよい。これらの変形形態を製造するために、出発原料として、実施形態1~4の上述化合物の他、上記置換元素を含んだ化合物(例えば、KCO、SrCO、LiCO、CaCO)をさらに用いてよい。
(Modified form of the first to fourth embodiments)
As a modification of the phosphate phosphors of the first to fourth embodiments, a part of Na or Mg in NaMgPO 4 is made of K (potassium), Li (lithium), Ca (calcium), and Sr (strontium). It may be substituted with at least one element of the group. In order to produce these modified forms, as a starting material, in addition to the above-described compounds of Embodiments 1 to 4, a compound containing the above-described substitution element (for example, K 2 CO 3 , SrCO 3 , Li 2 CO 3 , CaCO 3 ) May be further used.
 以下、添付の図面を参照しながら本発明の具体的な実施例について説明するが、本発明はこれらの実施例に何等限定されるものではない。 Hereinafter, specific examples of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited to these examples.
 (実施例1の蛍光体)
 実施例1として、Euを含んだ発光イオンによって賦活されたNaMgPOを含み、発光イオンの賦活濃度が1~10mol%(モル%)であり、かつ、NaMgPOの結晶構造がオリビン関連構造である蛍光体を以下のように作製した。この実施例1の蛍光体(サンプル)に対して、粉末X線回折装置(マックサイエンス株式会社製、MX-Labo)での粉末X線回折測定と、分光蛍光光度計(日本分光株式会社製、FP-6500)での蛍光特性評価を行った。なお、後述の実施例や比較例についても同一の装置を用いて同様の評価を行った。
(Phosphor of Example 1)
Example 1 includes NaMgPO 4 activated by luminescent ions containing Eu, the activation concentration of luminescent ions is 1 to 10 mol% (mol%), and the crystal structure of NaMgPO 4 is an olivine-related structure A phosphor was prepared as follows. For the phosphor (sample) of Example 1, powder X-ray diffraction measurement with a powder X-ray diffractometer (manufactured by Mac Science Co., Ltd., MX-Labo), and spectrofluorimeter (manufactured by JASCO Corporation, FP-6500) was evaluated for fluorescence characteristics. In addition, the same evaluation was performed also about the below-mentioned Example and comparative example using the same apparatus.
 (実施例1の蛍光体の製造方法)
 出発原料にNaCO(株式会社豊島製作所製)、MgO(関東化学株式会社製)、NHPO(関東化学株式会社製)、Eu(信越化学工業株式会社製)を用い、それらをアセトンで湿式混合し、その混合物をアルミナボートに移し、400℃、4時間空気中で仮焼成した。その後、当該混合物を粉砕し、Ar/H(95%/5%)雰囲気下のアークイメージング炉(出力150A)で数秒間焼成した。なお、Euを添加する分量を適宜調節し、前記発光イオンの濃度がそれぞれ1mol%、2.5mol%、5mol%、10mol%となるように、蛍光体を合成した。
(Method for Producing Phosphor of Example 1)
Na 2 CO 3 (manufactured by Toshima Seisakusho), MgO (manufactured by Kanto Chemical Co., Ltd.), NH 4 H 2 PO 4 (manufactured by Kanto Chemical Co., Ltd.), Eu 2 O 3 (manufactured by Shin-Etsu Chemical Co., Ltd.) They were wet mixed with acetone and the mixture was transferred to an alumina boat and pre-calcined in air at 400 ° C. for 4 hours. Thereafter, the mixture was pulverized and fired for several seconds in an arc imaging furnace (output 150 A) in an Ar / H 2 (95% / 5%) atmosphere. The amount of Eu 2 O 3 added was appropriately adjusted, and phosphors were synthesized so that the concentrations of the luminescent ions were 1 mol%, 2.5 mol%, 5 mol%, and 10 mol%, respectively.
 (実施例1の蛍光体のXRDパターン)
 図1は、実施例1の粉末X線回折パターンを示す。Eu濃度が1mol%から10mol%まで、ほぼ同様の位置でピークを有すること、及び、Eu濃度が2.5mol%のときに回折パターンが最も強く明白になることが確認された。これにより、実施例1のいずれの濃度条件でも、同様の結晶構造(後述のオリビン関連構造)が得られており、Eu濃度が2.5mol%のときに上記構造として最適な状態となっていることが推察される。
(XRD pattern of the phosphor of Example 1)
FIG. 1 shows the powder X-ray diffraction pattern of Example 1. It was confirmed that the Eu concentration has a peak at approximately the same position from 1 mol% to 10 mol%, and that the diffraction pattern becomes strongest when the Eu concentration is 2.5 mol%. As a result, a similar crystal structure (an olivine-related structure described later) is obtained under any of the concentration conditions in Example 1, and the above structure is optimal when the Eu concentration is 2.5 mol%. It is inferred.
 (実施例1の蛍光体のリートベルト解析)
 Eu濃度が2.5mol%のときの回折パターンを利用してリートベルト(Rietveld)解析を行った。図2はその解析結果を示す。具体的には、図2の上段がリートベルト解析により得られたパターンを示す一方、図2の中段が実際に観測された回折パターンを示す。さらに、図2の下段は、上段(解析結果)と中段(実際の観測結果)との不一致具合を示すものであり、この図から双方がよく一致することが確認された。
(Rietveld analysis of the phosphor of Example 1)
Rietveld analysis was performed using the diffraction pattern when the Eu concentration was 2.5 mol%. FIG. 2 shows the analysis results. Specifically, the upper part of FIG. 2 shows the pattern obtained by Rietveld analysis, while the middle part of FIG. 2 shows the actually observed diffraction pattern. Furthermore, the lower part of FIG. 2 shows the disagreement between the upper part (analysis result) and the middle part (actual observation result), and it was confirmed from the figure that both agree well.
 (実施例1の蛍光体の結晶構造)
 図3は、上述のリートベルト解析によって得られた実施例1の合成物の結晶構造を示す。図3に示す結晶構造では、酸化物イオンの六方最密充填構造の隙間に、陽イオンが入る四面体サイト(PO配位の四面体)及び二種類の八面体サイトを有する。図3では、結晶構造を見やすくするため、主となる第1の八面体のみを立体的に示す一方、従となる第2の八面体は、中心に位置する陽イオンのみを示す。
(Crystal structure of the phosphor of Example 1)
FIG. 3 shows the crystal structure of the composite of Example 1 obtained by the Rietveld analysis described above. The crystal structure shown in FIG. 3 has a tetrahedral site (PO 4 -coordinate tetrahedron) into which cations enter and two types of octahedral sites in the gap of the hexagonal close-packed structure of oxide ions. In FIG. 3, in order to make the crystal structure easy to see, only the main first octahedron is shown three-dimensionally, while the subordinate second octahedron shows only cations located in the center.
 この図3に示す結晶構造から、実施例1の蛍光体が、これと同種の従来の蛍光体が有する結晶構造(図18を参照)とは全く異なった結晶構造(すなわち、オリビン関連構造)を有していることが観察された。また、この解析結果によれば、a=10.2701(8)Å,b=6.1729(5)Å,c=4.9347(4)Åとする斜方晶である。空間群はPnma(No.62)である。 From the crystal structure shown in FIG. 3, the phosphor of Example 1 has a completely different crystal structure (that is, an olivine-related structure) from the crystal structure (see FIG. 18) of the conventional phosphor of the same type. It was observed to have. Moreover, according to this analysis result, it is an orthorhombic crystal with a = 10.2701 (8) Å, b = 6.1729 (5) Å, and c = 4.9347 (4) Å. The space group is Pnma (No. 62).
 (実施例1の蛍光体の蛍光特性)
 図4は、実施例1の蛍光体の蛍光特性を示した図である。ここで、図4中、左側の破線で示したスペクトルは実施例1の励起スペクトルである一方、右側の実線で示したスペクトルは当該励起スペクトルに対応した発光スペクトルである。また、図4では、異なるEu濃度(1mol%、2.5mol%、5mol%、及び10mol%)を有した蛍光体の蛍光特性を示す。なお、励起スペクトル及び発光スペクトルの表示方法は、後述の実施例でも同様である。
(Fluorescence characteristics of the phosphor of Example 1)
FIG. 4 is a graph showing the fluorescence characteristics of the phosphor of Example 1. Here, in FIG. 4, the spectrum indicated by the broken line on the left side is the excitation spectrum of Example 1, while the spectrum indicated by the solid line on the right side is an emission spectrum corresponding to the excitation spectrum. FIG. 4 shows fluorescence characteristics of phosphors having different Eu concentrations (1 mol%, 2.5 mol%, 5 mol%, and 10 mol%). In addition, the display method of an excitation spectrum and an emission spectrum is the same also in the below-mentioned Example.
 この図4より、実施例1の蛍光体は、紫外から青色の領域(300nm~460nm)の光強度を主に有する光で励起し、赤色の発光(具体的には、620nm近くにピークを持った発光スペクトル)を示す。なお、最も高い発光強度を示したのはEu濃度が2.5mol%のときであり、Eu濃度が5mol%、1mol%、10mol%の順で発光強度の低下が確認された。なお、表1は、実施例1における各濃度条件での発光強度(任意単位; a.u.)及びピークでの発光波長(nm)を定量的に示す As shown in FIG. 4, the phosphor of Example 1 is excited by light mainly having light intensity in the ultraviolet to blue region (300 nm to 460 nm), and has red emission (specifically, a peak near 620 nm). Emission spectrum). The highest emission intensity was exhibited when the Eu concentration was 2.5 mol%, and the decrease in emission intensity was confirmed in the order of the Eu concentration of 5 mol%, 1 mol%, and 10 mol%. Table 1 quantitatively shows the emission intensity (arbitrary unit: au) and the emission wavelength (nm) at the peak under each concentration condition in Example 1.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
 (実施例1の蛍光体の熱消光)
 図5は、実施例1の蛍光体(Eu濃度が2.5mol%の場合)の熱消光特性を示す。熱消光とは、サーマル・クエンチングとも呼ばれ、熱(高温環境)によって発光量が低下する現象を意味する。図5より、蛍光体の周囲温度が150℃になったときでも、室温(25℃)時の86%程度まで維持されている。この結果は当該蛍光体の実用化に支障とならないレベルである。
(Thermal quenching of the phosphor of Example 1)
FIG. 5 shows the thermal quenching characteristics of the phosphor of Example 1 (when the Eu concentration is 2.5 mol%). Thermal quenching is also called thermal quenching and means a phenomenon in which the amount of light emission is reduced by heat (high temperature environment). From FIG. 5, even when the ambient temperature of the phosphor reaches 150 ° C., it is maintained at about 86% at room temperature (25 ° C.). This result is at a level that does not hinder the practical use of the phosphor.
 (実施例1の蛍光体の粒子)
 図6は、実施例1の蛍光体(Eu濃度が2.5mol%の場合)の粒子を示すSEM画像である。アークイメージング炉などを用いて出発原料の混合物を溶融した場合、その結果物は、通常、融液が固まった状態(球状などの表面積の比較的小さい状態)で得られるので、蛍光体として使用できないと考えられた。しかし、実施例1の試料では、溶融後、冷却を行っているせいか、図6に示すように、粉末として得られることが分かった。さらに、この粉末の粒子サイズが、LED用蛍光体として最適とされる5μm~15μmであることも判明した。
(Phosphor particles of Example 1)
FIG. 6 is an SEM image showing particles of the phosphor of Example 1 (when the Eu concentration is 2.5 mol%). When a mixture of starting materials is melted using an arc imaging furnace or the like, the resulting product is usually obtained in a state where the melt is solidified (a relatively small surface area such as a spherical surface) and therefore cannot be used as a phosphor. It was considered. However, it was found that the sample of Example 1 was obtained as a powder as shown in FIG. 6 because it was cooled after melting. Furthermore, it has been found that the particle size of this powder is 5 μm to 15 μm, which is optimal as an LED phosphor.
 (実施例2の蛍光体)
 第2実施例として、実施例1の蛍光体のように、Euを含んだ発光イオンによって賦活されたNaMgPOであるが、Pの一部がSiで置換されている蛍光体を以下のように作製した。
(Phosphor of Example 2)
As a second example, a phosphor in which NaMgPO 4 is activated by a luminescent ion containing Eu as in the phosphor of example 1, but a part of P is substituted with Si is as follows. Produced.
 (実施例2の蛍光体の製造方法)
 実施例2では、実施例1で使用した出発原料の他に、SiO(関東化学株式会社製)を用いた。これらの原料を用いて、実施例1の場合と同様に湿式混合、仮焼成、及びアークイメージング炉での焼成を行った。なお、Eu及びSiOを添加する分量を適宜調節し、Eu濃度及びSi濃度の異なる蛍光体を合成した。
(Method for producing phosphor of Example 2)
In Example 2, in addition to the starting material used in Example 1, SiO 2 (manufactured by Kanto Chemical Co., Inc.) was used. Using these raw materials, wet mixing, temporary firing, and firing in an arc imaging furnace were performed in the same manner as in Example 1. Incidentally, appropriately adjusting the amount of adding Eu 2 O 3 and SiO 2, were synthesized with different phosphors Eu concentration and Si concentration.
 (実施例2の蛍光体のXRDパターン)
 図7は、実施例2の粉末X線回折パターンを示す。(Eu,Si)の濃度が(1mol%,1mol%)、(2.5mol%,2.5mol%)、(5mol%,5mol%)、(10mol%,10mol%)のいずれの条件でも、ほぼ同様の位置でピークを有すること、及び、(Eu,Si)の濃度が1mol%~2.5mol%のときに回折パターンが強く明白になることが確認された。これにより、実施例2のいずれの濃度条件でも、実施例1と同様の結晶構造(オリビン関連構造)が得られており、(Eu,Si)の濃度が(2.5mol%,2.5mol%)のときに上記構造として最適な状態となっていることが推察される。
(XRD pattern of the phosphor of Example 2)
FIG. 7 shows the powder X-ray diffraction pattern of Example 2. The concentration of (Eu, Si) is almost (1 mol%, 1 mol%), (2.5 mol%, 2.5 mol%), (5 mol%, 5 mol%), and (10 mol%, 10 mol%). It was confirmed that there was a peak at the same position and that the diffraction pattern became strong and clear when the concentration of (Eu, Si) was 1 mol% to 2.5 mol%. As a result, a crystal structure (olivine-related structure) similar to that in Example 1 was obtained under any concentration conditions in Example 2, and the concentrations of (Eu, Si) were (2.5 mol%, 2.5 mol%). ) Is presumed to be in an optimal state as the above structure.
 (実施例2の蛍光体の蛍光特性)
 図8(a)及び(b)は、実施例2の蛍光体の蛍光特性を示した図である。特に、図8(b)は、各条件の発光強度を各条件の最大発光強度で除した規格化発光強度を示す。この図8より、実施例2の蛍光体は、紫外から青色の領域(300nm~460nm)の光強度を主に有する光で励起し、赤色(深い赤色)の発光(具体的には、625~660nm近くにピークを持った発光スペクトル)を示す。なお、最も高い発光強度を示したのはEu濃度及びSi濃度が共に2.5mol%のときである。なお、表2は、実施例2における各濃度条件での発光強度(任意単位; a.u.)を定量的に示す。表1に示した実施例1の結果と比較すると、表2に示した実施例2では、Si濃度が増加するに従って発光波長が増加(シフト)していることが分かる。なお、表2には、Eu濃度及びSi濃度が共に7mol%のときの実験結果も併せて示す。
(Fluorescence characteristics of the phosphor of Example 2)
8A and 8B are diagrams showing the fluorescence characteristics of the phosphor of Example 2. FIG. In particular, FIG. 8B shows the normalized emission intensity obtained by dividing the emission intensity under each condition by the maximum emission intensity under each condition. From FIG. 8, the phosphor of Example 2 is excited by light mainly having light intensity in the ultraviolet to blue region (300 nm to 460 nm), and emits red (deep red) light (specifically, 625 to Shows an emission spectrum having a peak near 660 nm. The highest emission intensity was exhibited when both the Eu concentration and the Si concentration were 2.5 mol%. Table 2 quantitatively shows the emission intensity (arbitrary unit; au) under each concentration condition in Example 2. Compared with the results of Example 1 shown in Table 1, it can be seen that in Example 2 shown in Table 2, the emission wavelength increases (shifts) as the Si concentration increases. Table 2 also shows the experimental results when the Eu concentration and the Si concentration are both 7 mol%.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
 (実施例2の蛍光体の熱消光)
 図9は、実施例2の蛍光体(Eu濃度及びSi濃度が共に2.5mol%のとき)の熱消光特性を示す。図9より、蛍光体の周囲温度が150℃になったときでも、室温(25℃)時の73%程度まで維持されている。この結果は当該蛍光体の実用化に支障とならないレベルである。
(Thermal quenching of the phosphor of Example 2)
FIG. 9 shows the thermal quenching characteristics of the phosphor of Example 2 (when both the Eu concentration and the Si concentration are 2.5 mol%). From FIG. 9, even when the ambient temperature of the phosphor reaches 150 ° C., it is maintained up to about 73% at room temperature (25 ° C.). This result is at a level that does not hinder the practical use of the phosphor.
 (実施例2の蛍光体の粒子)
 図10は、実施例2の蛍光体(Eu濃度及びSi濃度が共に2.5mol%のとき)の粒子を示すSEM画像である。図10に示すように、合成された蛍光体は粒子状を成し、各粒子のサイズは5μm~10μmである。従って、実施例2の蛍光体も、実施例1と同様にLED用蛍光体に適した粒子状態を成すことも判明した。
(Phosphor particles of Example 2)
FIG. 10 is an SEM image showing particles of the phosphor of Example 2 (when both the Eu concentration and the Si concentration are 2.5 mol%). As shown in FIG. 10, the synthesized phosphor is in the form of particles, and the size of each particle is 5 μm to 10 μm. Therefore, it was also found that the phosphor of Example 2 has a particle state suitable for the LED phosphor as in Example 1.
 (実施例3の蛍光体)
 第3実施例として、Ce(セリウム)を含んだ発光イオンによって賦活されたNaMgPOを含み、発光イオンの賦活濃度が1~5mol%であり、かつ、NaMgPOの結晶構造がオリビン関連構造である蛍光体を以下のように作製した。
(Phosphor of Example 3)
As a third example, NaMgPO 4 activated by a luminescent ion containing Ce (cerium) is included, the activation concentration of the luminescent ion is 1 to 5 mol%, and the crystal structure of NaMgPO 4 is an olivine-related structure. A phosphor was prepared as follows.
 (実施例3の蛍光体の製造方法)
 出発原料にNaCO(株式会社豊島製作所製)、MgO(関東化学株式会社製)、NHPO(関東化学株式会社製)、CeO(関東化学株式会社製)を用いた。これら原料を用いて、実施例1の場合と同様に湿式混合、仮焼成、及びアークイメージング炉での焼成を行った。なお、CeOを添加する分量を適宜調節し、Ce濃度の異なる蛍光体を合成した。
(Method for Producing Phosphor of Example 3)
Na 2 CO 3 (manufactured by Toshima Seisakusho), MgO (manufactured by Kanto Chemical Co., Ltd.), NH 4 H 2 PO 4 (manufactured by Kanto Chemical Co., Ltd.), and CeO 2 (manufactured by Kanto Chemical Co., Ltd.) were used as starting materials. . Using these raw materials, wet mixing, temporary firing, and firing in an arc imaging furnace were performed in the same manner as in Example 1. Note that phosphors having different Ce concentrations were synthesized by appropriately adjusting the amount of CeO 2 added.
 (実施例3の蛍光体のXRDパターン)
 図11は、実施例3の粉末X線回折パターンを示す。Ce濃度が1mol%、3mol%、5mol%のいずれの条件でも、ほぼ同様の位置でピークを有すること、及び、Ceの濃度が1mol%又は3mol%のときに回折パターンが強く明白になることが確認された。これにより、実施例3のいずれの濃度条件でも、同様の結晶構造(オリビン関連構造)が得られており、Ce濃度が1mol%又は3mol%のときに上記構造として最適な状態となっていることが推察される。
(XRD pattern of the phosphor of Example 3)
FIG. 11 shows the powder X-ray diffraction pattern of Example 3. Under any condition of Ce concentration of 1 mol%, 3 mol%, and 5 mol%, it has a peak at almost the same position, and the diffraction pattern is strongly evident when the concentration of Ce is 1 mol% or 3 mol%. confirmed. As a result, the same crystal structure (olivine-related structure) is obtained under any concentration conditions of Example 3, and the structure is in an optimal state when the Ce concentration is 1 mol% or 3 mol%. Is inferred.
 (実施例3の蛍光体の蛍光特性)
 図12は、実施例3の蛍光体の蛍光特性を示した図である。この図12の結果より、実施例3の蛍光体は、紫外域で励起し、紫色の発光を示すことが確認された。なお、最も高い発光強度を示したのはCe濃度が3mol%のときであった。なお、図13は、グラセライト型構造を有した従来のNaMgPO:Ce3+の蛍光特性を示す(非特許文献5)。この図13中の励起スペクトル及び発光スペクトルは共に、図12に示す実施例3の各スペクトルとは全く異なったものであることが確認された。
(Fluorescence characteristics of the phosphor of Example 3)
FIG. 12 is a diagram showing the fluorescence characteristics of the phosphor of Example 3. From the results shown in FIG. 12, it was confirmed that the phosphor of Example 3 was excited in the ultraviolet region and showed purple emission. The highest emission intensity was exhibited when the Ce concentration was 3 mol%. Incidentally, FIG. 13, the conventional NaMgPO had Gurase write structure 4: shows the fluorescence properties of Ce 3+ (Non-Patent Document 5). It was confirmed that both the excitation spectrum and the emission spectrum in FIG. 13 were completely different from the spectra of Example 3 shown in FIG.
 (実施例4の蛍光体)
 第4実施例として、Ce及びTb(テルビウム)を含んだ発光イオンによって賦活されたNaMgPOを含み、前記発光イオンの各賦活濃度は1~5mol%であり、かつ、前記NaMgPOの結晶構造がオリビン関連構造である蛍光体を以下のように作製した。
(Phosphor of Example 4)
Example 4 includes NaMgPO 4 activated by luminescent ions containing Ce and Tb (terbium), each activating ion concentration is 1 to 5 mol%, and the crystal structure of NaMgPO 4 is A phosphor having an olivine-related structure was prepared as follows.
 (実施例4の蛍光体の製造方法)
 実施例4では、実施例3で使用した出発原料の他に、Tb(関東化学株式会社製)を用いた。これらの原料を用いて、実施例1の場合と同様に湿式混合、仮焼成、及びアークイメージング炉での焼成を行った。なお、CeO及びTbを添加する分量を適宜調節し、Ce濃度及びTb濃度の異なる蛍光体を合成した。
(Method for Producing Phosphor of Example 4)
In Example 4, in addition to the starting material used in Example 3, Tb 4 O 7 (manufactured by Kanto Chemical Co., Inc.) was used. Using these raw materials, wet mixing, temporary firing, and firing in an arc imaging furnace were performed in the same manner as in Example 1. Incidentally, appropriately adjusting the amount of addition of CeO 2 and Tb 4 O 7, was synthesized different phosphors Ce concentration and Tb concentration.
 (実施例4の蛍光体のXRDパターン)
 図14は、実施例4の粉末X線回折パターンを示す。(Ce,Tb)の濃度が(3mol%,1mol%)、(3mol%,3mol%)、(3mol%,5mol%)のいずれの条件でも、ほぼ同様の位置でピークを有することが確認された。これにより、実施例4のいずれの濃度条件でも、同様の結晶構造(オリビン関連構造)が得られていることが推察される。
(XRD pattern of the phosphor of Example 4)
FIG. 14 shows the powder X-ray diffraction pattern of Example 4. It was confirmed that the concentration of (Ce, Tb) had a peak at almost the same position under any of the conditions (3 mol%, 1 mol%), (3 mol%, 3 mol%), and (3 mol%, 5 mol%). . Thereby, it is inferred that the same crystal structure (olivine-related structure) is obtained under any concentration conditions of Example 4.
 (実施例4の蛍光体の蛍光特性)
 図15は、実施例4の蛍光体の蛍光特性を示した図である。この図15より、実施例4の蛍光体は、紫外域で励起し、緑色の発光(545nm近くにピークを持った発光スペクトル)を示すことが確認された。なお、最も高い発光強度を示したのはTb濃度が3mol%のときであった。
(Fluorescence characteristics of the phosphor of Example 4)
FIG. 15 is a diagram showing the fluorescence characteristics of the phosphor of Example 4. From this FIG. 15, it was confirmed that the phosphor of Example 4 was excited in the ultraviolet region and showed green emission (emission spectrum having a peak near 545 nm). The highest emission intensity was shown when the Tb concentration was 3 mol%.
 (実施例5の蛍光体)
 第5実施例として、Euを含んだ発光イオンによって賦活されたNaMgPOを含み、Eu濃度が2.5mol%であり、Na又はMgの一部が、5mol%の濃度を有したK(カリウム)又はSr(ストロンチウム)で置換された蛍光体を以下のように作製した。
(Phosphor of Example 5)
As a fifth embodiment, K (potassium) containing NaMgPO 4 activated by luminescent ions containing Eu, having a Eu concentration of 2.5 mol%, and a part of Na or Mg having a concentration of 5 mol%. Or the fluorescent substance substituted by Sr (strontium) was produced as follows.
 (実施例5の蛍光体の製造方法)
 実施例5では、実施例1で使用した出発原料の他に、KCO(関東化学株式会社製)又はSrCO(関東化学株式会社製)を用いた。これらの原料を用いて、実施例1の場合と同様に湿式混合、仮焼成、及びアークイメージング炉での焼成を行った。
(Method for Producing Phosphor of Example 5)
In Example 5, in addition to the starting material used in Example 1, K 2 CO 3 (manufactured by Kanto Chemical Co., Inc.) or SrCO 3 (manufactured by Kanto Chemical Co., Ltd.) was used. Using these raw materials, wet mixing, temporary firing, and firing in an arc imaging furnace were performed in the same manner as in Example 1.
 (実施例5の蛍光体のXRDパターン)
 図16は、実施例5の粉末X線回折パターンを示す。図中のK又はSrのいずれの条件でも、ほぼ同様の位置でピークを有することが確認された。これにより、実施例1~実施例4のNaMgPOを構成するNa又はMgの一部を、KやSrのような、アルカリ金属元素又はアルカリ土類金属元素で置換した場合でも、同様の結晶構造(オリビン関連構造)が得られていることが推察される。
(XRD pattern of the phosphor of Example 5)
FIG. 16 shows the powder X-ray diffraction pattern of Example 5. It was confirmed that there was a peak at substantially the same position under any condition of K or Sr in the figure. Thus, even when a part of Na or Mg constituting NaMgPO 4 of Examples 1 to 4 is replaced with an alkali metal element or alkaline earth metal element such as K or Sr, the same crystal structure is obtained. It is inferred that (olivine-related structure) is obtained.
 (実施例5の蛍光体の蛍光特性)
 図17は、実施例5の蛍光体の蛍光特性を示した図である。図17から、実施例5の蛍光体は、紫外から青色の領域(300nm~460nm)の光強度を主に有する光で励起し、赤色の発光(具体的には、620nm近くにピークを持った発光スペクトル)を示す。つまり、実施例1と類似の蛍光特性を示すことが観察された。
(Fluorescence characteristics of the phosphor of Example 5)
FIG. 17 is a diagram showing the fluorescence characteristics of the phosphor of Example 5. From FIG. 17, the phosphor of Example 5 was excited by light mainly having light intensity in the ultraviolet to blue region (300 nm to 460 nm), and had red light emission (specifically, a peak near 620 nm). Emission spectrum). That is, it was observed that the fluorescence characteristics similar to Example 1 were exhibited.
 本発明により製造されたリン酸塩蛍光体は、既存の白色LED用赤色蛍光体の安価な代替材料として期待できる。また、本発明によれば、賦活させる発光イオンの選択やSiを添加することによって、発光色を自在に変化させることが可能になる。従って、本発明は、産業上の利用価値及び利用可能性が非常に高い。 The phosphate phosphor produced according to the present invention can be expected as an inexpensive alternative to the existing red phosphor for white LEDs. Further, according to the present invention, the emission color can be freely changed by selecting the luminescent ions to be activated or adding Si. Therefore, the present invention has very high industrial utility value and applicability.

Claims (6)

  1.  Euを含んだ発光イオンによって賦活されたNaMgPOを含み、前記発光イオンの賦活濃度は1~10mol%であり、前記NaMgPOの結晶構造がオリビン関連構造であり、かつ、橙色~赤色に発光することを特徴とするリン酸塩蛍光体。 It contains NaMgPO 4 activated by luminescent ions including Eu, the activation concentration of the luminescent ions is 1 to 10 mol%, the crystal structure of the NaMgPO 4 is an olivine-related structure, and emits light in orange to red A phosphate phosphor characterized by that.
  2.  Pの一部がSi及びAlからなる群の少なくとも一種の元素で置換されていることを特徴とする請求項1に記載のリン酸塩蛍光体。 The phosphate phosphor according to claim 1, wherein a part of P is substituted with at least one element of the group consisting of Si and Al.
  3.  Ceを含んだ発光イオンによって賦活されたNaMgPOを含み、前記発光イオンの賦活濃度は1~5mol%であり、かつ、前記NaMgPOの結晶構造がオリビン関連構造であることを特徴とするリン酸塩蛍光体。 It includes NaMgPO 4 which is activated by emitting ions containing Ce, activation concentration of the luminescent ions is 1 ~ 5 mol%, and phosphoric acid, wherein the crystal structure of the NaMgPO 4 is olivine related structures Salt phosphor.
  4.  Ce及びTbを含んだ発光イオンによって賦活されたNaMgPOを含み、前記発光イオンの各賦活濃度は1~5mol%であり、かつ、前記NaMgPOの結晶構造がオリビン関連構造であることを特徴とするリン酸塩蛍光体。 It contains NaMgPO 4 activated by luminescent ions including Ce and Tb, each activating ion concentration is 1 to 5 mol%, and the crystal structure of NaMgPO 4 is an olivine-related structure. Phosphate phosphor.
  5.  Na又はMgの一部が、K、Li、Ca、及びSrからなる群の少なくとも一種の元素で置換されていることを特徴とする請求項1~4のいずれかに記載のリン酸塩蛍光体。 The phosphate phosphor according to claim 1, wherein a part of Na or Mg is substituted with at least one element of the group consisting of K, Li, Ca, and Sr. .
  6.  請求項1~5のいずれかに記載のリン酸塩蛍光体の製造方法であって、
     前記リン酸塩蛍光体が含有する元素を含んだ化合物を原料として混合する混合工程と、
     混合物を空気中又は還元雰囲気下で焼成する焼成工程と、
     を含み、かつ、
     前記焼成工程では、前記混合物を溶融させた後に、冷却することを特徴とする製造方法。
    A method for producing a phosphate phosphor according to any one of claims 1 to 5,
    A mixing step of mixing a compound containing an element contained in the phosphate phosphor as a raw material;
    A firing step of firing the mixture in air or in a reducing atmosphere;
    Including, and
    In the firing step, the mixture is melted and then cooled.
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CN115322780A (en) * 2022-08-26 2022-11-11 兰州大学 Red fluorescent powder and preparation method and application thereof

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JP2018080215A (en) * 2016-11-14 2018-05-24 太平洋セメント株式会社 Manufacturing method of phosphate fluophor
CN114231283A (en) * 2022-01-24 2022-03-25 西安建筑科技大学 Phosphate blue fluorescent powder excited by near ultraviolet light, preparation method thereof and white light LED light-emitting device
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