JP2013194078A - Phosphor, method for producing the same, light-emitting device and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phosphor that has a high emission intensity and is chemically and thermally stable when combined with an LED having ≤470 nm.SOLUTION: A phosphor comprises an inorganic compound which contains elements of A, D, E and X (A is at least one element selected from Mg, Ca, Sr and Ba, D is at least one element selected from Si, Ge, Sn, Ti, Zr and Hf, E is at least one element selected from Al, Ga, In, Sc, Y and La an X is at least one element selected from O, N and F) and in which M (M is at least one element of Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Yb) forms a solid solution in any crystal of an N crystal containing a structure of AB(D, E)X, a structure of A(D, E)Xor a structure of (1-x)AB(D, E)X+xA(D, E)X(0≤x≤1), an inorganic crystal having the same crystal structure as the N crystal and a solid solution crystal of these crystals.

Description

In the present invention, (1-x) A ₂ B ₂ (D, E) ₄ X ₈ + xA ₂ (D, E) ₆ X ₉ (where x is a numerical value of 0 or more and 1 or less, and A is Mg, One or more elements selected from Ca, Sr, Ba, D is one or more elements selected from Si, Ge, Sn, Ti, Zr, Hf, E is Al, Ga, One or two or more elements selected from In, Sc, Y, and La, and X is one or more elements selected from O, N, and F) (hereinafter referred to as N crystal) Or an inorganic crystal having the same crystal structure as the N crystal, or a solid solution crystal of these crystals, M element (where M is selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Yb) Phosphors made of inorganic compounds in which one or more elements are dissolved and their production Methods, and uses thereof.

  The phosphor is a fluorescent display tube (VFD (Vacuum-Fluorescent Display)), a field emission display (FED (Field Emission Display)), or a SED (Surface-Condition Electron display-Pl (Panel Display) (P panel). ), Cathode ray tube (CRT (Cathode-Ray Tube)), liquid crystal display backlight (Liquid-Crystal Display Backlight), white light emitting diode (LED (Light-Emitting Diode)), and the like. In any of these applications, in order to make the phosphor emit light, it is necessary to supply the phosphor with energy for exciting the phosphor, and the phosphor is not limited to vacuum ultraviolet rays, ultraviolet rays, electron beams, blue light, etc. When excited by an excitation source having high energy, visible light such as blue light, green light, yellow light, orange light, and red light is emitted. However, as a result of exposure of the phosphor to the excitation source as described above, there is a demand for a phosphor that is liable to lower the luminance of the phosphor and has no luminance reduction. Therefore, instead of conventional phosphors such as silicate phosphors, phosphate phosphors, aluminate phosphors and sulfide phosphors, sialon phosphors can be used as phosphors with little reduction in luminance even when excited with high energy. There have been proposed phosphors based on inorganic crystals containing nitrogen in the crystal structure, such as oxynitride phosphors and nitride phosphors.

An example of this sialon phosphor is manufactured by a manufacturing process generally described below. First, silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), and europium oxide (Eu ₂ O ₃ ) are mixed at a predetermined molar ratio, and the temperature is 1700 ° C. in nitrogen at 1 atm (0.1 MPa). It is manufactured by holding for 1 hour and firing by a hot press method (see, for example, Patent Document 1). It has been reported that α sialon activated by Eu ²⁺ ions obtained by this process becomes a phosphor that emits yellow light of 550 to 600 nm when excited by blue light of 450 to 500 nm. Further, it is known that the emission wavelength changes by changing the ratio of Si and Al and the ratio of oxygen and nitrogen while maintaining the crystal structure of α sialon (see, for example, Patent Document 2 and Patent Document 3). ).

As another example of the sialon phosphor, a green phosphor obtained by activating Eu ²⁺ to a β-type sialon is known (see Patent Document 4). In this phosphor, it is known that the emission wavelength changes to a short wavelength by changing the oxygen content while maintaining the crystal structure (see, for example, Patent Document 5). Further, it is known that when Ce ³⁺ is activated, a blue phosphor is obtained (for example, see Patent Document 6).

An example of an oxynitride phosphor, JEM phase _{(LaAl (Si 6-z Al} z) N 10-z O z) blue phosphor were activated with Ce as host crystals (see Patent Document 7) are known ing. In this phosphor, it is known that by exchanging a part of La with Ca while maintaining the crystal structure, the excitation wavelength becomes longer and the emission wavelength becomes longer.

As another example of the oxynitride phosphor, a blue phosphor in which Ce is activated using a La—N crystal La ₃ Si ₈ N ₁₁ O ₄ as a base crystal (see Patent Document 8) is known.

As an example of a nitride phosphor, a red phosphor in which Eu ²⁺ is activated using CaAlSiN ₃ as a base crystal (see Patent Document 9) is known. By using this phosphor, there is an effect of improving the color rendering properties of the white LED. A phosphor added with Ce as an optically active element has been reported as an orange phosphor.

  As described above, the emission color of the phosphor is determined by a combination of a crystal serving as a base and a metal ion (activated ion) to be dissolved therein. Furthermore, the combination of the base crystal and the activated ion determines the emission characteristics such as emission spectrum and excitation spectrum, chemical stability, and thermal stability, so when the base crystal is different or the activated ion is different, Considered as a different phosphor. In addition, even if the chemical composition is the same, materials having different crystal structures are regarded as different phosphors because their emission characteristics and stability differ due to different host crystals.

Furthermore, in many phosphors, it is possible to replace the type of constituent elements while maintaining the crystal structure of the host crystal, thereby changing the emission color. For example, a phosphor obtained by adding Ce to YAG emits green light, but a phosphor obtained by substituting a part of Y in the YAG crystal with Gd and a part of Al with Ga exhibits yellow light emission. Furthermore, it is known that in a phosphor obtained by adding Eu to CaAlSiN ₃ , the composition changes while maintaining a crystal structure by substituting part of Ca with Sr, and the emission wavelength is shortened. In this way, the phosphors that have undergone element substitution while maintaining the crystal structure are regarded as the same group of materials.

  For these reasons, in the development of new phosphors, it is important to find a host crystal having a new crystal structure, and activate the metal ions responsible for light emission in such a host crystal to express fluorescence characteristics. Thus, a novel phosphor can be proposed.

Japanese Patent No. 3668770 Japanese Patent No. 3837551 Japanese Patent No. 4524368 Japanese Patent No. 3921545 International Publication No. 2007/066673 International Publication No. 2006/101096 International Publication No. 2005/019376 JP 2005-112922 A Japanese Patent No. 3837588

  The present invention is intended to meet such a demand, and one of the objects is an LED having emission characteristics (emission color, excitation characteristics, emission spectrum) different from those of conventional phosphors and having a wavelength of 470 nm or less. It is an object to provide an inorganic phosphor having high emission intensity even when combined with the above and chemically and thermally stable. Another object of the present invention is to provide a light emitting device with excellent durability and an image display device with excellent durability using such a phosphor.

  Under these circumstances, the present inventors have conducted detailed research on a new crystal containing nitrogen and a phosphor based on a crystal obtained by substituting a metal element or nitrogen in the crystal structure with another element. It has been found that inorganic phosphors based on crystals or crystals having the same crystal structure as N crystals emit high-luminance fluorescence. It was also found that a specific composition shows yellow to red light emission.

  Furthermore, by using this phosphor, it has been found that a white light emitting diode (light emitting device) having high luminous efficiency and small temperature fluctuation, a lighting apparatus using the same, and a vivid color image display device can be obtained. It was.

  As a result of intensive studies in view of the above circumstances, the present inventor has succeeded in providing a phosphor exhibiting a high luminance light emission phenomenon in a specific wavelength region by adopting the configuration described below. Moreover, it succeeded in manufacturing the fluorescent substance with the outstanding luminescent property using the following method. Furthermore, by using this phosphor, it has succeeded in providing a light emitting device, a lighting apparatus, an image display device, a pigment, and an ultraviolet absorber having excellent characteristics by adopting the configuration described below. The configuration is as described below.

(1) At least A element, D element, E element, and X element (where A is one or more elements selected from Mg, Ca, Sr, Ba, and D is Si, Ge, Sn, Ti) , Zr, Hf, one or more elements selected from E, E is one or more elements selected from Al, Ga, In, Sc, Y, La, X is O, N, F 1 type or 2 or more types of elements selected from), and if necessary, B element (boron)
(A) a structure represented by A ₂ B ₂ (D, E) ₄ X ₈ in the unit cell of the crystal, or
A structure represented by A ₂ (D, E) ₆ X ₉ or (1-x) A ₂ B ₂ (D, E) ₄ X ₈ + xA ₂ (D, E) ₆ X ₉ (where x is 0 A crystal including a structure represented by the above (numerical value of 1 or less) (hereinafter referred to as N crystal),
(B) an inorganic crystal having the same crystal structure as the N crystal,
(C) a solid solution crystal of these crystals,
From an inorganic compound in which M element (where M is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb) is dissolved in any of the crystals A phosphor.
(2) The N crystal has an average unit cell structure of
(1-x) A ₂ B ₂ (D, E) ₄ X ₈ + xA ₂ (D, E) ₆ X ₉
(However, x is a numerical value of 0 or more and 1 or less) The phosphor according to (1) above.
(3) The phosphor according to (1), wherein the A element contains Sr, the D element contains Si, the E element contains Al, and the X element contains N.
(4) The phosphor according to (1), wherein x is a numerical value in a range of 0.02 ≦ x ≦ 0.2.
(5) The phosphor according to (1), wherein the N crystal is Sr ₂ Si _2.30 Al _1.90 N _8.10 B _1.80 .
(6) The phosphor according to (1) above, wherein the N crystal or the inorganic crystal having the same crystal structure as the N crystal is a hexagonal crystal and has P62c symmetry.
(7) N crystal or an inorganic crystal having the same crystal structure as N crystal is a hexagonal crystal,
Lattice constants a, b, c are
a = 0.47965 ± 0.05 nm
b = 0.47965 ± 0.05 nm
c = 0.97932 ± 0.05 nm
The phosphor according to (1), which has a value in the range of
(8) the inorganic compound, formula _{B c M d A e D f} E g X h ( proviso that wherein c + d + e + f + g + h = 1, M is, Mn, Ce, Pr, Nd , Sm, Eu, Tb, One or more elements selected from Dy and Yb, A is one or more elements selected from Mg, Ca, Sr and Ba, D is Si, Ge, Sn, Ti, Zr, One or more elements selected from Hf, E is one or more elements selected from Al, Ga, In, Sc, Y, and La, and X is selected from O, N, and F One or more elements) and the parameters c, d, e, f, g, h are
0.1 ≦ c ≦ 0.25
0.00001 ≦ d ≦ 0.05
0.08 ≦ e ≦ 0.16
0.08 ≦ f ≦ 0.2
0 ≤ g ≤ 0.2
0.45 ≤ h ≤ 0.55
The phosphor according to (1), which is represented by a composition in a range that satisfies all of the above conditions.
(9) The phosphor according to (1), wherein the inorganic compound is a single crystal particle or an aggregate of single crystals having an average particle size of 0.1 μm or more and 20 μm or less.
(10) The phosphor according to (1), which is composed of a mixture of the phosphor composed of the inorganic compound according to (1) and another crystal phase or an amorphous phase, and the phosphor content is 20% by mass or more. Phosphor.
(11) The phosphor according to (10), wherein the other crystalline phase or amorphous phase is an inorganic substance having conductivity.
(12) The phosphor according to (1), wherein Eu is included in the M element and emits fluorescence having a peak in a wavelength range of 550 nm to 650 nm by irradiating an excitation source.
(13) The phosphor according to (12), wherein the excitation source is vacuum ultraviolet light, ultraviolet light, visible light, electron beam, or X-ray having a wavelength of 100 nm to 520 nm.
(14) A mixture of metal compounds, which is baked to produce a raw material mixture capable of constituting the phosphor according to claim 1 in a temperature range of 1200 ° C. to 2200 ° C. in an inert atmosphere containing nitrogen. The method for producing a phosphor according to (1), wherein the phosphor is fired.
(15) The mixture of metal compounds is a compound containing B, a compound containing M, a compound containing A, a compound containing D, a compound containing E, and a compound containing X (However, M is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb, and A is one selected from Mg, Ca, Sr, and Ba. Or two or more elements, D is one or more elements selected from Si, Ge, Sn, Ti, Zr, and Hf, and E is selected from Al, Ga, In, Sc, Y, and La. The method for producing a phosphor according to the above (14), comprising one or two or more elements, wherein X is one or two or more elements selected from O, N, and F).
(16) The compound containing M is a simple substance or two kinds selected from metals, silicides, oxides, carbonates, nitrides, oxynitrides, chlorides, fluorides, or oxyfluorides containing M The above-mentioned mixture, wherein the compound containing A is a simple substance selected from metals, silicides, oxides, carbonates, nitrides, oxynitrides, chlorides, fluorides, or oxyfluorides containing A Or a mixture of two or more kinds, wherein the compound containing D is a simple substance selected from metals, silicides, oxides, carbonates, nitrides, oxynitrides, chlorides, fluorides, or oxyfluorides, or The method for producing a phosphor according to (15), which is a mixture of two or more kinds.
(17) A light emitting device comprising at least a light emitter and a phosphor, wherein the phosphor according to (1) is used at least.
(18) The light emitting device according to (17), wherein the light emitter is a light emitting diode (LED), a laser diode (LD), a semiconductor laser, or an organic EL light emitter (OLED) that emits light having a wavelength of 330 to 500 nm. .
(19) The light emitting device according to (17), wherein the light emitting device is a white light emitting diode, a lighting fixture including a plurality of white light emitting diodes, or a backlight for a liquid crystal panel.
(20) The phosphor emits ultraviolet or visible light having a peak wavelength of 300 to 500 nm, and mixes yellow to red light emitted from the phosphor according to claim 1 and light having a wavelength of 450 nm or more emitted from another phosphor. The light-emitting device according to (17), which emits white light or light other than white light.
(21) The light emitting device according to (17), wherein the phosphor further includes a blue phosphor that emits light having a peak wavelength of 420 nm to 500 nm or less by the light emitter.
(22) The blue phosphor is AlN: (Eu, Si), BaMgAl ₁₀ O ₁₇ : Eu, SrSi ₉ Al ₁₉ ON ₃₁ : Eu, LaSi ₉ Al ₁₉ N ₃₂ : Eu, α-sialon: Ce, JEM: The light emitting device according to (21), selected from Ce.
(23) The light emitting device according to (17), wherein the phosphor further includes a green phosphor that emits light having a peak wavelength of 500 nm or more and 550 nm or less by the light emitter.
(24) The green phosphor is selected from β-sialon: Eu, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu 23).
(25) The light emitting device according to (17), wherein the phosphor further includes a yellow phosphor that emits light having a peak wavelength of 550 nm or more and 600 nm or less by the light emitter.
(26) The light emitting device according to (25), wherein the yellow phosphor is selected from YAG: Ce, α-sialon: Eu, CaAlSiN ₃ : Ce, and La ₃ Si ₆ N ₁₁ : Ce.
(27) The light emitting device according to (17), wherein the phosphor further includes a red phosphor that emits light having a peak wavelength of 600 nm to 700 nm by the light emitter.
(28) In the above (27), the red phosphor is selected from CaAlSiN ₃ : Eu, (Ca, Sr) AlSiN ₃ : Eu, Ca ₂ Si ₅ N ₈ : Eu, and Sr ₂ Si ₅ N ₈ : Eu. Light-emitting device.
(29) The light emitting device according to (42), wherein the light emitter is an LED that emits light having a wavelength of 320 to 500 nm.
(30) An image display device comprising an excitation source and a phosphor, wherein at least the phosphor described in (1) is used.
(31) The image display device is any one of a fluorescent display tube (VFD), a field emission display (FED), a plasma display panel (PDP), a cathode ray tube (CRT), and a liquid crystal display (LCD). The image display device described in 1.
(32) A pigment comprising the inorganic compound according to (1).
(33) An ultraviolet absorber comprising the inorganic compound according to (1).

  The phosphor of the present invention includes a multi-element nitride containing a divalent element, a trivalent element, and a tetravalent element, or a multi-element oxynitride, particularly an N crystal and other crystals having the same crystal structure as the N crystal. Is contained as a main component, it emits light with higher luminance than conventional oxide phosphors and oxynitride phosphors, and is excellent as a yellow to red phosphor in a specific composition. Even when exposed to an excitation source, this phosphor does not decrease in luminance, so it is suitably used for light emitting devices such as white light emitting diodes, lighting fixtures, backlight sources for liquid crystals, VFD, FED, PDP, CRT, etc. The present invention provides a useful phosphor. Moreover, since this fluorescent substance absorbs an ultraviolet-ray, it is suitable for a pigment and a ultraviolet absorber.

The figure which shows the crystal structure of N crystal | crystallization. The figure which shows the powder X-ray diffraction using the CuK alpha ray computed from the crystal structure of N crystal | crystallization. Schematic which shows the lighting fixture (bullet type LED lighting fixture) by this invention. Schematic which shows the lighting fixture (board-mounting type LED lighting fixture) by this invention. Schematic which shows the image display apparatus (plasma display panel) by this invention. Schematic which shows the image display apparatus (field emission display panel) by this invention.

Hereinafter, the phosphor of the present invention will be described in detail with reference to the drawings.
The phosphor of the present invention includes at least an A element, a D element, an E element, and an X element (where A is one or more elements selected from Mg, Ca, Sr, and Ba, and D is Si, Ge. One or more elements selected from Sn, Ti, Zr, and Hf, E is one or more elements selected from Al, Ga, In, Sc, Y, and La, and X is O , One or more elements selected from N and F), and optionally B element (boron),
(1) A structure represented by A ₂ B ₂ (D, E) ₄ X ₈ in the unit cell of the crystal, or
A structure represented by A ₂ (D, E) ₆ X ₉ or (1-x) A ₂ B ₂ (D, E) ₄ X ₈ + xA ₂ (D, E) ₆ X ₉ (where x is 0) A crystal including a structure represented by the above (numerical value of 1 or less) (hereinafter referred to as N crystal),
(2) an inorganic crystal having the same crystal structure as the N crystal,
(3) solid solution crystals of these crystals,
From an inorganic compound in which M element (where M is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb) is dissolved in any of the crystals Become.

The N crystal, which is a crystal represented by (1-x) A ₂ B ₂ (D, E) ₄ X ₈ + xA ₂ (D, E) ₆ X ₉ , was newly synthesized by the present inventor and analyzed by crystal structure analysis. It is a crystal that has been confirmed as a new crystal and has not been reported before the present invention.

  FIG. 1 is a diagram showing a crystal structure of an N crystal.

Sr ₂ Si ₂₃₀ Al _1.90 N _8.10 B _1.80 synthesized by the present inventor is one of the N crystals, and the single Sr ₂ Si ₂₃₀ Al _1.90 N _8.10 B _1.80 was obtained. According to the crystal structure analysis, this crystal belongs to the hexagonal system, belongs to the P62c space group (International Tables for Crystallography No. 190 space group), and occupies the crystal parameters and atomic coordinate positions shown in Table 1.
In Table 1, lattice constants a, b, and c indicate the lengths of the unit cell axes, and α, β, and γ indicate the angles between the unit cell axes. The atomic coordinates indicate the position of each atom in the unit cell as a value between 0 and 1 with the unit cell as a unit. In this crystal, each atom of Sr, Si, Al, O, N, and B was present, and Sr was obtained in one kind of seat (Sr (1)). In addition, Si and Al were obtained in two types of seats (Si, Al (1) and Si, Al (2)). Moreover, O and N obtained the analysis result which exists in three types of the same seats (O, N (1) to O, N (3)). Furthermore, B obtained an analysis result existing in one type of the same seat (B (1)).

As a result of the analysis using the data in Table 1, the Sr ₂ Si ₂₃₀ Al _1.90 N _8.10 B _1.80 crystal has the structure shown in FIG. 1 and is composed of a combination of Si or Al and O or N. It was found that the structure has a structure in which a Sr element is contained in a skeleton in which tetrahedrons are connected. In this crystal, the M element that becomes an activating ion such as Eu is incorporated into the crystal in a form that replaces a part of the Sr element.

As a crystal having the same crystal structure as the synthesized and structurally analyzed Sr ₂ Si ₂₃₀ Al _1.90 N _8.10 B _1.80 crystal,
(1-x) A ₂ B ₂ (D, E) ₄ X ₈ + xA ₂ (D, E) ₆ X ₉
There is a crystal represented by (where x is a numerical value of 0 or more and 1 or less). This crystal has a structure in which the unit lattice of the crystal is represented by A ₂ B ₂ (D, E) ₄ X ₈ or a structure represented by A ₂ (D, E) ₆ X ₉ , and the value of x Changes the mixing ratio of the structure represented by A ₂ B ₂ (D, E) ₄ X ₈ and the structure represented by A ₂ (D, E) ₆ X ₉ . Thus, as an average value in the entire _{crystal, (1-x) A 2} B 2 (D, E) 4 X 8 + xA 2 (D, E) 6 X 9
The composition is taken.

The N crystal of the present invention can be identified by X-ray diffraction or neutron diffraction. As a substance showing the same diffraction as the X-ray diffraction result of the Sr ₂ Si ₂₃₀ Al _1.90 N _8.10 B _1.80 crystal shown in the present invention, (1-x) A ₂ B ₂ (D, E) ₄ There is a crystal represented by X ₈ + xA ₂ (D, E) ₆ X ₉ . Furthermore, there is a crystal whose lattice constant or atomic position is changed by replacing a constituent element in the N crystal with another element.

  The lattice constant of the N crystal varies depending on the selection of its constituent element components and the activation element such as Eu, but the atomic position given by the crystal structure, the site occupied by the atom, and its coordinates is between the skeletal atoms. It does not change so much that the chemical bond of is broken. In the present invention, Al-N, Al-O, Si-N, Si-O calculated from lattice constants and atomic coordinates obtained by Rietveld analysis of the X-ray diffraction and neutron diffraction results in the P62c space group. If the chemical bond length (distance between adjacent atoms) is within ± 5% of the chemical bond length calculated from the crystal lattice constants and atomic coordinates shown in Table 1, it is defined as the same crystal structure. To determine whether it is an N crystal. This criterion is because, according to experiments, it has been confirmed that when the length of the chemical bond in the N crystal changes beyond ± 5%, the chemical bond is broken and another crystal is formed.

  Furthermore, when the amount of solid solution is small, there is the following method as a simple determination method of N-based crystals. When the lattice constant calculated from the X-ray diffraction results measured for a new substance and the diffraction peak position (2θ) calculated using the crystal structure data shown in Table 1 match for the main peak, the crystal structure is identified as the same. can do.

FIG. 2 is a diagram showing powder X-ray diffraction using CuKα rays calculated from the crystal structure of Sr ₂ Si ₂₃₀ Al _1.90 N _8.10 B _1.80 crystal. In the actual synthesis, a synthetic product in a powder form is obtained. Therefore, by comparing the obtained synthetic product with the spectrum shown in FIG. 2, it is possible to determine whether or not a synthetic product of N crystals has been obtained.

  By comparing the substance to be compared with FIG. 2, it is possible to easily determine whether or not the substance is an N crystal. As the main peak of the N crystal, it is preferable to determine about 10 with strong diffraction intensity. Table 1 is important because it serves as a reference in specifying the N crystal in that sense. In addition, an approximate structure can be defined by using another hexagonal crystal system for the crystal structure of the N crystal, and in that case, it is expressed using different space groups, lattice constants, and plane indices. There is no change in the X-ray diffraction result (for example, FIG. 2) and the crystal structure (for example, FIG. 1), and the identification method and identification result using the result are the same. For this reason, in the present invention, X-ray diffraction analysis is performed as a hexagonal system. The substance identification method based on Table 1 will be specifically described in the examples described later, and is only a brief description here.

  A phosphor is obtained by activating one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb as an M element in an N crystal. It is done. Since the emission characteristics such as the excitation wavelength, emission wavelength, and emission intensity vary depending on the composition of the N crystal and the type and amount of the activation element, it may be selected according to the application. Those in which the M element is Eu have particularly high emission intensity.

In the N crystal, the average structure of the unit cell is
(1-x) A ₂ B ₂ (D, E) ₄ X ₈ + xA ₂ (D, E) ₆ X ₉
A crystal represented by (where x is a numerical value of 0 or more and 1 or less) has high emission intensity. In particular, a phosphor having a particularly high luminance is a phosphor having, as a base, a crystal containing Sr in the A element, Si in the D element, Al in the E element, and N in the X element.

x is a value indicating the ratio of the crystal structures of A ₂ B ₂ (D, E) ₄ X ₈ and A ₂ (D, E) ₆ X ₉ included, and a range of 0.02 ≦ x ≦ 0.2 However, the crystal structure is particularly stable and the emission intensity of the phosphor is high.

A crystal in which the N crystal is Sr ₂ Si ₂₃₀ Al _1.90 N _8.10 B _1.80 , ie
Sr ₂ Si ₂₃₀ Al _1.90 N _8.10 B _1.80 crystal, or crystal having the same crystal structure as Sr ₂ Si ₂₃₀ Al _1.90 N _8.10 B _1.80 crystal, or Sr ₂ The solid solution of Si ₂₃₀ Al _1.90 N _8.10 B _1.80 crystal has particularly high emission intensity.

  A crystal in which an N crystal or an inorganic crystal having the same crystal structure as the N crystal is a hexagonal crystal is particularly stable, and a phosphor using these as a host crystal has high emission intensity. Furthermore, crystals having symmetry of P62c are particularly stable, and phosphors using these as host crystals have high emission intensity.

Further, the N crystal or the inorganic crystal having the same crystal structure as the N crystal is a hexagonal crystal,
Lattice constants a, b, c are
a = 0.47965 ± 0.05 nm
b = 0.47965 ± 0.05 nm
c = 0.97932 ± 0.05 nm
Crystals having values in the range are particularly stable, and phosphors using these as host crystals have high emission intensity. Outside this range, the crystal becomes unstable and the light emission intensity may decrease.

Composition formula B _c M _d A _e D _f E _g X _h (where c + d + e + f + g + h = 1, where M is one selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Yb) Or two or more elements, A is one or more elements selected from Mg, Ca, Sr, and Ba, and D is one or two elements selected from Si, Ge, Sn, Ti, Zr, and Hf More than one element, E is one or more elements selected from Al, Ga, In, Sc, Y and La, and X is one or more elements selected from O, N and F ) And parameters c, d, e, f, g, h are
0.1 ≦ c ≦ 0.25
0.00001 ≦ d ≦ 0.05
0.08 ≦ e ≦ 0.16
0.08 ≦ f ≦ 0.2
0 ≤ g ≤ 0.2
0.45 ≤ h ≤ 0.55
A phosphor expressed by a composition in a range that satisfies all of the above conditions has particularly high emission intensity.

  The parameter c is the amount of element B added, and if it is less than 0.1 or more than 0.25, the crystal structure may become unstable and the light emission intensity may be lowered. The parameter d is the addition amount of the activating element, and if it is less than 0.00001, the amount of luminescent ions is insufficient and the luminance is lowered. If it exceeds 0.05, the emission intensity may decrease due to concentration quenching due to the interaction between luminescent ions. The parameter e is a parameter representing the composition of an alkaline earth element such as Sr, and if it is less than 0.08 or higher than 0.16, the crystal structure becomes unstable and the emission intensity decreases. The parameter f is a parameter representing the composition of the D element such as Si, and if it is less than 0.08 or higher than 0.2, the crystal structure becomes unstable and the emission intensity decreases. The parameter g is a parameter representing the composition of the E element such as Al, and if it is higher than 0.2, the crystal structure becomes unstable and the emission intensity decreases. The parameter h is a parameter representing the composition of the X element such as O, N, F, etc. If it is less than 0.45 or higher than 0.55, the crystal structure becomes unstable and the light emission intensity decreases. The X element is an anion, and the composition of the O, N, and F ratio is determined so that the cation of the B, A, M, D, and E elements and the neutral charge are maintained.

  A phosphor that is a single crystal particle or an aggregate of single crystals having an average particle diameter of 0.1 μm or more and 20 μm or less has high luminous efficiency and good operability when mounted on an LED. It is better to control.

  As one embodiment of the present invention, a phosphor composed of a mixture of a phosphor having an N crystal as a base and another crystal phase or an amorphous phase, wherein the content of the phosphor of the N crystal is 20% by mass or more. There is. This embodiment may be used when the target characteristics cannot be obtained with a single phosphor of N crystal or when a function such as conductivity is added. The content of the N crystal phosphor may be adjusted according to the intended characteristics, but if it is 20% by mass or less, the emission intensity may be lowered.

  When the phosphor is required to have conductivity such as for electron beam excitation, an inorganic substance having conductivity as another crystal phase or amorphous phase may be added.

  Examples of the inorganic substance having conductivity include an oxide, an oxynitride, a nitride, or a mixture thereof containing one or more elements selected from Zn, Al, Ga, In, and Sn. Examples thereof include zinc oxide, aluminum nitride, indium nitride, and tin oxide.

As one embodiment of the present invention, there is a phosphor having a peak at a wavelength in the range of 550 nm to 650 nm when irradiated with an excitation source. For example, a phosphor of N crystal activated with Eu or Sr ₂ Si ₂₃₀ Al _1.90 N _8.10 B _1.80 crystal has an emission peak in this range.

  As one embodiment of the present invention, there is a phosphor that emits light with vacuum ultraviolet light, ultraviolet light, visible light, electron beam, or X-ray whose excitation source has a wavelength of 100 nm to 520 nm. By using these excitation sources, light can be emitted efficiently.

  The method for producing the phosphor of the present invention is not particularly defined. For example, a raw material mixture that can form an N crystal phosphor by firing is a mixture of metal compounds. It can be obtained by firing in a temperature range of 1200 ° C. or higher and 2200 ° C. or lower in an active atmosphere. Although the main crystal of the present invention is a hexagonal crystal and belongs to the space group P62c, crystals having a different crystal system or space group may be mixed depending on the synthesis conditions such as the firing temperature. Since the change in characteristics is slight, it can be used as a high-luminance phosphor.

  As a starting material, for example, a mixture of metal compounds is a compound containing B, a compound containing M, a compound containing A, a compound containing D, a compound containing E, and X. Compound to be contained (where M is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Yb, A is selected from Mg, Ca, Sr, Ba) One or two or more elements, D is one or more elements selected from Si, Ge, Sn, Ti, Zr, and Hf, E is Al, Ga, In, Sc, Y, La It is preferable to use a raw material consisting of one or two or more elements selected from: X is one or two or more elements selected from O, N, and F).

  As a starting material, the compound containing M is a simple substance or two kinds selected from metals containing M, silicides, oxides, carbonates, nitrides, oxynitrides, chlorides, fluorides, or oxyfluorides The above-mentioned mixture, wherein the compound containing A is a simple substance selected from metals, silicides, oxides, carbonates, nitrides, oxynitrides, chlorides, fluorides, or oxyfluorides containing A Or a mixture of two or more kinds, wherein the compound containing D is a simple substance selected from metals, silicides, oxides, carbonates, nitrides, oxynitrides, chlorides, fluorides, or oxyfluorides, or A mixture of two or more types is preferable because the raw materials are easily available and excellent in stability.

  The furnace used for firing has a high firing temperature, and the firing atmosphere is an inert atmosphere containing nitrogen. Therefore, carbon is used as a material for the high-temperature part of the furnace in a metal resistance heating method or a graphite resistance heating method. A suitable electric furnace is preferred. The inert atmosphere containing nitrogen is preferably in the pressure range of 0.1 MPa or more and 100 MPa or less because thermal decomposition of nitrides and oxynitrides which are starting materials and products is suppressed. The oxygen partial pressure in the firing atmosphere is preferably 0.0001% or less in order to suppress the oxidation reaction of nitrides and oxynitrides as starting materials and products. In addition, although baking time changes also with baking temperatures, it is about 1 to 10 hours normally.

  In order to manufacture the phosphor in the form of powder or agglomerate, it is preferable to take a method in which the raw material is filled in a container in a state where the bulk density is kept at 40% or less and then fired. By setting the bulk density to 40% or less, it is possible to avoid strong adhesion between particles. Here, the relative bulk density is a ratio of a value (bulk density) obtained by dividing the mass of the powder filled in the container by the volume of the container and the true density of the substance of the powder.

  In the firing of the raw material mixture, various heat-resistant materials can be used as a container for holding the raw material compound. However, since the adverse effect of material deterioration on the metal nitride used in the present invention is low, the academic journal Journal of the. American Ceramic Society 2002 Vol. 85, No. 5, p. 1229 to p. 1234, as shown in the boron crucible-coated graphite crucible used for the synthesis of α-sialon, or a boron nitride-coated container, or boron nitride A sintered body is suitable.

  In order to produce the phosphor in the form of powder or aggregate, it is preferable that the average particle diameter of the raw material powder particles or aggregate is 500 μm or less because of excellent reactivity and operability. Use of a spray dryer, sieving, or air classification as a method for setting the particle size of the particles or aggregates to 500 μm or less is preferable because of excellent work efficiency and operability.

  The firing method is not a hot press, but a sintering method that does not apply mechanical pressure from the outside, such as an atmospheric pressure sintering method or a gas pressure sintering method, is a method for obtaining a powder or aggregate product. preferable.

  The average particle diameter of the phosphor powder is preferably 50 nm or more and 200 μm or less in terms of volume-based median diameter (d50) because the emission intensity is high. The volume-based average particle diameter can be measured by, for example, a microtrack or a laser scattering method. By using one or more methods selected from pulverization, classification, and acid treatment, the average particle size of the phosphor powder synthesized by firing may be adjusted to 50 nm to 200 μm.

  Defects in the powder or damage due to pulverization by heat-treating the phosphor powder after firing, phosphor powder after pulverization treatment, or phosphor powder after particle size adjustment at a temperature of 1000 ° C. or more and below the firing temperature May recover. Defects and damage may cause a decrease in emission intensity. In this case, the emission intensity is recovered by heat treatment.

  At the time of firing for phosphor synthesis, an inorganic compound that generates a liquid phase at a temperature lower than the firing temperature is added and fired, which acts as a flux and promotes reaction and grain growth to obtain stable crystals. This may improve the emission intensity. Fluoride, chloride, iodide, bromide of one or more elements selected from Li, Na, K, Mg, Ca, Sr, Ba as an inorganic compound that generates a liquid phase at a temperature lower than the firing temperature Or a mixture of one or more phosphates. Since these inorganic compounds have different melting points, they may be used properly depending on the synthesis temperature.

  Furthermore, by washing with a solvent after firing, the emission intensity of the phosphor may be increased by reducing the content of an inorganic compound that generates a liquid phase at a temperature lower than the firing temperature.

  When the phosphor of the present invention is used for a light emitting device or the like, it is preferable to use the phosphor in a form dispersed in a liquid medium. Moreover, it can also be used as a phosphor mixture containing the phosphor of the present invention. The phosphor of the present invention dispersed in a liquid medium is called a phosphor-containing composition. The liquid medium that can be used in the phosphor-containing composition of the present invention is a liquid medium that exhibits liquid properties under the desired use conditions, suitably disperses the phosphor of the present invention, and does not cause undesirable reactions. If there is, it is possible to select an arbitrary one according to the purpose. Examples of the liquid medium include addition-reactive silicone resins, condensation-reactive silicone resins, modified silicone resins, epoxy resins, polyvinyl resins, polyethylene resins, polypropylene resins, and polyester resins before curing. These liquid media may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  The amount of the liquid medium used may be appropriately adjusted according to the application, etc., but in general, the weight ratio of the liquid medium to the phosphor of the present invention is usually 3% by weight or more, preferably 5% by weight or more, Moreover, it is 30 weight% or less normally, Preferably it is the range of 15 weight% or less.

  In addition to the phosphor of the present invention and the liquid medium, the phosphor-containing composition of the present invention may contain other optional components depending on its use and the like. Examples of other components include a diffusing agent, a thickener, a bulking agent, and an interference agent. Specifically, silica-based fine powder such as Aerosil, alumina and the like can be mentioned.

  The light emitting device of the present invention is configured using at least a light emitter or a light emitting light source and the phosphor of the present invention.

  Examples of the light emitter or light source include an LED light emitting device, a laser diode light emitting device, an EL light emitting device, and a fluorescent lamp. The LED light emitting device can be manufactured by using the phosphor of the present invention by a known method as described in JP-A-5-152609, JP-A-7-99345, JP-A-2927279, and the like. In this case, it is desirable that the light emitter or the light source emits light having a wavelength of 330 to 500 nm, and among them, an ultraviolet (or purple) LED light emitting element of 330 to 420 nm or a blue LED light emitting element of 420 to 500 nm is preferable. Some of these LED light-emitting elements are made of a nitride semiconductor such as GaN or InGaN. By adjusting the composition, the LED light-emitting element can be a light-emitting light source that emits light of a predetermined wavelength.

  Examples of the light emitting device of the present invention include a white light emitting diode including the phosphor of the present invention, a lighting fixture including a plurality of white light emitting diodes, and a backlight for a liquid crystal panel.

  As one form of the light emitting device of the present invention, the light emitting body or light emitting light source emits ultraviolet or visible light having a peak wavelength of 300 to 500 nm, and the phosphor of the present invention emits yellow to red light, and the other phosphor of the present invention includes There is a light-emitting device that emits white light or light other than white light by mixing light having a wavelength of 450 nm or more.

As one form of the light-emitting device of the present invention, in addition to the phosphor of the present invention, a blue phosphor that emits light having a peak wavelength of 420 nm to 500 nm or less by a light emitter or a light source can be included. As such a blue phosphor, AlN: (Eu, Si), BaMgAl ₁₀ O ₁₇ : Eu, SrSi ₉ Al ₁₉ ON ₃₁ : Eu, LaSi ₉ Al ₁₉ N ₃₂ : Eu, α-sialon: Ce, JEM : Ce and the like.

As one form of the light emitting device of the present invention, in addition to the phosphor of the present invention, a green phosphor that emits light having a peak wavelength of 500 nm or more and 550 nm or less by a light emitting body or a light emitting light source can be included. Examples of such green phosphors include β-sialon: Eu, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu, and the like. is there.

As one form of the light emitting device of the present invention, in addition to the phosphor of the present invention, a yellow phosphor that emits light having a peak wavelength of 550 nm or more and 600 nm or less by a light emitter or a light source can be included. Examples of such a yellow phosphor include YAG: Ce, α-sialon: Eu, CaAlSiN ₃ : Ce, La ₃ Si ₆ N ₁₁ : Ce.

As one form of the light emitting device of the present invention, in addition to the phosphor of the present invention, a red phosphor that emits light having a peak wavelength of 600 nm or more and 700 nm or less by a light emitter or a light source can be included. Examples of such red phosphor include CaAlSiN ₃ : Eu, (Ca, Sr) AlSiN ₃ : Eu, Ca ₂ Si ₅ N ₈ : Eu, and Sr ₂ Si ₅ N ₈ : Eu.

  As an embodiment of the light-emitting device of the present invention, when an LED that emits light having a wavelength of 320 to 500 nm is used as the light emitter or the light-emitting light source, the light-emitting efficiency is high, so that a highly efficient light-emitting device can be configured.

  The image display device of the present invention is composed of at least an excitation source and the phosphor of the present invention, and includes a fluorescent display tube (VFD), a field emission display (FED), a plasma display panel (PDP), a cathode ray tube (CRT) and the like. is there. The phosphor of the present invention has been confirmed to emit light by excitation of vacuum ultraviolet rays of 100 to 190 nm, ultraviolet rays of 190 to 380 nm, electron beams, etc., and in combination of these excitation sources and the phosphor of the present invention, An image display apparatus as described above can be configured.

  Since the phosphor of the present invention comprising an inorganic compound crystal phase having a specific chemical composition has a yellow object color, it can be used as a pigment or a fluorescent pigment. That is, when the phosphor of the present invention is irradiated with illumination such as sunlight or a fluorescent lamp, a yellow object color is observed, but since the color is good and does not deteriorate over a long period of time, the phosphor of the present invention Is suitable for inorganic pigments. For this reason, when used for paints, inks, paints, glazes, colorants added to plastic products, etc., good color development can be maintained high over a long period of time.

  Since the nitride phosphor of the present invention absorbs ultraviolet rays, it is also suitable as an ultraviolet absorber. For this reason, when used as a paint, applied to the surface of a plastic product, or kneaded into a plastic product, the effect of blocking ultraviolet rays is high, and the product can be effectively protected from ultraviolet degradation.

  The present invention will be described in more detail with reference to the following examples, which are disclosed only as an aid for easily understanding the present invention, and the present invention is not limited to these examples. Absent.

[Raw materials used for synthesis]
The raw material powder used for the synthesis was a silicon nitride powder having a specific surface area of 11.2 m ² / g, an oxygen content of 1.29 wt%, and an α-type content of 95% (SN-E10 manufactured by Ube Industries, Ltd.). Grade), aluminum nitride powder having an oxygen content of 0.82% by weight (E grade made by Tokuyama Corporation), and aluminum oxide powder having a specific surface area of 13.2 m ² / g (Taimicron, manufactured by Daimei Chemical Co., Ltd.) And magnesium nitride (Mg ₃ N ₂ ; manufactured by High Purity Chemical Laboratory), calcium nitride (Ca ₃ N ₂ ; manufactured by High Purity Chemical Laboratory), and 99.5% pure strontium nitride (Sr ₃ N ₂ ; Manufactured by Shellac), barium nitride having a purity of 99.7% (Ba ₃ N ₂ ; manufactured by Shellac), europium oxide (Eu ₂ O ₃ ; manufactured by Shin-Etsu Chemical Co., Ltd.), and europium nitride ( E N: Metal europium was obtained by nitriding a metal by heating at 800 ° C. for 10 hours in an ammonia stream, boron nitride (manufactured by Denki Kagaku Kogyo), and rare earth oxide (purity 99.9% Shin-Etsu) Made by Chemical Industries).

[Synthesis and Structural Analysis of Crystalline Sr ₂ Si _2.30 Al _1.90 N _8.10 B _1.80 ]
Strontium nitride (Sr ₃ N ₂ ), silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN), and boron nitride (BN) have a cation ratio of Sr: Si: Al: B = 2: 2.3: 1.90. : The mixed composition was designed at a ratio of 1.80. These raw material powders were weighed so as to have the above mixed composition and mixed for 5 minutes in a glove box having an atmosphere of oxygen of 1 ppm or less using a silicon nitride sintered pestle and mortar. Next, the obtained mixed powder was put into a crucible made of a boron nitride sintered body. The bulk density of the mixed powder (powder) was about 33%.

The crucible containing the mixed powder was set in a graphite resistance heating type electric furnace. The firing operation is as follows. First, the firing atmosphere is evacuated at a pressure of 1 × 10 ⁻¹ Pa or less by a diffusion pump, heated from room temperature to 800 ° C. at a rate of 500 ° C. per hour, and the purity is 800.degree. Nitrogen was introduced to bring the pressure in the furnace to 1 MPa, the temperature was raised to 1800 ° C. at 500 ° C. per hour, and the temperature was maintained for 2 hours.

  The synthesized product was observed with an optical microscope, and crystal grains having a size of 22.8 μm × 20.3 μm × 6.5 μm were collected from the synthesized product. The particles were analyzed using a scanning electron microscope (SEM; SU1510 manufactured by Hitachi High-Technologies Corporation) equipped with an energy dispersive element analyzer (EDS; QUANTAX manufactured by Bruker AXS). Analysis was carried out. As a result, the presence of Sr, Si, Al, N, and B elements was confirmed.

  Next, this crystal was fixed to the tip of the glass fiber with an organic adhesive. This was measured using a single crystal X-ray diffractometer with a rotating counter cathode of MoKα rays (SMART APEX II Ultra manufactured by Bruker AXS) under the condition that the output of the X-ray source was 50 kV 50 mA. . As a result, it was confirmed that the crystal particles were a single crystal.

  Next, the crystal structure was obtained from the X-ray diffraction measurement result using single crystal structure analysis software (APEX2 manufactured by Bruker AXS). The obtained crystal structure data is shown in Table 1, and a diagram of the crystal structure is shown in FIG. Table 1 describes the crystal system, space group, lattice constant, atom type and atom position, and this data can be used to determine the shape and size of the unit cell and the arrangement of atoms in it. . Si and Al enter at the same atomic position and become the composition ratio of the crystal when averaged as a whole.

This crystal belongs to the hexagonal system (hexagonal), belongs to the space group P-62c, (International Tables for Crystallography No. 190 space group), and the lattice constants a, b, c are
a = 0.47965 nm, b = 0.47965 nm, c = 0.97932 nm, and the angles α, β, and γ were α = 90 °, β = 90 °, and γ = 120 °. The atomic positions are as shown in Table 1. In the table, Si and Al are present in the same atomic position at a certain ratio determined by the composition. In general, oxygen and nitrogen can enter the seat where X enters in a sialon-based crystal. However, since Sr is +2, Al is +3, and Si is +4, the atomic position, Sr and Al If the ratio of Si to Si is known, the ratio of O to N occupying the (O, N) position can be obtained from the electrical neutrality condition of the crystal. The difference between the starting material composition and the crystal composition is that a composition other than Sr ₂ Si _2.30 Al _1.90 N _8.10 B _1.80 was produced as a small amount of the second phase. Since a single crystal is used, the analysis result shows a pure Sr ₂ Si _2.30 Al _1.90 N _8.10 B _1.80 structure.

When the detailed crystal structure was examined, the Sr ₂ Si _2.30 Al _1.90 N _8.10 B _1.80 crystal had Sr ₂ Si ₂ Al ₂ N ₈ B ₂ and Sr ₂ having the same unit cell. It was found to be an average structure of crystal structure with Si ₅ Al ₁ N ₉ . Furthermore, the ratio of the two types of crystal structures was analyzed as Sr ₂ Si ₂ Al ₂ N ₈ B ₂ : Sr ₂ Si ₅ Al ₁ N ₉ = 9: 1. That is, this crystal was found to have an average structure of two types of crystal structures having the same crystal system, space group, and lattice constant but different atomic composition and atomic position.

When a crystal having a similar structure was examined, the crystal structure of the Sr ₂ Si _2.30 Al _1.90 N _8.10 B _1.80 crystal obtained by the analysis is represented by the general formula (1-x) A _2. It was found to be one of the crystals that can be described as B ₂ (D, E) ₄ X ₈ + xA ₂ (D, E) ₆ X ₉ (x is a numerical value of 0 ≦ x ≦ 1). Here, A is an element selected from Mg, Ca, Sr, and Ba, D is an element selected from Si, Ge, Sn, Ti, Zr, and Hf, and E is Al, Ga, In, Sc, Y, An element selected from La, X is an element selected from O, N, and F. These elements may be one kind or a mixture of two or more kinds.

A crystal represented by (1-x) A ₂ B ₂ (D, E) ₄ X ₈ + xA ₂ (D, E) ₆ X ₉ (x is a numerical value of 0 ≦ x ≦ 1) is Sr ₂ Si _{2. It} has the same crystal structure as ₃₀ Al _1.90 N _8.10 B _1.80 crystal, is a hexagonal crystal system, and has symmetry of P-62c. The elements A, B, D, E, and X are coordinates of Sr, B, Si, Al, and N in Sr ₂ Si _2.30 Al _1.90 N _8.10 B _1.80 shown in Table 1, respectively. Occupy position. However, the occupation ratio may vary from the values in Table 1 depending on the composition and the x value.

  From the crystal structure data, it was confirmed that this crystal was a novel substance that had not been reported so far. The powder X-ray diffraction pattern calculated from the crystal structure data is shown in FIG. From now on, the powder X diffraction measurement of the synthesized product will be performed, and if the measured powder pattern is the same as in FIG. 2, it can be determined that the N crystal of FIG. 1 is formed. In addition, when the crystal structure of the N crystal is changed while maintaining the crystal structure, the powder X-ray pattern can be calculated by calculation from the value of the lattice constant obtained by powder X-ray diffraction measurement and the crystal structure data of Table 1. Therefore, it can be determined that an N crystal is generated by comparing with the calculation pattern.

[Phosphor Examples and Comparative Examples; Examples 1 to 10]
According to the design composition shown in Table 2 and Table 3, the raw materials were weighed so as to have the mixed composition (molar ratio) shown in Table 4. Depending on the type of raw material used, the composition may differ between the design composition in Table 2 and the mixed composition in Table 4. In this case, the mixed composition was determined so that the amount of metal ions matched. The weighed raw material powders were mixed for 5 minutes using a silicon nitride sintered pestle and mortar. Thereafter, the mixed powder was put into a crucible made of a boron nitride sintered body. The bulk density of the powder was about 20% to 30%.

The crucible containing the mixed powder was set in a graphite resistance heating type electric furnace. The firing operation is as follows. First, the firing atmosphere is evacuated at a pressure of 1 × 10 ⁻¹ Pa or less by a diffusion pump, heated from room temperature to 800 ° C. at a rate of 500 ° C. per hour, and the purity is 800.degree. Nitrogen was introduced to set the pressure in the furnace to 1 MPa, the temperature was raised to 500 ° C. per hour to the set temperature shown in Table 5, and the temperature was maintained for the time shown in Table 5.

Next, the synthesized compound was pulverized using an agate mortar, and powder X-ray diffraction measurement was performed using Cu _Kα rays. The main product phase is shown in Table 6. As a result, it was confirmed that the phase having the same crystal structure as that of the N crystal was the main product phase. Moreover, it was confirmed from the measurement of EDS that the composite contains rare earth elements, alkaline earth metals, Si, Al, and B. That is, it was confirmed that the synthesized product was a phosphor in which rare earth luminescent ions M were dissolved in N crystal.

  After firing, the obtained fired body was coarsely pulverized and then ground by hand using a crucible made of a silicon nitride sintered body and a mortar, and passed through a 30 μm sieve. When the particle size distribution was measured, the average particle size was 3 to 8 μm.

  As a result of irradiating these powders with a lamp emitting light having a wavelength of 365 nm, it was confirmed that light was emitted from blue to red. The emission spectrum and excitation spectrum of this powder were measured using a fluorescence spectrophotometer. Table 7 shows the peak wavelength of the excitation spectrum and the peak wavelength of the emission spectrum. This phosphor can be excited by ultraviolet rays of 300 nm to 380 nm, violet or blue light of 380 nm to 500 nm, and was confirmed to be a phosphor emitting blue to red light. Further, in Examples 2, 3, 8, 9, and 10 to which Sr was added, it was confirmed that the phosphor emits yellow to red light.

  In addition, it is thought that the part in which the chemical composition of a mixed raw material composition and a synthetic | combination compound differs in a small amount in a synthetic | combination as an impurity 2nd phase.

  The powder X-ray diffraction result of the synthesized phosphor shows good agreement with the result of structural analysis (Fig. 2), the N crystal and X-ray diffraction pattern are the same, and the crystal with the same crystal structure as the N crystal is the main. It was confirmed to be an ingredient. For example, in Example 10, it can be seen that excitation can be efficiently performed with ultraviolet light or visible light, and in Examples 2, 3, 8, 9, and 10 to which Sr is added, the emission spectrum exhibits light emission having a peak at 550 to 650 nm. I understood

[Examples of Light Emitting Device and Image Display Device; Examples 11 to 14]
Next, a light emitting device using the phosphor of the present invention will be described.

[Example 11]
FIG. 5 is a schematic view showing a lighting fixture (bullet type LED lighting fixture) according to the present invention.

  A so-called bullet-type white light-emitting diode lamp (1) shown in FIG. 3 was produced. There are two lead wires (2, 3), one of which (2) has a recess, and an ultraviolet light-emitting diode element (4) having an emission peak at 365 nm is placed thereon. The lower electrode of the ultraviolet light emitting diode element (4) and the bottom surface of the recess are electrically connected by a conductive paste, and the upper electrode and the other lead wire (3) are electrically connected by a gold wire (5). It is connected to the. The phosphor (7) is dispersed in the resin and mounted in the vicinity of the light emitting diode element (4). The first resin (6) in which the phosphor is dispersed is transparent and covers the entire ultraviolet light emitting diode element (4). The tip of the lead wire including the recess, the blue light emitting diode element, and the first resin in which the phosphor is dispersed are sealed with a transparent second resin (8). The transparent second resin (8) has a substantially cylindrical shape as a whole, and has a lens-shaped curved surface at the tip, which is commonly called a shell type.

  In this example, the phosphor powder prepared by mixing the yellow phosphor prepared in Example 7 and the JEM: Ce blue phosphor at a mass ratio of 7: 3 was mixed in an epoxy resin at a concentration of 37% by weight, and this was added to a dispenser. The first resin (6) in which the appropriate amount (7) mixed with the phosphor was dispersed was formed by dropping an appropriate amount. The color of the obtained light emitting device was x = 0.33, y = 0.33, and was white.

[Example 12]
FIG. 4 is a schematic view showing a lighting fixture (substrate mounted LED lighting fixture) according to the present invention.

  A chip-type white light emitting diode lamp (11) for mounting on a substrate shown in FIG. 4 was produced. Two lead wires (12, 13) are fixed to a white alumina ceramic substrate (19) having a high visible light reflectivity, and one end of each of these wires is located at a substantially central portion of the substrate, and the other end is external. It is an electrode that is soldered when mounted on an electric board. One of the lead wires (12) has a blue light emitting diode element (14) having an emission peak wavelength of 450 nm placed and fixed at one end of the lead wire so as to be at the center of the substrate. The lower electrode of the blue light emitting diode element (14) and the lower lead wire are electrically connected by a conductive paste, and the upper electrode and the other lead wire (13) are electrically connected by a gold thin wire (15). Connected.

A mixture of the first resin (16), the phosphor prepared in the example, and the phosphor (17) in which the CaAlSiN ₃ : Eu red phosphor is mixed at a mass ratio of 9: 1 is mounted in the vicinity of the light emitting diode element. Has been. The first resin in which the phosphor is dispersed is transparent and covers the entire blue light emitting diode element (14). A wall surface member (20) having a shape with a hole in the center is fixed on the ceramic substrate. The wall member (20) has a central portion serving as a hole for holding the resin (16) in which the blue light emitting diode element (14) and the phosphor (17) are dispersed, and the portion facing the center is a slope. It has become. This slope is a reflection surface for extracting light forward, and the curved surface shape of the slope is determined in consideration of the light reflection direction. Further, at least the surface constituting the reflecting surface is a surface having a high visible light reflectance having white or metallic luster. In the present embodiment, the wall member (20) is made of a white silicone resin. The hole at the center of the wall member forms a recess as the final shape of the chip-type light-emitting diode lamp. Here, the first resin in which the blue light-emitting diode element (14) and the phosphor (17) are dispersed ( A transparent second resin (18) is filled so as to seal all of 16). In this example, the same epoxy resin was used for the first resin (16) and the second resin (18).

  Next, a design example of an image display device using the phosphor of the present invention will be described.

[Example 13]
FIG. 5 is a schematic view showing an image display device (plasma display panel) according to the present invention.

The red phosphor (31), the green phosphor (β-sialon: Eu ²⁺ ) (32) and the blue phosphor (BAM: Eu ²⁺ ) (33) of Example 10 of the present invention are placed on the glass substrate (44). It is apply | coated to the inner surface of each cell (34, 35, 36) arrange | positioned through an electrode (37, 38, 39) and a dielectric material layer (41). When the electrodes (37, 38, 39, 40) are energized, vacuum ultraviolet rays are generated by Xe discharge in the cell, which excites the phosphor and emits red, green, and blue visible light, which is the protective layer. (43), observed from the outside through the dielectric layer (42) and the glass substrate (45), and functions as an image display device.

[Example 14]
FIG. 6 is a schematic view showing an image display device (field emission display panel) according to the present invention.

  The red phosphor (56) of Example 10 of the present invention is applied to the inner surface of the anode (53). By applying a voltage between the cathode (52) and the gate (54), electrons (57) are emitted from the emitter (55). The electrons are accelerated by the voltage of the anode (53) and the cathode, collide with the red phosphor (56), and the phosphor emits light. The whole is protected by glass (51). The figure shows one light-emitting cell consisting of one emitter and one phosphor, but in fact, a display that can produce a variety of colors is constructed by arranging a large number of blue and green cells in addition to red. The The phosphor used for the green or red cell is not particularly specified, but a phosphor that emits high luminance with a low-speed electron beam may be used.

  The nitride phosphor of the present invention has emission characteristics (emission color, excitation characteristics, emission spectrum) different from those of conventional phosphors, and has high emission intensity even when combined with an LED of 470 nm or less. It is a nitride phosphor that is suitably used for VFD, FED, PDP, CRT, white LED, etc. because it is thermally stable and has little decrease in phosphor brightness when exposed to an excitation source. . In the future, it can be expected to contribute greatly to the development of the industry in material design for various display devices.

1. Cannonball type light emitting diode lamp.
2,3. Lead wire.
4). Light emitting diode element.
5. Bonding wire.
6,8. resin.
7). Phosphor.
11. Chip-type white light-emitting diode lamp for board mounting.
12,13. Lead wire.
14 Light emitting diode element.
15. Bonding wire.
16, 18. resin.
17. Phosphor.
19. Alumina ceramic substrate.
20. Side member.
31. Red phosphor.
32. Green phosphor.
33. Blue phosphor.
34, 35, 36. UV light emitting cell.
37, 38, 39, 40. electrode.
41, 42. Dielectric layer.
43. Protective layer.
44, 45. Glass substrate.
51. Glass.
52. cathode.
53. anode.
54. Gate.
55. Emitter.
56. Phosphor.
57. Electronic.

Claims (33)

At least A element, D element, E element, and X element (where A is one or more elements selected from Mg, Ca, Sr, and Ba, and D is Si, Ge, Sn, Ti, Zr, One or more elements selected from Hf, E is one or more elements selected from Al, Ga, In, Sc, Y, and La, and X is selected from O, N, and F 1 element or 2 or more elements), and optionally B element (boron),
(1) A structure represented by A ₂ B ₂ (D, E) ₄ X ₈ in the unit cell of the crystal, or
A structure represented by A ₂ (D, E) ₆ X ₉ or (1-x) A ₂ B ₂ (D, E) ₄ X ₈ + xA ₂ (D, E) ₆ X ₉ (where x is 0) A crystal including a structure represented by the above (numerical value of 1 or less) (hereinafter referred to as N crystal),
(2) an inorganic crystal having the same crystal structure as the N crystal,
(3) solid solution crystals of these crystals,
From an inorganic compound in which M element (where M is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb) is dissolved in any of the crystals A phosphor. The N crystal has an average structure of unit cell,
(1-x) A ₂ B ₂ (D, E) ₄ X ₈ + xA ₂ (D, E) ₆ X ₉
The phosphor according to claim 1, wherein x is a numerical value of 0 or more and 1 or less.   The phosphor according to claim 1, wherein the A element contains Sr, the D element contains Si, the E element contains Al, and the X element contains N.   The phosphor according to claim 1, wherein x is a numerical value in a range of 0.02 ≦ x ≦ 0.2. The phosphor according to claim 1, wherein the N crystal is Sr ₂ Si ₂₃₀ Al _1.90 N _8.10 B _1.80 .   The phosphor according to claim 1, wherein the N crystal or the inorganic crystal having the same crystal structure as the N crystal is a hexagonal crystal and has a symmetry of P62c. N crystal or an inorganic crystal having the same crystal structure as N crystal is a hexagonal crystal,
Lattice constants a, b, c are
a = 0.47965 ± 0.05 nm
b = 0.47965 ± 0.05 nm
c = 0.97932 ± 0.05 nm
The phosphor according to claim 1, wherein the phosphor has a value in the range. The inorganic compound formula _{B c M d A e D f} E g X h ( proviso that wherein c + d + e + f + g + h = 1, M is, Mn, Ce, Pr, Nd , Sm, Eu, Tb, Dy, Yb One or two or more elements selected from: A is one or more elements selected from Mg, Ca, Sr, Ba; D is selected from Si, Ge, Sn, Ti, Zr, Hf One or more elements selected from the above, E is one or more elements selected from Al, Ga, In, Sc, Y, and La, X is one selected from O, N, and F Parameters c, d, e, f, g, h are
0.1 ≦ c ≦ 0.25
0.00001 ≦ d ≦ 0.05
0.08 ≦ e ≦ 0.16
0.08 ≦ f ≦ 0.2
0 ≤ g ≤ 0.2
0.45 ≤ h ≤ 0.55
The phosphor according to claim 1, wherein the phosphor is represented by a composition in a range satisfying all of the above conditions.   The phosphor according to claim 1, wherein the inorganic compound is a single crystal particle or an aggregate of single crystals having an average particle diameter of 0.1 μm or more and 20 μm or less.   The phosphor according to claim 1, which is composed of a mixture of the phosphor composed of the inorganic compound according to claim 1 and another crystal phase or an amorphous phase, and the phosphor content is 20 mass% or more.   The phosphor according to claim 10, wherein the other crystal phase or amorphous phase is a conductive inorganic substance.   2. The phosphor according to claim 1, which contains Eu in M element and emits fluorescence having a peak in a wavelength range of 550 nm to 650 nm when irradiated with an excitation source.   The phosphor according to claim 12, wherein the excitation source is vacuum ultraviolet light, ultraviolet light, visible light, electron beam, or X-ray having a wavelength of 100 nm to 520 nm.   By firing the mixture of metal compounds, the raw material mixture that can constitute the phosphor according to claim 1 is fired in a temperature range of 1200 ° C. or higher and 2200 ° C. or lower in an inert atmosphere containing nitrogen. The manufacturing method of the fluorescent substance of Claim 1.   The mixture of the metal compounds is a compound containing B, a compound containing M, a compound containing A, a compound containing D, a compound containing E, and a compound containing X (provided that M is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Yb, and A is one or two elements selected from Mg, Ca, Sr, Ba The above elements, D is one or more elements selected from Si, Ge, Sn, Ti, Zr, and Hf, and E is one or more elements selected from Al, Ga, In, Sc, Y, and La The method for producing a phosphor according to claim 14, comprising two or more elements, wherein X is one or more elements selected from O, N, and F).   The compound containing M is a single substance or a mixture of two or more selected from metals, silicides, oxides, carbonates, nitrides, oxynitrides, chlorides, fluorides, or oxyfluorides containing M And the compound containing A is a simple substance or two kinds selected from metals containing A, silicides, oxides, carbonates, nitrides, oxynitrides, chlorides, fluorides, or oxyfluorides A mixture of the above, wherein the compound containing D is a single substance or two or more selected from metals, silicides, oxides, carbonates, nitrides, oxynitrides, chlorides, fluorides, or oxyfluorides The method for producing a phosphor according to claim 15, wherein the phosphor is a mixture of   A light-emitting device comprising at least a light-emitting body and a phosphor, wherein the phosphor according to claim 1 is used.   The light emitting device according to claim 17, wherein the light emitter is a light emitting diode (LED), a laser diode (LD), a semiconductor laser, or an organic EL light emitter (OLED) that emits light having a wavelength of 330 to 500 nm.   The light emitting device according to claim 17, wherein the light emitting device is a white light emitting diode, a lighting fixture including a plurality of white light emitting diodes, or a backlight for a liquid crystal panel.   The phosphor emits ultraviolet or visible light having a peak wavelength of 300 to 500 nm, and the yellow to red light emitted from the phosphor according to claim 1 is mixed with white light having a wavelength of 450 nm or more emitted from another phosphor. The light emitting device according to claim 17, wherein the light emitting device emits light other than light or white light.   The light emitting device according to claim 17, wherein the phosphor further includes a blue phosphor that emits light having a peak wavelength of 420 nm to 500 nm or less by the light emitter. The blue phosphor is selected from AlN: (Eu, Si), BaMgAl ₁₀ O ₁₇ : Eu, SrSi ₉ Al ₁₉ ON ₃₁ : Eu, LaSi ₉ Al ₁₉ N ₃₂ : Eu, α-sialon: Ce, JEM: Ce The light-emitting device according to claim 21.   The light emitting device according to claim 17, wherein the phosphor further includes a green phosphor that emits light having a peak wavelength of 500 nm or more and 550 nm or less by the light emitter. The green phosphor, _{beta-sialon: Eu, (Ba, Sr,} Ca, Mg) 2 SiO 4: Eu, (Ca, Sr, Ba) Si 2 O 2 N 2: according to claim 23 selected from Eu Light-emitting device.   The light emitting device according to claim 17, wherein the phosphor further includes a yellow phosphor that emits light having a peak wavelength of 550 nm or more and 600 nm or less by the light emitter. The yellow phosphor, YAG: Ce, α-sialon : Eu, CaAlSiN 3: Ce, La 3 Si 6 N 11: light-emitting device according to claim 25 selected from Ce.   The light emitting device according to claim 17, wherein the phosphor further includes a red phosphor that emits light having a peak wavelength of 600 nm to 700 nm by the light emitter. The red _{phosphor, CaAlSiN 3: Eu, (Ca} , Sr) AlSiN 3: Eu, Ca 2 Si 5 N 8: Eu, Sr 2 Si 5 N 8: light emitting device according to claim 27 selected from Eu.   43. The light emitting device according to claim 42, wherein the light emitter is an LED that emits light having a wavelength of 320 to 500 nm.   An image display device comprising an excitation source and a phosphor, wherein at least the phosphor according to claim 1 is used.   The image according to claim 30, wherein the image display device is any one of a fluorescent display tube (VFD), a field emission display (FED), a plasma display panel (PDP), a cathode ray tube (CRT), and a liquid crystal display (LCD). Display device.   A pigment comprising the inorganic compound according to claim 1. An ultraviolet absorber comprising the inorganic compound according to claim 1.