JP2017179019A - Phosphor, method for producing the same, light emitting device, image display, pigment, and ultraviolet absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a phosphor which has a high light emission intensity even in combination with an LED of 470 nm or less, and is chemically and thermally stable.SOLUTION: The phosphor according to the present invention comprises either: an inorganic crystal containing a metallic element M and a nonmetallic element X and represented by MX(n being a numerical value in the range of 3≤n≤52); an inorganic crystal having the same crystalline structure; or an inorganic compound that is a solid solution, in an inorganic crystal being a solid solution of them, of an element A (A being one or more elements selected from among Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy and Yb). Here, M comprises at least Al, Si and an optional element L (the element L being a metallic element other than Al and Si), and X comprises at least N, optional O, and an optional element Z (the element Z being a nonmetallic element other than N and O).SELECTED DRAWING: Figure 1

Description

The present invention uses, as a base crystal, an inorganic crystal represented by M _n X _{n + 1} containing at least a metal element M and a non-metal element X, an inorganic crystal having the same crystal structure, or an inorganic crystal that is a solid solution thereof. The present invention relates to a phosphor, a manufacturing method thereof, and an application 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-Emitter 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. A further object of the present invention is to provide a pigment and an ultraviolet absorber 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 N in the crystal structure with another element. Inorganic crystal represented by M _n X _{n + 1} containing a metal element M and a non-metal element X (where n is a numerical value in the range of 3 ≦ n ≦ 52), an inorganic crystal having the same crystal structure, or It has been found that an inorganic compound in which a luminescent ion is dissolved in an inorganic crystal based on these solid crystals as an inorganic crystal becomes a new phosphor. In particular, fluorescence based on an inorganic crystal represented by Si _x Al _14-x O _3-x N _{12 + x} (0 <x ≦ 3), an inorganic crystal having the same crystal structure, or an inorganic crystal that is a solid solution thereof. The body was found to emit high intensity fluorescence. In addition, it has been found that a specific composition emits blue to green light.

  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.

The phosphor according to the present invention is an inorganic crystal represented by M _n X _{n + 1} containing at least a metal element M and a non-metal element X (where n is a numerical value in a range of 3 ≦ n ≦ 52, and the metal element M is It contains at least Al (aluminum), Si (silicon), and, if necessary, L element (L element is a metal element other than Al or Si), and the nonmetallic element X is at least N (nitrogen) And, if necessary, O (oxygen), and, if necessary, a Z element (Z element is a nonmetallic element other than N and O), an inorganic crystal having the same crystal structure, or these An inorganic compound in which an A element (where A is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb) is dissolved in an inorganic crystal that is a solid solution of wherein the inorganic represented by _{M n X} n _{+ 1 Akira,} inorganic crystals represented by _{Si x Al 14-x O 3} -x N 12 + x ( however, 0 <x ≦ 3) is, thereby solving the above problems.
The inorganic crystal having the same crystal structure may be an inorganic crystal represented by (Si, Al) ₁₄ (O, N) ₁₅ .
An inorganic crystal represented by Si _x Al _14-x O _3-x N _{12 + x} , an inorganic crystal having the same crystal structure as this, or an inorganic crystal of these solid solutions is a tetragonal crystal (orthorhombic crystal). Having the symmetry of the space group Cmcm, and the lattice constants a, b, c are
a = 0.30722 ± 0.05 nm
b = 1.87210 ± 0.05 nm
c = 4.14890 ± 0.05 nm
It may be a value in the range.
The x value may be 1.5 ≦ x ≦ 3.
The x value may be 2 ≦ x ≦ 2.9.
The element A may be Eu.
The inorganic compound has a composition formula Si _a Al _b O _c N _d A _e Q _f (where a + b + c + d + e + f = 1, and A is Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Yb 1 or 2 or more elements selected from the above, Q is represented by 1 or 2 or more elements selected from elements other than Al, Si, O, N, and A), and parameters a, b, c, d, e, f
0.012 ≦ a ≦ 0.1031
0.378 ≦ b <0.48
0 ≦ c <0.103
0.412 <d <0.516
0.0001 ≤ e ≤ 0.03
0 ≤ f ≤ 0.3
A value in a range that satisfies all of the above conditions may be used.
The parameters a, b, c, d, e, f are
0.0172 ≦ a ≦ 0.1031
0.378 ≦ b ≦ 0.4639
0 ≦ c ≦ 0.0859
0.4296 ≤ d ≤ 0.5155
0.0001 ≦ e ≦ 0.0196
0 ≤ f ≤ 0.0233
A value in a range that satisfies all of the above conditions may be used.
The parameters a, b, c, d, e, f are
0.0515 ≤ a ≤ 0.1031
0.378 ≦ b ≦ 0.4296
0 ≤ c ≤ 0.0515
0.4639 ≤ d ≤ 0.5155
0.0001 ≦ e ≦ 0.0196
0 ≤ f ≤ 0.0233
A value in a range that satisfies all of the above conditions may be used.
The parameters a, b, c, d, e, f are
0.0687 ≤ a ≤ 0.1031
0.378 ≦ b ≦ 0.4124
0 ≦ c ≦ 0.0344
0.4811 ≤ d ≤ 0.5155
0.0004 ≦ e ≦ 0.0196
0 ≤ f ≤ 0.0233
A value in a range that satisfies all of the above conditions may be used.
The inorganic compound may be a single crystal particle having an average particle size of 0.1 μm or more and 40 μm or less or a single crystal aggregate.
The phosphor may be composed of a mixture of the above-described inorganic compound and another crystal phase or an amorphous phase, and the phosphor content may be 20% by mass or more.
Fluorescence having a peak at a wavelength in the range of 460 nm to 500 nm may be emitted by irradiating the excitation source.
The excitation source may be vacuum ultraviolet light, ultraviolet light, visible light, electron beam, or X-ray having a wavelength of 100 nm to 420 nm.
The above-described method for producing a phosphor according to the present invention is a mixture of metal compounds, which is fired to convert a raw material mixture that can constitute the above-described phosphor into a nitrogen-containing inert atmosphere at 1200 ° C. or higher and 2200 ° C. Firing is performed in the following temperature range, thereby solving the above problem.
The mixture of the metal compounds is AlN and / or Al ₂ O ₃ , Si ₃ N _4, and an oxide or nitride of A (where A is Mn, Ce, Pr, Nd, Sm, Eu, Tb, Or one or more elements selected from Dy and Yb).
The metal compound in the form of powder or aggregate may be fired after filling the container in a state where the bulk density is kept at 40% or less.
The light-emitting device of the present invention includes at least a light emitter and a phosphor, and the phosphor uses at least the above-described phosphor, thereby solving the above-described problems.
The light emitter may be 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 may be a white light emitting diode, a lighting fixture including a plurality of the white light emitting diodes, or a backlight for a liquid crystal panel.
The phosphor emits ultraviolet light or visible light having a peak wavelength of 300 to 450 nm, and mixes blue light or green light emitted by the above-described phosphor with light having a wavelength of 450 nm or more emitted by another phosphor. Light other than white light may be emitted.
The image display device of the present invention includes an excitation source and a phosphor, and the phosphor includes at least the above-described phosphor, thereby solving the above-described problem.
The image display device may be any one of a fluorescent display tube (VFD), a field emission display (FED), a plasma display panel (PDP), a cathode ray tube (CRT), or a liquid crystal display (LCD).
The pigment according to the present invention comprises the above-described phosphor, thereby solving the above-mentioned problems.
The ultraviolet absorber according to the present invention comprises the above-mentioned phosphor, thereby solving the above-mentioned problems.

The phosphor of the present invention has the same crystal structure as a multi-nitride containing Si and Al or a multi-component oxynitride, especially an inorganic crystal represented by M _n X _{n + 1} (3 ≦ n ≦ 52). An inorganic crystal or an inorganic crystal that is a solid solution thereof is contained as a base crystal. More preferably, as an inorganic crystal represented by M _n X _{n + 1} (3 ≦ n ≦ 52), an inorganic material represented by Si _x Al _14-x O _3−x N _{12 + x} (0 <x ≦ 3) in which n = 14 By containing an inorganic crystal having the same crystal structure as that of the crystal, Si _x Al _14-x O _3-x N _{12 + x} , or an inorganic crystal that is a solid solution thereof as a main component, It emits light with higher brightness than the oxide phosphors and oxynitride phosphors, and is excellent as a blue to green 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.

_{Si x Al 14-x O 3} -x N 12 + x (0 <x ≦ 3) illustrates the crystal structure of the crystal. _{Si x Al 14-x O 3} -x N 12 + x (0 <x ≦ 3) shows a powder X-ray diffraction using a CuKα ray calculated from the crystal structure of the crystal. The figure which shows the powder X-ray-diffraction result of the fluorescent substance synthesize | combined in Example 51. FIG. The figure which shows the excitation spectrum and emission spectrum of the fluorescent substance synthesize | combined in Example 51. FIG. 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 an inorganic crystal represented by M _n X _{n + 1} containing at least a metal element M and a non-metal element X (where n is a numerical value in the range of 3 ≦ n ≦ 52), and the same crystal structure Or an A element (where A is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb). ) Contains a solid solution inorganic compound as a main component, and exhibits high luminance. However, the metal element M includes at least Al (aluminum), Si (silicon), and, if necessary, an L element (L element is a metal element other than Al and Si), and the nonmetallic element X is It contains at least N (nitrogen), O (oxygen) as necessary, and Z element (Z element is a nonmetallic element other than N and O) as necessary.

In particular, the inorganic crystal represented by M _n X _{n + 1} is generally represented by Si _x Al _{m + 2-x} O _3-x N _{m + x} (where m = n−2, 0 <x ≦ 3, and 1 ≦ m ≦ 50). The phosphor based on the inorganic crystal represented by the formula is a phosphor that has high emission intensity and whose color tone can be controlled by changing the composition.

In addition, the inorganic crystal represented by M _n X _{n + 1} has a homologous structure. As the number of n increases, the longest lattice axis (c-axis in general notation) extends. The remaining two axes (a-axis and b-axis) are almost the same value.

  Preferably, the phosphor in which the value of x is 1.5 ≦ x ≦ 2.9 has high emission intensity. More preferably, the phosphor in which the value of x is 2 ≦ x ≦ 2.9 has particularly high emission intensity.

  Further, the phosphor having a value of m of 5 ≦ m ≦ 20 has particularly high emission intensity.

  The value of n is represented by an integer number.

  In addition, the phosphor in which the value of n is 9 ≦ n ≦ 15 has particularly high emission intensity.

An inorganic crystal represented by M _n X _{n + 1} , an inorganic crystal having the same crystal structure, or an inorganic crystal that is a solid solution thereof is a tetragonal (orthorhombic) crystal, which is stable. The phosphor used as the host crystal has high emission intensity. In this specification, it should be noted that “tetragonal” is used as a term intended for “Orthohombic” based on a resolution of the General Meeting of the Crystallographic Society of Japan held in 2014 (for example, Japan) (See Journal of Crystallographic Society 57, 131-133 (2015)).

An inorganic crystal represented by M _n X _{n + 1} , an inorganic crystal having the same crystal structure, or an inorganic crystal that is a solid solution thereof is a tetragonal crystal (orthorhombic crystal), and is represented by a space group Cmcm. The obtained crystals are particularly stable, and phosphors using these as host crystals have high emission intensity.

An inorganic crystal represented by M _n X _{n + 1} , an inorganic crystal having the same crystal structure, or an inorganic crystal that is a solid solution thereof is a tetragonal crystal (orthorhombic crystal) and has a symmetry of the space group Cmcm. The lattice constants a, b, c are
a = 0.31 ± 0.05 nm
b = 1.87 ± 0.2 nm
c = 0.275 × (n + 1) ± 0.1 nm (where 3 ≦ n ≦ 52)
Those having values in the range are particularly stable in crystals, 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.

An inorganic crystal represented by M _n X _{n + 1} , an inorganic crystal having the same crystal structure, or an inorganic crystal that is a solid solution thereof is a tetragonal crystal (orthorhombic crystal) and has a symmetry of the space group Cmcm. The lattice constants a, b, c are
a = 0.31 ± 0.05 nm
b = 1.87 ± 0.2 nm
c = 0.275 × (n + 1) ± 0.1 nm (where 3 ≦ n ≦ 52)
Value in the range of
(1) When n is an even number,
The atomic coordinates Mi of the M element contained in the unit cell are
(0, (4 + 6i-3n) /16±0.05, (1/4 + (i−1) / (2n)) ± 0.05), where 1 ≦ i ≦ n + 1 (n + 1 in total) ,
The atomic coordinate Xi of the X element is
(0, (4 + 6i-3n) /16±0.05, (1/4 + (i-1) / (2n + 1)) ± 0.05), where 1 ≦ i ≦ n + 2 (n + 2 in total) ,
(2) When n is an odd number,
The atomic coordinates Mj of the M element contained in the unit cell are
(0, (8 + 6j-3n) /16±0.05, (1/4 + (j−1) / (2n)) ± 0.05), where 1 ≦ j ≦ n + 1 (n + 1 in total) ,
The atomic coordinate Xj of the X element is
(0, (4 + 6j-3n) /16±0.05, (1/4 + (j−1) / (2n + 1)) ± 0.05), where 1 ≦ j ≦ n + 2 (n + 2 in total) In particular, crystals are particularly stable, and phosphors using these as host crystals have high emission intensity.

Such an inorganic compound has a composition formula Si _a Al _b O _c N _d A _e Q _f (where a + b + c + d + e + f = 1, and A is Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy , Yb, one or more elements selected from Yb, and Q is one or more elements selected from elements other than Al, Si, O, N, and A), and parameters a, b, c, d, e, f are
0.0117 ≦ a ≦ 0.3472
0.0694 ≦ b ≦ 0.4812
0 ≤ c ≤ 0.2283
0.3261 ≤ d ≤ 0.53
0.0001 ≤ e ≤ 0.03
0 ≦ f ≦ 0.3 (provided that when there are a plurality of Q elements, f is the sum of parameters of the respective elements)
A phosphor expressed by a composition in a range that satisfies all of the above conditions has particularly high emission intensity.

  The parameter a is a parameter representing the composition of the Si element, and if it is less than 0.0117 or higher than 0.3472, the crystal structure becomes unstable and the emission intensity decreases. The parameter b is a parameter representing the composition of the Al element. When the parameter b is less than 0.0694 or higher than 0.4812, the crystal structure becomes unstable and the light emission intensity decreases. The parameter c is a parameter representing the composition of the O element. When the parameter c is higher than 0.2283, the crystal structure becomes unstable and the emission intensity decreases. Moreover, considering the impurity oxygen contained in the powder raw material, there is no problem even if oxygen is contained in a range not exceeding 0.2283 (for example, c is more than 0, more preferably 0.001 or more). The emission intensity can be improved. The parameter d is a parameter representing the composition of the N element, and if it is less than 0.3261 or higher than 0.53, the crystal structure becomes unstable and the emission intensity decreases. The parameter e is the addition amount of the activating element A. If it is less than 0.0001, the amount of luminescent ions is insufficient and the luminance is lowered. If it exceeds 0.03, the emission intensity may decrease due to concentration quenching due to the interaction between the luminescent ions. The parameter f is a parameter representing the composition of the Q element other than the Al, Si, O, N, and A elements. When the parameter f is higher than 0.3, the crystal structure becomes unstable and the emission intensity decreases. The composition of the parameters of each element is determined such that neutral charges of the Al, Si, and A elements that are cations, the O and N that are anions, and the Q element are maintained.

Preferably, the parameters a, b, c, d, e, f are
0.0199 ≦ a ≦ 0.2747
0.1648 ≦ b ≦ 0.4642
0 ≦ c ≦ 0.0996
0.4183 ≤ d ≤ 0.5213
0.0004 ≦ e ≦ 0.0196
0 ≤ f ≤ 0.0233
A crystal having a value in a range that satisfies all of the above conditions has a stable crystal structure and particularly high emission intensity.

Inorganic crystals represented by _{M n X n + 1, Si} x Al m + 2-x O 3-x N m + x (m = n-2,0 <x ≦ 3, and, 1 ≦ m ≦ 50) inorganic crystals represented by Among the phosphors used as the matrix, an inorganic crystal (simply Si _x Al _14-x ) represented by Si _x Al _14-x O _3-x N _{12 + x} (0 <x ≦ 3) of m = 12 (n = 14). O _3−x N _{12 + x} crystal), Si _x Al _14−x O _3−x N _{12 + x} (0 <x ≦ 3), a crystal having the same crystal structure as the inorganic crystal, or a solid solution thereof An inorganic compound in which an element A (where A is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb) is dissolved in a certain inorganic crystal is particularly high. Indicates brightness.

From the present invention, an inorganic crystal represented by Si _x Al _14-x O _3-x N _{12 + x} (0 <x ≦ 3) was newly synthesized by the present inventors and confirmed to be a new crystal by crystal structure analysis. It has not been reported before.

FIG. 1 is a diagram showing a crystal structure of a Si _x Al _14-x O _3-x N _{12 + x} crystal.

According to the present inventors have synthesized _{Si x Al 14-x O 3} -x N 12 + x single crystal structure analysis was performed on the _{crystal, Si x Al 14-x O} 3-x N 12 + x crystals rectangular tetragonal (rhombic It belongs to the Cmcm space group (the 63rd space group of International Tables for Crystallography) 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 Si, Al, O, and N exists, and Si and Al do not distinguish between the seats, and SiAl (1) to SiAl (11), SiAl (12A) to SiAl (15A), And the analysis result which exists in 19 types of seats of SiAl (15B) from SiAl (12B) was obtained. Furthermore, O and N obtained the analysis result which exists in 16 types of same seats of ON (1) to ON (16).

As a result of the analysis using the data in Table 1, the Si _x Al _14-x O _3-x N _{12 + x} crystal has the structure shown in FIG. 1, and is a tetrahedron composed of a combination of Si or Al and O or N. It was found to have a skeletal structure. In this crystal, the element A which becomes an activating ion such as Eu is incorporated into the crystal in a form that locally substitutes O or N1 and four Si or Al bonded to the O or N. It is estimated to be.

As a crystal having the same crystal structure as the synthesized and structurally analyzed Si _x Al _14-x O _3-x N _{12 + x} crystal, there is a (Si, Al) ₁₄ (O, N) ₁₅ crystal. In the (Si, Al) ₁₄ (O, N) ₁₅ crystal, in the Si _x Al _14-x O _3-x N _{12 + x} crystal, Si and Al enter the seats where Si and Al enter without distinguishing each other. , O and N can enter without being distinguished from each other. Thereby, while maintaining the crystal structure, the ratio of the number of atoms of O and N can be made to 15 in total with respect to the total of 14 elements of Si and Al. However, it is desirable that the Si / Al ratio and the O / N ratio satisfy the condition that the electrical neutrality in the crystal is maintained.

In the following, for _simplicity, an inorganic crystal having a _{Si x Al 14-x O 3} -x N inorganic crystals represented by _{12 + x, Si x Al 14} -x O 3-x N 12 + x crystal and the same crystal structure, these Inorganic crystals that are solid solutions are collectively referred to as Si _x Al _14-x O _3-x N _{12 + x-} based crystals.

The Si _x Al _14-x O _3-x N _{12 + x} crystal of the present invention can be identified by X-ray diffraction or neutron diffraction. As the substance having an _{Si x Al 14-x O 3} -x N 12 + x X -ray diffraction results same diffraction and crystals in this _invention, the _{Si x Al 14-x O 3} -x N 12 + x crystal and the same crystal structure For example, there is an inorganic crystal represented by (Si, Al) ₁₄ (O, N) ₁₅ . Furthermore, there is a crystal whose lattice constant or atomic position is changed by replacing a constituent element with another element in a Si _x Al _14-x O _3-x N _{12 + x} crystal. Here, the element replaced with another element is, for example, a part of Si in a Si _x Al _14-x O _3-x N _{12 + x} crystal, or a part of Al, L other than Si and Al. There is one substituted with an element (where L is a metal element other than Si or Al). Further, there is a crystal in which part or all of O in the crystal or part of N is substituted with a Z element other than O and N (where Z is a nonmetallic element other than O and N). These substitutions are made so that the overall charge in the crystal is neutral. Those whose crystal structure does not change as a result of element substitution are Si _x Al _14-x O _3-x N _{12 + x-} based crystals. Substitution of elements changes the light emission characteristics, chemical stability, and thermal stability of the phosphor. Therefore, it is preferable that the phosphor is selected in a timely manner according to the application within a range in which the crystal structure is maintained.

The lattice constant of the Si _x Al _14-x O _3-x N _{12 + x-} based crystal changes when its constituent components are replaced with other elements, or when an activating element such as Eu is solid-solved. The atomic position given by the structure and the site occupied by the atom and its coordinates does not change so much that the chemical bond between the skeletal atoms is broken. In the present invention, Al-N, Al-O, Si-N, Si calculated from lattice constants and atomic coordinates obtained by Rietveld analysis of the results of X-ray diffraction and neutron diffraction in the Cmcm space group. -O chemical bond length (distance between adjacent atoms) calculated from the lattice constant and atomic coordinates of Si _x Al _14-x O _3-x N _{12 + x} (x = 3) crystal shown in Table 1 If it is within ± 5% compared to the length of, the same crystal structure is defined and it is determined whether or not it is a Si _x Al _14-x O _3-x N _{12 + x-} based crystal. This criterion is that, according to experiments, in a Si _x Al _14-x O _3-x N _{12 + x-} based crystal, when the chemical bond length changes beyond ± 5%, the chemical bond is broken to form another crystal. This is because it was confirmed.

Furthermore, when the amount of the solid solution is small, there is the following method as a simple determination method for the Si _x Al _14-x O _3-x N _{12 + x} crystal. 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 Si _x Al _14-x O _3-x N _{12 + x} crystal.

By comparing the substance to be compared with FIG. 2, it is possible to easily determine whether the Si _x Al _14-x O _3-x N _{12 + x-} based crystal is present. The main peak of the Si _x Al _14-x O _3-x N _{12 + x-} based crystal may be determined by about 10 having strong diffraction intensity. Table 1 is important in that sense and serves as a reference in specifying Si _x Al _14-x O _3-x N _{12 + x-} based crystals. Further, an approximate structure can be defined even if another crystal system of a tetragonal crystal (orthorhombic system) is used as the crystal structure of the Si _x Al _14-x O _3-x N _{12 + x} system crystal. However, the X-ray diffraction results (for example, FIG. 2) and the crystal structure (for example, FIG. 1) are not changed, and the identification method and identification results using the same are the same. It becomes a thing. Therefore, in the present invention, X-ray diffraction analysis is performed as a tetragonal system (orthorhombic 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.

At least one element selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb is added as an A element to a Si _x Al _14-x O _3-x N _{12 + x-} based crystal. When activated, a phosphor is obtained. Since emission characteristics such as excitation wavelength, emission wavelength, emission intensity and the like vary depending on the composition of the Si _x Al _14-x O _3-x N _{12 + x} crystal and the type and amount of the activation element, it may be selected according to the application. .

Inorganic crystals represented by _{Si x Al 14-x O 3} -x N 12 + x, inorganic crystals having a _{Si x Al 14-x O 3} -x N same crystal structure as the inorganic crystal represented by _{12 + x,} or solid solutions thereof The inorganic crystal is a tetragonal (orthorhombic) crystal, has a symmetry of the space group Cmcm, and the lattice constants a, b, c are
a = 0.30722 ± 0.05 nm
b = 1.87210 ± 0.05 nm
c = 4.14890 ± 0.05 nm
Those having values in the range are particularly stable in crystals, 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.

  Preferably, the phosphor satisfying 1.5 ≦ x ≦ 3 has high emission intensity. More preferably, the emission intensity of the phosphor satisfying 1.8 ≦ x ≦ 3 is further high, and the emission intensity of the phosphor satisfying 2 ≦ x ≦ 3 is particularly high. Considering impurity oxygen in the raw material, it is preferable to set the upper limit of x to 2.9 or less because a phosphor with high emission intensity can be obtained without high-precision control during production.

  The activation element A includes at least Eu. Thereby, a phosphor having a particularly high emission intensity can be obtained.

Preferably, composition formula Si _a Al _b O _c N _d A _e Q _f (wherein, a + b + c + d + e + f = 1, and A is selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Yb) One or two or more elements, Q is represented by one or more elements selected from elements other than Al, Si, O, N, and A), and parameters a, b, c, d, e and f are
0.012 ≦ a ≦ 0.1031
0.378 ≦ b <0.48
0 ≦ c <0.103
0.412 <d <0.516
0.0001 ≤ e ≤ 0.03
0 ≦ f ≦ 0.3 (provided that when there are a plurality of Q elements, f is the sum of parameters of the respective elements)
A phosphor expressed by a composition in a range that satisfies all of the above conditions has particularly high emission intensity.

  The parameter a is a parameter representing the composition of the Si element. If the parameter a is less than 0.012 or higher than 0.1031, the crystal structure becomes unstable and the emission intensity decreases. The parameter b is a parameter representing the composition of the Al element, and if it is less than 0.378 or 0.48 or more, the crystal structure becomes unstable and the emission intensity decreases. The parameter c is a parameter representing the composition of the O element, and if it is 0.103 or more, the crystal structure becomes unstable and the emission intensity decreases. Further, considering the impurity oxygen contained in the powder raw material, there is no problem even if oxygen is contained in a range not exceeding 0.103 (for example, c is more than 0, more preferably 0.001 or more). The emission intensity can be improved. The parameter d is a parameter representing the composition of the N element, and if it is 0.412 or less or 0.516 or more, the crystal structure becomes unstable and the emission intensity decreases. The parameter e is the addition amount of the activating element A. If it is less than 0.0001, the amount of luminescent ions is insufficient and the luminance is lowered. If it exceeds 0.03, the emission intensity may decrease due to concentration quenching due to the interaction between the luminescent ions. The parameter f is a parameter representing the composition of the Q element other than the Al, Si, O, N, and A elements. When the parameter f is higher than 0.3, the crystal structure becomes unstable and the emission intensity decreases. The composition of the parameters of each element is determined such that neutral charges of the Al, Si, and A elements that are cations, the O and N that are anions, and the Q element are maintained.

More preferably, the parameters a, b, c, d, e, f are
0.0172 ≦ a ≦ 0.1031
0.378 ≦ b ≦ 0.4639
0 ≦ c ≦ 0.0859
0.4296 ≤ d ≤ 0.5155
0.0001 ≦ e ≦ 0.0196
0 ≤ f ≤ 0.0233
A crystal having a value in a range that satisfies all of the above conditions has a stable crystal structure and high emission intensity.

More preferably, the parameters a, b, c, d, e, f are
0.0515 ≤ a ≤ 0.1031
0.378 ≦ b ≦ 0.4296
0 ≤ c ≤ 0.0515
0.4639 ≤ d ≤ 0.5155
0.0001 ≦ e ≦ 0.0196
0 ≤ f ≤ 0.0233
A crystal having a value in a range that satisfies all of the above conditions has a stable crystal structure and particularly high emission intensity.

Preferably, the parameters a, b, c, d, e, f are
0.0687 ≤ a ≤ 0.1031
0.378 ≦ b ≦ 0.4124
0 ≦ c ≦ 0.0344
0.4811 ≤ d ≤ 0.5155
0.0004 ≦ e ≦ 0.0196
0 ≤ f ≤ 0.0233
A crystal having a value in a range that satisfies all of the above conditions has a stable crystal structure and a high emission intensity.

  Since phosphors that are single crystal particles or aggregates of single crystals having an average particle size of 0.1 μm or more and 40 μm or less have high luminous efficiency and good operability when mounted on an LED, the particle size in this range is It is better to control.

  Fe, Co, and Ni impurity elements contained in the inorganic compound may cause a decrease in emission intensity. When the total of these elements in the phosphor is 500 ppm or less, the influence of the decrease in emission intensity is reduced.

As one embodiment of the present invention, an inorganic crystal represented by M _n X _{n + 1} containing at least a metal element M and a non-metal element X (where n is a numerical value in the range of 3 ≦ n ≦ 52), the same as that An inorganic crystal having a crystal structure or an inorganic crystal that is a solid solution of these is composed of a mixture of a phosphor composed of an inorganic compound in which luminescent ions are solid-solubilized and another crystal phase or an amorphous phase, There is a phosphor having a phosphor content of 20% by mass or more. In the case _where an inorganic crystal represented by M _n X _{n + 1} , an inorganic crystal having the same crystal structure, or a phosphor alone composed of an inorganic compound based on an inorganic crystal that is a solid solution thereof, the target characteristics cannot be obtained or This embodiment may be used when a function such as conductivity is added. The content of the phosphor composed of an inorganic compound represented by M _n X _{n + 1} , an inorganic crystal having the same crystal structure, or an inorganic compound based on these solid crystals is adjusted according to the intended characteristics. However, if it is less than 20% by mass, the emission intensity may be lowered. For this reason, the quantity made into a main component is 20 mass% or more.

  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 460 nm to 500 nm when irradiated with an excitation source. For example, an inorganic crystal represented by M _n X _{n + 1} activated with Eu, an inorganic crystal having the same crystal structure as that, or a phosphor based on an inorganic crystal that is a solid solution thereof, has a range within this range by adjusting the composition. Has an emission peak.

  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 having an excitation source with a wavelength of 100 nm to 420 nm. By using these excitation sources, light can be emitted efficiently.

  As described above, the phosphor of the present invention has a broad excitation range of electron beam, X-ray, and ultraviolet to visible light, and emits light from blue to green, compared with normal oxide phosphors and existing sialon phosphors. In particular, a specific composition is characterized by exhibiting blue to green of 460 nm to 500 nm, and the emission wavelength and emission peak width are adjustable. Thus, the phosphor of the present invention is suitable for lighting fixtures, image display devices, pigments, and ultraviolet absorbers due to such light emission characteristics. The phosphor of the present invention is also excellent in heat resistance because it does not deteriorate even when exposed to high temperatures, and also has the advantage of excellent long-term stability in an oxidizing atmosphere and moisture environment, and is durable. Products with excellent properties can be provided.

A method for producing such a phosphor of the present invention is not particularly limited. For example, the phosphor is a mixture of metal compounds and, when fired, has at least an inorganic crystal represented by M _n X _{n + 1} and the same crystal structure as the inorganic crystal. A raw material mixture capable of constituting a phosphor made of an inorganic compound based on an inorganic crystal or an inorganic crystal that is a solid solution of these is fired in a temperature range of 1200 ° C. to 2200 ° C. in an inert atmosphere containing nitrogen. Can be obtained. The main crystal of the present invention is a tetragonal system (orthorhombic system) and belongs to the space group Cmcm. However, depending on the synthesis conditions such as the firing temperature, a crystal having a different crystal system or space group may be mixed. Even in this case, since the change in the light emission characteristics is slight, it can be used as a high-luminance phosphor. In the case where the phosphor of the present invention contains Ca, Y as the L element or F (fluorine) as the Z element, the mixture of the metal compounds further includes a fluoride of L element (for example, calcium fluoride) or oxidation of the L element. (For example, calcium oxide, yttrium oxide) may be included. Such a starting material may be an inorganic compound that generates a liquid phase at a temperature lower than the firing temperature described below.

As the starting material, for example, a mixture of metal compounds is AlN and / or Al ₂ O ₃ , Si ₃ N _4, and an oxide or nitride of A (where A is Mn, Ce, Pr, Nd, And one or more elements selected from Sm, Eu, Tb, Dy, and Yb) may be used. These mixtures are preferable because the raw materials are easily available and excellent in stability. Moreover, since reaction is easy to advance at the time of baking, it is preferable.

  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. When calcination is performed under such conditions, boron or boron nitride components are mixed from the container into the product, but if the amount is small, the light emission characteristics are not deteriorated, so the influence is small. Furthermore, the addition of a small amount of boron nitride may improve the durability of the product, which is preferable in some cases.

  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.

In such a light emitting device, in addition to the phosphor of the present invention, a β sialon green phosphor activated by Eu, an α sialon yellow phosphor activated by Eu, and Sr ₂ Si ₅ N ₈ orange activated by Eu One or more phosphors selected from phosphors, Eu-activated (Ca, Sr) AlSiN ₃ orange phosphors, and Eu-activated CaAlSiN ₃ red phosphors may be further included. As yellow phosphors other than the above, for example, YAG: Ce, (Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu, or the like may be used.

  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 450 nm, and the phosphor of the present invention emits blue to green light, and other phosphors of the present invention include 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.

  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 white 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 white object color is observed, but the color development is good and the phosphor of the present invention does not deteriorate for a long time. 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), an aluminum nitride powder having a specific surface area of 3.3 m ² / g and an oxygen content of 0.82 wt% (E grade manufactured by Tokuyama Corporation), and a specific surface area of 13.2 m ² / g Aluminum oxide powder (Taimicron manufactured by Daimei Chemical Industries), europium oxide (Eu ₂ O ₃ ; purity 99.9%, manufactured by Shin-Etsu Chemical Co., Ltd.), cerium oxide (CeO ₂ ; purity 99.9%, Shin-Etsu) and chemical Co., Ltd.), europium nitride (EuN; and by the metal europium heated for 10 hours at 800 ° C. in an ammonia gas stream, the metal ones obtained by nitriding), terbium oxide _{(Tb 4 O} 7; The degree of 99.9% by Shin-Etsu Chemical Co., Ltd.), ytterbium oxide; made of _(Yb 2 _{O 3} 99.9% purity manufactured by Shin-Etsu Chemical Co.,), manganese carbonate (MnCO _3; 99.9% purity ( High purity chemical laboratory) and calcium fluoride (CaF ₂ ; purity 99.9%, high purity chemical laboratory).

[Phosphor Examples; Examples 1 to 36]
According to the design composition shown in Table 2 and Table 3, the raw materials were weighed so as to have the mixed composition (mass ratio) shown in Table 4. The design parameters were in the range of m = 2 to 40 (n = 4 to 42) and x = 1 to 3. Depending on the type of raw material used, the composition may differ between the design composition in Tables 2 and 3 and the mixed composition in Table 4. In this case, the mixed composition was determined so that the amount of metal ions matched. The component of the composition deviation is mixed in the product as a second phase, but its amount is small, so that the influence on the performance is small. 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 at 800 ° C. is 99.999% by volume. Nitrogen was introduced to bring 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 2 hours.

Next, the synthesized compound was pulverized using an agate mortar, and powder X-ray diffraction measurement was performed using Cu _Kα rays. As a result, an inorganic crystal represented by M _n X _{n + 1} , that is, a crystal represented by a general formula of Si _x Al _{m + 2−x} O _3−x N _{m + x} (m = n−2, 0 <x ≦ 3, m: integer) It was confirmed that the phase was the main product phase. Moreover, it was confirmed from the measurement of EDS that the composite contains Eu, Si, Al, N, and O. That is, it was confirmed that the composite was an inorganic compound in which Eu as a luminescent ion was dissolved in a crystal of Si _x Al _{m + 2-x} O _3-x N _{m + x} (0 <x ≦ 3, m: integer).

  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 green. The emission spectrum and excitation spectrum of this powder were measured using a fluorescence spectrophotometer. Table 6 shows the peak wavelength of the excitation spectrum and the peak wavelength of the emission spectrum. These inorganic compounds can be excited by ultraviolet rays of 300 nm to 380 nm, violet or blue light of 380 nm to 450 nm, and were confirmed to be phosphors emitting blue to green 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 is contained in a trace amount in a synthetic | combination as an impurity 2nd phase.

[Phosphor Example; Example 37]
According to the design composition shown in Table 7 and Table 8, the raw materials were weighed so as to have the mixed composition (mass ratio) shown in Table 9. Design parameters are m = 10 and x = 2.5, and the difference from Examples 1-36 is that calcium fluoride (CaF ₂ ) is added as a flux. Flux is an inorganic compound that generates a liquid phase at a temperature lower than the firing temperature during firing for phosphor synthesis, and when added and fired, the reaction and grain growth are promoted and stable crystals can be obtained. This may improve the emission intensity. The flux, an alkali metal compound (LiCl, NaC1, KCl, LiF , NaF, KF , etc.) it is or alkaline earth metal compound _{(CaF 2, SrF 2, BaF} 2, CaC1 2, SrCl 2, BaCl 2 , etc.) In Example 37, calcium fluoride (CaF ₂ ) was used.

  The weighed raw material powders were mixed for 5 minutes using a silicon nitride sintered body pestle and mortar in the same manner as in Examples 1-36. Thereafter, the mixed powder was put into a crucible made of a boron nitride sintered body. The bulk density of the powder was in the range of 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 at 800 ° C. is 99.999% by volume. Nitrogen was introduced to bring the pressure in the furnace to 1 MPa, the temperature was raised to 500 ° C. per hour at a set temperature of 2000 ° C., and held at that temperature for 2 hours.

Next, the synthesized compound was pulverized using an agate mortar, and powder X-ray diffraction measurement was performed using Cu _Kα rays. As a result, an inorganic crystal represented by M _n X _{n + 1} , that is, a crystal represented by a general formula of Si _x Al _{m + 2−x} O _3−x N _{m + x} (m = n−2, 0 <x ≦ 3, m: integer) It was confirmed that the phase was the main product phase. Moreover, it was confirmed from the measurement of EDS that the composite contains Eu, Si, Al, N, O, Ca, and F. That is, the composite is an inorganic compound in which Eu, which is a luminescent ion, and Ca and F are dissolved in a crystal of Si _x Al _{m + 2-x} O _3-x N _{m + x} (0 <x ≦ 3, m: integer). confirmed.

  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 in the range of 3 to 8 μm.

  As a result of irradiating this powder with a lamp emitting light having a wavelength of 365 nm, it was confirmed that light was emitted from blue to green. The emission spectrum and excitation spectrum of this powder were measured using a fluorescence spectrophotometer. Table 10 shows the peak wavelength of the excitation spectrum and the peak wavelength of the emission spectrum. This inorganic compound can be excited by ultraviolet rays of 300 nm to 380 nm, violet or blue light of 380 nm to 450 nm, and was confirmed to be a phosphor emitting blue to green light.

[Phosphor Examples; Examples 38 to 43]
According to the design composition shown in Table 11 and Table 12, the raw materials were weighed so as to have the mixed composition (mass ratio) shown in Table 13. Unlike Examples 1 to 36, elements other than Eu were used as the activator elements to be luminescent ions. Depending on the type of raw material used, the composition may differ between the design composition in Tables 11 and 12 and the mixed composition in Table 13. In this case, the mixed composition was determined so that the amount of metal ions matched. The component of the composition deviation is mixed in the product as a second phase, but its amount is small, so that the influence on the performance is small. 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 at 800 ° C. is 99.999% by volume. Nitrogen was introduced to bring the pressure in the furnace to 1 MPa, the temperature was raised to 500 ° C. per hour at a set temperature of 2000 ° C., and held at that temperature for 2 hours.

Next, the synthesized compound was pulverized using an agate mortar, and powder X-ray diffraction measurement was performed using Cu _Kα rays. As a result, an inorganic crystal represented by M _n X _{n + 1} , that is, a crystal represented by a general formula of Si _x Al _{m + 2−x} O _3−x N _{m + x} (m = n−2, 0 <x ≦ 3, m: integer) It was confirmed that the phase was the main product phase. Moreover, from the measurement of EDS, it was confirmed that the composite contains Ce, Tb, Yb or Mn, Si, Al, N, O. That is, it was confirmed that the synthesized product was an inorganic compound in which the element A as a luminescent ion was dissolved in a Si _x Al _{m + 2-x} O _3-x N _{m + x} (0 <x ≦ 3, m: integer) 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 in the range of 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 green. Even if Ce, Tb, Yb, or Mn is used as an activator element, these inorganic compounds can be excited by ultraviolet rays of 300 nm to 380 nm, violet or blue light of 380 nm to 450 nm, and emit blue to green light. It was confirmed to be a phosphor.

[Synthesis and Structural Analysis of Crystalline Si _x Al _14-x O _3-x N _{12 + x} (x = 3)]
The inventors of the present application obtained an inorganic crystal represented by M _n X _{n + 1} obtained in Examples 1 to 43 using Si _x Al _{m + 2−x} O _3−x N _{m + x} (m = n−2, 0 <x ≦ Among phosphors based on inorganic crystals represented by the general formula 3), m = 12 (n = 14) Si _x Al _14-x O _3-x N _{12 + x} (0 <x ≦ 3) It has been found that a phosphor having an inorganic crystal as a base exhibits particularly excellent light emission characteristics. _{Hereinafter, Si x Al 14-x O} 3-x N 12 + x (0 <x ≦ 3) will be described in detail the synthesis and structural analysis of the crystals.

A mixed composition of silicon nitride (Si ₃ N ₄ ) and aluminum nitride (AlN) was designed in such a ratio that the cation ratio was Si: Al = 3: 11. These raw material powders were weighed so as to have the above mixed composition and mixed for 5 minutes using a silicon nitride sintered pestle and mortar in a glove box in a nitrogen atmosphere having an oxygen content of 1 ppm. 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 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 at 800 ° C. is 99.999% by volume. Nitrogen was introduced to bring the pressure in the furnace to 1 MPa, and the temperature was raised to 2000 ° C. at 500 ° C. per hour and held at that temperature for 2 hours.

  The synthesized product was observed with an optical microscope, and crystal particles having a size of 4 μm × 8 μm × 34 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 Si, Al, and N elements was confirmed, and the ratio of the number of atoms contained in Si and Al was measured to be 3:11.

  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 oxygen and nitrogen enter at the same atomic position, and when they are averaged as a whole, the composition ratio of the crystal is obtained.

This crystal belongs to a tetragonal system (orthorhombic system) (orthohombic system), belongs to a space group Cmcm, (International Tables for Crystallography No. 63 space group), and lattice constants a, b, c are
a = 0.30722 nm, b = 1.87210 nm, c = 4.14890 nm, angles α = 90 °, β = 90 °, and γ = 90 °. 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. Further, since Al is +3 valence and Si is +4 valence, if the atomic position and the ratio of Al and Si are known, the ratio of O and N occupying the (O, N) position is determined from the condition of electrical neutrality of the crystal. Desired. The composition of this crystal determined from the Si: Al ratio of the measured value of EDS and the single crystal X-ray structure analysis was Si _x Al _14-x O _3-x N _{12 + x} (x = 3). The starting material composition and the crystal composition may be different because the composition other than Si _x Al _14-x O _3-x N _{12 + x} (x = 3) is produced as a small amount of the second phase. Even in this case, since this measurement uses a single crystal, the analysis result shows a pure Si _x Al _14-x O _3-x N _{12 + x} (x = 3) structure.

When the similar composition was examined, the Si _x Al _14-x O _3-x N _{12 + x} (x = 3) crystal was partially replaced with Al while maintaining the crystal structure, and a part of Al was replaced with Si. And a part or all of O can be replaced by N, and a part of N can be replaced by O. These substituted crystals are Si _x Al _14-x O _3-x N _{12 + x} (x = 3) It was confirmed to be one composition of a crystal group having the same crystal structure. Further, the electrical neutrality condition _can be described as a composition represented by _{Si x Al 14-x O 3} -x N 12 + x (0 <x ≦ 3).

Si _x Al _14-x O _3−x N _{12 + x} can also be described as a composition represented by Si _x Al _{m + 2−x} O _3−x N _{m + x} (0 <x ≦ 3, m = 12). These structures including Si _x Al _14-x O _3-x N _{12 + x} (0 <x ≦ 3) crystal in which m = 12 are Al ₂ O ₃ (AlN) _m converted to SiAlON, and Al → Si , O → N substitution corresponds to 1: 1 +1 and −1 in the valence increase / decrease, so that both changes can be represented by the same variable. As the number of m increases, the AlN-like phase increases and the longest lattice axis (c-axis in general notation) extends. The remaining two axes (a-axis and b-axis) take almost the same 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. In the future, powder X diffraction measurement of the synthesized product will be performed, and if the measured powder pattern is the same as that in FIG. 2, it can be determined that the crystal Si _x Al _14-x O _3-x N _{12 + x in} FIG. . Furthermore, the crystal constants obtained by powder X-ray diffractometry and the crystals shown in Table 1 are those in which the lattice constant or the like is changed while maintaining the crystal structure as a Si _x Al _14-x O _3-x N _{12 + x-} based crystal. Since the powder X-ray pattern can be calculated from the structure data by calculation, it can be determined that a Si _x Al _14-x O _3-x N _{12 + x-} based crystal is generated by comparing with the calculated pattern.

[Phosphor Examples; Examples 44 to 53]
According to the design composition shown in Table 14 and Table 15, the raw materials were weighed so as to have the mixed composition (mass ratio) shown in Table 16. The design parameters were m = 12 (n = 14), and x was in the range of 0.5-3. Depending on the type of raw material used, the composition may differ between the design composition of Table 14 and Table 15 and the mixed composition of Table 16. In this case, the mixture composition was determined so that the amount of metal ions matched. The component of the composition deviation is mixed in the product as a second phase, but its amount is small, so that the influence on the performance is small. 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 at 800 ° C. is 99.999% by volume. Nitrogen was introduced to bring the pressure in the furnace to 1 MPa, the temperature was raised to 500 ° C. per hour to the set temperature shown in Table 17, and the temperature was maintained for 2 hours.

Next, the synthesized compound was pulverized using an agate mortar, and powder X-ray diffraction measurement was performed using Cu _Kα rays. As a result, it was confirmed that a crystal phase having the same crystal structure as the crystal of Si _x Al _14-x O _3-x N _{12 + x} (x = 3) was generated. Moreover, it was confirmed from the measurement of EDS that the composite contains Eu, Si, Al, N, and O. That is, it was confirmed that the synthesized product was an inorganic compound in which Eu, which is a luminescent ion, was dissolved in a Si _x Al _14-x O _3-x N _{12 + x} 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 green. The emission spectrum and excitation spectrum of this powder were measured using a fluorescence spectrophotometer. Table 18 shows the peak wavelength of the excitation spectrum and the peak wavelength of the emission spectrum. These inorganic compounds can be excited by ultraviolet rays of 300 nm to 380 nm, violet or blue light of 380 nm to 450 nm, and were confirmed to be phosphors emitting blue to green 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 is contained in a trace amount in a synthetic | combination as an impurity 2nd phase.

FIG. 3 is a graph showing a powder X-ray diffraction result of the phosphor synthesized in Example 51.
4 is a diagram showing an excitation spectrum and an emission spectrum of the phosphor synthesized in Example 51. FIG.

The powder X-ray diffraction result (FIG. 3) of the synthesized phosphor shows good agreement with the result of structural analysis (FIG. 2). In Example 51, Si _x Al _14-x O _3-x N _{12 + x} (x = 3) It was confirmed that the crystal and the X-ray diffraction pattern were the same, and the crystal having the same crystal structure as the Si _x Al _14-x O _3-x N _{12 + x} (x = 3) crystal was the main component. In Example 51, it was found that excitation was most efficient at 328 nm, and the emission spectrum when excited at 328 nm showed emission having a peak at 479 nm. Moreover, it confirmed that the luminescent color of the fluorescent substance of Example 51 was (0.164, 0.271) in the CIE1931 chromaticity coordinate.

[Examples of Light Emitting Device and Image Display Device; Examples 54 to 57]
Next, a light emitting device using the phosphor of the present invention will be described.

[Example 54]
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. 5 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 ultraviolet 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 ultraviolet 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 phosphor prepared in Example 51 and the CaAlSiN ₃ : Eu red phosphor at a mass ratio of 4: 1 was mixed with an epoxy resin at a concentration of 25% by weight, and this was used as 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 = 0.45, y = 0.39, which was a light bulb color.

  Further, when a bullet-type white light-emitting diode lamp was similarly manufactured using a purple light-emitting diode element having an emission peak at 405 nm, almost the same result was obtained.

[Example 55]
FIG. 6 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 board mounting shown in FIG. 6 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 mounted and fixed at one end of the lead wire so as to be in 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 α-SiAlON: Eu yellow phosphor and the phosphor (17) obtained by mixing the phosphor prepared in Example 51 in a mass ratio of 7: 3 is the vicinity of the light emitting diode element. Has been implemented. 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). The addition ratio of the phosphor was substantially the same as in Example 54, and the achieved chromaticity was x = 0.33 and y = 0.33, which was white.

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

[Example 56]
FIG. 7 is a schematic view showing an image display device (plasma display panel) according to the present invention.

The blue phosphor (31), the green phosphor (β-sialon: Eu ²⁺ ) (32) and the red phosphor (CaAlSiN ₃ : Eu ²⁺ ) (33) of Example 51 of the present invention are formed on the glass substrate (44). The electrode (37, 38, 39) and the dielectric layer (41) are applied to the inner surface of each cell (34, 35, 36). 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 57]
FIG. 8 is a schematic view showing an image display device (field emission display panel) according to the present invention.

  The blue phosphor (56) of Example 51 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 blue 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 reality, a display that can produce a variety of colors is constructed by arranging a number of red and green cells in addition to blue. 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). Gold thin 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. Gold thin wire.
16, 18. resin.
17. Phosphor.
19. Alumina ceramic substrate.
20. Wall member.
31. Blue phosphor.
32. Green phosphor.
33. Red 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 (25)

An inorganic crystal represented by M _n X _{n + 1} containing at least a metal element M and a non-metal element X (where n is a numerical value in the range of 3 ≦ n ≦ 52, and the metal element M includes at least Al (aluminum) , Si (silicon) and, if necessary, L element (L element is a metal element other than Al and Si), and the non-metallic element X is at least N (nitrogen), and optionally O. (Oxygen) and, if necessary, a Z element (Z element is a nonmetallic element other than N and O), an inorganic crystal having the same crystal structure, or an inorganic crystal that is a solid solution thereof , A element (where A is one or more elements selected from Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, and Yb), and the M _n X inorganic crystals represented by _{n + 1} is, _Si x Al ₁ Inorganic crystals represented by _{-x O 3-x N 12 +} x ( however, 0 <x ≦ 3) a is the phosphor. 2. The phosphor according to claim 1, wherein the inorganic crystal having the same crystal structure is an inorganic crystal represented by (Si, Al) ₁₄ (O, N) ₁₅ . An inorganic crystal represented by Si _x Al _14-x O _3-x N _{12 + x} , an inorganic crystal having the same crystal structure as this, or an inorganic crystal of these solid solutions is a tetragonal crystal (orthorhombic crystal). Having the symmetry of the space group Cmcm, and the lattice constants a, b, c are
a = 0.30722 ± 0.05 nm
b = 1.87210 ± 0.05 nm
c = 4.14890 ± 0.05 nm
The phosphor according to claim 1, wherein the phosphor has a value in the range.   The phosphor according to claim 1, wherein the x value is 1.5 ≦ x ≦ 3.   The phosphor according to claim 4, wherein the x value is 2 ≦ x ≦ 2.9.   The phosphor according to claim 1, wherein the element A is Eu. The inorganic compound has a composition formula Si _a Al _b O _c N _d A _e Q _f (where a + b + c + d + e + f = 1, and A is Mn, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Yb 1 or 2 or more elements selected from the above, Q is represented by 1 or 2 or more elements selected from elements other than Al, Si, O, N, and A), and parameters a, b, c, d, e, f
0.012 ≦ a ≦ 0.1031
0.378 ≦ b <0.48
0 ≦ c <0.103
0.412 <d <0.516
0.0001 ≤ e ≤ 0.03
0 ≤ f ≤ 0.3
The phosphor according to claim 1, which has a value in a range that satisfies all of the above conditions. The parameters a, b, c, d, e, f are
0.0172 ≦ a ≦ 0.1031
0.378 ≦ b ≦ 0.4639
0 ≦ c ≦ 0.0859
0.4296 ≤ d ≤ 0.5155
0.0001 ≦ e ≦ 0.0196
0 ≤ f ≤ 0.0233
The phosphor according to claim 7, which has a value in a range that satisfies all of the above conditions. The parameters a, b, c, d, e, f are
0.0515 ≤ a ≤ 0.1031
0.378 ≦ b ≦ 0.4296
0 ≤ c ≤ 0.0515
0.4639 ≤ d ≤ 0.5155
0.0001 ≦ e ≦ 0.0196
0 ≤ f ≤ 0.0233
The phosphor according to claim 8, which has a value in a range that satisfies all of the above conditions. The parameters a, b, c, d, e, f are
0.0687 ≤ a ≤ 0.1031
0.378 ≦ b ≦ 0.4124
0 ≦ c ≦ 0.0344
0.4811 ≤ d ≤ 0.5155
0.0004 ≦ e ≦ 0.0196
0 ≤ f ≤ 0.0233
The phosphor according to claim 9, which has a value in a range that satisfies 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 size of 0.1 μm or more and 40 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% by mass or more.   The phosphor according to claim 1, which emits fluorescence having a peak at a wavelength in a range of 460 nm to 500 nm by irradiating an excitation source.   The phosphor according to claim 13, wherein the excitation source is vacuum ultraviolet rays, ultraviolet rays, visible light, electron beams, or X-rays having a wavelength of 100 nm to 420 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 AlN and / or Al ₂ O ₃ , Si ₃ N _4, and an oxide or nitride of A (where A is Mn, Ce, Pr, Nd, Sm, Eu, Tb, The phosphor production method according to claim 15, comprising: one or more elements selected from Dy and Yb.   The method for producing a phosphor according to claim 15, wherein the metal compound in the form of powder or aggregate is baked after being filled in a container in a state where the bulk density is maintained at 40% or less.   A light-emitting device comprising at least a light-emitting body and a phosphor, wherein the phosphor uses at least the phosphor according to claim 1.   The light emitting device according to claim 18, 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 18, wherein the light emitting device is a white light emitting diode, a lighting fixture including a plurality of the 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 450 nm, and mixes blue or green light emitted from the phosphor according to claim 1 with light having a wavelength of 450 nm or more emitted from another phosphor. The light emitting device according to claim 18, which emits white light or light other than white light.   The image display apparatus comprised from an excitation source and fluorescent substance, The said fluorescent substance is an image display apparatus containing the fluorescent substance of Claim 1 at least.   23. The image display device according to claim 22, wherein the image display device is one of a fluorescent display tube (VFD), a field emission display (FED), a plasma display panel (PDP), a cathode ray tube (CRT), or a liquid crystal display (LCD). The image display device described.   A pigment comprising the phosphor according to claim 1.   An ultraviolet absorber comprising the phosphor according to claim 1.