JP2020007434A - Fluophor and light-emitting device using the same - Google Patents

Abstract

To provide a novel fluophor.SOLUTION: There is provided a fluophor obtained by dissolving an element represented by Rin a fluophor host crystal represented by L(G,A)X, in which the L is one or more kinds of element selected from Li, Na, Mg, Ca, Sr, Ba, Sc, Y, La, and Al, the G is one or two elements selected from Si and Ge, the A is one or more element selected from Al, Ga and B, the X is one or more kind of element selected from O, N, F and Cl, excluding a case that X is only N, the R is one or more kind of element selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, and Yb, and α, β, γ and δ are α+β+γ+δ=20, 3.70≤α≤4.30, 4.70≤β≤5.30, 10.70≤γ≤11.30, and 0.00<δ≤0.20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a phosphor, a method for producing the phosphor, and uses of the phosphor.

The fluorescent substance is a fluorescent display tube (VFD (Vacuum-Fluorescent Display)), a field emission display (FED (Field Emission Display) or a SED (Surface-Condition Electron Display Panel (PDP), a plasma display panel (PDP)). , A cathode ray tube (CRT (Cathode-Ray Tube)), a liquid crystal display backlight (Liquid-Crystal Display Backlight), a white light-emitting diode (LED (Light-Emitting Diode)) and the like.
In any of these applications, in order to cause the phosphor to emit light, it is necessary to supply energy for exciting the phosphor to the phosphor. The phosphor is excited by an excitation source having high energy such as vacuum ultraviolet ray, ultraviolet ray, electron beam, and blue light, and emits visible light such as blue light, green light, yellow light, orange light, and red light.

However, there has been a problem that the luminance of the phosphor is easily reduced as a result of being exposed to the excitation source.
Therefore, instead of conventional phosphors such as silicate phosphors, phosphate phosphors, aluminate phosphors, and sulfide phosphors, phosphors with little reduction in luminance even at high energy excitation have been proposed. . Examples of such a phosphor include phosphors based on inorganic crystals containing nitrogen in the crystal structure, such as sialon phosphors, oxynitride phosphors, and nitride phosphors.

The sialon phosphor is manufactured, for example, by a manufacturing process 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 are mixed at a temperature of 1700 ° C. in nitrogen at 1 atm (0.1 MPa). It is manufactured by firing for 1 hour and baking by a hot press method (for example, see Patent Document 1). It has been reported that α sialon activated by Eu ²⁺ ion 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 or the ratio of oxygen and nitrogen while maintaining the crystal structure of α-sialon (for example, Patent Document 2 and Patent Document 2). 3).

As another example of the sialon phosphor, a green phosphor in which Eu ²⁺ is activated in a β-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 (for example, see Patent Document 5). It is also known that activation of Ce ³⁺ to β-sialon results in a blue phosphor (for example, see Patent Document 6).

As examples of the 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 )It has been known. In this phosphor, it is known that, by replacing a part of La with Ca while maintaining the crystal structure, the excitation wavelength becomes longer and the emission wavelength becomes longer.
Further, as another example of the oxynitride phosphor, a blue phosphor in which La is used as a base crystal of La ₃ N ₈ La ₁₁ Si ₈ N ₁₁ O ₄ and activated by Ce (see Patent Document 8) is known. .

As examples of the nitride phosphor, the red phosphor is activated (see Patent Document 9) are known to ^{Eu 2+} and CaAlSiN ₃ as host crystals. Use of this phosphor has the effect of improving the color rendering properties of the white LED. It is reported that a phosphor to which Ce is added as an optically active element is an orange phosphor.

  As described above, the emission color of the phosphor is determined by the combination of the base crystal and the metal ions (activation ions) dissolved in the base crystal. Further, the combination of the host crystal and the activating ions also determines emission characteristics such as an emission spectrum and an excitation spectrum, chemical stability, or thermal stability. Therefore, when the host crystal is different or the activator ion is different, it is regarded as a different phosphor. In addition, materials having the same chemical composition but different crystal structures have different light-emitting characteristics and stability due to different base crystals, and are therefore regarded as different phosphors.

Further, in many phosphors, it is possible to replace the types 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 a YAG crystal emits green light, while a phosphor in which a part of Y is replaced with Gd and a part of Al is replaced with Ga in the YAG crystal emits yellow light. Furthermore, it is known that, in a phosphor obtained by adding Eu to CaAlSiN ₃ , the composition changes while maintaining the crystal structure by partially replacing Ca with Sr, and the emission wavelength is shortened. As described above, the phosphors that have been subjected to element substitution while maintaining the crystal structure are regarded as materials belonging to the same group.

JP-A-2002-363554 JP 2005-8793 A JP 2005-307012 A JP 2005-255895 A International Publication No. 2007/066733 WO 2006/101096 International Publication No. 2005/019376 JP 2005-112922 A JP-A-2006-8721

  As described above, in the development of a new phosphor, it is important to find a host crystal having a new crystal structure, and the metal ion responsible for light emission is activated in such a host crystal to improve the fluorescence characteristics. By expressing it, a novel phosphor can be proposed.

  An object of the present invention is to provide a novel phosphor. Still another object of the present invention is to provide a light emitting element, a light emitting device, and an image display device including the novel phosphor.

  In the present invention, in particular, it has emission characteristics (emission color, excitation characteristic, emission spectrum) different from those of conventional phosphors, and has a high emission intensity even when combined with an LED of 470 nm or less, and has a chemical and thermal effect. It is an object of the present invention to provide a stable inorganic phosphor.

  The present inventors have explored new phosphors and studied in detail the characteristics of the obtained phosphors. As a result, the phosphor host crystal containing a specific element and represented by a specific composition formula has a specific addition. The present inventors have found a novel phosphor in which an active element is dissolved as a solid solution, and have completed the present invention together with a production method thereof.

  Further, it is also possible to provide a light emitting element, a light emitting device, and an image display device each containing the phosphor of the present invention.

(1) That is, the present invention provides a phosphor in which an element represented by R _δ is dissolved in a phosphor host crystal represented by L _α (G, A) _β X _γ ,
L is one or more elements selected from Li, Na, Mg, Ca, Sr, Ba, Sc, Y, La and Al;
G is one or two elements selected from Si and Ge;
A is one or more elements selected from Al, Ga and B;
X is one or more elements selected from O, N, F and Cl (except that X is only N);
R is one or more elements selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Yb;
Α, β, γ, and δ are α + β + γ + δ = 20;
3.70 ≦ α ≦ 4.30,
4.70 ≦ β ≦ 5.30,
10.70 ≦ γ ≦ 11.30,
0.00 <δ ≦ 0.20
Is a phosphor.
In the phosphor composition formula, O, that is, oxygen does not include oxygen up to the phosphor surface. This is similarly interpreted herein.

(2) Further, according to the present invention, in the phosphor host crystal,
L is one or more elements selected from Mg, Ca, Sr and Ba;
G is partially or entirely a Si element;
A is partially or entirely an Al element;
X is one or two types of elements selected from N and O (except that X is only N);
R is preferably one or more elements selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Yb.

(3) In the present invention, the phosphor host crystal may be a crystal belonging to an orthorhombic system and having a space group Pna21 symmetry.

(4) In the present invention, the lattice constants a, b, and c of the phosphor host crystal are:
a = 1.8921 ± 0.05 nm,
b = 0.5412 ± 0.05 nm and c = 0.9705 ± 0.05 nm
Is preferably in the range of
Here, “± 0.05” indicates a permissible range of numerical values. For example, a means that the range is 1.8921−0.05 ≦ a ≦ 1.8921 + 0.05. This is to be interpreted here as well.

(5) Further, in the present invention, the phosphor is represented by the composition formula _{Ca e Si f Al g O h1} N h2 R i,
The composition ratios e, f, g, h1, h2 and i are:
e + f + g + h1 + h2 + i = 20,
3.70 ≦ e ≦ 4.30,
0.00 ≦ f ≦ 5.30,
0.00 ≦ g ≦ 5.30,
10.70 ≦ h1 + h2 ≦ 11.30 (where h1> 0) and 0.00 <i ≦ 0.20
It is preferable that

(6) In the present invention, the composition ratios e, f, g, h1, h2, and i are:
e + i = 4.00 ± 0.30,
f + g = 5.00 ± 0.30,
h1 + h2 = 11.00 ± 0.30 (however, h1> 0)
It is preferable that

(7) In the present invention, the composition ratios f and g are:
0.00 ≦ g / (f + g) ≦ 1.00
It is preferable that

(8) Further, in the present invention, the composition ratios h1 and h2 are:
5/11 ≦ h1 / (h1 + h2) ≦ 10/11
It is preferable that

(9) When the phosphor of the present invention is irradiated with light including a light intensity peak in a wavelength range of 250 nm or more and 500 nm or less, a light intensity peak is emitted in a wavelength range of 430 nm or more and 700 nm or less, preferably 440 nm or more and 700 nm or less. May fluoresce.

(10) Further, when the phosphor of the present invention is irradiated with light having a light intensity peak in the wavelength range of 250 nm to 500 nm, the phosphor of the present invention can emit fluorescence having a light intensity peak in the wavelength range of 510 nm to 530 nm.

(11) In the present invention, the element represented by R preferably contains Eu.

(12) Further, in the present invention, the phosphor is represented by the composition formula _{Ca 4-r Si 4-q} Al 1 + q O 6 + q N 5-q Eu r,
Parameters q and r are
−1.0 <q ≦ 2.0 and 0.0 <r ≦ 0.2
It is preferable that

(13) In the present invention, a raw material containing at least L, a raw material containing G, a raw material containing A, a raw material containing X, and a raw material containing R (where L is Li, One or more elements selected from Na, Mg, Ca, Sr, Ba, Sc, Y, La and Al;
G is one or two elements selected from Si and Ge;
A is one or more elements selected from Al, Ga and B;
R is one or more elements selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Yb;
X is one or more elements selected from O, N, F and Cl (except that X is only N). ) Is mixed with the raw material mixture,
A method for producing a phosphor, comprising firing the raw material mixture in a temperature range of 1000 ° C. to 1500 ° C.

(14) The present invention also provides a light emitting device including the phosphor.

(15) The present invention also provides a light emitting device using the light emitting element.

(16) The present invention also provides an image display device using the light emitting element.

According to the practice of the present invention, a phosphor in which an element represented by R _δ is dissolved in a phosphor matrix crystal represented by L _α (G, A) _β X _γ ,
L is one or more elements selected from Li, Na, Mg, Ca, Sr, Ba, Sc, Y, La and Al;
G is one or two elements selected from Si and Ge;
A is one or more elements selected from Al, Ga and B;
X is one or more elements selected from O, N, F and Cl (except that X is only N);
R is one or more elements selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Yb;
Α, β, γ, and δ are α + β + γ + δ = 20;
3.70 ≦ α ≦ 4.30,
4.70 ≦ β ≦ 5.30,
10.70 ≦ γ ≦ 11.30,
0.00 <δ ≦ 0.20
, A novel phosphor can be obtained.

  The novel phosphor of the present invention emits light of high luminance from blue to yellow green, and is excellent as a green phosphor with a specific composition. The phosphor of the present invention, even when exposed to an excitation source for a long time, does not decrease in luminance. Therefore, it is assumed that the phosphor of the present invention is preferably used for a light-emitting element such as a white light-emitting diode or a phosphor plate. The light-emitting element including the light-emitting element is suitably used for a light-emitting device such as a lighting fixture and a backlight source for liquid crystal, and an image display device such as a VFD, FED, PDP, and CRT. Further, the phosphor of the present invention absorbs ultraviolet rays, and thus is suitable for use as a material for a pigment and an ultraviolet absorber. Further, for example, it is also possible to obtain a molded article such as a fluorescent molded article, a fluorescent sheet or a fluorescent film obtained by further molding the resin composition containing the phosphor of the present invention.

It is a diagram showing the crystal structure of _{Ca 4 Si 4 Al 1 O 6} N 5 crystal. Is a graph illustrating a powder X-ray diffraction using a _{Ca 4 Si 4 Al 1 O 6} N 5 CuKα line calculated from the crystal structure of the crystal. FIG. 3 is a view showing the result of powder X-ray diffraction of the compound synthesized in Example 1. FIG. 3 is a diagram showing an excitation spectrum and an emission spectrum of a compound synthesized in Example 1. 1 is a schematic view of a board-mounted LED device according to the present invention.

  Hereinafter, embodiments of the present invention will be described. However, the embodiments described below show typical embodiments of the present technology, and the scope of the present technology is not construed as being narrow.

<1. Phosphor>
Phosphor host crystal relating phosphor of the present invention, L α _(G, A) is represented by _beta X _gamma, phosphor of the present invention, the elements represented by R _[delta] is in the phosphor host crystal was dissolved Things.
And the L of the phosphor host crystal is one or more elements selected from Li, Na, Mg, Ca, Sr, Ba, Sc, Y, La and Al;
G is one or two elements selected from Si and Ge;
A is one or more elements selected from Al, Ga and B;
X is one or more elements selected from O, N, F and Cl (except that X is only N);
R is one or more elements selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Yb;
Α, β, γ, and δ are α + β + γ + δ = 20;
3.70 ≦ α ≦ 4.30,
4.70 ≦ β ≦ 5.30,
10.70 ≦ γ ≦ 11.30,
0.00 <δ ≦ 0.20
It is.

In the process up to the completion of the present invention, the present inventors, from a raw material containing Ca element, Si element, Al element and O element, the composition formula is Ca ₄ Si ₄ Al ₁ O ₆ N ₅ The synthesized material was synthesized and studied intensively. As a result of the crystal structure analysis of the synthesized material, Ca ₄ Si ₄ Al ₁ O ₆ N ₅ was used as a unit. It was confirmed that the compound was a single compound having no crystal structure. _{Further, Ca 4 Si 4 Al 1 O 6} N 5 not crystals only a portion or even all elements are replaced by other specific _elements, the same crystal as _{Ca 4 Si 4 Al 1 O 6} N 5 crystal After confirming that the structure can be maintained, these are put together to form a crystal having a composition formula of L _α (G, A) _β X _γ represented by symbols L, G, A, and X (where L is One or more elements selected from Li, Na, Mg, Ca, Sr, Ba, Sc, Y, La and Al, and G is one or two elements selected from Si and Ge Wherein A is one or more elements selected from Al, Ga and B, and X is one or more elements selected from O, N, F and Cl (provided that , X is only N)).

Furthermore said L _alpha (G, A) to the _beta X _gamma crystal element (except represented by R _[delta], R is, Mn, Cr, Ti, Ce , Pr, Nd, Sm, Eu, Tb, Dy, Ho And one or more elements selected from Yb and Yb. In addition, α, β, γ, and δ are α + β + γ + δ = 20, and δ satisfies 0.00 <δ ≦ 0.20.) Also has the same crystal structure as the L _α (G, A) _β X _γ crystal, and shows a fluorescent light emission. Therefore, the composition formula is expressed as L _α (G, A) _β element crystal represented by X _gamma, which can be a novel phosphor host crystal, i.e., a composition formula, the L α _{(G, a)} β phosphor host crystal represented by X _gamma, represented by R _[delta] Have found a novel phosphor in which is dissolved as a solid solution, and have completed the present invention.

Table 1 shows the results of X-ray crystal structure analysis on Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal, which triggered the completion of the present invention.

  In Table 1, lattice constants a, b, and c indicate the lengths of the axes of the unit cell, and α, β, and γ indicate the angles between the axes of the unit cell. Atomic coordinates indicate the position of each atom in the unit cell as a value between 0 and 1 using the unit cell as a unit. In this crystal, each atom of Ca, Si, Al, O, and N was present, and an analysis result was obtained in which Ca was present in four types of the same site (Ca (1) to Ca (4)). In addition, analysis results were obtained in which Si and Al exist in the same five seats (Si, Al (1) to Si, Al (5)). In addition, analysis results were obtained in which O and N existed in the same 11 seats (O, N (1) to O, N (11)).

FIG. 1 shows a crystal structure of Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal.
In FIG. 1, 1 is an O and N atom. 2 is a Ca atom. 3 is a SiO ₄ and AlO ₄ tetrahedron. That is, the Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal belongs to the orthorhombic system and belongs to the Pna2 ₁ space group (space group of the International Tables for Crystalgraphy No. 33). In this crystal, an element represented by R, for example, Eu or the like is a so-called activation element responsible for light emission, and is taken into the crystal in a form that partially replaces Ca.

The above results are not known as publicly known technical information before the phosphor of the present invention was found, that is, the phosphor host crystal whose composition formula is represented by L _α (G, A) _β X _γ The phosphor of the present invention in which R _δ is dissolved in a solid solution is a novel phosphor.

Further composition formula, or replaced by _{L α (G, A) β} X γ represented by the crystal, _{i.e., Ca 4 Si 4 Al 1 O} 6 N 5 other elements some or all of the crystal element, later In a crystal in which an activating element such as Eu is further dissolved as described above, the lattice constant of the Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal shown in Table 1 varies, but the basic crystal structure and atomic Does not change so much as to break the chemical bond between the skeletal atoms, and its crystal structure does not change.

That is, not only the aforementioned "the _{Ca 4 Si 4 Al 1 O 6} N 5 crystal, even its part or all of the elements are substituted with other specific _{elements, Ca 4 Si 4 Al 1 O 6} N 5 crystalline and may remain at the same crystalline structure ", composition formula, L α _(G, a) relates to crystal represented by _beta X _gamma, the results of X-ray diffraction or neutron diffraction, in Pna2 ₁ space group The lattice constants obtained by Rietveld analysis and the lengths of the chemical bonds of Al-N and Si-N (distance between adjacent atoms) calculated from the atomic coordinates are Ca ₄ Si ₄ Al ₁ O ₆ shown in Table 1. The requirement is to satisfy ± 5% of the length of the chemical bond calculated from the lattice constant and the atomic coordinates of the N ₅ crystal. At this time, it has been experimentally confirmed that when the length of the chemical bond exceeds ± 5%, the chemical bond is broken to form another crystal.

In the L _α (G, A) _β X _γ crystal according to the present invention, for example, in the Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal shown in FIG. However, the element represented by the symbol of G and A can be placed in the seat where Si and Al enter, and the element represented by the symbol of X can enter in the seat where O and N enter. By this regularity, while maintaining the crystal structure of Ca ₄ Si ₄ Al ₁ O ₆ N ₅ , the ratio of the number of atoms of G and A to 5, and X to the total number of 11 is 11 can do. Further, the element represented by R can enter a seat where Ca enters. However, it is desirable that the sum of the positive charges represented by the elements represented by L, G, A, and R and the total of the minus charges represented by X cancel each other out, and the electrical neutrality of the entire crystal is maintained. .

FIG. 2 shows a peak pattern of powder X-ray diffraction using CuKα rays, calculated from the crystal structure of Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal based on the numerical values shown in Table 1.

Note that the following method can be preferably used as a simple method for determining whether or not a crystal whose crystal structure is unknown has the same crystal structure as the Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal. . That is, when the measured X-ray diffraction peak position (2θ) and the diffraction peak position shown in FIG. This is a method of determining that the crystal structure is the same, that is, the crystal structure of an unknown crystal structure is the same as the Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal. The main peak may be determined based on about ten diffraction intensities. In the present invention, this determination method was used in Examples.

As described above, the phosphor of the present invention is a phosphor in which the element represented by R _δ is dissolved in the phosphor host crystal represented by L _α (G, A) _β X _γ. ,
L is one or more elements selected from Mg, Ca, Sr and Ba;
G is part or all of a Si element;
A is partially or entirely an Al element;
X may be one or two elements selected from N and O (except that X is only N).

Here, in the production of a conventional phosphor, when a raw material containing an N element, that is, a nitride is used, a phosphor containing a small amount of an O element derived from the raw material has been manufactured. However, in the present invention, as will be described later, a phosphor is manufactured using a raw material containing an O element, that is, an oxide. This manufacturing method is not limited to manufacturing a phosphor using only an oxide, and a nitride may be used. However, a phosphor is not manufactured using only a nitride. Therefore, all of X of the phosphor host crystal represented by L _α (G, A) _β X _γ is not replaced by the N element.

In the phosphor of the present invention, the phosphor host crystal is, belongs to the orthorhombic system, or may be a crystal having a space group Pna2 ₁ symmetry.

In the phosphor of the present invention, the lattice constants a, b, and c of the phosphor host crystal are
a = 1.8921 ± 0.05 nm,
b = 0.5412 ± 0.05 nm and c = 0.9705 ± 0.05 nm
Is preferably in the range of

Furthermore the phosphor of the present invention are represented by the composition formula _{Ca e Si f Al g O h1} N h2 R i,
The composition ratios e, f, g, h1, h2 and i are:
e + f + g + h1 + h2 + i = 20,
3.70 ≦ e ≦ 4.30,
0.00 ≦ f ≦ 5.30,
0.00 ≦ g ≦ 5.30,
10.70 ≦ h1 + h2 ≦ 11.30 (where h1> 0) and 0.00 <i ≦ 0.20
It is preferable that
With such a composition ratio, it is considered that the phosphor host crystal is stably formed, and a phosphor with higher emission intensity can be obtained.

The composition ratio e is a parameter indicating the composition ratio of Ca or the like. When the composition ratio is 3.70 or more and 4.30 or less, the crystal structure does not become unstable, and a decrease in emission intensity can be suppressed.
The composition ratio f is a parameter indicating a composition ratio of Si or the like. When the composition ratio is 0.00 or more and 5.30 or less, the crystal structure does not become unstable, and a decrease in emission intensity can be suppressed.
The composition ratio g is a parameter indicating the composition ratio of Al or the like. If the composition ratio is 0.00 or more and 5.30 or less, the crystal structure becomes stable and the emission intensity is maintained.
The composition ratios h1 and h2 are parameters representing the composition ratio of O and N. If h1 + h2 is 10.70 or more and 11.30 or less (h1> 0), the crystal structure of the phosphor becomes unstable. In addition, a decrease in emission intensity can be suppressed.
The composition ratio i is a parameter representing the composition ratio of the activating element R such as Eu. If i exceeds 0.00, it is possible to suppress a decrease in luminance due to a shortage of the activating element. If i is 0.20 or less, it is sufficiently possible to maintain the structure of the phosphor host crystal. If it exceeds 0.20, the structure of the phosphor base crystal may be unstable. Further, it is preferable that i be 0.20 or less, because it is possible to suppress a decrease in emission intensity due to a concentration quenching phenomenon caused by an interaction between the activating elements.

Further, the composition ratios e, f, g, h1, and h2 are:
e + i = 4.00 ± 0.30,
f + g = 5.00 ± 0.30,
h1 + h2 = 11.00 ± 0.30 (however, h1> 0)
It is preferable that With such a composition ratio, it is considered that the phosphor host crystal is stably formed, and a phosphor with higher emission intensity can be obtained.

Further, the composition ratios f and g are
0.00 ≦ g / (f + g) ≦ 1.00
Is preferable because it is considered that the crystal structure is stable and the emission intensity is particularly high.

Further, the composition ratios h1 and h2 are
5/11 ≦ h1 / (h1 + h2) ≦ 10/11
Is preferable because the phosphor is considered to have a more stable crystal structure and a high emission intensity.

  Further, when the phosphor of the present invention is irradiated with light having a light intensity peak in a wavelength range of 250 nm or more and 500 nm or less, for example, a fluorescent material having a light intensity peak in a wavelength range of 430 nm or more and 700 nm or less, preferably 440 nm or more and 700 nm or less. Can be issued.

  Particularly preferably, when light having a light intensity peak in the wavelength range of 250 nm or more and 500 nm or less is irradiated, fluorescence having a light intensity peak in the wavelength range of 510 nm or more and 530 nm or less can be emitted.

  In the phosphor of the present invention, R (where R is one or two selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Yb) The above elements are phosphors in which a solid solution is formed as the activating element, but Eu can be preferably selected as the activating element R. The phosphor containing Eu as the activator R is a phosphor having a high emission intensity in the present invention, and emits blue to red fluorescent light having a specific composition of 430 nm to 700 nm, preferably 440 nm to 700 nm. A phosphor is obtained.

Particularly preferably, the phosphor of the present invention are represented by a composition formula composition formula _{Ca 4-r Si 4-q} Al 1 + q O 6 + q N 5-q Eu r,
Parameters q and r are
−1.0 <q ≦ 2.0 and 0.0 <r ≦ 0.2
It is also a phosphor that can be expressed as The phosphor represented by the above composition formula is obtained by changing the Eu / Ca ratio, the Si / Al ratio, and the N / O ratio by appropriately changing the values of the q and r parameters while maintaining a stable crystal structure. In addition, the excitation peak wavelength and the emission peak wavelength of the phosphor can be continuously changed. The range of q is preferably -0.5 ≦ q ≦ 1.0 because the crystal becomes stable.

  When the emission peak wavelength of the phosphor changes, the color emitted when the excitation light is irradiated is the value of (x, y) on the CIE1931 chromaticity coordinates, for example, 0 ≦ x ≦ 0.4, 0 ≦ y ≦ 0.9. Such a phosphor is preferably used, for example, as a phosphor emitting blue to yellow-green light for a white LED.

  Note that the phosphor of the present invention is a phosphor that emits light by absorbing the energy of, for example, vacuum ultraviolet light, ultraviolet light, visible light, or radiation having an excitation source having a wavelength of 100 nm or more and 500 nm or less. Examples of the radiation include, but are not particularly limited to, X-rays, gamma rays, α-rays, β-rays, electron beams, and neutron rays. By using these excitation sources, the phosphor of the present invention can emit light efficiently. The phosphor of the present invention has excellent heat resistance because it does not deteriorate even when exposed to high temperatures, and also has the advantage of being excellent in long-term stability under an oxidizing atmosphere and a moisture environment, and has a durability. To provide excellent products.

  The phosphor of the present invention is preferably a single crystal particle of the phosphor of the present invention, a particle in which the single crystal of the phosphor of the present invention is aggregated, or a mixture thereof. It is desirable that the phosphor of the present invention has as high a purity as possible.However, for substances other than the phosphor of the present invention, for example, impurities other than the phosphor of the present invention which are inevitably contained, the emission of the phosphor is not impaired. As long as it is included.

  For example, Fe, Co, and Ni impurity elements contained in the raw material and the firing container may reduce the emission intensity of the phosphor. In this case, by setting the total of these impurity elements in the phosphor to 500 ppm or less, the influence on the decrease in emission intensity is reduced.

  When the phosphor of the present invention is manufactured, a compound having a crystalline phase or an amorphous phase (also referred to as an auxiliary phase) other than the phosphor of the present invention may be simultaneously formed. The subphase does not always have the same composition as the phosphor of the present invention. It is preferable that the phosphor of the present invention does not include a subphase as much as possible, but may include a subphase as long as the light emission of the phosphor is not impaired.

That is, as one of the embodiments of the present invention, the phosphor of the present invention uses a crystal represented by the above-mentioned L _α (G, A) _β X _γ as a phosphor base crystal, and an R _δ activation element. Is a mixture of a compound in which is dissolved in an ionic state and another crystal phase such as a subphase different from the compound, and there is a phosphor having a compound content of 20% by mass or more.

The above-described embodiment may be used when desired characteristics cannot be obtained with a single crystal phosphor represented by L _α (G, A) _β X _γ . The content of the phosphor host crystal represented by L _α (G, A) _β X _γ may be adjusted according to the desired characteristics. However, when the content is 20% by mass or more, the emission intensity becomes sufficient. From such a viewpoint, it is preferable that, in the phosphor of the present invention, 20% by mass or more is a main component of the above-described compound. Such a phosphor can emit fluorescent light having a peak in a wavelength range of 430 nm to 700 nm, preferably 440 nm to 700 nm by irradiating the excitation source.

  The shape of the phosphor of the present invention is not particularly limited, but when used as dispersed particles, for example, single crystal particles having an average particle diameter of 0.1 μm or more and 30 μm or less, or particles in which single crystals are aggregated It is preferred that When the particle diameter is controlled within this range, the luminous efficiency is high, and the operability when mounting on an LED is good. The average particle diameter is a volume-based median diameter calculated from a particle size distribution (cumulative distribution) measured using a particle size distribution measuring apparatus based on a laser diffraction / scattering method defined in JIS Z8825 (2013). (D50). Further, the phosphor of the present invention can be sintered again to be used as a non-particle shape. In particular, a plate-shaped sintered body containing a phosphor is generally called a phosphor plate, and can be preferably used, for example, as a light emitting member of a light emitting element.

<2. Manufacturing method of phosphor>
The method for producing the phosphor of the present invention is also one of the embodiments of the present invention,
A raw material containing at least L, a raw material containing G, a raw material containing A, a raw material containing X, and a raw material containing R (where L is Li, Na, Mg, Ca, Sr , Ba, Sc, Y, La and Al are one or more elements selected from the group consisting of:
G is one or two elements selected from Si and Ge;
A is one or more elements selected from Al, Ga and B;
R is one or more elements selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Yb;
X is one or more elements selected from O, N, F and Cl (except that X is only N). ) Is mixed with the raw material mixture,
A method for producing a phosphor, comprising firing the raw material mixture in a temperature range from 1000 ° C. to 1500 ° C. When the raw material is a compound, one compound may contain a plurality of elements among L, G, A, X and R, and the raw material may be a single substance, that is, a substance composed of a single element. Good.

  The raw material containing L is a metal, oxide, carbonate, hydroxide containing one or more elements selected from Li, Na, Mg, Ca, Sr, Ba, Sc, Y, La and Al. , Oxynitride, nitride, hydride, fluoride, and chloride, or a mixture of two or more kinds, and specifically, an oxide is preferably used.

  The raw material containing G is a metal, oxide, carbonate, hydroxide, oxynitride, nitride, hydride, fluoride, and chloride containing one or two elements selected from Si and Ge. Or a mixture of two or more thereof, and specifically, an oxide is preferably used.

  The raw material containing A is a metal, oxide, carbonate, hydroxide, oxynitride, nitride, hydride, fluoride containing one or more elements selected from Al, Ga and B. And a mixture of two or more selected from chlorides and chlorides. Specifically, oxides are preferably used.

  Raw materials containing R include metals, oxides, nitrides containing one or more elements selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Yb. Or a mixture of two or more kinds selected from a compound, a fluoride, and a chloride. Specifically, europium oxide is preferably used. Each raw material is preferably in a powder form.

  The raw material containing X is a single substance selected from oxides, nitrides, fluorides, and chlorides or a mixture of two or more kinds. The oxide, nitride, fluoride and chloride may contain the above L, G, A or R. However, nitride is a part of the raw material, but not the whole.

For example, when manufacturing a Ca ₄ Si ₄ Al ₁ O ₆ N ₅ phosphor activated with Eu, an oxide, nitride, or fluoride of europium and an oxide, nitride, or fluoride of calcium are used. It is preferable to form a raw material mixture using a compound containing silicon oxide, nitride or fluoride and aluminum oxide, nitride or fluoride. In addition, calcium and silicon, calcium and aluminum, aluminum and silicon, composite metals consisting of calcium, silicon and aluminum, oxides, carbonates, hydroxides, oxynitrides, nitrides, hydrides, fluorides, or chlorides Or the like may be used as a starting material. In particular, it is more preferable to use europium oxide, calcium oxide, silicon oxide, and silicon aluminum oxide.

  In the method for producing the phosphor of the present invention, during firing for synthesizing the phosphor of the present invention, a compound containing an element other than the element constituting the phosphor, which generates a liquid phase at a temperature equal to or lower than the firing temperature, is added. May be fired. Since the compound that generates such a liquid phase functions as a flux and functions to promote the synthesis reaction and the grain growth of the phosphor, a stable crystal may be obtained and the emission intensity of the phosphor may be improved. .

  Compounds that generate a liquid phase at a temperature equal to or lower than the firing temperature include one or two selected from Mg, Ca, Sr, Ba, Li, Na, Al, Ge, Ga, B, Sc, Y, La, and Si. There are one or more mixtures of fluorides, chlorides, iodides, bromides and phosphates of more than one element. Since these compounds have different melting points, it is better to use them depending on the synthesis temperature. In the present invention, these compounds that form a liquid phase are also included in the raw material for convenience.

In order to produce the phosphor in the form of a powder or an aggregate, each raw material is preferably a powder.
Further, since the synthesis reaction of the phosphor takes place from the contact portion between the raw material powders as a starting point, it is preferable that the average particle diameter of the raw material powder is 500 μm or less, because the contact portion of the raw material powder increases and the reactivity is improved.

  In the method for producing a phosphor of the present invention, there is no particular limitation on a method of mixing each raw material to form a raw material mixture, and a known mixing method is used. That is, in addition to the dry mixing method, the wet mixing in an inert solvent that does not substantially react with each raw material, followed by the method of removing the solvent can be used. As the mixing device, a V-type mixer, a rocking mixer, a ball mill, a vibration mill or the like is preferably used.

  In the firing of the raw material mixture, various heat-resistant materials may be used as the firing container for holding the raw material mixture. For example, a container made of boron nitride such as a sintered body of boron nitride, A container, a carbon container such as a carbon sintered body, a container made of molybdenum, tungsten, or tantalum metal can be used.

  In the method for producing a phosphor of the present invention, the firing temperature of the raw material mixture is preferably from 1000 ° C to 1500 ° C, more preferably from 1200 ° C to 1400 ° C. If the calcination temperature is lower than 1000 ° C., the decarburization reaction does not proceed when using a carbonate raw material, which is not preferable. On the other hand, if the firing temperature exceeds 1500 ° C., the phosphor of the present invention is decomposed, and the fluorescent characteristics are deteriorated. The firing time varies depending on the firing temperature, but is usually about 1 to 10 hours. The temporal pattern of heating, temperature holding, and cooling in firing and the number of repetitions thereof are not particularly limited, and raw materials may be added as needed during firing.

In the method for producing a phosphor of the present invention, control of the valence of Eu is important in order to obtain sufficient emission intensity, and firing in a reducing environment in which Eu can be reduced from Eu ³⁺ to Eu ²⁺ is performed. preferable. For example, in a reducing environment, an atmosphere in which an inert gas such as nitrogen or argon gas is filled in a graphite resistance heating type electric furnace in which furnace materials such as a heat insulating material and a heater are made of carbon, and a heat insulating material and a heater are used. atmosphere and the furnace material is sealed by diluting H ₂ gas and H ₂ gas with an inert gas such as nitrogen or argon gas to the all-metal furnace which is made of molybdenum or tungsten, corrosion on the furnace material such as insulation and heater An atmosphere in which NH ₃ gas or NH ₃ gas is diluted and sealed with an inert gas such as nitrogen or argon gas in a furnace provided with heat resistance, or a furnace provided with corrosion resistance in a furnace material such as a heat insulating material or a heater. ₄ is a gas or CH ₄ gas, such as atmosphere enclosing diluted with an inert gas such as nitrogen or argon gas can be cited, as the atmosphere in order to obtain a sufficient emission intensity was encapsulated H ₂ gas and NH ₃ gas囲気 is preferable.

The pressure range during the firing is preferably a pressurized atmosphere as much as possible, since thermal decomposition of the raw material mixture and the phosphor as a product is suppressed. Specifically, the pressure is preferably 0.1 MPa (atmospheric pressure) or more. Further, the oxygen partial pressure in the atmosphere during firing is preferably 0.0001% or less in order to suppress oxidation of each raw material or phosphor during firing.

  The phosphor obtained by firing, the phosphor powder obtained by pulverizing the phosphor, and the phosphor powder after particle size adjustment are heat-treated (also referred to as annealing treatment) at a temperature of 600 ° C. or more and 1300 ° C. or less. Can also. By this operation, the defect contained in the phosphor and the damage due to the pulverization may be recovered. Defects and damage may cause a decrease in light emission intensity, and the heat treatment may restore the light emission intensity.

  Further, the phosphor after firing or after the annealing treatment may be washed with a solvent or an acidic or basic solution. By this operation, the content of the compound that forms a liquid phase at a temperature equal to or lower than the firing temperature and the subphase can be reduced. As a result, the emission intensity of the phosphor may increase.

  The finally obtained phosphor of the present invention preferably has an average particle diameter of 50 nm or more and 200 μm or less in terms of volume-based median diameter (d50) because of its high emission intensity. The volume-based average particle diameter can be measured by a laser diffraction / scattering method defined in JIS Z8825. By using one or more methods selected from pulverization, classification and acid treatment, it is preferable to adjust the average particle diameter of the phosphor powder synthesized by firing to 50 nm or more and 200 μm or less. More preferably, the particle size is adjusted to 50 nm or more and 50 μm or less.

  As described above, the phosphor of the present invention can have a wide excitation range from radiation and ultraviolet light to visible light, and can emit light from blue to red, and in particular, exhibits blue to red light having a specific composition of 450 nm or more and 650 nm or less. In addition, the emission wavelength and emission peak width can be adjusted. Due to such light emission characteristics, the phosphor of the present invention is further useful as a material for forming the phosphor of the present invention or a light emitting device using a phosphor plate containing the phosphor of the present invention. Further, a lighting device and an image display device using the light emitting element, and the phosphor of the present invention are suitable for a pigment and an ultraviolet absorber. The phosphor of the present invention is used not only by itself, for example, a composition obtained by mixing various materials including the phosphor of the present invention with a resin, etc., further molded fluorescent molded articles, such as a fluorescent sheet or a fluorescent film. A molded article can be provided. Note that the phosphor of the present invention is excellent in heat resistance because it does not deteriorate even when exposed to high temperatures, and also has the advantage of being excellent in long-term stability in an oxidizing atmosphere and a moisture environment. It can provide products with excellent properties.

<3. Light-emitting device>
Although the phosphor of the present invention can be used for various applications, a light-emitting element including the phosphor of the present invention is also one aspect of the present invention. The shape of the phosphor of the present invention included in the light emitting element may be a particle shape or a shape obtained by sintering the particle phosphor again. A phosphor obtained by sintering a particulate phosphor again, particularly in a flat plate shape, may be referred to as a phosphor plate. Further, the light emitting element referred to here generally includes a phosphor and an excitation source of the phosphor.

  When the phosphor of the present invention is used to form a light-emitting element generally called a light-emitting diode (also referred to as an LED), the phosphor of the present invention is dispersed in, for example, resin or glass (collectively referred to as a solid medium). In general, a configuration in which the phosphor-containing composition is arranged so that the phosphor is irradiated with excitation light from an excitation source is preferably employed. At this time, the phosphor-containing composition can also contain a phosphor other than the phosphor of the present invention.

  The resin that can be used as a solid medium of the phosphor-containing composition shows a liquid property before molding or when dispersing the phosphor, and does not cause an undesired reaction or the like as the phosphor or light-emitting element of the present invention. Any resin can be selected according to the purpose and the like. Examples of the resin include an addition reaction type silicone resin, a condensation reaction type silicone resin, a modified silicone resin, an epoxy resin, a polyvinyl resin, a polyethylene resin, a polypropylene resin, and a polyester resin. One of these resins may be used alone, or two or more thereof may be used in an optional combination and ratio. When the resin is a thermosetting resin, by curing the resin, a phosphor-containing composition in which the phosphor of the present invention is dispersed is obtained.

  The usage ratio of the solid medium is not particularly limited and may be appropriately adjusted depending on the application and the like. Generally, the mass ratio of the solid medium to the phosphor of the present invention is usually 3% by mass or more, and is preferably Is in the range of 5% by mass or more, usually 30% by mass or less, preferably 15% by mass or less.

  Further, the phosphor-containing composition of the present invention may contain other components in addition to the phosphor of the present invention and the solid medium, depending on the use and the like. Other components include a diffusing agent, a thickener, a bulking agent, an interference agent, and the like. Specific examples include silica-based fine powder such as Aerosil and alumina.

As the phosphor other than the phosphor of the present invention, beta-sialon green phosphor activated by Eu, alpha-sialon yellow phosphor activated by Eu, Sr ₂ Si ₅ N ₈ orange fluorescence activated by Eu And one or more phosphors selected from Eu-activated (Ca, Sr) AlSiN ₃ orange phosphor and Eu-activated CaAlSiN ₃ red phosphor. As the yellow phosphor other than the above, for example, YAG: Ce, (Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu may be used.

As one embodiment of the light-emitting device of the present invention, in addition to the phosphor of the present invention, a green phosphor which 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 further included. Examples of such a green phosphor include β-sialon: Eu, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, and (Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu. is there.

Further, as one embodiment 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 further included. . Examples of such a yellow phosphor include YAG: Ce, α-sialon: Eu, CaAlSiN ₃ : Ce, La ₃ Si ₆ N ₁₁ : Ce.

Further, as one of the embodiments of the light emitting device of the present invention, in addition to the phosphor of the present invention, a red phosphor which emits light having a peak wavelength of 600 nm or more and 700 nm or less by a light emitting material or a light source is further included. it can. Examples of such a 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.

  When the phosphor of the present invention is included in the light emitting element of the present invention in the form of a phosphor plate, the phosphor plate is formed by molding the phosphor of the present invention in the form of particles into a desired shape, and then heating and baking. It is tied. However, the phosphor plate of the present invention may contain a phosphor other than the phosphor of the present invention and other components. Examples of the other components include glass as a medium, a binder resin, a dispersant, and a sintering aid. The additives of the binder resin, dispersant, and sintering aid are not particularly limited, but a substance known in the art, which is generally decomposed and removed simultaneously with heat sintering, can be preferably used.

  The average particle diameter of the phosphor particles used in manufacturing the phosphor plate is not particularly limited, but the amount of the binder resin imparting moldability is adjusted according to the specific surface area of the particles of the phosphor material. For example, those having an average particle diameter of 0.1 μm or more and 30 μm or less can be preferably used.

  The phosphor plate can be manufactured by a known method. For example, to the phosphor of the present invention in the form of a powder, a binder resin, a dispersant, an additive such as a sintering aid are added, a dispersion medium is further added and wet-mixed, and the obtained slurry is adjusted in viscosity. Then, the phosphor sheet of the present invention can be obtained while decomposing and removing the additive by heating and firing the sheet to form a sheet or a disk. The heating temperature, time, and firing atmosphere may be appropriately changed to known conditions depending on the material used. In addition, a method of adding a glass powder having a melting point lower than that of the phosphor of the present invention, molding the mixture, followed by firing to produce a phosphor plate is also effective.

  The excitation source included in the light emitting device of the present invention is, for example, a light source that emits excitation energy by exciting the phosphor of the present invention or another type of phosphor to emit light. The phosphor of the present invention emits light even when irradiated with vacuum ultraviolet rays of 100 to 190 nm, ultraviolet rays of 190 to 380 nm, an electron beam, and the like. Preferred examples of the excitation source include a blue semiconductor light emitting device. The phosphor of the present invention also emits light by the light from the excitation source, and functions as a light emitting element. Note that the light-emitting element of the present invention does not need to be a single element, and may be an integrated element in which a plurality of light-emitting elements are combined.

  As one mode of the light-emitting element of the present invention, a light-emitting body or a light-emitting light source emits ultraviolet or visible light having a peak wavelength of 300 to 500 nm, preferably 300 to 470 nm, and blue light to green light emitted by the phosphor of the present invention (for example, There is a light emitting element which emits white light or light other than white light by mixing light having a wavelength of 430 nm or more, preferably 440 nm to 530 nm) with light having a wavelength of 430 nm or more, preferably 440 nm or more emitted by another phosphor of the present invention. .

  The above-described embodiment of the light emitting element is an exemplification, and in addition to the phosphor of the present invention, a blue phosphor, a green phosphor, a yellow phosphor, or a red phosphor is appropriately combined to have a desired color. It goes without saying that white light can be achieved.

Still further, as one of the embodiments of the light emitting element of the present invention, when a light emitting body or a light emitting light source uses an LED which emits light having a wavelength of 280 to 500 nm, the light emitting efficiency is high. Can be.
The light from the excitation source to be used is not particularly limited to monochromatic light, but may be polychromatic light.

  FIG. 5 schematically shows a light emitting device (surface mounted LED) according to the present invention.

  A surface-mounted white light emitting diode lamp (11) was manufactured. Two lead wires (12, 13) are fixed to a white alumina ceramic substrate (19) having a high visible light reflectance, and one end of each of these wires is located substantially at the center of the substrate, and the other end is externally connected. The electrodes are soldered when mounted on an electric board. One of the lead wires (12) has a blue light emitting diode element (14) having a light emission peak wavelength of 450 nm placed and fixed at one end thereof so as to be located at the center of the substrate. The lower electrode of the blue light emitting diode element (14) and the lower lead wire are electrically connected by a conductive paste, and the upper electrode and another lead wire (13) are formed of a gold wire bonding wire ( 15).

  A mixture of the first resin (16) and the green phosphor and the red phosphor (17) produced in Example 1 is mounted near the light emitting diode element. The first resin in which the phosphor is dispersed is transparent and covers the entire blue light emitting diode element (14). A wall member (20) having a shape with a hole at the center is fixed on the ceramic substrate. The center of the wall member (20) is a hole for accommodating the resin (16) in which the blue light emitting diode element (14) and the phosphor (17) are dispersed, and the portion facing the center has a slope. Has become. This slope is a reflection surface for extracting light forward, and the curved shape of the slope is determined in consideration of the light reflection direction. Further, at least the surface constituting the reflection surface is a surface having white or metallic luster and having high visible light reflectance. In the light emitting device, the wall member (20) was formed 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, in which the first resin (14) in which the blue light emitting diode element (14) and the phosphor (17) are dispersed is used. A transparent second resin (18) is filled so as to seal all of 16). In the light emitting element, the same epoxy resin can be used for the first resin (16) and the second resin (18). The light emitting element emits white light.

<4. Light-emitting device>
Further, a light-emitting device including the light-emitting element of the present invention is also one aspect of the present invention. Specific examples of the light emitting device include a lighting device, a backlight for a liquid crystal panel, various display devices, and the like.

<5. Image Display>
Further, an image display device including the light emitting element of the present invention is also one aspect of the present invention. Specific examples of the image display device include a fluorescent display tube (VFD), a field emission display (FED), a plasma display panel (PDP), a cathode ray tube (CRT), and a liquid crystal display (LCD).

<6. Pigment>
The phosphor of the present invention can be used, for example, as a constituent material of a pigment by utilizing its function. That is, when the phosphor of the present invention is illuminated with sunlight, a fluorescent lamp, or the like, a white object color is observed. However, the color development is good, and the phosphor of the present invention does not deteriorate over a long period of time. Can be suitably used, for example, for inorganic pigments. For this reason, when used as a pigment to be added to paints, inks, paints, glazes, and plastic products, it is possible to maintain good white for a long time.

<7. UV absorber>
The phosphor of the present invention can be used, for example, as a constituent material of an ultraviolet absorber by utilizing its function, instead of using it alone. That is, for example, when the ultraviolet absorbent containing the phosphor of the present invention is kneaded into a plastic product or a paint, or applied to the surface of a plastic product, they can be effectively protected from ultraviolet degradation.

<8. Phosphor sheet>
The phosphor of the present invention is mixed with, for example, a resin to form a composition, and a molded phosphor, a phosphor film, and a phosphor sheet obtained by molding the composition are also preferable examples of the phosphor of the present invention. For example, the phosphor sheet of the present invention referred to herein is a sheet containing the phosphor of the present invention so as to be uniformly dispersed in a medium. The material of the medium is not particularly limited, but is preferably transparent, and is a material capable of maintaining its form in a sheet shape, for example, a resin. Specifically, silicone resin, epoxy resin, polyarylate resin, PET-modified polyarylate resin, polycarbonate resin, cyclic olefin, polyethylene terephthalate resin, polymethyl methacrylate resin, polypropylene resin, modified acrylic, polystyrene resin and acrylonitrile / styrene And copolymer resins. In the phosphor sheet of the present invention, a silicone resin or an epoxy resin is preferably used in terms of transparency. In consideration of heat resistance, a silicone resin is preferably used.

  Additives can be added to the phosphor sheet of the present invention as needed. For example, if necessary at the time of film formation, a leveling agent at the time of film formation, a dispersant for accelerating the dispersion of the phosphor, and an adhesion auxiliary agent such as a silane coupling agent as a sheet surface modifier may be added. . Further, inorganic particles such as silicone fine particles may be added as a phosphor precipitation inhibitor.

  The thickness of the phosphor sheet of the present invention is not particularly limited, but is preferably determined from the phosphor content and desired optical characteristics. From the viewpoint of the phosphor content, workability, optical characteristics, and heat resistance, the film thickness is, for example, 10 μm or more and 3 mm or less, and more preferably 50 μm or more and 1 mm or less.

  The method for producing the phosphor sheet of the present invention is not particularly limited, and a known method can be used. The phosphor sheet of the present invention only needs to contain the phosphor of the present invention, and may be a single-layer sheet or a multilayer sheet, and the entire sheet does not need to be uniform. It is also possible to provide a base material layer on one or both sides of the sheet, or on the inside. The material of the base layer is also not particularly limited, and for example, a known metal, film, glass, ceramic, paper, or the like can be used. Specifically, metal plates and foils of aluminum (including aluminum alloy), zinc, copper, iron, etc., cellulose acetate, polyethylene terephthalate (PET), polyethylene, polyester, polyamide, polyimide, polyphenylene sulfide, polystyrene, polypropylene, polycarbonate Polyvinyl acetal, plastic film such as aramid, paper laminated with the plastic, or paper coated with the plastic, paper laminated or vapor-deposited with the metal, plastic film laminated or vapor-deposited with the metal, etc. No. In the case where the base material is a metal plate, the surface may be plated with chromium or nickel or ceramic. In particular, it is preferable that the substrate is in the form of a film that is flexible and has high strength. Therefore, for example, a resin film is preferable, and specific examples include a PET film and a polyimide film.

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

(Reference example)
L α _(G, A) fluorescence represented by _{Ca 4 Si 4 Al 1 O 6} N 5 except crystal represented by _beta X _gamma, or the L α _{(G, A)} β represented by X _gamma crystalline Ca ₄ Si ₄ Al ₁ O ₆ N ₅ was synthesized as a representative of the phosphor base crystal, which is a crystal having the same crystal structure as the base host crystal, and this was used as a reference example. Next, the crystal structure of the obtained Ca ₄ Si ₄ Al ₁ O ₆ N ₅ of the reference example was analyzed, and it was first confirmed that this was a novel substance without any precedent. This was used as a reference for comparison with the crystal structure of the phosphor host crystal of each phosphor synthesized in Examples 1 and 2.

<Raw material>
As raw materials for Ca ₄ Si ₄ Al ₁ O ₆ N ₅ of the reference example, silicon nitride (SN-E10 grade manufactured by Ube Industries, Ltd.), aluminum nitride (E grade manufactured by Tokuyama Corporation), and oxidation were used. Aluminum (Taimicron manufactured by Daimei Chemical Co., Ltd.), silicon oxide (manufactured by High Purity Chemical), calcium carbonate (manufactured by High Purity Chemical), calcium oxide (manufactured by High Purity Chemical), and europium oxide (manufactured by Shin-Etsu Chemical) And cerium oxide (manufactured by Shin-Etsu Chemical Co., Ltd.).

Calcium carbonate (CaCO ₃ ), silicon nitride (Si ₃ N ₄ ), silicon oxide (SiO ₂ ), aluminum nitride (AlN), aluminum oxide (Al ₂ O ₃ ) having a cation ratio of Ca: Si: Al = 4: 4 The mixed composition was designed at such a ratio as to be 1: 1. These raw material powders were weighed so as to have the above-mentioned mixed composition, and were mixed for 10 minutes using a pestle and a mortar made of a silicon nitride sintered body. Next, the obtained mixed powder was put into a crucible made of a boron nitride sintered body.

The crucible containing the mixed powder was set in a graphite resistance heating type electric furnace. The firing procedure of the mixed powder was as follows. First, the baking atmosphere is evacuated to a pressure of 1 × 10 ⁻¹ Pa or less by a diffusion pump, heated from room temperature to 200 ° C. at a rate of 5 ° C./min. The pressure in the furnace was set to 0.03 MPa, the temperature was raised to 900 ° C. at a rate of 5 ° C./min, and from 900 ° C. to 1400 ° C. at a rate of 10 ° C./min, and maintained at that temperature for 4 hours.

  The composite was observed with an optical microscope, and crystal particles having a size of 10 μm × 19 μm × 13 μm were collected from the composite. 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), the particles were analyzed for the elements contained in the crystal particles. Analysis was carried out. As a result, the presence of the elements Ca, Si, Al, O, and N was confirmed, and the ratio of the number of atoms contained in Ca, Si, and Al was measured to be 4: 4: 1.

  Next, the crystal particles were fixed to the tip of the glass fiber with an organic adhesive. This was subjected to X-ray diffraction measurement using a single crystal X-ray diffractometer (SMART APEXII Ultra manufactured by Bruker AXS) equipped with a rotating anti-cathode of MoKα radiation at an output of an X-ray source of 50 kV and 50 mA. . As a result, it was confirmed that the crystal grains were single crystals.

  The crystal structure was determined from the X-ray diffraction measurement results using single crystal structure analysis software (APEX2 manufactured by Bruker AXS). The obtained crystal structure data is shown in Table 1, and the crystal structure is shown in FIG. Table 1 describes the crystal system, space group, lattice constant, type of atom, and atom position. Using this data, the shape, size, and arrangement of atoms in the unit cell are determined. be able to. Note that Si and Al enter at the same atomic position and oxygen and nitrogen enter at the same atomic position at the same atomic position, and when they are averaged as a whole, the composition ratio of the crystal is obtained.

The crystals belong to the orthorhombic (orthorhombic), space group Pna2 _1, belongs to the (International Tables for 33 th space group of Crystallography), the lattice constants a, b, c and the angle the angle alpha, beta, gamma is , A = 1.8921 nm, respectively,
b = 0.5412 nm,
c = 0.9705 nm,
α = 90 degrees,
β = 90 degrees,
γ = 90 degrees.

Atomic positions were as shown in Table 1 above. Si and Al exist at the same atomic position at a certain ratio determined by the composition, and O and N exist at the same atomic position at a certain ratio determined by the composition. In addition, oxygen and nitrogen can enter the seat where X enters, but since Ca is +2 valence, Si is +4 valence, and Al is +3 valence, the atomic position and the ratio of Ca, Si and Al can be determined. For example, the ratio between O and N occupying the (O, N) position can be determined from the condition of the crystal being electrically neutral. The composition of this crystal determined from the Ca: Si: Al ratio of the EDS measurement value and the crystal structure data was Ca ₄ Si ₄ Al ₁ O ₆ N ₅ .
The difference between the starting material composition and the crystal composition is due to the fact that a composition other than Ca ₄ Si ₄ Al ₁ O ₆ N ₅ was produced as a small amount of the second phase, but the present measurement uses a single crystal. Therefore, the analysis result indicates a pure Ca ₄ Si ₄ Al ₁ O ₆ N ₅ structure.

Examination of the similar composition revealed that Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystals can partially or entirely replace Ca with Mg while maintaining the crystal structure. That is, the crystal of A ₄ Si ₄ Al ₁ O ₆ N ₅ (A is one or two or a mixture of Mg and Ca) has the same crystal structure as the Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal. have. Further, a part of Si can be replaced with Al, a part of Al can be replaced with Si, and a part of N can be replaced with oxygen. This crystal is the same crystal as Ca ₄ Si ₄ Al ₁ O ₆ N _5. It was confirmed that the composition was one of the inorganic crystals having a structure. In addition, under the condition of electric neutrality, these inorganic crystals are represented by a composition formula: Ca4 _{-rSi4 -qAl1 + qO6 + qN5 -} qEur _.
(However, -1.0 <q ≦ 2.0 and 0.0 <r ≦ 0.2 in the composition formula)
Can also be described.

The crystal structure data confirmed that this crystal was a novel substance that had not been reported so far. A powder X-ray diffraction pattern was calculated from the crystal structure data.
FIG. 2 shows powder X-ray diffraction using CuKα rays calculated from the crystal structure of Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal.

In the future, powder X-ray diffraction measurement of the synthesized product will be performed. If the measured powder X-ray diffraction pattern is the same as that of FIG. 2, it is determined that the Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal of FIG. 1 has been generated. it can.
The Ca ₄ Si ₄ Al ₁ O ₆ N ₅ system crystal whose lattice constant and the like were changed while maintaining the crystal structure was the crystal lattice data obtained by powder X-ray diffraction measurement and the crystal structure data shown in Table 1. From this, the powder X-ray diffraction pattern can be calculated. Therefore, by comparing the calculated powder X-ray diffraction pattern with the measured powder X-ray diffraction pattern, it can be determined that Ca ₄ Si ₄ Al ₁ O ₆ N ₅ -based crystals are generated.

(Example 1-18 and Comparative Example 1)
According to the design compositions (atomic ratios) in Examples and Comparative Examples shown in Table 2, the raw material powders were weighed so as to have the raw material mixture compositions (mass ratios) in Table 3.

The weighed raw material powder was mixed for 10 minutes using a pestle made of a silicon nitride sintered body and a mortar. Thereafter, the mixed powder was put into a crucible made of a boron nitride sintered body.

The crucible containing the mixed powder was set in a graphite resistance heating type electric furnace. The firing procedure of the mixed powder was as follows. First, the baking atmosphere is evacuated to a pressure of 1 × 10 ⁻¹ Pa or less by a diffusion pump, heated from room temperature to 200 ° C. at a rate of 5 ° C./min. The pressure in the furnace was set to 0.03 MPa, the temperature was raised to 900 ° C. at a rate of 5 ° C./min, and from 900 ° C. to 1400 ° C. at a rate of 10 ° C./min, and maintained at that temperature for 4 hours. (Firing conditions in Table 5).

Next, the synthesized product was pulverized using an agate mortar, and powder X-ray diffraction measurement was performed using Cu Kα radiation.
FIG. 3 shows the result of powder X-ray diffraction of the compound of Example 1. Table 6 shows main product phases in Examples and Comparative Examples.
Furthermore, EDS measurement confirmed that the composite contained a rare earth element, an alkaline earth metal, Si, Al, O, and N.

The powder X-ray diffraction pattern of the composite of FIG. 3 shows a good agreement with the X-ray diffraction pattern of Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal by the structural analysis shown in FIG. 2, and Ca ₄ Si ₄ Al ₁ O ₆ it was confirmed crystal having a N ₅ crystal and the same crystal structure as a main component.
For example, 2θ = 34.28 degrees, 37.02 degrees, 33.08 degrees, 24.98 degrees, 38.34 degrees, 28.28 degrees, 50.48 degrees, 59.48 degrees, 17.02 in FIG. 4, the peak at 64.98 degrees is 2θ = 34.38 degrees, 37.14 degrees, 33.18 degrees, 25.06 degrees, 38.46 degrees, 28.34 degrees, 50.62 degrees in FIG. Although the peaks at 59.52, 17.12, and 65.12 degrees are partially reversed from the peaks of intensity, they almost correspond to each other, indicating good agreement.
Here, the angle error of 2θ was estimated to be ± 1 degree. Furthermore, EDS measurement confirmed that the composite of Example 1 contained Ca, Eu, Si, Al, O, and N. Further, it was confirmed that the ratio of Ca: Si: Al was 4: 4: 1.

From the above, the composite of Example 1 was an inorganic compound in which Eu was dissolved in Ca ₄ (Si, Al) ₅ (O, N) ₁₁ (specifically, Ca ₄ Si ₄ Al ₁ O ₆ N ₅ ) crystal. It was confirmed that there was.
Although not shown, similar X-ray diffraction patterns were obtained in other examples. The results obtained by associating the X-ray diffraction patterns of the other examples with the main peaks of FIG. 2 for ten main peaks were the same.

Further, as shown in Table 6 above, in the composite of the example of the present invention, the phase having the same crystal structure as the Ca ₄ Si ₄ Al ₁ O ₆ N ₅ crystal was 20% by mass or more as a main generated phase. It was confirmed that it was contained. The difference between the mixed raw material composition and the chemical composition of the synthesized product suggests that the synthesized product contains a trace amount of the impurity second phase.

From the above, it was confirmed that the synthesized product of the example of the present invention contains, as a main component, an inorganic compound in which the activating ion R such as Eu or Ce is dissolved in Ca ₄ Si ₄ Al ₁ O ₆ N ₅ system crystal. Was.

  After firing, the obtained synthetic product (fired body) was roughly pulverized, then pulverized by hand using a crucible made of a silicon nitride sintered body and a mortar, and passed through a 30 μm mesh sieve. When the particle size distribution was measured, the average particle size was 10 to 15 μm.

  As a result of irradiating these powders with a lamp that emits light having a wavelength of 365 nm, it was confirmed that light was emitted from blue to yellow-green. The emission spectrum and excitation spectrum of this powder were measured using a fluorescence spectrophotometer. FIG. 5 shows the results. Table 7 shows the peak wavelength of the excitation spectrum and the peak wavelength of the emission spectrum.

  FIG. 4 is a diagram showing an excitation spectrum and an emission spectrum of the compound synthesized in Example 1.

According to FIG. 4, it was found that the compound of Example 1 could be most efficiently excited at 310 nm, and the emission spectrum when excited at 310 nm emitted green light having a peak at 516 nm.
Further, it was confirmed that the emission color of the compound of Example 1 was in the range of 0 ≦ x ≦ 0.4 and 0 ≦ y ≦ 0.9 in CIE1931 chromaticity coordinates.

  According to Table 7, the composite of the present invention can be excited by ultraviolet light of 300 nm to 380 nm, violet or blue light of 380 nm to 450 nm, and is a phosphor that emits blue to yellow-green light. confirmed.

As described above, the synthesized product of the example of the present invention contains, as a main component, an inorganic compound in which an activating ion R such as Eu or Ce is dissolved in Ca ₄ Si ₄ Al ₁ O ₆ N ₅ system crystal. Was found to be a phosphor.

Further, according to Tables 3 and 7, it can be seen that a phosphor that emits blue to yellow-green light can be obtained by controlling to a specific composition.
For example, as shown in the composites of Examples 1 to 17, the A element is Ca, the B element is Si, the C element is Al, and the X element is N or a combination of N and O. A phosphor containing an inorganic compound in which Eu is dissolved as a solid element in the crystal emits green light having a peak in a wavelength range of 490 nm to 550 nm, and more preferably in a wavelength range of 510 nm to 530 nm. As shown in the composition of Example 18, the element A is Ca, the element B is Si, the element C is Al, and the element X is N or a combination of N and O. The phosphor containing an inorganic compound in which Ce forms a solid solution emits blue light having a peak in a wavelength range of 440 nm to 500 nm, more preferably a wavelength range of 440 nm to 460 nm.

  In addition, it is considered that a part where the composition of the mixed raw material is different from the chemical composition of the composite is present in a trace amount in the composite as the impurity second phase.

  Although not shown, it was confirmed that the composites obtained in Examples 1 to 18 had a white object color and were excellent in coloring. It has been found that the inorganic compound, which is a synthetic product of the present invention, can be used as a pigment or a fluorescent pigment because it exhibits a white object color when irradiated with sunlight or illumination such as a fluorescent lamp.

1. O, N atoms2. 2. Ca atom AlO ₄ , SiO ₄ tetrahedron (Al, Si center)
DESCRIPTION OF SYMBOLS 11 Surface mount type white light emitting diode lamps 12, 13 Lead wire 14 Blue light emitting diode element 15 Bonding wire 16 First resin 17 Phosphor 18 Second resin 19 Alumina ceramic substrate 20 Wall member

Claims (16)

A phosphor in which an element represented by R _δ is dissolved in a phosphor matrix crystal represented by L _α (G, A) _β X _γ ;
L is one or more elements selected from Li, Na, Mg, Ca, Sr, Ba, Sc, Y, La and Al;
G is one or two elements selected from Si and Ge;
A is one or more elements selected from Al, Ga and B;
X is one or more elements selected from O, N, F and Cl (except that X is only N);
R is one or more elements selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Yb;
Α, β, γ, and δ are α + β + γ + δ = 20;
3.70 ≦ α ≦ 4.30,
4.70 ≦ β ≦ 5.30,
10.70 ≦ γ ≦ 11.30,
0.00 <δ ≦ 0.20
Phosphor. In the phosphor host crystal,
L is one or more elements selected from Mg, Ca, Sr and Ba;
G is partially or entirely a Si element;
A is partially or entirely an Al element;
X is one or two types of elements selected from N and O (except that X is only N);
R is one or more elements selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Yb.
The phosphor according to claim 1. The phosphor according to claim 1, wherein the phosphor host crystal is a crystal belonging to an orthorhombic system and having a space group Pna2 ₁ symmetry. The lattice constants a, b and c of the phosphor host crystal are
a = 1.8921 ± 0.05 nm,
b = 0.5412 ± 0.05 nm and c = 0.9705 ± 0.05 nm
4. The phosphor according to claim 3, which has a value in the range of: The phosphor is represented by the composition formula _{Ca e Si f Al g O h1} N h2 R i,
The composition ratios e, f, g, h1, h2 and i are:
e + f + g + h1 + h2 + i = 20,
3.70 ≦ e ≦ 4.30,
0.00 ≦ f ≦ 5.30,
0.00 ≦ g ≦ 5.30,
10.70 ≦ h1 + h2 ≦ 11.30 (where h1> 0) and 0.00 <i ≦ 0.20
The phosphor according to any one of claims 1 to 4, wherein The composition ratios e, f, g, h1, h2 and i are:
e + i = 4.00 ± 0.30,
f + g = 5.00 ± 0.30,
h1 + h2 = 11.00 ± 0.30 (however, h1> 0)
The phosphor according to claim 5, which is: The composition ratios f and g are:
0.00 ≦ g / (f + g) ≦ 1.00
The phosphor according to claim 5, wherein The composition ratios h1 and h2 are:
5/11 ≦ h1 / (h1 + h2) ≦ 10/11
The phosphor according to any one of claims 5 to 7, wherein   The phosphor according to any one of claims 1 to 8, wherein, when irradiated with light having a light intensity peak in a wavelength range of 250 nm or more and 500 nm or less, a fluorescent light having a light intensity peak in a wavelength range of 430 nm or more and 700 nm or less is emitted.   The phosphor according to any one of claims 1 to 9, wherein, when irradiated with light including a light intensity peak in a wavelength range of 250 nm or more and 500 nm or less, a fluorescent light having a light intensity peak in a wavelength range of 510 nm or more and 530 nm or less is emitted. .   The phosphor according to any one of claims 1 to 10, wherein the element represented by R includes Eu. The phosphor is represented by the composition formula _{Ca 4-r Si 4-q} Al 1 + q O 6 + q N 5-q Eu r,
Parameters q and r are
−1.0 <q ≦ 2.0 and 0.0 <r ≦ 0.2
The phosphor according to any one of claims 1 to 11, wherein It is a manufacturing method of the phosphor according to any one of claims 1 to 12,
A raw material containing at least L, a raw material containing G, a raw material containing A, a raw material containing X, and a raw material containing R (where L is Li, Na, Mg, Ca, Sr , Ba, Sc, Y, La and Al are one or more elements selected from the group consisting of:
G is one or two elements selected from Si and Ge;
A is one or more elements selected from Al, Ga and B;
R is one or more elements selected from Mn, Cr, Ti, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Yb;
X is one or more elements selected from O, N, F and Cl (except that X is only N). ) Is mixed with the raw material mixture,
A production method, comprising firing the raw material mixture in a temperature range from 1000 ° C to 1500 ° C.   A light emitting device comprising the phosphor according to claim 1.   A light-emitting device using the light-emitting element according to claim 14.   An image display device using the light emitting device according to claim 14.