JP2009094231A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device that uses near-ultraviolet LED as an excitation source, excels in color rendering properties, and shows practical luminous efficiency. <P>SOLUTION: The light-emitting device has a primary light emitter and a secondary light emitter that emits visible light through irradiation of the light from the primary light emitter. The primary light emitter has its luminescence peak in the wavelength range of 300 nm to 420 nm, while the secondary light emitter includes a red phospher satisfying the formula [1] below, a green phospher having a luminescence peak in the wavelength range of 510 nm to 545 nm, and a blue luminescence peak in the wavelength range of 420 nm to 470 nm. The formula [1] is I<SB>570</SB>/I<SB>650</SB>≥0.3 (where I<SB>570</SB>and I<SB>650</SB>are luminescence intensities at 570 nm and 650 nm when the red phospher is excited using light with a peak wavelength of 395 nm). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a light emitting device that includes a first light emitter and a second light emitter that emits visible light when irradiated with light from the first light emitter. The present invention relates to a light emitting device using a UV LED and using a combination of a blue phosphor, a green phosphor, and a red phosphor having specific light emission characteristics as a second light emitter, thereby improving color rendering.

White light-emitting diodes (hereinafter sometimes referred to as “white LEDs” or “white light-emitting devices”) have attracted attention because of their low power consumption and long life.
White LED
(1) A combination of a light emitting diode (hereinafter sometimes referred to as “blue LED”) that emits light in a blue region as an excitation source (first light emitter), and a red phosphor and a green phosphor
(2) Obtained by a combination of a light emitting diode that emits light in the near ultraviolet region as an excitation source (hereinafter sometimes referred to as “near ultraviolet LED”), a blue phosphor, a red phosphor, and a green phosphor. Can do.
Among these, a white LED using a near ultraviolet LED as an excitation source is expected as a light source for a next-generation illumination device or image display device.

On the other hand, it is a nitride or oxynitride phosphor containing a divalent alkaline earth metal element and a divalent to tetravalent rare earth metal element, and is the following [1] and / or [2] A characteristic nitride or oxynitride phosphor is known (Patent Document 1).
[1] The alkaline earth metal element is substituted with an element and / or a vacancy having a lower valence than the alkaline earth metal element.
[2] The rare earth metal element is substituted with a lower valent element and / or a vacancy than the rare earth metal element.

The phosphor is preferably a phosphor represented by the following formula, and the emission spectrum of the phosphor under excitation at 455 nm and 465 nm is described in Patent Document 1, but excited by light in the near ultraviolet region. No detailed study has been made on the light emission characteristics of the case and the phosphors to be combined when producing a white light emitting device.
(1-a-b) (Ln ′ _p M ^{II ′} _1-p M ^{III ′} M ^{IV ′} N ₃ ) · a (M ^{IV ′} _{(3n + 2) / 4} N _n O) · b (AM ^{IV ′} ₂ N ₃ )
(In the above formula, Ln ′ is at least one metal element selected from the group consisting of lanthanoids, Mn and Ti, and M ^{II ′} is one type selected from the group consisting of divalent metal elements other than the Ln ′ element. Or two or more elements, M ^{III ′} is one or more elements selected from the group consisting of trivalent metal elements, and M ^{IV ′} is selected from the group consisting of tetravalent metal elements. One or more elements, A is one or more monovalent metal elements selected from the group consisting of Li, Na, and K, and p is a number satisfying 0 <p ≦ 0.2 A, b and n are numbers satisfying 0 ≦ a, 0 ≦ b, a + b> 0, 0 ≦ n, and 0.002 ≦ (3n + 2) a / 4 ≦ 0.9.)
WO2006 / 126567

  White light-emitting devices using near-ultraviolet LEDs as excitation sources are expected as light sources for next-generation lighting devices and image display devices, but sufficient characteristics are still not obtained in terms of their light emission efficiency, especially color rendering properties. However, there is a need for improvement in luminous properties such as luminous efficiency and color rendering properties for practical use.

  An object of the present invention is to provide a light-emitting device that uses a near-ultraviolet LED as an excitation source, has excellent color rendering properties, and exhibits practical light-emitting efficiency.

As a result of intensive studies to solve the above problems, the present inventors have found that a near-ultraviolet LED as an excitation source (first light emitter), a blue phosphor and a green phosphor as second emitters, and the following formula: It has been found that when a red phosphor satisfying [1] is used in combination, a light emitting device having excellent color rendering properties can be obtained.
The present invention has been achieved based on such knowledge, and the gist thereof is as follows.

(1) A first light emitter and a second light emitter that emits visible light by irradiation of light from the first light emitter,
The first light emitter has a light emission peak in a wavelength range of 300 nm or more and 420 nm or less;
The second phosphor is one or more of red phosphors satisfying the following formula [1], and one or more of green phosphors having an emission peak in the wavelength range of 510 nm or more and 545 nm or less; And a blue phosphor having a light emission peak in a wavelength range of 420 nm or more and 470 nm or less.
I ₅₇₀ / I ₆₅₀ ≧ 0.3 ... [1]
(In the above formula [1],
I ₅₇₀ represents the emission intensity at 570 nm when the red phosphor is excited with light having a peak wavelength of 395 nm,
I ₆₅₀ represents the emission intensity at 650 nm when the red phosphor is excited with light having a peak wavelength of 395 nm. )

(2) The light-emitting device according to (1), wherein the red phosphor further satisfies the following formula [2].
S _L / S _R ≧ 1.56 ... [2]
(In the above equation [2],
S _L represents the total area on the short wavelength side of the emission peak wavelength of the emission spectrum measured by exciting the red phosphor with light having a peak wavelength of 395 nm,
S _R represents the total area on the longer wavelength side of the emission peak wavelength of the emission spectrum measured by exciting the red phosphor with light having a peak wavelength of 395 nm. )

(3) The green phosphor is a phosphor having an oxide or oxynitride containing Si containing Eu as an activator as a base, and a half-value width of the emission peak of 45 nm to 70 nm.
The light emitting device according to (1) or (2), wherein the blue phosphor is a phosphor having an emission peak half width of 45 nm to 70 nm.

(4) The green phosphor is (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, Mn, β- (Si, Al) ₁₂ (O , N) ₁₆ : Eu, and (Ca, Sr, Ba) Si ₂ N ₂ O ₂ : Eu contains at least one selected from the group consisting of Eu,
The light emission according to any one of (1) to (3), wherein the blue phosphor contains one or more selected from the group consisting of (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu apparatus.

(5) When the light emitted from the light emitting device is expressed in an XYZ color system,
The value of the chromaticity coordinate x is in the range of 0.39 to 0.475,
The value of the chromaticity coordinate y is in the range of 0.375 or more and 0.425 or less, The light-emitting device according to (1),

(6) The light emitting device according to (5), wherein the light emission efficiency when driven at a current of 20 mA is 10 lm / W or more.

(7) The light emitting device according to (5) or (6), wherein the average color rendering index (Ra) is 80 or more and the special color rendering index (R9) is 27 or more.

(8) The green phosphor is (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, Mn, β- (Si, Al) ₁₂ (O , N) ₁₆ : Eu, and (Ca, Sr, Ba) Si ₂ N ₂ O ₂ : Eu contains at least one selected from the group consisting of Eu,
The blue phosphor is selected from the group consisting of (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu and (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu The light-emitting device according to any one of (5) to (7), comprising at least a seed.

(9) The light emitting device according to any one of (1) to (8), wherein the red phosphor contains a crystal phase having a chemical composition represented by the following formula [3].
(1-a-b) ( Eu y Ln 'w M II' 1-yw M III 'M IV' N 3)
・ A (M ^{IV ′} _{(3n + 2) / 4} N _n O) ・ b (AM ^{IV ′} ₂ N ₃ ) ... [3]
(In the above equation [3],
Ln ′ is at least one metal element selected from the group consisting of lanthanoids excluding Eu, Mn and Ti,
M ^{II ′} is one or more elements selected from the group consisting of divalent metal elements other than Eu and Ln ′ elements;
M ^{III ′} is one or more elements selected from the group consisting of trivalent metal elements,
M ^{IV ′} is one or more elements selected from the group consisting of tetravalent metal elements,
A is one or more monovalent metal elements selected from the group consisting of Li, Na, and K;
y is a number satisfying 0 <y ≦ 0.2,
w is a number satisfying 0 ≦ w <0.2;
a, b, and n are numbers satisfying 0 ≦ a, 0 ≦ b, a + b> 0, 0 ≦ n, and 0.002 ≦ (3n + 2) a / 4 ≦ 0.9. )

(10) The light emitting device according to (9), wherein the red phosphor contains a crystal phase having a chemical composition represented by the following formula [4].
_{(Eu y Ln '' w M} II 1-yw M III M IV N 3) 1-x (M IV (3n + 2) / 4 N n O) x ... [4]
(In the above equation [4],
Ln ″ is at least one metal element selected from the group consisting of lanthanoids excluding Eu, Mn and Ti,
M ^II is one or more elements selected from the group consisting of divalent metal elements in which the total of Mg, Ca, Sr, Ba, and Zn occupies 90 mol% or more,
M ^III is one or more elements selected from the group consisting of trivalent metal elements in which Al accounts for 80 mol% or more,
M ^IV is one or more elements selected from the group consisting of tetravalent metal elements in which Si accounts for 90 mol% or more,
y is a number satisfying 0 <y ≦ 0.2,
w is a number satisfying 0 ≦ w <0.2;
x is a number satisfying 0 <x ≦ 0.45,
n is a number satisfying 0 ≦ n,
n and x are numbers satisfying 0.002 ≦ (3n + 2) x / 4 ≦ 0.9. )

(11) The light emitting device according to (9), wherein the red phosphor contains a crystal phase having a chemical composition represented by the following formula [5].
_{(Eu y Ln '' w M} II 1-yw M III M IV N 3) 1-x '(AM IV 2 N 3) x' ... [5]
(In the above equation [5],
Ln ″ is a lanthanoid excluding Eu,
At least one metal element selected from the group consisting of Mn and Ti,
M ^II is one or more elements selected from the group consisting of divalent metal elements in which the total of Mg, Ca, Sr, Ba, and Zn occupies 90 mol% or more,
M ^III is one or more elements selected from the group consisting of trivalent metal elements in which Al accounts for 80 mol% or more,
M ^IV is one or more elements selected from the group consisting of tetravalent metal elements in which Si accounts for 90 mol% or more,
A is one or more metal elements selected from the group consisting of Li, Na, and K;
x ′ is a number satisfying 0 <x ′ <1.0,
y is a number satisfying 0 <y ≦ 0.2,
w is a number satisfying 0 ≦ w <0.2. )

  ADVANTAGE OF THE INVENTION According to this invention, the light-emitting device excellent in color rendering property and luminous efficiency is provided.

  Hereinafter, the present invention will be described with reference to embodiments and examples, but the present invention is not limited to the following embodiments and examples, and may be arbitrarily modified without departing from the gist of the present invention. Can be implemented.

In addition, in the composition formula of the fluorescent substance in this specification, each composition formula is delimited by a punctuation mark (,). In addition, when a plurality of elements are listed by separating them with commas (,), it indicates that one or more of the listed elements may be contained in any combination and composition. For example, the composition formula “(Ca, Sr, Ba) Al ₂ O ₄ : Eu” has “CaAl ₂ O ₄ : Eu”, “SrAl ₂ O ₄ : Eu”, and “BaAl ₂ O ₄ : Eu”. If: the _{"Ca 1-P Sr P Al 2} O 4 Eu ": a _{"Sr 1-P Ba P Al 2} O 4 Eu ": the _{"Ca 1-P Ba P Al 2} O 4 Eu " _{"Ca 1-P-Q Sr P} Ba Q Al 2 O 4: Eu " and all assumed to generically indicated (in the above formula, 0 <P <1,0 <Q <1,0 <P + Q <1).

The light-emitting device of the present invention (hereinafter referred to as “light-emitting device” as appropriate) includes a first light-emitting body (excitation light source), and a second light-emitting body that emits visible light when irradiated with light from the first light-emitting body. A light-emitting device having a physical property represented by the following formula [1] as a second light-emitting device, and a phosphor that emits red fluorescence (hereinafter referred to as “red phosphor” as appropriate) It is.
Specifically, an excitation light source as described later is used as the first light emitter, and a phosphor emitting green fluorescence as described later (hereinafter referred to as “green phosphor” as appropriate) in addition to the red phosphor as described above. And a phosphor that emits blue fluorescence (hereinafter, referred to as “blue phosphor” as appropriate), etc., in any combination and used to obtain a known device configuration.

  The light emitting device of the present invention has a first light emitter (excitation light source) and uses at least the above-described red phosphor, green phosphor, and blue phosphor as the second light emitter. The configuration is not limited, and a known device configuration can be arbitrarily employed. A specific example of the device configuration will be described later.

The light-emitting device of the present invention is preferably a light-emitting device that emits white light (hereinafter referred to as “white light-emitting device”).
Here, the white color of the white light emitting device means all of (yellowish) white, (greenish) white, (blueish) white, (purple) white and white defined by JIS Z 8701 Of these, white is preferred.

1. 1. Configuration of light emitting device 1-1. 1st light-emitting body The 1st light-emitting body in the light-emitting device of this invention light-emits the near-ultraviolet light which excites the 2nd light-emitting body mentioned later.

  The specific value of the emission peak wavelength of the first luminescent material used in the present invention is usually 300 nm or more, preferably 330 nm or more, more preferably 360 nm or more, and usually 420 nm or less, preferably 410 nm or less.

  As the first light emitter, a semiconductor light emitting element is generally used, and specifically, a light emitting LED, a semiconductor laser diode (hereinafter abbreviated as “LD” as appropriate), or the like can be used. In addition, as a light-emitting body which can be used as a 1st light-emitting body, an organic electroluminescent light emitting element, an inorganic electroluminescent light emitting element, etc. are mentioned, for example. However, what can be used as a 1st light-emitting body is not restricted to what is illustrated by this specification.

Among these, as the first light emitter, a GaN LED or LD using a GaN compound semiconductor is preferable. This is because GaN-based LEDs and LDs have significantly higher light emission output and external quantum efficiency than SiC-based LEDs that emit light in this region, and are extremely bright with very low power when combined with the phosphor. This is because light emission can be obtained. For example, for a current load of 20 mA, GaN-based LEDs and LDs usually have a light emission intensity 100 times or more that of SiC-based. GaN-based LEDs and LDs preferably have an Al _x Ga _y N light emitting layer, a GaN light emitting layer, or an In _x Ga _y N light emitting layer. Among GaN-based LEDs, those having an In _x Ga _y N light-emitting layer are particularly preferable because the emission intensity is very strong, and in GaN-based LEDs, those having a multiple quantum well structure of an In x GaYN layer and a GaN layer emit light. Since strength is very strong, it is particularly preferable.

  In the above, the value of X + Y is usually a value in the range of 0.8 to 1.2. In the GaN-based LED, those in which the light emitting layer is doped with Zn or Si or those without a dopant are preferable for adjusting the light emission characteristics.

A GaN-based LED has these light-emitting layer, p-layer, n-layer, electrode, and substrate as basic components, and the light-emitting layer is composed of n-type and p-type Al _x Ga _y N layers, GaN layers, or In _x. Those having a hetero structure sandwiched by Ga _Y N layers or the like are preferable because of high light emission efficiency, and those having a hetero structure having a quantum well structure are more preferable because of high light emission efficiency.
Note that only one first light emitter may be used, or two or more first light emitters may be used in any combination and ratio.

1-2. Second illuminant The second illuminant used in the present invention absorbs light in the wavelength range of 300 nm to 420 nm from the first illuminant, and converts the wavelength into red to emit visible light. It has a phosphor, a blue phosphor, and a green phosphor.

The phosphors of the respective colors will be described in detail below. As the red phosphor, those having a light emission peak in a wavelength range of 590 nm to 650 nm are preferable.
As the blue phosphor, one having an emission peak in a wavelength range of 420 nm to 470 nm is used.
As the green phosphor, one having an emission peak in a wavelength range of 510 nm to 545 nm is used.

The light emitting device of the present invention is required to include a red phosphor that satisfies the light emission characteristic represented by the formula [1] described later as the second light emitter. Other blue phosphors and green phosphors are not particularly limited as long as they have the above emission peak wavelength, and any phosphor can be used. However, phosphors described in detail below can be used. preferable.
In addition, the type of phosphor used so that the emission color of the light emitting device of the present invention becomes a desired emission color, for example, as exemplified in “1-2-4. Preferred combinations of phosphors” described later. The mixing ratio may be adjusted.

1-2-1. Red phosphor [luminescence characteristics]
The light emitting device of the present invention has a red phosphor satisfying the following formula [1] (hereinafter sometimes referred to as “the red phosphor of the present invention”) as the second light emitter.
I ₅₇₀ / I ₆₅₀ ≧ 0.3 ... [1]
(In the above formula [1],
I ₅₇₀ represents the emission intensity at 570 nm when the red phosphor is excited with light having a peak wavelength of 395 nm,
I ₆₅₀ represents the emission intensity at 650 nm when the red phosphor is excited with light having a peak wavelength of 395 nm. )

The value of I ₅₇₀ / I ₆₅₀ is the ratio of the emission intensity at 570 nm to the emission intensity at 650 nm. A larger value means that there is a bulge on the short wavelength side of the emission spectrum, which means that there are more yellow components.
Therefore, the value of I ₅₇₀ / I ₆₅₀ is preferably larger in constituting the white light emitting device, and is usually 0.3 or more, preferably 0.4 or more, more preferably 0.6 or more, and color rendering properties. From this point, it is usually 2 or less.

Moreover, it is preferable that the red phosphor of the present invention further satisfies the following formula [2].
S _L / S _R ≧ 1.56 ... [2]
(In the above equation [2],
S _L represents the total area on the short wavelength side of the emission peak wavelength of the emission spectrum measured by exciting the red phosphor with light having a peak wavelength of 395 nm,
S _R represents the total area on the longer wavelength side of the emission peak wavelength of the emission spectrum measured by exciting the red phosphor with light having a peak wavelength of 395 nm. )

The value of S _L / S _R is the ratio of the total area on the short wavelength side to the total area on the long wavelength side when the emission spectrum is divided into two with the emission peak wavelength as the boundary line. A larger value means that the emission spectrum has a bulge on the short wavelength side, and the emission spectrum has a tail on the short wavelength side.
Accordingly, the value of S _L / S _R is preferably larger when constituting a white light emitting device, and is usually 1.56 or more, preferably 1.7 or more, more preferably 1.8 or more, and color rendering properties. From this point, it is usually 3 or less.

  Note that the phosphor having such characteristics is preferably a nitride or oxynitride phosphor. Among them, it is preferable to include Eu, and it is more preferable that the base crystal includes an alkaline earth metal (in particular, Ca is preferable) and / or Si, and it is particularly preferable that Al is further included.

[composition]
Among the phosphors having such characteristics, the red phosphor of the present invention is preferably a phosphor containing a crystal phase having a chemical composition represented by the following formula [3].
A phosphor containing a crystal phase having a chemical composition represented by the formula [3] has an emission spectrum when excited by blue light (wavelength 455 nm) and when excited by near ultraviolet light (wavelength 395 nm). The shape is different (see FIG. 5). When used under excitation by near-ultraviolet light, this phosphor has the characteristics of the above formula [1] and is particularly excellent in terms of color rendering properties and luminous efficiency when used in a white light-emitting device.

(1-a-b) ( Eu y Ln 'w M II' 1-yw M III 'M IV' N 3)
・ A (M ^{IV ′} _{(3n + 2) / 4} N _n O) ・ b (AM ^{IV ′} ₂ N ₃ ) ... [3]
(In the above equation [3],
Ln ′ is at least one metal element selected from the group consisting of lanthanoids excluding Eu, Mn and Ti,
M ^{II ′} is one or more elements selected from the group consisting of divalent metal elements other than Eu and Ln ′ elements;
M ^{III ′} is one or more elements selected from the group consisting of trivalent metal elements,
M ^{IV ′} is one or more elements selected from the group consisting of tetravalent metal elements,
A is one or more monovalent metal elements selected from the group consisting of Li, Na, and K;
y is a number satisfying 0 <y ≦ 0.2,
w is a number satisfying 0 ≦ w <0.2;
a, b, and n are numbers satisfying 0 ≦ a, 0 ≦ b, a + b> 0, 0 ≦ n, and 0.002 ≦ (3n + 2) a / 4 ≦ 0.9. )

  In the above formula [3], Ln ′ is preferably at least one metal element selected from Ce, Tb, Sm, Mn, Dy, and Yb from the viewpoint of luminance.

M ^{II ′} preferably contains 90 mol% or more in total of one or more selected from the group consisting of Mg, Ca, Sr, Ba, and Zn. In terms of the luminance of the phosphor, examples of elements other than Mg, Ca, Sr, Ba, and Zn in M ^{II ′} include Mn, Sm, Eu, Tm, Yb, Pb, and Sn. In view of the luminance of the phosphor, M ^{II ′} particularly preferably contains a total of 80 mol% or more of Ca and / or Sr, more preferably 90 mol% or more, and most preferably 100 mol%. Further, the ratio of Ca with respect to the total of Ca and Sr in M ^{II ′} is preferably more than 10 mol%, and most preferably 100 mol%, that is, M ^{II ′} consists only of Ca.

As MIII ^′ , Al preferably occupies 80 mol% or more. From the point of luminance of the phosphor, elements other than Al in M ^{III ′} include Ga, In, B, Sc, Y, Bi, Sb, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and the like can be mentioned, among which Ga, In, B, Bi, Sc, Y, La, Ce, Gd, and Lu are preferable. From the viewpoint of the luminance of the phosphor, M ^{III ′} preferably contains 90 mol% or more of Al, and is most preferably 100 mol%, that is, M ^{III ′} is most preferably composed of only Al.

As M ^{IV ′} , Si preferably occupies 90 mol% or more. From the viewpoint of the brightness of the phosphor, examples of elements other than Si in M ^{IV ′} include Ge, Sn, Ti, Zr, Hf and the like, and among these, Ge is preferable. From the viewpoint of the luminance of the phosphor, it is most preferable that M ^{IV ′} is composed of only Si.

In the phosphor, the crystal structure of the crystal phase belongs to the space group Cmc2 ₁ or P2 ₁ .

  From the viewpoint of fluorescence emission, the red phosphor of the present invention may be referred to as a crystal phase (hereinafter referred to as “crystal phase [3]”) having a chemical composition represented by the formula [3]. 3] is sometimes referred to as “phosphor [3].”) And contains as much as possible with high purity, and most preferably comprises a single phase of the crystalline phase [3]. Desirable, but a mixture of the crystal phase [3] and a crystal phase having a crystal structure different from that of the crystal phase [3] (hereinafter referred to as “other crystal phase”) and / or an amorphous phase, as long as the characteristics are not deteriorated. It may be. In this case, it is desirable that the content of the crystal phase [3] in the phosphor [3] is 20% by mass or more in order to obtain high luminance. More preferably, the luminance is remarkably improved when the content of the crystal phase [3] in the phosphor [3] is 50 mass% or more. The content ratio of the crystal phase [3] in the phosphor [3] can be determined from the ratio of the strongest peak intensities of the crystal phase [3] and other phases by X-ray diffraction measurement.

  The phosphor [3] containing a crystal phase having the chemical composition represented by the formula [3] emits fluorescence having a peak at a wavelength in the range of 590 nm to 650 nm when irradiated with an excitation source. It is preferable.

  Hereinafter, the phosphor [3] containing a crystal phase having the chemical composition represented by the formula [3] will be described in more detail.

The phosphor [3] is preferably a phosphor containing a crystal phase having a chemical composition represented by the following formula [4] (that is, the formula [3] is preferably the following formula [4]. ).
_{(Eu y Ln '' w M} II 1-yw M III M IV N 3) 1-x (M IV (3n + 2) / 4 N n O) x ... [4]

In the above formula [4], Ln ″ is at least one metal element selected from the group consisting of lanthanoids excluding Eu, Mn and Ti, and among these, Ce, Tb, Sm, Mn, Dy, At least one metal element selected from Yb is preferable from the viewpoint of luminance.
M ^II is one or more elements selected from the group consisting of divalent metal elements, and totals one or more elements selected from the group consisting of Mg, Ca, Sr, Ba, and Zn. It contains 90 mol% or more.
M ^III is one or more elements selected from the group consisting of trivalent metal elements in which Al accounts for 80 mol% or more.
M ^IV is one or more elements selected from the group consisting of tetravalent metal elements in which Si accounts for 90 mol% or more.
y is a number that satisfies 0 <y ≦ 0.2, w is a number that satisfies 0 ≦ w <0.2, x is a number that satisfies 0 <x ≦ 0.45, and n is It is a number that satisfies 0 ≦ n, and n and x are numbers that satisfy 0.002 ≦ (3n + 2) x / 4 ≦ 0.9.

Among phosphors containing a crystal phase having a chemical composition represented by the above formula [4], a phosphor containing a crystal phase having a chemical composition represented by the following formula [4A] (hereinafter referred to as “phosphor [4A] Is preferable (that is, the formula [4] is preferably the following formula [4A]).
(Eu _y M ^II _1-y M ^III M ^IV N ₃ ) _1-x (M ^IV _{(3n + 2) / 4} N _n O) _x ... [4A]

In the above formulas [4A], M ^II is a divalent metal element, is intended to include Mg, Ca, Sr, Ba, and one or 90 mol% or more of two or more in total selected from the group consisting of Zn. From the viewpoint of brightness of the phosphor, Mg in ^{M II, Ca, Sr, Ba} , as an element other than Zn is, Mn, Sm, Eu, Tm , Yb, Pb, Sn and the like. In view of the luminance of the phosphor, M ^II particularly preferably contains 80 mol% or more of Ca and / or Sr in total, more preferably 90 mol% or more, and most preferably 100 mol%. Further, the ratio of Ca with respect to the total of Ca and Sr in M ^II is preferably more than 10 mol%, and most preferably 100 mol%, that is, M ^II consists only of Ca.

M ^III is a trivalent metal element and contains 80 mol% or more of Al. From the viewpoint of brightness of the phosphor, the elements other than Al in ^{M III, Ga, In, B} , Sc, Y, Bi, Sb, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho , Er, Tm, Yb, Lu, etc., among which Ga, In, B, Bi, Sc, Y, La, Ce, Gd, and Lu are preferable. From the viewpoint of the luminance of the phosphor, M ^III preferably contains 90 mol% or more of Al, and is most preferably 100 mol%, that is, M ^III consists of Al alone.

^MIV is a tetravalent metal element and contains Si by 90 mol% or more. From the viewpoint of brightness, as the elements other than Si in M ^IV, Ge, Sn, Ti, Zr, include Hf, etc., Ge is preferred among this. From the viewpoint of luminance, it is most preferable that ^MIV is composed only of Si.

  As long as the luminance of the phosphor is not significantly reduced, monovalent, pentavalent, and hexavalent elements other than divalent, trivalent, and tetravalent are added in an amount of 0.05 mol or less ([[ 4A] may be introduced in a range of 0.05 mol or less with respect to 1 mol of the formula. In this case, it is preferable to introduce the charge compensation while maintaining lattice compensation because it is difficult to cause lattice defects that cause a decrease in luminance.

  y is the molar ratio of the activating element Eu and is a number satisfying 0.0001 ≦ y ≦ 0.1. From the viewpoint of the emission intensity of the phosphor, 0.001 ≦ y ≦ 0.1 is preferable, and 0.003 ≦ y ≦ 0.05 is more preferable. When y exceeds 0.1, concentration quenching occurs, and when it falls below 0.0001, light emission tends to be insufficient.

x and n are, CaAlSiN _3: EuM typified by _{^{Eu II M III M IV N 3}} : M IV (3n + 2) typified by Eu and _{Si 2 N 2 O / 4 N} n O M IV to the sum of _{(3n + 2) / 4} is a mole ratio of N _n O, satisfying 0 <x ≦ 0.45 and satisfying 0.002 ≦ (3n + 2) x / 4 ≦ 0.9. From the point of brightness of the phosphor,
0.01 ≦ x ≦ 0.45 and 0.02 ≦ (3n + 2) x / 4 ≦ 0.9 are preferable,
More preferably, 0.04 ≦ x ≦ 0.4 and 0.08 ≦ (3n + 2) x / 4 ≦ 0.8,
More preferably, 0.1 ≦ x ≦ 0.4 and 0.16 ≦ (3n + 2) x / 4 ≦ 0.8,
Most preferably, 0.2 ≦ x ≦ 0.4 and 0.4 ≦ (3n + 2) x / 4 ≦ 0.8.

Further, as the phosphor [3], a phosphor containing a crystal phase having a chemical composition represented by the following formula [5] is also preferable (that is, the formula [3] is the following formula [5]. preferable.). Preferably, the crystal structure of this crystal phase belongs to the same space group Cmc2 ₁ as CaAlSiN ₃ .
_{(Eu y Ln '' w M} II 1-yw M III M IV N 3) 1-x '(AM IV 2 N 3) x' ... [5]

In the above formula [5], Ln ″ is at least one metal element selected from the group consisting of lanthanoids excluding Eu, Mn and Ti, and among these, Ce, Tb, Sm, Mn, Dy, At least one metal element selected from Yb is preferable from the viewpoint of luminance. M ^II is a divalent metal element, and contains 90 mol% or more in total of one or more selected from the group consisting of Mg, Ca, Sr, Ba, and Zn. M ^III is a trivalent metal element and contains 80 mol% or more of Al. ^MIV is a tetravalent metal element containing 90 mol% or more of Si, and A is one or more metal elements selected from the group consisting of Li, Na, and K. x ′ is a number that satisfies 0 <x ′ <1.0, y is a number that satisfies 0 <y ≦ 0.2, and w is a number that satisfies 0 ≦ w <0.2.

Among phosphors containing a crystal phase having a chemical composition represented by the above formula [5], a phosphor containing a crystal phase having a chemical composition represented by the following formula [5A] (hereinafter referred to as “phosphor [5A] ] Is preferable (that is, the formula [5] is preferably the following formula [5A]).
(Eu _y M ^II _1-y M ^III M ^IV N ₃ ) _{1-x ′} (AM ^IV ₂ N ₃ ) _{x ′} ... [5A]

In the above formula [5A], M ^II is a divalent metal element in which the total of Mg, Ca, Sr, Ba and Zn occupies 90 mol% or more, and M ^III is a trivalent in which Al occupies 80 mol% or more. a metal element, M ^IV is, Si is a tetravalent metal element accounts for at least 90 mol%, a is at least one metal element selected from the group consisting of Li, Na, and K, x ' Is a number satisfying 0 <x ′ <0.5, and y is a number satisfying 0 <y ≦ 0.2.

In the formula [5A], M ^II is a divalent metal element, it is intended to include Mg, Ca, Sr, Ba, and one or 90 mol% or more of two or more in total selected from the group consisting of Zn. From the viewpoint of the luminance of the phosphor, M ^II particularly preferably contains 80 mol% or more of Ca and / or Sr in total, more preferably 90 mol% or more, and most preferably 100 mol%. Further, the ratio of Ca with respect to the total of Ca and Sr in M ^II is preferably more than 10 mol%, and most preferably 100 mol%, that is, M ^II consists only of Ca. M ^II may contain an element that can be co-activated with Eu, such as Mn.

M ^III is a trivalent metal element and contains 80 mol% or more of Al. From the viewpoint of brightness of the phosphor, the elements other than Al in ^{M III, Ga, In, B} , Sc, Y, Bi, although Sb and the like, among this, Ga, an In, Sc, Y is preferably . From the viewpoint of the luminance of the phosphor, M ^III preferably contains 90 mol% or more of Al, and is most preferably 100 mol%, that is, M ^III consists of Al alone.

^MIV is a tetravalent metal element and contains 90 mol% or more of Si. From the viewpoint of brightness, as the elements other than Si in M ^IV, Ge, Sn, Zr, include Hf, etc., Ge is preferred among this. From the viewpoint of luminance, it is most preferable that ^MIV is composed only of Si.

  A is one or more monovalent metal elements selected from the group consisting of Li, Na, and K. From the viewpoint of luminance, A is preferably Li and / or Na, more preferably Li.

  As long as the luminance of the phosphor is not significantly reduced, pentavalent and hexavalent elements other than monovalent, divalent, trivalent, and tetravalent valences in the formula [5A] are 0.05 mol or less ([[ 5A] may be introduced in a range of 0.05 mol or less with respect to 1 mol of the formula. In this case, it is preferable to introduce the charge compensation while maintaining lattice compensation because it is difficult to cause lattice defects that cause a decrease in luminance.

Next, each parameter of the formula [5A] will be described.
y is a parameter representing the amount of Eu. y is the molar ratio of Eu and is a number satisfying 0 <y ≦ 0.2. When y exceeds 0.2, concentration quenching occurs, and when it falls below 0.003, light emission tends to be insufficient. Therefore, y is preferably 0.003 ≦ y ≦ 0.2.

x ′ is a parameter representing the presence state of one or more monovalent metal elements selected from the group consisting of Li, Na, and K as A in the host crystal. With the introduction of one or more of Li, Na, and K, x ′ was introduced so that the principle of electrical neutrality was maintained for the M ^II , M ^III , and M ^IV ions. x ′ is a number satisfying 0 <x ′ <0.5. From the viewpoint of luminance, x ′ is preferably 0.002 ≦ x ′ ≦ 0.4, and more preferably 0.03 ≦ x ′ ≦ 0.35.

The formulas [3], [4], [4A], [5], and [5A] are formulas representing theoretical substances. The influence of oxygen contained as impurities in the raw material Si ₃ N ₄ and AlN, and the out-of-sample oxygen that causes the raw material Ca ₃ N _{2 and the} like to be slightly oxidized during the operations from mixing of raw materials to firing The oxygen and nitrogen contents in the substance actually obtained may be different from the theoretical values due to the influence of contamination, etc., but some deviation of the oxygen and nitrogen contents due to this will adversely affect the light emission characteristics. Therefore, the actual oxygen content and nitrogen content may be slightly different from the values of the above equations [4A] and [5A].
Among the above formulas, the above formula [4] is preferable, and the above formula [4A] is more preferable.

In the formulas [3], [4], [4A], [5], and [5A], y indicating the Eu amount is preferably 0.001 or more and 0.02 or less.
Further, x indicating the solid solution rate is preferably 0.1 ≦ x ≦ 0.33, more preferably 0.13 ≦ x ≦ 0.30, and still more preferably 0.13 ≦ x ≦ 0.2. Similarly, x ′ is preferably 0.1 ≦ x ′ ≦ 0.33, more preferably 0.13 ≦ x ′ ≦ 0.30, and still more preferably 0.13 ≦ x ′ ≦ 0.2. Particularly in the case of the phosphor [4A], Si / Al is preferably 1.2 ≦ Si / Al ≦ 1.7, particularly 1.27 ≦ Si / Al ≦ 1.5, and O / Al is 0.1. ≦ O / Al ≦ 0.5, and particularly preferably 0.12 ≦ O / Al ≦ 0.3.

[Other characteristics]
<Particle size>
When the red phosphor of the present invention is used as a powder, the weight median diameter D ₅₀ is usually 0.1 μm or more, preferably 5 μm or more, and usually 20 μm from the viewpoints of dispersibility in resin and fluidity of the powder. The following is preferable. Further, by making the powder into single crystal particles in this range, the emission luminance is further improved.

<Amount of impurities>
In order to obtain a phosphor with high emission luminance, it is preferable that impurities contained in the phosphor are as small as possible. In particular, when a large amount of impurity elements such as Fe, Co, and Ni are contained, light emission is inhibited. Therefore, it is preferable to select the raw material powder and control the synthesis process so that the total of these elements is 500 ppm or less.

<Quantum efficiency>
When the red phosphor of the present invention is excited with light having a wavelength of 395 nm, the external quantum efficiency is usually 60% or more, preferably 65% or more, most preferably 67% or more, and the internal quantum efficiency is usually 70% or more. Preferably it is 75% or more, Most preferably, it is 78% or more.

[Production method]
Although there is no restriction | limiting in particular in the manufacturing method of the red fluorescent substance of this invention, For example, it is a mixture of a metal compound, Comprising: By baking, said Formula [3], Preferably said Formula [4] or [5], More preferably, by firing the raw material mixture that can constitute the composition represented by the formula [4A] or [5A] in a temperature range of 1200 ° C. or higher and 2200 ° C. or lower in an inert atmosphere containing nitrogen, Can be manufactured.

The main crystal of the phosphor [4A] belongs to the space group Cmc2 ₁ , but depending on the synthesis conditions such as the firing temperature, a part of the crystal is monoclinic instead of orthorhombic, and crystals that are in a space group different from Cmc2 ₁ are mixed. Even in this case, since the change in the light emission characteristics of the luminescent center element Eu site is slight, it can be used as a high-luminance phosphor.

In particular, when the phosphor [4A] is produced by the above method, europium nitride and / or europium oxide (europium fluoride may be used), calcium nitride, and silicon nitride (an imide compound containing silicon). In addition to aluminum nitride, alumina, silica, calcium carbonate, calcium oxide, or a composite oxide of Al and Si, or a composite oxide of Al and Ca may be used as the oxygen source of Si ₂ N ₂ O. A mixed powder of a metal compound such as a complex oxide of Si and Ca or a complex oxide of Al, Si and Ca is preferably used as a starting material.

In particular, according to the above method, the phosphor [5A] :( Eu _y Ca _1-y AlSiN ₃ ) _{1-x ′} (M ^II is Ca, M ^III is Al, M ^IV is Si, and A is Li. When synthesizing LiSi ₂ N ₃ ) _{x ′} , a mixture of europium nitride, calcium nitride, lithium nitride, silicon nitride, and aluminum nitride powder is preferably used as a starting material.

<Mixing process>
The phosphor raw material is weighed so as to obtain the target composition, mixed sufficiently using a ball mill or the like, then filled in a crucible, fired at a predetermined temperature and atmosphere, and the fired product is pulverized and washed, thereby producing the present invention. The phosphor can be obtained.

The mixing method is not particularly limited. Specifically, for example, a dry pulverizer such as a hammer mill, a roll mill, a ball mill, or a jet mill, or pulverization using a mortar and pestle, for example, a ribbon blender, a V-type Examples thereof include a dry mixing method in which a blender such as a blender or a Henschel mixer, or mixing using a mortar and a pestle is combined and the above-mentioned raw materials are pulverized and mixed.
Mixing of the raw materials is preferably performed by mixer mixing in a moisture-controlled N ₂ glove box so that the nitride raw materials are not deteriorated by moisture. The moisture in the work place where mixing is performed is preferably 10,000 ppm or less, preferably 1000 ppm or less, more preferably 10 ppm or less, and still more preferably 1 ppm or less. Also, oxygen is 1% or less, preferably 10,000 ppm or less, more preferably 100 ppm or less, and still more preferably 10 ppm or less.

<Baking process>
The obtained mixture is filled in a heat-resistant container such as a crucible or a tray made of a material having low reactivity with each raw material. Examples of the material of the heat-resistant container used at the time of firing include ceramics such as alumina, quartz, boron nitride, silicon nitride, silicon carbide, magnesium, mullite, platinum, molybdenum, tungsten, tantalum, niobium, iridium, rhodium, and the like. Examples thereof include metals, alloys containing them as main components, and carbon (graphite).
Examples of such heat-resistant containers are preferably boron nitride, silicon nitride, silicon carbide, platinum, molybdenum, tungsten, and tantalum heat resistant containers, more preferably made of boron nitride. is there.

  The filling rate when filling the phosphor material into the heat-resistant container (hereinafter referred to as “heat-resistant container filling rate”) varies depending on the firing conditions, but the fired product is pulverized in a post-treatment step described later. It may be filled to such an extent that it does not become difficult to perform, and is usually 10% by volume or more and usually 90% by volume or less.

Further, when it is desired to increase the amount of the phosphor raw material to be processed at a time, it is preferable that heat is uniformly circulated in the heat-resistant container, for example, by decreasing the rate of temperature rise.
Moreover, it is preferable that the filling rate (hereinafter referred to as “furnace filling rate” as appropriate) when filling the heat-resistant container in the furnace is such that heat does not become uneven between the heat-resistant containers in the furnace.
Furthermore, in the above baking, when the number of heat-resistant containers in the baking furnace is large, for example, to make the heat transfer to each heat-resistant container uniform, such as slowing the temperature increase rate, It is preferable for firing without unevenness.

  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 firing method is preferably a sintering method in which no mechanical pressure is applied from the outside, such as an atmospheric pressure sintering method or a gas pressure sintering method.

  Regarding the firing step, the fired powder usually sinters at a firing temperature exceeding 2200 ° C., and the light emission intensity may be lowered. However, the powder having good crystallinity at a firing temperature of about 1700 ° C. to 1800 ° C. Is obtained. Accordingly, the firing temperature for producing the phosphor of the present invention is usually 1000 ° C. or higher, preferably 1300 ° C. or higher, more preferably 1500 ° C. or higher, and usually 2000 ° C. or lower, preferably 1900. The temperature is not higher than ° C, more preferably not higher than 1850 ° C.

  Although it does not restrict | limit especially as a baking atmosphere, Usually, it carries out in the inert gas atmosphere containing nitrogen. In addition, an inert gas may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio. Moreover, the one where the oxygen concentration in an inert gas is low is preferable, and it is preferable that oxygen concentration is 100 ppm or less normally.

  The firing time is usually 0.5 hours or longer, preferably 1 hour or longer, although it varies depending on the temperature and pressure during firing. Moreover, it is 100 hours or less normally, Preferably it is 50 hours or less, More preferably, it is 24 hours or less, More preferably, it is 12 hours or less.

Although the pressure at the time of firing varies depending on the firing temperature and the like, it is not particularly limited, but is usually 1 × 10 ⁻⁵ Pa or more, preferably 1 × 10 ⁻³ Pa or more, more preferably 0.01 MPa or more, and still more preferably 0.8. The upper limit is usually 5 GPa or less, preferably 1 GPa or less, more preferably 200 MPa or less, and still more preferably 100 MPa or less. Among these, the atmospheric pressure to about 1 MPa is industrially preferable in terms of cost and labor.
Moreover, in a baking process, you may coexist a flux with a reaction system from a viewpoint of growing a favorable crystal | crystallization.

<Primary firing and secondary firing>
The firing step may be divided into primary firing and secondary firing, and the raw material mixture obtained by the mixing step may be first fired first, and then pulverized again with a ball mill or the like, followed by secondary firing.

Here, the primary firing temperature of the phosphor of the present invention is arbitrary as long as the effects of the present invention are not significantly impaired, but the primary firing temperature for the purpose of preventing side reactions such as hydrolysis of intermediate nitride during firing. Is preferably not too low, usually in the range of 1000 ° C. or higher, preferably 1300 ° C. or higher, and usually 1800 ° C. or lower, preferably 1700 ° C. or lower, more preferably 1600 ° C. or lower.
The time for the primary firing is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 1 hour or longer, preferably 2 hours or longer, and usually 100 hours or shorter, preferably 50 hours or shorter, more preferably 24 hours or shorter. More preferably, it is 12 hours or less.

The conditions such as the temperature and time of the secondary firing are basically the same as the conditions described in the above-mentioned firing step column.
The flux may be mixed before the primary firing or may be mixed before the secondary firing. Also, the firing conditions such as the atmosphere may be changed between the primary firing and the secondary firing.

When the powder aggregate obtained by firing is firmly fixed, it is pulverized by a pulverizer generally used industrially, such as a ball mill or a jet mill. The pulverization is preferably performed so that the weight median diameter D ₅₀ of the powder is usually 0.1 μm or more, preferably 5 μm or more, and usually 20 μm or less, preferably 15 μm or less. When the average particle size exceeds 20 μm, the fluidity and dispersibility in the resin are poor, and the luminous intensity is uneven depending on the site when forming a lighting fixture or image display device in combination with a light emission source or excitation source. become. When the average particle size is pulverized to less than 0.1 μm, the amount of defects on the surface of the phosphor powder increases, so that the emission intensity may decrease depending on the phosphor composition.

  Also, an alloy containing at least two metal elements constituting the phosphor, preferably an alloy containing all the metal elements constituting the phosphor, is prepared, and the obtained alloy is heated under pressure in a nitrogen-containing atmosphere. It can be manufactured by processing. In addition, an alloy containing a part of the metal element constituting the phosphor is prepared, and the obtained alloy is heat-treated under pressure in a nitrogen-containing atmosphere, and then the remaining metal element source constituting the phosphor It can also manufacture by mixing with the raw material compound which becomes and heat-processing. Thus, the phosphor manufactured through the alloy is a phosphor with few impurities and high luminance.

  The obtained phosphor is preferably dispersed in the resin after performing a known surface treatment such as calcium phosphate treatment as necessary.

1-2-2. Green phosphor In the light emitting device of the present invention, a green phosphor having a fluorescence peak in a wavelength range of 510 nm or more and 545 nm or less is used. As this green phosphor (hereinafter sometimes referred to as “the green phosphor of the present invention”), (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, Mn, β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu, and (Ca, Sr, Ba) Si ₂ N ₂ O ₂ : One or more selected from the group consisting of Eu Is preferably used.
Hereinafter, each phosphor will be described.

1-2-2-1. (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu phosphor [composition]
In the light emitting device of the present invention, a silicate green phosphor represented by (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu as a green phosphor (hereinafter referred to as “silicate green phosphor of the present invention”). Can be used. Among them, it is preferable to use a phosphor whose composition is represented by the following formula [11], and more preferably a phosphor having the characteristics described below. A phosphor represented by the following formula [11] and having the characteristics described below can be manufactured by a manufacturing method described below.

_{^{(G I (1-c-}} d) G II c G III d) α SiO β ... [11]
(In the above formula [11],
G ^I represents Ba, Ca, Sr, one or more elements selected from the group consisting of Zn and Mg,
G ^II represents one or more metal elements capable of taking divalent and trivalent valences,
G ^III represents one or more elements selected from the group consisting of Tb, Pr, Ce, Lu, La, and Gd,
c, d, α and β are each
0.01 <c <0.3,
0 ≦ d ≦ 0.025,
1.5 ≦ α ≦ 2.5,
as well as,
3.5 ≦ β ≦ 4.5
Represents a number that satisfies )

In the formula [11], ^{G I} represents Ba, Ca, Sr, one or more elements selected from the group consisting of Zn and Mg. The G ^I, may also contain any one of these elements alone, or two or more may be of them together in any combination and in any ratio.

Among them, ^{G I} preferably contains at least Ba. In this case, the molar ratio of Ba to the total ^{G I} is usually 0.5 or more and preferably 0.55 or more, more preferably 0.6 or more, and usually less than 1, among others 0.97 or less, more 0. A range of 9 or less, particularly 0.8 or less is preferred. If the molar ratio of Ba is too high, the emission peak wavelength tends to shift to the short wavelength side. On the other hand, if the molar ratio of Ba is too low, the light emission efficiency tends to decrease.

In particular, ^{G I} preferably contains at least Ba and Sr. Here, when the respective molar ratios of Ba and Sr for the entire ^{G I} [Ba] and [Sr], the ratio of [Ba] to the total of [Ba] and [Sr], i.e., [Ba] / ([Ba ] + [Sr]) is usually larger than 0.5, preferably 0.6 or more, more preferably 0.65 or more, and usually 1 or less, especially 0.9 or less, Furthermore, it is preferable that it is the range of 0.8 or less. If the value of [Ba] / ([Ba] + [Sr]) is too small (that is, the ratio of Ba is too small), the emission peak wavelength of the phosphor shifts to the longer wavelength side, and the half-value width increases. Tend. On the other hand, if the value of [Ba] / ([Ba] + [Sr]) is too large (that is, the ratio of Ba is too large), the emission peak wavelength of the phosphor tends to shift to the short wavelength side.

  In addition, the relative ratio between [Ba] and [Sr], that is, the value represented by [Ba] / [Sr] is usually larger than 1, especially 1.2 or more, further 1.5 or more, especially 1 It is preferably 8 or more, and is usually 15 or less, preferably 10 or less, more preferably 5 or less, and particularly preferably 3.5 or less. If the value of [Ba] / [Sr] is too small (that is, the ratio of Ba is too small), the emission peak wavelength of the phosphor tends to shift to the longer wavelength side and the half-value width tends to increase. On the other hand, if the value of [Ba] / [Sr] is too large (that is, the ratio of Ba is too large), the emission peak wavelength of the phosphor tends to shift to the short wavelength side.

Further, in the formula [11], ^{if G I} contains at least Sr, part of Sr may be replaced by Ca. In this case, the amount of substitution with Ca is the value of the molar ratio of the amount of Ca substitution to the total amount of Sr, and is usually 35% or less, preferably 10% or less, more preferably 2% or less. If the ratio of the amount of substitution with Ca is too high, the light emission is yellowish and the light emission efficiency tends to decrease.

  Further, Si may be partially substituted by other elements such as Ge. However, from the standpoint of green emission intensity and the like, it is preferable that the ratio of Si substituted by other elements is as low as possible. Specifically, other elements such as Ge may be contained in an amount of 20 mol% or less of Si, and it is more preferable that all are made of Si.

In the above formula [11], G ^II is listed as an activator element and represents one or more metal elements that can have a divalent and trivalent valence. Specific examples include transition metal elements such as Cr and Mn; rare earth elements such as Eu, Sm, Tm, and Yb. The G ^II, may contain any one of these elements alone, or two or more may be of them together in any combination and in any ratio. Among these, as G ^II , Sm, Eu, and Yb are preferable, and Eu is particularly preferable. The molar ratio of the divalent element to the entire G ^II (the sum of the divalent element and the trivalent element) is usually 0.5 or more, preferably 0.7 or more, more preferably 0.8 or more, Usually, it is less than 1, and the closer to 1, the better. If the molar ratio of the divalent element to the entire G ^II is too low, the luminous efficiency tends to decrease. This is because a divalent element and a trivalent element are taken into the crystal lattice, but it is considered that the trivalent element absorbs emission energy in the crystal.

In the formula [11], G ^III represents one or more elements selected from the group consisting of Tb, Pr, Ce, Lu, La, and Gd. The G ^III, may contain any one of these elements alone, or two or more may be of them together in any combination and in any ratio.
These Tb, Pr, Ce, Lu, La, and Gd have the property of low ionization energy. Among these, Tb, Pr, and Ce are likely to change from divalent to trivalent, and easily change from trivalent to tetravalent. Lu, La, and Gd are likely to change from divalent to trivalent.

These G ^III contribute to light emission together with G ^II , and are presumed to function as a co-acting element. That is, for example, when Tb is contained as G ^III , a change in emission spectrum similar to that when G ^II (an activator element, for example, Eu) is excessively contained is observed. That is, the emission peak wavelength shifts to the longer wavelength side, but no change is seen in the half-value width of the emission spectrum, and a green emission spectrum with high color purity can be maintained. Therefore, G ^III including Tb contributes to light emission together with G ^II , and is presumed to function as a coactivator element.

Among these, G ^III is preferably one or more elements selected from the group consisting of Tb, Pr and Ce, more preferably contains at least Tb, and particularly preferably consists only of Tb. When Tb is contained as G ^III , when this phosphor is combined with the first luminous body to produce a light emitting device, the durability is improved as compared with the case where only G ^II is used as an activator, and the lamp is lit for a long time. The effect of small change in the shape of the spectrum and small color shift can be obtained. Further, when Tb is added in a specific range, the temperature characteristics can also be improved. It is presumed that the same effect as Tb can be obtained with other elements other than Tb.

In the above formula [11], c is a number representing the number of moles of G ^II , and is specifically greater than 0.01, preferably 0.04 or more, more preferably 0.05 or more, particularly preferably. Represents a number of 0.06 or more, usually less than 0.3, preferably 0.2 or less, more preferably 0.16 or less. If the value of c is too small, the emission intensity tends to be small. On the other hand, if the value of c is too large, the emission intensity tends to decrease.

In the above formula [11], d is a number representing the number of moles of G ^III, specifically, usually 0 or more, preferably 0.0001 or more, more preferably 0.001 or more, more preferably 0. It represents a number of 002 or more, usually 0.025 or less, preferably 0.02 or less, more preferably 0.015 or less. If the value of d is too small, the durability improving effect tends to be difficult to obtain. On the other hand, if the value of d is too large, the temperature characteristics tend to deteriorate. In particular, when it is desired to obtain a phosphor having excellent durability and excellent temperature characteristics, it is preferable to adjust the value of d to a range of 0.002 to 0.01.

  In the formula [11], α is preferably close to 2, but is usually 1.5 or more, preferably 1.7 or more, more preferably 1.8 or more, and usually 2.5 or less, preferably 2 .2 or less, more preferably 2.1 or less. If the value of α is too small or too large, heterogeneous crystals appear, and the light emission characteristics tend to deteriorate.

  In the formula [11], β is usually 3.5 or more, preferably 3.8 or more, more preferably 3.9 or more, and usually 4.5 or less, preferably 4.4 or less, more preferably 4 Represents a number in the range of 1 or less. If the value of β is too small or too large, heterogeneous crystals appear and the light emission characteristics tend to deteriorate.

Moreover, the silicate-based green phosphor of the present invention, elements that are described in the formula [11], i.e. ^{G I, G II, G III} , in addition to Si (silicon) and O (oxygen), further, a monovalent An element selected from the group consisting of an element, a divalent element, a trivalent element, a −1 valent element, and a −3 valent element (hereinafter referred to as “trace element” as appropriate) may be contained.

  Among these, as trace elements, alkali metal elements, alkaline earth metal elements, zinc (Zn), yttrium (Y), aluminum (Al), scandium (Sc), phosphorus (P), boron (B), nitrogen (N ), At least one element selected from the group consisting of rare earth elements and halogen elements.

  The total content of the trace elements is usually 1 ppm or more, preferably 3 ppm or more, more preferably 5 ppm or more, and usually 100 ppm or less, preferably 50 ppm or less, more preferably 30 ppm or less. When the silicate green phosphor of the present invention contains a plurality of kinds of trace elements, the total amount thereof satisfies the above range.

  Specific examples of preferred compositions of the silicate green phosphor of the present invention represented by the formula [11] are listed in Table 1 below, but the composition of the silicate green phosphor of the present invention is limited to the following examples. It is not a thing.

  The silicate green phosphor of the present invention may contain Al in addition to the above elements. The Al content is usually 1 ppm or more, preferably 5 ppm or more, more preferably 10 ppm or more, and usually 500 ppm or less, preferably 200 ppm or less, more preferably 100 ppm or less.

  Further, the silicate green phosphor of the present invention may contain B (boron) in addition to the above elements. The content of B is usually 1 ppm or more, preferably 3 ppm or more, more preferably 5 ppm or more, and usually 100 ppm or less, preferably 50 ppm or less, more preferably 30 ppm or less.

  The silicate green phosphor of the present invention may contain Fe in addition to the above elements. The Fe content is usually 1 ppm or more, preferably 3 ppm or more, more preferably 5 ppm or more, and usually 100 ppm or less, preferably 50 ppm or less, more preferably 30 ppm or less.

  The silicate green phosphor of the present invention may contain N in addition to the above elements. The content of N is usually 10 mol% or less, preferably 5 mol% or less, more preferably 3 mol% or less with respect to the amount of oxygen contained in the phosphor.

[Characteristic]
The silicate green phosphor of the present invention preferably has the following characteristics.

<Object color>
The silicate green phosphor of the present invention has the following L ^* value, a ^* value, and b ^* value when the object color is expressed in the L ^* a ^* b ^* color system (CIE 1976 color system). It is preferable to satisfy the formula.
L ^* ≧ 90
a ^* ≦ −20
b ^* ≧ 30

  Since the silicate green phosphor of the present invention has an object color that satisfies the above conditions, a light emitting device with high luminous efficiency can be realized when used in the light emitting device of the present invention.

Specifically, the upper limit of a ^* of the silicate green phosphor of the present invention is usually −20 or less, preferably −25 or less, more preferably −30 or less. A phosphor in which a ^* is too large tends to reduce the total luminous flux. Also, from the viewpoint of increasing luminance, it is desirable that the value of a ^* is small.

The b ^* of the silicate green phosphor of the present invention is usually in the range of 30 or more, preferably 35 or more, more preferably 40 or more. If b ^* is too small, the luminance tends to decrease. On the other hand, the upper limit of b ^* is theoretically 200 or less, but is usually preferably 120 or less. If b ^* is too large, the emission wavelength tends to shift to the longer wavelength side and the luminance tends to decrease.

Further, the ratio of a ^* and b ^* of the silicate green phosphor of the present invention, that is, the value represented by a ^* / b ^* is usually −0.45 or less, preferably −0.5 or less, more preferably. Is in the range of −0.55 or less. If the value of a ^* / b ^* is too large, the object color tends to be yellowish and the luminance tends to decrease.

Further, L ^* of the silicate green phosphor of the present invention is usually 90 or more, preferably 95 or more, and more preferably 100 or more. If the value of L ^* is too small, the light emission tends to be weak. On the other hand, the upper limit value of L ^* generally does not exceed 100 because it deals with an object that does not emit light by irradiation light, but the silicate green phosphor of the present invention emits light generated by being excited by irradiation light. Is superimposed on the reflected light, the value of L ^* may exceed 100. Specifically, the upper limit value of L ^* of the silicate green phosphor of the present invention is usually 115 or less.

The object color of the silicate green phosphor of the present invention can be measured, for example, by using a commercially available object color measuring device (for example, CR-300 manufactured by Minolta).
The object color means a color when light is reflected by the object. In the present invention, it measured (i.e., the phosphor) light (a white light source. For example, it is possible to use a standard light D _65.) Which is determined was irradiated with the reflected light obtained was dispersed by filter Thus, the values of L ^* , a ^* , and b ^* are obtained.
The object color is related to the degree of reduction of the phosphor material (for example, expressed as a ratio of the molar ratio of the divalent element to the entire G ^II ), and when the degree of reduction is high (for example, the divalent to the entire G ^II When the molar ratio of the elements is high), it is considered that the object color is in the above range. As will be described later, when the phosphor material is produced according to a specific production method such as firing a phosphor material in a strongly reducing atmosphere such as the presence of solid carbon, a phosphor having an object color in the above range can be obtained.

<Emission spectrum>
In view of the use as a green phosphor, the silicate green phosphor of the present invention preferably has the following characteristics when an emission spectrum is measured when excited with light having a peak wavelength of 400 nm or 455 nm.

First, the silicate green phosphor of the present invention has an emission peak wavelength λ _p (nm) in the above emission spectrum of usually 510 nm or more, preferably 518 nm or more, more preferably 520 nm or more, and usually 545 nm or less, preferably The range is 528 nm or less, more preferably 525 nm or less. While the color tends to be bluish green when emission peak wavelength lambda _p is too short, there is a tendency to take on too long yellowish, both in some cases the characteristics of the green light decreases.

The relative intensity of the emission peak of the silicate green phosphor of the present invention (hereinafter sometimes referred to as “relative emission peak intensity”) is usually 75 or more, preferably 85 or more, more preferably 95 or more. Incidentally, the relative emission peak intensity Kasei Optonix Ltd. _BaMgAl 10 _O 17: Eu represents the emission intensity when the (product number LP-B4) excited at 365nm as 100. A higher relative emission peak intensity is preferred.

  In addition, the silicate green phosphor of the present invention has a feature that the emission peak half width (hereinafter referred to as “FWHM” as appropriate) in the above-mentioned emission spectrum is narrow. A narrow FWHM means that the color purity is excellent, and for example, the phosphor is excellent in applications such as a backlight.

  Specifically, the FWHM of the silicate green phosphor of the present invention is usually 10 nm or more, preferably 20 nm or more, more preferably 45 nm or more, and usually 75 nm or less, preferably 70 nm or less, more preferably 65 nm or less, still more preferably. Is in the range of 60 nm or less. If the FWHM is too narrow, the luminance may decrease. On the other hand, if the FWHM is too wide, the color purity may decrease.

For example, a GaN-based light emitting diode can be used to excite the phosphor with light having a peak wavelength of 300 nm to 420 nm.
In addition, the measurement of the emission spectrum of the phosphor and the calculation of the emission peak wavelength, peak relative intensity, and peak half width are, for example, a 150 W xenon lamp as an excitation light source and a multichannel CCD detector C7041 (Hamamatsu Photonics) as a spectrum measurement device. And a fluorescence measuring apparatus (manufactured by JASCO Corporation). This measurement is performed at room temperature (for example, 25 ° C.).

<Excitation wavelength>
The silicate green phosphor of the present invention is preferably excitable with light in a wavelength range of usually 300 nm or more, particularly 350 nm or more, more preferably 380 nm or more, and usually 500 nm or less, especially 480 nm or less, more preferably 470 nm or less. . In particular, if it can be excited by light in the near ultraviolet region, it can be suitably used for a light-emitting device using a semiconductor light-emitting element having a light emission peak at 300 nm to 420 nm as a first light emitter.

  The excitation spectrum can be measured at room temperature, for example, 25 ° C., using a fluorescence spectrophotometer F-4500 type (manufactured by Hitachi, Ltd.). The excitation peak wavelength can be calculated from the obtained excitation spectrum.

<Weight median diameter>
The silicate green phosphor of the present invention preferably has a weight median diameter (D ₅₀ ) in the range of usually 10 μm or more, particularly 12 μm or more, and usually 30 μm or less, especially 25 μm or less. When the weight median diameter is too small, the luminance is lowered and the phosphor particles tend to aggregate. On the other hand, if the weight median diameter is too large, there is a tendency for coating unevenness and blockage of the dispenser to occur. The weight median diameter of the silicate green phosphor of the present invention can be measured using an apparatus such as a laser diffraction / scattering particle size distribution measuring apparatus.

[Production method]
The raw materials, production method and the like for obtaining the silicate green phosphor of the present invention are as follows.

Method for producing a silicate-based green phosphor of the present invention is not particularly limited, for example, in the formula [11], the raw material of the metal element G ^I (hereinafter appropriately referred to as "G ^I source".), A raw material (hereinafter appropriate Si "Si source"), an element G ^II raw material (hereinafter referred to as "G ^II source" as appropriate), and an element G ^III raw material (hereinafter referred to as "G ^III source" as appropriate). ”) And weighed (mixing step), and the resulting mixture (sometimes referred to as“ phosphor precursor ”) is fired under predetermined firing conditions (firing step), and if necessary It can be produced by pulverization, washing, surface treatment and the like.

<Phosphor material>
^{G I} sources used in the preparation of silicate-based green phosphor of the present invention, Si source, as the G ^II sources and G ^III source, for ^example, an oxide of each element of G I, Si, G ^II and G ^III, Examples include hydroxides, carbonates, nitrates, sulfates, oxalates, carboxylates and halides. From these compounds, the reactivity to the composite oxide, the low generation amount of NO _x , SO _{x and the} like during firing may be selected as appropriate.

(Description of ^{G I} source)
Among G ^I source, specific examples of the Ba _{source, BaO, Ba (OH) 2} · 8H 2 O, BaCO 3, Ba (NO 3) 2, BaSO 4, Ba (C 2 O 4) · 2H 2 O , Ba (OCOCH ₃ ) ₂ , BaCl _{2 and the} like. Of these, BaCO ₃ , BaCl _{2 and the} like are preferable, and BaCO ₃ is particularly preferable from the viewpoint of handling. This is because the stability in the air is good, and it is easily decomposed by heating, so that undesired elements hardly remain and it is easy to obtain high-purity raw materials.

Among G ^I source, specific examples of Ca _{source, CaO, Ca (OH) 2} , CaCO 3, Ca (NO 3) 2 · 4H 2 O, CaSO 4 · 2H 2 O, Ca (C 2 O 4) · H ₂ O, Ca (OCOCH ₃ ) ₂ · H ₂ O, anhydrous CaCl ₂ (however, it may be a hydrate) and the like. Of these, CaCO ₃ , anhydrous CaCl _{2 and the} like are preferable.

Among G ^I source, specific examples of Sr _{source, SrO, Sr (OH) 2} · 8H 2 O, SrCO 3, Sr (NO 3) 2, SrSO 4, Sr (C 2 O 4) · H 2 O , Sr (OCOCH ₃ ) ₂ · 0.5H ₂ O, SrCl _{2 and the} like. Of these, SrCO ₃ , SrCl _{2 and the} like are preferable, and SrCO ₃ is particularly preferable. This is because the stability in the air is good, it decomposes easily by heating, it is difficult for undesired elements to remain, and it is easy to obtain high-purity raw materials.

Among G ^I source, examples of Zn _{source, ZnO, Zn (C 2 O} 4) · 2H 2 O, include ZnSO ₄ · 7H ₂ O and the like.

Among G ^I source, specific examples of the Mg _{source, MgCO 3, MgO, MgSO 4} , Mg (C 2 O 4) · 2H 2 O , and the like.

These G ^I sources can be used only either one kind or as a combination of two or more kinds in any combination and in any ratio.

(Description of Si source)
Specific examples of the Si source include SiO ₂ , H ₄ SiO ₄ , Si (OCOCH ₃ ) _{4 and the} like. Of these, SiO ₂ is preferable.
Any one of these Si sources may be used, or two or more may be used in any combination and ratio.

(Description of G ^II source)
Among the G ^II sources, specific examples of Eu sources include Eu ₂ O ₃ , Eu ₂ (SO ₄ ) ₃ , Eu ₂ (C ₂ O ₄ ) ₃ , EuCl ₂ , EuCl ₃ , Eu (NO ₃ ) _3. 6H ₂ O, and the like. Of these, Eu ₂ O ₃ , EuCl _{2 and the} like are preferable.
Specific examples of the Sm source, the Tm source, the Yb source, and the like include compounds in which Eu is replaced with Sm, Tm, Yb, etc. in the respective compounds listed as specific examples of the Eu source.

Among the G ^II sources, specific examples of Mn sources include MnO, MnO ₂ , Mn ₂ O ₃ , MnF ₂ , MnCl ₂ , MnBr ₂ , Mn (NO ₃ ) ₂ .6H ₂ O, MnCO ₃ , MnCr ₂ O. ₄ etc. are mentioned.
Among the G ^II sources, specific examples of the Cr source include Cr ₂ O ₃ , CrF ₃ (may be a hydrate), CrCl ₃ , CrBr ₃ · 6H ₂ O, Cr (NO ₃ ) ₂ · 9H. ₂ O, (NH ₄ ) ₂ CrO _{4 and the} like.
Incidentally, G ^II sources can be used only either one kind or as a combination of two or more kinds in any combination and in any ratio.

(Description of G ^III source)
Of the G ^III sources, specific examples of Tb sources include Tb ₄ O ₇ , TbCl ₃ (including hydrates), TbF ₃ , Tb (NO ₃ ) ₃ .nH ₂ O, Tb ₂ (SiO ₄ ). ₃ , Tb ₂ (C ₂ O ₄ ) ₃ · 10H ₂ O, and the like. Among these, Tb ₄ O ₇ , TbCl ₃ and TbF ₃ are preferable, and Tb ₄ O ₇ is more preferable. Further, it can be used after co-precipitation with a G ^II source (for example, Eu source) and a Tb source.

Among G ^III source, specific examples of the Pr _{source, Pr 2 O 3, PrCl 3} , PrF 3, Pr (NO 3) 3 · 6H 2 O, Pr 2 (SiO 4) 3, Pr 2 (C 2 O ₄ ) ₃ · 10H ₂ O and the like. Among these, Pr ₂ O ₃ , PrCl ₃ and PrF ₃ are preferable, and Pr ₂ O ₃ is more preferable.

Among the G ^III sources, specific examples of the Ce source include CeO ₂ , CeCl ₃ , Ce ₂ (CO ₃ ) ₃ .5H ₂ O, CeF ₃ , Ce (NO ₃ ) ₃ .6H ₂ O, and the like. Of these, CeO ₂ and CeCl ₃ are preferable.

Among the G ^III sources, specific examples of the Lu source include Lu ₂ O ₃ , LuCl ₃ , LuF ₃ (may be a hydrate), and Lu (NO ₃ ) ₃ (may be a hydrate). ) And the like. Of these, Lu ₂ O ₃ and LuCl ₃ are preferable.

Of the G ^III sources, specific examples of La sources include La ₂ O ₃ , LaCl ₃ .7H ₂ O, La ₂ (CO ₃ ) ₃ .H ₂ O, LaF ₃ , La (NO ₃ ) ₃ · 6H _{2. O, La 2 (SO 4)} 3 and the like. Of _{these, La 2 O 3, LaCl 3} · 7H 2 O is preferred.

Among the G ^III sources, specific examples of Gd sources include Gd ₂ O ₃ , GdCl ₃ .6H ₂ O, Gd (NO ₃ ) ₃ .5H ₂ O, Gd ₂ (SO ₄ ) ₃ · 8H ₂ O, GdF ₃ etc. are mentioned. Among _{them, Gd 2 O 3, GeCl 3} · 6H 2 O are preferable.

Incidentally, G ^III sources can be used only either one kind or as a combination of two or more kinds in any combination and in any ratio.

(Other phosphor materials)
Depending on the composition of the objective silicate green phosphor of the present invention, compounds containing other elements may be used as raw materials.

For example, when producing a phosphor having a composition containing Ge, specific examples of the Ge source include GeO ₂ , Ge (OH) ₄ , Ge (OCOCH ₃ ) ₄ , GeCl _{4, and the} like. Of these, GeO _{2 and the} like are preferable.

For example, when producing a phosphor having a composition containing Ga, specific examples of the Ga source include Ga ₂ O ₃ , Ga (OH) ₃ , Ga (NO ₃ ) ₃ .nH ₂ O, Ga ₂ (SO ₄ ). ₃ , GaCl _{3 and the} like.

For example, when producing a phosphor composition containing Al, as a specific example of the Al source is _{α-Al 2 O 3, γ} -Al 2 O 3, Al 2 O 3 _equal, Al (OH) 3, AlOOH, _{Al (NO 3) 3 · 9H} 2 O, Al 2 (SO 4) 3, AlCl 3 and the like.

For example, when producing a phosphor having a composition containing P, specific examples of the P source include P ₂ O ₅ , Ba ₃ (PO ₄ ) ₂ , Sr ₃ (PO ₄ ) ₂ , (NH ₄ ) ₃ PO _4. Etc.

For example, when a phosphor having a composition containing B is manufactured, specific examples of the B source include B ₂ O ₃ and H ₃ BO ₃ .
Any one of these compounds containing other elements may be used, or two or more may be used in any combination and ratio.

<Mixing process>
G ^I source, Si source, method in which the mixing G ^II source and G ^III source is not particularly limited, examples, uses any known technique, such as those listed as the following (A) and (B) be able to. As for these various conditions, for example, known conditions such as mixing and using two kinds of balls having different particle diameters in a ball mill can be appropriately selected.

(A) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., pulverization using mortar and pestle, etc., mixer such as ribbon blender, V-type blender and Henschel mixer, or mortar and pestle A dry mixing method that combines mixing and pulverizing and mixing the aforementioned raw materials.

(B) After adding a solvent or dispersion medium such as water, methanol, ethanol or the like to the above-mentioned raw materials and mixing with a pulverizer, a mortar and pestle, or an evaporating dish and a stirring rod, Wet mixing method of drying by spray drying, heat drying, or natural drying.

  Moreover, you may sieve a raw material as needed at the time of the said mixing and grinding | pulverization. In this case, various commercially available sieves can be used. However, it is preferable to use a nylon mesh rather than a metal mesh in terms of preventing impurity contamination.

<Baking process>
The firing step is usually performed by filling the mixture obtained in the above-described mixing step into a heat-resistant container such as a crucible or a tray made of a material having low reactivity with each phosphor material and firing the mixture. As the material of the heat-resistant container used at the time of firing, ceramics such as alumina, quartz, boron nitride, silicon carbide, silicon nitride, magnesium oxide, metals such as platinum, molybdenum, tungsten, tantalum, niobium, iridium, rhodium, or the like An alloy containing carbon as a main component, carbon (graphite), and the like can be given. Here, the heat-resistant container made of quartz can be used for heat treatment at a relatively low temperature, that is, 1200 ° C. or less, and a preferable use temperature range is 1000 ° C. or less. Examples of such heat-resistant containers are preferably heat-resistant containers made of alumina, platinum, molybdenum, tungsten, tantalum, and the like. In particular, when a heat-resistant container made of molybdenum is used, contamination of impurities can be suppressed.
Here, when a metal carbonate is used as the phosphor raw material, firing is performed in the form of multistage firing so that the firing furnace is not damaged by the desorbed carbon dioxide, and at least primary firing (described later) is performed. It is preferable to convert a part into a metal oxide.

  The filling rate when filling the phosphor material into the heat-resistant container (hereinafter referred to as “heat-resistant container filling rate”) varies depending on the firing conditions, but the fired product is pulverized in a post-treatment step described later. It may be filled to such an extent that it does not become difficult to perform, and is usually 10% by volume or more and usually 90% by volume or less.

Further, when it is desired to increase the amount of the phosphor raw material to be processed at a time, it is preferable that heat is uniformly circulated in the heat-resistant container, for example, by decreasing the rate of temperature rise.
Moreover, it is preferable that the filling rate (hereinafter referred to as “furnace filling rate” as appropriate) when filling the heat-resistant container in the furnace is such that heat does not become uneven between the heat-resistant containers in the furnace.
Furthermore, in the above baking, when the number of heat-resistant containers in the baking furnace is large, for example, to make the heat transfer to each heat-resistant container uniform, such as slowing the temperature increase rate, It is preferable for firing without unevenness.

In the temperature raising process at the time of firing, it is preferable that a part of the temperature is reduced. Specifically, at any time when the temperature is preferably room temperature or higher, and preferably 1500 ° C. or lower, more preferably 1200 ° C. or lower, and still more preferably 1000 ° C. or lower, In general, it is preferably in the range of 10 ⁻² Pa to less than 0.1 MPa. Among them, it is preferable to introduce an inert gas or a reducing gas, which will be described later, into the system after reducing the pressure in the system, and to raise the temperature in that state.

  At this time, if necessary, it may be maintained at the target temperature for usually 1 minute or longer, preferably 5 minutes or longer, more preferably 10 minutes or longer. The holding time is usually 5 hours or less, preferably 3 hours or less, more preferably 1 hour or less.

  The temperature during firing (maximum temperature reached) is usually 850 ° C. or higher, preferably 950 ° C. or higher, and usually 1400 ° C. or lower, preferably 1350 ° C. or lower. If the firing temperature is too low, the crystal does not grow sufficiently and the particle size may be small. On the other hand, if the firing temperature is too high, the crystal grows too much and the particle size may become too large.

  The rate of temperature rise is usually 2 ° C./min or more, preferably 3 ° C./min or more, and usually 10 ° C./min or less, preferably 6 ° C./min or less. Below this range, the firing time may be longer. Moreover, when it exceeds this range, a baking apparatus, a container, etc. may be damaged.

  The pressure at the time of firing is not particularly limited because it varies depending on the firing temperature or the like, but is usually 0.01 MPa or more, preferably 0.1 MPa or more, and usually 200 MPa or less, preferably 100 MPa or less. Among these, industrially, it is usually about atmospheric pressure to about 0.3 MPa, and atmospheric pressure is preferable in terms of cost and labor.

  The firing time is not particularly limited because it varies depending on the temperature and pressure at the time of firing, but is usually 10 minutes or longer, preferably 1 hour or longer, more preferably 3 hours or longer, more preferably 4 hours or longer, and usually 24 hours. Hereinafter, it is preferably in the range of 15 hours or less.

  The atmosphere during firing is not particularly limited, but in the present invention, firing is preferably performed in an atmosphere having a low oxygen concentration as described later. The oxygen concentration at the time of firing is usually 150 ppm or less, preferably 100 ppm or less, more preferably 50 ppm or less, still more preferably 20 ppm or less, and particularly preferably 10 ppm or less. Ideally, no oxygen is present at all. As a specific example, it is carried out in an atmosphere of any one of gases such as carbon monoxide, carbon dioxide, nitrogen, hydrogen, and argon, or in a mixed atmosphere of two or more. Among these, it is preferable to contain reducing gas, such as carbon monoxide and hydrogen, and especially under a nitrogen atmosphere containing hydrogen.

  Here, the hydrogen content contained in the hydrogen-containing nitrogen atmosphere is usually 1% by volume or more, preferably 2% by volume or more, and usually 5% by volume or less, and the most preferable hydrogen content is 4% by volume. is there. This is because if the hydrogen content in the atmosphere is too high, the safety may decrease, and if it is too low, a sufficient reducing atmosphere cannot be achieved.

  Furthermore, in the present invention, during firing, the firing atmosphere is a reducing atmosphere such as a hydrogen-containing nitrogen atmosphere, and further, the oxygen concentration is lowered by making solid carbon coexist in the reaction system, etc. Although it is preferable, this will be described in detail in the following sections.

(Solid carbon)
To produce the silicate-based green phosphor of the present invention, as activation element G ^II is contributing ionic state to luminescence (valence), select the required atmosphere. For example, it is desirable that at least a part of Eu as an activating element that is one of the preferable G ^II elements that cause green light emission in the silicate green phosphor of the present invention is a divalent ion. Specifically, the proportion of Eu ²⁺ in the total Eu is preferably as high as possible, and is usually 50% or more, preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. However, a compound containing trivalent Eu ions such as Eu ₂ O ₃ is usually used as a raw material for Eu. Therefore, in order to obtain a phosphor that contains Eu ²⁺ that is a divalent ion and emits green light, conventionally, in order to reduce the trivalent ion Eu ³⁺ to the divalent ion Eu ²⁺ , carbon monoxide and hydrogen-containing nitrogen are used. In general, firing is performed in some reducing atmosphere such as hydrogen. However, even in these firing atmospheres, oxygen derived from raw materials and the like is contained, so that it has been difficult to sufficiently reduce the oxygen concentration. In addition, when Sm, Tm, Yb or the like is used as the G ^II element, there are the same problems as in the case of Eu described above.

As a result of the study, the inventors have reduced the trivalent ion of the G ^II element to the divalent ion and simultaneously introduced it into the host crystal, under the condition that solid carbon coexists in addition to the normal reducing atmosphere (that is, It has been found that firing under conditions with a stronger reducing power is effective. As a result, the obtained phosphor has the characteristics that it emits light with high brightness in the wavelength range of usually 510 nm or more and 542 nm or less as described above, and at the same time, the emission spectrum width is narrow.

Moreover, the object color of the is considered to have become an indicator of reduction degree of G ^II elements. By firing in a strong reducing atmosphere, the G ^II element is sufficiently reduced, and the phosphor represented by the formula [11] is considered to have an object color in the above range.

  The type of solid carbon is not particularly limited, and any type of solid carbon can be used. Examples thereof include carbon black, activated carbon, pitch, coke, graphite (graphite) and the like. The reason why it is preferable to use solid carbon is that oxygen in the firing atmosphere reacts with the solid carbon to generate carbon monoxide gas, and this carbon monoxide reacts with oxygen in the firing atmosphere to form carbon dioxide. This is because the oxygen concentration in the firing atmosphere can be reduced. Among the above-mentioned examples, activated carbon having high reactivity with oxygen is preferable. The shape of the solid carbon includes powder, bead, particle, block, etc., but is not particularly limited.

  The amount of solid carbon to coexist depends on the amount of raw materials to be treated at one time and other firing conditions, but from the viewpoint of the balance between the characteristics and productivity of the phosphor, it is usually 0.1% by weight or more The content is preferably 1% by weight or more, more preferably 10% by weight or more, and still more preferably 15% by weight or more.

Further, by using a graphite crucible as a firing container, it is possible to obtain the same effect as the coexistence of solid carbon. On the other hand, when a crucible made of a material other than carbon such as an alumina crucible is used, it is preferable that solid carbon such as graphite beads, granules and blocks coexist separately.
Note that firing is preferably performed under sealed conditions, such as by covering the crucible.

  Note that the firing in the coexistence of solid carbon is sufficient if the phosphor raw material and the solid carbon are present in the same firing container, and it is preferable to arrange them close to each other. Here, the phosphor raw material and solid carbon may be mixed and fired. In general, when carbon is mixed into the phosphor product, black carbon absorbs light emitted from the phosphor, so that the luminous efficiency of the phosphor is often lowered, so care must be taken.

  As a method of arranging the solid carbon in close proximity, the solid carbon is put in a container different from the container containing the phosphor raw material, and these containers are placed in the same crucible (for example, the solid carbon container on the upper part of the raw material container). Specific methods such as placing a solid carbon container in the phosphor material, or placing the solid carbon around the phosphor material powder container. For example. When a large crucible is used, it is preferable to take a method in which a container containing solid carbon is placed in the same container as the phosphor raw material and fired. In any case, it is preferable to devise so that solid carbon is not mixed in the phosphor material.

As a technique for obtaining a divalent ion of the G ^II element, in addition to the above-described technique for coexisting solid carbon, or in place of the technique for coexisting solid carbon, the following technique may be implemented. That is, it is preferable to remove the air present in the crucible at the same time as the raw material powder as much as possible to lower the oxygen concentration. As a specific method, it is preferable to depressurize a crucible charged with a predetermined raw material in a vacuum furnace to remove air, and introduce an atmospheric gas used during firing to restore the pressure. Further, it is more preferable to repeat this operation. Alternatively, an oxygen getter such as Mo can be used as necessary. Further, if safety measures are taken, divalent ions of the G ^II element can also be obtained by firing in a nitrogen atmosphere containing 5% by volume or more of hydrogen.

  The presence of solid carbon in this manner is preferable because the oxygen concentration in the firing atmosphere is reduced and the firing atmosphere is made a highly reducing atmosphere, whereby a phosphor with high characteristics can be obtained.

(flux)
In the firing step, it is preferable that a flux coexists in the reaction system from the viewpoint of growing good crystals. The type of the flux is not particularly limited, but a compound containing a monovalent element or atomic group and a -1 valent element, a compound containing a monovalent element or atomic group and a -3 valent element or atomic group, Compound containing divalent element and −1 valent element, compound containing 2 valent element and -3 valent element or atomic group, compound containing 3 valent element and −1 valent element In addition, it is preferable to use as the flux a compound selected from the group consisting of a trivalent element and a compound containing a trivalent element or an atomic group.

The monovalent element or atomic group is preferably, for example, at least one element selected from the group consisting of an alkali metal element and an ammonium group (NH ₄ ), and is cesium (Cs) or rubidium (Rb). Is more preferable.
The divalent element is preferably, for example, at least one element selected from the group consisting of an alkaline earth metal element and zinc (Zn), and more preferably strontium (Sr) or barium (Ba). preferable.
The trivalent element is preferably at least one element selected from the group consisting of rare earth elements such as lanthanum (La), yttrium (Y), aluminum (Al), and scandium (Sc). (Y) or aluminum (Al) is more preferable.
The -1 valent element is preferably, for example, at least one element selected from the group consisting of halogen elements, and is preferably chlorine (Cl) or fluorine (F).
The −3 element or atomic group is preferably, for example, a phosphate group (PO ₄ ).

  Among the above, the flux is a trivalent selected from the group consisting of alkali metal halides, alkaline earth metal halides, zinc halides, yttrium (Y), aluminum (Al), scandium (Sc), and rare earth elements. Selected from the group consisting of elemental halides, alkali metal phosphates, alkaline earth metal phosphates, zinc phosphate, yttrium (Y), aluminum (Al), lanthanum (La), and scandium (Sc) It is preferable to use a compound selected from the group consisting of phosphates of trivalent elements.

More specifically, the flux preferably used is NH ₄ Cl, LiCl, NaCl, KCl, CsCl, CaCl ₂ , BaCl ₂ , SrCl ₂ , YCl ₃ · 6H ₂ O (however, even if it is an anhydrous product) ZnCl ₂ , MgCl ₂ .6H ₂ O (but may be anhydrous), chlorides such as RbCl, LiF, NaF, KF, CsF, CaF ₂ , BaF ₂ , SrF ₂ , Fluorides such as AlF ₃ , MgF ₂ , YF ₃ , K ₃ PO ₄ , K ₂ HPO ₄ , KH ₂ PO ₄ , Na ₃ PO ₄ , Na ₂ HPO ₄ , NaH ₂ PO ₄ , Li ₃ PO ₄ , Li ₂ Examples thereof include phosphates such as HPO ₄ , LiH ₂ PO ₄ , (NH ₄ ) ₃ PO ₄ , (NH ₄ ) ₂ HPO ₄ , and (NH ₄ ) H ₂ PO ₄ .

Among these, LiCl, CsCl, BaCl ₂ , SrCl ₂ , and YF ₃ are preferably used, and CsCl and SrCl ₂ are particularly preferably used.

  Here, it is preferable to use an anhydride for the above-mentioned flux having deliquescence, and when the phosphor is produced by multi-stage firing, it is preferred to use the flux at the later stage firing.

  These fluxes may use only 1 type and may use 2 or more types together by arbitrary combinations and ratios, but the following effects will be acquired when it uses 2 or more types in combination.

  Although it varies depending on the type of flux, firing conditions, and the like, generally, when the flux is allowed to coexist in the phosphor material, crystal growth of the phosphor is promoted and a phosphor having a large particle size tends to be obtained. Further, the silicate green phosphor of the present invention tends to have higher luminance as the particle size increases. From the above, when the flux is allowed to coexist in the phosphor raw material, it seems that the brightness is improved, but it seems preferable. However, if the particle size is too large, the handling property is deteriorated, such as coating unevenness or clogging of the dispenser. There is a tendency.

In the case where two or more kinds of fluxes are used in combination, among the above-mentioned fluxes, when a compound containing a divalent element such as SrCl ₂ or BaCl ₂ is used as the flux, there is a crystal growth promoting action, Among the fluxes, it has been clarified that when a compound containing a monovalent or trivalent element such as CsCl, LiCl, YCl ₃ .6H ₂ O is used as the flux, there is an effect of suppressing crystal growth. Therefore, when a flux having a crystal growth promoting action and a flux having a crystal growth inhibiting action are used in combination, the weight median that is easy to handle and has high brightness and crystal growth is suppressed due to the synergistic effect of both fluxes. Since a phosphor having a diameter (specifically, 10 μm or more and 25 μm or less) can be obtained, it is particularly preferable.

Preferred combinations when two or more kinds of fluxes are used in combination include SrCl ₂ and CsCl, SrCl ₂ and LiCl, SrCl ₂ and YCl ₃ .6H ₂ O, SrCl ₂ and BaCl ₂ and CsCl, etc. Among them, SrCl 2 It is particularly preferable to use ₂ and CsCl in combination.

  The amount of flux used (the total amount used when two or more fluxes are used in combination) varies depending on the type of raw material, the material of the flux, the firing temperature, the atmosphere, etc., but is usually 0.01 relative to the raw material mixture. It is preferably in the range of not less than wt%, more preferably not less than 0.1 wt%, usually not more than 20 wt%, more preferably not more than 10 wt%. If the amount of flux used is too small, the effect of flux may not appear. If the amount of flux used is too large, the flux effect may be saturated, the particle size will be too large, the handleability will be poor, it will be incorporated into the host crystal and the emission color may be changed, or the brightness may be reduced. .

  Moreover, when using in combination of 2 or more types of flux, the use ratio (molar ratio) of the compound containing a monovalent or trivalent element is 1 when the number of moles of the compound containing a divalent element is 1. It is usually 0.1 or more, preferably 0.2 or more, and usually 10 or less, preferably 5 or less.

Note that when an appropriate amount of a preferable flux such as SrCl ₂ is used, the present invention can be used even in a weak reducing atmosphere in which solid carbon does not coexist (for example, in a nitrogen atmosphere containing nitrogen (nitrogen: hydrogen = 96: 4 (volume ratio)). The silicate green phosphor can be obtained.

(Primary firing and secondary firing)
The firing step is divided into primary firing and secondary firing, and the raw material mixture obtained by the mixing step is first primarily fired, and then pulverized again with a ball mill or the like and then subjected to secondary firing under the above-mentioned firing conditions. Good.

  The primary firing temperature (maximum temperature reached) is usually 850 ° C. or higher, preferably 1000 ° C. or higher, more preferably 1050 ° C. or higher, and usually 1350 ° C. or lower, preferably 1200 ° C. or lower, more preferably 1150 ° C. or lower. It is.

  The temperature increase rate of primary firing is usually 2 ° C./min or more, preferably 3 ° C./min or more, and usually 10 ° C./min or less, preferably 5 ° C./min or less. Below this range, the firing time may be longer. Moreover, when it exceeds this range, a baking apparatus, a container, etc. may be damaged.

  The pressure during primary firing is not particularly limited because it varies depending on the firing temperature and the like, but is usually 0.01 MPa or more, preferably 0.1 MPa or more, and usually 200 MPa or less, preferably 100 MPa or less. Among these, industrially, it is usually about atmospheric pressure to about 0.3 MPa, and atmospheric pressure is preferable in terms of cost and labor.

  The atmosphere during the primary firing is not particularly limited, and may be performed in an atmosphere having a low oxygen concentration as described above. It does not necessarily have to be in an atmosphere having a low oxygen concentration or in a reducing atmosphere. For example, it may be performed in an inert atmosphere such as nitrogen or argon. However, the emission intensity may decrease when performed in an oxygen atmosphere.

  The primary firing time is usually in the range of 1 hour or longer, preferably 2 hours or longer, more preferably 4 hours or longer, and usually 24 hours or shorter, preferably 15 hours or shorter, more preferably 13 hours or shorter.

  The conditions such as the temperature and time of the secondary firing are basically the same as the conditions described in the above-mentioned columns (Baking conditions), (Solid carbon) and (Flux).

The flux may be mixed before the primary firing or may be mixed before the secondary firing.
Also, the firing conditions such as the atmosphere may be changed between the primary firing and the secondary firing.

1-2-2-2. (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, Mn phosphor [composition]
The light-emitting device of the present invention includes a barium aluminate-based green phosphor represented by (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, Mn as a green phosphor (hereinafter referred to as “barium aluminate-based green fluorescence of the present invention”). May be referred to as "body"). Among them, it is preferable to use a phosphor whose composition is represented by the following formula [12], and more preferably a phosphor having the characteristics described below. A phosphor represented by the following formula [12] and having the characteristics described later can be manufactured by a manufacturing method described later.

_{(1-z) Ba (1} -efg) Sr e Ca f Eu g Mg (1-hi) Zn h Mn i Al j O k
_{· (Z) Ba (0.75-} e'-f'-g ') Sr e' Ca f 'Eu g' Al 11 O 17.25 · D m ... [12]
(However, D represents at least one alkali metal element,
z, e, f, g, h, i, j, k, m, e ′, f ′, g ′ are respectively
0 ≦ z ≦ 1,
0 ≦ e <1,
0 ≦ f <1,
0.1 <g <1,
0 ≦ h <1,
0 ≦ i ≦ 1,
9 ≦ j ≦ 11,
16 ≦ k ≦ 18,
0 ≦ m ≦ 0.02,
0 ≦ e ′ <1,
0 ≦ f ′ <1,
0.1 <g ′ <1
Represents a number that satisfies )

  In formula [12], D represents an alkali metal element. The alkali metal element is as described later.

  z is usually 0 or more, and usually 1 or less, preferably 0.4 or less, more preferably 0.2 or less, and particularly preferably z = 0.

  e is usually 0 or more, and usually less than 1, preferably less than 0.55, more preferably less than 0.5, and still more preferably less than 0.45.

  f is usually 0 or more, and usually less than 1, preferably less than 0.5, more preferably less than 0.45, and still more preferably less than 0.35.

  g is usually larger than 0.1, preferably 0.2 or more, more preferably 0.25 or more, and usually less than 1, preferably 0.7 or less, more preferably 0.6 or less.

  h is usually 0 or more, and usually less than 1, preferably 0.4 or less, more preferably 0.3 or less, and still more preferably 0.15 or less.

  i is usually 0 or more, preferably more than 0, more preferably 0.05 or more, further preferably 0.1 or more, particularly preferably 0.15 or more, and usually 1 or less, preferably 0.7 or less, More preferably, it is 0.6 or less, More preferably, it is 0.5 or less.

  j is usually 9 or more, preferably 9.5 or more, and usually 11 or less, preferably 10.5 or less, and particularly preferably g = 10.

  k is usually 15.3 or more, preferably 16 or more, and usually 18.7 or less, preferably 18 or less, particularly preferably h = 17.

  e 'is usually 0 or more, and usually less than 1, preferably less than 0.5, more preferably less than 0.45.

  f 'is usually 0 or more, and usually less than 1, preferably less than 0.5, more preferably less than 0.45.

  g 'is usually greater than 0, preferably greater than 0.1, more preferably 0.2 or more, and usually less than 1, preferably 0.7 or less, more preferably 0.6 or less.

  m is usually 0 or more, preferably 0.001 or more, more preferably 0.002 or more, and usually 0.02 or less, preferably 0.015 or less, more preferably 0.01 or less, still more preferably 0.00. 005 or less.

[Crystal structure]
The barium aluminate green phosphor of the present invention preferably has a β-alumina structure.

A representative material having a β-alumina structure, which is a preferable crystal structure of the barium aluminate-based green phosphor of the present invention, is BaMgAl ₁₀ O ₁₇ . The BaMgAl ₁₀ O ₁₇ crystal has a hexagonal crystal system, a P6 ₃ / mmc space group, and a BaO layer sandwiched between an Al ₂ O ₃ layer and an MgAl ₂ O ₄ layer. Take. Eu ²⁺ , Sr ²⁺ and Ca ²⁺ can replace the lattice position of Ba ^{2+ in} a wide composition range. Mn ²⁺ and Zn ²⁺ can replace the lattice position of Mg ^{2+ in} a wide composition range. The Mg ²⁺ site has a tetracoordinate oxygen coordination structure, and the crystal field formed by this coordination structure is thought to contribute to green light emission.

A Ba _0.75 Al ₁₁ O _17.25 Eu-activating material obtained by substituting Mg in BaMgAl ₁₀ O ₁₇ with Al and a part of Ba with O is known as a blue phosphor. BaMgAl ₁₀ O ₁₇ : Eu It has been known that it has a light emission characteristic similar to that of a phosphor and forms a solid solution by solid solution with each other. From the above viewpoint, the preferable composition of the barium aluminate green phosphor of the present invention is represented by the above formula [12].

In particular, when the barium aluminate green phosphor of the present invention has a composition represented by the above formula [12] and Z is not 0 or 1, the barium aluminate green phosphor of the present invention is _{Ba (1-efg) Sr e} Ca f Eu g Mg (1-hi) Zn h Mn i Al j O and terms represented by _{k, Ba (0.75-e'-} f'-g ') Sr e' Ca The barium aluminate-based green phosphor of the present invention is a solid solution in which these terms form a uniform crystal phase, although it has terms represented by _{f ′} Eu _{g ′} Al ₁₁ O _17.25 · D _m. It may also be a mixture of different crystalline phases consisting of these terms.

[Emission spectrum]
In view of the use as a green phosphor, the barium aluminate-based green phosphor of the present invention, when measuring an emission spectrum when excited with light in a wavelength range of 380 nm to 400 nm, particularly light with a wavelength of 400 nm, It preferably has the following characteristics.

<Peak emission wavelength>
When the barium aluminate green phosphor of the present invention is used as a green phosphor, the emission peak wavelength λp (nm) in an emission spectrum obtained by excitation with light in the above wavelength range is usually 510 nm or more, preferably 515 nm. As described above, it is desirable that it exists in a range of 518 nm or more, usually 545 nm or less, preferably 540 nm or less, more preferably 535 nm or less. If the emission peak wavelength λp is too short, the emission color tends to deviate from green and blue-green, and if the emission peak wavelength λp is too long, the emission color tends to deviate from green and yellow-green.

<Luminescence peak half width>
The barium aluminate-based green phosphor of the present invention has a full width at half maximum (hereinafter referred to as “FWHM” as appropriate) of the emission peak in the above-mentioned emission spectrum, usually 45 nm or more, and usually 70 nm or less. The thickness is preferably 60 nm or less, more preferably 55 nm or less. If the FWHM is too wide, the color purity may decrease. The lower limit of the FWHM is not limited, but if the FWHM is too narrow, the luminance may decrease, so it is usually 3 nm or more, preferably 4 nm or more.

<Intensity ratio of blue emission peak to green emission peak>
In addition, the barium aluminate green phosphor of the present invention is a phosphor (green phosphor) mainly having light emission in the green region, particularly when both Eu and Mn are contained. In this case, in addition to the emission peak existing in the green wavelength region, there may be an emission peak existing in another wavelength region (mainly the blue wavelength region).

<Excitation spectrum>
The barium aluminate green phosphor of the present invention preferably has the following characteristics when the excitation spectrum is measured.

(Decrease rate of I (400) with respect to I (340))
In the barium aluminate-based green phosphor of the present invention, the emission intensity I (340) at an excitation wavelength of 340 nm and the emission intensity I (400) at an excitation wavelength of 400 nm in the excitation spectrum satisfy the following formula [13]. Is preferred.
0 ≦ [{I (340) −I (400)} / I (340)] × 100 ≦ 29 (13)

  The maximum point of the excitation spectrum of the barium aluminate green phosphor of the present invention is approximately in the vicinity of a wavelength of 340 nm. That is, the above equation [13] is that the rate of decrease of the excitation spectrum intensity (I (400)) at a wavelength of 400 nm with respect to the excitation spectrum intensity near the maximum point of the excitation spectrum (I (340)) is low. This shows that the excitation spectrum intensity around the wavelength of 400 nm is high. A phosphor having a high excitation spectrum intensity around a wavelength of 400 nm is preferable because it has excellent luminous efficiency when a near-ultraviolet LED is used as an excitation light source.

Specifically, the upper limit of the value of [{I (340) −I (400)} / I (340)] × 100 in the above formula [13] is preferably as small as possible, but is usually 29 or less, preferably 26. Below, it is desirable that it is 23 or less.
On the other hand, the lower limit of the value of [{I (340) −I (400)} / I (340)] × 100 is not limited, but is usually 0 or more.

(Change rate of I (390) with respect to I (382))
In the barium aluminate green phosphor of the present invention, the emission intensity I (382) at an excitation wavelength of 382 nm and the emission intensity I (390) at an excitation wavelength of 390 nm in the excitation spectrum satisfy the following formula [14]. Is desirable.
0 ≦ | [{I (382) −I (390)} / I (382)] | × 100 ≦ 3.1
... [14]

  The above formula [14] indicates that the rate of change of the excitation spectrum intensity (I (390)) at a wavelength of 390 nm is low with respect to the excitation spectrum intensity (I (382)) at a wavelength of 382 nm, and hence the wavelength from 382 nm to 390 nm. It represents that the shape of the excitation spectrum in the range is flat. This wavelength range from 382 nm to 390 nm is an excitation wavelength mainly used for near ultraviolet excitation. Therefore, a phosphor having a flat excitation spectrum in this wavelength range is preferable because a decrease in emission intensity and a color shift hardly occur when a near-ultraviolet LED is used as an excitation light source.

Specifically, the upper limit of the value of | [{I (382) −I (390)} / I (382)] | × 100 in the above formula [14] is preferably as small as possible, but is usually 3.1 or less. Preferably, it is 2.5 or less, more preferably 2 or less, and still more preferably 1.5 or less.
On the other hand, the lower limit of the value of | [{I (382) −I (390)} / I (382)] | × 100 is not limited, but is usually 0 or more.

  The excitation spectrum of the barium aluminate-based green phosphor of the present invention is measured, for example, with a 150 W xenon lamp as an excitation light source and a fluorescence measurement apparatus equipped with a multichannel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measurement apparatus. (Manufactured by JASCO Corp.). The excitation spectrum is measured at a temperature of 25 ° C.

[Weight median diameter]
The weight median diameter (D ₅₀ ) of the barium aluminate green phosphor of the present invention is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 0.1 μm or more, preferably 0.5 μm or more, and usually It is desirable that the thickness be 30 μm or less, preferably 20 μm or less. When the weight median diameter is too small, the luminance is lowered and the phosphor particles tend to aggregate. On the other hand, if the weight median diameter is too large, there is a tendency for coating unevenness and blockage of the dispenser to occur. The weight median diameter of the barium aluminate green phosphor of the present invention can be measured using an apparatus such as a laser diffraction / scattering particle size distribution measuring apparatus.

Among the barium aluminate green phosphors of the present invention, in particular, with respect to the phosphor represented by the general formula [12], the primary particles of the phosphor are usually hexagonal prisms, Become.
The height of the hexagonal column represents the thickness of the crystal lattice in the c-axis direction, and the average thickness in the c-axis direction is preferably 3.3 μm or more, more preferably 4 μm or more, and still more preferably 4.4 μm or more. In measuring the average thickness, SEM (scanning electron microscope) is usually used. Specifically, since the hexagonal cylinders of a large number of primary particles on the SEM image are directed in various directions, the projection method determines the length of the three adjacent sides of the hexagon and the height of the hexagonal cylinder. Using the principle, the actual height of the hexagonal column is obtained.

  When performing the above measurement, it is desirable to perform measurement on particles of usually 10 or more, preferably 30 or more, more preferably 100 or more, and still more preferably 300 or more. It is also related to the ratio to crystal grains. Ideally, the measurement should be performed for all particles, but it is usually 15% or more, preferably 30% or more, more preferably 50% or more, and even more preferably 80% or more based on the total number of particles. What is necessary is just to measure about a small number.

[Production method]
The production method of the barium aluminate-based green phosphor of the present invention is not particularly limited. For example, the raw materials of each element constituting the phosphor are pulverized and mixed (pulverization / mixing step), and the resulting mixture (hereinafter referred to as the following) It may be referred to as “phosphor precursor”) by firing (firing step).
In the following description, the raw material of each element constituting the barium aluminate-based green phosphor of the present invention is represented by adding “source” to the atomic symbol of the element. For example, an Al raw material is expressed as “Al source”. These raw materials may be collectively referred to as “raw materials for each element”.

<Raw material>
As the raw material for the barium aluminate-based green phosphor of the present invention, a raw material for each element constituting the phosphor is used. The combination and ratio of the raw materials for each element to be used are not limited and can be appropriately selected according to the composition of the target phosphor.

Examples of raw materials for each element used in the production of the barium aluminate-based green phosphor of the present invention include oxides, hydroxides, carbonates, nitrates, sulfates, oxalates, carboxylates of each element, And halides. Of these compounds, it is appropriately selected in consideration of reactivity to the composite oxide and low generation amount of nitrogen oxide (NO _x ) and sulfur oxide (SO _x ) during firing. That's fine.

  Specific examples of raw materials for each element are listed as follows for each element type.

Specific examples of the Al source include Al ₂ O ₃ , Al (OH) ₃ , AlOOH, Al (NO ₃ ) ₃ .9H ₂ O, Al ₂ (SO ₄ ) ₃ , Al ₂ Cl _{3 and the} like. Among them, _{Al 2 O 3, Al (NO} 3) 3 · 9H 2 O and the like are preferable.

Specific examples of the Ba source include BaO, Ba (OH) ₂ .8H ₂ O, BaCO ₃ , Ba (NO ₃ ) ₂ , BaSO ₄ , Ba (OCO) ₂ .2H ₂ O, Ba (OCOCH ₃ ) ₂ , BaCl _2, and the like. Of these, Ba (OH) ₂ .8H ₂ O, Ba (NO ₃ ) ₂ , BaCO _{3 and the} like are preferable.

Specific examples of the Sr source include SrO, Sr (OH) ₂ .8H ₂ O, SrCO ₃ , Sr (NO ₃ ) ₂ , SrSO ₄ , Sr (OCO) ₂ .H ₂ O, Sr (OCOCH ₃ ) _2. 0.5H ₂ O, SrCl _{2 and the} like can be mentioned. Of these, SrCO ₃ , Sr (NO ₃ ) ₂ , Sr (OH) ₂ .8H ₂ O and the like are preferable.

Specific examples of the Eu source include Eu ₂ O ₃ , Eu ₂ (SO 4) ₃ , Eu ₂ (OCO) ₆ , EuCl ₂ , EuCl ₃ , EuF ₃ , Eu (NO ₃ ) ₃ · 6H ₂ O, and the like. . Of these, Eu ₂ O ₃ , EuF ₃ , EuCl _{3 and the} like are preferable.

Specific examples of the Mn source include Mn (NO ₃ ) ₂ .6H ₂ O, MnO ₂ , Mn ₂ O ₃ , Mn ₃ O ₄ , MnO, Mn (OH) ₂ , MnCO ₃ , Mn (OCOCH ₃ ) _2. 2H ₂ O, Mn (OCOCH ₃ ) ₃ .nH ₂ O, MnCl ₂ .4H ₂ O, and the like can be given. Of these, MnCO ₃ , Mn (NO ₃ ) ₂ .6H ₂ O, MnO and the like are preferable.

Specific examples of the Mg source include Mg (OH) ₂ , Mg (NO ₃ ) ₂ .6H ₂ O, Mg (OCOCH ₃ ) ₂ .4H ₂ O, MgCl ₂ , MgCO ₃ , basic magnesium carbonate, MgO, MgSO ₄ , Mg (C ₂ O ₄ ) · 2H ₂ O, and the like. Of these, MgCO ₃ , basic magnesium carbonate, MgO and the like are preferable.

Specific examples of the Ca source include CaO, Ca (OH) ₂ , CaCO ₃ , Ca (NO ₃ ) ₂ .4H ₂ O, CaSO ₄ .2H ₂ O, Ca (OCO) ₂ .H ₂ O, and Ca (OCOCH). ₃ ) ₂ · H ₂ O, CaCl _{2 and the} like. Of these, CaCO ₃ , Ca (NO ₃ ) ₂ .4H ₂ O, CaCl _{2 and the} like are preferable.

Specific examples of the Zn source include ZnO, ZnF ₂ , ZnCl ₂ , Zn (OH) ₂ , Zn (C ₂ O ₄ ) · 2H ₂ O, ZnSO ₄ · 7H ₂ O, and the like.

  As the raw materials for these elements, any one of these elements may be used alone, or two or more may be used in any combination and ratio.

<Crushing and mixing process>
The method of pulverizing and mixing the raw materials of each element is not particularly limited, but examples include the following methods (A) and (B).

(A) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., or pulverization using mortar and pestle, etc. and mixer such as ribbon blender, V-type blender, Henschel mixer, or mortar and pestle A dry method that combines mixing and pulverizing and mixing raw materials such as raw materials for each element. In this method, the raw materials of each element may be pulverized and mixed, mixed and then pulverized, or pulverization and mixing may be performed simultaneously.

(B) A solvent or dispersion medium such as water is added to the raw materials of each element, and pulverized and mixed using a wet pulverizer such as a medium stirring pulverizer, a mortar and pestle, an evaporating dish and a stirring bar, or A wet method in which the raw materials of each element are pulverized by a dry pulverizer and then mixed in a medium such as water to form a solution or slurry and then dried by spray drying, heat drying, or natural drying. .

  Among these pulverization / mixing methods, a method using a liquid medium is preferred, particularly for the raw material of the element that becomes the luminescent center ion, since it is desired to mix and disperse a small amount of the compound uniformly throughout. From the point that uniform mixing can be obtained as a whole for the raw materials of other elements, the (B) wet method is preferable. In addition, although it does not restrict | limit as a medium (solvent or a dispersion medium) of a wet method, Water or ethanol etc. are preferable.

<Baking process>
(Baking conditions)
The obtained mixture is filled in a heat-resistant container such as a crucible or a tray made of a material having low reactivity with each phosphor raw material. Examples of the material of the heat-resistant container used at the time of firing include ceramics such as alumina, quartz, boron nitride, silicon nitride, silicon carbide, magnesium, mullite, metals such as platinum, tungsten, tantalum, niobium, iridium, rhodium, Or the alloy which has them as a main component, carbon (graphite), etc. are mentioned. Here, the heat-resistant container made of quartz can be used for heat treatment at a relatively low temperature, that is, 1200 ° C. or less, and a preferable use temperature range is 1000 ° C. or less.
Examples of such heat-resistant containers are preferably heat-resistant containers made of alumina, silicon nitride, platinum, tungsten, or tantalum.

Although the atmosphere at the time of baking is not restrict | limited, Usually, the atmosphere of 1 type gas or 2 or more types of mixed gas is used among air | atmosphere, oxygen, carbon monoxide, a carbon dioxide, nitrogen, hydrogen, argon etc.
The atmosphere during firing is the reactivity to oxides, hydroxides, carbonates, basic carbonates, nitrates, sulfates, oxalates, carboxylates, halides, etc. that are the raw materials of each element, and during firing In consideration of non-generation of NO _x , SO _x, etc. Among them, it is preferable to select an atmosphere necessary for obtaining an ion state (valence) in which the element of the emission center ion contributes to light emission.
In particular, when producing a phosphor containing divalent Eu or the like as the barium aluminate green phosphor of the present invention, a neutral or reducing atmosphere such as carbon monoxide, nitrogen, hydrogen, or argon is preferable. Even under an oxidizing atmosphere such as air or oxygen, the conditions can be selected.
Firing in a carbon monoxide atmosphere is performed, for example, by setting carbon powder such as graphite or carbon, or carbon cube or the like in the vicinity of the phosphor raw material, or by introducing carbon monoxide gas into the furnace and firing. It is possible to implement it.

  The temperature during firing is usually 1200 ° C. or higher, preferably 1400 ° C. or higher, more preferably 1500 ° C. or higher, and usually 1750 ° C. or lower, preferably 1700 ° C. or lower, more preferably 1650 ° C. or lower. If the firing temperature is too low, the crystals may not grow sufficiently and the particle size may become too small, whereas if the firing temperature is too high, the crystals may grow excessively and the particle size may become too large. .

  The pressure during firing varies depending on the firing temperature or the like, but is usually at or above normal pressure.

  The firing time varies depending on the temperature and pressure during firing, but is usually 0.5 hours or longer, preferably 1 hour or longer. The firing time is preferably longer, but is usually 100 hours or shorter, preferably 50 hours or shorter, more preferably 24 hours or shorter, and further preferably 12 hours or shorter.

(flux)
When firing the above-mentioned mixture of raw materials of each element (phosphor precursor), a monovalent metal element halide may coexist at a predetermined concentration as a flux in the reaction system. By firing the phosphor precursor under the condition that the compound is present at a predetermined concentration, even when excited by near ultraviolet light, stable high emission intensity and luminance can be obtained, and temperature characteristics are also excellent. A phosphor can be obtained.

Examples of monovalent metal elements (alkali metal elements) include K (potassium), Na (sodium), Li (lithium), Cs (cesium), and Rb (rubidium). Of these, K, Na, and Li are preferable, and K and Na are more preferable.
Examples of the halogen element include fluorine (F), chlorine (Cl), bromine (Br), iodine (I) and the like. Of these, F and Cl are preferable, and F is more preferable.

  Specific examples of monovalent metal element halides include KF (potassium fluoride), NaF (sodium fluoride), LiF (lithium fluoride), CsF (cesium fluoride), RbF (rubidium fluoride), and the like. Can be mentioned. Among these, KF, NaF, and LiF are preferable, and KF and NaF are more preferable. Any one of these monovalent metal element halides may be used alone, or two or more thereof may be used in any combination and ratio.

The amount of the monovalent metal element halide used is usually more than 0% by weight, preferably 0.05% by weight or more, more preferably 0.1% by weight or more, and still more preferably, in a ratio to the phosphor precursor. It is 0.2% by weight or more, usually less than 1% by weight, preferably 0.95% by weight or less, more preferably 0.9% by weight or less.
However, as described later, in addition to monovalent metal element halides, other valence metal element halides (for example, divalent and trivalent metal element halides described later) are used in combination. The above-mentioned effects can be obtained even when the amount of monovalent metal element halide used is smaller.

Specifically, when firing is performed under a condition in which a halide of a metal element having a different value (a value other than a monovalent value) coexists with a phosphor precursor in an amount of 0.15% by weight or more, The amount of halide used is generally greater than 0% by weight, preferably 0.04% by weight or more, more preferably 0.08% by weight or more, and even more preferably 0.13% by weight or more, as a ratio to the phosphor precursor. Also, it is usually less than 1% by weight, preferably 0.95% by weight or less, more preferably 0.9% by weight or less.
If the amount of monovalent metal element halide used is too small, the luminous efficiency of the resulting phosphor may not be sufficiently improved. If the amount of monovalent metal element halide used is too large, the temperature characteristics of the resulting phosphor may deteriorate.
When two or more kinds of monovalent metal element halides are used in combination, the total use amount thereof satisfies the above range.

As described above, in the firing step, a monovalent metal element halide is allowed to coexist with the phosphor precursor at a lower concentration than in the past, so that even when excited with near-ultraviolet light, the phosphor precursor is stable. It is possible to obtain a phosphor (the phosphor of the present invention) having high emission intensity and luminance and excellent temperature characteristics.
The reason why such an effect is obtained is not clear, but according to the inventors' estimation, the crystal grows well, thereby increasing the intensity of the excitation spectrum and / or the monovalent metal element. It is considered that the substitution of a part of the Ba or Mg site causes a change in the amount of lattice defects and promotes each process up to green light emission. At this time, for example, when Na is used as the monovalent metal element, NaAlF ₄ , NaBaF _3, or the like is generated as an intermediate product, which may be effective.

In addition to the above-mentioned monovalent metal element halide, the flux of the phosphor precursor firing is preferably a divalent metal element halide such as BaF ₂ or MgF ₂ (preferably divalent metal element fluorine). Compound) or a halide of a trivalent metal element described later may be used in combination. The type of these halides is not limited.

Examples of the trivalent metal element include rare earth elements such as La (lanthanum), Y (yttrium), Al (aluminum), and Sc (scandium). Among these, Al is preferable.
Examples of trivalent metal element halides include AlF3 (aluminum fluoride), Al
Examples include Cl3 (aluminum chloride). Any one of these may be used alone, or two or more may be used in any combination and ratio.

  When using a halide of a metal element having another value (a value other than 1), the amount used is usually greater than 0% by weight, preferably 0.05% by weight or more, as a ratio to the phosphor precursor. It is preferably 0.1% by weight or more, more preferably 0.2% by weight or more, and usually 15% by weight or less, preferably 10% by weight or less, more preferably 7% by weight or less. If the amount of other-valent metal element halide used is too large, the effect of improving the luminous efficiency in near-ultraviolet excitation may not be obtained. When two or more kinds of other-valent metal element halides are used in combination, the total use amount thereof satisfies the above range.

(Primary firing and secondary firing)
The firing step may be divided into primary firing and secondary firing, and the raw material mixture obtained by the mixing step may be first primarily fired and then pulverized again with a ball mill or the like, followed by secondary firing.
The temperature for the primary firing is usually 1000 ° C. or higher, preferably 1050 ° C. or higher, and usually 1550 ° C. or lower, preferably 1500 ° C. or lower.
The primary firing time is usually 0.5 hours or longer, preferably 2 hours or longer, and usually 15 hours or shorter, preferably 12 hours or shorter.
The conditions such as the temperature and time of the secondary firing are basically the same as the conditions described in the above (Baking conditions) column.
The flux may be mixed before the primary firing or may be mixed before the secondary firing.
Also, the firing conditions such as the atmosphere may be changed between the primary firing and the secondary firing.

1-2-2-3. β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu phosphor The light emitting device of the present invention is represented by β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu as a green phosphor. A phosphor can be used. The composition of the β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu phosphor is preferably represented by the following formula [15], and such a phosphor includes the red phosphor described above. It can be manufactured in the same manner.

J _a1 i _b1 Al _b2 O _c1 N _c2 … [15]
(In the above formula [15], J contains at least Eu, and may further contain Ce and / or Mn.
a1, b1, b2, c1, and c2 are respectively
a1 + b1 + b2 + c1 + c2 = 1,
0.00001 ≦ a1 ≦ 0.1,
0.28 ≦ b1 ≦ 0.46,
0.001 ≦ b2 ≦ 0.3,
0.001 ≦ c1 ≦ 0.3,
0.4 ≦ c2 ≦ 0.6
Represents a number that satisfies )

1-2-2-4. (Ca, Sr, Ba) Si ₂ N ₂ O ₂ : Eu phosphor In the light-emitting device of the present invention, a phosphor represented by (Ca, Sr, Ba) Si ₂ N ₂ O ₂ : Eu as a green phosphor. Can be used. The composition of the (Ca, Sr, Ba) Si ₂ N ₂ O ₂ : Eu phosphor is preferably represented by the following formula [16], and such a phosphor is the same as the red phosphor described above. Can be manufactured.

_{(E 1-s J s)} Si 2 N 2 O 2 ... [16]
(In the above formula [16], E represents at least one alkaline earth metal element selected from the group consisting of Ca, Sr, and Ba,
J contains at least Eu, and may further contain Mn and / or Ce.
s represents a number satisfying 0.001 ≦ s ≦ 0.3. )

1-2-3. Blue phosphor In the light emitting device of the present invention, a blue phosphor having a fluorescence peak in a wavelength range of 420 nm to 470 nm is used. As this blue phosphor (hereinafter sometimes referred to as “blue phosphor of the present invention”), (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu and (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) It is preferable to use one or more selected from the group consisting of ₆ (Cl, F) ₂ : Eu.
Hereinafter, each phosphor will be described.

1-2-3-1. (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu phosphor The light emitting device of the present invention includes a barium aluminate-based blue fluorescence represented by (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu as a blue phosphor. (Hereinafter sometimes referred to as “the barium aluminate-based blue phosphor of the present invention”) can be used. Among them, it is preferable to use a phosphor whose composition is represented by the following formula [21], and more preferably a phosphor having the characteristics described below. This phosphor can be produced in the same manner as the barium aluminate green phosphor of the present invention as a preferred example of the green phosphor of the present invention described above, and the preferred elements and preferred compositions thereof are also the same.

_{(1-z) Ba (1} -efg) Sr e Ca f Eu g Mg (1-h-t) Zn h Mn t Al j O k
_{· (Z) Ba (0.75-} e'-f'-g ') Sr e' Ca f 'Eu g' Al 11 O 17.25 · D m
... [21]
(However, D represents at least one alkali metal element,
z, e, f, g, h, t, j, k, m, e ', f', g 'are respectively
0 ≦ z ≦ 1,
0 ≦ e <1,
0 ≦ f <1,
0.1 <g <1,
0 ≦ h <1,
0 ≦ t ≦ 0.5,
9 ≦ j ≦ 11,
16 ≦ k ≦ 18,
0 ≦ m ≦ 0.02,
0 ≦ e ′ <1,
0 ≦ f ′ <1,
0.1 <g ′ <1
Represents a number that satisfies )

  In the formula [21], t is usually 0.5 or less, preferably 0.1 or less, more preferably 0.01 or less, and still more preferably 0.

1-2-3-2. (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu phosphor [composition]
The light emitting device of the present invention includes an alkaline earth metal halophosphate blue phosphor represented by (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu as a blue phosphor ( Hereinafter, it may be referred to as “alkaline earth metal halophosphate blue phosphor of the present invention”). Although there is no restriction | limiting in particular as this alkaline-earth metal halophosphate blue fluorescent substance of this invention, It is preferable to use the fluorescent substance whose composition is represented by following formula [22] especially, and has the below-mentioned characteristic. More preferably, it is a body. The phosphor represented by the following formula [22] and having the characteristics described below can be manufactured by a manufacturing method described below.

As a specific example of the phosphor represented by the following formula [22], a part of the Sr site of the phosphor having a host crystal composition of Sr ₁₀ (PO ₄ ) ₆ Cl ₂ is substituted with a specific divalent metal element and Examples thereof include a structure in which substitution is performed with Eu and / or a part of the Cl site is replaced with another halogen element.
(Sr _10-x1-y1-z1 Q _x1 Eu _y1 Mn _z1 ) (PO ₄ ) ₆ (Cl _1-r X _r ) ₂ ... [22]
(In the above equation [22],
Q represents at least one element selected from the group consisting of Ba, Ca, Mg, and Zn,
X represents at least one element selected from the group consisting of F, Br, and I;
x1, y1, z1, and r are each
0 ≦ x1 <10,
0.05 ≦ y1 ≦ 2,
0 ≦ z1 ≦ 3,
0 ≦ r ≦ 1,
x1 + y1 + z1 ≦ 10,
Represents a number that satisfies )

  In the formula [22], Q represents one or more elements selected from the group consisting of Ba, Ca, Mg, and Zn. As said Q, any one of these elements may be contained independently and 2 or more types may be used together in arbitrary combinations and ratios. Among these, Ca is preferable.

  In the formula [22], x1 is a numerical value representing the amount of substitution of Q with respect to the Sr site. The numerical value is usually 0 or more, usually 10 or less, preferably 5 or less, more preferably 2 or less. When it is desired to obtain a phosphor having a wide emission spectrum half-width and high luminance, such as when used for illumination, x1 is usually 0.1 or more, preferably 0.5 or more, and usually 10 or less.

  In the formula [22], y1 is a numerical value representing the amount of Eu substitution for the Sr site. The lower limit of the numerical value is usually 0.05 or more, preferably 0.1 or more, more preferably 0.3 or more, particularly preferably 0.4 or more, and particularly preferably 0.5 or more. Here, if the substitution amount of Eu is small, there is a possibility that sufficient light emission intensity cannot be obtained. On the other hand, if the amount of Eu substitution is large, the emission intensity increases, but the temperature characteristics may decrease. Therefore, the upper limit of the Eu substitution amount is usually 2 or less, preferably 1.5 or less, more preferably 1.2 or less. Thus, by adjusting the Eu substitution amount, it is possible to obtain high temperature characteristics while keeping the emission intensity sufficiently high. Further, when the phosphor production method of the present invention described later is used, a high emission intensity can be obtained even if the substitution amount of Eu is small, so that a phosphor having excellent emission intensity and temperature characteristics can be obtained. It is preferable because it is possible.

  In the formula [22], z1 is a numerical value representing the amount of substitution of Mn with respect to the Sr site. The numerical value is usually 0 or more and usually 3 or less. In particular, when obtaining a phosphor emitting blue light, it is more preferable that Z1 = 0.

  The relationship between x1, y1, and z1 is preferably x1 + y1 + z1 ≦ 10, but more preferably x + y + z <10. This means that it is preferable that Sr is contained in the compound represented by the formula [22].

  In the formula [22], X represents one or more elements selected from the group consisting of F, Br, and I. As said X, any 1 type may be contained independently among these elements, and 2 or more types may be used together by arbitrary combinations and ratios.

  In the above formula [22], r is a numerical value representing the amount of substitution of X with respect to the Cl site. The numerical value is usually 0 or more and usually 1 or less, preferably 0.1 or less. If it exceeds this range, the emission peak wavelength may shift. In particular, when it is desired to obtain a blue-emitting phosphor, r = 0 is preferable.

As described above, in the formula [22], the Sr site can be substituted with a divalent metal element such as Ba, Ca, Mg, Zn, Mn, etc., and the Cl site can be substituted with F, Br, I. Etc. can be substituted. Since the alkaline earth metal is often located at the Sr site, the site can also be called an alkaline earth metal site.
Furthermore, as long as the amount is small, elements other than the elements described above may be substituted. For example, metallic elements having different valences such as Na and La may be substituted at the Sr site.
Therefore, the alkaline earth metal halophosphate blue phosphor of the present invention can have many kinds of chemical compositions.

Specific examples of preferred compositions of the alkaline earth metal halophosphate blue phosphor of the present invention include, for example, (Sr _9.2 Eu _0.8 ) (PO ₄ ) ₆ Cl ₂ , (Sr ₉ Eu) (PO ₄ ) ₆ Cl _{2 and the} like, but the composition of the alkaline earth metal halophosphate blue phosphor of the present invention is not limited thereto.

Further, the alkaline earth metal halophosphate blue phosphor of the present invention is not limited to the elements described in the above formula [22], that is, Sr, Q, Eu, Mn, PO ₄ , Cl, and X. An element selected from the group consisting of a valent element, a divalent element, a trivalent element, a −1 valent element, and a −3 valent element (hereinafter referred to as “trace element” as appropriate) may be contained. .

  Among these, as trace elements, alkali metal elements, alkaline earth metal elements, zinc (Zn), yttrium (Y), aluminum (Al), scandium (Sc), phosphorus (P), nitrogen (N), rare earth elements, And at least one element selected from the group consisting of halogen elements.

  The total content of the trace elements is usually 1 ppm or more, preferably 3 ppm or more, more preferably 5 ppm or more, and usually 100 ppm or less, preferably 50 ppm or less, more preferably 30 ppm or less. When the specific composition phosphor contains plural kinds of trace elements, the total amount thereof satisfies the above range.

[Characteristic]
<Excitation wavelength>
If the phosphor of the present invention can be excited by light in the near-ultraviolet region (wavelength range: 300 nm or more and 420 nm or less), it can be suitably used for a light emitting device using a semiconductor light emitting element or the like as a first light emitter. .

Furthermore, in the phosphor of the present invention, the intensity of the emission peak at an excitation wavelength of 400 nm in the excitation spectrum is I _ex (400) and the intensity of the emission peak at a wavelength of 350 nm is I _ex (350) at room temperature (25 ° C.). Then, it is preferable that the value of I _ex (400) / I _ex (350) satisfies the following formula [23].
0.76 ≦ I (400) / I (350) ... [23]

The value on the left side of the above formula [23] is 0.76, more preferably 0.8, more preferably 0.85, particularly preferably 0.9, and the closer to 1, the better. . That is, the value of I _ex (400) / I _ex (350) is preferably 0.76 or more, more preferably 0.8 or more, more preferably 0.85 or more, particularly preferably 0.9 or more, The closer it is, the better.

The value of I _ex (400) / I _ex (350) is a value that characterizes the shape of the excitation spectrum, and the closer the value is to 1, the flatter the excitation band. Therefore, when the value of I _ex (400) / I _ex (350) falls below the above range, the chromaticity and luminance of the light emitting device change due to individual differences in the emission peak wavelength of the excitation light source as described later. It may be easy to do.
Moreover, it is preferable that the value of _Iex (400) / _Iex (350) is 1.5 or less normally. This is because the excitation band is preferably flat as described above.

  Semiconductor light emitting devices such as LEDs and semiconductor laser diodes (hereinafter abbreviated as “LD” where appropriate) used as an excitation light source have a light emission peak wavelength that varies depending on the usage environment such as temperature, humidity, and current flow. It is generally well known that the emission peak wavelength tends to be unstable.

  In particular, the semiconductor light-emitting element has high temperature dependency, and the emission peak wavelength is likely to change due to the environmental temperature and, in particular, heat generated by energization. In addition, it is known that the wavelength changes depending on the lots at the time of manufacture or due to deterioration of the semiconductor light emitting element itself. However, at present, it is difficult to suppress the emission wavelength of the semiconductor light emitting element and to emit light of a certain wavelength from the semiconductor light emitting element.

Therefore, it is generally preferable that the phosphor has a flat excitation spectrum within a predetermined range. At this time, it is preferable that the flat excitation band in the excitation spectrum is wide. Since the alkaline earth metal halophosphate blue phosphor of the present invention absorbs excitation light in the near-ultraviolet wavelength region, if the excitation spectrum is flat in the excitation band from a wavelength of 350 nm to 400 nm, it can be said that the excitation band is wide. . Therefore, the alkaline earth metal halophosphate blue phosphor of the present invention is preferably as the value of I _ex (400) / I _ex (350) is closer to 1 as described above. This is because a light-emitting device that exhibits stable light emission can be manufactured.

(Method of bringing the value of I _ex (400) / I _ex (350) close to 1)
In order to bring the value of I _ex (400) / I _ex (350) close to 1, for example, the Eu amount may be set to a specific range. Increasing the amount of Eu is usually _the value of _{I ex (400) / I ex} (350) increases.
For example, in order for the value of I _ex (400) / I _ex (350) to be 0.76 or more, y in the formula [22] may be set to 0.3 or more.
Moreover, when the manufacturing method (multistage baking) of this invention mentioned later is performed, the value of _Iex (400) / _Iex (350) tends to increase.

The excitation spectrum can be measured using a fluorescence spectrophotometer F-4500 type (manufactured by Hitachi, Ltd.) at room temperature, for example, 25 ° C. The measurement is performed by monitoring the blue emission peak at 447 nm and measuring the excitation spectrum in the wavelength range of 250 nm to 530 nm. From the obtained excitation spectrum, the excitation peak wavelength, the value of I _ex (400) / I _ex (350), and the like can be calculated.

<Emission spectrum>
When the alkaline earth metal halophosphate blue phosphor of the present invention is irradiated with light having a wavelength in the near ultraviolet region (specifically, 400 nm), the emission peak wavelength λ _p (nm) is usually 430 nm or more, preferably Is 435 nm or more, more preferably 440 nm or more, and usually 470 nm or less, preferably 465 nm or less, more preferably 460 nm or less.

The alkaline earth metal halophosphate blue phosphor of the present invention has a light emission intensity of a wavelength component of 450 nm in the emission spectrum of the phosphor at room temperature (25 ° C.), ie, _Iemi (450), and a wavelength component of a wavelength of 430 nm. If the emission intensity of I is _Iemi (430), the value of _Iemi (450) / _Iemi (430) preferably satisfies the following formula [24].
2.3 ≤ _Iemi (450) / _Iemi (430) ... [24]
The value on the left side of the above formula [24] is 2.3, more preferably 3, and more preferably 3.5. That is, the value of _Iemi (450) / _Iemi (430) is preferably 2.3 or more, more preferably 3 or more, and more preferably 3.5 or more.

Furthermore, at room temperature (25 ° C.), when the emission intensity of the wavelength component of the wavelength 470nm of the emission spectrum of the phosphor and _I emi _(470), the value of _{I emi (450) / I emi} (470) is the following It is preferable to satisfy Formula [25].
2.5 ≦ _Iemi (450) / _Iemi (470) ... [25]

The value on the left side of the above formula [25] is 2.5, more preferably 2.8, and more preferably 3. That is, the value of _Iemi (450) / _Iemi (470) is preferably 2.5 or more, more preferably 2.8 or more, and more preferably 3 or more.

_Iemi (450) / _Iemi (430) and _Iemi (450) / _Iemi (470) are values characterizing the shape of the emission spectrum, and the larger the value, the sharper the shape of the emission peak. Show.

<Half width of emission peak>
In addition, the alkaline earth metal halophosphate blue phosphor of the present invention has a full width at half maximum (hereinafter referred to as “FWHM” where appropriate) of 1 nm or more. The range is preferably 20 nm or more, and usually 75 nm or less, preferably 65 nm or less. If the full width at half maximum FWHM is too narrow, the light emission intensity may decrease, and if it is too wide, the efficiency may decrease.

The emission spectrum is measured at room temperature, for example, 25 ° C., with a 150 W xenon lamp as an excitation light source, and a fluorescence measurement device (manufactured by JASCO) having a multichannel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measurement device. Can be used.
More specifically, the light from the excitation light source is passed through a diffraction grating spectrometer having a focal length of 10 cm, and only the excitation light having a wavelength of 350 nm or more and 410 nm or less is irradiated to the phosphor through the optical fiber. The light generated from the phosphor by the irradiation of the excitation light is dispersed by a diffraction grating spectroscope having a focal length of 25 cm, the emission intensity of each wavelength is measured by a spectrum measuring device in a wavelength range of 300 nm to 800 nm, and a personal computer is used. An emission spectrum is obtained through signal processing such as sensitivity correction. At the time of measurement, the slit width of the light receiving side spectroscope is set to 1 nm for measurement.

<Phosphor form>
The form of the alkaline earth metal halophosphate blue phosphor of the present invention preferably has a larger particle size than the conventional one. According to the multi-stage firing in the manufacturing method described later, it is considered that the growth of particles can be promoted, and as a result, a phosphor having a large particle size is obtained. When the particle size is large, the external quantum efficiency tends to increase, which is desirable as a phosphor.
Hereinafter, the form of the phosphor of the present invention will be specifically described in detail.

(D ₅₀ / QD)
D ₅₀ and QD are both values related to the particle size.
In the present invention, D ₅₀ is a weight median diameter D ₅₀ (hereinafter referred to as “median diameter D ₅₀ ”) and is defined as follows.
The median diameter D _50, is a value obtained by the weight particle size distribution curve. The weight-based particle size distribution curve is obtained by measuring the particle size distribution by a laser diffraction / scattering method. Specifically, the phosphor is dispersed in an aqueous solution containing a dispersant, and measured by a laser diffraction particle size distribution measuring device (Horiba LA-300) in a particle size range of 0.1 μm to 600 μm. Value.
The median diameter D ₅₀ means a particle size value when the integrated value is 50% in this weight-based particle size distribution curve. Similarly, in the weight-based particle size distribution curve, the particle size values when the integrated values are 25% and 75% are denoted as D ₂₅ and D ₇₅ , respectively.

QD is a standard deviation (4-minute deviation). Specifically, it is defined as standard deviation (4-minute deviation) QD = (D ₇₅ −D ₂₅ ) / (D ₇₅ + D ₂₅ ). A small QD means a narrow particle size distribution.

The alkaline earth metal halophosphate blue phosphor of the present invention usually has a substantially normal particle size distribution, and its median diameter D ₅₀ is preferably 5 μm or more, more preferably 10 μm or more, and preferably It is 20 μm or less, more preferably 15 μm or less.

And 5μm smaller than the median diameter D _50, there is a tendency that absorption of the blue excitation light is low, high luminance phosphor may become difficult to obtain. On the other hand, if the median diameter D ₅₀ is larger than 20 μm, it tends to be difficult to use in a nozzle device or the like practically.

Particle size distribution QD value of alkaline earth metal halophosphate blue phosphor of the present invention, when using the phosphor of the single median diameter D _50, and is generally 0.26 or less, preferably 0.24 or less, Especially preferably, it is 0.23 or less.
In order to increase luminous efficiency, the absorption efficiency, when used in combination a plurality of different phosphors median diameter D _50, QD of the phosphor mixture may become greater than 0.26.

(Particle shape / average circularity)
The alkaline earth metal halophosphate blue phosphor of the present invention is preferably closer to a perfect sphere.
The average circularity can be used as an index that quantitatively represents the spherical nature of the phosphor particles. Here, the average circularity is a circularity representing the degree of approximation with a perfect circle of each particle size in the projected image of the particle (circularity = perimeter of the perfect circle equal to the projected area of the particle / perimeter of the projected particle) Length). If it is a perfect sphere, the average circularity is 1. The average circularity is measured using a flow particle image analyzer ("FPIA-2000" manufactured by Sysmex) after dispersing the sample in the same manner as in the case of the weight median diameter D ₅₀ described above.

  In the manufacture of the phosphor, it is preferable that extremely large or small particles are removed, but some contamination is practically unavoidable. In the alkaline earth metal halophosphate blue phosphor of the present invention, it is preferable to compare the circularity of particles having a particle size of 5 μm or more and 30 μm or less, instead of comparing the circularity for the entire range of particle sizes. If the average circularity of the phosphor is less than 0.94, the luminous efficiency of a light emitting device using the phosphor may not be sufficient. Therefore, the average circularity of the alkaline earth metal halophosphate blue phosphor of the present invention is preferably 0.94 or more, more preferably 0.95 or more, and the closer to 1, the more preferable.

  In addition, if the shape of the phosphor is an irregular shape such as a needle shape, a plate shape, or a ball shape formed by fusion of particles, it tends to aggregate in the dispersion medium and a uniform phosphor film tends to be difficult to obtain. . In addition, when light whose wavelength has been converted by the phosphor is emitted from the phosphor, the emission distribution may be biased if the shape has anisotropy.

1-2-4. Post-processing In each phosphor manufacturing method described above, processing other than those described above may be performed at any time.
For example, when the particle size of the obtained phosphor is not a desired particle size, the phosphor after the heat treatment may be crushed. Although there is no restriction | limiting in the method of a pulverization process, For example, the dry pulverizer, the wet pulverizer etc. which were illustrated by the term of description of a raw material mixing method can be used.

  Further, for example, the cleaning treatment may be performed on the phosphor after the heat treatment. There is no restriction | limiting in the washing | cleaning liquid used for a washing process, For example, you may wash | clean with water, but you may wash | clean with warm water or hot water. In particular, cleaning with an acid is preferable because an impurity phase other than the phosphor base crystal such as a flux attached to the phosphor surface can be removed and the light emission characteristics can be improved.

  The degree of washing can be represented by the electrical conductivity of the supernatant obtained by dispersing the washed phosphor in 10 times the weight ratio of water and allowing it to stand for 1 hour. The electrical conductivity is preferably as low as possible from the viewpoint of light emission characteristics, but in consideration of productivity, the washing treatment is usually repeated until it is 10 mS / m or less, preferably 5 mS / m or less, more preferably 4 mS / m or less. It is preferable.

  As a method for measuring electrical conductivity, phosphor particles having a specific gravity heavier than water are obtained by stirring and dispersing in water 10 times the weight of the phosphor for a predetermined time, for example, 10 minutes, and then allowing to stand for 1 hour. The electrical conductivity of the supernatant liquid at this time may be measured using an electrical conductivity meter “EC METER CM-30G” manufactured by Toa Decay Co., Ltd. Although there is no restriction | limiting in particular as water used for a washing process and a measurement of electrical conductivity, Demineralized water or distilled water is preferable. Among them, those having particularly low electric conductivity are preferable, and those having a conductivity of usually 0.0064 mS / m or more, and usually 1 mS / m or less, preferably 0.5 mS / m or less are used. The electrical conductivity is usually measured at room temperature (about 25 ° C.).

  Furthermore, the degree of washing is preferably such that the supernatant obtained by dispersing the washed phosphor in water 10 times by weight and allowing it to stand for 1 hour is neutral (about pH 7-9). This is because if it is biased toward basicity or acidity, the liquid medium or the like may be adversely affected when mixed with the liquid medium or the like described later.

  Further, for example, surface treatment may be performed on the phosphor after the heat treatment. Examples of the surface treatment include a treatment in which fine particles such as silica, alumina, and calcium phosphate are attached to the surface of the phosphor as a thin layer. Thereby, the powder characteristics (aggregation state, dispersibility in solution, sedimentation behavior, etc.) of the phosphor can be improved.

Furthermore, for example, a drying process or a classification process may be performed.
In addition, post-treatment after heat treatment is generally known for known phosphors such as phosphors used in cathode ray tubes, plasma display panels, fluorescent lamps, fluorescent display tubes, X-ray intensifying screens, and the like. A technique can be used, and can be selected as appropriate according to the purpose and application.

1-2-5. Preferred combinations of phosphors 1-2-5-1. In the case of a white light emitting device When the light emitting device of the present invention is a white light emitting device, as the green phosphor of the second light emitter, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, Mn, β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu, (Ba, Sr) ₃ Si ₆ O ₁₂ N ₂ : Eu and (Ca, Sr, Ba) It is preferable to use one or more selected from the group consisting of Si ₂ N ₂ O ₂ : Eu.
The blue phosphor is selected from the group consisting of (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu and (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu. It is preferable to use 1 type, or 2 or more types.

A particularly preferred combination is that one or more of the phosphors represented by the formula [4A] or [4] are used as the red phosphor, and (Ba, Sr, Ca, Mg) ₂ SiO as the green phosphor. ₄ : Eu, β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu, and (Ca, Sr, Ba) Si ₂ N ₂ O ₂ : One or more selected from the group consisting of Eu and In addition, one or more of (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu as a blue phosphor is combined.

  In addition, the usage ratio of the phosphors of each color is 5 to 30 parts by weight of the red phosphor and 2 parts by weight of the green phosphor in a total of 100 parts by weight of the red phosphor, the green phosphor and the blue phosphor. It is preferable to use the blue phosphor in an amount of 30 parts by weight to 95 parts by weight. If there is more red phosphor than this range, the color temperature tends to be low, and if it is less, the color temperature tends to be high. Further, when the amount of the green phosphor is large, it tends to be difficult to make it white, and when it is small, the color rendering property tends to be lowered. Further, when the amount of blue phosphor is large, the color temperature tends to be high, and when it is small, the color temperature tends to be low.

  In the white light-emitting device, the green phosphor is based on an oxide or oxynitride containing Si containing Eu as an activation element, and the half-value width of the emission peak is not less than 45 nm and not more than 70 nm. The phosphor is preferably a phosphor, and the blue phosphor is preferably a phosphor having an emission peak half width of 45 nm to 70 nm. This is due to the good balance between color rendering and luminous efficiency when combined with a red phosphor having a relatively wide half-value width of the emission spectrum.

1-2-4-2. In the case of a light bulb color light emitting device When the light emitting device of the present invention is a light bulb color light emitting device, as the green phosphor of the second light emitter, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, Mn, β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu, (Ba, Sr) ₃ Si ₆ O ₁₂ N ₂ : Eu and (Ca, Sr, Ba) It is preferable to use one or more selected from the group consisting of Si ₂ N ₂ O ₂ : Eu.
The blue phosphor is selected from the group consisting of (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu and (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu. It is preferable to use 1 type, or 2 or more types.

A particularly preferred combination is that one or more of the phosphors represented by the formula [4A] or [4] are used as the red phosphor, and (Ba, Sr, Ca, Mg) ₂ SiO as the green phosphor. ₄ : Eu, β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu, and (Ca, Sr, Ba) Si ₂ N ₂ O ₂ : One or more selected from the group consisting of Eu and In addition, one or more of (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu as a blue phosphor is combined.

  In addition, the usage ratio of the color phosphor is 10 to 90 parts by weight of the red phosphor and 1.5 to 1.5 parts of the green phosphor in a total of 100 parts by weight of the red phosphor, the green phosphor and the blue phosphor. It is preferable to use the phosphor in an amount of not less than 35 parts by weight and not more than 35 parts by weight and the blue phosphor in an amount of not less than 40 parts by weight and not more than 80 parts by weight. If there is more red phosphor than this range, the color temperature tends to be low, and if it is less, the color temperature tends to be high. Further, when the amount of the green phosphor is large, it tends to be difficult to make it white, and when it is small, the color rendering property tends to be lowered. Further, when the amount of blue phosphor is large, the color temperature tends to be high, and when it is small, the color temperature tends to be low.

  In the light bulb color light emitting device, the green phosphor is based on an oxide or oxynitride containing Si containing Eu as an activation element, and the half width of the emission peak is 55 nm or more and 100 nm or less. The phosphor is preferably a phosphor, and the blue phosphor is preferably a phosphor having an emission peak half width of 55 nm to 100 nm. This is because the color rendering properties tend to be improved when a phosphor having a wide half-value width of the emission peak is used.

1-3. Sealing Material In the light emitting device of the present invention, each phosphor that is the second light emitter is usually used by being dispersed in a liquid medium that is a sealing material.
The liquid medium is not particularly limited as long as the performance of the phosphor dispersed therein is not impaired within the intended range. For example, any inorganic material and / or organic material may be used as long as it exhibits liquid properties under the desired use conditions, suitably disperses the phosphor of the present invention, and does not cause an undesirable reaction. it can.

  Examples of the inorganic material include a solution obtained by hydrolytic polymerization of a solution containing a metal alkoxide, a ceramic precursor polymer or a metal alkoxide by a sol-gel method, or an inorganic material (for example, having a siloxane bond). Inorganic material).

  Examples of organic materials include thermoplastic resins, thermosetting resins, and photocurable resins. Specific examples include methacrylic resins such as methyl polymethacrylate; styrene resins such as polystyrene and styrene-acrylonitrile copolymers; polycarbonate resins; polyester resins; phenoxy resins; butyral resins; polyvinyl alcohols; Cellulose-based resins such as cellulose acetate butyrate; epoxy resins; phenol resins; silicone resins.

  Among these, in the case of a light-emitting device having a high output such as illumination, it is preferable to use a silicon-containing compound for the purpose of heat resistance and light resistance.

  The silicon-containing compound refers to a compound having a silicon atom in the molecule, for example, an organic material (silicone material) such as polyorganosiloxane, an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, and borosilicate. And glass materials such as phosphosilicate and alkali silicate. Among these, silicone materials are preferable from the viewpoint of ease of handling.

The silicone material generally refers to an organic polymer having a siloxane bond as a main chain, and examples thereof include a compound represented by the following formula (i) and / or a mixture thereof.
(R ¹ R ² R ³ SiO _1/2 ) _M (R ⁴ R ⁵ SiO _2/2 ) _D
(R ⁶ SiO _3/2 ) _T (SiO _4/2 ) _Q (i)

In the above formula (i), from R ¹ R ⁶ may be the same or different, organic functional group, hydroxyl group, is selected from the group consisting of a hydrogen atom.
In the above formula (i), M, D, T, and Q are numbers that are 0 or more and less than 1, respectively, and that satisfy M + D + T + Q = 1.

  When used for sealing a semiconductor light emitting device, the silicone material can be used after being sealed with a liquid silicone material and then cured by heat or light.

  When silicone materials are classified according to the curing mechanism, silicone materials such as an addition polymerization curing type, a condensation polymerization curing type, an ultraviolet curing type, and a peroxide vulcanization type can be generally cited. Among these, addition polymerization curing type (addition type silicone material), condensation curing type (condensation type silicone material), and ultraviolet curing type are preferable. Hereinafter, the addition type silicone material and the condensation type silicone material will be described.

  The addition-type silicone material refers to a material in which polyorganosiloxane chains are crosslinked by organic addition bonds. Typical examples include compounds having a Si—C—C—Si bond at the crosslinking point obtained by reacting vinylsilane and hydrosilane in the presence of an addition catalyst such as a Pt catalyst. As these, commercially available products can be used. Specific examples of addition polymerization curing type trade names include “LPS-1400”, “LPS-2410”, and “LPS-3400” manufactured by Shin-Etsu Chemical Co., Ltd.

On the other hand, examples of the condensation type silicone material include a compound having a Si—O—Si bond obtained by hydrolysis and polycondensation of an alkylalkoxysilane at a crosslinking point.
Specific examples include polycondensates obtained by hydrolysis and polycondensation of compounds represented by the following general formula (ii) and / or (iii) and / or oligomers thereof.

M ′ ^{m ′ +} X ′ _{n ′} Y ′ _{m′−n ′} (ii)
(In formula (ii), M ′ represents at least one element selected from silicon, aluminum, zirconium and titanium, X ′ represents a hydrolyzable group, and Y ′ represents a monovalent organic compound. M ′ represents one or more integers representing the valence of M ′, and n ′ represents one or more integers representing the number of X ′ groups, provided that m ′ ≧ n ′. )

^{(M 's' + X '} t' Y ') u' Y '' ... (iii)
(In the formula (iii), M ′ represents at least one element selected from silicon, aluminum, zirconium, and titanium, X ′ represents a hydrolyzable group, and Y ′ represents a monovalent organic compound. Y ″ represents a u′-valent organic group, s ′ represents an integer of 1 or more representing the valence of M ′, t ′ is an integer of 1 or more and s′−1 or less. And u ′ represents an integer of 2 or more.)

  Further, the condensation type silicone material may contain a curing catalyst. As this curing catalyst, for example, a metal chelate compound or the like can be suitably used. The metal chelate compound preferably contains one or more of Ti, Ta, and Zr, and more preferably contains Zr. In addition, only 1 type may be used for a curing catalyst and it may use 2 or more types together by arbitrary combinations and a ratio.

  Examples of such condensation-type silicone materials include Japanese Patent Application Nos. 2006-47274 to 47277 (for example, Japanese Patent Application Laid-Open Nos. 2007-119297 to 112975 and Japanese Patent Application No. 2007-19459) and Japanese Patent Application No. 2006-176468. The member for semiconductor light-emitting devices described in the specification is suitable.

Of the condensed silicone materials, particularly preferred materials will be described below.
Silicone-based materials generally have a problem of poor adhesion to semiconductor light-emitting elements, substrates on which the elements are arranged, packages, and the like, but as silicone-based materials having high adhesion, the following features [1] to A condensation type silicone material having one or more of [3] is preferred.

[1] The silicon content is 20% by weight or more.
[2] The solid Si-nuclear magnetic resonance (NMR) spectrum measured by the method described in detail later has at least one peak derived from Si in the following (a) and / or (b).
(A) A peak whose peak top position is in a region where the chemical shift is −40 ppm or more and 0 ppm or less with respect to tetramethoxysilane, and the half width of the peak is 0.3 ppm or more and 3.0 ppm or less.
(B) A peak whose peak top position is in a region where the chemical shift is −80 ppm or more and less than −40 ppm with respect to tetramethoxysilane, and the half width of the peak is 0.3 ppm or more and 5.0 ppm or less.
[3] The silanol content is 0.1% by weight or more and 10% by weight or less.

In the present invention, among the above features [1] to [3], a silicone material having the feature [1] is preferable, a silicone material having the above features [1] and [2] is more preferable, Particularly preferred are silicone materials having all the features [1] to [3].
Hereinafter, the above features [1] to [3] will be described.

<Characteristic [1] (silicon content)>
The basic skeleton of conventional silicone materials is an organic resin such as an epoxy resin having carbon-carbon and carbon-oxygen bonds as the basic skeleton, whereas the basic skeleton of silicone materials suitable for the present invention is glass (silica). It is the same inorganic siloxane bond as acid glass). As apparent from the chemical bond comparison table shown in Table 2 below, this siloxane bond has the following characteristics excellent as a silicone material.

(I) Since the binding energy is large and thermal decomposition and photolysis are difficult, light resistance is good.
(II) It is slightly polarized electrically.
(III) The degree of freedom of the chain structure is large, a structure with high flexibility is possible, and the chain structure can freely rotate around the center of the siloxane chain.
(IV) The degree of oxidation is large and no further oxidation occurs.
(V) Rich in electrical insulation.

  Because of these characteristics, silicone-based silicone materials that are formed with a skeleton in which siloxane bonds are three-dimensionally bonded with a high degree of crosslinking are close to inorganic materials such as glass or rock, and have a high heat resistance and light resistance. Can be understood. In particular, a silicone-based material having a methyl group as a substituent has no absorption in the ultraviolet region, so that photolysis hardly occurs and has excellent light resistance.

The silicon content of the silicone material suitable for the present invention is usually 20% by weight or more, preferably 25% by weight or more, and more preferably 30% by weight or more. On the other hand,
Because the silicon content of the glass composed solely of SiO2 is 47% by weight, it is usually 4
The range is 7% by weight or less.

  Note that the silicon content of the silicone-based material is calculated based on the results obtained by performing inductively coupled plasma spectroscopy (hereinafter abbreviated as “ICP” as appropriate), for example, using the following method. be able to.

{Measurement of silicon content}
Silicone material was baked in a platinum crucible in the air at 450 ° C. for 1 hour, then at 750 ° C. for 1 hour, and at 950 ° C. for 1.5 hours to remove the carbon component, and then a small amount of residue was obtained. Add more than 10 times the amount of sodium carbonate and heat with a burner to melt, cool this, add demineralized water, and adjust the pH to neutral with hydrochloric acid to a few ppm as silicon. ICP analysis is performed.

<Feature [2] (Solid Si-NMR spectrum)>
When a solid Si-NMR spectrum of a silicone-based material suitable for the present invention is measured, at least one peak in the peak region of (a) and / or (b) derived from a silicon atom to which a carbon atom of an organic group is directly bonded, Preferably, a plurality of peaks are observed.

When arranged for each chemical shift, in the silicone-based material suitable for the present invention, the half width of the peak described in (a) is generally less than the peak described in (b) described later because molecular motion is less restricted. It is smaller than the case, usually in the range of 3.0 ppm or less, preferably 2.0 ppm or less, and usually 0.3 ppm or more.
On the other hand, the full width at half maximum of the peak described in (b) is usually 5.0 ppm or less, preferably 4.0 ppm or less, and usually 0.3 ppm or more, preferably 0.4 ppm or more.

  If the half-value width of the peak observed in the chemical shift region is too large, the molecular motion is constrained and the strain becomes large, cracks are likely to occur, and the member may be inferior in heat resistance and weather resistance. For example, in the case where a large amount of tetrafunctional silane is used, or in the state where rapid drying is performed in the drying process and a large internal stress is stored, the full width at half maximum is larger than the above range.

  In addition, if the half width of the peak is too small, Si atoms in the environment will not be involved in siloxane crosslinking, and heat resistance is higher than that of substances formed mainly from siloxane bonds, such as cases where trifunctional silane remains in an uncrosslinked state. -It may be a member inferior in weather resistance.

  However, in a silicone material containing a small amount of Si component in a large amount of organic component, good heat resistance / light resistance and coating performance can be obtained even if the peak of the above-mentioned half-value range is observed at -80 ppm or more. There may not be.

  The chemical shift value of the silicone material suitable for the present invention can be calculated based on the results of solid Si-NMR measurement using the following method, for example. In addition, analysis of measurement data (half-width or silanol amount analysis) is performed by a method of dividing and extracting each peak by, for example, waveform separation analysis using a Gaussian function or a Lorentz function.

{Solid Si-NMR spectrum measurement and silanol content calculation}
When performing a solid Si-NMR spectrum about a silicone type material, a solid Si-NMR spectrum measurement and waveform separation analysis are performed on condition of the following. Further, from the obtained waveform data, the half width of each peak is determined for the silicone material. Also, from the ratio of the peak area derived from silanol to the total peak area, the ratio (%) of silicon atoms that are silanols in all silicon atoms is obtained, and the silanol content is determined by comparing with the silicon content analyzed separately. Ask.

{Device conditions}
Apparatus: Chemmagnetics Infinity CMX-400 Nuclear Magnetic Resonance
Spectrometer 29Si resonance frequency: 79.436 MHz
Probe: 7.5 mmφ CP / MAS probe Measurement temperature: room temperature Sample rotation speed: 4 kHz
Measurement method: Single pulse method
1H decoupling frequency: 50 kHz
29Si flip angle: 90 ° 29Si90 ° pulse width: 5.0μs
Repeat time: 600s
Integration count: 128 Observation width: 30 kHz
Broadening factor: 20Hz
Reference sample: Tetramethoxysilane

  For silicone-based materials, 512 points are taken as measurement data, zero-filled to 8192 points, and Fourier transformed.

{Waveform separation analysis method}
For each peak of the spectrum after Fourier transform, optimization calculation is performed by a non-linear least square method with the center position, height, and half width of the peak shape created by Lorentz waveform and Gaussian waveform or a mixture of both as variable parameters.
In addition, identification of a peak is AIChE Journal, 44 (5), p. Refer to 1141, 1998, etc.

<Feature [3] (silanol content)>
The silicone material suitable for the present invention has a silanol content of usually 0.1% by weight or more, preferably 0.3% by weight or more, and usually 10% by weight or less, preferably 8% by weight or less, more preferably The range is 5% by weight or less. By reducing the silanol content, the silanol-based material has excellent performance with little change over time, excellent long-term performance stability, and low moisture absorption and moisture permeability. However, since a member containing no silanol is inferior in adhesion, there exists an optimum range for the silanol content as described above.

  In addition, the silanol content rate of a silicone type material uses the method demonstrated in the item of {the solid-state Si-NMR spectrum measurement and calculation of silanol content rate} of <characteristic [2] (solid Si-NMR spectrum)> above, for example. The solid Si-NMR spectrum measurement was performed, and the ratio (%) of silicon atoms that are silanols in the total silicon atoms was determined from the ratio of the peak area derived from silanol to the total peak area, and compared with the silicon content analyzed separately. This can be calculated.

  In addition, since the silicone-based material suitable for the present invention contains an appropriate amount of silanol, the silanol usually bonds with hydrogen at the polar portion present on the device surface, thereby exhibiting adhesion. Examples of the polar part include a hydroxyl group and a metalloxane-bonded oxygen.

In addition, the silicone material suitable for the present invention is usually heated in the presence of an appropriate catalyst to form a covalent bond by dehydration condensation with the hydroxyl group on the device surface, thereby exhibiting stronger adhesion. can do.

  On the other hand, if there is too much silanol, the inside of the system will thicken and it will be difficult to apply, or it will become more active and solidify before the light-boiling components volatilize by heating, leading to increased foaming and internal stress. It may occur and induce cracks.

  The amount of the liquid medium used is arbitrary as long as the effects of the present invention are not significantly impaired. For example, it is usually 50% by weight or more with respect to the entire phosphor-containing composition obtained by dispersing the phosphor in the liquid medium, preferably Is 75% by weight or more, usually 99% by weight or less, preferably 95% by weight or less. When the amount of the liquid medium is large, no particular problem occurs. However, in order to obtain the desired chromaticity coordinates, color rendering index, luminous efficiency, etc. in the case of a light emitting device, the liquid is usually mixed at the above blending ratio. It is desirable to use a medium. On the other hand, if there is too little liquid medium, there is a possibility that it will be difficult to handle due to lack of fluidity.

  The liquid medium mainly has a role as a binder in the phosphor-containing composition. The liquid medium may be used alone or in combination of two or more in any combination and ratio. For example, when a silicon-containing compound is used for the purpose of heat resistance, light resistance, etc., other thermosetting resins such as an epoxy resin may be contained to the extent that the durability of the silicon-containing compound is not impaired. In this case, the content of the other thermosetting resin is usually 25% by weight or less, preferably 10% by weight or less based on the total amount of the liquid medium as the binder.

  In addition, the phosphor-containing composition may contain other components in addition to the phosphor and the liquid medium as long as the effects of the present invention are not significantly impaired. Moreover, only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and a ratio.

  For example, the phosphor-containing composition may contain a metal element that can be a metal oxide having a high refractive index in order to adjust the refractive index of the sealing member. Examples of metal elements that give a metal oxide having a high refractive index include Si, Al, Zr, Ti, Y, Nb, and B. These metal elements may be used alone or in combination of two or more in any combination and ratio.

  The presence form of such a metal element is not particularly limited as long as the transparency of the sealing member is not impaired. For example, a uniform glass layer may be formed as a metalloxane bond, and is present in a particulate form in the sealing member. You may do it. When present in the form of particles, the structure inside the particles may be amorphous or crystalline, but in order to give a high refractive index, a crystalline structure is preferred. Further, the particle diameter is usually not more than the emission wavelength of the first light emitter (semiconductor light emitting device), preferably not more than 100 nm, more preferably not more than 50 nm, particularly preferably in order not to impair the transparency of the sealing member. 30 nm or less. For example, by mixing particles of silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, yttrium oxide, niobium oxide, etc. with a silicone-based material, the metal element can be present in the sealing member in the form of particles. .

  The phosphor-containing composition may further contain known additives such as a diffusing agent, a filler, a viscosity modifier, and an ultraviolet absorber. In addition, these additives may use only 1 type and may use 2 or more types together by arbitrary combinations and ratios.

1-4. Configuration of other light emitting devices (others)
The other configurations of the light emitting device of the present invention are not particularly limited as long as the first light emitting body and the second light emitting body described above are provided. Usually, the first light emitting body described above is formed on an appropriate frame. And second
The luminous body is arranged. At this time, the second light emitter is excited by the light emission of the first light emitter (that is, the first and second phosphors are excited) to emit light, and the first light emitter emits light. And / or it arrange | positions so that light emission of a 2nd light-emitting body may be taken out outside. In this case, the first phosphor and the second phosphor are not necessarily mixed in the same layer. For example, the second phosphor is contained on the layer containing the first phosphor. For example, the phosphor may be contained in a separate layer for each color development of the phosphor, such as by stacking layers.

  In the light emitting device of the present invention, members other than the above-described excitation light source (first light emitter), phosphor (second light emitter), and frame may be used. Examples thereof include the aforementioned sealing materials. In addition to the purpose of dispersing the phosphor (second light emitter) in the light emitting device, the sealing material is provided between the excitation light source (first light emitter), the phosphor (second light emitter), and the frame. It can be used for the purpose of bonding.

2. Characteristics of Light-Emitting Device The light-emitting device of the present invention can obtain a desired luminescent color by changing the type of phosphor to be combined and its mixing ratio. Specifically, luminescent colors such as white, light bulb color, daylight color, day white color, and warm white color can be obtained. Among these, white or light bulb color is preferable.

[For white light emitting device]
The shape of the emission spectrum preferably has a shape as shown in FIG.

  Further, when the light emitted from the light emitting device is expressed in the XYZ color system (JIS Z8701), the value of the chromaticity coordinate x is usually 0.30 or more, preferably 0.32 or more, and usually 0.38 or less, preferably Is in the range of 0.35 or less, and the value of the chromaticity coordinate y is usually 0.30 or more, preferably 0.32 or more, and usually 0.40 or less, preferably 0.35 or less.

  The luminous efficiency when driven at a current of 20 mA is preferably as high as possible, and is usually 10 lm / W (Lumen / W) or higher, preferably 15 lm / W or higher.

The average color rendering index (Ra) of the luminescent color is usually 80 or more, preferably 85 or more, and usually 100 or less. Ra is an average of the color rendering index of eight colors (R1 to R8), and the higher the value, the better and better the color rendering properties.
The special color rendering index (R9) of the luminescent color is usually 27 or more, preferably 40 or more, and usually 100 or less. R9 means the color rendering property of red (R9).

[In case of light bulb color light emitting device]
The shape of the emission spectrum preferably has a shape as shown in FIG.

  Further, when the light emitted from the light emitting device is expressed in the XYZ color system (JIS Z8701), the value of the chromaticity coordinate x is usually 0.39 or more, preferably 0.42 or more, and usually 0.475 or less, preferably Is in the range of 0.46 or less, and the value of the chromaticity coordinate y is usually 0.375 or more, preferably 0.38 or more, and usually 0.425 or less, preferably 0.42 or less.

  Further, the higher the light emission efficiency when driven at a current of 20 mA, the higher is usually 10 lm / W or higher, preferably 15 lm / W or higher.

The average color rendering index (Ra) of the luminescent color is usually 80 or more, preferably 85 or more, and usually 100 or less. The higher the Ra, the better the color rendering and the more preferable.
The special color rendering index (R9) of the luminescent color is usually 27 or more, preferably 55 or more, and usually 100 or less.

  The emission spectrum of the light-emitting device is measured by energizing 20 mA with a color / illuminance measurement software and USB2000 series spectroscope (integral sphere specification) manufactured by Ocean Optics in a room maintained at a temperature of 25 ± 1 ° C. Can be done. Chromaticity values (x, y, z) can be calculated as chromaticity coordinates in the XYZ color system defined by JIS Z8701 from data in the wavelength region of 380 nm to 780 nm of the emission spectrum. In this case, the relational expression x + y + z = 1 holds. In the present specification, the XYZ color system may be referred to as an XY color system, and is usually expressed as (x, y).

  The luminous efficiency is obtained by obtaining the total luminous flux from the result of the emission spectrum measurement using the light emitting device as described above, and dividing the lumen (lm) value by the power consumption (W). The power consumption is obtained by measuring a voltage using a True RMS Multimeters Model 187 & 189 manufactured by Fluke in a state in which 20 mA is energized, and obtaining the product of the current value and the voltage value.

3. Embodiments of Light-Emitting Device Hereinafter, the light-emitting device of the present invention will be described in more detail with specific embodiments, but the present invention is not limited to the following embodiments, and the gist of the present invention Any modification can be made without departing from the scope of the invention.

FIG. 1 is a schematic perspective view showing a positional relationship between a first light emitter serving as an excitation light source and a second light emitter configured as a phosphor containing portion having a phosphor in an example of the light emitting device of the present invention. Shown in
In FIG. 1, reference numeral 1 denotes a phosphor-containing portion (second light emitter), reference numeral 2 denotes a surface-emitting GaN-based LD as an excitation light source (first light emitter), and reference numeral 3 denotes a substrate. In order to create a state in which they are in contact with each other, LD (2) and phosphor-containing portion (second light emitter) (1) are produced separately, and their surfaces are brought into contact with each other by an adhesive or other means. Alternatively, the phosphor-containing portion (second light emitter) may be formed (molded) on the light emitting surface of the LD (2). As a result, the LD (2) and the phosphor-containing portion (second light emitter) (1) can be brought into contact with each other.

  When such an apparatus configuration is employed, the light loss is such that light from the excitation light source (first light emitter) is reflected by the film surface of the phosphor-containing portion (second light emitter) and oozes out. Therefore, the light emission efficiency of the entire device can be improved.

  FIG. 2A is a typical example of a light emitting device of a form generally referred to as a shell type, and has a light emission having an excitation light source (first light emitter) and a phosphor-containing portion (second light emitter). It is typical sectional drawing which shows one Example of an apparatus. In the light emitting device (4), reference numeral 5 is a mount lead, reference numeral 6 is an inner lead, reference numeral 7 is an excitation light source (first light emitter), reference numeral 8 is a phosphor-containing resin portion, reference numeral 9 is a conductive wire, reference numeral Reference numeral 10 denotes a mold member.

  FIG. 2B is a typical example of a light-emitting device of a form called a surface-mount type, and has light emission having an excitation light source (first light emitter) and a phosphor-containing portion (second light emitter). It is typical sectional drawing which shows one Example of an apparatus. In the figure, reference numeral 22 is an excitation light source (first light emitter), reference numeral 23 is a phosphor-containing resin portion as a phosphor-containing portion (second light emitter), reference numeral 24 is a frame, reference numeral 25 is a conductive wire, Reference numerals 26 and 27 indicate electrodes.

4). Use of light-emitting device The use of the light-emitting device of the present invention is not particularly limited, and can be used in various fields in which ordinary light-emitting devices are used. It is particularly preferably used as a light source for the apparatus.

[Lighting device]
When the light-emitting device of the present invention is applied to a lighting device, the above-described light-emitting device may be appropriately incorporated into a known lighting device. For example, a surface emitting illumination device (11) incorporating the above-described light emitting device (4) as shown in FIG. 3 can be mentioned.

  FIG. 3 is a cross-sectional view schematically showing an embodiment of a lighting device using the light emitting device of the present invention. As shown in FIG. 3, the surface-emitting illumination device has a number of light-emitting devices (13) (described above) on the bottom surface of a rectangular holding case (12) whose inner surface is light-opaque such as a white smooth surface. The light emitting device (4) corresponds to the lid portion of the holding case (12) by arranging a power source and a circuit (not shown) for driving the light emitting device (13) on the outside thereof. A diffuser plate (14) such as a milky white acrylic plate is fixed at a location for uniform light emission.

  Then, the surface emitting illumination device (11) is driven to apply light to the excitation light source (first light emitter) of the light emitting device (13) to emit light, and part of the light emission is converted into the phosphor. The phosphor in the phosphor-containing resin part as the containing part (second light emitter) absorbs and emits visible light, while having high color rendering due to color mixing with blue light or the like that is not absorbed by the phosphor. Luminescence is obtained, and this light is transmitted through the diffusion plate (14) and emitted upward in the drawing, so that illumination light with uniform brightness can be obtained within the surface of the diffusion plate (14) of the holding case (12). Become.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples without departing from the gist thereof.

[Measurement method of physical properties]
The physical properties of the phosphors obtained in the production examples described later, and the light emitting devices obtained in the examples and comparative examples can be measured and calculated by the following methods.

<Emission spectrum of phosphor>
The emission spectrum was measured at room temperature (25 ° C.) using a 150 W xenon lamp as an excitation light source and a fluorescence measuring apparatus (manufactured by JASCO Corporation) equipped with a multi-channel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measuring apparatus. did.
More specifically, the light from the excitation light source was passed through a diffraction grating spectrometer having a focal length of 10 cm, and only the excitation light having a wavelength of 350 nm or more and 410 nm or less (peak wavelength was 395 nm) was irradiated to the phosphor through the optical fiber. The light generated from the phosphor by the irradiation of the excitation light is dispersed by a diffraction grating spectroscope having a focal length of 25 cm, the emission intensity of each wavelength is measured by a spectrum measuring device in a wavelength range of 400 nm to 800 nm, and a personal computer is used. An emission spectrum was obtained through signal processing such as sensitivity correction. In the measurement, the slit width of the light-receiving side spectroscope was set to 1 nm.

<Emission peak wavelength of phosphor and half-value width of emission peak>
The emission peak wavelength and the half width of the emission peak (hereinafter sometimes referred to as “half width”) were calculated from the emission spectrum of the phosphor obtained by the above method.

<Luminescent intensity ratio of phosphor I ₅₇₀ / I ₆₅₀ >
The emission intensity ratio I ₅₇₀ / I ₆₅₀ is the emission spectrum of the phosphor obtained by the above-mentioned method, wherein the emission intensity of the wavelength component of wavelength 570 nm is I ₅₇₀ , and the emission intensity of the wavelength component of wavelength 650 nm is I _650. It calculated by Formula [1 '].
_I570 / _I650 ... [1 ']
(However, I ₅₇₀ represents the emission intensity at 570 nm when the phosphor is excited with light having a peak wavelength of 395 nm, and I ₆₅₀ represents the emission intensity at ₆₅₀ nm when the phosphor is excited with light having a peak wavelength of 395 nm.)

<Area ratio S _L / S _R of emission spectrum of phosphor>
The area ratio S _L / S _R is the emission spectrum of the phosphor obtained by the above-described method, with the emission peak wavelength as the central axis, the total area of the emission spectrum is divided into two, and the light emission peak wavelength is shorter than the emission peak wavelength. The total area (S _L ) and the total area (S _R ) on the longer wavelength side than the emission peak wavelength were determined and calculated by the following formula [2 ′].
S _L / S _R ... [2 ′]
(However, S _L is than the emission peak wavelength of the emission spectrum measured by exciting the phosphor with light having a peak wavelength of 395nm represents the total area of the short wavelength side, S _R is exciting the phosphor with light having a peak wavelength of 395nm Represents the total area on the longer wavelength side of the emission peak wavelength of the emission spectrum measured in this manner.)

_{<Weight-average} median diameter _{D 50} of the phosphor>
The phosphor was added to ion-exchanged water and dispersed using an ultrasonic disperser for 120 seconds using an ultrasonic disperser (manufactured by Kaijo Co., Ltd.) with a frequency of 19 KHz and an ultrasonic intensity of 25 W. A small amount of a surfactant was added to the dispersion to prevent reaggregation.
The weight median diameter D ₅₀ is measured using a laser diffraction / scattering particle size distribution measuring device (LA-300, manufactured by Horiba, Ltd.) for the sample after ultrasonic dispersion, and a weight-based particle size distribution curve is obtained. After obtaining, the particle size value was calculated when the integrated value was 50%.

<Measurement of emission spectrum of light emitting device>
In a room maintained at 25 ° C. ± 1 ° C., the emission spectrum of the light emitted from the light emitting device obtained in each example and comparative example was measured using a fiber multichannel spectrometer (USB2000 manufactured by Ocean Optics). Further, the chromaticity coordinates (CIE X, CIE Y). The average color rendering index (Ra), special color rendering index (R9), luminous efficiency (Lumen / W), and color correlation temperature were measured.

[Manufacture of phosphor]
(Production Examples 1 to 3)
Each raw material powder was weighed in the amount (g) shown in Table 3-A and mixed with an alumina pestle and mortar for 20 minutes, and then the obtained raw material mixture was filled into a boron nitride crucible. In addition, all the steps of weighing and mixing the raw material powder were performed in a glove box capable of maintaining a nitrogen atmosphere with a moisture content of 1 ppm or less and oxygen of 1 ppm or less.

The boron nitride crucible containing the obtained raw material mixed powder was set in an electric furnace of a graphite resistance heating system. In the firing operation, first, the firing atmosphere is evacuated by a diffusion pump, the temperature is raised from room temperature to 800 ° C. at a rate of 500 ° C. per hour, and nitrogen having a purity of 99.999 vol% is introduced at 800 ° C. The maximum temperature was 1800 ° C. at 500 ° C. per hour, and held at this maximum temperature for 3 hours (the holding time at this maximum temperature is the firing time). After firing, the fired product obtained was roughly pulverized and then manually pulverized using an alumina mortar. Washing, dispersion, and classification were performed to obtain phosphor particles having a weight median diameter (D ₅₀ ) of 8 μm to 10 μm. As a result of powder X-ray diffraction measurement of the obtained phosphor, it was confirmed that an orthorhombic crystal phase of the same type as CaAlSiN ₃ was formed.

(Production Examples 4 to 6)
In Production Examples 1 to 3, except that the nitrogen pressure was 0.92 MPa and the firing time was 2 hours, weighed and mixed at the preparation weight shown in Table 3-A to produce a phosphor under the same conditions as above. did. As a result of powder X-ray diffraction measurement of the obtained phosphor, it was confirmed that an orthorhombic crystal phase of the same type as CaAlSiN ₃ was formed.

  The composition (prepared composition) of the phosphors obtained in Production Examples 1 to 6, and the emission peak wavelength and the half width measured by the above-described method are collectively shown in Table 3-B.

(Production Example 7)
Ca ₃ N ₂ (200 mesh pass manufactured by CERAC), AlN (grade F manufactured by Tokuyama Co.), Si ₃ N ₄ (SN-E10 manufactured by Ube Industries, Ltd.), Eu ₂ O ₃ (manufactured by Shin-Etsu Chemical Co., Ltd.), oxygen concentration In a glove box filled with nitrogen of 1 ppm or less, it was weighed by an electronic balance so that the molar ratio was Eu: Ca: Al: Si = 0.008: 0.992: 1: 1.14. In this glove box, all these phosphor materials were pulverized and mixed for 20 minutes in an alumina mortar until uniform. The obtained raw material mixture was filled in a boron nitride crucible and fired at 0.5 MPa of nitrogen and 1800 ° C. for 2 hours. Washing, dispersion, and classification were performed to obtain phosphor particles having a weight median diameter (D ₅₀ ) of 8 μm to 10 μm. As a result of powder X-ray diffraction measurement of the obtained phosphor, it was confirmed that an orthorhombic crystal phase of the same type as CaAlSiN ₃ was formed.
The composition of the obtained phosphor was a charge composition of Ca _0.992 Eu _0.008 AlSi _1.14 N _3.18 O _0.01 , the emission peak wavelength measured by the above method was 650 nm, The value width was 92 nm.

(Production Example 8)
Each metal was weighed so that the metal element composition ratio was Al: Si = 1: 1 (molar ratio), and after melting the raw material metal using a high-frequency induction melting furnace in an argon atmosphere using a graphite crucible, the crucible Was poured into a mold and solidified to obtain an alloy (mother alloy) having a metal element composition element ratio of Al: Si = 1: 1.
The mother alloy and other raw metals were weighed so that Eu: Sr: Ca: Al: Si = 0.008: 0.792: 0.2: 1: 1 (molar ratio). After evacuating the inside of the furnace to 5 × 10 ⁻² Pa, the evacuation was stopped, and the furnace was filled with argon to a predetermined pressure. After melting the master alloy in the calcia crucible, then dissolving Sr, adding Eu and Ca, and confirming that the molten metal with all the components melted is stirred by the induced current, the molten metal from the crucible is cooled with water. The molten metal was poured into a mold (plate shape with a thickness of 40 mm) and solidified.
The obtained plate-like alloy having a thickness of about 40 mm and a weight of about 5 kg was subjected to composition analysis by ICP emission spectroscopy (hereinafter sometimes referred to as “ICP method”). About 10g was sampled from one point near the center of gravity of the plate and one point near the end face of the plate, and elemental analysis was performed by ICP method.
Central part of plate Eu: Sr: Ca: Al: Si = 0.000: 0.782: 0.212: 1: 0.986,
End face of the plate Eu: Sr: Ca: Al: Si = 0.000: 0.756: 0.21: 1: 0.962
The composition was substantially the same in the range of analysis accuracy. Therefore, it was considered that each element including Eu was distributed uniformly.

The obtained plate-shaped alloy lump was coarsely pulverized to about 1 mm using an alumina mortar in a nitrogen atmosphere. Subsequently, using a supersonic jet pulverizer (“PJM-80SP” manufactured by Nippon Pneumatic Industry Co., Ltd.), a pulverization pressure of 0. 0 under a nitrogen atmosphere (oxygen concentration 2%) so that the weight median diameter D50 is 14 μm. Grinding was performed at 15 MPa and a raw material supply rate of 0.8 kg / hr. Thereafter, coarse particles were removed by passing through a sieve having an aperture of 53 μm to obtain an alloy powder.
The obtained alloy powder is filled in a boron nitride tray, set in a hot isostatic press (HIP), evacuated to 5 × 10 ⁻¹ Pa, and then heated to 300 ° C. The evacuation was continued at 300 ° C. for 1 hour. Thereafter, filling with 1 MPa of nitrogen, releasing the pressure to 0.1 Pa after cooling, and then filling with nitrogen again to 1 MPa were repeated twice. Thereafter, while maintaining the internal pressure of the apparatus at 190 MPa, it was heated to 1900 ° C. at a temperature rising rate of 10 ° C./min, and kept at this temperature for 1 hour to obtain a phosphor. Washing, dispersion, and classification were performed to obtain phosphor particles having a weight median diameter (D ₅₀ ) of 8 μm to 10 μm.

As a result of powder X-ray diffraction measurement of the obtained phosphor, it was confirmed that an orthorhombic crystal phase of the same type as CaAlSiN ₃ was formed.
The composition of the obtained phosphor was Sr _0.792 Ca _0.2 Eu _0.008 AlSiN ₃ in the charge composition, the emission peak wavelength measured by the above method was 630 nm, and the half width was 90 nm. .

The emission spectra of the phosphors obtained in Production Examples 1, 2, 4, and 6 to 8 (when light having a peak wavelength of 395 nm is used as the excitation wavelength) are shown in FIG. 4 and the phosphor obtained in Production Example 2 FIG. 5 shows an emission spectrum (when light having a peak wavelength of 395 nm and light having a peak wavelength of 455 nm are used as excitation wavelengths).
From FIG. 4, it can be seen that the spectrum of the red phosphors of Production Examples 1 to 6 spreads to the short wavelength side as compared with the conventional red phosphors (Production Examples 7 and 8).
FIG. 5 shows that the spectrum spread toward the short wavelength side is particularly large in the case of 395 nm excitation.

(Production Example 9)
As phosphor raw materials, powders of barium carbonate (BaCO ₃ ), strontium carbonate (SrCO ₃ ), europium oxide (Eu ₂ O ₃ ), and silicon dioxide (SiO ₂ ) were used. All of these phosphor raw materials had a purity of 99.9% or more and a weight median diameter (D ₅₀ ) in the range of 10 nm or more and 5 μm or less. These phosphor materials were weighed so that the molar ratio would be Ba: Sr: Eu: Si = 1.39: 0.46: 0.15: 1. These phosphor raw material powders were mixed in an automatic mortar until sufficiently uniform, filled in an alumina crucible, and fired at 1000 ° C. for 12 hours in air at atmospheric pressure. Next, the contents of the crucible were taken out, and SrCl ₂ as a flux was added so as to have a molar ratio of 0.1 with respect to Si, and mixed and pulverized by a dry ball mill. The obtained mixed pulverized product was again filled into an alumina crucible. At the time of firing, raw materials were packed in a crucible, and solid carbon (block shape) was placed thereon and covered. After reducing the pressure to 2 Pa with a vacuum pump in a vacuum furnace, hydrogen-containing nitrogen gas (nitrogen: hydrogen = 96: 4 (volume ratio)) was introduced until atmospheric pressure was reached. After repeating this operation again, firing was performed by heating at 1200 ° C. for 4 hours under atmospheric pressure under flowing hydrogen-containing nitrogen gas (nitrogen: hydrogen = 96: 4 (volume ratio)). After the obtained fired product is crushed with a ball mill, coarse particles are removed through a sieve while in a slurry state, washed with water, rinsed with water, washed away with fine particles, dried, and sieved to break up the agglomerated particles. The phosphor was manufactured by finishing.
The composition of the obtained phosphor was a charged composition of Ba _1.39 Sr _0.46 Eu _0.46 SiO ₄ , the emission peak wavelength measured by the above-mentioned method was 525 nm, and the half width was 65 nm. .

(Production Example 10)
As phosphor materials, 0.552 g of barium carbonate (BaCO ₃ ), 0.211 g of europium oxide (Eu ₂ O ₃ ), 0.261 g of basic magnesium carbonate (mass per mol of 93.17), manganese carbonate (MnCO ₃ ) 0.138 g and α-alumina (Al ₂ O ₃ ) 2.038 g, and as a flux, 0.015 g of potassium fluoride (KF) which is a halide of a monovalent metal element (total weighing of the phosphor raw materials) 0.47% by weight) was weighed and used.

The phosphor raw material and the flux described above were mixed in a mortar for 30 minutes and filled in an alumina crucible. In order to generate a reducing atmosphere during firing, beaded graphite was placed in the space around the crucible. This phosphor material and flux mixture was fired at 1550 ° C. for 2 hours under atmospheric pressure. The obtained fired product was crushed to obtain a phosphor.
The composition of the obtained phosphor was a charged composition of Ba _0.7 Eu _0.3 Mg _0.7 Mn _0.3 Al ₁₀ O ₁₇ , and the emission peak wavelength measured by the above method was 517 nm. The value width was 27 nm.

(Production Example 11)
A BaMgAl ₁₀ O ₁₇ : Eu, Mn phosphor (product model number: LP-G3) commercially available from Kasei Optonics, Inc. was used.

(Production Example 12)
An alkaline earth metal apatite phosphor (Ca, Sr) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu (product model number: LP-B1-B6) commercially available from Kasei Optonics was used.

(Production Example 13)
An alkaline earth metal apatite phosphor (Ca, Sr) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu (product model number: LP-B1-B10) commercially available from Kasei Optonics was used.

[Manufacture of sealing materials]
(Production Example 14)
GE Toshiba Silicone's both-end silanol dimethyl silicone oil XC96-723 1400g and phenyltrimethoxysilane 140g, zirconium tetraacetylacetonate powder 3.08g as a catalyst was weighed into a three-necked Kolben equipped with a stirring blade and a condenser, Stir at room temperature for 15 minutes until the catalyst is fully dissolved. Thereafter, the temperature of the reaction solution was raised to 120 ° C., and initial hydrolysis was performed while stirring at 120 ° C. under total reflux for 30 minutes. Subsequently, nitrogen was blown in with SV20 and stirred at 120 ° C. while distilling off the generated methanol, moisture and by-product low boiling silicon components, and the polymerization reaction was further advanced for 6 hours.
Here, “SV” is an abbreviation for “Space Velocity” and refers to the volume of blown volume per unit time. Thus, SV20 refers to blowing N ₂ in a volume 20 times that of the reaction solution in one hour.
After stopping the blowing of nitrogen and cooling the reaction solution to room temperature, the reaction solution was transferred to an eggplant-shaped flask, and methanol and moisture remaining in a minute amount at 120 ° C. and 1 kPa on an oil bath using a rotary evaporator, The low boiling silicon component was distilled off to obtain a silicate compound A which is a solvent-free sealing material.

(Production Example 15)
Momentive Performance Materials Japan G.K. both ends silanol dimethyl silicone oil XC96-723 385g, methyltrimethoxysilane 10.28g, and zirconium tetraacetylacetonate powder 0.791g as a catalyst, The solution was weighed into a 500 ml three-necked Kolben equipped with a fractionating tube, a Dimroth condenser, and a Liebig condenser, and stirred at room temperature for 15 minutes until the coarse particles of the catalyst were dissolved. Thereafter, the temperature of the reaction solution was raised to 100 ° C. to completely dissolve the catalyst, and initial hydrolysis was performed while stirring at 500 rpm for 30 minutes at 100 ° C. under total reflux.
Subsequently, the distillate was connected to the Liebig condenser side, and nitrogen was blown into the liquid with SV20, and methanol, moisture, and low-boiling silicon components of by-products were distilled off accompanying nitrogen and 100 ° C at 500 rpm. Stir for hours. The polymerization reaction was continued for 5.5 hours while the temperature was further raised and maintained at 130 ° C. while blowing nitrogen into the liquid with SV20 to obtain a reaction liquid having a viscosity of 389 mPa · s.
After stopping the blowing of nitrogen and cooling the reaction solution to room temperature, the reaction solution was transferred to an eggplant-shaped flask, and methanol and moisture remaining in a minute amount at 120 ° C. and 1 kPa on an oil bath using a rotary evaporator, The low boiling silicon component was distilled off to obtain a silicate compound B which is a solvent-free sealing material having a viscosity of 584 mPa · s.

[Examples 1 to 6, Comparative Examples 1 and 2]
A light-emitting device similar to the light-emitting device shown in FIG.

<Creation of semiconductor light emitting device>
As the first light emitter (22), C395-MB290 manufactured by Cree, which is an LED that emits light at a wavelength of 380 to 405 nm, was used. This near-ultraviolet LED (22) is silver paste as an adhesive on the terminal at the bottom of the recess of the SMD LED package “TY-SMD1202” (2.8 mm × 3.5 mm × 1.9 mm) (24) manufactured by Toyo Denki Co., Ltd. Was die-bonded. At this time, the silver paste as the adhesive was applied thinly and uniformly in consideration of the heat dissipation of the heat generated in the near ultraviolet LED (22). After heating at 150 ° C. for 2 hours to cure the silver paste, the near-ultraviolet LED (22) and the electrode (26) of the frame (24) were wire-bonded. A gold wire having a diameter of 25 μm was used as the wire (25).

<Preparation of phosphor-containing composition>
As the luminescent material of the phosphor-containing portion (second luminescent material) (23), a red fluorescent material having an emission peak in a wavelength range of approximately 580 nm to 650 nm and a green fluorescent light having an emission peak in a wavelength range of approximately 470 nm to 680 nm. And a blue phosphor showing an emission peak in the wavelength range of approximately 420 nm to 470 nm were used. Table 4 shows the phosphors used and their mixing weight ratios.

  Hydrophobic fumed silica (Aerosil RX200 manufactured by Nippon Aerosil Co., Ltd.) was mixed at 13.5 wt% with respect to the silicate compound A obtained in Production Example 14 to obtain a hydrophobic silica mixture. A phosphor-containing composition was obtained so that the total weight of the phosphor was 14.5% by weight with respect to this fumed silica mixture. The obtained phosphor-containing composition was degassed under reduced pressure, then poured into the recesses of the above-mentioned package, and cured by heating at 90 ° C. for 2 hours, 110 ° C. for 1 hour, and further at 150 ° C. for 3 hours. The phosphor-containing part (23) was formed to obtain a light emitting device.

The emission spectra of the obtained light emitting device are shown in FIGS.
Table 7 shows the average color rendering index (Ra), special color rendering index (R9), luminous efficiency, color correlation temperature, and chromaticity coordinates of the obtained light emitting device. Note that the emission spectrum was measured by driving a light emitting device by supplying a current of 20 mA.
Table 7 also shows the composition ratio and light emission characteristics (I ₅₇₀ / I ₆₅₀ and S _L / S _R ) of the red phosphor used in the light emitting device.

[Examples 7 to 9, Comparative Examples 3 and 4]
After fixing a 900 μm square chip “C405-XB900” manufactured by Cree onto a submount with Au—Sn eutectic solder, the submount is bonded to Au—Sn eutectic solder with a 9 mmφ metal package “Metal LED 3 PIN” manufactured by MC It was fixed to the center of “No Cup”. This package has a nickel plating on the surface of the copper material and a silver plating on the outermost surface layer. The electrode (pin) material is Kovar, and one of the three electrodes is directly connected to the package, and the other two are hermetically sealed with low melting point glass and insulated from the package. Wire bonding was performed from one electrode on the chip to one of hermetically sealed electrodes on the metal package with a gold wire. The remaining one hermetically sealed pin was unused.

<Preparation of phosphor-containing composition>
As the luminescent material of the phosphor-containing portion, a red phosphor showing an emission peak in a wavelength range of approximately 580 nm to 650 nm, a green phosphor showing an emission peak in a wavelength range of approximately 470 nm to 680 nm, and a wavelength range of approximately 420 nm to 470 nm. A blue phosphor showing an emission peak was used. Table 5 shows the phosphors used and the mixing weight ratio thereof.

  Hydrophobic fumed silica (Aerosil RX200 manufactured by Nippon Aerosil Co., Ltd.) was mixed at 13.5% by weight with respect to the solid content of the silicate compound B obtained in Production Example 15 to obtain a hydrophobic silica mixture. It was. A phosphor-containing composition was obtained so that the total weight of the phosphor was 18.5% by weight with respect to the solid content of the fumed silica mixture. The obtained phosphor-containing composition was degassed under reduced pressure, then poured into the recesses of the above-mentioned package, and cured by heating at 90 ° C. for 2 hours, 110 ° C. for 1 hour, and further at 150 ° C. for 3 hours. A phosphor-containing resin part was formed to obtain a light emitting device.

The emission spectra of the obtained light emitting device are shown in FIGS.
Table 7 shows the average color rendering index (Ra), special color rendering index (R9), luminous efficiency, color correlation temperature, and chromaticity coordinates of the obtained light emitting device. Note that the emission spectrum was measured by driving the light emitting device by supplying a current of 350 mA to the light emitting device. At this time, in order to prevent the temperature rise of the light emitting device, heat was radiated with a 3 mm thick aluminum plate through a heat conductive insulating sheet.
Table 7 also shows the composition ratio and light emission characteristics (I ₅₇₀ / I ₆₅₀ and S _L / S _R ) of the red phosphor used in the light emitting device.

[Examples 10 to 15, Comparative Examples 5 and 6]
Except that the mixing ratio of the phosphors was changed as shown in Table 6, the light emitting device was prepared and measured in the same manner as [Examples 1 to 6, Comparative Examples 1 and 2].

The emission spectrum of the obtained light emitting device is shown in FIGS.
Table 7 shows the average color rendering index (Ra), special color rendering index (R9), luminous efficiency, color correlation temperature, and chromaticity coordinates of the obtained light emitting device.
Table 7 also shows the composition ratio and light emission characteristics (I ₅₇₀ / I ₆₅₀ and S _L / S _R ) of the red phosphor used in the light emitting device.

  From Table 7, the light-emitting device of the present invention using a near-ultraviolet LED as an excitation source and a red phosphor having specific emission characteristics in combination with a green phosphor and a blue phosphor is excellent in color rendering and luminous efficiency. I understand.

It is a typical perspective view which shows one Example of the light-emitting device of this invention. FIG. 2A is a schematic cross-sectional view showing an embodiment of a bullet-type light emitting device of the present invention, and FIG. 2B is a schematic view showing an embodiment of the surface-mounted light-emitting device of the present invention. It is sectional drawing. It is typical sectional drawing which shows one Example of the illuminating device using the light-emitting device of this invention. It is a chart which shows the emission spectrum in 395 nm excitation of the fluorescent substance manufactured by manufacture example 1,2,4,6-8. 6 is a chart showing an emission spectrum of the phosphor manufactured in Production Example 2 when excited at 395 nm and 455 nm. 3 is a chart showing an emission spectrum of the light emitting device of Example 1. FIG. 6 is a chart showing an emission spectrum of the light emitting device of Example 2. 6 is a chart showing an emission spectrum of the light emitting device of Example 3. 6 is a chart showing an emission spectrum of the light emitting device of Example 4. 6 is a chart showing an emission spectrum of the light emitting device of Comparative Example 1. 10 is a chart showing an emission spectrum of the light emitting device of Comparative Example 2. 10 is a chart showing an emission spectrum of the light emitting device of Example 5. 10 is a chart showing an emission spectrum of the light emitting device of Example 6. 10 is a chart showing an emission spectrum of the light emitting device of Example 7. 10 is a chart showing an emission spectrum of the light emitting device of Example 8. 10 is a chart showing an emission spectrum of the light emitting device of Example 9. 10 is a chart showing an emission spectrum of the light emitting device of Comparative Example 3. 10 is a chart showing an emission spectrum of the light emitting device of Comparative Example 4. It is a chart which shows the emission spectrum of the light-emitting device of Example 10. 10 is a chart showing an emission spectrum of the light emitting device of Example 11. 14 is a chart showing an emission spectrum of the light emitting device of Example 12. 14 is a chart showing an emission spectrum of the light emitting device of Example 13. 10 is a chart showing an emission spectrum of the light emitting device of Comparative Example 5. 10 is a chart showing an emission spectrum of the light emitting device of Comparative Example 6. It is a chart which shows the emission spectrum of the light-emitting device of Example 14. 16 is a chart showing an emission spectrum of the light emitting device of Example 15.

Explanation of symbols

1 Phosphor-containing part (second light emitter)
2 Excitation light source (first light emitter) (LD)
3 Substrate 4 Light-emitting device 5 Mount lead 6 Inner lead 7 Excitation light source (first light emitter)
8 Phosphor-containing resin part 9 Conductive wire 10 Mold member 11 Surface emitting illumination device 12 Holding case 13 Light emitting device 14 Diffusion plate 22 Excitation light source (first light emitter) (LED)
23 Phosphor-containing part (second light emitter)
24 frame 25 conductive wire 26 electrode 27 electrode

Claims (11)

A first light emitter, and a second light emitter that emits visible light by irradiation of light from the first light emitter,
The first light emitter has a light emission peak in a wavelength range of 300 nm or more and 420 nm or less;
The second phosphor is one or more of red phosphors satisfying the following formula [1], and one or more of green phosphors having an emission peak in the wavelength range of 510 nm or more and 545 nm or less; And a blue phosphor having a light emission peak in a wavelength range of 420 nm or more and 470 nm or less.
I ₅₇₀ / I ₆₅₀ ≧ 0.3 ... [1]
(In the above formula [1],
I ₅₇₀ represents the emission intensity at 570 nm when the red phosphor is excited with light having a peak wavelength of 395 nm,
I ₆₅₀ represents the emission intensity at 650 nm when the red phosphor is excited with light having a peak wavelength of 395 nm. ) The light emitting device according to claim 1, wherein the red phosphor further satisfies the following formula [2].
S _L / S _R ≧ 1.56 ... [2]
(In the above equation [2],
S _L represents the total area on the short wavelength side of the emission peak wavelength of the emission spectrum measured by exciting the red phosphor with light having a peak wavelength of 395 nm,
S _R represents the total area on the longer wavelength side of the emission peak wavelength of the emission spectrum measured by exciting the red phosphor with light having a peak wavelength of 395 nm. ) The green phosphor is a phosphor having an oxide or oxynitride containing Si containing Eu as an activator as a base, and a half-value width of the emission peak of 45 to 70 nm,
3. The light emitting device according to claim 1, wherein the blue phosphor is a phosphor having a half-value width of an emission peak of not less than 45 nm and not more than 70 nm. The green phosphor is (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, Mn, β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu and one or more selected from the group consisting of (Ca, Sr, Ba) Si ₂ N ₂ O ₂ : Eu,
4. The light emission according to claim 1, wherein the blue phosphor contains one or more selected from the group consisting of (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu. 5. apparatus. When the light emitted from the light emitting device is expressed in an XYZ color system,
The value of the chromaticity coordinate x is in the range of 0.39 to 0.475,
2. The light emitting device according to claim 1, wherein a value of the chromaticity coordinate y is in a range of 0.375 to 0.425.   6. The light emitting device according to claim 5, wherein the luminous efficiency when driven at a current of 20 mA is 10 lm / W or more.   The light emitting device according to claim 5 or 6, wherein the average color rendering index (Ra) is 80 or more and the special color rendering index (R9) is 27 or more. The green phosphor is (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, Mn, β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu and one or more selected from the group consisting of (Ca, Sr, Ba) Si ₂ N ₂ O ₂ : Eu,
The blue phosphor is selected from the group consisting of (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu and (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu The light-emitting device according to claim 5, wherein the light-emitting device contains seeds or more. The light emitting device according to claim 1, wherein the red phosphor contains a crystal phase having a chemical composition represented by the following formula [3].
(1-a-b) ( Eu y Ln 'w M II' 1-yw M III 'M IV' N 3)
・ A (M ^{IV ′} _{(3n + 2) / 4} N _n O) ・ b (AM ^{IV ′} ₂ N ₃ ) ... [3]
(In the above equation [3],
Ln ′ is at least one metal element selected from the group consisting of lanthanoids excluding Eu, Mn and Ti,
M ^{II ′} is one or more elements selected from the group consisting of divalent metal elements other than Eu and Ln ′ elements;
M ^{III ′} is one or more elements selected from the group consisting of trivalent metal elements,
M ^{IV ′} is one or more elements selected from the group consisting of tetravalent metal elements,
A is one or more monovalent metal elements selected from the group consisting of Li, Na, and K;
y is a number satisfying 0 <y ≦ 0.2,
w is a number satisfying 0 ≦ w <0.2;
a, b, and n are numbers satisfying 0 ≦ a, 0 ≦ b, a + b> 0, 0 ≦ n, and 0.002 ≦ (3n + 2) a / 4 ≦ 0.9. ) The light-emitting device according to claim 9, wherein the red phosphor contains a crystal phase having a chemical composition represented by the following formula [4].
_{(Eu y Ln '' w M} II 1-yw M III M IV N 3) 1-x (M IV (3n + 2) / 4 N n O) x ... [4]
(In the above equation [4],
Ln ″ is at least one metal element selected from the group consisting of lanthanoids excluding Eu, Mn and Ti,
M ^II is one or more elements selected from the group consisting of divalent metal elements in which the total of Mg, Ca, Sr, Ba, and Zn occupies 90 mol% or more,
M ^III is one or more elements selected from the group consisting of trivalent metal elements in which Al accounts for 80 mol% or more,
M ^IV is one or more elements selected from the group consisting of tetravalent metal elements in which Si accounts for 90 mol% or more,
y is a number satisfying 0 <y ≦ 0.2,
w is a number satisfying 0 ≦ w <0.2;
x is a number satisfying 0 <x ≦ 0.45,
n is a number satisfying 0 ≦ n,
n and x are numbers satisfying 0.002 ≦ (3n + 2) x / 4 ≦ 0.9. ) The light emitting device according to claim 9, wherein the red phosphor contains a crystal phase having a chemical composition represented by the following formula [5].
_{(Eu y Ln '' w M} II 1-yw M III M IV N 3) 1-x '(AM IV 2 N 3) x' ... [5]
(In the above equation [5],
Ln ″ is a lanthanoid excluding Eu,
At least one metal element selected from the group consisting of Mn and Ti,
M ^II is one or more elements selected from the group consisting of divalent metal elements in which the total of Mg, Ca, Sr, Ba, and Zn occupies 90 mol% or more,
M ^III is one or more elements selected from the group consisting of trivalent metal elements in which Al accounts for 80 mol% or more,
M ^IV is one or more elements selected from the group consisting of tetravalent metal elements in which Si accounts for 90 mol% or more,
A is one or more metal elements selected from the group consisting of Li, Na, and K;
x ′ is a number satisfying 0 <x ′ <1.0,
y is a number satisfying 0 <y ≦ 0.2,
w is a number satisfying 0 ≦ w <0.2. )

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