JP2018021193A - Sintered phosphor, light-emitting device, illumination device, image display device and indicator lamp for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sintered phosphor for an LED, having high internal quantum efficiency and transmittance, particularly, a sintered phosphor that can give light emission at a low color temperature, and a light-emitting device, an illumination device, and an indicator lamp for a vehicle, which emit light at a low color temperature with high emission efficiency, high luminance and a large amount of a red color component and prevents changes in brightness or color shift due to changes in the intensity of excitation light and temperature.SOLUTION: The sintered phosphor comprises a nitride phosphor and a fluoride inorganic binder. The nitride phosphor comprises a crystal phase represented by formula [1] LaASiNM, where M element represents at least one element selected from activating elements; A element represents at least one element selected from rare earth elements excluding La and activating elements; and w, x, y and z satisfy 2.0≤w≤4.0, 0<x≤1.5, 8.0≤y≤14.0 and 0.05≤z≤1.0.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sintered phosphor containing a nitride phosphor and a fluoride inorganic binder, a light emitting device using the sintered phosphor, an illumination device and an image display device using the light emitting device, and a vehicle display lamp.

A light emitting diode (LED) is widely known as a semiconductor light emitting device or a semiconductor light source capable of generating light having a peak wavelength in a specific region of a light spectrum.
LEDs are usually used as light sources for illuminators, signs, vehicle headlamps and displays. As a light emitting device using an LED and a phosphor, an LED chip that emits blue light,
YAG (yttrium, aluminum, garnet) phosphor that converts blue light into yellow,
There is known a light emitting device that emits white light in combination. The YAG phosphor is disposed around the LED chip as a wavelength conversion light emitting layer dispersed in an epoxy resin or a silicone resin. In addition to the wavelength-converted light-emitting layer dispersed in the resin, a ceramic layer made of a phosphor or a wavelength-converted light-emitting layer (light-emitting ceramic layer) made only of an inorganic material in which the phosphor is dispersed in ceramic is exemplified. (Patent Document 1).

On the other hand, in recent years, many new materials have been manufactured for nitrides composed of elements of ternary or higher elements, and in recent years, in multi-system nitrides and oxynitrides based on silicon nitride,
Phosphor materials having excellent characteristics have been developed and used in wavelength-converted light-emitting layers. These phosphor materials are known to exhibit yellow or red light emission when excited by a blue LED or near-ultraviolet LED, and have higher luminance and higher conversion efficiency than oxide-based phosphors. ,
Furthermore, the temperature dependency of luminous efficiency is excellent (Patent Document 2).

Conventionally, a wavelength conversion light emitting layer dispersed in an organic binder such as an epoxy resin or a silicone resin has insufficient durability, heat resistance, and light emission intensity. Therefore, in order to obtain a wavelength-converting light-emitting layer with better durability and heat resistance, a method for producing a wavelength-converted light-emitting layer (light-emitting ceramic layer) made only of an inorganic material as exemplified in Patent Document 1 is studied. Has been.

In Patent Document 3, YAG: Ce phosphor particles are contained in an inorganic binder made of any one of calcium fluoride, strontium fluoride, and lanthanum fluoride, or made of calcium fluoride and strontium fluoride. Dispersed phosphor ceramics are illustrated.

In Patent Document 4, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce oxide phosphor, Lu ₃ Al ₅ O _1
2 : A combination of Ce oxide phosphor and CaSiAlN ₃ : Eu nitride phosphor is melted with a glass powder having a glass transition point of 200 ° C. or higher by using a discharge plasma sintering method, so that only from an inorganic material. The wavelength conversion light emitting layer which becomes is produced.

Special table 2008-502131 International Publication No. 2008/132951 International Publication No. 2009/154193 JP 2009-91546 A

However, in Patent Document 1, an aluminum garnet phosphor is used as the luminescent ceramic layer. This was obtained by producing a YAG powder from Y ₂ O ₃ , Al ₂ O ₃ (99.999%) and CeO ₂ , obtaining a molded body consisting only of YAG powder, and firing at 1300 ° C. YAG sintered phosphor is used as the luminescent ceramic layer. The luminescent ceramic layer does not use an inorganic binder and forms a sintered body only with a YAG oxide phosphor.
Therefore, there has been a demand for sintered phosphors of nitride phosphors that have high luminance, high conversion efficiency, and excellent temperature dependence of luminous efficiency.

Moreover, as exemplified in Patent Document 3, the ceramic composite of the YAG oxide phosphor phase and the fluoride matrix phase has a problem that the internal quantum efficiency is a low value of 55% or less.
In Patent Document 4, although a YAG oxide phosphor or a combination of a LuAG oxide phosphor and a CASN nitride phosphor is dispersed in glass by melting glass powder, a wavelength conversion light emitting layer is produced. Since the inorganic binder is glass, it has heat resistance, but its thermal conductivity is as low as 2 to 3 W / mK, and its heat dissipation is low, so the temperature of the phosphor rises and the brightness decreases (
There is a problem of phosphor deterioration.

In view of the above problems, the present invention provides a sintered phosphor for LED having high internal quantum efficiency and high transmittance. In particular, a sintered phosphor capable of obtaining light emission with a low color temperature is provided. In addition, by using the sintered phosphor, the light emission efficiency is high, the brightness is high, the brightness change and the color shift due to the change of the excitation light intensity and the temperature are small, and the light of the low color temperature with a lot of red component is emitted. Provided are a light emitting device that emits light, and an illumination device and a vehicle indicator lamp using the light emitting device.

Conventionally, when an oxide phosphor and a fluoride inorganic binder are sintered, in general, since the ionic radii of the oxygen of the phosphor and the fluorine of the inorganic binder are close, solid solution substitution occurs, and an oxyfluoride is formed. It was thought to cause a decrease in internal quantum efficiency. Accordingly, the inventors have found that when the nitride phosphor and the fluoride inorganic binder are mixed and sintered, the internal quantum efficiency of the original nitride phosphor can be maintained. . This is presumably because nitrogen and fluorine having different ionic radii did not easily undergo solid solution substitution, and it was possible to prevent a decrease in internal quantum efficiency.

Further, by using a fluoride inorganic binder, for example, the sintering temperature can be lowered as compared with the case where Al ₂ O ₃ is used as an inorganic binder, so that the reaction between the nitride phosphor and the inorganic binder is suppressed. Can be made. Thus, the present inventors have conceived that a sintered phosphor of a nitride phosphor having a high internal quantum efficiency can be obtained.
Furthermore, for example, Al ₂ O ₃ is a trigonal for having birefringence, when a sintered body Al ₂
Whereas O ₃ becomes a polycrystal and its translucency is insufficient, if a crystal inorganic system such as CaF ₂ , BaF ₂ , SrF ₂ or the like is used with a cubic fluoride inorganic binder, there is no birefringence and transparency. It is possible to manufacture a sintered phosphor having a high thickness.
Further, it has been found that a sintered phosphor suitable for illumination at a low color temperature can be obtained by using a nitride phosphor having specific physical properties and properties.

Accordingly, the present inventors have invented a sintered phosphor for LED that can develop a low color temperature with many red components and has high internal quantum efficiency and high transmittance by using a specific nitride phosphor. It came to. Furthermore, using this sintered phosphor, it is possible to emit light with a high color efficiency, high brightness, low brightness and high color components, low brightness and color shift due to changes in excitation light intensity and temperature, and a large amount of red component. It came to invent the outstanding light emitting device and illuminating device which can be performed.
That is, the present invention is a sintered phosphor containing a nitride phosphor and a fluoride inorganic binder,
The nitride phosphor is a phosphor including a crystal phase represented by the following formula [1], and is present in a sintered phosphor, a light emitting device, a lighting device, an image display device, and a vehicle display lamp. .
La _w A _x Si ₆ N _y M _z [1]
(M element in the formula represents one or more elements selected from activators,
The A element represents one or more elements selected from rare earth elements other than La and an activating element,
2.0 ≦ w ≦ 4.0,
0 <x ≦ 1.5,
8.0 ≦ y ≦ 14.0,
0.05 ≦ z ≦ 1.0)

According to the present invention, a sintered phosphor for LED having high internal quantum efficiency and high transmittance can be provided. In particular, a sintered phosphor capable of obtaining light emission with a low color temperature can be provided. In addition, by using the sintered phosphor, the light emission efficiency is high, the brightness is high, the brightness change and the color shift due to the change of the excitation light intensity and the temperature are small, and the light of the low color temperature with a lot of red component is emitted. Emitting light emitting device,
In addition, it is possible to provide a lighting device and a vehicle indicator lamp using the light-emitting device.

It is a schematic diagram which shows the structural example of the semiconductor light-emitting device which concerns on the embodiment of this invention. It is a schematic diagram which shows the structural example of the semiconductor light-emitting device which concerns on the embodiment of this invention. 2 is a powder X-ray diffraction pattern of the phosphor used in Example 1. FIG. 3 is a powder X-ray diffraction pattern of the phosphor used in Example 2. FIG. It is the emission spectrum figure by LED excitation of the sintered fluorescent substance of Example 1 and Example 2. FIG. It is a figure showing the simulation result of the emission spectrum by LED excitation of the sintered fluorescent substance of Example 3. It is a figure showing the simulation result of the emission spectrum by LED excitation of the sintered fluorescent substance of Example 4. It is a figure showing the simulation result of the emission spectrum by LED excitation of the sintered fluorescent substance of Examples 5-8. It is a figure showing the simulation result of the emission spectrum by LED excitation of the sintered fluorescent substance of Examples 9-12. It is a figure which shows the emission spectrum by LED excitation of the sintered fluorescent substance of Example 13,14.

{Sintered phosphor}
A sintered phosphor according to an embodiment of the present invention includes a nitride phosphor and a fluoride inorganic binder, and the nitride phosphor includes a crystal phase represented by the above formula [1] (hereinafter, referred to as “phosphor”). It may be referred to as “formula [1] phosphor”.

[Form of sintered phosphor]
The sintered phosphor in the present invention is not particularly limited as long as it is a composite composed of a nitride phosphor containing the formula [1] phosphor and a fluoride inorganic binder, but preferably, the nitride phosphor is a fluoride. Is a composite that is dispersed in a fluoride inorganic binder and holds a phosphor mainly by sintering crystalline inorganic binders, wherein the nitride phosphor and the fluoride inorganic binder are physically and / or It is a complex integrated by chemical bonding. By combining nitrides and fluorides with different ionic radii, it is possible to suppress the reaction between the nitride phosphor and the fluoride inorganic binder during sintering, and obtain a sintered phosphor with high internal quantum efficiency. is there.
Such a sintered phosphor can be obtained by observing the surface of the sintered phosphor with a scanning electron microscope, cutting out the cross section by cutting the sintered phosphor, or creating a cross section of the sintered phosphor with a cross section polisher. Observation is possible by an observation method such as cross-sectional observation of a sintered phosphor by a scanning electron microscope.

[Nitride phosphor]
In the sintered phosphor according to the embodiment of the present invention, as a method for confirming the presence of the nitride phosphor, the identification of the nitride phosphor phase by X-ray diffraction and the energy dispersive X-ray analyzer are used. Elemental analysis of particles, elemental analysis by fluorescent X-rays, etc.

The sintered phosphor of the present embodiment contains a phosphor containing a crystal phase represented by the following formula [1].
La _w A _x Si ₆ N _y M _z [1]
(In Formula [1],
M element represents one or more elements selected from activators,
The A element represents one or more elements selected from rare earth elements other than La and an activating element,
2.0 ≦ w ≦ 4.0,
0 <x ≦ 1.5,
8.0 ≦ y ≦ 14.0,
0.05 ≦ z ≦ 1.0)
M element is an active element such as europium (Eu), cerium (Ce), manganese (
Mn), iron (Fe), praseodymium (Pr) and the like.

As the M element, one kind of element may be used alone, or two or more different kinds of elements may be included. Among them, the M element preferably contains Eu or Ce, more preferably contains 80 mol% or more of Ce in all the activation elements, and further preferably contains 95 mol% or more of Ce in all the activation elements, Ce It is most preferable to contain alone.
La represents lanthanum.

The element A is preferably yttrium (Y), gadolinium (Gd), or lutetium (Lu), more preferably Y and Gd, and particularly preferably Y. By including the element A, the phosphor of the formula [1] has a light emission wavelength shifted to a long wavelength, and exhibits a light emission spectrum suitable for use as various light emitting devices.
x represents the content of element A, and is usually in the range of 0 <x ≦ 1.5, and the lower limit is preferably 0.1, more preferably 0.2, still more preferably 0.3, The upper limit value is preferably 1.0, more preferably 0.7.

Within the above range, the emission intensity is unlikely to decrease, which is preferable.
w represents the content of La and is usually in the range of 2.0 ≦ w ≦ 4.0.
The sum of w, x, and z is preferably 3 in terms of the crystal structure, but may be a value other than 3 due to the presence of lattice defects, interstitial elements, and impurity elements. Incidentally, the increase or decrease of 30 to 20%, which is the stoichiometric ratio, is a range in which the crystal structure is maintained. y represents the content of N, usually 8.0 ≦ y ≦ 14.
A range of zero. Although y is preferably 11 in terms of the crystal structure, it may be a value other than 11 due to the presence of lattice defects, interstitial elements, and impurity elements.
z represents the content of M element, and is generally 0.05 ≦ z ≦ 1.0. The lower limit is preferably 0.10, more preferably 0.2, and the upper limit is preferably 0.95. More preferably, it is 0.9.
Within the above range, concentration quenching is difficult and light emission intensity is hardly lowered.

In addition, the mass ratio of oxygen atoms in the phosphor of formula [1] is preferably 5.0% or less, more preferably 3.0% or less, and even more preferably 1.0% or less. Since nitride phosphors inevitably contain oxygen, the lower limit is usually greater than 0%. It is preferable for it to be within the above-mentioned range since the resulting sintered phosphor has good luminance.

[Formula [1] Crystal structure of phosphor]
The phosphor of formula [1] has a tetragonal crystal structure reported by the composition formula of La ₃ Si ₆ N ₁₁ , and La, A element, and M element enter La at the position of the composition formula. Such element substitution results in crystals having different lattice constants and atomic coordinates while maintaining the basic skeleton structure.

(Lattice constant)
Reference 1 (Acta Crystallographica. Section E, vol. 70, page i23 (2014))
According to the above, La ₃ Si ₆ N ₁₁ is a tetragonal crystal having a P4bm space group, and its lattice constant a = 10.1098Å. c = 4.841153.
The phosphor of the formula [1] is based on La ₃ Si ₆ N ₁₁ and is obtained by substituting Y, Gd or the like having an ionic radius smaller than La in place of La, and the lattice constant is as follows.
The a-axis lattice constant (lattice constant a) is usually a value satisfying 10.104 cm or more and 10.185 mm or less, and the lower limit value thereof is preferably 10.109 cm, more preferably 10.114.
The upper limit is preferably 10.17 cm, and more preferably 10.16 cm.

The b-axis lattice constant (lattice constant b) is the same value as the lattice constant a.
The c-axis lattice constant (lattice constant c) is a value that usually satisfies 4.820Å or more and 4.860Å or less, and the lower limit thereof is preferably 4.825 、, more preferably 4.830Å.
Moreover, the upper limit is preferably 4.865cm, more preferably 4.860cm.
When the lattice constant a is within the above range, a phosphor exhibiting an emission spectrum suitable for illumination at a low color temperature below 5000K is preferable. The same applies to the lattice constant c.
In particular, it is particularly preferable that the lattice constant a is 10.154 mm or less because a phosphor exhibiting an emission spectrum suitable for light bulb color illumination can be obtained.

The above lattice constant, the formula [1] The powder X-ray diffraction pattern of the phosphor _La 3 _Si 6 _{N 1}
It is applied to the diffraction pattern estimated from the tetragonal crystal structure of the space group P4bm reported as the crystal structure of ₁ , and the diffraction angle data of the powder X-ray diffraction of the phosphor and the index of the diffraction are used. Ask. Although it can be calculated using a specific diffraction line and its index, it is usually calculated by pattern fitting (for example, Rietveld analysis method) using a plurality of diffraction lines or all measured diffraction lines.

{Formula [1] Characteristics of phosphor}
[Luminescent color]
Formula [1] phosphor emits light when excited by irradiating excitation light having a wavelength of 455 nm.
The chromaticity coordinates x and y expressed in the CIE (International Commission on Illumination) 1931XYZ color system preferably satisfy the following formula.
0.43 ≦ x ≦ 0.50,
0.48 ≦ y ≦ 0.55
The chromaticity coordinates x and y are calculated using the spectrum of only the phosphor excluding the excitation light that was not absorbed by the phosphor from the measured spectrum.

The value of the chromaticity coordinate x is more preferably 0.44 or more, further preferably 0.45 or more, and 0
. 46 or more is particularly preferable. 0.495 or less is more preferable, and 0.49 or less is more preferable. By taking such a range, it is preferable because warm emission (bulb color) of white light of 3000K to 5000K can be obtained when excited with a gallium nitride blue LED or laser.
The value of the chromaticity coordinate y changes in conjunction with the value of the chromaticity coordinate x. That is, as x increases, y decreases. The preferred range of y is 0.48 or more, more preferably 0.49 or more, preferably 0.55 or less, and more preferably 0.54 or less.

[Emission spectrum]
The phosphor of formula [1] preferably has the following characteristics when an emission spectrum is measured when excited by light having a wavelength of 300 nm or more and 460 nm or less.
The phosphor of the present invention has a peak wavelength in the above-mentioned emission spectrum of usually 546 nm or more, preferably 550 nm or more, and usually 570 nm or less, preferably 565 nm or less. Within the above range, the obtained phosphor is preferable in that it exhibits a good green or yellow color.

[Formula [1] Particle Size of Phosphor]
The volume median diameter of the formula [1] phosphor is usually 0.1 μm or more, preferably 0.5 μm or more, and is usually 35 μm or less, preferably 25 μm or less. By setting it as the said range, since the fall of a brightness | luminance is suppressed and aggregation of a fluorescent substance particle can be suppressed, it is preferable. The volume median diameter can be measured by, for example, a Coulter counter method, and a typical apparatus is a precision particle size distribution measuring device Multisizer (manufactured by Beckman Coulter, Inc.).

[Formula [1] Volume fraction of phosphor]
The volume fraction of the formula [1] phosphor with respect to the total volume of the sintered phosphor is usually 1% or more and 50% or less. The volume fraction is affected by the size, thickness, shape, surface roughness, structure of the light emitting device, etc. of the sintered phosphor, and is a parameter that should be adjusted to obtain the desired emission color. If the volume fraction of the phosphor is too low, sufficient wavelength conversion cannot be performed, and if the volume fraction is too high, the wavelength conversion efficiency decreases, or the content of the fluoride inorganic binder is too low.
It becomes difficult to produce a sintered phosphor having an appropriate mechanical strength. For example, when a white or light bulb-colored light emitting device is configured using a sintered phosphor having a thickness of 200 microns, a preferable range of the volume fraction is 3% or more and 20% or less, and 15% or less. More preferably it is. If the thickness is reduced, the volume fraction is increased, and if the thickness is increased, the volume fraction is decreased.
In addition, when the sintered fluorescent substance of this embodiment contains fluorescent substance other than Formula [1] fluorescent substance, it is preferable that the said volume fraction becomes in the said range including another fluorescent substance.
In the sintered phosphor of the present embodiment, the formula [1] phosphor contained may be only one type, or may include two different types. Examples of the two different types include those having different compositions, different particle sizes, and different chromaticities.

{Formula [1] Method for producing phosphor}
The production method of the formula [1] phosphor is not particularly limited as long as the formula [1] phosphor and the effect thereof can be obtained, but a preferable production method will be described below.

[material]
As raw materials (La source, A source, Si source, M source) used in the present invention, for example, La, A element, Si, which are constituent elements of the phosphor matrix, and adjustment of emission wavelength, etc., as necessary Examples thereof include metals, alloys or compounds containing the activating element M added to.

Examples of La source, A source, Si source, and M source compounds include nitrides, oxides, hydroxides, carbonates, nitrates, sulfates, oxalates, and carboxylic acids of the respective elements constituting the phosphor. Examples include salts and halides. The specific type may be appropriately selected from these metal compounds in consideration of the reactivity to the target product or the low generation amount of NO _x , SO _x, etc. during firing. From the viewpoint that the phosphor is a nitrogen-containing phosphor, it is preferable to use a nitride and / or an oxynitride. Among them, it is preferable to use a nitride because it also serves as a nitrogen source.

Specific examples of nitrides and oxynitrides include nitrides of elements constituting phosphors such as LaN, Si ₃ N ₄ or CeN, and phosphors such as La ₃ Si ₆ N ₁₁ or LaSi ₃ N ₅ And a composite nitride of the element to be used.

Further, the phosphor matrix or the phosphor itself may be used as a part of the raw material. Since the phosphor matrix or phosphor has already finished the reaction to become the phosphor matrix, it only contributes to crystal growth, and the phosphor itself has the effect of controlling the crystal diameter and particle diameter in phosphor firing. This is because it can be expected.

(Mixing of raw materials)
When the phosphor production alloy is used, if the composition of the contained metal element matches the composition represented by the formula [1], only the phosphor production alloy, or flux if necessary (
What is necessary is just to mix and bake a growth adjuvant.
On the other hand, if the phosphor production alloy is not used or the composition does not match,
Phosphor production alloy having different composition, simple metal, metal compound, etc. are mixed with phosphor production alloy, and the composition of the metal element contained in the raw material matches the composition represented by the formula [1] Prepare and bake.

In the case of the phosphor of the present invention, the theoretical composition ratio of (La, A element) to Si and N is 3: 6: 11.
Since it is preferable that the charging composition is also the above stoichiometric ratio,
When producing a LYSN phosphor, a relatively larger amount of raw material than the composition of the target phosphor,
In particular, the La element is preferably charged. As a result, a crystal phase in which appropriate amounts of La element, A element, and M element are incorporated can be obtained, and a long wavelength LYSN with less impurity phase and high emission luminance.
A phosphor can be obtained.
In this case, the molar ratio of La or the element substituting La and La site is set to 1: 2 of the theoretical composition.
May be changed within a range of about 1: 1.5. This change in composition ratio is particularly preferable when the proportion of oxygen in the raw material is high.

A known method may be used for mixing the phosphor materials. A method of mixing with a solvent in a pot and crushing the raw material with a ball, a method of mixing by a dry method, and a mesh pass can be used. When dispersed and mixed in a solvent, it is a matter of course that the solvent is removed, and if necessary, dry aggregation is loosened. These operations are preferably performed in a nitrogen atmosphere.
In manufacturing the phosphor of the present invention, a flux may be used. Examples of the flux include International Publication No. 2008/132951 and International Publication No. 2010/114061.
Those described in each publication of the issue can be used.

[Baking process]
The raw material mixture thus obtained is usually filled in a container such as a crucible or a tray and stored in a heating furnace capable of controlling the atmosphere. At this time, the material of the container is preferably a material having low reactivity with the metal compound, and examples thereof include boron nitride, silicon nitride, carbon, aluminum nitride, molybdenum, and tungsten.

The firing temperature for the main firing is preferably 1300 ° C. or higher and 1900 ° C. or lower, more preferably 1400 ° C. or higher and 1700 ° C. or lower.
The main calcination is performed by heating the phosphor raw material in a state filled with hydrogen gas or in a state in which it is circulated, and the pressure at that time is somewhat lower than atmospheric pressure, either atmospheric pressure or pressurized pressure. It may be in a state. However, in order to prevent oxygen from being mixed in the atmosphere, the pressure is preferably set to atmospheric pressure or higher.

The heating time (maintenance time at the maximum temperature) during the main firing may be a time required for the reaction between the phosphor raw material and nitrogen, but is usually 1 minute or more, preferably 10 minutes or more, more preferably 30 minutes or more, More preferably, it is 60 minutes or more. If the heating time is shorter than 1 minute, the nitriding reaction may not be completed and a phosphor having high characteristics may not be obtained. The upper limit of the heating time is determined from the viewpoint of production efficiency, and is usually 50 hours or less, preferably 40 hours or less, more preferably 30 hours.
Below time.

In the main firing, the firing container filled with the phosphor raw material mixture is placed in a heating furnace. The firing apparatus used here is optional as long as the effects of the present invention can be obtained, but an apparatus capable of controlling the atmosphere in the apparatus is preferable, and an apparatus capable of controlling the pressure is also preferable. For example, a hot isostatic press (HIP), a resistance heating vacuum pressurizing atmosphere heat treatment furnace, and the like are preferable.

Further, it is preferable to circulate a gas containing nitrogen in the baking apparatus and sufficiently replace the inside of the system with this nitrogen-containing gas before the start of heating. If necessary, a nitrogen-containing gas may be circulated after the system is evacuated.
Examples of the nitrogen-containing gas used in the firing include a gas containing a nitrogen element, such as nitrogen, ammonia, or a mixed gas of nitrogen and hydrogen. Moreover, only 1 type may be used for nitrogen-containing gas and it may use 2 or more types together by arbitrary combinations and a ratio.

[Post-processing process]
In the manufacturing method in this invention, you may perform another process as needed other than the process mentioned above. For example, after the above baking process, a pulverization process, a cleaning process, a classification process, a surface treatment process, a drying process, and the like may be performed as necessary.

(Crushing process)
For the pulverization step, for example, a pulverizer such as a hammer mill, roll mill, ball mill, jet mill, ribbon blender, V-type blender or Henschel mixer, or pulverization using a mortar and pestle can be used.

(Washing process)
The washing step is not particularly limited as long as the effects of the present invention are not impaired. For example, the phosphor surface can be formed with water such as deionized water, an organic solvent such as ethanol, or an alkaline aqueous solution such as ammonia water.
For example, hydrochloric acid, nitric acid, sulfuric acid, aqua regia and hydrofluoric acid and sulfuric acid are used for the purpose of improving the luminous characteristics by removing the impurity phase adhering to the phosphor surface, such as removing the used flux. An acidic aqueous solution containing an inorganic acid such as a mixture thereof; an organic acid such as acetic acid can also be used.

(Classification process)
A classification process can be performed by using various classifiers, such as a water sieve, various airflow classifiers, or a vibration sieve, for example. In particular, when dry classification using a nylon mesh is used, a phosphor having a volume average diameter of about 10 μm and excellent dispersibility can be obtained. When dry classification using nylon mesh and water tank treatment are used in combination, the volume median diameter is 20 μm.
A phosphor having good dispersibility of about m can be obtained.

(Drying process)
The phosphor after the washing is dried at about 100 ° C. to 200 ° C. You may perform the dispersion | distribution process (for example, mesh pass etc.) of the grade which prevents dry aggregation as needed.

(Surface treatment process)
When manufacturing a light-emitting device using the phosphor of the present invention, in order to further improve the weather resistance such as moisture resistance, or to improve the dispersibility of the phosphor in the phosphor-containing portion of the light-emitting device to be described later If necessary, surface treatment such as partially covering the surface of the phosphor with a different substance may be performed.

{Fluoride inorganic binder}
[Fluoride inorganic binder and fluoride inorganic binder particles]
In the sintered phosphor according to the embodiment of the present invention, as a method for confirming the presence of the fluoride inorganic binder, the identification of the inorganic binder phase by X-ray diffraction, the surface of the sintered body or the cross-sectional structure by an electron microscope Observation and elemental analysis, and elemental analysis by fluorescent X-rays.

The total volume fraction of the nitride phosphor and the fluoride inorganic binder with respect to the total volume of the sintered phosphor is
Preferably it is 80% or more, more preferably 90% or more, particularly preferably 95%.
% Or more. This is because if the total volume fraction is low, the effects of the present invention cannot be exhibited. However, if the components other than the nitride phosphor and the fluoride inorganic binder are components added for the purpose of improving thermal conductivity and adjusting the refractive index, the total volume fraction may be lower than the preferred range. Permissible.
The volume fraction of the fluoride inorganic binder with respect to the total volume of the nitride phosphor and the fluoride inorganic binder is usually 50% or more, preferably 60% or more, more preferably 70% or more, and usually 99% by volume or less. Preferably it is 98% or less, More preferably, it is 97% or less.

In the present embodiment, the fluoride inorganic binder is used as a matrix for dispersing the nitride phosphor, and is preferably a crystalline matrix. The matrix may contain other than the fluoride inorganic binder, but is preferably a crystalline compound. The fluoride inorganic binder is preferably one that transmits a part of the excitation light emitted from the light emitting element or at least a part of the light emitted from the nitride phosphor. In order to efficiently extract light emitted from the nitride phosphor, it is preferable that the refractive index of the fluoride inorganic binder is close to the refractive index of the phosphor. Furthermore, it is preferable to withstand heat generation caused by irradiation with strong excitation light and to have a heat dissipation property. Moreover, the moldability of a sintered fluorescent substance becomes favorable by using a fluoride inorganic binder.

Specific examples of the fluoride inorganic binder include CaF ₂ (calcium fluoride), MgF
₂ (magnesium _fluoride), BaF ₂ (barium fluoride), SrF ₂ (strontium fluoride), LaF ₃ (lanthanum fluoride), YF ₃ (yttrium fluoride) AlF ₃ (aluminum fluoride) alkaline earth metals such as Any one or more selected from the group consisting of metals, rare earth metal fluorides and typical metals, and composites thereof are used as the main component. Here, the main component means that 50% by weight or more is occupied as the fluoride inorganic binder to be used.
Among these, CaF ₂ is preferably used as the fluoride inorganic binder from the viewpoint of cost and ease of sintering. Alternatively, it is preferable to use a composite containing 50% by weight or more of CaF ₂ as the fluoride inorganic binder, more preferably a composite containing 80% by weight or more, and a composite containing 90% by weight or more. It is particularly preferred. Further, the fluoride inorganic binder may contain a halide, oxide or nitride other than these in an amount of 5% or less.
The fluoride inorganic binder is configured by physically and / or chemically combining particles having the same composition as the fluoride inorganic binder.

(Physical properties of fluoride inorganic binder particles)
-Particle size The fluoride inorganic binder particles have a volume median diameter of usually 0.01 μm or more, preferably 0.02 μm or more, more preferably 0.03 μm or more, and particularly preferably 0.05 μm.
In addition, it is usually 15 μm or less, preferably 10 μm or less, more preferably 5 μm.
Hereinafter, it is more preferably 3 μm or less, particularly preferably 2 μm or less. When the fluoride inorganic binder particles are in the above range, the sintering temperature can be reduced, and the deactivation of the nitride phosphor due to the reaction between the nitride phosphor and the inorganic binder can be suppressed, A decrease in internal quantum efficiency of the sintered phosphor can be suppressed.
The volume median diameter can be measured by, for example, the above-mentioned Coulter counter method, and other representative apparatuses include laser diffraction particle size distribution measurement, scanning electron microscope (SEM), transmission electron microscope (TEM), precision particle size. Measurement is performed using a distribution measuring device Multisizer (manufactured by Beckman Coulter).

-Purity Examples of methods for confirming the purity of the fluoride inorganic binder particles include inductively coupled plasma emission spectroscopic analysis (ICP-AES analysis) and elemental quantitative analysis using fluorescent X-rays.
The purity of the fluoride inorganic binder particles is usually 99% or higher, preferably 99.5% or higher, more preferably 99.9% or higher. Within the above range, it is difficult for foreign matter to occur after sintering,
This is preferable because the sintered body has good properties such as transparency and luminous efficiency.

-Refractive index As a method for confirming the refractive index of the fluoride inorganic binder particles, a sintered body made of fluoride inorganic binder particles is mirror-polished and used to obtain the minimum deflection angle method, critical angle method, V block The method of measuring by a method is mentioned.
The refractive index nb of the fluoride inorganic binder particles is the ratio of the refractive index np of the nitride phosphor nb /
np is 1 or less, preferably 0.8 or less, more preferably 0.6 or less. If the refractive index ratio is greater than 1, the light extraction efficiency after sintering tends to be reduced. For this reason, the said range is preferable.

・ Thermal conductivity As a method for confirming the thermal conductivity of fluoride inorganic binder particles, a sintered body made of fluoride inorganic binder particles is prepared, and a steady heating method, a laser flash method,
The method of measuring by a periodic heating method is mentioned.
The thermal conductivity of the fluoride inorganic binder particles is usually 3.0 W / (m · K) or more, preferably 5.0 W / (m · K) or more, more preferably 10 W / (m · K) or more. is there. When the thermal conductivity is less than 3.0 W / (m · K), the temperature of the sintered phosphor may increase due to irradiation with strong excitation light, and the phosphor and peripheral members tend to be deteriorated. For this reason, the said range is preferable.

Particles of components other than the phosphor can be added to the fluoride inorganic binder for the purpose of adjusting the refractive index and improving the thermal conductivity. As the particles for the above purpose, particles having low light absorption and excellent thermal conductivity are preferable, and boron nitride, silicon nitride, aluminum nitride, alumina, and magnesia are preferable. From the viewpoint of heat dissipation, boron nitride is preferable, and from the viewpoint of low light absorption, alumina, magnesia, and silicon oxide are preferable. The volume fraction of the particles in the sintered phosphor is preferably 50% or less, and 30% or less. Further preferred. If the amount is too large, the sintered phosphor may not have a mechanical strength necessary for practical use. The particle size of the particles is preferably 10 microns or less, more preferably 5 microns or less, 2
Particularly preferred is micron or less. The smaller the particle size, the easier it is to disperse uniformly in the fluoride inorganic binder, and it becomes easier to obtain a homogeneous sintered phosphor.

-Melting point The fluoride inorganic binder particles preferably have a low melting point. By using fluoride inorganic binder particles having a low melting point, it becomes possible to reduce the sintering temperature, and can suppress the deactivation of the nitride phosphor due to the reaction between the nitride phosphor and the inorganic binder, A decrease in internal quantum efficiency of the sintered phosphor can be suppressed. Specifically, the melting point is preferably 1500 ° C. or lower, and more preferably 1300 ° C. or lower. The lower limit temperature is not particularly limited and is usually 500 ° C. or higher.

-Solubility Fluoride inorganic binder particles have a solubility of 0.05 per 100 g of water at 20 ° C.
g or less is preferable.

[Formula [1] Phosphor other than phosphor]
The sintered phosphor of the present embodiment may contain other phosphors other than the formula [1] phosphor as long as the effects of the present invention are not impaired. Other phosphors may be (oxy) nitride phosphors, oxide phosphors, or both of them.
Specific examples of other phosphors are shown below, but the present invention is not limited thereto.

((Acid) nitride phosphor)
Examples of the (acid) nitride phosphor that may be included in the sintered phosphor of the present embodiment include the following.
Nitride phosphors containing strontium and silicon in the crystalline phase (specifically, SCASN, S
r ₂ Si ₅ N ₈ ), calcium and silicon in the crystal phase (specifically, S
CASN, CASN, CASON), nitride phosphor containing strontium, silicon, and aluminum in crystal phase (specifically, SCASN, Sr ₂ Si ₅ N ₈ ), nitride containing calcium, silicon, and aluminum in crystal phase Phosphor (specifically, SCASN, CAS
N, CASON).

More specifically, for example, β sialon that can be represented by the following general formula: Si _{6−
z Al z O z N 8-} z: Eu ( wherein 0 <z <4.2), α-sialon,
LSN represented by the following general formula: Ln _x Si _y N _n : Z (wherein Ln is a rare earth element excluding an element used as an activating element. Z is an activating element. 2.7 ≦ x ≦ 3.3, 5.4 ≦
It satisfies y ≦ 6.6 and 10 ≦ n ≦ 12. )

CASN: CaAlSiN ₃ : Eu represented by the following general formula:
SCASN that can be represented by the following general formula: (Ca, Sr, Ba, Mg) AlSiN ₃
: Eu and / or (Ca, Sr, Ba) AlSi (N, O) ₃ : Eu),
CASON that can be represented by the following general formula: (CaAlSiN ₃ ) _1-x (Si ₂ N ₂
O) _x : Eu (where 0 <x <0.5),
CaAlSi ₄ N ₇ : (Sr, Ca, Ba) _1-y Al that can be represented by the following general formula
_{1 + x} Si _4−x O _x N _7−x : Eu _y (where 0 ≦ x <4, 0 ≦ y <0.2),
Sr ₂ Si ₅ N ₈ : (Sr, Ca, Ba) ₂ Al _x Si that can be represented by the following general formula
Examples include phosphors such as _5-x O _x N _8-x : Eu (where 0 ≦ x ≦ 2).

Among these phosphors, from the viewpoint of good brightness when made a sintered phosphor,
Nitride phosphors that do not contain oxygen as a constituent element (including inevitably mixed oxygen), that is,
It is preferable to use nitride phosphors such as LSN, CASN, SCASN, Sr ₂ Si ₅ N ₈ , and β sialon.

In particular, a sintered phosphor containing both the LSN phosphor and the formula [1] phosphor is preferable because it can produce a light emitting device having an excellent balance between luminous efficiency and color rendering. In this case, the LSN phosphor preferably has all Ln in the above formula as La.
As described above, the sintered phosphor containing two kinds of phosphors is preferable in terms of easy production because the influence of the phosphor lot-to-lot variation can be adjusted by the blending ratio of the two kinds of phosphors during mass production.
The correlated color temperature of the light emitting device manufactured with this configuration is preferably 5000 K or higher, and more preferably 6000 K or higher. Illumination with a high correlated color temperature is bright because it contains a relatively large amount of light with high visibility.

Moreover, the sintered phosphor containing both the CASN phosphor or the SCASN phosphor and the formula [1] phosphor can be suitably used for a light emitting device that emits light at a low color temperature, and has an excellent balance between luminous efficiency and color rendering. It is preferable because a light emitting device can be manufactured.

(Oxide phosphor)
Examples of the oxide phosphor that may be included in the sintered phosphor of the present embodiment include the following.
An oxide phosphor having a garnet structure such as Y ₃ Al ₅ O ₁₂ : Ce, Lu ₃ Al ₅ O ₁₂ : Ce can be used. In addition, those in which these constituent elements are partially substituted are also included. As a replacement method, Y can be replaced with Gd, Tb, and Lu, Al can be replaced with Ga, and Lu can be replaced with Gd, Tb, and Y. Alternatively, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce
A silicate phosphor such as Mg, Lu ₂ CaMg ₂ Si ₃ O ₁₂ : Ce can be used. S
Aluminate phosphors such as rAl ₂ O ₄ : Eu and Sr ₄ Al ₁₄ O ₂₅ : Eu can also be used.

The particle size and volume fraction in the above (oxy) nitride phosphor and oxide phosphor are expressed by the equation [1
It is the same as that described in the section of phosphor. The preferred embodiment is also the same.
In _{particular, Y 3 Al 5 O 12:} Y 3 Al 5 O 12 was partially substituted with Ga with Ce or Al: C
A sintered phosphor containing both e and the phosphor of formula [1] is preferable because it can produce a light-emitting device having an excellent balance between luminous efficiency and color rendering. The correlated color temperature of the light emitting device manufactured with this configuration is preferably 5000 K or higher, and more preferably 6000 K or higher.

[Method for producing sintered phosphor]
By using the above-mentioned nitride phosphor and fluoride inorganic binder particles, or garnet phosphor, nitride phosphor, and fluoride inorganic binder particles as main raw materials, and compacting and sintering these mixtures, A sintered phosphor that is a composite can be produced, but there is no particular limitation on the production method. A more preferable production method is described below.

[Method for producing sintered phosphor]
By using the above-mentioned nitride phosphor and fluoride inorganic binder particles, or garnet phosphor, nitride phosphor, and fluoride inorganic binder particles as main raw materials, and compacting and sintering these mixtures, A sintered phosphor that is a composite can be produced, but there is no particular limitation on the production method. A more preferable production method is described below.

Specifically, the following (Step 1) to (Step 2) are exemplified.
(Step 1) Step of stirring and mixing nitride phosphor (or garnet-based phosphor and nitride phosphor) and inorganic binder particles, press-pressing, and sintering the molded body (Step 2) nitride fluorescence The body (or garnet phosphor and nitride phosphor) and inorganic binder particles are agitated and mixed and sintered simultaneously with the pressure press

(Process 1)
Stirring / mixing step First, a nitride phosphor (or garnet phosphor and nitride phosphor) and inorganic binder particles are mixed to obtain a mixed powder of the nitride phosphor and the like and inorganic binder particles. When the entire sintered body composed of the nitride phosphor and the inorganic binder particles is taken as 100%, the volume fraction of the fluoride inorganic binder is usually 50% or more, preferably 60% or more, more preferably 70% or more. Yes, usually 99% or less, preferably 98% or less, more preferably 97% or less. A method of stirring and mixing these is, for example, a dry mixing method such as a ball mill or a V blender, or a slurry is added to a nitride phosphor or an inorganic binder to form a slurry, and a ball mill, homogenizer, ultrasonic homogenizer, biaxial Examples thereof include a wet mixing method using a kneader and the like. The stirring / mixing time is usually 0.5 hours or longer, preferably 2 hours or longer, more preferably 6 hours or longer, and usually 72 hours or shorter, preferably 48 hours or shorter, more preferably 24 hours or shorter. Thus, the whole can be mixed uniformly by mechanically stirring and mixing.

Here, an organic binder, a dispersant, and a solvent may be added in order to improve the moldability by a pressure press. When adding an organic binder or the like, for example, when the entire sintered body is 100 wt%, the organic binder is usually 0.1 wt% or more and 5 wt% or less, and the dispersant is usually 0.01 wt% or more and 3 wt% or less. The solvent is usually mixed in an amount of 10 wt% to 70 wt% to prepare a slurry. In this case, polyvinyl alcohol, polyacrylic acid, polyvinyl butyral, methylcellulose, starch or the like can be used as the organic binder. As the dispersant, stearic acid, sodium dodecylbenzenesulfonate, ammonium polycarboxylate, or the like can be used. As the solvent, water, methyl alcohol, ethyl alcohol, isopropyl alcohol, or the like can be used. These may be used alone or in combination.

Examples of a method for mixing these include a ball mill, a homogenizer, an ultrasonic homogenizer, a wet mixing method using a twin-screw kneader, and the like. When an organic binder or the like is added, the stirring / mixing time is usually 0.5 hours or longer, preferably 2 hours or longer, more preferably 6 hours or longer, usually 72 hours or shorter, preferably 48 hours or shorter, more preferably 24 hours. Below time. Thus, the whole can be mixed uniformly by mechanically stirring and mixing. Moreover, you may mix with fluorescent substance using the inorganic binder particle | grains coat | covered with the organic binder.

In the case of wet mixing, the solvent drying / granulation step is performed after the stirring / mixing step. In the solvent drying / granulating step, the slurry obtained by the stirring / mixing step is volatilized at a predetermined temperature to obtain a mixed powder of nitride phosphor, inorganic binder particles, and organic binder. Or you may produce the granulated particle which has a predetermined particle size by using a well-known spray-drying apparatus (spray dryer apparatus). The average particle size of the granulated particles is usually 22 μm or more, preferably 2
4 μm or more, more preferably 26 μm or more, usually 200 μm or less, preferably 15
It is 0 μm or less, more preferably 100 μm or less. If the granulated particle size is small, the bulk density becomes small, powder handling properties, filling the press mold becomes difficult, and if the granulated particle size is large, pores remain in the molded body after pressing, This leads to a decrease in the degree of sintering.

-Molding process Here, the mixed powder obtained in the stirring / mixing process is press-molded using uniaxial mold molding and cold isostatic pressing (CIP) to obtain a green body having a desired shape. The pressure during molding is usually 1MP
a or more, preferably 5 MPa or more, more preferably 10 MPa or more, and usually 1000
MPa or less. If the pressure at the time of molding is too low, a molded body cannot be obtained, and if the pressure is too high, the phosphor may be mechanically damaged and the light emission characteristics may be reduced.

-Degreasing process If necessary, degreasing is performed by burning out the organic binder components in the air from the green body formed using the organic binder. The furnace used for degreasing is not particularly limited as long as a desired temperature and pressure can be realized. There are no particular restrictions as long as the above requirements are met. A high pressure induction heating furnace, a direct resistance heating, an indirect resistance heating, a direct combustion heating, a radiant heat heating, an electric heating, etc. can also be used as an interhydrostatic sintering apparatus, a pressurized atmosphere furnace, and a heating method. During the treatment, stirring may be performed as necessary.

The atmosphere for the degreasing treatment is not particularly limited, but it is preferably carried out in the air or under atmospheric flow. The degreasing temperature varies depending on the inorganic binder used, but is usually 300 ° C. or higher, preferably 400 ° C. or higher, more preferably 50 ° C.
0 ° C. or higher, usually 1200 ° C. or lower, preferably 1100 ° C. or lower, more preferably 10
It is below 00 ° C.

The degreasing time is usually 0.5 hours or longer, preferably 1 hour or longer, more preferably 2 hours or longer, and usually 6 hours or shorter, preferably 5 hours or shorter, more preferably 4 hours or shorter. If the processing temperature and time are less than this range, organic components cannot be removed sufficiently,
If it is larger than this range, the surface of the phosphor, such as oxidized, is altered and tends to cause a reduction in light emission characteristics.

In the degreasing step, the heat history temperature condition, the heating rate, the cooling rate, the heat treatment time, etc. can be set as appropriate. Further, after heat treatment in a relatively low temperature region, the temperature can be raised to a predetermined temperature. In addition, the reactor used for this process may be a batch type or a continuous type, and may be one or more.

-Sintering process A sintered fluorescent substance is obtained by sintering the molded object obtained through the formation process and / or the degreasing process. The process used for sintering is not particularly limited as long as the desired temperature and pressure can be realized. For example, reactors such as shuttle furnaces, tunnel furnaces, lead hammer furnaces, rotary kilns, autoclaves, tamman furnaces, atchison furnaces, hot press equipment, pulsed energization pressure sintering equipment, hot isostatic pressing equipment, pressurized atmosphere furnaces As the heating method, a high-frequency induction heating furnace, direct resistance heating, indirect resistance heating, direct combustion heating, radiant heat heating, current heating, or the like can be used. During the treatment, stirring may be performed as necessary. The atmosphere of the sintering treatment is not particularly limited, but it is an air atmosphere, an N ₂ atmosphere, an Ar atmosphere, a vacuum, or an air flow.
It is preferable to carry out under N ₂ flow, Ar flow, atmospheric pressure, N ₂ pressure, and Ar pressure. In particular, when the temperature is raised, degassing derived from the raw material can be promoted by heating under vacuum, which is effective in obtaining a sintered body with few voids. Further, H ₂ may be appropriately introduced into the atmospheric gas. Although the optimum temperature range varies depending on the inorganic binder used, the sintering treatment temperature is usually 300 ° C. or higher, preferably 400 ° C. or higher, more preferably 500 ° C. or higher, and usually 1900 ° C. or lower, preferably 1500 ° C. or lower. Preferably it is 1300 degrees C or less. The sintering temperature is usually 50 ° C. or lower, preferably 100 ° C. or lower, more preferably 150 ° C. or lower, based on the melting point of the fluoride inorganic binder used. here,
The melting point of calcium fluoride (CaF ₂ ) is 1418 ° C., strontium fluoride (SrF ₂ )
The melting point of is 1477 ° C. You may implement the atmosphere of sintering processing under pressure. It is also possible to perform the degassing step after the molding step and before the sintering at a temperature lower than the sintering temperature.

The heating rate during firing is usually 10 ° C./min, preferably 2.5 ° C., more preferably 1 ° C./min.
Minutes. If the temperature rise time is early, the sintering proceeds before the gas from the raw material escapes, which may cause a decrease in the degree of sintering. Instead of controlling the rate of temperature rise, it is also effective to raise the temperature after holding at a temperature lower than the firing top temperature, or to perform preliminary firing at a temperature lower than the firing top temperature as a degassing treatment step.

The sintering time is usually 0.1 hours or longer, preferably 0.5 hours or longer, more preferably 1
It is not less than 6 hours, usually not more than 6 hours, preferably not more than 5 hours, more preferably not more than 4 hours. If the treatment temperature and time are smaller than this range, the organic components cannot be sufficiently removed. If the treatment temperature and time are larger than this range, the surface of the phosphor, such as oxidized, is denatured, leading to deterioration of the light emission characteristics.

In the sintering step, the heat history temperature condition, the temperature raising rate, the cooling rate, the heat treatment time, etc. are appropriately set. Further, after heat treatment in a relatively low temperature region, the temperature can be raised to a predetermined temperature. In addition, the reactor used for this process may be a batch type or a continuous type, and may be one or more.
The molded body once obtained in the sintering step can be further sintered. The process used for sintering is not particularly limited, and includes a hot isostatic pressing apparatus.
In the sintering process, a sintering aid can be appropriately used. It is not particularly limited as sintering aids for use in the sintering _{process, MgO, Y 2 O 3,} CaO, Li 2 O, BaO, La 2
O ₃ , Sm ₂ O ₃ , Sc ₂ O ₃ , ZrO ₂ , SiO ₂ , MgAl ₂ O ₄ , LiF, NaF
, BN, AlN, Si ₃ N ₄ , Mg, Zn, Ni, W, ZrB ₂ , Ti, Mn, and the like, and two or more of these may be used in combination.

(Process 2)
-Stirring / mixing step The stirring / mixing step can be carried out in the same manner as the stirring / mixing step of step 1.

-Pressure press sintering process A sintered fluorescent substance is obtained by heating the mixed powder of the nitride fluorescent substance etc. which were obtained by the stirring and mixing process, and inorganic binder particle | grains, pressurizing. The furnace used for pressure press sintering is not particularly limited as long as the desired temperature and pressure can be achieved. For example, a hot press device, a pulsed current pressure sintering device, a hot isostatic pressing device, a heating method, a high frequency induction heating furnace, direct resistance heating,
Indirect resistance heating, direct combustion heating, radiant heat heating, current heating, and the like can be used. The atmosphere of the pressure press sintering treatment is not particularly limited, but it is an air atmosphere, an N ₂ atmosphere, an Ar atmosphere, a vacuum, an air flow, an N ₂ flow, an Ar flow, an air It is preferably carried out under pressure, N ₂ pressure, and Ar pressure. Further, H ₂ may be appropriately introduced into the atmospheric gas. Although the optimum temperature range varies depending on the inorganic binder used, the sintering treatment temperature is usually 300 ° C. or higher, preferably 400 ° C. or higher, more preferably 500 ° C. or higher, and usually 1900 ° C. or lower, preferably 1500 ° C. or lower. Preferably 1300 ° C
Hereinafter, it is more preferably 1000 ° C. or lower. Moreover, the sintering temperature should just be 50 degreeC or more lower than melting | fusing point of the fluoride inorganic binder to be used, Preferably it is 100 degreeC or more lower temperature, More preferably, it is 150 degreeC or more lower temperature. Here, calcium fluoride (CaF ₂
) Has a melting point of 1418 ° C., and strontium fluoride (SrF ₂ ) has a melting point of 1477 ° C.

The sintering time is usually 0.1 hours or longer, preferably 0.5 hours or longer, more preferably 1
It is not less than 6 hours, usually not more than 6 hours, preferably not more than 5 hours, more preferably not more than 4 hours.
The pressing pressure is usually 1 MPa or more, preferably 5 MPa or more, more preferably 10 MPa.
It is not less than MPa, usually 1000 MPa, preferably not more than 800 MPa, more preferably not more than 600 MPa. If the pressure at the time of molding is too low, a molded body cannot be obtained, and if the pressure is too high, the phosphor may be mechanically damaged and the light emission characteristics may be reduced.

In the pressure press sintering process, the heat history temperature condition, the temperature rise rate, the cooling rate, the heat treatment time, etc. are appropriately set. Further, after heat treatment in a relatively low temperature region, the temperature can be raised to a predetermined temperature. In addition, the reactor used for this process may be a batch type or a continuous type, and may be one or more.
In the sintering process, a sintering aid can be appropriately used. There is no particular restriction on the sintering aid used in the sintering _{step, MgO, Y 2 O 3,} CaO, Li 2 O, BaO, La
₂ O ₃ , Sm ₂ O ₃ , Sc ₂ O ₃ , ZrO ₂ , SiO ₂ , MgAl ₂ O ₄ , LiF, Na
F, BN, AlN, Si ₃ N ₄ , Mg, Zn, Ni, W, ZrB ₂ , H ₂ , Ti, Mn,
These may be used, and two or more of these may be used in combination.

The obtained sintered phosphor may be used as it is, but it is usually sliced at a predetermined thickness, and further processed to a predetermined thickness plate shape by grinding and polishing to obtain a plate-like sintered phosphor. . Grinding / polishing conditions are not particularly limited. For example, with a # 800 diamond grindstone, polishing is performed at a grindstone rotation speed of 80 rpm, a workpiece rotation speed of 80 rpm, and 50 g / cm ² and processed into a plate shape. The lower limit of the final thickness of the sintered phosphor is usually 30 μm or more, preferably 50 μm or more, more preferably 100 μm or more, and the upper limit is usually 20 μm.
It is 00 μm or less, preferably 1000 μm or less, more preferably 800 μm or less, more preferably 500 μm or less. If the thickness of the sintered phosphor plate is less than this range, the sintered phosphor plate is easily damaged.
Further, after the surface is appropriately polished, the unevenness may be appropriately formed by wet etching treatment, dry wet etching treatment or the like.

{Physical properties of sintered phosphor}
[Characteristics of sintered phosphor]
The sintered phosphor of the present embodiment preferably further has the following characteristics.
-Sintering degree As a method for confirming the sintering degree of the sintered phosphor of the present embodiment, the density ρ _a by the Archimedes method is measured, and the theoretical density ρ _{theoretical of the} sintered body is used, and ρ _a / ρ _t
Calculated by “ _heoretic × 100”.

Here, the theoretical density is a density when atoms in the material are ideally arranged.
The degree of sintering of the sintered phosphor is usually 90% or more, preferably 95% or more, more preferably 99%.
% Or more. If the degree of sintering is within this range, the number of pores (voids) existing inside the sintered phosphor is reduced, and the light transmittance and light extraction efficiency (conversion efficiency) are improved. On the other hand, if the degree of sintering is below this range, light scattering is strong and the light extraction efficiency decreases. For this reason, the said range is preferable.
The degree of sintering of the sintered phosphor can be adjusted to the above range by adjusting the sintering temperature and the sintering time.

Absorptivity As a method for confirming the absorptivity of the sintered phosphor of the present embodiment, an absorptiometer (UV-
Vis), and the measurement method is mentioned.
The absorptivity with respect to visible light of 500 nm or more of the sintered phosphor is usually 10% or less, preferably 5.0% or less, more preferably 3.5% or less, and further preferably 1.5% or less. When the absorptance is larger than 10%, the light emission efficiency (internal quantum efficiency) and the transmittance tend to be lowered, and thereby the light extraction efficiency (conversion efficiency) tends to be lowered. For this reason, the said range is preferable.
On the other hand, the absorptance with respect to light of 500 nm or less is preferably higher, preferably 40% or more, more preferably 50% or more, and particularly preferably 60% or more. When the absorption rate for light of 500 nm or less is high, light generated by the LED or laser of the light emitting device can be efficiently absorbed, and the amount of fluorescent light can be increased.

-Transmittance As a method for confirming the transmittance of the sintered phosphor of the present embodiment, there is a method of measuring with an integrating sphere and a spectroscope.
The transmittance of the sintered phosphor is measured at a wavelength of 700 nm, and is usually 20% or more, preferably 25% or more, more preferably 30% or more, and further preferably 40% or more. If the transmittance is less than 20%, the amount of excitation light that passes through the sintered phosphor decreases, making it difficult to achieve the desired chromaticity and decreasing the light extraction efficiency (conversion efficiency).

Correlated color temperature CCT, chromaticity coordinates CIE-x, y
The correlated color temperature of the sintered phosphor of this embodiment has a peak wavelength of 450 nm emitted from the LED.
It calculates from the luminescent color including the transmitted light of the blue light obtained by irradiating blue light.
The correlated color temperature of a sintered phosphor used in a general lighting device or the like is usually 1900K or more and 5000K or less when excited with blue light having a wavelength of 450 nm, and 2700K, 3000K, 4
Since lighting devices of 000K and 5000K are generally used, it is preferable to adjust to these color temperatures. An illuminating device having a low correlated color temperature such as 1900K has recently been used as illumination simulating candle light, and it is also preferable to adjust to this correlated color temperature.

Internal quantum efficiency internal quantum efficiency of the sintered phosphor of the present embodiment (IQE) was converted photons sintered phosphor when irradiated with blue light having a peak wavelength of 450nm has absorbed a photon number n _ex absorbed It is calculated as n _em / n _ex from the number of photons n _em of the converted light. In order to obtain a high-intensity light emitting device in which the internal quantum efficiency of light emitted when excited with blue light having a wavelength of 450 nm is usually 40% or more, the higher the internal quantum efficiency of the sintered phosphor, the more preferable, Preferably it is 60% or more, more preferably 65% or more, still more preferably 70% or more, still more preferably 75% or more, and particularly preferably 80% or more. If the internal quantum efficiency is low, the light extraction efficiency (conversion efficiency) tends to decrease.

{Light emitting device}
Another embodiment of the present invention is a light emitting device including a sintered phosphor and a semiconductor light emitting element.
The light emitting device of the present invention contains at least a blue semiconductor light emitting element (blue light emitting diode or blue semiconductor laser) and a sintered phosphor according to an embodiment of the present invention which is a wavelength conversion member that converts the wavelength of blue light. To do. The blue semiconductor light emitting element and the sintered phosphor may be in close contact with each other or may be separated from each other, and a transparent resin may be provided therebetween, or a space may be provided. As shown schematically in FIG. 1, a structure having a space between the semiconductor light emitting element and the sintered phosphor is preferable.

Further, in order to efficiently introduce the light of the blue semiconductor light emitting element into the sintered phosphor of the present embodiment,
An embodiment in which the blue semiconductor light emitting element and the sintered phosphor are in close contact is also a preferred embodiment.
In this case, the sintered phosphor and the blue semiconductor light emitting element are preferably bonded with an adhesive having high heat resistance and high heat conductivity in order to promote mutual heat conduction. As the adhesive having high heat resistance, a silicone resin adhesive is preferable. As the silicone resin adhesive, an adhesive containing a filler (fine particles) for improving the thermal conductivity is preferable. In order to increase the mutual heat conduction between the sintered phosphor and the blue semiconductor light emitting device, it is preferable to make the adhesive as thin as possible.
It is preferable to set it to micron or less, and it is more preferable to set it to 2 micron or less. A configuration in which the sintered phosphor and the blue semiconductor light emitting element are brought into close contact with each other by another structural device without using an adhesive is preferable from the viewpoint that the heat resistant temperature of the entire light emitting element can be increased. The reason is that when a silicone resin adhesive is used, it cannot be used beyond the heat resistance temperature of a silicone resin adhesive, which is generally said to be about 200 ° C., or even if it can be used, the durability is inferior. This is because it becomes.

Hereinafter, the configuration will be described with reference to FIGS.
FIG. 2 is a schematic view of a light emitting device according to a specific embodiment of the present invention.
The light emitting device 10 includes at least the blue semiconductor light emitting element 1 and the sintered phosphor 3 as its constituent members. The blue semiconductor light emitting element 1 emits excitation light for exciting the phosphor contained in the sintered phosphor 3.

The blue semiconductor light-emitting element 1 usually emits excitation light having a peak wavelength of 425 nm to 475 nm,
Preferably, excitation light having a peak wavelength of 430 nm to 470 nm is emitted. The number of blue semiconductor light emitting elements 1 can be appropriately set depending on the intensity of excitation light required by the apparatus.
On the other hand, a purple semiconductor light emitting element can be used instead of the blue semiconductor light emitting element 1. The violet semiconductor light emitting device usually emits excitation light having a peak wavelength of 390 nm to 425 nm, and preferably emits excitation light having a peak wavelength of 395 to 415 nm.
As the blue or violet semiconductor light emitting device, an indium gallium nitride light emitting diode (LED) or an indium gallium nitride semiconductor laser is preferable.

The light output (radiant flux) of the blue or violet semiconductor light emitting device is 1 mm ² of light emitting area of the light emitting device.
1.0 W or more is preferable, 2.0 W or more is more preferable, and 3.0 W or more is particularly preferable. Thus, by combining the high-power semiconductor light-emitting element and the sintered phosphor of the present invention, a light-emitting element and a lighting device with a large amount of light can be configured. When a color conversion member in which a phosphor is mixed with a commonly used silicone resin is used, the heat resistance and durability of the silicone resin are not sufficient, and thus such a high output semiconductor light emitting device is used. I can't.

The blue semiconductor light emitting element 1 is mounted on the chip mounting surface 2 a of the wiring board 2. A wiring pattern (not shown) for supplying electrodes to these blue semiconductor light emitting elements 1 is formed on the wiring substrate 2 to constitute an electric circuit. In FIG. 2, it is displayed that the sintered phosphor 3 is placed on the wiring substrate 2, but this is not a limitation, and the wiring substrate 2 and the sintered phosphor 3 may be arranged via other members. Good.

For example, in FIG. 1, the wiring board 2 and the sintered phosphor 3 are arranged via the frame body 4. The frame body 4 may have a tapered shape in order to give light directivity. The frame 4 may be a reflective material.
From the viewpoint of improving the light emission efficiency of the light emitting device 10, the wiring board 2 is preferably excellent in electrical insulation, has good heat dissipation, and preferably has a high reflectance, but on the chip mounting surface of the wiring board 2. Thus, a reflective plate having a high reflectance can be provided on the surface where the blue semiconductor light emitting element 1 does not exist, or on at least a part of the inner surface of another member connecting the wiring substrate 2 and the sintered phosphor 3.

The sintered phosphor 3 converts the wavelength of a part of incident light emitted from the blue or purple semiconductor light emitting element 1 and emits outgoing light having a wavelength different from that of the incident light. The sintered phosphor 3 contains a fluoride inorganic binder and a nitride phosphor. The sintered phosphor further includes one or more of another nitride phosphor, a garnet phosphor emitting yellow or green, an oxide phosphor emitting blue or green, and a nitride phosphor emitting red. The type can be selected in consideration of the intended emission color, color rendering, spectral shape, and the like.

The light emitting device of the present invention is preferably a light emitting device that emits white light having a low color temperature.
In the light emitting device that emits white light, the light emitted from the light emitting device has a deviation d _uv (= D _UV / 1000) from the light-color black body radiation locus of −0.0200 to 0.0200, and The color temperature is preferably 1800K or more and 5000K or less.
Thus, the light-emitting device which radiate | emits white light is suitably provided in an illuminating device.

{Lighting device}
Another embodiment of the present invention is a lighting device including the light emitting device.
As described above, since a high total luminous flux is emitted from the light emitting device, a lighting fixture having a high total luminous flux can be obtained. The luminaire is preferably provided with a diffusing member that covers the sintered phosphor in the light emitting device so that the color of the sintered phosphor is not noticeable when the light is extinguished.

{Image display device}
Another embodiment of the present invention is an image display device including the light emitting device.
As described above, since light with a particularly high proportion of red light is emitted from the light emitting device of the present invention,
By using this light emitting device as a backlight, an image display device with excellent color balance can be obtained. In particular, in the case of a projector-type display that requires a large amount of light, it is difficult to emit red light with high efficiency. Therefore, by using the light emitting device using the sintered phosphor according to this embodiment, the efficiency of red light can be increased. An excellent projector-type display with a high value can be obtained.

{Vehicle indicator light}
Another embodiment of the present invention is a vehicle indicator lamp including the light emitting device. Since the sintered phosphor of the present embodiment emits light with a high proportion of red light, a tail lamp for a vehicle and a brake lamp (stop lamp) can be used by appropriately combining filters and mirrors. It can be suitably used for a direction indicator (turn lamp).

{Example}
EXAMPLES Next, specific embodiments of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
In the present specification, the degree of sintering, transmittance, optical characteristics, and lattice constant of the phosphor were measured as follows.

(Sintering degree)
The degree of sintering is the density ρ _a measured by the Archimedes method of the sintered phosphor, and the theoretical density ρ _{theore
Calculated} by dividing by _tical .
Sintering degree (%) = (ρ _a / ρ _theoretical ) × 100

[Luminescent properties of phosphor]
The phosphor powder sample was packed in a copper sample holder, and the emission spectrum was measured using MCPD7000 (manufactured by Otsuka Electronics Co., Ltd.). The emission intensity of each wavelength was measured with a spectrum measuring device in the wavelength range of 380 nm to 800 nm under the condition of excitation light of 455 nm, and an emission spectrum was obtained.
The chromaticity coordinate is a method according to JIS Z8724 from the data in the wavelength region of 480 nm to 780 nm of the emission spectrum obtained by the above method, and is defined by JIS Z8701.
The chromaticity coordinate values x and y in the YZ color system were calculated. The emission peak wavelength (hereinafter sometimes referred to as “peak wavelength”) and the half width of the emission peak were read from the obtained emission spectrum.

[Measurement of lattice constant of phosphor (powder X-ray diffraction measurement)]
Powder X-ray diffraction (XRD) is a powder X-ray diffractometer X'Pert PRO MPD (PAN
precision measurement). The measurement conditions are as follows.
CuKα tube used X-ray output = 45KV, 40mA
Scanning range 2θ = 10 ° ~ 150 °
Reading width = 0.008 °
Using the obtained diffraction pattern, lattice constants a and c were determined by pattern fitting. Note that pattern fitting is performed using a crystal structure of La ₃ Si ₆ N ₁₁ (space group P4
bm).

(optical properties)
A light emitting device capable of obtaining the light emission of the sintered phosphor by irradiating the blue light emitted from the LED chip (peak wavelength 454 nm) was produced. The emission spectrum emitted from the apparatus was converted into a 40 inch integrating sphere (manufactured by LabSphere) and a spectroscope MCPD9000 (
Otsuka Electronics Co., Ltd.) was used to measure color temperature chromaticity coordinates and luminous flux when pulse-excited with light having a radiant flux of 0.26 W. Further, the conversion efficiency (lm / W) was calculated for each intensity from the luminous flux (lumen) and the radiant flux (W) of the LED chip.

Next, using a xenon spectral light source as the light source, the excitation wavelength was set to 700 nm, and the transmittance of the sintered phosphor at the excitation wavelength of 700 nm was measured from the reflection and transmission spectra when irradiated to the sintered phosphor.
Subsequently, the internal quantum efficiency and the absorption rate at the excitation wavelength of 450 nm of the sintered phosphor were measured from the reflection and transmission spectra when the excitation wavelength was changed to 450 nm and irradiated onto the sintered phosphor.
Spectral light source manufactured by Spectra Corp., 20 inch integrating sphere LMS-200 (Lab
Sphere) and spectroscope Solid Lambda UV-Vis (Carl Zei)
The reflection and transmission spectra were observed by ss).

{Example 1}
[Manufacture of LYSN phosphor]
La: Si = 1: 1 (molar ratio) alloy, Si ₃ N ₄ , Y ₂ O ₃ , YF ₃ , CeF ₃ , YF ₃ : Y ₂ O ₃ = 1.00: 1.81 (molar ratio) And the charged element ratio is La: Y: C
e: Weighed so that Si = 2.90: 0.50: 0.66: 6.00 (molar ratio).
The weighed raw materials were put into an intensive mixer and mixed. These operations are oxygen concentration 1%
The following nitrogen atmosphere was used in the glove box.

The mixed raw material was filled in a Mo crucible and set in an electric furnace. After evacuating the inside of the apparatus, the furnace temperature was raised to 120 ° C., and after confirming that the furnace pressure was vacuum, the hydrogen-containing nitrogen gas (nitrogen: hydrogen = 96: 4 (volume ratio)) was increased. It was introduced until atmospheric pressure was reached. Then 15
The temperature in the furnace was raised to 50 ° C., held at 1550 ° C. for 8 hours, and then cooled to room temperature to obtain a fired product.
The fired product was pulverized with a ball mill, stirred in 1N hydrochloric acid for 1 hour or more, and then washed with water. Then, it dehydrated and dried with a 120 degreeC hot air dryer, and the LYSN fluorescent substance 1 was obtained. The median particle size of this phosphor was 30 μm.
The powder X-ray diffraction pattern of this phosphor is shown in FIG. The results of calculating the lattice constants a and c based on this data are shown in Table 1. The measurement results of the light emission characteristics are also shown in Table 1.

[Production of sintered phosphor]
As a fluoride inorganic binder material for sintered phosphor, CaF ₂ powder (Shirakaba Chemical Laboratory, 1μ
2.0 g of fine particles of m or less) and the above LYSN1 phosphor ((La, Y) ₃ Si ₆ N _1
1 : Ce) 0.27 g was weighed so that the phosphor concentration in the sintered body would be 8% by volume, and mixing with a mortar was performed. These powders were dry-mixed for 2 hours by rotation on a ball mill frame without balls and used as a raw material for sintering.

A uniaxial press die consisting of 2.0 g of this raw material consisting of an upper punch, a lower punch and a cylindrical die (
(Set to stainless steel, Φ20mm) After 10 tons of press pressure is applied and held for 5 minutes,
The pressure was released to obtain a pellet having a diameter of 20 mm and a thickness of 3 mm.
The obtained pellets are packed in a vacuum laminate and cold isostatic pressing (CIP) equipment (Nikkiso)
Rubber press) and pressurized at 300 MPa for 1 minute. After this, firing furnace (tubular furnace) (
Irie Works tubular furnace IRH), heated to 1200 ° C at 10 ° C / min, 60m
After holding in, the furnace was cooled to obtain a sintered body having a diameter of 18 mm and a thickness of 3 mm. The sintered density of this sintered body was measured by the above method.

(Grinding and evaluation)
The obtained sintered phosphor Φ18 mm, 3 mm thick sintered phosphor was cut to a thickness of about 0.5 mm with a diamond cutter, and further grinder grinding, Φ18 mm, thickness 0
. A 2 mm sintered phosphor was produced.
Using the sintered phosphor, transmittance at a wavelength of 700 nm, internal quantum efficiency, and absorption at 450 nm were measured. Further, a light emitting device was manufactured by the above method, and total luminous flux, conversion efficiency, chromaticity coordinates, correlated color temperature, and deviation D _UV (= d _uv × 1000) were measured. In addition, the color rendering index (Ra and R1 to R15) was examined.
The results obtained as described above are shown in Tables 2 to 4. Moreover, the emission spectrum by LED excitation was shown in FIG.

(Example 2)
In the manufacturing procedure of the LYSN phosphor of Example 1, the raw material used was La: Si = 1: 1 (
(Molar ratio) alloy, Si ₃ N ₄ , Y ₂ O ₃ , CeF ₃ , and the ratio is La: Y: Ce: S
LYSN phosphor 2 was obtained by the same procedure as in Example 1 except that i = 2.90: 0.39: 0.26: 6.00 (molar ratio). The powder X-ray diffraction pattern of this phosphor is shown in FIG. The results of calculating the lattice constants a and c based on this data are shown in Table 1. The measurement results of the light emission characteristics are also shown in Table 1.
Using this phosphor, a sintered phosphor was obtained by the procedure of [Production of sintered phosphor] in Example 1.
However, the addition amount of the phosphor was 0.2 g so that the phosphor was 6% by volume with respect to 2.0 g of CaF ₂ .

As an additional heat treatment for the sintered phosphor, the temperature was raised to 1100 ° C. in an Ar atmosphere by a hot isostatic pressing device (HIP) and held at 100 MPa for 1 hour. Φ18mm by this
A sintered phosphor of Example 2 having a thickness of 3 mm was obtained. Subsequent processing and evaluation were performed in the same manner as in Example 1, and evaluation results were obtained in the same manner. The obtained results are shown in Tables 2-4. Moreover, the emission spectrum by LED excitation was shown in FIG.

As shown in Table 2, the sintered phosphor of this embodiment has a high sintered density and transmittance. Furthermore, the sintered body of the present invention has a high quantum yield and absorption rate of excitation light (450 nm).

As shown in Tables 3 and 4, the light emitting device using the sintered phosphor of the present embodiment has high luminous efficiency, high luminance, and can emit light in a low color temperature range with many red components. is there.

(Example 3)
Blue LED with a peak wavelength of 454 nm, the LYSN phosphor 2 and the LSN phosphor (La ₃ S
i ₆ N ₁₁ : Ce) Correlated color temperature 65 produced using BY-201 / F (Mitsubishi Chemical Corporation)
The emission spectrum of the 00K light emitting device was calculated by simulation and shown in FIG. Chromaticity coordinates x of the light emitting device, and, y, color rendering index (Ra, and, R1～R15), correlated color temperature, the difference _{D UV} shown in Table 5.

Example 4
In Example 3, instead of the LSN phosphor BY-201 / F, a YAG phosphor (Y ₃ Al
Except that ₅ O ₁₂ : Ce) BY-102 / H (manufactured by Mitsubishi Chemical Corporation) was used, a spectrum of a light emitting device having a correlated color temperature of 6500 K was obtained by performing a simulation in the same manner as in Example 3. The results are shown in FIG. Chromaticity coordinates x and y of the light emitting device, color rendering index (Ra and R
1 to R15), correlated color temperature, and deviation D _UV are shown in Table 5.

As shown in Table 5, the light emitting device of the present invention is a highly efficient white light emitting device having a correlated color temperature of 6500K. In the configuration of the present embodiment, a sintered phosphor containing two types of phosphors is used, so that the influence of variation among phosphors in lots is offset by adjusting the blending ratio of the two types of phosphors during mass production. This is a light-emitting device that can be easily manufactured.

(Example 5)
A blue LED having a peak wavelength of 454 nm, and the LYSN phosphor 2 and the nitride red phosphor, SCASN phosphor ((Sr, Ca) AlSiN ₃ : Eu) BR-102 / L (manufactured by Mitsubishi Chemical Corporation) were used. The emission spectrum of the light emitting device having a correlated color temperature of 3000 K was calculated by simulation and shown in FIG. Chromaticity coordinates x of the light emitting device, and, y, color rendering index (Ra, and, R1～R15), correlated color temperature, the difference _{D UV} shown in Table 6.

(Examples 6 to 8)
In Example 5, except that the nitride phosphor shown in Table 6 was used instead of BR-102 / L as a nitride red phosphor, a simulation was performed in the same manner as in Example 5 to obtain an emission spectrum of the light emitting device. It was. The obtained emission spectrum is shown in FIG. Chromaticity coordinates x and y of the light emitting device
, Color rendering index (Ra, and, R1～R15), correlated color temperature, the difference _{D UV} shown in Table 6.

(Examples 9 to 12)
A simulation was performed in the same manner as in Example 5 except that the correlated color temperature of the light emitting device was set to 4000 K, and an emission spectrum of the light emitting device was obtained. The obtained emission spectrum is shown in FIG.
Chromaticity coordinates x of the light emitting device, and, y, color rendering index (Ra, and, R1～R15), correlated color temperature, the difference _{D UV} shown in Table 7.

As shown in Table 6, the light-emitting device of the present invention is a light-emitting device that emits light having a low color temperature of a correlated color temperature of 3000K. Because it uses a fluoride inorganic binder with high thermal conductivity,
Even if the output of the blue LED that excites the sintered phosphor is increased, it is expected that the luminous efficiency is unlikely to decrease. In addition, the color rendering properties can be adjusted by changing the type of nitride red phosphor, and the conversion efficiency can be improved by keeping the color rendering properties low, so that the desired conversion efficiency, luminous flux,
A light emitting device exhibiting color rendering can be obtained.

As shown in Table 7, the light-emitting device of the present invention is a light-emitting device that emits light having a low color temperature of a correlated color temperature of 4000K. Because it uses a fluoride inorganic binder with high thermal conductivity,
Even if the output of the blue LED that excites the sintered phosphor is increased, it is expected that the luminous efficiency is unlikely to decrease. In addition, the color rendering properties can be adjusted by changing the type of nitride red phosphor, and the conversion efficiency can be improved by keeping the color rendering properties low, so that the desired conversion efficiency, luminous flux,
A light emitting device exhibiting color rendering can be obtained.
(Example 13)
LYSN phosphor 2 and LSN phosphor (La ₃ Si ₆ N ₁₁ : Ce) BY-20 of Example 2
A sintered phosphor was obtained by the same procedure as in Example 2 using 1 / G (Mitsubishi Chemical Co., Ltd.) mixed powder having a volume ratio of 92: 8. Except for the thickness during processing being 0.24 mm, the subsequent processing and evaluation were performed in the same manner as in Example 1, and the evaluation results were obtained in the same manner. The obtained results are shown in FIG.

(Example 14)
A sintered phosphor was obtained by the same procedure as in Example 2 using a mixed powder of volume ratio 90:10 of LYSN phosphor 2 in Example 2 and YAG phosphor BY-102 / H (Mitsubishi Chemical Corporation). . Except for the thickness at the time of processing being 0.24 mm, the subsequent processing and evaluation were performed in the same manner as in Example 1, and the evaluation results were obtained in the same manner. The obtained results are shown in FIG.

As shown in Table 8, in the configurations of Examples 13 and 14, since sintered phosphors containing two types of phosphors are used, two types of effects of phosphor lot-to-lot variations are produced during mass production. It is a light emitting device that is easy to manufacture in that it can be offset by adjusting the blending ratio of the phosphor.

Claims (9)

A sintered phosphor containing a nitride phosphor and a fluoride inorganic binder,
A sintered phosphor, wherein the nitride phosphor is a phosphor containing a crystal phase represented by the following formula [1].
La _w A _x Si ₆ N _y M _z [1]
M element in the formula represents one or more elements selected from activators,
The A element represents one or more elements selected from rare earth elements other than La and an activating element,
2.0 ≦ w ≦ 4.0,
0 <x ≦ 1.5,
8.0 ≦ y ≦ 14.0,
0.05 ≦ z ≦ 1.0) The fluorescence of the phosphor containing the crystal phase represented by the formula [1] obtained by irradiating excitation light having a wavelength of 455 nm is expressed by the following formula using chromaticity coordinates x and y represented by the CIE1931XYZ color system. The sintered phosphor according to claim 1, wherein:
0.43 ≦ x ≦ 0.50,
0.48 ≦ y ≦ 0.55 The sintered phosphor according to any one of claims 1 to 3, wherein the nitride constant a of the nitride phosphor is not less than 10.104? And not more than 10.185 ?. Furthermore, 1 type, or 2 or more types of other fluorescent substance are contained, The sintered fluorescent substance of any one of Claims 1-3 characterized by the above-mentioned. The sintered phosphor according to any one of claims 1 to 4, and an LED or a semiconductor laser as a light source,
The sintered phosphor emits light having different wavelengths by absorbing at least a part of light from the light source. 6. The light emitting device according to claim 5, wherein a correlated color temperature of light emission is 5000 K or less.   An illumination device comprising the light-emitting device according to claim 5.   An image display device comprising the light-emitting device according to claim 5.   A vehicle indicator lamp comprising the light-emitting device according to claim 5.

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