JP6928424B2 - Fluorescent material and light emitting device - Google Patents

Description

The present invention relates to a phosphor whose brightness is adjusted and a light emitting device.

Light emitting diodes (hereinafter referred to as "LEDs") are required to have a high luminous intensity, but there are also applications in which a lower luminous intensity is required. Such low-luminous LEDs are used, for example, as vehicle interior lighting (heat control switch lamps, window open / close switch lamps, etc.). Such a low-luminous LED can be obtained, for example, by reducing the current value flowing through the LED described in Patent Document 1.

Special Table No. 11-500584

However, for an LED that combines a YAG: Ce phosphor and a light emitting element as disclosed in Patent Document 1, the reason is not clear, but the smaller the current flowing through the light emitting element constituting the LED, the more the light intensity of each light emitting element. It is known that there will be variations in the LED. FIG. 16 shows the relationship of the luminous intensity variation ratio with respect to the current flowing through the LED. Luminous intensity variation is determined by dividing the standard deviation (σ) of the luminous intensity (cd) by the average value of the luminous intensity (cd) (generally referred to as the “coefficient of variation”). The luminous intensity variation ratio is obtained by dividing the luminous intensity variation at each current by the value of the luminous intensity variation at a current of 30 mA.
As shown in FIG. 16, the smaller the current value is, the more the luminous intensity of each light emitting element varies. Therefore, the more the LED having a lower luminous intensity is obtained by only controlling the current value, the more the luminous intensity of each LED becomes. It can be seen that the variation becomes large.
Therefore, one embodiment of the present invention aims to provide a means capable of forming a light emitting device having a lower luminous intensity while suppressing a variation in luminous intensity.

Specific means for solving the above problems are as follows, and the present invention includes the following aspects.
A first aspect of the present invention is a phosphor containing an aluminate activated by Ce and having at least one selected from the group consisting of Y, Gd, Ga and Lu in a composition, wherein the phosphor contains the phosphor. It is a phosphor characterized by containing at least one element selected from the group consisting of lanthanoid elements excluding Ce, Gd and Lu and transition elements of the 4th period in an amount of 100 mass ppm or more and 20000 mass ppm or less.

A second aspect of the present invention is a fluorophore containing an aluminate activated by Ce and having at least one composition selected from the group consisting of Y, Gd, Ga and Lu, wherein the aluminate is used. The fluorescent substance is characterized in that a black pigment of 0.1% by mass or more and 5.0% by mass or less is attached to the containing fluorescent substance.

A third aspect of the present invention is a light emitting device including the phosphor and an excitation light source.

According to one embodiment of the present invention, it is possible to provide a phosphor and a light emitting device that match the desired brightness so that the variation in luminous intensity is suppressed and the luminous intensity becomes lower.

FIG. 1 is a graph showing the relative brightness of the phosphors of Comparative Example 1 and Reference Example 1-1 to Reference Example 1-12. FIG. 2 shows the photoluminescence relative emission intensity (PL Intensity) with respect to the wavelength (wavelength) [nm] for each phosphor of Comparative Example 2, Example 2-8, Reference Example 2-13, and Example 2-21. It is a figure which showed the emission spectrum which shows [au]. FIG. 3 shows the reflectance [%] with respect to the wavelength (wavelength) [nm] for each of the phosphors of Comparative Example 2, Example 2-8, Reference Example 2-13, and Example 2-21. It is a figure which showed the reflection spectrum. FIG. 4 shows the emission spectra showing the photoluminescence relative emission intensity (PL Intensity) [au] with respect to the wavelength (wavelength) [nm] for each of the phosphors of Comparative Example 2, Reference Example 3-3, and Reference Example 3-6. It is a figure which showed. FIG. 5 is a diagram showing reflection spectra showing reflectance [%] with respect to wavelength (wavelength) [nm] for each of the phosphors of Comparative Example 2, Reference Example 3-3, and Reference Example 3-6. Is. FIG. 6 shows the phosphors of Comparative Example 2, Example 2-8, Reference Example 2-13, Reference Example 3-3, and Reference Example 3-6, and the compounds represented by _{Y 3} Al ₅ O _{12, respectively.} It is a figure which compared with the X-ray diffraction pattern of. FIG. 7 is a diagram showing an enlarged X-ray diffraction pattern of the square frame portion A of the X-ray diffraction pattern of the phosphor of Reference Example 3-3 in FIG. In FIG. 7, the diffraction peak surrounded by the circle a1 indicates a unique _{diffraction peak of the black pigment (Fe 3} O _4). FIG. 8 is a diagram showing an enlarged X-ray diffraction pattern of the square frame portion B of each X-ray diffraction pattern of the phosphors of Reference Example 3-3 and Reference Example 3-6 of FIG. In FIG. 8, the diffraction peaks surrounded by the circles b1 to b4 indicate the diffraction peaks peculiar to the black pigment. FIG. 9 is a diagram showing emission spectra showing the photoluminescence relative emission intensity (PL Intensity) [a.u.] With respect to the wavelength (wavelength) [nm] for the phosphors of Comparative Example 4 and Reference Example 4-4. FIG. 10 is a diagram showing reflection spectra showing a reflectance [%] with respect to a wavelength (wavelength) [nm] for the phosphors of Comparative Example 4 and Reference Example 4-4. FIG. 11 is a diagram showing an emission spectrum showing a relative emission intensity (Intensity) [%] with respect to a wavelength (wavelength) [nm] of the light emitting device of Comparative Example 5. FIG. 12 is a diagram showing an emission spectrum showing a relative emission intensity (Intensity) [%] with respect to a wavelength (wavelength) [nm] of the light emitting device of Example 5-1. FIG. 13 is a diagram showing an emission spectrum showing a relative emission intensity (Intensity) [%] with respect to a wavelength (wavelength) [nm] of the light emitting device of Reference Example 5-2. FIG. 14 is a diagram showing an emission spectrum showing a relative emission intensity (Intensity) [%] with respect to a wavelength (wavelength) [nm] of the light emitting device of Reference Example 5-3. FIG. 15 is a diagram showing an emission spectrum showing a relative emission intensity (Intensity) [%] with respect to a wavelength (wavelength) [nm] of the light emitting device of Reference Example 5-4. FIG. 16 is a diagram showing the relationship between the LED current value (mA) and the luminous intensity variation ratio.

Hereinafter, the phosphor and the light emitting device according to the present disclosure will be described based on the embodiments. However, the embodiments shown below are exemplified in order to embody the technical idea of the present invention, and the present invention is not limited to the following embodiments of the present invention. The relationship between the color name and the chromaticity coordinate, the relationship between the wavelength range of light and the color name of monochromatic light, and the like are in accordance with JIS Z8110. In the present specification, the term "process" is included in this term as long as the intended purpose of the process is achieved, not only in an independent process but also in the case where it cannot be clearly distinguished from other processes. Is done. Further, the content of each component in the composition means the total amount of the plurality of substances present in the composition when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified.

(Fluorescent material)
The first aspect of the present invention is an aluminium that is activated by cerium (Ce) and has a composition of at least one selected from the group consisting of yttrium (Y), gadolinium (Gd), gallium (Ga) and lutetium (Lu). At least one selected from the group consisting of a lanthanoid element excluding cerium (Ce), gadolinium (Gd) and yttrium (Lu) and a transition element of the fourth cycle, which is a phosphor containing an acid salt. It is a phosphor containing 100 mass ppm or more and 20000 mass ppm or less of an element.
A phosphor containing an aluminate that is activated by Ce and has a composition of at least one selected from the group consisting of yttrium (Y), gadolinium (Gd), gallium (Ga) and lutetium (Lu) is activated by Ce. It is a garnet-type phosphor particle, and is a phosphor based on a rare earth phosphorate.
A phosphor containing an aluminate that is activated by Ce and has a composition of at least one selected from the group consisting of yttrium (Y), gadolinium (Gd), gallium (Ga) and lutetium (Lu) is represented by the following formula (1). ) Is more preferably contained.
_{(Y 1-v-w Lu} v Gd w) 3-x Ce x (Al 1-y Ga y) 5 O 12 (1)
(In the formula, v, w, x and y are 0 ≦ v ≦ 1.0, 0 ≦ w ≦ 0.9, 0.001 ≦ x ≦ 0.30, and 0 ≦ y ≦ 0.6. 0 ≦ v + w ≦ 1.0).

The phosphor according to the embodiment of the present invention is mainly composed of an aluminate activated by Ce represented by the above formula (1), and is a lanthanoid element excluding cerium (Ce), gadolinium (Gd) and lutetium (Lu). It is preferable that the phosphor contains at least one element selected from the group consisting of transition elements of the fourth period in an amount of 100 mass ppm or more and 20000 mass ppm or less.

V, w, x and y in the formula (1) are not particularly limited as long as they satisfy the above numerical values. x is a Ce activation amount, and may be appropriately selected so as to achieve a desired characteristic. It is preferable that x satisfies 0.001 ≦ x ≦ 0.3 and 0.02 ≦ x ≦ 0.2.

The phosphor according to the first aspect of the present invention is a phosphor that is activated by Ce and contains an aluminate having at least one selected from the group consisting of Y, Gd, Ga and Lu, and has the composition described above. The phosphor contains at least one element selected from the group consisting of lanthanoid elements excluding Ce, Gd and Lu and transition elements of the 4th period in an amount of 100 mass ppm or more and 20000 mass ppm or less.
The lanthanoid elements other than Ce, Gd and Lu and the transition elements of the 4th period may be used alone or in combination of two or more. The content of these elements may be 100 mass ppm or more and 20000 mass ppm or less in the phosphor, and when two or more kinds of elements are contained, the total content of each element is fluorescence. It may be 100 mass ppm or more and 20000 mass ppm or less in the body. It is preferably 200 mass ppm or more and 18,000 mass ppm or less, and more preferably 300 mass ppm or more and 15,000 mass ppm or less.

When the content of the element is less than 100 mass ppm in the phosphor, the amount of the element contained in the phosphor is too small, and the phosphor can be obtained by reducing the brightness to the desired brightness. Can not. On the other hand, if the content of the element exceeds 20000 mass ppm in the phosphor, the amount of the element contained in the phosphor may be too large and the chromaticity may change significantly.

The lanthanoid elements are placeodim (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), uropyum (Eu) terbium (Tb), dysprosium (Dy), holmium (Ho), elbium (Er), thulium ( Tm) and ytterbium (Yb) can be mentioned. Among them, the lanthanoid element is preferably at least one element selected from the group consisting of Pr, Nd, Eu, Ho, Er, and Yb, and more preferably at least selected from the group consisting of Nd, Yb, and Eu. It is one kind of element, and more preferably at least one kind of element selected from the group consisting of Nd and Eu. These lanthanoid elements may be used alone or in combination of two or more.

The transition elements of the 4th period are scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), and copper. (Cu) can be mentioned. Among them, the transition element of the 4th period is preferably at least one element selected from the group consisting of Ti, Cr, Mn, Fe, Co, Ni, and Cu. One of these transition elements of the fourth period may be used alone, or two or more of them may be used in combination.

The phosphor according to the first aspect of the present invention is a phosphor that is activated by Ce and contains an aluminate having at least one selected from the group consisting of Y, Gd, Ga and Lu, and has a composition of Ce. , 0.1% by mass or more and 5.0% by mass or less of a black pigment with respect to a phosphor containing at least one element selected from the group consisting of lanthanoid elements other than Gd and Lu and transition elements of the 4th period. It may be attached. In the phosphor of the present embodiment, by further adhering a black pigment of 0.1% by mass or more and 5.0% by mass or less to the phosphor, all or a part of the surface of the phosphor is a black pigment. It is possible to obtain a phosphor suitable for the desired brightness so as to suppress the variation in luminosity and to have a lower luminosity.
In the fluorescent substance according to the first aspect of the present invention, the amount of the black pigment adhered to the fluorescent substance is preferably 0.3% by mass or more and 3.0% by mass or less, and more preferably 0.5% by mass or less. It is mass% or more and 2.0 mass% or less.
The phosphor according to the first aspect of the present invention is a fluorescence containing an aluminate which is activated by Ce and has at least one selected from the group consisting of Y, Gd, Ga and Lu, excluding the black pigment. It is black with respect to 100% by mass of a phosphor containing at least one element selected from the group consisting of lanthanoid elements excluding Ce, Gd and Lu and transition elements of the fourth period in the phosphor. It is preferable that the pigment is attached in an amount of 0.1% by mass or more and 5.0% by mass or less.

A second aspect of the present invention is an aluminium that is activated by cerium (Ce) and has a composition of at least one selected from the group consisting of yttrium (Y), gadolinium (Gd), gallium (Ga) and lutetium (Lu). It is a phosphor containing an acid salt, and is a phosphor in which a black pigment of 0.1% by mass or more and 5.0% by mass or less is attached to the phosphor containing an aluminate. The phosphor containing aluminate activated by Ce and having at least one selected from the group consisting of Y, Gd, Ga and Lu preferably has a composition represented by the following formula (1).
_{(Y 1-v-w Lu} v Gd w) 3-x Ce x (Al 1-y Ga y) 5 O 12 (1)
(In the formula, v, w, x and y are 0 ≦ v ≦ 1.0, 0 ≦ w ≦ 0.9, 0.001 ≦ x ≦ 0.30, and 0 ≦ y ≦ 0.6. 0 ≦ v + w ≦ 1.0).

V, w, x and y in the formula (1) are not particularly limited as long as they satisfy the above numerical values. x is a Ce activation amount, and may be appropriately selected so as to achieve a desired characteristic. It is preferable that x satisfies 0.001 ≦ x ≦ 0.30 and 0.02 ≦ x ≦ 0.2.

The fluorophore according to the second aspect of the present invention is 0 with respect to a fluorophore containing an aluminate activated by Ce and having at least one selected from the group consisting of Y, Gd, Ga and Lu. . A black pigment of 1% by mass or more and 5.0% by mass or less is attached. Preferably, by coating all or a part of the surface of the phosphor with a black pigment, the variation in luminous intensity is suppressed, and a phosphor having a desired brightness can be obtained so as to have a lower luminous intensity. ..
In the fluorophore according to the second aspect of the present invention, it is black with respect to a fluorophore containing an aluminate activated by Ce and having at least one selected from the group consisting of Y, Gd, Ga and Lu. If the amount of the pigment adhered is less than 0.1% by mass, the amount of the pigment adhered is too small to reduce the brightness of the phosphor until the desired low luminous intensity is obtained, and the phosphor is adjusted to the desired brightness. Can't get. On the other hand, if the amount of the black pigment adhered exceeds 5.0% by mass, the amount of the black pigment adhered is too large to obtain a phosphor suitable for the desired brightness, and the chromaticity may change significantly.
In the fluorescent substance according to the second aspect of the present invention, the fluorescent substance containing an aluminate activated by Ce and having at least one selected from the group consisting of Y, Gd, Ga and Lu is black. The amount of the pigment adhered is preferably 0.3% by mass or more and 3.0% by mass or less, and more preferably 0.5% by mass or more and 2.0% by mass or less.
The phosphor according to the second aspect of the present invention contains 0.1% by mass or more and 5.0% by mass of the black pigment with respect to 100% by mass of the total amount of the black pigment and the phosphor containing the rare earth phosphor. It is attached below.

The black pigment used in the first and second aspects of the present invention is an inorganic pigment, and the inorganic pigment is selected from the group consisting of Ti, Cr, Mn, Fe, Co, Ni, Cu, and Zn. It is preferably an oxide or carbon containing at least one element.
Examples of carbon used as the black pigment include carbon black and graphite.
When the black pigment is an oxide containing at least one element selected from the group consisting of Ti, Cr, Mn, Fe, Co, Ni, Cu, and Zn, it is iron black (titanium oxynitride), low order. It may be an oxide containing one element, such as titanium oxide (Ti ₃ O ₅ , Ti ₂ O ₃ ) or black iron oxide (Fe ₃ O ₄ ), and may be an oxide containing one element, Ni-Fe-based, Cu-Cr-based, Cu. -Fe system, Cu-Zn system, Cu-Fe-Mn system, Cu-Cr-Mn system, Cu-Ce-Fe system, Co-Cr-Fe system, Cu-Cr-Mn-Ni system, 2 It may be a composite oxide containing more than one kind of element.

The phosphor according to the first aspect or the second aspect of the present invention is not particularly limited, but is preferably a powder or a granular material having an average particle size of 3 to 30 μm, and more preferably 5 to 15 μm. .. The average particle size of the phosphor can be measured by the Fisher Sub Sieve Sizer (FSSS) method, and can be measured using, for example, Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific). can.

The phosphor according to the first aspect or the second aspect of the present invention absorbs light in the wavelength range of 380 nm or more and 500 nm or less, which is a region on the short wavelength side of visible light from ultraviolet rays, and has an emission peak wavelength of 510 nm or more and 590 nm. It emits light in the following range.

The phosphor according to the first aspect or the second aspect of the present invention is not particularly limited, but the color emitted when light having a wavelength of 380 nm or more and 500 nm or less is irradiated from the excitation source is on the CIE chromaticity coordinates. The x value of is preferably in the range of 0.330 to 0.510, and the y value is preferably in the range of 0.490 to 0.570.

(Light emitting device)
The light emitting device according to the third aspect of the present invention includes the phosphor according to the first or second aspect of the present invention and an excitation light source.
The phosphor according to the first aspect or the second aspect of the present invention is a component of the wavelength conversion member. A light emitting element can be used as the excitation light source, and the light emitting element preferably emits light in a wavelength range of 380 nm or more and 500 nm or less. The emission peak wavelength of the light emitting element is preferably in the wavelength range of 420 nm or more and 480 nm or less.

The half width of the emission spectrum of the light emitting element is not particularly limited. The full width at half maximum can be, for example, 30 nm or less.
It is preferable to use a semiconductor light emitting element as the light emitting element. By using a semiconductor light emitting device as a light source, it is possible to obtain a stable light emitting device having high efficiency, high linearity of output with respect to input, and resistance to mechanical impact.
As the semiconductor light emitting device, for example, _{a semiconductor light emitting device that emits blue or green light using a nitride-based semiconductor (In X} Al _Y Ga _1-XY N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) is used. Can be used.

The light emitting device using the phosphor according to the first aspect and the second aspect of the present invention may contain another phosphor for adjusting the chromaticity to the extent that the object of the present invention is not impaired. The phosphor according to the embodiment of the present invention emits light from yellow to green when irradiated with light having an excitation source of 380 nm or more and 500 nm or less, and other phosphors have light having an excitation source of 380 nm or more and 500 nm or less. It is preferable that the light emits light in the range of yellow-red to red when irradiated with.
Examples of other phosphors include phosphors represented by the following formulas (I) to (III).
(Ca _1-p-q Sr _p Eu _q ) AlSiN ₃ (I)
(In the formula, p and q are 0 ≦ p ≦ 1.0 and 0 <q <1.0, satisfying p + q <1.0.)
_{(Ca 1-r-s-} t Sr r Ba s Eu t) 2 Si 5 N 8 (II)
(In the formula, r, s, and t are 0 ≦ r ≦ 1.0, 0 ≦ s ≦ 0.1, and 0 <t <1.0, respectively, and satisfy r + s + t ≦ 1.0.)
A ₂ [M ² _1-u Mn ^{4 +} _u F ₆ ] (III)
(In the formula, ^{A, K +, Li +, Na} +, Rb +, at least one cation selected from Cs ⁺ and the group consisting of _NH ^{4 +, M 2} is a Group 4 element and fourteenth It is at least one element selected from the group consisting of group elements, and u satisfies 0 <u <0.2.)

The type of the light emitting device is not particularly limited, and can be appropriately selected from the commonly used types. Examples of the type of light emitting device include a pin-penetrating type and a surface mount type. Generally, the pin-penetrating type refers to a type in which a lead (pin) of a light emitting device is penetrated through a through hole provided in a mounting board to fix the light emitting device. The surface mount type refers to a type in which the leads of the light emitting device are fixed on the surface of the mounting substrate. The light emitting device can be used for illumination that emits white light. Since the light emitting device according to the embodiment of the present invention includes a phosphor that suppresses the variation in luminous intensity and is matched to the target brightness so as to have a lower luminous intensity, it is mounted on a vehicle as a low luminous intensity light emitting device in which the luminous intensity is adjusted. It can be suitably used for lighting for.

(Method for producing a fluorescent substance according to the first aspect)
Next, a method for producing a phosphor according to an embodiment of the present invention will be described.
The phosphor according to the first aspect of the present invention can be produced by the following method.
A phosphor containing an aluminate that is activated by Ce and has at least one selected from the group consisting of Y, Gd, Ga, and Lu, and is a lanthanoid element excluding Ce, Gd, and Lu in the phosphor. A method for producing a phosphor containing at least one element selected from the group consisting of transition elements of the fourth period of 100 mass ppm or more and 20000 mass ppm or less is activated by Ce and consists of Y, Gd, Ga and Lu. From the first raw material containing an oxide, hydroxide or metal salt containing an element constituting the composition of an aluminate having at least one selected from the group, a lanthanoid element and a transition element of the fourth cycle. A second raw material containing an oxide, a sulfide, a metal salt or a simple metal containing at least one element selected from the above group, and the second raw material is 0.01 mass by mass with respect to the first raw material. Includes a step of mixing in% or more and 2.0% by mass or less and firing.

The first raw material is not particularly limited as long as it can constitute the composition of aluminate activated by Ce and having at least one selected from the group consisting of Y, Gd, Ga and Lu. It is more preferable that the aluminate has a composition represented by the formula (1).
As the first raw material, an oxide containing an element constituting the composition of aluminate, which is activated by Ce and has at least one selected from the group consisting of Y, Gd, Ga and Lu, or easily at a high temperature. A compound that becomes an oxide is preferable. As an oxide containing an element that constitutes the composition of an aluminate that is activated by Ce and has at least one selected from the group consisting of Y, Gd, Ga, and Lu, or a compound that easily becomes an oxide at high temperature. Examples include oxides, hydroxides, metal salts and the like containing the above elements. Examples of the metal salt include oxalate, carbonate, chloride, nitrate, sulfate and the like.
Oxides include itterbium oxide (Y ₂ O ₃ ), lutetium oxide (Lu ₂ O ₃ ), gadolinium oxide (Gd ₂ O ₃ ), cerium oxide (CeO ₂ ), aluminum oxide (Al ₂ O ₃ ), and gallium oxide. (Ga ₂ O ₃ ) and the like.
Oxides, hydroxides or metal salts containing elements constituting the composition of the aluminate are weighed in consideration of the stoichiometric ratio and mixed wet or dry using a mixer.

The first raw material is preferably mixed with flux. By adding a flux to the first raw material, the solid-phase reaction can be promoted at a lower temperature to obtain particles having a uniform size. The time when the flux is contained is not particularly limited, but it is preferable that the first raw materials contain the flux in the form of adding the flux after mixing each of the first raw materials so as to obtain the desired composition. As a form in which the flux is added after the first raw material and the second raw material are mixed, the first raw material and the second raw material may further contain the flux.
Examples of the flux include halogen compounds and boron compounds.

In the method for producing a phosphor according to the first aspect of the present invention, an oxide, a sulfide, a metal salt or a simple substance containing at least one element selected from the group consisting of a lanthanoid element and a transition element of the 4th period. The second raw material is mixed in an amount of 0.01% by mass or more and 2.0% by mass or less with respect to the first raw material.

The lanthanoid element is preferably a lanthanoid element excluding Ce, Gd and Lu.
The lanthanoid elements are placeodim (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), and erbium. (Er), thulium (Tm), ytterbium (Yb) can be mentioned. Among them, the lanthanoid element is preferably at least one element selected from the group consisting of Pr, Nd, Eu, Ho, Er, and Yb, and more preferably at least selected from the group consisting of Nd, Yb, and Eu. It is one kind of element, and more preferably at least one kind of element selected from the group consisting of Nd and Eu.
Oxides containing lanthanoid elements include lanthanum oxide (La ₂ O ₃ ), placeodym oxide (Pr ₆ O ₁₁ ), neodymium oxide (Nd ₂ O ₃ ), samarium oxide (Sm ₂ O ₃ ), and europium oxide (Eu _2). O ₃ ), terbium oxide (Tb ₄ O ₇ ), displosium oxide (Dy ₂ O ₃ ), formium oxide (Ho ₂ O ₃ ), erbium oxide (Er ₂ O ₃ ), turium oxide (Tm ₂ O ₃ ), oxidation Itterbium (Yb ₂ O ₃ ) and the like can be mentioned. Examples of the sulfide containing the lanthanoid element include praseodymium sulfide (PrS ₂ ), neodymium sulfide, (NdS ₂ ), europium sulfide (EuS) and the like. Examples of the chloride containing the lanthanoid element include neodymium chloride (NdCl ₂ ) and europium chloride (EuCl ₂ ).
As the oxide, nitride, metal salt or elemental metal containing a lanthanoid element, one type may be used alone, or two or more types may be used in combination.

The transition elements of the 4th period are scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), and copper. (Cu) can be mentioned. Among them, the transition element of the 4th period is preferably at least one element selected from the group consisting of Ti, Cr, Mn, Fe, Co, Ni, and Cu. One of these transition elements of the fourth period may be used alone, or two or more of them may be used in combination.
Oxides containing transition elements in the 4th period include titanium oxide (TiO ₂ ), chromium oxide (Cr ₂ O ₃ ), manganese oxide (Mn ₂ O ₃ ), iron oxide (Fe ₂ O ₃ ), and cobalt oxide (Fe 2 O 3). Co ₂ O ₃ ), nickel oxide (NiO), copper oxide (CuO) and the like.
Sulfides containing transition elements in the 4th cycle include titanium sulfide (TiS), chromium sulfide (CrS), manganese sulfide (MnS), iron sulfide (FeS), cobalt sulfide (CoS), nickel sulfide (NiS), and sulfide. Examples include copper (CuS).
Chlorides containing transition elements in the 4th cycle include titanium chloride (TiCl ₂ ), chromium chloride (CrCl ₂ ), manganese chloride (MnCl ₂ ), iron chloride (FeCl ₂ ), cobalt chloride (CoCl ₂ ), and nickel chloride. (NiCl ₂ ), copper chloride (CuCl ₂ ) and the like can be mentioned.

In the method for producing a phosphor according to the first aspect of the present invention, an oxide, a sulfide, a metal salt or a metal containing at least one element selected from the group consisting of the lanthanoid element and the transition element of the 4th period. The second raw material, which is a simple substance, is mixed with the first raw material in an amount of 0.01% by mass or more and 2.0% by mass or less. By mixing the second raw material with 0.01% by mass or more and 2.0% by mass or less with respect to the first raw material, the lanthanoid element of 100% by mass or more and 20000% by mass or less and the transition of the fourth period A phosphor containing at least one element selected from the group consisting of elements can be obtained.
When the second raw material is mixed with 0.01% by mass or more and 2.0% by mass or less with respect to the first raw material, a group consisting of the lanthanoid element and the transition element of the 4th period in the phosphor. At least one element selected from the above can be contained in an amount of 100% by mass or more and 20000% by mass, and a phosphor can be produced in which the brightness is lowered according to the desired brightness and the change in chromaticity is small.

The method for producing a phosphor according to the first aspect of the present invention is the method for producing a phosphor according to the first raw material and the second raw material in an amount of 0.01% by mass or more and 2.0% by mass or less based on the first raw material. Includes the steps of mixing and firing the raw materials.
The firing can be carried out in an inert atmosphere such as argon or nitrogen, a reducing atmosphere containing hydrogen or the like, or an oxidizing atmosphere such as in the atmosphere.

The firing temperature can be preferably in the range of 1000 ° C. or higher and 2100 ° C. or lower, more preferably 1000 ° C. or higher and 2000 ° C. or lower, and further preferably 1200 ° C. or higher and 1700 ° C. or lower. For firing, for example, an electric furnace, a gas furnace, or the like can be used.
The firing time varies depending on the rate of temperature rise, the firing atmosphere, and the like, but is preferably 1 hour or longer, more preferably 2 hours or longer, and even more preferably 3 hours or longer.

The obtained fluorescent material can be dispersed and then passed through a sieve to obtain a fluorescent material having a desired average particle size.

In the method for producing a fluorescent substance according to the first aspect of the present invention, a fluorescent substance containing an aluminate activated by the Ce and having at least one selected from the group consisting of Y, Gd, Ga and Lu. On the other hand, a step of adhering the black pigment in an amount of 0.1% by mass or more and 5.0% by mass or less may be included.
In the step of adhering the black pigment to the fluorescent substance, the obtained fluorescent substance is dispersed in water, and the black color is 0.1% by mass or more and 5.0 mass or less with respect to the fluorescent substance dispersed in water. A pigment is added to form a mixed solution of the fluorescent substance and the black pigment, and the mixed solution is _{adjusted to pH 5.0 to 8.5 with an aluminum nitrate (Al (NO 3} ) ₃ ) solution or the like to make it black. The pigment can be attached to the phosphor.

In the method for producing a fluorescent substance according to the first aspect of the present invention, the step of further attaching a black pigment of 0.1% by mass or more and 5.0% by mass or less to the fluorescent substance is included. By coating all or a part of the surface of the phosphor with a black pigment, it is possible to suppress the variation in luminous intensity and obtain a phosphor having a desired brightness so as to have a lower luminous intensity.
In the method for producing a phosphor according to the first aspect of the present invention, a black pigment of 0.1% by mass or more and 5.0% by mass or less is attached to 100% by mass of the phosphor excluding the black pigment. Is preferable. It is preferably 0.3% by mass or more and 3.0% by mass or less, and more preferably 0.5% by mass or more and 2.0% by mass or less.

The obtained fluorescent substance to which the black pigment is attached can be dehydrated, dried, and subjected to a dry sieve to obtain a fluorescent substance having a desired average particle size.

(Method for producing a fluorescent substance according to the second aspect)
The method for producing a fluorescent substance according to the second aspect of the present invention is a fluorescent substance containing an aluminate, which is activated by Ce and has at least one selected from the group consisting of Y, Gd, Ga and Lu. The present invention includes a step of adhering a black pigment of 0.1% by mass or more and 5.0% by mass or less to the phosphor containing the aluminate.

The step of adhering the black pigment to a fluorophore containing an aluminate, which is activated by Ce and has at least one selected from the group consisting of Y, Gd, Ga and Lu, is to disperse the fluorophore in water. Then, 0.1% by mass or more and 5.0% by mass or less of the black pigment was dispersed in water with respect to the fluorescent substance dispersed in water to form a mixed solution of the fluorescent substance and the black pigment, and the mixture was formed. The second of the present invention, in which the liquid was adjusted to pH 5.0 to 8.5 with an aluminum nitrate (Al (NO ₃ ) ₃ ) solution or the like, and a black pigment was attached to the phosphor containing the rare earth aluminate. A fluorescent substance according to the embodiment can be obtained.

In the method for producing a phosphor according to the second aspect of the present invention, a phosphor containing an aluminate that is activated by Ce and has at least one selected from the group consisting of Y, Gd, Ga and Lu in a composition. On the other hand, by further including a step of adhering a black pigment of 0.1% by mass or more and 5.0% by mass or less, all or a part of the surface of the phosphor is coated with the black pigment, and the variation in luminous intensity is suppressed. However, it is possible to obtain the phosphor according to the second aspect, which is adjusted to the desired brightness so as to have a lower luminous intensity.
In the method for producing a fluorescent substance according to the second aspect of the present invention, the amount of the black pigment adhered is preferably 0.3% by mass or more and 3.0% by mass or less with respect to the fluorescent substance, which is more preferable. Is 0.5% by mass or more and 2.0% by mass or less.
In the method for producing a fluorescent substance according to the second aspect of the present invention, an aluminate that is activated by a black pigment and Ce and has a composition of at least one selected from the group consisting of Y, Gd, Ga and Lu is contained. A black pigment of 0.1% by mass or more and 5.0% by mass or less is attached with respect to 100% by mass of the total amount of the phosphor.

The black pigment used in the method for producing the fluorescent substance according to the first aspect and the fluorescent substance according to the second aspect of the present invention is an inorganic pigment, and the inorganic pigment is Ti, Cr, Mn, Fe, Co, It is preferably an oxide or carbon containing at least one element selected from the group consisting of Ni, Cu, and Zn.
Examples of carbon used as the black pigment include carbon black and graphite.
When the black pigment is an oxide containing at least one element selected from the group consisting of Ti, Cr, Mn, Fe, Co, Ni, Cu, and Zn, it is iron black (titanium oxynitride), low order. It may be an oxide containing one element, such as titanium oxide (Ti ₃ O ₅ , Ti ₂ O ₃ ) or black iron oxide (Fe ₃ O ₄ ), and may be an oxide containing one element, Ni-Fe-based, Cu-Cr-based, Cu. -Fe system, Cu-Zn system, Cu-Fe-Mn system, Cu-Cr-Mn system, Cu-Ce-Fe system, Co-Cr-Fe system, Cu-Cr-Mn-Ni system, 2 It may be a composite oxide containing more than one kind of element.

Hereinafter, the present invention will be specifically described with reference to Examples, Reference Examples, and Comparative Examples. The phosphors of Examples , Reference Examples and Comparative Examples were evaluated as follows.

(X-ray diffraction spectrum)
X-ray diffraction for the phosphors of Comparative Example 2, Comparative Example 2-8, Comparative Example 2-13, Reference Example 3-3, and Reference Example 3-6, and the compound shown in the composition of _{Y 3} Al ₅ O _12. An X-ray diffraction spectrum (XRD) was measured using a CuKα ray using an apparatus (XRD) (Rigaku Co., Ltd., Ultima IV).

(Relative brightness)
Relative brightness was measured for the fluorescent materials of Comparative Examples, Reference Examples, and Examples. For relative brightness, the measurement sample is irradiated with excitation light with an emission peak wavelength of 450 nm, and each brightness at room temperature (25 ° C ± 5 ° C) is measured using a fluorescence spectrophotometer (QE-2000, manufactured by Otsuka Electronics Co., Ltd.). Then, it was expressed as a relative value (Y (%)) of the emission spectrum of each phosphor of the same wavelength with reference to the brightness of the wavelength having the peak top of the emission spectrum of the phosphor of the comparative example.
The phosphors of Reference Examples 1-1 to 1-12 were based on the brightness of the phosphor of Comparative Example 1.
The phosphors of Examples 2-1 to 2-9, Reference Examples 2-10 to 2-18, and Examples 2-19 to 2-21 were based on the brightness of the phosphor of Comparative Example 2.
The phosphors of Reference Examples 3-1 to 3-6 were based on the brightness of the phosphors of Comparative Example 2.
The phosphors of Reference Examples 4-1 to 4-5 were based on the brightness of the phosphor of Comparative Example 4.

(Relative emission intensity)
The phosphors of Comparative Examples, Reference Examples, and Examples were irradiated with excitation light having a wavelength of 450 nm and used at room temperature (25 ° C ± 5 ° C) using a fluorescence spectrophotometer (QE-2000, manufactured by Otsuka Electronics Co., Ltd.). In, the emission brightness (PL Intensity) with respect to the wavelength was measured and expressed as an emission spectrum. The results are shown in FIGS. 2, 4 and 9. Further, the light emitting devices of Comparative Example 5, Example 5-1 and Reference Examples 5-2 to 5-4 were used at room temperature (25 ° C. ±) using a fluorescence spectrophotometer (QE-2000 manufactured by Otsuka Electronics Co., Ltd.). The emission luminance (PL Intensity) at a wavelength at 5 ° C.) was measured and expressed as an emission spectrum. The results are shown in FIGS. 11-15.

(Reflectance)
For the phosphors of Comparative Examples , Reference Examples, and Examples, the reflected light was measured at room temperature (25 ° C ± 5 ° C) using a spectrofluorometer (Hitachi High-Technologies Co., Ltd., F-4500), and the wavelength was measured. The ratio of reflected light having a wavelength of 450 nm and a wavelength of 600 nm was expressed as reflectance (%). Further, for the phosphors of Comparative Examples, Reference Examples, and Examples, the reflectance with respect to the wavelength was expressed as a reflection spectrum. The results are shown in FIGS. 3, 5 and 10.

(Average particle size)
The average particle size of the phosphors of Comparative Examples , Reference Examples, and Examples was measured by the Fisher Sub Sieve Sizer (FSSS) method using Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific). Was measured.

(X value, y value in CIE chromaticity coordinates)
For the phosphors of Comparative Examples , Reference Examples, and Examples, the x and y values in the CIE chromaticity coordinates are irradiated with excitation light having a wavelength of 450 nm, and a fluorescence spectrophotometer (manufactured by Otsuka Electronics Co., Ltd., QE-2000). Measured in.
Similarly, for the light emitting devices of Comparative Examples , Reference Examples, and Examples, the x and y values in the CIE chromaticity coordinates were measured with a fluorescence spectrophotometer (QE-2000, manufactured by Otsuka Electronics Co., Ltd.). ..

(Relative luminous flux ratio)
For the light emitting devices of Examples , Reference Examples, and Comparative Examples, the luminous flux was measured using the integrated total luminous flux measuring device, and the luminous flux of the light emitting device of Comparative Example 5 using the phosphor of Comparative Example 2 was used as a reference (100%). ) Was calculated as the relative luminous flux (%).

(Comparative Example 1)
The raw materials Y ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ were weighed so as to have a composition ratio of Y: Ce: Al = 2.925: 0.075: 5. _{BaF 2} was added as a flux to this raw material. These raw materials were mixed to obtain a mixture.
This mixture was calcined at 1450 ° C. for 10 hours in a reducing atmosphere to obtain a calcined product having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _12.
The obtained phosphor was dispersed. Then, it was passed through a sieve to produce a phosphor having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _12.

( Reference Example 1-1)
Using the same raw materials as the raw materials of Comparative Example 1, 0.1% by mass of La ₂ O ₃ was added to the total amount of these raw materials and mixed to obtain a mixture.
In the same manner as in Comparative Example 1 except that _{La 2} O ₃ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and La was 700.} A phosphor containing mass ppm was produced.

( Reference Example 1-2)
Using the same raw materials as the raw materials of Comparative Example 1, 0.1% by mass of Tb ₄ O ₇ was added to the total amount of these raw materials and mixed to obtain a mixture.
Similar to Comparative Example 1, except that Tb ₄ O ₇ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and Tb was 700.} A phosphor containing mass ppm was produced.

( Reference Example 1-3)
Using the same raw materials as the raw materials of Comparative Example 1, 0.1% by mass of Dy ₂ O ₃ was added to the total amount of these raw materials and mixed to obtain a mixture.
In the same manner as in Comparative Example 1 except that _{Dy 2} O ₃ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and Dy was 700.} A phosphor containing mass ppm was produced.

( Reference Example 1-4)
Using the same raw materials as the raw materials of Comparative Example 1, 0.1% by mass of Sm ₂ O ₃ was added to the total amount of these raw materials and mixed to obtain a mixture.
Similar to Comparative Example 1, except that Sm ₂ O ₃ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and Sm was 700.} A phosphor containing mass ppm was produced.

( Reference example 1-5)
Using the same raw materials as the raw materials of Comparative Example 1, 0.1% by mass of Tm ₂ O ₃ was added to the total amount of these raw materials and mixed to obtain a mixture.
Similar to Comparative Example 1, except that Tm ₂ O ₃ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and Tm was 800.} A phosphor containing mass ppm was produced.

( Reference example 1-6)
Using the same material and in Comparative Example 1 material, the total amount of these raw materials, was added Pr ₆ O ₁₁ 0.1 wt%, were mixed to obtain a mixture.
In the same manner as in Comparative Example 1 except that _{Pr 6} O ₁₁ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and Pr was 600.} A phosphor containing mass ppm was produced.

( Reference example 1-7)
Using the same raw materials as the raw materials of Comparative Example 1, 0.1% by mass of Er ₂ O ₃ was added to the total amount of these raw materials and mixed to obtain a mixture.
In the same manner as in Comparative Example 1 except that _{Er 2} O ₃ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and Er was 800.} A phosphor containing mass ppm was produced.

( Reference example 1-8)
Using the same raw materials as the raw materials of Comparative Example 1, 0.1% by mass of Ho ₂ O ₃ was added to the total amount of these raw materials and mixed to obtain a mixture.
In the same manner as in Comparative Example 1 except that _{Ho 2} O ₃ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and Ho was 800.} A phosphor containing mass ppm was produced.

( Reference example 1-9)
Using the same raw materials as the raw materials of Comparative Example 1, 0.1% by mass of Yb ₂ O ₃ was added to the total amount of these raw materials and mixed to obtain a mixture.
In the same manner as in Comparative Example 1 except that _{Yb 2} O ₃ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and Yb was 800.} A phosphor containing mass ppm was produced.

( Reference Example 1-10)
Using the same raw materials as the raw materials of Comparative Example 1, 0.1% by mass of Nd ₂ O ₃ was added to the total amount of these raw materials and mixed to obtain a mixture.
Similar to Comparative Example 1, except that Nd ₂ O ₃ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and Nd was 800.} A phosphor containing mass ppm was produced.

( Reference Example 1-11)
Using the same raw materials as those of Comparative Example 1, 0.1% by mass of Eu ₂ O ₃ was added to the total amount of these raw materials and mixed to obtain a mixture.
In the same manner as in Comparative Example 1 except that _{Eu 2} O ₃ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and Eu was 800.} A phosphor containing mass ppm was produced.

( Reference Example 1-12)
Using the same raw materials as the raw materials of Comparative Example 1, 0.1% by mass of Fe ₂ O ₃ was added to the total amount of these raw materials and mixed to obtain a mixture.
In the same manner as in Comparative Example 1 except that _{Fe 2} O ₃ was added, the main component was a rare earth aluminate activated with Ce having a composition of _{Y 2.925} Ce _0.075 Al ₅ O _{12, and Fe was 500.} A phosphor containing mass ppm was produced.

The chemical composition of the phosphor of Comparative Example 1, the chemical composition of the phosphor of Reference Examples 1-1 to 1-12, the amount of oxide added during the production of the phosphor, and the elements added to the phosphor. The content (mass ppm) is shown in Table 1.
Average particle size of the phosphor of Comparative Example 1 and the phosphor of Reference Examples 1-1 to 1-12, x and y values of CIE chromaticity coordinates, relative brightness (Y (%)), reflection at 450 nm and 600 nm. The rates are shown in Table 2. Further, the relative luminance (Y (%)) of the light emitters of Comparative Examples 1 and Reference Examples 1-1 to 1-12 is shown in FIG.

As shown in Table 2, the phosphors of Reference Examples 1-1 to 1-12 containing a specific amount of a specific lanthanoid element or Fe element, which is an element of the 4th period, with respect to the phosphor of Comparative Example 1. The relative brightness could be lowered with respect to the phosphor of Comparative Example 1. In particular, it can be seen that in Reference Examples 1-10 to 1-12, the relative brightness is greatly reduced. The x value and y value of the phosphors of Reference Examples 1-1 to 1-12 in the CIE chromaticity coordinates are x with respect to the x value: 0.447 and y value: 0.535 of the phosphor of Comparative Example 1. The values were 0.441 to 0.452 and the y values were 0.531 to 0.539, and it was confirmed that no large chromaticity deviation occurred. The reflectance at a wavelength of 450 nm is not significantly different from that of the phosphors of Reference Examples 1-1 to 1-11 and that of Comparative Example 1, and the reflectance at a wavelength of 600 nm is also higher than that of Comparative Example 1. There is no significant change in the reflectance of Reference Examples 1-1 to 1-11. On the other hand, the reflectance of the phosphor of Reference Example 1-12 is lower than that of the phosphor of Comparative Example 1 at a wavelength of 450 nm, and the reflectance at a wavelength of 600 nm can also be lower than that of the phosphor of Comparative Example 1. It was found that the light absorption component was increased, a phosphor suitable for the desired brightness could be obtained, and the reflectance could be adjusted.

As shown in FIG. 1, the rate of decrease in brightness differs depending on the element contained in the phosphor, and in Reference Examples 1-1 to 1-12, iron (Fe), which is one of the transition elements of the 4th period, is used. The phosphor of Reference Example 1-12 containing an element was able to have the lowest brightness.

(Comparative Example 2)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.372: 0.593: 0.035: 5. Weighed. _{AlF 3} and H ₃ BO ₃ were added as fluxes to this raw material. These raw materials were mixed in a ball mill to obtain a mixture.
This mixture was calcined at 1400 ° C. for 10 hours in a reducing atmosphere to obtain a calcined product having a composition of _{(Y 0.8} Gd _0.2 ) _2.965 Ce _0.035 Al ₅ O _12.
The obtained phosphor was dispersed. Then, it was passed through a sieve to produce a phosphor having a composition of _{(Y 0.8} Gd _0.2 ) _2.965 Ce _0.035 Al ₅ O _12.

(Example 2-1)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.372: 0.593: 0.035: 5. Weighed. To the total amount of this raw material, 0.05% by mass of Fe ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, Y _0.8 Gd _0.2 ) _2.965 Ce _0.035. A phosphor containing 300 mass ppm of Fe was produced mainly using a rare earth phosphorate activated with Ce having a composition of Al ₅ O _12.

(Example 2-2)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.372: 0.593: 0.035: 5. Weighed. To the total amount of this raw material, 0.1% by mass of Fe ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.8 Gd _0.2 ) _2.965 Ce _{0. A phosphor having a composition of 035} Al ₅ O ₁₂ and mainly containing a Ce-activated rare earth phosphorate containing 400 mass ppm of Fe was produced.

(Example 2-3)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.372: 0.593: 0.035: 5. Weighed. To the total amount of this raw material, 0.5 mass% of Fe ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.8 Gd _0.2 ) _2.965 Ce _0. A phosphor containing 2400 mass ppm of Fe was produced mainly using a rare earth phosphoric acid salt activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

(Example 2-4)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.2375: 0.74125: 0.035: 5. Weighed. To the total amount of this raw material, 0.5 mass% of Fe ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.75 Gd _0.25 ) _2.965 Ce _0. A phosphor containing 2400 mass ppm of Fe was produced mainly using a rare earth phosphoric acid salt activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

(Example 2-5)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.0755: 0.8895: 0.035: 5. Weighed. To the total amount of this raw material, 0.5 mass% of Fe ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.7 Gd _0.3 ) _2.965 Ce _0. A phosphor containing 2400 mass ppm of Fe was produced mainly using a rare earth phosphoric acid salt activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

(Example 2-6)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.0755: 0.8895: 0.035: 5. Weighed. To the total amount of this raw material, 0.8% by mass of Fe ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.7 Gd _0.3 ) _2.965 Ce _0. A phosphor containing 3600 mass ppm of Fe was produced mainly using a rare earth phosphoric acid salt activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

(Example 2-7)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 1.92725: 1.03775: 0.035: 5. Weighed. To the total amount of this raw material, 0.8% by mass of Fe ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.65 Gd _0.35 ) _2.965 Ce _0. A phosphor containing 3600 mass ppm of Fe was produced mainly using a rare earth phosphoric acid salt activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

(Example 2-8)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 1.92725: 1.03775: 0.035: 5. Weighed. To the total amount of this raw material, 1.0% by mass of Fe ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.65 Gd _0.35 ) _2.965 Ce _0. A phosphor containing 4500 mass ppm of Fe was produced mainly using a rare earth phosphoric acid salt activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

(Example 2-9)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 1.779: 1.186: 0.035: 5. Weighed. To the total amount of this raw material, 1.0 mass% of Fe ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.6 Gd _0.4 ) _2.965 Ce _0. A phosphor containing 4500 mass ppm of Fe was produced mainly using a rare earth phosphoric acid salt activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

( Reference Example 2-10)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.372: 0.593: 0.035: 5. Weighed. To the total amount of this raw material, 0.1% by mass of Eu ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.8 Gd _0.2 ) _2.965 Ce _0. A phosphor containing 800 mass ppm of Eu was produced mainly by a rare earth phosphor acid salt activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

( Reference Example 2-11)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.372: 0.593: 0.035: 5. Weighed. To the total amount of this raw material, 0.5% by mass of Eu ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.8 Gd _0.2 ) _2.965 Ce _{0. A phosphor having a composition of 035} Al ₅ O ₁₂ and mainly containing a Ce-activated rare earth phosphor and containing 4000 mass ppm of Eu was produced.

( Reference Example 2-12)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.0755: 0.8895: 0.035: 5. Weighed. To the total amount of this raw material, 0.8% by mass of Eu ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.7 Gd _0.3 ) _2.965 Ce _{0. A phosphor having a composition of 035} Al ₅ O ₁₂ and mainly containing a Ce-activated rare earth phosphor and containing 6200 mass ppm of Eu was produced.

( Reference Example 2-13)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.0755: 0.8895: 0.035: 5. Weighed. To the total amount of this raw material, 1.3% by mass of Eu ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.7 Gd _0.3 ) _2.965 Ce _{0. A phosphor having a composition of 035} Al ₅ O ₁₂ and mainly containing a Ce-activated rare earth phosphor and containing 11,000 mass ppm of Eu was produced.

( Reference Example 2-14)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 1.92725: 1.03775: 0.035: 5. Weighed. To the total amount of this raw material, 0.8% by mass of Eu ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.65 Gd _0.35 ) _2.965 Ce _0. A phosphor containing 6200 mass ppm of Eu was produced mainly using a rare earth aluminate activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

( Reference Example 2-15)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 1.92725: 1.03775: 0.035: 5. Weighed. _{1.0% by mass of Eu 2} O ₃ was added to the total amount of this raw material, and otherwise in the same manner as in Comparative Example 2 (Y _0.65 Gd _0.35 ) _2.965 Ce _0. A phosphor containing 7800 mass ppm of Eu was produced mainly using a rare earth aluminate activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

( Reference Example 2-16)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 1.92725: 1.03775: 0.035: 5. Weighed. To the total amount of this raw material, 1.3% by mass of Eu ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.65 Gd _0.35 ) _2.965 Ce _0. A phosphor containing 11,000 mass ppm of Eu was produced mainly using a rare earth aluminate activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

( Reference Example 2-17)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 1.779: 1.186: 0.035: 5. Weighed. To the total amount of this raw material, 1.0% by mass of Eu ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.6 Gd _0.4 ) _2.965 Ce _{0. A phosphor having a composition of 035} Al ₅ O ₁₂ and mainly containing a Ce-activated rare earth phosphor and containing 7800 mass ppm of Eu was produced.

( Reference Example 2-18)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 1.779: 1.186: 0.035: 5. Weighed. To the total amount of this raw material, 1.3% by mass of Eu ₂ O ₃ was added, and other than that, in the same manner as in Comparative Example 2, (Y _0.6 Gd _0.4 ) _2.965 Ce _0. A phosphor containing 11,000 mass ppm of Eu was produced mainly using a rare earth aluminate activated with Ce having a composition of ₀₃₅ Al ₅ O _12.

(Example 2-19)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.372: 0.593: 0.035: 5. Weighed. To the total amount of this raw material, 0.05% by mass of Fe ₂ O ₃ and 0.05% by mass of Eu ₂ O _{3 were} added, and other than that, in the same manner as in Comparative Example 2, (Y _0.8 Gd). _0.2 ) _2.965 Ce _0.035 A phosphor containing 300 mass ppm of Fe and 300 mass ppm of Eu was produced mainly by a rare earth phosphoric acid salt activated by Ce having a composition of Al ₅ O _12. ..

(Example 2-20)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.372: 0.593: 0.035: 5. Weighed. To the total amount of this raw material, 0.1% by mass of Fe ₂ O ₃ and 0.1% by mass of Eu ₂ O _{3 were} added, and other than that, in the same manner as in Comparative Example 2, (Y _0.8 Gd). _0.2 ) _2.965 Ce _0.035 A phosphor containing 600 mass ppm of Fe and 800 mass ppm of Eu was produced mainly by a rare earth phosphoric acid salt activated by Ce having a composition of Al ₅ O _12. ..

(Example 2-21)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.372: 0.593: 0.035: 5. Weighed. To the total amount of this raw material, 0.5% by mass of Fe ₂ O ₃ and 0.5% by mass of Eu ₂ O _{3 were} added, and other than that, in the same manner as in Comparative Example 2, (Y _0.8 Gd). _0.2 ) _2.965 Ce _0.035 A phosphor containing 2600 mass ppm of Fe and 3800 mass ppm of Eu was produced mainly by a rare earth phosphoric acid salt activated by Ce having a composition of Al ₅ O _12. ..

Chemical assembly of phosphors of Comparative Example 2 and Examples 2-1 to 2-9, Reference Examples 2-10 to 2-18, and Examples 2-19 to 2-21 and addition of oxides added during phosphor production. Table 3 shows the amount and the content (mass ppm) of the element added to the phosphor.
Average particle size, x-value and y of CIE chromaticity coordinates of the phosphors of Comparative Example 2 and Examples 2-1 to 2-9, Reference Examples 2-10 to 2-18, and Examples 2-19 to 2-21. Table 4 shows the values, relative brightness (Y (%)) and reflectance at 450 nm and 600 nm.

FIG. 2 shows emission spectra showing the photoluminescence relative emission intensity (PL Intensity) with respect to the wavelengths of the phosphors of Comparative Example 2, Example 2-8, Reference Example 2-13, and Example 2-21.
FIG. 3 shows the reflection spectra showing the reflectance of the phosphors of Comparative Example 2, Example 2-8, Reference Example 2-13, and Example 2-21 with respect to the wavelength.

As shown in Table 4, the phosphors of Examples 2-1 to 2-9, Reference Examples 2-10 to 2-18, and Examples 2-19 to 2-21 containing either one or both of Fe and Eu are , The relative brightness could be lowered with respect to the phosphor of Comparative Example 2.
Further, the phosphors of Examples 2-1 to 2-9, Reference Examples 2-10 to 2-18, and Examples 2-19 to 2-21 containing either one or both of Fe and Eu are added elements. It was confirmed that the relative brightness could be lowered in proportion to the content of the above, and a phosphor suitable for the desired brightness could be obtained.
The x-value and y-value of the phosphors of Examples 2-1 to 2-9, Reference Examples 2-10 to 2-18, and Examples 2-19 to 2-21 in the CIE chromaticity coordinates are the fluorescence of Comparative Example 2. The x value of the body is 0.461 and the y value is 0.523, whereas the x value is 0.451 to 0.475 and the y value is 0.515 to 0.536. Alternatively, when the Eu content was increased, there was a tendency for a slight chromaticity shift to occur.
The reflectance at a wavelength of 450 nm is significantly different between the phosphors of Examples 2-1 to 2-9, Reference Examples 2-10 to 2-18, and Examples 2-19 to 2-21 and the phosphors of Comparative Example 2. However, the reflectance at a wavelength of 600 nm is that of Examples 2-1 to 2-9, Reference Examples 2-10 to 2-18, and Examples 2-19 to 2-9 with respect to the reflectance of the phosphor of Comparative Example 2. The reflectance of the 2-21 phosphor can be lowered, in other words, the light absorption rate can be increased to obtain a phosphor that matches the desired brightness, and the light intensity can be adjusted. I found out.

As shown in FIG. 2, the relative brightness of the phosphors of Example 2-8 and Reference Example 2-13 is 20% or less, respectively, with respect to 100% of the relative brightness of the phosphor of Comparative Example 2. It was confirmed that the brightness was lowered according to the low luminous intensity and a phosphor suitable for the desired brightness was obtained.
As shown in FIG. 3, the reflectances of the phosphors of Example 2-8, Reference Example 2-13, and Example 2-21 can have a reflectance at a wavelength of 600 nm lower than that of Comparative Example 2. It was confirmed that the brightness was lowered so as to increase the light reflectance and obtain the low luminous intensity according to the purpose, and a phosphor suitable for the desired brightness could be obtained.

(Comparative Example 3)
The raw materials Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ have a composition ratio of Y: Gd: Ce: Al = 2.565: 0.285: 0.15: 5. Weighed. _{AlF 3} and H ₃ BO ₃ were added as fluxes to this raw material. These raw materials were mixed to obtain a mixture.
This mixture was calcined at 1400 ° C. for 10 hours in a reducing atmosphere to obtain a calcined product having a composition of _{(Y 0.9} Gd _0.1 ) _2.85 Ce _0.15 Al ₅ O _12.
The obtained phosphor was dispersed. Then, it was passed through a sieve to produce a phosphor having a composition of _{(Y 0.9} Gd _0.1 ) _2.85 Ce _0.15 Al ₅ O _12.

( Reference Example 3-1)
The fluorescent substance produced in Comparative Example 2 was put into water, stirred and dispersed, and 0.5% by mass of a black pigment (Fe ₃ O ₄ ) was added to the fluorescent substance to obtain the fluorescent substance and the black pigment. A mixed solution of the above was obtained.
To this mixed solution, a solution of Al (NO ₃ ) ₃ was added in an amount of 0.05% by mass based on a phosphor having a composition of (Y _0.9 Gd _0.1 ) _2.85 Ce _0.15 Al ₅ O _12. Then, the pH was adjusted to 6.5, and the phosphor was coated with a _{black pigment (Fe 3} O _4).
Then, it is dehydrated, dried, and passed through a dry sieve to obtain a phosphor having a composition of _{(Y 0.8} Gd _0.2 ) _2.965 Ce _0.035 Al ₅ O _{12 coated with a black pigment.} Manufactured.

( Reference example 3-2)
In the same manner as in Example 3-1 except that 1.0% by mass of a black pigment (Fe ₃ O _{4 ) was added to the phosphor produced in Comparative Example 2, (Y 0.8} Gd _{0). .2} ) _{A fluorescent substance having a composition of 2.965} Ce _0.035 Al ₅ O ₁₂ coated with a black pigment was produced.

( Reference example 3-3)
Example 3-1 and the same as in Example 3-1 except that the fluorescent substance produced in Comparative Example 3 was used and 1.0% by mass of a black pigment (Fe ₃ O _{4) was added to the fluorescent substance produced in Comparative Example 3.} Similarly, _{a phosphor having a composition of (Y 0.9} Gd _0.1 ) _2.85 Ce _0.15 Al ₅ O ₁₂ was coated with a black pigment to produce a phosphor.

( Reference example 3-4)
In the same manner as in Example 3-1 except that 0.5% by mass of a black pigment (Cu [Fe, Mn] O _{4 ) was added to the phosphor produced in Comparative Example 2, (Y 0). .8} Gd _{0.2) 2.965} was produced Ce _0.035 Al ₅ phosphor coated with black pigment to the phosphor having a composition of O _12.

( Reference example 3-5)
In the same manner as in Example 3-1 except that 1.0% by mass of a black pigment (Cu [Fe, Mn] O _{4 ) was added to the phosphor produced in Comparative Example 2, (Y 0). .8} Gd _{0.2) 2.965} was produced Ce _0.035 Al ₅ phosphor coated with black pigment to the phosphor having a composition of O _12.

( Reference example 3-6)
Examples except that the phosphor produced in Comparative Example 3 was used and 1.0% by mass of a black pigment (Cu [Fe, Mn] O ₄ ) was added to the phosphor produced in Comparative Example 3. In the same manner as in 3-1 _{a phosphor having a composition of (Y 0.9} Gd _0.1 ) _2.85 Ce _0.15 Al ₅ O ₁₂ was coated with a black pigment to produce a phosphor.

Table 5 shows the chemical composition of the phosphors of Comparative Examples 2 to 3 and Reference Examples 3-1 to 3-6 and the amount of the black pigment added during the production of the phosphor.
The average particle size of the phosphors of Comparative Examples 2 to 3 and Reference Examples 3-1 to 3-6, the x and y values of the CIE chromaticity coordinates, the relative brightness (Y (%)) and the reflectance at 450 nm and 600 nm. It is shown in Table 6.

FIG. 4 shows emission spectra showing the photoluminescence relative emission intensity (PL Intensity) with respect to the wavelengths of the phosphors of Comparative Example 2, Reference Examples 3-3, and 3-6.
FIG. 5 shows the reflection spectra showing the reflectance of the phosphors of Comparative Example 2, Reference Examples 3-3, and 3-6 with respect to the wavelength.

FIG. 6 shows the phosphors of Comparative Example 2, Example 2-8, Reference Example 2-13, Reference Example 3-3, and Reference Example 3-6, and the compounds represented by _{Y 3} Al ₅ O _{12, respectively.} It was compared with the X-ray diffraction pattern of.
FIG. 7 is a diagram showing an enlarged X-ray diffraction pattern of the square frame portion A of the X-ray diffraction pattern of the phosphor of Reference Example 3-3 in FIG. In FIG. 7, the diffraction peak surrounded by the circle a1 indicates a unique _{diffraction peak of the black pigment (Fe 3} O _4).
FIG. 8 is a diagram showing an enlarged X-ray diffraction pattern of the square frame portion B of each X-ray diffraction pattern of the phosphors of Reference Example 3-3 and Reference Example 3-6 of FIG. In FIG. 8, the diffraction peaks surrounded by the circles b1 to b4 indicate the diffraction peaks peculiar to the black pigment.

As shown in Table 6, the phosphors of Reference Examples 3-1 to 3-6 to which the black pigment is attached can have a lower relative brightness than the phosphors of Comparative Example 2 or Comparative Example 3, and the purpose is It was confirmed that a phosphor suitable for the brightness of the above can be obtained.
The x-value and y-value of the phosphors of Reference Examples 3-1, 3-2, 3-4 and 3-5 in the CIE chromaticity coordinates are the x-value of the phosphor of Comparative Example 2: 0.461 and the y-value: With respect to 0.523, the x value: 0.446 to 0.445 and the y value: 0.529 to 0.535 tended to cause a slight chromaticity deviation.
The x value and y value of the phosphors of Reference Examples 3-3 and 3-6 in the CIE chromaticity coordinates are x with respect to the x value: 0.474 and y value: 0.514 of the phosphor of Comparative Example 3. The values were 0.446 to 0.462 and the y values were 0.521 to 0.525, which tended to cause a slight chromaticity deviation.
Both the reflectance at a wavelength of 450 nm and the reflectance at a wavelength of 600 nm are higher than those of the phosphors of Comparative Examples 2 and 3 in the phosphors of Reference Examples 3-1 to 3-6 at both a wavelength of 450 nm and a wavelength of 600 nm. It was confirmed that the reflectance was lowered, in other words, the reflectance of light was increased to obtain a phosphor suitable for the desired brightness, and the light intensity could be adjusted.

As shown in FIG. 4, the relative brightness of the phosphors of Reference Examples 3-3 and 3-6 is 40% or less, respectively, with respect to the relative brightness of 100% of the phosphor of Comparative Example 2, and the desired brightness is achieved. It was confirmed that a combined phosphor could be obtained.
As shown in FIG. 5, in the phosphors of Reference Examples 3-3 and 3-6, the reflectance at a wavelength of 600 nm is lower than that of Comparative Example 2, and the light absorption rate is increased. It was confirmed that a phosphor suitable for the desired brightness could be obtained and the reflectance could be adjusted.

As shown in X-ray diffraction pattern of FIG. 6, the phosphor of Example 3-3,3-6, the phosphor of Comparative Example 2, Example 2-8, the phosphor of Example 2-13, It has peaks in different parts, and this peak indicates the diffraction peak of the black pigment.
FIG. 7 is a diagram showing an enlarged X-ray diffraction pattern of the square frame portion A of the X-ray diffraction pattern of the phosphor of Reference Example 3-3 in FIG. In FIG. 7, the diffraction peak surrounded by the circle a1 is a diffraction peak _{peculiar to the black pigment (Fe 3} O ₄ ), and the phosphor of Reference Example 3-3 has the black pigment attached to the surface. I understand.
FIG. 8 is a diagram showing an enlarged X-ray diffraction pattern of the square frame portion B of each X-ray diffraction pattern of the phosphors of Reference Examples 3-3 and 3-6 of FIG. In FIG. 8, the diffraction peaks surrounded by circles b1 to b4 are diffraction peaks peculiar to black pigments (Fe ₃ O ₄ , Cu [Fe, Mn] O ₄ ), and are reference examples 3-3 and 3-6. It can be seen that the black pigment is attached to the surface of the phosphor of.

(Comparative Example 4)
The raw materials Y ₂ O ₃ , CeO ₂ , Al ₂ O ₃ , and Ga ₂ O ₃ were weighed so as to have a composition ratio of Y: Ce: Al: Ga = 2.965: 0.035: 4: 1. .. _{AlF 3} and H ₃ BO ₃ were added as fluxes to this raw material. These raw materials were mixed in a ball mill to obtain a mixture.
This mixture was calcined at 1400 ° C. for 10 hours in a reducing atmosphere to obtain a calcined product having a composition of _{Y 2.965} Ce _0.035 (Al _0.8 Ga _0.2 ) ₅ O _12.
The obtained phosphor was dispersed. Then, it was passed through a sieve to produce a phosphor having a composition of _{Y 2.965} Ce _0.035 (Al _0.8 Ga _0.2 ) ₅ O _12.

( Reference example 4-1)
The raw materials Y ₂ O ₃ , CeO ₂ , Al ₂ O ₃ , and Ga ₂ O ₃ were weighed so as to have a composition ratio of Y: Ce: Al: Ga = 2.965: 0.04: 4: 1. .. To the total amount of this raw material, 0.05% by mass of Eu ₂ O ₃ was added, and otherwise in the same manner as in Comparative Example 4, Y _2.965 Ce _0.040 (Al _0.8 Ga _{0. 2} ) A phosphor containing 300 mass ppm of Eu was produced mainly using a rare earth phosphor acid salt activated with Ce having a composition of ₅ O _12.

( Reference example 4-2)
The raw materials Y ₂ O ₃ , CeO ₂ , Al ₂ O ₃ , and Ga ₂ O ₃ were weighed so as to have a composition ratio of Y: Ce: Al: Ga = 2.965: 0.04: 4: 1. .. _{0.06% by mass of Eu 2} O ₃ was added to the total amount of this raw material, and otherwise in the same manner as in Comparative Example 4, Y _2.965 Ce _0.040 (Al _0.8 Ga _{0. 2} ) A phosphor containing 400 mass ppm of Eu was produced mainly by a rare earth phosphor acid salt activated with Ce having a composition of ₅ O _12.

( Reference example 4-3)
The raw materials Y ₂ O ₃ , CeO ₂ , Al ₂ O ₃ , and Ga ₂ O ₃ were weighed so as to have a composition ratio of Y: Ce: Al: Ga = 2.965: 0.042: 4: 1. .. To the total amount of this raw material, 0.05% by mass of Eu ₂ O ₃ was added, and otherwise in the same manner as in Comparative Example 4, Y _2.965 Ce _0.042 (Al _0.8 Ga _{0. 2} ) A phosphor containing 300 mass ppm of Eu was produced mainly using a rare earth phosphor acid salt activated with Ce having a composition of ₅ O _12.

( Reference example 4-4)
The raw materials Y ₂ O ₃ , CeO ₂ , Al ₂ O ₃ , and Ga ₂ O ₃ were weighed so as to have a composition ratio of Y: Ce: Al: Ga = 2.965: 0.042: 4: 1. .. _{0.06% by mass of Eu 2} O ₃ was added to the total amount of this raw material, and otherwise in the same manner as in Comparative Example 4, Y _2.965 Ce _0.042 (Al _0.8 Ga _{0. 2} ) A phosphor containing 400 mass ppm of Eu was produced mainly by a rare earth phosphor acid salt activated with Ce having a composition of ₅ O _12.

( Reference example 4-5)
The raw materials Y ₂ O ₃ , CeO ₂ , Al ₂ O ₃ , and Ga ₂ O ₃ were weighed so as to have a composition ratio of Y: Ce: Al: Ga = 2.965: 0.042: 4: 1. .. _{0.07% by mass of Eu 2} O ₃ was added to the total amount of this raw material, and otherwise in the same manner as in Comparative Example 4, Y _2.965 Ce _0.042 (Al _0.8 Ga _{0. 2} ) A phosphor containing 500 mass ppm of Eu was produced mainly using a rare earth phosphor acid salt activated with Ce having a composition of ₅ O _12.

Comparative Example 4 and the addition amount of oxide added during manufacture of the chemical composition and the phosphor of the phosphor of Reference Example 4-1 to 4-5, the content of the element in the phosphor (mass ppm) in Table 7 show.
The average particle diameter of the phosphor of Comparative Example 4 and Reference Example 4-1 to 4-5, x and y values of CIE chromaticity coordinates, the relative luminance (Y (%)) and Table 8 the reflectance at 450nm and 600nm Shown in.

FIG. 9 shows emission spectra showing the photoluminescence relative emission intensity (PL Intensity) with respect to the wavelengths of the phosphors of Comparative Example 4 and Reference Example 4-4.
FIG. 10 shows the reflection spectra showing the reflectance of the phosphors of Comparative Example 4 and Reference Example 4-4 with respect to the wavelength.

As shown in Table 8, the phosphors of Reference Examples 4-1 to 4-5 containing Eu can have a lower relative brightness than the phosphor of Comparative Example 4, and the fluorescence is adjusted to the desired brightness. I was able to confirm that I could get a body.
The x-value and y-value of the phosphors of Reference Examples 4-1 to 4-5 in the CIE chromaticity coordinates are x-value: 0381 and y-value: 0.564 of the phosphor of Comparative Example 4. It was 0.381 to 0.384, and the y value was 0.564 to 0.565, and it was confirmed that no chromaticity deviation occurred.
In the phosphors of Reference Examples 4-1 to 4-5, the reflectance at a wavelength of 450 nm can be slightly lower than that of the phosphor of Comparative Example 4, and the absorption rate is increased to match the desired brightness. It was confirmed that a phosphor could be obtained and the luminous intensity could be adjusted.

As shown in FIG. 9, it was confirmed that the relative brightness of the phosphor of Reference Example 4-4 can be lowered with respect to the relative brightness of 100% of the phosphor of Comparative Example 4, and the luminous intensity can be adjusted. did it.
As shown in FIG. 10, it was confirmed that the reflectance of the phosphor of Reference Example 4-4 can be slightly lower than the reflectance of Comparative Example 4 at a wavelength of 450 nm, and the luminous intensity can be adjusted. did it.

(Comparative Example 5)
Using the phosphor of Comparative Example 2, an LED element made of a nitride semiconductor having an emission peak wavelength of 455 nm is provided as a light source, and a silicone resin is filled in a recess of a package, and a fluorescence resin containing the phosphor shown in Table 9 is used for fluorescence. The amount (% by mass) of the phosphor shown in Table 9 was added to 100% by mass of the composition, the obtained fluorescent composition was injected into the package, and the resin in the fluorescent composition was cured. A light emitting device was manufactured.

(Example 5-1)
A light emitting device was produced in the same manner as in Comparative Example 5 except that the phosphor of Example 2-8 was used in the amount shown in Table 9.

( Reference example 5-2)
A light emitting device was produced in the same manner as in Comparative Example 5 except that the phosphors of Reference Example 2-14 were used in the amounts shown in Table 9.

( Reference example 5-3)
A light emitting device was produced in the same manner as in Comparative Example 5 except that the phosphor of Reference Example 3-3 was used in the amount shown in Table 9.

( Reference example 5-4)
A light emitting device was produced in the same manner as in Comparative Example 5 except that the phosphors of Reference Example 3-6 were used in the amounts shown in Table 9.

Table 9 shows the x-value and y-value of the CIE chromaticity coordinates of the light emitting devices of Comparative Example 5, Example 5-1 and Reference Example 5-2-5-4, and the relative luminous flux ratio (%).

FIG. 11 shows an emission spectrum showing the relative emission intensity (Intensity) with respect to the wavelength (wavelength) of the light emitting device of Comparative Example 5.
FIG. 12 shows an emission spectrum showing the relative emission intensity (Intensity) with respect to the wavelength (wavelength) of the light emitting device of Example 5-1.
FIG. 13 shows an emission spectrum showing the relative emission intensity (Intensity) with respect to the wavelength (wavelength) of the light emitting device of Reference Example 5-2.
FIG. 14 shows an emission spectrum showing the relative emission intensity (Intensity) with respect to the wavelength (wavelength) of the light emitting device of Reference Example 5-3.
FIG. 15 shows an emission spectrum showing the relative emission intensity (Intensity) with respect to the wavelength (wavelength) of the light emitting device of Reference Example 5-4.

As shown in Table 9, the light emitting devices of Example 5-1 and Reference Examples 5-2 to 5-4 have a smaller luminous flux ratio and lower relative brightness than the light emitting devices of Comparative Example 5, and are adjusted to the desired brightness. It was confirmed that a light emitting device having an adjusted luminous intensity was manufactured by using the fluorescent material.

As shown in FIGS. 11 to 15, the light emitting devices of Examples 5-1 and Reference Examples 5-2 to 5-4 have a lower emission intensity at a wavelength of 500 to 600 nm than the light emitting device of Comparative Example 5. In addition, the emission intensity at a wavelength of 455 nm, which is the excitation wavelength of the light emitting element, could be significantly reduced. In particular, in Reference Examples 5-3 and 5-4, the emission intensity at a wavelength of 455 nm could be lowered because of the wavelengths in the phosphors of Reference Examples 3-3 and 3-6, as shown in FIG. It is considered that the light absorption rate increased as a result of the decrease in the reflectance near 455 nm. From this result, it was confirmed that by using the phosphors of this example and the reference example , a light emitting device having a low luminous intensity could be obtained, not only by controlling the current value.

According to the present invention, it is possible to provide a phosphor and a light emitting device that match the desired brightness so as to suppress the variation in luminous intensity and reduce the luminous intensity. Further, as a low luminous intensity light emitting device having an adjusted luminous intensity, it can be suitably used for in-vehicle lighting.

Claims (2)

A phosphor containing aluminate having a composition represented by the following formula (1), which contains Fe in an amount of 300 mass ppm or more and 4500 mass ppm or less .
_{(Y 1-v-w Lu} v Gd w) 3-x Ce x (Al 1-y Ga y) 5 O 12 (1)
(In the equation, v, w, x and y are v = 0 , 0.2 ≦ w ≦ 0.4 , x = 0.035 , and y = 0 ).
The phosphor is a fired body of a mixture containing a first raw material and a second raw material.
The first raw material is a raw material that can form the composition of the aluminate.
The second raw material is a phosphor which is an oxide, a sulfide, a salt of Fe, or a simple substance of Fe. A light emitting device including the phosphor according to claim 1 and an excitation light source.

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