JP2018059071A - Manufacturing method of nitride phosphor and nitride phosphor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a nitride phosphor and the nitride phosphor.SOLUTION: There is provided a manufacturing method of nitride phosphor including a process for a heat treatment of a first compound containing one or more kind of element selected from Ba, Sr, Ca or the like, a second compound containing one or more kind of element selected from Eu, Ce, Tb or the like, and a compound containing Si in atmosphere containing nitrogen to obtain a raw material burned article, and a process for a heat treatment of the raw material burned article, a compound containing Ba, and if needed, one or more kind of third compound selected from Eu, Ce or the like, if needed, a fourth compound containing one or more kind of alkali earth metal selected from Sr, Ca and Mg in nitrogen atmosphere to obtain the nitride phosphor, a ratio of total molar quantity of one more kind of alkali earth metal element contained in the raw material burned article in the process for obtaining the raw material burned article to molar quantity of only Ba is smaller than a ratio of total molar quantity of one or more kind of alkali earth metal element contained in the nitride phosphor in the process for obtaining the nitride phosphor to molar quantity of only Ba.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a nitride phosphor and a nitride phosphor.

  Light emitting devices combining light emitting diodes (hereinafter referred to as “LEDs”) and phosphors are actively applied to lighting devices, backlights of liquid crystal display devices, small strobes, etc. It is out. In order to emit light including red from such a light emitting device, a phosphor having an emission peak wavelength in a wavelength range of 570 nm to 670 nm is required as a phosphor emitting red light.

As such a phosphor, for example, Patent Document 1 discloses that a nitride phosphor using (Ba, Sr, Ca) ₂ Si ₅ N ₈ as a base crystal and divalent europium (Eu ²⁺ ) as an activation element. Is disclosed.

Special table 2003-515655 gazette

However, in the method for producing a nitride phosphor having the above composition, it tends to be difficult to obtain a nitride phosphor having a large particle size and a good particle shape in a high yield.
Accordingly, an object of one embodiment of the present invention is to provide a method for producing a nitride phosphor having a large particle size and a good particle shape in a high yield, and a nitride phosphor.

Means for solving the above-mentioned problems are as follows, and the present invention includes the following aspects.
A first aspect of the present invention is a first compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca and Mg, and a group consisting of Eu, Ce, Tb and Mn. A step of obtaining a raw material fired product by heat-treating a second compound containing at least one element selected and a compound containing Si in an atmosphere containing nitrogen;
The raw material fired product, a compound containing Ba, a compound containing Si, and a third compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn as necessary, and And a step of heat-treating a fourth compound containing at least one alkaline earth metal element selected from the group consisting of Sr, Ca and Mg in an atmosphere containing nitrogen to obtain a nitride phosphor. ,
The ratio of the charged molar amount of Ba to the total charged molar amount of at least one alkaline earth metal element contained in the raw material fired product in the step of obtaining the raw material fired product is the nitriding in the step of obtaining the nitride phosphor. The method for producing a nitride phosphor is characterized by being smaller than the ratio of the charged molar amount of Ba to the total charged molar amount of at least one alkaline earth metal element contained in the phosphor.

  The second aspect of the present invention is at least one selected from the group consisting of Ba, at least one alkaline earth metal element selected from the group consisting of Ca, Sr and Mg, and Eu, Ce, Tb and Mn. Nitride phosphors having a composition containing these elements, Si, and N, measured by the FSSS method with respect to the volume average particle diameter (Dm2) of the nitride phosphors by a laser diffraction scattering type particle size distribution measurement method The nitride phosphor is characterized in that the average particle diameter (N) ratio (N / Dm2) of the phosphor is 0.75 or more and 1.00 or less.

  According to one aspect of the present invention, it is possible to provide a method for producing a nitride phosphor having a large particle size and a good particle shape in a high yield, and a nitride phosphor.

1 is a volume-based particle size distribution of each nitride phosphor according to Example 1, Example 2, and Comparative Example 1. FIG. FIG. 2 is an SEM photograph of the nitride phosphor according to Example 1. FIG. 3 is an SEM photograph of the nitride phosphor according to Example 2. FIG. 4 is an SEM photograph of the nitride phosphor according to Comparative Example 1.

  Hereinafter, a method for manufacturing a nitride phosphor according to the present disclosure will be described based on embodiments. However, the embodiment described below exemplifies a nitride phosphor manufacturing method and a nitride phosphor for embodying the technical idea of the present invention, and the present invention includes the following nitride fluorescence. It is not limited to the body manufacturing method and nitride phosphor. The relationship between the color name and the chromaticity coordinates, the relationship between the wavelength range of light and the color name of monochromatic light, and the like comply with JIS Z8110.

Method for Manufacturing Nitride Phosphor A method for manufacturing a nitride phosphor according to an embodiment of the present invention includes a first method including at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca, and Mg. The raw material fired product is heat-treated in a nitrogen-containing atmosphere with a compound of the above, a second compound containing at least one element selected from the group consisting of Eu, Ce, Tb, and Mn, and a compound containing Si. And a third compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn, if necessary, a compound containing Ba, a compound containing Ba, a compound containing Si, and a compound containing Ba And a process for obtaining a nitride phosphor by heat-treating a fourth compound containing at least one alkaline earth metal element selected from the group consisting of Sr, Ca and Mg as necessary, in an atmosphere containing nitrogen. The ratio of the charged molar amount of Ba to the total charged molar amount of at least one alkaline earth metal element contained in the raw material calcined product in the step of obtaining the raw material calcined product is about the nitride phosphor. It is characterized by being smaller than the ratio of the charged molar amount of Ba to the total charged molar amount of at least one alkaline earth metal element contained in the nitride phosphor in the obtaining step.

Step of obtaining raw material fired product In the step of obtaining raw material fired product, a first compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca and Mg, Eu, Ce, Tb and A raw material fired product is obtained by heat-treating a second compound containing at least one element selected from the group consisting of Mn and a compound containing Si in an atmosphere containing nitrogen.

In the method for producing a nitride phosphor according to an embodiment of the present invention, a ratio of a charged molar amount of Ba to a total charged molar amount of the at least one alkaline earth metal element to be contained to obtain the raw material fired product ( B1) (hereinafter referred to as “Ba molar ratio (B1)”) may be contained in order to obtain a nitride phosphor having a desired composition. The ratio (B2) of the charged molar amount of Ba to the total charged molar amount (hereinafter referred to as “the ratio of charged molar amount of Ba (B2)”). The raw materials are mixed so that) becomes smaller. In addition, when Ba is not used in the step of obtaining the raw material fired product, the ratio (B1) of the charged molar amount of Ba is zero.
Since the ratio (B1) of the charged molar amount of Ba is smaller than the ratio (B2) of the molar charged amount of Ba (B2), the fired raw material is obtained with high reactivity and advanced crystal growth. Is large and the particle shape is good.
Ba tends to be scattered at a higher temperature than other elements in the raw material mixture. Moreover, the reactivity of Ba tends to be lower than that of other elements. Due to such characteristics of Ba, a nitride phosphor containing a relatively large amount of Ba obtained by a conventional manufacturing method tends to have uneven particle sizes. In such a nitride phosphor, even if the particle size is adjusted to some extent by classification or the like, the particles include secondary particles in which fine particles are aggregated, or fine particles adhere to particles having a large particle size. May be included.
In the method for producing a nitride phosphor according to an embodiment of the present invention, a raw material fired product having a composition different from the nitride phosphor to be finally obtained having a target composition is produced in advance. The ratio (B1) of the charged molar amount of Ba is smaller than the ratio (B2) of the charged molar amount of Ba. Thus, since the raw material fired product is obtained by adjusting the molar ratio of Ba, the particle size is large and the particle shape is also good. The final nitride phosphor is obtained by mixing this raw material fired product with another raw material so as to obtain the desired composition and firing again. Since the raw material fired product originally has a large particle size and a good particle shape, the nitride phosphor having the target composition also has a large particle size and a good particle shape with high yield.
In this specification, that the particle shape of the nitride phosphor is good means that the content of secondary particles in which fine particles are aggregated is small and the content of primary particles is large. Also, in this specification, that the particle shape of the nitride phosphor is good means that fine particles or the like are not attached to the surface of the particles and the surface of the particles is smooth.

In this specification, the total molar amount of the alkaline earth metal element contained in the raw material fired product and the molar amount of Ba contained in the raw material fired product are not the molar amount shown in the composition ratio of the obtained raw material fired product. The molar amount in the charged composition before obtaining the raw material fired product.
The total molar amount of the alkaline earth metal of the nitride phosphor and the molar amount of Ba of the nitride phosphor are not the molar amount shown in the composition ratio of the obtained nitride phosphor, but the target composition This means the molar amount in the charged composition of the raw material fired product and other compounds used as raw materials for obtaining the nitride phosphor.

In this specification, whether or not the particle shape is good and the content of secondary particles in which fine particles are aggregated is small is determined based on the Fischer sub-sieve sizer with respect to the volume average particle size (Dm2) by the laser diffraction scattering particle size distribution measurement method. This can be confirmed by determining the ratio (N / Dm2) of the average particle size (N: Fisher sub-sieve sizer's number) measured by (FSSS method: Fisher sub-sieve sizer).
The laser diffraction / scattering particle size distribution measurement method is a method of measuring particle size without distinguishing primary particles and secondary particles using scattered light of laser light irradiated on the particles.
On the other hand, the FSSS method is a kind of air permeation method, and is a method of measuring the particle size of primary particles using air flow resistance.
The ratio (N / Dm2) of the average particle diameter (N) of the phosphor particles measured by the FSSS method to the volume average particle diameter (Dm2) of the phosphor particles measured by the laser diffraction / scattering particle size distribution measurement method is close to 1. It can be confirmed that the content of secondary particles is small and the content of primary particles is large.
Whether or not the surface of the particles is in a smooth form can be confirmed, for example, from the appearance observed with an SEM photograph, in which fine particles or the like are not attached to the surface and the surface of the particles is in a smooth form.

In the method for producing the phosphor of the present embodiment, the ratio (B1) of the charged molar amount of Ba to the total charged molar amount of the alkaline earth metal elements to be contained in the raw material fired product is 0 or more and less than 0.3. The ratio (B2) of the charged molar amount of Ba to the total charged molar amount of the alkaline earth metal elements contained in the nitride phosphor is preferably 0.3 or more and less than 1.0.
The ratio (B1) of the charged molar amount of Ba is smaller than the ratio (B2) of the charged molar amount of Ba, and the ratio (B1) of the charged molar amount of Ba is that of the alkaline earth metal element contained in the raw material fired product. If it is 0 or more and less than 0.3 with respect to the total charged molar amount, the reactivity of the raw material fired product becomes high, crystal growth proceeds, the particle size of the finally obtained nitride phosphor becomes large, There is a tendency to improve the shape.
The ratio (B1) of the charged molar amount of Ba is more preferably 0.28 or less, still more preferably 0.26 or less, more preferably 0.26 or less, with respect to the total charged molar amount of the alkaline earth gold element contained in the raw material fired product. More preferably, it is 0.24 or less. The raw material fired product may not contain Ba element, but from the viewpoint of the stability of the crystal structure of the raw material fired product, the ratio (B1) of the charged molar amount of Ba is the alkali contained in the fired material. It is preferable that 0.01 or more is contained with respect to the total charged molar amount of earth gold elements.
The ratio (B2) of the charged molar amount of Ba is preferably 0.3 or more and 1.0 with respect to the total molar amount of the alkaline earth metals contained in the nitride phosphor from the viewpoint of the stability of the crystal structure. It is less than, More preferably, it is 0.4-0.95, More preferably, it is 0.5-0.90.

  In the step of obtaining the raw material fired product, the first compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca, and Mg becomes a skeleton that forms the crystal structure of the raw material fired product. It is a compound containing an element. In the manufacturing method of the present embodiment, the raw material fired product obtained preferably contains Sr. Moreover, the raw material fired product may not contain Ba, but from the viewpoint of the stability of the crystal structure, the ratio of the molar amount of Ba to the total molar amount of the alkaline earth gold element contained in the raw material fired product. (B1) is preferably 0.01 or more.

In the step of obtaining the raw material fired product, the second compound containing at least one element selected from the group consisting of Eu, Ce, Tb, and Mn is a compound containing an activating element that becomes a light emission center of the nitride phosphor to be obtained It is. The fired raw material obtained in the manufacturing method of the present embodiment preferably contains at least one element selected from Eu and Ce, and more preferably contains Eu. Europium (Eu) mainly has energy ranks of divalent and trivalent, but the nitride phosphor obtained in the manufacturing method of the present embodiment preferably uses Eu ²⁺ as an activation element.
In the manufacturing method of the present embodiment, the second compound containing the activation element is capable of obtaining a nitride phosphor having sufficient light emission intensity and capable of absorbing excitation light and emitting desired chromaticity. For example, the obtained nitride phosphor may contain one kind of single activation element or may contain two or more kinds of activation elements. Moreover, in the manufacturing method of this embodiment, the 2nd compound containing an activation element may use the 2nd compound containing a kind of activation element independently, and the 2nd compound containing two kinds of activation elements is used. You may use, and may use together 2 types of 2nd compounds containing a different activation element. In the manufacturing method of the present embodiment, the obtained nitride phosphor includes, for example, two kinds of activation elements, one kind is Eu, and the other activation elements are at least selected from the group consisting of Ce, Tb, and Mn. In the case of a kind of element, elements other than Eu can act as a co-activator and change the color tone of the nitride phosphor.

In the method for producing a nitride phosphor of the present embodiment, it is preferable that each compound is heat-treated so that the raw material fired product has a preparation composition represented by the following formula (I).
(Sr _q M1 _s M2 _t ) ₂ Si ₅ N ₈ (I)
In Formula (I), M1 is at least one alkaline earth metal element selected from the group consisting of Ba, Ca and Mg, and M2 is at least selected from the group consisting of Eu, Ce, Tb and Mn. Q, s, and t are 0.600 ≦ q ≦ 0.999, 0 ≦ s ≦ 0.3, 0.001 ≦ t ≦ 0.100, 0.9 <q + s + t ≦ 1.0. It is a number that satisfies

In the formula (I), twice the variable q is the molar composition ratio of Sr, and twice the variable s is the mole of at least one alkaline earth metal element selected from the group consisting of Ba, Ca and Mg. It is a composition ratio. In formula (I), M1 preferably contains Ba from the viewpoint of the stability of the crystal structure.
In the formula (I), when the variable q is a number satisfying 0.600 ≦ q ≦ 0.999 and the variable s is a number satisfying 0 ≦ s ≦ 0.3, a nitride phosphor described later is obtained. A raw material fired product having high reactivity can be obtained in the process.
In the formula (I), the variable q is a number that more preferably satisfies 0.700 ≦ q ≦ 0.980, and more preferably 0.750 ≦ q ≦ 0.950. In the formula (I), the variable s is more preferably 0.01 ≦ s ≦ 0.28, further preferably 0.02 ≦ s ≦ 0.26, and still more preferably 0.03. ≦ s ≦ 0.24.

In the formula (I), twice the variable t is a molar composition ratio of an activating element that is at least one element selected from the group consisting of Eu, Ce, Tb, and Mn. When the variable t is a number satisfying 0.001 ≦ t ≦ 0.100, sufficient emission intensity can be obtained even in the case of not adding a compound containing an element serving as an activator in the step of obtaining a nitride phosphor described later. A nitride phosphor that emits a desired chromaticity by light from an excitation light source having a predetermined emission peak wavelength can be obtained.
In the formula (I), the variable t is more preferably 0.001 ≦ t ≦ 0.090, further preferably 0.002 ≦ t ≦ 0.080, and still more preferably 0.003 ≦ t ≦ 0.070. It is a number that satisfies

The first compound is a nitride, fluoride, hydride, oxide, carbonate, chloride containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca and Mg. Thing etc. are mentioned. Nitride containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca and Mg, since a nitride phosphor having a small amount of impurities in the raw material fired material and sufficient emission intensity can be obtained. It is preferable that it is a thing, a fluoride, or a hydride, and it is more preferable that it is a nitride. By using a nitride as the first compound, it is possible to suppress the formation of a raw material fired product having a composition other than the desired composition. The compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca and Mg contains at least one element selected from the group consisting of trace amounts of Li, Na, K, B and Al. May be included.
Specifically, the first compound includes Ba ₃ N ₂ , BaF ₂ , BaH ₂ , Sr ₂ N, SrN, Sr ₃ N ₂ , SrF ₂ , SrH ₂ , Ca ₃ N ₂ , CaF ₂ , CaH ₂ , _{mg 3 N 2, MgF 2,} MgH 2, and the like.

Second Compound Examples of the second compound include nitrides, fluorides, hydrides, oxides, carbonates, and chlorides containing at least one element selected from the group consisting of Eu, Ce, Tb, and Mn. It is done. Nitride and fluoride containing at least one element selected from the group consisting of Eu, Ce, Tb, and Mn because a nitride phosphor having a small amount of impurities in the raw material fired material and sufficient light emission intensity can be obtained. Or it is preferable that it is a hydride, and it is more preferable that it is a nitride. By using a nitride as the second compound, it is possible to suppress the formation of a raw material fired product having a composition other than the desired composition.
Specific examples of the second compound include EuN, EuF ₃ , EuH ₃ , CeN, CeF ₃ , CeH ₃ , TbN, TbF ₃ , TbH ₃ , MnN ₂ , MnN ₅ and MnF ₂ .

Compound containing Si The compound containing Si may be a metal containing substantially only Si, and a part of Si is selected from the group consisting of Ge, Sn, Ti, Zr, Hf, B, Al, Ga and In. It may be an alloy substituted with at least one selected metal. Examples of the compound containing Si include nitrides, oxides, imide compounds, and amide compounds. Since a nitride phosphor having a sufficient light emission intensity is obtained with few impurities in the raw material fired product, a nitride, an imide compound or an amide compound is preferable, and a nitride is more preferable. By using nitride as a raw material, it is possible to suppress the formation of a raw material fired product having a composition other than the desired composition.
Specific examples of the compound containing Si include Si ₃ N ₄ , SiO ₂ , Si (NH) ₂ , Si ₂ N ₂ NH, and Si (NH ₂ ) ₄ .

  Each of the raw materials containing the first compound, the second compound, and the compound containing Si has an average particle size of about 0.1 μm to 15 μm, more preferably about 0.1 μm to 10 μm. However, it is preferable from the viewpoints of reactivity with other raw materials, particle size control at the time of heat treatment and after heat treatment, etc., and the particle size of each raw material exceeding the above range can be achieved by grinding each raw material.

  Each raw material is preferably purified. This is because by using each of the purified raw materials, a purification process is not required, so that the manufacturing process can be simplified and an inexpensive phosphor can be provided.

Flux Raw materials are mixed to obtain a raw material mixture. The raw material mixture may contain a flux. Since the raw material mixture contains a flux, the reaction between the raw materials is further promoted, and further, the solid phase reaction proceeds more uniformly, so that the particle size is large, and the raw material firing is used to obtain a phosphor having superior light emission characteristics. Can be manufactured. This is considered to be because, for example, the temperature of the heat treatment for obtaining the raw material fired product is 1300 ° C. or higher and 2100 ° C. or lower, and this temperature is substantially the same as the liquid phase formation temperature of halide such as flux. As the halide, rare earth metals, alkaline earth metals, alkali metal chlorides, fluorides, and the like can be used. As the flux, the flux can be added as a part of the raw material of the nitride phosphor by adjusting the composition of the raw material of the raw material to be obtained to obtain the element ratio of the cation contained in the flux. After adding each raw material so that it may become a composition of a thing, a flux can also be added in the form added further.

When the raw material mixture contains a flux, the flux component promotes reactivity, but if it is too much, it leads to a decrease in light emission intensity. Therefore, the content is preferably 10% by mass or less in the raw material mixture, for example, 5% by mass. % Or less is more preferable.
Even when fluoride is used as the flux, almost no fluorine element remains in the fired product by heat treatment at 1300 ° C. or more and 2100 ° C. or less, and even when flux containing fluorine element is used after heat treatment The fluorine element in the obtained fired product is usually 0.1% by mass or less, preferably 0.08% by mass or less.

  In the case of obtaining a raw material fired product having the charged composition represented by the formula (I), as an example of the target composition, the molar amount of Sr, the molar amount of M1, the molar amount of M2, And the molar amount of N is Sr: M1: M2: Si: N = (1.200 to 1.998) :( 0 to 0.600) :( 0.002 to 0.200): 5: Each raw material is preferably weighed so as to satisfy a molar ratio of 8.

Raw material mixture The weighed raw materials are mixed by a wet or dry method using a mixer to obtain a raw material mixture. The mixer can be pulverized using a pulverizer such as a vibration mill, a roll mill, a jet mill or the like in addition to a ball mill that is usually used industrially to increase the specific surface area. In addition, in order to keep the specific surface area of the powder within a certain range, classification is performed using an industrially commonly used settling tank, a hydrocyclone, a wet separator such as a centrifugal separator, or a dry classifier such as a cyclone or an air separator. You can also

The raw material mixture is placed in a crucible or boat made of carbon such as graphite, boron nitride (BN), alumina (Al ₂ O ₃ ), tungsten (W), molybdenum (Mo), etc. and heat-treated in the furnace. A fired product can be obtained.

Heat Treatment In the method for producing a nitride phosphor according to an embodiment of the present invention, a raw material fired product is obtained by heat treatment in an atmosphere containing nitrogen. The atmosphere for heat treatment may be an atmosphere containing nitrogen. The atmosphere containing nitrogen preferably contains 70% by volume or more of nitrogen gas, more preferably 80% by volume or more, and still more preferably 90% by volume or more. The atmosphere containing nitrogen is preferably a reducing atmosphere. The reducing atmosphere is more preferably an atmosphere containing reducing hydrogen gas. The atmosphere containing nitrogen and reducing hydrogen gas preferably contains 1% by volume or more, more preferably 5% by volume or more, and even more preferably 10% by volume or more of hydrogen gas.
The manufacturing method of this embodiment can manufacture a raw material fired product for obtaining a desired nitride phosphor by heat-treating the raw material mixture in an atmosphere containing nitrogen. When the atmosphere containing nitrogen is an atmosphere containing nitrogen gas and reducing hydrogen gas, a fired raw material for obtaining a nitride phosphor with higher emission intensity can be obtained. This is because, for example, when the activator is Eu, the proportion of divalent Eu contributing to light emission increases in the raw material fired product. Bivalent Eu is easily oxidized to trivalent Eu. However, since trivalent Eu is reduced to divalent Eu by firing in a reducing atmosphere containing hydrogen and nitrogen and having a high reducing power, divalent Eu is divalent. The proportion of Eu is increased, and a raw material fired product for forming a nitride phosphor having high emission intensity is obtained.

  The heat treatment temperature for obtaining the raw material fired product is preferably 1300 ° C. or higher and 2100 ° C. or lower, more preferably 1500 ° C. or higher and 2000 ° C. or lower, and further preferably 1600 ° C. or higher and 1950 ° C. or lower. If the heat treatment temperature is not less than 1300 ° C. and not more than 2100 ° C., raw material firing for obtaining a phosphor having a desired composition, a stable crystal structure, and sufficient emission intensity is suppressed by heat. A thing is obtained.

  The heat treatment may be performed a plurality of times in two or more stages. For example, when performing a two-stage heat treatment, it is preferable to perform the first heat treatment at 1000 ° C. or more and less than 1500 ° C., and perform the second firing at a temperature of 1500 ° C. or more and 2100 ° C. or less. This is because if the first heat treatment temperature is 1000 ° C. or higher and lower than 1500 ° C., it is easy to obtain a raw material fired product having a target composition. A raw material for obtaining a nitride phosphor having a stable crystal structure and sufficient emission intensity, with the decomposition of the obtained raw material fired when the second heat treatment temperature is 1500 ° C. or higher and 2100 ° C. or lower. This is because it is easy to obtain a fired product.

  The pressure of the atmosphere containing nitrogen is preferably a gauge pressure and a pressurized atmosphere of 0.1 MPa to 200 MPa. The fired raw material obtained by the heat treatment is easily decomposed as the heat treatment temperature becomes higher. However, by using a pressurized atmosphere, the decomposition of the crystal structure can be suppressed and the decrease in the emission intensity can be suppressed. . The pressure of the heat treatment atmosphere is a gauge pressure, more preferably 0.1 MPa or more and 100 MPa or less, further preferably 0.5 MPa or more and 10 MPa or less, and further preferably 1.0 MPa or less from the viewpoint of ease of production. It is.

  The heat treatment time can be appropriately selected according to the heat treatment temperature and the pressure of the atmosphere during the heat treatment, and is preferably 0.5 hours or more and 20 hours or less, and even when performing multi-step heat treatment, The heat treatment time is preferably 0.5 hours or more and 20 hours or less. When the heat treatment time is 0.5 hours or more and 20 hours or less, decomposition of the obtained fired product is suppressed, and a fired product for obtaining a phosphor having a stable crystal structure and sufficient emission intensity is obtained. In addition, the production cost can be reduced and the manufacturing time can be made relatively short. The heat treatment time is more preferably 1 hour or more and 10 hours or less, and further preferably 1.5 hours or more and 9 hours or less.

Post-treatment after heat treatment In the production method of the present embodiment, after the heat treatment, post-treatment such as pulverization, wet dispersion, solid-liquid separation, drying, and classification may be performed on the obtained fired raw material. Solid-liquid separation can be performed by industrially used methods such as filtration, suction filtration, pressure filtration, centrifugation, and decantation. Drying can be performed by industrially used apparatuses such as a vacuum dryer, a hot-air heating dryer, a conical dryer, and a rotary evaporator. Classification can be performed by industrially commonly used methods such as sedimentation classification, mechanical classification, hydraulic classification, centrifugal classification and the like, and sieving classification.

  The raw material fired product obtained by the production method of the present embodiment preferably has a structure with high crystallinity at least in part. For example, since a glass body (amorphous) has an irregular structure and low crystallinity, if the reaction conditions in the production process cannot be controlled so as to be strictly uniform, a light emitting device using a nitride phosphor can be used. There is a tendency to cause chromaticity unevenness and the like. The raw material fired product obtained by the production method of the present embodiment preferably has a structure with high crystallinity at least in part. A raw material fired product having a structure with high crystallinity at least in part tends to be easily manufactured and processed.

In the production method of the present embodiment, the fired raw material preferably has a volume average particle size (Dm1) of the fired raw material of 5.0 μm or more and 20.0 μm or less as measured by a laser diffraction scattering particle size distribution measurement method. The volume average particle diameter (Dm1) is more preferably from 5.5 μm to 19.0 μm, still more preferably from 6.0 μm to 18.0 μm, still more preferably from 6.5 μm to 17.0 μm. Since the volume average particle size (Dm1) of the raw material fired product is within the above range, the obtained raw material fired product has high reactivity in the subsequent step of obtaining the nitride phosphor. The product phosphor can be obtained, and the nitride phosphor having a uniform particle shape can be obtained.
The raw material fired product has an average particle size (N1) measured by the FSSS method of preferably 4.0 μm or more, more preferably 4.5 μm or more, still more preferably 5.0 μm or more, and preferably 20.0 μm. It is as follows.
In the production method of the present embodiment, the raw material fired product whose volume average diameter is measured by the laser diffraction scattering particle size distribution measurement method is coarse particles having a particle diameter exceeding 50.0 μm, for example, by classification or the like. The fine particle less than 0 micrometer may be removed. Even when such coarse particles and fine particles are removed, the nitride phosphor obtained by the manufacturing method of the present embodiment has a large crystal growth and a high content of primary particles. And a nitride phosphor having a good particle shape can be obtained in a high yield.

Step of obtaining nitride phosphor The method for producing a nitride phosphor according to an embodiment of the present invention includes the raw material fired product, a compound containing Ba, a compound containing Si, and, if necessary, Eu, Ce, Tb. And a third compound containing at least one element selected from the group consisting of Mn and, if necessary, a fourth compound containing at least one alkaline earth metal selected from the group consisting of Sr, Ca and Mg Are subjected to a heat treatment in an atmosphere containing nitrogen to obtain a nitride phosphor.
The ratio (B1) of the charged molar amount of Ba to the total charged molar amount of the alkaline earth metal element to be contained in the raw material fired product is the same as that of the raw material fired product in order to obtain the desired composition of the nitride phosphor. It is smaller than the ratio (B2) of the charged molar amount of Ba to the total molar amount of alkaline earth metal elements to be contained in the compound mixture. Therefore, the raw material fired product and the compound containing at least Ba are heat-treated in an atmosphere containing nitrogen, so that the highly reactive raw material fired product has insufficient Ba for the composition of the target nitride phosphor. As well as promoting the crystal growth, the particle size of the resulting nitride phosphor can be increased and the particle shape can be improved.

Compound containing Ba In the manufacturing method of this embodiment, the compound containing Ba to be heat-treated with the raw material fired product is the same as the compound containing Ba used in the step of obtaining the raw material fired product. Examples include hydrides, oxides, carbonates, and chlorides. Since a nitride phosphor having a small amount of impurities and sufficient emission intensity can be obtained, a nitride, fluoride or hydride containing Ba is preferable, and a nitride is more preferable. By using a nitride as the compound containing Ba, it is possible to suppress the formation of a fired raw material other than the desired composition. Specific examples of the compound containing Ba include Ba ₃ N ₂ , BaF ₂ and BaH ₂ .

Third compound, fourth compound, compound containing Si The manufacturing method of the present embodiment includes a compound containing Si in a step of obtaining a nitride phosphor by heat-treating a fired material and a compound containing Ba together, A third compound can be used if necessary, and a fourth compound can be used if necessary.
The compound containing Si is preferably the same as the compound containing Si used in the step of obtaining the raw material fired product.
The third compound is preferably the same as the second compound used in the step of obtaining the raw material fired product.
As the fourth compound, it is preferable to use the same compound as the first compound excluding the compound containing Ba used in the step of obtaining the raw material fired product.

  The compound containing Ba, the compound containing Si, the third compound, and the fourth compound each preferably have an average particle size of about 0.1 μm to 15 μm, more preferably about 0.1 μm to 10 μm. In addition, it is preferable to use purified raw materials for the compound containing Ba, the compound containing Si, the third compound, and the fourth compound. Further, the mixture obtained by mixing the raw material fired product and the compound containing at least Ba may contain a flux. As the flux, the flux used in the step of obtaining the raw material fired product can be used.

  The nitride phosphor obtained by the production method of the present embodiment preferably has a composition represented by the formula (II) described later.

  In the manufacturing method of the present embodiment, when a nitride phosphor is obtained by mixing a raw material fired product and a compound containing at least Ba, as an example of a target composition, a raw material fired product and a compound containing at least Ba If necessary, the molar amount of Ba, the molar amount of Sr, the molar amount of M3, the molar amount of M2, the molar amount of Si, and the molar amount of N in the mixture of other compounds are Ba: Sr: M3: M2: The molar ratio of Si: N = (0.600 to 1.998) :( 0.200 to 1.400) :( 0 to 1.200) :( 0.002 to 0.200): 5: 8 is satisfied. Thus, it is preferable to weigh the raw material fired product, the compound containing at least Ba, and other compounds as necessary.

Mixing / Heat Treatment It is preferable to use the apparatus used in the step of obtaining the raw material fired product for mixing the raw material fired product and the compound containing at least Ba.
The heat treatment of the mixture of the raw material fired product and the compound containing at least Ba is preferably performed according to the nitrogen-containing atmosphere, the heat treatment temperature, and the heat treatment conditions in the step of obtaining the raw material fired product.

Post-treatment after heat treatment In the method for producing a nitride phosphor according to the present embodiment, after the heat treatment, post-treatment such as wet dispersion, solid-liquid separation, drying, and classification is performed on the obtained nitride phosphor. Also good. Solid-liquid separation can be performed by industrially used methods such as filtration, suction filtration, pressure filtration, centrifugation, and decantation. Drying can be performed by industrially used apparatuses such as a vacuum dryer, a hot-air heating dryer, a conical dryer, and a rotary evaporator. Classification can be performed by industrially commonly used methods such as sedimentation classification, mechanical classification, hydraulic classification, centrifugal classification and the like, and sieving classification.

Nitride phosphor The nitride phosphor according to an embodiment of the present invention includes Ba, at least one alkaline earth metal element selected from the group consisting of Ca, Sr, and Mg, Eu, Ce, Tb, and Mn. A nitride phosphor having a composition containing at least one element selected from the group consisting of Si, N, and a volume average particle size of the nitride phosphor by a laser diffraction scattering particle size distribution measurement method ( The ratio (N / Dm2) of the average particle diameter (N) of the nitride phosphor measured by the FSSS method with respect to Dm2) is 0.75 or more and 1.00 or less.
The nitride phosphor of the present embodiment is preferably manufactured by the method for manufacturing a nitride phosphor according to one embodiment of the present invention.

The nitride phosphor according to one embodiment of the present invention has a ratio (N / Dm2) of the average particle diameter (N) measured by the FSSS method to the volume average particle diameter (Dm2) by the laser diffraction scattering particle size distribution measurement method. 0.75 or more and 1.00 or less, preferably 0.76 or more and 0.99 or less, and more preferably 0.77 or more and 0.98 or less. By being within the above range, it can be confirmed that the content of secondary particles is small, the content of primary particles is large, and the particle shape is good. That is, if the N / Dm2 ratio is a numerical value close to 1, the difference between the numerical values of the average particle diameters of the phosphor particles obtained by both the laser diffraction scattering particle size distribution measurement method and the FSSS method is small. It can be seen that the content of secondary particles in which fine particles are aggregated is small and the content of primary particles is large. When the N / Dm2 ratio of the phosphor particles is less than 0.75, it can be inferred that secondary particles aggregated together with the primary particles are mixed, and the content of secondary particles is large.
The nitride phosphor of the present embodiment is preferably one obtained by removing coarse particles having a particle diameter of, for example, more than 50.0 μm or fine particles having a particle diameter of, for example, less than 1.0 μm by classification or the like.

  The nitride phosphor of this embodiment preferably has an average particle size (N) measured by the FSSS method of 7.0 μm or more and 20.0 μm or less, more preferably 7.5 μm or more and 19.0 μm or less, and further Preferably they are 8.0 micrometers or more and 18.0 micrometers or less. When the average particle size (N) is within the above range, the particle shape tends to be good.

  The nitride phosphor of the present embodiment preferably has a volume average particle size (Dm2) of 8.0 μm or more and 20.0 μm or less, more preferably 9.0 μm or more and 19 or less, as measured by a laser diffraction / scattering particle size distribution measurement method. It is 0.0 μm or less, more preferably 10.0 μm or more and 18.0 μm or less, and still more preferably 10.5 μm or more and 18.0 μm or less. When the volume average particle diameter (Dm2) is within the above range, the light emission intensity is sufficient.

The nitride phosphor preferably has a good particle shape and a uniform particle size. The nitride phosphor of the present embodiment has a narrow half-value width of the particle size distribution as long as the standard deviation of the volume-based particle size distribution of the phosphor particles measured by, for example, a laser diffraction / scattering particle size distribution measuring method is small. It can be seen that the spectral shape of the distribution is sharper and the particle size is aligned.
In the nitride phosphor of the present embodiment, the standard deviation (σlog) in the volume-based particle size distribution measured by the laser diffraction / scattering particle size distribution measurement method is preferably 0.30 or less, more preferably 0.29 or less. .

The nitride phosphor of the present embodiment preferably has a composition represented by the following formula (II).
_{(Ba v Sr w M3 x M2} y) 2 Si 5 N 8-z (II)
In formula (II), M3 is at least one alkaline earth metal element selected from Ca and Mg, and M2 is at least one element selected from the group consisting of Eu, Ce, Tb and Mn. , V, w, x, y, z are 0.300 ≦ v ≦ 0.899, 0.100 ≦ w ≦ 0.700, 0 ≦ x ≦ 0.6, 0.001 ≦ y ≦ 0.100, It is a number satisfying 0.9 <v + w + x ≦ 1.0 and 0 ≦ z ≦ 0.5.
The nitride phosphor having the composition represented by the formula (II) may contain oxygen (O) due to surface oxidation, and part of N may be replaced by oxygen (O). The content of oxygen (O) in the nitride phosphor is preferably 0.10 mol or less, more preferably 0.08 mol or less, and still more preferably 0.07 mol or less in terms of composition ratio.

Hereinafter, the nitride phosphor having the composition represented by the formula (II) is also referred to as “nitride phosphor (II)” for convenience.
In the above formula (II), twice the variable v is the molar composition ratio of Ba in the nitride phosphor (II). From the viewpoint of the stability of the crystal structure, the variable v is more preferably a number satisfying 0.400 ≦ v ≦ 0.890, and still more preferably a number satisfying 0.500 ≦ v ≦ 0.880.
In the formula (II), twice the variable w is the molar composition ratio of Sr in the nitride phosphor (II). From the viewpoint of the stability of the crystal structure of the fired raw material and the reactivity with the compound containing Ba, the variable w is preferably 0.120 ≦ w ≦ 0.650, more preferably 0.150 ≦ w ≦ 0. It is a number satisfying 600.

In the formula (II), twice the variable y is the activation amount of the activation element which is at least one element selected from the group consisting of Eu, Ce, Tb and Mn in the nitride phosphor (II). When the variable y is a number satisfying 0.001 ≦ y ≦ 0.100, the nitride fluorescence has sufficient emission intensity and emits desired chromaticity by light from an excitation light source having a predetermined emission peak wavelength. You can get a body.
In the formula (II), the variable y is more preferably 0.001 ≦ y ≦ 0.090, further preferably 0.002 ≦ y ≦ 0.080, and still more preferably 0.003 ≦ y ≦ 0.070. It is a number that satisfies

  The nitride phosphor of this embodiment is activated by at least one element selected from the group consisting of Eu, Ce, Tb, and Mn, preferably europium (Eu), and has an emission peak wavelength in the ultraviolet to visible light region. Absorbs light and emits red light. The nitride phosphor absorbs light having an emission peak wavelength in a range from 400 nm to 570 nm, which is an ultraviolet to visible light region, and emits light having an emission peak wavelength in a wavelength range of 570 nm to 670 nm. The nitride phosphor of this embodiment preferably has an emission peak wavelength in the wavelength range of 580 nm to 650 nm, and more preferably has an emission peak wavelength in the wavelength range of 585 nm to 630 nm. The half width of the emission spectrum of the nitride phosphor is not particularly limited, but is, for example, 95 nm or less, preferably 92 nm or less, and more preferably 90 nm or less. The one with a smaller half-value width of the emission peak is preferably used as a nitride phosphor with high color purity.

  The nitride phosphor of this embodiment preferably has a structure with high crystallinity at least in part. For example, a glass body (amorphous) has an irregular structure and low crystallinity. Therefore, if the reaction conditions in the production process cannot be controlled so as to be strictly uniform, chromaticity unevenness tends to occur. The nitride phosphor of this embodiment preferably has a structure with high crystallinity at least in part. A nitride phosphor having a structure with high crystallinity at least in part tends to be easily manufactured and processed. In addition, since the nitride phosphor having a highly crystalline structure at least in part can be easily dispersed uniformly in the resin, a fluorescent member containing the resin can be easily formed. Specifically, the nitride phosphor preferably has a structure in which the proportion of the crystalline phase having light-emitting properties is, for example, 50% by mass or more, more preferably 80% by mass or more. If the nitride phosphor has a crystal phase of 50% by mass or more, light emission with a practically strong intensity can be obtained.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

Production of raw material fired material A raw material fired product having a composition containing Ba, Sr, Eu, Si and N was produced. Specifically, as the fired product having the composition represented by the formula (I), Sr, M1 was Ba, and M2 was Eu. As the first compound, Ba ₃ N ₂ and SrN _u (u is equivalent to 2/3, a mixture of Sr ₂ N and SrN) were used. EuN was used as the second compound. Si ₃ N ₄ was used as a compound containing Si.
Nitrogen atmosphere substantially containing 100% by volume of nitrogen so that the charge composition is such that the molar ratio of Sr: Ba: Eu: Si is 1.74: 0.22: 0.04: 5.00 Were weighed and mixed in a glove box to obtain a raw material mixture. The ratio (B1) of the charged molar amount of Ba to the total molar amount of alkaline earth metal elements (Sr and Ba) is shown in Table 1.
The obtained raw material mixture was filled in a crucible, and the gas pressure was 0.92 MPa (absolute pressure was 1.02 MPa) in a nitrogen atmosphere substantially containing 100% by volume of nitrogen, and heat treatment was performed at 1800 ° C. for 5 hours. A raw material fired product was obtained. Since the obtained raw material fired product was sintered among particles, it was pulverized, settled and classified, and sieved and classified with an opening of about 15 μm to obtain a powdery raw material fired product 1. The average particle diameter (Dm1) by a laser diffraction scattering type particle size distribution measurement method described later was 8.5 μm, and the standard deviation (σlog) in the volume-based particle size distribution was 0.384. Moreover, the average particle diameter (N1) measured by FSSS method mentioned later was 5.7 micrometers.

Example 1
Using the obtained raw material fired product 1, Ba ₃ N ₂ was further used as a compound containing Ba, Si ₃ N ₄ was used as a compound containing Si, and EuN was used as a third compound as necessary.
The raw material fired product 1 and each compound were substantially 100 volumes of nitrogen so that the molar ratio of Ba: Sr: Eu: Si was 1.800: 0.400: 0.040: 5.000. Weighed and mixed in a glove box with a nitrogen atmosphere containing% to obtain a mixture. Table 1 shows the ratio (B2) of the charged molar amount of Ba to the total molar amount of alkaline earth metal elements (Sr and Ba) in the charged composition. Similarly, in the following examples and comparative examples, the ratio (B2) of the charged molar amount of Ba for obtaining a nitride phosphor having a target composition is shown in Table 1.
The obtained mixture was filled in a crucible, and the gas pressure was 0.92 MPa (absolute pressure was 1.02 MPa) in a nitrogen atmosphere substantially containing 100% by volume of nitrogen, and heat treatment was performed at 1800 ° C. for 5 hours. A nitride phosphor was obtained. Since the obtained nitride phosphor may be sintered with each other, the nitride phosphor powder 1 is obtained by wet dispersion, sedimentation classification, dehydration, drying, and sieving classification with an opening of about 15 μm. Obtained.

Example 2
Using the raw material fired product 1, the raw material fired product and each compound were prepared so that the molar ratio of Ba: Sr: Eu: Si was 1.876: 0.335: 0.040: 5.000. A nitride phosphor powder 2 was obtained in the same manner as in Example 1 except that it was used.

Example 3
Using the raw material fired product 1, the raw material fired product and each compound were prepared so that the molar ratio of Ba: Sr: Eu: Si was 1.250: 0.710: 0.040: 5.000 as the charge composition. Using, a nitride phosphor powder 3 was obtained.

Example 4
Using the raw material fired product 1, the raw material fired product and each compound were prepared so that the molar ratio of Ba: Sr: Eu: Si was 1.358: 0.603: 0.040: 5.000 as the charge composition. Using, a nitride phosphor powder 4 was obtained.

Comparative Example 1
Ba ₃ N ₂ , SrN _u (equivalent to 2/3, a mixture of Sr ₂ N and SrN), EuN and the same composition as in Example 1 without using a raw material fired product A nitride phosphor powder 5 was obtained in the same manner as in Example 1 except that Si ₃ N ₄ was used.

Comparative Example 2
Ba ₃ N ₂ , SrN _u (equivalent to 2/3, a mixture of Sr ₂ N and SrN), EuN, and the same composition as in Example 3 without using a raw material fired product A nitride phosphor powder 6 was obtained in the same manner as in Example 1 except that Si ₃ N ₄ was used.

Evaluation Each of the nitride phosphors was evaluated by the following method.

Volume average particle diameter (Dm1, Dm2)
Volume-based accumulation of raw material fired products and nitride phosphors of each example and comparative example using a laser diffraction / scattering particle size distribution analyzer (product name: MASTER SUZER 2000, manufactured by MALVERN) Average particle diameters (Dm1, Dm2), which are median diameters with a frequency of 50%, were measured. In addition, the standard deviation (σlog) in the volume-based particle size distribution was measured. The results of each example and comparative example are shown in Table 1. FIG. 1 shows the volume-based particle size distributions of the nitride fluorescence according to Examples 1 and 2 and the nitride phosphor according to Comparative Example 1.

Average particle size by FSSS method (N)
The raw material fired product and the nitride phosphors of the respective examples and comparative examples were subjected to FS by the FSSS method which is one of the air permeation methods. S. S. No. (Fisher Sub-Sieve Sizer's No., also referred to as “FSSS average particle size (N)”). Specifically, in an environment of an air temperature of 25 ° C. and a relative humidity of 70% RH, a sample of 1 cm ³ minutes is weighed and packed in a special tubular container, and then a constant pressure of dry air is circulated so that the specific surface area is measured from the atmospheric pressure. Was measured and converted into an FSSS average particle size (N). The results of each example and comparative example are shown in Table 1.

Composition analysis The nitride phosphors of the examples and comparative examples were subjected to composition analysis by ICP emission analysis using an inductively coupled plasma emission analyzer (manufactured by Perkin Elmer), and each element contained. The amount (composition ratio) was determined. The results are shown in Table 2. The numerical values of the compositions shown in Table 2 are values calculated from the analysis results with a Si composition ratio of 5. In Table 2, the preparation composition (molar amount) of the raw material fired product and the preparation composition (molar amount) of the nitride phosphors of the examples and comparative examples are shown together with the analytical values.

SEM Image Using a scanning electron microscope (SEM), SEM photographs of the nitride phosphors according to Examples 1 and 2 and the nitride phosphor according to Comparative Example 1 were obtained. 2 is an SEM photograph of the nitride phosphor according to Example 1, FIG. 3 is an SEM photograph of the nitride phosphor according to Example 2, and FIG. 4 is an SEM of the nitride phosphor according to Comparative Example 1. It is a photograph.

As shown in Table 1, the nitride phosphors of Examples 1 to 4 have an N / Dm2 ratio of 0.75 or more. From this result, it can be seen that the nitride phosphors of Examples 1 to 4 have low secondary particle abundance, high primary particle abundance, and good particle shape.
When the nitride phosphor of Example 1 manufactured with the same charge composition is compared with the nitride phosphor of Comparative Example 1, both the FSSS average particle size (N) and the volume average particle size (Dm2) are the nitride of Example 1. The phosphor is larger than the nitride phosphor of Comparative Example 1. Further, even when the nitride phosphor of Example 3 manufactured with the same charge composition is compared with the nitride phosphor of Comparative Example 2, the FSSS average particle size (N) is equal to that of the nitride phosphor of Example 3. However, it is larger than the nitride phosphor of Comparative Example 2.
The yields of the nitride phosphors of Examples 1 and 2 are higher than the yield of the nitride phosphor of Comparative Example 1, and the yields of the nitride phosphors of Examples 3 and 4 are Comparative Example 2. It is higher than the yield of the nitride phosphor.
From this result, the nitride phosphor of Example 1 has a high yield and a small particle size because the ratio (B1) of the charged molar amount of Ba is smaller than the ratio (B2) of the charged molar amount of Ba. It was confirmed that a nitride phosphor having a large and good particle shape was obtained.

  As shown in Table 2, the nitride phosphors of Examples 1 to 4 using a raw material fired product and the nitride phosphors of Comparative Examples 1 to 2 using no raw material fired product have a composition ratio of each element. Although there is some variation, a nitride phosphor having an almost intended composition has been obtained.

  As shown in FIG. 1, with respect to the particle size distribution of the nitride phosphors of Examples 1 and 2, the average particle size at which the volume frequency peaks is larger than that of the nitride phosphor of Comparative Example 1, and the particle size distribution It was confirmed that the full width at half maximum was narrow.

As shown in the SEM photographs of FIGS. 2 and 3, the nitride phosphor of Example 1 and the nitride phosphor of Example 2 do not contain secondary particles, and almost all are primary particles. Further, it can be confirmed that particles having a rough surface are not included, the surface is smooth, the particle shape is good, and the particle size is uniform.
On the other hand, as shown in the SEM photograph of FIG. 4, the nitride phosphor of Comparative Example 1 has irregular particle sizes, and includes secondary particles in which fine particles are aggregated and particles having a rough surface. The particle shape was not good.

  The nitride phosphor obtained by the manufacturing method of the present embodiment is combined with a light emitting element and can be used in a wide range of fields such as general lighting, in-vehicle lighting, a display, a backlight for liquid crystal, a traffic light, and an illumination switch. .

Claims (9)

A first compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca and Mg; and at least one element selected from the group consisting of Eu, Ce, Tb and Mn. A step of heat-treating a second compound and a compound containing Si in an atmosphere containing nitrogen to obtain a raw material fired product;
The raw material fired product, a compound containing Ba, a compound containing Si, and a third compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn as necessary, and And a step of heat-treating a fourth compound containing at least one alkaline earth metal element selected from the group consisting of Sr, Ca and Mg in an atmosphere containing nitrogen to obtain a nitride phosphor. ,
In the step of obtaining the nitride phosphor, the ratio of the charged molar amount of Ba to the total charged molar amount of the at least one alkaline earth metal element to be contained in the raw material fired product in the step of obtaining the raw material fired product is obtained. A method for producing a nitride phosphor, characterized by being smaller than a ratio of a charged molar amount of Ba to a total charged molar amount of the at least one alkaline earth metal element contained in the nitride fluorescent material. The ratio (B1) of the charged molar amount of Ba to the total charged molar amount of the at least one alkaline earth metal element contained in the raw material fired product is 0 or more and less than 0.3.
The ratio (B2) of the molar amount of Ba in the total charged molar amount of the at least one alkaline earth metal element to be contained in the nitride phosphor is 0.3 or more and less than 1.0. A method for producing a nitride phosphor according to claim 1. The manufacturing method of the nitride fluorescent substance of Claim 1 or 2 which heat-processes each compound so that the said raw material baked material may have a preparation composition represented by following formula (I).
(Sr _q M1 _s M2 _t ) ₂ Si ₅ N ₈ (I)
(In formula (I), M1 is at least one alkaline earth metal element selected from the group consisting of Ba, Ca and Mg, and M2 is selected from the group consisting of Eu, Ce, Tb and Mn. Q, s, t are 0.600 ≦ q ≦ 0.999, 0 ≦ s ≦ 0.3, 0.001 ≦ t ≦ 0.100, 0.9 <q + s + t ≦ 1. It is a number that satisfies 0.) The manufacturing method of the nitride fluorescent substance as described in any one of Claim 1 to 3 with which the said nitride fluorescent substance has a composition represented by following formula (II).
_{(Ba v Sr w M3 x M2} y) 2 Si 5 N 8-z (II)
(In Formula (II), M3 is at least one alkaline earth metal element selected from Ca and Mg, and M2 is at least one element selected from the group consisting of Eu, Ce, Tb and Mn. Yes, v, w, x, y, z are 0.300 ≦ v ≦ 0.899, 0.100 ≦ w ≦ 0.700, 0 ≦ x ≦ 0.6, 0.001 ≦ y ≦ 0.100 0.9 <v + w + x ≦ 1.0 and 0 ≦ z ≦ 0.5.)   The nitride fluorescence according to any one of claims 1 to 4, wherein a volume average particle diameter (Dm1) of the fired raw material by a laser diffraction / scattering particle size distribution measurement method is 5.0 µm or more and 20.0 µm or less. Body manufacturing method. Ba, at least one alkaline earth metal element selected from the group consisting of Ca, Sr and Mg, at least one element selected from the group consisting of Eu, Ce, Tb and Mn, Si and N; A nitride phosphor having a composition comprising:
The ratio (N / Dm2) of the average particle diameter (N) of the nitride phosphor by the FSSS method to the volume average particle diameter (Dm2) of the nitride phosphor by the laser diffraction / scattering particle size distribution measurement method is 0.75 or more and 1 A nitride phosphor characterized by being 0.000 or less. The nitride phosphor according to claim 6, wherein the nitride phosphor has a composition represented by the following formula (II).
_{(Ba v Sr w M3 x M2} y) 2 Si 5 N 8-z (II)
(In Formula (II), M3 is at least one alkaline earth metal element selected from Ca and Mg, and M2 is at least one element selected from the group consisting of Eu, Ce, Tb and Mn. Yes, v, w, x, y, z are 0.300 ≦ v ≦ 0.899, 0.100 ≦ w ≦ 0.700, 0 ≦ x ≦ 0.6, 0.001 ≦ y ≦ 0.100 0.9 <v + w + x ≦ 1.0 and 0 ≦ z ≦ 0.5.)   The nitride phosphor according to claim 6 or 7, wherein an average particle diameter (N) of the nitride phosphor measured by an FSSS method is 7.0 µm or more and 20.0 µm or less.   9. The nitride phosphor according to claim 6, wherein a volume average particle diameter (Dm2) of the nitride phosphor is 8.0 μm or more and 20.0 μm or less.