JP6763422B2 - Manufacturing method of wavelength conversion member and wavelength conversion member - Google Patents

Description

The present invention is a method for manufacturing a wavelength conversion member that converts the wavelength of light emitted from a light emitting diode (hereinafter, also referred to as "LED") or a laser diode (hereinafter, also referred to as "LD"). And the diode conversion member.

A light emitting device that uses an LED or LD light emitting element is a light source with high conversion efficiency, consumes less power, has a long life, and can be miniaturized in size. Therefore, it can be used as a light source in place of incandescent lamps and fluorescent lamps. It's being used. In such a light emitting device, a light emitting element which is a light source and a wavelength conversion member which absorbs a part of light emitted from the light emitting element and converts it into different wavelengths are housed in a package. Light emitting devices using LEDs and LDs are used in a wide range of fields such as light emitting devices for automobiles and indoor lighting, backlight light sources for liquid crystal display devices, illuminations, and light source devices for projectors. Among them, a light emitting device that emits a mixed color light by combining a light emitting element that emits blue light and a phosphor that emits yellow light or the like is widely used.

The phosphors used in such a light emitting device are (Y, Gd, Tb, Lu) ₃ (Al, Ga) ₅ O ₁₂ : rare earth aluminate phosphor represented by Ce, (Sr, Ca, Ba). ₂ SiO ₄ : Inorganic phosphors such as a silicate phosphor represented by Eu and a Ca-α-sialon phosphor are known. These phosphors are dispersed in the resin, and the resin containing the phosphor is cured in the package to form a wavelength conversion member. As the wavelength conversion member, for example, a wavelength conversion member made of a sintered body obtained by mixing glass powder and inorganic phosphor powder and melting and solidifying the glass powder is also disclosed (Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-234487

However, the wavelength conversion member obtained by curing the resin containing the phosphor may cause a decrease in brightness due to deterioration of the resin. Further, in the wavelength conversion member disclosed in Patent Document 1, the glass component may be mixed in the inorganic phosphor during the formation of the sintered body, which may interfere with the light emission of the phosphor. In addition, glass has a relatively low softening point, and when irradiated with high-power LED or LD light, a sintered body formed by melting and solidifying glass powder mixed with inorganic phosphor powder cannot withstand high temperatures. There is a risk.
Therefore, an object of the present invention is to provide a method for manufacturing a wavelength conversion member that emits light having a desired emission peak wavelength by irradiation with excitation light, and a wavelength conversion member.

Means for solving the above problems include the following aspects.

The first aspect of the present invention is to prepare a molded product obtained by molding a mixed powder containing a Ca-α-sialon phosphor and alumina particles, and to prepare the molded product in the range of 1000 ° C. or higher and 1600 ° C. or lower. It is a method for manufacturing a wavelength conversion member, which comprises first firing at a temperature to obtain a first sintered body.

A second aspect of the present invention is a wavelength conversion member containing a Ca-α-sialon phosphor and alumina.

According to the present invention, it is possible to provide a method for manufacturing a wavelength conversion member that emits light having a desired emission peak wavelength and a wavelength conversion member.

FIG. 1 is a flowchart showing a process sequence of a method for manufacturing a wavelength conversion member according to the first embodiment of the present disclosure. FIG. 2 is a flowchart showing a process sequence of a method for manufacturing a preferable wavelength conversion member according to the first embodiment of the present disclosure. FIG. 3 is an external photograph of the wavelength conversion member according to the third embodiment. FIG. 4 is an external photograph of the wavelength conversion member according to the twelfth embodiment. FIG. 5 is an external photograph of the first sintered body according to Comparative Example 5. FIG. 6 is a diagram showing chromaticity (x value, y value) of CIE chromaticity coordinates of each wavelength conversion member according to Examples 23 to 26. FIG. 7 is a diagram showing the chromaticity (x value, y value) of the CIE chromaticity coordinates of each wavelength conversion member according to Examples 27 to 30 and the first sintered body of Comparative Example 6.

Hereinafter, the method for manufacturing the wavelength conversion member and the wavelength conversion member according to the present invention will be described based on the embodiments. However, the embodiments shown below are examples for embodying the technical idea of the present invention, and the present invention is not limited to the following methods for manufacturing wavelength conversion members and wavelength conversion members. 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.

Method for manufacturing wavelength conversion member The method for manufacturing a wavelength conversion member according to the first embodiment of the present invention includes a Ca-α-sialon phosphor, an yttrium aluminum garnet-based phosphor, and alumina particles, if necessary. This includes preparing a molded product obtained by molding a mixed powder and primary firing the molded product at a temperature in the range of 1000 ° C. or higher and 1600 ° C. or lower to obtain a first sintered body.

The first sintered body containing the Ca-α-sialon phosphor and alumina obtained by the production method according to the first embodiment of the present invention emits light having a desired emission peak wavelength by irradiation with excitation light. It can be used as a wavelength conversion member. Since the wavelength conversion member made of the first sintered body is made of a ceramic containing a Ca-α-sialon phosphor and alumina, it has high thermal conductivity, high heat resistance, and can suppress deterioration. ..

According to the production method according to the first embodiment of the present invention, the Ca-α-sialone phosphor maintained the crystal structure of the Ca-α-sialon phosphor without partially decomposing the crystal structure. As it is, it is possible to obtain a wavelength conversion member made of a sintered body containing a Ca-α-sialon phosphor that is hardened together with alumina as an oxide and emits light having a desired emission peak wavelength by excitation light.

In a sintered body formed by melting and solidifying glass powder mixed with inorganic phosphor powder, the glass component may be mixed into the inorganic phosphor during the formation of the sintered body, which may interfere with the light emission of the phosphor. .. When an oxynitride phosphor such as a Ca-α-sialon phosphor and alumina particles, which are one of the same oxides as the oxide contained in the glass component, are fired, they are included in the composition of the oxynitride phosphor. Nitrogen and oxygen in the oxide easily react with each other, the reaction between the oxynitride and the oxide is promoted, the crystal structure of the oxynitride phosphor is partially decomposed, and the oxynitride contains a phosphor that emits light to a practical extent. It was speculated that a sintered body could not be obtained. However, according to the experiments conducted by the present inventors, it was found that the sintered body obtained by firing the Ca-α-sialon phosphor and the alumina particles actually emits light. This is because, for example, alumina is less susceptible to compositional changes due to heat than metal oxides other than alumina contained in the glass component, and oxygen released from the composition of alumina reacts with the Ca-α-sialon phosphor. Since it is difficult, it is presumed that even if a sintered body is formed using alumina particles, it is unlikely to adversely affect the light emission of the Ca-α-sialon phosphor.

In the method for producing a wavelength conversion member according to the first embodiment of the present invention, a mixed powder containing a Ca-α-sialon phosphor and alumina particles is further added to an yttrium aluminum garnet-based phosphor (hereinafter, “YAG-based”). It is also preferable to contain "fluorescent material"). When the mixed powder contains a Ca-α-sialon phosphor, alumina particles, and a YAG-based phosphor, the temperature of the molded product obtained by molding the mixed powder is in the range of 1000 ° C. or higher and 1500 ° C. or lower. It is preferable to obtain the first sintered body by primary firing with. The wavelength conversion member obtained by the production method according to the first embodiment of the present invention has a crystal structure of a Ca-α-sialon phosphor and a part of the crystal structure of a YAG-based phosphor without being decomposed. While maintaining the crystal structure of the phosphor, it is baked together with alumina, which is an oxide, to form the first sintered body. In the production method according to the first embodiment of the present invention, the Ca-α-sialone phosphor and the YAG-based phosphor are produced while maintaining the crystal structure of the Ca-α-sialon phosphor and the crystal structure of the YAG-based phosphor. Since it can be contained in one sintered body, the Ca-α-sialone phosphor and YAG-based fluorescence contained in one sintered body are not used in order to obtain a desired color tone without using a phosphor whose composition is changed. By adjusting the blending amount of the body, it is possible to obtain a wavelength conversion member that emits light in a desired color tone. Since the wavelength conversion member made of the first sintered body is made of a ceramic containing Ca-α-sialon phosphor, YAG-based phosphor and alumina, it has high thermal conductivity, high heat resistance, and deterioration. It can be suppressed.

Ca-α-Sialon Fluorescent As the Ca-α-sialon fluorescent material, it is preferable to use a Ca-α-sialon fluorescent material having a composition represented by the following formula (I).
_{Ca v (Si, Al) 12} (O, N) 16: Eu (I)
(In formula (I), v is a number satisfying 0 <v≤2.)
In the present specification, the plurality of elements described separated by commas (,) in the composition formula mean that at least one element among these plurality of elements is contained in the composition. The plurality of elements described separated by commas (,) in the composition formula include at least one element selected from a plurality of elements separated by commas in the composition, and two or more of the plurality of elements. May be included in combination.

As the Ca-α-sialon phosphor, it is more preferable to use a Ca-α-sialon phosphor having a composition represented by the following formula (II).
M _k Si _{12- (m + n)} Al _{m + n On} N _16-n : Eu (II)
(In formula (II), M is at least one element selected from the group consisting of Li, Mg, Ca, Sr, Y and lanthanoid elements (excluding La and Ce), and k, m, n is a number that satisfies 0 <k ≦ 2.0, 2.0 ≦ m ≦ 6.0, and 0 ≦ n ≦ 1.0.)

In the production method according to the first embodiment of the present invention, the Ca-α-sialon phosphor is used as a raw material for the first sintered body. The Ca-α-sialon phosphor as a raw material is preferably a powder. The average particle size of the Ca-α-sialon phosphor is preferably in the range of 2 μm or more and 30 μm or less, more preferably in the range of 3 μm or more and 25 μm or less, still more preferably in the range of 4 μm or more and 20 μm or less, and further. The range is preferably 5 μm or more and 15 μm or less. When the average particle size of the Ca-α-sialon phosphor is 2 μm or more, the Ca-α-sialon phosphor is substantially uniformly dispersed in the mixed powder, and the Ca-α-sialon phosphor is dispersed in the molded product. It can be dispersed substantially uniformly. When the average particle size of the Ca-α-sialon phosphor is 30 μm or less, the voids in the wavelength conversion member are reduced, so that the light conversion efficiency can be increased. In the present specification, the average particle size of the Ca-α-sialon phosphor is the particle size (median) in which the volume accumulation frequency from the small diameter side in the volume-based particle size distribution by the laser diffraction / scattering type particle size distribution measurement method reaches 50%. Diameter). The laser diffraction / scattering type particle size distribution measuring method can be measured using, for example, a laser diffraction type particle size distribution measuring device (MASTER SIZER 3000, manufactured by MALVERN).

The content of the Ca-α-sialon phosphor is preferably 0.1% by mass or more and 40% by mass or less, more preferably 0, in terms of the mass ratio of the charged material with respect to 100% by mass of the mixed powder constituting the molded product. It is 5.5% by mass or more and 38% by mass or less, more preferably 0.8% by mass or more and 35% by mass or less, and even more preferably 1% by mass or more and 30% by mass or less. When the content of the Ca-α-sialon phosphor is 0.1% by mass or more and 40% by mass or less with respect to 100% by mass of the mixed powder constituting the molded body, a wavelength conversion member having high photoconversion efficiency can be obtained. be able to. If the content of the Ca-α-sialon phosphor in the mixed powder constituting the molded product is less than 0.1% by mass, a wavelength conversion member having a desired conversion efficiency cannot be obtained. Further, when the content of the Ca-α-sialon phosphor in the mixed powder constituting the molded product exceeds 40% by mass, the content of the alumina particles becomes relatively small, and the density of the obtained wavelength conversion member becomes high. It may become smaller and the mechanical strength may decrease. Further, when the content of the Ca-α-sialon phosphor exceeds 40% by mass, the content of the Ca-α-sialon phosphor per volume in the wavelength conversion member is too large, so that, for example, the desired color tone and conversion efficiency are desired. In order to obtain the above, the thickness of the wavelength conversion member must be reduced, and the desired strength as the wavelength conversion member cannot be obtained, which may make handling difficult.

YAG-based phosphor As the YAG-based phosphor, a rare earth aluminate phosphor represented by (Y, Gd, Tb, Lu) ₃ Al ₅ O ₁₂ : Ce can be used.

As the YAG-based phosphor, it is preferable to use a rare earth aluminate phosphor having a composition represented by the following formula (III).
(Y _1-ab Gd _a Ce _b ) ₃ Al ₅ O ₁₂ (III)
(In formula (III), a and b are numbers that satisfy 0 ≦ a ≦ 0.500 and 0 <b ≦ 0.030.)

In the production method according to the first embodiment of the present invention, the YAG-based phosphor is used as a raw material for the first sintered body. The YAG-based phosphor as a raw material is preferably a powder. The average particle size of the YAG-based phosphor is preferably in the range of 1 μm or more and 50 μm or less, more preferably in the range of 1 μm or more and 40 μm or less, further preferably in the range of 2 μm or more and 30 μm or less, and even more preferably in the range of 2 μm. The range is 20 μm or less, and particularly preferably 2 μm or more and 15 μm or less. When the average particle size of the YAG-based phosphor is 1 μm or more, the YAG-based phosphor can be dispersed substantially uniformly in the mixed powder, and the YAG-based phosphor can be dispersed substantially uniformly in the molded product. When the average particle size of the YAG-based phosphor is 50 μm or less, the voids in the wavelength conversion member are reduced, so that the light conversion efficiency can be increased. In the present specification, the average particle size of the YAG-based phosphor is the average particle size (Fisher Sub-sieve sizer's number) measured by the Fisher Sub-sieve sizer method (hereinafter, also referred to as “FSSS method”). ). The FSSS method is a kind of air permeation method, and is a method of measuring the specific surface area by utilizing the flow resistance of air to determine the particle size.

The total content of the YAG-based phosphor and the Ca-α-sialon phosphor is the mass ratio of the charged product, preferably 0.1% by mass or more and 70% by mass, based on 100% by mass of the mixed powder constituting the molded product. % Or less, more preferably 0.5% by mass or more and 65% by mass or less, further preferably 0.8% by mass or more and 60% by mass or less, still more preferably 1% by mass or more and 55% by mass or less, and particularly preferably 2% by mass. It is 50% by mass or less. When the total content of the Ca-α-sialon phosphor and the YAG-based phosphor is 0.1% by mass or more and 70% by mass or less with respect to 100% by mass of the mixed powder constituting the molded product, the light conversion efficiency It is possible to obtain a high wavelength conversion member. When the total content of the Ca-α-sialon phosphor and the YAG-based phosphor is less than 0.1% by mass with respect to 100% by mass of the mixed powder constituting the molded product, the wavelength having the desired conversion efficiency. The conversion member cannot be obtained. Further, when the total content of the Ca-α-sialon phosphor and the YAG-based phosphor exceeds 70% by mass with respect to 100% by mass of the mixed powder constituting the molded product, the content of the phosphor becomes relatively large. Therefore, it is necessary to reduce the thickness of the first sintered body in order to obtain a desired wavelength conversion efficiency or a desired color tone. In the first sintered body thinned in order to obtain a desired color tone, the desired strength as a wavelength conversion member cannot be obtained, which may make handling difficult. Further, when the total content of the Ca-α-sialon phosphor and the YAG-based phosphor exceeds 70% with respect to 100% by mass of the mixed powder constituting the molded body, the amount of phosphor particles contained in the molded body increases. As the amount increases, the amount of alumina becomes relatively small, and it may be difficult to increase the relative density of the obtained wavelength conversion member.

The blending ratio of the Ca-α-sialon phosphor and the YAG-based phosphor in the mixed powder constituting the molded body was 100% by mass of the mixed powder constituting the molded body, and the Ca-α-sialon phosphor was added. Content is in the range of 0.1% by mass or more and 40% by mass or less, and the total content of Ca-α-sialon phosphor and YAG-based phosphor is in the range of 0.1% by mass or more and 70% by mass or less. It suffices if a desired wavelength conversion efficiency can be obtained and a desired color tone can be obtained. The total content of Ca-α-sialon phosphor particles and YAG-based phosphor particles is 0.1% by mass or more and 70% by mass or less with respect to 100% by mass of the mixed powder constituting the molded product, and Ca-α- If the content of the sialon phosphor is 0.1% by mass or more and 40% by mass or less, for example, the mass ratio of Ca-α-sialone phosphor particles to YAG-based phosphor particles (Ca-α-sialon phosphor particles: YAG). The system phosphor particles) are charged in a mass ratio, preferably in the range of 1:99 to 99: 1, more preferably in the range of 2:98 to 98: 2, and even more preferably in the range of 3:97 to 95 :. It is in the range of 5, and even more preferably in the range of 4:96 to 90:10.

With respect to 100% by mass of the mixed powder constituting the molded product, the total content of the Ca-α-sialon phosphor and the YAG-based phosphor is 0.1% by mass or more and 70% by mass. It may be in the range of% or less, and the content of Ca-α-sialon phosphor may be in the range of 0.1% by mass or more and 40% by mass or less. The content of the YAG-based phosphor is preferably 0.1% by mass or more and 69.9% by mass or less, more preferably 0.% by mass, based on 100% by mass of the mixed powder constituting the molded product. It is 5% by mass or more and 60% by mass or less, more preferably 0.8% by mass or more and 50% by mass or less, still more preferably 1% by mass or more and 40% by mass or less, and particularly preferably 1% by mass or more and 30% by mass or less. A wavelength conversion member capable of obtaining a desired color tone when the content of the YAG-based phosphor is in the range of 0.1% by mass or more and 69.9% by mass or less with respect to 100% by mass of the mixed powder constituting the molded body. Can be obtained.

Alumina particles In the production method according to the first embodiment of the present invention, the alumina particles are used as a raw material for the first sintered body. The alumina particles used as a raw material preferably have an alumina purity of 99.0% by mass or more, and more preferably an alumina purity of 99.5% by mass or more. When the powder constituting the molded product contains alumina particles having an alumina purity of 99.0% by mass or more, the transparency of the first sintered body or the second sintered body obtained becomes high, and light conversion occurs. The efficiency can be increased, and a wavelength conversion member having good thermal conductivity can be obtained. When commercially available alumina particles are used, the alumina purity can be referred to the alumina purity value described in the catalog. When the purity of alumina is unknown, after measuring the mass of the alumina particles, each alumina particle is fired at 800 ° C. for 1 hour in an air atmosphere, and the organic components and alumina particles adhering to the alumina particles absorb moisture. Alumina purity can be measured by removing the water content, measuring the mass of the alumina particles after firing, and dividing the mass of the alumina particles after firing by the mass of the alumina particles before firing. Alumina purity can be calculated, for example, by the following formula.
Alumina purity (mass%) = (mass of alumina particles after firing ÷ mass of alumina particles before firing) x 100

The average particle size of the alumina particles is preferably in the range of 0.1 μm or more and 1.3 μm or less, more preferably in the range of 0.2 μm or more and 1.0 μm or less, and further preferably in the range of 0.3 μm or more and 0.8 μm. The range is as follows, and more preferably 0.3 μm or more and 0.6 μm or less. When the average particle size of the alumina particles is within the above range, the powder of the Ca-α-sialon phosphor and the alumina particles can be uniformly mixed, and a wavelength conversion member made of a sintered body having few voids and high density can be obtained. Can be manufactured. In the present specification, the average particle size of the alumina particles means the average particle size (Fisher sub-sieve sizer's number) measured by the Fisher sub-sieve sizer (hereinafter, also referred to as “FSSS”) method. ..

The content of the alumina particles is the balance excluding the phosphor with respect to 100% by mass of the mixed powder constituting the molded product. When the mixed powder constituting the molded product is composed of Ca-α-sialon phosphors and alumina particles, the content of the alumina particles is the balance excluding the Ca-α-sialon phosphors from the mixed powder. It is preferably 60% by mass or more and 99.9% by mass or less.
When the mixed powder constituting the molded product is composed of a Ca-α-sialon phosphor, a YAG-based phosphor, and alumina particles, the content of the alumina particles is determined from the mixed powder to Ca-α-sialon. The balance excluding the total amount of the phosphor and the YAG-based phosphor, preferably 30% by mass or more and 99.9% by mass or less.

The type of alumina constituting the alumina particles is not particularly limited, and any of γ-alumina, δ-alumina, θ-alumina, and α-alumina can be used. It is preferable to use α-alumina because it is easily available, the powder of Ca-α-sialon phosphor and the alumina particles are easily mixed, and a molded product is easily formed.

In the method for manufacturing a wavelength conversion member according to the first embodiment of the present invention, a first sintered body containing a Ca-α-sialon phosphor and alumina particles is further subjected to hot isotropic pressure pressurization JIS Z2500. : 2000, No. It is preferable to include secondary firing at a temperature in the range of 1000 ° C. or higher and 1600 ° C. or lower by 2112 (HIP: Hot Isostatic Pressing, hereinafter also referred to as “HIP”) treatment to obtain a second sintered body. The second sintered body obtained by the method for manufacturing the wavelength conversion member is obtained because the first sintered body is secondarily fired at a temperature in the range of 1000 ° C. or higher and 1600 ° C. or lower by HIP treatment. The density of the sintered body can be further increased, and it can be used as a wavelength conversion member that emits light having a desired emission peak wavelength and having less color unevenness by irradiation with excitation light.

Further, the method for producing a wavelength conversion member according to the first embodiment of the present invention is a first sintered body containing a Ca-α-sialon phosphor, a YAG-based phosphor if necessary, and alumina particles. May further include secondary firing at a temperature in the range of 1000 ° C. or higher and 1500 ° C. or lower by HIP treatment to obtain a second sintered body. The second sintered body obtained by the method for manufacturing the wavelength conversion member is obtained by secondary firing the first sintered body at a temperature in the range of 1000 ° C. or higher and 1500 ° C. or lower by HIP treatment. The density of the sintered body can be further increased, and it can be used as a wavelength conversion member that emits light having a desired emission peak wavelength and having less color unevenness by irradiation with excitation light.

FIG. 1 is a flowchart showing an example of the process sequence of the method for manufacturing the wavelength conversion member according to the first embodiment. The process of the manufacturing method of the wavelength conversion member will be described with reference to FIG. The method for manufacturing the wavelength conversion member includes a molded body preparation step S102 and a primary firing step S103. The method for manufacturing the wavelength conversion member may include a powder mixing step S101 before the molded body preparation step S102, or may include a processing step S104 for processing the wavelength conversion member after the primary firing step S103. Good.

Powder mixing step In the powder mixing step, the powder of Ca-α-sialon phosphor and the alumina particles are mixed as the powder constituting the molded product. In the powder mixing step, it is preferable to mix Ca-α-sialon phosphor, YAG-based phosphor, and alumina particles as the powder constituting the molded product, if necessary. The powder can be mixed using a mortar and a pestle. The powder may be mixed using a mixing medium such as a ball mill. In addition, a molding aid may be used in order to facilitate the mixing of the powder and further facilitate the molding of the mixed powder. Examples of the molding aid include water and ethanol. The molding aid is preferably one that easily volatilizes in the subsequent firing step. It is not necessary to use a molding aid. When the molding aid is added, the amount of the molding aid is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and further preferably 5 parts by mass or less with respect to 100 parts by mass of the powder.

Molded Body Preparation Step In the molded body preparation step, a mixed powder containing a Ca-α-sialon phosphor,, if necessary, a YAG-based phosphor and alumina particles is molded into a desired shape to obtain a molded body. .. As a method for forming the mixed powder, a known method such as a press forming method can be adopted. For example, a die press forming method, a cold isostatic pressing method (CIP: Cold Isostatic Pressing, hereinafter, "CIP") It is also called "processing"). As the molding method, two types of methods may be adopted in order to adjust the shape of the molded body, or CIP processing may be performed after the die press molding. In the CIP treatment, it is preferable to press the molded product using water as a medium.

The pressure during press forming of the die is preferably 3 MPa to 50 MPa, more preferably 4 MPa to 20 MPa. If the pressure at the time of die press molding is within the above range, the molded product can be adjusted to a desired shape.

The pressure in the CIP treatment is preferably 50 MPa to 250 MPa, more preferably 100 MPa to 200 MPa. When the pressure in the CIP treatment is within the above range, the density of the molded product can be increased, and a molded product having a substantially uniform density as a whole can be obtained, and the sintering obtained in the subsequent primary firing step and secondary firing step can be obtained. You can increase the density of your body.

Primary firing step In the primary firing step, a molded product obtained by molding a mixed powder containing a Ca-α-sialon phosphor and alumina particles is first fired at a temperature in the range of 1000 ° C. or higher and 1600 ° C. or lower, and the first sintering process is performed. This is the process of getting a body. In the primary firing step, when the molded product contains a Ca-α-sialon phosphor, a YAG-based phosphor, and alumina particles, the primary firing is performed at a temperature in the range of 1000 ° C. or higher and 1500 ° C. or lower. This is the process of obtaining the sintered body of. In the primary firing step, it is possible to increase the sintering density of the Ca-α-sialon phosphor contained in the molded product and the alumina particles, and obtain a wavelength conversion member that emits light having a desired emission peak wavelength by excitation light.

A molded product obtained by molding a mixed powder containing a Ca-α-sialon phosphor and alumina particles is first fired in a range of 1000 ° C. or higher and 1600 ° C. or lower to obtain a first sintered body, after the primary firing. In the secondary firing, the density of the second sintered body obtained can be further increased. The first sintered body obtained by the primary firing step may have a lower density than the second sintered body obtained by the secondary firing step described later, but the first sintered body obtained by the primary firing step may be lower in density. The buddy emits light having a desired emission peak wavelength by irradiation with excitation light, and can be used as a wavelength conversion member.

Depending on the temperature and the content of the Ca-α-sialon phosphor in the first sintered body, the closed pores contained in the first sintered body are crushed by the secondary firing by the HIP treatment, and the first The Ca-α-sialon phosphor contained in the first sintered body is partially decomposed and evaporated to form open pores in the second sintered body, so that the first sintered body is formed. May have a higher density than the second sintered body.

The temperature of the primary firing is in the range of 1000 ° C. or higher and 1600 ° C. or lower. If the temperature of the primary firing is less than 1000 ° C., the relative density cannot be increased. When the temperature of the primary firing exceeds 1600 ° C., the Ca-α-sialon phosphor reacts with the alumina particles in the molded product, and the crystal structure of the Ca-α-sialon phosphor is decomposed to obtain the first obtained. The sintered body does not emit light even when irradiated with excitation light. The temperature of the primary firing is preferably in the range of 1100 ° C. or higher and lower than 1600 ° C., more preferably in the range of 1100 ° C. or higher and 1580 ° C. or lower, and further preferably in the range of 1200 ° C. or higher and 1570 ° C. or lower. It is more preferably 1300 ° C. or higher and 1560 ° C. or lower, further preferably 1400 ° C. or higher and 1550 ° C. or lower, still more preferably 1400 ° C. or higher and 1540 ° C. or lower, and even more preferably 1450 ° C. It is in the range of 1540 ° C. or lower, and more preferably 1470 ° C. or higher and 1540 ° C. or lower. The temperature of the primary firing may be in the range of 1400 ° C. or higher and 1500 ° C. or lower.

When the molded product is formed by molding a mixed powder containing a YAG-based phosphor together with a Ca-α-sialon phosphor and alumina particles, the primary firing temperature may be in the range of 1000 ° C. or higher and 1500 ° C. or lower. preferable. When the molded body is formed by molding a mixed powder containing a YAG-based phosphor together with a Ca-α-sialon phosphor, if the primary firing temperature is in the range of 1000 ° C. or higher and 1500 ° C. or lower, Ca-α- Even in a molded product obtained by molding a mixed powder containing a YAG-based phosphor together with a sialon phosphor, the crystal structure of the Ca-α-sialon phosphor contained in the molded product is not decomposed, and the excitation light is emitted. By irradiation, a first sintered body that emits light having a desired emission peak wavelength can be obtained. The temperature of the primary firing of a molded product obtained by molding a mixed powder containing a Ca-α-sialon phosphor, a YAG-based phosphor, and alumina particles is preferably in the range of 1100 ° C. or higher and 1500 ° C. or lower, more preferably 1100 ° C. The temperature is in the range of ° C. or higher and 1450 ° C. or lower, and more preferably in the range of 1200 ° C. or higher and 1450 ° C. or lower.

The primary firing is an atmospheric sintering method in which firing is performed in a non-oxidizing atmosphere without applying pressure or load, an atmospheric pressure sintering method in which firing is performed under pressure in a non-oxidizing atmosphere, and hot pressing. Examples thereof include a sintering method and a discharge plasma sintering method (SPS: Spark Plasma Sintering).

The primary firing is preferably performed in an atmosphere containing nitrogen gas. The atmosphere containing nitrogen gas is an atmosphere containing at least 99% by volume or more of nitrogen gas. The nitrogen gas in the atmosphere containing the nitrogen gas is preferably 99% by volume or more, more preferably 99.5% by volume or more. In addition to nitrogen gas, a trace amount of gas such as oxygen may be contained in the atmosphere containing nitrogen gas, but the content of oxygen in the atmosphere containing nitrogen gas shall be 1% by volume or less. Is more preferable, 0.5% by volume or less, still more preferably 0.1% by volume or less, still more preferably 0.01% by volume or less, and particularly preferably 0.001% by volume or less. When the atmosphere of the primary firing is an atmosphere containing nitrogen gas, the deterioration of the crystal structure of the Ca-α-sialon phosphor in the primary firing is suppressed, and the first one containing the Ca-α-sialon phosphor that maintains the crystal structure. A sintered body can be obtained.

The atmospheric pressure of the primary firing is preferably in the range of 0.2 MPa or more and 200 MPa or less. Atmospheric pressure refers to gauge pressure. The primary firing is preferably performed under an atmospheric pressure in the range of 0.2 MPa or more and 200 MPa or less. The Ca-α-sialon phosphor, which is an oxynitride, is more easily decomposed as the temperature rises. However, by performing the primary firing in a pressurized atmosphere of 0.2 MPa or more and 200 MPa or less, the Ca-α-sialon phosphor can be decomposed. A first sintered body that is more suppressed and has a high emission intensity can be obtained. As the gauge pressure, the atmospheric pressure is more preferably 0.2 MPa or more and 1.0 MPa or less, and further preferably 0.8 MPa or more and 1.0 MPa or less.

The time of the primary firing may be appropriately selected according to the atmospheric pressure. The heat treatment time is, for example, 0.5 hours or more and 20 hours or less, preferably 1 hour or more and 10 hours or less.

FIG. 2 is a flowchart showing an example of the process sequence of a method for manufacturing a preferable wavelength conversion member according to the first embodiment. A preferred method for manufacturing a wavelength conversion member includes a molded body preparation step S202, a primary firing step S203, and a secondary firing step S204. A preferred method for manufacturing a wavelength conversion member may include a powder mixing step S201 before the molded body preparation step S202, and may include a processing step S205 for processing the wavelength conversion member after the secondary firing step S204. You may.

Secondary firing step In the secondary firing step, the first sintered body obtained by primary firing a molded product obtained by molding a mixed powder containing a Ca-α-sialon phosphor and alumina particles is subjected to 1000 by HIP treatment. This is a step of secondary firing at a temperature in the range of ° C. or higher and 1600 ° C. or lower to obtain a second sintered body. In the secondary firing step, the HIP treatment can reduce the voids contained in the first sintered body and increase the density of the second sintered body. The dense second sintered body obtained by the HIP treatment becomes more transparent. The second sintered body obtained by the secondary firing step can further increase the density of the sintered body, emits light having a desired emission peak wavelength by irradiation with excitation light, and can be used as a wavelength conversion member. it can.

The temperature of the secondary firing is in the range of 1000 ° C. or higher and 1600 ° C. or lower. If the temperature of the secondary firing is less than 1000 ° C., a second sintered body having a higher relative density than the first sintered body cannot be obtained even if the secondary firing is performed. When the temperature of the secondary firing exceeds 1600 ° C., the Ca-α-sialon phosphor reacts with the alumina particles in the first sintered body, and a part of the crystal structure of the Ca-α-sialon phosphor is decomposed. The emission intensity of the obtained second sintered body is lowered. The temperature of the secondary firing is preferably in the range of 1100 ° C. or higher and 1580 ° C. or lower, more preferably in the range of 1200 ° C. or higher and 1570 ° C. or lower, still more preferably in the range of 1300 ° C. or higher and 1560 ° C. or lower, and further. The range is preferably 1400 ° C. or higher and 1550 ° C. or lower.

When the first sintered body is a molded body obtained by molding a mixed powder containing a YAG-based phosphor together with a Ca-α-sialon phosphor and alumina particles, the secondary firing temperature is 1000 ° C. or higher and 1500 ° C. The range is preferably as follows. When the first sintered body contains a YAG-based phosphor together with a Ca-α-sialone phosphor, if the temperature of the secondary firing is in the range of 1000 ° C. or higher and 1500 ° C. or lower, Ca-α-sialon fluorescence A YAG-based phosphor is contained in the molded body together with the body, and even if a trace amount of a fluorine-containing compound that is contained in the YAG-based phosphor and functions as a flux in the manufacturing process remains, for example, in a trace amount. The density of the sintered body can be increased without decomposing the crystal structure of the Ca-α-sialon phosphor by the residual fluorine-containing compound. The temperature of the secondary firing of the first sintered body containing the Ca-α-sialon phosphor, the YAG-based phosphor, and the alumina particles is preferably in the range of 1100 ° C. or higher and 1500 ° C. or lower, more preferably 1100 ° C. It is in the range of 1450 ° C. or lower, more preferably 1200 ° C. or higher and 1450 ° C. or lower.

The secondary firing is preferably carried out in an inert gas atmosphere. The inert gas atmosphere means an atmosphere containing argon, helium, nitrogen or the like as the main components of the atmosphere. Here, the term "argon, helium, nitrogen or the like as the main component in the atmosphere" means that the atmosphere contains at least 50% by volume or more of at least one gas selected from the group consisting of argon, helium and nitrogen. The oxygen content in the inert gas atmosphere is preferably 1% by volume or less, more preferably 0.5% by volume or less, still more preferably 0.1% by volume or less, still more preferably 0.01% by volume. % Or less, particularly preferably 0.001% by volume or less. The inert gas atmosphere may be the same atmosphere as the atmosphere containing nitrogen gas in the primary firing, and the content of nitrogen gas contained in the atmosphere containing nitrogen gas is preferably 99% by volume or more, more preferably 99% by volume or more. It is 99.5% by volume or more. When the atmosphere of the secondary firing is an inert gas atmosphere, deterioration of the crystal structure of the Ca-α-sialon phosphor in the secondary firing is suppressed, and the second including the Ca-α-sialon phosphor that maintains the crystal structure. Sintered body can be obtained.

The pressure in the HIP treatment for performing the secondary firing is preferably 50 MPa or more and 300 MPa or less, and more preferably 80 MPa or more and 200 MPa or less. When the pressure in the HIP treatment is in the above range, the entire sintered body can be made uniform and have a higher density without deteriorating the crystal structure of the Ca-α-sialon phosphor.

The time of the HIP treatment for performing the secondary firing is, for example, 0.5 hours or more and 20 hours or less, preferably 1 hour or more and 10 hours or less.

Processing Step The method for manufacturing a wavelength conversion member may include a processing step of processing the obtained wavelength conversion member made of a first sintered body or a second sintered body. Examples of the processing step include a step of cutting the obtained wavelength conversion member into a desired size. As a method for cutting the wavelength conversion member, a known method can be used, and examples thereof include blade dicing, laser dicing, and wire saw. Of these, a wire saw is preferable because the cut surface is flattened with high accuracy. A wavelength conversion member having a desired thickness and size can be obtained by the processing step. The thickness of the wavelength conversion member is not particularly limited, but in consideration of mechanical strength and wavelength conversion efficiency, it is preferably in the range of 1 μm or more and 1 mm or less, more preferably 10 μm or more and 800 μm or less, and further preferably 50 μm or more and 500 μm or less. More preferably, it is in the range of 100 μm or more and 400 μm or less.

Relative Density of First Sintered Body In the method for manufacturing a wavelength conversion member of the first embodiment, the first sintered body obtained in the primary firing step has a relative density of preferably 80% or more, more preferably 80% or more. It is 85% or more, more preferably 90% or more, even more preferably 91% or more, and particularly preferably 92% or more. The relative density of the first sintered body may be 100% or less, and the relative density of the first sintered body may be 99% or less or 98% or less. When the relative density of the first sintered body is 80% or more, it can be used as a wavelength conversion member having a desired emission peak wavelength by irradiation with excitation light. Further, when the secondary firing is performed after the primary firing, the relative density of the first sintered body is 80% or more, so that the density of the second sintered body is further increased in the secondary firing after the primary firing. Since the number of voids in the wavelength conversion member is reduced and the scattering of light in the voids is suppressed, it is possible to manufacture a wavelength conversion member having high light conversion efficiency. When the wavelength conversion member is made of the first sintered body, the relative density of the wavelength conversion member is the same as the relative density of the first sintered body.

In the present specification, the relative density of the first sintered body means a value calculated by the apparent density of the first sintered body with respect to the true density of the first sintered body. The relative density is calculated by the following formula (1).
Relative density (%) = (apparent density of the first sintered body / true density of the first sintered body) x 100 (1)
When the first sintered body is composed of Ca-α-sialon phosphor and alumina particles, the true density of the first sintered body is the mixed powder 100 for the molded body constituting the first sintered body. The value obtained by multiplying the mass ratio of the Ca-α-sialon phosphor to the mass% by the true density of the Ca-α-sialon phosphor and the mass ratio of the alumina particles to 100 mass% of the mixed powder for the molded product. Is the sum of the value obtained by multiplying the true density of the alumina particles by. The true density of the first sintered body is calculated by the following formula (2-1).
True density of the first sintered body = (mass ratio of Ca-α-sialon phosphor to 100% by mass of mixed powder for molded body x true density of Ca-α-sialon phosphor) + (for molded body Mass ratio of alumina particles to 100% by mass of mixed powder x true density of alumina particles) (2-1)
When the first sintered body is composed of a Ca-α-sialon phosphor, a YAG-based phosphor, and alumina particles, the true density of the first sintered body is the molded body constituting the first sintered body. The value obtained by multiplying the mass ratio of the Ca-α-sialon phosphor to 100% by mass of the mixed powder for use by the true density of the Ca-α-sialon phosphor and 100% by mass of the mixed powder for the molded product. The value obtained by multiplying the mass ratio of the YAG-based phosphor to the mass ratio of the YAG-based phosphor by the true density of the YAG-based phosphor, and the mass ratio of the alumina particles to 100 mass% of the mixed powder for the molded product multiplied by the true density of the alumina particles. It is the sum of the values obtained. The true density of the first sintered body is calculated by the following formula (2-2).
True density of the first sintered body = (mass ratio of Ca-α-sialon phosphor to 100% by mass of mixed powder for molded body x true density of Ca-α-sialon phosphor) + (for molded body Mass ratio of YAG-based phosphor to 100 mass% of mixed powder x true density of YAG-based phosphor) + (mass ratio of alumina particles to 100 mass% of mixed powder for molded product x true density of alumina particles) (2 -2)
The apparent density of the first sintered body is a value obtained by dividing the mass of the first sintered body by the volume of the first sintered body obtained by the Archimedes method. The apparent density of the first sintered body is calculated by the following formula (3).
Apparent density of the first sintered body = mass of the first sintered body ÷ volume of the first sintered body obtained by the Archimedes method (3)

Relative Density of Second Sintered Body The second sintered body obtained after the secondary firing has a relative density of preferably 90% or more, more preferably 91% or more, still more preferably 92% or more, still more preferably. Is 93% or more, particularly preferably 95% or more. When the relative density of the wavelength conversion member made of the second sintered body is 90% or more, the voids of the wavelength conversion member are reduced, and the light conversion efficiency can be increased. Further, since the relative density of the second sintered body is 90% or more, for example, in the processing process, the wavelength conversion member made of the processed second sintered body is formed without being chipped even if the processing is performed. Obtainable. The relative density of the second sintered body may be 100% or less, and the relative density of the second sintered body may be 99.9% or less or 99.8% or less.

In the present specification, the relative density of the second sintered body means a value calculated by the apparent density of the second sintered body with respect to the true density of the second sintered body. When the wavelength conversion member is made of the second sintered body, the relative density of the wavelength conversion member is the same as the relative density of the second sintered body. The relative density is calculated by the following formula (4).
Relative density (%) = (apparent density of the second sintered body / true density of the second sintered body) x 100 (4)
The method for calculating the true density of the second sintered body is the same as the method for calculating the true density of the first sintered body. The true density of the second sintered body is the same value as the true density of the first sintered body.
The apparent density of the second sintered body is a value obtained by dividing the mass of the second sintered body by the volume of the second sintered body obtained by the Archimedes method. The apparent density of the second sintered body is calculated by the following formula (5).
Apparent density of the second sintered body = mass of the second sintered body ÷ volume of the second sintered body obtained by the Archimedes method (5)

The obtained first sintered body or second sintered body can emit light having a desired emission peak wavelength by irradiation with excitation light, and can be used as a wavelength conversion member. The first sintered body or the second sintered body having a relative density of 90% or more can increase the relative emission intensity and can increase the light conversion efficiency.

Wavelength conversion member The wavelength conversion member contains a Ca-α-sialon phosphor and alumina, and the content of the Ca-α-sialon phosphor is preferably 0.1% by mass or more and 40% by mass or less. When the content of the Ca-α-sialon phosphor in the wavelength conversion member is 0.1% by mass or more, a desired conversion efficiency can be obtained. If the content of the Ca-α-sialon phosphor in the wavelength conversion member is high, the content of the powder of the Ca-α-sialon phosphor per volume in the wavelength conversion member is too large, and the desired color tone and conversion In order to obtain efficiency, it is necessary to reduce the volume of the wavelength conversion member. For example, in order to reduce the volume of the obtained wavelength conversion member, the thickness must be reduced, which makes handling difficult. Further, when the content of the Ca-α-sialon phosphor in the wavelength conversion member is large, the amount of alumina in the wavelength conversion member is relatively reduced, and the Ca-α-sialon phosphor and alumina in the wavelength conversion member are relatively reduced. Adhesion may be reduced and voids may be formed, resulting in a decrease in light conversion efficiency. For the content of Ca-α-sialon phosphor in the wavelength conversion member, elemental analysis of the elements constituting the Ca-α-sialon phosphor is performed using ICP emission spectroscopic analysis (Inductively Coupled Plasma Atomic Emission Spectroscopy). From the results of the element analysis obtained, the content of the Ca-α-sialon phosphor contained in the wavelength conversion member can be measured. The Ca-α-sialon phosphor contained in the wavelength conversion member is preferably a Ca-α-sialon phosphor having a composition represented by the formula (I) or (II).

When the wavelength conversion member contains a Ca-α-sialon phosphor, alumina particles, and a YAG-based phosphor, the total content of the YAG-based phosphor and the Ca-α-sialon phosphor is 0.1. It is preferably mass% or more and 70 mass% or less. When the Ca-α-sialone phosphor and the YAG-based phosphor are contained in the wavelength conversion member, the content of the Ca-α-sialon phosphor is 0.1% by mass or more and 40% by mass or less, and Ca. When the total content of the -α-sialon phosphor and the YAG-based phosphor satisfies the range of 0.1% by mass or more and 70% by mass or less, light emission of a desired color tone can be obtained by irradiation with excitation light. The content of the Ca-α-sialon phosphor is 0.1% by mass or more and 40% by mass or less, and the total content of the Ca-α-sialon phosphor and the YAG-based phosphor is 0.1% by mass or more and 70% by mass. As long as it satisfies the range of mass% or less, for example, the content of the YAG-based phosphor in the wavelength conversion member may be 69.9 mass% or 0.1 mass%. As the YAG-based phosphor contained in the wavelength conversion member, a rare earth aluminate phosphor represented by (Y, Gd, Tb, Lu) ₃ Al ₅ O ₁₂ : Ce can be used. The YAG-based phosphor contained in the wavelength conversion member is preferably a YAG-based phosphor represented by the above formula (III). The total content of Ca-α-sialon phosphor and YAG-based phosphor in the wavelength conversion member was determined by using ICP emission spectroscopic analysis (Inductively Coupled Plasma Atomic Emission Spectroscopy) for Ca-α-sialon phosphor and YAG. Elemental analysis of the elements constituting the system phosphor can be performed, and the total content of the Ca-α-sialon phosphor and the YAG system phosphor contained in the wavelength conversion member can be measured from the obtained element analysis result. ..

The Ca-α-sialon phosphor or the YAG-based phosphor in the wavelength conversion member is distinguished from the alumina in the wavelength conversion member by the grain boundary of the Ca-α-sialon phosphor or the YAG-based phosphor. In the wavelength conversion member, there is a Ca-α-sialon phosphor or a YAG-based phosphor having a crystal structure different from that of the alumina crystal structure, and the alumina, the Ca-α-sialon phosphor, and the YAG-based fluorescence if necessary. The body is integrated to form a ceramic wavelength conversion member. The wavelength conversion member according to the second embodiment of the present invention comprises a wavelength conversion member made of a first sintered body or a second sintered body obtained by the manufacturing method according to the first embodiment of the present invention. It is preferably a wavelength conversion member. The wavelength conversion member made of the first sintered body or the wavelength conversion member made of the second sintered body obtained by the production method according to the first embodiment of the present invention has a relative density of 80% or more. preferable. When the relative density of the wavelength conversion member is 80% or more, the wavelength conversion member has high emission intensity and high light conversion efficiency. Further, since the wavelength conversion member has a relative density of 80% or more, the wavelength conversion member of ceramics emits light without cracking or chipping even when it is processed by cutting or the like. When used in an apparatus, the occurrence of color unevenness can be suppressed. The relative density of the wavelength conversion member is more preferably 85% or more, further preferably 90% or more, still more preferably 91% or more, and particularly preferably 92% or more. The relative density of the wavelength conversion member may be 100%, 99.9% or less, or 99.8% or less.

The wavelength return conversion member obtained by the manufacturing method of the first embodiment or the wavelength conversion member according to the second embodiment converts the excitation light emitted from the light emitting element by combining with the light emitting element of the LED or LD. Therefore, it is possible to construct a light emitting device that emits light having a desired emission peak wavelength and emits mixed color light by the light from the light emitting element and the light whose wavelength is converted by the wavelength conversion member. As the light emitting element, for example, a light emitting element that emits light in a wavelength range of 350 nm or more and 500 nm or less can be used. As the light emitting device, for example, a semiconductor light emitting device using a nitride based semiconductor (In _X Al _Y Ga _1-XY N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) can be used. By using a semiconductor light emitting device as an excitation light source, it is possible to obtain a stable light emitting device having high efficiency, high output linearity with respect to input, and resistance to mechanical impact.

Hereinafter, the present invention will be specifically described with reference to Examples. The present invention is not limited to these examples.

Examples 1 to 22 are from a wavelength conversion member composed of a first sintered body containing a Ca-α-sialon phosphor and alumina, or a second sintered body containing a Ca-α-sialon phosphor and alumina. A wavelength conversion member was manufactured. In Comparative Examples 1 to 5, first sintered bodies containing a Ca-α-sialon phosphor and a metal oxide other than alumina were produced.

Example 1
Powder mixing process 1 part by mass (molding) of Ca-α-sialon phosphor (product name: Aron Bright variety YL-600, manufactured by Denka Co., Ltd.) with an average particle size of 13.0 μm measured by a laser diffraction / scattering type particle size distribution measurement method. Ca-α-sialon phosphor (1% by mass based on 100% by mass of mixed powder for body) and α-alumina particles having an average particle size of 0.5 μm measured by the FSSS method (product name: AA03, Sumitomo Chemical) 99 parts by mass of alumina manufactured by Kogyo Co., Ltd. with an alumina purity of 99.5% by mass) was weighed and mixed using a milk bowl and a milk stick to prepare a mixed powder for a molded product. In Table 1 or Table 2, the content (mass%) of the Ca-α-sialon phosphor indicates the mass ratio of the Ca-α-sialon phosphor charged to 100% by mass of the mixed powder for the molded product. In Table 1 or Table 2, the content of the alumina particles in each example is the balance obtained by subtracting the content (mass%) of the Ca-α-sialon phosphor from 100% by mass of the mixed powder for the molded product.

Mold preparation step The mixed powder was filled in a mold to form a cylindrical molded body having a diameter of 17.0 mm and a thickness of 10 mm at a pressure of 4.6 MPa (46.9 kgf / cm ² ). The obtained molded product was placed in a packaging container, vacuum-packed, and subjected to CIP treatment at 176 MPa using a cold isotropic pressure (CIP) device (manufactured by KOBELCO) as a pressure medium.

Primary firing step The obtained molded product is held in a firing furnace (manufactured by Fuji Denpa Kogyo Co., Ltd.) in a nitrogen gas atmosphere (nitrogen: 99% by volume or more) at a temperature of 0.9 MPa and 1500 ° C. for 6 hours for primary firing. The first sintered body was obtained. The obtained first sintered body 1 was used as a wavelength conversion member. The content (mass%) of the Ca-α-sialon phosphor in the wavelength conversion member composed of the first sintered body 1 of Example 1 is Ca-α-sialon with respect to 100% by mass of the mixed powder for the molded product. It is almost equal to the mass ratio of the phosphor charged.

Example 2
The first sintered body 2 was prepared in the same manner as in Example 1 except that a mixed powder prepared by mixing 3 parts by mass of a Ca-α-sialon phosphor and 97 parts by mass of α-alumina particles was prepared. Was obtained and used as a wavelength conversion member. In Examples 2 to 22, the content of the Ca-α-sialon phosphor in the wavelength conversion member composed of the first sintered body or the second sintered body is based on 100% by mass of the mixed powder for the molded product. It is almost equal to the mass ratio of the charge of Ca-α-sialon phosphor.

Example 3
The first sintered body 3 was prepared in the same manner as in Example 1 except that a mixed powder was prepared in which 5 parts by mass of the Ca-α-sialon phosphor and 95 parts by mass of the α-alumina particles were mixed. Was obtained and used as a wavelength conversion member.

Example 4
The first sintered body 4 was prepared in the same manner as in Example 1 except that a mixed powder was prepared in which 10 parts by mass of Ca-α-sialon phosphor and 90 parts by mass of α-alumina particles were mixed. Was obtained and used as a wavelength conversion member.

Example 5
The first sintered body 5 was prepared in the same manner as in Example 1 except that a mixed powder prepared by mixing 20 parts by mass of a Ca-α-sialon phosphor and 80 parts by mass of α-alumina particles was prepared. Was obtained and used as a wavelength conversion member.

Example 6
A mixed powder prepared by mixing 5 parts by mass of Ca-α-sialon phosphor and 95 parts by mass of α-alumina particles was prepared, and the primary firing temperature was set to 1400 ° C. in the same manner as in Example 1. , The first sintered body 6 was obtained and used as a wavelength conversion member.

Example 7
A mixed powder prepared by mixing 5 parts by mass of Ca-α-sialon phosphor and 95 parts by mass of α-alumina particles was prepared, and the primary firing temperature was set to 1450 ° C. in the same manner as in Example 1. , The first sintered body 7 was obtained and used as a wavelength conversion member.

Example 8
A mixed powder prepared by mixing 5 parts by mass of Ca-α-sialon phosphor and 95 parts by mass of α-alumina particles was prepared, and the primary firing temperature was set to 1550 ° C. in the same manner as in Example 1. , The first sintered body 8 was obtained and used as a wavelength conversion member.

Example 9
A mixed powder prepared by mixing 5 parts by mass of Ca-α-sialon phosphor and 95 parts by mass of α-alumina particles was prepared, and the same as in Example 1 except that the secondary firing temperature was set to 1600 ° C. The first sintered body 9 was obtained and used as a wavelength conversion member.

Example 10
Secondary firing step Using the first sintered body 1 obtained in Example 1, using a hot isotropic pressurization (HIP) device (manufactured by KOBELCO), nitrogen was used as a pressure medium using nitrogen gas. In a gas atmosphere (nitrogen: 99% by volume or more), secondary firing was performed at 1500 ° C., 195 MPa for 2 hours by HIP treatment to obtain a second sintered body 10, and this second sintered body was obtained. 10 was used as a wavelength conversion member.

Example 11
Secondary firing step Using the first sintered body 2 obtained in Example 2, HIP treatment was performed in the same manner as in Example 10 to obtain a second sintered body 11, and this second sintered body was obtained. The body 11 was used as a wavelength conversion member.

Example 12
Secondary firing step Using the first sintered body 3 obtained in Example 3, HIP treatment was performed in the same manner as in Example 10 to obtain a second sintered body 12, and this second sintered body was obtained. The body 12 was used as a wavelength conversion member.

Example 13
Secondary firing step Using the first sintered body 4 obtained in Example 4, HIP treatment was performed in the same manner as in Example 10 to obtain a second sintered body 13, and this second sintered body was obtained. The body 13 was used as a wavelength conversion member.

Example 14
Secondary firing step Using the first sintered body 5 obtained in Example 5, HIP treatment was performed in the same manner as in Example 10 to obtain a second sintered body 14, and this second sintered body was obtained. The body 14 was used as a wavelength conversion member.

Example 15
Secondary firing step Using the first sintered body 6 obtained in Example 6, HIP treatment was performed in the same manner as in Example 10 to obtain a second sintered body 15, and this second sintered body was obtained. The body 15 was used as a wavelength conversion member.

Example 16
Secondary firing step Using the first sintered body 7 obtained in Example 7, HIP treatment was performed in the same manner as in Example 10 to obtain a second sintered body 16, and this second sintered body was obtained. The body 16 was used as a wavelength conversion member.

Example 17
Secondary firing step Using the first sintered body 8 obtained in Example 8, HIP treatment was performed in the same manner as in Example 10 to obtain a second sintered body 17, and this second sintered body was obtained. The body 17 was used as a wavelength conversion member.

Example 18
Secondary firing step The first sintered body 3 obtained in Example 3 was used, and the secondary firing was performed by HIP treatment in the same manner as in Example 10 except that the temperature was set to 1400 ° C., and the second firing step was performed. A sintered body 18 was obtained, and the second sintered body 18 was used as a wavelength conversion member.

Example 19
Secondary firing step The first sintered body 3 obtained in Example 3 was used, and the secondary firing was performed by HIP treatment in the same manner as in Example 10 except that the temperature was set to 1450 ° C., and the second firing step was performed. A sintered body 19 was obtained, and the second sintered body 19 was used as a wavelength conversion member.

Example 20
Secondary firing step Using the first sintered body 3 obtained in Example 3, the secondary firing was performed by HIP treatment in the same manner as in Example 10 except that the temperature was set to 1550 ° C., and the second firing step was performed. A sintered body 20 was obtained, and the second sintered body 20 was used as a wavelength conversion member.

Example 21
Secondary firing step The first sintered body 9 obtained in Example 9 was used, and the secondary firing was performed by HIP treatment in the same manner as in Example 10 except that the temperature was set to 1500 ° C., and the second firing step was performed. A sintered body 21 was obtained, and the second sintered body 21 was used as a wavelength change conversion member.

Example 22
Secondary firing step The first sintered body 3 obtained in Example 3 was used, and the secondary firing was performed by HIP treatment in the same manner as in Example 10 except that the temperature was set to 1600 ° C. A sintered body 22 was obtained, and the second sintered body 22 was used as a wavelength conversion member.

Comparative Example 1
Powder mixing step Ca-α-sialon phosphor 5 parts by mass and titanium oxide particles (manufactured by Toho Titanium Co., Ltd., titanium oxide purity 99.5% by mass, average size: 2.10 to 2.55 μm (catalog value) ) Was mixed with 95 parts by mass to prepare a mixed powder. In Table 3, the content (mass%) of the Ca-α-sialon phosphor is the mass ratio of the Ca-α-sialon phosphor charged to 100% by mass of the mixed powder for the molded product. In Table 3, the content of the metal oxide particles in each Comparative Example is the balance obtained by subtracting the content (mass%) of the Ca-α-sialon phosphor from 100% by mass of the mixed powder for the molded product. In Comparative Examples 1 to 5 and the formula (2-1-1) described later, the metal oxide particles are α-alumina particles, titanium oxide particles, tantalum pentoxide particles, yttrium oxide particles, hafnium oxide particles, or zirconium oxide. Refers to any of the metal oxide particles of the particles.

Mold preparation step The mixed powder was filled in a mold to form a cylindrical molded body having a diameter of 17.0 mm and a thickness of 10 mm at a pressure of 4.6 MPa (46.9 kgf / cm ² ). The obtained molded product was placed in a packaging container, vacuum-packed, and subjected to CIP treatment at 176 MPa using a cold isotropic pressure (CIP) device (manufactured by KOBELCO) as a pressure medium.

Primary firing step The obtained compact is held in a firing furnace (manufactured by Fuji Dempa Kogyo Co., Ltd.) in a nitrogen gas atmosphere (nitrogen: 99% by volume or more) at a temperature of 1500 ° C. for 6 hours to perform primary firing. One sintered body was obtained, but the relative density was 71.0%. The light emission of the first sintered body could not be confirmed. Since no light emission could be confirmed and the relative density was as small as 71.0%, the HIP treatment of the first sintered body was not carried out. When the relative density of the first sintered body is less than 80%, there are many voids contained in the first sintered body, and the relative density of the second sintered body obtained even by performing secondary firing by HIP treatment. This is because the density cannot be increased above 90%.

Comparative Example 2
5 parts by mass of Ca-α-sialon phosphor and 95 parts by mass of tantalum pentoxide particles (manufactured by HC Starck Co., Ltd., tantalum pentoxide purity 99.5% by mass, average particle size 0.7 μm by FSSS method) The first sintered body was obtained in the same manner as in Comparative Example 1 except that the mixed powder mixed with the parts was prepared, but the relative density was 64.3%. The light emission of the first sintered body could not be confirmed. Since no light emission could be confirmed and the relative density was as small as 64.3%, the HIP treatment of the first sintered body was not carried out.

Comparative Example 3
5 parts by mass of Ca-α-sialon phosphor and 95 parts by mass of yttrium oxide particles (manufactured by Japan Yttrium Co., Ltd., yttrium oxide purity 99.5% by mass, average particle size by FSSS method 1.8 μm) were mixed. The first sintered body was obtained in the same manner as in Comparative Example 1 except that the mixed powder was prepared, but the relative density was 49.6%. The light emission of the first sintered body could not be confirmed. Since no light emission could be confirmed and the relative density was as small as 49.6%, the HIP treatment of the first sintered body was not carried out.

Comparative Example 4
A mixture of 5 parts by mass of Ca-α-sialon phosphor and 95 parts by mass of hafnium oxide particles (manufactured by High Purity Chemical Co., Ltd., hafnium oxide purity 98% by mass, average particle size 2.0 μm by FSSS method). The first sintered body was obtained in the same manner as in Comparative Example 1 except that the powder was prepared, but the relative density was 51.2%. The light emission of the first sintered body could not be confirmed. Since no light emission could be confirmed and the relative density was as small as 51.2%, the HIP treatment of the first sintered body was not carried out.

Comparative Example 5
5 parts by mass of Ca-α-sialon phosphor and 95 parts by mass of zirconium oxide particles (manufactured by Wako Pure Chemical Industries, Ltd., zirconium oxide purity 99% by mass, average particle size 2.0 μm by FSSS method) were mixed. The first sintered body was obtained in the same manner as in Comparative Example 1 except that the mixed powder was prepared, but the relative density was 67.0%. The light emission of the first sintered body could not be confirmed. Since no light emission could be confirmed and the relative density was as small as 67.0%, the HIP treatment of the first sintered body was not carried out.

Measurement of average particle size by laser diffraction scattering type particle size distribution measurement method The particles of Ca-α-sialon phosphor used in each example and comparative example have a small diameter in the volume-based particle size distribution by the laser diffraction scattering type particle size distribution measurement method. The particle size (median diameter) at which the volume accumulation frequency from the side reaches 50% was defined as the average particle size, and was measured using a laser diffraction type particle size distribution measuring device (MASTER SIZER 3000, manufactured by MALVERN).

Measurement of average particle size by FSSS method The α-alumina particles used in the examples and the tantalum pentoxide particles, yttrium oxide particles, hafnium oxide particles and zirconium oxide particles used in the comparative examples have average particle sizes by the FSSS method. (Fisher sub-sieve sizer's number) was measured.

Measurement of Purity of α-Alumina After measuring the mass of α-alumina particles used in the examples, the α-alumina particles were fired at 800 ° C. for 1 hour in an air atmosphere, and the organic particles adhering to the α-alumina particles Minutes and moisture absorbed by the α-alumina particles are removed, the mass of the α-alumina particles after firing is measured, and as shown in the following formula, the mass of the α-alumina particles after firing is the α- before firing. The α-alumina purity was measured by dividing by the mass of the alumina particles.
α-Alumina purity (mass%) = (mass of α-alumina particles after firing ÷ mass of α-alumina particles before firing) × 100

Measurement of Relative Density of First Sintered Body In Examples 1 to 9 and Comparative Examples 1 to 5, the relative density of each first sintered body was measured. The apparent densities and relative densities of the first sintered bodies of Examples 1 to 9 are shown in Table 1. In Comparative Examples 1 to 5, the relative densities were calculated based on the following formulas (1) to (3) in the same manner as in the first sintered bodies of Examples 1 to 9. Table 3 shows the relative densities of the first sintered bodies of Comparative Examples 1 to 5.
The relative density was calculated by the following formula (1).
Relative density (%) = (apparent density of the first sintered body / true density of the first sintered body) x 100 (1)

The true density of the first sintered body was calculated from the following formula (2-1-1). The true density of the α-alumina particles used in Examples 1 to 9 was 3.98 g / cm ^3, and the true density of the titanium oxide particles used in Comparative Example 1 was 4.26 g / cm ³ , which was used in Comparative Example 2. five true density of the tantalum oxide particles 8.7 g / cm ^3, the true density of yttrium oxide particles used in Comparative example 3 is 5.01 g / cm ^3, the true density of the hafnium oxide particles used in Comparative example 4 9. 68 g / cm ^3, the true density of the zirconium oxide particles used in Comparative example 5 was calculated as 5.6g / cm ^3,. The true density of the Ca-α-sialon phosphor was calculated as 3.22 g / cm ³ .
True density of the first sintered body = (mass ratio of Ca-α-sialon phosphor to 100% by mass of mixed powder for molded body x true density of Ca-α-sialon phosphor) + (mixing for molding) Mass ratio of metal oxide particles to 100% by mass of powder x true density of metal oxide particles) (2-1-1)

The apparent densities of the first sintered bodies 1 to 9 of Examples 1 to 9 and the first sintered bodies of Comparative Examples 1 to 5 were calculated by the following formula (3). Table 1 shows the mass (g) of each of the first sintered bodies of Examples 1 to 9 and the volume (cm ³ ) obtained by the Archimedes method.
Apparent density of the first sintered body = mass of the first sintered body ÷ volume of the first sintered body obtained by the Archimedes method (3)

Measurement of Relative Density of Second Sintered Body The relative density of the second sintered body 10 to 22 of Examples 10 to 22 was measured based on the following formulas (4) and (5). The results are shown in Table 1. The relative density was calculated by the following formula (4).
Relative density (%) = (apparent density of the second sintered body / true density of the second sintered body) x 100 (4)

The second method for calculating the true density of the sintered body is to add α to the mass ratio of α-alumina (specifically, α-alumina particles used in the powder mixing step) to 100% by mass of the mixed powder for the molded body. -The value obtained by multiplying the true density of alumina and the mass ratio of Ca-α-sialon phosphor particles to 100% by mass of the mixed powder for the molded product is multiplied by the true density of Ca-α-sialon phosphor particles. It is the sum of the values obtained. For the true density of the Ca-α-sialon phosphor and the true density of α-alumina, the same values as those used in the method for calculating the true density of the first sintered body were used.

The apparent density of the second sintered body was calculated by the following formula (5).
Apparent density of the second sintered body = mass of the second sintered body ÷ volume of the second sintered body obtained by the Archimedes method (5)

Measurement of Relative Emission Intensity A wavelength conversion member composed of the first sintered body of Examples 1 to 9, a wavelength conversion member composed of a second sintered body of Examples 10 to 22, and a first of Comparative Examples 1 to 5. The sintered body of No. 1 was cut to a thickness of 300 μm using a wire saw to form a sample. Using an LED chip made of a nitride semiconductor having an emission peak wavelength of 455 nm as a light source, a sample of a wavelength conversion member is irradiated with light from this light source, and the light from the light source is received from Examples 1 to 9 and Examples 10. The emission intensity of the emission peak wavelength in the wavelength range of 430 nm or more and 800 nm or less obtained from each sample of Comparative Examples 1 to 5 was measured using a spectrofluorometer. Emission peak in the wavelength range of 430 nm or more and 800 nm or less obtained from the sample of the wavelength conversion member of Example 1. Emission peak in the wavelength range of 430 nm or more and 800 nm or less obtained from each sample, where 100% is the emission intensity of the emission peak wavelength. The emission intensity of the wavelength was expressed as the relative emission intensity (%). The results of the wavelength conversion members of Examples 1 to 9 are shown in Table 1. The results of the wavelength conversion members of Examples 10 to 22 are shown in Table 2. The samples composed of the first sintered bodies of Comparative Examples 1 to 5 did not emit light even when irradiated with light from a light source. The results of the first sintered bodies of Comparative Examples 1 to 5 are shown in Table 3.

Appearance photograph An appearance photograph of the wavelength conversion member of Example 3 was obtained. FIG. 3 is an external photograph of a sample obtained by cutting the wavelength conversion member of Example 3 with a wire saw.
An external photograph of the wavelength conversion member of Example 12 was obtained. Example 12 is composed of a second sintered body obtained by secondary firing the first sintered body of Example 3. FIG. 4 is an external photograph of a sample obtained by cutting the wavelength conversion member of Example 12 with a wire saw.
An external photograph of the wavelength conversion member of Comparative Example 5 was obtained. FIG. 5 is an external photograph of a sample obtained by cutting the first sintered body of Comparative Example 5 with a wire saw.

The first sintered bodies 1 to 9 of Examples 1 to 9 and the second sintered bodies 10 to 22 of Examples 10 to 22 are 430 nm or more by irradiation with excitation light having an emission peak wavelength of 455 nm from a light source. It emitted light having an emission peak wavelength in a wavelength range of 800 nm or less, and could be used as a wavelength conversion member.

As shown in Table 1, in Examples 1 to 5, the content of the Ca-α-sialon phosphor was changed from 1% by mass to 20% by mass, and the primary firing temperature was set to 1500 ° C. for the first sintering. The bodies 1 to 5 are obtained and used as a wavelength conversion member. As shown in Table 1, the first sintered bodies 2 to 5 of Examples 2 to 5 have a high relative density of 92% or more and a Ca-α-sialon phosphor content of 1% by mass. The relative emission intensity was higher than that of the wavelength conversion member of Example 1.

As shown in Table 1, the wavelength conversion members according to Examples 6 to 9 have a Ca-α-sialon phosphor content of 5% by mass and a primary firing temperature in the range of 1400 ° C. or higher and 1600 ° C. or lower. It was changed to obtain the first sintered bodies 6 to 9 and used as a wavelength conversion member. As shown in Table 1, the wavelength conversion member of Example 6 has a primary firing temperature of 1400 ° C., a relative density of the first sintered body 6 of 84.5%, and a first sintered body. It is presumed that there is a void in 6. From this, the wavelength conversion member of Example 6 had a relative emission intensity of 36.9%. As shown in Table 1, the wavelength conversion member of Example 7 has a primary firing temperature of 1450 ° C. and a relative density of the first sintered body 7 of 87.2%. It was presumed that there were voids in the body 7. The wavelength conversion member of Example 7 had a relative density of 87.2% and was presumed to have voids, so that the relative emission intensity was 49.6%. As shown in Table 1, in the wavelength conversion member of Example 8, the temperature of the primary firing is 1550 ° C., the relative density of the first sintered body 8 is as high as 95.0%, the voids are suppressed, and the density is dense. As a result, the relative emission intensity was as high as 166.4%. Since the wavelength conversion member of Example 9 had a high primary firing temperature of 1600 ° C., the first sintered body 9 had a high relative density of 92.9%. When the temperature of the primary firing is high, the Ca-α-sialon phosphor, which is an oxynitride, reacts with the alumina particles, which are oxides, and the crystal structure of the Ca-α-sialon phosphor is partially decomposed. Was speculated.

As shown in Table 2, the wavelength conversion member according to Examples 10 to 14 is a second sintered body 10 obtained by secondary firing the first sintered bodies 1 to 5 at 1500 ° C. by HIP treatment. The wavelength conversion member according to Examples 11 to 14 has a relative emission intensity of 180% or more higher than that of the wavelength conversion member of Example 1, and is further densified by secondary firing by HIP treatment. It was.

As shown in Table 2, in Examples 10 to 22, except for Example 14, the second sintered bodies 10 to 13 and 15 to 22 are more than the first sintered bodies 1 to 4 and 6 to 9. Had a high relative density. In Example 14, the relative density of the second sintered body 14 is slightly smaller than that of the first sintered body 5, because the Ca-α-sialon fluorescence contained in the first sintered body 5 is slightly smaller. Since the content of the body is higher than that of the other examples, the closed pores contained in the first sintered body 5 are crushed and densified by the HIP treatment of the secondary firing, and Ca-α- It is considered that this is because the sialon phosphor is partially decomposed and evaporated to form open pores in the second sintered body 14. That is, in the second sintered body 14 of Example 14, the amount of open pores (open pores) generated by the HIP treatment is larger than the amount of closed pores (closed pores) crushed by the HIP treatment. Since it is slightly higher, it is considered that the relative density of the second sintered body 14 is slightly smaller than the relative density of the first sintered body 5.

As shown in Table 2, the wavelength conversion member according to Example 15 or 16 has a primary firing temperature of 1400 ° C. or 1450 ° C., and the relative density of the obtained first sintered body 6 or 7 is 90% or less. The relative density of the obtained second sintered body 15 or 16 was 89.0% or 91.7% even when the secondary firing by the HIP treatment was performed at 1500 ° C. From this, since the wavelength conversion member according to Example 15 or 16 has a low temperature for obtaining the first sintered body 6 or 7, the second sintering obtained even by performing secondary firing by HIP treatment. It was speculated that there were many voids in the body.

As shown in Table 2, in the wavelength conversion member according to Example 17, the primary firing temperature is as high as 1550 ° C., and the second sintered body 17 obtained by the secondary firing at 1500 ° C. by HIP treatment is the first. The relative density was higher than that of the sintered body 8. Since the primary firing temperature of the wavelength conversion member is as high as 1550 ° C., even if the secondary firing temperature is 1500 ° C., the Ca-α-sialon phosphor, which is an oxynitride, is an oxide at the stage of the primary firing. It is presumed that it is easy to react with the alumina particles, and that a small part of the crystal structure of the Ca-α-sialon phosphor is decomposed by the secondary firing. Therefore, even if the second sintered body is densified by the secondary firing by the HIP treatment to increase the transparency, the wavelength conversion member has a high temperature in the primary firing and therefore Ca-α- in the secondary firing. It is considered that the emission intensity may be lower than that of the first sintered body by decomposing a small part of the crystal structure of the Sialon phosphor.

As shown in Table 2, the wavelength conversion members according to Examples 18 to 20 have the secondary firing temperature changed in the range of 1400 ° C. or higher and 1550 ° C. or lower, and the secondary firing temperature is 1400 ° C. or Even if the temperature of the secondary firing is 1450 ° C., which is lower than the temperature of the primary firing, and the temperature of the secondary firing is 1550 ° C., which is higher than the temperature of the primary firing, a high relative density of 98.5% or more is obtained. It was possible to obtain 20 from the second sintered body 18 to have. The wavelength conversion member made of the second sintered body 18 or 19 had a relative emission intensity higher than 200%.

The wavelength conversion member according to Example 21 emitted light by irradiation with excitation light. In the wavelength conversion member according to Example 21, the temperature of the primary firing was 1600 ° C., and the relative emission intensity of the first sintered body 9 was 59.0%. When the temperature of the primary firing is high, the Ca-α-sialon phosphor, which is an oxynitride, may react with the alumina particles, which are oxides, and the crystal structure of the Ca-α-sialon phosphor may be partially decomposed. It was speculated that there was. Even if the wavelength conversion member was subjected to secondary firing by HIP treatment after primary firing, the relative emission intensity was lowered when a part of the crystal structure of the Ca-α-sialon phosphor was decomposed.

The wavelength conversion member according to Example 22 emitted light by irradiation with excitation light. In the wavelength conversion member according to Example 22, since the temperature of the secondary firing by the HIP treatment is as high as 1600 ° C., the Ca-α-sialon phosphor which is an acid nitride reacts with the alumina which is an oxide. It is presumed that the crystal structure of the Ca-α-sialon phosphor is partially decomposed, and the relative density is relatively high at 97.5%, but the relative emission intensity is 119.4%.

As shown in Table 3, the first sintered bodies according to Comparative Examples 1 to 5 in which the Ca-α-sialon phosphor was first fired together with an oxide other than alumina have a relative density of 71.0%. It was as follows, and did not emit light even when irradiated with excitation light.

The appearance of the wavelength conversion member according to Example 3 was bright orange as a whole, and the original body color of the Ca-α-sialon phosphor was maintained. As shown in FIG. 3, the appearance of the wavelength conversion member according to the third embodiment has no color unevenness and is a uniform color as a whole, and Ca-α-sialon contained in the wavelength conversion member by the primary firing. It was confirmed that the phosphor was not altered.

The appearance of the wavelength conversion member according to Example 12 was bright as a whole, darker orange than that of Example 3, and maintained the original body color of the Ca-α-sialon phosphor. The appearance of the wavelength conversion member according to the twelfth embodiment is brighter and darker orange than the appearance of the wavelength conversion member according to the third embodiment, which is the second sintered body 12 obtained by the secondary firing by the HIP treatment. It is probable that this is due to the progress of densification and the increase in transparency. As shown in FIG. 4, the appearance of the wavelength conversion member according to Example 12 has no color unevenness and is a homogeneous color as a whole, and Ca-α-sialon is obtained by primary firing and secondary firing by HIP treatment. It was confirmed that the phosphor was not altered.

The appearance of the first sintered body according to Comparative Example 5 was whitish and blackish in places as a whole, and did not maintain the orange color, which is the original body color of the Ca-α-sialon phosphor. As shown in FIG. 5, the appearance of the first sintered body according to Comparative Example 5 shows color unevenness that has changed to blackish in some places, and it is presumed that the Ca-α-sialon phosphor has been altered by the primary firing. It was.

In Examples 23 to 41, a wavelength conversion member made of a first sintered body containing a Ca-α-sialon phosphor, a YAG-based phosphor, and alumina was produced. Further, in Comparative Examples 6 to 9, a first sintered body containing a YAG-based phosphor and alumina and not containing a Ca-α-sialon phosphor was produced.

Manufacture of YAG phosphor Weigh yttrium oxide (Y ₂ O ₃ ), gadolinium oxide (Gd ₂ O ₃ ), cerium oxide (CeO ₂ ), and aluminum oxide (Al ₂ O ₃ ) so that they have the desired composition. And mixed to obtain a raw material mixture. Barium fluoride (BaF ₂ ) was added to the raw material mixture as the flux, and the raw material mixture and the flux were further mixed by a ball mill. This mixture was placed in an alumina crucible and heat-treated at 1500 ° C. for 10 hours in a reducing atmosphere to obtain a fired product. The calcined product is dispersed in pure water, and while vibrating through a sieve, a solvent (pure water) is allowed to flow through a wet sieve, then dehydrated, dried, and passed through a dry sieve for classification. Then, an yttrium aluminum garnet (hereinafter, also referred to as “YAG”) solvent was obtained. In Example 1, the average particle size (Fisher sub-sieve sizer's number) of the YAG phosphor was measured by the FSSS method in the same manner as the method of measuring the average particle size of the α-alumina particles. The average particle size of the YAG phosphor was 5 μm.

Composition analysis of YAG phosphor With respect to the obtained YAG phosphor, each element (Y) excluding oxygen constituting the YAG phosphor is used by ICP-AES (inductively coupled plasma emission spectrometer) (manufactured by Perkin Elmer). , Gd, Ce, Al) was measured, and the molar ratio of each element in the composition of the YAG phosphor was calculated from the value of the mass percentage of each element. The molar ratios of Y, Gd, and Ce were calculated with the measured molar ratio of Al as 5 and the molar ratio of Al being 5. The composition ratio of the YAG phosphor was (Y _0.575 Gd _0.400 Ce _0.025 ) ₃ Al ₅ O ₁₂ .

Example 23
Powder mixing step 10 parts by mass (for molding) of YAG phosphor represented by (Y _0.575 Gd _0.400 Ce _0.025 ) ₃ Al ₅ O ₁₂ having an average particle size of 5 μm measured by the obtained FSSS method. Ca-α-sialon phosphor with an average particle size of 13.0 μm measured by a laser diffraction-scattering particle size distribution measurement method (10% by mass based on 100% by mass of the mixed powder) (Product name: Aron Bright variety YL-600) , Denka Co., Ltd.) with 3 parts by mass (3% by mass of Ca-α-sialon phosphor with respect to 100% by mass of the mixed powder for molding) and an average particle size of 0.5 μm measured by the FSSS method. Weigh 87 parts by mass of α-alumina particles (product name: AA03, manufactured by Sumitomo Chemical Industries, Ltd., alumina purity 99.5% by mass) and mix them using a dairy pot and a dairy stick to prepare a mixed powder for a molded product. Got ready. In Tables 4 to 8, the content (mass%) of the Ca-α-sialon phosphor is the mass ratio of the Ca-α-sialon phosphor charged to 100% by mass of the mixed powder for the molded product. Further, in Tables 4 to 8, the content (mass%) of the YAG phosphor indicates the mass ratio of the YAG phosphor charged to 100 mass% of the mixed powder for the molded product. In Tables 4 to 8, the content of alumina particles in each Example and each Comparative Example is from 100% by mass of the mixed powder for a molded body to the content (% by mass) of Ca-α-sialon phosphor and YAG fluorescence. It is the balance obtained by subtracting the total amount of the body content (mass%).

Mold preparation step The mixed powder for the molded body was filled in a mold to form a cylindrical molded body having a diameter of 17.0 mm and a thickness of 10 mm at a pressure of 4.6 MPa (46.9 kgf / cm ² ). .. The obtained molded product was placed in a packaging container, vacuum-packed, and subjected to CIP treatment at 176 MPa using a cold isotropic pressure (CIP) device (manufactured by KOBELCO) as a pressure medium.

Primary firing step The obtained compact is held in a firing furnace (manufactured by Fuji Denpa Kogyo Co., Ltd.) in a nitrogen gas atmosphere (nitrogen: 99% by volume or more) at a temperature of 0.9 MPa and 1300 ° C. for 6 hours for primary firing. The first sintered body was obtained. The obtained first sintered body was used as a wavelength conversion member according to Example 23. In Examples 23 to 41, the content (mass%) of the Ca-α-sialon phosphor in the wavelength conversion member made of the first sintered body is Ca-α with respect to 100% by mass of the mixed powder for the molded product. -It is almost equal to the mass ratio of the charge of the Sialon phosphor, and the content (mass%) of the YAG phosphor is almost equal to the mass ratio of the charge of the YAG phosphor to 100 mass% of the mixed powder for the molded product. Further, in Comparative Examples 6 to 9, the content (mass%) of the YAG phosphor in the first sintered body is substantially the same as the mass ratio of the YAG phosphor charged to 100% by mass of the mixed powder for the molded product. equal.

Example 24
A first sintered body was obtained in the same manner as in Example 23 except that the firing temperature in the primary firing step was set to 1400 ° C., and the obtained first sintered body was subjected to wavelength conversion according to Example 24. It was used as a member.

Example 25
A first sintered body was obtained in the same manner as in Example 23 except that the firing temperature in the primary firing step was set to 1450 ° C., and the obtained first sintered body was subjected to wavelength conversion according to Example 25. It was used as a member.

Example 26
A first sintered body was obtained in the same manner as in Example 23 except that the firing temperature in the primary firing step was set to 1500 ° C., and the obtained first sintered body was subjected to wavelength conversion according to Example 26. It was used as a member.

Example 27
Same as in Example 25 except that a mixed powder for molding was prepared by mixing 5 parts by mass of a YAG phosphor, 1 part by mass of a Ca-α-sialon phosphor, and 94 parts by mass of α-alumina particles. The first sintered body was obtained, and the obtained first sintered body was used as the wavelength conversion member according to Example 27.

Example 28
The first sintered body was prepared in the same manner as in Example 27, except that the YAG phosphor was 5 parts by mass, the Ca-α-sialon phosphor was 3 parts by mass, and the α-alumina particles were 92 parts by mass. The obtained first sintered body was used as a wavelength conversion member according to Example 28.

Example 29
The first sintered body was prepared in the same manner as in Example 27, except that the YAG phosphor was 5 parts by mass, the Ca-α-sialon phosphor was 10 parts by mass, and the α-alumina particles were 85 parts by mass. The obtained first sintered body was used as a wavelength conversion member according to Example 29.

Example 30
Example 27 except that a mixed powder for molding was prepared by mixing the YAG phosphor with 5 parts by mass, the Ca-α-sialon phosphor with 20 parts by mass, and the α-alumina particles with 75 parts by mass. Similarly, a first sintered body was obtained, and the obtained first sintered body was used as a wavelength conversion member according to Example 30.

Comparative Example 6
A first sintered body was obtained in the same manner as in Example 27, except that the YAG phosphor was 5 parts by mass and the α-alumina particles were 95 parts by mass, and the obtained first sintered body was used. The wavelength conversion member according to Comparative Example 6 was used. The wavelength conversion member according to Comparative Example 6 does not contain a Ca-α-sialon phosphor.

Example 31
Example 25 except that a mixed powder for molding was prepared by mixing 10 parts by mass of the YAG phosphor, 1 part by mass of the Ca-α-sialon phosphor, and 89 parts by mass of the α-alumina particles. Similarly, a first sintered body was obtained, and the obtained first sintered body was used as a wavelength conversion member according to Example 31.

Example 32
The first sintered body was the same as in Example 31 except that the YAG phosphor was 10 parts by mass, the Ca-α-sialon phosphor was 10 parts by mass, and the α-alumina particles were 80 parts by mass. The obtained first sintered body was used as a wavelength conversion member according to Example 32.

Example 33
The first sintered body was prepared in the same manner as in Example 31 except that the YAG phosphor was 10 parts by mass, the Ca-α-sialon phosphor was 20 parts by mass, and the α-alumina particles were 70 parts by mass. The obtained first sintered body was used as a wavelength conversion member according to Example 33.

Comparative Example 7
A first sintered body was obtained in the same manner as in Example 31 except that the YAG phosphor was 10 parts by mass and the α-alumina particles were 90 parts by mass, and the obtained first sintered body was used. The wavelength conversion member according to Comparative Example 7 was used. The wavelength conversion member according to Comparative Example 7 does not contain a Ca-α-sialon phosphor.

Example 34
Example 25 except that a mixed powder for molding was prepared by mixing 20 parts by mass of the YAG phosphor, 1 part by mass of the Ca-α-sialon phosphor, and 79 parts by mass of the α-alumina particles. Similarly, a first sintered body was obtained, and the obtained first sintered body was used as a wavelength conversion member according to Example 34.

Example 35
Example 34 except that a mixed powder for molding was prepared by mixing 20 parts by mass of the YAG phosphor, 3 parts by mass of the Ca-α-sialon phosphor, and 77 parts by mass of the α-alumina particles. In the same manner, a first sintered body was obtained, and the obtained first sintered body was used as a wavelength conversion member according to Example 35.

Example 36
The first sintered body was the same as in Example 34, except that the YAG phosphor was 20 parts by mass, the Ca-α-sialon phosphor was 10 parts by mass, and the α-alumina particles were 70 parts by mass. The obtained first sintered body was used as a wavelength conversion member according to Example 36.

Example 37
The first sintered body was prepared in the same manner as in Example 34, except that the YAG phosphor was 20 parts by mass, the Ca-α-sialon phosphor was 20 parts by mass, and the α-alumina particles were 60 parts by mass. The obtained first sintered body was used as a wavelength conversion member according to Example 37.

Comparative Example 8
A first sintered body was obtained in the same manner as in Example 34, except that the YAG phosphor was 20 parts by mass and the α-alumina particles were 80 parts by mass, and the obtained first sintered body was used. The wavelength conversion member according to Comparative Example 8 was used. The wavelength conversion member according to Comparative Example 8 does not contain a Ca-α-sialon phosphor.

Example 38
Example 25 except that a mixed powder for molding was prepared by mixing 30 parts by mass of the YAG phosphor, 1 part by mass of the Ca-α-sialon phosphor, and 69 parts by mass of the α-alumina particles. Similarly, a first sintered body was obtained, and the obtained first sintered body was used as a wavelength conversion member according to Example 38.

Example 39
The first sintered body was prepared in the same manner as in Example 38, except that the YAG phosphor was 30 parts by mass, the Ca-α-sialon phosphor was 3 parts by mass, and the α-alumina particles were 67 parts by mass. The obtained first sintered body was used as a wavelength conversion member according to Example 39.

Example 40
The first sintered body was the same as in Example 38, except that the YAG phosphor was 30 parts by mass, the Ca-α-sialon phosphor was 10 parts by mass, and the α-alumina particles were 60 parts by mass. The obtained first sintered body was used as a wavelength conversion member according to Example 40.

Example 41
The first sintered body was prepared in the same manner as in Example 38, except that the YAG phosphor was 30 parts by mass, the Ca-α-sialon phosphor was 20 parts by mass, and the α-alumina particles were 50 parts by mass. The obtained first sintered body was used as a wavelength conversion member according to Example 41.

Comparative Example 9
A first sintered body was obtained in the same manner as in Example 38, except that the YAG phosphor was 30 parts by mass and the α-alumina particles were 70 parts by mass, and the obtained first sintered body was used. The wavelength conversion member according to Comparative Example 9 was used. The wavelength conversion member according to Comparative Example 9 does not contain a Ca-α-sialon phosphor.

Measurement of Relative Density of First Sintered Body In Examples 23 to 41 and Comparative Examples 6 to 9, the relative density of each first sintered body was measured based on the following formulas (1) to (3). Table 4 shows the relative densities of the first sintered bodies of Examples 23 to 26. Table 5 shows the relative densities of the first sintered bodies of Examples 27 to 30 and Comparative Example 6. Table 6 shows the relative densities of the first sintered bodies of Examples 31 to 33 and Comparative Example 7. Table 7 shows the relative densities of the first sintered bodies of Examples 34 to 37 and Comparative Example 8. Table 8 shows the relative densities of the first sintered bodies of Examples 38 to 41 and Comparative Example 9.
The relative density was measured by the following formula (1).
Relative density (%) = (apparent density of the first sintered body / true density of the first sintered body) x 100 (1)

The true density of the first sintered body was calculated from the following formula (2-2). The true density of the α-alumina particles used in each Example and Comparative Example was 3.98 g / cm ³ . The true density of the Ca-α-sialon phosphor was 3.22 g / cm ³ . The true density of the YAG phosphor was 4.77 g / cm ³ . The true density of the YAG phosphor was measured using a dry automatic density meter (trade name: Accubic 1330, manufactured by Shimadzu Corporation).
True density of the first sintered body = (mass ratio of Ca-α-sialon phosphor to 100% by mass of mixed powder for molded body × true density of Ca-α-sialon phosphor) + (for molded body Mass ratio of YAG phosphor to 100 mass% of mixed powder × true density of YAG phosphor) + (mass ratio of alumina particles to 100 mass% of mixed powder for molded product × true density of alumina particles) (2-2 )

The apparent density of the first sintered body was calculated by the following formula (3).
Apparent density of the first sintered body = mass of the first sintered body ÷ volume of the first sintered body obtained by the Archimedes method (3)

Measurement of Relative Emission Intensity and Saturation A wavelength conversion member made of the first sintered body of each Example and Comparative Example was cut to a thickness of 300 μm using a wire saw to form a sample. Using an LED chip made of a nitride semiconductor having an emission peak wavelength of 455 nm as a light source, a sample of a wavelength conversion member is irradiated with light from this light source, and the light from the light source is received to obtain 430 nm or more and 800 nm from each sample. The emission intensity and chromaticity (x value, y value in CIE chromaticity coordinates) of the emission peak wavelength in the following wavelength range were measured using a spectral fluorometer. Among the wavelength conversion members having a relative density of more than 90%, the blue light emitted from the light source was transmitted. The chromaticity of Examples 23 to 41 and Comparative Examples 6 to 9 was measured by excluding the emission spectrum of blue light in the range of 490 nm or less from the emission spectra in the wavelength range of 430 nm or more and 800 nm or less obtained from each sample. The chromaticity (x value, y value).

Table 4 shows the relative emission intensity and chromaticity (x value, y value) of the first sintered body which is the wavelength conversion member according to Examples 23 to 26. Among the first sintered bodies of Examples 23 to 26, the emission intensity of the first sintered body of Example 25 having a relative density closest to the value of 90% is set to 100%, and Examples 23 to 26 The emission intensity of the first sintered body was expressed as the relative emission intensity (%).

Table 5 shows the relative emission intensity and chromaticity (x value, y value) of the first sintered body in the wavelength conversion member according to Examples 27 to 30 and Comparative Example 6. Among the first sintered bodies of Examples 27 to 30 and Comparative Example 6, the emission intensity of the first sintered body of Example 30 whose relative density is closest to the value of 90% is set to 100%, and Examples are used. The emission intensities of the first sintered bodies of 27 to 30 and Comparative Example 6 were expressed as relative emission intensities (%).

Table 6 shows the relative emission intensity and chromaticity (x value, y value) of the first sintered body which is the wavelength conversion member according to Examples 31 to 33 and Comparative Example 7. Among the first sintered bodies of Examples 31 to 33 and Comparative Example 7, the emission intensity of the first sintered body of Example 33, which is closest to the value of 90% in relative density, is set to 100%, and Examples are used. The emission intensities of the first sintered bodies of 31 to 33 and Comparative Example 7 were expressed as relative emission intensities (%).

Table 7 shows the relative emission intensity and chromaticity (x value, y value) of the first sintered body which is the wavelength conversion member according to Examples 34 to 37 and Comparative Example 8. Among the first sintered bodies of Examples 34 to 37 and Comparative Example 8, the emission intensity of the first sintered body of Example 37, which has the closest relative density to the value of 90%, is set to 100%, and Examples are used. The emission intensities of the first sintered bodies of 34 to 37 and Comparative Example 8 were expressed as relative emission intensities (%).

Table 8 shows the relative emission intensity and chromaticity (x value, y value) of the first sintered body which is the wavelength conversion member according to Examples 38 to 41 and Comparative Example 9. Among the first sintered bodies of Examples 38 to 41 and Comparative Example 9, the emission intensity of the first sintered body of Example 40, which has the closest relative density to the value of 90%, is set to 100%, and Examples are used. The emission intensities of the first sintered bodies of 38 to 41 and Comparative Example 9 were expressed as relative emission intensities (%).

FIG. 6 is a diagram in which the chromaticity (x value, y value) of the wavelength conversion member made of the first sintered body according to Examples 23 to 26 is plotted on the CIE chromaticity coordinates. FIG. 7 shows the chromaticity (x value, y value) of the wavelength conversion member made of the first sintered body according to Examples 27 to 30 and the first sintered body of Comparative Example 6 on the CIE chromaticity coordinates. It is a plotted figure.

As shown in Table 4, the wavelength conversion members according to Examples 23 to 26 are composed of a first sintered body obtained by changing the temperature of the primary firing from 1300 ° C. to 1500 ° C., and the temperature of the primary firing is high. The higher the value, the higher the relative density and the higher the relative emission intensity.

As shown in Table 4 and FIG. 6, the wavelength conversion member according to Example 26 had a chromaticity shifted to the shorter wavelength side as compared with the wavelength conversion member according to Examples 23 to 25. Since the wavelength conversion member of Example 26 has a high relative density of 93.1%, the blue light emitted from the light source was clearly transmitted. The chromaticity x value and y value of each embodiment shown in FIG. 6 are chromaticity measured excluding the blue light emitted from the light source, but the chromaticity of the wavelength conversion member of Example 26 moves toward the short wavelength side. Because the primary firing temperature was relatively high at 1500 ° C, the crystal structure of the Ca-α-sialon phosphor was partially decomposed and deteriorated by a compound containing, for example, fluorine contained in a trace amount in the YAG phosphor. , It was presumed that only the YAG phosphor emitted light by irradiation with the excitation light.

As shown in Table 5, in the wavelength conversion members according to Examples 27 to 30, when the content of the YAG phosphor is 5% by mass, the Ca-α-sialon phosphor is in the range of 1 to 10% by mass. As it increased, the relative density and relative emission intensity increased. Like the wavelength conversion member according to Examples 27 to 30, the total content of the Ca-α-sialon phosphor and the YAG phosphor is in the range of 0.1% by mass or more and 70% by mass or less, and Ca-α- When the content of the sialon phosphor is in the range of 0.1% by mass or more and 40% by mass or less, the relative density is 80% or more and the emission peak wavelength is 455 nm or more and 430 nm or more and 800 nm or less by irradiation with excitation light. It emitted light having an emission peak wavelength in the wavelength range and could be used as a wavelength conversion member.

As shown in Tables 5 and 7, the wavelength conversion member according to Examples 27 to 30 has an emission peak wavelength in a wavelength range of 430 nm or more and 800 nm or less by irradiation with excitation light having an emission peak wavelength of 455 nm. It could be used as a wavelength conversion member that emits light having a chromaticity on the long wavelength side as compared with Comparative Example 6 and emits light in a desired color tone.

Since the wavelength conversion member of Comparative Example 6 has a high relative density of 90.3%, the blue light emitted from the light source was clearly transmitted. The chromaticity x value and y value of each Example and Comparative Example shown in Table 5 and FIG. 7 are the chromaticity measured excluding the blue light emitted from the light source, but the first sintering of Comparative Example 6 Since the body does not contain a Ca-α-sialon phosphor, the chromaticity (x value, y value) on the short wavelength side is compared with the wavelength conversion member made of the first sintered body according to Examples 27 to 30. ) Light was emitted.

As shown in Table 6, the wavelength conversion member according to Examples 31 to 33 has a Ca-α-sialon phosphor in the range of 1 to 20% by mass when the content of the YAG phosphor is 10% by mass. As it increased, the relative density and relative emission intensity increased. Like the wavelength conversion members according to Examples 31 to 33, the total content of the Ca-α-sialon phosphor and the YAG phosphor is in the range of 0.1% by mass or more and 70% by mass or less, and Ca-α-. When the content of the sialon phosphor is in the range of 0.1% by mass or more and 40% by mass or less, the relative density is 80% or more and the emission peak wavelength is 455 nm or more and 430 nm or more and 800 nm or less by irradiation with excitation light. It could be used as a wavelength conversion member that emits light having an emission peak wavelength in the wavelength range, emits light having a chromaticity on the longer wavelength side as compared with Comparative Example 7, and emits light in a desired color tone.

As shown in Table 6, since the first sintered body of Comparative Example 7 does not contain the Ca-α-sialon phosphor, the wavelength conversion member made of the first sintered body according to Examples 31 to 33. Compared with this, light having a chromaticity (x value, y value) on the short wavelength side was emitted.

As shown in Table 7, in the wavelength conversion members according to Examples 34 to 37, when the content of the YAG phosphor is 20% by mass, the Ca-α-sialon phosphor is in the range of 1 to 10% by mass. As it increased, the relative density and relative emission intensity increased. Like the wavelength conversion members according to Examples 34 to 37, the total content of the Ca-α-sialon phosphor and the YAG phosphor is in the range of 0.1% by mass or more and 70% by mass or less, and Ca-α-. When the content of the sialon phosphor is in the range of 0.1% by mass or more and 40% by mass or less, the relative density is 80% or more and the emission peak wavelength is 455 nm or more and 430 nm or more and 800 nm or less by irradiation with excitation light. It could be used as a wavelength conversion member that emits light having an emission peak wavelength in the wavelength range, emits light having a chromaticity on the longer wavelength side as compared with Comparative Example 8, and emits light in a desired color tone.

As shown in Table 7, since the first sintered body of Comparative Example 8 does not contain the Ca-α-sialon phosphor, the wavelength conversion member made of the first sintered body according to Examples 34 to 37. Compared with this, light having a chromaticity (x value, y value) on the short wavelength side was emitted.

As shown in Table 8, in the wavelength conversion members according to Examples 38 to 41, when the content of the YAG phosphor is 30% by mass, the Ca-α-sialon phosphor is in the range of 1 to 10% by mass. As it increased, the relative density increased. Further, the wavelength conversion member according to Examples 38 to 41 has a relative emission intensity when the Ca-α-sialon phosphor increases in the range of 1 to 20% by mass when the content of the YAG phosphor is 30% by mass. Became higher. Like the wavelength conversion members according to Examples 38 to 41, the total content of the Ca-α-sialon phosphor and the YAG phosphor is in the range of 0.1% by mass or more and 70% by mass or less, and Ca-α-. When the content of the sialon phosphor is in the range of 0.1% by mass or more and 40% by mass or less, the relative density is 80% or more and the emission peak wavelength is 455 nm or more and 430 nm or more and 800 nm or less by irradiation with excitation light. It can be used as a wavelength conversion member that has an emission peak wavelength in the wavelength range, emits light having a chromaticity on the longer wavelength side as compared with Comparative Example 9, and emits light in a desired color tone.

As shown in Table 8, since the first sintered body of Comparative Example 9 does not contain the Ca-α-sialon phosphor, the wavelength conversion member composed of the first sintered body according to Examples 38 to 41. Compared with this, light having a chromaticity (x value, y value) on the short wavelength side was emitted.

The wavelength conversion member according to the present disclosure can be used as a material for a wavelength conversion member and a solid scintillator capable of emitting light by irradiation with excitation light and converting the wavelength of light emitted from an LED or LD.

Claims (14)

A molded product obtained by molding a mixed powder containing a Ca-α-sialon phosphor having a composition represented by the following composition formula and alumina particles is prepared, and the molded product is placed in a range of 1000 ° C. or higher and 1600 ° C. or lower. Including primary firing at the temperature of to obtain the first sintered body,
In the mixed powder, the content of the Ca-α-sialon phosphor is in the range of 0.1% by mass or more and 40% by mass or less with respect to 100% by mass of the mixed powder, and the mixed powder 100 Manufacture of a wavelength conversion member in which the balance excluding the Ca-α-sialon phosphor from mass% is the alumina particles, and the content of the alumina particles is in the range of 60 mass% or more and 99.9 mass% or less. Method.
Ca _k Si _{12- (m + n)} Al _{m + n On} N _16-n : Eu
(In the composition formula , k , m, and n are numbers that satisfy 0 <k ≦ 2.0, 2.0 ≦ m ≦ 6.0, and 0 ≦ n ≦ 1.0.) To prepare a molded product obtained by molding a mixed powder containing a Ca-α-sialon phosphor having a composition represented by the following composition formula , alumina particles, and yttrium aluminum garnet-based phosphor, and the molded product. Including primary firing at a temperature in the range of 1000 ° C. or higher and 1500 ° C. or lower to obtain a first sintered body.
In the mixed powder, the content of the Ca-α-sialon phosphor is in the range of 0.1% by mass or more and 40% by mass or less with respect to 100% by mass of the mixed powder, and the Ca-α- The total amount of the sialon phosphor and the yttrium aluminum garnet-based phosphor is in the range of 0.1% by mass or more and 70% by mass or less, and the content of the Ca-α-sialon phosphor is from 100% by mass of the mixed powder. A method for producing a wavelength conversion member, wherein the balance excluding the yttrium aluminum garnet-based phosphor is the alumina particles, and the content of the alumina particles is in the range of 30% by mass or more and 99.9% by mass or less.
Ca _k Si _{12- (m + n)} Al _{m + n On} N _16-n : Eu
(In the composition formula , k , m, and n are numbers that satisfy 0 <k ≦ 2.0, 2.0 ≦ m ≦ 6.0, and 0 ≦ n ≦ 1.0.) A claim comprising obtaining a second sintered body by secondary firing the first sintered body at a temperature in the range of 1000 ° C. or higher and 1600 ° C. or lower by hot isotropic pressure pressurization (HIP) treatment. The method for manufacturing a wavelength conversion member according to 1. A claim comprising obtaining a second sintered body by secondary firing the first sintered body at a temperature in the range of 1000 ° C. or higher and 1500 ° C. or lower by hot isotropic pressure pressurization (HIP) treatment. 2. The method for manufacturing a wavelength conversion member according to 2. The method for manufacturing a wavelength conversion member according to claim 1 or 3, wherein the temperature of the primary firing is in the range of 1200 ° C. or higher and 1570 ° C. or lower. The method for manufacturing a wavelength conversion member according to claim 2 or 4, wherein the temperature of the primary firing is in the range of 1200 ° C. or higher and 1450 ° C. or lower. The method for manufacturing a wavelength conversion member according to any one of claims 1 to 6, wherein the average particle size of the Ca-α-sialon phosphor is in the range of 2 μm or more and 30 μm or less. The method for manufacturing a wavelength conversion member according to any one of claims 1 to 7, wherein the average particle size of the alumina particles is in the range of 0.1 μm or more and 1.3 μm or less. The method for producing a wavelength conversion member according to any one of claims 1 to 8, wherein the alumina purity of the alumina particles in the mixed powder is 99.0% by mass or more. The method for manufacturing a wavelength conversion member according to any one of claims 1 to 9, wherein the relative density of the first sintered body is 80% or more. The method for manufacturing a wavelength conversion member according to claim 3 or 4, wherein the relative density of the second sintered body is 90% or more. It contains a Ca-α-sialon phosphor having a composition represented by the following composition formula and alumina, and the content of the Ca-α-sialon phosphor is in the range of 0.1% by mass or more and 40% by mass or less. A wavelength conversion member in which the balance is the alumina and voids.
Ca _k Si _{12- (m + n)} Al _{m + n On} N _16-n : Eu
(In the composition formula , k , m, and n are numbers that satisfy 0 <k ≦ 2.0, 2.0 ≦ m ≦ 6.0, and 0 ≦ n ≦ 1.0.) It contains a Ca-α-sialon phosphor having a composition represented by the following composition formula , alumina, and an yttrium aluminum garnet-based phosphor, and the content of the Ca-α-sialon phosphor is 0.1% by mass. The total content of the yttrium aluminum garnet-based phosphor and the Ca-α-sialon phosphor is 0.1% by mass or more and 70% by mass or less, and the balance is the alumina. And a wavelength conversion member that is a void.
Ca _k Si _{12- (m + n)} Al _{m + n On} N _16-n : Eu
(In the composition formula , k, m, and n are numbers that satisfy 0 <k ≦ 2.0, 2.0 ≦ m ≦ 6.0, and 0 ≦ n ≦ 1.0.) The wavelength conversion member according to claim 12 or 13, wherein the relative density is 80% or more.