Sintered body and light-emitting device

Abstract

The invention provides a sintered body and a light-emitting device. The sintered body contains at least one phosphor selected from the group consisting of nitride phosphors having a composition represented by formula (I) and alpha-sialon phosphors having a composition represented by formula (II), and in a chromaticity diagram of the CIE1931 color system, a region A1 is defined by a line connecting a 1a-th point (x = 0.549, y = 0.425), a 2a-th point (x = 0.562, y = 0.438), a 3a-th point (x = 0.589, y = 0.411), and a 4a-th point (x = 0.576, y = 0.407). The sintered body emits light having a hue within the region A1 when irradiated with excitation light, and the light emitted when irradiated with excitation light includes light obtained by wavelength conversion of excitation light by a phosphor included in the sintered body and excitation light that has passed through the sintered body. The ratio (Z2 / Z1) of the integral value of a second integral value (Z2) of 400-500 nm inclusive to a first integral value (Z1) of more than 500 nm and 800 nm or less in the emission spectrum of light emitted from the sintered body is 0.005 or more.

Description

Technical Field

[0001] The present invention relates to a sintered body and a light-emitting device. Background Art

[0002] Regarding light-emitting devices using light-emitting elements such as LEDs and LDs, there are light-emitting devices that are composed of a light-emitting element as an excitation light source and a member including a phosphor that absorbs part of the light from the light-emitting element and converts it into a different wavelength. The light-emitting device emits mixed color light of the light emitted from the light-emitting element and the light emitted from the phosphor. Such light-emitting devices are used for vehicle-mounted use, general lighting, backlights of liquid crystal display devices, lighting, light sources for projectors, etc.

[0003] As a member containing a phosphor, Patent Document 1 discloses a sintered body containing a fluoride inorganic binder and a nitride phosphor.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2016 / 117623 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the case of a sintered body containing a fluoride inorganic binder and a nitride phosphor, the fluoride inorganic binder and the nitride phosphor may react during sintering. The luminous flux of light emitted by the sintered body containing the nitride phosphor that has reacted with the fluoride inorganic binder when irradiated with excitation light may sometimes decrease, and the luminescence characteristics may be reduced.

[0009] An object of the present application is to provide a sintered body that emits light having a high luminous flux when irradiated with excitation light, and a light-emitting device using the sintered body.

[0010] Solutions to the problem

[0011] The first aspect relates to a sintered body comprising at least one phosphor selected from a nitride phosphor having a composition represented by the following formula (I) and an α-sialon phosphor having a composition represented by the following formula (II).

[0012] In the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) are (x=0.549, y=0.425) as point 1a, (x=0.562, y=0.438) as point 2a, (x=0.589, y=0.411) as point 3a, and (x=0.576, y=0.407) as point 4a. An area A1 is defined by a first straight line connecting point 1a and point 2a, a second straight line connecting point 2a and point 3a, a third straight line connecting point 3a and point 4a, and a fourth straight line connecting point 4a and point 1a. When the sintered body is irradiated with excitation light, light having a hue within the area A1 is emitted.

[0013] The sintered body has a peak emission wavelength of 450nm and an output of 1300mW / mm 2 Above and 6000mW / mm 2 The excitation light emitted from the sintered body includes light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the second integral value Z2 in the wavelength range of 400 nm to 500 nm to the first integral value Z1 in the wavelength range of more than 500 nm and less than 800 nm in the emission spectrum of the light emitted from the sintered body is 0.005 or more,

[0014] (Ba 1-u-w M 1 u M 2 w )2Si5N8(I)

[0015] In the above formula (I), M 1 is at least one element selected from Sr, Ca and Mg, M 2 is at least one element selected from Eu, Ce, Tb and Mn, and u and w satisfy 0<u≤0.5, 0.001≤w<0.5, respectively,

[0016] M 3 q Si 12-(r+s) Al r+s O s N 16-s :Eu t (II)

[0017] In the above formula (II), M 3It is at least one element selected from Li, Mg, Ca, Sr, Y and lanthanide elements, the lanthanide elements do not include La and Ce, and q, r, s and t respectively satisfy 0<q≤2.0, 2.0≤r≤6.0, 0≤s≤1.0, 0.001≤t≤0.5.

[0018] A second aspect relates to a light emitting device comprising:

[0019] an excitation light source that emits light having a peak emission wavelength in a range of 380 nm to 570 nm, and

[0020] The sintered body is arranged at a position where light is irradiated from the excitation light source.

[0021] Effects of the Invention

[0022] According to the present application, it is possible to provide a sintered body that emits light having a high luminous flux by irradiation with excitation light, and a light-emitting device using the sintered body. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a diagram showing an example of a light emission spectrum of light emitted from a sintered body when irradiated with excitation light.

[0024] Figure 2 This is a diagram showing region A satisfying the amber color requirement in the ECE standard in the chromaticity diagram of the CIE 1931 color system.

[0025] Figure 3 This is a diagram showing a light-emitting region A1 of a sintered body after being irradiated with excitation light in a chromaticity diagram of the CIE1931 color system.

[0026] Figure 4 This is a diagram showing a light-emitting area A2 of the sintered body after being irradiated with excitation light in the chromaticity diagram of the CIE1931 color system.

[0027] Figure 5 This is a diagram showing a light-emitting area A3 of the sintered body after being irradiated with excitation light in the chromaticity diagram of the CIE1931 color system.

[0028] Figure 6 This is a diagram showing area A, area A1, area A2, and area A3 in the chromaticity diagram of the CIE1931 color system.

[0029] Figure 7 1 is a schematic plan view showing an example of a light emitting device.

[0030] Figure 8 1 is a schematic cross-sectional view showing an example of a light emitting device.

[0031] Fig. 9: is a SEM photograph showing the nitride phosphor 5.

[0032] Fig.10 It is a diagram showing the chromaticity coordinates (x, y) of the light emitted by the regions A1, A2, and A3 and the sintered bodies of Examples 1-1 to 1-3 in the chromaticity diagram of the CIE1931 color system.

[0033] Fig.11 It is a diagram showing the chromaticity coordinates (x, y) of the light emitted by regions A1, A2 and A3, each light-emitting device using the sintered bodies of Examples 2-1 to 2-5, and each light-emitting device using the sintered bodies of Comparative Example 2-6 in the chromaticity diagram of the CIE1931 color system.

[0034] Fig.12 This is a diagram showing the chromaticity coordinates (x, y) of the light emitted by the light-emitting devices using the sintered bodies of Examples 3-1 to 3-3 in the regions A1, A2, and A3 in the chromaticity diagram of the CIE1931 color system.

[0035] Fig.13 It is a diagram showing the chromaticity coordinates (x, y) of the light emitted by regions A1, A2 and A3, each light-emitting device using the sintered bodies of Examples 4-1 to 4-3, and each light-emitting device using the sintered bodies of Comparative Examples 4-4 to 4-5 in the chromaticity diagram of the CIE1931 color system.

[0036] Fig.14 It is a diagram showing the chromaticity coordinates (x, y) of the light emitted by the light-emitting devices using the sintered bodies of Examples 5-1 to 5-4, and regions A1, A2, and A3 in the chromaticity diagram of the CIE1931 color system.

[0037] Fig.15 This is a SEM photograph of the fracture surface of the sintered body of Example 5-1.

[0038] Fig.16 It is a diagram showing the chromaticity coordinates (x, y) of the light emitted by the light-emitting devices using the sintered bodies of Examples 6-1 to 6-4, and regions A1, A2, and A3 in the chromaticity diagram of the CIE1931 color system.

[0039] Explanation of symbols

[0040] 1: substrate, 10: light emitting element, 11: semiconductor element, 51: wavelength conversion member, 61: conductive member, 80: adhesive layer, 90: covering member, 100: light emitting device. DETAILED DESCRIPTION

[0041] The sintered body and the light-emitting device of the present application are described below. However, the embodiments shown below are examples for concretizing the technical ideas of the present invention, and the present invention is not limited to the following sintered body and the light-emitting device. It should be noted that the relationship between the color name and the chromaticity coordinates, the relationship between the wavelength range of light and the color name of monochromatic light, etc. follow JIS Z 8110.

[0042] The sintered body comprises at least one phosphor selected from a nitride phosphor having a composition represented by formula (I) and an α-sialon phosphor having a composition represented by formula (II), wherein in the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) are (x=0.549, y=0.425) as the 1a point, (x=0.562, y=0.438) as the 2a point, (x=0.589, y=0.411) as the 3a point, and (x=0.576, y=0.407) is set as point 4a, and area A1 is defined by the first straight line connecting point 1a and point 2a, the second straight line connecting point 2a and point 3a, the third straight line connecting point 3a and point 4a, and the fourth straight line connecting point 4a and point 1a. The sintered body has a color tone within the range of area A1 when irradiated with excitation light. The sintered body has a peak emission wavelength of 450nm and an output of 1300mW / mm 2 Above and 6000mW / mm 2 When the excitation light is within the following range, the excitation light emitted includes light obtained after the excitation light is converted into light by the phosphor contained in the sintered body and light obtained by passing through the sintered body, and the integral value ratio Z2 / Z1 of the second integral value Z2 of the light emitted from the sintered body in the wavelength range of greater than 400nm and less than 500nm in the emission spectrum to the first integral value Z1 in the wavelength range of greater than 500nm and less than 800nm ​​is greater than 0.005.

[0043] The sintered body emits light with a peak wavelength of 450nm and an output of 1300mW / mm 2 Above and 6000mW / mm 2 When the excitation light is within the following range, the sintered body emits light including light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and light of the excitation light after passing through the sintered body. In the emission spectrum of the light emitted from the sintered body, the emission spectrum in the wavelength range of more than 500nm and less than 800nm ​​represents the emission spectrum of the light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body when the excitation light is irradiated, and the emission spectrum in the wavelength range of more than 400nm and less than 500nm represents the emission spectrum of the excitation light after passing through the sintered body. The sintered body emits light with a peak wavelength of 450nm and an output of 1300mW / mm 2 Above and 6000mW / mm2 When the excitation light is in the following range, the following light is emitted: the integral value ratio Z2 / Z1 of the second integral value Z2 of the light emitted from the sintered body in the wavelength range of 400nm to 500nm in the emission spectrum relative to the first integral value Z1 in the wavelength range of more than 500nm and less than 800nm ​​is 0.005 or more. The sintered body after irradiation with the excitation light can emit light having a hue within the region A1 and a high luminous flux, including light obtained after the excitation light is converted by the phosphor contained in the sintered body and light dispersed in the sintered body by the excitation light irradiated to the sintered body and detached from the sintered body. The reason why the sintered body after irradiation with the excitation light can emit light having a high luminous flux and an integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum of 0.005 or more is presumably because the phosphor particles in the sintered body become larger, thereby reducing the interface in the sintered body formed by the phosphor particles, thereby improving the light extraction efficiency.

[0044] The sintered body emits light with a peak wavelength of 450nm and an output of 1300mW / mm 2 Above and 6000mW / mm 2 When the excitation light is within the following range, the light emitted includes light obtained after the excitation light is converted in wavelength by the fluorescent material contained in the sintered body and the excitation light after passing through the sintered body. Preferably, light is emitted in which the integral value ratio Z2 / Z1 of the second integral value Z2 in the wavelength range of greater than 400nm and less than 500nm to the first integral value Z1 in the wavelength range of greater than 500nm and less than 800nm ​​in the luminescence spectrum of the light emitted from the sintered body is greater than 0.008, more preferably, light is emitted in which Z2 / Z1 is greater than 0.009, and even more preferably, light is emitted in which Z2 / Z1 is greater than 0.01. When irradiated with the above-mentioned excitation light, the sintered body may emit light having an integral value ratio Z2 / Z1 of 0.04 or less in the emission spectrum of the light emitted from the sintered body, preferably light having a range of Z2 / Z1 of 0.005 or more and 0.04 or less, more preferably light having a range of Z2 / Z1 of 0.008 or more and 0.04 or less, and further preferably light having a range of Z2 / Z1 of 0.01 or more and 0.04 or less. When irradiated with the above-mentioned excitation light, the sintered body may emit light having an integral value ratio Z2 / Z1 of 0.03 or less in the emission spectrum of the light emitted from the sintered body, or light having a Z2 / Z1 of 0.02 or less. If, when irradiated with the above-mentioned excitation light, the sintered body emits light having an integral value ratio Z2 / Z1 of 0.04 or less in the emission spectrum of the light emitted from the sintered body, the excitation light on the short wavelength side after passing through the sintered body becomes excessive, and light having a hue not in the region A1 is emitted from the sintered body.

[0045] Figure 1The sintered body was irradiated with a light emitting device having a peak wavelength of 450 nm and an output of 1300 mW / mm 2 Above and 6000mW / mm 2 A diagram showing an example of a luminescence spectrum of light emitted from a sintered body when excitation light is within the following range, wherein the light emitted from the sintered body includes light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and the excitation light after passing through the sintered body.

[0046] exist Figure 1 In the luminescence spectrum of light emitted from the sintered body when irradiated with excitation light, the first integral value Z1 in the wavelength range exceeding 500nm and below 800nm ​​is the integral value of the wavelength width range surrounded by the horizontal axis with the luminescence intensity (au (arbitrary value)) being 0 (zero) and the luminescence spectrum of the sintered body in the wavelength range exceeding 500nm and below 800nm. The light emitted from the sintered body includes the light obtained after the excitation light is wavelength-converted by the phosphor contained in the sintered body and the excitation light after passing through the sintered body. Figure 1 In the luminescence spectrum of the light emitted from the sintered body shown, the second integral value Z2 in the wavelength range of 400 nm to 500 nm is the integral value of the wavelength width range surrounded by the horizontal axis with luminescence intensity (au) of 0 and the luminescence spectrum of the light emitted from the sintered body in the range of 400 nm to 500 nm. In the luminescence spectrum of the light emitted from the sintered body when irradiated with excitation light, when the luminescence spectrum of the light emitted from the sintered body in the wavelength range of more than 500 nm to less than 800 nm does not touch the horizontal axis with luminescence intensity of 0, the integral value of the wavelength width range surrounded by a straight line extending perpendicularly from the wavelength 500 nm to the horizontal axis with luminescence intensity of 0, a straight line extending perpendicularly from the wavelength 800 nm to the horizontal axis with luminescence intensity of 0, the horizontal axis with luminescence intensity of 0, and the luminescence spectrum of the light emitted from the sintered body in the wavelength range of more than 500 nm to less than 800 nm is set as Z1. In the luminescence spectrum of light emitted from the sintered body when irradiated with excitation light, when the luminescence spectrum of light emitted from the sintered body in the wavelength range of greater than 400nm and less than 500nm is not connected to the horizontal axis with a luminescence intensity of 0, the integral value of the wavelength width range surrounded by a straight line stretched vertically from a wavelength of 400nm relative to the horizontal axis with a luminescence intensity of 0, a straight line stretched vertically from a wavelength of 500nm relative to the horizontal axis with a luminescence intensity of 0, the horizontal axis with a luminescence intensity of 0, and the luminescence spectrum of light emitted from the sintered body in the wavelength range of greater than 400nm and less than 500nm is set to Z2.

[0047] In the chromaticity diagram of the CIE (Commission Internationale de l'Eclairage: International Commission on Illumination) 1931 color system, region A1 is light having a hue within region A that satisfies the amber (orange) color requirement specified in the ECE (United Nations Economic Commission for Europe: United Nations Economic Commission for Europe) standard. It should be noted that in this specification, amber includes orange. Light having a hue within region A that satisfies the amber color requirement specified in the ECE standard is emitted from a direction indicator (turn signal lamp, warning flasher) in a vehicle lamp such as a rear combination lamp mounted on a vehicle. Area A that meets the amber requirements specified by the ECE standard is area A in the chromaticity diagram of the CIE1931 color system, and the above-mentioned area A is defined by the 1as point (x=0.545, y=0.425), the 2as point (x=0.560, y=0.440), the 3as point (x=0.609, y=0.390), the 4as point (x=0.597, y=0.390), the 1s straight line connecting the 1as point and the 2as point, the 2s straight line connecting the 2as point and the 3as point, the 3s straight line connecting the 3as point and the 4as point, and the 4s straight line connecting the 4as point and the 1as point. Figure 2 The area A that satisfies the amber color requirement specified in the ECE standard in the chromaticity diagram of the CIE 1931 color system is shown. Table 1 shows the chromaticity coordinates of the 1st as point, the 2nd as point, the 3rd as point, and the 4th as point representing the area A.

[0048] [surface

[0049]

[0050] When the sintered body is irradiated with excitation light, it emits light including light obtained after the wavelength of the excitation light is converted by the fluorescent material contained in the sintered body and light after the excitation light passes through the sintered body. The light emitted from the sintered body has a hue within area A1 in the chromaticity diagram of the CIE1931 color system, and the chromaticity coordinates (x, y) are (x=0.549, y=0.425) as point 1a, (x=0.562, y=0.438) as point 2a, (x=0.589, y=0.411) as point 3a, and (x=0.576, y=0.407) as point 4a. The above-mentioned area A1 is defined by the first straight line connecting point 1a and point 2a, the second straight line connecting point 2a and point 3a, the third straight line connecting point 3a and point 4a, and the fourth straight line connecting point 4a and point 1a. Figure 3The area A1 is shown in the chromaticity diagram of the CIE 1931 color system. Table 2 shows the chromaticity coordinates of the point 1a, the point 2a, the point 3a, and the point 4a representing the area A1.

[0051] [Table 2]

[0052]

[0053] When the sintered body is irradiated with excitation light, it emits light including the excitation light converted by the wavelength of the fluorescent material contained in the sintered body and the excitation light transmitted through the sintered body. In the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) are (x=0.549, y=0.425) as the 1a point, (x=0.557, y=0.433) as the 2a' point, and (x=0.582, y=0.583) as the 3a' point. =0.409) is set as the 3a' point, (x=0.576, y=0.407) is set as the 4a point, and the 1' straight line connecting the 1a point and the 2a' point, the 2' straight line connecting the 2a' point and the 3a' point, the 3' straight line connecting the 3a' point and the 4th straight line connecting the 4a point and the 1a point define the area A2, and the light emitted from the sintered body preferably has a hue within the area A2. If light having a hue within the area A2 is emitted from the sintered body, the light having a hue within the area A1, that is, the light on the shorter wavelength side, becomes more. Figure 4 The area A2 is shown in the chromaticity diagram of the CIE 1931 color system. Table 3 shows the chromaticity coordinates of the point 1a, the point 2a', the point 3a', and the point 4a representing the area A2.

[0054] [Table 3]

[0055]

[0056] When the sintered body is irradiated with the excitation light, it emits light including the excitation light converted by the wavelength of the fluorescent material contained in the sintered body and the excitation light transmitted through the sintered body. In the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) are (x=0.549, y=0.425) as the 1a point, (x=0.557, y=0.433) as the 2a' point, (x=0.579, y=0.412) as the 3a' point, and (x=0.569, y=0.433) as the 4a' point. 0.412) is set as the 4a" point, the 1' straight line connecting the 1a point and the 2a' point, the 2" straight line connecting the 2a' point and the 3a" point, the 3" straight line connecting the 3a" point and the 4a" point, and the 4" straight line connecting the 4a" point and the 1a point define the area A3, and the light emitted from the sintered body preferably has the color tone within the above-mentioned area A3. If light with the color tone within the area A3 is emitted from the sintered body, the light with the color tone within the areas A1 and A2, that is, the light on the shorter wavelength side becomes more. Figure 5 The area A3 is shown in the chromaticity diagram of the CIE 1931 color system. Table 4 shows the chromaticity coordinates of the point 1a, the point 2a', the point 3a", and the point 4a" representing the area A3.

[0057] [Table 4]

[0058]

[0059] Figure 6 The chromaticity diagram of the CIE 1931 color system shows region A, region A1, region A2, and region A3 that meet the amber color requirements specified in the ECE standard. Region A1, region A2, and region A3 are within region A that meets the amber color requirements specified in the ECE standard, and are hues on the shorter wavelength side within region A. Region A2 is an area on the left side of the 2' straight line connecting the 2a' point (x=0.557, y=0.433) and the 3a' point (x=0.582, y=0.409) within the range of region A1 in the chromaticity diagram of the CIE color system. Region A3 is a hue on the shorter wavelength side than regions A1 and A2.

[0060] The sintered body contains at least one phosphor selected from a nitride phosphor having a composition represented by the following formula (I) and an α-sialon phosphor having a composition represented by the following formula (II).

[0061] (Ba 1-u-w M 1 u M 2 w )2Si5N8 (I)

[0062] (In the above formula (I), M 1is at least one element selected from Sr, Ca and Mg, M 2 It is at least one element selected from Eu, Ce, Tb and Mn, and u and w satisfy 0<u≤0.5 and 0.001≤w<0.5 respectively. )

[0063] M 3 q Si 12-(r+s) Al r+s O s N1 6-s :Eu t (II)

[0064] (In the above formula (II), M 3 is at least one element selected from Li, Mg, Ca, Sr, Y and lanthanide elements, wherein the lanthanide elements do not include La and Ce, and q, r, s and t satisfy 0<q≤2.0, 2.0≤r≤6.0, 0≤s≤1.0, 0.001≤t≤0.5 respectively.

[0065] Preferably, the sintered body contains only at least one phosphor selected from the group consisting of a nitride phosphor having a composition represented by the above formula (I) and an α-sialon phosphor having a composition represented by the above formula (II), and does not contain other phosphors having a composition different from the composition represented by the above formula (I) or the composition represented by the above formula (II). The sintered body may also contain only a nitride phosphor having a composition represented by the above formula (I). The sintered body may also contain both a nitride phosphor having a composition represented by the above formula (I) and an α-sialon phosphor sintered body having a composition represented by the above formula (II).

[0066] For the nitride phosphor, in the composition represented by the above formula (I), the element M 1 It is an element that forms a crystal structure of a matrix crystal together with Ba. For a nitride phosphor, in 1 mol of the composition represented by the above formula (I), the element M 1 The molar ratio is expressed as the product of 2 and the variable u. In the above formula (I), the variable u is in the range of more than 0 and less than 0.5 (0<u≤0.5), can be in the range of more than 0.1 and less than 0.48 (0.1≤u≤0.48), can also be in the range of more than 0.2 and less than 0.45 (0.2≤u≤0.45), preferably in the range of more than 0.25 and less than 0.45 (0.25≤u≤0.45). In the composition of the nitride phosphor, the element M that constitutes the crystal structure of the matrix crystal together with Ba 1 The molar ratio of M has an influence on the luminous properties and color tone of the sintered body after irradiation with the excitation light, including the luminous flux. 1When the variable u in the product of 2 of the molar ratio of and the variable u is greater than 0 and within a range of less than 0.5, and preferably within a range of greater than 0.25 and less than 0.45, the sintered body containing the nitride phosphor emits the following light: the irradiated excitation light is wavelength-converted by the nitride phosphor and has a hue within region A1, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body after the excitation light is wavelength-converted by the phosphor contained in the sintered body and the excitation light is transmitted through the sintered body in the luminescence spectrum is greater than 0.005.

[0067] For the nitride phosphor, in the composition represented by the above formula (I), the element M 2 For the nitride phosphor, in 1 mol of the composition represented by the above formula (I), the activation element M 2 The molar ratio is represented by the product of 2 and the variable w. In the above formula (I), the variable w is in the range of 0.001 to less than 0.5 (0.001≤w<0.5), may be in the range of 0.001 to less than 0.1 (0.001≤w<0.1), may be in the range of 0.001 to less than 0.05 (0.001≤w<0.05), may be in the range of 0.001 to less than 0.01 (0.001≤w<0.01), may be in the range of 0.001 to less than 0.005 (0.001≤w<0.005), may be in the range of 0.001 to less than 0.0035 (0.001≤w<0.0035), may be in the range of 0.001 to less than 0.0025 (0.001≤w<0.0025). In the composition of the nitride phosphor, the molar ratio of the activation element affects the luminous properties and color tone of the sintered body after irradiation with the excitation light, including the luminous flux. For the nitride phosphor, in the composition represented by the above formula (I), if the element M as the activation element is 2 The larger the molar ratio of the phosphor, the higher the luminous intensity when irradiated with the excitation light. The sintered body containing the phosphor having high luminous intensity when irradiated with the excitation light can be made thin. The thin sintered body can easily extract the light in the thickness direction of the sintered body. In the present specification, specifically, in the composition represented by the above formula (I) consisting only of the element M as the activation element, 2When the thickness of a sintered body formed of a nitride phosphor having a molar ratio of Eu and a variable w in the range of 0.001 or more and less than 0.5 is 80 μm or less, the sintered body is considered to be thin. When a thin sintered body is irradiated with excitation light, it emits light including light obtained by wavelength conversion of the excitation light by the phosphor contained in the thin sintered body and light after the excitation light passes through the sintered body, and the light emitted from the sintered body has a hue within region A1, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is greater than 0.005. In addition, for the nitride phosphor, in the composition represented by the above formula (I), if the element M as the activation element 2 When the molar ratio of is small, the luminous intensity becomes low when irradiated with excitation light. The sintered body containing the phosphor having low luminous intensity when irradiated with excitation light can be set as a thick sintered body. The thick sintered body can be set as a sintered body with high mechanical strength. In this specification, specifically, the element M as the activation element in the composition represented by the above formula (I) alone 2 When the thickness of a sintered body formed of a nitride phosphor in which the molar ratio of Eu is 2 and the variable w is within the range of 0.001 or more and less than 0.5, exceeds 220 μm, the thickness of the sintered body is considered to be thick. When a thick sintered body is irradiated with excitation light, it emits light including light obtained by wavelength conversion of the excitation light by the phosphor contained in the thick sintered body and the excitation light after passing through the sintered body, and the light emitted by the sintered body has a hue within region A, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is greater than 0.005. However, when the thickness of the sintered body is too thick, for example, more than 300 μm, sometimes less excitation light is released from the sintered body, and the integral value ratio Z2 / Z1 of the light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and the excitation light after passing through the sintered body and the light emitted from the sintered body in the emission spectrum is less than 0.005, and light with a relatively low luminous flux is emitted. Therefore, the thickness of the sintered body is preferably 300 μm or less.

[0068] The nitride phosphor having the composition represented by the above formula (I) may have a structure containing Eu as the element M. 2 The composition is represented by the following formula (I-1).

[0069] (Ba 1-u-w M 1 u Eu w )2Si5N8(I-1)

[0070] (In the above formula (I-1), M 1 is at least one element selected from Sr, Ca and Mg, and u and w satisfy 0<u≤0.5 and 0.001≤w<0.5 respectively. )

[0071] The nitride phosphor having the composition represented by the above formula (I) may have a phosphor containing Sr as the element M. 1 The composition is represented by the following formula (I-2).

[0072] (Ba 1-u-w Sr u M 2 w )2Si5N8(I-2)

[0073] (In the above formula (I-2), M 2 It is at least one element selected from Eu, Ce, Tb and Mn, and u and w satisfy 0<u≤0.5 and 0.001≤w<0.5 respectively. )

[0074] The nitride phosphor having the composition represented by the above formula (I) may have a phosphor containing Sr as the element M. 1 , containing Eu as element M 2 The composition is represented by the following formula (I-3).

[0075] (Ba 1-u-w Sr u Eu w )2Si5N8(I-3)

[0076] (In the above formula (I-3), u and w satisfy 0<u≤0.5 and 0.001≤w<0.5 respectively.)

[0077] The relative density of the sintered body is preferably 97% or more. If the relative density of the sintered body is 97% or more, a sintered body containing only at least one phosphor selected from the nitride phosphor having the composition represented by the above formula (I) and the α-sialon phosphor having the composition represented by the above formula (II) emits light having a hue within the region A1 when irradiated with excitation light. The relative density of the sintered body is preferably 99.7% or less, more preferably 99.5% or less. If the relative density of the sintered body is 99.7% or less, the value obtained by subtracting the relative density from 100% becomes the porosity. If the relative density of the sintered body is 97% or more, the scattering of light caused by the voids in the sintered body can be suppressed, the light can be extracted well, and the following light is emitted: light obtained after the excitation light is converted in wavelength by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, light emitted from the sintered body, the integral value ratio Z2 / Z1 in the emission spectrum is 0.005 or more, and the luminous flux is high.

[0078] It is preferred that the sintered body contains only the nitride phosphor and the relative density is within the range of 97% to 99.7%. If the sintered body contains only the nitride phosphor and the relative density is within the range of 97% to 99.7%, when the sintered body is irradiated with excitation light, it emits light having a hue within the region A1, including light obtained after the excitation light is wavelength-converted by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is 0.005 or more, and the light flux is high.

[0079] The relative density of a sintered body is a value calculated from the apparent density of the sintered body relative to the true density of the sintered body. The relative density of a sintered body is calculated by the following calculation formula (1).

[0080] [Mathematical formula 1]

[0081]

[0082] The true density of the sintered body is the value obtained by multiplying the mass ratio (mass %) of the phosphor relative to 100 mass % of the sintered body by the true density of the phosphor. When the sintered body is formed of a molded body composed of only one type of phosphor, the true density of the phosphor is the true density of the sintered body.

[0083] The apparent density of the sintered body is a value obtained by dividing the mass of the sintered body by the volume of the sintered body obtained by the Archimedes method, and is calculated by the following formula (2). In the following formula (2), the volume of the sintered body refers to the volume obtained by the Archimedes method.

[0084] [Mathematical formula 2]

[0085]

[0086] The thickness of the sintered body is preferably within a range of 30 μm to 300 μm. If the thickness of the sintered body is within a range of 30 μm to 300 μm, the irradiated excitation light is scattered in the sintered body and wavelength-converted by the phosphor at a good efficiency, and the irradiated excitation light is transmitted, and light having a hue within the region A1, including light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is 0.005 or more, and the light flux is high. In addition, if the thickness of the sintered body is within a range of 30 μm to 300 μm, it has sufficient mechanical strength.

[0087] The sintered body includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2When Eu is used and w satisfies 0.001≤w<0.05, the thickness is preferably in the range of 50 μm or more and 180 μm or less. The sintered body comprises the nitride phosphor represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.005≤w≤0.01, the thickness can be in the range of 50 μm to 120 μm. 2 The nitride phosphor with a large molar ratio has a higher emission intensity when irradiated with excitation light. In the case where the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably in the range of 50 μm to 250 μm, and more preferably in the range of 50 μm to 120 μm, the sintered body emits the following light when irradiated with excitation light: light having a hue within the region A1, including light obtained after wavelength conversion of the excitation light by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is greater than 0.005.

[0088] The sintered body includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.001≤w<0.01, the thickness is preferably in the range of 50 μm or more and 250 μm or less. The sintered body comprises the nitride phosphor represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.001≤w<0.01, the thickness may be in the range of 55 μm to 240 μm, or in the range of 60 μm to 230 μm. 2 The nitride phosphor with a large molar ratio has a higher emission intensity when irradiated with excitation light. In the case where the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably in the range of 50 μm to 250 μm, the sintered body emits the following light when irradiated with excitation light: light having a hue within the region A1, including light obtained after wavelength conversion of the excitation light by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and light emitted from the sintered body having an integral value ratio Z2 / Z1 in the emission spectrum of 0.005 or more.

[0089] The sintered body includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.001≤w<0.005, the thickness is preferably in the range of 80 μm or more and 250 μm or less. The sintered body comprises the nitride phosphor represented by the above formula (I), wherein M 2When Eu and w satisfies 0.001≤w<0.005, the thickness is more preferably in the range of 90μm to 240μm, and further preferably in the range of 100μm to 230μm. The nitride phosphor whose variable w, which represents the product of 2 of the molar ratio of Eu and the variable w, is in the range of 0.001 to less than 0.005 has a higher luminous intensity when irradiated with excitation light. In the case where the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably in the range of 80μm to 250μm. Then the sintered body emits the following light when irradiated with excitation light: light having a hue within region A1, light obtained after wavelength conversion of the excitation light by the nitride phosphor contained in the sintered body and the excitation light after passing through the sintered body, and light emitted from the sintered body having an integral value ratio Z2 / Z1 in the luminescence spectrum of 0.005 or more.

[0090] The sintered body comprises a nitride phosphor represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.003≤w≤0.0045, the thickness is preferably in the range of 100 μm to 200 μm. The sintered body comprises the nitride phosphor represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.003≤w≤0.0045, the thickness is more preferably in the range of 100 μm to 185 μm. 2 The nitride phosphor having a molar ratio of Eu and a variable w representing the product of 2 and the variable w in the range of 0.003 or more and less than 0.0045 has a high emission intensity when irradiated with excitation light. In the case where the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably in the range of 100 μm or more and 200 μm or less, and more preferably in the range of 100 μm or more and 185 μm or less, the sintered body emits the following light when irradiated with excitation light: light having a hue within the region A1, including light obtained after wavelength conversion of the excitation light by the nitride phosphor contained in the sintered body and the excitation light after passing through the sintered body, and light emitted from the sintered body having an integral value ratio Z2 / Z1 in the emission spectrum of 0.005 or more.

[0091] The sintered body includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.001≤w<0.0035, the thickness is preferably in the range of 120 μm or more and 250 μm or less. The sintered body includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2When Eu is used and w satisfies 0.001≤w<0.0035, the thickness is more preferably in the range of 130 μm to 240 μm, and further preferably in the range of 135 μm to 230 μm. 2 The nitride phosphor whose molar ratio is Eu and the variable w representing the product of 2 and the variable w is within the range of 0.001 or more and less than 0.0035 has a low emission intensity when irradiated with excitation light. In the case where the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably within the range of 120 μm or more and 250 μm or less, more preferably within the range of 130 μm or more and 240 μm or less, and further preferably within the range of 135 μm or more and 230 μm or less, the sintered body emits the following light when irradiated with excitation light: light having a hue within the region A1, including light obtained after wavelength conversion of the excitation light by the nitride phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is 0.005 or more.

[0092] The sintered body comprises a nitride phosphor represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.002≤w≤0.003, the thickness is preferably within a range of 130 μm to 183 μm. The sintered body comprises a nitride phosphor represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.002≤w≤0.003, the thickness is more preferably in the range of 135 μm to 182 μm. 2 The nitride phosphor whose molar ratio is Eu and the variable w representing the product of 2 and the variable w is in the range of 0.002 or more and 0.003 or less has a low emission intensity when irradiated with excitation light. In the case where the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably in the range of 130 μm or more and 183 μm or less, and more preferably in the range of 135 μm or more and 182 μm or less, the sintered body emits the following light when irradiated with excitation light: light having a hue within the region A1, including light obtained after wavelength conversion of the excitation light by the nitride phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is 0.005 or more.

[0093] The sintered body includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2When Eu is used and w satisfies 0.001≤w<0.0025, the thickness is preferably in the range of 150 μm or more and 250 μm or less. The sintered body includes the nitride phosphor represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.001≤w<0.0025, the thickness is more preferably in the range of 160 μm to 245 μm, and further preferably in the range of 170 μm to 240 μm. 2 The nitride phosphor whose molar ratio is Eu and the variable w representing the product of 2 and the variable w is within the range of 0.001 or more and less than 0.0025 has a low emission intensity when irradiated with excitation light. In the case where the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably within the range of 150 μm or more and 250 μm or less, more preferably within the range of 160 μm or more and 245 μm or less, and further preferably within the range of 170 μm or more and 240 μm or less, the sintered body emits the following light when irradiated with excitation light: light having a hue within the range of region A1, light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and light emitted from the sintered body having an integral value ratio Z2 / Z1 in the emission spectrum of 0.005 or more.

[0094] The sintered body includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.001≤w≤0.002, the thickness is preferably in the range of 180 μm to 250 μm. The sintered body comprises the nitride phosphor represented by the above formula (I), wherein M 2 When Eu is used and w satisfies 0.001≤w≤0.002, the thickness is more preferably in the range of 181 μm to 240 μm, and further preferably in the range of 182 μm to 230 μm. 2The nitride phosphor whose molar ratio is Eu and the variable w representing the product of 2 and the variable w is in the range of 0.001 or more and 0.002 or less has a low emission intensity when irradiated with excitation light. In the case where the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably in the range of 180 μm or more and 250 μm or less, more preferably in the range of 181 μm or more and 240 μm or less, and further preferably in the range of 182 μm or more and 230 μm or less, the sintered body emits the following light when irradiated with excitation light: light having a hue within the range of region A1, light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is 0.005 or more.

[0095] The sintered body is preferably a sintered body made by the following method: sintering phosphor particles having an average particle size Db (Fisher Sub-sieve sizer's number) less than 1 μm measured by Fisher Sub-sieve sizer (hereinafter referred to as "FSSS method"). If the sintered body is a sintered body made by sintering phosphor particles having an average particle size Db less than 1 μm measured by the FSSS method, it is easy to promote the particle growth of the phosphor particles, and the particle size of the phosphor particles that can be confirmed on the fracture surface of the sintered body is larger than that of the phosphor particles used as the raw material. As a result, there are fewer interfaces in the sintered body formed by the phosphor particles, thereby becoming a sintered body that allows light to easily pass through the sintered body. The average particle size Db of the phosphor particles used as the raw material for forming the sintered body is preferably within the range of 0.01 μm to 0.99 μm, more preferably within the range of 0.05 μm to 0.98 μm, further preferably within the range of 0.10 μm to 0.95 μm, and may be within the range of 0.50 μm to 0.95 μm. The FSSS method is a type of air permeation method, which is a method for determining the particle size of primary particles by measuring the specific surface area using the air flow resistance.

[0096] The sintered body is preferably a sintered body made by the following method: the average particle size Db measured by the Fisher sub-sieve particle size analyzer method is relative to the volume median particle size Dm measured by the laser diffraction particle size distribution method. The particle size ratio Db / Dm is 0.45 or less. The laser diffraction particle size distribution method is a measurement method that uses the scattered light of the laser light irradiated on the particles to make the particle size distribution without distinguishing between primary particles and secondary particles. The volume median particle size Dm is the volume median particle size with a cumulative frequency of 50% from the small diameter side in the particle size distribution measured by the laser diffraction particle size distribution method. The closer the particle size ratio Db / Dm is to 1, the less the amount of secondary particles is contained, and the more the proportion of primary particles contained in the powder. If the particle size ratio Db / Dm of the phosphor is less than 0.45, the proportion of secondary particles contained in the powder increases. If the sintered body is a sintered body made by sintering phosphor particles having a particle size ratio Db / Dm of 0.45 or less, the proportion of secondary particles contained in the powder containing the phosphor particles as a raw material is large, and small particles can be arranged between large particles, and the molding density is easily improved. As a result, the particle growth of the phosphor particles is easily promoted to form a sintered body with a high relative density. The particle size ratio Db / Dm of the phosphor particles used as the raw material for forming the sintered body can be 0.44 or less, 0.43 or less, or 0.42 or less, preferably 0.30 or more, 0.32 or more, or 0.35 or more.

[0097] The sintered body is preferably formed by the following method: sintering phosphor particles having a volume median particle size Dm in the range of 0.02 μm to 3.5 μm as measured by a laser diffraction particle size distribution measurement method, wherein Dm may be in the range of 0.05 μm to 3.2 μm or in the range of 0.05 μm to 3.0 μm. If the sintered body is a sintered body made by sintering phosphor particles having a volume median particle size in the range of 0.02 μm to 3.5 μm as measured by a laser diffraction particle size distribution measurement method, the particle growth of the phosphor particles is easily promoted, and the particle size of the phosphor particles that can be confirmed on the fracture surface of the sintered body is larger than that of the phosphor particles as the raw material. By making the interface in the sintered body formed by the phosphor particles, a sintered body is formed in which light is easily transmitted in the sintered body. If the volume median particle size Dm of the phosphor particles used as the raw material for forming the sintered body is in the range of greater than 0.02 μm and less than 3.5 μm, the particle size ratio Db / Dm becomes less than 0.45, the particle size of the phosphor particles that can be confirmed on the fracture surface of the sintered body becomes larger, the interface of the phosphor particles can be reduced, and a sintered body with a relatively high density can be obtained.

[0098] For a sintered body, in the scanning electron microscope (SEM) image of the fracture surface of the sintered body, each phosphor particle constituting the sintered body can be confirmed, and the major diameter of the phosphor particles is preferably in the range of 0.1 μm or more and 20 μm or less. It can be inferred that if the major diameter of the phosphor particles that can be confirmed in the SEM image of the fracture surface of the sintered body is in the range of 0.1 μm or more and 20 μm or less, it is larger than the phosphor particles as the raw material, and the particle growth of the phosphor particles as the raw material can be promoted. The major diameter of the phosphor particles refers to the longest diameter from one end of the contour of the phosphor particles that can confirm the contour through the inside of the phosphor particles to the other end of the phosphor particles in the SEM image of the fracture surface of the sintered body. The major diameter of the phosphor particles that can be confirmed in the SEM image of the fracture surface of the sintered body can be in the range of 0.15 μm or more and 15 μm or less.

[0099] The method for producing a sintered body preferably includes: preparing a phosphor; preparing a molded body including the phosphor; and firing the molded body to obtain a sintered body.

[0100] As the phosphor, at least one phosphor selected from the group consisting of the nitride phosphor represented by the above formula (I) and the α-sialon phosphor having the composition represented by the above formula (II) is prepared. The phosphor may be prepared by acquiring from another company or by manufacturing using the following method.

[0101] In the case where the phosphor includes the nitride phosphor represented by the above formula (I), the nitride phosphor preferably includes: a first compound containing Ba, a first compound containing at least one element M selected from Sr, Ca and Mg 1 The second compound contains at least one element M selected from Eu, Ce, Tb and Mn 2 The third compound, and the compound containing Si, so that Ba, element M 1 Element M 2 , and Si satisfy the composition represented by the above formula (I) and mix the compounds to obtain a raw material mixture, which is obtained by heat treating the raw material mixture at a temperature in a range of 980°C to 1680°C in an atmosphere containing nitrogen. The nitride phosphor can be manufactured with reference to Japanese Patent Gazette No. 2020-083739. The nitride phosphor is preferably a phosphor particle having an average particle size Db measured by the FSSS method of less than 1 μm. The nitride phosphor is preferably a phosphor particle having a particle size ratio Db / Dm of 0.45 or less relative to the volume median particle size Dm measured by the laser diffraction particle size distribution measurement method.

[0102] In the process of preparing a molded body, the raw material for forming the molded body includes the nitride phosphor represented by the above formula (I) and the α-sialon phosphor having the composition represented by the above formula (II). In the process of preparing a molded body, the raw material for forming the molded body is preferably formed by the phosphors forming the nitride phosphor represented by the above formula (I) and the α-sialon phosphor represented by the above formula (II). In the process of preparing a molded body, the raw material for forming the molded body is preferably formed by the nitride phosphor having the composition represented by the above formula (I). The content of the nitride phosphor having the composition represented by the above formula (I) in the raw material for forming the molded body is preferably 100% by mass, and may be 95% by mass or more, 97% by mass or more, 98% by mass or more, 99% by mass or more, or 99.5% by mass or more. In the raw material for forming the molded body, the remainder of the content of the nitride phosphor having the composition represented by the above formula (I) may be the α-sialon phosphor having the composition represented by the above formula (II). Preferably, the raw material or raw material mixture for forming the molded body does not contain impurities that inhibit the particle growth of the phosphor particles used as the raw materials, except for the nitride phosphor represented by the above formula (I) and the α-sialon phosphor represented by the above formula (II). Here, the impurities that inhibit the particle growth of the phosphor particles refer to hydrides, nitrides, carbonates, chlorides, imide compounds, and amide compounds of the elements contained in the nitride phosphor or the α-sialon phosphor.

[0103] In the process of preparing the molded body, the raw material containing at least one phosphor selected from the group consisting of nitride phosphors and α-sialon phosphors can be formed into a desired shape to obtain a molded body. The raw material containing at least one phosphor selected from the group consisting of nitride phosphors and α-sialon phosphors is preferably a powder, or a slurry containing the powder. The molding method of the molded body can be: a pressing molding method in which the powder is pressed to form a mold, or a slurry molding method in which a slurry containing the powder is prepared and a molded body is obtained from the slurry. As the pressing molding method, for example, there can be cited a mold pressing molding method and a cold isostatic pressing method (CIP: Cold Isostatic Pressing) specified in No. 2109 of JIS Z2500:2000. In order to adjust the shape of the molded body, the molding method can adopt two methods, and CIP molding can be performed after mold pressing molding. In CIP molding, it is preferred to press the molded body using water as a medium.

[0104] The pressure during mold press molding is preferably in the range of 1 MPa to 50 MPa, more preferably in the range of 2 MPa to 20 MPa, and further preferably in the range of 2 MPa to 15 MPa. If the pressure during mold press molding is within the above range, the molded body can be adjusted to a desired shape.

[0105] The pressure in CIP molding is preferably in the range of 50 MPa to 500 MPa, more preferably in the range of 100 MPa to 450 MPa, and further preferably in the range of 200 MPa to 400 MPa. If the pressure in CIP molding is in the above range, the density of the molded body (molding density) can be increased, and a molded body having a substantially uniform density as a whole can be obtained, and the density of the obtained sintered body can be increased in the subsequent firing step.

[0106] In the process of firing the molded body to obtain a sintered body, the firing temperature is preferably in the range of 1600°C to 2200°C, more preferably in the range of 1600°C to 2000°C, further preferably in the range of 1600°C to 1900°C, and further preferably in the range of 1600°C to 1800°C. If the firing temperature is in the range of 1600°C to 2200°C, a sintered body having a relative density of 97% or more can be obtained. In this specification, firing a molded body that has not been fired is sometimes referred to as firing.

[0107] Examples of the sintering method include atmosphere sintering in a non-oxidizing atmosphere without applying pressure or load, atmosphere pressure sintering in a non-oxidizing atmosphere under pressure, hot press sintering, and spark plasma sintering (SPS).

[0108] Firing is preferably carried out in an atmosphere containing nitrogen. The atmosphere containing nitrogen is preferably an atmosphere containing at least 99% by volume of nitrogen. The nitrogen in the atmosphere containing nitrogen is preferably 99% by volume or more, more preferably 99.5% by volume or more. In the atmosphere containing nitrogen, in addition to nitrogen, trace gases such as oxygen may be contained, and the content of oxygen in the atmosphere containing nitrogen is preferably 1% by volume or less, more preferably 0.5% by volume or less, further preferably 0.1% by volume or less, further preferably 0.01% by volume or less, and particularly preferably 0.001% by volume or less. The atmosphere in the calcining process contains nitrogen, and may be a reducing atmosphere or an atmosphere containing nitrogen and hydrogen. In the case where hydrogen is contained in the atmosphere containing nitrogen in the calcining process, the content of hydrogen in the atmosphere is preferably 1% by volume or more, more preferably 5% by volume or more, and further preferably 10% by volume or more. The atmosphere for heat treatment may be a reducing atmosphere using solid carbon in an atmospheric atmosphere.

[0109] In the process of obtaining the sintered body, the molded body is fired in an atmosphere containing nitrogen, thereby obtaining a sintered body having a particle size having a composition of a nitride phosphor having high luminous intensity and having a relative density of 97% or more.2 In the case of Eu, since divalent Eu is an activator that contributes to the emission of light in the nitride phosphor or α-sialon phosphor, 2+ As the proportion of Eu increases, a sintered body with high luminescence intensity can be obtained. 2+ Easily oxidized to trivalent Eu 3+ However, by firing the molded body in an atmosphere with a high reducing power including nitrogen, the trivalent Eu in the nitride phosphor contained in the molded body is reduced. 3+ Reduced to divalent Eu 2+ Therefore, in nitride phosphors or α-sialon phosphors, divalent Eu 2+ The proportion occupied increases, and a sintered body containing crystals having a composition of a nitride phosphor or an α-sialon phosphor having high luminescence intensity is obtained.

[0110] The sintering atmosphere pressure is preferably in the range of 0.1 MPa to 2.0 MPa, more preferably in the range of 0.2 MPa to 1.5 MPa, and further preferably in the range of 0.5 MPa to 1.2 MPa. The sintering atmosphere pressure is preferably a gauge pressure. If the sintering atmosphere pressure is within the above range, the decomposition of the crystal structure can be suppressed, and a sintered body containing at least one phosphor selected from a nitride phosphor and an α-sialon phosphor having high luminous intensity can be obtained.

[0111] The calcination time may be appropriately selected according to the atmospheric pressure. The calcination time is, for example, 0.5 hours to 20 hours, preferably 1 hour to 10 hours.

[0112] The method for manufacturing a sintered body may include processing the sintered body after the sintered body is obtained. In the method for manufacturing a sintered body, processing the sintered body may include cutting the obtained sintered body into a desired size. It should be noted that as a method for cutting, a known method may be used, for example, a method using a wire saw or the like. The sintered body may be processed in the following manner: the obtained sintered body emits light of a hue within region A1 when irradiated with excitation light, emits light including light emitted from the sintered body and excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 in the emission spectrum is greater than 0.005, and the thickness is within a range of greater than 30 μm and less than 300 μm.

[0113] The sintered body can be combined with a light-emitting element such as an LED or LD to form a light-emitting device. For the light-emitting device, the sintered body is arranged at a position where light is irradiated from an excitation light source such as a light-emitting element, and the sintered body changes the wavelength of the light irradiated from the excitation light source to emit light having a hue within the region A1.

[0114] The light emitting device comprises: an excitation light source emitting light having a peak emission wavelength in a range of 380 nm to 570 nm, and a sintered body arranged at a position where the light is irradiated from the excitation light source. The light emitting device may use a sintered body in combination with a phosphor selected from a nitride phosphor and an α-sialon phosphor and another sintered body containing another phosphor having a different composition.

[0115] The excitation light source that emits light having a peak emission wavelength in the range of 380 nm to 570 nm is preferably a light emitting element. The light emitting element more preferably has a peak emission wavelength in the range of 400 nm to 550 nm. The light emitting element is preferably a nitride semiconductor (In X Al Y Ga 1-X-Y By using a semiconductor light-emitting element as an excitation light source for a light-emitting device, a stable light-emitting device with high efficiency, high linearity of output power relative to input power, and strong resistance to mechanical impact can be obtained.

[0116] Figure 7 and Figure 8 A configuration example of a light emitting device using a sintered body as a wavelength conversion member is shown. Figure 7 is a schematic top view of the light emitting device 100 . Figure 8 yes Figure 7 Schematic cross-sectional view of the light emitting device 100 along the line VII-VII' shown in FIG. The light emitting device 100 includes a light emitting element 10 having a peak emission wavelength in the range of 380 nm to 570 nm, and a wavelength conversion member 51 that emits light when excited by light from the light emitting element 10. The light emitting element 10 is mounted on the substrate 1 by a flip-chip method via a conductive member 61, such as a bump. The wavelength conversion member 51 is arranged on the light emitting surface of the light emitting element 10 via an adhesive layer 80. The side surfaces of the light emitting element 10 and the wavelength conversion member 51 are covered by a light-reflecting covering member 90. The light emitting element 10 can receive power supply from the outside of the light emitting device 100 via wiring formed on the substrate 1 and the conductive member 61, so that the light emitting device 100 emits light. The light emitting device 100 may include a semiconductor element 11 such as a protective element for preventing the light emitting element 10 from being damaged by an excessive voltage applied. The semiconductor element 11 may be mounted on the substrate 1 via the conductive member 61. The covering member 90 is arranged, for example, to cover the semiconductor element 11. Hereinafter, each member used in the light emitting device will be described. It should be noted that for details, reference can also be made to the disclosure of, for example, Japanese Patent Application Laid-Open No. 2014-112635.

[0117] The bonding layer is preferably formed of a material that can optically connect the light-emitting element to the wavelength conversion member. As the material constituting the bonding layer, for example, it is preferably at least one resin selected from epoxy resin, silicone resin, phenolic resin, and polyimide resin, or an inorganic material such as silicon oxide and silicon nitride. In addition, the light-emitting element and the wavelength conversion member can be directly bonded without passing through the bonding layer.

[0118] Semiconductor elements provided as needed in the light-emitting device include, for example: transistors for controlling light-emitting elements, and protective elements for suppressing damage to light-emitting elements and performance degradation caused by applying excessive voltage. As a protective element, a Zener diode can be cited. In the case where the light-emitting device has a coating component, an insulating material is preferably used as the material of the coating component. More specifically, for example, phenolic resin, epoxy resin, bismaleimide triazine resin (BT resin), polyphthalamide (PPA) resin, and silicone resin can be cited. Colorants, phosphors, and fillers can be added to the coating component as needed. The light-emitting device can use bumps as conductive components. As materials for bumps, Au or its alloys, eutectic solder (Au-Sn), Pb-Sn, lead-free solder, etc. as other conductive components can be used.

[0119] An example of a method for manufacturing a light-emitting device is described. It should be noted that the details may also be referred to, for example, Japanese Patent Publication No. 2014-112635 or Japanese Patent Publication No. 2017-117912. The method for manufacturing a light-emitting device may include a step of arranging a light-emitting element, a step of arranging a semiconductor element as required, a step of preparing a wavelength conversion member, a step of bonding the light-emitting element and the wavelength conversion member, and a step of arranging a covering member.

[0120] For example, in the step of configuring the light-emitting element, the light-emitting element is configured on the substrate. The light-emitting element and the semiconductor element are mounted on the substrate by, for example, a flip-chip method. In addition, in the step of preparing the wavelength conversion component, a wavelength conversion component formed of a sintered body obtained by the above-mentioned manufacturing method is prepared. Next, in the step of bonding the light-emitting element and the wavelength conversion component, the prepared wavelength conversion component is made opposite to the light-emitting surface of the light-emitting element, and the wavelength conversion component is bonded to the light-emitting element via an adhesive layer. Next, in the step of configuring the covering component, the side surfaces of the light-emitting element and the wavelength conversion component are covered with the covering component. The covering component is used to reflect light emitted from the light-emitting element, and in the case where the light-emitting device also has a semiconductor element, it is preferably configured in a manner that the semiconductor element is buried in the covering component. The device can be manufactured as described above. Figure 7 and Figure 8 The light emitting device shown.

[0121] Example

[0122] Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[0123] Preparation of Nitride Phosphors 1 to 6

[0124] Compounds of Ba3N2, Sr3N2, EuN, and Si3N4 were used as raw materials. The compounds as raw materials were weighed in a glove box in an inert gas atmosphere so that the molar ratio of each element as the additive composition became the composition shown in Table 1, and the compounds were mixed to obtain a raw material mixture. The obtained raw material mixture was filled in a crucible, and heat-treated at a gas pressure of 0.9 MPa in gauge pressure, 1600°C, and 5 hours in an atmosphere containing more than 99.9% by volume of nitrogen and the remainder being oxygen (less than 0.1% by volume) to obtain a sintered product. The obtained sintered product was dispersed because the particles were sintered together, and then sieved and graded to remove coarse particles and fine particles, to obtain nitride phosphor particles 1 to 6 having the additive composition shown in Table 1. The composition of the obtained nitride phosphor particles has the composition represented by formula (I), which is substantially the same as the additive composition.

[0125] The obtained nitride phosphor was evaluated as follows. The results are shown in Table 5.

[0126] Average particle size Db

[0127] The average particle diameter Db of nitride phosphors 1 to 6 was measured by the FSSS method using Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific).

[0128] Volume median particle size Dm

[0129] For nitride phosphors 1 to 6, the volume median particle size Dm at which the volume cumulative frequency from the smaller diameter side reached 50% was measured using a laser diffraction particle size distribution measuring apparatus (MASTER SIZER 2000, manufactured by Malvern).

[0130] Chromaticity coordinates (x, y), relative brightness (%), peak wavelength, full width at half maximum

[0131] For nitride phosphors 1 to 6, a spectrofluorophotometer (QE-2000, manufactured by Otsuka Electronics Co., Ltd.) was used to irradiate each nitride phosphor with a light emission peak wavelength of 450 nm and an output of 1300 mW / mm 2 Above and 6000mW / mm 2 Within the following range, specifically 1300mW / mm 2 Above and 1500mW / mm2 The luminescence spectrum of the light emitted from each nitride phosphor at room temperature was measured with excitation light within the following range. The chromaticity coordinates (x, y) in the chromaticity diagram of the CIE1931 color system were calculated based on the data of the luminescence spectrum measured for each nitride phosphor. Based on the data of the luminescence spectrum of the light emitted from each nitride phosphor measured for each nitride phosphor, the brightness of nitride phosphor 5 with the smallest molar ratio of the activation element Eu was set to 100%, and the brightness of Examples 1 to 4 and 6 was calculated as the relative brightness. Based on the data of the luminescence spectrum of the light emitted from each nitride phosphor measured for each nitride phosphor, the luminescence peak wavelength λp (nm) and the half-value full width were calculated. In this specification, the half-value full width refers to the wavelength width at which the luminescence intensity becomes 50% relative to the luminescence peak wavelength showing the maximum luminescence intensity in the luminescence spectrum.

[0132] True density

[0133] For nitride phosphors 1 to 6, the true density (g / cm 3 ).

[0134] [Table 5]

[0135]

[0136] Nitride phosphors 1 to 6 all have the composition represented by the above formula (I). The average particle size Db of nitride phosphors 1 to 6 measured by the FSSS method is less than 1 μm, specifically in the range of 0.70 μm to 0.95 μm. In addition, the particle size ratio Db / Dm of nitride phosphors 1 to 6 is less than 0.45, specifically in the range of 0.30 to 0.41.

[0137] Fig. 9 This is a SEM photograph obtained by observing the nitride phosphor 5 with a scanning electron microscope (SEM). The nitride phosphor 5 contains a large number of phosphor particles having a particle size of less than 1 μm.

[0138] The following measurements were performed on each sintered body of Examples and Comparative Examples described below. The results are shown in Tables 6 to 11.

[0139] Relative density (%)

[0140] The relative density of each sintered body of the example and the comparative example was calculated by the above calculation formulas (1) and (2). The true density of the sintered body was calculated using the true density of the nitride phosphor as the raw material of each sintered body of the example and the comparative example.

[0141] Chromaticity coordinates (x, y)

[0142] Each sintered body of the embodiment and the comparative example was mounted on a light emitting element (LED) to emit light, and used as each light emitting device for testing. A current of 1A was passed through the light emitting element, and the sintered body was irradiated with light having a peak wavelength of 450nm and an output of 1300mW / mm 2 Above m6000W / mm 2 Within the following range, specifically 1300mW / mm 2 Above and 1500mW / mm 2 The excitation light in the following range was measured using a multi-channel spectrometer (PMA-12, Hamamatsu Photonics Co., Ltd.) in the form of a luminescence spectrum of light emitted from the sintered body, including light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and light emitted from the sintered body after the excitation light passed through the sintered body, and the chromaticity coordinates (x, y) in the chromaticity diagram of the CIE1931 color system were calculated based on the measured luminescence spectrum. In the measured luminescence spectrum of the light emitted from each sintered body, the integral value of the wavelength width range surrounded by the horizontal axis with the luminescence intensity (au (arbitrary value)) of 0 (zero) and the luminescence spectrum in the wavelength range of more than 500nm and less than 800nm, i.e., the first integral value Z1, was measured. In the measured luminescence spectrum of the light emitted from each sintered body, the integral value of the wavelength width range surrounded by the horizontal axis with the luminescence intensity (au (arbitrary value)) of 0 (zero) and the luminescence spectrum of the light emitted from the sintered body in the wavelength range of more than 400nm and less than 500nm, that is, the second integral value Z2 is measured. The integral value ratio Z2 / Z1 of the second integral value Z2 relative to the first integral value Z1 is calculated. The chromaticity coordinates of each light-emitting device used in the test are recorded in the chromaticity diagram of the CIE1931 color system, and it is confirmed whether it is within the range of area A1, area A2, and area A3 or outside the range. When the light emitted by each light-emitting device used in the test has a hue within the range of an arbitrary area, it is recorded as "IN", and when the light emitted by each light-emitting device used in the test has a hue outside the range of an arbitrary area, it is recorded as "OUT".

[0143] Relative luminous flux (%)

[0144] In each light emitting device used in each test of the embodiment and the comparative example, a current of 1A was passed through the light emitting element, and the sintered body was irradiated with light having a peak wavelength of 450nm and an output of 1300mW / mm 2 Above and 6000mW / mm 2 Within the following range, specifically 1300mW / mm 2 Above and 1500mW / mm 2The luminous flux (lm) of each light-emitting device was measured using a total luminous flux measuring device for the excitation light within the following range. In the embodiment using the same nitride phosphor, the minimum luminous flux was set to 100%, and the luminous flux of each light-emitting device was calculated in the form of relative luminous flux (%).

[0145] Example 1-1 to Example 1-3

[0146] The nitride phosphor 1 was filled into a mold, and a cylindrical molded body with a diameter of 28.5 mm and a thickness of 10 mm was pressed at a pressure of 2 MPa. CIP molding was further performed at a pressure of 352.8 MPa to form a cylindrical molded body with a diameter of 25 mm and a thickness of 9 mm. The molded body was formed only of the above-mentioned nitride phosphor, and the nitride phosphor was 100% by mass.

[0147] Obtained sintered body

[0148] The obtained compact was placed in a sintering furnace (manufactured by Fuji Electric Industry Co., Ltd.), and sintered at 1675°C and 0.9 MPa for 1 hour in an atmosphere containing 99.9% by volume or more of nitrogen and the remainder being oxygen (0.1% by volume or less) to obtain a sintered body.

[0149] Lighting device for testing

[0150] Each sintered body of Example 1-1 to Example 1-3 was obtained so that each sintered body had a thickness shown in Table 6. Each sintered body was placed on a surface with a peak wavelength of 450 nm and an output of 1300 mW / mm 2 Above and 6000mW / mm 2 Within the following range, specifically 1300mW / mm 2 Above and 1500mW / mm 2 The light emitting device for the test was a light emitting element (LED) irradiating light with excitation light within the following range. The above-mentioned measurement was performed on each light emitting device of Example 1-1 to Example 1-3. The results are shown in Table 6.

[0151] [Table 6]

[0152]

[0153] Each light-emitting device using each sintered body of Example 1-1 to Example 1-3 emits light having a hue within region A1 when irradiated with excitation light, including light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is greater than 0.005, and the excitation light having a shorter wavelength than the light obtained by wavelength conversion of the phosphor contained in the sintered body is separated from the sintered body. Each light-emitting device of Example 1-1 to Example 1-3 emits light having an amber hue on the short wavelength side within region A1 and a high relative luminous flux.

[0154] Fig.10 The chromaticity coordinates (x, y) of the light emitted by each light-emitting device using each sintered body of Examples 1-1 to 1-3 are shown in the chromaticity diagram of the CIE1931 color system, and in the regions A1, A2, and A3. Fig.10 As shown, each light emitting device using each sintered body of Example 1-1 to Example 1-3 emits light having an amber hue in region A2 on the shorter wavelength side within the range of region A1.

[0155] Each sintered body used in each light-emitting device of Example 1-1 to Example 1-3 includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2 The sintered body is a thin sintered body with a thickness in the range of 50 μm to 120 μm, and the luminous intensity becomes high when irradiated with excitation light, and w satisfies 0.001≤w<0.05, more specifically, satisfies 0.005≤w≤0.01, and the molar ratio of Eu as an activation element is large. Each light-emitting device of Example 1-1 to Example 1-3 emits light having a color tone within the region A1, including light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and light emitted from the sintered body after the excitation light passes through the sintered body, and the integral value ratio Z2 / Z1 in the luminescence spectrum is 0.005 or more, even when a thin sintered body is used.

[0156] Example 2-1 to Example 2-5, and Comparative Example 2-6

[0157] Sintered bodies were obtained in the same manner as in Examples 1-1 to 1-3 except that nitride phosphor 2 was used, and sintered bodies of Examples 2-1 to 2-5 and Comparative Example 2-6 were obtained so as to have thicknesses shown in Table 7. Each sintered body was placed in a state where the irradiation light had a peak wavelength of 450 nm and an output of 1300 mW / mm 2 Above and 6000mW / mm 2 Within the following range, specifically 1300mW / mm 2 Above and 1500mW / mm2 The light emitting device for the test was a light emitting element (LED) irradiating light with excitation light within the following range. The above-mentioned measurement was performed on each light emitting device of Example 2-1 to Example 2-5 and the light emitting device of Comparative Example 2-6. The results are shown in Table 7.

[0158] [Table 7]

[0159]

[0160] Each light-emitting device using each sintered body of Example 2-1 to Example 2-5 emits light having a hue within region A1 when irradiated with excitation light, including light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is greater than 0.005, wherein the excitation light having a shorter wavelength than the light obtained by wavelength conversion of the sintered body is separated from the sintered body. Each light-emitting device of Example 2-1 to Example 2-5 emits light having an amber hue on the short wavelength side within region A1 and a high relative luminous flux.

[0161] The light-emitting device using the sintered body of Comparative Example 2-6 emits the following light when irradiated with excitation light: light having a hue within the range of area A1, but including light obtained after the excitation light is converted by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is less than 0.005, the proportion of excitation light with a shorter wavelength than the light obtained after the wavelength conversion by the phosphor contained in the sintered body that escapes from the sintered body is small, and the relatively low luminous flux is light.

[0162] Fig.11 This is a diagram showing the chromaticity coordinates (x, y) of the light emitted by the light emitting devices using the sintered bodies of Examples 2-1 to 2-5 and the sintered body of Comparative Example 2-6 in the chromaticity diagram of the CIE1931 color system, in areas A1, A2, and A3. Fig.11 As shown, each light emitting device using each sintered body of Example 2-1 to Example 2-5 emits light having an amber hue within the range of A3 on the shorter wavelength side even within the region A1.

[0163] like Fig.11 As shown, the light emitting device using the sintered body of Comparative Example 2-6 emits light having a color tone within the region A1 but outside the range of the regions A2 and A3.

[0164] Each sintered body used in each light-emitting device of Example 2-1 to Example 2-5 includes a nitride phosphor having a composition represented by the above formula (I), wherein M2 Eu, w satisfies 0.001≤w<0.0035, more specifically, satisfies 0.002≤w≤0.003, and the thickness of the sintered body is within the range of 130 μm to 183 μm. The light-emitting devices of Examples 2-1 to 2-5 using these sintered bodies emit the following light: excitation light having a wavelength shorter than that of light obtained by wavelength conversion of the phosphor contained in the sintered body is separated from the sintered body, light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and excitation light after passing through the sintered body, and light emitted from the sintered body has an integral value ratio Z2 / Z1 of 0.005 or more in the emission spectrum, and has a high relative luminous flux.

[0165] The sintered body used in the light-emitting device of Comparative Example 2-6 includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2 Eu, w satisfies 0.001≤w<0.0035, and more specifically satisfies 0.002≤w≤0.003, but in order to obtain light of a desired color tone, the thickness of the sintered body exceeds 183 μm. The light-emitting device of Comparative Example 2-6 has a sintered body with a thickness exceeding 183 μm, and therefore emits the following light: less excitation light detached from the sintered body, light obtained after wavelength conversion of the excitation light by the phosphor contained in the sintered body and excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is less than 0.005, and the relative luminous flux is low.

[0166] Example 3-1 to Example 3-3

[0167] The sintered bodies were obtained in the same manner as in Examples 1-1 to 1-3 except that the nitride phosphor 3 was used, and the sintered bodies of Examples 3-1 to 3-3 were obtained so as to have the thickness shown in Table 8. The sintered bodies were arranged in a state where the irradiation light had a peak wavelength of 450 nm and an output of 1300 mW / mm 2 Above and 6000mW / mm 2 Within the following range, specifically 1300mW / mm 2 Above and 1500mW / mm 2 The light emitting device for the test was a light emitting element (LED) that irradiated light with excitation light within the following range. The above-mentioned measurement was performed on each light emitting device of Example 3-1 to Example 3-3. The results are shown in Table 8.

[0168] [Table 8]

[0169]

[0170] Each light-emitting device using each sintered body of Examples 3-1 to 3-3 emits light having a hue within the range of region A1, including light obtained by wavelength conversion of excitation light by the phosphor contained in the sintered body and excitation light transmitted through the sintered body, and light emitted from the sintered body having an integral value ratio Z2 / Z1 of 0.005 or more in the emission spectrum, wherein excitation light having a shorter wavelength than the light obtained by wavelength conversion of the phosphor contained in the sintered body is separated from the sintered body. Each light-emitting device of Examples 3-1 to 3-3 emits light having an amber hue on the short wavelength side within region A1 and having a high relative luminous flux.

[0171] Fig.12 This is a diagram showing the chromaticity coordinates (x, y) of the light emitted by the light emitting devices using the sintered bodies of Examples 3-1 to 3-3, and regions A1, A2, and A3 in the chromaticity diagram of the CIE1931 color system. Fig.12 As shown, each light-emitting device using each sintered body of Example 3-1 to Example 3-3 emits light having the following hue: in the chromaticity diagram of the CIE color system, within the range of area A1, it becomes an amber hue in area A2 which is closer to the left side than the 2' straight line connecting the 2a' point (x=0.557, y=0.433) and the 3a' point (x=0.582, y=0.409).

[0172] Each sintered body used in each light-emitting device of Example 3-1 to Example 3-3 includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2 Eu, w satisfies 0.001≤w<0.005, more specifically, satisfies 0.003≤w≤0.0045, and the thickness of the sintered body is within the range of 80μm to 200μm, more specifically, the thickness of the sintered body is within the range of 100μm to 200μm. Each light emitting device of Examples 3-1 to 3-3 using these sintered bodies emits the following light: excitation light having a wavelength shorter than the light obtained by wavelength conversion of the phosphor contained in the sintered body is separated from the sintered body, light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is 0.005 or more, and the relative luminous flux is high.

[0173] Example 4-1 to Example 4-3, and Comparative Example 4-4 to Comparative Example 4-5

[0174] Sintered bodies were obtained in the same manner as in Examples 1-1 to 1-3 except that nitride phosphor 4 was used, and sintered bodies of Examples 4-1 to 4-3 and Comparative Examples 4-4 to 4-5 were obtained in such a manner as to have the thicknesses shown in Table 9. Each sintered body was placed in a state where the irradiation light had a peak wavelength of 450 nm and an output of 1300 mW / mm 2 Above and 6000mW / mm 2 Within the following range, specifically 1300mW / mm 2 Above and 1500mW / mm 2 The following range of excitation light was used as the irradiation light side of the light emitting element (LED) as each light emitting device for the test. The above-mentioned measurement was performed on each light emitting device of Example 4-1 to Example 4-3 and each light emitting device of Comparative Example 4-4 to Comparative Example 4-5. The results are shown in Table 9.

[0175] [Table 9]

[0176]

[0177] Each light-emitting device using each sintered body of Examples 4-1 to 4-3 emits light having a hue within region A1, including light obtained by wavelength conversion of excitation light by the phosphor contained in the sintered body and excitation light transmitted through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is 0.005 or more, wherein the excitation light having a shorter wavelength than the light obtained by wavelength conversion of the sintered body is separated from the sintered body. Each light-emitting device of Examples 4-1 to 4-3 emits light having an amber hue on the short wavelength side within region A1 and having a high relative luminous flux.

[0178] Each light-emitting device using each sintered body of Comparative Example 4-4 and Comparative Example 4-5 emits the following light: light having a hue within area A1, including light obtained after the excitation light is converted by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is less than 0.005, the proportion of excitation light with a shorter wavelength than the light obtained after the wavelength conversion of the sintered body escaping from the sintered body is small, and the relatively low luminous flux.

[0179] Fig.13 This is a diagram showing regions A1, A2, and A3 in the chromaticity diagram of the CIE1931 color system, and the chromaticity coordinates (x, y) of the light emitting devices of Examples 4-1 to 4-3 and Comparative Examples 4-4 to 4-5. Fig.13As shown, each light emitting device using each sintered body of Example 4-1 to Example 4-3 emits light having an amber hue within the range of A3 on the shorter wavelength side even within the area A1.

[0180] like Fig.13 As shown, each light emitting device using each sintered body of Comparative Example 4-4 and Comparative Example 4-5 emits light having a color tone within the region A1 but outside the range of the region A2 and the region A3.

[0181] Each sintered body used in each light-emitting device of Examples 4-1 to 4-3 includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2 Eu, w satisfies 0.001≤w<0.0035, more specifically, satisfies 0.002≤w≤0.003, and the thickness of the sintered body is within the range of 130 μm to 183 μm. Each light emitting device of Examples 4-1 to 4-3 using these sintered bodies emits the following light: excitation light having a wavelength shorter than that of light obtained by wavelength conversion of the phosphor contained in the sintered body is separated from the sintered body, light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and excitation light after passing through the sintered body, and light emitted from the sintered body has an integral value ratio Z2 / Z1 of 0.005 or more in the emission spectrum, and has a high relative luminous flux.

[0182] Each sintered body used in each light-emitting device of Comparative Examples 4-4 and 4-5 contains a nitride phosphor having a composition represented by the above formula (I), wherein M 2 Eu, w satisfies 0.002≤w<0.0035, more specifically, satisfies 0.002≤w≤0.003, but the thickness of the sintered body exceeds 183 μm and becomes thicker. Since the light-emitting devices of Comparative Examples 4-4 and 4-5 have a sintered body with a thickness exceeding 183 μm, less excitation light escapes from the sintered body, and the light emitted includes light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum becomes less than 0.005, and the relative luminous flux is low.

[0183] Example 5-1 to Example 5-4

[0184] Sintered bodies were obtained in the same manner as in Examples 1-1 to 1-3 except that nitride phosphor 5 was used, and sintered bodies of Examples 5-1 to 5-4 were obtained so as to have thicknesses shown in Table 10. Each sintered body was set to an irradiation light source having a peak wavelength of 450 nm and an output of 1300 mW / mm 2 Above and 6000mW / mm2 Within the following range, specifically 1300mW / mm 2 Above and 1500mW / mm 2 The light emitting device for the test was a light emitting element (LED) that irradiated light with excitation light within the following range. The above-mentioned measurement was performed on each light emitting device of Example 5-1 to Example 5-4. The results are shown in Table 10.

[0185] [Table 10]

[0186]

[0187] Each light-emitting device using each sintered body of Example 5-1 to Example 5-4 emits light having a hue within region A1, including light obtained by wavelength conversion of excitation light by the phosphor contained in the sintered body and excitation light transmitted through the sintered body, and light emitted from the sintered body having an integral value ratio Z2 / Z1 of 0.005 or more in the emission spectrum, wherein excitation light having a shorter wavelength than the light obtained by wavelength conversion of the phosphor contained in the sintered body is separated from the sintered body. Each light-emitting device of Example 5-1 to Example 5-4 emits light having an amber hue on the shorter wavelength side within region A1, and emits light with a relatively high luminous flux.

[0188] Fig.14 This is a diagram showing the chromaticity coordinates (x, y) of the light emitted by the light emitting devices using the sintered bodies of Examples 5-1 to 5-4, and regions A1, A2, and A3 in the chromaticity diagram of the CIE1931 color system. Fig.14 As shown, each of the light emitting devices of Example 5-1 to Example 5-4 emits light having an amber hue within the range of A3 on the shorter wavelength side even within the area A1.

[0189] Each sintered body used in each light-emitting device of Examples 5-1 to 5-4 includes a nitride phosphor having a composition represented by the above formula (I), wherein M 2 Eu, w satisfies 0.001≤w<0.0025, more specifically, satisfies 0.001≤w≤0.002, and the thickness of the sintered body is within the range of 150μm to 250μm, more specifically, the thickness of the sintered body is within the range of 180μm to 250μm. Each light emitting device of Examples 5-1 to 5-4 using these sintered bodies emits the following light: excitation light having a wavelength shorter than that of light obtained by wavelength conversion of the phosphor contained in the sintered body is separated from the sintered body, light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and excitation light after passing through the sintered body, and light emitted from the sintered body has an integral value ratio Z2 / Z1 of 0.005 or more in the emission spectrum, and is high in relative luminous flux.

[0190] Fig.15 is a SEM photograph showing a fracture surface obtained by fracture of the sintered body used in the light emitting device of Example 5-1. Fig.15 As shown, in the fracture surface of the sintered body used in the light-emitting device of Example 5-1, individual phosphor particles can be confirmed, and it can be confirmed that the major diameter of the phosphor particles is within the range of 0.1 μm to 20 μm. In the SEM photograph of the fracture surface obtained by breaking the sintered body used in the light-emitting device of Example 5-1, the longest diameter from one end of the outline of the phosphor particle where the outline can be confirmed through the inside of the phosphor particle to the other end of the phosphor particle, that is, the major diameter of the phosphor particle is about 10 μm. Fig.15 In the photograph shown, the phosphor particles in the sintered body are larger than the phosphor particles as the raw material, and the particle growth of the phosphor particles is promoted.

[0191] Example 6-1 to Example 6-4

[0192] The sintered bodies of Examples 6-1 to 6-4 were obtained in the same manner as in Examples 1-1 to 1-3 except that the nitride phosphor 6 was used, and the sintered bodies were obtained in such a manner as to have the thicknesses shown in Table 11. The sintered bodies were set to irradiate with a peak emission wavelength of 450 nm and an output of 1300 mW / mm 2 Above and 6000mW / mm 2 Within the following range, specifically 1300mW / mm 2 Above and 1500mW / mm 2 The light emitting device for the test was a light emitting element (LED) that irradiated light with excitation light within the following range. The above-mentioned measurement was performed on each light emitting device for the test of Example 6-1 to Example 6-4. The results are shown in Table 11.

[0193] [Table 11]

[0194]

[0195] Each light-emitting device using each sintered body of Example 6-1 to Example 6-4 emits light having a hue within the range of region A1, including light obtained by wavelength conversion by the phosphor contained in the sintered body and excitation light transmitted through the sintered body, and the integral value ratio Z2 / Z1 of the light emitted from the sintered body in the emission spectrum is 0.005 or more, wherein the excitation light having a shorter wavelength than the light obtained by wavelength conversion by the phosphor contained in the sintered body is separated from the sintered body. Each light-emitting device of Example 6-1 to Example 6-4 emits light having an amber hue on the shorter wavelength side within region A1 and having a high relative luminous flux.

[0196] Fig.16 This is a diagram showing the chromaticity coordinates (x, y) of the light emitted by the light emitting devices using the sintered bodies of Examples 6-1 to 6-4, and regions A1, A2, and A3 in the chromaticity diagram of the CIE1931 color system. Fig.16 As shown, each of the light emitting devices of Example 6-1 to Example 6-4 emits light having an amber hue within the range of A3 on the shorter wavelength side even within the area A1.

[0197] Each sintered body used in the light-emitting devices of Examples 6-1 to 6-4 contains a nitride phosphor having a composition represented by the above formula (I), wherein M 2 Eu, w satisfies 0.001≤w<0.005, more specifically, satisfies 0.003≤w≤0.0045, and the thickness of the sintered body is within the range of 80μm to 250μm, more specifically, the thickness of the sintered body is within the range of 100μm to 200μm. Each light emitting device of Examples 6-1 to 6-4 using these sintered bodies emits the following light: excitation light having a wavelength shorter than that of light obtained by wavelength conversion of the phosphor contained in the sintered body is separated from the sintered body, light obtained by wavelength conversion of the excitation light by the phosphor contained in the sintered body and excitation light after passing through the sintered body, and light emitted from the sintered body has an integral value ratio Z2 / Z1 of 0.005 or more in the emission spectrum, and is high in relative luminous flux.

[0198] Industrial Applicability

[0199] The sintered body of the present application can be used as a wavelength conversion member capable of converting the wavelength of light emitted from an LED or LD. A light-emitting device using the sintered body can be used for vehicle-mounted use, general lighting, backlights of liquid crystal display devices, lighting, light sources for projectors, etc. In addition, the sintered body used in the light-emitting device can also emit light by irradiation with excitation light and be used as a material for a solid scintillator.

Claims

1. A sintered body comprising at least one phosphor selected from a nitride phosphor having a composition represented by the following formula (I) and an α-sialon phosphor having a composition represented by the following formula (II), In the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) are (x=0.549, y=425) as point 1a, (x=0.562, y=0.438) as point 2a, (x=0.589, y=0.411) as point 3a, and (x=0.576, y=0.407) as point 4a. An area A1 is defined by a first straight line connecting the points 1a and 2a, a second straight line connecting the points 2a and 3a, a third straight line connecting the points 3a and 4a, and a fourth straight line connecting the points 4a and 1a. When the sintered body is irradiated with excitation light, light having a hue within the area A1 is emitted. The peak wavelength of irradiated light is 450nm and the output is 1300mW / mm 2 Above and 6000mW / mm 2 When the excitation light is within the following range, the light emitted by the sintered body includes light obtained by wavelength conversion of the excitation light by the fluorescent body contained in the sintered body and the excitation light after passing through the sintered body, and the integral value ratio Z2 / Z1 of the second integral value Z2 in the wavelength range of 400nm to 500nm of the light emitted from the sintered body to the first integral value Z1 in the wavelength range of more than 500nm and less than 800nm ​​in the emission spectrum is 0.005 or more, (Ba 1-u-w M 1 u M 2 w )2Si5N8(I) In the formula (I), M 1 is at least one element selected from Sr, Ca and Mg, M 2 is at least one element selected from Eu, Ce, Tb and Mn, and u and w satisfy 0<u≤0.5, 0.001≤w<0.5, respectively. M 3 q And 12-(r+s) the r+s A s N 16-s :I t (II) In the formula (II), M3 is at least one element selected from Li, Mg, Ca, Sr, Y and lanthanide elements, the lanthanide elements do not include La and Ce, and q, r, s and t respectively satisfy 0<q≤2.0, 2.0≤r≤6.0, 0≤s≤1.0, 0.001≤t≤0.

5.

2. The sintered body according to claim 1, wherein The integral value ratio Z2 / Z1 is greater than or equal to 0.

008.

3. The sintered body according to claim 1 or 2, wherein The integral value ratio Z2 / Z1 is within the range of 0.01 to 0.

04.

4. The sintered body according to any one of claims 1 to 3, wherein The sintered body is produced by sintering phosphor particles having an average particle size Db of less than 1 μm as measured by a Fisher sub-sieve particle sizer method.

5. The sintered body according to any one of claims 1 to 4, wherein The sintered body is produced by sintering phosphor particles having a particle size ratio Db / Dm of 0.45 or less, where the average particle size Db measured by the Fisher sub-sieve particle size analyzer method is relative to the volume median particle size Dm measured by the laser diffraction particle size distribution measurement method. 6 . The sintered body according to claim 1 , which has a relative density of 97% or more. 7 . The sintered body according to claim 1 , which has a thickness in the range of 30 μm to 300 μm.

8. The sintered body according to any one of claims 1 to 7, wherein In the area A1, in the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) are (x=0.549, y=425) as point 1a, (x=0.557, y=0.433) as point 2a', (x=0.582, y=0.409) as point 3a', and (x=0.576, y=0.407) as point 4a. Area A2 is defined by the 1' straight line connecting the 1a and 2a' points, the 2' straight line connecting the 2a' point and the 3a' point, the 3' straight line connecting the 3a' point and the 4a point, and the 4th straight line connecting the 4a point and the 1a point. When the sintered body is irradiated with excitation light, it emits light having the hue within the area A2.

9. The sintered body according to any one of claims 1 to 8, wherein In the area A1, in the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) are (x=0.549, y=425) as point 1a, (x=0.557, y=0.433) as point 2a', (x=0.579, y=0.412) as point 3a", and (x=0.569, y=0.412) as point 4a". Area A3 is defined by a 1" straight line connecting the 1a and 2a' points, a 2" straight line connecting the 2a' point and the 3a" point, a 3" straight line connecting the 3a" point and the 4a" point, and a 4" straight line connecting the 4a" point and the 1a point. When the sintered body is irradiated with excitation light, it emits light having the hue within the area A3.

10. The sintered body according to any one of claims 1 to 9, wherein the thickness is within a range of 50 μm to 250 μm. The sintered body includes a first nitride phosphor having a composition represented by the formula (I), In the formula (I), M 2 is Eu, and w satisfies 0.001≤w<0.

01.

11. The sintered body according to any one of claims 1 to 9, wherein the thickness is within a range of 80 μm to 250 μm. The sintered body includes a first nitride phosphor having a composition represented by the formula (I), In the formula (I), M 2 is Eu, and w satisfies 0.001≤w<0.

005.

12. The sintered body according to any one of claims 1 to 9, wherein the thickness thereof is in the range of 100 μm to 200 μm. The sintered body includes a first nitride phosphor having a composition represented by the formula (I), In the formula (I), M 2 is Eu, and w satisfies 0.003≤w≤0.0045.

13. The sintered body according to any one of claims 1 to 9, wherein the thickness is within a range of 120 μm to 250 μm. The sintered body includes a first nitride phosphor having a composition represented by the formula (I), In the formula (I), M 2 is Eu, and w satisfies 0.001≤w<0.0035.

14. The sintered body according to any one of claims 1 to 9, wherein the thickness is within a range of 130 μm to 183 μm. The sintered body includes a first nitride phosphor having a composition represented by the formula (I), In the formula (I), M 2 is Eu, and w satisfies 0.002≤w≤0.

003.

15. The sintered body according to any one of claims 1 to 9, wherein the thickness is within a range of 150 μm to 250 μm. The sintered body includes a first nitride phosphor having a composition represented by the formula (I), In the formula (I), M 2 is Eu, and w satisfies 0.001≤w<0.0025.

16. The sintered body according to any one of claims 1 to 9, wherein the thickness is within a range of 180 μm to 250 μm. The sintered body includes a first nitride phosphor having a composition represented by the formula (I), In the formula (I), M 2 is Eu, and w satisfies 0.001≤w≤0.

002.

17. The sintered body according to any one of claims 1 to 16, comprising a first nitride phosphor having a composition represented by the formula (I), In the formula (I), u satisfies 0.25≤u≤0.

45.

18. A light emitting device comprising: an excitation light source that emits light having a peak emission wavelength in a range of 380 nm to 570 nm, and The sintered body according to any one of claims 1 to 17, arranged at a position where light is irradiated from the excitation light source.

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