Sintered body and light-emitting device

Abstract

To provide a sintered body and a light-emitting device.SOLUTION: A sintered body contains at least one phosphor selected from the group consisting of a nitride phosphor having the composition of a formula (I) and a α sialon phosphor having the composition of a formula (II). When excitation light is radiated, light which has color tone in a region A1 defined by a line connecting a point 1a (x=0.549, y=0.425), a point 2a (x=0.562, y=0.438), a point 3a (x=0.589, y=0.411) and a point 4a (x=0.576, y=0.407) in a chromaticity diagram of a CIE1931 color system, and in which an integral value ratio Z2 / Z1 between a first integral value Z1 exceeding 500 nm and 800 nm or less and a second integral value Z2 of 400 nm or more 500 nm or less is 0.005 or more in an emission spectrum of light emitted from a sintered body including light in which excitation light is wavelength-converted by a phosphor contained in a sintered body when excitation light is radiated and excitation light which passed through the sintered body is emitted.SELECTED DRAWING: Figure 10

Description

Technical Field

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

Background Art

[0002] Some light-emitting devices using light-emitting elements such as LEDs and LDs are configured by combining a light-emitting element as an excitation light source and a member containing a phosphor that absorbs a 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 as light sources for in-vehicle use, general lighting, backlights for liquid crystal display devices, illumination, projectors, and the like.

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

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a sintered body containing a fluoride inorganic binder and a nitride phosphor, the fluoride inorganic binder and the nitride phosphor may react during firing. The light emission by irradiation of excitation light on the sintered body containing the nitride phosphor that has reacted with the fluoride inorganic binder may result in a low light flux and a deterioration in light emission characteristics. An object of the present disclosure is to provide a sintered body that emits light having a high light flux upon irradiation with excitation light and a light-emitting device using the same.

Means for Solving the Problems

[0006] The first aspect is a sintered body containing at least one phosphor selected from the group consisting of 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). When irradiated with excitation light, in the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) are such that (x = 0.549, y = 0.425) is the first a point, (x = 0.562, y = 0.438) is the second a point, (x = 0.589, y = 0.411) is the third a point, (x = 0.576, y = 0.407) is the fourth a point, and the color tone is within the range of the region A1 defined by the first straight line connecting the first a point and the second a point, the second straight line connecting the second a point and the third a point, the third straight line connecting the third a point and the fourth a point, and the fourth straight line connecting the fourth a point and the first a point. The emission peak wavelength is 450 nm, and 1300 mW / mm 2 above 6000 mW / mm 2 When irradiated with excitation light having an output within the following range, in the emission spectrum of the light emitted from the sintered body, which includes the light whose wavelength has been converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body, the integral value ratio Z2 / Z1 of the second integral value Z2 in the wavelength range of 400 nm or more and 500 nm or less to the first integral value Z1 in the wavelength range of more than 500 nm and 800 nm or less is 0.005 or more. The sintered body emits light. (Ba 1-u-w M 1 u M 2 w ) 2 Si 5 N 8 (I) (In the above formula (I), M 1 is at least one element selected from the group consisting of Sr, Ca, and Mg, and M 2 is at least one element selected from the group consisting of Eu, Ce, Tb, and Mn. u and w each satisfy 0 < u ≦ 0.5 and 0.001 ≦ w < 0.5.) M 3 q Si 12-(r+s) Al r+s O s N 16-s :Eu t (II) (In the formula (II), M 3 is at least one element selected from the group consisting of Li, Mg, Ca, Sr, Y, and lanthanoid elements (excluding La and Ce), and q, r, s, and t satisfy 0 < q ≤ 2.0, 2.0 ≤ r ≤ 6.0, 0 ≤ s ≤ 1.0, and 0.001 ≤ t ≤ 0.5, respectively.)

[0007] A second aspect is a light-emitting device including an excitation light source that emits light having an emission peak wavelength in the range of 380 nm or more and 570 nm or less, and the sintered body disposed at a position irradiated with light from the excitation light source.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to provide a sintered body that emits light having a high luminous flux upon irradiation with excitation light, and a light-emitting device using the same.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Mode for Carrying Out the Invention

[0010] Hereinafter, the sintered body and the light-emitting device according to the present disclosure will be described. However, the following embodiments are examples for embodying the technical idea of the present invention, and the present invention is not limited to the following sintered body and light-emitting device. 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 Z8110.

[0011] The sintered body is a sintered body containing at least one phosphor selected from the group consisting of a nitride phosphor having a composition represented by formula (I) and an α-sialon phosphor having a composition represented by formula (II). When irradiated with excitation light, in the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) have (x = 0.549, y = 0.425) as the first a point, (x = 0.562, y = 0.438) as the second a point, (x = 0.589, y = 0.411) as the third a point, (x = 0.576, y = 0.407) as the fourth a point, the first straight line connecting the first a point and the second a point, the second straight line connecting the second a point and the third a point, the third straight line connecting the third a point and the fourth a point, and the fourth straight line connecting the fourth a point and the first a point, and has a color tone within the range of region A1 defined by them, the emission peak wavelength is 450 nm, and 1300 mW / mm 2 above 6000 mW / mm 2 When irradiated with excitation light having an output within the following range, in the emission spectrum of the light emitted from the sintered body including the light whose wavelength is converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body, the integral value ratio Z2 / Z1 of the second integral value Z2 in the wavelength range of 400 nm or more and 500 nm or less to the first integral value Z1 in the wavelength range of more than 500 nm and 800 nm or less is 0.005 or more, and light is emitted.

[0012] The sintered body has an emission peak wavelength of 450 nm and 1300 mW / mm 2 above 6000 mW / mm 2When irradiated with excitation light having an output within the following range, light is emitted that includes light whose wavelength has been converted by a phosphor contained in the sintered body and excitation light that has passed through the sintered body. In the emission spectrum of the light emitted from the sintered body, the emission spectrum within the wavelength range exceeding 500 nm and equal to or less than 800 nm represents the emission spectrum of the light whose wavelength has been converted by the phosphor contained in the sintered body when irradiated with excitation light, and the emission spectrum within the wavelength range of 400 nm or more and 500 nm or less represents the emission spectrum of the excitation light that has passed through the sintered body. The sintered body has an emission peak wavelength of 450 nm and 1300 mW / mm 2 or more and 6000 mW / mm 2 When irradiated with excitation light having an output within the following range, in the emission spectrum of the light emitted from the sintered body, light is emitted such that the integral value ratio Z2 / Z1 of the second integral value Z2 within the wavelength range of 400 nm or more and 500 nm or less to the first integral value Z1 within the wavelength range exceeding 500 nm and equal to or less than 800 nm is 0.005 or more. The sintered body irradiated with the excitation light includes, together with the light whose wavelength has been converted by the phosphor contained in the sintered body, the light in which the excitation light irradiated to the sintered body is dispersed in the sintered body and exits through the sintered body, thereby having a color tone within region A1 and emitting light with a high luminous flux. It is presumed that the sintered body irradiated with the excitation light emits light with an integral value ratio Z2 / Z1 of 0.005 or more in the emission spectrum of the light emitted from the sintered body and a high luminous flux because the phosphor particles in the sintered body have become larger, reducing the interfaces within the sintered body composed of the phosphor particles and increasing the light extraction efficiency.

[0013] The sintered body has an emission peak wavelength of 450 nm and 1300 mW / mm 2 or more and 6000 mW / mm 2When excited light within the following range is irradiated, the excited light is wavelength-converted by the phosphor contained in the sintered body, and the light emitted from the sintered body includes the wavelength-converted light and the excited light transmitted through the sintered body. It is preferable that the integral value ratio Z2 / Z1 of the second integral value Z2 in the wavelength range of 400 nm or more and 500 nm or less to the first integral value Z1 in the wavelength range of more than 500 nm and 800 nm or less in the emission spectrum of the light emitted from the sintered body is 0.008 or more, more preferably 0.009 or more, and even more preferably 0.01 or more. When the sintered body is irradiated with the aforementioned excited light, light with an integral value ratio Z2 / Z1 of 0.04 or less in the emission spectrum of the light emitted from the sintered body may be emitted, preferably within the range of 0.005 or more and 0.04 or less, more preferably within the range of 0.008 or more and 0.04 or less, and even more preferably within the range of 0.01 or more and 0.04 or less. When the sintered body is irradiated with the aforementioned excited light, light with an integral value ratio Z2 / Z1 of 0.03 or less in the emission spectrum of the light emitted from the sintered body may be emitted, and light with an integral value ratio Z2 / Z1 of 0.02 or less may also be emitted. If the sintered body emits light with an integral value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body exceeding 0.04 and being large when irradiated with the aforementioned excited light, too much excited light on the short-wavelength side transmitted through the sintered body will result in light without the color tone within region A1 being emitted from the sintered body.

[0014] Figure 1 shows an example of the emission spectrum of light emitted from a sintered body when irradiated with excited light having an output within the range of a peak emission wavelength of 450 nm and 1300 mW / mm 2 or more and 6000 mW / mm 2 or less. The light emitted from the sintered body includes the light whose wavelength is converted by the phosphor contained in the sintered body and the excited light transmitted through the sintered body when irradiated with the excited light within the above range.

[0015] In the emission spectrum of the light emitted from the sintered body shown in FIG. 1, which includes the light whose wavelength is converted by the phosphor contained in the sintered body when irradiated with excitation light and the excitation light transmitted through the sintered body when irradiated with excitation light, the first integral value Z1 in the wavelength range exceeding 500 nm and equal to or less than 800 nm is the integral value of the range of the wavelength width surrounded by the emission spectrum of the sintered body in the wavelength range exceeding 500 nm and equal to or less than 800 nm, with the horizontal axis where the emission intensity (a.u. (arbitrary value)) is 0 (zero). In the emission spectrum of the light emitted from the sintered body shown in FIG. 1, the second integral value Z2 in the wavelength range of 400 nm or more and 500 nm or less is the integral value of the range of the wavelength width surrounded by the emission spectrum of the light emitted from the sintered body in the range of 400 nm or more and 500 nm or less, with the horizontal axis where the emission intensity (a.u.) is 0. In the emission spectrum of the light emitted from the sintered body when irradiated with excitation light, when the emission spectrum of the light emitted from the sintered body in the wavelength range exceeding 500 nm and equal to or less than 800 nm does not touch the horizontal axis where the emission intensity is 0, the straight line extending vertically from a wavelength of 500 nm with respect to the horizontal axis where the emission intensity is 0, the straight line extending vertically from a wavelength of 800 nm with respect to the horizontal axis where the emission intensity is 0, the horizontal axis where the emission intensity is 0, and the integral value of the range of the wavelength width surrounded by the emission spectrum of the light emitted from the sintered body in the wavelength range exceeding 500 nm and equal to or less than 800 nm are defined as Z1. In the emission spectrum of the light emitted from the sintered body when irradiated with excitation light, when the emission spectrum of the light emitted from the sintered body in the wavelength range of 400 nm or more and 500 nm or less does not touch the horizontal axis where the emission intensity is 0, the straight line extending vertically from a wavelength of 400 nm with respect to the horizontal axis where the emission intensity is 0, the straight line extending vertically from a wavelength of 500 nm with respect to the horizontal axis where the emission intensity is 0, the horizontal axis where the emission intensity is 0, and the integral value of the range of the wavelength width surrounded by the emission spectrum of the light emitted from the sintered body in the wavelength range of 400 nm or more and 500 nm or less are defined as Z2.

[0016] In the chromaticity diagram of the CIE (Commission Internationale de l’Eclairage: International Commission on Illumination) 1931 color system, the region A1 is light having a hue within region A that meets the requirements for amber (orange) color specified by the ECE (United Nations Economic Commission for Europe) standard. In this specification, the amber color includes orange. Light having a hue within region A that meets the requirements for the amber color specified by the ECE standard is emitted from a direction indicator (turn signal lamp, winkers) in vehicle lamps such as rear combination lamps mounted on a vehicle. Region A that meets the requirements for the amber color specified by the ECE standard is, in the chromaticity diagram of the CIE 1931 color system, the first as point at (x = 0.545, y = 0.425), the second as point at (x = 0.560, y = 0.440), the third as point at (x = 0.609, y = 0.390), the fourth as point at (x = 0.597, y = 0.390), the first s straight line connecting the first as point and the second as point, the second s straight line connecting the second as point and the third as point, the third s straight line connecting the third as point and the fourth as point, and the fourth s straight line connecting the fourth as point and the first as point. Figure 2 shows region A that meets the requirements for the amber color specified by the ECE standard in the chromaticity diagram of the CIE 1931 color system. Table 1 shows the chromaticity coordinates of the first as point, the second as point, the third as point, and the fourth as point indicating region A.

[0017]

Table 1

[0018] When the sintered body is irradiated with excitation light, light including the light whose wavelength is converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is emitted. The light emitted from the sintered body has a color tone within a region A1 defined by a first straight line connecting a first point a (x = 0.549, y = 0.425), a second straight line connecting a second point a (x = 0.562, y = 0.438), a third straight line connecting a third point a (x = 0.589, y = 0.411), and a fourth straight line connecting a fourth point a (x = 0.576, y = 0.407) in the chromaticity diagram of the CIE1931 color system. FIG. 3 shows the region A1 in the chromaticity diagram of the CIE1931 color system. Table 2 shows the chromaticity coordinates of the first point a, the second point a, the third point a, and the fourth point a indicating the region A1.

[0019]

Table 2

[0020] When the sintered body is irradiated with excitation light, light including the light whose wavelength is converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is emitted. The light emitted from the sintered body preferably has a color tone within a region A2 defined by a first straight line' connecting a first point a (x = 0.549, y = 0.425), a second straight line' connecting a second point a' (x = 0.557, y = 0.433), a third straight line' connecting a third point a' (x = 0.582, y = 0.409), and a fourth straight line connecting a fourth point a (x = 0.576, y = 0.407) in the chromaticity diagram of the CIE1931 color system. When light having a color tone within the region A2 is emitted from the sintered body, light having a color tone within the region A1 and having more light on the shorter wavelength side is obtained. FIG. 4 shows the region A2 in the chromaticity diagram of the CIE1931 color system. Table 3 shows the chromaticity coordinates of the first point a, the second point a', the third point a', and the fourth point a indicating the region A2.

[0021]

Table 3

[0022] When the sintered body is irradiated with excitation light, light including light whose wavelength is converted by the phosphor contained in the sintered body and excitation light transmitted through the sintered body is emitted. The light emitted from the sintered body has a color tone within a region A3 defined by a first straight line connecting a first a point (x = 0.549, y = 0.425), a second a' point (x = 0.557, y = 0.433), a third a'' point (x = 0.579, y = 0.412), and a fourth a'' point (x = 0.569, y = 0.412) in the chromaticity diagram of the CIE1931 color system. When light having a color tone within the region A3 is emitted from the sintered body, light having a color tone within the regions A1 and A2 and having more light on the shorter wavelength side is obtained. FIG. 5 shows the region A3 in the chromaticity diagram of the CIE1931 color system. Table 4 shows the chromaticity coordinates of the first a point, the second a' point, the third a'' point, and the fourth a'' point indicating the region A3.

[0023]

Table 4

[0024] FIG. 6 shows a region A that satisfies the requirements of the amber color defined by the ECE standard, and regions A1, A2, and A3 in the chromaticity diagram of the CIE1931 color system. The regions A1, A2, and A3 are within the region A that satisfies the requirements of the amber color defined by the ECE standard and have a color tone on the shorter wavelength side within the region A. The region A2 is a region to the left of a second straight line connecting a second a' point (x = 0.557, y = 0.433) and a third a' point (x = 0.582, y = 0.409) within the range of the region A1 in the chromaticity diagram of the CIE color system. The region A3 has a color tone on the shorter wavelength side than the regions A1 and A2.

[0025] The sintered body contains at least one phosphor selected from the group consisting of 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). (Ba 1-u-w M 1 u M 2 w ) 2 Si 5 N 8 (I) (In the above formula (I), M 1 is at least one element selected from the group consisting of Sr, Ca, and Mg, M 2 is at least one element selected from the group consisting of Eu, Ce, Tb, and Mn, and u and w each satisfy 0 < u ≦ 0.5 and 0.001 ≦ w < 0.5.) M 3 q Si 12-(r+s) Al r+s O s N 16-s :Eu t (II) (In the above formula (II), M 3 is at least one element selected from the group consisting of Li, Mg, Ca, Sr, Y, and lanthanoid elements (excluding La and Ce), and q, r, s, and t each satisfy 0 < q ≦ 2.0, 2.0 ≦ r ≦ 6.0, 0 ≦ s ≦ 1.0, and 0.001 ≦ t ≦ 0.5.)

[0026] The sintered body preferably 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 different composition from the composition represented by the above formula (I) or the composition represented by the above formula (II). The sintered body may contain only a nitride phosphor having a composition represented by the above formula (I). The sintered body may 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).

[0027] In the nitride phosphor, in the composition represented by the formula (I), the element M 1 is an element that constitutes a crystal structure serving as a host crystal together with Ba. In 1 mol of the composition represented by the formula (I) of the nitride phosphor, the element M 1 The molar ratio of is represented by the product of 2 and the variable u. In the formula (I), the variable u is in the range exceeding 0 and equal to or less than 0.5 (0 < u ≤ 0.5), and may be in the range of 0.1 or more and 0.48 or less (0.1 ≤ u ≤ 0.48), or may be in the range of 0.2 or more and 0.45 or less (0.2 ≤ u ≤ 0.45), and preferably in the range of 0.25 or more and 0.45 or less (0.25 ≤ u ≤ 0.45). In the composition of the nitride phosphor, the element M 1 that constitutes a crystal structure serving as a host crystal together with Ba affects the emission characteristics and color tone including the luminous flux of the sintered body irradiated with excitation light. In the nitride phosphor, in the composition represented by the formula (I), when the variable u in the product of 2 and the variable u representing the molar ratio of the element M 1 is in the range exceeding 0 and equal to or less than 0.5, preferably in the range of 0.25 or more and 0.45 or less, light is emitted from the sintered body including the nitride phosphor, in which the irradiated excitation light is wavelength-converted by the nitride phosphor and has a color tone within the region A1, and the integral value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light wavelength-converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more.

[0028] In the nitride phosphor, in the composition represented by the formula (I), the element M 2 is an activating element. In 1 mol of the composition represented by the formula (I) of the nitride phosphor, the activating element M 2The molar ratio is represented by the product of 2 and the variable w. In the formula (I), the variable w is in the range of 0.001 or more and less than 0.5 (0.001 ≦ w < 0.5), and may be in the range of 0.001 or more and less than 0.1 (0.001 ≦ w < 0.1), may be in the range of 0.001 or more and less than 0.05 (0.001 ≦ w < 0.05), may be in the range of 0.001 or more and less than 0.01 (0.001 ≦ w < 0.01), may be in the range of 0.001 or more and less than 0.005 (0.001 ≦ w < 0.005), may be in the range of 0.001 or more and less than 0.0035 (0.001 ≦ w < 0.0035), or may be in the range of 0.001 or more and less than 0.0025 (0.001 ≦ w < 0.0025). In the composition of the nitride phosphor, the molar ratio of the activating element affects the emission characteristics and color tone including the luminous flux of the sintered body irradiated with excitation light. The nitride phosphor has, in the composition represented by the formula (I), the element M which is the activating element 2 When the molar ratio of 2 is large, the emission intensity becomes high when irradiated with excitation light. A sintered body containing a phosphor having a high emission intensity when irradiated with excitation light can be a sintered body with a small thickness. In a sintered body with a small thickness, light is easily extracted in the thickness direction of the sintered body. Specifically, in this specification, in the composition represented by the formula (I), the element M which is the activating element 2 is Eu, and when the thickness of a sintered body composed only of a nitride phosphor in which the variable w of the product of 2 representing the molar ratio of Eu is in the range of 0.001 or more and less than 0.5, the sintered body has a small thickness. In a sintered body with a small thickness, when irradiated with excitation light, light including the light obtained by wavelength-converting the excitation light by the phosphor contained in the sintered body with a small thickness and the excitation light transmitted through the sintered body is emitted, the light emitted from the sintered body has a color tone within the region A1, and the integral value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body is 0.005 or more. Also, the nitride phosphor has, in the composition represented by the formula (I), the element M which is the activating element 2When the molar ratio is small, the emission intensity becomes low when irradiated with excitation light. A sintered body containing a phosphor with low emission intensity when irradiated with excitation light can be a thick sintered body. A thick sintered body can be a sintered body with high mechanical strength. In this specification, specifically, in the composition represented by the formula (I), the element M which is an activating element 2 is Eu, and when the variable w of the product of 2 representing the molar ratio of Eu and the variable w is in the range of 0.001 or more and less than 0.5, when the thickness of the sintered body consisting only of the nitride phosphor exceeds 220 μm, it is said that the sintered body is thick. When a thick sintered body is irradiated with excitation light, light including the light whose wavelength is converted by the phosphor contained in the thick sintered body and the excitation light transmitted through the sintered body is emitted, having the color tone in the region A, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body is 0.005 or more. However, when the thickness of the sintered body is too thick, for example, exceeds 300 μm, the excitation light coming out of the sintered body is small, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light whose wavelength is converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is less than 0.005, and there may be a case where light with a low relative luminous flux is emitted. Therefore, the thickness of the sintered body is preferably 300 μm or less.

[0029] The nitride phosphor having the composition represented by the formula (I) may contain Eu as the element M 2 and have the composition represented by the following formula (I-1). (Ba 1-u-w M 1 u Eu w ) 2 Si 5 N 8 (I-1) (In the formula (I-1), M 1 is at least one element selected from the group consisting of Sr, Ca, and Mg, and u and w satisfy 0 < u ≦ 0.5 and 0.001 ≦ w < 0.5, respectively.)

[0030] The nitride phosphor having the composition represented by the formula (I) has the element M 1It may have a composition represented by the following formula (I-2) containing Sr as [element M]. (Ba 1-u-w Sr u M 2 w ) 2 Si 5 N 8 (I-2) (In the formula (I-2), M 2 is at least one element selected from the group consisting of Eu, Ce, Tb, and Mn, and u and w satisfy 0 < u ≤ 0.5 and 0.001 ≤ w < 0.5, respectively.)

[0031] The nitride phosphor having the composition represented by the formula (I) may contain Sr as element M 1 and may have a composition represented by the following formula (I-3) containing Eu as element M 2 . (Ba 1-u-w Sr u Eu w ) 2 Si 5 N 8 (I-3) (In the formula (I-3), M 1 is at least one element selected from the group consisting of Sr, Ca, and Mg, and u and w satisfy 0 < u ≤ 0.5 and 0.001 ≤ w < 0.5, respectively.)

[0032] The sintered body preferably has a relative density of 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 group consisting of a nitride phosphor having the composition represented by the above formula (I) and an α-sialon phosphor having the composition represented by the above formula (II) emits light having a color tone within region A1 when irradiated with excitation light. The sintered body preferably has a relative density of 99.7% or less, more preferably 99.5% or less. If the relative density of the sintered body is 99.7% or less, the numerical value obtained by subtracting the relative density from 100% is the porosity. If the relative density of the sintered body is 97% or more, light scattering due to voids in the sintered body is suppressed, light extraction is good, and the light emitted from the sintered body includes the light whose wavelength is converted by the phosphor contained in the sintered body with the excitation light and the excitation light transmitted through the sintered body, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body is 0.005 or more, and light with a high luminous flux is emitted.

[0033] The sintered body preferably contains only a nitride phosphor and has a relative density in the range of 97% or more and 99.7% or less. When the sintered body contains only a nitride phosphor and has a relative density in the range of 97% or more and 99.7% or less, the sintered body has a color tone within region A1 when irradiated with excitation light, and the light emitted from the sintered body includes the light whose wavelength is converted by the phosphor contained in the sintered body with the excitation light and the excitation light transmitted through the sintered body, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body is 0.005 or more, and light with a high luminous flux is emitted.

[0034] The relative density of the sintered body refers to the value calculated from the apparent density of the sintered body with respect to the true density of the sintered body. The relative density of the sintered body is calculated from the following calculation formula (1).

[0035]

Number

[0036] The true density of the sintered body refers to the value obtained by multiplying the mass ratio (%) of the phosphor by the true density of the phosphor with respect to 100% by mass of the sintered body. When the sintered body is formed from a molded body composed of only one type of phosphor, the true density of the phosphor becomes the true density of the sintered body. Degree.

[0037] The apparent density of the sintered body is the value obtained by dividing the mass of the sintered body by the volume of the sintered body determined 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 determined by the Archimedes method.

[0038]

Number

[0039] The sintered body preferably has a thickness in the range of 30 μm or more and 300 μm or less. When the thickness of the sintered body is in the range of 30 μm or more and 300 μm or less, the irradiated excitation light is scattered in the sintered body and wavelength-converted efficiently by the phosphor, and the irradiated excitation light is transmitted, having the color tone in region A1. The light emitted from the sintered body includes the light whose wavelength has been converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body, and the integral value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body is 0.005 or more, and light with a high luminous flux is emitted. Further, when the thickness of the sintered body is in the range of 30 μm or more and 300 μm or less, it has sufficient mechanical strength.

[0040] The sintered body contains a nitride phosphor having the composition represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.001 ≦ w < 0.05, it preferably has a thickness in the range of 50 μm or more and 180 μm or less. The sintered body contains a nitride phosphor represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.005 ≦ w ≦ 0.01, it may have a thickness in the range of 50 μm or more and 120 μm or less. In the composition represented by the formula (I), the element M which is an activating element 2A nitride phosphor with a large molar ratio of [substance] emits a high emission intensity when irradiated with excitation light. When the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably in the range of 50 μm or more and 250 μm or less, more preferably in the range of 50 μm or more and 120 μm or less, the sintered body has a color tone within region A1 when irradiated with excitation light, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body containing the light whose wavelength has been converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more.

[0041] The sintered body contains a nitride phosphor having the composition represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.001 ≦ w < 0.01, it is preferable that the thickness is in the range of 50 μm or more and 250 μm or less. The sintered body contains a nitride phosphor represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.001 ≦ w < 0.01, the thickness may be in the range of 55 μm or more and 240 μm or less, or may be in the range of 60 μm or more and 230 μm or less. In the composition represented by the formula (I), the element M which is an activating element 2 A nitride phosphor with a large molar ratio of [substance] emits a high emission intensity when irradiated with excitation light. When the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably in the range of 50 μm or more and 250 μm or less, the sintered body has a color tone within region A1 when irradiated with excitation light, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body containing the light whose wavelength has been converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more.

[0042] The sintered body contains a nitride phosphor having the composition represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.001 ≦ w < 0.005, it is preferable that the thickness is in the range of 80 μm or more and 250 μm or less. The sintered body contains a nitride phosphor represented by the formula (I), and in the formula (I), M 2When M is Eu and 0.001 ≤ w < 0.005, it is more preferable that the thickness is in the range of 90 μm or more and 240 μm or less, and it is even more preferable that the thickness is in the range of 100 μm or more and 230 μm or less. For a nitride phosphor in which the variable w, which is the product of 2 representing the molar ratio of Eu and the variable w, is in the range of 0.001 or more and less than 0.005, the emission intensity increases when irradiated with excitation light. When the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably in the range of 80 μm or more and 250 μm or less, the sintered body has a color tone within region A1 when irradiated with excitation light, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light whose wavelength has been converted by the nitride phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more.

[0043] The sintered body contains the nitride phosphor represented by the formula (I), and in the formula (I), M 2 When M is Eu and 0.003 ≤ w ≤ 0.0045, it is preferable that the thickness is in the range of 100 μm or more and 200 μm or less. The sintered body contains the nitride phosphor represented by the formula (I), and in the formula (I), M 2 When M is Eu and 0.003 ≤ w ≤ 0.0045, it is more preferable that the thickness is in the range of 100 μm or more and 185 μm or less. In the composition represented by the formula (I), the element M which is an activating element 2 When M is Eu and the variable w, which is the product of 2 representing the molar ratio of Eu and the variable w, is in the range of 0.003 or more and less than 0.0045, the emission intensity of the nitride phosphor increases when irradiated with excitation light. When 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 has a color tone within region A1 when irradiated with excitation light, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light whose wavelength has been converted by the nitride phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more.

[0044] The sintered body contains a nitride phosphor having the composition represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.001 ≦ w < 0.0035, it is preferably in the range of 120 μm or more and 250 μm or less in thickness. The sintered body contains a nitride phosphor having the composition represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.001 ≦ w < 0.0035, it is more preferably in the range of 130 μm or more and 240 μm or less, and even more preferably in the range of 135 μm or more and 230 μm or less. In the composition represented by the formula (I), the element M 2 which is an activating element is Eu, and the variable w which is the product of 2 representing the molar ratio of Eu and the variable w is in the range of 0.001 or more and less than 0.0035, and the nitride phosphor may have a low emission intensity when irradiated with excitation light. When the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably in the range of 120 μm or more and 250 μm or less, more preferably in the range of 130 μm or more and 240 μm or less, and even more preferably in the range of 135 μm or more and 230 μm or less, the sintered body has a color tone in the region A1 when irradiated with excitation light, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light whose wavelength is converted by the nitride phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more.

[0045] The sintered body contains the nitride phosphor represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.002 ≦ w ≦ 0.003, it is preferably in the range of 130 μm or more and 183 μm or less in thickness. The sintered body contains the nitride phosphor represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.002 ≦ w ≦ 0.003, it is more preferably in the range of 135 μm or more and 182 μm or less. In the composition represented by the formula (I), the element M 2When the nitride phosphor in which M is Eu and the variable w, which is the product of 2 representing the molar ratio of Eu and the variable w, is in the range of 0.002 or more and 0.0035 or less, there are cases where the emission intensity is low when irradiated with excitation light. When 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, more preferably in the range of 135 μm or more and 182 μm or less, the sintered body has a color tone within region A1 when irradiated with excitation light, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body, which includes the light whose wavelength has been converted by the excitation light with the nitride phosphor contained in the sintered body and the excitation light transmitted through the sintered body, is 0.005 or more.

[0046] The sintered body contains a nitride phosphor having a composition represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.001 ≤ w < 0.0025, it is preferable that the thickness is in the range of 150 μm or more and 250 μm or less. The sintered body contains the nitride phosphor represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.001 ≤ w < 0.0025, it is more preferable that the thickness is in the range of 160 μm or more and 245 μm or less, and even more preferable that the thickness is in the range of 170 μm or more and 240 μm or less. In the composition represented by the formula (I), the element M which is the activating element 2 is Eu, and when the variable w, which is the product of 2 representing the molar ratio of Eu and the variable w, is in the range of 0.001 or more and less than 0.0025, there are cases where the emission intensity is low when irradiated with excitation light. When the sintered body contains only the nitride phosphor, if the thickness of the sintered body is preferably in the range of 150 μm or more and 250 μm or less, more preferably in the range of 160 μm or more and 245 μm or less, and even more preferably in the range of 170 μm or more and 240 μm or less, the sintered body has a color tone within the range of region A1 when irradiated with excitation light, emits light including the light whose wavelength has been converted by the excitation light with the phosphor contained in the sintered body and the excitation light transmitted through the sintered body, and emits light for which the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body is 0.005 or more.

[0047] The sintered body contains a nitride phosphor having the composition represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.001 ≤ w ≤ 0.002, it is preferably in the range of 180 μm or more and 250 μm or less in thickness. The sintered body contains the nitride phosphor represented by the formula (I), and in the formula (I), M 2 is Eu, and when w satisfies 0.001 ≤ w ≤ 0.002, it is more preferably in the range of 181 μm or more and 240 μm or less, and even more preferably in the range of 182 μm or more and 230 μm or less. In the composition represented by the formula (I), the element M 2 which is an activating element is Eu, and the variable w which is the product of 2 representing the molar ratio of Eu and the variable w may have a low emission intensity when irradiated with excitation light. When 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 even more preferably in the range of 182 μm or more and 230 μm or less, the sintered body has a color tone within the range of region A1 when irradiated with excitation light, emits light including the light wavelength-converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body, and emits light having an integrated value ratio Z2 / Z1 of 0.005 or more in the emission spectrum of the light emitted from the sintered body.

[0048] The sintered body is preferably formed by firing phosphor particles having an average particle diameter Db (Fisher Sub-sieve sizer's number) measured by the Fisher Sub-sieve sizer method (hereinafter also referred to as the "FSSS method") of less than 1 μm. When the sintered body is formed by firing phosphor particles having an average particle diameter Db measured by the FSSS method of less than 1 μm, the particle growth of the phosphor particles is likely to be promoted, and the particle size of the phosphor particles that can be confirmed on the fracture surface of the sintered body becomes larger than that of the phosphor particles as the raw material. As a result, the interface in the sintered body composed of phosphor particles decreases, and the sintered body becomes a sintered body through which light easily passes. The phosphor particles as the raw material for forming the sintered body preferably have an average particle diameter Db measured by the FSSS method in the range of 0.01 μm or more and 0.99 μm or less, more preferably in the range of 0.05 μm or more and 0.98 μm or less, still more preferably in the range of 0.10 μm or more and 0.95 μm or less, and may also be in the range of 0.50 μm or more and 0.95 μm or less. The FSSS method is a type of air permeability method, which measures the specific surface area using the flow resistance of air and mainly determines the particle diameter of primary particles.

[0049] The sintered body is preferably formed by firing phosphor particles having a particle size ratio Db / Dm of the average particle size Db measured by the Fisher sub-sieve sizer method to the volume median diameter Dm measured by the laser diffraction particle size distribution measurement method of 0.45 or less. The laser diffraction particle size distribution measurement method is a measurement method that utilizes the scattered light of the laser light irradiated on the particles and distributes the particle size without distinguishing between primary particles and secondary particles. The volume median diameter Dm is the volume median diameter at which the cumulative frequency from the small diameter side in the particle size distribution measured by the laser diffraction particle size distribution measurement method is 50%. The closer the particle size ratio Db / Dm is to a value of 1, the smaller the amount of secondary particles contained, and the larger the proportion of primary particles contained in the powder. When the particle size ratio Db / Dm of the phosphor is 0.45 or less, the proportion of secondary particles contained in the powder increases. When the sintered body is formed by firing 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 likely to increase. As a result, the particle growth of the phosphor particles is likely to be promoted, and a sintered body having a high relative density is obtained. The phosphor particles as a raw material for forming the sintered body may have a particle size ratio Db / Dm of 0.44 or less, 0.43 or less, 0.42 or less, and are preferably 0.30 or more, may be 0.32 or more, or may be 0.35 or more.

[0050] The sintered body is preferably formed by firing phosphor particles having a volume median diameter Dm measured by the laser diffraction particle size distribution measurement method in the range of 0.02 μm or more and 3.5 μm or less, may be in the range of 0.05 μm or more and 3.2 μm or less, or may be in the range of 0.05 μm or more and 3.0 μm or less. When the sintered body is formed by firing phosphor particles having a volume median diameter measured by the laser diffraction particle size distribution measurement method in the range of 0.02 μm or more and 3.5 μm or less, the particle growth of the phosphor particles is likely to be promoted, and the particle size of the phosphor particles that can be confirmed on the fracture surface of the sintered body becomes larger than that of the phosphor particles as the raw material. By reducing the interfaces in the sintered body composed of phosphor particles, the sintered body becomes a sintered body through which light can easily pass. If the phosphor particles as the raw material for forming the sintered body have a volume median diameter Dm in the range of 0.02 μm or more and 3.5 μm, the particle size ratio Db / Dm becomes 0.45 or less, the particle size of the phosphor particles that can be confirmed on the fracture surface of the sintered body becomes larger, the interfaces of the phosphor particles are reduced, and a sintered body with a high relative density can be obtained.

[0051] In the image of the scanning electron microscope (SEM) of the fracture surface of the sintered body, individual phosphor particles constituting the sintered body can be confirmed, and it is preferable that the major axis of the phosphor particles is in the range of 0.1 μm or more and 20 μm or less. If the major axis 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 it can be inferred that the particle growth of the phosphor particles as the raw material is promoted. The major axis of the phosphor particles refers to the longest diameter passing through the inside of the phosphor particle from one end of the contour of the phosphor particle whose contour can be confirmed in the SEM image of the fracture surface of the sintered body to the other end. The sintered body may have a major axis of the phosphor particles that can be confirmed in the SEM image of the fracture surface of the sintered body in the range of 0.15 μm or more and 15 μm or less.

[0052] The method for manufacturing the sintered body preferably includes preparing a phosphor, preparing a molded body containing the phosphor, and firing the molded body to obtain a sintered body.

[0053] The phosphor is prepared by selecting at least one phosphor selected from the group consisting of a nitride phosphor represented by the above formula (I) and an α-sialon phosphor having the composition represented by the above formula (II). The phosphor may be prepared by receiving a transfer from another company, or may be prepared by manufacturing using the following method.

[0054] When the phosphor contains a nitride phosphor represented by the above formula (I), the nitride phosphor includes a first compound containing Ba, and at least one element M 1 selected from the group consisting of Sr, Ca, and Mg, and at least one element M 2 selected from the group consisting of Eu, Ce, Tb, and Mn, a compound containing Si, and Ba, element M 1 element M 2 and Si are mixed so as to satisfy the composition represented by the above formula (I) to obtain a raw material mixture, and this raw material mixture is heat-treated in an atmosphere containing nitrogen at a temperature in the range of 980 °C or higher and 1680 °C or lower. It is preferably obtained. The nitride phosphor may be manufactured with reference to JP-A-2020-083739. The nitride phosphor is preferably phosphor particles having an average particle diameter Db measured by the FSSS method of less than 1 μm. The nitride phosphor is preferably phosphor particles having a particle size ratio Db / Dm of the average particle diameter Db measured by the FSSS method to the volume median diameter Dm measured by the laser diffraction particle size distribution measurement method of 0.45 or less.

[0055] In preparing the molded body, the raw material for forming the molded body includes a nitride phosphor represented by the formula (I) and an α-sialon phosphor having the composition represented by the formula (II). In preparing the molded body, it is preferable that the raw material for forming the molded body consists of a phosphor selected from the group consisting of the nitride phosphor represented by the formula (I) and the α-sialon phosphor represented by the formula (II). In preparing the molded body, it is preferable that the raw material for forming the molded body consists of a nitride phosphor having the composition represented by the formula (I). The content of the nitride phosphor having the composition represented by the 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. The remainder of the content of the nitride phosphor having the composition represented by the formula (I) in the raw material for forming the molded body may be an α-sialon phosphor having the composition represented by the formula (II). The raw material or raw material mixture for forming the molded body preferably does not contain impurities that suppress the particle growth of the phosphor particles serving as the raw material, other than the nitride phosphor represented by the formula (I) and the α-sialon phosphor represented by the formula (II). Here, the impurities that suppress the particle growth of the phosphor particles refer to hydrides, nitrides, carbonates, chlorides, imide compounds, and amide compounds containing elements contained in the nitride phosphor or α-sialon phosphor.

[0056] In preparing a shaped body, a raw material containing at least one phosphor selected from the group consisting of a nitride phosphor and an α-sialon phosphor is shaped into a desired shape to obtain a shaped body. The raw material containing at least one phosphor selected from the group consisting of a nitride phosphor and an α-sialon phosphor is preferably a powder, or may be a slurry containing the powder. As the shaping method of the shaped body, a pressing method of pressing the powder for shaping, or a slurry shaping method of preparing a slurry containing the powder and obtaining a shaped body from the slurry can be adopted. Examples of the pressing method include a die pressing method and a cold isostatic pressing method (CIP) defined in No. 2109 of JIS Z2500:2000. For the shaping method, two methods may be adopted to adjust the shape of the shaped body, and CIP shaping may be performed after die pressing. In CIP shaping, it is preferable to press the shaped body using water as a medium.

[0057] The pressure during die pressing is preferably in the range of 1 MPa or more and 50 MPa or less, more preferably in the range of 2 MPa or more and 20 MPa or less, and even more preferably in the range of 2 MPa or more and 15 MPa or less. If the pressure during die pressing is within the above range, the shaped body can be adjusted to a desired shape.

[0058] The pressure in CIP shaping is preferably in the range of 50 MPa or more and 500 MPa or less, more preferably in the range of 100 MPa or more and 450 MPa or less, and even more preferably in the range of 200 MPa or more and 400 MPa or less. When the pressure in CIP shaping is within the above range, the density (shaping density) of the shaped body can be increased, and a shaped body having a substantially uniform density throughout can be obtained, and in the subsequent firing process, the density of the obtained sintered body can be increased.

[0059] In obtaining a sintered body by firing a formed body, the firing temperature is preferably in the range of 1600°C or higher and 2200°C or lower, more preferably in the range of 1600°C or higher and 2000°C or lower, even more preferably in the range of 1600°C or higher and 1900°C or lower, and still more preferably in the range of 1600°C or higher and 1800°C or lower. When the firing temperature is in the range of 1600°C or higher and 2200°C or lower, a sintered body with a relative density of 97% or higher can be obtained. In this specification, the case of firing an unfired formed body is referred to as firing.

[0060] Firing methods include an atmosphere sintering method in which firing is performed in a non-oxidizing atmosphere without applying pressure or load, an atmosphere pressure sintering method in which firing is performed under pressure in a non-oxidizing atmosphere, a hot press sintering method, and a spark plasma sintering method (SPS).

[0061] Firing is preferably performed in an atmosphere containing nitrogen gas. The atmosphere containing nitrogen gas is preferably an atmosphere containing at least 99% by volume or more of nitrogen. Nitrogen in the atmosphere containing nitrogen gas is preferably 99% by volume or more, more preferably 99.5% by volume or more. In the atmosphere containing nitrogen gas, in addition to nitrogen, a small amount of gas such as oxygen may be contained, but the oxygen content in the atmosphere containing nitrogen gas is preferably 1% by volume or less, more preferably 0.5% by volume or less, even more preferably 0.1% by volume or less, still more preferably 0.01% by volume or less, and particularly preferably 0.001% by volume or less. The atmosphere in the firing process may be an atmosphere containing nitrogen and having a reducing property, or an atmosphere containing nitrogen and hydrogen gas. When hydrogen gas is contained in the nitrogen-containing atmosphere in the firing process, the hydrogen gas content in the atmosphere is preferably 1% by volume or more, more preferably 5% by volume or more, and even more preferably 10% by volume or more. The atmosphere for heat treatment may be a reducing atmosphere using solid carbon in the air atmosphere.

[0062] In obtaining the sintered body, by firing the green body in an atmosphere containing nitrogen gas, a sintered body having a relative density of 97% or more, including a particle size having a composition of a nitride phosphor having high emission intensity, can be obtained. Element M which is an activator of the nitride phosphor 2 When is Eu, divalent Eu which is an activator contributing to emission in the nitride phosphor or α-sialon phosphor 2+ Due to the increase in the proportion occupied, a sintered body having high emission intensity can be obtained. Divalent Eu 2+ Tends to be oxidized to trivalent Eu 3+ However, by subjecting the green body to primary firing in an atmosphere containing nitrogen gas and having a high reducing power, trivalent Eu in the nitride phosphor contained in the green body 3+ Is reduced to divalent Eu 2+ Therefore, the proportion occupied by divalent Eu in the nitride phosphor or α-sialon phosphor increases, and a sintered body containing crystals having a composition of a nitride phosphor or α-sialon phosphor having high emission intensity is obtained. 2+

[0063] The atmospheric pressure of firing is preferably in the range of 0.1 MPa or more and 2.0 MPa or less, more preferably in the range of 0.2 MPa or more and 1.5 MPa or less, and even more preferably in the range of 0.5 MPa or more and 1.2 MPa or less. The atmospheric pressure in the primary firing is preferably gauge pressure. When the atmospheric pressure of firing is within the above range, decomposition of the crystal structure is suppressed, and a sintered body containing at least one phosphor selected from the group consisting of a nitride phosphor and an α-sialon phosphor having high emission intensity is obtained.

[0064] The time for primary firing may be appropriately selected according to the atmospheric pressure. The firing time is, for example, 0.5 hours or more and 20 hours or less, preferably 1 hour or more and 10 hours or less.

[0065] ​The method for manufacturing a sintered body may include processing the sintered body after obtaining the sintered body. In the method for manufacturing a sintered body, processing the sintered body may include cutting the obtained sintered body into a desired size. As the cutting method, a known method can be used, for example, a method using a wire saw or the like. The obtained sintered body emits light of a color tone within region A1 when irradiated with excitation light, and the sintered body may be processed so that the integrated value ratio Z2 / Z1 in the emission spectrum including the light emitted from the sintered body and the excitation light transmitted through the sintered body is 0.005 or more, and the thickness is in the range of 30 μm or more and 300 μm or less so that light is emitted.

[0066] The sintered body may be combined with a light-emitting element such as an LED or an LD to form a light-emitting device. The light-emitting device arranges the sintered body at a position where light is irradiated from an excitation light source such as a light-emitting element, and the light irradiated from the excitation light source is wavelength-changed by the sintered body to emit light having a color tone within region A1.

[0067] The light-emitting device includes an excitation light source that emits light having an emission peak wavelength in the range of 380 nm or more and 570 nm or less, and a sintered body disposed at a position where light is irradiated from the excitation light source. The light-emitting device may be used in combination with another sintered body including a phosphor having a composition different from that of the sintered body and a phosphor selected from the group consisting of a nitride phosphor and an α-sialon phosphor.

[0068] The excitation light source that emits light having an emission peak wavelength in the range of 380 nm or more and 570 nm or less is preferably a light-emitting element. The light-emitting element more preferably has an emission peak wavelength in the range of 400 nm or more and 550 nm or less. The light-emitting element is, for example, a semiconductor light-emitting element using a nitride-based semiconductor (In X Al Y Ga 1-X-Y N, 0≦X, 0≦Y, X + Y≦1) is preferably used. By using a semiconductor light-emitting element as the excitation light source, a stable light-emitting device with high efficiency, high linearity of output with respect to input, and strong resistance to mechanical shock can be obtained.

[0069] Figs. 7 and 8 show a configuration example of a light-emitting device using a sintered body as a wavelength conversion member. Fig. 7 is a schematic plan view of the light-emitting device 100. Fig. 8 is a schematic cross-sectional view taken along line VII-VII' of the light-emitting device 100 shown in Fig. 7. The light-emitting device 100 includes a light-emitting element 10 having an emission peak wavelength within the range of 380 nm or more and 570 nm or less, and a wavelength conversion member 51 that is excited by the light from the light-emitting element 10 to emit light. The light-emitting element 10 is flip-chip mounted on the substrate 1 via, for example, bumps which are conductive members 61. The wavelength conversion member 51 is disposed 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 covering member 90 that reflects light. The light-emitting element 10 can receive power supply from outside the light-emitting device 100 via wirings and conductive members 61 formed on the substrate 1, and cause the light-emitting device 100 to emit light. The light-emitting device 100 may include a semiconductor element 11 such as a protection element for preventing the light-emitting element 10 from being damaged by application of an excessive voltage. The semiconductor element 11 may be mounted on the substrate 1 via the conductive member 61. The covering member 90 is disposed, for example, so as to cover the semiconductor element 11. Hereinafter, each member used in the light-emitting device will be described. For details, reference can also be made to the disclosure of, for example, Japanese Patent Application Laid-Open No. 2014-112635.

[0070] The adhesive layer is preferably made of a material that can optically connect the light-emitting element and the wavelength conversion member. As the material constituting the adhesive layer, for example, at least one resin selected from the group consisting of an epoxy resin, a silicone resin, a phenol resin, and a polyimide resin, or an inorganic material such as silicon oxide or silicon nitride is preferable. Further, the light-emitting element and the wavelength conversion member may be directly joined without an adhesive layer.

[0071] The semiconductor elements provided as required in the light-emitting device include, for example, transistors for controlling the light-emitting element, and protection elements for suppressing the destruction and performance degradation of the light-emitting element due to excessive voltage application. Examples of the protection element include a Zener diode. When the light-emitting device includes a coating member, it is preferable to use an insulating material as the material of the coating member. More specifically, for example, phenolic resin, epoxy resin, bismaleimide triazine resin (BT resin), polyphthalamide (PPA) resin, and silicone resin can be mentioned. A colorant, a phosphor, and a filler may be added to the coating member as required. The light-emitting device may use bumps as the conductive member. As the material of the bumps, Au or its alloy can be used, and as other conductive members, eutectic solder (Au-Sn), Pb-Sn, lead-free solder, etc. can be used.

[0072] An example of the manufacturing method of the light-emitting device will be described. For details, reference can also be made to the disclosures of, for example, Japanese Patent Application Laid-Open No. 2014-112635 or Japanese Patent Application Laid-Open No. 2017-117912. The manufacturing method of the light-emitting device preferably includes a step of arranging the light-emitting element, a step of arranging the semiconductor element as required, a step of preparing the wavelength conversion member, a step of bonding the light-emitting element and the wavelength conversion member, and a step of arranging the coating member.

[0073] For example, in the step of arranging the light-emitting element, the light-emitting element is arranged on the substrate. The light-emitting element and the semiconductor element are, for example, flip-chip mounted on the substrate. Also, in the step of preparing the wavelength conversion member, a wavelength conversion member made of the sintered body obtained by the above manufacturing method is prepared. Next, in the step of bonding the light-emitting element and the wavelength conversion member, the prepared wavelength conversion member is opposed to the light-emitting surface of the light-emitting element, and the wavelength conversion member is joined to the light-emitting element with an adhesive layer. Next, in the step of arranging the coating member, the side surfaces of the light-emitting element and the wavelength conversion member are covered with the coating member. This coating member is for reflecting the light emitted from the light-emitting element, and when the light-emitting device also includes a semiconductor element, it is preferable to arrange the semiconductor element to be embedded in the coating member. In the above manner, the light-emitting device shown in FIGS. 7 and 8 can be manufactured.

Example

[0074] Hereinafter, the present invention will be specifically described by way of examples. The present invention is not limited to these examples.

[0075] Preparation of Nitride Phosphors 1 to 6 Ba 3 N 2 Sr 3 N 2 EuN, Si 3 N 4 Each of these compounds was used as a raw material. Each compound as a raw material was weighed in a glove box under an inert gas atmosphere so that the molar ratio of each element 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 into a crucible, and heat treatment was performed at a gas pressure of 0.9 MPa, 1600 °C for 5 hours in an atmosphere containing 99.9% by volume or more of nitrogen and the balance being oxygen (0.1% by volume or less) to obtain a fired product. Since the particles of the obtained fired product were sintered together, they were dispersed, and then sieving classification was performed to remove coarse particles and fine particles, thereby obtaining nitride phosphor particles 1 to 6 having the charging composition shown in Table 1. The composition of the obtained nitride phosphor particles had the composition represented by formula (I) and had substantially the same composition as the charging composition.

[0076] The following evaluations were performed on the obtained nitride phosphors. The results are shown in Table 5.

[0077] Average Particle Diameter Db For nitride phosphors 1 to 6, the average particle diameter Db was measured by the FSSS method using a Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific).

[0078] Volume Median Diameter Dm For nitride phosphors 1 to 6, the volume median diameter Dm at which the volume cumulative frequency from the small diameter side reached 50% was measured using a laser diffraction particle size distribution measuring device (MASTER SIZER2000, manufactured by MALVERN).

[0079] Chromaticity coordinates (x, y), relative luminance (%), emission peak wavelength, full width at half maximum For Nitride Phosphors 1 to 6, using a spectrofluorophotometer (QE-2000, manufactured by Otsuka Electronics Co., Ltd.), the emission peak wavelength was 450 nm, 1300 mW / mm 2 or more and 6000 mW / mm 2 or less. Specifically, 1300 mW / mm 2 or more and 1500 mW / mm 2 or less. Each nitride phosphor was irradiated with excitation light within this output range, and the emission spectrum of the light emitted from each nitride phosphor at room temperature was measured. From the emission spectrum data measured for each nitride phosphor, the chromaticity coordinates (x, y) in the CIE1931 colorimetric system were determined. From the emission spectrum data of the light emitted from each nitride phosphor measured for each nitride phosphor, taking the luminance of Nitride Phosphor 5 with the smallest molar ratio of the activating element Eu as 100%, the luminances of Examples 1 to 4 and 6 were determined as relative luminances. From the emission spectrum data of the light emitted from each nitride phosphor measured for each nitride phosphor, the emission peak wavelength λp (nm) and the full width at half maximum were determined. In this specification, the full width at half maximum refers to the wavelength width at which the emission intensity becomes 50% of the emission intensity at the emission peak wavelength showing the maximum emission intensity in the emission spectrum.

[0080] True density For Nitride Phosphors 1 to 6, the true density (g / cm 3 ) was determined from the composition of each nitride phosphor.

[0081]

Table 5

[0082] All of Nitride Phosphors 1 to 6 have the composition represented by the above formula (I). All of Nitride Phosphors 1 to 6 have an average particle size Db measured by the FSSS method of less than 1 μm, specifically, within the range of 0.70 μm or more and 0.95 μm or less. Also, all of Nitride Phosphors 1 to 6 have a particle size ratio Db / Dm of 0.45 or less, specifically, within the range of 0.30 or more and 0.41 or less.

[0083] Figure 9 is a SEM photograph of the nitride phosphor 5 observed with a scanning electron microscope (SEM). The nitride phosphor 5 contains many phosphor particles with a particle size of less than 1 μm.

[0084] For each of the sintered bodies in the examples and comparative examples described below, the following measurements were performed, and the results are shown in Tables 6 to 11.

[0085] Relative density (%) The relative density of each sintered body in the examples and comparative examples 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 that is the raw material of each sintered body in the examples and comparative examples.

[0086] Chromaticity coordinates (x, y) Each of the sintered bodies in the examples and comparative examples was mounted on a light-emitting element irradiated with light from a light-emitting element (LED) to form each test light-emitting device. A current of 1 A was passed through the light-emitting element, and the emission peak wavelength was 450 nm, and 1300 mW / mm 2 above m6000W / mm 2 The output was within the following range. Specifically, 1300 mW / mm 2 above 1500 mW / mm 2The sintered body was irradiated with excitation light having an output within the following range, and the light emitted from each test light-emitting device was measured as the emission spectrum of the light emitted from the sintered body including the light whose wavelength was converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body, using a multi-channel spectroscope (PMA-12, Hamamatsu Photonics K.K.). The chromaticity coordinates (x, y) in the CIE1931 color system were determined from the measured emission spectrum. In the emission spectrum of the light emitted from each measured sintered body, the first integral value Z1, which is the integral value of the range of the wavelength width surrounded by the emission spectrum within the wavelength range exceeding 500 nm and equal to or less than 800 nm, was measured with respect to the horizontal axis where the emission intensity (a.u. (arbitrary value)) is 0 (zero). In the emission spectrum of the light emitted from each measured sintered body, the second integral value Z2, which is the integral value of the range of the wavelength width surrounded by the emission spectrum of the light emitted from the sintered body within the wavelength range of 400 nm or more and 500 nm or less, was measured with respect to the horizontal axis where the emission intensity (a.u. (arbitrary value)) is 0 (zero). The integral value ratio Z2 / Z1 of the second integral value Z2 to the first integral value Z1 was determined. In the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates of each test light-emitting device were described, and it was confirmed whether they were within or outside the ranges of region A1, region A2, and region A3. When the light emitted from each test light-emitting device had a color tone within the range of any of the regions, it was described as "IN", and when the light emitted from each test light-emitting device had a color tone outside the range of any of the regions, it was described as "OUT".

[0087] Relative luminous flux (%) In each test light-emitting device of the examples and comparative examples, a current of 1 A was passed through the light-emitting element, the emission peak wavelength was 450 nm, and the output was within the following range, specifically, 1300 mW / mm 2 or more and 6000 mW / mm 2 or less. Specifically, excitation light having an output within the range of 1300 mW / mm 2 or more and 1500 mW / mm 2 or less was irradiated onto the sintered body, and the luminous flux (lm) of the light emitted from each light-emitting device was measured using a total luminous flux measuring device. Among the examples using the same nitride phosphor, taking the lowest luminous flux as 100%, the luminous flux of the light emitted from each light-emitting device was determined as the relative luminous flux (%).

[0088] Examples 1-1 to 1-3 The nitride phosphor 1 was filled into a mold, and a cylindrical compact with a diameter of 28.5 mm and a thickness of 10 mm was press-formed at a pressure of 2 MPa. Further, CIP forming was performed at a pressure of 352.8 MPa to form a cylindrical compact with a diameter of 25 mm and a thickness of 9 mm. The compact consists only of the above-mentioned nitride phosphor, and the nitride phosphor is 100% by mass.

[0089] To obtain a sintered body The obtained compact was placed in a firing furnace (manufactured by Fuji Denpa Kogyo Co., Ltd.), and held at 1675 °C and 0.9 MPa for 1 hour in an atmosphere containing 99.9% by volume or more of nitrogen and the balance being oxygen (0.1% by volume or less) to perform firing and obtain a sintered body.

[0090] Light-emitting device for testing Each sintered body was made to have the thickness shown in Table 6 to obtain each sintered body according to Examples 1-1 to 1-3. Each sintered body was placed on the side irradiated with the light of a light-emitting element (LED) that irradiates excitation light with an output within the range of 1300 mW / mm 2 or more and 6000 mW / mm 2 or less, specifically, within the range of 1300 mW / mm 2 or more and 1500 mW / mm 2 or less to form a light-emitting device for testing. For each light-emitting device according to Examples 1-1 to 1-3, the above-mentioned measurement was performed. The results are shown in Table 6.

[0091]

Table 6

[0092] Each light-emitting device using each sintered body according to Examples 1-1 to 1-3 has a color tone within region A1 when irradiated with excitation light, and emits light with an integrated value ratio Z2 / Z1 of 0.005 or more in the emission spectrum of the light emitted from the sintered body, which includes the light whose wavelength is converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body. The excitation light having a shorter wavelength than the light whose wavelength is converted by the phosphor contained in the sintered body escapes from the sintered body. Each light-emitting device according to Examples 1-1 to 1-3 has an amber color tone on the shorter wavelength side within region A1 and emits light with a high relative luminous flux.

[0093] FIG. 10 shows regions A1, A2, and A3 and the chromaticity coordinates (x, y) of the light emission of each light-emitting device using each sintered body according to Examples 1-1 to 1-3 in the chromaticity diagram of the CIE1931 color system. As shown in FIG. 10, each light-emitting device using each sintered body according to Examples 1-1 to 1-3 emits light having an amber color tone within region A2 on the shorter wavelength side within the range of region A1.

[0094] Each sintered body used in each light-emitting device according to Examples 1-1 to 1-3 contains a nitride phosphor having a composition represented by the formula (I), and in the formula (I), M 2 is Eu, w satisfies 0.001 ≦ w < 0.05, and more specifically satisfies 0.005 ≦ w ≦ 0.01. Since the molar ratio of Eu as the activating element is large, the emission intensity becomes high when irradiated with excitation light, and it is a sintered body with a thickness in the range of 50 μm or more and 120 μm or less. Each light-emitting device according to Examples 1-1 to 1-3 has a color tone within region A1 even when using a sintered body with a small thickness, and emits light with an integrated value ratio Z2 / Z1 of 0.005 or more in the emission spectrum of the light emitted from the sintered body, which includes the light whose wavelength is converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body.

[0095] Examples 2-1 to 2-5 and Comparative Example 2-6 Except for using the nitride phosphor 2, each sintered body was obtained in the same manner as in Examples 1-1 to 1-3, and each sintered body according to Examples 2-1 to 2-5 and Comparative Example 2-6 was obtained so as to have the thickness shown in Table 7. Each sintered body was placed on the side irradiated with the light of a light-emitting element (LED) that irradiates excitation light with an output within the range of 450 nm for the emission peak wavelength and 6000 mW / mm 2 or more and 1300 mW / mm 2 or less, specifically 1300 mW / mm 2 or more and 1500 mW / mm 2 or less, and each light-emitting device for testing was obtained. For each light-emitting device according to Examples 2-1 to 2-5 and the light-emitting device according to Comparative Example 2-6, the above-described measurement was performed. The results are shown in Table 7.

[0096]

Table 7

[0097] Each light-emitting device using each sintered body according to Examples 2-1 to 2-5 has a color tone within region A1 when irradiated with excitation light, and light is emitted with an integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light whose wavelength has been converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body being 0.005 or more, and the excitation light having a shorter wavelength than the light wavelength-converted by the sintered body escapes from the sintered body. Each light-emitting device according to Examples 2-1 to 2-5 has an amber color tone on the short-wavelength side within region A1, and light with a high relative luminous flux is emitted.

[0098] The light-emitting device using the sintered body according to Comparative Example 2-6 has a color tone within the range of region A1 when irradiated with excitation light, but the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light whose wavelength has been converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is less than 0.005, and the proportion of the excitation light having a shorter wavelength than the light whose wavelength has been changed by the phosphor contained in the sintered body escaping from the sintered body is small, and light with a low relative luminous flux is emitted.

[0099] FIG. 11 is a diagram showing the chromaticity coordinates (x, y) of the light emission of each light-emitting device using each sintered body according to Examples 2-1 to 2-5 and the light-emitting device using the sintered body according to Comparative Example 2-6, in the chromaticity diagram of the CIE1931 color system. As shown in FIG. 11, each light-emitting device using each sintered body according to Examples 2-1 to 2-5 emits light having an amber color tone within the range of A3 on the shorter wavelength side even within region A1.

[0100] As shown in FIG. 11, the light-emitting device using the sintered body according to Comparative Example 2-6 emits light having a color tone outside the ranges of region A2 and region A3 although it is within region A1.

[0101] Each sintered body used in each light-emitting device according to Examples 2-1 to 2-5 contains a nitride phosphor having a composition represented by the formula (I), and in the formula (I), M 2 is Eu, w satisfies 0.001 ≦ w < 0.0035, more specifically 0.002 ≦ w ≦ 0.003, and the thickness of the sintered body is in the range of 130 μm or more and 183 μm or less. In the light-emitting devices according to Examples 2-1 to 2-5 using these sintered bodies, the excitation light having a shorter wavelength than the light wavelength-converted by the phosphor contained in the sintered body escapes from the sintered body, and the integral value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light wavelength-converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more, and light with a relatively high luminous flux is emitted.

[0102] The sintered body used in the light-emitting device according to Comparative Example 2-6 contains a nitride phosphor having a composition represented by the formula (I), and in the formula (I), M 2is Eu, w satisfies 0.001 ≦ w < 0.0035, more specifically 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. Since the light-emitting device according to Comparative Example 2-6 includes a sintered body having a thickness exceeding 183 μm, the excitation light escaping from the sintered body is small, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light whose wavelength is converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is less than 0.005, and light with a low relative luminous flux is emitted.

[0103] Examples 3-1 to 3-3 Except for using the nitride phosphor 3, each sintered body was obtained in the same manner as in Examples 1-1 to 1-3, and each sintered body according to Examples 3-1 to 3-3 was obtained so as to have the thickness shown in Table 8. Each sintered body was placed on the side irradiated with the light of a light-emitting element (LED) having an output of excitation light in the range of 450 nm for the emission peak wavelength and 1300 mW / mm 2 or more and 6000 mW / mm 2 or less, specifically 1300 mW / mm 2 or more and 1500 mW / mm 2 or less, and each light-emitting device for testing was formed. For each light-emitting device according to Examples 3-1 to 3-5, the above-described measurement was performed. The results are shown in Table 8.

[0104]

Table 8

[0105] Each light-emitting device using each sintered body according to Examples 3-1 to 3-3 has a color tone within the range of Region A1, and emits light with an integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light whose wavelength is converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body of 0.005 or more, and the excitation light having a shorter wavelength than the light whose wavelength is converted by the phosphor contained in the sintered body escapes from the sintered body. Each light-emitting device according to Examples 3-1 to 3-3 has an amber color tone on the short-wavelength side within Region A1, and emits light with a high relative luminous flux.

[0106] FIG. 12 is a diagram showing regions A1, A2, and A3 and the chromaticity coordinates (x, y) of the light emission of each light-emitting device using each sintered body according to Examples 3-1 to 3-3 in the chromaticity diagram of the CIE1931 color system. As shown in FIG. 12, each light-emitting device using each sintered body according to Example 3-1 to Example 3-3 emits light having an amber color tone in region A2, which is a region to the left of the second straight line connecting the second a' point (x = 0.557, y = 0.433) and the third a' point (x = 0.582, y = 0.409) within the range of region A1 in the chromaticity diagram of the CIE color system.

[0107] Each sintered body used in each light-emitting device according to Example 3-1 to Example 3-3 contains a nitride phosphor having a composition represented by the following formula (I). In the following formula (I), M 2 is Eu, w satisfies 0.001 ≦ w < 0.005, more specifically, 0.003 ≦ w ≦ 0.0045, the thickness of the sintered body is in the range of 80 μm or more and 200 μm or less, and more specifically, the thickness of the sintered body is in the range of 100 μm or more and 200 μm or less. Each light-emitting device according to Example 3-1 to Example 3-3 using these sintered bodies emits light having a relatively high luminous flux, where the integral value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body, which includes the light whose excitation light with a shorter wavelength than the light wavelength-converted by the phosphor contained in the sintered body escapes from the sintered body and the light whose excitation light is wavelength-converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body, is 0.005 or more.

[0108] Examples 4-1 to 4-3 and Comparative Examples 4-4 to 4-5 Each sintered body was obtained in the same manner as in Examples 1-1 to 1-3 except that nitride phosphor 4 was used, and each sintered body according to Examples 4-1 to 4-3 and Comparative Examples 4-4 to 4-5 was obtained so as to have the thickness shown in Table 9. Each sintered body has an emission peak wavelength of 450 nm and is in the range of 1300 mW / mm 2 or more and 6000 mW / mm 2 or less, and specifically, 1300 mW / mm 2 or more and 1500 mW / mm 2Place them on the side irradiated with the light of a light-emitting element (LED) that irradiates excitation light within the following range, and use them as each light-emitting device for testing. For each light-emitting device according to Examples 4-1 to 4-3 and each light-emitting device according to Comparative Examples 4-4 to 4-5, perform the above-described measurement. The results are shown in Table 9.

[0109]

Table 9

[0110] Each light-emitting device using each sintered body according to Examples 4-1 to 4-3 has a color tone within region A1, and emits light with an integrated value ratio Z2 / Z1 of 0.005 or more in the emission spectrum of the light emitted from the sintered body including the light whose excitation light is wavelength-converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body, and the excitation light having a shorter wavelength than the light wavelength-converted by the sintered body leaks out from the sintered body. Each light-emitting device according to Examples 4-1 to 4-3 has an amber color tone on the short-wavelength side within region A1 and emits light with a high relative luminous flux.

[0111] Each light-emitting device using each sintered body according to Comparative Examples 4-4 and 4-5 has a color tone within region A1, but the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light whose excitation light is wavelength-converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is less than 0.005, and the ratio of the excitation light having a shorter wavelength than the light whose wavelength is changed by the sintered body leaking out from the sintered body is small, and light with a low relative luminous flux is emitted.

[0112] FIG. 13 is a diagram showing the chromaticity coordinates (x, y) of the light emission of region A1, A2, and A3 and each light-emitting device according to Examples 4-1 to 4-3 and each light-emitting device according to Comparative Examples 4-4 to 4-5 in the chromaticity diagram of the CIE1931 color system. As shown in FIG. 13, each light-emitting device using each sintered body according to Examples 4-1 to 4-3 emits light having an amber color tone within the range of A3 on the even shorter wavelength side within region A1.

[0113] As shown in FIG. 13, each light-emitting device using each sintered body according to Comparative Example 4-4 and Comparative Example 4-5 emits light having a color tone within region A1 but outside the ranges of region A2 and region A3.

[0114] Each sintered body used in each light-emitting device according to Examples 4-1 to 4-3 contains a nitride phosphor having a composition represented by the following formula (I). In the following formula (I), M 2 is Eu, w satisfies 0.001 ≦ w < 0.0035, more specifically 0.002 ≦ w ≦ 0.003, and the thickness of the sintered body is in the range of 130 μm or more and 183 μm or less. Each light-emitting device according to Examples 4-1 to 4-3 using these sintered bodies has excitation light having a shorter wavelength than the light wavelength-converted by the phosphor contained in the sintered body escaping from the sintered body, and the excitation light is wavelength-converted by the phosphor contained in the sintered body. The integrated value ratio Z2 / Z1 in the emission spectrum of the sintered body including the converted light and the excitation light transmitted through the sintered body is 0.005 or more, and light with a high relative luminous flux is emitted.

[0115] Each sintered body used in each light-emitting device according to Comparative Example 4-4 and Comparative Example 4-5 contains a nitride phosphor having a composition represented by the following formula (I). In the following formula (I), M 2 is Eu, w satisfies 0.002 ≦ w < 0.0035, more specifically 0.002 ≦ w ≦ 0.003, but the thickness of the sintered body becomes thicker exceeding 183 μm. Since the light-emitting devices according to Comparative Example 4-4 and Comparative Example 4-5 are provided with a sintered body having a thickness exceeding 183 μm, the excitation light escaping from the sintered body is small, and the excitation light is wavelength-converted by the phosphor contained in the sintered body. The integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the converted light and the excitation light transmitted through the sintered body is less than 0.005, and light with a low relative luminous flux is emitted.

[0116] Examples 5-1 to 5-4 Except for using nitride phosphor 5, each sintered body was obtained in the same manner as in Examples 1-1 to 1-3, and each sintered body according to Examples 5-1 to 5-4 was obtained so as to have the thickness shown in Table 10. Each sintered body has an emission peak wavelength of 450 nm and 1300 mW / mm2 6000 mW / mm or less 2 within the following range, specifically 1300 mW / mm or more 2 1500 mW / mm or less 2 Arrange on the side irradiated with the excitation light of the output that is within the following range, specifically within the range of 1300 mW / mm or more and 1500 mW / mm or less, and use each as a light-emitting device for testing. For each light-emitting device according to Examples 5-1 to 5-4, perform the above-described measurement. The results are shown in Table 10.

[0117]

Table 10

[0118] Each light-emitting device using each sintered body according to Examples 5-1 to 5-4 has a color tone within Region A1, and emits light in which the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light whose excitation light is wavelength-converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more, and the excitation light having a shorter wavelength than the light wavelength-converted by the phosphor contained in the sintered body escapes from the sintered body. Each light-emitting device according to Examples 5-1 to 5-4 emits light having an amber color tone on the shorter wavelength side within Region A1, and emits light having a high relative luminous flux.

[0119] FIG. 14 is a diagram showing Regions A1, A2, and A3 and the emission chromaticity coordinates (x, y) of each light-emitting device using each sintered body according to Examples 5-1 to 5-4 in the chromaticity diagram of the CIE1931 color system. As shown in FIG. 14, each light-emitting device according to Examples 5-1 to 5-4 emits light having an amber color tone within the range of A3 on the even shorter wavelength side within Region A1.

[0120] Each sintered body used in each light-emitting device according to Examples 5-1 to 5-4 contains a nitride phosphor having a composition represented by the above formula (I), and in the above formula (I), M 2is Eu, w satisfies 0.001 ≦ w < 0.0025, more specifically, satisfies 0.001 ≦ w ≦ 0.002, the thickness of the sintered body is within the range of 150 μm or more and 250 μm or less, and more specifically, the thickness of the sintered body is within the range of 180 μm or more and 250 μm or less. In each light-emitting device according to Examples 5-1 to 5-4 using these sintered bodies, excitation light having a shorter wavelength than the light wavelength-converted by the phosphor contained in the sintered body escapes from the sintered body, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body containing the light wavelength-converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more, and light with a high relative luminous flux is emitted.

[0121] FIG. 15 is a SEM photograph of a fracture surface of the sintered body used in the light-emitting device according to Example 5-1. As shown in FIG. 15, individual phosphor particles can be confirmed on the fracture surface of the sintered body used in the light-emitting device according to Example 5-1, and it can be confirmed that the major axis of the phosphor particles is within the range of 0.1 μm or more and 20 μm or less. In the SEM photograph of the fracture surface of the sintered body used in the light-emitting device according to Example 5-1, the major axis of the phosphor particles, which is the longest diameter passing through the inside of the phosphor particles from one end of the contour of the phosphor particles whose contour can be confirmed to the other end, is about 10 μm at the largest. From the photograph shown in FIG. 15, the phosphor particles in the sintered body are larger than the phosphor particles as raw materials, and the particle growth of the phosphor particles is promoted.

[0122] Examples 6-1 to 6-4 Except for using the nitride phosphor 6, each sintered body was obtained in the same manner as in Examples 1-1 to 1-3, and each sintered body according to Examples 6-1 to 6-4 was obtained so as to have the thickness shown in Table 11. Each sintered body has an emission peak wavelength of 450 nm and is 1300 mW / mm 2 or more and 6000 mW / mm 2 or less, and specifically, 1300 mW / mm 2 or more and 1500 mW / mm 2Arrange on the side where the light of the light-emitting element (LED) that irradiates the excitation light within the following range is irradiated to form each light-emitting device for testing. For each light-emitting device for testing according to Examples 6-1 to 6-4, perform the above-described measurement. The results are shown in Table 11.

[0123]

Table 11

[0124] Each light-emitting device using each sintered body according to Examples 6-1 to 6-4 emits light having a color tone within the range of region A1, and the integrated value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light wavelength-converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more, and the excitation light having a shorter wavelength than the light wavelength-converted by the phosphor contained in the sintered body leaks out from the sintered body. Each light-emitting device according to Examples 6-1 to 6-4 emits light having an amber color tone on the shorter wavelength side within region A1 and having a high relative luminous flux.

[0125] FIG. 16 is a diagram showing regions A1, A2, and A3 and the emission chromaticity coordinates (x, y) of each light-emitting device using each sintered body according to Examples 6-1 to 6-4 in the chromaticity diagram of the CIE1931 color system. As shown in FIG. 16, each light-emitting device according to Examples 6-1 to 6-4 emits light having an amber color tone within the range of A3 on the even shorter wavelength side within region A1.

[0126] Each sintered body used in the light-emitting device according to Examples 6-1 to 6-4 contains a nitride phosphor having a composition represented by the formula (I), and in the formula (I), M 2is Eu, w satisfies 0.001 ≦ w < 0.005, more specifically 0.003 ≦ w ≦ 0.0045, the thickness of the sintered body is in the range of 80 μm or more and 250 μm or less, and more specifically, the thickness of the sintered body is in the range of 100 μm or more and 200 μm or less. In each light-emitting device according to Examples 6-1 to 6-4 using these sintered bodies, excitation light having a shorter wavelength than the light wavelength-converted by the phosphor contained in the sintered body escapes from the sintered body, and the integral value ratio Z2 / Z1 in the emission spectrum of the light emitted from the sintered body including the light wavelength-converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more, and light with a high relative luminous flux is emitted.

[0127] Embodiments according to the present disclosure include the following method for manufacturing a sintered body. [Item 1] A sintered body containing at least one phosphor selected from the group consisting of 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), When irradiated with excitation light, in the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) have a color tone within the region A1 defined by a first straight line connecting the first a point (x = 0.549, y = 0.425), a second straight line connecting the second a point (x = 0.562, y = 0.438), a third straight line connecting the third a point (x = 0.589, y = 0.411), a fourth straight line connecting the fourth a point (x = 0.576, y = 0.407), and a fourth straight line connecting the fourth a point and the first a point. The emission peak wavelength is 450 nm, and 1300 mW / mm 2 or more and 6000 mW / mm 2 When irradiated with excitation light having an output within the following range, the integral value ratio Z2 / Z1 of the second integral value Z2 in the wavelength range of 400 nm or more and 500 nm or less to the first integral value Z1 in the wavelength range of more than 500 nm and 800 nm or less in the emission spectrum of the light emitted from the sintered body including the light wavelength-converted by the phosphor contained in the sintered body and the excitation light transmitted through the sintered body is 0.005 or more, and light is emitted. (Ba 1-u-w M 1 u M 2 w ) 2 Si 5 N 8 (I) (In the formula (I), M 1 is at least one element selected from the group consisting of Sr, Ca, and Mg, and M 2 is at least one element selected from the group consisting of Eu, Ce, Tb, and Mn, and u and w satisfy 0 < u ≤ 0.5 and 0.001 ≤ w < 0.5, respectively.) M 3 q Si 12-(r+s) Al r+s O s N 16-s :Eu t (II) (In the formula (II), M3 is at least one element selected from the group consisting of Li, Mg, Ca, Sr, Y, and lanthanoid elements (excluding La and Ce), and q, r, s, and t satisfy 0 < q ≤ 2.0, 2.0 ≤ r ≤ 6.0, 0 ≤ s ≤ 1.0, and 0.001 ≤ t ≤ 0.5, respectively.) [Item 2] The sintered body according to Item 1, wherein the integral value ratio Z2 / Z1 is 0.008 or more. [Item 3] The sintered body according to Item 1 or 2, wherein the integral value ratio Z2 / Z1 is in the range of 0.01 or more and 0.04 or less. [Item 4] The sintered body according to any one of Items 1 to 3, wherein the sintered body is obtained by firing phosphor particles having an average particle diameter Db measured by the Fischer sub-sieve sizer method of less than 1 μm. [Item 5] The sintered body according to any one of Items 1 to 4, wherein the sintered body is obtained by firing phosphor particles having a particle size ratio Db / Dm of the average particle diameter Db measured by the Fischer sub-sieve sizer method to the volume median diameter Dm measured by the laser diffraction particle size distribution measurement method of 0.45 or less. [Item 6] The sintered body according to any one of items 1 to 5, having a relative density of 97% or more. [Item 7] The sintered body according to any one of items 1 to 6, having a thickness within the range of 30 μm or more and 300 μm or less. [Item 8] When irradiated with excitation light, in the region A1, in the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) are such that (x = 0.549, y = 0.425) is the first a point, (x = 0.557, y = 0.433) is the second a' point, (x = 0.582, y = 0.409) is the third a' point, (x = 0.576, y = 0.407) is the fourth a point, and light having a color tone within the region A2 defined by the first' straight line connecting the first a and the second a' points, the second' straight line connecting the second a' and the third a' points, the third' straight line connecting the third a' and the fourth a points, and the fourth straight line connecting the fourth a and the first a points is emitted. The sintered body according to any one of items 1 to 7. [Item 9] When irradiated with excitation light, in the region A1, in the chromaticity diagram of the CIE1931 color system, the chromaticity coordinates (x, y) are such that (x = 0.549, y = 0.425) is the first a point, (x = 0.557, y = 0.433) is the second a' point, (x = 0.579, y = 0.412) is the third a'' point, (x = 0.569, y = 0.412) is the fourth a'' point, and light having a color tone within the region A3 defined by the first'' straight line connecting the first a and the second a' points, the second'' straight line connecting the second a' and the third a'' points, the third'' straight line connecting the third a'' and the fourth a'' points, and the fourth'' straight line connecting the fourth a'' and the first a points is emitted. The sintered body according to any one of items 1 to 8. [Item 10] having a thickness within the range of 50 μm or more and 250 μm or less, containing a first nitride phosphor having the composition represented by the formula (I), In the formula (I), M 2 is Eu, and w satisfies 0.001 ≤ w < 0.01. The sintered body according to any one of items 1 to 9. [Item 11] having a thickness within the range of 80 μm or more and 250 μm or less, comprising 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, the sintered body according to any one of items 1 to 9. [Item 12] The thickness is in the range of 100 μm or more and 200 μm or less, comprising 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, the sintered body according to any one of items 1 to 9. [Item 13] The thickness is in the range of 120 μm or more and 250 μm or less, comprising 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, the sintered body according to any one of items 1 to 9. [Item 14] The thickness is in the range of 130 μm or more and 183 μm or less, comprising 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, the sintered body according to any one of items 1 to 9. [Item 15] The thickness is in the range of 150 μm or more and 250 μm or less, comprising 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, the sintered body according to any one of items 1 to 9. [Item 16] The thickness is in the range of 180 μm or more and 250 μm or less, comprising a first nitride phosphor having a composition represented by the formula (I), In the formula (I), M 2The sintered body according to any one of items 1 to 9, wherein Eu is Eu and w satisfies 0.001 ≤ w ≤ 0.002. [Item 17] comprising a first nitride phosphor having the composition represented by the formula (I), The sintered body according to any one of claims 1 to 16, wherein in the formula (I), u satisfies 0.25 ≤ u ≤ 0.45. [Item 18] An illuminating device comprising an excitation light source that emits light having an emission peak wavelength in the range of 380 nm or more and 570 nm or less, and the sintered body according to any one of claims 1 to 17, disposed at a position irradiated with light from the excitation light source.

Industrial Applicability

[0128] The sintered body of the present disclosure can be used as a wavelength conversion member capable of converting the wavelength of light emitted from an LED or an LD. The illuminating device using the sintered body can be used as a light source for in-vehicle use, general lighting, a backlight of a liquid crystal display device, illumination, a projector, and the like. Further, the sintered body used in the illuminating device emits light by irradiation with excitation light and can also be used as a material for a solid scintillator.

Explanation of Signs

[0129] 1: Substrate, 10: Light emitting element, 11: Semiconductor element, 51: Wavelength conversion member, 61: Conductive member, 80: Adhesive layer, 90: Coating member, 100: Illuminating device.

Claims

1. A sintered body containing at least one phosphor selected from the group consisting of 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), When irradiated with excitation light, the color tone falls within an area A1 defined by a first line connecting the first a point and the second a point, a second line connecting the second a point and the third a point, a third line connecting the third a point and the fourth a point, and a fourth line connecting the fourth a point and the first a point, the chromaticity coordinates (x, y) of which 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 in a chromaticity diagram of the CIE 1931 color system, The emission peak wavelength is 450 nm and the light output is 1300 mW / mm ２ More than 6000mW / mm ２ The sintered body emits light having an integral ratio Z2 / Z1 of 0.005 or more of a second integral value Z2 in a wavelength range of 400 nm or more and 500 nm or less to a first integral value Z1 in a wavelength range of more than 500 nm and 800 nm or less in an emission spectrum of light emitted from the sintered body, the light including the excitation light wavelength-converted by the phosphor contained in the sintered body when irradiated with excitation light having an output within the following range. (BL １－ｕ－ｗ M １ ｕ M ２ ｗ ) ２ Si ５ N ８ (I) (In the formula (I), M １ is at least one element selected from the group consisting of Sr, Ca and Mg, and M ２ is at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and u and w satisfy 0<u≦0.5 and 0.001≦w<0.5, respectively. M ３ ｑ Yes １２－（ｒ＋ｓ） Al ｒ＋ｓ O ｓ N １６－ｓ :Eu ｔ (II) (In the formula (II), M3 is at least one element selected from the group consisting of Li, Mg, Ca, Sr, Y, and lanthanoid elements (excluding La and Ce), and q, r, s, and t each satisfy 0<q≦2.0, 2.0≦r≦6.0, 0≦s≦1.0, and 0.001≦t≦0.5.)

2. The sintered body according to claim 1 , wherein the integral value ratio Z2 / Z1 is 0.008 or more.

3. The sintered body according to claim 1 , wherein the integral value ratio Z2 / Z1 is within a range of 0.01 or more and 0.04 or less.

4. The sintered body according to claim 1 , which is obtained by firing phosphor particles having an average particle size Db of less than 1 μm as measured by a Fisher subsieve sizer method.

5. The sintered body according to claim 1, which is obtained by firing phosphor particles having a particle size ratio Db / Dm of 0.45 or less, where Db is the volume median diameter Dm measured by a laser diffraction particle size distribution measurement method and Db is the average particle size Db measured by a Fisher subsieve sizer method.

6. 2. The sintered body according to claim 1, having a relative density of 97% or more.

7. 2. The sintered body according to claim 1, having a thickness in the range of 30 μm to 300 μm.

8. When irradiated with excitation light, in the chromaticity diagram of the CIE 1931 color system, the chromaticity coordinates (x, y) are (x = 0.549, y = 425) as the 1a point, (x = 0.557, y = 0.433) as the 2a' point, (x = 0.582, y = 0.409) as the 3a' point, and (x = 0.576, y = 0.407) as the 4a point, and the 1a and the 2a' points are connected by a first' straight line, a second' straight line, a third' straight line, a fourth straight line, and a fourth straight line connecting the 4a point and the 1a point. The sintered body according to claim 1, wherein light having a color tone within the region A2 is emitted.

9. When irradiated with excitation light, in the region A1, in a chromaticity diagram of the CIE 1931 color system, 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'', and light having a color tone within a region A3 defined by a first'' line connecting the first a and second a' points, a second'' line connecting the second a' and third a'' points, a third'' line connecting the third a'' and fourth a'' points, and a fourth'' line connecting the fourth a'' and first a points is emitted. The sintered body according to claim 1.

10. The thickness is within the range of 50 μm or more and 250 μm or less, A first nitride phosphor having a composition represented by formula (I), In the formula (I), M ２ The sintered body according to claim 1 , wherein is Eu and w satisfies 0.001≦w<0.

01.

11. The thickness is within the range of 80 μm or more and 250 μm or less, A first nitride phosphor having a composition represented by formula (I), In the formula (I), M ２ The sintered body according to claim 1 , wherein is Eu and w satisfies 0.001≦w<0.

005.

12. The thickness is within the range of 100 μm or more and 200 μm or less, A first nitride phosphor having a composition represented by formula (I), In the formula (I), M ２ The sintered body according to claim 1 , wherein is Eu and w satisfies 0.003≦w≦0.0045.

13. The thickness is within the range of 120 μm or more and 250 μm or less, A first nitride phosphor having a composition represented by formula (I), In the formula (I), M ２ The sintered body according to claim 1 , wherein is Eu and w satisfies 0.001≦w<0.0035.

14. The thickness is within the range of 130 μm or more and 183 μm or less, A first nitride phosphor having a composition represented by formula (I), In the formula (I), M ２ The sintered body according to claim 1 , wherein is Eu and w satisfies 0.002≦w≦0.

003.

15. The thickness is within the range of 150 μm or more and 250 μm or less, A first nitride phosphor having a composition represented by formula (I), In the formula (I), M ２ The sintered body according to claim 1 , wherein is Eu and w satisfies 0.001≦w<0.0025.

16. The thickness is within the range of 180 μm or more and 250 μm or less, A first nitride phosphor having a composition represented by formula (I), In the formula (I), M ２ The sintered body according to claim 1 , wherein is Eu and w satisfies 0.001≦w≦0.

002.

17. A first nitride phosphor having a composition represented by formula (I), The sintered body according to claim 10 to 16, wherein in the formula (I), u satisfies 0.25≦u≦0.

45.

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

Images