JP5245222B2 - Phosphor and light emitting device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high luminance, orange to red light emission phosphor having high luminous efficiency, a high efficient light emitting device having high color rendering properties with the use of this high luminous efficiency phosphor, a lighting unit using this light emitting device, and an image display device. <P>SOLUTION: The phosphor has a chemical composition represented by formula [1]: M<SP>1</SP><SB>3-x-y</SB>Ba<SB>x</SB>M<SP>2</SP><SB>y</SB>M<SP>3</SP><SB>a</SB>M<SP>6</SP><SB>d</SB>(wherein M<SP>1</SP>is at least one element selected from the group consisting of alkaline earth metal elements excluding Ba and Zn; M<SP>2</SP>is at least one activating element selected from the group consisting of Eu, Ce, Cr, Mn, Sm, Tm, Tb, Er, and Yb; M<SP>3</SP>is a tetravalent element including at least Si; M<SP>6</SP>is at least one element selected from the group consisting of N, O, and S; and x, y, a, and d are numbers which meet 0&lt;x&lt;3, 0&lt;y&lt;1, 0&lt;3-x-y, 0.5&le;a&le;1.5, and 4.5&le;d&le;5.5, respectively). <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a phosphor, a phosphor-containing composition and a light emitting device using the phosphor, and an image display device and an illumination device using the light emitting device. More specifically, the present invention relates to a phosphor that emits orange to red light, a phosphor-containing composition and a light emitting device using the phosphor, and an image display device and an illumination device using the light emitting device.

As a conventional technique related to a light emitting device having an excitation light source and a phosphor that converts the wavelength of at least part of light from the excitation light source, a white light emitting device that combines a blue light emitting diode and a yellow phosphor is used for various illumination applications. It has been put into practical use. Representative examples thereof include those described in Patent Document 1, Patent Document 2, Patent Document 3, and the like. In these white light emitting devices, phosphors that are particularly often used are yttrium, aluminum, activated by cerium, represented by the general formula (Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce ³⁺ Garnet phosphor.

  However, the white light emitting device combining the blue light emitting diode and the yttrium / aluminum / garnet phosphor has a problem that the emission color is pale and the color rendering is low because the red component is insufficient for the light emission.

  Against this background, development of a white light emitting device in which a red component that is insufficient for light emission by the white light emitting device using the yttrium, aluminum, and garnet phosphor is supplemented with another red phosphor has been studied. Such a light emitting device is disclosed in Patent Document 4 and the like. However, in the light emitting device described in Patent Document 4 and the like, there are still problems to be improved regarding color rendering, and a light emitting device that solves the problem has been demanded. Note that the red phosphor described in Patent Document 4 contains cadmium and has a problem in terms of environmental pollution.

In Patent Document 5, the general formula M _x (SiO _n ) _y activated by europium or cerium (where M is an alkaline earth metal element and represents Mg, Ca, Sr, Ba, and Ra). The phosphors shown are disclosed. However, here, as a specific example, it is only disclosed that Ba ₃ SiO ₅ : Eu ²⁺ has an emission peak at a wavelength of 590 nm. Further, (Ba _1-a Sr _a ) ₃ SiO ₅ : Eu ²⁺ is also exemplified, but there is no description about specific numerical values of a.

Non-Patent Document 1 discloses a crystal structure of a Ba ₃ SiO ₅ : Eu ²⁺ phosphor. Non-Patent Document 2 discloses an example in which this Ba ₃ SiO ₅ : Eu ²⁺ phosphor is excited by an InGaN semiconductor laser having a wavelength of 405 nm. On the other hand, the phosphor Sr ₃ SiO ₅ : Eu ²⁺ is disclosed in Non-Patent Document 3, and Sr / Si is 3 / 0.8, 3 / 0.9, 3/1 and 3 / 1.1. The emission peak wavelengths were 559 nm, 564 nm, 568 nm and 570 nm, respectively.

Non-patent document 4 is disclosed after the first filing date of the present invention. In (Ba _1-x Sr _x ) ₃ SiO ₅ : Eu ²⁺ , when a part of the Sr site is replaced with Ba, Eu It is disclosed that ²⁺ light emission shifts to the longer wavelength side and the light emission intensity decreases. That is, the emission intensity of the (Ba _1-x Sr _x ) ₃ SiO ₅ : Eu ²⁺ phosphor disclosed here is smaller than that of Sr ₃ SiO ₅ : Eu ²⁺ . Further, there is a description that the luminance is lowered by raising the firing temperature from 1250 ° C. to 1350 ° C. with respect to Sr ₃ SiO ₅ : Eu ²⁺ . Therefore, Non-Patent Document 4 does not suggest the possibility of improving the light emission characteristics of (Ba _1-x Sr _x ) ₃ SiO ₅ : Eu ²⁺ phosphor.
Japanese Patent No. 2900928 Japanese Patent No. 2927279 Japanese Patent No. 3364229 Japanese Patent Laid-Open No. 10-163535 JP 2005-68269 A Mitsuru Yamaga and 4 others “Physical Review B” 2005, 71, 205102-1-7 Atsushi Yasuda and three others "Preliminary Proceedings of the 51st Joint Conference on Applied Physics", page 1607 Jung Kyu Park and 4 others “Applied Physics Letters” 2004, 84, 1647-1649 Ho Seong Jang and two others “Proceedings of the 12th International DisplayWorkshops in Conjunction with Asia, display 2005 volume 1”, pp. 539-542

As described above, conventionally, phosphors that emit yellow or red light based on alkaline earth metal silicates and light-emitting devices using these phosphors are known.
However, the luminous efficiency is not sufficient, and there is a demand for phosphors and light emitting devices with higher luminous efficiency. In addition, it is known that the temperature of the phosphor incorporated in the light emitting device rises to about 100 ° C. to 200 ° C., and a phosphor and a light emitting device that do not lower the luminous efficiency even when the temperature rises are required.

Accordingly, an object of the present invention is to provide an orange or red light emitting phosphor having high luminous efficiency and high brightness.
Another object of the present invention is to provide a highly efficient and highly color-rendering light-emitting device using such a phosphor having a high light-emitting efficiency, and an illumination device and an image display device using the light-emitting device.

As a result of intensive studies on the composition and crystal structure of phosphors based on alkaline earth metal silicates, the present inventors have achieved extremely high-efficiency emission within a specific composition range represented by the following formula [1]. The orange to red phosphors shown were found. Moreover, it discovered that the fluorescent substance which has a composition represented by following formula [1] was excellent in the luminous intensity maintenance factor with respect to the temperature change of fluorescent substance, and completed this invention.
That is, the gist of the present invention is as follows.

(1) A phosphor having an emission peak wavelength obtained by excitation with light having a wavelength of 455 nm in a wavelength range of 590 nm to 680 nm and having a chemical composition represented by the following formula [1B].
Sr _3- xy- Ba _x Eu _y SiO ₅ ... [1B]
(In the formula [1B], x and y represent numbers satisfying 0.5 ≦ x ≦ 1.2, 0.005 ≦ y <1, and 0 <3-xy.)
(2) The phosphor according to (1), wherein in the formula [1B], a value of y satisfies 0.01 ≦ y ≦ 0.1 .

( 3 ) The phosphor according to (1) or ( 2), wherein x = 1 in the formula [1B].

( 4 ) The phosphor according to any one of (1) to ( 3 ), wherein a substance different from the phosphor is present on the surface.
(5) different materials organic compound and phosphor, an inorganic compound, and a phosphor according to the above is at least one selected from the group consisting of a glass material (4).

( 6 ) The phosphor according to ( 4 ), wherein the substance different from the phosphor contains a metal oxide.
( 7 ) The substance different from the phosphor is present on the surface of the phosphor in an amount of 1 wt% to 50 wt% with respect to the weight of the phosphor ( 4 ) to ( 6 ) The phosphor according to any one of the above.

( 8 ) A phosphor-containing composition comprising the phosphor according to any one of (1) to ( 7 ) and a liquid medium.

( 9 ) In a light-emitting device including a first light emitter and a second light emitter that emits visible light by irradiation of light from the first light emitter, the second light emitter includes (1) to ( 7 ) A light-emitting device comprising at least one of the phosphors according to any one of ( 7 ) as a first phosphor.

(10) said second luminous body, wherein the first phosphor different at least one phosphor emission wavelengths, according to (9) that it contains as the second phosphor Light emitting device.

( 11 ) The first light emitter has a light emission peak in a wavelength range of 420 nm to 500 nm, and the second light emitter emits light in a wavelength range of 490 nm to 560 nm as the second phosphor. ( 10 ) The light-emitting device according to ( 10 ), comprising at least one phosphor having a peak.

( 12 ) The first light emitter has an emission peak in a wavelength range of 300 nm to 420 nm, and the second light emitter emits light in a wavelength range of 420 nm to 490 nm as the second phosphor. ( 10 ) The light emitting device according to ( 10 ), comprising at least one phosphor having a peak and at least one phosphor having a light emission peak in a wavelength range of 490 nm to 560 nm.

( 13 ) The light emitting device according to any one of ( 9 ) to ( 12 ), wherein the light emitting device further includes a sealing material, and a silicone resin is used as the sealing material.

( 14 ) An image display device comprising the light-emitting device according to any one of ( 9 ) to ( 13 ) as a light source.

( 15 ) An illumination device comprising the light-emitting device according to any one of ( 9 ) to ( 13 ) as a light source.

ADVANTAGE OF THE INVENTION According to this invention, it is a fluorescent substance which is light-emitted in orange thru | or red, Comprising: The fluorescent substance with high luminous efficiency, high brightness, and a high characteristic is provided.
Further, according to the present invention, an orange or red phosphor having excellent temperature characteristics is provided. If the phosphor has good temperature characteristics, it can be used for a light emitting device using a high output LED, and a light emitting device with high output and high luminance can be provided.
Further, by using a composition containing this phosphor, a light-emitting device having high efficiency and high characteristics can be obtained.
This light-emitting device is suitably used for an image display device or a lighting device.

  Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.

[1. Phosphor]
[1-1. Characteristics of phosphor
(Temperature characteristics)
The phosphor of the present invention is excellent in temperature characteristics and preferably satisfies the following formula [2] and / or [3]. In the following formulas [2] and [3], R _x (y) represents the emission peak intensity when excited with excitation light having a wavelength of x nm at a temperature of y ° C. That is, the subscript number x immediately after R indicates the wavelength (unit: nm) of the excitation light, and the numerical value y in parentheses indicates the surface temperature (unit: ° C.) of the phosphor.
85 ≦ {R ₄₅₅ (125) / R ₄₅₅ (25)} × 100 ≦ 110 (2)
92 ≦ {R ₄₀₅ (100) / R ₄₀₅ (25)} × 100 ≦ 110 (3)
(In the formula [2], R ₄₅₅ (25) is an emission peak intensity obtained by exciting the phosphor with light having a peak wavelength of 455 nm at 25 ° C.,
R ₄₅₅ (125) is an emission peak intensity obtained by exciting the phosphor with light having a peak wavelength of 455 nm at 125 ° C.
In Formula [3], R ₄₀₅ (25) is an emission peak intensity obtained by exciting the phosphor with light having a peak wavelength of 405 nm at 25 ° C.
R ₄₀₅ (100) is an emission peak intensity obtained by exciting the phosphor with light having a peak wavelength of 405 nm at 100 ° C. )

The above formula [2] means the ratio of the emission intensity R ₄₅₅ (125) at a temperature of 125 ° C. to the emission intensity R ₄₅₅ (25) at a temperature of 25 ° C., that is, the emission intensity maintenance ratio with respect to the temperature change of the phosphor.
The value of the above formula [2] is usually 85 or more, preferably 87 or more, more preferably 89 or more, still more preferably 91 or more, and usually 110 or less.

Further, the above formula [3] means the ratio of the emission intensity R ₄₀₅ (100) at a temperature of 100 ° C. to the emission intensity R ₄₀₅ (25) at a temperature of 25 ° C., that is, the emission intensity maintenance ratio with respect to the temperature change of the phosphor. To do.
The value of the above formula [3] is usually 92 or more, preferably 93 or more, more preferably 94 or more, and usually 110 or less.

  Since the emission intensity of ordinary phosphors decreases as the temperature rises, it is unlikely that the emission intensity maintenance ratio exceeds 100. However, there is no problem if it exceeds 100 for some reason. However, when the emission intensity maintenance ratio exceeds 110, the light emitting device tends to cause a color shift due to a temperature change, as in the case where the emission intensity maintenance ratio is low. Accordingly, the emission intensity maintenance rate is preferably close to 100, and most preferably 100.

In addition to the above formulas [2] and [3], the phosphor of the present invention further satisfies any one or more of the following formulas [2A], [2B], [3A], and [3B]. preferable.
92 ≦ {R ₄₅₅ (100) / R ₄₅₅ (25)} × 100 ≦ 110 (2A)
83 ≦ {R ₄₅₅ (150) / R ₄₅₅ (25)} × 100 ≦ 110 ... [2B]
88 ≦ {R ₄₀₅ (125) / R ₄₀₅ (25)} × 100 ≦ 110 ... [3A]
83 ≦ {R ₄₀₅ (150) / R ₄₀₅ (25)} × 100 ≦ 110 ... [3B]
(In the formulas [2A] and [2B], R ₄₅₅ (100) is an emission peak intensity obtained by exciting the phosphor with light having a peak wavelength of 455 nm at 100 ° C., and R ₄₅₅ (150) is It is an emission peak intensity obtained by exciting the phosphor with light having a peak wavelength of 455 nm at 150 ° C., and R ₄₅₅ (25) has the same meaning as in formula [2].
In the formulas [3A] and [3B], R ₄₀₅ (125) is an emission peak intensity obtained by exciting the phosphor with light having a peak wavelength of 405 nm at 125 ° C., and R ₄₀₅ (150) is 150 This is the emission peak intensity obtained by exciting the phosphor with light having a peak wavelength of 405 nm at ° C., and R ₄₀₅ (25) has the same meaning as in formula [3]. )

The above formula [2A] means the ratio of the emission intensity R ₄₅₅ (100) at a temperature of 100 ° C. to the emission intensity R ₄₅₅ (25) at a temperature of 25 ° C., that is, the emission intensity maintenance ratio with respect to the temperature change of the phosphor.
The value of the above formula [2A] is usually 92 or more, preferably 93 or more, more preferably 94 or more, still more preferably 95 or more, and usually 110 or less.

The above equation [2B] means the ratio of the emission intensity R ₄₅₅ (150) at a temperature of 150 ° C. to the emission intensity R ₄₅₅ (25) at a temperature of 25 ° C., that is, the emission intensity maintenance ratio with respect to the temperature change of the phosphor.
The value of the above formula [2B] is usually 83 or more, preferably 84 or more, more preferably 85 or more, still more preferably 86 or more, and usually 110 or less.

The above formula [3A] means the ratio of the emission intensity R ₄₀₅ (125) at a temperature of 125 ° C. to the emission intensity R ₄₀₅ (25) at a temperature of 25 ° C., that is, the emission intensity maintenance ratio with respect to the temperature change of the phosphor.
The value of the above formula [3A] is usually 88 or more, preferably 90 or more, more preferably 92 or more, and usually 110 or less.

The above formula [3B] means the ratio of the emission intensity R ₄₀₅ (150) at a temperature of 150 ° C. to the emission intensity R ₄₀₅ (25) at a temperature of 25 ° C., that is, the emission intensity maintenance ratio with respect to the temperature change of the phosphor.
The value of the above formula [3B] is usually 83 or more, preferably 85 or more, more preferably 87 or more, and usually 110 or less.

  When a phosphor is used in a light emitting device, the temperature of the phosphor may increase due to heat generated by a light source (a “first light emitter” described later). In particular, since a brighter light emitting device has been demanded in recent years, a high-output light source such as a power LED may be used as a light source. The degree of temperature also increases.

  If the light emission intensity maintenance rate is low, when a light emitting device is configured in combination with a GaN-based LED or the like, the light emission intensity decreases when the temperature of the phosphor increases due to the operation, and the light emission color of the light emitting device due to the temperature change Tends to change, which is not preferable. On the other hand, it is preferable that the emission intensity maintenance rate is high because the above-described decrease in emission intensity and change in emission color tend to be small. Such a decrease in emission intensity and a change in emission color due to temperature change are referred to as temperature characteristics, and a phosphor having a small change in emission intensity and emission color associated with temperature change is referred to as a phosphor having excellent temperature characteristics.

  Since the phosphor of the present invention is excellent in temperature characteristics as described above, the phosphor of the present invention can be suitably used for a light emitting device and the like to be described later.

  The emission intensity maintenance rate is, for example, a stage equipped with a MCPD7000 multi-channel spectrum measurement device manufactured by Otsuka Electronics as an emission spectrum measurement device, a color luminance meter BM5A as a luminance measurement device, a cooling mechanism using a Peltier element, and a heating mechanism using a heater. , And using a device equipped with a 150 W xenon lamp as a light source, measurement can be performed as follows.

A cell containing a phosphor sample is placed on the stage, and the temperature is changed in the range of 20 ° C to 150 ° C. It is confirmed that the surface temperature of the phosphor becomes constant at 25 ° C., 100 ° C., 125 ° C., or 150 ° C. Next, the phosphor is excited with light having a wavelength of 405 nm or 455 nm taken out from the light source by a diffraction grating, and an emission spectrum is measured. The emission peak intensity is obtained from the measured emission spectrum.
In addition, the measured value of the surface temperature of the phosphor is a value corrected by using a temperature measured value by a radiation thermometer and a thermocouple.
The relative value of the emission peak intensity obtained from the emission spectrum measured by the spectrum measuring apparatus with respect to the emission peak intensity at 25 ° C. is defined as the emission intensity maintenance ratio.

For example, the emission intensity maintenance rate at 455 nm excitation and 125 ° C. can be determined as follows.
The emission peak intensity obtained by exciting with light having a peak wavelength of 455 nm at 25 ° C. is R ₄₅₅ (25), and the emission peak intensity obtained by exciting with light having a peak wavelength of 455 nm at 125 ° C. is R ₄₅₅ (125). Then, the value calculated by {R ₄₅₅ (125) / R ₄₅₅ (25)} × 100 is defined as the emission intensity maintenance rate at 125 ° C. with excitation at 455 nm.

(Characteristics related to emission spectrum)
The fluorescence spectrum (emission spectrum) emitted by the phosphor of the present invention is not particularly limited. However, in view of the use as an orange or red phosphor, when excited with light having a wavelength of 405 nm or 455 nm, It is preferable to have the following characteristics (2) and (3).
(2) The emission peak wavelength is in the wavelength range of 570 nm to 680 nm.
(3) The full width at half maximum of the emission peak is 90 nm or less.

That is, the phosphor of the present invention usually has an emission peak in a wavelength range of 570 nm or more, preferably 580 nm or more, more preferably 590 nm or more, and usually 680 nm or less, preferably 650 nm or less, more preferably 640 nm or less. If the emission peak is shortened, the red component may be too small when configuring a white light-emitting device, making it unsuitable as a red phosphor. If the emission peak is lengthened, light with low visibility increases. In addition, the luminance of the phosphor may be reduced.
In addition, when the phosphor of the present invention has a plurality of emission peaks, the peak wavelength having the highest intensity is set as the emission peak wavelength.

The phosphor of the present invention has a full width at half maximum (hereinafter referred to as “FWHM” where appropriate) of 90 nm or less, preferably 87 nm or less, more preferably 84 nm or less. The half-value width of the emission peak is usually 50 nm or more, preferably 70 nm or more, more preferably 80 nm or more. Since the half width is narrow, light emission with a good balance between luminance and reddish components contained in the light emission of the phosphor can be obtained.
When the phosphor of the present invention has a plurality of emission peaks, the width of the wavelength region having an intensity of half or more of the intensity of the highest emission peak is defined as the half-value width.

  In order to excite the phosphor of the present invention with light having a wavelength of 405 nm or 455 nm, for example, a xenon lamp can be used. In that case, light having a desired wavelength is emitted by a diffraction grating spectrometer or the like. Take out and irradiate. A GaN LED or LD can also be used as an excitation light source. The emission spectrum of the phosphor of the present invention is measured at room temperature, for example, 25 ° C., using a 150 W xenon lamp as an excitation light source, and a fluorescence measurement apparatus equipped with a multichannel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measurement apparatus. (Manufactured by JASCO Corporation) can be used for measurement. From the obtained emission spectrum, the emission peak wavelength and peak half width can be calculated.

(Characteristics related to excitation wavelength)
The phosphor of the present invention is not particularly limited as long as it can be excited by light in the wavelength range of 200 nm to 500 nm, and the excitation wavelength is not particularly limited. For example, the phosphor of the present invention is excited by light in the blue region and / or in the near ultraviolet region. If possible, it can be suitably used for a light emitting device using a semiconductor light emitting element or the like as a first light emitter.

  The excitation spectrum is measured at room temperature, for example, 25 ° C., with a 150 W xenon lamp as an excitation light source and a fluorescence measurement apparatus (manufactured by JASCO Corporation) equipped with a multichannel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measurement apparatus. Can be measured. The excitation peak wavelength can be calculated from the obtained excitation spectrum.

(Absorption efficiency)
The phosphor of the present invention preferably has higher absorption efficiency, and the value preferably satisfies the following (4) and / or (5).
(4) When the phosphor is excited with light having a peak wavelength of 455 nm, the absorption efficiency is usually 60% or more, preferably 70% or more, more preferably 75% or more.
(5) When the phosphor is excited with light having a peak wavelength of 405 nm, the absorption efficiency is usually 85% or more, preferably 90% or more, more preferably 92% or more.

If the absorption efficiency is lower than the above range, the amount of excitation light necessary for obtaining predetermined light emission increases, and the energy consumption tends to increase, which is not preferable.
The method for measuring the absorption efficiency is as described later.

(Internal quantum efficiency)
The phosphor of the present invention preferably has higher internal quantum efficiency, and its value preferably satisfies the following (6) and / or (7).
(6) When the phosphor is excited with light having a peak wavelength of 455 nm, the internal quantum efficiency is usually 64% or more, preferably 66% or more, more preferably 68% or more, and further preferably 70% or more.
(7) When the phosphor is excited with light having a peak wavelength of 405 nm, the internal quantum efficiency is usually 56% or more, preferably 57% or more, more preferably 58% or more.

Here, the internal quantum efficiency means the ratio of the number of photons emitted to the number of photons of excitation light absorbed by the phosphor. If the internal quantum efficiency is low, the amount of excitation light necessary for obtaining predetermined light emission increases, which tends to increase energy consumption, which is not preferable.
The method for measuring the internal quantum efficiency is as described later.

(External quantum efficiency)
The phosphor of the present invention preferably has a higher external quantum efficiency, and the value preferably satisfies the following (8) and / or (9).
(8) When the phosphor is excited with light having a peak wavelength of 455 nm, the external quantum efficiency is usually 45% or more, preferably 48% or more, more preferably 50% or more.
(9) When the phosphor is excited with light having a peak wavelength of 405 nm, the external quantum efficiency is usually 48% or more, preferably 50% or more, more preferably 52% or more, and particularly preferably 54% or more.

If the external quantum efficiency is low, the amount of excitation light necessary for obtaining predetermined light emission increases, and the energy consumption tends to increase, which is not preferable.
The measuring method of the external quantum efficiency is as described later.

(Measurement method of absorption efficiency, internal quantum efficiency, and external quantum efficiency)
A method for obtaining the absorption efficiency αq, internal quantum efficiency ηi, and external quantum efficiency ηo of the phosphor will be described below.

  First, a phosphor sample to be measured (for example, a powder form) is packed in a cell with a sufficiently smooth surface so that measurement accuracy is maintained, and is attached to a condenser such as an integrating sphere. The use of a condenser such as an integrating sphere makes it possible to count all photons reflected by the phosphor sample and photons emitted from the phosphor sample due to the fluorescence phenomenon, that is, not counted but out of the measurement system. This is to eliminate the photons that fly away.

  A light-emitting source for exciting the phosphor is attached to the condenser such as an integrating sphere. This light source is, for example, an Xe lamp or the like, and is adjusted using a filter, a monochromator (diffraction grating spectrometer), or the like so that the emission peak wavelength is monochromatic light of, for example, 405 nm or 455 nm. The phosphor sample to be measured is irradiated with light from the light emission source whose emission peak wavelength is adjusted, and a spectrum including light emission (fluorescence) and reflected light is measured by a spectroscopic measurement device such as MCPD2000, MCPD7000 manufactured by Otsuka Electronics Co., Ltd. Use to measure. The spectrum measured here is actually reflected light that has not been absorbed by the phosphor among the light from the excitation light source (hereinafter simply referred to as excitation light), and the phosphor absorbs the excitation light. Thus, light of another wavelength (fluorescence) emitted by the fluorescence phenomenon is included. That is, the region near the excitation light corresponds to the reflection spectrum, and the longer wavelength region corresponds to the fluorescence spectrum (sometimes referred to herein as the emission spectrum).

The absorption efficiency αq is a value obtained by dividing the number of photons N _abs of the excitation light absorbed by the phosphor sample by the total number of photons N of the excitation light.

First, the total photon number N of the latter excitation light is obtained as follows. That is, a reflecting plate such as a substance having a reflectance R of almost 100% with respect to excitation light, for example, “Spectralon” manufactured by Labsphere (having a reflectance R of 98% with respect to excitation light of 450 nm) is measured. In the same manner as the phosphor sample, it is attached to a condenser such as the integrating sphere described above, and the reflection spectrum I _ref (λ) is measured using the spectrometer. The numerical value of the following (formula I) obtained from the reflection spectrum I _ref (λ) is proportional to N.

Here, the integration interval may be substantially performed only in the interval in which I _ref (λ) has a significant value.
The number N _abs of the photons in the excitation light that is absorbed in the phosphor sample is proportional to the amount calculated by the following equation (II).

Here, I (λ) is a reflection spectrum when a phosphor sample for which the absorption efficiency αq is to be obtained is attached. The integration interval in (Formula II) is the same as the integration interval defined in (Formula I). By limiting the integration interval in this way, the second term in (Equation II) corresponds to the number of photons generated by reflecting the excitation light from the phosphor sample to be measured, that is, as the measurement target. Among all photons generated from the phosphor sample, the photons derived from the fluorescence phenomenon are excluded. Since an actual spectrum measurement value is generally obtained as digital data divided by a certain finite bandwidth with respect to λ, the integrals of (Equation I) and (Equation II) are obtained by the summation based on the bandwidth.
From the above, αq = N _abs / N = (Formula II) / (Formula I).

Next, a method for obtaining the internal quantum efficiency ηi will be described. ηi is a value obtained by dividing the number N _abs of photons number NPL of photons originating from the fluorescence phenomenon absorbed by the phosphor sample.
Here, NPL is proportional to the amount obtained by the following (formula III).

At this time, the integration interval is limited to the wavelength range of photons derived from the fluorescence phenomenon of the phosphor sample. This is because the contribution of photons reflected from the phosphor sample is removed from I (λ). Specifically, the lower limit of the integration interval of (Equation III) is the upper end of the integration interval of (Equation I), and the upper limit is a range necessary and sufficient to include photons derived from fluorescence.
As described above, the internal quantum efficiency ηi is obtained as ηi = (formula III) / (formula II).

The integration from the spectrum that has become digital data is the same as the case where the absorption efficiency αq is obtained.
Then, the external quantum efficiency ηo is obtained by taking the product of the absorption efficiency αq and the internal quantum efficiency ηi obtained as described above. Or it can also obtain | require from the relationship of (eta) == (Formula III) / (Formula I). ηo is a value obtained by dividing the number NPL of photons derived from fluorescence by the total number N of photons of excitation light.

(Weight median diameter (D ₅₀ ))
The phosphor of the present invention has a weight median diameter of usually 1 μm or more, preferably 2 μm or more, more preferably 10 μm or more, and usually 40 μm or less, preferably 30 μm or less, more preferably 26 μm or less. preferable. If the weight median diameter is too small, the luminance is lowered and the phosphor particles tend to aggregate, which is not preferable. On the other hand, when the weight median diameter is too large, there is a tendency that uneven coating or blockage of a dispenser or the like occurs, which is not preferable.

  The weight median diameter of the phosphor of the present invention can be measured using a device such as a laser diffraction / scattering particle size distribution measuring device.

(Characteristics of fluorescent color)
The phosphor of the present invention usually emits orange or red light.
When the phosphor of the present invention emits orange or red light, the chromaticity coordinates of the fluorescence are usually (x, y) = (0.52, 0.48), (0.44, 0.40), The coordinates are within the region surrounded by (0.56, 0.20) and (0.72, 0.28), and preferably (x, y) = (0.52, 0.48), (0. 48, 0.44), (0.64, 0.24), and (0.72, 0.28).

  The chromaticity coordinates x and y of fluorescence can be measured by calculating according to JIS Z 8724 (color measurement method-light source color) using the emission spectrum of the phosphor. However, in the present invention, light in the wavelength range of 400 nm or more and 480 nm or less is used as the excitation light, and calculation is performed using only the portion of the emission spectrum of 480 nm or more in order to eliminate the influence of the unabsorbed excitation light. To do.

(composition)
The phosphor of the present invention preferably contains Eu and / or Ce as an activator, and contains Eu from the viewpoint of easily obtaining a phosphor having high luminous efficiency (internal quantum efficiency, external quantum efficiency). It is more preferable that Si is contained together with Eu.

[1-2. Phosphor represented by Formula [1]
[1-2-1. composition]
The phosphor of the present invention preferably has a chemical composition represented by the following formula [1].
M ¹ _3-xy Ba _x M ² _y M ³ _a M ⁶ _d ... [1]
(In the formula [1], M ¹ represents at least one element selected from the group consisting of alkaline earth metal elements excluding Ba and Zn.
M ² represents at least one activation element selected from the group consisting of Eu, Ce, Cr, Mn, Sm, Tm, Tb, Er, and Yb.
M ³ represents a tetravalent element containing at least Si.
M ⁶ represents at least one element selected from the group consisting of N, O, and S.
x and y are respectively
0 <x <3
0 <y <1
0 <3-xy
Represents a number that satisfies
a and d are respectively
a is 0.5 ≦ a ≦ 1.5
d is 4.5 ≦ d ≦ 5.5.
Represents a number that satisfies )

The phosphor represented by the above formula [1] is characterized by containing Ba as an essential element and further containing at least one alkaline earth metal element excluding Ba.
Hereinafter, Formula [1] will be described in detail.

<M ¹ >
In Formula [1], M ¹ represents at least one element selected from the group consisting of an alkaline earth metal element excluding Ba and Zn. Here, the alkaline earth metal element refers to Be, Mg, Ca, Sr, Ba, and Ra. The M ^1, may contain any one of these elements alone, or two or more may be of them together in any combination and in any ratio. M ¹ is more preferably one or more selected from the group consisting of Be, Mg, Ca, Sr, and Ba, and more preferably one or more selected from the group consisting of Mg, Ca, and Sr. Further preferred. Among these, it is preferable to contain at least Sr, and it is more preferable to mainly contain Sr. The content of Sr with respect to the entire M ¹ is preferably 60 mol% or more, more preferably 80 mol% or more, and particularly preferably 100 mol%.
Incidentally, the inclusion of Sr as M ^1, the effect of improving durability against hydrolysis of the phosphors.

<M ² >
In the formula [1], M ² represents an activator element. Specific examples of M ² include transition metal elements such as Cr and Mn; rare earth elements such as Eu, Sm, Tm, Yb, Ce, Tb, and Er; As M ² , any one of these elements may be contained alone, or two or more may be contained in any combination and ratio. Among them, as M ² , one or more elements selected from the group consisting of Sm, Eu, and Yb are preferable, and it is more preferable that M ² includes Eu because M ² can obtain suitable red light emission. More preferably, all of M ² is Eu.

<M ³ >
In Formula [1], M ³ represents a tetravalent metal element containing at least Si. M ³ is preferably composed mainly of Si, and the content of Si with respect to the entire M ³ is preferably 80% or more, more preferably 95 mol% or more, and more preferably 100 mol%. As M ³ , Ge, Ti, Zr or the like may substitute a part of Si, but from the viewpoint of red emission intensity or the like, the ratio of Si being substituted by other elements should be as low as possible. Specifically, the content of other elements such as Ge is preferably 20 mol% or less of Si, more preferably 5 mol% or less.

<M ⁶ >
In the formula [1], M ⁶ represents at least one element selected from the group consisting of N, O, and S. As M ⁶ , any one of these elements may be contained alone, or two or more may be contained in any combination and ratio. M ⁶ contains O, and may contain N and / or S in addition to O. Among these, M ⁶ is preferably mainly composed of O, and particularly preferably all of O.
For example, when M ⁶ contains N and / or O, the ratio of O to N (O: N) is preferably 0.9: 0.1 to 1: 0, and 0.95: 0. It is more preferable that it is 05-1: 0.

<Preferable range of x and y>
In the formula [1], x is a number representing the number of moles of Ba, and is preferably close to 1, but is usually larger than 0, preferably 0.5 or more, more preferably 0.7 or more, and particularly preferably. Represents a number of 0.8 or more and usually smaller than 3, preferably 2.5 or less, more preferably 2 or less, still more preferably 1.5 or less, and particularly preferably 1.2 or less. By adjusting the value of x within the above range, a phosphor having high emission intensity and high durability can be obtained.

In the above formula [1], y is a number representing the number of moles of M ² and is usually larger than 0, preferably 0.001 or more, more preferably 0.005 or more, further preferably 0.01 or more, most Preferably, it represents a number of 0.015 or more, usually less than 1, preferably 0.3 or less, more preferably 0.15 or less, particularly preferably 0.1 or less, and most preferably 0.05 or less. By adjusting the value of y, the emission intensity and emission wavelength can be adjusted. If the value of y is too small, the emission intensity tends to be small. On the other hand, even if the value of y is too large, the emission intensity tends to decrease due to a phenomenon called concentration quenching.

A phosphor with high emission intensity can be obtained by adjusting the values of x and y within the above ranges. Among them, M ¹ consists only of Sr, the value of x is 0.9 or more and 1.1 or less, and 3-xy, that is, the number of moles of M ¹ is 1.7 or more, 2.2. The following is more preferable because the emission intensity is particularly high. Most preferably, M ¹ is composed only of Sr and x = 1, and the host crystal, Sr ₂ BaSiO ₅ , in which the molar ratio of M ¹ to Ba is 2: 1, is added to the activating element M ^2. Is partially replaced. In this case, the internal quantum efficiency and emission intensity of the phosphor are remarkably increased, and the temperature characteristics are also good. Furthermore, since the emission peak wavelength is shifted to the longer wavelength side, a phosphor having a high emission spectrum at a wavelength of 630 nm, that is, a phosphor with a lot of reddish components can be obtained. Since the above-mentioned phosphors in which x and y are in a specific range are phosphors having a good balance between luminance and reddish components, the use of this phosphor makes it possible to manufacture a light emitting device with high characteristics.

Patent Document 5 discloses (Ba _1-a Sr _a ) ₃ SiO ₅ : Eu ^2+, but it is only disclosed as a simple mixed crystal of Sr ₃ SiO ₅ and Ba ₃ SiO ₅ . In such a case, it is generally assumed that the characteristics of the intermediate composition change monotonously as the composition changes. In the present invention, surprisingly, the composition of Sr and Ba of the parent crystal A ratio of 2: 1 has been found to be optimal.

The improvement in temperature characteristics and internal quantum efficiency is related not only to the molar ratio of M ¹ and Ba but also to the composition ratio (value of y) of the activation element M ² in the formula [1]. As the value of y is smaller, temperature characteristics and internal quantum efficiency tend to be improved.

  Further, if the value of x is smaller than the above range, the emission of the phosphor can be made longer. Thereby, when it is set as the light emitting device, the red light emission which is insufficient in the light emitting device using the conventional YAG phosphor is enhanced, and a white light emitting device with high color rendering can be obtained. In this case, in the formula [1], x is usually 0.2 or more, preferably 0.5 or more, and usually 2 or less, preferably 1.5 or less, more preferably 1 or less, particularly preferably 0. Represents a number of 8 or less.

<Preferable range of a and d>
In the formula [1], a is a number representing the number of moles of M ³ , and specifically, preferably close to 1, but usually 0.5 or more, preferably 0.7 or more, more preferably The number is 0.9 or more, usually 1.5 or less, preferably 1.3 or less, more preferably 1.1 or less. If the value of a is too small or too large, heterogeneous crystals appear and the light emission characteristics tend to deteriorate.

In the above formula [1], d is a number representing the number of moles of M ⁶ , specifically, preferably close to 5, but usually 4.5 or more, preferably 4.7 or more, more preferably The number is 4.9 or more, more preferably 4.95 or more, and usually 5.5 or less, preferably 5.3 or less, more preferably 5.1 or less, and further preferably 5.05 or less. If the value of d is too small or too large, heterogeneous crystals appear and the light emission characteristics tend to deteriorate.

<Preferred chemical composition>
The chemical composition of the formula [1] is particularly preferably represented by the following formula [1B].
Sr _3- xy- Ba _x Eu _y SiO ₅ ... [1B]
(In the formula [1B], x and y represent numbers satisfying 0 <x <3, 0 <y <1, and 0 <3-xy.)

  In the formula [1B], the preferable range of x, y, 0 <3-xy is the same as that in the formula [1], but it is particularly preferable that x = 1.

<Specific examples of preferred composition>
Specific examples of preferable ones among the chemical compositions represented by the formula [1], preferably the formula [1B] are given below, but the composition of the phosphor of the present invention is not limited to the following examples.
That is, preferable examples of the chemical composition of the formula [1] include Sr _1.98 Ba ₁ SiO ₅ : Eu _0.02 and Sr _1.97 Ba ₁ SiO ₅ : Eu _0.03 . These have high emission intensity and are preferable examples.
Specific examples of the emission wavelength longer than that of the long wavelength include Sr _2.18 Ba _0.8 SiO ₅ : Eu _0.02 and Sr _2.48 Ba _0.5 SiO ₅ : Eu _0.02. .

[1-2-2. Crystal structure]
The crystal structures of Sr ₃ SiO ₅ and Ba ₃ SiO ₅ are known, and Table 1 and Table 2 show these crystal structure parameters. These two structures are almost the same structure (arrangement of atoms) although the space groups are different. These have different space groups because the lattice constants and the atomic coordinates of each atom are slightly different, and in particular the symmetry of the position of the oxygen atom is different.

The present inventors analyzed the crystal structure in detail by pattern-fitting powder X-ray diffraction data of the Sr ₂ BaSiO ₅ : Eu phosphor of the present invention by the Rietveld method. As a result, it has been found that a phosphor having a specific state in which the distribution of alkaline earth metal atoms in the crystal is described below has particularly high characteristics such as luminance. The Rietveld analysis was carried out using the analysis program Rietan 2000 with reference to Izumi Nakai and Fujio Izumi, “Actual of Powder X-ray Analysis—Introduction to the Rietveld Method” published by Asakura Shoten (2002).

The Sr ₂ BaSiO ₅ : Eu phosphor, which is a representative composition of the phosphor of the present invention, has almost the same crystal structure as Sr ₃ SiO ₅ or Ba ₃ SiO _5, and the occupied positions in the crystal of alkaline earth metal atoms ( Hereinafter, there are two types of sites). In these three types of phosphors, a site having a large coordination number of oxygen and a large coordination distance (wide site) and a site having a small coordination number and a small coordination distance (narrow site) are 1: Exists in a ratio of two. In the Sr ₂ BaSiO ₅ : Eu phosphor, it is considered that Sr is occupied at a narrow site and Ba is occupied at a wide site, so that the crystal structure is stabilized and light emission with high luminance can be obtained. In particular, the occupation ratio of Ba in a wide site is preferably 50% or more, and more preferably 70% or more. In addition, the Sr occupancy ratio of the narrow site is preferably 50% or more, and more preferably 70% or more.

Further, data will be shown in detail later as examples, but as a result of analysis by the Rietveld method, the phosphor of the present invention is the same space group as Sr ₃ SiO ₅ , P4 / ncc (No. 130), or Ba ₃ It was found that the crystal belongs to any one of the space groups of I4 / mcm (No. 140), which is the same space group as that of SiO ₅ . Assuming which space group is used, fitting data with almost the same accuracy can be obtained, so it has not been possible to determine which space group it belongs to. I4 / mcm (No. 140) is a space group having slightly higher symmetry, and belongs to the same space group as Cs ₃ CoCl ₅ .

  Regardless of the space group of the phosphor of the present invention, it can be considered that a phosphor having high characteristics can be obtained by selectively arranging Ba at a wide site and Sr at a narrow site. That is, in the case of P4 / ncc, a wide site is a site belonging to the wickoff symbol 4c, and a narrow site is a site belonging to the wickoff symbol 8f. On the other hand, in the case of I4 / mcm, a wide site is a site belonging to the wyckoff symbol 4a, and a narrow site is a site belonging to the wyckoff symbol 8h.

  In addition, the details regarding the space group and symmetry of the crystal were in accordance with INTERNATIONAL TABLES FOR CRYSTALLOGRAPY (Third, Revised Edition), Volume A SPACE-GROUP SYMMETRY.

  Such a phosphor of the present invention emits light not only by ultraviolet rays and visible rays but also by electron beams, X-rays, electric fields, and the like. Therefore, in addition to the light emitting device of the present invention using a semiconductor light emitting element such as an LED or LD described later as an excitation light source, it can be effectively used as a phosphor utilizing the above excitation means.

As for the phosphor of the present invention, practical characteristics other than the light emission characteristics are described. Ba ₃ SiO ₅ has a problem that it is easily hydrolyzed, but the phosphor of the present invention has a problem such as Ba ₃ SiO _5. do not do.

[1-2-3. surface treatment]
As described above, the phosphor of the present invention is excellent in hydrolysis resistance, but in order to further improve the weather resistance such as moisture resistance, or to improve the dispersibility of the phosphor in the phosphor-containing portion of the light emitting device described later. In order to achieve this, the phosphor of the present invention can be surface-treated, that is, the surface of the phosphor can be coated with a different substance, so that a different substance can be present on the surface of the phosphor.

  Examples of the substance that can be present on the surface of the phosphor (hereinafter, arbitrarily referred to as “surface treatment substance”) include organic compounds, inorganic compounds, and glass materials.

  Examples of the organic compound include hot-melt polymers such as acrylic resin, polycarbonate, polyamide, and polyethylene, latex, and polyorganosiloxane.

  Examples of inorganic compounds include magnesium oxide, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, tin oxide, germanium oxide, tantalum oxide, niobium oxide, vanadium oxide, boron oxide, antimony oxide, zinc oxide, yttrium oxide, and bismuth oxide. Metal oxides such as silicon nitride and aluminum nitride, orthophosphates such as calcium phosphate, barium phosphate and strontium phosphate, and polyphosphates.

  Examples of the glass material include borosilicate, phosphosilicate, and alkali silicate.

  These surface treatment substances may be used in combination of two or more.

The phosphor obtained by the surface treatment is premised on the presence of a surface treatment substance, and examples of the mode include the following.
(i) A mode in which the surface treatment substance constitutes a continuous film and covers the phosphor surface
(ii) A mode in which the surface treatment substance becomes a large number of fine particles and adheres to the surface of the phosphor to coat the surface of the phosphor

  The adhesion amount or the coating amount of the surface treatment substance on the surface of the phosphor is usually 1% by weight or more, preferably 5% by weight or more, more preferably 10% by weight or more, and usually 50% by weight based on the weight of the phosphor. % By weight or less, preferably 30% by weight or less, more preferably 20% by weight or less. If the amount of the surface treatment substance with respect to the phosphor is too large, the light emission characteristics of the phosphor may be impaired. If the amount is too small, the surface coating may be incomplete, and the moisture resistance and dispersibility may not be improved.

  Moreover, the film thickness (layer thickness) of the surface treatment substance formed by the surface treatment is usually 10 nm or more, preferably 50 nm or more, and usually 2000 nm or less, preferably 1000 nm or less. If this film thickness is too thick, the light emission characteristics of the phosphor may be impaired. If it is too thin, the surface coating may be incomplete, and the moisture resistance and dispersibility may not be improved.

  The surface treatment method is not particularly limited, and examples thereof include a coating treatment method using a metal oxide (silicon oxide) as described below.

  The phosphor of the present invention is added to an alcohol such as ethanol and stirred, and an alkaline aqueous solution such as aqueous ammonia is further added and stirred. Next, a hydrolyzable alkyl silicate such as tetraethylorthosilicate is added and stirred. The obtained solution is allowed to stand for 3 to 60 minutes, and then the supernatant containing silicon oxide particles that have not adhered to the phosphor surface is removed with a dropper or the like. Next, after adding alcohol, stirring, standing, and removing the supernatant several times, the surface-treated phosphor is obtained through a reduced-pressure drying step at 120 ° C. to 150 ° C. for 10 minutes to 5 hours, for example, 2 hours.

  Other methods for surface treatment of the phosphor include, for example, a method in which spherical silicon oxide fine powder is adhered to the phosphor (JP-A-2-209998, JP-A-2-233794), and a phosphor-based silicon compound. A method of attaching a film (Japanese Patent Laid-Open No. 3-231987), a method of coating the surface of phosphor fine particles with polymer fine particles (Japanese Patent Laid-Open No. 6-314593), a phosphor with an organic material, an inorganic material, a glass material, etc. A coating method (Japanese Patent Laid-Open No. 2002-223008), a method of coating a phosphor surface by a chemical vapor reaction method (Japanese Patent Laid-Open No. 2005-82788), and a method of attaching metal compound particles (Japanese Patent Laid-Open No. 2006-2006) No. 28458) can be used.

[1-3. Method for producing phosphor]
The method for producing the phosphor of the present invention is not particularly limited. For example, in the formula [1], the raw material of the metal element M ¹ (hereinafter referred to as “M ¹ source” as appropriate) and the Ba raw material (hereinafter referred to as “Ba source as appropriate”). ), A raw material of the metal element M ² (hereinafter referred to as “M ² source” as appropriate), and a raw material of the metal element M ³ (hereinafter referred to as “M ³ source” as appropriate) (mixing step) to obtain It can manufacture by baking the obtained mixture (baking process).

<Raw material>
Examples of the M ¹ source, Ba source, M ² source, and M ³ source used in the production of the phosphor of the present invention include oxides and hydroxides of each element of M ¹ , Ba, M ² , and M ^3. , Carbonate, nitrate, sulfate, oxalate, carboxylate, halide and the like. From these compounds, the reactivity to the composite oxide, the low generation amount of NO _x , SO _{x and the} like during firing may be selected as appropriate.

Specific examples of the M ¹ source are listed as follows for each type of M ¹ metal.
Specific examples of the Sr source include SrO, Sr (OH) ₂ .8H ₂ O, SrCO ₃ , Sr (NO ₃ ) ₂ , SrSO ₄ , Sr (OCO) ₂ .H ₂ O, Sr (OCOCH ₃ ) _2. 0.5H ₂ O, SrCl _{2 and the} like can be mentioned. Among these, SrCO ₃ is preferable. This is because the stability in the air is good, it is easily decomposed by heating, it is difficult for undesired elements to remain, and it is easy to obtain high-purity raw materials.

Specific examples of the Mg source include MgO, Mg (OH) ₂ , basic magnesium carbonate (mMgCO ₃ .Mg (OH) ₂ .nH ₂ O), Mg (NO ₃ ) ₂ .6H ₂ O, MgSO ₄ , Mg (OCO) ₂ · 2H ₂ O, Mg (OCOCH ₃ ) ₂ · 4H ₂ O, MgCl _{2 and the} like. Of these, MgO and basic magnesium carbonate are preferred.

Specific examples of the Ca source or Be source include CaO, Ca (OH) ₂ , CaCO ₃ , Ca (NO ₃ ) ₂ .4H ₂ O, CaSO ₄ .2H ₂ O, and Ca (OCO) ₂ .H ₂ O. , Ca (OCOCH ₃ ) ₂ .H ₂ O, CaCl ₂ , BeO and the like. Of these, CaCO ₃ , CaCl _{2 and the} like are preferable.

Specific examples of the Zn source include zinc compounds such as ZnO, ZnF ₂ , ZnCl ₂ and Zn (OH) ₂ (however, they may be hydrates). Of these, ZnF ₂ .4H ₂ O (however, it may be an anhydride) is preferable from the viewpoint that the effect of promoting particle growth is high.

Specific examples of the Ba source include BaO, Ba (OH) ₂ .8H ₂ O, BaCO ₃ , Ba (NO ₃ ) ₂ , BaSO ₄ , Ba (OCO) ₂ .H ₂ O, Ba (OCOCH ₃ ) ₂ , BaCl _2, and the like. Of these, BaCO ₃ is preferable. This is because the stability in the air is good, and it is easily decomposed by heating, so that undesired elements hardly remain and it is easy to obtain high-purity raw materials.

Among the M ² sources, examples of Eu sources include Eu ₂ O ₃ , Eu ₂ (SO ₄ ) ₃ , Eu ₂ (OCO) ₆ , EuCl ₂ , EuCl ₃ , Eu (NO ₃ ) ₃ · 6H ₂ O Etc. Of these, Eu ₂ O _{3 and the} like are preferable. Further, specific examples of the Sm source, Ce source, Tm source, Yb source, Cr source, Mn source, Tb source, Er source and the like include Eu in each compound given as a specific example of the Eu source. , Tm, Yb, Cr, Mn, Tb, Er, and the like.

Among the M ³ sources, specific examples of the Si source include SiO ₂ , H ₄ SiO ₄ , Si (OCOCH ₃ ) _{4 and the} like. Of these, highly reactive SiO ₂ such as Aerosil is preferable. Specific examples of the Ge source, Ti source, Zr source, and the like include compounds in which Si is replaced with Ge, Ti, Zr, etc. in the respective compounds listed as specific examples of the Si source.

  Each of these element source compounds may be used alone or in combination of two or more in any combination and ratio.

<Mixing process>
The method of mixing the M ¹ source, the Ba source, the M ² source, and the M ³ source is not particularly limited, and examples thereof include the following methods (A) and (B).

(A) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., or pulverization using mortar and pestle, etc. and mixer such as ribbon blender, V-type blender, Henschel mixer, or mortar and pestle A dry mixing method in which mixing is performed and raw materials such as an M ¹ source, a Ba source, an M ² source, and an M ³ source are pulverized and mixed.

(B) Add a solvent or dispersion medium such as water to the raw materials such as M ¹ source, Ba source, M ² source, and M ³ source, and mix them using a pulverizer, mortar and pestle, or evaporating dish and stir bar. And a wet mixing method in which the solution or slurry is dried and then dried by spray drying, heat drying, or natural drying.
In the above (B), in order to uniformly mix Eu, other raw materials may be mixed in an Eu aqueous solution such as Eu (NO ₃ ) ₃ .6H ₂ O, and the raw material mixture may be heated and dried.

<Flux>
In addition to the above raw materials, a flux may be mixed from the viewpoint of growing good crystals. The type of flux is not particularly limited, examples, _NH 4 ammonium halide, such as Cl or _{NH 4 F · HF, NaCO 3} , alkali metal carbonate such as LiCO _3, LiCl, NaCl, alkali metal halide of KCl etc. , Alkaline earth metal halides such as CaCl ₂ , CaF ₂ , BaF ₂ , borate compounds such as B ₂ O ₃ , H ₃ BO ₃ , NaB ₄ O ₇ , Li ₃ PO ₄ , NH ₄ H ₂ PO _And phosphate compounds such as ₄ , zinc compounds such as zinc oxide, zinc halide and zinc sulfide, and periodic table group 15 element compounds such as Bi ₂ O ₃ . Among these, alkali metal halides, alkaline earth metal halides, and Zn halides are preferable. Of these halides, fluorides and chlorides are preferred.

  The amount of flux used varies depending on the type of raw material and the material of the flux, but is usually 0.01% by weight or more, more preferably 0.1% by weight or more, and usually 20% by weight or less, further 10% by weight or less. The range of is preferable. If the amount of flux used is too small, the effect of the flux will not appear, and if the amount of flux used is too large, the flux effect will be saturated, or it will be incorporated into the host crystal and change the emission color or cause a decrease in brightness There is. These fluxes may be used alone or in combination of two or more in any combination and ratio.

<Baking process>
(Baking conditions)
In the firing step, a mixture of raw materials such as M ¹ source, Ba source, M ² source, and M ³ source obtained by the above mixing step is usually used as a crucible or a tray made of a material that is less reactive with each raw material. It is carried out by placing in a heat-resistant container and heating.

  Materials for the heat-resistant container used at the time of firing include ceramics such as alumina, quartz, boron nitride, metals such as platinum, molybdenum, tungsten, tantalum, niobium, iridium, rhodium, alloys containing them as a main component, carbon (graphite ) And the like. Here, the heat-resistant container made of quartz can be used for heat treatment at a relatively low temperature, that is, 1200 ° C. or less, and a preferable use temperature range is 1000 ° C. or less.

  Among the examples of the material of the heat-resistant container, it is preferable to use a metal or a metal alloy that does not easily react with the phosphor component of the present invention because the impurity element can be prevented from being mixed into the phosphor. When firing in an air atmosphere or in a weak reducing atmosphere, it is preferable to use a platinum heat-resistant container. When firing in a reducing atmosphere, heat resistance such as molybdenum, tungsten, or tantalum is used. It is preferred to use a container. Moreover, although boron nitride is ceramics, since it has low reactivity, it is preferable for firing in a reducing atmosphere.

  As for the material of the heat-resistant container, for example, when platinum or molybdenum is selected, it is not necessary that all of the heat-resistant container is platinum or molybdenum, and at least the portion where the phosphor raw material mixture and the heat-resistant container are in contact is made of platinum. Or made of molybdenum. For example, platinum foil or molybdenum foil may be spread over the bottom and side surfaces of an alumina heat-resistant container.

Further, and if adding the flux to the raw material mixture, when adding M ⁴ source and / or M ⁵ source raw material mixture, as the material of the heat-resistant container, alumina, magnesia, Ltd., calcia made, zirconia Boron nitride, silicon nitride, silicon carbide, carbon and the like are preferable, and alumina is more preferable.
In the primary firing and the secondary firing described later, heat resistant containers of the same material or heat resistant containers of different materials may be used.

  The temperature during firing varies depending on the type of raw material, mixed state, particle size, form, etc., but is usually 500 ° C. or higher, preferably 1000 ° C. or higher, more preferably 1200 ° C. or higher, even more preferably 1400 ° C. or higher. The temperature is most preferably 1500 ° C. or higher, and usually 1800 ° C. or lower, preferably 1700 ° C. or lower, more preferably 1600 ° C. or lower. If the temperature at the time of firing is too high, the light emission intensity may decrease due to reaction with the container containing the raw materials, volatilization of the raw material components, or the like. If the temperature is too low, the reaction between the raw materials may be insufficient, and the target crystal phase may not be generated, or even if the target crystal phase is obtained, the crystallinity is low and the emission intensity may be reduced.

  The pressure during firing varies depending on the firing temperature or the like, but is usually 0.01 MPa or more, preferably 0.08 MPa or more, and usually 1 MPa or less, preferably 0.12 MPa or less, and it is under atmospheric pressure. preferable. If the pressure is too low or too high, the cost of equipment such as an electric furnace increases, which is not preferable.

  The firing time varies depending on the temperature and pressure during firing, but is usually 10 minutes or longer, preferably 1 hour or longer, more preferably 2 hours or longer, usually 24 hours or shorter, preferably 10 hours or shorter.

It is preferable to select a necessary atmosphere so that the activating element is in an ionic state (valence) contributing to light emission. For example, when Eu is included as an activator element, Eu ²⁺ needs to be Eu ²⁺ in order to emit light. However, Eu sources that are contained in the form of Eu ³⁺ , such as Eu ₂ O ₃ , are usually used. Therefore, in order to reduce Eu ³⁺ to Eu ²⁺ , firing in a reducing atmosphere is preferred, and firing in a strong reducing atmosphere is more preferred.

  Specific examples of the firing atmosphere include a carbon monoxide atmosphere, a hydrogen atmosphere, a hydrogen-containing nitrogen atmosphere, a carbon-containing strong reducing atmosphere, a hydrogen-containing argon atmosphere, and the like. Among these, a hydrogen-containing nitrogen atmosphere and a carbon-containing strong reducing atmosphere are preferable, and hydrogen-containing nitrogen is more preferable from an economical viewpoint.

  When hydrogen-containing nitrogen is used as the firing atmosphere, it is preferable to lower the oxygen concentration in the electric furnace to 20 ppm or less. Furthermore, the hydrogen content in the atmosphere is preferably 1% by volume or more, more preferably 2% by volume or more, and preferably 5% by volume or less. This is because if the hydrogen content in the atmosphere is too high, there is a risk of explosion, and if it is too low, a sufficient reducing atmosphere cannot be achieved.

In the primary firing and the secondary firing described later, the same firing atmosphere may be used, or different firing atmospheres may be used.
For example, in the case of the primary firing described later, in order to efficiently remove volatile components from the raw material compound, it is preferable to heat under conditions in which the circulation amount of the atmospheric gas is large. On the other hand, in the secondary firing described later, for example, in order to reduce Eu ³⁺ to Eu ²⁺ , it is preferable to heat in a reducing atmosphere containing hydrogen or carbon.

As described above, by setting the firing atmosphere to an appropriate reducing atmosphere, the ratio of Eu ²⁺ in the total Eu in the phosphor is preferably 60% or more, more preferably 80% or more, 90 % Or more is more preferable. If the ratio of Eu ²⁺ in the total Eu in the phosphor is too low, the emission intensity may be reduced.

The ratio of Eu ^{2+ in} the total Eu contained in the phosphor can be examined, for example, by measuring an X-ray absorption fine structure. That is, when the L3 absorption edge of Eu atom is measured, Eu ²⁺ and Eu ³⁺ show separate absorption peaks, and the ratio can be determined from the area. Further, the ratio of Eu ^{2+ in} the total Eu contained in the phosphor can also be known by measuring electron spin resonance (ESR).

(Primary firing and secondary firing)
In the firing step, firing at 1200 ° C. or higher is preferably performed at least once, and final baking is preferably performed at 1000 ° C. or higher in a reducing atmosphere. More preferably, the firing step is divided into primary firing and secondary firing, and the raw material mixture obtained by the mixing step is first primarily fired, and then pulverized and sieved again with a ball mill or the like, followed by secondary firing.
That is, in primary firing, in order to efficiently remove volatile components from the raw material compound, heating is performed under conditions with a large amount of atmospheric gas flow, and in secondary firing, for example, Eu ³⁺ is reduced to Eu ²⁺ , It is preferable to heat in a reducing atmosphere containing carbon and carbon. Further, in the secondary firing, it is preferable to heat at a higher temperature than the primary firing in order to improve the crystallinity of the phosphor and sufficiently reduce it to Eu ²⁺ .

(Post-processing)
After the firing step described above, the phosphor of the present invention can be obtained by performing treatments such as pulverization, washing, classification, and surface treatment as necessary. For the pulverization treatment, pulverizers listed as being usable in the raw material mixing step can be used. The washing can be performed with water such as deionized water, an organic solvent such as ethanol, or an alkaline aqueous solution such as ammonia water. The classification treatment can be performed by water sieving or by using various classifiers such as various air classifiers and vibration sieves. In particular, when dry classification using a nylon mesh is used, a phosphor with good dispersibility having a weight median diameter of about 20 μm can be obtained.

  In addition, when manufacturing a light-emitting device by the below-mentioned method using the obtained fluorescent substance, you may perform annealing treatment at low temperature and surface treatment by an inorganic substance or organic substance as needed. Among them, [1-2-3. It is preferable to use after performing the surface treatment described in [Surface Treatment].

[1-4. Use of phosphor]
The phosphor of the present invention can be used for any application that uses the phosphor. In particular, taking advantage of the fact that it can be excited by blue light or near-ultraviolet light, various light emitting devices (see “ The light-emitting device of the invention ") can be suitably used. By adjusting the types and usage ratios of the phosphors to be combined, light emitting devices having various emission colors can be manufactured. In particular, since the phosphor of the present invention is an orange or red phosphor, a white light emitting device can be manufactured by combining an excitation light source emitting blue light and a green phosphor. The emission color in this case can be changed to a preferred emission color by adjusting the emission wavelength of the phosphor of the present invention or the green phosphor. For example, so-called pseudo white (for example, blue LED and yellow phosphor) An emission spectrum similar to the emission spectrum of the emission color of the light-emitting device combining the above can also be obtained. Furthermore, combining this white light-emitting device with a red phosphor (phosphor that emits red fluorescence) realizes a light-emitting device that excels in red color rendering and a light-emitting device that emits light bulb color (warm white). can do. Even if the phosphor of the present invention is combined with a blue phosphor (a phosphor that emits blue fluorescence) and a green phosphor (a phosphor that emits green fluorescence) in combination with an excitation light source that emits near-ultraviolet light, white light is emitted. The device can be manufactured.

  The emission color of the light-emitting device is not limited to white, and if necessary, a yellow phosphor (phosphor that emits yellow fluorescence), a blue phosphor, a green phosphor, and other types of orange or red phosphor may be combined. Thus, a light-emitting device that emits light of any color can be manufactured by adjusting the type and usage ratio of the phosphor. The light-emitting device thus obtained can be used as a light-emitting portion (particularly a liquid crystal backlight) or an illumination device of an image display device.

[1-5. Phosphor-containing composition]
When the phosphor of the present invention is used for a light emitting device or the like, it is preferably used in a form dispersed in a liquid medium. The phosphor of the present invention dispersed in a liquid medium will be referred to as “the phosphor-containing composition of the present invention” as appropriate. The phosphor-containing composition of the present invention may contain only one type of the phosphor of the present invention, or may contain two or more types.

  The liquid medium that can be used in the phosphor-containing composition of the present invention is a liquid medium that exhibits liquid properties under the desired use conditions, and that suitably disperses the phosphor of the present invention and does not cause undesirable reactions. If there is, it is possible to select an arbitrary one according to the purpose. Examples of the liquid medium include a thermosetting resin and a photocurable resin before curing, and examples thereof include an addition reaction type silicone resin, a condensation reaction type silicone resin, a modified silicone resin, and an epoxy resin. In addition, a solution obtained by hydrolytic polymerization of a solution containing an inorganic material, for example, a ceramic precursor polymer or a metal alkoxide by a sol-gel method can be used. These liquid media may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. In addition, an organic solvent can be contained in the liquid medium.

  The amount of the liquid medium used may be appropriately adjusted according to the application, etc., but in general, the weight ratio of the phosphor to the liquid medium of the present invention is usually 3% by weight or more, preferably 5% by weight or more, Moreover, it is 30 weight% or less normally, Preferably it is the range of 15 weight% or less. If the amount of the liquid medium is too small, light emission from the phosphor becomes too strong and the luminance may be lowered. If too much, the light emission from the phosphor becomes too weak and the luminance may be lowered.

  In addition to the phosphor of the present invention and the liquid medium, the phosphor-containing composition of the present invention may contain other optional components depending on its use and the like. Examples of other components include a diffusing agent, a thickener, a bulking agent, and an interference agent. Specifically, silica-based fine powder such as Aerosil, alumina and the like can be mentioned. In addition, these other components may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

[2. Light emitting device]
Next, the light emitting device of the present invention will be described. The light-emitting device of the present invention includes at least a first light-emitting body as an excitation light source and a second light-emitting body that emits visible light when irradiated with light from the first light-emitting body.

[2-1. First luminous body]
(First luminous body)
The 1st light-emitting body in the light-emitting device of this invention light-emits the light which excites the 2nd light-emitting body mentioned later. The light emission wavelength of the first light emitter is not particularly limited as long as it overlaps with the absorption wavelength of the second light emitter described later, and a light emitter having a wide light emission wavelength region can be used. Usually, an illuminant having an emission wavelength from the ultraviolet region to the blue region is used, and it is particularly preferable to use an illuminant having an emission wavelength from the near ultraviolet region to the blue region. As the specific value of the emission wavelength of the first illuminant, an illuminant having a peak emission wavelength of usually 200 nm or more, preferably 300 nm or more, more preferably 360 nm or more, and usually 500 nm or less, preferably 480 nm or less is used. Is done. In particular, a light emitter that emits light in the near ultraviolet region of 360 nm to 430 nm and a light emitter that emits light in the blue region of 430 nm to 480 nm are preferable. As the first light emitter, a semiconductor light emitting element is generally used. Specifically, a light emitting diode (hereinafter abbreviated as “LED” as appropriate) or a semiconductor laser diode (semiconductor laser diode). Hereinafter, it is abbreviated as “LD” where appropriate).

Among these, as the first light emitter, a GaN LED or LD using a GaN compound semiconductor is preferable. This is because GaN-based LEDs and LDs have significantly higher light emission output and external quantum efficiency than SiC-based LEDs that emit light in this region, and are extremely bright with very low power when combined with the phosphor. This is because light emission can be obtained. For example, for a current load of 20 mA, GaN-based LEDs and LDs usually have a light emission intensity 100 times or more that of SiC-based. GaN-based LEDs and LDs preferably have an Al _X Ga _Y N light emitting layer, a GaN light emitting layer, or an In _X Ga _Y N light emitting layer. Among the GaN-based LEDs, those having an In _X Ga _Y N light-emitting layer are particularly preferable because the light emission intensity is very strong, and in the GaN-based LED, the multiple quantum of the In _X Ga _Y N layer and the GaN layer is preferable. A well structure is particularly preferable because the emission intensity is very strong.

  In the above, the value of X + Y is usually a value in the range of 0.8 to 1.2. In the GaN-based LED, those in which the light emitting layer is doped with Zn or Si or those without a dopant are preferable for adjusting the light emission characteristics.

A GaN-based LED has these light-emitting layer, p-layer, n-layer, electrode, and substrate as basic components, and the light-emitting layer is an n-type and p-type Al _X Ga _Y N layer, GaN layer, or In _X Those having a hetero structure sandwiched between Ga _Y N layers and the like have high luminous efficiency, and those having a hetero structure having a quantum well structure further have high luminous efficiency and are more preferable.

[2-2. Second luminous body]
The second light emitter in the light emitting device of the present invention is a light emitter that emits visible light when irradiated with light from the first light emitter described above, and contains the phosphor of the present invention described above as the first phosphor. In addition, the second phosphor is appropriately contained in accordance with its use. Further, for example, the second light emitter is configured by dispersing the first and second phosphors in a sealing resin.

There is no particular limitation on the composition of the phosphor, _Y 2 _O 3 is a host _crystal, Zn 2 metal oxide represented by SiO ₄ and the _like, a metal nitride typified by Sr 2 _Si 5 _{N 8} such, Ca ₅ (PO ₄ ) ₃ Cl etc. and phosphates such as ZnS, SrS, CaS etc., Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, A combination of rare earth metal ions such as Tm and Yb and metal ions such as Ag, Cu, Au, Al, Mn, and Sb as activators or coactivators is preferred.

Preferred examples of the crystal matrix include sulfides such as (Zn, Cd) S, SrGa ₂ S ₄ , SrS, and ZnS, oxysulfides such as Y ₂ O ₂ S, and (Y, Gd) ₃ Al ₅ O. ₁₂ , YAlO ₃ , BaMgAl ₁₀ O ₁₇ , (Ba, Sr) (Mg, Mn) Al ₁₀ O ₁₇ , (Ba, Sr, Ca) (Mg, Zn, Mn) Al ₁₀ O ₁₇ , BaAl ₁₂ O ₁₉ , CeMgAl ₁₁ O ₁₉ , (Ba, Sr, Mg) O.Al ₂ O ₃ , BaAl ₂ Si ₂ O ₈ , SrAl ₂ O ₄ , Sr ₄ Al ₁₄ O ₂₅ , aluminate such as Y ₃ Al ₅ O ₁₂ , Y Silicates such as ₂ SiO ₅ and Zn ₂ SiO ₄ , oxides such as SnO ₂ and Y ₂ O ₃ , borates such as GdMgB ₅ O ₁₀ and (Y, Gd) BO ₃ , Ca ₁₀ (PO ₄ ) ₆ ( _{F, Cl) 2, (Sr} , Ca, Ba, g) ₁₀ (PO ₄₎ such as ₆ Cl _{2 halophosphate,} Sr ₂ P _{2 O 7,} can be cited (La, Ce) phosphate PO _4, etc. and the like.

  However, the crystal matrix and the activator element or coactivator element are not particularly limited in element composition, and can be partially replaced with elements of the same family, and the obtained phosphor is light in the near ultraviolet to visible region. Any material that absorbs and emits visible light can be used.

Specifically, the following phosphors can be used, but these are merely examples, and phosphors that can be used in the present invention are not limited to these. In the following examples, phosphors that differ only in part of the structure are omitted as appropriate. For example, “Y ₂ SiO ₅ : Ce ³⁺ ”, “Y ₂ SiO ₅ : Tb ³⁺ ” and “Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ ” are changed to “Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ ”, “ “La ₂ O ₂ S: Eu”, “Y ₂ O ₂ S: Eu” and “(La, Y) ₂ O ₂ S: Eu” are collectively shown as “(La, Y) ₂ O ₂ S: Eu”. ing. Omitted parts are shown separated by commas (,).

[2-2-1. First phosphor]
The second light emitter in the light emitting device of the present invention contains at least the above-described phosphor of the present invention as the first phosphor. Any one of the phosphors of the present invention may be used alone, or two or more thereof may be used in any combination and ratio. In addition to the phosphor of the present invention, a phosphor that emits the same color fluorescence as the phosphor of the present invention (same color combined phosphor) may be used as the first phosphor. Usually, since the phosphor of the present invention is an orange or red phosphor, an orange or red phosphor can be used together with the phosphor of the present invention as the first phosphor.

  As the first phosphor, orange to red phosphors that can be used in combination with the phosphor of the present invention are exemplified below. In addition, these may be used individually by 1 type and may use 2 or more types together by arbitrary combinations and ratios.

Examples of the orange to red phosphor that can be used in combination with the phosphor of the present invention include, for example, broken particles having a red fracture surface and emit light in the red region (Mg, Ca, Sr, Ba) ₂ Si ₅ N ₈ : A europium-activated alkaline earth silicon nitride-based phosphor represented by Eu, which is composed of growth particles having a substantially spherical shape as a regular crystal growth shape, and emits light in a red region (Y, La, Gd, Lu ) ₂ O ₂ S: Europium activated rare earth oxychalcogenide phosphor represented by Eu.

  Furthermore, the oxynitride and / or acid containing at least one element selected from the group consisting of Ti, Zr, Hf, Nb, Ta, W, and Mo described in JP-A-2004-300247 A phosphor containing a sulfide and containing an oxynitride having an alpha sialon structure in which a part or all of the Al element is substituted with a Ga element can also be used in this embodiment. These are phosphors containing oxynitride and / or oxysulfide.

In addition, examples of red phosphors include Eu-activated oxysulfide phosphors such as (La, Y) ₂ O ₂ S: Eu, Y (V, P) O ₄ : Eu, Y ₂ O ₃ : Eu, and the like. Eu-activated oxide phosphor, (Ba, Sr, Ca, Mg) 2 SiO 4: Eu, Mn, (Ba, Mg) 2 SiO 4: Eu, Eu such as Mn, Mn-activated silicate phosphor, Eu-activated tungstate phosphors such as LiW ₂ O ₈ : Eu, LiW ₂ O ₈ : Eu, Sm, Eu ₂ W ₂ O ₉ , Eu ₂ W ₂ O ₉ : Nb, Eu ₂ W ₂ O ₉ : Sm (Ca, Sr) S: Eu activated sulfide phosphor such as Eu, YAlO ₃ : Eu activated aluminate phosphor such as Eu, LiY ₉ (SiO ₄ ) ₆ O ₂ : Eu, Ca ₂ Y _{8 (SiO 4) 6 O 2:} Eu -activated silicate phosphors such as _{Eu, (Y, Gd) 3} Al 5 O 12: Ce, (Tb _{Gd) 3 Al 5 O 12:} Ce -activated aluminate phosphor such as Ce, (Ca, Sr, Ba ) 2 Si 5 N 8: Eu, (Mg, Ca, Sr, Ba) SiN 2: Eu, ( Mg, Ca, Sr, Ba) AlSiN ₃ : Eu activated nitride phosphor such as Eu, (Mg, Ca, Sr, Ba) AlSiN ₃ : Ce activated nitride phosphor such as Ce, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, Mn-activated halophosphate phosphor such as Eu, Mn, (Ba ₃ Mg) Si ₂ O ₈ : Eu, Mn, (Ba, Sr, Ca, Mg) ₃ (Zn, Mg) Si ₂ O ₈ : Eu, Mn activated silicate phosphor such as Eu, Mn, 3.5 Mn activated germanate fluorescence such as 3.5 MgO · 0.5 MgF ₂ · GeO ₂ : Mn body, Eu Tsukekatsusan nitride phosphor such as Eu-activated α-sialon, (Gd, Y, Lu, La) 2 O : Eu, Eu Bi, etc., Bi-activated oxide phosphor, (Gd, Y, Lu, La) 2 O 2 S: Eu, Eu Bi, etc., Bi Tsukekatsusan sulfide phosphor, (Gd, Y , Lu, La) VO ₄ : Eu, Bi-activated vanadate phosphors such as Eu and Bi, SrY ₂ S ₄ : Eu and Ce-activated sulfide phosphors such as Eu and Ce, CaLa ₂ S ₄ : Ce Ce-activated sulfide phosphors such as (Ba, Sr, Ca) MgP ₂ O ₇ : Eu, Mn, (Sr, Ca, Ba, Mg, Zn) ₂ P ₂ O ₇ : Eu such as Eu, Mn, Mn-activated phosphate phosphor, (Y, Lu) ₂ WO ₆ : Eu, Mo-activated tungstate phosphor such as Eu, Mo, (Ba, Sr, Ca) _x Si _y N _z : Eu, Ce (Where x, y, and z are integers of 1 or more) Eu, Ce activated nitride phosphor, (Ca, Sr, Ba, Mg) ₁₀ (PO _{4) 6 (F, Cl,} Br, OH): Eu, Eu such as Mn, Mn-activated halophosphate phosphor, ((Y, Lu, Gd , Tb) 1-x Sc x Ce y) 2 (Ca , Mg) _1-r (Mg, Zn) _{2 + r} Si _z-q Ge _q O _{12 + δ} or other Ce-activated silicate phosphors can also be used.

  As the red phosphor, β-diketonate, β-diketone, aromatic carboxylic acid, or a red organic phosphor composed of a rare earth element ion complex having an anion such as Bronsted acid as a ligand, a perylene pigment (for example, Dibenzo {[f, f ′]-4,4 ′, 7,7′-tetraphenyl} diindeno [1,2,3-cd: 1 ′, 2 ′, 3′-lm] perylene), anthraquinone pigment, Lake pigments, azo pigments, quinacridone pigments, anthracene pigments, isoindoline pigments, isoindolinone pigments, phthalocyanine pigments, triphenylmethane basic dyes, indanthrone pigments, indophenol pigments, It is also possible to use a cyanine pigment or a dioxazine pigment.

Among the red phosphors, those having a peak wavelength in the range of 580 nm or more, preferably 590 nm or more, and 620 nm or less, preferably 610 nm or less can be suitably used as the orange phosphor. Examples of such orange phosphors include (Sr, Mg) ₃ (PO ₄ ) ₂ : Sn ^{2+ and the} like.

[2-2-2. Second phosphor]
The second light emitter in the light emitting device of the present invention may contain a phosphor (that is, a second phosphor) in addition to the first phosphor described above, depending on the application. The second phosphor is a phosphor having an emission wavelength different from that of the first phosphor. Usually, since these second phosphors are used to adjust the color tone of light emitted from the second light emitter, the second phosphor emits fluorescence having a color different from that of the first phosphor. Often phosphors are used. As described above, since an orange or red phosphor is usually used as the first phosphor, examples of the second phosphor include orange to red phosphors such as a green phosphor, a blue phosphor, and a yellow phosphor. Other phosphors are used.

(Green phosphor)
When a green phosphor is used as the second phosphor, any red phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the green phosphor is usually in the wavelength range of 490 nm or more, preferably 510 nm or more, more preferably 515 nm or more, and usually 560 nm or less, preferably 540 nm or less, more preferably 535 nm or less. Is preferred.

As such a green phosphor, for example, europium activation represented by (Mg, Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu that is composed of fractured particles having a fracture surface and emits light in the green region. An alkaline earth silicon oxynitride phosphor, composed of fractured particles having a fracture surface, emits green light (Ba, Ca, Sr, Mg) ₂ SiO ₄ : europium activated alkaline earth expressed by Eu Silicate phosphors and the like.

In addition, as the green phosphor, Eu-activated aluminate phosphor such as Sr ₄ Al ₁₄ O ₂₅ : Eu, (Ba, Sr, Ca) Al ₂ O ₄ : Eu, (Sr, Ba) Al ₂ Si ₂ O ₈ : Eu, (Ba, Mg) ₂ SiO ₄ : Eu, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ba, Sr, Ca) ₂ (Mg, Zn) Si ₂ O ₇ : Eu, (Ba, Ca, Sr, Mg) ₉ (Sc, Y, Lu, Gd) ₂ (Si, Ge) ₆ O ₂₄ : Eu-activated silicate phosphor such as Eu, Y ₂ SiO ₅ : Ce, Ce, Tb-activated silicate phosphors such as Tb, Sr ₂ P ₂ O ₇ —Sr ₂ B ₂ O ₅ : Eu-activated borate phosphate phosphors such as Eu, Sr ₂ Si ₃ O ₈ -2SrCl ₂ : Eu-activated halo silicate phosphor such as Eu, Zn ₂ SiO _4: Mn-activated silicate phosphors such as Mn, _{eMgAl 11 O 19: Tb, Y} 3 Al 5 O 12: Tb -activated aluminate phosphors such as _{Tb, Ca 2 Y 8 (SiO} 4) 6 O 2: Tb, La 3 Ga 5 SiO 14: and Tb such Tb-activated silicate phosphor, (Sr, Ba, Ca) Ga ₂ S ₄ : Eu, Tb, Sm-activated thiogallate phosphor such as Eu, Tb, Sm, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce , (Y, Ga, Tb, La, Sm, Pr, Lu) ₃ (Al, Ga) ₅ O ₁₂ : Ce-activated aluminate phosphor such as Ce, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, Ca ₃ (Sc, Mg, Na, Li) ₂ Si ₃ O ₁₂ : Ce-activated silicate phosphor such as Ce, CaSc ₂ O ₄ : Ce-activated oxide phosphor such as Ce, SrSi ₂ O ₂ N ₂ : Eu, (Sr, Ba, Ca) Si ₂ O ₂ N ₂ : Eu, Eu-activated β Eu activated oxynitride phosphors such as sialon and Eu activated α sialon, BaMgAl ₁₀ O ₁₇ : Eu such as Eu and Mn, Mn activated aluminate phosphor, SrAl ₂ O ₄ : Eu activated such as Eu Aluminate phosphor, (La, Gd, Y) ₂ O ₂ S: Tb-activated oxysulfide phosphor such as Tb, LaPO ₄ : Ce, Tb-activated phosphate phosphor such as Ce, Tb, ZnS : Cu, Al, ZnS: sulfide phosphors such as Cu, Au, Al, (Y, Ga, Lu, Sc, La) BO ₃ : Ce, Tb, Na ₂ Gd ₂ B ₂ O ₇ : Ce, Tb, (Ba, Sr) ₂ (Ca, Mg, Zn) B ₂ O ₆ : Ce, Tb activated borate phosphors such as K, Ce, Tb, Ca ₈ Mg (SiO ₄ ) ₄ Cl ₂ : Eu, Mn, etc. of Eu, Mn-activated halo silicate phosphor, (Sr, Ca, Ba) (Al, Ga, in) 2 _4: Eu activated thioaluminate phosphor or thiogallate phosphor such as _{Eu, (Ca, Sr) 8} (Mg, Zn) (SiO 4) 4 Cl 2: Eu, such as Mn Eu, Mn-activated halo silicate _{phosphor, MSi 2 O 2 N 2:} Eu, M 3 Si 6 O 9 N 4: Eu, M 2 Si 7 O 10 N 4: Eu ( where, M represents an alkaline earth metal element. It is also possible to use Eu-activated oxynitride phosphors such as

  In addition, as the green phosphor, it is also possible to use a pyridine-phthalimide condensed derivative, a benzoxazinone-based, a quinazolinone-based, a coumarin-based, a quinophthalone-based, a naltalimide-based fluorescent pigment, or an organic phosphor such as a terbium complex. is there.

(Blue phosphor)
When a blue phosphor is used as the second phosphor, any blue phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the blue phosphor is usually in the wavelength range of 420 nm or more, preferably 430 nm or more, more preferably 440 nm or more, and usually 490 nm or less, preferably 470 nm or less, more preferably 460 nm or less. Is preferred.

As such a blue phosphor, europium-activated barium magnesium aluminate represented by BaMgAl ₁₀ O ₁₇ : Eu, which is composed of growing particles having a substantially hexagonal shape as a regular crystal growth shape and emits light in a blue region. System phosphor, composed of growing particles having a nearly spherical shape as a regular crystal growth shape, and emits light in the blue region, with europium represented by (Ca, Sr, Ba) ₅ (PO ₄ ) ₃ Cl: Eu An active calcium halophosphate phosphor is composed of growing particles having a substantially cubic shape as a regular crystal growth shape, and emits light in a blue region (Ca, Sr, Ba) ₂ B ₅ O ₉ Cl: represented by Eu Europium-activated alkaline earth chloroborate phosphor, composed of fractured particles having a fracture surface, and emits light in the blue-green region (Sr _{Ca, Ba) Al 2 O 4} : Eu or _{(Sr, Ca, Ba) 4} Al 14 O 25: activated alkaline earth with europium aluminate-based phosphor such as represented by the Eu and the like.

In addition, as the blue phosphor, Sn-activated phosphate phosphors such as Sr ₂ P ₂ O ₇ : Sn, Sr ₄ Al ₁₄ O ₂₅ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, BaAl ₈ O ₁₃ : Eu-activated aluminate phosphors such as Eu, Ce-activated thiogallate phosphors such as SrGa ₂ S ₄ : Ce, CaGa ₂ S ₄ : Ce, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu activated aluminate phosphor such as Eu, Tb, Sm, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, Mn activated aluminate phosphor such as Eu, Mn, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, (Ba, Sr, Ca) ₅ (PO ₄ ) ₃ (Cl, F, Br, OH): Eu activation such as Eu, Mn, Sb halophosphate phosphor, BaAl _{Si 2 O 8: Eu, (} Sr, Ba) 3 MgSi 2 O 8: Eu -activated silicate phosphors such as _{Eu, Sr 2 P 2 O 7} : Eu -activated phosphate phosphor such as Eu, ZnS: Sulfide phosphors such as Ag, ZnS: Ag, Al, etc. Y ₂ SiO ₅ : Ce-activated silicate phosphors such as Ce, tungstate phosphors such as CaWO ₄ , (Ba, Sr, Ca) BPO ₅ : Eu, Mn, (Sr, Ca ) 10 (PO 4) 6 · nB 2 O 3: Eu, 2SrO · 0.84P 2 O 5 · 0.16B 2 O 3: Eu such as Eu, Mn-activated borate phosphate It is also possible to use a salt phosphor, an Eu-activated halosilicate phosphor such as Sr ₂ Si ₃ O ₈ .2SrCl ₂ : Eu, or the like.

  In addition, as the blue phosphor, for example, naphthalic acid imide-based, benzoxazole-based, styryl-based, coumarin-based, pyrazoline-based, triazole-based compound fluorescent dyes, thulium complexes and other organic phosphors can be used. .

(Yellow phosphor)
When a yellow phosphor is used as the second phosphor, any yellow phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the yellow phosphor is usually in the wavelength range of 530 nm or more, preferably 540 nm or more, more preferably 550 nm or more, and usually 620 nm or less, preferably 600 nm or less, more preferably 580 nm or less. Is preferred.

Examples of such yellow phosphors include various oxide-based, nitride-based, oxynitride-based, sulfide-based, and oxysulfide-based phosphors.
In particular, RE ₃ M ₅ O ₁₂ : Ce (where RE represents at least one element selected from the group consisting of Y, Tb, Gd, Lu, and Sm, and M represents Al, Ga, and Sc. And M ^a ₃ M ^b ₂ M ^c ₃ O ₁₂ : Ce (where M ^a is a divalent metal element and M ^b is a trivalent metal element) , ^{M c} is garnet phosphor having a garnet structure represented by the representative) like a tetravalent metallic ^{_{element, AE 2 M d O 4:}} . Eu ( where, AE is, Ba, Sr, Ca, Mg , And at least one element selected from the group consisting of Zn, and M ^d represents Si and / or Ge)), etc., and constituent elements of the phosphors of these systems An oxynitride phosphor obtained by substituting a part of oxygen in nitrogen, EAlSiN _3: Ce (., Where, AE is, Ba, Sr, Ca, Mg and represents at least one element selected from the group consisting of Zn) of the nitride-based fluorescent material or the like having a CaAlSiN ₃ structure, such as Ce And the phosphor activated in step (b).

In addition, examples of yellow phosphors include sulfide-based fluorescence such as CaGa ₂ S ₄ : Eu, (Ca, Sr) Ga ₂ S ₄ : Eu, (Ca, Sr) (Ga, Al) ₂ S ₄ : Eu. It is also possible to use a phosphor activated with Eu such as an oxynitride phosphor having a SiAlON structure such as a body, Cax (Si, Al) ₁₂ (O, N) ₁₆ : Eu.

  Examples of the yellow phosphor include fluorescent dyes such as brilliantsulfoflavine FF (Colour Index Number 56205), basic yellow HG (Colour Index Number 46040), eosine (Colour Index Number 45380), rhodamine 6G (Colour Index Number 45160), etc. It is also possible to use.

  In addition, as a 2nd fluorescent substance, 1 type of fluorescent substance may be used independently, and 2 or more types of fluorescent substance may be used together by arbitrary combinations and a ratio. Further, the ratio between the first phosphor and the second phosphor is also arbitrary as long as the effects of the present invention are not significantly impaired. Therefore, the usage amount of the second phosphor, the combination of phosphors used as the second phosphor, and the ratio thereof may be arbitrarily set according to the use of the light emitting device.

[2-2-3. Physical properties of second phosphor]
The weight median diameter of the second phosphor used in the light emitting device of the present invention is usually in the range of 10 μm or more, especially 15 μm or more, and usually 30 μm or less, especially 20 μm or less. If the weight median diameter is too small, the luminance is lowered and the phosphor particles tend to aggregate, which is not preferable. On the other hand, when the weight median diameter is too large, there is a tendency that uneven coating or blockage of a dispenser or the like occurs, which is not preferable.

[2-2-4. Selection of second phosphor]
In the light emitting device of the present invention, the presence / absence and type of the second phosphor (red phosphor, blue phosphor, green phosphor, etc.) described above may be appropriately selected according to the use of the light emitting device. . For example, when the light emitting device of the present invention is configured as an orange or red light emitting device, only the first phosphor (orange or red phosphor) may be used, and the second phosphor is usually used. Is unnecessary.

  On the other hand, when the light-emitting device of the present invention is configured as a light-emitting device that emits white light, the first light-emitting body, the first phosphor (orange or red phosphor), and a desired white light are obtained. What is necessary is just to combine a 2nd fluorescent substance appropriately. Specifically, as an example of a preferable combination of the first phosphor, the first phosphor, and the second phosphor when the light-emitting device of the present invention is configured as a white light-emitting device, for example, The following combinations (i) to (iv) are mentioned.

(I) A blue phosphor (such as a blue LED) is used as the first phosphor, a red phosphor (such as the phosphor of the present invention) is used as the first phosphor, and green fluorescence is used as the second phosphor. Use the body.

(Ii) A near ultraviolet light emitter (near ultraviolet LED or the like) is used as the first light emitter, a red phosphor (such as the phosphor of the present invention) is used as the first phosphor, and the second phosphor is used as the second phosphor. A blue phosphor and a green phosphor are used in combination.

(Iii) A blue phosphor (such as a blue LED) is used as the first phosphor, an orange phosphor (such as the phosphor of the present invention) is used as the first phosphor, and green fluorescence is used as the second phosphor. Use the body.
(Iv) A near ultraviolet light emitter (near ultraviolet LED or the like) is used as the first light emitter, an orange phosphor (such as the phosphor of the present invention) is used as the first phosphor, and the second phosphor is used. A blue phosphor and a green phosphor are used in combination.

The combination of phosphors as described above will be described in more detail.
In the present invention, a light emitting device using a semiconductor light emitting element and a phosphor in a combination shown below is preferable.
In the table below, phosphors that differ only in part of the structure are omitted as appropriate. For example, “Y ₂ SiO ₅ : Ce ³⁺ ”, “Y ₂ SiO ₅ : Tb ³⁺ ” and “Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ ” are indicated as “Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ ”, “La ₂ O ₂ S: Eu”, “Y ₂ O ₂ S: Eu” and “(La, Y) ₂ O ₂ S: Eu” are combined with “(La, Y) ₂ O ₂ S: Eu”. Show. In this case, the total of the elements in () is 1 mol. Omitted parts are shown separated by commas (,).

  Among these combinations, a light emitting device using a semiconductor light emitting element and a phosphor in the following combinations is particularly preferable.

  In addition, the phosphor of the present invention is mixed with other phosphors (here, mixing does not necessarily mean that the phosphors are necessarily mixed with each other, but means that different phosphors are combined). Can be used. In particular, when phosphors are mixed in the combinations described in Tables 3a to 3n, a preferable phosphor mixture is obtained. In addition, there is no restriction | limiting in particular in the kind of fluorescent substance to mix, and its ratio.

[2-2-4. Sealing material]
The second light emitter is configured, for example, by dispersing a first phosphor and a second phosphor used as necessary in a sealing material.
Examples of the sealing material include thermoplastic resins, thermosetting resins, and photocurable resins. Specifically, methacrylic resin such as methyl polymethacrylate; styrene resin such as polystyrene and styrene-acrylonitrile copolymer; polycarbonate resin; polyester resin; phenoxy resin; butyral resin; polyvinyl alcohol; ethyl cellulose, cellulose acetate, cellulose Cellulose resins such as acetate butyrate; epoxy resins; phenol resins; silicone resins and the like. Further, an inorganic material such as a siloxane bond formed by solidifying a solution obtained by hydrolytic polymerization of a solution containing an inorganic material such as a metal alkoxide, ceramic precursor polymer or metal alkoxide by a sol-gel method, or a combination thereof. An inorganic material can be used.

  Among these, from the viewpoint of heat resistance, ultraviolet resistance (UV) resistance, etc., a solution obtained by hydrolyzing a solution containing a silicone resin, a metal alkoxide, a ceramic precursor polymer, or a metal alkoxide by a sol-gel method, or these An inorganic material obtained by solidifying these combinations, for example, an inorganic material having a siloxane bond is preferable.

Among these, when used with the phosphor of the present invention, it is preferable to use a silicone resin or a silicone-based material, and it is more preferable to use a silicone resin.
Examples of the silicone resin include addition reaction type silicone resins and condensation reaction type silicone resins. Among these, condensation reaction type silicone resins containing a phenyl group are preferable. Further, it is more preferable that the silicone resin or the silicone-based material has a refractive index of 1.45 or more.

Moreover, among such sealing materials, a silicone material and a silicone resin having one or more of the following features <1> to <3> are particularly preferable.
<1> The solid Si-nuclear magnetic resonance (NMR) spectrum has at least one of the following peaks (a) and / or (b).
(A) The peak top position is in the region of chemical shift −40 ppm or more and 0 ppm or less, and the peak half-width is 0.3 ppm or more and 3.0 ppm or less.
(B) A peak whose peak top position is in a region where the chemical shift is −80 ppm or more and less than −40 ppm, and the half width of the peak is 0.3 ppm or more and 5.0 ppm or less.
<2> The silicon content is 20% by weight or more.
<3> The silanol content is 0.1% by weight or more and 10% by weight or less.

  In the present invention, among the above features <1> to <3>, a silicone material or a silicone resin having the feature <2> is preferable. More preferably, a silicone material or a silicone resin having the above characteristics <1> and <2> is preferable. Particularly preferably, a silicone material or a silicone resin having all of the above characteristics <1> to <3> is preferable.

  Hereinafter, these features <1> to <3> will be described. Hereinafter, the silicone material having the above characteristics <1> to <3> is referred to as “silicone material used in the present invention”.

(Solid Si-NMR spectrum)
A compound containing silicon as a main component is represented by the following formula: SiO ₂ · nH ₂ O. Structurally, oxygen atoms O are bonded to each vertex of a tetrahedron of silicon atoms Si, and these oxygens It has a structure in which silicon atom Si is further bonded to atom O and spreads in a net shape. The schematic diagram shown below represents the Si—O net structure, ignoring the tetrahedral structure, but in the repeating unit of Si—O—Si—O—, Some of them are substituted with other members (for example, —H, —CH _3, etc.), and when attention is paid to one silicon atom Si, as shown in FIG. silicon atoms having Si ^(Q 4), a silicon atom Si ^{(Q 3)} having three -OSi as shown in the schematic diagram (B) or the like is present. Then, in the solid-state Si-NMR measurement, peaks based on each silicon atom Si above is sequentially referred to ^{Q 4} peak, ^{Q 3} peak, and ....

These silicon atoms having four bonded oxygen atoms are generally referred to as Q sites. In the present invention, each peak of Q ^{0 to} Q ⁴ derived from the Q site is referred to as a Q ⁿ peak group. ^{Q n} peak group of a silica film containing no organic substituents, is observed as multimodal peaks are continuous in areas of normal chemical shift -80ppm~-130ppm.

In contrast, silicon atoms to which three oxygen atoms are bonded and other atoms (usually carbon) are bonded together are generally referred to as T sites. The peak derived from the T site is observed as each peak of T ^{0 to} T ³ as in the case of the Q site. In the present invention, each peak derived from the T site is referred to as a ^Tn peak group. The T ⁿ peak group is generally observed as a multimodal peak continuous in the region on the higher magnetic field side (usually chemical shift of −80 ppm to −40 ppm) than the Q ⁿ peak group.

Furthermore, a silicon atom to which two oxygen atoms are bonded and two other atoms (usually carbon) are bonded is generally referred to as a D site. Similarly to the peak group derived from the Q site and the T site, the peak derived from the D site is observed as each peak of D ^{0 to} D ⁿ (referred to as a D ⁿ peak group), and the peak of Q ⁿ or T ⁿ is observed. Further, it is observed as a multimodal peak in a region on the high magnetic field side (normally, a region with a chemical shift of 0 ppm to −40 ppm). The ratio of the area of each peak group of D ⁿ , T ⁿ , and Q ⁿ is equal to the molar ratio of silicon atoms in the environment corresponding to each peak group. In terms of the molar amount, the total area of the D ⁿ peak group and the T ⁿ peak group usually corresponds to the molar amount of all silicon directly bonded to the carbon atom.

Bond When measuring the solid Si-NMR spectrum of a silicone-based material used in the present invention, the D ⁿ peak group and T ⁿ peak group originating from silicon atoms in which carbon atoms directly bonded organic group, and the carbon atom of an organic group ^Qn peaks derived from silicon atoms not appearing in different regions. Among these peaks, a peak of less than −80 ppm corresponds to the Q ⁿ peak as described above, and a peak of −80 ppm or more corresponds to the D ⁿ and T ⁿ peaks. In the silicone material of the present invention, the Q ⁿ peak is not essential, but at least one, preferably a plurality of peaks are observed in the D ⁿ and T ⁿ peak regions.

  Further, in the silicone material used in the present invention, the half width of the peak observed in the region of −80 ppm or more is smaller (narrower) than the half width range of the silicone material known so far by the sol-gel method. It is characterized by that.

When organized by chemical shifts, in a silicone-based material used in the present invention, the half width of ^{T n} peak group the position of the peak top is observed less than -80 ppm -40 ppm is usually 5.0ppm or less, preferably 4 0.0 ppm or less, and usually 0.3 ppm or more, preferably 0.4 ppm or more.

Similarly, the half width of the D ⁿ peak group observed at the peak top position of −40 ppm or more and 0 ppm or less is generally smaller than that of the T ⁿ peak group because the molecular motion constraint is small, and usually 3.0 ppm or less. , Preferably 2.0 ppm or less, and usually in the range of 0.3 ppm or more.

  If the half-value width of the peak observed in the chemical shift region is larger than the above range, the molecular motion is constrained and the strain is large, and cracking is likely to occur, resulting in a member having poor heat resistance and weather resistance. There is. For example, in the case where a large amount of tetrafunctional silane is used, or in the state where rapid drying is performed in the drying process and a large internal stress is stored, the full width at half maximum is larger than the above range.

  In addition, when the half width of the peak is smaller than the above range, Si atoms in the environment are not involved in the siloxane crosslinking, and the trifunctional silane remains in an uncrosslinked state and is formed mainly of siloxane bonds. There is a risk of becoming a member that is inferior in heat resistance and weather resistance to a substance.

  The composition of the silicone material used in the present invention is limited to the case where the crosslinking in the system is mainly formed by inorganic components including silica. That is, even in the case of a silicone material containing a small amount of Si component in a large amount of organic component, even if the peak in the above-described half-value range is observed at -80 ppm or more, good heat resistance / light resistance and coating performance cannot be obtained. .

  The value of the chemical shift of the silicone material used in the present invention can be calculated based on the results of solid Si-NMR measurement using the following method, for example. In addition, analysis of measurement data (half-width or silanol amount analysis) is performed by a method of dividing and extracting each peak by, for example, waveform separation analysis using a Gaussian function or a Lorentz function.

(Solid Si-NMR spectrum measurement and silanol content calculation)
When performing a solid Si-NMR spectrum about a silicone type material, a solid Si-NMR spectrum measurement and waveform separation analysis are performed on condition of the following. Further, from the obtained waveform data, the half width of each peak is determined for the silicone material. In addition, from the ratio of the peak area derived from silanol to the total peak area, the ratio (%) of silicon atoms that are silanols in all silicon atoms is obtained, and the silanol content is determined by comparing with the silicon content analyzed separately. Ask.

{Device conditions}
Apparatus: Chemmagnetics Infinity CMX-400 Nuclear magnetic resonance spectrometer
²⁹ Si resonance frequency: 79.436 MHz
Probe: 7.5mmφCP / MAS probe
Measurement temperature: room temperature
Sample rotation speed: 4 kHz
Measurement method: Single pulse method
¹ H decoupling frequency: 50 kHz
²⁹ Si flip angle: 90 °
²⁹ Si 90 ° pulse width: 5.0μs
Repeat time: 600s
Integration count: 128 times
Observation width: 30 kHz
Broadening factor: 20Hz

{Data processing method}
For silicone-based materials, 512 points are taken as measurement data, zero-filled to 8192 points, and Fourier transformed.

{Waveform separation analysis method}
For each peak of the spectrum after Fourier transform, optimization calculation is performed by a non-linear least square method with the center position, height, and half width of the peak shape created by Lorentz waveform and Gaussian waveform or a mixture of both as variable parameters.
In addition, identification of a peak is AIChE Journal, 44 (5), p. Refer to 1141, 1998, etc.

(Silicon content)
The silicone material used in the present invention has a silicon content of 20% by weight or more (feature <2>).
The basic skeleton of the conventional silicone-based material is an organic resin such as an epoxy resin having carbon-carbon and carbon-oxygen bonds as the basic skeleton, whereas the basic skeleton of the silicone-based material of the present invention is glass (silicate). It is the same inorganic siloxane bond as glass). As is apparent from the chemical bond comparison table shown in Table 1 below, this siloxane bond has the following characteristics excellent as a silicone material.
(I) Light resistance is good because of its high binding energy and resistance to thermal and photolysis.
(II) It is slightly polarized electrically.
(III) The degree of freedom of the chain structure is large, a structure with high flexibility is possible, and the chain structure can freely rotate around the siloxane chain.
(IV) The degree of oxidation is large and no further oxidation occurs.
(V) Excellent electrical insulation.

  Because of these characteristics, silicone-based silicone materials that are formed with a skeleton in which siloxane bonds are three-dimensionally bonded with a high degree of crosslinking are close to inorganic materials such as glass or rock, and have a high heat resistance and light resistance. Can be understood. In particular, a silicone-based material having a methyl group as a substituent has no absorption in the ultraviolet region, so that photolysis hardly occurs and has excellent light resistance.

As described above, the silicon content of the silicone-based material used in the present invention is 20% by weight or more, preferably 25% by weight or more, and more preferably 30% by weight or more. On the other hand, the upper limit is usually in the range of 47% by weight or less because the silicon content of the glass composed solely of SiO ₂ is 47% by weight.

  The silicon content of the silicone material is calculated based on the result of inductively coupled plasma spectrometry (hereinafter abbreviated as “ICP” where appropriate) using, for example, the following method. be able to.

{Measurement of silicon content}
A single cured material of silicone material is pulverized to about 100 μm, and baked in a platinum crucible in the air at 450 ° C. for 1 hour, then at 750 ° C. for 1 hour, and at 950 ° C. for 1.5 hours. After removing the residue, add 10 times or more amount of sodium carbonate to a small amount of the obtained residue, heat with a burner to melt, cool this, add demineralized water, and further adjust the pH to neutral with hydrochloric acid. The volume is adjusted to about several ppm as silicon, and ICP analysis is performed.

(Silanol content)
The silicone material used in the present invention has a silanol content of usually 0.1% by weight or more, preferably 0.3% by weight or more, and usually 10% by weight or less, preferably 8% by weight or less, more preferably The range is 5% by weight or less (feature <3>). Since the silicone material used in the present invention has a low silanol content, there is little change over time, excellent long-term performance stability, and excellent performance with low moisture absorption and moisture permeability. However, since a member containing no silanol is inferior in adhesion, there exists an optimum range for the silanol content as described above.

  In addition, the silanol content rate of a silicone type material performs solid Si-NMR spectrum measurement, for example using the method demonstrated in (Solid Si-NMR spectrum measurement and calculation of silanol content rate) of (Solid Si-NMR spectrum), From the ratio of the peak area derived from silanol to the total peak area, the ratio (%) of silicon atoms that are silanols in all silicon atoms can be obtained and compared with the silicon content analyzed separately.

  Further, since the silicone material used in the present invention contains an appropriate amount of silanol, silanol is hydrogen bonded to the polar portion present on the device surface, and adhesion is exhibited. Examples of the polar part include a hydroxyl group and a metalloxane-bonded oxygen.

  In addition, the silicone material used in the present invention forms a covalent bond by dehydration condensation with the hydroxyl group on the device surface by heating in the presence of an appropriate catalyst, and expresses stronger adhesion. Can do.

On the other hand, if there is too much silanol, the inside of the system will thicken and it will be difficult to apply, or it will become highly active and solidify before the light boiling component volatilizes by heating, resulting in increased foaming and internal stress. This may cause cracks and the like.
(Measured hardness value)
The silicone material used in the present invention preferably exhibits an elastomeric shape. Specifically, the hardness measurement value (Shore A) by durometer type A is usually 5 or more, preferably 7 or more, more preferably 10 or more, and usually 90 or less, preferably 80 or less, more preferably 70 or less. Yes (feature <4>). By having a hardness measurement value in the above range, it is possible to obtain an advantage that cracks are hardly generated and that reflow resistance and temperature cycle resistance are excellent.

  The hardness measured value (Shore A) can be measured by the method described in JIS K6253. Specifically, the measurement can be performed using an A-type rubber hardness meter manufactured by Furusato Seiki Seisakusho. In addition, reflow refers to a soldering method in which a solder paste is printed on a substrate, a component is mounted thereon, and heated and joined. The reflow resistance refers to a property that can withstand a thermal shock of a maximum temperature of 260 ° C. for 10 seconds.

(Other additives)
In the silicone material used in the present invention, in order to adjust the refractive index of the sealing member, a metal element capable of providing a metal oxide having a high refractive index can be present in the sealing member. Examples of metal elements that give a metal oxide having a high refractive index include Si, Al, Zr, Ti, Y, Nb, and B. These metal elements may be used alone or in combination of two or more in any combination and ratio.

The presence form of such a metal element is not particularly limited as long as the transparency of the sealing member is not impaired. For example, even if a uniform glass layer is formed as a metalloxane bond, the metal element is present in a particulate form in the sealing member. It may be. When present in the form of particles, the structure inside the particles may be either amorphous or crystalline, but is preferably a crystalline structure in order to provide a high refractive index. Further, the particle diameter is usually not more than the emission wavelength of the semiconductor light emitting device, preferably not more than 100 nm, more preferably not more than 50 nm, particularly preferably not more than 30 nm so as not to impair the transparency of the sealing member. For example, by adding particles of silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, yttrium oxide, niobium oxide, etc. to the silicone material, the above metal element can be present in the sealing member in the form of particles. it can.
The silicone material used in the present invention may further contain known additives such as a diffusing agent, a filler, a viscosity modifier, and an ultraviolet absorber.

  Specific examples of the silicone material used in the present invention include the silicone materials described in Japanese Patent Application No. 2006-176468.

[2-3. Configuration of light emitting device]
The other configurations of the light emitting device of the present invention are not particularly limited as long as the first light emitting body and the second light emitting body described above are provided. Usually, the first light emitting body described above is formed on an appropriate frame. And a second light emitter. At this time, the second light emitter is excited by the light emission of the first light emitter (that is, the first and second phosphors are excited) to emit light, and the first light emitter emits light. And / or it arrange | positions so that light emission of a 2nd light-emitting body may be taken out outside. In this case, the first phosphor and the second phosphor are not necessarily mixed in the same layer. For example, the second phosphor is contained on the layer containing the first phosphor. For example, the phosphor may be contained in a separate layer for each color development of the phosphor, such as by stacking layers.

  In the light emitting device of the present invention, members other than the first light emitter, the second light emitter, and the frame described above may be used. Examples thereof include [2-2-4. Examples thereof include the sealing materials described in “Sealing Material”. As a specific example, the sealing material is used for the purpose of dispersing the second phosphor in the light emitting device, or for the purpose of bonding the first light emitter, the second light emitter and the frame. be able to.

[2-4. Embodiment of Light Emitting Device]
Hereinafter, the light-emitting device of the present invention will be described in more detail with reference to specific embodiments. However, the present invention is not limited to the following embodiments, and does not depart from the gist of the present invention. It can be implemented with arbitrary modifications.

  FIG. 1 a is a diagram schematically showing a configuration of a light emitting device according to an embodiment of the present invention. The light emitting device 1 of the present embodiment absorbs a part of light emitted from the frame 2, a blue LED (first light emitter) 3 that is a light source, and the blue LED 3, and emits light having a wavelength different from that. It comprises a phosphor-containing part (second light emitter) 4.

  The frame 2 is a metal base for holding the blue LED 3 and the phosphor-containing portion 4. On the upper surface of the frame 2, a trapezoidal concave section (dent) 2 </ b> A that opens upward in FIG. 1 a is formed. Thereby, since the frame 2 has a cup shape, the light emitted from the light emitting device 1 can have directivity, and the emitted light can be used effectively. Further, the inner surface of the concave portion 2A of the frame 2 is enhanced in the reflectance of light in the entire visible light region by metal plating such as silver, so that the light hitting the inner surface of the concave portion 2A of the frame 2 can also be emitted. Can be discharged in a predetermined direction.

  A blue LED 3 is installed as a light source at the bottom of the recess 2 </ b> A of the frame 2. The blue LED 3 is an LED that emits blue light when supplied with electric power. Part of the blue light emitted from the blue LED 3 is absorbed as excitation light by the light-emitting substance (the first phosphor and the second phosphor) in the phosphor-containing part 4, and another part is The light is emitted from the light emitting device 1 in a predetermined direction.

  The blue LED 3 is installed at the bottom of the recess 2A of the frame 2 as described above. Here, the frame 2 and the blue LED 3 are bonded by a silver paste (a mixture of silver particles in an adhesive) 5. Thus, the blue LED 3 is installed on the frame 2. Further, the silver paste 5 also plays a role of efficiently radiating heat generated in the blue LED 3 to the frame 2.

  Further, a gold wire 6 for supplying power to the blue LED 3 is attached to the frame 2. That is, the electrode (not shown) provided on the upper surface of the blue LED 3 is connected by wire bonding using the wire 6, and when the wire 6 is energized, power is supplied to the blue LED 3. It emits blue light. One or a plurality of wires 6 are attached in accordance with the structure of the blue LED 3.

Further, the concave portion 2A of the frame 2 is provided with a phosphor-containing portion 4 that absorbs part of the light emitted from the blue LED 3 and emits light having a different wavelength. The phosphor-containing part 4 is formed of a phosphor and a transparent resin (sealing material). The phosphor is a substance that is excited by blue light emitted from the blue LED 3 and emits light having a wavelength longer than that of the blue light. The phosphor constituting the phosphor-containing part 4 may be a single type or a mixture of a plurality of colors, and the sum of the light emitted from the blue LED 3 and the light emitted from the phosphor-containing part 4 is a desired color. Choose to be. The color is not limited to white, but may be yellow, orange, pink, purple, blue-green, or the like. Further, it may be an intermediate color between these colors and white. Here, for example, an orange phosphor (first phosphor) and a green phosphor (second phosphor) made of the phosphor of the present invention are used as phosphors, and white light is emitted from the light emitting device. Suppose that
Further, the transparent resin is a sealing material for the phosphor-containing portion 4, and here, the above-described sealing material is used.

  The mold unit 7 functions as a lens for protecting the blue LED 3, the phosphor-containing unit 4, the wire 6 and the like from the outside and controlling the light distribution characteristics. Silicone resin can be mainly used for the mold part 7.

  Since the light emitting device of the present embodiment is configured as described above, when the blue LED 3 emits light, the orange phosphor and the green phosphor in the phosphor containing portion 4 are excited to emit light. As a result, the light emitting device emits white light composed of blue light emitted from the blue LED 3, orange light emitted from the orange phosphor, and green light emitted from the green phosphor.

  At this time, in the light emitting device of this embodiment, the phosphor of the present invention having excellent temperature characteristics is used as the orange phosphor. For this reason, even if the blue LED 3 generates heat, the brightness of the light emitted from the orange phosphor does not greatly decrease. As a result, it is possible to suppress a decrease in the light emission intensity of the light emitting device due to the heat generated by the blue LED 3, and the light emitting device emits light. It is possible to prevent the color from changing due to a decrease in luminance of orange light. For this reason, even if it is a case where high output LED is used as a 1st light-emitting body, the fluorescent substance containing part 4 containing the fluorescent substance of this invention has few fall of emitted light intensity and a change of emitted light color.

The light-emitting device of the present invention is not limited to the above-described embodiment, and can be implemented with any changes without departing from the gist thereof.
For example, a surface-emitting type can be used as the first light emitter, and a film-like one can be used as the second light emitter. In this case, it is preferable to have a shape in which the film-shaped second light emitter is in direct contact with the light emitting surface of the first light emitter. In addition, contact here means producing the state which the 1st light-emitting body and the 2nd light-emitting body have touched exactly without passing air or gas. As a result, it is possible to avoid a light amount loss in which light from the first light emitter is reflected by the film surface of the second light emitter and oozes out, so that the light emission efficiency of the entire apparatus can be improved.

FIG. 2 is a schematic perspective view showing an example of a light emitting device in which a surface light emitting type is used as the first light emitter and a film-like one is applied as the second light emitter. In the light-emitting device 8 shown in FIG. 2, a surface-emitting GaN-based LD 10 as a first light-emitting body is provided on a substrate 9, and a film-shaped second light-emitting body 11 is formed on the surface-emitting GaN-based LD 10. Has been. Here, in order to create a state where they are in contact with each other, the LD 10 as the first light emitter and the second light emitter 11 are prepared separately, and their surfaces are brought into contact with each other by an adhesive or other means. Alternatively, the second light emitter 11 may be formed (molded) on the light emitting surface of the LD 10. As a result, the LD 11 and the second light emitter 11 can be brought into contact with each other.
According to the light-emitting device 8 having such a configuration, in addition to the same advantages as those of the above-described embodiment, it is possible to improve the light emission efficiency by avoiding the loss of light amount.

[2-5. Application of light emitting device]
The application of the light-emitting device of the present invention is not particularly limited, and can be used in various fields where a normal light-emitting device is used. Among these, since the temperature characteristics are good, the light emitting device of the present invention is particularly preferably used as a light source of an image display device and a lighting device.
In addition, when using the light-emitting device of this invention as a light source of an image display apparatus, using with a color filter is preferable. For example, when the image display device is a color image display device using color liquid crystal display elements, the light emitting device is used as a backlight, a light shutter using liquid crystal, and a color filter having red, green, and blue pixels; By combining these, an image display device can be formed.

Further, for example, when the light emitting device of the present invention is used for an image display device as described above, the phosphor of the present invention and (Ba, Sr) ₂ SiO ₄ : Eu are used as the second light emitter together with the color filter. It is preferable to use it. Compared to the case where a light emitting device using only a yellow phosphor (for example, a YAG phosphor) is used for an image display device, the color rendering property is extremely high, and the light utilization efficiency is higher. It is because it is excellent in brightness and high in brightness.

  An example of a surface emitting illumination device 12 incorporating the light emitting device 1 is schematically shown in FIG. In the surface light emitting illumination device 12, a large number of light emitting devices 1 are provided on the bottom surface of a rectangular holding case 13 whose inner surface is light-opaque such as a white smooth surface, and a power source for driving the light emitting device 1 is provided on the outside thereof. And a circuit or the like (not shown). In order to make the light emission uniform, a diffuser plate 14 such as a milky white acrylic plate is fixed to a portion corresponding to the lid portion of the holding case 13.

  When the surface emitting illumination device 12 is used, the light emitting device 1 emits light. This light is transmitted through the diffusion plate 14 and emitted upward in the drawing, and illumination light with uniform brightness can be obtained within the surface of the diffusion plate 14 of the holding case 13.

  EXAMPLES Hereinafter, although this invention is demonstrated still in detail using an Example, this invention is not limited to a following example, unless the summary is exceeded.

[Measurement and evaluation of phosphors]
In each example , each reference example, and each comparative example described later, various evaluations of the phosphor particles were performed by the following methods.

(Emission spectrum)
The emission spectrum of the phosphor was measured using a 150 W xenon lamp as an excitation light source and a fluorescence measuring apparatus (manufactured by JASCO Corporation) equipped with a multi-channel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measuring apparatus. The light from the excitation light source was passed through a diffraction grating spectrometer having a focal length of 10 cm, and only the excitation light having a wavelength of 400 nm, 405 nm, 455 nm, or 460 nm was irradiated to the phosphor through the optical fiber. The light generated from the phosphor by the irradiation of the excitation light is dispersed by a diffraction grating spectrometer having a focal length of 25 cm, and the emission intensity of each wavelength is measured by a spectrum measuring device in a wavelength range of 300 nm or more and 800 nm or less. An emission spectrum was obtained through signal processing such as sensitivity correction.

(Peak emission wavelength, emission peak intensity and half width)
The emission peak wavelength and half width were read from the obtained emission spectrum. The emission peak intensity was expressed as a relative value based on the peak intensity of the phosphor of Comparative Example 3 (P46-Y3 manufactured by Kasei Optics).

(Chromaticity coordinates)
Chromaticity coordinates in the XYZ color system defined by JIS Z8701 from the data in the wavelength region of 420 nm to 800 nm (excitation wavelengths 400 nm and 405 nm) or 480 nm to 800 nm (excitation wavelengths 455 nm and 460 nm) of the emission spectrum. x and y were calculated.

(Relative brightness)
Since the stimulus value Y defined by JIS Z8701 is proportional to the luminance, the relative value of the stimulus value Y is defined as the relative luminance. The phosphor of Comparative Example 3 was used as a reference.

(Excitation spectrum)
The excitation spectrum was performed with an F4500 spectrofluorometer manufactured by Hitachi.

(Light emission intensity maintenance rate and luminance maintenance rate)
MCPD7000 multi-channel spectrum measuring device manufactured by Otsuka Electronics as emission spectrum measuring device, color luminance meter BM5A as luminance measuring device, stage equipped with cooling mechanism by Peltier element and heating mechanism by heater, and device equipped with 150W xenon lamp as light source And measured.
A cell containing a phosphor sample was placed on the stage, and the temperature was changed in the range of 20 ° C to 150 ° C. It was confirmed that the surface temperature of the phosphor became constant at 20 ° C, 25 ° C, 100 ° C, 125 ° C, or 150 ° C. Next, the phosphor was excited with light of 405 nm, 455 nm, or 465 nm extracted by spectroscopy with a diffraction grating from a light source, and an emission spectrum and luminance were measured. The emission peak intensity was determined from the measured emission spectrum.
In addition, the measured value of the surface temperature of the phosphor was a value corrected by using a temperature measured value by a radiation thermometer and a thermocouple.
The relative value of the luminance value measured by the luminance measuring device to the luminance value at 20 ° C. was defined as the luminance maintenance rate.
Moreover, the relative value with respect to the luminescence peak intensity in 20 degreeC or 25 degreeC of the luminescence peak intensity | strength calculated | required from the emission spectrum measured with the spectrum measuring apparatus was made into the luminescence intensity maintenance factor.
For example, the emission intensity maintenance rate at 455 nm excitation and 125 ° C. can be determined as follows.
The emission peak intensity obtained by exciting with light having a peak wavelength of 455 nm at 25 ° C. is R ₄₅₅ (25), and the emission peak intensity obtained by exciting with light having a peak wavelength of 455 nm at 125 ° C. is R ₄₅₅ (125). In this case, the value of the following formula was set as the emission intensity maintenance rate at 125 ° C. with excitation at 455 nm.
{R ₄₅₅ (125) / R ₄₅₅ (25)} × 100
In the table below, {R ₄₅₅ (100) / R ₄₅₅ (25)} × 100 and {R ₄₀₅ (100) / R ₄₀₅ (25)} × 100 are referred to as “emission intensity maintenance rate 100 ° C.”. , {R ₄₅₅ (125) / R ₄₅₅ (25)} × 100 and {R ₄₀₅ (125) / R ₄₀₅ (25)} × 100 are referred to as “emission intensity maintenance rate 125 ° C.” and {R ₄₅₅ (150) / R ₄₅₅ (25)} × 100 and {R ₄₀₅ (150) / R ₄₀₅ (25)} × 100 are referred to as “emission intensity maintenance rate 150 ° C.”.

(Internal quantum efficiency, external quantum efficiency, and absorption efficiency)
The absorption efficiency αq, internal quantum efficiency ηi, and external quantum efficiency ηo of the phosphor were determined as follows.
First, the phosphor sample to be measured was packed in a cell with a sufficiently smooth surface so that the measurement accuracy was maintained, and was attached to an integrating sphere.

  Light was introduced into this integrating sphere from an emission light source (150 W Xe lamp) for exciting the phosphor using an optical fiber. The emission peak wavelength of light from the light emission source was adjusted using a monochromator (diffraction grating spectrometer) or the like so as to be monochromatic light of 405 nm or 455 nm. Using this monochromatic light as excitation light, the phosphor sample to be measured was irradiated, and the spectrum was measured for the emission (fluorescence) and reflected light of the phosphor sample using a spectrometer (MCPD7000 manufactured by Otsuka Electronics Co., Ltd.). The light in the integrating sphere was guided to a spectroscopic measurement device using an optical fiber.

The absorption efficiency αq is a value obtained by dividing the number of photons N _abs of the excitation light absorbed by the phosphor sample by the total number of photons N of the excitation light.

First, the total number of photons N of the latter excitation light is proportional to the numerical value obtained by the following (formula I). Therefore, a “Spectralon” manufactured by Labsphere (having a reflectance R of 98% with respect to 450 nm excitation light), which is a reflector having a reflectance R of almost 100% with respect to the excitation light, is measured as fluorescence. The sample was attached to the integrating sphere in the same arrangement as that of the body sample, irradiated with excitation light, and measured with a spectroscopic measurement device to measure the reflection spectrum I _ref (λ), and the value of the following (formula I) was obtained.

Here, the integration interval was 351 nm to 442 nm when the excitation wavelength was 405 nm, and 410 nm to 480 nm when the excitation wavelength was 455 nm.
The number N _abs of the photons in the excitation light that is absorbed in the phosphor sample is proportional to the amount calculated by the following equation (II).

Therefore, the reflection spectrum I (λ) was obtained when the phosphor sample for which the absorption efficiency αq is to be obtained was attached. The integration range of (Formula II) was the same as the integration range defined in (Formula I). Since the actual spectrum measurement value is generally obtained as digital data separated by a certain finite bandwidth with respect to λ, the integrals of (Equation I) and (Equation II) were obtained by summing based on the bandwidth. .
From the above, αq = N _abs / N = (Formula II) / (Formula I) was calculated.

Next, the internal quantum efficiency ηi was determined as follows. Internal quantum efficiency ηi is a value obtained by dividing the number N _abs of photons number NPL of photons originating from the fluorescence phenomenon absorbed by the phosphor sample.
Here, NPL is proportional to the amount obtained by the following (formula III). Therefore, the amount required by the following (formula III) was determined.

The integration interval was 443 nm to 800 nm when the excitation wavelength was 405 nm, and 481 nm to 800 nm when the excitation wavelength was 455 nm.
As described above, ηi = (formula III) / (formula II) was calculated, and the internal quantum efficiency ηi was obtained.

It should be noted that the integration from the spectrum that was converted to digital data was performed in the same manner as when the absorption efficiency αq was obtained.
And the external quantum efficiency (eta) o was calculated | required by taking the product of absorption efficiency (alpha) q calculated | required as mentioned above and internal quantum efficiency (eta) i.

(Weight median diameter)
Measurement was performed using a laser diffraction / scattering particle size distribution measuring apparatus LA-300 manufactured by HORIBA, Ltd. using ethanol as a dispersion medium.

(Powder X-ray diffraction measurement)
Powder X-ray diffraction was precisely measured with a powder X-ray diffractometer X'Pert manufactured by PANalytical. The measurement conditions are as follows.
Using CuKα tube X-ray output = 40 KV, 30 mA
Solar slit = 0.04 rad
Divergence slit = variable automatically (fixed X-ray irradiation width to sample 10mm)
Detector = Semiconductor array detector X'Celerator used, Ni filter used Scanning range 2θ = 5 to 155 degrees
Reading width = 0.015 degrees Counting time = 99.7 seconds

[Phosphor production I]
(Example 1 , Reference Example 1 , and Comparative Examples 1-2)
SrCO ₃ , BaCO ₃ , SiO ₂ , and Eu ₂ O ₃ were weighed so that Sr: Ba: Si: Eu had a molar ratio shown in Table 6, and pulverized and mixed with ethanol in an agate mortar. Ethanol was vaporized and removed to obtain a raw material mixture. The obtained raw material mixture was formed into a tablet having a diameter of 10 mm and placed on a molybdenum foil in a hydrogen-containing nitrogen atmosphere (hydrogen: nitrogen = 3: 97 (volume ratio)) and the heating temperature (maximum temperature) and heating shown in Table 5 The reaction was carried out by heating over time. Subsequently, the obtained fired product was pulverized to produce a phosphor.
In both cases, firing was performed under atmospheric pressure. Also in the following examples , reference examples, and comparative examples, the pressure condition during firing was atmospheric pressure.

(Comparative Example 3)
A commercially available yellow phosphor (Yellow phosphor (Y, Gd, Ce) ₃ Al ₅ O ₁₂ (type P46-Y3) manufactured by Kasei Optonix) was used as the phosphor of Comparative Example 3.

( Reference Example 2, Examples 4 to 8)
SrCO ₃ , BaCO ₃ , SiO ₂ , and Eu ₂ O ₃ were weighed so that Sr: Ba: Si: Eu had a molar ratio shown in Table 6, and pulverized and mixed with ethanol in an agate mortar. Ethanol was vaporized and removed to obtain a raw material mixture. The obtained raw material mixture was formed into a tablet having a diameter of 10 mm, and placed on a molybdenum foil and reacted by heating at 1450 ° C. for 6 hours in a hydrogen-containing nitrogen atmosphere (hydrogen: nitrogen = 3: 97 (volume ratio)). . Subsequently, the obtained fired product was pulverized to produce a phosphor and evaluated.

Example 9
SrCO ₃ , BaCO ₃ , SiO ₂ , and Eu ₂ O ₃ are weighed so that Sr: Ba: Si: Eu = 1.98: 1: 1: 0.02 and mixed well in a dry process to obtain a raw material mixture Got. The obtained raw material mixture was put in an alumina crucible in which platinum foil was spread on the bottom and side surfaces, and heated at 1400 ° C. for 6 hours while blowing nitrogen gas into a muffle furnace. The obtained fired product was pulverized well, placed in an alumina crucible, and heated at 1550 ° C. for 6 hours in a hydrogen-containing nitrogen atmosphere (hydrogen: nitrogen = 4: 96 (volume ratio)). The obtained fired product was pulverized and passed through a nylon mesh having an opening of 37 μm to produce a phosphor. The weight median diameter (D ₅₀ ) of this phosphor was 19.8 μm.

(Example 10)
In Example 9, a phosphor was manufactured in the same manner as in Example 9 except that the raw material mixture was directly put into an alumina crucible without using a platinum foil in the first firing.

(Examples 11 to 16, Comparative Example 4)
SrCO ₃ , BaCO ₃ , SiO ₂ , and Eu ₂ O ₃ were weighed so that the molar ratios shown in Table 6 were obtained, and mixed well by a dry method to obtain a raw material mixture. The obtained raw material mixture was put into an alumina crucible in which platinum foil was spread on the bottom and side surfaces, and heated at 1400 ° C. for 3 hours while blowing nitrogen gas into the muffle furnace. This was pulverized well, put into an alumina crucible in which molybdenum foil was spread on the bottom and side surfaces, and heated at 1550 ° C. for 3 hours under a hydrogen-containing nitrogen atmosphere (hydrogen: nitrogen = 4: 96 (volume ratio)). The obtained fired product was pulverized and passed through a nylon mesh having an opening of 37 μm to produce a phosphor.

(Examples 17 to 19)
The phosphors of Examples 17 to 19 were manufactured in the same manner as Example 9 except that the composition ratio of the phosphors (Sr / Ba / Eu ratio) was changed to the values shown in Table 6.

(Example 20)
SrCO ₃ , BaCO ₃ , SiO ₂ , and Eu ₂ O ₃ are weighed so that Sr: Ba: Si: Eu = 1.98: 1: 1: 0.02 and mixed well in a dry process to obtain a raw material mixture Got. The obtained raw material mixture was put into an alumina crucible in which platinum foil was spread on the bottom and side surfaces, and heated at 1400 ° C. for 6 hours in a hydrogen-containing nitrogen atmosphere (hydrogen: nitrogen = 4: 96 (volume ratio)). This was pulverized well, put in an alumina crucible, and heated at 1550 ° C. for 6 hours in a hydrogen-containing nitrogen atmosphere (hydrogen: nitrogen = 4: 96 (volume ratio)). The obtained fired product was pulverized and passed through a nylon mesh having an opening of 37 μm to produce a phosphor.

(Example 21)
SrCO ₃ , BaCO ₃ , SiO ₂ , and Eu ₂ O ₃ are weighed so that Sr: Ba: Si: Eu = 1.98: 1: 1: 0.02 and mixed well in a dry process to obtain a raw material mixture Got. The obtained raw material mixture was placed in an alumina crucible in which platinum foil was spread on the bottom and side surfaces, and heated at 1400 ° C. for 6 hours while blowing nitrogen gas into the muffle furnace. This was pulverized well, placed in an alumina crucible, and heated at 1550 ° C. for 6 hours in a hydrogen-containing nitrogen atmosphere (hydrogen: nitrogen = 4: 96 (volume ratio)). The obtained fired product was pulverized and passed through a nylon mesh having an opening of 37 μm to produce a phosphor.

(Example 22)
The phosphor obtained in Example 21 was placed in 5 times the weight of water, stirred well, and filtered. After performing the same operation once again, it was dried in air at 120 ° C. until dry.

[Evaluation of phosphor IA]
(Emission characteristics at 405 nm excitation and 455 nm excitation)
With respect to the phosphors of Examples 1 and 4 to 22, Reference Examples 1 and 2, and Comparative Examples 2 and 4, the emission peak wavelength and emission peak when excited by 405 nm light and 455 nm light by the above-described method. Intensity, half width, luminance, chromaticity coordinates, emission intensity maintenance ratio, internal quantum efficiency, external quantum efficiency, absorption efficiency, and weight median diameter (D ₅₀ ) were measured. The results are shown in Tables 7 and 8.
From Tables 7 and 8, it can be seen that the phosphors produced in Examples 1 to 22 have a high emission intensity maintenance rate at high temperatures and are excellent in temperature characteristics.
From the results of Reference Example 2 and Examples 4 to 8, the Eu amount as the activator element is the Eu molar amount when the total molar amount of Sr, Ba and Eu is set to 3 (y in the above formula [1]). It was found that the emission intensity was highest when the value was 0.02. That is, it is understood that it is preferable to manufacture the phosphor before and after this Eu amount.

  From the results of Examples 11 to 19, regarding the molar ratio of Sr and Ba, it is found that the emission peak intensity becomes the highest when the Sr / Ba molar ratio is approximately 2/1 to 2.2 / 0.8. It was. When Ba is further decreased, the emission peak intensity is slightly reduced, but the emission peak wavelength is shifted from the longer wavelength (the x value is increased and the y value is decreased), so that the phosphor has a slightly larger red component. This phosphor has a large red component and is suitably used for applications that require high color rendering properties.

When the phosphor is washed with water as in Example 22, impurities attached to the phosphor surface can be removed, and fine particles generated by pulverization or the like can be removed, which is practically preferable.
When firing twice, as in Example 20, the first firing can be performed in a reducing atmosphere (mixed gas of nitrogen and hydrogen) as in the second firing.

[Evaluation of phosphor IB]
(Powder X-ray diffraction pattern)
The measurement result of the phosphor of Example 1 is shown in FIG. 4a together with the analysis result by Rietveld method. In this figure, on the top (A in FIG. 4a), the measured value of the diffraction brightness of the obtained phosphor (x mark) and the diffraction intensity data (solid line) obtained by pattern fitting are shown superimposed, from above. The second vertical line (B in FIG. 4a) indicates the position where the diffraction peak is present in the pattern fitting result, and the third curve (C in FIG. 4a) is the actual measurement of the diffraction luminance of the phosphor. The difference between the value and the pattern fitting result is shown. Further, FIG. 4b shows a result obtained by connecting measured values of diffraction luminance of the obtained phosphor with a solid line.

  The analysis by the Rietveld method was performed by performing pattern fitting on the assumption that the space group of the phosphor of Example 1 was I4 / mcm (No. 140). Although not shown here, even if the analysis was performed assuming that the space group of the phosphor of Example 1 was P4 / ncc (No. 130), pattern fitting could be performed with almost the same accuracy. Therefore, the phosphor of Example 1 is considered to belong to the space group I4 / mcm (No. 140) or the space group P4 / ncc (No. 130).

Table 9a to Table 9e show the surface index, diffraction intensity (2θ), surface interval, measured intensity, and calculated intensity of each diffraction peak obtained as a result of pattern fitting. In the measured data of the diffraction intensity of the phosphor, an impurity phase peak not derived from the phosphor crystal of Example 1 was confirmed, but this is not described in the table. The calculated values were obtained from the following equation [8], where the lattice constants of tetragonal a-axis, b-axis and c-axis were a, b and c, respectively, and the plane index was (hkl). From Tables 9a to 9e, it can be seen that the measured values and calculated values of the diffraction intensities at the respective diffraction angles are almost the same.
2θ = 2sin ⁻¹ [0.5λ (h ² / a ² + k ² / b ² + l ² / c ² ) ^0.5 ] ... [8]
In addition, λ is the wavelength of 1.54056 mm of the CuKα ray used as the X-ray source.
Table 10 summarizes crystal structure parameters such as lattice constants and atomic coordinates obtained as a result of pattern fitting.

(Emission characteristics I at 400 nm excitation and 460 nm excitation)
With respect to the phosphors of Example 1, Reference Example 1 (and Reference Example 3 described later), and Comparative Examples 1 and 2, emission characteristics at 400 nm excitation and 460 nm excitation were measured.
The emission spectra of Example 1, Reference Example 1 (and Reference Example 3 below), and Comparative Examples 1 and 2 are shown in FIG. 5 (excitation at 460 nm) and FIG. 6 (excitation at 400 nm).

Tables 11 and 12 show the emission peak wavelength, relative emission peak intensity, chromaticity coordinates, and relative luminance for the phosphors of Example 1, Reference Example 1 (and Reference Example 3 below), and Comparative Examples 1-2. Summarized in

Table 11 shows the relative emission peak intensity and the relative luminance calculated from the emission spectrum when excited at a peak wavelength of 460 nm. The relative emission peak intensity and the relative luminance are relative values obtained by setting the emission peak intensity and the luminance when the phosphor of Comparative Example 3 is excited at a wavelength of 460 nm as 102.
Table 12 shows the relative emission peak intensity and the relative luminance calculated from the emission spectrum when excited at a peak wavelength of 400 nm. The relative peak intensity and the relative luminance are relative values obtained by setting the emission peak intensity and the luminance when the phosphor of Comparative Example 3 is excited at a wavelength of 460 nm as 100.
From these measurement results, it can be seen that the phosphor (Example 1) having the Sr _1.98 BaEu _0.02 SiO ₅ composition has the highest emission intensity.

(Emission characteristics at 400 nm excitation and 460 nm excitation II)
For the phosphors of Reference Example 2 and Examples 4 to 8, the emission peak wavelength, relative emission peak intensity, chromaticity coordinates, and relative luminance were measured, and the results are shown in Tables 13 and 14.
Table 13 shows the relative emission peak intensity and the relative luminance calculated from the emission spectrum when excited at a peak wavelength of 460 nm. The relative peak intensity and the relative luminance are relative values obtained by setting the emission peak intensity and the luminance when the phosphor of Comparative Example 3 measured at the same time is excited at a wavelength of 460 nm as 100.
Table 14 shows the relative emission peak intensity and the relative luminance calculated from the emission spectrum when excited at a peak wavelength of 400 nm. The relative peak intensity and the relative luminance are relative values obtained by setting the emission peak intensity and the luminance when the phosphor of Comparative Example 3 is excited at a wavelength of 460 nm as 100.

FIG. 10 shows the relationship between the amount of Eu added at the excitation wavelength of 460 nm, the emission peak wavelength, and the relative emission peak intensity.
From the results of Reference Example 2 and Examples 4 to 8, the Eu amount as the activator element is the Eu molar amount when the total molar amount of Sr, Ba and Eu is set to 3 (y in the above formula [1]). It was found that the emission intensity was highest when the value was 0.02. That is, it is understood that it is preferable to manufacture the phosphor before and after this Eu amount.

(Emission characteristics at 455 nm excitation)
For the phosphors of Examples 9 and 10, the emission peak wavelength, relative emission peak intensity, chromaticity coordinates, and relative luminance when excited at 455 nm were measured, and the results are shown in Table 15.
The relative peak intensity and the relative luminance are relative values obtained by setting the emission peak intensity and the luminance when the phosphor of Comparative Example 3 measured at the same time is excited at a wavelength of 460 nm as 100.

The phosphor of Example 10 had a lower emission peak intensity than the phosphor of Example 9. The reason is considered that the heat treatment at a high temperature of 1400 ° C. was performed in an alumina crucible without using a platinum foil, so that the phosphor raw material mixture reacted with alumina, and the Al component was mixed in the phosphor. .
When the Al content of these phosphors was measured, the phosphor of Example 10 contained 380 μg of Al per gram, and the phosphor of Example 9 contained 30 μg of Al per gram. It was. Therefore, it is considered that the phosphor of Example 10 was mixed with Al derived from the alumina crucible.

(Excitation spectrum)
An excitation spectrum of the phosphor of Example 1 is shown in FIG. From this figure, the phosphor of Example 1 can be excited by light in the wavelength range of 300 nm or more and 500 nm or less, and in particular, efficiently uses light in the ultraviolet region, near-ultraviolet region, and visible light region having a wavelength shorter than 500 nm. It can be seen that it absorbs well and emits light.

(Emission intensity maintenance factor and luminance maintenance factor at an excitation wavelength of 465 nm)
With respect to the phosphor of Example 1, the emission intensity maintenance ratio and the luminance maintenance ratio with respect to temperature change were measured.
The luminance value measured by the luminance meter is normalized with the luminance value at 20 ° C. and shown in FIG.
The emission peak intensity measured by the spectrum measuring apparatus is normalized with the emission peak intensity at 20 ° C. and shown in FIG.
From FIG. 9, it was found that this phosphor hardly caused temperature quenching in the temperature range from room temperature (20 ° C.) to about 150 ° C.

[Phosphor production II]
( Reference Example 3 )
SrCO ₃ , BaCO ₃ , SiO ₂ , and Eu ₂ O ₃ were weighed so that Sr: Ba: Si: Eu had a molar ratio shown in Table 16, and pulverized and mixed with ethanol in an agate mortar. Ethanol was vaporized and removed to obtain a raw material mixture. The obtained raw material mixture was formed into a tablet having a diameter of 10 mm and placed on a molybdenum foil in a hydrogen-containing nitrogen atmosphere (hydrogen: nitrogen = 3: 97 (volume ratio)) at a heating temperature (maximum temperature) of 1250 ° C. and a heating time of 6 The reaction was carried out by heating over time. Subsequently, the obtained fired product was pulverized to produce a phosphor.

( Reference Examples 4-7 )
SrCO ₃ , BaCO ₃ , SiO ₂ , and Eu ₂ O ₃ were weighed so as to have the molar ratios shown in Table 16, and mixed well in a dry process to obtain a raw material mixture. The obtained raw material mixture was put into an alumina crucible in which platinum foil was spread on the bottom and side surfaces, and heated at 1400 ° C. for 3 hours while blowing nitrogen gas into the muffle furnace. This was pulverized well, put into an alumina crucible in which molybdenum foil was spread on the bottom and side surfaces, and heated at 1550 ° C. for 3 hours under a hydrogen-containing nitrogen atmosphere (hydrogen: nitrogen = 4: 96 (volume ratio)). The obtained fired product was pulverized and passed through a nylon mesh having an opening of 37 μm to produce a phosphor.

[Evaluation of phosphor II]
(Emission characteristics at 405 nm excitation and 455 nm excitation)
For the phosphors of Reference Examples 3 to 7 , when excited by 405 nm light and 455 nm light according to the above-described method, the emission peak wavelength, emission peak intensity, half-value width, luminance, chromaticity coordinates, emission intensity maintenance rate The internal quantum efficiency, the external quantum efficiency, the absorption efficiency, and the weight median diameter (D ₅₀ ) were measured. The results are shown in Tables 17 and 18.

When the molar ratio of Sr / Ba exceeds 2.5 / 0.5 and Sr increases, the emission wavelength shifts to a short wavelength as Sr increases. When Sr / Ba is about 2.4 / 0.6 to 2.6 / 0.4, the emission peak wavelength is longest. When it is desired to increase the red component, it is preferable to adjust the Sr / Ba ratio within this range.
From these results, by setting the Ba ratio x in the range of 0.5 or more and 0.8 or less, it is possible to obtain a phosphor having an emission peak close to a long wavelength and a particularly large emission peak intensity. I understand.

  From the above results, it can be seen that the phosphor satisfying the formula [1] is a phosphor having good temperature characteristics and high internal quantum efficiency and emission peak intensity. Furthermore, since the phosphor has a good balance between luminance and reddish components, the use of this phosphor makes it possible to manufacture a light emitting device with high characteristics.

[Surface treatment and durability evaluation]
(Example 28)
Using the orange phosphor obtained in Example 1 and the green phosphor (Ba _1.39 Sr _0.46 Eu _0.15 ) SiO ₄ , a white light emitting device was produced by the following procedure.
An LED chip “C460-MB290” (emission wavelength: 461 nm) manufactured by CREE was bonded to an SMD LED package “TY-SMD1202B” manufactured by Toyo Denki.
An epoxy resin “YL-7301” and a curing agent “YLH-1230” manufactured by Japan Epoxy Resin Co., Ltd. were mixed at a ratio of 100 parts by weight: 80 parts by weight. To 100 parts by weight of the mixture, 5.3 parts by weight of an orange phosphor, green 5.8 parts by weight of phosphor and 1.0 part by weight of “RY200” manufactured by Nippon Aerosil Co., Ltd. are added as fillers, and the mixture contains phosphor by kneading for 3 minutes with a stirrer “Awatori Netaro AR-100” manufactured by Shinky Corporation It was set as the composition.
This composition was filled to the uppermost surface of the package with the LED chip, and heat-cured at 100 ° C. for 3 hours and then at 140 ° C. for 3 hours.

The obtained light emitting device was driven at 20 mA at room temperature (about 24 ° C.), and CIE chromaticity coordinates x were measured.
Next, after the light emitting device was allowed to stand for 500 hours under high temperature and high humidity conditions of 85 ° C. and 85% RH, the CIE chromaticity coordinate x was measured in the same manner.
And the ratio (x maintenance factor:%) of the chromaticity coordinate x after 500-hour high-temperature, high-humidity exposure with respect to the chromaticity coordinate x immediately after manufacture of the said light-emitting device was computed, and the result was shown in Table 19.

(Example 29)
3 g of the orange phosphor obtained in Example 1 was placed in a 50 ml flask, and 20 ml of ethanol was added and stirred. Next, 6.7 g of 28 wt% aqueous ammonia was added, and the mixture was stirred for 1 minute with a magnetic stirrer.
Next, 20 mL of tetraethylorthosilicate was gradually added in two portions while vigorously stirring with a magnetic stirrer, and subsequently stirred for 90 minutes with a magnetic stirrer.
The resulting solution was allowed to stand for 3 minutes, and then the supernatant was removed with a dropper or the like.
Thereafter, addition of 30 mL of ethanol, stirring for 1 minute, standing for 3 minutes, and removal of the supernatant were repeated until the supernatant became colorless and transparent.
The obtained sediment was dried under reduced pressure at 150 ° C. for 2 hours with a vacuum dryer to obtain a surface-treated orange phosphor.
The surface-treated orange phosphor had a 13.8% by weight silicon oxide film attached to the weight of the phosphor. The film thickness is about 100 nm.

  A white light emitting device was produced in the same manner as in Example 28 except that this surface-treated orange phosphor was used as the orange phosphor. Similarly, the chromaticity coordinates x immediately after the light emitting device was manufactured and the high temperature and high humidity exposure 500 The chromaticity coordinates x after the elapse of time and the x maintenance rate were examined, and the results are shown in Table 19.

  As is clear from the results of Examples 28 and 29, when the surface-treated phosphor of the present invention is used, the white light emitting device has a further excellent effect in durability performance when exposed to a high temperature and high humidity environment. .

[Production and evaluation of light-emitting device]
(Example 30)
A surface-mounted white light-emitting device having the configuration shown in FIG. 1b was produced by the following procedure. Of the constituent elements of the thirtieth embodiment, the constituent elements corresponding to those shown in FIG.
As the first luminous body (21), 460-MB, which is a blue LED manufactured by Cree, which emits light at a wavelength of 460 nm, was used. This blue LED (21) was die-bonded to the terminal (26) at the bottom of the recess of the frame (23) using a silver paste as an adhesive. Next, the electrode of the blue LED (21) and the terminal (25) of the frame (23) were wire-bonded. A gold wire having a diameter of 25 μm was used as the wire (24).

As the luminescent material of the phosphor-containing part (22), the phosphor of Example 1 as an orange phosphor and Ce-activated Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ as a green phosphor were used. A silicone resin was used as the sealing material.
These two types of phosphors and silicone resin were mixed, and the resulting mixture of phosphor and silicone resin was injected into the recess of the frame (23) to which the blue LED (21) was bonded. This was held at 150 ° C. for 2 hours to cure the silicone resin, thereby forming a phosphor-containing part (22) to produce a surface-mounted white light emitting device.
The mixing ratio of the orange phosphor and the green phosphor and the mixing ratio of the silicone resin with respect to the total weight of the phosphor are as follows.

<Mixing ratio>
Orange phosphor: green phosphor = 72:18 (weight ratio)
Total phosphor: silicone resin = 9: 100 (weight ratio)

Further, Ce-activated Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ as a green phosphor was synthesized as follows.
Each material of CaCO ₃ , Mg (OH) ₂ .3MgCO ₃ .3H ₂ O, Sc ₂ O ₃ , SiO ₂ and Ce (NO ₃ ) ₃ (aqueous solution) was put in an agate mortar with a small amount of ethanol and mixed well. Thereafter, it was dried to obtain a raw material mixture. The raw material mixture was wrapped in platinum foil and fired by heating at 1500 ° C. for 3 hours under atmospheric pressure while flowing hydrogen-containing nitrogen gas (hydrogen: nitrogen = 4: 96 (volume ratio)). Next, a green phosphor was synthesized by pulverizing and classifying the obtained fired product.

<Raw material>
CaCO ₃ : 0.0297 mol Mg (OH) ₂ .3MgCO ₃ .3H ₂ O: 0.0006 mol as Mg Sc ₂ O ₃ : 0.0097 mol SiO ₂ : 0.03 mol Ce (NO ₃ ) ₃ (aqueous solution) : 0.0003 mol

  At room temperature (about 24 ° C.), the obtained white light emitting device was driven by applying a current of 20 mA to the LED (21) to emit light. All the light emission from the white light emitting device was received by an integrating sphere, and further introduced into a spectroscope by an optical fiber, and the emission spectrum and total luminous flux were measured.

The emission spectrum of this white light emitting device is shown in FIG. Further, among the measurement results of the emission spectrum, CIE chromaticity coordinate values x and y were obtained based on the numerical value of the emission intensity in the wavelength range of 380 nm to 780 nm. As a result, x = 0.33, y = 0.34. Met.
The total luminous flux was 2 lumens (lm), and the luminous efficiency was 29 lm / W.

(Comparative Example 5)
Example 12 except that “Yellow phosphor (Y, Gd, Ce) ₃ Al ₅ O ₁₂ (type P46-Y3)” (phosphor of Comparative Example 3) manufactured by Kasei Optonix was used as the phosphor. A surface mount type white light emitting device was manufactured in the same procedure. When the evaluation was performed in the same manner as in Example 12, the CIE chromaticity coordinate values x and y were x = 0.33, y = 0.32, the total luminous flux was 1.6 lm, and the luminous efficiency was 23 lm / W.

As is clear from the results of Example 30 and Comparative Example 5, white light emission using the orange phosphor obtained in Example 1 and the green phosphor Ce-activated Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ The device is superior in luminous efficiency to a white light emitting device using a yellow phosphor (Y, Gd, Ce) ₃ Al ₅ O ₁₂ .

(Examples 31-112)
A surface mount type white light emitting device was prepared by the following procedure.
Although the obtained white light emitting device is not white in a strict sense, it is generically referred to as a white light emitting device here.

The phosphors used are as shown below.
Orange phosphor A = phosphor obtained in Example 9 Yellow phosphor 2 = Y ₃ Al ₅ O ₁₂ : Ce ³⁺ , Tb ³⁺
Green phosphor 1 = Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce ³⁺ (the same green phosphor as used in Example 30)
Green phosphor 2 = Ba _1.39 Sr _0.46 Eu _0.15 SiO ₄
Blue phosphor 1 = Ba _0.7 Eu _0.3 MgAl ₁₀ O ₁₇

The yellow phosphor 2, the green phosphor 2 and the blue phosphor 1 were synthesized as follows.
(Yellow phosphor 2)
After thoroughly mixing each raw material of Y ₂ O ₃ , Tb ₄ O ₇ , CeO ₂ and Al ₂ O ₃ weighed to a predetermined amount with BaF _{2 as} a flux, it is put in an alumina crucible and a hydrogen-containing nitrogen atmosphere ( Firing was carried out by heating at 1450 ° C. for 2 hours in (hydrogen: nitrogen = 4: 96 (volume ratio)). Next, the obtained fired product was pulverized, washed, classified, and dried to synthesize yellow phosphor 2 (Y ₃ Al ₅ O ₁₂ : Ce ³⁺ , Tb ³⁺ ).

(Green phosphor 2)
BaCO ₃ , SrCO ₃ , SiO ₂ , and Eu ₂ O ₃ were weighed so as to have a molar ratio of Sr: Ba: Eu: Si = 1.39: 0.46: 0.15: 1 and a small amount of ethanol. The mixture was put in an agate mortar and mixed well, and then dried to obtain a raw material mixture. The obtained raw material mixture was put into an alumina crucible and fired by heating at 1200 ° C. for 6 hours in a hydrogen-containing nitrogen atmosphere (hydrogen: nitrogen = 4: 96 (volume ratio)). Next, the obtained fired product was pulverized and classified to synthesize green phosphor 2A (Ba _1.39 Sr _0.46 Eu _0.15 SiO ₄ ).
Further, green phosphors of different production lots were synthesized by the same synthesis method as described above, and this was designated as green phosphor 2B (Ba _1.39 Sr _0.46 Eu _0.15 SiO ₄ ).

(Blue phosphor 1)
BaCO ₃ , Eu ₂ O ₃ , basic magnesium carbonate (MgCO ₃ .nMg (OH) ₂ ) weighed to have a molar ratio of Ba: Eu: Mg: Al = 0.7: 0.3: 1: 10 And γ-Al ₂ O ₃ and 0.3% by weight of AlF ₃ based on the total weight of these were put in an agate mortar with a small amount of ethanol, mixed well, and dried to obtain a raw material mixture. The obtained raw material mixture was put into an alumina crucible and fired by heating at 1450 ° C. for 3 hours in a hydrogen-containing nitrogen atmosphere (hydrogen: nitrogen = 4: 96 (volume ratio)). Subsequently, the obtained fired product was pulverized and classified to synthesize blue phosphor 1 (Ba _0.7 Eu _0.3 MgAl ₁₀ O ₁₇ ).

A surface-mounted white light-emitting device having the configuration shown in FIG. 1b was produced by the following procedure. In addition, about the thing in which the component corresponding to FIG. 1b is drawn, the code | symbol is suitably shown in parenthesis.
As the first luminous body (21), 460-MB, which is a blue LED manufactured by Cree, which emits light at a wavelength of 460 nm, was used. This blue LED (21) was die-bonded to the terminal (26) at the bottom of the recess of the frame (23) using a silver paste as an adhesive. Next, the electrode of the blue LED (21) and the terminal (25) of the frame (23) were wire-bonded. A gold wire having a diameter of 25 μm was used as the wire (24).

  As the luminescent material of the phosphor-containing part (22), one or more of the above-mentioned orange phosphor, yellow phosphor 2, green phosphor 1, green phosphor 2A, green phosphor 2B and blue phosphor 1 are used. Was used. An epoxy resin was used as the sealing material.

  One or more of orange phosphor, yellow phosphor 2, green phosphor 1, green phosphor 2A, green phosphor 2B, and blue phosphor 1, epoxy resin (Japan Epoxy Resin YL7301), epoxy A resin curing agent (YLH1230 manufactured by Japan Epoxy Resin Co., Ltd.) and additives (Aerosil (registered trademark), AEROSIL 130 manufactured by Nippon Aerosil Co., Ltd.) were mixed well.

  The mixing ratio of the epoxy resin, the epoxy resin curing agent and the additive is epoxy resin: epoxy resin curing agent: additive = 100: 80: 3.6 (weight ratio), and is based on the total weight of the epoxy resin and the epoxy resin curing agent. The mixing ratio of the phosphors was as shown in Tables 20 to 27.

The obtained mixture was injected into the concave portion of the frame (23) to which the blue LED (21) was bonded. This was heat-treated at 100 ° C. for 3 hours, and further heated at 140 ° C. for 3 hours to cure the epoxy resin, thereby forming a phosphor-containing part (22) to produce a surface-mounted white light emitting device.
About the produced white light-emitting device, evaluation mentioned later was performed and the result was shown to Tables 20-27.

(Examples 113 to 154)
As shown below, a near-ultraviolet LED that emits light at a wavelength of 395 nm was used instead of a blue LED, a combination and a mixing ratio of phosphors were changed, a silicone resin was used as a sealing material, a phosphor A surface-mount light-emitting device was fabricated in the same manner as in Examples 31 to 112 except that the heating conditions for forming the containing portion were changed.

Near UV LED: C395-MB manufactured by Cree
Combinations and mixing ratios of phosphors: As shown in Tables 28 to 32 (mixing ratio is a mixing ratio of phosphors with respect to the weight of the silicone resin).
Sealing material: Silicone resin (Toray Dow Corning 6101)
Heating conditions: Heated at 150 ° C. for 2 hours The fabricated light-emitting device was evaluated as described later, and the results (characteristics) are shown in Tables 28 to 32.

[Evaluation of Light Emitting Device (Examples 113 to 154)]
Emission spectrum: measured in the same manner as in Example 30. The emission spectra of the light emitting devices manufactured in Examples 41, 54, 86, 108, 112, 127, 142, 144, and 150 are shown in FIGS.

CIE chromaticity coordinate values x and y: calculated from the emission spectrum of the obtained light emitting device according to JIS Z8701.
Total luminous flux (unit: lm): measured in the same manner as in Example 30.
Luminous power (unit: lm / W): A value obtained by dividing the total luminous flux by the radiant flux W1 when a blue LED or near-ultraviolet LED before the phosphor-containing portion is formed is driven by applying a current of 20 mA to emit light. .
Luminous efficiency (unit: lm / W): A value obtained by dividing the total luminous flux by the power consumption W2 when the blue LED or near-ultraviolet LED before the phosphor-containing portion is formed and driven by supplying a current of 20 mA to emit light. .
Average color rendering index Ra: calculated according to the definition of JIS Z8726.
W1 (unit: mW): A radiant flux obtained by driving a blue LED or near-ultraviolet LED with a current of 20 mA before the phosphor-containing portion is formed in order to grasp the manufacturing variation of the LED.
Energizing voltage (unit V): A voltage between terminals when a blue LED or near-ultraviolet LED is driven by energizing a current of 20 mA.
W2 (unit: mW): power consumption obtained as a product of the energization voltage and the energization current.

Table 20 is a characteristic list of light emitting devices manufactured using only the blue LED and the orange phosphor A. As described above, the light emitting device using the blue LED and the orange phosphor of the present invention emits light in purple, pink, amber, orange, red, etc., and has high luminance, so it is suitable as various display devices and in-vehicle light sources. Can be used for
Table 21 is a characteristic list of white light emitting devices manufactured using the blue LED, the orange phosphor A, and the yellow phosphor 2. As described above, the white light emitting device using the blue LED, the orange phosphor and the yellow phosphor of the present invention emits light in white to light bulb color, and has more red component than the white light emitting device using only the yellow phosphor. It has high color rendering properties and can be suitably used as lighting. Moreover, such a white light emitting device can be suitably used as a backlight of an image display device, particularly a liquid crystal display device.
Table 22 is a characteristic list of white light emitting devices manufactured using the blue LED, the orange phosphor A, and the green phosphor 1.
Table 23 is a characteristic list of white light emitting devices manufactured using the blue LED, the orange phosphor A, and the green phosphor 1. The white light emitting device in Table 23 has a higher mixing ratio of the orange phosphor A than the white light emitting device in Table 22. Thereby, a white light emitting device of a light bulb color can be obtained.
As described above, the light emitting device using the blue LED, the orange phosphor and the green phosphor of the present invention emits light in white to light bulb color, and has a reddish component and a blue-green component as compared with the light emitting device using only the yellow phosphor. Since there are many, color rendering property is very high, and it can use it suitably as illumination. Moreover, such a white light emitting device can be suitably used as a backlight of an image display device, particularly a liquid crystal display device.

Table 24 is a characteristic list of white light emitting devices manufactured using the blue LED, the orange phosphor A, and the green phosphor 2A.
Table 25 is a characteristic list of white light emitting devices manufactured using the blue LED, the orange phosphor A, and the green phosphor 2A. The white light emitting device in Table 25 has a higher mixing ratio of the orange phosphor A than the white light emitting device in Table 24. Thereby, a white light emitting device of a light bulb color can be obtained.
Table 26 is a characteristic list of white light emitting devices manufactured using blue LEDs, orange phosphor A, and green phosphor 2B.
Table 27 is a characteristic list of white light emitting devices manufactured using the blue LED, the orange phosphor A, and the green phosphor 2B. The white light emitting device in Table 27 has a higher mixing ratio of the orange phosphor A than the white light emitting device in Table 26. Thereby, a white light emitting device of a light bulb color can be obtained.
As described above, the white light emitting device using the blue LED, the orange phosphor and the green phosphor of the present invention emits light in white to light bulb color, and has more redness component than the light emitting device using only the yellow phosphor. Therefore, it can be suitably used as illumination because of its high brightness. Moreover, such a white light emitting device can be suitably used as a backlight of an image display device, particularly a liquid crystal display device.

Table 28 is a list of characteristics of white light emitting devices manufactured using near-ultraviolet LEDs, orange phosphor A, green phosphor 2A, and blue phosphor 1.
Table 29 is a list of characteristics of white light emitting devices manufactured using the near ultraviolet LED, the orange phosphor A, the green phosphor 2A, and the blue phosphor 1. The white light emitting device in Table 29 has a higher mixing ratio of the orange phosphor A than the white light emitting device in Table 28. Thereby, a white light emitting device of a light bulb color can be obtained.
Table 30 is a list of characteristics of white light emitting devices manufactured using the near-ultraviolet LED, the orange phosphor A, the green phosphor 2B, and the blue phosphor 1.
Table 31 is a list of characteristics of white light emitting devices manufactured using near-ultraviolet LEDs, orange phosphor A, green phosphor 2B, and blue phosphor 1. The white light emitting device of Table 31 has a higher mixing ratio of the orange phosphor A than the white light emitting device of Table 30. Thereby, a white light emitting device of a light bulb color can be obtained.
As described above, the white light emitting device using the near ultraviolet LED, the orange phosphor, the green phosphor, and the blue phosphor of the present invention emits light in a white to light bulb color and is compared with the white light emitting device using the blue LED. In addition, since the color unevenness is small and the color rendering property is high, it can be suitably used as illumination. Moreover, such a white light emitting device can be suitably used as a backlight of an image display device, particularly a liquid crystal display device.

Furthermore, in the white light emitting device using the blue LED as the first light emitter, the transmission ratio of blue light affects the emission color of the white light emitting device, but when the near ultraviolet LED is used as the first light emitter, Since the emission color of the white light emitting device can be controlled only by the mixing ratio of the phosphors, it is easier to adjust the color tone than when a blue LED is used.
Table 32 is a list of characteristics of light-emitting devices manufactured using near-ultraviolet LEDs and orange phosphor A.
As described above, the light emitting device using the near-ultraviolet LED and the orange phosphor of the present invention emits orange or pink light and has high luminance, and therefore can be suitably used as various display devices and in-vehicle light sources. it can.

It is typical sectional drawing which shows embodiment of the light-emitting device of this invention. It is typical sectional drawing which shows the surface mount-type white light-emitting device produced in Examples 30-154. It is a typical perspective view which shows other embodiment of the light-emitting device of this invention. It is typical sectional drawing which shows an example of the surface emitting illumination apparatus using the light-emitting device of this invention. It is a figure which shows the powder X-ray-diffraction pattern (X-ray source: CuK (alpha)) of the fluorescent substance of Example 1, and the pattern fitting result by Rietveld method. It is the figure which connected the observation data of the fluorescent substance of FIG. 4a with the continuous line. It is a figure which shows the emission spectrum (excitation light wavelength: 460 nm) of the fluorescent substance of Example 1, Reference Example 1, Reference Example 3, and Comparative Examples 1 and 2. It is a figure which shows the emission spectrum (excitation light wavelength: 400 nm) of the fluorescent substance of Example 1, Reference Example 1, Reference Example 3, and Comparative Examples 1 and 2. It is a figure which shows the excitation spectrum (luminescence detection wavelength: 593 nm) of the fluorescent substance of Example 1. 14 is a graph showing an emission spectrum of a white light emitting device manufactured in Example 12. FIG. It is a figure which shows the temperature dependence of the emitted light intensity of the fluorescent substance of Example 1. FIG. It is a figure which shows the relationship between the amount of Eu addition, the light emission peak wavelength, and relative light emission peak intensity in the case of the excitation wavelength of 460 nm of the fluorescent substance in Reference Example 2 and Examples 4-8. 14 is a graph showing an emission spectrum of a white light emitting device produced in Example 41. FIG. 14 is a graph showing an emission spectrum of a white light emitting device produced in Example 54. FIG. FIG. 10 shows an emission spectrum of a white light emitting device produced in Example 86. FIG. 11 shows an emission spectrum of the white light emitting device manufactured in Example 108. 6 is a graph showing an emission spectrum of a white light emitting device manufactured in Example 112. FIG. 6 is a graph showing an emission spectrum of a white light emitting device manufactured in Example 127. FIG. FIG. 10 shows an emission spectrum of a white light emitting device produced in Example 142. FIG. 13 shows an emission spectrum of a white light-emitting device manufactured in Example 144. FIG. 10 shows an emission spectrum of the light-emitting device manufactured in Example 150.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 Frame 2A The recessed part of a frame 3 Blue LED (1st light-emitting body)
DESCRIPTION OF SYMBOLS 4 Fluorescent substance containing part 5 Silver paste 6 Wire 7 Mold part 8 Light-emitting device 9 Substrate 10 Surface emitting GaN-type LD (first light emitting body)
DESCRIPTION OF SYMBOLS 11 2nd light emitter 12 Surface emitting illuminating device 13 Holding case 14 Diffusion plate 21 LED (1st light emitter)
22 Phosphor-containing part 23 Frame 24 Wire 25 Terminal 26 Terminal

Claims (15)

An emission peak wavelength obtained by excitation with light having a wavelength of 455 nm is in a wavelength range of 590 nm or more and 680 nm or less,
A phosphor having a chemical composition represented by the following formula [1B].
Sr _3- xy- Ba _x Eu _y SiO ₅ ... [1B]
(In the formula [1B], x and y represent numbers satisfying 0.5 ≦ x ≦ 1.2, 0.005 ≦ y <1, and 0 <3-xy.) In the formula [1B], the value of y is
0.01 ≦ y ≦ 0.1
The phosphor according to claim 1, wherein: 3. The phosphor according to claim 1, wherein x = 1 in the formula [1B]. The phosphor according to any one of claims 1 to 3 , wherein a substance different from the phosphor is present on the surface. The phosphor according to claim 4 , wherein the substance different from the phosphor is at least one selected from the group consisting of an organic compound, an inorganic compound, and a glass material. The phosphor according to claim 4 , wherein the substance different from the phosphor includes a metal oxide. Different material from the phosphor is 50 wt% 1 wt% or more based on the weight of the phosphor hereinafter in any one of to 4 claims, characterized in that present on the surface of the phosphor 6 The phosphor described. A phosphor-containing composition comprising the phosphor according to any one of claims 1 to 7 and a liquid medium. In a light emitting device including a first light emitter and a second light emitter that emits visible light by irradiation of light from the first light emitter,
The light emitting device, wherein the second light emitter contains at least one of the phosphors according to any one of claims 1 to 7 as a first phosphor. The light emitting device according to claim 9 , wherein the second phosphor includes at least one phosphor having a light emission wavelength different from that of the first phosphor as the second phosphor. The first light emitter has a light emission peak in a wavelength range of 420 nm to 500 nm;
The light emitting device according to claim 10 , wherein the second light emitter contains at least one kind of phosphor having an emission peak in a wavelength range of 490 nm to 560 nm as the second phosphor. . The first light emitter has a light emission peak in a wavelength range of 300 nm or more and 420 nm or less;
The second phosphor, as the second phosphor, has at least one phosphor having an emission peak in a wavelength range of 420 nm to 490 nm and at least one having an emission peak in a wavelength range of 490 nm to 560 nm. The light emitting device according to claim 10 , further comprising a seed phosphor. The light emitting device according to any one of claims 9 to 12 , wherein the light emitting device further includes a sealing material, and a silicone resin is used as the sealing material. An image display device, characterized in that it comprises as a light source a light emitting device according to any one of claims 9 to 13. Lighting apparatus comprising: a light-emitting device according as the light source to any one of claims 9 to 13.

Images