JP2013045896A - Light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a white light-emitting device that emits light having no dullness with vivid color and high rendering properties, and just looks like a solar light source.SOLUTION: In the light-emitting device having a first luminous body 1 emitting light of 350-430 nm, and a second luminous body 4 emitting visible light when irradiated with light from the first luminous body, the second luminous body contains a phosphor having a chemical composition of formula [1], and a phosphor having a chemical composition of formula [2]. SrBaEu(PO)Cl[1](In the formula [1], a and b are numbers satisfying the conditions a+b=5-x and 0.1≤b/(a+b)≤0.6, c, d and x are numbers satisfying the conditions 2.7≤c≤3.3, 0.9≤d≤1.1 and 0.3≤x≤1.2, respectively). M(SiO)Cl:Eu[2]

Description

  The present invention relates to a light emitting device having a halophosphate phosphor and a halosilicate phosphor having a specific chemical composition that generates visible light upon irradiation of light from a semiconductor light emitting element.

  In recent years, in attempts to make white light emitting devices by combining phosphors with near-ultraviolet LEDs, there are problems of color shift due to temperature rise during use, problems with uniformity and clogging when phosphors are filled into LEDs, and lifetime. Problems such as high probability of reduction, phosphors sucking light emitted by phosphors of other colors, cascade excitation occurs, and overall luminous efficiency is reduced. Since it can be remarkably reduced by reducing the number, it has been desired to create a white light emitting device with fewer kinds of phosphors to be filled in the LED.

Actually, JP 2011-576645 A (Patent Document 1) discloses yellow phosphor (Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu and blue phosphor Ca ₅ (PO ₄ ) ₃ (Cl, Br): Eu and a near-ultraviolet LED are disclosed in Japanese Patent Application Laid-Open No. 2009-38348 (Patent Document 2) as yellow phosphor SiO ₂ .0.9 (Ca, Sr) O.0.17SrCl ₂ : Eu. And a blue phosphor (Ca, Mg) ₅ (PO ₄ ) ₃ Cl: Eu and a near-ultraviolet LED are disclosed in JP 2008-274240 A (Patent Document 3) as yellow phosphor SiO ₂ . 9 (Ca, Sr) O.0.17SrCl ₂ : Eu and blue phosphor Sr ₅ (PO ₄ ) ₃ Cl: Eu (hereinafter sometimes abbreviated as “SCA phosphor”) and near-ultraviolet LEDs The combination is disclosed in JP-A-201. The -32340 (Patent Document 4), a yellow phosphor _{(Ca, Sr) 7 (SiO} 3) 6 Cl 2: Eu and a blue phosphor _{(Ca, Mg) 5 (PO} 4) 3 Cl: Eu and near Combinations with ultraviolet LEDs have been proposed. Thus, Patent Documents 1 to 4 disclose white light emitting devices for near-ultraviolet LEDs using two types of phosphors.

The background of the blue phosphor for the near ultraviolet LED necessary for the combination of the near ultraviolet LED, the blue phosphor and the yellow phosphor will be described below.
First, a halophosphate phosphor activated with divalent Eu ²⁺ is generally useful as a phosphor for a fluorescent lamp excited by a mercury vapor resonance line at 254 nm, and in particular, a fluorescence using a mixture of several kinds of phosphors. It was widely used as a blue to blue-green light-emitting component in lamps.

On the other hand, many light emitting devices in which the light emission color of a light emitting diode (LED) or a semiconductor laser diode (LD) is color-converted with a phosphor have been proposed. For example, in Japanese Patent Application Laid-Open No. 2004-253747 (Patent Document 5). Sr ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ is cited as a phosphor that emits blue light when irradiated with light in the 350 to 415 nm region from the LED, and particularly contains Eu as an activator. It is disclosed that when the ratio is high, a large emission intensity, that is, a high emission peak intensity can be obtained by excitation of light near 400 nm.

In addition, many studies have been made on the use of the above-described white light-emitting device in which the LED emission color is color-converted with a phosphor as a backlight light source in a liquid crystal display device or the like. For example, in the international publication 2009/141982 pamphlet (patent document 6), it is the said halophosphate fluorescent substance as blue fluorescent substance which light-emits blue light by receiving the irradiation of the light of 330-410 nm area | region from LED. _{sr 1-x-y-z} Ba x Ca y Eu z) 5 (PO 4) 3 and Cl and the like, by reducing the value of the x and y within a predetermined range, the blue phosphor powder It is described that the spectral width of light is made narrow so as to be suitable for backlight applications.

JP 2011-57664 A JP 2009-38348 A JP 2008-274240 A JP 2011-32340 A JP 2004-253747 A International Publication No. 2009/141982 Pamphlet

In the white light emitting device of the near-ultraviolet LED, which has been proposed so far, and the yellow phosphor (Ca, Sr) ₇ (SiO ₃ ) ₆ Cl ₂ : Eu and the blue SCA phosphor or Ca-based apatite phosphor, Sufficient color rendering and vividness could not be obtained, and it was completely insufficient as white illumination.

  When the present inventors examined the emission spectrum of the halophosphate phosphor (SCA phosphor), which is a blue phosphor for LEDs, the half-value width of the emission peak was small, and it was around 490 nm. It has been found that the light emission luminance is low because it does not have sufficient light emission intensity in the wavelength region, and that is one cause.

  Therefore, when a light-emitting device is formed by combining an SCA phosphor or a Ca-based apatite phosphor as the second light emitter with the first light emitter such as a near-ultraviolet LED, the emission spectrum of the light-emitting device is obtained. In this case, a large valley portion is formed in the wavelength region near 490 nm, and the light emission intensity of the valley portion is insufficient, resulting in a problem that the color rendering property is inferior and the light emitting device has low emission luminance. . This is a problem common not only to SCA phosphors but also to Ca-based apatite phosphors.

Furthermore, when the temperature characteristics of the emission luminance of the SCA phosphor were examined, it was found that the luminance was very low at 100 ° C., which is the temperature range reached during LED operation.
Therefore, in the case where the light-emitting device is combined with the first light-emitting body such as a near-ultraviolet LED and the one containing the SCA phosphor as the second light-emitting body, the temperature of the apparatus rises due to long-term use. There is a problem that the light emitting device has a low light emission luminance and a low color rendering property.

  The present invention has been made to solve the above-described problems of the prior art, and aims to provide a white light emitting device that has high color rendering properties, looks the same as a solar light source, and emits vivid colors without dullness. .

As a result of intensive studies to solve the problems related to the light emission characteristics of the SCA phosphor, the present inventors have obtained a first light emitter that emits light of 350 to 430 nm, and the light emitted from the first light emitter. A phosphor contained in and used in the second light emitter of a light-emitting device having a second light emitter that generates visible light upon irradiation, the following formula [A]:
(Sr, Ca) _a Ba _B Eu _x (PO ₄ ) _c X _d [A]
(In the above formula [A], X is Cl, and c, d and x are 2.7 ≦ c ≦ 3.3, 0.9 ≦ d ≦ 1.1, 0.3 ≦ x ≦ 1.2. And a and b are numbers satisfying the condition of a + b = 5-x and 0.05 ≦ b / (a + b) ≦ 0.6.)
And having a constant ratio of the intensity at the wavelength of 490 nm to the intensity at the emission peak wavelength, the LED has sufficient emission intensity in the wavelength region near 490 nm, and the LED. It has been found that a phosphor having high emission luminance can be obtained in the temperature range reached during operation, and has been proposed previously (see Japanese Patent Application Nos. 2011-40465 and 2011-40466).

  Furthermore, the present inventors have shown that a light-emitting device having a phosphor having the chemical composition of the above formula [A] and a certain halosilicate phosphor as the second light-emitting body has high color rendering properties, no dullness, and vivid colors. As a result, the present invention was reached.

That is, the gist of the present invention is the following [1] to [7].
[1] Second light emission in a light emitting device having a first light emitter that generates light of 350 to 430 nm and a second light emitter that generates visible light by irradiation of light from the first light emitter. A light emitting device characterized in that the body contains a phosphor having a chemical composition of the following formula [1] and a phosphor having a chemical composition of the following formula [2].
_{Sr a Ba b Eu x (PO} 4) c Cl d [1]
(In the above formula [1], a and b are numbers satisfying the conditions of a + b = 5-x and 0.1 ≦ b / (a + b) ≦ 0.6, and c, d and x are respectively 2.7 ≦ c ≦ 3.3, 0.9 ≦ d ≦ 1.1 and 0.3 ≦ x ≦ 1.2.)
_Me (SiO ₃ ) ₆ Cl _f : Eu [2]
(In the above formula [2], M is composed of at least one element selected from the group consisting of Ca, Sr, Mg and Ba, e is a number satisfying 6 ≦ e ≦ 8, and f is 1. It is a number satisfying 8 ≦ f ≦ 2.2.)
[2] The light emitting device according to [1], wherein b and a in the formula [1] are numbers satisfying a condition of 0.16 ≦ b / (a + b) ≦ 0.6.
[3] The light-emitting device according to [1] or [2], wherein x in the formula [1] is 0.45 or more.
[4] The light emitting device according to any one of [1] to [3], wherein the ratio of the total number of moles of Ca and Sr to the number of moles of M in the formula [2] is 90 mole% or more.
[5] Any of [1] to [4], wherein the phosphor having the chemical composition of the formula [1] has a half-value width of an emission peak of 63 nm or more when excited by light of 350 to 430 nm. A light emitting device according to any one of the above.
[6] The light emitting device according to any one of [1] to [5], wherein M in the formula [2] includes Ca and Sr.
[7] An image display device or illumination device comprising the light emitting device according to any one of [1] to [6] as a light source.

  The present invention can provide a light-emitting device that has a high average color rendering index, is dull, and has excellent reproducibility of colorful light emission.

It is a schematic diagram of an example of the light-emitting device of this invention. 3 is an emission spectrum of the halosilicate phosphor of Synthesis Example 2. 2 is an emission spectrum of a white LED produced in Example 1. It is the emission spectrum of FIG. 6 of Unexamined-Japanese-Patent No. 2011-57664 (patent document 1). 2 is an emission spectrum of a white LED produced in Example 2. It is the emission spectrum of FIG. 21 of Unexamined-Japanese-Patent No. 2009-38348 (patent document 2).

Hereinafter, the present invention will be described with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and may be arbitrarily modified without departing from the gist of the present invention. Can be implemented.
In the present specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.

Further, in the phosphor composition formula in this specification, each composition formula is delimited by a punctuation mark (,). In addition, when a plurality of elements are listed separated by commas (,), one or two or more of the listed elements may be included in any combination and composition. For example, the composition formula “(Ba, Sr, Ca) Al ₂ O ₄ : Eu” has “BaAl ₂ O ₄ : Eu”, “SrAl ₂ O ₄ : Eu”, and “CaAl ₂ O ₄ : Eu”. If: the _{"Ba 1-x Sr x Al 2} O 4 Eu ": the _{"Ba 1-x Ca x Al 2} O 4 Eu ": a _{"Sr 1-x Ca x Al 2} O 4 Eu " “Ba _1-xy Sr _x Ca _y Al ₂ O ₄ : Eu” is all shown comprehensively (where 0 <x <1, 0 <y <1, 0 <X + y <1).

In addition, the phosphor in this specification refers to a phosphor having at least a crystal structure in a part thereof.
Moreover, when mentioning the half width of the emission peak of the phosphor in the present specification, the half width means the full width at half maximum of the emission peak in the emission spectrum.

A light emitting device of the present invention is a light emitting device having a first light emitter that generates light of 350 to 430 nm and a second light emitter that generates visible light by irradiation of light from the first light emitter. The second luminous body has the following formula [1]:
_{Sr a Ba b Eu x (PO} 4) c Cl d [1]
(In the above formula [1], a and b are numbers satisfying the conditions of a + b = 5-x and 0.1 ≦ b / (a + b) ≦ 0.6, and c, d and x are respectively 2.7 ≦ c ≦ 3.3, 0.9 ≦ d ≦ 1.1 and 0.3 ≦ x ≦ 1.2.)
The phosphor having the chemical composition of the following formula [2]:
_Me (SiO ₃ ) ₆ Cl _f : Eu [2]
(In the above formula [2], M is composed of at least one element selected from the group consisting of Ca, Sr, Mg and Ba, e is a number satisfying 6 ≦ e ≦ 8, and f is 1. It is a number satisfying 8 ≦ f ≦ 2.2.)
It is characterized by containing a phosphor having the following chemical composition.
Hereinafter, the second light emitter and the phosphor contained therein will be described first, and then the first light emitter, the configuration and light emission characteristics of the light emitting device, the use of the light emitting device, and the like will be described.

[1. Second light emitter]
In the present invention, the second luminous body has a phosphor having the chemical composition of the above formula [1] (hereinafter sometimes referred to as “SBCA phosphor”) and a chemical composition of the formula [2]. It contains a phosphor (hereinafter sometimes referred to as “halosilicate phosphor”). Here, as described above, the second light emitter is a “wavelength converting member” that generates visible light when irradiated with light having a wavelength of 350 to 430 nm from the first light emitter.

[1-1. SBCA phosphor]
[1-1-1. Chemical composition of SBCA phosphor]
In the present invention, the SBCA phosphor contained in the second light emitter is represented by the following formula [1]:
_{Sr a Ba b Eu x (PO} 4) c Cl d [1]
(In the above formula [1], a and b are numbers satisfying the conditions of a + b = 5-x and 0.1 ≦ b / (a + b) ≦ 0.6, and c, d and x are respectively 2.7 ≦ c ≦ 3.3, 0.9 ≦ d ≦ 1.1 and 0.3 ≦ x ≦ 1.2.)
The chemical composition is as follows.
In addition, this fluorescent substance may contain elements other than the above-mentioned to such an extent that the effect of this invention is not impaired. Further, the phosphor may contain other components such as a light scattering material as long as the performance is not impaired.

In the formula [1], a specific amount of Sr element and Ba element is contained from the viewpoints of light emission characteristics, temperature characteristics, and the like. Specifically, the molar ratio a of the Sr element and the molar ratio b of the Ba element are numbers satisfying the conditions of a + b = 5-x and 0.1 ≦ b / (a + b) ≦ 0.6.
The value of b / (a + b) is preferably 0.12 or more, more preferably 0.16 or more, particularly preferably 0.2 or more, and more preferably 0.28 or more. And more preferably 0.34 or more. In particular, when it is 0.16 or more, the half-value width of the emission peak in the emission spectrum suddenly increases, which is advantageous. Further, the value of b / (a + b) is preferably 0.55 or less, more preferably 0.5 or less, and most preferably 0.45 or less.

  When the value of b / (a + b) is too small, the luminance value is low, and when it is too large, when the phosphor and yellow phosphor are combined to form a white light emitting device, the phosphor and yellow There is a tendency that the emission spectra of the phosphors are excessively overlapped, and it is difficult to obtain high emission efficiency.

  In the formula [1], a part of the Sr element may be substituted with a metal element other than the Eu element and the Ba element. Examples of the metal element include Mg element, Ca element, Zn element, and Mn element. Among these, Mg element is most preferable from the viewpoint of luminance. As a substitution amount, even if it is contained in a small amount with respect to the Sr element, it is preferable because it has the same light emission characteristics. The upper limit of the substitution amount is preferably 20 mol% or less, more preferably 15 mol% or less, and most preferably 10 mol% or less with respect to the Sr element. If the replacement amount is too large, the brightness at the temperature during LED operation may not be sufficiently high.

When a metal element other than the above is included as the metal element, the metal element is not particularly limited, but when a metal element having the same valence as that of the Sr element, that is, a divalent metal element is included, crystal growth may be promoted. Therefore, it is desirable. In addition, a small amount of metal element such as monovalent, trivalent, tetravalent, pentavalent, or hexavalent is introduced in that the ionic radius width of elements that can be used is widened and crystals may be easily formed. Also good. As an example, a part of Sr ^{2+ in} the phosphor can be replaced with equimolar Na ⁺ and La ³⁺ while maintaining the charge compensation effect. A small amount of a metal element that can be a sensitizer may be substituted.

  A part of the Cl element in the formula [1] may be substituted with an anion group other than the Cl element as long as the effects of the present invention are not impaired. When a part of the Cl element is substituted with an anion group, the amount of the anion group other than the Cl element is preferably 50 mol% or less, more preferably 30 mol% or less, and more preferably 10 mol% or less. It is particularly preferred that it is 5 mol% or less.

  The Eu molar ratio x in the formula [1] is usually x ≧ 0.3, preferably x ≧ 0.35, more preferably x ≧ 0 from the viewpoint of brightness at the temperature reached during LED operation. .4, more preferably x ≧ 0.45, and most preferably x ≧ 0.5. If the molar ratio x of the emission center Eu is too small, the emission intensity tends to decrease. However, if the value of x is too large, the emission luminance tends to decrease due to a phenomenon called concentration quenching. ≦ 1.2, preferably x ≦ 1.0, more preferably x ≦ 0.9, particularly preferably x ≦ 0.8, still more preferably x ≦ 0.7, and even more preferably x ≦ 0.65, Most preferably, x ≦ 0.55.

Eu as an activator is at least partially present as a divalent cation. In this case, the activator Eu can take a divalent or trivalent valence, but a higher proportion of divalent cations is preferred. Specifically, the ratio of Eu ^{2+ to} the total amount of Eu is usually 80 mol% or more, preferably 85 mol% or more, more preferably 90 mol% or more, particularly preferably 95 mol% or more, and most preferably 100 mol%. It is.

  Eu as an activator may be substituted with at least one metal element selected from the group consisting of Ce, Tb, Sb, Pr, Er and Mn as another activator. Of the above metal elements, only one type may be substituted, or two or more types may be used in combination in any combination and ratio.

  In the formula [1], c and d satisfy 2.7 ≦ c ≦ 3.3 and 0.9 ≦ d ≦ 1.1, respectively, but c is preferably 2.8 ≦ c ≦ 3.2, more preferably 2.9 ≦ c ≦ 3.1, and d is preferably 0.93 ≦ d ≦ 1.07, and more preferably 0.95 ≦ d ≦ 1.05.

[1-1-2. Physical properties of SBCA phosphor]
(Particle size)
The SBCA phosphor in the present invention usually has a fine particle form. Specifically, the volume median diameter _{D 50} is usually 2μm or more, preferably 5μm or more, usually 50μm or less, preferably fine particles of the range of 30 [mu] m.
When the volume median diameter D ₅₀ is too large, for example, tend to dispersibility becomes poor in the resin which is used as a sealing material described later, they tend to be too small and the low luminance.
The volume median diameter D ₅₀ is, for example, obtained by measuring particle size distribution by laser diffraction scattering method, is a value determined from volume-based particle size distribution curve. The median diameter D ₅₀ is in the volume-based particle size distribution curve, the accumulated value refers to the particle size value when the 50%.

(Luminescent color)
The SBCA phosphor in the present invention usually emits blue to blue-green light. That is, it is usually a blue to blue-green phosphor.
The chromaticity coordinates of the fluorescence of the SBCA phosphor are usually (x, y) = (0.10, 0.06), (0.10, 0.36), (0.20, 0.06) and ( 0.20, 0.36), and preferably (x, y) = (0.13, 0.09), (0.13, 0.30), (0.18). , 0.09) and (0.18, 0.30), and more preferably (x, y) = (0.13, 0.09), (0.13, 0 .26), (0.18, 0.09) and (0.18, 0.26). Therefore, in the chromaticity coordinate of the fluorescence of the SBCA phosphor, the chromaticity coordinate x is usually 0.10 or more, preferably 0.13 or more, and usually 0.20 or less, preferably 0.18 or less. On the other hand, the chromaticity coordinate y is usually 0.06 or more, preferably 0.09 or more, more preferably 0.15 or more, most preferably 0.20 or more, and usually 0.36 or less, preferably 0.33. Below, more preferably 0.30 or less.

  The fluorescence chromaticity coordinates can be calculated from an emission spectrum described later. Further, the values of the chromaticity coordinates x and y represent the chromaticity coordinate values in the CIE standard coordinate system of the emission color when excited with light having a wavelength of 410 nm.

(Luminescent characteristics)
The fluorescence spectrum (emission spectrum) emitted from the SBCA phosphor in the present invention is usually 440 nm in terms of the emission peak wavelength of the emission spectrum when excited with light having a wavelength of 410 nm in view of the use as a blue to blue-green phosphor. Above, preferably 450 nm or more, more preferably 445 nm or more, more preferably 460 nm or more, and usually less than 490 nm, preferably 485 nm or less.

  Further, the SBCA phosphor has a half-value width of an emission peak when excited with light having a wavelength of 410 nm, usually 35 nm or more, preferably 40 nm or more, more preferably 60 nm or more, and particularly preferably 75 nm or more. As a result of such a wide half-value width, when a light-emitting device is formed by combining a first light-emitting material such as an LED with the phosphor containing the second light-emitting material, the luminance and color rendering of the light-emitting device. The color and vividness can be improved. In addition, although there is no restriction | limiting in the upper limit of the half value width of a light emission peak, Usually, it is 95 nm or less.

On the other hand, the SBCA phosphor usually has sufficient emission intensity in the wavelength region near 490 nm in the emission spectrum when excited with light having a wavelength of 410 nm. Specifically, assuming that the intensity at the emission peak wavelength is I (peak) and the intensity at the wavelength of 490 nm is I (490 nm), the value of I (490 nm) / I (peak) satisfies the following formula. Here, the intensity at the emission peak wavelength means the emission intensity at the wavelength where the peak top of the emission peak exists.
0.2 ≦ I (490 nm) / I (peak)

  The value on the left side of the above formula is 0.2, preferably 0.3, more preferably 0.45, particularly preferably 0.55, and most preferably 0.85. That is, the value of I (490 nm) / I (peak) is preferably 0.2 or more, more preferably 0.3 or more, more preferably 0.45 or more, particularly preferably 0.55 or more, and 0.85 or more. Is most preferred.

  The value of I (490 nm) / I (peak) is a value characterizing the shape of the emission spectrum, and the larger the value, the greater the value of emission intensity at 490 nm. Therefore, when the value of I (490 nm) / I (peak) is below the above range, the emission intensity in the wavelength region in the vicinity of 490 nm is small, so that the second emission with respect to the first illuminant such as an LED. When a light-emitting device is formed by combining those containing the phosphor as a body, in the emission spectrum of the light-emitting device, a large valley may be formed in the wavelength region near 490 nm. By lacking, there is a possibility that the light emitting device is inferior in luminance, color rendering, and color vividness.

  The emission spectrum is measured using a fluorescence measuring device (manufactured by JASCO Corporation) equipped with a 150 W xenon lamp as an excitation light source and a multichannel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measuring device at room temperature, for example, 25 ° C. Can be done.

  More specifically, the light from the excitation light source is passed through a diffraction grating spectrometer having a focal length of 10 cm, and only the excitation light having a wavelength of 410 nm is 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 spectroscope having a focal length of 25 cm, the emission intensity of each wavelength is measured by a spectrum measuring device in a wavelength range of 300 nm to 800 nm, and a personal computer is used. An emission spectrum is obtained through signal processing such as sensitivity correction. At the time of measurement, the slit width of the light receiving side spectroscope is set to 1 nm.

(Luminance)
The SBCA phosphor in the present invention usually has high emission luminance at room temperature. In addition, the brightness | luminance in this specification refers to what integrated the value of the visibility x light emission intensity in each wavelength in all the wavelength ranges.
In the SBCA phosphor, the ratio of the relative luminance to the luminance of the SCA phosphor [Eu _0.5 Sr _4.5 (PO ₄ ) ₃ Cl] produced by the same method is usually 130% or more, preferably 160% or more. More preferably, it is 210% or more, more preferably 300% or more, still more preferably 400% or more. When the value of b / (a + b) in Formula [1] is set to 0.16 or more, the asymmetry of the peak shape of the emission spectrum increases, and the longer wavelength side becomes significantly broader than the shorter wavelength side of the peak wavelength. As a result, the brightness becomes extremely high.

(Excitation characteristics)
The wavelength of the light for exciting the SBCA phosphor in the present invention (excitation wavelength) varies depending on the composition of the SBCA phosphor, etc., but the excitation wavelength is usually 350 nm or more, preferably 380 nm or more, more preferably 405 nm or more, Moreover, it is 430 nm or less normally, Preferably it is 420 nm or less, More preferably, it is 415 nm or less.

(Intensity temperature characteristics at peak emission wavelength)
The SBCA phosphor in the present invention is usually excellent in temperature characteristics as compared with the SCA phosphor [Eu _0.5 Sr _4.5 (PO ₄ ) ₃ Cl] produced by the same method. Specifically, in an emission spectrum obtained by exciting the phosphor with light having a wavelength of 410 nm at room temperature (about 20 ° C.), the intensity at the emission peak wavelength is I (room temperature), and light with a wavelength of 410 nm is used at a temperature of 80 ° C. In the emission spectrum obtained by excitation, when the intensity at the emission peak wavelength is I (80 ° C.), the value of I (80 ° C.) / I (room temperature) preferably satisfies the following formula.
0.75 ≦ I (80 ° C.) / I (room temperature)
The value on the left side of the above formula is usually 0.75, preferably 0.80, more preferably 0.85, particularly preferably 0.87, and closer to 1, more preferably. That is, the value of I (80 ° C.) / I (room temperature) is preferably 0.75 or more, more preferably 0.80 or more, more preferably 0.85 or more, particularly preferably 0.87 or more, and close to 1. The more preferable. The upper limit of I (80 ° C.) / I (room temperature) is usually 1.

Further, in an emission spectrum obtained by excitation with light having a wavelength of 410 nm at a temperature of 100 ° C., assuming that the intensity at the emission peak wavelength is I (100 ° C.), the value of I (100 ° C.) / I (room temperature) is It is preferable to satisfy.
0.68 ≦ I (100 ° C.) / I (room temperature)
The value on the left side of the above formula is 0.68, preferably 0.70, more preferably 0.72, particularly preferably 0.80, and most preferably 0.84. The closer to 1, the better. That is, the value of I (100 ° C.) / I (room temperature) is preferably 0.68 or more, more preferably 0.70 or more, more preferably 0.72 or more, particularly preferably 0.80, and 0.84. Most preferable, the closer to 1, the more preferable. The upper limit of (100 ° C.) / I (room temperature) is usually 1.

  In particular, the metal element in the constituent elements of the SBCA phosphor is substantially only Sr, Eu and Ba, and the value of b / (a + b) in the formula [1] is 0.16 or more, It can satisfy the formula “0.75 ≦ I (80 ° C.) / I (room temperature)” and the formula “0.68 ≦ I (100 ° C.) / I (room temperature)”. In addition, “the metal element in the constituent elements is substantially only Sr, Eu and Ba” does not mean that the phosphor does not contain any metal element other than Sr, Eu and Ba. Inclusion of metal elements that are unavoidable in the manufacturing process is allowed. For example, a metal element contained as an inevitable impurity in the raw material of the phosphor, or a metal element contained in a container (crucible) used in the firing process and entering the phosphor from the container during firing.

Further, in an emission spectrum obtained by excitation with light having a wavelength of 410 nm at 130 ° C., which is a typical temperature during operation of a high-power LED, when the intensity at the emission peak wavelength is I (130 ° C.), I (130 ° C. ) / I (room temperature) preferably satisfies the following formula.
0.60 ≦ I (130 ° C) / I (room temperature)
The value on the left side of the above formula is 0.60, preferably 0.67, more preferably 0.70, and the closer to 1, the better. That is, the value of I (130 ° C.) / I (room temperature) is preferably 0.60 or more, more preferably 0.65 or more, more preferably 0.70 or more, and the closer to 1, the more preferable. The upper limit of I (130 ° C.) / I (room temperature) is usually 1.

  In the case of measuring the temperature characteristics, for example, a color luminance meter BM5A as a luminance measuring device, a MCPD7000 multichannel equipped with a cooling mechanism by a Peltier element and a heating mechanism by a heater, and a device having a 150 W xenon lamp as a light source. Using a spectrum measuring device (manufactured by Otsuka Electronics Co., Ltd.), it can be measured as follows. Place the cell containing the phosphor sample on the stage, change the temperature stepwise to 20 ° C, 25 ° C, 50 ° C, 75 ° C, 100 ° C, 125 ° C, 150 ° C, 175 ° C to change the surface temperature of the phosphor. Then, the phosphor is excited with light having a wavelength of 410 nm extracted from the light source by the diffraction grating, and the luminance value and the emission spectrum are measured. The emission peak intensity is obtained from the measured emission spectrum. Here, as the measured value of the surface temperature on the excitation light irradiation side of the phosphor, a value corrected using the measured temperature value by the radiation thermometer and the thermocouple is used.

A yellow phosphor M ₇ (SiO ₃ ) ₆ Cl ₂ : Eu that does not absorb blue light and has a broad emission spectrum in the SBCA phosphor having such good temperature characteristics and emission characteristics, that is, a halophosphate blue phosphor. By providing a white light emitting device described later by combining (halosilicate phosphor), it is possible to provide a white light emitting device that has high color rendering properties, looks the same as a solar light source, has no dullness, and emits light vividly. Is possible.

  In the SBCA phosphor, the value of b / (a + b) in the above formula [1] is less than 0.1, the value of x is more than 1.2, and substantially contains Ca element. Things tend to have reduced temperature characteristics. The temperature of 80 ° C. to 100 ° C. is the temperature of the blue phosphor assumed when the white light emitting device is operated. In a white light emitting device for general illumination use, a large current of 500 mA or more may be applied to an excitation LED having a chip size of 1 mm square, and the temperature of the phosphor may reach 100 ° C. at this time.

(Temperature characteristics of luminance)
The SBCA phosphor in the present invention is an SCA phosphor [Eu _0.5 Sr _4.5 (PO ₄ ), which is usually produced in the same manner as the SBCA phosphor at 80 ° C., which is the temperature reached during LED operation. ratio of relative luminance to the luminance of the ₃ Cl] is usually 150% or more, preferably 180% or more, more preferably 250% or more, more preferably 300% or more, particularly preferably 400% or more.

Further, the SBCA phosphor in the present invention is Eu _0.5 Sr _4.5 (which is an SCA phosphor manufactured by the same method as that of the SBCA phosphor at 100 ° C. which is a temperature reached during LED operation. ratio of relative luminance to the luminance of the PO _{4) 3} Cl phosphor, usually 150% or more, preferably 173% or more, more preferably 250% or more, more preferably 300% or more, particularly preferably 400% or more is there. In particular, the metal elements in the constituent elements are substantially only Sr, Eu and Ba, and the value of b / (a + b) in the formula [1] is 0.16 or more, the room temperature of the SCA phosphor The ratio of the relative luminance to the luminance in can be 300% or more at 80 ° C. and 250% or more at 100 ° C.

In addition, the SBCA phosphor is usually produced by the same method as the SBCA phosphor [Eu _0.5 Sr _4.5 (Eu _0.5 Sr _4.5 (at 130 ° C.) which is a typical temperature during operation of the LED power chip. The ratio of the relative luminance to the luminance of PO ₄ ) ₃ Cl] is usually 150% or more, preferably 155% or more, more preferably 250% or more, more preferably 300% or more, and particularly preferably 400% or more. .

[1-1-3. Manufacturing method of SBCA phosphor]
There is no special restriction | limiting in the manufacturing method of SBCA fluorescent substance in this invention, As long as the effect of this invention is not impaired remarkably, it can manufacture by arbitrary methods. However, if a phosphor having a chemical composition represented by the formula [1] (halophosphate phosphor) is produced by the production method described below, the phosphor can usually have the above-described characteristics.

The SBCA phosphor can be produced by firing a mixture of phosphor raw materials prepared to have the composition represented by the above formula [1]. As the phosphor material, a metal compound is usually used. That is, the metal compound as a raw material may be weighed so as to have a predetermined composition, mixed, and fired. For example, when producing a phosphor having the chemical composition of the above formula [1], a raw material of Sr (hereinafter also referred to as “Sr source” as appropriate) and a raw material of Ba (hereinafter referred to as “Ba source” as appropriate). ), Eu raw material (hereinafter also referred to as “Eu source” as appropriate), PO ₄ raw material (hereinafter also referred to as “PO ₄ source” as appropriate), and Cl raw material (hereinafter referred to as “Cl source” as appropriate). May be manufactured by mixing necessary combinations (mixing step) and firing the resulting mixture (firing step).

(Phosphor raw material)
Examples of the phosphor raw materials (that is, Sr source, Ba source, Eu source, PO ₄ source, and Cl source) used in the manufacture of the SBCA phosphor include, for example, Sr, Ba, Eu, PO ₄ , and Cl. And oxides, hydroxides, carbonates, nitrates, sulfates, oxalates, carboxylates, halides and hydrates of these elements. From these compounds, the reactivity to the composite oxynitride, the low generation amount of NO _x , SO _{x and the} like during firing may be selected as appropriate.

Specific examples of the Sr source include oxides such as SrO, hydroxides such as Sr (OH) ₂ .8H ₂ O, carbonates such as SrCO ₃ , and nitrates such as Sr (NO ₃ ) ₂ .4H ₂ O. , Sulfates such as SrSO ₄ , oxalates such as Sr (OCO) ₂ .H ₂ O, Sr (C ₂ O ₄ ) · H ₂ O, and carboxylic acids such as Sr (OCOCH ₃ ) ₂ .0.5H ₂ O Examples thereof include salts, halides such as SrCl ₂ and SrCl ₂ .6H ₂ O, and nitrides such as Sr ₃ N ₂ and SrNH. 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. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

Specific examples of the Ba source include oxides such as BaO, hydroxides such as Ba (OH) ₂ .8H ₂ O, carbonates such as BaCO ₃ , nitrates such as Ba (NO ₃ ) ₂ , BaSO _{4 and the} like. Sulfate, Ba (OCO) ₂ .H ₂ O, carboxylates such as Ba (OCOCH ₃ ) ₂ , halides such as BaCl ₂ , BaCl ₂ .6H ₂ O, nitrides such as Ba ₃ N ₂ and BaNH Etc. Of these, carbonates, oxides and the like can be preferably used. However, carbonates are more preferable from the viewpoint of handling because oxides easily react with moisture in the air. 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. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

Specific examples of Mg, Ca, Zn, and Mn (Mg source, Ca source, Zn source, and Mn source) that may substitute a part of Sr are listed separately as follows.
Specific examples of the Mg source include oxides such as MgO, hydroxides such as Mg (OH) ₂ , carbonates such as basic magnesium carbonate (mMgCO ₃ · Mg (OH ₂ ) · nH ₂ O), Mg ( Nitrates such as NO ₃ ) ₂ · 6H ₂ O, sulfates such as MgSO ₄ , carboxylates such as Mg (OCO) ₂ · H ₂ O, Mg (OCOCH ₃ ) ₂ · 4H ₂ O, halogens such as MgCl ₂ And nitrides such as Mg ₃ N ₂ and MgNH. Of these, MgO and basic magnesium carbonate are preferred. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

Specific examples of the Ca source include oxides such as CaO, hydroxides such as Ca (OH) ₂ , carbonates such as CaCO ₃ , nitrates such as Ca (NO ₃ ) ₂ .4H ₂ O, CaSO ₄ .2H. ₂ O sulfates such _{as, Ca (OCO) 2 · H} 2 O, Ca (OCOCH 3) 2 · H 2 O carboxylates such as halides CaCl _2, etc., nitrides such as _Ca 3 _{N 2,} CaNH Etc. Of these, CaCO ₃ , CaCl _{2 and the} like are preferable. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

Specific examples of Zn source, an oxide such as _ZnO, ZnF 2, ZnCl ₂ or the like halides, Zn _{(OH) 2,} etc. _hydroxides, Zn ₃ N 2, nitrides such ZnNH, such as ZnCO ₃ Zinc compounds such as carbonates, nitrates such as Zn (NO ₃ ) ₂ .6H ₂ O, carboxylates such as Zn (OCO) ₂ and Zn (OCOCH ₃ ) ₂ , sulfates such as ZnSO ₄ (but hydration) It may be a product). 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. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

Specific examples of the Mn source include oxides such as MnO ₂ , Mn ₂ O ₃ , Mn ₃ O ₄ , and MnO, hydroxides such as Mn (OH) ₂ , peroxides such as MnOOH, and carbonates such as MnCO _3. Salts, nitrates such as Mn (NO ₃ ) ₂ , carboxylates such as Mn (OCOCH ₃ ) ₂ .2H ₂ O, Mn (OCOCH ₃ ) ₃ .nH ₂ O, halides such as MnCl ₂ .4H ₂ O, etc. Respectively. Of these, carbonates, oxides and the like can be preferably used. However, carbonates are more preferable from the viewpoint of handling because oxides easily react with moisture in the air. Among these, MnCO 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. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

Specific examples of the PO ₄ source include hydrogen phosphates such as Sr, Ba, and NH ₄ , phosphates, metaphosphates, pyrophosphates, oxides such as P ₂ O ₅ , PCl ₃ , PX ₅ , _{sr 2 PO 4 Cl, Ba 2} PO 4 Cl, phosphoric acid, metaphosphoric acid, and pyrophosphoric acid.

Specific examples of the Cl source include SrCl, BaCl, NH ₄ Cl, HCl, Sr ₂ PO ₄ Cl, Ba ₂ PO ₄ Cl, and the like. Among these, chemical composition, reactivity, and firing Is selected in consideration of non-occurrence of NOx, SOx, etc.

Specific examples of the Eu source include oxides such as Eu ₂ O ₃ , sulfates such as Eu ₂ (SO ₄ ) ₃ , oxalates such as Eu ₂ (C ₂ O ₄ ) ₃ · 10H ₂ O, EuCl ₂ , EuCl ₃ , EuCl ₃ .6H ₂ O, halides, Eu (OCOCH ₃ ) ₃ .4H ₂ O and other carboxylic acids, Eu ₂ (OCO) ₃ .6H ₂ O, Eu (NO ₃ ) ₃ .6H ₂ Examples thereof include nitrates such as O, and nitrides such as EuN and EuNH. Of these, Eu ₂ O ₃ , EuCl _{3 and the} like are preferable, and Eu ₂ O ₃ is particularly preferable.

The Sr source, Ba source, Mg source, Ca source, Zn source, Mn source, PO ₄ source, Cl source, and Eu source described above may each be used alone or in combination of two types. The above may be used in any combination and ratio.

(Mixing process)
Each phosphor raw material is weighed at a predetermined ratio so as to obtain a phosphor having the chemical composition of the formula [1], and sufficiently mixed using a ball mill or the like to obtain a raw material mixture.
Although it does not specifically limit as said mixing method, Specifically, the method of following (A) and (B) is mentioned.

(A) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., or pulverization using mortar and pestle, and mixer such as ribbon blender, V-type blender, Henschel mixer, or mortar and pestle And a dry mixing method in which the above phosphor raw materials are pulverized and mixed.
(B) A solvent or dispersion medium such as water is added to the phosphor material described above, and mixed using, for example, a pulverizer, a mortar and a pestle, or an evaporating dish and a stirring rod, to obtain a solution or slurry. A wet mixing method in which drying is performed by spray drying, heat drying, or natural drying.
The phosphor raw materials may be mixed by either the wet mixing method or the dry mixing method, but a wet mixing method using water or ethanol is more preferable.

(Baking process)
An SBCA phosphor can be manufactured by heat-treating and baking the prepared raw material mixture.
Although there is no restriction | limiting in the specific operation procedure in the case of baking, Usually, the mixture of the raw material obtained at the mixing process is filled into an alumina baking container, and baking is performed in the said baking container. The firing container is not limited to an alumina crucible, and a heat-resistant container such as a crucible or a tray made of a material having low reactivity with each phosphor raw material can be used. Specific examples of the material of the firing container include alumina, ceramics such as boron nitride, silicon nitride, silicon carbide, magnesium, mullite, 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.

As the firing atmosphere, an atmosphere necessary for obtaining an ion state (valence) in which the element of the emission center ion contributes to light emission is selected, and is arbitrary as long as the SBCA phosphor in the present invention is obtained. The atmosphere. As the valence of the activating element contained in the phosphor, it is preferable that the number of divalent ones is larger from the viewpoint of emission intensity. Firing in a reducing atmosphere is preferable because Eu, which was Eu ³⁺ in the phosphor material, is reduced to Eu ²⁺ .

  As a specific example of a gas used for reducing atmosphere (hereinafter referred to as “reducing gas”), hydrogen, carbon monoxide and the like can be used. These gases can be used alone, but are usually used by mixing with an inert gas. Nitrogen, argon, etc. can be used as the inert gas, but hydrogen-containing nitrogen gas is preferred from a practical standpoint.

In a mixed environment of inert gas and reducing gas, the ratio (molar ratio) of reducing gas to the total amount of gas is usually 0.5% or more, preferably 2% or more, more preferably 3% or more. It is. Below this range, the fired product may not be sufficiently reduced by firing.
Moreover, only one type of reducing gas and inert gas may be used, or two or more types may be used in any combination and ratio.
It is possible to select the conditions even in an oxidizing atmosphere such as air or oxygen.

  The firing temperature (maximum temperature reached) is usually 700 ° C. or higher, preferably 900 ° C. or higher, and is usually 1500 ° C. or lower, preferably 1350 ° C. or lower. If the firing temperature is below this range, the carbonate used as the phosphor material may not be oxidatively decomposed. Further, if the firing temperature exceeds this range, the phosphor particles may be fused to become coarse particles.

  The rate of temperature increase is usually 1 ° C./min or more and usually 40 ° C./min or less. If the rate of temperature rise is below this range, the firing time may be long. In addition, if the rate of temperature rise exceeds this range, the firing device, container, etc. may be damaged. The cooling rate is usually 1 ° C./min or more and usually 100 ° C./min or less. If the cooling rate is below this range, the efficiency is industrially inferior. Further, if the temperature lowering rate exceeds this range, an adverse effect on the furnace occurs.

The firing time varies depending on the temperature, pressure and the like during firing, but is usually 1 hour or longer and usually 24 hours or shorter.
The pressure during firing varies depending on the firing temperature and the like and is not particularly limited, but is usually 0.04 MPa or more and usually 0.1 MPa or less. Among these, about atmospheric pressure is industrially preferable in terms of cost and labor.

  The baked product that has been subjected to the above-described firing step can be subjected to post-treatment and the like described later to obtain the SBCA phosphor in the present invention.

  In addition, as described in paragraphs [0133] to [0149] of Japanese Patent Application Laid-Open No. 2009-30042, it is manufactured through multi-stage firing, in which two or more firing steps (primary firing, secondary firing, etc.) are performed. May be. For example, by repeating the firing process a plurality of times, such as primary firing in an oxidizing atmosphere and secondary firing in a reducing atmosphere, a fired product grows, and a phosphor having a large particle size and high luminous efficiency is obtained. Obtainable.

  Moreover, in the above-mentioned firing step, usually, good single particles can be grown by allowing a flux to coexist in the reaction system. In addition, when it manufactures through multistage baking which performs a baking process 2 times or more, the addition effect of a flux is acquired favorably in the 2nd stage and after.

(Post-processing)
In the manufacturing method of the SBCA phosphor in the present invention, other steps may be performed as necessary in addition to the steps described above. For example, after the above baking process, a pulverization process, a cleaning process, a classification process, a surface treatment process, a drying process, and the like may be performed as necessary.

[1-2. (Halosilicate phosphor)
[1-2-1. Chemical composition of halosilicate phosphor]
In the present invention, the halosilicate phosphor contained in the second light emitter is represented by the following formula [2]:
_Me (SiO ₃ ) ₆ Cl _f : Eu [2]
(In the above formula [2], M is composed of at least one element selected from the group consisting of Ca, Sr, Mg and Ba, e is a number satisfying 6 ≦ e ≦ 8, and f is 1. It is a number satisfying 8 ≦ f ≦ 2.2.)
The chemical composition is as follows.

Here, the formula [2] is represented by M _e (SiO ₃ ) ₆ Cl _f : Eu, which is expressed by (SiO ₂ ) · [(e−f / 2) / 6] (MO) · ( f / 12) (MCl ₂ ): Eu can be rewritten. That is, the phosphor having the chemical composition of the formula [2] is represented by the following [3]:
(SiO ₂ ) · p (MO) · q (MCl ₂ ): Eu [3]
(In the above formula [3], M is composed of at least one element selected from the element group consisting of Ca, Sr, Mg and Ba, and p is a number satisfying 0.82 ≦ p ≦ 1.18, q is a number satisfying 0.15 ≦ q ≦ 0.18.)
It is synonymous with a phosphor having the chemical composition of

  M in the above formulas [2] and [3] is composed of at least one element selected from the element group consisting of Ca, Sr, Mg and Ba, but may contain a small amount of Zn or Mn as other elements. . From the viewpoint of luminance, the ratio of the total number of moles of Ca and Sr to the number of moles of M is preferably 90% by mole or more, more preferably 95% by mole or more, and still more preferably 100% by mole. From the point of brightness, the molar ratio of Ca to the total of Ca and Sr is preferably in the range of 0.2 to 0.7, more preferably in the range of 0.3 to 0.55.

  Si contained in the above formulas [2] and [3] is a tetravalent element, but it is possible to substitute a small amount of other tetravalent element Ge because the light emission characteristics are hardly adversely affected. From the viewpoint of luminance, the substitution ratio of Ge to Si is preferably 3 mol% or less, more preferably 1 mol% or less, and still more preferably 0%.

  Cl contained in the above formulas [2] and [3] is a −1 valent element, but it is possible to substitute a small amount of other −1 valent element Br or F because there is almost no adverse effect on the light emission characteristics. It is. From the viewpoint of brightness and cost, the substitution rate of F or Br with respect to Cl is preferably 30 mol% or less, more preferably 10 mol% or less, still more preferably 5 mol% or less, and 0 mol % Is most preferred.

Eu as an activator is at least partially present as a divalent cation. In this case, the activator Eu can take a divalent or trivalent valence, but a higher proportion of divalent cations is preferred. Specifically, the ratio of Eu ^{2+ to} the total amount of Eu is usually 80 mol% or more, preferably 85 mol% or more, more preferably 90 mol% or more, particularly preferably 95 mol% or more, and most preferably 100 mol%. It is.

  Eu as an activator may be substituted with at least one metal element selected from the group consisting of Ce, Tb, Sb, Pr, Er and Mn as another activator. Of the above metal elements, only one type may be substituted, or two or more types may be used in combination in any combination and ratio.

  Regarding features other than the above of the phosphors having the chemical compositions of the formulas [2] and [3], JP 2008-274240 A (Patent Document 3), JP 2009-38348 A (Patent Document 2), Reference can be made to the descriptions in Japanese Patent Application Laid-Open No. 2011-57664 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2011-32340 (Patent Document 4).

[1-2-2. Physical properties of halosilicate phosphors)
The phosphors having the chemical compositions of the above formulas [2] and [3] (halosilicate phosphors) have an excitation band in the short-wavelength side region from near ultraviolet to visible light, and have a wavelength of 560 to around 600. Efficiently emits light having an emission spectrum peak in the wavelength range of 590 nm. Therefore, when this halosilicate phosphor-near ultraviolet LED is combined with a near-ultraviolet-excited blue phosphor, the halosilicate phosphor emits yellow light without absorbing the light of the blue phosphor. A light-emitting device that is hardly dependent on the thickness of the body layer can be formed. The emission wavelength of the present halosilicate phosphor is preferably 580 nm or less and 565 nm or more. The half-value width of the emission peak of the present halosilicate phosphor is as wide as 115 nm or more, which is suitable for a white light emitting device with good color rendering properties. The half width is preferably 120 nm or more, and more preferably 125 nm or more.

[1-2-3. Method for producing halosilicate phosphor]

A method for producing a phosphor having the chemical composition of the above formulas [2] and [3] will be described. Regarding the raw materials to be charged, basically, a plurality of compounds containing the constituent element of the formula [2] are in accordance with the composition ratio (provided that the alkaline earth metal element and the halogen are in an excess amount from the composition ratio of the formula [2]. However, it is preferable to use a mixed material, but more preferably, it is the next charged raw material.
Raw material (1): SiO ₂ .
Raw material (2): Ca, Sr, Mg, or Ba oxide, or a compound that can be converted to the oxide by heating.
Raw material (3): Ca, Sr, Mg, or Ba halide.
Raw material (4): Eu compound.

Specific examples of the Sr source in the raw material (2) include oxides such as SrO, hydroxides such as Sr (OH) ₂ .8H ₂ O, carbonates such as SrCO ₃ , Sr (NO ₃ ) ₂ .4H _2. Nitrates such as O, sulfates such as SrSO ₄ , oxalates such as Sr (OCO) ₂ .H ₂ O, Sr (C ₂ O ₄ ) · H ₂ O, Sr (OCOCH ₃ ) ₂ .0.5H ₂ O And the like. Among these, SrO, Sr (OH) ₂ and SrCO ₃ are preferable. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

Specific examples of the Ca source in the raw material (2) include oxides such as CaO, hydroxides such as Ca (OH) ₂ , carbonates such as CaCO ₃ , and nitrates such as Ca (NO ₃ ) ₂ .4H ₂ O. And sulfates such as CaSO ₄ .2H ₂ O, carboxylates such as Ca (OCO) ₂ .H ₂ O, Ca (OCOCH ₃ ) ₂ .H ₂ O, and the like. Among these, CaO, Ca (OH) ₂ and CaCO ₃ are preferable. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

Specific examples of the Ba source in the raw material (2) include oxides such as BaO, hydroxides such as Ba (OH) ₂ .8H ₂ O, carbonates such as BaCO ₃ , and nitrates such as Ba (NO ₃ ) _2. And sulfates such as BaSO ₄ and carboxylates such as Ba (OCO) ₂ .H ₂ O and Ba (OCOCH ₃ ) ₂ . BaO, Ba (OH) 2 .8H ₂ O, Ba (OH) ₂ , and BaCO ₃ are preferable. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

Specific examples of the Mg source in the raw material (2) include oxides such as MgO, hydroxides such as Mg (OH) ₂ , basic magnesium carbonate (mMgCO ₃ .Mg (OH ₂ ) .nH ₂ O), etc. Carbonates, nitrates such as Mg (NO ₃ ) ₂ .6H ₂ O, sulfates such as MgSO ₄ , carboxylates such as Mg (OCO) ₂ .H ₂ O, Mg (OCOCH ₃ ) ₂ .4H ₂ O, etc. Is mentioned. MgO and basic magnesium carbonate are preferred. When carbonate is used as a raw material, the carbonate may be pre-baked and used as a raw material.

Specific examples of the raw material (3) include SrCl ₂ , SrCl ₂ · 6H ₂ O, MgCl ₂ , MgCl ₂ · 6H ₂ O, CaCl ₂ , CaCl ₂ · 2H ₂ O, BaCl ₂ , BaCl ₂ · 2H ₂ O, _{ZnCl 2, MgF 2, CaF 2} , SrF 2, BaF 2, MgBr 2, CaBr 2, SrBr 2, BaBr 2 , and the like.

Specific examples of the raw material (4) include Eu ₂ O ₃ , Eu ₂ (CO ₃ ) ₃ , Eu (OH) ₃ , EuCl _{3 and the} like.

  The molar ratio of the raw materials (1) to (4) is as follows: Raw material (1): Raw material (2) = 1: 0.25 to 1.0, Raw material (2): Raw material (3) = 1: 0.3 To 4.0, raw material (2): raw material (4) = 1: 0.05 to 3.0, and weighed each raw material into, for example, an alumina mortar and pulverized and mixed to prepare a raw material mixture. obtain. This raw material mixture is placed in, for example, an alumina crucible, placed in an electric furnace, and at a temperature of 700 ° C. to 1200 ° C. under a reducing atmosphere gas such as 4% hydrogen-containing nitrogen gas or nitrogen gas with carbon. Bake for 1 to 40 hours to obtain a fired product. The fired product is sufficiently washed with water or warm water, and the excess chloride is washed away to obtain a phosphor having the chemical composition of the above formulas [2] and [3].

  As described above, the raw material (3) is preferably weighed in an excess amount exceeding the stoichiometric ratio. This is because a part of the halogen element is vaporized and evaporated during firing, and it also serves as a flux for solid-phase reaction. The excessively added raw material exists as an impurity in the manufactured phosphor. By washing away these impurities with water or warm water, a phosphor having high purity and high emission intensity can be obtained.

  In order to obtain a phosphor with high luminous efficiency in this embodiment, it is preferable to reduce the number of metal elements as impurities as much as possible. In particular, since transition metal elements such as Fe, Co, and Ni act as light emission inhibitors, the use of high-purity raw materials and a synthesis process so that the total of these elements is 100 ppm or less, more preferably 50 ppm or less. It is preferable to prevent contamination by impurities.

[1-3. Other phosphors]
The 2nd light-emitting body may contain other fluorescent substance other than the SBCA fluorescent substance and the halosilicate fluorescent substance which were mentioned above in the range which does not impair the effect of this invention. In the present invention, high color rendering properties and vivid colors can be realized only by the combination of the SBCA phosphor and the halosilicate phosphor, but by adding phosphors of other emission colors, higher color rendering properties and vivid colors are possible. It is.

  Specifically, there is no particular limitation as long as it is a substance that is directly or indirectly excited by light emitted from a semiconductor light emitting element (first light emitter) described later and emits light of a different wavelength. Even an organic phosphor can be used. For example, it is preferable to use a green phosphor or a red phosphor as exemplified below, by appropriately adjusting the type and content of the phosphor so that white light having a desired chromaticity coordinate and color temperature can be obtained.

  As the green phosphor, those having an emission peak wavelength of usually 500 nm or more, particularly 510 nm or more, more preferably 515 nm or more, and usually 550 nm or less, especially 542 nm or less, further 535 nm or less are preferred.

_{Specifically, Y 3 (Al, Ga)} 5 O 12: Ce, CaSc 2 O 4: Ce, Ca 3 (Sc, Mg) 2 Si 3 O 12: Ce, (Sr, Ba) 2 SiO 4: Eu Β-sialon, (Ba, Sr) ₃ Si ₆ O ₁₂ : N ₂ : Eu, SrGa ₂ S ₄ : Eu, and BaMgAl ₁₀ O ₁₇ : Eu, Mn are preferable.

  As the red phosphor, those having an emission peak wavelength of usually 600 nm or more, particularly 610 nm or more, further 620 nm or more, and usually 700 nm or less, especially 680 nm or less, and further 660 nm or less are preferable.

Specifically, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Ca, Sr, Ba) AlSi ( _{N, O) 3: Eu,} (Sr, Ba) 3 SiO 5: Eu, (Ca, Sr) S: Eu, (La, Y) 2 O 2 S: Eu, Eu ( _{dibenzoylmethane)} 3 · 1, Β-diketone Eu complex such as 10-phenanthroline complex, carboxylic acid Eu complex, K ₂ SiF ₆ : Mn is preferable, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Sr, Ca) AlSi (N, O): Eu, (La, Y) ₂ O ₂ S: Eu, and K ₂ SiF ₆ : Mn are more preferable.

[1-4. (Usage form and content ratio of phosphor)
When the above-described SBCA phosphor and halosilicate phosphor are used as a second light emitter (wavelength conversion member) in a light emitting device, usually, a phosphor containing another phosphor as necessary. In the form in which the mixture is dispersed in the translucent material together with other components as necessary, that is, in the form of a phosphor-containing composition, light from the first light emitter (semiconductor light emitting device) is irradiated. What is necessary is just to harden | cure after filling in the cup of the package of a light-emitting device as possible.

  As the translucent material that can be used in the phosphor-containing composition, any material may be selected depending on the purpose, as long as the phosphor mixture is suitably dispersed and an undesirable reaction or the like does not occur. Can do. Examples of the translucent material include silicone resin, epoxy resin, polyvinyl resin, polyethylene resin, polypropylene resin, polyester resin, and the like.

  These translucent materials 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 also be contained in said translucent material.

  Examples of other components include silica-based fine powder such as Aerosil and inorganic fine particles such as alumina. 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.

  When a SBCA phosphor and a halosilicate phosphor having a suitable composition are combined with a near-ultraviolet LED to obtain a white light emitting device, the content ratio of the SBCA phosphor and the halosilicate phosphor in the second light emitter is 1: 0. A range of 8 to 2 is preferred, a range of 1: 1 to 1.7 is more preferred, and a range of 1: 1.2 to 1.6 is most preferred. However, the preferred range slightly shifts depending on the Eu concentration in the phosphor and the composition of the alkaline earth metal element species. Within this range, when the weight ratio of the halosilicate phosphor / SBCA phosphor is high, the ratio of yellow light emission to blue light emission is high, and white light having a low color temperature is obtained, and the halosilicate phosphor / SBCA fluorescence is obtained. When the weight ratio of the body is low, the ratio of blue light emission to yellow light emission is high, and white light having a high color temperature is obtained. When adding other luminescent phosphors, for example, when adding a red phosphor, the weight ratio of 0.01 to 0.5 is usually appropriate for the SBCA phosphor. Yes, light bulb color and warm white light with increased reddish components can be obtained. In any case, with the above blending amount, high color rendering properties and colorful light emission can be obtained.

[2. (Light emitting device)
A light emitting device of the present invention is a light emitting device having a first light emitter that generates light of 350 to 430 nm and a second light emitter that generates visible light by irradiation of light from the first light emitter. The second luminous body is characterized in that it contains the above-described SBCA phosphor and halosilicate phosphor.

[2-1. First luminous body]
The first light emitter generates light having a wavelength of 350 to 430 nm. Preferably, light having a peak wavelength is generated in a range of 400 nm or more, more preferably 405 nm or more, further preferably 407 nm or more, preferably 425 nm or less, more preferably 415 nm or less, and further preferably 413 nm or less. In particular, it is preferable to use a GaN-based LED having a peak wavelength in the range of 407 nm or more because of its high luminous efficiency.

As the first light emitter, a semiconductor light emitting element is generally used, and specifically, a light emitting diode (LED), a semiconductor laser diode (LD), or the like can be used.
Among these, as the first light emitter, a GaN LED or LD using a GaN compound semiconductor is preferable. 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. As described in JP-A-6-260681, in an LED having an In _X Ga _Y N light emitting layer, the peak emission wavelength of the LED can be shifted to the longer wavelength side by increasing the value of X. it can. Of the GaN-based LDs, those having a multiple quantum well structure of an In _X Ga _Y N layer and a GaN layer are particularly preferred 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 made of n-type and p-type Al _X Ga _Y N layers, GaN layers, 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.
Known LEDs and LDs can be used. Moreover, only 1 LED or LD may be used, and 2 or more may be used together in arbitrary combinations and ratios.

  In addition, since the SBCA phosphor in the present invention is generally excellent in temperature characteristics as described in the above section (temperature characteristics of emission peak intensity) and (temperature characteristics of emission luminance), the first emission Even when a light-emitting device using a high-power LED, such as a large chip, that can operate at a high output and rises to around 130 ° C. during operation, color shift and decrease in light emission intensity due to heat generation during energization Problems such as are unlikely to occur.

  Moreover, as a large chip, for example, when the outer peripheral shape is a square, the length of one side is usually 500 μm or more, preferably 700 μm or more, more preferably 900 μm or more, and usually 5 mm or less, preferably 3 mm or less. Preferably the thing of 2 mm or less is mentioned.

[2-2. Configuration of light emitting device
For example, as shown in FIG. 1, a light emitting device of the present invention includes a first light emitter (semiconductor light emitting element) 1, a resin molded body 2, a bonding wire 3, a second light emitter (wavelength conversion unit) 4, a lead frame. It consists of 5 etc. In the present specification, a material made of a conductive material such as the lead frame 5 and an insulating resin molding may be referred to as a package.

  The first light emitter (semiconductor light emitting device) 1 is a near ultraviolet semiconductor light emitting device that generates light having a wavelength of 350 to 430 nm (wavelength in the near ultraviolet region). Although only one semiconductor light emitting element is mounted in FIG. 1, a plurality of semiconductor light emitting elements can be arranged in a linear shape or a planar shape. By arranging the first light emitter (semiconductor light emitting element) 1 in a planar shape, surface illumination can be obtained, and such an embodiment is suitable when it is desired to further increase the output.

  The resin molded body 2 constituting the package may be molded together with the lead frame 5. The shape of the package is not particularly limited, and may be a planar type or a cup type.

  The lead frame 5 is made of a conductive metal, and plays a role of supplying power from outside the light emitting device and energizing the first light emitter (semiconductor light emitting element) 1.

  The bonding wire 3 has a role of fixing the first light emitter (semiconductor light emitting element) 1 to the package. When the first light emitter (semiconductor light emitting element) 1 is not in contact with the lead frame as an electrode, the conductive bonding wire 3 supplies power to the first light emitter (semiconductor light emitting element) 1. Play the role of The bonding wire 3 is bonded to the lead frame 5 by applying pressure and applying heat and ultrasonic vibration.

  The resin molded body 2 constituting the package is mounted with a first light emitter (semiconductor light emitting element) 1 and sealed with a second light emitter (wavelength conversion member) 4 mixed with a phosphor.

  As described above, the component contained in the second light-emitting body 4 for dispersing the phosphor may be appropriately selected from translucent resins that are generally used for sealing materials. Examples of the resin include an epoxy resin, a silicone resin, an acrylic resin, and a polycarbonate resin, and it is preferable to use a silicone resin.

  The phosphor in the second light emitter converts the excitation light (350 to 430 nm light) from the first light emitter (semiconductor light emitting element) 1 and emits visible light having a wavelength different from that of the excitation light.

[2-3. (Luminescent characteristics)
The light emitting device of the present invention has a high average color rendering index, can generate bright light without dullness, and has excellent light emission reproducibility.

  Here, the color rendering index is the amount of deviation between the reference light and the sample light source light defined by JIS for a total of 15 test colors of average color rendering evaluation colors (8 types) and special color rendering evaluation colors (7 types). This is a number (JIS Z 8726 “Method for evaluating color rendering properties of light source”). When viewed with the reference light, “100” is assumed, and the numerical value decreases as the color shift when viewed with the sample light source light increases. In other words, a light source (light emitting device) having a good color rendering property has a large color rendering index, and a light source (light emitting device) having a “bad” color rendering property has a small color rendering index.

  The color rendering index includes an average color rendering index (Ra) and special color rendering indices (R9 to R15). Generally, the average color rendering index (Ra) is used as an evaluation index for color rendering. The average color rendering index is an average value of deviation between “reference light” and “sample light source light” in the average color rendering evaluation colors from No1 to No9.

  The average color rendering index in the light emitting device of the present invention is usually 83 or more, preferably 87 or more, more preferably 90 or more. The average color rendering index is preferably closer to 100, but the practical upper limit is about 97 or less.

  As described above, the color rendering index is an index that is evaluated based on a deviation from the color viewed with the reference light (light close to sunlight) defined by JIS, and thus is not a perfect evaluation index for the appearance of the color of an object. .

  A new standard CQS (color quality scale) proposed by the National Institute of Standards and Technology in the United States regarding the color appearance of an object is considered to be a better standard than the conventional average color rendering index, and is being adopted around the world. Details of this CQS are described in Davis and Y. Ohno, Optical Engineering, 49 (2010) 033602.

As shown in the following formulas (a) to (c), the CQS is a solar light source and a sample light source for 15 types of color tables (i = 1, 2,... (Substantially)... 15) having different spectral reflectances. Object color (L ^* , a ^* , b ^* object color of the color system specified by the International Commission on Illumination (CIE) 1976) L ^* , a ^* , b ^*

CQS = 10M _ccT ln (exp (9−0.31 (average value of 15 ΔE _i ^* ))) Formula (a)
When the saturation of the sample light source ≤ the saturation of the solar light source:
ΔE _i ^* = √ ((ΔL _i ^* ) ² + (Δa _i ^* ) ² + (Δb _i ^* ) ² ) Formula (b)
Sample light source saturation> solar light source saturation:
ΔE _i * = √ ((ΔL _i ^* ) ² + (Δa _i ^* ) ² + (Δb _i ^* ) ² − (ΔC _i ^* ) ² ) Formula (c)

Here, in the formulas (a) to (c), M _ccT is a temperature coefficient, and ΔL _i ^* , Δa _i ^* , Δb _i ^* , and ΔC _i ^* are obtained when the i-th color table is used, respectively. The difference between L _i ^* , the difference between a _i ^* , the difference between b _i ^* , and the difference between C _i ^* between the solar light source and the sample light source. C _i ^* is √ ((a _i ^* ) ² + (b _i ^* ) ² ), which is saturation.

When the saturation of the sample light source is smaller than the saturation of sunlight, the deviation of the color appearance is “√ ((ΔL _i ^* ) ² + (Δa _i ^* ) ² + (Δb _i ^* ) ² )”. As expressed, as can be seen from the equations (a) and (b), the CQS is defined to be smaller as the deviation is larger. When there is a difference in lightness L ^* , a ^* , or b ^* between the sample light source and the solar light source, it is defined that the CQS value is lowered by that amount. The color rendering index is not much different.

On the other hand, when the saturation of the sample light source exceeds the saturation of sunlight, as can be seen from the equations (a) and (c), all of the differences in lightness L ^* , a ^* , and b ^* The definition is such that the CQS is reduced by the amount obtained by subtracting the difference in saturation from the amount combined in the mathematical formula.

  That is, according to the definition of CQS, when the saturation of the sample light source exceeds the saturation of the solar light source, it cannot be considered that the appearance of the object has deteriorated due to the discrepancy, and it is not considered good or bad. Is CQS, which is different from the average color rendering index. In other words, the average color rendering index is anyway a measure of how it looks the same as with a solar light source. On the other hand, the CQS is a scale that takes into consideration both “how much it looks the same as in the case of a solar light source” and “whether it is more vivid than in the case of a solar light source”. Although it looks similar to the case of a solar light source, if it is dull, it often does not look comfortable to humans, and the CQS scale has solved this problem.

  The CQS in the light emitting device of the present invention is usually 84 or more, preferably 87 or more, more preferably 90 or more. Although an upper limit is not specifically limited, Usually, it is 97 or less.

[2-4. 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. As described above, the light emitting device of the present invention has a high average color rendering index, generates vivid light without dullness, and is excellent in light emission reproducibility. It is particularly preferably used as a light source. The illumination device and the image display device can be manufactured by a member or method known per se, except that the light emitting device of the present invention is used as a light source.

Hereinafter, the present invention will be described more specifically with reference to experimental examples. However, the present invention is not limited to the following experimental examples, and may be arbitrarily modified and implemented without departing from the scope of the present invention. Can do. The values of various conditions and evaluation results in the following examples have meanings as preferred values of the upper limit or lower limit in the embodiments of the present invention, and the preferred range is the value of the upper limit or lower limit described below. It may be a range defined by a combination of values of the examples or values between the examples.
Moreover, the measurement of the light emission characteristics and the like of the phosphors of the experimental examples was performed by the following method.

[Chemical analysis]
The chemical analysis was performed by a fluorescent X-ray method using a total amount dissolved in alkali or the like.

[Emission spectrum]
The emission spectrum was measured using a 150 W xenon lamp as an excitation light source and a fluorescence measuring device (manufactured by JASCO Corporation) equipped with a multichannel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measuring device. 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 410 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 spectroscope having a focal length of 25 cm, the emission intensity of each wavelength is measured by a spectrum measuring device in a wavelength range of 300 nm to 800 nm, and a personal computer is used. An emission spectrum was obtained through signal processing such as sensitivity correction. During the measurement, the slit width of the light receiving side spectroscope was set to 1 nm and the measurement was performed.

[Chromaticity coordinates]
The chromaticity coordinates of the x, y color system (CIE 1931 color system) are obtained from the data in the wavelength region of 380 nm to 780 nm of the emission spectrum obtained by the above-mentioned method, according to JIS Z8724. The chromaticity coordinates x and y in the prescribed XYZ color system were calculated.

[Temperature characteristics]
The temperature characteristics are measured using an MCPD7000 multi-channel spectrum measurement device (manufactured by Otsuka Electronics Co., Ltd.) as an emission spectrum measurement device, a color luminance meter as a luminance measurement device, a stage equipped with a cooling mechanism using a Peltier element and a heating mechanism using a heater, and 150 W as a light source. The following procedure was performed using an apparatus equipped with a xenon lamp.

  Place the cell containing the phosphor sample on the stage, and change the set temperature step by step to about 20 ° C, 25 ° C, 50 ° C, 75 ° C, 100 ° C, 125 ° C, 150 ° C, 175 ° C. After confirming the surface temperature, the phosphor was excited with light having a wavelength of 410 nm extracted from the light source with a diffraction grating, and the luminance value and the emission spectrum were measured. The emission peak intensity was determined from the measured emission spectrum. Here, as a measured value of the surface temperature on the excitation light irradiation side of the phosphor, a value corrected using a measured temperature value by a radiation thermometer and a thermocouple was used.

[CQS (color quality scale)]
It was obtained by inputting numerical data of the emission spectrum into calculation software programmed based on the above paper (Davis and Y. Ohno, Optical Engineering, 49 (2010) 033602). Specifically, the emission spectrum in the range of 380 nm to 780 nm was obtained by inputting a numerical value of each intensity every 5 nm.

Synthesis Example 1 [Production of SBCA phosphor (1)]
SrHPO ₄ (manufactured by Shirotatsusha), SrCO ₃ (Rare Metallic Co. 99.99 +%), BaCO ₃ (Rare Metallic _{Co., 99.99 +%), SrCl 2} · 6H 2 O ( Wako Pure Chemical Industries, Ltd., 99 0.9%), BaCl ₂ · 6H ₂ O (manufactured by Wako Pure Chemical Industries, special grade), and Eu ₂ O ₃ (rare metallic, 99.99%), in a molar ratio of 3: 0.55: 0. After grinding and mixing in an agate mortar with ethanol so as to be 45: 1: 0: 0.25, and drying, 4.0 g of the obtained pulverized mixture was charged with 4% hydrogen in an alumina crucible. The phosphor Eu _0.50 Sr _4.05 Ba _0.45 (PO ₄ ) ₃ Cl is manufactured by heating at 1200 ° C. for 3 hours under a nitrogen gas flow containing hydrogen, followed by washing with water and drying. did. In addition, among the preparations, 0.5 mol of “SrCl ₂ + BaCl ₂ ” is excessively charged as a flux. The composition formula corrected by chemical analysis is Eu _0.50 Sr _4.05 Ba _0.45 (PO ₄ ) ₃ Cl [b / (a + b) = 0.10, substitution amount of Ca element to Sr element = 0 mol %, X = 0.50].

  Further, in this synthesis example, in order to mix the raw material compounds, mixing was performed by a wet mixing method using ethanol as a solvent, but this method is not limited to this method as long as the raw material compounds can be sufficiently mixed. In addition, a phosphor having the same performance can be obtained by either a wet mixing method using water as a solvent or a dry mixing method.

  Table 1 shows emission characteristics (relative luminance, half-value width of emission peak, etc.) when this phosphor is excited at 410 nm, which is the main wavelength of the GaN-based light emitting diode.

Comparative Synthesis Example 1 [Production of SCA phosphor]
In Synthesis Example 1, the charge molar ratio of SrHPO ₄ , SrCO ₃ , BaCO ₃ , SrCl ₂ .6H ₂ O, BaCl ₂ .6H ₂ O, Eu ₂ O ₃ was set to 3: 1: 0: 1: 0: 0.25. Except for the above, an experiment was performed in the same manner as in Synthesis Example 1 to obtain a phosphor containing no Ba (SCA phosphor). The composition formula corrected by chemical analysis is Eu _0.50 Sr _4.50 (PO ₄ ) ₃ Cl [b / (a + b) = 0, the substitution amount of Ca element with respect to Sr element = 0 mol%, X = 0. 50]. The emission characteristics are shown in Table 1.

  From Table 1, the phosphor of Synthesis Example 1 (SBCA phosphor) has a relative luminance of 187 for 100 and a half-value width of emission peak of 31 compared to the phosphor of Comparative Synthesis Example 1 (SCA phosphor). It turns out that it is as high as 36. This is because the emission peak broadens to the longer wavelength side by containing Ba element. In addition, the SBCA phosphor of Synthesis Example 1 in which the value of b / (a + b) is 0.10 is comparatively synthesized without containing the Ba element because the emission peak is broadened to the long wavelength side by containing the Ba element. When compared with the SCA phosphor of Example 1, the emission peak wavelength was hardly changed, but the value of I (490 nm) / I (peak) was twice or more.

  Since the phosphor of Synthesis Example 1 has a luminance that is 87% higher than that of Comparative Synthesis Example 1, the phosphor of Synthesis Example 1 is used instead of the SCA phosphor to emit light from an LED or the like. When a light-emitting device is combined with a body, it is considered that the light-emitting device has high luminance and excellent color rendering properties.

Synthesis Example 2 [Production of halosilicate phosphor]
As raw materials for the phosphor, SiO ₂ , Ca (OH) ₂ , SrCl ₂ .6H ₂ O, and Eu ₂ O ₃ are mixed with pure water at a molar ratio of 6: 2.454: 5.454: 0.709. Then, the mixture was sufficiently pulverized and mixed with an alumina mortar and an alumina pestle and dried. The obtained raw material mixture was filled in an alumina crucible, an alumina crucible provided with carbon beads in the vicinity thereof was introduced into a muffle furnace, and baked by heating at 1080 ° C. for 5 hours. Subsequently, phosphor Ca _2.69 Sr _3.71 Eu _0.6 (SiO ₃ ) ₆ Cl ₂ : Eu _0.7 was produced by pulverization, water washing, and drying. The emission spectrum of this halosilicate phosphor when excited at 400 nm is shown in FIG. The emission peak wavelength was 577 nm, and the half width of the emission peak was 127 nm. This phosphor is referred to as “phosphor 1”.

Synthesis Example 3 [Production of SBCA phosphor (2)]
SrHPO ₄ , SrCO ₃ , BaCO ₃ , SrCl ₂ .6H ₂ O, BaCl ₂ , and Eu ₂ O ₃ in a molar ratio of 3: 0.5: 0.5: 0.5: 0.5: 0.5 And then ground, mixed and dried in an alumina mortar. The obtained raw material mixture was fired in an alumina crucible under a nitrogen gas flow containing hydrogen. Subsequently, phosphor Eu _0.5 Sr _3.78 Ba _0.72 (PO ₄ ) ₃ Cl was produced by grinding, sieving, washing with water, and drying. In addition, among the preparations, 0.5 mol of “SrCl ₂ + BaCl ₂ ” is excessively charged as a flux. This phosphor is referred to as “phosphor 2”. The emission characteristics of this phosphor were equivalent to the emission characteristics shown in Table 2 of Experimental Example 3 of the specification of Japanese Patent Application No. 2011-40465 previously proposed.

Example 1 [Production and Evaluation of White LED (1)]
Said fluorescent substance 1 and 2 were mixed in the weight ratio of 100: 73 in sealing material silicone resin (Shin-Etsu Chemical Co., Ltd. SCR-1016). The obtained mixed liquid was filled in a near-ultraviolet LED chip, and was heated and cured to obtain a surface-mounted white light emitting device.

  The emission spectrum when a current of 20 mA is applied to the produced white LED is shown in FIG. The light emitting device obtained had a chromaticity coordinate x value of 0.343, a chromaticity coordinate y value of 0.363, a color temperature of 5112K, an average color rendering index of 87, and CQS87. In addition, each color rendering index R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14 are 85, 96, 93, 83, 87, 97, 87, respectively. 71, 24, 90, 80, 96, 88, 96.

Comparative Example 1
In Example 9 (paragraphs [0064] to [0065]) of Japanese Patent Application Laid-Open No. 2011-57664 (Patent Document 1), yellow-emitting halosilicate phosphors (Ca, Sr, Eu) ₇ (SiO ₃ ) ₆ Cl ₂ describes a light emitting device in which a blue light emitting phosphor Ca ₅ (PO ₄ ) ₃ (Cl, Br): Eu and an LED element (peak wavelength 405 nm) are combined. Example 9 corresponds to Example 9 in which the phosphor 2 (SBCA phosphor) is replaced with Ca ₅ (PO ₄ ) ₃ (Cl, Br): Eu.

  An emission spectrum obtained by applying a current of 20 mA to this light emitting device is shown in FIG. 6 of Patent Document 1 (this emission spectrum is presented as FIG. 4). Table 4 (paragraph [0065]) describes chromaticity coordinate x value 0.340, chromaticity coordinate y value 0.327, color temperature (Tcp) 5179K, and average color rendering index (Ra) 83.4. Yes.

  The emission spectrum of Example 9 (FIG. 4 of the present application) was digitized by processing with commercially available image digitizing software (digitizer), and numerical analysis of the emission spectrum was performed. As a result, the chromaticity coordinate x value, chromaticity coordinate y value, color temperature, and average color rendering index were reproduced as 0.340, 0.327, 5179K, and 83, respectively, and each color rendering index R1. , R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14 are 83, 91, 92, 77, 82, 85, 84, 69, 19, 75, respectively. 69, 75, 84, and 96, and CQS was 75.

Example 2 [Production and Evaluation of White LED (2)]
By filling the phosphors 1 and 2 in a weight ratio of 100: 67 in a sealing material silicone resin (SCR-1016 manufactured by Shin-Etsu Chemical Co., Ltd.) in a near-ultraviolet LED chip, and heating to cure. A surface-mount white light emitting device was obtained.

  An emission spectrum when a current of 20 mA is applied to the produced white LED is shown in FIG. The light emitting device obtained had a chromaticity coordinate x value of 0.362, a chromaticity coordinate y value of 0.373, a color temperature of 4522K, an average color rendering index of 86, and CQS87. In addition, each color rendering index R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14 is 82, 91, 97, 84, 85, 91, 90, respectively. , 70, 18, 80, 80, 78, 83, 98.

Comparative Example 2
In Example 2d (paragraphs [0106], [0109] to [0110], [Table 5]) of JP 2009-38348 A (Patent Document 2), yellow phosphor SiO ₂ .0.9 (Ca _{0 .6} , Sr _0.4 ) O.0.17SrCl ₂ : Eu _0.1 [(Ca, Sr, Eu) ₇ (SiO ₃ ) ₆ Cl ₂ ] and blue phosphor (Ca _4.67 Mg _0.5 ) A light emitting device is described that combines (PO ₄ ) ₃ Cl: Eu _0.08 and a near-ultraviolet LED chip (peak wavelength 405 nm). From Table 5 of Patent Document 4, it can be seen that the average color rendering coefficient (Ra) is the highest in this light emitting device. In addition, Example 2d corresponds to Example 2d in which the phosphor 2 (SBCA phosphor) is replaced with (Ca _4.67 Mg _0.5 ) (PO ₄ ) ₃ Cl: Eu _0.08. To do.

  An emission spectrum obtained by applying a current of 10 mA to this light-emitting device is shown in FIG. 21 of Patent Document 2 (a diagram of this emission spectrum is submitted as FIG. 6). Table 5 describes a chromaticity coordinate x value of 0.35, a chromaticity coordinate y value of 0.33, a color temperature of 4522K, and an average color rendering coefficient (Ra) of 83.9.

  The emission spectrum of Example 2d (FIG. 6 of the present application) was digitized by processing with commercially available image digitizing software (digitizer), and the emission spectrum was numerically analyzed. As a result, the chromaticity coordinate x value, the chromaticity coordinate y value, the color temperature, and the average color rendering index were reproduced as 0.35, 0.33, 4511K, and 83, respectively, and the respective color rendering index R1 and R2 , R3, R4, R5, R6, R7, R8, R9, R10, R11, R12, R13, R14 are 83, 94, 93, 74, 82, 86, 83, 68, 25, 81, 66, respectively. 73, 86, and 97, and CQS was 76.

The results of numerical analysis of the emission spectra of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 2 above. As is apparent from Table 2, the results of Example 1 and Comparative Example 1 and Example 2 and Comparative Example 2 which were compared by matching the color temperature of white light showed that the yellow halosilicate phosphor / blue (Sr, Ba) ) ₅ (PO ₄ ) ₃ Cl: Eu phosphor combination is a known yellow halosilicate phosphor / blue Ca ₅ (PO ₄ ) ₃ (Cl, Br): Eu or (Ca, Mg) ₅ (PO ₄ ) ) ₃ Cl: Eu than phosphor combination of a high color rendering properties, it can be seen that the CQS is significantly higher.

  The application of the light emitting device of the present invention is not particularly limited and can be used in various fields. The SBCA phosphor in the present invention is suitable for the purpose of realizing a general illumination phosphor that is excited by a light source such as a near-ultraviolet LED because it has a large half-value width of an emission peak and excellent temperature characteristics. In addition, the light emitting device of the present invention using the SBCA phosphor having the above-described characteristics can be used in various fields where a normal light emitting device is used, but particularly as a light source of an image display device or a lighting device. Preferably used.

1 1st light-emitting body (semiconductor light-emitting device)
2 Resin molded body 3 Bonding wire 4 Second light emitter (wavelength conversion member)
5 Lead frame

Claims (7)

In a light-emitting device including a first light emitter that generates light of 350 to 430 nm and a second light emitter that generates visible light by irradiation of light from the first light emitter, the second light emitter includes: A light-emitting device comprising a phosphor having a chemical composition of the following formula [1] and a phosphor having a chemical composition of the following formula [2].
_{Sr a Ba b Eu x (PO} 4) c Cl d [1]
(In the above formula [1], a and b are numbers satisfying the conditions of a + b = 5-x and 0.1 ≦ b / (a + b) ≦ 0.6, and c, d and x are respectively 2.7 ≦ c ≦ 3.3, 0.9 ≦ d ≦ 1.1 and 0.3 ≦ x ≦ 1.2.)
_Me (SiO ₃ ) ₆ Cl _f : Eu [2]
(In the above formula [2], M is composed of at least one element selected from the group consisting of Ca, Sr, Mg and Ba, e is a number satisfying 6 ≦ e ≦ 8, and f is 1. It is a number satisfying 8 ≦ f ≦ 2.2.)   2. The light emitting device according to claim 1, wherein b and a in the formula [1] are numbers satisfying a condition of 0.16 ≦ b / (a + b) ≦ 0.6.   X in Formula [1] is 0.45 or more, The light-emitting device of Claim 1 or 2 characterized by the above-mentioned.   4. The light emitting device according to claim 1, wherein the ratio of the total number of moles of Ca and Sr to the number of moles of M in the formula [2] is 90% by mole or more.   The phosphor having the chemical composition represented by the formula [1] has a half-value width of an emission peak of 63 nm or more when excited by light having a wavelength of 350 to 430 nm. Light-emitting device.   The light emitting device according to any one of claims 1 to 5, wherein M in the formula [2] is composed of Ca and Sr.   An image display device or a lighting device comprising the light-emitting device according to claim 1 as a light source.