JP2017179082A - Phosphor, light emitting device, lighting device, and image display device - Google Patents

Abstract

The present invention provides an Mn-activated fluoride phosphor excellent in durability. In addition, the present invention provides a light emitting device that is excellent in luminous efficiency and does not change with time in emitted color, and a high-quality lighting device and image display device. A phosphor containing a crystal phase containing Mn, A element, D element, and F, and an integral value of a molecular weight of 18 in a range of 200 ° C. or more and 600 ° C. or less measured by TPD-MS analysis is 50 μmol / A phosphor characterized by being g or less. (However, the A element represents one or more elements selected from the group consisting of alkali metal elements, and the D element represents one or more elements selected from the group consisting of Si, Ge, Sn, Ti, Zr. .) [Selection figure] None

Description

  The present invention relates to a phosphor, a light emitting device, a lighting device, and an image display device.

  A light-emitting device that emits white light (hereinafter referred to as “LED” as appropriate) by using a phosphor together with an excitation light source that emits light in the near-ultraviolet or short-wavelength visible range has become common and has been put to practical use in image display devices and illumination devices. ing. In particular, a phosphor that emits red fluorescence (hereinafter referred to as “red phosphor” as appropriate) is used in a light-emitting device for an image display device or a lighting device, and its light emission characteristics are variously improved. Among these, in order to achieve both the efficiency of the light emitting device and the color rendering properties, development of a phosphor having a narrow half-value width in a specific wavelength band is regarded as important.

In order to realize both high efficiency and color rendering properties of the image display device and the lighting device, for example, the emission peak wavelength of the emission spectrum is 590 nm or more and less than 780 nm, and the half width of the emission spectrum is 1 nm or more and 130 nm or less. It is effective to use a red phosphor. Therefore, red phosphors having the above-mentioned light emission characteristics have been developed.
As such a phosphor, for example, Patent Document 1 discloses a Mn-activated fluoride phosphor such as a fluorogermanate phosphor and K ₂ SiF ₆ : Mn ⁴⁺ (KSF phosphor).

Further developments have been made with respect to the KSF phosphor. For example, Patent Document 2 discloses a KSF phosphor in which the phosphor surface is coated with a matrix that does not contain an activating element such as Mn.
Patent Document 3 discloses a KSF phosphor having a surface region in which the concentration of Mn ⁴⁺ is lower than the inner region of the phosphor.

U.S. Pat. No. 8,810,487 Special table 2014-514388 gazette Japanese Patent Laying-Open No. 2015-28148

However, the phosphors described in Patent Documents 1 to 3 sometimes have insufficient durability of the phosphor. If the durability of the phosphor is not sufficient, the light emission efficiency and the light emission color may change over time when used as a light emitting device.
As for the durability of the phosphor, in addition to performing surface treatment on the phosphor as in Patent Documents 2 and 3, it has been studied to devise the structure of the light-emitting device, but a light-emitting device with further excellent performance is required. Has been. For this reason, a phosphor having higher durability is desired.

  In view of the above problems, the present invention provides a Mn-activated fluoride phosphor excellent in durability. In addition, the present invention provides a light emitting device that is excellent in luminous efficiency and does not change with time in emitted color, and a high-quality lighting device and image display device.

As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by using a phosphor having a moisture content of a specific value or less and reached the present invention.
That is, the present invention is a phosphor containing a crystal phase having Mn, A element, D element and F,
PD (Temperature Programmed Desorption) -phosphor, light-emitting device characterized by an integral value of molecular weight 18 in a range of 200 ° C. or more and 600 ° C. or less measured by MS analysis being 50 μmol / g or less, It exists in a lighting device and an image display device.
(However, the A element represents one or more elements selected from the group consisting of alkali metal elements,
The D element represents one or more elements selected from the group consisting of Si, Ge, Sn, Ti, and Zr. )

  The present invention can provide a Mn-activated fluoride phosphor excellent in durability. In addition, the present invention can provide a light emitting device that is excellent in light emission efficiency and does not change with time in emitted color, and a high-quality lighting device and image display device.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.
In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In the composition formulas of the phosphors 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 “(Ca, Sr, Ba) Al ₂ O ₄ : Eu” has “CaAl ₂ O ₄ : Eu”, “SrAl ₂ O ₄ : Eu”, and “BaAl ₂ O ₄ : Eu”. “Ca _1−x Sr _x Al ₂ O ₄ : Eu”, “Sr _1−x Ba _x Al ₂ O ₄ : Eu”, “Ca _1−x Ba _x Al ₂ O ₄ : Eu”, _{"Ca 1-x-y Sr x} Ba y Al 2 O 4: Eu " and all assumed to generically indicated (in the above formula, 0 <x <1,0 <y <1,0 <X + y <1).

{About phosphor}
The phosphor of the present invention includes a crystal phase having Mn, A element, D element and F.
Mn represents manganese. As long as the effects of the present invention are not impaired, Mn may be other activating elements such as europium (Eu), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), terbium (Tb), It may be partially substituted with one or more selected from the group consisting of dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm) and ytterbium (Yb).

The A element represents one or more elements selected from alkali metal elements, and examples thereof include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), and cesium (Cs). The element A is preferably K or Na, more preferably K, in that the effects of the present invention can be obtained satisfactorily.
The element D represents one or more elements selected from the group consisting of silicon (Si), germane (Ge), tin (Sn), titanium (Ti), and zirconium (Zr). The element D is preferably Si, Ge, or Ti, and more preferably Si, in that the effect of the present invention can be obtained satisfactorily.
F represents fluorine. F may be partially substituted with oxygen or other halogen elements such as chlorine (Cl), bromine (Br), iodine (I) and the like.

[Regarding Formula [1]]
It is preferable that the phosphor of the present invention further includes a crystal phase represented by the following formula [1].
Mn _m A _a D _b F _c [1]
(In the above formula [1],
A element represents one or more elements selected from the group consisting of alkali metal elements,
The D element represents one or more elements selected from the group consisting of Si, Ge, and Ti.

m, a, b, and c are values that satisfy the following formulas independently.
0 <m ≦ 0.2
1.6 ≦ a ≦ 2.4
m + b = 1
4.8 ≦ c ≦ 7.2)
Mn, A element, D element and F are the same as described above. Specific examples and preferred embodiments are also applicable.

m represents the content of Mn, the range is usually 0 <m ≦ 0.2, the lower limit is preferably 0.01, more preferably 0.02, and the upper limit is preferably 0. .15, more preferably 0.1.
Within the above range, concentration quenching is unlikely to occur, and a different phase showing a chemical composition other than the phosphor according to the present invention is unlikely to occur, which is preferable in terms of good light emission characteristics.

a represents the content of element A, and the range thereof is usually 1.6 ≦ a ≦ 2.4, and the lower limit is preferably 1.8, more preferably 1.85, and the upper limit is Preferably it is 2.2, More preferably, it is 2.15.
b represents the content of the D element.
The relationship between m and b is usually
m + b = 1
Satisfied.
c represents the content of fluorine, the range is usually 4.8 ≦ c ≦ 7.2, the lower limit is preferably 5.2, more preferably 5.6, and the upper limit is preferably Is 6.8, more preferably 6.4.

[TPD-MS analysis]
The phosphor of the present invention has an integral value of molecular weight 18 in the range of 200 ° C. or more and 600 ° C. or less as measured by TPD-MS analysis (hereinafter sometimes referred to as “integral value of molecular weight 18 in the present invention”). 50 μmol / g or less.
The integral value of the molecular weight 18 in the present invention is preferably 40 μmol / g or less, more preferably 30 μmol / g or less. Moreover, since the TPD-MS integral value in the present invention is preferably as the value is smaller, the lower limit value is usually larger than zero.
The reason why the gas having a molecular weight of 18 is analyzed among the emitted gases is to observe a specific amount of water contained in the phosphor.

(TPD-MS analysis method)
In the TPD-MS analysis measurement, an integrated value of molecular weight 18 is calculated from the analyzed released gas.
The amount of released gas is analyzed by temperature programmed desorption mass spectrometry and then mass spectrometry is performed. The mass spectrometer is not particularly limited as long as an integrated value of molecular weight 18 can be obtained. For example, AGS-7000 (manufactured by Anelva), M-400 (manufactured by Anelva), Q-1500 (JEOL) A gas chromatograph mass spectrometer such as that manufactured by Komatsu Ltd. is used.

The measurement is performed by using about 20 mg of a phosphor and increasing the temperature to 600 ° C. at a temperature increase rate of 20 to 40 ° C./min while circulating high-purity helium (that is, to make the oxygen concentration 5 ppm or less). taking measurement. Here, the gas having a molecular weight of 18 released in the temperature range of 200 ° C. to 600 ° C. is quantified.
In addition, about fixed_quantity | quantitative_assay, it compares with the integrated value of the molecular weight 18 obtained by the temperature-programmed desorption of calcium oxalate monohydrate.

  In the present invention, the reason for paying attention to the amount of water released in the temperature range of 200 ° C. to 600 ° C. is as follows. The moisture detected at less than 200 ° C. is the release of moisture adsorbed or adhered to the phosphor surface. Since these moisture easily desorbs from the phosphor, it hardly reacts with the phosphor to cause deterioration. Moreover, if it is less than 200 degreeC, it is low at the temperature which a fluorescent substance hydrolyzes below-mentioned. That is, it is difficult to cause deterioration of the phosphor in terms of temperature.

On the other hand, moisture detected at a temperature exceeding 600 ° C. is one in which stable and inert moisture present in the phosphor is released. For this reason, moisture detected at a temperature exceeding 600 ° C. hardly reacts with the phosphor to cause deterioration. It should be noted that even if the LED is continuously turned on, the temperature exceeding 600 ° C. is not actually reached. Therefore, in terms of temperature, it is difficult to cause deterioration of the phosphor.
Therefore, it is considered that the durability is improved by using a phosphor having a low water content in a temperature range that the LED can reach when it is turned on and thermally hydrolyzing the phosphor, and a temperature of 200 ° C. to 600 ° C. The amount of water released in the range is adopted.

(Reason for effect)
The reason why the durability is improved by using the phosphor of the present invention is estimated as follows. In addition, among the Mn activated fluoride phosphors, a KSF phosphor will be described as an example.
KSF is a substance that undergoes thermal hydrolysis, and in the presence of water and heat, decomposition occurs according to the following reaction formula.
K ₂ SiF ₆ + 2H ₂ O → ₂ KF + 4HF + SiO ₂
Similarly, when KSF phosphor (K ₂ (Si _1-n Mn _n ) F ₆ ) is thermally hydrolyzed, the decomposition proceeds according to the following reaction formula to produce black manganese dioxide (MnO ₂ ), resulting in a decrease in luminous efficiency. become.

_{K 2 (Si 1-n Mn} n) F 6 + 2H 2 O → 2KF + 4HF + (1-n) SiO 2 + nMnO 2
The LED generates heat as it is turned on. Therefore, when the KSF phosphor contains moisture, the thermal hydrolysis proceeds and the luminous efficiency of the KSF phosphor is lowered. When the luminous efficiency of the KSF phosphor that emits red light is reduced, the balance of the emission intensity of red, blue and green is lost, and the x value on the chromaticity coordinates is lowered.

That the water content of the KSF phosphor is small, that is, the integral value of the molecular weight 18 in the present invention is small, suppresses thermal hydrolysis of the KSF phosphor. As a result, the production of MnO ₂ is suppressed, so that the LED has high luminous efficiency and the luminescent color does not change with time.
Note that a decrease in light emission efficiency and a change in light emission color over time (color shift) affect the decomposition of the KSF phosphor and the generation of MnO ₂ . Therefore, the greater the amount of Mn contained in the KSF phosphor, the greater the degradation of the phosphor. As a result, the LED light emission efficiency decreases and the chromaticity shift also increases. Therefore, in the KSF phosphor having a large Mn content, the effect obtained becomes more remarkable when the integral value of the molecular weight 18 in the present invention is reduced.

[Characteristics of phosphor]
(Emission spectrum)
When the phosphor of the present invention is excited with light having a peak wavelength of 455 nm and the emission spectrum is measured, it preferably has the following characteristics.
The peak wavelength λp (nm) in the above emission spectrum is usually 600 nm or more, preferably 610 nm or more, more preferably 620 nm or more, and usually 650 nm or less.

Within the above range, it is preferable in that it has suitable orange to red light emission.
In the phosphor of the present invention, the half-value width of the emission peak in the above-mentioned emission spectrum is usually less than 50 nm, preferably 40 nm or less, more preferably 20 nm or less, particularly preferably 10 nm or less, and usually 1 nm or more. .
Within the above range, color purity and light emission intensity are excellent, which is preferable.
For example, a xenon light source can be used to excite the phosphor with light having a peak wavelength. The emission spectrum of the phosphor of the present invention can be measured using, for example, a fluorescence spectrophotometer F-4500 (manufactured by Hitachi, Ltd.). The emission peak wavelength and the half width of the emission peak can be calculated from the obtained emission spectrum.

{Phosphor production method}
The phosphor of the present invention is manufactured by dissolving each phosphor raw material in HF so as to contain Mn, A element, D element, and F, and mixing the obtained phosphor raw material solution in HF. Is possible.
Here, as a technical idea on the manufacturing method for making the phosphor of the present invention, for example, a method of synthesizing the phosphor with a reduced amount of water added in the reaction solution or a raw material with a low water content is used. Examples include a method of synthesizing a phosphor.

As the phosphor material, a metal compound, a metal, or the like is used. When producing the phosphor of the present invention, a source of Mn element (hereinafter referred to as “Mn source” as appropriate), a source of A element (hereinafter referred to as “A source” as appropriate), and a source of D element (hereinafter referred to as “D source” as appropriate) ), A necessary combination from the raw material of element F (hereinafter referred to as “F source” as appropriate) is dissolved in HF (dissolution step), and the obtained raw material solution is mixed and reacted in HF to produce a phosphor-containing slurry. (Precipitation step) The phosphor slurry obtained can be produced by washing (washing step) or dispersion / classification (dispersion / classification step) as necessary.
Although an example of the manufacturing method of the fluorescent substance of this invention is shown below, this invention is not limited to these.

[Phosphor material]
As the phosphor material used in the production of the phosphor in the present invention, known materials can be used.

(Mn source)
Examples of the Mn source include potassium permanganate (KMnO ₄ ), manganese dioxide (MnO ₂ ), manganese carbonate (MnCO ₃ ), potassium tetrafluoromanganate (K ₂ MnF ₆ ), manganese chloride (MnCl ₂ ) and the like. .

(A source)
In the A source, for example, specific examples of the K source include potassium hydrogen fluoride (KHF ₂ ), potassium fluoride (KF), potassium carbonate (K ₂ CO ₃ ), potassium hydrogen carbonate (KHCO ₃ ), potassium oxalate monohydrate. Examples thereof include Japanese (K ₂ C ₂ O ₄ .H ₂ O), potassium chloride (KCl), and the like. Of these, potassium hydrogen fluoride (KHF ₂ ) is preferable.
Specific examples of other alkali metal elements include compounds in which K is replaced with Li, Na, Rb or the like in the above-mentioned compounds listed as specific examples of the K source.

(D source)
In the D source, for example, specific examples of the Si source include hexafluorosilicate (H ₂ SiF ₆ ), potassium hexafluorosilicate (K ₂ SiF ₆ ), sodium hexafluorosilicate (Na ₂ SiF ₆ ), ammonium hexafluorosilicate ( NH ₄ ) ₂ SiF ₆ , rubidium hexafluorosilicate (Rb ₂ SiF ₆ ), cesium hexafluorosilicate (Cs ₂ SiF ₆ ), silicon oxide (SiO ₂ ), silicon (Si), and the like.
Specific examples of other elements include compounds in which Si is replaced with Ge, Sn, Ti, or the like in the above-described compounds listed as specific examples of the Si source.
As described above, the Mn source, the A source, and the D source may use different raw materials, respectively, or may use a raw material containing, for example, a Mn source and an A source in one raw material.

(F source)
Specific examples of the F source include hydrofluoric acid (HF), potassium hydrogen fluoride (KHF ₂ ), potassium fluoride (KF), hexafluorosilicic acid (H ₂ SiF ₆ ), potassium tetrafluoromanganate (K _2). MnF ₆ ), potassium hexafluorosilicate (K ₂ SiF ₆ ), fluorine (F ₂ ) and the like.

Furthermore, any of these carbonates, oxides, oxalates, metals, chlorides, and the like that can be converted into fluorides after being dissolved in HF can be used as a raw material.
The F source in the phosphor of the present invention may be supplied from a Mn source, A source, or D source, or may be supplied from HF as a reaction solution. Each raw material may contain inevitable impurities.

(Dissolution process)
In the production of the phosphor of the present invention, the phosphor raw materials are usually sufficiently dissolved in HF using a stirrer or the like in a necessary combination so as to obtain the target composition to obtain a phosphor raw material solution (dissolution step). .
As phosphor materials to be dissolved in combination, HF and A source, HF and D source, combination of HF and Mn, and three types of phosphor material solution, combination of HF and K source, HF, Si source and Mn source Even if two kinds of phosphor raw material solutions are used, or two kinds of phosphor raw material solutions are combined by combining HF, K source and Si source, and HF, K source and Mn source, the combination of raw materials is insoluble in HF. The raw materials may be dissolved in any combination as long as the combination does not produce the salt.

  The concentration of hydrofluoric acid (HF) used to dissolve the raw material may be within a range that can be converted to a fluoride after dissolving the raw material, but formation of compounds other than hydroxides and fluorides Is preferably about 40 to 55% by weight from the viewpoint of being easy to handle and easy to handle. In addition, it is preferable that a solvent having low phosphor solubility, such as ethanol or acetone, is mixed with hydrofluoric acid and mixed with the raw material solution in advance in order to easily obtain the phosphor of the present invention.

(Precipitation process)
The production of the phosphor of the present invention includes a step (precipitation step) of producing a phosphor-containing slurry by mixing and reacting the obtained phosphor raw material solution in HF.
The method of producing a phosphor-containing slurry by mixing and reacting phosphor raw material solutions is, for example, a phosphor raw material solution comprising HF and K sources, a phosphor raw material solution comprising HF and Si sources, and an HF and Mn source. A phosphor raw material solution consisting of HF, a K source and a Mn source in a phosphor raw material solution consisting of an HF, a K source and a Si source. The reaction may be carried out by any method as long as the phosphor-containing slurry is produced by reacting after mixing, such as a method of producing a phosphor-containing slurry to which the phosphor raw material solution is added and reacting, or the reverse method.

Hydrofluoric acid used when mixing phosphor raw material solution to produce phosphor-containing slurry (
The concentration of HF) may be in the range where the phosphor raw material solution can react and the precipitate can become a fluoride, but the formation of compounds other than hydroxides and fluorides can be suppressed, and handling is easy. In this respect, about 40 to 55% by weight is preferable.
A solution containing ethanol, water, acetone or the like, which may be mixed when a raw material reaction solution is mixed with a solvent having low solubility of KSF such as ethanol or acetone to produce a phosphor-containing slurry, may be used as it is. You may use it, mixing with hydrogen acid. Moreover, you may mix beforehand with the said fluorescent substance raw material solution.
There is no restriction | limiting in particular in the speed | rate which adds a phosphor raw material solution, For example, 1L / min or 1L / hour may be sufficient. This is because the production speed of the phosphor of the present invention is high. Also, the reaction temperature is not particularly limited, but a lower liquid temperature is preferable because the solubility of the KSF phosphor is low and the yield is increased.

(Washing process)
After producing the phosphor slurry, it is preferable to have a step (washing step) of washing the phosphor produced by precipitation before separating the phosphor by filtration.
When the phosphor of the present invention is synthesized, the raw material residue and impurities generated during dissolution tend to remain in the phosphor. In order to improve the properties of the obtained phosphor, it is preferable to remove these impurities as much as possible. In the present invention, the cleaning method is not particularly limited as long as impurities can be removed. For example, if the phosphor produced is a compound other than fluoride such as hydroxide, such as hydrofluoric acid, a mixture of potassium hydrogen fluoride and hydrofluoric acid, or a mixture of hexafluorosilicic acid and hydrofluoric acid. If not, it can be washed with any liquid.

In particular, it is preferable to wash with hydrofluoric acid because it is easy to remove the residue and impurities of the raw material. The concentration of hydrofluoric acid used for washing is preferably about 40 to 55% by weight from the viewpoint that generation of compounds other than hydroxides and fluorides can be suppressed and handling is easy.
The weight of hydrofluoric acid used for washing the phosphor is usually 1 or more times, preferably 3 or more, more preferably 5 or more, and usually 100 or less, preferably 50 times the weight of the phosphor. It is as follows.

While the phosphor is immersed in the cleaning solution, it may be left still, but it should be stirred to such an extent that the cleaning time can be shortened in terms of work efficiency and preventing the phosphor from degrading in quality. Is preferred. The washing temperature is usually room temperature, but the aqueous solution may be heated as necessary. Further, an oxidizing agent or a reducing agent such as hydrogen peroxide solution (H ₂ O ₂ ) may be added to the cleaning liquid.
The time for immersing the phosphor in hydrofluoric acid varies depending on the stirring conditions and the like, but is usually 10 minutes or longer, preferably 1 hour or longer, and usually 24 hours or shorter, preferably 12 hours or shorter. Further, the cleaning may be performed a plurality of times, and the type and concentration of the cleaning liquid may be changed.
In the washing step, it is preferable to perform filtration while substituting the precipitation reaction solution with ethanol, acetone, methanol, or the like after performing the operation of immersing the phosphor in the washing solution.

(Dispersion / classification process)
The obtained phosphor is granular or massive. When this is dispersed using a general disperser such as a ball mill, a vibration mill, or a jet mill, the light emission characteristics of the phosphor tend to deteriorate. This is because the phosphor of the present invention is pulverized by the above-described general dispersion method having a weak dispersion force and a strong dispersion force.
Therefore, it is preferable to disperse and classify the obtained phosphor with a sieve having different openings without passing through a dispersion process, and to pass the powder that has passed through the sieve or the powder remaining on the sieve to the next process.

{Phosphor-containing composition}
The phosphor of the present invention can be used by mixing with a liquid medium. In particular, when the phosphor of the present invention is used for applications such as a light emitting device, it is preferably used in a form dispersed in a liquid medium. A material in which the phosphor of the present invention is dispersed in a liquid medium is appropriately referred to as a “phosphor-containing composition in the present invention” or the like.

[Phosphor]
There is no restriction | limiting in the kind of fluorescent substance of this invention contained in the fluorescent substance containing composition in this invention, It can select arbitrarily from above-mentioned. Moreover, the fluorescent substance of this invention contained in the fluorescent substance containing composition in this invention may be only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Furthermore, the phosphor-containing composition of the present invention may contain a phosphor other than the phosphor of the present invention as long as the effects of the present invention are not significantly impaired.

[Liquid medium]
The liquid medium used in the phosphor-containing composition in the present invention is not particularly limited as long as the performance of the phosphor is not impaired within the intended range. For example, any inorganic material and / or organic material may be used as long as it exhibits liquid properties under the desired use conditions, suitably disperses the phosphor of the present invention, and does not cause an undesirable reaction. Examples thereof include silicone resin, epoxy resin, and polyimide silicone resin.

[Content of liquid medium and phosphor]
The content of the phosphor and the liquid medium in the phosphor-containing composition in the present invention is arbitrary as long as the effects of the present invention are not significantly impaired, but usually 20% by weight or more with respect to the entire phosphor-containing composition, Preferably it is 40 weight% or more, and is 99 weight% or less normally, Preferably it is 95 weight% or less.

[Other ingredients]
In addition, you may make the fluorescent substance containing composition in this invention contain other components other than a fluorescent substance and a liquid medium, unless the effect of this invention is impaired remarkably. Moreover, only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and a ratio.

{Light emitting device}
The phosphor of the present invention is a light-emitting device including a first light emitter (excitation light source) and a second light emitter that emits visible light when irradiated with light from the first light emitter. The luminous body 2 contains the phosphor of the present invention. Here, any one of the phosphors of the present invention may be used alone, or two or more thereof may be used in any combination and ratio.

As the phosphor included in the light emitting device of the present invention, for example, a phosphor that emits fluorescence in an orange or red region under irradiation of light from an excitation light source is used. Specifically, when a light-emitting device is configured, the orange to red phosphor has a wavelength range of 600 nm to 650 nm.
As the excitation source, one having an emission peak in a wavelength range of less than 455 nm may be used.

Hereinafter, the mode of the light emitting device in the case where the phosphor of the present invention has a light emission peak in the wavelength range of 600 nm or more and 650 nm or less and the first light emitter has a light emission peak in the wavelength range of 455 nm is used. Although described, the present invention is not limited to these.
In the above case, the light emitting device of the present invention can be set, for example, in the following aspect (A) or (B).
(A) As the first phosphor, one having an emission peak at 455 nm is used, and as the first phosphor of the second phosphor, at least one kind of fluorescence having an emission peak in a wavelength range of 560 nm to less than 600 nm A mode in which the phosphor of the present invention is used as the second phosphor of the body (yellow phosphor) and the second light emitter.
(B) As the first illuminant, one having an emission peak at 455 nm is used, and as the first phosphor of the second illuminant, at least one kind of fluorescence having an emission peak in a wavelength range of 500 nm to less than 560 nm. A mode in which the phosphor of the present invention is used as the second phosphor of the body (green phosphor) and the second light emitter.

(Yellow phosphor)
For example, the following phosphors are preferably used as the yellow phosphor.
Examples of the garnet phosphor include (Y, Gd, Lu, Tb, La) ₃ (Al, Ga) ₅ O ₁₂ : (Ce, Eu, Nd),
Examples of the orthosilicate include (Ba, Sr, Ca, Mg) ₂ SiO ₄ : (Eu, Ce),
Examples of (acid) nitride phosphors include (Ba, Ca, Mg) Si ₂ O ₂ N ₂ : Eu (SION phosphor), (Li, Ca) ₂ (Si, Al) ₁₂ (O, N ₁₆ : (Ce, Eu) (α-sialon phosphor), (Ca, Sr) AlSi ₄ (O, N) ₇ : (Ce, Eu) (1147 phosphor), (La, Ca, Y) ₃ ( Al, Si) ₆ N ₁₁ : Ce (LSN phosphor)
Etc.
The phosphor is preferably a garnet phosphor, and most preferably a YAG phosphor represented by Y ₃ Al ₅ O ₁₂ : Ce.

(Green phosphor)
For example, the following phosphors are preferably used as the green phosphor.
Examples of the garnet phosphor include (Y, Gd, Lu, Tb, La) ₃ (Al, Ga) ₅ O ₁₂ : (Ce, Eu, Nd), Ca ₃ (Sc, Mg) ₂ Si ₃ O _12. : (Ce, Eu) (CSMS phosphor),
Examples of the silicate phosphor include (Ba, Sr, Ca, Mg) ₃ SiO ₁₀ : (Eu, Ce), (Ba, Sr, Ca, Mg) ₂ SiO ₄ : (Ce, Eu) (BSS phosphor). ),
As the oxide phosphor, for example, (Ca, Sr, Ba, Mg) (Sc, Zn) ₂ O ₄ : (Ce, Eu) (CASO phosphor),
Examples of (acid) nitride phosphors include (Ba, Sr, Ca, Mg) Si ₂ O ₂ N ₂ : (Eu, Ce), Si _6-z Al _z O _z N _8−z : (Eu, Ce) (β-sialon phosphor) (0 <z ≦ 1), (Ba, Sr, Ca, Mg, La) ₃ (Si, Al) ₆ O ₁₂ N ₂ : (Eu, Ce) (BSON phosphor) ,
As the aluminate phosphor, for example, (Ba, Sr, Ca, Mg) ₂ Al ₁₀ O ₁₇ : (Eu, Mn) (GBAM phosphor)
Etc.

(Red phosphor)
In the light emitting device of the present invention, other red phosphors may be used in combination with the phosphor of the present invention. As other red phosphors, for example, the following phosphors are preferably used.
Examples of sulfide phosphors include (Sr, Ca) S: Eu (CAS phosphor), La ₂ O ₂ S: Eu (LOS phosphor),
Examples of the garnet phosphor include (Y, Lu, Gd, Tb) ₃ Mg ₂ AlSi ₂ O ₁₂ : Ce,
Examples of nanoparticles include CdSe,
Examples of the nitride or oxynitride phosphor include (Sr, Ca) AlSiN ₃ : Eu (S / CASN phosphor), (CaAlSiN ₃ ) _1-x · (SiO ₂ N ₂ ) _x : Eu (CASON fluorescence). Body), (La, Ca) ₃ (Al, Si) ₆ N ₁₁ : Eu (LSN phosphor), (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu (258 phosphor), ( Sr, Ca) Al
_{1 + x} Si _4-x O _x N _7-x : Eu (1147 phosphor), M _x (Si, Al) ₁₂ (O, N) ₁₆ : Eu (M is Ca, Sr, etc.) (α sialon phosphor) , Li (Sr, Ba) Al ₃ N ₄ : Eu (wherein x is 0 <x <1).

[Configuration of light emitting device]
The light-emitting device of the present invention has a first light emitter (excitation light source), and at least the phosphor of the present invention is used as the second light emitter. It is possible to arbitrarily adopt the apparatus configuration.
Examples of the device configuration and the light emitting device include those described in Japanese Patent Application Laid-Open No. 2007-291352.

In addition, examples of the form of the light emitting device include a shell type, a cup type, a chip on board, a remote phosphor, and the like.
The application of the light-emitting device of the present invention is not particularly limited and can be used in various fields where ordinary light-emitting devices are used. However, since the color reproduction range is wide and the color rendering property is high, illumination is particularly important. It is particularly preferably used as a light source for a device or an image display device.

{Lighting device}
The illumination device of the present invention includes the light emitting device of the present invention as a light source.
When the light-emitting device of the present invention is applied to a lighting device, the above-described light-emitting device may be appropriately incorporated into a known lighting device. For example, a surface emitting illumination device in which a large number of light emitting devices are arranged on the bottom surface of the holding case can be used.

{Image display device}
The image display apparatus of the present invention includes the light-emitting device of the present invention as a light source.
When the light emitting device of the present invention is used as a light source of an image display device, the specific configuration of the image display device is not limited, but is preferably used with a color filter. For example, when the image display device is a color image display device using a color liquid crystal display element, the light emitting device is a backlight, a light shutter using liquid crystal and a color filter having red, green, and blue pixels; By combining these, an image display device can be formed.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples without departing from the gist thereof.
{Measuring method}
[Measurement of luminous characteristics]
For measurement of the emission spectrum of the phosphor, a fluorescence measuring apparatus (manufactured by JASCO Corporation) equipped with a 150 W xenon lamp as an excitation light source and a multi-channel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measuring apparatus was used. The emission peak wavelength and the half width of the emission peak were calculated from the obtained emission spectrum.

[TPD-MS analysis]
The amount of released gas was analyzed by temperature programmed desorption mass spectrometry followed by mass spectrometry. Q-1500 (manufactured by JEOL Ltd.) was used as a mass spectrometer.
The measurement is performed by using about 20 mg of phosphor and circulating high-purity helium while raising the temperature to 600 ° C. at a temperature increase rate of 20 to 40 ° C./min, and releasing in a temperature range of 200 ° C. to 600 ° C. The amount of gas having a molecular weight of 18 was quantified. The quantitative value is a value compared with an integrated value of molecular weight 18 obtained by temperature programmed desorption of calcium oxalate monohydrate.

{Manufacture of phosphor}
Example 1
The phosphor was synthesized by the following method.
To solution A obtained by dissolving and mixing 21.7 g of K ₂ MnF ₆ and H ₂ SiF ₆ weighed so that the molar ratio of Si: Mn is 0.9: 0.1 in 1100 ml of 47 wt% HF, KHF ₂ weighed so that the molar ratio of Si + Mn: K was 1: 2 was dissolved in 225 ml of 47% by weight HF, and 25 ml of ethanol was further added to mix the solution B, and K ₂ SiF ₆ : Mn ⁴⁺ was mixed. A phosphor-containing slurry containing was obtained.

Next, the phosphor-containing slurry containing K ₂ SiF ₆ : Mn ⁴⁺ is allowed to stand to precipitate the phosphor, and then the supernatant liquid in which unreacted Mn, K, or Si remains is discarded, and the phosphor weight is 10 Double 47 wt% HF solution was added and stirred for 30 minutes, then allowed to stand, the phosphor was allowed to settle, the supernatant was discarded, washed, filtered, washed with ethanol, and dried at 100 ° C for 15 hours. 1 phosphor was obtained.
The emission peak wavelength of the phosphor of Example 1 was 631 nm, and the half width of the main emission peak was 6 nm.

(Example 2)
The solution A obtained by dissolving and mixing H ₂ SiF ₆ in 2100 g of K ₂ MnF ₆ and Si: Mn in a molar ratio of 0.9: 0.1 in 1100 ml of 55 wt% HF was added to Si + Mn. : A phosphor-containing slurry containing K ₂ SiF ₆ : Mn ⁴⁺ by mixing solution B obtained by dissolving KHF ₂ weighed so that the molar ratio of K is 1: 2 in 250 ml of 55 wt% HF Got.

Subsequently, it was washed in the same manner as in Example 1, filtered, washed with ethanol, and then dried at 100 ° C. for 15 hours to obtain the phosphor of Example 2.
Further, the emission peak wavelength of the phosphor of Example 2 was 631 nm, and the half width of the main emission peak was 6 nm.

(Comparative Example 1)
A phosphor was manufactured in the same manner as in Example 1 except that ethanol added to the solution B to be mixed in Example 1 was changed to pure water, and a phosphor of Comparative Example 1 was obtained.

{Light emitting device}
Light emitting devices using the phosphors of Examples 1 and 2 and the phosphor of Comparative Example 1 were prepared as follows, and LED durability (Δx) was measured.

(Creation of light emitting device)
A mixture obtained by mixing the phosphor of Example 1 and β-SIALON phosphor BG-601 / E (manufactured by Mitsubishi Chemical Corporation) as a green phosphor at a predetermined mixing ratio, and 5 of Aerosil (RX200) as a thickener. A phosphor-containing composition was added and dispersed in a silicone resin KER-2500 (manufactured by Shin-Etsu Chemical Co., Ltd.). Next, one 810 μm square InGaN-based blue LED chip was mounted on a 5050 SMD type ceramic package and sealed with the phosphor-containing composition to obtain a white LED containing the phosphor of Example 1.

The emission peak wavelength of the blue LED chip in the produced white LED was 452.5 to 455 nm, and a current of 350 mA was applied to the produced white LED to emit light.
The white LED has a mixing ratio of the phosphor of Example 1 and the β-SiALON phosphor, and phosphor so that the emission chromaticity (x, y) is x = 0.276 and y = 0.263. The amount of sealing with a silicone resin in which was dispersed was prepared.
In the same manner as described above, a light emitting device including the phosphor of Example 2 and the phosphor of Comparative Example 1 was produced.

(Measurement of luminous flux and LED durability test)
The following durability test was done about the light-emitting device obtained above.
A current of 350 mA was passed through the light emitting device, and the LED light flux and the emission spectrum were measured at 0 hours of current flow with a spectroscopic measuring device equipped with an integrating sphere.

Next, the light-emitting device was continuously energized with a driving current of 150 mA in a constant-temperature bath set at 85 ° C., and the light-emitting device was taken out of the thermostat at 20 hours from the start of energization, and the emission spectrum was measured in the same manner as at time 0. .
The durability of the phosphors of Examples 1 and 2 and the phosphor of Comparative Example 1 is the difference (Δx) between the chromaticity coordinates x calculated from the emission spectrum obtained after 20 hours and the chromaticity coordinates x at time 0. Sex was evaluated.
The results are shown in Table 1.

  As shown in Table 1, the light emitting device including the phosphor of the present invention has a small Δx value. That is, in the light emitting device including the phosphor of the present invention, the luminescent color does not change with time. Therefore, the illumination device and the image display device including the light emitting device of the present invention are of high quality.

Claims (8)

A phosphor containing a crystal phase having Mn, A element, D element, and F,
A phosphor having an integral value of a molecular weight of 18 in a range of 200 ° C. or more and 600 ° C. or less measured by TPD-MS analysis is 50 μmol / g or less.
(However, the A element represents one or more elements selected from the group consisting of alkali metal elements,
The D element represents one or more elements selected from the group consisting of Si, Ge, Sn, Ti, and Zr. ) The phosphor according to claim 1, wherein the crystal phase is a crystal phase represented by the following formula [1].
Mn _m A _a D _b F _c [1]
(In the above formula [1],
A element represents one or more elements selected from the group consisting of alkali metal elements,
The D element represents one or more elements selected from the group consisting of Si, Ge, and Ti.
m, a, b, and c are values that satisfy the following formulas independently.
0 <m ≦ 0.2
1.6 ≦ a ≦ 2.4
m + b = 1
4.8 ≦ c ≦ 7.2)   The phosphor according to claim 1 or 2, wherein the element A contains one or more elements selected from the group consisting of Li, Na, K, Rb, and Cs.   The fluorescence according to any one of claims 1 to 3, which has an emission peak wavelength in a range of 600 nm to 650 nm by irradiating excitation light having a wavelength of 350 nm to 460 nm. body.   The phosphor according to any one of claims 1 to 4, wherein a half-value width of an emission spectrum obtained by irradiating excitation light having a wavelength of 350 nm or more and 460 nm or less is 50 nm or less. .   A first light emitter and a second light emitter that emits visible light by irradiation of light from the first light emitter, the second light emitter according to any one of claims 1 to 5. A light emitting device comprising the phosphor described above.   An illumination device comprising the light-emitting device according to claim 6 as a light source.   An image display device comprising the light-emitting device according to claim 6 as a light source.