JP2012201707A - Coated phosphor and light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coated phosphor which is improved in moisture resistance.SOLUTION: The coated phosphor 100 includes: a phosphor particle 101; a first layer 102 covering the outside of the phosphor particle 101; and a second layer 103 covering the outside of the first layer 102. The first layer 102 is formed from a metal oxide. The second layer 103 has a hydrophobic substituent.

Description

  The present invention relates to a coated phosphor and a light emitting device including the coated phosphor.

  A light-emitting device including a semiconductor light-emitting element such as a light-emitting diode (LED) and a phosphor that converts the wavelength of light emitted from the semiconductor light-emitting element is small in size, consumes less power than an incandescent bulb, and is white. It is possible to emit light of an appropriate color according to the purpose of use. For this reason, such a light-emitting device includes a liquid crystal display, a backlight light source in a liquid crystal display device such as a mobile phone or a portable information terminal, a display device used for indoor / outdoor advertisements, indicators of various portable devices, and an illumination switch. It can be used as a light source for OA (office automation) equipment. In recent years, development has been performed for the purpose of improving the light emission efficiency of such a light emitting device and improving the reliability.

  One of the light-emitting devices developed so far is a light-emitting device including a semiconductor light-emitting element that emits blue or blue-violet light or ultraviolet light, and a phosphor. Various oxides and sulfides are used as phosphors in the light emitting device. In particular, a phosphor made of silicate or sulfide has a very high luminous efficiency.

  However, the phosphor may deteriorate over time due to hydration reaction with moisture in the air and hydrolysis. For this reason, there exists a problem that the lifetime of a light-emitting device provided with fluorescent substance will become short.

  Therefore, conventionally, in order to improve the moisture resistance of the phosphor, a surface treatment is performed on the phosphor to form a layer that blocks moisture on the surface of the phosphor, thereby allowing moisture to penetrate into the phosphor from the outside. It has been proposed to suppress this.

  For example, Patent Document 1 discloses that the rate of increase in moisture absorption is continuous and has a film thickness of 1 nm to 10000 nm by hydrolyzing and dehydrating a metal alkoxide at an ambient temperature of 1 to 20 ° C. on the surface of the phosphor. It is disclosed to form a metal oxide film of 5 wt% or less.

  However, in the method described in Patent Document 1, the time required for the water that has penetrated the metal oxide film to reach the phosphor is increased, and a fundamental solution for improving the moisture resistance of the phosphor is It is not.

JP 2008-1111080 A

  The present invention has been made in view of the above reasons, and an object of the present invention is to provide a coated phosphor having improved moisture resistance and a light emitting device including the coated phosphor.

  The coated phosphor according to the present invention includes phosphor particles, a first layer covering the outside of the phosphor particles, and a second layer covering the outside of the first layer, and the first layer is a metal. Formed from an oxide, the second layer comprises a hydrophobic substituent.

  In the coated phosphor according to the present invention, the first layer is formed from a condensate of at least one compound selected from a metal alkoxide represented by the following chemical formula (1) and a partial hydrolysis condensate thereof. It is preferable.

M ¹ (OR ¹ ) _m (1)
M ¹ is a metal element.
R ¹ is selected from an alkyl group and hydrogen, and when a plurality of R ¹ are present in one molecule, they may be the same as or different from each other.
m number is equal to the valence of the metal element M ^1.

  In the coated phosphor according to the present invention, the second layer is formed from a condensate of at least one compound selected from a metal alkoxide and a partial hydrolysis condensate thereof, and the metal alkoxide has the following chemical formula (2 It is preferable that the metal alkoxide shown by this is contained.

M ² (R ² ) _nx (R ² ′) _x (2)
M ² is a metal element selected from Si, Ti, Al, Zr, Ge, and Y.
R ² is a functional group selected from an alkoxide group, a hydroxyl group, and a chloro group, and when a plurality of R ² are present in one molecule, they may be the same as or different from each other.
R ² ′ is a substituent selected from — (CH ₂ ) _y —CH ₃ and — (CH ₂ ) ₂ — (CF ₂ ) _z —CF ₃ , and when there are a plurality of R ² ′ in one molecule They may be the same or different.
n number is equal to the valence of the metal element M ^2.
x is an integer of 1 or more and satisfies the relationship of n> x.
y is an integer of 2 or more.
z is an integer of 1 or more.

  In the coated phosphor according to the present invention, the second layer may be formed of an alkyl group introduced onto the surface of the first layer by a silazane compound represented by the following chemical formula (3): preferable.

_{^{(R 3) 3 -Si-NH}} -Si (R 3) 3 ... (3)
R ³ is an alkyl group, and a plurality of R ³ present in one molecule may be the same as or different from each other.

  In the coated phosphor according to the present invention, it is preferable that the phosphor particles are formed of an alkaline earth silicate phosphor.

In the coated phosphor according to the present invention, the first layer includes a plurality of layers including at least a third layer disposed on the innermost side and a fourth layer laminated on the third layer. And
The third layer is formed from a condensate of at least one compound selected from a metal alkoxide represented by the following chemical formula (1-1) and a partial hydrolysis condensate thereof,
The fourth layer is preferably formed from a condensate of at least one compound selected from a metal alkoxide represented by the following chemical formula (1-2) and a partial hydrolysis condensate thereof.

Al (OR ¹ ) ₃ (1-1)
R ¹ is selected from an alkyl group and hydrogen, and when a plurality of R ¹ are present in one molecule, they may be the same as or different from each other.

M ¹ (OR ¹ ) _m (1-2)
M ¹ is a metal element selected from Si, Ti, Zr, Ge, and Y.
R ¹ is selected from an alkyl group and hydrogen, and when a plurality of R ¹ are present in one molecule, they may be the same as or different from each other.
m number is equal to the valence of the metal element M ^1.

  In the coated phosphor according to the present invention, the total thickness of the first layer and the second layer is preferably in the range of 10 to 1000 nm.

  The light emitting device according to the present invention includes the coated phosphor.

  According to the present invention, a coated phosphor with significantly improved moisture resistance and a light emitting device including the coated phosphor can be obtained.

(A) And (b) is the schematic which shows the cross-section of the coated fluorescent substance in one Embodiment of this invention, and a wavelength conversion member provided with this coated fluorescent substance. It is a partially broken disassembled perspective view which shows the light-emitting device in one Embodiment of this invention. It is sectional drawing of the said light-emitting device.

  The coated phosphor 100 according to this embodiment includes phosphor particles 101, a first layer 102 that covers the outside of the phosphor particles 101, and a second layer 103 that covers the outside of the first layer 102.

  FIG. 1A and FIG. 1B show a cross-sectional structure of a coated phosphor 100 according to this embodiment. In FIG. 1A, the first layer 102 is composed of a single layer, and in FIG. 1B, the first layer 102 is composed of a plurality of layers.

There is no particular limitation on the phosphors of the phosphor particles 101, for example, _{^{CaAlSiN 3: Eu 2+, (Ca}} , Sr) AlSiN 3: Eu 2+, CaS: Eu 2+, (Ca, Sr) 2 Si 5 N 8 : Red phosphor having a composition such as Eu ²⁺ ; CaSc ₂ O ₄ : Ce ³⁺ , Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce ³⁺ , (Ca, Sr, Ba) Al ₂ O ₄ : Eu ²⁺ , SrGa ₂ S ₄ : a green phosphor having a composition such as Eu ²⁺ ; a yellow phosphor having a composition such as Y ₃ Al ₅ O ₁₂ : Ce ³⁺ , (Ca, Sr, Ba, Zn) ₂ SiO ₄ : Eu ²⁺ ; _Sr) 2 _SiO 4: yellow-green phosphor having a composition of ^{Eu 2+} and the _{^{like; Sr 3 SiO 5: Eu 2+}} , Ca 0.7 Sr 0.3 AlSiN 3: orange having a composition of ^{Eu 2+} and the like Such as phosphor, and the like.

In particular, the phosphor particles 101 are Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce ³⁺ , (Ca, Sr, Ba, Zn) ₂ SiO ₄ : Eu ²⁺ , (Ba, Sr) ₂ SiO ₄ : Eu ²⁺ , Sr ₃ SiO. ₅ : Preferably formed from an alkaline earth silicate phosphor such as Eu ²⁺ . In this case, the luminous efficiency of the coated phosphor 100 is increased by using an alkaline earth silicate phosphor having a high luminous efficiency. Moreover, although the alkaline earth silicate phosphor is inherently low in moisture resistance, the first layer 102 and the second layer 103 greatly improve the moisture resistance. For this reason, there is no particular limitation on the particle size of the phosphor particles 101 from which the coated phosphor 100 particles having high luminous efficiency and very high moisture resistance can be obtained. However, the larger the particle size of the phosphor particles 101, the lower the defect density in the phosphor particles 101. Therefore, the energy loss during light emission is reduced and the light emission efficiency is increased. In particular, from the viewpoint of luminous efficiency, the average particle diameter of the phosphor particles 101 is preferably 5 μm or more. This average particle diameter is a value measured by a laser diffraction / scattering particle size distribution measuring apparatus.

  The first layer 102 is formed from a metal oxide. The first layer 102 may be formed from a condensate (metal oxide) of at least one compound selected from a metal alkoxide represented by the following chemical formula (1) and a partial hydrolysis condensate thereof. preferable. In the metal alkoxide represented by the chemical formula (1), only the alkoxide group is bonded to the metal atom, and there is no long-chain alkyl group or fluorine-containing group directly bonded to the metal atom. In a metal oxide generated from such a metal alkoxide or the like, the crosslink density between metal atoms is increased. This makes the first layer 102 very dense.

M ¹ (OR ¹ ) _m (1)
In the chemical formula (1), M ¹ is a metal atom selected from Si, Ti, Al, Zr, Ge, and Y. m is a number equal to the valence of the metal atom M ^1.

R ¹ is selected from an alkyl group and hydrogen. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. When a plurality of R ¹ are present in one molecule, the plurality of R ¹ may be the same as or different from each other. For example, R ¹ may be all alkyl groups such as a methyl group, an ethyl group, a propyl group, and a butyl group, R ¹ may be all hydrogen, or some of the plurality of R ¹ are alkyl groups. And the remainder may be all hydrogen.

Specific examples of the metal alkoxide represented by the chemical formula (1) include
Substituted or unsubstituted alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetrakis (2-methoxyethoxy) silane;
Aluminum triethoxide, aluminum tri-n-propoxide, aluminum triisopropoxide, aluminum tri-n-butoxide, aluminum triisobutoxide, aluminum tri-sec-butoxide, aluminum tri-tert-butoxide, aluminum tris (hexyl oxide) ), Aluminum tris (2-ethylhexyl oxide), aluminum tris (2-methoxyethoxide), aluminum tris (2-ethoxyethoxide), aluminum tris (2-butoxyethoxide), etc., substituted or unsubstituted aluminum alkoxides Kind;
Titanium alkoxides such as titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetraisopropoxide, titanium tetra-n-butoxide, titanium tetra-sec-butoxide, titanium tetrakis (2-ethylhexyl oxide);
Zirconium alkoxides such as zirconium tetraethoxide, zirconium tetra-n-propoxide, zirconium tetraisopropoxide, zirconium tetra-n-butoxide, zirconium tetra-sec-butoxide, zirconium tetrakis (2-ethylhexyl oxide);
Germanium alkoxides such as germanium tetraethoxide, germanium tetra-n-propoxide, germanium tetraisopropoxide, germanium tetra-n-butoxide, germanium tetra-sec-butoxide, germanium tetrakis (2-ethylhexyl oxide);
Yttrium hexaethoxide, yttrium hexaethoxide-n-propoxide, yttrium hexaethoxide isopropoxide, yttrium hexaethoxide-n-butoxide, yttrium hexaethoxide-sec-butoxide, yttrium hexaethoxide (2-ethylhexyl) Yttrium alkoxides, such as oxide);
Is mentioned.

  At least one compound selected from the metal alkoxide represented by the chemical formula (1) and the partial hydrolysis condensate thereof may be only the metal alkoxide as described above, or only the partial hydrolysis condensate of the metal alkoxide. Alternatively, it may be a mixture of a metal alkoxide and a partial hydrolysis condensate of metal alkoxide.

  The first layer 102 is preferably composed of a plurality of layers having different compositions as shown in FIG. That is, it is preferable that any of the plurality of layers constituting the first layer 102 is formed from a condensate containing a metal species different from the other layers.

  Further, in the case where the first layer 102 includes a plurality of layers, the innermost layer (third layer 104) in the first layer 102 among the plurality of layers has the following chemical formula ( It is preferably formed from a condensate (with aluminum oxide) of at least one compound selected from the metal alkoxide (aluminum alkoxide) shown in 1-1) and a partial hydrolysis condensate thereof.

Al (OR ¹ ) ₃ (1-1)
In the chemical formula (1-1), R ¹ is selected from an alkyl group and hydrogen, and when a plurality of R ¹ are present in one molecule, they may be the same as or different from each other.

  Specific examples of the metal alkoxide represented by the chemical formula (1-1) include aluminum triethoxide, aluminum tri-n-propoxide, aluminum triisopropoxide, aluminum tri-n-butoxide, aluminum triisobutoxide, aluminum triethoxide. -Sec-butoxide, aluminum tri-tert-butoxide, aluminum tris (hexyl oxide), aluminum tris (2-ethylhexyl oxide), aluminum tris (2-methoxyethoxide), aluminum tris (2-ethoxyethoxide), aluminum tris Substituted or unsubstituted aluminum alkoxides, such as (2-butoxyethoxide).

  Even if the at least one compound selected from the metal alkoxide represented by the chemical formula (1-1) and the partial hydrolysis condensate thereof is only the metal alkoxide as described above, the partial hydrolysis condensate of the metal alkoxide. Or a mixture of a metal alkoxide and a partially hydrolyzed condensate of metal alkoxide.

  Further, among the plurality of layers constituting the first layer 102, the layer (fourth layer 105) laminated just outside the third layer 104 is a metal represented by the following chemical formula (1-2). It is preferably formed from a condensate of at least one compound selected from an alkoxide and a partial hydrolysis condensate thereof.

M ¹ (OR ¹ ) _m (1-2)
In the chemical formula (1-2), M ¹ is a metal atom selected from Si, Ti, Zr, Ge, and Y. R ¹ is selected from an alkyl group and hydrogen, and when a plurality of R ¹ are present in one molecule, they may be the same as or different from each other. m is a number equal to the valence of the metal atom M ^1.

As specific examples of the metal alkoxide represented by the chemical formula (1-2),
Substituted or unsubstituted alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane, tetra-n-butoxysilane, tetrakis (2-methoxyethoxy) silane;
Titanium alkoxides such as titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetraisopropoxide, titanium tetra-n-butoxide, titanium tetra-sec-butoxide, titanium tetrakis (2-ethylhexyl oxide);
Zirconium alkoxides such as zirconium tetraethoxide, zirconium tetra-n-propoxide, zirconium tetraisopropoxide, zirconium tetra-n-butoxide, zirconium tetra-sec-butoxide, zirconium tetrakis (2-ethylhexyl oxide);
Germanium alkoxides such as germanium tetraethoxide, germanium tetra-n-propoxide, germanium tetraisopropoxide, germanium tetra-n-butoxide, germanium tetra-sec-butoxide, germanium tetrakis (2-ethylhexyl oxide);
Yttrium hexaethoxide, yttrium hexaethoxide-n-propoxide, yttrium hexaethoxide isopropoxide, yttrium hexaethoxide-n-butoxide, yttrium hexaethoxide-sec-butoxide, yttrium hexaethoxide (2-ethylhexyl) Yttrium alkoxides, such as oxide);
Is mentioned.

  Even if the at least one compound selected from the metal alkoxide represented by the chemical formula (1-2) and its partial hydrolysis condensate is only the metal alkoxide as described above, the partial hydrolysis condensate of the metal alkoxide Or a mixture of a metal alkoxide and a partially hydrolyzed condensate of metal alkoxide.

  When the first layer 102 includes the third layer 104 and the fourth layer 105 as described above, the adhesion between the first layer 102 and the phosphor particles 101 is enhanced. This is considered to be because electrostatic attraction acts between the phosphor particles 101 and the third layer 104 and between the third layer 104 and the fourth layer 105. This is because, in a system in which the phosphor particles 101 are dispersed in water, the zeta potential of the phosphor particles 101 having no coating is a negative value, and the zeta of the phosphor particles 101 coated with the third layer 104 is This is inferred from the fact that the potential is a positive value, and the zeta potential of the phosphor particles 101 covered with the third layer 104 and further covered with the fourth layer 105 is a negative value. As described above, the adhesion between the first layer 102 and the phosphor particles 101 is enhanced, so that even when the phosphor particles 101 expand and contract by heating and cooling, the first layer 102 and the phosphor particles. It becomes difficult for a gap to be generated between the first layer 102 and the first layer 102. Thereby, the moisture resistance of the covering fluorescent substance 100 improves more.

  On the other hand, the second layer 103 includes a hydrophobic substituent. The second layer 103 is preferably formed from a condensate of at least one compound selected from a metal alkoxide and a partial hydrolysis condensate thereof. In this case, the metal alkoxide has the following chemical formula (2 It is preferable that the metal alkoxide shown by this is contained.

M ² (R ² ) _nx (R ³ ) _x (2)
In the chemical formula ^{(2), M} 2 is a metal atom selected Si, Ti, Al, Zr, Ge, from Y.

R ² is a functional group involved in the hydrolysis-condensation reaction, and when there are a plurality of R ² in one molecule, they may be the same as or different from each other. This functional group is preferably a functional group selected from an alkoxide group, a hydroxyl group and a chloro group.

R ³ is a substituent having hydrophobicity (water repellency), and when a plurality of R ³ are present in one molecule, they may be the same as or different from each other. This substituent is preferably a substituent selected from a long-chain hydrocarbon group and a fluorine-containing hydrocarbon group, and in particular, — (CH ₂ ) _y —CH ₃ and — (CH ₂ ) ₂ — (CF ₂ ) _z. A substituent selected from —CF ₃ is preferred.

— (CH ₂ ) _y —CH ₃ is a long-chain hydrocarbon group composed of a C atom and an H atom. In order to improve the water repellency of the coated phosphor 100, y in the long-chain hydrocarbon group is particularly preferably an integer of 2 or more.

— (CH ₂ ) ₂ — (CF ₂ ) _z —CF ₃ is a fluorine-containing hydrocarbon group having a —CH ₂ —CH ₂ — bond interposed between the metal atom M ² and the —CF— group as a linker. is there. Z in the fluorine-containing hydrocarbon group is particularly preferably an integer of 1 or more in order to improve the water repellency of the coated phosphor 100.

In the chemical formula (2), n is a number equal to the valence of the metal element M ^2. x is an integer of 1 or more and satisfies the relationship of n> x. That is, the metal alkoxide represented by the chemical formula (2) includes at least one functional group involved in the hydrolysis condensation reaction in one molecule and at least one substituent having hydrophobicity in one molecule.

  Specific examples of the metal alkoxide represented by the chemical formula (2) and having a long-chain hydrocarbon group include propyltrimethoxysilane, butyltrimethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane, propyltriethoxysilane, and butyl. Examples include triethoxysilane, hexyltriethoxysilane, and decyltriethoxysilane. Specific examples of the metal alkoxide represented by the chemical formula (2) and having a fluorine-containing hydrocarbon group include trifluoropropyltrimethoxysilane and heptadecafluorodecyltrimethoxysilane.

  The at least one compound selected from the metal alkoxide represented by the chemical formula (2) and the partial hydrolysis condensate thereof may be only the metal alkoxide as described above, or only the partial hydrolysis condensate of the metal alkoxide. Alternatively, it may be a mixture of a metal alkoxide and a partial hydrolysis condensate of metal alkoxide.

  From the viewpoint of particularly improving the moisture resistance of the coated phosphor, the second layer 103 is only a condensate of at least one compound selected from a metal alkoxide represented by chemical formula (2) and a partial hydrolysis condensate thereof. Preferably it is formed from.

  The at least one compound selected from a metal alkoxide for forming the second layer 103 and a partially hydrolyzed condensate thereof (hereinafter sometimes referred to as a metal alkoxide) is represented by chemical formula (2). Other metal alkoxides and the like may be contained together with the metal alkoxide and the like. The metal alkoxide other than the metal alkoxide represented by the chemical formula (2) is preferably at least one compound selected from the metal alkoxide represented by the chemical formula (1) and a partial hydrolysis condensate thereof. That is, the second layer 103 includes at least one compound selected from a metal alkoxide represented by the chemical formula (2) and a partial hydrolysis condensate thereof, a metal alkoxide represented by the chemical formula (1) and a partial hydrolysis thereof. It is preferably formed from a condensate of a mixture with at least one compound selected from decomposition condensates. In a layer formed by the condensation reaction of these metal alkoxides and the like on the surface of the first layer 102, a hydrophobic substituent derived from the metal alkoxide represented by the chemical formula (2) is present on the outer surface side. It becomes unevenly distributed. This is considered to be because the surface energy of the substituent having hydrophobicity is high. For this reason, the second layer 103 having sufficiently high water repellency is formed. In the layer formed by the condensation reaction of these metal alkoxides or the like on the surface of the first layer 102, there may be a portion where a hydrophobic substituent does not exist on the phosphor particle side. This part constitutes a part of the first layer 102. By utilizing this, the fourth layer 105 is formed simultaneously with the second layer 103 by using the metal alkoxide represented by the chemical formula (1-2) as the metal alkoxide represented by the chemical formula (1). It is also possible to do. Further, the second layer 103 can be formed simultaneously with the first layer 102 by reacting these metal alkoxides and the like on the surface of the phosphor particles 101.

  When the second layer 103 is formed from a condensate of a mixture of the metal alkoxide represented by the chemical formula (2) and the metal alkoxide represented by the chemical formula (1), the first layer is formed during the condensation reaction. The ratio of the metal alkoxide represented by the chemical formula (2) to the total of these metal alkoxides and the like supplied on the surface of 102 is preferably 30 mol% or more. This mole fraction is a value based on the number of moles of metal atoms constituting the metal alkoxide or the like.

  The second layer 103 is also preferably formed from a silazane compound represented by the following chemical formula (3).

_{^{(R 4) 3 -Si-NH}} -Si (R 4) 3 ... (3)
In the chemical formula (3), R ⁴ is an alkyl group, and a plurality of R ⁴ present in one molecule may be the same as or different from each other. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group.

  When the silazane compound represented by the chemical formula (3) reacts with a hydroxyl group such as silanol on the surface of the first layer 102, ammonia is generated and a Si—O—Si bond is formed, whereby the surface of the first layer 102 is formed. A long-chain hydrocarbon group is introduced on the top to form the second layer 103. Such a layer composed of substituents introduced on the surface of the first layer 102 is also included in the concept of the second layer 103.

  Specific examples of the silazane compound represented by the chemical formula (3) include hexamethyldisilazane, hexaethyldisilazane, hexapropyldisilazane, hexahexyldisilazane, and the like.

  The coated phosphor 100 according to the present embodiment can be manufactured by an appropriate method. Specific examples of the method for producing the coated phosphor 100 include the following sol-gel coating method, spray drying method, and fluidized bed coating method.

  In the sol-gel coating method, phosphor particles 101 are first added to a liquid medium. Subsequently, at least one compound selected from the metal alkoxide represented by the chemical formula (1) and the partial hydrolysis condensate thereof or a solution containing these is added to the medium while the medium is stirred. As a result, the hydrolysis and condensation reaction of the compound proceeds, and a metal oxide composed of the hydrolysis and condensation product of the compound is deposited on the surface of the phosphor particle 101, thereby forming the first layer 102. .

  When the first layer 102 is composed of a plurality of layers having different compositions, a metal oxide composed of hydrolysis condensates of compounds having different compositions is sequentially deposited by repeating the above-described method. Layer 102 may be formed.

  Specific examples of the liquid medium used in the sol-gel coating method include alcohol solvents such as methanol, ethanol, propanol, isopropanol, and butanol; toluene, xylene, cyclohexane, methylcyclohexane, petroleum ether, petroleum benzine, gasoline, naphtha, and the like. Hydrocarbon solvents such as: ether solvents such as diethyl ether and tetrahydrofuran; ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as acetone and methyl ethyl ketone. Of these liquid media, only one kind may be used alone, or two or more kinds may be used in combination.

  In the sol-gel coating method, it is preferable that a stoichiometric amount or an excessive amount of water required for the progress of the hydrolysis condensation reaction is added to the liquid medium. Water is added to the liquid medium at an appropriate timing. For example, whether water is added to the liquid medium in which the phosphor particles 101 are dispersed or added to the liquid medium together with the metal alkoxide having a relatively low hydrolysis rate, the liquid medium is separated from the metal alkoxide. May be added. Alternatively, after the metal alkoxide is adhered to the surface of the phosphor particle 101, the solvent is distilled off or the phosphor particle 101 to which the metal alkoxide is adhered is recovered by filtration, and then the phosphor particle 101 is vapor phase or When contacted with liquid phase water, the hydrolysis condensation reaction of the metal alkoxide proceeds on the surface of the phosphor particles 101, whereby the first layer 102 is formed.

  In the spray drying method, in a liquid medium in which the phosphor particles 101 are dispersed, at least one compound selected from a metal alkoxide represented by the chemical formula (1) and a partially hydrolyzed condensate thereof is added. A solution containing is added. By spraying the liquid prepared in this way, droplets containing the compound as well as the phosphor particles 101 are obtained. By drying the droplets, the compound adheres to the surface of the phosphor particles 101 and the hydrolysis condensation reaction of the compound proceeds, whereby the first layer 102 is formed.

  When the first layer 102 is composed of a plurality of layers having different compositions, a metal oxide composed of hydrolysis condensates of compounds having different compositions is sequentially deposited by repeating the above-described method. Layer 102 may be formed.

  As the liquid medium in this spray drying method, the same liquid medium as in the sol-gel coating method can be used.

  In the fluidized bed coating method, at least one compound selected from the metal alkoxide represented by the chemical formula (1) and a partial hydrolysis condensate thereof, or a solution containing them is sprayed, or the boiling point of the metal alkoxide is When it is low, the metal alkoxide is vaporized. Such a spray-like solution or vaporized metal alkoxide is supplied toward the phosphor particles 101 together with an inert gas such as nitrogen or argon. Then, in a state where the phosphor particles 101 are fluidized, a spray solution or a vaporized metal alkoxide adheres to the surface of the phosphor particles 101. At the same time or thereafter, the surface of the phosphor particles 101 is contacted with a stoichiometric amount or an excessive amount of water in a sprayed state or a gas phase. As a result, a hydrolysis condensation reaction of at least one compound selected from the metal alkoxide represented by the chemical formula (1) and a partial hydrolysis condensate thereof proceeds on the surface of the phosphor particles 101, and the first layer 102 is formed.

  When the first layer 102 is composed of a plurality of layers having different compositions, a metal oxide composed of hydrolysis condensates of compounds having different compositions is sequentially deposited by repeating the above-described method. Layer 102 may be formed.

  Even when the second layer 103 is formed, the second layer 103 can be formed by a method based on the case of the first layer 102.

  Further, a metal alkoxide or the like for forming the first layer 102 and a metal alkoxide or the like for forming the second layer 103 are simultaneously supplied and reacted on the surface of the phosphor particle 101 by the above method. Then, since the surface energy of the hydrophobic substituent is high as described above, the first layer 102 and the second layer 103 can be formed simultaneously.

  Regardless of which method is used to form the first layer 102 and the second layer 103, a catalyst is used to promote the hydrolysis reaction or condensation reaction of the metal alkoxide and the partial hydrolyzate of the metal alkoxide. Is preferred. In this case, the first layer 102 and the second layer 103 are formed at a lower temperature and in a shorter time. Specific examples of the catalyst include acids such as hydrochloric acid, nitric acid, sulfuric acid and acetic acid; bases such as sodium hydroxide, ammonia and tetramethylammonium hydroxide; hexanoic acid, octanoic acid, 2-ethylhexanoic acid and naphthenic acid. Carboxylic acid metal salts such as zinc salts of carboxylic acids; aluminum triethoxide, aluminum tri-n-propoxide, aluminum triisopropoxide, aluminum tri-n-butoxide, aluminum alkoxides such as aluminum isobutoxide, and the like Partially hydrolyzed condensates of diisopropoxy (acetylacetonato) aluminum, di-n-butoxy (acetylacetonato) aluminum, tris (acetylacetonato) aluminum, diisopropoxy (ethylacetoaceto) aluminum, di- n Examples include aluminum chelate compounds such as butoxy (ethylacetoacetato) aluminum and n-butoxybis (ethylacetoacetato) aluminum; quaternary ammonium salts such as tetramethylammonium acetate; and amino compounds such as triethanolamine. . As the catalyst, amino group-containing alkoxysilanes such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and 3- (N-2-aminoethyl) propyltrimethoxysilane, which are themselves metal alkoxides, are catalysts. An amount may be used together. The catalyst may be added to the reaction system by any method.

  When the first layer 102 and the second layer 103 are formed by the spray drying method or the fluidized bed coating method, the solvent is removed by further heating the first layer 102 and the second layer 103. It is preferable. The heating temperature in this case is preferably a temperature at which the solvent can be sufficiently removed by drying. Thereby, even when the degree of progress of the hydrolysis condensation reaction in the first layer 102 and the second layer 103 is not sufficient, the hydrolysis condensation reaction can be further advanced.

  The first layer 102 and the second layer 103 may be further subjected to heat treatment. By such a high temperature heat treatment, the hydrolysis condensation reaction in the first layer 102 and the second layer 103 further proceeds, and the reaction can be completed. The heating temperature in this high-temperature heat treatment is not particularly limited, but is preferably in the range of 60 to 600 ° C., and the heating time is not particularly limited, but is preferably in the range of 0.5 to 3 hours. It is preferable that the first layer 102 and the second layer 103 formed by the spray drying method or the fluidized bed coating method are further subjected to a heat treatment at a higher temperature after the heat treatment for removing the solvent by drying. . When the first layer 102 and the second layer 103 are formed by the sol-gel coating method, the phosphor particles 101 on which the first layer 102 and the second layer 103 are formed are recovered from the solvent by filtration. It is preferable that high-temperature heat treatment is performed.

  Although there is no restriction | limiting in the thickness of the 1st layer 102 and the 2nd layer 103, the moisture resistance of the covering fluorescent substance 100 is fully ensured, and the favorable light emission characteristic of the covering fluorescent substance 100 is fully ensured. From the viewpoint, the total thickness of the first layer 102 and the second layer 103 is preferably in the range of 10 to 1000 nm. The thickness of the first layer 102 is preferably in the range of 5 to 600 nm, and the thickness of the second layer 103 is preferably in the range of 5 to 400 nm. Further, when the first layer 102 includes a plurality of layers including the third layer 104 and the fourth layer 105, the thickness of the third layer 104 is preferably 300 nm or less, The thickness of the layer 105 is preferably 400 nm or less.

  The coated phosphor 100 according to the present embodiment exhibits extremely excellent moisture resistance. Simply forming a hydrophobic film or a water-repellent film on the surface of the phosphor particles 101 does not sufficiently improve the moisture resistance of the phosphor particles 101. On the other hand, in the coated phosphor 100 according to the present embodiment, the film structure is designed in consideration of the process in water vapor transmission and various characteristics of the moisture-proof film contributing to the process. That is, in the present embodiment, the phosphor particles 101 are covered with a layer capable of blocking water vapor, so that the moisture resistance of the phosphor is sufficiently improved.

  In general, a process in which water permeating into a substance diffuses in the substance is known as water vapor transmission. For this reason, it is effective to suppress the penetration and diffusion of moisture into the substance for blocking water vapor. Important parameters regarding the amount of water vapor permeation include the solubility coefficient of water, diffusion coefficient, and diffusion distance. Accordingly, the moisture resistance of the phosphor particles 101 having a moisture-proof coating includes water solubility (water solubility coefficient), film density (water diffusion coefficient), and film thickness (water diffusion). Distance) is considered to be greatly involved. From this, as one of the specific measures for increasing the water vapor barrier property of the coating on the phosphor particles 101, the water repellency of the outermost surface of the coating is improved, the density of the coating is improved, and the thickness of the coating is further increased. It is also possible.

  However, if the thickness of the coating is increased, the light emission characteristics of the phosphor may be impaired due to attenuation and scattering when light passes through the coating. From the viewpoint of such optical characteristics, in order to increase the diffusion distance of water. There is a limit to increasing the thickness of the coating.

  In the present embodiment, the second layer 103 forms the first layer 102 having high density and high water repellency on the outermost surface of the coated phosphor 100. For this reason, when water vapor or water comes into contact with the coated phosphor 100, the water or the like is repelled on the surface of the second layer 103, thereby preventing moisture from penetrating into the phosphor 100. When the external environment is high temperature, the solubility of water in the second layer 103 is increased, so that water easily penetrates into the second layer 103. Even in this case, the first having high barrier properties. The layer 102 blocks moisture penetration. In this way, the arrival of moisture to the phosphor particles 101 is prevented. Therefore, the coated phosphor 100 exhibits high moisture resistance, and the possibility that the light emission characteristics of the coated phosphor 100 are impaired is small.

[Light emitting device]
The light emitting device according to the present embodiment will be described. As shown in FIGS. 2 and 3, the light emitting device 1 includes an LED chip 10 that is a light emitting element, a mounting substrate 20, an optical member 60, a sealing portion 50, and a wavelength conversion member (color conversion member) 70. As will be described later, the wavelength conversion member (color conversion member) 70 includes the coated phosphor 100 according to the present embodiment.

  The LED chip 10 is mounted on the mounting substrate 20. The shape of the mounting substrate 20 is a rectangular plate shape in plan view. A pair of conductor patterns 23 for supplying power to the LED chip 10 are formed on the first surface facing the thickness direction of the mounting substrate 20, and the LED chip 10 is further mounted on the first surface. The LED chip 10 and the conductor pattern 23 are electrically connected by a bonding wire 14. The optical member 60 is a dome-shaped member, and is fixed on the first surface of the mounting substrate 20. The LED chip 10 is accommodated between the optical member 60 and the mounting substrate 20. The optical member 60 has a function of controlling the orientation of light emitted from the LED chip 10. The sealing part 50 is formed from a translucent sealing material. The sealing portion 50 is filled in a space surrounded by the optical member 60 and the mounting substrate 20. The sealing portion 50 seals the LED chip 10 and a plurality of (in this embodiment, two) bonding wires 14. The wavelength conversion member 70 is formed in a dome shape so as to surround the optical member 60. When the LED chip 10 emits light, the wavelength conversion particles 71 in the wavelength conversion member 70 are excited by the light emitted from the LED chip 10 (excitation light), and fluorescence having a longer wavelength than the excitation light (the emission color of the LED chip 10 and Emits converted light consisting of light of different colors. Between the optical member 60 and the wavelength conversion member 70, a gap 80 in which a gas such as air is enriched is interposed. On the first surface of the mounting substrate 20, an annular weir 27 that surrounds the outer periphery of the optical member 60 is formed. The dam portion 27 is formed so as to protrude from the first surface. Therefore, when the optical member 60 is fixed to the mounting substrate 20, even if the sealing material overflows from the space surrounded by the optical member 60 and the mounting substrate 20, the sealing material is blocked by the dam portion 27. I can be dammed up.

  The main light emission peak of the LED chip 10 is preferably in the range of 350 nm to 470 nm. Examples of such an LED chip 10 include a GaN-based blue LED chip that emits blue light and a near-ultraviolet LED chip that emits near-ultraviolet light.

  In a GaN blue LED chip, an n-type SiC substrate having a lattice constant or crystal structure closer to that of GaN than a sapphire substrate and having conductivity is used as a crystal growth substrate. On the SiC substrate, for example, a light-emitting portion having a double hetero structure is formed. The light emitting portion is formed by, for example, an epitaxial growth method (for example, MOVPE method) using a GaN-based compound semiconductor material or the like as a raw material. The LED chip 10 includes a cathode electrode on the surface facing the first surface of the mounting substrate 20 and an anode electrode on the opposite surface. The cathode electrode and the anode electrode are constituted by, for example, a laminated film of a Ni film and an Au film. The material for the cathode electrode and the anode electrode is not particularly limited, and may be any material as long as good ohmic characteristics can be obtained. For example, Al may be used.

  The structure of the LED chip 10 is not limited to the above structure. For example, after a light emitting part or the like is formed by epitaxial growth on a crystal growth substrate, a support substrate such as an Si substrate that supports the light emitting part is fixed to the light emitting part, and then the crystal growth substrate is removed. The LED chip 10 may be formed.

  The mounting board 20 includes a rectangular heat transfer plate 21 and a wiring board 22. The heat transfer plate 21 is formed from a heat conductive material. The LED chip 10 is mounted on the heat transfer plate 21. The wiring board 22 is, for example, a rectangular flexible printed wiring board. The wiring board 22 is fixed on the heat transfer plate 21 via, for example, a polyolefin-based fixing sheet 29. A rectangular window hole 24 that exposes the mounting position of the LED chip 10 on the heat transfer plate 21 is formed at the center of the wiring board 22. Inside this window hole 24, the LED chip 10 is mounted on the heat transfer plate 21 via a submount member 30 described later. Therefore, the heat generated in the LED chip 10 is conducted to the submount member 30 and the heat transfer plate 21 without passing through the wiring board 22.

  The wiring substrate 22 includes an insulating base material 221 made of a polyimide film and a pair of conductor patterns 23 for supplying power to the LED chip 10 formed on the insulating base material 221. Furthermore, the wiring board 22 includes a protective layer 26 that covers each conductor pattern 23 and covers a portion on the insulating base material 221 where the conductor pattern 23 is not formed. The protective layer 26 is formed of, for example, a white resist (resin) having light reflectivity. In this case, even if light is radiated from the LED chip 10 toward the wiring substrate 22, the light is reflected by the protective layer 26, thereby suppressing light absorption in the wiring substrate 22. Thereby, the light extraction efficiency from the LED chip 10 to the outside is improved, and the light output of the light emitting device is improved. Each conductor pattern 23 is formed in an outer peripheral shape slightly smaller than half of the outer peripheral shape of the insulating base material 221. The insulating base material 221 may be formed of an FR4 substrate, an FR5 substrate, a paper phenol resin substrate, or the like.

  Each conductor pattern 23 includes two terminal portions 231 each having a rectangular shape in plan view. The terminal portion 231 is located in the vicinity of the window hole 24 of the wiring board 22, and the bonding wire 14 is connected to the terminal portion 231. Each conductor pattern 23 further includes one external connection electrode portion 232 having a circular shape in plan view. The external connection electrode portion 232 is located near the outer periphery of the wiring board 22. The conductor pattern 23 is composed of, for example, a laminated film of a Cu film, a Ni film, and an Au film.

  The protective layer 26 is patterned so that each conductor pattern 23 is partially exposed from the protective layer 26. In the vicinity of the window hole 24 of the wiring board 22, the terminal portion 231 in each conductor pattern 23 is exposed from the protective layer 26. Further, the external connection electrode portions 232 in each conductor pattern 23 are exposed from the protective layer 26 near the outer periphery of the wiring board 22.

  The LED chip 10 is mounted on the heat transfer plate 21 via the submount member 30 as described above. The submount member 30 relieves stress acting on the LED chip 10 due to a difference in linear expansion coefficient between the LED chip 10 and the heat transfer plate 21. The submount member 30 is formed in a rectangular plate shape having a size larger than the chip size of the LED chip 10.

  The submount member 30 has not only a function of relieving the stress but also a heat conduction function of conducting heat generated in the LED chip 10 in a wider range than the chip size of the LED chip 10 in the heat transfer plate 21. Yes. In the light emitting device 1 according to the present embodiment, the LED chip 10 is mounted on the heat transfer plate 21 via the submount member 30, so that the heat generated by the LED chip 10 passes through the submount member 30 and the heat transfer plate 21. In addition, the heat acting on the LED chip 10 due to the difference in linear expansion coefficient between the LED chip 10 and the heat transfer plate 21 is relieved.

  The submount member 30 is made of, for example, AlN having a relatively high thermal conductivity and an insulating property.

  The cathode electrode of the LED chip 10 is superposed on the submount member 30, and the cathode electrode is bonded with an electrode pattern (not shown) connected to the cathode electrode and a metal fine wire (for example, a gold fine wire, an aluminum fine wire, etc.). It is electrically connected to one of the two conductor patterns 23 through the wire 14. The LED chip 10 is electrically connected through a bonding wire 14 to a conductor pattern 23 that is not connected to the cathode electrode.

  For joining the LED chip 10 and the submount member 30, for example, solder such as SnPb, AuSn, SnAgCu, silver paste, or the like is used. It is particularly preferable to use lead-free solder such as AuSn or SnAgCu. When the submount member 30 is made of Cu and AuSn is used for bonding the LED chip 10 and the submount member 30, Au or Ag is previously formed on the surfaces of the submount member 30 and the LED chip 10 to be bonded to each other. It is preferable to perform a pretreatment for forming a metal layer made of For joining the submount member 30 and the heat transfer plate 21, for example, lead-free solder such as AuSn or SnAgCu is preferably used. When AuSn is used for joining the submount member 30 and the heat transfer plate 21, a pretreatment for forming a metal layer made of Au or Ag in advance on the surface of the heat transfer plate 21 to be joined with the submount member 30. Is preferably applied.

  The material of the submount member 30 is not limited to AlN, and any material may be used as long as the linear expansion coefficient is relatively close to 6H—SiC, which is the material for the crystal growth substrate, and the thermal conductivity is relatively high. For example, composite SiC, Si, Cu, CuW, or the like may be employed as the material of the submount member 30. Since the submount member 30 has the above-described heat conduction function, the area of the surface of the heat transfer plate 21 facing the LED chip 10 is the area of the surface of the LED chip 10 facing the heat transfer plate 21. It is desirable that it be sufficiently large.

  In the light emitting device 1 according to this embodiment, the heat transfer is larger than the dimension from the surface on the LED chip 10 side facing the thickness direction of the heat transfer plate 21 to the surface on the LED chip 10 side facing the thickness direction of the protective layer 26. The dimension from the surface of the plate 21 to the surface on the LED chip 10 side facing the thickness direction of the submount member 30 is larger. The thickness dimension of the submount member 30 is set so as to have such a positional relationship. For this reason, the light emitted from the LED chip 10 is suppressed from being absorbed by the wiring board 22 through the inside of the window hole 24 of the wiring board 22. Thereby, the light extraction efficiency from the LED chip 10 to the outside is further improved, and the light output of the light emitting device is further improved.

  Note that a reflective film that reflects light emitted from the LED chip 10 is formed around the position where the LED chip 10 is disposed on the surface of the submount member 30 facing the thickness direction of the LED chip 10. Good. In this case, the light emitted from the LED chip 10 is prevented from being absorbed by the submount member 30. Thereby, the light extraction efficiency from the LED chip 10 to the outside is further improved, and the light output of the light emitting device is further improved. The reflective film is composed of a laminated film of a Ni film and an Ag film, for example.

  A silicone resin is mentioned as a sealing material which is a material for forming the above-mentioned sealing part 50. For example, an acrylic resin, glass, or the like may be used instead of the silicone resin.

  The optical member 60 is formed from a light transmissive material (eg, silicone resin, glass, etc.). In particular, when the optical member 60 is formed of a silicone resin, a difference in refractive index and a difference in linear expansion coefficient between the optical member 60 and the sealing portion 50 can be reduced.

  The light emission surface 602 (surface facing the side opposite to the LED chip 10) of the optical member 60 is light emitted from the light incident surface 601 (surface facing the LED chip 10 side) into the optical member 60. A convex curved surface is formed so as not to be totally reflected at the boundary between the surface 602 and the gap 80. The optical member 60 is disposed so that the optical axis of the LED chip 10 coincides. Therefore, the light emitted from the LED chip 10 and incident on the light incident surface 601 of the optical member 60 can easily reach the wavelength conversion member 70 without being totally reflected at the boundary between the light emitting surface 602 and the gap layer 80. The total luminous flux from the light emitting device 1 increases. The optical member 60 is formed to have a uniform thickness along the normal direction regardless of the position.

  The wavelength conversion member 70 has a light incident surface 701 (a surface facing the LED chip 10) formed in a shape along the light emitting surface 602 of the optical member 60. Therefore, regardless of the position of the light emitting surface 602 of the optical member 60, the distance between the light emitting surface 602 of the optical member 60 and the wavelength conversion member 70 in the normal direction is a substantially constant value. The wavelength conversion member 70 is formed so that the thickness along the normal direction is uniform regardless of the position. The wavelength conversion member 70 is fixed to the mounting substrate 20 with, for example, an adhesive (for example, silicone resin, epoxy resin).

  Light emitted from the LED chip 10 enters the wavelength conversion member 70 from the light incident surface 701, and out of the wavelength conversion member 70 through the light emission surface (surface opposite to the LED chip 10) 701 of the wavelength conversion member 70. Emitted. When light passes through the wavelength conversion member 70, a part of this light is wavelength-converted by the phosphor particles 101 in the wavelength conversion member 70. As a result, light of a color corresponding to the combination of the light emitted from the LED chip 10 and the type of the phosphor particles 101 in the wavelength conversion member 70 is emitted from the light emitting device 1.

  As shown in FIG. 1, the wavelength conversion member 70 includes a translucent medium 72 and a plurality of wavelength conversion particles 71 dispersed in the translucent medium 72. Examples of the wavelength conversion particles 71 include phosphor particles 101 and phosphor particles 101 having a coating. At least a part of the wavelength conversion particle 71 is the coated phosphor 100 according to the present embodiment. The wavelength conversion member 70 may contain only the coated phosphor 100 according to the present embodiment as the wavelength conversion particle 71, and other than the coated phosphor 100 according to the present embodiment and the coated phosphor 100 according to the present embodiment. May be contained.

  In the case where the light emitting device 1 emits white light, when the LED chip 10 in the light emitting device 1 is a blue LED chip that emits blue light, the wavelength conversion particle 71 in the wavelength conversion member 70 is formed from, for example, a red phosphor. And particles formed from a green phosphor are used in combination. Or only the particle | grains formed from yellow fluorescent substance as the wavelength conversion particle | grains 71 may be used. Alternatively, as the wavelength conversion particles 71, particles formed from a green phosphor and particles formed from an orange phosphor may be used in combination. Alternatively, as the wavelength conversion particles 71, particles formed from a yellow-green phosphor and particles formed from an orange phosphor may be used in combination. In any case, it is preferable that at least a part of the wavelength conversion particles 71 is the coated phosphor 100 according to the present embodiment, and in particular, all of the wavelength conversion particles 71 are the coated phosphor 100 according to the present embodiment. In these cases, the blue light emitted from the LED chip 10 without being wavelength-converted and the light wavelength-converted by the wavelength conversion particles 71 of the wavelength conversion member 70 are the light emission surface (outer surface) of the wavelength conversion member 70. 70b will be emitted, thereby emitting white light.

  When the light emitting device 1 emits white light and the LED chip 10 in the light emitting device 1 is an ultraviolet LED chip that emits ultraviolet light, for example, as the wavelength conversion particles 71, particles formed from a red phosphor, a green phosphor And particles formed from blue phosphor are used in combination. It is preferable that at least a part of the wavelength conversion particles 71 is the coated phosphor 100 according to the present embodiment, and in particular, all of the wavelength conversion particles 71 are the coated phosphor 100 according to the present embodiment. In this case, the ultraviolet light emitted without wavelength conversion from the LED chip 10 and the light whose wavelength has been converted by the wavelength conversion particles 71 of the wavelength conversion member 70 are the light emission surface (outer surface) 70b of the wavelength conversion member 70. Through which white light is emitted.

  The particle diameter of the wavelength conversion particle 71 is not particularly limited. However, the larger the average particle diameter of the wavelength conversion particle 71, the smaller the defect density in the wavelength conversion particle 71, the less energy loss during light emission, and the light emission efficiency. Get higher. For this reason, from the viewpoint of improving the light emission efficiency, the average particle diameter of the wavelength conversion particles 71 is preferably 5 μm or more. This average particle diameter is a value measured by a laser diffraction / scattering particle size distribution measuring apparatus.

  The refractive index of the translucent medium 72 is preferably smaller than the refractive index of the wavelength conversion particles 71. Examples of the material of the translucent medium 72 include a silicon compound having a siloxane bond and glass. Since these materials are excellent in heat resistance and light resistance (durability to light having a short wavelength such as blue to ultraviolet light), the light is transmitted by light in a wavelength range from blue light to ultraviolet light, which is excitation light of the wavelength conversion particle 71. Deterioration of the medium 72 is suppressed. Examples of silicon compounds include composites formed by crosslinking a silicone resin, a hydrolyzed condensate of organosiloxane, a condensate of organosiloxane, etc. by a known polymerization method (addition polymerization such as hydrosilylation, radical polymerization, etc.). Resin. As the translucent medium 72, for example, an acrylic resin or an organic / inorganic hybrid material formed by mixing and bonding an organic component and an inorganic component at the nm level or molecular level may be employed.

  The content of the wavelength conversion particle 71 in the wavelength conversion member 70 takes into consideration the types of the wavelength conversion particle 71 and the translucent medium 72, the dimensions of the wavelength conversion member 70, the wavelength conversion capability required for the wavelength conversion member 70, and the like. For example, it is in the range of 5% by mass to 30% by mass.

  When the wavelength conversion member 70 is irradiated with the excitation light of the wavelength conversion particle 71, the wavelength conversion particle 71 absorbs the excitation light and emits fluorescence having a longer wavelength than the excitation light. Thereby, when light passes through the wavelength conversion member 70, the wavelength of this light is converted by the wavelength conversion particles 71.

  In the light emitting device 1 configured as described above, the wavelength conversion member 70 includes the coated phosphor 100 according to the present embodiment, so that the moisture resistance and durability of the wavelength conversion member 70 are increased. The operation of the light emitting device 1 can be stabilized.

[Example 1]
(1) Preparation of sample particle A 468 parts by mass of isopropanol and 0.7 part by mass of ion-exchanged water were mixed, and phosphor particles ((Sr, Ca, Ba) ₃ SiO ₅ : Eu, laser diffraction were obtained. A phosphor dispersion liquid was prepared by dispersing 61 parts by mass of a particle size distribution measuring apparatus (model number SALD2000, manufactured by Shimadzu Corporation) with an average particle diameter of 15 μm.

  An aluminum isopropoxide solution is obtained by mixing 2.0 parts by mass of aluminum isopropoxide and 468 parts by mass of isopropanol and applying ultrasonic waves to the resulting mixture using an ultrasonic cleaner. It was.

  While stirring the phosphor dispersion, an aluminum isopropoxide solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours. Then, after leaving this solution still for a while, the supernatant was removed, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour. As a result, sample particles A were obtained.

  Furthermore, when the sample particle A was cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was uniformly coated with a coating without cracks, It was confirmed to be 70 nm.

  The depth direction analysis of the coating film of the sample particle A by X-ray photoelectron spectroscopic analysis was performed. At this time, using ESCALAB220-XL manufactured by Thermo Fisher Scientific, the particles were analyzed by irradiating X-rays in a 1 mm square analysis area. In the depth direction analysis, the sample surface was cut by sputtering with argon ion irradiation and then analyzed in the deep part to calculate the element concentration (atm.%) In the coating at a specific depth. As a result, it was confirmed that the aluminum element was distributed in the coating of the sample particles A.

(2) Preparation of sample particle B 487 parts by mass of isopropanol, 22 parts by mass of tetraethoxysilane, 4.6 parts of ion-exchanged water, and 1.0 part by mass of 0.1N hydrochloric acid aqueous solution were mixed, and the resulting liquid was mixed. By stirring at room temperature for 48 hours, a tetraethoxysilane hydrolyzed solution was prepared.

  A phosphor dispersion liquid was prepared by mixing 487 parts by mass of isopropanol and 54 parts by mass of sample particles A.

  The tetraethoxysilane hydrolyzed solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant liquid was removed from the liquid, and the remaining liquid was filtered to obtain a solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour, and further heat-treated at 300 ° C. for 1 hour. Thereby, sample particles B were obtained.

  When the sample particle B was cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particle was coated with a uniform coating without cracks, It was confirmed to be 160 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that the elements of the coating of the sample particle B were distributed in the order of silicon and aluminum from the surface side.

(3) Production of coated phosphor: 477 parts by mass of isopropanol, 11 parts by mass of C ₈ F ₁₇ -C ₂ H ₄ —Si (—OCH ₃ ) ₃ (TSL-8233 manufactured by Momentive Performance Materials), ion-exchanged water 0.07 part and 0.6 mass part of 0.1 N hydrochloric acid aqueous solution were mixed and stirred at room temperature for 24 hours to prepare a fluorosilane-based water repellent solution.

  A phosphor dispersion liquid was prepared by mixing 500 parts by mass of isopropanol and 11 parts by mass of sample particles B11.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 210 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that the elements were distributed in the order of fluorine, silicon, and aluminum from the surface side in the coated phosphor particle coating.

[Example 2]
A long-chain alkyl-based water repellent solution was prepared by mixing 440 parts by mass of isopropanol and 99 parts by mass of hexamethylenedisilanezan (HMDS3 manufactured by Shin-Etsu Chemical Co., Ltd.).

  A phosphor dispersion liquid was prepared by mixing 11 parts by mass of sample particles B with 450 parts by mass of isopropanol.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion, followed by stirring at room temperature for 20 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this solution, and 700 parts by mass of isopropyl alcohol was added to the remaining solution, followed by stirring for 2 hours. Subsequently, the supernatant was again removed from this solution, and 700 parts by mass of isopropyl alcohol was added to the remaining solution, followed by stirring for 2 hours. Thereby, ammonia which is a by-product was removed from the liquid. The solid content was separated by filtering this liquid. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 190 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that the elements were distributed in the order of carbon, silicon, and aluminum from the surface side in the coated phosphor particle coating.

[Example 3]
476 parts by weight of _{isopropanol, C 8 F 17 -C 2 H} 4 -Si (-OCH 3) 3 ( Momentive Performance Materials Inc. TSL-8233) 19 parts by mass of tetraethoxysilane 7.5 parts by weight, ion-exchange 1.4 parts of water and 1.4 parts of a 0.1 N hydrochloric acid aqueous solution were mixed and stirred at room temperature for 24 hours to prepare a fluorosilane-based water repellent solution.

  A phosphor dispersion liquid was prepared by mixing 476 parts by mass of isopropanol and 19 parts by mass of sample particles A.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 180 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that the elements were distributed in the order of fluorine, silicon, and aluminum from the surface side in the coated phosphor particle coating.

[Example 4]
477 parts by mass of isopropanol, 11 parts by mass of C ₈ F ₁₇ —C ₂ H ₄ —Si (—OCH ₃ ) ₃ (Momentive Performance Materials TSL-8233), 0.07 parts by mass of ion-exchanged water, 0. A fluorosilane-based water repellent solution was prepared by mixing 0.6 parts by mass of 1N hydrochloric acid aqueous solution and stirring at room temperature for 24 hours.

  A phosphor dispersion liquid was prepared by mixing 500 parts by mass of isopropanol and 11 parts by mass of sample particles A11.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 130 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that the elements were distributed in the order of fluorine and aluminum from the surface side in the coated phosphor particle coating.

[Example 5]
(1) Preparation of sample particles C 487 parts by mass of isopropanol, 22 parts by mass of tetraethoxysilane, 4.6 parts by mass of ion-exchanged water, and 1.0 part by mass of 0.1N hydrochloric acid aqueous solution were mixed, and the mixture was stirred at room temperature for 24 hours. A tetraethoxysilane hydrolyzed solution was prepared by stirring.

487 parts by mass of isopropanol and phosphor particles ((Sr, Ca, Ba) ₃ SiO ₅ : Eu, laser diffraction particle size distribution measuring device (model number SALD2000, manufactured by Shimadzu Corporation)) 54 masses Were mixed with each other to prepare a phosphor dispersion.

  While stirring the phosphor dispersion, a tetraethoxysilane hydrolysis solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain sample particles C.

  The sample particle C was cut by FIB processing, and the cross section was observed with a transmission electron microscope (TEM). It was confirmed that.

  According to the depth direction analysis by X-ray photoelectron spectroscopy, it was confirmed that silicon was distributed in the coating of the sample particles C.

(2) Preparation Isopropanol 477 parts by weight of the coated _{phosphor, C 8 F 17 -C 2 H} 4 -Si (-OCH 3) 3 ( Momentive Performance Materials Inc. TSL-8233) 11 parts by mass, ion-exchanged water 0.07 part by mass and 0.6 part by mass of 0.1N hydrochloric acid aqueous solution were mixed and stirred at room temperature for 24 hours to prepare a fluorosilane-based water repellent solution.

  A phosphor dispersion liquid was prepared by mixing 500 parts by mass of isopropanol and 11 parts by mass of sample particles C11.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 100 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that the elements were distributed in the order of fluorine and silicon from the surface side in the coated phosphor particle coating.

[Example 6]
(1) Preparation of sample particle D 487 parts by mass of butanol and 35 parts by mass of zirconium tetranormal butoxide (Orgatechs ZA-65 manufactured by Matsumoto Trading Co., Ltd.) were mixed to prepare a zirconium tetranormal butoxide solution.

  A phosphor dispersion liquid was prepared by mixing 487 parts by weight of butanol and 54 parts by weight of sample particles A.

  A zirconium tetranormal butoxide solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant liquid was removed from the liquid, and the remaining liquid was filtered to obtain a solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour, and further heat-treated at 300 ° C. for 1 hour. Thereby, sample particles D were obtained.

  When the sample particle D was cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particle was coated with a uniform coating without cracks, and the total thickness of the coating was It was confirmed to be 180 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that the elements were distributed in the order of zirconia and aluminum from the surface side in the coating of the sample particles D.

(2) Preparation Isopropanol 477 parts by weight of the coated _{phosphor, C 8 F 17 -C 2 H} 4 -Si (-OCH 3) 3 ( Momentive Performance Materials Inc. TSL-8233) 11 parts by mass, ion-exchanged water 0.07 part and 0.6 mass part of 0.1 N hydrochloric acid aqueous solution were mixed and stirred at room temperature for 24 hours to prepare a fluorosilane-based water repellent solution.

  A phosphor dispersion was prepared by mixing 500 parts by weight of isopropanol and 11 parts by weight of sample particles D.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 230 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that the elements were distributed in the order of fluorine, zirconia, and aluminum from the surface side in the coated phosphor particle coating.

[Example 7]
(1) Preparation of sample particle E 487 parts by weight of butanol and 30 parts by weight of titanium tetranormal butoxide (Orgatechs TA-25 manufactured by Matsumoto Trading Co., Ltd.) were mixed to prepare a titanium tetranormal butoxide solution.

  A phosphor dispersion liquid was prepared by mixing 487 parts by weight of butanol and 54 parts by weight of sample particles A.

  The titanium tetranormal butoxide solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant liquid was removed from the liquid, and the remaining liquid was filtered to obtain a solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour, and further heat-treated at 300 ° C. for 1 hour. Thereby, sample particles E were obtained.

  When the sample particle D was cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particle was coated with a uniform coating without cracks, and the total thickness of the coating was It was confirmed to be 190 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that elements were distributed in the order of titanium and aluminum from the surface side in the coating of the sample particles D.

(2) Preparation Isopropanol 477 parts by weight of the coated _{phosphor, C 8 F 17 -C 2 H} 4 -Si (-OCH 3) 3 ( Momentive Performance Materials Inc. TSL-8233) 11 parts by mass, ion-exchanged water 0.07 part and 0.6 mass part of 0.1 N hydrochloric acid aqueous solution were mixed and stirred at room temperature for 24 hours to prepare a fluorosilane-based water repellent solution.

  A phosphor dispersion liquid was prepared by mixing 500 parts by mass of isopropanol and 11 parts by mass of sample particles E.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 240 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that the elements were distributed in the order of fluorine, titanium, and aluminum from the surface side in the coated phosphor particle coating.

[Example 8]
477 parts by mass of isopropanol, 5.2 parts by mass of pentafluorobutyltrimethoxysilane (CF ₃ CF ₂ CH ₂ CH ₂ Si (OCH ₃ ) ₃ ), 0.07 part of ion-exchanged water, 0.1N aqueous hydrochloric acid solution Six parts by mass were mixed and stirred at room temperature for 24 hours to prepare a fluorosilane-based water repellent solution.

  A phosphor dispersion liquid was prepared by mixing 500 parts by mass of isopropanol and 11 parts by mass of sample particles B11.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 210 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that the elements were distributed in the order of fluorine, silicon, and aluminum from the surface side in the coated phosphor particle coating.

[Example 9]
477 parts by mass of butanol and 8.9 parts by mass of pentafluorobutylzirconium trinormalbutoxide (CF ₃ CF ₂ CH ₂ CH ₂ Zr (OC ₄ H ₉ ) ₃ ) are mixed and stirred at room temperature for 24 hours to produce a fluorozirconium series. A water repellent solution was prepared.

  A phosphor dispersion was prepared by mixing 500 parts by weight of butanol and 11 parts by weight of sample particles B11.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 220 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that elements were distributed in the order of fluorine, zirconia, silicon, and aluminum from the surface side in the coated phosphor particle coating.

[Example 10]
477 parts by weight of butanol and 8.0 parts by weight of pentafluorobutyltitanium trinormal butoxide (CF ₃ CF ₂ CH ₂ CH ₂ Ti (OC ₄ H ₉ ) ₃ ) are mixed and stirred at room temperature for 24 hours to be fluorotitanium-based A water repellent solution was prepared.
A phosphor dispersion was prepared by mixing 500 parts by weight of butanol and 11 parts by weight of sample particles B11.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 220 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that elements were distributed in the order of fluorine, titanium, silicon, and aluminum from the surface side in the coated phosphor particle coating.

[Example 11]
477 parts by mass of isopropanol, 5.4 parts by mass of n-octyltriethoxysilane (C ₈ H ₁₇ Si (OC 2 H ₅ ) ₃ , Momentive Performance Materials A-137), 0.07 part of ion-exchanged water, 0 .1 Normal-0.6 parts by mass of hydrochloric acid aqueous solution was mixed and stirred at room temperature for 24 hours to prepare a long-chain alkyl group-containing alkoxysilane-based water repellent solution.

  A phosphor dispersion liquid was prepared by mixing 500 parts by mass of isopropanol and 11 parts by mass of sample particles B11.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 220 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopic analysis, it was confirmed that the elements were distributed in the order of carbon, silicon, and aluminum from the surface side in the coated phosphor particle coating.

[Example 12]
Long chain alkyl group-containing zirconium alkoxide is prepared by mixing 477 parts by weight of butanol and 6.6 parts by weight of n-octylzirconium trinormal butoxide (C ₈ H ₁₇ Zr (OC ₂ H ₅ ) ₃ ) and stirring at room temperature for 24 hours. A water repellent solution of the system was prepared.

  A phosphor dispersion was prepared by mixing 500 parts by weight of butanol and 11 parts by weight of sample particles B11.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 230 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopy, it was confirmed that the elements were distributed in the order of carbon, zirconia, silicon, and aluminum from the surface side in the coated phosphor particle coating.

[Example 13]
A long-chain alkyl group-containing titanium alkoxide is prepared by mixing 477 parts by weight of butanol and 5.8 parts by weight of n-octyltitanium trinormal butoxide (C ₈ H ₁₇ Ti (OC ₂ H ₅ ) ₃ ) and stirring at room temperature for 24 hours. A water repellent solution of the system was prepared.

  A phosphor dispersion was prepared by mixing 500 parts by weight of butanol and 11 parts by weight of sample particles B11.

  While stirring the phosphor dispersion, the water repellent solution was added to the phosphor dispersion over 1 hour, followed by stirring at room temperature for 5 hours, and then allowed to stand for a while. Subsequently, the supernatant was removed from this liquid, and the remaining liquid was filtered to separate the solid content. This solid content was washed with 200 parts by mass of isopropyl alcohol in a funnel. Subsequently, the solid content was dried under reduced pressure at 80 ° C. for 1 hour and then heat-treated at 300 ° C. for 1 hour to obtain particles of the coated phosphor.

  When the coated phosphor particles were cut by FIB processing and the cross section was observed with a transmission electron microscope (TEM), the surface of the phosphor particles was coated with a uniform film without cracks. The thickness was confirmed to be 230 nm.

  According to the depth direction analysis by X-ray photoelectron spectroscopy analysis, it was confirmed that the elements were distributed in the order of carbon, titanium, silicon, and aluminum from the surface side in the coated phosphor particle coating.

[Comparative Examples 1-3]
In Comparative Example 1, sample particle A was regarded as a coated phosphor particle, and in Comparative Example 2, sample particle C was regarded as a coated phosphor particle.

[Production and Evaluation of Wavelength Conversion Member and Light-Emitting Device]
A composition is prepared by mixing 15 parts by mass of the coated phosphor particles obtained in each Example and Comparative Example and 85 parts by mass of a silicone resin having a refractive index of 1.4, and pressing the composition. Thus, a dome-shaped wavelength conversion member having a thickness of 2 mm was produced.

  Using this wavelength conversion member, a light-emitting device having the structure shown in FIGS. A blue LED chip having an emission peak wavelength of 460 nm was used as the LED chip.

  This light-emitting device was intermittently energized for 1000 hours (30-minute lighting, 30-minute light-off cycle) in an atmosphere at a temperature of 85 ° C. and a relative humidity of 85% RH. The total luminous flux (initial value) of light emitted from the light emitting device immediately after energization and the total luminous flux of light emitted from the light emitting device at the time of intermittent energization for 1000 hours were measured. The results are shown in Table 1 below. The value of the total luminous flux shown in Table 1 is a percentage of the value of the total luminous flux at the time of intermittent energization for 1000 hours with respect to the initial value of the total luminous flux. It can be evaluated that the higher the total luminous flux maintenance factor, the better the moisture resistance of the coated phosphor.

表１中のＴＥＯＳはテトラエトキシシランを、ＡＩＰはアルミニウムイソプロポキシドを、ＴＳＬ８２３３はヘプタデカフルオロデシルトリメトキシシランを、ＨＭＤＳ３はヘキサメチレンジシラザンを、ＺＡ６５はジルコニウムテトラノルマルブトキシドを、ＴＡ２５はチタンテトラノルマルブトキシドを、Ａ１３７はｎ−オクチルトリエトキシシランを、それぞれ示す。

In Table 1, TEOS is tetraethoxysilane, AIP is aluminum isopropoxide, TSL8233 is heptadecafluorodecyltrimethoxysilane, HMDS3 is hexamethylenedisilazane, ZA65 is zirconium tetranormal butoxide, and TA25 is titanium tetratetrasilane. Normal butoxide and A137 represents n-octyltriethoxysilane, respectively.

DESCRIPTION OF SYMBOLS 100 Coated fluorescent substance 101 Phosphor particle 102 1st layer 103 2nd layer 104 3rd layer 105 4th layer 1 Light-emitting device 70 Wavelength conversion member

Claims (8)

A phosphor layer, a first layer covering the outside of the phosphor particle, and a second layer covering the outside of the first layer;
A coated phosphor in which the first layer is formed of a metal oxide and the second layer has a hydrophobic substituent. The coating according to claim 1, wherein the first layer is formed from a condensate of at least one compound selected from a metal alkoxide represented by the following chemical formula (1) and a partial hydrolysis condensate thereof. Phosphor.
M ¹ (OR ¹ ) _m (1)
M ¹ is a metal element.
R ¹ is selected from an alkyl group and hydrogen, and when a plurality of R ¹ are present in one molecule, they may be the same as or different from each other.
m number is equal to the valence of the metal element M ^1. The second layer is formed from a condensate of at least one compound selected from a metal alkoxide and a partial hydrolysis condensate thereof,
The coated phosphor according to claim 1 or 2, wherein the metal alkoxide includes a metal alkoxide represented by the following chemical formula (2).
M ² (R ² ) _nx (R ² ′) _x (2)
M ² is a metal element selected from Si, Ti, Al, Zr, Ge, and Y.
R ² is a functional group selected from an alkoxide group, a hydroxyl group, and a chloro group, and when a plurality of R ² are present in one molecule, they may be the same as or different from each other.
R ² ′ is a substituent selected from — (CH ₂ ) _y —CH ₃ and — (CH ₂ ) ₂ — (CF ₂ ) _z —CF ₃ , and when there are a plurality of R ² ′ in one molecule They may be the same or different.
n number is equal to the valence of the metal element M ^2.
x is an integer of 1 or more and satisfies the relationship of n> x.
y is an integer of 2 or more.
z is an integer of 1 or more. The coated phosphor according to claim 1 or 2, wherein the second layer is formed from an alkyl group introduced onto the surface of the first layer by a silazane compound represented by the following chemical formula (3). .
_{^{(R 3) 3 -Si-NH}} -Si (R 3) 3 ... (3)
R ³ is an alkyl group, and a plurality of R ³ present in one molecule may be the same as or different from each other.   The coated phosphor according to any one of claims 1 to 4, wherein the phosphor particles are formed of an alkaline earth silicate phosphor. The first layer is composed of a plurality of layers including at least a third layer disposed on the innermost side and a fourth layer laminated on the third layer,
The third layer is formed from a condensate of at least one compound selected from a metal alkoxide represented by the following chemical formula (1-1) and a partial hydrolysis condensate thereof,
6. The method according to claim 1, wherein the fourth layer is formed from a condensate of at least one compound selected from a metal alkoxide represented by the following chemical formula (1-2) and a partial hydrolysis condensate thereof. The coated phosphor according to claim 1.
Al (OR ¹ ) ₃ (1-1)
R ¹ is selected from an alkyl group and hydrogen, and when a plurality of R ¹ are present in one molecule, they may be the same as or different from each other.
M ¹ (OR ¹ ) _m (1-2)
M ¹ is a metal element selected from Si, Ti, Zr, Ge, and Y.
R ¹ is selected from an alkyl group and hydrogen, and when a plurality of R ¹ are present in one molecule, they may be the same as or different from each other.
m number is equal to the valence of the metal element M ^1.   The coated phosphor according to any one of claims 1 to 6, wherein the total thickness of the first layer and the second layer is in the range of 10 to 1000 nm.   A light-emitting device provided with the covering fluorescent substance as described in any one of Claims 1 thru | or 7.

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