JP5626788B2 - Sealant paint and use thereof - Google Patents

Description

  The present invention relates to a coating material for a sealing material of a light emitting diode and a light emitting diode using the coating material.

  2. Description of the Related Art Conventionally, in a light emitting diode (LED), a semiconductor element is sealed with a transparent sealing material such as an epoxy resin or a silicone resin in order to protect the semiconductor element. However, there is a problem that energy emitted from the LED increases as the wavelength of the LED becomes shorter and the luminance increases, and in some cases, heat is stored and the sealing resin is yellowed to lower the luminance of the LED.

Moreover, since the refractive index of the sealing material is low, there is a problem that light emitted from the LED is reflected by the sealing material and the light transmittance is lowered, and energy efficiency is lowered.
For this reason, a composition in which silicone resin is blended with surface-modified zirconia particles having a particle diameter of 1 to 20 nm is proposed as a sealing material that has excellent thermal stability, improved refractive index, and improved light transmittance. Has been. (Unexamined-Japanese-Patent No. 2009-173757, patent document 1)

JP 2009-173757 A

  However, as disclosed in Patent Document 1, in order to improve the dispersibility of zirconia particles in a silicone resin, primary surface modification and secondary surface modification are performed, and in order to eliminate residual OH groups, an alkylsilazane surface treatment agent is used. Since tertiary surface modification is required, in addition to low productivity, a large amount of surface modification agent is required, and these surface treatment agents have a refractive index of around 1.4. Is 1.6 or less, and the refractive index of the cured resin (encapsulant) using the same is not necessarily high, and thus there is a limit to the improvement of the light transmittance. In addition to the large number of surface treatment agents used, it is expensive, which is disadvantageous in terms of economy.

  As a result of intensive investigations in view of such problems, the present inventors have used any of the above-mentioned problems by using a coating material for sealing material containing hydrophobically treated zirconium oxide particles and hollow silica particles. I found that it can be resolved.

  And, using such a paint containing particles having different refractive indexes, if sealing layers made of sealing materials having different refractive indexes are laminated in order of higher refractive index, the sealing performance is excellent and light transmission is achieved. The inventors have found that a sealing layer having an improved rate can be formed and have completed the present invention. The configuration of the present invention is as follows.

[1] Hydrophobic zirconium oxide particles having an average particle diameter of 5 to 50 nm and / or hydrophobic silica-based hollow particles having an average particle diameter of 5 to 200 nm and a matrix resin component, A coating material for encapsulant having a content of 10 to 90% by weight.
[2] The hydrophobic particles contain a trialkylsilyl group on the surface, and the trialkylsilyl group as a solid content (R ₃ —SiO _1/2 ) with respect to the zirconium oxide particles and the silica-based hollow particles, [1] The sealing material coating material according to [1], which is contained in the range of 10 to 100% by weight.
[3] The encapsulant coating material according to [2], wherein the hydrophobic particles have a silica coating layer on the surface, and a trialkylsilyl group on the surface of the silica coating layer.
[4] The encapsulant coating material according to [1] to [3], wherein the matrix resin component is an epoxy resin or a silicone resin.
[5] A light-emitting diode sealing material provided with a sealing layer made of the paint.
[6] 2 to 20 sealing layers having different refractive indexes are laminated, and the refractive index n ₁ of the lowermost sealing layer (first sealing layer) is in the range of 1.55 to 1.85. There, sealing the top layer of the sealing layer (n-th sealing layer, n = 2 to 20) the refractive index n _n of the range of 1.30 to 1.65, at least two or more layers of different refractive indices A light-emitting diode encapsulating material, wherein a stop layer is laminated in order of high refractive index, and each encapsulating layer contains hydrophobic zirconium particles and / or hydrophobic silica-based hollow particles and a matrix resin.

  ADVANTAGE OF THE INVENTION According to this invention, the coating material for sealing materials which can form a light emitting diode sealing layer is provided. The refractive index of the sealing layer can be easily adjusted by changing the composition of the paint. Further, by laminating at least two kinds of sealing layers having different refractive indexes in the order of increasing refractive index, the sealing performance is excellent, reflection is suppressed, light transmittance (luminous efficiency) is high, and light energy is high. Since it does not remain in the device as thermal energy, a light-emitting diode (LED) with less heat storage and excellent luminance can be provided.

The schematic diagram of the light emitting diode in which the coating material concerning this invention is used is shown.

First, the encapsulant coating material according to the present invention will be described.
[Encapsulant paint]
The paint according to the present invention includes a particle component and a resin component.
The particle component is composed of hydrophobic zirconium oxide particles and / or hydrophobic silica-based hollow particles.

Hydrophobic zirconium oxide particles The average particle diameter of the hydrophobic zirconium oxide particles used in the present invention is preferably in the range of 5 to 50 nm, more preferably 8 to 30 nm.

  Hydrophobic zirconium oxide particles having a small average particle diameter are difficult to obtain as hydrophobic zirconium oxide particles having excellent hydrophobicity and dispersibility. If the average particle diameter of the hydrophobic zirconium oxide particles is too large, In some cases, the resulting sealing material has insufficient transparency and insufficient light transmittance.

  In the present invention, the average particle diameter of the hydrophobic zirconium oxide particles and the hydrophobic silica-based hollow particles described later is obtained by taking a transmission electron micrograph (TEM), measuring the particle diameters of 50 particles, and averaging the average particle diameters. Can be obtained.

  The refractive index of the hydrophobic zirconium oxide particles is preferably in the range of 1.58 to 2.0, more preferably 1.65 to 2.0. The refractive index in this range can be adjusted by the formation of a silica coating layer, the formation of a trialkylsilyl group, and the amount of these formations. The refractive index of zirconium oxide is in the range of 2.0 to 2.2.

If the zirconium oxide particles are replaced with titanium oxide particles having a higher refractive index instead of the hydrophobic zirconium oxide particles of the present invention, there remains a problem in light resistance.
The refractive index of the hydrophobic zirconium oxide particles used in the present invention was measured by the following method using Series A and AA manufactured by CARGILL as the standard refractive liquid.
(1) Take the hydrophobic zirconium oxide particle dispersion in an evaporator and evaporate the dispersion medium.
(2) This is dried at 80 ° C. for 12 hours to obtain a powder.
(3) A standard refraction liquid having a known refractive index is dropped on a glass plate of a few drops, and the above powder is mixed therewith.
(4) The operation of (3) is performed with various standard refractive liquids, and the refractive index of the standard refractive liquid when the mixed liquid becomes transparent is set as the refractive index of the hydrophobic zirconium oxide particles.

In addition, the measuring method of a refractive index is the same also about the hydrophobic silica type | system | group hollow particle mentioned later.
The hydrophobic zirconium oxide particles of the present invention preferably have a silica coating layer formed on the surface of the zirconium oxide particles as necessary.

The weight ratio of the silica coating layer varies depending on the particle diameter of the zirconium oxide particles, but is preferably in the range of 1 to 50% by weight, more preferably 3 to 40% by weight of the zirconium oxide particles as a solid content (SiO ₂ ).

  Within this range, the trimethylsilyl group can be sufficiently introduced to the surface of the zirconium oxide particles, and the refractive index does not become too low. If the weight ratio of the silica coating layer is changed within this range, for example, if the weight ratio is reduced, the amount of trimethylsilyl groups bonded to the surface of the zirconium oxide particles is reduced, but the resulting hydrophobic zirconium oxide particles have a high refractive index. Thus, the light transmittance of the sealing material can be increased, and the light emission efficiency (luminance) of the LED can be increased. Further, if the weight ratio is increased within the above range, the refractive index is decreased, but the amount of trimethylsilyl groups can be increased, so that the hydrophobicity is high and the dispersibility in the resin can be increased.

  In addition, when the silica coating layer is not formed, the bonding of the trimethylsilyl group may be insufficient. As a result, the LED scatters light, and the transmittance decreases or the haze increases. (Brightness) may be insufficient.

When the weight ratio of the silica coating layer is excessively introduced to the surface, the silica coating layer is formed by treatment with tetraalkoxysilane as described later.
A trialkylsilyl group is bonded to the surface of the hydrophobic zirconium oxide particles.

Examples of the trialkylsilyl group include a trimethylsilyl group and an n -octyldimethylsilyl group . The trialkylsilyl group may be directly introduced into the zirconium oxide particles and the silica particles. Further, when such a trialkylsilyl group is present on the surface of the silica coating layer, hydrophobic zirconium oxide fine particles having high hydrophobicity and high refractive index excellent in dispersibility in the resin can be obtained. It is preferable that the organic resin has dispersion medium compatibility.

As a result, it is possible to obtain a cured resin film (light emitting diode (LED)) having excellent dispersibility in epoxy resin and silicone resin, high light transmittance, and excellent heat resistance.
The weight ratio of the trialkylsilyl group varies depending on the type of the alkyl group, but is in the range of 10 to 100% by weight, more preferably 20 to 80% by weight of the zirconium oxide particles as the solid content (R ₃ —SiO _1/2 ). It is preferable that it exists in.

  By including a trialkylsilyl group in the above range, the refractive index is also in a predetermined range and has sufficient hydrophobicity, so when mixed with an LED sealing resin, the dispersibility and stability of the particles are high, sealing Since the haze of the material is low, the light transmittance is high. Within this range, the refractive index can be increased by reducing the number of trialkylsilyl groups, and the dispersibility and stability of the hydrophobic zirconium oxide particles can be increased by increasing the amount of trialkylsilyl groups. Note that if the amount of the silica coating layer or trialkylsilyl group is excessively increased, the refractive index is lowered. In some cases, when used as an LED sealing material, the emitted light does not come out and is scattered inside. However, since heat generation occurs, the light emission efficiency (luminance) may be reduced.

The surface charge amount of the hydrophobic zirconium oxide particles is preferably in the range of 3 to 30 μeq / g, more preferably 5 to 28 μeq / g.
If the surface charge amount of the hydrophobic zirconium oxide particles is low, the hydrophobicity of the hydrophobic zirconium oxide particles is too high. Therefore, when the sealing material is formed, the bond with the resin is deteriorated and the hardness of the sealing material is reduced. There is a case.

  If the surface charge amount of the hydrophobic zirconium oxide particles is high, the dispersibility and stability of the hydrophobic zirconium oxide particles become insufficient, and when mixed with a resin, they aggregate or increase the haze of the formed sealing material, The light transmittance may be insufficient.

The surface charge amount of the hydrophobic zirconium oxide particles can be adjusted by the weight ratio of the trialkylsilyl group and the type of the alkyl group.
Specifically, when the weight ratio of the trialkylsilyl group is large, the surface charge amount decreases, and when the content of the alkyl group having a large number of carbon atoms is large, the surface charge amount decreases.

  In the present invention, the surface charge amount is measured by using a surface potential titration apparatus (Mutek Co., Ltd .: pcd-03) and titrating the particle dispersion using 0.001 N poly-diallyldimethylammonium chloride. And obtained as a surface charge amount (μeq / g) per particle unit weight.

[Method for producing hydrophobic zirconium oxide particles]
The hydrophobic zirconium oxide particles used in the present invention can be prepared by the following steps (a) to (f).
(A) Step of preparing a zirconium oxide particle dispersion having an average particle size in the range of 5 to 50 nm (b) Step of adding an organosilicon compound (1) represented by the following formula (1) SiX ₄ (1)
(Where X is an alkoxy group having 1 to 4 carbon atoms)
(C) Step of hydrolyzing organosilicon compound (1) (d) Step of solvent substitution with organic solvent (e) Step of adding organosilicon compound (2) having trialkylsilyl group (f) Trialkylsilylation Process

Step (a)
A zirconium oxide particle dispersion having an average particle size in the range of 5 to 50 nm is prepared.
The average particle diameter of the zirconium oxide particles used in the present invention is preferably in the range of 5 to 50 nm, more preferably 8 to 30 nm.

  If the zirconium oxide particles are too small, as described above, in addition to low crystallinity and low refractive index, they may aggregate when forming the silica coating layer for obtaining the hydrophobic zirconium oxide particles of the present invention. For this reason, trialkylsilylation becomes nonuniform, and hydrophobicity and dispersibility may be insufficient. If the zirconium oxide particles are too large, the reason is not clear. However, the transparency of the cured resin film (encapsulant) obtained from the zirconium oxide particles may be insufficient and the light transmittance may be insufficient. is there.

As the dispersion medium used for the dispersion, water, alcohol such as methanol, ethanol, propanol, butanol, and other organic solvents are preferably used.
The concentration of the zirconium oxide particle dispersion is preferably from 0.5 to 30% by weight, more preferably from 5 to 20% by weight as the solid content. If the concentration is too low, the productivity in the step (b) decreases. Even if the concentration is too high, the zirconium oxide particles may agglomerate in step (c). For this reason, trimethylsilylation becomes non-uniform in step (f), and the hydrophobic and dispersibility of the resulting hydrophobic zirconium oxide particles is poor. In some cases, the transparency, strength, and the like of the sealing material become insufficient.

Step (b)
An organosilicon compound (1) represented by the following formula (1) is added. Thereby, a silica coating layer is formed. If a trialkylsilyl group can be directly introduced, steps (b) and (c) are not necessarily performed.

SiX ₄ (1)
(Where X is an alkoxy group having 1 to 4 carbon atoms))
Specific examples of such an organosilicon compound (1) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

The amount of the organosilicon compound (1) added varies depending on the particle diameter of the zirconium oxide particles used, but is preferably in the range of 1 to 50% by weight, more preferably 3 to 40% by weight of the zirconium oxide particles as SiO _2. .

  Within this range, as described above, the trimethylsilyl group can be sufficiently introduced to the surface of the zirconium oxide particles, and the refractive index does not become too low. If the addition amount of the organosilicon compound (1) is changed within this range, for example, if it is eliminated, the amount of trimethylsilyl groups bonded to the surface of the zirconium oxide particles will be reduced, but the resulting hydrophobic zirconium oxide particles have a high refractive index. Thus, the light transmittance of the sealing material can be increased, and the light emission efficiency (luminance) of the LED can be increased. Further, if the amount is increased in the above range, the refractive index is lowered, but the amount of trimethylsilyl groups bonded can be increased, so that the hydrophobicity is high and the dispersibility in the resin can be improved.

In this step, the organosilicon compound (3) represented by the following formula (3) can be mixed and used together with the organosilicon compound (1).
R ₁ -SiX ₃ (3)
(In the formula, R is an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, and may be the same or different from each other. X: an alkoxy group having 1 to 4 carbon atoms, a hydroxyl group, Halogen, hydrogen)

  Examples of the organosilicon compound (3) include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane. Methoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (βmethoxyethoxy) silane, 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxymethyltrimethoxysilane, γ-glycidoxymethyltriethoxysilane, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxyethyltri Ethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, γ- (β-glycid Xyethoxy) propyltrimethoxysilane, γ- (meth) acrylooxymethyltrimethoxysilane, γ- (meth) acrylooxymethyltriethoxysilane, γ- (meth) acrylooxyethyltrimethoxysilane, γ- ( (Meth) acryloxyethyltriethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ -(Meth) acryloxypropyltriethoxysilane, and mixtures thereof Things.

By using such an organosilicon compound (3), a hydrophobic zirconium oxide excellent in hydrophobicity and dispersibility can be obtained. The amount of the organosilicon compound (3) used is desirably in the range of 1 to 50% by weight, preferably 3 to 40% by weight, based on ZrO _{2 of the} zirconium oxide particles.

Step (c)
Next, water and a catalyst for hydrolysis are added, and the organosilicon compound (1) is hydrolyzed to form a silica coating layer on the surface of the zirconium oxide particles.

At this time, the molar ratio (M _H2O ) / (M _OC ) between the number of moles of water to be added (M _H2O ) and the number of moles (M _OC ) of the organosilicon compound (1) is 1 to 300, more preferably 5 to 200. It is preferable that it exists in the range.

When the molar ratio (M _H2O ) / (M _OC ) is low, hydrolysis is insufficient, and as in the case where the organosilicon compound (1) is low, the bonding of trimethylsilyl groups to the surface of the zirconium oxide particles is insufficient. In some cases, hydrophobic zirconium oxide particles having sufficient hydrophobicity cannot be obtained.

If the molar ratio (M _H2O ) / (M _OC ) is too high, it may need to be removed later, but it may be difficult to remove, resulting in insufficient dispersibility in the resin, aggregation of the particles, and haze. May be higher. Further, the obtained sealing material may be insufficiently cured or voids may be generated.

  Further, ammonia is preferable as the hydrolysis catalyst. When ammonia is used, it is easy to remove even if it remains in the paint, and if the residual amount is small, the dispersibility of the hydrophobic zirconium oxide particles in the paint will not be greatly impaired, and it is formed using the paint. The performance of the sealing material is not impaired.

The molar ratio (M _NH3 ) / (M _OC ) of the number of moles of ammonia to be added (M _NH3 ) and the number of moles (M _OC ) of the organosilicon compound (1) is 0.1 to 12, more preferably 0.2 to A range of 10 is preferable.

When the molar ratio (M _NH3 ) / (M _OC ) is low, hydrolysis becomes insufficient, and there are the same problems as in the case where the amount of water is small. If the molar ratio (M _NH3 ) / (M _OC ) is too high, no unhydrolyzed product will remain, but a large amount of ammonia will remain, and the dispersibility of the hydrophobic zirconium oxide particles in the paint will be In some cases, the resulting resin cured product film (encapsulant) may be poorly cured and voids may be generated. For this reason, it is necessary to remove the remaining ammonia.
Water and ammonia can be added individually, but it is preferably added as ammonia water.

Step (d)
The solvent is replaced with an organic solvent.
Organic solvents include alcohols such as methanol, ethanol, propanol, 2-propanol (IPA), butanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol isopropyl ether, propylene glycol monomethyl ether And ethers such as propylene glycol monoethyl ether; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

  Of these, the use of alcohols such as methanol, ethanol, 2-propanol (IPA) is preferable because the silica-coated zirconia sol obtained in the step (c) hardly stabilizes and is stable.

As a replacement method, a conventionally known method such as a distillation method, an ultrafiltration membrane method, or a rotary evaporator method can be employed.
The concentration of the organic solvent dispersion after solvent replacement is preferably in the range of 0.5 to 40% by weight, more preferably 1.0 to 30% by weight as the solid content.

Step (e)
As a hydrophobizing agent, an organosilicon compound (2) having a trialkylsilyl group is added. Hexamethyldisilazane as the organic silicon compound (2) having a trialkylsilyl group, trimethyl silanol, preparative trimethyl methoxy silane, trimethyl chloro silane, n- octyl dimethyl chlorosilane, and the like and mixtures thereof.

The addition amount of the organosilicon compound (2) having a trialkylsilyl group varies depending on the particle diameter of the zirconium oxide particle and the type (size) of the alkyl group, but is added within a range that can be closely bonded to the surface of the zirconium oxide particle. However, it is preferable to add (R ₃ —SiO _1/2 ) so that it is 10 to 100% by weight, more preferably 20 to 80% by weight of the zirconium oxide particles.

  If the addition amount of the organosilicon compound (2) having a trialkylsilyl group is small, dispersibility, particularly dispersibility in hydrophobic resins such as epoxy resins and silicone resins, becomes insufficient. The transmittance may be insufficient. Even if the amount of the organosilicon compound (2) having a trialkylsilyl group is too large, the dispersibility is not further improved, the refractive index is lowered, and the light transmittance may be insufficient.

Step (f)
Subsequently, the organosilicon compound (2) is reacted to be trialkylsilylated by heat treatment.

  Usually, the heat treatment is preferably carried out under stirring, and the temperature at this time varies depending on the type of the solvent, but is preferably not more than the boiling point of the solvent, and is generally in the range of 30 to 90 ° C. As another method, a method of heating to reflux can also be employed.

  Although heating temperature changes also with the kind of organic solvent and the kind of organic silicon compound (2), it is preferable that it exists in the range of 30-90 degreeC, Furthermore, 40-80 degreeC. At this time, although the heating time varies depending on the temperature and the reactivity of the organosilicon compound (2), it is approximately 1 to 24 hours.

  The thus obtained organic solvent dispersion of hydrophobic zirconium oxide particles can be used as it is, can be used after removing the organic solvent, and can also be used after being replaced with another dispersion medium. .

As a replacement method, a conventionally known method such as a distillation method, an ultrafiltration membrane method, or a rotary evaporator method can be employed.
Other known organic solvents can be used as other dispersion media, and alcohols such as methanol, ethanol, propanol, 2-propanol (IPA) and butanol; esters such as methyl acetate, ethyl acetate and butyl acetate Class: diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol isopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, etc. Ethers; acetone, methyl ethyl ketone, methyl isobutyl ketone, butyl methyl ketone, cyclohexanone, methyl Cyclohexanone, dipropyl ketone, methyl pentyl ketone, diisobutyl ketone, isophorone, acetylacetone, ketones such as acetoacetate; toluene, xylene and the like.

  Furthermore, a resin component such as an epoxy resin and a silicone resin, which will be described later, can be used as a dispersion medium as a solvent. When an epoxy resin, a silicone resin, or the like is used, the paint of the present invention is directly obtained by removing other organic solvents.

  Hydrophobic zirconium oxide particles obtained by the above production method have trialkylsilyl groups bonded to the surface, have an average particle diameter in the range of 5 to 50 nm, and a refractive index in the range of 1.58 to 2.0. Yes, the surface charge amount is in the range of 3 to 30 μeq / g, and the dispersibility in the resin is excellent.

[Hydrophobic silica-based hollow particles]
The average particle diameter of the hydrophobic silica-based hollow particles used in the present invention is preferably in the range of 2 to 200 nm, more preferably 10 to 150 nm. Hollow particles have cavities inside.

  If the hydrophobic silica-based hollow particles are too small, it is difficult to obtain hydrophobic silica-based hollow particles excellent in hydrophobicity and dispersibility. Even if the hydrophobic silica-based hollow particles are too large, the sealing material In some cases, the transparency is insufficient and the light transmittance is insufficient.

The thickness of the outer shell layer of the hollow particles varies depending on the particle diameter, but is usually in the range of 1 to 20 nm.
The refractive index of the hydrophobic silica-based hollow particles is preferably in the range of 1.15 to 1.45, more preferably 1.15 to 1.40. It is difficult to obtain a hydrophobic silica-based hollow particle having a refractive index lower than the above range. Usually, hydrophobic silica-based hollow particles are used to form a sealing layer having a low refractive index, but those having a high refractive index exceeding the above range cannot lower the refractive index of the uppermost sealing layer. In some cases, the light transmittance cannot be sufficiently increased. In the present invention, normal silica particles that are not hollow can be used for the sealing layer other than the uppermost layer.

  The hydrophobic silica-based hollow particles used in the present invention may have a silica coating layer formed on the surface of the silica-based hollow particles. In the case of silica hollow particles (as well as arbitrary silica), it is not always necessary to provide a silica coating layer like the above-mentioned zirconium oxide particles.

The weight ratio of the silica coating layer varies depending on the particle size of the silica-based hollow particles, but is preferably 50% by weight or less, more preferably 3 to 40% by weight of the silica-based hollow particles as a solid content (SiO ₂ ). .

  If there are too many silica coating layers, the refractive index of the resulting hydrophobic silica-based hollow particles increases, and the refractive index of the uppermost sealing layer cannot be lowered, and the light transmittance may not be sufficiently increased. .

A trialkylsilyl group is bonded to the surface of the hydrophobic silica-based hollow particles. Examples of the trialkylsilyl group include a trimethylsilyl group and an n -octyldimethylsilyl group .

  When the trialkylsilyl group is bonded, a light emitting diode (LED) having excellent dispersibility in resins, particularly epoxy resins and silicone resins, high light transmittance, and excellent heat resistance can be obtained.

Although the weight ratio of the trialkylsilyl group varies depending on the type of the alkyl group, it is 10 to 100% by weight, more preferably 20 to 80% by weight of the silica-based hollow particles as a solid content (R ₃ —SiO _1/2 ). It is preferable to be in the range.

  By including a trialkylsilyl group in the above range, the refractive index is also in a predetermined range and has sufficient hydrophobicity, so when mixed with an LED sealing resin, the dispersibility and stability of the particles are high, sealing Since the haze of the material is low, the light transmittance can be increased. In this range, if the number of trialkylsilyl groups is decreased, the refractive index can be increased, and if the amount of trialkylsilyl groups is increased, the dispersibility and stability of the hydrophobic hollow silica particles can be increased. If the amount of the silica coating layer or trialkylsilyl group is too large, the refractive index may exceed 1.45, and the refractive index of the uppermost sealing layer cannot be lowered. It may not be possible to increase it.

The surface charge amount of the hydrophobic silica-based hollow particles is preferably in the range of 3 to 30 μeq / g, more preferably 5 to 28 μeq / g.
If the surface charge amount of the hydrophobic silica-based hollow particles is low, the hydrophobicity of the hydrophobic silica-based hollow particles is too high. Therefore, when the sealing material is formed, the bond with the resin is deteriorated, and the hardness of the sealing material is low. May decrease.

  Even if the surface charge amount of the hydrophobic silica-based hollow particles is too high, the dispersibility and stability of the hydrophobic silica-based hollow particles become insufficient, and when mixed with a resin, they aggregate or haze the formed sealing material. May increase and the light transmittance may be insufficient.

The surface charge amount of the hydrophobic silica-based hollow particles can be adjusted by the weight ratio of the trialkylsilyl group and the type of the alkyl group.
Specifically, when the weight ratio of the trialkylsilyl group is large, the surface charge amount decreases, and when the content of the alkyl group having a large number of carbon atoms is large, the surface charge amount decreases.

[Method for producing hydrophobic silica-based hollow particles]
The hydrophobic silica-based hollow particles used in the present invention can be prepared by the following steps (a) to (f) as in the method for producing the hydrophobic zirconium oxide particles.
(A) Step of preparing a silica-based hollow particle dispersion having an average particle size in the range of 5 to 200 nm (b) Step of adding an organosilicon compound (1) represented by the following formula (1) SiX ₄ (1 )
(Where X is an alkoxy group having 1 to 4 carbon atoms)
(C) Step of hydrolyzing organosilicon compound (1) (d) Step of solvent substitution with organic solvent (e) Step of adding organosilicon compound (2) having trialkylsilyl group (f) Trialkylsilylation Process

Step (a)
A silica-based hollow particle dispersion having an average particle size in the range of 5 to 200 nm is prepared.

  As silica-based hollow particles, silica-based particles having cavities therein disclosed in Japanese Patent Application Laid-Open Nos. 2001-167737 and 2001-233611 filed by the applicant of the present application are preferably used with a low refractive index. it can.

The average particle diameter of the silica-based hollow particles used in the present invention is preferably in the range of 5 to 200 nm, more preferably 10 to 150 nm.
If the average particle size of the silica-based hollow particles is small, the silica-coating layer may be aggregated when forming the hydrophobic silica-based hollow particles, resulting in non-uniform trialkylsilylation and hydrophobicity. , Dispersibility may be insufficient.

Even if the silica-based hollow particles are too large, the transparency of the sealing layer obtained using the resulting hydrophobic silica-based hollow particles may be insufficient, and the light transmittance may be insufficient.
As the dispersion medium used for the dispersion, water, alcohol such as methanol, ethanol, propanol, butanol, and other organic solvents are preferably used.

  The concentration of the silica-based hollow particle dispersion is preferably in the range of 0.5 to 30% by weight, more preferably 5 to 20% by weight as the solid content. If the concentration of the dispersion is too low, productivity in the step (b) is lowered. Even if the concentration of the dispersion is too high, the silica-based hollow particles may be aggregated in the step (c). Therefore, trimethylsilylation becomes non-uniform in the step (f), and the hydrophobic silica-based hollow particles thus obtained are hydrophobic. And dispersibility may deteriorate, and the transparency and strength of the sealing material may be insufficient.

Step (b)
An organosilicon compound (1) represented by the following formula (1) is added. Note that steps (b) and (c) are not necessarily performed.

SiX ₄ (1)
(Where X is an alkoxy group having 1 to 4 carbon atoms)
Such an organosilicon compound (1) is as described above.

The addition amount of the organosilicon compound (1) varies depending on the particle diameter of the silica-based hollow particles to be used, but it may be 50% by weight or less, more preferably 3 to 40% by weight of the silica-based hollow particles as SiO _2. preferable.

  When the amount of the organosilicon compound (1) is small, the bonding of the trimethylsilyl group to the silica-coated silica-based hollow particle surface becomes insufficient in the step (f) described later, and the hydrophobicity and dispersibility are excellent. Silica-based hollow particles may not be obtained, and even if such particles are mixed into a resin described later, the dispersibility is insufficient and the particles are aggregated. For this reason, the obtained LED is scattered in light, resulting in a decrease in transmittance and an increase in haze, resulting in insufficient luminous efficiency (luminance).

  Within this range, as described above, the trimethylsilyl group can be sufficiently introduced to the surface of the hollow silica particles, and the refractive index does not become too low. If the addition amount of the organosilicon compound (1) is changed within this range, for example, if the addition amount is increased within the above range, the refractive index decreases, but the amount of trimethylsilyl groups can be increased. Dispersibility can be increased.

In this step, the organosilicon compound (3) represented by the following formula (3) can be used in the same manner as described above by mixing with the organosilicon compound (1).
R ₁ -SiX ₃ (3)
(In the formula, R is an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, and may be the same or different from each other. X: an alkoxy group having 1 to 4 carbon atoms, a hydroxyl group, Halogen, hydrogen)
The organosilicon compound (3) is as described above. The amount of the organosilicon compound (3) used is desirably in the range of 1 to 50% by weight, preferably 3 to 40% by weight, based on SiO _{2 of the} hollow silica particles.

Step (c)
Next, water and a catalyst for hydrolysis are added to hydrolyze the organosilicon compound (1) to form a silica coating layer on the surface of the silica-based hollow particles.

At this time, the molar ratio (M _H2O ) / (M _OC ) between the number of moles of water to be added (M _H2O ) and the number of moles (M _OC ) of the organosilicon compound (1) is determined by the preparation of the hydrophobic zirconium oxide particles. Similarly, it is preferably in the range of 1 to 300, more preferably 5 to 200.

  Further, ammonia is preferable as the hydrolysis catalyst. When ammonia is used, it can be easily removed even if it remains in the paint, and if the residual amount is small, the dispersibility of the hydrophobic silica-based hollow particles in the paint will not be greatly impaired. The performance of the sealing material formed by use is not impaired.

The molar ratio (M _NH3 ) / (M _OC ) between the number of moles of ammonia to be added (M _NH3 ) and the number of moles (M _OC ) of the organosilicon compound (1) is 0.1 to 12, Furthermore, it is preferable that it exists in the range of 0.2-10.
In addition, when manufacturing a hydrophobic silica type hollow particle, it is not necessary to form a silica coating layer.

Step (d)
The solvent is replaced with an organic solvent. In addition, when a process (b) and (c) are abbreviate | omitted, the organic-solvent dispersion liquid of a silica type hollow particle is prepared.

  Organic solvents include alcohols such as methanol, ethanol, propanol, 2-propanol (IPA), butanol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol isopropyl ether, propylene glycol monomethyl ether And ethers such as propylene glycol monoethyl ether; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

Of these, the use of alcohols such as methanol, ethanol, 2-propanol (IPA) is preferable because the silica-coated silica-based hollow particles are less likely to aggregate and are stable.
As a replacement method, a conventionally known method such as a distillation method, an ultrafiltration membrane method, or a rotary evaporator method can be employed.
The concentration of the organic solvent dispersion after solvent replacement is preferably in the range of 0.5 to 40% by weight, more preferably 1.0 to 30% by weight as the solid content.

Step (e)
As a hydrophobizing agent, an organosilicon compound (2) having a trialkylsilyl group is added.
The organosilicon compound (2) having a trialkylsilyl group is as described above.
The addition amount of the organosilicon compound (2) having a trialkylsilyl group varies depending on the particle size of the silica-based hollow particle and the type (size) of the alkyl group, but can be closely bonded to the surface of the silica-based hollow particle. However, it is preferable to add such that (R ₃ —SiO _1/2 ) is 10 to 100% by weight, more preferably 20 to 80% by weight of the silica-based hollow particles.

  When there are few organosilicon compounds (2) which have a trialkylsilyl group, dispersibility, especially dispersibility to hydrophobic resins, such as an epoxy resin and a silicone resin, becomes inadequate, and LED using this has light transmittance. May be insufficient. If the organosilicon compound (2) having a trialkylsilyl group is too much, the dispersibility is not further improved, the refractive index is increased, and the light transmittance may be insufficient in the present invention.

Step (f)
Next, after the step (e), the organosilicon compound (2) is reacted by heat treatment to be trialkylsilylated. The heat treatment is preferably performed under stirring, and the temperature at this time varies depending on the type of solvent, but is preferably not more than the boiling point of the solvent, and is generally in the range of 30 to 90 ° C. As another method, a method of heating to reflux can also be employed.

  Although heating temperature changes also with the kind of organic solvent and the kind of organic silicon compound (2), it is preferable that it exists in the range of 30-90 degreeC, Furthermore, 40-80 degreeC. At this time, although the heating time varies depending on the temperature and the reactivity of the organosilicon compound (2), it is approximately 1 to 24 hours.

  The organic solvent dispersion of the hydrophobic silica-based hollow particles obtained in this way can be used as it is, can be used after removing the organic solvent, and can also be used after being replaced with another dispersion medium. it can.

As a replacement method, a conventionally known method such as a distillation method, an ultrafiltration membrane method, or a rotary evaporator method can be employed.
As the other dispersion medium, a conventionally known organic solvent can be used, and examples thereof include those similar to those exemplified for the hydrophobic zirconium oxide particles.

  Furthermore, resin components such as an epoxy resin and a silicone resin, which will be described later, can be exemplified as other dispersion media. When an epoxy resin, a silicone resin, or the like is used, the paint of the present invention is directly obtained by removing other organic solvents.

  Hydrophobic silica-based hollow particles obtained by the above production method have trialkylsilyl groups bonded to the surface, have an average particle diameter in the range of 5 to 30 nm, and a refractive index in the range of 1.15 to 1.45. The surface charge amount is in the range of 3 to 30 μeq / g, and the resin has excellent dispersibility.

Resin component As the resin component used in the present invention, an epoxy resin or a silicone resin is preferably used.

  Examples of the epoxy resin include resins marketed as bisphenol A, phenol novolac, cresol novolak, and the like, and mixtures thereof. Examples of the silicone resin include dimethyl silicone resin, phenyl silicone resin, methylphenylsilcon resin, and mixtures thereof.

The concentration of the hydrophobic zirconium oxide particles and / or the hydrophobic silica-based hollow particles in the coating composition (the total amount when both are included) is in the range of 10 to 90% by weight, further 20 to 85% by weight as the solid content. It is preferable that it exists in. Further, the ratio of the hydrophobic zirconium oxide particles and the hydrophobic silica-based hollow particles may be adjusted according to the refractive index of the desired sealing material, and further, the hydrophobic silica particles (like the hollow silica particles, the silica particles May be included). A paint containing only hydrophobic zirconium oxide particles is used for the lowermost layer of the light-emitting diode sealing layer, and a paint containing only hydrophobic hollow silica particles is used for the uppermost layer.

  When the particle component in the paint is small, the refractive index of the resin used becomes dominant, and the refractive index of each sealing layer is adjusted to a desired refractive index, or a sealing layer having the desired refractive index difference is obtained. It may not be possible. Even if there are too many particle components in the paint, the refractive index of the sealing layer can be adjusted, but the particles will aggregate, in this case causing light scattering of the sealing layer, reducing the light transmittance, In addition to an increase in haze and a decrease in luminous efficiency (brightness), sealing performance may be insufficient due to a small amount of resin.

  Such a paint comprises (1) the hydrophobic zirconium oxide particles and the organic particles of the hydrophobic silica-based hollow particles obtained in step (f) of the method for producing the hydrophobic silica-based hollow particles. A method in which a predetermined amount of a resin component is added to a solvent dispersion, followed by heating within a range where the resin does not cure, and heating under reduced pressure as necessary to remove the organic solvent; (2) the hydrophobic zirconium oxide After evaporating the organic solvent from the organic solvent dispersion of the hydrophobic zirconium oxide particles and / or the hydrophobic silica-based hollow particles obtained in the step (f) of the method for producing the particles and the hydrophobic silica-based hollow particles, There is a method of mixing a predetermined amount with a resin component, etc., and it can be prepared by a method using these together if necessary.

The paint may contain an organic solvent, if necessary, but the concentration is usually 3% by weight or less, more preferably 1% by weight or less, and particularly preferably substantially free of solvent.
If a high concentration of organic solvent remains in the paint, a solvent removal step is required when forming the sealing layer. If the organic solvent remains, it may cause voids or poor curing. It may become.

Such a paint may contain a curing agent, a polymerization initiator, and the like as necessary.
Next, a light emitting diode (LED) according to the present invention will be described.

[Light Emitting Diode (LED)]
The light emitting diode according to the present invention has a sealing layer made of the paint.
First, one mode of a light emitting diode using the light emitting diode according to the present invention is shown in FIG. In FIG. 1, a sealing layer made of a sealing material using the paint of the present invention is laminated between a light emitting diode and a lens (not shown). The uppermost layer may be flat or convex.

In the present invention, the number of sealing layers provided may be two or more, preferably 2 to 20 layers, more preferably 4 to 20 layers.
When the sealing layer is a single layer, the effect of improving the light transmittance by suppressing reflection is not obtained, and if the number of sealing layers is too large, the effect of improving the light transmittance is not further improved, The decline in economic efficiency will increase.

In the light emitting diode according to the present invention, the refractive index n ₁ of the first sealing layer is in the range of 1.55 to 1.85, and the nth sealing layer (nth sealing layer, n = 2 to 20). refractive index n _n is in the range of 1.30 to 1.65, it is characterized in that sealing layer at least two or more layers of different refractive indices is formed by laminating a high refractive index order.

The refractive index n ₁ of the first sealing layer is preferably in the range of 1.55 to 1.85, more preferably 1.60 to 1.85.
If the refractive index n ₁ of the first sealing layer is too low, the degree of light reflection on the LED light emitting element side increases, and the transmittance may decrease. If the refractive index n ₁ of the first sealing layer is too high, sealing performance, light transmittance (light emission efficiency), and the like may be insufficient. Such a first sealing layer is usually formed containing hydrophobic zirconium oxide particles.

The n sealing layer (n-th sealing layer: top layer) refractive index n _n of 1.30 to 1.65, more preferably in the range of 1.35 to 1.55. If the refractive index n _n of the n sealing layer is low, may be lower than the refractive index of the lens, the lower refractive index than the lens, is reflected in the opposite direction, light transmittance is reduced, Thus May generate heat.

  The difference in refractive index between adjacent sealing layers is preferably in the range of 0.02 to 0.2, more preferably 0.05 to 0.15. And a sealing layer is laminated | stacked so that it may become such a refractive index, and the refractive index of the uppermost layer is finally made into the said range.

Since the reflection cannot be suppressed when the refractive index difference between adjacent sealing layers is less than 0.02, the light transmittance (light emission efficiency) or the like may be insufficient.
When the difference in refractive index between adjacent sealing layers exceeds 0.2, although depending on the film thickness, the number of sealing layers decreases, so that the light transmittance (light emission efficiency) and the like may be insufficient.

The thickness of the laminated sealing layer is preferably 0.1 to 5 mm, and more preferably 0.5 to 4 mm.
When the thickness of the laminated sealing layer is thin, it is difficult to obtain the effect as the sealing layer. On the other hand, since the thickness of the laminated sealing layer is too thick, the ratio of absorbing the light of the sealing layer itself increases, and the effect of forming the sealing layer in multiple layers may not be obtained.

  Each sealing layer is composed of the hydrophobic zirconium particles having an average particle diameter of 5 to 50 nm and / or the hydrophobic silica-based hollow particles having an average particle diameter of 5 to 200 nm and a resin.

  The content of the hydrophobic zirconium particles and / or the hydrophobic silica-based hollow particles in the sealing layer is preferably in the range of 10 to 90% by weight, more preferably 20 to 85% by weight as the solid content.

  When the content of the hydrophobic zirconium oxide particles and / or the hydrophobic silica-based hollow particles in the sealing layer is less than 10% by weight as the solid content, the refractive index of the resin used is dominant, and the refractive index of each sealing layer In some cases, it is impossible to adjust the refractive index to a desired refractive index or to obtain a sealing layer having the desired refractive index difference.

  When the content of hydrophobic zirconium oxide particles and / or hydrophobic silica-based hollow particles in the sealing layer exceeds 90% by weight as the solid content, the refractive index of the sealing layer can be adjusted, but the particles will aggregate. In that case, it causes light scattering of the LED, the light transmittance is reduced, the haze is increased, the luminous efficiency (luminance) is lowered, and the sealing performance is insufficient due to the small amount of resin. There is a case.

  Adjustment of the refractive index of the sealing layer takes into consideration the refractive index of the resin, (1) changing the blending amount of hydrophobic zirconium particles having a high refractive index and a resin having a low refractive index, or (2) having a high refractive index. This is done by changing the blending amount and blending ratio of the hydrophobic zirconium particles and the hydrophobic silica-based hollow particles having a low refractive index. In order to obtain a sealing layer having a high refractive index, a large amount of hydrophobic zirconium particles is blended, and in order to obtain a sealing layer having a low refractive index, the blending amount of hydrophobic silica-based hollow particles may be increased.

The light transmittance as the laminated sealing layer of the present invention varies depending on the thickness of the sealing layer (paint cured film), but is preferably 80% or more, and more preferably 90% or more.
Each sealing layer is formed by applying and curing the coating layer so as to have a predetermined thickness using the coating material adjusted to have a desired refractive index. The coating method is not particularly limited, and examples thereof include a potting method and a bar coater method. Although it does not restrict | limit especially as a hardening process, It is performed by irradiation of heating, an electron beam (ultraviolet ray), electromagnetic waves, etc. Such heat treatment is not particularly limited as long as the resin component is cured.

  Further, the curing method is not particularly limited, but after curing one sealing layer, the second and subsequent sealing layers may be cured and laminated, or an uncured sealing layer is laminated and formed. Then, you may perform a hardening process entirely.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited by these Examples.

[Production Example 1]
Preparation of hydrophobic zirconium oxide particles (1 ) 35 g of zirconium oxychloride octahydrate (ZrOCl ₂ .8H ₂ O (manufactured by Taiyo Mining Co., Ltd .: ZrO ₂ concentration 37.2% by weight)) was dissolved in 1,300 g of pure water. A zirconium hydroxide hydrogel (ZrO ₂ concentration 1% by weight) was prepared by adding 123 g of a 10% by weight aqueous KOH solution, and the conductivity was 0.5 mS / cm or less by the ultrafiltration membrane method. Washed until

400 g of a 10 wt% KOH aqueous solution was added to 2,000 g of 1 wt% zirconium hydroxide hydrogel as the obtained ZrO ₂ , and after sufficient stirring, 200 g of a 35 wt% hydrogen peroxide aqueous solution was added. At this time, the solution foamed vigorously and the solution became transparent, and the pH was 11.5.

This solution was filled in an autoclave, hydrothermally treated at 150 ° C. for 11 hours, and then separated by centrifugal sedimentation to recover a white precipitate.
After adding 281.6 g of pure water to 56.4 g of the recovered white precipitate, 6.9 g of tartaric acid (manufactured by Kanto Chemical Co., Ltd .: L-tartaric acid) and 22.0 g of a 10 wt% KOH aqueous solution are sufficiently added. Stir. After adding 1000 g of silica beads, it was filled in a dispersing machine (manufactured by Campe Co., Ltd .: BATCH-SAND) and dispersed to obtain a zirconia sol. Subsequently, after washing with pure water using an ultrafiltration membrane, 40 g of anion exchange resin (ROHM-AND HAAS: Duolite UP-5000) was added to perform deionization to obtain a solid content concentration of 1.5% by weight. A dispersion of zirconium oxide fine particles (1) was obtained. The average particle diameter of the obtained zirconium oxide particles (1) was 15 nm.

  The crystal form of the zirconium oxide particles (1) was monoclinic as measured by X-ray diffraction. Furthermore, the refractive index of the obtained zirconium oxide particles (1) was 2.2.

Formation of silica coating layer After heating a mixed dispersion of 1289 g of a dispersion of zirconium oxide particles (1) having a solid content concentration of 1.5% by weight, 1128 g of methanol and 20.7 g of an aqueous ammonia solution having a concentration of 28% by weight to 35 ° C. Then, a solution prepared by mixing 31.94 g of methanol and 6.71 g of tetraethoxysilane (manufactured by Tama Chemical Industry Co., Ltd .: ethyl silicate-A, SiO ₂ content 28.8 wt%) was added with a roller pump over 6 hours. Thereafter, the mixture was heated and stirred at 35 ° C. for 1 hour. Next, the solvent was replaced with methanol using an ultrafiltration membrane to prepare a silica-coated zirconium oxide particle (1) methanol dispersion having a solid content concentration of 5% by weight.

Silica-coated zirconium oxide particles with a solid content concentration of 5% by weight (1) 700 g of methanol dispersion and 700 g of methanol are placed in a trialkylsilylated separable flask and thoroughly stirred and mixed, and then a hydrophobizing agent (trialkylsilylating agent). 17.5 g of hexamethyldisilazane (HMDS) (manufactured by Wako Pure Chemical Industries, Ltd .: 1,1,1,1,3,3,3-hexamethyldisilazane) was added and the temperature was raised to 50 ° C. Thereafter, the mixture was heated and stirred for 22 hours to prepare a dispersion of trimethylsilylated zirconium oxide particles (1) having a solid content concentration of 2.5% by weight. The refractive index of the trimethylsilylated zirconium oxide particles (1) was 1.72.

Further, the surface charge amount of the trimethylsilylated zirconium oxide particles (1) was measured by the above-described measuring method and found to be 21 μeq / g.
Furthermore, the stability of the dispersion of the trimethylsilylated zirconium oxide particles (1) having a solid content concentration of 2.5% by weight was measured by the following method and standard, and was evaluated as ◎.

Stability evaluation The trimethylsilylated zirconium oxide particles (1) dispersion was filled in a transparent container and allowed to stand, and the state of precipitated particles was observed at the bottom of the container, evaluated according to the following criteria, and the results are shown in the table. .
No sedimentation layer of particles was observed for more than 1 week. : ◎
A sedimentation layer of particles was observed in 3 to 6 days. : ○
A sedimentation layer of particles was observed in 1 to 2 days. : △
Within 1 day, a sedimentation layer of particles was observed. : ×

[Production Example 2]
Preparation of Hydrophobic Zirconium Oxide Particles (2) Trimethylsilyl having a solid content concentration of 2.5% by weight in the same manner as in Production Example 1 except that 35.0 g of hexamethyldisilazane (HMDS) was used in the trimethylsilylation of Production Example 1. Zirconium oxide particle (2) dispersion was prepared. The refractive index of the trimethylsilylated zirconium oxide particles (2) was 1.63, the surface charge amount was 13 μeq / g, and the dispersion stability was 液.

[Production Example 3]
Preparation of Hydrophobic Zirconium Oxide Particles (3) Trimethylsilyl having a solid content concentration of 2.5% by weight in the same manner as in Production Example 1 except that 7.0 g of hexamethyldisilazane (HMDS) was used in trimethylsilylation in Production Example 1. Zirconium oxide particle (3) dispersion was prepared. The trimethylsilylated zirconium oxide particles (3) had a refractive index of 1.85, a surface charge of 28 μeq / g, and the dispersion stability was good.

[Production Example 4]
Preparation of hydrophobic silica-based hollow particles (1) Silica-based hollow fine particle-dispersed sol (manufactured by Catalytic Chemical Industry Co., Ltd .: Thruria 1420, average particle size 60 nm, concentration 20.5% by weight) Dispersion medium: isopropanol, particle refractive index 1.25) was diluted to obtain a silica-based hollow particle (1) dispersion having a solid content concentration of 1.5% by weight.

Formation of silica coating layer Silica-based hollow particles having a solid content concentration of 1.5% by weight (1) A dispersion of 1289 g of a dispersion, 1128 g of methanol and 20.7 g of an aqueous ammonia solution having a concentration of 28% by weight was heated to 35 ° C. Thereafter, a solution in which 31.94 g of methanol and 6.71 g of tetraethoxysilane (manufactured by Tama Chemical Industry Co., Ltd .: ethyl silicate-A, SiO ₂ content 28.8 wt%) were mixed with a roller pump over 6 hours. . Thereafter, the mixture was heated and stirred at 35 ° C. for 1 hour. Subsequently, the solvent was replaced with methanol using an ultrafiltration membrane to prepare a silica-coated silica-based hollow particle (1) methanol dispersion having a solid content concentration of 5% by weight.

Silica-coated silica-based hollow particles having a solid content concentration of 5% by weight in a trialkylsilylated separable flask (1) 700 g of methanol dispersion and 700 g of methanol were mixed and stirred sufficiently, and then a hydrophobizing agent (trialkylsilylating agent) ) 17.5 g of hexamethyldisilazane (HMDS) (manufactured by Wako Pure Chemical Industries, Ltd .: 1,1,1,1,3,3,3-hexamethyldisilazane) is added, and the temperature is raised to 50 ° C. Then, the mixture was heated and stirred for 22 hours to prepare a dispersion of trimethylsilylated silica-based hollow particles (1) having a solid content concentration of 2.5% by weight. The refractive index of the trimethylsilylated silica-based hollow particles (1) was 1.32.

Further, the surface charge amount of the trimethylsilylated silica-based hollow particles (1) was measured by the above-described measuring method and found to be 17 μeq / g.
Furthermore, the stability of the dispersion of the trimethylsilylated silica-based hollow particles (1) having a solid content concentration of 2.5% by weight was measured by the following method and standard, and was evaluated as ◎.

[Production Example 5]
Preparation of hydrophobic silica-based hollow particles (2) In the trimethylsilylation of Production Example 4, the solid content concentration was 2.5% by weight in the same manner as in Production Example 4 except that 35.0 g of hexamethyldisilazane (HMDS) was used. A dispersion of trimethylsilylated silica-based hollow particles (2) was prepared. The refractive index of the trimethylsilylated silica-based hollow particles (2) was 1.38, the surface charge amount was 13 μeq / g, and the dispersion stability was ◎.

[Production Example 6]
Preparation of hydrophobic silica-based hollow particles (3) In the trimethylsilylation of Production Example 4, a solid content concentration of 2.5% by weight was obtained in the same manner as in Production Example 4 except that 7.0 g of hexamethyldisilazane (HMDS) was used. A dispersion of trimethylsilylated silica-based hollow particles (2) was prepared. The refractive index of the trimethylsilylated silica-based hollow particles (2) was 1.29, the surface charge amount was 19 μeq / g, and the stability of the dispersion was ◎.

[Production Comparative Example 1]
Preparation of Hydrophobic Zirconium Oxide Particles (R1) Instead of using 17.5 g of hexamethyldisilazane (HMDS) as the trialkylsilylation in Example 1, γ-methacrylooxypropyltrimethoxy as the monoalkylsilylating agent Monoalkylsilylated zirconium oxide particles (R1) dispersion having a solid content concentration of 2.5 wt% in the same manner as in Production Example 1 except that 17.5 g of silane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM-503) was used Was prepared. The monoalkylsilylated zirconium oxide particles (R1) had a refractive index of 1.73, a surface charge of 45 μeq / g, and the stability of the dispersion was Δ.

[Production Comparative Example 2]
Preparation of hydrophobic silica-based hollow particles (R2) In the trialkylsilylation of Production Example 4, instead of 17.5 g of hexamethyldisilazane (HMDS), γ-methacrylooxypropyltrimethoxy was used as a monoalkylsilylating agent. Monoalkylsilylated hydrophobic silica-based hollow particles (R2 having a solid content concentration of 2.5% by weight in the same manner as in Production Example 4 except that 17.5 g of silane (manufactured by Shin-Etsu Chemical Co., Ltd .: KBM-503) was used. ) A dispersion was prepared. The monoalkylsilylated hydrophobic silica-based hollow particles (R2) had a refractive index of 1.33, a surface charge of 30 μeq / g, and the dispersion stability was Δ.

  Table 1 shows the characteristics of the particles prepared in the above production examples.

［実施例1］
塗料(1-1)の調製
製造例１で調製した固形分濃度２．５重量％のトリメチルシリル化した酸化ジルコニウム粒子(1)分散液１２８ｇにシリコーン樹脂（信越化学（株）製：ＫＥ−１０９Ｅ・Ｂ）１．０ｇを添加し、ロータリーエバポレーターで、温浴の温度を５０℃にし、徐々に減圧を高め２時間で溶媒を除去して塗料(1-1)を調製した。塗料(1-1)中の固形分１００重量％に対する溶剤の濃度は０．１重量％であった。

[Example 1]
Preparation of paint (1-1) A trimethylsilylated zirconium oxide particle (1) having a solid content concentration of 2.5% by weight prepared in Production Example 1 (1) was dispersed in 128 g of a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E). B) 1.0 g was added, the temperature of the warm bath was adjusted to 50 ° C. with a rotary evaporator, the pressure was gradually increased and the solvent was removed in 2 hours to prepare paint (1-1). The concentration of the solvent relative to 100% by weight of the solid content in the paint (1-1) was 0.1% by weight.

The stability of the obtained paint (1-1) was measured by the following method and standard, and was evaluated as ◎.
The stability was evaluated by the following method and evaluation criteria.

Stability evaluation paint (1-1) was filled in a transparent container and allowed to stand, and the state of precipitated particles was observed at the bottom of the container, and evaluated according to the following criteria.
No sedimentation layer of particles was observed for more than 1 week. : ◎
A sedimentation layer of particles was observed in 3 to 6 days. : ○
A sedimentation layer of particles was observed in 1 to 2 days. : △
Within 1 day, a sedimentation layer of particles was observed. : ×
Preparation of paint (1-2) Prepare paint (1-2) by mixing 0.5 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E • A) with 2.1 g of paint (1-1). did.

[Example 2]
Preparation of paint (2-1) A silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E) was added to 128 g of the trimethylsilylated zirconium oxide particles (2) dispersion having a solid content concentration of 2.5% by weight prepared in Production Example 2. B) 1.0 g was added, the temperature of the warm bath was adjusted to 50 ° C. with a rotary evaporator, the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare paint (2-1). The concentration of the solvent relative to 100% by weight of the solid content in the paint (2-1) was 0.2% by weight.
The stability of the obtained paint (2-1) was ◎.

Preparation of paint (2-2) Prepare paint (2-2) by mixing 0.5 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E · A) with 2.1 g of paint (2-1). did.

[Example 3]
Preparation of Paint (3-1) Silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E) was added to 128 g of the trimethylsilylated zirconium oxide particles (3) dispersion having a solid content concentration of 2.5% by weight prepared in Production Example 3. B) 1.0 g was added, the temperature of the warm bath was adjusted to 50 ° C. with a rotary evaporator, the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare paint (3-1). The concentration of the solvent relative to 100% by weight of the solid content in the paint (3-1) was 0.1% by weight.
The stability of the obtained paint (3-1) was good.

Preparation of paint (3-2) 2.1 g of paint (3-1) is mixed with 0.5 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E · A) to prepare paint (3-2). did.

[Example 4]
Preparation of paint (4-2) 1.9 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E · A) was mixed with 2.1 g of paint (3-2) prepared in the same manner as in Example 3. A paint (4-2) was prepared.

[Example 5]
Preparation of paint (5-2) 5.9 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E · A) was mixed with 2.1 g of paint (3-2) prepared in the same manner as in Example 3. A paint (4-2) was prepared.

[Example 6]
Preparation of Paint (6-1) A trimethylsilylated silica-based hollow particle (4) having a solid content concentration of 2.5% by weight prepared in Production Example 4 was added to 128 g of a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E). B) 1.0 g was added, the temperature of the warm bath was adjusted to 50 ° C. with a rotary evaporator, the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare paint (6-1). The concentration of the solvent relative to 100% by weight of the solid content in the paint (6-1) was 0.1% by weight.
The stability of the obtained paint (6-1) was ◎.

Preparation of paint (6-2) Prepare paint (6-2) by mixing 0.5 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E · A) with 2.1 g of paint (6-1). did.

[Example 7]
Preparation of coating material (7-1) Silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E) was added to 128 g of the trimethylsilylated silica-based hollow particle (5) dispersion having a solid concentration of 2.5% by weight prepared in Production Example 5. B) 1.0 g was added, the temperature of the warm bath was adjusted to 50 ° C. with a rotary evaporator, the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare paint (7-1). The concentration of the solvent with respect to 100% by weight of the solid content in the paint (7-1) was 0.1% by weight.
The stability of the obtained paint (7-1) was ◎.

Preparation of paint (7-2) Prepare paint (7-2) by mixing 0.5 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E • A) with 2.1 g of paint (7-1). did.

[Example 8]
Preparation of Coating Material (8-1) Silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E) was added to 128 g of the trimethylsilylated silica-based hollow particle (6) dispersion having a solid content concentration of 2.5% by weight prepared in Production Example 6. B) 1.0 g was added, the temperature of the warm bath was adjusted to 50 ° C. with a rotary evaporator, the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare paint (8-1). The concentration of the solvent relative to 100% by weight of the solid content in the paint (8-1) was 0.1% by weight.
The stability of the obtained paint (8-1) was ◎.

Preparation of paint (8-2) 2.1 g of paint (8-1) is mixed with 0.5 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E · A) to prepare paint (8-2). did.

[Example 9]
Preparation of paint (9-2) Paint (1-2) prepared in Example 1 and paint (4-2) prepared in Example 6 were mixed at a weight ratio of 8: 2, and paint (9-2) Was prepared.

[Example 10]
Preparation of paint (10-2) Paint (1-2) prepared in Example 1 and paint (4-2) prepared in Example 6 were mixed at a weight ratio of 5: 5 to give paint (10-2) Was prepared.

[Example 11]
Preparation of paint (11-2) Paint (1-2) prepared in Example 1 and paint (4-2) prepared in Example 6 were mixed at a weight ratio of 2: 8 to prepare paint (11-2) Was prepared.

[Example 12]
Preparation of paint (12-1) An epoxy acrylate resin (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK Oligo) was added to 128 g of trimethylsilylated zirconium oxide particles (1) dispersion having a solid content concentration of 2.5% by weight prepared in Production Example 3. EA-5824) 1.0 g was added, the temperature of the warm bath was adjusted to 50 ° C. with a rotary evaporator, the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare paint (12-1). The concentration of the solvent relative to 100% by weight of the solid content in the paint (12-1) was 0.1% by weight.
The stability of the obtained paint (12-1) was ◎.

Preparation of paint (12-2) 2.1 g of paint (12-1), 0.5 g of epoxy acrylate resin (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK OligoEA-1020) and photopolymerization initiator (Ciba Japan ( Co., Ltd .: Irgacure 184) 0.06 g was mixed to prepare paint (12-2).

[Example 13]
Preparation of paint (13-1) Epoxy acrylate resin (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK) was added to 128 g of the trimethylsilylated silica-based hollow particle (4) dispersion having a solid concentration of 2.5% by weight prepared in Production Example 4. OligoEA-5824) (1.0 g) was added, and the temperature of the hot bath was adjusted to 50 ° C. with a rotary evaporator, the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare paint (13-1). The concentration of the solvent relative to 100% by weight of the solid content in the paint (13-1) was 0.1% by weight.
The stability of the obtained paint (13-1) was ◎.

Preparation of paint (13-2) 2.1 g of paint (13-1), 0.5 g of epoxy acrylate resin (manufactured by Shin-Nakamura Chemical Co., Ltd .: NK OligoEA-1020) and photopolymerization initiator (Ciba Japan ( Co., Ltd .: Irgacure 184) 0.06 g was mixed to prepare paint (13-2).

[Comparative Example 1]
Preparation of paint (R1-1) 128 g of monoalkylsilylated zirconium oxide particle (R1) dispersion having a solid content concentration of 2.5% by weight prepared in Production Comparative Example 1 was added to a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE). -109E · B) 1.0 g was added, the temperature of the warm bath was adjusted to 50 ° C. with a rotary evaporator, the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare paint (R1-1). The concentration of the solvent relative to 100% by weight of the solid content in the paint (R1-1) was 0.1% by weight. The stability of the obtained paint (R1-1) was Δ.

Preparation of paint (R1-2) 2.1 g of paint (R1-1) is mixed with 0.5 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E · A) to prepare paint (R1-2). did.

[Comparative Example 2]
Preparation of paint (R2-1) 128 g of monoalkylsilylated silica-based hollow particle (R2) dispersion having a solid content concentration of 2.5% by weight prepared in Production Comparative Example 2 was added to a silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: (KE-109E · B) (1.0 g) was added, and the temperature of the warm bath was adjusted to 50 ° C. with a rotary evaporator, the degree of vacuum was gradually increased, and the solvent was removed in 2 hours to prepare a paint (R2-1). The concentration of the solvent relative to 100% by weight of the solid content in the paint (R2-1) was 0.1% by weight. The stability of the obtained paint (R2-1) was Δ.

Preparation of paint (R2-2) Prepare paint (R2-2) by mixing 0.5 g of silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd .: KE-109E · A) with 2.1 g of paint (R2-1). did.
The composition of the obtained paint is shown in Table 2.

［実施例14］（単層との区別をつけるために積層といれておきます）
積層封止層(1)の形成
実施例１で調製した塗料(1-2)をガラス基板（厚さ：３．０ｍｍ、屈折率：１．４６、全光線透過率９２．０％、ヘーズ０．１％）にバーコーター法（バー＃５０）で塗布し、８０℃で３時間、熱処理して硬化させ、厚さ５０μｍの第１封止層を形成した。

[Example 14] (In order to distinguish it from a single layer, it is referred to as a laminate.)
Formation of laminated sealing layer (1) Paint (1-2) prepared in Example 1 was applied to a glass substrate (thickness: 3.0 mm, refractive index: 1.46, total light transmittance 92.0%, haze 0 0.1%) by a bar coater method (bar # 50), and cured by heat treatment at 80 ° C. for 3 hours to form a first sealing layer having a thickness of 50 μm.

Subsequently, the coating material (6-2) prepared in Example 6 was applied and cured in the same manner to form a two-layer laminated sealing layer (1).
At this time, the thickness of the sealing layer (1) was 100 μm. The total light transmittance and haze of the obtained sealing layer (1) were measured with a haze meter (NDH-300A manufactured by Nippon Denshoku Industries Co., Ltd.), and the results are shown in Table 3. Furthermore, the refractive index and pencil hardness of the sealing layer (1) were evaluated by the following methods and evaluation criteria, and the results are shown in Table 3.

Refractive index In place of the glass substrate, paint (1-2) is applied and cured in the same manner on a silicon wafer to form a 50 μm-thick coating film, which is first sealed with an ellipsometer (manufactured by SOPRA: ESVG). The refractive index of the stop layer was measured. Similarly, the refractive index of the second sealing layer was measured using paint (4-2), and the results are shown in Table 3.

Measurement of pencil hardness It measured with the pencil hardness tester according to JIS-K-5400.

[Example 15]
Formation of laminated sealing layer (2) Paint (3-2) prepared in Example 3 was applied to a glass substrate (thickness: 3.0 mm, refractive index: 1.46, total light transmittance 92.0%, haze 0 0.1%) by a bar coater method (bar # 50), and cured by heat treatment at 80 ° C. for 3 hours to form a first sealing layer having a thickness of 50 μm.

Next, the coating material (10-2) prepared in Example 10 was applied and cured in the same manner to form a second sealing layer having a thickness of 50 μm. Further, the coating material (6-2) prepared in Example 6 was applied and cured in the same manner to form a three-layer sealing layer (2).
At this time, the thickness of the laminated sealing layer (2) was 150 μm. Further, the total light transmittance, haze, refractive index and pencil hardness of the laminated sealing layer (2) were measured, and the results are shown in Table 3.

[Example 16]
Formation of laminated sealing layer (3) Paint (3-2) prepared in Example 3 was applied to a glass substrate (thickness: 3.0 mm, refractive index: 1.46, total light transmittance 92.0%, haze 0 0.1%) by a bar coater method (bar # 50), and cured by heat treatment at 80 ° C. for 3 hours to form a first sealing layer having a thickness of 50 μm.

Subsequently, the coating material (9-2) prepared in Example 9 was applied and cured in the same manner to form a second sealing layer having a thickness of 50 μm. Further, the coating material (10-2) prepared in Example 10 was applied and cured in the same manner to form a third sealing layer having a thickness of 50 μm, on which the coating material (11-2) prepared in Example 11 was formed. ) Was applied and cured in the same manner to form a fourth sealing layer having a thickness of 50 μm.
And the coating material (6-2) prepared in Example 6 was applied and cured in the same manner to form a laminated sealing layer (3) comprising 5 layers.
At this time, the thickness of the laminated sealing layer (3) was 250 μm. Further, the total light transmittance, haze, refractive index and pencil hardness of the laminated sealing layer (3) were measured, and the results are shown in Table 3.

[Example 17]
Formation of laminated sealing layer (4) Paint (3-2) prepared in Example 3 was applied to a glass substrate (thickness: 3.0 mm, refractive index: 1.46, total light transmittance 92.0%, haze 0 0.1%) by a bar coater method (bar # 50), and cured by heat treatment at 80 ° C. for 3 hours to form a first sealing layer having a thickness of 50 μm.

Subsequently, the coating material (4-2) prepared in Example 4 was applied and cured in the same manner to form a second sealing layer having a thickness of 50 μm. Further, the coating material (5-2) prepared in Example 5 was applied and cured in the same manner to form a third sealing layer having a thickness of 50 μm. Then, the coating layer (6-2) prepared in Example 6 was applied and cured in the same manner to form a four-layer sealing lamination stopper layer (4).
At this time, the thickness of the laminated sealing layer (4) was 200 μm. Further, the total light transmittance, haze, refractive index and pencil hardness of the laminated sealing layer (3) were measured, and the results are shown in Table 3.

[Example 18]
Formation of laminated sealing layer (5) The paint (12-2) prepared in Example 12 was applied to a glass substrate (thickness: 3.0 mm, refractive index: 1.46, total light transmittance 92.0%, haze 0). 1%), coated by the bar coater method (bar # 50), dried at 80 ° C. for 3 minutes, cured by irradiation with 600 mJ / cm ² with a UV irradiator (high pressure mercury lamp), and first sealed with a thickness of 50 μm A stop layer was formed.

Subsequently, the coating material (13-2) prepared in Example 13 was applied and cured in the same manner to form a two-layer sealing layer (5).
At this time, the thickness of the laminated sealing layer (5) was 100 μm. Further, the total light transmittance, haze, refractive index and pencil hardness of the laminated sealing layer (5) were measured, and the results are shown in Table 3.

[Comparative Example 3]
Preparation of single-layer sealing layer (R1) Paint (2-2) prepared in Example 2 was applied to a glass substrate (thickness: 3.0 mm, refractive index: 1.46, total light transmittance 92.0%, haze) 0.1%) was applied by a bar coater method (bar # 50), and was cured by heat treatment at 80 ° C. for 3 hours to prepare a sealing layer (1) having a thickness of 50 μm. The total light transmittance, haze, refractive index and pencil hardness of the sealing layer (R1) were measured, and the results are shown in Table 3.

[Comparative Example 4]
Preparation of Single Layer Sealing Layer (R2) The paint (9-2) prepared in Example 9 was applied to a glass substrate (thickness: 3.0 mm, refractive index: 1.46, total light transmittance 92.0%, haze) 0.1%) was applied by a bar coater method (bar # 50), and was cured by heat treatment at 80 ° C. for 3 hours to prepare a sealing layer (R3) having a thickness of 50 μm. The total light transmittance, haze, refractive index and pencil hardness of the sealing layer (R3) were measured, and the results are shown in Table 3.

[Comparative Example 5]
Preparation of Single-layer Sealing Layer (R3) Paint (4-2) prepared in Example 4 was applied to a glass substrate (thickness: 3.0 mm, refractive index: 1.46, total light transmittance 92.0%, haze) 0.1%) was applied by a bar coater method (bar # 50), and was cured by heat treatment at 80 ° C. for 3 hours to prepare a sealing layer (R3) having a thickness of 50 μm. The total light transmittance, haze, refractive index and pencil hardness of the sealing layer (R3) were measured, and the results are shown in Table 3.

Claims (10)

And at least one hydrophobic particles of the hydrophobic silica-based hollow particles with an average particle size an average particle diameter of the hydrophobic zirconium oxide particles in the range of 5~50nm is in the range of 5 to 200 nm, including a matrix resin component A coating material for sealing material,
The content of the hydrophobic particles is in the range of 10 to 90% by weight ,
The hydrophobic particles include a silica coating layer provided on a surface and a trialkylsilyl group provided on the surface of the silica coating layer . The trialkylsilyl group is contained in the hydrophobic particles in a range of 10 to 100% by weight as a solid content (R ₃ —SiO _1/2 ) with respect to the zirconium oxide particles and the silica-based hollow particles. The coating material for sealing materials according to claim 1. The coating material for a sealing material according to claim 1 or 2 , wherein the matrix resin component is an epoxy resin or a silicone resin. Light emitting diode and having a sealing layer formed by formed using the paint sealing material according to any one of claims 1-3. A light-emitting diode having a laminated sealing layer laminated in order of high refractive index from the lowermost sealing layer (first sealing layer) to the uppermost sealing layer (n-th sealing layer),
The lowermost sealing layer has a refractive index n ₁ in the range of 1.55 to 1.85,
The refractive index n _n of the uppermost sealing layer is in the range of 1.30 to 1.65,
Each sealing layer of the laminated sealing layer comprises at least one hydrophobic particle of hydrophobic zirconium oxide particles having an average particle size of 5 to 50 nm, hydrophobic silica-based hollow particles having an average particle size of 5 to 200 nm, and a matrix Including resin components,
The hydrophobic particle includes a silica coating layer provided on a surface and a trialkylsilyl group provided on the surface of the silica coating layer . The trialkylsilyl group is contained in the hydrophobic particles in a range of 10 to 100% by weight as a solid content (R ₃ —SiO _1/2 ) with respect to the zirconium oxide particles and the silica-based hollow particles. The light emitting diode according to claim 5 . 7. The light emitting diode according to claim 5, wherein the matrix resin is an epoxy resin or a silicone resin. 8. The light-emitting diode according to claim 5 , wherein the content of the hydrophobic particles in each sealing layer is in the range of 10 to 90 wt%. The light emitting diode according to any one of claims 5 to 8 , wherein a thickness of the laminated sealing layer is in a range of 0.1 to 5 mm. The light-emitting diode according to claim 5 , wherein the laminated sealing layer has a light transmittance of 80% or more.

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