JP2019033256A - Dispersion liquid, composition, sealing member, light emitting device, lighting device, and display device - Google Patents

Abstract

To provide a dispersion liquid containing a metal oxide particles having a refractive index of 1.7 or more to which a surface modifying material is attached and capable of improving light extraction efficiency, a composition containing the same, a sealing member formed using the composition, a light emitting device having the sealing member, and a lighting device and a display device including the light emitting device.SOLUTION: A dispersion liquid for sealing a light emitting element includes a metal oxide particle having a refractive index of 1.7 or more and a surface modifying material at least a part of which is attached to the metal oxide particle, and the particle size D50 of the metal oxide particles when the cumulative percentage of the scattering intensity distribution obtained by a dynamic light scattering method is 50% is larger than 20 nm and 100 nm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a dispersion, a composition, a sealing member, a light emitting device, a lighting fixture, and a display device including metal oxide particles having a refractive index of 1.7 or more to which a surface modifying material is attached.

  Light emitting diodes (LEDs) are widely used as light sources having advantages such as small size, long life, and low voltage driving. In general, an LED chip in an LED package is sealed with a sealing material including a resin in order to prevent contact with deterioration factors existing in an external environment such as oxygen and moisture. Therefore, the light emitted from the LED chip is emitted toward the outside through the sealing material. Therefore, in order to increase the luminous flux emitted from the LED package, it is important to efficiently extract the light emitted from the LED chip to the outside of the LED package.

  As a sealing material for improving the extraction efficiency of light emitted from the LED chip, inorganic oxide particles having a dispersed particle diameter of 1 nm or more and 20 nm or less and a refractive index of 1.8 or more, a silicone resin, The composition formed by containing is proposed (patent document 1).

  In this composition, a dispersion containing inorganic oxide particles having a small dispersed particle size and a high refractive index is mixed with a silicone resin. Therefore, the inorganic oxide particles in the composition can improve the refractive index of the sealing material, and when the light emitted from the LED chip enters the sealing material, at the interface between the LED chip and the sealing material. Total reflection of light can be suppressed. Moreover, since the dispersion | distribution particle size of an inorganic oxide particle is small, the fall of the transparency of sealing material is suppressed. As a result, the light extraction efficiency from the LED chip can be improved.

JP 2007-299981 A

  However, in order to further increase the luminous flux emitted from the light emitting device such as an LED package, further improvement in light extraction efficiency has been demanded.

The present invention has been made to solve the above-described problems, and can improve the light extraction efficiency of a light-emitting device, and a metal oxide having a refractive index of 1.7 or more to which a surface modifying material is attached. Dispersion liquid containing particles, composition containing the same, sealing member formed using the composition, light-emitting device having the sealing member, and lighting apparatus and display device including the light-emitting device For the purpose.

  In order to solve the above-described problems, according to one aspect of the present invention, a metal oxide particle having a refractive index of 1.7 or more and a surface modification material that is at least partially attached to the metal oxide particle are included. The particle diameter D50 of the metal oxide particles when the cumulative percentage of the scattering intensity distribution obtained by the dynamic light scattering method is 50% is larger than 20 nm and not larger than 100 nm, for sealing a light emitting element. A dispersion is provided.

  The surface modifying material may have at least one functional group selected from the group consisting of an alkenyl group, an H—Si group, and an alkoxy group.

  Moreover, in order to solve the said subject, according to another viewpoint of this invention, the composition for sealing the light emitting element containing the said dispersion liquid and the resin component is provided.

Moreover, in order to solve the said subject, according to another viewpoint of this invention, the sealing member which is the hardened | cured material of the said composition is provided.
Moreover, in order to solve the said subject, according to another viewpoint of this invention, a light-emitting device provided with the said sealing member and the light emitting element sealed with the said sealing member is provided.
Moreover, in order to solve the said subject, according to another viewpoint of this invention, the lighting fixture provided with the said light-emitting device is provided.
Moreover, in order to solve the said subject, according to another viewpoint of this invention, the display apparatus provided with the said light-emitting device is provided.

  As described above, according to the present invention, it is possible to improve the light extraction efficiency of the light emitting device, and a dispersion containing metal oxide particles having a refractive index of 1.7 or more to which a surface modifying material is attached, and a composition containing the same Product, a sealing member formed using the composition, a light-emitting device having the sealing member, and a lighting fixture and a display device including the light-emitting device can be provided.

It is a schematic diagram which shows an example of the light-emitting device which concerns on embodiment of this invention. It is a schematic diagram which shows another example of the light-emitting device which concerns on embodiment of this invention. It is a schematic diagram which shows another example of the light-emitting device which concerns on embodiment of this invention. It is a schematic diagram which shows another example of the light-emitting device which concerns on embodiment of this invention.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

<1. Dispersion>
As will be described later, the dispersion according to this embodiment is mixed with a resin component and used as a sealing member in a light emitting device for sealing a light emitting element. The dispersion according to this embodiment contains metal oxide particles having a refractive index of 1.7 or more and a surface modifying material that is at least partially adhered to the metal oxide particles.

(1.1 Metal oxide particles)
The metal oxide particles contained in the dispersion according to this embodiment have a refractive index of 1.7 or more, and improve the refractive index of the sealing member. The metal oxide particles are used for light scattering in the sealing member as will be described later.

  The metal oxide particles used in the present embodiment are not particularly limited as long as the refractive index is 1.7 or more. The refractive index of such metal oxide particles is preferably 1.8 or more, more preferably 1.9 or more, and even more preferably 2 from the viewpoint of improving the refractive index of the sealing member and improving the light scattering effect. 0.0 or more.

  Examples of the metal oxide particles containing one metal element and having a refractive index of 1.7 or more include zirconium oxide particles, titanium oxide particles, zinc oxide particles, iron oxide particles, aluminum oxide particles, copper oxide particles, and tin oxide. Particles, yttrium oxide particles, cerium oxide particles, tantalum oxide particles, niobium oxide particles, molybdenum oxide particles, indium oxide particles, antimony oxide particles, germanium oxide particles, lead oxide particles, bismuth oxide particles, tungsten oxide particles, europium oxide particles, And one or more selected from the group consisting of hafnium oxide particles are preferably used.

  Examples of the metal oxide particles containing two kinds of metal elements and having a refractive index of 1.7 or more include potassium titanate particles, barium titanate particles, strontium titanate particles, potassium niobate particles, lithium niobate particles, tungsten Calcium oxide particles, yttria stabilized zirconia particles, alumina stabilized zirconia particles, silica stabilized zirconia particles, calcia stabilized zirconia particles, magnesia stabilized zirconia particles, scandia stabilized zirconia particles, hafnia stabilized zirconia particles, ytterbia stabilized zirconia particles Particles, ceria stabilized zirconia particles, india stabilized zirconia particles, strontium stabilized zirconia particles, samarium oxide stabilized zirconia particles, gadolinium oxide stabilized zirconia particles, antimony-doped tin oxide particles, and One or more selected from the group consisting of indium-doped tin oxide particles are suitably used. Note that metal oxide particles containing three or more metal elements can also be used as long as the refractive index is 1.7 or more. Moreover, you may use suitably combining the metal oxide particle containing 1 type, 2 types, and 3 or more types of metal elements mentioned above.

  Among these metal oxide particles, from the viewpoint of obtaining a dispersion having a high refractive index and high transparency, the metal oxide particles are preferably zirconium oxide particles and / or titanium oxide particles, more preferably zirconium oxide particles. including.

  In this embodiment, the particle diameter D50 of the metal oxide particles (metal oxide particles to which the surface modifying material is attached) when the cumulative percentage of the scattering intensity distribution obtained by the dynamic light scattering method is 50% is 20 nm. It is larger and 100 nm or less.

  In the dispersion liquid of this embodiment, the particle diameter D50 (hereinafter also simply referred to as “D50”) of the metal oxide particles when the cumulative percentage of the scattering intensity distribution obtained by the dynamic light scattering method is 50% is larger than 20 nm. The reason why the thickness is 100 nm or less is as follows.

  Conventionally, in order to improve the light extraction efficiency, it has been considered that the transparency (transmittance) of a composition used as a sealing material is preferably higher. For this reason, it has been considered that the D50 of the metal oxide particles in the dispersion is preferably as small as possible.

However, the present inventors set the D50 of the metal oxide particles in the dispersion to be greater than 20 nm and less than or equal to 100 nm, and more light emitted from the light emitting element is contained in the sealing member (cured body) and composition described later. It has been found that the light extraction efficiency of the sealing member is improved by scattering even if the transparency of the dispersion or the composition itself is somewhat lowered.
From the viewpoint of further improving the light extraction efficiency, D50 of the metal oxide particles is preferably 30 nm or more and 100 nm or less, more preferably 30 nm or more and 80 nm or less, and further preferably 30 nm or more and 70 nm or less.

When D50 is 20 nm or less, a sufficient light scattering effect cannot be obtained, and when a composition described later is used as a sealing material, the light extraction efficiency is reduced, which is not preferable.
On the other hand, when D50 exceeds 100 nm, the transmittance of the composition to be described later becomes too low, which is not preferable because the light extraction efficiency becomes low when used as a sealing material.

  The D50 of the metal oxide particles can be measured by a dynamic light scattering type particle size distribution meter (for example, model number: SZ-100SP manufactured by HORIBA). The measurement can be performed using a quartz cell having an optical path length of 10 mm × 10 mm for a dispersion whose solid content is adjusted to 5% by mass. In the present specification, the “solid content” refers to a residue when a component that can be volatilized in a dispersion is removed. For example, when 1.2 g of the dispersion is put in a magnetic crucible and heated at 150 ° C. for 1 hour on a hot plate, the components that remain without volatilization (such as metal oxide particles and surface modification materials) are solids. be able to.

  D50 of the metal oxide particles in the present embodiment is a value measured and calculated based on the dispersed particle diameter of the metal oxide particles in the dispersion. D50 is measured and calculated based on the diameter of the metal oxide particles in a dispersed state regardless of whether the metal oxide particles are dispersed in a primary particle state or a secondary particle state. Moreover, in this embodiment, D50 of a metal oxide particle may be measured as D50 of the metal oxide particle to which the surface modification material adhered. Since there may be metal oxide particles to which the surface modifying material is attached and metal oxide particles to which the surface modifying material is not attached in the dispersion liquid, the D50 of the metal oxide particles is usually a mixture of these. Measured as value in state.

  The average primary particle diameter of the metal oxide particles is, for example, 3 nm to 20 nm, preferably 4 nm to 20 nm, more preferably 5 nm to 20 nm. When the average primary particle diameter is in the above range, it becomes easy to control D50 to be larger than 20 nm and not larger than 100 nm.

As a method for measuring the average primary particle size, a predetermined number, for example, 100 metal oxide particles are selected.
And the longest straight line part (maximum long diameter) of each of these metal oxide particles is measured, and these measured values are obtained by arithmetic averaging.
Here, when the metal oxide particles are aggregated, the aggregated particle diameter of the aggregate is not measured. A predetermined number of maximum long diameters of the metal oxide particle particles (primary particles) constituting the aggregate are measured to obtain an average primary particle diameter.

  The content of the metal oxide particles having a refractive index of 1.7 or more in the dispersion according to the present embodiment may be appropriately adjusted according to desired characteristics. From the viewpoint of achieving both light scattering properties and transparency, it is preferably 1% by mass to 70% by mass, more preferably 5% by mass to 50% by mass, and further preferably 5% by mass to 30% by mass.

The above description does not exclude that the dispersion contains metal oxide particles having a refractive index of less than 1.7. The dispersion may contain metal oxide particles having a refractive index of less than 1.7 in addition to metal oxide particles having a refractive index of 1.7 or more depending on the purpose.
Moreover, the surface modification material demonstrated below has adhered to the surface of the metal oxide particle demonstrated above. Thereby, metal oxide particles are stably dispersed in the dispersion.

(1.2 Surface modification material)
The dispersion according to this embodiment includes a surface modifying material. In the dispersion, at least a part of the surface modifying material adheres to the surface of the metal oxide particles to prevent the metal oxide particles from aggregating. Furthermore, compatibility with the resin component mentioned later is improved.

  Here, the phrase “the surface modifying material“ attaches ”to the metal oxide particles means that the surface modifying material contacts or bonds to the metal oxide particles by the interaction between them. Examples of the contact include physical adsorption. Examples of the bond include ionic bond, hydrogen bond, and covalent bond.

Such a surface modifying material is not particularly limited as long as it can adhere to the metal oxide particles and has good compatibility between the dispersion medium and the resin component.
As such a surface modifying material, a surface modifying material having at least one functional group selected from the group consisting of reactive functional groups such as alkenyl groups, H-Si groups, and alkoxy groups is preferably used. The surface modifying material having such a functional group is excellent in affinity with the dispersion medium and the resin component described later, and can improve the dispersibility of the metal oxide particles in the dispersion or composition.

As the alkenyl group, for example, a linear or branched alkenyl group having 2 to 5 carbon atoms can be used, and specific examples include a vinyl group, a 2-propenyl group, a prop-2-en-1-yl group, and the like. It is done.
As an alkoxy group, a C1-C5 linear or branched alkoxy group is mentioned, for example, Specifically, a methoxy group, an ethoxy group, n-propoxy group, an isopropoxy group, a butoxy group etc. are mentioned.

  Examples of the surface modifying material having at least one functional group selected from the group consisting of an alkenyl group, an H-Si group, and an alkoxy group include the following silane compounds, silicone compounds, and carbon-carbon unsaturated bond-containing fatty acids. Of these, one of them can be used alone or two or more of them can be used in combination.

  Examples of the silane compound include vinyltrimethoxysilane, isobutyltrimethoxysilane, phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, dimethylchlorosilane, methyldichlorosilane, diethylchlorosilane, ethyldichlorosilane, Methylphenylchlorosilane, diphenylchlorosilane, phenyldichlorosilane, trimethoxysilane, dimethoxysilane, monomethoxysilane, triethoxysilane, diethoxymonomethylsilane, monoethoxydimethylsilane, methylphenyldimethoxysilane, diphenylmonomethoxysilane, methylphenyldiethoxy One or more selected from the group consisting of silane and diphenylmonoethoxysilane It is preferable to have.

Examples of the silicone compound include methyl hydrogen silicone, dimethyl hydrogen silicone, methyl phenyl hydrogen silicone, phenyl hydrogen silicone, alkoxy both-end phenyl silicone, alkoxy group-containing phenyl silicone, alkoxy one-end vinyl one-end phenyl silicone, methyl One selected from the group consisting of phenyl silicone, alkoxy both-end methyl phenyl silicone, alkoxy group-containing dimethyl silicone, alkoxy group-containing methyl phenyl silicone, alkoxy one-end trimethyl one-end dimethyl silicone, and alkoxy one-end vinyl one-end dimethyl silicone Or it is preferable to use 2 or more types.
The silicone compound may be an oligomer or a resin (polymer).
Examples of the carbon-carbon unsaturated bond-containing fatty acid include methacrylic acid and acrylic acid.

  Among these surface-modifying materials, vinyltrimethoxysilane, isobutyltrimethoxysilane are used from the viewpoint of suppressing aggregation of metal oxide particles and easily obtaining a highly transparent sealing member in dispersions and compositions. It is preferable to use one or more selected from the group consisting of phenyltrimethoxysilane, alkoxy-terminated trimethyl-terminated dimethylsilicone, and methylphenylsilicone.

  From the viewpoint of suppressing aggregation of inorganic oxide particles in the dispersion and easily obtaining a highly transparent sealing member, it is preferable to modify the surface with both a silane compound and a silicone compound. That is, the dispersion preferably contains at least one silane compound and at least one silicone compound. Preferred examples of the silane compound include vinyltrimethoxysilane, isobutyltrimethoxysilane, and phenyltrimethoxysilane. Preferred examples of the silicone compound include alkoxy one-terminal trimethyl one-end dimethyl silicone, methoxy group-containing phenyl silicone, and methylphenyl silicone.

  The content of the surface modifying material in the dispersion of the present embodiment is preferably 1% by mass to 80% by mass, more preferably 5% by mass to 40% by mass with respect to the mass of the metal oxide particles.

  In the dispersion according to this embodiment, the content of the free surface modifying material is preferably 53% by mass or less, more preferably 50% by mass or less, based on the total content of the metal oxide particles and the surface modifying material. It is. In the present specification, the “free surface modifying material” means a surface modifying material that is not attached to the metal oxide particles.

The lower limit of the free surface modifying material is not limited, but the content of the free surface modifying material is, for example, 0% by mass or 0% by mass or more based on the total content of the metal oxide particles and the surface modifying material. 10 mass% or more, 20 mass% or more, or 30 mass% or more may be sufficient.
In view of suppressing an increase in the viscosity of the composition to be described later, the content of the free surface modifying material is preferably 20% by mass or more, more preferably 30% by mass or more, and 35% by mass or more. More preferably it is.
When the free surface modifying material is present, the free surface modifying material remains in the composition described later even if the dispersion medium is removed. If a large amount of free surface modifying material is present in the composition, the amount of metal oxide particles to which the surface modifying material is attached is relatively small, and it is estimated that the viscosity of the composition can be suppressed.

  The content of the free surface modifying material is a value calculated by the following method, for example, and is calculated based on the mass of the surface modifying material that can be extracted from the dispersion with a good solvent for the surface modifying material such as acetone.

The liquid in 5 g of the dispersion is removed with an evaporator to obtain a concentrate. Next, 2 g of acetone is added to the concentrate and mixed to prepare a mixed solution.
The extract separated from the mixed solution is collected by column chromatography using 10 cc of silica gel and 100 cc of a developing solvent (mixed hexane and acetone in a volume ratio of 2: 1). The liquid in the extract is removed by an evaporator, and the obtained residue is assumed to be a free surface modifying material and its mass is measured. The result of calculating the percentage of the value obtained by dividing the mass of the residue by the total mass of the metal oxide particles and the surface modifying material contained in 5 g of the dispersion liquid of this embodiment is defined as the content of the free surface modifying material.

  Examples of the method for attaching the surface modifying material to the metal oxide particles include a dry method in which the surface modifying material is directly mixed and sprayed on the metal oxide particles, or a metal in water or an organic solvent in which the surface modifying material is dissolved. There is a wet method in which oxide particles are introduced and the surface is modified in a solvent.

(1.3 Dispersion medium)
In addition, the dispersion according to this embodiment usually includes a dispersion medium in which metal oxide particles are dispersed. The dispersion medium is not particularly limited as long as it can disperse metal oxide particles having a refractive index of 1.7 or more to which a surface modifying material is attached and can be mixed with a resin component described later.
Examples of such a dispersion medium include organic solvents such as alcohols, ketones, aromatics, saturated hydrocarbons, and unsaturated hydrocarbons. These solvents may be used alone or in combination of two or more.
From the viewpoint of compatibility with the silicone resin described later, an organic solvent having an aromatic ring, that is, aromatics is preferable, and aromatic hydrocarbons such as toluene, xylene, benzene and the like are particularly preferably used.

The content of the dispersion medium in the dispersion liquid of the present embodiment is preferably 10% by mass to 99% by mass, more preferably 10% by mass to 80% by mass, and further preferably 10% by mass to 70% by mass. It is below mass%.
In addition, the dispersion according to the present embodiment includes components other than those described above as necessary, for example, a dispersant, a dispersion aid, an antioxidant, a flow regulator, a thickener, a pH adjuster, a preservative, and the like. General additives may be included.

  In addition, in this specification, the dispersion liquid which concerns on this embodiment is distinguished from the composition which concerns on this embodiment which can form a sealing member by hardening | curing by containing a resin component. That is, the dispersion according to the present embodiment does not contain a resin component described later to the extent that a sealing member can be formed even if it is simply cured. More specifically, the mass ratio of the resin component to the metal oxide particles in the dispersion according to this embodiment is resin component: metal oxide particles and may be in the range of 0: 100 to 40:60. Preferably, it is in the range of 0: 100 to 20:80. The dispersion according to the present embodiment further preferably essentially does not contain a resin component described later, and particularly preferably does not completely contain a resin component described later.

  According to the present embodiment described above, since the D50 of the metal oxide particles is larger than 20 nm and not larger than 100 nm in the dispersion liquid, when the dispersion liquid is used as a sealing member material, Excellent balance of transparency. That is, the light scattering property in the sealing member can be improved by increasing the D50 of the metal oxide particles from the conventionally used range. In short, in the present embodiment, the present inventors have found and adopted a previously unknown relationship, that is, the relationship between the D50 range of the metal oxide particles, the light scattering property, and the transparency. And when such a dispersion liquid is included in a composition to be described later and used as a sealing material, the light extraction efficiency can be improved.

<2. Method for producing dispersion>
Next, a method for producing a dispersion according to this embodiment will be described. The dispersion can be produced, for example, by mixing the components of the dispersion and then dispersing the mixture by controlling the power of the disperser with a known disperser. Here, the dispersion according to the present embodiment uses a known disperser and does not give excessive energy so that the particle diameter of the metal oxide particles in the dispersion is almost uniform, and the minimum necessary amount. It is preferable to apply and disperse the energy.

As a known disperser, for example, a bead mill, a ball mill, a homogenizer, a disper, a stirrer and the like are preferably used.
Here, a method for producing a dispersion using a bead mill will be described in detail.

When producing the dispersion liquid of this embodiment with a bead mill, the dispersion speed is adjusted by setting the feather speed in the dispersion container to 4 m / s to 9 m / s and the cooling water temperature to 10 ° C. to 30 ° C. What is necessary is just to disperse | distribute on the conditions that the motive power displayed on a bead mill apparatus may be 1.0kW-2.5kW per kg of dispersion liquid.
By dispersing under such relatively mild conditions, D50 can be controlled to be larger than 20 nm and not larger than 100 nm. Further, the content of the free surface modifying material can be controlled to 53 mass% or less.
By the above method, the dispersion liquid of this embodiment can be obtained.

<3. Composition>
Next, the composition according to this embodiment will be described. The composition according to this embodiment is obtained by mixing the above-described dispersion and the resin component, and the above-described metal oxide particles having a refractive index of 1.7 or more and at least a part of the metal oxide. In addition to the surface modifying material attached to the product particles, a resin component, that is, a resin and / or a precursor thereof is included.

  The composition according to the present embodiment is cured as described later and used as a sealing member for a light emitting device. The composition according to the present embodiment can improve the light extraction efficiency when used in the sealing member by including the metal oxide particles that contribute to the above-described improvement in light scattering properties and transparency.

  In the composition of the present embodiment, the content of the metal oxide particles having a refractive index of 1.7 or more is preferably 5% by mass or more and 50% by mass or less from the viewpoint of obtaining a highly transparent composition. It is more preferably 5% by mass or more and 40% by mass or less, and further preferably 10% by mass or more and 35% by mass or less.

  Further, the content of the surface modifying material and the content of the free surface modifying material can be the same as the content in the dispersion according to the present embodiment.

  The resin component is a main component in the composition according to the present embodiment. The resin component is cured when the composition according to the present embodiment is used as a sealing material and seals the light emitting element, so that deterioration factors from the external environment such as moisture and oxygen reach the light emitting element. To prevent. In the present embodiment, the cured product obtained from the resin component is basically transparent and can transmit light emitted from the light emitting element.

  Such a resin component is not particularly limited as long as it can be used as a sealing material. For example, a resin such as a silicone resin or an epoxy resin can be used. In particular, a silicone resin is preferable.

  The silicone resin is not particularly limited as long as it is used as a sealing material, and for example, dimethyl silicone resin, methylphenyl silicone resin, phenyl silicone resin, organically modified silicone resin and the like can be used.

  In particular, when a surface modification material having at least one functional group selected from the group consisting of an alkenyl group, an H—Si group, and an alkoxy group is used as the surface modification material, and a silicone resin is used as the resin component The silicone resin preferably has at least one functional group selected from the group consisting of an H—Si group, an alkenyl group, and an alkoxy group. The reason will be described below.

  The alkenyl group of the surface modifying material is crosslinked by reacting with the H—Si group in the silicone resin. The H—Si group of the surface modifying material is crosslinked by reacting with the alkenyl group in the silicone resin. The alkoxy group of the surface modifying material is condensed with the alkoxy group in the silicone resin through hydrolysis. By such bonding, the silicone resin and the surface modifying material are integrated, so that the strength and denseness of the obtained sealing member can be improved.

  The structure of the resin component is not particularly limited, and may be a two-dimensional chain structure, a three-dimensional network structure, or a cage structure.

The resin component may be in the form of a polymer cured when used as a sealing member, and may be in a state before curing, that is, a precursor in the composition. Therefore, the resin component present in the composition may be a monomer, an oligomer, a prepolymer, or a polymer.
As the resin component, an addition reaction type, a condensation reaction type, or a radical polymerization reaction type may be used.

  The viscosity of the resin component at 25 ° C. measured in accordance with JIS Z 8803: 2011 is, for example, 10 mPa · s to 100,000 mPa · s, preferably 100 mPa · s to 10,000 mPa · s, more preferably It is 1,000 mPa · s or more and 7,000 mPa · s or less.

Moreover, although content of the resin component in the composition which concerns on this embodiment can be made into the remainder of another component, it is 10 mass% or more and 70 mass% or less, for example.
The mass ratio of the resin component and the metal oxide particles in the composition according to the present embodiment is preferably resin component: metal oxide particles and is in the range of 50:50 to 90:10, and 60:40 to More preferably, it is in the range of 80:20.

  The composition according to this embodiment may contain a dispersion medium derived from the dispersion according to this embodiment, or may be removed. That is, the dispersion medium derived from the dispersion may be completely removed, and may remain in the composition by about 1% by mass to 10% by mass with respect to the mass of the composition, and may be 2% by mass to 5% by mass. The following may remain.

  In addition, the composition according to this embodiment may contain phosphor particles as long as the object of the present invention is not impaired. The phosphor particles absorb light having a specific wavelength emitted from the light emitting element, and emit light having a predetermined wavelength. In other words, the phosphor particles can be used to convert the wavelength of light and thus adjust the color tone.

The phosphor particles are not particularly limited as long as they can be used in a light emitting device as described later, and can be appropriately selected and used so that the light emission color of the light emitting device becomes a desired color.
The content of the phosphor particles in the composition of the present embodiment can be appropriately adjusted and used so that desired brightness can be obtained.

  In addition, the composition of the present embodiment contains commonly used additives such as preservatives, polymerization initiators, polymerization inhibitors, curing catalysts, and light diffusing agents, as long as the object of the present invention is not impaired. May be. As the light diffusing agent, it is preferable to use silica particles having an average particle diameter of 1 to 30 μm.

  The viscosity of the composition according to this embodiment described above is, for example, 0.1 Pa · s or more and 100 Pa · s or less, preferably 0.5 Pa, under a measurement temperature of 25 ° C. and a shear rate of 1 (1 / s). · S to 50 Pa · s, more preferably 1.0 Pa · s to 20 Pa · s. When the viscosity of the composition is in the above range, the composition can be easily handled at the time of sealing the light emitting device, and the composition can be easily applied to the concave portion of the substrate carrying the light emitting device. And it becomes possible to form the sealing member which has convex shape or a flat surface shape, preventing mixing of the bubble to a sealing member at the time of light emitting element sealing.

  The composition according to this embodiment can be produced by mixing the dispersion according to this embodiment and the resin component. Moreover, you may remove the dispersion medium contained in the dispersion liquid with an evaporator etc. after mixing as needed.

  Since the composition according to this embodiment includes metal oxide particles having a refractive index of 1.7 or more having a D50 in a predetermined range in the dispersion, to which the surface modifying material is attached, and a resin component, the light scattering property is obtained. Excellent balance of transparency. Therefore, a sealing member having excellent light extraction efficiency can be formed.

<4. Sealing member>
The sealing member according to the present embodiment is a cured product of the composition according to the present embodiment. The sealing member according to this embodiment is usually used as a sealing member disposed on a light emitting element or a part thereof.
The thickness and shape of the sealing member according to the present embodiment can be appropriately adjusted according to a desired application and characteristics, and are not particularly limited.

  The sealing member according to the present embodiment can be manufactured by curing the composition according to the present embodiment as described above. The curing method of the composition can be selected according to the characteristics of the resin component in the composition according to this embodiment, and examples thereof include thermal curing and electron beam curing. More specifically, the sealing member of the present embodiment is obtained by curing the resin component in the composition of the present embodiment by an addition reaction or a polymerization reaction.

  The average dispersed particle size of the metal oxide particles in the sealing member is preferably 40 nm to 200 nm, more preferably 40 nm to 150 nm, and still more preferably 45 nm to 130 nm.

  When the average dispersed particle size is 40 nm or more, a sufficient light scattering effect can be obtained, and the light extraction efficiency of the light emitting device can be further improved. On the other hand, when the average dispersed particle size is 200 nm or less, the transmittance of the sealing member can be appropriately increased, and the light extraction efficiency of the light-emitting device can be further improved.

  The average dispersed particle size of the metal oxide particles in the sealing member is a number distribution-based average particle size (median diameter) measured by transmission electron microscope observation (TEM) of the sealing member. Further, the average dispersed particle size of the metal oxide particles in the sealing member in the present embodiment is a value measured and calculated based on the dispersed particle size of the metal oxide particles in the sealing member. The average dispersed particle diameter is measured and calculated based on the diameter of the metal oxide particles in a dispersed state regardless of whether the metal oxide particles are dispersed in a primary particle state or a secondary particle state. . Moreover, in this embodiment, the average particle diameter of the metal oxide particles in the sealing member may be measured as the average particle diameter of the metal oxide particles to which a surface modifying material described later is attached. In the sealing member, there may be metal oxide particles to which the surface modification material is attached and metal oxide particles to which the surface modification material is not attached. The average particle diameter is measured as a value in these mixed states.

  Since the sealing member which concerns on this embodiment is a hardening body of the composition which concerns on this embodiment, it is excellent in the balance of light-scattering property and transparency. Therefore, according to the present embodiment, a sealing member having excellent light extraction efficiency can be obtained.

<5. Light emitting device>
Next, the light emitting device according to this embodiment will be described. The light emitting device according to the present embodiment includes the sealing member described above and a light emitting element sealed by the sealing member.
Examples of the light emitting element include a light emitting diode (LED) and an organic light emitting diode (OLED). In particular, the sealing member according to the present embodiment is suitable for sealing a light emitting diode.

  Hereinafter, the light emitting device according to the present embodiment will be described with reference to an example in which the light emitting element is a light emitting diode on a chip, that is, an LED chip, and the light emitting device is an LED package. 1 to 4 are schematic views (cross-sectional views) each showing an example of a light emitting device according to an embodiment of the present invention. It should be noted that the size of each member in the figure is emphasized as appropriate for ease of explanation, and does not indicate actual dimensions and ratios between members. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

A light emitting device (LED package) 1 </ b> A shown in FIG. 1 covers a substrate 2 having a recess 21, a light emitting element (LED chip) 3 disposed on the bottom surface of the recess 21 of the substrate 2, and covers the light emitting element 3 in the recess 21. The sealing member 4A is sealed.
4A of sealing members are comprised by the sealing member which concerns on this embodiment mentioned above. Therefore, the sealing member 4A contains predetermined metal oxide particles and achieves both excellent light scattering properties and transparency. As a result, the light extraction efficiency in the light emitting device 1A is improved. Further, the phosphor particles 5 are dispersed in the sealing member 4A. The phosphor particles 5 convert the wavelength of at least a part of the light emitted from the light emitting element 3.

  The light emitting device 1B shown in FIG. 2 is different from the light emitting device 1A in that the sealing member 4B has two layers. That is, the sealing member 4B includes a first layer 41B that directly covers the light emitting element 3, and a second layer 43B that covers the first layer 41B. Both the first layer 41B and the second layer 43B are sealing members according to the present embodiment. The phosphor particles 5 are dispersed in the first layer 41B. On the other hand, the second layer 43 </ b> B does not include the phosphor particles 5. In the light emitting device 1B, since the first layer 41B and the second layer 43B constituting the sealing member 4B are sealing members according to the present embodiment having excellent light scattering properties and transparency, light extraction is performed. Efficiency has improved.

  The light emitting device 1C shown in FIG. 3 is also different from the light emitting device 1A in that the configuration of the sealing member 4C is different from that of the sealing member 4A. The sealing member 4C includes a first layer 41C that directly covers the light emitting element 3, and a second layer 43C that covers the first layer 41C. The first layer 41C is not a sealing member according to the present embodiment, but is a resin sealing member that does not include the metal oxide particles described above, and is configured of a resin that can be used for the sealing member. . Further, the phosphor particles 5 are dispersed in the first layer 41C. On the other hand, the second layer 43C is a sealing member according to this embodiment having excellent light scattering properties and transparency. In the light emitting device 1C, the light extraction efficiency is improved because the second layer 43C constituting the sealing member 4C is formed by the sealing member according to the present embodiment.

  In the light emitting device 1D shown in FIG. 4, the sealing member 4D further includes a first layer 41D that directly covers the light emitting element 3, a second layer 43D that covers the first layer 41D, and a second layer 43D. And a third layer 45D for covering. The first layer 41D and the second layer 43D are not sealing members according to this embodiment, but are resin sealing members that do not contain the metal oxide particles described above, and can be used for the sealing members. Etc. In addition, the phosphor particles 5 are dispersed in the second layer 43D. On the other hand, the third layer 45D is a sealing member according to this embodiment having excellent light scattering properties and transparency. In the light emitting device 1D, the third layer 45D constituting the sealing member 4D is formed by the sealing member according to this embodiment, so that the light extraction efficiency is improved.

  The light emitting device according to the present invention is not limited to the illustrated embodiment. For example, the light emitting device according to the present invention may not include phosphor particles in the sealing member. Moreover, the sealing member which concerns on this embodiment can exist in the arbitrary positions in a sealing member.

  As described above, the light emitting device according to the present embodiment is excellent in light extraction efficiency because the light emitting element is sealed by the sealing member of the present embodiment.

  In the light emitting device according to this embodiment, the light emitting element is sealed with the composition according to this embodiment as described above. Therefore, in one aspect, the present invention also relates to a method for manufacturing a light emitting device including a step of sealing a light emitting element using the composition according to the present embodiment. In the same aspect, the manufacturing method may include a step of obtaining the composition by mixing the dispersion according to the present embodiment and the resin component.

The light emitting device according to the present embodiment as described above can be used for, for example, a lighting fixture and a display device. Therefore, in one aspect, the present invention relates to a lighting fixture or a display device including the light emitting device according to the present embodiment.
Examples of lighting fixtures include general lighting devices such as room lights and outdoor lights, and illumination of switch units of electronic devices such as mobile phones and OA devices.
Since the lighting fixture according to the present embodiment includes the light emitting device according to the present embodiment, even if the same light emitting element is used, the emitted light flux is increased compared to the conventional case, and the surrounding environment may be brightened. it can.

Examples of the display device include a mobile phone, a portable information terminal, an electronic dictionary, a digital camera, a computer, a television, and peripheral devices thereof.
Since the display device according to the present embodiment includes the light emitting device according to the present embodiment, even if the same light emitting element is used, the emitted light flux becomes larger than that of the conventional case, and for example, a clearer and brighter display. It can be performed.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, the Example described below is an example of this invention to the last, Comprising: This invention is not limited.

[Example 1]
(Preparation of dispersion)
10 g of zirconium oxide particles (Sumitomo Osaka Cement Co., Ltd.) having an average primary particle size of 5 nm, 82 g of toluene, and 5 g of methoxy group-containing phenyl silicone resin (KR217, manufactured by Shin-Etsu Chemical Co., Ltd.) as a surface modifying material were added and mixed. This mixed liquid was set at a feather peripheral speed of 5.0 m / s and the cooling water temperature was set at 25 ° C., and subjected to a dispersion treatment for 6 hours by a bead mill to obtain a dispersion according to Example 1. The power per unit mass obtained by dividing the power displayed on the bead mill apparatus during the dispersion treatment by the amount of slurry was 1.4 kW / kg.

(Evaluation of particle size)
A part of the obtained dispersion was collected and diluted with toluene so that the solid content was 5% by mass.
D50 of this diluted dispersion was measured using a particle size distribution meter (manufactured by HORIBA, model number: SZ-100SP). As a result, D50 was 32 nm. The results are shown in Table 1. In addition, since the particle | grains contained in a dispersion liquid are fundamentally only the zirconium oxide particle to which the surface modification material adhered, it was thought that D50 measured was D50 of a zirconium oxide particle.

(Evaluation of free surface modification material content)
The liquid in 5 g of the obtained dispersion (total content of zirconium oxide particles and surface modifying material 0.78 g) was removed by an evaporator.
2 g of acetone was added to this concentrate and mixed to prepare a mixed solution.
The extract separated from the mixed solution was recovered by column chromatography using 10 cc of silica gel and 100 cc of a developing solvent (mixed hexane and acetone at a volume ratio of 2: 1). The recovered liquid was removed by an evaporator, and the remaining amount obtained was used as a free surface modifying material, and its mass was measured. The percentage of the value obtained by dividing the mass of the residue by the total mass (0.78 g) of the zirconium oxide particles and the surface modifying material contained in 5 g of the dispersion was calculated.
As a result, the content of the free surface modifying material was 40% by mass. The results are shown in Table 1.

(Production of composition)
10 g of the obtained dispersion liquid according to Example 1, methyl phenyl silicone resin as a silicone resin (OE-6520 manufactured by Toray Dow Corning Co., Ltd., refractive index 1.54, A liquid: B liquid mass mixing ratio = 1: 1 (resin 7.6 g) was mixed. Subsequently, the composition according to Example 1 containing surface-modified zirconium oxide particles and a methylphenyl silicone resin (OE-6520) was obtained by removing toluene from the mixed solution by drying under reduced pressure. The contents of zirconium oxide particles and toluene in the composition part were 11% by mass and 2% by mass, respectively.

(Evaluation of composition transmittance)
The transmittance of the composition according to Example 1 obtained was measured with a spectrophotometer V-770 (manufactured by JASCO Corporation) using an integrating sphere. A measurement sample having a thickness (optical path length) of 1 mm with the above composition sandwiched between thin-layer quartz cells was used.
As a result, the transmittance of the composition at a wavelength of 460 nm was 84%, and the transmittance at a wavelength of 600 nm was 90%. The results are shown in Table 1.

(Evaluation of viscosity of composition)
The viscosity of the composition according to Example 1 obtained was measured using a rheometer (Rheostress RS-6000, manufactured by HAAKE). The viscosity was measured at a temperature of 25 ° C. and a shear rate of 1.0 (1 / s).
As a result, the viscosity of the composition according to Example 1 was 10 Pa · s.

(Preparation of sealing member)
A SUS substrate was provided with a groove having a length of 20 mm, a width of 15 mm, and a depth of 5 mm, and the groove was coated with fluorine. The composition obtained in such a manner that the thickness after curing is 0.5 mm is poured into the groove of the mold, cured by heat treatment at 150 ° C. for 4 hours, and removed from the SUS substrate. A sealing member was obtained.

(Evaluation of transmittance of sealing member)
The transmittance of the obtained sealing member was measured with a spectrophotometer V-770 (manufactured by JASCO Corporation) using an integrating sphere.
As a result, the transmittance of the sealing member at a wavelength of 460 nm was 25%, and the transmittance at a wavelength of 600 nm was 70%. The results are shown in Table 1.

(Average dispersion particle diameter of metal oxide particles in the sealing member)
The average dispersed particle diameter of the zirconium oxide particles in the sealing member was measured with a field emission type transmission electron microscope (JEM-2100F, manufactured by JEOL Ltd.) using a sample obtained by slicing the sealing member in the thickness direction. . As a result, the average dispersed particle size of the metal oxide particles in the sealing member was 55 nm. The results are shown in Table 1.

(Production of LED package and evaluation of total luminous flux)
A blue light emitting diode (LED chip) was sealed with the composition according to Example 1 using a capacity-calculated digital control dispenser (trade name: MEASURING MASTER MPP-1, manufactured by Musashi Engineering Co., Ltd.). The composition was heat-treated at 150 ° C. for 2 hours to be cured, thereby producing a 3030 series (3.0 mm × 3.0 mm) LED package (light emitting device) according to Example 1.

The total luminous flux of this LED package was measured using a total luminous flux measurement system HM series (Otsuka Electronics Co., Ltd., sphere size 3000 mm).
As a result, the total luminous flux of the LED package according to Example 1 was 61.2 lm.

[Example 2]
A dispersion according to Example 2 was prepared in the same manner as in Example 1 except that zirconium oxide particles having an average primary particle size of 10 nm were used, the feather peripheral speed was set to 6.0 m / s, and the cooling water temperature was set to 20 ° C. Obtained. The power per unit mass, which was obtained by dividing the power displayed in the bead mill apparatus during the dispersion treatment by the amount of slurry, was 2.3 kW / kg.

  In the same manner as in Example 1, the particle size and the content of the free surface modifying material were measured. As a result, D50 was 48 nm. Further, the content of the free surface modifying material was 45% by mass. The results are shown in Table 1.

  Instead of using the dispersion according to Example 1, a composition, a sealing member, and an LED package according to Example 2 were obtained in the same manner as in Example 1 except that the dispersion according to Example 2 was used.

As in Example 1, the transmittance of the composition according to Example 2 was measured. As a result, the transmittance at a wavelength of 460 nm was 58%, and the transmittance at a wavelength of 600 nm was 79%.
As a result of measuring the viscosity of the composition in the same manner as in Example 1, the viscosity of the composition according to Example 2 was 7 Pa · s.
Further, as in Example 1, the transmittance of the sealing member according to Example 2 was measured. As a result, the transmittance at a wavelength of 460 nm was 15%, and the transmittance at a wavelength of 600 nm was 52%.
Further, as in Example 1, the average dispersed particle size of the metal oxide particles in the sealing member according to Example 2 was measured and found to be 85 nm.
Furthermore, as a result of measuring the total luminous flux in the same manner as in Example 1 for the LED package according to Example 2, the total luminous flux was 61.3 lm. The results are shown in Table 1.

[Example 3]
The dispersion according to Example 3 was prepared in the same manner as in Example 1 except that zirconium oxide particles having an average primary particle size of 20 nm were used, the feather peripheral speed was set to 6.0 m / s, and the cooling water temperature was set to 15 ° C. Obtained. The power per unit mass obtained by dividing the power displayed in the bead mill apparatus during the dispersion treatment by the amount of slurry was 2.2 kW / kg.
In the same manner as in Example 1, the particle size and the content of the free surface modifying material were measured. As a result, D50 was 57 nm and the content of the free surface modifying material was 50% by mass. The results are shown in Table 1.

Instead of using the dispersion according to Example 1, a composition, a sealing member, and an LED package according to Example 3 were obtained in the same manner as in Example 1 except that the dispersion according to Example 3 was used.
As in Example 1, the transmittance of the composition according to Example 3 was measured. As a result, the transmittance at a wavelength of 460 nm was 41%, and the transmittance at a wavelength of 600 nm was 68%.
As a result of measuring the viscosity of the composition in the same manner as in Example 1, the viscosity of the composition according to Example 3 was 4 Pa · s.
Further, as in Example 1, the transmittance of the sealing member according to Example 3 was measured. As a result, the transmittance at a wavelength of 460 nm was 10%, and the transmittance at a wavelength of 600 nm was 41%.
Further, as in Example 1, the average dispersed particle size of the metal oxide particles in the sealing member according to Example 3 was measured and found to be 128 nm.
Moreover, as a result of measuring the total luminous flux in the same manner as in Example 1 for the LED package according to Example 3, the total luminous flux was 61.7 lm. The results are shown in Table 1.

[Example 4]
A dispersion according to Example 4 was prepared in the same manner as in Example 1 except that titanium oxide particles having an average primary particle size of 15 nm were used, the feather peripheral speed was set to 6.0 m / s, and the cooling water temperature was set to 15 ° C. Obtained. The power per unit mass obtained by dividing the power displayed on the bead mill apparatus during the dispersion treatment by the amount of slurry was 2.1 kW / kg.
In the same manner as in Example 1, the particle size and the content of the free surface modifying material were measured. As a result, D50 was 51 nm and the content of the free surface modifying material was 42% by mass. The results are shown in Table 1.

  Instead of using the dispersion according to Example 1, a composition, a sealing member and an LED package according to Example 4 were obtained in the same manner as in Example 1 except that the dispersion according to Example 4 was used.

As in Example 1, the transmittance of the composition according to Example 4 was measured. As a result, the transmittance at a wavelength of 460 nm was 38%, and the transmittance at a wavelength of 600 nm was 61%.
As a result of measuring the viscosity of the composition in the same manner as in Example 1, the viscosity of the composition according to Example 4 was 9 Pa · s.
As in Example 1, the transmittance of the sealing member according to Example 4 was measured. As a result, the transmittance at a wavelength of 460 nm was 19%, and the transmittance at a wavelength of 600 nm was 35%.
Further, as in Example 1, the average dispersed particle size of the metal oxide particles in the sealing member according to Example 4 was measured and found to be 110 nm.
Furthermore, as a result of measuring the total luminous flux in the same manner as in Example 1 for the LED package according to Example 4, the total luminous flux was 61.4 lm. The results are shown in Table 1.

[Example 5]
Example 5 was performed in the same manner as in Example 1 except that zirconium oxide particles having an average primary particle diameter of 12 nm were used, 3 g was used instead of 5 g of the methoxy group-containing phenyl silicone resin, and the cooling water temperature was set to 20 ° C. Such a dispersion was obtained. The power per unit mass obtained by dividing the power displayed on the bead mill apparatus during the dispersion treatment by the amount of slurry was 1.6 kW / kg.
In the same manner as in Example 1, the particle size and the content of the free surface modifying material were measured. As a result, D50 was 53 nm and the content of the free surface modifying material was 17% by mass. The results are shown in Table 1.

  Instead of using the dispersion according to Example 1, a composition, a sealing member, and an LED package according to Example 5 were obtained in the same manner as in Example 1 except that the dispersion according to Example 5 was used.

As in Example 1, the transmittance of the composition according to Example 5 was measured. As a result, the transmittance at a wavelength of 460 nm was 54%, and the transmittance at a wavelength of 600 nm was 73%.
As a result of measuring the viscosity of the composition in the same manner as in Example 1, the viscosity of the composition according to Example 5 was 175 Pa · s.
As in Example 1, the transmittance of the sealing member according to Example 5 was measured. As a result, the transmittance at a wavelength of 460 nm was 13%, and the transmittance at a wavelength of 600 nm was 45%.
Further, as in Example 1, the average dispersed particle size of the metal oxide particles in the sealing member according to Example 5 was measured and found to be 98 nm.
Furthermore, as a result of measuring the total luminous flux in the same manner as in Example 1 for the LED package according to Example 5, the total luminous flux was 61.3 lm. The results are shown in Table 1.

[Comparative Example 1]
A dispersion according to Comparative Example 1 was prepared in the same manner as in Example 1 except that zirconium oxide particles having an average primary particle size of 33 nm were used, the feather peripheral speed was set to 12.0 m / s, and the cooling water temperature was set to 40 ° C. Obtained. The power per unit mass obtained by dividing the power displayed in the bead mill apparatus during the dispersion treatment by the amount of slurry was 12.9 kW / kg.
In the same manner as in Example 1, the particle size and the content of the free surface modifying material were measured. As a result, D50 was 125 nm and the content of the free surface modifying material was 65% by mass. The results are shown in Table 1.

Instead of using the dispersion according to Example 1, a composition, a sealing member and an LED package according to Comparative Example 1 were obtained in the same manner as in Example 1 except that the dispersion according to Comparative Example 1 was used.
As in Example 1, the transmittance of the composition according to Comparative Example 1 was measured. As a result, the transmittance at a wavelength of 460 nm was 18%, and the transmittance at a wavelength of 600 nm was 29%.
As a result of measuring the viscosity of the composition in the same manner as in Example 1, the viscosity of the composition according to Comparative Example 1 was 52 Pa · s.
Further, as in Example 1, the transmittance of the sealing member according to Comparative Example 1 was measured. As a result, the transmittance at a wavelength of 460 nm was 3%, and the transmittance at a wavelength of 600 nm was 21%.
Further, as in Example 1, the average dispersed particle size of the metal oxide particles in the sealing member according to Comparative Example 1 was measured and found to be 160 nm.
Further, the LED package according to Comparative Example 1 was measured in the same manner as in Example 1. As a result, the total luminous flux was 59.7 lm. The results are shown in Table 1.

[Comparative Example 2]
A dispersion according to Comparative Example 2 was prepared in the same manner as in Example 1 except that zirconium oxide particles having an average primary particle diameter of 5 nm were used, the feather peripheral speed was set to 6.0 m / s, and the cooling water temperature was set to 25 ° C. Obtained. The power per unit mass, which was obtained by dividing the power displayed on the bead mill apparatus during the dispersion treatment by the amount of slurry, was 2.6 kW / kg.
In the same manner as in Example 1, the particle size and the content of the free surface modifying material were measured. As a result, D50 was 13 nm and the content of the free surface modifying material was 41% by mass. The results are shown in Table 1.

  Instead of using the dispersion according to Example 1, a composition, a sealing member, and an LED package according to Comparative Example 2 were obtained in the same manner as in Example 1 except that the dispersion according to Comparative Example 2 was used.

As in Example 1, the transmittance of the composition according to Comparative Example 2 was measured. As a result, the transmittance at a wavelength of 460 nm was 89%, and the transmittance at a wavelength of 600 nm was 93%.
As a result of measuring the viscosity of the composition in the same manner as in Example 1, the viscosity of the composition according to Comparative Example 2 was 23 Pa · s.
Further, as in Example 1, the transmittance of the sealing member according to Comparative Example 2 was measured. As a result, the transmittance at a wavelength of 460 nm was 34%, and the transmittance at a wavelength of 600 nm was 75%.
Further, as in Example 1, the average dispersed particle size of the metal oxide particles in the sealing member according to Comparative Example 2 was measured and found to be 21 nm.
Furthermore, the LED package according to Comparative Example 2 was measured in the same manner as in Example 1. As a result, the total luminous flux was 60.1 lm. The results are shown in Table 1.

  From the results of Examples 1 to 5 and Comparative Examples 1 to 2, a light emitting device having excellent light extraction efficiency can be obtained by using a dispersion liquid in which D50 of the metal oxide particles is larger than 20 nm and not larger than 100 nm. Was confirmed.

  Furthermore, the compositions according to Examples 1 to 4 having a relatively large content of free surface modifier were significantly smaller in viscosity than the composition according to Example 5 having a small content of free surface modifier. . Such compositions according to Examples 1 to 4 are easy to handle when the light emitting device is sealed.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

1A, 1B, 1C, 1D Light emitting device 2 Substrate 21 Recess 3 Light emitting element 4A, 4B, 4C, 4D Sealing member 41B, 41C, 41D First layer 43B, 43C, 43D Second layer 45D Third layer 5 Phosphor particles

Claims (7)

Metal oxide particles having a refractive index of 1.7 or more, and a surface modifying material having at least a part attached to the metal oxide particles,
A dispersion liquid for sealing a light emitting device, wherein the particle diameter D50 of the metal oxide particles when the cumulative percentage of the scattering intensity distribution obtained by the dynamic light scattering method is 50% is larger than 20 nm and not larger than 100 nm. .   The dispersion according to claim 1, wherein the surface modifying material has at least one functional group selected from the group consisting of an alkenyl group, an H-Si group, and an alkoxy group.   The composition for sealing the light emitting element obtained by mixing the dispersion liquid of Claim 1 or 2, and a resin component.   The sealing member which is a hardened | cured material of the composition of Claim 3.   A light emitting device comprising the sealing member according to claim 4 and a light emitting element sealed by the sealing member.   A lighting fixture comprising the light-emitting device according to claim 5. A display device comprising the light emitting device according to claim 5.

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