JP7215198B2 - Dispersion liquid, composition, sealing member, light-emitting device, lighting equipment, display device, and method for producing dispersion liquid - Google Patents

Description

TECHNICAL FIELD The present invention relates to a dispersion, a composition, a sealing member, a light-emitting device, lighting equipment, a display device, and a method for producing a dispersion.

Light emitting diodes (LEDs) are widely used as light sources that have advantages such as small size, long life, and low voltage drive. An LED chip in an LED package is generally sealed with a resin-containing sealing material in order to prevent contact with deterioration factors present in the external environment, such as oxygen and moisture. Therefore, the light emitted from the LED chip is transmitted through the sealing material and emitted to the outside. 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, and a silicone resin. (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 dispersion can improve the refractive index of the encapsulating material, and when the light emitted from the LED chip enters the encapsulating material, the interface between the LED chip and the encapsulating material has can suppress total reflection of light. As a result of these, the light extraction efficiency can be improved. Patent Document 1 also discloses modifying inorganic oxide particles with a surface modifying material.

JP 2007-299981 A

However, there is a demand for further improvement in the brightness of light from light emitting devices.

The present invention has been made to solve the above problems, and includes a dispersion, a composition, and an encapsulant formed using the composition, which can improve the light brightness of a light-emitting device. An object of the present invention is to provide a member, a light-emitting device having this sealing member, a lighting fixture and a display device having this light-emitting device, and a method for producing a dispersion.

In order to solve the above-mentioned problems, according to one aspect of the present invention, inorganic oxide particles, a surface-modifying material attached to the inorganic oxide particles, a dispersion medium, and water are contained,
the dispersion medium comprises an alcoholic solvent and a hydrophobic solvent,
A dispersion is provided in which the water content is 10 ppm or more and 2000 ppm or less.
The dispersion may further contain a catalyst.

In order to solve the above problems, according to another aspect of the present invention, there is provided a composition for encapsulating a light-emitting element obtained by mixing a dispersion liquid and a resin component.
Moreover, in order to solve the above problems, according to another aspect of the present invention, there is provided a sealing member that is a cured product of the above composition.

Further, in order to solve the above problems, according to another aspect of the present invention, there is provided a light-emitting device including the sealing member and a light-emitting element sealed with the sealing member.
Moreover, in order to solve the above problems, according to another aspect of the present invention, there is provided a lighting fixture or a display device including the light emitting device.

In order to solve the above problems, according to another aspect of the present invention, a step of mixing a surface modifying material, an alcoholic solvent and water to obtain a mixed solution;
A method for producing a dispersion is provided, comprising: mixing the mixture, inorganic oxide particles, and a hydrophobic solvent to obtain a dispersion in which the inorganic oxide particles are dispersed.

As described above, according to the present invention, a dispersion liquid, a composition, a sealing member formed using the composition, and a light emitting device having the sealing member, which can improve the brightness of light of a light emitting device, It is possible to provide a lighting fixture and a display device equipped with this light-emitting device, and a method for producing a dispersion.

It is a schematic diagram showing an example of a light-emitting device according to an embodiment of the present invention.

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

<1. Dispersion>
The dispersion according to this embodiment contains inorganic oxide particles, a surface-modifying material attached to the inorganic oxide particles, a dispersion medium, and water.

In this embodiment, the dispersion medium contains an alcoholic solvent and a hydrophobic solvent, and has a water content of 10 ppm or more and 2000 ppm or less.

As described above, the dispersion liquid according to the present embodiment is mixed with the resin component to obtain a composition, and the composition is used to seal the light-emitting element, thereby improving the light brightness of the obtained light-emitting device.

More specifically, the surface-modifying material adheres to the surfaces of the inorganic oxide particles, thereby contributing to improving the dispersion stability of the inorganic oxide particles. A small amount of water present in the dispersion promotes hydrolysis of the surface-modifying material, and as a result, promotes adhesion of the surface-modifying material to the surfaces of the inorganic oxide particles. On the other hand, since the resin component mixed when manufacturing the composition described below is generally hydrophobic, it is desirable that the dispersion contains a hydrophobic solvent as a dispersion medium. However, when the dispersion contains a hydrophobic solvent as a dispersion medium, water is difficult to mix with the hydrophobic solvent, so the effect of promoting hydrolysis of the surface-modifying material is not sufficiently exhibited.

In contrast, in the present embodiment, the dispersion contains an alcoholic solvent in addition to the hydrophobic solvent as the dispersion medium. Alcoholic solvents are miscible with any amount of water and miscible with hydrophobic solvents. Therefore, by including the alcohol-based solvent in the dispersion liquid, water can be miscible with the hydrophobic solvent, and the effect of promoting the hydrolysis of the surface-modifying material can be sufficiently exhibited. As a result, the surface-modifying material easily adheres to the surfaces of the inorganic oxide particles, and the dispersion stability of the inorganic oxide particles in the dispersion is improved. In addition, when the dispersion is produced, the surface-modifying material easily adheres to the surfaces of the inorganic oxide particles, so that the dispersion time for dispersing the inorganic oxide particles can be shortened. Degradation of the surface-modifying material can be prevented, and coloring of the resulting dispersion or composition can be suppressed. As a result, by mixing the dispersion liquid according to the present embodiment with a resin component to obtain a composition, and sealing the light emitting element using the composition, the light brightness of the obtained light emitting device is improved.

Generally, when a hydrophobic solvent is used as a dispersion medium, water is a component that should be excluded as an impurity. The present inventors have found that by using such water together with an alcoholic solvent, a sufficient hydrolysis effect of the surface-modifying material can be obtained while reducing the water content.
Each component contained in the dispersion will be described below.

(1.1 Inorganic oxide particles)
The inorganic oxide particles scatter light emitted from the light emitting element in the sealing member described later. Moreover, the inorganic oxide particles improve the refractive index of the sealing member depending on the type thereof. As a result, the inorganic oxide particles contribute to improving the brightness of the light of the light-emitting device.

The inorganic oxide particles contained in the dispersion according to this embodiment are not particularly limited. In the present embodiment, the inorganic oxide particles include, for example, zirconium oxide particles, titanium oxide particles, silica particles, zinc oxide particles, iron oxide particles, copper oxide particles, tin oxide particles, cerium oxide particles, tantalum oxide particles, oxide Niobium particles, tungsten oxide particles, europium oxide particles, yttrium oxide particles, molybdenum oxide particles, indium oxide particles, antimony oxide particles, germanium oxide particles, lead oxide particles, bismuth oxide particles and hafnium oxide particles and potassium titanate particles, titanium Barium oxide particles, strontium titanate particles, potassium niobate particles, lithium niobate particles, calcium tungstate particles, yttria-stabilized zirconia particles, alumina-stabilized zirconia particles, silica-stabilized zirconia particles, calcia-stabilized zirconia particles, magnesia-stabilized zirconia stabilized particles, scandia stabilized zirconia particles, hafnia stabilized zirconia particles, ytterbia stabilized zirconia particles, ceria stabilized zirconia particles, india stabilized zirconia particles, strontium stabilized zirconia particles, samarium oxide stabilized zirconia particles, gadolinium oxide stabilized Inorganic oxide particles containing at least one selected from the group consisting of zirconia particles, antimony-added tin oxide particles, and indium-added tin oxide particles are preferably used.

Among the above, from the viewpoint of improving transparency and compatibility (affinity) with the sealing resin (resin component), the dispersion liquid contains at least one selected from the group consisting of zirconium oxide particles, titanium oxide particles and silica particles. It is preferred that one species is included.

Moreover, the inorganic oxide particles preferably have a refractive index of 1.7 or more from the viewpoint of improving the refractive index of the sealing member. Examples of such inorganic oxide particles include inorganic oxide particles other than the silica particles described above.

The inorganic oxide particles are more preferably zirconium oxide particles and/or titanium oxide particles, and particularly preferably zirconium oxide particles.

The inorganic oxide particles may be dispersed as primary particles in the dispersion liquid, or may be dispersed as secondary particles in which the primary particles are aggregated. Inorganic oxide particles are usually dispersed as secondary particles.

The average dispersed particle diameter of the inorganic oxide particles in the dispersion is not particularly limited, but is, for example, 10 nm or more and 200 nm or less, preferably 20 nm or more and 150 nm or less, and more preferably 30 nm or more and 100 nm or less. When the average dispersed particle diameter of the inorganic oxide particles is 10 nm or more, the light brightness of the light-emitting device manufactured using this dispersion liquid, which will be described later, is improved. In addition, when the average dispersed particle diameter of the inorganic oxide particles is 200 nm or less, it is possible to suppress a decrease in the light transmittance of the dispersion, the composition produced using the same, and the sealing member, which will be described later. . As a result, the brightness of light from the light emitting device is improved.

The average dispersed particle diameter of the inorganic oxide particles can be the particle diameter D50 of the inorganic oxide particles when the cumulative percentage of the scattering intensity distribution obtained by the dynamic light scattering method is 50%. It can be measured with a scattering type particle size distribution analyzer (eg, manufactured by HORIBA, model number: SZ-100SP). The measurement can be performed using a quartz cell with an optical path length of 10 mm×10 mm for a dispersion liquid adjusted to have a solid content of 5% by mass. As used herein, the term "solid content" refers to the residue left after removal of volatile components in the dispersion. For example, 1.2 g of the dispersion liquid is placed in a magnetic crucible and heated on a hot plate at 150 ° C. for 1 hour. be able to.

In addition, the average dispersed particle diameter of the inorganic oxide particles is based on the diameter of the dispersed inorganic particles, regardless of whether the inorganic oxide particles are dispersed in the form of primary particles or secondary particles. Measured and calculated. Further, in the present embodiment, the average dispersed particle size of the inorganic oxide particles may be measured as the average dispersed particle size of the inorganic oxide particles to which the surface modifying material is adhered. Since inorganic oxide particles to which the surface-modifying material is attached and inorganic oxide particles to which the surface-modifying material is not attached may exist in the dispersion liquid, the average dispersed particle diameter of the inorganic oxide particles is usually It is measured as a value in these mixed states.

The average primary particle size of the inorganic oxide particles is, for example, 3 nm or more and 100 nm or less, preferably 4 nm or more and 80 nm or less, more preferably 10 nm or more and 60 nm or less. When the average primary particle size is within the above range, deterioration in transparency of the sealing member can be suppressed. As a result, the brightness of light from the light emitting device can be further improved.

The average primary particle size of the inorganic oxide particles can be measured, for example, by observation with a transmission electron microscope. First, a collodion film obtained by extracting inorganic oxide particles from a dispersion liquid is observed with a transmission electron microscope to obtain a transmission electron microscope image. Next, a predetermined number, for example 100, of the inorganic oxide particles in the transmission electron microscope image are selected. Then, the longest linear segment (maximum length) of each of these inorganic oxide particles is measured, and these measured values are arithmetically averaged.

Here, when the inorganic oxide particles are agglomerated, the agglomerated particle size of the agglomerates is not measured. A predetermined number of maximum major diameters of the particles (primary particles) of the inorganic oxide particles forming the aggregates are measured to determine the average primary particle diameter.

Moreover, the content of the inorganic oxide particles in the dispersion is not particularly limited as long as it can be mixed with the resin component described later. The content of the inorganic oxide particles in the dispersion liquid is, for example, 1% by mass or more and 70% by mass or less, preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 30% by mass or less.

As a result, it is possible to prevent the viscosity of the dispersion liquid from becoming excessively large, so that mixing with the resin component, which will be described later, is facilitated. In addition, it is possible to prevent the amount of the solvent (dispersion medium) from becoming excessive after mixing with the resin component, which facilitates the removal of the solvent.

A surface-modifying material described below is attached to the surfaces of the inorganic oxide particles described above. As a result, the inorganic oxide particles are stably dispersed in the dispersion liquid and the dispersion liquid produced using the dispersion liquid.

(1.2 Surface modification material)
The dispersion according to this embodiment contains a surface-modifying material. At least a portion of the surface-modifying material adheres to the surfaces of the inorganic oxide particles in the dispersion liquid to prevent aggregation of the inorganic oxide particles. Furthermore, it improves the compatibility with the resin component.

Here, the expression that the surface-modifying material "adheres" to the inorganic oxide particles means that the surface-modifying material contacts or bonds to the inorganic oxide particles through interaction or reaction therebetween. Contacting includes, for example, physical adsorption. Further, the bond includes an ionic bond, a hydrogen bond, a covalent bond, and the like.

Such a surface-modifying material is not particularly limited as long as it can adhere to the inorganic oxide particles and has good compatibility with the resin component as described later.
As such a surface-modifying material, a surface-modifying material having at least one functional group selected from the group of reactive functional groups such as alkenyl groups, H—Si groups, and alkoxy groups is preferably used. In particular, a surface modification material having an alkoxy group is preferably used in this embodiment because it can be hydrolyzed by reacting with water.

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. be done.
Examples of the alkoxy group include linear or branched alkoxy groups having 1 to 5 carbon atoms, and specific examples include methoxy, ethoxy, n-propoxy, isopropoxy and butoxy groups.

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

Examples of silane compounds include vinyltrimethoxysilane, isobutyltrimethoxysilane, phenyltrimethoxysilane, methacryloxypropyltrimethoxysilane, acryloxypropyltrimethoxysilane, dimethylchlorosilane, methyldichlorosilane, diethylchlorosilane, ethyldichlorosilane, Methylphenylchlorosilane, diphenylchlorosilane, phenyldichlorosilane, trimethoxysilane, dimethoxysilane, monomethoxysilane, triethoxysilane, diethoxymonomethylsilane, monoethoxydimethylsilane, methylphenyldimethoxysilane, diphenylmonomethoxysilane, methylphenyldiethoxy silane, diphenylmonoethoxysilane, and the like.

Examples of silicone compounds include methylhydrogensilicone, methylphenylhydrogensilicone, diphenylhydrogensilicone, alkoxy-terminated phenylsilicone, methylphenylsilicone, alkoxy-terminated methylphenylsilicone, alkoxy group-containing methylphenyl silicone, and alkoxy group-containing Examples include dimethyl silicone, alkoxy single-ended trimethyl single-ended (methyl group single-ended) dimethyl silicone, and alkoxy group-containing phenyl silicone.
The silicone compound may be an oligomer or a resin (polymer).
Examples of carbon-carbon unsaturated bond-containing fatty acids include methacrylic acid and acrylic acid.

Among these surface-modifying materials, vinyltrimethoxysilane, isobutyltrimethoxysilane, phenyltrimethoxysilane, and phenyltrimethoxysilane are preferred from the standpoint of suppressing aggregation of inorganic oxide particles in a dispersion and making it easier to obtain a highly transparent sealing member. The group of silane, alkoxy single-ended vinyl-single-ended methylphenyl silicone, alkoxy single-ended vinyl-single-ended phenyl silicone, alkoxy single-ended vinyl-single-single-ended dimethyl silicone, alkoxy one-single-ended trimethyl one-single-ended dimethyl silicone, methoxy group-containing phenyl silicone and methylphenyl silicone It is preferable to use one or two or more selected from.

The amount of the surface-modifying material relative to the inorganic oxide particles is not particularly limited, and is, for example, 10% by mass or more and 200% by mass or less, preferably 30% by mass or more and 150% by mass or less, and more preferably 50% by mass or more. It is 120% by mass or less. When the amount of the surface-modifying material is within the range described above, the dispersibility of the inorganic oxide particles can be sufficiently improved while reducing the amount of liberated surface-modifying material.

In the dispersion, the total content of the surface-modifying material and the inorganic oxide particles is preferably 2% by mass or more and 80% by mass or less, more preferably 10% by mass or more and 60% by mass or less, and still more preferably 20% by mass or more. It is 50% by mass or less. As a result, it is possible to prevent the viscosity of the dispersion from becoming excessively large, so that mixing with the resin component is facilitated. In addition, it is possible to prevent the amount of the solvent (dispersion medium) from becoming excessive after mixing with the resin component, which facilitates the removal of the solvent.

In addition, in the dispersion according to the present embodiment, the content of the surface-modifying material that is not attached to the inorganic oxide particles, i.e., the content of the surface-modifying material that is free in the dispersion (free surface-modifying material) is is preferably 50% by mass or less with respect to the total content of

The content of the free surface-modifying material may be, for example, 0% by weight or 0% by weight or more, 10% by weight or more, 20% by weight or more, or 30% by weight or more.

In this specification, the term "free surface-modifying material" means a surface-modifying material that is not attached to the inorganic oxide particles. The content of the free surface-modifying material is, for example, a value calculated by the following method, 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 by an evaporator to obtain a concentrate. Next, 2 g of acetone is added to this concentrate and mixed to prepare a mixed solution.
The extract separated from the mixture is collected by column chromatography using a column filled with 10 g of silica gel and 100 cc of developing solvent (hexane and acetone mixed at a volume ratio of 2:1). The liquid in this extract is removed by an evaporator, and the resulting residue is assumed to be a free surface-modifying material, and its mass is measured. The mass of the residue is divided by the total mass of the inorganic oxide particles and the surface-modifying material contained in 5 g of the dispersion liquid of the present embodiment, and the resulting percentage is defined as the content of the free surface-modifying material.

(1.3 Water)
Moreover, the dispersion according to the present embodiment contains water. The content of water in the dispersion is 10 ppm or more and 2000 ppm or less. As a result, the minute amount of water present in the dispersion accelerates the hydrolysis of the surface modifying material, and as a result, the adhesion of the surface modifying material to the surfaces of the inorganic oxide particles is promoted. And while the dispersibility of the inorganic oxide particles is maintained, free surface modification material is reduced.

When the content of water contained in the dispersion exceeds 2000 ppm, excessive water is contained in the dispersion, which makes it difficult to mix the dispersion medium and water, and reduces the transparency of the dispersion. Furthermore, as a result of containing an excessive amount of water, the inorganic oxide particles in the dispersion liquid tend to agglomerate, and the dispersibility of the inorganic oxide particles rather decreases. On the other hand, when the content of water contained in the dispersion liquid is less than 10 ppm, hydrolysis of the surface-modifying material is insufficient, resulting in insufficient adhesion of the surface-modifying material to the surfaces of the inorganic oxide particles. , free surface modification material increases.

The content of water contained in the dispersion liquid may be within the range described above, but it is preferably 50 ppm or more and 1500 ppm or less, more preferably 100 ppm or more and 1000 ppm or less.

(1.4 dispersion medium)
Moreover, the dispersion liquid according to the present embodiment contains a dispersion medium for dispersing the inorganic oxide particles. And in this embodiment, the dispersion medium includes an alcoholic solvent and a hydrophobic solvent. The hydrophobic solvent has excellent dispersibility of the inorganic oxide particles and excellent compatibility with the resin component described later. Therefore, even when the dispersion liquid and the resin component are mixed to produce a composition, the dispersed state of the inorganic oxide particles is likely to be maintained. On the other hand, the alcohol-based solvent promotes the mixing of water and the hydrophobic solvent described above, and promotes hydrolysis of the surface-modifying material by water.

Examples of alcohol solvents include branched or linear alcohol compounds having 1 to 4 carbon atoms, and these can be used alone or in combination of two or more. The alcohol compound contained in the alcohol solvent may be any of primary, secondary and tertiary alcohols. The alcohol compound contained in the alcohol solvent may be any of monohydric, dihydric and trihydric alcohols. More specifically, alcohol solvents include, for example, methanol, ethanol, 1-propanol, isopropyl alcohol, 1-butyl alcohol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, methanediol, 1,2-ethane. Diol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-butene-1, 4-diol, 1,4-butynediol, glycerin, diethylene glycol, 3-methoxy-1,2-propanediol and the like.

In addition, from the viewpoint of excellent affinity with both water and hydrophobic solvents and promotion of their mixing, the number of carbon atoms in the alcohol compound constituting the alcohol-based solvent is preferably 1 or more and 3 or less, more preferably 1 or more and 2 or less. It is below.
Among those mentioned above, methanol and ethanol, particularly methanol, can be preferably used because they can sufficiently exhibit the effects of the alcohol solvent.

The content of the alcohol-based solvent in the dispersion is not particularly limited, but is, for example, 1 ppm or more and 1000 ppm or less, preferably 10 ppm or more and 500 ppm or less. If the content of the alcohol-based solvent in the dispersion exceeds 1000 ppm, it may become difficult to mix the dispersion and the resin component depending on the type of the resin component mixed with the dispersion. Further, when the content of the alcohol-based solvent in the dispersion liquid is less than 1 ppm, it may be difficult to sufficiently mix water with the hydrophobic solvent, depending on the type of the hydrophobic solvent.

Examples of hydrophobic solvents include aromatics, saturated hydrocarbons, unsaturated hydrocarbons, and the like. One of these solvents may be used, or two or more thereof may be used. Among those mentioned above, aromatics, particularly aromatic hydrocarbons, are preferred. Aromatics have excellent compatibility with silicone resins, which will be described later, and contribute to improving the viscosity characteristics of the resulting composition and improving the quality (transparency, shape, etc.) of the formed sealing member. On the other hand, aromatics, especially aromatic hydrocarbons, are hydrophobic solvents. Water is treated as an ingredient to be eliminated as much as possible, as it is expected to degrade the quality of the sealing member as a result. In the present embodiment, even when aromatics are used, the above-described trace amount of water is taken into the surface of the inorganic oxide particles via the alcohol solvent, and the dispersibility of the inorganic oxide particles in the dispersion liquid is improved. can be maintained.

Such aromatic hydrocarbons include, for example, benzene, toluene, ethylbenzene, 1-phenylpropane, isopropylbenzene, n-butylbenzene, tert-butylbenzene, sec-butylbenzene, o-, m- or p-xylene, 2-, 3- or 4-ethyltoluene, and the like. These aromatic hydrocarbons may be used individually by 1 type, and may be used in combination of 2 or more type.

Among the above, from the viewpoint of the stability of the dispersion and ease of handling such as removal of the dispersion medium during the production of the composition described later, the dispersion medium may be toluene, o-, m- or p-xylene, One or more selected from the group consisting of benzene is particularly preferably used.

The content of the hydrophobic solvent in the dispersion is, for example, 60% by mass or more and 90% by mass in order to simultaneously ensure high miscibility with the inorganic oxide particle surface having hydrophilicity and the resin component having hydrophobicity described later. Below, it is preferably 65% by mass or more and 86% by mass or less, more preferably 70% by mass or more and 83% by mass or less.
This makes it easier to mix the dispersion and the resin component described later, while ensuring the mixing of the water and the hydrophobic solvent.

The content of the dispersion medium in the dispersion liquid of the present embodiment is preferably 10% by mass or more and 98% by mass or less, more preferably 20% by mass or more and 90% by mass or less, and still more preferably 30% by mass or more and 80% by mass. % by mass or less.

(1.5 catalyst)
The dispersion according to this embodiment may contain a catalyst. Acids or bases, for example, can be used as catalysts.
Acid catalyzes the hydrolysis reaction of the surface modification material in the dispersion. On the other hand, the base catalyzes the condensation reaction between the hydrolyzed surface modifier and the silanol groups on the particle surface. This makes it easier for the surface-modifying material to adhere to the inorganic oxide particles, improving the dispersion stability of the inorganic oxide particles. The catalyst makes it easier for the surface-modifying material to adhere to the inorganic oxide particles, thereby reducing the free surface-modifying material and improving the light transmittance of the dispersion, the composition produced using the same, and the sealing member. do.
Here, the above-mentioned "acid" refers to an acid based on the so-called Bronsted-Lowry definition, and here refers to a substance that gives protons in the hydrolysis reaction of the surface-modifying material. The above-mentioned "base" refers to a base based on the so-called Bronsted-Lowry definition, and here refers to a substance that accepts protons in the hydrolysis reaction and subsequent condensation reaction of the surface-modifying material.

The acid that can be used in the dispersion liquid according to the present embodiment is not particularly limited as long as it can supply protons in the hydrolysis reaction of the surface-modifying material. Examples include hydrochloric acid, hydrobromic acid, hydroiodic acid, Inorganic acids such as sulfuric acid, nitric acid, boric acid, phosphoric acid, etc., and organic acids such as acetic acid, citric acid, formic acid, etc. can be mentioned, and one of these can be used alone or in combination of two or more.

The base that can be used in the dispersion according to the present embodiment is not particularly limited as long as it can accept protons in the hydrolysis reaction of the surface-modifying material and the subsequent condensation reaction. Examples include sodium hydroxide and potassium hydroxide. , barium hydroxide, calcium hydroxide, ammonia, amines, and the like, and one of these can be used alone or two or more of them can be used in combination.

Among the above, it is preferable to use an acid as the catalyst. From the viewpoint of acidity, the acid is preferably an inorganic acid, more preferably hydrochloric acid.

Moreover, the content of the catalyst in the dispersion is not particularly limited. From the viewpoint of reducing impurities, it is preferable that no acid is contained in the final dispersion. However, it may remain in a trace amount as long as it does not impair the properties of the composition, etc., which will be described later. For example, it is 1 ppm or more and 100 ppm or less. From the viewpoint of preventing corrosion of metal parts present in the light-emitting device, the content can be 1 ppm or more and 50 ppm or less.

In addition, the dispersion according to the present embodiment may contain components other than those described above as necessary, such as dispersants, dispersing aids, antioxidants, fluidity modifiers, thickeners, pH adjusters, preservatives, etc. General additives and the like may be included.

In this specification, the dispersion liquid according to the present embodiment is distinguished from the composition (sealing resin composition) according to the present embodiment, which contains a resin component and can be cured to form a sealing member. . That is, the dispersion liquid according to the present embodiment does not contain a resin component, which will be described later, to the extent that the sealing member can be formed by simply curing. More specifically, the mass ratio of the resin component and the inorganic oxide particles in the dispersion liquid according to the present embodiment may be in the range of 0:100 to 40:60 (resin component:inorganic oxide particles). Preferably, it is in the range of 0:100 to 20:80. The dispersion liquid according to the present embodiment is more preferably essentially free of the resin component described below, and particularly preferably completely free of the resin component described below.
The dispersion liquid according to this embodiment is mixed with a resin component as described later and used as a sealing member in a light emitting device for sealing a light emitting element.

<2. Dispersion Production Method>
Next, a method for producing a dispersion liquid according to this embodiment will be described. The method for producing a dispersion according to the present embodiment includes a step of mixing a surface modifying material, an alcoholic solvent, and water to obtain a mixed solution (hydrolysis step), the mixed solution, inorganic oxide particles, and hydrophobic and a step of obtaining a dispersion liquid in which the inorganic oxide particles are dispersed (dispersion step).

(2.1 Hydrolysis step)
In this step, a mixed solution is obtained by mixing the surface modifying material, the alcoholic solvent, and water. As a result, a mixed liquid is obtained in which a part of the surface-modifying material in the mixed liquid is hydrolyzed. By using a mixed solution in which at least a part of the surface modification material has been hydrolyzed in advance, the surface modification material easily adheres to the inorganic oxide particles in the dispersing step described later.

On the other hand, when this step is omitted and the inorganic oxide particles are dispersed by mixing the materials in the dispersion step, the hydrolysis reaction of the surface modifying material is less likely to occur, and the surface modifying material is sufficiently attached to the inorganic oxide particles. In order to disperse the particles, it is necessary to apply more energy for dispersion. Therefore, in the dispersing step to be described later, the surface-modifying material unintentionally deteriorates, resulting in coloration of the dispersion, and insufficient dispersibility due to inadequate adhesion to the inorganic oxide particles. As a result, the light brightness of the light-emitting device manufactured using the resulting dispersion is not sufficiently high.

As the surface-modifying material, alcoholic solvent and water to be mixed in the liquid mixture, those mentioned as the constituent components of the dispersion liquid can be used.
The content of the surface-modifying material in the mixture is not particularly limited, but is, for example, 20% by mass or more and 70% by mass or less, preferably 30% by mass or more and 60% by mass or less, more preferably 4% by mass or more.
It can be 0% by mass or more and 50% by mass or less.

In addition, the content of the alcohol solvent in the mixed liquid is not particularly limited, but is, for example, 20% by mass or more and 70% by mass or less, preferably 30% by mass or more and 60% by mass or less, more preferably 40% by mass or more and 50% by mass. can be: As a result, the content of the surface-modifying material in the mixed liquid can be sufficiently increased, and a sufficient amount of water can be included in the mixed liquid. As a result, the hydrolysis reaction of the surface-modifying material can be efficiently performed. can proceed.

The content of water in the mixed liquid is not particularly limited, but is, for example, 1% by mass or more and 20% by mass or less, preferably 1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass or less. can be. This allows the hydrolysis reaction of the surface-modifying material to proceed appropriately, while preventing uniform mixing of water and aggregation of inorganic oxide particles in a dispersion liquid produced with an excessive amount of water. can do.

Furthermore, in order to more reliably mix water with the dispersion medium in the dispersion, the content of water contained in the dispersion is preferably 10% by mass or more and 14% by mass or less with respect to the content of the alcoholic solvent. More preferably, it is 11% by mass or more and 13% by mass or less.

Moreover, the above-described catalyst may be added to the mixed liquid. This can further promote the hydrolysis reaction of the surface modification material. The content of the catalyst in the mixed solution is not particularly limited, but can be, for example, 10 ppm or more and 1000 ppm or less, preferably 20 ppm or more and 800 ppm or less, more preferably 30 ppm or more and 600 ppm or less. This makes it possible to sufficiently promote the hydrolysis reaction of the surface-modifying material while suppressing unwanted side reactions of the surface-modifying material.

Moreover, after the mixed solution is prepared, it may be held at a constant temperature for a predetermined time. This can further promote hydrolysis of the surface modification material.
In this treatment, the temperature of the mixed solution is not particularly limited and can be appropriately changed depending on the type of the surface-modifying material.

The holding time is not particularly limited, but is, for example, 10 minutes or more and 180 minutes or less, preferably 30 minutes or more and 120 minutes or less.
It should be noted that the mixed liquid may be appropriately stirred during the holding of the mixed liquid.

(2.2 Dispersion step)
Next, the liquid mixture, the inorganic oxide particles, and the hydrophobic solvent are mixed to obtain a dispersion liquid in which the inorganic oxide particles are dispersed. As described above, the surface modification material is hydrolyzed in advance in the hydrolysis step. Therefore, in this step, the surface-modifying material is in a state where it easily adheres to the inorganic oxide particles, and the energy input for dispersing the inorganic oxide particles in this step can be reduced. As a result, unintentional deterioration of the surface-modifying material during dispersion is suppressed, the amount of free surface-modifying material is reduced, and the light transmittance of the dispersion is improved.

Further, in the present embodiment, the mixed liquid contains an alcohol-based solvent in advance. Therefore, the alcohol-based solvent can promote mixing of the hydrophobic solvent and the hydrolyzed surface modification material. This makes it easier for the surface-modifying material to adhere to the inorganic oxide particles.

In the liquid (dispersion liquid) obtained by mixing the mixed liquid, the inorganic oxide particles, and the hydrophobic solvent, the content of the alcohol solvent is not particularly limited, but is, for example, 1.0% by mass or more and 20% by mass or less. can be As a result, mixing of the hydrophobic solvent and the hydrolyzed surface modifying material by the alcoholic solvent can be further promoted. Furthermore, since the hydrophobic solvent can be sufficiently contained in the dispersion, the dispersibility of the inorganic oxide particles in the dispersion is improved. The content of the alcohol solvent is preferably 1.0% by mass or more and 15% by mass or less, more preferably 1.0% by mass or more and 10% by mass or less.

In the dispersion, the content of the alcohol solvent relative to the content of the hydrophobic solvent is not particularly limited, but is, for example, 1% by mass or more and 20% by mass, preferably 2% by mass or more and 15% by mass, more preferably 3% by mass. It can be more than mass % and less than 10 mass %. As a result, the dispersibility improvement effect of the inorganic oxide particles by the hydrophobic solvent can be sufficiently obtained, and the mixing of the hydrophobic solvent and the hydrolyzed surface-modifying material by the alcohol-based solvent can be further promoted.

The dispersion can be produced, for example, by mixing each component of the dispersion and then dispersing the mixture with a known dispersing machine while controlling the power of the dispersing machine. Here, the dispersion liquid according to the present embodiment is prepared by using a known dispersing machine, so that the particle size (dispersion particle size) of the inorganic oxide particles in the dispersion liquid becomes substantially uniform, and excessive energy is not applied. Instead, it is preferable to apply and disperse the minimum necessary energy.

As known dispersers, for example, bead mills, ball mills, homogenizers, dispersers, stirrers and the like are preferably used.

(2.3 Aging step)
If necessary, aging may be performed by maintaining the dispersion liquid obtained by the dispersion step at a predetermined temperature. This promotes the reaction of the surface modification material, and more surface modification material adheres to the inorganic oxide particles. As a result, the amount of free surface-modifying material present in the dispersion is reduced, and the dispersion stability of the inorganic oxide particles is further improved.

In this treatment, the temperature of the dispersion liquid is not particularly limited and can be appropriately changed depending on the type of the surface-modifying material. Alternatively, it may be the reflux temperature of the dispersion. That is, in this step, the aging may be performed by refluxing.

The retention time is not particularly limited, but is, for example, 30 minutes or more and 720 minutes or less, preferably 90 minutes or more and 180 minutes or less.
In addition, in holding the above dispersion, the mixed liquid may be stirred as appropriate.

By the above method, the dispersion liquid according to the present embodiment can be obtained. Since the dispersion obtained as described above requires a small amount of energy input during dispersion, unintentional deterioration of the surface modifier is suppressed. Moreover, the surface-modifying material sufficiently adheres to the inorganic oxide particles through the hydrolysis step, and the dispersibility of the inorganic oxide particles is improved.

<3. Composition>
Next, the composition according to this embodiment will be described. The composition according to this embodiment is obtained by mixing the dispersion liquid according to this embodiment and the resin component. Therefore, the composition according to the present embodiment contains the above-described inorganic oxide particles, a surface-modifying material at least partially attached to the inorganic oxide particles, and a resin component, that is, a resin and/or a precursor thereof. include.
In addition, the composition according to the present embodiment is cured as described later and used as a sealing member for a light-emitting element. That is, the composition according to this embodiment is a sealing resin composition.

The content of the inorganic oxide particles in the composition of the present embodiment is 0.005% by mass or more and 50% by mass or less from the viewpoint of obtaining high light scattering efficiency while increasing the transparency of the sealing member. more preferably 0.05% by mass or more and 30% by mass or less, and even more preferably 0.5% by mass or more and 20% by mass or less.

Also, 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 the main component in the composition according to this embodiment. When the composition according to the present embodiment is used as a sealing material, the resin component cures and seals the light-emitting element, thereby preventing deterioration factors from the external environment such as moisture and oxygen from reaching the light-emitting element. to prevent In addition, 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, and for example, resins such as silicone resins and epoxy resins can be used. In particular, silicone resins are preferred.

The silicone resin is not particularly limited as long as it is used as a sealing material. For example, dimethylsilicone resin, methylphenylsilicone resin, phenylsilicone resin, organically modified silicone resin, and the like can be used.

In particular, when a 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 is used as the surface modifying material, H—Si It is preferred to use a silicone resin having at least one functional group selected from the group consisting of a group, an alkenyl group and an alkoxy group. The reason is explained below.

Alkenyl groups of the surface modification material are crosslinked by reacting with H—Si groups in the silicone resin. The H—Si groups of the surface modification material are crosslinked by reacting with the alkenyl groups in the silicone resin. The alkoxy group of the surface modification material is condensed through hydrolysis with the alkoxy group in the silicone resin. Such bonding integrates the silicone resin and the surface-modifying material, thereby improving the strength and denseness of the resulting sealing member.

The structure of the resin component 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 cured polymer when used as a sealing member, and may be in a state before curing, that is, a precursor in the composition. Accordingly, the resin component present in the composition may be monomeric, oligomeric, or polymeric.

The resin component may be of an addition reaction type, a condensation reaction type, or a radical polymerization reaction type.
The viscosity of the resin component at 25° C. measured in accordance with JIS Z 8803:2011 is, for example, 0.1 Pa s or more and 100 Pa s or less, preferably 1 Pa s or more and 50 Pa s or less, more preferably 2 Pa s. s or more and 10 Pa·s or less.

Moreover, the content of the resin component in the composition according to the present embodiment can be the balance of other components, and is, for example, 80% by mass or more and 99.9% by mass or less.

The composition according to the present embodiment may contain the dispersion medium derived from the dispersion liquid according to the present embodiment, or may be removed. That is, the dispersion medium derived from the dispersion may be completely removed, and may remain in the composition in an amount of 1% by mass or more and 10% by mass or less relative to the mass of the composition, or 2% by mass or more and 5% by mass. The amount below may remain.
Moreover, the composition according to the present embodiment may contain water derived from the dispersion liquid according to the present embodiment, or may be removed. That is, the water derived from the dispersion liquid may be completely removed, and the water derived from the dispersion liquid and the resin component remains in the composition at about 0.1 ppm or more and 1,000 ppm or less with respect to the mass of the composition. 1 ppm or more and 600 ppm or less may remain.

Further, the composition according to the present embodiment may contain phosphor particles as long as the object of the present invention is not impaired. The phosphor particles absorb light of a specific wavelength emitted from the light emitting element and emit light of a predetermined wavelength. In other words, the phosphor particles can convert the wavelength of light and, in turn, 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 color of light emitted from 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 so as to obtain desired brightness.

In addition, the composition of the present embodiment contains commonly used additives such as preservatives, polymerization initiators, polymerization inhibitors, curing catalysts, light diffusing agents, etc., to the extent that the objects of the present invention are not impaired. may have been Silica particles having an average particle size of 1 to 30 μm are preferably used as the light diffusing agent.

The composition according to this embodiment can be produced, for example, by mixing the dispersion liquid according to this embodiment and a resin component. After mixing, if necessary, the dispersion medium contained in the dispersion may be removed by an evaporator or the like.

According to the embodiment described above, the composition according to the embodiment is obtained by mixing the dispersion liquid according to the embodiment and the resin component. Since the dispersion contains a hydrophobic solvent as a dispersion medium, the dispersion can be well mixed with the resin component, and the inorganic oxide particles are sufficiently dispersed and mixed in the composition without excessive agglomeration. In addition, the dispersion is prevented from being colored due to unintended deterioration of the surface-modifying material. Therefore, the composition according to the present embodiment suppresses a decrease in light transmittance due to the inorganic oxide particles when used as a sealing member, and the effect of improving the refractive index due to the inorganic oxide particles and the light emitted from the light emitting element. It is possible to fully exhibit the light scattering effect that is required. As a result, the brightness of light of a light-emitting device having a light-emitting element sealed with the composition according to this embodiment is improved.

<4. Sealing member>
The sealing member according to this embodiment is a cured product of the composition according to this embodiment. The sealing member according to the present embodiment is usually used as a sealing member arranged on the light emitting element or a part thereof.

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

The thickness and shape of the sealing member according to the present embodiment can be appropriately adjusted according to desired uses and characteristics, and are not particularly limited.

The average dispersed particle size of the inorganic oxide particles in the sealing member is preferably 10 nm or more and 500 nm or less, more preferably 20 nm or more and 300 nm or less, and still more preferably 40 nm or more and 200 nm or less.

When the average dispersed particle diameter is 10 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 diameter is 500 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 inorganic oxide particles in the sealing member is the number distribution-based average particle size (median size, D50) measured by transmission electron microscopy (TEM) of the sealing member. . Further, the average dispersed particle size of the inorganic oxide particles in the sealing member in the present embodiment is a value measured and calculated based on the dispersed particle size of the inorganic oxide particles in the sealing member. The average dispersed particle size is measured and calculated based on the diameter of the dispersed inorganic oxide particles, regardless of whether the inorganic oxide particles are dispersed as primary particles or secondary particles. . Further, in the present embodiment, the D50 of the inorganic oxide particles in the sealing member may be measured as the D50 of the inorganic oxide particles to which the surface modification material is adhered. In the sealing member, inorganic oxide particles to which the surface modifying material is attached and inorganic oxide particles to which the surface modifying material is not attached may exist. D50 is measured as a value in these mixed conditions.

Since the sealing member according to the present embodiment is a cured product of the composition according to the present embodiment, it has excellent light transmittance, the effect of improving the refractive index due to the inorganic oxide particles, and the light emitted from the light emitting element. The scattering effect of is fully exhibited. Therefore, the light emitting device using the sealing member according to this embodiment has improved brightness of emitted light.

<5. Light-emitting device>
Next, the light emitting device according to this embodiment will be described. A light-emitting device according to this embodiment includes the above-described sealing member and a light-emitting element sealed with the sealing member.
Examples of light-emitting elements include light-emitting diodes (LEDs) and organic light-emitting diodes (OLEDs). In particular, the sealing member according to this embodiment is suitable for sealing light emitting diodes.

The light-emitting device according to the present embodiment will be described below by taking 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. FIG. 1 is a schematic diagram (cross-sectional view) showing an example of a light-emitting device according to an embodiment of the present invention. Note that the size of each member in the drawings is appropriately emphasized for ease of explanation, and does not represent actual dimensions or ratios between members.

A light emitting device (LED package) 1 shown in FIG. and a sealing member 4 for sealing.

The sealing member 4 is configured by the sealing member according to the present embodiment described above. Therefore, the sealing member 4 has a high light transmittance due to its suppressed coloring, and fully exhibits the effect of improving the refractive index due to the inorganic oxide particles and the effect of scattering the light emitted from the light emitting element. It is Therefore, the brightness of the light from the light emitting device 1 is improved. Further, phosphor particles 5 are dispersed in the sealing member 4 . The phosphor particles 5 convert the wavelength of at least part of the light emitted from the light emitting element 3 .

It should be noted that 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 contain phosphor particles in the sealing member. Moreover, the sealing member according to the present embodiment can exist at any position in the light emitting device as long as it can seal the light emitting element. Moreover, in one embodiment of the present invention, the sealing member is composed of a plurality of layers, and the composition of these layers may be the same or different. In this case, any one or more layers are composed of the sealing member according to the present embodiment.

As described above, the light-emitting device according to the present embodiment is excellent in light brightness because the light-emitting element is sealed with the sealing member of the present embodiment.

In addition, 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, which includes sealing a light-emitting element using the composition according to this embodiment. In the same aspect, the production method may include a step of mixing the dispersion liquid according to the present embodiment and a resin component to produce the composition. Furthermore, at least part of the dispersion medium may be removed in the process of producing the composition.

The light-emitting device according to this embodiment as described above can be used, for example, in lighting fixtures and display devices. Accordingly, in one aspect, the present invention relates to a lighting fixture or display device comprising the light emitting device according to the present embodiments.

Examples of lighting fixtures include general lighting devices such as indoor lights and outdoor lights, lighting for switch units of electronic devices such as mobile phones and OA equipment, and the like.
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 luminous flux emitted is greater than in the conventional case, and the surrounding environment can be made brighter. can.

Examples of display devices include mobile phones, personal digital assistants, electronic dictionaries, digital cameras, computers, televisions, and their peripherals.
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 luminous flux emitted is greater than that of the conventional display device. It can be performed.

The present invention will be described in more detail below with reference to examples. It should be noted that the embodiments described below are merely examples of the present invention, and do not limit the present invention.

[Example 1]
(Preparation of dispersion liquid)
(1) Hydrolysis step 5 parts by mass of a methoxy group-containing phenyl silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name KR217) as a surface modification material and 5 parts by mass of methanol were mixed. Then, 0.4 parts by mass of water and 0.2 parts by mass of hydrochloric acid (1N) were added and mixed. This mixture was then stirred at 60° C. for 30 minutes to hydrolyze the methoxy group-containing phenylsilicone resin.

(2) Dispersion step 10 parts by mass of zirconium oxide particles (manufactured by Sumitomo Osaka Cement Co., Ltd.) having an average primary particle size of 12 nm, 82 parts by mass of toluene, and 10.6 parts by mass of the above mixture are mixed to form a second mixture. This second mixture was subjected to a dispersion treatment for 6 hours using a bead mill, and then the beads were removed. The content of methanol in the dispersion liquid in this step was 4.9% by mass.

(3) Aging step After removal of the beads, the dispersion liquid was refluxed in an oil bath at 130°C for 6 hours to obtain the dispersion liquid according to Example 1 in which the zirconium oxide particles were surface-modified with the methoxy group-containing phenyl silicone resin. .

(Evaluation of dispersion liquid)
1.2 g of the resulting dispersion was placed in a magnetic crucible and heated on a hot plate at 150° C. for 1 hour. As a result, the solid content was 32.6% by mass. The solid content is the percentage of the value obtained by dividing the mass of the component remaining without volatilization by the mass of the dispersion liquid (1.2 g). In addition, the obtained solid content mainly contains zirconium oxide particles and surface modification material. Therefore, the obtained solid content is considered to correspond to the total content of the zirconium oxide particles and the surface-modifying material (surface-modified zirconium oxide particles) in the dispersion.

The water content of the resulting dispersion was measured with a Karl Fischer moisture meter (model number: AQ-2000 (coulometric method), manufactured by Hiranuma Sangyo Co., Ltd.) and found to be 358 ppm.
In addition, the dispersion was burned in a combustion device, the generated combustion decomposition gas was collected in the absorbent, and the content of hydrochloric acid contained in the dispersion was measured by ion chromatography. there were.
Furthermore, as a result of detecting methanol in the dispersion by gas chromatography, it was confirmed that methanol was contained in the dispersion.

Furthermore, using a dispersion diluted with toluene so that the solid content is 5% by mass, the integrated transmittance at a wavelength of 460 nm is measured using a quartz cell with an optical path length of 10 mm with a spectrophotometer (manufactured by JASCO Corporation, model number: V -770) was 31%.
In addition, the average dispersed particle diameter D50 of the zirconium oxide particles contained in the dispersion diluted with toluene so that the solid content was 5% by mass was measured using a particle size distribution analyzer (manufactured by HORIBA, model number: SZ-100SP). . As a result, D50 was 35 nm.

(Evaluation of content of free surface-modifying material)
5 g of the obtained dispersion liquid (total content of zirconium oxide particles and surface modifying material: 1.6 g) was removed by an evaporator.
2 g of acetone was added to this concentrate and mixed to prepare a mixture.
The extract separated from the mixture was collected by column chromatography using a column filled with 10 g of silica gel and 100 cc of developing solvent (hexane and acetone mixed at a volume ratio of 2:1). The collected liquid was removed by an evaporator, and the resulting residue was used as a free surface-modifying material, and its mass was measured. The percentage of the value obtained by dividing the mass of this residue by the total mass (1.6 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 25% by mass.

(Production of composition)
10 parts by mass of the resulting dispersion, methyl phenyl silicone resin ("KER-6150 (A / B) (A liquid: B liquid = 1: 1)" refractive index 1.41) 7.6 manufactured by Shin-Etsu Chemical Co., Ltd. Parts by mass (3.8 parts by mass of A liquid and 3.8 parts by mass of B liquid) were mixed. That is, they were mixed so that the surface-modified zirconium oxide particles accounted for 30% by mass of the total content of the methylphenyl silicone resin and the surface-modified zirconium oxide particles. Then, by removing toluene from this mixed solution with an evaporator, a composition according to Example 1 containing the zirconium oxide particles to which the surface modifying material was attached, the methylphenylsilicone resin, and the reaction catalyst was obtained.

(Evaluation of composition)
The obtained composition according to Example 1 was sandwiched between thin-layer quartz cells to have a thickness (optical path length) of 1 mm, and the integrated transmittance at a wavelength of 460 nm was measured with a spectrophotometer (manufactured by JASCO Corporation, model number: V- 770) was 51%.
Further, the viscosity of the obtained composition according to Example 1 was measured using a rheometer (Rheostress RS-6000, manufactured by HAAKE) under the condition of a shear rate of 1 (1/s), and it was 52 Pa s. Met. In addition, the measurement of the viscosity was performed at the temperature of 25 degreeC based on JISZ8803.

(Production of LED package)
To 1 part by mass of the resulting composition, 14 parts by mass of a methylphenyl silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd. "KER-6150 (A/B)" was added, and the composition contained 2% by mass of surface-modified zirconium oxide particles. A composition (total amount of surface-modified zirconium oxide particles and resin: Phosphor particles=100:38) is filled into the LED lead frame to a thickness of 300 μm.Then, it is kept at room temperature for 3 hours.Then, the composition is slowly heat-cured to form a sealing member. A white LED package according to Example 1 was produced.

Luminous efficiency of the resulting white LED package was measured by applying a voltage of 3 V and a current of 150 mA to the LED package and performing photometry using a total luminous flux measurement system (manufactured by Otsuka Electronics Co., Ltd.). As a result, the brightness of the white LED package according to Example 1 was 76.9 lm.

[Examples 2 to 4]
(Preparation of dispersion liquid)
Dispersions according to Examples 2 to 4 were prepared in the same manner as in Example 1, except that the amount of methanol mixed in the hydrolysis step was changed as shown in Table 1. The amount of the mixed liquid added in the dispersing step was adjusted so that the amount of the methoxy group-containing phenylsilicone resin was the same as in Example 1. Table 1 shows the content of methanol in the dispersion liquid in the dispersion step.

(Evaluation of dispersion liquid)
Regarding the obtained dispersions according to Examples 2 to 4, in the same manner as in Example 1, the solid content, water, hydrochloric acid, the content of the free surface-modifying material, the average dispersed particle diameter D50 of the zirconium oxide particles, and the dispersion at a wavelength of 460 nm Integrated transmittance was measured. Table 1 shows the results.
Furthermore, as a result of detecting methanol in the dispersion liquid by gas chromatography, it was confirmed that methanol was contained in all of the dispersion liquids according to Examples 2 to 4.

(Preparation and evaluation of composition)
Compositions were prepared in the same manner as in Example 1, except that the amount of the dispersion liquid charged was changed as shown in Table 1, and compositions according to Examples 2 to 4 were obtained. Regarding the obtained composition, in the same manner as in Example 1, the integrated transmittance and viscosity at a wavelength of 460 nm were measured. Table 1 shows the results.

(Production and evaluation of LED packages)
White LED packages according to Examples 2 and 3 were produced in the same manner as in Example 1 using the obtained compositions. The brightness of light of the obtained white LED package was measured in the same manner as in Example 1. Table 1 shows the results.

[Comparative Example 1]
(Preparation of dispersion liquid)
Zirconium oxide particles with an average primary particle size of 12 nm (manufactured by Sumitomo Osaka Cement Co., Ltd.) 10 parts by weight, toluene 82 parts by weight, 5 parts by weight of methoxy group-containing phenyl silicone resin (Shin-Etsu Kogyo Chemical Co., Ltd. KR217) as a surface modification material, water 0.05 parts by mass were mixed and dispersed in a bead mill for 6 hours. Next, the dispersion after removal of the beads was refluxed in an oil bath at 130° C. for 6 hours to obtain a dispersion according to Comparative Example 1 in which the zirconium oxide particles were surface-modified with the methoxy group-containing phenylsilicone resin.

(Evaluation of dispersion liquid)
Regarding the obtained dispersion liquid according to Comparative Example 1, in the same manner as in Example 1, solid content, water, hydrochloric acid, content of free surface modifying material, average dispersed particle diameter D50 of zirconium oxide particles, and integrated transmission at a wavelength of 460 nm were measured. rate was measured. Table 1 shows the results.

(Preparation and evaluation of composition)
A composition was prepared in the same manner as in Example 1, except that the amount of the dispersion liquid charged was changed as shown in Table 1, and a composition according to Comparative Example 1 was obtained. Regarding the obtained composition, in the same manner as in Example 1, the integrated transmittance and viscosity at a wavelength of 460 nm were measured. Table 1 shows the results.

(Production and evaluation of LED packages)
A white LED package according to Comparative Example 1 was produced in the same manner as in Example 1 using the obtained composition. The brightness of light of the obtained white LED package was measured in the same manner as in Example 1. Table 1 shows the results.

[Comparative Example 2]
(Preparation of dispersion liquid)
A dispersion liquid according to Comparative Example 2 was prepared in the same manner as in Example 1, except that the mixed amount of methanol in the hydrolysis step was changed as shown in Table 1. The amount of the mixed liquid added in the dispersing step was adjusted so that the amount of the methoxy group-containing phenylsilicone resin was the same as in Example 1.

(Evaluation of dispersion liquid)
Regarding the obtained dispersion liquid according to Comparative Example 2, in the same manner as in Example 1, the solid content, water, hydrochloric acid, content of free surface modifying material, average dispersed particle diameter D50 of zirconium oxide particles, and integrated transmission at a wavelength of 460 nm were determined. rate was measured. Table 1 shows the results.

(Preparation and evaluation of composition)
A composition was prepared in the same manner as in Example 1, except that the amount of the dispersion liquid charged was changed as shown in Table 1, and a composition according to Comparative Example 2 was obtained. Regarding the obtained composition, in the same manner as in Example 1, the integrated transmittance and viscosity at a wavelength of 460 nm were measured. Table 1 shows the results.

(Production and evaluation of LED packages)
A white LED package according to Comparative Example 2 was produced in the same manner as in Example 1 using the obtained composition. The brightness of light of the obtained white LED package was measured in the same manner as in Example 1. Table 1 shows the results.

From the results of Examples 1 to 3 and Comparative Examples 1 and 2, in Examples 1 to 3 according to the present invention, the obtained composition has excellent integrated transmittance, and as a result, the obtained light emitting device (LED package) can improve the brightness of the light.

Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, 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 belongs can conceive of various modifications or modifications within the scope of the technical idea described in the claims. It is understood that these also naturally belong to the technical scope of the present invention.

REFERENCE SIGNS LIST 1 light emitting device 2 substrate 21 recess 3 light emitting element 4 sealing member 5 phosphor particles

Claims (7)

Containing inorganic oxide particles, a surface-modifying material at least partially attached to the inorganic oxide particles, a dispersion medium, and water,
the dispersion medium comprises an alcoholic solvent and a hydrophobic solvent,
The water content is 10 ppm or more and 2000 ppm or less,
The content of the surface-modifying material not attached to the inorganic oxide particles is 50% by mass or less with respect to the content of solids in the dispersion ,
The dispersion liquid, wherein the surface-modifying material has at least one functional group selected from the group consisting of alkenyl groups, H—Si groups, and alkoxy groups . 10. The dispersion of Claim 1, further comprising a catalyst. A composition for encapsulating a light-emitting element, obtained by mixing the dispersion liquid according to claim 1 or 2 and a resin component. A sealing member, which is a cured product of the composition according to claim 3 . A light-emitting device comprising: the sealing member according to claim 4; and a light-emitting element sealed with the sealing member. A lighting fixture or display device comprising the light emitting device according to claim 5 . a step of mixing a surface modifying material, an alcoholic solvent and water to obtain a mixture;
A method for producing a dispersion, comprising mixing the mixture, inorganic oxide particles, and a hydrophobic solvent to obtain a dispersion in which the inorganic oxide particles are dispersed.

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