JP4961828B2 - Method for producing nanoparticle-resin composite material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a nanoparticle-resin composite material that is transparent in a visible light range and has a refractive index of &ge;1.55. <P>SOLUTION: The nanoparticle-resin composite material comprises inorganic nanoparticles dispersed in a siloxane crosslinked product in which the inorganic nanoparticles are coated with an organic compound. The nanoparticle-resin composite material is transparent in a visible light range and has a refractive index of &ge;1.55 in a visible light range. The siloxane crosslinked product has a siloxane bond (Si-O-Si bond) and is formed based on the crosslinking of a siloxane compound containing a reactive functional group. The organic compound contains a functional group to form a covalent bond or ionic bond to the surface of an inorganic nanoparticle and an organic group exhibiting an affinity for the siloxane compound and has a molecular weight of &le;1&times;10<SP>3</SP>. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a nanoparticle-resin composite material comprising an inorganic nanoparticle and a crosslinked product having a siloxane bond, transparent in the visible light region and having a high refractive index, and a method for producing the same, and further to the nanoparticle-resin The present invention relates to a light emitting element assembly using a composite material, a filling material for the light emitting element assembly, and an optical material.

  A light-emitting element assembly including a light-emitting element such as a light-emitting diode (LED) or a laser diode (LD) is small in size and high in luminance, and therefore has various uses such as an automobile stop lamp, a signal light, and a large outdoor display. Used in. In addition, since it has low power consumption and long life, it has recently been used as a light source for liquid crystal displays for mobile phones and backlights for large liquid crystal televisions.

  In general, a light emitting device assembly is intended to prevent light emitting devices and wiring from coming into direct contact with oxygen, moisture, and other corrosive gases, and to prevent physical damage to the light emitting device due to external forces. For example, as shown in FIG. 3, a sealing member 114 having an appropriate thickness is disposed on or above the light emitting element 12. Usually, the sealing member 114 is made of a transparent resin such as an epoxy resin, a silicone resin, or an acrylic resin. However, in the conventional light emitting device assembly, since the difference in refractive index between the light emitting device 12 and the sealing member 114 is large, a part of the light emitted from the light emitting device 12 is part of the light emitting device 12 and the sealing member 114. There is a problem in that the light extraction efficiency is reduced because the light that has been totally reflected at the interface and is totally absorbed by the light emitting element 12. Reference numeral 11 is a reflective cup.

  In order to improve such a problem, JP 2004-15063 A disperses nanoparticles having a refractive index higher than that of the matrix resin and having a particle size smaller than the emission wavelength in the matrix resin. A technique for bringing the effective refractive index of the entire material closer to that of a light emitting element is disclosed. Japanese Unexamined Patent Application Publication No. 2005-5740 discloses a resin material (encapsulation material) in a form in which a resin and a filler such as titanium oxide or glass are mixed. Furthermore, JP-T-2004-537767 discloses an optical structure in which a polymer and inorganic nanoparticles are blended to control the refractive index.

As described above, an epoxy resin, a silicone resin, an acrylic resin, or the like is used as the sealing member that constitutes the light emitting element assembly. In many cases, an epoxy resin is used. However, in recent years, several problems to be improved have been pointed out for high-power light-emitting elements, for which demand is increasing. According to Phys. Stat. Sol. (A) 194, No. 2, 380-388 (2002), the glass transition point T _g of the epoxy resin is 100 to 150 ° C., and above the glass transition point T _g. It has been reported that the coefficient of linear expansion increases. When the epoxy resin is heated to the glass transition point _Tg or more by the heat generation of the light emitting element, the wiring connected to the light emitting element may be disconnected. Thus, the output of the light emitting element is limited forced to also output as an epoxy resin does not exceed the glass transition temperature T _g by heating the light-emitting element. In addition, since the epoxy resin turns yellow when exposed to blue light, the output of the entire light emitting element assembly decreases with time. For this reason, a silicone resin has recently been used as a material to replace the epoxy resin.

JP 2004-15063 A JP 2005-5740 A JP-T-2004-537767 Phys. Stat. Sol. (A) 194, No. 2, 380-388 (2002)

  However, Japanese Patent Application Laid-Open No. 2004-15063 shows a combination example of a matrix resin and nanoparticles, and only describes that nanoparticles are dispersed in the matrix resin. In order to uniformly disperse nanoparticles of several nanometers in the matrix resin without agglomeration, for example, a chemical surface treatment to improve the affinity between the nanoparticles and the matrix resin is performed by nano-particles. However, Japanese Patent Application Laid-Open No. 2004-15063 does not show any such technique. Japanese Patent Application Laid-Open No. 2005-5740 does not show any technique for uniformly mixing a resin and a filler such as titanium oxide or glass without agglomeration. Japanese Patent Publication No. 2004-537767 discloses an idea of using a linker that activates the surface of the inorganic nanoparticles to disperse the inorganic nanoparticles in the polymer, but the inorganic nanoparticles are appropriately used in the silicone polymer. No specific technique for dispersal is presented.

  Silicone resin has good light resistance, and can suppress a decrease in output when using blue light. Further, since it has appropriate flexibility, even when it becomes high temperature, it has stress. Can be suppressed. However, since the refractive index of a silicone resin in practical use is about 1.5 at most, further increase in the refractive index is desired from the viewpoint of improving the light extraction efficiency.

  Accordingly, an object of the present invention is to provide a nanoparticle-resin composite material (composite material composed of inorganic nanoparticles and a polymer) having a refractive index of 1.55 or more in the visible light region, and a method for producing the same. Another object of the present invention is to provide a light emitting device assembly to which the nanoparticle-resin composite material is applied, a filling material for the light emitting device assembly, and an optical material.

In order to achieve the above object, the nanoparticle-resin composite material of the present invention is formed by dispersing inorganic nanoparticles in a siloxane cross-linked product, and the inorganic nanoparticles are coated with an organic compound. A nanoparticle-resin composite material that is transparent and has a refractive index of 1.55 or more,
The siloxane cross-linked product is formed based on cross-linking of a siloxane compound having a siloxane bond (Si—O—Si bond) and containing a reactive functional group,
The organic compound has a functional group that forms a covalent bond or an ionic bond with the surface of the inorganic nanoparticles and an organic group that has an affinity for the siloxane compound, and has a molecular weight of 1 × 10 ³ or less.

In order to achieve the above object, the method for producing a nanoparticle-resin composite material of the present invention comprises:
Inorganic nanoparticles are dispersed in the siloxane crosslinked product, the inorganic nanoparticles are coated with an organic compound, are transparent in the visible light region, and have a refractive index of 1.55 or more.
The siloxane cross-linked product is formed based on cross-linking of a siloxane compound having a siloxane bond (Si—O—Si bond) and containing a reactive functional group,
The organic compound has a functional group that forms a covalent bond or an ionic bond with the surface of the inorganic nanoparticle, and an organic group that has an affinity for the siloxane compound, and has a molecular weight of 1 × 10 ³ or less. A manufacturing method of
(A) After the inorganic nanoparticles and the organic compound are dispersed in the liquid phase and the surface of the inorganic nanoparticles is coated with the organic compound,
(B) mixing inorganic nanoparticles coated with an organic compound and a siloxane compound;
(C) the siloxane compound is crosslinked by heating, thereby forming a siloxane crosslinked product;
A process is provided.

In the method for producing a nanoparticle-resin composite material of the present invention, the step (B) comprises:
(B-1) Inorganic nanoparticles coated with an organic compound and a siloxane compound [1] having an addition reactive carbon-carbon double bond to which a platinum group catalyst is added are mixed to obtain a mixture [1]. Obtaining step,
(B-2) mixing inorganic nanoparticles coated with an organic compound and a siloxane compound [2] having a hydrogen atom bonded to a silicon atom to obtain a mixture [2], and
(B-3) mixing the obtained mixture [1] and mixture [2],
Consisting of
In the step (C), the mixed mixture [1] and the mixture [2] can be heated.

Alternatively, in the method for producing a nanoparticle-resin composite material of the present invention, the step (B) includes:
(B-1) A step of obtaining a mixture [1] by mixing inorganic nanoparticles coated with an organic compound and a siloxane compound [1] having an addition-reactive carbon-carbon double bond,
(B-2) A step of obtaining a mixture [2] by mixing inorganic nanoparticles coated with an organic compound and a siloxane compound [2] having a hydrogen atom bonded to a silicon atom to which a platinum group catalyst is added. ,as well as,
(B-3) mixing the obtained mixture [1] and mixture [2],
Consisting of
In the step (C), the mixed mixture [1] and the mixture [2] can be heated.

To achieve the above object, a light emitting device assembly according to a first aspect of the present invention comprises:
(A) a light emitting element,
(B) a sealing member for sealing the light emitting element, and
(C) a filling material filled in a gap existing between the light emitting element and the sealing member;
Comprising
The filling material is composed of the nanoparticle-resin composite material of the present invention.

In order to achieve the above object, a light emitting device assembly according to a second aspect of the present invention includes:
(A) a light emitting element, and
(B) a sealing member for sealing the light emitting element;
Comprising
The sealing member is made of the nanoparticle-resin composite material of the present invention.

  In order to achieve the above object, a filling material for a light emitting device assembly of the present invention is characterized by comprising the nanoparticle-resin composite material of the present invention.

  In order to achieve the above object, an optical material of the present invention comprises the nanoparticle-resin composite material of the present invention.

Nanoparticle-resin composite material of the present invention, method for producing nanoparticle-resin composite material of the present invention including the above-mentioned preferred embodiments, light emitting device assembly of the present invention, filling material for light emitting device assembly of the present invention, book In the optical material of the invention (hereinafter, these may be collectively referred to as the present invention), the organic compound functions as a surfactant or a dispersant. Of the organic compounds described above, carboxylic acid, phosphinic acid, phosphonic acid, sulfinic acid, and sulfonic acid are ionically bonded to the inorganic nanoparticle surface, and thiol is covalently bonded to the inorganic nanoparticle surface. Alternatively, the organic compound has a functional group that forms a coordinate bond or a hydrogen bond with the inorganic nanoparticle surface, and has an organic group that has an affinity for a siloxane compound, and has a molecular weight of 1 × 10 ³ or less. Certain organic compounds can also be selected. Here, when the molecular weight of the organic compound exceeds 1 × 10 ³ , the ratio of the organic matter including the siloxane cross-linked product is relatively increased, so that the volume filling rate of the inorganic nanoparticles in the nanoparticle-resin composite material is sufficient. As a result, there is a possibility that the refractive index of the nanoparticle-resin composite material cannot be set to a desired value. Dispersion of the inorganic nanoparticles in the nanoparticle-resin composite material can be achieved by appropriately selecting an organic compound and a siloxane compound constituting the siloxane crosslinked product. In addition, the molecular weight of an organic compound means the relative value by polystyrene conversion measured using gel permeation chromatography (GPC), and molecular weight.

  In the present invention, the inorganic nanoparticles desirably have a refractive index of 1.9 or more in the visible light region. Here, the refractive index of an inorganic nanoparticle means the refractive index of the bulk of the material which comprises an inorganic nanoparticle more specifically.

  Various materials such as the refractive index of inorganic nanoparticles (more specifically, the refractive index of the bulk of the material constituting the inorganic nanoparticles), the refractive index of the nanoparticle-resin composite material, the siloxane cross-linked product, the refractive index of the siloxane compound The refractive index can be measured using an Abbe refractometer or a V-block refractometer.

In the present invention, the inorganic nanoparticles include titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), cerium oxide (CeO ₂ ), hafnium oxide (HfO ₂ ), niobium pentoxide (Nb ₂ O ₅ ), five At least one selected from the group consisting of tantalum oxide (Ta ₂ O ₅ ), indium oxide (In ₂ O ₃ ), tin oxide (SnO ₂ ), ITO, zinc oxide (ZnO), and silicon (Si) It is desirable to consist of materials. The inorganic nanoparticles may be composed of one of these materials, or may be composed of a mixture of two or more. In addition, inorganic nanoparticles can also be formed from nitrides containing the above metals.

In the present invention including the above desirable form, the particle size (D) of the inorganic nanoparticles is 2 × 10 ⁻⁹ m to 2 × 10 ⁻⁸ m, preferably 2 × 10 ⁻⁹ m to 1.0 × 10 ^{−. 8} m is desirable. Here, the particle size of the inorganic nanoparticles can be obtained by measuring the particle size of the inorganic nanoparticles observed with a transmission electron microscope (TEM). When the shape (planar shape) of the inorganic nanoparticles observed with a transmission electron microscope is not circular, a circle having the same area as the observed inorganic nanoparticles is assumed, and the diameter of the circle is defined as the particle size. do it. Examples of the three-dimensional shape of the particles when the shape (three-dimensional shape) of the inorganic nanoparticles is not spherical include a rod shape, a spheroid shape, and a rectangular parallelepiped shape. The particle size of the inorganic nanoparticles in the nanoparticle-resin composite material can be obtained, for example, by preparing a flake using a microtome and observing it with a transmission electron microscope. Further, when the average value of the particle size of the inorganic nanoparticles is D _ave and the standard deviation is σ, the upper limit of the particle size (D) of the inorganic nanoparticles is 2 × 10 ⁻⁸ m as described above, preferably 1.0 × 10 ⁻⁸ m
D _ave + 2σ ≦ 2 × 10 ⁻⁸ m
Or
D _ave + 2σ ≦ 1.0 × 10 ⁻⁸ m
It means that. By defining the particle size (D) of the inorganic nanoparticles to 2 × 10 ⁻⁹ m to 2 × 10 ⁻⁸ m, the light transmittance in the nanoparticle-resin composite material is reduced and the light is lost due to Rayleigh scattering. In practice, it is possible to obtain a nanoparticle-resin composite material that is practically transparent in the visible light region. Since the light transmittance decreases exponentially as the optical path length increases, as described later, it is preferable to use smaller inorganic nanoparticles as the optical path length increases. When an aggregate of inorganic nanoparticles is formed in the nanoparticle-resin composite material, the size of the aggregate acts as the effective particle size, so the inorganic nanoparticles form aggregates in order to suppress light scattering. It is necessary to be filled in a dispersed state so as not to occur.

In the present invention including the desirable form and configuration described above, the siloxane compound is
Siloxane compound [1] having an addition-reactive carbon-carbon double bond,
A siloxane compound [2] having a hydrogen atom bonded to a silicon atom, and
Platinum group catalyst,
Preferably it consists of. In addition, the general formula of siloxane compound [1] and siloxane compound [2] is shown to the following general formula (1-1) and general formula (2-1). In addition, general formula (1-1) is a case where the main chain is linear or branched, and general formula (2-1) is a cyclic diorganopolysiloxane. In addition to a hydrogen atom bonded to an addition-reactive carbon-carbon double bond and a silicon atom, a monovalent hydrocarbon group other than a phenyl group and a phenyl group is included in the side chain or terminal. Furthermore, in the siloxane compound [1] and the siloxane compound [2], a part of the side chain and / or the terminal may be substituted with an epoxy group, a carboxy group, a polyether group, or a carbinol group. Alternatively, in the nanoparticle-resin composite material, the light emitting device assembly, the filling material for the light emitting device assembly, or the optical material of the present invention, in this case, a siloxane compound to which a platinum group catalyst is added [ 1] and a mixture of inorganic nanoparticles coated with an organic compound [1] and a mixture of a siloxane compound [2] and an inorganic nanoparticle coated with an organic compound [2]. A product is obtained, or alternatively, a mixture [1] of a siloxane compound [1] and inorganic nanoparticles coated with an organic compound, and a siloxane compound [2] to which a platinum group catalyst is added and an organic compound. Desirably, a siloxane cross-linked product is obtained by mixing and heating the mixture [2] with the coated inorganic nanoparticles. By separating the siloxane compound [1] and the siloxane compound [2], long-term storage is possible. That is, the so-called pot life is lengthened. The inorganic nanoparticles contained in the mixture [1] and the inorganic nanoparticles contained in the mixture [2] may be the same type of inorganic nanoparticles or different types of inorganic nanoparticles. Good. In the general formula (1-1), “m” is an integer of 1 or more, “n”, “l”, “p”, “q” are integers of 0 or more (including 0), The sum of “n” and “l” is 1 or more [(n + 1) ≧ 1]. “X” is an addition-reactive carbon-carbon double bond (in the case of a siloxane compound [1]) or a hydrogen atom bonded to a silicon atom (in the case of a siloxane compound [2]). However, when p = 0, “X” is indispensable at both ends. Furthermore, “Y” is an organosiloxane. In the general formula (2-1), “m” is an integer of 1 or more, “n”, “l”, “q” are integers of 0 or more (including 0), and “n” ”And“ l ”is 1 or more [(n + 1) ≧ 1], and“ p ”is an integer of 2 or more. Furthermore, “X” is an addition-reactive carbon-carbon double bond (in the case of a siloxane compound [1]) or a hydrogen atom bonded to a silicon atom (in the case of a siloxane compound [2]), “Y” is an organosiloxane.

Chain siloxane compounds

Cyclic siloxane compound

  Here, the addition reactivity means the property of hydrosilylation reaction with a hydrogen atom bonded to a silicon (Si) atom. In the siloxane compound [1] and the siloxane compound [2], the amount of hydrogen atoms bonded to the carbon-carbon double bond and the Si atom is 2 or more per molecule of the siloxane compound.

  In the present invention, examples of the reactive functional group (carbon-carbon double bond) contained in the siloxane compound include a vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, hexenyl group, cyclohexenyl group, and octenyl group. be able to. And the side chain and / or terminal of a siloxane compound are substituted by this reactive functional group.

  More specifically, examples of the siloxane compound [1] include the following structural formulas (1-2), (1-3), (1-4), and (1-5). Can do. More specific examples of the siloxane compound [2] include the following structural formulas (2-2), (2-3), (2-4), and (2-5). can do.

  Examples of the platinum group catalyst as the curing catalyst include chloroplatinic acid, platinum acetylacetonate, a complex of chloroplatinic acid and octanol, and a complex of platinum with vinylsiloxane. The addition amount of the platinum group catalyst is preferably in the range of 0.5 ppm to 200 ppm on a weight basis as platinum with respect to the total amount of siloxane compounds. If the amount of platinum group catalyst added is too large, problems such as yellowing and browning occur.

  Furthermore, in the present invention including the desirable forms and configurations described above, the organic compound is at least selected from the group consisting of carboxylic acid, phosphinic acid, phosphonic acid, sulfinic acid, sulfonic acid, and thiol. It is one kind of compound and the selected compound preferably contains an aryl group, an aryloxy group, an alkyl group or an olefin chain. Here, the organic compound is specifically hexanoic acid, octanoic acid, decanoic acid, dodecanoic acid, hexadecanoic acid, octadecanoic acid, oleic acid, linoleic acid, benzoic acid, acetylbenzoic acid, diphenyl-4-benzoic acid, Phenylacetic acid, diphenylacetic acid, methylbenzoic acid, butylbenzoic acid, phenoxyacetic acid, phenoxybenzoic acid, phenylbutanoic acid, phenylbutyric acid, diphenylphosphinic acid, phenylphosphonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, decanethiol, dodecanethiol , Octadecanethiol. In addition, these organic compounds can be used by blending a plurality of them in an arbitrary ratio according to the siloxane compound to be used. An olefin chain means a hydrocarbon group containing one or more double bonds.

  Alternatively, in the present invention including the desirable forms and configurations described above, the organic compound is preferably a silane compound containing an aryl group, aryloxy group, alkyl group or olefin chain. Specific examples of such silane compounds include octyltrimethoxysilane, octyldimethylmethoxysilane, octyltriethoxysilane, octylmethyldiethoxysilane, octyltrichlorosilane, dodecyltriethoxysilane, dodecyltrichlorosilane, and 7-octenyldimethylchlorosilane. 7-octenyltrimethoxysilane, 4-phenylbutyldimethylchlorosilane, 4-phenylbutyltrichlorosilane, 3-phenoxypropyltrichlorosilane, 3-phenoxypropyldimethylchlorosilane, m-phenoxyphenyldimethylchlorosilane, styrylethyltrimethoxysilane Can be mentioned. Silane compounds such as 4-phenylbutyldimethylchlorosilane, 4-phenylbutyltrichlorosilane, 3-phenoxypropyltrichlorosilane, 3-phenoxypropyldimethylchlorosilane, m-phenoxyphenyldimethylchlorosilane, and styrylethyltrimethoxysilane have a refractive index. Since it is high, it is suitable for increasing the refractive index of the nanoparticle-resin composite material. A plurality of these silane compounds can be blended at an arbitrary ratio according to the siloxane compound to be used.

  In the present invention, a siloxane compound having no reactive functional group can be included for the purpose of adjusting the hardness of the finally obtained nanoparticle-resin composite material. Examples of the siloxane compound having no reactive functional group include diorganopolysiloxane. Particularly, a phenyl group is preferably contained because the refractive index of the nanoparticle-resin composite material is increased. The addition amount of the siloxane compound having no reactive functional group is preferably 80 parts by weight or less when the total of the siloxane compound [1] and the siloxane compound [2] is 100 parts by weight. Further, the molecular weight of the siloxane compound having no reactive functional group may be selected within a range that does not impair the fluidity of the nanoparticle-resin composite precursor before the siloxane compound is crosslinked.

  In the present invention, the “visible light region” means a range of light having a wavelength of 380 nm to 750 nm. “Transparent” means that “inorganic nanoparticles are not aggregated in the siloxane crosslinked product” or “inorganic nanoparticles are uniformly dispersed in the siloxane compound”. "In the state" means that the light transmittance measured at a wavelength of 400 nm with a light path length of 0.5 mm is 80% or more based on the light transmittance measurement method described later. To do.

The viscosity of the siloxane compound is 1 × 10 ⁻² Pa · s to ¹ × 10 ¹ Pa · s, preferably 1 × 10 ⁻² Pa · s to 5 × 10 ⁰ Pa · s, more preferably 1 × 10 ^−2. Pa · s to 2.5 × 10 ⁰ Pa · s can be exemplified. The viscosity of the siloxane compound can be measured using, for example, a cone plate type rotary viscometer. When the viscosity of the siloxane compound is too high, fluidity may be impaired when the inorganic nanoparticles are filled, and it may be difficult to seal the light emitting element. Examples of the number average molecular weight of the siloxane compound include 2 × 10 ² to 2 × 10 ^4, and the molecular weight of the siloxane compound can be measured based on a method using GPC.

  In the present invention including the desirable forms and configurations described above, the nanoparticle-resin composite material is solid or gel. In addition, the nanoparticle-resin composite material being in a gel form is defined as having a flexibility and not being plastically deformed.

  In the present invention, for the purpose of maintaining heat resistance and light resistance, a known antioxidant or light stabilizer may be included in the nanoparticle-resin composite material.

The refractive index of the nanoparticle-resin composite material in the present invention can be adjusted based on the following concept. That is, the refractive index of a nanoparticle-resin composite material in which high-refractive-index inorganic nanoparticles are dispersed in a matrix (siloxane crosslinked product) is theoretically derived by Maxwell Garnet (CF Bohren and DR Huffman, See "Adsorpiton and Scattering of Light by Small Particles", John Wiley & Sons, New York, 1983, pp 213). And the dielectric constant of the whole nanoparticle-resin composite material can be calculated | required from following formula (1), when the inorganic nanoparticle is disperse | distributing uniformly in a siloxane crosslinked product. here,
ε _av : Average relative permittivity (relative permittivity of the entire nanoparticle-resin composite material)
ε _p : Relative permittivity of spherical particles (inorganic nanoparticles) ε _m : Relative permittivity of matrix (siloxane crosslinked product) η: Volume filling rate of inorganic nanoparticles.

Since the refractive index n is represented by n = ε ^1/2 , the refractive index of the entire nanoparticle-resin composite material (average) can be obtained using the formula (1). For example, when anatase-type titanium oxide nanoparticles having a refractive index of 2.5 are used as inorganic nanoparticles and dispersed in a siloxane crosslinked product having a refractive index of 1.5, the volume filling factor η of the inorganic nanoparticles is Is 0.06 and 0.15, the refractive index of the entire nanoparticle-resin composite material (average) is 1.55 and 1.63. Therefore, it is possible to adjust the refractive index of the whole nanoparticle-resin composite material by changing the volume filling rate η of the inorganic nanoparticles contained in the nanoparticle-resin composite material. Therefore, the constituent material of the inorganic nanoparticles may be selected in advance according to the target refractive index of the nanoparticle-resin composite material, and the volume filling rate η may be set. Here, the volume filling rate η of the inorganic nanoparticles can be obtained from the amount of the residue (inorganic nanoparticles) after the nanoparticle-resin composite material is heated to burn the organic component. The change in heating weight can be measured by, for example, TG measurement. The volume filling factor of the inorganic nanoparticles in the finally obtained nanoparticle-resin composite material is preferably 0.01 to 0.4, for example.

Moreover, the light transmittance in the nanoparticle-resin composite material based on Rayleigh scattering when the particle diameter is sufficiently smaller than the wavelength of light can be obtained from the following equations (2-1) and (2-2). . here,
C _sca : Scattering cross section (unit: nm ² )
α _sca : extinction rate (unit: nm ^-1 )
n _m : refractive index of matrix (siloxane crosslinked product) n _p : refractive index of spherical particles (inorganic nanoparticles) r: radius of spherical particles (inorganic nanoparticles) (= D _ave / 2)
η: Volume filling factor of inorganic nanoparticles λ: Wavelength of light in air η: Volume filling factor of inorganic nanoparticles.

  Therefore, for example, when anatase-type titanium oxide nanoparticles having a refractive index of 2.5 are used as inorganic nanoparticles and dispersed in a siloxane crosslinked product having a refractive index of 1.5, the volume filling factor η is 0. In order to be transparent at the thickness t = 0.5 mm of the portion through which the light of the nanoparticle-resin composite material passes, the particle size D of the inorganic nanoparticles must be 6 nm or less. When zirconium oxide nanoparticles having a refractive index of 2.2 are used as inorganic nanoparticles and dispersed in a siloxane crosslinked product having a refractive index of 1.5, when the volume filling factor η is 0.15, In order to be transparent at the thickness t = 0.5 mm of the part through which light of the nanoparticle-resin composite material passes, the particle size D of the inorganic nanoparticles must be 8 nm or less. Thus, it is desirable that the particle diameter D and the filling rate η of the inorganic nanoparticles are appropriately selected so as to obtain desired transparency depending on the refractive index of the matrix resin material used and the refractive index of the inorganic nanoparticles.

  In the method for producing a nanoparticle-resin composite material of the present invention, the surface of the inorganic nanoparticle is coated with an organic compound in a liquid phase. Specifically, first, inorganic nanoparticles are developed in an organic solvent, and then an organic compound is added. The organic solvent should just be what can dissolve an organic compound. The addition amount of the organic compound is desirably an excessive amount rather than an amount covering only one surface of the particle surface. Next, the mixture is subjected to treatment (dispersion treatment) using a known disperser. Thereby, the aggregate of inorganic nanoparticles is crushed. If the inorganic nanoparticles are synthesized in a liquid phase and are undried, the aggregation is gradual, so that it is easy to disintegrate and is suitable. Further, the organic compound is adsorbed on the surface of the inorganic nanoparticles during the treatment by the disperser. The temperature during the crushing and organic compound adsorption treatment is preferably between room temperature and 80 ° C. Thereafter, the inorganic nanoparticles coated with the organic compound are recovered as a dispersion or precipitate in which the inorganic nanoparticles are uniformly dispersed. The difference between the dispersion and the precipitate depends on the type of organic solvent used. It is also possible to add a poor solvent to the obtained dispersion and re-aggregate it, and collect it as a precipitate by centrifugation. In the case of collecting as a precipitate, the precipitate is separated by centrifugation and washing with an organic solvent for washing is repeated to remove excess organic compounds, followed by vacuum drying and collecting.

  In the method for producing a nanoparticle-resin composite material of the present invention, the mixing of the inorganic nanoparticles coated with the organic compound and the siloxane compound is specifically performed by one of the following two methods. Can do. That is, the first method is a method in which inorganic nanoparticles are dispersed in a good solvent common to the siloxane compound, and then the siloxane compound is added, stirred and mixed, and only the organic solvent is removed under a heating vacuum. . At this time, since the siloxane compound has a low vapor pressure, it hardly evaporates. The second method is a method in which a dry powder of inorganic nanoparticles is directly mixed with a siloxane compound and uniformly mixed using a known kneader. Furthermore, the siloxane compound is cross-linked by heating, but the heating atmosphere can be an air atmosphere. Specifically, as a heating method, a method of holding at 150 ° C. for 5 hours using a known oven is used. It can be illustrated.

In the present invention, the linear expansion coefficient of the nanoparticle-resin composite material can be measured using a thermomechanical analyzer (TMA). In the range of 20 ° C. to 150 ° C., the value of the linear expansion coefficient of the nanoparticle-resin composite material is preferably 1.5 × 10 ⁻⁴ or less. As a result, for example, during operation of the light-emitting element assembly, even when the nanoparticle-resin composite material reaches a high temperature due to heat generation of the light-emitting element, it is surely prevented that problems occur in the light-emitting element assembly. can do.

  Examples of the light emitting element in the light emitting element assembly of the present invention include a light emitting diode (LED) and a semiconductor laser. Here, when the light emitting element is configured by a light emitting diode, for example, a red light emitting diode that emits red (for example, wavelength 640 nm), a green light emitting diode that emits green (for example, wavelength 530 nm), and blue (for example, wavelength 450 nm). Blue light emitting diodes that emit light, and white light emitting diodes (for example, light emitting diodes that emit white light by combining ultraviolet light or blue light emitting diodes and phosphor particles). The light emitting diode may have a so-called face-up structure or a flip chip structure. That is, the light-emitting diode includes a substrate and a light-emitting layer formed on the substrate, and may have a structure in which light is emitted from the light-emitting layer to the outside, or light from the light-emitting layer passes through the substrate. It is good also as a structure radiate | emitted outside. More specifically, the light emitting diode (LED) is formed on, for example, a first cladding layer and a first cladding layer made of a compound semiconductor layer having a first conductivity type (for example, n-type) formed on a substrate. The active layer, and a second clad layer stack structure comprising a compound semiconductor layer having a second conductivity type (for example, p-type) formed on the active layer, and electrically connected to the first clad layer. One electrode and a second electrode electrically connected to the second cladding layer are provided. The layer constituting the light emitting diode may be made of a known compound semiconductor material depending on the emission wavelength. In the light emitting device assembly of the present invention, light from the light emitting device is emitted to the outside through the filling material and the sealing member made of the nanoparticle-resin composite material, or alternatively, the nanoparticle-resin composite. The light passes through a sealing member made of a material and is emitted to the outside.

In the light emitting element assembly according to the first aspect of the present invention, the sealing member is preferably made of a material having a high refractive index from the viewpoint of suppressing light reflection at the interface with the filling material. Here, as a material with a high refractive index, for example, a product name Prestige (refractive index: 1.74) of Seiko Optical Products Co., Ltd., a product name of ULTIMAX V AS 1.74 (refractive index: 1.74) of Showa Optical Co., Ltd. ), A plastic material having a high refractive index such as Nikon Essilor's trade name NL5-AS (refractive index: 1.74); glass material NBFD11 (refractive index n: 1.78) manufactured by HOYA Corporation, M-NBFD82 (refractive) An optical glass such as M-LAF81 (refractive index n = 1.731); KTiOPO ₄ (refractive index n: 1.78), lithium niobate [LiNbO ₃ ] (refractive index n: 2.1). And 23) inorganic dielectric materials.

  Alternatively, in the light emitting element assembly according to the first aspect of the present invention, as a material constituting the sealing member, specifically, an epoxy resin, a silicone resin, an acrylic resin, a polycarbonate resin, a spiro compound, Polymethyl methacrylate and its copolymer, diethylene glycol bisallyl carbonate (CR-39), (brominated) polymer of urethane-modified monomer of bisphenol A mono (meth) acrylate and its copolymer, polyester resin (for example, polyethylene) Terephthalate resin, polyethylene naphthalate resin), unsaturated polyester, acrylonitrile-styrene copolymer, vinyl chloride resin, polyurethane resin, and polyolefin resin. In addition, the sealing member should just be comprised from at least 1 type of material of these materials. Moreover, when heat resistance is considered, an aramid resin can be used. In this case, the upper limit of the heating temperature when forming an antifouling layer made of a fluororesin described later is 200 ° C. or higher, and the degree of freedom in selecting the fluororesin can be increased.

  The light-emitting element assembly according to the first aspect or the second aspect of the present invention can be used in any field where light emission is required. Examples of such a field include a backlight of a liquid crystal display device [ There are known two types including a planar light source device and a direct type and an edge light type (also called a side light type)], a lamp and a lamp (for example, a headlight) in transportation means such as an automobile, a train, a ship, and an aircraft. ), Tail lights, high-mount stop lights, small lights, turn signal lamps, fog lights, room lights, meter panel lights, light sources built into various buttons, destination indicators, emergency lights, emergency exit lights, etc.), architecture Various kinds of lamps and lights on objects (outside lights, interior lights, lighting equipment, emergency lights, emergency exit guide lights, etc.), street lights, traffic lights, signs, machines, devices, etc. Kicking various display lamps, it can be mentioned lighting fixture and lighting unit in the tunnel and underground passage or the like.

  Moreover, as an application field of the optical material of the present invention, fields such as an optical lens and an optical waveguide can be exemplified in addition to the filling material for the light emitting element assembly and the light emitting element assembly.

An antifouling layer made of a fluorine-based resin may be formed on the surface of the sealing member. The thickness of the antifouling layer is not particularly limited, from the transparency of the ^{relationship, 5 × 10 -10 m~5 × 10} -8 m, preferably ^{1 × 10 -9 m~2 × 10 -8} m It is desirable to be.

The fluororesin constituting the antifouling layer basically has only to have a perfluoropolyether group and preferably an alkoxysilano group, and there are essentially no restrictions on the molecular structure other than the perfluoropolyether group. Not really. However, in practice, there is a restriction based on a request from the viewpoint of ease of synthesis, that is, feasibility. Specifically, an alkoxysilane compound having a perfluoropolyether group represented by the following general formula (A) can be exemplified as the fluororesin constituting the antifouling layer. In the general formula (A), R _f represents a perfluoropolyether group, R ¹ is a divalent atom or group, R ² represents an alkylene group, R ³ represents an alkyl group, the value of j is 1 or 2.

R _f {COR ¹ -R ² -Si (OR ³ ) ₃ } _j (A)

The molecular weight of the alkoxysilane compound represented by the general formula (A) is not particularly limited, but is 4 × 10 ² to 1 × 10 ⁴ , preferably 5 × 10 in terms of number average molecular weight from the viewpoints of stability and ease of handling. ² to 4 × 10 ³ .

The perfluoropolyether group R _f is a monovalent or divalent perfluoropolyether group, and the specific structure of such a perfluoroether group is shown below, but is not limited thereto. Here, in the structural formulas (B), (C), (D), and (E), p and q are preferably in the range of 1 to 50, and each of n, l, m, and k is 1 or more. Indicates an integer. Moreover, it is preferable that the value of m / l exists in the range of 0.5-2.0.

In j = 2, the following structural formula (B) can be exemplified as the perfluoropolyether group R _f in the general formula (A).

_{-CF 2 - (OC 2 F 4} ) p - (OCF 2) q -OCF 2 - (B)

Moreover, in j = 1, the following structural formula (C), structural formula (D), and structural formula (E) can be illustrated as perfluoropolyether group _Rf in general formula (A). However, it is not necessary that all the hydrogen atoms of the alkyl group are substituted with fluorine atoms, and hydrogen atoms may be partially contained.

F (CF ₃ CF ₂ CF ₂ ) _n (C)
CF ₃ (OCF (CF ₃ ) CF ₃ ) _m (OCF ₂ ) _l (D)
F- (CF (CF ₃ ) CF ₂ ) _k (E)

  Moreover, as a material constituting the antifouling layer containing a perfluoropolyether group, for example, a perfluoropolyether having a polar group at the terminal (see JP-A-9-127307), a perfluoropolyether group having a specific structure An antifouling film-forming composition containing an alkoxysilane compound having a surface roughness (see JP-A-9-255919), a surface modifier obtained by combining an alkoxysilane compound having a perfluoropolyether group with various materials (special Kaihei 9-326240, JP-A-10-26701, JP-A-10-120442, and JP-A-10-148701 can also be used.

R ¹ represents a divalent atom or group, and is a linking group between R ² and the perfluoropolyether group R _f, and is not particularly limited. A group is preferred. R ² is a hydrocarbon group, preferably having 2 to 10 carbon atoms. Specific examples of R ² include an alkylene group such as a methylene group, an ethylene group, and a propylene group, and a phenylene group. R ³ is an alkyl group constituting an alkoxy group, usually having 3 or less carbon atoms, that is, an isopropyl group, a propyl group, an ethyl group, or a methyl group. However, the carbon number may be 4 or more.

  In order to form the antifouling layer, a fluororesin (for example, an alkoxysilane compound represented by the general formula (A)) is usually used after diluted in a solvent. Although it does not specifically limit as this solvent, In using, it is necessary to determine in consideration of the stability of a composition, the wettability with respect to the surface of a sealing member, volatility, etc. Specific examples include alcohol solvents such as ethyl alcohol, ketone solvents such as acetone, hydrocarbon solvents such as hexane, and the like. Further, these solvents may be used alone or as a mixture of two or more thereof. Can be used as

  Alternatively, the solvent that dissolves the fluororesin may be determined in consideration of the stability of the composition in use, the wettability with respect to the surface of the sealing member, the volatility, etc., for example, a fluorinated hydrocarbon solvent. Is used. The fluorinated hydrocarbon solvent is a compound in which part or all of the hydrogen atoms of a hydrocarbon solvent such as an aliphatic hydrocarbon, a cyclic hydrocarbon, and an ether are substituted with a fluorine atom. For example, trade names ZEORORA-HXE (boiling point 78 ° C.), perfluoroheptane (boiling point 80 ° C.), perfluorooctane (boiling point 102 ° C.) manufactured by Nippon Zeon Co., Ltd., trade names H-GALDEN-ZV75 manufactured by Outdmont Corporation (Boiling point 75 ° C), H-GALDEN-ZV85 (boiling point 85 ° C), H-GALDEN-ZV100 (boiling point 95 ° C), H-GALDEN-C (boiling point 130 ° C), H-GALDEN-D (boiling point) 178 ° C) hydrofluoropolyether, SV-110 (boiling point 110 ° C), SV-135 (boiling point 135 ° C) and other perfluoropolyethers, FC series manufactured by Sumitomo 3M Examples include alkanes. Among these fluorinated hydrocarbon solvents, as a solvent for dissolving the fluorine compound of the general formula (A), a boiling point of 70 to 240 is obtained in order to obtain a uniform and uniform antifouling layer with a uniform film thickness. It is preferable to select one in the range of ° C, among which hydrofluoropolyether (HFPE) or hydrofluorocarbon (HFC) is selected, and one of these is used alone or two or more of them are used in combination. If the boiling point is too low, for example, coating unevenness tends to occur. On the other hand, if the boiling point is too high, drying tends to be difficult and formation of a uniform antifouling layer tends to be difficult. HFPE or HFC has excellent solubility in the fluorine-based compound represented by the general formula (A), and an excellent coated surface can be obtained.

  Then, a fluorine resin (for example, an alkoxysilane compound represented by the general formula (A)) diluted in a solvent is applied to the surface of the sealing member, and the solvent is volatilized by heating, for example, and sealing The antifouling layer can be formed on the surface of the sealing member by causing a bond between the material constituting the member and the fluororesin constituting the antifouling layer. As a coating method, various methods used in normal coating operations can be applied, but spin coating, spray coating, and the like can be preferably used. Further, from the viewpoint of workability, a method of impregnating a liquid such as paper or cloth and applying it may be employed. The heating temperature may be selected in consideration of the heat resistance of the sealing member. For example, when polyethylene terephthalate resin is used as the sealing member, a range of 30 to 80 ° C. is appropriate.

  The alkoxysilane compound represented by the general formula (A) includes a fluorine-based compound in the molecule, thereby having water repellency and improving stain resistance. Therefore, by forming an antifouling layer containing an alkoxysilane compound having a perfluoropolyether group represented by the general formula (A), the surface of the sealing member is further imparted with characteristics such as wear resistance and antifouling property. can do.

The catalyst for promoting the reaction between the material constituting the sealing member and the material constituting the antifouling layer is at least selected from the group consisting of acids, bases, phosphate esters, and acetylacetone. It is preferable to add one kind of material to the material constituting the antifouling layer. Specific examples of the catalyst include acids such as hydrochloric acid, bases such as ammonia, and phosphate esters such as dilauryl phosphate. Examples of the addition amount of the catalyst include 1 × 10 ⁻³ mmol / liter to 1 mmol / liter. In the case of adding an acid or a base, the addition of a carbonyl compound such as acetylacetone increases the reactivity, so it is recommended to add a carbonyl compound to the composition for forming the antifouling layer. The amount of such a carbonyl compound added can be about 1 × 10 ⁻¹ mmol / liter to 1 × 10 ² mmol / liter. Thus, by adding a catalyst, a strong bond can be formed between the sealing member and the antifouling layer even when the heating (drying) temperature is lowered. As a result, the manufacturing process becomes advantageous, and the selection range of the material constituting the sealing member is expanded.

  According to the nanoparticle-resin composite material of the present invention or the method for producing the same, by coating the surface of the inorganic nanoparticle with a predetermined organic compound, the inorganic nanoparticle is uniformly dispersed without agglomerating in the siloxane compound. It is possible to provide a nanoparticle-resin composite material that is transparent, has a high refractive index, has a small linear expansion coefficient even at a high temperature, and has good light resistance. In the present invention, the refractive index of the nanoparticle-resin composite material can be controlled based on the type of inorganic nanoparticles and the volume filling factor, and a refractive index of 1.55 or more is achieved in the visible light region. can do. Further, according to the light emitting device assembly of the present invention, it is filled with a nanoparticle-resin composite material that is transparent, has a high refractive index, has a low coefficient of linear expansion even at high temperatures, and has good light resistance. By using it as a material (encapsulation material), a light emitting element assembly having high light extraction efficiency and excellent light resistance and durability can be provided. Moreover, in this invention, since a siloxane compound is bridge | crosslinked, a nanoparticle-resin composite material is a solid form or a gel form. Accordingly, during the operation of the light emitting device assembly of the present invention, even when the temperature of the nanoparticle-resin composite material becomes high due to heat generation of the light emitting device, the fluidity of the nanoparticle-resin composite material is increased and the light emitting device assembly is increased. The phenomenon that the light emitting element flows out does not occur, and the long-term reliability of the light emitting element assembly can be ensured.

  Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings, but the present invention is not limited to these embodiments.

Example 1 relates to a nanoparticle-resin composite material of the present invention and a method for producing the same. The nanoparticle-resin composite material of Example 1 or Example 2 described later is formed by dispersing inorganic nanoparticles in a siloxane cross-linked product, and the inorganic nanoparticles are coated with an organic compound and transparent in the visible light range. And a nanoparticle-resin composite material having a refractive index of 1.55 or more. The siloxane cross-linked product is formed based on cross-linking of a siloxane compound having a siloxane bond and a reactive functional group, and the organic compound forms a covalent bond or an ionic bond with the surface of the inorganic nanoparticle. And an organic group having an affinity for the siloxane compound, and the molecular weight is 1 × 10 ³ or less. In addition, the method for producing the nanoparticle-resin composite material of Example 1 or Example 2 described later is formed by dispersing inorganic nanoparticles in a siloxane crosslinked product, and the inorganic nanoparticles are coated with an organic compound. It is transparent in the visible light region and has a refractive index of 1.55 or more,
The siloxane cross-linked product is formed on the basis of cross-linking of a siloxane compound having a siloxane bond and containing a reactive functional group,
The organic compound has a functional group that forms a covalent bond or an ionic bond with the surface of the inorganic nanoparticle, and an organic group that has an affinity for the siloxane compound, and has a molecular weight of 1 × 10 ³ or less. It is a manufacturing method. And
(A) After the inorganic nanoparticles and the organic compound are dispersed in the liquid phase and the surface of the inorganic nanoparticles is coated with the organic compound,
(B) mixing inorganic nanoparticles coated with an organic compound and a siloxane compound;
(C) the siloxane compound is crosslinked by heating, thereby forming a siloxane crosslinked product;
It has a process.

  Hereinafter, the nanoparticle-resin composite material of Example 1 and the production method thereof will be described in detail. More specifically, in Example 1, the organic compound is a carboxylic acid containing an aryloxy group. 4-phenoxybenzoic acid, and the siloxane compound [1] is a phenyl group-based Pt vinylsiloxane complex added to form a methylphenylsiloxane having addition-reactive carbon-carbon double bonds at both ends. Siloxane compound [2] was methylphenylsiloxane having hydrogen atoms bonded to Si atoms. The chemical formula of methylphenylsiloxane having an addition-reactive carbon-carbon double bond at both ends is shown in the following chemical formula (11), and the chemical formula of methylphenylsiloxane having a hydrogen atom bonded to an Si atom is expressed by the following chemical formula ( 12), and the chemical formula of the resulting siloxane crosslinked product is shown in the following chemical formula (13). In the chemical formula (13), “a” is an arbitrary integer.

One gram of ZrO ₂ nanoparticles having a particle diameter of 5 nm synthesized by the sol-gel method was mixed in 10 ml of MEK, 1 gram of 4-phenoxybenzoic acid was added thereto, and the mixture was stirred at room temperature using a disper. Next, 40 ml of ethanol was added, followed by centrifugation to collect a precipitate. After adding 10 ml of MEK to this precipitate and crushing with a disper, 40 ml of ethanol was added, and inorganic nanoparticles were precipitated again by centrifugation, and collected as a precipitate. After repeating this washing and centrifuging operation three times, the precipitate was collected and dried under vacuum to obtain ZrO ₂ nanoparticles coated with 4-phenoxybenzoic acid. In the following description, the expression that the particle diameter of the inorganic nanoparticles is “D” nm is used. This expression is expressed when the average value of the particle diameter of the inorganic nanoparticles is D _ave and the standard deviation is σ. , D _ave + 2σ does not exceed “D” nm.

Next, a predetermined amount of this ZrO ₂ nanoparticle is added to toluene, and the ZrO ₂ nanoparticle is dispersed in toluene with a disper. Further, both ends are adjusted so that the volume filling rate of ZrO ₂ nanoparticle becomes 10%. Is added with methylphenylsiloxane having an addition-reactive carbon-carbon double bond (n _D = 1.53, viscosity = 250 mPa · s), and further, a platinum group catalyst Pt vinylsiloxane complex is converted to methylphenylsiloxane. On the other hand, 10 ppm was added on the basis of Pt weight, and mixed uniformly with a stirrer. And toluene was removed from this liquid mixture using the evaporator (setting temperature 40 degreeC). Thus, a mixture [1] of ZrO ₂ nanoparticles as inorganic nanoparticles coated with 4-phenoxybenzoic acid as an organic compound and methylphenylsiloxane as a siloxane compound [1] to which a platinum group catalyst is added. Could get.

On the other hand, a predetermined amount of these ZrO ₂ nanoparticles are added to toluene, and the ZrO ₂ nanoparticles are dispersed in toluene with a disper. Further, the ZrO ₂ nanoparticles are added to Si atoms so that the volume filling rate of ZrO ₂ nanoparticles becomes 10%. Methylphenylsiloxane having a bonded hydrogen atom (n _D = 1.52, viscosity = 400 mPa · s) was added and mixed uniformly with a stirrer. And toluene was removed from this liquid mixture using the evaporator (setting temperature 40 degreeC). Thus, a mixture [2] of ZrO ₂ nanoparticles as inorganic nanoparticles coated with 4-phenoxybenzoic acid as an organic compound and methylphenylsiloxane as a siloxane compound [2] could be obtained.

  Next, the mixture [1] and the mixture [2] were mixed at a weight ratio of 1: 1. Note that a mixture of the mixture [1] and the mixture [2] is referred to as a nanoparticle-resin composite material precursor. Then, after stirring, the mixture is degassed and heated in the atmosphere at 150 ° C. for 5 hours to crosslink the siloxane compound [1] and the siloxane compound [2] to form a siloxane crosslinked product. A resin composite material could be obtained.

  The refractive index of the obtained nanoparticle-resin composite material precursor was measured using a well-known Abbe refractometer (manufactured by ATAGO, model number NAR-4T). The measurement wavelength was D line. In addition, the light transmittance of the nanoparticle-resin composite material, in which the nanoparticle-resin composite material precursor is sealed in a 0.5 mm thick quartz cell and heated and cured in air at 150 ° C. for 5 hours, is measured. The measurement was performed using a well-known UV-visible spectrophotometer (manufactured by Hitachi High-Tech: model number U-3410).

  The refractive index measured by the D line of the nanoparticle-resin composite material precursor was 1.59. Moreover, although the measurement result of the light transmittance of a nanoparticle-resin composite material is shown in FIG. 1, the nanoparticle-resin composite material of Example 1 has a light transmittance of 85% or more in the visible light region with a wavelength of 380 nm to 750 nm. showed that. Then, a light-emitting element assembly in Example 3 described later (the light-emitting element is made of a blue light-emitting diode having an emission wavelength of 455 nm) was prototyped, and the luminance was measured. As a result, the luminance was improved by 10% based on the conventional light emitting device assembly (having the sealing member 114 having a refractive index of 1.5) shown in FIG. The conventional light emitting device assembly (having the sealing member 114 having a refractive index of 1.5) shown in FIG. 3 is hereinafter referred to as a conventional product.

  In addition, the refractive index in the Example described below is also a value measured by the D-line, and the light transmittance is a value measured in a visible light region having a wavelength of 380 nm to 750 nm using a quartz cell having an optical path length of 0.5 mm. It is.

  As modifications of Example 1, Example 1-A to Example 1-C described below were performed. The organic compounds used in Example 1-A to Example 1-C are as follows. The same siloxane compound [1], siloxane compound [2], and platinum group catalyst as in Example 1 were used as the siloxane compound [1], siloxane compound [2], and platinum group catalyst. Table 1 shows the refractive index, light transmittance, state of the obtained nanoparticle-resin composite material precursor or nanoparticle-resin composite material, and the luminance improvement rate in the light-emitting element assembly.

[Organic compounds]
Example 1: 4-phenoxybenzoic acid which is a carboxylic acid containing an aryloxy group In Table 1, the symbol "1" is shown in the column of the organic compound.
Example 1-A: 4-phenylbutyric acid which is a carboxylic acid containing an aryl group In Table 1, the symbol “1-A” is shown in the column of the organic compound.
Example 1-B: Diphenylphosphinic acid which is a phosphinic acid containing an aryl group In Table 1, the symbol “1-B” is shown in the column of the organic compound.
Example 1-C: 4-Phenylbutyltrichlorosilane... In Table 1, the symbol “1-C” is shown in the column of the organic compound.
Example 2: Oleic acid which is a carboxylic acid containing an olefin chain In Table 1, the symbol "2" is shown in the column of the organic compound.

  Further, in Example 1 and Examples 1-A to 1-C, the platinum group catalyst may be added to the siloxane compound [2] instead of the siloxane compound [1]. No difference was observed in the properties of the obtained nanoparticle-resin composite material.

The second embodiment is a modification of the first embodiment. Hereinafter, although the nanoparticle-resin composite material of Example 2 and the manufacturing method thereof will be specifically described, more specifically, in Example 2, the organic compound is a carboxylic acid containing an olefin chain. A certain oleic acid, siloxane compound [1] is added with a platinum group-based Pt vinylsiloxane complex, an addition reactive carbon-carbon double bond at both ends, and a part of the side chain is poly. The methyl phenyl siloxane substituted with an ether group was used, and the siloxane compound [2] was a methyl phenyl siloxane having a hydrogen atom bonded to a Si atom and a part of the side chain substituted with a polyether group .

One gram of ZrO ₂ nanoparticles having a particle size of 5 nm synthesized by the sol-gel method was mixed in 10 ml of toluene, 1 gram of oleic acid was added thereto, and the mixture was stirred at room temperature using a disper. Next, 40 ml of ethanol was added, followed by centrifugation to collect a precipitate. 10 ml of toluene was added to this precipitate and dispersed with a disper, 40 ml of ethanol was added, and inorganic nanoparticles were precipitated again by centrifugation, and collected as a precipitate. After this washing / centrifugation operation was repeated three times, the precipitate was collected and dried under vacuum to obtain ZrO ₂ nanoparticles coated with oleic acid.

Next, a predetermined amount of the ZrO ₂ nanoparticles are added to toluene, and the ZrO ₂ nanoparticles are dispersed in toluene with a disper. Further, both ends of the ZrO ₂ nanoparticles are adjusted so that the volume filling rate of the ZrO ₂ nanoparticles becomes 14%. And methylphenylsiloxane (n _D = 1.48, viscosity = 500 mPa · s) having an addition-reactive carbon-carbon double bond and a part of the side chain substituted with a polyether group, and platinum 10 ppm of Pt vinylsiloxane complex, which is a group catalyst, was added to methylphenylsiloxane based on the weight of Pt and mixed uniformly with a stirrer. And toluene was removed from this liquid mixture using the evaporator (setting temperature 40 degreeC). Thus, a mixture [1] of ZrO ₂ nanoparticles as inorganic nanoparticles coated with oleic acid as an organic compound and methylphenylsiloxane as a siloxane compound [1] to which a platinum group catalyst is added is obtained. I was able to.

On the other hand, a predetermined amount of the ZrO ₂ nanoparticles are added to toluene, the ZrO ₂ nanoparticles are dispersed in toluene with a disper, and the volume filling factor of the ZrO ₂ nanoparticles is 14%. Methylphenylsiloxane (N _D = 1.48, viscosity = 1000 mPa · s) having a bonded hydrogen atom and a part of the side chain substituted with a polyether group was added and mixed uniformly with a stirrer. And toluene was removed from this liquid mixture using the evaporator (setting temperature 40 degreeC). Thus, a mixture [2] of ZrO ₂ nanoparticles as inorganic nanoparticles coated with oleic acid as an organic compound and methylphenylsiloxane as a siloxane compound [2] could be obtained.

  Next, the mixture [1] and the mixture [2] were mixed at a weight ratio of 1: 1. Then, after stirring, the foam is degassed, and the nanoparticle-resin composite material precursor is heated in the air at 150 ° C. for 5 hours to crosslink the siloxane compound and form a siloxane cross-linked product. -A resin composite material could be obtained.

  The refractive index of the nanoparticle-resin composite material precursor was 1.57, and the light transmittance was 85% or more in the visible light region. In addition, the luminance of the light emitting element assembly composed of the blue light emitting semiconductor elements was improved by 7% based on the conventional product. The results of Example 2 are summarized in Table 1 below.

[Comparative Example 1]
In Comparative Example 1, a nanoparticle-resin composite material was obtained by treating under the same conditions as in Example 1 except that no organic compound was used. In the obtained nanoparticle-resin composite material, the ZrO ₂ nanoparticles were remarkably aggregated, the transmittance was 1% or less in the entire visible light region, and the refractive index was not measurable.

Example 3 relates to the light emitting device assembly according to the first aspect of the present invention, the filling material for the light emitting device assembly of the present invention, and the optical material of the present invention. The light-emitting element assembly of Example 3 whose schematic cross-sectional view is shown in FIG.
(A) Light emitting element (light emitting diode) 12,
(B) a sealing member 14 for sealing the light emitting element, and
(C) a filling material 13 filled in a gap existing between the light emitting element 12 and the sealing member 14;
It has. The filling material (filling material for the light emitting element assembly) or the optical material is composed of the nanoparticle-resin composite material 13A based on any one of the first and second embodiments.

  More specifically, the light-emitting element assembly includes a reflective cup 11 having a concave portion (corresponding to a gap), a light-emitting element 12 disposed in the concave portion of the reflective cup 11, and the light-emitting element 12 sealed. As a lid for the concave portion of the reflective cup 11 so as to enclose the filling material 13 composed of the nanoparticle-resin composite material 13A filling the concave portion of the reflective cup 11 and the light emitting element 12 and the nanoparticle-resin composite material 13A. It is comprised from the sealing member 14 produced from the arrange | positioned bullet-shaped transparent material (for example, polycarbonate resin of refractive index 1.6).

  As described above, according to the light emitting element assembly of Example 3, by using the nanoparticle-resin composite material 13A that is transparent and has a high refractive index as the filling material (encapsulation material) 13, the light is emitted from the light emitting element 12. As a result, it is possible to prevent the reflected light from being totally reflected at the interface between the light emitting element 12 and the filling material 13 as much as possible, and to prevent the light from being totally reflected at the interface between the filling material 13 and the sealing member 14 as much as possible. The light extraction efficiency can be improved. In addition, since the nanoparticle-resin composite material 13A is solid or gel, even when the light-emitting element 12 reaches a high temperature due to operation, the fluidity of the nanoparticle-resin composite material 13A increases to emit light. The phenomenon of flowing out of the element assembly does not occur, and the long-term reliability of the light emitting element assembly can be ensured.

  When the light-emitting element assembly of Example 3 is used as a light source in a planar light source device (backlight) of a liquid crystal display device, when light is emitted exclusively from the light-emitting diode that is a light-emitting element along the z-axis direction, Brightness unevenness may occur in the light source device. As a means for avoiding the occurrence of such a phenomenon, a light emitting diode assembly in which a light extraction lens as a sealing member is attached to the light emitting diode is used as a light source, and light emitted from the light emitting diode is converted into a light extraction lens. A two-dimensional direction emission structure that is totally reflected on the top surface of the light and emitted mainly in the horizontal direction of the light extraction lens can be given.

  More specifically, as shown in the conceptual diagram of FIG. 2B, a light emitting element assembly in which a light extraction lens 20 is attached to a light emitting element (light emitting diode) 12 is used as a light source and emitted from the light emitting element 12. The emitted light is totally reflected at a part of the top surface 21 of the light extraction lens 20 and can be configured to emit light in a two-dimensional direction mainly emitted in the horizontal direction of the light extraction lens 20. In FIG. 2B, reference numeral 22 indicates the bottom surface of the light extraction lens 20, and reference numeral 24 indicates the side surface of the light extraction lens 20. A concave portion (gap) 23 is provided on the bottom surface 22 of the light extraction lens 20, and the light emitting element 12 is accommodated in the concave portion 23. Further, the recess 23 is filled with the filling material 13 made of the nanoparticle-resin composite material 13A. Reference numeral 24 is a substrate, and reference numeral 25 is a wiring that connects the light emitting element 12 and a wiring portion (not shown) provided on the substrate 24. Examples of the material constituting the light extraction lens 20 include the transparent material constituting the sealing member 14 described above.

Here, the light extraction lens 20 shown in FIG. 2B is a light extraction lens in Japanese Patent Application No. 2005-300117, which has a circular bottom surface 22, a side surface 24, and a top surface 21. A surface light source (light emitting element 12) having a finite size is disposed in the center. And assuming cylindrical coordinates (r, φ, z) with the center of the bottom surface 22 as the origin and the normal passing through the center of the bottom surface 22 as the z axis,
The top surface 21 totally reflects a part of the radiated light component having a polar angle smaller than the polar angle Θ _{0 at the} portion where the side surface 24 and the top surface 21 intersect, out of the half-total solid-angle radiation emitted from the surface light source. For an aspherical surface that is rotationally symmetric with respect to the z-axis,
The side surface 24 transmits the radiated light component having a polar angle larger than the polar angle Θ ₀ and the radiated light component totally reflected by the top surface 21 of the semi-full solid angle radiated light emitted from the surface light source. For an aspherical surface that is rotationally symmetric with respect to the z-axis,
In the function r = f _S (z) with z representing the side surface 24 made of an aspheric surface as a variable, when the z coordinate of the portion where the side surface 24 and the top surface 21 intersect is z ₁ , 0 ≦ z ≦ z ₁ is closed. The function r = f _S (z) increases monotonously when z decreases in the interval, and the absolute value | d ² r / dz ² | Have at least one.

  However, the light extraction lens is not limited to the light extraction lens 20 shown in FIG. 2B, and may be a light extraction lens having any configuration and structure.

  In addition, a light emitting element assembly in which an antifouling layer is formed on the surface of the sealing member 14 or the light extraction lens 20 can be provided.

  Specifically, as a fluorine-based resin, 2 parts by weight of an alkoxysilane compound having a perfluoropolyether group at both ends (average molecular weight is about 4000 and has the following chemical formula) is a fluorine-based solvent, and has a boiling point. Is dissolved in 200 parts by weight of 130 ° C hydrofluoropolyether (trade name H-GALDEN, manufactured by Solvay Solexis), and 0.08 part by weight of perfluoropolyether ester of phosphoric acid is added as a catalyst. After preparing a uniform solution, the mixture was further filtered with a membrane filter to obtain a composition for forming an antifouling layer. And after apply | coating the composition for antifouling layer formation on the surface of the sealing member 14 using a spray, it is made to dry at the temperature of 70 degreeC for 1 hour, and an antifouling layer is formed in the surface of the sealing member 14 A light emitting device assembly was obtained.

R _f {CONH—C ₃ H ₆ —Si (OCH ₂ CH ₃ ) ₃ } ₂

  After sprinkling corn starch on the sealing member 14 of the obtained light emitting device assembly and attempting to remove the corn starch with an air gun, the surface of the sealing member 14 was observed with an optical microscope. The corn starch was completely removed. .

  Alternatively, a light-emitting element assembly was obtained in the same manner as described above except that a resin having the following chemical formula (average molecular weight of about 2000) was used as the fluorine-based resin. After sprinkling corn starch on the sealing member 14 of the obtained light emitting device assembly and attempting to remove the corn starch with an air gun, the surface of the sealing member 14 was observed with an optical microscope. The corn starch was completely removed. .

_{R f = -CH 2 CF 2 (} OC 2 F 4) p (OCF 2) q OCF 2 -

  Furthermore, a resin having the following chemical formula (average molecular weight of about 650) was used as the fluorine-based resin, and a light-emitting element assembly was obtained in the same manner as described above except that. After sprinkling corn starch on the sealing member 14 of the obtained light emitting device assembly and attempting to remove the corn starch with an air gun, the surface of the sealing member 14 was observed with an optical microscope. The corn starch was completely removed. .

CF ₃ (CF ₂ ) ₈ CH ₂ Si (OC ₂ H ₅ ) ₃

Example 4 relates to the light emitting device assembly according to the second aspect of the present invention, the filling material for the light emitting device assembly of the present invention, and the optical material of the present invention. A schematic cross-sectional view of the light-emitting element assembly of Example 4 is the same as FIG. 3 showing a schematic cross-sectional view of a conventional light-emitting element assembly. That is, the light-emitting element assembly of Example 4 whose schematic cross-sectional view is shown in FIG.
(A) a light emitting element (light emitting diode) 12, and
(B) a sealing member 34 for sealing the light emitting element;
It has. The sealing member 34 or the optical material is made of the nanoparticle-resin composite material 13A based on any one of the first and second embodiments.

  More specifically, the light-emitting element assembly includes a reflective cup 11 having a concave portion (corresponding to a gap), a light-emitting element 12 disposed in the concave portion of the reflective cup 11, and the light-emitting element 12 sealed. It is comprised from the sealing member 34 arrange | positioned so.

  As described above, according to the light emitting element assembly of Example 4, the sealing member 34 was produced from the transparent nanoparticle-resin composite material 13A having a high refractive index and emitted from the light emitting element 12. As a result of preventing light from being totally reflected at the interface between the light emitting element 12 and the sealing member 34 as much as possible, light extraction efficiency can be improved.

  In addition, instead of the sealing member 34, a light-emitting diode assembly to which the light extraction lens described in Example 3 is attached, which is manufactured from the nanoparticle-resin composite material according to any of Examples 1 to 2, and You can also Further, the antifouling layer described in the third embodiment may be formed on the surface of the sealing member 34.

FIG. 1 is a graph showing the results of measuring the light transmittance of the nanoparticle-resin composite material obtained in Example 1 with a UV-visible spectrophotometer. 2A is a schematic cross-sectional view of the light-emitting element assembly of Example 3, and FIG. 2B is a schematic of the light-emitting element assembly of Example 3 provided with a light extraction lens. FIG. FIG. 3 is a schematic sectional view of Example 4 or a conventional light emitting device assembly.

DESCRIPTION OF SYMBOLS 11 ... Reflection cup, 12 ... Light emitting element, 13 ... Filling member, 13A ... Nanoparticle-resin composite material, 14 ... Sealing member, 20 ... Light extraction lens, 21. ..Top surface of light extraction lens, 22 ... Bottom surface of light extraction lens, 23 ... Recess, 24 ... Side surface of light extraction lens, 24 ... Substrate, 25 ... Wiring

Claims (2)

Inorganic nanoparticles are dispersed in the siloxane crosslinked product, the inorganic nanoparticles are coated with an organic compound, are transparent in the visible light region, and have a refractive index of 1.55 or more .
Organic compounds, carboxylic acid, phosphinic acid, phosphonic acid, sulfinic acid, sulfonic acid, and is at least one compound selected from the group consisting of thiol, and, the compound chosen is an aryl group, A method for producing a nanoparticle-resin composite material comprising an aryloxy group, an alkyl group or an olefin chain and having a molecular weight of 1 × 10 ³ or less,
(A) After the inorganic nanoparticles and the organic compound are dispersed in the liquid phase and the surface of the inorganic nanoparticles is coated with the organic compound,
(B) mixing inorganic nanoparticles coated with an organic compound and a siloxane compound;
(C) the siloxane compound is crosslinked by heating, thereby forming a siloxane crosslinked product;
With a process ,
The step (B)
(B-1) Inorganic nanoparticles coated with an organic compound and a siloxane compound [1] having an addition reactive carbon-carbon double bond to which a platinum group catalyst is added are mixed to obtain a mixture [1]. Obtaining step,
(B-2) mixing inorganic nanoparticles coated with an organic compound and a siloxane compound [2] having a hydrogen atom bonded to a silicon atom to obtain a mixture [2], and
(B-3) mixing the obtained mixture [1] and mixture [2],
Consisting of
In the said process (C), the manufacturing method of the nanoparticle-resin composite material which heats the mixed mixture [1] and mixture [2] .
Inorganic nanoparticles are dispersed in the siloxane crosslinked product, the inorganic nanoparticles are coated with an organic compound, are transparent in the visible light region, and have a refractive index of 1.55 or more.
The organic compound is at least one compound selected from the group consisting of carboxylic acid, phosphinic acid, phosphonic acid, sulfinic acid, sulfonic acid, and thiol, and the selected compound includes an aryl group, aryl group A method for producing a nanoparticle-resin composite material comprising an oxy group, an alkyl group or an olefin chain and having a molecular weight of 1 × 10 ³ or less,
(A) After the inorganic nanoparticles and the organic compound are dispersed in the liquid phase and the surface of the inorganic nanoparticles is coated with the organic compound,
(B) mixing inorganic nanoparticles coated with an organic compound and a siloxane compound;
(C) the siloxane compound is crosslinked by heating, thereby forming a siloxane crosslinked product;
With a process ,
The step (B)
(B-1) A step of obtaining a mixture [1] by mixing inorganic nanoparticles coated with an organic compound and a siloxane compound [1] having an addition-reactive carbon-carbon double bond,
(B-2) A step of obtaining a mixture [2] by mixing inorganic nanoparticles coated with an organic compound and a siloxane compound [2] having a hydrogen atom bonded to a silicon atom to which a platinum group catalyst is added. ,as well as,
(B-3) mixing the obtained mixture [1] and mixture [2],
Consisting of
In the said process (C), the manufacturing method of the nanoparticle-resin composite material which heats the mixed mixture [1] and mixture [2].

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