Ultraviolet-curable resin composition, method for manufacturing light-emitting device, and light-emitting device

Abstract

To provide an ultraviolet-curable resin composition which can be used for manufacturing an optical component transmitting light emitted from a light source and can make it difficult to cause deterioration in luminous efficiency due to an inorganic layer and the optical component in a light-emitting device.SOLUTION: The ultraviolet-curable resin composition contains an acrylic compound (A) and a photopolymerization initiator (B). The acrylic compound (A) contains an acrylic compound (A1) having a refractive index of 1.459 or less. The percentage of the acrylic compound (A1) to the acrylic compound (A) is 50 mass% or more. The ultraviolet-curable resin composition has a refractive index of 1.459 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an ultraviolet-curable resin composition, a method for manufacturing a light-emitting device, and a light-emitting device, and more particularly to an ultraviolet-curable resin composition for producing an optical component that transmits light emitted by a light source, a method for manufacturing a light-emitting device using this ultraviolet-curable resin composition, and a light-emitting device including this optical component. [Background technology]

[0002] Light-emitting devices such as organic electroluminescence (EL) light-emitting devices are used in lighting, displays, and other applications, and are expected to become more widespread in the future.

[0003] Among organic EL light-emitting devices, those known as top-emission types are configured, for example, by placing an organic EL element on a support substrate and placing a transparent substrate opposite the support substrate. In this case, light emitted by the organic EL element passes through the transparent substrate and is emitted to the outside.

[0004] When organic EL elements deteriorate due to moisture, dark spots, which do not emit light, may appear. Therefore, organic EL elements are covered with a transparent sealing material and a passivation layer made of a nitrogen compound to prevent moisture from entering the organic EL element from the outside (see Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-186850 Summary of the Invention [Problem to be solved by the invention]

[0006] Organic EL light-emitting devices are required to have not only suppression of dark spots but also high luminous efficiency. The inventors have found that providing an encapsulant and a passivation layer in an organic EL light-emitting device leads to a decrease in luminous efficiency, and that the decrease in luminous efficiency is particularly significant when the encapsulant is thin.

[0007] An object of the present invention is to provide an ultraviolet-curable resin composition that can be used to produce optical components that transmit light emitted by a light source and that can reduce the reduction in luminous efficiency caused by the inorganic layer and optical components in a light-emitting device; a method for producing a light-emitting device that uses this ultraviolet-curable resin composition; and a light-emitting device that includes optical components made of a cured product of this ultraviolet-curable resin composition. [Means for solving the problem]

[0008] According to one aspect of the present invention, there is provided an ultraviolet-curable resin composition for producing an optical component that transmits light emitted by a light source, the ultraviolet-curable resin composition comprising an acrylic compound (A) and a photopolymerization initiator (B), wherein the acrylic compound (A) comprises an acrylic compound (A1) having a refractive index of 1.459 or less, and the percentage of the acrylic compound (A1) relative to the acrylic compound (A) is 50 mass % or more.

[0009] A method for manufacturing a light emitting device according to one aspect of the present invention is a method for manufacturing a light emitting device including a light source, an optical component that transmits light emitted by the light source, and an inorganic layer, the optical component and the inorganic layer being overlapped with each other, the method comprising the steps of: molding the ultraviolet curable resin composition by an ink jet method; and irradiating the ultraviolet curable resin composition with ultraviolet light. and curing to form the optical component.

[0010] A light-emitting device according to one aspect of the present invention comprises a light source, an optical component and an inorganic layer that transmit light emitted by the light source, the optical component and the inorganic layer overlapping each other, and the optical component is a cured product of the ultraviolet-curable resin composition. [Effects of the Invention]

[0011] One aspect of the present invention has the advantage that when the ultraviolet-curable resin composition is used to fabricate an optical component of a light-emitting device, a decrease in luminous efficiency caused by the inorganic layer and the optical component in the light-emitting device can be made less likely to occur. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view showing a light-emitting device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will be described below.

[0014] According to this embodiment, the ultraviolet-curable resin composition (hereinafter also referred to as composition (X)) for producing an optical component that transmits light emitted from a light source contains an acrylic compound (A) and a photopolymerization initiator (B). The acrylic compound (A) contains an acrylic compound (A1) having a refractive index of 1.459 or less. The percentage of the acrylic compound (A1) relative to the acrylic compound (A) is 50% by mass or more.

[0015] Composition (X) is used to produce an optical component that transmits light emitted from a light source. The optical component is a component that transmits light emitted from a light source such as a light-emitting element in a device having an optical system (e.g., a light-emitting device 1). The optical component is, for example, an encapsulant 5 for a light-emitting element. The optical member is, for example, a thin film, more specifically, a film having a thickness of 2 μm to 50 μm, or 2 μm to 30 μm.

[0016] In this embodiment, an optical component, such as the encapsulant 5 of a light-emitting device 1, can be produced from the composition (X) (see FIG. 1). The light-emitting device 1 includes, for example, a light source, an optical component that transmits light emitted by the light source, and an inorganic layer, with the optical component and the inorganic layer overlapping. In particular, it is preferable to produce the encapsulant 5 of a light-emitting device 1 including a light-emitting element 4, an encapsulant 5 covering the light-emitting element 4, and a passivation layer 6, with the encapsulant 5 overlapping the passivation layer 6, from the composition (X). In this case, the encapsulant 5 is the optical component, the light-emitting element 4 is the light source, and the passivation layer 6 is the inorganic layer. In this case, a decrease in luminous efficiency due to the passivation layer 6 and the encapsulant 5 in the light-emitting device 1 can be prevented. This is thought to be because the acrylic compound (A1) contained in the composition (X) allows the encapsulant 5, which is a cured product of the composition (X), to have a refractive index that is appropriately lower than that of the passivation layer 6 made of an inorganic material. In other words, it is believed that the efficiency of extracting light emitted from the light-emitting element 4 to the outside is increased due to the interference of light within the passivation layer 6 and the sealing material 5 caused by the difference in refractive index between the sealing material 5 and the passivation layer 6.

[0017] In this specification, the refractive index of the acrylic compound (A1) refers to the refractive index at 25°C for light with a wavelength of 589.3 nm (the D line of sodium).

[0018] The refractive index of composition (X) is preferably 1.459 or less. In this case, the refractive index of the cured product of composition (X) can be equivalent to that of composition (X). Note that there may be some difference between the refractive index of composition (X) and the refractive index of the cured product due to curing shrinkage, etc. In this case, light reflection is particularly unlikely to occur in the inorganic layer and optical component.

[0019] In this specification, the refractive index of composition (X) refers to the refractive index at 25°C for light with a wavelength of 589.3 nm (sodium D line).

[0020] The refractive index of composition (X) is preferably 1.400 or more, more preferably 1.410 or more and 1.480 or less, and even more preferably 1.420 or more and 1.460 or less.

[0021] Furthermore, the refractive index of the cured product of composition (X) is preferably 1.510 or less. In this case, light reflection is particularly unlikely to occur in the inorganic layer and optical components. The refractive index of the cured product is also preferably 1.420 or more. The refractive index of the cured product is more preferably 1.430 or more and 1.505 or less, and even more preferably 1.440 or more and 1.499 or less.

[0022] In this specification, the refractive index of a cured product is the refractive index at 25°C for light with a wavelength of 587.6 nm (helium d-line).

[0023] The glass transition temperature of the cured product of composition (X) is preferably 80°C or higher. In other words, composition (X) preferably has the property of curing to form a cured product with a glass transition temperature of 80°C or higher. In this case, the cured product can have good heat resistance. Therefore, for example, when the cured product is subjected to a process that involves an increase in temperature, the cured product is less likely to deteriorate. Therefore, for example, when an inorganic layer is formed on an optical component made from composition (X) by a deposition method such as plasma CVD, the optical component is less likely to deteriorate even if the optical component is heated. The glass transition temperature of the cured product is more preferably 90°C or higher, and even more preferably 100°C or higher. This glass transition temperature of the cured product can be achieved by the composition of composition (X), which will be described in detail below.

[0024] The viscosity of composition (X) at 25°C is preferably 1 mPa·s or more and 30 mPa·s or less. In this case, composition (X) can be easily molded at room temperature by a method such as a casting method, and composition (X) can also be molded by an inkjet method. This viscosity is more preferably 25 mPa·s or less, even more preferably 20 mPa·s or less, and particularly preferably 15 mPa·s or less. It is also preferable that this viscosity is 5 mPa·s or more.

[0025] It is also preferable that the viscosity of composition (X) at 40°C is 1 mPa·s or more and 30 mPa·s or less. In this case, regardless of the viscosity of composition (X) at room temperature, it is possible to lower the viscosity by slightly heating composition (X). Therefore, by heating, composition (X) can be easily molded by a method such as a casting method, and composition (X) can also be molded by an inkjet method. Furthermore, since the viscosity of composition (X) can be lowered without significantly heating it, changes in the composition of composition (X) due to the volatilization of components in composition (X) can be made less likely. It is more preferable that this viscosity is 25 mPa·s or less, even more preferably 20 mPa·s or less, and particularly preferably 15 mPa·s or less. It is also preferable that this viscosity is 5 mPa·s or more.

[0026] The viscosity of composition (X) was measured using a rheometer at a shear rate of 100 s -1 The measurement is performed under the following conditions. As the rheometer, for example, a model DHR-2 manufactured by Anton Paar Japan can be used.

[0027] Such a low viscosity of composition (X) at 25°C or 40°C can be achieved by the composition of composition (X) described in detail below.

[0028] When the cured product of composition (X) has a thickness of 10 μm, the total light transmittance is preferably 90% or more. In this case, when the cured product is used as the encapsulant 5 in the light-emitting device 1, the extraction efficiency of light that passes through the encapsulant 5 and is emitted to the outside can be particularly improved. Such light transmittance of the cured product can also be achieved by the composition of composition (X), which will be described in detail below.

[0029] This embodiment will be described in more detail below.

[0030] 1. Structure of the light-emitting device First, the structure of the light emitting device 1 will be described. The light emitting device 1 includes a light source and an optical component that transmits light emitted by the light source. For example, the light emitting device 1 includes a light emitting element 4, and a sealant 5 and a passivation layer 6 that cover the light emitting element 4. In this case, the light emitting element 4 is the light source, the sealant 5 is the optical component, and the passivation layer 6 is an inorganic layer. The sealant 5 and the passivation layer 6 overlap each other.

[0031] The light-emitting element 4 includes, for example, a light-emitting diode. The light-emitting diode includes, for example, at least one of an organic EL element (organic light-emitting diode) and a micro light-emitting diode. When the light-emitting element 4 includes an organic light-emitting diode, the light-emitting device 1 including the light-emitting element 4 is, for example, an organic EL display. When the light-emitting element 4 includes a micro light-emitting diode, the light-emitting device 1 including the light-emitting element 4 is, for example, a micro LED display. Note that EL is an abbreviation for electroluminescence.

[0032] An example of the structure of light-emitting device 1 will be described with reference to Fig. 1. This light-emitting device 1 is a top-emission type. Light-emitting device 1 includes a support substrate 2, a transparent substrate 3 facing the support substrate 2 with a gap therebetween, a light-emitting element 4 on the surface of support substrate 2 facing the transparent substrate 3, and a passivation layer 6 and a sealing material 5 that cover the light-emitting element 4.

[0033] The support substrate 2 is made of, for example, but not limited to, a resin material. The transparent substrate 3 is made of a light-transmitting material. The transparent substrate 3 is, for example, a glass substrate or a transparent resin substrate. The light-emitting element 4 includes, for example, a pair of electrodes 41, 43 and an organic light-emitting layer 42 between the electrodes 41, 43. The organic light-emitting layer 42 includes, for example, a hole injection layer 421, a hole transport layer 422, an organic light-emitting layer 423, and an electron transport layer 424, which are stacked in the above order.

[0034] The light emitting device 1 includes a plurality of light emitting elements 4, and the plurality of light emitting elements 4 form an array 9 (hereinafter referred to as element array 9) on a support substrate 2. The element array 9 also includes a partition wall 7. The partition wall 7 is located on the support substrate 2 and separates two adjacent light emitting elements 4. The partition wall 7 is fabricated, for example, by molding a photosensitive resin material using a photolithography method. The element array 9 also includes connection wiring 8 that electrically connects the electrodes 43 and the electron transport layers 424 of adjacent light emitting elements 4. The connection wiring 8 is provided on the partition wall 7.

[0035] The passivation layer 6 is preferably made of silicon nitride or silicon oxide, and particularly preferably made of silicon nitride. In the example shown in FIG. 1 , the passivation layer 6 includes a first passivation layer 61 and a second passivation layer 62. The first passivation layer 61 is in direct contact with the element array 9 and covers the element array 9, thereby covering the light-emitting elements 4. The second passivation layer 62 is disposed on the opposite side of the first passivation layer 61 from the element array 9, and a gap is provided between the second passivation layer 62 and the first passivation layer 61. An encapsulant 5 is filled between the first passivation layer 61 and the second passivation layer 62. That is, the first passivation layer 61 is interposed between the light-emitting elements 4 and the encapsulant 5 covering the light-emitting elements 4.

[0036] Furthermore, a second sealing material 52 is filled between the second passivation layer 62 and the transparent substrate 3. The second sealing material 52 is made of, for example, a transparent resin material. The material of the second sealing material 52 is not particularly limited. The material of the second sealing material 52 may be the same as or different from the sealing material 5.

[0037] 2. Ultraviolet curable resin composition The ultraviolet-curable resin composition according to this embodiment (hereinafter also referred to as composition (X)) will be described.

[0038] The encapsulant 5 in the light-emitting device 1 having the structure exemplified above can be produced from the composition (X). That is, the composition (X) is used to produce the encapsulant 5 for the light-emitting element 4. In other words, the composition (X) is preferably a composition for producing an encapsulant, a composition for sealing a light-emitting element, or a composition for producing a light-emitting device.

[0039] As described above, composition (X) contains an acrylic compound (A) and a photopolymerization initiator (B). When composition (X) is irradiated with ultraviolet light, a photoradical polymerization reaction is initiated by the photopolymerization initiator (B), curing the acrylic compound (A), and thereby producing a cured product. The components of composition (X) are described in more detail below.

[0040] As described above, the composition (X) contains the acrylic compound (A). The acrylic compound (A) has one or more (meth)acryloyl groups in one molecule.

[0041] The viscosity of the entire acrylic compound (A) at 25°C is preferably 50 mPa·s or less. In this case, the acrylic compound (A) can particularly reduce the viscosity of the composition (X). The viscosity of the entire acrylic compound (A) is more preferably 30 mPa·s or less, even more preferably 25 mPa·s or less, and particularly preferably 20 mPa·s or less. The viscosity of the entire acrylic compound (A) is, for example, 3 mPa·s or more.

[0042] It is also preferable that the viscosity of the entire acrylic compound (A) at 40°C is 50 mPa·s or less. In this case, the acrylic compound (A) can particularly reduce the viscosity of the composition (X) when heated. The viscosity of the entire acrylic compound (A) is more preferably 30 mPa·s or less, even more preferably 25 mPa·s or less, and particularly preferably 20 mPa·s or less. In addition, the viscosity of the entire acrylic compound (A) is, for example, 3 mPa·s or more.

[0043] The compounds that the acrylic compound (A) may contain will be described below.

[0044] The acrylic compound (A) contains an acrylic compound (A1) having a refractive index of 1.459 or less. Therefore, the acrylic compound (A) can lower the refractive index of the cured product of the composition (X) and the encapsulant 5, thereby achieving a refractive index of 1.459 or less for the composition (X). The refractive index of the acrylic compound (A1) is more preferably 1.456 or less, and even more preferably 1.450 or less. The refractive index of the acrylic compound (A1) is, for example, 1.400 or more, or 1.420 or more.

[0045] The percentage of the acrylic compound (A1) relative to the acrylic compound (A) is 50% by mass or more. Therefore, the acrylic compound (A1) can effectively lower the refractive index of the cured product. The percentage of the acrylic compound (A1) is preferably 55% by mass or more. The percentage of the acrylic compound (A1) relative to the acrylic compound (A) is, for example, 100% by mass or less, or 85% by mass or more, preferably 80% by mass or less, and more preferably 70% by mass or less.

[0046] The boiling point of the acrylic compound (A1) is preferably 270°C or higher. In this case, the acrylic compound (A1) is less likely to volatilize from the composition (X) during storage or when the composition (X) is heated. Therefore, the storage stability of the composition (X) is less likely to be impaired. Furthermore, even if unreacted acrylic compound (A1) remains in the cured product and the sealant 5, outgassing due to the acrylic compound (A1) is less likely to occur from the cured product and the sealant 5. Therefore, voids due to outgassing are less likely to occur within the light-emitting device 1, for example, between the sealant 5 and the passivation layer 6. If voids are present in the light-emitting device 1, moisture may reach the light-emitting element 4 through the voids. However, if voids are less likely to occur, moisture is less likely to reach the light-emitting element 4, and the light-emitting element 4 is less likely to be deteriorated by moisture. Note that the boiling point is the boiling point at normal pressure, obtained by converting the boiling point under reduced pressure, and can be determined, for example, by the method described in Science of Petroleum, Vol. II, p. 1281 (1938). The boiling point of the acrylic compound (A1) is preferably 280°C or higher, more preferably 290°C or higher, and more preferably 300°C or higher. More than this is particularly preferable.

[0047] The viscosity of the acrylic compound (A1) at 25°C is preferably 25 mPa·s or less. In this case, the acrylic compound (A1) can reduce the viscosity of the composition (X). The viscosity of the acrylic compound (A1) at 25°C is more preferably 40 mPa·s or less, and even more preferably 25 mPa·s or less. The viscosity of the acrylic compound (A1) at 25°C is, for example, 1 mPa·s or more, and preferably 3 mPa·s or more.

[0048] The acrylic compound (A1) preferably contains a polyfunctional compound having two or more (meth)acryloyl groups in one molecule, which can increase the glass transition temperature of the cured product and therefore the heat resistance of the cured product and the sealing material 5.

[0049] The acrylic compound (A1) has a refractive index of 1.459 or less, and may contain an appropriate compound that further satisfies one or more of the above-mentioned preferred conditions.

[0050] The acrylic compound (A1) contains at least one compound selected from the group consisting of, for example, di(meth)acrylic acid esters of alkylene glycols, di(meth)acrylic acid esters of polyalkylene glycols, and di(meth)acrylic acid esters of alkylene oxide-modified alkylene glycols. Note that "(meth)acrylic" refers to at least one of "acrylic" and "methacrylic".

[0051] The alkylene glycol in the di(meth)acrylic acid ester of alkylene glycol preferably has 2 to 12 carbon atoms, more preferably 4 to 12. The alkylene glycol may be linear or branched, such as 1,3-butylene glycol and neopentyl glycol. In particular, the di(meth)acrylic acid ester of alkylene glycol preferably contains at least one compound selected from the group consisting of 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, 1,4-butanediol dimethacrylate, 1,3-butylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, and 1,12-dodecanediol dimethacrylate.In addition, examples of alkylene glycol di(meth)acrylate esters include Sartomer product number SR213, Osaka Organic Chemical Industry Co., Ltd. product number V195, Sartomer product number SR212, Sartomer product number SR247, Kyoei Chemical Industry Co., Ltd. product name Light Acrylate NP-A, Sartomer product number SR238NS, Osaka Organic Chemical Industry Co., Ltd. product number V230, Daicel Corporation product number HDDA, Kyoei Chemical Industry Co., Ltd. product number 1,6HX-A, Osaka Organic Chemical Industry Co., Ltd. product number V260, Kyoei Chemical Industry Co., Ltd. product number 1,9-ND-A, Shin-Nakamura Chemical Co., Ltd. product number A-NOD-A, and Sartomer product number CD595, Sartomer product number It is preferable to contain at least one compound selected from the group consisting of product number SR214NS, product number BD from Shin-Nakamura Chemical Co., Ltd., product number SR297 from Sartomer, product number SR248 from Sartomer, product name Light Ester NP from Kyoei Chemical Co., Ltd., product number SR239NS from Sartomer, product name Light Ester 1,6HX from Kyoei Chemical Co., Ltd., product number HD-N from Shin-Nakamura Chemical Co., Ltd., product name Light Ester 1,9ND from Kyoei Chemical Co., Ltd., product number NOD-N from Shin-Nakamura Chemical Co., Ltd., product name Light Ester 1,10DC from Kyoei Chemical Co., Ltd., product number DOD-N from Shin-Nakamura Chemical Co., Ltd., and product number SR262 from Sartomer.

[0052] The alkylene glycol in the di(meth)acrylic acid ester of polyalkylene glycol has, for example, 2 to 4 carbon atoms. The polyalkylene glycol includes, for example, at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. The greater the carbon number of the polyalkylene glycol, the higher the hydrophobicity of the cured product and the sealing material 5, making it more difficult for moisture to permeate the sealing material 5. Therefore, it is particularly preferable that the polyalkylene glycol is propylene glycol. The degree of polymerization of the alkylene glycol is, for example, 2 to 7, preferably 2 to 6, and also preferably 2 to 3. It is particularly preferable that the di(meth)acrylic acid ester of polyalkylene glycol contains at least one compound selected from the group consisting of diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, hexaethylene glycol dimethacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, and tritetramethylene glycol diacrylate. Furthermore, it is preferable that the di(meth)acrylic acid ester of polyalkylene glycol contains at least one compound selected from the group consisting of Sartomer Corporation product number SR230, Sartomer Corporation product number SR508NS, Daicel Corporation product number DPGDA, Sartomer Corporation product number SR306NS, Daicel Corporation product number TPGDA, Osaka Organic Chemical Industry Ltd. product number V310HP, Shin-Nakamura Chemical Co., Ltd. product number APG200, Kyoei Chemical Co., Ltd. product name Light Acrylate PTMGA-250, Sartomer Corporation product number SR231NS, Kyoei Chemical Co., Ltd. product name Light Ester 2EG, Sartomer Corporation product number SR205NS, Kyoei Chemical Co., Ltd. product name Light Ester 3EG, Mitsubishi Chemical Corporation product name Acrylate HX, and Shin-Nakamura Chemical Co., Ltd. product number 3PG.

[0053] Examples of di(meth)acrylic acid esters of alkylene oxide-modified alkylene glycols include propylene oxide-modified neopentyl glycol and di(meth)acrylic acid esters of alkylene oxide-modified alkylene glycols include, for example, EBECRYL145 manufactured by Daicel Corporation.

[0054] The acrylic compound (A) may further contain a polyfunctional acrylic compound (A2) other than the above acrylic compound (A1). The polyfunctional acrylic compound (A2) has two or more (meth)acryloyl groups in one molecule and has a refractive index higher than 1.459. The polyfunctional acrylic compound (A2) can increase the glass transition temperature of the cured product, thereby improving the heat resistance of the cured product and the encapsulant 5. The polyfunctional acrylic compound (A2) contains at least one component selected from the group consisting of di(meth)acrylic acid esters of polyalkylene glycols, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, and triethylene glycol diacrylate, each having a refractive index higher than 1.459. The di(meth)acrylic acid ester of polyalkylene glycol having a refractive index higher than 1.459 can contain, for example, at least one compound selected from the group consisting of tetraethylene glycol diacrylate (polyethylene glycol 200 diacrylate), nonaethylene glycol diacrylate (polyethylene glycol 400 diacrylate), and tetraethylene glycol dimethacrylate (polyethylene glycol 200 dimethacrylate).

[0055] The boiling point of the polyfunctional acrylic compound (A2) is preferably 270°C or higher. In this case, the polyfunctional acrylic compound (A2) is less likely to volatilize from the composition (X) during storage or when the composition (X) is heated. Therefore, the storage stability of the composition (X) is less likely to be impaired. Furthermore, even if unreacted polyfunctional acrylic compound (A2) remains in the cured product and the encapsulant 5, outgassing due to the polyfunctional acrylic compound (A2) is less likely to occur from the cured product and the encapsulant 5. Therefore, voids due to outgassing are less likely to occur within the light-emitting device 1, for example, between the encapsulant 5 and the passivation layer 6. If voids are present in the light-emitting device 1, moisture may reach the light-emitting element 4 through the voids. However, if voids are less likely to occur, moisture is less likely to reach the light-emitting element 4, thereby reducing moisture-induced degradation of the light-emitting element 4. The boiling point of the polyfunctional acrylic compound (A2) is more preferably 280°C or higher. The definition of the boiling point of the polyfunctional acrylic compound (A2) is the same as the definition of the boiling point of the acrylic compound (A1).

[0056] The acrylic compound (A) may contain a compound (A3) having three or more (meth)acryloyl groups in one molecule. The compound (A3) is defined only by the number of (meth)acryloyl groups in one molecule. Therefore, the compounds contained in the acrylic compound (A1) and the polyfunctional acrylic compound (A2) may overlap with the compounds contained in the compound (A3).

[0057] The compound (A3) may contain, for example, at least one selected from the group consisting of trimethylolpropane triacrylate and trimethylolpropane trimethacrylate. When the acrylic compound (A) contains the compound (A3), the compound (A3) can increase the glass transition temperature of the cured product, thereby particularly improving the heat resistance of the cured product and the sealing material 5.

[0058] When the acrylic compound (A) contains the compound (A3), the percentage of the compound (A3) relative to the acrylic compound (A) is preferably greater than 0% by mass and not greater than 25% by mass. The percentage of the compound (A3) is more preferably 10% by mass or greater. In this case, the glass transition temperature of the cured product can be particularly increased. Furthermore, when the compound (A3) is 25% by mass or less, an increase in the viscosity of the composition (X) due to the compound (A3) is unlikely to occur. When the percentage of the compound (A3) is 20% by mass or less, an increase in the viscosity of the composition (X) is particularly unlikely to occur.

[0059] The acrylic compound (A) may contain a monofunctional acrylic compound (A4) having only one (meth)acryloyl group per molecule. The monofunctional acrylic compound (A4) can suppress shrinkage of the composition (X) during curing. Furthermore, the monofunctional acrylic compound (A4) can contribute to reducing the viscosity of the composition (X). However, since the monofunctional acrylic compound (A4) tends to increase the refractive index of the composition (X), in order to lower the refractive index of the composition (X), it is preferable that the acrylic compound (A) does not contain the monofunctional acrylic compound (A4), or that the amount of the monofunctional acrylic compound (A4) in the acrylic compound (A) is such that the refractive index of the composition (X) is not excessively increased. When the acrylic compound (A) contains the monofunctional acrylic compound (A4), the amount of the monofunctional acrylic compound (A4) relative to the total amount of the acrylic compound (A) is preferably greater than 0% by mass and less than 30% by mass. When the amount of the monofunctional acrylic compound (A4) is greater than 0% by mass, shrinkage of the composition (X) during curing can be suppressed. Furthermore, if the amount of the monofunctional acrylic compound (A4) is 30% by mass or less, the refractive index of the composition (X) is less likely to increase due to the monofunctional acrylic compound (A4).

[0060] Examples of the monofunctional acrylic compound (A4) include tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, 2-methoxyethyl acrylate, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, 3-methoxybutyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, and methoxydixyl acrylate. Tyl acrylate, ethyl diglycol acrylate, cyclic trimethylolpropane formal monoacrylate, imide acrylate, isoamyl acrylate, ethoxylated succinic acid acrylate, trifluoroethyl acrylate, ω-carboxypolycaprolactone monoacrylate, cyclohexyl acrylate, 2-(2-ethoxyethoxy)ethyl acrylate, stearyl acrylate, diethylene glycol monobutyl ether acrylate, lauryl acrylate, isodecyl acrylate, 3,3,5-trimethylcyclohexanol Acrylate, isooctyl acrylate, octyl / decyl acrylate, tridecyl acrylate, caprolactone acrylate, ethoxylated (4)nylphenol acrylate, methoxypolyethylene glycol (350) monoacrylate, methoxypolyethylene glycol (550) monoacrylate, phenoxyethyl acrylate, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl acrylate, methylphenoxyethyl acrylate, 4-t- Butylcyclohexyl acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, tribromophenyl acrylate, ethoxylated tribromophenyl acrylate, 2-phenoxyethyl acrylate, ethylene oxide adduct of 2-phenoxyethyl acrylate, propylene oxide adduct of 2-phenoxyethyl acrylate, acryloylmorpholine, isobornyl acrylate, dicyclopentanyl acrylate, phenoxydiethylene glycol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 1,It contains at least one compound selected from the group consisting of 4-cyclohexanedimethanol monoacrylate, 3-methacryloyloxymethyl cyclohexene oxide, and 3-acryloyloxymethyl cyclohexene oxide.

[0061] It is also preferable that the acrylic compound (A1) contains a compound (A5) having silicon in its molecular skeleton. In this case, the adhesion between the cured product and the sealant 5 and the inorganic material member is improved. Therefore, gaps are less likely to form between the sealant 5 and the passivation layer 6, and moisture is less likely to penetrate into the light-emitting element 4 through these gaps.

[0062] The compound (A5) is defined only by the type of atoms in the molecular skeleton, and therefore, the compounds included in each of the acrylic compound (A1), the polyfunctional acrylic compound (A2), the acrylic compound (A3), and the monofunctional acrylic compound (A4) may overlap with the compounds included in the compound (A5).

[0063] The compound having silicon in its molecular skeleton contains at least one compound selected from the group consisting of, for example, 3-(trimethoxysilyl)propyl acrylate (e.g., product number KBM5103 manufactured by Shin-Etsu Chemical Co., Ltd.) and a (meth)acrylic group-containing alkoxysilane oligomer (e.g., product number KR-513 manufactured by Shin-Etsu Chemical Co., Ltd.). The boiling point of the compound having silicon in its molecular skeleton is preferably 270°C or higher. It is also preferable that the compound having silicon in its molecular skeleton is a polyfunctional compound. For this reason, it is particularly preferable that the compound having silicon in its molecular skeleton contains a (meth)acrylic group-containing alkoxysilane oligomer.

[0064] When the acrylic compound (A) contains a compound having silicon in its molecular skeleton, the percentage of the compound having silicon in its molecular skeleton relative to the acrylic compound (A) is preferably 0.1% by mass or more, more preferably 1% by mass or less, and also preferably 20% by mass or less.

[0065] The composition (X) may further contain a radically polymerizable compound (E) other than the acrylic compound (A). The radically polymerizable compound (E) may contain either or both of a polyfunctional radically polymerizable compound (E1) having two or more radically polymerizable functional groups per molecule and a monofunctional radically polymerizable compound (E2) having only one radically polymerizable functional group per molecule. The amount of the radically polymerizable compound (E) relative to the total amount of the acrylic compound (A) and the radically polymerizable compound (E) is, for example, 10% by mass or less. The polyfunctional radically polymerizable compound (E1) may contain, for example, at least one compound selected from the group consisting of aromatic urethane oligomers, aliphatic urethane oligomers, epoxy acrylate oligomers, polyester acrylate oligomers, and other special oligomers, each having two or more ethylenic double bonds per molecule. The monofunctional radically polymerizable compound (E2) contains, for example, at least one compound selected from the group consisting of N-vinylformamide, vinylcaprolactam, vinylpyrrolidone, phenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, 1,2-butylene oxide, 1,3-butadiene monoxide, 1,2-epoxydodecane, epichlorohydrin, 1,2-epoxydecane, styrene oxide, cyclohexene oxide, 3-vinylcyclohexene oxide, 4-vinylcyclohexene oxide, N-vinylpyrrolidone, and N-vinylcaprolactam.

[0066] The photopolymerization initiator (B) is not particularly limited as long as it is a compound that generates radical species when irradiated with ultraviolet light. The photopolymerization initiator (B) contains at least one compound selected from the group consisting of aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (such as thioxanthone compounds and thiophenyl group-containing compounds), hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds. The amount of photopolymerization initiator (B) per 100 parts by mass of composition (X) is, for example, 1 part by weight or more and 10 parts by mass or less.

[0067] The photopolymerization initiator (B) may contain a sensitizer as a part of the photopolymerization initiator (B). The sensitizer can accelerate the radical generation reaction of the photopolymerization initiator (B) to improve the reactivity of the radical polymerization and increase the crosslink density. The sensitizer can contain, for example, at least one compound selected from the group consisting of 9,10-dibutoxyanthracene, 9-hydroxymethylanthracene, thioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, anthraquinone, 1,2-dihydroxyanthraquinone, 2-ethylanthraquinone, 1,4-diethoxynaphthalene, p-dimethylaminoacetophenone, p-diethylaminoacetophenone, p-dimethylaminobenzophenone, p-diethylaminobenzophenone, 4,4′-bis(dimethylamino)benzophenone, 4,4′-bis(diethylamino)benzophenone, p-dimethylaminobenzaldehyde, and p-diethylaminobenzaldehyde.

[0068] The content of the sensitizer in composition (X) is, for example, 0.1 to 5 parts by mass, and preferably 0.1 to 3 parts by mass, per 100 parts by mass of the solid content of composition (X). When the content of the sensitizer is within this range, composition (X) can be cured in air, eliminating the need to cure composition (X) in an inert atmosphere such as a nitrogen atmosphere.

[0069] The composition (X) may contain a polymerization accelerator in addition to the photopolymerization initiator (B). The polymerization accelerator includes, for example, an amine compound such as ethyl p-dimethylaminobenzoate, 2-ethylhexyl p-dimethylaminobenzoate, methyl p-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, or butoxyethyl p-dimethylaminobenzoate.

[0070] The composition (X) preferably further contains a hollow filler (C), which can reduce the refractive index of the composition (X).

[0071] The hollow filler (C) preferably has an average particle size of 150 nm or less. In this case, the hollow filler (C) is less likely to reduce the transparency of the cured product and the encapsulant 5. The hollow filler (C) preferably has an average particle size of 10 nm or more and 100 nm or less, and more preferably has an average particle size of 20 nm or more and 80 nm or less. The average particle size of the hollow filler (C) is the median diameter calculated from the results of measurement using dynamic light scattering. The Nanotrac Wave series from Microtrac Bell Corporation can be used as a measurement device.

[0072] The hollow filler (C) preferably has a void ratio of 30% to 70%, in which case the hollow filler (C) can effectively reduce the refractive index of the cured product and the optical component.

[0073] The refractive index of the hollow filler (C) is preferably 1.40 or less. In this case, the hollow filler (C) can effectively reduce the refractive index of the cured product and the sealing material 5. The refractive index of the hollow filler (C) is more preferably 1.25 or more and 1.40 or less, even more preferably 1.25 or more and 1.35 or less, and particularly preferably 1.25 or more and 1.30 or less.

[0074] The hollow filler (C) preferably contains at least one of silica particles (hereinafter referred to as hollow silica particles) and resin particles (hereinafter referred to as hollow resin particles). In this case, the hollow filler (C) is particularly unlikely to impair the light transmittance of the cured product and optical components.

[0075] The hollow filler (C) preferably contains hollow resin particles. Hollow resin particles are less likely to break when force is applied compared to hollow silica particles. Therefore, even if force is applied to the hollow resin particles during processes such as kneading when preparing the composition (X) containing the hollow resin particles and during the process of producing the encapsulant 5 from the composition (X), the hollow resin particles are less likely to break. Therefore, the refractive index of the encapsulant 5 is likely to be maintained low. The hollow resin particles are made of, for example, an acrylic resin, i.e., hollow acrylic particles.

[0076] The hollow silica particles may contain, for example, Cataloid-Si manufactured by JGC Catalysts and Chemicals Co., Ltd. The hollow acrylic particles may contain, for example, Techpolymer NH series manufactured by Sekisui Plastics Co., Ltd.

[0077] When composition (X) contains hollow filler (C), the percentage of hollow filler (C) relative to composition (X) is preferably greater than 0% by volume and not more than 7% by volume. When the percentage of hollow filler (C) is not more than 7% by volume, the hollow filler (C) is less likely to increase the viscosity of composition (X).

[0078] The composition (X) may further contain a moisture absorbent (D). When the composition (X) contains the moisture absorbent (D), the cured product of the composition (X) and the optical component can have moisture absorption properties. Therefore, the encapsulant 5, which is an optical component, can further prevent moisture from penetrating into the light-emitting element 4 in the light-emitting device 1. The average particle size of the moisture absorbent (D) is preferably 200 nm or less. In this case, the cured product can have high transparency.

[0079] The moisture absorbent (D) is preferably inorganic particles having moisture absorption properties, and preferably contains at least one component selected from the group consisting of zeolite particles, silica gel particles, calcium chloride particles, and titanium oxide nanotube particles. It is particularly preferred that the moisture absorbent (D) contains zeolite particles.

[0080] Zeolite particles with an average particle size of 200 nm or less can be produced, for example, by pulverizing common industrial zeolite. To produce the zeolite particles, the zeolite may be pulverized and then crystallized by hydrothermal synthesis or the like. In this case, the zeolite particles can have particularly high hygroscopicity. Examples of methods for producing such zeolite particles are disclosed in JP 2016-69266 A, JP 2013-049602 A, and the like.

[0081] When composition (X) contains a moisture absorbent (D), the proportion of moisture absorbent (D) relative to the total amount of composition (X) is preferably 1% by mass or more and 20% by mass or less. If the proportion of moisture absorbent (D) is 1% by mass or more, the cured product can have particularly high moisture absorption. Furthermore, if the proportion of moisture absorbent (D) is 20% by mass or less, the viscosity of composition (X) can be particularly reduced, and composition (X) can have a sufficiently low viscosity that it can be applied by an inkjet method. The proportion of moisture absorbent (D) is more preferably 3% by mass or more, and particularly preferably 5% by mass or more. Furthermore, the proportion of moisture absorbent (D) is more preferably 15% by mass or less, and particularly preferably 13% by mass or less.

[0082] When the composition (X) contains a hollow filler (C), the composition (X) preferably further contains a dispersant (E). In this case, the dispersant (E) can improve the dispersibility of the hollow filler (C) in the composition (X). Therefore, the composition (X) is less likely to experience an increase in viscosity and a decrease in storage stability due to the hollow filler (C).

[0083] Even when the composition (X) contains the moisture absorbent (D), it is preferable that the composition (X) further contains a dispersant (E). In this case, the dispersant (E) can improve the dispersibility of the moisture absorbent (D) in the composition (X). Therefore, the composition (X) is less likely to experience an increase in viscosity and a decrease in storage stability due to the moisture absorbent (D).

[0084] The dispersant (E) is a surfactant capable of adsorbing to particles. The dispersant (E) has an adsorption group (commonly referred to as an anchor) capable of adsorbing to particles and a molecular skeleton (commonly referred to as a tail) that attaches to the particles when the adsorption group adsorbs to the particles. The dispersant (E) contains at least one component selected from the group consisting of, for example, an acrylic dispersant in which the tail is an acrylic molecular chain, a urethane dispersant in which the tail is a urethane molecular chain, and a polyester dispersant in which the tail is a polyester molecular chain. The adsorption group includes, for example, at least one of a basic polar functional group and an acidic polar functional group. The basic polar functional group includes, for example, at least one group selected from the group consisting of an amino group, an imino group, an amide group, an imide group, and a nitrogen-containing heterocyclic group. The acidic polar functional group includes, for example, at least one group selected from the group consisting of a carboxyl group and a phosphate group. The dispersant (E) may contain at least one compound selected from the group consisting of, for example, the Solsperse series manufactured by Nippon Louvre Resol Co., Ltd., the DISPERBYK series manufactured by BYK Japan Co., Ltd., and the Ajisper series manufactured by Ajinomoto Fine-Techno Co., Ltd.

[0085] When composition (X) contains hollow filler (C), the amount of dispersant (E) relative to hollow filler (C) is preferably 5 parts by mass or more and 60 parts by mass or less. When composition (X) contains moisture absorbent (D), the amount of dispersant (E) relative to moisture absorbent (D) is preferably 5 parts by mass or more and 60 parts by mass or less. When composition (X) contains hollow filler (C) and moisture absorbent (D), the amount of dispersant (E) relative to the total of hollow filler (C) and moisture absorbent (D) is preferably 5 parts by mass or more and 60 parts by mass or less. In either case, when the amount of dispersant (E) is 5 parts by mass or more, the function of dispersant (E) can be effectively exhibited, and when the amount is 60 parts by mass or less, free molecules of dispersant (E) in sealant 5 can be prevented from impairing adhesion between sealant 5 and inorganic material components. In either case, the amount of dispersant (D) is more preferably 15 parts by mass or more, more preferably 50 parts by mass or less, even more preferably 40 parts by mass or less, and particularly preferably 30 parts by mass or less.

[0086] It is preferable that the composition (X) does not contain a solvent. In this case, when preparing a cured product from the composition (X), it is not necessary to dry the composition (X) to volatilize the solvent. In addition, the storage stability of the composition (X) is further improved.

[0087] Composition (X) can be prepared by mixing the above-mentioned components. Composition (X) is preferably liquid at 25°C.

[0088] 3. Method for producing encapsulant and method for producing organic EL light-emitting device A method for producing the encapsulant 5 using the composition (X) and a method for producing the light emitting device 1 will be described.

[0089] In this embodiment, it is preferable to mold the composition (X) by an inkjet method and then irradiate the composition (X) with ultraviolet light to cure it, thereby producing the encapsulant 5. In this embodiment, the composition (X) can be applied and molded by an inkjet method.

[0090] When applying composition (X) by the inkjet method, if composition (X) has a sufficiently low viscosity at room temperature, for example, if the viscosity at 25°C is 30 mPa s or less, particularly 15 mPa s or less, composition (X) can be molded by applying it by the inkjet method without heating.

[0091] If composition (X) has the property of decreasing viscosity when heated, composition (X) may be heated and then applied by inkjet printing to form a mold. If composition (X) has a viscosity of 30 mPa·s or less, particularly 15 mPa·s or less at 40°C, composition (X) can be made to have a low viscosity by simply heating it slightly, and this low-viscosity composition (X) can be ejected by inkjet printing. The heating temperature for composition (X) is, for example, 20°C or higher and 50°C or lower.

[0092] More specifically, for example, first, a support substrate 2 is prepared. On one surface of this support substrate 2, partition walls 7 are fabricated by photolithography using, for example, a photosensitive resin material. Next, a plurality of light-emitting elements 4 are provided on one surface of the support substrate 2. The light-emitting elements 4 can be fabricated by an appropriate method such as a vapor deposition method or a coating method. In particular, it is preferable to fabricate the light-emitting elements 4 by a coating method such as an inkjet method. In this way, an element array 9 is fabricated on the support substrate 2.

[0093] Next, a first passivation layer 61 is provided on the element array 9. The first passivation layer 61 can be formed by a vapor deposition method such as a plasma CVD method.

[0094] Next, the composition (X) is applied to the first passivation layer 61 by, for example, an inkjet method to form a coating film. If the inkjet method is used for both the formation of the light-emitting element 4 and the application of the composition (X), the manufacturing efficiency of the light-emitting device 1 can be particularly improved. Next, the coating film is cured by irradiating it with ultraviolet light to form the encapsulant 5. The thickness of the encapsulant 5 is, for example, 5 μm or more and 50 μm or less.

[0095] Next, a second passivation layer 62 is provided on the sealing material 5. The second passivation layer 62 can be formed by a vapor deposition method such as a plasma CVD method.

[0096] Next, an ultraviolet-curable resin material is provided on one surface of the support substrate 2 so as to cover the second passivation layer 62, and then the transparent substrate 3 is placed on top of this resin material. The transparent substrate 3 is, for example, a glass substrate or a transparent resin substrate.

[0097] Next, ultraviolet light is irradiated from the outside toward the transparent substrate 3. The ultraviolet light passes through the transparent substrate 3 and reaches the ultraviolet-curable resin material, which then hardens, forming the second sealing member 52.

[0098] In this embodiment, as described above, it is possible to make it difficult for the light emitting efficiency to decrease due to the passivation layer 6 and the sealing material 5 in the light emitting device 1 to decrease.

[0099] The thickness of the sealing material 5 is, for example, 1 μm or more and 20 μm or less. The thickness of the sealing material 5 may be 15 μm or less. In this case, by thinning the sealing material 5, the light emitting device 1 can be thinned, and a flexible light emitting device 1 can be obtained. Furthermore, even if the thickness of the sealing material 5 is 10 μm or less, in this embodiment, a decrease in luminous efficiency caused by the passivation layer 6 and the sealing material 5 in the light emitting device 1 can be made less likely to occur. It is more preferable that the thickness of the sealing material 5 is 8 μm or less. Furthermore, in order for the sealing material 5 to effectively suppress moisture from entering the light emitting element 4, the thickness of the sealing material 5 is preferably 3 μm or more, and more preferably 5 μm or more.

[0100] The thickness of the passivation layer 6 overlapping the sealing material 5 is, for example, not less than 0.1 μm and not more than 2 μm. When the passivation layer 6 includes the first passivation layer 61 and the second passivation layer 62 as described above, it is preferable that the thickness of each of the first passivation layer 61 and the second passivation layer 62 is not less than 0.1 μm and not more than 2 μm.

[0101] The refractive index of the sealing material 5 is preferably 70% or more and 80% or less of the refractive index of the passivation layer 6. For example, if the passivation layer 6 is made of silicon nitride with a refractive index of 1.87, the refractive index of the sealing material 5 is preferably 1.32 or more and 1.50 or less. In this case, a decrease in the luminous efficiency of the light-emitting device 1 due to the passivation layer 6 and the sealing material 5 can be particularly prevented.

[0102] In this specification, the refractive index of each of the sealing material 5 and the passivation layer 6 is the refractive index at 25°C for light with a wavelength of 587.6 nm (helium d-line).

[0103] The use of the composition (X) according to this embodiment is not limited to the production of the encapsulant 5 for the light-emitting element 4. The composition (X) can be used to produce various optical components that transmit light emitted by a light source. For example, the optical component may be a color resist. That is, for example, a phosphor may be contained in the composition (X), and a color resist for a color filter may be produced from this composition (X). This color filter can be provided in a display device such as an organic EL display or a micro LED display, which is a light-emitting device. [Example]

[0104] 1. Preparation of the Composition Compositions of the examples and comparative examples were prepared by mixing the components shown in the table below.

[0105] The details of the components shown in the table are as follows. The viscosity of each component was measured using a rheometer (Anton Paar Japan, model number DHR-2) at a temperature of 25°C and a shear rate of 1000 s -1 The values ​​were measured under the following conditions.

[0106] (1) Acrylic compounds KBM5103: 3-(trimethoxysilyl)propyl acrylate, a monofunctional acrylic compound containing silicon atoms, product number KBM5103 manufactured by Shin-Etsu Chemical Co., Ltd., viscosity 4 mPa·s, refractive index 1.427, boiling point 260°C. · KR513: Acrylic group-containing alkoxysilane oligomer, an acrylic compound with an average of three or more functional groups containing silicon atoms, viscosity 50 mPa·s, refractive index 1.427, boiling point 300°C or higher. 3PG: Tris(propylene glycol) dimethacrylate, a bifunctional acrylic compound, manufactured by Shin-Nakamura Chemical Co., Ltd., product number 3PG, viscosity 13 mPa·s, glass transition temperature -8°C, refractive index 1.450, boiling point 400°C. APG200: Tris(propylene glycol) diacrylate, a bifunctional acrylic compound, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity 12 mPa·s, glass transition temperature 55-62°C, refractive index 1.449, boiling point 295°C. SR297: 1,3-butylene glycol dimethacrylate, a bifunctional acrylic compound, manufactured by Sartomer Corporation, product number SR297, viscosity 7 mPa·s, glass transition temperature 85°C, refractive index 1.449, boiling point 290°C. EBECRYL145: Propylene oxide-modified neopentyl glycol diacrylate, a bifunctional acrylic compound, manufactured by Daicel Allnex Corporation, product number EBECRYL145, viscosity 20 mPa·s, glass transition temperature 60°C, refractive index 1.459, boiling point 408°C. ·BD: 1,4-butanediol dimethacrylate, a bifunctional acrylic compound, manufactured by Shin-Nakamura Chemical Co., Ltd., viscosity 7 mPa·s, glass transition temperature 55°C, refractive index 1.456, boiling point 280°C. TMPTA: Trimethylolpropane triacrylate, a trifunctional acrylic compound with a viscosity of 106 mPa·s, a glass transition temperature of 62°C, a refractive index of 1.472, and a boiling point of 300°C or higher. . · TMPTMA: Trimethylolpropane trimethacrylate, a trifunctional acrylic compound, with a viscosity of 44 mPa·s, a glass transition temperature of 27°C, a refractive index of 1.470, and a boiling point of 300°C or higher. Pentaerythritol tetraacrylate: Viscosity 342 mPa·s, glass transition temperature 103°C, refractive index 1.485, boiling point above 300°C. Polyethylene glycol 200 dimethacrylate: Viscosity 15 mPa·s, glass transition temperature -9°C, refractive index 1.460, boiling point 350°C.

[0107] (2) Photopolymerization initiator Irgacure 184: 1-Hydroxy-cyclohexyl-phenyl-ketone, manufactured by BASF, trade name Irgacure 184. Irgacure TPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, manufactured by BASF, product name Irgacure TPO.

[0108] (3) Hollow filler Hollow acrylic particles: manufactured by Sekisui Chemical Co., Ltd., average particle size 80nm, hollowness 40%, refractive index 1.30, specific gravity 0.75. Hollow silica particles: manufactured by JGC Catalysts and Chemicals, average particle size 50nm, hollowness 33%, refractive index 1.30, specific gravity 1.32. Hollow silica particles 2: manufactured by JGC Catalysts and Chemicals, average particle size 60 nm, hollowness 44%, refractive index 1.25, specific gravity 1.12.

[0109] (4) Dispersant SOLSPERSE32000: A waxy comb-type dispersant with amino and phosphate groups as adsorption groups, amine value 31 mg KOH / g, acid value 15 mg KOH / g, viscosity 14,000 mP·s, weight-average molecular weight 3,900, manufactured by Lubrizol Corporation, product number SOLSPERSE32000.

[0110] 2.Evaluation Test The following evaluation tests were carried out on the examples and comparative examples, and the results are shown in the table below.

[0111] (1) Transmittance The composition was applied to form a coating film, which was then irradiated with a UV light of approximately 30 mW / cm using an LED-UV irradiator (peak wavelength 365 nm) manufactured by Panasonic Electric Works Co., Ltd. 2 Purple for 50 seconds under the condition A 10 μm thick film was prepared by photocuring with ultraviolet light. The transmittance of this film at a wavelength of 587.6 nm was measured using an ellipsometer (Filmtek3000 manufactured by SCI Corporation).

[0112] (2) Volatility The composition was allowed to stand in an argon atmosphere at 20°C (dew point temperature -70°C) for 24 hours. The resulting weight loss of the composition was measured. Weight loss of 0.5% or less was rated "A," 0.5-1% was rated "B," and 1% or more was rated "C."

[0113] (3) Viscosity The viscosity of the composition was measured using a rheometer (Anton Paar Japan, model number DHR-2) at a temperature of 25°C and a shear rate of 1000 s -1 The measurement was carried out under the following conditions.

[0114] (4) Inkjet compatibility The composition was placed in the cartridge of an inkjet printer (Ricoh MH2420). After confirming that the composition in the cartridge could be ejected from the nozzle of the inkjet printer, the composition was ejected from the nozzle and test patterns were continuously printed. As a result, if the composition could be ejected for one hour and the ejection operation was stable, it was evaluated as "A," if the composition could be ejected for one hour but the ejection operation became intermittently unstable, it was evaluated as "B," and if the nozzle became clogged before one hour had passed since the start of ejection and the composition could no longer be ejected, it was evaluated as "C."

[0115] (5) Refractive index The refractive index of the composition at a wavelength of 589.3 nm was measured using a refractometer (model RA-620) manufactured by Kyoto Electronics Co., Ltd.

[0116] (6) Refractive index of the cured product The refractive index of light with a wavelength of 587.6 nm of the film prepared in the above "(1) Transmittance" was measured using an ellipsometer (Filmtek3000 manufactured by SCI Corporation).

[0117] (7) Glass transition temperature The composition was applied to form a coating film, which was then irradiated with a UV light of approximately 30 mW / cm using an LED-UV irradiator (peak wavelength 365 nm) manufactured by Panasonic Electric Works Co., Ltd. 2 Purple for 50 seconds under the condition A film with a thickness of 200 μm was prepared by photocuring with ultraviolet light irradiation. The glass transition temperature of a sample cut from this film was measured using a viscoelasticity measuring device (manufactured by Hitachi High-Tech Science Corporation, model number DMA7100).

[0118] (8) Adhesion The composition was applied to the surface of a quartz glass piece (76 mm × 52 mm × 1 mm) to form a coating film with a thickness of 50 μm, and another quartz glass piece (76 mm × 52 mm × 1 mm) was placed on top of this coating film. Subsequently, the coating film was irradiated with approximately 30 mW / cm using an LED-UV irradiator (peak wavelength 365 nm) manufactured by Panasonic Electric Works Co., Ltd. 2 Irradiate with UV light for 50 seconds under the conditions The mixture was cured by heating, and test pieces were obtained.

[0119] The test pieces were placed in a constant temperature and humidity chamber at 85°C and 85% RH for 24 hours, and then the adhesion strength between the two quartz glass pieces was evaluated by a T-peel test based on JIS K 6854. As a result, an adhesion strength of 3 MPa or more was evaluated as "A," an adhesion strength of less than 3 MPa was evaluated as "B," and a case where the quartz glass pieces peeled off and the adhesion strength could not be measured was evaluated as "C."

[0120] (9) Evaluation of light extraction efficiency Two substrates were obtained by forming a 1 μm thick silicon nitride film on each surface of two quartz glass pieces (dimensions 76 mm × 52 mm × 1 mm) by plasma CVD. A composition was applied to the surface of the silicon nitride film of one substrate to form a 5 μm thick coating film, and the silicon nitride film of the other substrate was then placed on top of this coating film. Subsequently, the coating film was irradiated with approximately 30 mW / cm using an LED-UV irradiator (peak wavelength 365 nm) manufactured by Panasonic Electric Works Co., Ltd. 2 50 seconds under the condition The adhesive was cured by irradiating it with ultraviolet light for 10 minutes, thereby obtaining a test piece.

[0121] The visible light transmittance of this test piece was measured, and if the visible light transmittance was higher than that of Comparative Example 1, it was evaluated as "A", and if not, it was evaluated as "B".

[0122] [Table 1]

[0123] [Table 2]

Claims

1. Contains an acrylic compound (A), a photopolymerization initiator (B), and a hollow filler (C), the acrylic compound (A) contains an acrylic compound (A1) having a refractive index of 1.450 or less, and the percentage of the acrylic compound (A1) relative to the acrylic compound (A) is 55 mass% or more; The hollow filler (C) contains hollow resin particles. An ultraviolet-curable resin composition for producing an optical component that transmits light emitted by a light source.

2. having a refractive index of 1.459 or less; The ultraviolet-curable resin composition according to claim 1 .

3. The acrylic compound (A1) contains a compound having two or more (meth)acryloyl groups in one molecule. The ultraviolet-curable resin composition according to claim 1 or 2.

4. The viscosity of the acrylic compound (A1) at 25°C is 25 mPa s or less. The ultraviolet-curable resin composition according to claim 1 .

5. Formed using the inkjet method, The ultraviolet-curable resin composition according to claim 1 .

6. The glass transition temperature of the cured product is 80°C or higher. The ultraviolet-curable resin composition according to claim 1 .

7. A method for manufacturing a light emitting device comprising a light source, an optical component and an inorganic layer that transmit light emitted by the light source, the optical component and the inorganic layer overlapping each other, The method includes forming the ultraviolet-curable resin composition according to claim 1 by an inkjet method, and then curing the ultraviolet-curable resin composition by irradiating it with ultraviolet light to produce the optical component. A method for manufacturing a light-emitting device.

8. The ultraviolet-curable resin composition is heated and then molded by an inkjet method. The method for manufacturing the light emitting device according to claim 7 .

9. A light source, an optical component and an inorganic layer that transmit light emitted by the light source, the optical component and the inorganic layer overlapping each other, and the optical component being a cured product of the ultraviolet-curable resin composition according to any one of claims 1 to 6. Light-emitting device.

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