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

Abstract

To provide an ultraviolet curable resin composition which is usable for manufacturing an optical component permeating light emitted by a light source therethrough, and hardly lowers light-emitting efficiency caused by an inorganic layer and an optical component in a light-emitting device.SOLUTION: An ultraviolet curable resin composition contains an acrylic compound (A) and a photopolymerization initiator (B). The refractive index of the ultraviolet curable resin composition is 1.457 or less. The acrylic compound (A) contains an acrylic compound (A1) having a refractive index of 1.450 or less, and a compound (A3) having three or more (meth)acryloyl groups in one molecule, and a percentage ratio of the acrylic compound (A1) to the acrylic compound (A) is 55 mass% or more. The acrylic compound (A1) contains a compound having two or more (meth)acryloyl groups in one molecule. The ultraviolet curable resin composition is used for manufacturing an optical component permeating light emitted from the light source therethrough.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an ultraviolet-curable resin composition, a method for producing a light-emitting device, and a light-emitting device. More specifically, the present invention relates to an ultraviolet-curable resin composition for producing an optical component that transmits light emitted from a light source, a method for producing a light-emitting device using the ultraviolet-curable resin composition, and a light-emitting device including the optical component.

Background Art

[0002] Light-emitting devices such as organic EL light-emitting devices are applied to lighting, displays and the like, and are expected to become more widespread in the future.

[0003] Among organic EL light-emitting devices, what is called a top emission type is configured, for example, by arranging an organic EL element on a support substrate and arranging a transparent substrate so as to face the support substrate. In this case, light emitted from the organic EL element passes through the transparent substrate and exits to the outside.

[0004] When an organic EL element is degraded by moisture, non-light-emitting regions called dark spots may be formed. Therefore, covering an organic EL element with a transparent sealing material and a passivation layer made of a nitrogen compound has been practiced to suppress intrusion of moisture from the outside into the organic EL element (see Patent Document 1).

Prior Art Literature

Patent Literature

[0005]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0006] Organic EL light-emitting devices are required not only to suppress dark spots but also to have high luminous efficiency. The inventors have found that providing a encapsulating material 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 pronounced when the thickness of the encapsulating material is thin.

[0007] The object of the present invention is to provide an ultraviolet-curable resin composition that can be used to manufacture optical components that transmit light emitted from a light source and that can prevent a decrease in luminous efficiency caused by the inorganic layer and optical components in a light-emitting device, a method for manufacturing a light-emitting device using this ultraviolet-curable resin composition, and a light-emitting device equipped with optical components made of a cured product of this ultraviolet-curable resin composition. [Means for solving the problem]

[0008] An ultraviolet-curable resin composition for producing an optical component that transmits light emitted from a light source, according to one aspect of the present invention, contains an acrylic compound (A) and a photopolymerization initiator (B), wherein the acrylic compound (A) contains an acrylic compound (A1) with a refractive index of 1.459 or less, and the percentage ratio of the acrylic compound (A1) to the acrylic compound (A) is 50% by 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 comprising a light source, an optical component that transmits light emitted by the light source, and an inorganic layer, wherein the optical component and the inorganic layer overlap, and the method includes molding the ultraviolet-curable resin composition by an inkjet method, and then curing the ultraviolet-curable resin composition by irradiating it with ultraviolet light to produce the optical component.

[0010] A light-emitting device according to one aspect of the present invention comprises a light source, an optical component that transmits light emitted by the light source, and an inorganic layer, wherein the optical component and the inorganic layer overlap, 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 using an ultraviolet-curable resin composition to manufacture optical components of a light-emitting device makes it less likely for a decrease in luminescence efficiency to occur due to the inorganic layer and optical components in the light-emitting device. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic cross-sectional view showing a light-emitting device in one embodiment of the present invention. [Modes for carrying out the invention]

[0013] The following describes one embodiment of the present invention.

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

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

[0016] In the present embodiment, optical components such as the sealing material 5 for the 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 from the light source, and an inorganic layer, and the optical component and the inorganic layer overlap each other. In particular, it is preferable that the sealing material 5 in the light-emitting device 1 that includes the light-emitting element 4, the sealing material 5 covering the light-emitting element 4, and the passivation layer 6, wherein the sealing material 5 and the passivation layer 6 overlap each other, is produced from the composition (X). In this case, the sealing material 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 caused by the passivation layer 6 and the sealing material 5 in the light-emitting device 1 can be made less likely to occur. This is considered to be because, since the composition (X) contains the acrylic compound (A1), the sealing material 5 formed of a cured product of the composition (X) can have a moderately low refractive index compared to the passivation layer 6 made of an inorganic material. That is, it is considered that light interference occurring in the passivation layer 6 and the sealing material 5 caused by the refractive index difference between the sealing material 5 and the passivation layer 6 increases the extraction efficiency of light emitted from the light-emitting element 4 to the outside.

[0017] In the present 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 (sodium D line).

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

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

[0020] It is also preferable that the refractive index of composition (X) is 1.400 or higher. The refractive index of composition (X) is more preferably 1.410 or more and 1.480 or less, and still more preferably 1.420 or more and 1.460 or less.

[0021] In addition, it is preferable that the refractive index of a cured product of composition (X) is 1.510 or less. In this case, reflection of light is particularly unlikely to occur in the inorganic layer and the optical component. It is also preferable that the refractive index of the cured product is 1.420 or higher. The refractive index of the cured product is more preferably 1.430 or more and 1.505 or less, and still more preferably 1.440 or more and 1.499 or less.

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

[0023] It is preferable that the glass transition temperature of a cured product of composition (X) is 80°C or higher. That is, composition (X) preferably has the property of forming a cured product with a glass transition temperature of 80°C or higher upon curing. In this case, the cured product can have favorable heat resistance. Therefore, for example, when a treatment involving temperature rise is applied to the cured product, the cured product is less prone to degradation. For this reason, for example, when an inorganic layer is formed by a vapor deposition method such as plasma CVD on an optical component produced from composition (X), the optical component is less prone to degradation even when heated. The glass transition temperature of the cured product is more preferably 90°C or higher, and still more preferably 100°C or higher. The glass transition temperature of this cured product can be achieved by the composition of composition (X) described in detail below.

[0024] It is preferable that the viscosity of composition (X) at 25°C is 1 mPa·s or more and 30 mPa·s or less. In this case, it is easy to mold composition (X) at room temperature by a method such as a casting method, and molding composition (X) by an inkjet method is also possible. This viscosity is more preferably 25 mPa·s or less, still 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 reduce the viscosity by slightly heating composition (X). Therefore, heating makes it easy to mold composition (X) by methods such as casting, and it is also possible to mold composition (X) by inkjet. Furthermore, since the viscosity can be reduced without significantly heating composition (X), it is possible to reduce the likelihood of changes in the composition of composition (X) due to the volatilization of components in composition (X). It is more preferable if the viscosity is 25 mPa·s or less, even more preferable if it is 20 mPa·s or less, and particularly preferable if it is 15 mPa·s or less. It is also preferable if the 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 these conditions. As a rheometer, for example, model DHR-2 manufactured by Anton Paar Japan can be used.

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

[0028] When the thickness of the cured product of composition (X) is 10 μm, the total light transmittance is preferably 90% or more. In this case, when the cured product is applied to the sealing material 5 in the light-emitting device 1, the efficiency of extracting light that passes through the sealing material 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] The embodiment will be described in more detail below.

[0030] 1. Structure of the light-emitting device First, let's describe the structure of the light-emitting device 1. The light-emitting device 1 comprises a light source and an optical component that transmits the light emitted by the light source. For example, the light-emitting device 1 comprises a light-emitting element 4, a sealing material 5 covering the light-emitting element 4, and a passivation layer 6. In this case, the light-emitting element 4 is the light source, the sealing material 5 is the optical component, and the passivation layer 6 is the inorganic layer. The sealing material 5 and the passivation layer 6 overlap.

[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. If the light-emitting element 4 includes an organic light-emitting diode, the light-emitting device 1 equipped with the light-emitting element 4 is, for example, an organic EL display. If the light-emitting element 4 includes a micro light-emitting diode, the light-emitting device 1 equipped with the light-emitting element 4 is, for example, a micro LED display. EL stands for electroluminescence.

[0032] An example of the structure of the light-emitting device 1 will be described with reference to Figure 1. This light-emitting device 1 is of the top-emission type. The light-emitting device 1 comprises a support substrate 2, a transparent substrate 3 that is spaced apart from and opposite to the support substrate 2, a light-emitting element 4 located on the surface of the support substrate 2 that faces 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 from, for example, a resin material, but is not limited thereto. The transparent substrate 3 is made from a light-transmitting material. The transparent substrate 3 is, for example, a glass substrate or a transparent resin substrate. The light-emitting element 4 comprises, for example, a pair of electrodes 41 and 43 and an organic light-emitting layer 42 between the electrodes 41 and 43. The organic light-emitting layer 42 comprises, for example, a hole injection layer 421, a hole transport layer 422, an organic light-emitting layer 423, and an electron transport layer 424, and these layers are stacked in the order described above.

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

[0035] The passivation layer 6 is preferably made from silicon nitride or silicon oxide, and is particularly preferably made from silicon nitride. In the example shown in Figure 1, the passivation layer 6 includes a first passivation layer 61 and a second passivation layer 62. The first passivation layer 61 covers the light-emitting element 4 by covering the element array 9 while in direct contact with the element array 9. The second passivation layer 62 is positioned on the opposite side of the element array 9 from the first passivation layer 61, and there is a gap between the second passivation layer 62 and the first passivation layer 61. The sealing material 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 element 4 and the sealing material 5 that covers the light-emitting element 4.

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

[0038] The encapsulant 5 in the light-emitting device 1 having the structure illustrated above can be made from composition (X). That is, composition (X) is used to make the encapsulant 5 for the light-emitting element 4. To put it another way, composition (X) is preferably a composition for making an encapsulant, a composition for encapsulating a light-emitting element, or a composition for manufacturing 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, the photopolymerization initiator (B) initiates a photoradical polymerization reaction, causing the acrylic compound (A) to harden and produce a cured product. The components of composition (X) are described in more detail below.

[0040] As described above, composition (X) contains acrylic compound (A). 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 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. Alternatively, 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 make the composition (X) particularly low viscosity when heated. It is even more preferable that the viscosity of the entire acrylic compound (A) is 30 mPa·s or less, even more preferable that it is 25 mPa·s or less, and particularly preferable that it is 20 mPa·s or less. Furthermore, the viscosity of the entire acrylic compound (A) is, for example, 3 mPa·s or more.

[0043] This section describes the compounds that acrylic compound (A) may contain.

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

[0045] The percentage of acrylic compound (A1) to acrylic compound (A) is 50% by mass or more. Therefore, acrylic compound (A1) can effectively lower the refractive index of the cured product. It is preferable that the percentage of acrylic compound (A1) is 55% by mass or more. Furthermore, the percentage of acrylic compound (A1) to 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 composition (X) during storage and when composition (X) is heated. Therefore, the storage stability of 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 in the light-emitting device 1, for example, between the sealant 5 and the passivation layer 6. If there are voids in the light-emitting device 1, moisture may reach the light-emitting element 4 through the voids, but if voids are less likely to occur, moisture is less likely to reach the light-emitting element 4, and thus the light-emitting element 4 is less likely to deteriorate due to moisture. The boiling point is the boiling point under normal pressure obtained by converting the boiling point under reduced pressure, and can be determined by the method shown, for example, Science of Petroleum, Vol. II. P. 1281 (1938). The boiling point of the acrylic compound (A1) is more preferably 280°C or higher, even more preferably 290°C or higher, and particularly preferably 300°C or higher.

[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 lower the viscosity of 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. Furthermore, 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. In this case, the acrylic compound (A1) can raise the glass transition temperature of the cured product, thereby improving the heat resistance of the cured product and the sealant 5.

[0049] The acrylic compound (A1) may contain appropriate compounds having a refractive index of 1.459 or less, or further satisfying one or more of the above preferred conditions.

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

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

[0052] The number of carbon atoms in the alkylene glycol in the polyalkylene glycol di(meth)acrylic acid ester is, for example, 2 to 4. The polyalkylene glycol includes, for example, at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. The more carbon atoms the polyalkylene glycol has, the higher the hydrophobicity of the cured product and the sealant 5, making it more difficult for moisture to permeate the sealant 5. For this reason, the polyalkylene glycol is particularly preferably 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. The polyalkylene glycol di(meth)acrylic acid ester preferably 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 polyalkylene glycol di(meth)acrylic acid ester contains at least one compound selected from the group consisting of product numbers SR230 and SR508NS from Sartomer, DPGDA, SR306NS, and TPGDA from Daicel, V310HP from Osaka Organic Chemical Industry, APG200 from Shin-Nakamura Chemical Industry, Light Acrylate PTMGA-250 from Kyoei Chemical Industry Co., Ltd., SR231NS from Sartomer, Light Ester 2EG from Kyoei Chemical Industry, SR205NS from Sartomer, Light Ester 3EG from Kyoei Chemical Industry, Acryester HX from Mitsubishi Chemical Corporation, and 3PG from Shin-Nakamura Chemical Industry Co., Ltd.

[0053] Di(meth)acrylic acid esters of alkylene oxide-modified alkylene glycol include, for example, propylene oxide-modified neopentyl glycol. Di(meth)acrylic acid esters of alkylene oxide-modified alkylene glycol also include, for example, Daicel Corporation's product code EBECRYL145.

[0054] The acrylic compound (A) may further contain a polyfunctional acrylic compound (A2) other than the acrylic compound (A1) described above. 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, and thus can improve the heat resistance of the cured product and the sealant 5. The polyfunctional acrylic compound (A2) contains, for example, at least one component selected from the group consisting of polyalkylene glycol di(meth)acrylic acid esters with a refractive index higher than 1.459, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, and triethylene glycol diacrylate. Di(meth)acrylic acid esters of polyalkylene glycols with a refractive index higher than 1.459 may contain at least one compound selected from the group consisting of, for example, 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 composition (X) during storage and when composition (X) is heated. Therefore, the storage stability of composition (X) is less likely to be impaired. Furthermore, even if the polyfunctional acrylic compound (A2) remains unreacted in the cured product and the sealant 5, outgassing caused by the polyfunctional acrylic compound (A2) is less likely to occur from the cured product and the sealant 5. Therefore, voids due to outgassing are less likely to occur in the light-emitting device 1, for example, between the sealant 5 and the passivation layer 6. If there are voids in the light-emitting device 1, there is a risk that moisture will reach the light-emitting element 4 through the voids, but if voids are less likely to occur, moisture is less likely to reach the light-emitting element 4, and thus the light-emitting element 4 is less likely to deteriorate due to moisture. The boiling point of the polyfunctional acrylic compound (A2) is more preferably 280°C or higher. The definition of the boiling point for polyfunctional acrylic compound (A2) is the same as the definition of the boiling point for acrylic compound (A1).

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

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

[0058] When acrylic compound (A) contains compound (A3), the percentage of compound (A3) to acrylic compound (A) is preferably more than 0% by mass and 25% by mass or less. A percentage of compound (A3) of 10% by mass or more is more preferable. In this case, the glass transition temperature of the cured product can be particularly increased. Furthermore, if compound (A3) is 25% by mass or less, an increase in viscosity of composition (X) due to compound (A3) is less likely to occur. If the percentage of compound (A3) is 20% by mass or less, an increase in viscosity of composition (X) is particularly unlikely to occur.

[0059] 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 during curing of composition (X). Furthermore, the monofunctional acrylic compound (A4) can contribute to reducing the viscosity of composition (X). However, since the monofunctional acrylic compound (A4) tends to increase the refractive index of composition (X), in order to lower the refractive index of composition (X), it is preferable that acrylic compound (A) does not contain the monofunctional acrylic compound (A4), or that the amount of the monofunctional acrylic compound (A4) in acrylic compound (A) is such that it does not excessively increase the refractive index of composition (X). When acrylic compound (A) contains the monofunctional acrylic compound (A4), it is preferable that the amount of the monofunctional acrylic compound (A4) relative to the total amount of acrylic compound (A) is more than 0% by mass and 30% by mass or less. If the amount of the monofunctional acrylic compound (A4) is greater than 0% by mass, shrinkage during curing of composition (X) can be suppressed. Furthermore, if the amount of monofunctional acrylic compound (A4) is 30% by mass or less, an increase in the refractive index of composition (X) due to monofunctional acrylic compound (A4) is unlikely to occur.

[0060] Monofunctional acrylic compounds (A4) include, for example, tetrahydrofurfuryl acrylate, isoboronyl 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, methoxydioxyethyl acrylate. Tyl acrylate, ethyl diglycol acrylate, cyclic trimethylolpropane formal monoacrylate, imide acrylate, isoamyl acrylate, ethoxylated succinate 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-methacryloyloxymethylcyclohexene oxide, and 3-acryloyloxymethylcyclohexene oxide.

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

[0062] Note that compound (A5) is defined solely by the types of atoms in its molecular framework. Therefore, the compounds included in acrylic compound (A1), polyfunctional acrylic compound (A2), acrylic compound (A3), and monofunctional acrylic compound (A4) may overlap with the compounds included in compound (A5).

[0063] Compounds having silicon in their molecular skeleton include, for example, at least one compound selected from the group consisting of 3-(trimethoxysilyl)propyl acrylate (e.g., Shin-Etsu Chemical Co., Ltd., product code KBM5103) and (meth)acrylic group-containing alkoxysilane oligomers (e.g., Shin-Etsu Chemical Co., Ltd., product code KR-513). The boiling point of the compound having silicon in its molecular skeleton is preferably 270°C or higher. Furthermore, the compound having silicon in its molecular skeleton is also preferably a polyfunctional compound. Therefore, 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, and more preferably 1% by mass or less. It is also preferable that the percentage of the compound having silicon in its molecular skeleton be 20% by mass or less.

[0065] Composition (X) may further contain a radical polymerizable compound (E) other than the acrylic compound (A). The radical polymerizable compound (E) may contain either or both of the following: a polyfunctional radical polymerizable compound (E1) having two or more radical polymerizable functional groups in one molecule, and a monofunctional radical polymerizable compound (E2) having only one radical polymerizable functional group in one molecule. The amount of the radical polymerizable compound (E) relative to the total amount of the acrylic compound (A) and the radical polymerizable compound (E) is, for example, 10% by mass or less. The polyfunctional radical 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 having two or more ethylenic double bonds in one molecule. The monofunctional radical polymerizable compound (E2) contains, for example, at least one compound selected from the group consisting of N-vinylformamide, vinylcaprolactam, vinylpyrrolidone, phenylglycidyl ether, p-tert-butylphenylglycidyl ether, butylglycidyl ether, 2-ethylhexylglycidyl ether, allylglycidyl ether, 1,2-butylene oxide, 1,3-butadiene monooxide, 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, for example, at least one compound selected from the group consisting of aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds (thioxanthone compounds, thiophenyl group-containing compounds, etc.), hexaarylbiimidazole compounds, ketoxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having carbon-halogen bonds, 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 part of the photopolymerization initiator (B). The sensitizer can promote the radical generation reaction of the photopolymerization initiator (B), thereby improving the reactivity of radical polymerization and increasing the crosslinking density. The sensitizer may contain at least one compound selected from the group consisting of, for example, 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 amount of sensitizer in composition (X) is, for example, 0.1 parts by mass or more and 5 parts by mass or less, preferably 0.1 parts by mass or more and 3 parts by mass or less, per 100 parts by mass of solid content of composition (X). If the amount of 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] Composition (X) may contain a polymerization accelerator in addition to the photopolymerization initiator (B). The polymerization accelerator may contain amine compounds 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). The hollow filler (C) can reduce the refractive index of the composition (X).

[0071] The average particle size of the hollow filler (C) is preferably 150 nm or less. In this case, the hollow filler (C) is less likely to reduce the transparency of the cured product and the sealant 5. The average particle size of the hollow filler (C) is more preferably 10 nm to 100 nm, and even more preferably 20 nm to 80 nm. The average particle size of the hollow filler (C) is the median diameter calculated from the measurement results by dynamic light scattering. As the measuring device, the Nanotrac Wave series from Microtrac-Bell Co., Ltd. can be used.

[0072] The hollowness ratio of the hollow filler (C) is preferably 30% to 70%. In this 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 sealant 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 light transmittance of the cured product and optical components is less likely to be impaired by the hollow filler (C).

[0075] The hollow filler (C) preferably contains hollow resin particles. Compared to hollow silica particles, hollow resin particles are less prone to breakage when force is applied. Therefore, even if force is applied to the hollow resin particles during processes such as kneading when preparing the composition (X) containing hollow resin particles, and during the process of making the sealant 5 from the composition (X), the hollow resin particles are less likely to break. As a result, the refractive index of the sealant 5 is easily maintained at a low level. The hollow resin particles are made of acrylic resin, for example, hollow acrylic particles.

[0076] Hollow silica particles can contain, for example, catalloid-Si manufactured by JGC Catalysts & Chemicals. Hollow acrylic particles can contain, for example, Techpolymer NH series manufactured by Sekisui Chemicals Co., Ltd.

[0077] When composition (X) contains a hollow filler (C), the percentage of hollow filler (C) to composition (X) is preferably more than 0% by volume and 7% or less by volume. When the percentage of hollow filler (C) is 7% by volume or less, an increase in the viscosity of composition (X) due to the hollow filler (C) is unlikely to occur.

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

[0079] The desiccant (D) is preferably an inorganic particle having hygroscopic properties, and preferably contains at least one component selected from the group consisting of, for example, zeolite particles, silica gel particles, calcium chloride particles, and titanium oxide nanotube particles. It is particularly preferable that the desiccant (D) contains zeolite particles.

[0080] Zeolite particles with an average particle size of 200 nm or less can be produced, for example, by pulverizing general industrial zeolite. In producing zeolite particles, the zeolite may be pulverized and then crystallized by hydrothermal synthesis or the like, in which case the zeolite particles can have particularly high hygroscopic properties. Examples of such methods for producing zeolite particles are disclosed in Japanese Patent Publication No. 2016-69266 and Japanese Patent Publication No. 2013-049602, among others.

[0081] When composition (X) contains a desiccant (D), the proportion of the desiccant (D) to the total amount of composition (X) is preferably 1% by mass or more and 20% by mass or less. If the proportion of the desiccant (D) is 1% by mass or more, the cured product can have particularly high hygroscopicity. Furthermore, if the proportion of the desiccant (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 to be applied by inkjet printing. The proportion of the desiccant (D) is more preferably 3% by mass or more, and particularly preferably 5% by mass or more. Furthermore, the proportion of the desiccant (D) is more preferably 15% by mass or less, and particularly preferably 13% by mass or less.

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

[0084] The dispersant (E) is a surfactant that can adsorb to particles. The dispersant (E) has an adsorption group (generally also called an anchor) that can be adsorbed to particles, and a molecular skeleton (generally also called a tail) that adheres to the particles when the adsorption group is adsorbed to them. 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 at least one of, for example, a basic polar functional group and an acidic polar functional group. The basic polar functional group includes at least one group selected from the group consisting of, for example, an amino group, an imino group, an amide group, an imide group, and a nitrogen-containing heterocyclic group. The acidic polar functional group includes at least one group selected from the group consisting of, for example, 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 Solspers series manufactured by Nippon Ruble Resol Co., Ltd., the DISPERBYK series manufactured by BIC Chemie Japan Co., Ltd., and the Azisper series manufactured by Ajinomoto Fine Techno Co., Ltd.

[0085] If composition (X) contains a hollow filler (C), the amount of dispersant (E) relative to the hollow filler (C) is preferably 5 parts by mass or more and 60 parts by mass or less. If composition (X) contains a hygroscopic agent (D), the amount of dispersant (E) relative to the hygroscopic agent (D) is preferably 5 parts by mass or more and 60 parts by mass or less. If composition (X) contains both a hollow filler (C) and a hygroscopic agent (D), the amount of dispersant (E) relative to the total of the hollow filler (C) and the hygroscopic agent (D) is preferably 5 parts by mass or more and 60 parts by mass or less. In any case, if the amount of dispersant (E) is 5 parts by mass or more, the function of the dispersant (E) can be effectively expressed, and if it is 60 parts by mass or less, it is possible to suppress the free molecules of dispersant (E) in the sealing material 5 from hindering the adhesion between the sealing material 5 and the inorganic material component. Furthermore, in all cases, 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 composition (X) does not contain a solvent. In this case, it is not necessary to dry composition (X) to evaporate the solvent when preparing a cured product from composition (X). Furthermore, the storage stability of composition (X) is further improved.

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

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

[0089] In this embodiment, it is preferable to produce the encapsulant 5 by forming the composition (X) using an inkjet method and then curing the composition (X) by irradiating it with ultraviolet light. In this embodiment, it is possible to apply and form the composition (X) using an inkjet method.

[0090] When applying composition (X) by 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, and particularly 15 mPa·s or less, then composition (X) can be molded by applying it by inkjet method without heating.

[0091] If composition (X) has the property of becoming less viscous when heated, composition (X) may be heated and then coated and molded using an inkjet method. If the viscosity of composition (X) at 40°C is 30 mPa·s or less, particularly 15 mPa·s or less, the viscosity of composition (X) can be reduced by slight heating, and this reduced-viscosity composition (X) can be ejected using an inkjet method. The heating temperature of composition (X) is, for example, 20°C to 50°C.

[0092] More specifically, for example, first a support substrate 2 is prepared. A partition wall 7 is fabricated on one surface of this support substrate 2 using a photolithography method, for example, with a photosensitive resin material. Subsequently, a plurality of light-emitting elements 4 are placed on one surface of the support substrate 2. The light-emitting elements 4 can be fabricated by appropriate methods such as vapor deposition or coating. It is particularly preferable to fabricate the light-emitting elements 4 using a coating method such as inkjet. This creates an element array 9 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 fabricated by a deposition method such as plasma CVD.

[0094] Next, a coating film is prepared by forming the composition (X) on the first passivation layer 61, for example, by an inkjet method. Applying the inkjet method to both the formation of the light-emitting element 4 and the coating of the composition (X) can particularly improve the manufacturing efficiency of the light-emitting device 1. Subsequently, the coating film is cured by irradiating it with ultraviolet light to prepare a sealant 5. The thickness of the sealant 5 is, for example, 5 μm to 50 μm.

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

[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 onto the transparent substrate 3 from the outside. The ultraviolet light penetrates the transparent substrate 3 and reaches the ultraviolet-curable resin material. As a result, the ultraviolet-curable resin material hardens, and the second encapsulant 52 is produced.

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

[0099] The thickness of the sealing material 5 is, for example, 1 μm to 20 μm. The thickness of the sealing material 5 may be 15 μm or less. In this case, by making the sealing material 5 thinner, the light-emitting device 1 can be made thinner, and it is also possible to obtain a light-emitting device 1 with flexibility. Furthermore, even if the thickness of the sealing material 5 is 10 μm or less, in this embodiment, it is possible to make it less likely for a decrease in luminous efficiency caused by the passivation layer 6 and the sealing material 5 in the light-emitting device 1 to occur. A thickness of 8 μm or less for the sealing material 5 is more preferable. In addition, in order to effectively suppress moisture to the light-emitting element 4 by the sealing material 5, 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, 0.1 μm or more and 2 μm or less. When the passivation layer 6 includes a first passivation layer 61 and a 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 0.1 μm or more and 2 μm or less.

[0101] The refractive index of the encapsulating material 5 is preferably 70% to 80% 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 encapsulating material 5 is preferably 1.32 to 1.50. In this case, a decrease in luminous efficiency caused by the passivation layer 6 and the encapsulating material 5 in the light-emitting device 1 can be made particularly unlikely.

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

[0103] Furthermore, the use of composition (X) according to this embodiment is not limited to the production of a encapsulating material 5 for the light-emitting element 4. Composition (X) can be used to produce various optical components that transmit light emitted from a light source. For example, the optical component may be a color resist. That is, for example, a phosphor may be included in 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 are light-emitting devices. [Examples]

[0104] 1. Preparation of the composition The 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. Furthermore, the viscosity of each component below 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 These are values ​​measured under the following conditions.

[0106] (1) Acrylic compounds KBM5103: 3-(trimethoxysilyl)propyl acrylate, a monofunctional acrylic compound containing silicon atoms, manufactured by Shin-Etsu Chemical Co., Ltd., product code KBM5103, viscosity 4 mPa·s, refractive index 1.427, boiling point 260°C. KR513: An acrylic group-containing alkoxysilane oligomer, an acrylic compound having an average of three or more functions containing silicon atoms, with a viscosity of 50 mPa·s, a refractive index of 1.427, and a boiling point of 300°C or higher. • 3PG: Tris(propylene glycol) dimethacrylate, a bifunctional acrylic compound, manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product number 3PG, viscosity 13 mPa·s, glass transition temperature -8℃, refractive index 1.450, boiling point 400℃. APG200: Tris(propylene glycol) diacrylate, a bifunctional acrylic compound, manufactured by Shin-Nakamura Chemical Industry 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, catalog number SR297, viscosity 7 mPa·s, glass transition temperature 85°C, refractive index 1.449, boiling point 290°C. EBECRYL145: A bifunctional acrylic compound, propylene oxide-modified neopentyl glycol diacrylate, manufactured by Daicel Ornex, product code 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 Industry 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, viscosity 106 mPa·s, glass transition temperature 62°C, refractive index 1.472, boiling point above 300°C. TMPTMA: Trimethylolpropane trimethacrylate, a trifunctional acrylic compound, viscosity 44 mPa·s, glass transition temperature 27°C, refractive index 1.470, boiling point above 300°C. 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 Irgacure184: 1-Hydroxycyclohexylphenyl ketone, manufactured by BASF, product name Irgacure184. IrgacureTPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, manufactured by BASF, product name IrgacureTPO.

[0108] (3) Hollow filler • Hollow acrylic particles: Manufactured by Sekisui Chemical Co., Ltd., average particle size 80 nm, hollowness ratio 40%, refractive index 1.30, specific gravity 0.75. • Hollow silica particles: Manufactured by JGC Catalysts & Chemicals, average particle size 50 nm, hollowness 33%, refractive index 1.30, specific gravity 1.32. • Hollow silica particles 2: Manufactured by JGC Catalysts & 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 having amino and phosphate groups as adsorbents; amine value 31 mg KOH / g, acid value 15 mg KOH / g, viscosity 14000 mP·s, weight-average molecular weight 3900; manufactured by Lubrizol; catalog number SOLSPERSE32000.

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

[0111] (1) Transmittance The composition is applied to create a coating film, and this coating film is subjected to an LED-UV irradiator (peak wavelength 365nm) manufactured by Panasonic Electric Works Co., Ltd. at approximately 30mW / cm². 2A 10 μm thick film was fabricated by photocuring it with ultraviolet light for 50 seconds under the specified conditions. The transmittance of this film at a wavelength of 587.6 nm was measured using an ellipsometer (Filmtek3000, manufactured by SCI).

[0112] (2) Volatility The compositions were left standing in an argon atmosphere at 20°C (dew point temperature -70°C) for 24 hours. The percentage of weight loss of the compositions was measured. A weight loss of 0.5% or less was rated as "A", 0.5-1% as "B", and 1% or more as "C".

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

[0114] (4) Inkjet properties The composition was placed in a cartridge of an inkjet printer (Ricoh MH2420), and after confirming that the composition could be ejected from the nozzles of the inkjet printer, test patterns were continuously printed by ejecting the composition from the nozzles. The results were evaluated as follows: "A" if the composition could be ejected for 1 hour and the ejection operation was stable; "B" if the composition could be ejected for 1 hour but the ejection operation was intermittently unstable; and "C" if the nozzles became clogged and the composition could not be ejected before 1 hour had elapsed from the start of ejection.

[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.

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

[0117] (7) Glass transition temperature The composition is applied to create a coating film, and this coating film is subjected to an LED-UV irradiator (peak wavelength 365nm) manufactured by Panasonic Electric Works Co., Ltd. at approximately 30mW / cm². 2 Under these conditions, purple for 50 seconds A 200 μm thick film was fabricated by photocuring with external radiation. The glass transition temperature of a sample cut from this film was measured using a viscoelasticity analyzer (Hitachi High-Tech Science Corporation, model DMA7100).

[0118] (8) Adhesion A quartz glass piece (dimensions 76mm x 52mm x 1mm) was coated with the composition to form a 50μm thick coating, and another quartz glass piece (dimensions 76mm x 52mm x 1mm) was placed on top of this coating. Subsequently, the coating was treated with an LED-UV irradiator (peak wavelength 365nm) manufactured by Panasonic Electric Works Co., Ltd. at approximately 30mW / cm². 2 The material was cured by irradiating it with ultraviolet light for 50 seconds under these conditions. This resulted in obtaining a test specimen.

[0119] The test specimen was 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 performing a T-peel test according to JIS K6854. As a result, a result of 3 MPa or more was evaluated as "A", a result of less than 3 MPa was evaluated as "B", and a result of the quartz glass pieces peeling off and the adhesion strength not being measured was evaluated as "C".

[0120] (9) Evaluation of light extraction efficiency Two silicon nitride films with a thickness of 1 μm were fabricated on the surface of each of two quartz glass pieces (dimensions 76 mm × 52 mm × 1 mm) using plasma CVD to obtain two substrates. A composition was applied to the surface of the silicon nitride film on one substrate to form a coating with a thickness of 5 μm, and the silicon nitride film of the other substrate was placed on top of this coating. Subsequently, the coating was irradiated using an LED-UV irradiator (peak wavelength 365 nm) manufactured by Panasonic Electric Works Co., Ltd. at approximately 30 mW / cm². 2 The material was cured by irradiating it with ultraviolet light for 50 seconds under these conditions. This resulted in obtaining a test specimen.

[0121] The visible light transmittance of this test specimen was measured, and it was evaluated as "A" if the visible light transmittance was higher than that of Comparative Example 1, and "B" otherwise.

[0122] [Table 1]

[0123] [Table 2]

Claims

1. This is an ultraviolet-curable resin composition containing an acrylic compound (A) and a photopolymerization initiator (B). The refractive index of the UV-curable resin composition is 1.457 or less. The acrylic compound (A) contains an acrylic compound (A1) with a refractive index of 1.450 or less and a compound (A3) having three or more (meth)acryloyl groups in one molecule, and the percentage ratio of the acrylic compound (A1) to the acrylic compound (A) is 55% by mass or more. The acrylic compound (A1) contains a compound having two or more (meth)acryloyl groups in one molecule. A UV-curable resin composition for fabricating optical components that transmit light emitted from a light source.

2. 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.

3. Molded by inkjet method, The ultraviolet-curable resin composition according to claim 1 or 2.

4. The glass transition temperature of the cured product is 80°C or higher. The ultraviolet-curable resin composition according to any one of claims 1 to 3.

5. Further containing hollow filler (C), The ultraviolet-curable resin composition according to any one of claims 1 to 4.

6. The hollow filler (C) contains hollow resin particles. The ultraviolet-curable resin composition according to claim 5.

7. A method for manufacturing a light-emitting device comprising a light source, an optical component that transmits light emitted by the light source, and an inorganic layer, wherein the optical component and the inorganic layer overlap. The optical component is manufactured by molding the UV-curable resin composition according to any one of claims 1 to 6 by an inkjet method, and then curing the UV-curable resin composition by irradiating it with ultraviolet light. A method for manufacturing a light-emitting device.

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

9. The invention comprises a light source, an optical component that transmits light emitted by the light source, and an inorganic layer, wherein the optical component and the inorganic layer overlap, and the optical component is a cured product of the ultraviolet curable resin composition described in any one of claims 1 to 6. Light-emitting device.

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