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

Abstract

To provide an ultraviolet-curable resin composition that can be used to produce an optical component that transmits light emitted by a light source, and that can reduce the occurrence of a decrease in luminous 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 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. The percentage of the acrylic compound (A1) to the acrylic compound (A) is 55 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. 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 manufacturing a light emitting device using this ultraviolet curable resin composition, and a light emitting device including this optical component.

Background Art

[0002] Light emitting devices such as organic EL light emitting devices are applied to lighting, displays, etc., and are expected to spread in the future.

[0003] Among organic EL light emitting devices, those called top emission types are 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, the light emitted from the organic EL element passes through the transparent substrate and is emitted to the outside.

[0004] When an organic EL element deteriorates due to moisture, a non-light emitting portion called a dark spot may occur. Therefore, in order to suppress the intrusion of moisture from the outside into the organic EL element, the organic EL element is covered with a transparent sealing material and a passivation layer made of a nitrogen compound (see Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The organic EL light-emitting device is required not only to suppress dark spots but also to have high luminous efficiency. The inventors have found that providing a sealing material and a passivation layer in the organic EL light-emitting device causes a decrease in luminous efficiency, and particularly when the thickness of the sealing material is thin, the decrease in luminous efficiency becomes remarkable.

[0007] An object of the present invention is to provide an ultraviolet curable resin composition that can be used for producing an optical component that transmits light emitted from a light source, and that can hardly cause a decrease in luminous efficiency caused by an inorganic layer and an optical component in a light-emitting device, a method for manufacturing a light-emitting device using the ultraviolet curable resin composition, and a light-emitting device including an optical component made of a cured product of the ultraviolet curable resin composition. [Means for Solving the Problems]

[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). The acrylic compound (A) contains an acrylic compound (A1) having a refractive index of 1.459 or less, and the percentage of the acrylic compound (A1) with respect 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 including a light source, an optical component that transmits light emitted from the light source, and an inorganic layer, wherein the optical component and the inorganic layer overlap, and the method includes forming the ultraviolet curable resin composition by an inkjet method and then irradiating the ultraviolet curable resin composition with ultraviolet light to cure it to produce the optical component.

[0010] A light-emitting device according to one aspect of the present invention includes a light source, an optical component that transmits light emitted from 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] In one aspect of the present invention, when an ultraviolet curable resin composition is used to produce an optical component of a light-emitting device, there is an advantage that it is possible to hardly cause a decrease in luminous efficiency due to an inorganic layer and an optical component in the light-emitting device.

Brief Description of the Drawings

[0012]

Figure 1

Embodiments for Carrying Out the Invention

[0013] Hereinafter, an embodiment of the present invention will be described.

[0014] The ultraviolet curable resin composition (hereinafter, also referred to as composition (X)) for producing an optical component that transmits light emitted by 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) having a refractive index of 1.459 or less. The percentage of the acrylic compound (A1) with respect to the acrylic compound (A) is 50% by mass or more.

[0015] The composition (X) is used to produce an optical component that transmits light emitted by a light source. The optical component is a component for transmitting light emitted by a light source such as a light-emitting element in a device having an optical system (for example, the light-emitting device 1). The optical component is, for example, a sealing material 5 for a light-emitting element. The optical member is, for example, a thin film, and more specifically, a film having a thickness of 2 μm or more and 50 μm or less, or 2 μm or more and 30 μm or less.

[0016] In this embodiment, an optical component such as the encapsulant 5 of 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 the light emitted by the light source, and an inorganic layer, and the optical component and the inorganic layer overlap. In particular, in the light-emitting device 1 including the light-emitting element 4, the encapsulant 5 that covers the light-emitting element 4, and the passivation layer 6, and the encapsulant 5 and the passivation layer 6 overlap, it is preferable to produce the encapsulant 5 from the composition (X). In this case, the encapsulant 5 is an optical component, the light-emitting element 4 is a light source, and the passivation layer 6 is an inorganic layer. In this case, it is possible to less likely cause a decrease in the luminous efficiency due to the passivation layer 6 and the encapsulant 5 in the light-emitting device 1. This is considered to be because the composition (X) contains the acrylic compound (A1), and the encapsulant 5 made of the cured product of the composition (X) can have a refractive index moderately lower than that of the passivation layer 6 made of an inorganic material. That is, it is considered that the extraction efficiency of the light emitted from the light-emitting element 4 to the outside is increased by the interference of light in the passivation layer 6 and the encapsulant 5 caused by the refractive index difference between the encapsulant 5 and the passivation layer 6.

[0017] In addition, in this specification, the refractive index of the acrylic compound (A1) is 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 refractive index of the cured product of the composition (X) can have a refractive index equivalent to that of the composition (X). Note that due to curing shrinkage or the like, there may be a slight difference between the refractive index of the composition (X) and the refractive index of the cured product. In this case, light reflection is particularly unlikely to occur in the inorganic layer and the optical component.

[0019] In addition, in this specification, the refractive index of the composition (X) is 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 the composition (X) is 1.400 or more. The refractive index of the composition (X) is 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] Further, the refractive index of the cured product of the composition (X) is preferably 1.510 or less. In this case, light reflection 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 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 the cured product means 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 the composition (X) is preferably 80 °C or more. That is, the composition (X) preferably has the property of becoming a cured product with a glass transition temperature of 80 °C or more by curing. In this case, the cured product can have good heat resistance. Therefore, for example, when the cured product is subjected to a treatment accompanied by a temperature increase, the cured product is less likely to deteriorate. For this reason, for example, when an inorganic layer is formed on an optical component made from the composition (X) by a deposition method such as plasma CVD, even if the optical component is heated, the optical component is less likely to deteriorate. The glass transition temperature of the cured product is more preferably 90 °C or more, and even more preferably 100 °C or more. This glass transition temperature of the cured product can be achieved by the composition of the composition (X) described in detail below.

[0024] The viscosity of the composition (X) at 25 °C is preferably 1 mPa·s or more and 30 mPa·s or less. In this case, it is easy to mold the composition (X) by a method such as a casting method at room temperature, and it is also possible to mold the composition (X) 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 the composition (X) at 40°C is 1 mPa·s or more and 30 mPa·s or less. In this case, no matter what the viscosity of the composition (X) is at normal temperature, the composition (X) can be made to have a lower viscosity by slightly heating it. Therefore, by heating, it is easy to mold the composition (X) by a method such as the casting method, and it is also possible to mold the composition (X) by the inkjet method. In addition, since the composition (X) can be made to have a lower viscosity without significantly heating it, it is possible to less likely cause a change in the composition of the composition (X) due to the volatilization of the components in the composition (X). If this viscosity is 25 mPa·s or less, it is more preferable; if it is 20 mPa·s or less, it is even more preferable; if it is 15 mPa·s or less, it is particularly preferable. It is also preferable that this viscosity is 5 mPa·s or more.

[0026] Incidentally, the viscosity of the composition (X) is measured using a rheometer under the condition of a shear rate of 100 s -1 For example, the type number DHR-2 manufactured by Anton Paar Japan can be used as the rheometer.

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

[0028] When the thickness dimension of the cured product of the 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 light extraction efficiency of the light transmitted through the sealing material 5 and emitted to the outside can be particularly improved. Such light transmittance of the cured product can also be achieved by the composition of the composition (X) described in detail below.

[0029] Hereinafter, this embodiment will be described in more detail.

[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 the light emitted by the light source. For example, the light-emitting device 1 includes a light-emitting element 4, a sealing material 5 that covers 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 an inorganic layer. The sealing material 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 the light-emitting device 1 will be described with reference to FIG. 1. This light-emitting device 1 is of the top emission type. The 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 the 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, a resin material, but is not limited thereto. The transparent substrate 3 is made of a material having translucency. 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 and 43 and an organic light-emitting layer 42 between the electrodes 41 and 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, and these layers are laminated 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 the element array 9) on the support substrate 2. The element array 9 also includes partition walls 7. The partition walls 7 are on the support substrate 2 and partition between two adjacent light-emitting elements 4. The partition walls 7 are produced, for example, by molding a photosensitive resin material by photolithography. The element array 9 also includes connection wirings 8 that electrically connect the electrodes 43 and the electron transport layers 424 of adjacent light-emitting elements 4. The connection wirings 8 are provided on the partition walls 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 covers the element array 9 in a state of being in direct contact with the element array 9, thereby covering the light-emitting element 4. The second passivation layer 62 is disposed at a position opposite to the element array 9 with respect to the first passivation layer 61, and there is a gap between the second passivation layer 62 and the first passivation layer 61. A 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. is.

[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 that of the sealing material 5.

[0037] 2. Ultraviolet curable resin composition The ultraviolet curable resin composition according to the present embodiment (hereinafter also referred to as the 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. More specifically, the composition (X) is preferably a composition for producing an encapsulant, a composition for encapsulating a light-emitting element, or a composition for manufacturing a light-emitting device.

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

[0040] As described above, the composition (X) contains an 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). More preferably, the viscosity of the entire acrylic compound (A) is 30 mPa·s or less, still more preferably 25 mPa·s or less, and particularly preferably 20 mPa·s or less. Also, 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. More preferably, the viscosity of the entire acrylic compound (A) is 30 mPa·s or less, still more preferably 25 mPa·s or less, and particularly preferably 20 mPa·s or less. Also, 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.

[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 the composition (X) of 1.459 or less. It is more preferable that the refractive index of the acrylic compound (A1) is 1.456 or less, and still more preferably 1.450 or less. Further, 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) with respect 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. It is preferable that the percentage of the acrylic compound (A1) is 55% by mass or more. Further, the percentage of the acrylic compound (A1) with respect 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, when the composition (X) is stored and when the composition (X) is heated, the acrylic compound (A1) is less likely to volatilize from the composition (X). Therefore, the storage stability of the composition (X) is less likely to be impaired. Further, even if the acrylic compound (A1) remains unreacted in the cured product and in the encapsulant 5, outgas due to the acrylic compound (A1) is less likely to occur from the cured product and the encapsulant 5. Therefore, voids due to outgas are less likely to occur, for example, between the encapsulant 5 and the passivation layer 6 in the light-emitting device 1. If there are voids in the light-emitting device 1, there is a risk that 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, so 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 is determined, for example, by the method shown in Science of Petroleum, Vol. II. P. 1281 (1938). The boiling point of the acrylic compound (A1) is more preferably 280°C or higher, still 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 the composition (X). The viscosity of the acrylic compound (A1) at 25°C is more preferably 40 mPa·s or less, and still more preferably 25 mPa·s or less. Also, the viscosity of the acrylic compound (A1) at 25°C is, for example, preferably 1 mPa·s or more and 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 increase the glass transition temperature of the cured product, and thus can increase the heat resistance of the cured product and the encapsulant 5.

[0049] The acrylic compound (A1) has a refractive index of 1.459 or less, or can contain an appropriate compound that further satisfies one or more of the above 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)acry" means at least one of "acry" and "methacry".

[0051] The number of carbon atoms of the alkylene glycol in the di(meth)acrylic acid ester of alkylene glycol is preferably 2 to 12, more preferably 4 to 12. The alkylene glycol may be linear or may have a branch 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, 1,12-dodecanediol dimethacrylate. Also, the di(meth)acrylic acid ester of alkylene glycol is of product number SR213 manufactured by Sartomer Co., Ltd., manufactured by Osaka Organic Chemical Industry Co., Ltd. Preferably contains at least one compound selected from the group consisting of product number V195, product number SR212 manufactured by Sartomer, product number SR247 manufactured by Sartomer, product name Light Acrylate NP-A manufactured by Kyoei Chemical Industry Co., Ltd., product number SR238NS manufactured by Sartomer, product number V230 manufactured by Osaka Organic Chemical Industry Co., Ltd., product number HDDA manufactured by Daicel Corporation, product number 1,6HX-A manufactured by Kyoei Chemical Industry Co., Ltd., product number V260 manufactured by Osaka Organic Chemical Industry Co., Ltd., product number 1,9-ND-A manufactured by Kyoei Chemical Industry Co., Ltd., product number A-NOD-A manufactured by Shin-Nakamura Chemical Co., Ltd., and product number CD595 manufactured by Sartomer, product number SR214NS manufactured by Sartomer, product number BD manufactured by Shin-Nakamura Chemical 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 Co., Ltd., product name Light Ester 1,9ND manufactured by Kyoei Chemical Industry Co., Ltd., product number NOD-N manufactured by Shin-Nakamura Chemical Co., Ltd., product name Light Ester 1,10DC manufactured by Kyoei Chemical Industry Co., Ltd., product number DOD-N manufactured by Shin-Nakamura Chemical Co., Ltd., and product number SR262 manufactured by Sartomer.

[0052] The number of carbon atoms of the alkylene glycol in the di(meth)acrylate ester of polyalkylene glycol is, for example, 2 to 4. The polyalkylene glycol contains at least one selected from the group consisting of, for example, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. The larger the number of carbon atoms of the polyalkylene glycol, the higher the hydrophobicity of the cured product and the encapsulant 5, and it is difficult for moisture to permeate through the encapsulant 5. Therefore, 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 di(meth)acrylate ester of polyalkylene glycol preferably contains at least one compound selected from the group consisting of, in particular, 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. Further, the di(meth)acrylate ester of polyalkylene glycol preferably contains at least one compound selected from the group consisting of, in particular, product number SR230 manufactured by Sartomer, product number SR508NS manufactured by Sartomer, product number DPGDA manufactured by Daicel, product number SR306NS manufactured by Sartomer, product number TPGDA manufactured by Daicel, product number V310HP manufactured by Osaka Organic Chemical Industry Co., Ltd., product number APG200 manufactured by Shin-Nakamura Chemical Co., Ltd., product name Light Acrylate PTMGA-250 manufactured by Kyoei Chemical Industry Co., Ltd., product number SR231NS manufactured by Sartomer, product name Light Ester 2EG manufactured by Kyoei Chemical Industry Co., Ltd., product number SR205NS manufactured by Sartomer, product name Light Ester 3EG manufactured by Kyoei Chemical Industry Co., Ltd., product name Acryester HX manufactured by Mitsubishi Chemical Corporation, and product number 3PG manufactured by Shin-Nakamura Chemical Co., Ltd.

[0053] The di(meth)acrylate of alkylene oxide-modified alkylene glycol contains, for example, propylene oxide-modified neopentyl glycol. Further, the di(meth)acrylate of alkylene oxide-modified alkylene glycol contains, for example, product number 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 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 increase the heat resistance of the cured product and the encapsulant 5. The polyfunctional acrylic compound (A2) is, for example, a di(meth)acrylate of a polyalkylene glycol having a refractive index higher than 1.459, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, triethylene glycol diacrylate, or contains at least one component selected from the group consisting of. The di(meth)acrylate of a polyalkylene glycol having a refractive index higher than 1.459 can 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, when the composition (X) is stored and when the composition (X) is heated, the polyfunctional acrylic compound (A2) is less likely to volatilize from the composition (X). Therefore, the storage stability of the composition (X) is less likely to be impaired. Further, even if the polyfunctional acrylic compound (A2) remains unreacted in the cured product and the encapsulant 5, outgas due to the polyfunctional acrylic compound (A2) is less likely to be generated from the cured product and the encapsulant 5. Therefore, voids due to outgas are less likely to be generated, for example, between the encapsulant 5 and the passivation layer 6 in the light-emitting device 1. 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. However, if voids are less likely to be generated, moisture is less likely to reach the light-emitting element 4, so the light-emitting element 4 is less likely to be deteriorated by moisture. 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 each of the acrylic compound (A1) and the polyfunctional acrylic compound (A2) and the compounds contained in the compound (A3) may overlap.

[0057] The compound (A3) can contain at least one selected from the group consisting of, for example, 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. Therefore, the heat resistance of the cured product and the encapsulant 5 can be particularly increased.

[0058] When the acrylic compound (A) contains the compound (A3), the percentage of the compound (A3) with respect to the acrylic compound (A) is preferably more than 0% by mass and 25% by mass or less. More preferably, the percentage of the compound (A3) is 10% by mass or more. In this case, the glass transition temperature of the cured product can be particularly increased. Further, 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 less likely to occur. If 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 in one molecule. The monofunctional acrylic compound (A4) can suppress the shrinkage during curing of the composition (X). Further, 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), for reducing the refractive index of the composition (X), the acrylic compound (A) preferably does not contain the monofunctional acrylic compound (A4), or the amount of the monofunctional acrylic compound (A4) in the acrylic compound (A) is an amount that does not excessively increase the refractive index of the composition (X). When the acrylic compound (A) contains the monofunctional acrylic compound (A4), the amount of the monofunctional acrylic compound (A4) with respect to the total amount of the acrylic compound (A) is preferably more than 0% by mass and 30% by mass or less. If the amount of the monofunctional acrylic compound (A4) is more than 0% by mass, the shrinkage during curing of the composition (X) can be suppressed. Further, if the amount of the monofunctional acrylic compound (A4) is 30% by mass or less, an increase in the refractive index of the composition (X) due to the monofunctional acrylic compound (A4) is unlikely to occur.

[0060] The monofunctional acrylic compound (A4) is, for example, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, isobutyl acrylate, t-butyl acrylate, isooctyl acrylate, 2-methoxyethyl acrylate, methoxy triethylene glycol acrylate, 2-ethoxyethyl acrylate, 3-methoxybutyl acrylate, ethoxyethyl acrylate, butoxyethyl acrylate, ethoxydiethylene glycol acrylate, methoxydiglycol ethyl acrylate, ethyldiglycol 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) nonylphenol 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 sealing material 5 and the member made of an inorganic material is improved. Therefore, a gap is less likely to occur between the sealing material 5 and the passivation layer 6, and moisture is less likely to penetrate into the light-emitting element 4 through this gap.,

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

[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 (for example, product number KBM5103 manufactured by Shin-Etsu Chemical Co., Ltd.) and (meth)acrylic group-containing alkoxysilane oligomer (for example, 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. 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, acrylic The percentage of the compound having silicon in its molecular skeleton with respect 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 is 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) can contain either or both of a polyfunctional radically polymerizable compound (E1) having two or more radically polymerizable functional groups in one molecule and a monofunctional radically polymerizable compound (E2) having only one radically polymerizable functional group in one 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 an aromatic urethane oligomer, an aliphatic urethane oligomer, an epoxy acrylate oligomer, a polyester acrylate oligomer, and other special oligomers having two or more ethylenic double bonds in one 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 photoinitiator (B) is not particularly limited as long as it is a compound that generates radical species when irradiated with ultraviolet rays. The photoinitiator (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 (such as thioxanthone compounds and thiophenyl group-containing compounds), hexaarylbiimidazole compounds, ketooxime ester compounds, borate compounds, azinium compounds, metallocene compounds, active ester compounds, compounds having a carbon-halogen bond, and alkylamine compounds. The amount of the photoinitiator (B) relative to 100 parts by mass of the composition (X) is, for example, 1 part by weight or more and 10 parts by weight or less.

[0067] The photoinitiator (B) may contain a sensitizer as part of this photoinitiator (B). The sensitizer can promote the radical generation reaction of the photoinitiator (B), improve the reactivity of radical polymerization, and improve the crosslink density. The sensitizer contains, 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 the composition (X) is, for example, 0.1 part by mass or more and 5 parts by mass or less, preferably 0.1 part by mass or more and 3 parts by mass or less, based on 100 parts by mass of the solid content of the composition (X). If the content of the sensitizer is within such a range, the composition (X) can be cured in air, and it is not necessary to cure the composition (X) under an inert atmosphere such as a nitrogen atmosphere.

[0069] In addition to the photoinitiator (B), the composition (X) may contain a polymerization accelerator. Examples of the polymerization accelerator include amine compounds such as ethyl p-dimethylaminobenzoate, 2-ethylhexyl p-dimethylaminobenzoate, methyl p-dimethylaminobenzoate, 2-dimethylaminoethyl benzoate, and 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 diameter 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 encapsulant 5. More preferably, the average particle diameter of the hollow filler (C) is 10 nm or more and 100 nm or less, and even more preferably 20 nm or more and 80 nm or less. The average particle diameter of the hollow filler (C) is the median diameter calculated from the measurement results by the dynamic light scattering method. As the measuring device, the Nanotrac Wave series of Microtrac Bell Corporation can be used.

[0072] The hollow ratio of the hollow filler (C) is preferably 30% or more and 70% or less. 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 encapsulant 5. More preferably, the refractive index of the hollow filler (C) is 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 the optical component is particularly unlikely to be impaired by the hollow filler (C).

[0075] The hollow filler (C) particularly preferably contains hollow resin particles. Hollow resin particles are less likely to break when a force is applied compared to hollow silica particles. Therefore, even when a force is applied to the hollow resin particles during the kneading process and the like when preparing the composition (X) containing the hollow resin particles and the process of producing the sealing material 5 from the composition (X), the hollow resin particles are less likely to break. For this reason, the refractive index of the sealing material 5 is likely to be maintained low. The hollow resin particles are made of, for example, an acrylic resin, that is, for example, hollow acrylic particles.

[0076] The hollow silica particles can contain, for example, Cataloid-Si manufactured by JGC Catalysts and Chemicals Ltd. The hollow acrylic particles can contain, for example, Tech Polymer NH series manufactured by Sekisui Chemical Co., Ltd.

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

[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 sealing material 5, which is an optical component, can make it more difficult for moisture to further penetrate 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 an inorganic particle having hygroscopicity, 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 preferable 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 general industrial zeolite. When producing zeolite particles, the zeolite may be pulverized and then crystallized by hydrothermal synthesis or the like. In this case, the zeolite particles can particularly have high hygroscopicity. Examples of such production methods of zeolite particles are disclosed in JP-A-2016-69266, JP-A-2013-049602, and the like.

[0081] When the composition (X) contains the moisture absorbent (D), the ratio of the moisture absorbent (D) to the total amount of the composition (X) is preferably 1% by mass or more and 20% by mass or less. If the ratio of the moisture absorbent (D) is 1% by mass or more, the cured product can particularly have high hygroscopicity. Also, if the ratio of the moisture absorbent (D) is 20% by mass or less, the viscosity of the composition (X) can be particularly reduced, and the composition (X) can also have a sufficiently low viscosity that can be applied by an inkjet method. The ratio of the moisture absorbent (D) is more preferably 3% by mass or more, and particularly preferably 5% by mass or more. Also, the ratio of the 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 the 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, in the composition (X), an increase in viscosity and a decrease in storage stability due to the hollow filler (C) are less likely to occur.

[0083] Even when the composition (X) contains a 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, in the composition (X), an increase in viscosity and a decrease in storage stability due to the moisture absorbent (D) are less likely to occur.

[0084] The dispersant (E) is a surfactant that can adsorb to particles. The dispersant (E) has an adsorption group (generally also referred to as an anchor) that can be adsorbed to particles and a molecular skeleton (generally also referred to as a tail) that adheres to the particles when the adsorption group is adsorbed 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 contains at least one of, for example, a basic polar functional group and an acidic polar functional group. The basic polar functional group contains 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 contains at least one group selected from the group consisting of, for example, a carboxyl group and a phosphate group. The dispersant (E) can contain at least one compound selected from the group consisting of, for example, the Solsperse series manufactured by Nippon Lubrizol Corporation, the DISPERBYK series manufactured by BYK-Chemie Japan Co., Ltd., and the AJISPER series manufactured by Ajinomoto Fine-Techno Co., Ltd.

[0085] When the composition (X) contains a hollow filler (C), the amount of the dispersant (E) with respect to the hollow filler (C) is preferably 5 parts by mass or more and 60 parts by mass or less. When the composition (X) contains a moisture absorbent (D), the amount of the dispersant (E) with respect to the moisture absorbent (D) is preferably 5 parts by mass or more and 60 parts by mass or less. When the composition (X) contains a hollow filler (C) and a moisture absorbent (D), the amount of the dispersant (E) with respect to the total of the hollow filler (C) and the moisture absorbent (D) is preferably 5 parts by mass or more and 60 parts by mass or less. In any case, the dispersant ( When the amount of (E) is 5 parts by mass or more, the function of the dispersant (E) can be effectively exhibited, and when it is 60 parts by mass or less, it is possible to suppress the inhibition of the adhesion between the free molecules of the dispersant (E) in the encapsulant 5 and the member made of an inorganic material. Also, in any case, the amount of the 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] The composition (X) preferably does not contain a solvent. In this case, when producing a cured product from the composition (X), there is no need to dry the composition (X) to volatilize the solvent. Also, the storage stability of the composition (X) is further enhanced.

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

[0088] 3. Method for Producing Encapsulant and Method for Manufacturing Organic EL Light-Emitting Device A method for producing the encapsulant 5 using the composition (X) and a method for manufacturing the light-emitting device 1 will be described.

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

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

[0091] When the composition (X) has the property of decreasing its viscosity upon heating, the composition (X) may be heated and then applied by an inkjet method for forming. When the viscosity of the composition (X) at 40 °C is 30 mPa·s or less, particularly 15 mPa·s or less, the composition (X) can be made to have a decreased viscosity by merely heating slightly, and this composition (X) with decreased viscosity can be ejected by an inkjet method. The heating temperature of the 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, a partition wall 7 is formed by, for example, a photolithography method using a photosensitive resin material. Subsequently, 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 an evaporation 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. Thereby, 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 fabricated by an evaporation method such as a plasma CVD method, for example.

[0094] Next, the composition (X) is formed on the first passivation layer 61 by, for example, an inkjet method to produce a coating film. If the inkjet method is applied to both the formation of the light-emitting elements 4 and the coating of the composition (X), the manufacturing efficiency of the light-emitting device 1 can be particularly improved. Subsequently, the coating film is cured by irradiating ultraviolet rays to produce a sealing material 5. The thickness of the sealing material 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 fabricated by an evaporation method such as a plasma CVD method, for example.

[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 overlaid on this resin material. The transparent substrate 3 is, for example, a glass substrate or a transparent resin substrate.

[0097] Next, ultraviolet rays are irradiated from the outside toward the transparent substrate 3. The ultraviolet rays pass through the transparent substrate 3 and reach the ultraviolet curable resin material. As a result, the ultraviolet curable resin material is cured, and the second encapsulant 52 is produced.

[0098] In the present embodiment, as described above, it is possible to hardly cause a decrease in luminous efficiency due to the passivation layer 6 and the encapsulant 5 in the light-emitting device 1.

[0099] The thickness of the encapsulant 5 is, for example, 1 μm or more and 20 μm or less. The thickness of the encapsulant 5 may be 15 μm or less. In this case, by thinning the encapsulant 5, the light-emitting device 1 can be thinned, and it is also possible to obtain a flexible light-emitting device 1. Further, even if the thickness of the encapsulant 5 is 10 μm or less, in the present embodiment, it is possible to hardly cause a decrease in luminous efficiency due to the passivation layer 6 and the encapsulant 5 in the light-emitting device 1. It is more preferable that the thickness of the encapsulant 5 is 8 μm or less. Further, in order to effectively suppress moisture from reaching the light-emitting element 4 by the encapsulant 5, the thickness of the encapsulant 5 is preferably 3 μm or more, and more preferably 5 μm or more.

[0100] The thickness of the passivation layer 6 overlapping the encapsulant 5 is, for example, 0.1 μm or more and 2 μm or less. 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 0.1 μm or more and 2 μm or less.

[0101] The refractive index value of the sealing material 5 is preferably 70% or more and 80% or less of the refractive index value of the passivation layer 6. For example, when 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, it is possible to particularly hardly cause a decrease in luminous efficiency due to the passivation layer 6 and the sealing material 5 in the light-emitting device 1.

[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 (d line of helium).

[0103] Note that the use of the composition (X) according to the present embodiment is not limited to the production of the sealing material 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 in 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.

Examples

[0104] 1. Preparation of composition The compositions of the examples and comparative examples were prepared by mixing the components shown in the following table.

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

[0106] (1) Acrylic compound · KBM5103: 3-(Trimethoxysilyl)propyl acrylate, a monofunctional acrylic compound having a silicon atom, product number KBM5103 manufactured by Shin-Etsu Chemical Co., Ltd., viscosity 4 mPa·s, refractive index 1.427, boiling point 260 °C. · KR513: Acrylate group-containing alkoxysilane oligomer, an acrylic compound having an average of 3 or more functional groups with a silicon atom, viscosity 50 mPa·s, refractive index 1.427, boiling point 300 °C or higher. · 3PG: Tris(propylene glycol) dimethacrylate, a bifunctional acrylic compound, product number 3PG manufactured by Shin-Nakamura Chemical Co., Ltd., 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, 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, product number SR297 manufactured by Sartomer Company, 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, product number EBECRYL145 manufactured by Daicel Ornex Co., Ltd., 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, product number BD 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, viscosity 106 mPa·s, glass transition temperature 62 °C, refractive index 1.472, boiling point 300 °C or higher. · TMPTMA: Trimethylolpropane trimethacrylate, a trifunctional acrylic compound, viscosity 44 mPa·s, glass transition temperature 27 °C, refractive index 1.470, boiling point 300 °C or higher. · Pentaerythritol tetraacrylate: Viscosity 342 mPa·s, glass transition temperature 103 °C, refractive index 1.485, boiling point 300 °C or higher. · Polyethylene glycol 200 dimethacrylate: Viscosity 15 mPa·s, glass transition temperature -9 °C, refractive index 1.460, boiling point 350 °C.

[0107] (2) Photoinitiator · Irgacure 184: 1-Hydroxy-cyclohexyl-phenyl-ketone, manufactured by BASF, product 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 80 nm, hollowness 40%, refractive index 1.30, specific gravity 0.75. · Hollow silica particles: Manufactured by JGC Catalysts & Chemicals Ltd., average particle size 50 nm, hollowness 33%, refractive index 1.30, specific gravity 1.32. · Hollow silica particles 2: Manufactured by JGC Catalysts & Chemicals Ltd., average particle size 60 nm, hollowness 44%, refractive index 1.25, specific gravity 1.12.

[0109] (4) Dispersant · SOLSPERSE 32000: A wax-like comb-shaped dispersant having an amino group and a phosphate group as adsorption groups, amine value 31 mgKOH / g, acid value 15 mgKOH / g, viscosity 14000 mP·s, weight average molecular weight 3900, manufactured by Lubrizol Corporation, product number SOLSPERSE 32000.

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

[0111] (1) Transmittance The composition was applied to form a coating film, and this coating film was irradiated with an LED-UV irradiator (peak wavelength 365 nm) manufactured by Panasonic Electric Works Co., Ltd. at about 30 mW / cm2 Under the condition of irradiating with ultraviolet light for 50 seconds and photocuring, a film with a thickness of 10 μm was prepared. The transmittance of light with a wavelength of 587.6 nm of this film was measured using an ellipsometer (Filmtek 3000 manufactured by SCI).

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

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

[0114] (4) Inkjet property The composition was put into the cartridge of an inkjet printer (Ricoh MH2420). After confirming that the composition in the cartridge could be ejected from the nozzles in the inkjet printer, the composition was ejected from the nozzles to continuously print a test pattern. As a result, when the composition could be ejected for 1 hour and the ejection operation was stable, it was evaluated as "A", when the composition could be ejected for 1 hour but the ejection operation became intermittently unstable, it was evaluated as "B", and when the nozzles were clogged before 1 hour had passed since the start of ejection and the composition could not 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 number RA-620 manufactured by Kyoto Electronics).

[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 (Filmtek 3000 manufactured by SCI).

[0117] (7) Glass transition temperature The composition was applied to form a coating film, and this coating film was irradiated with ultraviolet light at about 30 mW / cm 2 for 50 seconds under the conditions of to be photocured, and a film with a thickness of 200 μm was prepared. The glass transition temperature of a sample cut out from this film was measured using a viscoelasticity measuring device (manufactured by Hitachi High-Technologies Corporation, model number DMA7100).

[0118] (8) Adhesion The composition was applied onto the surface of a quartz glass piece (dimensions: 76 mm × 52 mm × 1 mm) to form a coating film with a thickness of 50 μm, and another quartz glass piece (dimensions: 76 mm × 52 mm × 1 mm) was placed on top of this coating film. Subsequently, the coating film was irradiated with ultraviolet light at about 30 mW / cm 2 for 50 seconds under the conditions of to be cured, thereby obtaining a test piece.

[0119] This test piece was placed in a thermo-hygrostat 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 based on JIS K6854. As a result, when the adhesion strength was 3 MPa or more, it was evaluated as "A"; when the adhesion strength was less than 3 MPa, it was evaluated as "B"; and when the quartz glass pieces were peeled off and the adhesion strength could not be measured, it was evaluated as "C".

[0120] (9) Evaluation of light extraction efficiency A silicon nitride film with a thickness of 1 μm was formed on the surface of each of two quartz glass pieces (dimensions: 76 mm × 52 mm × 1 mm) by plasma CVD method to obtain two substrates. The composition was applied onto the surface of the silicon nitride film of one substrate to form a coating film with a thickness of 5 μm, and the silicon nitride film of the other substrate was placed on top of this coating film. Subsequently, the coating film was irradiated with ultraviolet light at about 30 mW / cm2 For 50 seconds under the conditions of It was cured by irradiating with ultraviolet rays for a period of time. As a result, test pieces were obtained.

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

[0122] [Table 1]

[0123] [Table 2]

Claims

1. An ultraviolet curable resin composition for producing an optical component that transmits light emitted by a light source, containing an acrylic compound (A) and a photopolymerization initiator (B). 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 the percentage of the acrylic compound (A1) with respect 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. The glass transition temperature of the cured product is 80°C or higher. An ultraviolet curable resin composition for producing an optical component that transmits light emitted by a light source.

2. An ultraviolet curable resin composition for producing an optical component that transmits light emitted by a light source, containing an acrylic compound (A) and a photopolymerization initiator (B). 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 the percentage of the acrylic compound (A1) with respect 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. Further containing a hollow filler (C). An ultraviolet curable resin composition for producing an optical component that transmits light emitted by a light source.

3. The hollow filler (C) contains hollow resin particles. The ultraviolet curable resin composition according to Claim 2.

4. Having a refractive index of 1.459 or less. The ultraviolet curable resin composition according to any one of Claims 1 to 3.

5. The viscosity of the acrylic compound (A1) at 25°C is 25 mPa·s or less. The ultraviolet curable resin composition according to any one of Claims 1 to 4.

6. Molded by an inkjet method. The ultraviolet curable resin composition according to any one of Claims 1 to 5.

7. 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, wherein the optical component and the inorganic layer overlap, including: manufacturing the optical component by molding an ultraviolet curable resin composition by an inkjet method and then irradiating the ultraviolet curable resin composition with ultraviolet light to cure it; 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 1.450 or less and a compound (A3) having three or more (meth)acryloyl groups in one molecule, and the percentage of the acrylic compound (A1) with respect 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. Method for manufacturing a light-emitting device.

8. After heating the ultraviolet curable resin composition, the ultraviolet curable resin composition is molded by an inkjet method. Method for manufacturing a light-emitting device according to Claim 7.

9. A light source, an optical component that transmits light emitted by the light source, and an inorganic layer are provided. The optical component and the inorganic layer overlap. The optical component is 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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