Composition, cured body, and display device

Abstract

Provided is a composition which contains a polymerizable compound (A) and a polymerization initiator (B), wherein a cured product of the composition has a storage elastic modulus E' of 0.5 to 5.0 GPa inclusive at 80°C when measured in a tensile mode with use of a dynamic viscoelasticity measurement device at a frequency of 1 Hz, for a measurement temperature range of 10°C to 200°C, at a heating rate of 2°C / min.

Description

Composition, cured product, and display device

[0001] The present invention relates to a composition, a cured product, and a display device.

[0002] 2. Description of the Related Art Display devices that include light-emitting diode elements and are sealed with a sealant are known. Patent Document 1, for example, describes a technique related to such sealants.

[0003] Patent Document 1 describes a curable composition for inkjet coating and for protecting LEDs, which contains a first polyfunctional (meth)acrylate compound having a plurality of (meth)acryloyl groups and an aliphatic cyclic skeleton, a second polyfunctional (meth)acrylate compound having a plurality of (meth)acryloyl groups and an alkylene oxide skeleton, and a photopolymerization initiator, and has a viscosity of 80 mPa·s to 2000 mPa·s at 25° C. Patent Document 1 describes that the curable composition for inkjet coating and for protecting LEDs in Patent Document 1 can maintain a good shape of the edge portions of the coated product when the curable composition is applied by an inkjet method to at least one of the gaps between a plurality of LED chips and the tops of a plurality of LED chips to form an LED protective layer.

[0004] International Publication No. 2022 / 050421

[0005] The present invention provides a composition capable of improving the reliability of a display device.

[0006] According to the present invention, there are provided a composition, a cured product, and a display device as shown below.

[0007] [1] A composition comprising a polymerizable compound (A) and a polymerization initiator (B), wherein a cured product of the composition has a storage modulus E' of 0.5 GPa or more and 5.0 GPa or less at 80°C when measured using a dynamic viscoelasticity measuring device at a frequency of 1 Hz, a temperature range of 10°C to 200°C, a heating rate of 2°C / min, and in tensile mode. [2] The composition according to [1], wherein a cured product of the composition has a storage modulus E' of 1.0 GPa or more and 10.0 GPa or less at 25°C when measured using a dynamic viscoelasticity measuring device at a frequency of 1 Hz, a temperature range of 10°C to 200°C, a heating rate of 2°C / min, and in tensile mode. [3] The composition according to [1] or [2], wherein the polymerizable compound (A) comprises a cationically polymerizable compound, and the polymerization initiator (B) comprises a cationic polymerization initiator. [4] The composition according to [3], wherein the cationically polymerizable compound comprises an epoxy compound. [5] The composition according to [4], wherein the epoxy compound comprises an alicyclic epoxy compound. [6] The composition according to any one of [3] to [5], wherein the cationic polymerization initiator comprises at least one selected from the group consisting of a photocationic polymerization initiator and a thermal cationic polymerization initiator. [7] The composition according to [1] or [2], wherein the polymerizable compound (A) comprises a radically polymerizable compound, and the polymerization initiator (B) comprises a radical polymerization initiator. [8] The composition according to [7], wherein the radically polymerizable compound comprises a (meth)acrylate. [9] The composition according to [7] or [8], wherein the radical polymerization initiator comprises a photoradical polymerization initiator.

[10] The composition according to any one of [1] to [9], further comprising a curing retarder (C).

[11] The composition according to any one of [1] to

[10] , wherein a cured product of the composition has a glass transition temperature of 70°C or higher when measured using a dynamic viscoelasticity measuring device at a frequency of 1 Hz, a heating rate of 2°C / min, and in tensile mode.

[12] The composition according to any one of [1] to

[11] , wherein a cured product of the composition has a refractive index of 1.45 to 1.70 at 25°C and 589 nm.

[13] The composition according to any one of [1] to

[12] , which is liquid at 25°C.

[14] The composition according to any one of [1] to

[13] above, wherein the viscosity of the composition is 1 mPa·s or more and 700 mPa·s or less, as measured by <Method 1> below. <Method 1> Apparatus: Cone-plate viscometer Temperature: 25°C Cone: Radius 24 mm, angle 0.8° Rotation speed: 250 rpm Sample amount: 0.5 mL Atmosphere: Air

[15] The composition according to any one of [1] to

[14] above, which can be used for inkjet coating or dispenser coating.

[16] The composition according to

[15] above, which can be used for inkjet coating.

[17] The composition according to any one of [1] to

[16] above, wherein the cure shrinkage calculated by <Method 2> below is 1.0% or more and 15.0% or less. <Method 2> A pycnometer is filled with the composition, and the liquid specific gravity is calculated by measuring the mass in the air and the mass in pure water. A cured product of the composition having a width of 25 mm, a length of 25 mm, and a thickness of 0.5 mm is measured in the air and in pure water to calculate the specific gravity of the cured product. The cure shrinkage is calculated using the formula: cure shrinkage = ((specific gravity of cured product - liquid specific gravity) / specific gravity of cured product) x 100 (%).

[18] The composition according to any one of [1] to

[17] above, having a static surface tension measured by a pendant drop method of 50 mN / m or less.

[19] The composition according to any one of [1] to

[18] above, which can be used to encapsulate a micro LED.

[20] A cured product comprising the cured product of the composition according to any one of [1] to

[19] above.

[21] A display device comprising: a light-emitting diode element; a substrate; and a cured encapsulating layer between the light-emitting diode element and the substrate, the cured product being the cured product according to

[20] above.

[22] The display device according to

[21] , wherein the light-emitting diode elements include micro LEDs.

[0008] According to the present invention, it is possible to provide a composition that can improve the reliability of a display device.

[0009] Hereinafter, embodiments of the present invention will be described. Unless otherwise specified, the numerical range "A to B" represents A or more and B or less. In this embodiment, the term "(meth)acrylate" represents a concept that includes both acrylate and methacrylate. The same applies to similar terms such as "(meth)acrylic."

[0010] Display devices that include light-emitting diode elements and are encapsulated with an encapsulant are known. Furthermore, display devices may be required to have reliability under high-temperature and high-humidity environments (e.g., 60°C and 90% RH). The present invention provides a composition that can improve the reliability of display devices.

[0011] [Composition] The composition of the present embodiment contains a polymerizable compound (A) and a polymerization initiator (B), and a cured product of the composition has a storage modulus E' at 80°C of 0.5 GPa or more and 5.0 GPa or less.

[0012] The present inventors have found that, in a composition containing a polymerizable compound (A) and a polymerization initiator (B), a measure of the storage modulus E' at 80°C of a cured product of the composition is effective as a design index for improving the reliability of display devices.

[0013] From the viewpoint of further improving the reliability of display devices, the storage modulus E' at 80°C of the cured product made from the composition of this embodiment is preferably 0.6 GPa or more and 4.5 GPa or less, more preferably 0.7 GPa or more and 4.0 GPa or less, even more preferably 0.8 GPa or more and 3.5 GPa or less, even more preferably 0.8 GPa or more and 3.0 GPa or less, and even more preferably 0.8 GPa or more and 2.8 GPa or less.

[0014] The storage modulus E' at 80°C of the cured product of the composition can be adjusted to a desired value, for example, by appropriately selecting the types of polymerizable compound (A) and polymerization initiator (B) and appropriately adjusting the content ratio of each component.

[0015] The storage modulus E' at 25°C of the cured product of the composition of this embodiment is preferably 1.0 GPa or more and 10.0 GPa or less, more preferably 1.2 GPa or more and 8.0 GPa or less, even more preferably 1.3 GPa or more and 6.0 GPa or less, and even more preferably 1.5 GPa or more and 5.0 GPa or less.

[0016] From the viewpoint of further improving the reliability of display devices, the glass transition temperature of the cured product of the composition of this embodiment is preferably 70° C. or higher, more preferably 73° C. or higher, even more preferably 75° C. or higher, even more preferably 78° C. or higher, and even more preferably 80° C. or higher, and the upper limit is not particularly limited, but may be, for example, 200° C. or lower, 180° C. or lower, or 170° C. or lower. From the viewpoint of further improving the reliability of display devices, the glass transition temperature of the cured product of the composition of this embodiment is preferably 70° C. or higher and 200° C. or lower, more preferably 73° C. or higher and 180° C. or lower, even more preferably 75° C. or higher and 170° C. or lower, even more preferably 78° C. or higher and 170° C. or lower, and even more preferably 80° C. or higher and 170° C.

[0017] The storage modulus E' at 80°C, the storage modulus E' at 25°C, and the glass transition temperature of a cured product made from the composition each refer to values ​​obtained when measured using a dynamic viscoelasticity measuring device at a frequency of 1 Hz, in a measurement temperature range of 10°C to 200°C (the glass transition temperature is a measurement temperature range of 10°C or higher), at a heating rate of 2°C / min, in a tensile mode.

[0018] The cured product of the composition of the present embodiment refers to a cured product in a C-stage state. When the composition is a cationically polymerizable composition, the cured product of the composition can be obtained, for example, by irradiating a 0.5 mm thick composition with ultraviolet light having a wavelength of 365 nm at a dose of 1500 mJ / cm using an LED lamp. ２and then heating at 80°C for 30 minutes. When the composition is a cationically polymerizable composition, a cured product of the composition can be produced, for example, by placing a silicone sheet mold with a thickness of 0.5 mm on a PET film, placing the composition in the mold, and sandwiching it between PET films. Next, the 0.5 mm thick composition is irradiated with ultraviolet light having a wavelength of 365 nm using an LED lamp at an irradiation dose of 1500 mJ / cm. ２ (100mW / cm ２ For example, a method of irradiating a 0.5 mm thick composition with ultraviolet light at a wavelength of 395 nm using an LED lamp at an irradiation dose of 1,500 mJ / cm is used, followed by heating at 80°C for 30 minutes to obtain a cured product of the composition. ２ When the composition is a radically polymerizable composition, a cured product of the composition can be produced, for example, by placing a silicone sheet mold having a thickness of 0.5 mm on a PET film, placing the composition in the mold, and sandwiching the composition between PET films. Next, an LED lamp is used to irradiate the 0.5 mm-thick composition with ultraviolet light having a wavelength of 395 nm at an irradiation dose of 1,500 mJ / cm. ２ (100mW / cm ２ and irradiation time: 15 seconds) to obtain a cured product of the composition. Hereinafter, the term "cured product of the composition" in the measurement of other physical properties will also be the same as the cured product of the composition described in this paragraph, unless otherwise specified.

[0019] From the viewpoint of more efficiently extracting light from an organic EL display element or an LED element, the refractive index of a cured product of the composition of this embodiment at 25°C and 589 nm is preferably from 1.45 to 1.70, more preferably from 1.46 to 1.65, even more preferably from 1.47 to 1.60, and still more preferably from 1.48 to 1.57. The refractive index at 25°C and 589 nm means a value measured with an Abbe refractometer.

[0020] The composition of the present embodiment may be liquid at 25°C or solid at 25°C, but is preferably liquid at 25°C.

[0021] From the viewpoint of further improving the balance between the coatability of the composition to a substrate or the like and the dischargeability during coating, the viscosity of the composition of the present embodiment according to Method 1 is preferably from 1 mPa·s to 700 mPa·s, more preferably from 3 mPa·s to 500 mPa·s, even more preferably from 5 mPa·s to 300 mPa·s, still more preferably from 7 mPa·s to 100 mPa·s, and even more preferably from 10 mPa·s to 50 mPa·s.

[0022] <Method 1> Apparatus: Cone-plate viscometer Temperature: 25°C Cone: Radius 24 mm, angle 0.8° Rotation speed: 250 rpm Sample volume: 0.5 mL Atmosphere: Air

[0023] The cure shrinkage of the composition of the present embodiment, calculated by <Method 2>, is preferably 1.0% or more and 15.0% or less, more preferably 2.0% or more and 12.0% or less, and even more preferably 3.0% or more and 10.0% or less.

[0024] <Method 2> A pycnometer is filled with the composition, and the liquid specific gravity is calculated by measuring the mass in the air and the mass in pure water. The specific gravity of the cured product is calculated by measuring the mass of a cured product made of the composition, 25 mm wide, 25 mm long, and 0.5 mm thick, in the air and in pure water, and the cure shrinkage is calculated using the formula: cure shrinkage = ((cured product specific gravity - liquid specific gravity) / cured product specific gravity) x 100 (%).

[0025] The static surface tension of the composition of this embodiment, as measured by the pendant drop method, is preferably 50 mN / m or less, more preferably 45 mN / m or less, and even more preferably 40 mN / m or less, from the viewpoint of further improving the coatability of the composition to a substrate or the like. The lower limit is not particularly limited, but may be, for example, 10 mN / m or more, 20 mN / m or more, or 25 mN / m or more. The static surface tension of the composition of this embodiment, as measured by the pendant drop method, is preferably 10 mN / m or more and 50 mN / m or less, more preferably 20 mN / m or more and 45 mN / m or less, and even more preferably 25 mN / m or more and 40 mN / m or less, from the viewpoint of further improving the coatability of the composition to a substrate or the like. The pendant drop method is a method in which a liquid is extruded from the tip of a tube and the surface tension is calculated from the shape of the pendant drop that hangs down.

[0026] Each of the components of the composition of this embodiment will be specifically described below.

[0027] <Polymerizable Compound (A)> The composition of this embodiment contains a polymerizable compound (A). The polymerizable compound (A) is a compound having a polymerizable group. The polymerizable group is not particularly limited, and examples thereof include a cationically polymerizable group, a radically polymerizable group, and an anionically polymerizable group. The polymerizable compound (A) may be a compound containing one polymerizable group in the molecule, or a compound containing two or more polymerizable groups in the molecule. However, from the viewpoint of further improving the heat resistance of a cured product made of the composition, the polymerizable compound (A) is preferably a compound containing two or more polymerizable groups in the molecule, and more preferably a compound containing two polymerizable groups in the molecule.

[0028] The polymerizable compound (A) preferably contains a bromine atom from the viewpoint of further improving the coatability of the composition onto a substrate, etc. Here, the polymerizable compound (A) containing a bromine atom means that the polymerizable compound (A) contains a bromine atom.

[0029] The polymerizable compound (A) preferably contains a cationically polymerizable compound.

[0030] The cationically polymerizable compound is not particularly limited and includes, for example, at least one selected from the group consisting of epoxy compounds and oxetane compounds, and preferably includes an epoxy compound. The epoxy compound may be a compound containing one epoxy group in the molecule, or may be a compound containing two or more epoxy groups in the molecule, but from the viewpoint of further improving the heat resistance of a cured product made from the composition, it is preferably a compound containing two or more epoxy groups in the molecule, and more preferably a compound containing two epoxy groups in the molecule.

[0031] The epoxy compound includes at least one selected from the group consisting of, for example, an alicyclic epoxy compound, an epoxy compound containing an aromatic group in the molecule, and a compound containing a glycidyl ether group, and preferably includes an alicyclic epoxy compound.

[0032] The alicyclic epoxy compound is a compound containing an epoxy group and an alicyclic group in the molecule. The alicyclic epoxy compound may be a compound containing one epoxy group in the molecule or a compound containing two or more epoxy groups in the molecule, but is preferably a compound containing two or more epoxy groups in the molecule, and more preferably a compound containing two epoxy groups in the molecule.

[0033] Examples of the alicyclic epoxy compound include a compound obtained by epoxidizing a compound having a cycloalkene ring or a derivative thereof, and a compound obtained by hydrogenating a compound having an epoxy group and an aromatic ring or a derivative thereof.

[0034] The compound or its derivative obtained by epoxidizing a compound having a cycloalkene ring includes, for example, at least one selected from the group consisting of 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxycyclohexylalkyl(meth)acrylate (e.g., 3,4-epoxycyclohexylmethyl(meth)acrylate), and (3,3',4,4'-diepoxy)bicyclohexyl.

[0035] The compound obtained by hydrogenating a compound having an epoxy group and an aromatic ring or a derivative thereof includes, for example, at least one selected from the group consisting of hydrogenated bisphenol A epoxy resins and hydrogenated bisphenol F epoxy resins.

[0036] The alicyclic epoxy compound is preferably a compound having a 1,2-epoxycyclohexane structure. The compound having a 1,2-epoxycyclohexane structure is preferably a compound represented by formula (A1-1).

[0037]

[0038] In formula (A1-1), X represents a single bond or a linking group (a divalent group having one or more atoms), and is preferably a linking group.

[0039] When X is a single bond, the compound represented by formula (A1-1) is (3,3',4,4'-diepoxy)bicyclohexyl.

[0040] The linking group may be, for example, a divalent hydrocarbon group, a carbonyl group, an ether bond, an ester bond, a carbonate group, an amide bond, or a group in which a plurality of these are linked together, preferably a group having an ester bond, and more preferably a group in which an ester bond and a divalent hydrocarbon group are linked together. The divalent hydrocarbon group is preferably an alkanediyl group, more preferably an alkanediyl group having from 1 to 3 carbon atoms. When X is a group having an ester bond as a linking group, an example of the compound represented by formula (A1-1) is 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate.

[0041] The compound represented by formula (A1-1) preferably includes at least one selected from the group consisting of 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and (3,3',4,4'-diepoxy)bicyclohexyl, and more preferably includes 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate.

[0042] The epoxy compound containing an aromatic group in the molecule may be a compound containing one epoxy group in the molecule, or a compound containing two or more epoxy groups in the molecule, but is preferably a compound containing two or more epoxy groups in the molecule, and more preferably a compound containing two epoxy groups in the molecule. The epoxy compound containing an aromatic group in the molecule may be a compound not containing an alicyclic group.

[0043] The epoxy compound containing an aromatic group in the molecule can be any of a monomer, an oligomer, or a polymer. The epoxy compound containing an aromatic group in the molecule preferably includes at least one selected from the group consisting of a compound having a bisphenol structure (e.g., a bisphenol A structure, a bisphenol F structure, a bisphenol S structure, etc.) and a bromine atom-containing aromatic epoxy compound, more preferably includes at least one selected from the group consisting of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a halophenyl glycidyl ether, and even more preferably includes at least one selected from the group consisting of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and a dibromophenyl glycidyl ether.

[0044] The compound containing a glycidyl ether group may be a compound containing one epoxy group in the molecule, or a compound containing two or more epoxy groups in the molecule, but is preferably a compound containing two or more epoxy groups in the molecule, and more preferably a compound containing two epoxy groups in the molecule. The compound containing a glycidyl ether group may be a compound that does not contain an alicyclic group or an aromatic ring.

[0045] The compound containing a glycidyl ether group preferably contains a diglycidyl ether compound. From the viewpoint of further improving the coatability of the composition to a substrate or the like, the diglycidyl ether compound preferably contains at least one selected from the group consisting of diglycidyl ethers of alkylene glycols such as diglycidyl ether of ethylene glycol, diglycidyl ether of propylene glycol, diglycidyl ether of 1,6-hexanediol, and diglycidyl ether of neopentyl glycol; polyglycidyl ethers of polyhydric alcohols such as di- or triglycidyl ethers of glycerin or an alkylene oxide adduct thereof; and diglycidyl ethers of polyalkylene glycols such as diglycidyl ethers of polyethylene glycol or an alkylene oxide adduct thereof, and diglycidyl ethers of polypropylene glycol or an alkylene oxide adduct thereof, and more preferably contains a diglycidyl ether of an alkylene glycol. The diglycidyl ether of alkylene glycol preferably includes at least one selected from the group consisting of diglycidyl ether of ethylene glycol, diglycidyl ether of propylene glycol, diglycidyl ether of 1,6-hexanediol, and diglycidyl ether of neopentyl glycol, and more preferably includes one or two selected from the group consisting of diglycidyl ether of 1,6-hexanediol and diglycidyl ether of neopentyl glycol.

[0046] The content of the cationically polymerizable compound in the composition of the present embodiment may be, for example, 50 parts by mass or more and 100 parts by mass or less, 70 parts by mass or more and 100 parts by mass or less, or 90 parts by mass or more and 100 parts by mass or less, when the content of the polymerizable compound (A) in the composition of the present embodiment is taken as 100 parts by mass.

[0047] The content of the epoxy compound in the composition of the present embodiment may be, for example, 50 parts by mass or more and 100 parts by mass or less, 70 parts by mass or more and 100 parts by mass or less, or 90 parts by mass or more and 100 parts by mass or less, when the content of the polymerizable compound (A) in the composition of the present embodiment is taken as 100 parts by mass.

[0048] The content of the alicyclic epoxy compound in the composition of the present embodiment may be, for example, 5 parts by mass or more and 100 parts by mass or less, 10 parts by mass or more and 80 parts by mass or less, or 15 parts by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the polymerizable compound (A) in the composition of the present embodiment.

[0049] The content of the aromatic epoxy compound in the composition of the present embodiment may be, for example, 5 parts by mass or more and 50 parts by mass or less, 10 parts by mass or more and 20 parts by mass or less, or 15 parts by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the polymerizable compound (A) in the composition of the present embodiment.

[0050] The content of the compound containing a glycidyl ether group in the composition of the present embodiment may be, for example, 5 parts by mass or more and 95 parts by mass or less, 10 parts by mass or more and 90 parts by mass or less, or 20 parts by mass or more and 80 parts by mass or less, relative to 100 parts by mass of the polymerizable compound (A) in the composition of the present embodiment.

[0051] The polymerizable compound (A) preferably includes a radically polymerizable compound.

[0052] The radical polymerizable compound is not particularly limited, but preferably contains a (meth)acrylate.

[0053] The (meth)acrylate may contain a monofunctional (meth)acrylate or a polyfunctional (meth)acrylate, but preferably contains a polyfunctional (meth)acrylate from the viewpoint of further improving the heat resistance of a cured product of the composition. Here, the polyfunctional (meth)acrylate means a compound containing two or more (meth)acryloyl groups in the molecule.

[0054] The polyfunctional (meth)acrylate is preferably a compound containing 2 to 6 (meth)acryloyl groups, more preferably a compound containing 2 to 4 (meth)acryloyl groups, and even more preferably a compound containing 2 (meth)acryloyl groups.

[0055] The (meth)acrylate includes, for example, at least one selected from the group consisting of (meth)acrylates containing an alicyclic structure in the molecule, (meth)acrylates containing an aromatic group in the molecule, and acyclic (meth)acrylates, and preferably includes a (meth)acrylate containing an alicyclic structure in the molecule.

[0056] The (meth)acrylate containing an alicyclic structure in the molecule is a compound containing a (meth)acryloyl group and an alicyclic group. The alicyclic group includes at least one selected from the group consisting of a group having a dicyclopentadiene skeleton such as a dicyclopentanyl group or a dicyclopentenyl group, a cyclohexyl group, an isobornyl group, a cyclodecatriene group, a norbornyl group, an adamantyl group, a tricyclodecane group, and the like, and preferably includes a group having one or two selected from the group consisting of a dicyclopentadiene skeleton and a tricyclodecane skeleton.

[0057] The (meth)acrylate containing an alicyclic structure in the molecule includes at least one selected from the group consisting of, for example, tricyclodecane dimethanol di(meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, and the like, and preferably includes tricyclodecane dimethanol di(meth)acrylate.

[0058] The (meth)acrylate containing an alicyclic structure in the molecule may be a monofunctional (meth)acrylate or a polyfunctional (meth)acrylate, but is preferably a polyfunctional (meth)acrylate, and more preferably a bifunctional (meth)acrylate.

[0059] The (meth)acrylate containing an aromatic group in the molecule includes, for example, at least one selected from the group consisting of ethoxylated bisphenol A di(meth)acrylate, ethoxylated o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, etc., and preferably includes ethoxylated bisphenol A di(meth)acrylate.

[0060] The (meth)acrylate containing an aromatic group in the molecule may be a monofunctional (meth)acrylate or a polyfunctional (meth)acrylate, preferably a polyfunctional (meth)acrylate, and more preferably a bifunctional (meth)acrylate.

[0061] The acyclic (meth)acrylate includes at least one selected from the group consisting of, for example, 1,6-hexadiol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, methoxydiethylene glycol (meth)acrylate, and the like, and preferably includes 1,12-dodecanediol di(meth)acrylate.

[0062] The acyclic (meth)acrylate may be a monofunctional (meth)acrylate or a polyfunctional (meth)acrylate, but is preferably a polyfunctional (meth)acrylate, and more preferably a difunctional (meth)acrylate.

[0063] The content of the radical polymerizable compound in the composition of this embodiment may be, for example, 50 parts by mass or more and 100 parts by mass or less, 70 parts by mass or more and 100 parts by mass or less, or 90 parts by mass or more and 100 parts by mass or less, when the content of the polymerizable compound (A) in the composition of this embodiment is taken as 100 parts by mass.

[0064] The content of the (meth)acrylate in the composition of the present embodiment may be, for example, 50 parts by mass or more and 100 parts by mass or less, 70 parts by mass or more and 100 parts by mass or less, or 90 parts by mass or more and 100 parts by mass or less, relative to 100 parts by mass of the polymerizable compound (A) in the composition of the present embodiment.

[0065] The content of the polyfunctional (meth)acrylate in the composition of the present embodiment may be, for example, 50 parts by mass or more and 100 parts by mass or less, 70 parts by mass or more and 100 parts by mass or less, or 90 parts by mass or more and 100 parts by mass or less, when the content of the polymerizable compound (A) in the composition of the present embodiment is taken as 100 parts by mass.

[0066] The content of the (meth)acrylate having an alicyclic structure in the molecule in the composition of the present embodiment may be, for example, 5 parts by mass or more and 100 parts by mass or less, 10 parts by mass or more and 80 parts by mass or less, or 20 parts by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the polymerizable compound (A) in the composition of the present embodiment.

[0067] The content of the (meth)acrylate containing an aromatic group in the molecule in the composition of the present embodiment may be, for example, 1 part by mass or more and 50 parts by mass or less, or 3 parts by mass or more and 30 parts by mass or less, relative to 100 parts by mass of the polymerizable compound (A) in the composition of the present embodiment.

[0068] The amount of the acyclic (meth)acrylate in the composition of the present embodiment may be, for example, 50 parts by mass or more and 90 parts by mass or less, or 60 parts by mass or more and 80 parts by mass or less, relative to 100 parts by mass of the polymerizable compound (A) in the composition of the present embodiment.

[0069] The polymerizable compound (A) may be a single polymerizable compound, or two or more polymerizable compounds may be used in combination.

[0070] <Polymerization initiator (B)> The composition of the present embodiment contains a polymerization initiator (B). The polymerization initiator (B) is not particularly limited as long as it can initiate the polymerization reaction of the polymerizable compound (A). The polymerization initiator (B) may contain a photopolymerization initiator that can be activated by light to initiate the polymerization reaction of the polymerizable compound (A), or may contain a thermal polymerization initiator that can be activated by heat to initiate the polymerization reaction of the polymerizable compound (A).

[0071] In the composition of the present embodiment, the polymerizable compound (A) preferably includes a cationically polymerizable compound, and the polymerization initiator (B) preferably includes a cationic polymerization initiator.

[0072] The cationic polymerization initiator includes, for example, at least one selected from the group consisting of a photocationic polymerization initiator and a thermal cationic polymerization initiator, and more preferably includes a photocationic polymerization initiator.

[0073] Examples of the photocationic polymerization initiator include arylsulfonium salt derivatives (e.g., Cyracure UVI-6990 and Cyracure UVI-6974 manufactured by The Dow Chemical Company, Adeka Optomer SP-150, Adeka Optomer SP-152, Adeka Optomer SP-170, and Adeka Optomer SP-172 manufactured by ADEKA Corporation, CPI-100P, CPI-101A, CPI-200K, CPI-210S, CPI-310FG, and LW-S1 manufactured by San-Apro Co., Ltd., and Double Bond Co., Ltd.). The initiator contains at least one selected from the group consisting of an acid generator such as an aryl sulfonium salt derivative (e.g., CibaCure-1190 manufactured by Ciba Specialty Chemicals, etc.), an aryl iodonium salt derivative (e.g., Irgacure 250 manufactured by Ciba Specialty Chemicals, RP-2074 manufactured by Rhodia Japan, etc.), an allene-ion complex derivative, a diazonium salt derivative, a triazine initiator, and other halides, and the like, and preferably contains an aryl sulfonium salt derivative, and more preferably contains a triaryl sulfonium salt derivative.

[0074] Examples of the thermal cationic polymerization initiator include onium salt compounds such as quaternary ammonium salts, phosphonium salts, and sulfonium salts. Commercially available thermal cationic polymerization initiators include Adekaopton CP-66 and Adekaopton CP-77 (manufactured by ADEKA Corporation), San-Aid SI-60L, San-Aid SI-80L, and San-Aid SI-100L (manufactured by Sanshin Chemical Industry Co., Ltd.), and the CI series (manufactured by Nippon Soda Co., Ltd.).

[0075] In the composition of the present embodiment, the polymerizable compound (A) preferably includes a radical polymerizable compound, and the polymerization initiator (B) preferably includes a radical polymerization initiator.

[0076] The radical polymerization initiator includes, for example, at least one selected from the group consisting of a photoradical polymerization initiator and a thermal radical polymerization initiator, and preferably includes a photoradical polymerization initiator.

[0077] The photoradical polymerization initiator includes at least one selected from the group consisting of, for example, benzophenone and derivatives thereof, benzil and derivatives thereof, enthraquinone and derivatives thereof, acetophenone derivatives, thioxanthone and derivatives thereof, camphorquinone derivatives, α-aminoalkylphenone derivatives, and acylphosphine oxide derivatives, and preferably includes an acylphosphine oxide derivative.

[0078] The acylphosphine oxide derivative includes at least one selected from the group consisting of, for example, benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoyldiethoxyphosphine oxide, 2,4,6-trimethylbenzoyldimethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and ethyl-2,4,6-trimethylbenzoylphenylphosphinate, and preferably includes at least one selected from the group consisting of 2,4,6-trimethylbenzoyldiphenylphosphine oxide and ethyl-2,4,6-trimethylbenzoylphenylphosphinate.

[0079] The content of the polymerization initiator (B) in the composition of the present embodiment is preferably 0.01 parts by mass or more and 10 parts by mass or less, more preferably 0.05 parts by mass or more and 8 parts by mass or less, and even more preferably 0.1 parts by mass or more and 6 parts by mass or less, from the viewpoint of further improving the curability of the composition and further improving the transparency of a cured product made of the composition, when the content of the polymerizable compound (A) in the composition of the present embodiment is taken as 100 parts by mass.

[0080] The content of the cationic polymerization initiator in the composition of this embodiment is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the polymerizable compound (A) in the composition, from the viewpoint of further improving the curability of the composition, and is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 1 part by mass or less, relative to 100 parts by mass of the polymerizable compound (A) in the composition, from the viewpoint of further improving the curability of the composition and the transparency of the cured product of the composition. The content of the cationic polymerization initiator in the composition of this embodiment is preferably 0.01 parts by mass or more and 5 parts by mass or less, more preferably 0.05 parts by mass or more and 3 parts by mass or less, and even more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the polymerizable compound (A) in the composition, from the viewpoint of further improving the curability of the composition and the transparency of the cured product of the composition.

[0081] The content of the radical polymerization initiator in the composition of this embodiment, relative to 100 parts by mass of the polymerizable compound (A) in the composition of this embodiment, is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, from the viewpoint of further improving the curability of the composition, and is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 6 parts by mass or less, from the viewpoint of further improving the transparency of a cured product made from the composition. The content of the radical polymerization initiator in the composition of this embodiment, relative to 100 parts by mass of the polymerizable compound (A) in the composition of this embodiment, is preferably 0.5 parts by mass or more and 10 parts by mass or less, more preferably 1 part by mass or more and 8 parts by mass or less, and even more preferably 2 parts by mass or more and 6 parts by mass or less, from the viewpoint of further improving the curability of the composition and the transparency of a cured product made from the composition.

[0082] The polymerization initiator (B) may be a single polymerization initiator, or two or more polymerization initiators may be used in combination.

[0083] <Cure Retarder (C)> The composition of the present embodiment preferably further contains a cure retarder (C) from the viewpoint of extending the usable life of the composition.

[0084] The cure retarder (C) is not particularly limited, but preferably includes at least one selected from the group consisting of phosphoric acid-based cure retarders, ether-based cure retarders, thioether-based cure retarders, metal complex-based cure retarders, and nitroxy radical-based cure retarders, and more preferably includes at least one selected from the group consisting of phosphoric acid-based cure retarders and ether-based cure retarders.

[0085] The phosphoric acid-based set retarder is a set retarder selected from the group consisting of phosphate esters and phosphites. The phosphoric acid-based set retarder preferably includes a phosphate ester.

[0086] Examples of phosphate esters include diethylbenzyl phosphate, trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, tris(butoxyethyl) phosphate, tris(2-ethylhexyl) phosphate, (RO) ３ P═O (R is a lauryl group, a cetyl group, a stearyl group, or an oleyl group), tris(2-chloroethyl)phosphate, tris(2-dichloropropyl)phosphate, triphenyl phosphate, butyl pyrophosphate, tricresyl phosphate, trixylenyl phosphate, octyl diphenyl phosphate, cresyl diphenyl phosphate, xylenyl diphosphate, monobutyl phosphate, dibutyl phosphate, di-2-ethylhexyl phosphate, monoisodecyl phosphate, ammonium ethyl acid phosphate, 2-ethylhexyl acid phosphate salt, and the like, and preferably includes at least one selected from the group consisting of triethyl phosphate, tri-n-butyl phosphate, tris(butoxyethyl)phosphate, tris(2-ethylhexyl)phosphate, and (RO) ３ The surfactant contains at least one selected from the group consisting of P═O (R is a lauryl group, a cetyl group, a stearyl group, or an oleyl group), and more preferably contains tris(2-ethylhexyl) phosphate.

[0087] The phosphite ester includes, for example, at least one selected from the group consisting of trimethyl phosphite, triethyl phosphite, tri-n-butyl phosphite, tris(2-ethylhexyl) phosphite, triisooctyl phosphite, tridecyl phosphite, triisodecyl phosphite, tris(tridecyl) phosphite, trioleyl phosphite, tristearyl phosphite, triphenyl phosphite, and tris(nonylphenyl) phosphite.

[0088] The ether-based cure retarder is a cure retarder having an ether bond. The ether-based cure retarder may contain a chain ether or a cyclic ether. From the viewpoint of appropriate reactivity with cations, the ether-based cure retarder preferably contains a cyclic ether, more preferably contains a crown ether, and even more preferably contains 18-crown ether-6.

[0089] The content of the curing retarder (C) in the composition of this embodiment, when the content of the polymerizable compound (A) in the composition of this embodiment is taken as 100 parts by mass, is preferably 0.10 parts by mass or more, more preferably 0.20 parts by mass or more, and even more preferably 0.30 parts by mass or more, from the viewpoint of extending the usable life of the composition, and is preferably 10.0 parts by mass or less, more preferably 5.0 parts by mass or less, and even more preferably 2.0 parts by mass or less, from the viewpoint of further improving the moisture resistance of a cured product made from the composition. The content of the curing retarder (C) in the composition of this embodiment, when the content of the polymerizable compound (A) in the composition of this embodiment is taken as 100 parts by mass, is preferably 0.10 parts by mass or more and 10.0 parts by mass or less, more preferably 0.20 parts by mass or more and 5.0 parts by mass or less, and even more preferably 0.30 parts by mass or more and 2.0 parts by mass or less, from the viewpoint of further extending the usable life of the composition and further improving the moisture resistance of a cured product made from the composition.

[0090] The curing retarder (C) preferably contains a phosphoric acid-based curing retarder and an ether-based curing retarder. The mass ratio of the content of the phosphoric acid-based curing retarder in the curing retarder (C) to the ether-based curing retarder in the curing retarder (C) is preferably 0.001 or more, more preferably 0.003 or more, and even more preferably 0.005 or more, from the viewpoint of further improving the coatability of the composition to substrates, etc., and from the viewpoint of further improving the moisture resistance of the cured product made from the composition, it is preferably 2.0 or less, more preferably 1.0 or less, and even more preferably 0.5 or less. The mass ratio of the content of the phosphoric acid-based curing retarder in the curing retarder (C) to the ether-based curing retarder in the curing retarder (C) is preferably 0.001 or more and 2.0 or less, more preferably 0.003 or more and 1.0 or less, and even more preferably 0.005 or more and 0.5 or less, from the viewpoint of further improving the coatability of the composition to substrates, etc., and further improving the moisture resistance of the cured product made from the composition.

[0091] The curing retarder (C) may be a single curing retarder or a combination of two or more curing retarders.

[0092] <Leveling Agent> The composition of the present embodiment may further contain a leveling agent from the viewpoint of further improving the coatability of the composition to a substrate, etc. Examples of the leveling agent include a (meth)acrylic leveling agent and a silicone leveling agent, and among these, a (meth)acrylic leveling agent is preferred.

[0093] The content of the leveling agent in the composition of the present embodiment may be, for example, 0.005 parts by mass or more and 1 part by mass or less, or 0.01 parts by mass or more and 0.1 parts by mass or less, when the content of the polymerizable compound (A) in the composition of the present embodiment is taken as 100 parts by mass.

[0094] The leveling agent may be a single leveling agent, or two or more leveling agents may be used in combination.

[0095] <Other Components> The composition of the present embodiment may further contain other components. Examples of the other components include a photosensitizer, a silane coupling agent, an antioxidant, an inorganic filler, resin particles, a metal deactivator, a filler, a stabilizer, a neutralizing agent, a lubricant, and an antibacterial agent. The content of the other components is an appropriate amount.

[0096] The total content of the polymerizable compound (A) and the polymerization initiator (B) in the composition of the present embodiment is preferably 60% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 80% by mass or more and 100% by mass or less, even more preferably 90% by mass or more and 100% by mass or less, and still more preferably 95% by mass or more and 100% by mass or less, when the entire composition of the present embodiment is taken as 100% by mass.

[0097] [Use of Composition] The composition of the present embodiment is preferably a composition that can be used to encapsulate a light-emitting diode element, and more preferably a composition that can be used to encapsulate a micro LED.

[0098] The composition of the present embodiment is preferably a composition that can be used for inkjet coating or dispenser coating, and more preferably a composition that can be used for inkjet coating.

[0099] [Method for Producing Composition] The method for producing the composition of the present embodiment includes, for example, a method of thoroughly mixing the components. The method for mixing the components is not particularly limited, but examples thereof include a stirring method that utilizes the stirring force associated with the rotation of a propeller, and a method that utilizes a conventional disperser such as a planetary stirrer that revolves around its axis.

[0100] [Cured Product] The cured product of this embodiment includes a cured product made of the composition of this embodiment. The cured product of this embodiment is preferably a cured product that can be used as a cured sealing layer of a display device.

[0101] The method for obtaining the cured product of the present embodiment is not particularly limited, and examples thereof include a method for obtaining the cured product by irradiating the composition of the present embodiment with light. From the viewpoint of further accelerating the curing reaction, the composition after light irradiation may be heated.

[0102] The light source for irradiating the composition of the present embodiment with light is not particularly limited, and examples thereof include a halogen lamp, a metal halide lamp, a high-power metal halide lamp (containing indium or the like), a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a xenon excimer lamp, a xenon flash lamp, and an LED.

[0103] The above light sources have different radiation wavelengths and energy distributions. Therefore, the light source can be appropriately selected depending on the reaction wavelength of the photopolymerization initiator. Natural light (sunlight) can also be used as a light source to initiate the reaction of the sealant.

[0104] The irradiation method may be direct irradiation, focused irradiation using a reflecting mirror or the like, or focused irradiation using a fiber or the like. Irradiation may also be carried out using a low wavelength cut filter, a heat ray cut filter, a cold mirror, or the like.

[0105] The amount of light irradiation is not particularly limited and may be adjusted appropriately depending on the thickness of the coating film of the composition, etc. The amount of light irradiation is, for example, 50 mJ / cm ２ More than 20000mJ / cm ２ may be less than or equal to 100 mJ / cm ２ More than 10000mJ / cm ２ The following is the result.

[0106] [Display Device] The display device of the present embodiment includes a light-emitting diode element, a substrate, and a cured sealing layer containing the cured body of the present embodiment between the light-emitting diode element and the substrate.

[0107] The light-emitting diode element includes, for example, an organic electroluminescence display element or a micro LED, and preferably includes a micro LED. The light-emitting diode element may also be in the form of a substrate with light-emitting diode elements (TFT substrate), which is a textured substrate.

[0108] The substrate is not particularly limited and includes, for example, at least one selected from the group consisting of a color filter, a glass substrate, a silicon substrate, a plastic substrate, etc., and preferably includes at least one selected from the group consisting of a color filter and a glass substrate.

[0109] The cured sealing layer may be made of the cured product of this embodiment, or may contain the cured product of this embodiment and other constituent materials, such as inorganic layers of silicon nitride films, silicon oxide films, silicon nitride oxide, etc., and inorganic fillers such as silica, mica, kaolin, talc, and aluminum oxide.

[0110] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0111] The present embodiment will be described in detail below based on examples and comparative examples. However, the present embodiment is not limited to the descriptions of these examples. Unless otherwise specified, the examples were tested at 23°C and a relative humidity of 50% by mass.

[0112] [Examples 1 to 12 and Comparative Examples 1 to 3] The components shown in Tables 1 and 2 were mixed in the composition ratios (parts by mass) shown in Tables 1 and 2 to prepare the compositions of Examples 1 to 12 and Comparative Examples 1 to 3, respectively.

[0113] The components shown in Tables 1 and 2 have the following meanings:

[0114] <Cationically polymerizable compounds> (A-1) Bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: jER828, containing two epoxy groups in the molecule) (A-2) Bisphenol F type epoxy resin (manufactured by Mitsubishi Chemical Corporation, product name: jER806, containing two epoxy groups in the molecule) (A-3) 3',4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (manufactured by Daicel Corporation, product name: Celloxide 2021P) (A-4) (3,3',4,4'-diepoxy)bicyclohexyl (manufactured by Daicel Corporation, product name: Celloxide 8010) (A-5) Dibromophenyl glycidyl ether (manufactured by Nippon Kayaku Co., Ltd., product name: BR-250H) (A-6) 1,6-Hexanediol diglycidyl ether (manufactured by ADEKA Corporation, product name: ADEKA GLYCILOR ED-503G) (A-7) Neopentyl glycol diglycidyl ether (manufactured by ADEKA Corporation, product name: ADEKA GLYCILOR ED-523L) (A-8) 2-Ethylhexyl oxetane (manufactured by Toagosei Co., Ltd., product name: OXT-212)

[0115] <Radical Polymerizable Compounds> (B-1) 1,12-dodecanediol dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: DDD) (B-2) Ethoxylated bisphenol A dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: NK Ester BPE-200) (B-3) Tricyclodecane dimethanol diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: NK Ester A-DCP) (B-4) Ethoxylated o-phenylphenol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: NK Ester A-LEN-10)

[0116] <Cationic Polymerization Initiator> (C-1) Triarylsulfonium Salt Hexafluoroantimonate (manufactured by ADEKA Corporation, product name: ADEKAOPTOMER SP-170) (C-2) Triarylsulfonium Salt-Tetrakispentafluorophenyl Gallate (manufactured by San-Apro Co., Ltd., product name: CPI-310FG)

[0117] <Radical Polymerization Initiator> (D-1) 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by IGM RESINS, product name: Omnirad TPO) (D-2) Ethyl 2,4,6-trimethylbenzoylphenylphosphinate (manufactured by IGM RESINS, product name: Omnirad TPO-L)

[0118] <Cure retarder> (E-1) 18-crown ether-6 (manufactured by Tokyo Chemical Industry Co., Ltd., product name: Crown Ether O-18) (E-2) Tris(2-ethylhexyl)phosphate (manufactured by Daihachi Chemical Industry Co., Ltd., product name: TOP)

[0119] <Leveling Agent> (F-1) Acrylic leveling agent (manufactured by BYK, product name: BYK-356)

[0120] [Measurements and Evaluations] The compositions of the Examples and Comparative Examples were subjected to the following measurements and evaluations. The evaluation results are shown in Tables 1 and 2.

[0121] <Storage Modulus E' and Glass Transition Temperature> A silicone sheet mold having a length of 50 mm, a width of 7 mm, and a thickness of 0.5 mm was placed on a PET film (manufactured by Toray Industries, Inc., product name: Lumirror S10, thickness: 50 μm), and a composition was placed in the mold, followed by sandwiching the composition between PET films (manufactured by Toray Industries, Inc., product name: Lumirror S10, thickness: 50 μm). When the composition was a cationically polymerizable composition (Examples 1 to 9 and Comparative Examples 1 and 2), a 0.5 mm thick composition was irradiated with ultraviolet light having a wavelength of 365 nm at a dose of 1,500 mJ / cm using an LED lamp (manufactured by HOYA Corporation, product name: H64AH4). ２ (100mW / cm ２ After irradiating the composition at a temperature of 15 seconds (irradiation time: 15 seconds), the composition was heated at 80°C for 30 minutes to obtain a cured product of the composition having a thickness of 0.5 mm. When the composition was a radically polymerizable composition (Examples 10 to 12 and Comparative Example 3), the composition was irradiated to a thickness of 0.5 mm with ultraviolet light having a wavelength of 395 nm at a dose of 1500 mJ / cm using an LED lamp (manufactured by HOYA Corporation, product name: H-4MLH200). ２ (Irradiation intensity: 100mW / cm ２The cured composition was irradiated with light at a temperature of 10°C to 200°C, with a heating rate of 2°C / min, a sample length of 50 mm, a sample width of 7 mm, and a nitrogen atmosphere in tension mode. The storage modulus E' and tanδ versus temperature were measured for the resulting 0.5 mm-thick cured composition using a dynamic viscoelasticity measuring device (Seiko Instruments Inc., product name: DMS210). From the measurement results, the storage modulus E' at 80°C and 25°C was determined. The temperature at the peak top of tanδ was taken as the glass transition temperature. The peak top of tanδ was taken as the maximum value in the range where tanδ was 0.3 or greater. If tanδ was less than 0.3 in the range from 10°C to 200°C, the peak top of tanδ was considered to be greater than 200°C, and the glass transition temperature was considered to be greater than 200°C (<200).

[0122] <Refractive Index> A cured product of the composition having a thickness of 0.5 mm was obtained in the same manner as in the above <Storage Modulus E' and Glass Transition Temperature>. The refractive index of the cured product of the composition having a thickness of 0.5 mm was measured at 25°C and 589 nm using an Abbe Refractometer (Atago Co., Ltd., product name: DR-M2).

[0123] <Viscosity> The viscosity of the composition was measured under the following conditions: Apparatus: Cone-plate viscometer (manufactured by Eiko Seiki Co., Ltd., product name: HB DV3T) Temperature: 25°C Cone: radius 24 mm, angle 0.8° Rotation speed: 250 rpm Sample amount: 0.5 mL Atmosphere: air

[0124] <Curing Shrinkage> A pycnometer was filled with the composition, and the liquid specific gravity was calculated by measuring the mass in air and in pure water. A cured product of the composition with a thickness of 0.5 mm was obtained in the same manner as in <Storage Modulus E' and Glass Transition Temperature> above, except that the silicone sheet mold was 25 mm long and 25 mm wide. A cured product of the composition with a width of 25 mm, a length of 25 mm, and a thickness of 0.5 mm was used as a measurement sample. Next, the mass of the measurement sample in air and in pure water was measured to calculate the specific gravity of the cured product. The curing shrinkage was calculated using the formula: Curing shrinkage = ((specific gravity of cured product - liquid specific gravity) / specific gravity of cured product) x 100 (%).

[0125] <Static Surface Tension> The static surface tension of the composition was measured in an atmosphere of 23° C. by the pendant drop method using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., product name: DM500).

[0126] <LED Reliability Test> Each LED light-emitting device was prepared, each of which was formed of an LED chip as a light source, a first lead frame on which the light source was mounted, a second lead frame, the compositions of Examples 1 to 12 and Comparative Examples 1 to 3 covering the light source, bonding wires electrically connecting the light source and the second lead frame, and a synthetic resin cap covering these. An LED chip emitting light with a wavelength of 300 nm or more and 500 nm or less was used as the light source. When the composition was a cationically polymerizable composition (Examples 1 to 9 and Comparative Examples 1 and 2), an LED lamp (manufactured by HOYA Corporation, product name: H64AH4) was used to irradiate the device with ultraviolet light having a wavelength of 365 nm at a dose of 1,500 mJ / cm. ２ (100mW / cm ２ The LED chip was sealed by irradiating the composition with ultraviolet light having a wavelength of 395 nm at a dose of 1500 mJ / cm using an LED lamp (manufactured by HOYA Corporation, product name: H-4MLH200) after irradiating the composition with ultraviolet light for 15 seconds. ２ (Irradiation intensity: 100mW / cm ２The LED light-emitting device after sealing was subjected to a current emission test at 60°C and 90% RH for 500 hours, and the device in which the LED chip did not light out was rated as A (good), and the device in which the LED chip light out was rated as B (bad).

[0127]

[0128]

[0129] As can be seen from Tables 1 and 2, the compositions of the examples all showed good results in the LED reliability test. That is, it can be seen that the composition of the present embodiment can improve the reliability of display devices.

[0130] This application claims priority based on Japanese Patent Application No. 2024-022592, filed February 19, 2024, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A composition comprising a polymerizable compound (A) and a polymerization initiator (B), wherein a cured product of the composition has a storage modulus E' of 0.5 GPa or more and 5.0 GPa or less at 80°C when measured using a dynamic viscoelasticity measuring device at a frequency of 1 Hz, in a temperature range of 10°C to 200°C, at a heating rate of 2°C / min in tensile mode.

2. The composition according to claim 1, wherein a cured product of the composition has a storage modulus E' of 1.0 GPa or more and 10.0 GPa or less at 25°C when measured using a dynamic viscoelasticity measuring device at a frequency of 1 Hz, at a temperature range of 10°C to 200°C, at a heating rate of 2°C / min in tensile mode.

3. The composition according to claim 1 or 2, wherein the polymerizable compound (A) comprises a cationically polymerizable compound, and the polymerization initiator (B) comprises a cationic polymerization initiator.

4. The composition of claim 3, wherein the cationically polymerizable compound comprises an epoxy compound.

5. The composition of claim 4, wherein the epoxy compound comprises a cycloaliphatic epoxy compound.

6. The composition according to claim 3, wherein the cationic polymerization initiator comprises at least one selected from the group consisting of a photocationic polymerization initiator and a thermal cationic polymerization initiator.

7. The composition according to claim 1 or 2, wherein the polymerizable compound (A) comprises a radical polymerizable compound, and the polymerization initiator (B) comprises a radical polymerization initiator.

8. The composition of claim 7, wherein the radically polymerizable compound comprises a (meth)acrylate.

9. The composition of claim 7, wherein the radical polymerization initiator comprises a photoradical polymerization initiator.

10. The composition of claim 1 or 2, further comprising a set retarder (C).

11. The composition according to claim 1 or 2, wherein a cured product of said composition has a glass transition temperature of 70°C or higher when measured using a dynamic viscoelasticity measuring device at a frequency of 1 Hz, a heating rate of 2°C / min, and in tensile mode.

12. The composition according to claim 1 or 2, wherein the refractive index of a cured product of said composition at 25°C and 589 nm is 1.45 or more and 1.70 or less.

13. The composition according to claim 1 or 2, which is liquid at 25°C.

14. The composition according to claim 1 or 2, wherein the viscosity of the composition is 1 mPa·s or more and 700 mPa·s or less, measured by the following <Method 1>. <Method 1> Apparatus: Cone-plate viscometer Temperature: 25°C Cone: Radius 24 mm, angle 0.8° Rotation speed: 250 rpm Sample amount: 0.5 mL Atmosphere: Air 15. The composition according to claim 1 or 2, which can be used for inkjet coating or dispenser coating.

16. The composition of claim 15, which can be used for ink jet application.

17. The composition according to claim 1 or 2, wherein the cure shrinkage calculated by the following <Method 2> is 1.0% or more and 15.0% or less. <Method 2> A pycnometer is filled with the composition, and the liquid specific gravity is calculated by measuring the mass in the air and the mass in pure water, and the specific gravity of the cured product is calculated by measuring the mass in the air and the mass in pure water of a cured product made of the composition having a width of 25 mm, a length of 25 mm, and a thickness of 0.5 mm, and the cure shrinkage is calculated using the formula: Cure shrinkage = ((specific gravity of cured product - liquid specific gravity) / specific gravity of cured product) x 100 (%).

18. The composition according to claim 1 or 2, which has a static surface tension of 50 mN / m or less as measured by the pendant drop method.

19. The composition according to claim 1 or 2, which can be used to encapsulate a micro LED.

20. A cured product comprising a cured product of the composition according to claim 1 or 2.

21. A display device comprising: a light-emitting diode element; a substrate; and a cured sealing layer between the light-emitting diode element and the substrate, the cured body according to claim 20.

22. The display device of claim 21, wherein the light emitting diode elements comprise micro LEDs.

Images