Curable composition, cured film, organic el element and method for manufacturing same

Abstract

The invention relates to a curable composition, a cured film, an organic EL element and a manufacturing method thereof. A curable composition containing a polymerizable compound and a polymerization initiator, the polymerizable compound in the curable composition comprising: a compound (A1) represented by formula (1): R1-X1-R2 (in formula (1), R1 and R2 independently represent a substituted or unsubstituted alicyclic oxacyclopropyl group; and X1 represents a divalent hydrocarbon group or a halogenated hydrocarbon group); a compound (A2) that is a polyfunctional polymerizable compound (excluding compound (A1)); and a compound (A3) that is a monofunctional polymerizable compound having one oxetanyl group in each molecule, the total amount of the compound (A1), the compound (A2), and the compound (A3) being 85 mass% or more with respect to the total amount of the polymerizable compounds.

Description

Technical Field

[0001] The present invention relates to a curable composition, a cured film, an organic EL element, and a method for manufacturing the same. Background Art

[0002] An organic electroluminescence element (organic EL (electroluminescence) element) is a light-emitting element having a laminated structure including an anode, an organic light-emitting layer, and a cathode. Organic EL elements have been widely put to practical use in various applications such as display devices and lighting devices.

[0003] The organic light-emitting layer included in an organic EL element is liable to deteriorate due to contact with moisture or oxygen. For example, there are concerns such as the formation of a region where light is not emitted locally due to moisture infiltrating into the element (hereinafter also referred to as a "dark spot") during long-term driving, or a reduction in light-emitting characteristics due to contact with moisture or oxygen. Therefore, conventionally, in an organic EL element, a sealing structure for sealing the organic light-emitting layer is provided, and the sealing structure is used to prevent the organic light-emitting layer from coming into contact with moisture or oxygen (for example, refer to Patent Documents 1 to 4).

[0004] In Patent Document 1, it is disclosed that a sealing structure covering an organic light-emitting layer is formed using a curable composition containing a polymerizable compound having two or three vinyl bonds bonded to a naphthalene ring and a polymerization initiator.

[0005] In Patent Document 2, it is disclosed that a sealant for an organic EL display element, in which, as a cationic polymerizable compound, a cycloolefin oxide type alicyclic epoxy compound and a compound having a biphenyl skeleton and an epoxy group or an oxetanyl group are included in a curable composition containing a cationic polymerizable compound and a cationic polymerization initiator.

[0006] In Patent Documents 3 and 4, it is disclosed that a sealing structure of an organic EL element is formed by curing a sealant composition containing an alicyclic epoxy compound, a monofunctional or polyfunctional oxetane compound, and an aliphatic epoxy compound as polymerizable compounds.

[0007] [Prior Art Documents]

[0008] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2020-26515

[0010] [Patent Document 2] International Publication No. 2021 / 010226

[0011] [Patent Document 3] Korean Published Patent No. 10-2022-0160362

[0012] [Patent Document 4] Korean Patent Publication No. 10-2023-0032669 Summary of the Invention

[0013] [Problems to be Solved by the Invention]

[0014] In the sealing structure of an organic EL element, a laminate of an inorganic sealing layer / an organic sealing layer / an inorganic sealing layer is generally used. When forming such a laminate, an inorganic sealing layer (e.g., a nitride film), an organic sealing layer, and an inorganic sealing layer are laminated in this order. In this case, if the glass transition temperature (Tg) of the organic sealing layer is low, strain is generated in the organic sealing layer when the inorganic sealing layer is formed on the organic sealing layer, which may cause cracks.

[0015] In addition, in an organic EL light-emitting device using a touch panel method, a touch sensor is disposed on a substrate. In the touch panel method, when the dielectric constant of the sealing structure (especially the organic sealing layer) is high, malfunction may occur when using the touch panel. Therefore, it is desired that the organic sealing layer of the sealing structure has a low dielectric constant, but there is a trade-off relationship between the low dielectric constant and the high Tg of the cured film. If the low dielectric constant of the cured film is to be achieved, the high Tg will result.

[0016] The present invention has been made in view of the above problems, and its main object is to provide a curable composition that can form a cured product having a low dielectric constant and a sufficiently high glass transition temperature.

[0017] [Technical Means for Solving the Problems]

[0018] The present invention provides the following curable composition, cured film, organic EL element, and method for manufacturing the same.

[0019] 〔1〕A curable composition containing a polymerizable compound and a polymerization initiator, in the curable composition, the polymerizable compound includes: compound (A1) represented by the following formula (1),

[0020] R 1 -X 1 -R 2 …(1)

[0021] (In formula (1), R 1 and R 2 are each independently a substituted or unsubstituted alicyclic oxiranyl; X 1 is a divalent hydrocarbon group or a halogenated hydrocarbon group);

[0022] Compound (A2), which is a polyfunctional polymerizable compound (excluding the compound (A1)); and compound (A3), which is a monofunctional polymerizable compound having one oxetanyl group in one molecule, and the total amount of the compound (A1), the compound (A2), and the compound (A3) is 85% by mass or more relative to the total amount of the polymerizable compounds.

[0023] [2] A curable composition containing a polymerizable compound and a polymerization initiator. In the curable composition, the polymerizable compound includes: the compound represented by the formula (1); a polyfunctional polymerizable compound (excluding the compound represented by the formula (1)); and a monofunctional polymerizable compound. The dielectric constant of the cured product of the curable composition at 25°C and a frequency of 250 kHz is 2.70 or less, and the glass transition temperature of the cured product is 85°C or higher.

[0024] [3] A cured film formed using the curable composition of [1] or [2].

[0025] [4] An organic EL element including an organic light-emitting layer and an organic sealing layer for sealing the organic light-emitting layer, and the organic sealing layer is formed using the curable composition of [1] or [2].

[0026] [5] A method for manufacturing an organic EL element, which manufactures an organic EL element including an organic light-emitting layer and an organic sealing layer for sealing the organic light-emitting layer. The manufacturing method includes: a step of coating the curable composition of [1] or [2] on the light-emitting layer formation surface of a substrate on which the organic light-emitting layer has been formed; and a step of forming the organic sealing layer by curing the curable composition by irradiating radiation.

[0027] [Effects of the Invention]

[0028] By the curable composition of the present invention, a cured product having a low dielectric constant and a sufficiently high glass transition temperature can be obtained. Detailed Description of Embodiments

[0029] Hereinafter, matters related to the embodiments will be described in detail. In addition, in this specification, the numerical range described using "~" means that the numerical values described before and after "~" are included as the lower limit value and the upper limit value.

[0030] In this specification, "hydrocarbyl group" means a group containing an acyclic hydrocarbyl group, an alicyclic hydrocarbyl group, and an aromatic hydrocarbyl group. The so-called "acyclic hydrocarbyl group" means a straight-chain or branched hydrocarbyl group that does not contain a cyclic structure in the main chain and is composed only of an acyclic structure. Among them, the acyclic hydrocarbyl group can be saturated or unsaturated. The so-called "alicyclic hydrocarbyl group" means a hydrocarbyl group that contains only an alicyclic hydrocarbon structure as a ring structure and does not contain an aromatic ring structure. Among them, the alicyclic hydrocarbyl group does not have to be composed only of an alicyclic hydrocarbon structure, and also includes a group having an acyclic structure in a part thereof. The so-called "aromatic hydrocarbyl group" means a hydrocarbyl group that contains an aromatic ring structure as a ring structure. Among them, the aromatic hydrocarbyl group does not have to be composed only of an aromatic ring structure, and may also contain an acyclic structure or an alicyclic hydrocarbon structure in a part thereof. In addition, the ring structure of the alicyclic hydrocarbyl group and the aromatic hydrocarbyl group may also have a substituent containing a hydrocarbon structure.

[0031] "Hardenable Composition"

[0032] The hardenable composition of the present disclosure (hereinafter, also referred to as "the present composition") contains a polymerizable compound and a polymerization initiator. The composition of the first embodiment in the present composition (hereinafter, also referred to as "the first composition") contains the following compounds (A1), (A2), and (A3) as polymerizable compounds.

[0033] · Compound (A1): A compound represented by the following formula (1)

[0034] R 1 -X 1 -R 2 …(1)

[0035] (In formula (1), R 1 and R 2 are each independently a substituted or unsubstituted alicyclic oxiranyl group; X 1 is a divalent hydrocarbyl group or a halogenated hydrocarbyl group)

[0036] · Compound (A2): A polyfunctional polymerizable compound (wherein compound (A1) is excluded)

[0037] · Compound (A3): A monofunctional polymerizable compound having one oxetanyl group in one molecule

[0038] Hereinafter, each component contained in the first composition and other components formulated as needed will be described. In addition, regarding each component, unless otherwise specified, one kind can be used alone, or two or more kinds can be used in combination.

[0039] <Polymerizable Compound>

[0040] The polymeric compound is a general term for compounds that are hardened by irradiating radiation or applying heat. The polymeric compound has, within one molecule, one or more functional groups (hereinafter, also referred to as "polymeric functional groups") that polymerize upon irradiation of radiation or application of heat.

[0041] As the polymeric compound, a compound having, as the polymeric functional group, one or more functional groups having cationic polymerizability (hereinafter, also referred to as "cationic polymerizable groups") can be preferably used. Examples of the cationic polymerizable group include an oxetanyl group, an oxiranyl group, a vinyl ether group, etc. From the viewpoint of polymerizability, a compound having an oxetanyl group or an oxiranyl group can be preferably used as the polymeric compound.

[0042] In terms of being easily adjusted to a viscosity suitable for inkjet coating, the molecular weight of the polymeric compound is, for example, 50 to 800, preferably 70 to 600, and more preferably 100 to 500.

[0043] The first composition contains, as the polymeric compound, a monofunctional compound having one polymeric functional group within one molecule and a polyfunctional compound having two or more polymeric functional groups within one molecule. In addition, among the polymeric compounds contained in the first composition, compound (A1) and compound (A2) are polyfunctional polymeric compounds, and compound (A3) is a monofunctional polymeric compound. Hereinafter, compound (A1) to compound (A3) will be described separately.

[0044] · Compound (A1)

[0045] Compound (A1) is the compound represented by the formula (1). In the formula (1), as R 1 or R 2 The preferred specific examples of the substituted or unsubstituted alicyclic oxiranyl group represented can be the group represented by the following formula (1a).

[0046] [Chemical formula 1]

[0047]

[0048] (In the formula (1a), R 7 is an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms; n is an integer of 0 to 3; "*" represents a bonding bond)

[0049] In the formula (1a), the alkyl group having 1 to 6 carbon atoms represented by R 7 can be linear or branched. Examples of the aryl group having 6 to 20 carbon atoms represented by R 7 include phenyl group, methylphenyl group, ethylphenyl group, dimethylphenyl group, diethylphenyl group, etc.

[0050] Among these, R 7 is preferably an alkyl group or a phenyl group having 1 to 3 carbon atoms.

[0051] n is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.

[0052] From the viewpoint of reactivity to radiation or heat, R 1 and R 2 are each preferably a substituted or unsubstituted 3,4-epoxycyclohexyl group among the above, and more preferably a 3,4-epoxycyclohexyl group.

[0053] In the formula (1), as the divalent hydrocarbon group represented by X 1 , examples include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, and a divalent aromatic hydrocarbon group. Specific examples of these are, as the divalent chain hydrocarbon group, a linear or branched divalent saturated hydrocarbon group having 1 to 20 carbon atoms and a linear or branched divalent unsaturated hydrocarbon group having 2 to 20 carbon atoms. Among these, the divalent chain hydrocarbon group represented by X 1 is preferably a linear or branched divalent saturated hydrocarbon group having 1 to 20 carbon atoms.

[0054] As the divalent alicyclic hydrocarbon group, examples include a group formed by removing two hydrogen atoms from the ring portion or the chain portion of an alicyclic hydrocarbon having a saturated aliphatic ring or an unsaturated aliphatic ring having 3 to 20 carbon atoms. Specific examples of the ring of the divalent alicyclic hydrocarbon group include monocyclic saturated alicyclic hydrocarbons such as cyclobutane ring, cyclopentane ring, cyclohexane ring, cycloheptane ring, cyclooctane ring; monocyclic unsaturated alicyclic hydrocarbons such as cyclobutene ring, cyclopentene ring, cyclohexene ring, cycloheptene ring, cyclooctene ring; polycyclic saturated alicyclic hydrocarbons such as decahydronaphthalene ring, octahydronaphthalene ring, norbornane ring, bicyclo[2.2.2]octane ring; polycyclic unsaturated alicyclic hydrocarbons such as norbornene ring, tetracyclo[6.2.1.1 3,6 .0 2,7 dodec-4-ene and other polycyclic unsaturated alicyclic hydrocarbons.

[0055] As the divalent aromatic hydrocarbon group, examples include a group formed by removing two hydrogen atoms from the ring portion or the chain portion of an aromatic hydrocarbon having a monocyclic or condensed ring (for example, benzene ring, naphthalene ring, anthracene ring).

[0056] As the divalent halogenated hydrocarbon group represented by X 1 , examples include a group in which one or more hydrogen atoms in the divalent hydrocarbon group are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.

[0057] In terms of achieving a low dielectric constant of the cured product obtained from the first composition and achieving a high Tg, X 1 is preferably a divalent group represented by the following formula (1b).

[0058] *-C(R 3 )(R 4 )-*…(1b)

[0059] (In formula (1b), R 3 and R 4 are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, or a phenyl group, or R 3 and R 4 are combined with each other and together with the carbon atom to which R 3 and R 4 are bonded form an alicyclic structure; "*" represents a bonding bond with the alicyclic oxirane ring structure)

[0060] In the said formula (1b), the alkyl group having 1 to 3 carbon atoms and the fluoroalkyl group represented by R 3 or R 4 may be linear or branched.

[0061] Examples of the alicyclic structure formed by R 3 and R 4 being combined with each other and together with the carbon atom to which R 3 and R 4 are bonded include a cyclopentane ring structure, a cyclohexane ring structure, a cycloheptane ring structure, etc. The alicyclic structure may also have a substituent on the ring part. Examples of the substituent include an alkyl group having 1 to 3 carbon atoms, a halogen atom, etc.

[0062] In terms of a higher improvement effect on reducing the dielectric constant and increasing the Tg of the cured product of the first composition, R 3 and R 4 are preferably each a hydrogen atom, a methyl group, an ethyl group, a trifluoromethyl group, or a phenyl group, or R 3 and R 4 are combined with each other and together with the carbon atom to which R 3 and R 4 are bonded form an alkyl-substituted or unsubstituted cyclohexane-1,1-diyl, more preferably a hydrogen atom, a methyl group, an ethyl group, or a trifluoromethyl group, and still more preferably R 3 and R 4 are both methyl groups.

[0063] As a preferred specific example of the compound (A1), a compound represented by the following formula (1-1) can be cited.

[0064] [Chemical formula 2]

[0065]

[0066] (In formula (1-1), R 3 and R 4Each independently is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, or a phenyl group, or represents R 3 and R 4 are bonded to each other and together with the carbon atom to which R 3 and R 4 is bonded form an alicyclic structure; R 5 and R 6 Each independently is an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms; n1 and n2 are each independently an integer from 0 to 3)

[0067] In the formula (1-1), regarding R 3 and R 4 , the specific examples and preferred examples are the same as those of R 3 and R 4 in the formula (1b).

[0068] Regarding R 5 and R 6 , the specific examples and preferred examples are the same as the groups exemplified in the description of R 7 in the formula (1a).

[0069] n1 and n2 are preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.

[0070] As further specific examples of the compound (A1), there may be mentioned: bis(3,4-epoxycyclohexyl)methane, 1,1-bis(3,4-epoxycyclohexyl)ethane, 1,2-bis(3,4-epoxycyclohexyl)ethane, 2,2-bis(3,4-epoxycyclohexyl)propane, 2,2-bis(3,4-epoxycyclohexyl)hexafluoropropane, 2,2-bis(3,4-epoxycyclohexyl)butane, 1,1-bis(3,4-epoxycyclohexyl)cyclohexane, 1,1-bis(3,4-epoxycyclohexyl)-3,3,5-trimethylcyclohexane and the like.

[0071] Among the said compounds, the compound (A1) is preferably at least one selected from the group consisting of bis(3,4-epoxycyclohexyl)methane, 1,1-bis(3,4-epoxycyclohexyl)ethane, 1,2-bis(3,4-epoxycyclohexyl)ethane, 2,2-bis(3,4-epoxycyclohexyl)propane, 2,2-bis(3,4-epoxycyclohexyl)hexafluoropropane and 2,2-bis(3,4-epoxycyclohexyl)butane, more preferably at least one selected from the group consisting of 1,1-bis(3,4-epoxycyclohexyl)ethane, 2,2-bis(3,4-epoxycyclohexyl)propane, 2,2-bis(3,4-epoxycyclohexyl)hexafluoropropane and 2,2-bis(3,4-epoxycyclohexyl)butane, and particularly preferably 2,2-bis(3,4-epoxycyclohexyl)propane.

[0072] In this composition, the content of compound (A1) is preferably 10% by mass to 60% by mass relative to the total amount of the polymerizable compounds contained in this composition. If the content of compound (A1) is within the above range, the following effects can be sufficiently improved, that is, the effects of achieving both a lower dielectric constant and a higher Tg of the cured product obtained by using this composition. From the viewpoint of sufficiently obtaining the improvement effects of a lower dielectric constant and a higher Tg of the cured product, the content of compound (A1) is more preferably 15% by mass or more, further preferably 20% by mass or more, and still more preferably 30% by mass or more. In addition, from the viewpoint of formulating a compound different from compound (A1) as a polymerizable compound to improve curability and the like, the content of compound (A1) is more preferably 55% by mass or less relative to the total amount of the polymerizable compounds.

[0073] · Compound (A2)

[0074] Compound (A2) is formulated into the first composition in order to further improve the curability of the curable composition. Compound (A2) may be any polyfunctional polymerizable compound as long as it is not included in the formula (1). Examples of compound (A2) include: polyfunctional oxirane compounds (excluding compound (A1)), polyfunctional oxetane compounds, polyfunctional vinyl ether compounds, and the like.

[0075] Examples of polyfunctional oxirane compounds include: compounds having two or more glycidyl groups per molecule (hereinafter, also referred to as "polyfunctional glycidyl compounds (a2)"), and compounds having two or more substituted or unsubstituted alicyclic oxiranyl groups and not included in the formula (1) (hereinafter, also referred to as "polyfunctional alicyclic oxirane compounds (a2)").

[0076] Among polyfunctional oxirane compounds, specific examples of polyfunctional glycidyl compounds (a2) include: silicone compounds having two or more glycidyl groups in the molecule, such as the product named "X-40-2728" (manufactured by Shin-Etsu Chemical Co., Ltd., etc.);

[0077] Resins containing epoxy groups such as bisphenol A epoxy resin, bisphenol E epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol O epoxy resin, 2,2'-diallylbisphenol A epoxy resin, hydrogenated bisphenol epoxy resin, propylene oxide adduct bisphenol A epoxy resin, resorcinol epoxy resin, biphenyl epoxy resin, thioether epoxy resin, diphenyl ether epoxy resin, dicyclopentadiene epoxy resin, naphthalene epoxy resin, phenol novolac epoxy resin, o-cresol novolac epoxy resin, dicyclopentadiene novolac epoxy resin, biphenyl novolac epoxy resin, naphthalene phenol novolac epoxy resin, glycidylamine epoxy resin, alkyl polyol epoxy resin, rubber-modified epoxy resin, glycidyl ester resin, bisphenol A thioepoxy resin, etc.

[0078] Specific examples of the polyfunctional alicyclic oxirane compound (a2) include: 3,4-epoxycyclohexylmethyl 3',4'-epoxycyclohexanecarboxylate, bis(3,4-epoxycyclohexylmethyl) adipate, bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate, etc. In addition, as commercially available products, they can be listed by trade name: Celloxide 2021P, Celloxide 8010 (manufactured by Daicel Corporation); KR-470, X-40-2669, X-40-2670, X-40-2678 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc.

[0079] The polyfunctional oxetane compound may be a compound having two or more oxetane rings per molecule. Specific examples of the polyfunctional oxetane compound include: 3,7-bis(3-oxetanyl)-5-oxa-nonane, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, 1,2-bis[(3-ethyl-3-oxetanylmethoxy)methyl]ethane, 1,3-bis[(3-ethyl-3-oxetanylmethoxy)methyl]propane, bis[1-ethyl(3-oxetanyl)]methyl ether, bis(3-ethyl-3-oxetanylmethyl)ether, ethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, triethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, tetraethylene glycol bis(3-ethyl-3-oxetanylmethyl)ether, 1,3-bis(3-ethyl-3-oxetanylmethoxy)propane, 1,4-bis(3-ethyl-3-oxetanylmethoxy)butane, 1,4-bis(3-ethyl-3-oxetanylmethoxymethyl)benzene, 1,3-bis(3-ethyl-3-oxetanylmethoxymethyl)benzene, 1,2-bis(3-ethyl-3-oxetanylmethoxymethyl)benzene, 4,4'-bis(3-ethyl-3-oxetanylmethoxymethyl)biphenyl, 2,2'-bis(3-ethyl-3-oxetanylmethoxymethyl)biphenyl, 1,6-bis((3-methyloxetane-3-yl)methoxy)hexane, 1,6-bis((3-ethyloxetane-3-yl)methoxy)hexane, a hydrolysis condensate of 3-[(3-ethyloxetane-3-yl)methoxy]propyltrialkoxysilane, a condensation reaction product of 3-ethyloxetane-3-ylmethanol and a silane tetrol condensate, compounds represented by the following formulas (2a-1) to (2a-3), etc.

[0080] [Chemical formula 3]

[0081]

[0082] The polyfunctional vinyl ether compound may be a compound having two or more vinyl ether groups per molecule. Specific examples of the polyfunctional vinyl ether compound include: alkanediol divinyl ether, cycloalkanediol divinyl ether, cycloalkanedimethanol divinyl ether, (poly)ethylene glycol divinyl ether, trimethylolpropane divinyl ether, pentaerythritol divinyl ether, trimethylolpropane trivinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, dipentaerythritol hexavinyl ether and other compounds having a plurality of vinyl ether groups, epoxy alkane modified products or caprolactone modified products of these compounds.

[0083] The number of polymerizable functional groups in the compound (A2) per molecule is preferably 2 to 10, more preferably 2 to 6, and still more preferably 2 to 4.

[0084] In terms of being easily adjusted to a viscosity suitable for inkjet coating, the molecular weight of the polymerizable compound is preferably 50 to 800, more preferably 70 to 600, and still more preferably 100 to 500.

[0085] In terms of obtaining a curable composition that can achieve a low dielectric constant of the cured product and exhibits excellent curability, as the compound (A2), in the compound, at least one selected from the group consisting of a compound having a total of two or more oxetane rings in the molecule (i.e., a polyfunctional oxetane compound) and a polyfunctional alicyclic propylene oxide compound (a2) can be preferably used, and more preferably a polyfunctional oxetane compound is included. With respect to the total amount of the compound (A2) contained in the present composition, the proportion of the polyfunctional oxetane compound is preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 65% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0086] In terms of obtaining a curable composition that can achieve a low dielectric constant of the cured product and has excellent curability, the content of the compound (A2) is preferably 5% by mass to 70% by mass with respect to the total amount of the polymerizable compound contained in the present composition. In terms of improving the curability of the curable composition, the content of the compound (A2) is more preferably 10% by mass or more, and still more preferably 20% by mass or more with respect to the total amount of the polymerizable compound contained in the present composition. In addition, in terms of achieving a high Tg of the cured product, the content of the compound (A2) is more preferably 67% by mass or less, and still more preferably 65% by mass or less with respect to the total amount of the polymerizable compound contained in the present composition.

[0087] In terms of achieving a high Tg and a low dielectric constant of the cured film in a well-balanced manner, it is preferable that the content of the compound (A1) is 20% by mass or more with respect to the total amount of the polymerizable compound, or the total amount of the compound (A1) and the compound (A2) is 60% by mass or more with respect to the total amount of the polymerizable compound. In terms of making the high Tg and the low dielectric constant of the cured film more excellent, it is more preferable that the content of the compound (A1) is 30% by mass or more with respect to the total amount of the polymerizable compound, or the total amount of the compound (A1) and the compound (A2) is 70% by mass or more with respect to the total amount of the polymerizable compound.

[0088] · Compound (A3)

[0089] Compound (A3) is a monofunctional polymerizable compound having an oxetanyl group in one molecule (i.e., a monofunctional oxetane compound). The monofunctional compound (A3) can be formulated into the first composition in order to improve the wetting spreadability of the curable composition. In addition, since compound (A3) has an oxetanyl group as a polymerizable functional group, it is not likely to remain as an unreacted polymerizable compound in the cured product, and thus outgassing from the cured product can be reduced.

[0090] The monofunctional oxetane compound may be a compound having one oxetane ring per molecule. Specific examples of the monofunctional oxetane compound include, for example: 3-ethyl-3-((2-ethylhexyloxy)methyl)oxetane, phenoxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3-(phenoxymethyl)oxetane, 3-ethyl-3-((3-(triethoxysilyl)propoxy)methyl)oxetane, 3-allyloxyoxetane, 3-ethyl-3-allyloxyoxetane, 3-ethyl-3-acryloyloxymethyloxetane, 3-ethyl-3-methacryloyloxymethyloxetane, 2-methyl-2-allyl-4-propyloxetane, 3-ethyl-3-(4-acryloyloxybutyloxymethyl)oxetane, 3-ethyl-3-(3-acryloyloxy-2,2-dimethylpropyloxymethyl)oxetane, 3-methyl-3-methoxyoxetane, phenyloxetane, 3-ethyl-3-chloromethyloxetane, 3-ethyl-3-oxetane methanol, 3-amino-3-dimethyloxetane, compounds represented by the following formulas (3a-1) to (3a-21), etc.

[0091] [Chemical formula 4]

[0092]

[0093] From the viewpoints of achieving a low dielectric constant of the cured product, suppressing an excessive increase in the viscosity of the curable composition, and making the wetting spreadability of the curable composition good, the content of compound (A3) is preferably 20% by mass to 70% by mass relative to the total amount of the polymerizable compounds contained in the present composition. From the viewpoint of making the wetting spreadability of the curable composition more excellent, the content of compound (A3) is more preferably 30% by mass or more, and further preferably 35% by mass or more, relative to the total amount of the polymerizable compounds contained in the present composition. In addition, from the viewpoint of obtaining a cured product having a sufficiently high mechanical strength and a low dielectric constant, the content of compound (A3) is more preferably 60% by mass or less, and further preferably 50% by mass or less, relative to the total amount of the polymerizable compounds contained in the present composition.

[0094] The total amount of compound (A1), compound (A2), and compound (A3) in the first composition is 85% by mass or more relative to the total amount of the polymerizable compounds contained in the first composition. If the total amount of compound (A1), compound (A2), and compound (A3) is less than 85% by mass relative to the total amount of the polymerizable compounds contained in the first composition, there is a tendency that the balance between the low dielectric constant and the high Tg of the glass transition temperature of the cured product obtained from this composition cannot be maintained. In addition, the amount of outgassing from the cured product tends to increase. From the viewpoint of obtaining a cured product with a low dielectric constant, a sufficiently high glass transition temperature, and less outgassing, the total amount of compound (A1), compound (A2), and compound (A3) in the first composition is more preferably 90% by mass or more, still more preferably 95% by mass or more, and even more preferably 98% by mass or more relative to the total amount of the polymer compounds contained in the first composition.

[0095] · Other polymerizable compounds

[0096] The first composition may contain only compound (A1), compound (A2), and compound (A3) as polymerizable compounds. In addition, for the purpose of adjusting the curability or viscosity of this composition, etc., while containing compound (A1), compound (A2), and compound (A3), a compound different from compound (A1), compound (A2), and compound (A3) (hereinafter, also referred to as "other polymerizable compounds") may also be contained. Examples of other polymerizable compounds include monofunctional oxirane compounds and monofunctional vinyl ether compounds.

[0097] Regarding specific examples of other polymerizable compounds, as monofunctional oxirane compounds, examples include: cyclohexene oxide, 1-methyl-1,2-epoxycyclohexane, 1,2-epoxy-4-vinylcyclohexane, ethyl glycidyl ether, butyl glycidyl ether, 1,2-epoxytetradecane, etc.

[0098] Specific examples of monofunctional vinyl ether compounds include: cyclohexyl vinyl ether, ethylhexyl vinyl ether, hydroxyethyl vinyl ether, etc.

[0099] From the viewpoint of fully achieving the low dielectric constant and high Tg of the cured product, or reducing the amount of outgassing from the cured product, the content of other polymerizable compounds is 15% by mass or less, preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 2% by mass or less relative to the total amount of the polymerizable compounds contained in this composition.

[0100] In terms of suppressing the generation amount of outgassing from the cured product and increasing the glass transition temperature of the cured product, this composition preferably does not contain a monofunctional oxirane compound formed by bonding a monovalent chain group and an oxiranyl group (for example, ethyl glycidyl ether, butyl glycidyl ether, 1,2-epoxyalkane, etc.), or the content of the monofunctional oxirane compound is as small as possible. Specifically, in this composition, relative to the total amount of this composition, the content of the monofunctional oxirane compound formed by bonding a monovalent chain group and an oxiranyl group is preferably 0% by mass or more and 10% by mass or less, more preferably 0% by mass or more and 5% by mass or less, still more preferably 0% by mass or more and 1% by mass or less, and even more preferably 0% by mass or more and 0.5% by mass or less.

[0101] The molar ratio of the oxiranyl group to the oxetanyl group in the polymerizable compound is preferably 1:0.5 to 1:8. By setting the molar ratio of the oxiranyl group to the oxetanyl group within the above range, the curing reactivity of this composition can be made more excellent. In addition, the generation amount of outgassing from the cured product can be reduced as much as possible, and the low dielectric constant of the cured product can be fully achieved. The molar ratio of the oxiranyl group to the oxetanyl group in the polymerizable compound is more preferably 1:1 to 1:4, and still more preferably 1:1 to 1:3.

[0102] <Polymerization initiator>

[0103] The polymerization initiator may be a substance that generates a protonic acid or a Lewis acid in response to heat or light. As such a polymerization initiator, it can be appropriately selected and used from substances known as thermal cationic polymerization initiators or photo cationic polymerization initiators. In terms of suppressing the deterioration of the element, the polymerization initiator is preferably a photo cationic polymerization initiator among these. As the photo cationic polymerization initiator, for example, ionic photoacid-generating or non-ionic photoacid-generating polymerization initiators can be cited.

[0104] As the ionic photoacid-generating photo cationic polymerization initiator, for example, the following can be cited: onium salt compounds, halogen-containing compounds, sulfone compounds, sulfonic acid compounds, sulfonimide compounds, and diazomethane compounds. As the onium salt compound, specifically, the following can be cited: the cation part is aromatic sulfonium, aromatic iodonium, aromatic diazonium, aromatic ammonium, or (2,4-cyclopentadien-1-yl)[(1-methylethyl)benzene]-Fe cation, and the anion part contains BF 4 - 、PF 6 - 、SbF 6 - 、[BX 4 - (X is a phenyl group substituted with two or more fluorine or trifluoromethyl groups), or [PG​6 - (where G is a fluorinated alkyl group) onium salt.

[0105] As a polymerization initiator, the onium salt compound in the above can be preferably used. Among them, the polymerization initiator is preferably one containing [PF k (C p F 2p+1 ) 6-k - represented anionic moiety (wherein k is an integer of 3 to 5, p is an integer of 1 to 3) of onium fluorinated alkyl fluorophosphate. [PF k (C p F 2p+1 ) 6-k - represented anionic moiety due to (C p F 2p+1 ) is 1 or more and has a fluorocarbon chain, so it acts as a relatively strong acid. Therefore, the cationic polymerization performance becomes high, and it is considered that by using such an onium salt, the curability can be made more excellent.

[0106] The cationic part of the onium fluorinated alkyl fluorophosphate is not particularly limited. As a specific example of the cationic part, for example, the sulfonium cation represented by the following formula (4) can be cited.

[0107] [Chemical formula 5]

[0108]

[0109] (In formula (4), R 11 ~R 14 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, an alkylcarbonyloxy group having 1 to 6 carbon atoms, an alkylcarbonylthio group having 1 to 6 carbon atoms or an alkoxycarbonyloxy group having 1 to 6 carbon atoms; r is 0 or 1)

[0110] In the formula (4), R 11 ~R 14 are preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a methoxy group, a methylthio group, a methylcarbonyloxy group, a methylcarbonylthio group or a methoxycarbonyloxy group, and more preferably a hydrogen atom.

[0111] As an ionic photoacid-generating type photo cationic polymerization initiator, commercially available products can be used. For example, as a product containing the cationic part represented by the formula (4) and [PF k (C p F 2p+1 ) 6-k - ​​​Commercially available photo cationic polymerization initiators for the anionic moiety represented can be listed by trade name, such as "CPI-210S", "CPI-410S" (manufactured by San-apro Co., Ltd., etc.). In addition, commercially available products of aromatic sulfonium salts can be listed by trade name, such as "ES-1B", "ES-1S" (manufactured by San-apro Co., Ltd., etc.).

[0112] Examples of nonionic photoacid-generating photo cationic polymerization initiators include nitrobenzyl esters, sulfonic acid derivatives, phosphate esters, phenol sulfonic acid esters, diazonaphthoquinones, N-hydroxyimide sulfonic acid esters, oxime ester carboxylic acid esters, etc.

[0113] In this composition, relative to 100 parts by mass of the total amount of the polymerizable compounds contained in this composition, the content of the polymerization initiator is usually 0.1 part by mass to 10 parts by mass. Relative to 100 parts by mass of the total amount of the polymerizable compounds, the content of the polymerization initiator is preferably 7 parts by mass or less, more preferably 5 parts by mass or less. By setting the content of the polymerization initiator within the above range, the curability of this composition can be made good, and in addition, a cured film with high transparency can be obtained.

[0114] <Other components>

[0115] In addition to the above-mentioned polymerizable compounds and polymerization initiators, this composition may also contain components different from the polymerizable compounds and polymerization initiators (hereinafter, also referred to as "other components"). Examples of other components include polymerization inhibitors, antioxidants, sensitizers, surfactants, etc.

[0116] ·Polymerization inhibitor / antioxidant

[0117] This composition may also contain at least one compound selected from the group consisting of polymerization inhibitors and antioxidants (hereinafter, also referred to as "additive (C)"). By this composition also containing additive (C), the storage stability of this composition can be improved.

[0118] As the polymerization inhibitor, there is no particular limitation, and examples thereof include: hydroquinone, p-methoxyphenol, p-benzoquinone, naphthoquinone, phenanthraquinone, toluquinone, 2,5-diacetoxy-p-benzoquinone, 2,5-dihexanoyloxy-p-benzoquinone, 2,5-acetyloxy-p-benzoquinone, 2,5-di-tert-butyl-3-methylphenol, p-tert-butylcatechol, 2,5-di-tert-butylhydroquinone, p-tert-butylcatechol, mono-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, di-tert-butyl-p-cresol p-hydroquinone monomethyl ether, phenothiazine, α-naphthol, acetamidine acetate, acetamidine sulfate, phenylhydrazine hydrochloride, hydrazine hydrochloride, trimethylbenzylammonium chloride, laurylpyridinium chloride, cetyltrimethylammonium chloride, phenyltrimethylammonium chloride, trimethylbenzylammonium oxalate, bis(trimethylbenzylammonium) oxalate, trimethylbenzylammonium maleate, trimethylbenzylammonium tartrate, trimethylbenzylammonium glycolate, phenyl-β-naphthylamine, p-benzylaminophenol, di-β-naphthyl-p-phenylenediamine, dinitrobenzene, trinitrotoluene, picric acid, cyclohexanone oxime, pyrogallol, tannic acid, resorcinol, triethylamine hydrochloride, dimethylaniline hydrochloride, dibutylamine hydrochloride, and the like.

[0119] When a polymerization inhibitor is formulated in the present composition, the content of the polymerization inhibitor is preferably 0.01 part by mass to 10 parts by mass, more preferably 0.01 part by mass to 5 parts by mass, and still more preferably 0.01 part by mass to 3 parts by mass, based on 100 parts by mass of the total amount of the polymerizable compound contained in the present composition. By setting it within the above range, it is possible to suppress an increase in viscosity caused by unnecessary heat energy, or the occurrence of a gelation or hardening reaction, and the viscosity of the present composition can be maintained within an appropriate range even after long-term circulation or storage, ensuring good wetting spreadability (and thus inkjet coatability).

[0120] · Antioxidant

[0121] The antioxidant is used to improve the storage stability of the present composition by preventing oxidative deterioration of the curable composition. Examples of the antioxidant include phenolic antioxidants, sulfur-based antioxidants, phosphorus-based antioxidants, and the like.

[0122] Regarding specific examples of antioxidants, as phenolic antioxidants, the following can be cited: monophenols such as 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-butyl-p-ethylphenol, and stearyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate; bisphenols such as 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-thiobis(3-methyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), and 3,9-bis[1,1-dimethyl-2-{β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy}ethyl] 2,4,8,10-tetraoxaspiro[5,5]undecane; polymeric phenols such as 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tetra-[methylene-3-(3',5'-di-tert-butyl-4'-hydroxyphenyl) propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-tert-butylphenyl)butyric acid] glycol ester, 1,3,5-tris(3',5'-di-tert-butyl-4'-hydroxybenzyl)-S-triazine-2,4,6-(1H,3H,5H) trione, and tocopherol.

[0123] As sulfur-based antioxidants, the following can be cited: dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, etc.

[0124] As phosphorus-based antioxidants, the following can be cited: phosphite esters such as diphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecyl pentaerythritol phosphite, tris(2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetrayl bis(octadecyl) phosphite, cyclic neopentanetetrayl bis(2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetrayl bis(2,4-di-tert-butyl-6-methylphenyl) phosphite, and bis[2-tert-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl] hydrogen phosphite; oxaphosphaphenanthrene oxides such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-tert-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide.

[0125] The antioxidants can be used separately, and it is particularly preferred to use them in combination with phenolic / sulfur-based or phenolic / phosphorus-based. In addition, commercially available phenolic antioxidants (e.g., IRGANOX 1010 (trade name) manufactured by BASF Japan Co., Ltd.) or commercially available phosphorus-based antioxidants (e.g., IRGAFOS 168 (trade name) manufactured by BASF Japan Co., Ltd.) can be used separately, and these can also be used in combination.

[0126] When an antioxidant is formulated in this composition, the content of the antioxidant is preferably 0.01 parts by mass to 10 parts by mass, more preferably 0.01 parts by mass to 5 parts by mass, and still more preferably 0.01 parts by mass to 3 parts by mass, based on 100 parts by mass of the total amount of the polymerizable compounds contained in this composition. By setting it within the above range, an increase in viscosity caused by unnecessary heat energy, or the occurrence of gelation or hardening reactions can be suppressed, and the viscosity of this composition can be maintained within an appropriate range even after long-term circulation or storage, ensuring good wetting spreadability (and thus inkjet coating properties).

[0127] In addition, in order to improve the storage stability of this composition, in addition to containing the additive (C), this composition can also contain heat stabilizers such as methylene quinone or 2-dimethylaminomethanol described in Japanese Patent Publication No. 2020-518952.

[0128] · Sensitizer

[0129] Sensitizers can be used for the purpose of minimizing the amount of polymerization initiator used as much as possible, thereby improving the transparency of the cured product, etc. Specific examples of sensitizers include, for example: polynuclear aromatics such as pyrene, perylene, triphenylene, anthracene, 9,10-dibutoxyanthracene, 9,10-diethoxyanthracene, 3,7-dimethoxyanthracene, 9,10-dipropyloxyanthracene; xanthenes such as fluorescein, eosin, erythrosin, rhodamine B, rose Bengal; xanthones such as xanthone, thioxanthone, dimethylthioxanthone, diethylthioxanthone (such as 2,4-diethylthioxanthen-9-one), isopropylthioxanthone (such as 2-isopropylthioxanthone); cyanines such as thiacarbocyanine, oxacarbocyanine; merocyanines such as merocyanine, carbomerocyanine; thiazines such as thionine, methylene blue, toluidine blue; acridines such as acridine orange, chloroflavin, acridine flavin; acridones such as acridone, 10-butyl-2-chloroacridone; basic styryl compounds such as 2-[2-[4-(dimethylamino)phenyl]vinyl]benzoxazole; coumarins such as 7-diethylamino-4-methylcoumarin, 7-hydroxy-4-methylcoumarin, 2,3,6,7-tetrahydro-9-methyl-1H,5H,11H[l]benzopyrano[6,7,8-ij]quinazolin-11-one; rhodacyanines; oxonols; anthraquinones; squaraine inner salts; styryl compounds, etc.

[0130] When a sensitizer is formulated in the present composition, the content of the sensitizer is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and still more preferably 0.2 to 3 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable compounds contained in the present composition. By setting it within the above range, the transparency of the cured product can be further improved.

[0131] · Surfactant

[0132] Surfactants can be used to improve the coatability of the present composition (specifically, wetting spreadability or reduction of coating unevenness), or the surface flatness of the cured product. Examples of surfactants include, for example: fluorine-based surfactants, silicone-based surfactants, nonionic surfactants.

[0133] As specific examples of surfactants, as fluorosurfactants, the following can be listed by trade name: Megafac F-171, Megafac F-172, Megafac F-173, Megafac F-251, Megafac F-430, Megafac F-554, Megafac F-556, Megafac F-557, Megafac F-559, Megafac F-560, Megafac F-563 (manufactured by DIC Corporation); Fluorad FC430, Fluorad FC431 (manufactured by Sumitomo 3M Limited); Asahi Guard AG710, Surflon S-382, Surflon SC-101, Surflon SC-102, Surflon SC-103, Surflon SC-104, Surflon SC-105, Surflon SC-106, Surflon S-611 (manufactured by AGC SEIMI Chemical Co., Ltd.); Polyflow No.75, Polyflow No.95 (manufactured by Kyoeisha Chemical Co., Ltd.); FTX-218 (manufactured by NEOS Co., Ltd.); Eftop EF301, Eftop EF303, Eftop EF352 (manufactured by Shin-Akita Chemical Co., Ltd.), and the like.

[0134] As silicone surfactants, the following trade names can be listed: SH200-100cs, SH28PA, SH30PA, SH89PA, SH190, SH8400, SH193, SZ6032, SF8428, DC57, DC190, Paintad 19, FZ-2101, FZ-77, FZ-2118, L-7001, L-7002 (manufactured by Toray Dow Corning Co., Ltd. as above); organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); BYK-300, BYK-306, BYK-310, BYK-330, BYK-333, BYK-335, BYK-341, BYK-344, BYK-370, BYK-340, BYK-345 (manufactured by BYK-Chemie Japan Co., Ltd. as above).

[0135] As nonionic surfactants, for example, the following can be listed: polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, etc.

[0136] When a surfactant is formulated in this composition, based on 100 parts by mass of the total amount of the polymerizable compounds contained in this composition, the content of the surfactant is preferably 0.01 part by mass to 5 parts by mass, more preferably 0.02 part by mass to 3 parts by mass, and still more preferably 0.1 part by mass to 2 parts by mass.

[0137] As other components, in addition to the components mentioned above, for example, softeners, plasticizers, adhesion aids, organic solvents, etc. can be listed. The blending ratios of these components can be appropriately selected according to each component within the range that does not impair the effects of the present disclosure.

[0138] For the purpose of dissolving each component formulated in this composition, an organic solvent can also be formulated in this composition. On the other hand, from the viewpoint of being able to form a cured film (especially an organic sealing layer for protecting the organic light-emitting layer of an organic EL element) without heat treatment, it is preferable to minimize the amount of the organic solvent used. Specifically, the content of the organic solvent in this composition is preferably 0% by mass or more and 3% by mass or less, more preferably 0% by mass or more and 2% by mass or less, still more preferably 0% by mass or more and 1% by mass or less, and even more preferably 0% by mass or more and 0.5% by mass or less.

[0139] When the composition contains an organic solvent, as the organic solvent used, an organic solvent that can dissolve or disperse each component formulated in the composition and does not react with each component is preferably used. Specifically, examples include: alcohols, ketones, esters, ethers, aromatic hydrocarbons, amides.

[0140] Regarding specific examples of these, as alcohols, examples include: methanol, ethanol, isopropanol, butanol, octanol, etc. As ketones, examples include: acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc. As esters, examples include: ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl-3-methoxypropionate, etc. As ethers, examples include: polyoxyethylene lauryl ether, ethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, diethylene glycol methyl ethyl ether, etc. As aromatic hydrocarbons, examples include: benzene, toluene, xylene, etc. As amides, examples include: dimethylformamide, dimethylacetamide, N-methylpyrrolidone and other amides, etc.

[0141] The composition of the second embodiment in the present composition (hereinafter, also referred to as "second composition") contains the following compound (A1), compound (A2) and compound (B3) as polymerizable compounds.

[0142] · Compound (A1): A compound represented by the following formula (1)

[0143] R 1 -X 1 -R 2 …(1)

[0144] (In formula (1), R 1 and R 2 are each independently a substituted or unsubstituted alicyclic oxiranyl; X 1 is a divalent hydrocarbon group or a halogenated hydrocarbon group)

[0145] · Compound (A2): A polyfunctional polymerizable compound (excluding compound (A1))

[0146] · Compound (B3): A monofunctional polymerizable compound

[0147] In addition, regarding the second composition, the following will be described mainly focusing on the differences from the first composition.

[0148] Regarding the specific examples and preferred examples of compound (A1) and compound (A2) contained in the second composition, as well as the content, the description is the same as that of the compounds exemplified as compound (A1) and compound (A2) contained in the first composition, so the description thereof is omitted.

[0149] The compound (B3) contained in the second composition is not particularly limited as long as the dielectric constant of the cured product obtained by curing the second composition at 25°C and a frequency of 250 kHz is 2.70 or less and the glass transition temperature of the cured product is 85°C or higher. In terms of minimizing the generation of outgassing from the cured product, as the compound (B3), a monofunctional polymerizable compound having one oxetanyl group in one molecule (i.e., a monofunctional oxetane compound) can be preferably used. The proportion of the monofunctional oxetane compound is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and even more preferably 90% by mass or more, relative to the total amount of the compound (B3) contained in the second composition.

[0150] From the viewpoints of achieving a low dielectric constant of the cured product, suppressing an excessive increase in the viscosity of the curable composition, and making the wetting and spreading properties of the curable composition good, the content of the compound (B3) is preferably 30% by mass to 70% by mass relative to the total amount of the polymerizable compounds contained in the present composition. From the viewpoint of making the wetting and spreading properties of the curable composition more excellent, the content of the compound (B3) is more preferably 35% by mass or more relative to the total amount of the polymerizable compounds contained in the present composition. In addition, from the viewpoint of obtaining a cured product with sufficiently high mechanical strength and a low dielectric constant, the content of the compound (B3) is more preferably 60% by mass or less, and still more preferably 50% by mass or less, relative to the total amount of the polymerizable compounds contained in the present composition.

[0151] The second composition may contain only the compounds (A1), (A2), and (B3) as polymerizable compounds. In addition, for the purpose of adjusting the curability or viscosity of the present composition, etc., while containing the compounds (A1), (A2), and (B3), a compound different from the compounds (A1), (A2), and (B3) may also be contained.

[0152] Details of the polymerization initiator contained in the second composition and the components optionally contained in the second composition are the same as those of the first composition, and thus the description thereof is omitted.

[0153] <Preparation of curable composition>

[0154] The present composition can be prepared by mixing polymerizable compounds, a polymerization initiator, and other components optionally formulated. From the viewpoint of making a curable composition with good sensitivity or forming a cured film with a high sealing effect, the content of the polymerizable compounds in the present composition is preferably 80 parts by mass or more, more preferably 85 parts by mass or more, and still more preferably 90 parts by mass or more, relative to 100 parts by mass of the total amount of the present composition.

[0155] <Viscosity of the curable composition>

[0156] The viscosity of the present composition measured with an E-type viscometer at 25°C and 20 rpm is preferably in the range of 1.0 mPa·s to 40.0 mPa·s. If the viscosity of the present composition is 40.0 mPa·s or less, when the present composition is coated on a substrate by inkjet coating, the wetting spreadability is good, and the coating unevenness caused by depressions and the like can be sufficiently suppressed. In addition, if the viscosity of the present composition is 1.0 mPa·s or more, when the present composition is coated on a substrate, the film thickness can be sufficiently ensured, and an organic sealing layer that sufficiently exhibits the sealing effect can be formed. The present composition is preferably a curable composition for inkjet coating.

[0157] From the viewpoint of obtaining a curable composition with excellent inkjet coatability, the viscosity of the present composition is more preferably 35.0 mPa·s or less, further preferably 30.0 mPa·s or less, and particularly preferably 25.0 mPa·s or less. In addition, from the viewpoint of stably ejecting by inkjet and sufficiently ensuring the film thickness, the viscosity of the present composition is more preferably 2.0 mPa·s or more, and further preferably 5.0 mPa·s or more. In addition, in this specification, the viscosity of the curable composition is a value measured according to Japanese Industrial Standards (JIS) K2283.

[0158] <Curable product and organic EL element>

[0159] The cured product of the present disclosure (hereinafter, also referred to as "the present cured product") is formed from the curable composition prepared as described above. According to this composition, a cured product with a low dielectric constant, a high glass transition temperature, and less outgassing can be obtained. Such a composition of the present disclosure can be used, for example, as various materials such as a sealing structure of an organic EL element, a microlens, an antireflection film, and a diffraction grating of an Augmented Reality (AR) element. In addition, this composition can also be used as a hole filling material for a hole such as an HID (Hole In a Display area) structure or a material for forming a planarization film. Further, according to this composition, the water permeability is low, the intrusion of foreign substances can be prevented, and a cured film excellent in bending resistance can be formed. Therefore, it can also be used as a material for forming a coating layer for protecting wirings in a bent portion of a flexible display or a bend allowance part provided with a wiring extending from a display portion to the outside. As the coating layer in the bent portion, for example, a MICRO-COATING LAYER described in International Publication No. 2016 / 09925 can be mentioned. The formation of the microcoating layer can be carried out by slit coating or inkjet coating. This composition is useful in that it can cope with any of these coating methods. This composition is particularly useful as a composition for forming a sealing structure for thin film sealing (Thin Film Encapsulation (TFE)) of an organic electroluminescent element (organic EL element), that is, a sealant for an organic EL element.

[0160] <Dielectric Constant of Cured Product>

[0161] The dielectric constant of the present cured product is preferably 2.70 or less at 25°C and a frequency of 250 kHz. If the dielectric constant under the above measurement conditions is 2.70 or less, when forming a low dielectric constant layer of a device (e.g., an organic EL light emitting device) using a touch panel method with the curable composition, the dielectric constant of the low dielectric constant layer can be sufficiently reduced, and the occurrence of malfunction during the use of the touch panel can be suppressed. From the viewpoint of forming a low dielectric constant layer showing desired performance, the dielectric constant of the cured product at 25°C and a frequency of 250 kHz is more preferably 2.69 or less, and still more preferably 2.68 or less. There is no particular limitation on the lower limit of the dielectric constant of the cured product. The dielectric constant of the cured product at 25°C and a frequency of 250 kHz is, for example, 2.0 or more.

[0162] In addition, regarding the method for measuring the dielectric constant, specifically, an ultraviolet-light emitting diode (UV-LED) lamp with a wavelength of 395 nm is used, and at an illuminance of 1,000 mW / cm2 and under the condition that the cumulative light amount is 1,000 mJ / cm 2 Ultraviolet rays are irradiated to this composition, and for the cured product thus obtained, measurement is carried out under the conditions of 25°C and a frequency of 250 kHz. The details of the method for measuring the dielectric constant follow the method described in the examples below.

[0163] <Glass transition temperature of the cured product>

[0164] This cured product preferably has a glass transition temperature (Tg) of 85°C or higher. If the glass transition temperature of the cured product is 85°C or higher, it is possible to suppress the generation of strain in the lower layer when further forming another layer (upper layer) on the layer (lower layer) formed from the curable composition, and thus crack generation can be suppressed. From the viewpoint of suppressing strain generation in the cured product formed from the curable composition, the glass transition temperature of the cured product formed from this composition is more preferably 90°C or higher, further preferably 95°C or higher, still further preferably 98°C or higher, and particularly preferably 100°C or higher. There is no particular limitation on the upper limit of the glass transition temperature of the cured product formed from this composition. The glass transition temperature of the cured product formed from this composition is, for example, 200°C or lower. In addition, the glass transition temperature of the cured product is a value obtained by dynamic viscoelasticity measurement. The details of the method for measuring the glass transition temperature of the cured product follow the method described in the examples below.

[0165] <Gas evolution amount of the cured product>

[0166] When components of the curable composition (specifically, unreacted polymerizable compounds or solvents, etc.) remain in the cured product formed from the curable composition, gas evolution may easily occur from the cured product due to decomposition products of unreacted polymerizable compounds, etc. On the other hand, gas evolution from the cured product may cause deterioration of the device, so it is required to be as little as possible. In this regard, according to this composition, a cured product with a small amount of gas evolution can be obtained. Specifically, it is preferred that when a cured film with a thickness of 8 μm formed from this composition is heated at 110°C for 30 minutes, the gas evolution amount from the cured film is 800 ppm or less. In addition, the gas evolution amount from the cured film is a value measured using the headspace method and a gas chromatograph. The details of the method for measuring the gas evolution amount from the cured film follow the method described in the examples below.

[0167] <Method for manufacturing an organic EL device>

[0168] This cured product and an organic EL device in which an organic light-emitting layer is sealed using this cured product can use this composition and be manufactured by a method including the following steps 1 and 2.

[0169] (Step 1) A step of coating the present composition on the light-emitting layer formation surface of a substrate on which an organic light-emitting layer has been formed

[0170] (Step 2) A step of forming a sealing structure (organic sealing layer) by hardening the present composition by irradiating radiation

[0171] Hereinafter, each step will be described in detail.

[0172] [Step 1: Coating Step]

[0173] In this step, by coating the present composition on the light-emitting layer formation surface of a substrate on which an organic light-emitting layer has been formed, a coating film containing the present composition is formed on the light-emitting layer formation surface. On the substrate coated with the present composition, a laminate including various layers such as an anode layer, a hole injection layer, a hole transport layer, an electron injection layer, and a cathode layer in addition to the organic light-emitting layer is formed, and an organic EL element is constituted by the laminate. The light-emitting layer formation surface coated with the present composition may be covered with an inorganic film (inorganic sealing layer). As the inorganic material constituting the inorganic film, for example, silicon nitride (SiNx) or silicon oxide (SiOx) can be cited. In the above case, a thin film sealing layer including an organic sealing layer and an inorganic sealing layer is formed on the organic light-emitting layer as a sealing structure.

[0174] As a method of coating the present composition, for example, spray coating, roll coating, spin coating, slot die coating, bar coating, inkjet coating, etc. can be cited. In terms of production volume and thinning, inkjet coating among these can be preferably applied. The present composition has a low viscosity, exhibits excellent hardening properties, and the generation of coating unevenness is suppressed, so it can be preferably used for inkjet coating.

[0175] [Step 2: Hardening Step]

[0176] In this step, a hardened film is obtained by irradiating the coating film formed in the step 1 with radiation and hardening the coating film. As the radiation, for example, ultraviolet rays, far ultraviolet rays, visible light, X-rays, charged particle beams such as electron beams, etc. can be cited. Among these, ultraviolet rays are preferred. For example, ultraviolet rays with a wavelength of 350 nm to 400 nm can be preferably used as the irradiation light. As the exposure amount of the radiation, it is preferably 0.05 J / m 2 ~10 J / m 2 . Thus, an organic EL element covered with an organic sealing layer containing the present composition can be obtained. The thickness of the hardened film is usually 0.5 μm to 15 μm.

[0177] The organic sealing layer formed from this composition can also be coated with an inorganic film (inorganic sealing layer). Examples of the inorganic material constituting the inorganic film include silicon nitride (SiNx) and silicon oxide (SiOx). When a thin film sealing layer including an organic sealing layer and an inorganic sealing layer is provided on an organic EL element, the organic sealing layer is formed from this composition, whereby the organic sealing layer can be moderately hardened. Thereby, even when an inorganic sealing layer is further formed on the surface of the organic sealing layer, the occurrence of cracks in the organic sealing layer can be suppressed.

[0178] The organic EL element of the present disclosure manufactured by the method including the above-described step 1 and step 2 includes an organic light-emitting layer and an organic sealing layer containing this composition, and the organic light-emitting layer is sealed with the organic sealing layer. Therefore, in the organic EL element of the present disclosure, the intrusion of moisture into the organic light-emitting layer can be sufficiently suppressed, and thus the occurrence of defects caused by moisture can be suppressed. Specifically, the generation of dark spots or the reduction of light-emitting characteristics such as brightness and luminous efficiency can be suppressed. In addition, in the organic EL element of the present disclosure, the generation of outgassing from the organic sealing layer is small, and furthermore, the dielectric constant of the organic sealing layer is sufficiently low. Such an organic EL element of the present disclosure is useful, for example, as an organic EL lighting device or an organic EL display device.

[0179] By the present disclosure described in detail above, the following means can be provided.

[0180] 〔Means 1〕A curable composition containing a polymerizable compound and a polymerization initiator. In the curable composition, the polymerizable compound includes: a compound (A1) represented by the formula (1); a compound (A2), which is a polyfunctional polymerizable compound (excluding the compound (A1)); and a compound (A3), which is a monofunctional polymerizable compound having one oxetanyl group in one molecule. The total amount of the compound (A1), the compound (A2), and the compound (A3) is 85% by mass or more based on the total amount of the polymerizable compound.

[0181] 〔Means 2〕The curable composition according to 〔Means 1〕, which contains 10% to 60% by mass of the compound (A1), 5% to 70% by mass of the compound (A2), and 20% to 70% by mass of the compound (A3) based on the total amount of the polymerizable compound.

[0182] 〔Means 3〕The curable composition according to 〔Means 1〕 or 〔Means 2〕, wherein the molar ratio of oxiranyl group to oxetanyl group in the polymerizable compound is 1:0.5 to 1:8.

[0183] [Means 4] The curable composition according to any one of [Means 1] to [Means 3], wherein the proportion of the polyfunctional oxetane compound in the compound (A2) is 30% by mass or more.

[0184] [Means 5] The curable composition according to any one of [Means 1] to [Means 4], wherein the compound (A1) is represented by the formula (1-1).

[0185] [Means 6] The curable composition according to [Means 5], wherein R 3 and R 4 are methyl groups.

[0186] [Means 7] The curable composition according to any one of [Means 1] to [Means 6], wherein the content of the monofunctional oxirane compound formed by bonding a monovalent chain group to an oxiranyl group is 10% by mass or less of the whole composition.

[0187] [Means 8] The curable composition according to any one of [Means 1] to [Means 7], wherein the dielectric constant of the cured product of the curable composition at 25 °C and a frequency of 250 kHz is 2.70 or less.

[0188] [Means 9] The curable composition according to any one of [Means 1] to [Means 8], wherein the glass transition temperature of the cured product of the curable composition is 85 °C or higher.

[0189] [Means 10] The curable composition according to any one of [Means 1] to [Means 9], for inkjet coating.

[0190] [Means 11] The curable composition according to any one of [Means 1] to [Means 10], for forming a sealing structure for sealing an organic light-emitting layer of an organic EL element.

[0191] [Means 12] A curable composition containing a polymerizable compound and a polymerization initiator. In the curable composition, the polymerizable compound includes: the compound represented by the formula (1); a compound that is a polyfunctional polymerizable compound (wherein the compound represented by the formula (1) is excluded); and a compound that is a monofunctional polymerizable compound. The dielectric constant of the cured product of the curable composition at 25 °C and a frequency of 250 kHz is 2.70 or less, and the glass transition temperature of the cured product is 85 °C or higher.

[0192] [Means 13] A cured film formed using the curable composition according to any one of [Means 1] to [Means 12].

[0193] [Means 14] An organic EL element, comprising: an organic light-emitting layer and an organic sealing layer for sealing the organic light-emitting layer, and the organic sealing layer is formed using the curable composition according to any one of [Means 1] to [Means 12].

[0194] [Means 15] A method for manufacturing an organic EL element, which manufactures an organic EL element including an organic light-emitting layer and an organic sealing layer for sealing the organic light-emitting layer, the manufacturing method including: a step of coating the light-emitting layer formation surface of a substrate on which the organic light-emitting layer has been formed with the curable composition according to any one of [Means 1] to [Means 12]; and a step of forming the organic sealing layer by hardening the curable composition by irradiating radiation.

[0195] [Means 16] The method for manufacturing an organic EL element according to [Means 15], wherein the curable composition is coated by inkjet coating.

[0196] [Examples]

[0197] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples. In addition, "parts" and "%" in the examples and comparative examples are based on mass unless otherwise specified.

[0198] 1. Preparation of curable composition

[0199] The components used in the preparation of the curable composition are as described below.

[0200] 〈Polymerizable compound〉

[0201] · Polyfunctional compound

[0202] A1-1: The compound described in formula (5) of

[0106] in Korean Patent Publication No. 10-2022-0160362

[0203] A2-1: OXT-221 (3,3'-(oxybis(methylene))bis(3-ethyloxetane), manufactured by Toagosei Co., Ltd.)

[0204] A2-2: Celloxide 2021P (manufactured by Daicel Corporation)

[0205] A2-3: Celloxide 8010 (manufactured by Daicel Corporation)

[0206] A2-4: KR-470 (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0207] A2-5: X-40-2669 (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0208] A2-6: X-40-2678 (manufactured by Shin-Etsu Chemical Co., Ltd.)

[0209] · Monofunctional compound

[0210] A3-1: OXT-212 (3-ethyl-3-[(2-ethylhexyloxy)methyl]oxetane, manufactured by Toagosei Co., Ltd.)

[0211] A3-2: 1,2-epoxytetradecane (manufactured by Yokkaichi Synthesis Co., Ltd.)

[0212] 〈Polymerization initiator〉

[0213] B-1: Photo cationic polymerization initiator ("CPI-210S" manufactured by San-apro Co., Ltd.)

[0214] 〈Sensitizer〉

[0215] C-1: 9,10-dibutoxyanthracene

[0216] 〈Surfactant〉

[0217] D-1: Silicone-containing nonionic surfactant ("BYK-333" manufactured by BYK-Chemie Japan Co., Ltd.)

[0218] [Example 1]

[0219] In an atmospheric environment, 50 parts by mass of compound (A1-1), 10 parts by mass of compound (A2-1), 40 parts by mass of compound (A3-1), 3 parts by mass of polymerization initiator (B-1), 1 part by mass of sensitizer (C-1), and 1 part by mass of surfactant (D-1) were mixed to prepare a curable composition.

[0220] [Examples 2 to 6 and Comparative Examples 1 to 6]

[0221] The types and amounts of the polymerizable compounds were changed as described in Table 1, and a curable composition was prepared in the same manner as in Example 1 except for this.

[0222] In addition, in Table 1, the numerical value in the column of "oxiranyl / oxetanyl [mol / mol]" represents the molar ratio of oxiranyl to oxetanyl in the polymerizable compounds used in the preparation of each curable composition. The molar ratio is calculated based on the blending composition of the polymerizable compounds.

[0223] 2. Evaluation

[0224] For the curable compositions of Example 1 to Example 6 and Comparative Example 1 to Comparative Example 6, the following items were evaluated by the methods described below. The evaluation results are shown in Table 1.

[0225] <Dielectric Constant of the Hardened Film>

[0226] On a substrate obtained by vapor-depositing indium tin oxide (ITO) with a thickness of 30 nm on an alkali-free glass, a curable composition was coated using a spin coater so that the hardened thickness became 8 μm. Next, ultraviolet light with a wavelength of 395 nm was irradiated using an LED UV lamp with an illuminance of 1000 mW / cm 2 and an accumulated light quantity of 1,000 mJ / cm 2 to cure the curable composition and form a hardened film. As the LED UV lamp, UniJet E110Z HD (model U395A-455, manufactured by USHIO Electric Inc.) was used. Thereafter, aluminum was vapor-deposited on the surface of the hardened film with a thickness of 50 nm to produce a test piece for dielectric constant measurement. For the obtained test piece, the dielectric constant was measured using a dielectric constant measuring device at 25 °C and 250 KHz. As the dielectric constant measuring device, an HP 4284A inductance-capacitance-resistance meter (LCR meter) (manufactured by HEWLETT PACKARD) was used.

[0227] <Glass Transition Temperature (Tg) of the Hardened Film>

[0228] On a 95 mm square glass substrate after demolding treatment, a curable composition was coated by spin coating. Subsequently, ultraviolet light with a wavelength of 395 nm was irradiated using an LED lamp under nitrogen to cure the curable composition and form a hardened film. The hardened film formed on the glass substrate was peeled off from the substrate to obtain a hardened film with a thickness of 60 μm. For the obtained hardened film, the glass transition temperature of the hardened film was measured by measuring the peak of Tanδ using a dynamic viscoelasticity measuring device ("DVA-225" manufactured by IT Measurement & Control Co., Ltd.).

[0229] <Amount of Outgassing>

[0230] The amount of gas (outgassing) generated when heating the hardened film of the curable composition was measured using a gas chromatograph based on the headspace method. The measurement was carried out in the following order. First, the curable composition was coated to a thickness of 8 μm using a spin coater. Subsequently, using an LED lamp with an illuminance of 1,000 mW / cm 2 and an accumulated light quantity of 1,000 mJ / cm 2Irradiate it with ultraviolet light having a wavelength of 395 nm under the specified conditions to harden it. Then, place the hardened film in a vial in the headspace, seal the vial, and heat it at 110 °C for 30 minutes. Measure the outgassing amount by the headspace method.

[0231] 〇: The outgassing amount is 300 ppm or more and less than 800 ppm

[0232] ×: The outgassing amount is 800 ppm or more

[0233]

[0234] As shown in Table 1, regarding the hardened films formed from the curable compositions of Examples 1 to 6, the glass transition temperature is high, 85 °C or higher, the dielectric constant is lower than 2.70, and the amount of outgassing generated is small. Among these, regarding the hardened films formed from the curable compositions containing 20% by mass or more of the compound (A1-1) relative to the total amount of the polymerizable compounds, the glass transition temperature is high, 100 °C or higher, and the dielectric constant is lower than 2.65, and the high Tg and low dielectric constant of the hardened film can be sufficiently achieved (Examples 1 to 4). In addition, regarding the hardened films formed from the curable compositions in which the total amount of the compound (A1) and the compound (A2) is 70% by mass or more relative to the total amount of the polymerizable compounds, the glass transition temperature is high, 100 °C or higher, and the dielectric constant is low, 2.65, and the high Tg and low dielectric constant of the hardened film can also be sufficiently achieved (Example 6).

[0235] In contrast, regarding the hardened films formed from the curable compositions of Comparative Example 1 and Comparative Example 2, the glass transition temperature is sufficiently high. On the other hand, the dielectric constant is higher than 2.70. In addition, regarding the hardened film formed from the curable composition of Comparative Example 3, the glass transition temperature is low, 79 °C, and the dielectric constant is also high, 2.72. Regarding the hardened films formed from the curable compositions of Comparative Examples 4 to 6, the dielectric constant is lower than 2.70. On the other hand, the glass transition temperature is lower than 80 °C. Regarding Comparative Example 6, the amount of outgassing of the hardened film is also large.

Claims

1. A curable composition comprising a polymerizable compound and a polymerization initiator, wherein: The polymerizable compound comprises: Compound (A1) is represented by the following formula (1): R 1 -X 1 -R 2 …(1) In formula (1), R 1 and R 2 are independently substituted or unsubstituted alicyclic oxirane; X 1 is a divalent hydrocarbon group or a halogenated hydrocarbon group; Compound (A2) is a polyfunctional polymerizable compound excluding the compound (A1); and Compound (A3) is a monofunctional polymerizable compound having one oxetane group in one molecule, The total amount of the compound (A1), the compound (A2) and the compound (A3) is 85% by mass or more based on the total amount of the polymerizable compound.

2. The curable composition according to claim 1, comprising 10% to 60% by mass of the compound (A1), 5% to 70% by mass of the compound (A2), and 20% to 70% by mass of the compound (A3), based on the total amount of the polymerizable compound. 3 . The curable composition according to claim 1 , wherein a molar ratio of the oxirane group to the oxetane group in the polymerizable compound is 1:0.5 to 1:

8. 4 . The curable composition according to claim 1 , wherein the ratio of the polyfunctional oxetane compound in the compound (A2) is 30% by mass or more.

5. The curable composition according to claim 1, wherein the compound (A1) is represented by the following formula (1-1): In formula (1-1), R 3 and R 4 are independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, a fluoroalkyl group having 1 to 3 carbon atoms, or a phenyl group, or R 3 and R 4 Combined with R 3 and R 4 The carbon atoms bonded together form an alicyclic structure; R 5 and R 6 They are each independently an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 20 carbon atoms; and n1 and n2 are each independently an integer of 0 to 3.

6. The curable composition according to claim 5, wherein R in the formula (1-1) 3 and R 4 It is methyl. 7 . The curable composition according to claim 1 , wherein the content of the monofunctional oxirane compound formed by bonding a monovalent chain group to an oxirane group is 10% by mass or less of the entire composition. 8 . The curable composition according to claim 1 , wherein a cured product of the curable composition has a dielectric constant of 2.70 or less at 25° C. and a frequency of 250 kHz. 9 . The curable composition according to claim 1 , wherein a cured product of the curable composition has a glass transition temperature of 85° C. or higher.

10. The curable composition according to claim 1, which is used for inkjet coating. 11 . The curable composition according to claim 1 , which is used to form a sealing structure for sealing an organic light-emitting layer of an organic electroluminescent element.

12. A curable composition comprising a polymerizable compound and a polymerization initiator, wherein: The polymerizable compound comprises: A compound represented by the following formula (1): R 1 -X 1 -R 2 …(1) In formula (1), R 1 and R 2 are independently substituted or unsubstituted alicyclic oxirane; X 1 is a divalent hydrocarbon group or a halogenated hydrocarbon group; a polyfunctional polymerizable compound excluding the compound represented by the formula (1); and Monofunctional polymerizable compounds, The cured product of the curable composition has a dielectric constant of 2.70 or less at 25° C. and a frequency of 250 kHz. The glass transition temperature of the cured product is 85° C. or higher. 13 . A cured film formed using the curable composition according to claim 1 .

14. An organic electroluminescent element, comprising: an organic light emitting layer, and an organic sealing layer for sealing the organic light emitting layer, and The organic sealing layer is formed using the curable composition according to any one of claims 1 to 12.

15. A method for manufacturing an organic electroluminescent element, comprising manufacturing an organic electroluminescent element comprising an organic light-emitting layer and an organic sealing layer for sealing the organic light-emitting layer, The manufacturing method comprises: A step of applying the curable composition according to any one of claims 1 to 12 onto the light-emitting layer-forming surface of the substrate on which the organic light-emitting layer is formed; as well as A step of curing the curable composition by irradiating radiation to form the organic sealing layer. 16 . The method for producing an organic electroluminescent element according to claim 15 , wherein the curable composition is applied by inkjet coating.

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