Curable composition, cured film, organic electroluminescent element, and method for producing organic electroluminescent element

Abstract

The present application provides a curable composition, a cured film, an organic electroluminescent element, and a method for producing an organic electroluminescent element, which exhibits excellent curability while being low in viscosity, and which can provide a cured film exhibiting a high refractive index and improved element reliability. A curable composition is produced, comprising: [A1] a compound having an ethylenically unsaturated group and at least one group [F1] selected from the group consisting of a group represented by formula (1), -S(=O)-, and -S(=O)2-, the group [F1] having a partial structure adjacent to a carbon-carbon unsaturated bond in the ethylenically unsaturated group; [A2] a compound having an ethylenically unsaturated group and a thioether group, the thioether group having a partial structure adjacent to a carbon-carbon unsaturated bond in the ethylenically unsaturated group; and [B] a radical polymerization initiator. In formula (1), X 1 is an oxygen atom, a sulfur atom, or a selenium atom.

Description

Technical Field

[0001] This invention relates to a curable composition, a curable film, an organic EL element, and a method for manufacturing an organic EL element. Background Technology

[0002] Organic electroluminescent (OLED) devices are light-emitting devices with a stacked structure comprising an anode, an organic light-emitting layer, and a cathode. OLED devices are widely used in various applications, including display devices and lighting devices.

[0003] The organic light-emitting layer included in organic EL elements is prone to degradation due to contact with moisture or oxygen. For example, there are concerns that prolonged operation may lead to the formation of localized non-luminescent areas (hereinafter also referred to as "dark spots") caused by moisture seeping into the element, or that contact with moisture or oxygen may result in a decrease in luminescence characteristics. Therefore, a sealing structure has previously been provided on organic EL elements to prevent the organic light-emitting layer from contacting moisture or oxygen (see, for example, Patent Documents 1 and 2). Patent Documents 1 and 2 disclose the formation of an organic sealing layer covering the organic light-emitting layer using a curable composition comprising organic materials.

[0004] [Existing technical documents]

[0005] [Patent Literature]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2020-26515

[0007] [Patent Document 2] International Publication No. 2021 / 010226 Summary of the Invention

[0008] [The problem the invention aims to solve]

[0009] In forming the sealing structure of an organic EL element, it is ideal to form a hardened film without heat treatment to minimize damage to the element. Therefore, it is considered that the sealing structure of the organic EL element is formed by curing it using radiation irradiation. In this case, the curing composition is required to obtain a highly reliable element with high sensitivity to radiation and sufficient suppression of moisture or oxygen penetration into the element's interior. Furthermore, from the viewpoint of improving the light extraction efficiency of the organic EL element, it is also required that the hardened film obtained from the curing composition exhibits a high refractive index.

[0010] Furthermore, due to the ease of forming a homogeneous coating film with a small amount of curing composition and its excellent yield, inkjet coating has been used in recent years to coat the curing composition onto a substrate to form a curing film. For inkjet coating to be applicable when forming a sealing structure, the curing composition must have a low viscosity.

[0011] The present invention was made in view of the aforementioned issues, and its main objective is to provide a curable composition that exhibits excellent curability while having low viscosity, and can obtain a curable film that exhibits high refractive index and improves component reliability.

[0012] [Technical means to solve the problem]

[0013] The inventors of this invention focus on forming a hardened film through free radical copolymerization of an electron donor monomer and an electron acceptor monomer. Furthermore, they have discovered that the aforementioned problem can be solved by preparing a hardened composition comprising at least two polymerizable compounds having specific structures. Specifically, according to the present invention, a hardened composition, a hardened film, an organic EL element, and a method for manufacturing an organic EL element are provided.

[0014] [1] A hardening composition comprising:

[0015] [A1] Compound, having an ethylene unsaturated group, and selected from the following formula (1)

[0016] [Chemistry 1]

[0017]

[0018] (In formula (1), X) 1 It consists of an oxygen atom, a sulfur atom, or a selenium atom. (* indicates a bond.)

[0019] At least one group [F1] from the group consisting of the indicated group, -S(=O)- and -S(=O)2-, said group [F1] having a partial structure adjacent to the carbon-carbon unsaturated bond in the vinyl unsaturated group;

[0020] [A2] Compound, having an ethylene unsaturated group and a thioether group, wherein the thioether group has a partial structure adjacent to the carbon-carbon unsaturated bond in the ethylene unsaturated group; and

[0021] [B] Free radical polymerization initiator.

[0022] [2] A hardening film formed from the hardening composition according to [1].

[0023] [3] An organic EL element wherein the light-emitting layer is sealed by a hardened film according to [2].

[0024] [4] A method for manufacturing an organic EL element includes the following steps: coating a curable composition according to [1] onto the light-emitting layer forming surface of a substrate on which an organic light-emitting layer is formed, irradiating it with radiation and curing the curable composition, thereby forming a sealed structure.

[0025] [The effects of the invention]

[0026] The curable composition of the present invention exhibits excellent curability while maintaining low viscosity. Furthermore, the curable composition according to the present invention can yield a cured film exhibiting a high refractive index and improved component reliability. Detailed Implementation

[0027] The following provides a detailed description of matters related to the implementation method. Furthermore, in this specification, the numerical range indicated by “~” refers to the values ​​before and after the “~” as the lower and upper limits.

[0028] Hardening Compositions

[0029] The curable composition disclosed herein (hereinafter also referred to as "the composition") contains a [A1] compound, a [A2] compound, and a [B] free radical polymerization initiator. A curable film is obtained by free radical copolymerization of the [A1] compound and the [A2] compound through irradiation of the composition. The composition is effectively used as a sealant for thin-film encapsulation (TFE) of organic electroluminescent elements (organic EL elements). The components contained in the composition, and other components formulated as needed, are described below. Furthermore, unless otherwise specifically mentioned, each component may be used alone or in combination of two or more.

[0030] In this specification, "hydrocarbon group" refers to a group comprising chain-like hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. "Chain-like hydrocarbon group" refers to a straight-chain hydrocarbon group or branched hydrocarbon group that consists only of chain-like structures and does not contain cyclic structures in its main chain. These can be saturated or unsaturated. "Alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic hydrocarbon structure as its ring structure and does not contain an aromatic ring structure. This group does not necessarily need to consist solely of an alicyclic hydrocarbon structure and may also include a group with a chain structure in a portion thereof. "Aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as its ring structure. This group does not necessarily need to consist solely of an aromatic ring structure and may also include a chain structure or an alicyclic hydrocarbon structure in a portion thereof. Furthermore, the ring structure of alicyclic hydrocarbon groups and aromatic hydrocarbon groups may also have substituents containing hydrocarbon structures. "Cyclic hydrocarbon group" refers to a group comprising alicyclic hydrocarbon groups and aromatic hydrocarbon groups. "Structural unit" refers to a unit that mainly constitutes the main chain structure and contains at least two or more units in the main chain structure.

[0031] <[A1] compound>

[0032] [A1] The compound is a photopolymerizable compound having an ethylene unsaturated group and at least one group selected from the group consisting of -S(=O)- and -S(=O)2- [F1].

[0033] [Chemistry 2]

[0034]

[0035] (In formula (1), X) 1 It consists of an oxygen atom, a sulfur atom, or a selenium atom. (* indicates a bond.)

[0036] As an ethylene unsaturated group present in [A1] compounds, examples include groups having -CH=CR- (where R is a hydrogen atom or a monovalent hydrocarbon group). In [A1] compounds, at least one of the two carbon atoms constituting a carbon-carbon unsaturated bond is bonded with the group [F1].

[0037] The number of vinyl unsaturated groups in one molecule of the [A1] compound is not particularly limited. From the viewpoint of improving the sensitivity of the composition and suppressing the generation of gas escape from the self-curing film, the number of vinyl unsaturated groups in the [A1] compound is preferably two or more. In addition, from the viewpoint of obtaining a curing composition with sufficiently low viscosity, the number of vinyl unsaturated groups in the [A1] compound is preferably 10 or less, more preferably 6 or less, and even more preferably 4 or less.

[0038] Regarding the basis [F1], from the perspective of ease of acquisition, X in equation (1) 1 Oxygen atoms or sulfur atoms are preferred. There is no particular limitation on the number of [F1] groups present in one molecule of the [Al] compound, as long as there is one or more. From the viewpoint of suppressing the generation of gas escape in the hardened film, the number of [F1] groups present in one molecule of the [Al] compound is, for example, 10 or less. From the viewpoint of hardening properties, the [F1] group is preferably the group represented by formula (1) or -S(=O)-, and from the viewpoint of obtaining a hardened film with a high refractive index, the group represented by formula (1) is more preferred.

[0039] In the [A1] compound, the [F1] group has a partial structure adjacent to the carbon atom constituting the carbon-carbon unsaturated bond in the vinyl unsaturated group. Specifically, the [A1] compound is preferably at least one of the group consisting of the partial structures represented by formula (2-1) and the partial structures represented by formula (2-2).

[0040] [Chemistry 3]

[0041]

[0042] (In equations (2-1) and (2-2), R) 1 It is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms. X 1 It can be an oxygen atom, a sulfur atom, or a selenium atom. Y 1 It can be -S(=O)- or -S(=O)2-. (* indicates a bond)

[0043] In equations (2-1) and (2-2), R is used as... 1 Examples of halogen atoms that can be represented include: fluorine, chlorine, bromine, and iodine atoms. R 1 The alkyl group representing 1 to 6 carbon atoms can be either straight-chain or branched. As R 1 Specific examples of alkyl groups having 1 to 6 carbon atoms include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc. From the viewpoint of further improving the curability of this composition, wherein R... 1 Preferably, it is a hydrogen atom, a halogen atom, or a methyl group, and more preferably a hydrogen atom.

[0044] As the [A1] compound, at least one of the compounds selected from the group consisting of the compounds represented by formula (3-1) and the compounds represented by formula (3-2) can preferably be used.

[0045] [Chemistry 4]

[0046]

[0047] (In equation (3-1), R) 2 It is a monovalent organogroup with 1 to 20 carbon atoms. r is an integer from 1 to 3. When r is 2 or 3, multiple R... 1 Whether they are the same or different, when r is 1, multiple R 2 Same or different. R 1 and X 1 It has the same meaning as equation (2-1).

[0048] In equation (3-2), R 3 It is an organogroup with 1 to 20 carbon atoms and a valence of t. t is an integer from 1 to 4. When t is 2 or higher, multiple R... 1 Same or different, multiple Y 1 Same or different. R 1 and Y 1 (Same meaning as equation (2-2))

[0049] In equation (3-1), R is used as 2The monovalent organic groups representing carbon 1 to 20 can be listed as: monovalent hydrocarbon groups with carbon 1 to 20, and those with the formula "-OR". 4 The base and formula "-SR" are represented by " 4 The basis represented by "R" (where R is the base) 4 (e.g., monovalent hydrocarbon groups with 1 to 20 carbon atoms). As R... 2 and R 4 Examples of monovalent hydrocarbon groups with 1 to 20 carbon atoms include: straight-chain or branched alkyl groups with 1 to 20 carbon atoms, monovalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms, and monovalent aromatic hydrocarbon groups with 6 to 20 carbon atoms.

[0050] Specific examples of alkyl groups having 1 to 20 carbon atoms include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, 3-pentyl, tert-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-decyl, etc. Among these, linear or branched alkyl groups having 1 to 10 carbon atoms are preferred, and linear or branched alkyl groups having 1 to 5 carbon atoms are more preferred.

[0051] Specific examples of monovalent alicyclic hydrocarbon groups with 3 to 20 carbon atoms include: cyclopentyl, cyclohexyl, methylcyclohexyl, cycloheptyl, cyclooctyl, etc.

[0052] Examples of monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include aryl groups having 6 to 20 carbon atoms and aralkyl groups having 7 to 20 carbon atoms. Specific examples of aryl groups having 6 to 20 carbon atoms include: phenyl, methylphenyl, ethylphenyl, dimethylphenyl, diethylphenyl, trimethylphenyl, naphthyl, anthraceneyl, etc. Specific examples of aralkyl groups having 7 to 20 carbon atoms include: benzyl, phenethyl, naphthylmethyl, anthracenemethyl, etc.

[0053] Of these, R 2 and R 4 The monovalent hydrocarbon group represented by carbon 1 to 20 is preferably an alkyl group with carbon 1 to 10 and a monovalent aromatic hydrocarbon group with carbon 6 to 12, and more preferably an alkyl group with carbon 1 to 5, a phenyl group and a naphthyl group.

[0054] In formula (3-2), the organic groups with t valences having 1 to 20 carbon atoms represented by R3 can be listed as: chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups with t valences having 1 to 20 carbon atoms. Specific examples of these can be listed from those represented by R... 2 The radicals represented by monovalent hydrocarbon groups with 1 to 20 carbon atoms are formed by removing (t-1) hydrogen atoms from the radicals. Furthermore, in R... 3 In the case of a chain hydrocarbon group with 1 to 20 carbon atoms and a valence of t, the chain hydrocarbon group represented by R3 can be either saturated or unsaturated. As R... 3Specific examples of unsaturated chain hydrocarbon groups can be exemplified by groups formed by removing t hydrogen atoms from alkenes with 2 to 20 carbon atoms.

[0055] In equation (3-1), r is an integer from 1 to 3, preferably 2 or 3. In equation (3-2), t is an integer from 1 to 4, preferably 1 to 3, more preferably 1 or 2.

[0056] Furthermore, in equation (3-2) R 3 In the case of having vinyl unsaturated groups, the number of vinyl unsaturated groups in one molecule of the [A1] compound is called R. 3 The total number of vinyl unsaturated groups and t. Similarly, in equation (3-1), R... 2 In the case of having vinyl unsaturated groups, the number of vinyl unsaturated groups in one molecule of the [A1] compound is called R. 2 The total number of vinyl unsaturated groups and r. Where R 2 Preferably, it does not have an ethylene-like unsaturated group.

[0057] Specific examples of compounds with [A1] as represented by formula (3-1) include: dimethyl vinyl phosphate, diethyl vinyl phosphate, ethyl vinyl phosphate, methyl phenyl vinyl phosphate, diphenyl vinyl phosphate, methyl divinylphosphine oxide, ethyl divinylphosphine oxide, phenyl divinylphosphine oxide, phenyl divinylphosphine sulfide, trivinylphosphine oxide, trivinylphosphine sulfide, diphenyl vinylphosphine sulfide, trivinylphosphine selenide, diphenyl vinylphosphine selenide, phenyl divinylphosphine selenide, methyl divinylphosphine selenide, etc.

[0058] Examples of compounds represented by formula (3-2) include: bis(vinylsulfonyl)methane, bis(vinylsulfonyl)ethane, bis(vinylsulfonyl)propane, divinyl sulfone, vinylphenyl sulfoxide, divinyl sulfoxide, phenylvinyl sulfone, etc.

[0059] As a [A1] compound, from the viewpoint of the curability of the composition and the refractive index of the obtained cured film, the compound represented by formula (3-1) may preferably be used.

[0060] In this composition, the content of [A1] compound is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, relative to 100 parts by mass of the polymeric compounds contained in the composition. Furthermore, the content of [A1] compound is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, relative to 100 parts by mass of the polymeric compounds contained in the composition. If the content of [A1] compound is within the aforementioned range, it is preferable in terms of obtaining a curable composition with an excellent balance between low viscosity and curability, and in terms of producing a highly reliable organic EL element when using this composition to form a curable film constituting an organic EL element.

[0061] Furthermore, "polymerizable compound" is a compound that can react with a stimulus to form a polymer. In this specification, the [A1] compound and [A2] compound contained in this composition, as well as any compound that can copolymerize with the [A1] compound and [A2] compound (i.e., the [A3] compound described below) that is arbitrarily incorporated into this composition, are equivalent to "polymerizable compounds".

[0062] <[A2] compound>

[0063] [A2] The compound is a photopolymerizable thioether compound having an ethylene unsaturated group and a thioether group (-S-), wherein the thioether group has a partial structure adjacent to the carbon-carbon unsaturated bond in the ethylene unsaturated group (hereinafter also referred to as "specific thioether structure").

[0064] As an ethylene unsaturated group contained in a specific thioether structure, groups having -CH=CR- (where R is a hydrogen atom or a monovalent hydrocarbon group) can be listed. In a specific thioether structure, a sulfur atom is bonded to at least one of the two carbon atoms constituting a carbon-carbon unsaturated bond. [A2] The ethylene unsaturated group in the compound is preferably R. 11 -CH = CH- (where R...) 11 (It is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms).

[0065] From the viewpoint of improving the sensitivity of this composition and suppressing the generation of gas from the self-curing film, the number of vinyl unsaturated groups in one molecule of the [A2] compound is preferably two or more. Furthermore, from the viewpoint of obtaining a curing composition with sufficiently low viscosity, the number of vinyl unsaturated groups in the [A2] compound is preferably 10 or less, more preferably 6 or less, and even more preferably 4 or less.

[0066] [A2] The compound is not particularly limited as long as it has one or more specific thioether structures within a molecule. From the viewpoint of achieving a high refractive index of the hardened film formed using this composition, the [A2] compound is preferably a partial structure having an aromatic ring and having a sulfur atom (i.e., the sulfur atom in the specific thioether structure) adjacent to the carbon atom constituting the vinyl unsaturated bond bond bonded to the aromatic ring.

[0067] When the [A2] compound has an aromatic ring, aromatic hydrocarbon rings and aromatic heterocycles can be listed as aromatic rings. Specific examples of these include: as aromatic hydrocarbon rings, benzene rings, naphthalene rings, anthracene rings, etc. As aromatic heterocycles, as nitrogen-containing aromatic heterocycles, pyridine rings, pyrazine rings, pyrimidine rings, pyridazine rings, 1,3,5-triazine rings, and imidazole rings, etc.; as oxygen-containing aromatic heterocycles, furan rings and oxazole rings, etc.; as sulfur-containing aromatic heterocycles, thiophene rings, thiazole rings, and 1,3,4-thiadiazole rings, etc. The aromatic rings possessed by the [A2] compound are particularly preferably benzene rings, naphthalene rings, 1,3,5-triazine rings, and 1,3,4-thiadiazole rings among these.

[0068] [A2] The compound is preferably the compound represented by the following formula (5).

[0069] [Chemistry 5]

[0070]

[0071] (In equation (5), R) 11 It is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms. Ar 1 It is a u-valent group with an aromatic ring. Among them, R constitutes... 11 The sulfur atom of -CH=CH-S- reacts with Ar 1 Aromatic ring bonds in. u is an integer from 1 to 10. When u is 2 or higher, multiple R... 11 (Same or different)

[0072] In equation (5), R is used as 11 Examples of halogen atoms that can be represented include: fluorine, chlorine, bromine, and iodine atoms. R 11 The alkyl group representing 1 to 6 carbon atoms can be either straight-chain or branched. As R 11 Specific examples of alkyl groups having 1 to 6 carbon atoms include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, etc. From the viewpoint of further improving the curability of this composition, R 11 Preferably, it is a hydrogen atom, a halogen atom, or a methyl group, and more preferably a hydrogen atom.

[0073] As Ar 1The aromatic rings possessed can be listed as those exemplified in the description of aromatic rings that compounds [A2] may possess. Among them, Ar... 1 Preferably, it is a base obtained by removing u hydrogen atoms from the ring portion of the structure represented by any one of the following formulas (6-1) to (6-5).

[0074] [Chemistry 6]

[0075]

[0076] (In equations (6-1) to (6-3), R) 12 and R 13 Each of the following is an independent halogen atom or an alkyl group having 1 to 6 carbon atoms. a1 and a2 are independent integers from 0 to 4. a3 is an integer from 0 to 5. a4 is an integer from 0 to 7. Multiple Rs exist in the formula. 12 In the case of multiple R 12 Whether the R values ​​are the same or different, there are multiple R values ​​in the formula. 13 In the case of multiple R 13 (Same or different)

[0077] In equations (6-1) to (6-3), regarding R 12 and R 13 The halogen atoms and alkyl groups having 1 to 6 carbon atoms represented can be respectively applied using R 11 Explanation of the halogen atoms and alkyl groups having 1 to 6 carbon atoms. R 12 and R 13 Preferably, it is an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group. a1 and a2 are preferably 0 to 2.

[0078] Among them, as the [A2] compound, at least one of the compounds selected from the group consisting of the compound represented by formula (7-1), the compound represented by formula (7-2), the compound represented by formula (7-3), the compound represented by formula (7-4), and the compound represented by formula (7-5) can preferably be used.

[0079] [Chemistry 7]

[0080]

[0081] (In equations (7-1) to (7-5), R) 14 R 15 and R 16 Each of the following is an independent hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms. a5 is an integer from 0 to 5. a6 is an integer from 0 to 7. Among these, a3 + a5 ≤ 5 and a4 + a6 ≤ 7 are satisfied. Multiple R's exist in the formula. 15 In the case of multiple R 15 Same or different. R12 R 13 a1, a2, a3, and a4 have the same meaning as equations (6-1) to (6-3), respectively.

[0082] Examples of [A2] compounds include: bis(4-vinylthiophenyl) sulfide, bis(3-methyl-4-vinylthiophenyl) sulfide, bis(3,5-dimethyl-4-vinylthiophenyl) sulfide, 1,3-bis(vinylthiophenyl)benzene, 1,5-bis(vinylthiophenyl)naphthalene, 2,6-bis(vinylthiophenyl)naphthalene, 2,5-divinylthio-1,3,4-thiadiazole, 2,4,6-trivinylthio-1,3,5-triazine, etc.

[0083] In this composition, the content of compound [A2] is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, relative to the total mass of 100 parts by mass of the polymerizable compounds contained in the composition. Furthermore, the content of compound [A2] is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 80 parts by mass or less, relative to the total mass of 100 parts by mass of the polymerizable compounds contained in the composition.

[0084] The ratio of [A1] compound to [A2] compound in this composition is preferably set based on the total number of vinyl unsaturated groups (NA) of the [A1] compound and the total number of vinyl unsaturated groups (NB) of the [A2] compound contained in this composition. Specifically, it is preferable to set the amount of [A1] compound and [A2] compound in this composition such that the molar ratio of NA to NB is (NA):(NB) = 1:0.5 to 1:1.5. By formulating [A1] compound and [A2] compound in such a range as the ratio of NA to NB, it is preferable to improve the sensitivity of this composition and obtain a composition with excellent curing properties, as well as to suppress the escaping of the cured film. From this point of view, (NA):(NB) is more preferably 1:0.7 to 1:1.3, and even more preferably 1:0.8 to 1:1.2.

[0085] <[B] Free Radical Polymerization Initiators>

[0086] The preferred free radical polymerization initiator is a photoradioactive initiator that can generate free radicals in response to radiation and initiate polymerization. There are no particular limitations on the free radical polymerization initiator used; examples include: O-acyl oxime compounds, acetophenone compounds, biimidazole compounds, and acylphosphine oxide compounds.

[0087] Examples of O-acyl oxime compounds include: 1,2-octanedione 1-[4-(phenylthio)-2-(O-benzoyl oxime)], acetone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyl oxime), 1-(9-ethyl-6-benzoyl-9H-carbazole-3-yl)-octan-1-one oxime-O-acetate, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-ethane-1-one oxime-O-benzoate, 1-[9-n-butyl-6-(2-ethylbenzoyl)-9H-carbazole-3-yl]-ethane-1-one oxime-O-benzoate, acetone-1-[9-ethyl-6-(2-methyl ... Examples of acetones include: [9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyl oxime), acetone-1-[9-ethyl-6-(2-methyl-5-tetrahydrofuranylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyl oxime), acetone-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-ditetrahydrofuranyl(oxolanyl))methoxybenzoyl}-9H-carbazole-3-yl]-1-(O-acetyl oxime), etc. O-acyl oxime compounds may preferably use polymerization initiators having a carbazole skeleton in the molecule (e.g., acetone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyl oxime), etc.).

[0088] Examples of acetophenone compounds include, for example, α-aminoketone compounds and α-hydroxyketone compounds. Specific examples of these include, for α-aminoketone compounds, 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butane-1-one, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butane-1-one, and 2-methyl-1-(4-methylthiophenyl)-2-morpholinylpropane-1-one. Examples of α-hydroxyketone compounds include 1-phenyl-2-hydroxy-2-methylpropane-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl)one, and 1-hydroxycyclohexylphenyl ketone.

[0089] Examples of biimidazole compounds include 2,2′-bis(2-chlorophenyl)-4,4′,5,5′-tetraphenyl-1,2′-biimidazole, 2,2′-bis(2,4-dichlorophenyl)-4,4′,5,5′-tetraphenyl-1,2′-biimidazole, or 2,2′-bis(2,4,6-trichlorophenyl)-4,4′,5,5′-tetraphenyl-1,2′-biimidazole, etc.

[0090] Examples of acylphosphine oxide compounds include 2,4,6-trimethylbenzoyl-diphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0091] Relative to 100 parts by mass of the polymerizable compounds contained in this composition, the content of the free radical polymerization initiator in this composition is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more. Furthermore, relative to 100 parts by mass of the polymerizable compounds contained in this composition, the content of the free radical polymerization initiator is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less. By setting the content of the free radical polymerization initiator within the aforementioned range, good curing properties, etc., can be achieved.

[0092] <Other Ingredients>

[0093] In addition to the aforementioned [A1] compound, [A2] compound, and [B] radical polymerization initiator, this composition may also contain components different from the [A1] compound, [A2] compound, and [B] radical polymerization initiator (hereinafter also referred to as "other components"). Examples of other components include, for example, [A3] compound, [C] polymerization inhibitor, and [D] surfactant.

[0094] Compound [A3]

[0095] Compound [A3] is a component capable of copolymerizing with compounds [A1] and [A2], and is a compound that can form polymers with compounds [A1] and [A2] upon exposure to radiation. Compound [A3] can be formulated into the composition to adjust its viscosity or enhance its crosslinking structure. As compound [A3], compounds having vinyl unsaturated groups are preferably used; specifically, examples include: vinyl compounds, compounds containing (meth)acryloyl groups, aromatic vinyl compounds, etc. Among these, compounds containing (meth)acryloyl groups are preferred in terms of copolymerization with compounds [A1] and [A2], or in terms of ease of adjusting the viscosity of the composition.

[0096] [A3] compounds can be either monofunctional or polyfunctional. Specific examples of [A3] compounds that are monofunctional include: alkyl (meth)acrylates, (meth)acrylates having an alicyclic structure, (meth)acrylates having an aromatic ring structure, and aromatic vinyl compounds.

[0097] Specific examples of the compounds mentioned above, as alkyl methacrylates, include: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, and stearyl methacrylate. Examples of methacrylates having an alicyclic structure include: cyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, and tricyclohexyl methacrylate [5.2.1.0]. 2，6 ] Decane-8-yl ester, (meth)acrylate tricyclic [5.2.1.0] 2，5 Examples of methyl methacrylates with aromatic ring structures include: phenyl methacrylate, benzyl methacrylate, naphthyl methyl methacrylate, naphthyl ethyl methacrylate, phenoxy ethyl methacrylate, m-phenoxyphenyl methyl methacrylate, and o-phenylphenoxyethyl methacrylate. Examples of aromatic vinyl compounds include: styrene, methylstyrene, α-methylstyrene, tert-butoxystyrene, and vinylnaphthalene.

[0098] When the [A3] compound is a multifunctional compound, a multifunctional (meth)acrylate is preferably used. Examples of multifunctional (meth)acrylates include difunctional (meth)acrylates and trifunctional or higher (meth)acrylates. Specific examples of these include difunctional (meth)acrylates such as ethylene glycol dimethacrylate, propylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonanediol dimethacrylate, 1,10-decanediol dimethacrylate, diethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, etc.

[0099] Examples of trifunctional or higher (meth)acrylates include, in addition to, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ethylene oxide modified dipentaerythritol hexa(meth)acrylate, tris(2-(meth)acryloyloxyethyl) phosphate, succinic acid modified pentaerythritol tri(meth)acrylate, succinic acid modified dipentaerythritol penta(meth)acrylate, and carboxyl-containing polyacid-modified (meth)acrylate oligomers, compounds having straight-chain alkylene and alicyclic structures and having two or more isocyanate groups, and compounds having one or more hydroxyl groups and having three, four, or five (meth)acryloyloxy groups, which are obtained by reacting them to form polyfunctional carbamate acrylate compounds.

[0100] From the viewpoint of ensuring the curability of this composition, the content of compound [A3] is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less, relative to 100 parts by mass of the total amount of polymeric compounds (i.e., compounds [A1], [A2], and [A3]) contained in this composition. Furthermore, from the viewpoint of fully obtaining the improvement effect on viscosity, etc., brought about by the formulation of compound [A3], the content of compound [A3] is preferably 1 part by mass or more, more preferably 5 parts by mass or more, relative to 100 parts by mass of the total amount of polymeric compounds contained in this composition.

[0101] • [C] Polymerization inhibitor

[0102] Polymerization inhibitors are components that improve the storage stability of this composition. Polymerization inhibitors are not particularly limited, but examples include: sulfur compounds, quinones (e.g., benzoquinone), hydroquinones (e.g., hydroquinone, 2,5-di-tert-butylhydroquinone), polyoxyethylene compounds (e.g., p-methoxyphenol), amine compounds (e.g., N,N-diethylhydroxyamine), and nitrosoamine compounds (e.g., N-nitroso-N-phenylhydroxyamine aluminum).

[0103] When a polymerization inhibitor is incorporated into this composition, the content of the polymerization inhibitor is preferably 0.01 to 1.5 parts by mass, more preferably 0.02 to 1.2 parts by mass, and even more preferably 0.02 to 1.0 parts by mass, relative to 100 parts by mass of the polymerizable compounds contained in the composition.

[0104] ·[D] surfactant

[0105] Surfactants can be used to improve the coatability of this composition (wetting spread or reduction of coating unevenness). Examples of surfactants include fluorinated surfactants, silicone surfactants, and nonionic surfactants.

[0106] Specific examples of surfactants, as fluorinated surfactants, include the following trade names: Megafac F-171, Megafac F-172, Megafac F-173, Megafac F-251, Megafac F-430, F-554, F-563 (manufactured by DIC); Fluorad FC430, Fluorad FC431 (manufactured by Sumitomo 3M); 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); Polyflow No.75, Polyflow No.95 (manufactured by Kyoei Chemical); FTX-218 (manufactured by NEOS); Eftop EF301, Eftop EF303, Eftop EF352 (manufactured by Shin-Akita Chemical), etc.

[0107] As silicone-based surfactants, the following trade names can be listed: SH200-100cs, SH28PA, SH30PA, SH89PA, SH190, SH8400, SH193, SZ6032, SF8428, DC57, DCl90, PAINTAD 19, FZ-2101, FZ-77, FZ-2118, L-7001, L-7002 (Toray Dow Corning) DowComing (manufactured); organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.); BYK-300, BYK-306, BYK-310, BYK-330, BYK-335, BYK-341, BYK-344, BYK-370, BYK-340, BYK-345 (manufactured by BYK-Chemie Japan).

[0108] Examples of nonionic surfactants include: polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oil-based ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate.

[0109] When a surfactant is incorporated into this composition, the surfactant content is preferably 0.01 to 3 parts by mass, more preferably 0.02 to 2 parts by mass, and even more preferably 0.1 to 1.0 parts by mass, relative to 100 parts by mass of the polymerizable compound contained in the composition.

[0110] Other components, besides those listed above, may include, for example, antioxidants, sensitizers, softeners, plasticizers, adhesion promoters, and organic solvents. The proportions of these components can be appropriately selected based on their suitability without impairing the effects of this disclosure.

[0111] Here, if necessary for dissolving the various components formulated in this composition, an organic solvent may be incorporated into the composition. However, from the viewpoint of forming a hardened film (particularly an organic sealing layer protecting the organic light-emitting layer of an organic EL element) without heat treatment, it is preferable to minimize the use of organic solvents. Specifically, the content of organic solvents 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, and particularly preferably substantially non-existent. Here, in this specification, "substantially non-existent" organic solvents means that the amount of organic solvents contained in this composition is 1% by mass or less, preferably 0.5% by mass or less.

[0112] When an organic solvent is incorporated into this composition, the preferred organic solvent is one that can dissolve or disperse the components incorporated into the composition without reacting with them. Specifically, examples include alcohols, ketones, esters, ethers, aromatic hydrocarbons, and amides.

[0113] Specific examples of these include, as alcohols: methanol, ethanol, isopropanol, butanol, octanol, etc.; as ketones: acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.; as esters: ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl-3-methoxypropionate, etc.; as ethers: polyoxyethylene lauryl ether, ethylene glycol monomethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, diethylene glycol methyl ethyl ether, etc.; as aromatic hydrocarbons: benzene, toluene, xylene, etc.; and as amides: dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc.

[0114] This composition can be prepared by mixing [A1] compound, [A2] compound, and [B] free radical polymerization initiator, as well as other components as needed. From the viewpoint of producing a curable composition with good sensitivity, or forming a curable film with high sealing effect, the content of the polymerizable compound in this composition is preferably 80 parts by mass or more, more preferably 85 parts by mass or more, and even more preferably 90 parts by mass or more, relative to 100 parts by mass of the total composition.

[0115] The viscosity of this composition, measured using 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 this composition is below 40.0 mPa·s, it exhibits good wetting and spreading properties when applied to a substrate by inkjet coating, suppressing uneven coating caused by depressions, etc. Furthermore, if the viscosity of this composition is above 1.0 mPa·s, sufficient film thickness can be ensured when applying it to a substrate, forming an organic sealing layer that adequately demonstrates a sealing effect. Therefore, this composition is particularly preferred as a curing composition for inkjet coating.

[0116] From the viewpoint of obtaining a curable composition with excellent inkjet coating properties, the viscosity of this composition is more preferably 35.0 mPa·s or less, more preferably 30.0 mPa·s or less, and particularly preferably 25.0 mPa·s or less. Furthermore, from the viewpoint of sufficiently ensuring film thickness, the viscosity of this composition is more preferably 2.0 mPa·s or more, and more 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 Standard (JIS) K2283.

[0117] This is not intended to limit the invention, but it is believed that the free radical copolymerization of compounds [A1] and [A2], where the [A1] compound, with its relatively low electron density in the vinyl unsaturated bonds, acts as an electron-accepting monomer, and the [A2] compound, with its relatively high electron density in the vinyl unsaturated bonds, acts as an electron-donating monomer, leads to alternating copolymerization of compounds [A1] and [A2]. This results in a faster curing reaction compared to free radical polymerization of either [A1] or [A2] compound alone. Consequently, the curing composition of this disclosure, containing both [A1] and [A2] compounds, is considered to achieve both low viscosity and high sensitivity while exhibiting excellent curing properties. Furthermore, this composition is preferred in terms of reducing the amount of [A2] compound used and achieving low odor.

[0118] Hardened films and organic EL elements

[0119] The cured film disclosed herein (hereinafter also referred to as "this cured film") is formed from a cured composition prepared as described. According to this composition, a cured film with a high refractive index of 1.55 or higher, and further, 1.60 or higher, can be obtained. This composition can be used, for example, as a sealing structure for organic EL elements, a microlens, an anti-reflective film, a co-diffraction grating for AR elements, and various other materials. In particular, this composition is especially effective as a sealant for thin-film sealing (TFE) of organic EL elements, i.e., a sealant for organic EL elements.

[0120] This curing film and the organic EL element through which the organic light-emitting layer is sealed can use this composition and can be manufactured by a method including the following steps 1 and 2.

[0121] (Step 1) The step of coating the composition onto the light-emitting layer forming surface of the substrate on which the organic light-emitting layer has been formed.

[0122] (Step 2) Step of irradiating with radiation and hardening the composition.

[0123] The following is a detailed description of each process.

[0124] [Process 1: Coating Process]

[0125] In this process, the composition is coated onto the light-emitting layer forming surface of a substrate on which the organic light-emitting layer is formed, thereby forming a coating film containing the composition on the light-emitting layer forming surface. On the substrate on which the composition is coated, a laminate containing 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 this laminate constitutes an organic EL element. The light-emitting layer forming surface of the composition can be covered by an inorganic film (inorganic sealing layer). Examples of inorganic materials constituting the inorganic film include silicon nitride (SiNx) or silicon oxide (SiOx). In this case, a thin film sealing layer containing both an organic sealing layer and an inorganic sealing layer is formed on the organic light-emitting layer as a sealing structure.

[0126] Methods for coating this composition include, for example, spraying, roller coating, spin coating, stencil coating, bar coating, and inkjet coating. In terms of yield and thin-film formation, inkjet coating is preferred. In particular, this composition exhibits excellent curing properties while maintaining low viscosity, making inkjet coating particularly advantageous.

[0127] [Process 2: Hardening Process]

[0128] In this process, a hardened film is formed by irradiating the coating film formed in step 1 with radiation and then hardening the coating film. Examples of radiation include ultraviolet light, far-ultraviolet light, visible light, X-rays, and charged particle beams such as electron beams. Ultraviolet light is preferred among these, and for example, ultraviolet light with a wavelength of 350 nm to 400 nm can be preferably used as the irradiation light. The exposure dose of the radiation is preferably 0.05 J / m². 2 ~10J / m 2 Therefore, an organic EL element coated with an organic sealing layer containing this composition can be obtained. The thickness of the hardened film is typically 0.5 μm to 15 μm. The organic sealing layer formed by this composition can also be coated with an inorganic film. Examples of inorganic materials constituting the inorganic film include silicon nitride (SiNx) or silicon oxide (SiOx).

[0129] [Example]

[0130] The present invention will be specifically described below through examples, but the present invention is not limited to the following examples. Furthermore, unless otherwise specified, "parts" and "%" in the examples and comparative examples refer to quality standards.

[0131] 1. Synthesis of compounds

[0132] [Synthetic Example 1] Synthesis of compound (A1-1)

[0133] 1 L of dehydrated diethyl ether, 1 L of dehydrated tetrahydrofuran, 38 mL of phenylphosphonic acid dichloride, and 20 mg of 4-methoxyphenol were added to a 3 L three-necked flask containing a nitrogen inlet tube and a thermometer. The flask was cooled to -70 °C using dry ice and acetone. Next, 536 mL of 1.0 M vinyl magnesium solution was added dropwise to ensure the internal temperature did not exceed -70 °C, and the mixture was stirred directly at -70 °C for 3 hours. After the reaction was complete, the reaction mixture was separated and washed with 2 L of 2.4 M hydrochloric acid water to remove the aqueous layer. The organic layer was then washed three times with saturated sodium bicarbonate solution. The mixture was then dried with anhydrous sodium sulfate, purified using a silica column (developed with ethyl acetate), concentrated under reduced pressure, and dried under vacuum to obtain 23 g of a white solid of compound (A1-1) (refer to procedure 1).

[0134] [Chemistry 8]

[0135]

[0136] [Synthetic Example 2] Synthesis of compound (A1-3)

[0137] In Synthesis Example 1, 27.5 g of phenylphosphochloride was used instead of 38 mL of phosphonic acid dichloride. Otherwise, the same method as in Synthesis Example 1 was used to synthesize the compound (A1-3) as a white solid (see Procedure 2).

[0138] [Chemistry 9]

[0139]

[0140] [Synthesis Example 3] Synthesis of compound (A2-2)

[0141] 12.8 g of dithiol, 320 g of 1,2-dibromoethane, and 0.7 g of tetrabutylammonium bromide were added to a 1000 mL three-necked flask including a nitrogen inlet tube and a thermometer, and the flask was cooled in an ice bath. Next, 34.9 g of a 30% potassium hydroxide aqueous solution was added, maintaining the temperature below 30°C, and the reaction was carried out for 3 hours below 30°C. After the reaction was complete, the aqueous layer was discarded, and the organic layer was washed twice with water, then dried using magnesium sulfate, concentrated under reduced pressure, and solidified to obtain a white solid of compound (A2-2-1). Next, all of the obtained compound (A2-2-1) was added to a 500 mL three-necked flask including a nitrogen inlet tube and a thermometer, followed by the addition of 170 g of dimethyl sulfoxide and cooling in an ice bath. Then, 27 g of a 50% potassium hydroxide aqueous solution was added, maintaining the internal temperature below 30°C, and the reaction was carried out directly at room temperature for 3 hours. After the reaction was completed, 500 mL of ethyl acetate was added and the aqueous layer was removed. The organic layer was washed twice with water and then concentrated under reduced pressure and dried under vacuum to obtain 7.5 g of liquid compound (A2-2) (refer to procedure 3).

[0142] [Chemistry 10]

[0143]

[0144] 2. Preparation of the hardening composition

[0145] The following shows the types and abbreviations of the [A1] compounds, [A2] compounds, [A3] compounds, [B] free radical polymerization initiators, [C] polymerization inhibitors, and [D] surfactants used in the preparation of the curing compositions.

[0146] <[A1] compound>

[0147] (A1-1): Phenyldivinylphosphine oxide (a compound obtained by synthesis example 1)

[0148] (A1-2): Diethyl vinyl phosphate (manufactured by Tokyo Chemical Co., Ltd.)

[0149] (A1-3): Trivinylphosphine oxide (a compound obtained by synthesis example 2)

[0150] (A1-4): Bis(vinylsulfonyl)methane (manufactured by Tokyo Chemical Co., Ltd.)

[0151] (A1-5): Vinyl phenyl sulfoxide (manufactured by Tokyo Chemical Co., Ltd.)

[0152] <[A2] compound>

[0153] (A2-1): Bis(4-vinylthiophenyl) sulfide (manufactured by Sumitomo Seikan Co., Ltd.)

[0154] (A2-2): 2,5-Divinylmercapto-1,3,4-thiadiazole (a compound obtained by synthesis example 3)

[0155] <[A3] Compound>

[0156] (A3-1): Acrylic acid monomer, trade name "Light Acrylate POB-A" (manufactured by Kyoei Chemical Co., Ltd.)

[0157] (A3-2): Neopentyl glycol diacrylate, trade name "A-NPG" (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)

[0158] (A3-3): Acrylic acid monomer, trade name "Light Acrylate NMT-A" (manufactured by Kyoei Chemical Co., Ltd.)

[0159] <[B] Free Radical Polymerization Initiators>

[0160] (B-1): Photoradical polymerization initiator, trade name "TR-PBG-345" (manufactured by TRONLY).

[0161] (B-2): Photoradical polymerization initiator, trade name "Omnirad TPO"

[0162] <[C]Polymerization Inhibitor>

[0163] (C-1): N-nitroso-N-phenylhydroxyamine aluminum

[0164] (C-2): 2,5-Di-tert-butylhydroquinone

[0165] <[D]surfactants>

[0166] (D-1): Silicone surfactant, trade name "DOWSIL™ SH8400" (manufactured by Toray Dow Corning).

[0167] (D-2): Silicone surfactant, trade name "PAINTAD 19" (manufactured by Toray Dow Corning).

[0168] [Example 1]

[0169] Add 30 parts by mass of compound (A1-1), 70 parts by mass of compound (A2-1), 3 parts by mass of free radical polymerization initiator (B-1), 0.5 parts by mass of polymerization inhibitor (C-1), and 0.5 parts by mass of surfactant (D-1), mix and stir, and then filter using a 0.2 μm filter to prepare a curable composition (T-1).

[0170] [Examples 2-10, Comparative Examples 1-4]

[0171] The hardening compositions of Examples 2 to 10 and Comparative Examples 1 to 4 were prepared using the same methods as in Example 1, except that each component was prepared according to the types and amounts (parts by mass) shown in Table 1.

[0172]

[0173] 3. Evaluation

[0174] For the curable compositions of Examples 1 to 10 and Comparative Examples 1 to 4, the viscosity was measured, and the coating unevenness caused by inkjet coating (IJ coating) was evaluated. In addition, a cured film was formed using the curable compositions of Examples 1 to 10 and Comparative Examples 1 to 4, and the following items were evaluated by the method described below. The evaluation results are shown in Table 2. In addition, in Table 2, "-" indicates that the evaluation was not performed.

[0175] <Measurement of viscosity>

[0176] Using an E-type viscometer (RE-85L manufactured by Toki Sangyo Co., Ltd.), the viscosity (mPa·s) of the curable composition at 25 °C and 20 rpm was measured.

[0177] <Evaluation of IJ coating unevenness>

[0178] SiNx was formed on a glass substrate to a film thickness of 100 nm to produce a substrate for evaluation. For the evaluation substrate, inkjet ejection of the curable composition was performed from the inkjet head of a piezoelectric inkjet printer at a pitch of 50 μm × 50 μm to produce a coating film with a side length of 10 cm. Further, after 5 minutes, ultraviolet irradiation was performed using a light emitting diode (LED) lamp with a wavelength of 395 nm at an exposure amount of 3000 mJ / cm 2 to cure the coating film. At this time, the voltage conditions of the inkjet head were changed so that the film thickness of the cured film became 8 μm, and the amount of one drop of ejected ink was adjusted. The obtained cured film was observed visually and with a microscope (100 times magnification), and the IJ coating unevenness was evaluated according to the following criteria.

[0179] ◎: No coating unevenness was observed visually or with a microscope.

[0180] o: Coating unevenness was observed with a microscope, but not visually.

[0181] △: Coating unevenness caused by partial film thickness variation was observed visually.

[0182] ×: An uncoated area was observed visually.

[0183] <Evaluation of curability>

[0184] A coating film was formed by coating the curable composition on a glass substrate, and light irradiation was performed using a 395-nm LED lamp. The curability until the viscosity disappeared was evaluated while changing the exposure amount.

[0185] ◎: No tackiness after light irradiation of less than 1 J / m 2

[0186] ○: Through 1J / m 2 Above but less than 3J / m 2 Light irradiation without stickiness

[0187] △: Through 3J / m 2 Above but less than 5J / m 2 Light irradiation without stickiness

[0188] ×: 5 J / m is required for hardening until the viscosity disappears. 2 The above light irradiation

[0189] <Determination of Refractive Index>

[0190] A curable composition was coated onto a 4-times silicon wafer using spin coating, and then irradiated with a 395nm LED until the adhesiveness disappeared, thereby obtaining a cured film. The refractive index of the cured film was measured using a Model 201 (manufactured by Metricon) and the prism coupler method at a measurement wavelength of 635.8nm.

[0191] <Evaluation of preservation stability>

[0192] Place 10 mL of the curing composition into a spiral tube and store it at 40°C in the dark for 7 days. Calculate the viscosity increase rate before and after storage according to mathematical formula (I) and evaluate it according to the following criteria.

[0193] Viscosity increase rate (%) = [Viscosity after storage / Viscosity before storage] × 100…(I)

[0194] ○: 100% or more but less than 105%

[0195] △: 105% or higher but less than 110%

[0196] ×: 110% or more

[0197] <Fabrication of Organic EL Components>

[0198] Prepare multiple array substrates, the array substrates having: a glass substrate ("OA-10" manufactured by Nippon Electric Glass Co., Ltd.) on which indium tin oxide (ITO) transparent electrodes are formed in an array; and a planarization layer with a film thickness of 3 μm having contact holes that expose only a portion of the ITO transparent electrodes formed in an array.

[0199] An Al film with a thickness of 100 nm is formed on a planarization layer using an Al target and a direct current (DC) sputtering method. An ITO film with a thickness of 20 nm is formed on the Al film using an ITO target and a DC magnetron reactive sputtering method. This is used to form an anode layer containing both the Al and ITO films.

[0200] A coating is formed on the anode layer using a photoresist material (the composition of Example 1 described in Japanese Patent No. 6303588), and a series of processes including exposure, development, water washing, air drying and heat treatment are performed to form a pixel-defined layer having a portion of the anode layer as an opening area.

[0201] The substrate with the anode and pixel defined layers is moved to the vacuum film deposition chamber. After the film deposition chamber is vented to 1E-4Pa, a vapor deposition mask with a defined pattern is used on the substrate. Molybdenum oxide (MoOx) with hole injection capability is deposited by resistance heating vapor deposition at a film deposition rate of 0.004nm / sec to 0.005nm / sec, thereby forming a hole injection layer with a film thickness of 1nm.

[0202] Using a pre-designed vapor deposition mask on the hole injection layer, a hole-transporting layer of 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (α-NPD) was deposited under the same venting conditions as the hole injection layer using resistance heating vapor deposition, resulting in a hole transport layer with a thickness of 35 nm. The deposition rate was 0.2 nm / sec to 0.3 nm / sec.

[0203] An evaporation mask with a predetermined pattern was used on the hole transport layer. An alkylated complex, tris(8-hydroxyquinoline)aluminum, serving as the green light-emitting material, was deposited using resistance heating evaporation under the same conditions as the hole transport layer, thus forming an organic light-emitting layer with a thickness of 35 nm. The deposition rate was below 0.5 nm / sec.

[0204] Lithium fluoride was deposited on the organic light-emitting layer using resistance heating evaporation under the same venting conditions as the hole injection layer, thus forming an electron injection layer with a thickness of 0.8 nm. The deposition rate was below 0.004 nm / sec.

[0205] Subsequently, magnesium (Mg) and silver (Ag) films were simultaneously deposited on the electron-injected layer using resistance heating evaporation under the same venting conditions as the hole-injected layer, thereby forming a first cathode layer with a film thickness of 5 nm. The film deposition rate was below 0.5 nm / sec.

[0206] The substrate is then transferred to another film-forming chamber (sputtering chamber), where an ITO target is used on the first cathode layer and a second cathode layer with a thickness of 100 nm is formed using radio frequency (RF) sputtering, thereby obtaining an organic EL device for evaluation.

[0207] <Formation of the thin film sealing layer>

[0208] The obtained organic EL element was subjected to a thin film sealing layer through the following procedure. The organic EL element was transferred to a film deposition chamber (sputtering chamber), and an inorganic sealing layer (SiNx film) with a thickness of 100 nm was formed on the cathode layer using a SiNx target and RF sputtering. Subsequently, the organic EL element was transferred to a glove box purged with N2, and the curable compositions of Examples 1-10 and Comparative Examples 1-4 were printed into a prescribed pattern using a piezoelectric inkjet printer. Then, a UniJet E110ZHD 395nm LED lamp manufactured by Ushio Electric Co., Ltd. was used at an exposure of 3000 mJ / cm². 2 The curable composition is hardened by light irradiation to form an organic sealing layer with a thickness of 10 μm. The organic EL element is then transferred to the film deposition chamber (sputtering chamber), and an inorganic sealing layer (SiNx film) with a thickness of 100 nm is formed on the organic sealing layer using a SiNx target and RF sputtering.

[0209] <Reliability of Organic EL Components>

[0210] For organic EL elements with a thin film sealing layer, after being stored at 85°C and 85% humidity for 100 hours, at 10 mA / cm 2 Apply a forward current and observe the emission appearance (dark spot). Based on the emission appearance, evaluate the reliability of the organic EL device according to the following criteria.

[0211] ◎: The area ratio of non-lit areas is 0% or more but less than 5%.

[0212] △: The area of ​​the non-lit area is more than 5% but less than 20%.

[0213] ×: The area ratio of the non-lit area is 20% or more.

[0214] [Table 2]

[0215]

[0216] As shown in Table 2, the curing compositions of Examples 1 to 10 have viscosity as low as 20 mPa·s or less, resulting in less uneven coating when applied to the substrate by inkjet printing. Furthermore, the curing compositions of Examples 1 to 10 exhibit viscosity less than 1 J / m 2The adhesiveness disappears upon irradiation with light, exhibiting excellent curing properties. Furthermore, the cured films formed from the curing compositions of Examples 1 to 10 display a high refractive index of 1.60 or higher, and even under prolonged storage at high temperature and humidity, the formation of dark spots can be suppressed, resulting in high reliability of the organic EL element. Among these, the cured films obtained in Examples 1 to 5 and Examples 7 to 10, in particular, exhibit a high refractive index of 1.65 or higher.

[0217] In contrast, the curing properties of the curing compositions of Comparative Examples 1 to 4 were worse than those of Examples 1 to 10. In particular, Comparative Examples 1 and 4, which contained compound [A2] as a polymerizable compound but did not contain compounds [A1] or [A3], received a curing property rating of "×" and a component reliability rating of "×". Furthermore, Comparative Example 2, which contained compounds [A2] and [A3] as polymerizable compounds but did not contain compound [A1], received a curing property rating of "○", but a component reliability rating of "△", which was worse than Examples 1 to 10. Since the curing composition of Comparative Example 3 was in solid form, it could not be formed into a curing film by inkjet coating.

Claims

1. A hardening composition comprising: [A1] The compound has an ethylene unsaturated group and at least one group [F1] selected from the group represented by the following formula (1), -S(=O)- and -S(=O)2-, said group [F1] having a partial structure adjacent to the carbon-carbon unsaturated bond in the ethylene unsaturated group; In equation (1), X 1 It consists of oxygen, sulfur, or selenium atoms; " indicates a bonding bond; [A2] The compound has an ethylene unsaturated group and a thioether group, wherein the thioether group has a partial structure adjacent to the carbon-carbon unsaturated bond in the ethylene unsaturated group; as well as [B] Free radical polymerization initiator; The molar ratio of the total number of vinyl unsaturated groups (NA) in the [A1] compound to the total number of vinyl unsaturated groups (NB) in the [A2] compound is (NA):(NB) = 1:0.5 to 1:1.

5.

2. The curing composition according to claim 1, wherein the [A1] compound is at least one selected from the group consisting of compounds represented by formula (3-1) and compounds represented by formula (3-2). In equation (3-1), R 1 It is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms; X 1 It consists of oxygen, sulfur, or selenium atoms; R 2 It is a monovalent organogroup with 1 to 20 carbon atoms; r is an integer from 1 to 3; when r is 2 or 3, multiple R 1 Whether they are the same or different, when r is 1, multiple R 2 Same or different; In equation (3-2), R 1 Y is a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms; 1 For -S(=O)- or -S(=O)2-; R 3 For t-valent organic groups with 1 to 20 carbon atoms; t is an integer from 1 to 4; when t is 2 or higher, multiple R... 1 Same or different, multiple Y 1 Same or different.

3. The curing composition according to claim 1 or 2, wherein the viscosity, measured using an E-type viscometer at 25°C and 20 rpm, is in the range of 1.0 mPa·s to 40.0 mPa·s.

4. The curable composition according to claim 1 or 2, wherein the [A2] compound has an aromatic ring and a partial structure in which a thioether group adjacent to a carbon-carbon unsaturated bond in an ethylene unsaturated group is bonded to the aromatic ring.

5. The curing composition according to claim 1 or 2, wherein the [A2] compound is at least one selected from the group consisting of compounds represented by formula (7-1), formula (7-2), formula (7-3), formula (7-4), and formula (7-5). In equations (7-1) to (7-5), R 12 and R 13 Each is independently a halogen atom or an alkyl group having 1 to 6 carbon atoms; R 14 R 15 and R 16 Each a1 and a2 is an independent hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms; each a1 and a2 is an independent integer from 0 to 4; each a3 and a5 is an independent integer from 0 to 5; each a4 and a6 is an independent integer from 0 to 7; wherein, The equation satisfies a3+a5≦5 and a4+a6≦7; there are multiple R values ​​in the equation. 12 In the case of multiple R 12 Whether the R values ​​are the same or different, there are multiple R values ​​in the formula. 13 In the case of multiple R 13 Whether the R values ​​are the same or different, there are multiple R values ​​in the formula. 15 In the case of multiple R 15 Same or different.

6. The curable composition according to claim 1 or 2, wherein the content of the organic solvent is 0% by mass or more and 3% by mass or less.

7. The curing composition according to claim 1 or 2, for inkjet coating.

8. The curable composition according to claim 1 or 2 is a sealant for organic electroluminescent elements.

9. A hardening film formed from the hardening composition as described in any one of claims 1 to 8.

10. An organic electroluminescent element, wherein the light-emitting layer is sealed by a hardened film as described in claim 9.

11. A method for manufacturing an organic electroluminescent element, comprising the steps of coating a curable composition as described in any one of claims 1 to 7 onto the light-emitting layer forming surface of a substrate on which an organic light-emitting layer is formed, irradiating with radiation and curing the curable composition, thereby forming a sealed structure.

12. The method for manufacturing an organic electroluminescent element according to claim 11, wherein the curable composition is applied to the surface of the light-emitting layer by inkjet coating.

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