JP2011021183A - Photocurable resin composition, sealing agent for organic electroluminescence display elements, and organic electroluminescence display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photocurable resin composition capable of obtaining a sealing agent for organic electroluminescence display elements being excellent in transparency and moisture resistance and low viscous. <P>SOLUTION: This photocurable resin composition is a photocurable resin composition comprising a cationically polymerizable compound and a cation photopolymerization initiator wherein the cationically polymerizable compound contains an epoxy resin represented by the general formula (1): (where R<SP>1</SP>is hydrogen or methyl; R<SP>2</SP>to R<SP>5</SP>are each hydrogen, halogen, hydroxy, a straight chain, branched or cyclic 1-10C monovalent alkyl or 1-10C alkoxy, and R<SP>2</SP>to R<SP>5</SP>may be the same or different; and n is an integer of 0 to 20), and an epoxy resin having an alicyclic skeleton. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a photocurable resin composition that is excellent in transparency and moisture resistance and that can provide a low viscosity organic electroluminescent display element sealant. Moreover, this invention relates to the sealing agent for organic electroluminescent display elements and organic electroluminescent display element which use this photocurable resin composition.

An organic electroluminescence (hereinafter also referred to as organic EL) display element has a laminated structure in which an organic light emitting material layer is sandwiched between a pair of electrodes facing each other, and electrons are transmitted from one electrode to the organic light emitting material layer. By being injected and holes are injected from the other electrode, electrons and holes are combined in the organic light emitting material layer to emit light. Thus, since the organic EL display element performs self-emission, it has better visibility than a liquid crystal display element that requires a backlight, can be reduced in thickness, and can be driven by a DC low voltage. Has the advantage.

In recent years, attention has been paid to a top emission type organic EL display element that takes out light emitted from an organic light emitting material layer from the upper surface side, instead of a conventional bottom emission type organic EL display element. This method has an advantage that it has a high aperture ratio and is driven at a low voltage, which is advantageous for extending the life. In such a top emission type organic EL display element, usually, the laminate is sandwiched between two moisture-proof substrates made of a transparent material such as glass, and the space between the moisture-proof substrates is filled with a filler. (For example, refer to Patent Document 1). However, in such a top emission type organic EL display element, there is no space for placing a desiccant so as not to shield the light extraction direction, and even if it is filled with a filler, a sufficient moisture-proof effect Is difficult to obtain, and there is a problem that the life is shortened.
Therefore, conventionally, an adhesive having high moisture resistance has been selected and used by using moisture permeability as an index. However, as expected even if an organic EL display element is sealed using the adhesive thus selected. High moisture resistance was not obtained.

Further, in the top emission type organic EL display element, since the sealant is arranged in the light extraction direction, a sealant without coloring is required. However, the conventional sealant has a problem that the sealant is colored when exposed to heat or ultraviolet rays, and color reproducibility and luminance are lowered.

In addition, as the development of large-screen organic EL displays progresses, in addition to being excellent in transparency and moisture resistance, it is a sealing agent for organic EL display elements that can uniformly and accurately seal large-area organic EL display elements. Therefore, a sealing agent for organic EL display elements having a low viscosity has been demanded.

On the other hand, the present inventors include, as a photopolymerizable compound, an organic EL display element sealing agent containing an epoxy resin having an aliphatic cyclic skeleton and an epoxy resin having an aromatic ring in a specific ratio. It was found that sealing with excellent transparency and moisture resistance was possible and that the viscosity was relatively low (Patent Document 2). However, in recent years, an organic EL display having a larger screen has been demanded, and the demand for a sealing agent for organic EL display elements having a lower viscosity has been increased accordingly.

JP 2001-357773 A JP 2005-378504 A

An object of this invention is to provide the photocurable resin composition which can obtain the sealing agent for organic electroluminescent display elements which is excellent in transparency and moisture resistance, and is low-viscosity. Moreover, this invention aims at providing the sealing agent for organic electroluminescent display elements which uses this photocurable resin composition, and an organic electroluminescent display element.

The present invention is a photocurable resin composition comprising a cationically polymerizable compound and a photocationic polymerization initiator, wherein the cationically polymerizable compound comprises an epoxy resin represented by the following general formula (1), a fat Photocuring containing an epoxy resin having an aliphatic cyclic skeleton and an epoxy resin having an aliphatic cyclic skeleton with respect to 100 parts by weight of the epoxy resin represented by the general formula (1) It is an adhesive resin composition.

In formula (1), R ¹ represents a hydrogen atom or a methyl group. R ^{2 to} R ^{5 each} represents a hydrogen atom, a halogen atom, a hydroxyl group, a monovalent linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. R ^{2 to} R ⁵ may be the same or different. n shows the integer of 0-20.
The present invention is described in detail below.

The present inventor, among epoxy resins having an aromatic ring, by blending an epoxy resin having a specific structure in a photocurable resin composition together with an epoxy resin having an aliphatic cyclic skeleton, The present inventors have found that a sealing agent for organic EL display elements having excellent transparency and moisture resistance and having a low viscosity can be obtained, and the present invention has been completed.

The photocurable resin composition of the present invention contains a cationic polymerizable compound.
The cationic polymerizable compound contains an epoxy resin represented by the general formula (1) and an epoxy resin having an aliphatic cyclic skeleton.
Among the epoxy resins having an aromatic ring, the photocurable resin composition of the present invention maintains high transparency and moisture resistance by selecting and using the epoxy resin represented by the general formula (1). As it is, a lower viscosity can be obtained. Since the photocurable resin composition of the present invention has a low viscosity, when used as a sealant for an organic EL display element, etc., it has good affinity with a substrate and is excellent in coatability. Moreover, since the moisture resistance is high, it is possible to suppress deterioration of the obtained organic EL display element.

In the general formula (1), n is preferably 0 to 5, and R ^{1 to} R ⁵ are preferably hydrogen atoms.
Specific examples of the epoxy resin represented by the general formula (1) include catechol diglycidyl ether (n = 0, R ^{2 to} R ⁵ = H, ortho orientation), resorcinol diglycidyl ether (n = 0). , R ^{2 to} R ⁵ = H, meta orientation), 4-ethylresorcinol diglycidyl ether (n = 0, R ² = C ₂ H ₅ , R ^{3 to} R ⁵ = H), hydroquinone diglycidyl ether (n = 0) , R ^{2 to} R ⁵ = H, para-alignment) and the like.
Among the epoxy resins represented by the general formula (1), those commercially available include, for example, Denacol EX-201 (resorcinol diglycidyl ether, manufactured by Nagase ChemteX Corporation), EX-203 (hydroquinone diglycidyl ether). , Manufactured by Nagase ChemteX Corporation).

The photocurable resin composition of the present invention can increase transparency and moisture resistance by containing the epoxy resin having the aliphatic cyclic skeleton, and is represented by the general formula (1). It is possible to prevent the epoxy resin from crystallizing.
The epoxy resin having an aliphatic cyclic skeleton is not particularly limited as long as it has an aliphatic cyclic skeleton and an epoxy group in the structure, and the aliphatic cyclic skeleton is included in the structure or in a repeating unit. It may be a resin having only one, or may be a resin having two or more aliphatic cyclic skeletons in the repeating unit, but a resin having two or more aliphatic cyclic skeletons in the repeating unit is more preferable. Preferably used. When the epoxy resin having an aliphatic cyclic skeleton is a resin having two or more aliphatic cyclic skeletons in a repeating unit, the resulting photocurable resin composition is more excellent in transparency, moisture resistance, etc. It becomes.

The epoxy resin having two or more aliphatic cyclic skeletons in the repeating unit is not particularly limited, but is at least one selected from the group consisting of the following general formulas (2), (3) and (4). Is preferred. The compound represented by the following general formula (2), (3) or (4) has characteristics such as low water content due to low polarity and high heat resistance and transparency due to having an aliphatic cyclic skeleton.
Especially, it is more preferable that it is resin represented by following General formula (2).

In formula (2), n represents an integer of 0 to 20. R ⁶ and R ⁷ represent hydrogen or a linear or branched alkyl group having 1 to 12 carbon atoms, and R ⁶ and R ⁷ may be the same as or different from each other.

In formula (3), n represents an integer of 0 to 20. R ^{8 to} R ¹⁵ represent hydrogen or a linear or branched alkyl group having 1 to 12 carbon atoms, and R ^{8 to} R ¹⁵ may be the same as or different from each other.

In formula (4), n represents an integer of 0 to 20.

In the general formulas (2), (3), and (4), n is preferably 1 or more. By setting the n to 1 or more, the transparency of the encapsulant for organic EL display elements using the photocurable resin composition of the present invention is more excellent than that in the case where n is 0. be able to. In the case where n is 0, the photocurable resin composition of the present invention is used by blending a later-described aliphatic hydrocarbon compound having a hydroxyl group in a larger amount than in the case where n is 1. The transparency of the sealing agent for organic EL display elements can be further increased. When n exceeds 20, the resulting photocurable resin composition may have too high a viscosity or may have poor compatibility with other blends.

Moreover, among the compounds represented by the general formula (2), R ⁶ and R ⁷ are preferably hydrogen, a methyl group, or an ethyl group. When R ⁶ and R ⁷ are hydrogen, a methyl group, or an ethyl group, the encapsulant for organic EL display elements using the photocurable resin composition of the present invention has excellent transparency and It has both moisture resistance. Of these, R ⁶ and R ⁷ are more preferably hydrogen.

Among the compounds represented by the chemical formula (2), commercially available compounds include, for example, Epikote YX8000 (manufactured by Mitsubishi Chemical Corporation, R ⁶ = R ⁷ = CH ₃ ), Epikote YL6753 (manufactured by Mitsubishi Chemical Corporation, R ⁶ = ^R 7 = H), and the like.

Of the compounds represented by the chemical formula (3), commercially available compounds include, for example, Epicoat YL7040 (Mitsubishi Chemical Corporation, R ⁸ = R ¹⁰ = R ¹³ = R ¹⁵ = CH ₃ , R ⁹ = R ^{11 = R 12 = R 14 =} H) , and the like.

Among the compounds represented by the chemical formula (4), examples of commercially available compounds include EP-4088 (manufactured by ADEKA).

The lower limit of the content of the epoxy resin having an aliphatic cyclic skeleton with respect to 100 parts by weight of the epoxy resin represented by the general formula (1) is 20 parts by weight, and the upper limit is 400 parts by weight. When the content of the epoxy resin having an aliphatic cyclic skeleton is less than 20 parts by weight, the sealing agent for organic EL display elements using the obtained photocurable resin composition is inferior in transparency and moisture resistance. Or the epoxy resin represented by the general formula (1) cannot be prevented from crystallizing. When the content of the epoxy resin having an aliphatic cyclic skeleton exceeds 400 parts by weight, the viscosity of the resulting photocurable resin composition becomes too high. The preferable lower limit of the content of the epoxy resin having an aliphatic cyclic skeleton is 50 parts by weight, the preferable upper limit is 200 parts by weight, the more preferable lower limit is 70 parts by weight, and the more preferable upper limit is 150 parts by weight.

The cationic polymerizable compound may further contain an epoxy resin having an aromatic ring other than the epoxy resin represented by the general formula (1) as long as the object of the present invention is not impaired.

The epoxy resin having the other aromatic ring is not particularly limited as long as it is a compound having an aromatic ring and an epoxy group in the structure except for the epoxy resin represented by the general formula (1). Examples include novolac type epoxy resins and bisphenol type epoxy resins.
The novolac type epoxy resin is not particularly limited, and examples thereof include a phenol novolak type epoxy resin, a cresol novolak type epoxy resin, a biphenyl novolak type epoxy resin, a trisphenol novolak type epoxy resin, a dicyclopentadiene novolak type epoxy resin, and the like.
The bisphenol type epoxy resin is not particularly limited. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, 2,2'-diallyl bisphenol A type epoxy resin, bisphenol S type epoxy resin, polyoxypropylene bisphenol A type epoxy resin Etc.
Among these, bisphenol A type epoxy resins and bisphenol F type epoxy resins are preferably used.
The said epoxy resin which has another aromatic ring may be used independently, and 2 or more types may be used together.

The content of the other epoxy resin having an aromatic ring is not particularly limited, but the preferred lower limit is 50 parts by weight and the preferred upper limit is 200 weights with respect to 100 parts by weight of the epoxy resin represented by the general formula (1). Part. When the content of the epoxy resin having the other aromatic ring is less than 50 parts by weight, the sealing agent for organic EL display elements using the obtained photocurable resin composition is inferior in curability. Sometimes. When the content of the epoxy resin having the other aromatic ring exceeds 200 parts by weight, the sealing agent for organic EL display elements using the obtained photocurable resin composition is inferior in transparency and moisture resistance. It may become. The minimum with more preferable content of the epoxy resin which has the said other aromatic ring is 70 weight part, and a more preferable upper limit is 100 weight part.

The photocurable resin composition of the present invention contains a photocationic polymerization initiator.
The photocationic polymerization initiator is not particularly limited as long as it generates a protonic acid or a Lewis acid by light irradiation, and may be an ionic photoacid generating type or a nonionic photoacid generating type. May be. Of these, onium salts represented by the following general formula (5) are preferred. Photocuring obtained by using an onium salt represented by the following general formula (5) as the photocationic polymerization initiator and a benzophenone derivative represented by the general formula (9) described later as a sensitizer. The coloring by the light and heat of the sealing agent for organic EL display elements formed using the conductive resin composition can be suppressed.

In the formula (5), R ¹⁶ and R ¹⁷ are hydrogen, a linear or branched alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a carboxyl group, or Represents a C 1-20 carboxylic acid alkyl ester group. R ¹⁶ and R ¹⁷ may be the same as or different from each other.
In formula (5), X ⁻ represents PF ₆ ⁻ , AsF ₅ ⁻ , BF ₄ ⁻ , or a boronic acid represented by the following general formula (6).

Among them, the above-mentioned photocationic polymerization initiator is excellent in transparency of the sealing agent for organic EL display elements using the obtained photocurable resin composition, and is unlikely to oxidize the electrode at the interface with the electrode. Since it becomes what is excellent in durability, what consists of a salt which uses the bulky boronic acid represented by the said General formula (6) as a counter anion is suitable.

Although content of the said photocationic polymerization initiator is not specifically limited, A preferable minimum is 0.1 weight part and a preferable upper limit is 10 weight part with respect to 100 weight part of said cation polymerizable compounds. If the content of the photocationic polymerization initiator is less than 0.1 parts by weight, the cationic polymerization may not sufficiently proceed or the curing reaction of the resulting photocurable resin composition may become too slow. . When the content of the above cationic photopolymerization initiator exceeds 10 parts by weight, the curing reaction of the resulting photocurable resin composition becomes too fast, and the workability is reduced, or the resulting photocurable resin composition The cured product may become non-uniform. The minimum with more preferable content of the said photocationic polymerization initiator is 0.3 weight part, and a more preferable upper limit is 5 weight part.

The photocurable resin composition of the present invention preferably further contains a curing retarder. By containing the said hardening retarder, the sealing agent for organic EL display elements which uses the photocurable resin composition obtained becomes long in pod life, and applicability | paintability improves. In addition, since it is possible to perform adhesion and sealing after irradiating light once, adhesion or sealing of a member that may be deteriorated by light is performed, or light is shielded by the sealing agent by the member or the like. Even when there is a part to be present, the entire sealant can be sufficiently cured.

The said hardening retarder is not specifically limited, For example, a polyether compound etc. are mentioned.
The polyether compound is not particularly limited, and examples thereof include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and a crown ether compound. Of these, crown ether compounds are preferred.

The crown ether compound is not particularly limited, and examples thereof include 12-crown-4, 15-crown-5, 18-crown-6, 24-crown-8, and a structure represented by the following general formula (7). And the like.

In formula (7), at least one of R ^{18 to} R ²⁹ represents an alkyl group having 1 to 20 carbon atoms. The alkyl group is selected from the group consisting of a linear or branched alkoxyl group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a carboxyl group, and a carboxylic acid alkyl ester group having 1 to 20 carbon atoms. And the adjacent R ⁿ and R ^{n + 1} (where n represents an even number of 18 to 28), together form a cyclic alkyl skeleton. May be.

Among the curing retarders having the structure represented by the general formula (7), those having at least one cyclohexyl group are preferable. By having the cyclohexyl group, the skeleton of the crown ether is stabilized and the delay effect is enhanced.
Specific examples of the curing retarder having the structure represented by the general formula (7) having the cyclohexyl group include compounds having a structure represented by the following chemical formula (8).

Since the compound having the structure represented by the chemical formula (8) has two cyclohexyl groups at positions symmetrical with respect to a line passing through the center of the 18-crown-6-ether molecule, It is considered that the delay effect is enhanced without causing distortion or the like in the skeleton of the 6-ether molecule.

Although content of the said hardening retarder is not specifically limited, A preferable minimum is 0.05 weight part and a preferable upper limit is 5.0 weight part with respect to 100 weight part of the said cationically polymerizable compounds. When the content of the curing retarder is less than 0.05 parts by weight, the photocurable resin composition of the present invention may not be sufficiently imparted with a retarding effect. When the content of the curing retarder exceeds 5.0 parts by weight, the amount of outgas generated when the photocurable resin composition of the present invention is cured increases, and the present invention is used for applications in which the outgas has a great influence. It may be difficult to use the photocurable resin composition of the invention. The minimum with more preferable content of the said retarder is 0.1 weight part, and a more preferable upper limit is 3.0 weight part.

The photocurable resin composition of the present invention preferably contains a sensitizer composed of a benzophenone derivative represented by the following general formula (9). The sensitizer has a role of further improving the polymerization initiation efficiency of the photocationic polymerization initiator and further promoting the curing reaction of the photocurable resin composition of the present invention.

In formula (9), R ³⁰ and R ³¹ represent hydrogen, a substituent represented by the following general formula (10-1), or a substituent represented by the following general formula (10-2). R ³⁰ and R ³¹ may be the same as or different from each other.

In formulas (10-1) and (10-2), R ³² represents hydrogen, a linear or branched alkyl group having 1 to 20 carbon atoms, an alkoxyl group having 1 to 20 carbon atoms, a halogen atom, or a hydroxyl group. Represents a carboxyl group or a carboxylic acid alkyl ester group having 1 to 20 carbon atoms.

Specific examples of the benzophenone derivative represented by the general formula (9) include benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4′-bis (dimethylamino) benzophenone, 4- Examples include benzoyl-4′methyldiphenyl sulfide.

The content of the sensitizer is not particularly limited, but a preferable lower limit is 0.05 parts by weight and a preferable upper limit is 3 parts by weight with respect to 100 parts by weight of the cationic polymerizable compound. When the content of the sensitizer is less than 0.05 parts by weight, the sensitizing effect may not be sufficiently obtained. When the content of the sensitizer exceeds 3 parts by weight, absorption may be excessively increased and light may not be transmitted to the deep part. The minimum with more preferable content of the said sensitizer is 0.1 weight part, and a more preferable upper limit is 1 weight part.

The photocurable resin composition of the present invention may further contain an aliphatic hydrocarbon compound having a hydroxyl group as long as the object of the present invention is not impaired.
By containing the above aliphatic hydrocarbon compound having a hydroxyl group, the photocurable resin composition of the present invention exhibits very high transparency, and is also very effective when the cured product is exposed to ultraviolet rays or heat. High transparency can be maintained.

In the present specification, the aliphatic hydrocarbon compound having a hydroxyl group means a compound comprising an aliphatic hydrocarbon skeleton having no unsaturated double bond and a hydroxyl group.
The aliphatic hydrocarbon skeleton is not particularly limited, but is preferably an aliphatic hydrocarbon skeleton having 2 to 50 carbon atoms. If the number of carbon atoms is less than 2, the hydrophilicity may become too strong, resulting in poor compatibility, and the resulting photocurable resin composition may be highly hygroscopic. When the said carbon number exceeds 50, solubility may worsen or the viscosity of the photocurable resin composition obtained may become high too much.

The aliphatic hydrocarbon compound having a hydroxyl group is not particularly limited, and examples thereof include alcohols such as (poly) ethylene glycol, (poly) propylene glycol, (poly) tetramethylene glycol, glycerin, hydroxyethyl (meth) acrylate, and glycidol. Etc. Of these, (poly) propylene glycol and (poly) tetramethylene glycol are preferred.

The aliphatic hydrocarbon compound having a hydroxyl group has a preferred lower limit of pKa value of 15 and a preferred upper limit of 19. When the pKa value of the aliphatic hydrocarbon compound having a hydroxyl group is less than 15, the acidity is too strong and the storage stability may be deteriorated. When the pKa value of the aliphatic hydrocarbon compound having a hydroxyl group exceeds 19, the basicity becomes too strong and the acid generated is weakened, so that curing inhibition may occur.

The content of the aliphatic hydrocarbon compound having a hydroxyl group is not particularly limited, but a preferable lower limit is 5 parts by weight and a preferable upper limit is 50 parts by weight with respect to 100 parts by weight of the cationic polymerizable compound. When the content of the aliphatic hydrocarbon compound having a hydroxyl group is less than 5 parts by weight, the resulting photocurable resin composition cannot maintain sufficient transparency when exposed to ultraviolet rays or heat. There is. If the content of the aliphatic hydrocarbon compound having a hydroxyl group exceeds 50 parts by weight, the curing reaction may be inhibited, or the water absorption rate of the cured product of the resulting photocurable resin composition may be increased. The minimum with more preferable content of the aliphatic hydrocarbon compound which has the said hydroxyl group is 10 weight part, and a more preferable upper limit is 40 weight part.

The photocurable resin composition of the present invention preferably further contains a thermosetting agent.
By containing the said thermosetting agent, thermosetting property can be provided to the photocurable resin composition of this invention.

The thermosetting agent is not particularly limited, and examples thereof include hydrazide compounds, imidazole derivatives, acid anhydrides, dicyandiamides, guanidine derivatives, modified aliphatic polyamines, addition products of various amines and epoxy resins, and the like.
The hydrazide compound is not particularly limited, and examples thereof include 1,3-bis [hydrazinocarbonoethyl-5-isopropylhydantoin].
The imidazole derivative is not particularly limited. For example, 1-cyanoethyl-2-phenylimidazole, N- [2- (2-methyl-1-imidazolyl) ethyl] urea, 2,4-diamino-6- [2′- Methylimidazolyl- (1 ′)]-ethyl-s-triazine, N, N′-bis (2-methyl-1-imidazolylethyl) urea, N, N ′-(2-methyl-1-imidazolylethyl) -adipamide 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole and the like.
The acid anhydride is not particularly limited, and examples thereof include tetrahydrophthalic anhydride, ethylene glycol bis (anhydro trimellitate) and the like.
These thermosetting agents may be used alone or in combination of two or more.

Although content of the said thermosetting agent is not specifically limited, A preferable minimum is 0.5 weight part and a preferable upper limit is 30 weight part with respect to 100 weight part of said cation polymerizable compounds. If the content of the thermosetting agent is less than 0.5 parts by weight, sufficient thermosetting property may not be imparted to the resulting photocurable resin composition. When the content of the thermosetting agent exceeds 30 parts by weight, the storage stability of the resulting photocurable resin composition becomes insufficient, or the moisture resistance of the cured product of the obtained photocurable resin composition is poor. Sometimes it becomes. The minimum with more preferable content of the said thermosetting agent is 1 weight part, and a more preferable upper limit is 15 weight part.

The photocurable resin composition of the present invention preferably further contains a silane coupling agent. The said silane coupling agent has a role which improves the adhesiveness of the sealing agent for organic EL display elements which uses the photocurable resin composition of this invention, and a board | substrate.

Specific examples of the silane coupling agent include γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-isocyanatopropyltrimethoxysilane. It is done. These silane compounds may be used alone or in combination of two or more.

Although content of the said silane coupling agent is not specifically limited, A preferable minimum is 0.1 weight part and a preferable upper limit is 10 weight part with respect to 100 weight part of said cation polymerizable compounds. When the content of the silane coupling agent is less than 0.1 parts by weight, the effect of improving the adhesiveness of the sealing agent for organic EL display elements using the resulting photocurable resin composition is almost obtained. There may not be. When content of the said silane coupling agent exceeds 10 weight part, an excess silane coupling agent may bleed out. The minimum with more preferable content of the said silane coupling agent is 0.5 weight part, and a more preferable upper limit is 5 weight part.

The photocurable resin composition of the present invention may contain a filler as long as the object of the present invention is not impaired.
The said filler is not specifically limited, For example, an inorganic filler, an organic filler, etc. are mentioned.
The inorganic filler is not particularly limited, for example, talc, asbestos, silica, smectite, bentonite, calcium carbonate, magnesium carbonate, alumina, montmorillonite, diatomaceous earth, magnesium oxide, titanium oxide, magnesium hydroxide, aluminum hydroxide, glass beads, Examples include barium sulfate, gypsum, calcium silicate, and sericite activated clay.
The organic filler is not particularly limited, and examples thereof include polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, and acrylic polymer fine particles.

The photocurable resin composition of the present invention contains a compound that reacts with an acid generated in the composition or an ion exchange resin in order to improve the durability of the element electrode within a range that does not impair the transparency of the cured product. May be.

Examples of the compound that reacts with the generated acid include substances that neutralize the acid, such as carbonates or bicarbonates of alkali metals or alkaline earth metals. Specifically, for example, calcium carbonate, calcium hydrogen carbonate, sodium carbonate, sodium hydrogen carbonate and the like are used.

As the ion exchange resin, any of a cation exchange type, an anion exchange type, and a both ion exchange type can be used, and in particular, a cation exchange type or a both ion exchange type capable of adsorbing chloride ions. Is preferred.

Moreover, the photocurable resin composition of the present invention may contain various known additives such as a reinforcing agent, a softening agent, a plasticizer, a viscosity modifier, an ultraviolet absorber, and an antioxidant as necessary. .

The method for producing the photocurable resin composition of the present invention is not particularly limited, and for example, a cationically polymerizable compound using a mixer such as a homodisper, a homomixer, a universal mixer, a planetarium mixer, a kneader, or a three roll. And a method of mixing a cationic photopolymerization initiator and additives such as a curing retarder, a thermosetting agent, and a silane coupling agent that are added as necessary.

The photocurable resin composition of this invention can be used suitably as a sealing agent for organic EL display elements. The sealing agent for organic EL display elements using the photocurable resin composition of the present invention is also one aspect of the present invention.

The viscosity of the sealing agent for organic EL display elements of the present invention is appropriately determined depending on the coating method used when sealing the organic EL display element, and is not particularly limited, but is 25 ° C. using a cone rotor viscometer. The preferable lower limit of the viscosity measured under the condition of 1 rpm is 10 mPa · s, and the preferable upper limit is 450 mPa · s. When the viscosity of the sealing agent for organic EL display elements is less than 10 mPa · s, the organic EL display elements may not be sealed. When the viscosity of the sealing agent for organic EL display elements exceeds 450 mPa · s, the organic EL display elements may not be sealed uniformly and accurately. The minimum with a more preferable viscosity of the said sealing agent for organic EL display elements is 50 mPa * s, and a more preferable upper limit is 300 mPa * s. The upper limit of the viscosity of the sealing agent for organic EL display elements is more preferably 230 mPa · s.

The method for applying the organic EL display element sealant of the present invention to the substrate is not particularly limited, and for example, methods such as screen printing, dispenser application, flexographic printing, and gravure printing can be used. Moreover, the sealing agent for organic EL display elements of this invention may be apply | coated to the whole surface of the said board | substrate, and may be apply | coated to a part of said board | substrate.

The shape of the sealing portion of the encapsulant for organic EL display elements of the present invention formed by coating is not particularly limited as long as it is a shape that can protect the laminate having the organic light emitting material layer from the outside air, and the above laminate The shape may completely cover the body, or a closed pattern may be formed on the periphery of the laminate. Furthermore, you may form the pattern of the shape which provided the one part opening part in the peripheral part of the said laminated body.
In addition, since the sealing agent for organic EL display elements of this invention can be made into low viscosity at normal temperature as mentioned above, the method of apply | coating to the shape which coat | covers the said laminated body completely can be performed suitably. .

The substrate on which the sealing agent for organic EL display elements of the present invention is applied (hereinafter also referred to as one substrate) is not particularly limited, and may be, for example, a substrate on which the laminate is formed. It may be a substrate on which is not formed. When the laminated body is not formed on the one substrate, the organic EL display element sealing of the present invention is applied to the one substrate so that the laminated body can be protected from outside air when the other substrate is bonded. What is necessary is just to apply | coat an agent. That is, when the other substrate is bonded, it is applied over the entire surface where the laminate is located, or when the other substrate is attached, the location where the laminate is located completely fits. You may form the sealing agent part of the closed pattern in the shape.

Moreover, although the said board | substrate is not specifically limited, It is preferable that it is a moisture-proof base material, for example, a glass base material, a metal base material, a resin base material etc. are mentioned.
Although the said glass base material is not specifically limited, For example, soda glass, an alkali free glass, etc. are mentioned.
Although the said metal base material is not specifically limited, For example, stainless steel, aluminum, etc. are mentioned.
Although the said resin base material is not specifically limited, For example, a trifluorinated polyethylene, a poly trifluoroethylene chloride (PCTFE), a polyvinylidene fluoride (PVDF), the copolymer of PVDF and PCTFE, PVDF, and polyfluorinated chlorinated ethylene And polyfluorinated ethylene polymers such as copolymers, cycloolefin resins such as dicyclopentadiene, polyesters such as polyethylene terephthalate, polyimide, polycarbonate, polyethylene, and polystyrene.

Moreover, the said laminated body may be coat | covered with the inorganic moisture-proof film | membrane. As will be described later, the sealing material for organic EL display elements of the present invention has an inorganic moisture proof structure when the tensile storage elastic modulus of the cured product is within a certain low elastic modulus region between 20 ° C. and 80 ° C. Even when it is covered with a film, it can be suitably used without damaging the moisture-proof film. The said inorganic moisture-proof film | membrane is not specifically limited, For example, the thing similar to a conventionally well-known thing is mentioned.

The method for bonding the other substrate is not particularly limited, but is preferably bonded in a reduced pressure atmosphere. The preferable lower limit of the degree of vacuum in the reduced-pressure atmosphere is 0.01 kPa, and the preferable upper limit is 10 kPa. If the degree of vacuum in the reduced-pressure atmosphere is less than 0.01 kPa, it takes time to achieve a vacuum state due to the airtightness of the vacuum apparatus and the ability of the vacuum pump, which is not realistic. When the degree of vacuum in the reduced-pressure atmosphere exceeds 10 kPa, removal of bubbles in the sealing agent for organic EL display elements of the present invention at the time of bonding the other substrate may be insufficient.

The sealing agent for organic EL display elements of the present invention can be cured by applying light having a wavelength of 300 nm to 400 nm and an integrated light amount of 300 to 3000 mJ / cm ² after application.
The sealant for an organic EL display element of the present invention preferably has a pot life of 1 minute or longer until the curing reaction proceeds after irradiation with light and adhesion cannot be performed. If the pot life is less than 1 minute, curing proceeds before the substrates are bonded together, and sufficient adhesive strength may not be obtained. The pot life can be appropriately adjusted by adjusting the blending amount of the aliphatic hydrocarbon having a hydroxyl group and the curing retarder.

The light source for irradiating the organic EL display element sealant of the present invention with light is not particularly limited. , Microwave-excited mercury lamps, metal halide lamps, sodium lamps, halogen lamps, xenon lamps, fluorescent lamps, sunlight, electron beam irradiation devices, and the like. These light sources may be used independently and 2 or more types may be used together. These light sources are appropriately selected according to the absorption wavelength of the cationic polymerization initiator.

Examples of the light irradiation means to the organic EL display element sealant of the present invention include simultaneous irradiation of various light sources, sequential irradiation with a time difference, combined irradiation of simultaneous irradiation and sequential irradiation, and the like. Any irradiation means may be used.
In curing the encapsulant for organic EL display elements of the present invention, heating may be performed simultaneously with light irradiation in order to further promote photocationic polymerization and further shorten the curing time. Although the heating temperature in the case of performing the said heating is not specifically limited, It is preferable that it is about 50-100 degreeC.

As for the sealing agent for organic EL display elements of this invention, the preferable minimum of the tensile storage elastic modulus in 20 to 80 degreeC of hardened | cured material is 5 * 10 < ⁷ > Pa, and a preferable upper limit is 5 * 10 < ⁸ > Pa. The sealing agent for organic EL display elements of the present invention having a tensile storage elastic modulus in the above range has a substantially constant elastic modulus from the time of heat curing to room temperature in a low elastic region. When used for, the stress is relieved even if curing shrinkage occurs when cooled from room temperature to room temperature, and damage to the organic EL display element is reduced.

A preferred lower limit of the total light transmittance of light at a wavelength of 380 to 800 nm of the cured product of the encapsulant for organic EL display elements of the present invention is 80%. When the total light transmittance is less than 80%, sufficient optical properties may not be obtained when an organic EL display element is produced using the organic EL display element sealant of the present invention. A more preferable lower limit of the total light transmittance is 85%.
The method for measuring the total light transmittance is not particularly limited, and for example, it can be measured using a spectrometer such as “AUTOMATIC HAZE MATER MODEL TC = III DPK” manufactured by Tokyo Denshoku.

In the organic EL display element sealant of the present invention, the lower limit of the transmittance at 400 nm after irradiating the cured product with ultraviolet rays for 100 hours is preferably 85% at an optical path length of 20 μm. If the transmittance after irradiation with the ultraviolet rays for 100 hours is less than 85%, the transparency is low, the loss of light emission is increased, and the color reproducibility may be deteriorated. A more preferable lower limit of the transmittance after irradiation with the ultraviolet rays for 100 hours is 90%, and a more preferable lower limit is 95%.
The method of irradiating the ultraviolet rays is not particularly limited, and a conventionally known light source such as a xenon lamp or a carbon arc lamp can be used.

The sealing agent for organic EL display elements of the present invention has a moisture permeability value of 100 g / m ² or less at a thickness of 100 μm measured by exposing the cured product to 85 ° C. and 85% RH for 24 hours in accordance with JIS Z 0208. Preferably there is. When the moisture permeability exceeds 100 g / m ² , moisture reaches the element and causes dark spots in the light emitting part.

Furthermore, the sealing agent for organic EL display elements of the present invention has a moisture content of less than 0.5% when the cured product is exposed for 24 hours at 85 ° C. and 85% RH. Is preferred. When the moisture content of the cured product is 0.5% or more, the organic EL display element is deteriorated due to moisture in the cured product. A more preferable upper limit of the moisture content of the cured product is 0.3%.

The method for measuring the moisture content is not particularly limited, and examples thereof include a method for obtaining by the Karl Fischer method in accordance with JIS K 7251 and a method for obtaining a weight increment after water absorption in accordance with JIS K 7209-2. Can be mentioned.

By having both the above low moisture permeability and low moisture content, the sealing agent for organic EL display elements of the present invention has excellent moisture resistance.

As for the sealing agent for organic EL display elements of this invention, it is preferable that the glass transition point of the hardened | cured material after hardening is 85 degreeC or more. When the glass transition point of the cured product is less than 85 ° C., the cured product is softened when the organic EL display element is exposed to a high-temperature and high-humidity state, so that water vapor easily passes through the cured product. It causes deterioration of the display element. The minimum with a more preferable glass transition point of the said hardened | cured material is 100 degreeC.

The organic electroluminescence display element using the photocurable resin composition of the present invention or the organic EL display element sealant of the present invention is also one aspect of the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the photocurable resin composition which can obtain the sealing agent for organic electroluminescent display elements which is excellent in transparency and moisture resistance, and is low-viscosity can be provided. Moreover, according to this invention, the sealing compound for organic electroluminescent display elements and organic electroluminescent display element which use this photocurable resin composition can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
50 parts by weight of resorcinol diglycidyl ether (manufactured by Nagase ChemteX Corporation, “Denacol EX-201”) as an epoxy resin represented by the general formula (1), and a hydrogenated bisphenol F type epoxy as an epoxy resin having an aliphatic cyclic skeleton 50 parts by weight of a resin (Mitsubishi Chemical Corporation, “Epicoat YL6753”), 1 part by weight of an iodonium borate-based cationic polymerization initiator (Rhodia, “RP-2074”) as a photocationic polymerization initiator, and a curing retarder As a mixture, 1 part by weight of 18-crown 6 (manufactured by Wako Pure Chemical Industries, Ltd.) was mixed, heated to 80 ° C., and then stirred at a speed of 3000 rpm using a homodisper type stirring mixer (manufactured by Primics, “Homodisper L type”). The mixture was stirred and mixed uniformly to prepare a photocurable resin composition.

(Example 2)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the amount of resorcinol diglycidyl ether was changed to 20 parts by weight and the amount of hydrogenated bisphenol F-type epoxy resin was changed to 80 parts by weight. Produced.

(Example 3)
A photocurable resin composition was prepared in the same manner as in Example 1, except that the amount of resorcinol diglycidyl ether was changed to 80 parts by weight and the amount of hydrogenated bisphenol F-type epoxy resin was changed to 20 parts by weight. Produced.

Example 4
The amount of resorcinol diglycidyl ether was changed to 40 parts by weight, the amount of hydrogenated bisphenol F type epoxy resin was changed to 30 parts by weight, and bisphenol A type epoxy resin (Mitsubishi) was added as an epoxy resin having other aromatic rings. Photocurable resin in the same manner as in Example 1 except that 30 parts by weight of “Epicoat 828” manufactured by Chemical Co., Ltd. and 30 parts by weight of bisphenol F type epoxy resin (“Epicoat 806” manufactured by Mitsubishi Chemical Corporation) were blended. A composition was prepared.

(Example 5)
Except for using 50 parts by weight of a hydrogenated bisphenol F type epoxy resin as an epoxy resin having an aliphatic cyclic skeleton, 50 parts by weight of a hydrogenated biphenyl type epoxy resin (manufactured by Mitsubishi Chemical Corporation, “Epicoat YL7040”) A photocurable resin composition was prepared in the same manner as in Example 1.

(Example 6)
Except for using 50 parts by weight of dicyclopentadiene type epoxy resin (manufactured by ADEKA, “EP-4088”) instead of 50 parts by weight of hydrogenated bisphenol F type epoxy resin as an epoxy resin having an aliphatic cyclic skeleton, A photocurable resin composition was prepared in the same manner as in Example 1.

(Example 7)
Except for using 50 parts by weight of hydroquinone diglycidyl ether (manufactured by Nagase ChemteX Corporation, “Denacol EX-203”) instead of 50 parts by weight of resorcinol diglycidyl ether as the epoxy resin represented by the general formula (1). A photocurable resin composition was prepared in the same manner as in Example 1.

(Example 8)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the blending amount of the hydrogenated bisphenol F type epoxy resin was changed to 180 parts by weight.

Example 9
40 g of 4-ethylresorcinol was dissolved in 100 L of epichlorohydrin and heated to 70 ° C. Next, 40 g of a 48% aqueous sodium hydroxide solution was added dropwise under reduced pressure for 4 hours. The obtained solution was washed three times with water, and then the organic layer was decompressed to obtain 30 g of 4-ethylresorcinol diglycidyl ether (n = 0, R ² = C ₂ H ₅ , R ^{3 to} R ⁵ = H). Obtained.
As in Example 1, except that 50 parts by weight of 4-ethylresorcinol diglycidyl ether obtained was used instead of 50 parts by weight of resorcinol diglycidyl ether as the epoxy resin represented by the general formula (1). Thus, a photocurable resin composition was prepared.

(Example 10)
60 g resornol was dissolved in 100 L epichlorohydrin and heated to 70 ° C. Next, 40 g of a 48% aqueous sodium hydroxide solution was added dropwise under reduced pressure for 4 hours. The obtained solution was washed three times with water, and then the organic layer was depressurized, whereby n = 1, R ^{1 to} R ⁵ = H of the chemical formula (1) as the main components, n = 1, R ¹ to 50 g of a mixture of the compound of R ⁵ = H and the compound of n = 2 and R ^{1 to} R ⁵ = H was obtained.
The photocurable resin composition was the same as in Example 1 except that 50 parts by weight of the obtained mixture was used instead of 50 parts by weight of resorcinol diglycidyl ether as the epoxy resin represented by the general formula (1). A product was made.

(Comparative Example 1)
Except that resorcinol diglycidyl ether was used and 50 parts by weight of a bisphenol A type epoxy resin (Mitsubishi Chemical Co., Ltd., “Epicoat 828”) was blended as an epoxy resin having an aromatic ring, light was used in the same manner as in Example 1. A curable resin composition was prepared.

(Comparative Example 2)
Except that resorcinol diglycidyl ether was not used and 50 parts by weight of bisphenol F type epoxy resin (Mitsubishi Chemical Co., Ltd., “Epicoat 806”) was blended as an epoxy resin having an aromatic ring, light was used in the same manner as in Example 1. A curable resin composition was prepared.

(Comparative Example 3)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the amount of resorcinol diglycidyl ether was changed to 90 parts by weight and the amount of hydrogenated bisphenol F-type epoxy resin was changed to 10 parts by weight. Produced.

(Comparative Example 4)
A photocurable resin composition was prepared in the same manner as in Example 1 except that the amount of resorcinol diglycidyl ether was changed to 15 parts by weight and the amount of hydrogenated bisphenol F-type epoxy resin was changed to 85 parts by weight. Produced.

(Comparative Example 5)
The compounding amount of resorcinol diglycidyl ether was changed to 80 parts by weight, and a bisphenol A type epoxy resin (“Epicoat 828” manufactured by Mitsubishi Chemical Corporation) was used as an epoxy resin having other aromatic rings without using a hydrogenated bisphenol F type epoxy resin. ]) The photocurable resin composition was produced like Example 1 except having mix | blended 20 weight part.

<Evaluation>
The following evaluation was performed about the photocurable resin composition obtained by the Example and the comparative example. The results are shown in Tables 1 and 2.

(1) Measurement of viscosity Photocurable resin compositions obtained in Examples and Comparative Examples using a cone rotor viscometer (manufactured by Toki Sangyo Co., Ltd., “TV-22 type”) at 25 ° C. and 1 rpm. The viscosity of the product was measured.
In addition, since the photocurable resin composition obtained in Comparative Example 5 was crystallized, viscosity measurement and the following evaluation were not performed.

(2) Measurement of moisture permeability The photocurable resin composition produced in Examples and Comparative Examples was applied on a thermostatic plate with a Baker type applicator (manufactured by Tester Sangyo Co., Ltd.) so as to have a thickness of 100 μm. Thereafter, 100 mW / cm ² (365 nm) of light was irradiated for 20 seconds with a high-pressure mercury lamp, and then heated at 80 ° C. for 30 minutes to obtain a film.
The moisture permeability of the obtained film was measured according to JIS Z 0208 by exposing it to conditions of 85 ° C. and 85% RH for 24 hours.

(3) Measurement of light transmittance The photocurable resin compositions produced in the examples and comparative examples were formed to a thickness of 20 μm between two 75 mm × 25 mm × 1 mm glass plates, and a super xenon weather meter SX75 (suga The transmittance at 400 nm after irradiation with ultraviolet rays for 100 hours was measured with a tester company).

(4) Evaluation of light emitting state The photocurable resin compositions produced in Examples and Comparative Examples were evaluated using the organic EL display elements shown below, and the results are shown in Tables 1 and 2.

(Manufacture of organic EL element substrate)
A glass substrate (25 mm × 25 mm × 0.7 mm) formed with an ITO electrode with a thickness of 100 nm was used as a transparent support substrate. The transparent support substrate was ultrasonically washed with acetone, an aqueous alkali solution, ion-exchanged water, and isopropyl alcohol for 15 minutes each, then washed with boiled isopropyl alcohol for 10 minutes, and further UV-ozone cleaner (manufactured by Nippon Laser Electronics Co., Ltd.). , “NL-UV253”).
Next, this transparent support substrate is fixed to the substrate folder of the vacuum deposition apparatus, and 200 mg of N, N′-di (1-naphthyl) -N, N′-diphenylbenzidine (α-NPD) is put in an unglazed crucible. 200 mg of tris (8-hydroxyquinolina) aluminum (Alq ₃ ) was put in an unglazed crucible having different pressures, and the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa. Thereafter, the crucible containing α-NPD was heated and α-NPD was deposited on the substrate at a deposition rate of 15 Å / s to form a 600 正 孔 hole transport layer.
Next, the crucible containing Alq ₃ was heated to form an (Alq ₃ ) film at a deposition rate of 15 Å / s. Thereafter, the transparent support substrate was transferred to another vacuum deposition apparatus, and 200 mg of lithium fluoride was placed in a tungsten resistance heating boat in the vacuum deposition apparatus, and 1.0 g of aluminum wire was placed in another tungsten boat. Thereafter, the pressure in the vacuum chamber was reduced to 2 × 10 ⁻⁴ Pa, and 5 μm of lithium fluoride was formed at a deposition rate of 0.2 Å / s, and then 200 Å of aluminum was formed at a rate of 20 Å / s. The inside of the vapor deposition unit was returned to normal pressure with nitrogen to obtain a transparent support substrate (organic EL element substrate) on which a laminate having an organic light emitting material layer was formed.

(Manufacture of organic EL display elements)
The photocurable resin compositions obtained in Examples and Comparative Examples were applied to the entire surface of a glass back plate to a thickness of 50 μm with a coating apparatus, and ultraviolet rays with a wavelength of 365 nm were irradiated using a high pressure mercury lamp at an irradiation amount of 2000 mJ / Irradiation was performed so as to be cm ² . After this substrate was bonded to the organic EL element substrate in nitrogen, the photocurable resin composition was allowed to stand for 10 minutes to seal the laminate having the organic light emitting material layer.
Subsequently, the photocurable resin composition was cured by heating at 80 ° C. for 30 minutes to produce an organic EL display element.

(Evaluation of light emission state)
The obtained organic EL display element is exposed for 100 hours under conditions of 60 ° C. and 90% RH, and then a voltage of 6 V is applied to change the light emission state of the organic EL display element (light emission and dark spots, presence / absence of pixel peripheral quenching). It observed visually and evaluated by the following reference | standard.
◎: Uniform light emission without dark spots / peripheral quenching ○: Slight decrease in brightness is observed, but there is no dark spot, peripheral quenching, and uniform light emission △: Slight peripheral quenching, or some dark spots are present ×: Remarkable peripheral quenching or dark spots on the entire surface

ADVANTAGE OF THE INVENTION According to this invention, the photocurable resin composition which can obtain the sealing agent for organic electroluminescent display elements which is excellent in transparency and moisture resistance, and is low-viscosity can be provided. Moreover, according to this invention, the sealing compound for organic electroluminescent display elements and organic electroluminescent display element which use this photocurable resin composition can be provided.

Claims (6)

A photocurable resin composition comprising a cationically polymerizable compound and a photocationic polymerization initiator,
The cationically polymerizable compound contains an epoxy resin represented by the following general formula (1) and an epoxy resin having an aliphatic cyclic skeleton,
20-400 weight part of epoxy resins which have the said aliphatic cyclic skeleton are contained with respect to 100 weight part of epoxy resins represented by the said General formula (1), The photocurable resin composition characterized by the above-mentioned.

In formula (1), R ¹ represents a hydrogen atom or a methyl group. R ^{2 to} R ^{5 each} represents a hydrogen atom, a halogen atom, a hydroxyl group, a monovalent linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms. R ^{2 to} R ⁵ may be the same or different. n shows the integer of 0-20. The photocurable resin according to claim 1, wherein the epoxy resin having an aliphatic cyclic skeleton is at least one selected from the group consisting of the following general formulas (2), (3), and (4): Composition.

In formula (2), n represents an integer of 0 to 20. R ⁶ and R ⁷ represent hydrogen or a linear or branched alkyl group having 1 to 12 carbon atoms, and R ⁶ and R ⁷ may be the same as or different from each other.

In formula (3), n represents an integer of 0 to 20. R ^{8 to} R ¹⁵ represent hydrogen or a linear or branched alkyl group having 1 to 12 carbon atoms, and R ^{8 to} R ¹⁵ may be the same as or different from each other.

In formula (4), n represents an integer of 0 to 20. The cationic polymerizable compound is 50 to 200 parts by weight of an epoxy resin having an aromatic ring other than the epoxy resin represented by the general formula (1) with respect to 100 parts by weight of the epoxy resin represented by the general formula (1). The photocurable resin composition according to claim 1, wherein the photocurable resin composition is contained. The photocurable resin composition according to claim 1, 2 or 3, further comprising a curing retarder. A sealant for an organic electroluminescence display device produced using the photocurable resin composition according to claim 1,
A sealing agent for organic electroluminescence display elements, having a viscosity of 10 to 450 mPa · s when measured at 25 ° C. and 1 rpm using a cone rotor viscometer. An organic electroluminescence display element comprising the photocurable resin composition according to claim 1, 2, 3 or 4, and / or the organic electroluminescence display element sealant according to claim 5. .