TW201531556A - Curable resin composition for sealing organic electroluminescent display element, curable resin sheet for sealing organic electroluminescent display element, and organic electroluminescent display element - Google Patents

Abstract

One purpose of this invention is to provide a curable resin composition for sealing an organic electroluminescent display element. Said curable resin composition yields a resin sheet that excels in terms of adhesiveness, transparency, and barrier performance, wherein crack formation due to heating, bending, or the like is prevented. Another purpose of this invention is to provide an organic electroluminescent display element and a curable resin sheet for sealing same obtained using the aforementioned curable resin composition. This invention is a curable resin composition for sealing an organic electroluminescent display element, said curable resin composition containing a polyfunctional cationically polymerizable oligomer, a cationically polymerized polymer having a molecular weight of over 100,000, and a hardener.

Description

Curable resin composition for sealing an organic electroluminescence display element, curable resin sheet for sealing an organic electroluminescence display element, and organic electroluminescence display element

The present invention relates to a curable resin composition for sealing an organic electroluminescence display element, which can prevent occurrence of cracks due to heating or bending, and can obtain a resin sheet excellent in adhesion, transparency, and barrier properties. Moreover, the present invention relates to a curable resin sheet for organic electroluminescence display element sealing and an organic electroluminescence display element which are obtained by using the curable resin composition for sealing an organic electroluminescence display element.

The organic electroluminescence (hereinafter also referred to as "organic EL") display element has a laminate structure in which an organic light-emitting material layer is sandwiched between a pair of opposite electrodes, and the organic light-emitting material layer is injected from an electrode. Electrons are injected into the holes from the other electrode to cause electrons to combine with the holes to emit light in the organic light-emitting material layer. In this way, since the organic EL display element is self-luminous, it has an advantage that it is excellent in visibility and can be made thinner than a liquid crystal display element requiring a backlight device, and can be driven by a DC low voltage.

The organic light-emitting material layer or the electrode constituting the organic EL display element has a problem that the characteristics are easily deteriorated by moisture, oxygen, or the like. Therefore, in order to obtain a practical organic EL display element, it is necessary to cut off the organic light-emitting material layer or the electrode from the atmosphere to achieve a long life. As will A method of blocking an organic light-emitting material layer or an electrode from the atmosphere is a method of sealing an organic EL display element using a sealant (for example, Patent Document 1). When the organic EL display element is sealed with a sealant, a method in which an inorganic film called a passivation film is provided on a laminate having an organic light-emitting material layer is generally used in order to sufficiently suppress the permeation of moisture or oxygen. The sealant is used to seal the inorganic film.

On the other hand, in recent years, as a form of a novel display, a flexible display which can be deformed into a curved shape has been developed. Such a flexible display is obtained by fabricating an organic EL display element by using a transparent substrate made of heat-resistant plastic or an extremely thin glass substrate instead of a conventional glass substrate. It is believed that the use of such a flexible substrate will also revolutionize the manufacturing process. That is, since a simpler roll bonding can be used instead of the vacuum bonding technique which is often used in the bonding of a conventional rigid substrate, the simplification of the manufacturing process or the shortening of the tact time can be expected.

On the other hand, the materials used in the prior art are also innovated. As for the sealant, if it is a conventional liquid sealant, there is a problem in that when the roll is attached, the remaining sealant overflows to the periphery and is contaminated. In the case of damage to the device, or the entrapment of air bubbles or the difficulty in obtaining the uniformity of the thickness of the sealant layer, a sheet-like sealing material is sought. However, in the case where the conventional sealant is used in the form of a sheet, there is a problem that cracks occur during heating in the production step or when the roll is bonded or used.

Patent Document 1: Japanese Laid-Open Patent Publication No. 2007-115692

It is an object of the present invention to provide an organic electroluminescent display element for sealing The curable resin composition can prevent the occurrence of cracks due to heating or bending, and can obtain a resin sheet excellent in adhesion, transparency, and barrier properties. Moreover, an object of the present invention is to provide a curable resin sheet for organic electroluminescence display element sealing and an organic electroluminescence display element which are obtained by using the curable resin composition for sealing an organic electroluminescence display element.

The present invention relates to a curable resin composition for sealing an organic electroluminescence display element, which comprises a polyfunctional cationically polymerizable oligomer, a cationically polymerizable polymer having a molecular weight of more than 100,000, and a curing agent.

Hereinafter, the present invention will be described in detail.

In order to prevent the occurrence of cracks due to heating or bending, the inventors of the present invention have studied a resin which is relatively excellent in flexibility such as a thermoplastic resin for a sealing material. However, in the case of using such a resin, there is a problem that the barrier property (water permeability resistance) of the obtained cured product is deteriorated.

Therefore, the inventors of the present invention have conducted an effort to obtain a curable resin composition for an organic EL display device by using a polyfunctional cationically polymerizable oligomer in combination with a specific cationic polymerizable polymer. This can prevent the occurrence of cracks due to heating or bending, and can obtain a resin sheet excellent in adhesion, transparency, and barrier properties, thereby completing the present invention.

The curable resin composition for sealing an organic EL display element of the present invention contains a polyfunctional cationically polymerizable oligomer.

The polyfunctional cationically polymerizable oligomer is an oligomer having two or more cationically polymerizable groups in one molecule, and functions as a plasticizer for the cationically polymerizable polymer, and exhibits a flow due to heating. Subsequent, and imparted by cross-linking hardening by cationic polymerization The effect of firm adhesion and barrier properties. The above "oligomer" means a monomer which is a polymerizable monomer and a compound which polymerizes the monomer at a low degree of polymerization.

The cationically polymerizable group which the polyfunctional cationically polymerizable oligomer has is exemplified by an epoxy group, an oxetanyl group, and the like. Among them, an epoxy group is preferred.

In addition, the polyfunctional cationically polymerizable oligomer preferably has one or more cyclic structures in the molecule, and examples of the cyclic structure include an aromatic compound and an alicyclic compound.

A preferred lower limit of the cationically polymerizable group equivalent of the above polyfunctional cationically polymerizable oligomer is 50 g/mol, and a preferred upper limit is 400 g/mol. When the cationically polymerizable base equivalent of the polyfunctional cationically polymerizable oligomer is less than 50 g/mol, the cured product of the curable resin composition for sealing an organic EL display element obtained is cracked by heating or deformation. Happening. When the cationically polymerizable group equivalent of the polyfunctional cationically polymerizable oligomer is more than 400 g/mol, the cured product of the curable resin composition for sealing an organic EL display element obtained may be inferior in barrier properties. A more preferred lower limit of the cationically polymerizable group equivalent of the above polyfunctional cationically polymerizable oligomer is 70 g/mol, and a more preferred upper limit is 300 g/mol.

Further, the weight (g) of the cationically polymerizable group-based polyfunctional cationically polymerizable oligomer of the above polyfunctional cationically polymerizable oligomer is divided by the cationically polymerizable group contained in the polyfunctional cationically polymerizable oligomer. The value obtained by the molar number (mol).

A preferred lower limit of the molecular weight of the above polyfunctional cationically polymerizable oligomer is 150, and a preferred upper limit is 7,000. When the molecular weight of the above polyfunctional cationically polymerizable oligomer is less than 150, it is a cause of outgassing. When the molecular weight of the above polyfunctional cationically polymerizable oligomer exceeds 7,000, the effect of the plasticizer for the cationically polymerizable polymer becomes insufficient. The case where the flow continuity due to heating is lowered. The lower limit of the molecular weight of the above polyfunctional cationically polymerizable oligomer is preferably 200, more preferably the upper limit is 5,000, and the lower limit is preferably 250, and further preferably the upper limit is 1000, and the upper limit is preferably 600.

Further, regarding the molecular weight of the polyfunctional cationically polymerizable oligomer, a compound having a specific molecular structure is a molecular weight determined by a structural formula, and a compound having a wide distribution of polymerization degree and a compound having a modified portion are not particularly useful. The average molecular weight is used to indicate the situation. In the present specification, the above "weight average molecular weight" is measured by gel permeation chromatography (GPC) and is determined by polystyrene conversion. For example, Shodex LF-804 (manufactured by Showa Denko KK) can be used as the column to be used for the measurement of the weight average molecular weight by the GPC.

Examples of the polyfunctional cationically polymerizable oligomer include a bisphenol A skeleton, a bisphenol F skeleton, a hydrogenated bisphenol A skeleton, a hydrogenated bisphenol F skeleton, a phenol novolak skeleton, a biphenyl skeleton, and a hydrogenated biphenyl. Skeleton, dicyclopentadiene skeleton, naphthalene skeleton, three An oligomer such as a skeleton. Among them, the moisture absorption rate of moisture absorption or water vapor can be lowered, and the deterioration of the light emission of the obtained organic EL display element can be further suppressed, and it is preferable to have a hydrogenated bisphenol A skeleton, a hydrogenated bisphenol F skeleton, and two An oligomer of an alicyclic skeleton such as a cyclopentadiene skeleton. In addition, by using an oligomer having an alicyclic skeleton as the polyfunctional cationically polymerizable oligomer, it is difficult to cause coloring of the curable resin composition due to heat or light, and the curable resin can be reduced. The loss of EL luminescence or the change in hue caused by the absorption of the composition. These polyfunctional cationically polymerizable oligomers may be used singly or in combination of two or more kinds.

The oligomer having the above alicyclic skeleton is not particularly limited as long as it has an alicyclic skeleton and two or more cationically polymerizable groups in the structure, and may be in the structure. Or a compound having only one of the above alicyclic skeletons in a repeating unit, or a compound having two or more alicyclic skeletons in a repeating unit, but more preferably having two or more alicyclic rings in a repeating unit. a compound of the skeleton. When the epoxy compound having the alicyclic skeleton is a compound having two or more alicyclic skeletons in a repeating unit, the curable resin composition for sealing an organic EL display element of the present invention has light resistance and moisture resistance. More excellent.

As a commercial product of the oligomer having the above alicyclic skeleton, for example, jER YX8034, jER YL6753 (all manufactured by Mitsubishi Chemical Corporation), EPICLON HP7200L (manufactured by DIC Corporation), and DME-100 (New Japan Physical and Chemical Industry Co., Ltd.) are mentioned. Manufacturing), EP-4085 (manufactured by Adeka), CELLOXIDE 3000, EHPE 3150 (all manufactured by Daicel), and the like.

Further, the polyfunctional cationically polymerizable oligomer preferably has an epoxy group or an oxetanyl group, and does not have an ether bond other than the epoxy group or the oxetanyl group, and an ether other than the ester bond. A compound of a bond and an ester bond. By using such a compound, the generation of outgas can be suppressed.

Examples of the compound having an epoxy group or an oxetanyl group and having no ether bond other than the epoxy group or the oxetanyl group, and an ether bond other than the ester bond, and an ester bond are as follows. The compound represented by the formula (1), the compound represented by the following formula (2), and the like can be easily adjusted in terms of the hardening retardation or the viscosity of the curable resin composition for sealing an organic EL display device obtained. Preferably, the compound represented by the formula (1) and the compound represented by the formula (2) are contained.

In the formula (1), R ¹ to R ¹⁸ are a hydrogen atom, a halogen atom, or a hydrocarbon group which may contain an oxygen atom or a halogen atom, and may be the same or different.

In the formula (2), R ¹⁹ to R ²¹ are a linear or branched alkylene group having 2 to 10 carbon atoms, which may be the same or different. E ¹ to E ³ each independently represent an organic group represented by the following formula (3-1) or the following formula (3-2).

In the formula (3-1), R ²² is a hydrogen atom or a methyl group. In the formulas (3-1) and (3-2), * represents a bonding key.

The compound represented by the above formula (1) is preferably a compound represented by the following formula (4) from the viewpoint of exhibiting good cation hardenability.

The compound represented by the above formula (2) exhibits good cationic hardenability, and the compound represented by the following formula (5) is preferred from the viewpoint of exhibiting a high glass transition temperature of the cured product.

The curable resin composition for sealing an organic EL display element of the present invention contains a cationically polymerizable polymer.

The curable resin composition for sealing an organic EL display device of the present invention is particularly excellent in bending resistance and barrier properties by containing the above-mentioned cationically polymerizable polymer.

Examples of the cationically polymerizable group which the cationically polymerizable polymer has Examples thereof include an epoxy group and an oxetanyl group. Among them, an epoxy group is preferred.

The upper limit of the cationically polymerizable group equivalent of the above cationically polymerizable polymer is preferably 3,000 g/mol. When the cationically polymerizable group equivalent of the above cationically polymerizable polymer is more than 3,000 g/mol, the obtained curable resin composition for sealing an organic EL display device may have poor barrier properties to the adhesive or cured product. The upper limit of the more preferable cationically polymerizable base equivalent of the above cationically polymerizable polymer is 2000 g/mol.

Further, a preferred lower limit of the cationically polymerizable group equivalent of the cationically polymerizable polymer is 200 g/mol. When the cationically polymerizable base equivalent of the above cationically polymerizable polymer is less than 200 g/mol, the cured product of the curable resin composition for sealing an organic EL display element obtained may be cracked by heating or deformation. A more preferred lower limit of the cationically polymerizable group equivalent of the above cationically polymerizable polymer is 300 g/mol.

In addition, the weight (g) of the cationically polymerizable group-based cationically polymerizable polymer of the cationically polymerizable polymer is divided by the number of moles (mol) of the cationically polymerizable group contained in the cationically polymerizable polymer. The value.

The molecular weight of the above cationically polymerizable polymer exceeds 100,000. When the molecular weight of the above-mentioned cationically polymerizable polymer is 100,000 or less, the cured product of the curable resin composition for sealing an organic EL display element obtained is cracked by heating or deformation.

Further, the upper limit of the molecular weight of the above cationically polymerizable polymer is preferably 500,000. When the molecular weight of the above-mentioned cationically polymerizable polymer is more than 500,000, the curable resin composition for sealing an organic EL display element obtained may be inferior in coatability. The upper limit of the molecular weight of the above cationically polymerizable polymer is preferably 300,000.

Further, the molecular weight of the above cationically polymerizable polymer is expressed by weight average molecular weight. Show.

Examples of the cationically polymerizable polymer include an epoxy resin such as a bisphenol A epoxy resin, a bisphenol F epoxy resin, another phenoxy resin, and a novolac epoxy resin, or an alkyl (meth)acrylate. A base-glycidyl (meth)acrylate copolymer, a styrene-glycidyl (meth)acrylate copolymer, and the like. In the case where the resin sheet obtained by using the curable resin composition for sealing an organic EL display element obtained is excellent in film strength, it is preferable to have an epoxy group in a side chain, and it is more preferable ( Alkyl methacrylate-glycidyl methacrylate copolymer, styrene-glycidyl methacrylate copolymer.

The commercially available ones of the above-mentioned cationically polymerizable polymers include, for example, MARPROOF G-1010S and MARPROOF G-2050M (all manufactured by Nippon Oil Co., Ltd.).

The content of the cationically polymerizable polymer is preferably 20 parts by weight, and preferably 200 parts by weight, based on 100 parts by weight of the polyfunctional cationically polymerizable oligomer. When the content of the above-mentioned cationically polymerizable polymer is less than 20 parts by weight, when the resin sheet is formed using the curable resin composition for sealing an organic EL display element obtained, the surface viscosity before curing is large, and workability is lowered. The situation. When the content of the above-mentioned cationically polymerizable polymer is more than 200 parts by weight, in order to obtain sufficient adhesion, it is necessary to heat the organic EL display element at a high temperature to deteriorate the organic light-emitting material layer or the like. A more preferred lower limit of the content of the above cationically polymerizable polymer is 50 parts by weight, more preferably 150 parts by weight, still more preferably 70 parts by weight, and still more preferably 120 parts by weight.

The curable resin composition for sealing an organic EL display element of the present invention contains a curing agent. As the above curing agent, a cationic polymerization initiator and/or a thermal curing agent can be used.

As the above cationic polymerization initiator, a thermal cationic polymerization initiator which starts a curing reaction by heat or a photocationic polymerization initiator which starts a curing reaction by light can be used. Among them, as the curing agent, a thermal cationic polymerization initiator is preferably contained.

Examples of the thermal cationic polymerization initiator include a phosphonium salt, a phosphonium salt, a quaternary ammonium salt, a diazonium salt, and a phosphonium salt. Among them, a phosphonium salt is preferred.

Examples of the counter anion in the thermal cationic polymerization initiator include AsF ₆ ^- , SbF ₆ ^- , PF ₆ ^- , (BX ₄ ) ^- (wherein X represents at least 2 or more fluorine or trifluoromethyl groups) Substituted phenyl) and the like.

Examples of the onium salt include triphenylsulfonium tetrafluoride, triphenylsulfonium hexafluoride, triphenylsulfonium hexafluoride, and tris(4-methoxyphenyl)phosphonium hexafluoride. Diphenyl (4-phenylthiophenyl) ruthenium hexafluoride or the like.

Examples of the onium salt include ethyltriphenylphosphonium hexafluoride, tetrabutylphosphonium hexafluoride, and the like.

Examples of the above quaternary ammonium salt include dimethylphenyl (4-methoxybenzyl) ammonium hexafluorophosphate and dimethylphenyl (4-methoxybenzyl) ammonium hexafluoroantimonate. , dimethylphenyl (4-methoxybenzyl) ammonium tetrakis(pentafluorophenyl) borate, dimethylphenyl (4-methylbenzyl) ammonium hexafluorophosphate, dimethylphenyl (4-methylbenzyl)ammonium hexafluoroantimonate, dimethylphenyl (4-methylbenzyl) ammonium hexafluorotetrakis(pentafluorophenyl)borate, methylphenyl dibenzylammonium, Methylphenyl dibenzylammonium hexafluoroantimonate hexafluorophosphate, methylphenyl dibenzylammonium tetrakis(pentafluorophenyl)borate, phenyltribenzylammonium tetrakis(pentafluorophenyl)borate Salt, dimethylphenyl (3,4-dimethylbenzyl) ammonium tetrakis(pentafluorophenyl)borate, N,N-dimethyl-N-benzylaniline ruthenium hexafluoride, N, N-Diethyl-N-benzylaniline bismuth tetrafluoroborate, N,N-dimethyl-N-benzylpyridinium ruthenium hexafluoride, N,N-diethyl-N-benzylpyridinium Triflate, N, N-di Methyl-N-(4-methoxybenzyl)pyridinium ruthenium hexafluoride, N,N-diethyl-N-(4-methoxybenzyl)pyridinium ruthenium hexafluoride, N,N -Diethyl-N-(4-methoxybenzyl)toluidine antimony hexafluoride, N,N-dimethyl-N-(4-methoxybenzyl)toluidine antimony hexafluoride Wait.

As a commercial one of the above-mentioned thermal cationic polymerization initiators, for example, ADEKA OPTON CP-66, ADEKA OPTON CP-77 (all manufactured by ADEKA Co., Ltd.); or a thermal cation having photoactivity not only having thermal activity but also being photoactive Polymerization initiators San-Aid SI-60, San-Aid SI-80, San-Aid SI-100, San-Aid SI-110, San-Aid SI-180, San-Aid SI-B3A, San-Aid SI-B4 (all manufactured by Sanshin Chemical Industry Co., Ltd.); K-PURE CXC-1612, K-PURE CXC-1738, K-PURE CXC-1821 (all manufactured by King Industries), and the like.

The photocationic polymerization initiator is not particularly limited as long as it is a protonic acid or a Lewis acid by light irradiation, and may be an ionic photoacid generation type or a nonionic photoacid generation type.

Among them, the sealant for an organic electroluminescence display device is preferably a ruthenium complex having a phosphorus hexafluoride ion in terms of particularly excellent adhesion to nickel-plated Cu glass or alkali-free glass. The salt or the salt represented by the following formula (6).

In the formula (6), n represents an integer of 1 to 12, m represents an integer of 1 to 5, and Rf represents a fluoroalkyl group in which all or a part of hydrogen of the alkyl group is substituted by fluorine.

The above hydrazine complex is not particularly limited, and is preferably a phosphonium salt.

Specific examples of the onium salt of the above-mentioned ruthenium complex include tetraphenyl (diphenyl sulfide-4,4'-diyl)difluorene-bis(ruthenium hexafluoride) and tetrakis(4-methyl). Oxyphenyl)[diphenyl sulfide-4,4'-diyl]diindole-bis(phosphonium hexafluoride), diphenyl(4-phenylthiophenyl)fluorene-ruthenium hexafluoride, Bis(4-methoxyphenyl)[4-phenylthiophenyl]anthracene-ruthenium hexafluoride or the like.

For example, ADEKA OPTOMER SP170 (manufactured by Adeka Co., Ltd.) or the like can be mentioned as a commercially available product of the above-mentioned oxime complex.

Examples of the salt having a phosphorus hexafluoride ion include diphenylphosphonium hexafluorophosphate and triphenylsulfonium hexafluorophosphate. The commercially available ones of the above-mentioned salts having a phosphorus hexafluoride ion include, for example, WPI-113 (manufactured by Wako Pure Chemical Industries, Ltd.), CPI-100P (manufactured by SAN-APRO Co., Ltd.), and the like.

The commercially available ones of the salts represented by the above formula (6) include, for example, CPI-200K and CPI-210S (all manufactured by SAN-APRO Co., Ltd.).

The content of the cationic polymerization initiator is preferably 0.1 parts by weight, and preferably 10 parts by weight, based on 100 parts by weight of the total of the polyfunctional cationically polymerizable oligomer and the cationically polymerizable polymer. When the content of the cationic polymerization initiator is less than 0.1 part by weight, the curing reaction of the curable resin composition for sealing an organic EL display element obtained may not be sufficiently performed. When the content of the cationic polymerization initiator is more than 10 parts by weight, the obtained curable resin composition for sealing an organic EL display element may be colored or may have poor storage stability. More of the above cationic polymerization initiator The lower limit is preferably 0.5 parts by weight, and more preferably the upper limit is 5 parts by weight.

In the case where the photocationic polymerization initiator is used as the curing agent, it is preferred to contain a sensitizer comprising a benzophenone derivative represented by the following formula (7). The sensitizer has an effect of further enhancing the polymerization initiation efficiency of the photocationic polymerization initiator and appropriately promoting the curing reaction of the curable resin composition for sealing an organic EL display device of the present invention.

In the formula (7), R ²³ and R ²⁴ represent hydrogen, a substituent represented by the following formula (8-1), or a substituent represented by the following formula (8-2). The above R ²³ and R ²⁴ may be the same or different from each other.

In the formulae (8-1) and (8-2), R ²⁵ represents hydrogen, a linear or branched alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a halogen atom, or a hydroxyl group. A carboxyl group or a carboxylate group having 1 to 20 carbon atoms.

Specific examples of the benzophenone derivative represented by the above formula (7) Examples thereof include benzophenone, 2,4-dichlorobenzophenone, methyl phthalic acid benzoate, 4,4'-bis(dimethylamino)benzophenone, and 4-benzylformamide. Base-4'-methyldiphenyl sulfide and the like.

The content of the sensitizer is preferably 0.05 parts by weight, and preferably the upper limit is 3 parts by weight, based on 100 parts by weight of the total of the polyfunctional cationically polymerizable oligomer and the cationically polymerizable polymer. If the content of the sensitizer is less than 0.05 part by weight, the sensitizing effect may not be sufficiently obtained. When the content of the sensitizer exceeds 3 parts by weight, the absorption may become too large, and light may not be transmitted to the deep portion. A more preferred lower limit of the content of the above sensitizer is 0.1 part by weight, and a more preferred upper limit is 1 part by weight.

The thermosetting agent starts to harden the polyfunctional cationically polymerizable oligomer and the cationically polymerizable polymer by heating, and has a function of promoting hardening.

Examples of the above-mentioned thermosetting agent include an anthracene compound, an imidazole derivative, a secondary amine compound, a tertiary amine compound, an acid anhydride, a dicyandiamide, an anthracene derivative, a modified aliphatic polyamine, various amines and an epoxy resin. Addition products, etc.

These thermosetting agents may be used singly or in combination of two or more.

Examples of the ruthenium compound include 1,3-bis(decylcarbonylethyl-5-isopropylhydantoin).

Examples of the above imidazole derivative include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, and 2-ethyl-4-methylimidazole. , 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methyl Imidazole compound such as imidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, or 2-A Imidazolines such as imidazoline and 2-phenylimidazoline, or imidazole derivatives such as 1-cyanoethyl-2-undecylimidazolium trimellitate and epoxy-imidazole adduct.

Examples of the secondary amine compound include piperidine and the like.

As the above tertiary amine compound, for example, N,N-dimethylperidine can be cited. And triethylenediamine, benzyldimethylamine, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, and the like.

Examples of the acid anhydride include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylic acid anhydride, methylhexahydrophthalic anhydride, hydrogenated methylic acid anhydride, and ethylene. Alcohol-bis (dehydrated trimellitate) and the like. Among them, an alicyclic acid anhydride containing no double bond is preferred.

A preferred lower limit of the molecular weight of the above thermal hardener is 80, and a preferred upper limit is 800. If the molecular weight of the above-mentioned thermosetting agent is less than 80, the volatility becomes high and the outgassing occurs. When the molecular weight of the above-mentioned thermosetting agent is more than 800, the fluidity of the curable resin composition for sealing an organic EL display element is thermally pressure-bonded to the element, or the diffusibility in the composition is lowered, and sufficient hardenability cannot be obtained. The situation. A lower limit of the molecular weight of the above-mentioned thermosetting agent is preferably 100, more preferably 500, and further preferably a lower limit of 120, and further preferably an upper limit of 250.

In the case where a thermal curing agent is used as the curing agent, the content of the thermal curing agent is preferably 100 parts by weight based on 100 parts by weight of the total of the polyfunctional cationically polymerizable oligomer and the cationically polymerizable polymer. Preferably, the upper limit is 10 parts by weight. When the content of the above-mentioned thermosetting agent is less than 0.1 part by weight, the obtained curable resin composition for sealing an organic EL display element may not be sufficiently thermally cured. When the content of the above-mentioned thermosetting agent is more than 10 parts by weight, the obtained curable resin composition for sealing an organic EL display element may be inferior in storage stability. A more preferred lower limit of the content of the above-mentioned thermosetting agent is 0.5 part by weight, and a more preferred upper limit is 5 parts by weight.

Further, in the case where the above acid anhydride is used as the above-mentioned heat hardener, the above acid anhydride is blended The amount is preferably 50 parts by weight, and preferably 150 parts by weight, based on 100 parts by weight of the total of the above polyfunctional cationically polymerizable oligomer and the above cationically polymerizable polymer.

In the case where the above-mentioned acid anhydride is used as the above-mentioned heat curing agent, the curable resin composition for sealing an organic EL display element of the present invention may further contain a curing accelerator.

Examples of the curing accelerator include a quaternary ammonium salt, a quaternary phosphonium salt, a DBU fatty acid salt, various metal salts, imidazole, and a tertiary amine.

Examples of the quaternary ammonium salt include tetramethylammonium bromide and tetrabutylammonium bromide.

Examples of the above-mentioned quaternary phosphonium salt include tetraphenylphosphonium bromide and tetrabutylphosphonium bromide.

Examples of the DBU fatty acid salt include 2-ethylhexanoic acid salt of DBU.

Examples of the metal salt include zinc octoate and tin octylate.

Examples of the imidazole include 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, and 2-ethyl-4-methylimidazole.

Examples of the tertiary amine include tris(dimethylaminomethyl)phenol and benzyldimethylamine.

The content of the curing accelerator is preferably 10 parts by weight based on 100 parts by weight of the total of the polyfunctional cationically polymerizable oligomer and the cationically polymerizable polymer. By adding a hardening accelerator so that the content is 10 parts by weight or less, the curing temperature in the case where the above-mentioned acid anhydride is used as the above-mentioned heat curing agent can be appropriately adjusted.

The curable resin composition for sealing an organic EL display element of the present invention preferably contains a decane coupling agent. The decane coupling agent has an effect of improving the adhesion between the curable resin composition for sealing an organic EL display element of the present invention and the adherend.

The above decane coupling agent preferably has a cationically polymerizable group.

The preferred cationically polymerizable group of the above decane coupling agent may, for example, be an epoxy group or an oxetanyl group.

Examples of the decane coupling agent having the above cationically polymerizable group include 3-glycidoxypropyltrimethoxydecane, 3-glycidoxypropylmethyldimethoxydecane, and 2-(3). , 4-epoxycyclohexyl)ethyltrimethoxydecane, 3-ethyl-((triethoxydecylpropoxy)methyl)oxetane, and the like. Among them, 3-glycidoxypropyltrimethoxydecane is preferred from the viewpoint of compatibility or stability with the above polyfunctional cationically polymerizable oligomer or the above cationically polymerizable polymer. These decane coupling agents may be used singly or in combination of two or more.

The content of the decane coupling agent is preferably 0.1 parts by weight, and preferably 5 parts by weight, based on 100 parts by weight of the total of the polyfunctional cationically polymerizable oligomer and the cationically polymerizable polymer. When the content of the above-mentioned decane coupling agent is less than 0.1 part by weight, the effect of improving the adhesion of the curable resin composition for sealing an organic EL display element obtained by the above may not be sufficiently exhibited. When the content of the above-mentioned decane coupling agent exceeds 5 parts by weight, the cured product of the curable resin composition for sealing an organic EL display element obtained has a poor barrier property due to a decrease in crosslinking density, or the remaining decane coupling agent bleeds out. . A more preferred lower limit of the content of the above decane coupling agent is 0.3 parts by weight, and a more preferred upper limit is 2 parts by weight.

The curable resin composition for sealing an organic EL display element of the present invention may further contain a surfactant. By including the above-mentioned surfactant, the flatness after application of the curable resin composition for sealing an organic EL display element of the present invention into a sheet shape can be further improved.

Examples of the above surfactant include an antifoaming agent, a leveling agent, and the like.

Examples of the surfactant include fluorine-based, anthrone-based, and acrylic acid. A surfactant such as a surfactant. Among them, a fluorine-based surfactant and an anthrone-based surfactant are preferable, and a fluorine-based surfactant is more preferable.

The fluorine-based surfactant can be preferably used as a compound having a fluoroalkyl group or a fluoroalkyl group in at least a part of a terminal, a main chain, and a side chain. Specifically, for example, 1, 1, 2 can be mentioned. , 2-tetrafluorooctyl (1,1,2,2-tetrafluoropropyl)ether, 1,1,2,2-tetrafluorooctylhexyl ether, octaethylene glycol di(1,1,2, 2-tetrafluorobutyl)ether, hexaethylene glycol (1,1,2,2,3,3-hexafluoropentyl)ether, octapropylene glycol bis(1,1,2,2-tetrafluorobutyl) Ether, hexapropylene glycol bis(1,1,2,2,3,3-hexafluoropentyl)ether, sodium perfluorododecyl sulfonate, 1,1,2,2,8,8,9,9 , 10,10-decafluorododecane, 1,1,2,2,3,3-hexafluorodecane, sodium fluoroalkylbenzenesulfonate, sodium fluoroalkylphosphonate, sodium fluoroalkylcarboxylate, Fluoroalkyl polyoxyethylene ether, diglycerol tetrakis(fluoroalkyl polyoxyethylene ether), fluoroalkyl ammonium iodide, fluoroalkyl betaine, fluoroalkyl polyoxyethylene ether, perfluoroalkyl polyoxyethylene, Perfluoroalkyl alkoxide, fluoroalkyl ester, and the like.

Further, as a commercially available one of the fluorine-based surfactants, for example, BM-1000, BM-1100 (above, BM HEMIE), MEGAFAC F142D, MEGAFAC F172, MEGAFAC F173, MEGAFAC F183, MEGAFAC F178, MEGAFAC F191, MEGAFAC F471, MEGAFAC F476 (above DIC), FLUORAD FC170C, FC-171, FC-430, FC-431 (above is Sumitomo 3M), SURFLON S-112, SURFLON S-113, SURFLON S -131, SURFLON S-141, SURFLON S-145, SURFLON S-382, SURFLON SC-101, SURFLON SC-102, SURFLON SC-103, SURFLON SC-104, SURFLON SC-105, SURFLON SC-106 (above Manufactured by Asahi Glass Co., Ltd., EFTOP EF301, EFTOP EF303, EFTOP EF352 (above is manufactured by Mitsubishi Materials Electronic Chemicals), FTERGENT FT-100, FTERGENT FT-110, FTERGENT FT-140A, FTERGENT FT-150, FTERGENT FT-250, FTERGENT FT-251, FTERGENT FTX-251, FTERGENT FTX-218, FTERGENT FT-300, FTERGENT FT-310, FTERGENT FT-400S (above manufactured by Neos).

Further, as the above-mentioned anthrone-based surfactant, a polyether-modified polydimethylsiloxane or a polyester-modified polydimethyloxane is more preferable, and a polyether-modified polydimethyl group is further preferred. Oxane.

As a commercial one of the above-mentioned anthrone-based surfactants, for example, BYK-354, BYK-300, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315, BYK can be cited. -320, BYK-322, BYK-323, BYK-325, BYK-330, BYK-331, BYK-333, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349 , BYK-370, BYK-378, BYK-3455 (above is BYK-Chemie Japan), SURFLON S-611 (manufactured by AGC SEIMI CHEMICAL), TORAY SILICONE DC3PA, TORAY SILICONE DC7PA, TORAY SILICONE SH11PA, TORAY SILICONE SH21PA , TORAY SILICONE SH28PA, TORAY SILICONE SH29PA, TORAY SILICONE SH30PA, TORAY SILICONE SH-190, TORAY SILICONE SH-193, TORAY SILICONE SZ-6032, TORAY SILICONE SF-8428, TORAY SILICONE DC-57, TORAY SILICONE DC-190 (above) It is manufactured by Dow Corning Toray Co., Ltd., TSF-4440, TSF-4300, TSF-4445, TSF-4446, TSF-4460, TSF-4452 (above, manufactured by Momentive Performance Materials Japan Co., Ltd.) and the like.

Further, as the surfactant, for example, polyoxyethylene alkyl ether such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether or polyoxyethylene oleyl ether, or polyoxyethylene can be used. A polyoxyethylene aryl ether such as octyl phenyl ether or polyoxyethylene n-decyl phenyl ether; or a polyoxyethylene dialkyl ester such as polyoxyethylene dilaurate or polyoxyethylene distearate.

These surfactants may be used singly or in combination of two or more.

The content of the surfactant is preferably 0.01 parts by weight, and preferably the upper limit is 5 parts by weight, based on 100 parts by weight of the total of the polyfunctional cationically polymerizable oligomer and the cationically polymerizable polymer. When the content of the surfactant is less than 0.01 part by weight, the effect of improving the flatness after coating may not be sufficiently exhibited. When the content of the surfactant is more than 5 parts by weight, the flatness after coating may be impaired, or the adhesion between the curable resin composition for sealing an organic EL display element of the present invention and the adherend may be lowered. The content of the surfactant is preferably 0.02 parts by weight, more preferably 1 part by weight, based on the fluorine-based surfactant. Further, in the case of an anthrone-based surfactant, a lower limit is preferably 0.1 part by weight, and a more preferred upper limit is 2 parts by weight.

The curable resin composition for sealing an organic EL display element of the present invention may contain a filler insofar as the object of the present invention is not impaired.

Examples of the filler include talc, asbestos, silica, diatomaceous earth, smectite, bentonite, calcium carbonate, magnesium carbonate, aluminum oxide, montmorillonite, and magnesium oxide. Inorganic fillers such as titanium oxide, magnesium hydroxide, aluminum hydroxide, glass beads, barium sulfate, gypsum, calcium silicate, sericite, activated clay, or polyester microparticles, polyurethane microparticles, ethylene polymer microparticles, acrylic acid An organic filler such as polymer microparticles.

The curable resin composition for sealing an organic EL display element of the present invention may be contained in order to improve the durability of the element electrode without impairing the object of the present invention. A compound or ion exchange resin in which an acid generated in a curable resin composition for a device EL is reacted.

Examples of the compound which reacts with the generated acid include a substance neutralized with an acid, and examples thereof include an alkali metal carbonate or hydrogencarbonate, or an alkaline earth metal carbonate or hydrogencarbonate. Specifically, for example, calcium carbonate, calcium hydrogencarbonate, sodium carbonate, sodium hydrogencarbonate or the like can be used.

The curable resin composition for sealing an organic EL display element of the present invention preferably contains a hardening retarder. The above hardening retarder has an effect of improving storage stability or controlling the usable time and hardening time.

As the hardening retarder, an amine compound, a compound having an ether bond, or the like can be used.

Examples of the amine compound include a primary amine compound such as benzylamine, methylamine, ethylamine, n-butylamine or isobutylamine; a secondary amine compound such as diethylamine or diphenylamine; A tertiary amine compound such as ethylamine or triisopropanolamine.

Examples of the compound having an ether bond include a chain polyether such as polyethylene glycol, polypropylene glycol or polytetramethyl glycol, or a 12-crown 4-ether and a 15-crown. 5-Ether, 18-crown 6-ether, 24-crown 8-ether, dicyclohexanone-18-crown 6-ether, dibenzo-18-crown 6-ether, 2-(hydroxymethyl)-18 - crown 6-ether, 2-(allyloxymethyl)-18-crown 6-ether, benzo-18-crown 6-ether, 4'-acetamidobenzo-18-crown 6-ether, A cyclic polyether such as N,N'-dibenzyl-4,13-diaza-18-crown-6-ether.

Among them, a benzylamine is preferred.

The content of the hardening retarder is preferably 0.1 parts by weight, and preferably the upper limit is 5 parts by weight, based on 100 parts by weight of the total of the polyfunctional cationically polymerizable oligomer and the cationically polymerizable polymer. If the content of the hardening retarder is less than 0.1 weight In some cases, there is a case where the retardation effect of the curable resin composition for sealing of the organic EL display element obtained is not sufficiently provided. When the content of the hardening retarder is more than 5 parts by weight, a large amount of outgassing may occur when the obtained curable resin composition for sealing an organic EL display element is cured. A more preferred lower limit of the content of the above hardening retarder is 0.5 part by weight, and a more preferred upper limit is 3 parts by weight.

As the ion exchange resin, any of a cation exchange type, an anion exchange type, and a two ion exchange type can be used, and a cation exchange type or a two ion exchange type which can adsorb chloride ions is particularly preferable.

In addition, the curable resin composition for sealing an organic EL display element of the present invention may contain various known additives such as a storage stabilizer, a plasticizer, and a viscoelasticity adjusting agent, as needed, without impairing the object of the present invention.

As a method of producing the curable resin composition for sealing an organic EL display element of the present invention, for example, a mixer such as a homogeneous phase disperser, a homomixer, a universal mixer, a planetary mixer, a kneader, or a three-roll mill can be used. A method of mixing a polyfunctional cationically polymerizable oligomer, a cationically polymerizable polymer, a curing agent, and an additive to be added as needed.

The preferred lower limit of the melt viscosity of the curable resin composition for sealing an organic EL display element of the present invention at 100 ° C is 1000 Pa. s, the upper limit is preferably 50,000 Pa. s. If the melt viscosity at 100 ° C is less than 1000Pa. s, when the roll is bonded, the fluidity becomes large, and the curable resin overflows from the end portion of the bonding to stain the roll or the organic EL display element, or the thickness at the time of coating becomes uneven. . If the melt viscosity at 100 ° C exceeds 50,000 Pa. s, there is a case where the follow-up of the laminated body having the organic light-emitting material layer is followed by the roll bonding The property is lowered, and it becomes easy to cause entrainment of bubbles or to lower the adhesion force. In addition, in order to assist the followability of the unevenness of the laminated body having the organic light-emitting material layer, it is necessary to perform an operation such as increasing the pressure of the roll bonding to damage the obtained organic EL display element. The lower limit of the above melt viscosity at 100 ° C is 1500 Pa. s, the upper limit is better than 21100Pa. s.

Further, the above-mentioned melt viscosity at 100 ° C was determined by using a rheometer at a frequency of 1 Hz and a temperature increase rate of 5 ° C/min, and the viscosity at 100 ° C when the viscosity was measured while heating.

The curable resin composition for sealing an organic EL display element of the present invention preferably has a gas release amount of μg/cm ² unit of 200 ppm or less when the cured product having a thickness of 20 μm is allowed to stand at 120 ° C for 15 minutes. When the amount of outgas is more than 200 ppm, the obtained organic EL display element is adversely affected by outgassing. The upper limit of the above gas release amount is preferably 100 ppm.

Furthermore, the outgas volume of the above μg/cm ² unit can be obtained by using a double-click pyrolyzer and a glass space chromatography/mass spectrometer (GC-MS) dynamic space method. Toluene was measured as a standard substance and quantified. Further, the cured product having the above-described outgassing amount can be obtained by drying the curable resin composition for sealing an organic EL display element in an oven at 80 ° C for 15 minutes.

The curable resin composition for sealing an organic EL display device of the present invention preferably has a visible light transmittance of 95% or more at a wavelength of 400 to 800 nm when a cured product having a thickness of 20 μm is formed. When the visible light transmittance is less than 95%, the transparency is inferior and it cannot be applied to the top emission type organic EL display element. A lower limit of the above-mentioned better visible light transmittance is 97%. Furthermore, the above visible light transmittance can be measured using a spectrophotometer. Again, on the measurement The cured product of the visible light transmittance can be transferred to an alkali-free glass substrate by roll laminating the sheet obtained by drying the curable resin composition for sealing an organic EL display element in an oven at 80 ° C for 15 minutes. Thereafter, it was obtained by heating in an oven at 100 ° C for 1 hour for hardening.

The curable resin sheet for sealing an organic EL display element obtained by molding the curable resin composition for sealing an organic EL display element of the present invention into a sheet form is also one of the present inventions.

The method of forming the curable resin composition for sealing an organic EL display element of the present invention into a sheet shape is preferably a solution coating method in which a sheet having a uniform film thickness can be formed at a relatively low temperature. Specifically, for example, a method in which a solution containing a curable resin composition for sealing an organic EL display element of the present invention and a solvent is applied to a PET subjected to release treatment at a specific thickness is used. A film such as polyethylene terephthalate or the like (hereinafter also referred to as "release film") is dried to obtain a film.

As a method of applying a solution containing the curable resin composition for sealing an organic EL display element of the present invention and a solvent to a release film, for example, roll coating, slit coating, and corner wheel coating can be used. A known method such as gravure coating, contact coating, die coating, lip coating, blade coating, and bar coating.

The solvent is, for example, a known solvent such as methyl ethyl ketone, methyl isobutyl ketone, toluene or ethyl acetate. Among them, methyl ethyl ketone and toluene are preferred.

The organic EL display element produced by using the curable resin composition for sealing an organic EL display element of the present invention and/or the curable resin sheet for sealing an organic EL display element of the present invention is also one of the present inventions.

As a method of producing the organic EL display element of the present invention, for example, the following method can be mentioned The curable resin sheet for sealing an organic EL display element of the present invention which is formed on a release film is thermally laminated on a substrate on which a laminate having an organic light-emitting material layer is formed by roll bonding, and the release film is peeled off. After that, the ultra-thin glass or the gas-repellent plastic sheet is laminated on the laminate having the organic light-emitting material layer to seal the organic EL display element by interposing the curable resin sheet for sealing the organic EL display element of the present invention; or The curable resin sheet for sealing an organic EL display element of the present invention formed on a release film is thermally laminated on a glass or a gas-barrier plastic sheet by roll bonding, and after peeling off the release film, the present invention is further interposed. The organic EL display element sealing curable resin sheet is laminated on a substrate on which a laminate having an organic light-emitting material layer is formed to seal the organic EL display element.

The organic EL display element of the present invention is preferably produced in a temperature range of about 50 to 100 ° C from the viewpoint of preventing damage or deterioration of the organic EL display element. Therefore, the curable resin sheet for sealing an organic EL display element of the present invention must exhibit fluidity in the temperature region, and the melt viscosity of the curable resin composition for sealing an organic EL display element of the present invention is preferably in the above range.

The curable resin composition for sealing an organic EL display element of the present invention and the curable resin sheet for an organic EL display element of the present invention are compared with a conventional sealing material such as a sheet-like adhesive or a sheet-shaped thermoplastic resin which does not have reactivity. It is excellent in heat resistance or barrier properties.

In addition, since the curable resin sheet for sealing an organic EL display element of the present invention is excellent in transparency and is excellent in transparency, it can be applied to a top emission type organic EL display element having excellent light extraction efficiency, and excellent in bending resistance. Therefore, when it is used in a flexible display, an organic EL display element which is less likely to cause cracking of the sealing layer due to bending and which is less deteriorated by bending can be obtained.

Further, in the organic EL display device of the present invention, the curable resin composition for sealing an organic EL display device of the present invention and/or the curable resin sheet for an organic EL display device are used, and a laminate having an organic light-emitting material layer is formed. By sealing the gap between the glass or the film and the opposing glass or film, it is possible to suppress the penetration of moisture, suppress the occurrence of dark spots, or deteriorate the display due to the growth of the dark spots, and it is excellent in life or reliability.

According to the present invention, it is possible to provide a curable resin composition for sealing an organic electroluminescence display element, which can prevent generation of cracks due to heating or bending, and can obtain a resin excellent in adhesion, transparency, and barrier properties. sheet. Moreover, according to the present invention, the curable resin sheet for organic electroluminescence display element sealing and the organic electroluminescence display element which are obtained by using the curable resin composition for sealing an organic electroluminescence display element can be provided.

Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited to the examples.

(Example 1)

Methyl methacrylate-glycidyl methacrylate copolymer as a cationically polymerizable polymer ("MARPROOF G-2050M", manufactured by Nippon Oil Co., Ltd., weight average molecular weight: 220,000, cationically polymerizable group equivalent: 340 g/mol The solution was dissolved in methyl ethyl ketone to prepare a methyl ethyl ketone solution containing 35 wt% of a cationically polymerizable polymer. Polymeric oligomerization as a multifunctional cationic 100 parts by weight of a bisphenol A type epoxy oligomer (manufactured by DIC Corporation, "EPICLON 840-S", molecular weight 340, cationically polymerizable group equivalent: 175 g/mol), and an aromatic hydrazine as a thermal cationic polymerization initiator 6 parts by weight of salt ("San-Aid SI-60" manufactured by Sanshin Chemical Industry Co., Ltd.) and 3-glycidoxypropyltrimethoxydecane as a decane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM" -40") A methyl ethyl ketone solution containing 35% by weight of a cationically polymerizable polymer prepared by adding a cationically polymerizable polymer to 100 parts by weight of 2 parts by weight. Methyl ethyl ketone was further added in such a manner that the blending amount of the entire methyl ethyl ketone was 300 parts by weight, and the blending mixer ("THINKY MIXER ARE-310" manufactured by THINKY Co., Ltd.) was used. The mixture was stirred at a stirring speed of 2000 rpm for 2 minutes, and mixed to obtain a uniform curable resin composition solution for sealing an organic EL display element.

Then, the solution of the curable resin composition for sealing the obtained organic EL display element obtained was applied to the PET film subjected to the release treatment in a thickness of 80 ° C in an oven by using an applicator. After drying for 15 minutes, a curable resin sheet for organic EL display element sealing (thickness: 20 μm and 100 μm) laminated on a PET film was obtained.

(Examples 2 to 11 and Comparative Examples 1 to 5)

The materials to be used and the blending amount are as shown in Tables 1 to 3. A curable resin composition for an organic EL display device was produced in the same manner as in Example 1 except the above.

<evaluation>

The curable resin composition for each of the organic EL display elements obtained in the examples and the comparative examples and the curable resin sheet for sealing the organic EL display element were evaluated as follows. The results are shown in Tables 1 to 3.

(1) Melt viscosity

Each of the 16 layers of the curable resin sheet for sealing an organic EL display element (thickness: 20 μm) obtained in the examples and the comparative examples was laminated to prepare a test piece having a thickness of about 300 μm. The laminate is formed by laminating two sheets of the thermosetting resin sheet on the release film so that the surfaces of the thermosetting resin sheet overlap each other without generating bubbles, thereby producing a release film on both sides. After the two-layer laminated body of the thermosetting sheet is sandwiched and cut into a size of one-half, the release film of one side is peeled off, and the thermosetting resin sheet surfaces are again superposed on each other to perform roll type. Stack, repeat 4 times in this order.

A circular sample having a diameter of 8 mm was punched out from the test piece, and a rheometer (manufactured by Reologica Co., Ltd., DAR-100 viscoelasticity measuring device) was used to heat from 25 ° C at a frequency of 1 Hz and a temperature increase rate of 5 ° C / min. The viscosity was measured at 150 ° C, and the melt viscosity at 100 ° C was determined.

(2) Air release

Approximately 50 mg of each of the organic EL display element sealing curable resin sheets (thickness 20 μm) obtained in the examples and the comparative examples was placed in a test container by using a double-click pyrolyzer and a glass chromatography/mass spectrometer (GC- The dynamic space method of MS) measures the amount of outgas generated when heated at 120 ° C for 15 minutes. The amount of gas released is quantified using toluene as a standard substance.

(3) Adhesiveness

Each of the organic EL display element sealing curable resin sheets (thickness: 20 μm) obtained in the examples and the comparative examples was laminated on a glass substrate having a thickness of 1 mm using a roll bonding machine. Then, a glass wafer having a length of 3 mm, a width of 3 mm, and a thickness of 0.7 mm was placed on a curable resin sheet for sealing an organic EL display element laminated on a glass substrate, and a simple thermocompression bonding machine (manufactured by OSAKI ENGINEERING, "CT-300" was used. "), at a pressure of 0.2 MPa and a temperature of 90 ° C After pressing for 10 seconds, it was hardened by heating at 100 ° C for 1 hour in an oven to obtain a test piece. The obtained test piece was measured for wafer shear adhesion using a universal bond strength tester (manufactured by Nordson Advanced Technology, "Series 4000"). The case where the wafer shearing force is 150 N or more is set to "○", the case where the bonding force is less than 150 N and 100 N or more is set to "△", and the case where the bonding force is less than 100 N is set to "X", and then Sexual evaluation.

(4) Barrier

Each of the organic EL display element sealing curable resin sheets (thickness: 100 μm) obtained in the examples and the comparative examples was heated in an oven at 100 ° C for 1 hour to be cured to obtain a test piece. The obtained test piece was subjected to moisture permeability measurement according to JIS Z 0208.

Specifically, the test piece is set at 60 mm. The shroud was measured for weight change every three hours at a test temperature of 60 ° C and a test humidity of 90% RH using a constant temperature and humidity chamber ("PL-2KP" manufactured by Tabay ESPEC). Amount and find the average.

The case where the moisture permeability is less than 50 g/m ² is "○", the case of 50 g/m ² or more and less than 80 g/m ² is "△", and the case of 80 g/m ² or more is "X". The barrier property (water permeability resistance) of the cured product was evaluated.

In addition, the moisture permeability is usually measured by a moisture permeable cover as in JIS Z 0208, but it can also be measured using a water vapor transmission rate measuring device such as PERMATRAN W3/33 manufactured by AMERICA MOCON.

(5) Visible light transmittance and haze

Each of the organic EL display element sealing curable resin sheets (thickness: 20 μm) obtained in the examples and the comparative examples was roll-laminated and transferred to an alkali-free glass substrate having a width of 25 mm, a length of 50 mm, and a thickness of 0.7 mm, and then placed in an oven. Heated at 100 ° C for 1 hour to harden it and obtain a test. sheet. In the test piece, the visible light transmittance at a wavelength of 400 to 800 nm was measured by a spectrophotometer with reference to the glass substrate before the transfer of the curable resin sheet for organic EL display element sealing. Further, the test piece in which the visible light transmittance was measured was measured for haze (haze value) using a haze meter.

(6) Light-emitting state of the organic EL display element

An alkali-free glass substrate formed by depositing a 1000 Å thick ITO transparent electrode by sputtering is used as a transparent supporting substrate, and N,N'-bis(1-naphthyl)-N,N is vacuum-deposited. '-Diphenylbenzidine (α-NPD) was deposited on the substrate at a deposition rate of 15 Å/s to form a film transport layer having a thickness of 600 Å. Then, tris(8-hydroxyquinoline)aluminum (Alq ₃ ) was deposited at a deposition rate of 15 Å/s to a film thickness of 600 Å to form a light-emitting layer. Thereafter, the substrate was transferred to another vacuum evaporation apparatus, and lithium fluoride was formed into a film of 5 Å at a vapor deposition rate of 0.2 Å/s, and then aluminum was formed into a film of 1000 Å at a rate of 20 Å/s to obtain organic light emission. A layer of material layers.

Each of the organic EL display element sealing curable resin sheets obtained in the examples and the comparative examples was roll-laminated at 80 ° C and transferred onto a substrate on which the layered body was formed. Furthermore, the glass substrate was superimposed on the curable resin sheet for sealing the organic EL display element after the transfer, and the pressure bonding was performed at 80 ° C using a vacuum laminator. Thereafter, the organic EL display element sealing curable resin sheet was cured by heating in an oven at 100 ° C for 1 hour to obtain an organic EL display element.

The obtained organic EL display device was exposed to a temperature of 60 ° C and a humidity of 90% for 100 hours, and then a voltage of 10 V was applied to visually observe the light-emitting state of the device (the presence or absence of light emission and dark spots). The case where the dark spot is not emitted and the light is uniformly emitted is "○", and the case where the light is emitted but the dark spot is present is "Δ", and the case where the light is not emitted at all is "x".

(7) Flexibility of organic EL display elements

A gas barrier film formed by depositing ZnSnO _x having a thickness of 1000 Å on a PET film having a thickness of 100 μm is used as a transparent supporting substrate, and a ITO transparent electrode having a thickness of 1000 Å is formed by sputtering, according to the above (6) The light-emitting state of the organic EL element is the same order, and the hole transport layer of N,N'-bis(1-naphthyl)-N,N'-diphenylbenzidine (α-NPD) is sequentially formed. A light-emitting layer of tris(8-hydroxyquinoline)aluminum (Alq ₃ ), an electron transport layer of lithium fluoride, and an aluminum electrode are formed into a film to obtain a laminate having an organic light-emitting material layer.

On the other hand, each of the curable resin sheets for sealing an organic EL display element obtained in the examples and the comparative examples was subjected to roll lamination at 80 ° C and transferred to a film thickness of 1000 Å by sputtering on a PET film having a thickness of 100 μm. A gas barrier film made of ZnSnO _x and a cured resin sheet for sealing an organic EL display element are laminated on a film substrate on which a laminate having an organic light-emitting material layer is formed by roll lamination at 80 ° C. Thereafter, the organic EL display element sealing curable resin sheet was cured by heating at 100 ° C for 1 hour in each oven to obtain an organic EL display element.

The obtained organic EL display element was bent by a bending test according to JIS C5016, and bent 20 times with a radius of 5 mm, a back-and-forward moving distance of 20 mm, and a back-and-forth moving speed of 10 mm/sec, and exposed to 100 ° C and a humidity of 90%. In an hour, a voltage of 10 V was applied to visually observe the light-emitting state of the element. When the curved portion of the organic EL element is not leaked by the crack of the curable resin sheet for sealing the organic EL display element sealed by the gap of the gas barrier film, the case where the light-emitting region is reduced is set to "○". The case where the light-emitting area was reduced was set to "Δ", and the case where the light-emitting area was substantially disappeared or greatly reduced was set to "x", and the bending resistance was evaluated.

According to the present invention, it is possible to provide a curable resin composition for sealing an organic electroluminescence display element, which can prevent generation of cracks due to heating or bending, and can obtain a resin excellent in adhesion, transparency, and barrier properties. sheet. Moreover, according to the present invention, a curable resin sheet for organic electroluminescence display element sealing and an organic electroluminescence display element which are obtained by using the curable resin composition for sealing an organic electroluminescence display element can be provided.

Claims (9)

A curable resin composition for sealing an organic electroluminescence display element, comprising a polyfunctional cationically polymerizable oligomer, a cationically polymerizable polymer having a molecular weight of more than 100,000, and a curing agent. The curable resin composition for sealing an organic electroluminescence display element according to the first aspect of the invention, wherein the curing agent is a thermal cationic polymerization initiator. The curable resin composition for sealing an organic electroluminescence display device according to the first or second aspect of the invention, wherein the cationically polymerizable polymer has a cationic polymerizable group equivalent of 3000 g/mol or less. The curable resin composition for sealing an organic electroluminescence display element according to the first, second or third aspect of the invention, which comprises a decane coupling agent having a cationically polymerizable group. The curable resin composition for sealing an organic electroluminescence display element according to claim 1, 2, 3 or 4, wherein the melt viscosity at 100 ° C is 1000 to 50,000 Pa. s. The curable resin composition for sealing an organic electroluminescence display element according to the first, second, third, fourth or fifth aspect of the invention, wherein the polyfunctional cationically polymerizable oligomer has an oligomer of an alicyclic skeleton. The curable resin composition for sealing an organic electroluminescence display element according to the first, second, third, fourth, fifth or sixth aspect of the invention, wherein the polyfunctional cationically polymerizable oligomer has an epoxy group or an oxa group. An oxetanyl group does not have a compound other than an ether bond contained in an epoxy group or an oxetanyl group, and an ether bond other than an ester bond, and an ester bond. A curable resin sheet for sealing an organic electroluminescence display element, which is a curing property for sealing an organic electroluminescence display element of the first, second, third, fourth, fifth, sixth or seventh aspect of the patent application The resin composition is formed into a sheet shape. An organic electroluminescence display element using a curable resin composition for sealing an organic electroluminescence display element according to claim 1, 2, 3, 4, 5, 6 or 7 and/or a patent application scope The eighth-order organic electroluminescence display element is produced by sealing a curable resin sheet.