TW202109786A - Sealant for organic EL display element - Google Patents

Abstract

An objective of the present invention is to provide a sealant for, an organic EL display element, that excels in low outgassing and coating properties and makes it possible to achieve an organic EL display element excelling in light extraction efficiency. The present invention is a sealant, for an organic EL display element, containing a cationic polymerizable compound and a cationic polymerization initiator, wherein the cationic polymerizable compound includes a cycloalkene oxide-type alicyclic epoxy compound and a compound having a biphenyl skeleton and an epoxy group or an oxetanyl group.

Description

Sealant for organic EL display element

The present invention relates to a sealing agent for an organic EL display element which is excellent in low outgassing properties and coating properties, and can obtain an organic EL display element with excellent light extraction efficiency.

Organic electroluminescence (hereinafter also referred to as "organic EL") display elements have a laminated structure in which an organic light-emitting material layer is sandwiched between a pair of electrodes facing each other. For the organic light-emitting material layer, one electrode Inject electrons and inject holes from the other electrode, whereby the electrons and holes are combined in the organic light-emitting material layer to emit light. In this way, the organic EL display element emits self-luminescence, and therefore has the following advantages compared with liquid crystal display elements that require a backlight, such as better visibility, thinner thickness, and low-voltage direct current driving.

The organic light-emitting material layer or electrode constituting the organic EL display element has a problem that its characteristics are easily degraded by moisture, oxygen, or the like. Therefore, in order to obtain a practical organic EL display element, it is necessary to isolate the organic light-emitting material layer or electrode from the atmosphere to achieve a long life. As a method of shielding the organic light-emitting material layer or electrode from the atmosphere, a sealant is used to seal the organic EL display element (for example, Patent Document 1). When using a sealant to seal an organic EL display element, the following method is usually used: In order to sufficiently suppress the permeation of moisture or oxygen, an inorganic material called a passivation film is provided on a laminate with an organic light-emitting material layer The film is sealed with a sealant on the inorganic material film.

In recent years, instead of bottom-emission type organic EL display elements that extract light emitted from an organic light-emitting material layer from the side of the substrate on which light-emitting elements are formed, top-emission type organic EL display elements that extract light from the upper surface of the organic light-emitting layer have attracted attention. . This method has a higher aperture ratio and low-voltage drive, so it has the advantage of prolonging life. In this type of top-emission organic EL display element, since the upper surface of the light-emitting layer needs to be transparent, the upper surface of the light-emitting element is sealed with a transparent moisture-proof substrate such as transparent sealing laminated glass (for example, Patent Document 2). However, the top-emission organic EL display element has the following problem: even when a material with sufficiently high transparency is used as a transparent moisture-proof substrate or sealant, the extraction efficiency of light emitted from the laminate may be caused by electrodes or passivation. A situation where the refractive index of the film and the sealant is poor. In addition, the conventional sealant has the problem of generating outgassing, deteriorating the device, or having poor coating properties. Furthermore, in order to reduce the damage to the organic EL display element caused by heating, a sealant that can be cured at a low temperature is sought. Prior art literature Patent literature

Patent Document 1: Japanese Patent Application Publication No. 2007-115692 Patent Document 2: Japanese Patent Application Publication No. 2009-051980

[The problem to be solved by the invention]

The object of the present invention is to provide a sealing agent for an organic EL display element which is excellent in low outgassing properties and coating properties, and can obtain an organic EL display element excellent in light extraction efficiency. [Technical means to solve the problem]

The present invention is a sealant for an organic EL display element, which contains a cationic polymerizable compound and a cationic polymerization initiator, and the cationic polymerizable compound includes a cycloalkane oxide type alicyclic epoxy compound, and Compounds with biphenyl skeleton and epoxy or oxetanyl. The present invention will be described in detail below.

The present inventors studied the use of an oxidized cycloolefin type alicyclic epoxy compound as a cationic polymerizable compound in a sealant for an organic EL display element, thereby improving coating properties and preventing outgassing. However, although this kind of sealant using cycloalkene oxide type alicyclic epoxy compound is excellent in preventing outgassing, it has a large difference in refractive index with the electrode or passivation film, so the light extraction efficiency is caused by the electrode or passivation. The problem of reduced reflection at the interface between the film and the sealant. Therefore, the present inventors studied the use of this oxidized cycloolefin-type alicyclic epoxy compound in combination with a compound having a biphenyl skeleton and an epoxy group or an oxetanyl group as a cationic polymerizable compound. As a result, it was found that a sealing agent for an organic EL display element which is excellent in low outgassing properties and coatability, and can make the obtained organic EL display element excellent in light extraction efficiency, and completed the present invention. In addition, when a thermal cationic polymerization initiator is used as a cationic polymerization initiator and the sealant for organic EL display elements of the present invention is a thermal curing sealant, it can be easily made at a low temperature of 100°C or less hardening.

The sealing agent for organic EL display elements of the present invention contains a cationic polymerizable compound. The cationically polymerizable compound includes an oxidized cycloolefin type alicyclic epoxy compound. By containing the above-mentioned oxidized cycloolefin type alicyclic epoxy compound, the sealing agent for an organic EL display element of the present invention is excellent in low outgassing properties and coating properties.

As the above-mentioned oxidized cycloolefin type alicyclic epoxy compound, for example, 3,4-epoxycyclohexyl carboxylic acid 3',4'-epoxycyclohexyl methyl ester, bis(3,4-epoxycyclohexyl) Methyl) ether, bis(3,4-epoxycyclohexane-1-ylmethyl) adipate, 1,2-epoxy of 2,2-bis(hydroxymethyl)-1-butanol -4-(2-oxiranyl)cyclohexane adduct, [(3,4-epoxycyclohexane)-1-yl]methyl methacrylate, etc.

Examples of commercially available oxidized cycloolefin-type alicyclic epoxy compounds include Celloxide 2021P (manufactured by Daicel), TTA26 (manufactured by Sun Chemical), EHPE3150 (manufactured by Daicel), and the like.

The lower limit of the content of the oxidized cycloolefin-type alicyclic epoxy compound in 100 parts by weight of the entire cationically polymerizable compound is preferably 3 parts by weight, and the upper limit is preferably 45 parts by weight. When the content of the oxidized cycloalkene-type alicyclic epoxy compound is 3 parts by weight or more, the resulting sealant for organic EL display elements is more excellent in curability, low outgassing properties, and coating properties. When the content of the oxidized cycloolefin type alicyclic epoxy compound is 45 parts by weight or less, the light extraction efficiency of the obtained organic EL display device is more excellent. The lower limit of the content of the oxidized cycloolefin-type alicyclic epoxy compound is more preferably 5 parts by weight, the upper limit is more preferably 40 parts by weight, and the upper limit is still more preferably 38 parts by weight.

The above-mentioned cationically polymerizable compound includes a compound having a biphenyl skeleton and an epoxy group or an oxetanyl group. By containing the above-mentioned compound having a biphenyl skeleton and epoxy group or oxetanyl group, the difference in refractive index between the sealing agent for an organic EL display element of the present invention and the electrode or passivation film becomes small, and as a result the obtained organic EL display element The light extraction efficiency is excellent. In addition, by including a compound having a biphenyl skeleton and an epoxy group or an oxetanyl group, when the sealant for an organic EL display element of the present invention is a thermosetting sealant, it can be easily heated at 100°C. Harden it at the following low temperature.

As the above-mentioned compound having a biphenyl skeleton and an epoxy group or oxetanyl group, as long as it is an epoxy compound having a biphenyl skeleton or an oxetane compound having a biphenyl skeleton, the viscosity, refractive index, From the viewpoint of photocurability and the like, various compounds having a biphenyl skeleton and epoxy groups or oxetanyl groups can be appropriately selected.

Specific examples of the compound having a biphenyl skeleton and an epoxy group or oxetanyl group include o-phenylphenol glycidyl ether, a compound represented by the following formula (1), and p-benzene Phenol glycidyl ether, 4,4-biphenyldiyl bis(glycidyl ether), 4,4'-bis(glycidoxy)-1,1'-biphenyl, 3,3 ',5,5'-Tetramethyl-4,4'-bis(glycidoxy)-1,1'-biphenyl etc. Among them, o-phenylphenol glycidyl ether and the compound represented by the following formula (1) are preferred. The compound having a biphenyl skeleton and an epoxy group or an oxetanyl group may be used alone or in combination of two or more kinds.

In formula (1), n is the repeat number. This n is preferably a value in which the compound represented by the formula (1) satisfies the range of the following oxetanyl equivalent.

The preferred lower limit of the epoxy equivalent or oxetanyl equivalent of the compound having a biphenyl skeleton and epoxy or oxetanyl group is 110, and the preferred upper limit is 500. When the epoxy equivalent or oxetanyl equivalent of the compound having a biphenyl skeleton and epoxy group or oxetanyl group is in this range, the adhesiveness and low outgassing of the resulting sealant for organic EL display devices It has more excellent properties and coating properties. Furthermore, in this specification, the epoxy equivalent or oxetanyl equivalent of the compound having a biphenyl skeleton and an epoxy or oxetanyl group means (having a biphenyl skeleton and an epoxy or oxetanyl group) Molecular weight of cyclobutyl compound)/(number of epoxy or oxetanyl groups in 1 molecule of compound with biphenyl skeleton and epoxy or oxetanyl groups).

The preferred lower limit of the molecular weight of the compound having a biphenyl skeleton and epoxy group or oxetanyl group is 200, and the preferred upper limit is 1,000. When the molecular weight of the compound having a biphenyl skeleton and an epoxy group or an oxetanyl group is in this range, the resulting sealant for an organic EL display device has more excellent adhesiveness, low outgassing properties, and coating properties. Furthermore, in this specification, the above-mentioned "molecular weight" refers to the molecular weight obtained from the structural formula for compounds with a specific molecular structure, while for compounds with a wide distribution of degree of polymerization and compounds with unspecified modified sites, there are some use It is expressed by weight average molecular weight. In addition, the above-mentioned "weight average molecular weight" is a value determined by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and calculated in terms of polystyrene. As a column used when measuring the weight average molecular weight obtained by polystyrene conversion by GPC, for example, Shodex LF-804 (manufactured by Showa Denko Corporation) and the like can be cited.

The compound having a biphenyl skeleton and an epoxy group or oxetanyl group is preferably liquid at 25°C. Coatability of the resulting sealant for organic EL display devices by the epoxy equivalent or oxetanyl equivalent of the compound having a biphenyl skeleton and epoxy or oxetanyl group being liquid at 25°C More excellent.

Examples of commercially available compounds having a biphenyl skeleton and an epoxy group or oxetanyl group include OPP-EP (manufactured by Yokkaichi Gosei Co., Ltd.), ETERNACOLL OXBP (manufactured by Ube Industries Co., Ltd.), and the like.

A preferable lower limit of the content of the compound having a biphenyl skeleton and an epoxy group or an oxetanyl group in 100 parts by weight of the entire cationically polymerizable compound is 30 parts by weight, and a preferable upper limit is 97 parts by weight. When the content of the compound having a biphenyl skeleton and an epoxy group or an oxetanyl group is 30 parts by weight or more, the light extraction efficiency of the obtained organic EL display device is more excellent. When the content of the compound having a biphenyl skeleton and an epoxy group or an oxetanyl group is 97 parts by weight or less, the resulting sealant for organic EL display devices has better curability, low outgassing properties, and coating properties. Excellent. The lower limit of the content of the compound having a biphenyl skeleton and an epoxy group or an oxetanyl group is more preferably 50 parts by weight, a more preferable upper limit is 90 parts by weight, and a more preferable upper limit is 80 parts by weight. When the content of the oxidized cycloalkene-type alicyclic epoxy compound is set to 1, the ratio of the content of the compound having a biphenyl skeleton to the epoxy group or oxetanyl group is based on a weight ratio, preferably The lower limit is 1, and the preferred upper limit is 20. By setting the ratio of the content of the compound having a biphenyl skeleton to the epoxy group or oxetanyl group to 1 or more, the obtained sealing agent for organic EL display device has a more excellent refractive index (light extraction efficiency), and By setting it to 20 or less, the curability and refractive index are more excellent. The lower limit of the ratio of the content of the compound having a biphenyl skeleton to the epoxy group or oxetanyl group is more preferably 1.3, the upper limit is more preferably 15, the lower limit is still more preferably 1.4, and the upper limit is still more preferably 10.

The cationically polymerizable compound may include other cationically polymerizable compounds in addition to the oxidized cycloolefin-type alicyclic epoxy compound and the compound having a biphenyl skeleton and an epoxy group or an oxetanyl group. Examples of the above-mentioned other cationic polymerizable compounds include: the above-mentioned oxidized cycloalkene-type alicyclic epoxy compounds and the above-mentioned compounds having a biphenyl skeleton and epoxy groups or oxetanyl groups, other epoxy compounds, and other oxygen Etidine compounds, vinyl ether compounds, etc.

Examples of the above-mentioned other epoxy compounds include: sulphur-type epoxy compounds, 1,7-octadiene diepoxide, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, Diethylene Glycol Diglycidyl Ether, Polyethylene Glycol Diglycidyl Ether, Propylene Glycol Diglycidyl Ether, Dipropylene Glycol Diglycidyl Ether, Tripropylene Glycol Diglycidyl Ether, Polypropylene Glycol Diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, phenylglycidyl ether, extension Phenyl diglycidyl ether and so on.

Examples of the above-mentioned other oxetane compounds include 3-ethyl-3-(((3-ethyloxetan-3-yl)methoxy)methyl)oxetane , 3-ethyl-3-((2-ethylhexyloxy)methyl)oxetane, 3-ethyl-3-((3-(triethoxysilyl)propoxy) Methyl)oxetane, phenol novolac oxetane, 1,4-bis(((3-ethyl-3-oxetanyl)methoxy)methyl)benzene, etc.

Examples of the vinyl ether compound include benzyl vinyl ether, cyclohexanedimethanol monovinyl ether, dicyclopentadiene vinyl ether, 1,4-butanediol divinyl ether, and cyclohexanedimethanol diethylene. Ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, dipropylene glycol divinyl ether, tripropylene glycol divinyl ether, etc.

Among them, the other cationically polymerizable compound is preferably selected from 3-ethyl-3-(((3-ethyloxetan-3-yl)methoxy)methyl)oxetane At least one of the group consisting of alkane, 1, 2:7,8-diepoxyoctane and 1, 2:5,6-diepoxycyclooctane, more preferably 3-ethyl-3- (((3-Ethyloxetan-3-yl)methoxy)methyl)oxetane.

When the above-mentioned cationically polymerizable compound contains the above-mentioned other cationically polymerizable compound, the preferred lower limit of the content of the above-mentioned other cationically polymerizable compound in 100 parts by weight of the above-mentioned cationically polymerizable compound is 1 part by weight, and the preferred upper limit is 60 parts by weight. Copies. When the content of the other cationically polymerizable compound is in this range, the adhesiveness and coatability of the resulting sealant for an organic EL display element are more excellent. The lower limit of the content of the other cationically polymerizable compound is more preferably 10 parts by weight, the upper limit is more preferably 50 parts by weight, the lower limit is still more preferably 15 parts by weight, and the upper limit is still more preferably 40 parts by weight. In addition, when the cationically polymerizable compound contains the other cationically polymerizable compound, the total content of the oxidized cycloolefin-type alicyclic epoxy compound and the other cationically polymerizable compound in 100 parts by weight of the cationically polymerizable compound The preferred lower limit is 20 parts by weight. When the total content of the oxidized cycloolefin-type alicyclic epoxy compound and the other cationically polymerizable compound is 20 parts by weight or more, the resulting sealant for an organic EL display element has more excellent coatability. The lower limit of the total content of the oxidized cycloolefin-type alicyclic epoxy compound and the other cationically polymerizable compound is more preferably 25 parts by weight.

The sealing agent for organic EL display elements of the present invention contains a cationic polymerization initiator. Examples of the cationic polymerization initiator include thermal cationic polymerization initiators and photocationic polymerization initiators. Especially when the sealing agent for organic EL display elements of the present invention uses a thermal cationic polymerization initiator as the cationic polymerization initiator, it can be easily cured at a low temperature of 100°C or less.

As the thermal cationic polymerization initiator include: anionic moiety of _{^{BF 4 -, PF 6 -,}} SbF 6 - or (BX ₄₎ ^- (wherein, X is substituted with at least two or more of fluoro or trifluoromethyl The phenyl) constituted by sulfonium salt, phosphonium salt, ammonium salt, diazonium salt, iodonium salt, etc. Among them, sulfonium salt is preferred.

Examples of the above-mentioned sulfonium salt include triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroantimonate, and the like.

As said phosphonium salt, ethyl triphenyl phosphonium hexafluoroantimonate, tetrabutyl phosphonium hexafluoroantimonate, etc. are mentioned.

As the above-mentioned ammonium salt, for example, dimethylphenyl(4-methoxybenzyl)ammonium hexafluorophosphate, 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 hexafluorotetra(pentafluorophenyl)borate, methylphenyldibenzylammonium hexafluoro Phosphate, methyl phenyl dibenzyl ammonium hexafluoroantimonate, methyl phenyl dibenzyl ammonium tetra (pentafluorophenyl) borate, phenyl tribenzyl ammonium tetra (pentafluorophenyl) borate , Dimethylphenyl(3,4-dimethylbenzyl)ammonium tetra(pentafluorophenyl)borate, N,N-dimethyl-N-benzylanilinium hexafluoroantimonate, N, N-diethyl-N-benzylanilinium tetrafluoroborate, N,N-dimethyl-N-benzylpyridinium hexafluoroantimonate, N,N-diethyl-N-benzylpyridine Onium trifluoromethanesulfonic acid and so on.

As a commercially available one among the above-mentioned thermal cationic polymerization initiators, for example, a thermal cationic polymerization initiator manufactured by Sanshin Chemical Industry Co., Ltd., a thermal cationic polymerization initiator manufactured by King Industries, etc. can be cited. As the thermal cationic polymerization initiator manufactured by Sanxin Chemical Industry Co., Ltd., for example, San-Aid SI-60, San-Aid SI-80, San-Aid SI-B3, San-Aid SI-B3A, San-Aid Aid SI-B4 and so on. As the thermal cationic polymerization initiator manufactured by the above-mentioned King Industries, for example, CXC-1612, CXC-1821, and the like can be cited.

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

Examples of the ionic photoacid generator type photo cationic polymerization initiator of the anionic moiety include, for _{^{example: BF 4 -, PF 6 -}} , SbF 6 -, (BX 4) - ( wherein, X represents at least two of the above via Fluorine or trifluoromethyl substituted phenyl) etc. And, as the anionic moiety, it may include _{PF m (C n F 2n +} 1) 6 - m - ( wherein, in the formula, m an integer of 5 or less and above 0 line, line n-1 and an integer of 6 or more of the following) Wait. Examples of the above-mentioned ionic photoacid-generating photocationic polymerization initiator include aromatic sulfonium salts, aromatic iodonium salts, aromatic diazonium salts, aromatic ammonium salts, (2,4 -Cyclopentadien-1-yl)((1-methylethyl)benzene)-iron salt and the like.

As the above-mentioned aromatic sulfonium salt, for example, bis(4-(diphenyldihydrosulfanyl)phenyl)sulfanyl bishexafluorophosphate, bis(4-(diphenyldihydrosulfanyl)phenyl) )Sulfuryl bishexafluoroantimonate, bis(4-(diphenyldihydrosulfanyl)phenyl)sulfanyl bistetrafluoroborate, bis(4-(diphenyldihydrosulfanyl)phenyl) Sulfuryl tetrakis (pentafluorophenyl) borate, diphenyl-4-(phenylthio) phenyl sulfonium hexafluorophosphate, diphenyl-4-(phenylsulfonyl) phenyl sulfonium hexafluoroantimonate , Diphenyl-4-(phenylthio)phenyl sulfonium tetrafluoroborate, diphenyl-4-(phenylthio) phenyl sulfonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium hexafluoro Phosphate, triphenyl alumium hexafluoroantimonate, triphenyl alumium tetrafluoroborate, triphenyl alumium tetrakis (pentafluorophenyl) borate, bis(4-(bis(4-(2-hydroxyethyl) (Oxy)) phenyl dihydrosulfanyl) phenyl) sulfanyl bishexafluorophosphate, bis(4-(bis(4-(2-hydroxyethoxy))phenyldihydrosulfanyl)phenyl) Sulfuryl bishexafluoroantimonate, bis(4-(bis(4-(2-hydroxyethoxy))phenyldihydrothio)phenyl)thio bistetrafluoroborate, bis(4-( Bis(4-(2-hydroxyethoxy))phenyldihydrothiophenyl)phenyl)thiotetrakis(pentafluorophenyl)borate, tris(4-(4-acetylphenyl)thienyl ) Tetrakis (pentafluorophenyl) borate and the like. Among them, triaryl alumium tetrakis (pentafluorophenyl) borate such as triphenyl alumium tetrakis (pentafluorophenyl) borate is preferable.

As the above-mentioned aromatic iodonium salt, for example, diphenyl iodonium hexafluorophosphate, diphenyl iodonium hexafluoroantimonate, diphenyl iodonium tetrafluoroborate, diphenyl iodonium tetrakis (pentafluorophenyl) Borate, bis(dodecylphenyl) hexafluorophosphate, bis(dodecylphenyl) hexafluoroantimonate, bis(dodecylphenyl) tetrafluoroborate, double (Dodecylphenyl) tetrakis (pentafluorophenyl) borate, 4-methylphenyl-4-(1-methylethyl)phenyl hexafluorophosphate, 4-methylphenyl -4-(1-Methylethyl)phenylphosphonium hexafluoroantimonate, 4-methylphenyl-4-(1-methylethyl)phenylphosphonium tetrafluoroborate, 4-methylbenzene 4-(1-methylethyl)phenylphosphonium tetrakis(pentafluorophenyl)borate and the like.

Examples of the above-mentioned aromatic diazonium salts include: phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrafluoroborate. (Pentafluorophenyl) borate and the like.

As the above-mentioned aromatic ammonium salt, for example, 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2 -Cyanopyridinium tetrafluoroborate, 1-benzyl-2-cyanopyridinium tetra(pentafluorophenyl) borate, 1-(naphthylmethyl)-2-cyanopyridinium hexafluorophosphate , 1-(naphthylmethyl)-2-cyanopyridinium hexafluoroantimonate, 1-(naphthylmethyl)-2-cyanopyridinium tetrafluoroborate, 1-(naphthylmethyl) -2-cyanopyridinium tetrakis (pentafluorophenyl) borate and the like.

As the above-mentioned (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-iron salt, for example, (2,4-cyclopentadien-1-yl)( (1-methylethyl)benzene)-iron(II)hexafluorophosphate, (2,4-cyclopentadien-1-yl)((1-methylethyl)benzene)-iron(II) Hexafluoroantimonate, (2,4-cyclopentadien-1-yl) ((1-methylethyl)benzene)-iron(II) tetrafluoroborate, (2,4-cyclopentadiene) -1-yl)((1-methylethyl)benzene)-iron(II)tetrakis(pentafluorophenyl)borate and the like.

Examples of the nonionic photo-acid-generating photocationic polymerization initiator include: nitrobenzyl ester, sulfonic acid derivative, phosphoric acid ester, phenol sulfonate, diazonaphthoquinone, and N-hydroxyimide sulfonate Acid esters and so on.

Examples of commercially available photocationic polymerization initiators include: photocationic polymerization initiator manufactured by Midori Kagaku, photocationic polymerization initiator manufactured by Union Carbide, and photocationic polymerization initiator manufactured by ADEKA. Starter, photocationic polymerization initiator manufactured by 3M, photocationic polymerization initiator manufactured by BASF, photocationic polymerization initiator manufactured by Solvay, photocationic polymerization initiator manufactured by San-Apro, etc. As the photocationic polymerization initiator manufactured by Midori Kagaku, for example, DTS-200 can be cited. As the photocationic polymerization initiator manufactured by Union Carbide, for example, UVI6990, UVI6974, etc. can be cited. Examples of the photocationic polymerization initiator manufactured by ADEKA include SP-150 and SP-170. Examples of the photocationic polymerization initiator manufactured by 3M include FC-508 and FC-512. Examples of the photocationic polymerization initiator manufactured by BASF include IRGACURE 261 and IRGACURE 290. As the photocationic polymerization initiator manufactured by Solvay, for example, PI2074 and the like can be cited. Examples of the photocationic polymerization initiator manufactured by San-Apro include CPI-100P, CPI-200K, and CPI-210S.

Among the above-mentioned cationic polymerization initiators, a quaternary ammonium salt whose relative anion is a borate type (hereinafter, also referred to as "borate-based quaternary ammonium salt") can be preferably used. The relative anion of the above-mentioned borate-based quaternary ammonium salt is preferably BF ₄ ^- or (BX ₄ )- (where X represents a phenyl group substituted with at least two fluorine or trifluoromethyl groups).

The content of the cationic polymerization initiator is preferably 0.05 parts by weight in the lower limit and 10 parts by weight in the upper limit with respect to 100 parts by weight of the cationically polymerizable compound. When the content of the cationic polymerization initiator is within this range, the resulting sealant for an organic EL display element has more excellent curability, storage stability, and moisture resistance of the cured product. The lower limit of the content of the cationic polymerization initiator is more preferably 0.1 parts by weight, and the upper limit is more preferably 5 parts by weight.

、N,N'-雙(2-甲基-1-咪唑基乙基)脲、N,N'-(2-甲基-1-咪唑基乙基)-己二醯胺、2-苯基-4-甲基-5-羥基甲基咪唑、2-苯基-4,5-二羥基甲基咪唑等。 作為上述酸酐，例如可列舉：四氫鄰苯二甲酸酐、乙二醇雙(脫水偏苯三酸酯)等。 該等熱硬化劑可單獨使用，亦可組合2種以上而使用。The sealing agent for organic EL display elements of the present invention may contain a thermosetting agent. Examples of the thermosetting agent include hydrazine compounds, imidazole derivatives, acid anhydrides, dicyandiamine, guanidine derivatives, modified aliphatic polyamines, and addition products of various amines and epoxy resins. As the above-mentioned hydrazine compound, for example, 1,3-bis(hydrazinocarbonylethyl)-5-isopropylhydantoin, sebacic hydrazine, isophthalic hydrazine, hexadihydrazine, Malondihydrazine and so on. Examples of the imidazole derivatives include 1-cyanoethyl-2-phenylimidazole, N-(2-(2-methyl-1-imidazolyl)ethyl)urea, and 2,4-diamine Base-6-(2'-Methylimidazolyl-(1'))-ethyl-symmetric three

, N,N'-bis(2-methyl-1-imidazolylethyl)urea, N,N'-(2-methyl-1-imidazolylethyl)-hexamethylenediamide, 2-phenyl -4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, etc. As said acid anhydride, tetrahydrophthalic anhydride, ethylene glycol bis (dehydrated trimellitate), etc. are mentioned, for example. These thermosetting agents may be used alone or in combination of two or more kinds.

As a commercially available one among the above-mentioned thermosetting agents, for example, a thermosetting agent manufactured by Otsuka Chemical Co., Ltd., a thermosetting agent manufactured by Ajinomoto Fine-Techno, etc. can be cited. Examples of the thermosetting agent manufactured by the above-mentioned Otsuka Chemical Co., Ltd. include SDH, ADH, and the like. Examples of the thermosetting agent manufactured by Ajinomoto Fine-Techno include Amicure VDH, Amicure VDH-J, and Amicure UDH.

The content of the thermosetting agent is preferably 0.5 parts by weight in the lower limit and 30 parts by weight in the upper limit with respect to 100 parts by weight of the cationically polymerizable compound. When the content of the thermosetting agent is 0.5 parts by weight or more, the resulting sealant for an organic EL display element has more excellent thermosetting properties. When the content of the thermosetting agent is 30 parts by weight or less, the resulting sealant for an organic EL display device has more excellent storage stability, and the cured product has more excellent moisture resistance. The lower limit of the content of the thermal hardening agent is more preferably 1 part by weight, and the upper limit is more preferably 15 parts by weight.

The sealing agent for organic EL display elements of the present invention preferably contains a stabilizer. By containing the above-mentioned stabilizer, the sealing agent for an organic EL display element of the present invention is more excellent in storage stability.

As the aforementioned stabilizer, aromatic amine compounds can be preferably used. As said aromatic amine compound, benzylamine, aminophenol type epoxy resin, etc. are mentioned, for example. As said aminophenol type epoxy resin, triglycidyl p-aminophenol etc. are mentioned. Among them, benzylamine is preferred. These stabilizers may be used alone or in combination of two or more kinds.

With respect to 100 parts by weight of the cationically polymerizable compound, the content of the stabilizer preferably has a lower limit of 0.001 parts by weight and a preferably upper limit of 2 parts by weight. When the content of the stabilizer is in this range, the resulting sealant for an organic EL display element maintains excellent curability and has more excellent storage stability. The lower limit of the content of the stabilizer is more preferably 0.005 part by weight, and the upper limit is more preferably 1 part by weight.

The sealing agent for organic EL display elements of the present invention may contain a silane coupling agent. The above-mentioned silane coupling agent has a function of improving the adhesiveness of the sealing agent for organic EL display elements of the present invention to a substrate or the like.

Examples of the above-mentioned silane coupling agent include: 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanate Group propyl trimethoxysilane and so on. These silane coupling agents may be used alone or in combination of two or more kinds.

The content of the silane coupling agent relative to 100 parts by weight of the cationic polymerizable compound has a preferred lower limit of 0.1 parts by weight and a preferred upper limit of 10 parts by weight. When the content of the silane coupling agent is in this range, the effect of suppressing the exudation of the excess silane coupling agent and improving the adhesion is more excellent. The lower limit of the content of the silane coupling agent is more preferably 0.5 parts by weight, and the upper limit is more preferably 5 parts by weight. In addition, from the viewpoint of low outgassing properties, the content of the silane coupling agent relative to 100 parts by weight of the cationically polymerizable compound has a preferred upper limit of 0.5 parts by weight, a more preferred upper limit of 0.1 parts by weight, and a more preferred upper limit of 0.01 parts by weight.

The sealing agent for organic EL display elements of the present invention may further contain a surface modifier within the range that does not impair the purpose of the present invention. By containing the above-mentioned surface modifier, the flatness of the coating film of the sealing agent for organic EL display elements of the present invention can be improved. As said surface modifier, surfactant, a leveling agent, etc. are mentioned, for example.

Examples of the above-mentioned surface modifier include silicone-based, acrylic-based, fluorine-based, and the like. As a commercially available one among the above-mentioned surface modifiers, for example, a surface modifier manufactured by BYK-Chemie Japan, a surface modifier manufactured by AGC Seimi Chemical, etc. can be cited. Examples of the surface modifier manufactured by BYK-Chemie Japan include BYK-330, BYK-340, BYK-345, and the like. As the surface modifier manufactured by AGC Seimi Chemical, for example, Surflon S-611 and the like can be cited.

The sealing agent for an organic EL display element of the present invention may contain a compound or ion exchange resin that reacts with the acid generated in the sealing agent for an organic EL display element in order to improve the durability of the element electrode within the range that does not impair the purpose of the present invention. .

As the above-mentioned compound that reacts with the generated acid, a substance neutralized with an acid, for example, a carbonate or bicarbonate of an alkali metal, or a carbonate or bicarbonate of an alkaline earth metal, etc. may be mentioned. Specifically, for example, calcium carbonate, calcium hydrogen carbonate, sodium carbonate, sodium hydrogen carbonate, etc. can be used.

As the above-mentioned 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 two-ion exchange type capable of adsorbing chloride ions is particularly preferable.

The sealant for an organic EL display element of the present invention may contain a solvent in order to adjust viscosity, etc. However, it may cause problems such as deterioration of the organic light-emitting material layer or outgassing due to the remaining solvent, so it is preferably free of solvent, or The content of the solvent is 0.05% by weight or less.

In addition, the sealant for organic EL display elements of the present invention may optionally contain various known additives such as curing retarders, reinforcing agents, softeners, plasticizers, viscosity modifiers, ultraviolet absorbers, and antioxidants.

The sealant for the organic EL display device of the present invention uses an E-type viscometer to measure the viscosity under the conditions of 25° C. and 2.5 rpm. The preferable upper limit of the viscosity is 2000 mPa·s. With the above viscosity being 2000 mPa·s or less, the resulting sealant for organic EL display devices has excellent coatability. The more preferable upper limit of the aforementioned viscosity is 1500 mPa·s, and the more preferable upper limit is 1000 mPa·s. In addition, a preferable lower limit of the aforementioned viscosity is 10 mPa·s. The above-mentioned viscosity can be measured on the cone plate of CP1 using VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) as an E-type viscometer, for example.

The preferred lower limit of the refractive index of the sodium D-line at 25°C of the cured product of the sealing agent for the organic EL display element of the present invention is 1.55. Since the refractive index is in this range, the refractive index difference with the electrode or the passivation film is small, and as a result, the obtained organic EL display device has excellent light extraction efficiency. A more preferable lower limit of the aforementioned refractive index is 1.56. The above-mentioned "refractive index of sodium D line" can be measured using an Abbe refractometer. In addition, as a cured product for measuring the aforementioned refractive index, for example, a measuring piece having a length of 20 mm, a width of 10 mm, and a thickness of about 0.5 to 1 mm can be used. If the cured product for measuring the above refractive index is a thermosetting sealant, it can be obtained by heating at 100°C for 30 minutes. If it is a photothermal curing sealant, it can be obtained by irradiating ultraviolet rays of about ^{2000 mJ/cm 2} It is obtained by heating at 100°C for 30 minutes.

The sealant for an organic EL display element of the present invention can be particularly preferably used as an in-plane sealant for coating and sealing a laminate having an organic light-emitting material layer. In addition, the sealing agent for organic EL display elements of the present invention can be preferably used for sealing top emission type organic EL display elements.

As a method of sealing an organic EL display element using the sealant for an organic EL display element of the present invention, for example, a method having the following steps: on the surface of the organic EL display element substrate, by printing, dispensing, or inkjet Etc., apply the sealant for an organic EL display element of the present invention to a substrate; and harden the applied sealant for an organic EL display element by heating and/or light irradiation.

In the step of applying the sealant for organic EL display elements of the present invention to a substrate, the sealant for organic EL display elements of the present invention may be applied to the entire surface of the substrate, or may be applied to a part of the substrate . The shape of the sealing portion of the sealant 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 atmosphere. To completely cover the shape of the laminated body, a closed pattern may be formed on the periphery of the laminated body, or a pattern of a shape with a part of openings may be formed on the periphery of the laminated body.

When the sealing agent for organic EL display elements is cured by heating, from the viewpoint of reducing damage to the laminate having the organic light-emitting material layer and curing it sufficiently, it is preferably at least 50°C And heating is performed below 120°C.

When the sealant for organic EL display elements of the present invention is cured by light irradiation, the sealant for organic EL display elements of the present invention can be irradiated with a wavelength of 300 nm or more and 400 nm or less and 300 mJ/cm ² The light with the cumulative amount of light above and below 3000 mJ/cm ^{2 makes it better hardened.}

As the light source for the above light irradiation, for example, low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, excimer laser, chemical lamp, black light lamp, microwave excited mercury lamp, metal halide lamp, sodium lamp, halogen Lamps, xenon lamps, LED lamps, fluorescent lamps, sunlight, electron beam irradiation devices, etc. These light sources may be used alone, or two or more types may be used in combination. The light sources are appropriately selected according to the absorption wavelength of the aforementioned photocationic polymerization initiator.

As means for irradiating the sealing agent for organic EL display element of the present invention with light, for example, simultaneous irradiation of various light sources, sequential irradiation with an interval time difference, combined irradiation of simultaneous irradiation and sequential irradiation, etc. can be used. Any irradiation means can be used.

The cured product obtained by the step of curing the above-mentioned sealant for an organic EL display element by heating and/or light irradiation can be further coated with an inorganic material film. As the inorganic material constituting the above-mentioned inorganic material film, conventionally known materials can be used, and examples thereof include silicon nitride (SiN _x ) or silicon _{oxide (SiO x} ). The above-mentioned inorganic material film may be one layer, or a plurality of layers may be laminated. In addition, the above-mentioned inorganic material film and the resin film composed of the sealing agent for an organic EL display element of the present invention may be alternately repeated to cover the above-mentioned laminate.

The method of manufacturing the above-mentioned organic EL display element may have a step of bonding a substrate coated with the sealing agent for an organic EL display element of the present invention (hereinafter, also referred to as "a substrate") and another substrate. The substrate on which the sealing agent for organic EL display elements of the present invention is applied (hereinafter, also referred to as "a substrate") may be a substrate on which a laminate having an organic light-emitting material layer is formed, or may not be formed on The base material of the laminate. When the one substrate is a substrate on which the laminate is not formed, the organic EL display element of the present invention is used for the organic EL display element of the present invention as long as the other substrate is bonded to protect the laminate from the outside atmosphere. The sealant may be applied to the above-mentioned one substrate. That is, when bonding another substrate, the sealant can be applied to the entire surface of the place that becomes the position of the laminate, or when bonding another substrate, the sealant part of the closed pattern can be formed so as to be completely contained. The shape of the location of the above-mentioned layered body. In addition, as a method of sealing the above-mentioned organic EL display element, a method of so-called dam filling sealing can be used. That is, the following method can be used: firstly, on the substrate of the organic EL display element, the curable paste is applied so as to surround the periphery of the display part; secondly, the present invention is applied to the inner side of the applied curable paste The sealant for organic EL display devices uses the curable paste on the periphery to prevent the sealant from overflowing, and the other side is attached to the opposite sealing substrate; then, the curable paste on the periphery is made by heating and/or light irradiation. The sealant for the organic EL display element of the present invention that has spread to the inside is hardened.

The step of curing the above-mentioned organic EL display device sealant by heating and/or light irradiation may be performed before the step of bonding the above-mentioned one substrate and the above-mentioned another substrate, or may be performed after bonding the above-mentioned one substrate and the above-mentioned substrate. The step of another substrate is carried out afterwards. When the step of curing the above-mentioned organic EL display device sealing agent by heating and/or light irradiation is performed before the step of laminating the above-mentioned one substrate and the above-mentioned another substrate, the sealing agent for the organic EL display device of the present invention is It is preferable that the application time from heating and/or light irradiation to the hardening reaction and failure to adhere to the agent is 1 minute or more. By the above-mentioned application time being 1 minute or more, before bonding the above-mentioned one base material and the above-mentioned another base material, it will not be over-hardened, and higher bonding strength can be obtained.

In the step of bonding the one substrate and the another substrate, the method for bonding the one substrate and the another substrate is not particularly limited, and bonding is preferably performed under a reduced pressure environment. The preferred lower limit of the vacuum degree under the aforementioned reduced pressure environment is 0.01 kPa, and the preferred upper limit is 10 kPa. With the vacuum degree in the above reduced pressure environment in this range, it does not take a long time to achieve the vacuum state by the airtightness of the vacuum device or the ability of the vacuum pump, so that the bonding of the above-mentioned substrate and the above-mentioned substrate can be removed more efficiently. Bubbles in the sealing compound for organic EL display elements of the present invention when another substrate is used. [Effects of Invention]

According to the present invention, it is possible to provide a sealing agent for an organic EL display element which is excellent in low outgassing properties and coating properties, and can obtain an organic EL display element having excellent light extraction efficiency.

The following examples are given to illustrate the present invention in more detail, but the present invention is not limited to these examples.

(Examples 1 to 8, Comparative Examples 1 to 4) In accordance with the blending ratios described in Tables 1 and 2, each material was stirred and mixed with a stirring mixer at a stirring speed of 2000 rpm to produce each of the sealing agents for organic EL display elements of Examples 1 to 8 and Comparative Examples 1 to 4. As the stirring mixer, AR-250 (manufactured by Thinky) was used.

＜Evaluation＞ The following evaluations were performed on each of the sealing agents for organic EL display elements obtained in the examples and comparative examples. The results are shown in Tables 1 and 2.

(1) Viscosity For each organic EL display device sealant obtained in the Examples and Comparative Examples, the viscosity under the conditions of 25° C. and 2.5 rpm was measured using an E-type viscometer. As the E-type viscometer, VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) was used.

(2) Coatability To 100 parts by weight of each organic EL display device sealant obtained in the Examples and Comparative Examples, 0.3 parts by weight of polymer beads with an average particle diameter of 10 μm were added, and they were uniformly dispersed using a planetary stirring device. As the polymer beads, Micropearl SP (manufactured by Sekisui Chemical Co., Ltd.) was used. Prepare 2 glass substrates with a length of 5 cm and a width of 5 cm. Place 0.1 mL of the resulting dispersion on the center of a glass substrate, and measure the diameter of the diffusion after 30 seconds. If the diameter is 5.5 mm or more is marked as "◎", if the diameter is greater than 5.0 mm and less than 5.5 mm is marked as "○", if the diameter is greater than 4.5 mm and less than 5.0 mm is marked as "△", The case of less than 4.5 mm is recorded as "×", and the spreadability is evaluated.

(3) Curability The reaction rate at the time of curing was determined for each of the sealing agents for organic EL display elements obtained in the Examples and Comparative Examples. The sealing compounds for organic EL display elements obtained in Examples 1 to 4, 6, 8 and Comparative Examples 1 to 4 were subjected to the measurement of the reaction calorie using differential scanning calorimetry (manufactured by Hitachi High-Tech Science, "DSC6220"). The reaction rate was calculated using the following calculation formula (I). In the calculation formula (I), H ₀ is the heat of reaction when the aluminum sample pan is used in a nitrogen environment and the heating rate is 10°C/min in the unhardened state from 40°C to 200°C. In addition, in the calculation formula (I), H ₁ is the heat of reaction when the sealant for an organic EL display device is heated at 100° C. for 30 minutes to harden it from 40° C. to 200° C. at a heating rate of 10° C./min. (H _0- H ₁ )/H ₀ (I) In addition, for the organic EL display device sealing compound obtained in Examples 5 and 7, Photo-DSC (manufactured by TA Instruments, "DSC Q100" and light source device " Qseries PCA” combination), the reaction calorie is measured when irradiated with active energy rays and when the temperature is raised, and the reaction rate is calculated using the following calculation formula (II). In the calculation formula (II), H ₂ uses a high-pressure mercury lamp (without cut-off filter), irradiates an active energy line of 1.5 J/cm ^{2 with an illuminance of 3.7 W/cm 2 under a nitrogen environment at 25°C. After irradiation} Immediately use the heating rate of 10°C/min from 40°C to 200°C for the total calorific value before the active energy ray is irradiated to the end of the temperature rise. The above-mentioned cumulative light quantity is obtained by measuring the cumulative light quantity with a wavelength of 351 nm using UV-351 (manufactured by ORC). In addition, in the calculation formula (II), H ₃ is irradiated with active energy rays under the above-mentioned conditions and immediately raised to 100°C at a heating rate of 20°C/min, kept at 100°C for 30 minutes, and then cooled to 25°C at 10°C/min. ℃, and then heating up to 200℃ at a heating rate of 10℃/min after cooling to 25℃ to 200℃ at the end of heating (H ₃ ). (H ₂ －H ₃ )/H ₂ (II) If the reaction rate is more than 90%, mark it as "◎", if it is over 80% and less than 90%, mark it as "○", and mark it as 60% or more and The case of less than 80% is recorded as "△", the case of less than 60% is recorded as "×", and the hardening property is evaluated.

(4) Refractive index and light extraction efficiency The polysiloxane rubber sheet with a thickness of 1 mm is punched into a rectangle with a length of 20 mm and a width of 10 mm to make a mold. The mold was placed on a release PET film, and after each organic EL display device sealant obtained in the examples and comparative examples was filled in the mold, another release PET film was covered so that no air bubbles remained. Obtain a laminated body. The obtained laminate is sandwiched between two glass plates and fixed to harden the sealant. The sealants for organic EL display elements obtained in Examples 1 to 4, 6, 8 and Comparative Examples 1 to 4 were heated at 100°C for 30 minutes to harden, and the organic EL display obtained in Examples 5 and 7 was displayed The sealant for components is cured by irradiating 1500 mJ/cm ² of ultraviolet rays with a wavelength of 365 nm with a UV-LED, and then heating it at 90°C for 30 minutes. After that, the PET film was peeled off, and the cured product of the sealant was taken out from the silicone rubber sheet to obtain a test piece with a length of 10 mm, a width of 20 mm, and a thickness of 1 mm. The obtained test piece was used to measure the refractive index of the sodium D-line at 25° C. using an Abbe refractometer. As the Abbe refractometer, NAR-4T (manufactured by Atago Corporation) was used. In addition, considering the difference in refractive index with the electrode or the passivation film, the case where the refractive index is 1.56 or higher is marked as "○", the case where the refractive index is higher than 1.54 and less than 1.56 is marked as "△", and the case less than 1.54 is recorded as "×", evaluate the light extraction efficiency.

(5) Low outgassing. Weigh 300 mg of each organic EL display device sealant obtained in the Examples and Comparative Examples, and seal them in a small glass bottle to harden them. The sealants for organic EL display elements obtained in Examples 1 to 4, 6, 8 and Comparative Examples 1 to 4 were cured by heating at 100°C for 30 minutes, and the organic EL display elements obtained in Examples 5 and 7 Use the sealant to irradiate 1500 mJ/cm ² of 365 nm ultraviolet rays with a UV-LED, and then heat it at 90°C for 30 minutes to harden it. Furthermore, the vial was heated in a constant temperature oven at 85°C for 100 hours, and the amount of vaporized components in the vial was measured using a gas chromatography mass spectrometer. As a gas chromatography mass spectrometer, JMS-Q1050 (manufactured by JEOL Ltd.) was used. If the amount of vaporized components is less than 50 ppm, mark it as "○", if it is more than 50 ppm and less than 100 ppm, mark it as "△", and if it is 100 ppm or more, mark it as "×" to evaluate low outgassing. .

[Table 1] Example 1 2 3 4 5 6 7 8 Composition (parts by weight) Cationic polymerizable compound Oxidized cycloalkene type alicyclic epoxy compound 3,4-Epoxycyclohexyl carboxylic acid 3',4'-epoxycyclohexyl methyl ester (manufactured by Daicel, "Celloxide 2021P") 5 - 40 40 40 35 10 40 Bis(3,4-epoxycyclohexane-1-ylmethyl) adipate (manufactured by Sun Chemical, "TTA26") - 10 - - - - - - Compound with biphenyl skeleton and epoxy group O-phenylphenol glycidyl ether (manufactured by Yokkaichi Gosei Co., Ltd., "OPP-EP") 95 90 60 60 60 50 70 15 Compounds with biphenyl skeleton and oxetanyl group The compound represented by formula (1) (manufactured by Ube Industries Co., Ltd., "ETERNACOLL OXBP") - - - - - - - 45 other Chrysanthemum type epoxy compound (manufactured by Osaka Gas Chemicals, "OGSOL EG-200") - - - - - 15 - - 3-Ethyl-3-(((3-ethyloxetan-3-yl)methoxy)methyl)oxetane (manufactured by Toagosei Co., Ltd., "ARONOXETANE OXT-221") - - - - - - 20 - Phenyl glycidyl ether - - - - - - - - Bisphenol F epoxy compound (manufactured by DIC Corporation, "EPICLON EXA-830LVP") - - - - - - - - Cationic polymerization initiator Thermal cationic polymerization initiator Borate-based quaternary ammonium salt (manufactured by King Industries, "CXC-1821") 1 1 1 - - 1 - 1 Antimonate series quaternary ammonium salt (manufactured by King Industries, "CXC-1612") - - - 1 - - - - Photocationic polymerization initiator Borate-based alumium salt (manufactured by Midori Kagaku Corporation, "DTS-200") - - - - 1 - 1 - Evaluation Viscosity (mPa·s) 200 220 210 210 210 600 100 900 Coatability ◎ ◎ ◎ ◎ ◎ ○ ◎ ○ Hardening ○ ○ ◎ ○ ◎ ○ ○ ○ Refractive index (light extraction efficiency) 1.62 (○) 1.62 (○) 1.58 (○) 1.58 (○) 1.58 (○) 1.60 (○) 1.59 (○) 1.58 (○) Low outgassing ○ ○ ○ ○ ○ ○ ○ ○

[Table 2] Comparative example 1 2 3 4 Composition (parts by weight) Cationic polymerizable compound Oxidized cycloalkene type alicyclic epoxy compound 3,4-Epoxycyclohexyl carboxylic acid 3',4'-epoxycyclohexyl methyl ester (manufactured by Daicel, "Celloxide 2021P") 96 - 30 50 Bis(3,4-epoxycyclohexane-1-ylmethyl) adipate (manufactured by Sun Chemical, "TTA26") - - - - Compound with biphenyl skeleton and epoxy group O-phenylphenol glycidyl ether (manufactured by Yokkaichi Gosei Co., Ltd., "OPP-EP") - 100 - - Compounds with biphenyl skeleton and oxetanyl group The compound represented by formula (1) (manufactured by Ube Industries Co., Ltd., "ETERNACOLL OXBP") - - - - other Chrysanthemum type epoxy compound (manufactured by Osaka Gas Chemicals, "OGSOL EG-200") - - - - 3-Ethyl-3-(((3-ethyloxetan-3-yl)methoxy)methyl)oxetane (manufactured by Toagosei Co., Ltd., "ARONOXETANE OXT-221") 4 - - - Phenyl glycidyl ether - - - 50 Bisphenol F epoxy compound (manufactured by DIC Corporation, "EPICLON EXA-830LVP") - - 70 - Cationic polymerization initiator Thermal cationic polymerization initiator Borate-based quaternary ammonium salt (manufactured by King Industries, "CXC-1821") 1 1 1 1 Antimonate series quaternary ammonium salt (manufactured by King Industries, "CXC-1612") - - - - Photocationic polymerization initiator Borate-based alumium salt (manufactured by Midori Kagaku Corporation, "DTS-200") - - - - Evaluation Viscosity (mPa·s) 230 200 1300 40 Coatability ◎ ◎ 〇 ◎ Hardening ◎ X X ○ Refractive index (light extraction efficiency) 1.53 (×) 1.63 (○) 1.58 (○) 1.55 (△) Low outgassing ○ ○ ○ X [Industrial availability]

According to the present invention, it is possible to provide a sealing agent for an organic EL display element which is excellent in low outgassing properties and coating properties, and can obtain an organic EL display element having excellent light extraction efficiency.

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Claims (7)

A sealant for organic EL display elements, It contains a cationic polymerizable compound and a cationic polymerization initiator, The above-mentioned cationically polymerizable compound includes a cycloalkane oxide type alicyclic epoxy compound and a compound having a biphenyl skeleton and an epoxy group or an oxetanyl group. The sealant for organic EL display elements of claim 1, wherein the content of the oxidized cycloolefin-type alicyclic epoxy compound in 100 parts by weight of the cationic polymerizable compound is 3 parts by weight or more and 45 parts by weight or less, The content of the compound having a biphenyl skeleton and an epoxy group or an oxetanyl group is 30 parts by weight or more and 97 parts by weight or less. The sealing agent for organic EL display elements according to claim 1 or 2, wherein the cationic polymerizable compound is excluding the oxidized cycloolefin-type alicyclic epoxy compound and the above-mentioned biphenyl skeleton and epoxy group or oxetanyl group In addition to the compound, it also includes other cationic polymerizable compounds. The sealing agent for organic EL display element according to claim 3, which contains a 3-ethyl-3-(((3-ethyloxetan-3-yl)methoxy)methyl)oxa At least one of the group consisting of cyclobutane, 1,2:7,8-diepoxy octane, and 1, 2:5, 6-diepoxycyclooctane is used as the above-mentioned other cationic polymerizable compound. The sealing agent for organic EL display element according to claim 4, which contains 3-ethyl-3-(((3-ethyloxetan-3-yl)methoxy)methyl)oxetine Alkanes are used as the above-mentioned other cationically polymerizable compounds. The sealing agent for organic EL display element of 4 or 5, wherein the content of the other cationically polymerizable compound in 100 parts by weight of the cationically polymerizable compound is 10 parts by weight or more and 50 parts by weight or less. The sealing agent for organic EL display elements of 2, 3, 4, 5, or 6, wherein the cationic polymerization initiator contains a quaternary ammonium salt of a borate type relative to the anion.