JP6530767B2 - Sealant for organic electroluminescent display device - Google Patents

Description

The present invention relates to a sealing agent for an organic electroluminescent display element, which is excellent in adhesiveness to a flexible substrate and the like and can suppress display defects due to deterioration of the element.

BACKGROUND ART In recent years, research on organic light devices using organic thin film elements such as organic electroluminescence (hereinafter, also referred to as “organic EL”) display elements and organic thin film solar cell elements has been advanced. The organic thin film element can be easily manufactured by vacuum deposition, solution coating or the like, and therefore, is excellent in productivity.

The organic EL display element has a thin film structure in which an organic light emitting material layer is sandwiched between a pair of electrodes facing each other. Electrons are injected from one electrode into the organic light emitting material layer and holes are injected from the other electrode, whereby the electrons and holes are combined in the organic light emitting material layer to perform self-emission. Compared with a liquid crystal display element or the like which requires a backlight, it has the advantages of high visibility, capable of being thinned, and capable of direct current low voltage driving.

However, such an organic EL display element has a problem that when the organic light emitting material layer or the electrode is exposed to the outside air, the light emitting characteristics thereof are rapidly deteriorated and the life becomes short. Therefore, for the purpose of enhancing the stability and durability of the organic EL display device, in the organic EL display device, a sealing technique for shielding the organic light emitting material layer and the electrode from moisture and oxygen in the air becomes indispensable. There is.

Patent Document 1 discloses a method of filling a sealing agent between organic EL display element substrates and sealing them in a top emission type organic EL display element or the like. However, the conventional sealing agent has a problem that it is easy to deteriorate the element by generating outgassing during and after curing.

JP 2001-357973 A

An object of the present invention is to provide a sealing agent for an organic electroluminescent display element which is excellent in adhesiveness to a flexible substrate and the like and which can suppress display defects due to deterioration of the element.

The present invention is a sealing agent for an organic electroluminescent display element containing a cationically polymerizable compound and a cationic polymerization initiator, and the cationically polymerizable compound has a cationically polymerizable group and an ether bond or an ester bond. And, when the ether bond or the ester bond is hydrolytically cleaved, all the decomposition products contain a hydrolyzable cationically polymerizable compound having a cationically polymerizable group, and weigh 300 mg in a vial. Sealed and heated at 100 ° C for 30 minutes for curing, or irradiated with UV light at 1500 mJ / cm ² , then heated at 80 ° C for 30 minutes for curing, and then heated at 85 ° C for 100 hours for outgas generation It is a sealing agent for organic electroluminescent display elements which is 100 ppm or less.
The present invention will be described in detail below.

The inventor of the present invention has found that the cause of outgassing in the conventional sealing agent is that the ether bond or ester bond of the cationically polymerizable compound contained in the sealing agent is hydrolyzed by the acid derived from the polymerization initiator or the like. I thought it was. Then, although the present inventor examined using a thing which does not have an ether bond and an ester bond as a cationically polymerizable compound, although the obtained sealing agent was able to suppress generation | occurrence | production of out gas, a cure shrinkage was large. In particular, adhesion to a flexible substrate etc. was not sufficiently obtained. Then, as a result of the present inventor's earnest examination, as a result of having cationically polymerizable group and an ether bond or ester bond, and also when this ether bond or ester bond is cut by hydrolysis, all the decomposition products are cationically polymerized. By using a hydrolyzable cationically polymerizable compound having a hydrophobic group and setting the amount of outgas generated at curing and after curing to a specific value or less, the adhesive property to a flexible substrate etc. is excellent, and a device It has been found that it is possible to obtain a sealing agent for an organic EL display element which can suppress display defects due to the deterioration of the present invention, and the present invention has been completed.

The sealant for an organic EL display element of the present invention is metered and sealed in a vial at 300 mg, heated at 100 ° C. for 30 minutes for curing, or irradiated with UV light at 1500 mJ / cm ² and then at 80 ° C. The upper limit of the amount of outgas generation when heated for 30 minutes for curing and further heated at 85 ° C. for 100 hours is 100 ppm. Since the said outgas generation amount is 100 ppm or less, the sealing compound for organic EL display elements of this invention can fully suppress the display defect by deterioration of an element. The upper limit of the amount of outgas generation is preferably 50 ppm, more preferably 30 ppm.
The amount of outgas generation is preferably as small as possible, and the lower limit is not particularly limited, but it is substantially 5 ppm or more.
The amount of outgassing can be measured using a gas chromatograph mass spectrometer (for example, JMS-Q1050 (manufactured by Nippon Denshi Co., Ltd.) or the like).

The sealing agent for an organic EL display element of the present invention contains a cationically polymerizable compound.
The cationically polymerizable compound has a cationically polymerizable group and an ether bond or an ester bond, and when the ether bond or the ester bond is cleaved by hydrolysis, all the decomposition products are cationically polymerizable groups. The hydrolyzable cationically polymerizable compound (hereinafter, also referred to as "the hydrolyzable cationically polymerizable compound according to the present invention") is contained. The hydrolyzable cationically polymerizable compound according to the present invention does not have too large cure shrinkage due to having an ether bond or an ester bond, and the obtained sealant for an organic EL display element is excellent in adhesion to a flexible substrate etc. Also, when the ether bond or the ester bond is cleaved by hydrolysis, all the decomposition products having a cationically polymerizable group can prevent the decomposition products from causing outgassing.
By using the hydrolyzable cationically polymerizable compound according to the present invention as the above cationically polymerizable compound and not using other components that cause outgassing, or by using a small amount even when using it The amount of outgas generation can be in the range described above.

As said cationically polymerizable group, an epoxy group, oxetanyl group, vinyl ether group etc. are mentioned, for example. Among them, epoxy group is preferable.

Specific examples of the hydrolyzable cationically polymerizable compound according to the present invention include 3 ', 4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (compound represented by the following formula (1)) , 3-ethyl-3 (((3-ethyl oxetan-3-yl) methoxy) methyl) oxetane (compound represented by the following formula (2)), diglycidyl 4,5-epoxycyclohexane-1,2-dicarboxylate (The compound represented by following formula (3)) etc. are mentioned. Among them, an alicyclic epoxy compound having an ether bond or an ester bond is preferable, because the obtained sealing agent for an organic EL display element is excellent in adhesion to a flexible substrate or the like, and the following formula (1) or The compound represented by Formula (2) is more preferable, and the compound represented by following formula (1) is still more preferable.

Among the hydrolyzable cationically polymerizable compounds according to the present invention, commercially available ones include, for example, Celoxide 2021P (manufactured by Daicel), OXT-221 (manufactured by Toagosei Co., Ltd.), and the like.

The sealing agent for an organic EL display device of the present invention is a cationically polymerizable compound having no ether bond and no ester bond, an ether bond or an ester as other cationically polymerizable compounds, as long as the object of the present invention is not impaired. Although at least a part of the degradable product may contain a cationically polymerizable compound having no cationically polymerizable property when the ether bond or the ester bond of those having a bond is cleaved by hydrolysis, the flexible substrate etc. It is preferable not to contain the above-mentioned other cationically polymerizable compounds from the viewpoint of achieving both the adhesiveness and the effect of suppressing display defects due to the deterioration of the device.

When the other cationically polymerizable compound is contained, the present invention is based on 100 parts by weight of the cationically polymerizable compound from the viewpoint of achieving both the adhesiveness to the flexible substrate etc. and the effect of suppressing display defects due to the deterioration of the device. The lower limit of the content of the hydrolyzable cationically polymerizable compound is preferably 20 parts by weight, more preferably 50 parts by weight, and still more preferably 70 parts by weight.

The sealing agent for an organic EL display element of the present invention contains a cationic polymerization initiator.
As said cationic polymerization initiator, the photocationic polymerization initiator which generate | occur | produces a protic acid or a Lewis acid by light irradiation, The thermal cationic polymerization initiator which generate | occur | produces a protic acid or a Lewis acid by heating is mentioned. If it is these, it will not specifically limit, It may be an ionic acid generation type, and a non-ionic acid generation type may be sufficient.

Among the above-mentioned photocationic polymerization initiators, as the photocationic polymerization initiator of the ionic photoacid generation type, for example, the anion moiety is BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , or (BX ₄ ) ⁻ (wherein , X represents a phenyl group substituted with at least two or more fluorine or trifluoromethyl groups), an aromatic sulfonium salt, an aromatic iodonium salt, an aromatic diazonium salt, an aromatic ammonium salt, or And (2,4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -Fe salt and the like.

Examples of the aromatic sulfonium salt include bis (4- (diphenylsulfonio) phenyl) sulfide bishexafluorophosphate, bis (4- (diphenylsulfonio) phenyl) sulfide bishexafluoroantimonate, bis (4- (diphenyl) Diphenylsulfonio) phenyl) sulfide bis tetrafluoroborate, bis (4- (diphenylsulfonio) phenyl) sulfide tetrakis (pentafluorophenyl) borate, diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate, diphenyl-4- (4) Phenylthio) phenylsulfonium hexafluoroantimonate, diphenyl-4- (phenylthio) phenylsulfonium tetrafluoroborate, diphenyl-4- (phenylthio) Phenylsulfonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, bis (4- (di ( 4- (2-hydroxyethoxy)) phenylsulfonio) phenyl) sulfide bishexafluorophosphate, bis (4- (di (4- (2-hydroxyethoxy) phenylsulfonio) phenyl) sulfide bishexafluoroantimonate, Bis (4- (di (4- (2-hydroxyethoxy)) phenylsulfonio) phenyl) sulfide bis tetrafluoroborate, bis (4- (di ( - (2-hydroxyethoxy)) phenylsulfonio) phenyl) sulfide tetrakis (pentafluorophenyl) borate, and the like.

Examples of the aromatic iodonium salt include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis (pentafluorophenyl) borate, bis (dodecylphenyl) iodonium hexafluorophosphate, bis (Dodecylphenyl) iodonium hexafluoroantimonate, bis (dodecylphenyl) iodonium tetrafluoroborate, bis (dodecylphenyl) iodonium tetrakis (pentafluorophenyl) borate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium hexame Fluorophosphate, 4-methylphenyl-4- (1-methylethyl) Henyliodonium hexafluoroantimonate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrafluoroborate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) borate, etc. It can be mentioned.

Examples of the aromatic diazonium salt include phenyl diazonium hexafluorophosphate, phenyl diazonium hexafluoro antimonate, phenyl diazonium tetrafluoroborate, phenyl diazonium tetrakis (pentafluorophenyl) borate and the like.

Examples of the above-mentioned aromatic ammonium salt include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2-cyanopyridinium tetrafluoroborate, 1-benzyl 2-Cyanopyridinium tetrakis (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 (2,4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -Fe salt, for example, (2,4-cyclopentadien-1-yl) ((1-methylethyl) benzene ) -Fe (II) hexafluorophosphate, (2,4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -Fe (II) hexafluoroantimonate, (2,4-cyclopentadiene-1) -Yl) ((1-methylethyl) benzene) -Fe (II) tetrafluoroborate, (2,4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -Fe (II) tetrakis (penta) And fluorophenyl) borate and the like.

Examples of the nonionic photoacid-generating photocationic polymerization initiator include nitrobenzyl ester, sulfonic acid derivative, phosphoric acid ester, phenol sulfonic acid ester, diazonaphthoquinone, N-hydroxyimidosulfonate and the like.

Among the above cationic photopolymerization initiators, commercially available ones are, for example, DTS-200 (manufactured by Midori Kagaku Co., Ltd.), UVI 6990, UVI 6974 (all manufactured by Union Carbide), SP-150, SP-170 (all of them) Adeka company make, FC-508, FC-512 (all are 3M company make), Irgacure 290 (BASF company make), PI 2074 (made by Rhodia company) etc. are mentioned.

As said thermal cationic polymerization initiator, the anionic part is substituted by BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , or (BX ₄ ) ⁻ (wherein X is at least two or more fluorine or trifluoromethyl groups) And a sulfonium salt, a phosphonium salt, a quaternary ammonium salt, a diazonium salt, or an iodonium salt.

Examples of the sulfonium salt include triphenylsulfonium boron tetrafluoride, triphenylsulfonium antimony antimony hexafluoride, triphenylsulfonium arsenic arsenic hexafluoride, tri (4-methoxyphenyl) sulfonium arsenic arsenic hexafluoride, diphenyl (4-phenylthiophenyl) And sulfone hexafluoride arsenic and the like.

Examples of the phosphonium salt include ethyl triphenyl phosphonium antimony hexafluoride, tetrabutyl phosphonium antimony hexafluoride and the like.

Examples of the quaternary ammonium salt include dimethylphenyl (4-methoxybenzyl) ammonium hexafluorophosphate, dimethylphenyl (4-methoxybenzyl) ammonium hexafluoroantimonate, dimethylphenyl (4-methoxybenzyl) ammonium tetrakis (penta) Fluorophenyl) borate, dimethylphenyl (4-methylbenzyl) ammonium hexafluorophosphate, dimethylphenyl (4-methylbenzyl) ammonium hexafluoroantimonate, dimethylphenyl (4-methylbenzyl) ammonium hexafluorotetrakis (pentafluorophenyl) borate , Methylphenyl dibenzyl ammonium, methyl phenyl dibenzyl ammonium hexafluoroantimo Methyl hexafluorophosphate, methylphenyldibenzylammonium tetrakis (pentafluorophenyl) borate, phenyltribenzylammonium tetrakis (pentafluorophenyl) borate, dimethylphenyl (3,4-dimethylbenzyl) ammonium tetrakis (pentafluorophenyl) borate, N, N-Dimethyl-N-benzylanilinium antimony hexafluoride, N, N-diethyl-N-benzylanilinium boron tetrafluoride, N, N-dimethyl-N-benzylpyridinium antimony hexafluoride, N, N And -diethyl-N-benzylpyridinium trifluoromethanesulfonic acid and the like.

Among the above thermal cationic polymerization initiators, commercially available ones are, for example, SAN-AID SI-60, SAN-AID SI-80, SAN-AID SI-B3, SAN-AID SI-B3A, SAN-AID SI-B4 (all of which are San Shin Chemical Industry Co., Ltd.) C., CXC-1612, CXC-1821 (all are manufactured by King Industries), and the like.

Among them, the cationic polymerization initiator preferably contains a quaternary ammonium salt because the resulting sealing agent for an organic EL display element can further suppress the generation of outgassing.

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

The sealing agent for an organic EL display element of the present invention may contain other components in addition to the above-mentioned cationically polymerizable compound and the above-mentioned cationic polymerization initiator, as long as the object of the present invention is not hindered.

The sealing agent for an organic EL display element of the present invention contains a silane coupling agent as the other component for the purpose of improving the adhesion between the sealing agent for an organic EL display element of the present invention and a substrate or the like. Although it is preferable, it is preferable not to contain a silane coupling agent from the viewpoint of suppressing the generation of outgassing.

Examples of the silane coupling agent include 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-isocyanatopropyltrimethoxysilane. These silane coupling agents may be used alone or in combination of two or more.

When the silane coupling agent is contained, the upper limit of the content of the silane coupling agent is preferably 0.5 parts by weight with respect to 100 parts by weight of the cationically polymerizable compound. When the content of the silane coupling agent is 0.5 parts by weight or less, higher adhesion improvement effect can be exhibited while suppressing the generation of outgassing and bleeding out of the excess silane coupling agent. A more preferable upper limit of the content of the silane coupling agent is 0.1 parts by weight.

The sealant for an organic EL display element of the present invention may contain a stabilizer as the other component from the viewpoint of improving storage stability.
As said stabilizer, amine-type compounds, such as a benzylamine, etc. are mentioned, for example.

The sealing agent for organic EL display elements of this invention may contain a thermosetting agent as said other component.
Examples of the thermosetting agent include hydrazide compounds, imidazole derivatives, acid anhydrides, dicyandiamides, guanidine derivatives, modified aliphatic polyamines, and addition products of various amines and epoxy resins.
Examples of the hydrazide compound include 1,3-bis (hydrazinocarbonoethyl-5-isopropylhydantoin) and the like.
Examples of the imidazole derivatives include 1-cyanoethyl-2-phenylimidazole, N- (2- (2-methyl-1-imidazolyl) ethyl) urea, 2,4-diamino-6- (2′-methylimidazolyl (1 ′))-Ethyl-s-triazine, N, N′-bis (2-methyl-1-imidazolylethyl) urea, N, N ′-(2-methyl-1-imidazolylethyl) -adipamide, 2- Examples include phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole and the like.
Examples of the acid anhydride include tetrahydrophthalic anhydride, ethylene glycol-bis (anhydrotrimellitate) and the like.
These thermosetting agents may be used alone or in combination of two or more.

The sealant for an organic EL display element of the present invention may contain a surface modifier as the other component. By containing the said surface modifier, the flatness of the coating film of the sealing agent for organic EL display elements of this invention can be improved.
As said surface modifier, surfactant, a leveling agent, etc. are mentioned, for example.

Examples of the surface modifier include those of silicone type, acrylic type and fluorine type.
Among the above surface modifiers, commercially available ones are, for example, BYK-302, BYK-331 (all of which are manufactured by Big Chemie Japan), UVX-272 (manufactured by Kushimoto Chemical Co., Ltd.), Surfron S-611 (manufactured by Kushimoto Chemical Co., Ltd.) AGC Seimi Chemical Co., Ltd.) and the like.

The sealing agent for an organic EL display element of the present invention, as the other component, is a compound or ion exchange that reacts with an acid generated in the sealing agent for an organic EL display element to improve the durability of the element electrode. It may contain a resin.

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

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

Moreover, the sealing agent for organic EL display elements of this invention is a hardening retarder, a reinforcing agent, a softener, a plasticizer, a viscosity modifier, an ultraviolet absorber, an antioxidant as needed as the said other component. May contain various known additives such as.

As a method of manufacturing the sealing agent for organic EL display elements of this invention, a cationically polymerizable compound is used, for example using mixers, such as a homodisperser, a homomixer, a universal mixer, a planetary mixer, a kneader, 3 rolls, etc. And a method of mixing a cationic polymerization initiator and other components to be added as needed.

The preferable lower limit of the viscosity measured using an E-type viscometer at 25 ° C. is 5 mPa · s, and the preferable upper limit is 500 mPa · s. When the viscosity is in this range, the sealant for an organic EL display element of the present invention is more excellent in coatability. The more preferable lower limit of the viscosity is 10 mPa · s, and the more preferable upper limit is 100 mPa · s.
The viscosity is, for example, VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) as an E-type viscometer, and a cone plate of CP1 is used to appropriately rotate at 1 to 100 rpm according to the optimum torque number in each viscosity region. It can be measured by selecting.

The sealant for an organic EL display element of the present invention is particularly suitably used as an in-plane sealant for covering and sealing a laminate having an organic light emitting material layer.

According to the present invention, it is possible to provide a sealant for an organic electroluminescence display element which is excellent in adhesion to a flexible substrate and the like and which can suppress display defects due to deterioration of the element.

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

Example 1
As a hydrolyzable cationically polymerizable compound according to the present invention, 100 parts by weight of a compound represented by the above formula (1) ("Celloxide 2021 P" manufactured by Daicel Corporation) and dimethylphenyl (4-methoxy) as a thermal cationic polymerization initiator Stirring speed 3000 rpm using a stirring mixer (Shinky Co., Ltd., "AR-250") and 0.5 parts by weight of benzyl) ammonium tetrakis (pentafluorophenyl) borate (King Industries, Inc., "CXC-1821") The mixture was uniformly stirred and mixed to prepare a sealing agent for an organic EL display element.
The obtained sealant for an organic EL display element was weighed in a vial and sealed in a vial of 300 mg, and cured by heating at 100 ° C. for 30 minutes. Furthermore, this vial is heated in a constant temperature oven at 85 ° C. for 100 hours, and the vaporized component in the vial is regarded as an outgas generation amount, and measurement is performed using a gas chromatograph mass spectrometer (“JMS-Q1050” manufactured by Nippon Denshi Co., Ltd.) did. The results are shown in Table 1.

( Examples 4, 6, Reference Examples 2 , 3 , 5 , Comparative Examples 1 to 3)
The materials described in Table 1 are mixed by stirring in the same manner as in Example 1 according to the compounding ratios described in Table 1, and Examples 4, 6, Reference Examples 2 , 3 , 5 and Comparative Examples 1 to 4 The sealing agent for organic EL display elements of 3 was produced.
About each obtained obtained sealing agent for organic EL display elements, it carried out similarly to Example 1, and measured outgas generation amount. The results are shown in Table 1. The sealant obtained in Reference Example 2 was irradiated with UV light at 1500 mJ / cm ² instead of heating at 100 ° C. for 30 minutes, and then cured by heating at 80 ° C. for 30 minutes.

<Evaluation>
The following evaluation was performed about each sealing agent for organic EL display elements obtained by the Example , the reference example, and the comparative example. The results are shown in Table 1.

(1) Viscosity The sealant for an organic EL display device obtained in each of the examples , reference examples and comparative examples was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., “VISCOMETER TV-22”) 25 The viscosity at ° C was measured.

(2) Adhesiveness to a flexible substrate The sealing agent for organic EL display elements obtained in Examples, Reference Examples and Comparative Examples is taken in the center of a 20 mm × 50 mm polycarbonate plate (manufactured by Takiron Co., Ltd.) by a very small amount. A polycarbonate plate of the same size was placed on top of that and the sealant was spread. In that state, the sealant is cured ( Examples 1, 4, 6, Reference Examples 3 and 5, and each sealant obtained in Comparative Examples 1 to 3 are cured by heating at 100 ° C. for 30 minutes, reference The sealant obtained in Example 2 was irradiated with UV light at 1500 mJ / cm ² and then cured by heating at 80 ° C. for 30 minutes to obtain an adhesion test piece. The adhesive strength of the obtained adhesion test piece was measured using EZgraph (manufactured by Shimadzu Corporation). At that time, those with an adhesive strength of 1.0 kgf / cm ² or more are “○”, those with an adhesive strength of 0.5 kgf / cm ² or more and less than 1.0 kgf / cm ² are “Δ”, adhesive strength The adhesive property to the flexible substrate was evaluated by setting “x” to that of which was less than 0.5 kgf / cm ² .

(3) Curability The sealants for organic EL display elements obtained in Examples, Reference Examples, and Comparative Examples were cured ( Examples 1, 4, 6, 6, 3, 4, 5, and Comparative Examples 1 to 5) . Each sealant obtained in 3 was cured by heating at 100 ° C. for 30 minutes, and the sealant obtained in Reference Example 2 was cured by heating at 80 ° C. for 30 minutes after irradiation with UV light at 1500 mJ / cm ² The calorific value before and after curing at the time of curing was measured using a DSC apparatus (manufactured by Agilent Technologies, “UMA 600”), and the reaction rate of the epoxy group was derived from the following formula.
Reaction rate of epoxy group (%) = 100 × (heat amount before curing−heat amount after curing) / heat amount before curing When the reaction rate of epoxy group is 90% or more, “○”, 70% The case where it was more than 90% or more was evaluated as "(triangle | delta)", and the case where it was less than 70% was evaluated as "x".

(4) Display performance of organic EL display element (preparation of a substrate on which a laminate having an organic light emitting material layer is disposed)
An ITO electrode was formed into a film of 1000 Å in thickness on a glass substrate (length 30 mm, width 30 mm, thickness 0.7 mm). The substrate is ultrasonically cleaned with acetone, an aqueous alkaline solution, ion-exchanged water, and isopropyl alcohol for 15 minutes, respectively, and then washed with boiled isopropyl alcohol for 10 minutes, and then a UV-ozone cleaner (manufactured by Nippon Laser Electronics Co., Ltd.) The last treatment was performed with "NL-UV253").
Next, this substrate is fixed to a substrate holder of a vacuum deposition apparatus, and 200 mg of N, N'-di (1-naphthyl) -N, N'-diphenylbenzidine (.alpha.-NPD) in the crucible of the unglazed pot, and other different 200 mg of tris (8-quinolinolato) aluminum (Alq ₃ ) was put in an unglazed pan, and the inside of the vacuum chamber was depressurized to 1 × 10 ⁻⁴ Pa. Thereafter, the crucible containing α-NPD was heated, and α-NPD was deposited on the substrate at a deposition rate of 15 Å / s to form a hole transport layer having a film thickness of 600 Å. Next, the crucible containing Alq ₃ was heated to form an organic light emitting material layer having a film thickness of 600 Å at a deposition rate of 15 Å / s. After that, the substrate on which the hole transport layer and the organic light emitting material layer were formed was transferred to another vacuum deposition apparatus, and 200 mg of lithium fluoride was added to the tungsten resistance heating boat in this vacuum deposition apparatus, and aluminum was used for another tungsten boat. I put a line 1.0g. Thereafter, the pressure in the deposition chamber of the vacuum deposition apparatus is reduced to 2 × 10 ^-4 Pa to form lithium fluoride 5 Å at a deposition rate of 0.2 Å / s, and then aluminum is deposited at a rate of 20 Å / s and 1000 Å. did. The inside of the vaporizer was returned to normal pressure by nitrogen, and the substrate on which the laminate having the organic light emitting material layer was disposed was taken out.

(Coating with inorganic material film A)
A mask having an opening was placed to cover the entire laminate of the substrate on which the obtained laminate was disposed, and an inorganic material film A was formed by plasma CVD.
In the plasma CVD method, SiH ₄ gas and nitrogen gas are used as source gases, the flow rates are 10 sccm for SiH ₄ gas and 200 sccm for nitrogen gas, RF power is 10 W (frequency 2.45 GHz), chamber temperature is 100 ° C., chamber The internal pressure was 0.9 Torr.
The thickness of the formed inorganic material film A was about 1 μm.

(Formation of resin protective film)
80 pL of the sealing agent for organic EL display elements obtained in Examples, Reference Examples and Comparative Examples was applied to a glass substrate by an ink jet method using an ink jet discharge device (manufactured by Microjet, “Nanoprinter 300”) It applied by discharge amount. At the time of application, the film thickness was adjusted to be 20 μm or less. Next, the sealant for an organic EL display element is cured (each sealant obtained in Examples 1 , 4, 6, Reference Examples 3 and 5, and Comparative Examples 1 to 3 is heated at 100 ° C. for 30 minutes. The sealant obtained in Reference Example 2 was irradiated with UV light at 1500 mJ / cm ² and then cured by heating at 80 ° C. for 30 minutes to form a resin protective film.

(Coating with inorganic material film B)
After forming a resin protective film, a mask having an opening was placed to cover the entire resin protective film, and an inorganic material film B was formed by plasma CVD to obtain an organic EL display device.
In the plasma CVD method, SiH ₄ gas and nitrogen gas are used as source gases, the flow rates are 10 sccm for SiH ₄ gas and 200 sccm for nitrogen gas, RF power is 10 W (frequency 2.45 GHz), chamber temperature is 100 ° C., chamber The internal pressure was 0.9 Torr.
The thickness of the formed inorganic material film B was about 1 μm.

(Light emitting state of organic EL display element)
The obtained organic EL display device was exposed for 100 hours under the conditions of a temperature of 85 ° C. and a humidity of 85%, and then a voltage of 10 V was applied to visually observe the light emission state (the presence or absence of light emission and dark spots) of the device. . The case where light was uniformly emitted without dark spots and peripheral quenching was evaluated as “o”, the case where dark spots and peripheral quenching were observed was evaluated as “Δ”, and the case where the non-light emitting portion was significantly enlarged was evaluated as “x”.

According to the present invention, it is possible to provide a sealant for an organic electroluminescence display element which is excellent in adhesion to a flexible substrate and the like and which can suppress display defects due to deterioration of the element.

Claims (4)

It is a sealing agent for organic electroluminescent display elements (however, except curable resin sheet) containing a cationically polymerizable compound and a thermal cationic polymerization initiator,
The cationically polymerizable compound has a cationically polymerizable group and an ether bond or an ester bond, and when the ether bond or the ester bond is cleaved by hydrolysis, all the decomposition products are cationically polymerizable groups. Containing a hydrolyzable cationically polymerizable compound,
The hydrolyzable cationically polymerizable compound contains an alicyclic epoxy compound having an ether bond or an ester bond,
Measure 300 mg in a vial and seal, cure by heating at 100 ° C for 30 minutes, or irradiate UV light at 1500 mJ / cm ² , then cure by heating at 80 ° C for 30 minutes, and further, at 85 ° C The amount of outgassing after heating for 100 hours is 50 ppm or less ,
A sealing agent for an organic electroluminescent display element, having a viscosity of 5 mPa · s or more and 500 mPa · s or less measured at 25 ° C. using an E-type viscometer. The alicyclic epoxy compound which has an ether bond or an ester bond is a compound represented by following formula (1), Sealing agent for organic electroluminescent display elements of Claim 1 characterized by the above-mentioned.

The sealing agent for an organic electroluminescent display element according to claim 1 or 2, wherein a content of the hydrolyzable cationically polymerizable compound in 100 parts by weight of the whole cationically polymerizable compound is 20 parts by weight or more. The sealing agent for organic electroluminescent display elements according to claim 1, 2 or 3, wherein the thermal cationic polymerization initiator contains a quaternary ammonium salt.