WO2019203180A1 - Sealant for organic el display element - Google Patents

Abstract

The purpose of the present invention is to provide a sealant for organic EL display elements that has excellent coating properties, rapid curability, low outgassing properties, and excellent storage stability, and that enables organic EL display elements having excellent display properties to be obtained. The present invention provides a sealant for an organic EL display element that includes a curable resin and a thermal cationic polymerization initiator, wherein the curable resin includes an alicyclic epoxy compound and an oxetane compound, the time until the rise of an exothermic peak after holding at 100°C when the temperature of the curable resin is raised at a temperature increase rate of 40°C/minute and held at 100°C, as measured by differential scanning calorimetry, is 3 minutes or less, and the viscosity increase rate after storage for 4 days in an environment of 40°C and 22.5% RH is 20% or less.

Description

Sealant for organic EL display element

The present invention relates to a sealant for an organic EL display device that can provide an organic EL display device that is excellent in coating properties, fast curing properties, low outgassing properties, storage stability, and display performance.

An organic electroluminescence display element (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. When electrons are injected from one electrode into the organic light emitting material layer and holes are injected from the other electrode, electrons and holes are combined in the organic light emitting material layer to perform self-light emission. Compared with a liquid crystal display element or the like that requires a backlight, the visibility is better, the thickness can be reduced, and direct current low voltage driving is possible.

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

Patent Document 1 includes an organic filling layer made of an in-plane sealing agent that covers and seals a laminate having an organic light emitting material layer, and a peripheral sealing agent containing a moisture absorbent, and the organic filling layer A method of sealing an organic EL display element by a configuration having a moisture-absorbing seal layer covering the side surfaces of the organic EL display device is disclosed.

JP 2014-67598 A

However, when the organic EL display element is encapsulated using the organic EL display element encapsulant of Patent Document 1, there is a problem that display defects such as dark spots may occur in the obtained organic EL display element. .
The present invention provides an organic EL display element sealant that can provide an organic EL display element that is excellent in coating properties, fast curability, low outgassing properties, storage stability, and display performance. With the goal.

The present invention contains a curable resin and a thermal cationic polymerization initiator, the curable resin contains an alicyclic epoxy compound and an oxetane compound, and a temperature increase rate of 40 ° C./min in differential scanning calorimetry. The temperature from holding at 100 ° C. until the rise of the exothermic peak is 3 minutes or less, and stored for 4 days in an environment of 40 ° C. and 22.5% RH. It is the sealing agent for organic EL display elements whose viscosity increase rate after having been 20% or less.
The present invention is described in detail below.

The present inventor considers that the cause of display defects such as dark spots in the organic EL display element is that the sealing agent used generates outgas, and the organic EL display is made of a material having excellent low outgassing properties. An investigation was made on sealing an organic EL display element using an element sealing agent. However, even when a sealant excellent in low outgassing property is used, display defects such as dark spots may occur in the obtained organic EL display element. In addition to generation of outgas, the present inventor has a laminate having an organic light emitting material layer by reducing the viscosity of the organic EL display element sealant used as an in-plane sealant upon heating such as curing. It was thought that the penetration of the organic EL display element caused the display defect. Accordingly, the present inventor has proposed a low curable resin and thermal polymerization initiator used for the sealant in order to improve the fast curability of the sealant for organic EL display elements and prevent penetration into the laminate. We considered using not only the outgassing property but also the excellent reactivity. However, the obtained sealant has a problem that it tends to thicken and is inferior in storage stability. Therefore, the present inventor used a combination of an alicyclic epoxy compound and an oxetane compound as a curable resin, and further, the time until the rise of the exothermic peak when the differential scanning calorimetry of the sealant was measured, It was examined to adjust the thickening rate after storage for 4 days in an environment of 22.5% RH to a specific value or less. As a result, it is possible to obtain an organic EL display element sealing agent that is excellent in all of coating properties, fast curability, low outgassing properties, and storage stability, and by using the organic EL display element sealing agent. The present inventors have found that an organic EL display element having excellent display performance can be obtained, and have completed the present invention.

The sealing agent for organic EL display elements of the present invention is heated at a rate of 40 ° C./min in differential scanning calorimetry, held at 100 ° C. when held at 100 ° C., and until the rise of the exothermic peak. The time (hereinafter also referred to as “curing start time”) is 3 minutes or less. By the said hardening start time being 3 minutes or less, the sealing agent for organic EL display elements of this invention is excellent in quick curability, and the obtained organic EL display element becomes excellent in display performance. The curing start time is preferably 2.5 minutes or less, and more preferably 2 minutes or less.
The differential scanning calorimetry was performed using a differential scanning calorimeter and a holding temperature of 100 ° C. using a differential scanning calorimeter in an environment of 25 ° C. and 50% RH for 10 mg of sealant placed in an aluminum pan. It can be measured under the measurement condition of ° C. Examples of the differential scanning calorimeter include Thermo plus DSC 8230 (manufactured by Rigaku).

The sealing agent for organic EL display elements of the present invention has a viscosity increase rate of 20% or less after storage for 4 days in an environment of 40 ° C. and 22.5% RH. When the viscosity increase rate is 20% or less, the organic EL display element sealing agent of the present invention can be used stably over a long period of time. The viscosity increase rate is preferably 15% or less, more preferably 10% or less, and most preferably 0%.
In the present specification, the above “thickening rate” means that the viscosity immediately after production (before storage) is A, and the viscosity after storage for 4 days in an environment of 40 ° C. and 22.5% RH is B. It is a value calculated by the following formula.
Thickening rate (%) = ((BA) ÷ A) × 100
In the present specification, the “viscosity” means a value measured using an E-type viscometer under the conditions of 25 ° C. and 20 rpm. Examples of the E-type viscometer include VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.), and a CP1 cone plate can be used.

The above-mentioned curing start time and the above thickening rate are the ranges described above by selecting these types and adjusting the content ratios of other components such as a curable resin, a thermal cationic polymerization initiator, and a stabilizer described later. It can be.

The sealing agent for organic EL display elements of this invention contains curable resin.
The curable resin contains an alicyclic epoxy compound and an oxetane compound. When each of the alicyclic epoxy compound and the oxetane compound is used alone, the resulting organic EL display element encapsulant is inferior in fast curability or the like. By using in combination, it becomes easy to make the said hardening start time and the said thickening rate into the range mentioned above.

Examples of the alicyclic epoxy compound include 3,4-epoxycyclohexylmethyl (meth) acrylate, 1,2: 8,9-diepoxy limonene, 4-vinylcyclohexene monooxide, vinylcyclohexene dioxide, and methylated vinyl. Cyclohexene dioxide, (3,4-epoxycyclohexyl) methyl-3,4-epoxycyclohexylcarboxylate, bis (3,4-epoxycyclohexylmethyl) ether, 3,4,3 ′, 4′-diepoxycyclohexyl, Examples thereof include bis (3,4-epoxycyclohexyl) adipate, bis (2,3-epoxycyclopentyl) ether, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, and dicyclopentadiene dioxide. Especially, since it becomes easier to adjust the hardening start time and the viscosity increase rate of the sealing agent for organic EL display elements obtained by using in combination with the oxetane compound described later, the alicyclic epoxy compound is 3,4-epoxycyclohexylmethyl (meth) acrylate is preferably contained.
In the present specification, the “(meth) acrylate” means acrylate or methacrylate.

Examples of the oxetane compound include 4,4′-bis ((3-ethyl-3-oxetanyl) methoxymethyl) biphenyl and 3-ethyl-3-(((3-ethyloxetane-3-yl) methoxy) methyl. ) Oxetane, phenoxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3- (phenoxymethyl) oxetane, 3-ethyl-3-((2-ethylhexyloxy) methyl) oxetane, 3-ethyl- 3-((3- (triethoxysilyl) propoxy) methyl) oxetane, oxetanylsilsesquioxane, phenol novolac oxetane, 1,4-bis (((3-ethyl-3-oxetanyl) methoxy) methyl) benzene and the like Can be mentioned. Especially, since it becomes easier to adjust the viscosity of the sealing agent for organic EL display elements obtained by using in combination with the alicyclic epoxy compound, the curing start time, and the thickening rate, The oxetane compound comprises at least 4,4′-bis ((3-ethyl-3-oxetanyl) methoxymethyl) biphenyl and 3-ethyl-3-(((3-ethyloxetane-3-yl) methoxy) methyl) oxetane. It is preferable to include any of them.

The minimum with the preferable content rate of the said alicyclic epoxy compound in the sum total of the said alicyclic epoxy compound and the said oxetane compound is 20 weight%, and a preferable upper limit is 80 weight%. When the content rate of the said alicyclic epoxy compound is this range, it becomes easier to adjust the viscosity of the obtained sealing agent for organic EL display elements, hardening start time, and a thickening rate. The minimum with more preferable content rate of the said alicyclic epoxy compound is 30 weight%, and a more preferable upper limit is 70 weight%.

The said curable resin may contain other curable resin for the purpose of viscosity adjustment etc. in the range which does not inhibit the objective of this invention.
As said other curable resin, other epoxy compounds other than the said alicyclic epoxy compound, a vinyl ether compound, etc. are mentioned, for example.
Examples of the other epoxy compounds include dicyclopentadiene dimethanol diglycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, and the like. .
Examples of the vinyl ether compound include benzyl vinyl ether, cyclohexane dimethanol monovinyl ether, dicyclopentadiene vinyl ether, 1,4-butanediol divinyl ether, cyclohexane dimethanol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, dipropylene glycol. Examples thereof include divinyl ether and tripropylene glycol divinyl ether.

The sealing agent for organic EL display elements of this invention contains a thermal cationic polymerization initiator.
As the thermal cationic polymerization initiator, the anion portion (counter anion) is BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , or (BX ₄ ) ⁻ (where X is at least two fluorines or trifluoro And a sulfonium salt, a phosphonium salt, an ammonium salt, etc., which represent a phenyl group substituted with a methyl group. Especially, since it becomes easier to adjust the curing start time and the thickening rate of the obtained sealing agent for organic EL display elements and it is excellent in low outgassing property, the quaternary in which the counter anion is a borate system. Ammonium salts (hereinafter also referred to as “borate quaternary ammonium salts”) are preferred. The counter anion of the borate quaternary ammonium salt is preferably BF ₄ ^- or (BX ₄ ) ^- .

Examples of the sulfonium salt include triphenylsulfonium tetrafluoroborate and triphenylsulfonium hexafluoroantimonate.

Examples of the phosphonium salt include ethyltriphenylphosphonium hexafluoroantimonate and tetrabutylphosphonium hexafluoroantimonate.

Examples of the ammonium salt include 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 hexafluorotetrakis (pentafluorophenyl) borate, methylphenyl Dibenzylammonium hexafluorophosphate, methylphenyldibenzylammonium Safluoroantimonate, methylphenyldibenzylammonium tetrakis (pentafluorophenyl) borate, phenyltribenzylammonium tetrakis (pentafluorophenyl) borate, dimethylphenyl (3,4-dimethylbenzyl) ammonium tetrakis (pentafluorophenyl) borate, N , N-dimethyl-N-benzylanilinium hexafluoroantimonate, N, N-diethyl-N-benzylanilinium tetrafluoroborate, N, N-dimethyl-N-benzylpyridinium hexafluoroantimonate, N, N-diethyl -N-benzylpyridinium trifluoromethanesulfonic acid and the like. Among them, dimethylphenyl (4-methoxybenzyl) ammonium tetrakis is more easily adjusted for the curing start time and the thickening rate of the obtained sealing agent for organic EL display elements and excellent in low outgassing properties. (Pentafluorophenyl) borate is preferred.

Examples of commercially available thermal cationic polymerization initiators include thermal cationic polymerization initiators manufactured by Sanshin Chemical Industry, thermal cationic polymerization initiators manufactured by King Industries, and the like.
Examples of the thermal cationic polymerization initiator manufactured by Sanshin Chemical Industry Co., Ltd. include Sun-Aid SI-60, Sun-Aid SI-80, Sun-Aid SI-B3, Sun-Aid SI-B3A, and Sun-Aid SI-B4.
Examples of the thermal cationic polymerization initiator manufactured by King Industries include CXC1612 and CXC1821.

The content of the thermal cationic polymerization initiator is preferably 0.05 parts by weight and preferably 10 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the thermal cationic polymerization initiator is within this range, the obtained sealing agent for organic EL display elements is more excellent in fast curability and storage stability. The minimum with more preferable content of the said thermal cationic polymerization initiator is 0.1 weight part, and a more preferable upper limit is 5 weight part.

The sealing agent for organic EL display elements of this invention may contain a thermosetting agent in the range which does not inhibit the objective of this invention. Examples of the thermosetting agent include hydrazide compounds, imidazole derivatives, acid anhydrides, dicyandiamides, guanidine derivatives, modified aliphatic polyamines, addition products of various amines and epoxy resins, and the like.

Examples of the hydrazide compound include 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin, sebacic acid dihydrazide, isophthalic acid dihydrazide, adipic acid dihydrazide, malonic acid dihydrazide, 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 and 2-phenyl-4,5-dihydroxymethylimidazole.
Examples of the acid anhydride include tetrahydrophthalic anhydride, ethylene glycol bis (anhydrotrimellitate), and the like.
These thermosetting agents may be used independently and 2 or more types may be used together.

As what is marketed among the said thermosetting agents, the thermosetting agent by an Otsuka Chemical company, the thermosetting agent by Ajinomoto Fine Techno Co., etc. are mentioned, for example.
Examples of the thermosetting agent manufactured by Otsuka Chemical Co., Ltd. include SDH and ADH.
Examples of the thermosetting agent manufactured by Ajinomoto Fine Techno Co. include Amicure VDH, Amicure VDH-J, Amicure UDH, and the like.

The content of the thermosetting agent is preferably 0.5 parts by weight and preferably 30 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the thermosetting agent is within this range, the obtained sealant for an organic EL display element sealant is more excellent in thermosetting while maintaining excellent storage stability. The minimum with more preferable content of the said thermosetting agent is 1 weight part, and a more preferable upper limit is 15 weight part.

It is preferable that the sealing agent for organic EL display elements of this invention contains a stabilizer. By containing the said stabilizer, the sealing agent for organic EL display elements of this invention becomes a thing excellent in storage stability more.

Examples of the stabilizer include amine compounds such as benzylamine and aminophenol type epoxy resins.

The preferable lower limit of the content of the stabilizer is 0.001 part by weight and the preferable upper limit is 2 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the stabilizer is within this range, the obtained sealing agent for organic EL display elements is more excellent in storage stability while maintaining excellent fast curability. The minimum with more preferable content of the said stabilizer is 0.005 weight part, and a more preferable upper limit is 1 weight part.

The sealing agent for organic EL display elements of the present invention may contain a silane coupling agent. The said silane coupling agent has a role which improves the adhesiveness of the sealing agent for organic EL display elements of this invention, a board | substrate, etc.

Examples of the silane coupling agent include 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane, and the like. These silane coupling agents may be used independently and 2 or more types may be used together.

The content of the silane coupling agent is preferably 0.1 parts by weight and preferably 10 parts by weight with respect to 100 parts by weight of the curable resin. When the content of the silane coupling agent is within this range, it is more excellent in the effect of improving the adhesiveness of the obtained sealing agent for organic EL display elements while preventing bleed-out of excess silane coupling agent. It becomes. The minimum with more preferable content of the said silane coupling agent is 0.5 weight part, and a more preferable upper limit is 5 weight part.

The sealing agent for organic EL display elements of the present invention may contain a surface modifier as long as the object of the present invention is not impaired. 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.
Examples of the surface modifier include surfactants and leveling agents.

Examples of the surface modifier include silicone-based, acrylic-based, and fluorine-based ones.
Examples of commercially available surface modifiers include BYK-300, BYK-302, BYK-331 (all manufactured by Big Chemie Japan), UVX-272 (manufactured by Enomoto Kasei), Surflon. S-611 (manufactured by AGC Seimi Chemical Co., Ltd.) and the like.

The encapsulant for organic EL display elements of the present invention reacts with the acid generated in the encapsulant for organic EL display elements in order to improve the durability of the element electrode within a range not impairing the object of the present invention. You may contain a compound or an ion exchange resin.

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

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

Moreover, the sealing agent for organic EL display elements of this invention is a range which does not inhibit the objective of this invention, and is a hardening retarder, a reinforcing agent, a softener, a plasticizer, a viscosity modifier, and an ultraviolet absorber as needed. Further, various known additives such as antioxidants may be contained.

It is preferable that the sealing agent for organic EL display elements of this invention does not contain a solvent from a viewpoint of suppressing generation | occurrence | production of outgas. Even if the sealing agent for organic EL display elements of this invention does not contain this solvent, it is easy to make it excellent in applicability | paintability.

As a method for producing the sealing agent for organic EL display elements of the present invention, for example, using a mixer such as a homodisper, homomixer, universal mixer, planetary mixer, kneader, three rolls, And a method of mixing a thermal cationic polymerization initiator and an additive such as a stabilizer or a silane coupling agent added as necessary.

The sealing agent for organic EL display elements of the present invention has a preferred lower limit of 10 mPa · s and a preferred upper limit of 500 mPa · s measured using an E-type viscometer at 25 ° C. and 20 rpm. When the viscosity is within this range, the obtained sealing agent for organic EL display elements is excellent in applicability and is particularly suitable as an in-plane sealing agent for organic EL display elements. A more preferable lower limit of the viscosity is 30 mPa · s, and a more preferable upper limit is 250 mPa · s.

The sealing agent for organic EL display elements of the present invention is particularly preferably used as an in-plane sealing agent that covers and seals a laminate having an organic light emitting material layer.

ADVANTAGE OF THE INVENTION According to this invention, the sealing agent for organic EL display elements which can obtain the organic EL display element which is excellent in applicability | paintability, fast-curing property, low outgas property, and storage stability and is excellent in display performance is provided. can do.

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

(Examples 1 to 8, Comparative Examples 1 to 9)
According to the blending ratios described in Tables 1 and 2, the materials were uniformly stirred and mixed at a stirring speed of 3000 rpm using a stirring mixer (“AR-250” manufactured by Shinky Corporation). Sealants for organic EL display elements of Comparative Examples 1 to 9 were prepared.
10 mg of the obtained sealing agent for organic EL display element was put in an aluminum pan, and the temperature was increased by using a differential scanning calorimeter (manufactured by Rigaku, “Thermo plus DSC 8230”) in an environment of 25 ° C. and 50% RH. Differential scanning calorimetry was performed under the measurement conditions of a temperature rate of 40 ° C./min and a holding temperature of 100 ° C. Tables 1 and 2 show the time from the holding at 100 ° C. to the rise of the exothermic peak (curing start time).
Moreover, about the obtained sealing agent for organic EL display elements, the viscosity immediately after manufacture (before storage) and the viscosity after storage for 4 days in an environment of 40 ° C. and 22.5% RH are measured. The thickening rate was calculated from the formula. The results are shown in Tables 1 and 2. In addition, what was gelatinized was described as "gel" instead of the value of the viscosity. The viscosity was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., “VISCOMETER TV-22”) on a CP1 type cone plate at 25 ° C. and 20 rpm.

<Evaluation>
The following evaluation was performed about each sealing agent for organic EL display elements obtained by the Example and the comparative example. The results are shown in Tables 1 and 2.

(1) Using an applicator pipette, 0.1 mL of each organic EL display element sealant obtained in Examples and Comparative Examples was applied onto a glass substrate, and the diameter that spread after 1 minute was measured. When the diameter was 15 mm or more, the applicability was evaluated as “◯”, when the diameter was 10 mm or more and less than 15 mm, “Δ”, and when it was less than 10 mm, “×”.

(2) 300 mg of each organic EL display element sealant obtained in the low outgassing Examples and Comparative Examples was weighed and sealed in a vial, and then cured by heating at 100 ° C. for 30 minutes. It was. Furthermore, this vial was heated in a constant temperature oven at 85 ° C. for 100 hours, and the vaporized components in the vial were measured using a gas chromatograph mass spectrometer (“JMS-Q1050” manufactured by JEOL Ltd.). The low outgassing property was evaluated as “◯” when the vaporized component amount was less than 50 ppm, “Δ” when it was 50 ppm or more and less than 100 ppm, and “X” when it was 100 ppm or more.

(3) Display performance of organic EL display element (production of a substrate on which a laminate having an organic light emitting material layer is disposed)
A glass substrate (length 45 mm, width 45 mm, thickness 0.7 mm) on which an ITO electrode was formed to a thickness of 1000 mm was used as the substrate. The substrate was ultrasonically washed with acetone, an aqueous alkali solution, ion-exchanged water, and isopropyl alcohol for 15 minutes, respectively, then washed with boiled isopropyl alcohol for 10 minutes, and 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 (α-NPD) is put into an unglazed crucible in other different ways. 200 mg of tris (8-quinolinolato) aluminum (Alq ₃ ) was put in an unglazed crucible, 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 ｓ / s to form a 600 正 孔 hole transport layer. Next, the crucible containing Alq ₃ was heated to form an organic light emitting material layer having a thickness of 600 で at a deposition rate of 15 Å / s. Thereafter, the substrate on which the hole transport layer and the organic light emitting material layer are formed is transferred to another vacuum vapor deposition apparatus, and 200 mg of lithium fluoride is added to a tungsten resistance heating boat in the vacuum vapor deposition apparatus, and aluminum is added to another tungsten boat. 1.0 g of wire was added. After that, the inside of the vapor deposition unit of the vacuum vapor deposition apparatus is depressurized to 2 × 10 ⁻⁴ Pa to form a lithium fluoride film with a thickness of 5 mm at a deposition rate of 0.2 kg / s, and then aluminum with a film thickness of 1000 mm at a rate of 20 kg / s. did. The inside of the vapor deposition unit was returned to normal pressure with nitrogen, and the substrate on which the laminate having the organic light emitting material layer of 10 mm × 10 mm was arranged was taken out.

(Production of organic EL display element)
E-W207 (manufactured by Sekisui Chemical Co., Ltd.) is applied to the outer periphery of the substrate on which the laminate is placed so that the line width is 6 mm. After applying each sealing agent for organic EL display elements obtained in the example so as to cover the entire laminate, another glass substrate (length 45 mm, width 45 mm, thickness 0.7 mm) was overlaid. Then, 3000 mJ / cm < ² > ultraviolet-ray was irradiated, and also in-plane sealing agent and periphery sealing agent were hardened by heating at 100 degreeC for 30 minutes, and produced the organic EL display element.

(Light emission state of organic EL display element)
The obtained organic EL display element was exposed to an environment of 85 ° C. and 85% RH for 1000 hours, and then a voltage of 10 V was applied to change the light emission state of the organic EL display element (whether dark spots and pixel periphery were quenched). It was observed visually. Organic light-emitting diode display with “○” when there is no dark spot or peripheral quenching, “△” when dark spot or peripheral quenching is observed slightly, and “×” when non-light emitting part is significantly enlarged The display performance of the device was evaluated.

ADVANTAGE OF THE INVENTION According to this invention, the sealing agent for organic EL display elements which can obtain the organic EL display element which is excellent in applicability | paintability, fast-curing property, low outgas property, and storage stability and is excellent in display performance is provided. can do.

Claims (5)

Containing a curable resin and a thermal cationic polymerization initiator,
The curable resin contains an alicyclic epoxy compound and an oxetane compound,
In differential scanning calorimetry, the temperature is increased at a rate of temperature increase of 40 ° C./min, and the time from holding at 100 ° C. when held at 100 ° C. until the rise of the exothermic peak is 3 minutes or less, and
An encapsulant for organic EL display elements, wherein the viscosity increase ratio after storage for 4 days in an environment of 40 ° C. and 22.5% RH is 20% or less. The encapsulant for an organic EL display device according to claim 1, wherein the alicyclic epoxy compound contains 3,4-epoxycyclohexylmethyl (meth) acrylate. The oxetane compounds include 4,4′-bis ((3-ethyl-3-oxetanyl) methoxymethyl) biphenyl and 3-ethyl-3-(((3-ethyloxetane-3-yl) methoxy) methyl) oxetane. The sealing agent for organic EL display elements of Claim 1 or 2 containing at least any. 4. The organic EL display element seal according to claim 1, wherein the content of the alicyclic epoxy compound in the total of the alicyclic epoxy compound and the oxetane compound is 20% by weight or more and 80% by weight or less. Stopper. The sealing agent for organic EL display elements according to claim 1, 2, 3, or 4, wherein the thermal cationic polymerization initiator is a quaternary ammonium salt whose counter anion is a borate system.