JP5703429B1 - Sealant for organic EL display element - Google Patents

Abstract

An object of this invention is to provide the sealing agent for organic EL display elements which can suppress generation | occurrence | production of outgas and is excellent in applicability | paintability. The present invention is an organic EL display element sealing agent containing a cationic curable resin and a cationic polymerization initiator, the cationic curable resin having an epoxy group or an oxetanyl group, and an epoxy group Or it does not have an ether bond other than what is contained in an oxetanyl group, and an ester bond, The sealing agent for organic EL display elements measured on 25 degreeC and the conditions of 1-100 rpm using the E-type viscosity meter It is the sealing agent for organic EL display elements whose whole viscosity is 80-5000 mPa * s.

Description

The present invention relates to a sealant for organic EL display elements that can suppress the generation of outgas and is excellent in applicability.

In recent years, research on organic optical devices using organic thin film elements such as organic electroluminescence (organic EL) display elements and organic thin film solar cell elements has been advanced. The organic thin film element can be easily produced by vacuum deposition, solution coating, or the like, and thus has excellent 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. 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 discloses a method of sealing a top emission organic EL display element by filling a curable adhesive between organic EL display element substrates and irradiating light. However, when a display element such as an organic EL display element is sealed using a curable adhesive in this way, outgas is generated during light irradiation or heating and fills the element, accelerating deterioration of the element. There was a problem that sometimes.

JP 2001-357773 A

An object of this invention is to provide the sealing agent for organic EL display elements which can suppress generation | occurrence | production of outgas and is excellent in applicability | paintability.

The present invention is an organic EL display element sealing agent containing a cationic curable resin and a cationic polymerization initiator, wherein the cationic curable resin has an epoxy group or an oxetanyl group, and an epoxy group. Or an ether bond other than that contained in the oxetanyl group and an ester bond , and a compound represented by the following formula (1) and a compound represented by the following formula (2): It is the sealing agent for organic EL display elements whose viscosity of the whole sealing agent for organic EL display elements measured on condition of 25 degreeC and 1-100 rpm using a meter is 80-5000 mPa * s.
The present invention is described in detail below.

The present inventors considered that the cause of outgas generation when a curable adhesive is used for sealing an organic EL display element is an ether bond or an ester bond contained in the curable resin used. That is, it was considered that the outgas was generated by the decomposition of the ether bond or the ester bond contained in the curable resin with an acid derived from an initiator or the like. For this reason, the use of a curable resin that does not contain an ether bond or an ester bond that causes outgassing was studied. Depending on the type of curable resin to be used, the obtained sealing agent for organic EL display elements was applied. It may become inferior.
Therefore, the present inventors have specified a cationic curable resin having an epoxy group or an oxetanyl group as the curable resin and not having an ether bond and an ester bond other than those contained in the epoxy group or oxetanyl group. As a result, it was found that outgassing can be suppressed and a sealing agent for organic EL display elements having excellent coating properties can be obtained, and the present invention has been completed.

The sealing agent for organic EL display elements of the present invention contains a cationic curable resin.
The cationic curable resin has an epoxy group or an oxetanyl group and does not have an ether bond and an ester bond other than those contained in the epoxy group or the oxetanyl group (hereinafter referred to as “cationic curing according to the present invention”). Also referred to as “resin”.

The cation curable resin preferably contains a compound represented by the following formula (1) and / or a compound represented by the following formula (2), since generation of outgas can be effectively suppressed. From the viewpoint of curability and curing, it is more preferable to contain a compound represented by the following formula (1).

In formula (1), R ^{1 to} R ¹⁸ are a hydrogen atom, a halogen atom, or a hydrocarbon group that may contain an oxygen atom or a halogen atom, and may be the same or different. Also good.

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

In formula (3-1), R ²² represents a hydrogen atom or a methyl group.

Since the said cationic curable resin shows favorable cationic curability, it is preferable to contain the compound represented by following formula (4) as a compound represented by the said Formula (1).

The cationic curable resin contains a compound represented by the following formula (5) as a compound represented by the above formula (2) because it exhibits good cationic curability and the cured product exhibits a high glass transition temperature. It is preferable to do.

Since the cationic curable resin can easily adjust the curing retardation and viscosity of the obtained sealing agent for organic EL display elements, it is represented by the compound represented by the above formula (1) and the above formula (2). It is preferred to contain both compounds. Further, by containing the compound represented by the above formula (2) in addition to the compound represented by the above formula (1), it is possible to suppress the volatilization of the raw material until the curing reaction occurs, and to obtain the organic Application shape stability of the sealing agent for EL display elements is improved.

When the cationic curable resin contains both the compound represented by the formula (1) and the compound represented by the formula (2), it is represented by the compound represented by the formula (1) and the formula (2). The content ratio with the compound is, by weight ratio, the compound represented by the formula (1): the compound represented by the formula (2) = 1: 99 to 99: 1 from the viewpoints of the retarding property and the coating property. It is preferable that the compound represented by the formula (1): the compound represented by the formula (2) = 10: 90 to 90:10.

Other examples of the cationic curable resin according to the present invention include dicyclopentadiene diepoxide and 1,2,5,6-diepoxycyclooctane.

The sealing agent for organic EL display elements of the present invention increases the dispersibility of the filler described later and moderately adjusts the viscosity of the resulting sealing agent for organic EL display elements within a range that does not impair the object of the present invention. For the purpose of, etc., in addition to the cationic curable resin according to the present invention, other cationic curable resins having an ether bond or an ester bond other than those contained in the epoxy group or oxetanyl group may be contained.
The other cationic curable resin is at least one selected from the group consisting of an epoxy resin having a bisphenol skeleton, an epoxy resin having a novolac skeleton, an epoxy resin having a naphthalene skeleton, and an epoxy resin having a dicyclopentadiene skeleton. A kind of epoxy resin is preferable, an epoxy resin having a bisphenol skeleton is more preferable, and a bisphenol F-type epoxy resin is still more preferable.

When the other cation curable resin is contained, the content of the cation curable resin according to the present invention is preferably 10 parts by weight and preferably 80 parts by weight with respect to 100 parts by weight of the whole cation curable resin. It is. When the content of the cationic curable resin according to the present invention is less than 10 parts by weight or more than 80 parts by weight, the obtained sealing agent for organic EL display elements may be inferior in applicability. The more preferable lower limit of the content of the cationic curable resin according to the present invention is 20 parts by weight, and the more preferable upper limit is 70 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 a photocationic polymerization initiator that generates a protonic acid or a Lewis acid by light irradiation, and a thermal cationic polymerization initiator that generates a protonic acid or a Lewis acid by heating. These are not particularly limited as long as they are ionic acid generating types or nonionic acid generating types.

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

Examples of the ionic photoacid-generating photocationic polymerization initiator include a cation moiety that is aromatic sulfonium, aromatic iodonium, aromatic diazonium, aromatic ammonium, or (2,4-cyclopentadien-1-yl). ) ((1-methylethyl) benzene) -Fe cation, and the anion moiety is BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , or (BX ₄ ) ⁻ (where X is at least two fluorine atoms) Or an onium salt composed of a phenyl group substituted with a trifluoromethyl group).

Examples of the aromatic sulfonium salt include bis (4- (diphenylsulfonio) phenyl) sulfide bishexafluorophosphate, bis (4- (diphenylsulfonio) phenyl) sulfide bishexafluoroantimonate, and bis (4- ( Diphenylsulfonio) phenyl) sulfide bistetrafluoroborate, bis (4- (diphenylsulfonio) phenyl) sulfide tetrakis (pentafluorophenyl) borate, diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate, diphenyl-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 bistetrafluoroborate, 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 hexa Fluorophosphate, 4-methylphenyl-4- (1-methylethyl) Such as phenyl iodonium hexafluoroantimonate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrafluoroborate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) borate Can be mentioned.

Examples of the aromatic diazonium salt include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis (pentafluorophenyl) borate.

Examples of the aromatic ammonium salt include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2-cyanopyridinium tetrafluoroborate, and 1-benzyl. 2-cyanopyridinium tetrakis (pentafluorophenyl) borate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluorophosphate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluoroantimonate, 1- (naphthylmethyl) Examples include 2-cyanopyridinium tetrafluoroborate and 1- (naphthylmethyl) -2-cyanopyridinium tetrakis (pentafluorophenyl) borate.

Examples of the (2,4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -Fe salt include (2,4-cyclopentadien-1-yl) ((1-methylethyl) benzene. ) -Fe (II) hexafluorophosphate, (2,4-cyclopentadiene-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 Fluorophenyl) borate and the like.

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

Examples of commercially available photocationic polymerization initiators include, for example, DTS-200 (manufactured by Midori Chemical Co., Ltd.), UVI6990, UVI6974 (all manufactured by Union Carbide), SP-150, SP-170 (all ADEKA), FC-508, FC-512 (all from 3M), IRGACURE 261, IRGACURE 290 (all from BASF Japan), PI 2074 (from Rhodia), and the like.

Examples of the thermal cationic polymerization initiator include BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , or (BX ₄ ) ⁻ (wherein X is substituted with at least two fluorine or trifluoromethyl groups. And a sulfonium salt, a phosphonium salt, a quaternary ammonium salt, a diazonium salt, an iodonium salt, and the like. Of these, sulfonium salts are preferred.

Examples of the sulfonium salts include triphenylsulfonium boron tetrafluoride, triphenylsulfonium hexafluoride antimony, triphenylsulfonium hexafluoride arsenic, tri (4-methoxyphenyl) sulfonium hexafluoride arsenic, diphenyl (4-phenylthiophenyl). ) Sulfonium arsenic hexafluoride and the like.
Examples of the phosphonium salt include ethyltriphenylphosphonium antimony hexafluoride and tetrabutylphosphonium antimony hexafluoride.
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 hexafluorohexafluorophosphate, dimethylphenyl (4-methylbenzyl) ammonium hexafluoroantimonate, dimethylphenyl (4-methylbenzyl) ammonium hexafluorotetrakis (pentafluorophenyl) ) Borate, methylphenyldibenzylammonium, methylphenyldibenzylammonium hexaf Oroantimonate hexafluorophosphate, methylphenyldibenzylammonium trakis (pentafluorophenyl) borate, phenyltribenzylammonium tetrakis (pentafluorophenyl) borate, dimethylphenyl (3,4-dimethylbenzyl) ammonium tetrakis (pentafluorophenyl) Borate, antimony N, N-dimethyl-N-benzylanilinium hexafluoride, N, N-diethyl-N-benzylanilinium tetrafluoride, antimony N, N-dimethyl-N-benzylpyridinium hexafluoride, N , N-diethyl-N-benzylpyridinium trifluoromethanesulfonic acid and the like.

Examples of commercially available thermal cationic polymerization initiators include, for example, Adeka Opton CP-66, Adeka Opton CP-77 (both manufactured by ADEKA), and thermal cations having not only thermal activity but also photoactivity. Polymerization initiators, Sun-Aid SI-60, Sun-Aid SI-80, Sun-Aid SI-100, Sun-Aid SI-110, Sun-Aid SI-180 (all manufactured by Sanshin Chemical Industry Co., Ltd.), CXC-1612, CXC-1738, CXC -1821 (both manufactured by King Industries) and the like.

The content of the cationic polymerization initiator is preferably 0.1 parts by weight and preferably 10 parts by weight with respect to 100 parts by weight of the cationic curable resin. If the content of the cationic polymerization initiator is less than 0.1 parts by weight, the cationic polymerization may not proceed sufficiently, or the curing reaction may become too slow. When the content of the cationic polymerization initiator exceeds 10 parts by weight, the curing reaction of the resulting organic EL display element sealant becomes too fast, resulting in a decrease in workability or the resulting organic EL display element seal. The cured product of the stopper may become uneven. The minimum with more preferable content of the said cationic polymerization initiator 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 sensitizer. The sensitizer has a role of further improving the polymerization initiation efficiency of the cationic polymerization initiator and further promoting the curing reaction of the sealant for organic EL display elements of the present invention.

Examples of the sensitizer include thioxanthone compounds such as 2,4-diethylthioxanthone, 2,2-dimethoxy-1,2-diphenylethane-1-one, benzophenone, 2,4-dichlorobenzophenone, o- Examples include methyl benzoylbenzoate, 4,4′-bis (dimethylamino) benzophenone, 4-benzoyl-4′methyldiphenyl sulfide.

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

The sealing agent for organic EL display elements of the present invention preferably contains a filler for the purpose of improving the moisture resistance of the cured product. In particular, when the compound represented by the above formula (1) having a low viscosity is used as the cationic curable resin according to the present invention, a large amount of filler can be blended without deteriorating the coating property.

Examples of the filler include talc, asbestos, silica, mica, diatomaceous earth, smectite, bentonite, calcium carbonate, magnesium carbonate, alumina, montmorillonite, zinc oxide, iron oxide, magnesium oxide, tin oxide, titanium oxide, and magnesium hydroxide. Inorganic fillers such as aluminum hydroxide, silicon nitride, barium sulfate, gypsum, calcium silicate, glass beads, sericite activated clay, bentonite, aluminum nitride, polyester fine particles, polyurethane fine particles, vinyl polymer fine particles, acrylic polymer fine particles, etc. Organic fillers and the like. Of these, talc is preferred because of its excellent effect of improving moisture resistance.

The preferred lower limit of the content of the filler is 10 parts by weight and the preferred upper limit is 80 parts by weight with respect to 100 parts by weight of the cationic curable resin. If the content of the filler is less than 10 parts by weight, the effect of improving moisture resistance may not be sufficiently exhibited. When content of the said filler exceeds 80 weight part, the viscosity of the sealing agent for organic EL display elements obtained will become high too much, and applicability | paintability may deteriorate. The minimum with more preferable content of the said filler is 15 weight part, and a more preferable upper limit is 70 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, and 3-isocyanatopropyltrimethoxysilane. 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 cation curable resin. When the content of the silane coupling agent is less than 0.1 parts by weight, the effect of improving the adhesiveness of the obtained sealing agent for organic EL display elements may not be sufficiently exhibited. When content of the said silane coupling agent exceeds 10 weight part, an excess silane coupling agent may bleed out. The minimum with more preferable content of the said silane coupling agent is 0.5 weight part, and a more preferable upper limit is 5 weight part.

The sealing agent for organic EL display elements of the present invention may further contain a thermosetting agent as long as the object of the present invention is not impaired. By containing the said thermosetting agent, thermosetting property can be provided to the sealing agent for organic EL display elements of this invention.

The thermosetting agent is not particularly limited, and examples thereof include hydrazide compounds, imidazole derivatives, acid anhydrides, dicyandiamides, guanidine derivatives, modified aliphatic polyamines, addition products of various amines and epoxy resins, and the like.
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 and 2-phenyl-4,5-dihydroxymethylimidazole.
Examples of the acid anhydride include tetrahydrophthalic anhydride, ethylene glycol bis (anhydro trimellitate), and the like.
These thermosetting agents may be used alone or in combination of two or more.

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 cationic curable resin. When the content of the thermosetting agent is less than 0.5 parts by weight, sufficient thermosetting property may not be imparted to the obtained sealing agent for organic EL display elements. When the content of the thermosetting agent exceeds 30 parts by weight, the storage stability of the obtained sealant for organic EL display elements becomes insufficient, or the cured product of the obtained sealant for organic EL display elements. Moisture resistance may deteriorate. The minimum with more preferable content of the said thermosetting agent is 1 weight part, and a more preferable upper limit is 15 weight part.

The 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 surface modifier, the flatness of the coating film can be imparted to the organic EL display element sealant of the present invention.
Examples of the surface modifier include surfactants and leveling agents.

Examples of the surfactant and the leveling agent include silicon-based, acrylic-based, and fluorine-based ones.
Examples of commercially available surfactants and leveling agents include BYK-345 (manufactured by BYK Japan), BYK-340 (manufactured by BYK Japan), Surflon S-611 (AGC Seimi Chemical). Etc.).

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. A compound or an ion exchange resin may be contained.

Examples of the compound that reacts with the generated acid include substances that neutralize the acid, for example, alkali metal carbonates or bicarbonates, or alkaline earth metal carbonates or bicarbonates. 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.

Examples of the method for producing the sealing agent for organic EL display elements of the present invention include a cation curable resin using a mixer such as a homodisper, a homomixer, a universal mixer, a planetary mixer, a kneader, or a three roll. And a method of mixing a cationic polymerization initiator and an additive to be added as necessary.

The sealant for organic EL display elements of the present invention has an overall viscosity lower limit of 80 mPa · s and an upper limit of 5000 mPa · s measured using an E-type viscometer at 25 ° C. and 1 to 100 rpm. When the viscosity is less than 80 mPa · s, the obtained sealing agent for organic EL display elements is inferior in applicability and shape stability after application, composition unevenness occurs, and the cured product becomes transparent. It becomes inferior. When the said viscosity exceeds 5000 mPa * s, the sealing agent for organic EL display elements obtained will be inferior to applicability | paintability. The preferable lower limit of the viscosity is 150 mPa · s, the preferable upper limit is 3000 mPa · s, the more preferable lower limit is 200 mPa · s, and the more preferable upper limit is 1000 mPa · s.
In addition, the said viscosity can be measured with CP1 type | mold cone plate, for example using VISCOMETER TV-22 (made by Toki Sangyo Co., Ltd.) as an E-type viscosity meter.
In addition, when measuring using an E-type viscometer, when the viscosity is 1000 mPa · s or more and less than 5000 mPa · s, it is measured under the condition of 1 rpm, and when the viscosity is 500 mPa · s or more and less than 1000 mPa · s, it is 5 rpm. When the viscosity is 200 mPa · s or more and less than 500 mPa · s, the measurement is performed under the condition of 10 rpm. When the viscosity is 50 mPa · s or more and less than 200 mPa · s, the measurement is performed under the condition of 20 rpm, and the viscosity is 50 mPa · s. -When it becomes less than s, it is preferable to measure on the conditions of 100 rpm.

ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of outgas can be suppressed and the sealing agent for organic EL display elements which is excellent in applicability | paintability can be provided.

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

(Example 1)
As a cationic curable resin, 50 parts by weight of a compound represented by the above formula (4) (manufactured by Daicel, “Celoxide 8000”) and a compound represented by the above formula (5) (manufactured by Nissan Chemical Co., Ltd., “TEPIC-VL”). ") 50 parts by weight and 1 part by weight of an aromatic sulfonium salt (manufactured by Midori Kagaku Co.," DTS-200 ") as a photocationic polymerization initiator are mixed and heated to 80 ° C, and then stirred and mixed (Sinky Corporation). Manufactured, “AR-250”), and uniformly stirred and mixed at a stirring speed of 3000 rpm to prepare a sealing agent for organic EL display elements.

(Examples 2-7, Comparative Examples 1-6)
Each material described in Table 1 was stirred and mixed in the same manner as in Example 1 in accordance with the blending ratio described in Table 1 to prepare an organic EL display element sealant.

<Evaluation>
The following evaluation was performed about each sealing agent for organic EL display elements obtained in Examples 1-7 and Comparative Examples 1-6. The results are shown in Table 1.

(viscosity)
About each sealing agent for organic EL display elements obtained in Examples 1 to 7 and Comparative Examples 1 to 6, an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., “VISCOMETER TV-22” cone plate: CP1 type) was used. The viscosity under the conditions of 25 ° C. and 1 to 100 rpm was measured.

(Coating properties and coating shape stability)
Using a dispenser (manufactured by Musashi Engineering Co., Ltd., “SHOTMASTER300”), the dispensing nozzle is fixed to 400 μm, the nozzle gap is set to 30 μm, the coating pressure is fixed to 300 kPa, and obtained in Examples 1 to 7 and Comparative Examples 1 to 6 on a glass substrate. Each obtained sealing agent for organic EL display elements was apply | coated. After application, the resin was cured by irradiating with ultraviolet rays at 1500 mJ / cm ² using an ultraviolet irradiation device (“JL-4300-3S” manufactured by Oak Co.) and then heating at 100 ° C. for 15 minutes. In addition, about the sealing agent for organic EL display elements obtained in Examples 4-6 and Comparative Examples 2 and 5, it heat-hardened for 30 minutes at 100 degreeC, without performing ultraviolet irradiation. The change in weight from the application of the sealant to the occurrence of the curing reaction was confirmed using a thermogravimetric apparatus (TA-INSTRUMENTS, “TGA”).
Can be applied without fading or sagging, and when there is almost no weight loss before the curing reaction occurs, “○”, when the coating state is faint or sagging, or less than 5% before the curing reaction occurs “△” when the weight loss of the coating occurs, when the coating state is largely out of application, uneven coating occurs, or when the coating cannot be applied at all, or when the weight reduction of 5% or more occurs before the curing reaction occurs The coating property and the coating shape stability were evaluated as “X”.

(Outgas prevention)
300 mg of each organic EL display element sealant obtained in Examples 1 to 7 and Comparative Examples 1 to 6 was weighed and sealed in a vial, and then an ultraviolet irradiation device (manufactured by Oak Co., “JL-4300”). −3S ”) was irradiated with ultraviolet rays at 1500 mJ / cm ² and then heated at 100 ° C. for 15 minutes to cure the resin. Further, 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-k9” manufactured by JEOL Ltd.). In addition, about the sealing agent for organic EL display elements obtained in Examples 4-6 and Comparative Examples 2 and 5, it heat-hardened for 30 minutes at 100 degreeC, without performing ultraviolet irradiation.
As a result, the outgassing prevention property was evaluated as “◯” when the vaporized component amount was less than 20 ppm, “Δ” when it was 20 ppm or more and less than 100 ppm, and “X” when it was 100 ppm or more.

ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of outgas can be suppressed and the sealing agent for organic EL display elements which is excellent in applicability | paintability can be provided.

Claims (3)

A sealing agent for an organic EL display element containing a cationic curable resin and a cationic polymerization initiator,
The cationic curable resin has an epoxy group or an oxetanyl group and does not have an ether bond and an ester bond other than those contained in the epoxy group or the oxetanyl group, and is represented by the following formula (1). that the compounds and represented by the following formula (2) containing the compound,
Using an E-type viscometer, 25 ° C., organic EL display element overall viscosity of the organic EL display element sealing agent was measured under conditions of 1~100rpm are you characterized 80~5000mPa · s der Rukoto Sealing agent.

In formula (1), R ^{1 to} R ¹⁸ are a hydrogen atom, a halogen atom, or a hydrocarbon group that may contain an oxygen atom or a halogen atom, and may be the same or different. Also good.

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

In formula (3-1), R ²² represents a hydrogen atom or a methyl group. Formula organic EL display sealant element according to claim 1, characterized by containing a compound represented by (4) a compound represented by the formula (1).

The compound represented by the following formula (5) is contained as the compound represented by the formula (2), and the sealing agent for organic EL display elements according to claim 1 or 2 .