JP2018110056A - Organic electroluminescent element sealing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL element sealing composition which can be applied stably by ink-jet printing method, and can form a cured material excellent in moisture resistance, by curing rapidly upon light irradiation.SOLUTION: An organic EL element sealing composition to be applied by ink-jet printing method is a composition containing a cationic polymerization compound and a cationic polymerization initiator, where the viscosity is 20 mPa s or less at 25°C. The organic EL element sealing composition contains, as the cationic polymerization compound, an epoxy compound and/or vinyl ether compound by 50 wt% or more of the total amount of cationic polymerization compound, content of the cationic polymerization compound having viscosity of 100 mPa s or more at 25°C is 20 wt% or less of the total amount of cationic polymerization compound contained in the composition, and the content of the cationic polymerization compound having a boiling point of 190°C or less under normal pressure is less than 20 wt% of the total amount of cationic polymerization compound contained in the composition.SELECTED DRAWING: None

Description

  The present invention relates to an organic electroluminescent element sealing composition for application by an ink jet printing method.

  An organic electroluminescence (sometimes referred to as “organic EL” in this specification) element has a structure in which a light-emitting layer is sandwiched between a pair of counter electrodes. Electrons are injected from one electrode and the other Holes are injected from the electrode. Light emission occurs when the injected electrons and holes recombine in the light emitting layer. An organic EL device including an organic EL element is expected as a full-color flat panel display or an alternative to an LED because of high impact resistance and high visibility and a variety of emission colors.

  However, organic EL elements are more susceptible to moisture than other electronic components, and moisture that penetrates into the organic EL elements can cause electrode oxidation or organic modification, resulting in a significant decrease in light emission characteristics. Met. As a method for solving this problem, a method of sealing the periphery of an organic EL element with a moisture-proof resin is known.

  Patent Document 1 describes a composition containing an oxetane compound, an epoxy compound, and a vinyl ether compound as a curable compound, and the composition can be easily applied using an inkjet printing method, and It is described that the cured product is excellent in moisture resistance.

JP 2014-225380 A

  However, the composition described in Patent Document 1 is still insufficient in terms of moisture resistance. In addition, the fluidity of the composition is reduced during printing, and the composition tends to solidify and adhere to the nozzle opening of the inkjet head, making the injection unstable or clogging the nozzle opening and making the injection impossible. I found out that

Accordingly, an object of the present invention is to provide an organic EL device that can be stably applied by an ink jet printing method and can be cured quickly by irradiation with light to form a cured product having excellent moisture resistance. It is to provide a stopping composition.
Another object of the present invention is that it can be stably applied by an ink jet printing method, and can be quickly cured by irradiation with light to form a cured product having excellent moisture resistance and low outgassing properties. It is providing the composition for organic electroluminescent element sealing.
The other object of this invention is to provide the manufacturing method of the organic EL device using the said composition for organic EL element sealing.
Another object of the present invention is to provide an organic EL device having a configuration in which an organic EL element is sealed (or coated) with a cured product of the organic EL element sealing composition.

As a result of intensive studies to solve the above problems, the present inventor has found that an organic EL element sealing composition for application by an ink jet printing method is an oxetane compound (particularly 3-ethyl-3- (2 -It has been found that when an aliphatic oxetane compound such as ethylhexyloxymethyl) oxetane is contained in an amount exceeding 50% of the total amount of the curable compound, the moisture resistance of the resulting cured product is lowered. In addition, when a curable compound having a boiling point of less than 190 ° C. is contained, these are volatilized during printing, and the fluidity of the composition is likely to be reduced. It became clear that the nozzle became unstable and the nozzle mouth was clogged, making injection impossible.
The composition having the following configurations [1] to [4] can be stably applied by an ink jet printing method, and is cured rapidly by irradiation with light, and has excellent moisture resistance. I found out that things can be formed. The present invention has been completed based on these findings.
[1] A composition containing a cationic polymerizable compound and a cationic polymerization initiator, and having a viscosity at 25 ° C. of 20 mPa · s or less. [2] As a cationic polymerizable compound, an epoxy compound and / or a vinyl ether compound is used. [3] The content of the cationic polymerizable compound having a viscosity at 25 ° C. of 100 mPa · s or more is 50% by weight or more of the total amount of the cationic polymerizable compound contained in the composition. [4] The content of the cationically polymerizable compound having a boiling point of 190 ° C. or lower under normal pressure is less than 20% by weight of the total amount of the cationically polymerizable compound contained in the composition.

That is, the present invention is a composition containing a cationically polymerizable compound and a cationic polymerization initiator, and has a viscosity at 25 ° C. of 20 mPa · s or less,
50 wt% or more of the total amount of the cationically polymerizable compound contained in the composition is an epoxy compound and / or a vinyl ether compound,
The content of the cationic polymerizable compound having a viscosity at 25 ° C. of 100 mPa · s or more is 20% by weight or less of the total amount of the cationic polymerizable compound contained in the composition, and the content of the cationic polymerizable compound having a boiling point of 190 ° C. or less under normal pressure Provided is an organic EL device sealing composition for coating by an ink jet printing method, the amount of which is less than 20% by weight of the total amount of cationically polymerizable compounds contained in the composition.

（式中、Ｘは単結合又は連結基を示す） The present invention also provides the organic EL device sealing composition, wherein the composition of the cationically polymerizable compound is the following [1] or [2].
[1] When the content of the vinyl ether compound is less than 30% by weight of the total amount of the cationic polymerizable compound, the total content of the polyfunctional alicyclic epoxy compound represented by the following formula (a-1) and the glycidyl ether type epoxy compound Is a polyfunctional compound represented by the following formula (a-1) when the content of the vinyl ether compound is 30% by weight or more of the total amount of the cationically polymerizable compound. The content of the alicyclic epoxy compound is 5% by weight or more of the total amount of the cation polymerizable compound, and the total content of the polyfunctional alicyclic epoxy compound and the vinyl ether compound is 50% by weight or more of the total amount of the cation polymerizable compound.

(Wherein X represents a single bond or a linking group)

  In the present invention, the polyfunctional alicyclic epoxy compound represented by the formula (a-1) is a 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate, (3,4,3 ′ , 4′-diepoxy) bicyclohexyl, bis (3,4-epoxycyclohexylmethyl) ether, 1,2-epoxy-1,2-bis (3,4-epoxycyclohexane-1-yl) ethane, and 2,2 -Provided is the organic EL device sealing composition, which is at least one compound selected from the group consisting of bis (3,4-epoxycyclohexane-1-yl) propane.

（式中、Ｒ^a1はシクロヘキセンオキシド基以外の反応性官能基を示し、Ｒ^a2、Ｒ^a3は同一又は異なって、水素原子又はアルキル基を示す。Ｌ’は単結合又は連結基を示す） The present invention also provides the organic EL device sealing composition further comprising a monofunctional alicyclic epoxy compound represented by the following formula (a-1 ′) as a cationic polymerizable compound.

(In the formula, R ^a1 represents a reactive functional group other than a cyclohexene oxide group, R ^a2 and R ^a3 are the same or different and represent a hydrogen atom or an alkyl group. L ′ represents a single bond or a linking group)

  The present invention also provides the organic EL device sealing composition, wherein the vinyl ether compound contains at least a vinyl ether compound having a ring structure.

  The present invention also provides the organic EL element sealing composition, wherein the outgas amount during curing is 1000 ppm or less.

The present invention also provides the organic EL element sealing composition, wherein the cured product has a water vapor transmission rate of 200 g / m ² · day · atm or less.

  The present invention also provides a method for producing an organic EL device, wherein the organic EL element is sealed by applying the organic EL element sealing composition by an ink jet printing method.

  The present invention also provides an organic EL device having a configuration in which an organic EL element is sealed with a cured product of the organic EL element sealing composition.

Since the composition for sealing an organic EL element of the present invention has the above-described configuration, it has excellent ejection stability from the nozzle of the inkjet head, and the ejection becomes unstable by solidifying and adhering to the nozzle port of the inkjet head. Or injection failure and good injection can be stably maintained over time.
Moreover, the composition for organic EL element sealing of this invention can harden | cure rapidly by irradiating an ultraviolet-ray after application | coating, and can form the hardened | cured material excellent in moisture resistance and low outgassing property.
Therefore, the composition for sealing an organic EL element of the present invention can be suitably used for an application for sealing an organic EL element using an ink jet printing method.
And if the composition for organic EL element sealing of this invention is used, it can apply | coat stably and at high speed uniformly by the inkjet printing method, and is excellent in workability | operativity.
Furthermore, if the composition for sealing an organic EL device of the present invention is used, the organic EL device can be sealed with a cured product having excellent moisture resistance, and by preventing deterioration, the organic EL device has a high luminance and a long life. An EL device is obtained.

[Organic EL device sealing composition]
The composition for sealing an organic EL device of the present invention is a composition containing a cationic polymerizable compound and a cationic polymerization initiator,
The viscosity at 25 ° C. is 20 mPa · s or less,
50 wt% or more of the total amount of the cationically polymerizable compound contained in the composition is an epoxy compound and / or a vinyl ether compound,
The content of the cationic polymerizable compound having a viscosity at 25 ° C. of 100 mPa · s or more is 20% by weight or less of the total amount of the cationic polymerizable compound contained in the composition, and the content of the cationic polymerizable compound having a boiling point of 190 ° C. or less under normal pressure The amount is less than 20% by weight of the total amount of the cationically polymerizable compound contained in the composition.

[Cationically polymerizable compound]
The composition for sealing an organic EL device of the present invention contains an epoxy compound and / or a vinyl ether compound as a cationic polymerizable compound.

<Epoxy compound>
The epoxy compound is a compound having at least one epoxy group (oxirane ring) in the molecule, and includes an alicyclic epoxy compound, an aromatic epoxy compound, and an aliphatic epoxy compound.

(Alicyclic epoxy compound)
The alicyclic epoxy compound is a compound having one or more alicyclic rings and one or more epoxy groups in the molecule, and includes the following compounds.
(1) An epoxy group composed of two adjacent carbon atoms and oxygen atoms constituting an alicyclic ring in the molecule (in this specification, sometimes referred to as “alicyclic epoxy group”. Includes a compound having a cyclohexene oxide group), a compound having an epoxy group directly bonded to the alicyclic ring with a single bond, and a compound having an alicyclic ring and a glycidyl ether group in the molecule (so-called glycidyl group). Ether type epoxy compound)

  (1) The compound having an alicyclic epoxy group in the molecule includes a compound (1-1 ') having one alicyclic epoxy group in the molecule or a compound having two or more alicyclic epoxy groups in the molecule. (1-1) is included.

Examples of the compound (1-1) having two or more alicyclic epoxy groups in the molecule include polyfunctional alicyclic epoxy compounds represented by the following formula (a-1).

  In the above formula (a-1), X represents a single bond or a linking group (a divalent group having one or more atoms). Examples of the linking group include a divalent hydrocarbon group, an alkenylene group in which part or all of a carbon-carbon double bond is epoxidized, a carbonyl group, an ether bond, an ester bond, a carbonate group, an amide group, and Examples include a group in which a plurality of these are linked.

  As said bivalent hydrocarbon group, a C1-C18 linear or branched alkylene group, a C3-C18 bivalent alicyclic hydrocarbon group, etc. are mentioned. Examples of the linear or branched alkylene group having 1 to 18 carbon atoms include a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, and a trimethylene group. Examples of the divalent alicyclic hydrocarbon group having 3 to 18 carbon atoms include a 1,2-cyclopentylene group, a 1,3-cyclopentylene group, a cyclopentylidene group, and a 1,2-cyclohexylene group. , Cycloalkylene groups (including cycloalkylidene groups) such as 1,3-cyclohexylene group, 1,4-cyclohexylene group and cyclohexylidene group.

  Examples of the alkenylene group in the alkenylene group in which part or all of the carbon-carbon double bond is epoxidized (sometimes referred to as “epoxidized alkenylene group”) include, for example, vinylene group, propenylene group, and 1-butenylene group. , A 2-butenylene group, a butadienylene group, a pentenylene group, a hexenylene group, a heptenylene group, an octenylene group, etc., and a linear or branched alkenylene group having 2 to 8 carbon atoms. In particular, the epoxidized alkenylene group is preferably an alkenylene group in which all of the carbon-carbon double bonds are epoxidized, more preferably 2 to 4 carbon atoms in which all of the carbon-carbon double bonds are epoxidized. Alkenylene group.

The two cyclohexane rings in the formula (a-1) each contain a substituent [for example, a halogen atom (a fluorine atom, a chlorine atom, etc.), an oxygen atom or a halogen atom in addition to the epoxy group shown in the formula An optionally substituted hydrocarbon group (eg, a C _1-4 alkyl group, a C _1-4 haloalkyl group, a C _1-4 alkoxy-C _1-4 alkyl group, etc.), and an optionally substituted alkoxy group One or two or more (for example, a C _1-4 alkoxy group, a halogenated C _1-4 alkoxy group, etc.) may be contained.

Typical examples of the polyfunctional alicyclic epoxy compound represented by the formula (a-1) include (3,4,3 ′, 4′-diepoxy) bicyclohexyl and bis (3,4-epoxycyclohexylmethyl). ) Ether, 1,2-epoxy-1,2-bis (3,4-epoxycyclohexane-1-yl) ethane, 2,2-bis (3,4-epoxycyclohexane-1-yl) propane, 1,2 -Bis (3,4-epoxycyclohexane-1-yl) ethane, compounds represented by the following formulas (a-1-1) to (a-1-10), and the like. Note that L in the following formula (a-1-5) is an alkylene group having 1 to 8 carbon atoms, and in particular, a straight chain having 1 to 3 carbon atoms such as a methylene group, an ethylene group, a propylene group, and an isopropylene group. A chain or branched alkylene group is preferred. N ^{1 to} n ⁸ in the following formulas (a-1-5), (a-1-7), (a-1-9), and (a-1-10) are integers of 1 to 30, respectively. Indicates.

Examples of the compound (1-1 ′) having one alicyclic epoxy group in the molecule include a monofunctional alicyclic epoxy compound represented by the following formula (a-1 ′).

In the formula (a-1 ′), R ^a1 represents a reactive functional group (polymerizable functional group) other than a cyclohexene oxide group, such as a vinyl ether group, a (meth) acryloyloxy group, an epoxy group, a glycidyl group, or an oxetanyl group. Etc.

In formula (a-1 ′), R ^a2 and R ^a3 are the same or different and each represents a hydrogen atom or an alkyl group (for example, an alkyl group having 1 to 5 carbon atoms such as a methyl group or an ethyl group).

  In the formula (a-1 ′), L ′ represents a single bond or a linking group. Examples of the linking group include a divalent hydrocarbon group, a carbonyl group (—CO—), an ether bond (—O—), a thioether bond (—S—), an ester bond (—COO—), an amide bond ( -CONH-), carbonate bond (-OCOO-) and the like.

  Examples of the divalent hydrocarbon group include linear or branched alkylene groups having 1 to 5 carbon atoms such as a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, and a trimethylene group. It is done.

  As the compound (1-1 ′) having one alicyclic epoxy group in the molecule, among others, 1,2: 8,9-diepoxylimonene and / or 3,4-epoxycyclohexylmethyl (meth) acrylate Is preferred.

Examples of the compound (2) in which the epoxy group is directly bonded to the alicyclic ring with a single bond include compounds represented by the following formula (a-2).

In formula (a-2), R ^a4 is a group (p-valent organic group) obtained by removing p hydroxyl groups (—OH) from the structural formula of p-valent alcohol, and p and n ⁹ are natural numbers, respectively. Represent. Examples of the p-valent alcohol [R ^a4 (OH) _p ] include polyhydric alcohols (such as polyhydric alcohols having 1 to 15 carbon atoms) such as 2,2-bis (hydroxymethyl) -1-butanol. p is preferably 1 to 6, and n ⁹ is preferably 1 to 30. When p is 2 or more, n ⁹ in each [] (inside square brackets) may be the same or different. As the compound represented by the above formula (a-2), specifically, 1,2-epoxy-4- (2-oxiranyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol [For example, trade name “EHPE3150” (manufactured by Daicel Corporation), etc.] and the like.

  Examples of the compound (3) having an alicyclic ring and a glycidyl ether group in the molecule include glycidyl ethers of alicyclic alcohols (particularly alicyclic polyhydric alcohols). More specifically, for example, a compound obtained by hydrogenating a bisphenol A type epoxy compound (hydrogenated bisphenol A type epoxy compound), a compound obtained by hydrogenating a bisphenol F type epoxy compound (hydrogenated bisphenol F type epoxy compound); Epoxy compound; Hydrogenated phenol novolac type epoxy compound; Hydrogenated cresol novolac type epoxy compound; Hydrogenated cresol novolac type epoxy compound of bisphenol A; Hydrogenated naphthalene type epoxy compound; Compound obtained by hydrogenating epoxy compound obtained from trisphenolmethane Etc.

(Aromatic epoxy compounds)
Examples of the aromatic epoxy compound include, for example, an epibis type glycidyl ether type epoxy compound obtained by a condensation reaction of phenyl glycidyl ether, bisphenol [for example, bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, etc.] and an epihalohydrin. A high molecular weight epibis type glycidyl ether type epoxy compound obtained by further reacting these epibis type glycidyl ether type epoxy compounds with the above bisphenols; phenols [eg, phenol, cresol, xylenol, resorcin, catechol, Bisphenol A, bisphenol F, bisphenol S, etc.] and aldehyde [eg, formaldehyde, acetaldehyde, benzaldehyde, A novolak alkyl type glycidyl ether type epoxy compound obtained by condensation reaction of polyhydric alcohols obtained by condensation reaction with droxybenzaldehyde, salicylaldehyde, etc.] with epihalohydrin; two at the 9-position of the fluorene ring Examples thereof include an epoxy compound in which a phenol skeleton is bonded and a glycidyl group is bonded to an oxygen atom obtained by removing a hydrogen atom from the hydroxy group of these phenol skeletons directly or via an alkyleneoxy group.

(Aliphatic epoxy compounds)
Examples of the aliphatic epoxy compound include a glycidyl ether of an alcohol having no q-valent cyclic structure (q is a natural number); a monovalent or polyvalent carboxylic acid [for example, acetic acid, propionic acid, butyric acid, stearic acid, Adipic acid, sebacic acid, maleic acid, itaconic acid, etc.] glycidyl ester; epoxidized oils and fats having double bonds such as epoxidized linseed oil, epoxidized soybean oil, epoxidized castor oil; polyolefins such as epoxidized polybutadiene (poly Epoxidized product of alkadiene). Examples of the alcohol having no q-valent cyclic structure include monohydric alcohols such as methanol, ethanol, 1-propyl alcohol, isopropyl alcohol, 1-butanol; ethylene glycol, 1,2-propanediol, 1 , 3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and other dihydric alcohols; Examples include trihydric or higher polyhydric alcohols such as glycerin, diglycerin, erythritol, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, sorbitol, etc. . The q-valent alcohol may be polyether polyol, polyester polyol, polycarbonate polyol, polyolefin polyol, or the like.

  As an epoxy compound, a compound having one or two alicyclic epoxy groups (especially cyclohexene oxide groups) in the molecule (= alicyclic epoxy compound) has a low viscosity and a high boiling point, and is further fast-curing. In particular, the compound (1-1) having two or more alicyclic epoxy groups in the molecule (particularly represented by the above formula (a-1)) is preferable. It is preferable that the polyfunctional alicyclic epoxy compound) is at least included in the curability. In addition, the compound (1-1 ′) having one alicyclic epoxy group in the molecule (in particular, the monofunctional alicyclic epoxy compound represented by the above formula (a-1 ′)) is an alicyclic epoxy in the molecule. Since it has a lower viscosity and excellent fluidity than the compound (1-1) having two or more groups, it can be contained together with the compound (1-1) having two or more alicyclic epoxy groups in the molecule. The viscosity of the composition for encapsulating an organic EL device of the present invention can be set to 20 mPa · s or less, which is preferable in that it can exhibit particularly excellent effects on ink jetting properties and ejection stability.

<Vinyl ether compound>
A vinyl ether compound is a compound having one or more vinyl ether groups in the molecule. Examples of such a compound include a compound represented by the following formula (b).
R ^b — (O—CH═CH ₂ ) _n (b)
(In the formula, R ^b represents an n-valent hydrocarbon group, an n-valent heterocyclic group, or a group in which two or more of these are bonded via a single bond or a linking group. N represents an integer of 1 or more. Show)

The n-valent hydrocarbon group for R ^b includes an n-valent aliphatic hydrocarbon group, an n-valent alicyclic hydrocarbon group, and an n-valent aromatic hydrocarbon group.

  Examples of the monovalent aliphatic hydrocarbon group among the n-valent aliphatic hydrocarbon groups include, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, s-butyl group, and t-butyl group. , Alkyl groups having about 1 to 20 carbon atoms (preferably 1 to 10, particularly preferably 1 to 3) such as pentyl group, hexyl group, decyl group, dodecyl group; vinyl group, allyl group, methallyl group, 1-propenyl Group, isopropenyl group, 1-butenyl group, 2-butenyl group, 3-butenyl group, 1-pentenyl group, 2-pentenyl group, 3-pentenyl group, 4-pentenyl group, 5-hexenyl group, etc. About 20 to 20 (preferably 2 to 10, particularly preferably 2 to 3) alkenyl group; about 2 to 20 carbon atoms (preferably 2 to 10 and particularly preferably 2 to 3) such as ethynyl group and propynyl group It can be mentioned alkynyl group, and the like.

Among the n-valent alicyclic hydrocarbon groups, examples of the monovalent alicyclic hydrocarbon group include 3 to 20 members (preferably 3 to cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, and cyclooctyl group). A cycloalkyl group having about 15 members, particularly preferably 5 to 8 members; a cyclohexane having about 3 to 20 members (preferably 3 to 15 members, particularly preferably 5 to 8 members) such as a cyclopentenyl group and a cyclohexenyl group. Alkenyl group; bicycloheptanyl group, bicycloheptenyl group, perhydronaphthalen-1-yl group, norbornyl group, adamantyl group, tetracyclo [4.4.0.1 ^2,5 . And a crosslinked cyclic hydrocarbon group such as a ^1,7,10 ] dodecan-3-yl group.

  Among the n-valent aromatic hydrocarbon groups, examples of the monovalent aromatic hydrocarbon group include aryl groups having about 6 to 14 (preferably 6 to 10) carbon atoms such as a phenyl group and a naphthyl group.

  Examples of the n-valent hydrocarbon group include groups obtained by removing (n-1) hydrogen atoms from the structural formula of the monovalent hydrocarbon group exemplified above.

Examples of the heterocyclic ring constituting the n-valent heterocyclic group include, for example, a heterocyclic ring containing an oxygen atom as a hetero atom (for example, a 4-membered ring such as an oxetane ring; a furan ring, a tetrahydrofuran ring, an oxazole ring, an isoxazole ring, 5-membered ring such as γ-butyrolactone ring; 6-membered ring such as 4-oxo-4H-pyran ring, tetrahydropyran ring, morpholine ring; benzofuran ring, isobenzofuran ring, 4-oxo-4H-chromene ring, chroman ring, Condensed ring such as isochroman ring; 3-oxatricyclo [4.3.1.1 ^4,8 ] undecan-2-one ring, 3-oxatricyclo [4.2.1.0 ^4,8 ] nonane- A bridged ring such as a 2-one ring), a heterocyclic ring containing a sulfur atom as a hetero atom (for example, a 5-membered ring such as a thiophene ring, a thiazole ring, an isothiazole ring, a thiadiazole ring; 6-membered ring such as -4H-thiopyran ring; condensed ring such as benzothiophene ring), heterocycle containing nitrogen atom as a hetero atom (for example, pyrrole ring, pyrrolidine ring, pyrazole ring, imidazole ring, triazole ring, etc.) 6-membered ring such as pyridine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperidine ring, piperazine ring; condensed ring such as indole ring, indoline ring, quinoline ring, acridine ring, naphthyridine ring, quinazoline ring, purine ring Etc.). The n-valent heterocyclic group is a group obtained by removing n hydrogen atoms from the above structural formula of the heterocyclic ring.

  Examples of the linking group include a carbonyl group, an ether bond, and an ester bond.

The vinyl ether compound preferably contains at least a vinyl ether compound having a ring structure in that it has a low viscosity and a high boiling point. In particular, R ^b in the above formula (b) is an n-valent alicyclic group. A vinyl ether compound which is a hydrocarbon group, an n-valent aromatic hydrocarbon group, or an n-valent heterocyclic group is preferred, and in particular, a vinyl ether compound having an alicyclic structure, a vinyl ether compound having an aromatic ring structure, and a cyclic ether structure [In particular, a vinyl ether compound having an aromatic ring structure (for example, a monofunctional vinyl ether compound having an aromatic ring structure) such as (2-phenylphenoxy) ethyl vinyl ether] has a low viscosity, a high boiling point, and a high speed. It is preferable in that it can exhibit a curability and can form a cured product having excellent moisture resistance.

  Examples of the vinyl ether compound having an alicyclic structure include cyclohexane dimethanol divinyl ether, hydrogenated bisphenol F type divinyl ether, hydrogenated biphenyl divinyl ether, hydrogenated bisphenol A type divinyl ether, tricyclodecane dimethanol divinyl ether, and the like. Can be mentioned.

  Examples of the vinyl ether compound having an aromatic ring structure include (2-phenylphenoxy) ethyl vinyl ether, bisphenol F bis (vinyloxyethyl ether), bisphenol F type divinyl ether, biphenyl divinyl ether, bisphenol A type divinyl ether, and the like. It is done.

  Examples of the vinyl ether compound having a cyclic ether structure include isosorbide divinyl ether, oxetane divinyl ether, oxanorbornene divinyl ether, and the like.

  The composition for sealing an organic EL device of the present invention includes a vinyl ether compound having a structure (particularly, a polyethylene oxide chain) in which an aliphatic hydrocarbon group is bonded as a linking group via an ether bond together with a vinyl ether compound having a ring structure. For example, diethylene glycol divinyl ether, triethylene glycol divinyl ether, etc.) can also be contained. Since the said compound has a low viscosity and is excellent in fluidity | liquidity, the injection property of the composition for organic EL element sealing of this invention can be improved by containing this.

<Other cationic polymerizable compounds>
The composition for sealing an organic EL device of the present invention may contain other cationic polymerizable compounds in addition to the epoxy compound and the vinyl ether compound as the cationic polymerizable compound, such as an oxetane compound (epoxy group or vinyl ether). 1 type or 2 types or more may be contained except the compound which has group.

As an oxetane compound, the compound represented by a following formula (c) is mentioned, for example.

In formula (c), R ^c1 represents a monovalent organic group, and R ^c2 represents a hydrogen atom or an ethyl group. m represents an integer of 1 or more.

The monovalent organic group in R ^c1 includes a monovalent hydrocarbon group, a monovalent heterocyclic group, a substituted oxycarbonyl group (alkoxycarbonyl group, aryloxycarbonyl group, aralkyloxycarbonyl group, cycloalkyloxycarbonyl group). Etc.), substituted carbamoyl groups (N-alkylcarbamoyl groups, N-arylcarbamoyl groups, etc.), acyl groups (aliphatic acyl groups such as acetyl groups; aromatic acyl groups such as benzoyl groups), and two or more of these A monovalent group bonded through a single bond or a linking group is included.

Examples of the monovalent hydrocarbon group and monovalent heterocyclic group include the same examples as in R ^b in the above formula (b).

  Examples of the linking group include a carbonyl group (—CO—), an ether bond (—O—), a thioether bond (—S—), an ester bond (—COO—), an amide bond (—CONH—), and a carbonate bond. (-OCOO-), a silyl bond (-Si-), and a group in which a plurality of these are linked.

  Said m shows an integer greater than or equal to 1, for example 1-20, Preferably it is 1.

Examples of the oxetane compound include 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl-3- (methoxymethyl) oxetane, 3-ethyl-3- (butoxymethyl) oxetane, 3-ethyl- A compound in which R ^c1 in formula (c) such as 3- (hexyloxymethyl) oxetane is an aliphatic hydrocarbon group (=
An aliphatic oxetane compound); a compound in which R ^c1 in formula (c) is an alicyclic hydrocarbon group (= alicyclic oxetane compound) such as 3-ethyl-3- (cyclohexyloxymethyl) oxetane; bis {[ 1-ethyl (3-oxetanyl)] methyl} ether and the like, wherein R ^c1 in formula (c) is a heterocyclic group (= heterocyclic oxetane compound); 3-ethyl-3-[(phenoxy) methyl ] Compounds such as oxetane, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, wherein R ^c1 in the formula (c) is an aromatic hydrocarbon group (= aromatic oxetane compound), etc. Can be mentioned.

  In the present invention, when an oxetane compound is used, it is preferable to use an aromatic oxetane compound from the viewpoint of suppressing a decrease in moisture resistance. On the other hand, since an aliphatic oxetane compound causes a decrease in moisture resistance, it is not preferable to use a large amount thereof.

[Cationic polymerization initiator]
The composition for sealing an organic EL device of the present invention contains one or more cationic polymerization initiators together with the cationic polymerizable compound.

  As the cationic polymerization initiator, a photocationic polymerization initiator is particularly preferable. The cationic photopolymerization initiator is a compound that generates a cationic species by irradiation of light (for example, ultraviolet rays) to initiate the curing reaction of the cationic polymerizable compound, and is a cationic part that absorbs light and an anion that is a source of acid generation. Consists of parts.

  Examples of the cationic photopolymerization initiator include diazonium salt compounds, iodonium salt compounds, sulfonium salt compounds, phosphonium salt compounds, selenium salt compounds, oxonium salt compounds, ammonium salt compounds, bromine salt compounds, and the like. Can be mentioned.

  In the present invention, it is particularly preferable to use a sulfonium salt compound in that a cured product having excellent curability can be formed. Examples of the cation moiety of the sulfonium salt compound include (4-hydroxyphenyl) methylbenzylsulfonium ion, triphenylsulfonium ion, diphenyl [4- (phenylthio) phenyl] sulfonium ion, and 4- (4-biphenylylthio) phenyl. Examples thereof include arylsulfonium ions (particularly, triarylsulfonium ions) such as -4-biphenylylphenylsulfonium ion and tri-p-tolylsulfonium ion.

As an anion part of the photocationic polymerization initiator, for example, [(Y) _s B (Phf) _4-s ] ⁻ (wherein Y represents a phenyl group or a biphenylyl group. Phf represents at least one hydrogen atom, A phenyl group substituted with at least one selected from a perfluoroalkyl group, a perfluoroalkoxy group, and a halogen atom (s is an integer of 0 to 3), BF ₄ ⁻ , [(Rf) _t PF _6-t ] ^- (Rf: an alkyl group in which 80% or more of hydrogen atoms are substituted with fluorine atoms, t: an integer of 0 to 5), AsF ₆ ⁻ , SbF ₆ ⁻ , SbF ₅ OH ^{− and the} like. it can. In the present invention, among them, the cationic photopolymerization initiator having an anion portion of SbF ₆ ⁻ or [(Y) _s B (Phf) _4−s ] ⁻ has high activity as an initiator and has high curability. It is preferable at the point which can obtain the hardened | cured material excellent in heat resistance.

  Examples of the cationic photopolymerization initiator include (4-hydroxyphenyl) methylbenzylsulfonium tetrakis (pentafluorophenyl) borate, 4- (4-biphenylylthio) phenyl-4-biphenylylphenylsulfonium tetrakis (pentafluorophenyl). Borate, 4- (phenylthio) phenyldiphenylsulfonium phenyltris (pentafluorophenyl) borate, [4- (4-biphenylylthio) phenyl] -4-biphenylylphenylsulfonium phenyltris (pentafluorophenyl) borate, diphenyl [4 -(Phenylthio) phenylsulfonium] hexafluoroantimonate, diphenyl [4- (phenylthio) phenyl] sulfonium tris (pentafluoroethyl) triflu Lophosphate, diphenyl [4- (phenylthio) phenyl] sulfonium tetrakis (pentafluorophenyl) borate, diphenyl [4- (phenylthio) phenyl] sulfonium hexafluorophosphate, 4- (4-biphenylylthio) phenyl-4-biphenylyl Phenylsulfonium tris (pentafluoroethyl) trifluorophosphate, bis [4- (diphenylsulfonio) phenyl] sulfide phenyltris (pentafluorophenyl) borate, [4- (2-thioxanthonylthio) phenyl] phenyl-2- Thioxanthonylsulfonium phenyltris (pentafluorophenyl) borate, trade names “Syracure UVI-6970”, “Syracure UVI-6974”, “Syracure U “I-6990”, “Syracure UVI-950” (manufactured by Union Carbide, USA), “Irgacure 250”, “Irgacure 261”, “Irgacure 264” (above, manufactured by BASF), “CG-24-61” (Ciba Geigy) ), “Optomer SP-150”, “Optomer SP-151”, “Optomer SP-170”, “Optomer SP-171” (manufactured by ADEKA Corporation), “DAICAT II” (manufactured by Daicel Corporation) ), “UVAC1590”, “UVAC1591” (manufactured by Daicel Cytec Co., Ltd.), “CI-2064”, “CI2639”, “CI-2624”, “CI-2481”, “CI-2734” , "CI-2855", "CI-2823", "CI-2758", "CIT- "682" (manufactured by Nippon Soda Co., Ltd.), "PI-2074" (manufactured by Rhodia, tetrakis (pentafluorophenyl) borate toluylcumyl iodonium salt), "FFC509" (manufactured by 3M), "BBI-102" ”,“ BBI-101 ”,“ BBI-103 ”,“ MPI-103 ”,“ TPS-103 ”,“ MDS-103 ”,“ DTS-103 ”,“ NAT-103 ”,“ NDS-103 ”( As described above, Midori Chemical Co., Ltd.), "CD-1010", "CD-1011", "CD-1012" (above, manufactured by Sartomer, USA), "CPI-100P", "CPI-101A" (above Commercial products such as San Apro Co., Ltd.) can be used.

[Organic EL device sealing composition]
The composition for sealing an organic EL device of the present invention has a viscosity at 25 ° C. of 20 mPa · s or less (for example, 10 to 20 mPa · s), preferably 15 mPa · s or less. Since the viscosity is in the above range, the composition for sealing an organic EL device of the present invention is excellent in inkjet ejection properties and can be accurately ejected to a desired location. On the other hand, if the viscosity exceeds the above range, the composition for sealing an organic EL device of the present invention is likely to solidify and adhere to the nozzle opening of the inkjet head, and the injection becomes unstable, which is not preferable.

  The composition for sealing an organic EL device of the present invention contains the above-described epoxy compound and / or vinyl ether compound as a cationic polymerizable compound. The said compound can be contained individually by 1 type or in combination of 2 or more types.

  The total content of the epoxy compound and the vinyl ether compound is 50% by weight or more (for example, 50 to 100% by weight), preferably 60% by weight or more of the total amount of the cationic polymerizable compound contained in the composition for sealing an organic EL device of the present invention. Particularly preferably, it is 70% by weight or more, most preferably 80% by weight or more, and particularly preferably 90% by weight or more.

  In the composition for sealing an organic EL device of the present invention, the content of the cationic polymerizable compound having a viscosity at 25 ° C. of 30 mPa · s or more is, for example, 30 to 60 of the total amount of the cationic polymerizable compound contained in the composition. % By weight, preferably 30-55% by weight.

  In the composition for sealing an organic EL element of the present invention, the content of the cationic polymerizable compound having a viscosity at 25 ° C. of 100 mPa · s or more is 20% by weight or less of the total amount of the cationic polymerizable compound contained in the composition ( For example, 0 to 20% by weight). Therefore, it has a low viscosity and excellent ink jet ejection properties.

  In the composition for sealing an organic EL element of the present invention, the content of the cationic polymerizable compound having a viscosity at 25 ° C. of 2000 mPa · s or more is 15% by weight or less (for example, 0 to 15% by weight). Is preferable in that the ink jetting property can be further improved, and particularly preferably 10% by weight or less.

  In the composition for sealing an organic EL device of the present invention, the content of the cationic polymerizable compound having a boiling point of 190 ° C. or less under normal pressure is less than 20% by weight of the total amount of the cationic polymerizable compound contained in the composition. (For example, 0 wt% or more and less than 20 wt%), preferably 15 wt% or less, particularly preferably 10 wt% or less, most preferably 5 wt% or less, and particularly preferably 1 wt% or less. Therefore, it can prevent that the composition for organic electroluminescent element sealing of this invention solidifies and adheres to the nozzle opening of an inkjet head, and can maintain favorable injection | emission.

  Furthermore, the composition for sealing an organic EL device of the present invention has a content of a cationically polymerizable compound having a viscosity at 25 ° C. of less than 3 mPa · s and a boiling point of 190 ° C. or less under normal pressure. It is less than 10% by weight (preferably 5% by weight or less, particularly preferably 3% by weight or less) of the total amount of the cationically polymerizable compound contained in the composition for sealing an organic EL device of the present invention at the nozzle opening of the inkjet head. Is preferable in that it can be prevented from solidifying and adhering and good injection can be maintained.

  Furthermore, in the composition for sealing an organic EL device of the present invention, the content of the cationic polymerizable compound having a boiling point of 160 ° C. or lower under normal pressure is, for example, 20% of the total amount of the cationic polymerizable compound contained in the composition. Less than wt% (for example, 0 wt% or more and less than 20 wt%), more preferably 15 wt% or less, further preferably 10 wt% or less, particularly preferably 5 wt% or less, most preferably 3 wt% or less, particularly preferably Is preferably 1% by weight or less from the viewpoint of further improving the injection stability by inkjet.

The cationically polymerizable compound contained in the composition for encapsulating an organic EL device of the present invention has the following composition [1] or [2] to improve the ink jetting property and the injection stability. It is preferable in that
[1] When the content of the vinyl ether compound is less than 30% by weight of the total amount of the cationic polymerizable compound, the total content of the polyfunctional alicyclic epoxy compound represented by the formula (a-1) and the glycidyl ether type epoxy compound is When the content of the vinyl ether compound is 50% by weight or more of the total amount of the cationic polymerizable compound and 30% by weight or more of the total amount of the cationic polymerizable compound, the polyfunctional alicyclic group represented by the formula (a-1) The content of the epoxy compound is 5% by weight or more of the total amount of the cationic polymerizable compound, and the total content of the polyfunctional alicyclic epoxy compound and the vinyl ether compound is 50% by weight or more of the total amount of the cationic polymerizable compound.

  In the case of [1], the content of the vinyl ether compound is less than 30% by weight (for example, 0% by weight or more and less than 30% by weight), preferably 20% by weight or less, particularly preferably 10% by weight based on the total amount of the cationic polymerizable compound. % Or less, most preferably 5% by weight or less.

  In the case of [1], the content of the polyfunctional alicyclic epoxy compound represented by the formula (a-1) is, for example, 10% by weight or more (for example, 10 to 70% by weight) of the total amount of the cationic polymerizable compound, preferably Is 20 to 60% by weight, particularly preferably 30 to 55% by weight, most preferably 35 to 55% by weight.

  In the case of [1], the content of the glycidyl ether type epoxy compound is, for example, 5% by weight or more (for example, 5 to 80% by weight), preferably 10 to 50% by weight, particularly preferably 15% of the total amount of the cationic polymerizable compound. -30% by weight, most preferably 15-25% by weight.

  In the case of [1], the total content of the polyfunctional alicyclic epoxy compound represented by the formula (a-1) and the glycidyl ether type epoxy compound is 50% by weight or more of the total amount of the cationic polymerizable compound, and more preferably. Is 55% by weight or more, particularly preferably 60% by weight or more, and most preferably 65% by weight or more. The upper limit is, for example, 95% by weight, preferably 90% by weight, particularly preferably 85% by weight, most preferably 80% by weight, particularly preferably 75% by weight.

  In the case of [1], the ratio of the polyfunctional alicyclic epoxy compound represented by formula (a-1) to the glycidyl ether type epoxy compound (the former / the latter; the weight ratio) is, for example, 50/50 to 90 / 10, preferably 60/40 to 85/15, particularly preferably 60/40 to 80/20, most preferably 60/40 to 75/25, particularly preferably 60/40 to 70/30.

  In the case of [1], the epoxy compound may contain a monofunctional alicyclic epoxy compound represented by the formula (a-1 ′) together with the polyfunctional alicyclic epoxy compound represented by the formula (a-1). In addition, it is preferable in terms of being able to improve inkjet ejection properties by lowering the viscosity, and the total content of the polyfunctional alicyclic epoxy compound and the monofunctional alicyclic epoxy compound is, for example, 50% by weight or more of the total amount of the cationic polymerizable compound, Preferably it is 55 weight% or more, Especially preferably, it is 60 weight% or more, Most preferably, it is 65 weight% or more. The upper limit is, for example, 95% by weight, preferably 90% by weight, and particularly preferably 85% by weight.

  In the case of [1], the ratio of the content of the polyfunctional alicyclic epoxy compound represented by the formula (a-1) and the monofunctional alicyclic epoxy compound represented by the formula (a-1 ′) [the polyfunctional The alicyclic epoxy compound / the monofunctional alicyclic epoxy compound; weight ratio] is, for example, 50/50 to 90/10, preferably 51/49 to 85/15, particularly preferably 52/48 to 80/20, and most preferably. Is 55/45 to 70/30, particularly preferably 55/45 to 65/35.

  In the case of [1], the content of the monofunctional alicyclic epoxy compound represented by the formula (a-1 ′) is, for example, 5 to 50% by weight, preferably 10 to 45% by weight, based on the total amount of the cationic polymerizable compound. More preferably, it is 15 to 45% by weight, particularly preferably 20 to 45% by weight, and most preferably 25 to 40% by weight.

  In the case of [2], the total content of the polyfunctional alicyclic epoxy compound represented by the formula (a-1) and the vinyl ether compound is 50% by weight or more of the total amount of the cationic polymerizable compound, preferably 55% by weight. Above, particularly preferably 60% by weight or more, most preferably 65% by weight or more. The upper limit is, for example, 100% by weight, preferably 95% by weight, particularly preferably 90% by weight, and most preferably 85% by weight.

  In the case of [2], the content of the vinyl ether compound is 30% by weight or more (for example, 30 to 100% by weight), preferably 30 to 90% by weight, particularly preferably 30 to 70% by weight, based on the total amount of the cationic polymerizable compound. Most preferably, it is 40 to 60% by weight.

  In the case of [2], the content of the polyfunctional alicyclic epoxy compound represented by the formula (a-1) is, for example, 0 to 40% by weight, preferably 5 to 35% by weight, based on the total amount of the cationic polymerizable compound. Particularly preferred is 10 to 35% by weight.

  In the case of [2], the ratio of the polyfunctional alicyclic epoxy compound represented by the formula (a-1) and the vinyl ether compound (the former / the latter; the weight ratio) is, for example, 0/100 to 50 / 50, preferably 10/90 to 45/55, particularly preferably 10/90 to 40/60.

  In the case of [2], the monofunctional alicyclic epoxy compound represented by the formula (a-1 ′) is contained together with the polyfunctional alicyclic epoxy compound represented by the formula (a-1) as the epoxy compound. Is preferable in terms of being able to improve inkjet ejection properties by lowering the viscosity, and the total content of the polyfunctional alicyclic epoxy compound and the monofunctional alicyclic epoxy compound is, for example, 20% by weight or more of the total amount of the cationic polymerizable compound, It is preferably 25% by weight or more, particularly preferably 30% by weight or more, and most preferably 40% by weight or more. The upper limit is, for example, 75% by weight, preferably 70% by weight, particularly preferably 65% by weight.

  In the case of [2], the ratio of the content of the polyfunctional alicyclic epoxy compound represented by the formula (a-1) and the monofunctional alicyclic epoxy compound represented by the formula (a-1 ′) [the above Polyfunctional alicyclic epoxy compound / monofunctional alicyclic epoxy compound; weight ratio] is, for example, 10/90 to 70/30, preferably 20/80 to 60/40, and particularly preferably 30/70 to 55/45. is there.

  In the case of [2], the content of the monofunctional alicyclic epoxy compound represented by the formula (a-1 ′) is, for example, 5 to 50% by weight, preferably 10 to 45% by weight, based on the total amount of the cationic polymerizable compound. It is preferably 15 to 45% by weight, particularly preferably 20 to 45% by weight, and most preferably 25 to 40% by weight.

  The content of the oxetane compound (particularly, the aliphatic oxetane compound) is 50% by weight or less, preferably 45% by weight or less, particularly 45% by weight or less, based on the total amount of the cationically polymerizable compound contained in the organic EL device sealing composition of the present invention. It is preferably 30% by weight or less, most preferably 20% by weight or less, and particularly preferably 15% by weight or less. The lower limit is zero. If the content of the oxetane compound (particularly, the aliphatic oxetane compound) is excessive, it is difficult to obtain sufficient moisture resistance, which is not preferable.

  The composition for sealing an organic EL device of the present invention contains one or more cationic polymerization initiators together with the cationic polymerizable compound. Content of a cationic polymerization initiator is 0.01-5 weight part with respect to 100 weight part of cationically polymerizable compounds contained in the composition for organic electroluminescent element sealing of this invention, Preferably it is 0.05-3. Part by weight, particularly preferably 0.1 to 2 parts by weight.

  Since the composition for sealing an organic EL device of the present invention has the above-described configuration, it has a low viscosity, excellent fluidity, and excellent ink jetting properties. Therefore, the composition for sealing an organic EL device of the present invention may contain other components than the above as necessary, but it is not necessary to contain a solvent, and the content of the solvent is organic EL. For example, 30% by weight or less, preferably 20% by weight or less, particularly preferably 15% by weight or less, most preferably 10% by weight or less, and particularly preferably 5% by weight or less of the total amount of the element sealing composition. The lower limit is zero. Since the composition for sealing an organic EL element of the present invention can suppress the content of the solvent to zero or extremely low, it is possible to suppress the generation of outgas derived from the solvent remaining without being volatilized.

[Organic EL device sealing composition]
The composition for sealing an organic EL device of the present invention can be prepared by stirring and mixing the above cationic polymerizable compound and a cationic polymerization initiator. These can be used individually by 1 type or in combination of 2 or more types, respectively. The method of stirring and mixing is not particularly limited, and for example, various mixers such as a dissolver and a homogenizer, a kneader, a roll, a bead mill, a self-revolving stirrer and the like can be used. Further, after stirring and mixing, defoaming may be performed under vacuum.

  The composition for encapsulating an organic EL device of the present invention has a viscosity at 25 ° C. of 20 mPa · s or less, and thus has a low viscosity and an excellent ejection property from a nozzle of an inkjet head.

  Further, in the composition for sealing an organic EL device of the present invention, the content of the cationic polymerizable compound having a viscosity at 25 ° C. of 100 mPa · s or more is 20% by weight of the total amount of the cationic polymerizable compound contained in the composition. Since the content of the cationically polymerizable compound having a low fluidity is suppressed to be low, the injection property from the nozzle of the inkjet head is excellent.

  Furthermore, in the composition for sealing an organic EL device of the present invention, the content of the cationic polymerizable compound having a boiling point of 190 ° C. or lower under normal pressure is less than 20% by weight of the total amount of the cationic polymerizable compound contained in the composition. Since the content of the low-boiling cationically polymerizable compound is suppressed low, the organic EL element sealing composition of the present invention is prevented from solidifying and adhering to the nozzle opening of the inkjet head, Good injection can be maintained. That is, it can be stably applied by an ink jet printing method.

  When the volatile unreacted low molecular weight curable compound remains after the composition for sealing an organic EL element is irradiated with ultraviolet rays, the amount of outgas tends to increase, but the composition for sealing an organic EL element of the present invention Since the product uses a compound having fast curability as the curable compound, the polymerization reaction proceeds promptly by irradiation with ultraviolet rays, and the residual unreacted low molecular weight curable compound can be suppressed to a very low level. Therefore, the outgas amount at the time of hardening can be suppressed low. The outgas amount is, for example, 1000 ppm or less, preferably 800 ppm or less, more preferably 700 ppm or less, particularly preferably 550 ppm or less, most preferably 350 ppm or less, and particularly preferably 200 ppm or less. The outgas amount can be measured by the method described in the examples.

The composition for sealing an organic EL element of the present invention can be quickly cured by irradiating with ultraviolet rays to form a cured product. As the ultraviolet light source, any light source capable of generating an acid in the curable composition by irradiating light may be used. For example, a mercury lamp such as a UV-LED, a low, medium or high pressure mercury lamp. , Mercury xenon lamps, metal halide lamps, tungsten lamps, arc lamps, excimer lamps, excimer lasers, semiconductor lasers, YAG lasers, laser systems combining lasers and nonlinear optical crystals, high-frequency induced UV generators, etc. can be used . The ultraviolet irradiation amount (integrated light amount) is, for example, about 1000 to 2000 mJ / cm ² .

  The composition for sealing an organic EL device of the present invention may be further subjected to heat treatment after irradiation with ultraviolet rays. By performing the heat treatment, the degree of curing can be further improved. When performing heat processing, heating temperature is about 40-200 degreeC, and heating time is about 1 minute-15 hours.

The cured product of the composition for sealing an organic EL device of the present invention is excellent in moisture resistance, and has a water vapor transmission rate of, for example, 200 g / m ² · day · atm or less (eg, 50 to 200 g / m ² · day · atm), Preferably it is 180 g / m ² · day · atm or less, particularly preferably 160 g / m ² · day · atm or less, most preferably 120 g / m ² · day · atm or less, particularly preferably 100 g / m ² · day · atm or less. It is. The water vapor transmission rate can be measured by the method described in the examples.

  The cured product is excellent in transparency, and has a light transmittance (wavelength 400 nm) of, for example, 80% or more (preferably 86% or more).

  Since the composition for sealing an organic EL device of the present invention has a low viscosity and can suppress volatilization during printing, an increase in viscosity over time can be suppressed, and the composition is placed in the nozzle opening of an inkjet head. Is prevented from solidifying and adhering, and good injection can be maintained. Moreover, the transparent cured | curing material excellent in the low outgas property and moisture resistance can be rapidly formed by ultraviolet irradiation. Therefore, the composition for sealing an organic EL element of the present invention can be suitably used for an application for sealing an organic EL element using an inkjet printing method.

[Method of manufacturing organic EL device]
The manufacturing method of the organic EL device of the present invention is characterized in that the organic EL element sealing composition is applied by an ink jet printing method to seal the organic EL element.

  The said composition apply | coated by the inkjet printing method can form hardened | cured material by irradiating an ultraviolet-ray after that. The above-described method can be adopted as the ultraviolet irradiation method.

  According to the present invention, as described above, since the composition for sealing an organic EL element having excellent ink jetting properties and ink jetting stability is used, the composition can be stably, rapidly and uniformly formed by an ink jet printing method. Can be applied. Moreover, the said composition hardens | cures rapidly by ultraviolet irradiation. Therefore, it is excellent in workability and an organic EL device can be manufactured efficiently.

[Organic EL device]
The organic EL device of the present invention (for example, an organic EL display) has a configuration in which the organic EL element is sealed with a cured product of the organic EL element sealing composition.

  As described above, the cured product of the composition for sealing an organic EL element is excellent in moisture resistance and low outgassing properties and has transparency. For this reason, the organic EL device of the present invention has high luminance and a long life because deterioration of elements due to moisture is suppressed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited by these Examples.

Preparation Example 1 (Preparation of (2-phenylphenoxy) ethyl vinyl ether)
A 2 L 4-necked flask equipped with a condenser, a stirrer, and a thermometer was charged with sodium hydride (55% in mineral oil) (30.8 g, 705.8 mmol) and DMSO (509.4 g). A solution of o-phenylphenol (50.2 g, 250.7 mmol) in DMSO (171.6 g) was added dropwise at 0 ° C.
Thereafter, a solution of 2-chloroethyl vinyl ether (58.6 g, 550.0 mmol) in DMSO (46.0 g) was added dropwise to an oil bath at 60 ° C.
After stirring the reaction solution for 4 hours, the reaction solution was cooled to 0 ° C. and then slowly quenched by dropwise addition of water, and transferred to a separatory funnel.
The aqueous layer was extracted with ethyl acetate, and the organic layer was washed with saturated brine. Thereafter, the organic layer was separated and dehydrated with anhydrous sodium sulfate, and then the solvent was distilled off to obtain a liquid crude product. This was purified by silica gel column chromatography (hexane / ethyl acetate = 10/1) to obtain the desired product as a white solid (37.5 g, 44%).
¹ H-NMR (CDCl ₃ , 500MHz) δ 3.85 (s, 1.40H), 3.91 (s, 0.47H), 3.98-4.05 (m, 4.13H), 4.14-4.16 (m, 4H), 4.22-4.25 ( m, 2H), 6.47-6.54 (m, 2H), 6.80-6.89 (m, 2H), 7.06-7.09 (m, 4H), 7.12-7.16 (m, 4H).

Preparation Example 2 (Preparation of bisphenol F bis (vinyloxyethyl ether))
The same purpose as in Preparation Example 1 except that dihydroxydiphenylmethane (a mixture of 2,2′-dihydroxydiphenylmethane, 3,3′-dihydroxydiphenylmethane, and 4,4′-dihydroxydiphenylmethane) was used instead of o-phenylphenol. Product was obtained (37.5 g, 44%).
¹ H-NMR (CDCl ₃ , 500MHz) δ 3.85 (s, 1.40H), 3.91 (s, 0.47H), 3.98-4.05 (m, 4.13H), 4.14-4.16 (m, 4H), 4.22-4.25 ( m, 2H), 6.47-6.54 (m, 2H), 6.80-6.89 (m, 2H), 7.06-7.09 (m, 4H), 7.12-7.16 (m, 4H).

Examples 1-22, Comparative Examples 1-5
Each component was mixed by the prescription (unit: weight part) as described in the following table | surface, and the composition for sealing was obtained. About the obtained sealing composition, the viscosity, the inkjet ejection property, the injection stability, the UV curability, the outgas amount at the time of curing, and the water vapor transmission rate of the obtained cured product were measured by the following methods.

(viscosity)
The viscosities of the sealing compositions obtained in Examples and Comparative Examples were measured at 25 ° C. using an E-type viscometer.

(Inkjet ejection)
The inkjet ejection properties of the sealing compositions obtained in Examples and Comparative Examples were evaluated by the following method based on the viscosity.
Evaluation criteria ◎ (very good): viscosity at 25 ° C. is 15 mPa · s or less ○ (good): viscosity at 25 ° C. exceeds 15 mPa · s, 20 mPa · s or less × (poor): viscosity at 25 ° C. is 20 mPa · s over s

(Inkjet injection stability)
The inkjet ejection stability of the sealing compositions obtained in Examples and Comparative Examples was evaluated by the following method. That is, the sealing compositions obtained in Examples and Comparative Examples were subjected to an injection test using an inkjet printer (trade name “DMP-2831,” manufactured by Fuji Film Co., Ltd.) and evaluated according to the following criteria. .
Evaluation criteria ○ (good): injection was possible with high accuracy × (defect): flight bending occurred or nozzle opening was clogged and injection was not possible

(UV curable)
The UV curability of the encapsulating compositions obtained in Examples and Comparative Examples is that the encapsulating composition is applied on a glass substrate (thickness: 20 μm) and irradiated with ultraviolet rays with a 200 W / cm mercury lamp ( (Irradiation amount: 2000 mJ / cm ² ), the presence or absence of tackiness was examined by finger touch, and curability was evaluated according to the following criteria.
Evaluation criteria ○: No tack △: Slightly tack ×: Tack

(Outgas amount during curing)
60 mg of the composition for sealing obtained in Examples and Comparative Examples was put in a vial, and after UV irradiation (2000 mJ / cm ² ), the amount of outgas in the vial was measured. A calibration curve was prepared using a toluene standard solution [toluene as a standard substance: 100 ppm (60 μg), solvent: hexane (60 mg)]. In addition, as a measuring instrument, a trade name “HP-6890N” (manufactured by Hewlett-Packard) was used, and a trade name “DB-624” (manufactured by Agilent) was used as a column.

(Water vapor transmission rate)
About the hardened | cured material (thickness: 100 micrometers) obtained by UV irradiation (2000mJ / cm < ² >) to the coating film of the composition for sealing obtained in the Example and the comparative example, the water-vapor-permeation rate is set to JISL1099 and According to JIS Z 0208 (cup method), the measurement was performed under conditions of 60 ° C. and 90% RH.

＊沸点：圧力を記載したもの以外は全て常圧下における沸点である。

* Boiling point: Except for the pressure, all boiling points are under normal pressure.

<Cationically polymerizable compound>
E-1: (3,4,3 ′, 4′-diepoxy) bicyclohexyl, manufactured by Daicel Corporation e-2: bis (3,4-epoxycyclohexylmethyl) ether, manufactured by Daicel Corporation -3: 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate, trade name “Celoxide 2021P”, manufactured by Daicel Corporation, e-4: 2,3-bis (3,4-epoxycyclohexyl) ) Oxirane, manufactured by Daicel Corporation, e-5: 2,2-bis (3,4-epoxycyclohexane-1-yl) propane, manufactured by Daicel Corporation, OPP-EOVE: (2-phenylphenoxy) ethyl vinyl ether The product obtained in Preparation Example 1 was used. ONB-DVE: oxanorbornene divinyl ether, manufactured by Daicel Co., Ltd. OXBP: 4,4-bis [(3-ethyl -3-oxetanyl) methoxymethyl] biphenylyl, manufactured by Ube Industries, Ltd./OXT-121: 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, trade name “Aron Oxetane OXT-121” , Manufactured by Toagosei Co., Ltd., OXT-DVE: Oxetane divinyl ether, manufactured by Daicel Co., Ltd., YL-983U: bisphenol F diglycidyl ether, manufactured by Mitsubishi Chemical Corporation, HRM-C01: N-vinylcarbazole, Japan Fine Techno Chemical Co., Ltd., Celoxide 3000: 1, 2: 8,9-diepoxy limonene, Daicel Co., Ltd., CYCLOMER M100: 3,4-epoxycyclohexylmethyl methacrylate, Daicel Co., Ltd., ISB-DVE : Isosorbide divinyl ether, manufactured by Daicel Corporation, C DVE: cyclohexanedimethanol divinyl ether, manufactured by Nippon Carbide Industries, Ltd. ・ TEGDVE: triethylene glycol divininyl ether, manufactured by Nippon Carbide Industries, Ltd. ・ DEGDVE: diethylene glycol divinyl ether, manufactured by Nippon Carbide Industries, Ltd. ・ BisF-bis (VOE) E: bisphenol F bis (vinyloxyethyl ether), the one obtained in Preparation Example 2 was used. • OXT-221: 3-ethyl-3 {[(3-ethyloxetane-3-yl) methoxy] Methyl} oxetane, manufactured by Toagosei Co., Ltd. SR-16HJ: 1,6-hexanediol diglycidyl ether, manufactured by Sakamoto Pharmaceutical Co., Ltd. SR-14BJ: 1,4-butanediol diglycidyl ether, Sakamoto Pharmaceutical Co., Ltd.・ SR-PG: Propylene rubber Cold diglycidyl ether, Sakamoto Yakuhin Kogyo Co., Ltd. SR-NPG: Neopentyl glycol diglycidyl ether, Sakamoto Yakuhin Kogyo Co., Ltd. PGE: Phenyl glycidyl ether, Sakamoto Yakuhin Kogyo Co., Ltd., Celoxide 2000: 1 , 2-epoxy-4-vinylcyclohexane, manufactured by Daicel Corporation, OXT-212: 3-ethyl-3-[(2-ethylhexyloxy) methyl] oxetane, trade name “Aron oxetane OXT-212”, Toagosei Co., Ltd. Manufactured by BDVE: 1,4-butanediol divinyl ether, manufactured by Nippon Carbide Industries Co., Ltd. <cationic polymerization initiator>
4- (4-biphenylylthio) phenyl-4-biphenylylphenylsulfonium tetrakis (pentafluorophenyl) borate

Claims (9)

A composition containing a cationically polymerizable compound and a cationic polymerization initiator, wherein the viscosity at 25 ° C. is 20 mPa · s or less,
50 wt% or more of the total amount of the cationically polymerizable compound contained in the composition is an epoxy compound and / or a vinyl ether compound,
The content of the cationic polymerizable compound having a viscosity at 25 ° C. of 100 mPa · s or more is 20% by weight or less of the total amount of the cationic polymerizable compound contained in the composition, and the content of the cationic polymerizable compound having a boiling point of 190 ° C. or less under normal pressure The composition for organic electroluminescent element sealing for apply | coating by the inkjet printing method whose quantity is less than 20 weight% of the cationic polymerization compound whole quantity contained in a composition. The composition for organic electroluminescent element sealing of Claim 1 whose composition of a cationically polymerizable compound is following [1] or [2].
[1] When the content of the vinyl ether compound is less than 30% by weight of the total amount of the cationic polymerizable compound, the total content of the polyfunctional alicyclic epoxy compound represented by the following formula (a-1) and the glycidyl ether type epoxy compound Is a polyfunctional compound represented by the following formula (a-1) when the content of the vinyl ether compound is 30% by weight or more of the total amount of the cationically polymerizable compound. The content of the alicyclic epoxy compound is 5% by weight or more of the total amount of the cation polymerizable compound, and the total content of the polyfunctional alicyclic epoxy compound and the vinyl ether compound is 50% by weight or more of the total amount of the cation polymerizable compound.

(Wherein X represents a single bond or a linking group)   The polyfunctional alicyclic epoxy compound represented by the formula (a-1) is 3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate, (3,4,3 ′, 4′-diepoxy) Bicyclohexyl, bis (3,4-epoxycyclohexylmethyl) ether, 1,2-epoxy-1,2-bis (3,4-epoxycyclohexane-1-yl) ethane, and 2,2-bis (3,4 The composition for sealing an organic electroluminescent element according to claim 2, which is at least one compound selected from the group consisting of -epoxycyclohexane-1-yl) propane. The composition for organic electroluminescent element sealing of Claim 2 or 3 which contains the monofunctional alicyclic epoxy compound represented by a following formula (a-1 ') as a cationically polymerizable compound further.

(In the formula, R ^a1 represents a reactive functional group other than a cyclohexene oxide group, R ^a2 and R ^a3 are the same or different and represent a hydrogen atom or an alkyl group. L ′ represents a single bond or a linking group)   The composition for organic electroluminescent element sealing of any one of Claims 1-4 in which a vinyl ether compound contains the vinyl ether compound which has a ring structure at least.   The composition for organic electroluminescent element sealing of any one of Claims 1-5 whose outgas amount at the time of hardening is 1000 ppm or less. The composition for sealing an organic electroluminescence device according to any one of claims 1 to 6, wherein the water vapor permeability of the cured product is 200 g / m ² · day · atm or less.   An organic electroluminescence device, wherein the organic electroluminescence device sealing composition according to any one of claims 1 to 7 is applied by an ink jet printing method to seal the organic electroluminescence device. Production method.   The organic electroluminescent device which has the structure by which the organic electroluminescent element was sealed with the hardened | cured material of the composition for organic electroluminescent element sealing of any one of Claims 1-7.