JPWO2019082996A1 - Encapsulant for organic electroluminescence display elements - Google Patents

Abstract

It contains (A) an acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator, and the (B) cyclic monomer is a cyclic monofunctional (). A sealant for an organic electroluminescence display element that contains a meta) acrylate and a cyclic bifunctional (meth) acrylate and satisfies both the following formulas (I) and (III). 8 mPa · s ≤ η ≤ 50 mPa · s ... (I) γ / 2η <0.9 m / s ... (III) (In the formula, η represents the viscosity measured by an E-type viscometer at 25 ° C. , Γ represents the static surface tension measured by the pendant drop method.)

Description

The present invention relates to a sealant for an organic electroluminescence (EL) display element.

Organic electroluminescence (EL) devices (also referred to as OLED devices) are attracting attention as devices capable of emitting high-luminance light. However, the OLED element has a problem that it is deteriorated by moisture and its light emitting characteristics are deteriorated.

In order to solve such a problem, a technique for sealing an organic EL element and preventing deterioration due to moisture is being studied. For example, a method of sealing with a sealing material made of frit glass can be mentioned (see Patent Document 1).

An organic electroluminescence display element (see Patent Document 2) characterized in that the sealing layer is a laminate in which at least a barrier layer, a resin layer, and a barrier layer are sequentially formed, and an inorganic film and an organic film for sealing an organic EL element. A sealing layer in which the above-mentioned materials are alternately laminated, and a sealing glass substrate which is arranged so as to be in close contact with the uppermost organic material film of the sealing layer and cover the entire upper surface of the uppermost organic material film. An organic EL device (see Patent Document 3) characterized by the above has been proposed.

As a resin composition for encapsulating an organic EL element, an organic electroluminescence display element encapsulant containing a cyclic ether compound, a cationic polymerization initiator, and a polyfunctional vinyl ether compound (see Patent Document 4), cationically polymerizable. A cationically polymerizable resin composition containing a compound and a photocationic polymerization initiator or a thermal cationic polymerization initiator has been proposed (see Patent Document 5). As a resin composition for encapsulating an organic EL element, a (meth) acrylic resin composition has been proposed (Patent Documents 6 to 11).

Japanese Unexamined Patent Publication No. 10-74583 JP 2001-307873 JP-A-2009-37812 Japanese Unexamined Patent Publication No. 2014-225380 Japanese Unexamined Patent Publication No. 2012-190612 Japanese Unexamined Patent Publication No. 2014-229496 Japanese Unexamined Patent Publication No. 2014-196387 Japanese Unexamined Patent Publication No. 2014-193970 Japanese Unexamined Patent Publication No. 2014-193971 WO2014 / 157642A US2017 / 0062762

However, the prior art described in the above literature has room for improvement in the following points.

In Patent Document 1, when mass-producing, a method of sandwiching an organic EL element with a base material having low moisture permeability, for example, glass or the like, and sealing the outer peripheral portion is adopted. In this case, since this structure has a hollow sealing structure, it is not possible to prevent moisture from entering the hollow sealing structure, which causes a problem of deterioration of the organic EL element.

In Patent Documents 2 and 3, there is a problem that the thickness of the organic film is 3 μm or less because the organic film is formed by vapor deposition. If the thickness of the organic film is 3 μm or less, not only the particles generated during device formation cannot be completely covered, but also it is difficult to apply the particles on the inorganic film while maintaining flatness.

Patent Document 4 proposes a sealing agent using an epoxy-based material, but since such a material requires heating to cure, it damages the organic EL element and has a problem in terms of yield. It was. Patent Document 5 proposes a photocurable encapsulant using an epoxy-based material. However, since such a material is cured by UV light, the organic EL element is damaged by UV light and the yield is increased. There was a problem in that respect.

Patent Documents 6 to 10 describe that the water vapor transmittance is reduced as a characteristic required for such a sealing material, but the sealing material itself permeates through the pinholes of the passivation membrane, and the organic EL element. There is no description about the problem that reduces the reliability of the product and its countermeasures.

Although Patent Document 11 describes the use of cyclic monofunctional (meth) acrylate, it has not solved the problem that the unreacted product becomes outgas and leads to poor light emission of the organic EL element.

As described above, in the above-mentioned conventional technique, it has been a problem from the past that the ejection property when using the inkjet and the reliability of the organic EL element cannot be compatible with each other.

The present invention has been made in view of the above circumstances. For example, when used for encapsulating an organic EL element, the present invention provides a composition excellent in both ejection property when using an inkjet and reliability of the organic EL element. The purpose is.

The present invention can provide:

<1>
It contains (A) an acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator.
The cyclic monomer (B) contains a cyclic monofunctional (meth) acrylate and a cyclic bifunctional (meth) acrylate.
A sealant for an organic electroluminescence display element that satisfies both the following formulas (I) and (III).
8 mPa ・ s ≦ η ≦ 50 mPa ・ s ・ ・ ・ (I)
γ / 2η <0.9m / s ・ ・ ・ (III)
(In the formula, η represents the viscosity measured by the E-type viscometer at 25 ° C., and γ represents the static surface tension measured by the pendant drop method.)

<2>
It contains (A) an acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator.
The component (A) and the component (B) are contained in an amount of 10 to 85 parts by mass and the component (B) is contained in an amount of 15 to 90 parts by mass with respect to a total of 100 parts by mass.
The cyclic monomer (B) contains a cyclic monofunctional (meth) acrylate and a cyclic bifunctional (meth) acrylate.
The content ratio of the cyclic monofunctional (meth) acrylate and the cyclic bifunctional (meth) acrylate is a cyclic monofunctional (meth) acrylate in a mass ratio of 100 parts by mass of the total of the cyclic monofunctional (meth) acrylate and the cyclic bifunctional (meth) acrylate. Meta) Acrylate: A sealant for an organic electroluminescence display element having a cyclic bifunctional (meth) acrylate = 10 to 95: 90 to 5 and satisfying the following formulas (I), (II) and (III) together.
8 mPa ・ s ≦ η ≦ 50 mPa ・ s ・ ・ ・ (I)
14 mN / m ≤ γ ≤ 40 mN / m ... (II)
γ / 2η <0.9m / s ・ ・ ・ (III)
(In the formula, η represents the viscosity measured by the E-type viscometer at 25 ° C., and γ represents the static surface tension measured by the pendant drop method.)

<3>
(B) The encapsulant for an organic electroluminescence display element according to <1> or <2>, wherein the cyclic monomer contains one or more kinds of alicyclic monomers.

<4>
The encapsulant for an organic electroluminescence display element according to any one of <1> to <3>, which contains a fluorine atom and a fluorine-containing monomer having a (meth) acryloyl group as a component (E).

<5>
The encapsulant for an organic electroluminescence display element according to <4>, wherein the fluorine atom content of the fluorine-containing monomer is 2 to 70% by mass based on the total amount of the fluorine-containing monomer.

［式（Ｅ−１）中、
Ｒ¹は、水素原子又はメチル基を示し、
Ｒ²は、フッ化アルキル基、又は、フッ化アルキル基における炭素−炭素結合及び炭素−水素結合の一部に酸素原子が挿入された基、を示す。複数存在するＲ³は、互いに同一でも異なっていてもよい。］
式（Ｅ−２）

［式（Ｅ−２）中、
Ｒ³は、水素原子又はメチル基を示し、
Ｒ⁴は、フッ化アルカンジイル基、又は、フッ化アルカンジイル基における炭素−炭素結合及び炭素−水素結合の一部に酸素原子が挿入された基、を示す。複数存在するＲ³は、互いに同一でも異なっていてもよい。］
式（Ｅ−３）

［式（Ｅ−３）中、
Ｒ⁵は水素原子又はメチル基を示し、
Ｒ⁶は、単結合、アルカンジイル基、フッ化アルカンジイル基、又は、アルカンジイル基若しくはフッ化アルカンジイル基における炭素−炭素結合及び炭素−水素結合の一部に酸素原子が挿入された基、を示し、
Ａｒ¹はフッ化アリール基を示す。］<6>
The fluorine-containing monomer is at least one selected from the group consisting of a compound represented by the formula (E-1), a compound represented by the formula (E-2) and a compound represented by the formula (E-3). The encapsulant for an organic electroluminescence display element according to <4> or <5>, which comprises.
Equation (E-1)

[In equation (E-1),
R ¹ represents a hydrogen atom or a methyl group
R ² indicates an alkyl fluoride group or a group in which an oxygen atom is inserted as a part of a carbon-carbon bond and a carbon-hydrogen bond in the alkyl fluoride group. A plurality of R ^3s may be the same or different from each other. ]
Equation (E-2)

[In equation (E-2),
R ³ represents a hydrogen atom or a methyl group
R ⁴ indicates an alkanediyl fluoride group or a group in which an oxygen atom is inserted as a part of a carbon-carbon bond and a carbon-hydrogen bond in the alkanediyl fluoride group. A plurality of R ^3s may be the same or different from each other. ]
Equation (E-3)

[In formula (E-3),
R ⁵ represents a hydrogen atom or a methyl group
R ⁶ is a single bond, an alkanediyl group, an alkanediyl fluoride group, or a group in which an oxygen atom is inserted as part of a carbon-carbon bond or a carbon-hydrogen bond in an alkanediyl group or an alkanediyl fluoride group. Shows,
Ar ¹ represents an aryl fluoride group. ]

［式（Ｅ−１−１）中、Ｒ¹は水素原子又はメチル基を示し、Ｒ²¹は水素原子又はフッ素原子を示し、ｎは１以上の整数を示す。複数存在するＲ²¹は互いに同一でも異なっていてもよい。但し、Ｒ²¹の少なくとも一つはフッ素原子である。］
式（Ｅ−２−１）

［式（Ｅ−２−１）中、Ｒ³は水素原子又はメチル基を示し、Ｒ⁴¹は水素原子又はフッ素原子を示し、ｍは１以上の整数を示す。複数存在するＲ⁴¹は、互いに同一でも異なっていてもよい。但し、Ｒ⁴¹の少なくとも一つはフッ素原子である。複数存在するＲ³は、互いに同一でも異なっていてもよい。］
式（Ｅ−３−１）

［式（Ｅ−３−１）中、Ｒ⁵は水素原子又はメチル基を示し、Ｒ⁶¹は水素原子又はフッ素原子を示し、Ｒ⁶²は水素原子又はフッ素原子を示し、ｐは０以上の整数を示す。複数存在するＲ⁶¹は、互いに同一でも異なっていてもよい。複数存在するＲ⁶²は、互いに同一でも異なっていてもよい。但し、Ｒ⁶²の少なくとも一つはフッ素原子である。］<7>
The group in which the fluorine-containing monomer consists of a compound represented by the formula (E-1-1), a compound represented by the formula (E-2-1), and a compound represented by the formula (E-3-1). The encapsulant for an organic electroluminescence display element according to <6>, which comprises at least one selected from the above.
Equation (E-1-1)

[In the formula (E-1-1), R ¹ represents a hydrogen atom or a methyl group, R ²¹ represents a hydrogen atom or a fluorine atom, and n represents an integer of 1 or more. A plurality of R ^21s may be the same or different from each other. However, at least one of R ²¹ is a fluorine atom. ]
Equation (E-2-1)

[In the formula (E-2-1), R ³ represents a hydrogen atom or a methyl group, R ⁴¹ represents a hydrogen atom or a fluorine atom, and m represents an integer of 1 or more. A plurality of R ^41s may be the same or different from each other. However, at least one of R ⁴¹ is a fluorine atom. A plurality of R ^3s may be the same or different from each other. ]
Equation (E-3-1)

[In formula (E-3-1), R ⁵ represents a hydrogen atom or a methyl group, R ⁶¹ represents a hydrogen atom or a fluorine atom, R ⁶² represents a hydrogen atom or a fluorine atom, and p is an integer of 0 or more. Is shown. A plurality of R ^61s may be the same or different from each other. A plurality of R ^62s may be the same or different from each other. However, at least one of R ⁶² is a fluorine atom. ]

<8>
The content of the component (E) is in the range of 0.1 part by mass to 10 parts by mass with respect to 100 parts by mass in total of the component (A) and the component (B) <4> to <. The encapsulant for an organic electroluminescence display element according to any one of 7>.

<9>
The component (E) is 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluoro-1,10-decanedioldi ( It is characterized by containing one or more selected from the group consisting of meta) acrylates, 1H, 1H, 5H-octafluoropentyl (meth) acrylates, and 1H, 1H, 2H, 2H-tridecafluorooctyl (meth) acrylates. The encapsulant for an organic electroluminescence display element according to any one of <4> to <8>.

<10>
The encapsulant for an organic electroluminescence display element according to any one of <1> to <9>, which is applied by using an inkjet method.

<11>
Any of <1> to <10>, which is characterized by not containing a bifunctional (meth) acrylate oligomer, a bifunctional (meth) acrylate polymer, a polyfunctional (meth) acrylate oligomer, or a polyfunctional (meth) acrylate polymer. A sealant for an organic electroluminescence display element according to.

<12>
The sealant for an organic electroluminescence display element according to any one of <1> to <11>, wherein the glass transition temperature of the cured product is 65 ° C. or higher and 120 ° C. or lower.

<13>
The sealant for an organic electroluminescence display element according to any one of <1> to <12>, wherein at least one of the components (B) has two or more cyclic structures in the molecule.

<14>
The sealant for an organic electroluminescence display element according to any one of <1> to <13>, wherein at least two of the components (B) have two or more cyclic structures in the molecule.

（式中のＲはそれぞれ独立に水素原子又はメチル基である。式中のｍ、ｎに関して、ｍ＋ｎ＝２〜１０である）<15>
The component (B) is ethoxylated-o-phenylphenol (meth) acrylate, m-phenoxybenzyl (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, and ethoxylated bisphenol A represented by the following structural formula. The encapsulant for an organic electroluminescence display element according to any one of <1> to <14>, which contains one or more of the group consisting of di (meth) acrylate.

(R in the formula is independently a hydrogen atom or a methyl group. With respect to m and n in the formula, m + n = 2 to 10)

<16>
The sealant for an organic electroluminescence display element according to any one of <1> to <15>, wherein the component (A) is an alkanediol di (meth) acrylate having 12 or less carbon atoms.

<17>
One or more of the group (A) consisting of 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, and 1,12-dodecanediol di (meth) acrylate. The sealant for an organic electroluminescent display element according to any one of <1> to <16>, which comprises.

<18>
The encapsulant for an organic electroluminescence display element according to any one of <1> to <17>, wherein the component (C) contains 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide.

<19>
The encapsulant for an organic electroluminescence display element according to any one of <1> to <18>, wherein the content of the component (C) is 0.5 to 4 parts by mass.

<20>
The sealant for an organic electroluminescence display element according to any one of <1> to <19>, which further contains (D) an antioxidant.

<21>
The sealant for an organic electroluminescence display element according to <20>, wherein the component (D) is a hindered phenolic antioxidant.

<22>
The encapsulant for an organic electroluminescence display element according to <20> or <21>, which contains two or more kinds of the component (D).

<23>
The sealant for an organic electroluminescence display element according to any one of <1> to <22>, which is cured at a wavelength of 395 nm or more and 500 nm or less.

<24>
The sealant for an organic electroluminescence display element according to <23>, which is cured with an LED lamp having a diameter of 395 nm.

<25>
A cured product obtained by curing the sealant for an organic electroluminescence display element according to any one of <1> to <24>.

<26>
An organic EL device containing the cured product according to <25>.

<27>
A display containing the cured product according to <25>.

<28>
A flexible display comprising the cured product according to <25>.

<29>
A flexible organic EL device containing the cured product according to <25>.

The encapsulant according to the present invention has an effect that it is excellent in ejection property when using an inkjet and also excellent in reliability of the obtained organic EL element.

Hereinafter, this embodiment will be described. Unless otherwise specified, the numerical range described in the present specification shall include an upper limit value and a lower limit value. In the present specification, unless otherwise specified, the following definitions are used. (Meta) acrylate represents acrylate or methacrylate, and notations such as "(meth) acryloyloxy" and "(meth) acrylamide" have the same meaning. The "monofunctional (meth) acrylate" refers to a (meth) acrylate having one (meth) acrylic group, and the "bifunctional (meth) acrylate" refers to a (meth) acrylate having two (meth) acrylic groups. Point to. The "polyfunctional (meth) acrylate" refers to a (meth) acrylate having three or more (meth) acrylic groups, and does not contain a bifunctional (meth) acrylate.

Hereinafter, a top-emission type organic EL device that emits light from the side opposite to the substrate of the organic EL element formed on the substrate will be described as an example. The top-emission type organic EL device is an organic EL element in which an anode, an organic EL layer including a light emitting layer, and a cathode are sequentially laminated on a substrate, and an inorganic film and an organic film are laminated to cover the entire organic EL element. It has a structure in which a sealing layer made of a film and a sealing substrate provided on the sealing layer are sequentially formed.

As the substrate, various materials such as a glass substrate, a silicon substrate, and a plastic substrate can be used. Among these, one or more of the group consisting of a glass substrate and a plastic substrate is preferable, and a glass substrate is more preferable.

Plastics used for plastic substrates include polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, polyoxadiazol, aromatic polyamide, polybenzoimidazole, polybenzobisthiazole, polybenzoxazole, polythiazole, and polyparaphenylene. Examples thereof include vinylene, polymethylmethacrylate, polystyrene, polycarbonate, polycycloolefin, polyacrylic and the like. Among these, polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, polyoxadiazole, aromatic polyamide, polybenzoimidazole, and polybenzo are excellent in low moisture permeability, low oxygen permeability, and heat resistance. One or more of the group consisting of bistazole, polybenzoxazole, polythiazole, and polyparaphenylene vinylene is preferable, and polyimide, polyetherimide, and polyethylene terephthalate are highly transparent to energy rays such as ultraviolet rays or visible light. , One or more of the group consisting of polyethylene naphthalate is more preferable.

As the anode, a conductive metal oxide film, a translucent metal thin film, or the like having a relatively large work function (preferably one having a work function larger than 4.0 eV) is generally used. Examples of the material of the anode include indium tin oxide (hereinafter referred to as ITO), metal oxides such as tin oxide, gold (Au), platinum (Pt), silver (Ag), copper (Cu) and the like. Examples thereof include organic transparent conductive films such as the metal of the above, alloys containing at least one of them, polyaniline or a derivative thereof, polythiophene or a derivative thereof. The anode can be formed by a layer structure of two or more layers, if necessary. The film thickness of the anode can be appropriately selected in consideration of the electric conductivity (in the case of the bottom emission type, the light transmission). The film thickness of the anode is preferably 10 nm to 10 μm, more preferably 20 nm to 1 μm, and most preferably 50 nm to 500 nm. Examples of the method for producing the anode include a vacuum deposition method, a sputtering method, an ion plating method, a plating method and the like. In the case of the top emission type, a reflective film for reflecting the light emitted to the substrate side may be provided under the anode.

The organic EL layer contains at least a light emitting layer made of an organic substance. This light emitting layer contains a light emitting material. Examples of the luminescent material include organic substances (low molecular weight compounds or high molecular weight compounds) that emit fluorescence or phosphorescence. The light emitting layer may further contain a dopant material. Examples of organic substances include pigment-based materials, metal complex-based materials, and polymer materials. The dopant material is doped in the organic substance for the purpose of improving the luminous efficiency of the organic substance and changing the emission wavelength. The thickness of the light emitting layer composed of these organic substances and a dopant that is optionally doped is 2 to 200 nm.

(Dye material)
Dye materials include cyclopendamine derivatives, tetraphenylbutadiene derivative compounds, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, pyrrole derivatives, thiophene ring compounds, and pyridines. Examples thereof include ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifmanylamine derivatives, oxaziazole dimers, pyrazoline dimers and the like.

(Metal complex material)
Examples of the metal complex material include metal complexes that emit light from a triple-term excited state such as iridium complexes and platinum complexes, aluminum quinolinol complexes, benzoquinolinol berylium complexes, benzoxazolyl zinc complexes, benzothiazole zinc complexes, and azomethyl zinc complexes. , Metal complexes such as porphyrin zinc complex, europium complex and the like. The metal complex has a rare earth metal such as terbium (Tb), europium (Eu), dysprosium (Dy), aluminum (Al), zinc (Zn), beryllium (Be), etc. in the central metal, and is a ligand. Examples thereof include oxadiazole, thiadiazol, phenylpyridine, phenylbenzimidazole, metal complexes having a quinoline structure and the like. Among these, a metal complex having aluminum (Al) as the central metal and a quinoline structure or the like as the ligand is preferable. Among metal complexes having aluminum (Al) as the central metal and a quinoline structure as the ligand, tris (8-hydroxyquinolinato) aluminum is preferable.

(Polymer material)
Examples of the polymer material include polyparaphenylene vinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polymerized dyes and metal complex-based luminescent materials. Can be mentioned.

Among the above-mentioned luminescent materials, examples of the material that emits blue light include dystilyl arylene derivatives, oxadiazole derivatives, polyvinylcarbazole derivatives, polyparaphenylene derivatives, polyfluorene derivatives, and polymers thereof. Of these, polymer materials are preferred. Among the polymer materials, one or more of the group consisting of polyvinylcarbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives is preferable.

Examples of the material that emits green light include a quinacridone derivative, a coumarin derivative, a polyparaphenylene vinylene derivative, a polyfluorene derivative, and a polymer thereof. Of these, polymer materials are preferred. Among the polymer materials, one or more of the group consisting of polyparaphenylene vinylene derivatives and polyfluorene derivatives is preferable.

Examples of the material that emits red light include coumarin derivatives, thiophene ring compounds, polyparaphenylene vinylene derivatives, polythiophene derivatives, polyfluorene derivatives, and polymers thereof. Of these, polymer materials are preferred. Among the polymer materials, one or more of the group consisting of polyparaphenylene vinylene derivatives, polythiophene derivatives, and polyfluorene derivatives is preferable.

(Dopant material)
Examples of the dopant material include perylene derivative, coumarin derivative, rubrene derivative, quinacridone derivative, squalium derivative, porphyrin derivative, styryl dye, tetracene derivative, pyrazolone derivative, decacyclene, phenoxazone and the like.

In addition to the light emitting layer, the organic EL layer may be appropriately provided with a layer provided between the light emitting layer and the anode and a layer provided between the light emitting layer and the cathode. First, as a layer provided between the light emitting layer and the anode, a hole injection layer for improving the hole injection efficiency from the anode and holes injected from the anode or the hole injection layer are transported to the light emitting layer. Examples include a hole transport layer. Examples of the layer provided between the light emitting layer and the cathode include an electron injection layer for improving the electron injection efficiency from the cathode, an electron transport layer for transporting electrons injected from the cathode or the electron injection layer to the light emitting layer, and the like. Be done.

(Hole injection layer)
Materials for forming the hole injection layer include phenylamines such as 4', 4 "-tris {2-naphthyl (phenyl) amino} triphenylamine, starburst amines, phthalocyanine, vanadium oxide, and molybdenum oxide. , Oxides such as ruthenium oxide and aluminum oxide, amorphous carbon, polyaniline, polythiophene derivatives and the like.

(Hole transport layer)
Materials constituting the hole transport layer include polyvinylcarbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine in the side chain or the main chain, a pyrazoline derivative, an arylamine derivative, a stilben derivative, and triphenyldiamine. Derivatives, benzidine derivatives, polyaniline or its derivatives, polythiophene or its derivatives, polyarylamine or its derivatives, polypyrrole or its derivatives, poly (p-phenylene vinylene) or its derivatives, poly (2,5-thienylene vinylene) or its derivatives Derivatives and the like can be mentioned.

When these hole injection layers or hole transport layers have a function of blocking the transport of electrons, these hole transport layers or hole injection layers may be referred to as electron block layers.

(Electronic transport layer)
Examples of the material constituting the electron transport layer include oxadiazole derivative, anthraquinodimethane or its derivative, benzoquinone or its derivative, naphthoquinone or its derivative, anthraquinone or its derivative, tetracyanoanthraquinodimethane or its derivative, and fluorenone derivative. , Diphenyldicyanoethylene or its derivative, diphenoquinone derivative, 8-hydroxyquinolin or its derivative, polyquinolin or its derivative, polyquinoxalin or its derivative, polyfluorene or its derivative and the like. Examples of the derivative include a metal complex and the like. Among these, 8-hydroxyquinoline or a derivative thereof is preferable. Among 8-hydroxyquinoline or its derivative, tris (8-hydroxyquinolinato) aluminum is preferable because it can be used as an organic substance that emits fluorescence or phosphorescence contained in the light emitting layer.

(Electron injection layer)
The electron injection layer is an electron injection layer having a single-layer structure of a calcium (Ca) layer, or a metal of Group IA and Group IIA of the Periodic Table, and has a work function of 1, depending on the type of light emitting layer. .Single-layer structure of a layer formed of one or more of the group consisting of a metal of 5 to 3.0 eV and an oxide of the metal, a halide and a carbon oxide, or a group of IA and IIA of the periodic table. Lamination of Ca layer and a layer formed of one or more of the group consisting of a metal and a metal having a work function of 1.5 to 3.0 eV and an oxide, halide and carbon oxide of the metal. Examples thereof include an electron injection layer having a structure. Metals of Group IA of the Periodic Table or oxides thereof, halides and coal oxides having a work function of 1.5 to 3.0 eV include lithium (Li), lithium fluoride, sodium oxide, lithium oxide, lithium carbonate and the like. Can be mentioned. Metals of Group IIA of the Periodic Table with a work function of 1.5 to 3.0 eV or their oxides, halides, and coal oxides include strontium (Sr), magnesium oxide, magnesium fluoride, strontium fluoride, and fluoride. Examples thereof include barium, strontium oxide and magnesium carbonate.

When these electron transport layers or electron injection layers have a function of blocking the transport of holes, these electron transport layers and electron injection layers may be referred to as hole block layers.

As the cathode, a transparent or translucent material having a relatively small work function (preferably having a work function smaller than 4.0 eV) and easily injecting electrons into the light emitting layer is preferable. Materials for the cathode include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), beryllium (Be), magnesium (Mg), calcium (Ca), and strontium (Sr). , Barium (Ba), Aluminum (Al), Scandium (Sc), Vanadium (V), Zinc (Zn), Ittrium (Y), Indium (In), Terbium (Ce), Samarium (Sm), Europium (Eu) , Terbium (Tb), Itterbium (Yb) and other metals, or alloys consisting of two or more of the above metals, or one or more of them, and gold (Au), silver (Ag), platinum (Pt), An alloy consisting of one or more of copper (Cu), chromium (Cr), manganese (Mn), titanium (Ti), cobalt (Co), nickel (Ni), tungsten (W), tin (Sn), or an alloy. , Graphite or graphite interlayer compounds, or metal oxides such as ITO and tin oxide.

The cathode may have a laminated structure of two or more layers. Examples of the laminated structure of two or more layers include the above-mentioned metals, metal oxides, fluorides, alloys thereof, and laminated structures of metals such as Al, Ag, and Cr. The film thickness of the cathode can be appropriately selected in consideration of electrical conductivity and durability. The film thickness of the cathode is preferably 10 nm to 10 μm, more preferably 15 nm to 1 μm, and most preferably 20 nm to 500 nm. Examples of the method for producing the cathode include a vacuum vapor deposition method, a sputtering method, and a laminating method in which a metal thin film is thermocompression bonded.

The layer provided between the light emitting layer and the anode and between the light emitting layer and the cathode can be appropriately selected according to the performance required for the organic EL device to be manufactured. For example, the structure of the organic EL element used in the present embodiment may have any of the following layer configurations (i) to (xv).
(I) Anophode / hole transport layer / light emitting layer / cathode (ii) anode / light emitting layer / electron transport layer / cathode (iii) anode / hole transport layer / light emitting layer / electron transport layer / cathode (iv) anode / Hole injection layer / light emitting layer / cathode (v) anode / light emitting layer / electron injection layer / cathode (vi) anode / hole injection layer / light emitting layer / electron injection layer / cathode (vii) anode / hole injection layer / Hole transport layer / light emitting layer / cathode (viii) anode / hole transport layer / light emitting layer / electron injection layer / cathode (ix) anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode (X) Electron / hole injection layer / light emitting layer / electron transport layer / cathode (xi) anode / light emitting layer / electron transport layer / electron injection layer / cathode (xii) anode / hole injection layer / light emitting layer / electron transport Layer / electron injection layer / cathode (xiii) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode (xiv) anode / hole transport layer / light emitting layer / electron transport layer / electron injection layer / Cathode (xv) anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode (where, "/" indicates that each layer is laminated adjacent to each other. same as below.)

The sealing layer is provided to seal the organic EL element with a layer having a high barrier property against the gas in order to prevent a gas such as water vapor or oxygen from coming into contact with the organic EL element. In this sealing layer, an inorganic film and an organic film are alternately formed from below. The inorganic / organic laminate may be formed repeatedly two or more times.

In an active matrix type display device in which the current to each organic EL element is controlled by a thin film transistor (TFT) provided for each pixel, unevenness of 0.5 μm to 3 μm due to the TFT and the partition wall separating the blue, green, and red pixels is generated. It exists between the cathode or anode and the sealing layer. In the active matrix type display device, it is necessary to flatten the above-mentioned unevenness by the sealing layer to reduce the influence of interference with light emission, and further improve the sealing performance. When the sealing layer is formed by the sealing agent according to the present embodiment, the effect of obtaining good flatness can be obtained.

The inorganic film of the inorganic / organic laminate is a film provided to prevent the organic EL element from being exposed to a gas such as water vapor or oxygen existing in the environment in which the organic EL device is placed. The inorganic film of the inorganic / organic laminate is preferably a continuous and dense film with few defects such as pinholes. Examples of the inorganic film include a single film such as a SiN film, a SiO film, a SiON film, an Al ₂ O ₃ film, and an AlN film, and a laminated film thereof.

The organic film of the inorganic / organic laminate is provided to provide flatness to the surface in order to cover defects such as pinholes formed on the inorganic film. The organic film is formed in a region narrower than the region where the inorganic film is formed. This is because if the organic film is formed equal to or wider than the formation region of the inorganic film, it deteriorates in the region where the organic film is exposed. However, the uppermost organic film formed on the uppermost layer of the entire sealing layer is formed in substantially the same region as the formation region of the inorganic film. Then, the upper surface of the sealing layer is formed so as to be flattened. As the organic film, a composition having an adhesive function having good adhesion performance with the above-mentioned inorganic film is used.

This embodiment is suitable for, for example, an inkjet coating capable of coating with an excellent flatness of a film thickness of 3 μm or more in a short time, has excellent ejection properties by an inkjet and flatness after the inkjet application, and has a barrier property against water vapor and the like ( The organic electroluminescence display element that forms the organic film, which not only has low moisture permeability) but also that the encapsulant itself does not permeate through the pinholes on the inorganic film and the reliability of the organic EL element does not decrease. It is an object of the present invention to provide a sealant for use. By using the coating method by the inkjet method, the organic film can be formed at high speed and uniformly.

If the encapsulant itself permeates through the pinholes on the inorganic film, not only does the OLED element around the pinholes stop emitting light, but also the encapsulant permeates the organic light emitting material layer during long-term use, increasing light emission defects. However, so-called dark spots will occur. That is, the reliability of the OLED element is significantly reduced.

（式１）By the way, according to Lucas-Washburn (Equation 1), which is a basic formula for liquid permeation, the permeation depth l to the pinhole is the time (t) after the liquid comes into contact with the solid. It can be seen that it depends on the pore size (r), the viscosity of the liquid (η), the surface tension of the liquid (γ), and the contact angle with the solid surface (θ).

(Equation 1)

In Equation 1, the contact angle θ with the solid surface and the pore diameter r are parameters that depend on the inorganic film. Therefore, as a sealing agent, the penetration rate is controlled by Equation 2 to improve the reliability of the organic EL element. I found something to do.

γ / 2η <0.9m / s ・ ・ ・ Equation 2

As will be described later, in the organic EL element, there is a problem that dark spots are generated due to the penetration of the sealing agent and light emission failure occurs. By satisfying the condition of the above formula 2, the permeation of such a sealing agent is suppressed.

The viscosity of the composition of the present embodiment is preferably 8 mPa · s or more and 50 mPa · s or less, which is measured under the conditions of 25 ° C. and 100 rpm using an E-type viscometer. If it is difficult to eject by inkjet, heat the inkjet head as appropriate. When the viscosity is less than 8 mPa · s, the coated sealant for the organic EL display element not only flows out from the organic EL display element before curing, but also flows into the pinhole on the inorganic film, and the reliability of the OLED element. Decreases. If the viscosity exceeds 50 mPa · s, it becomes difficult to apply by inkjet. The viscosity of the composition is more preferably 8 mPa · s to 25 mPa · s.

The static surface tension of the composition of the present embodiment is preferably 14 mN / m or more and 40 mN / m or less. The static surface tension is measured by the plate method, the ring method, the pendant drop method, or the like, but the value of the static surface tension specified in the present embodiment is based on the pendant drop method. The pendant drop method is a method of extruding a liquid from the tip of a tube and calculating the surface tension from the shape of a hanging drop (pendant drop). When the static surface tension is less than 14 mN / m, the coated sealant for the organic EL display element not only flows out from the organic EL display element before curing, but also flows into the pinhole on the inorganic film and flows into the OLED element. The reliability of the is reduced. If the static surface tension exceeds 40 mN / m, it becomes difficult to apply by inkjet. The static surface tension of the composition is more preferably 20 mN / m to 30 mN / m.

The composition of the present embodiment contains (A) an acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator (meth). It is an acrylic resin composition. The component (B) contains at least a cyclic monofunctional (meth) acrylate and a cyclic bifunctional (meth) acrylate.

(A) The acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms means a bifunctional (meth) acrylate having 6 or more carbon atoms in the main chain alkane. The acyclic component (A) does not have a cyclic molecular structure. As the component (A), α, ω-linear alkanediol di (meth) acrylate is preferable because it has a large effect on low moisture permeability, ejection property by an inkjet, and flatness after application to an inkjet. More preferably, the main chain alkane can have 12 or less carbon atoms. Among the α, ω-linear alkanediol di (meth) acrylates, 1,6-hexadioldi (meth) acrylate, 1,9-nonanediol di (meth) acrylate, and 1,10-decanediol di (meth) acrylate ) Acrylate, preferably one or more of the group consisting of 1,12-dodecanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, One or more of the group consisting of 1,12-dodecanediol di (meth) acrylate is more preferable, and 1,12-dodecanediol di (meth) acrylate is most preferable. The alkane, which is the main chain of the component (A), may be a straight chain or a branched chain. Preferably, the component (A) does not have a fluorine atom and is distinguished from the component (E) described later.

The content of the component (A) is preferably 10 to 85 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B). When the content of (A) is 10 parts by mass or more, low moisture permeability is obtained, and when it is 85 parts by mass or less, the viscosity becomes high and the reliability of the organic EL element is improved. The content of (A) is preferably 30 to 70 parts by mass, more preferably 35 to 68 parts by mass, and most preferably 45 to 65 parts by mass in terms of low moisture permeability and reliability of the organic EL element.

The cyclic monomer (B) has a group having a cyclic structure in the molecule, and has one unsaturated double bond group selected from the group consisting of a (meth) acrylate group, a (meth) acrylamide group and an N-vinyl group. It is a monomer having more than one. That is, the component (B) having a cyclic structure is different from the component (A) having an acyclic structure. Examples of such a cyclic structure include a heterocyclic structure containing a cyclic amide group, a tetrahydrofurfuryl group, a piperidinyl group and the like, an aromatic hydrocarbon-based cyclic structure, a monomer having an aliphatic hydrocarbon-based cyclic structure, and the like. .. Among them, one or more of the group consisting of monomers having an aromatic hydrocarbon-based cyclic structure and an aliphatic hydrocarbon-based cyclic structure is preferable in terms of ejection property by inkjet and low moisture permeability. More preferably, a cyclic (meth) acrylate monomer having an aromatic hydrocarbon-based cyclic structure and an aliphatic hydrocarbon-based cyclic structure can be used as the component (B). Preferably, the component (B) does not have a fluorine atom and is distinguished from the component (E) described later.

Examples of the (meth) acrylate having an aromatic hydrocarbon-based cyclic structure include benzyl (meth) acrylate, 4-butylphenyl (meth) acrylate, phenyl (meth) acrylate, and 2,4,5-tetramethylphenyl (meth). ) Acrylate, 4-chlorophenyl (meth) acrylate, phenoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate (2-HPA), 2- (meth) acrylicloy Loxyhexahydrophthalic acid, 2- (meth) acryloyloxyethyl-2-hydroxypropylphthalic acid, EO-modified phenol (meth) acrylate, EO-modified cresol (meth) acrylate, EO-modified nonylphenol (meth) acrylate, PO-modified nonylphenol Monofunctional (meth) acrylate having one or more aromatic hydrocarbon-based cyclic structures in the molecule such as (meth) acrylate, ethoxylated-o-phenylphenol (meth) acrylate, m-phenoxybenzyl (meth) acrylate, etc. Bifunctional (meth) acrylates such as ethoxylated bisphenol A di (meth) acrylate, propoxylated bisphenol A di (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) acrylate, and bisphenol A epoxy di (meth) acrylate. Can be mentioned. One or more of these may be used in combination. In particular, the encapsulant for an organic electroluminescence display element according to the present embodiment preferably has two or more cyclic structures in the molecule in terms of low moisture permeability and reliability of the organic EL element. Examples of the (meth) acrylate having two or more aromatic hydrocarbon-based cyclic structures in the molecule include ethoxylated-o-phenylphenol (meth) acrylate, m-phenoxybenzyl (meth) acrylate, and ethoxylated bisphenol A di (meth). One or more of the group consisting of meta) acrylate is preferable, and one or more of the group consisting of ethoxylated-o-phenylphenol (meth) acrylate and ethoxylated bisphenol A di (meth) acrylate is more preferable.

Examples of the alicyclic hydrocarbon group in the monomer having an aliphatic hydrocarbon-based cyclic structure include a group having a dicyclopentadiene skeleton such as a dicyclopentanyl group and a dicyclopentenyl group, a cyclohexyl group, an isobornyl group, and a cyclodecatorien. Examples include a group, a norbornyl group, an adamantyl group and the like. Among these, a group having a dicyclopentadiene skeleton is preferable. Examples of the (meth) acrylate having an alicyclic hydrocarbon group include cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentenyl (meth) acrylate. Examples thereof include cyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, and methoxylated cyclodecatriene (meth) acrylate. Examples of the (meth) acrylate having a dicyclopentadiene skeleton include tricyclodecanedimethanol di (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopentenyloxyethyl (meth). ) One or more of the group consisting of acrylate is preferable, and one or more of the group consisting of dicyclopentanyl (meth) acrylate and tricyclodecanedimethanol di (meth) acrylate is more excellent in terms of low moisture permeability. preferable.

The present inventor has found that the cyclic monomer (B) needs to contain a mixture of a cyclic monofunctional (meth) acrylate and a cyclic bifunctional (meth) acrylate in a predetermined ratio. This is due to the following reasons. Cyclic monofunctional (meth) acrylate is highly effective in terms of low moisture permeability, but there is a problem that unreacted material becomes outgas due to its low boiling point, resulting in poor light emission of the organic EL element. Cyclic bifunctional (meth) acrylate has excellent low moisture permeability and low volatility, so it is highly effective in terms of reliability of OLED devices, but it has a problem of adversely affecting inkjet ejection properties due to its relatively high viscosity. .. The present inventor uses a cyclic monofunctional (meth) acrylate and a cyclic bifunctional (meth) acrylate in combination at a predetermined ratio to achieve both low moisture permeability and OLED device reliability that cannot be achieved by conventional techniques. We have found that an effect can be obtained and came up with the present invention. That is, the content ratio of the monofunctional (meth) acrylate and the bifunctional (meth) acrylate is the mass ratio of the total of 100 parts by mass of the methacrylate and the acrylate, and the monofunctional (meth) acrylate: bifunctional (meth) acrylate = 10 to 10 The range of 95: 90 to 5 is preferable, the range of 40 to 90: 60 to 10 is more preferable, and the range of 65 to 85: 35 to 15 is most preferable.

（上記式中のＲ₁はそれぞれ独立に水素原子又はメチル基であり、ｎの平均値は１〜１０が好ましく、特に好ましくはｎ＝１である。）、及び、下記構造式で表される環状単官能（メタ）アクリレート

（上記式中のＹは−ＣＨ₂−，−（ＣＨ（Ｒ⁵）ＣＨ₂Ｏ）_m1−，−（ＣＨ（Ｒ⁵）ＣＨ₂Ｓ）_m2−（但し、Ｒ⁵は水素原子又はメチル基、ｍ１及びｍ２は１〜４の数である）であり、Ｒ³は水素原子又はメチル基であり、Ｒ⁴は下記構造式で表わされるいずれかの置換基である）。

As the cyclic monofunctional (meth) acrylate, any of the following compounds is preferable.
Cyclic monofunctional (meth) acrylate represented by the following structural formula

(R ₁ in the above formula is independently a hydrogen atom or a methyl group, and the average value of n is preferably 1 to 10, particularly preferably n = 1.) And is represented by the following structural formula. Cyclic monofunctional (meth) acrylate

(Y in the above formula is −CH ₂ −, − (CH (R ⁵ ) CH ₂ O) _m1 −, − (CH (R ⁵ ) CH ₂ S) _m2 − (However, R ⁵ is a hydrogen atom or a methyl group. , M1 and m2 are numbers 1 to 4), R ³ is a hydrogen atom or a methyl group, and R ⁴ is any of the substituents represented by the following structural formula).

As the cyclic bifunctional (meth) acrylate, an ethoxylated bisphenol A di (meth) acrylate compound represented by the following structural formula is preferable. R in the following formula is independently a hydrogen atom or a methyl group. With respect to m and n in the formula, m + n = 2 to 10 is preferable.

Of the components (B), at least one preferably has two or more cyclic structures in the molecule, and at least two preferably have two or more cyclic structures in the molecule.

The content of the component (B) is preferably 15 to 90 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B). When the content of (B) is 15 parts by mass or more, the viscosity becomes high and the reliability of the organic EL element is improved, and when it is 90 parts by mass or less, the inkjet coatability is excellent. The content of (B) is preferably 30 to 70 parts by mass, more preferably 32 to 65 parts by mass, and most preferably 45 to 65 parts by mass in terms of low moisture permeability and reliability of the organic EL device.

(C) The photopolymerization initiator is used to accelerate the photocuring of the resin composition by sensitizing it with active light of visible light or ultraviolet light. As the photopolymerization initiator, a photoradical polymerization initiator is preferable. Examples of the photoradical polymerization initiator include benzoyl derivatives such as benzophenone and its derivatives, benzyl and its derivatives, entraquinone and its derivatives, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, and benzyl dimethyl ketal. Acetphenone derivatives such as diethoxyacetophenone and 4-tert-butyltrichloroacetonone, 2-dimethylaminoethylbenzoate, p-dimethylaminoethylbenzoate, diphenyldisulfide, thioxanthone and its derivatives, camphorquinone, 7,7-dimethyl-2,3 -Dioxobicyclo [2.2.1] heptane-1-carboxylic acid, 7,7-dimethyl-2,3-dioxobicyclo [2.2.1] heptane-1-carboxy-2-bromoethyl ester, 7,7-Dimethyl-2,3-dioxobicyclo [2.2.1] heptane-1-carboxy-2-methyl ester, 7,7-dimethyl-2,3-dioxobicyclo [2.2.1] ] Benzoyl quinone derivatives such as heptane-1-carboxylic acid chloride, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- Α-Aminoalkylphenone derivatives such as (4-morpholinophenyl) -butanone-1, benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, benzoyldiethoxyphosphine oxide, 2,4,6 Acylphosphine oxide derivatives such as -trimethylbenzoyldimethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiethoxyphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, phenyl-glycylic acid -Methyl ester, oxy-phenyl-acetylid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl ester, oxy-phenyl-acetylid 2- [2-hydroxy-ethoxy] -ethyl ester, etc. Can be mentioned. One or more photopolymerization initiators can be used in combination. Among these, the acylphosphine oxide derivative is preferable in that it can be cured by using only visible light having a diameter of 390 nm or more and can be cured without damaging the organic electroluminescence display element. Among the acylphosphine oxide derivatives, 2,4,6-trimethylbenzoyl-diphenyl can be cured using only light of 395 nm or more without lowering the transparency in visible light when used as a display. -Phosphine oxide is most preferred. Examples of the 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide include "Irgacure TPO" manufactured by BASF Japan Ltd.

The content of the photopolymerization initiator (C) is preferably 0.05 to 6 parts by mass, more preferably 0.5 to 4 parts by mass, based on 100 parts by mass of the total of the components (A) and (B). , 2 to 3.9 parts by mass is most preferable, and 2.5 to 3.5 parts by mass is even more preferable. If the content of the component (C) is 0.05 parts by mass or more, the effect of accelerating curing can be surely obtained, and if it is 6 parts by mass or less, the transparency in visible light decreases when used for a display. There is nothing to do.

In the composition of the present embodiment, the (meth) acrylate is preferably a monomer from the viewpoint of inkjet ejection property. The component (A) and the component (B) are preferably monomers. The molecular weight of the monomer is preferably 1000 or less. In terms of inkjet ejection property, the bifunctional (meth) acrylate oligomer / polymer and the polyfunctional (meth) acrylate oligomer / polymer are 3 in 100 parts by mass of the (meth) acrylate containing the component (A) and the component (B). It is preferably contained in an amount of 1 part by mass or less, more preferably contained in an amount of 1 part by mass or less, and most preferably not contained.

The composition of the present embodiment may contain a fluorine atom and a fluorine-containing monomer having a (meth) acryloyl group as the component (E) from the viewpoint of lowering the free energy of the surface after coating and obtaining high flatness. preferable. The (meth) acryloyl group indicates an acryloyl group or a methacryloyl group. One type of fluorine-containing monomer may be used alone, or two or more types may be used in combination.

The content of the component (E) is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 4 parts by mass, based on 100 parts by mass of the total of the components (A) and (B). 9 to 1.6 parts by mass is even more preferable. If it is 0.1 part by mass or more, flatness can be ensured, and if it is 10 parts by mass or less, good inkjet coatability can be ensured.

The number of fluorine atoms contained in the fluorine-containing monomer as the component (E) may be 1 or more, for example, 2 or more, and preferably 3 or more. The upper limit of the number of fluorine atoms contained in the fluorine-containing monomer is not particularly limited, and may be, for example, 40 or less, preferably 30 or less.

The content of the fluorine atom with respect to the total amount of the fluorine-containing monomer may be, for example, 1% by mass or more, preferably 2% by mass or more, and more preferably 5% by mass or more. The content of fluorine atoms may be, for example, 75% by mass or less, preferably 70% by mass or less, and more preferably 65% by mass or less, based on the total amount of fluorine-containing monomers. Further, the content of fluorine atoms with respect to the total amount of the composition according to the embodiment containing the component (E) is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass. When the content of the fluorine atom is within the above range, the effect of improving the flatness can be obtained.

The number of (meth) acryloyl groups contained in the fluorine-containing monomer may be 1 or more. From the viewpoint that a cured product having a low glass transition temperature can be easily obtained, the number of (meth) acryloyl groups contained in the fluorine-containing monomer may be one. Further, from the viewpoint that a cured product having a high glass transition temperature can be easily obtained, the number of (meth) acryloyl groups contained in the fluorine-containing monomer may be 2 or more. The upper limit of the number of (meth) acryloyl groups contained in the fluorine-containing monomer is not particularly limited, and may be, for example, 4 or less, and is preferably 3 or less, more preferably 3 or less, from the viewpoint of easily obtaining a cured product having excellent flexibility. Is 2 or less.

As one specific example of the fluorine-containing monomer, a compound represented by the following formula (E-1) can be mentioned.

Equation (E-1)

In formula (E-1), R ¹ represents a hydrogen atom or a methyl group. Further, R ² indicates an alkyl fluoride group or a group in which an oxygen atom is inserted as a part of a carbon-carbon bond and a carbon-hydrogen bond in the alkyl fluoride group.

The alkyl fluoride group can be said to be a group in which a part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. The number of carbon atoms of the alkyl fluoride group is not particularly limited, and may be, for example, 1 or more, preferably 2 or more. Further, the number of carbon atoms of the alkyl fluoride group may be, for example, 25 or less, or 20 or less.

As the alkyl fluoride group, a group containing difluoromethylene (−CF _2- ) can be preferably used.

Specific examples of the alkyl fluoride group include a difluoromethyl group, a trifluoromethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a 1,1,1-trifluoroethyl group, and 2,2. 2-Trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, 1,1,2,2,3,3 -Hexafluoropropyl group, perfluoropropyl group, perfluoroethylmethyl group, 1- (trifluoromethyl) -1,2,2,2-tetrafluoroethyl group, 2,2,3,3-tetrafluoropropyl group, perfluoro Propyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,1,2,2,3,3-peptafluoro Butyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis (trifluoro) methyl-2,2,2-trifluoroethyl group, 2- (Perfluoropropyl) ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, 2,2,3,3,4,5,5-octafluoropentyl group , Perfluoropentyl group, 1,1,2,2,3,3,4,5,5-decafluoropentyl group, 1,1-bis (trifluoromethyl) -2,2,3,3,3 -Pentafluoropropyl group, 2- (perfluorobutyl) ethyl group, 1,1,1,2,2,3,3,4,4-nonafluoropentyl group, 1,1,2,2,3,3 4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,5,5,6,6-dodecafluorohexyl group, perfluorohexyl group, perfluoropentylmethyl group And perfluorohexyl groups and the like.

A group in which an oxygen atom is inserted in a part of a carbon-carbon bond and a carbon-hydrogen bond in an alkyl fluoride group (hereinafter, also referred to as an oxygen-containing group of R ² ) is a group in which an oxygen atom is inserted in one place. It may be a group inserted in two or more places.

When an oxygen atom is inserted into a carbon-carbon bond, an ether bond is formed. Also, when an oxygen atom is inserted into a carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of R ² can be said to be a group containing at least one selected from the group consisting of an ether bond and a hydroxyl group.

Specific examples of the oxygen-containing group of R ² include a group represented by the following formula.

The fluorine atom content in the compound represented by the formula (E-1) may be, for example, 5% by mass or more, preferably 15% by mass or more, and more preferably 30% by mass or more. The fluorine atom content in the compound represented by the formula (E-1) may be, for example, 75% by mass or less, preferably 70% by mass or less, and more preferably 65% by mass or less.

As one of the specific examples of the compound represented by the formula (E-1), for example, the compound represented by the following formula (E-1-1) can be mentioned.

Equation (E-1-1)

In the formula (E-1-1), R ¹ represents a hydrogen atom or a methyl group, R ²¹ represents a hydrogen atom or a fluorine atom, and n represents an integer of 1 or more. A plurality of R ^21s may be the same or different from each other. However, at least one of R ²¹ is a fluorine atom.

n may be 1 or more, preferably 2 or more. Further, the upper limit of n is not particularly limited, and may be, for example, 25 or less, or 20 or less.

A plurality of R ²¹ are present in the formula (E-1-1), and at least one of them is a fluorine atom. Further, among R ²¹ , it is preferable that two or more are fluorine atoms, and more preferably three or more are fluorine atoms. All R ²¹ may be fluorine atoms.

The ratio of the number of fluorine atoms to the total number of R ²¹ may be, for example, 4% or more, preferably 8% or more, and more preferably 12% or more. The ratio may be, for example, 100% or less, preferably 80% or less, and more preferably 75% or less.

The compound represented by the formula (E-1-1) is a divalent group of n is attached in brackets _{^{(-C (R 21) 2 -}} ) among the at least one of difluoromethylene (-CF ₂ - ) Is preferable.

As another specific example of the fluorine-containing monomer, a compound represented by the following formula (E-2) can be mentioned.

Equation (E-2)

In formula (E-2), R ³ represents a hydrogen atom or a methyl group. Further, R ⁴ indicates an alkanediyl fluoride group or a group in which an oxygen atom is inserted as a part of a carbon-carbon bond and a carbon-hydrogen bond in the alkanediyl fluoride group. A plurality of R ^3s may be the same or different from each other.

The fluorinated alkanediyl group can be said to be a group in which a part or all of the hydrogen atoms of the alkanediyl group are substituted with fluorine atoms. The number of carbon atoms of the alkanediyl fluoride group is not particularly limited, and may be, for example, 1 or more, preferably 2 or more, more preferably 3 or more, and further preferably 4 or more. The number of carbon atoms of the alkanediyl fluoride group may be, for example, 17 or less, preferably 12 or less, and more preferably 10 or less.

As the fluorinated alkanediyl group, a group containing difluoromethylene (−CF ₂₋ ) can be preferably used.

Specific examples of the cycloalkane fluoride group include a linear or branched alkanediyl fluoride group having 1 to 17 carbon atoms (for example, 2,2,3,3,4,5,5,6). , 6,7,7,8,8,9,9-hexadecafluoro-1,10-decandyl group), cycloalkanediyl fluoride group having 1 to 17 carbon atoms and the like.

An oxygen atom is inserted in one place in a group in which an oxygen atom is inserted in a part of a carbon-carbon bond and a carbon-hydrogen bond in an alkanediyl fluoride group (hereinafter, also referred to as an oxygen-containing group of R ⁴ ). It may be a group or a group inserted in two or more places.

When an oxygen atom is inserted into a carbon-carbon bond, an ether bond is formed. Also, when an oxygen atom is inserted into a carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of R ⁴ can be said to be a group containing at least one selected from the group consisting of an ether bond and a hydroxyl group.

Specific examples of the oxygen-containing group of R ⁴ include a group represented by the following formula.

The fluorine atom content in the compound represented by the formula (E-2) may be, for example, 4% by mass or more, preferably 8% by mass or more, and more preferably 12% by mass or more. The fluorine atom content in the compound represented by the formula (E-2) may be, for example, 90% by mass or less, preferably 75% by mass or less, and more preferably 65% by mass or less.

As one of the specific examples of the compound represented by the formula (E-2), for example, the compound represented by the following formula (E-2-1) can be mentioned.

Equation (E-2-1)

In formula (E-2-1), R ³ represents a hydrogen atom or a methyl group, R ⁴¹ represents a hydrogen atom or a fluorine atom, and m represents an integer of 1 or more. A plurality of R ^41s may be the same or different from each other. A plurality of R ^3s may be the same or different from each other. However, at least one of R ⁴¹ is a fluorine atom.

m may be 1 or more, preferably 2 or more, more preferably 3 or more, and further preferably 4 or more. The upper limit of m is not particularly limited, and may be, for example, 20 or less, preferably 17 or less, and more preferably 15 or less.

A plurality of R ^41s are present in the formula (E-2-1), and at least one of them is a fluorine atom. Further, among R ⁴¹ , it is preferable that two or more are fluorine atoms, and more preferably four or more are fluorine atoms. All R ⁴¹ may be fluorine atoms.

The ratio of the number of fluorine atoms to the total number of R ⁴¹ may be, for example, 1% or more, preferably 5% or more, and more preferably 10% or more. The ratio may be, for example, 100% or less, preferably 95% or less, and more preferably 90% or less.

The compound represented by the formula (E-2-1) is a divalent group of m is attached in brackets _{^{(-C (R 41) 2 -}} ) among the at least one of difluoromethylene (-CF ₂ - ) Is preferable.

As another specific example of the fluorine-containing monomer, a compound represented by the following formula (E-3) can be mentioned.

Equation (E-3)

In formula (E-3), R ⁵ represents a hydrogen atom or a methyl group. Further, in R ⁶ , an oxygen atom was inserted into a part of a carbon-carbon bond and a carbon-hydrogen bond in a single bond, an alkanediyl group, an alkanediyl fluoride group, or an alkanediyl group or an alkanediyl fluoride group. The group is shown. In addition, Ar ¹ represents an aryl fluoride group.

In addition, "R ⁶ shows a single bond" means that Ar ¹ and an oxygen atom are directly bonded.

As the aryl fluoride group of Ar ¹ , a phenyl fluoride group is preferable. It can also be said that the phenyl group is a group in which 1 to 5 hydrogen atoms in the phenyl group are replaced with fluorine atoms. The phenyl fluoride group may have one or more fluorine atoms, and may have five fluorine atoms.

The number of carbon atoms of the alkanediyl group of R ⁶ is not particularly limited, and may be, for example, 1 or more. Further, the number of carbon atoms of the alkanediyl group of R ⁶ may be, for example, 17 or less, preferably 15 or less, and more preferably 12 or less.

Specific examples of the alkanediyl group include a linear or branched alkanediyl group having 1 to 17 carbon atoms (for example, a methylene group, an ethylene group, etc.), a cycloalkanediyl group having 1 to 17 carbon atoms, and the like. Be done.

It can be said that the fluorinated alkanediyl group of R ⁶ is a group in which a part or all of the hydrogen atoms of the above-mentioned alkanediyl group are substituted with fluorine atoms. The number of carbon atoms of the alkanediyl fluoride group of R ⁶ is not particularly limited, and may be, for example, 1 or more. The number of carbon atoms of the alkanediyl fluoride group of R ⁶ may be, for example, 17 or less, preferably 15 or less, and more preferably 12 or less.

As the fluorinated alkanediyl group of R ⁶ , a group containing difluoromethylene (−CF ₂₋ ) can be preferably used.

A group in which an oxygen atom is inserted in a part of a carbon-carbon bond or a carbon-hydrogen bond in an alkanediyl group or an alkanediyl fluoride group (hereinafter, also referred to as an oxygen-containing group of R ⁶ ) has one oxygen atom. It may be a group inserted in, or it may be a group inserted in two or more places.

When an oxygen atom is inserted into a carbon-carbon bond, an ether bond is formed. Also, when an oxygen atom is inserted into a carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of R ⁶ can be said to be a group containing at least one selected from the group consisting of an ether bond and a hydroxyl group.

Specific examples of the oxygen-containing group of R ⁶ include a group containing −CH ₂ CH ₂ O− and the like.

The fluorine atom content in the compound represented by the formula (E-3) may be, for example, 3% by mass or more, preferably 7% by mass or more, and more preferably 15% by mass or more. The fluorine atom content in the compound represented by the formula (E-3) may be, for example, 90% by mass or less, preferably 80% by mass or less, and more preferably 70% by mass or less.

As one of the specific examples of the compound represented by the formula (E-3), for example, the compound represented by the following formula (E-3-1) can be mentioned.

Equation (E-3-1)

In formula (E-3-1), R ⁵ represents a hydrogen atom or a methyl group, R ⁶¹ represents a hydrogen atom or a fluorine atom, R ⁶² represents a hydrogen atom or a fluorine atom, and p is an integer of 0 or more. Shown. When p is 1 or more, a plurality of R ^61s existing may be the same or different from each other. Further, the plurality of R ^62s existing may be the same or different from each other. However, at least one of R ⁶² is a fluorine atom.

p indicates an integer of 0 or more. Here, when p is 0, it means that the benzene ring and the oxygen atom are directly bonded. p may be an integer of 1 or more. The upper limit of p is not particularly limited, and may be, for example, 17 or less, preferably 15 or less, and more preferably 12 or less.

When R ⁶¹ is present in the formula (E-3-1) (that is, when p is an integer of 1 or more), R ⁶¹ may be all hydrogen atoms or all fluorine atoms. , A part may be a hydrogen atom and the other part may be a fluorine atom.

A plurality of R ^62s are present in the formula (E-3-1), and at least one of them is a fluorine atom. Further, in R ⁶² , two or more may be fluorine atoms, and three or more may be fluorine atoms or more. Further, all (5) of R ⁶² may be fluorine atoms.

The ratio of the number of fluorine atoms to the total number of R ⁶¹ and R ⁶² may be, for example, 5% or more, preferably 10% or more, and more preferably 20% or more. The ratio may be, for example, 100% or less, preferably 95% or less, and more preferably 80% or less.

Among the fluorine-containing monomers, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9 are preferable from the viewpoint of low moisture permeability and inkjet coating property. , 9-Hexadecafluoro-1,10-decanediol di (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, and 1H, 1H, 2H, 2H-tridecafluorooctyl (meth) acrylate. It is one or more of the group consisting of.

The glass transition temperature of the cured product obtained from the composition of the present embodiment is preferably 65 ° C. or higher and 120 ° C. or lower, more preferably 65 ° C. or higher and 110 ° C. or lower, and 70 ° C. or higher and 100 ° C. or higher, in view of the reliability of the organic EL device. Most preferably below ° C. When the glass transition temperature of the cured product is in the range of 65 ° C. or higher and 120 ° C. or lower, stress is relaxed when an inorganic passivation film is formed on the cured product of the composition of the present embodiment by a method such as CVD. Since the inorganic film and the OLED element are hard to be peeled off, the reliability of the organic EL element is improved.

The method for measuring the glass transition temperature of the cured product obtained from the composition of the present embodiment is not particularly limited, but it is measured by a known method such as DSC or dynamic viscoelasticity spectrum, and a dynamic viscoelasticity spectrum is preferably used. Be done. In the dynamic viscoelastic spectrum, stress and strain are applied to the cured product at a constant temperature rise rate, and the temperature showing the peak top of the loss tangent (hereinafter abbreviated as tan δ) can be defined as the glass transition temperature. If the peak of tan δ does not appear even if the temperature is raised from a sufficiently low temperature of about −150 ° C. to a certain temperature (Ta ° C.), the glass transition temperature is considered to be −150 ° C. or lower or a certain temperature (Ta ° C.) or higher. However, since a composition having a glass transition temperature of −150 ° C. or lower is unthinkable due to its structure, it can be set to a certain temperature (Ta ° C.) or higher.

In the composition of the present embodiment, (D) an antioxidant can be used for improving storage stability. Antioxidants include methylhydroquinone, hydroquinone, 3- [3,5-di-tert-butyl-4-hydroxyphenyl] octadecyl propionate, 2,2-methylene-bis (4-methyl-6-tert-butylphenol). ), Catecol, hydroquinone monomethyl ether, monotert-butylhydroquinone, 2,5-ditert-butylhydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,5-ditert-butyl-p-benzoquinone. , Picric acid, citric acid, phenothiazine, tert-butylcatechol, 2-butyl-4-hydroxyanisole and 2,6-ditert-butyl-p-cresol and the like. It is preferable to combine two or more kinds of antioxidants. Among these, phenolic antioxidants are preferable because they have great effects such as transparency and storage stability. Among the phenolic antioxidants, hindered phenolic antioxidants are preferred. Examples of the hindered phenolic antioxidant include 3- [3,5-di-tert-butyl-4-hydroxyphenyl] octadecyl propionate and 2,2-methylene-bis (4-methyl-6-tert-butylphenol). One or more of the group consisting of 3- [3,5-di-tert-butyl-4-hydroxyphenyl] propionate octadecyl and 2,2-methylene-bis (4-methyl-6-tert-) are preferred. Butylphenol) is more preferred. Examples of the octadecyl 3- [3,5-di-tert-butyl-4-hydroxyphenyl] propionate include "Irganox 1076" manufactured by BASF Japan Ltd. Examples of 2,2-methylene-bis (4-methyl-6-tert-butylphenol) include "SUMILIZER MDP-S" manufactured by Sumitomo Chemical Co., Ltd. When containing 3- [3,5-di-tert-butyl-4-hydroxyphenyl] octadecyl propionate and 2,2-methylene-bis (4-methyl-6-tert-butylphenol), 3- [3, The content ratio of octadecyl 5-di-tert-butyl-4-hydroxyphenyl] propionate and 2,2-methylene-bis (4-methyl-6-tert-butylphenol) is 3- [3,5-di-tert]. -Butyl-4-hydroxyphenyl] Octadecil propionate and 2,2-methylene-bis (4-methyl-6-tert-butylphenol) in a total of 100 parts by mass in a mass ratio of 3- [3,5-di- tert-Butyl-4-hydroxyphenyl] octadecyl propionate: 2,2-methylene-bis (4-methyl-6-tert-butylphenol) = 10-90: 90-10, preferably 25-75: 75-25. More preferred.

The content of the antioxidant is preferably 0.001 to 3 parts by mass, more preferably 0.01 to 2 parts by mass, based on 100 parts by mass of the total of the components (A) and (B). If it is 0.001 part by mass or more, storage stability is ensured, and if it is 3 parts by mass or less, good adhesiveness is obtained and it does not become uncured.

The composition according to the present embodiment may further contain additives used in the art, such as antioxidants, metal inactivating agents, fillers, stabilizers, neutralizers, lubricants, antibacterial agents and the like. May be contained.

The composition of this embodiment can be used as a resin composition. The composition of this embodiment can be used as a photocurable resin composition. The composition of this embodiment can be used as a sealing agent for an organic EL display element.

Examples of the method of irradiating the composition with visible light or ultraviolet rays to cure the composition include a method of irradiating the composition with at least one of visible light or ultraviolet rays to cure the composition. Examples of energy irradiation sources for irradiating such visible light or ultraviolet rays include heavy hydrogen lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, low-pressure mercury lamps, xenon lamps, xenon-mercury mixed lamps, halogen lamps, and excima lamps. Examples include energy irradiation sources such as indium lamps, tallium lamps, LED lamps, and electrodeless discharge lamps. The composition of the present embodiment is preferably cured at a wavelength of 380 nm or more, more preferably at a wavelength of 395 nm or more, and cured at a wavelength of 395 nm because it is difficult to damage the organic EL element. Most preferred. The wavelength of the energy irradiation source is preferably 500 nm or less because the temperature of the irradiated portion rises due to the emission of infrared light, which may damage the organic EL element. As the energy irradiation source, an LED lamp having a single emission wavelength is preferable.

When the composition is cured by irradiating it with visible light or ultraviolet rays, it is preferable to irradiate the composition with energy rays of 100 to 8000 mJ / cm ^{2 at} a wavelength of 395 nm to cure the composition. If it is 100 to 8000 mJ / cm ² , the composition is cured and sufficient adhesive strength can be obtained. 100 mJ / cm ² or more value, if the composition is sufficiently cured, does not damage the organic EL element if 8000 mJ / cm ² or less. The amount of energy for curing the composition is more preferably 300 to 2000 mJ / cm ² .

Regarding the transparency of the composition of the present embodiment, when the thickness of the organic film is 1 μm or more and 10 μm or less, the spectral transmittance in the ultraviolet-visible light region of 360 nm or more and 800 nm or less is preferably 95% or more, preferably 97% or more. More preferably, 99% or more is most preferable. If it is 95% or more, it is possible to provide an organic EL device having excellent brightness and contrast.

The sealing layer made of the composition of the present embodiment is preferably 1 to 5 sets when the inorganic / organic laminate is counted as one set. This is because when the number of inorganic / organic laminates is 6 or more, the sealing effect on the organic EL element is almost the same as that of 5 sets. The thickness of the inorganic film of the inorganic / organic laminate is preferably 50 nm to 1 μm. The thickness of the organic film of the inorganic / organic laminate is preferably 1 to 15 μm, more preferably 3 to 10 μm. If the thickness of the organic film is less than 1 μm, the particles generated during device formation cannot be completely covered, and it may be difficult to apply the organic film on the inorganic film with good flatness. If the thickness of the organic material film exceeds 15 μm, water may enter from the side surface of the organic material film, and the reliability of the organic EL element may decrease.

The sealing substrate is formed in close contact so as to cover the entire upper surface of the uppermost organic film of the sealing layer. Examples of this sealing substrate include the above-mentioned substrates. Among these, a substrate transparent to visible light is preferable. Among the substrates transparent to visible light (transparent sealed substrate), one or more of the group consisting of a glass substrate and a plastic substrate is preferable, and a glass substrate is more preferable.

The thickness of the transparent sealing substrate is preferably 1 μm or more and 1 mm or less, more preferably 10 μm or more and 800 μm or less, and most preferably 50 μm or more and 300 μm or less. By providing the transparent sealing substrate further above the sealing layer, it is possible to suppress deterioration that progresses when the surface of the uppermost organic film comes into contact with a gas, and it is possible to enhance the barrier property of the organic EL device.

Next, a method of manufacturing an organic EL device having such a configuration will be described. First, an anode, an organic EL layer including a light emitting layer, and a cathode, which are patterned into a predetermined shape, are sequentially formed on the first substrate by a conventionally known method to form an organic EL element. For example, when an organic EL device is used as a dot matrix display device, a bank is formed to divide a light emitting region into a matrix, and an organic EL layer including a light emitting layer is formed in the region surrounded by the bank.

Next, the substrate on which the organic EL element is formed has a predetermined thickness by a film forming method such as a PVD (Physical Vapor Deposition) method such as a sputtering method or a CVD method such as a plasma CVD (Chemical Vapor Deposition) method. It forms the first inorganic film. Then, the composition of the present embodiment is adhered onto the first inorganic film by using a coating film forming method such as a solution coating method or a spray coating method, a flash vapor deposition method, an inkjet method, or the like. Among these, the inkjet method is preferable from the viewpoint of productivity. After that, the composition is cured by irradiation with energy rays such as ultraviolet rays, electron beams, and plasma, and a first organic film is formed. By the above steps, a set of inorganic / organic laminates is formed. The curing rate of the composition is not particularly limited as long as the effects of the present embodiment are exhibited, but for example, the value obtained according to the measurement method described later can be 90% or more, preferably 95% or more.

The step of forming the inorganic / organic laminate shown above is repeated a predetermined number of times. However, for the final set, that is, the uppermost inorganic / organic laminate, the composition is adhered to the upper surface of the inorganic film by a coating method, a flash vapor deposition method, an inkjet method, etc. so that the upper surface is flattened. Is also good.

Next, the transparent sealing substrate is attached to the surface of the substrate to which the composition is attached. At the time of bonding, alignment is performed. Then, by irradiating energy rays from the transparent sealing substrate side, the composition of the present embodiment existing between the uppermost inorganic film and the transparent sealing substrate is cured. As a result, the composition is cured to form the uppermost organic film, and the uppermost organic film and the transparent sealing substrate are adhered to each other. This completes the method for manufacturing the organic EL device.

After adhering the composition on the inorganic film, the composition may be partially irradiated with energy rays to polymerize. By doing so, it is possible to prevent the shape of the composition, which is the uppermost organic film, from being deformed when the transparent sealing substrate is placed. The thickness of the inorganic film and the organic film may be the same for each inorganic / organic laminate, or may be different for each inorganic / organic laminate.

In the above description, a top emission type organic EL device has been described as an example. The present embodiment can also be applied to a bottom emission type organic EL device that emits light generated in the organic EL layer from the substrate side.

The organic EL element of this embodiment can be used as a planar light source, a segment display device, and a dot matrix display device.

According to the present embodiment, a sealing layer for blocking the organic EL element formed on the first substrate from the outside air is formed, and a transparent sealing substrate is further arranged on the sealing layer, so that it is organic. It is possible to obtain a sealing structure having sufficient barrier properties against water vapor and oxygen for the EL element. According to the embodiment of the present embodiment, it is possible to obtain a sealing structure having sufficient adhesive strength between the transparent sealing substrate and the sealing layer.

According to the present embodiment, after the composition of the present embodiment constituting the uppermost organic film of the sealing layer is adhered, a transparent sealing substrate is placed without curing the composition, and then the composition is formed. Since the material is cured, it is possible to bond the sealing layer and the transparent sealing substrate at the same time as forming the uppermost organic film forming the sealing layer. As a result, the present embodiment has an effect that the process can be simplified as compared with the case where the sealing layer and the transparent sealing substrate are bonded with an adhesive.

The composition of the present embodiment has a moisture permeation value of 350 g / m at a thickness of 100 μm measured by exposing the cured product to an environment of 85 ° C. and 85% RH for 24 hours in accordance with JIS Z 0208: 1976. It is preferably m ² or less. If the moisture permeability exceeds 350 g / m ² , moisture may reach the organic light emitting material layer and dark spots may be generated.

According to this embodiment, it is possible to provide a sealing agent for an organic EL display element which can be easily applied by an inkjet method and has excellent reliability of an OLED element, transparency of a cured product and barrier properties. According to this embodiment, it is possible to provide a method for manufacturing an organic EL display element using a sealing agent for an organic EL display element. The inkjet method is a method in which fine droplets are ejected from a nozzle and applied to an object in a non-contact manner.

(Experimental Examples 1-8)
A composition was prepared and evaluated by the following method.

(Preparation of composition)
The materials used in Table 1 were used. Each material used was mixed with the compositions shown in Tables 2 to 3 to prepare a composition. Using the obtained composition, E-type viscosity, surface tension, moisture permeability, coating area expansion rate, curing rate, flatness, transparency, glass transition temperature, and organic EL evaluation were performed by the evaluation methods shown below. The measurement was performed. The results are shown in Tables 2-3. The abbreviations shown in Table 1 were used for the composition names in Tables 2 and 3. The fluorine atom content shown in Tables 2 to 3 is calculated from the composition and is shown on the basis of the total amount of the composition.

[E-type viscosity η]
The viscosity of the composition was measured using an E-type viscometer (cone plate type: cone angle 1 ° 34', cone rotor radius 24 mm) under the conditions of a temperature of 25 ° C. and a rotation speed of 100 rpm.

[Surface tension γ]
The surface tension of the composition was measured by the pendant drop method using a contact angle meter (DM500 manufactured by Kyowa Interface Science Co., Ltd.) in an atmosphere of 23 ° C.

[Photo-curing conditions]
In the evaluation of the cured physical properties of the composition, the composition was cured under the following light irradiation conditions. The composition is photocured and cured under the condition of an integrated light amount of 1,500 mJ / cm ² at a wavelength of 395 nm by an LED lamp (UV-LED LIGHT SOURCE H-4MLH200-V1 manufactured by HOYA) that emits a wavelength of 395 nm. I got a body.

[Humidity permeability]
A sheet-shaped cured product having a thickness of 0.1 mm was prepared under the above photocuring conditions, and calcium chloride (anhydrous) was used as a hygroscopic agent in accordance with JIS Z0208: 1976 "Humidity Permeability Test Method for Moisture-Proof Packaging Material (Cup Method)". Was measured under the conditions of an atmospheric temperature of 85 ° C. and a relative humidity of 85%.

[Curing rate]
With respect to the composition obtained in each experimental example, the composition was applied to a size of 10 mm × 10 mm on non-alkali glass washed by the above method so as to have a thickness of 10 μm using the above inkjet device. Then, it was cured under the above photocuring conditions in a nitrogen atmosphere having an oxygen concentration of less than 0.1%, and the curing rate was measured by the following procedure.
An infrared spectroscope (Nicolet is5 manufactured by Thermo Scientific Co., Ltd., DTGS detector, resolution 4 cm ^-1 ) was used for the composition after curing and the composition before curing, and infrared light was applied to the measurement sample. The infrared spectroscopic spectrum was measured after incident. In the obtained infrared spectroscopic spectrum, the expansion and contraction vibration peak of the carbon-hydrogen bond of the methylene group observed near 2950 cm ^-1 , which does not cause a peak change before and after curing, is used as the internal standard, and before and after curing of this internal standard. From the peak area and the area before and after curing of the peak near 810 cm ^-1 , which is attributed to the peak of the out-of-plane angle vibration of the carbon-hydrogen bond bonded to the carbon-carbon double bond of (meth) acrylate, the following equation The curing rate was calculated using.
Curing rate (%) = [1- (Ax / Bx) / (Ao / Bo)] x 100
here,
Ao: Represents the peak area before curing near 810 cm ^-1 .
Ax: Represents the peak area after curing near 810 cm ^-1 .
Bo: Represents the peak area before curing near 2950 cm ^-1 .
Bx: Represents the peak area after curing near 2950 cm ^-1 .

〔transparency〕
The composition obtained in each experimental example was formed to a thickness of 10 μm between two 25 mm × 25 mm × 1 mmt (mm thickness) glass plates (non-alkali glass, Corning's Eagle XG), and an LED lamp was used. A cured product was obtained by irradiating with ultraviolet rays having a wavelength of 395 nm so that the irradiation amount was 1500 mJ / cm ² . The obtained cured product was measured for spectral transmittance at 380 nm, 412 nm, and 800 nm with an ultraviolet-visible spectrophotometer (“UV-2550” manufactured by Shimadzu Corporation) to obtain transparency.

〔Glass-transition temperature〕
The composition obtained in each experimental example was sandwiched between PET films using a 1 mm thick silicon sheet as a mold. The composition was cured from above under the photocuring conditions and then further cured from below under the photocuring conditions to prepare a cured product of the composition having a thickness of 1 mm. The prepared cured product was cut into a length of 50 mm and a width of 5 mm with a cutter to obtain a cured product for measuring the glass transition temperature. The obtained cured product is subjected to stress and strain in the tensile direction of 1 Hz in a nitrogen atmosphere by a dynamic viscoelasticity measuring device "DMS210" manufactured by Seiko Denshi Sangyo Co., Ltd., and the temperature rise rate is 2 ° C. per minute. Tan δ was measured while raising the temperature from −150 ° C. to 200 ° C. at the rate of tan δ, and the temperature of the peak top of the tan δ was defined as the glass transition temperature. The peak top of tan δ was set to the maximum value in the region where tan δ was 0.3 or more. When tan δ was 0.3 or less in the region of −150 ° C. to 200 ° C., the peak top of tan δ was set to exceed 200 ° C., and the glass transition temperature was set to exceed 200 ° C. (200 <).

[Expansion rate of coating area]
The composition obtained in each experimental example is placed on a 70 mm × 70 mm × 0.7 mmt substrate (non-alkali glass (Eagle XG manufactured by Corning)) with an inkjet ejection device (MID500B manufactured by Musashi Engineering Co., Ltd., solvent-based head “MID head”). ”) Was used to apply a pattern so as to have a size of 4 mm × 4 mm × 10 μmt. Before use, the non-alkali glass was washed with acetone and isopropanol, respectively, and then with a UV ozone cleaning device UV-208 manufactured by Technovision Co., Ltd. for 5 minutes. Immediately after the pattern was applied, the mixture was left to stand for 5 minutes under the conditions of an atmospheric temperature of 23 ° C. and a relative humidity of 50%, and the flatness after the inkjet application was evaluated by the expansion rate of the application area (see the formula below). It was evaluated that the smaller the expansion ratio of the coated area, the more the shape after coating was maintained, the better the position controllability, and the more preferable.
(Expansion rate of coating area) = ((contact area of the composition in contact with the surface of the substrate 5 minutes after coating the pattern) / (contact area of the composition in contact with the surface of the substrate immediately after coating the pattern)) ) X 100 (%)

[Flatness]
By etching method, 25 μm × 25 μm × 3 μmt dents are aligned on a 70 mm × 70 mm × 0.7 mmt base material (non-alkali glass (Eagle XG manufactured by Corning)) with an interval of 10 μm in the front-back and left-right directions. Made. Before use, the substrate was washed with acetone and isopropanol, respectively, and then with a UV ozone cleaning device UV-208 manufactured by Technovision Co., Ltd. for 5 minutes. Next, a 200 nm SiN film was formed on the substrate provided with the recess by a plasma CVD method. Next, a sealant was applied in a pattern so as to have a size of 50 mm × 50 mm × 10 μmt using an inkjet ejection device (MID500B manufactured by Musashi Engineering Co., Ltd., solvent-based head “MID head”). After the pattern was applied, it was left for 5 minutes under the conditions of a temperature of 23 ° C. and a relative humidity of 50%, and the shape of the sealant coating film was observed. The flatness of the sealant was determined by the following formula. The results are shown in Table 1.
Flatness (%) = (Area of sealant coating after leaving for 5 minutes) / (50 mm x 50 mm)
For example, 50% flatness means that a part of the sealant coated with the pattern was repelled and the SiN film was exposed in half (50%) of the range of 50 mm × 50 mm.

[Organic EL evaluation]

[Manufacturing of organic EL element substrate]
A 30 mm square glass substrate with an ITO electrode (thickness 700 μm) was washed with acetone and isopropanol, respectively. Then, the following compounds are sequentially vapor-deposited into a thin film by a vacuum vapor deposition method, and have a 2 mm square organic EL element composed of an anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode. Obtained a substrate. The structure of each layer is as follows.
・ Anode ITO, anode film thickness 150 nm
-Hole injection layer 4,4', 4 "-tris {2-naphthyl (phenyl) amino} triphenylamine (2-TNATA)
-Hole transport layer N, N'-diphenyl-N, N'-dinaphthylbenzidine (α-NPD)
-Light emitting layer Tris (8-hydroxyquinolinato) aluminum (metal complex material), the film thickness of the light emitting layer is 1000 Å, and the light emitting layer also functions as an electron transport layer.
・ Electron injection layer Lithium fluoride / cathode Aluminum film thickness 150nm

[Manufacturing of organic EL element]
Then, a mask (cover) having an opening of 10 mm × 10 mm was installed so as to cover the organic EL element of 2 mm × 2 mm, and a SiN film was formed by a plasma CVD method. Next, the composition (organic substance film) obtained in each experimental example was applied under a nitrogen atmosphere using the above-mentioned inkjet device to a thickness of 10 μm so as to cover an organic EL element of 2 mm × 2 mm, and the photocuring conditions. After curing this composition, a mask (cover) having an opening of 10 mm × 10 mm is installed so as to cover the entire cured product, and a SiN film is formed by a plasma CVD method to form an organic substance. An EL display element was obtained.

The thickness of the formed SiN (inorganic film) was about 1 μm. Then, using a transparent base material-less double-sided tape of 30 mm × 30 mm × 25 μmt, it was bonded to 30 mm × 30 mm × 0.7 mmt of non-alkali glass (Eagle XG manufactured by Corning Inc.) to prepare an organic EL element (organic EL evaluation). ).

〔initial〕
A voltage of 6 V was applied to the organic EL element immediately after production, and the light emitting state of the organic EL element was visually and microscopically observed, and the diameter of the dark spot was measured.

〔durability〕
The organic EL device immediately after production is exposed for 70 hours under the conditions of 85 ° C. and a relative humidity of 85% by mass, then a voltage of 6 V is applied, and the light emitting state of the organic EL device is visually and microscopically observed to be dark. The diameter of the spot was measured.

The diameter of the dark spot can be regarded as an index for evaluating the degree of penetration of the sealant into the pinholes of the passivation layer and the degree of the moisture in the sealant being discharged as outgas. The diameter of the dark spot was preferably 300 μm or less, more preferably 50 μm or less, and most preferably the absence of the dark spot.

The following was found from the above experimental example.

The composition according to the present embodiment can provide a composition excellent in reliability of an organic EL element, high-precision ejection property by an inkjet, shape retention after application with an inkjet, and excellent low moisture permeability.

Using acyclic alkanediol dimethacrylate having 6 or more carbon atoms as (A) and cyclic monofunctional (meth) acrylate and cyclic bifunctional (meth) acrylate as (B), formulas (I) to (III) can be expressed. When both were satisfied, reliability, inkjet ejection property, shape retention, and low moisture permeability were excellent (Experimental Examples 1 to 3 and 10 to 11).

Furthermore, when (E) is contained, it is also understood that the flatness is improved by lowering the surface free energy of the encapsulant due to the fluorine-containing monomer and making it easier to follow fine irregularities (Experimental example). 4-9).

On the other hand, when an acyclic alkanediol di (meth) acrylate having less than 6 carbon atoms is used as (A), the expansion rate of the coating area is large and the shape after inkjet coating cannot be maintained, that is, the shape retention is improved. There was a problem (Experimental Example 12). When the content of the component (A) exceeds 85 parts by mass and the content of the component (B) is less than 15 parts by mass, the viscosity is low and the formula (III) is not satisfied, and shape retention and reliability are obtained. There was no (Experimental Example 13). When a long-chain alkyl monofunctional acrylate and a cyclic bifunctional methacrylate are used instead of the cyclic monofunctional (meth) acrylate as (B), the viscosity is low and the formula (III) is not satisfied, and reliability and shape retention are achieved. Low moisture permeability was not obtained (Experimental Example 14). Using acyclic alkanediol dimethacrylate having 6 or more carbon atoms as (A) and two types of cyclic (meth) acrylates as (B), the formulas (II) to (III) are satisfied, and the viscosity is 50 mPa · s. In the case of the super case, the low moisture permeability was excellent, but the inkjet ejection could not be performed, and the reliability and shape retention could not be evaluated (Experimental Example 15). When cyclic bifunctional (meth) acrylate was not used as (B), only cyclic monofunctional acrylate was used, and the formulas (I) to (III) were satisfied, the transparency and shape retention were inferior (Experimental Example). 16).

The composition of the present embodiment is excellent in ejection property by high-precision inkjet and flatness after application to the inkjet, has low moisture permeability and transparency, and does not deteriorate the organic EL element. In this embodiment, inkjet coating can be performed in a short time. The composition of the present embodiment is an electronic product, particularly a display component such as an organic EL (for example, a flexible display or an organic EL device used in a wearable product or the like), or an electron such as an image sensor such as CCD or CMOS. It can be suitably applied to adhesion of element packages and the like used for parts and semiconductor parts and the like. In particular, it is most suitable for adhesion for sealing organic EL, and satisfies the characteristics required for an adhesive for an element package such as an organic EL element and a coating agent for an element package.

The above composition is one aspect of the present embodiment, and the encapsulant for an organic EL element, a cured product, an organic EL device, a display, a method for producing them, and the like of the present embodiment also have the same configuration and effect.

Claims (29)

It contains (A) an acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator.
The cyclic monomer (B) contains a cyclic monofunctional (meth) acrylate and a cyclic bifunctional (meth) acrylate.
A sealant for an organic electroluminescence display element that satisfies both the following formulas (I) and (III).
8 mPa ・ s ≦ η ≦ 50 mPa ・ s ・ ・ ・ (I)
γ / 2η <0.9m / s ・ ・ ・ (III)
(In the formula, η represents the viscosity measured by the E-type viscometer at 25 ° C., and γ represents the static surface tension measured by the pendant drop method.) It contains (A) an acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator.
The component (A) and the component (B) are contained in an amount of 10 to 85 parts by mass and the component (B) is contained in an amount of 15 to 90 parts by mass with respect to a total of 100 parts by mass.
The cyclic monomer (B) contains a cyclic monofunctional (meth) acrylate and a cyclic bifunctional (meth) acrylate.
The content ratio of the cyclic monofunctional (meth) acrylate and the cyclic bifunctional (meth) acrylate is a cyclic monofunctional (meth) acrylate in a mass ratio of 100 parts by mass of the total of the cyclic monofunctional (meth) acrylate and the cyclic bifunctional (meth) acrylate. Meta) Acrylate: A sealant for an organic electroluminescence display element having a cyclic bifunctional (meth) acrylate = 10 to 95: 90 to 5 and satisfying the following formulas (I), (II) and (III) together.
8 mPa ・ s ≦ η ≦ 50 mPa ・ s ・ ・ ・ (I)
14 mN / m ≤ γ ≤ 40 mN / m ... (II)
γ / 2η <0.9m / s ・ ・ ・ (III)
(In the formula, η represents the viscosity measured by the E-type viscometer at 25 ° C., and γ represents the static surface tension measured by the pendant drop method.) (B) The encapsulant for an organic electroluminescence display element according to claim 1 or 2, wherein the cyclic monomer contains one or more kinds of alicyclic monomers. The sealant for an organic electroluminescence display element according to any one of claims 1 to 3, which contains a fluorine-containing monomer having a fluorine atom and a (meth) acryloyl group as a component (E). The sealant for an organic electroluminescence display element according to claim 4, wherein the fluorine atom content of the fluorine-containing monomer is 2 to 70% by mass based on the total amount of the fluorine-containing monomer. The fluorine-containing monomer is at least one selected from the group consisting of a compound represented by the formula (E-1), a compound represented by the formula (E-2) and a compound represented by the formula (E-3). The encapsulant for an organic electroluminescence display element according to claim 4 or 5.
Equation (E-1)

[In equation (E-1),
R ¹ represents a hydrogen atom or a methyl group
R ² indicates an alkyl fluoride group or a group in which an oxygen atom is inserted as a part of a carbon-carbon bond and a carbon-hydrogen bond in the alkyl fluoride group. ]
Equation (E-2)

[In equation (E-2),
R ³ represents a hydrogen atom or a methyl group
R ⁴ indicates an alkanediyl fluoride group or a group in which an oxygen atom is inserted as a part of a carbon-carbon bond and a carbon-hydrogen bond in the alkanediyl fluoride group. A plurality of R ^3s may be the same or different from each other. ]
Equation (E-3)

[In formula (E-3),
R ⁵ represents a hydrogen atom or a methyl group
R ⁶ is a single bond, an alkanediyl group, an alkanediyl fluoride group, or a group in which an oxygen atom is inserted as part of a carbon-carbon bond or a carbon-hydrogen bond in an alkanediyl group or an alkanediyl fluoride group. Shows,
Ar ¹ represents an aryl fluoride group. ] The group in which the fluorine-containing monomer consists of a compound represented by the formula (E-1-1), a compound represented by the formula (E-2-1), and a compound represented by the formula (E-3-1). The sealant for an organic electroluminescence display element according to claim 6, which comprises at least one selected from the above.
Equation (E-1-1)

[In the formula (E-1-1), R ¹ represents a hydrogen atom or a methyl group, R ²¹ represents a hydrogen atom or a fluorine atom, and n represents an integer of 1 or more. A plurality of R ^21s may be the same or different from each other. However, at least one of R ²¹ is a fluorine atom. ]
Equation (E-2-1)

[In the formula (E-2-1), R ³ represents a hydrogen atom or a methyl group, R ⁴¹ represents a hydrogen atom or a fluorine atom, and m represents an integer of 1 or more. A plurality of R ^41s may be the same or different from each other. A plurality of R ^3s may be the same or different from each other. However, at least one of R ⁴¹ is a fluorine atom. ]
Equation (E-3-1)

[In formula (E-3-1), R ⁵ represents a hydrogen atom or a methyl group, R ⁶¹ represents a hydrogen atom or a fluorine atom, R ⁶² represents a hydrogen atom or a fluorine atom, and p is an integer of 0 or more. Is shown. A plurality of R ^61s may be the same or different from each other. A plurality of R ^62s may be the same or different from each other. However, at least one of R ⁶² is a fluorine atom. ] Claims 4 to 7 are characterized in that the content of the component (E) is in the range of 0.1 parts by mass to 10 parts by mass with respect to a total of 100 parts by mass of the components (A) and (B). The encapsulant for an organic electroluminescence display element according to any one of the above. The component (E) is 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluoro-1,10-decanedioldi ( It is characterized by containing one or more selected from the group consisting of meta) acrylates, 1H, 1H, 5H-octafluoropentyl (meth) acrylates, and 1H, 1H, 2H, 2H-tridecafluorooctyl (meth) acrylates. The sealant for an organic electroluminescence display element according to any one of claims 4 to 8. The sealant for an organic electroluminescence display element according to any one of claims 1 to 9, wherein the coating agent is applied by an inkjet method. Any one of claims 1 to 10, which does not contain a bifunctional (meth) acrylate oligomer, a bifunctional (meth) acrylate polymer, a polyfunctional (meth) acrylate oligomer, or a polyfunctional (meth) acrylate polymer. A sealant for an organic electroluminescence display element according to. The sealant for an organic electroluminescence display element according to any one of claims 1 to 11, wherein the glass transition temperature of the cured product is 65 ° C. or higher and 120 ° C. or lower. The sealant for an organic electroluminescence display element according to any one of claims 1 to 12, wherein at least one of the components (B) has two or more cyclic structures in the molecule. The sealant for an organic electroluminescence display element according to any one of claims 1 to 13, wherein at least two of the components (B) have two or more cyclic structures in the molecule. The component (B) is ethoxylated-o-phenylphenol (meth) acrylate, m-phenoxybenzyl (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, and ethoxylated bisphenol A represented by the following structural formula. The encapsulant for an organic electroluminescence display element according to any one of claims 1 to 14, which comprises one or more of the group consisting of di (meth) acrylate.

(R in the formula is independently a hydrogen atom or a methyl group. With respect to m and n in the formula, m + n = 2 to 10) The sealant for an organic electroluminescence display element according to any one of claims 1 to 15, wherein the component (A) is an alkanediol di (meth) acrylate having 12 or less carbon atoms. One or more of the group (A) consisting of 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, and 1,12-dodecanediol di (meth) acrylate. The sealant for an organic electroluminescence display element according to any one of claims 1 to 16, which comprises. The encapsulant for an organic electroluminescence display device according to any one of claims 1 to 17, wherein the component (C) contains 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. The sealant for an organic electroluminescence display element according to any one of claims 1 to 18, wherein the content of the component (C) is 0.5 to 4 parts by mass. The sealant for an organic electroluminescence display element according to any one of claims 1 to 19, further comprising (D) an antioxidant. The sealant for an organic electroluminescence display element according to claim 20, wherein the component (D) is a hindered phenolic antioxidant. The encapsulant for an organic electroluminescence display element according to any one of claims 20 to 21, which contains two or more kinds of the component (D). The sealant for an organic electroluminescence display element according to any one of claims 1 to 22, which is cured at a wavelength of 395 nm or more and 500 nm or less. The sealant for an organic electroluminescence display element according to claim 23, which is cured by an LED lamp having a diameter of 395 nm. A cured product obtained by curing the sealant for an organic electroluminescence display element according to any one of claims 1 to 24. An organic EL device including the cured product according to claim 25. A display comprising the cured product according to claim 25. A flexible display comprising the cured product of claim 25. A flexible organic EL device comprising the cured product according to claim 25.