TWI751205B - Sealant for organic electroluminescence display element - Google Patents

Abstract

A composition comprising (A) 3 or more functional acyclic polyfunctional (meth)acrylates, (B) acyclic 2-functional (meth)acrylates, and (C) monofunctional (meth)acrylates , and (D) a photopolymerization initiator, wherein the composition contains (A) 3 to 70 parts by mass, (B) 15 parts by mass in a total of (A), (B) and (C) of 100 parts by mass ~95 parts by mass, and (C) 2 to 40 parts by mass. This composition can be used as a sealant for organic electroluminescence display elements.

Description

Sealant for organic electroluminescent display elements

The present invention relates to a composition. The present invention relates to, for example, a composition that can be used in a sealant for organic electroluminescence (EL) display elements.

An organic electroluminescence (EL) element is attracting attention as an element body capable of emitting light with high brightness. However, there is a problem in that it is deteriorated by moisture and the light-emitting characteristic is deteriorated.

In order to solve these problems, techniques for sealing organic EL elements and preventing deterioration due to moisture are being studied. For example, a method of sealing with a sealing material made of frit glass is exemplified (refer to Patent Document 1).

The document proposes an organic electroluminescence display element, characterized in that the sealing layer is a laminate in which at least a barrier layer, a resin layer, and a barrier layer are formed in this order (refer to Patent Document 2); and an organic EL device, characterized in that comprising: a sealing layer in which an inorganic film and an organic film for sealing the organic EL element are alternately laminated, and a sealing layer arranged to be in close contact with the uppermost organic film of the foregoing sealing layer to cover the entire upper surface of the uppermost organic film Glass substrate (refer to Patent Document 3).

As a resin composition for sealing an organic EL element, the document proposes a sealant for an organic electroluminescence display element, which contains a cyclic ether compound, a cationic polymerization initiator, and a polyfunctional vinyl ether compound (refer to Patent Document 4); and A cationically polymerizable resin composition containing a cationically polymerizable compound, a cationic photopolymerization initiator, or a cationic thermal polymerization initiator (refer to Patent Document 5). As a resin composition for sealing an organic EL element, a (meth)acrylic resin composition has been proposed in the literature (Patent Documents 6 to 9).

[Prior Art Literature]

[Patent Literature]

[Patent Literature]

Patent Document 1: Japanese Patent Application Laid-Open No. 10-74583

Patent Document 2: Japanese Patent Laid-Open No. 2001-307873

Patent Document 3: Japanese Patent Laid-Open No. 2009-37812

Patent Document 4: Japanese Patent Laid-Open No. 2014-225380

Patent Document 5: Japanese Patent Laid-Open No. 2012-190612

Patent Document 6: Japanese Patent Laid-Open No. 2014-229496

Patent Document 7: Japanese Patent Laid-Open No. 2014-196387

Patent Document 8: Japanese Patent Laid-Open No. 2014-193970

Patent Document 9: Japanese Patent Laid-Open No. 2014-193971

However, the conventional techniques described in the above-mentioned documents have room for improvement in the following points.

In Patent Document 1, when mass-producing the organic EL element, a method of sandwiching an organic EL element with a substrate having low moisture permeability such as glass, and sealing the outer edge portion thereof is adopted. In this case, since the structure becomes a hollow sealing structure, the penetration of moisture into the inside of the hollow sealing structure cannot be prevented, and there is a problem of causing deterioration of the organic EL element.

In Patent Documents 2 to 3, there is a problem that the thickness of the organic film is 3 μm or less because the organic film is formed by deposition. When the thickness of the organic film is 3 μm or less, there is a problem that not only does not completely cover the particles generated when the element is formed, but also it is difficult to coat the inorganic film while maintaining flatness.

In Patent Document 4, a sealant using an epoxy-based material is proposed, but since this material requires heating for curing, there are problems in damage to the organic EL element and in terms of productivity. In Patent Document 5, a photocurable sealant using an epoxy-based material has been proposed, but since this material is cured by transmitting UV light, there are problems in that the organic EL element is damaged by the transmitted UV light, and there are problems in terms of yield . Patent Documents 6 to 9 do not describe the use of (A) tri- or more functional acyclic polyfunctional (meth)acrylate and (B) acyclic bifunctional (meth)acrylate in combination in a specific amount. Patent Documents 6 to 9 do not describe coating properties either.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof, for example, is to provide a composition having excellent coatability and low moisture permeability when used for sealing an organic EL element.

Embodiments of the present invention can be provided as follows.

<1> A composition comprising (A) tri- or more functional acyclic polyfunctional (meth)acrylate, (B) acyclic bifunctional (meth)acrylate, (C) monofunctional (meth)acrylate ) Acrylate, and (D) a photopolymerization initiator, wherein the composition contains (A) 3 to 70 parts by mass, (A), (B) and (C) in a total of 100 parts by mass. B) 15-95 mass parts, and (C) 2-40 mass parts.

<2> A composition comprising (A) tri- or more functional acyclic polyfunctional (meth)acrylate, (B) acyclic bifunctional (meth)acrylate, (C) monofunctional (meth)acrylate ) Acrylate, and (D) a photopolymerization initiator, wherein the composition contains (A) 3 to 10 parts by mass, (A), (B) and (C) in a total of 100 parts by mass B) 85-95 mass parts, and (C) 2-10 mass parts.

<3> The composition according to <1> or <2>, wherein 0.05 to 6 parts by mass of (D) is included in a total of 100 parts by mass of (A), (B) and (C).

<4> The composition according to any one of <1> to <3>, wherein the viscosity measured with an E-type viscometer at 25°C is 2 mPa·s or more and 50 mPa·s or less.

<5> The composition according to any one of <1> to <4>, which does not contain a polyfunctional (meth)acrylate oligomer/polymer.

<6> The composition according to any one of <1> to <5>, wherein the glass transition temperature of the cured product obtained from the composition is 200° C. or higher.

<7> The composition according to any one of <1> to <6>, wherein (A) is trimethylolpropane tri(meth)acrylate.

<8> The composition according to any one of <1> to <7>, wherein (B) is an alkylene glycol di(meth)acrylate having 6 or more carbon atoms.

<9> The composition according to any one of <1> to <8>, wherein (B) is an alkylene glycol di(meth)acrylate having 12 or less carbon atoms.

<10> The composition according to any one of <1> to <9>, wherein (B) is composed of 1,9-nonanediol di(meth)acrylate, di(meth)acrylic acid -1,10-decanediol ester, and 1,12-dodecanediol di(meth)acrylate in the group which consists of 1 or more types.

<11> The composition according to any one of <1> to <10>, wherein (B) contains an acyclic bifunctional methacrylate and an acyclic bifunctional acrylate.

<12> The composition according to any one of <1> to <11>, wherein (C) is an alkyl (meth)acrylate having 8 or more carbon atoms.

<13> The composition according to any one of <1> to <11>, wherein (C) is lauryl (meth)acrylate.

<14> The composition according to any one of <1> to <11>, wherein (C) is a (meth)acrylate having an alicyclic hydrocarbon group.

<15> The composition according to any one of <1> to <11>, wherein (C) contains a monofunctional methacrylate and a monofunctional acrylate.

<16> The composition according to any one of <1> to <15>, wherein (D) is an acylphosphine oxide derivative.

<17> The composition according to any one of <1> to <16>, wherein the composition is a sealant for an organic electroluminescence display element.

<18> A covering agent consisting of the composition described in any one of <1> to <17>.

<19> An adhesive composed of the composition according to any one of <1> to <17>.

<20> A cured product cured by the composition of any one of <1> to <17>.

<21> A covering body covered with the composition of any one of <1> to <17>.

<22> A joined body joined by the composition of any one of <1> to <17>.

<23> A curing method of the composition according to any one of <1> to <17>, which is curing at a wavelength of 380 nm or more and 500 nm or less.

<24> A curing method of the composition according to any one of <1> to <17>, which is curing using an LED lamp having an emission peak wavelength of 395 nm.

<25> A coating method of the composition according to any one of <1> to <17>, which is coating using an inkjet method.

<26> An organic EL device comprising the cured body described in <20>.

<27> A display comprising the cured body described in <20>.

<28> A composition comprising (A) tri- or more functional acyclic polyfunctional (meth)acrylate, (B) acyclic bifunctional (meth)acrylate, (C) monofunctional (meth)acrylate ) Acrylate, and (D) a photopolymerization initiator, wherein the composition contains (A) 1 to 70 parts by mass, (A), (B) and (C) in a total of 100 parts by mass. B) 15-98 mass parts, and (C) 1-40 mass parts.

<29> A composition comprising (A) tri- or more functional acyclic polyfunctional (meth)acrylate, (B) acyclic bifunctional (meth)acrylate, (C) monofunctional (meth)acrylate ) Acrylate, and (D) a photopolymerization initiator, wherein the composition contains (A) 1 to 10 parts by mass, ( B) 85-98 mass parts, and (C) 1-10 mass parts.

The composition according to the embodiment of the present invention has the effect of being excellent in coatability and low moisture permeability.

Embodiments of the present invention will be described below. In this specification, unless otherwise stated, the numerical range includes the upper limit and the lower limit thereof.

Hereinafter, a top emission type organic EL device in which light is irradiated 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 includes the following structures formed in sequence: an organic EL element, which is an element formed by sequentially laminating an anode, an organic EL layer containing a light-emitting layer, and a cathode on a substrate; a sealing layer, which covers the organic EL layer. The whole EL element is composed of a laminate of an inorganic film and an organic film; and a sealing substrate is provided on the sealing layer.

As the substrate, various substrates such as glass substrates, silicon substrates, and plastic substrates can be used. Among them, preferably one or more of the group consisting of a glass substrate and a plastic substrate, more preferably a glass substrate.

Examples of plastics used for plastic substrates include polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, polyoxadiazole, aromatic polyamide, Polybenzimidazole, polybenzobisthiazole, polybenzoxazole, polythiazole, polypara-phenylenevinylene, polymethylmethacrylate Ester, polystyrene, polycarbonate, polycycloolefin, polyacryl, etc. Among them, from the viewpoint of being excellent in low moisture permeability, low oxygen permeability, and heat resistance, polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate are preferred. One or more selected from the group consisting of diester, polyoxadiazole, aromatic polyamide, polybenzimidazole, polybenzodithiazole, polybenzoxazole, polythiazole, and poly(p-phenylene vinylene), From the viewpoint of high transmittance of energy rays such as ultraviolet light or visible light, polyimide, polyetherimide, polyethylene terephthalate, and polyethylene naphthalate are more preferred. more than one of the groups.

As the anode, a conductive metal oxide film, a semitransparent metal thin film, or the like having a relatively large work function (preferably a material having a work function larger than 4.0 eV) is generally used. Substances contained in the anode material include, for example, metal oxides such as indium tin oxide (Indium Tin Oxide, hereinafter referred to as ITO) and tin oxide; gold (Au), platinum (Pt), silver (Ag), copper ( Metals such as Cu) or alloys containing at least one of them; and organic transparent conductive films such as polyaniline or its derivatives, polythiophene or its derivatives, and the like. Among them, ITO is preferable. If desired, the anode may be formed of a layer structure of two or more layers. The film thickness of the anode can be appropriately selected in consideration of electrical conductivity (in the case of bottom emission type, plus light transmittance). 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 methods for producing the anode include vacuum deposition, sputtering, ion plating, and electroplating. In the case of the top emission type, a reflective film for reflecting light irradiated on the substrate side may be provided under the anode.

The organic EL layer includes at least a light-emitting layer composed of an organic substance. The light-emitting layer contains a light-emitting material. Examples of the light-emitting material include organic substances (low-molecular compounds or high-molecular compounds) that emit fluorescence or phosphorescence. The light-emitting layer may further contain a dopant material. Examples of organic substances include dye-based materials, metal complex-based materials, and polymer materials. The dopant material is a material that is doped into an organic substance for the purpose of improving the luminous efficiency of the organic substance, changing the emission wavelength, and the like. The thickness of the light-emitting layer composed of these organics and doping materials doped as needed is usually 20 to 2,000 Å.

(pigment material)

Examples of pigment-based materials include cyclopendamine derivatives, tetraphenyl butadiene derivatives, triphenylamine derivatives, oxadiazole derivatives, and pyrazoloquinoline. Derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, pyrrole derivatives, thiophene ring compounds, pyridine ring compounds, perinone derivatives, perylene derivatives compounds, oligothiophene derivatives, trifumanylamine derivatives, oxadiazole dimers, and pyrazoline dimers, etc.

(Metal complex material)

Examples of metal complex-based materials include iridium complexes, platinum complexes, and other metal complexes that emit light from triplet excited states, aluminum quinolinol complexes, benzoquinoline beryllium ( benzoquinolinol beryllium complex, benzoxazolyl zinc complex, benzothiazole zinc complex, azomethyl zinc complex, porphyrin Zinc) complexes, europium complexes and other metal complexes. Examples of metal complexes include rare earth metals such as abium (Tb), europium (Eu), and dysprosium (Dy), aluminum (Al), zinc (Zn), and beryllium (Be), and the like in the central metal. The ligand has metal complexes such as oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, and quinoline structures. Among them, a metal complex having aluminum (Al) in the central metal and a quinoline structure or the like in the ligand is preferable. Among the metal complexes in which the central metal has aluminum (Al) and the ligand has a quinoline structure, etc., tris(8-hydroxyquinoline)aluminum is preferable.

(Polymer Materials)

Examples of polymer materials include polypara-phenylene derivatives, polythiophene derivatives, polypara-phenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, Polyvinylcarbazole (polyvinylcarbazole) derivatives, and those obtained by polymerizing the above-mentioned dye materials and metal complex-based light-emitting materials, and the like.

Among the above-mentioned light-emitting materials, the materials that emit blue light include stilbene derivatives, oxadiazole derivatives, polyvinylcarbazole derivatives, polyparaphenylene derivatives, polyphenylene derivatives, and derivatives of these derivatives. polymers, etc. Among them, polymer materials are preferred. Among the polymer materials, one or more of the group consisting of polyvinylcarbazole derivatives, polyparaphenylene derivatives and polyphenylene derivatives are preferred.

Examples of materials that emit green light include quinacridone derivatives, coumarin derivatives, polyparaphenylene derivatives, polyphenylene derivatives, and polymers of these derivatives. Among them, polymer materials are preferred. Among the polymer materials, preferably one or more of the group consisting of polyparaphenylene vinylene derivatives and polyphenylene derivatives.

Examples of materials that emit red light include coumarin derivatives, thiophene ring compounds, polyparaphenylene derivatives, polythiophene derivatives, polyphenylene derivatives, and polymers of these derivatives. Among them, polymer materials are preferred. Among the polymer materials, one or more of the group consisting of polyparaphenylene derivatives, polythiophene derivatives, and polyphenylene derivatives are preferred.

(doping material)

Examples of doping materials include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squarylium derivatives, porphyrin derivatives, styryl derivatives Pigments, tetracene derivatives, pyrazolone derivatives, decacyclene, and phenoxazone, etc. 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, the layer disposed between the light-emitting layer and the anode is, for example, a hole-injection layer that improves the efficiency of hole injection from the anode, or a hole-transport layer that improves the efficiency of hole injection from the anode, the hole-injection layer, or a hole-transport layer near the anode to the light-emitting layer. Hole transport layer for hole injection efficiency, etc. Examples of the layer provided between the light-emitting layer and the cathode include an electron injection layer that improves the efficiency of electron injection from the cathode, and an electron transport layer that has a function of improving electron injection from the cathode, the electron injection layer, or the electron transport layer close to the cathode. .

(hole injection layer)

Examples of materials for forming the hole injection layer include aniline-based, starburst amine-based, phthalocyanin-based, vanadium oxide, molybdenum oxide, ruthenium oxide, oxides such as aluminum oxide, amorphous carbon, polyaniline, Polythiophene derivatives, etc. Among them, phthalocyanin-based ones are preferred.

(hole transport layer)

The materials constituting the hole transport layer include polyvinylcarbazole or its derivatives, polysilane or its derivatives, polysiloxane derivatives with aromatic amines on the side chain or main chain, pyrazoline derivatives, aromatic Amine derivatives, stilbene derivatives, triphenyldiamine derivatives, benzidine derivatives, polyaniline or its derivatives, polythiophene or its derivatives, polyarylamine or its derivatives, polypyrrole or its derivatives Derivatives, poly(p-phenylene vinylene) or its derivatives, poly(2,5-thiophene vinylene) or its derivatives, and the like. Among them, benzidine derivatives are preferred.

When these hole injection layers or hole transport layers have a function of preventing electron transport, these hole transport layers and hole injection layers can be called electron blocking layers.

(electron transport layer)

Examples of materials constituting the electron transport layer include oxadiazole derivatives, anthraquinodimethane or its derivatives, benzoquinone or its derivatives, naphthoquinone or its derivatives, anthraquinone or its derivatives, and tetracyananthracene. quinodimethane (tetracyanoanthraquinodimethane) or its derivatives, fenone derivatives, diphenyl dicyanoethylene or its derivatives, diphenoquinone derivatives, 8-hydroxyquinoline or its derivatives, polyquinoline or its derivatives , polyquinoxaline or its derivatives, and polytetramethylene or its derivatives. Examples of derivatives include metal complexes and the like. Among them, 8-hydroxyquinoline or a derivative thereof is preferred. Among 8-hydroxyquinoline or its derivatives, tris(8-hydroxyquinoline)aluminum is preferable from the viewpoint that it can also be used as an organic substance emitting fluorescence or phosphorescence in the light-emitting layer.

(electron injection layer)

The electron injection layer corresponds to the type of the light-emitting layer, such as an electron injection layer consisting of a single-layer structure of a calcium (Ca) layer, or an electron injection layer consisting of the following single-layer structure or laminate structure, etc., wherein the single-layer structure is composed of periodic Table IA Group and IIA group metals, and the work function of 1.5 ~ 3.0eV metal and metal oxides, halides and carbonates in the group formed by one or more kinds of layers formed; the layered structure is composed of periodic Table IA Group and Group IIA metals, and the work function of 1.5 ~ 3.0eV metal and its metal oxides, halides and carbonates of one or more of the group formed by the layer formed and the Ca layer. The work function is 1.5 to 3.0 eV, and the metals in Periodic Table IA or their oxides, halides, and carbonates include lithium (Li), lithium fluoride, sodium oxide, lithium oxide, and lithium carbonate. The work function is 1.5 to 3.0 eV, and the metals of Group IIA of the periodic table or their oxides, halides and carbonates are exemplified by strontium (Sr), magnesium oxide, magnesium fluoride, strontium fluoride, barium fluoride, strontium oxide, and magnesium carbonate. Among them, lithium fluoride is preferred.

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

The cathode is preferably a material having a relatively small work function (preferably a material having a work function smaller than 4.0 eV), and a transparent or semitransparent material that can easily inject electrons into the light-emitting layer. Examples of substances contained in the cathode material include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), beryllium (Be), magnesium (Mg), calcium (Ca), strontium ( Sr), Barium (Ba), Aluminum (Al), Scandium (Sc), Vanadium (V), Zinc (Zn), Yttrium (Y), Indium (In), Cerium (Ce), Samarium (Sm), Europium ( Metals such as Eu), titanium (Tb), and ytterbium (Yb), or an alloy composed of two or more of the above metals, or a combination of one or more of the above metals with gold (Au), silver (Ag), platinum (Pt), copper (Cu), chromium (Cr), manganese (Mn), titanium (Ti), cobalt (Co), nickel (Ni), tungsten (W), and tin (Sn) at least one alloys, or graphite or graphite interlayer compounds, or metal oxides of ITO, tin oxide, etc.

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, and alloys thereof, and laminated structures of metals such as Al, Ag, and Cr. Among them, Al is preferred. The film thickness of the cathode can be appropriately selected in consideration of 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 deposition method, a sputtering method, a lamination method in which a metal thin film is bonded by thermocompression, and the like.

The layers provided between these light-emitting layers and the anode, and between the light-emitting layer and the cathode can be appropriately selected according to the performance required for the manufactured organic EL device. For example, the structure of the organic EL element used in this embodiment may have any of the following (i) to (xv) layer structures.

(i) Anode/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) Anode/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

(Here, "/" indicates that each layer is adjacent to the stacked layer. The same below.)

The sealing layer is provided in order to prevent gas such as water vapor and oxygen from coming into contact with the organic EL element, and to seal the organic EL element through a layer having a high barrier property to the gas. This sealing layer forms an inorganic film and an organic film alternately from below. The inorganic/organic layered body may be repeatedly formed twice or more.

The inorganic film of the inorganic/organic laminate is a film provided to prevent the organic EL element from being exposed to gases such as water vapor or oxygen present in the environment where 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 single-layer films such as SiN films, SiO films, SiON films, Al ₂ O ₃ films, and AlN films, and laminate films thereof.

The organic film of the inorganic/organic laminate is provided to cover defects such as pinholes formed on the inorganic film and to provide surface flatness. The organic film is formed in a region narrower than the region where the inorganic film is formed. This is because when the organic film is formed in a region as large or wider as the inorganic film, the organic film is degraded in the exposed region. However, the uppermost organic film formed in the uppermost layer of the entire sealing layer is formed in approximately the same region as the formation region of the inorganic film. Then, the upper surface of the sealing layer is formed for planarization. As the organic film, a composition having a good adhesion function with respect to the adhesion performance of the inorganic film is used.

The object of this embodiment is to provide, for example, a sealant for an organic electroluminescence display element suitable for forming an inkjet coating capable of coating with a film thickness of 3 μm or more and having excellent flatness in a short time, through inkjet coating. The above-mentioned organic film is excellent in the ejection properties and flatness after inkjet coating, as well as in the barrier properties against water vapor and the like (hereinafter, also referred to as "low moisture permeability"). When the coating method by the ink jet method is used, the organic film can be formed at a high speed and uniformly.

The composition of this embodiment contains (A) tri- or higher functional acyclic polyfunctional (meth)acrylate, (B) acyclic bifunctional (meth)acrylate, (C) monofunctional (meth)acrylate ) acrylate, and (D) a photopolymerization initiator. (Meth)acrylate refers to a compound having a (meth)acryloyl group. Among the compounds having a (meth)acryloyl group, a compound having a (meth)acryloyloxy group is preferable. The polyfunctional (meth)acrylate refers to a compound having two or more (meth)acryloyl groups. Trifunctional (meth)acrylate refers to a compound having three (meth)acryloyl groups. A bifunctional (meth)acrylate refers to a compound having two (meth)acryloyl groups. A monofunctional (meth)acrylate refers to a compound having one (meth)acryloyl group. In the composition of the present embodiment, the content of the (meth)acrylate is preferably 70 parts by mass or more, more preferably 80 parts by mass or more, and most preferably 90 parts by mass or more in 100 parts by mass of the composition , and the optimum amount is 95 parts by mass or more. In the (meth)acrylate of this embodiment, the total content of (A), (B), and (C) is preferably 80 parts by mass or more in 100 parts by mass of the (meth)acrylate, More preferably, it is 90 parts by mass or more, most preferably 95 parts by mass or more, and most preferably 100 parts by mass.

(A) Tri- or higher-functional acyclic polyfunctional (meth)acrylate is preferably an acyclic, tri- or higher-functional multifunctional (meth)acrylate monomer (hereinafter, (meth)acrylic acid) Ester monomers are also known as (meth)acrylates). (A) As the tri- or more functional acyclic polyfunctional (meth)acrylate monomer, the acyclic polyfunctional (meth)acrylic acid represented by the formula (1), (2) or (3) is preferred ester.

(in the formula, R ^{1 is} independently represented as a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group represented by the formula (4), and at least 3 R ¹ in the formulas (1) to (3) are represented by In the group represented by the formula (4), R ² represents a hydrogen atom or an alkyl group having 1 or more carbon atoms, R ³ independently represents a hydrogen atom or a methyl group, and m is an integer of 0 to 10).

The acyclic polyfunctional (meth)acrylate represented by the formula (1), (2) or (3) is exemplified by trimethylolpropane tri(meth)acrylate, ethoxylated tri(methyl) Trimethylolpropane acrylate, propoxylated trimethylolpropane tri(meth)acrylate, and neotaerythritol tri(meth)acrylate, etc. Examples of (meth)acrylate monomers with tetrafunctional or higher functions include dimethylolpropane tetra(meth)acrylate, neotaerythritol tetra(meth)acrylate, and neotaerythritol ethyl tetra(meth)acrylate. Oxyester, penta(meth)acrylate dipeutaerythritol, and hexa(meth)acrylate dipeutaerythritol, etc. Among them, trimethylolpropane tri(meth)acrylate is preferred from the viewpoint of having a large effect on low moisture permeability, dischargeability through inkjet, and flatness after inkjet coating.

(A) The content of the trifunctional or more acyclic polyfunctional (meth)acrylate is preferably 1 to 70 parts by mass relative to 100 parts by mass of the total of (A), (B), and (C), More preferably, it is 3-70 mass parts. When the content of (A) is less than 1 part by mass, the performance is inferior from the viewpoint of low moisture permeability, and when it exceeds 70 parts by mass, the viscosity and surface tension of the composition become too high, resulting in a flat surface after inkjet coating. Decreased sex. From the viewpoint of achieving both low moisture permeability and flatness after inkjet coating, it is preferably 7 to 60 parts by mass, more preferably 9 to 55 parts by mass. Moreover, when it is used exclusively for flatness and low curing rate after inkjet coating, it is preferably in the range of 1 to 10 parts by mass, more preferably in the range of 3 to 10 parts by mass.

As (B) acyclic bifunctional (meth)acrylate, an acyclic and bifunctional polyfunctional (meth)acrylate monomer is preferable. (B) Acyclic bifunctional (meth)acrylate monomers are preferably two from the viewpoint of having a large effect on low moisture permeability, dischargeability through inkjet, and flatness after inkjet coating Alkylene glycol (meth)acrylate. Among the alkanediol di(meth)acrylates, di(meth)acrylate-α,ω-linear alkanediol is preferred. The carbon number of the alkane is preferably 6 or more. The number of carbon atoms of the alkane is preferably 12 or less. Among di(meth)acrylic acid-α,ω-straight-chain alkanediol esters, it is preferably composed of di(meth)acrylic acid-1,6-hexanediol, di(meth)acrylic acid-1,9 - at least one of the group consisting of nonanediol, 1,10-decanediol di(meth)acrylate, and 1,12-dodecanediol di(meth)acrylate, More preferably, it is composed of 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and 1,12-dodecanedi(meth)acrylate One or more of the group consisting of alkanediol esters.

The content of (B) acyclic bifunctional (meth)acrylate is preferably 15 to 98 parts by mass, more preferably 15 parts by mass relative to 100 parts by mass of the total of (A), (B), and (C). ~95 parts by mass, the optimum content is 20-95 parts by mass. When the content of (B) is less than 15 parts by mass, the performance is inferior from the viewpoint of low moisture permeability, and when it exceeds 98 parts by mass, the surface tension becomes too high and the flatness after inkjet coating decreases. From the viewpoint of achieving both low moisture permeability and flatness after inkjet coating, it is preferably 25 to 75 parts by mass, more preferably 40 to 72 parts by mass. On the other hand, when it is used exclusively for flatness and low curing rate after inkjet coating, it is preferably in the range of 85 to 98 parts by mass, more preferably in the range of 85 to 95 parts by mass.

(B) Acyclic bifunctional (meth)acrylate preferably contains acyclic bifunctional methacrylate and acyclic bifunctional acrylate. Acyclic bifunctional methacrylate is very effective from the viewpoint of low moisture permeability. Acyclic bifunctional acrylates have a great effect on flatness after inkjet coating. From the viewpoint of achieving both low moisture permeability and flatness after inkjet coating, the content ratio of the acyclic bifunctional methacrylate and the acyclic bifunctional acrylate is In the total of 100 parts by mass of acrylate and acyclic bifunctional acrylate, in terms of mass ratio, preferably acyclic bifunctional methacrylate:acyclic bifunctional acrylate=10~90:90~10, Preferably, it is 25~75: 75~25, and the best is 40~60: 60~40.

As (C) monofunctional (meth)acrylate, a monofunctional (meth)acrylate monomer is preferable. The (C) monofunctional (meth)acrylate monomer is preferably one or more of the group consisting of an alkyl (meth)acrylate and an alkyl (meth)acrylate having an alicyclic hydrocarbon group.

Among the (C) monofunctional (meth)acrylate monomers, alkyl (meth)acrylates are preferred from the viewpoint of having a large effect on discharge properties through inkjet and flatness after inkjet coating. ester. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, and 2-ethyl (meth)acrylate. methylhexyl, isooctyl (meth)acrylate, isononyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and the like. Among the alkyl (meth)acrylates, alkyl (meth)acrylates having an alkyl group of 8 or more carbon atoms are preferred. Among the alkyl (meth)acrylates, alkyl (meth)acrylates having an alkyl group of 16 or less carbon atoms are preferred. Among the alkyl (meth)acrylates having an alkyl carbon number of 8 or more and 16 or less, lauryl (meth)acrylate is preferred. Among the alkyl groups of the alkyl (meth)acrylate, an unsubstituted saturated hydrocarbon group is preferred. Among the saturated hydrocarbon groups, chain compounds are preferred.

Among the monofunctional (meth)acrylate monomers (C), from the viewpoint of low moisture permeability, (meth)acrylates having an alicyclic hydrocarbon group are preferred. The alicyclic hydrocarbon group is exemplified by a group having a dicyclopentadiene skeleton such as a dicyclopentyl group or a dicyclopentenyl group, a cyclohexyl group, an isocamphenyl group, a cyclododecatrienyl group, a norbornyl group, and adamantyl. groups such as alkyl groups. Among them, a group having a dicyclopentadiene skeleton is preferred. Examples of the (meth)acrylate having an alicyclic hydrocarbon group include cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, and (meth)acrylic acid. Dicyclopentenyl, (meth)acrylic acid dicyclopentenyloxyethyl, (meth)acrylic acid isobornyl, and methoxylated (meth)acrylic acid cyclododecatrienyl and the like. Among the (meth)acrylates having a dicyclopentadiene skeleton, preferred are dicyclopentyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, and bicyclic (meth)acrylate. One or more of the group consisting of pentenyl ester and dicyclopentenyloxyethyl (meth)acrylate, more preferably dicyclopentenyloxyethyl (meth)acrylate and dicyclopentyloxyethyl One or more of the group consisting of ethyl (meth)acrylate, preferably dicyclopentenoxyethyl (meth)acrylate. Among the alicyclic hydrocarbon groups, unsubstituted ones are preferred.

The content of the (C) monofunctional (meth)acrylate is preferably 1 to 40 parts by mass, more preferably 2 to 40 parts by mass with respect to 100 parts by mass of the total of (A), (B), and (C). share. When the content of (C) is less than 1 part by mass, the surface tension becomes too high and the flatness after inkjet coating is lowered, and when it exceeds 40 parts by mass, the performance is inferior from the viewpoint of low moisture permeability. From the viewpoint of having both flatness and low moisture permeability after inkjet coating, it is preferably 1 to 30 parts by mass, more preferably 5 to 30 parts by mass, most preferably 7 to 20 parts by mass, and most preferably Within the range of 7 to 10 parts by mass.

The (C) monofunctional (meth)acrylate preferably contains a monofunctional methacrylate and a monofunctional acrylate. The monofunctional methacrylate is very effective from the viewpoint of low moisture permeability. The monofunctional acrylate has a great effect on the flatness after inkjet coating. From the viewpoint of achieving both low moisture permeability and flatness after inkjet coating, the content ratio of the monofunctional methacrylate to the monofunctional acrylate is the sum of the monofunctional methacrylate and the monofunctional acrylate In 100 parts by mass, in terms of mass ratio, preferably monofunctional methacrylate:monofunctional acrylate=5~95:95~5, preferably 25~75:75~25, and most preferably 40~60: 60~40.

In the composition of the present embodiment, (meth)acrylate is preferably a monomer from the viewpoint of ejectability of inkjet. (A), (B), and (C) are particularly preferably monomers. The molecular weight of the monomer is preferably 1,000 or less. From the viewpoint of ejectability of inkjet, the content of the polyfunctional (meth)acrylate oligomer/polymer is preferably 3 parts by mass or less, more preferably 1 part by mass or less, and most preferably 100 parts by mass of the composition. is not included. The polyfunctional (meth)acrylate oligomers/polymers are preferably composed of polyfunctional (meth)acrylate oligomers, polyfunctional (meth)acrylate polymers, and polyfunctional (meth)acrylates One or more of the group consisting of mixtures of oligomers and polyfunctional (meth)acrylate polymers.

(D) The photopolymerization initiator is an agent used to sensitize and accelerate the photocuring of the resin composition through active light rays of visible light or ultraviolet light. Examples of photopolymerization initiators include benzophenone and its derivatives, benzophenone and its derivatives, allium quinone and its derivatives, benzoin, benzoin methyl ether, benzoin ether ( Benzoin derivatives such as benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, and benzil dimethyl ketal, diethoxy Acetophenone, acetophenone derivatives such as 4-tert-butyltrichloroacetophenone, 2-dimethylaminoethyl benzoate, p-dimethylaminoethyl benzoate, diphenyl disulfide, Thioxanthone and its derivatives, camphorquinone, 7,7-dimethyl-2,3-dioxabicyclo[2.2.1]heptane-1-carboxylic acid, 7,7-dimethyl-2 ,3-dioxabicyclo[2.2.1]heptane-1-carboxy-2-bromoethyl ester, 7,7-dimethyl-2,3-dioxabicyclo[2.2.1]heptane -1-carboxy-2-methyl ester, and camphorquinone derivatives such as 7,7-dimethyl-2,3-dioxabicyclo[2.2.1]heptane-1-acyl chloride, 2-methyl Base-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinobenzene α-aminophenalkyl ketone derivatives such as)-butanone-1, benzyldiphenylphosphine oxide, 2,4,6-trimethylbenzyl-diphenylphosphine oxide, benzene Carbyldiethoxyphosphine oxide, 2,4,6-trimethylbenzyldimethoxyphenylphosphine oxide, 2,4,6-trimethylbenzyldiethoxybenzene phenylphosphine oxide, and bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide derivatives, such as bis(2,4,6-trimethylbenzyl)-phenylphosphine oxide, phenyl-glyoxylate methyl ester, oxy-phenyl- Acetate 2-[2-oxa-2-phenyl-acetoxy-ethoxy]-ethyl ester, and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester, etc. . The photopolymerization initiators may be used in combination of one or more. Among them, an acylphosphine oxide derivative is preferable from the viewpoint that it can be cured using only visible light of 390 nm or more and can be cured without causing damage to the organic electroluminescence display element. Among the acylphosphine oxide derivatives, 2,4,6-trimethylbenzene is the most preferable from the viewpoint that the transmittance of visible light does not decrease when a display is formed and that curing can be performed only with light of 395 nm or more. Carboxylic-diphenylphosphine oxide.

The content of the photopolymerization initiator (D) is preferably 0.05 to 6 parts by mass, more preferably 0.5 to 5 parts by mass, and most preferably 100 parts by mass of the total of (A), (B), and (C). It is preferably 1 to 4 parts by mass. When it is 0.05 parts by mass or more, the effect of curing acceleration can be surely obtained, and when it is 6 parts by mass or less, the transmittance of visible light does not decrease when a display is produced.

The glass transition temperature of the cured product obtained from the composition of the present embodiment is preferably 200° C. or higher. When the glass transition temperature of the cured body is 200° C. or higher, when an inorganic passivation film is formed on the cured body of the composition of the present embodiment by techniques such as CVD, the non-uniformity of the inorganic passivation film formation due to thermal expansion does not occur. (mura) pinhole, 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, and can be measured by a known method such as DSC or dynamic viscoelasticity spectrum, preferably using dynamic viscoelasticity spectrum. In the dynamic viscoelasticity spectrum, stress and strain can be applied to the cured body at a constant heating rate, and the temperature at the top of the peak showing the loss tangent (hereinafter abbreviated as tan δ) can be regarded as the glass transition temperature. The glass transition temperature is considered to be below -150°C or above a certain temperature (Ta°C) when the tanδ peak does not appear even if it is raised to a certain temperature (Ta°C) from a relatively low temperature of about -150°C, but The composition having a glass transition temperature of -150°C or lower is not considered because of its structure, and therefore, it can be regarded as a certain temperature (Ta°C) or higher.

In the composition of the present embodiment, in order to improve storage stability, a polymerization inhibitor can be used.

The composition of this embodiment can be used as a resin composition. The composition of this embodiment can be used as a (meth)acrylic 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 coating agent or an adhesive agent. The composition of this embodiment can be used as a sealant for organic EL display elements.

The method of irradiating visible light or ultraviolet light to cure the composition includes, for example, a method of curing the composition by irradiating at least one of visible light or ultraviolet light to the composition. Examples of energy irradiation sources for irradiating such visible light or ultraviolet light include deuterium lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, low-pressure mercury lamps, xenon lamps, xenon-mercury hybrid lamps, halogen lamps, excimer lamps, indium lamps, and thallium lamps. , LED lamps, and energy irradiation sources such as electrodeless discharge lamps. The composition of the present embodiment is preferably cured at a wavelength of 380 nm or more, more preferably cured at a wavelength of 395 nm or more, and more preferably cured at a wavelength of 395 nm, from the viewpoint of not easily damaging the organic EL element. . The wavelength of the energy irradiation source is preferably 500 nm or less because the temperature of the irradiation portion rises due to emission of infrared light, which may cause damage to the organic EL element. As the energy irradiation source, an LED lamp having a short emission wavelength is preferable, for example, an LED lamp having an emission peak wavelength of 395 nm can be preferably used.

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

The viscosity of the composition of the present embodiment is preferably 2 mPa·s or more and 50 mPa·s or less measured under the conditions of 25° C. and 100 rpm using an E-type viscometer. When the viscosity is less than 2 mPa·s, the applied sealant for organic EL display elements may flow out from the organic EL display element before curing. When the viscosity exceeds 50 mPa·s, coating by inkjet may become difficult. The viscosity of the composition is preferably 5 mPa·s or more. The viscosity of the composition is preferably below 20 mPa·s.

The transparency of the composition of this embodiment is preferably 97% or more, more preferably 99% or more, when the thickness of the organic film is 1 μm or more and 10 μm or less, and the spectral transmittance in the ultraviolet-visible light region of 360 nm or more and 800 nm or less is preferably 97% or more. . If it is 97% or more, an organic EL device excellent in brightness and contrast can be provided.

The sealing layer composed 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 the sealing effect on the organic EL element is almost the same as that in the case of five groups when the inorganic/organic laminate is six or more groups. 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. When the thickness of the organic film is less than 1 μm, particles generated during element formation cannot be completely covered, and coating with good flatness on the inorganic film is difficult. When the thickness of the organic film exceeds 15 μm, moisture may penetrate from the side surface of the organic 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 the sealing substrate include the aforementioned substrates. Among them, a substrate transparent to visible light is preferable. Among the substrates that are transparent to visible light (transparent sealing substrates), one or more of the group consisting of a glass substrate and a plastic substrate are 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, and more preferably 50 μm or more and 300 μm or less. By providing the transparent sealing substrate on the upper layer of the sealing layer, deterioration of the surface of the uppermost organic film when it comes into contact with gas can be suppressed, and the barrier properties of the organic EL device can be improved.

Next, the manufacturing method of the organic EL device which has such a structure is demonstrated. First, an anode patterned in a predetermined shape, an organic EL layer including a light-emitting layer, and a cathode are sequentially formed on a 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 element, a bank is formed to divide a light-emitting region into a matrix shape, and an organic EL layer including a light-emitting layer in a region surrounded by the bank is formed.

Next, on the substrate on which the organic EL element is to be formed, a film having a predetermined thickness is formed by a film formation 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. the first inorganic film. Thereafter, the composition of the present embodiment is adhered to the first inorganic film using a solution coating method, a spray coating method, a flash vapor deposition method, an inkjet method, or the like. Among them, the ink jet method is preferred. After that, the composition is cured by irradiation with energy rays such as ultraviolet light, electron beam, plasma, and the like, and a first organic film is formed. Through the above steps, one set of inorganic/organic laminates is formed.

The formation steps of the inorganic/organic laminate described above are repeated only a predetermined number of times. However, with regard to the last group, that is, the uppermost inorganic/organic laminate, the composition may be attached to the inorganic film so as to flatten the upper surface by a coating method, flash deposition method, inkjet method, or the like. surface.

Next, on the surface on which the composition is adhered on the substrate, the transparent sealing substrate is bonded to the surface on which the composition on the substrate is adhered. When fitting, perform position alignment. After that, the composition of the present embodiment existing between the inorganic film of the uppermost layer and the transparent sealing substrate is cured by irradiating energy rays from the transparent sealing substrate side. Thereby, the composition is cured, and at the same time as the uppermost organic film is formed, the uppermost organic film is joined to the transparent sealing substrate. Through the above steps, the manufacturing method of the organic EL device is completed.

After the composition is attached to the inorganic film, it may be partially irradiated with energy rays for polymerization. Thereby, when the transparent sealing substrate is placed, the shape of the composition composed of the uppermost organic film can be prevented from being collapsed. 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 is exemplified. This embodiment can also be applied to a bottom emission type organic EL device in which light generated in the organic EL layer is emitted from the substrate side.

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

According to the example of this embodiment, the sealing layer for shielding the organic EL element formed on the first plastic substrate from the outside air is formed, and the transparent sealing substrate is further formed on the sealing layer, so that the organic EL element can be obtained. The element has a sealing structure with sufficient barrier properties to water vapor and oxygen. According to the example of this embodiment, a sealing structure having sufficient adhesive strength between the transparent sealing substrate and the sealing layer can be obtained.

According to the aspect of the present embodiment, after attaching the composition of the present embodiment that constitutes the uppermost organic film of the sealing layer, the transparent sealing substrate is placed without curing the composition, and then the composition is cured. Bonding between the sealing layer and the transparent sealing substrate can be performed simultaneously with the formation of the uppermost organic film constituting the sealing layer. Therefore, this embodiment has the effect of being able to simplify a process compared with the case where an adhesive agent adheres a sealing layer and a transparent sealing substrate.

According to JIS Z0208:1976, in the composition of this embodiment, the moisture permeability value measured by exposing the cured product to a thickness of 100 μm in an environment of 85° C. and 85% RH for 24 hours is preferably 250 g/m ² or less. When the above-mentioned moisture permeability exceeds 250 g/m ² , moisture will reach the organic light-emitting material layer, and dark spots may occur.

According to the present embodiment, it is possible to provide an organic EL display element sealant excellent in curability, transparency of a cured product, and barrier properties while being easily applied by an inkjet method. According to this embodiment, the manufacturing method of the organic EL display element using the sealant for organic EL display elements can be provided.

[Example]

(Experimental examples 1 to 15)

The compositions were prepared and evaluated by the following methods.

(production of composition)

The materials used in Table 1 were used. According to the composition of Table 2, each used material was mixed, and a composition was prepared. Using the obtained composition, measurement of E-type viscosity, moisture permeability, coating area enlargement ratio, curing ratio, transparency, glass transition temperature, and organic EL evaluation was performed according to the evaluation methods shown below. The results are shown in Table 2. The abbreviations shown in Table 1 are used for the names of the compositions in Table 2.

[E type viscosity]

The viscosity of the composition was measured using an E-type viscometer under the conditions of a conical rotor of 1°34'×R24, a temperature of 25° C., and a rotational speed of 100 rpm.

[Light curing conditions]

When evaluating the cured physical properties of the composition, the composition was cured under the following light irradiation conditions. The composition was cured under the condition of ^{a cumulative light amount of 1,500 mJ/cm 2} at a wavelength of 395 nm through an LED lamp (UV-LED LIGHT SOURCE H-4MLH200-V1, manufactured by HOYA) emitting a wavelength of 395 nm to obtain a cured product.

[moisture permeability]

A sheet-like cured product with a thickness of 0.1 mm was prepared under the above-mentioned photocuring conditions. According to JIS Z0208: 1976 "Moisture Permeability Test Method for Moisture-Proof Packaging Materials (Cup Method)", calcium chloride (anhydrous) was used as a moisture absorbing agent. Measured at 60°C and 90% relative humidity.

[Cure rate]

The composition obtained in each experimental example was coated with the composition having a size of 10 mm×10 mm on the cleaned alkali-free glass so as to have a thickness of 10 μm using the above-mentioned ink jet apparatus, and nitrogen with an oxygen concentration of 0.1% or less was applied. It was hardened under the aforementioned photo-curing conditions in the atmosphere, and the curing rate was measured by the following procedure. Using an infrared spectrometer (Nicolet is5 manufactured by Thermo Scientific, DTGS detector, resolution 4 cm ⁻¹ ) for the above-mentioned composition after curing and the above-mentioned composition after curing, infrared light was incident on the measurement sample to measure infrared light spectrum. According to the obtained infrared spectrum, the peaks before and after curing did not change, and ^{the stretching vibration peaks of methylene carbon-hydrogen bonds observed around 2950 cm -1} were used as internal standards, and then the internal standards were used before and after curing. The peak area, the peak area before and after curing around ^{810 cm -1} and the peak area generated by the out-of-plane bending vibration of the carbon-hydrogen bond that forms a carbon-carbon double bond in the (meth)acrylate, are calculated by the following formula cure rate.

Curing rate (%)=[1-(Ax/Bx)/(Ao/Bo)]×100

Here, Ao: shows the peak area before curing ^{around 810 cm −1 .}

Ax: shows the peak area after curing ^{around 810 cm −1 .}

Bo: shows the peak area before curing ^{around 2950 cm −1 .}

Bx: shows the peak area after curing ^{around 2950 cm −1 .}

[transparency]

The composition obtained in each experimental example was formed between two glass plates of 25 mm×25 mm×1 mmt (alkali-free glass, Eagle XG manufactured by Corning Co., Ltd.) to have a thickness of 10 μm, and an LED lamp was used so that a wavelength of 395 nm was obtained. It irradiated so that the irradiation amount of ultraviolet light might become 1500mJ/cm<^2> , it was hardened, and the hardened body was obtained. About the obtained hardened body, the spectral transmittance of 380 nm, 412 nm, and 800 nm was measured with an ultraviolet-visible spectrophotometer ("UV-2550" by Shimadzu Corporation), and it was set as transparency.

[Glass transition temperature]

The composition obtained in each experimental example was sandwiched by a PET film using a silicon wafer with a thickness of 1 mm as a mold. After the composition was cured from the upper surface under the aforementioned photocuring conditions, it was then cured from the bottom under the aforementioned photocuring conditions to prepare a cured body of the composition having a thickness of 1 mm. The produced cured body was cut into a length of 50 mm and a width of 5 mm with a cutter, and used as a cured body for glass transition temperature measurement. Using the dynamic viscoelasticity measuring device "DMS210" manufactured by Seiko Instruments Inc., the cured body was subjected to a stress and strain of 1 Hz in the tensile direction in a nitrogen atmosphere, and the temperature was increased from -150°C to 200°C at a rate of 2°C per minute. °C, while measuring tanδ, the temperature at the top of the tanδ peak was taken as the glass transition temperature. The peak top of tan δ is set as the maximum value in the region where tan δ is 0.3 or more. When tanδ is 0.3 or less in the range of -150°C to 200°C, the peak top of tanδ exceeds 200°C, and the glass transition temperature exceeds 200°C (200<).

[Expansion rate of coating area]

On a substrate of 70 mm x 70 mm x 0.7 mmt (alkali-free glass (Eagle XG manufactured by Corning)), an ink jet ejection apparatus (MID500B manufactured by Musashi Hi-Tech Co., Ltd., solvent type head "MID head") was used to form The composition obtained in each experimental example was pattern-coated in a manner of 4 mm×4 mm×10 μmt. Before using the alkali-free glass, it was washed with acetone and isopropyl alcohol, respectively, and then washed with UV-208 UV-ozone cleaning apparatus manufactured by Technovision for 5 minutes. After pattern coating, it was left to stand for 5 minutes under the conditions of an ambient temperature of 23°C and a relative humidity of 50%, and the flatness after inkjet coating was evaluated by the expansion ratio of the coating area (refer to the following formula). When the enlargement ratio of the coating area is larger, the flatness after inkjet coating is better, and the coating property is better.

(Enlargement rate of coating area)=((5 minutes after pattern coating, contact area of composition with substrate surface)/(contact area of composition with substrate surface immediately after pattern coating)) ×100(%)

[Organic EL evaluation]

[Production of organic EL element substrate]

The glass substrate with the ITO electrode attached was cleaned with acetone and isopropanol, respectively. Then, the following compounds were sequentially deposited by a vacuum deposition method to form a thin film to obtain an organic EL element substrate consisting of an anode/hole injection layer/hole transport layer/light emitting layer/electron injection layer/cathode. The constitution of each layer is as follows.

‧Anode: ITO, the film thickness of the anode is 250nm

‧Hole injection layer: copper phthalocyanine

‧Hole transport layer: N,N'-diphenyl-N,N'-dinaphthylbenzidine (α-NPD)

‧Light-emitting layer: Tris (8-hydroxyquinoline) aluminum (metal complex), the film thickness of the light-emitting layer is 1000Å, and the light-emitting layer also functions as an electron transport layer.

‧Electron injection layer: lithium fluoride

‧Cathode: aluminum, anode film thickness 250nm

[Production of organic EL element]

Using the above-mentioned inkjet apparatus under a nitrogen atmosphere, the composition obtained in each experimental example was coated with a thickness of 10 μm on an organic EL element substrate of 2 mm × 2 mm, and the composition was cured according to the above-mentioned photocuring conditions. A mask (cover body) having an opening of 4 mm×4 mm was provided in a bulk manner, and a SiN film was formed by a plasma CVD method to obtain an organic EL display element. The thickness of the formed SiN is about 1 μm. Thereafter, an organic EL element (organic EL evaluation) was produced by laminating with a 4 mm×4 mm×0.7 mmt alkali-free glass (Eagle XG manufactured by Corning) using a 4 mm×4 mm×25 μmt transparent base-free double-sided tape.

[Initial]

Immediately after the fabricated organic EL element was exposed for 1000 hours at 85° C. and relative humidity of 85% by mass, a voltage of 6 V was applied, and the light-emitting state of the organic EL element was observed visually and with a microscope, and the diameter of the black spot was measured.

[durability]

Immediately after the fabricated organic EL element was exposed for 1000 hours at 85° C. and relative humidity of 85% by mass, a voltage of 6 V was applied, and the light-emitting state of the organic EL element was observed visually and with a microscope, and the diameter of the black spot was measured. The diameter of the black spot is preferably 300 μm or less, more preferably 50 μm or less, and most preferably no black spot.

From the above experimental examples, it was found as follows.

In this embodiment, it is possible to provide a composition which is excellent in dischargeability by high-precision inkjet and flatness after inkjet coating, and excellent in low moisture permeability, transparency, and durability (including long-term durability) . In the case where acyclic bifunctional methacrylate and acyclic bifunctional acrylate are used in combination as (B), and lauryl (meth)acrylate or n-octyl acrylate is used as (C), there is an excellent Low moisture permeability and durability (including long-term durability) (Experimental Examples 1 to 4). When the acyclic bifunctional methacrylate and the acyclic bifunctional acrylate were not used in combination as (B), the expansion ratio of the coating area was large, and the coating properties were excellent (Experimental Examples 5 to 11). In the case of using dicyclopentenoxyethyl (meth)acrylate as (C), there was excellent low moisture permeability (Experimental Example 6). When conditions such as (A) 3 to 10 parts by mass, (B) 85 to 95 parts by mass, and (C) 2 to 10 parts by mass are satisfied, the curing rate is low and the flatness after application is excellent (Experimental Example 12) . When (C) was not used, coating by inkjet was not possible (Experimental Example 13). When (B) was not used, coating by inkjet was not possible (Experimental Example 14). When (A) was not used, low moisture permeability and long-term durability could not be obtained (Experimental Example 15).

[Industrial Availability]

The composition of the present embodiment is excellent in dischargeability by high-precision inkjet and flatness after inkjet coating, has low moisture permeability and transparency, and does not degrade organic EL elements. In this embodiment, inkjet coating can be performed in a short time. The composition of this embodiment is preferably suitable for use in electronic products, particularly display parts such as organic EL, or electronic parts for image sensors such as CCD and CMOS, and more particularly, for bonding components used in semiconductor parts, etc. . In particular, it is most suitable for the bonding of organic EL sealing, and satisfies the performance required of the adhesive for element sealing such as organic EL elements.

The above-mentioned composition is an embodiment of the present embodiment, and the adhesive agent, the sealant for organic EL elements, the cured body, the cover body, the joined body, the organic EL device, the display, and the manufacturing method thereof of the present embodiment also have The same composition and effect.

Claims (25)

A sealant for organic electroluminescence display elements, comprising (A) trimethylolpropane tri(meth)acrylate, (B) alkanediol di(meth)acrylate, (C) monofunctional (methyl) ) Acrylate, and (D) a photopolymerization initiator, wherein the sealant for organic electroluminescence display elements includes (A) in a total of 100 parts by mass of (A), (B) and (C) 3-70 mass parts, (B) 15-95 mass parts, and (C) 2-40 mass parts. A sealant for organic electroluminescence display elements, comprising (A) trimethylolpropane tri(meth)acrylate, (B) alkanediol di(meth)acrylate, (C) monofunctional (methyl) ) Acrylate, and (D) a photopolymerization initiator, wherein the sealant for organic electroluminescence display elements includes (A) in a total of 100 parts by mass of (A), (B) and (C) 3-10 mass parts, (B) 85-95 mass parts, and (C) 2-10 mass parts. The encapsulant for organic electroluminescence display elements according to claim 1 or claim 2, which is 100 parts by mass relative to the total of (A), (B) and (C), including (D) 0.05 to 6 parts by mass. The encapsulant for organic electroluminescence display elements according to claim 1 or claim 2, wherein the viscosity measured with an E-type viscometer at 25°C is 2 mPa·s or more and 50 mPa·s or less. The encapsulant for organic electroluminescence display elements according to claim 1 or claim 2, which does not contain a polyfunctional (meth)acrylate oligomer/polymer. The glass transition temperature of the cured body obtained from the sealant for organic electroluminescence display elements according to claim 1 or claim 2 of the claim 2 is 200° C. or higher. The sealing compound for organic electroluminescent display elements as described in claim 1 or claim 2, wherein (B) is an alkylene glycol di(meth)acrylate having 6 or more carbon atoms. The sealing compound for organic electroluminescence display elements as described in claim 1 or claim 2, wherein (B) is an alkylene glycol di(meth)acrylate having 12 or less carbon atoms. The encapsulant for organic electroluminescence display elements according to claim 1 or claim 2, wherein (B) is composed of 1,9-nonanediol di(meth)acrylate, di(methyl) base) one or more of the group consisting of 1,10-decanediol acrylate and 1,12-dodecanediol di(meth)acrylate. The sealing compound for organic electroluminescence display elements as described in claim 1 or claim 2, wherein (B) contains an acyclic bifunctional methacrylate and an acyclic bifunctional acrylate. The sealing compound for organic electroluminescence display elements as described in claim 1 or claim 2, wherein (C) is an alkyl (meth)acrylate having 8 or more carbon atoms. The sealing compound for organic electroluminescent display elements as described in claim 1 or claim 2, wherein (C) is lauryl (meth)acrylate. The sealing compound for organic electroluminescence display elements as described in claim 1 or claim 2, wherein (C) is a (meth)acrylate having an alicyclic hydrocarbon group. The sealing compound for organic electroluminescence display elements as described in claim 1 or claim 2, wherein (C) contains a monofunctional methacrylate and a monofunctional acrylate. The sealing compound for organic electroluminescence display elements as described in claim 1 or claim 2, wherein (D) is an acylphosphine oxide derivative. A cured body cured by the sealant for an organic electroluminescence display element according to any one of the first to fifteenth claims. A cover body covered with the sealant for an organic electroluminescence display element according to any one of claims 1 to 15 of the patent application scope. A joined body joined by the sealant for an organic electroluminescence display element according to any one of claims 1 to 15 of the scope of application. A curing method of the sealant for an organic electroluminescence display element according to any one of claims 1 to 15 of the patent application scope, wherein the curing method is performed using a wavelength of 380 nm or more and 500 nm or less. A curing method of the sealant for an organic electroluminescence display element according to any one of the claims 1 to 15 of the patent application scope is to use an LED lamp with an emission peak wavelength of 395 nm. A coating method of the sealant for an organic electroluminescence display element according to any one of the claims 1 to 15 of the patent application scope is coating by using an ink jet method. An organic EL device comprising the cured body described in item 16 of the patent application scope. A display, comprising the cured body described in item 16 of the patent application scope. A sealant for organic electroluminescence display elements, comprising (A) trimethylolpropane tri(meth)acrylate, (B) alkanediol di(meth)acrylate, (C) monofunctional (methyl) ) Acrylate, and (D) a photopolymerization initiator, wherein the sealant for organic electroluminescence display elements includes (A) in a total of 100 parts by mass of (A), (B) and (C) 1-70 mass parts, (B) 15-98 mass parts, and (C) 1-40 mass parts. A sealant for organic electroluminescence display elements, comprising (A) trimethylolpropane tri(meth)acrylate, (B) alkanediol di(meth)acrylate, (C) monofunctional (methyl) ) Acrylate, and (D) a photopolymerization initiator, wherein the sealant for organic electroluminescence display elements includes (A) in a total of 100 parts by mass of (A), (B) and (C) 1-10 mass parts, (B) 85-98 mass parts, and (C) 1-10 mass parts.