JP7057403B2 - Composition - Google Patents

Description

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

Organic electroluminescence (EL) devices are attracting attention as device bodies capable of high-luminance emission. However, there is a problem that the light emission characteristics are deteriorated due to deterioration due to moisture.

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. It is provided with a sealing layer in which 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, a encapsulant for an organic electroluminescence display element 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 9).

Japanese Unexamined Patent Publication No. 10-74583 Japanese Unexamined Patent Publication No. 2001-307873 Japanese Unexamined Patent Publication No. 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

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

In Patent Document 1, when mass-producing, a method is adopted in which an organic EL element is sandwiched between a base material having low moisture permeability, for example, glass or the like, and the outer peripheral portion is sealed. In this case, since this structure has a hollow sealing structure, it is not possible to prevent moisture from infiltrating into the hollow sealing structure, and there is a problem that the organic EL element is deteriorated.

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 thin film 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. rice field. Patent Document 5 proposes a photo-curing type 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. Patent Documents 6 to 9 do not describe the combined use of (A) trifunctional or higher acyclic polyfunctional (meth) acrylate and (B) acyclic bifunctional (meth) acrylate in a specific amount. Patent Documents 6 to 9 do not describe the coatability.

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

Embodiments of the present invention can provide:

<1> (A) trifunctional or higher acyclic polyfunctional (meth) acrylate, (B) acyclic bifunctional (meth) acrylate, (C) monofunctional (meth) acrylate, (D) photopolymerization initiator (A), (B), (C) in a total of 100 parts by mass, (A) 3 to 70 parts by mass, (B) 15 to 95 parts by mass, (C) 2 to 40. A composition containing parts by mass.

<2> (A) trifunctional or higher acyclic polyfunctional (meth) acrylate, (B) acyclic bifunctional (meth) acrylate, (C) monofunctional (meth) acrylate, (D) photopolymerization initiator (A), (B), (C) in a total of 100 parts by mass, (A) 3 to 10 parts by mass, (B) 85 to 95 parts by mass, (C) 2 to 10 parts. A composition containing parts by mass.

<3> The composition according to <1> or <2>, which contains 0.05 to 6 parts by mass of (D) with respect to 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 by 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> A composition having a glass transition temperature of a cured product obtained from the composition according to any one of <1> to <5> of 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 alkanediol di (meth) acrylate having 6 or more carbon atoms.

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

<10> (B) is one of the group consisting of 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, and 1,12-dodecanediol di (meth) acrylate. The composition according to any one of <1> to <9>, which is more than a species.

<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.

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

The composition according to any one of <1> to <11>, wherein <14> (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.

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

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

<18> A coating agent comprising the composition according to any one of <1> to <17>.

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

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

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

<22> A bonded body bonded with the composition according to any one of <1> to <17>.

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

<24> The method for curing a composition according to any one of <1> to <17>, which is cured by an LED lamp having an emission peak wavelength of 395 nm.

<25> The method for applying a composition according to any one of <1> to <17>, which is applied by using an inkjet method.

<26> An organic EL device containing the cured product according to <20>.

<27> A display containing the cured product according to <20>.

<28> (A) trifunctional or higher acyclic polyfunctional (meth) acrylate, (B) acyclic bifunctional (meth) acrylate, (C) monofunctional (meth) acrylate, (D) photopolymerization initiator (A), (B), (C) in a total of 100 parts by mass, (A) 1 to 70 parts by mass, (B) 15 to 98 parts by mass, (C) 1 to 40. A composition containing parts by mass.

<29> (A) trifunctional or higher acyclic polyfunctional (meth) acrylate, (B) acyclic bifunctional (meth) acrylate, (C) monofunctional (meth) acrylate, (D) photopolymerization initiator. (A), (B), (C) in a total of 100 parts by mass, (A) 1 to 10 parts by mass, (B) 85 to 98 parts by mass, (C) 1 to 10 by mass. A composition containing parts by mass.

The composition according to the embodiment of the present invention can exhibit excellent effects of coatability and low moisture permeability.

Hereinafter, this embodiment will be described. In the present specification, unless otherwise specified, the numerical range shall include the upper limit value and the lower limit value.

Hereinafter, a top-emission type organic EL device that irradiates 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 laminated in this order on a substrate, and an inorganic film and an organic film covering the entire organic EL element. It has a structure in which a sealing layer made of the laminated body of the above and a sealing substrate provided on the sealing layer are formed in order.

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, polyoxadiazole, aromatic polyamide, polybenzoimidazole, polybenzobisthiazole, polybenzoxazole, polythiazole, and polyparaphenylene. Examples thereof include vinylene, polymethylmethacrylate, polystyrene, polycarbonate, polycycloolefin, polyacrylic acid and the like. Among these, polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, polyoxadiazole, aromatic polyamide, polybenzoimidazole, and polybenzo are excellent in low water permeability, low oxygen permeability, and heat resistance. Polyimide, polyetherimide, polyethylene terephthalate in that one or more of the group consisting of bistiazole, polybenzoxazole, polythiazole, and polyparaphenylene vinylene are preferable, and energy rays such as ultraviolet rays or visible light are highly transparent. , 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 (Indium Tin Oxide, hereinafter referred to as ITO), metal oxides such as tin oxide, gold (Au), platinum (Pt), silver (Ag), and copper. Examples thereof include a metal such as (Cu) or an alloy containing at least one of them, polyaniline or a derivative thereof, and an organic transparent conductive film such as polythiophene or a derivative thereof. Of these, ITO is preferred. 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, also 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 vapor 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 the organic substance include a dye-based material, a metal complex-based material, and a polymer material. The dopant material is doped in the 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 consisting of these organics and optionally doped dopants is typically 20-2,000 Å.

(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, oxadiazole dimers, pyrazoline dimers and the like.

(Metal complex material)
Examples of the metal complex-based material include metal complexes that emit light from triple-term excited states 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), and dysprosium (Dy), aluminum (Al), zinc (Zn), berylium (Be), and the like 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 the 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, polymerized dyes and metal complex-based luminescent materials, and the like. Can be mentioned.

Among the luminescent materials, examples of the material that emits blue light include distyrylarylene 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 a polyvinylcarbazole derivative, a polyparaphenylene derivative, and a polyfluorene derivative 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 a coumarin derivative, a thiophene ring compound, a polyparaphenylene vinylene derivative, a polythiophene 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, polythiophene derivatives, and polyfluorene derivatives is preferable.

(Dopant material)
Examples of the dopant material include a perylene derivative, a coumarin derivative, a rubrene derivative, a quinacridone derivative, a squalium derivative, a porphyrin derivative, a styryl-based dye, a tetracene derivative, a pyrazolone derivative, decacyclene, and phenoxazone. 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 the layer provided between the light emitting layer and the anode, the hole injection layer for improving the hole injection efficiency from the anode, the hole injection layer, or the hole transport layer closer to the anode to the light emitting layer. Examples include a hole transport layer that improves hole injection. The layer provided between the light emitting layer and the cathode has a function of improving electron injection from an electron injection layer for improving electron injection efficiency from the cathode, an electron injection layer, or an electron transport layer closer to the cathode. An electron transport layer and the like can be mentioned.

(Hole injection layer)
Examples of the material forming the hole injection layer include phenylamine-based, starburst-type amine-based, phthalocyanine-based, vanadium oxide, molybdenum oxide, ruthenium oxide, oxides such as aluminum oxide, amorphous carbon, polyaniline, and polythiophene derivatives. Be done. Of these, the phthalocyanine type is preferable.

(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, polyarylamines or their 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. Of these, benzidine derivatives are preferred.

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

(Electron transport layer)
Materials 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-hydroxyquinoline or its derivative, polyquinolin or its derivative, polyquinoxaline 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 derivatives, 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 the Group IA and Group IIA of the Periodic Table, depending on the type of the light emitting layer, and has a work function of 1. .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 a Ca layer and a layer formed of one or more of a metal and a metal having a work function of 1.5 to 3.0 eV and an oxide, a halide and a 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 carbon 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. Strontium (Sr), magnesium oxide, magnesium fluoride, strontium fluoride, fluoride as the metal of the periodic table IIA or its oxide, halide, and carbon oxide having a work function of 1.5 to 3.0 eV. Examples include barium, strontium oxide, magnesium carbonate and the like. Of these, lithium fluoride is preferred.

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. Examples of the material contained in the cathode include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), beryllium (Be), magnesium (Mg), and calcium (Ca). , Strontium (Sr), barium (Ba), aluminum (Al), scandium (Sc), vanadium (V), zinc (Zn), ittrium (Y), indium (In), cerium (Ce), sumarium (Sm) , Europium (Eu), Rubidium (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), One or more of platinum (Pt), copper (Cu), chromium (Cr), manganese (Mn), titanium (Ti), cobalt (Co), nickel (Ni), tungsten (W), tin (Sn) Examples thereof include alloys made of, graphite or graphite interlayer compounds, and 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, and laminated structures of these alloys with metals such as Al, Ag, and Cr. Of these, Al is preferred. 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) Anodic / 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 to the gas in order to prevent a gas such as water vapor or oxygen from coming into contact with the organic EL element. Inorganic film and organic film are alternately formed from the bottom of this sealing layer. The inorganic / organic laminate may be formed repeatedly two or more times.

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 narrower region than the region where the inorganic film is formed. This is because if the organic film is formed to be the same as 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 inkjet coating capable of coating with excellent flatness of a film thickness of 3 μm or more in a short time, has excellent ejection properties by inkjet and flatness after inkjet coating, and has a barrier property against water vapor and the like ( It is an object of the present invention to provide a sealant for an organic electroluminescence display element that forms the organic film having excellent low moisture permeability (hereinafter, also referred to as low moisture permeability). If the coating method by the inkjet method is used, the organic film can be formed at high speed and uniformly.

The compositions of the present embodiment are (A) trifunctional or higher acyclic polyfunctional (meth) acrylate, (B) acyclic bifunctional (meth) acrylate, (C) monofunctional (meth) acrylate, (D). ) A composition containing a photopolymerization initiator. The (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. The trifunctional (meth) acrylate refers to a compound having three (meth) acryloyl groups. The bifunctional (meth) acrylate refers to a compound having two (meth) acryloyl groups. The 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, most preferably 90 parts by mass or more, and 95 parts by mass in 100 parts by mass of the composition. The above is even more preferable. In the (meth) acrylate of the present embodiment, the total content of (A), (B), and (C) is preferably 80 parts by mass or more, more preferably 90 parts by mass or more, based on 100 parts by mass of the (meth) acrylate. Preferably, 95 parts by mass or more is most preferable, and 100 parts by mass is even more preferable.

(A) As the trifunctional or higher functional non-cyclic polyfunctional (meth) acrylate, a non-cyclic and trifunctional or higher functional (meth) acrylate monomer is preferable (hereinafter, (meth) acrylate monomer (hereinafter, (meth) acrylate monomer). Meta) Sometimes called acrylate.). As the (A) trifunctional or higher acyclic polyfunctional (meth) acrylate monomer, an acyclic polyfunctional (meth) acrylate represented by the formulas (1), (2) or (3) is preferable.

(In the formula, R ¹ independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a group represented by the formula (4), and in the formulas (1) to (3), at least three of R ¹ are. It is a 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. .).

Examples of the acyclic polyfunctional (meth) acrylate represented by the formula (1), (2) or (3) include trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, and propoxylation. Examples thereof include trimethylolpropane tri (meth) acrylate and pentaerythritol tri (meth) acrylate, and examples of the tetrafunctional or higher functional (meth) acrylate monomer include dimethylolpropanetetra (meth) acrylate and pentaerythritol tetra (meth) acrylate. Examples thereof include pentaerythritol ethoxytetra (meth) acrylate, dipentaeristolpenta (meth) acrylate, and dipentaeristolhexa (meth) acrylate. Among these, trimethylolpropane tri (meth) acrylate is preferable because it has a large effect on low moisture permeability, ejection property by inkjet, and flatness after inkjet application.

(A) The content of the trifunctional or higher acyclic polyfunctional (meth) acrylate may be 1 to 70 parts by mass with respect to 100 parts by mass in total of (A), (B) and (C). It is preferably 3 to 70 parts by mass, and more preferably 3 to 70 parts by mass. If the content of (A) is less than 1 part by mass, it is inferior in terms of low moisture permeability, and if it exceeds 70 parts by mass, the viscosity and surface tension of the composition become too high, so that the flatness after inkjet coating deteriorates. .. From the viewpoint of achieving both low moisture permeability and flatness after inkjet coating, 7 to 60 parts by mass is preferable, and 9 to 55 parts by mass is more preferable. Further, when specializing in flatness after inkjet coating and low curing rate, it is preferably in the range of 1 to 10 parts by mass, and more preferably in the range of 3 to 10 parts by mass.

(B) The acyclic bifunctional (meth) acrylate is preferably an acyclic and bifunctional polyfunctional (meth) acrylate monomer. As the (B) acyclic bifunctional (meth) acrylate monomer, an alkanediol di (meth) acrylate is preferable because it has a large effect on low moisture permeability, ejection property by inkjet, and flatness after inkjet application. Among the alkanediol di (meth) acrylates, α, ω-linear alkanediol di (meth) acrylates are preferable. The number of carbon atoms in the alkane is preferably 6 or more. The number of carbon atoms in the alkane is preferably 12 or less. 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.

The content of (B) acyclic bifunctional (meth) acrylate is preferably 15 to 98 parts by mass, more preferably 15 to 98 parts by mass, based on 100 parts by mass of the total of (A), (B) and (C). It is more preferably contained in an amount of 95 parts by mass, and most preferably it is contained in an amount of 20 to 95 parts by mass. If the content of (B) is less than 15 parts by mass, it is inferior in terms of low moisture permeability, and if it exceeds 98 parts by mass, the surface tension becomes too high and the flatness after inkjet coating deteriorates. From the viewpoint of achieving both low moisture permeability and flatness after inkjet coating, 25 to 75 parts by mass is preferable, and 40 to 72 parts by mass is more preferable. On the other hand, when specializing in flatness after inkjet coating and low curing rate, it is preferably in the range of 85 to 98 parts by mass, and more preferably in the range of 85 to 95 parts by mass.

(B) The acyclic bifunctional (meth) acrylate preferably contains an acyclic bifunctional methacrylate and an acyclic bifunctional acrylate. Acyclic bifunctional methacrylate is highly effective in terms of low moisture permeability. The acyclic bifunctional acrylate has a great effect on the flatness after inkjet coating. In terms of achieving both low moisture permeability and flatness after inkjet application, the content ratio of acyclic bifunctional methacrylate and acyclic bifunctional acrylate is 100 in total of acyclic bifunctional methacrylate and acyclic bifunctional acrylate. In terms of mass ratio in parts by mass, acyclic bifunctional methacrylate: acyclic bifunctional acrylate = 10 to 90:90 to 10, preferably 25 to 75:75 to 25, and 40 to 60:60 to 40. Most preferred.

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

(C) Among the monofunctional (meth) acrylate monomers, the alkyl (meth) acrylate is preferable because it has a large effect on the ejection property by inkjet and the flatness after application to inkjet. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, and isodecyl (meth). Examples thereof include acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate. Among the alkyl (meth) acrylates, the alkyl (meth) acrylate having an alkyl group having 8 or more carbon atoms is preferable. Among the alkyl (meth) acrylates, the alkyl (meth) acrylate having an alkyl group having 16 or less carbon atoms is preferable. Among the alkyl (meth) acrylates having an alkyl group having 8 or more and 16 or less carbon atoms, lauryl (meth) acrylate is preferable. Among the alkyl groups of the alkyl (meth) acrylate, an unsubstituted saturated hydrocarbon group is preferable. Among the saturated hydrocarbon groups, a chain compound is preferable.

(C) Among the monofunctional (meth) acrylate monomers, (meth) acrylate having an alicyclic hydrocarbon group is preferable in terms of low moisture permeability. Examples of the alicyclic hydrocarbon group include a group having a dicyclopentadiene skeleton such as a dicyclopentanyl group and a dicyclopentenyl group, a cyclohexyl group, an isobornyl group, a cyclodecatorien 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 cyclodecatorien (meth) acrylate. Among the (meth) acrylates having a dicyclopentadiene skeleton, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) One or more of the group consisting of acrylate is preferable, and one or more of the group consisting of dicyclopentenyloxyethyl (meth) acrylate and dicyclopentanyloxyethyl (meth) acrylate is more preferable, and dicyclopentenyloxy Ethyl (meth) acrylate is most preferred. Among the alicyclic hydrocarbon groups, unsubstituted is preferable.

The content of the monofunctional (meth) acrylate (C) is preferably 1 to 40 parts by mass with respect to 100 parts by mass in total of (A), (B) and (C), and is 2 to 40 parts by mass. It is more preferable to contain it. If 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 if it exceeds 40 parts by mass, the surface tension is inferior in terms of low moisture permeability. From the viewpoint of achieving both flatness and low moisture permeability after inkjet coating, 1 to 30 parts by mass is preferable, 5 to 30 parts by mass is more preferable, 7 to 20 parts by mass is most preferable, and a range of 7 to 10 parts by mass is used. It is even more preferable to be in.

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

In the composition of the present embodiment, the (meth) acrylate is preferably a monomer from the viewpoint of inkjet ejection property. As for (A), (B) and (C), monomers are particularly preferable. The molecular weight of the monomer is preferably 1000 or less. In terms of inkjet ejection property, the polyfunctional (meth) acrylate oligomer / polymer is preferably contained in an amount of 3 parts by mass or less, preferably 1 part by mass or less, and most preferably not contained in 100 parts by mass of the composition. preferable. The polyfunctional (meth) acrylate oligomer / polymer is one of a group consisting of a polyfunctional (meth) acrylate oligomer, a polyfunctional (meth) acrylate polymer, and a mixture of a polyfunctional (meth) acrylate oligomer and a polyfunctional (meth) acrylate polymer. More than seeds are preferred.

(D) 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. Examples of the photopolymerization 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 ethoxyacetophenone and 4-t-butyltrichloroacetophenone, 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-( 4-Morphorinophenyl) -α-aminoalkylphenone derivative such as butanone-1, benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, benzoyldiethoxyphosphine oxide, 2,4,6-trimethyl Acylphosphine oxide derivatives such as benzoyldimethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiethoxyphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, phenyl-glycylic acid-methyl Examples include esters, oxy-phenyl-acetylic acid 2- [2-oxo-2-phenyl-acetoxy-ethoxy] -ethyl esters and oxy-phenyl-acetylic acid 2- [2-hydroxy-ethoxy] -ethyl esters. Be done. One or more photopolymerization initiators can be used in combination. Among these, the acylphosphine oxide derivative is preferable in that it can be cured 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 by using only light of 395 nm or more without deteriorating the transparency in visible light when used as a display. -Phosphine oxide is most preferred.

The content of the photopolymerization initiator (D) is preferably 0.05 to 6 parts by mass, preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the total of (A), (B) and (C). More preferably, 1 to 4 parts by mass is most preferable. If it is 0.05 part by mass or more, the effect of promoting curing can be surely obtained, and if it is 6 parts by mass or less, the transparency in visible light does not decrease when the display is used.

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 product is 200 ° C. or higher, uneven film formation of the inorganic passion film is caused by thermal expansion when the inorganic passion film is formed on the cured product of the composition of the present embodiment by a method such as CVD. The occurrence of pinholes due to the above is eliminated, and 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 viscoelastic spectrum, and a dynamic viscoelastic 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 set 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, a polymerization inhibitor can be used to improve the storage stability.

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. 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. As energy irradiation sources for irradiating such visible light or ultraviolet rays, deuterium lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, low-pressure mercury lamps, xenon lamps, xenon-mercury mixed lamps, halogen lamps, excimer lamps, etc. Examples thereof include energy irradiation sources such as injume 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 more preferably cured at a wavelength of 395 nm, because it is difficult to damage the organic EL device. 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 short emission wavelength is preferable, and for example, an LED lamp having an emission peak wavelength of 395 nm can be more preferably used.

When the composition is cured by irradiating it with visible light or ultraviolet rays, the composition is cured by irradiating the composition with energy of 100 to 8000 mJ / cm ² at a wavelength of 395 nm. If it is 100 to 8000 mJ / cm ² , the composition is cured and sufficient adhesive strength can be obtained. If it is 100 mJ / cm ² or more, the composition is sufficiently cured, and if it is 8000 mJ / cm ² or less, the organic EL element is not damaged. The amount of energy for 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 as measured by using an E-type viscometer under the conditions of 25 ° C. and 100 rpm. If the viscosity is less than 2 mPa · s, the coated sealant for the organic EL display element may flow out from the organic EL display element before curing. If the viscosity exceeds 50 mPa · s, it may be difficult to apply by inkjet. The viscosity of the composition is preferably 5 mPa · s or more. The viscosity of the composition is preferably 20 mPa · s or less.

The transparency of the composition of the present embodiment is preferably 99% 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 97% or more. The above is more preferable. If it is 97% 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 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 encapsulating substrate is formed in close contact so as to cover the entire upper surface of the uppermost organic film of the encapsulating layer. Examples of this sealing substrate include the above-mentioned substrates. Among these, a substrate that is 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 sealed 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, it is possible to suppress the deterioration that progresses when the surface of the uppermost organic film comes into contact with the 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 patterned in 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 a region surrounded by the banks.

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 a 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. Of these, the inkjet method is preferable. 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, one set of inorganic / organic laminates is formed.

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, even if 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. 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 embodiment of the present embodiment, a sealing layer for blocking the organic EL element formed on the first plastic substrate from the outside air is formed, and a transparent sealing substrate is further formed on the sealing layer. Since the arrangement is made, it is possible to obtain a sealing structure having sufficient barrier properties against water vapor and oxygen for the organic 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, the transparent sealing substrate is placed without curing the composition, and then the transparent sealing substrate is placed. Since the composition 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 constituting 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 permeability value of 250 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 250 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 curability, transparency of a cured product and barrier property. According to the present 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.

(Experimental Examples 1 to 15)
Compositions were prepared and evaluated by the following methods.

(Preparation of composition)
The materials used in Table 1 were used. Each used material was mixed according to the composition shown in Table 2 to prepare a composition. Using the obtained composition, E-type viscosity, moisture permeability, expansion rate of coating area, curing rate, transparency, glass transition temperature, and organic EL evaluation were measured by the evaluation methods shown below. The results are shown in Table 2. The abbreviations shown in Table 1 were used for the composition names in Table 2.

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

[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 with a wavelength of 395 nm by an LED lamp (UV-LED LIGHT SOURCE H-4MLH200-V1 manufactured by HOYA Corporation) 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-mentioned 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 60 ° C. and a relative humidity of 90%.

[Curing rate]
For the composition obtained in each experimental example, the composition was applied to a size of 10 mm × 10 mm on a 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 (Nicolette is5, DTGS detector, resolution 4 cm ^-1 ) manufactured by Thermo Scientific Co., Ltd. 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 polarization vibration of the carbon-hydrogen bond bonded to the carbon-carbon double bond of (meth) acrylate, the following equation is obtained. 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 compositions obtained in each experimental example were formed between two 25 mm × 25 mm × 1 mmt glass plates (non-alkali glass, Corning's Eagle XG) to a thickness of 10 μm, and a wavelength of 395 nm was formed using an LED lamp. A cured product was obtained by irradiating with ultraviolet rays 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 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. The tan δ was measured while raising the temperature from −150 ° C. to 200 ° C., and the temperature at 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. The non-alkali glass was washed with acetone and isopropanol before use, and then washed with a UV ozone cleaning device UV-208 manufactured by Technovision Co., Ltd. for 5 minutes. After the pattern was applied, it was left for 5 minutes under the conditions of an atmospheric temperature of 23 ° C. and a relative humidity of 50%, and the flatness after inkjet application was evaluated by the expansion rate of the applied area (see the following formula). The larger the expansion rate of the coating area, the better the flatness after inkjet coating and the greater the coating property.
(Expansion rate of coating area) = ((contact area of the composition in contact with the surface of the substrate 5 minutes after the pattern is applied) / (contact area of the composition in contact with the surface of the substrate immediately after the pattern is applied)) ) X 100 (%)

[Organic EL evaluation]

[Manufacturing of organic EL element substrate]
The glass substrate with ITO electrode was washed with acetone and isopropanol, respectively. Then, the following compounds were sequentially vapor-deposited into a thin film by a vacuum vapor deposition method to obtain an organic EL element substrate composed of an anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode. The structure of each layer is as follows.
・ Anode ITO, anode film thickness 250 nm
・ Hole injection layer Copper phthalocyanine ・ 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, anode film thickness 250nm

[Manufacturing of organic EL element]
The composition obtained in each experimental example was applied to an organic EL element substrate having a thickness of 10 μm under the above-mentioned inkjet device under a nitrogen atmosphere, and the composition was cured under the above-mentioned photocuring conditions. After that, a mask (cover) having an opening of 4 mm × 4 mm was placed so as to cover the entire cured product, and a SiN film was formed by a plasma CVD method to obtain an organic EL display element. The thickness of the formed SiN was about 1 μm. Then, using a transparent base material-less double-sided tape of 4 mm × 4 mm × 25 μmt, it was bonded to 4 mm × 4 mm × 0.7 mmt of non-alkali glass (Eagle XG manufactured by Corning Inc.) to prepare an organic EL element (organic EL evaluation). ).

〔initial〕
The organic EL element immediately after being manufactured is exposed to the conditions of 85 ° C. and a relative humidity of 85% by mass for 1000 hours, then a voltage of 6 V is applied, and the light emitting state of the organic EL element is visually observed and observed with a microscope. The diameter of the spot was measured.

〔durability〕
The organic EL element immediately after being manufactured is exposed to the conditions of 85 ° C. and a relative humidity of 85% by mass for 1000 hours, then a voltage of 6 V is applied, and the light emitting state of the organic EL element is visually observed and observed with a microscope. The diameter of the spot was measured. The diameter of the dark spot is preferably 300 μm or less, more preferably 50 μm or less, and most preferably no dark spot.

The following was found from the above experimental example.
The present embodiment can provide a composition excellent in ejection property by high-precision inkjet and flatness after inkjet application, and excellent in low moisture permeability, transparency, and durability (including long-term durability). When 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), low moisture permeability and durability (long-term). Excellent (including durability) (Experimental Examples 1 to 4). As (B), when the acyclic bifunctional methacrylate and the acyclic bifunctional acrylate are not used in combination, the expansion rate of the coating area is large and the coating property is excellent (Experimental Examples 5 to 11). When dicyclopentenyloxyethyl (meth) acrylate is used as (C), low moisture permeability is excellent (Experimental Example 6). When the conditions of (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, application by inkjet could not be performed (Experimental Example 13). When (B) was not used, application by inkjet could not be performed (Experimental Example 14). When (A) was not used, low moisture permeability and long-term durability could not be obtained (Experimental Example 15).

The composition of the present embodiment is excellent in ejection property by high-precision inkjet and flatness after inkjet application, 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 suitably applied to adhesion of electronic products, particularly display parts such as organic EL, electronic parts such as image sensors such as CCD and CMOS, and element packages used in semiconductor parts and the like. can. In particular, it is most suitable for bonding for organic EL encapsulation, and satisfies the characteristics required for an adhesive for an element package such as an organic EL element.

The above composition is one aspect of the present embodiment, and the adhesive of the present embodiment, the sealant for an organic EL element, a cured product, a covering body, a bonded body, an organic EL device, a display, a method for producing them, and the like are also included. It has a similar configuration and effect.

Claims (21)

(A) trifunctional or higher functional acyclic polyfunctional (meth) acrylate, (B) acyclic acyclic diol di (meth) acrylate having 6 or more and 12 or less carbon atoms, (C) alkyl (meth) having 8 or more carbon atoms . ) An adhesive composition containing (D) a photopolymerization initiator, which is one or more selected from the group consisting of an acrylate and a (meth) acrylate having an alicyclic hydrocarbon group , (A) and (B). , (C) contains 3 to 70 parts by mass, (B) 15 to 95 parts by mass, and (C) 2 to 40 parts by mass in a total of 100 parts by mass.
(B) An adhesive composition containing acyclic alkanediol dimethacrylate and acyclic alkanediol diacrylate in a mass ratio of 10 to 90: 90 to 10. (A) trifunctional or higher functional acyclic polyfunctional (meth) acrylate, (B) acyclic acyclic diol di (meth) acrylate having 6 or more and 12 or less carbon atoms, (C) alkyl (meth) having 8 or more carbon atoms . ) An adhesive composition containing (D) a photopolymerization initiator, which is one or more selected from the group consisting of an acrylate and a (meth) acrylate having an alicyclic hydrocarbon group , (A) and (B). , (C) contains 3 to 10 parts by mass, (B) 85 to 95 parts by mass, and (C) 2 to 10 parts by mass in a total of 100 parts by mass.
(B) An adhesive composition containing acyclic alkanediol dimethacrylate and acyclic alkanediol diacrylate in a mass ratio of 10 to 90: 90 to 10. The adhesive composition according to claim 1 or 2, which contains 0.05 to 6 parts by mass of (D) with respect to a total of 100 parts by mass of (A), (B) and (C). The adhesive composition according to any one of claims 1 to 3, wherein the viscosity measured by an E-type viscometer at 25 ° C. is 2 mPa · s or more and 50 mPa · s or less. The adhesive composition according to any one of claims 1 to 4, which does not contain a polyfunctional (meth) acrylate oligomer / polymer. An adhesive composition having a glass transition temperature of a cured product obtained from the adhesive composition according to any one of claims 1 to 5 of 200 ° C. or higher. The adhesive composition according to any one of claims 1 to 6, wherein (A) is trimethylolpropane tri (meth) acrylate. (B) is one or more of the group consisting of 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, and 1,12-dodecanediol di (meth) acrylate. The adhesive composition according to any one of claims 1 to 7 . The adhesive composition according to any one of claims 1 to 8 , wherein (C) is lauryl (meth) acrylate. The adhesive composition according to any one of claims 1 to 9 , wherein (C) contains a monofunctional methacrylate and a monofunctional acrylate. The adhesive composition according to any one of claims 1 to 10 , wherein (D) is an acylphosphine oxide derivative. A cured product obtained by curing the adhesive composition according to any one of claims 1 to 11 . A covering body coated with the adhesive composition according to any one of claims 1 to 11 . A bonded body bonded with the adhesive composition according to any one of claims 1 to 11 . The method for curing an adhesive composition according to any one of claims 1 to 11 , wherein the adhesive composition is cured at a wavelength of 380 nm or more and 500 nm or less. The method for curing an adhesive composition according to any one of claims 1 to 11 , which is cured by an LED lamp having an emission peak wavelength of 395 nm. The method for applying an adhesive composition according to any one of claims 1 to 11 , wherein the adhesive composition is applied by using an inkjet method. An organic EL device including the cured product according to claim 12 . A display comprising the cured product according to claim 12 . (A) trifunctional or higher acyclic polyfunctional (meth) acrylate, (B) acyclic acyclic diol di (meth) acrylate having 6 or more and 12 or less carbon atoms, (C) alkyl (meth) having 8 or more carbon atoms . ) An adhesive composition containing (D) a photopolymerization initiator, which is one or more selected from the group consisting of an acrylate and a (meth) acrylate having an alicyclic hydrocarbon group , (A) and (B). , (C) contains 1 to 70 parts by mass, (B) 15 to 98 parts by mass, and (C) 1 to 40 parts by mass in a total of 100 parts by mass.
(B) An adhesive composition containing acyclic alkanediol dimethacrylate and acyclic alkanediol diacrylate in a mass ratio of 10 to 90: 90 to 10. (A) trifunctional or higher functional acyclic polyfunctional (meth) acrylate, (B) acyclic acyclic diol di (meth) acrylate having 6 or more and 12 or less carbon atoms, (C) alkyl (meth) having 8 or more carbon atoms . ) An adhesive composition containing (D) a photopolymerization initiator, which is one or more selected from the group consisting of an acrylate and a (meth) acrylate having an alicyclic hydrocarbon group , (A) and (B). , (C) contains 1 to 10 parts by mass, (B) 85 to 98 parts by mass, and (C) 1 to 10 parts by mass in a total of 100 parts by mass.
(B) An adhesive composition containing acyclic alkanediol dimethacrylate and acyclic alkanediol diacrylate in a mass ratio of 10 to 90: 90 to 10.