JPWO2019203071A1 - Encapsulant for organic electroluminescence display elements - Google Patents

Abstract

It contains (A) an alkanediol di (meth) acrylate having 4 to 20 carbon atoms and (B) a photopolymerization initiator, and has a hydrophilic functional group amount per (meth) acrylate of 4.80 to 7.60 mmol /. A sealant for organic electroluminescence display elements in the range of g.

Description

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

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

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

An organic electroluminescence display element (see Patent Document 2) characterized in that the sealing layer is a laminate in which at least a barrier layer, a resin layer, and a barrier layer are sequentially formed, and an inorganic film and an organic film for sealing an organic EL element. Includes 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, an organic electroluminescence display element encapsulant containing a cyclic ether compound, a cationic polymerization initiator, and a polyfunctional vinyl ether compound (see Patent Document 4), cationically polymerizable. A cationically polymerizable resin composition containing a compound and a photocationic polymerization initiator or a thermal cationic polymerization initiator has been proposed (see Patent Document 5). As a resin composition for encapsulating an organic EL element, a (meth) acrylic resin composition has been proposed (Patent Documents 6 to 14).

Japanese Unexamined Patent Publication No. 10-74583 JP 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 WO2014 / 157642A US2017 / 0062762 Special Table 2017-536429 Special Table 2018-504735 WO2016 / 068415

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

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

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

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

Patent Documents 6 to 10 and 12 to 14 describe that the water vapor transmittance is reduced as a characteristic required for such a sealing material, but the sealing material itself permeates through the pinholes of the passivation membrane. , There is no description about the problem of lowering the reliability of the organic EL element and its countermeasure.

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

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

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

That is, in the embodiment of the present invention, the following can be provided.

[1]
It contains (A) an alkanediol di (meth) acrylate having 4 to 20 carbon atoms and (B) a photopolymerization initiator, and has a hydrophilic functional group amount per (meth) acrylate of 4.80 to 7.60 mmol /. A sealant for an organic electroluminescence display element in the range of g.

[2]
(C) Further contains (meth) acrylate other than the component (A), and the component (A) is 30 parts by mass or more and less than 100 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (C). The sealant for an organic electroluminescence display element according to [1], which contains 0.05 to 6 parts by mass of the component (B) and more than 0 parts by mass and 70 parts by mass or less of the component (C).

[3]
(C) The sealant for an organic electroluminescent display element according to [2], wherein the amount of hydrophilic functional groups per (meth) acrylate in the component is 3,000 to 15.00 mmol / g.

[4]
The sealant for an organic electroluminescence display element 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 encapsulant for an organic electroluminescence display element according to any one of [1] to [4], which has a water content of 90 ppm or less.

[6]
The encapsulant for an organic electroluminescence display element according to any one of [1] to [5], wherein the amount of dissolved oxygen is 1 ppm or more and 20 ppm or less.

[7]
The encapsulant for an organic electroluminescent display element according to any one of [1] to [6], which does not contain a bifunctional (meth) acrylate oligomer / polymer and a polyfunctional (meth) acrylate oligomer / polymer.

[8]
The encapsulant for an organic electroluminescence display element according to any one of [1] to [7], wherein the component (A) is an alkanediol di (meth) acrylate having 12 or more and 16 or less carbon atoms.

[9]
The encapsulant for an organic electroluminescence display element according to any one of [1] to [8], wherein the component (A) is 1,12-dodecanediol di (meth) acrylate.

[10]
The component (C) is one or more of the group consisting of an alkyl (meth) acrylate having 8 or more carbon atoms, a (meth) acrylate having an alicyclic hydrocarbon group, and a (meth) acrylate having an aromatic hydrocarbon group. The encapsulant for an organic electroluminescence display element according to any one of [2] to [9].

[11]
The encapsulant for an organic electroluminescence display element according to any one of [2] to [10], wherein the component (C) contains lauryl (meth) acrylate.

[12]
The component (C) is dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and dicyclopentanyloxy. The encapsulant for an organic electroluminescence display element according to any one of [2] to [11], which contains at least one of the group consisting of ethyl (meth) acrylate.

[13]
The encapsulant for an organic electroluminescence display element according to any one of [2] to [12], wherein the component (C) contains an ethoxylated-o-phenylphenol (meth) acrylate.

[14]
The encapsulant for an organic electroluminescence display element according to any one of [1] to [13], wherein the component (B) is an acylphosphine oxide derivative.

[15]
A cured product obtained by curing the sealant for an organic electroluminescence display element according to any one of [1] to [14].

[16]
A bonded body bonded with the sealant for an organic electroluminescence display element according to any one of [1] to [14].

[17]
The method for curing an organic electroluminescence display element sealing agent according to any one of [1] to [14], which comprises curing using a wavelength of 380 nm or more and 500 nm or less.

[18]
The method for curing an organic electroluminescence display element sealing agent according to any one of [1] to [14], which comprises curing using an LED lamp having an emission wavelength of 395 nm.

[19]
The method for applying a sealing agent for an organic electroluminescence display element according to any one of [1] to [14], which is applied by using an inkjet method.

[20]
An organic EL device containing the sealant for an organic electroluminescence display element according to any one of [1] to [14].

[21]
A display containing the sealant for an organic electroluminescence display element according to any one of [1] to [14].

The encapsulant according to the present invention has the effects of being excellent in ejection property when using an inkjet, and also in excellent reliability, coatability, and low moisture permeability of the obtained organic EL element.

Hereinafter, this embodiment will be described.
The present embodiment relates to a sealant for an organic electroluminescence display element. The present embodiment relates to a (meth) acrylic resin composition that can be used, for example, as a sealant for an organic electroluminescence (EL) display element.

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

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

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

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

As the anode, a conductive metal oxide film, a translucent metal thin film, or the like having a relatively large work function (preferably one having a work function larger than 4.0 eV) is generally used. Examples of the material of the anode include indium tin oxide (hereinafter referred to as ITO), metal oxides such as tin oxide, gold (Au), platinum (Pt), silver (Ag), copper (Cu) and the like. Examples thereof include organic transparent conductive films such as metals of the above, alloys containing at least one of them, polyaniline or derivatives thereof, polythiophene or derivatives thereof, and the like. 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 electrical conductivity (in the case of the bottom emission type, the light transmission). The film thickness of the anode is preferably 10 nm to 10 μm, more preferably 20 nm to 1 μm, and most preferably 50 nm to 500 nm. Examples of the method for producing the anode include a vacuum 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 organic substances include pigment-based materials, metal complex-based materials, and polymer materials. The dopant material is doped in the organic substance for the purpose of improving the luminous efficiency of the organic substance and changing the emission wavelength. The thickness of the light emitting layer composed of these organic substances and a dopant that is optionally doped is 2 to 200 nm.

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

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

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

Among the above-mentioned luminescent materials, examples of the material that emits blue light include 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 polyvinylcarbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives is preferable.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

The organic film of the inorganic / organic laminate is provided to provide flatness to the surface in order to cover defects such as pinholes formed on the inorganic film. The organic film is formed in a region narrower than the region where the inorganic film is formed. This is because if the organic film is formed 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 good adhesion to the above-mentioned inorganic film is used.

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

The viscosity of the composition of the present embodiment is preferably 2 mPa · s or more and 50 mPa · s or less, which is measured under the conditions of 25 ° C. and 100 rpm using an E-type viscometer. If it is difficult to eject by inkjet, heat the inkjet head as appropriate. When the viscosity is 2 mPa · s or more, the coated sealant for the organic EL display element does not flow out from the organic EL display element before curing and does not flow into the pinhole on the inorganic film, and the reliability of the OLED element. Is improved. When the viscosity is 50 mPa · s or less, application by inkjet becomes easy. The viscosity of the composition is more preferably 5 mPa · s to 30 mPa · s.

The composition of the present embodiment is a (meth) acrylic resin composition containing (A) an alkanediol di (meth) acrylate having 4 or more and 20 or less carbon atoms and (B) a photopolymerization initiator. In this specification, when the carbon number is described for the main chain (alkanediol, etc.), the carbon number of the (meth) acrylate portion is not included.

(A) Examples of the alkane of the alkanediol di (meth) acrylate having 4 or more and 20 or less carbon atoms include a chain compound and a cyclic compound. As the alkane, a chain compound is preferable. The chain compound may be a linear compound or a split chain compound. Saturated hydrocarbons are preferred as alkanes.

(A) Examples of the alkanediol di (meth) acrylate having 4 or more and 20 or less carbon atoms (alkane is a chain compound and saturated hydrocarbon) include 1,2-butanediol di (meth) acrylate and 1,3-butanediol di. (Meta) acrylate, 1,4-butanediol di (meth) acrylate, 1,5-pentanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,7-heptanediol di (meth) acrylate ) Acrylate, 1,7-octanediol di (meth) acrylate, 1,8-octanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate , 1,11-Undecanediol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, 1,13-tridecanediol di (meth) acrylate, 1,14-tetradecanediol di (meth) acrylate, 1,15-Pentadecanediol di (meth) acrylate, 1,16-hexadecanediol di (meth) acrylate, 1,17-heptadecanediol di (meth) acrylate, 1,18-octadecanediol di (meth) acrylate, 1 , 19-Nonadecanediol di (meth) acrylate, 1,20-icosandiol di (meth) acrylate, 3-methyl-1,5-pentanediol di (meth) acrylate, 2,4-diethyl-1,5 -Pentanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate and the like can be mentioned. (A) Examples of the alkanediol di (meth) acrylate having 4 to 20 carbon atoms (alkane is a cyclic compound) include 1,2-cyclohexanediol di (meth) acrylate and 1,3-cyclohexanediol di (meth) acrylate. , 1,4-Cyclohexanediol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, hydrogenated bisphenol A di (meth) acrylate and the like. Among alkanediol di (meth) acrylates having 4 to 20 carbon atoms, it is better to have a large number of carbon atoms in the main chain from the viewpoint of reliability of the OLED device, but the composition may crystallize during storage. The problem of storage stability arises, such as the formation of crystallized products. From the viewpoint of reliability, moisture permeability, and storage stability of the OLED device, the number of carbon atoms is preferably 6 or more and 18 or less, more preferably 9 or more and 16 or less, even more preferably 12 or more and 16 or less, and most preferably 12. Among the components (A), 1,12-dodecanediol di (meth) acrylate is preferable. Examples of the component (A) include the product name "1.9ND-A" manufactured by Kyoeisha Chemical Co., Ltd. and the product name "SR262" manufactured by Sartmer Co., Ltd.

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

The content of the photopolymerization initiator (B) is preferably 0.05 to 6 parts by mass, preferably 0.5 to 6 parts by mass, based on 100 parts by mass of the total of the component (A) and the component (C) used as needed. 4 parts by mass is more preferable, 2 to 3.9 parts by mass is most preferable, and 2.2 to 3.5 parts by mass is even more preferable. If the content of the component (C) is 0.05 parts by mass or more, the effect of promoting curing can be surely obtained, and if it is 6 parts by mass or less, the transparency in visible light decreases when used for a display. There is nothing to do.

（前記式において、材料とは各（メタ）アクリレート成分のことをいう）

（前記式において、材料とは各（メタ）アクリレート成分のことをいう）

上記親水性官能基量が４．８０ｍｍｏｌ／ｇ以上だと、反応性基である（メタ）アクリロイル基が多いため、反応性が高くなり、有機ＥＬ素子の封止性能を満足に発現し、低透湿性になるため有機ＥＬ素子の信頼性が向上し、平坦性が良くなる。７．６０ｍｍｏｌ／ｇ以下だと、信頼性試験中に有機エレクトロルミネッセンス表示素子用封止剤内部から水分が放出されにくく、有機発光材料層に水分が到達せず、ダークスポットが発生しにくい。反応性と信頼性の観点から、４．８０〜７．６０ｍｍｏｌ／ｇが好ましく、５．００〜７．１０ｍｍｏｌ／ｇがより好ましい。In the (meth) acrylic resin composition of the present embodiment, it is essential that the amount of hydrophilic functional groups per (meth) acrylate contained is 4.80 to 7.60 mmol / g. The amount of hydrophilic functional groups in the (meth) acrylic resin composition is calculated by the following formula for the amount of hydrophilic functional groups per (meth) acrylate of the component (A) and the component (C) if present. The product of the amount of hydrophilic functional groups of each material multiplied by the mass fraction of each material shown in the following formula blended in the (meth) acrylic resin composition is calculated, and the total is calculated as (meth) acrylic. The amount of hydrophilic functional groups of the based resin composition was used. In calculating the mass fraction in the material, the total amount of (meth) acrylate was set to 100 parts by mass.

(In the above formula, the material means each (meth) acrylate component)

(In the above formula, the material means each (meth) acrylate component)

When the amount of the hydrophilic functional group is 4.80 mmol / g or more, the reactivity is high because there are many (meth) acryloyl groups which are reactive groups, and the sealing performance of the organic EL device is satisfactorily exhibited and low. Since it becomes moisture permeable, the reliability of the organic EL element is improved and the flatness is improved. If it is 7.60 mmol / g or less, it is difficult for water to be released from the inside of the sealant for the organic electroluminescence display element during the reliability test, the water does not reach the organic light emitting material layer, and dark spots are unlikely to occur. From the viewpoint of reactivity and reliability, 4.80 to 7.60 mmol / g is preferable, and 5.00 to 7.10 mmol / g is more preferable.

This embodiment preferably contains a (meth) acrylate other than the component (A) as the component (C). As the component (C), one or more of the group consisting of monofunctional (meth) acrylate, bifunctional (meth) acrylate, and polyfunctional (meth) acrylate can be used. By using the component (C), the amount of hydrophilic functional groups in the composition can be adjusted, and the viscosity, inkjet coatability, and moisture permeability can also be adjusted.

Here, the hydrophilic functional group means an atom having a maximum difference in electronegativity of 0.6 or more among the atoms constituting the functional group. Such hydrophilic functional groups include (meth) acryloyl groups, ester groups, aldehyde groups, nitro groups, hydroxyl groups, ethylene oxide groups, propylene oxide groups, ether groups, amide groups, cyclic amide groups, sulfoxide groups, carbonyl groups, etc. A group consisting of a carboxylic acid (salt) group, a sulfonic acid (salt) group, a sulfinic acid (salt) group, a phosphonic acid (salt) group, a phosphoric acid (salt) group, a sulfobetaine group, a carbobetaine group, and a phosphobetaine group. One or more is preferable.

Examples of the monofunctional (meth) acrylate of the component (C) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and isooctyl (meth). Alkyl (meth) acrylates such as acrylates, isodecyl (meth) acrylates, lauryl (meth) acrylates, stearyl (meth) acrylates, benzyl (meth) acrylates, 4-butylphenyl (meth) acrylates, phenyl (meth) acrylates, 2, 4,5-Tetramethylphenyl (meth) acrylate, 4-chlorophenyl (meth) acrylate, phenoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate (2-HPA) ), 2- (Meta) acryloyloxyhexahydrophthalic acid, 2- (meth) acryloyloxyethyl-2-hydroxypropylphthalic acid, EO (ethylene oxide) modified phenol (meth) acrylate, EO modified cresol (meth) Acrylate, EO-modified nonylphenol (meth) acrylate, PO (propylene oxide) -modified nonylphenol (meth) acrylate, ethoxylated-o-phenylphenol (meth) acrylate, m-phenoxybenzyl (meth) acrylate, 2-hydroxy-3-phenoxy Propyl (meth) acrylate, phenolethylene oxide modified (meth) acrylate, phenol (ethylene oxide 2 mol modified) (meth) acrylate, phenol (ethylene oxide 4 mol modified) (meth) acrylate, paracumylphenol ethylene oxide modified (meth) Acrylate, nonylphenol ethylene oxide modified (meth) acrylate, nonylphenol (4 mol modified ethylene oxide) (meth) acrylate, nonylphenol (8 mol modified ethyleneoxide) (meth) acrylate, nonylphenol (2.5 mol modified propylene oxide) (meth) One or more aromatic hydrocarbon-based cyclic structures (hereinafter, also referred to as aromatic hydrocarbon groups) in the molecule such as acrylate, ethylene oxide-modified phthalic acid (meth) acrylate, and monohydroxyethyl (meth) phthalate. ) Monofunctional (meth) acrylate, cyclohexyl (meth) acrylate, dicyclo Pentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, methoxylated cyclodecatrine (meth) acrylate Etc., an aliphatic hydrocarbon-based cyclic structure (hereinafter, may also be referred to as an alicyclic hydrocarbon group. ), Monofunctional (meth) acrylate, methoxylated cyclodecatriene (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxy Butyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, glycidyl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, N, N-dimethylaminoethyl (Meta) acrylate, N, N-diethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, ethoxycarbonylmethyl (meth) acrylate, 2-ethylhexyl carbitol (meth) acrylate, ethylene oxide-modified succinic acid (meth) ) Acrylate, trifluoroethyl (meth) acrylate, (meth) acrylic acid, maleic acid, fumaric acid, ω-carboxy-polycaprolactone mono (meth) acrylate, (meth) acrylic acid dimer, β- (meth) acroyloxy Examples thereof include ethyl hydrogen succinate, n- (meth) acryloyloxyalkyl hexahydrophthalimide, 2- (1,2-cyclohexacarboxyimide) ethyl (meth) acrylate and the like. As the monofunctional (meth) acrylate of the component (C), a (meth) acrylate having a cyclic structure such as a heterocyclic structure containing a cyclic amide group, a tetrahydrofurfuryl group, a piperidinyl group and the like can be used.

Examples of the bifunctional (meth) acrylate of the component (C) include dicyclopentanyldi (meth) acrylate, 2-ethyl-2-butyl-propanediol (meth) acrylate, and neopentyl glycol-modified trimethylolpropane di (meth). Acrylate, stearic acid-modified pentaeristoldi (meth) acrylate, polypropylene glycol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, 2,2-bis (4- (meth) acryloxidiethoxyphenyl) Propane, 2,2-bis (4- (meth) acryloxipropoxyphenyl) propane, 2,2-bis (4- (meth) acryloxitetraethoxyphenyl) propane, 2- (1,2-cyclohexacarboxyimide) ) Ethyl (meth) acrylate, bisphenol A epoxy di (meth) acrylate and the like can be mentioned. Examples of the bifunctional (meth) acrylate of the component (C) include an ethoxylated bisphenol A di (meth) acrylate compound represented by the following structural formula, a propoxylated bisphenol A di (meth) acrylate, and a propoxylated ethoxylated bisphenol A di (meth) acrylate. Meta) acrylate and the like can be mentioned.
R in the following formula is independently a hydrogen atom or a methyl group. With respect to m and n in the formula, m + n = 2 to 10 is preferable.

Examples of the polyfunctional (meth) acrylate of the component (C) include trimethylolpropane tri (meth) acrylate, tris [(meth) acryloyloxyethyl] isocyanurate, dimethylolpropane tetra (meth) acrylate, and pentaerythritol tetra (meth). ) Acrylate, pentaerythritol ethoxytetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like can be mentioned.

The amount of hydrophilic functional groups of the component (C) is preferably 3.00 to 15.00 mmol / g. When the amount of hydrophilic functional groups is 3.00 to 15.00 mmol / g, sufficient reactivity and reliability of the OLED device can be ensured. From the viewpoint of reactivity and reliability of the OLED device, the amount of hydrophilic functional groups of the component (C) is preferably 4.00 to 15.00 mmol / g, more preferably 4.1 to 8.20 mmol / g, and 4.20. ~ 7.60 mmol / g is even more preferable.

In terms of reactivity, reliability of the OLED element, and inkjet coating property, the component (C) is an alkyl (meth) acrylate having 8 or more carbon atoms, a (meth) acrylate having an alicyclic hydrocarbon group, and an aromatic hydrocarbon. It is preferably one or more of the group consisting of (meth) acrylates having a group. As the alkyl (meth) acrylate having 8 or more carbon atoms, one or more of the group consisting of isooctyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate is preferable, and lauryl (meth) acrylate is preferable. Acrylate is most preferred. 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. One or more of the group consisting of cyclopentenyloxyethyl (meth) acrylate, isobornyl (meth) acrylate, and tricyclodecanedimethanol di (meth) acrylate is preferable, and dicyclopentanyl (meth) acrylate and dicyclopentanyloxyethyl are preferable. More preferably, one or more of the group consisting of (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and dicyclopentanyloxyethyl (meth) acrylate. As the (meth) acrylate having an aromatic hydrocarbon group, ethoxylated-o-phenylphenol (meth) acrylate is preferable.

The content of the component (A) is preferably 30 to 100 parts by mass, more preferably 30 parts by mass or more and less than 100 parts by mass, based on 100 parts by mass of the total of the component (A) and the component (C). When the content of (A) is 30 parts by mass or more, the inkjet coatability, low moisture permeability, and reliability of the organic EL element are excellent. In terms of inkjet coatability, low moisture permeability, and reliability of the organic EL element, 55 to 99 parts by mass is preferable, 60 to 95 parts by mass is more preferable, and 65 to 95 parts by mass is further preferable.

The content of the component (C) when present is preferably more than 0 parts by mass and 70 parts by mass or less with respect to 100 parts by mass in total of the component (A) and the component (C). When the content of the component (C) is 70 parts by mass or less, the inkjet coatability, low moisture permeability, and reliability of the organic EL element are excellent. The content of the component (C) is preferably 1 to 45 parts by mass, more preferably 5 to 40 parts by mass, and further 5 to 35 parts by mass in terms of inkjet coatability, low moisture permeability, and reliability of the organic EL element. preferable.

As described above, since the OLED element is easily deteriorated by moisture, it is preferable that the composition of the present embodiment has a small water content. From the viewpoint of reliability of the OLED element, the water content is preferably 90 ppm or less, more preferably 50 ppm or less, and even more preferably 30 ppm or less.

Such water content can be measured using a commercially available water content meter, but it is common to use a Karl Fischer water content meter.

The method for reducing the water content is not particularly limited, and examples thereof include the following methods.

(1) Remove water with a desiccant. After removing the water, the desiccant is separated by decantation or filtration. The desiccant is not particularly limited as long as it does not affect the resin composition, but is not particularly limited, but is a polymer adsorbent (molecular sieve, synthetic zeolite, alumina, silica gel, etc.), an inorganic salt (calcium chloride, anhydrous magnesium sulfate, fresh lime, anhydrous sodium sulfate, etc.). , Anhydrous calcium sulfate, etc.), solid alkalis (sodium hydroxide, potassium hydroxide, etc.) and the like. (2) Heat under reduced pressure conditions to remove water. (3) Distillation and purification under reduced pressure conditions. (4) An inert gas such as dry nitrogen or dry argon gas is blown into each component to remove water. (5) Moisture is removed by freeze-drying.

To reduce the water content, the water content may be reduced for each component before mixing, or the water content may be reduced after mixing each component. One or more types of water content reduction steps may be used. After the step of reducing the amount of water, it is preferable to handle the product in an inert gas atmosphere in order to prevent re-mixing of water.

Further, as described above, since the OLED element is easily deteriorated by oxygen, it is preferable that the amount of dissolved oxygen is small in the composition of the present embodiment. From the viewpoint of reliability of the OLED element, the amount of dissolved oxygen is preferably 20 ppm or less, more preferably 10 ppm or less. On the other hand, dissolved oxygen reacts with active radicals generated from the composition to generate inactive peroxide radicals, which has the effect of suppressing thickening due to polymerization of the composition, and thus has storage stability. From the point of view, 1 ppm or more is preferable, and 2 ppm or more is more preferable.

Such a dissolved oxygen amount can be measured by a titration method using a reagent, a diaphragm electrode method using a diaphragm, a fluorescence method using a fluorescent substance, or the like. The measuring method is not particularly limited, but the diaphragm electrode method is convenient and preferable.

The method for reducing the amount of dissolved oxygen is not particularly limited, and examples thereof include the following methods.

(1) Exposure under reduced pressure conditions to remove oxygen. (2) An inert gas such as dry nitrogen or dry argon gas is blown into each component to remove oxygen. (3) Oxygen is removed by exposure to low oxygen concentration.

To reduce the amount of dissolved oxygen, oxygen may be reduced for each component before mixing, or oxygen may be reduced after mixing each component. One or more kinds of steps for reducing the amount of dissolved oxygen may be used. After the step of reducing the amount of dissolved oxygen, it is preferable to handle it in an inert gas atmosphere in order to prevent re-mixing of oxygen.

In the composition of the present embodiment, the (meth) acrylate is preferably a monomer from the viewpoint of inkjet ejection property. As the component (A) and the component (C), a monomer is preferable. The molecular weight of the monomer is preferably 1000 or less. In terms of inkjet ejection property, the bifunctional (meth) acrylate oligomer / polymer and the polyfunctional (meth) acrylate oligomer / polymer are 3 in 100 parts by mass of the (meth) acrylate containing the component (A) and the component (C). It is preferably contained in an amount of 1 part by mass or less, more preferably contained in an amount of 1 part by mass or less, and most preferably not contained. Oligomer / polymer refers to one or more of the group consisting of oligomers and polymers. The molecular weight of the oligomer / polymer is preferably greater than 1000.

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

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

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

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

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

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

The sealing layer made of the composition of the present embodiment is preferably 1 to 5 sets when the inorganic / organic laminate is counted as one set. This is because when the number of inorganic / organic laminates is 6 or more, the sealing effect on the organic EL element is almost the same as that of 5 sets. The thickness of the inorganic film of the inorganic / organic laminate is preferably 50 nm to 1 μm. The thickness of the organic film of the inorganic / organic laminate is preferably 1 to 15 μm, more preferably 3 to 10 μm. When the thickness of the organic film is 1 μm or more, the particles generated during device formation can be completely covered and can be applied on the inorganic film while ensuring flatness. When the thickness of the organic material film is 15 μm or less, water does not penetrate from the side surface of the organic material film, and the reliability of the organic EL element is improved.

The sealing substrate is formed in close contact so as to cover the entire upper surface of the uppermost organic film of the sealing layer. Examples of this sealing substrate include the above-mentioned substrates. Of 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 sealing substrate is preferably 1 μm or more and 1 mm or less, more preferably 10 μm or more and 800 μm or less, and most preferably 50 μm or more and 300 μm or less. By providing the transparent sealing substrate on the upper layer of the sealing layer, it is possible to suppress deterioration that progresses when the surface of the uppermost organic film comes into contact with a gas, and it is possible to enhance the barrier property of the organic EL device.

Next, a method of manufacturing an organic EL device having such a configuration will be described. First, an anode, an organic EL layer including a light emitting layer, and a cathode, which are patterned 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 the organic EL device is used as a dot matrix display device, a bank is formed to divide the light emitting region into a matrix, and an organic EL layer including a light emitting layer is formed in the region surrounded by the bank.

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

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

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

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

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

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

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

According to the present embodiment, after the composition of the present embodiment constituting the uppermost organic film of the sealing layer is adhered, a transparent sealing substrate is placed without curing the composition, and then the composition is formed. Since the material is cured, it is possible to bond the sealing layer and the transparent sealing substrate at the same time as forming the uppermost organic film 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 permeation value of 350 g / m at a thickness of 100 μm measured by exposing the cured product to an environment of 85 ° C. and 85% RH for 24 hours in accordance with JIS Z 0208: 1976. It is preferably m ^{2 or less.} When the moisture permeability is 350 g / m ² or less, moisture does not reach the organic light emitting material layer, and dark spots are unlikely to occur.

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

(Experimental Examples 1 to 17)
Compositions were prepared and evaluated by the following methods.

(Preparation of composition)
The materials used in Table 1 were used. After mixing the materials used in the composition shown in Table 2, dehydrate them with a molecular sieve (5A pellets manufactured by Union Showa Co., Ltd.), and then expose the composition to a glove box having an oxygen concentration of 5 ppm or less for 72 hours or more. Prepared. Using the obtained composition, the E-type viscosity, water content, dissolved oxygen content, moisture permeability, coating area expansion rate, curing rate, transparency, and organic EL evaluation were measured by the evaluation methods shown below. rice field. 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 (cone plate type: cone angle 1 ° 34', cone rotor radius 24 mm) under the conditions of a temperature of 25 ° C. and a rotation speed of 100 rpm.

[Water content]
The water content of the composition was measured by using Aquamicron AX (manufactured by Mitsubishi Chemical Co., Ltd.) as a Karl Fischer solution and using a trace water content measuring device CA-06 (manufactured by Mitsubishi Chemical Co., Ltd.).

[Dissolved oxygen amount]
The amount of dissolved oxygen in the composition was measured using a dissolved oxygen meter (manufactured by Iijima Denshi Kogyo Co., Ltd., trade name "DO meter B-506 (diaphragm type galvanic cell type)").

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

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

An infrared spectroscope (Nicolet is5 manufactured by Thermo Scientific Co., Ltd., DTGS detector, resolution 4 cm ^-1 ) was used for the composition after curing and the composition before curing, and infrared light was applied to the measurement sample. The infrared spectroscopic spectrum was measured after incident. In the obtained infrared spectroscopic spectrum, the expansion and contraction vibration peak of the carbon-hydrogen bond of the methylene group observed near ^{2950 cm -1} , which does not cause a peak change before and after curing, is used as the internal standard, and before and after curing of this internal standard. From the peak area and the area before and after curing of the peak near ^{810 cm -1} , which is attributed to the peak of the out-of-plane angle vibration of the carbon-hydrogen bond bonded to the carbon-carbon double bond of (meth) acrylate, the following equation The curing rate was calculated using.
Curing rate (%) = [1- (Ax / Bx) / (Ao / Bo)] x 100
here,
Ao: Represents the peak area before curing near ^{810 cm -1.}
Ax: Represents the peak area after curing near ^{810 cm -1.}
Bo: Represents the peak area before curing near ^{2950 cm -1.}
Bx: Represents the peak area after curing near ^{2950 cm -1.}

〔transparency〕
The compositions obtained in each experimental example were formed between two 25 mm × 25 mm × 1 mmt (mm thickness) glass plates (non-alkali glass, Corning's Ultra XG) to a thickness of 10 μm, and an LED lamp was used. Then, it was cured by irradiating it with ultraviolet rays having a wavelength of 395 nm so that the irradiation amount was 1500 mJ / cm ^{2, and a cured product was obtained.} 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.

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

[Organic EL evaluation]

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

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

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

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

〔durability〕
The organic EL device immediately after production is exposed for 500 hours under the conditions of 85 ° C. and 85% by mass relative humidity, then a voltage of 6 V is applied, and the light emitting state of the organic EL device is visually and microscopically observed to be dark. The diameter of the spot was measured.

The diameter of the dark spot can be regarded as an index for evaluating the degree of penetration of the sealant into the pinholes of the passivation film and the degree of water discharged as outgas in the sealant. The diameter of the dark spot was evaluated as 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 composition according to the present embodiment can provide a composition excellent in reliability of an organic EL element, high-precision inkjet ejection property, shape retention after inkjet application, and low moisture permeability.

It contains an alkanediol di (meth) acrylate having 4 or more carbon atoms and 20 or less carbon atoms as the component (A) and a photopolymerization initiator as the component (B), and the amount of hydrophilic functional groups per (meth) acrylate is 4.80 to. When the condition of 7.60 mmol / g was satisfied, reliability, inkjet ejection property, flatness after coating, and low moisture permeability were excellent. The diameter of the dark spots generated at the initial stage was also small (Experimental Examples 1 to 12).

On the other hand, when the amount of the hydrophilic functional group does not satisfy the range of 4.80 to 7.60 mmol / g, not only the diameter of the dark spot generated at the initial stage is large, but also the moisture permeability is high and there is a problem in reliability. There were (Experimental Examples 13 to 17).

Further, when an alkanediol di (meth) acrylate having 4 or more carbon atoms and 20 or less carbon atoms is not used, not only the expansion ratio of the coating area is small, there is a problem in inkjet ejection property and flatness after coating, but also the moisture permeability is high. There was a problem with reliability (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 adhesion for sealing organic EL, and satisfies the characteristics required for an adhesive for element packaging such as an organic EL element.

The above composition is one aspect of the present embodiment, and is an encapsulant for an organic EL device, a cured product, a coating body, a bonded body, an organic EL device, a display, and production thereof using the composition according to the present embodiment. The method and the like have the same configuration and effect.

Claims (21)

It contains (A) an alkanediol di (meth) acrylate having 4 to 20 carbon atoms and (B) a photopolymerization initiator, and has a hydrophilic functional group amount per (meth) acrylate of 4.80 to 7.60 mmol /. A sealant for an organic electroluminescence display element in the range of g. (C) Further contains (meth) acrylate other than the component (A), and the component (A) is 30 parts by mass or more and less than 100 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (C). The sealant for an organic electroluminescence display element according to claim 1, wherein the component (B) is contained in an amount of 0.05 to 6 parts by mass and the component (C) is contained in an amount of more than 0 parts by mass and 70 parts by mass or less. The sealant for an organic electroluminescent display element according to claim 2, wherein the amount of hydrophilic functional groups per (meth) acrylate in the component (C) is 3,000 to 15.00 mmol / g. The sealant for an organic electroluminescence display element 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 sealant for an organic electroluminescence display element according to any one of claims 1 to 4, which has a water content of 90 ppm or less. The encapsulant for an organic electroluminescence display element according to any one of claims 1 to 5, wherein the dissolved oxygen amount is 1 ppm or more and 20 ppm or less. The sealant for an organic electroluminescent display element according to any one of claims 1 to 6, which does not contain a bifunctional (meth) acrylate oligomer / polymer and a polyfunctional (meth) acrylate oligomer / polymer. The encapsulant for an organic electroluminescence display element according to any one of claims 1 to 7, wherein the component (A) is an alkanediol di (meth) acrylate having 12 or more and 16 or less carbon atoms. The sealant for an organic electroluminescence display element according to any one of claims 1 to 8, wherein the component (A) is 1,12-dodecanediol di (meth) acrylate. The component (C) is one or more of the group consisting of an alkyl (meth) acrylate having 8 or more carbon atoms, a (meth) acrylate having an alicyclic hydrocarbon group, and a (meth) acrylate having an aromatic hydrocarbon group. The sealant for an organic electroluminescence display element according to any one of claims 2 to 9. The sealant for an organic electroluminescence display element according to any one of claims 2 to 10, wherein the component (C) contains lauryl (meth) acrylate. The component (C) is dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and dicyclopentanyloxy. The encapsulant for an organic electroluminescence display element according to any one of claims 2 to 11, which contains at least one of the group consisting of ethyl (meth) acrylate. The sealant for an organic electroluminescence display element according to any one of claims 2 to 12, wherein the component (C) contains an ethoxylated-o-phenylphenol (meth) acrylate. The encapsulant for an organic electroluminescence display element according to any one of claims 1 to 13, wherein the component (B) is an acylphosphine oxide derivative. A cured product obtained by curing the sealant for an organic electroluminescence display element according to any one of claims 1 to 14. A bonded body bonded with the sealant for an organic electroluminescence display element according to any one of claims 1 to 14. The method for curing an organic electroluminescence display element sealing agent according to any one of claims 1 to 14, which comprises curing using a wavelength of 380 nm or more and 500 nm or less. The method for curing an organic electroluminescence display element sealing agent according to any one of claims 1 to 14, which comprises curing using an LED lamp having an emission wavelength of 395 nm. The method for applying a sealing agent for an organic electroluminescence display element according to any one of claims 1 to 14, which is applied by using an inkjet method. An organic EL device comprising the sealant for an organic electroluminescence display element according to any one of claims 1 to 14. A display comprising the sealant for an organic electroluminescence display element according to any one of claims 1 to 14.