TW201923018A - Sealing agent for organic electroluminescent display elements - Google Patents

Abstract

A sealing agent for organic electroluminescent display elements, which contains (A) an acyclic alkanediol di(meth)acrylate having 6 or more carbon atoms, (B) a cyclic monomer and (C) a photopolymerization initiator, and wherein the cyclic monomer (B) contains a cyclic monofunctional (meth)acrylate and a cyclic bifunctional (meth)acrylate, while satisfying the following formula (I) and formula (III). (I): 8 mPa·s ≤ [eta] ≤ 50 mPa·s (III): [gamma]/2[eta] < 0.9 m/s (In the formulae, [eta] represents the viscosity as measured at 25 DEG C with use of an E-type viscometer; and [gamma] represents the static surface tension as measured by a pendant drop method.).

Description

Sealant for organic electroluminescence display element

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

Organic electroluminescence (EL) elements (also referred to as OLED elements) have attracted attention as element bodies that can emit light with high brightness. However, the OLED element has a problem that the light emitting characteristics are deteriorated due to deterioration due to moisture.

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

An organic electroluminescence display device has been proposed in which a sealing layer is a laminated body in which at least a shielding layer, a resin layer, and a shielding layer are sequentially formed (see Patent Document 2). An organic EL device has been proposed, which includes a sealing layer in which an inorganic material film and an organic material film for sealing an organic EL element are laminated, and is configured to adhere to the uppermost organic material film of the sealing layer and cover the entire upper surface of the uppermost organic material film. Arranged sealed glass substrate (see Patent Document 3).

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

[Prior technical literature]
[Patent Literature]
Patent Document 1 Japanese Patent Application Publication No. 10-74583 Patent Document 2 Japanese Patent Application Publication No. 2001-307873 Patent Document 3 Japanese Patent Application Publication No. 2009-37812 Patent Document 4 Japanese Patent Application Publication No. 2014-225380 Japanese Patent Application Publication No. 5 2012-190612 Patent Document 6 Japanese Patent Application Publication No. 2014-229496 Patent Document 7 Japanese Patent Application Publication No. 2014-196387 Patent Document 8 Japanese Patent Application Publication No. 2014-193970 Patent Document 9 Japanese Patent Application Publication No. 2014-193971 Document 10 International Publication No. WO2014 / 157642 Patent Literature 11 US Publication No. 2017/0062762

[Problems to be Solved by the Invention]
However, from the following viewpoints, there is still room for improvement in the prior art described in the aforementioned literature.

Patent Literature 1 adopts the following method for mass production: sandwiching an organic EL element with a substrate having low moisture permeability, such as glass, and sealing the outer peripheral portion. In this case, the structure becomes a hollow sealing structure, so that it is impossible to prevent moisture from entering the inside of the hollow sealing structure, and there is a problem that the organic EL element is deteriorated.

Patent Documents 2 to 3 are organic films formed by vapor deposition, and therefore, there is a problem that the thickness of the organic film becomes 3 μm or less. When the thickness of the organic film is 3 μm or less, there is a problem that not only the generated particles cannot be completely covered when the element is formed, but also that it is difficult to apply the inorganic film while maintaining flatness.

Patent Document 4 proposes a sealant using an epoxy-based material. However, heating of such a material requires heating, which causes damage to the organic EL element and is also a problem from the viewpoint of productivity. Patent Document 5 proposes a light-curable sealant using an epoxy-based material. However, since such a material is hardened by UV light, the organic EL element is damaged by the UV light, and it is also a problem from the viewpoint of productivity.

Patent Documents 6 to 10 describe that the required characteristic of such a sealing material is to reduce the water vapor transmission rate. However, the sealing material itself penetrates through the pinholes of the passivation film, and there is a problem that the reliability of the organic EL element is reduced. Countermeasures.

Patent Document 11 describes the use of a cyclic monofunctional (meth) acrylate, but does not solve the problem of poor light emission of the organic EL element due to outgassing of its unreacted substance.

As described above, the conventional technology described above cannot combine both the discharge performance when using inkjet and the reliability of the organic EL element, which has been a problem in the past.

[Technical means to solve the problem]
The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a composition that is excellent in, for example, the dischargeability when an inkjet is used when sealing an organic EL element and the reliability of the organic EL element.

The present invention can provide the following.

＜ 1 ＞
An encapsulant for an organic electroluminescence display element comprising (A) an acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) photopolymerization Initiator
(B) the cyclic monomer contains a cyclic monofunctional (meth) acrylate and a cyclic difunctional (meth) acrylate,
And satisfy the following mathematical formulae (I) and (III),
8mPa ･ s ≦ η ≦ 50mPa ･ s… (I)
γ / 2η ＜ 0.9m / s… (III)
(In the formula, η represents a viscosity measured by an E-type viscometer at 25 ° C, and γ represents a static surface tension measured by a hanging drop method).

＜ 2 ＞
An encapsulant for an organic electroluminescence display element comprising (A) an acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) photopolymerization Initiator
Containing 10 to 85 parts by mass of (A) component and 15 to 90 parts by mass of (B) component with respect to 100 parts by mass of (A) component and (B) component in total,
(B) the cyclic monomer contains a cyclic monofunctional (meth) acrylate and a cyclic difunctional (meth) acrylate,
The content ratio of the cyclic monofunctional (meth) acrylate and the cyclic bifunctional (meth) acrylate is 100 parts by mass of the total of the cyclic monofunctional (meth) acrylate and the cyclic bifunctional (meth) acrylate In terms of mass ratio, it is cyclic monofunctional (meth) acrylate: cyclic bifunctional (meth) acrylate = 10 ~ 95: 90 ~ 5, and simultaneously satisfy the following mathematical formulae (I) and (II) ) And (III),
8mPa ･ s ≦ η ≦ 50mPa ･ s… (I)
14mN / m ≦ γ ≦ 40mN / m… (II)
γ / 2η ＜ 0.9m / s… (III)
(In the formula, η represents a viscosity measured by an E-type viscometer at 25 ° C, and γ represents a static surface tension measured by a hanging drop method).

＜ 3 ＞
The sealing agent for organic electroluminescent display elements as described in <1> or <2> whose (B) cyclic monomer contains 1 or more types of alicyclic monomers.

＜ 4 ＞
The sealing agent for organic electroluminescence display elements as described in any one of <1>-<3> which contains a fluorine-containing monomer which has a fluorine atom and a (meth) acryl fluorenyl group as a component (E).

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

＜ 6 ＞
The sealing agent for an organic electroluminescence display device according to <4> or <5>, wherein the fluorine-containing monomer contains a compound represented by the formula (E-1), a compound represented by the formula (E-2), and At least one selected from the group consisting of compounds represented by formula (E-3),
Formula (E-1)
[Chemical Formula 1]

[In the formula (E-1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a fluorinated alkyl group, or a carbon-carbon bond and a part of the carbon-hydrogen bond in the fluorinated alkyl group are inserted with an oxygen atom. Groups, most of the existing R ³ may be the same or different from each other],
Formula (E-2)
[Chemical Formula 2]

[In the formula (E-2), R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents a fluorinated alkyldiyl group, or a part of the carbon-carbon bond and the carbon-hydrogen bond inserted in the fluorinated alkyldiyl group. Oxygen atom groups, most of the R ^{3 present} can be the same or different from each other],
Formula (E-3)
[Chemical Formula 3]

[In the formula (E-3), R ⁵ represents a hydrogen atom or a methyl group, and R ⁶ represents a single bond, an alkanediyl group, a fluorinated alkanediyl group, or a carbon-carbon in the alkanediyl or fluorinated alkanediyl group. A group in which an oxygen atom is partially inserted into a bond or a carbon-hydrogen bond, and Ar ¹ represents a fluorinated aryl group].

＜ 7 ＞
The sealant for an organic electroluminescence display device according to <6>, wherein the fluorine-containing monomer contains a compound represented by the formula (E-1-1), a compound represented by the formula (E-2-1), and At least one selected from the group consisting of compounds represented by formula (E-3-1),
Formula (E-1-1)
[Chemical Formula 4]

[In the formula (E-1-1), R ¹ represents a hydrogen atom or a methyl group, R ²¹ represents a hydrogen atom or a fluorine atom, and n represents an integer of 1 or more. Most of R ²¹ may be the same or different from each other, but at least One R ²¹ is a fluorine atom],
Formula (E-2-1)
[Chemical Formula 5]

[In the formula (E-2-1), R ³ represents a hydrogen atom or a methyl group, R ⁴¹ represents a hydrogen atom or a fluorine atom, and m represents an integer of 1 or more. Most of the R ⁴¹ may be the same or different from each other, but at least One R ⁴¹ is a fluorine atom, and most of the R ^{3 present} may be the same or different from each other],
Formula (E-3-1)
[Chemical Formula 6]

[In formula (E-3-1), R ⁵ represents a hydrogen atom or a methyl group, R ⁶¹ represents a hydrogen atom or a fluorine atom, R ⁶² represents a hydrogen atom or a fluorine atom, p represents an integer of 0 or more, and most of R ⁶¹ exist They may be the same or different from each other, and most of R ⁶² may be the same or different from each other, but at least one R ⁶² is a fluorine atom].

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

＜ 9 ＞
The sealant for an organic electroluminescence display device according to any one of <4> to <8>, wherein the component (E) contains a component containing 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,7,7,8,8,9,9-hexadecane-1,10-decanediol di (meth) acrylate, (meth) acrylic acid-1H, 1H, 5H-octafluoropentyl ester, And (meth) acrylic acid-1H, 1H, 2H, 2H-tridecadecafluorooctyl selected from the group consisting of one or more.

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

＜ 11 ＞
The sealant for an organic electroluminescence display device according to any one of <1> to <10>, which does not contain a bifunctional (meth) acrylate oligomer or a bifunctional (meth) acrylate polymer , A polyfunctional (meth) acrylate oligomer, or a polyfunctional (meth) acrylate polymer.

＜ 12 ＞
The sealing agent for organic electroluminescence display elements as described in any one of <1>-<11> whose glass transition temperature of a hardened body is 65 degreeC or more and 120 degreeC or less.

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

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

<15>
The sealant for an organic electroluminescence display device according to any one of <1> to <14>, wherein the component (B) contains an ethoxylated o-phenylphenol (meth) acrylate, (methyl) 1) in the group consisting of m-phenoxybenzyl acrylate, tricyclodecane dimethanol di (meth) acrylate, and ethoxylated bisphenol A di (meth) acrylate represented by the following structural formula More than
[Chemical Formula 7]

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

<16>
The sealing compound for organic electroluminescence display elements as described in any one of <1>-<15> whose (A) component is an alkanediol di (meth) acrylate with 12 or less carbon numbers.

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

<18>
The sealing compound for organic electroluminescence display elements according to any one of <1> to <17>, wherein the component (C) contains 2,4,6-trimethylbenzyl-diphenyl-phosphine Oxide.

＜ 19 ＞
The sealing agent for organic electroluminescent display elements as described in any one of <1>-<18> whose content of (C) component is 0.5-4 mass parts.

＜ 20 ＞
The sealing agent for organic electroluminescence display elements as described in any one of <1>-<19> which further contains (D) antioxidant.

＜ 21 ＞
The sealing agent for organic electroluminescent display elements as described in <20> whose (D) component is a hindered phenol antioxidant.

＜ 22 ＞
The sealing agent for organic electroluminescence display elements as described in <20> or <21> which contains two or more (D) components.

＜ 23 ＞
The sealing compound for organic electroluminescence display elements according to any one of <1> to <22>, which is cured at a wavelength of 395 nm to 500 nm.

＜ 24 ＞
The sealant for an organic electroluminescence display device according to <23>, wherein the sealant for an organic electroluminescence display element is cured with an 395 nm LED lamp.

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

＜ 26 ＞
An organic EL device containing the hardened body according to <25>.

＜ 27 ＞
A display containing the hardened body according to <25>.

＜ 28 ＞
A flexible display containing the hardened body according to <25>.

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

[Inventive effect]
The sealant according to the present invention can exhibit the following effects: excellent dischargeability when inkjet is used, and excellent reliability of the obtained organic EL element.

This embodiment will be described below. The range of numbers in this specification includes the upper limit and lower limit unless otherwise specified. In this specification, unless otherwise specified, it is defined as follows. (Meth) acrylate means an acrylate or a methacrylate, and the same applies to "(meth) acryloxy" or "(meth) acrylamide". The "monofunctional (meth) acrylate" refers to a (meth) acrylate having one (meth) acrylfluorenyl group, and the "bifunctional (meth) acrylate" refers to having two (meth) acrylic acid Amidino (meth) acrylate. "Polyfunctional (meth) acrylate" means a (meth) acrylate having three or more (meth) acrylfluorenyl groups, and does not include a bifunctional (meth) acrylate.

The top-emitting organic EL device is described below as an example, and it emits light from an organic EL element formed on a substrate on the opposite side to the substrate. The top emission type organic EL device has a structure in which an organic EL element, a sealing layer, and a sealing substrate are sequentially formed, wherein the organic EL element sequentially stacks an anode, an organic EL layer including a light-emitting layer, and a cathode on the substrate; the The sealing layer is composed of a laminated film of an inorganic film and an organic film covering the entire organic EL element; and the sealing substrate is provided on the sealing layer.

As the substrate, various substrates 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 are preferred, and a glass substrate is more preferred.

Examples of the plastic used for the plastic substrate include polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, polyoxadiazole, aromatic polyamide, and polybenzo. Imidazole, polybenzothiazole, polybenzoxazole, polythiazole, poly-p-styrene, polymethyl methacrylate, polystyrene, polycarbonate, polycycloolefin, and polyacrylic acid. From the viewpoints of low moisture permeability, low oxygen permeability, and heat resistance, among these, polyimide, polyetherimide, polyethylene terephthalate, and polynaphthalene are preferred. One or more of the group consisting of ethylene formate, polyoxadiazole, aromatic polyamide, polybenzimidazole, polybenzothiazole, polybenzoxazole, polythiazole, and poly-p-styrene From the viewpoint of higher transmittance of energy rays such as ultraviolet rays and visible rays, it is more preferable to use polyimide, polyetherimide, polyethylene terephthalate, and polyethylene naphthalate. One or more members of the group consisting of esters.

The anode generally uses a conductive metal oxide film or a translucent metal film having a large work function (preferably having a work function greater than 4.0 eV). Examples of the anode material include metal oxides such as indium tin oxide (hereinafter referred to as ITO), tin oxide, metals such as gold (Au), platinum (Pt), silver (Ag), and copper (Cu), or the like. Organic transparent conductive films such as an alloy of at least one of these, polyaniline or a derivative thereof, and polythiophene or a derivative thereof. The anode may be formed of two or more layers as necessary. The thickness of the anode film can be appropriately selected in consideration of the conductivity (the light transmittance is also considered in the case of the bottom emission type). The thickness of the anode film 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 anode production method include a vacuum evaporation method, a sputtering method, an ion plating method, and a plating method. In the top emission type, a reflective film may be provided under the anode, and the reflective film reflects light emitted from the substrate side.

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 light-emitting material include fluorescent or phosphorescent organic substances (low-molecular compounds or high-molecular compounds). The light emitting layer may further contain a dopant material. Examples of the organic substance include a pigment-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 or changing the emission wavelength. The thickness of the light-emitting layer composed of these organic substances and dopants that are optionally doped is usually 2 to 200 nm.

(Pigment-based material)
Examples of the pigment-based material include methylcyclopentylamine derivative, tetraphenylbutadiene derivative compound, triphenylamine derivative, oxadiazole derivative, pyrazoloquinoline derivative, and distyrylbenzene derivative. Compounds, distyryl arylidene derivatives, pyrrole derivatives, thiophene ring compounds, pyridine ring compounds, perinone derivatives, fluorene derivatives, oligothiophene derivatives, trifumarylamine derivatives, Oxadiazole dimer, pyrazoline dimer, etc.

(Metal complex material)
Examples of the metal complex-based material include metal complexes having light emission derived from a triplet excited state such as iridium complex, platinum complex, aluminum hydroxyquinoline complex, and benzohydroxyquinoline beryllium complex. , Metal complexes such as benzoxazolyl zinc complexes, benzothiazole zinc complexes, azomethyl zinc complexes, zinc porphyrin complexes, fluorene complexes, and the like. Examples of metal complexes include rare earth metals such as thorium (Tb), thorium (Eu), and thorium (Dy) as the central metal, aluminum (Al), zinc (Zn), beryllium (Be), and the like. Metal complexes such as diazoles, thiadiazoles, phenylpyridines, phenylbenzimidazoles, and quinoline structures. Among these, metal complexes in which the center metal has aluminum (Al) and the ligand has a quinoline structure are preferred. Among metal complexes in which the central metal has aluminum (Al) and the ligand has a quinoline structure, tris (8-hydroxyquinoline) aluminum is preferred.

(Polymer Materials)
Examples of the polymer material include a polyparastyrene derivative, a polythiophene derivative, a polyparaphenylene derivative, a polysilane derivative, a polyacetylene derivative, a polyfluorene derivative, a polyvinylcarbazole derivative, and A substance in which a pigment body or a metal complex-based light-emitting material is polymerized.

Examples of the light-emitting material that emits blue light include distyryl arylidene derivatives, oxadiazole derivatives, polyvinylcarbazole derivatives, polyparaphenylene derivatives, polyfluorene derivatives, And such polymers. Among these, polymer materials are preferred. Among the polymer materials, one or more members selected from the group consisting of a polyvinylcarbazole derivative, a polyparaphenylene derivative, and a polyfluorene derivative are preferable.

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

Examples of the material that emits red light include coumarin derivatives, thiophene ring compounds, polyparastyrene derivatives, polythiophene derivatives, polyfluorene derivatives, and polymers thereof. Among these, polymer materials are preferred. Among the polymer materials, one or more members selected from the group consisting of a polyparastyrene derivative, a polythiophene derivative, and a polyfluorene derivative are preferable.

(Dopant material)
Examples of the dopant material include a europium derivative, a coumarin derivative, a rubrene derivative, a quinacridone derivative, a squarylium derivative, a porphyrin derivative, a styryl-based pigment, and a thickener. Tetrabenzene derivatives, pyrazolidine derivatives, decacyclene, and phenoxazone.

In addition to the light emitting layer, the organic EL layer may be a layer provided between the light emitting layer and the anode and a layer provided between the light emitting layer and the cathode. First, the layer provided between the light-emitting layer and the anode may be a hole-injection layer that improves hole-injection efficiency from the anode, or a hole-transport layer that transports holes injected from the anode or hole-injection layer to the light-emitting layer. Wait. Examples of the layer provided between the light emitting layer and the cathode include an electron injection layer that improves the efficiency of electron injection from the cathode, and an electron transport layer that transports electrons injected from the cathode or the electron injection layer to the light emitting layer.

(Hole injection layer)
Examples of the material for forming the hole injection layer include phenylamines such as 4 ′, 4 ”-tri {2-naphthyl (phenyl) amino} triphenylamine, starburst amines, and phthalocyanin. , Oxides such as vanadium oxide, molybdenum oxide, ruthenium oxide, aluminum oxide, amorphous carbon, polyaniline, and polythiophene derivatives.

(Hole transport layer)
Examples of the material constituting the hole transporting layer include polyvinyl carbazole or a derivative thereof, polysilane or a derivative thereof, a polysiloxane derivative having an aromatic amine in a side chain or a main chain, a pyrazoline derivative, Arylamine derivative, fluorene derivative, triphenyldiamine derivative, benzidine derivative, polyaniline or derivative thereof, polythiophene or derivative thereof, polyarylamine or derivative thereof, polypyrrole or Derivatives, poly (p-phenylene vinylene) or its derivatives, and poly (2,5-thienyl vinylene) or its derivatives.

When the hole injection layer or hole transport layer has a function of preventing electron transport, the hole transport layer or hole injection layer is called an electron blocking layer.

(Electronic transport layer)
Examples of the material constituting the electron transport layer include oxadiazole derivatives, anthraquinone dimethane or its derivatives, benzoquinone or its derivatives, naphthoquinone or its derivatives, anthraquinone or its derivatives, and tetracyanoanthraquinone. Dimethane or its derivative, fluorenone derivative, diphenyl dicyanoethylene or its derivative, p-benzoquinone derivative, 8-hydroxyquinoline or its derivative, polyquinoline or its derivative, poly Quinoxaline or a derivative thereof, and polyfluorene or a derivative thereof. Examples of the derivative include a metal complex. Among these, 8-hydroxyquinoline or a derivative thereof is preferable. From the viewpoint that a fluorescent or phosphorescent organic substance contained in the light-emitting layer can be used, tris (8-hydroxyquinoline) aluminum is preferred among 8-hydroxyquinoline or a derivative thereof.

(Electron injection layer)
The electron injection layer is an electron injection layer composed of a single-layer structure of a calcium (Ca) layer depending on the type of the light emitting layer, or a metal having a work function of 1.5 to 3.0 eV and a metal of Groups IA and IIA of the periodic table, The monolayer structure of a layer formed by one or more of the group consisting of metal oxides, halides, and carbonates, or a metal having a work function of 1.5 to 3.0 eV from metals of Groups IA and IIA of the periodic table, and An electron injection layer and the like formed of a layered structure of a layer formed of one or more metals and oxides, halides, and carbonates of the metal and a Ca layer. Examples of the metal of Group IA of the periodic table having a work function of 1.5 to 3.0 eV, or oxides, halides, and carbonates thereof include lithium (Li), lithium fluoride, sodium oxide, lithium oxide, and lithium carbonate. Examples of metals of Group IIA of the periodic table or work oxides, halides, and carbonates having a work function of 1.5 to 3.0 eV include strontium (Sr), magnesium oxide, magnesium fluoride, strontium fluoride, barium fluoride, strontium oxide, And magnesium carbonate.

When the electron transport layer or the electron injection layer has a function of preventing hole transport, the electron transport layer or the electron injection layer is referred to as a hole blocking layer.

The cathode is preferably a transparent or translucent material with a small work function (preferably having a work function less than 4.0 eV) and electrons are easily injected into the light emitting layer. 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), yttrium (Y), indium (In), cerium (Ce), scandium (Sm), europium (Eu) , Ytterbium (Tb), ytterbium (Yb) and other metals, or an alloy composed of two or more of the above metals, or one or more of these with gold (Au), silver (Ag), platinum (Pt), An alloy composed 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 multilayer structure of two or more layers include the above-mentioned metal, metal oxide, fluoride, and a multilayer structure of these alloys with metals such as Al, Ag, and Cr. The thickness of the cathode film can be appropriately selected in consideration of conductivity and durability. The thickness of the cathode film 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 lamination method in which a metal thin film is subjected to thermocompression bonding.

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 using the organic EL element in this embodiment may have any of the following layer configurations (i) to (xv).
(i) Anode / hole transport layer / light emitting layer / cathode
(ii) Anode / light-emitting layer / electron transport layer / cathode
(iii) Anode / hole transport layer / light-emitting layer / electron transport layer / cathode
(iv) Anode / hole injection layer / light emitting layer / cathode
(v) Anode / light-emitting layer / electron injection layer / cathode
(vi) Anode / hole injection layer / light emitting layer / electron injection layer / cathode
(vii) Anode / hole injection layer / hole transport layer / light emitting layer / cathode
(viii) Anode / hole transport layer / light emitting layer / electron injection layer / cathode
(ix) Anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode
(x) Anode / hole injection layer / light emitting layer / electron transport layer / cathode
(xi) Anode / Light-emitting layer / Electron transport layer / Electron injection layer / Cathode
(xii) Anode / hole injection layer / light emitting layer / electron transport layer / electron injection layer / cathode
(xiii) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / cathode
(xiv) Anode / hole transport layer / light-emitting layer / electron transport layer / electron injection layer / cathode
(xv) Anode / hole injection layer / hole transport layer / light emitting layer / electron transport layer / electron injection layer / cathode
(Here, "/" means that the layers are adjacent and stacked. The same applies below.)

In order to prevent a gas such as water vapor or oxygen from coming into contact with the organic EL element, the organic EL element is sealed with a layer having high shielding properties against the gas, and a sealing layer is provided for this purpose. The sealing layer alternately forms an inorganic film and an organic film from the bottom. The inorganic / organic laminate can be repeatedly formed more than twice.

In a display device of an active matrix method in which a thin film transistor (TFT) provided for each pixel controls current to each organic EL element, a 0.5 μm formed by partitioning a TFT or a partition wall of blue, green, and red pixels is formed. ~ 3 μm unevenness exists between the cathode or anode and the sealing layer. In an active matrix display device, it is necessary to flatten the unevenness by a sealing layer, reduce the interference effect on light emission, and further improve the sealing performance. When this sealing layer is formed by the sealant concerning this embodiment, the effect of obtaining favorable flatness can be exhibited.

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 where the organic EL device is placed. The inorganic film of the inorganic / organic laminate is preferably a continuous 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, or such a laminated film.

In order to cover defects such as pinholes formed on the inorganic film, and to provide flatness to the surface, an organic film of an inorganic / organic laminate is provided. The organic film is formed in a narrower area than the area formed by the inorganic film. The reason is that if the organic substance film is formed in the same or wider manner as the inorganic substance film formation region, the region where the organic substance film is exposed is deteriorated. However, the uppermost organic film formed in the uppermost layer of the entire sealing layer is formed in a region almost the same as the inorganic film formation region. Next, it is formed so that the upper surface of the sealing layer may be flattened. As the organic film, a composition having a good adhesion function to the inorganic film is used.

The purpose of this embodiment is to provide a sealant for an organic electroluminescence display element forming the organic film, which is suitable for, for example, inkjet coating capable of short-term coating with a film thickness of 3 μm or more and excellent flatness, ejection properties of inkjet, and Excellent flatness after inkjet coating, not only has barrier properties against water vapor (hereinafter also referred to as low moisture permeability), but also the sealant itself does not penetrate through the pinholes on the inorganic film, reducing the reliability of the organic EL element. . When an inkjet method is used, an organic film can be formed uniformly at high speed.

If the sealant itself penetrates through the pinholes on the inorganic film, not only will the OLED elements around the pinholes not emit light, but when used for a long time, the sealant will penetrate the organic light-emitting material layer, which will increase the poor light emission, that is, produce dark spots. . That is, the reliability of OLED elements will be significantly reduced.

In addition, according to Lucas-Washburn (Equation 1) of the liquid penetration basic formula, it is known that the penetration depth l of the pinhole depends on the time (t), pore diameter (r), viscosity (η), Liquid surface tension (γ) and contact angle (θ) with a solid surface.
[Mathematical formula 1]

(Formula 1)

In Equation 1, the contact angle θ and the pore diameter r with the solid surface are parameters that depend on the inorganic film. Therefore, it is found that the sealant can improve the reliability of the organic EL device by controlling the penetration rate according to Equation 2.
γ / 2η ＜ 0.9m / s… Equation 2
As described later, there is a problem that a dark spot is generated due to penetration of a sealant in an organic EL element and light emission failure is caused. By satisfying the condition of the above formula 2, penetration of the sealant as described above can be suppressed.

Regarding the viscosity of the composition of the present embodiment, the viscosity measured using an E-type viscometer at 25 ° C and 100 rpm is preferably 8 mPa 较佳 s or more and 50 mPa ･ s or less. When it is difficult to spit out by inkjet, it is suitable to heat the inkjet head. If the viscosity is less than 8 mPa ･ s, the applied organic EL display element sealant will not only flow out of the organic EL display element before curing, but also flow into pin holes on the inorganic film, thereby reducing the reliability of the OLED element. If the viscosity exceeds 50 mPa ･ s, it is difficult to apply the inkjet ink. The viscosity of the composition is more preferably 8 mPa ･ s to 25 mPa ･ s.

The static surface tension of the composition of this embodiment is preferably 14 mN / m or more and 40 mN / m or less. The static surface tension is measured by the plate method, the ring method, the hanging drop method, and the like, but the static surface tension defined in this embodiment is measured by the hanging drop method. The hanging drop method refers to a method in which a liquid is extruded from the front end of a tube, and the surface tension is calculated from the shape of a pendant drop. If the static surface tension is less than 14 mN / m, the applied organic EL display element sealant will not only flow out of the organic EL display element before curing, but also flow into pin holes in the inorganic film, thereby reducing the reliability of the OLED element. . If the static surface tension exceeds 40 mN / m, it will be difficult to apply by inkjet. The static surface tension of the composition is more preferably 20 mN / m to 30 mN / m.

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

(A) Acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms means a bifunctional (meth) acrylate having 6 or more carbon atoms in the main chain. The acyclic (A) component does not have a cyclic molecular structure. In view of the better effects of low moisture permeability and inkjet discharge properties and flatness after inkjet coating, the (A) component is preferably α, ω-linear alkanediol di (meth) acrylic acid ester. The carbon number of the alkane which is more preferably a main chain may be 12 or less. Of the α, ω-linear alkanediol di (meth) acrylates, 1,6-hexanediol di (meth) acrylate and 1,9-nonanediol di (meth) acrylate are preferred. , 1,10-decanediol di (meth) acrylate, and 1,12-dodecanediol di (meth) acrylate, one or more of them, more preferably 1,9 In the group consisting of nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, and 1,12-dodecanediol di (meth) acrylate One or more kinds are preferred, and 1,12-dodecanediol di (meth) acrylate is most preferable. The alkane of the main chain of the component (A) may be linear or branched. It is preferred that the component (A) does not have a fluorine atom and is different from the component (E) described later.

The content of the component (A) is preferably 10 to 85 parts by mass based on 100 parts by mass of the total of the components (A) and (B). When the content of (A) is 10 parts by mass or more, low moisture permeability can be obtained, the viscosity becomes 85 or less by mass, and the reliability of the organic EL element is improved. From the viewpoint of low moisture permeability and reliability of the organic EL element, the content of (A) is preferably 30 to 70 parts by mass, more preferably 35 to 68 parts by mass, and most preferably 45 to 65 parts by mass.

(B) A cyclic monomer is a group having a cyclic structure in the molecule and having at least one group consisting of a (meth) acrylic acid ester group, a (meth) acrylamide group, and an N-vinyl group. Monomer of the unsaturated double bond group selected in. That is, the component (B) having a cyclic structure is different from the acyclic component (A). Examples of such a cyclic structure include a monomer having a heterocyclic structure such as a cyclic amido group, a tetrahydrofurfuryl group, a piperidinyl group, an aromatic hydrocarbon-based cyclic structure, and an aliphatic hydrocarbon-based cyclic structure. Wait. Among these, from the viewpoint of inkjet ejection properties and low moisture permeability, it is preferable to be a group consisting of monomers having an aromatic hydrocarbon-based cyclic structure and an aliphatic hydrocarbon-based cyclic structure. 1 or more. More preferably, a cyclic (meth) acrylate monomer having an aromatic hydrocarbon-based cyclic structure and an aliphatic hydrocarbon-based cyclic structure can be used as the (B) component. It is preferred that the component (B) does not have a fluorine atom and is different from the component (E) described later.

Examples of the (meth) acrylate having an aromatic hydrocarbon-based cyclic structure include benzyl (meth) acrylate, 4-butylphenyl (meth) acrylate, phenyl (meth) acrylate, and (meth) acrylate. (Meth) acrylate-2,4,5-tetramethylphenyl ester, 4-chlorophenyl (meth) acrylate, phenoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate (2-HPA), 2- (meth) propenyloxyhexahydrophthalic acid, 2- (meth) propenyloxy Ethyl-2-hydroxypropylphthalic acid, EO modified phenol (meth) acrylate, EO modified cresol (meth) acrylate, EO modified nonylphenol (meth) acrylate, PO Modified nonylphenol (meth) acrylate, ethoxylated o-phenylphenol (meth) acrylate, and m-phenoxybenzyl (meth) acrylate with one or more aromatic hydrocarbons in the molecule Cyclic structure of monofunctional (meth) acrylate, or ethoxylated bisphenol A di (meth) acrylate, propoxylated bisphenol A di (meth) acrylate, propoxylated ethyl Oxidized bisphenol A di (meth) acrylate, and bisphenol A epoxy di (meth) acrylate Bifunctional (meth) acrylate. These can be used in combination of one or more of them. In particular, in the sealant for an organic electroluminescence display element according to this embodiment, from the viewpoint of low moisture permeability and reliability of the organic EL element, it is preferable to have two or more ring structures in the molecule. The (meth) acrylate having two or more aromatic hydrocarbon-based cyclic structures in the molecule is preferably ethoxylated o-phenylphenol (meth) acrylate, m-phenoxybenzyl (meth) acrylate Esters, and one or more of the group consisting of ethoxylated bisphenol A di (meth) acrylate, more preferably ethoxylated o-phenylphenol (meth) acrylate and ethoxylated One or more of the group consisting of bisphenol A di (meth) acrylate.

Examples of the alicyclic hydrocarbon group in the monomer having an aliphatic hydrocarbon-based cyclic structure include a group having a dicyclopentadiene skeleton such as dicyclopentyl or dicyclopentenyl, cyclohexyl, isofluorenyl, Cyclodecadienyl, norbornyl, and adamantyl. Among these, a group having a dicyclopentadiene skeleton is preferred. Examples of the (meth) acrylate having an alicyclic hydrocarbon group include cyclohexyl (meth) acrylate, dicyclopentyl (meth) acrylate, dicyclopentyloxyethyl (meth) acrylate, and (methyl) ) Dicyclopentenyl acrylate, dicyclopentenyl oxyethyl (meth) acrylate, isoamyl (meth) acrylate, and methoxylated cyclodecadiene (meth) acrylate and the like. The (meth) acrylate having a dicyclopentadiene skeleton is preferably tricyclodecanedimethanol di (meth) acrylate, dicyclopentyloxyethyl (meth) acrylate, or (meth) acrylic acid. One or more of the group consisting of dicyclopentenyl ester and dicyclopentenyl oxyethyl (meth) acrylate are more preferably composed of (meth) acrylic bicyclo from the viewpoint of low moisture permeability. One or more of the group consisting of amyl ester and tricyclodecane dimethanol di (meth) acrylate.

The inventors have found that (B) the cyclic monomer needs to contain a mixture of a cyclic monofunctional (meth) acrylate and a cyclic difunctional (meth) acrylate in a specific ratio. The reason is as follows. From the viewpoint of low moisture permeability, the effect of the cyclic monofunctional (meth) acrylate is good, but the boiling point is low. Therefore, unreacted substances may be outgassed, which may cause poor light emission of the organic EL element. The cyclic bifunctional (meth) acrylate is excellent in low moisture permeability and low volatility, so it is effective from the viewpoint of the reliability of an OLED element, but has a high viscosity, which adversely affects the inkjet ejectability. problem. The present inventors have found that by using a cyclic monofunctional (meth) acrylate and a cyclic bifunctional (meth) acrylate in a specific ratio, it is possible to obtain a combination of low moisture permeability and an OLED that cannot be achieved in the prior art. Reliable effects, and further completed the present invention. That is, in a total of 100 parts by mass of methacrylate and acrylate, the content ratio of the monofunctional (meth) acrylate to the bifunctional (meth) acrylate is in terms of mass ratio, and the monofunctional (meth) ) Acrylate: Bifunctional (meth) acrylate = 10 ~ 95: 90 ~ 5, more preferably 40 ~ 90: 60 ~ 10, most preferably 65 ~ 85: 35 ~ 15.

The cyclic monofunctional (meth) acrylate is preferably any one of the following compounds. Cyclic monofunctional (meth) acrylate represented by the following structural formula
[Chemical Formula 8]

(R ₁ in the above formula is independently a hydrogen atom or a methyl group, and the average 値 of n is preferably 1 to 10, particularly preferably n = 1), and a cyclic monofunctional (methyl group) represented by the following structural formula )Acrylate
[Chemical Formula 9]

(Y in the above formula is -CH ₂ -,-(CH (R ⁵ ) CH ₂ O) _m1 -,-(CH (R ⁵ ) CH ₂ S) _{m 2-} (wherein R ⁵ is a hydrogen atom or a methyl group, m1 and m2 are numbers from 1 to 4), R ³ is a hydrogen atom or a methyl group, and R ⁴ is any substituent represented by the following structural formula).
[Chemical Formula 10]

The cyclic bifunctional (meth) acrylate is preferably an ethoxylated bisphenol A di (meth) acrylate compound represented by the following structural formula. R in the following formula is each independently a hydrogen atom or a methyl group. Regarding m and n in the formula, m + n = 2 to 10 is preferable.
[Chemical Formula 11]

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

The content of the component (B) is preferably 15 to 90 parts by mass based on 100 parts by mass of the total of the components (A) and (B). When the content of (B) is 15 parts by mass or more, the viscosity is increased and the reliability of the organic EL element is improved. When the content is (90) parts by mass or less, it is excellent from the viewpoint of inkjet coating properties. From the viewpoint of low moisture permeability and reliability of the organic EL element, the content of (B) is preferably 30 to 70 parts by mass, more preferably 32 to 65 parts by mass, and most preferably 45 to 65 parts by mass.

(C) A photopolymerization initiator is used for sensitization by visible light or an ultraviolet-ray active light, and to promote photohardening of a resin composition. The photopolymerization initiator is preferably a photoradical polymerization initiator. Examples of the photoradical polymerization initiator include diphenylketone and its derivatives, diphenylethylenedione and its derivatives, anthraquinone and its derivatives, benzoin, benzoin methyl ether, benzoin ethyl ether, and benzoin Benzoin derivatives such as propyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, acetophenone derivatives such as diethoxyacetophenone, 4-tert-butyltrichloroacetophenone, 2- Dimethylaminoethylbenzoate, p-dimethylaminoethylbenzoate, diphenyldisulfide, thioxanthone and its derivatives, camphorquinone, 7,7-dimethyl -2,3-dioxybicyclo [2.2.1] heptane-1-carboxylic acid, 7,7-dimethyl-2,3-dioxybicyclo [2.2.1] heptane-1-carboxy- 2-bromoethyl ester, 7,7-dimethyl-2,3-dioxybicyclo [2.2.1] heptane-1-carboxy-2-methyl ester, 7,7-dimethyl-2, Camphorquinone derivatives such as 3-dioxybicyclo [2.2.1] heptane-1-carboxylic acid chloride, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinyl Α-Aminobenzonone derivatives such as propane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinylphenyl) -butanone-1, benzamyl Diphenylphosphine oxide, 2,4,6-trimethylbenzylidene-diphenyl-phosphine Compounds, benzamyl diethoxyphosphine oxide, 2,4,6-trimethylbenzyl dimethoxyphenylphosphine oxide, 2,4,6-trimethylbenzyl Phenylphosphine oxide derivatives such as diethoxyphenylphosphine oxide, bis (2,4,6-trimethylbenzyl) -phenylphosphine oxide, phenyl-glyoxylic acid-methyl Esters, oxy-phenyl-acetic acid 2- [2-oxy-2-phenyl-acetamido-ethoxy] -ethyl ester and oxy-phenyl-acetic acid 2- [2-hydroxy-ethoxy ] -Ethyl ester and the like. The photopolymerization initiator can be used in combination of one or more kinds. Among these, a fluorenylphosphine oxide derivative is preferred in that it can be cured using only visible light of 390 nm or more during curing, and can be cured without causing damage to the organic electroluminescence display element. Among the fluorenylphosphine oxide derivatives, 2,4,6-trimethylbenzyl is preferred because it does not reduce visible light transmittance when used as a display and can be cured using only light of 395 nm or more. Fluorenyl-diphenyl-phosphine oxide. Examples of the 2,4,6-trimethylbenzylidene-diphenyl-phosphine oxide include "Irgacure TPO" manufactured by BASF Japan.

The content of (C) the photopolymerization initiator is preferably from 0.05 to 6 parts by mass, more preferably from 0.5 to 4 parts by mass, and most preferably from 2 to 100 parts by mass with respect to (A) component and (B) component in total. 3.9 parts by mass, and even more preferably 2.5 to 3.5 parts by mass. (C) When the content of the component is 0.05 parts by mass or more, the effect of promoting hardening can be surely obtained, and when it is 6 parts by mass or less, the visible light transmittance is not reduced when used in a display.

In the composition of the present embodiment, the (meth) acrylate is preferably a monomer from the viewpoint of inkjet ejectability. The component (A) or the component (B) is preferably a monomer. The monomer molecular weight is preferably 1,000 or less. From the viewpoint of inkjet ejectability, the bifunctional (meth) acrylate oligomer / polymer and polyfunctional are contained in 100 parts by mass of the (meth) acrylate containing the (A) component or the (B) component. The (meth) acrylate oligomer / polymer preferably contains 3 parts by mass or less, more preferably contains 1 part by mass or less, and most preferably does not contain it.

In the composition of the present embodiment, from the viewpoint of reducing the free energy of the surface after coating and obtaining high flatness, it is preferred that the component (E) contains fluorine containing a fluorine atom and a (meth) acrylfluorenyl group. monomer. (Meth) acrylfluorenyl means acrylfluorenyl or methacrylfluorenyl. The fluorine-containing monomer may be used singly or in combination of two or more kinds.

The content of the component (E) is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 4 parts by mass, and still more preferably 0.9 to 1.6 parts by mass with respect to 100 parts by mass of the components (A) and (B) in total. . When it is 0.1 parts by mass or more, flatness is ensured, and when it is 10 parts by mass or less, good inkjet coating properties are ensured.

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

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

The number of (meth) acrylfluorenyl groups in the fluorine-containing monomer may be 1 or more. From the viewpoint of easily obtaining a hardened body having a low glass transition temperature, the number of (meth) acrylfluorenyl groups in the fluorine-containing monomer may be one. In addition, from the viewpoint of easily obtaining a hardened body having a high glass transition temperature, the number of (meth) acrylfluorenyl groups in the fluorine-containing monomer may be 2 or more. The upper limit of the number of (meth) acrylfluorene groups in the fluorinated monomer is not particularly limited, and may be, for example, 4 or less. From the viewpoint of easily obtaining a hardened body having excellent flexibility, 3 or less is preferable, and 2 or less is more preferable. .

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

Formula (E-1)
[Chemical Formula 12]

In the formula (E-1), R ¹ represents a hydrogen atom or a methyl group. In addition, R ² represents a fluorinated alkyl group or a group in which an oxygen atom is partially inserted into a carbon-carbon bond and a carbon-hydrogen bond in the fluorinated alkyl group.

A fluorinated alkyl group can be regarded as a group in which a part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. The number of carbon atoms of the fluorinated alkyl group is not particularly limited, and may be, for example, one or more, and preferably two or more. The number of carbon atoms in the fluorinated alkyl group may be, for example, 25 or less, or 20 or less.

As the fluorinated alkyl group, a group containing a difluoromethylene group (-CF _2- ) can be suitably used.

Specific examples of the fluorinated alkyl group include difluoromethyl, trifluoromethyl, 1,1-difluoroethyl, 2,2-difluoroethyl, 1,1,1-trifluoroethyl, 2 , 2,2-trifluoroethyl, perfluoroethyl, 1,1,2,2-tetrafluoropropyl, 1,1,1,2,2-pentafluoropropyl, 1,1,2,2 , 3,3-hexafluoropropyl, perfluoropropyl, perfluoroethylmethyl, 1- (trifluoromethyl) -1,2,2,2-tetrafluoroethyl, 2,2,3, 3-tetrafluoropropyl, perfluoropropyl, 1,1,2,2-tetrafluorobutyl, 1,1,2,2,3,3-hexafluorobutyl, 1,1,1,2, 2,3,3-heptafluorobutyl, 1,1,2,2,3,3,4,4-octafluorobutyl, perfluorobutyl, 1,1-bis (trifluoro) methyl-2 , 2,2-trifluoroethyl, 2- (perfluoropropyl) ethyl, 1,1,2,2,3,3,4,4-octafluoropentyl, 2,2,3,3, 4,4,5,5-octafluoropentyl, perfluoropentyl, 1,1,2,2,3,4,4,5,5-decafluoropentyl, 1,1-bis (tri (Fluoromethyl) -2,2,3,3,3-pentafluoropropyl, 2- (perfluorobutyl) ethyl, 1,1,1,2,2,3,3,4,4-nine Fluoropentyl, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl, 1,1,2,2,3,3,4,4,5,5,6, 6-dodecylfluorohexyl, perfluorohexyl, perfluoropentylmethyl and perfluorohexyl.

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

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

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

[Chemical Formula 13]

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

Examples of specific examples of the compound represented by the formula (E-1) include compounds represented by the following formula (E-1-1).

Formula (E-1-1)
[Chemical Formula 14]

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

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

R ²¹ is mostly present in formula (E-1-1), but at least one of them is a fluorine atom. In addition, R ²¹ preferably has two or more fluorine atoms, and more preferably three or more fluorine atoms. R ²¹ may all be a fluorine atom.

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

The compound represented by formula (E-1-1) is preferably a divalent methylene group (-C (R ²¹ ) _2- ) in which at least one of the parentheses with n is difluoromethylene (-CF _2- ).

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

Formula (E-2)
[Chemical Formula 15]

In the formula (E-2), R ³ represents a hydrogen atom or a methyl group. R ⁴ represents a fluorinated alkyldiyl group, or a group in which an oxygen atom is partially inserted into a carbon-carbon bond and a carbon-hydrogen bond in the fluorinated alkyldiyl group. Most of the R ^{3 present} may be the same or different from each other.

The fluorinated alkanediyl group can be regarded as a group in which a part or all of the hydrogen atoms of the alkanediyl group are substituted with fluorine atoms. The number of carbon atoms of the fluorinated alkyldiyl group is not particularly limited, and may be, for example, one or more, preferably two or more, more preferably three or more, and still more preferably four or more. The number of carbon atoms in the fluorinated alkyldiyl group may be, for example, 17 or less, preferably 12 or less, and more preferably 10 or less.

As the fluorinated alkyldiyl group, a difluoromethylene (-CF ₂ -)-containing group is suitably used.

Specific examples of the fluorinated alkyldiyl group include linear or branched fluorinated alkyldiyl groups having 1 to 17 carbon atoms (e.g., 2, 2, 3, 3, 4, 4, 5, 5, 6, 6 , 7,7,8,8,9,9-hexadecylfluoro-1,10-decanediyl), and fluorinated cycloalkanediyl having 1 to 17 carbon atoms.

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

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

Specific examples of the oxygen-containing group of R ⁴ include a group represented by the following formula.
[Chemical Formula 16]

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

An example of a specific example of the compound represented by formula (E-2) is a compound represented by the following formula (E-2-1).

Formula (E-2-1)
[Chemical Formula 17]

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

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

R ⁴¹ is mostly present in formula (E-2-1), but at least one of them is a fluorine atom. In addition, two or more of R ⁴¹ are preferably fluorine atoms, and more preferably four or more are fluorine atoms. R ⁴¹ may all be a fluorine atom.

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

In the compound represented by formula (E-2-1), it is preferred that at least one of the divalent group (-C (R ⁴¹ ) _2- ) in parentheses with m is difluoromethylene (-CF _2- ).

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

Formula (E-3)
[Chemical Formula 18]

In the formula (E-3), R ⁵ represents a hydrogen atom or a methyl group. R ⁶ represents a single bond, an alkanediyl group, a fluorinated alkanediyl group, or a group in which an oxygen atom is partially inserted into a carbon-carbon bond and a carbon-hydrogen bond in the alkanediyl group or the fluorinated alkanediyl group. . Ar ¹ represents a fluorinated aryl group.

In addition, "R ⁶ represents a single bond" means that Ar ¹ is directly bonded to an oxygen atom.

The fluorinated aryl group of Ar ¹ is preferably a fluorinated phenyl group. It can be regarded as a fluorinated phenyl group, and a group in which 1 to 5 hydrogen atoms in the phenyl group are substituted with a fluorine atom. The fluorinated phenyl group may have one or more fluorine atoms, or may have five.

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

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

The fluorinated alkyldiyl group of R ⁶ can be regarded as a group in which a part or all of the hydrogen atoms of the alkyldiyl group are substituted with fluorine atoms. The carbon number of the fluorinated alkyldiyl group of R ⁶ is not particularly limited, and may be, for example, 1 or more. The carbon number of the fluorinated alkyldiyl group of R ⁶ may be 17 or less, preferably 15 or less, and more preferably 12 or less.

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

An alkyldiyl group or a group in which a carbon-carbon bond and a part of the carbon-hydrogen bond in the fluorinated alkyldiyl group are inserted into an oxygen atom (hereinafter also referred to as an oxygen-containing group of R ⁶ ) may be inserted in one place. The atomic group may be a group inserted at two or more positions.

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

Specific examples of the oxygen-containing group of R ⁶ include, for example, a group containing —CH ₂ CH ₂ O—.

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

An example of a specific example of a compound represented by formula (E-3) is a compound represented by the following formula (E-3-1).

Formula (E-3-1)
[Chemical Formula 19]

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

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

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

R ⁶² is mostly present in formula (E-3-1), but at least one of them is a fluorine atom. Moreover, two or more of R ⁶² may be a fluorine atom, or three or more may be a fluorine atom. Each of R ⁶² may be a fluorine atom.

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

From the viewpoint of low moisture permeability and inkjet coating properties, among the fluorine-containing monomers, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, and 8 are preferred. , 9,9-hexadecylfluoro-1,10-decanediol di (meth) acrylate, (meth) acrylic acid-1H, 1H, 5H-octafluoropentyl ester, and (meth) acrylic acid-1H, One or more of the group consisting of 1H, 2H, 2H-tridecafluorooctyl ester.

In view of the reliability of the organic EL device, the glass transition temperature of the hardened body obtained from the composition of the present embodiment is preferably 65 ° C or higher and 120 ° C or lower, more preferably 65 ° C or higher and 110 ° C or lower, and most preferably 70 ° C or higher and 100 ° C or lower. Below ℃. When the glass transition temperature of the hardened body is in the range of 65 ° C to 120 ° C, when the inorganic passivation film is formed by a method such as CVD on the hardened body of the composition of the present embodiment, the stress will be relaxed, and the inorganic film and the OLED element will be relaxed. It is not easy to peel, so the reliability of the organic EL element is improved.

The method for measuring the glass transition temperature of the hardened body obtained from the composition of the present embodiment is not particularly limited, but it can be measured by a conventional method such as DSC or dynamic viscoelastic spectrum, and it is preferable to use a dynamic viscoelastic spectrum. In the dynamic viscoelastic spectrum, when the stress and strain are applied to the hardened body under a fixed heating rate, the temperature at the peak top showing the loss directly (hereinafter referred to as tan δ) can be used as the glass transition temperature. When the tan δ peak is not shown when the temperature is raised from a sufficiently low temperature of about -150 ° C to a specific temperature (Ta ° C), the glass transition temperature is considered to be -150 ° C or lower or a specific temperature (Ta ° C) or higher. The composition having a glass transition temperature of -150 ° C or lower can be a specific temperature (Ta ° C) or higher.

In order to improve storage stability, the composition of this embodiment can use (D) an antioxidant. Examples of the antioxidant include methylhydroquinone, hydroquinone, 3- [3,5-di-tert-butyl-4-hydroxyphenyl] octadecyl propionate, and 2,2-methylene-bis ( 4-methyl-6-tert-butylphenol), catechol, hydroquinone monomethyl ether, monotertiary butyl hydroquinone, 2,5-tertiary butyl hydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,5-di-tert-butyl-p-benzoquinone, picric acid, citric acid, phenothiazine, tert-butylcatechol, 2-butyl- 4-hydroxyanisole and 2,6-di-tert-butyl p-cresol. The antioxidant is preferably a combination of two or more. From the standpoint of good effects such as transparency and storage stability, among these, phenol-based antioxidants are preferred. Among the phenol-based antioxidants, a hindered phenol-based antioxidant is preferred. The hindered phenol-based antioxidant is preferably 3- [3,5-di-tertiary-butyl-4-hydroxyphenyl] octadecyl propionate, 2,2-methylene-bis (4-methyl- 6-tertiary butyl phenol) in one or more groups, and more preferably 3- [3,5-di-tertiary butyl-4-hydroxyphenyl] octadecyl propionate and 2 , 2-methylene-bis (4-methyl-6-tert-butylphenol). Examples of 3- [3,5-di-tert-butyl-4-hydroxyphenyl] propanoic stearyl ester are "Irganox 1076" manufactured by BASF Japan. Examples of 2,2-methylene-bis (4-methyl-6-tert-butylphenol) include "SUMILIZER MDP-S" manufactured by Sumitomo Chemical Industries, Ltd. Contains 3- [3,5-di-tert-butyl-4-hydroxyphenyl] propanoic stearyl and 2,2-methylene-bis (4-methyl-6-tert-butylphenol) ), 3- [3,5-di-tertiary-butyl-4-hydroxyphenyl] propanoic octadecyl and 2,2-methylene-bis (4-methyl-6-tertiary butyl) Phenyl phenol) contains 3- [3,5-di-tertiary-butyl-4-hydroxyphenyl] propanoic octadecyl and 2,2-methylene-bis (4-methyl-6 -Tertiary butyl phenol) in a total of 100 parts by mass, preferably 3- [3,5-di-tertiary-butyl-4-hydroxyphenyl] propanoic stearyl: 2,2 -Methylene-bis (4-methyl-6-tert-butylphenol) = 10 ~ 90: 90 ~ 10, more preferably 25 ~ 75: 75 ~ 25.

The content of the antioxidant is preferably 0.001 to 3 parts by mass, and more preferably 0.01 to 2 parts by mass, with respect to 100 parts by mass of the components (A) and (B) in total. When it is 0.001 parts by mass or more, storage stability is ensured, and when it is 3 parts by mass or less, good adhesion is obtained, and it does not become unhardened.

The composition according to this embodiment may further contain additives used in this technical field, and for example, it may contain antioxidants, metal deactivators, fillers, stabilizers, neutralizers, lubricants, and antibacterial agents.

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 the present embodiment can be used as a sealant for an organic EL display element.

A method of curing the composition by irradiating visible light or ultraviolet rays includes a method of curing the composition by irradiating at least one of visible light or ultraviolet rays. Examples of energy sources used to irradiate such visible light or ultraviolet light include deuterium lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps, xenon lamps, xenon-mercury hybrid lamps, halogen lamps, excimer lamps, indium lamps, and thallium Energy sources such as lamps, LED lamps, and electrodeless discharge lamps. In view of not harming the organic EL element, the composition of the present embodiment is preferably cured at a wavelength of 380 nm or more, more preferably cured at a wavelength of 395 nm or more, and most preferably cured at a wavelength of 395 nm. The emission of infrared light will increase the temperature of the irradiated part and may cause damage to the organic EL element. Therefore, the wavelength of the energy irradiation source is preferably 500 nm or less. The energy irradiation source is preferably an LED lamp with a single wavelength.

When the composition is cured by irradiating visible light or ultraviolet rays, it is preferred that the composition is cured by irradiating the composition with an energy ray of 100 to 8000 mJ / cm ² at a wavelength of 395 nm. If it is 100 to 8000 mJ / cm ² , the composition will harden and obtain sufficient adhesion strength. If it is 100mJ / cm ² or more, the composition will be sufficiently hardened, if the damage is not ² or less of the organic EL element will 8000mJ / cm. The energy when the composition is hardened is more preferably 300 to 2000 mJ / cm ² .

When the thickness of the organic film is 1 μm or more and 10 μm or less, the composition of the present embodiment has a spectral transmittance in the ultraviolet-visible light region having a transparency of 360 nm to 800 nm, preferably 95% or more, and more preferably 97% or more. The best is more than 99%. If it is 95% or more, an organic EL device having excellent brightness and contrast can be provided.

When an inorganic / organic laminated body is used as one set, the number of the sealing layers composed of the composition of the present embodiment is preferably one to five. When the number of inorganic / organic laminates is six or more, the sealing effect on the organic EL element is almost the same as that of the five groups. The thickness of the inorganic film of the inorganic / organic laminate is preferably 50 nm to 1 μm. The thickness of the organic film of the inorganic / organic laminate is preferably 1 to 15 μm, and more preferably 3 to 10 μm. If the thickness of the organic material film is less than 1 μm, particles generated when the element is formed cannot be completely covered, and it may be difficult to coat the inorganic material film with good flatness. When the thickness of the organic film is more than 15 μm, moisture may enter from the side surface of the organic film, and the reliability of the organic EL element may be reduced.

The sealing substrate is formed so as to cover the entire upper surface of the uppermost organic film of the sealing layer. Examples of the sealing substrate include the aforementioned substrates. Among these, a substrate transparent to visible light is preferred. Among the substrates (transparent sealing substrates) that are transparent to visible light, one or more of the group consisting of a glass substrate and a plastic substrate are preferred, and a glass substrate is more preferred.

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 at a higher level than the sealing layer, it is possible to suppress deterioration caused when the surface of the uppermost organic film is in contact with the gas, and to improve the shielding property of the organic EL device.

Next, a method for 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 specific shape are sequentially formed on a first substrate by a conventional conventional method to form an organic EL element. For example, when an organic EL device is used as a dot matrix display device, a partition wall is formed in order to partition the light emitting regions into a matrix shape, and an organic EL layer including a light emitting layer is formed in a region surrounded by the partition wall.

Next, a first film having a specific thickness is formed on the substrate on which the organic EL element is formed by a film formation method such as a PVD (Physical Vapor Deposition) method such as a sputtering method or a CVD method such as a plasma CVD (Chemical Vapor Deposition) method. Inorganic film. Thereafter, the composition of the present embodiment is adhered to the first inorganic film using a coating film forming method such as a solution coating method or a spray coating method, a flash evaporation method, an inkjet method, or the like. From the viewpoint of productivity, the inkjet method is preferred among these. Thereafter, the composition is hardened by irradiation with ultraviolet rays, energy rays such as electron beams, and plasma, to form a first organic film. Through the above steps, a group of inorganic / organic laminates is formed. The hardening rate of the composition is not particularly limited in order to exert the effects of the present embodiment, and for example, rhenium obtained by a measurement method described later is 90% or more, and preferably 95% or more.

The formation steps of the inorganic / organic laminate shown above are repeated only a certain number of times. However, regarding the last group, that is, the uppermost inorganic / organic laminated body, the composition can be flattened on the upper surface by attaching the composition to the inorganic film by a coating method, a flash evaporation method, an inkjet method, or the like. .

Next, a transparent sealing substrate is bonded to the surface of the substrate to which the composition is adhered. Alignment during bonding. Thereafter, energy rays are irradiated from the transparent sealing substrate side, thereby hardening the composition of the present embodiment between the uppermost inorganic film and the transparent sealing substrate. Thereby, the composition is hardened and an uppermost organic substance film is formed, and at the same time, the uppermost organic substance film is adhered to the transparent sealing substrate. The method of manufacturing an organic EL device is completed in the above manner.

After the composition is adhered to the inorganic film, it can be partially irradiated with energy rays and polymerized. By the above-mentioned method, it is possible to prevent the shape of the composition of the uppermost organic film from being broken 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.

The above description uses the top emission type organic EL device as an example. This embodiment is also applicable to a bottom-emission type organic EL device that emits light generated from an 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 this embodiment, a sealing layer is formed to block the organic EL element formed on the first substrate from outside air, and a transparent sealing substrate is further disposed on the sealing layer, so that a sealing structure can be obtained. It has an organic EL element shielding property against water vapor and oxygen. According to the embodiment of this embodiment, a sealing structure can be obtained which has sufficient adhesion 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 mounted on the non-hardened composition, and the composition is cured thereafter. At the same time, the upper organic film can also be adhered between the sealing layer and the transparent sealing substrate. As a result, compared with the case where the sealing layer and the transparent sealing substrate are bonded with an adhesive, this embodiment has the effect that the steps can be simplified.

The composition of the present embodiment is preferably 350 g / m ² or less in 100 μm thickness moisture permeability measured after the hardened body is exposed to an environment of 85 ° C. and 85% RH for 24 hours in accordance with JIS Z 0208: 1976. When the water vapor transmission rate exceeds 350 g / m ² , moisture may reach the organic light emitting material layer and a dark spot may be generated.

According to this embodiment, it is easy to apply by an inkjet method, and it is possible to provide a sealant for an organic EL display element that is excellent in the reliability of the OLED element, the transparency of the cured body, and the shielding property. According to this embodiment, a method for manufacturing an organic EL display element using a sealant for an organic EL display element can be provided. The inkjet method is a method in which fine droplets are discharged from a nozzle and applied to an object without contact.

(Example)
(Experimental Examples 1 to 8)
The composition was prepared and evaluated by the following method.

(Making of composition)
The materials used in Table 1 were used. The materials used were mixed with the compositions shown in Tables 2 to 3 to prepare a composition. Using the obtained composition, measurement of E-type viscosity, surface tension, water vapor transmission rate, expansion rate of coating area, hardening rate, flatness, transparency, glass transition temperature, and evaluation of organic EL were performed by the following evaluation methods. The results are shown in Tables 2 to 3. The composition names in Tables 2 to 3 use the abbreviations shown in Table 1. The fluorine atom content shown in Tables 2 to 3 is calculated from the composition and expressed on the basis of the total amount of the composition.

〔E-type viscosityη〕
The viscosity of the composition was measured using an E-type viscometer (cone-plate type: cone angle 1 ° 34 ′, radius of cone rotor 24 mm) at a temperature of 25 ° C. and a revolution of 100 rpm.

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

〔Light hardening conditions〕
When the hardened properties of the composition were evaluated, the composition was hardened under the following light irradiation conditions. A hardened body was obtained by light-curing the composition with a 395 nm wavelength LED lamp (UV-LED LIGHT SOURCE H-4MLH200-V1, manufactured by HOYA Corporation) under the condition of a cumulative light amount of 1,500 mJ / cm ² at a wavelength of 395 nm.

[Moisture permeability]
A sheet-like hardened body having a thickness of 0.1 mm was prepared under the aforementioned light hardening conditions, and calcium chloride (anhydrous) was used as a hygroscopic agent in accordance with JIS Z 0208: 1976 "Test method for moisture permeability of moisture-proof packaging materials (cup method)". Measured at 85 ° C ambient temperature and 85% relative humidity.

〔Hardening rate〕
The composition obtained in each experimental example was coated on the alkali-free glass cleaned by the above method to a thickness of 10 μm using the inkjet device described above, and the composition was applied in a size of 10 mm × 10 mm. In a nitrogen environment, curing was performed under the aforementioned light curing conditions, and the curing rate was measured in the following procedure.
An infrared spectrometer (Nicolet is5, DTGS detector, resolution 4cm ^-1 , manufactured by Thermo Scientific, Inc.) was used for the above-mentioned composition after curing and the above-mentioned composition before curing to measure infrared spectrometry. spectrum. In the obtained infrared spectroscopic spectrum, the stretching vibration peak of the methylene carbon-hydrogen bond observed near 2950 cm ^-1 that does not produce a peak change before and after hardening is used as an internal standard, and the peak area before and after hardening of this internal standard belongs to The area before and after hardening of a peak near 810 cm ^-1 of the out-of-plane bending vibration of a carbon-hydrogen bond of a carbon-carbon double bond bonded to a (meth) acrylate was calculated using the following formula.
Hardening rate (%) = [1- (Ax / Bx) / (Ao / Bo)] × 100
here,
Ao: The peak area before hardening near 810 cm ^-1 .
Ax: The peak area after hardening in the vicinity of 810 cm ^-1 .
Bo: The peak area before hardening in the vicinity of 2950 cm ^-1 .
Bx: indicates the peak area after hardening around 2950 cm ^-1 .

〔Transparency〕
The composition obtained in each experimental example was formed in a thickness of 10 μm between two glass plates (alkali-free glass, Eagle XG manufactured by Corning) of 25 mm × 25 mm × 1 mmt (mm thickness), and an LED lamp was used at a wavelength of 395 nm. The amount of irradiated ultraviolet rays was irradiated so as to be 1500 mJ / cm ² , and thereby hardened to obtain a hardened body. The obtained hardened bodies were measured for their spectral transmittances at 380 nm, 412 nm, and 800 nm with an ultraviolet-visible spectrophotometer ("UV-2550" manufactured by Shimadzu Corporation) as transparency.

[Glass transition temperature]
A 1 mm-thick silicon sheet was used as a mold frame, and the composition obtained in each experimental example was sandwiched between PET films. This composition was hardened from the upper surface under the photo-curing conditions, and was further hardened under the photo-curing conditions from below to produce a hardened body having a thickness of 1 mm. The produced hardened body was cut with a cutter to a length of 50 mm and a width of 5 mm, and was used as a hardened body for measuring a glass transition temperature. The obtained hardened body was subjected to a stress and strain in a tensile direction of 1 Hz in a nitrogen environment by a dynamic viscoelasticity measuring device "DMS210" manufactured by SEIKO Electronics Industries Co., Ltd. under a nitrogen environment at a rate of 2 ° C per minute at a heating rate The temperature was raised from -150 ° C to 200 ° C, and tan δ was measured, and the temperature at the peak of the tan δ was used as the glass transition temperature. The peak top of tanδ is the largest ridge in a region where tanδ is 0.3 or more. When tanδ is 0.3 or less in the range from -150 ° C to 200 ° C, and the peak top of tanδ exceeds 200 ° C, the glass transition temperature exceeds 200 ° C (200 <).

[Enlargement rate of coating area]
The composition obtained in each experimental example was applied to a 70 mm × 70 mm × 0.7 mmt substrate (alkali-free glass (Eagle XG manufactured by Corning)) using an inkjet discharge device (MID500B manufactured by Musashi-Engineering Company), and a solvent-based nozzle “MID nozzle” ) The pattern is applied so as to be 4 mm × 4 mm × 10 μmt. Prior to use, the alkali-free glass was washed with acetone and isopropyl alcohol, and then washed with UV-208, a UV ozone cleaning device manufactured by Technovision, for 5 minutes. Immediately after the pattern was applied, it was left for 5 minutes under the conditions of an ambient temperature of 23 ° C. and a relative humidity of 50%, and the flatness after inkjet coating was evaluated by the expansion rate of the coating area (see the following formula). The smaller the expansion ratio of the coating area, the better the shape maintenance and position control property after coating, and the better the evaluation.
(Enlargement rate of coating area) = ((contact area of composition in contact with substrate surface after 5 minutes from application pattern) / (contact area of composition in contact with substrate surface immediately after application of pattern)) × 100 (%)

[Flatness]
A recess of 25 μm × 25 μm × 3 μmt was produced by etching on a substrate (alkali-free glass (Eagle XG) manufactured by Corning Corporation) of 70 mm × 70 mm × 0.7 mmt with an interval of 10 μm from front to back. The substrate was washed with acetone and isopropyl alcohol before use, and then washed with UV-208, a UV ozone cleaning device manufactured by Technovision, for 5 minutes. Next, a 200 nm SiN film was formed on the substrate provided with the recess by a plasma CVD method. Next, the sealant was patterned so that it might become 50 mm x 50 mm x 10 micrometers using the inkjet discharge apparatus (MID500B by a Musashi-Engineering company, solvent-based nozzle "MID nozzle"). After the pattern was applied, it was left for 5 minutes under the conditions of a temperature of 23 ° C and a relative humidity of 50%, and the shape of the sealant coating film was observed. The flatness of the sealant was determined by the following formula. The results are shown in Table 1.
Flatness (%) = (area of sealant coating film after 5 minutes of standing) / (50mm × 50mm)
In addition, for example, 50% flatness means that a part of the sealant of the applied pattern is popped open and the SiN film is exposed in half (50%) of a range of 50 mm × 50 mm.

[Evaluation of Organic EL]

[Fabrication 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. Thereafter, the following compounds were sequentially deposited as a thin film by a vacuum evaporation method to obtain a 2 mm square organic EL element composed of an anode / hole injection layer / hole transport layer / light emitting layer / electron injection layer / cathode. Of the substrate. The structure of each layer is as follows.
･ Anode: ITO, film thickness of anode: 150nm
Holmium hole injection layer: 4,4 ', 4 "-tri {2-naphthyl (phenyl) amino} triphenylamine (2-TNATA)
･ Hole transport layer: N, N'-diphenyl-N, N'-dinaphthylbenzidine (α-NPD)
･ Light-emitting layer: tris (8-hydroxyquinoline) aluminum (metal complex material). The film thickness of the light-emitting layer is 1000Å. The light-emitting layer also functions as an electron transport layer. Electron injection layer: lithium fluoride. Cathode: Aluminum film thickness: 150nm.

[Fabrication of Organic EL Elements]
Thereafter, a mask (cover) having an opening portion of 10 mm × 10 mm was provided so as to cover an organic EL element of 2 mm × 2 mm, and a SiN film was formed by a plasma CVD method. Next, the composition (organic film) obtained in each experimental example was coated with a thickness of 10 μm so as to cover a 2 mm × 2 mm organic EL element using the inkjet device under a nitrogen environment, and the composition was cured under the aforementioned light hardening conditions to cover the composition. A mask (cover) having an opening portion of 10 mm × 10 mm was provided as a whole of the cured body, and a SiN film was formed by a plasma CVD method to obtain an organic EL display element.

The thickness of the formed SiN (inorganic film) was about 1 μm. Thereafter, a 30 mm × 30 mm × 25 μmt transparent substrate-free double-sided tape was bonded to 30 mm × 30 mm × 0.7 mmt alkali-free glass (Egg XG manufactured by Corning) to produce an organic EL device (organic EL evaluation).

[Initial]
A voltage of 6 V was applied to the produced organic EL element, and the light-emitting state of the organic EL element was observed with a visual observation and a microscope, and the diameter of the dark spot was measured.

〔Durability〕
The produced organic EL element was exposed to the conditions of 85 ° C. and a relative humidity of 85% by mass for 70 hours, and then a voltage of 6 V was applied. The light-emitting state of the organic EL element was observed visually and with a microscope, and the diameter of the dark spot was measured.

The diameter of the dark spot can be used as an evaluation index to evaluate the degree to which the sealant penetrates the pinholes of the passivation layer and the degree to which moisture in the sealant is discharged as outgassing. The diameter of the dark spots evaluated is preferably 300 μm or less, more preferably 50 μm or less, and most preferably no dark spots are present.

From the above experimental example, the following matters are known.

The composition according to the present embodiment can provide a composition that is excellent in the reliability of an organic EL element, the dischargeability of high-precision inkjet, the shape maintenance property after inkjet coating, and the low moisture permeability.

(A) an acyclic alkanediol dimethacrylate having a carbon number of 6 or more, (B) a cyclic monofunctional (meth) acrylate and a cyclic bifunctional (meth) acrylate, and In the formulae (I) to (III), the reliability, the ink jetting property, the shape maintenance property, and the low moisture permeability were all excellent (Experimental Examples 1 to 3, 10 to 11).

It is found that when (E) is further contained, the surface free energy of the sealant is reduced by the fluorinated monomer, and it is easy to follow the fine unevenness, thereby improving the flatness (Experimental Examples 4 to 9).

On the other hand, when (A) an acyclic alkanediol di (meth) acrylate having less than 6 carbon atoms is used, the coating area has a large expansion rate, and the shape cannot be maintained after inkjet coating, that is, the shape is maintained Sexual problems (Experimental Example 12). When the content of the component (A) exceeds 85 parts by mass and the content of the component (B) is less than 15 parts by mass, the viscosity is low and does not satisfy the formula (III), and shape retention and reliability are not obtained (Experimental example) 13). (B) When a cyclic monofunctional (meth) acrylate is not used and a long-chain alkyl monofunctional acrylate and a cyclic difunctional methacrylate are used, the viscosity is low and the formula (III) is not satisfied, which cannot be obtained. Reliability, shape maintenance, and low moisture permeability (Experimental Example 14). (A) an acyclic alkanediol dimethacrylate having a carbon number of 6 or more and (B) two types of cyclic (meth) acrylates are used, and the formulas (II) to (III) are satisfied and the viscosity exceeds At 50 mPa ･ s, although it is excellent in low moisture permeability, it cannot be ejected by inkjet, and reliability and shape retention cannot be evaluated (Experimental Example 15). (B) When the cyclic monofunctional acrylate is not used and only the cyclic monofunctional acrylate is used, and the formulae (I) to (III) are satisfied, the transparency and shape retention are poor (Experimental Example 16).

[Table 1]

[Table 2]

[table 3]

[Industrial availability]
The composition of this embodiment is excellent in high-precision inkjet ejection properties, and is excellent in flatness after inkjet coating, has low moisture permeability and transparency, and prevents the organic EL element from being deteriorated. In this embodiment, inkjet coating can be performed in a short time. The composition of this embodiment is suitable for use in electronic products, especially display parts such as organic EL (for example, flexible displays or organic EL devices used in wearable products), or electronics such as CCD and CMOS so-called image sensors. Adhesion of components, used in semiconductor components, etc. In particular, it is most suitable for organic EL sealing, and it satisfies the characteristics required for an adhesive for element packaging such as an organic EL element or a coating agent for element packaging.

The composition described above is one aspect of this embodiment, and the sealant, hardened body, organic EL device, display, and manufacturing method for the organic EL element of this embodiment also have the same configuration and effect.

Claims (29)

An encapsulant for an organic electroluminescence display element comprising (A) an acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) photopolymerization Initiator (B) the cyclic monomer contains a cyclic monofunctional (meth) acrylate and a cyclic difunctional (meth) acrylate, And simultaneously satisfy the following mathematical formulae (I) and (III), 8mPa ･ s ≦ η ≦ 50mPa ･ s… (I) γ / 2η ＜ 0.9m / s… (III) (In the formula, η represents a viscosity measured by an E-type viscometer at 25 ° C, and γ represents a static surface tension measured by a hanging drop method). An encapsulant for an organic electroluminescence display element comprising (A) an acyclic alkanediol di (meth) acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) photopolymerization Initiator With respect to 100 parts by mass of (A) component and (B) component in total, containing 10 to 85 parts by mass of (A) component and 15 to 90 parts by mass of (B) component, (B) the cyclic monomer contains a cyclic monofunctional (meth) acrylate and a cyclic difunctional (meth) acrylate, The content ratio of the cyclic monofunctional (meth) acrylate and the cyclic difunctional (meth) acrylate is 100 mass in total of the cyclic monofunctional (meth) acrylate and the cyclic difunctional (meth) acrylate. In terms of mass ratio, parts are cyclic monofunctional (meth) acrylate: cyclic bifunctional (meth) acrylate = 10 ~ 95: 90 ~ 5, and At the same time satisfy the following mathematical formulae (I), (II) and (III), 8mPa ･ s ≦ η ≦ 50mPa ･ s… (I) 14mN / m ≦ γ ≦ 40mN / m… (II) γ / 2η ＜ 0.9m / s… (III) (In the formula, η represents a viscosity measured by an E-type viscometer at 25 ° C, and γ represents a static surface tension measured by a hanging drop method). The sealant for an organic electroluminescence display device according to item 1 or 2 of the scope of patent application, wherein the (B) cyclic monomer contains one or more types of alicyclic monomers. The sealant for an organic electroluminescence display device according to any one of claims 1 to 3, wherein the component (E) contains a fluorine-containing monomer having a fluorine atom and a (meth) acrylfluorenyl group. body. The sealant for an organic electroluminescence display device according to item 4 of the scope of the patent application, wherein the fluorine atom content of the fluorine-containing monomer is 2 to 70% by mass based on the total amount of the fluorine-containing monomer. The sealant for an organic electroluminescence display device according to item 4 or 5 of the scope of patent application, wherein the fluorine-containing monomer contains a compound represented by the formula (E-1) and a compound represented by the formula (E-2) And at least one selected from the group consisting of compounds represented by formula (E-3), formula (E-1) [Chemical Formula 1] [In the formula (E-1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a fluorinated alkyl group, or a carbon-carbon bond and a part of the carbon-hydrogen bond in the fluorinated alkyl group are inserted into an oxygen atom. Group], Formula (E-2) [Chemical Formula 2] [In the formula (E-2), R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents a fluorinated alkyldiyl group, or a part of the carbon-carbon bond and the carbon-hydrogen bond inserted in the fluorinated alkyldiyl group. An oxygen atom group, most of R ³ existing are the same or different from each other], Formula (E-3) [Chemical Formula 3] [In formula (E-3), R ⁵ represents a hydrogen atom or a methyl group, and R ⁶ represents a single bond, an alkanediyl group, a fluorinated alkanediyl group, or a carbon-carbon in an alkanediyl group or a fluorinated alkanediyl group. A group in which an oxygen atom is partially inserted into a bond or a carbon-hydrogen bond, and Ar ¹ represents a fluorinated aryl group]. The sealant for an organic electroluminescence display device according to item 6 of the scope of the patent application, wherein the fluorine-containing monomer contains a compound represented by the formula (E-1-1) and a compound represented by the formula (E-2-1) At least one selected from the group consisting of a compound represented by Formula (E-3-1), and a compound represented by Formula (E-3-1), Formula (E-1-1) [Chemical Formula 4] [In the formula (E-1-1), R ¹ represents a hydrogen atom or a methyl group, R ²¹ represents a hydrogen atom or a fluorine atom, and n represents an integer of 1 or more. Most of the R ²¹ are the same or different from each other, but at least One R ²¹ is a fluorine atom], formula (E-2-1) [chemical formula 5] [In the formula (E-2-1), R ³ represents a hydrogen atom or a methyl group, R ⁴¹ represents a hydrogen atom or a fluorine atom, and m represents an integer of 1 or more. Most of the R ⁴¹ are the same or different from each other, and most of them exist. R ³ are the same or different from each other, but at least one R ⁴¹ is a fluorine atom], Formula (E-3-1) [Chemical Formula 6] [In formula (E-3-1), R ⁵ represents a hydrogen atom or a methyl group, R ⁶¹ represents a hydrogen atom or a fluorine atom, R ⁶² represents a hydrogen atom or a fluorine atom, p represents an integer of 0 or more, and most of R ⁶¹ exist In order to be the same or different from each other, most of R ⁶² existing are the same or different from each other, but at least one R ⁶² is a fluorine atom]. The sealant for an organic electroluminescence display device according to any one of claims 4 to 7, in which the content of (E) component is 100 parts by mass with respect to (A) component and (B) component in total. The amount is in the range of 0.1 to 10 parts by mass. The sealant for an organic electroluminescence display device according to any one of claims 4 to 8 in the scope of patent application, wherein the component (E) contains 2,2,3,3,4,4,5,5, 6,6,7,7,8,8,9,9-Hexadecafluoro-1,10-decanediol di (meth) acrylate, (meth) acrylic acid-1H, 1H, 5H-octafluoropentane One or more selected from the group consisting of esters and (meth) acrylic acid-1H, 1H, 2H, 2H-tridecafluorooctyl ester. The sealant for an organic electroluminescence display element according to any one of claims 1 to 9 of the scope of application for a patent, wherein the sealant is applied using an inkjet method. The sealant for an organic electroluminescence display device according to any one of claims 1 to 10, which does not contain a bifunctional (meth) acrylate oligomer or a bifunctional (meth) acrylate Polymers, polyfunctional (meth) acrylate oligomers, or polyfunctional (meth) acrylate polymers. The sealant for an organic electroluminescence display element according to any one of claims 1 to 11, wherein the glass transition temperature of the cured body is 65 ° C or higher and 120 ° C or lower. The sealant for an organic electroluminescence display element according to any one of claims 1 to 12, in which at least one of the (B) components has two or more ring structures in the molecule. The sealant for an organic electroluminescence display device according to any one of claims 1 to 13, in which at least two of the (B) components have two or more ring structures in the molecule. The sealant for an organic electroluminescence display element according to any one of claims 1 to 14, wherein the component (B) contains an ethoxylated o-phenylphenol (meth) acrylate, ( M-phenoxy benzyl methacrylate, tricyclodecane dimethanol di (meth) acrylate, and ethoxylated bisphenol A di (meth) acrylate represented by the following structural formula 1 or more of [Chemical Formula 7] (R in the formula is independently a hydrogen atom or a methyl group. For m and n in the formula, m + n = 2 to 10). The sealant for an organic electroluminescence display device according to any one of claims 1 to 15, wherein the component (A) is an alkanediol di (meth) acrylate having a carbon number of 12 or less. The sealant for an organic electroluminescence display device according to any one of claims 1 to 16, wherein the component (A) contains 1,9-nonanediol di (meth) acrylate, 1 One or more of the group consisting of 10-decanediol di (meth) acrylate and 1,12-dodecanediol di (meth) acrylate. The sealant for an organic electroluminescence display device according to any one of claims 1 to 17, wherein the component (C) contains 2,4,6-trimethylbenzyl-diphenyl -Phosphine oxide. The sealant for an organic electroluminescence display element according to any one of claims 1 to 18 in the scope of the patent application, wherein the content of the component (C) is 0.5 to 4 parts by mass. The sealant for an organic electroluminescence display device according to any one of claims 1 to 19, further comprising (D) an antioxidant. The sealing agent for an organic electroluminescence display device according to item 20 of the scope of application for a patent, wherein the component (D) is a hindered phenol-based antioxidant. The sealant for an organic electroluminescence display device according to any one of claims 20 to 21, which contains two or more (D) components. The sealant for an organic electroluminescence display element according to any one of claims 1 to 22 in the scope of patent application, wherein the sealant is cured at a wavelength of 395 nm to 500 nm. The sealant for an organic electroluminescence display element according to item 23 of the scope of application for a patent, wherein the sealant for an 395 nm LED lamp is hardened. A hardened body is obtained by hardening the sealant for an organic electroluminescence display element according to any one of claims 1 to 24 of the scope of patent application. An organic EL device includes a hardened body described in item 25 of the scope of patent application. A display includes a hardened body described in item 25 of the patent application. A flexible display includes a hardened body described in item 25 of the scope of patent application. A flexible organic EL device includes a hardened body as described in item 25 of the scope of patent application.