KR20200078559A - Encapsulant for organic electroluminescent display elements - Google Patents

Abstract

(A) an acyclic dialkanediol di(meth)acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator, and (B) the cyclic monomer with a cyclic monofunctional (meth)acrylate An encapsulant for an organic electroluminescence display device containing a cyclic bifunctional (meth)acrylate and satisfying both of the following formulas (I) and (III). 8mPa·s≤η≤50mPa·s··(I) γ/2η<0.9m/s··(III) (Wherein, η represents the viscosity measured by an E-type viscometer at 25°C, γ Represents the static surface tension measured by the pendant drop method.)

Description

Encapsulant for organic electroluminescent display elements

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

The organic electroluminescent (EL) device (also referred to as an OLED device) is attracting attention as a device body capable of emitting high luminance. However, there has been a problem that the OLED device is deteriorated by moisture and the luminescence properties are lowered.

In order to solve such a problem, a technique for preventing degradation due to moisture by encapsulating an organic EL device has been studied. For example, the method of sealing with the sealing material which consists of frit glass is mentioned (refer patent document 1).

An organic electroluminescence display device (refer to Patent Document 2), wherein the encapsulation layer is a stack of at least a barrier layer, a resin layer, and a barrier layer sequentially formed. An organic EL device (refer to Patent Document 3), characterized by comprising a stacked encapsulation layer and an encapsulation glass substrate disposed in close contact with the top organic material film of the encapsulation layer so as to cover the entire upper surface of the top organic material film is proposed. have.

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

Patent Document 1: Japanese Patent Publication No. Hei 10-74583 Patent Document 2: Japanese Unexamined Patent Publication No. 2001-307873 Patent Document 3: Japanese Patent Publication No. 2009-37812 Patent Document 4: Japanese Patent Publication No. 2014-225380 Patent Document 5: Japanese Patent Publication No. 2012-190612 Patent Document 6: Japanese Patent Publication No. 2014-229496 Patent Document 7: Japanese Patent Publication No. 2014-196387 Patent Document 8: Japanese Patent Publication No. 2014-193970 Patent Document 9: Japanese Patent Publication No. 2014-193971 Patent Document 10: Publication of WO2014/157642 Patent Document 11: US2017/0062762 Publication

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

In the patent document 1, when mass production is performed, a method of sealing the outer circumference by inserting the organic EL element into a base material having low moisture permeability, for example, glass, is employed. In this case, since this structure has a hollow encapsulation structure, there is a problem that moisture cannot be prevented from entering the hollow encapsulation structure, leading to deterioration of the organic EL element.

In Patent Documents 2 to 3, since the organic film is formed by vapor deposition, there is a problem that the thickness of the organic film becomes 3 μm or less. When the thickness of the organic material film was 3 μm or less, not only the particles generated at the time of device formation could not be completely covered, but it was also difficult to apply while maintaining the flatness on the inorganic material film.

In Patent Document 4, an encapsulant using an epoxy-based material has been proposed, but these materials require heating in order to cure, thereby damaging the organic EL device and having a problem in terms of yield. In Patent Document 5, a photo-curable encapsulant using an epoxy-based material is proposed. Since these materials are cured by UV light, the organic EL device is damaged by UV light and there is a problem in terms of yield.

In Patent Documents 6 to 10, there is a description of reducing the water vapor transmission rate as a property required for such an encapsulation material, but regarding the problem and countermeasures to reduce the reliability of the organic EL device by penetrating the encapsulation material itself from the pinhole of the passivation film. There is no mention.

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

Thus, in the above-mentioned conventional technology, it has been a problem from the past that it is impossible to achieve both the ejection property when using inkjet and the reliability of the organic EL device.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a composition excellent in both ejection and reliability of an organic EL element when inkjet is used, for example, when used for sealing an organic EL element.

The present invention can provide the following.

<1> (A) containing an acyclic alkanediol di(meth)acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator,

(B) The cyclic monomer contains a cyclic monofunctional (meth)acrylate and a cyclic bifunctional (meth)acrylate,

An encapsulant for an organic electroluminescence display device satisfying both of the following formulas (I) and (III).

8mPa·s≤η≤50mPa·s ···(I)

γ/2η<0.9m/s ···(III)

(Wherein, η represents the viscosity measured by an E-type viscometer at 25°C, and γ represents the static surface tension measured by the pendant drop method.)

<2> (A) containing an acyclic alkanediol di(meth)acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator,

(A) 10-85 parts by mass of the component (A) and 15-90 parts by mass of the component (B) with respect to 100 parts by mass of the component (A) and (B),

(B) The cyclic monomer contains a cyclic monofunctional (meth)acrylate and a cyclic bifunctional (meth)acrylate,

The content ratio of the cyclic monofunctional (meth)acrylate and the cyclic bifunctional (meth)acrylate is a cyclic monofunctional (mass ratio) in a mass ratio of 100 parts by mass of the total of the cyclic monofunctional (meth)acrylate and the cyclic bifunctional (meth)acrylate ( Meth)acrylate: cyclic bifunctional (meth)acrylate = 10 to 95: 90 to 5, and

An encapsulant for an organic electroluminescence display device satisfying all of the following formulas (I), (II) and (III).

8mPa·s≤η≤50mPa·s ···(I)

14mN/m≤γ≤40mN/m ···(II)

γ/2η<0.9m/s ···(III)

(Wherein, η represents the viscosity measured by an E-type viscometer at 25°C, and γ represents the static surface tension measured by the pendant drop method.)

<3> The sealing agent for the organic electroluminescence display element according to <1> or <2>, wherein (B) the cyclic monomer contains at least one alicyclic monomer.

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

<5> The sealing agent for organic electroluminescence display elements 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 fluorine-containing monomer contains at least one member selected from the group consisting of a compound represented by formula (E-1), a compound represented by formula (E-2), and a compound represented by formula (E-3), The sealing agent for organic electroluminescence display elements as described in <4> or <5>.

Formula (E-1)

[In formula (E-1),

R ¹ represents a hydrogen atom or a methyl group,

R ² represents a group in which an oxygen atom is inserted in a part of a carbon-carbon bond and a carbon-hydrogen bond in a fluorinated alkyl group or a fluorinated alkyl group. The plural R ³ may be the same or different from each other.]

Formula (E-2)

[In formula (E-2),

R ³ represents a hydrogen atom or a methyl group,

R ⁴ represents a group in which an oxygen atom is inserted in a part of a carbon-carbon bond and a carbon-hydrogen bond in a fluorinated alkanediyl group or a fluorinated alkanediyl group. The plural R ³ may be the same or different from each other.]

Formula (E-3)

[In formula (E-3),

R ⁵ represents a hydrogen atom or a methyl group,

R ⁶ represents a single bond, an alkanediyl group, an alkanediyl fluoride group, or an alkanediyl group or a group in which an oxygen atom is inserted in a part of the carbon-carbon bond and the carbon-hydrogen bond in the alkanediyl group,

Ar ¹ represents a fluorinated aryl group.]

<7> The fluorine-containing monomer is at least selected from the group consisting of a compound represented by formula (E-1-1), a compound represented by formula (E-2-1), and a compound represented by formula (E-3-1). The sealing agent for organic electroluminescence display elements as described in <6> containing 1 type.

Formula (E-1-1)

[In 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. The plural R ^21s may be the same or different from each other. Provided that at least one of R ²¹ is a fluorine atom.]

Formula (E-2-1)

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

Formula (E-3-1)

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

<8> Any of <4> to <7>, characterized in that the content of the component (E) is in the range of 0.1 parts by mass to 10 parts by mass relative to 100 parts by mass of the components (A) and (B) in total. The encapsulant for organic electroluminescence display elements described in one.

<9> (E) component is 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluoro-1,10-decane Diol di(meth)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate and 1H,1H,2H,2H-tridecafluorooctyl (meth)acrylate The sealing agent for organic electroluminescence display elements in any one of <4>-<8> characterized by including the above.

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

<11> <1>, which does not contain a bifunctional (meth)acrylate oligomer, a bifunctional (meth)acrylate polymer, a polyfunctional (meth)acrylate oligomer or a polyfunctional (meth)acrylate polymer, The sealing agent for organic electroluminescence display elements in any one of -<10>.

<12> The sealing agent for organic electroluminescence display elements according to any one of <1> to <11>, wherein the cured body has a glass transition temperature of 65°C or higher and 120°C or lower.

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

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

<15> (B) component is ethoxylated-o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ethoxy represented by the following structural formula A sealing agent for an organic electroluminescence display element according to any one of <1> to <14>, characterized in that it contains at least one of the group consisting of cyclized bisphenol A di(meth)acrylate.

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

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

<17> Group (A) is composed of 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and 1,12-dodecanediol di(meth)acrylate A sealing agent for an organic electroluminescence display element according to any one of <1> to <16>, characterized in that it contains at least one of them.

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

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

<20> (D) A sealing agent for an organic electroluminescence display element according to any one of <1> to <19>, further comprising an antioxidant.

<21> The sealing agent for organic electroluminescent display elements according to <20>, wherein the component (D) is a hindered phenol-based antioxidant.

<22> The sealing agent for organic electroluminescent display elements according to <20> or <21>, characterized in that it contains two or more components (D).

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

<24> The sealing agent for organic electroluminescence display elements according to <23>, which is cured with a 395nm LED lamp.

<25> Hardened|cured material formed by hardening the sealing agent for organic electroluminescence display elements in any one of <1>-<24>.

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

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

<28> A display having flexibility, comprising the cured body according to <25>.

<29> An organic EL device having flexibility, comprising the cured product according to <25>.

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

The present embodiment will be described below. Numeric ranges described in this specification are intended to include upper and lower limits unless otherwise specified. In this specification, unless otherwise specified, it is defined below. The (meth)acrylate represents acrylate or methacrylate, and the notation such as "(meth)acryloyloxy" or "(meth)acrylamide" has the same meaning. "Monofunctional (meth)acrylate" refers to (meth)acrylate having one (meth)acrylic group, and "bifunctional (meth)acrylate" refers to (meth)acrylate having two (meth)acrylic groups. Point. "Polyfunctional (meth)acrylate" refers to (meth)acrylate having three or more (meth)acrylic groups, and it is assumed that bifunctional (meth)acrylate is not included.

Hereinafter, an organic EL device of the top emission type that emits light from the opposite side of the substrate of the organic EL element formed on the substrate will be described as an example. In the top emission type organic EL device, an organic EL element including an anode and a light emitting layer and a cathode on a substrate are sequentially stacked, and an encapsulation layer composed of a laminated film of an inorganic material film and an organic material film covering the entire organic EL device. And, the sealing substrate is installed on the sealing layer has a structure formed in sequence.

Various substrates, such as a glass substrate, a silicon substrate, and a plastic substrate, can be used. Among these, at least 1 type is preferable among the group which consists of a glass substrate and a plastic substrate, and a glass substrate is more preferable.

Plastics used for plastic substrates include polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, polyoxadiazole, aromatic polyamide, polybenzoimidazole, polybenzobisthiazole, polybenzoxazole, polythiazole, And polyparaphenylene vinylene, polymethyl methacrylate, polystyrene, polycarbonate, polycycloolefin, and polyacrylic. Among them, polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, polyoxadiazole, aromatic polyamide, polybenzoimidazole, polybenzobisthiazole, poly, from the viewpoint of low moisture permeability, low oxygen permeability, and heat resistance. One or more of the group consisting of benzoxazole, polythiazole, and polyparaphenylene vinylene is preferable, and polyimide, polyetherimide, polyethylene terephthalate, and polyethylene are preferable because of high energy ray permeability such as ultraviolet light or visible light. One or more of the groups consisting of naphthalate are more preferable.

As the anode, a relatively large work function (it is suitable to have a work function greater than 4.0 eV), a conductive metal oxide film or a translucent metal thin film is generally used. Examples of the material of the anode 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 an organic transparent conductive film such as an alloy containing at least one of these, polyaniline or a derivative thereof, polythiophene or a derivative thereof, and the like. The anode can be formed by a layer structure of two or more layers, if necessary. The film thickness of the anode can be appropriately selected in consideration of the electrical conductivity (in the case of a bottom emission type, the transmittance of light). The film thickness of the anode is preferably 10 nm to 10 μm, more preferably 20 nm to 1 μm, and most preferably 50 nm to 500 nm. Examples of the method for producing the anode include vacuum deposition, sputtering, ion plating, and plating. In the case of a top emission type, a reflective film for reflecting light emitted to the substrate side may be provided under the anode.

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

(Pigment-based material)

Examples of the dye-based material include cyclophendamine derivatives, tetraphenylbutadiene derivative compounds, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyrylarylene derivatives, pyrrole derivatives, thiophene ring compounds, and pyridine Ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifumanylamine derivatives, oxadiazole dimers, pyrazoline dimers, and the like.

(Metal complexing system material)

As the metal complexing system material, metal complexes having luminescence from triplet excitation states such as iridium complexes, platinum complexes, aluminoquinolol complexes, benzoquinolinol beryllium complexes, benzooxazolyl zinc complexes, benzothiazole zinc complexes, azo And metal complexes such as methyl zinc complex, porphyrin zinc complex, and europium complex. As the metal complex, rare earth metals such as terbium (Tb), europium (Eu), and dysprosium (Dy) are contained in the central metal, aluminum (Al), zinc (Zn), beryllium (Be), and the like, and oxadiazole and thia are used as ligands. And metal complexes having a diazole, phenylpyridine, phenylbenzoimidazole, quinoline structure, and the like. Among these, a metal complex having aluminum (Al) as the central metal and a quinoline structure as a ligand is preferable. Among metal complexes having aluminum (Al) in the center metal and a quinoline structure in the ligand, tris (8-hydroxyquinolinato) aluminum is preferred.

(Polymer materials)

Examples of the polymer material include polyparaphenylenevinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and light emitting materials for the pigment or metal complex system. And polymerized ones.

Among the luminescent materials, distyrylarylene derivatives, oxadiazole derivatives, polyvinylcarbazole derivatives, polyparaphenylene derivatives, polyfluorene derivatives, and polymers thereof are exemplified as blue emitting materials. Among these, polymer materials are preferred. Among the polymer materials, at least one of the polyvinyl carbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives is preferred.

Examples of materials emitting green light include quinacridone derivatives, coumarin derivatives, polyparaphenylenevinylene derivatives, polyfluorene derivatives, and polymers thereof. Among these, polymer materials are preferred. Among the polymer materials, at least one of the groups consisting of polyparaphenylenevinylene derivatives and polyfluorene derivatives is preferable.

Materials that emit red light include coumarin derivatives, thiophene ring compounds, polyparaphenylenevinylene derivatives, polythiophene derivatives, polyfluorene derivatives, and polymers thereof. Among these, polymer materials are preferred. Among the polymer materials, at least one of the groups consisting of polyparaphenylenevinylene derivatives, polythiophene derivatives, and polyfluorene derivatives is preferable.

(Dopant material)

Examples of dopant materials include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squarylium derivatives, porphyrin derivatives, styryl-based pigments, tetracene derivatives, pyrazolone derivatives, decacyclene, and phenoxazone. have.

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

(Hole injection layer)

As a material for forming the hole injection layer, phenylamine, starburst amine, phthalocyanine, vanadium oxide, molybdenum oxide, oxide such as 4',4"-tris{2-naphthyl(phenyl)amino}triphenylamine And oxides such as ruthenium and aluminum oxide, amorphous carbon, polyaniline, and polythiophene derivatives.

(Hole transport layer)

As a material constituting the hole transport layer, polyvinylcarbazole or its derivatives, polysilane or its derivatives, polysiloxane derivatives having aromatic amines in the side chain or main chain, pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine derivatives, benzidine Derivatives, polyaniline or derivatives thereof, polythiophene or derivatives thereof, polyarylamine or derivatives thereof, polypyrrole or derivatives thereof, poly(p-phenylenevinylene) or derivatives thereof, poly(2,5-thienylenevinylene) Or derivatives thereof.

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

(Electron transport layer)

Examples of the material constituting the electron transport layer include an oxadiazole derivative, anthraquinodimethane or a derivative thereof, benzoquinone or a derivative thereof, naphthoquinone or a derivative thereof, anthraquinone or a derivative thereof, tetracyanoanthraquinodimethane or a derivative thereof, Fluorenone derivatives, diphenyldicyanoethylene or its derivatives, diphenoquinone derivatives, 8-hydroxyquinoline or its derivatives, polyquinoline or its derivatives, polyquinoxaline or its derivatives, polyfluorene or its derivatives, and the like. have. Metal complexes etc. are mentioned as a derivative. Among these, 8-hydroxyquinoline or a derivative thereof is preferable. Among 8-hydroxyquinoline or its derivatives, tris(8-hydroxyquinolinato)aluminum is preferable because it can be used as an organic substance that emits fluorescence or phosphorescence in the light emitting layer.

(Electron injection layer)

As the electron injecting layer, depending on the type of the light emitting layer, an electron injecting layer having a single layer structure of a calcium (Ca) layer, or a metal of group IA and IIA of the periodic table and a metal having a work function of 1.5 to 3.0 eV and oxides and halides of the metal And a single layer structure of a layer formed of at least one of the group consisting of carbonates, or a group consisting of metals of group IA and IIA of the periodic table and having a work function of 1.5 to 3.0 eV and oxides, halides and carbonates of the metals And an electron injection layer formed of a layered structure of a layer formed of one or more of the above and a Ca layer. Metals 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 or oxides, halides, and carbonates of the periodic table 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 these electron transport layers or electron injection layers have a function of blocking the transport of holes, these electron transport layers or electron injection layers are also referred to as hole block layers.

As the cathode, a transparent or translucent material having a relatively small work function (it is suitable to have a work function less than 4.0 eV) and easy electron injection into the light emitting layer is preferred. Lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), and barium as negative electrode materials (Ba), aluminum (Al), scandium (Sc), vanadium (V), zinc (Zn), yttrium (Y), indium (In), cerium (Ce), samarium (Sm), europium (Eu), terbium Metals such as (Tb), ytterbium (Yb), or alloys of two or more of the above metals, or one or more of them and gold (Au), silver (Ag), platinum (Pt), copper (Cu), and chromium Alloy consisting of one or more of (Cr), manganese (Mn), titanium (Ti), cobalt (Co), nickel (Ni), tungsten (W), tin (Sn), or graphite or graphite interlayer compounds, or ITO And metal oxides such as tin oxide.

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

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

(i) anode/hole transport layer/light emitting layer/cathode

(ii) anode/light emitting layer/electron transport layer/cathode

(iii) anode/hole transport layer/light emitting layer/electron transport layer/cathode

(iv) anode/hole injection layer/light emitting layer/cathode

(v) anode/light emitting layer/electron injection layer/cathode

(vi) anode/hole injection layer/light emitting layer/electron injection layer/cathode

(vii) anode/hole injection layer/hole transport layer/light emitting layer/cathode

(viii) anode/hole transport layer/light emitting layer/electron injection layer/cathode

(ix) anode/hole injection layer/hole transport layer/light emitting layer/electron injection layer/cathode

(x) anode/hole injection layer/light emitting layer/electron transport layer/cathode

(xi) anode/light emitting layer/electron transport layer/electron injection layer/cathode

(xii) anode/hole injection layer/light emitting layer/electron transport layer/electron injection layer/cathode

(xiii) anode/hole injection layer/hole transport layer/light emitting layer/electron transport layer/cathode

(xiv) anode/hole transport layer/light emitting layer/electron transport layer/electron injection layer/cathode

(xv) anode/hole injection layer/hole transport layer/light emitting layer/electron transport layer/electron injection layer/cathode

(Here, "/" indicates that each layer is stacked adjacently. The same applies hereinafter.)

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

In an active matrix type display device in which the current to each organic EL element is controlled by a thin film transistor (TFT) provided for each pixel, irregularities of 0.5 μm to 3 μm due to partition walls partitioning TFTs, blue, green, and red pixels are formed. It is present between the cathode or anode and the encapsulation layer. In the active matrix type display device, it is necessary to flatten the above-described irregularities by the sealing layer to reduce the effect of interference with light emission, and further improve the sealing performance. When the said sealing layer is formed with the sealing agent which concerns on this embodiment, the effect of obtaining favorable flatness can be exhibited.

The inorganic/organic layered inorganic film is a film provided to prevent the organic EL element from being exposed to a gas such as water vapor or oxygen existing in an environment where the organic EL device is placed. It is preferable that the inorganic/organic layered inorganic film is 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 a laminated film of these.

The organic material film of the inorganic/organic laminate is provided to cover the defects such as pinholes formed on the inorganic material film and to impart flatness to the surface. The organic material film is formed in a region narrower than the region where the inorganic material film is formed. This is because if the organic material film is formed to be the same as or wider than the formation area of the inorganic material film, the organic material film is deteriorated in the exposed area. However, the uppermost organic film formed on the uppermost layer of the entire encapsulation layer is formed in an area substantially the same as the formation area of the inorganic film. Then, the top surface of the encapsulation layer is formed to be flat. As the organic material film, a composition having an adhesion function with good adhesion to the inorganic material film described above is used.

This embodiment is suitable, for example, for inkjet coating capable of applying excellent flatness with a film thickness of 3 μm or more in a short period of time, excellent ejection by inkjet, flatness after inkjet coating, and barrier properties against water vapor (hereinafter also referred to as low moisture permeability) In addition, it is an object of the present invention to provide an encapsulant for an organic electroluminescence display element that forms the organic substance film, in which the encapsulant itself penetrates from a pinhole on the inorganic substance film and the reliability of the organic EL element is not deteriorated. . When the coating method by the inkjet method is used, an organic film can be uniformly formed at high speed.

When the encapsulant permeates itself from the pinhole on the inorganic film, the OLED element around the pinhole does not emit light, and when used for a long time, the encapsulant penetrates into the organic light emitting material layer, which increases the luminous defect and causes so-called dark spots. do. That is, the reliability of the OLED device is significantly reduced.

However, according to Lucas-Washburn (Equation 1), the basic formula of liquid infiltration, the depth of penetration (l) into the pinhole is the time (t) after the liquid reaches the solid, and the hole diameter (r). , It can be seen that it depends on the liquid viscosity (η), the liquid surface tension (γ) and the contact angle (θ) with the solid surface.

In Equation 1, since the contact angle (θ) and the hole diameter (r) with the solid surface are parameters dependent on the inorganic film, it has been found that the reliability of the organic EL device is improved by controlling the penetration rate by Equation 2 as the encapsulant. .

γ/2η<0.9m/s...Equation 2

As will be described later, in the organic EL device, dark spots are generated due to penetration of the encapsulant, which causes a problem of poor luminescence. By satisfying the condition of Equation 2, penetration of such an encapsulant is suppressed.

It is preferable that the viscosity of the composition of this embodiment is 8 mPa·s or more and 50 mPa·s or less measured at 25° C. and 100 rpm using an E-type viscometer. When it is difficult to eject by inkjet, the inkjet head is appropriately heated. When the viscosity is less than 8 mPa·s, the coated organic EL display element encapsulant not only flows out from the organic EL display element before curing, but also flows into the pinhole on the inorganic film to deteriorate the reliability of the OLED element. When the viscosity exceeds 50 mPa·s, application by inkjet becomes difficult. The viscosity of the composition is more preferably 8 mPa·s to 25 mPa·s.

It is preferable that the static surface tension of the composition of this embodiment is 14 mN/m or more and 40 mN/m or less. The static surface tension is measured by a plate method, a ring method, a pendant drop method, or the like, and the value of the static surface tension specified in this embodiment is by the pendant drop method. The pendant drop method refers to a method of calculating the surface tension from the shape of a suspended string (pendant drop) by pushing a liquid from the end of the tube. If the static surface tension is less than 14 mN/m, the encapsulant for the coated organic EL display element not only flows out from the organic EL display element before curing, but also flows into the pinhole on the inorganic film to deteriorate the reliability of the OLED element. When the static surface tension exceeds 40 mN/m, application by inkjet becomes difficult. The static surface tension of the composition is more preferably 20 mN/m to 30 mN/m.

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

(A) The acyclic dialkyne 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. As the component (A), α,ω-chain alkanediol di(meth)acrylate is preferred because of its low moisture permeability and large effect on ejection by inkjet and flatness after inkjet coating. More preferably, the number of carbon atoms of the main chain alkane can be 12 or less. Among α,ω-chain alkanediol di(meth)acrylates, 1,6-hexadiol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and 1,10-decanediol di(metha) )Acrylate, 1,12-dodecanediol di(meth)acrylate is preferably at least one group, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth) )Acrylate, 1,12-dodecanediol di(meth)acrylate is more preferably one or more, and 1,12-dodecanediol di(meth)acrylate is most preferred. The main chain of the component (A) may be straight chain or pulverized. Preferably, the component (A) does not have a fluorine atom, and is different from the component (E) described later.

It is preferable that content of (A) component is 10-85 mass parts with respect to 100 mass parts of (A) component and (B) component in total. When the content of (A) is 10 parts by mass or more, low moisture permeability is obtained, and when it is 85 parts by mass or less, the viscosity increases, and the reliability of the organic EL device is improved. The content of (A) is preferably 30 to 70 parts by mass, more preferably 35 to 68 parts by mass, and most preferably 45 to 65 parts by mass from the viewpoint of low moisture permeability and reliability of the organic EL device.

(B) A cyclic monomer is a monomer having a group having a cyclic structure in a molecule and having at least one unsaturated double bond group selected from the group consisting of (meth)acrylate group, (meth)acrylamide group and N-vinyl group. That is, the component (B) having a cyclic structure is different from the component (A) which is acyclic. Examples of such a cyclic structure include heterocyclic cyclic structures such as cyclic amide groups, tetrahydrofurfuryl groups, piperidinyl groups, aromatic hydrocarbon-based cyclic structures, and aliphatic hydrocarbon-based cyclic structures. Among them, at least one of the group consisting of monomers having an aromatic hydrocarbon-based cyclic structure and an aliphatic hydrocarbon-based cyclic structure is preferable from the viewpoint of ejectability and low moisture permeability by ink jet. More preferably, a cyclic (meth)acrylate monomer having an aromatic hydrocarbon-based cyclic structure and an aliphatic hydrocarbon-based cyclic structure can be used as the component (B). Preferably, the component (B) does not have a fluorine atom, and is 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 2,4,5-tetramethylphenyl ( Meth)acrylate, 4-chlorophenyl (meth)acrylate, phenoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate (2 -HPA), 2-(meth)acryloyloxyhexahydrophthalic acid, 2-(meth)acryloyloxyethyl-2-hydroxypropylphthalic acid, EO-modified phenol (meth)acrylate, EO-modified cresol (meth) In molecules such as acrylate, EO-modified nonylphenol (meth)acrylate, PO-modified nonylphenol (meth)acrylate, ethoxylated-o-phenylphenol (meth)acrylate, and m-phenoxybenzyl (meth)acrylate Monofunctional (meth)acrylate having one or more aromatic hydrocarbon-based cyclic structures, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A And bifunctional (meth)acrylates such as di(meth)acrylate and bisphenol A epoxy di(meth)acrylate. One or more of these may be used in combination. In particular, in the encapsulant for an organic electroluminescent display element according to the present embodiment, it is preferable to have two or more cyclic structures in the molecule from the viewpoint of low moisture permeability and reliability of the organic EL element. Ethoxylated-o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, ethoxylated bisphenol A di(metha) as (meth)acrylate having two or more aromatic hydrocarbon-based cyclic structures in the molecule ) One or more of the group consisting of acrylates is preferred, and one or more of the group consisting of ethoxylated-o-phenylphenol (meth)acrylate and ethoxylated bisphenol A di(meth)acrylate is more preferred.

Examples of the alicyclic hydrocarbon group in the monomer having an aliphatic hydrocarbon-based cyclic structure include groups having a dicyclopentadiene skeleton such as dicyclopentanyl group or dicyclopentenyl group, cyclohexyl group, isobornyl group, cyclodecatriene group, nord And a carbonyl group and adamantyl group. Among these, groups having a dicyclopentadiene skeleton are preferred. Examples of the (meth)acrylate having an alicyclic hydrocarbon group include cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicy And clopentenyloxyethyl (meth)acrylate, isobornyl (meth)acrylate, and methoxylated cyclodecatriene (meth)acrylate. As the (meth)acrylate having a dicyclopentadiene skeleton, tricyclodecane dimethanol di(meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyl One or more of the group consisting of oxyethyl (meth)acrylate is preferred, and one or more of the group consisting of dicyclopentanyl (meth)acrylate and tricyclodecane dimethanol di(meth)acrylate is of low moisture permeability. Is more preferred.

(B) The present inventors have found that the cyclic monomer needs to contain a mixture of a cyclic monofunctional (meth)acrylate and a cyclic bifunctional (meth)acrylate in a predetermined ratio. This is for the following reason. The cyclic monofunctional (meth)acrylate has a large effect in terms of low moisture permeability, but has a problem in that unreacted material becomes an outgas and causes poor emission of the organic EL device because of its low boiling point. Since the cyclic bifunctional (meth)acrylate has excellent low moisture permeability and low volatility, it has a great effect in terms of OLED device reliability, but has a problem of adversely affecting ink jet ejection properties because of its relatively high viscosity. The present inventors discovered that by using a cyclic monofunctional (meth)acrylate and a cyclic bifunctional (meth)acrylate in a predetermined ratio, an effect of achieving both low moisture permeability and OLED device reliability that cannot be achieved in the prior art can be obtained. The invention has been reached. That is, the content ratio of the monofunctional (meth)acrylate and the bifunctional (meth)acrylate is a monofunctional (meth)acrylate:bifunctional (meth)acrylate in a mass ratio of 100 parts by mass of the total of methacrylate and acrylate. The range of =10 to 95:90 to 5 is preferable, the range of 40 to 90:60 to 10 is more preferable, and the range of 65 to 85:35 to 15 is most preferable.

As the cyclic monofunctional (meth)acrylate, any one of the following compounds is preferable.

Cyclic monofunctional (meth)acrylate represented by the following structural formula

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

(Y in the above formula is -CH ₂ -, -(CH(R ⁵ )CH ₂ O) _m1 -, -(CH(R ⁵ )CH ₂ S) _m2 -(However, R ⁵ is a hydrogen atom or a methyl group, m1 And m2 is a number 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).

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

(B) It is preferable that at least 1 of a component has two or more cyclic structures in a molecule|numerator, and it is more preferable that at least 2 has two or more cyclic structures in a molecule|numerator.

It is preferable that content of (B) component is 15-90 mass parts with respect to 100 mass parts of total of (A) component and (B) component. When the content of (B) is 15 parts by mass or more, the viscosity increases, and the reliability of the organic EL device is improved. 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 from the viewpoint of low moisture permeability and reliability of the organic EL device.

(C) The photopolymerization initiator is used to increase or decrease the amount of light by actinic rays of visible light or ultraviolet rays to promote photocuring of the resin composition. As the photopolymerization initiator, a photoradical polymerization initiator is preferable. Examples of the photoradical polymerization initiator include benzophenone and its derivatives, benzyl and its derivatives, anthraquinone and its derivatives, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, etc. Acetophenone derivatives such as benzoin derivatives, diethoxyacetophenone, 4-tert-butyltrichloroacetophenone, 2-dimethylaminoethylbenzoate, p-dimethylaminoethylbenzoate, diphenyldisulfide, thioxanthone and Its derivative, camphorquinone, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxylic acid, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane -1-carboxy-2-bromoethyl ester, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptan-1-carboxy-2-methylester, 7,7-dimethyl-2,3 -Camphorquinone derivatives such as dioxobicyclo[2.2.1]heptan-1-carboxylic acid chloride, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2 Α-aminoalkylphenone derivatives such as benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl -Phosphine oxide, benzoyldiethoxyphosphine oxide, 2,4,6-trimethylbenzoyldimethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiethoxyphenylphosphine oxide, bis(2,4,6- Trimethylbenzoyl)-acylphosphine oxide derivatives such as phenylphosphine oxide, phenyl-glyoxylic acid-methyl ester, oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy] -Ethyl ester and oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester. The photopolymerization initiator can be used in combination of one or more. Among these, an acylphosphine oxide derivative is preferable in that it can be cured using only visible light of 390 nm or more when curing, and can be cured without damaging the organic electroluminescence display element. Among the acylphosphine oxide derivatives, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide is most preferable in that it can be cured using only 395 nm or more light without deteriorating the transmittance in visible light when used as a display. Do. Examples of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide include BASF Japan's "Irgacure TPO" and the like.

(C) The content of the photopolymerization initiator is preferably 0.05 to 6 parts by mass, more preferably 0.5 to 4 parts by mass, most preferably 2 to 3.9 parts by mass, based on 100 parts by mass of the components (A) and (B), 2.5 to 3.5 parts by mass is more preferable. When the content of the component (C) is 0.05 parts by mass or more, the curing promoting effect can be reliably obtained, and if it is 6 parts by mass or less, the transmittance in visible light does not decrease when used for a display.

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

In the composition of the present embodiment, it is preferable to contain a fluorine-containing monomer having a fluorine atom and a (meth)acryloyl group as the component (E) from the viewpoint of lowering the free energy of the surface after application and obtaining high flatness. Moreover, the (meth)acryloyl group represents an acryloyl group or a methacryloyl group. The fluorine-containing monomer may be used alone or in combination of two or more.

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 even more preferably 0.9 to 1.6 parts by mass, relative to 100 parts by mass of the components (A) and (B). If it is 0.1 parts by mass or more, flatness can be secured, and if it is 10 parts by mass or less, good inkjet coating properties can be secured.

The number of fluorine atoms in the fluorine-containing monomer as the component (E) may be 1 or more, for example, 2 or more, or preferably 3 or more. In addition, 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 relative 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 based on the total amount of the fluorine-containing monomer, preferably 70% by mass or less, and more preferably 65% by mass or less. Moreover, as content of fluorine atom with respect to the whole quantity of the composition which concerns on embodiment containing (E) component, 0.01-10 mass% is preferable, More preferably, it is good also as 0.1-5 mass %. When the content of the fluorine atom is within the above range, an effect of improving flatness can be exhibited.

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

The compound represented by the following formula (E-1) is mentioned as one specific example of a fluorine-containing monomer.

Formula (E-1)

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

The fluorinated alkyl group can be said to be a group in which some or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. The number of carbon atoms in the fluorinated alkyl group is not particularly limited, and may be, for example, 1 or more, and preferably 2 or more. Further, 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 difluoromethylene (-CF ₂ -) can be suitably used.

Specific examples of the fluorinated alkyl group include difluoromethyl group, trifluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 1,1,1-trifluoroethyl group, and 2,2,2- Trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,1,2,2-pentafluoropropyl group, 1,1,2,2,3, 3-hexafluoropropyl group, perfluoropropyl group, perfluoroethylmethyl group, 1-(trifluoromethyl)-1,2,2,2-tetrafluoroethyl group, 2,2,3,3- Tetrafluoropropyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,1, 2,2,3,3-peptafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis(trifluoro Low) methyl-2,2,2-trifluoroethyl group, 2-(perfluoropropyl)ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, 2,2 ,3,3,4,4,5,5-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl group , 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl group, 2-(perfluorobutyl)ethyl group, 1,1,1,2,2,3 ,3,4,4-nonafluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3 ,4,4,5,5,6,6-dodecafluorohexyl group, perfluorohexyl group, perfluoropentylmethyl group, and perfluorohexyl group.

A group in which an oxygen atom is inserted in a part of the carbon-carbon bond and a part of the carbon-hydrogen bond in the 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, and inserted in two or more places It may be an old flag.

Also, when an oxygen atom is inserted into the carbon-carbon bond, an ether bond is formed. In addition, when an oxygen atom is inserted into the carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of R ² may be referred to as a group containing at least one member selected from the group consisting of ether bonds and hydroxyl groups.

As a specific example of the oxygen-containing group of R ² , for example, a group represented by the following formula can be mentioned.

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

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

Formula (E-1-1)

In 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. The plural R ^21s may be the same or different from each other. However, at least one of R ²¹ is a fluorine atom.

n should just be 1 or more, Preferably it is 2 or more. In addition, the upper limit of n is not particularly limited, and may be, for example, 25 or less, or 20 or less.

R ²¹ is plural in formula (E-1-1), but at least one of them is a fluorine atom. Further, R preferably in two or more of ^{the 21} is a fluorine atom, and more preferably three or more of the fluorine atom. All of R ²¹ may 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. The ratio may be, for example, 100% or less, preferably 80% or less, and more preferably 75% or less.

It is preferable that at least one of the divalent groups (-C(R ²¹ ) ₂ -) in parentheses to which n is assigned is difluoromethylene (-CF ₂ -) in the compound represented by formula (E-1-1).

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

Formula (E-2)

In Formula (E-2), R ³ represents a hydrogen atom or a methyl group. Further, R ⁴ represents a group in which an oxygen atom is inserted in a part of a carbon-carbon bond and a carbon-hydrogen bond in a fluorinated alkanediyl group or a fluorinated alkanediyl group. The plural R ³ may be the same or different from each other.

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

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

As specific examples of the fluorinated alkanediyl group, a linear or branched fluorinated alkanediyl group having 1 to 17 carbon atoms (for example, 2,2,3,3,4,4,5,5,6,6,7,7, 8,8,9,9-hexadecafluoro-1,10-decanediyl group), a fluorinated cycloalkanediyl group having 1 to 17 carbon atoms, and the like.

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

Also, when an oxygen atom is inserted into the carbon-carbon bond, an ether bond is formed. In addition, when an oxygen atom is inserted into the carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of R ⁴ may be referred to as a group containing at least one member selected from the group consisting of ether bonds and hydroxyl groups.

As a specific example of the oxygen-containing group of R ⁴ , for example, a group represented by the following formula is mentioned.

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

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

Formula (E-2-1)

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

m should just be 1 or more, Preferably it is 2 or more, More preferably, it is 3 or more, More preferably, it is 4 or more. Moreover, the upper limit of m is not specifically limited, For example, it should just be 20 or less, Preferably it is 17 or less, More preferably, it is 15 or less.

R ⁴¹ is plural in formula (E-2-1), but at least one of them is a fluorine atom. Moreover, it is preferable that 2 or more of R ⁴¹ are fluorine atoms, and it is more preferable that 4 or more are fluorine atoms. All of R ⁴¹ may 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. The ratio may be, for example, 100% or less, preferably 95% or less, and more preferably 90% or less.

It is preferable that at least one of the divalent groups (-C(R ⁴¹ ) ₂ -) in parentheses to which m is assigned is difluoromethylene (-CF ₂ -) in the compound represented by formula (E-2-1).

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

Formula (E-3)

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

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

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

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

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

The fluorinated alkanediyl group of R ⁶ can be said to be a group in which some or all of the hydrogen atoms of the alkanediyl group described above are substituted with fluorine atoms. The number of carbon atoms in the fluorinated alkanediyl group of R ⁶ is not particularly limited, and may be, for example, 1 or more. In addition, the number of carbon atoms in the fluorinated alkanediyl group of R ⁶ may be, for example, 17 or less, preferably 15 or less, and more preferably 12 or less.

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

The group in which an oxygen atom is inserted into a part of the carbon-carbon bond and the carbon-hydrogen bond in the alkanediyl group or a fluorinated alkanediyl group (hereinafter, also referred to as an oxygen-containing group of R ⁶ ) may be a group in which an oxygen atom is inserted in one place. , It may be a group inserted in two or more places.

Also, when an oxygen atom is inserted into the carbon-carbon bond, an ether bond is formed. In addition, when an oxygen atom is inserted into the carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of R ⁶ may also be referred to as a group containing at least one member selected from the group consisting of ether bonds and hydroxyl groups.

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

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

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

Formula (E-3-1)

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, plural R ⁶¹ may be the same or different from each other. Moreover, two or more R ⁶² may mutually be same or different. However, at least one of R ⁶² is a fluorine atom.

p represents an integer of 0 or more. Here, p is 0 indicates that the benzene ring and the oxygen atom are directly bonded. p may be an integer of 1 or more. In addition, 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), all R ⁶¹ may be hydrogen atoms, all may be fluorine atoms, some may be hydrogen atoms, and the rest may be fluorine atoms. .

R ⁶² is plural in formula (E-3-1), and at least one of them is a fluorine atom. Moreover, two or more of R ⁶² may be a fluorine atom, and three or more may be a fluorine atom. Moreover, all R ⁶² (five) may be fluorine atoms.

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

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

The glass transition temperature of the cured 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, most preferably 70°C or higher and 100°C or lower in view of the reliability of the organic EL device. desirable. When the glass transition temperature of the cured body is in the range of 65°C or more and 120°C or less, when the inorganic passivation film is formed by a method such as CVD on the cured body of the composition of the present embodiment, stress is relieved so that the inorganic material film and the OLED element are difficult to peel As a result, the reliability of the organic EL device is improved.

Although the method for measuring the glass transition temperature of the cured body obtained from the composition of the present embodiment is not particularly limited, it is measured by a known method such as DSC or dynamic viscoelastic spectrum, and preferably a dynamic viscoelastic spectrum is used. In the dynamic viscoelastic spectrum, the temperature at which the peak of the loss tangent (hereinafter referred to as tanδ) is peaked by applying stress and strain to the cured body at a constant heating rate can be set as the glass transition temperature. If the peak of tanδ does not appear even when the temperature is raised from a sufficiently low temperature of about -150°C to a temperature (Ta°C), the glass transition temperature is considered to be -150°C or lower, or higher than any temperature (Ta°C). Since the composition below -150°C is unthinkable due to its structure, it can be set to a certain temperature (Ta°C) or higher.

The composition of the present embodiment may use (D) an antioxidant to improve storage stability. As antioxidants, methylhydroquinone, hydroquinone, 3-[3,5-di-tert-butyl-4-hydroxyphenyl]octadecyl propionate, 2,2-methylene-bis(4-methyl-6-tert-butyl Phenol), catechol, hydroquinone monomethyl ether, monotert-butylhydroquinone, 2,5-ditert-butylhydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, 2,5 -Ditert-butyl-p-benzoquinone, picric acid, citric acid, phenothiazine, tert-butylcatechol, 2-butyl-4-hydroxyanisole and 2,6-ditert-butyl-p-cresol Can be lifted. It is preferable to combine two or more antioxidants. Among these, a phenolic antioxidant is preferred because of its large effect such as transparency and storage stability. Among the phenolic antioxidants, hindered phenolic antioxidants are preferred. As a hindered phenolic antioxidant, 3-[3,5-di-tert-butyl-4-hydroxyphenyl]octadecyl propionate, 2,2-methylene-bis(4-methyl-6-tert-butylphenol) One or more of the group consisting of preferably, 3-[3,5-di-tert-butyl-4-hydroxyphenyl]octadecyl propionate and 2,2-methylene-bis(4-methyl-6-tert-butyl Phenol) is more preferred. Examples of 3-[3,5-di-tert-butyl-4-hydroxyphenyl]octadecyl propionate include BASF Japan Corporation "Irganox 1076" and the like. As 2,2-methylene-bis (4-methyl-6-tert-butylphenol), Sumitomo Chemical Co., Ltd. product "SUMILIZER MDP-S" etc. are mentioned. 3-[3,5-di-tert-butyl-4-hydroxyphenyl]octadecyl propionate and 2,2-methylene-bis(4-methyl-6-tert-butylphenol), 3-[ The content ratio of 3,5-di-tert-butyl-4-hydroxyphenyl]octadecyl propionate and 2,2-methylene-bis(4-methyl-6-tert-butylphenol) is 3-[3,5- Di-tert-butyl-4-hydroxyphenyl]octadecyl propionate and 2,2-methylene-bis(4-methyl-6-tert-butylphenol) in a mass ratio of 100 parts by mass in 3-[3,5- Di-tert-butyl-4-hydroxyphenyl]octadecyl propionate:2,2-methylene-bis(4-methyl-6-tert-butylphenol)=10 to 90:90 to 10 is preferred, and 25 to 75 :75 to 25 are more preferable.

The content of the antioxidant is preferably 0.001 to 3 parts by mass, more preferably 0.01 to 2 parts by mass, relative to 100 parts by mass of the components (A) and (B) in total. If it is 0.001 part by mass or more, storage stability is secured, and if it is 3 parts by mass or less, good adhesiveness can be obtained and there is no uncuring.

The composition according to the present embodiment may further contain additives used in the art, for example, antioxidants, metal deactivators, fillers, stabilizers, neutralizing agents, lubricants, antibacterial agents, and the like.

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

As a method of curing the composition by irradiating with visible light or ultraviolet light, a method of curing the composition by irradiating at least one of visible light or ultraviolet light may be mentioned. As an energy source for irradiating such visible light or ultraviolet light, a deuterium lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, a low pressure mercury lamp, a xenon lamp, a xenon-mercury hybrid lamp, a halogen lamp, an excimer lamp, an indium lamp, a thallium lamp, an LED lamp And an energy irradiation source such as an electrodeless discharge lamp. Since the composition of the present embodiment is hard to damage the organic EL device, it is preferable to cure at a wavelength of 380 nm or more, more preferably at a wavelength of 395 nm or more, and most preferably at a wavelength of 395 nm. The wavelength of the energy irradiating source is preferably 500 nm or less because the temperature of the irradiating portion may rise and damage the organic EL device by emitting infrared light. As the energy irradiation source, an LED lamp having a short wavelength is preferable.

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

Transparency of the composition of the present embodiment, when the thickness of the organic material film is 1 μm or more and 10 μm or less, the spectral transmittance of the ultraviolet-visible light region of 360 nm or more and 800 nm or less is preferably 95% or more, more preferably 97% or more, and 99% or more Most preferred. If it is 95% or more, an organic EL device excellent in luminance and contrast can be provided.

It is preferable that the sealing layer which consists of the composition of this embodiment is an inorganic/organic laminated body as 1 set, and is 1-5 sets of washing faces. This is because when the inorganic/organic laminate is 6 or more sets, the sealing effect for the organic EL element is almost the same as in the case of 5 sets. The inorganic/organic laminate preferably has a thickness of 50 nm to 1 μm. The thickness of the organic material film of the inorganic/organic laminate is preferably 1 to 15 μm, and more preferably 3 to 10 μm. When the thickness of the organic material film is less than 1 μm, particles generated at the time of device formation may not be completely covered, and thus it may be difficult to coat the inorganic material film with good flatness. When the thickness of the organic material film exceeds 15 μm, moisture may intrude from the side surface of the organic material film, and the reliability of the organic EL device may be lowered.

The encapsulation substrate is formed in close contact with the entire upper surface of the topmost organic material film of the encapsulation layer. The above-mentioned substrate is mentioned as this sealing substrate. Among them, a substrate transparent to visible light is preferable. Among the substrates transparent to visible light (transparent encapsulation substrates), at least one of the group consisting of a glass substrate and a plastic substrate is preferable, and a glass substrate is more preferable.

The thickness of the transparent encapsulation 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 encapsulation substrate on the upper layer of the encapsulation layer, deterioration that proceeds when the surface of the uppermost organic film is in contact with the gas can be suppressed and the barrier property of the organic EL device can be improved.

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

Next, a first inorganic film having a predetermined thickness is formed on a substrate on which an organic EL device is formed, according to a film deposition method such as a physical vapor deposition (PVD) method such as sputtering or a CVD method such as a plasma CVD (Chemical Vapor Deposition) method. do. Thereafter, the composition of the present embodiment is adhered onto the first inorganic film by using a coating film forming method such as a solution coating method or a spray coating method, a flash deposition method, an inkjet method or the like. Among these, the inkjet method is preferable from the viewpoint of productivity. Thereafter, the composition is cured by irradiation of energy rays such as ultraviolet rays, electron beams, or plasma to form a first organic film. Through the above process, one set of inorganic/organic laminates is formed. The curing rate of the composition is not particularly limited as long as the effect of the present embodiment is exhibited, but can be, for example, 90% or more, preferably 95% or more, as a value obtained according to a measurement method described later.

The process of forming the inorganic/organic laminate shown above is repeated a predetermined number of times. However, for the last set, that is, the inorganic/organic laminate of the uppermost layer, the composition may be attached to the upper surface of the inorganic material film by a coating method, a flash deposition method, an inkjet method or the like so that the upper surface is flattened.

Next, the transparent encapsulation substrate is glued to the surface to which the composition on the substrate is attached. When aligning, the alignment is performed. Thereafter, by irradiating energy rays from the side of the transparent encapsulation substrate, the composition of the present embodiment existing between the inorganic film of the uppermost layer and the transparent encapsulation substrate is cured. Accordingly, the composition is cured to form a top organic film and a top organic film and a transparent encapsulation substrate are adhered. The manufacturing method of the organic EL device is completed.

After attaching the composition on the inorganic film, it may be polymerized by partially irradiating energy rays. By doing in this way, the shape collapse of the composition which becomes the uppermost organic film when the transparent sealing substrate is placed can be prevented. The thickness of the inorganic film and the organic film may be the same for each inorganic/organic laminate, or may be different for each inorganic/organic laminate.

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

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

According to the present embodiment, since an encapsulation layer for blocking the organic EL element formed on the first substrate and blocking the outside air is formed, and further, a transparent encapsulation substrate is disposed on the encapsulation layer, sufficient water vapor and oxygen for the organic EL element are provided. A sealing structure having barrier properties can be obtained. According to this embodiment, a sealing structure having sufficient adhesive strength between the transparent sealing substrate and the sealing layer can be obtained.

According to the present embodiment, after attaching the composition of the present embodiment constituting the topmost organic film of the encapsulation layer, the transparent encapsulation substrate is placed without curing the composition, and then the composition is cured. Simultaneously with formation, adhesion between the sealing layer and the transparent sealing substrate can be performed. As a result, this embodiment has an effect that the process can be simplified compared to the case where the sealing layer and the transparent sealing substrate are adhered with an adhesive.

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

According to this embodiment, it is possible to provide an encapsulant for an organic EL display element that can be easily coated by an inkjet method and has excellent reliability of an OLED element, transparency of a cured body, and barrier property. According to this embodiment, the manufacturing method of the organic electroluminescent display element using the sealing agent for organic electroluminescent display elements can be provided. The inkjet method refers to a method of discharging a fine droplet from a nozzle and applying the object non-contactly.

Example

(Experimental Examples 1-8)

The composition was prepared and evaluated by the following method.

(Production of composition)

The materials used in Table 1 were used. The composition was prepared by mixing each used material with the composition shown in Tables 2-3. Using the obtained composition, E-type viscosity, surface tension, moisture permeability, magnification of coating area, curing rate, flatness, transparency, glass transition temperature, and organic EL evaluation were measured by the evaluation methods shown below. The results are shown in Tables 2-3. The symbol shown in Table 1 was used for the composition name of Table 2-3. The fluorine atom content shown in Tables 2 to 3 is calculated from the composition and is expressed based on the total amount of the composition.

(Type E viscosity (η))

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

[Surface tension (γ)]

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

〔Light curing conditions〕

Upon evaluation of the curing properties of the composition, the composition was cured under the following light irradiation conditions. A cured body was obtained by photocuring the composition under conditions of an accumulated light amount of 1,500 mJ/cm 2 at a wavelength of 395 nm by an LED lamp emitting UV at a wavelength of 395 nm (UV-LED LIGHT SOURCE H-4MLH200-V1 manufactured by HOYA).

〔Water permeability〕

A sheet-shaped cured product having a thickness of 0.1 mm was produced under the above-mentioned photocuring conditions, and in accordance with JIS Z0208:1976 "Testing method for moisture permeability of moisture-proof packaging materials (cup method)", using calcium chloride (anhydrous) as an absorbent, the ambient temperature was 85 deg. It was measured under conditions of 85% humidity.

(Curing rate)

The composition obtained in each experimental example was coated with a size of 10 mm×10 mm on an alkali-free glass cleaned by the above-described method so as to have a thickness of 10 μm using the inkjet device, and in a nitrogen atmosphere having an oxygen concentration of less than 0.1%. It cured under the said photocuring conditions, and the curing rate was measured in the following order.

Infrared light was incident on the measurement sample using an infrared spectroscopy device (Thermo Scientific, Nicolet is5, DTGS detector, resolution 4 cm ^{- 1} ) to the composition after curing and the composition before curing to measure infrared spectral spectrum. In the obtained infrared spectral spectrum, the elastic vibration peak of the carbon-hydrogen bond of the methylene group observed around 2950 cm ^-1 which does not cause peak changes before and after curing is taken as an internal standard, and the peak area before and after curing of this internal standard is ) The curing rate was calculated by using the following formula from the area before and after curing of the peak around 810 cm ^-1 which is attributed to the peak of the out-of-plane angular vibration of the carbon-hydrogen bond bound to the carbon-carbon double bond of the acrylate.

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

here,

Ao: It represents the peak area before hardening in the vicinity of 810 cm ^-1 .

Ax: shows the peak area after hardening in the vicinity of 810 cm ^-1 .

Bo: It shows the peak area before hardening in the vicinity of 2950 cm ^-1 .

Bx: It represents the peak area after hardening of around 2950 cm ^-1 .

〔Transparency〕

The composition obtained in each Experimental Example was formed to a thickness of 10 μm between two 25 mm×25 mm×1 mmt (mm thick) glass plates (alkali-free glass, Eagle XG manufactured by Corning), and using a LED lamp, ultraviolet light having a wavelength of 395 nm was used. It cured by irradiating so that the irradiation amount may become 1500 mJ/cm<2>, and hardened|cured material was obtained. The obtained cured product was measured for 380 nm, 412 nm, and 800 nm spectral transmittance with an ultraviolet-visible spectrophotometer ("UV-2550" manufactured by Shimadzu Corporation) to obtain transparency.

(Glass transition temperature)

The composition obtained in each experimental example was sandwiched with a 1 mm thick silicone sheet into a PET film. This composition was cured from the top surface under the above photocuring conditions, and further cured under the above photocuring conditions from below to prepare a cured body of the composition having a thickness of 1 mm. The produced cured body was cut into a length of 50 mm and a width of 5 mm with a cutter to obtain a cured body for measuring the glass transition temperature. The obtained hardened body was subjected to a stress and strain in the tensile direction of 1 Hz to the hardened body in a nitrogen atmosphere by a dynamic viscoelasticity measuring device "DMS210" manufactured by Seiko Electronics Industries Co., Ltd., while increasing the temperature from -150 to 200 °C at a rate of 2 °C/min. Was measured, and the temperature of this tanδ peak top was taken as the glass transition temperature. The peak of tanδ was set to the maximum in the region where tanδ is 0.3 or more. When tanδ is 0.3 or less in the region of -150°C to 200°C, the peak of tanδ is said to exceed 200°C, and the glass transition temperature is said to exceed 200°C (200<).

〔Enlargement rate of coated area〕

Inkjet ejection device (MID500B manufactured by Musashi Engineering Corporation, solvent-based head "MID head") was used on the composition obtained in each experimental example on a base material of 70 mm x 70 mm x 0.7 mmt (alkali-free glass (Eagle XG manufactured by Corning)). Then, the pattern was applied so as to be 4 mm×4 mm×10 μmt. The alkali-free glass was washed with acetone and isopropanol before use, and then cleaned for 5 minutes using a UV-208 UV ozone cleaning device manufactured by Techno Vision. Immediately after the pattern was applied, it was left for 5 minutes under the conditions of an atmospheric temperature of 23°C and a relative humidity of 50%, and the flatness after the inkjet application was evaluated by the magnification of the application area (see the formula below). It was evaluated that the smaller the enlargement ratio of the application area, the better the shape after application and position controllability.

(Expansion rate of application area) = ((Contact area of the composition contacting the surface of the base material 5 minutes after pattern application)/(Contact area of the composition contacting the surface of the base material immediately after pattern application))×100 (%)

[Flatness]

On the 70 mm × 70 mm × 0.7 mmt base material (alkali-free glass (Eagle XG, manufactured by Corning)), 25 μm×25 μm×3 μmt recesses were prepared by etching to align the gaps at 10 μm front to back, left, and right. Further, the base material was cleaned with acetone and isopropanol before use, and then cleaned for 5 minutes using a UV-208 UV ozone cleaning device manufactured by Techno Vision. Next, a 200 nm SiN film was formed on the substrate provided with the recess by plasma CVD. Next, using an inkjet ejecting device (MID500B manufactured by Musashi Engineering Co., Ltd., a solvent-based head "MID head"), a sealing agent was pattern-coated to be 50 mm x 50 mm x 10 μmt. After the pattern was applied, it was left for 5 minutes under conditions of a temperature of 23°C and a relative humidity of 50%, and the shape of the encapsulant coating film was observed. The flatness of the encapsulant was determined by the following equation. Table 1 shows the results.

Flatness (%)=(area of encapsulant coating film after 5 minutes of standing)/(50mm×50mm)

In addition, for example, 50% flatness indicates that a part of the encapsulating agent coated with the pattern is separated and the SiN film is exposed in half (50%) of the range of 50 mm×50 mm.

(Organic EL evaluation)

(Production of Organic EL Device Substrate)

A glass substrate (700 μm thick) with an ITO electrode of 30 mm in width was cleaned using acetone and isopropanol, respectively. Subsequently, the following compounds were sequentially deposited to be thin films by a vacuum deposition method to obtain a substrate having an organic EL device having a width of 2 mm composed of an anode/hole injection layer/hole transport layer/light emitting layer/electron injection layer/cathode. The composition of each layer is as follows.

·anode ITO, anode film thickness 150nm

·Hole injection layer 4,4',4"-tris{2-naphthyl(phenyl)amino}triphenylamine (2-TNATA)

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

·Light emitting layer Tris (8-hydroxyquinolinato) aluminum (metal complex system material), the film thickness of the light-emitting layer is 1000 mm 2, and the light-emitting layer also functions as an electron transport layer.

·Electronic injection layer Lithium fluoride

·cathode Aluminum, film thickness 150nm

(Production of organic EL elements)

Thereafter, a mask (cover) having an opening of 10 mm x 10 mm was formed so as to cover the organic EL element of 2 mm x 2 mm, and a SiN film was formed by plasma CVD. Next, the composition (organic film) obtained in each experimental example was coated with a thickness of 10 μm to cover a 2 mm×2 mm organic EL element using the inkjet apparatus under a nitrogen atmosphere, and the composition was cured under the photocuring conditions. A mask (cover) having an opening of 10 mm x 10 mm was provided to cover the entire cured body, and a SiN film was formed by plasma CVD to obtain an organic EL display device.

The formed SiN (inorganic film) had a thickness of about 1 μm. Subsequently, an organic EL device was fabricated by bonding with 30 mm x 30 mm x 0.7 mmt non-alkali glass (Eagle XG manufactured by Corning) using a double-sided tape without a transparent base material of 30 mm x 30 mm x 25 μmt (Organic EL evaluation).

〔Early〕

A voltage of 6 V was applied to the organic EL device immediately after fabrication, and the light emission state of the organic EL device was observed with the naked eye and a microscope to measure the diameter of the dark spot.

〔durability〕

The organic EL device immediately after the fabrication was exposed to 85°C and a relative humidity of 85 mass% for 70 hours, and then a voltage of 6 V was applied, and the light emission state of the organic EL device was observed with a naked eye and a microscope to measure the diameter of the dark spot. Did.

The diameter of the dark spot can be grasped as an index for evaluating the degree of penetration of the encapsulant into the pinholes of the passivation layer and the degree of moisture in the encapsulant discharged as outgas. It was evaluated that the diameter of the dark spot is preferably 300 μm or less, more preferably 50 μm or less, and most preferably, the absence of a dark spot.

The following can be seen from the above experimental example.

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

As (A), an alkanediol dimethacrylate having 6 or more carbon atoms is used, and (B) a cyclic monofunctional (meth)acrylate and a cyclic bifunctional (meth)acrylate, and the formulas (I) to (III) are used. When all were satisfied, the reliability, inkjet ejection property, shape retention property, and low moisture permeability were excellent (Experimental Examples 1 to 3, 10 to 11).

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

On the other hand, when (A) an alkanediol di(meth)acrylate having less than 6 carbon atoms was used, the magnification of the coating area was large, so that the shape after inkjet coating could not be maintained, that is, there was a problem in shape retention (Experimental Example) 12). When the content of the component (A) was more than 85 parts by mass and the content of the component (B) was less than 15 parts by mass, the viscosity was low and the shape retention and reliability were not obtained except that the formula (III) was not satisfied (Experimental Example 13) ). In the case of using a long-chain alkyl monofunctional acrylate and a cyclic bifunctional methacrylate without using a cyclic monofunctional (meth)acrylate as (B), the viscosity is low and the formula (III) cannot be satisfied. The moisture permeability was not obtained (Experimental Example 14). As (A), an alkanediol dimethacrylate having an acyclic carbon number of 6 or more and (B) using two cyclic (meth)acrylates, satisfying the formulas (II) to (III), and also exceeding a viscosity of 50 mPa·s In the case of low moisture permeability, it was impossible to evaluate the reliability and shape retention because ink jet ejection was impossible (Experimental Example 15). When (B) does not use a cyclic bifunctional (meth)acrylate and uses only a cyclic monofunctional acrylate, and also satisfies the formulas (I) to (III), transparency and shape retention are poor (Experimental Example 16). .

The composition of the present embodiment is excellent in ejection by high-precision inkjet and flatness after inkjet coating, has low moisture permeability and transparency, and does not degrade the organic EL device. This embodiment can apply inkjet in a short time. The composition of the present embodiment is an electronic product, in particular, a display component such as an organic EL (for example, a flexible display or organic EL device used in wearable products, etc.), an electronic component such as an image sensor such as CCD or CMOS, and further a semiconductor. It can be suitably applied in the adhesion of device packages used in parts and the like. In particular, it is optimal for adhesion for an organic EL encapsulation, and satisfies the characteristics required for an adhesive for an element package such as an organic EL element or a coating agent for an element package.

The said composition is one aspect of this embodiment, and the sealing agent for organic EL elements of this embodiment, hardened|cured material, organic EL device, display, these manufacturing methods, etc. have the same structure and effect.

Claims (29)

(A) containing an acyclic dialkyne di(meth)acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator.
(B) The cyclic monomer contains a cyclic monofunctional (meth)acrylate and a cyclic bifunctional (meth)acrylate,
An encapsulant for an organic electroluminescence display device satisfying both of the following formulas (I) and (III).
8mPa·s≤η≤50mPa·s···(I)
γ/2η<0.9m/s...(III)
(Wherein, η represents the viscosity measured by an E-type viscometer at 25°C, and γ represents the static surface tension measured by the pendant drop method.) (A) containing an acyclic dialkyne di(meth)acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator.
(A) 10-85 parts by mass of the component (A) and 15-90 parts by mass of the component (B) with respect to 100 parts by mass of the component (A) and (B),
(B) The cyclic monomer contains a cyclic monofunctional (meth)acrylate and a cyclic bifunctional (meth)acrylate,
The content ratio of the cyclic monofunctional (meth)acrylate and the cyclic bifunctional (meth)acrylate is a cyclic monofunctional (mass ratio) in a mass ratio of 100 parts by mass of the total of the cyclic monofunctional (meth)acrylate and the cyclic bifunctional (meth)acrylate ( Meth)acrylate: cyclic bifunctional (meth)acrylate = 10 to 95: 90 to 5, and
An encapsulant for an organic electroluminescence display device satisfying all of the following formulas (I), (II) and (III).
8mPa·s≤η≤50mPa·s···(I)
14mN/m≤γ≤40mN/m...(II)
γ/2η<0.9m/s...(III)
(Wherein, η represents the viscosity measured by an E-type viscometer at 25°C, and γ represents the static surface tension measured by the pendant drop method.) The method according to claim 1 or claim 2,
(B) An encapsulant for an organic electroluminescence display device, wherein the cyclic monomer contains at least one alicyclic monomer. The method according to any one of claims 1 to 3,
(E) Encapsulation agent for organic electroluminescence display elements containing a fluorine-containing monomer having a fluorine atom and a (meth)acryloyl group as a component. The method according to claim 4,
An encapsulant for an organic electroluminescence display element 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 method according to claim 4 or claim 5,
The organic electroluminescence in which the fluorine-containing monomer comprises at least one member selected from the group consisting of a compound represented by formula (E-1), a compound represented by formula (E-2), and a compound represented by formula (E-3). Sealing agent for sense display elements.
Formula (E-1)
[Formula 1]

[In formula (E-1),
R ¹ represents a hydrogen atom or a methyl group,
R ² represents a group in which an oxygen atom is inserted in a part of a carbon-carbon bond and a carbon-hydrogen bond in a fluorinated alkyl group or a fluorinated alkyl group.]
Formula (E-2)
[Formula 2]

[In formula (E-2),
R ³ represents a hydrogen atom or a methyl group,
R ⁴ represents a group in which an oxygen atom is inserted in a part of a carbon-carbon bond and a carbon-hydrogen bond in a fluorinated alkanediyl group or a fluorinated alkanediyl group. The plural R ³ may be the same or different from each other.]
Formula (E-3)
[Formula 3]

[In formula (E-3),
R ⁵ represents a hydrogen atom or a methyl group,
R ⁶ represents a single bond, an alkanediyl group, an alkanediyl fluoride group, or an alkanediyl group or a group in which an oxygen atom is inserted in a part of the carbon-carbon bond and the carbon-hydrogen bond in the alkanediyl group,
Ar ¹ represents a fluorinated aryl group.] The method according to claim 6,
The fluorine-containing monomer is at least one member selected from the group consisting of compounds represented by formula (E-1-1), compounds represented by formula (E-2-1) and compounds represented by formula (E-3-1) Encapsulation agent for an organic electroluminescent display element containing.
Formula (E-1-1)
[Formula 4]

[In 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. The plural R ^21s may be the same or different from each other. Provided that at least one of R ²¹ is a fluorine atom.]
Formula (E-2-1)
[Formula 5]

[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. The plural R ⁴¹ may be the same or different from each other. The plural R ³ may be the same or different from each other. Provided that at least one of R ⁴¹ is a fluorine atom.]
Formula (E-3-1)
[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, and p represents an integer of 0 or more . The plural R ⁶¹ may be the same or different from each other. The plural R ^62s may be the same or different from each other. Provided that at least one of R ⁶² is a fluorine atom.] The method according to any one of claims 4 to 7,
(E) The organic electroluminescent display element sealing agent characterized in that the content of the component is in the range of 0.1 parts by mass to 10 parts by mass with respect to 100 parts by mass of the components (A) and (B). The method according to any one of claims 4 to 8,
(E) The component is 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluoro-1,10-decanediol di( Meta)acrylate, 1H,1H,5H-octafluoropentyl (meth)acrylate and 1H,1H,2H,2H-tridecafluorooctyl (meth)acrylate. A sealing agent for an organic electroluminescent display device, characterized in that. The method according to any one of claims 1 to 9,
An encapsulant for an organic electroluminescent display device, characterized in that it is applied using an inkjet method. The method according to any one of claims 1 to 10,
Organic electroluminescence display device characterized by not containing a bifunctional (meth)acrylate oligomer, bifunctional (meth)acrylate polymer, polyfunctional (meth)acrylate oligomer or polyfunctional (meth)acrylate polymer Dragon sealant. The method according to any one of claims 1 to 11,
An encapsulant for an organic electroluminescence display device, characterized in that the glass transition temperature of the cured body is 65°C or higher and 120°C or lower. The method according to any one of claims 1 to 12,
(B) At least one of the components has an organic electroluminescent display element sealing agent, characterized in that it has two or more cyclic structures in the molecule. The method according to any one of claims 1 to 13,
(B) At least two of the components have two or more cyclic structures in the molecule. The encapsulant for organic electroluminescence display elements. The method according to any one of claims 1 to 14,
(B) Ethoxylated-o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ethoxylated bisphenol A represented by the following structural formula An encapsulant for an organic electroluminescent display device comprising at least one of the group consisting of di(meth)acrylate.
[Formula 7]

(R in the formula is each independently a hydrogen atom or a methyl group. m + n = 2 to 10 with respect to m and n in the formula) The method according to any one of claims 1 to 15,
(A) The organic electroluminescent display element sealing agent characterized in that the component is an alkanediol di(meth)acrylate having 12 or less carbon atoms. The method according to any one of claims 1 to 16,
(A) component is 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate An encapsulant for an organic electroluminescent display device comprising the above. The method according to any one of claims 1 to 17,
(C) The organic electroluminescent display element sealing agent characterized in that the component contains 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. The method according to any one of claims 1 to 18,
(C) An organic electroluminescent display element sealing agent characterized in that the content of the component is 0.5 to 4 parts by mass. The method according to any one of claims 1 to 19,
(D) An encapsulant for an organic electroluminescent display device, further comprising an antioxidant. The method according to claim 20,
(D) An encapsulant for an organic electroluminescent display device, characterized in that the component is a hindered phenol-based antioxidant. The method according to claim 20 or claim 21,
(D) An encapsulant for an organic electroluminescent display device comprising two or more components. The method according to any one of claims 1 to 22,
An encapsulant for an organic electroluminescence display device, which is cured at a wavelength of 395 nm or more and 500 nm or less. The method according to claim 23,
An encapsulant for an organic electroluminescent display device, characterized by curing with a 395nm LED lamp. Hardened|cured material formed by hardening the sealing agent for organic electroluminescence display elements in any one of Claims 1-24. An organic EL device comprising the cured product according to claim 25. A display comprising the cured product according to claim 25. A flexible display comprising the cured product according to claim 25. An organic EL device having flexibility, comprising the cured product according to claim 25.