KR102626849B1 - Encapsulant for organic electroluminescence display elements - Google Patents

Abstract

It contains (A) an acyclic alkanediol di(meth)acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator, and (B) the cyclic monomer is a cyclic monofunctional (meth)acrylate. An encapsulant for an organic electroluminescence display device containing cyclic difunctional (meth)acrylate and satisfying both formulas (I) and (III) below. 8mPa·s≤η≤50mPa···(I) γ/2η<0.9m/s···(III) (In the formula, 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.)

Description

Encapsulant for organic electroluminescence display elements

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

Organic electroluminescence (EL) devices (also known as OLED devices) are attracting attention as devices capable of emitting light with high brightness. However, OLED devices have the problem that they deteriorate due to moisture and their luminous properties deteriorate.

To solve these problems, technologies for encapsulating organic EL devices to prevent deterioration due to moisture are being investigated. For example, there is a method of sealing with a sealant made of frit glass (see Patent Document 1).

An organic electroluminescence display device (see Patent Document 2), characterized in that the encapsulation layer is a laminate in which at least a barrier layer, a resin layer, and a barrier layer are formed sequentially, and an inorganic film and an organic film alternately encapsulate the organic EL device. An organic EL device (see Patent Document 3) has been proposed, comprising a stacked encapsulation layer and an encapsulation glass substrate that is placed in close contact with the uppermost organic film of the encapsulation layer and covers the entire upper surface of the uppermost organic film. there is.

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

Patent Document 1: Japanese Patent Laid-Open No. 10-74583 Patent Document 2: Japanese 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 No. WO2014/157642 Patent Document 11: Publication No. US2017/0062762

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

In Patent Document 1, when performing mass production, a method of embedding the organic EL element in a base material with low moisture permeability, such as glass, and sealing the outer peripheral portion is adopted. In this case, since this structure is a hollow encapsulation structure, it is not possible to prevent moisture from entering the hollow encapsulation structure, leading to deterioration of the organic EL device.

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

Patent Document 4 proposes an encapsulant using an epoxy-based material, but since this material requires heating to cure, it damages the organic EL device and poses a problem in terms of yield. Patent Document 5 proposes a photocurable encapsulant using an epoxy-based material, but since this material is cured by UV light, the organic EL device is damaged by UV light, which poses a problem in terms of yield.

In Patent Documents 6 to 10, there is a description of reducing the water vapor permeability as a characteristic required for such an encapsulating material, but the problem of the encapsulating material itself penetrating through pinholes in the passivation film and lowering the reliability of the organic EL device and its countermeasures are discussed. There is no description.

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

In this way, in the above-described prior art, the inability to coexist between the discharge performance when using inkjet and the reliability of the organic EL element has always been a problem.

The present invention has been made in consideration of the above circumstances, and its purpose is to provide a composition that is excellent in both ejection properties when using inkjet and reliability of organic EL devices when used, for example, for encapsulating organic EL devices.

The present invention can provide the following.

<1> Contains (A) 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 cyclic monofunctional (meth)acrylate and cyclic difunctional (meth)acrylate,

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

8mPa·s≤η≤50mPa·s···(I)

γ/2η<0.9m/s···(III)

(In the formula, 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> Contains (A) an acyclic alkanediol di(meth)acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator,

Containing 10 to 85 parts by mass of component (A) and 15 to 90 parts by mass of component (B), based on a total of 100 parts by mass of component (A) and component (B),

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

The content ratio of cyclic monofunctional (meth)acrylate and cyclic difunctional (meth)acrylate is the mass ratio of cyclic monofunctional (meth)acrylate ( Meth)acrylate: Cyclic bifunctional (meth)acrylate = 10~95:90~5, and

An encapsulant for an organic electroluminescence display device that satisfies 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)

(In the formula, 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> (B) The encapsulant for an organic electroluminescence display element according to <1> or <2>, wherein the cyclic monomer contains one or more types of alicyclic monomer.

<4> (E) The encapsulant for an organic electroluminescent display element 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.

<5> The encapsulant for an organic electroluminescent display element 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 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 encapsulant for an organic electroluminescent display element according to <4> or <5>.

Equation (E-1)

[In formula (E-1),

R ¹ represents a hydrogen atom or a methyl group,

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

Equation (E-2)

[In equation (E-2),

R ³ represents a hydrogen atom or a methyl group,

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

Equation (E-3)

[In equation (E-3),

R ⁵ represents a hydrogen atom or a methyl group,

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

Ar ¹ represents an aryl fluoride 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 encapsulant for an organic electroluminescence display element according to <6>, comprising one type.

Equation (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. A plurality of R ²¹ may be the same or different from each other. However, at least one of R ²¹ is a fluorine atom.]

Equation (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. A plurality of R ⁴¹ may be the same or different from each other. However, at least one of R ⁴¹ is a fluorine atom. Multiple R ³ may be the same or different from each other.]

Equation (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. . A plurality of R ⁶¹ may be the same or different from each other. A plurality of R ⁶² may be the same or different from each other. However, at least one of R ⁶² is a fluorine atom.]

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

<9> (E) The component is 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluoro-1,10-decane. A type selected from the group consisting of diol di(meth)acrylate, 1H,1H,5H-octafluoropentyl(meth)acrylate, and 1H,1H,2H,2H-tridecafluorooctyl(meth)acrylate The encapsulant for an organic electroluminescence display element according to any one of <4> to <8>, comprising the above.

<10> The encapsulant for an organic electroluminescent display element according to any one of <1> to <9>, characterized in that it is applied using an inkjet method.

<11> <1>, characterized in that it does not contain bifunctional (meth)acrylate oligomers, bifunctional (meth)acrylate polymers, polyfunctional (meth)acrylate oligomers or polyfunctional (meth)acrylate polymers. The encapsulant for an organic electroluminescence display element according to any one of to <10>.

<12> The encapsulant for an organic electroluminescence display element according to any one of <1> to <11>, wherein the glass transition temperature of the cured body is 65°C or higher and 120°C or lower.

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

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

<15> (B) The component is ethoxylated-o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, and ethoxylated with the following structural formula: The encapsulant for an organic electroluminescence display element according to any one of <1> to <14>, comprising at least one member of the group consisting of oxidized bisphenol A di(meth)acrylate.

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

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

<17> (A) A group in which the component consists of 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and 1,12-dodecanediol di(meth)acrylate. The encapsulant for an organic electroluminescence display element according to any one of <1> to <16>, comprising at least one of the following.

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

<19> The encapsulant for an organic electroluminescent display element 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) The encapsulant for an organic electroluminescence display element according to any one of <1> to <19>, which further contains an antioxidant.

<21> The encapsulant for an organic electroluminescence display element according to <20>, wherein the component (D) is a hindered phenol-based antioxidant.

<22> The encapsulant for an organic electroluminescent display element according to <20> or <21>, which contains two or more types of (D) components.

<23> The encapsulant for an organic electroluminescent display element 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 encapsulant for an organic electroluminescence display element according to <23>, characterized in that it is cured with a 395 nm LED lamp.

<25> A cured body obtained by curing the encapsulant for organic electroluminescence display elements according to any one of <1> to <24>.

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

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

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

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

The encapsulant according to the present invention has excellent ejection properties when using inkjet, and has the effect of being excellent in the reliability of the resulting organic EL device.

Hereinafter, this embodiment will be described. Numerical ranges described in this specification include upper and lower limits unless otherwise specified. In this specification, unless otherwise specified, it is defined below. (meth)acrylate refers to acrylate or methacrylate, and notations such as “(meth)acryloyloxy” or “(meth)acrylamide” have 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 does not include difunctional (meth)acrylate.

Hereinafter, a top emission type organic EL device that emits light from the side opposite to the substrate of the organic EL element formed on the substrate will be described as an example. A top emission type organic EL device includes an organic EL element in which an organic EL layer including an anode and a light emitting layer and a cathode are sequentially laminated on a substrate, and an encapsulation layer consisting of a lamination of an inorganic film and an organic film that covers the entire organic EL element. It has a structure in which an encapsulation substrate installed on the encapsulation layer is formed sequentially.

Various substrates such as glass substrates, silicon substrates, and plastic substrates can be used. Among these, at least one type from the group consisting of a glass substrate and a plastic substrate is preferable, and a glass substrate is more preferable.

Plastics used in plastic substrates include polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, polyoxadiazole, aromatic polyamide, polybenzoimidazole, polybenzobisthiazole, polybenzoxazole, polythiazole, Examples include polyparaphenylene vinylene, polymethyl methacrylate, polystyrene, polycarbonate, polycycloolefin, and polyacrylic. Among these, polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, polyoxadiazole, aromatic polyamide, polybenzoimidazole, polybenzobisthiazole, and polyimide are excellent in terms of low moisture permeability, low oxygen permeability, and heat resistance. At least one member of the group consisting of benzoxazole, polythiazole, and polyparaphenylenevinylene is preferred, and polyimide, polyetherimide, polyethylene terephthalate, and polyethylene are preferred because of their high permeability to energy rays such as ultraviolet rays or visible rays. At least one type from the group consisting of naphthalates is more preferable.

As the anode, a conductive metal oxide film or a translucent metal thin film with a relatively large work function (suitable for having a work function greater than 4.0 eV) is generally used. Examples of anode materials include metal oxides such as indium tin oxide (hereinafter referred to as ITO) and tin oxide, and 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, and polythiophene or a derivative thereof. The anode can be formed by a two- or more-layer structure, if necessary. The film thickness of the anode can be appropriately selected taking into account electrical conductivity (light transmittance in the case of bottom emission type). 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. Methods for producing the anode include vacuum deposition, sputtering, ion plating, and plating. In the case of the top emission type, a reflective film may be installed under the anode to reflect light emitted to the substrate side.

The organic EL layer contains at least a light-emitting layer made of organic material. This light-emitting layer contains a light-emitting material. Examples of luminescent materials include organic substances (low-molecular-weight compounds or high-molecular-weight compounds) that emit fluorescence or phosphorescence. The light emitting layer may further contain a dopant material. Examples of organic materials include pigment-based materials, metal complex-based materials, and polymer materials. A dopant material is doped into 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 made of these organic materials and dopants doped as needed is usually 2 to 200 nm.

(Color-based material)

Color materials 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, tripumanylamine derivatives, oxadiazole dimers, pyrazoline dimers, etc. are mentioned.

(Metal complex system material)

Metal complex materials include metal complexes that emit light from a triplet excited state such as iridium complex and platinum complex, aluminum quinolinol complex, benzoquinolinol beryllium complex, benzoxazolyl zinc complex, benzothiazole zinc complex, and azo. and metal complexes such as methyl zinc complex, porphyrin zinc complex, and europium complex. Metal complexes include rare earth metals such as terbium (Tb), europium (Eu), and dysprosium (Dy), aluminum (Al), zinc (Zn), and beryllium (Be) as the central metal, and oxadiazole and thiazol as ligands. Diazole, phenylpyridine, phenylbenzimidazole, and metal complexes having a quinoline structure, etc. can be mentioned. Among these, a metal complex having aluminum (Al) as the center metal and a quinoline structure or the like as a ligand is preferable. Among metal complexes that have aluminum (Al) as the center metal and a quinoline structure as a ligand, tris(8-hydroxyquinolinato)aluminum is preferable.

(polymeric materials)

Polymer materials include polyparaphenylenevinylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and the above pigments and metal complex-based luminescent materials. Polymerized ones, etc. can be mentioned.

Among the above luminescent materials, materials that emit blue light include distyrylarylene derivatives, oxadiazole derivatives, polyvinylcarbazole derivatives, polyparaphenylene derivatives, polyfluorene derivatives, and polymers thereof. Among these, polymer materials are preferable. Among the polymer materials, one or more of the group consisting of polyvinylcarbazole derivatives, polyparaphenylene derivatives, and polyfluorene derivatives is preferred.

Materials that emit green light include quinacridone derivatives, coumarin derivatives, polyparaphenylenevinylene derivatives, polyfluorene derivatives, and polymers thereof. Among these, polymer materials are preferable. Among polymer materials, at least one type from the group consisting of polyparaphenylenevinylene derivatives and polyfluorene derivatives is preferred.

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 preferable. Among polymer materials, at least one type from the group consisting of polyparaphenylenevinylene derivatives, polythiophene derivatives, and polyfluorene derivatives is preferred.

(Dopant material)

Dopant materials include perylene derivatives, coumarin derivatives, rubrene derivatives, quinacridone derivatives, squaryllium derivatives, porphyrin derivatives, styryl pigments, tetracene derivatives, pyrazolone derivatives, decacyclene, phenoxazone, etc. there is.

In addition to the light-emitting layer, the organic EL layer can appropriately include a layer provided between the light-emitting layer and the anode, and a layer provided between the light-emitting layer and the cathode. First, the layer provided between the light-emitting layer and the anode includes a hole injection layer that improves hole injection efficiency from the anode, a hole transport layer that transports holes injected from the anode or the hole injection layer to the light-emitting layer, and the like. The layer provided between the light-emitting layer and the cathode includes an electron injection layer that improves electron injection efficiency from the cathode, and an electron transport layer that transports electrons injected from the cathode or the electron injection layer to the light-emitting layer.

(hole injection layer)

Materials forming the hole injection layer include phenylamines such as 4',4"-tris{2-naphthyl(phenyl)amino}triphenylamine, starburst type amines, phthalocyanines, vanadium oxide, molybdenum oxide, and oxidized amines. Oxides such as ruthenium and aluminum oxide, amorphous carbon, polyaniline, and polythiophene derivatives can be mentioned.

(hole transport layer)

Materials constituting the hole transport layer include polyvinylcarbazole or its derivatives, polysilane or its derivatives, polysiloxane derivatives with aromatic amines in the side or main chain, pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine derivatives, and benzidine. Derivatives, polyaniline or its derivatives, polythiophene or its derivatives, polyarylamine or its derivatives, polypyrrole or its derivatives, poly(p-phenylenevinylene) or its derivatives, poly(2,5-thienylenevinylene) Or its derivatives, etc. can be mentioned.

When these hole injection layers or hole transport layers have a function of blocking electron transport, these hole transport layers or hole injection layers are also called electron blocking layers.

(electron transport layer)

Materials constituting the electron transport layer include oxadiazole derivatives, anthraquinodimethane or its derivatives, benzoquinone or its derivatives, naphthoquinone or its derivatives, anthraquinone or its derivatives, tetracyanoanthraquinodimethane or its derivatives, 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, etc. there is. Derivatives include metal complexes and the like. Among these, 8-hydroxyquinoline or its derivatives are preferable. Among 8-hydroxyquinoline or its derivatives, tris(8-hydroxyquinolinato)aluminum is preferred because it can be contained in the light-emitting layer and used as an organic substance that emits fluorescence or phosphorescence.

(electron injection layer)

Depending on the type of the emitting layer, the electron injection layer may be an electron injection layer composed of a single layer structure of a calcium (Ca) layer, or a metal of Group IA and IIA of the periodic table and a work function of 1.5 to 3.0 eV, and an oxide or halide of the metal. and a single layer structure formed of one or more types of the group consisting of carbonates, or a group consisting of metals of groups 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 composed of a layered structure of a layer formed of one or more of the following and a Ca layer. Examples of Group IA metals of the periodic table or their oxides, halides, and carbonates with a work function of 1.5 to 3.0 eV include lithium (Li), lithium fluoride, sodium oxide, lithium oxide, and lithium carbonate. Metals of group IIA of the periodic table with a work function of 1.5 to 3.0 eV or their oxides, halides, and carbonates 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 called hole blocking layers.

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

The cathode may have a laminated structure of two or more layers. Examples of a two-layer or more laminate structure include a laminate structure of the above-described metals, metal oxides, fluorides, alloys thereof, and metals such as Al, Ag, and Cr. The film thickness of the cathode can be appropriately selected considering electrical conductivity and durability. The film thickness of the cathode is preferably 10 nm to 10 μm, more preferably 15 nm to 1 μm, and most preferably 20 nm to 500 nm. Methods for producing the cathode include vacuum deposition, sputtering, and a laminate method of thermocompressing a metal thin film.

The layers 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, the structure of the organic EL element used in this embodiment may have any one of the layer structures (i) to (xv) below.

(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 adjacent to each other. The same applies hereinafter.)

The encapsulation layer is provided to prevent gases such as water vapor or oxygen from contacting the organic EL element, and to seal the organic EL element with a layer having high barrier properties to the gas. This encapsulation layer is formed by alternating inorganic and organic films from below. The inorganic/organic laminate may be formed repeatedly two or more times.

In an active matrix display device in which the current to each organic EL element is controlled by a thin film transistor (TFT) installed in each pixel, unevenness of 0.5 μm to 3 μm is formed by the TFT or a partition wall dividing the blue, green, and red pixels. It exists between the cathode or anode and the encapsulation layer. In an active matrix display device, it is necessary to flatten the above-mentioned irregularities with an encapsulation layer to reduce the influence of interference with light emission and further improve encapsulation performance. Forming the sealing layer using the sealant according to the present embodiment can produce the effect of obtaining good flatness.

The inorganic film of the inorganic/organic laminate is a film installed to prevent the organic EL element from being exposed to gases such as water vapor or oxygen present in the environment in which the organic EL device is placed. It is desirable that the inorganic film of the inorganic/organic laminate is a continuous dense film with few defects such as pinholes. Examples of the inorganic film include single films such as SiN films, SiO films, SiON films, Al ₂ O ₃ films, and AlN films, or stacked films thereof.

The organic film of the inorganic/organic laminate is installed to cover defects such as pinholes formed on the inorganic film and to provide flatness to the surface. The organic film is formed in a narrower area than the area where the inorganic film is formed. This is because if the organic film is formed the same as or wider than the formation area of the inorganic film, the organic film will deteriorate in the exposed area. However, the highest organic film formed on the top layer of the entire encapsulation layer is formed in an area almost identical to the formation area of the inorganic film. Then, the upper surface of the encapsulation layer is formed to be flat. As the organic film, a composition having an adhesive function with good adhesion performance to the inorganic film described above is used.

This embodiment is, for example, suitable for inkjet coating, which enables coating with excellent flatness with a film thickness of 3 μm or more in a short time, has excellent ejection properties by inkjet and flatness after inkjet application, and has barrier properties against water vapor and the like (hereinafter also referred to as low moisture permeability). ) In addition, the purpose is to provide an encapsulant for an organic electroluminescence display device that forms the organic material film, so that the reliability of the organic EL device does not decrease due to penetration of the encapsulant itself from a pinhole on the inorganic material film. . Using an inkjet coating method, an organic film can be formed uniformly at high speed.

If the encapsulant itself penetrates from the pinhole on the inorganic film, not only will the OLED device around the pinhole stop emitting light, but when used for a long period of time, the encapsulant will penetrate into the organic luminescent material layer, increasing light emission defects and causing so-called dark spots. do. In other words, the reliability of the OLED device is significantly reduced.

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

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

γ/2η<0.9m/s...Equation 2

As will be described later, in organic EL devices, there is a problem in that dark spots occur due to penetration of an encapsulant, resulting in poor light emission. By satisfying the conditions of Equation 2 above, penetration of the encapsulant is suppressed.

The viscosity of the composition of the present embodiment, measured at 25°C and 100 rpm using an E-type viscometer, is preferably 8 mPa·s or more and 50 mPa·s or less. In cases where it is difficult to eject by inkjet, appropriately warm the inkjet head. If the viscosity is less than 8 mPa·s, the applied encapsulant for organic EL display devices not only flows out of the organic EL display devices before curing, but also flows into pinholes on the inorganic film, thereby reducing the reliability of the OLED device. If 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.

The static surface tension of the composition of this embodiment is preferably 14 mN/m or more and 40 mN/m or less. Static surface tension is measured by the plate method, ring method, pendant drop method, etc., and the static surface tension value specified in this embodiment is based on the pendant drop method. The pendant drop method refers to a method of calculating surface tension from the shape of a hanging drop (pendant drop) by pushing liquid from the end of a pipe. If the static surface tension is less than 14 mN/m, the coated encapsulant for the organic EL display device not only flows out of the organic EL display device before curing, but also flows into pinholes on the inorganic film, deteriorating the reliability of the OLED device. If 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 this embodiment is a (meth)acrylic resin composition containing (A) acyclic alkanediol di(meth)acrylate having 6 or more carbon atoms, (B) a cyclic monomer, and (C) a photopolymerization initiator. The component (B) contains at least cyclic monofunctional (meth)acrylate and cyclic difunctional (meth)acrylate.

(A) Acyclic alkanediol di(meth)acrylate having 6 or more carbon atoms refers to a difunctional (meth)acrylate in which the main chain alkane has 6 or more carbon atoms. The acyclic component (A) does not have a cyclic molecular structure. As the component (A), α,ω-linear alkanediol di(meth)acrylate is preferable because of its low moisture permeability and great effect on inkjet dischargeability and flatness after inkjet application. More preferably, the number of carbon atoms of the main chain alkane may be 12 or less. Among α,ω-linear alkanediol di(meth)acrylates, 1,6-hexadiol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and 1,10-decanediol di(meth)acrylate. ) Acrylate, 1,12-dodecanediol di(meth)acrylate, at least one type from the group is preferred, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate ) Acrylate, at least one type from the group consisting of 1,12-dodecanediol di(meth)acrylate is more preferable, and 1,12-dodecanediol di(meth)acrylate is most preferable. The alkane, which is the main chain of component (A), may be straight chain or crushed. Preferably, component (A) does not have a fluorine atom and is distinguished from component (E), which will be described later.

The content of component (A) is preferably 10 to 85 parts by mass with respect to a total of 100 parts by mass of component (A) and component (B). If the content of (A) is 10 parts by mass or more, low moisture permeability is obtained, and if the content is 85 parts by mass or less, the viscosity increases and the reliability of the organic EL device improves. 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 in terms of low moisture permeability and reliability of the organic EL device.

(B) A cyclic monomer is a monomer that has a group having a cyclic structure in the molecule and one or more unsaturated double bond groups selected from the group consisting of a (meth)acrylate group, (meth)acrylamide group, and N-vinyl group. In other words, component (B), which has a cyclic structure, is different from component (A), which is acyclic. Examples of such cyclic structures include hetero-containing cyclic structures such as cyclic amide groups, tetrahydrofurfuryl groups, and piperidinyl groups, monomers having aromatic hydrocarbon-based cyclic structures, and aliphatic hydrocarbon-based cyclic structures. Among them, at least one type from the group consisting of monomers having an aromatic hydrocarbon-based cyclic structure or an aliphatic hydrocarbon-based cyclic structure is preferable in terms of inkjet ejection properties and low moisture permeability. More preferably, a cyclic (meth)acrylate monomer having an aromatic hydrocarbon-based cyclic structure or an aliphatic hydrocarbon-based cyclic structure can be used as the component (B). Preferably, component (B) does not have a fluorine atom and is distinguished from component (E), which will be described later.

Examples of (meth)acrylates 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) Within the molecules of 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 a cyclic structure of one or more aromatic hydrocarbons, ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A Bifunctional (meth)acrylates such as di(meth)acrylate and bisphenol A epoxy di(meth)acrylate can be mentioned. You may use one or more of these in combination. In particular, the encapsulant for an organic electroluminescence display device according to the present embodiment preferably has two or more cyclic structures in the molecule from the viewpoint of low moisture permeability and reliability of the organic EL device. Examples of (meth)acrylates having two or more aromatic hydrocarbon-based cyclic structures in the molecule include ethoxylated-o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, and ethoxylated bisphenol A di(meth)acrylate. ) At least one type from the group consisting of acrylates is preferable, and at least one type from the group consisting of ethoxylated-o-phenylphenol (meth)acrylate and ethoxylated bisphenol A di(meth)acrylate is more preferable.

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 and dicyclopentenyl group, cyclohexyl group, isobornyl group, cyclodecatriene group, and nor. Bonyl group, adamantyl group, etc. can be mentioned. Among these, a group having a dicyclopentadiene skeleton is preferable. Examples of (meth)acrylates having an alicyclic hydrocarbon group include cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentanyl (meth)acrylate. Clopentenyloxyethyl (meth)acrylate, isobornyl (meth)acrylate, methoxylated cyclodecatriene (meth)acrylate, etc. are mentioned. Examples of (meth)acrylates having a dicyclopentadiene skeleton include tricyclodecane dimethanol di(meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyl. At least one type from the group consisting of oxyethyl (meth)acrylate is preferred, and at least one type from the group consisting of dicyclofentanyl (meth)acrylate and tricyclodecane dimethanol di(meth)acrylate has low moisture permeability. is more preferable.

(B) The present inventor discovered that the cyclic monomer needs to contain a mixture of cyclic monofunctional (meth)acrylate and cyclic difunctional (meth)acrylate in a predetermined ratio. This is due to the following reasons. Cyclic monofunctional (meth)acrylates are highly effective in terms of low moisture permeability, but due to their low boiling point, there is a problem in that unreacted products become outgassing, resulting in poor light emission of organic EL devices. Cyclic bifunctional (meth)acrylate has excellent low moisture permeability and low volatility, so it is highly effective in terms of OLED device reliability, but has a problem of adversely affecting inkjet ejection performance due to its relatively high viscosity. The present inventor has discovered that by using cyclic monofunctional (meth)acrylate and cyclic difunctional (meth)acrylate together in a predetermined ratio, the effect of achieving both low moisture permeability and OLED device reliability, which cannot be achieved in the prior art, can be obtained. invention has been achieved. That is, the content ratio of monofunctional (meth)acrylate and difunctional (meth)acrylate is the mass ratio of the total of 100 parts by mass of methacrylate and acrylate: monofunctional (meth)acrylate:bifunctional (meth)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 structural formula below:

(R ₁ in the above formula is each 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 - (where 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 one of the substituents represented by the structural formula below).

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

It is preferable that at least one of the components (B) has two or more cyclic structures in the molecule, and it is more preferable that at least two of the components have two or more cyclic structures in the molecule.

The content of component (B) is preferably 15 to 90 parts by mass with respect to a total of 100 parts by mass of component (A) and component (B). If the content of (B) is 15 parts by mass or more, the viscosity increases and the reliability of the organic EL device improves, and if the content of (B) is 90 parts by mass or less, it is excellent in terms of inkjet coating properties. 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 promote photocuring of the resin composition by sensitizing or reducing it with visible or ultraviolet actinic light. As a photopolymerization initiator, a radical photopolymerization initiator is preferable. Photoradical polymerization initiators 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. benzoin derivatives, diethoxyacetophenone, acetophenone derivatives such as 4-tert-butyltrichloroacetophenone, 2-dimethylaminoethylbenzoate, p-dimethylaminoethylbenzoate, diphenyl disulfide, thioxanthone, and Its derivatives, camphorquinone, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxylic acid, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane -1-Carboxy-2-bromoethyl ester, 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxy-2-methyl ester, 7,7-dimethyl-2,3 - Camphorquinone derivatives such as dioxobicyclo[2.2.1]heptane-1-carboxylic acid chloride, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2 -Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1 and other α-aminoalkylphenone derivatives, benzoyl diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl -Phosphine oxide, benzoyl diethoxyphosphine oxide, 2,4,6-trimethylbenzoyldimethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiethoxyphenylphosphine oxide, bis(2,4,6- Acylphosphine oxide derivatives such as trimethylbenzoyl)-phenylphosphine oxide, phenyl-glyoxylic acid-methyl ester, oxy-phenyl-acetic acid 2-[2-oxo-2-phenyl-acetoxy-ethoxy] -Ethyl ester, oxy-phenyl-acetic acid, 2-[2-hydroxy-ethoxy]-ethyl ester, etc. are mentioned. Photopolymerization initiators can be used in combination of one or more types. Among these, acylphosphine oxide derivatives are preferable because they can be cured using only visible light of 390 nm or more and can be cured without damaging the organic electroluminescence display element. Among acylphosphine oxide derivatives, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide is most preferable because it can be cured using only light of 395 nm or longer without decreasing the transparency of visible light when used as a display. do. Examples of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide include “Irgacure TPO” manufactured by BASF Japan.

(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, and most preferably 2 to 3.9 parts by mass, based on a total of 100 parts by mass of the components (A) and (B). 2.5 to 3.5 parts by mass is more preferable. If the content of component (C) is 0.05 parts by mass or more, the curing acceleration effect can be clearly obtained, and if the content of component (C) is 6 parts by mass or less, the transmittance to visible light does not decrease when used in a display.

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

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

The content of 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 a total of 100 parts by mass of component (A) and component (B). If it is 0.1 parts by mass or more, flatness can be ensured, and if it is 10 parts by mass or less, good inkjet applicability can be ensured.

The number of fluorine atoms in the fluorine-containing monomer as component (E) may be 1 or more, for example, 2 or more, and is preferably 3 or more. Additionally, 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 is preferably 30 or less.

The content of fluorine atoms 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. Additionally, the content of fluorine atoms may be, for example, 75% by mass or less, preferably 70% by mass or less, and more preferably 65% by mass or less, based on the total amount of fluorine-containing monomers. Additionally, the content of fluorine atoms relative to the total amount of the composition according to the embodiment containing component (E) is preferably 0.01 to 10% by mass, and more preferably 0.1 to 5% by mass. If the content of fluorine atoms is within the above range, the effect of improving flatness can be exhibited.

The number of (meth)acryloyl groups that the fluorine-containing monomer has may be 1 or more. From the viewpoint of making it easy to obtain a cured product with a low glass transition temperature, the number of (meth)acryloyl groups in the fluorine-containing monomer may be 1. Additionally, from the viewpoint of making it easy to obtain a cured product with a high glass transition temperature, the number of (meth)acryloyl groups in the fluorine-containing monomer may be 2 or more. The upper limit of the number of (meth)acryloyl groups that the fluorine-containing monomer has is not particularly limited, and can be, for example, 4 or less. From the viewpoint of making it easier to obtain a cured product with excellent flexibility, it is preferably 3 or less, more preferably 2. It is as follows.

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

Equation (E-1)

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

A fluorinated alkyl group can be said to be a group in which some or all of the hydrogen atoms of the alkyl group are replaced with fluorine atoms. The number of carbon atoms of the fluorinated alkyl group is not particularly limited, and may be, for example, 1 or more, and is preferably 2 or more. In addition, the number of carbon atoms of the fluorinated alkyl group may be, for example, 25 or less, and may be 20 or less.

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

Specific examples of fluorinated alkyl groups include difluoromethyl group, trifluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 1,1,1-trifluoroethyl group, 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, 1,1,2,2,3,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis(trifluorobutyl group) r)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, 1,1,2,2,3,3,4,4,4,5,5-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 into a portion of the carbon-carbon bond or carbon-hydrogen bond in a fluorinated alkyl group (hereinafter also referred to as the oxygen-containing group of R ² ) may be a group in which an oxygen atom is inserted in one place, and may be inserted in two or more places. It can be any device that has been developed.

Also, when an oxygen atom is inserted into a carbon-carbon bond, an ether bond is formed. Additionally, when an oxygen atom is inserted into a carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of R ² may be said to be a group containing at least one type selected from the group consisting of an ether bond and a hydroxyl group.

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

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

One specific example of the compound represented by formula (E-1) includes, for example, a compound represented by the following formula (E-1-1).

Equation (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. A plurality of R ²¹ may be the same or different from each other. However, at least one of R ²¹ is a fluorine atom.

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

R ²¹ exists in plural numbers in formula (E-1-1), but at least one of them is a fluorine atom. Moreover, it is preferable that two or more of R ²¹ are fluorine atoms, and it is more preferable that three or more of R 21 are fluorine atoms. All R ²¹ may be fluorine atoms.

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

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

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

Equation (E-2)

In formula (E-2), R ³ represents a hydrogen atom or a methyl group. Additionally, R ⁴ represents a fluorinated alkanediyl group or a group in which an oxygen atom is inserted into a portion of the carbon-carbon bond and carbon-hydrogen bond in the fluorinated alkanediyl group. A plurality of 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 replaced 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.

Specific examples of the fluorinated alkanediyl group include linear or branched fluorinated alkanediyl groups 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), fluorinated cycloalkanediyl group having 1 to 17 carbon atoms, etc.

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

Also, when an oxygen atom is inserted into a carbon-carbon bond, an ether bond is formed. Additionally, when an oxygen atom is inserted into a carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of R ⁴ may be said to be a group containing at least one type selected from the group consisting of an ether bond and a hydroxyl group.

Specific examples of the oxygen-containing group of R ⁴ include groups represented by the following formula.

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

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

Equation (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. A plurality of R ⁴¹ may be the same or different from each other. A plurality of R ³ may be the same or different from each other. However, at least one of R ⁴¹ is a fluorine atom.

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

R ⁴¹ exists in plural numbers in formula (E-2-1), but at least one of them is a fluorine atom. Moreover, it is preferable that two or more of R ⁴¹ are fluorine atoms, and it is more preferable that four or more of R 41 are fluorine atoms. All R ⁴¹ may be fluorine atoms.

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

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

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

Equation (E-3)

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

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

The aryl fluoride group for Ar ¹ is preferably a phenyl fluoride group. A fluorinated phenyl group may be said to be a group in which 1 to 5 hydrogen atoms in the phenyl group are replaced with fluorine atoms. The fluorinated phenyl group may have one or more fluorine atoms, and may have five fluorine atoms.

The number of carbon atoms of 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 of the alkanediyl group of R ⁶ may be, for example, 17 or less, preferably 15 or less, and more preferably 12 or less.

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

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 replaced with fluorine atoms. The number of carbon atoms of 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 of 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 for R ⁶ , a group containing difluoromethylene (-CF ₂ -) can be suitably used.

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

Also, when an oxygen atom is inserted into a carbon-carbon bond, an ether bond is formed. Additionally, when an oxygen atom is inserted into a carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of R ⁶ may be said to be a group containing at least one type selected from the group consisting of an ether bond and a hydroxyl group.

Specific examples of the oxygen-containing group of R ⁶ include a group 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. Additionally, the fluorine atom content in the compound represented by formula (E-3) may be, for example, 90 mass% or less, preferably 80 mass% or less, and more preferably 70 mass% or less.

One specific example of the compound represented by formula (E-3) includes, for example, a compound represented by the following formula (E-3-1).

Equation (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. When p is 1 or more, the plurality of R ⁶¹ may be the same or different from each other. In addition, plural R ⁶² may be the same or different from each other. However, at least one of R ⁶² is a fluorine atom.

p represents an integer greater than or equal to 0. Here, p of 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 exists in formula (E-3-1) (i.e., when p is an integer of 1 or more), R ⁶¹ may be all hydrogen atoms, all may be fluorine atoms, or may be partially hydrogen atoms and the remainder may be fluorine atoms. .

R ⁶² exists in plural numbers in formula (E-3-1), at least one of which is a fluorine atom. Additionally, two or more of R ⁶² may be fluorine atoms, and three or more of R 62 may be fluorine atoms. Additionally, all (5) of R ⁶² 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. This ratio may be, for example, 100% or less, preferably 95% or less, and more preferably 80% or less.

Among fluorine-containing monomers, 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluoro is preferred from the viewpoint of low moisture permeability and inkjet applicability. -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 types from the group.

Considering the reliability of the organic EL device, the glass transition temperature of the cured body obtained from the composition of this embodiment is preferably 65°C or higher and 120°C or lower, more preferably 65°C or higher and 110°C or lower, and most preferably 70°C or higher and 100°C or lower. desirable. If the glass transition temperature of the cured body is in the range of 65 ° C. to 120 ° C., when forming an inorganic passivation film on the cured body of the composition of the present embodiment by a method such as CVD, stress is relieved, making it difficult for the inorganic film and the OLED element to separate. Therefore, the reliability of the organic EL device is improved.

The method for measuring the glass transition temperature of the cured body obtained from the composition of the present embodiment is not particularly limited, but is measured by known methods such as DSC and dynamic viscoelasticity spectrum, and dynamic viscoelasticity spectrum is preferably used. In the dynamic viscoelasticity spectrum, stress and strain are applied to the cured body at a constant temperature increase rate, and the temperature showing the peak top of the loss tangent (hereinafter referred to as tan δ) can be set as the glass transition temperature. If the peak of tanδ does not appear even if the temperature is raised from a sufficiently low temperature of about -150℃ to a certain temperature (Ta℃), the glass transition temperature is considered to be below -150℃ or above a certain temperature (Ta℃). Since compositions below -150℃ cannot be considered due to their structure, they can be set at a certain temperature (Ta℃) or higher.

The composition of this embodiment may use (D) an antioxidant to improve storage stability. Antioxidants include methylhydroquinone, hydroquinone, 3-[3,5-di-tert-butyl-4-hydroxyphenyl]octadecyl propionate, and 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, etc. I can hear it. It is preferable to combine two or more types of antioxidants. Among these, phenolic antioxidants are preferable because they have great effects such as transparency and storage stability. Among phenol-based antioxidants, hindered phenol-based antioxidants are preferable. Hindered phenol-based antioxidants include 3-[3,5-di-tert-butyl-4-hydroxyphenyl]octadecyl propionate and 2,2-methylene-bis(4-methyl-6-tert-butylphenol). At least one member of the group consisting of is preferred, 3-[3,5-di-tert-butyl-4-hydroxyphenyl]octadecyl propionate and 2,2-methylene-bis(4-methyl-6-tert-butyl It is more preferable to contain phenol). Examples of 3-[3,5-di-tert-butyl-4-hydroxyphenyl]octadecyl propionate include “Irganox 1076” manufactured by BASF Japan. Examples of 2,2-methylene-bis(4-methyl-6-tert-butylphenol) include “SUMILIZER MDP-S” manufactured by Sumitomo Chemical Industries, Ltd. When containing 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- 3-[3,5- in mass ratio out of 100 parts by mass of the total of di-tert-butyl-4-hydroxyphenyl]octadecyl propionate and 2,2-methylene-bis(4-methyl-6-tert-butylphenol) di-tert-butyl-4-hydroxyphenyl] octadecyl propionate: 2,2-methylene-bis (4-methyl-6-tert-butylphenol) = 10 to 90: 90 to 10 is preferred, 25 to 75 :75 to 25 is 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 a total of 100 parts by mass of component (A) and component (B). If it is 0.001 parts by mass or more, storage stability is ensured, and if it is 3 parts by mass or less, good adhesiveness can be obtained and non-curing does not occur.

The composition according to the present embodiment may further contain additives used in the relevant technical field, for example, antioxidants, metal deactivators, fillers, stabilizers, neutralizers, lubricants, antibacterial agents, etc.

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 sealant for organic EL display elements.

A method of curing the composition by irradiating visible light or ultraviolet rays includes curing the composition by irradiating at least one of visible rays or ultraviolet rays. Energy sources for irradiating visible or ultraviolet rays include deuterium lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps, xenon lamps, xenon-mercury hybrid lamps, halogen lamps, excimer lamps, indium lamps, thallium lamps, and LED lamps. , energy irradiation sources such as electrodeless discharge lamps. The composition of this embodiment is preferably cured at a wavelength of 380 nm or more because it is difficult to damage the organic EL element, more preferably cured at a wavelength of 395 nm or more, and most preferably cured at a wavelength of 395 nm. The wavelength of the energy irradiation source is preferably 500 nm or less because emitting infrared light may increase the temperature of the irradiated area and cause damage to the organic EL element. As an energy irradiation source, an LED lamp with a short emission wavelength is preferable.

When curing the composition by irradiating visible light or ultraviolet rays, it is preferable to irradiate the composition with an energy ray of 100 to 8000 mJ/cm2 at a wavelength of 395 nm. If it is 100 to 8000 mJ/cm2, the composition can be cured and sufficient adhesive strength can be obtained. If it is 100mJ/cm2 or more, the composition is sufficiently cured, and if it is 8000mJ/cm2 or less, there is no damage to the organic EL device. The amount of energy when curing the composition is more preferably 300 to 2000 mJ/cm2.

The transparency of the composition of this embodiment is preferably 95% or more, more preferably 97% or more, and 99% or more in the spectral transmittance in the ultraviolet-visible range of 360 nm to 800 nm when the thickness of the organic film is 1 μm or more and 10 μm or less. Most desirable. If it is 95% or more, an organic EL device with excellent luminance and contrast can be provided.

It is preferable that the number of encapsulating layers made of the composition of this embodiment is 1 to 5, counting the inorganic/organic laminate as one set. This is because when there are 6 or more sets of inorganic/organic laminates, the encapsulation effect on the organic EL device becomes almost the same as when there are 5 sets. The thickness of the inorganic film of the inorganic/organic laminate is preferably 50 nm to 1 μm. The thickness of the organic film of the inorganic/organic laminate is preferably 1 to 15 μm, and more preferably 3 to 10 μm. If the thickness of the organic film is less than 1 μm, it may not be possible to completely cover the particles generated during device formation, making it difficult to apply it evenly on the inorganic film. If the thickness of the organic film exceeds 15 μm, moisture may enter from the side of the organic film and the reliability of the organic EL device may deteriorate.

The encapsulation substrate is formed in close contact with the uppermost organic film of the encapsulation layer to cover the entire upper surface. Examples of this encapsulation substrate include the above-mentioned substrates. Among these, a substrate transparent to visible light is preferable. Among substrates transparent to visible light (transparent encapsulation substrates), at least one type from 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 installing a transparent encapsulation substrate on an upper layer of the encapsulation layer, deterioration that occurs when the surface of the uppermost organic film comes into contact with a gas can be suppressed and the barrier properties of the organic EL device can be improved.

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

Next, a first inorganic film having a predetermined thickness is formed on the substrate on which the organic EL device is formed by a film forming method such as a PVD (Physical Vapor Deposition) method such as a sputtering method or a CVD method such as a plasma CVD (Chemical Vapor Deposition) method. do. Thereafter, the composition of the present embodiment is deposited on the first inorganic film using a coating film forming method such as a solution coating method or a spray coating method, a flash evaporation method, an inkjet method, or the like. Among these, the inkjet method is preferable in terms of productivity. Thereafter, the composition is cured by irradiation of energy rays such as ultraviolet rays, electron beams, or plasma, and a first organic film is formed. Through the above processes, 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 achieved, but can be, for example, 90% or more, preferably 95% or more, as a value obtained according to a measurement method described later.

The formation process of the inorganic/organic laminate shown above is repeated a predetermined number of times. However, for the last set, that is, the uppermost layer of the inorganic/organic laminate, the composition may be attached to the upper surface of the inorganic film by a coating method, flash evaporation method, inkjet method, etc. so that the upper surface is flat.

Next, the transparent encapsulation substrate is aligned and attached to the surface on the substrate to which the composition was attached. When aligning, perform position alignment. Thereafter, the composition of this embodiment existing between the uppermost inorganic film and the transparent sealing substrate is cured by irradiating energy rays from the transparent sealing substrate side. Accordingly, the composition is cured to form a top-level organic film, and the top-level organic film and the transparent encapsulation substrate are bonded. This concludes the manufacturing method of the organic EL device.

After attaching the composition on the inorganic film, it may be partially polymerized by irradiating energy rays. By doing this, it is possible to prevent the composition, which becomes the top organic film, from collapsing in shape when the transparent encapsulation substrate is placed on it. 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 was used as an example. This embodiment can also be applied to a bottom emission type organic EL device in which light generated in the organic EL layer is emitted from the substrate side.

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

According to this embodiment, an encapsulation layer is formed to block the organic EL device formed on the first substrate from external air, and a transparent encapsulation substrate is disposed on the encapsulation layer, thereby ensuring sufficient water vapor and oxygen to the organic EL device. An encapsulation structure with barrier properties can be obtained. According to this embodiment, it is possible to obtain a sealing structure having sufficient adhesive strength between the transparent sealing substrate and the sealing layer.

According to this embodiment, after attaching the composition of this embodiment, which constitutes the uppermost organic film of the encapsulation layer, a transparent encapsulation substrate is placed on it without curing the composition, and the composition is then cured, so that the composition of the uppermost organic film, which constitutes the encapsulation layer, is cured. Upon formation, adhesion between the encapsulation layer and the transparent encapsulation substrate can be performed. As a result, this embodiment has the effect of simplifying the process compared to the case of adhering the encapsulation layer and the transparent encapsulation substrate 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, as measured by exposing the cured product to an environment of 85° C. and 85% RH for 24 hours in accordance with JIS Z 0208:1976. If the moisture permeability exceeds 350 g/m 2 , moisture may reach the organic light-emitting material layer and dark spots may occur.

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

Example

(Experimental Examples 1 to 8)

A composition was produced and evaluated by the following method.

(Production of composition)

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

[E-type viscosity (η)]

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

[Surface tension (γ)]

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

[Light curing conditions]

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

[Water permeability]

A sheet-shaped cured body with a thickness of 0.1 mm was produced under the above photocuring conditions, and calcium chloride (anhydrous) was used as a moisture absorbent in accordance with JIS Z0208:1976 “Testing method for moisture permeability of moisture-proof packaging materials (cup method)” at an ambient temperature of 85°C. Measurements were made under conditions of 85% humidity.

[hardening rate]

For the composition obtained in each experimental example, the composition was applied to a size of 10 mm x 10 mm on alkali-free glass cleaned by the above-described method to a thickness of 10 μm using the inkjet device, and the composition was applied in a nitrogen atmosphere with an oxygen concentration of less than 0.1%. It was cured under the above photocuring conditions and the curing rate was measured in the following procedure.

Infrared light was incident on the composition after curing and the composition before curing using an infrared spectrometer (Thermo Scientific, Nicolet is5, DTGS detector, resolution 4 cm ^{- 1} ) to measure the infrared spectral spectrum. In the obtained infrared spectral spectrum, the stretching vibration peak of the carbon-hydrogen bond of the methylene group observed around 2950 cm ^-1 , which does not cause a peak change before and after curing, was set as an internal standard, and the peak area before and after curing of this internal standard was calculated as (meta) ) The curing rate was calculated using the following equation 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 bonded to the carbon-carbon double bond of acrylate.

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

here,

Ao: represents the peak area before curing around 810 cm ^-1 .

Ax: represents the peak area after curing around 810 cm ^-1 .

Bo: represents the peak area before curing around 2950 cm ^-1 .

Bx: represents the peak area after curing 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 was cured by irradiating at an irradiation amount of 1500 mJ/cm2 to obtain a cured body. The obtained cured body was measured for transparency at 380 nm, 412 nm, and 800 nm using an ultraviolet-visible spectrophotometer ("UV-2550" manufactured by Shimadzu Corporation).

[Glass transition temperature]

The composition obtained in each experimental example was inserted into a PET film using a 1 mm thick silicone sheet as a template. This composition was cured from the top under the above photocuring conditions and then further cured from below under the above photocuring conditions to produce a cured body of the above composition with a thickness of 1 mm. The produced cured body was cut into 50 mm in length and 5 mm in width with a cutter to obtain a cured body for measuring the glass transition temperature. The obtained cured body was subjected to stress and strain in the tensile direction at 1 Hz in a nitrogen atmosphere using a dynamic viscoelasticity measuring device "DMS210" manufactured by Seiko Electronics, Inc., and the temperature was raised from -150°C to 200°C at a rate of 2°C per minute while tanδ was measured. was measured, and the temperature of the peak top of this tan δ was taken as the glass transition temperature. The peak top of tanδ was set as the maximum value in the region where tanδ is 0.3 or more. When tanδ is 0.3 or less in the range of -150°C to 200°C, the peak top of tanδ is said to exceed 200°C and the glass transition temperature is said to exceed 200°C (200<).

[Expansion rate of application area]

The composition obtained in each experimental example was spread on a 70 mm x 70 mm x 0.7 mmt base material (alkali-free glass (Eagle A pattern was applied to 4 mm × 4 mm × 10 μmt. The alkali-free glass was cleaned with acetone and isopropanol before use, and then cleaned for 5 minutes using UV ozone cleaning device UV-208 manufactured by Techno Vision. Immediately after pattern application, the pattern was left for 5 minutes under conditions of an atmospheric temperature of 23°C and a relative humidity of 50%, and the flatness after inkjet application was evaluated based on the enlargement ratio of the application area (see the formula below). It was evaluated that the smaller the enlargement rate of the application area, the better the shape after application was maintained and the better the position control.

(Expansion rate of application area) = ((Contact area of the composition in contact with the surface of the base material 5 minutes after pattern application)/(Contact area of the composition in contact with the surface of the base material immediately after pattern application)) x 100 (%)

[flatness]

On a 70 mm x 70 mm x 0.7 mmt base material (alkali-free glass (Eagle In addition, the base material was cleaned with acetone and isopropanol before use, and then cleaned for 5 minutes using UV ozone cleaning device UV-208 manufactured by Techno Vision. Next, a 200 nm SiN film was formed by plasma CVD on the substrate with the concave portion. Next, the encapsulant was applied in a pattern to 50 mm x 50 mm x 10 µmt using an inkjet ejection device (MID500B, manufactured by Musashi Engineering Co., Ltd., solvent-based head "MID Head"). After applying the pattern, it was left for 5 minutes at a temperature of 23°C and a relative humidity of 50%, and the shape of the sealant film was observed. The flatness of the encapsulant was determined using the following equation. The results are shown in Table 1.

Flatness (%) = (Area of sealant film after left for 5 minutes)/(50mm x 50mm)

Also, for example, flatness of 50% indicates that part of the pattern-coated encapsulant falls off and the SiN film is exposed in half (50%) of the range of 50 mm x 50 mm.

[Organic EL evaluation]

[Production of organic EL device substrate]

A glass substrate (thickness 700 μm) with an ITO electrode of 30 mm in width and height attached was cleaned using acetone and isopropanol, respectively. Thereafter, the following compounds were sequentially deposited to form a thin film using a vacuum deposition method to obtain a substrate having an organic EL element measuring 2 mm by 2 mm consisting of an anode/hole injection layer/hole transport layer/light-emitting layer/electron injection layer/cathode. The composition of each floor 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)

·Emitting layer tris(8-hydroxyquinolinato)aluminum (metal complex material), emitting layer thickness 1000Å, emitting layer also functions as an electron transport layer.

·Electron injection layer lithium fluoride

·Cathode aluminum, film thickness 150nm

[Production of organic EL device]

After that, a mask (cover) with an opening of 10 mm x 10 mm was installed to cover the 2 mm x 2 mm organic EL element, and a SiN film was formed by plasma CVD. Next, the composition (organic film) obtained in each experimental example was applied to a thickness of 10 μm to cover an organic EL device of 2 mm × 2 mm using the inkjet device 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 installed to cover the entire cured body, and a SiN film was formed by plasma CVD to obtain an organic EL display element.

The thickness of the formed SiN (inorganic film) was about 1 μm. Afterwards, an organic EL device was produced by attaching it to alkali-free glass (Eagle

〔Early〕

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

〔durability〕

After exposing the organic EL device immediately after production for 70 hours at 85°C and 85 mass% relative humidity, apply a voltage of 6 V, observe the light emission state of the organic EL device with the naked eye and a microscope, and measure the diameter of the dark spot. did.

The diameter of the dark spot can be determined as an index for evaluating the degree of penetration of the encapsulant into the pinhole of the passivation layer and the degree to which moisture in the encapsulant is discharged as out gas. The diameter of the dark spot was evaluated to be preferably 300 μm or less, more preferably 50 μm or less, and most preferably no dark spot.

The following was found from the above experimental example.

The composition according to this embodiment can provide a composition that is excellent in the reliability of organic EL elements, ejection properties by high-precision inkjet, shape retention after inkjet application, and low moisture permeability.

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

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

On the other hand, when acyclic alkanediol di(meth)acrylate with less than 6 carbon atoms was used as (A), the enlargement rate of the application area was large and the shape after inkjet application could not be maintained, that is, there was a problem with shape maintenance (Experimental example) 12). When the content of component (A) exceeded 85 parts by mass and the content of component (B) was less than 15 parts by mass, the viscosity was low and the formula (III) was not satisfied, and shape maintenance and reliability were not obtained (Experimental Example 13 ). (B), when long-chain alkyl monofunctional acrylate and cyclic difunctional methacrylate are used instead of cyclic monofunctional (meth)acrylate, formula (III) is not satisfied due to low viscosity, and reliability, shape retention, and poor performance are poor. Moisture permeability was not obtained (Experimental Example 14). As (A), an acyclic alkanediol dimethacrylate with 6 or more carbon atoms is used, and as (B), two types of cyclic (meth)acrylates are used, satisfying formulas (II) to (III) and having a viscosity exceeding 50 mPa·s. In the case of , the low moisture permeability was excellent, but inkjet ejection was not possible, so reliability and shape maintenance could not be evaluated (Experimental Example 15). (B) When only cyclic monofunctional acrylate was used instead of cyclic difunctional (meth)acrylate, and formulas (I) to (III) were satisfied, transparency and shape retention were poor (Experimental Example 16) .

The composition of this embodiment has excellent ejection properties by high-precision inkjet and flatness after inkjet application, has low moisture permeability and transparency, and does not deteriorate the organic EL element. This embodiment allows inkjet application in a short time. The composition of the present embodiment is used in electronic products, especially display components such as organic EL (e.g., flexible displays or organic EL devices used in wearable products, etc.), electronic components such as image sensors such as CCD and CMOS, and even semiconductors. It can be suitably applied to adhesion of device packages used in parts, etc. In particular, it is optimal for adhesion for organic EL encapsulation, and satisfies the properties required for adhesives for device packages such as organic EL devices and coating materials for device packages.

The composition is one aspect of the present embodiment, and the encapsulant for organic EL elements, the cured body, the organic EL device, the display, and the manufacturing method thereof of the present embodiment also have the same structure and effect.

Claims (29)

(A) acyclic alkanediol di(meth)acrylate having 6 or more carbon atoms, (B) a cyclic monomer, (C) a photopolymerization initiator, and (E) a fluorine-containing monomer having a fluorine atom and a (meth)acryloyl group. Contains,
(B) The cyclic monomer contains cyclic monofunctional (meth)acrylate and cyclic difunctional (meth)acrylate,
An encapsulant for an organic electroluminescence display device that satisfies both the following formulas (I) and (III).
8mPa·s≤η≤50mPa·s···(I)
γ/2η<0.9m/s···(III)
(In the formula, 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) acyclic alkanediol di(meth)acrylate having 6 or more carbon atoms, (B) a cyclic monomer, (C) a photopolymerization initiator, and (E) a fluorine-containing monomer having a fluorine atom and a (meth)acryloyl group. Contains,
Containing 10 to 85 parts by mass of component (A) and 15 to 90 parts by mass of component (B), based on a total of 100 parts by mass of component (A) and component (B),
(B) The cyclic monomer contains cyclic monofunctional (meth)acrylate and cyclic difunctional (meth)acrylate,
The content ratio of cyclic monofunctional (meth)acrylate and cyclic difunctional (meth)acrylate is the mass ratio of cyclic monofunctional (meth)acrylate ( Meth)acrylate: Cyclic bifunctional (meth)acrylate = 10~95:90~5, and
An encapsulant for an organic electroluminescence display device that satisfies 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)
(In the formula, 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.) In claim 1 or claim 2,
(B) An encapsulant for an organic electroluminescence display element, wherein the cyclic monomer contains one or more types of alicyclic monomer. delete In claim 1 or claim 2,
An encapsulant for an organic electroluminescence display device 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. In claim 1 or claim 2,
An organic electrolumine wherein the fluorine-containing monomer contains at least one 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). Encapsulant for sense display elements.
Equation (E-1)
[Formula 1]

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

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

[In equation (E-3),
R ⁵ represents a hydrogen atom or a methyl group,
R ⁶ represents a single bond, an alkanediyl group, a fluorinated alkanediyl group, or a group in which an oxygen atom is inserted into a portion of the carbon-carbon bond and carbon-hydrogen bond in the alkanediyl group or fluorinated alkanediyl group,
Ar ¹ represents an aryl fluoride group.] In claim 6,
The fluorine-containing monomer is at least one 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). An encapsulant for an organic electroluminescence display device comprising:
Equation (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. A plurality of R ²¹ may be the same or different from each other. However, at least one of R ²¹ is a fluorine atom.]
Equation (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. A plurality of R ⁴¹ may be the same or different from each other. A plurality of R ³ may be the same or different from each other. However, at least one of R ⁴¹ is a fluorine atom.]
Equation (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. . A plurality of R ⁶¹ may be the same or different from each other. A plurality of R ⁶² may be the same or different from each other. However, at least one of R ⁶² is a fluorine atom.] In claim 1 or claim 2,
An encapsulant for an organic electroluminescence display element, characterized in that the content of component (E) is in the range of 0.1 parts by mass to 10 parts by mass based on a total of 100 parts by mass of the component (A) and component (B). In claim 1 or claim 2,
(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( Contains at least one member selected from the group consisting of meta)acrylate, 1H,1H,5H-octafluoropentyl(meth)acrylate, and 1H,1H,2H,2H-tridecafluorooctyl(meth)acrylate. An encapsulant for an organic electroluminescence display device, characterized in that: In claim 1 or claim 2,
An encapsulant for an organic electroluminescence display device, characterized in that it is applied using an inkjet method. In claim 1 or claim 2,
An organic electroluminescence display device characterized in that it does not contain bifunctional (meth)acrylate oligomers, bifunctional (meth)acrylate polymers, polyfunctional (meth)acrylate oligomers, or polyfunctional (meth)acrylate polymers. Dragon encapsulation agent. In claim 1 or claim 2,
An encapsulant for an organic electroluminescent display element, characterized in that the glass transition temperature of the cured body is 65°C or more and 120°C or less. In claim 1 or claim 2,
(B) An encapsulant for an organic electroluminescence display device, wherein at least one of the components has two or more cyclic structures in the molecule. In claim 1 or claim 2,
(B) An encapsulant for an organic electroluminescence display device, wherein at least two of the components have two or more cyclic structures in the molecule. In claim 1 or claim 2,
(B) Components include ethoxylated-o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, and ethoxylated bisphenol A represented by the following structural formula: An encapsulant for an organic electroluminescence display device, characterized in that it contains at least one member of the group consisting of di(meth)acrylates.
[Formula 7]

(R in the formula is each independently a hydrogen atom or a methyl group. For m and n in the formula, m+n=2 to 10) In claim 1 or claim 2,
(A) An encapsulant for an organic electroluminescent display element, characterized in that the component is an alkanediol di(meth)acrylate having 12 or less carbon atoms. In claim 1 or claim 2,
(A) One member of the group consisting of 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and 1,12-dodecanediol di(meth)acrylate. An encapsulant for an organic electroluminescent display device characterized by containing the above. In claim 1 or claim 2,
(C) An encapsulant for an organic electroluminescent display element, characterized in that the component contains 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. In claim 1 or claim 2,
(C) An encapsulant for an organic electroluminescent display element, characterized in that the content of the component is 0.5 to 4 parts by mass. In claim 1 or claim 2,
(D) An encapsulant for an organic electroluminescence display device, characterized by further containing an antioxidant. In claim 20,
(D) An encapsulant for an organic electroluminescent display element, characterized in that the ingredient is a hindered phenol-based antioxidant. In claim 20,
(D) An encapsulant for an organic electroluminescence display device, characterized in that it contains two or more types of components. In claim 1 or claim 2,
An encapsulant for an organic electroluminescence display device, characterized in that it is cured at a wavelength of 395 nm or more and 500 nm or less. In claim 23,
An encapsulant for organic electroluminescent display elements that is cured with a 395 nm LED lamp. A cured body obtained by curing the encapsulant for an organic electroluminescent display element according to claim 1 or 2. An organic EL device comprising the cured body according to claim 25. A display comprising the cured body according to claim 25. A display having flexibility, comprising the cured body according to claim 25. An organic EL device having flexibility, comprising the cured body according to claim 25.