TWI859141B - Sealant for organic electroluminescent display elements - Google Patents

Abstract

The sealant for an organic electroluminescent display element of the present invention comprises: a monomer component including a fluorine-containing monomer (A) having a fluorine atom and a (meth)acryl group; and a photopolymerization initiator.

Description

Sealant for organic electroluminescent display element

The present invention relates to a sealant for an organic electroluminescent (EL) display element, a cured body of the sealant for an organic EL display element, a sealant for an organic EL display element including the cured body, and an organic EL display device including the sealant.

Organic electroluminescent display elements (also called organic EL display elements, organic EL elements or OLED (Organic Light Emitting Diode) elements) have attracted much attention as elements that can emit light with higher brightness. However, organic EL display elements have the problem of deterioration due to moisture, and the luminescence characteristics are reduced.

To solve this problem, the industry is researching technologies to seal organic EL display elements to prevent degradation caused by moisture (e.g., patent documents 1 to 3). Previous technical documents Patent documents

Patent document 1: Japanese Patent Publication No. 10-74583 Patent document 2: Japanese Patent Publication No. 2001-307873 Patent document 3: Japanese Patent Publication No. 2009-37812

[The problem the invention is trying to solve]

In recent years, the industry has been demanding higher performance for organic EL display elements, and has been demanding sealing materials that can achieve higher reliability.

One of the purposes of the present invention is to provide a sealant for an organic EL display element that has excellent wettability with a glass substrate and can efficiently seal an organic EL display element. Another purpose of the present invention is to provide a sealant for an organic EL display element that includes a cured product of the sealant. Furthermore, another purpose of the present invention is to provide an organic EL display device that includes the sealant. [Technical means for solving the problem]

One aspect of the present invention relates to a sealant for an organic electroluminescent display element, comprising: a monomer component including a fluorine-containing monomer (A) having a fluorine atom and a (meth)acryl group; and a photopolymerization initiator.

The above-mentioned sealant for organic electroluminescent display element has excellent wettability with glass substrates and the like, and thus can efficiently seal the organic EL display element.

In one aspect, the fluorine atom content of the fluorine-containing monomer may be 2-75 mass % based on the total amount of the fluorine-containing monomer.

In one aspect, the fluorine atom content of the monomer component may be 0.1 to 75 mass % based on the total amount of the monomer component.

In one aspect, the fluorine-containing monomer may include a compound having 3 to 25 fluorine atoms.

In one embodiment, the fluorine-containing monomer may include at least one selected from the group consisting of a compound represented by formula (A-1), a compound represented by formula (A-2), and a compound represented by formula (A-3). [In formula (A-1), ^R1 represents a hydrogen atom or a methyl group, and ^R2 represents a fluorinated alkyl group, or a group in which an oxygen atom is inserted into a portion of the carbon-carbon bond and the carbon-hydrogen bond of the fluorinated alkyl group] [Chemical 2] [In formula (A-2), R ³ represents a hydrogen atom or a methyl group, and 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 the carbon-hydrogen bond of the fluorinated alkanediyl group. The presence of a plurality of R ³ groups may be the same or different] [Chemical 3] [In formula (A-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 the carbon-hydrogen bond in the alkanediyl group or the fluorinated alkanediyl group, and Ar ¹ represents a fluorinated aryl group]

In one embodiment, the fluorine-containing monomer may include at least one selected from the group consisting of a compound represented by formula (A-1-1), a compound represented by formula (A-2-1), and a compound represented by formula (A-3-1). [In formula (A-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 greater than 1. A plurality of R ^21s may be the same or different from each other. Among them, at least one of R ^21s is a fluorine atom] [Chemistry 5] [In formula (A-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 greater than 1. A plurality of R ^3s may be the same or different from each other. A plurality of R ^41s may be the same or different from each other. Among them, at least one of R ^41s is a fluorine atom] [Chemistry 6] [In formula (A-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 greater than 0. A plurality of R ^61s may be the same or different from each other. A plurality of R ^62s may be the same or different from each other. Among them, at least one of R ^62s is a fluorine atom]

In one aspect, the monomer component may further include a monomer (B) other than the fluorine-containing monomer.

In one aspect, the monomer component may include a monomer (B-1) having a ring structure as the monomer (B).

In one aspect, the monomer (B-1) may include at least one selected from the group consisting of ethoxylated o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, and ethoxylated bisphenol A di(meth)acrylate.

In one aspect, the monomer component may include an alkanediol di(meth)acrylate (B-2) having an alkanediyl group having 6 or more carbon atoms as the monomer (B).

In one aspect, the alkanediol di(meth)acrylate (B-2) may include at least one selected from the group consisting of 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and 1,12-dodecanediol di(meth)acrylate.

In one aspect, the photopolymerization initiator may include an acylphosphine oxide type photopolymerization initiator.

Another aspect of the present invention is a hardened body formed by hardening the above-mentioned organic electroluminescent display element with a sealant. This hardened body has low moisture permeability and excellent adhesion to glass substrates, so it can be suitably used as a sealant for sealing the organic electroluminescent display element.

Another aspect of the present invention is a sealing material for an organic electroluminescent display element, which includes the above-mentioned hardened body. This sealing material has excellent moisture resistance and excellent adhesion to a glass substrate, etc. Therefore, according to the above-mentioned sealing material, an organic electroluminescent display device with excellent reliability and durability can be obtained.

Another aspect of the present invention is a sealing material for an organic electroluminescent display element, which includes a laminated body formed by laminating an inorganic film and an organic film. In the sealing material, the organic film includes the hardened body. According to this sealing material, a higher moisture resistance is achieved by combining the organic film including the hardened body and the inorganic film. In addition, since the hardened body has excellent adhesion to the glass substrate and the inorganic film, according to the sealing material, higher reliability and durability are achieved.

Another aspect of the present invention is an organic electroluminescent display device, which includes an organic electroluminescent display element and a sealing material for the organic electroluminescent display element. [Effect of the invention]

According to the present invention, there is provided a sealant for an organic EL display element which has excellent wettability with a glass substrate and can efficiently seal an organic EL display element. Also, according to the present invention, there is provided a sealant for an organic EL display element comprising a cured product of the sealant. Furthermore, according to the present invention, there is provided an organic EL display device comprising the sealant.

Hereinafter, the implementation forms of the present invention will be described in detail.

The sealant for an organic electroluminescent (EL) display element of the present embodiment (hereinafter also referred to as the sealant) contains: a monomer component including a fluorine-containing monomer having a fluorine atom and a (meth)acryl group (hereinafter also referred to as the (A) component); and a photopolymerization initiator.

The sealant of this embodiment has excellent wettability with glass substrates and other substrates with inorganic surfaces (glass substrates, resin substrates with inorganic films formed on them, etc.). Due to the excellent wettability of the sealant, the coating property becomes good, and the sealant diffuses on the substrate in a short time, thereby improving the working efficiency. In addition, due to the excellent wettability of the sealant, the flatness of the coating is improved, and a sealant with excellent flatness can be formed. In addition, according to the sealant of this embodiment, a sealant with excellent moisture resistance can be formed. Furthermore, the sealant formed by the sealant of this embodiment has excellent adhesion with glass substrates, substrates with inorganic films formed on them (glass substrates, resin substrates, etc.).

The reason for the above effect is not necessarily limited, but one of the reasons is considered to be that the fluorine-containing monomer reduces the surface free energy of the sealant, making it easier to follow fine irregularities, thereby improving the adhesion to the substrate and the like.

The fluorine-containing monomer has a fluorine atom and a (meth)acryl group. The (meth)acryl group represents an acryl group or a methacryl group. The fluorine-containing monomer may be used alone or in combination of two or more.

The number of fluorine atoms possessed by the fluorine-containing monomer only needs to be 1 or more, for example, 2 or more, preferably 3 or more. The upper limit of the number of fluorine atoms possessed by the fluorine-containing monomer is not particularly limited, for example, 40 or less, preferably 30 or less, and more preferably 25 or less.

The content of fluorine atoms relative to the total amount of the fluorine-containing monomer may be, for example, 1 mass % or more, preferably 2 mass % or more, and more preferably 5 mass % or more. In addition, the content of fluorine atoms, based on the total amount of the fluorine-containing monomer, may be, for example, 75 mass % or less, preferably 70 mass % or less, and more preferably 65 mass % or less.

The number of (meth)acryl groups possessed by the fluorinated monomer only needs to be 1 or more. From the viewpoint of easily obtaining a cured body with a lower glass transition temperature, the number of (meth)acryl groups possessed by the fluorinated monomer may be 1. Furthermore, from the viewpoint of easily obtaining a cured body with a higher glass transition temperature, the number of (meth)acryl groups possessed by the fluorinated monomer may be 2 or more. The upper limit of the number of (meth)acryl groups possessed by the fluorinated monomer is not particularly limited, and for example, it may be 4 or less. From the viewpoint of easily obtaining a cured body with excellent flexibility, it is preferably 3 or less, and more preferably 2 or less.

As one specific example of the fluorine-containing monomer, there can be mentioned a compound represented by formula (A-1).

[Chemistry 7]

In formula (A-1), ^R1 represents a hydrogen atom or a methyl group. Also, ^R2 represents a fluorinated alkyl group, or a group in which an oxygen atom is inserted into a portion of the carbon-carbon bond and the carbon-hydrogen bond of the fluorinated alkyl group.

The fluorinated alkyl group may be referred to as a group in which a part or all of the hydrogen atoms of the alkyl group are replaced by fluorine atoms. The number of carbon atoms of the fluorinated alkyl group is not particularly limited, and may be, for example, 1 or more, preferably 2 or more, and more preferably 3 or more. In addition, the number of carbon atoms of the fluorinated alkyl group may be, for example, 25 or less, or 20 or less.

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

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

The 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 (hereinafter also referred to as an oxygen-containing group of R ² ) may be a group in which an oxygen atom is inserted into one position, or may be a group in which an oxygen atom is inserted into two or more positions.

Furthermore, if an oxygen atom is inserted into a carbon-carbon bond, an ether bond is formed. Also, if an oxygen atom is inserted into a carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of ^R2 can also be referred to as a group containing at least one selected from the group consisting of an ether bond and a hydroxyl group.

As specific examples of the oxygen-containing group for R ² , for example, groups represented by the following formulas can be cited.

[Chemistry 8]

The fluorine atom content in the compound represented by formula (A-1) may be, for example, 2% by mass or more, preferably 5% by mass or more, more preferably 15% by mass or more, and further preferably 30% by mass or more. In addition, the fluorine atom content in the compound represented by formula (A-1) may be, for example, 75% by mass or less, preferably 70% by mass or less, and further preferably 65% by mass or less.

As one specific example of the compound represented by formula (A-1), for example, there can be mentioned a compound represented by formula (A-1-1).

[Chemistry 9]

In formula (A-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 greater than 1. A plurality of R ^21s may be the same or different from each other. At least one of R ^21s is a fluorine atom.

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

There are plural R ^21's in formula (A-1-1), at least one of which is a fluorine atom. Preferably, 2 or more R ^21's are fluorine atoms, more preferably 3 or more R 21's are fluorine atoms. All R ^21's 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. The ratio may be, for example, 100% or less, preferably 80% or less, and more preferably 75% or less.

The compound represented by formula (A-1-1) is preferably one in which at least one of the divalent groups (—C(R ²¹ ) ₂ —) in the parentheses attached to n is a difluoromethylene group (—CF ₂ —).

As another specific example of the fluorine-containing monomer, there can be mentioned a compound represented by formula (A-2).

[Chemistry 10]

In formula (A-2), R ³ represents a hydrogen atom or a methyl group. Also, 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 the carbon-hydrogen bond of the fluorinated alkanediyl group. A plurality of R ³ groups may be the same or different.

The fluorinated alkanediyl group may be referred to as a group in which a part or all of the hydrogen atoms of the alkanediyl group are replaced by 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 further 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 a difluoromethylene group (—CF ₂ —) can be suitably used.

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

The 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 (hereinafter also referred to as an oxygen-containing group of R ⁴ ) may be a group in which an oxygen atom is inserted into one position or may be a group in which an oxygen atom is inserted into two or more positions.

Furthermore, if an oxygen atom is inserted into a carbon-carbon bond, an ether bond is formed. Also, if an oxygen atom is inserted into a carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of ^R4 can also be referred to as a group containing at least one selected from the group consisting of an ether bond and a hydroxyl group.

As specific examples of the oxygen-containing group for R ⁴ , for example, groups represented by the following formulas can be cited.

[Chemistry 11]

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

As one specific example of the compound represented by formula (A-2), for example, there can be mentioned a compound represented by formula (A-2-1).

[Chemistry 12]

In formula (A-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 greater than 1. A plurality of R ^3s may be the same or different from each other. A plurality of R ^41s may be the same or different from each other. At least one of R ^41s is a fluorine atom.

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

There are plural R ^41's in formula (A-2-1), at least one of which is a fluorine atom. Preferably, 2 or more R ^41's are fluorine atoms, more preferably 4 or more R 41's are fluorine atoms. All R ^41's 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, more preferably 10% or more. The ratio may be, for example, 100% or less, preferably 95% or less, more preferably 90% or less.

In the compound represented by the formula (A-2-1), at least one of the divalent groups (—C(R ⁴¹ ) ₂ —) in the parentheses attached to m is preferably a difluoromethylene group (—CF ₂ —).

As another specific example of the fluorine-containing monomer, there can be mentioned a compound represented by formula (A-3).

[Chemistry 13]

In formula (A-3), R ⁵ represents a hydrogen atom or a methyl group. Also, 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 the carbon-hydrogen bond in the alkanediyl group or the fluorinated alkanediyl group. Also, Ar ¹ represents a fluorinated aryl group.

Furthermore, the phrase "R ⁶ represents a single bond" means that Ar ¹ is directly bonded to the oxygen atom.

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

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

Specific examples of the alkanediyl group include a linear or branched alkanediyl group having 1 to 17 carbon atoms (e.g., a methylene group, an ethylene group, etc.), a cycloalkanediyl group having 1 to 17 carbon atoms, and the like.

The fluorinated alkanediyl group of R ⁶ can be referred to as a group in which a part or all of the hydrogen atoms of the above-mentioned alkanediyl group are replaced by fluorine atoms. The number of carbon atoms of the fluorinated alkanediyl group of R ⁶ is not particularly limited, and can be, for example, 1 or more. In addition, the number of carbon atoms of the fluorinated alkanediyl group of R ⁶ can 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 a difluoromethylene group (—CF ₂ —) can be suitably used.

The 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 the 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 or may be a group in which an oxygen atom is inserted at two or more positions.

Furthermore, if an oxygen atom is inserted into a carbon-carbon bond, an ether bond is formed. Also, if an oxygen atom is inserted into a carbon-hydrogen bond, a hydroxyl group is formed. That is, the oxygen-containing group of R ⁶ can also be referred to as a group containing at least one selected from the group consisting of an ether bond and a hydroxyl group.

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

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

As one specific example of the compound represented by formula (A-3), for example, there can be mentioned a compound represented by formula (A-3-1).

[Chemistry 14]

In formula (A-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 greater than or equal to 0. When p is greater than or equal to 1, a plurality of R ^61s may be the same or different from each other. In addition, a plurality of R ^62s may be the same or different from each other. Among them, at least one of R ^62s is a fluorine atom.

p represents an integer greater than or equal to 0. Here, p being 0 indicates that the benzene ring and the oxygen atom are directly bonded. p may be an integer greater than or equal to 1. 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 (A-3-1) (ie, when p is an integer greater than or equal to 1), all R ⁶¹ may be hydrogen atoms, all may be fluorine atoms, or a part may be hydrogen atoms and the other part may be fluorine atoms.

There are plural R ⁶² in formula (A-3-1), at least one of which is a fluorine atom. Moreover, two or more R ⁶² may be fluorine atoms, or three or more R 62 may be fluorine atoms. Moreover, all (5) 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, more preferably 20% or more. The ratio may be, for example, 100% or less, preferably 95% or less, more preferably 80% or less.

The fluorine-containing monomers are not limited to the above compounds.

The sealant of this embodiment may further contain other monomer components (hereinafter, also referred to as component (B)) in addition to the fluorinated monomer. Component (B) may be any compound that can copolymerize with the fluorinated monomer (component (A)), for example, a compound having a polymerizable group that can copolymerize with a (meth)acryloyl group.

Examples of the polymerizable group possessed by the component (B) include a vinyl group, a (meth)acryl group, an allyl group, a vinyl ether group, a vinyl ester group, and the like. Among these, a (meth)acryl group is preferred.

As the component (B), a monomer having a (meth)acryl group can be suitably used. That is, the component (B) is preferably a monomer having no fluorine atom and having a (meth)acryl group.

Examples of the component (B) include monofunctional (meth)acrylates such as ethyl (meth)acrylate, butyl (meth)acrylate, benzyl (meth)acrylate, and ethoxylated o-phenylphenol acrylate; and polyfunctional (meth)acrylates such as 1,6-hexanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, and dihydroxymethyltricyclodecane di(meth)acrylate.

As a suitable example of the component (B), a monomer having a cyclic structure (hereinafter, also referred to as the component (B-1)) can be cited. Examples of the cyclic structure possessed by the component (B-1) include: heterocyclic rings such as cyclic amide, tetrahydrofuran ring, piperidine ring, etc.; aliphatic hydrocarbon rings such as cyclopentane ring, cyclohexane ring, cyclohexene ring, cyclododecatriene ring, norethane ring, and adamantane ring; and aromatic hydrocarbon rings such as benzene ring. Among them, at least one selected from the group consisting of aliphatic hydrocarbon rings and aromatic hydrocarbon rings is preferred. Furthermore, the component (B-1) does not have a fluorine atom, and is distinguished from the above-mentioned fluorine-containing monomers.

In the component (B-1), monomers having an aromatic hydrocarbon ring include: benzyl (meth)acrylate, 4-butylphenyl (meth)acrylate, phenyl (meth)acrylate, 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)acryloyloxyethyl 2-hydroxypropylphthalate, EO (Ethylene Oxide, ethylene oxide) modified phenol (meth) acrylate, EO (ethylene oxide) modified cresol (meth) acrylate, EO modified nonylphenol (meth) acrylate, PO (propylene oxide) modified nonylphenol (meth) acrylate, ethoxylated o-phenylphenol (meth) acrylate, m-phenoxybenzyl (meth) acrylate and other monofunctional monomers; ethoxylated bisphenol A di(meth) acrylate, propoxylated bisphenol A di(meth) acrylate, propoxylated ethoxylated bisphenol A di(meth) acrylate, bisphenol A epoxy di(meth) acrylate and other multifunctional monomers.

The monomer having an aromatic hydrocarbon ring is preferably a monomer having two benzene rings. Examples of such monomers include ethoxylated o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, and ethoxylated bisphenol A di(meth)acrylate. It is particularly preferred to be at least one selected from the group consisting of ethoxylated o-phenylphenol (meth)acrylate and ethoxylated bisphenol A di(meth)acrylate.

As the ethoxylated o-phenylphenol (meth)acrylate, for example, a compound represented by the following formula (B-1-1) is preferred.

[Chemistry 15]

In formula (B-1-1), q represents an integer greater than or equal to 1 (preferably 1 to 5), and ^R7 represents a hydrogen atom or a methyl group.

As the ethoxylated bisphenol A di(meth)acrylate, for example, a compound represented by the following formula (B-1-2) is preferred.

[Chemistry 16]

In formula (B-1-2), r and s each independently represent an integer greater than 1 (preferably r+s=2 to 10), and R ⁸ and R ⁹ each independently represent a hydrogen atom or a methyl group.

In the component (B-1), examples of the monomer having an aliphatic hydrocarbon ring include cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, isobutylene (meth)acrylate, methoxylated cyclodecatriene (meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, and 2-(meth)acryloyloxyethyl hexahydrophthalate.

The monomer having an aliphatic hydrocarbon ring is preferably a monomer having at least one selected from the group consisting of a isocyanate ring and a cyclopentane ring. Examples of such monomers include tricyclodecanedimethanol di(meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate. Particularly preferred is at least one selected from the group consisting of dicyclopentyl (meth)acrylate and tricyclodecanedimethanol di(meth)acrylate.

From the viewpoint of easily obtaining a sealing material having a low moisture permeability and being more excellent, the component (B-1) is preferably a monomer having two or more ring structures in the molecule, and more preferably a monomer having two ring structures in the molecule.

Examples of monomers having two or more ring structures in the molecule include: Monomers having aromatic hydrocarbon rings selected from the group consisting of ethoxylated o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, and ethoxylated bisphenol A di(meth)acrylate; Monomers having aliphatic hydrocarbon rings such as tricyclodecane dimethanol di(meth)acrylate, dicyclopentyloxyethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate.

From the viewpoint of easily obtaining a sealing material with a lower moisture permeability and better performance, the component (B-1) is preferably selected from the group consisting of ethoxylated o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, tricyclodecanedimethanol di(meth)acrylate and ethoxylated bisphenol A di(meth)acrylate.

As another suitable example of the component (B), there can be cited an alkanediol di(meth)acrylate having an alkanediyl group having 6 or more carbon atoms (hereinafter, also referred to as the component (B-2)). The carbon number of the alkanediyl group possessed by the component (B-2) is preferably 1 to 20, more preferably 6 to 15, and further preferably 9 to 12. Furthermore, the alkanediyl group possessed by the component (B-2) is preferably an α,ω-alkanediyl group. Furthermore, the component (B-2) does not have a fluorine atom, and is distinguished from the above-mentioned fluorine-containing monomer.

Component (B-2) includes, for example, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, etc. Preferably, it is at least one selected from the group consisting of 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, and 1,12-dodecanediol di(meth)acrylate, and more preferably, it is 1,12-dodecanediol di(meth)acrylate.

In this embodiment, the ratio of the fluorine-containing monomer to the total monomer components is preferably 3 mass % or more, more preferably 5 mass % or more, and further preferably 10 mass % or more. The upper limit of the ratio is not particularly limited, and may be, for example, 100 mass %.

Regarding the fluorine atom content relative to the total amount of the monomer components, from the viewpoint of wettability and adhesion, it can be, for example, 0.1 mass % or more, preferably 0.3 mass % or more, more preferably 1 mass % or more, further preferably 2 mass % or more, and most preferably 5 mass % or more. In addition, regarding the fluorine atom content, based on the total amount of the monomer components, it can be, for example, 75 mass % or less, preferably 70 mass % or less, and more preferably 65 mass % or less.

The photopolymerization initiator may be any compound that can be activated by active light such as visible light or ultraviolet light and can start or promote the monomer component containing the fluorine-containing monomer. The photopolymerization initiator may be used alone or in combination of two or more. As the photopolymerization initiator, a photoradical polymerization initiator is preferred.

As the photo-free radical polymerization initiator, there can be listed: benzophenone and its derivatives; benzoyl and its derivatives; anthraquinone and its derivatives; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, benzoyl dimethyl ketal and other benzoin-type photopolymerization initiators; diethoxyacetophenone, 4-tert-butyltrichloroacetophenone and other acetophenone-type photopolymerization initiators; 2-dimethylaminoethyl benzoate; p-dimethylaminoethyl benzoate; diphenyl disulfide; 9-oxysulfide and its derivatives; camphorquinone type photopolymerization initiators such as 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, and 7,7-dimethyl-2,3-dioxobicyclo[2.2.1]heptane-1-carboxylic acid chloride; α-aminoalkylphenone type photopolymerization initiators such as 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one and 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1; Acylphosphine oxide type photopolymerization initiators such as benzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoyldiethoxyphosphine oxide, 2,4,6-trimethylbenzoyldimethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiethoxyphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; Methyl phenylglyoxylate; 2-[2-oxo-2-phenyl-acetyloxy-ethoxy]ethyl hydroxy-phenyl-acetate; Hydroxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]ethyl ester, etc.

As a photopolymerization initiator, from the viewpoint that curing can be performed using only visible light above 390 nm, an acylphosphine oxide type photopolymerization initiator is preferred. Furthermore, an acylphosphine oxide type photopolymerization initiator can also be referred to as a photopolymerization initiator having an acylphosphine oxide group (-(C=O)-(P=O)＜). Moreover, from the viewpoint that curing can be performed using light above 395 nm, and a cured body with a higher visible light transmittance can be easily obtained, 2,4,6-trimethylbenzyldiphenylphosphine oxide is particularly preferred. As 2,4,6-trimethylbenzyldiphenylphosphine oxide, for example, "Irgacure TPO" manufactured by BASF Japan can be cited.

The content of the photopolymerization initiator is preferably 0.05 parts by mass or more, more preferably 0.5 parts by mass or more, further preferably 2 parts by mass or more, and further preferably 2.5 parts by mass or more, relative to 100 parts by mass of the total amount of the monomer components. By increasing the content of the photopolymerization initiator, the curing performance of the sealant tends to be further improved. The content of the photopolymerization initiator is preferably 12 parts by mass or less, more preferably 8 parts by mass or less, and further preferably 6 parts by mass or less, relative to 100 parts by mass of the total amount of the monomer components. By reducing the content of the photopolymerization initiator, it is easy to obtain a cured body with a higher visible light transmittance.

The sealant of the present embodiment may further contain other components besides the monomer component and the photopolymerization initiator. The sealant of the present embodiment may further contain, for example, known additives used in the art as other components. Examples of additives include antioxidants, metal deactivators, fillers, stabilizers, neutralizers, lubricants, antibacterial agents, and the like.

The surface tension, especially the static surface tension, of the sealant of this embodiment is preferably 40 mN/m or less, and more preferably 30 mN/m or less. This makes it easier to apply the sealant by inkjet, etc., and improves workability. In addition, this improves adhesion to substrates, etc., and tends to further improve moisture resistance and adhesion. The lower limit of the static surface tension is not particularly limited, and may be, for example, 10 mN/m or more.

Furthermore, static surface tension is measured by the plate method, ring method, pendant drop method, etc. The static surface tension value specified in this embodiment is based on the pendant drop method. The so-called pendant drop method refers to a method of squeezing liquid out of the front end of a tube and calculating the surface tension based on the shape of the pendant drop.

The sealant of this embodiment can be cured by irradiating at least one of visible light or ultraviolet light. In addition, in this specification, the so-called "curing" of the sealant is not necessarily limited to rigid curing, as long as the monomer components are polymerized to form a polymer. For example, the cured body of the sealant can be a rigid solid (such as glass) or a rubber.

Examples of energy irradiation sources for irradiating visible light or ultraviolet light include: deuterium lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps, xenon lamps, xenon-mercury mixed lamps, halogen lamps, excimer lamps, indium lamps, cobalt lamps, LED (Light Emitting Diode) lamps, electrodeless discharge lamps, and the like.

From the viewpoint of not easily damaging the organic EL display element, the sealant of this embodiment is preferably cured by light with a wavelength of 380 nm or more, more preferably by light with a wavelength of 395 nm or more, and most preferably by light with a wavelength of 395 nm. As for the wavelength of the irradiated light, it is preferably 500 nm or less in order to avoid the temperature rise of the irradiated part caused by infrared light and to reduce the possibility of damaging the organic EL display element. As the energy irradiation source, it is preferably an LED lamp with a single wavelength of light emission.

The irradiation dose when curing the sealant is preferably 100 to 8000 mJ/cm ² , more preferably 300 to 2000 mJ/cm ² . By setting the irradiation dose to 100 mJ/cm ² or more, the sealant is sufficiently cured and a high bonding strength is easily obtained. By setting the irradiation dose to 8000 mJ/cm ² or less, the sealant can be cured without causing damage to the organic EL display element.

The cured sealant of this embodiment is preferably excellent in transparency. Specifically, the spectral transmittance of the cured sealant in the ultraviolet-visible light range of 360 nm to 800 nm is preferably 95% or more per 10 μm of thickness, more preferably 97% or more, and further preferably 99% or more. If the spectral transmittance is 95% or more, it is easy to obtain an organic EL display device with excellent brightness and contrast.

The moisture permeability of the cured sealant of this embodiment is preferably 350 g/m ² or less, more preferably 150 g/m 2 or less, and further preferably 75 g/m ² or ^less , at a thickness of 100 μm, measured in an environment of 23°C and 90% RH for 24 hours in accordance with JIS Z 0208:1976. If the moisture permeability is lower, the generation of dark spots caused by moisture reaching the organic light-emitting material layer can be suppressed.

The method of using the sealant of this embodiment is not particularly limited. For example, by applying the sealant on an object (such as an organic EL display element) and curing the sealant on the object, a sealant including a cured body of the sealant can be formed.

Furthermore, the sealant can be cured in a specific shape (e.g., film, sheet, etc.) to form a sealant having a specific shape. In this case, for example, the organic EL display element can be sealed by placing the sealant on the organic EL display element.

Hereinafter, an organic EL display device formed by using the sealant of the present embodiment will be described by taking a top-emission type organic EL display device as an example. Furthermore, the organic EL display device to which the sealant of the present embodiment is applied is not limited to the top-emission type, and may also be a bottom-emission type organic EL display device in which light generated in the organic EL layer is irradiated from the substrate side.

A top-emitting organic EL display device includes: an organic EL display element; a sealing layer that seals the organic EL display element; and a sealing substrate that is disposed on the sealing layer.

An organic EL display element has, for example, a structure in which an anode, an organic EL layer including a light-emitting layer, and a cathode are sequentially stacked on a substrate.

As the substrate of the organic EL display element, for example, there can be listed: a glass substrate, a silicon substrate, a plastic substrate, etc. Among them, at least one selected from the group consisting of a glass substrate and a plastic substrate is preferred, and a glass substrate is more preferred.

Examples of plastics used for plastic substrates include polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, polyoxadiazole, aromatic polyamide, polybenzimidazole, polybenzobisthiazole, polybenzoxazole, polythiazole, polyphenylene vinylene, polymethyl methacrylate, polystyrene, polycarbonate, polycycloolefin, polyacrylic acid, and the like. Among them, in terms of low water permeability, low oxygen permeability, and excellent heat resistance, preferably one or more of the group consisting of polyimide, polyetherimide, polyethylene terephthalate, polyethylene naphthalate, polyoxadiazole, aromatic polyamide, polybenzimidazole, polybenzobisthiazole, polybenzoxazole, polythiazole, and polyphenylene vinylene are used. In terms of high permeability to energy rays such as ultraviolet rays or visible light, more preferably one or more of the group consisting of polyimide, polyetherimide, polyethylene terephthalate, and polyethylene naphthalate are used.

As the anode, a conductive metal oxide film or a semi-transparent metal film with a relatively large work function (preferably a work function greater than 4.0 eV) is usually used. Examples of materials for the anode include: metal oxides such as indium tin oxide (hereinafter referred to as ITO), tin oxide, metals such as gold (Au), platinum (Pt), silver (Ag), copper (Cu), or alloys containing at least one of these, organic transparent conductive films such as polyaniline or its derivatives, polythiophene or its derivatives, etc. The anode can be formed using a layer structure of two or more layers as needed. The film thickness of the anode can be appropriately selected in consideration of conductivity (in the case of bottom-emitting type, the light transmittance is also considered). The 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. The anode can be made by vacuum evaporation, sputtering, ion plating, coating, etc. In the case of top emission, a reflective film for reflecting light irradiated to the substrate side can be placed under the anode.

The organic EL layer at least includes a light-emitting layer containing an organic substance. The light-emitting layer contains a light-emitting material. Examples of the light-emitting material include organic substances (low molecular weight compounds or high molecular weight compounds) that emit fluorescence or phosphorescence. The light-emitting layer may further contain a dopant material. Examples of the organic substance include: pigment materials, metal complex materials, high molecular weight materials, etc. The dopant material is doped into the organic substance in order to improve the light-emitting efficiency of the organic substance or change the light-emitting wavelength. The thickness of the light-emitting layer including the organic substance and the dopant doped as needed is usually 2 to 200 nm.

Examples of pigment materials include cyclopentamine derivatives, tetraphenylbutadiene derivatives, triphenylamine derivatives, oxadiazole derivatives, pyrazoloquinoline derivatives, distyrylbenzene derivatives, distyryl aromatic hydrocarbon derivatives, pyrrole derivatives, thiophene ring compounds, pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, tris(2-butylene)diamide derivatives, oxadiazole dimers, pyrazoline dimers, and the like.

Examples of metal complex materials include iridium complexes, platinum complexes, and other metal complexes that emit light from a triplet excited state, hydroxyquinoline aluminum complexes, hydroxybenzoquinoline beryllium complexes, benzoxazole zinc complexes, benzothiazole zinc complexes, azomethyl zinc complexes, porphyrin zinc complexes, and cerium complexes. Examples of metal complexes include rare earth metals such as zirconium (Tb), chalcohol (Eu), and dysprosium (Dy), aluminum (Al), zinc (Zn), and benzene (Be), and ligands having structures such as oxadiazole, thiadiazole, phenylpyridine, phenylbenzimidazole, and quinoline. Among these, preferred are metal complexes having aluminum (Al) as the central metal and quinoline structures as the ligand. Among metal complexes having aluminum (Al) as the central metal and quinoline structures as the ligand, tris(8-hydroxyquinolinyl)aluminum is preferred.

Examples of the polymer material include poly(p-phenylene vinylene) derivatives, polythiophene derivatives, poly(p-phenylene) derivatives, polysilane derivatives, polyacetylene derivatives, polyfluorene derivatives, polyvinylcarbazole derivatives, and polymerized products of the above-mentioned pigments or metal complex-based luminescent materials.

Among the above-mentioned luminescent materials, materials emitting blue light include distyrylarene derivatives, oxadiazole derivatives, polyvinylcarbazole derivatives, poly(p-phenylene) derivatives, polyfluorene derivatives, and polymers thereof. Among them, polymer materials are preferred. Among polymer materials, one or more of the group consisting of polyvinylcarbazole derivatives, poly(p-phenylene) derivatives, and polyfluorene derivatives are preferred.

Materials that emit green light include quinacridone derivatives, coumarin derivatives, poly(p-phenylene vinylene) derivatives, polyfluorene derivatives, and polymers thereof. Among these, polymer materials are preferred. Among polymer materials, one or more of the group consisting of poly(p-phenylene vinylene) derivatives and polyfluorene derivatives are preferred.

Materials that emit red light include coumarin derivatives, thiophene ring compounds, poly(p-phenylene vinylene) derivatives, polythiophene derivatives, polyfluorene derivatives, and polymers thereof. Among these, polymer materials are preferred. Among polymer materials, one or more of the group consisting of poly(p-phenylene vinylene) derivatives, polythiophene derivatives, and polyfluorene derivatives are preferred.

As doping materials, there can be listed: perylene derivatives, coumarin derivatives, erythrofluorene derivatives, quinacridone derivatives, squarylium derivatives, porphyrin derivatives, styrene pigments, tetraphenylene derivatives, pyrazolone derivatives, decacyclic ene, phenanthene, etc.

In addition to the light-emitting layer, the organic EL layer may be appropriately provided with a layer provided between the light-emitting layer and the anode, and a layer provided between the light-emitting layer and the cathode. First, as a layer provided between the light-emitting layer and the anode, a hole injection layer that improves the hole injection efficiency of injecting holes from the anode, or a hole transport layer that transports holes injected from the anode or the hole injection layer to the light-emitting layer, etc. may be cited. As a layer provided between the light-emitting layer and the cathode, an electron injection layer that improves the electron injection efficiency of injecting electrons from the cathode, or an electron transport layer that transports electrons injected from the cathode or the electron injection layer to the light-emitting layer, etc. may be cited.

Materials for forming the hole injection layer include phenylamines such as 4',4''-tri{2-naphthyl(phenyl)amino}triphenylamine, starburst amines, phthalocyanines, oxides such as vanadium oxide, molybdenum oxide, ruthenium oxide, aluminum oxide, amorphous carbon, polyaniline, polythiophene derivatives, and the like.

Examples of materials for forming the hole transport layer include polyvinyl carbazole or its derivatives, polysilane or its derivatives, polysiloxane derivatives having aromatic amines in the side chains or main chains, pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine derivatives, benzidine derivatives, polyaniline or its derivatives, polythiophene or its derivatives, polyarylamine or its derivatives, polypyrrole or its derivatives, poly(p-phenylene vinylene) or its derivatives, poly(2,5-thiophene acetylene) or its derivatives, and the like.

When the hole injection layer or the hole transport layer has the function of blocking the transport of electrons, it is sometimes called an electron blocking layer.

As materials constituting the electron transport layer, there can be listed: diazole derivatives, anthraquinone dimethane or its derivatives, benzoquinone or its derivatives, naphthoquinone or its derivatives, anthraquinone or its derivatives, tetracyanoanthraquinone dimethane or its derivatives, fluorenone derivatives, diphenyl dicyanoethylene or its derivatives, diphenoquinone derivatives, 8-hydroxyquinoline or its derivatives, polyquinoline or its derivatives, polyfluorene or its derivatives, etc. As derivatives, there can be listed metal complexes, etc. Among them, 8-hydroxyquinoline or its derivatives are preferred. Among 8-hydroxyquinoline or its derivatives, tris(8-hydroxyquinolyl)aluminum is preferred in terms of being also used as an organic substance emitting fluorescence or phosphorescence contained in the light-emitting layer.

As the electron injection layer, depending on the type of the light-emitting layer, there can be exemplified an electron injection layer having a single layer structure including a calcium (Ca) layer; or an electron injection layer having a single layer structure including a layer formed of one or more metals selected from the group consisting of metals of Group IA and Group IIA of the periodic table with a work function of 1.5 to 3.0 eV and oxides, halides and carbonates of the metals; or an electron injection layer having a layer formed of one or more metals selected from the group consisting of metals of Group IA and Group IIA of the periodic table with a work function of 1.5 to 3.0 eV and oxides, halides and carbonates of the metals and a Ca layer. Examples of metals of Group IA of the periodic table with a work function of 1.5 to 3.0 eV or their oxides, halides, and carbonates include lithium (Li), lithium fluoride, sodium oxide, lithium oxide, and lithium carbonate. Examples of 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 the electron transport layers or electron injection layers have the function of blocking the transport of holes, the electron transport layers or electron injection layers are sometimes referred to as hole blocking layers.

As the cathode, it is preferred to use a transparent or semi-transparent material with a relatively small work function (preferably a work function of less than 4.0 eV) and easy to inject electrons into the light-emitting layer. Examples of cathode materials include lithium (Li), sodium (Na), potassium (K), rhodium (Rb), cesium (Cs), curium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), aluminum (Al), stygium (Sc), vanadium (V), zinc (Zn), yttrium (Y), indium (In), thorium (Ce), samarium (Sm), eutectic (Eu), terbium (Tb), and ytterbium (Yb). Metal; or alloys containing two or more of the above metals; or alloys containing one or more of the above metals and one or more of gold (Au), silver (Ag), platinum (Pt), copper (Cu), chromium (Cr), manganese (Mn), titanium (Ti), cobalt (Co), nickel (Ni), tungsten (W), tin (Sn); or graphite or graphite intercalation compounds; or metal oxides such as ITO and tin oxide, etc.

The cathode may be a laminated structure of more than two layers. Examples of laminated structures of more than two layers include the above-mentioned metals, metal oxides, fluorides, alloys thereof, and laminated structures of metals such as Al, Ag, and Cr. The film thickness of the cathode may be appropriately selected in consideration of conductivity or durability. The film thickness of the cathode is preferably 10 nm to 10 μm, more preferably 15 nm to 1 μm, and most preferably 20 nm to 500 nm. Examples of cathode manufacturing methods include vacuum evaporation, sputtering, and lamination by hot pressing a metal film.

The layers provided between the light-emitting layer and the anode, and between the light-emitting layer and the cathode can be appropriately selected according to the performance required of the organic EL display device to be manufactured. For example, the structure of the organic EL display element used in this embodiment can have any of the following layer structures (i) to (xv). (i) Anode/hole transport layer/luminescent layer/cathode (ii) Anode/luminescent layer/electron transport layer/cathode (iii) Anode/hole transport layer/luminescent layer/electron transport layer/cathode (iv) Anode/hole injection layer/luminescent layer/cathode (v) Anode/luminescent layer/electron injection layer/cathode (v i) Anode/hole injection layer/luminescent layer/electron injection layer/cathode (vii) Anode/hole injection layer/hole transport layer/luminescent layer/cathode (viii) Anode/hole transport layer/luminescent layer/electron injection layer/cathode (ix) Anode/hole injection layer/hole transport layer/luminescent layer/electron injection layer / cathode (x) anode/hole injection layer/luminescent layer/electron transport layer/cathode (xi) anode/luminescent layer/electron transport layer/electron injection layer/cathode (xii) anode/hole injection layer/luminescent layer/electron transport layer/electron injection layer/cathode (xiii) anode/hole injection layer/hole transport layer Layer/luminescent layer/electron transport layer/cathode (xiv)Anode/hole transport layer/luminescent layer/electron transport layer/electron injection layer/cathode (xv)Anode/hole injection layer/hole transport layer/luminescent layer/electron transport layer/electron injection layer/cathode (Here, "/" means that each layer is stacked adjacent to each other. Same below)

The purpose of setting up the sealing layer is to prevent water vapor, oxygen and other gases from contacting the organic EL display element and to seal the organic EL display element with a layer having a high barrier property to the above gases. The sealing layer alternately forms inorganic films and organic films from the bottom. The inorganic/organic laminate can be formed by repeating it more than 2 times.

The inorganic film of the inorganic/organic laminate is a film provided to prevent the organic EL display element from being exposed to gases such as water vapor or oxygen in the environment of the organic EL display device. The inorganic film of the inorganic/organic laminate _is preferably a continuous and dense film with fewer defects such as pinholes. Examples of the inorganic film include single component films such as SiN films, SiO films, SiON films, _Al2O3 films, AlN films, or laminated films thereof.

The organic film of the inorganic/organic laminate is provided to cover defects such as pinholes formed on the inorganic film, and is provided to give flatness to the surface. The organic film is formed in a narrower area than the area where the inorganic film is formed. The reason is that if the organic film is formed in the same area as or wider than the area where the inorganic film is formed, the organic film deteriorates in the exposed area. However, the uppermost organic film formed on the uppermost layer of the entire sealing layer is formed in an area roughly the same as the area where the inorganic film is formed. And, it is formed in a manner that flattens the upper surface of the sealing layer. The organic film can be a film formed using the sealant of the above-mentioned embodiment (that is, a film containing a hardened body of the sealant).

The sealant of this embodiment is suitable for, for example, inkjet coating, which can coat a film with a thickness of 3 μm or more with excellent flatness in a short time, and the inkjet has excellent sprayability and excellent flatness after inkjet coating. If a coating method using the inkjet method is used, an organic film can be formed at high speed and uniformly.

If the sealing layer counts the inorganic/organic multilayer as 1 group, it is preferably 1 to 5 groups. The reason is that when the inorganic/organic multilayer is 6 or more groups, the sealing effect on the organic EL display element is roughly the same as that in the case of 5 groups. The thickness of the inorganic film of the inorganic/organic multilayer is preferably 50 nm to 1 μm. The thickness of the organic film of the inorganic/organic multilayer is preferably 1 to 15 μm, and more preferably 3 to 10 μm. If the thickness of the organic film is 1 μm or more, it can completely cover the particles generated when the element is formed, and can form a film on the inorganic film with good flatness. If the thickness of the organic film is 15 μm or less, it inhibits the penetration of moisture from the side of the organic film, thereby improving the reliability of the organic EL display element.

The sealing substrate is formed in a manner of covering the entire upper surface of the uppermost organic film of the sealing layer. As the sealing substrate, the above-mentioned substrates can be cited. Among them, a substrate transparent to visible light is preferred. Among the substrates transparent to visible light (transparent sealing substrates), one or more of the group consisting of a glass substrate and a plastic substrate is preferred, and a glass substrate is more preferred.

The thickness of the transparent sealing substrate is preferably 1 μm to 1 mm, more preferably 10 μm to 800 μm, and most preferably 50 μm to 300 μm. By placing the transparent sealing substrate above the sealing layer, the degradation of the surface of the top organic film when it comes into contact with gas can be suppressed, and the barrier property of the organic EL display device can be improved.

Next, a method for manufacturing an organic EL display device having such a structure is described. First, an anode patterned in a specific shape, an organic EL layer including a light-emitting layer, and a cathode are sequentially formed on a first substrate by a previously known method to form an organic EL display element. For example, when the organic EL display device is used as a dot matrix display device, a contact array is formed to divide the light-emitting area into a matrix shape, and the organic EL layer including the light-emitting layer is formed in the area surrounded by the contact array.

Next, a first inorganic film having a specific thickness is formed on a substrate on which an organic EL display element 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. Thereafter, a film forming method such as a solution coating method or a spray coating method, or a flash evaporation method, an inkjet method, etc. is used to attach the sealant of the present embodiment to the first inorganic film. Among these, the inkjet method is preferred in terms of productivity. Thereafter, the sealant is hardened by irradiation with energy rays such as ultraviolet rays and visible light, thereby forming the first organic film. Through the above steps, an inorganic/organic laminate is formed. The curing rate of the sealant is not particularly limited as long as it can exert the effect of the present embodiment. For example, it can be set to 80% or more, preferably 90% or more, and more preferably 95% or more according to the value obtained by the following measurement method.

The above-mentioned steps of forming the inorganic/organic multilayer are repeated only for a specific number of times. For the last group, i.e., the top inorganic/organic multilayer, the sealing agent can be attached to the upper surface of the inorganic film by coating, flash evaporation, inkjet, etc. to flatten the surface.

Next, a transparent sealing substrate is attached to the surface of the substrate to which the sealing agent is attached. Alignment is performed during the attachment. Thereafter, the sealing agent of this embodiment between the uppermost inorganic film and the transparent sealing substrate is hardened by irradiating energy rays from the side of the transparent sealing substrate. Thus, the sealing agent is hardened to form the uppermost organic film, and the uppermost organic film is bonded to the transparent sealing substrate. With the above, the manufacturing method of the organic EL display device is completed.

After the sealant is attached to the inorganic film, it can be partially irradiated with energy rays to polymerize it. This can prevent the shape of the uppermost organic film from being deformed when the transparent sealing substrate is mounted. The thickness of the inorganic film and the organic film can be the same in each inorganic/organic laminate or different in each inorganic/organic laminate.

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

The above describes suitable implementation forms of the present invention, but the present invention is not limited to the above implementation forms. Implementation Examples

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the examples.

(Example 1) 100 parts by mass of trifluoromethyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 5 parts by mass of 2,4,6-trimethylbenzyldiphenylphosphine oxide (TPO) (manufactured by BASF Japan) were mixed to prepare a sealant. The content of fluorine atoms relative to the total amount of monomer components was 32% by mass. The obtained sealant was evaluated by the evaluation method shown below. Furthermore, the obtained sealant was cured under the light curing conditions shown below to form a cured body, and the moisture permeability of the cured body was evaluated by the method shown below.

[Surface tension] The static surface tension of the sealant was measured by the hanging drop method using (DM500 manufactured by Kyowa Interface Science Co., Ltd.) in an atmosphere of 23°C. The measurement results are shown in Table 1.

[Wettability] On a 70 mm×70 mm×0.7 mmt substrate (alkaline-free glass (Eagle XG manufactured by Corning)), 25 μm×25 μm×3 μmt depressions were made by etching at intervals of 10 μm in the front, back, left and right directions. In addition, the substrate was cleaned with acetone and isopropyl alcohol before use, and then cleaned for 5 minutes using UV (Ultra Violet) ozone cleaning device UV-208 manufactured by TECHNOVISION. Then, a 200 nm SiN film was formed on the substrate with the depressions by plasma CVD. Next, the sealant was applied in a pattern using an inkjet device (MID500B manufactured by Musashi Engineering, solvent-based inkjet head "MID inkjet head") to form a 50 mm × 50 mm × 10 μmt area. After the pattern was applied, it was placed at a temperature of 23°C and a relative humidity of 50% for 5 minutes, and the shape of the sealant in the applied area (50 mm × 50 mm) was observed. The wettability of the sealant was calculated using the following formula. The results are shown in Table 1. Wettability (%) = (area of sealant in the coated area after 5 minutes) / (50 mm × 50 mm) Furthermore, for example, the so-called 50% wettability means that part of the pattern-coated sealant is not wetted, and the SiN film is exposed in half (50%) of the 50 mm × 50 mm range.

[Tensile shear bonding strength] The test was conducted in accordance with JIS K 6850. Specifically, heat-resistant glass (trade name "heat-resistant Pyrex (registered trademark) glass", length 25 mm × width 25 mm × thickness 2.0 mm) was used as the bonded material, the bonding portion was set to a circular shape with a diameter of 8 mm, and two sheets of heat-resistant glass were bonded together using a sealant in such a way that the thickness of the sealing layer became 0.08 mm. Then, using an LED lamp emitting a wavelength of 395 nm (UV-LED LIGHT SOURCE H-4MLH200-V1 manufactured by HOYA), light was irradiated from the upper surface under the condition that the cumulative light amount of light with a wavelength of 395 nm became 1,500 mJ/ ^cm2 , and it was cured to produce a tensile shear bonding strength test piece. The tensile shear strength of the prepared specimens was measured using a universal testing machine at a temperature of 23°C and a humidity of 50% at a tensile speed of 10 mm/min. The results are shown in Table 1.

[Light Curing Conditions] The sealant was light-cured using an LED lamp emitting a wavelength of 395 nm (UV-LED LIGHT SOURCE H-4MLH200-V1 manufactured by HOYA) under the condition that the cumulative light intensity of the light at a wavelength of 395 nm reached 1,500 mJ/ ^cm2 , and a cured body with a curing rate of more than 80% was produced.

[Moisture permeability] A sheet-shaped hardened body with a thickness of 0.1 mm was prepared under the above-mentioned light curing conditions. In accordance with JIS Z0208:1976 "Moisture permeability test method for moisture-proof packaging materials (cup method)", calcium chloride (anhydrous) was used as a moisture absorbent, and the moisture permeability of the hardened body with a thickness of 100 μm was measured at a temperature of 23°C or 85°C and a relative humidity of 90% for 24 hours. The results are shown in Table 1. In addition, in the table, "-" is used to indicate the situation where the hardened body softens or dissolves at 85°C and is difficult to measure.

(Example 2) A sealant and its cured product were prepared and evaluated in the same manner as in Example 1 except that 100 parts by mass of pentafluorobenzyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 1. The content of fluorine atoms relative to the total amount of monomer components was 34% by mass.

(Example 3) A sealant and its cured product were prepared and evaluated in the same manner as in Example 1 except that 100 parts by mass of 2,2,3,3-tetrafluoropropyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) was used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 1. The content of fluorine atoms relative to the total amount of monomer components was 39% by mass.

(Example 4) A sealant and its cured product were prepared and evaluated in the same manner as in Example 1 except that 100 parts by mass of 1H,1H,5H-octafluoropentyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) was used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 1. The content of fluorine atoms relative to the total amount of monomer components was 51% by mass.

(Example 5) A sealant and its cured product were prepared and evaluated in the same manner as in Example 1 except that 100 parts by mass of 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexafluoro-1,10-decanediol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) was used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 1. The content of fluorine atoms relative to the total amount of monomer components was 51% by mass.

(Example 6) A sealant and its cured product were prepared and evaluated in the same manner as in Example 1 except that 20 parts by mass of 1H,1H,5H-octafluoropentyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) and 80 parts by mass of 1,6-hexanediol dimethacrylate were used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 1. The content of fluorine atoms relative to the total amount of monomer components was 10% by mass.

(Example 7) A sealant and its cured product were prepared in the same manner as in Example 1, except that 20 parts by mass of 1H,1H,5H-octafluoropentyl methacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.), 70 parts by mass of 1,12-dodecanediol dimethacrylate (manufactured by Sartomer Co., Ltd.), 5 parts by mass of dihydroxymethyltricyclodecane diacrylate (manufactured by Kyoeisha Chemical Co., Ltd.), and 5 parts by mass of ethoxylated o-phenylphenol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) were used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 1. The content of fluorine atoms relative to the total amount of monomer components was 10% by mass.

(Example 8) A sealant and a cured product thereof were prepared in the same manner as in Example 1, except that 1 part by mass of 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexafluoro-1,10-decanediol diacrylate (LINC-162A manufactured by Kyoeisha Chemical Co., Ltd.), 70 parts by mass of 1,12-dodecanediol dimethacrylate (manufactured by Sartomer Co., Ltd.), 24 parts by mass of dihydroxymethyltricyclodecane diacrylate (manufactured by Kyoeisha Chemical Co., Ltd.), and 5 parts by mass of ethoxylated o-phenylphenol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., a compound in which ^R7 in formula (B-1-1) is a hydrogen atom and n is 1) were used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 1. Furthermore, the content of fluorine atoms relative to the total amount of monomer components was 0.3 mass %.

(Example 9) A sealant and its cured product were prepared in the same manner as in Example 1, except that 1 part by mass of 1H,1H,2H,2H-tridecafluorooctyl acrylate (13F manufactured by Osaka Organic Chemical Industry Co., Ltd.), 79 parts by mass of 1,12-dodecanediol dimethacrylate (manufactured by Sartomer Co., Ltd.), 15 parts by mass of dihydroxymethyltricyclodecane diacrylate (manufactured by Kyoeisha Chemical Co., Ltd.), and 5 parts by mass of ethoxylated o-phenylphenol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) were used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 1. The content of fluorine atoms relative to the total amount of monomer components was 0.6% by mass.

(Example 10) A sealant and a cured product thereof were prepared and evaluated in the same manner as in Example 1, except that 1 part by mass of 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexafluoro-1,10-decanediol diacrylate (Lnic162A HP manufactured by Osaka Organic Chemical Industry Co., Ltd.), 63 parts by mass of 1,12-dodecanediol dimethacrylate (manufactured by Sartomer Co., Ltd.), 7.5 parts by mass of ethoxylated bisphenol A dimethacrylate (BPE-200 manufactured by Shin-Nakamura Chemical Co., Ltd., a compound in which R ⁸ and R ⁹ in formula (B-1-2) are methyl groups and m+n is 4), and 28.5 parts by mass of ethoxylated o-phenylphenol acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) were used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 1. The content of fluorine atoms relative to the total amount of the monomer components was 0.3 mass %.

(Comparative Example 1) A sealant and its cured product were prepared and evaluated in the same manner as in Example 1 except that 100 parts by mass of ethyl methacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) was used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 2.

(Comparative Example 2) A sealant and its cured product were prepared and evaluated in the same manner as in Example 1 except that 100 parts by mass of benzyl methacrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 2.

(Comparative Example 3) A sealant and its cured product were prepared and evaluated in the same manner as in Example 1 except that 100 parts by mass of butyl acrylate (manufactured by Mitsubishi Chemical Corporation) was used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 2.

(Comparative Example 4) A sealant and its cured product were prepared and evaluated in the same manner as in Example 1 except that 100 parts by mass of dodecanediol diacrylate (manufactured by Sartomer) was used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 2.

(Comparative Example 5) A sealant and its cured product were prepared and evaluated in the same manner as in Example 1 except that 20 parts by mass of butyl acrylate (manufactured by Mitsubishi Chemical Corporation) and 80 parts by mass of 1,6-hexanediol dimethacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) were used instead of trifluoromethyl methacrylate. The evaluation results are shown in Table 2.

(Comparative Example 6) A sealant and a cured product thereof were prepared and evaluated in the same manner as in Example 8 except that 1 part by mass of 1,12-dodecanediol dimethacrylate was used instead of 2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexafluoro-1,10-decanediol diacrylate. The evaluation results are shown in Table 2.

[Table 1]

[Table 2]

As shown in Table 1 and Table 2, the sealant of the embodiment can form a sealant having excellent wettability, adhesion and moisture resistance.

Claims (12)

A sealant for an organic electroluminescent display element, comprising: a monomer component comprising a fluorine-containing monomer (A) having a fluorine atom and a (meth)acryl group; and a photoradical polymerization initiator, wherein the fluorine-containing monomer (A) comprises a compound represented by formula (A-2-1), and the fluorine atom content of the monomer component is 0.1 mass % or more and 10 mass % or less based on the total amount of the monomer component.

In formula (A-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 greater than 1; a plurality of R ^3s may be the same or different from each other; a plurality of R ^41s may be the same or different from each other; wherein at least one of R ^41s is a fluorine atom. For example, in the sealant for an organic electroluminescent display element of claim 1, the fluorine atom content of the above-mentioned fluorine-containing monomer (A) is 2 to 75% by mass based on the total amount of the above-mentioned fluorine-containing monomer (A). As in claim 1 or 2, the sealant for an organic electroluminescent display element, wherein the above-mentioned monomer component further comprises a monomer (B), and the monomer (B) is a compound that does not have a fluorine atom and can be copolymerized with the above-mentioned fluorine-containing monomer (A). As in claim 3, the sealant for an organic electroluminescent display element, wherein the monomer component includes a monomer (B-1) having a ring structure as the monomer (B). As for the sealant for organic electroluminescent display elements of claim 4, the monomer (B-1) comprises at least one selected from the group consisting of ethoxylated o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, tricyclodecane dimethanol di(meth)acrylate and ethoxylated bisphenol A di(meth)acrylate. As in claim 3, the sealant for an organic electroluminescent display element, wherein the monomer component includes an alkanediol di(meth)acrylate (B-2) having an alkanediyl group with 6 or more carbon atoms as the monomer (B). As for the sealant for organic electroluminescent display elements of claim 6, the above-mentioned alkanediol di(meth)acrylate (B-2) comprises at least one selected from the group consisting of 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate and 1,12-dodecanediol di(meth)acrylate. As for the sealant for organic electroluminescent display element of claim 1 or 2, the above-mentioned photo-radical polymerization initiator comprises an acylphosphine oxide type photo-polymerization initiator. A hardened body, which is formed by hardening an organic electroluminescent display element as in any one of claims 1 to 8 with a sealant. A sealing material for an organic electroluminescent display element, comprising a hardened body as claimed in claim 9. A sealing material for an organic electroluminescent display element, comprising a laminate formed by laminating an inorganic film and an organic film, wherein the organic film comprises a hardened body as described in claim 9. An organic electroluminescent display device, comprising an organic electroluminescent display element and a sealing material for the organic electroluminescent display element as claimed in claim 10 or 11.