TW202346377A - Sealant for organic electroluminescent element, sealing material, organic electroluminescent display device, and method for producing sealant for organic electroluminescent element - Google Patents

Abstract

An object of the invention is to provide a sealant for organic electroluminescent elements that contains a radical polymerizable compound, a photopolymerization initiator, and a stable radical compound having a stable radical, wherein the acid value of the sealant is within a range from 0.01 to 0.15 (mgKOH/g).

Description

Sealing agent for organic electroluminescent elements, sealing material and organic electroluminescent display device, and method for manufacturing sealant for organic electroluminescent elements

The present invention relates to a sealant for organic electroluminescent elements, a sealing material, an organic electroluminescent display device, and a method for manufacturing the sealant for organic electroluminescent elements.

Organic electroluminescent elements (hereinafter also referred to as organic EL elements) attract attention as elements that can emit light with high brightness. However, organic EL elements have problems such as deterioration due to oxygen and moisture, resulting in reduced light-emitting properties. In order to solve this problem, some people are studying technology to seal organic EL elements and prevent deterioration.

As one of the sealing methods, for example, Patent Document 1 describes a sealant for organic EL elements, which contains a polymerizable compound and a polymerization initiator and has a viscosity of 5 to 50 mPa･s at 25°C. The tension is 15~35mN/m, and the moisture content at 25℃ after standing for 24 hours in an environment of 25℃ and 50%RH is less than 1000ppm. [Prior technical literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Publication No. 2019-040872

[Problem to be solved by the invention]

As sealants for organic EL elements, thermosetting sealants and photocurable sealants are known. Since the photocurable sealant does not require heating during sealing, it can form a sealing material without exposing the organic EL element to high heat, and has the advantage of suppressing deformation, deterioration, etc. of the organic EL element due to high heat.

In recent years, the required characteristics of electronic devices have increased, and for example, sealing materials that can achieve higher reliability for organic EL elements have been required.

However, in conventional photocurable sealants, it is difficult to sufficiently suppress the occurrence of dark spots in a durability test under high temperature and high humidity.

Therefore, an object of the present invention is to provide a sealant for organic EL elements that can significantly suppress the occurrence of dark spots under high temperature and high humidity. Furthermore, an object of the present invention is to provide a sealing material formed of the sealing compound for organic EL elements, an organic EL display device provided with the sealing material, and a method for manufacturing the sealing compound for organic EL elements. [Means to solve the problem]

The present invention relates to, for example, the following <1> to <7>. <1> A sealant for organic electroluminescent elements, containing: a radically polymerizable compound, a photopolymerization initiator, and a stable radical compound with stable radicals, and having an acid value of 0.01 to 0.15 (mgKOH/g ). <2> The sealing agent of <1>, wherein the stable radical is a nitroxide radical. <3> A sealing material containing a hardened body of the sealant of <1> or <2>. <4> An organic electroluminescence display device, including: an organic electroluminescence element, and a sealing material as in <3> for sealing the organic electroluminescence element. <5> A method of manufacturing a sealant for organic electroluminescent elements, which is the method of manufacturing the sealant of <1> or <2>, and includes the following steps: In the pretreatment step, at least a part of the radically polymerizable compound is degassed in an environment of 10 to 100°C and 1000 Pa or less so that the acid value of the sealant becomes 0.01 to 0.15 (mgKOH/g); and In the mixing step, the radically polymerizable compound, the photopolymerization initiator, and the stable radical compound having stable radicals are mixed to obtain the sealant. [Effects of the invention]

The present invention provides a sealant for organic EL elements that can significantly suppress the occurrence of dark spots under high temperature and high humidity. Furthermore, the present invention provides a sealing material formed from the sealing compound for organic EL elements, an organic EL display device provided with the sealing material, and a method for manufacturing the sealing compound for organic EL elements.

Hereinafter, ideal embodiments of the present invention will be described in detail.

In this specification, the expression "X~Y" in the description of the numerical range means above X and below Y, unless otherwise specified. For example, "1 to 5% by mass" means "1 to 5% by mass".

In the expression of a group (atomic group) in this specification, the expression that does not describe substituted or unsubstituted includes both those without a substituent and those with a substituent. For example, the so-called "alkyl group" includes not only an alkyl group without a substituent (unsubstituted alkyl group), but also an alkyl group with a substituent (substituted alkyl group).

The expression "(meth)acrylic acid" in this specification includes both acrylic acid and methacrylic acid. The same applies to similar expressions such as "(meth)acrylate".

＜Sealant＞ The sealant of this embodiment contains a radically polymerizable compound, a photopolymerization initiator, and a stable radical compound having stable radicals. Moreover, the acid value of the sealing agent of this embodiment is 0.01~0.15 (mgKOH/g).

The sealing agent of this embodiment is used for sealing organic electroluminescent elements. That is, the sealing agent of this embodiment is used to seal an organic EL element and manufacture an organic EL display device. Since the sealing agent of this embodiment contains a photopolymerization initiator, it is a photocurable sealing agent.

By sealing the organic EL element with the sealing agent of this embodiment, the occurrence of dark spots under high temperature and high humidity can be significantly suppressed.

The reason why the sealant of this embodiment exhibits the above-mentioned effects is not necessarily limited, but the following reasons are considered. According to the knowledge of the inventors of this case, conventional sealants contain a trace amount of acid component in the sealing material formed by hardening of the sealant, and due to the presence of this acid component, when moisture intrudes into the sealing material, Deterioration due to hydrolysis of the sealing material may occur and reliability may decrease. Since the acid value of the sealant of this embodiment is 0.15 mgKOH/g or less, there is little residual acid component in the sealing material, and even if a trace amount of moisture intrudes into the sealing material, hydrolysis of the sealing material is less likely to occur. Therefore, the sealant of this embodiment can form a sealing material that is not easily deteriorated even under high temperature and high humidity, and can suppress the occurrence of dark spots caused by the deterioration of the sealing material.

Moreover, the acid value of the sealing agent of this embodiment is 0.01 mgKOH/g or more, and contains a very trace amount of an acid component. In this embodiment, this very trace amount of the acid component functions as a polymerization inhibitor, and the sealing agent has excellent storage stability. It is considered that the decrease in reliability caused by deterioration of the sealing agent during storage is suppressed.

Moreover, the sealant of this embodiment has excellent dischargeability from the coating device. Specifically, the sealant according to this embodiment can suppress the bending of the discharged liquid and the difference in the amount of the discharged liquid when it is discharged from the coating device, thereby maintaining good dischargeability. Thereby, the sealant of this embodiment can form a coating film with significantly less thickness unevenness and excellent flatness. Furthermore, the sealing agent of this embodiment can form a sealing material that contributes to improving the reliability of organic EL elements.

The reason why the above-mentioned effect is exerted by the sealing agent of this embodiment is not necessarily limited, but the following reasons are considered. According to the knowledge of the inventors of the present invention, in conventional photocurable sealants, when the sealant is sprayed from a coating device, there may be a bend in the sprayed liquid, a difference in the amount of the sprayed liquid, etc., and therefore the coating film may be damaged. The thickness is uneven and the flatness of the coating film is reduced. The reason for this is that the photocurable sealant is prone to undesirable polymerization before use of the sealant (for example, during storage, transportation, etc.), and it is considered that the fine particles generated by the polymerization may cause damage to the coating device. Narrowing of the flow path may cause bending of the ejected liquid, differences in the amount of ejected liquid, etc. Since the sealant of this embodiment contains a stable radical type compound, although it is a photocurable sealant, undesired polymerization before use (for example, during storage, transportation, etc.) and particles caused by the polymerization will be significantly inhibited. Therefore, in the sealant of this embodiment, coating defects caused by fine particles are suppressed, excellent sprayability from the coating device, and high flatness of the coating film after coating are achieved.

In addition, in conventional photocurable sealants, when light is irradiated, there is a photopolymerization initiator, which is caused by uneven thickness of the coating film, differences in the amount of irradiation, etc., and is generated by the photopolymerization initiator. The reaction sites of free radical species and free radical species generated during the polymerization process remain in the hardened body. Furthermore, if such reaction points remain, further polymerization may occur in the hardened body after the sealing operation, and the hardened body may harden and shrink. Usually, an inorganic protective film with a thickness of about 1 μm is provided between the organic EL element and the sealing material (hardened body of the sealant). However, if curing shrinkage occurs, a load will be applied to the inorganic protective film and cracks may easily occur. The reliability of organic EL elements is reduced due to the intrusion of water or oxygen from cracks. Since the sealant of this embodiment contains a stable radical type compound, the above-mentioned reaction points are less likely to remain in the cured body, and further polymerization from the reaction points is also inhibited. Therefore, with the sealant of this embodiment, deterioration due to reaction points is less likely to occur, damage to the inorganic protective film due to hardening shrinkage can be suppressed, and a sealing material that contributes to improving the reliability of organic EL elements can be formed.

(Radically polymerizable compound) The radically polymerizable compound may be any compound that polymerizes due to active species generated from the photopolymerization initiator described below. A radical polymerizable compound may be used individually by 1 type, and may be used in combination of 2 or more types.

The radically polymerizable compound may be a compound having a radically polymerizable group. Examples of the radically polymerizable group include vinyl, (meth)acrylyl, allyl, vinylether, vinylester, and (meth)acrylamide. Among them, (Meth)acrylyl groups are particularly preferred.

The radically polymerizable compound preferably contains, for example, a polyfunctional compound having two or more radically polymerizable groups. The number of radically polymerizable groups in the polyfunctional compound may be, for example, 2 to 6, and preferably 2 to 4. By using a polyfunctional compound, photohardening properties tend to be further improved.

From the viewpoint of obtaining various properties as a sealing material in a well-balanced manner, a bifunctional compound having two radically polymerizable groups is preferably used as a polyfunctional compound.

The radically polymerizable compound may include a monofunctional compound having one radically polymerizable group. From the viewpoint of making it easier to adjust the polymerization rate, physical properties of the cured product, etc., the radically polymerizable compound preferably contains a polyfunctional compound and a monofunctional compound.

When the radically polymerizable compound contains a polyfunctional compound and a monofunctional compound, the proportion of the polyfunctional compound in the radically polymerizable compound can be, for example, 30% by mass or more, more preferably 50% by mass or more, and more preferably 60% by mass. % or more, more preferably 70 mass % or more, still more preferably 80 mass % or more, 85 mass % or more or 90 mass % or more. Moreover, the proportion of the polyfunctional compound in the polymerizable compound may be, for example, 100 mass% or less, and preferably 95 mass% or less. That is, the proportion of the polyfunctional compound in the radical polymerizable compound may be, for example, 30 to 100 mass %, 30 to 95 mass %, 50 to 100 mass %, 50 to 95 mass %, or 60 to 100 mass %. %, 60~95 mass%, 70~100 mass%, 70~95 mass%, 80~100 mass%, 80~95 mass%, 85~100 mass%, 85~95 mass%, 90~100 mass% or 90~95% by mass.

The polyfunctional compound is preferably a polyfunctional (meth)acrylic compound having two or more (meth)acrylyl groups. Specific examples of polyfunctional (meth)acrylic compounds include: Bis(1-(meth)acryloxy-2-hydroxypropyl)phthalate, bis(2-(meth)acryloxyethyl)phosphate, bis((methyl) Acryloxy-2-hydroxypropyloxy)diethylene glycol, bisphenol A di(meth)acrylate, bisphenol A di-(3-(meth)acryloxyethyl) ether, Bisphenol A di-(3-(meth)acryloxy-2-hydroxypropyl) ether, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di-( 3-(meth)acryloxy-2-hydroxypropyl) ether, 1,4-butanediol di(meth)acrylate, 1,3-butanediol bis((meth)acryloxy) propionate), 1,4-butanediol bis((meth)acryloxypropionate), 2-butene-1,4-diol di(meth)acrylate, 1,4 -Cyclohexanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, 2,2-dimethyl-1, 3-Propanediol di(meth)acrylate, dipenterythritol ether di(meth)acrylate, diphenolic acid di-(3-(meth)acryloxy-2-hydroxypropyl) ether, Dipropylene glycol di(meth)acrylate, 7,7,9-trimethyl-3,13-bisoxy-3,14-dioxa-5,12-diazahexadecane-1, 16-diol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 1,2-ethanediol di(meth)acrylate, 1,2-ethanediol di(meth)acrylate Alkanediol bis((meth)acryloxypropionate), 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1, 5-Pentanediol di(meth)acrylate, 1,4-phenylenediol di(meth)acrylate, 1-phenyl-1,2-ethanediol di(meth)acrylate, poly Oxyethyl-2,2-di(p-hydroxyphenyl)propane di(meth)acrylate, 1,2-propanediol di(meth)acrylate, 1,3-propanediol di(meth)acrylate , propoxylated bisphenol A di(meth)acrylate, tetrabromobisphenol A di-(3-(meth)acryloxy-2-hydroxypropyl) ether, tetrachlorobisphenol A di- (3-(meth)acryloxy-2-hydroxypropyl) ether, tetraethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, 2,2,4- Trimethyl-1,3-pentanediol di(meth)acrylate, tripropylene glycol di(meth)acrylate. Dihydroxymethyl-tricyclodecane di(meth)acrylate, 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, 2,2,3,3,4,4,5,5,6,6,7 , 7,8,8,9,9-hexadecafluoro-1,10-decane diacrylate and other difunctional (meth)acrylic acid compounds; 1,2,4-Butanetriol tri(meth)acrylate, glyceryl tri(meth)acrylate, neopentylerythritol tri(meth)acrylate, polyoxypropyl trimethylolpropane triacrylate (Meth)acrylate, polysilicone tri(meth)acrylate, 1,3,5-tris(meth)acryloylhexahydro-mesotriene, trimethylolethane tris(methyl) Acrylate, 1,1,1-trimethylolpropane tri(meth)acrylate, 1,2,3-trimethylolpropane tri(meth)acrylate, 1,1,1-trihydroxymethyl 1,2,3-trimethylolpropane ((meth)acryloxypropionate), 1,2,3-trimethylolpropane ((meth)acryloxypropionate), 2-(methyl Trifunctional (meth)acrylic compounds such as acryloyl(acryloxyethyl)isocyanurate; Tetrafunctional (meth)acrylic compounds such as neopentylerythritol tetra(meth)acrylate and neopentylerythritol tetra(meth)acryloyloxypropionate).

The monofunctional compound is preferably a monofunctional (meth)acrylic acid compound having one (meth)acrylyl group. Specific examples of the monofunctional (meth)acrylic compound include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and n-butyl (meth)acrylate. , tert-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, benzyl (meth)acrylate, (meth)acrylate ) Glycidyl acrylate, cyclohexyl (meth)acrylate, lauryl (meth)acrylate, n-octyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, (meth)acrylate Butoxyethyl acrylate, methoxytetraethylene glycol (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-(meth)acrylate Chloro-2-hydroxypropyl ester, tetrahydrofurfuryl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate (2-HPA), dicyclopentenyl (meth)acrylate , dicyclopentenyloxyethyl (meth)acrylate, dicyclopentyl (meth)acrylate, 4-butylphenyl (meth)acrylate, phenyl (meth)acrylate, (meth) 2,4,5-tetramethylphenyl acrylate, 4-chlorophenyl (meth)acrylate, phenoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-(meth)acrylate (Methyl)acryloxyhexahydrophthalic acid, 2-(meth)acryloxyethyl-2-hydroxypropylphthalic acid, EO modified phenol (meth)acrylate, EO modified methyl Phenol (meth)acrylate, EO modified nonylphenol (meth)acrylate, PO modified nonylphenol (meth)acrylate, ethoxylated-o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, (methyl) 1H, 1H, 5H-octafluoropentyl acrylate, 1H, 1H, 2H, 2H-tridecafluorooctyl (meth)acrylate, etc.

The radically polymerizable compound preferably contains a compound having an aromatic ring (hereinafter also referred to as an aromatic monomer.). As a result, the moisture permeability of the hardened body tends to be further reduced.

When the radically polymerizable compound contains an aromatic monomer, the proportion of the aromatic monomer in the radically polymerizable compound can be, for example, 1% by mass or more, more preferably 2% by mass or more, and more preferably 3% by mass or more. , it can also be 5 mass% or more. Moreover, the proportion of the aromatic monomer in the radically polymerizable compound can be, for example, 70 mass% or less, preferably 60 mass% or less, more preferably 50 mass% or less, and even more preferably 40 mass% or less. It may be 30 mass% or less, 20 mass% or less, 15 mass% or less, or 10 mass% or less. That is, the proportion of the aromatic monomer in the radical polymerizable compound may be, for example, 1 to 70 mass %, 1 to 60 mass %, 1 to 50 mass %, 1 to 40 mass %, or 1 to 30 mass %. Mass%, 1~20% by mass, 1~15% by mass, 1~10% by mass, 2~70% by mass, 2~60% by mass, 2~50% by mass, 2~40% by mass, 2~30% by mass , 2~20 mass%, 2~15 mass%, 2~10 mass%, 3~70 mass%, 3~60 mass%, 3~50 mass%, 3~40 mass%, 3~30 mass%, 3 ~20 mass%, 3~15 mass%, 3~10 mass%, 5~70 mass%, 5~60 mass%, 5~50 mass%, 5~40 mass%, 5~30 mass%, 5~20 Mass%, 5~15% by mass or 5~10% by mass.

In terms of aromatic monomers, examples include: Benzyl (meth)acrylate, 4-butylphenyl (meth)acrylate, phenyl (meth)acrylate, 2,4,5-tetramethylphenyl (meth)acrylate, (meth)acrylic acid 4-Chlorophenyl ester, phenoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate (2-HPA), 2-(meth)acryloxyhexahydrophthalic acid, 2-(meth)acryloxyethyl-2-hydroxypropyl phthalic acid, EO modified phenol (meth)acrylate, EO modified cresol (meth)acrylate, EO modified nonylphenol (meth)acrylate, PO modified nonylphenol (meth)acrylate, ethoxylated-o-phenylphenol (meth)acrylate ) Compounds with one aromatic ring such as acrylate and m-phenoxybenzyl (meth)acrylate; Ethoxylated bisphenol A di(meth)acrylate, propoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, bis Compounds with two or more aromatic rings, such as phenol A epoxy di(meth)acrylate, etc.

From the viewpoint that the moisture permeability of the hardened body is further reduced and the reliability of the organic EL element is further improved, the aromatic monomer is preferably a compound having two or more aromatic rings. The radically polymerizable compound, as the aromatic monomer, includes a group selected from the group consisting of ethoxylated-o-phenylphenol (meth)acrylate, m-phenoxybenzyl (meth)acrylate, and ethoxylated bisphenol A. Preferably, at least one of the group of di(meth)acrylates is selected from the group consisting of ethoxylated-o-phenylphenol (meth)acrylate and ethoxylated bisphenol A di(meth)acrylate. More preferably, at least one type of the group consisting of esters is used.

The radically polymerizable compound contains an alicyclic monomer having a radically polymerizable group and an aliphatic hydrocarbon ring.

The aliphatic hydrocarbon ring of the alicyclic monomer may be a single ring or a condensed ring. In addition, the aliphatic hydrocarbon ring may be a saturated hydrocarbon ring or an unsaturated hydrocarbon ring. The saturated hydrocarbon ring may be a cycloalkane ring. Examples of the unsaturated aliphatic hydrocarbon ring include a cycloalkene ring, a cycloalkenadiene ring, a cycloalkantriene ring, and the like, and a cycloalkene ring is preferred.

Examples of the cycloalkane ring include a cyclopentane ring, a cyclohexane ring, a tetrahydrodicyclopentadiene ring, a cycloheptane ring, a cyclooctene ring, a norbornane ring, and an adamantane ring.

Examples of the cycloolefin ring include a cyclopentene ring, a cyclohexene ring, a dihydrodicyclopentadiene ring, a cycloheptene ring, a cyclooctene ring, a norbornene ring, and the like. The cycloolefin ring is preferably a cyclopentene ring, a cyclohexene ring or a dihydrodicyclopentadiene ring with a large ring strain, considering the excellent oxygen capture function of the unsaturated bonding part. A cyclopentene ring or A dihydrodicyclopentadiene ring is more preferred.

The alicyclic monomer may be a monofunctional compound having one radical polymerizable group or a polyfunctional compound having two or more radical polymerizable groups. The number of radically polymerizable groups in the alicyclic monomer can be, for example, 1 to 6, preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 to 2.

The alicyclic monomer may be a compound having one aliphatic hydrocarbon ring or a compound having two or more aliphatic hydrocarbon rings. The number of aliphatic hydrocarbon rings in the alicyclic monomer can be, for example, 1 to 6, preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 to 2.

As for alicyclic monomers, examples include: Tricyclodecane dimethanol di(meth)acrylate, 1,4-cyclohexanediol di(meth)acrylate, cyclohexyl(meth)acrylate, dicyclopentyl(meth)acrylate, etc. Saturated alicyclic monomer; Unsaturated alicyclic monomers such as dicyclopentenyl (meth)acrylate and dicyclopentenyloxyethyl (meth)acrylate, etc.

The proportion of the alicyclic monomer in the radically polymerizable compound can be, for example, 3% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. In addition, the proportion of the alicyclic monomer in the radically polymerizable compound can be, for example, 90 mass% or less, preferably 70 mass% or less, more preferably 50 mass% or less, and even more preferably 40 mass%. the following. That is, the proportion of the alicyclic monomer in the radical polymerizable compound may be, for example, 3 to 90 mass %, 3 to 70 mass %, 3 to 50 mass %, 3 to 40 mass %, 5 to 90 mass%, 5~70 mass%, 5~50 mass%, 5~40 mass%, 10~90 mass%, 10~70 mass%, 10~50 mass%, 10~40 mass%, 15~90 mass %, 15~70% by mass, 15~50% by mass or 15~40% by mass.

The radical polymerizable compound preferably contains a non-cyclic monomer which has a radical polymerizable group and does not have a ring structure.

The number of radically polymerizable groups of the acyclic monomer may be, for example, 1 or more, and preferably 2 or more. The number of radically polymerizable groups the acyclic monomer has can be, for example, 6 or less, preferably 4 or less, and more preferably 3 or less. It is particularly preferable that the acyclic monomer has a number of radically polymerizable groups of two. That is, the number of radically polymerizable groups the acyclic monomer has may be, for example, 1 to 6, 1 to 4, 1 to 3, 2 to 6, 2 to 4, or 2 to 3.

Examples of the acyclic monomer include compounds having a radically polymerizable group and a chain saturated hydrocarbon group (hereinafter also referred to as a chain monomer).

The number of carbon atoms in the chain saturated hydrocarbon group of the chain monomer is, for example, 2 or more, and may also be 3 or more, 4 or more, 6 or more, 8 or more, or 10 or more. The number of carbon atoms in the chain saturated hydrocarbon group of the chain monomer may be, for example, 16 or less, or 15 or less, 14 or less, or 13 or less. That is, the carbon number of the chain saturated hydrocarbon group of the chain monomer may be, for example, 2 to 16, 2 to 15, 2 to 14, 2 to 13, 3 to 16, 3 to 15, 3 to 14, 3 ~13, 4~16, 4~15, 4~14, 4~13, 6~16, 6~15, 6~14, 6~13, 8~16, 8~15, 8~14, 8~13 , 10~16, 10~15, 10~14 or 10~13.

The chain saturated hydrocarbon group of the chain monomer is preferably an alkanediyl group. The ideal range of the carbon number of the alkylenediyl group is the same as the ideal range of the carbon number of the chain saturated hydrocarbon group.

When the radically polymerizable compound contains a chain monomer, the proportion of the chain monomer in the radically polymerizable compound can be, for example, 10% by mass or more, preferably 20% by mass or more, and more preferably 30% by mass. It may be more than 40% by mass, 50% by mass or more, or 55% by mass or more. Moreover, the proportion of the chain monomer in the radically polymerizable compound can be, for example, 90 mass% or less, preferably 85 mass% or less, and more preferably 80 mass% or less. That is, the proportion of the chain monomer in the radical polymerizable compound may be, for example, 10 to 90 mass %, 10 to 85 mass %, 10 to 80 mass %, 20 to 90 mass %, or 20 to 85 mass %. Mass%, 20~80% by mass, 30~90% by mass, 30~85% by mass, 30~80% by mass, 40~90% by mass, 40~85% by mass, 40~80% by mass, 50~90% by mass , 50~85 mass%, 50~80 mass%, 55~90 mass%, 55~85 mass% or 55~80 mass%.

As for chain monomers, examples include: 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol Glycol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate (Meth)acrylate, 1,13-tridecanediol di(meth)acrylate, 1,14-tetradecanediol di(meth)acrylate, 1,15-pentadecanediol Di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, neopentyl glycol dimethacrylate, 1,12-dodecanediol di(meth)acrylate Ester and other alkylene glycol di(meth)acrylates; Diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate and other polyethylene glycol di(meth)acrylates; Dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, etc.

The radically polymerizable compound preferably contains a compound having a fluorine group (hereinafter also referred to as a fluorine-containing monomer). This lowers the surface free energy of the sealant, making it easier to follow fine irregularities, and the flatness of the coating film tends to be further improved.

When the radically polymerizable compound contains a fluorine-containing monomer, the proportion of the fluorine-containing monomer in the radically polymerizable compound can be, for example, 0.1% by mass or more, more preferably 0.3% by mass or more, and more preferably 0.5% by mass. It may be 0.7% by mass or more, 0.9% by mass or more, or 1% by mass or more. In addition, the proportion of the fluorine-containing monomer in the radically polymerizable compound may be, for example, 15% by mass or less, preferably 10% by mass or less, or 7% by mass or less, 5% by mass or less, or 3% by mass. or less than 2% by mass. That is, the proportion of the fluorine-containing monomer in the radical polymerizable compound may be, for example, 0.1 to 15 mass %, 0.1 to 10 mass %, 0.1 to 7 mass %, 0.1 to 5 mass %, or 0.1 to 3 mass %. Mass%, 0.1~2 mass%, 0.3~15 mass%, 0.3~10 mass%, 0.3~7 mass%, 0.3~5 mass%, 0.3~3 mass%, 0.3~2 mass%, 0.5~15 mass% , 0.5~10 mass%, 0.5~7 mass%, 0.5~5 mass%, 0.5~3 mass%, 0.5~2 mass%, 0.7~15 mass%, 0.7~10 mass%, 0.7~7 mass%, 0.7 ~5 mass%, 0.7~3 mass%, 0.7~2 mass%, 0.9~15 mass%, 0.9~10 mass%, 0.9~7 mass%, 0.9~5 mass%, 0.9~3 mass%, 0.9~2 Mass %, 1 to 15 mass %, 1 to 10 mass %, 1 to 7 mass %, 1 to 5 mass %, 1 to 3 mass %, or 1 to 2 mass %.

The number of fluorine groups the fluorine-containing monomer has may be, for example, 1 or more, preferably 2 or more, and more preferably 3 or more. In addition, the number of fluorine groups the fluorine-containing monomer has is not particularly limited, but may be, for example, 40 or less, preferably 30 or less. That is, the number of fluorine groups the fluorine-containing monomer has may be, for example, 1 to 40, 1 to 30, 2 to 40, 2 to 30, 3 to 40, or 3 to 30.

The content of fluorine atoms relative to the total amount of fluorine-containing monomers can be, for example, 1 mass % or more, preferably 2 mass % or more, and more preferably 5 mass % or more. By using a fluorine-containing monomer that satisfies this content range, the above effects will be more pronounced. Moreover, the content of fluorine atoms relative to the total amount of fluorine-containing monomers may be, for example, 75 mass% or less, preferably 70 mass% or less, and more preferably 65 mass% or less. That is, the content of fluorine atoms relative to the total amount of fluorine-containing monomers may be, for example, 1 to 75 mass %, 1 to 70 mass %, 1 to 65 mass %, 2 to 75 mass %, or 2 to 70 mass %. , 2~65 mass%, 5~75 mass%, 5~70 mass% or 5~65 mass%.

The number of radically polymerizable groups the fluorine-containing monomer has may be 1 or more. From the viewpoint of making it easier to obtain a hardened product with a low glass transition temperature, the number of radical polymerizable groups the fluorine-containing monomer has may be one. In addition, from the viewpoint of making it easier to obtain a hardened product with a high glass transition temperature, the number of radical polymerizable groups the fluorine-containing monomer has may be 2 or more. The upper limit of the number of radically polymerizable groups the fluorine-containing monomer has is not particularly limited. The number of radically polymerizable groups of the fluorine-containing monomer is, for example, 4 or less. From the viewpoint of easily obtaining a cured product having excellent flexibility, it is preferably 3 or less, and more preferably 2 or less.

Examples of the fluorine-containing monomer include 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, and methyl (meth)acrylate. 1H,1H,5H-Octafluoropentyl acrylate, 1H,1H,2H,2H-tridecafluorooctyl (meth)acrylate, 2,2,3,3,4,4,5,5,6,6 ,7,7,8,8,9,9-hexadecafluoro-1,10-decane di(meth)acrylate, etc.

(Photopolymerization initiator) The photopolymerization initiator may be any initiator capable of polymerizing the radically polymerizable compound. A photopolymerization initiator may be used individually by 1 type, and may be used in combination of 2 or more types.

As for photopolymerization initiators, examples include: Benzophenone and its derivatives; Benzyl and its derivatives; Anthraquinone and its derivatives; Benzoin-type photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isobutyl ether, benzyl dimethyl ketal; Acetophenone-type photopolymerization initiators such as diethoxyacetophenone and 4-tert-butyltrichloroacetophenone; 2-Dimethylaminoethylbenzoate; p-Dimethylaminoethylbenzoate; diphenyl disulfide; Thioxanthone and its derivatives; Camphorquinone, 7,7-dimethyl-2,3-di-oxybicyclo[2.2.1]heptane-1-carboxylic acid, 7,7-dimethyl-2,3-di-oxybicyclo[2.2.1]heptane-1-carboxylic acid [2.2.1]Heptane-1-carboxy-2-bromoethyl ester, 7,7-dimethyl-2,3-dilateral oxybicyclo[2.2.1]heptane-1-carboxy-2-methyl Camphorquinone type photopolymerization initiators such as ester, 7,7-dimethyl-2,3-di-oxybicyclo[2.2.1]heptane-1-carboxylic acid chloride; 2-Methyl-1-[4-(methylthio)phenyl]-2-𠰌linylpropan-1-one, 2-benzyl-2-dimethylamino-1-(4-𠰌line α-aminoalkyl phenyl ketone type photopolymerization initiator such as phenyl)-butanone-1; Benzyldiphenylphosphine oxide, 2,4,6-trimethylbenzyldiphenylphosphine oxide, benzoyldiethoxyphosphine oxide, 2,4,6-trimethyl Benzyldimethoxyphenylphosphine oxide, 2,4,6-trimethylbenzoyldiethoxyphenylphosphine oxide, bis(2,4,6-trimethylbenzoyldiethoxyphenylphosphine oxide) Phosphine-based photopolymerization initiators such as phenylphosphine oxide; Phenyl-glyoxylic acid-methyl ester; Oxy-phenyl-acetic acid 2-[2-side oxy-2-phenyl-acetyloxy-ethoxy]-ethyl ester; Oxy-phenyl-acetic acid 2-[2-hydroxy-ethoxy]-ethyl ester, etc.

As for the photopolymerization initiator, it can be hardened using only visible light of 390nm or above. From the viewpoint of being able to harden without causing damage to the organic EL element, a acylphosphine oxide type photopolymerization initiator is ideal. Regarding the acylphosphine oxide type photopolymerization initiator, considering the fact that the transparency of the cured product is more improved and that curing can be performed using only light of 395 nm or above, 2,4,6-trimethylbenzyl Carboxyl-diphenyl-phosphine oxide is preferred. Examples of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide include "Omnirad TPO" manufactured by IGM Resins.

The content of the photopolymerization initiator may be, for example, 0.05 parts by mass or more, preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass, based on 100 parts by mass of the radically polymerizable compound. above. Moreover, the content of the photopolymerization initiator may be, for example, 10 parts by mass or less, preferably 8 parts by mass or less, and more preferably 5 parts by mass or less based on 100 parts by mass of the radically polymerizable compound. If the content is such, sufficient sensitivity and hardening speed of the sealant can be obtained, and sufficient transparency of the sealing material tends to be easily ensured. That is, the content of the photopolymerization initiator may be, for example, 0.05 to 10 parts by mass, 0.05 to 8 parts by mass, 0.05 to 5 parts by mass, or 0.5 to 10 parts by mass relative to 100 parts by mass of the radically polymerizable compound. 0.5~8 parts by mass, 0.5~5 parts by mass, 1~10 parts by mass, 1~8 parts by mass, 1~5 parts by mass, 2~10 parts by mass, 2~8 parts by mass or 2~5 parts by mass.

(Stable free radical compound) Stable free radical compounds are compounds with stable free radicals. A photopolymerization initiator may be used individually by 1 type, and may be used in combination of 2 or more types.

In terms of stable radicals, nitroxide radicals (NO radicals) are preferred. That is, as a stable radical type compound, a compound containing a nitroxide radical is preferable. Since nitroxide radicals have excellent compatibility and reactivity with radically polymerizable compounds, they can quickly capture radical species.

In the manufacturing process of organic EL display devices, organic EL elements are degraded by oxygen, so they are managed at a low oxygen concentration of less than 1 ppm. The sealant for organic EL elements is also used at a low oxygen concentration. In contrast, general phenolic antioxidants used to suppress polymerization inhibition of radically polymerizable compounds require reaction with oxygen in the process of exerting their polymerization inhibitory function. Therefore, it is difficult for a phenolic antioxidant to exert a polymerization inhibitory function in a sealant for organic EL elements. In this regard, stable radical-type compounds having stable radicals (especially nitroxide radicals) can capture radical species regardless of the presence or absence of oxygen, and thus can significantly achieve the above effects.

Examples of stable radical compounds include 1-oxy-2,2,6,6-tetramethylpiperidine and 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxide. substances, 4-(meth)acryloxy-2,2,6,6-tetramethylpiperidine 1-oxide, etc., considering that it will be absorbed in the hardened body and not easily become a dissipated gas, 4- (Meth)acrylyloxy-2,2,6,6-tetramethylpiperidine 1-oxide is preferably 4-methacrylyloxy-2,2,6,6-tetramethyl Piperidine 1-oxide is more preferred.

The content of the stable radical compound may be, for example, 1 mass ppm or more, preferably 10 mass ppm or more, more preferably 50 mass ppm or more, and even more preferably 100 mass ppm, based on 100 parts by mass of the radically polymerizable compound. above. Moreover, the content of the stable radical type compound may be, for example, 15,000 mass ppm or less, preferably 10,000 mass ppm or less, more preferably 8,000 mass ppm or less, and even more preferably 6,000 mass ppm based on 100 mass parts of the radical polymerizable compound. Quality ppm or less. By using an appropriate amount of stable free radical compounds, the above effects will be more pronounced. That is, the content of the stable radical type compound may be, for example, 1 to 15,000 mass ppm, 1 to 10,000 mass ppm, 1 to 8,000 mass ppm, 1 to 6,000 mass ppm, relative to 100 parts by mass of the radically polymerizable compound. 10~15000 mass ppm, 10~10000 mass ppm, 10~8000 mass ppm, 10~6000 mass ppm, 50~15000 mass ppm, 50~10000 mass ppm, 50~8000 mass ppm, 50~6000 mass ppm, 100~ 15000 mass ppm, 100~10000 mass ppm, 100~8000 mass ppm or 100~6000 mass ppm.

(other ingredients) The sealant of this embodiment may further contain other components other than those mentioned above. Examples of other components include antioxidants, surfactants, sensitizers, and the like.

The content of other components is not particularly limited, but may be, for example, 10 parts by mass or less, more preferably 5 parts by mass or less, more preferably 3 parts by mass or less, or 2 parts by mass, based on 100 parts by mass of the radically polymerizable compound. parts or less or less than 1 part by mass.

The viscosity of the sealant in this embodiment is preferably 3 mPa･s or more, and more preferably 5 mPa･s or more. Moreover, the viscosity of the sealant of this embodiment is preferably 50 mPa･s or less, and more preferably 30 mPa･s or less. If the viscosity of the sealant is in the above range, the sprayability when applied by the inkjet method will be further improved, and the formation of the coating film will tend to be easier. That is, the viscosity of the sealant may also be, for example, 3~50mPa･s, 3~30mPa･s, 5~50mPa･s or 5~30mPa･s.

In addition, in this manual, the viscosity of the sealant shows the value measured using a cone and plate viscometer (manufactured by Eiko Seiki Co., Ltd., model: HB DV3T, etc.) at 25°C and 250 rpm.

The sulfur atom concentration of the sealant of this embodiment can be, for example, 100 ppm or less, preferably 50 ppm or less, and more preferably 40 ppm or more. The sulfur atom concentration of the sealant of this embodiment may be, for example, 0.1 ppm or more or 1 ppm or more. That is, the sulfur atom concentration of the sealant of this embodiment may be, for example, 0.1 to 100 ppm, 0.1 to 50 ppm, 0.1 to 40 ppm, 1 to 100 ppm, 1 to 50 ppm, or 1 to 40 ppm. If the sulfur atom concentration is such, the deterioration of the organic EL element and the occurrence of dark spots will be more significantly suppressed, and the reliability will tend to be further improved.

The moisture concentration of the sealant of this embodiment can be, for example, 100 ppm or less, preferably 70 ppm or less, and more preferably 50 ppm or less. The moisture concentration of the sealant in this embodiment may be, for example, 0.5 ppm or more, or 1 ppm or more. That is, the moisture concentration of the sealant of this embodiment may be, for example, 0.5 to 100 ppm, 0.5 to 70 ppm, 0.5 to 50 ppm, 1 to 100 ppm, 1 to 70 ppm, or 1 to 50 ppm. At such a moisture concentration, the above-mentioned effects tend to be more pronounced.

The number of particles with a diameter of 1 μm or more present in 1 mL of the sealant of this embodiment is defined as a, and the number of particles with a diameter of 1 μm or more present in 1 mL of the sealant heated at 80° C. for 16 hours is defined as b. When , b-a is ideally below 10. With such a sealant, coating defects caused by fine particles are suppressed, excellent sprayability from the coating device, and high flatness of the coating film after coating are achieved.

The above a is preferably 10 or less, more preferably 5 or less, still more preferably 3 or less, but may be 0.

The above b is preferably 10 or less, more preferably 5 or less, still more preferably 3 or less, and may be 0.

The sealant of this embodiment may contain fine particles of 1 μm or more, but it is preferred not to contain them (that is, a is 0). Examples of the fine particles include fine particles derived from polymers of radically polymerizable compounds, fine particles derived from foreign matter such as dust and ash, and particles derived from dehydrating agents such as molecular sieves used in the production step of the sealant. Particles etc. The sealant of this embodiment does not substantially contain these particles, and may be obtained by removing the particles with a filter material or the like.

In addition, in this specification, the number of microparticles shows the value measured using a microparticle counter (manufactured by Rion Corporation, light scattering particle detector in liquid, model: KS-42B).

The acid value of the sealant of this embodiment is 0.15 (mgKOH/g) or less, preferably 0.13 (mgKOH/g) or less, more preferably 0.10 (mgKOH/g) or less. In this way, the above effects will be more significant. Moreover, the acid value of the sealing agent of this embodiment is 0.01 (mgKOH/g) or more, preferably 0.015 (mgKOH/g) or more, and more preferably 0.02 (mgKOH/g) or more. Thereby, the effect as a polymerization inhibitor of the acid component will be more remarkable. That is, the acid value of the sealant of this embodiment may be, for example, 0.01 to 0.15 (mgKOH/g), 0.01 to 0.13 (mgKOH/g), 0.01 to 0.10 (mgKOH/g), or 0.015 to 0.15 (mgKOH/g). g), 0.015~0.13(mgKOH/g), 0.015~0.10(mgKOH/g), 0.02~0.15(mgKOH/g), 0.02~0.13(mgKOH/g) or 0.02~0.10(mgKOH/g).

The acid value of the sealant of this embodiment shows the value measured by the following method. Weigh 2g of the sample into a 50mL tall beaker, add 40mL of 2-propanol, and stir for 5 minutes. After confirming that the potential is stable, the end point is determined by potentiometric titration using the automatic titration device COM 550 manufactured by Hiranuma Seisakusho Co., Ltd. using the titrant solution 0.1 mol/L 2-propanol potassium hydroxide standard solution (Wako Pure Chemical Industries, Ltd.).

The manufacturing method of the sealant of this embodiment is not specifically limited, For example, it can be manufactured by the following method.

(Method of manufacturing sealant) The method for producing a sealant according to this embodiment includes the following steps in order to make the acid value of the sealant 0.01 to 0.15 (mgKOH/g): converting at least part of the radically polymerizable compound by the method of the following (i) A pretreatment step of pretreatment; and a mixing step of mixing a radically polymerizable compound, a photopolymerization initiator, and a stable radical compound having stable radicals to obtain a sealant. In addition, the pre-processing step may further include pre-processing by methods (ii) and (iii). (i) Degassing treatment in an environment of 10~100℃ and below 1000Pa (ii) Distillation and refining (iii) Refining by column chromatography

According to the findings of the present inventors, the acid value of the sealant originates from a trace amount of acid component in the radically polymerizable compound. Therefore, in the manufacturing method of this embodiment, the acid value of the sealant is adjusted to a specific range by pre-processing the radically polymerizable compound in the pre-treatment step.

The pre-treatment method in the pre-treatment step includes (i), and may also include any of (ii) and (iii).

＜Pretreatment method (i)＞ The pretreatment method (i) is a method of degassing the radically polymerizable compound.

When a plurality of radically polymerizable compounds are present, each radically polymerizable compound can be degassed individually in the pretreatment method (i), or a plurality of radically polymerizable compounds can be degassed simultaneously (containing a plurality of radically polymerizable compounds). A mixture of various free radical polymerizable compounds is degassed).

The temperature during degassing treatment is 10~100℃, preferably 30~90℃, more preferably 40~80℃.

The pressure during the degassing process is 1000 Pa or less, preferably 800 Pa or less, and more preferably 500 Pa or less. Moreover, the pressure in the degassing process may be, for example, 1 Pa or more, or 10 Pa or more. That is, the pressure in the degassing process may be, for example, 1 to 1000 Pa, 1 to 800 Pa, 1 to 500 Pa, 10 to 1000 Pa, 10 to 800 Pa, or 10 to 500 Pa.

The degassing process can be performed, for example, in a container equipped with a stirring device and connected to a vacuum pump and a vacuum gauge. In the degassing treatment, bubbling (blowing of air) with air may be performed from the viewpoint of maintaining an appropriate degree of vacuum and suppressing the polymerization of the polymerizable compound.

＜Pretreatment method (ii)＞ The pretreatment method (ii) is a method of distilling and purifying the radically polymerizable compound.

The ideal conditions for distillation and purification include a temperature of 10 to 100°C and a pressure of 0.1 MPa or less.

Specific examples of distillation purification include the following methods. In addition, the method of distillation and purification is not limited to the following method, and can be appropriately selected from known methods of distillation and purification. The radically polymerizable compound was placed in a temperature bath adjusted to 65°C using a rotary distillation device ("Rotary Evaporator N-1000S" manufactured by Tokyo Rika Instruments Co., Ltd.) at a pressure of 0.05MPa. Distill at 50r/min for 3 hours.

＜Pretreatment method (iii)＞ The pretreatment method (iii) is a method of purifying the radically polymerizable compound by column chromatography.

Examples of column chromatography purification include column chromatography purification using silica gel as an adsorbent material.

Specific examples of column chromatography purification include the following methods. In addition, the column chromatography purification method is not limited to the following method, and can be appropriately selected from known column chromatography purification methods. Fill the glass column with silica gel, dissolve the radically polymerizable compound with a developing solvent of ethyl acetate:heptane = 2:98, place it on the silica gel, and use the same developing solvent for separation and purification. The solvent in the obtained solution is removed, and a purified radically polymerizable compound is obtained.

In the pretreatment step, pretreatment is performed so that the acid value of the sealant becomes 0.01 to 0.15 (mgKOH/g). The pretreatment conditions and the like can be appropriately adjusted depending on the blending amount of the radically polymerizable compound in the sealant. That is, in the pretreatment step, the pretreatment conditions and the like can be appropriately adjusted based on the predetermined composition of the sealant.

The mixing step is a step of mixing a radically polymerizable compound, a photopolymerization initiator, and a stable radical compound having stable radicals to obtain a sealant.

The mixing method in the mixing step is not particularly limited, and examples thereof include mixing with a mixer such as a Sany motor, mixing with a mixing rotor, and the like.

Ideal mixing conditions in the mixing step include, for example, a temperature of 15 to 40°C and mixing for more than 1 hour.

＜Sealing material＞ By curing the sealant of this embodiment, a cured body of a polymer containing a radically polymerizable compound can be obtained. This hardened body may contain stable radicals in terms of stable radical compounds or reactants thereof. This hardened body can be ideally used as a sealing material for organic EL elements.

The sealant of this embodiment can be hardened by light irradiation. The light source used for hardening the sealant in this embodiment is not particularly limited. Examples of light sources include halogen lamps, metal halide lamps, high-energy metal halide lamps (containing indium, etc.), low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, xenon excimer lamps, and xenon flashes. Lamps, LEDs, etc.

The above-mentioned light sources have different emission wavelengths and energy distributions. Therefore, the above-mentioned light source can be appropriately selected according to the reaction wavelength of the photopolymerization initiator and the like. In addition, natural light (sunlight) can also be used as a reaction starting light source.

The irradiation by the light source can be direct irradiation, or it can be concentrated light irradiation through a reflector, optical fiber, etc. Alternatively, irradiation using a low-wavelength cutoff filter, a heat ray cutoff filter, a cold light mirror, or the like may be used.

As a method of sealing an organic EL element using the sealing agent of this embodiment, the following sealing method etc. are mentioned.

･Sealing method A substrate on which the organic EL element is mounted is prepared, and a sealant is applied on the surface of the substrate on which the organic EL element is mounted to form a coating film of the sealant. Then, the coating film is irradiated with light to form a sealing material composed of a cured body of the sealing agent. Thereby, the organic EL element is sealed by the sealing material.

When applying sealant, inkjet method is more ideal. In the production of organic EL display devices, it is necessary to apply a sealant to a large-area substrate on which a plurality of organic EL elements are provided. Since the sealant of this embodiment can be applied while maintaining high ejection properties even using an inkjet method, a coating film can be formed uniformly on a large-area substrate.

The film thickness of the coating film of the sealant can be, for example, 1 μm or more, preferably 3 μm or more. This makes it easy to form a sealing material with sufficient sealing performance. Moreover, the film thickness of the sealant coating film can be, for example, 10 μm or less, preferably 9 μm or less. Therefore, miniaturization of organic EL display devices, reduction of manufacturing costs, etc. are expected. That is, the film thickness of the sealant coating may be, for example, 1 to 10 μm, 1 to 9 μm, 3 to 10 μm, or 3 to 9 μm.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments. For example, the present invention can adopt various configurations other than those described above. In addition, the present invention may be a modification, improvement, etc. of the above-described embodiment within the scope that achieves the object of the present invention.

For example, the present invention may relate to an organic EL display device including an organic EL element and a sealing material for sealing the organic EL element. The sealing material contains a hardened body of the above-mentioned sealing agent. In this organic EL display device, the organic EL element may be a known organic EL element. In addition, the structure other than the organic EL element and the sealing material can be the same as that of a known organic EL display device. [Example]

Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

In Examples and Comparative Examples, the following components were used. (A) Radically polymerizable compound (A-1) SR262 (1,12-dodecanediol dimethacrylate, manufactured by ARKEMA) (chain monomer) (A-2) BPE200 (ethoxy Bisphenol A dimethacrylate (compound represented by the following formula (m+n=4), manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) (aromatic monomer) [Chemical 1] (A-3)LINC-162A(2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9-hexadecafluoro-1,10-dec Alkane diacrylate, manufactured by Kyeisha Chemical Co., Ltd.) (fluorinated monomer) (A-4) FA-512AS (dicyclopentenyloxyethyl acrylate, manufactured by Showa Denko Materials Co., Ltd.) (unsaturated alicyclic Monomer) (A-5) DCP (dimethylol-tricyclodecane dimethacrylate, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.) (saturated alicyclic monomer)

(B)Polymerization initiator (B-1) TPO (2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, manufactured by IGM Resins)

(C) Stable radical compounds (C-1) TEMPO methacrylate (4-methacryloxy-2,2,6,6-tetramethylpiperidine 1-oxide, manufactured by Tokyo Chemical Industry Co., Ltd.)

In Examples and Comparative Examples, the following measurements and evaluations were performed.

(Determination of acid value) Weigh 2g of the sample into a 50mL tall beaker, add 40mL of 2-propanol, and stir for 5 minutes. After confirming that the potential is stable, the end point is determined by potentiometric titration using an automatic titration device COM 550 manufactured by Hiranuma Seisakusho Co., Ltd. using a titrant solution of 0.1 mol/L 2-propanol potassium hydroxide standard solution (manufactured by Wako Pure Chemical Industries, Ltd.).

(Reliability evaluation of organic EL display devices (organic EL reliability)) ･Preparation of organic EL display devices for evaluation A glass substrate (thickness 700 μm) with a 30 mm square ITO electrode was cleaned using acetone and isopropyl alcohol respectively. . After that, the following compounds are sequentially evaporated into thin films using a vacuum evaporation method to obtain a structure composed of anode/hole injection layer/hole transport layer/light-emitting layer/Hole Blocking layer/electron transport layer/electron injection layer/ The substrate of the 2mm square organic EL element composed of the cathode. The composition of each layer is as follows. Anode (ITO): 150nm Hole injection layer (polymer HIL): 60nm Hole transport layer (α-NPD): 30nm Luminous layer (Ir(ppy) ₃ +CBP[6%]): 30nm Hole Blocking layer (BAlq ): 10nm Electron transport layer (Alq ₃ ): 30nm Electron injection layer (LiF): 0.8nm Cathode (MgAg/IZO): 10nm/100nm ITO-based indium tin oxide, HIL-based Hole Injection Layer, α-NPD-based N,N '-Diphenyl-N,N'-dinaphthylbenzidine, Ir(ppy) _3- series iridium complex [ref. (2-phenylpyridine)iridium], CBP series 4,4'-N,N' -Dicarbazole-biphenyl, BAlq series bis(2-methyl-8-hydroxyquinoline)(p-phenylphenol)aluminum, Alq ₃ series ginseng (8-hydroxyquinoline)aluminum, LiF series lithium fluoride, IZO is indium zinc oxide. Next, an inkjet device (model: DMP2850) manufactured by Fuji Film Co., Ltd. was used in a nitrogen atmosphere to drop the sealant in such a manner as to cover the 2 mm × 2 mm organic EL element, thereby obtaining a coating film with a thickness of 10 μm. After that, in a nitrogen atmosphere, the coating film was treated with an LED lamp (UV-LED LIGHT SOURCE H-4MLH200-V1 manufactured by HOYA Corporation) that emits light with a wavelength of 395 nm so that the cumulative light intensity becomes 1,500 mJ/cm ² Irradiate light with a wavelength of 395nm. Thereby, a cured film is obtained. A mask (mask) having an opening of 10 mm×10 mm was provided so as to cover the entire cured film obtained, and a SiN film was formed by a plasma CVD method. The thickness of the formed SiN (inorganic film) is approximately 1 μm. Thereby, a sealed body of an organic EL element is obtained. The obtained sealed body was bonded to a 30 mm × 30 mm × 25 μmt transparent double-sided adhesive tape without a base material and a 30 mm × 30 mm × 0.7 mmt alkali-free glass (Eagle XG manufactured by Corning Co., Ltd.). In this way, an organic EL display device for evaluation was produced. ･Reliability test: The organic EL display device used for evaluation is left standing in a high temperature and high humidity environment of 85°C and 85%RH for 500 hours. Before and after this high-temperature and high-humidity treatment, a current was passed through the organic EL display device for evaluation, and the light-emitting surface was photographed. The images obtained by photography (the image before the high temperature and high humidity treatment and the image after the high temperature and high humidity treatment) were analyzed using INNOTECH's image analysis software "Quick Grain" to obtain the luminous area. Then, the reduction rate (%) of the light-emitting area before and after the high-temperature and high-humidity treatment was calculated.

(Examples 1 to 2, Comparative Example 1) The radically polymerizable compounds shown in Table 1 were mixed with the composition shown in Table 1, and degassed for the time shown in Table 1 in an environment of 60° C. and 800 Pa. Then, each component was mixed in the composition shown in Table 1 to prepare a sealant. The above-mentioned measurement and evaluation were performed on the obtained sealant. The results are shown in Table 1.

(Examples 3~4, Comparative Example 2) The radically polymerizable compounds shown in Table 2 were mixed with the composition shown in Table 2, and degassed for the time shown in Table 2 in an environment of 60° C. and 800 Pa. Then, each component was mixed in the composition shown in Table 2 to prepare a sealant. The above-mentioned measurement and evaluation were performed on the obtained sealant. The results are shown in Table 2.

[Table 1] Example 1 Example 2 Comparative example 1 Free radical polymerizable compound (mass part) (A-1)SR262 60 60 60 (A-2)BPE200 9 9 9 (A-3)LINC-162A 1 1 1 (A-4)FA-512AS 30 30 30 (A-5)DCP - - - Polymerization initiator (mass parts) (B-1)TPO 3 3 3 Stable free radical compounds (mass ppm) (C-1)TEMPO methacrylate 4000 4000 4000 Degassing treatment time (minutes) 60 10 0 Acid value (mgKOH/g) 0.01 0.07 0.16 Organic EL reliability (light-emitting area reduction rate (%)) 2 16 47

[Table 2] Example 3 Example 4 Comparative example 2 Free radical polymerizable compound (mass part) (A-1)SR262 75 75 75 (A-2)BPE200 9 9 9 (A-3)LINC-162A 1 1 1 (A-4)FA-512AS - - - (A-5)DCP 15 15 15 Polymerization initiator (mass parts) (B-1)TPO 3 3 3 Stable free radical compounds (mass ppm) (C-1)TEMPO methacrylate 4000 4000 4000 Degassing treatment time (minutes) 60 10 0 Acid value (mgKOH/g) 0.01 0.08 0.17 Organic EL reliability (light-emitting area reduction rate (%)) 3 20 53

Claims (5)

A sealant for organic electroluminescent elements, containing: a radical polymerizable compound, a photopolymerization initiator, and a stable radical compound with stable radicals, And the acid value is 0.01~0.15 (mgKOH/g). The sealing agent for organic electroluminescent elements of claim 1, wherein the stable free radical is a nitroxide radical. A sealing material comprising a cured body of the sealant for organic electroluminescent elements according to claim 1 or 2. An organic electroluminescent display device having: organic electroluminescent components, and The organic electroluminescent element is sealed with the sealing material of claim 3. A method for manufacturing a sealant for organic electroluminescent elements, which is the method for manufacturing a sealant for organic electroluminescent elements according to claim 1 or 2, and includes the following steps: In the pretreatment step, at least a part of the radically polymerizable compound is subjected to an environment of 10 to 100°C and 1000 Pa or less so that the acid value of the sealant for organic electroluminescent elements becomes 0.01 to 0.15 (mgKOH/g). Perform degassing; and In the mixing step, the radically polymerizable compound, the photopolymerization initiator, and the stable radical compound having stable radicals are mixed, and the sealing agent for organic electroluminescent elements is obtained.