KR102624114B1 - Sealing composition - Google Patents

Abstract

A composition for sealing an organic EL device is provided, which can efficiently seal an organic EL device with a cured material that has low outgassing properties and moisture resistance without directly exposing the device to UV. The composition for sealing an organic EL device of the present invention contains the following components (A), (B), and (C). Component (A): Cationic curable compound having two or more of one or more groups per molecule selected from alicyclic epoxy groups, oxetane ring-containing groups, episulfide groups, and vinyl ether groups. Component (B): Photocationic polymerization initiator. Ingredient (C): Glycoluril Compound

Description

Sealing composition

The present invention relates to a sealing composition that can seal an organic EL element without damaging it and protect the organic EL element from deterioration due to moisture. This application claims priority to Japanese Patent Application No. 2015-233349, filed in Japan on November 30, 2015, and uses the contents herein.

An organic electroluminescence (hereinafter sometimes referred to as “organic EL”) device has a structure in which a light-emitting layer is sandwiched by a pair of opposing electrodes, and electrons are injected from one electrode and electrons are emitted from the other electrode. Holes are injected. Light emission occurs when the injected electrons and holes recombine within the light-emitting layer. Organic EL devices containing the organic EL elements are expected to be used as full-color flat panel displays or as a replacement for LEDs due to their impact resistance, high visibility, and diversity of emission colors. There are two types of light extraction methods for organic EL devices, top emission type and bottom emission type, and the top emission type is preferable because it has a large aperture ratio and has excellent light extraction efficiency.

However, organic EL elements are more susceptible to moisture than other electronic components, and moisture entering the organic EL elements causes oxidation of electrodes and modification of organic materials, causing a significant decline in luminescence characteristics. A known method of solving this problem is to seal (or cover) the perimeter of the organic EL element with a cured product of a sealing composition.

As the sealing method, method (1) is filled by filling the perimeter of an organic EL element formed on a substrate with a sealing composition that is cured by UV irradiation, and then sealing by curing the sealing composition, or a lid (cover) A method (2) is known in which a sealing composition is applied to a substrate, irradiated with UV light, and then bonded to a substrate on which an organic EL element is formed and sealed.

The problem with the above method (1) was that the organic EL device was directly exposed to UV, resulting in a decrease in luminescence characteristics. In addition, when a color filter is placed on top of an organic EL element to form an organic EL device with high contrast, the problem is that curing of the sealing composition becomes insufficient because UV is blocked by the color filter.

On the other hand, in the method (2), it is possible to prevent the organic EL element from being deteriorated in luminous properties due to direct exposure to UV, but since curing of the sealing composition progresses rapidly due to UV irradiation, if the bonding operation is delayed, bonding may occur. The problem was that this became difficult and the yield decreased.

In Patent Document 1, a sealing composition containing an epoxy compound, a polymerization initiator, and a crown ether or polyether as a curing retardant has the characteristic that the reaction proceeds and curing is completed even when UV is blocked after UV irradiation, It is described that when the composition is used in method (2), sealing is possible while suppressing deterioration of the organic EL element due to UV. However, the problem is that crown ethers and polyethers are decomposed by positive ions to generate outgas, and the outgas deteriorates the organic EL device.

Japanese Patent No. 4384509 Publication

Therefore, an object of the present invention is to provide a composition for sealing an organic EL device that can efficiently seal the organic EL device with a cured material that has low outgassing properties and moisture resistance without directly exposing the device to UV.

Another object of the present invention is to provide a composition for sealing an organic EL device that can efficiently seal the organic EL device with a cured material that has low outgassing properties, moisture resistance, and conductivity without directly exposing the device to UV. .

The present inventor has conducted intensive studies to solve the above problems, and as a result, the glycoluril compound, which is weakly basic with respect to the cation generated from the photo cationic polymerization initiator, traps the cation generated from the photo cation polymerization initiator by UV irradiation and undergoes cationic polymerization. suppresses the progress of and can have the effect of releasing positive ions and advancing cationic polymerization when heat treated, and the glycoluril compound may not cause outgassing, and by adding the glycoluril compound, it can be used for sealing. The pot life of the composition can be freely controlled, and the coating film of the sealing composition is irradiated with UV and then bonded to the organic EL element and then subjected to heat treatment, without directly exposing the organic EL element to UV. It was discovered that the organic EL element could be sealed with a cured product that could be sealed without making bonding difficult and had low outgassing properties and moisture resistance with good yield.

Furthermore, it was discovered that when specific conductive fiber covering particles were added to the sealing composition, in addition to the above-mentioned characteristics, an organic EL element could be sealed with a conductive cured material.

The present invention was completed based on their knowledge.

That is, the present invention provides a composition for sealing an organic electroluminescent device containing the following components (A), (B), and (C).

Component (A): A cationic curable compound having two or more groups per molecule, one or more groups selected from alicyclic epoxy groups, oxetane ring-containing groups, episulfide groups, and vinyl ether groups.

Component (B): Photocationic polymerization initiator

Ingredient (C): Glycoluril Compound

The present invention further provides the composition for sealing an organic electroluminescent device, wherein component (C) is a glycoluril compound containing a glycidyl group or an allyl group.

The present invention further provides the composition for sealing an organic electroluminescent device as described above, containing 0.05 to 3 parts by weight of component (C) relative to 1 part by weight of component (B).

The present invention further provides the composition for sealing an organic electroluminescent device as described above, which further contains the following component (D).

Component (D): Compounds having one or more glycidyl ether groups per molecule (excluding compounds included in component (A))

The present invention further provides the composition for sealing an organic electroluminescent device as described above, which contains an inorganic filler having an average particle diameter of 0.001 to 30 μm.

The present invention further provides the composition for sealing an organic electroluminescent device as described above, which further contains the following conductive fiber covering particles.

Conductive fiber covering particles: Conductive fiber covering particles containing a particulate material and a fibrous conductive material covering the particulate material.

The present invention further provides the above-described composition for sealing organic electroluminescent devices, which is for sealing top-emission type organic electroluminescent devices.

The present invention also provides a method for manufacturing an organic electroluminescent device, characterized in that the organic electroluminescent device is sealed through the following steps 1 and 2.

Step 1: Light irradiation is applied to a coating film made of the composition for sealing an organic electroluminescent device.

Step 2: The light-irradiated coating film obtained through Step 1 is bonded to the device installation surface of the substrate on which the device is installed and subjected to heat treatment.

The present invention further provides an organic electroluminescent device comprising a cured product of the composition for sealing an organic electroluminescent element.

That is, the present invention relates to the following.

[1] A composition for sealing an organic electroluminescent device, containing the following components (A), (B), and (C).

Component (A): A cationic curable compound having two or more groups per molecule, one or more groups selected from alicyclic epoxy groups, oxetane ring-containing groups, episulfide groups, and vinyl ether groups.

Component (B): Photocationic polymerization initiator

Ingredient (C): Glycoluril Compound

[2] The composition for sealing an organic electroluminescent device according to [1], wherein component (A) contains a compound having two or more cyclohexene oxide groups per molecule.

[3] The composition for sealing an organic electroluminescence device according to [1], wherein component (A) contains a compound represented by formula (a).

[4] Component (A) is (3,4,3',4'-diepoxy)bicyclohexyl, bis(3,4-epoxycyclohexylmethyl)ether, 1,2-epoxy-1,2- Bis(3,4-epoxycyclohexan-1-yl)ethane, 2,2-bis(3,4-epoxycyclohexan-1-yl)propane and 1,2-bis(3,4-epoxycyclohexane- 1-yl) The composition for sealing an organic electroluminescence device according to [1], containing at least one compound selected from the group consisting of ethane.

[5] Component (A) is 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, 1,4-bis[(3-ethyl-3-oxetanylmethyl) Toxy)methyl]benzene, bis{[1-ethyl(3-oxetanyl)]methyl}ether, 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]bicyclohexyl, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]cyclohexane, 3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane and The composition for sealing an organic electroluminescent device according to any one of [1] to [4], containing at least one compound selected from the group consisting of phenol novolak-type oxetane.

[6] The composition for sealing an organic electroluminescent device according to any one of [1] to [5], wherein component (A) contains an episulfide compound having a fluorene skeleton.

[7] The composition for sealing an organic electroluminescent device according to any one of [1] to [6], wherein the component (A) contains a cyclic ether-type vinyl ether compound.

[8] The organic electrolumine according to any one of [1] to [7], wherein the proportion of component (A) in the total amount (100% by weight) of the cationically curable compound contained in the sealing composition is 30 to 80% by weight. Composition for sealing sense elements.

[9] Sealing the organic electroluminescent device according to any one of [1] to [8], wherein the content of component (B) is 0.05 to 4 parts by weight based on 100 parts by weight of the cationically curable compound contained in the sealing composition. Composition for.

[10] The composition for sealing an organic electroluminescent device according to any one of [1] to [9], wherein the component (C) is a compound represented by formula (c).

[11] The composition for sealing an organic electroluminescent device according to any one of [1] to [9], wherein the component (C) is a glycoluril compound containing a glycidyl group or an allyl group.

[12] The composition for sealing an organic electroluminescent device according to any one of [1] to [11], containing 0.05 to 3 parts by weight of component (C) relative to 1 part by weight of component (B).

[13] The composition for sealing an organic electroluminescence device according to any one of [1] to [12], further containing the following component (D).

Component (D): Compounds having one or more glycidyl ether groups per molecule (excluding compounds included in component (A))

[14] The organic electrolumine according to any one of [1] to [13], wherein the proportion of component (D) in the total amount (100% by weight) of the cationically curable compound contained in the sealing composition is 20 to 70% by weight. Composition for sealing sense elements.

[15] Any one of [1] to [14], wherein the total amount of component (A) and component (D) in the total amount (100% by weight) of the cationically curable compound contained in the sealing composition is 70% by weight or more. The composition for sealing an organic electroluminescence device as described in .

[16] The composition for sealing an organic electroluminescent device according to any one of [1] to [15], further comprising an inorganic filler having an average particle diameter of 0.001 to 30 μm.

[17] The composition for sealing an organic electroluminescent device according to any one of [1] to [16], further comprising the following conductive fiber covering particles.

Conductive fiber covering particles: Conductive fiber covering particles containing a particulate material and a fibrous conductive material covering the particulate material.

[18] The composition for sealing an organic electroluminescent device according to any one of [1] to [17], which is for sealing a top-emission type organic electroluminescent device.

[19] The composition for sealing an organic electroluminescent device according to any one of [1] to [18], wherein the composition has a viscosity (25°C, shear rate: 20 (1/s)) of 10 to 10,000 mPa·s.

[20] The composition for sealing an organic electroluminescent device according to any one of [1] to [19], wherein the viscosity increase from immediately after irradiation of ultraviolet rays (irradiation amount: 2000 mJ/cm2) to 30 minutes after irradiation is 1.5 times or less.

[21] A method of manufacturing an organic electroluminescent device, characterized in that the organic electroluminescent device is sealed through the following steps 1 and 2.

Step 1: Light irradiation is applied to a coating film made of the composition for sealing an organic electroluminescent element according to any one of [1] to [20].

Step 2: The light-irradiated coating film obtained through Step 1 is bonded to the device installation surface of the substrate on which the organic electroluminescence device is installed and subjected to heat treatment.

[22] An organic electroluminescent device comprising a cured product of the composition for sealing an organic electroluminescent element according to any one of [1] to [20].

[23] The organic electroluminescence device according to [22], wherein the cured product (thickness: 100 μm) has a moisture permeability of 150 g/m2·day·atm or less.

Since the composition for sealing organic EL devices of the present invention has the above structure, even if the coating film is irradiated with UV, the progress of curing can be suppressed until heat treatment is performed, and even if the progress of the bonding operation is delayed, the adhesiveness is maintained. There is no risk of loss or difficulty in joining. Also, curing can be advanced by heat treatment after bonding, and the organic EL element can be sealed without being directly exposed to UV. In addition, the composition for sealing an organic EL device of the present invention has moisture resistance and can form a cured product with low outgassing properties, thereby preventing deterioration of the organic EL device due to moisture or outgassing. Additionally, when the composition for sealing an organic EL device of the present invention contains conductive fiber covering particles, a cured product that also has conductivity can be formed.

Therefore, the composition for sealing organic EL devices of the present invention or the sheet or film made of the composition for sealing organic EL devices of the present invention can be suitably used for sealing top-emission type organic EL devices.

Additionally, an organic EL device sealed with the composition for sealing an organic EL device of the present invention or a sheet or film made of the composition for sealing an organic EL device of the present invention has excellent luminescence characteristics, has a long life and is highly reliable.

Figure 1 is an example of a scanning electron microscope image (SEM image) of conductive fiber-covered particles in the present invention.
Figure 2 is a schematic diagram showing an example of a method for manufacturing an organic EL device using the composition for sealing an organic EL device of the present invention.

[Composition for sealing organic EL devices]

The composition for sealing an organic EL device (hereinafter sometimes referred to as “composition for sealing”) of the present invention contains the following components (A), (B), and (C).

Component (A): A cationic curable compound having two or more groups per molecule, one or more groups selected from alicyclic epoxy groups, oxetane ring-containing groups, episulfide groups, and vinyl ether groups.

Component (B): Photocationic polymerization initiator

Ingredient (C): Glycoluril Compound

(Component (A))

Component (A) of the present invention includes an alicyclic epoxy group (an epoxy group composed of two adjacent carbon atoms and an oxygen atom constituting an alicyclic ring, such as a cyclohexene oxide group, etc.), an oxetane ring-containing group, an episulfide group, and It is a cation-curable compound having two or more of one or two or more groups selected from vinyl ether groups in one molecule. Compounds included in component (C) are excluded.

Examples of the compound having two or more alicyclic epoxy groups per molecule (hereinafter sometimes referred to as “alicyclic epoxy compound”) include a compound represented by the following formula (a).

In the formula (a), R ¹ to R ¹⁸ are the same or different and represent a hydrocarbon group that may contain a hydrogen atom, a halogen atom, an oxygen atom, or a halogen atom, or an alkoxy group that may have a substituent.

Examples of the halogen atom for R ¹ to R ¹⁸ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the hydrocarbon group for R ¹ to R ¹⁸ include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and groups in which two or more of these are bonded.

Examples of the aliphatic hydrocarbon group include C _1-20 alkyl groups such as methyl, ethyl, propyl _{, isopropyl, butyl, hexyl, octyl, isooctyl, decyl, and dodecyl (preferably C 1-10 alkyl groups} are particularly preferred). For example, C _1-4 alkyl group) _; Vinyl, allyl, methallyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl , C _2-20 alkenyl groups such as 5-hexenyl groups _{(preferably C 2-10 alkenyl} groups, particularly preferably C _2-4 alkenyl groups _{) ;} and C _{2-20 alkynyl} groups such as ethynyl and propynyl groups _{(preferably C 2-10 alkynyl} groups, particularly preferably C _{2-4 alkynyl} groups).

Examples of the alicyclic hydrocarbon group include C _3-12 cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, _and cyclododecyl; C _3-12 cycloalkenyl groups such as cyclohexenyl groups; and C _4-15 cross _- linked hydrocarbon groups such as bicycloheptanyl and bicycloheptenyl groups.

_{Examples of the aromatic hydrocarbon group include C 6-14 aryl groups such as phenyl and naphthyl groups (preferably C 6-10 aryl groups )} .

In addition, examples of groups in which two or more groups selected _from the above-mentioned aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups are bonded include C _3-12 cycloalkyl-substituted C _1-20 alkyl groups such as cyclohexylmethyl group; C _1-20 alkyl substituted C _3-12 cycloalkyl groups such as methylcyclohexyl _{group ;} C _7-18 aralkyl groups such as benzyl group and phenethyl group _{(especially C 7-10 aralkyl} groups) _; C _6-14 aryl substituted C _{2- 20} alkenyl group such as cinnamyl group _; C _1-20 alkyl _{-substituted C 6-14 aryl} groups such as tolyl groups _; and C _2-20 alkenyl-substituted C _6-14 aryl groups such _as styryl _groups .

Examples of the hydrocarbon group that may contain an oxygen atom or a halogen atom for R ¹ to R ¹⁸ include groups in which at least one hydrogen atom in the above-mentioned hydrocarbon group is substituted with an oxygen atom or a halogen atom. . Examples of the group having the oxygen atom include hydroxyl group; hydroperoxy group; C _1-10 alkoxy groups such as methoxy, ethoxy, propoxy, isopropyloxy, butoxy, and isobutyloxy groups _; C _2-10 alkenyloxy groups such as allyloxy groups _; C _6-14 aryloxy group which may have a substituent selected from C _1-10 alkyl group, C _2-10 alkenyl group, halogen atom and C _{1-10 alkoxy} group ₍ for example, tolyloxy, naphthyloxy _{group ,} etc.) ; C _7-18 aralkyloxy groups such as benzyloxy and phenethyloxy groups _; C _1-10 acyloxy groups such as acetyloxy, propionyloxy, (meth)acryloyloxy, and benzoyloxy groups _; C _1-10 alkoxycarbonyl groups such as methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, and butoxycarbonyl groups _; C _6-14 aryloxycarbonyl group which may have a substituent selected from C _1-10 alkyl group, C _2-10 alkenyl group, halogen atom and C _{1-10 alkoxy} group _{( for} example, phenoxycarbonyl, _{tolyloxycarbonyl} Bornyl, naphthyloxycarbonyl group, etc.); C _7-18 aralkyloxycarbonyl groups such as benzyloxycarbonyl groups _; Epoxy group-containing groups such as glycidyloxy groups; Oxetanyl group-containing groups such as ethyloxetanyloxy group; C _1-10 acyl groups such as acetyl, propionyl, and benzoyl groups _; isocyanate earthenware; drinking alcohol; Carbamoyl; oxo group; _Examples include groups where two or more of these are bonded together through a single bond or a C _1-10 alkylene group.

Examples of the alkoxy group for R ¹ to R ¹⁸ include C _1-10 alkoxy groups such as methoxy, ethoxy, propoxy, isopropyloxy _, butoxy, and isobutyloxy.

Substituents that the alkoxy _{group may have include, for example, a halogen atom, hydroxyl group, C 1-10 alkoxy group, C 2-10 alkenyloxy group, C 6-14 aryloxy group , C 1-10 acyloxy} group _, Mercapto group, C _{1- 10} alkylthio group, C _{2- 10} alkenylthio group, C _{6- 14} arylthio group, C _{7- 18} aralkylthio group, carboxyl group, C _{1- 10} alkoxycarbonyl group, C _{6- 14} aryl Oxycarbonyl group, _{C 7-18} aralkyloxycarbonyl group, amino group _, mono or _{diC 1-10 alkylamino} group, C _1-10 acylamino group, epoxy group-containing group, _oxetanyl group-containing group, C _{1-10 acyl} group, oxo group , and groups in which two or more of these are bonded through a single bond or a C _1-10 alkylene group, etc.

In the above formula (a), X represents a single bond or a linking group (a divalent group having one or more atoms). Examples of the linking group include a divalent hydrocarbon group, an alkenylene group in which part or all of the carbon-carbon double bond is epoxidized, a carbonyl group, an ether bond, an ester bond, a carbonate group, an amide group, and a plurality of these linked together. etc. can be mentioned.

Examples of the divalent hydrocarbon group include linear or branched alkylene groups having 1 to 18 carbon atoms, divalent alicyclic hydrocarbon groups having 3 to 18 carbon atoms, and the like. Examples of the linear or branched alkylene group having 1 to 18 carbon atoms include methylene group, methylmethylene group, dimethylmethylene group, ethylene group, propylene group, and trimethylene group. Examples of divalent alicyclic hydrocarbon groups having 3 to 18 carbon atoms include 1,2-cyclopentylene group, 1,3-cyclopentylene group, cyclopentylidene group, 1,2-cyclohexylene group, and 1,3-cyclopentylene group. and cycloalkylene groups (including cycloalkylidene groups) such as cyclohexylene group, 1,4-cyclohexylene group, and cyclohexylidene group.

Examples of the alkenylene group in the alkenylene group in which part or all of the carbon-carbon double bond is epoxidized (sometimes referred to as “epoxidized alkenylene group”) include vinylene group, propenylene group, 1 - Linear or branched alkenylene groups having 2 to 8 carbon atoms, such as butenylene group, 2-butenylene group, butadienylene group, pentenylene group, hexenylene group, heptenylene group, octenylene group, etc. there is. In particular, the epoxidized alkenylene group is preferably an alkenylene group in which all of the carbon-carbon double bonds are epoxidized, and more preferably an alkenylene group having 2 to 4 carbon atoms in which all of the carbon-carbon double bonds are epoxidized. am.

As the connecting group A group in which a plurality of these groups are connected; Examples include groups in which 1 or 2 or more of these groups are connected to 1 or 2 or more of the divalent hydrocarbon groups.

Representative examples of the alicyclic epoxy compound represented by the formula (a) include, for example, (3,4,3',4'-diepoxy)bicyclohexyl, bis(3,4-epoxycyclohexylmethyl)ether. , 1,2-epoxy-1,2-bis (3,4-epoxycyclohexan-1-yl) ethane, 2,2-bis (3,4-epoxycyclohexan-1-yl) propane, 1,2 -bis(3,4-epoxycyclohexan-1-yl)ethane, compounds represented by the following formulas (1) to (10), etc. In addition, L in the following formula (5) is an alkylene group having 1 to 8 carbon atoms, and among these, a linear or branched alkylene group having 1 to 3 carbon atoms is preferable. n 1 to n ⁸ in the following formulas (5), ( ⁷ ), (9), and (10) are the same or different and represent an integer of 1 to 30.

As alicyclic epoxy compounds, among them, (3,4,3',4'-diepoxy)bicyclohexyl and/ Alternatively, it is preferable to use bis(3,4-epoxycyclohexylmethyl)ether. From the viewpoint of moisture resistance of the cured product, (3,4,3',4'-diepoxy)bicyclohexyl is particularly preferable.

Examples of the compounds having two or more oxetane ring-containing groups per molecule (hereinafter sometimes referred to as “oxetane compounds”) include 4,4'-bis[(3-ethyl-3-oxetanyl). Methoxymethyl]biphenyl, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, bis{[1-ethyl(3-oxetanyl)]methyl}ether, 4,4 '-bis[(3-ethyl-3-oxetanyl)methoxymethyl]bicyclohexyl, 1,4-bis[(3-ethyl-3-oxetanyl)methoxymethyl]cyclohexane, 3-ethyl -3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane, phenol novolak-type oxetane, etc. can be presented. For example, commercial products such as “ETERNACOLL OXBP” (manufactured by Ube Kosan Co., Ltd.) can be used.

Examples of the compounds having two or more episulfide groups per molecule include 1,3-bis(β-epithiopropylthio)cyclohexane and 1,3-bis(β-epithiopropylthiomethyl)cyclohexane. , bis[4-(β-epithiopropylthio)cyclohexyl]methane, 2,2-bis[4-(β-epithiopropylthio)cyclohexyl]propane, bis[4-(β-epithiopropylthio) )Cyclohexyl]sulfide, 2,5-bis(β-epithiopropylthio)-1,4-dithiane, 2,5-bis(β-epithiopropylthioethylthiomethyl)-1,4-dithiane Episulfide compounds having an alicyclic group such as Ahn; 1,3-bis(β-epithiopropylthio)benzene, 1,3-bis(β-epithiopropylthiomethyl)benzene, bis[4-(β-epithiopropylthio)phenyl]methane, 2,2 -bis[4-(β-epithiopropylthio)phenyl]propane, bis[4-(β-epithiopropylthio)phenyl]sulfide, bis[4-(β-epithiopropylthio)phenyl]sulfine, Episulfide compounds having an aromatic ring such as 4,4-bis(β-epithiopropylthio)biphenyl; 2-(2-β-epithiopropylthioethylthio)-1,3-bis(β-epithiopropylthio)propane, 1,2-bis[(2-β-epithiopropylthioethyl)thio]- Alkyl sulfide-type episulphide such as 3-(β-epithiopropylthio)propane, tetrakis(β-epithiopropylthiomethyl)methane, and 1,1,1-tris(β-epithiopropylthiomethyl)propane. feed compound; 9,9-bis{4-[2-(2,3-epithiopropoxy)ethoxy]phenyl}fluorene, 9,9-bis{4-[2-(2,3-epithiopropoxy) Ethoxy]-3-methylphenyl}fluorene, 9,9-bis{4-[2-(2,3-epithiopropoxy)ethoxy]-3,5-dimethylphenyl}fluorene, 9,9- Bis{4-[2-(2,3-epithiopropoxy)ethoxy]-3-phenylphenyl}fluorene, 9,9-bis{6-[2-(2,3-epithiopropoxy) Fluorene skeleton such as ethoxy]-2-naphthyl}fluorene, 9,9-bis{5-[2-(2,3-epithiopropoxy)ethoxy]-1-naphthyl}fluorene, etc. Episulfide compounds having such compounds can be mentioned.

Examples of the compounds having two or more vinyl ether groups per molecule (hereinafter sometimes referred to as “vinyl ether compounds”) include cyclic ether-type vinyl such as isosorbide divinyl ether and oxynorbornene divinyl ether. Ether compounds (vinyl ether compounds having cyclic ether groups such as oxirane ring, oxetane ring, and oxolane ring); Aryl divinyl ether compounds such as hydroquinone divinyl ether; Vinyl ether compounds having a chain hydrocarbon group such as 1,4-butanediol divinyl ether; chain ether-type vinyl ether compounds such as triethylene glycol divinyl ether; Vinyl ether compounds having a cyclic hydrocarbon group such as cyclohexane divinyl ether and cyclohexanedimethanol divinyl ether can be mentioned.

Component (A) can be used individually or in combination of two or more types. The proportion of component (A) in the total amount (100% by weight) of the cationically curable compound contained in the sealing composition of the present invention is, for example, about 30 to 80% by weight, preferably 40 to 60% by weight. Containing the component (A) in the above range is preferable because the progress of hardening can be suppressed while a delay in hardening is desired, and hardening can be achieved quickly after heat treatment. If the content of component (A) is less than the above range, it tends to be difficult to obtain a sufficient curing speed even if heat treatment is performed. On the other hand, when the content of component (A) exceeds the above range, it tends to become difficult to obtain a sufficient curing delay effect.

(Component (B))

Component (B) of the present invention is a photo cationic polymerization initiator that generates cationic species upon irradiation of light to initiate a curing reaction of the cationically curable compound. The photo cationic polymerization initiator consists of a cationic portion that absorbs light and an anionic portion that serves as a source of acid.

Examples of the photo cationic polymerization initiator of the present invention include diazonium salt-based compounds, iodonium salt-based compounds, sulfonium salt-based compounds, phosphonium salt-based compounds, selenium salt-based compounds, oxonium salt-based compounds, ammonium salt-based compounds, bromine salt-based compounds, etc. can be mentioned. Among them, it is preferable to use a sulfonium salt-based compound because it can form a cured product with excellent curability.

Examples of the cationic portion of the sulfonium salt compound include arylsulfonium ions such as triphenylsulfonium ion, diphenyl[4-(phenylthio)phenyl]sulfonium ion, and tri-p-trylsulfonium ion (especially, triarylsulfonium ion).

Examples of the anionic portion of the photocationic polymerization initiator include BF ₄ ^- , B(C ₆ F ₅ ) ₄ ^- , PF ₆ ^- , [(Rf) _n PF _6-n ] ^- (Rf: 80% or more of hydrogen atoms) An alkyl group substituted with a fluorine atom (n: integer of 1 to 5), AsF ₆ ^- , SbF ₆ ^- , SbF ₅ OH ^-, etc. can be mentioned.

Examples of the photocationic polymerization initiator of the present invention include 4-(4-biphenylylthio)phenyl-4-biphenylylphenylsulfonium tetrakis(pentafluorophenyl)borate, 4-(4-biphenylyl) Thio)phenyl-4-biphenylylphenylsulfonium hexafluoroantimonate, diphenyl[4-(phenylthio)phenyl]sulfonium tetrakis(pentafluorophenyl)borate, diphenyl[4-(phenylthio) )Phenyl]sulfonium hexafluorophosphate, diphenyl[4-(phenylthio)phenyl]sulfonium tris(pentafluoroethyl)trifluorophosphate, 4-(4-biphenylylthio)phenyl-4-b Phenyllphenylsulfonium tris(pentafluoroethyl)trifluorophosphate, brand names “Cyracure UVI-6970”, “Cyracure UVI-6974”, “Cyracure UVI-6990”, “Cyracure UVI” -950” (above, manufactured by Union Carbide, USA), “Irgacure 250”, “Irgacure 261”, “Irgacure 264” (above, manufactured by BASF), “Optmer SP-150”, “Optmer” SP-151", "Optmer SP-170", "Optmer SP-171" (above, manufactured by ADEKA Co., Ltd.), "CG-24-61" (made by Ciba Japan), and "DAICAT II" (( (manufactured by Daicel Co., Ltd.), “UVAC1590”, “UVAC1591” (above, manufactured by Daicel/Cytech Co., Ltd.), “CI-2064”, “CI-2639”, “CI-2624”, “CI-2481”, “CI-2734”, “CI-2855”, “CI-2823”, “CI-2758”, “CIT-1682” (manufactured by Nippon Soda Co., Ltd.), “PI-2074” (manufactured by Rhodia, Tetra) Kiss (pentafluorophenyl borate) toluyl cumyl iodonium salt), “FFC509” (manufactured by 3M), “BBI-102”, “BBI-101”, “BBI-103”, “MPI-103”, “TPS” -103”, “MDS-103”, “DTS-103”, “NAT-103”, “NDS-103” (above, manufactured by Midori Chemical Co., Ltd.), “CD-1010”, “CD-1011” , “CD-1012” (made by Sartomer, USA), “CPI-100P”, and “CPI-101A” (made by San-Apro Co., Ltd.). These can be used individually or in combination of two or more types.

The usage amount (compounding amount) of component (B) is, for example, about 0.05 to 4 parts by weight, based on 100 parts by weight of the cationic curable compound (total amount when containing 2 or more types) contained in the sealing composition of the present invention. Preferably it is 0.2 to 2 parts by weight.

(Component (C))

The sealing composition of the present invention contains a glycoluril compound as component (C). Since the glycoluril compound exhibits weak basicity with respect to cations generated from the photo cationic polymerization initiator, it has the function of trapping cations generated from the photo cation polymerization initiator by light irradiation, and when heat treatment is performed after light irradiation Until then, the progress of hardening can be suppressed. In other words, it exerts a curing delay effect. Additionally, heat treatment after light irradiation releases trapped positive ions and has the effect of advancing curing of the sealing composition. Therefore, by adjusting the timing of heat treatment, the start of hardening can be controlled, and a situation in which bonding becomes difficult due to a delay in bonding work can be prevented. Glycoluril compounds can be used individually or in combination of two or more types.

Examples of the glycoluril compound in the present invention include a compound represented by the following formula (c).

In the formula (c), R ^a , R ^b , R ^c , and R ^d are the same or different, and two or more groups selected from hydrogen atoms, hydrocarbon groups, heterocyclic groups, and hydrocarbon groups and heterocyclic groups are a single bond or a linking group. Indicates the group combined through .

Examples of the linking group include a divalent hydrocarbon group, an alkenylene group in which part or all of the carbon-carbon double bond is epoxidized, a carbonyl group, an ether bond, an ester bond, a carbonate group, an amide group, and groups in which a plurality of these are connected, etc. can be mentioned.

The hydrocarbon group includes aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups bonded together through single bonds.

The aliphatic hydrocarbon group is preferably a C _1-20 aliphatic hydrocarbon group, for example, an alkyl group of C _1-20 (preferably C _1-10 , particularly preferably _{C 1-3} ); Alkenyl groups of about C _2-20 (preferably C _2-10 , particularly preferably C _2-3 ), such as vinyl and allyl groups; and an alkynyl group of about C _2-20 (preferably C _2-10 , particularly preferably C _2-3 ).

The alicyclic hydrocarbon group is preferably a C _3-20 alicyclic hydrocarbon group, for example, a cyclopentyl group, a cyclohexyl group, etc. C _3-20 (preferably C _3-15 , _particularly preferably C _{5- 8} ) cycloalkyl group; Cycloalkenyl groups of about C _3-20 (preferably C _3-15 , particularly preferably C _5-8 ) such as cyclopentenyl group and cyclohexenyl group; and cross-linked hydrocarbon groups such as norbornyl groups.

As the aromatic hydrocarbon group, a C _6-14 (especially C _6-10 ) aromatic hydrocarbon group is preferable, and examples include a phenyl group.

The heterocycles constituting the above heterocyclic group include aromatic heterocycles and non-aromatic heterocycles. Such heterocycles include a 3- to 10-membered ring (preferably a 3- to 6-membered ring) having a carbon atom and at least one hetero atom (for example, an oxygen atom, a sulfur atom, a nitrogen atom, etc.) as the atoms constituting the ring. , and condensed rings thereof. Specifically, heterocycles containing an oxygen atom as a hetero atom (e.g., oxirane ring, oxetane ring, furan ring, morpholine ring, etc.), heterocycles containing a sulfur atom as a hetero atom (e.g., thiophene ring, thiazole ring, etc.), heterocycle containing a nitrogen atom as a hetero atom (e.g., pyrrole ring, pyrrolidine ring, pyrazole ring, imidazole ring, triazole ring, isocyanuric ring, pyridine ring, pyridine ring) polyazine ring, pyrimidine ring, pyrazine ring, piperidine ring, piperazine ring, etc., indole ring, indoline ring, quinoline ring, acridine ring, naphthyridine ring, quinazoline ring, purine ring, etc.). A heterocyclic group is a group in which one hydrogen atom is removed from the structural formula of the above heterocyclic ring.

Examples of the group in which two or more groups selected from the hydrocarbon group and the heterocyclic group are bonded include a glycidyl group.

The hydrocarbon group, the heterocyclic group, and the group in which two or more groups selected from them are bonded may have various substituents [halogen atom, oxo group _{, hydroxyl group, substituted oxy group (for example, C 1-4 alkoxy} group, C _{6 - 10} aryloxy group, C _{7- 16} aralkyloxy group, C _{1- 4} acyloxy group, etc.), carboxyl group, substituted oxycarbonyl group (for example, C _{1- 4} alkoxycarbonyl group, C _{6- 10} aryloxycarbonyl group, C _{7- 16} aralkyloxycarbonyl group, etc.), substituted or unsubstituted carbamoyl group (e.g., carbamoyl, C _{1- 4} alkyl substituted carbamoyl, C _{6- 10} aryl substituted carbamoyl group), cyano group , nitro group, sulfo group, mercapto group, etc.]. Additionally, an aromatic or non-aromatic heterocycle may be condensed into the ring of the alicyclic hydrocarbon group or aromatic hydrocarbon group.

Among the above R ^a , R ^b , R ^c , and R ^d , it is preferable that they are, among others, a group containing a hydrogen atom or a group reactive with a cation-curable group (hereinafter sometimes referred to as a “reactive group”). The cation-curable group includes an alicyclic epoxy group, an oxetane ring-containing group, an episulfide group, and a vinyl ether group in component (A), and other epoxy groups, vinyl groups, and allyl groups in component (D), which will be described later. In the present invention, it is particularly preferable that two or more (particularly four) of R ^a , R ^b , R ^c , and R ^d are groups containing a reactive group (particularly, a glycidyl group or an allyl group).

As the glycoluril compound in the present invention, a glycoluril compound having a glycidyl group or an allyl group is preferable, and in particular two or more of R ^a , R ^b , R ^c , and R ^d in formula (c) (especially , 4) polyfunctional glycoluril compounds in which (4) are glycidyl groups and/or allyl groups are preferred.

As a glycoluril compound, for example, a glycoluril compound having a glycidyl group can be produced by reacting glycoluril with epichlorohydrin. In the present invention, for example, commercial products such as brand names “TA-G” and “TG-G” (above, manufactured by Shikoku Kasei Kogyo Co., Ltd.) can also be used.

The usage amount (compounding amount) of component (C) is, for example, 0.05 to 3 parts by weight with respect to 1 part by weight of component (B) (total amount if two or more types are contained) contained in the sealing composition of the present invention. , the upper limit is preferably 2.5 parts by weight, particularly preferably 2.0 parts by weight, and most preferably 1.5 parts by weight. The lower limit is preferably 0.1 part by weight, particularly preferably 0.3 part by weight, most preferably 0.5 part by weight, and particularly preferably 0.8 part by weight. It is preferable to contain the component (C) in the above range because a sufficient curing delay effect can be obtained. If the content of component (C) is below the above range, it tends to be difficult to obtain a sufficient curing delay effect. On the other hand, if the content of component (C) exceeds the above range, it tends to be difficult to obtain a sufficient curing speed even if heat treatment is performed, and curing failure may occur.

(Component (D))

The sealing composition of the present invention may contain, as component (D), one type or two or more types of cation-curable compounds other than the component (A).

Cationic curable compounds other than component (A) include, for example, compounds having an epoxy group other than component (A) (hereinafter sometimes referred to as “other epoxy compounds”), compounds having a vinyl group, compounds having an allyl group, etc. can be mentioned.

The other epoxy compounds include compounds in which an epoxy group is directly bonded to an alicyclic ring by a single bond, glycidyl ether-based epoxy compounds, glycidyl ester-based epoxy compounds, and glycidylamine-based epoxy compounds.

Examples of compounds in which an epoxy group is directly bonded to the alicyclic ring by a single bond include 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol ( Product name "EHPE3150", manufactured by Daicel Co., Ltd.), etc. can be mentioned.

Examples of the glycidyl ether-based epoxy compound include aliphatic glycidyl obtained by reacting epichlorohydrin with an aliphatic polyhydric alcohol such as 1,6-hexanediol diglycidyl ether and trimethylolpropane triglycidyl ether. Ether-based epoxy compounds; Bisphenol A type epoxy compound, bisphenol F type epoxy compound, bisphenol E type epoxy compound, o-phenylphenol glycidyl ether, biphenol type epoxy compound, phenol novolak type epoxy compound, cresol novolak type epoxy compound, bisphenol A aromatic glycidyl ether-based epoxy compounds such as cresol novolak-type epoxy compounds, naphthalene-type epoxy compounds, and trisphenolmethane-type epoxy compounds; Hydrogenated bisphenol A type epoxy compound (2,2-bis[4-(2,3-epoxypropoxy)cyclohexyl]propane, 2,2-bis[3,5-dimethyl-4-(2,3-epoxyprop) Compounds obtained by hydrogenating bisphenol A-type epoxy compounds such as (poxy)cyclohexyl]propane and their polymers), hydrogenated bisphenol F-type epoxy compounds (bis[o,o-(2,3-epoxypropoxy)cyclohexyl] Methane, bis[o,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[p,p-(2,3-epoxypropoxy)cyclohexyl]methane, bis[3,5-dimethyl- 4-(2,3-epoxypropoxy)cyclohexyl]methane, and their polymers, etc.), hydrogenated biphenol-type epoxy compounds, hydrogenated phenol novolak-type epoxy compounds, hydrogenated cresol novolac-type epoxy compounds, Alicyclic glycidyl ether epoxy compounds obtained by hydrogenating aromatic glycidyl ether epoxy compounds such as hydrogenated cresol novolac type epoxy compounds of bisphenol A, hydrogenated naphthalene type epoxy compounds, and hydrogenated trisphenolmethane type epoxy compounds. etc. can be mentioned. For example, product names “YL-983U” (manufactured by Mitsubishi Chemical Corporation), “R1710” (manufactured by Printec Co., Ltd.), “SY-OPG”, and “PEG” (above, Sakamoto Yakuhin Kogyo Co., Ltd.) Commercially available products such as (J) can be used.

Examples of the compound having the vinyl group include styrene-based compounds such as styrene, p-methylstyrene, ethylstyrene, propylstyrene, isopropylstyrene, and p-tert-butylstyrene; Nitrogen vinyl compounds, such as N-vinylcarbazole and N-vinylpyrrolidone, can be mentioned.

Examples of compounds having the allyl group include allyl (meth)acrylate, diallyl maleate, triallyl cyanurate, and diallyl phthalate.

In the present invention, especially since the curing rate at room temperature is slow, another epoxy compound (particularly preferably a compound having one or more glycidyl ether groups per molecule, most preferably one glycidyl ether group per molecule) is used. Using a compound that has at least one molecule and does not have an ester bond or polyether structure (excluding the compound included in component (A)) suppresses the generation of outgassing and more stabilizes the curing delay. It is preferable in that the desired effect is obtained.

The proportion of component (D) in the total amount (100% by weight) of the cationically curable compound contained in the sealing composition of the present invention is, for example, about 20 to 70% by weight, and the upper limit is preferably 65% by weight, especially Preferably it is 60% by weight. The lower limit is preferably 30% by weight, particularly preferably 40% by weight, and most preferably 50% by weight. It is preferable to contain component (D) in the above range because it can stabilize curing retardation.

In addition, component (A) and component (D) (particularly preferably compounds having one or more glycidyl ether groups per molecule, Most preferably, the ratio of the total amount of the compound (which has at least one glycidyl ether group per molecule and does not have an ester bond or polyether structure) is, for example, 50% by weight or more, preferably 70% by weight or more. , particularly preferably 80% by weight or more, and most preferably 90% by weight or more. Additionally, the upper limit is 100% by weight.

(additive)

In addition to the above components, the sealing composition of the present invention may contain one or two or more additives as needed. Examples of the additive include conductive materials, inorganic fillers, polymerization inhibitors, silane coupling agents, antioxidants, light stabilizers, plasticizers, leveling agents, anti-foaming agents, solvents, ultraviolet absorbers, ion absorbers, pigments, phosphors, mold release agents, etc. I can hear it.

When the sealing composition of the present invention requires higher moisture resistance, it is preferable to contain an inorganic filler. Examples of the inorganic filler include inorganic oxides such as silica, alumina, zinc oxide, and magnesium oxide; Carbonates such as calcium carbonate and magnesium carbonate; Silicates such as calcium silicate, glass beads, talc, clay, and mica can be mentioned.

The shape of the inorganic filler is not particularly limited, but includes, for example, spherical shape (spherical shape, approximately spherical shape, ellipsoidal shape, etc.), polyhedral shape, rod shape (cylindrical shape, prismatic shape, etc.), flat shape, scale shape, irregular shape. etc. can be mentioned. Among these, it is preferable to use a flat inorganic filler since it can provide better moisture resistance.

In the present invention, it is preferable to use silicates such as talc and mica because they have a linear response to the application pressure during dispensing and thus have excellent applicability.

The average particle diameter of the inorganic filler (based on laser diffraction/scattering method (microtrack method)) is, for example, 0.001 to 30 μm, preferably 0.1 to 10 μm.

The amount of the inorganic filler added is, for example, about 10 to 60 parts by weight, preferably 20 to 45 parts by weight, based on 100 parts by weight of the cationic curable compound contained in the sealing composition. Moisture resistance can be further improved by adding an inorganic filler in the above range. If the content of the inorganic filler exceeds the above range, the viscosity becomes too high and the applicability tends to decrease.

When conductivity is required for a sealing material, it is preferable that the sealing composition of the present invention contains a conductive material, and in particular, it is preferable to contain the following conductive fiber covering particles since it is possible to obtain a sealing material that has both conductivity and transparency. .

(Conductive fiber coated particles)

Conductive fiber-covered particles are conductive fiber-covered particles containing a particulate material and a fibrous conductive material (sometimes referred to as “conductive fiber” in this specification) covering the particulate material. In addition, in the case of conductive fiber-covered particles, “the conductive fiber covers the particulate matter” means a state in which the conductive fiber covers part or all of the surface of the particulate matter. As for conductive fiber-covered particles, conductive fibers may cover at least part of the surface of the particulate material, and for example, there may be more uncoated portions than covered portions. In addition, the particulate matter and the conductive fiber do not necessarily have to be in contact, but usually a part of the conductive fiber is in contact with the surface of the particulate matter.

Figure 1 is an example of a scanning electron microscope image of conductive fiber-covered particles in the present invention. As shown in FIG. 1, the conductive fiber-covered particles in the present invention have a configuration in which at least a part of particulate matter (spherical material in FIG. 1) is covered with conductive fiber (fibrous material in FIG. 1). has

(particulate matter)

The particulate matter constituting the conductive fiber covering particles in the present invention is a particulate structure.

The material constituting the particulate matter is not particularly limited, and examples include known and commonly used materials such as metal, plastic, rubber, ceramic, glass, and silica. In the present invention, it is preferable to use transparent materials such as transparent plastic, glass, and silica, and it is especially preferable to use transparent plastic.

The transparent plastic includes thermosetting resin and thermoplastic resin. Examples of the thermosetting resin include poly(meth)acrylate resin; polystyrene resin; polycarbonate resin; polyester resin; polyurethane resin; epoxy resin; polysulfone resin; Amorphous polyolefin resin; Divinylbenzene, hexatriene, divinyl ether, divinyl sulfone, diallylcarbinol, alkylene di(meth)acrylate, oligo or polyalkylene glycol di(meth)acrylate, alkylene tri(meth)acrylate , network polymers obtained by polymerizing polyfunctional monomers such as alkylene tetra(meth)acrylate, alkylene bis(meth)acrylamide, and both-terminal acrylic-modified polybutadiene oligomers alone or with other monomers; Examples include phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, and urea formaldehyde resin. Examples of the thermoplastic resin include ethylene/vinyl acetate copolymer, ethylene/vinyl acetate/unsaturated carboxylic acid copolymer, ethylene/ethyl acrylate copolymer, ethylene/methyl methacrylate copolymer, and ethylene/(meth)acrylic acid. Copolymer, ethylene/maleic anhydride copolymer, ethylene/aminoalkyl methacrylate copolymer, ethylene/vinylsilane copolymer, ethylene/glycidyl methacrylate copolymer, ethylene/hydroxyethyl methacrylate copolymer, Examples include methyl (meth)acrylate/styrene copolymer and acrylonitrile/styrene copolymer.

The shape of the particulate matter is not particularly limited, but includes, for example, spherical shape (spherical shape, approximately spherical shape, ellipsoidal shape, etc.), polyhedral shape, rod shape (cylindrical shape, prismatic shape, etc.), flat shape, scale shape, irregular shape. Shape, etc. can be mentioned. In the present invention, among others, the conductive fiber-covered particles can be manufactured with high productivity, can be easily dispersed uniformly in the sealing composition of the present invention, and can easily impart conductivity to the entire cured product. This is desirable.

The average aspect ratio of the particulate matter is not particularly limited, but is preferably less than 20 (for example, 1 or more, less than 20), and particularly preferably 1 to 10. If the average aspect ratio exceeds the above range, it may be difficult for the sealing composition of the present invention to exhibit excellent conductivity by mixing a small amount of conductive fiber covering particles. In addition, the average aspect ratio of the particulate matter is a sufficient number (e.g., 100 or more, preferably 300 or more; in particular, 100, 300) using, for example, an electron microscope (SEM, TEM). It can be measured by taking an electron microscope image of the particulate matter, measuring the aspect ratio of the particulate matter, and performing the arithmetic average.

In addition, the composition of the above-mentioned particulate matter is not particularly limited, and may be a single-layer structure or a multi-layer (multi-layer) structure. Additionally, the particulate matter may be any of solid particles, hollow particles, porous particles, etc.

The average particle diameter of the particulate matter is not particularly limited, but is preferably 0.1 to 100 μm, particularly preferably 1 to 50 μm, and most preferably 5 to 30 μm. If the average particle diameter is less than the above range, it may be difficult to exhibit excellent conductivity simply by mixing a small amount of conductive fiber-covered particles. When the average particle diameter exceeds the above range, the average particle diameter becomes larger than the thickness of the sealing layer of the organic EL element, and it tends to become difficult to form a coating film of uniform thickness. In addition, the average particle diameter of the above-mentioned particulate matter is the median diameter (d50) determined by the laser diffraction/scattering method.

The particulate matter is preferably transparent. Specifically, the total light transmittance of the particulate material in the visible light wavelength region is not particularly limited, but is preferably 70% or more, and particularly preferably 80% or more. If the total light transmittance is below the above range, the transparency of the cured product (including conductive fiber covering particles) may decrease.

In addition, the total light transmittance in the visible light wavelength range of the particulate material is obtained by polymerizing the monomer, which is the raw material of the particulate material, between glass in a temperature range of 80 to 150° C. to obtain a 1 mm thick plate, and obtaining a plate in the visible light wavelength range of the said plate. It is obtained by measuring the total light transmittance in accordance with JIS K7361-1. Additionally, the total light transmittance of only the glass is measured in the same way, and the obtained value is taken as the blank (total light transmittance 100%).

In addition, the particulate matter preferably has flexibility, and the 10% compressive strength of each particle is, for example, 10 kgf/mm2 or less, preferably 5 kgf/mm2 or less, and particularly preferably 3 kgf/mm2 or less. The conductive fiber-covered particles containing the particulate matter with a 10% compressive strength in the above range are deformed to follow the fine concavo-convex structure by pressing. Therefore, when the sealing composition of the present invention containing the conductive fiber covering particles is cured into a shape having a fine concave-convex structure, the particulate matter can spread to every detail, resulting in the occurrence of parts with poor conductivity. can be prevented.

The refractive index of the particulate matter is not particularly limited, but is preferably 1.4 to 2.7, and particularly preferably 1.5 to 1.8. In addition, when the particulate material is a plastic particle, the refractive index of the particulate material is determined by polymerizing the monomer, which is the raw material of the particulate material, between glass in a temperature range of 80 to 150°C, and cutting a test piece of 20 mm in length x 6 mm in width. , using monobromonaphthalene as an intermediate liquid, with the prism and the test piece in close contact, using a multi-wavelength Abbe refractometer (product name “DR-M2”, manufactured by Atago Co., Ltd.) at 25°C, at sodium D line. It can be obtained by measuring the refractive index.

In addition, the particulate matter preferably has a small difference in refractive index (at 25°C and a wavelength of 589.3 nm) from the cured product of the sealing composition of the present invention (excluding conductive fiber-covered particles), and the conductive fiber-covered particles The absolute value of the difference in refractive index of the cured product of the particulate matter constituting the sealing composition (excluding conductive fiber covering particles) of the present invention is, for example, 0.1 or less (preferably 0.05 or less, particularly preferably 0.02 or less). am.

That is, it is preferable that the conductive fiber covering particles contained in the composition for sealing an organic EL device of the present invention satisfy the following formula.

|Refractive index of particulate matter-Refractive index of the cured product of the composition for sealing organic EL elements (not including conductive fiber covering particles)|≤0.1

By setting the refractive index difference between the particulate matter constituting the conductive fiber covering particles and the cured product of the sealing composition of the present invention (not including the conductive fiber covering particles) within the above range, transparency is excellent and the haze is, for example, 10% or less. (Preferably 6% or less, more preferably 3% or less), and a total light transmittance of 90% or more (preferably 93% or more) can be obtained. Additionally, the haze of the cured product can be measured based on JIS K7136. In addition, the total light transmittance (thickness: 10 μm, wavelength: 450 nm) in the visible light wavelength range of the cured product can be measured based on JIS K7361-1.

In addition, it is preferable that the particulate matter constituting the conductive fiber covering particles in the present invention have a sharp particle size distribution (= small variation in particle diameter) because it can provide excellent conductivity with a smaller amount of use. And, it is preferable that the coefficient of variation (CV value) is 50% or less. Additionally, the coefficient of variation is a value obtained by dividing the standard deviation by the average particle diameter, and is a value that serves as an indicator of the uniformity of particle size.

The above-mentioned particulate matter can be manufactured by known or common methods, and the manufacturing method is not particularly limited. For example, in the case of metal particles, they can be manufactured by a vapor phase method such as CVD method or spray thermal decomposition method, or a wet method using a chemical reduction reaction. In addition, in the case of plastic particles, for example, a method of polymerizing the monomers constituting the resin (polymer) exemplified above by known polymerization methods such as suspension polymerization, emulsion polymerization, seed polymerization, and dispersion polymerization. It can be manufactured by etc.

In the present invention, commercial products can also be used. Particulate substances made of thermosetting resins include, for example, brand names “Techpolymer MBX Series”, “Techpolymer BMX Series”, “Techpolymer ABX Series”, “Techpolymer ARX Series”, and “Techpolymer AFX Series” (above, three (manufactured by Kisui Chemical Industry Co., Ltd.), brand names “Micropearl SP”, “Micropearl SI” (above, manufactured by Sekisui Chemical Industry Co., Ltd.); As a particulate material made of a thermoplastic resin, for example, the brand name "Soft Beads" (manufactured by Sumitomo Seika Co., Ltd.), the brand name "Duo Master" (manufactured by Sekisui Kasehin Kogyo Co., Ltd.), etc. can be used.

(Fibrous conductive material (conductive fiber))

The conductive fibers constituting the conductive fiber covering particles are fibrous structures (linear structures) that have conductivity. The shape of the conductive fiber may be fibrous (fibrous) and is not particularly limited, but its average aspect ratio is, for example, 10 or more, preferably 20 to 5000, particularly preferably 50 to 3000, and most preferably 100. It is from 1000. If the average aspect ratio is below the above range, it may be difficult to develop excellent conductivity simply by mixing a small amount of conductive fiber-covered particles. The average aspect ratio of the conductive fiber is obtained by the same method as the average aspect ratio of the particulate matter. In addition, the concept of “fiber shape” in the above-mentioned conductive fiber also includes the shapes of various linear structures such as “wire shape” and “rod shape.” Additionally, in this specification, fibers with an average thickness of 1000 nm or less may be referred to as “nanowires.”

The average thickness (average diameter) of the conductive fiber is not particularly limited, but is preferably 1 to 400 nm, particularly preferably 10 to 200 nm, and most preferably 50 to 150 nm. If the average thickness is less than the above range, the conductive fibers tend to aggregate with each other, and production of conductive fiber-covered particles may become difficult. On the other hand, if the average thickness exceeds the above range, it may become difficult to coat the particulate matter, and it may become difficult to efficiently produce conductive fiber-covered particles. The average thickness of the conductive fibers is measured using an electron microscope (SEM, TEM) for a sufficient number (e.g., 100 or more, preferably 300 or more; in particular, 100 or 300) of the conductive fibers. It is obtained by photographing mirror images, measuring the thickness (diameter) of these conductive fibers, and calculating the arithmetic average.

The average length of the conductive fiber is not particularly limited, but is preferably 1 to 100 μm, particularly preferably 5 to 80 μm, and most preferably 10 to 50 μm. If the average length is less than the above range, it becomes difficult to coat the particulate matter, and it may not be possible to efficiently manufacture conductive fiber-covered particles. On the other hand, when the average length exceeds the above range, the conductive fibers become easily entangled with each other. The average length of the conductive fibers is measured using an electron microscope (SEM, TEM) for a sufficient number (e.g., 100 or more, preferably 300 or more; in particular, 100 or 300) of the conductive fibers. It is obtained by photographing mirror images, measuring the length of their conductive fibers, and performing an arithmetic average. In addition, the length of the conductive fiber must be measured while stretched in a straight line, but in reality, many are bent, so the projection diameter and projection area of the conductive fiber are calculated from the electron microscope image using an image analysis device, It is calculated from the following equation assuming a cylindrical body.

Length=projected area/projected diameter

The material constituting the conductive fiber may be any material having conductivity, and examples include metal, semiconductor, carbon material, and conductive polymer.

Examples of the metal include known and commonly used metals such as gold, silver, copper, iron, nickel, cobalt, tin, and alloys thereof. In the present invention, silver is particularly preferable because it has excellent conductivity.

Examples of the semiconductor include known or commonly used semiconductors such as cadmium sulfide and cadmium selenide.

Examples of the carbon material include known and commonly used carbon materials such as carbon fiber and carbon nanotube.

Examples of the conductive polymer include polyacetylene, polyacene, polyparaphenylene, polyparaphenylenevinylene, polypyrrole, polyaniline, polythiophene, and derivatives thereof (e.g., alkyl groups and hydrocarbons in the common polymer backbone). Those having substituents such as roxyl group, carboxyl group, and ethylenedioxy group; specifically, polyethylenedioxythiophene, etc.) can be mentioned. In the present invention, among these, polyacetylene, polyaniline and its derivatives, polypyrrole and its derivatives, and polythiophene and its derivatives are preferred. In addition, the conductive polymer may contain known or common dopants (for example, acceptors such as halogens, halogenides, and Lewis acids; donors such as alkali metals and alkaline earth metals, etc.).

As the conductive fiber of the present invention, conductive nanowires are preferable, and in particular, at least one type of conductive nanowire selected from the group consisting of metal nanowires, semiconductor nanowires, carbon fibers, carbon nanotubes, and conductive polymer nanowires is preferable, In particular, silver nanowires are most desirable because of their excellent conductivity.

The above-mentioned conductive fiber can be manufactured by a known or customary manufacturing method. For example, the metal nanowire can be manufactured by a liquid phase method, a vapor phase method, etc. More specifically, silver nanowires are described, for example, in Mater.Chem.Phys. 2009, 114, 333-338] or the literature [Adv. Mater. 2002, 14, p833-837], [Chem. Mater. 2002, 14, p4736-4745] and Japanese Patent Publication No. 2009-505358. In addition, gold nanowires can be manufactured, for example, by the method described in Japanese Patent Application Laid-Open No. 2006-233252. In addition, copper nanowires can be manufactured, for example, by the method described in Japanese Patent Application Laid-Open No. 2002-266007. In addition, cobalt nanowires can be manufactured, for example, by the method described in Japanese Patent Application Laid-Open No. 2004-149871. In addition, semiconductor nanowires can be manufactured, for example, by the method described in Japanese Patent Application Laid-Open No. 2010-208925. The carbon fiber can be manufactured, for example, by the method described in Japanese Patent Application Laid-Open No. Hei 06-081223. The carbon nanotubes can be produced, for example, by the method described in Japanese Patent Application Laid-Open No. Hei 06-157016. The conductive polymer nanowire can be produced, for example, by the method described in Japanese Patent Application Laid-Open No. 2006-241334 and Japanese Patent Application Laid-Open No. 2010-76044. As the conductive fiber, it is also possible to use a commercially available product.

The conductive fiber-covered particles in the present invention can be produced by mixing the above-mentioned particulate matter and conductive fiber in a solvent. Specific examples of the method for producing conductive fiber-covered particles include the following methods (1) to (4).

(1) Mix the dispersion liquid in which the above-described particulate matter is dispersed in a solvent (referred to as “particle dispersion liquid”) and the dispersion liquid in which the above-mentioned conductive fibers are dispersed in a solvent (referred to as “fiber dispersion liquid”), and remove the solvent as necessary. , the conductive fiber-covered particles (or dispersion of conductive fiber-covered particles) in the present invention are obtained.

(2) The conductive fiber is mixed with the particle dispersion liquid, and after mixing, the solvent is removed as necessary to obtain conductive fiber-covered particles (or a dispersion liquid of conductive fiber-covered particles).

(3) After mixing and mixing the above-mentioned particulate matter with the above-mentioned fiber dispersion, the solvent is removed as necessary to obtain conductive fiber-covered particles (or a dispersion of conductive fiber-covered particles).

(4) After mixing and mixing the above-mentioned particulate matter and the above-mentioned conductive fiber in a solvent, the solvent is removed as necessary to obtain conductive fiber-covered particles (or a dispersion of conductive fiber-covered particles).

Examples of solvents used when producing the conductive fiber covering particles in the present invention include water; Alcohols such as methanol, ethanol, propanol, isopropanol, and butanol; Ketones such as acetone, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK); Aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; ethers such as diethyl ether, dimethoxyethane, tetrahydrofuran, and dioxane; esters such as methyl acetate, ethyl acetate, isopropyl acetate, and butyl acetate; Amides such as N,N-dimethylformamide and N,N-dimethylacetamide; Nitriles such as acetonitrile, propionitrile, and benzonitrile can be mentioned. These can be used individually or in combination of two or more types (that is, as a mixed solvent). In the present invention, alcohol and ketone are particularly preferable.

Additionally, if the cation-curable compound (component (A), etc.) is liquid, it is also possible to use it as a solvent. When a liquid curable compound is used as a solvent, a sealing composition containing the curable compound and conductive fiber covering particles can be obtained without going through a step of removing the solvent.

The viscosity of the solvent is not particularly limited, but from the viewpoint of efficiently producing conductive fiber-coated particles, the viscosity at 25°C is preferably 10 cP or less (for example, 0.1 to 10 cP), and particularly preferably. is 0.5 to 5 cP. In addition, the viscosity of the solvent at 25°C can be measured using, for example, an E-type viscometer (brand name "VISCONIC", manufactured by Tokimek Co., Ltd.) (rotor: 1°34'×R24, number of rotations: 0.5) rpm, measurement temperature: 25°C).

The boiling point of the solvent at 1 atm is preferably 200°C or lower, particularly preferably 150°C or lower, and most preferably 120°C or lower, since conductive fiber-coated particles can be efficiently produced.

When mixing particulate matter and conductive fiber in a solvent, the content of the particulate matter is, for example, about 0.1 to 50 parts by weight, preferably 1 to 30 parts by weight, based on 100 parts by weight of the solvent. By controlling the content of particulate matter within the above range, conductive fiber-coated particles can be produced more efficiently.

When mixing particulate matter and conductive fiber in a solvent, the content of the conductive fiber is, for example, about 0.1 to 50 parts by weight, preferably 1 to 30 parts by weight, based on 100 parts by weight of the solvent. By controlling the content of the conductive fiber within the above range, conductive fiber-covered particles can be produced more efficiently.

The ratio of the particulate material and the conductive fiber when mixing the particulate material and the conductive fiber in a solvent is such that the ratio of the surface area of the particulate material and the projected area of the conductive fiber [surface area/projected area] is, for example, 100/1 to 100/1. The ratio is preferably about 100/100, preferably 100/10 to 100/50. By controlling the ratio within the above range, conductive fiber-covered particles can be manufactured more efficiently. Additionally, the surface area of the particulate matter is obtained by multiplying the specific surface area obtained by the BET method (based on JIS Z8830) by the mass (amount used) of the particulate matter. In addition, the projected area of the conductive fibers is, as described above, a sufficient number (e.g., 100 or more, preferably 300 or more; in particular, 100, 300) using an electron microscope (SEM, TEM). It is obtained by taking electron microscope images of the conductive fibers, calculating the projected area of these conductive fibers using an image analysis device, and performing the arithmetic average.

By mixing the particulate matter and the conductive fiber and then removing the solvent, the conductive fiber-covered particles in the present invention can be obtained as a solid. Removal of the solvent is not particularly limited and can be performed, for example, by known or customary methods such as heating or distillation under reduced pressure. In addition, the solvent does not necessarily need to be removed, and can be used as is, for example, as a dispersion of conductive fiber-coated particles in the present invention.

As described above, the conductive fiber-covered particles in the present invention can be manufactured by mixing raw materials (particulate matter and conductive fiber) in a solvent, and do not require complicated processes, so they are advantageous in terms of manufacturing cost. In this way, what can be manufactured by a simple method of mixing in a solvent is that the fibrous conductive material used as the raw material (particularly, conductive fibers with an average aspect ratio of 10 or more) has a large surface energy and can be stabilized by lowering the surface energy. It is presumed that this is due to preferential attachment or adsorption to the particle surface.

In particular, as a combination of particulate matter and conductive fiber, particulate matter with an average particle diameter A [μm] and an average length A × 0.5 [μm] or more (preferably A × 1.0 [μm] or more, particularly preferably A × 1.5 By using conductive fibers ([μm] or more), the conductive fiber-covered particles in the present invention can be manufactured more efficiently. In particular, in the case of spherical or approximately spherical particulate matter, the particulate matter has an average circumferential length B [μm] and an average length (B×1/6) [μm] or more (preferably, B [μm] or more). It is preferable to use conductive fibers. In addition, the average circumferential length of the particulate matter is determined by measuring a sufficient number (e.g., 100 or more, preferably 300 or more; in particular, 100, 300, etc.) of the particulate matter using an electron microscope (SEM, TEM). It is obtained by taking electron microscope images, measuring the circumferential length of these particulate substances, and performing an arithmetic average.

The ratio of the particulate matter constituting the conductive fiber covering particles and the conductive fiber in the present invention is such that the ratio of the surface area of the particulate matter and the projected area of the conductive fiber [surface area/projected area] is, for example, 100/1 to 100/ A ratio of about 100 (particularly 100/10 to 100/50) is preferable because it can provide conductivity more efficiently while ensuring transparency of the cured product. In addition, the surface area of the particulate matter and the projected area of the conductive fiber are each obtained by the method described above.

Since the conductive fiber covering particles in the present invention have the above structure, excellent conductivity (particularly, conductivity in the thickness direction) can be imparted by adding a small amount to the sealing composition of the present invention, and the conductive fiber coating particles have excellent transparency and conductivity. Cargo can be formed.

In the case where the conductive fiber covering particles in the present invention have flexibility (for example, when the 10% compressive strength is 3 kgf/mm2 or less), the sealing composition containing the conductive fiber covering particles is formed into fine irregularities. When molded into a shape having a shape, the conductive fiber covering particles are deformed to follow the above-mentioned concave-convex structure and spread throughout the details, thereby preventing the occurrence of areas with poor conductivity and forming a cured product with excellent conductive performance. You can.

The content (blending amount) of the particulate matter (particulate matter contained in the conductive fiber-coated fine particles) in the sealing composition is, for example, about 0.09 to 6.0 parts by weight with respect to 100 parts by weight of the cationically curable compound. If the content of the particulate matter is below the above range, the conductivity of the obtained cured product may become insufficient depending on the application. On the other hand, when the content of the particulate matter exceeds the above range, the transparency of the obtained cured product tends to decrease.

The content of the above-mentioned particulate matter in the sealing composition is, for example, about 0.02 to 7% by volume with respect to the total amount (100% by volume) of the composition for sealing.

The content (compounding amount) of the conductive fiber in the sealing composition is, for example, about 0.01 to 1.0 parts by weight with respect to 100 parts by weight of the curable compound. If the content of the conductive fiber is less than the above range, the conductivity of the obtained cured product may become insufficient depending on the application. On the other hand, when the content of the conductive fiber exceeds the above range, the transparency of the obtained cured product tends to decrease.

The content of the conductive fiber in the sealing composition is, for example, 0.01 to 1.1% by volume with respect to the total amount (100% by volume) of the sealing composition.

The sealing composition of the present invention is prepared by mixing component (A), component (B), component (C) and, if necessary, component (D) and additives (for example, conductive fiber covering particles, etc.) with a magnetic rotating stirring degassing device, It can be manufactured by uniformly mixing using commonly known mixing devices such as a homogenizer, planetary mixer, three roll mill, and bead mill. In addition, each component may be mixed simultaneously or may be mixed in order.

The viscosity (25°C, shear rate: 20 (1/s)) of the sealing composition of the present invention (particularly when used as a filler material when sealing an organic EL element by the dam and fill method) is, for example, 10. to about 10000 mPa·s, preferably 20 to 3000 mPa·s, particularly preferably 30 to 2500 mPa·s, and most preferably 30 to 1000 mPa·s.

The sealing composition of the present invention can be cured by light irradiation and then heat treatment. For light irradiation, in the case of a coating film with a thickness of 100 μm, it is preferable to irradiate light of 500 mJ/cm 2 or more using a mercury lamp or the like. In addition, the heat treatment is performed in an oven or the like at, for example, 40 to 200°C (particularly preferably 60 to 180°C, most preferably 80 to 150°C) for 10 to 200 minutes (particularly preferably 30 to 120°C). minutes) It is desirable to heat it.

Since the sealing composition of the present invention contains the component (C), which has a cation trapping effect, even when light irradiation is applied, cations generated from the cationic polymerization initiator are trapped in the component (C), so heat treatment is performed after light irradiation. Until this is done, the progress of cationic polymerization is suppressed. In other words, a curing delay effect is exerted. Then, by performing heat treatment after light irradiation, cations trapped in component (C) are released, cationic polymerization of the cationic curable compound progresses, and curing can be completed. In other words, the progress of hardening can be arbitrarily controlled by adjusting the timing of heat treatment.

The viscosity (25°C, shear rate: 20 (1/s)) immediately after irradiating ultraviolet rays to the sealing composition of the present invention with a mercury lamp at 200 W/cm (irradiation amount: 2000 mJ/cm2) is, for example, 10 to 150,000 mPa. s or so, preferably 20 to 50,000 mPa·s, particularly preferably 30 to 30,000 mPa·s.

After irradiating ultraviolet rays to the sealing composition of the present invention with a mercury lamp at 200 W/cm (irradiation amount: 2000 mJ/cm2), the viscosity (25°C, shear rate: 20 (1/s)) for 30 minutes is, for example, 10 to 10. It is about 5000000 mPa·s, preferably 20 to 300000 mPa·s, particularly preferably 30 to 100000 mPa·s.

The viscosity increase from immediately after irradiation of ultraviolet rays to the sealing composition of the present invention with a mercury lamp of 200 W/cm (irradiation amount: 2000 mJ/cm2) until 30 minutes after irradiation is, for example, 10 times or less (e.g., 1 to 10 times ), preferably 8 times or less, more preferably 3 times or less, particularly preferably 2 times or less, and most preferably 1.5 times or less.

In addition, the cured product obtained by curing by the above method has low water vapor permeability (i.e., excellent moisture resistance), and the moisture permeability of the cured product (thickness: 100 μm) is, for example, 150 g/m2·day·atm or less, Preferably it is 100 g/m2·day·atm or less, particularly preferably 80 g/m2·day·atm or less, and most preferably 50 g/m2·day·atm or less. In addition, the above moisture permeability is a value measured under the conditions of 60°C and 90% RH for the moisture permeation of a cured product adjusted to a thickness of 100 μm in accordance with JIS L 1099 and JIS Z 0208.

In addition, the amount of outgassing derived from the curing retarder of the cured product (60 mg) obtained by curing by the above method is about 90ppm or less (preferably 70ppm or less, particularly preferably 50ppm or less), and shows low outgassing properties. Additionally, the amount of out gas can be measured by headspace GC/MS.

In addition, when the sealing composition of the present invention contains the above-mentioned conductive fiber covering particles, the cured product obtained by curing it has excellent conductivity and has an electrical resistivity (at 25° C. and 1 atm) of 0.1 Ω·cm to 10 MΩ·. cm, preferably 0.1Ω·cm to 1MΩ·cm.

The sealing composition of the present invention has a curing delay property and the curing start time can be arbitrarily adjusted. Therefore, by irradiating the sealing composition with light and then bonding it to an organic EL device and heating it, the organic EL device can be sealed without exposing the organic EL device to UV or making bonding difficult. In addition, the sealing composition of the present invention can form a cured product having low outgassing properties and moisture resistance. Therefore, the sealing composition of the present invention can be suitably used as a filler material when sealing an organic EL element by, for example, a dam and fill method. When the sealing composition of the present invention is used, the sealing composition of the present invention is protected from moisture and outgassing. The organic EL element can be protected, and deterioration of the organic EL element caused by moisture or outgassing can be prevented.

[Organic EL device]

The organic EL device of the present invention is an organic electroluminescent device provided with a cured product of the sealing composition of the present invention, and is obtained by sealing an organic EL element with the sealing composition of the present invention.

When the sealing composition of the present invention is used, the organic EL element (particularly, a top-emission organic EL element) can be sealed through the following process, thereby preventing deterioration of the element due to light irradiation, and sealing the element. An organic EL device with long life and high reliability can be provided. Additionally, the light irradiation and heat treatment methods can be performed by the above methods.

Step 1: Light irradiation is applied to a coating film made of the composition for sealing an organic EL device of the present invention.

Step 2: The light-irradiated coating film obtained through Step 1 is bonded to the device installation surface of the substrate on which the organic EL device is installed and subjected to heat treatment.

More specifically, methods for sealing the organic EL device of the present invention include methods 1 and 2 below.

<Method 1: See Figure 2>

Process 1-1: Applying the sealing composition of the present invention on the lead to form a coating film/lead laminate.

Process 1-2: Light irradiation on the paint film

Step 2-1: Install an organic EL device on a substrate, and attach the light-irradiated coating film/lead laminate to the organic EL device installation surface so that the coating surface faces the device installation surface.

Process 2-2: Curing the coating film by performing heat treatment

<Method 2>

Process 1-1': Applying the sealing composition of the present invention to the surface of release paper, etc. to form a sealing sheet or film.

Process 1-2': Light irradiation is performed on the sealing sheet or film.

Step 2-1: Install an organic EL element on a substrate, and bond the leads to the organic EL element installation surface through a sealing sheet or film after light irradiation.

Process 2-2: Curing the sealing sheet or film by heat treatment

As the lid (cover) or substrate, it is preferable to use a moisture-proof substrate, and examples include glass substrates such as soda glass and alkali-free glass; Metal substrates such as stainless steel and aluminum; Polyfluoroethylene polymers such as trifluoroethylene, polytrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), copolymer of PCTFE and PVDF, copolymer of PVDF and polyfluoroethylene, polyimide, poly Cycloolefin-based resins such as carbonate and dicyclopentadiene, polyesters such as polyethylene terephthalate, and resin base materials such as polyethylene and polystyrene. Additionally, the organic EL element is installed on the substrate and not on the lid (cover).

The organic EL device includes a laminate of an anode/light-emitting layer/cathode. If necessary, a passivation film such as a SiN film may be formed.

The coating film made of the sealing composition of the present invention can be formed, for example, by applying a dam material onto a lid (cover) to form a dam, and discharging the sealing composition of the present invention into the dam using a dispenser or the like. . The thickness of the coating film is not particularly limited as long as it is within a range that can achieve the purpose of protecting the element from moisture, etc.

In addition, when discharging the sealing composition containing conductive fiber-coated particles with a discharger such as a dispenser, it is preferable to discharge the conductive fiber-coated particles in a highly dispersed state in the sealing composition, for example, through a screw. It is preferable to discharge with stirring using a discharger having a rotational drive structure such as a screw discharge method in which the sealing composition is discharged by rotation of a screw. It is desirable to adjust the screw rotation speed, screw blade size, etc. appropriately depending on the viscosity of the sealing composition and the size of the conductive fiber covering particles contained therein.

According to the above method, the organic EL element can be sealed without exposure to UV, and the organic EL element does not have deterioration caused by exposure to UV. And, the organic EL element can be protected by sealing it with a cured material that has both low outgassing properties and moisture resistance. Therefore, the organic EL device obtained by sealing the organic EL element by the above method has a long life and is highly reliable.

Example

Below, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In addition, the viscosity is the viscosity measured using a rheometer (brand name "Physica MCR301", manufactured by Anton Paar) at 25°C and a shear rate of 20 (1/s).

Example 1

According to the prescription shown in the table, each component was placed in a rotation/revolution mixer (brand name "Awatori Rentaro ARE 310", manufactured by Shinki Co., Ltd.) and stirred to obtain a sealing composition (1).

The obtained sealing composition (1) was applied on a glass substrate to form a coating film (1) (thickness: 100 μm), and ultraviolet rays were irradiated with a mercury lamp (irradiation amount: 1600 mJ/cm2). The viscosity was measured before ultraviolet irradiation, immediately after ultraviolet irradiation, and 30 minutes after ultraviolet irradiation, and the viscosity increase between immediately after ultraviolet irradiation and 30 minutes after ultraviolet irradiation was calculated from the equation below.

Viscosity increase = Viscosity for 30 minutes after UV irradiation/Viscosity immediately after UV irradiation

Thereafter, the coating film (1) after irradiation with ultraviolet rays was heated at 100°C for 1 hour to obtain the cured product (1) (post-curing).

The obtained cured product (1) was evaluated for outgassing amount and water vapor permeability by the following methods.

Examples 2 to 9, Comparative Examples 1 to 5

A sealing composition was obtained in the same manner as in Example 1 except that the prescription was changed as shown in the table, a coating film was obtained, and a cured product was obtained. Additionally, in Example 6, the temperature of post-curing was changed to 150°C.

The obtained cured product was evaluated for outgassing amount and water vapor permeability by the following methods.

<Out gas amount>

The amount of outgassing (unit: ppm) derived from the curing retardant of the cured products obtained in the examples and comparative examples was obtained by placing 60 mg of the cured product in a vial bottle, irradiating it with UV light (2000 mJ/cm2), and leaving it to stand for 1 hour under conditions of 100°C. The amount of outgassed in the vial was measured. In addition, a calibration curve was prepared using toluene standard solution [toluene as a standard material: 100 ppm, hexane as a solvent: 60 mg]. In addition, as a measuring instrument, the brand name "HP-6890N" (manufactured by Hewlett-Packard) was used, and as a column, the brand name "DB-624" (manufactured by Agilent) was used.

<Water vapor permeability>

The water vapor permeability of the cured products obtained in the examples and comparative examples was determined by measuring the moisture permeability (g/m2·day·atm) of the cured product (thickness: 100 ㎛) at 60°C according to JIS L 1099 and JIS Z 0208 (cup method). , was measured and evaluated under 90% RH conditions.

The compounds used in the examples and comparative examples are as follows.

(Cationic curable compound)

a-1: (3,4,3',4'-diepoxy)bicyclohexyl

a-2: Bis(3,4-epoxycyclohexylmethyl)ether

a-3: 4,4'-bis[(3-ethyl-3-oxetanyl)methoxymethyl]biphenyl, brand name "ETERNACOLL OXBP", manufactured by Ube Kosan Co., Ltd.

a-4: Episulfide-terminated fluorene compound, brand name “CS-500”, manufactured by Osaka Gas Chemical Co., Ltd.

a-5: Oxynorbornene divinyl ether, brand name “ONB-DVE”, manufactured by Daicel Co., Ltd.

(Photocationic polymerization initiator)

b-1: 4-(4-biphenylylthio)phenyl-4-biphenylylphenylsulfonium tetrakis(pentafluorophenyl)borate

b-2: Diphenyl[4-(phenylthio)phenyl]sulfonium tris(pentafluoroethyl)trifluorophosphate

b-3: 4-(4-biphenylylthio)phenyl-4-biphenylylphenylsulfonium hexafluoroantimonate

(curing retardant)

c-1: 1,3,4,6-tetraglycidyl glycoluril, brand name “TG-G”, manufactured by Shikoku Chemical Industry Co., Ltd.

c-2: 1,3,4,6-tetraallylglycoluril, brand name “TA-G”, manufactured by Shikoku Chemical Industry Co., Ltd.

c-3: Crown ether, brand name “18-Crown-6”, manufactured by Nippon Soda Co., Ltd.

c-4: Bisphenol A bis(triethylene glycol glycidyl ether) ether, brand name “Lika Resin BEO 60E”, manufactured by Nippon Rika Co., Ltd.

c-5: 1,3,5-tris(4,5-epoxypentyl)-1,3,5-triazine-2,4,6-trione, brand name “TEPIC-VL”, Nissan Chemical Industries, Ltd. ( subject

(Other cationically curable compounds)

d-1: Liquid bisphenol F diglycidyl ether, brand name “YL-983U”, manufactured by Mitsubishi Chemical Corporation

d-2: Bisphenol E diglycidyl ether, brand name “R1710”, manufactured by Printec Co., Ltd.

d-3: o-phenylphenol glycidyl ether, brand name “SY-OPG”, manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.

The composition for sealing organic EL devices of the present invention can suppress the progress of curing until heat treatment is performed even when UV is irradiated to the coating film, and even if the progress of the bonding operation is delayed, adhesiveness is lost and bonding is difficult. There is no termination. Also, curing can be advanced by heat treatment after bonding, and the organic EL element can be sealed without being directly exposed to UV. In addition, the composition for sealing an organic EL device of the present invention has moisture resistance and can form a cured product with low outgassing properties, thereby preventing deterioration of the organic EL device due to moisture or outgassing.

Therefore, the composition for sealing organic EL devices of the present invention or the sheet or film made of the composition for sealing organic EL devices of the present invention can be suitably used for sealing top-emission type organic EL devices.

1: lead
2: dam
3: Dispenser
4: Composition for sealing
5: substrate
6: cathode
7: Light-emitting layer
8: anode

Claims (9)

A composition for sealing an organic electroluminescent device containing the following components (A), (B), and (C),
The amount of component (B) used is 0.05 to 4 parts by weight based on 100 parts by weight of the cationically curable compound contained in the sealing composition, and 0.05 to 3 parts by weight of component (C) is contained per 1 part by weight of component (B). A composition for sealing an organic electroluminescence device.
Component (A): A cationic curable compound having two or more groups per molecule, one or more groups selected from alicyclic epoxy groups, oxetane ring-containing groups, episulfide groups, and vinyl ether groups.
Component (B): Photocationic polymerization initiator
Ingredient (C): Glycoluril Compound The composition for sealing an organic electroluminescence device according to claim 1, wherein component (C) is a glycoluril compound containing a glycidyl group or an allyl group. The composition for sealing an organic electroluminescence device according to claim 1 or 2, further comprising the following component (D).
Component (D): Compounds having one or more glycidyl ether groups per molecule (excluding compounds included in component (A)) The composition for sealing an organic electroluminescent device according to claim 1 or 2, further comprising an inorganic filler having an average particle diameter of 0.001 to 30 μm. The composition for sealing an organic electroluminescence device according to claim 1 or 2, further comprising the following conductive fiber covering particles.
Conductive fiber covering particles: Conductive fiber covering particles containing a particulate material and a fibrous conductive material covering the particulate material. The composition for sealing organic electroluminescent devices according to claim 1 or 2, which is used for sealing top-emission type organic electroluminescent devices. A method of manufacturing an organic electroluminescent device, characterized in that the organic electroluminescent device is sealed through the following steps 1 and 2.
Step 1: Light irradiation is applied to a coating film made of the composition for sealing an organic electroluminescent element according to claim 1 or 2.
Step 2: The light-irradiated coating film obtained through Step 1 is bonded to the device installation surface of the substrate on which the organic electroluminescence device is installed and subjected to heat treatment. An organic electroluminescent device comprising a cured product of the composition for sealing an organic electroluminescent element according to claim 1 or 2. delete