阅读说明：本技术 有机el显示元件用密封剂 (Sealing agent for organic EL display element ) 是由 赤松范久 山本拓也 梁信烈 七里德重 于 2017-10-18 设计创作，主要内容包括：本发明的目的在于,提供能够通过喷墨法来容易地涂布、低脱气性优异、且能够获得耐弯曲性优异的固化物的有机EL显示元件用密封剂。本发明是一种有机EL显示元件用密封剂,其含有聚合性化合物和聚合引发剂,所述有机EL显示元件用密封剂在25℃时的粘度为5～50mPa·s,在25℃时的表面张力为15～35mN/m,固化物在25℃时的泊松比为0.28～0.40。(The purpose of the present invention is to provide a sealing agent for an organic EL display element, which can be easily applied by an ink jet method, has excellent low outgassing properties, and can provide a cured product having excellent bending resistance. The present invention is a sealing agent for an organic EL display element, which contains a polymerizable compound and a polymerization initiator, and which has a viscosity of 5 to 50 mPas at 25 ℃, a surface tension of 15 to 35mN/m at 25 ℃, and a Poisson's ratio of a cured product of 0.28 to 0.40 at 25 ℃.)

1. A sealing agent for an organic EL display element, characterized by containing a cationically polymerizable compound and a polymerization initiator,

the cationic polymerizable compound is at least one selected from the group consisting of an epoxy compound, an oxetane compound and a vinyl ether compound,

the sealant for organic EL display elements has a viscosity of 5 to 50 mPas at 25 ℃, a surface tension of 15 to 35mN/m at 25 ℃, and a Poisson's ratio of a cured product at 25 ℃ of 0.28 to 0.40.

2. The sealing agent for an organic EL display element according to claim 1, wherein a cured product has a Young's modulus at 25 ℃ of 1500MPa to 5000 MPa.

3. The sealing agent for an organic EL display element according to claim 1 or 2, wherein the cationically polymerizable compound contains an alicyclic epoxy resin.

4. Use of the sealing agent for an organic EL display element according to any one of claims 1 to 3 for coating by an inkjet method.

Technical Field

The present invention relates to a sealing agent for an organic EL display element, which can be easily applied by an ink jet method, has excellent low outgassing properties, and can provide a cured product having excellent bending resistance.

Background

An organic electroluminescence (hereinafter also referred to as "organic EL") display element has a laminate structure in which an organic light emitting material layer is sandwiched between a pair of electrodes facing each other, and electrons are injected from one electrode into the organic light emitting material layer and holes are injected from the other electrode into the organic light emitting material layer, whereby the electrons and the holes are combined in the organic light emitting material layer and light is emitted. Since the organic EL display element emits light in this manner, the organic EL display element has the following advantages as compared with a liquid crystal display element or the like that requires a backlight: the device has good visibility, can be thinned, and can be driven by DC low voltage.

The organic light-emitting material layer and the electrode constituting the organic EL display device have a problem that their characteristics are easily deteriorated by moisture, oxygen, or the like. Therefore, in order to obtain a practical organic EL display element, it is necessary to isolate the organic light-emitting material layer and the electrode from the atmosphere to achieve a long life. Patent document 1 discloses a method of sealing an organic light emitting material layer and an electrode of an organic EL display element with a laminated film of a silicon nitride film and a resin film formed by a CVD method. Here, the resin film has an effect of preventing the organic layer and the electrode from being pressed by the internal stress of the silicon nitride film.

In the method of sealing with a silicon nitride film disclosed in patent document 1, the organic light emitting material layer and the electrode may not be completely covered when the silicon nitride film is formed due to irregularities on the surface of the organic EL display element, adhesion of foreign matter, occurrence of cracks due to internal stress, and the like. If the coverage based on the silicon nitride film is incomplete, moisture penetrates into the organic light emitting material layer through the silicon nitride film.

As a method for preventing moisture from entering into the organic light emitting material layer, patent document 2 discloses a method of alternately depositing an inorganic material film and a resin film, and patent documents 3 and 4 disclose a method of forming a resin film on an inorganic material film.

As a method for forming a resin film, there is a method in which a sealant is applied to a substrate by an ink jet method and then cured. If a coating method based on such an ink jet method is used, a resin film can be uniformly formed at high speed. However, when the viscosity of the sealing agent is reduced to make it suitable for application by an ink jet method, there is a problem that degassing is likely to occur. Further, when the conventional sealing agent is used, there are the following problems: a cured product of the sealing agent may crack or peel due to bending or the like during use, and the penetration of moisture cannot be sufficiently prevented, which may deteriorate the reliability of the obtained organic EL display device.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2000-223264

Patent document 2: japanese Kohyo publication No. 2005-522891

Patent document 3: japanese patent laid-open publication No. 2001-307873

Patent document 4: japanese patent laid-open No. 2008-149710

Disclosure of Invention

Problems to be solved by the invention

The purpose of the present invention is to provide a sealing agent for an organic EL display element, which can be easily applied by an ink jet method, has excellent low outgassing properties, and can provide a cured product having excellent bending resistance.

Means for solving the problems

The present invention 1 is a sealing agent for an organic EL display element, which contains a polymerizable compound and a polymerization initiator, and which has a viscosity of 5 to 50 mPas at 25 ℃, a surface tension of 15 to 35mN/m at 25 ℃, and a Poisson's ratio of a cured product at 25 ℃ of 0.28 to 0.40.

The present invention 2 is a sealing agent for an organic EL display element, which is used for coating by an inkjet method, and which contains a polymerizable compound and a polymerization initiator, and the poisson's ratio of a cured product at 25 ℃ is 0.28 to 0.40.

The present invention is described in detail below. The sealant for an organic EL display element of the present invention is referred to as a "sealant for an organic EL display element of the present invention" for the common matters between the sealant for an organic EL display element of the present invention 1 and the sealant for an organic EL display element of the present invention 2.

The present inventors have further studied to make the poisson's ratio of a cured product at 25 ℃ within a specific range for a sealant for an organic EL display element having excellent inkjet coatability. As a result, they found that: the present inventors have completed the present invention by obtaining a sealing agent for an organic EL display element, which can be easily applied by an ink jet method, has excellent low outgassing properties, and can give a cured product having excellent bending resistance.

The sealing agent for an organic EL display element of the present invention can be applied by a non-heating type ink jet method or by a heating type ink jet method as an ink jet method.

In the present specification, the "non-heating type ink jet method" is a method of performing ink jet coating at a coating head temperature of less than 28 ℃, and the "heating type ink jet method" is a method of performing ink jet coating at a coating head temperature of 28 ℃ or higher.

The heating type ink jet method may use an ink jet coating head equipped with a heating mechanism. By mounting the heating mechanism on the inkjet application head, viscosity and surface tension can be reduced when the sealing agent for the organic EL display element is discharged.

Examples of the inkjet coating head equipped with the heating mechanism include KM1024 series manufactured by KONICAMINOLTA corporation; SG1024 series manufactured by Fuji Film Dimatix, Inc., and the like.

When the sealant for an organic EL display element of the present invention is used for the application by the heating inkjet method, the heating temperature of the application head is preferably in the range of 28 to 80 ℃. When the heating temperature of the coating head is in this range, the viscosity of the sealant for an organic EL display element is prevented from increasing with time, and the discharge stability is further improved.

The lower limit of the viscosity of the sealant for an organic EL display element of the present invention 1 is 5mPa · s, and the upper limit of the viscosity is 50mPa · s. When the viscosity is in this range, the coating can be favorably performed by an ink jet method.

In the present specification, the viscosity is a value measured by using an E-type viscometer at 25 ℃ and 100 rpm.

The viscosity of the sealant for an organic EL display element of the present invention when applied by the non-heating inkjet method has a preferred lower limit of 5mPa · s and a preferred upper limit of 20mPa · s. When the viscosity is in this range, the ink can be favorably applied by a non-heating type ink jet method. The viscosity of the organic EL display element sealing agent of the present invention when applied by the non-heating inkjet method is more preferably 8mPa · s at the lower limit, more preferably 16mPa · s at the upper limit, even more preferably 10mPa · s at the lower limit, and even more preferably 13mPa · s at the upper limit.

On the other hand, the viscosity of the organic EL display element sealing agent of the present invention used for the application by the heating inkjet method has a preferable lower limit of 10mPa · s and a preferable upper limit of 50mPa · s. When the viscosity is in this range, the coating can be favorably performed by the heating inkjet method. The viscosity of the organic EL display element sealing agent of the present invention used for the application by the heating inkjet method has a more preferable lower limit of 20mPa · s and a more preferable upper limit of 40mPa · s.

The lower limit of the surface tension of the sealing agent for an organic EL display element of the present invention 1 is 15mN/m, and the upper limit is 35 mN/m. When the surface tension is in this range, the coating can be favorably performed by an ink jet method. The surface tension preferably has a lower limit of 20mN/m, a preferred upper limit of 30mN/m, a more preferred lower limit of 22mN/m, and a more preferred upper limit of 28 mN/m.

The lower limit of the surface tension of the sealing agent for an organic EL display element of the present invention 2 is preferably 15mN/m, and the upper limit is preferably 35 mN/m. When the surface tension is in this range, the coating can be favorably performed by an ink jet method. The surface tension is more preferably 20mN/m in lower limit, more preferably 30mN/m in upper limit, still more preferably 22mN/m in lower limit, and still more preferably 28mN/m in upper limit.

The surface tension is a value measured by the Wilhelmy method at 25 ℃ using a dynamic wettability tester.

The cured product of the sealing agent for an organic EL display element of the present invention has a Poisson's ratio at 25 ℃ of 0.28 as the lower limit and 0.40 as the upper limit. By setting the poisson's ratio to 0.28 or more, the effect of preventing the occurrence of cracks when the cured product is bent is excellent. By setting the poisson's ratio to 0.40 or less, the effect of preventing the cured product from warping or the like becomes excellent. The poisson's ratio preferably has a lower limit of 0.30, a preferable upper limit of 0.36, a more preferable lower limit of 0.33, and a more preferable upper limit of 0.35.

In the present specification, the poisson's ratio is: a ratio of a strain in a direction of an applied force to a strain in a direction orthogonal to the direction of the applied force when the object is elastically deformed by applying the force in the uniaxial direction. The poisson ratio can be determined as follows: the length before elastic deformation in the direction of the applied force is denoted by p, the length change amount due to elastic deformation in the direction of the applied force is denoted by Δ p, the length before elastic deformation in the direction orthogonal to the direction of the applied force is denoted by r, and the length change amount due to elastic deformation in the direction orthogonal to the direction of the applied force is denoted by Δ r.

Poisson ratio (Δ r/r)/(Δ p/p)

Further, if the cured product for the measurement of the Poisson's ratio is a photocurable sealant, it can be measured, for example, by using an LED lamp at 3000mJ/cm²The sealant is obtained by irradiating the sealant with ultraviolet rays having a wavelength of 365nm, and in the case of a thermosetting sealant, it can be obtained by heating at 80 ℃ for 1 hour, for example.

The cured product of the sealing agent for an organic EL display element has a Young's modulus at 25 ℃ of 1500MPa at the lower limit and 5000MPa at the upper limit. When the young's modulus is in this range, the effect of preventing the occurrence of cracks when the cured product is bent is further excellent. The Young's modulus preferably has a lower limit of 2700MPa and an upper limit of 4000MPa, more preferably has a lower limit of 3000MPa and an upper limit of 3500 MPa.

In the present specification, the young's modulus means: values measured under the conditions of 25 ℃ at 50% RH and an inter-jig distance of 100mm according to the method of JIS K7127-1989.

Further, if the cured product for measuring the Young's modulus is a photocurable sealant, it can be measured, for example, by using an LED lamp at 3000mJ/cm²The sealant is obtained by irradiating the sealant with ultraviolet rays having a wavelength of 365nm, and in the case of a thermosetting sealant, it can be obtained by heating at 80 ℃ for 1 hour, for example.

The viscosity, the surface tension, the poisson's ratio, and the young's modulus can be set to the above ranges by selecting the type of polymerizable compound, polymerization initiator, and other components optionally contained, which will be described later, and adjusting the content ratio.

The sealant for an organic EL display element of the present invention contains a polymerizable compound.

As the polymerizable compound, a radical polymerizable compound or a cation polymerizable compound can be used. Among them, radical polymerizable compounds are preferable.

The radical polymerizable compound is preferably a (meth) acrylic compound.

The (meth) acrylic compound may be a monofunctional (meth) acrylic compound, may be a polyfunctional (meth) acrylic compound, and may be used in combination with the polyfunctional (meth) acrylic compound.

In the present specification, the "(meth) acrylic" refers to an acrylic or methacrylic, the "(meth) acrylic compound" refers to a compound having a (meth) acryloyl group, and the "(meth) acryloyl group" refers to an acryloyl group or a methacryloyl group.

The monofunctional (meth) acrylic compound preferably has a cationically polymerizable group from the viewpoint of low outgassing property and the like.

Examples of the cationically polymerizable group include a vinyl ether group, an epoxy group, an oxetane group, an allyl ether group, a vinyl group, and a hydroxyl group.

Specific examples of the monofunctional (meth) acrylic compound include 3, 4-epoxycyclohexylmethyl (meth) acrylate, glycidyl (meth) acrylate, 4-hydroxybutyl glycidyl (meth) acrylate, 2- (2-vinyloxyethoxy) ethyl (meth) acrylate, 3-ethyl-3- (meth) acryloyloxymethyloxetane, allyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, ethoxytriethylene glycol (meth) acrylate, and 2- (2-vinyloxyethoxy) ethyl (meth) acrylate. Among them, 3, 4-epoxycyclohexylmethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, and 2- (2-ethyleneoxyethoxy) ethyl (meth) acrylate are preferable.

In the present specification, the "(meth) acrylate" refers to an acrylate or a methacrylate.

When the polymerizable compound contains the monofunctional (meth) acrylic compound, the content of the monofunctional (meth) acrylic compound in 100 parts by weight of the polymerizable compound preferably has a lower limit of 20 parts by weight and an upper limit of 80 parts by weight. When the content of the monofunctional (meth) acrylic compound is in this range, the obtained sealant for an organic EL display element is more excellent in low outgassing property and the like. The content of the monofunctional (meth) acrylic compound has a more preferable lower limit of 30 parts by weight and a more preferable upper limit of 60 parts by weight.

From the viewpoint of ink-jet coatability and the like, the polyfunctional (meth) acrylic compound preferably has a polyoxyalkylene skeleton in the main chain.

The polyoxyalkylene skeleton is preferably a skeleton in which 2 to 6 oxyalkylene units are connected in series.

Examples of the oxyalkylene unit constituting the polyoxyalkylene skeleton include an oxyethylene unit and an oxypropylene unit.

From the viewpoint of ink-jet coatability and the like, the polyfunctional (meth) acrylic compound is preferably a structure having a carbon chain with few branches, and more preferably a linear structure.

Specific examples of the polyfunctional (meth) acrylic compound include diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, and the like. Among them, tetrapropylene glycol di (meth) acrylate is preferable.

When the polymerizable compound contains the polyfunctional (meth) acrylic compound, the lower limit of the content of the polyfunctional (meth) acrylic compound in 100 parts by weight of the polymerizable compound is preferably 20 parts by weight, and the upper limit is preferably 80 parts by weight. When the content of the polyfunctional (meth) acrylic compound is in this range, the obtained sealing agent for an organic EL display element is more excellent in ink jet coatability and the like. The content of the polyfunctional (meth) acrylic compound has a more preferable lower limit of 30 parts by weight and a more preferable upper limit of 60 parts by weight.

When the monofunctional (meth) acrylic compound and the polyfunctional (meth) acrylic compound are used in combination, the content ratio of the monofunctional (meth) acrylic compound to the polyfunctional (meth) acrylic compound is preferably 7:3 to 3:7 in terms of a weight ratio, based on the monofunctional (meth) acrylic compound to the polyfunctional (meth) acrylic compound. By setting the content ratio of the monofunctional (meth) acrylic compound to the polyfunctional (meth) acrylic compound in this range, the obtained sealing agent for an organic EL display element can be made more excellent in ink jet coatability and the like. The content ratio of the monofunctional (meth) acrylic compound to the polyfunctional (meth) acrylic compound is more preferably 6:4 to 4:6 in terms of a weight ratio, the monofunctional (meth) acrylic compound being a polyfunctional (meth) acrylic compound.

Examples of the cationically polymerizable compound include an epoxy compound, an oxetane compound, and a vinyl ether compound.

Examples of the above epoxy compound include bisphenol A type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol O type epoxy resin, 2' -diallylbisphenol A type epoxy resin, alicyclic epoxy resin, hydrogenated bisphenol type epoxy resin, propylene oxide-adduct bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, thioether type epoxy resin, diphenylether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, phenol novolak type epoxy resin, O-cresol novolak type epoxy resin, dicyclopentadiene novolak type epoxy resin, biphenol novolak type epoxy resin, naphthol novolak type epoxy resin, glycidyl amine type epoxy resin, alkyl polyhydric alcohol type epoxy resin, rubber-modified epoxy resin, Glycidyl ester compounds, epoxy-modified organopolysiloxanes, and the like. Among them, an alicyclic epoxy resin is preferable.

Examples of commercially available products among the alicyclic epoxy resins include, for example, CELLOXIDE 2000, CELLOXIDE 2021P, CELLOXIDE 2081, CELLOXIDE 3000, CELLOXIDE 8000 (all manufactured by Daiiluo corporation); sansocizer EPS (manufactured by Nissi electronics Co., Ltd.), and the like.

Examples of the oxetane compound include allyloxybutone, phenoxymethyloxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3- (phenoxymethyl) oxetane, 3-ethyl-3- ((2-ethylhexyloxy) methyl) oxetane, 3-ethyl-3- ((3- (triethoxysilyl) propoxy) methyl) oxetane, 3-ethyl-3- (((3-ethyloxetan-3-yl) methoxy) methyl) oxetane, oxetanylsilsesquioxane, phenol novolac oxetane, 1, 4-bis (((3-ethyl-3-oxetanyl) methoxy) methyl) benzene, and the like.

Examples of the vinyl ether compound include benzyl vinyl ether, cyclohexanedimethanol monovinyl ether, dicyclopentadiene vinyl ether, 1, 4-butanediol divinyl ether, cyclohexanedimethanol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, dipropylene glycol divinyl ether, tripropylene glycol divinyl ether, and the like.

The sealing agent for an organic EL display element of the present invention contains a polymerization initiator.

As the polymerization initiator, a photo radical polymerization initiator, a thermal radical polymerization initiator, a photo cation polymerization initiator, and a thermal cation polymerization initiator can be suitably used depending on the kind of the polymerizable compound used, and the like.

Examples of the photo radical polymerization initiator include benzophenone-based compounds, acetophenone-based compounds, acylphosphine oxide-based compounds, titanocene-based compounds, oxime ester-based compounds, benzoin ether-based compounds, benzil, and thioxanthone-based compounds.

Examples of commercially available products among the photo radical polymerization initiators include IRGACURE184, IRGACURE369, IRGACURE379, IRGACURE651, IRGACURE819, IRGACURE907, IRGACURE2959, IRGACURE OXE01, and Lucirin TPO (both manufactured by BASF); benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether (all manufactured by Tokyo chemical industries Co., Ltd.), and the like.

Examples of the thermal radical polymerization initiator include thermal radical polymerization initiators formed from azo compounds, organic peroxides, and the like.

Examples of the azo compound include 2, 2' -azobis (2, 4-dimethylvaleronitrile), azobisisobutyronitrile, and the like.

Examples of the organic peroxide include benzoyl peroxide, ketone peroxide, peroxyketal, hydrogen peroxide, dialkyl peroxide, peroxyester, diacyl peroxide, and peroxydicarbonate.

Examples of commercially available products among the thermal radical polymerization initiators include VPE-0201, VPE-0401, VPE-0601, VPS-0501, VPS-1001 and V-501 (all manufactured by Wako pure chemical industries).

The photo cation polymerization initiator is not particularly limited as long as it generates a protonic acid or a lewis acid by light irradiation, and may be an ionic photo acid type or a nonionic photo acid type.

Examples of the anionic moiety of the above-mentioned ionic photoacid generator type photocationic polymerization initiator include BF₄ ^-、PF₆ ^-、SbF₆ ^-Or (BX)₄)^-(wherein X represents a phenyl group substituted with at least 2 or more fluorine or trifluoromethyl groups), and the like.

Examples of the ionic photoacid generator type photo-cationic polymerization initiator include aromatic sulfonium salts, aromatic iodonium salts, aromatic diazonium salts, aromatic ammonium salts, and (2, 4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -Fe salts having the above-mentioned anionic moiety.

Examples of the aromatic sulfonium salt include bis (4- (diphenylsulfonium) phenyl) sulfide bishexafluoro phosphate, bis (4- (diphenylsulfonium) phenyl) sulfide bishexafluoroantimonate, bis (4- (diphenylsulfonium) phenyl) sulfide bistetrafluoroborate, bis (4- (diphenylsulfonium) phenyl) sulfide tetrakis (pentafluorophenyl) borate, diphenyl-4- (phenylthio) phenylsulfonium hexafluorophosphate, diphenyl-4- (phenylthio) phenylsulfonium hexafluoroantimonate, diphenyl-4- (phenylthio) phenylsulfonium tetrafluoroborate, diphenyl-4- (phenylthio) phenylsulfonium tetrakis (pentafluorophenyl) borate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, and the like, Bis (4- (2-hydroxyethoxy)) phenylsulfone) phenyl) sulfide bishexafluorophosphate, bis (4- (2-hydroxyethoxy)) phenylsulfone) phenyl) sulfide bishexafluoroantimonate, bis (4- (2-hydroxyethoxy)) phenylsulfone) phenyl) sulfide bistetrafluoroborate, bis (4- (2-hydroxyethoxy)) phenylsulfone) phenyl) sulfide tetrakis (pentafluorophenyl) borate, tris (4- (4-acetylphenyl) thiophenyl) sulfonium tetrakis (pentafluorophenyl) borate, and the like.

Examples of the aromatic iodonium salts include diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium tetrakis (pentafluorophenyl) borate, bis (dodecylphenyl) iodonium hexafluorophosphate, bis (dodecylphenyl) iodonium hexafluoroantimonate, bis (dodecylphenyl) iodonium tetrafluoroborate, bis (dodecylphenyl) iodonium tetrakis (pentafluorophenyl) borate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium hexafluorophosphate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium hexafluoroantimonate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrafluoroborate, 4-methylphenyl-4- (1-methylethyl) phenyliodonium tetrakis (pentafluorophenyl) borate, etc.

Examples of the aromatic diazonium salt include phenyldiazonium hexafluorophosphate, phenyldiazonium hexafluoroantimonate, phenyldiazonium tetrafluoroborate, and phenyldiazonium tetrakis (pentafluorophenyl) borate.

Examples of the aromatic ammonium salt include 1-benzyl-2-cyanopyridinium hexafluorophosphate, 1-benzyl-2-cyanopyridinium hexafluoroantimonate, 1-benzyl-2-cyanopyridinium tetrafluoroborate, 1-benzyl-2-cyanopyridinium tetrakis (pentafluorophenyl) borate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluorophosphate, 1- (naphthylmethyl) -2-cyanopyridinium hexafluoroantimonate, 1- (naphthylmethyl) -2-cyanopyridinium tetrafluoroborate, and 1- (naphthylmethyl) -2-cyanopyridinium tetrakis (pentafluorophenyl) borate.

Examples of the (2, 4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -Fe salt include (2, 4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -Fe (ii) hexafluorophosphate, (2, 4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -Fe (ii) hexafluoroantimonate, (2, 4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -Fe (ii) tetrafluoroborate, and (2, 4-cyclopentadien-1-yl) ((1-methylethyl) benzene) -Fe (ii) tetrakis (pentafluorophenyl) borate.

Examples of the nonionic photoacid-generating type photocationic polymerization initiator include nitrobenzyl esters, sulfonic acid derivatives, phosphate esters, phenol sulfonic acid esters, diazonaphthoquinones, and N-hydroxyimide sulfonic acid salts.

Examples of commercially available products among the above-mentioned photo cation polymerization initiators include DTS-200 (manufactured by Green chemical Co., Ltd.); UVI6990 and UVI6974 (both manufactured by Union Carbide Co., Ltd.); SP-150 and SP-170 (both manufactured by ADEKA Co., Ltd.); FC-508, FC-512 (both 3M); IRGACURE261, IRGACURE290 (both manufactured by BASF corporation); PI2074 (Rhodia).

The thermal cationic polymerization initiator may be a compound having an anionic moiety derived from BF₄ ^-、PF₆ ^-、SbF₆ ^-Or (BX)₄)^-(wherein X represents a phenyl group substituted with at least 2 or more fluorine groups or trifluoromethyl groups), sulfonium salts, phosphonium salts, ammonium salts, and the like. Among them, sulfonium salts and ammonium salts are preferable.

Examples of the sulfonium salt include triphenylsulfonium tetrafluoroborate and triphenylsulfonium hexafluoroantimonate.

Examples of the phosphonium salt include ethyltriphenylphosphonium hexafluoroantimonate and tetrabutylphosphonium hexafluoroantimonate.

Examples of the above ammonium salts include dimethylphenyl (4-methoxybenzyl) ammonium hexafluorophosphate, dimethylphenyl (4-methoxybenzyl) ammonium hexafluoroantimonate, dimethylphenyl (4-methoxybenzyl) ammonium tetrakis (pentafluorophenyl) borate, dimethylphenyl (4-methylbenzyl) ammonium hexafluorophosphate, dimethylphenyl (4-methylbenzyl) ammonium hexafluoroantimonate, dimethylphenyl (4-methylbenzyl) ammonium hexafluorotetrakis (pentafluorophenyl) borate, methylphenyldibenzylammonium hexafluorophosphate, methylphenyldibenzylammonium hexafluoroantimonate, methylphenyldibenzylammonium tetrakis (pentafluorophenyl) borate, phenyltribenzylammonium tetrakis (pentafluorophenyl) borate, dimethylphenyl (3, 4-dimethylbenzyl) ammonium tetrakis (pentafluorophenyl) borate, N-dimethyl-N-benzylanilinium hexafluoroantimonate, N-dimethyl-N-benzylammonium hexafluoroantimonate, N-methyl-phenyl-4-methylbenzyl-ammonium hexafluoroantimonate, N-salt, N-methyl-benzyl-ammonium salt, N-phenyl-ammonium salt, N-benzylammonium hexafluoroantimonate, N-phenyl salt, N-phenyl-N-benzylammonium salt, N-benzylammonium salt, N-bis (p-phenyl-phosphonium salt, N-benzylammonium salt, N-bis (p-phenyl-phosphonium salt, N-phenyl-phosphonium salt, N-bis (p-phenyl-bis (p-phenyl-phosphonium salt, e, b-phenyl-phosphonium salt, b-phenyl-phosphonium salt, e, and-phenyl-bis (p-phenyl-phosphonium salt, e, and-phenyl-bis (p-phenyl-phosphonium salt, e, and-phenyl-phosphonium salt, and-bis (p-phenyl-phosphonium salt, borate, and-phenyl-ammonium salt, e, b-bis (p-phenyl-bis-phenyl-, N, N-diethyl-N-benzylanilinium tetrafluoroborate, N-dimethyl-N-benzylpyridinium hexafluoroantimonate, N-diethyl-N-benzylpyridinium trifluoromethanesulfonate and the like.

As the above thermal cationic polymerization initiator, commercially available ones such as San-Aid SI-60, San-Aid SI-80, San-Aid SI-B3, San-Aid SI-B3A and San-Aid SI-B4 (all manufactured by Sanxin chemical industries, Ltd.); CXC1612 and CXC1821 (both King Industries, Ltd.), and the like.

The lower limit of the content of the polymerization initiator is preferably 0.01 part by weight, and the upper limit is preferably 10 parts by weight, based on 100 parts by weight of the polymerizable compound. By setting the content of the polymerization initiator to 0.01 parts by weight or more, the curability of the obtained sealant for an organic EL display element becomes more excellent. By setting the content of the polymerization initiator to 10 parts by weight or less, the curing reaction of the obtained sealant for an organic EL display element is not excessively accelerated, the workability is more excellent, and the cured product can be more uniform. The lower limit of the content of the polymerization initiator is more preferably 0.05 part by weight, and the upper limit is more preferably 5 parts by weight.

The sealing agent for an organic EL display element of the present invention may contain a sensitizer. The sensitizer has an effect of further improving the polymerization initiation efficiency of the polymerization initiator and further promoting the curing reaction of the sealant for an organic EL display element of the present invention.

Examples of the sensitizer include thioxanthone compounds such as 2, 4-diethylthioxanthone; 2, 2-dimethoxy-1, 2-diphenylethan-1-one, benzophenone, 2, 4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4 '-bis (dimethylamino) benzophenone, 4-benzoyl-4' -methyldiphenyl sulfide and the like.

The content of the sensitizer is preferably 0.01 part by weight or less, and more preferably 3 parts by weight or more, per 100 parts by weight of the polymerizable compound. The sensitizing agent is contained in an amount of 0.01 part by weight or more, whereby the sensitizing effect can be further exerted. By setting the content of the sensitizer to 3 parts by weight or less, light can be transmitted to a deep part without excessively increasing absorption. A more preferable lower limit of the content of the sensitizer is 0.1 part by weight, and a more preferable upper limit is 1 part by weight.

The sealing agent for an organic EL display element of the present invention may contain a silane coupling agent. The silane coupling agent has an effect of improving the adhesion of the sealant for an organic EL display element of the present invention to a substrate or the like.

Examples of the silane coupling agent include 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane and 3-isocyanatopropyltrimethoxysilane. These silane coupling agents may be used alone, or two or more of them may be used in combination.

The preferable lower limit of the content of the silane coupling agent is 0.1 part by weight and the preferable upper limit is 10 parts by weight with respect to 100 parts by weight of the polymerizable compound. When the content of the silane coupling agent is in this range, the effect of improving the adhesion can be further enhanced while suppressing bleeding of the excess silane coupling agent. The lower limit of the content of the silane coupling agent is more preferably 0.5 part by weight, and the upper limit is more preferably 5 parts by weight.

The sealing agent for an organic EL display element of the present invention may further contain a surface modifier within a range not to impair the object of the present invention. By containing the surface modifier, the flatness of the coating film can be imparted to the sealant for an organic EL display element of the present invention.

Examples of the surface modifier include a surfactant and a leveling agent.

Examples of the surface modifier include silicone-based surface modifiers and fluorine-based surface modifiers.

Examples of commercially available products among the above surface modifiers include BYK-340, BYK-345 (both BYK-Chemie JAPAN Co.), Surflon S-611(AGC Seimi Chemical Co., Ltd.).

The sealant for an organic EL display element of the present invention may contain a solvent for the purpose of adjusting viscosity or the like, but there is a concern that problems such as deterioration of the organic light emitting material layer or degassing may occur due to the remaining solvent, and therefore, it is preferable that no solvent is contained or the content of the solvent is 0.05 wt% or less.

The sealing agent for an organic EL display element of the present invention may contain various known additives such as a reinforcing agent, a softening agent, a plasticizer, a viscosity modifier, an ultraviolet absorber, and an antioxidant, as needed.

Examples of the method for producing the sealing agent for an organic EL display element of the present invention include a method of mixing a polymerizable compound, a polymerization initiator, and, if necessary, an additive such as a silane coupling agent, using a mixer such as a homomixer, a universal mixer, a planetary mixer, a kneader, or a three-roll mill.

The lower limit of the total light transmittance of the cured product of the sealing agent for an organic EL display element of the present invention at a wavelength of 380 to 800nm is preferably 80%. By setting the total light transmittance to 80% or more, the optical characteristics of the obtained organic EL display device become more excellent. A more preferred lower limit of the total light transmittance is 85%.

The total light transmittance can be measured using a spectrometer such as an AUTOMATIC HAZE matrix MODEL TC ═ III DPK (manufactured by tokyo electric color corporation).

Further, if the cured product used for the measurement of the total light transmittance is a photocurable sealing agent, the sealing agent can be irradiated with, for example, 3000mJ/cm by an LED lamp²365nm, or a thermosetting sealing agent, for example, by heating at 80 ℃ for 1 hour.

The sealant for an organic EL display element of the present invention preferably has a transmittance at 400nm of 85% or more in terms of an optical path length of 20 μm after irradiating a cured product with ultraviolet light for 100 hours. When the transmittance after 100 hours of ultraviolet irradiation is 85% or more, the transparency is increased, the loss of light emission is reduced, and the color reproducibility is further improved. The lower limit of the transmittance after 100 hours of the ultraviolet irradiation is more preferably 90%, and still more preferably 95%.

As the light source for irradiating the ultraviolet ray, a conventionally known light source such as a xenon lamp or a carbon arc lamp can be used.

Further, if the cured product used for the measurement of the transmittance after the irradiation with ultraviolet light for 100 hours is a photocurable sealant, the sealant can be irradiated with, for example, an LED lamp at 3000mJ/cm²365nm, or a thermosetting sealing agent, for example, by heating at 80 ℃ for 1 hour.

The sealant for an organic EL display element of the present invention is a 100 μm thick strip obtained by exposing a cured product to an atmosphere of 85 ℃ and 85% RH for 24 hours in accordance with JIS Z0208The moisture permeability under the member is preferably 100g/m²The following. By setting the above moisture permeability to 100g/m²As a result, the effect of preventing the occurrence of dark spots due to the moisture reaching the organic light-emitting material layer becomes more excellent, and the reliability of the resulting organic EL display element becomes more excellent.

Further, if the cured product used for the measurement of the moisture permeability is a photocurable sealing agent, the sealing agent can be irradiated with, for example, 3000mJ/cm by an LED lamp²365nm, or a thermosetting sealing agent, for example, by heating at 80 ℃ for 1 hour.

Further, in the sealant for an organic EL display element of the present invention, when the cured product is exposed to an environment of 85 ℃ and 85% RH for 24 hours, the water content of the cured product is preferably less than 0.5%. By setting the water content of the cured product to less than 0.5%, the effect of preventing the organic light-emitting material layer from being deteriorated by the water content in the cured product becomes more excellent, and the reliability of the obtained organic EL display element becomes more excellent. The upper limit of the water content of the cured product is more preferably 0.3%.

Examples of the method for measuring the water content include a method of obtaining the water content by the karl fischer method according to JIS K7251, and a method of obtaining the weight gain after water absorption according to JIS K7209-2.

Further, if the cured product used for the measurement of the water content is a photocurable sealing agent, the sealing agent can be irradiated with, for example, 3000mJ/cm using an LED lamp²And 365nm, and a thermosetting sealing agent, for example, by heating at 80 ℃ for 1 hour.

The sealant for an organic EL display element of the present invention 1 can be suitably used for coating by an ink jet method, and the sealant for an organic EL display element of the present invention 2 can be used for coating by an ink jet method.

Examples of the method for producing an organic EL display element using the sealant for an organic EL display element of the present invention include a method including the following steps: a step of applying the sealant for an organic EL display element of the present invention to a substrate by an inkjet method; and curing the applied sealing agent for the organic EL display element by light irradiation and/or heating.

In the step of applying the sealant for an organic EL display element of the present invention to a substrate, the sealant for an organic EL display element of the present invention may be applied to the entire surface of the substrate or may be applied to a part of the substrate. The shape of the sealing portion of the sealing agent for an organic EL display element of the present invention formed by coating is not particularly limited as long as it is a shape capable of protecting a laminate having an organic light emitting material layer from an external gas, and may be a shape that completely covers the laminate, may be a pattern that is closed at the peripheral portion of the laminate, or may be a pattern that is a shape in which a part of an opening is provided at the peripheral portion of the laminate.

When the sealing agent for an organic EL display element is cured by light irradiation, the sealing agent for an organic EL display element of the present invention can be cured by light irradiation with a wavelength of 300 to 400nm and a cumulative light amount of 300 to 3000mJ/cm²Is well cured.

Examples of the light source for irradiating the sealing agent for an organic EL display element of the present invention with light include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, an excimer laser, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, a metal halide lamp, a sodium lamp, a halogen lamp, a xenon lamp, an LED lamp, a fluorescent lamp, sunlight, and an electron beam irradiation device. These light sources may be used alone, or two or more kinds may be used in combination.

These light sources can be appropriately selected according to the absorption wavelength of the photo-radical polymerization initiator or photo-cation polymerization initiator.

Examples of the means for irradiating the sealing agent for an organic EL display element of the present invention with light include simultaneous irradiation with various light sources, sequential irradiation with time difference, and combined irradiation of simultaneous irradiation and sequential irradiation, and any irradiation means can be used.

The cured product obtained by the step of curing the sealing agent for an organic EL display element by light irradiation and/or heating may be further covered with an inorganic material film.

As the inorganic material constituting the inorganic material film, conventionally known inorganic materials can be used, and examples thereof include silicon nitride (SiN)_x) Silicon oxide (SiO)_x) And the like. The inorganic material film may be composed of 1 layer, or a plurality of layers may be laminated. The laminate may be covered with the inorganic material film and the resin film containing the sealant for an organic EL display element of the present invention alternately and repeatedly.

The method of manufacturing the organic EL display device may include the steps of: a step of bonding the substrate coated with the sealant for an organic EL display element of the present invention (hereinafter, also referred to as "one substrate") to the other substrate.

The substrate (hereinafter, also referred to as "one substrate") to which the sealant for an organic EL display element of the present invention is applied may be a substrate on which a laminate having an organic light-emitting material layer is formed, or may be a substrate on which the laminate is not formed.

When the one substrate is a substrate on which the laminate is not formed, the sealant for an organic EL display element of the present invention may be applied to the one substrate so that the laminate can be protected from external air when the other substrate is bonded. That is, the entire surface of the portion to be the position of the laminate may be coated when the other substrate is bonded, or the sealant portion may be formed in a pattern that closes the shape in which the portion to be the position of the laminate is completely housed when the other substrate is bonded.

The step of curing the sealant for organic EL display elements by light irradiation and/or heating may be performed before the step of bonding the one substrate to the other substrate, or may be performed after the step of bonding the one substrate to the other substrate.

In the case where the step of curing the sealant for organic EL display elements by light irradiation and/or heating is performed before the step of bonding the one substrate and the other substrate, the pot life of the sealant for organic EL display elements of the present invention is preferably 1 minute or more from the time of light irradiation and/or heating until the curing reaction proceeds and bonding is not possible. By setting the usable time to 1 minute or more, curing does not progress excessively before the one base material and the other base material are bonded, and a higher adhesive strength can be obtained.

In the step of bonding the one substrate and the other substrate, a method of bonding the one substrate and the other substrate is not particularly limited, and bonding is preferably performed in a reduced pressure atmosphere.

The lower limit of the degree of vacuum in the reduced pressure atmosphere is preferably 0.01kPa, and the upper limit is preferably 10 kPa. By setting the degree of vacuum in the reduced-pressure atmosphere to this range, it takes no longer time to reach a vacuum state from the viewpoint of airtightness of a vacuum apparatus and the capability of a vacuum pump, and bubbles in the sealant for an organic EL display element of the present invention when the one substrate and the other substrate are bonded can be removed more effectively.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention can provide a sealing agent for an organic EL display element, which can be easily applied by an ink jet method, has excellent low outgassing properties, and can provide a cured product having excellent bending resistance.

Detailed Description

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 5 and comparative examples 1 to 4

The respective materials were uniformly stirred and mixed at a stirring speed of 3000rpm using a homodispersion type stirring mixer (manufactured by Primix, "homo plastic L type") in accordance with the mixing ratios shown in table 1, thereby producing respective sealants for organic EL display elements of examples 1 to 5 and comparative examples 1 to 4.

The viscosities measured at 25 ℃ and 100rpm using an E-type VISCOMETER (manufactured by eastern industries, Ltd. "VISCOMETER TV-22") and the surface tensions measured at 25 ℃ by a dynamic wettability tester (manufactured by RHESCA, manufactured by "WET-6100") for the respective sealants for organic EL display elements obtained in examples and comparative examples are shown in table 1.

Further, the sealants for the organic EL display elements obtained in examples and comparative examples were each applied at 3000mJ/cm using an LED lamp²The film was produced by irradiating ultraviolet rays having a wavelength of 365 nm. The obtained film (thickness: 1mm) was subjected to a tensile test at a constant speed using a tensile tester (model 5582, manufactured by INSTRON) and an orthogonal strain gauge (KFG-5-120-D16-23, manufactured by Union electric industries), under conditions of 25 ℃, 50% RH and an inter-jig distance of 100mm, to determine a Poisson's ratio and a Young's modulus. The measurement results of poisson's ratio and young's modulus are shown in table 1.

< evaluation >

The following evaluations were made with respect to the sealants for organic EL display elements obtained in examples and comparative examples. The results are shown in Table 1.

In each of the evaluations of the ink ejection property, the wetting and diffusing property, and the reliability of the organic EL display element, IJH-30 (manufactured by IJT) was used as an ink jet coating head, and ink jet coating was performed without heating (the head temperature was 25 ℃).

(1) Ink-jet coatability

(1-1) ink jet ejectability

The respective organic EL display element sealants obtained in examples and comparative examples were applied to alkali-free glass (asahi glass, "AN 100") cleaned with alkali, using AN inkjet discharge apparatus (manufactured by microdot, "NanoPrinter 500"), at a drop volume of 30 picoliters. The ink ejection performance was evaluated by marking "o" for the case where the liquid droplets were normally ejected from the ink ejection nozzles and landed on the substrate and "x" for the case where the liquid droplets were not normally ejected.

(1-2) wetting diffusion Property

The respective organic EL display element sealants obtained in examples 1 to 5 and comparative examples 3 and 4 were applied to alkali-cleaned alkali-free glass (manufactured by asahi glass, "AN 100") at a rate of 5 m/sec and at a pitch of 500 μm in a drop amount of 30 picoliters using AN ink jet apparatus (manufactured by microsoft corporation, "NanoPrinter 500"). The diameter of the droplet on the alkali-free glass 10 minutes after the application was measured, and the diameter of the droplet was designated as "O" when the droplet was 150 μm or more, as "Δ" when the droplet was 50 μm or more and less than 150 μm, and as "X" when the droplet was less than 50 μm, and the wetting and diffusing properties were evaluated.

(2) Low degassing property

The outgas generated during heating of the cured products of the sealants for organic EL display elements obtained in examples 1 to 5 and comparative examples 3 and 4 was measured by a gas chromatograph (manufactured by JEOL, "JMS-Q1050 GC") based on the headspace method. Each organic EL display element was coated with 100mg of the sealant to a thickness of 300 μm by an applicator. Next, 3000mJ/cm was irradiated with an LED lamp²Curing the sealant with 365nm ultraviolet rays, filling the cured sealant into a vial for headspace, sealing the vial, heating at 100 ℃ for 30 minutes, and measuring the generated gas by headspace method.

The gas generated was evaluated for low outgassing, and the gas was evaluated for less than 300ppm as "O", 300ppm or more and less than 500ppm as "Δ", and 500ppm or more as "X".

(3) Bending resistance (mandrel test)

The cured products of the sealants for organic EL display elements obtained in examples 1 to 5 and comparative examples 3 and 4 were measured for bending resistance by a cylindrical mandrel test having a predetermined radius of curvature in the following manner.

First, a sealant for each organic EL display element was dropped on a polyethylene naphthalate substrate having a thickness of 100 μm, applied to a thickness of 10 μm by a spin coater, and then applied at 3000mJ/cm by an LED lamp²The test piece was obtained by irradiating ultraviolet rays having a wavelength of 365 nm.

Next, the cylindrical mandrel test was carried out on the test piece obtained in accordance with JIS K5600-5-1. In the mandrel test, a cylindrical mandrel having a diameter of 10mm and a diameter of 4mm was used, and the test was performed in the order of a mandrel having a smaller diameter from a mandrel having a larger diameter, and the diameter of the mandrel having a test piece first cracked or peeled off was confirmed. The bending resistance was evaluated by marking "o" for the case where no crack or peeling occurred even in the case of the mandrel having a diameter of 4mm, marking "Δ" for the case where no crack or peeling occurred in the case of the mandrel having a diameter of 10mm but crack or peeling occurred in the case of the mandrel having a diameter of 4mm, and marking "x" for the case where crack or peeling occurred in the case of the mandrel having a diameter of 10 mm.

(4) Reliability of organic EL display element

(4-1) production of substrate having laminate comprising organic light-emitting Material layer

Is coated on a glass substrate (25 mm in length, 25mm in width and 0.7mm in thickness)The thickness of (3) is such that an ITO electrode is formed into a film, and the film is used as a substrate. The substrate was ultrasonically cleaned with acetone, an aqueous alkali solution, ion-exchanged water, and isopropyl alcohol for 15 minutes, then cleaned with boiling isopropyl alcohol for 10 minutes, and further pretreated with a UV-ozone cleaner (NL-UV 253, manufactured by japan laser electronics).

Next, the substrate was fixed to a substrate holder of a vacuum deposition apparatus, 200mg of N, N '-bis (1-naphthyl) -N, N' -diphenylbenzidine (. alpha. -NPD) was charged into a bisque-fired crucible, and tris (8-quinolinolato) aluminum (Alq) was charged into another bisque-fired crucible₃)200mg, the pressure in the vacuum chamber was reduced to 1X 10^-4Pa is up to. Thereafter, the crucible containing the alpha-NPD is heated to cause the alpha-NPD to react with the molten metalIs deposited on a substrate at a deposition rate to form a film with a thickness ofThe hole transport layer of (1). Then, will be charged with Alq₃Is heated in a crucible toThe deposition rate of (2) is set to a film thicknessThe organic light emitting material layer of (1). Thereafter, the substrate on which the hole transport layer and the organic light-emitting material layer were formed was transferred to another vacuum deposition apparatus, and 200mg of lithium fluoride was charged into a tungsten resistance heating boat in the vacuum deposition apparatus, and 1.0g of an aluminum wire was charged into another tungsten boat. Thereafter, the pressure in the evaporator of the vacuum evaporation apparatus was reduced to 2 × 10^-4Pa, and fluorinating lithium withIs deposited at a deposition rate ofThen, aluminum is addedAt a rate of film formation ofThe inside of the evaporator was returned to normal pressure by nitrogen gas, and the substrate on which the laminate having 10mm × 10mm organic light-emitting material layers was disposed was taken out.

(4-2) covering based on inorganic Material film A

A mask having an opening of 13mm × 13mm was provided so as to cover the entire laminate in the resulting substrate on which the laminate was disposed, and the inorganic material film a was formed by a plasma CVD method.

The plasma CVD method was performed under the following conditions: SiH is used as the raw material gas₄Gas and nitrogen gas, the respective flow rates being SiH₄The gas was 10sccm, the nitrogen gas was 200sccm, the RF power was 10W (frequency: 2.45GHz), the temperature in the chamber was 100 ℃, and the pressure in the chamber was 0.9 Torr.

The thickness of the inorganic material film a formed was about 1 μm.

(4-3) formation of resin protective film

The obtained substrate was pattern-coated with each of the organic EL display element sealants obtained in examples 1 to 5 and comparative examples 3 and 4 using an inkjet discharge apparatus ("NanoPrinter 500", manufactured by microdot corporation).

Thereafter, using an LED lamp, 3000mJ/cm was irradiated²And 365nm, curing the sealant for the organic EL display element to form a resin protective film.

(4-4) covering based on inorganic Material film B

After the resin protective film was formed, a mask having an opening of 12mm × 12mm was provided so as to cover the entire resin protective film, and the inorganic material film B was formed by a plasma CVD method, thereby obtaining an organic EL display element.

The plasma CVD method is performed under the same conditions as the above-mentioned "(4-2) covering with the inorganic material film a".

The thickness of the inorganic material film B formed was about 1 μm.

(4-5) light-emitting State of organic EL display element

The organic EL display device thus obtained was exposed to an environment of 85 ℃ and 85% humidity for 100 hours, and then a voltage of 3V was applied to visually observe the light emission state (presence or absence of black dots and extinction around pixels) of the organic EL display device. The reliability of the organic EL display element was evaluated by marking "o" for the case where no black dot was present and no peripheral extinction occurred and uniform light emission was observed, marking "Δ" for the case where no black dot was present and no peripheral extinction was present but slight decrease in luminance was observed, and marking "x" for the case where no black dot was present and no peripheral extinction was observed.

[ Table 1]

In order to confirm the effect of the viscosity of the organic EL display element sealant on the ink-jet coatability in the non-heating type ink-jet method and the heating type ink-jet method, the following experiment was performed. The results are shown in Table 2.

(Experimental example 1)

The respective materials were uniformly stirred and mixed at a stirring speed of 3000rpm using a homodispersion type stirring mixer (manufactured by Primix, "homo plastic L type") in accordance with the mixing ratio described in table 2, and then subjected to a dehydration step of exposing the mixture to an environment of 50 ℃ and 0.1MPa for 30 minutes, thereby producing a sealant for an organic EL display element.

The obtained sealing agent for organic EL display element was measured for viscosity at 25 ℃ and 100rpm using an E-type VISCOMETER (manufactured by eastern industries, Ltd. "VISCOMETER TV-22") and for surface tension at 25 ℃ using a dynamic wettability tester (manufactured by RHESCA, manufactured by "WET-6100").

The obtained sealant for organic EL display element was applied to an LED lamp at 3000mJ/cm²The film was produced by irradiating ultraviolet rays having a wavelength of 365 nm. The obtained film (thickness: 1mm) was subjected to a tensile test at a constant speed using a tensile tester (model 5582, manufactured by INSTRON) and an orthogonal strain gauge (KFG-5-120-D16-23, manufactured by Union electric industries), under conditions of 25 ℃, 50% RH and an inter-jig distance of 100mm, to determine a Poisson's ratio and a Young's modulus.

The obtained organic EL display element sealant was applied to alkali-free glass (manufactured by asahi glass, "AN 100") which had been alkali-washed, in a drop amount of 30 picoliters using AN ink jet apparatus (manufactured by microsoft corporation, "NanoPrinter 500"). The case where the liquid droplets were normally ejected from the ink jet nozzles and landed on the substrate was marked as "o", and the case where the liquid droplets were not normally ejected was marked as "x", and the ink ejection performance was evaluated. The IJH-30 (manufactured by IJT) was used as an inkjet application head, and inkjet application was performed without heating (the head temperature was 25 ℃).

(Experimental example 2)

The same sealant for organic EL display elements as the sealant produced in experimental example 1 was prepared.

Ink jet ejection properties were evaluated in the same manner as in experimental example 1, except that IJH-30 (manufactured by IJT) was used as an ink jet coating head, and ink jet coating was performed while heating (head temperature 60 ℃).

[ Table 2]

Industrial applicability

The present invention provides a sealing agent for an organic EL display element, which can be easily applied by an ink jet method, has excellent low outgassing properties, and can provide a cured product having excellent bending resistance.