Composition for sealing organic light-emitting device and organic light-emitting display device including the same

Abstract

The present invention relates to a composition for sealing an organic light-emitting element, and an organic light-emitting display device including the same, and more particularly to a composition for sealing an organic light-emitting element that can effectively block moisture or oxygen from entering the organic light-emitting display device from the outside, thereby ensuring the performance and lifespan of the organic light-emitting element and having low dielectric constant characteristics such that touch sensitivity is improved, and an organic light-emitting display device including the same.

Description

[Technical Field]

[0001] The present invention relates to a composition for sealing an organic light-emitting element, and an organic light-emitting display device including the same. The composition not only ensures the performance and lifespan of an organic light-emitting element by effectively blocking moisture or oxygen from entering the organic light-emitting display device from the outside, but also has low dielectric constant characteristics to improve the touch sensitivity of a touch panel, and an organic light-emitting display device including the same. [Background technology]

[0002] The organic layer materials, electrodes, etc. that constitute organic light-emitting devices have a problem in that their light-emitting characteristics and lifespan are deteriorated by external moisture and oxygen. Therefore, a protective layer that can protect the organic materials, electrodes, etc. is required. Such a protective layer is usually formed with a structure in which one or more organic and inorganic layers are stacked to effectively block external moisture and oxygen.

[0003] Recently, capacitive touch panels using organic light-emitting devices have been widely adopted. Capacitive touch panels detect touch by detecting a change in capacitance when a conductor comes into contact with the touch panel. Materials with high dielectric constants tend to exhibit significant polarization when an external electric field is applied, resulting in reduced touch sensitivity. Therefore, there is a need for the development of a sealing composition for organic layers used in a laminate structure that has low dielectric constant characteristics and provides excellent touch sensitivity for touch panels. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide a composition for encapsulating an organic light-emitting device that can effectively block moisture or oxygen from entering an organic light-emitting display device from the outside, thereby ensuring the performance and lifespan of the organic light-emitting device and also having low dielectric constant characteristics to provide excellent touch sensitivity of a touch panel, and an organic light-emitting display device including the same. [Means for solving the problem]

[0005] The present invention provides a composition for sealing an organic light-emitting element, which has been devised to solve the above problems, and is characterized by comprising a photocurable monomer including all of the monomers represented by the following chemical formulas 1 to 3, and a photopolymerization initiator, and the composition may have a dielectric constant of 2.65 or less at a frequency in the range of 100 KHz to 1 MHz, and a ring parameter of 0.01 to 0.25.

[0006] [ka]

[0007] [ka]

[0008] [ka]

[0009] In the above Chemical Formula 1 to Chemical Formula 3, R1 to R5 are each independently a (meth)acryloyl group, L1 and L2 are each independently a substituted or unsubstituted C 1-10 X1 and X2 are each independently hydrogen or C 1-10 and m and n are each an integer of 1 to 4.

[0010] Another organic light-emitting display device of the present invention is characterized by including a sealing part containing the organic light-emitting element sealing composition. [Effects of the Invention]

[0011] When the encapsulating composition for organic light emitting device according to the present invention is used to form an encapsulation part of an organic light emitting display device, it can effectively block moisture or oxygen from entering from the outside, thereby ensuring the performance and lifespan of the organic light emitting device. In addition, it has a low dielectric constant characteristic, which results in an excellent touch feeling of the touch panel. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating an organic light emitting display device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0014] When assigning reference numerals to components in each drawing, it should be noted that the same reference numerals are assigned whenever possible even when the same components are displayed in different drawings. Furthermore, in describing the present invention, if a detailed description of related known structures or functions is deemed to obscure the gist of the present invention, the detailed description thereof will be omitted.

[0015] When a component is described as being "coupled," "bonded," or "connected" to another component, the component can be directly coupled or connected to the other component, but other components can also be "coupled," "bonded," or "connected" between the components. Furthermore, when a component such as a layer, film, region, or plate is described as being "on" or "on top of" another component, this includes not only the case where it is "directly on" the other component, but also the case where there are other components between them. Conversely, when a component is described as being "directly on" another part, it means that there are no other parts between them.

[0016] As used herein, the term "(meth)acrylic" means acryl and / or methacryl.

[0017] The term "alkyl group," as used herein, unless otherwise specified, means the radical of a saturated aliphatic functional group having from 1 to 60 carbons linked by a single bond, including straight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl-substituted cycloalkyl groups, and cycloalkyl-substituted alkyl groups.

[0018] The term "alkylene group" as used herein means saturated hydrocarbon-linked alkanediyl groups without double bonds, meaning that they have two linking groups.

[0019] Unless otherwise specified, the term "substituted or unsubstituted" used herein means any group selected from the group consisting of deuterium, halogen, amino group, nitrile group, nitro group, C 1-20 Alkyl groups of C 1-20 Alkoxy groups, C 1-20 alkylamine group, C 1-20 alkylthiophene group, C 6-20 arylthiophene group, C 2-20 Alkenyl groups of C 2-20 Alkynyl groups, C 3-20 cycloalkyl groups, C 6-20 aryl groups, deuterium-substituted C 6-20 aryl groups, C 8-20 C containing an arylalkenyl group, a silane group, a boron group, and at least one heteroatom selected from the group consisting of O, N, S, Si, and P 2-20 This means that the heterocyclic group may be substituted with one or more substituents selected from the group consisting of the following heterocyclic groups, but is not necessarily limited to these substituents.

[0020] The term "dielectric constant" used herein means a value measured by a capacitance method for an organic layer including the composition for sealing an organic light-emitting device according to the present invention.

[0021] The term "viscosity" used herein means a value measured using a rotational viscometer for an organic layer including the composition for sealing an organic light emitting device according to the present invention.

[0022] The composition for sealing an organic light emitting device according to the present invention includes a photocurable monomer including all of the monomers represented by the following Chemical Formulas 1 to 3, and a photopolymerization initiator.

[0023] In addition, the composition for sealing an organic light emitting device according to the present invention may have a dielectric constant of 2.65 or less at a frequency of 100 KHz to 1 MHz, a ring parameter of 0.01 to 0.25, and a viscosity of 10 to 20 cPs. For reference, the ring parameter refers to a value obtained by dividing the molecular weight of carbon contained in a cyclo or phenyl ring by the total molecular weight, and can be defined by the following mathematical formula 1.

[0024]

number

[0025] [ka]

[0026] [ka]

[0027] [ka]

[0028] In the above Chemical Formula 1 to Chemical Formula 3, R1 to R5 are each independently a (meth)acryloyl group, L1 and L2 are each independently a substituted or unsubstituted C 1-10 X1 and X2 are each independently hydrogen or C 1-10 and m and n are each an integer of 1 to 4.

[0029] The monomer represented by Chemical Formula 1 may be one or more selected from the group consisting of 1,14-tetradecanediol di(meth)acrylate, 1,15-pentadecanediol di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, 1,17-heptadecanediol di(meth)acrylate, and 1,18-octadecanediol di(meth)acrylate, but is not necessarily limited thereto.

[0030] In addition, the monomer represented by Chemical Formula 2 may be one or more selected from the group consisting of isotetradecyl (meth)acrylate, isopentadecyl (meth)acrylate, isohexadecyl (meth)acrylate, isoheptadecyl (meth)acrylate, and isooctadecyl (meth)acrylate, but is not necessarily limited thereto.

[0031] The monomer represented by Chemical Formula 3 may be at least one selected from the group consisting of bisphenol A ethylene oxide diacrylate, bisphenol A ethylene oxide dimethacrylate, bisphenol A ethoxylate diacrylate, bisphenol A ethoxylate diacrylate, bisphenol A polyethoxylate diacrylate, and bisphenol A diacrylate, but is not necessarily limited thereto.

[0032] The photocurable monomer according to the present invention may further include at least one monomer selected from the group consisting of compounds represented by the following Formulas 4 to 6:

[0033] [ka]

[0034] [ka]

[0035] [ka]

[0036] In the above Chemical Formula 4 to Chemical Formula 6, R6 and R7 are each independently a (meth)acryloyl group, and A is a C group that forms two bridged rings. 1-12 and B is a substituted or unsubstituted cycloalkylene group of C6 -12and L is a direct bond or a C 1-10 Ar1 is an alkylene group of the formula C 6-60 is an aryl group of the formula

[0037] One of R8 and R9 is hydrogen and the other is a methyl group; p is an integer of 1 to 300.

[0038] The photocurable monomer represented by the above Chemical Formula 4 may be a compound represented by the following Chemical Formula 7, but is not necessarily limited thereto.

[0039] [ka]

[0040] The monomer represented by the above chemical formula 5 may be a monomer selected from the group consisting of the following chemical formulas A-1 to A-3, but is not necessarily limited thereto.

[0041] [ka]

[0042] The photocurable monomer represented by the above formula 6 may be ethylene propylene diene monomer (EPDM).

[0043] The photocurable monomer is preferably contained in an amount of 20 to 99 wt % based on the total weight of the photocurable monomer.

[0044] More specifically, based on the total weight of the composition, the monomer represented by Chemical Formula 1 may be contained in an amount of 15 to 35 wt %, the monomer represented by Chemical Formula 2 may be contained in an amount of 30 to 65 wt %, the monomer represented by Chemical Formula 3 may be contained in an amount of 1 to 30 wt %, and the monomers represented by Chemical Formulas 4 to 6 may be contained in an amount of 1 to 30 wt %, respectively.

[0045] The composition for encapsulating an organic light emitting device according to the present invention includes a photopolymerization initiator capable of curing the photocurable monomer by UV irradiation or the like. The photopolymerization initiator is not particularly limited as long as it is a common photopolymerization initiator capable of causing a photocuring reaction. For example, the photopolymerization initiator may include a triazine-based, acetophenone-based, benzophenone-based, thioxanthone-based, benzoin-based, phosphorus-based, oxime-based, or a mixture thereof.

[0046] Examples of the triazines include 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis(trichloromethyl)-s-triazine, 2-(3',4'-dimethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4'-methoxynaphthyl)-4,6-bis(trichloromethyl)-s-triazine, 2-(p-methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, and 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine. The compound may be 2-biphenyl-4,6-bis(trichloromethyl)-s-triazine, bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphth-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-trichloromethyl(piperonyl)-6-triazine, 2,4-(trichloromethyl(4'-methoxystyryl)-6-triazine, or a mixture thereof.

[0047] The acetophenone may be 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylpropiophenone, pt-butyltrichloroacetophenone, pt-butyldichloroacetophenone, 4-chloroacetophenone, 2,2'-dichloro-4-phenoxyacetophenone, 2-methyl-1-(4-(methylthio)phenyl)-2-morpholino-propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholino-phenyl)-butan-1-one, or a mixture thereof.

[0048] The benzophenone-based compound may be benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4,4'-bis(dimethylamino)benzophenone, 4,4'-dichlorobenzophenone, 3,3'-dimethyl-2-methoxybenzophenone, or a mixture thereof.

[0049] The thioxanthone may be thioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone, or a mixture thereof.

[0050] The benzoin-based solvent may be benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl dimethyl ketal, or a mixture thereof.

[0051] The phosphorus-based compound may be bisbenzoylphenylphosphine oxide, benzoyldiphenylphosphine oxide, or a mixture thereof.

[0052] The oxime may be 2-(o-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione and 1-(o-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoin)-9H-carbazol-3-yl]ethane, or a mixture thereof.

[0053] The photopolymerization initiator is preferably contained in an amount of 0.1 to 10 wt % based on the total weight of the composition. This is because, when the photopolymerization initiator is contained in this content range, photopolymerization can occur sufficiently upon exposure, and unreacted initiator remaining after photopolymerization can be prevented from generating outgassing or reducing reliability.

[0054] The composition for sealing an organic light emitting device according to the present invention may further include at least one additive selected from the group consisting of a surfactant, a curing accelerator, and an antioxidant. In particular, the surfactant is advantageous in inducing dispersion of the composition.

[0055] The composition for sealing an organic light emitting device according to the present invention has a low dielectric constant of 2.60 or less at a frequency ranging from 100 KHz to 1 MHz, and therefore, when the sealing composition is applied to a touch panel, it has an excellent effect on touch sensitivity.

[0056] Furthermore, the composition for sealing an organic light-emitting device according to the present invention preferably has a viscosity of 10 to 20 cPs, because the processability of the composition is improved within this viscosity range.

[0057] Another organic light-emitting display device of the present invention includes a sealing part containing the organic light-emitting element sealing composition.

[0058] FIG. 1 is a diagram illustrating an organic light emitting display device according to an embodiment of the present invention. The organic light emitting display device disclosed in FIG. 1 includes a substrate 110, an organic light emitting element 200 disposed on the substrate 110, and an encapsulating unit 300 disposed on the organic light emitting element 200. While the encapsulating unit 300 is disclosed as a multi-layer structure including a first encapsulating layer 310 and a second encapsulating layer 320, the present invention also includes a structure in which the encapsulating unit 300 has two or more layers. When the encapsulating unit 300 has two layers, it may include an inorganic barrier layer and an organic barrier layer. For example, if the first encapsulating layer 310 is an inorganic barrier layer, the second encapsulating layer 320 may be an organic barrier layer, but the stacking order is not limited thereto.

[0059] The encapsulating unit 300 may be formed of an organic barrier layer for sealing or encapsulating the organic light emitting display device, and the organic barrier layer may be formed by photocuring the composition for sealing the organic light emitting device according to the present invention.

[0060] The sealing composition (organic barrier layer material) may be applied by inkjet, vacuum deposition, spin coating, or slit coating, and an initiator may be used for photo-curing.

[0061] The present invention will be specifically described below with reference to examples relating to the composition for sealing an organic light-emitting device according to the present invention, but the present invention is not limited to the following examples. [Example]

[0062] 100 parts by weight of the photocurable monomer and 1 part by weight of the photoinitiator (TPO) shown in Table 1 below were mixed together to prepare compositions for sealing organic light emitting devices according to Examples 1 to 4.

[0063] The composition prepared above was then stirred for 12 hours and filtered through a PTFE filter with a pore size of 0.45 μm.

[0064] The filtered organic light-emitting device sealing composition was spin-coated to a thickness of 8.0 μm or more, and then irradiated with a UV exposure device at a dose of 1 J to form a sealing film. The dielectric constant and viscosity were measured by the following methods.

[0065] Dielectric constant: The organic light emitting device sealing composition is coated on the lower electrode to a thickness of 8.0 μm or more and cured. Then, the upper electrode Ag is deposited to a thickness of 1,000 Å. The dielectric constant of the fabricated sample was calculated after measurement using a Keysight E4980A.

[0066] Viscosity: The viscosity of the liquid composition for sealing an organic light-emitting element was measured using a rotational viscometer.

[0067] As a result, in Examples 1 to 4 according to the present invention, the dielectric constant of the sealing film formed using the composition for sealing an organic light emitting device was 2.60 F / m or less, which confirmed that the touch panel using the sealing film prepared according to the present invention can achieve better touch sensitivity.

[0068] [Table 1]

[0069] The above description is merely illustrative of the present invention, and various modifications may be made by a person skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed herein are for the purpose of explanation rather than limitation of the present invention, and the spirit and scope of the present invention should not be limited by such embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technologies within the scope equivalent thereto should be interpreted as being within the scope of the present invention. [Explanation of symbols]

[0070] 100: Substrate 200: Organic light-emitting device 300: Sealing part 310: First sealing portion 320: Second sealing portion

Claims

1. A composition for sealing an organic light-emitting device, comprising: a photocurable monomer including all of the monomers represented by the following chemical formulas 1 to 4; and a photopolymerization initiator. 【Chemistry 1】 【Chemistry 2】 【Transformation 3】 【Chemistry 4】 In the above Chemical Formulas 1 to 4, R １ From R ５ are each independently a (meth)acryloyl group, L １ and L ２ are each independently substituted or unsubstituted C １－１０ is an alkylene group of the formula X １ and X ２ are each independently hydrogen or C １－１０ is an alkyl group of the formula m and n are each an integer from 1 to 18; one of R 8 and R 9 is hydrogen and the other is a methyl group; p is an integer from 1 to 300.

2. The composition for sealing an organic light-emitting element according to claim 1 , wherein the composition for sealing an organic light-emitting element has a dielectric constant of 2.65 or less at a frequency in a range of 100 Khz to 1 MHz.

3. The composition for sealing an organic light-emitting element according to claim 1 , wherein the composition for sealing an organic light-emitting element has a ring parameter calculated from a monomer structure contained therein of 0.01 to 0.

25.

4. 2. The composition for sealing an organic light-emitting device according to claim 1, wherein the monomer represented by Chemical Formula 1 is at least one selected from the group consisting of 1,14-tetradecanediol di(meth)acrylate, 1,15-pentadecanediol di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, 1,17-heptadecanediol di(meth)acrylate, and 1,18-octadecanediol di(meth)acrylate.

5. 2. The composition for sealing an organic light-emitting device according to claim 1, wherein the monomer represented by Chemical Formula 2 is at least one selected from the group consisting of isotetradecyl (meth)acrylate, isopentadecyl (meth)acrylate, isohexadecyl (meth)acrylate, isoheptadecyl (meth)acrylate, and isooctadecyl (meth)acrylate.

6. 2. The composition for sealing an organic light-emitting device according to claim 1, wherein the monomer represented by Chemical Formula 3 is at least one selected from the group consisting of bisphenol A ethylene oxide diacrylate, bisphenol A ethylene oxide dimethacrylate, bisphenol A ethoxylate diacrylate, bisphenol A ethoxylate diacrylate, bisphenol A polyethoxylate diacrylate, and bisphenol A diacrylate.

7. The composition for sealing an organic light emitting device according to claim 1 , wherein the photocurable monomer represented by Chemical Formula 4 is ethylene propylene diene monomer (EPDM).

8. 2. The composition for sealing an organic light-emitting element according to claim 1, wherein the photopolymerization initiator is at least one selected from the group consisting of triazines, acetophenones, benzophenones, thioxanthones, benzoins, phosphorus compounds, oximes, and mixtures thereof.

9. The composition for sealing an organic light-emitting device according to claim 1 , wherein the photopolymerization initiator is contained in an amount of 0.1 to 10 wt % based on the total weight of the composition.

10. The composition for sealing an organic light-emitting element according to claim 1 , further comprising at least one additive selected from the group consisting of a surfactant, a curing accelerator, and an antioxidant.

11. An organic light-emitting display device comprising a sealing part containing the composition for sealing an organic light-emitting element according to any one of claims 1 to 10.

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