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

Abstract

The present invention relates to an encapsulating composition for an organic light-emitting element and an organic light-emitting display device including the same, which 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 also relates to an encapsulating composition for an organic light-emitting element and an organic light-emitting display device including the same, which has low dielectric constant characteristics so as to improve touch sensitivity.

Description

[Technical Field]

[0001] The present invention relates to an encapsulating composition for an organic light-emitting element and an organic light-emitting display device including the same, which 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 also relates to an encapsulating composition for an organic light-emitting element and an organic light-emitting display device including the same, which has low dielectric constant characteristics so as to improve the touch sensitivity of a touch panel. [Background technology]

[0002] The organic layer materials and electrodes constituting 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 capable of protecting the organic materials and electrodes is required. Such a protective layer is usually formed in a laminated structure of one or more organic and inorganic layers to effectively block external moisture and oxygen.

[0003] Recently, capacitive touch panels using organic light-emitting devices have become increasingly popular. Capacitive touch panels detect touches based on a change in capacitance when a conductor comes into contact with the touch panel. For example, 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 stacked 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 an encapsulating composition for an organic light-emitting device, which 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 has 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-mentioned problems, and is characterized in that it contains a photocurable monomer containing all of the monomers represented by the following chemical formulas 1 to 4, and a photopolymerization initiator, and has a dielectric constant of 2.65 or less in the frequency range of 100 KHz to 1 MHz.

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[0010] In the above chemical formulas 1 to 4, R1 to R3 each independently represent a (meth)acryloyl group; R4 is a substituted or unsubstituted C 6-12 is a bridged cycloalkyl group of the formula: R5 is a vinyl group or a (meth)acryloyl group; L1 is a single bond or an alkylene group; n is 14 to 18; m is 5 to 15; p is an integer between 0 and 10.

[0011] The sealing composition for the organic light emitting device may have a viscosity of 10 to 30 cPs.

[0012] The photocurable monomer may be contained in an amount of 20 to 99% by weight based on the total weight of the composition.

[0013] The (meth)acrylate represented by Chemical Formula 1 may be 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.

[0014] The (meth)acrylate represented by Chemical Formula 2 may be 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.

[0015] The (meth)acrylate represented by Chemical Formula 3 may be at least one selected from the group consisting of isobornyl (meth)acrylate, norbornylmethyl (meth)acrylate, 3-methyl-2-norbornylmethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tricyclodecanyl (meth)acrylate, and adamantyl (meth)acrylate.

[0016] The monomer represented by Formula 4 may be a monomer represented by Formula 5 or Formula 6 below.

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[0019] The photopolymerization initiator may be at least one selected from the group consisting of triazine-based, acetophenone-based, benzophenone-based, thioxanthone-based, benzoin-based, phosphorus-based, oxime-based, and mixtures thereof.

[0020] The photopolymerization initiator may be contained in an amount of 0.1 to 10% by weight based on the total weight of the composition.

[0021] The sealing composition for the organic light emitting device may further include at least one additive selected from the group consisting of a surfactant, a curing accelerator, and an antioxidant.

[0022] The organic light-emitting display device of the present invention is characterized by including a sealing part containing the sealing composition for the organic light-emitting element. [Effects of the Invention]

[0023] When the encapsulating composition for an 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, and also has low dielectric constant characteristics, thereby providing an excellent touch feeling for a touch panel. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a diagram illustrating an example of an organic light emitting display device according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0026] When assigning reference numerals to components in each drawing, it should be noted that the same reference numerals are assigned to the same components whenever possible, even if they are displayed in different drawings. Furthermore, when describing the present invention, detailed descriptions of known structures or functions related to the present invention will be omitted if it is determined that such descriptions may obscure the gist of the present invention.

[0027] 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 there can also be another component "coupled," "bonded," or "connected" between the components. Also, when a component such as a layer, film, region, or plate is described as being "on" or "above" another component, this does not only mean that it is "directly on" the other component, but can also include the case where there is another component between them. Conversely, when a component is described as being "directly on" another part, it means that there is no other part between them.

[0028] As used in the present specification, "(meth)acrylic" means acrylic and / or methacrylic.

[0029] As used herein, unless otherwise specified, "alkyl group" means a radical of a saturated aliphatic functional group having 1 to 60 carbon atoms linked by single bonds, including straight-chain alkyl groups, branched-chain alkyl groups, cycloalkyl (alicyclic) groups, alkyl-substituted cycloalkyl groups, cycloalkyl-substituted alkyl groups, and the like.

[0030] The term "alkylene group" as used in the present specification refers to alkanediyl groups linked by a saturated hydrocarbon without a double bond, and has two linking groups.

[0031] Unless otherwise specified, the term "substituted" in the term "substituted or unsubstituted" used in the specification of the present invention means 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 at least one heteroatom selected from the group consisting of an arylalkenyl group, a silane group, a boron group, and O, N, S, Si, and P 2-20 The term "substituted" means that the heterocyclic group may be substituted with one or more substituents selected from the group consisting of, but is not necessarily limited to, these substituents.

[0032] The term "dielectric constant" used in the present specification means a value measured by a capacitance method for an organic layer including the encapsulating composition of the organic light emitting device according to the present invention.

[0033] The term "viscosity" used in the present specification means a value measured using a rotational viscometer for an organic layer including the sealing composition of the organic light emitting device according to the present invention.

[0034] The encapsulating composition for organic light-emitting devices according to the present invention includes a photocurable monomer containing all of the (meth)acrylate monomers represented by the following chemical formulas 1 to 4, and a photopolymerization initiator, and has a dielectric constant of 2.65 or less in a frequency range of 100 KHz to 1 MHz, and the viscosity of the composition may be 10 to 30 cPs.

[0035] The photocurable monomer contains all of the (meth)acrylates represented by the following chemical formulas 1 to 4, and a photopolymerization initiator, and the composition for sealing an organic light-emitting element has a dielectric constant of 2.65 or less in a frequency range of 100 KHz to 1 MHz:

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[0040] In the above chemical formulas 1 to 4, R1 to R3 each independently represent a (meth)acryloyl group; R4 is a substituted or unsubstituted C 6-12 is a bridged cycloalkyl group of the formula: R5 is a vinyl group or a (meth)acryloyl group; L1 is a single bond or an alkylene group; n is 14 to 18; m is 5 to 15; p is an integer between 0 and 10.

[0041] The photocurable monomer may be contained in an amount of 20 to 99% by weight based on the total weight of the composition.

[0042] More specifically, the (meth)acrylate represented by Chemical Formula 1 may be 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, but is not necessarily limited thereto.

[0043] In addition, the (meth)acrylate represented by Chemical Formula 2 may be 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, but is not necessarily limited thereto.

[0044] The (meth)acrylate represented by Chemical Formula 3 may be at least one selected from the group consisting of isobornyl (meth)acrylate, norbornylmethyl (meth)acrylate, 3-methyl-2-norbornylmethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tricyclodecanyl (meth)acrylate, and adamantyl (meth)acrylate, but is not necessarily limited thereto.

[0045] The monomer represented by Formula 4 may be a monomer represented by Formula 5 or Formula 6 below, but is not necessarily limited thereto.

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[0048] The encapsulating composition for an organic light emitting device according to the present invention includes a photopolymerization initiator capable of curing the photocurable monomer through UV irradiation, etc. 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.

[0049] 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. , 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 mixtures thereof.

[0050] 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-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, or a mixture thereof.

[0051] The benzophenone 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.

[0052] The thioxanthone may be thioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone, or mixtures thereof.

[0053] The benzoin-based solvent may be benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzil dimethyl ketal, or a mixture thereof.

[0054] The phosphorus system can be bisbenzoylphenylphosphine oxide, benzoyldiphenylphosphine oxide, or a mixture thereof.

[0055] The oximes may be 2-(o-benzoyloxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione, and 1-(o-acetyloxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanol, or mixtures thereof.

[0056] The photopolymerization initiator is preferably included in an amount of 0.1 to 10 wt % based on the total weight of the composition, because when the photopolymerization initiator is included in this content range, photopolymerization can occur sufficiently upon exposure, and outgassing and reduced reliability due to unreacted initiator remaining after photopolymerization can be prevented.

[0057] The encapsulating composition for 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.

[0058] The encapsulating composition for an organic light emitting device according to the present invention has a low dielectric constant of 2.65 or less in a frequency range of 100 KHz to 1 MHz, and therefore, when the encapsulating composition is applied to a touch panel, excellent touch sensitivity can be achieved.

[0059] Furthermore, the sealing composition for an organic light emitting device according to the present invention preferably has a viscosity of 10 to 30 cPs, because the processability of the composition can be further improved within this viscosity range.

[0060] The organic light-emitting display device of the present invention includes a sealing part containing the sealing composition for the organic light-emitting element.

[0061] 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 illustrated in FIG. 1 includes a substrate 100, an organic light emitting element 200 disposed on the substrate 100, and an encapsulating unit 300 disposed on the organic light emitting element 200. While the encapsulating unit 300 is illustrated 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 multi-layer structures, 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.

[0062] The encapsulation unit 300 may be formed of an organic barrier layer for sealing or encapsulating the organic light emitting display device, and may be formed by photo-curing the encapsulating composition for the organic light emitting device according to the present invention.

[0063] The sealing composition (organic barrier layer material) can be applied by inkjet, vacuum deposition, spin coating, or slit coating, and an initiator can be used for photo-curing.

[0064] EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples of the encapsulating composition for an organic light-emitting device according to the present invention, but the present invention is not limited to the following examples. [Example]

[0065] The photocurable monomer and the photoinitiator (BAPO) were mixed in the weight ratios shown in Table 1 below to prepare sealing compositions for the organic light-emitting devices of Examples 1 to 4 and Comparative Examples 1 to 5.

[0066] The prepared composition was then stirred for 12 hours and filtered through a PTFE filter with a pore size of 0.45 μm.

[0067] The filtered encapsulating composition for the organic light emitting device was applied by spin coating 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 an encapsulating film. The dielectric constant and viscosity were measured as follows.

[0068] Dielectric constant: The encapsulating composition for the organic light emitting device was coated on the lower electrode to a thickness of 8.0 μm or more and cured. Then, the upper electrode Ag was deposited to a thickness of 1,000 Å. The fabricated test specimen was measured using a Keysight E4980A, and its dielectric constant was calculated.

[0069] Viscosity: The viscosity of the liquid composition for sealing an organic light-emitting device was measured using a rotational viscometer.

[0070] As a result, the dielectric constant of the sealing films formed using the sealing compositions for the organic light-emitting devices of Examples 1 to 4 of the present invention was 2.65 F / m or less, while the dielectric constant of the sealing films formed in Comparative Examples 1 to 5 exceeded 2.65 F / m. Therefore, it was confirmed that the touch panel using the sealing film prepared according to the present invention exhibited superior touch sensitivity.

[0071] [Table 1]

[0072] *DVSO: 1,3-Divinyltetramethyldisiloxane (CAS: 2627-95-4) *DMASO: 1,3-bis(3-methacryloxypropyl)tetramethyldisiloxane (CAS: 18547-93-8) *TDMA: 1,14-Tetradecanediol dimethacrylate (CAS: 168473-14-1) *IBOMA: Isobornyl Acrylate (CAS: 5888-33-5) *ISTA: Isooctadecyl Acrylate (CAS: 93841-48-6) *BAPO: Bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (CAS: 162881-26-7)

[0073] The above description is merely illustrative of the present invention, and various modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the specification of the present invention are for the purpose of illustrating the present invention, rather than limiting the present invention, and the spirit and scope of the present invention are not limited by these embodiments. The scope 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]

[0074] 100 boards 200 Organic light-emitting devices 300 Sealing part 310 First sealing portion 320 Second sealing part

Claims

1. The composition includes a photocurable monomer containing all of the (meth)acrylates represented by the following chemical formulas 1 to 4, and a photopolymerization initiator, A composition for sealing an organic light-emitting device, having a dielectric constant of 2.65 or less at a frequency in the range of 100 Khz to 1 Mhz: 【Chemistry 1】 【Chemistry 2】 【Transformation 3】 【Chemistry 4】 In the above chemical formulas 1 to 4, R １ ~R ３ are each independently a (meth)acryloyl group, R ４ is a substituted or unsubstituted C ６－１２ is a bridged cycloalkyl group of the formula: R ５ is a vinyl group or a (meth)acryloyl group, L 1 is a single bond or an alkylene group, n is 14 to 18; m is 5 to 15; p is an integer from 0 to 10.

2. The sealing composition for the organic light-emitting element has a viscosity of 10 to 30 cPs. The composition for sealing an organic light-emitting element according to claim 1 .

3. The photocurable monomer comprises 20 to 99 wt % based on the total weight of the composition; The composition for sealing an organic light-emitting element according to claim 1 .

4. The (meth)acrylate 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. The composition for sealing an organic light-emitting element according to claim 1 .

5. The (meth)acrylate 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. The composition for sealing an organic light-emitting element according to claim 1 .

6. The (meth)acrylate represented by Chemical Formula 3 is at least one selected from the group consisting of isobornyl (meth)acrylate, norbornylmethyl (meth)acrylate, 3-methyl-2-norbornylmethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tricyclodecanyl (meth)acrylate, and adamantyl (meth)acrylate. The composition for sealing an organic light-emitting element according to claim 1 .

7. The monomer represented by Chemical Formula 4 is a monomer represented by Chemical Formula 5 or Chemical Formula 6: The composition for sealing an organic light-emitting element according to claim 1 . 【Transformation 5】 【Transformation 6】

8. The photopolymerization initiator is at least one selected from the group consisting of triazine-based, acetophenone-based, benzophenone-based, thioxanthone-based, benzoin-based, phosphorus-based, oxime-based, and mixtures thereof. The composition for sealing an organic light-emitting element according to claim 1 .

9. The photoinitiator comprises 0.1 to 10 wt % based on the total weight of the composition; The composition for sealing an organic light-emitting element according to claim 1 .

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

11. The organic light-emitting element according to claim 1, further comprising a sealing portion containing the sealing composition for the organic light-emitting element. Organic light-emitting display device.

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