Composition for sealing organic light-emitting element and organic light-emitting display device comprising same

Abstract

The present invention relates to a composition for sealing an organic light-emitting element and an organic light-emitting display device comprising the same, and more particularly, to a composition for sealing an organic light-emitting element and an organic light-emitting display device comprising the same, the composition for sealing an organic light-emitting element and an organic light-emitting display device including the same have a low dielectric constant characteristic to improve touch sensitivity.

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, and more particularly, to a composition for sealing an organic light-emitting element and an organic light-emitting display device including the same, which can not only ensure the performance and lifespan of an organic light-emitting element by effectively blocking moisture or oxygen entering from the outside, but also has a low dielectric constant characteristic to improve the touch sensitivity of a touch panel. Background Art

[0002] There is a problem in that the light-emitting characteristics and lifespan of the organic layer materials, electrodes, etc. constituting an organic light-emitting element deteriorate due to external moisture or oxygen. Therefore, a protective layer that can protect the organic materials and electrodes is required. In order to effectively block external moisture or oxygen, such a protective layer is generally formed of one or more organic layers and inorganic layers in a laminated structure.

[0003] In recent years, capacitive touch panels using organic light-emitting elements have been widely adopted. Such a capacitive touch panel senses touch by a change in capacitance when a conductor comes into contact with the touch panel. In the case of a high dielectric constant material, there is a tendency for the touch sensitivity to decrease due to severe polarization when an external electric field is applied. Therefore, it is necessary to develop a sealing composition for an organic layer used in a laminated structure having excellent touch sensitivity of a touch panel and a low dielectric constant characteristic. Summary of the Invention

[0004] Technical Problem

[0005] An object of the present invention is to provide a composition for sealing an organic light-emitting element and an organic light-emitting display device including the same, which can not only ensure the performance and lifespan of an organic light-emitting element by effectively blocking moisture or oxygen entering from the outside, but also has a low dielectric constant characteristic to make the touch sensitivity of a touch panel excellent.

[0006] Means for Solving the Problem

[0007] The present invention is a composition for sealing an organic light-emitting element developed to solve the above problems, characterized in that it contains a photocurable monomer and a photoinitiator and has a dielectric constant of 2.60 or less in the frequency range of 100 Khz to 1 MHz, and the photocurable monomer simultaneously contains monomers represented by the following Chemical Formulas 1 to 3.

[0008] [Chemical Formula 1]

[0009]

[0010] [Chemical Formula 2]

[0011]

[0012] [Chemical Formula 3]

[0013]

[0014] In the above Chemical Formulas 1 to 3,

[0015] R1 to R3 are each independently a (meth)acryloyl group,

[0016] R4 is a substituted or unsubstituted C 1-20 alkyl group,

[0017] m is from 5 to 15,

[0018] n is from 1 to 10.

[0019] Another invention is an organic light-emitting display device, characterized in that it contains the above-described composition for sealing an organic light-emitting element.

[0020] Advantages of the Invention

[0021] When using the composition for sealing an organic light-emitting element of the present invention to form a sealing portion of an organic light-emitting display device, the following effects are achieved: not only can the performance and lifespan of the organic light-emitting element be ensured by effectively blocking moisture or oxygen entering from the outside, but also it has a low dielectric constant property, so the touch sensitivity of the touch panel is excellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is an illustrative view of an organic light-emitting display device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0024] When assigning reference numerals to the components of each drawing, it should be noted that the same components will be assigned the same reference numerals as much as possible even in different drawings. In addition, when describing the present invention, if a detailed description of a related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

[0025] When a certain component is described as "connected", "bonded", or "joined" to another component, the component may be directly connected or joined to the other component, but there may also be other components "connected", "bonded", or "joined" between the components. In addition, when a component such as a layer, film, region, or plate is described as being "above" or "on" another component, it includes not only the case where it is directly "above" the other component, but also the case where there are other components in between. Conversely, when a certain component is described as being directly "above" another component, it means that there is no other part in between.

[0026] As used herein, the term "(meth)acryloyl" means "acryloyl" and / or "methacryloyl".

[0027] As used herein, the term "alkyl" refers to a saturated aliphatic functional group radical having 1 to 60 carbons connected by single bonds, represented by straight-chain alkyl, branched-chain alkyl, cycloalkyl (alicyclic group), alkyl-substituted cycloalkyl, and cycloalkyl-substituted alkyl, unless otherwise specified.

[0028] As used herein, the term "alkylene" refers to alkanediyl groups formed by connecting saturated hydrocarbons without double bonds and having two connecting bonds.

[0029] In addition, unless otherwise clearly specified, the term "substituted or unsubstituted" as used herein, "substituted" means that it can be substituted by one or more substituents selected from the group consisting of deuterium, halogen, amino, nitrile, nitro, C 1-20 alkyl, C 1-20 alkoxy, C 1-20 alkylamino, C 1-20 alkylthienyl, C 6-20 arylthienyl, C 2-20 alkenyl, C 2-20 alkynyl, C 3-20 cycloalkyl, C 6-20 aryl, deuterium-substituted C 6-20 aryl, C 8-20 arylalkenyl, silyl, boranyl, and C 2-20 heterocyclic group containing at least one heteroatom selected from the group consisting of O, N, S, Si, and P, but is not necessarily limited to these substituents.

[0030] As used herein, the term "dielectric constant" refers to the value measured by the capacitance method for the organic layer of the organic light-emitting element sealing composition containing the present invention.

[0031] As used in this specification, the term "viscosity" refers to the value measured for the organic layer of the above-described organic light-emitting element sealing composition containing the present invention using a rotational viscometer.

[0032] The organic light-emitting element sealing composition of the present invention is characterized by containing a photocurable monomer and a photoinitiator and having a dielectric constant of 2.65 or less at a frequency in the range of 100 kHz to 1 MHz. The above photocurable monomer simultaneously contains monomers represented by the following Chemical Formulas 1 to 3, and the viscosity of the above composition may be 10 to 20 cPs.

[0033] [Chemical Formula 1]

[0034]

[0035] [Chemical Formula 2]

[0036]

[0037] [Chemical Formula 3]

[0038]

[0039] In the above Chemical Formulas 1 to 3,

[0040] R1 to R3 are each independently (meth)acryloyl,

[0041] R4 is a substituted or unsubstituted C 1-20 alkyl,

[0042] m is 5 to 15,

[0043] n is 1 to 10.

[0044] The monomer represented by the above 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. The weight-average molecular weight of the monomer represented by the above Chemical Formula 1 is preferably 500 to 3000.

[0045] In addition, the monomer represented by the above Chemical Formula 2 may be one or more selected from the group consisting of isomyristyl (meth)acrylate, isopentadecyl (meth)acrylate, isohexadecyl (meth)acrylate, isopheptadecyl (meth)acrylate, and isooctadecyl (meth)acrylate, but is not necessarily limited thereto.

[0046] The monomer represented by the above Chemical Formula 3 may be one or more selected from the group consisting of poly-1-pentene, poly-1-hexene, poly-1-heptene, poly-1-octene, poly-1-nonene, poly-1-decene, poly-1-undecene, poly-1-dodecene, poly-1-tridecene, poly-1-tetradecene, and poly-1-hexadecene, but is not necessarily limited thereto.

[0047] The photocurable monomer of the present invention may further contain one or more monomers selected from the group consisting of the compounds represented by the following Chemical Formulas 4 to 6.

[0048] [Chemical Formula 4]

[0049] R5-A-R6

[0050] [Chemical Formula 5]

[0051] R7-B

[0052] [Chemical Formula 6]

[0053] R8-L-O-Ar1

[0054] In the above Chemical Formulas 4 to 6,

[0055] each of R5 to R8 is independently (meth)acryloyl, A is a substituted or unsubstituted cycloalkylene group having two fused rings forming a bridge, B is a substituted or unsubstituted bridged cycloalkyl group having, L is a direct bond or an alkylene group having, and Ar1 is an aryl group having. 9-20 of C 6-12 of C 1-10 of C 6-60 of C

[0056] The monomer represented by the above Chemical Formula 4 may be the compound represented by the following Chemical Formula 7 (Tricyclodecanedimethanol Diacrylate, TCDDA), but is not necessarily limited thereto.

[0057] [Chemical Formula 7]

[0058]

[0059] The monomer represented by the above Chemical Formula 5 may be the compound represented by the following Chemical Formula 8 (Isobornyl Acrylate, IBOMA), but is not necessarily limited thereto.

[0060] [Chemical Formula 8]

[0061]

[0062] The monomer represented by the above chemical formula 6 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.

[0063]

[0064] Based on the total weight of the above photo-curable monomers, the content of the above photo-curable monomers is preferably 20 to 99% by weight.

[0065] More specifically, based on the total weight of the composition, the content of the monomer represented by the above chemical formula 1 may be 15 to 60% by weight, the content of the (meth)acrylate represented by the above chemical formula 2 may be 30 to 70% by weight, the content of the monomer represented by the above chemical formula 3 may be 1 to 25% by weight, and the content of the monomers represented by the above chemical formulas 4 to 6 may be 1 to 35% by weight.

[0066] The composition for sealing an organic light-emitting element of the present invention contains a photoinitiator that can cure the above photo-curable monomers by UV irradiation or the like. The above photoinitiator is not particularly limited as long as it is a general photoinitiator that can perform a photo-curing reaction. As an example, the above photoinitiator may include a triazine-based, acetophenone-based, benzophenone-based, thioxanthone-based, benzoin-based, phosphorus-based, oxime-based, or a mixture thereof.

[0067] As the above triazine-based, it may be 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, 2-(p-tolyl)-4,6-bis(trichloromethyl)-s-triazine, 2-biphenyl-4,6-bis(trichloromethyl)-s-triazine, bis(trichloromethyl)-6-styryl-s-triazine, 2-(naphtho-1-yl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxynaphtho-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.

[0068] As the above-mentioned acetophenone series, it may be 2,2'-diethoxyacetophenone, 2,2'-dibutoxyacetophenone, 2-

[0230] hydroxy-2-methylpropiophenone, p-tert-butyltrichloroacetophenone, p-tert-butyldichloroacetophenone, 4-chloro

[0231] acetophenone, 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.

[0069] As the above-mentioned benzophenone series, it 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.

[0070] As the above-mentioned thioxanthone series, it may be thioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chlorothioxanthone, or a mixture thereof.

[0071] As the above-mentioned benzoin series, it may be benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzil dimethyl ketal, or a mixture thereof.

[0072] As the above-mentioned phosphorus series, it may be bis(benzoylphenyl)phosphine oxide, benzoyldiphenylphosphine oxide, or a mixture thereof.

[0073] As the above-mentioned oxime series, it may be 2-(o-benzoyl oxime)-1-[4-(phenylthio)phenyl]-1,2-octanedione and 1-(o-acetyl oxime)-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethanone, or a mixture thereof.

[0074] Based on the total weight of the composition, the content of the above-mentioned photoinitiator is preferably 0.1 to 10% by weight. This is because when the photoinitiator is included in the above content range, not only can sufficient photopolymerization occur during exposure, but also the generation of outgas and the reduction of reliability due to the unreacted initiator remaining after photopolymerization can be prevented.

[0075] The composition for sealing an organic light-emitting element of the present invention may further additionally contain one or more additives selected from the group consisting of a surfactant, a curing accelerator, and an antioxidant. In particular, the surfactant is beneficial for inducing the dispersion of the composition.

[0076] The composition for sealing an organic light-emitting element of the present invention has a low dielectric constant property with a dielectric constant of 2.60 or less in the frequency range of 100 kHz to 1 MHz. Therefore, when the above sealing composition is applied to a touch panel, it has an excellent touch sensitivity effect.

[0077] In addition, the viscosity of the composition for sealing an organic light-emitting element of the present invention is preferably 10 to 20 cPs, because the processability of the composition can be further improved within the above viscosity range.

[0078] Another invention of the present invention is an organic light-emitting display device, which includes a sealing portion containing the above composition for sealing an organic light-emitting element.

[0079] Figure 1 It is an exemplary diagram of an organic light-emitting display device according to an embodiment of the present invention. Figure 1 The disclosed organic light-emitting display device includes a substrate 110, an organic light-emitting element 200 disposed on the substrate 110, and a sealing portion 300 disposed on the organic light-emitting element 200. At this time, the disclosed sealing portion 300 is a multi-layer composed of a first sealing layer 310 and a second sealing layer 320, but the present invention may include all configurations in which the sealing portion 300 has two or four or more layers. When the sealing portion 300 is composed of a multi-layer of two layers, it may include an inorganic barrier layer and an organic barrier layer. For example, when the first sealing layer 310 is an inorganic barrier layer, the second sealing layer 320 may be an organic barrier layer, but the lamination order is not limited thereto.

[0080] The above sealing portion 300 may form 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 an organic light-emitting element of the present invention.

[0081] The above sealing composition (organic barrier layer material) may be coated by inkjet, vacuum evaporation, spin coating or slot coating methods, and an initiator may be used during photocuring.

[0082] Hereinafter, examples of the composition for sealing an organic light-emitting element of the present invention will be given to specifically illustrate the present invention, but the present invention is not limited by the following examples.

[0083] [Examples]

[0084] The compositions for sealing an organic light-emitting element of Examples 1 to 4 were prepared by mixing according to the weight ratios of photocurable monomers and photoinitiator (TPO) shown in Table 1 below.

[0085] Then, the compositions prepared above were stirred for 12 hours and filtered using a PTFE filter with a pore size of 0.45 μm.

[0086] The above-filtered composition for sealing an organic light-emitting element was formed into a thickness of 8.0 μm or more by spin coating, and then irradiated with a light amount of 1 J using a UV exposure machine to form a sealing film. The dielectric constant and viscosity were measured by the following methods.

[0087] Dielectric constant: The composition for sealing an organic light-emitting element was coated on the lower electrode with a thickness of 8.0 μm or more and cured. Then, the upper electrode Ag was deposited with a thickness. The dielectric constant was calculated after measuring the fabricated test piece using E4980A from Keysight Technologies.

[0088] Viscosity: The viscosity of the liquid composition for sealing an organic light-emitting element was measured using a rotational viscometer.

[0089] As a result, the dielectric constants of the sealing films formed from the compositions for sealing organic light-emitting elements of Examples 1 to 4 of the present invention all obtained values of 2.60 F / m or less. Thus, it was confirmed that a touch panel using the sealing film manufactured according to the present invention can achieve a more excellent touch sensitivity effect.

[0090] [Table 1]

[0091]

[0092] TDMA: 1,14-Tetradecanediol dimethacrylate (CAS: 168473-14-1)

[0093] TCDDA: Tricyclodecanedimethanol Diacrylate (CAS: 42594-17-2)

[0094] IBOMA: Isobornyl Acrylate (CAS: 5888-33-5)

[0095] ISTA: Isooctadecyl acrylate (CAS: 93841-48-6)

[0096] PDC: Poly 1-Decene (CAS: 68037-01-4)

[0097] BAPO: Bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (CAS: 162881-26-7)

[0098] The above description is only an illustrative description of the present invention. Those of ordinary skill in the technical field to which the present invention pertains should be able to make various changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in this specification are intended to illustrate rather than limit the present invention, and the idea and scope of the present invention will not be limited by these embodiments. The protection scope of the present invention should be interpreted according to the scope of the appended claims, and all technologies within the equivalent scope should be interpreted as being included within the scope of the claims of the present invention.

[0099] [Symbol Description]

[0100] 100: Substrate,

[0101] 200: Organic light-emitting element,

[0102] 300: Sealing portion,

[0103] 310: First sealing portion,

[0104] 320: Second sealing portion.

Claims

1. An organic light-emitting element sealing composition, which contains a photocurable monomer and a photoinitiator, and has a dielectric constant of 2.65 or less at a frequency in the range of 100 kHz to 1 MHz. The photocurable monomer simultaneously contains monomers represented by the following Chemical Formulas 1 to 3. [Chemical Formula 1] [Chemical Formula 2] [Chemical Formula 3] In Chemical Formulas 1 to 3, R1 to R3 are each independently a (meth)acryloyl group. R4 is a substituted or unsubstituted C 1-20 alkyl group, m is 5 to 15. n is 1 to 10.

2. The organic light-emitting element sealing composition according to claim 1, wherein the photocurable monomer further contains one or more monomers selected from the group consisting of compounds represented by the following Chemical Formulas 4 to 6. [Chemical Formula 4] R5-A-R6 [Chemical Formula 5] R7-B [Chemical Formula 6] R8-L-O-Ar1 In Chemical Formulas 4 to 6, R5 to R8 are each independently a (meth)acryloyl group. A is a substituted or unsubstituted cycloalkylene of two fused rings forming a bridge 9-20 and B is C 6-12 substituted or unsubstituted bridged cycloalkyl, L is a direct bond or an alkylene group of 1-10 1-10 and Ar1 is an aryl group of C 6-60 .

3. The organic light-emitting element sealing composition according to claim 2, wherein, based on the total weight of the composition, the content of the photocurable monomer is 20 to 99% by weight.

4. The organic light-emitting element sealing composition according to claim 1, wherein the monomer represented by Chemical Formula 1 is 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.

5. The organic light-emitting element sealing composition according to claim 1, wherein the monomer represented by Chemical Formula 2 is one or more selected from the group consisting of isomyristyl (meth)acrylate, isopentadecyl (meth)acrylate, isohexadecyl (meth)acrylate, isooctadecyl (meth)acrylate, and isooctadecyl (meth)acrylate.

6. The organic light-emitting element sealing composition according to claim 1, wherein the monomer represented by Chemical Formula 3 is one or more selected from the group consisting of poly-1-pentene, poly-1-hexene, poly-1-heptene, poly-1-octene, poly-1-nonene, poly-1-decene, poly-1-undecene, poly-1-dodecene, poly-1-tridecene, poly-1-tetradecene, and poly-1-hexadecene.

7. The organic light-emitting element sealing composition according to claim 1, wherein the photocurable monomer represented by Chemical Formula 4 is a compound represented by the following Chemical Formula 7. [Chemical Formula 7] 8. The organic light-emitting element sealing composition according to claim 1, wherein the photocurable monomer represented by Chemical Formula 5 is a compound represented by the following Chemical Formula 8. [Chemical Formula 8] 9. The organic light-emitting element sealing composition according to claim 1, wherein the photocurable monomer represented by Chemical Formula 6 is a monomer selected from the group consisting of the following Chemical Formulas A-1 to A-3.

10. The composition for sealing an organic light-emitting element according to claim 1, wherein the photoinitiator is one or more selected from the group consisting of triazine-based, acetophenone-based, benzophenone-based, thioxanthone-based, benzoin-based, phosphorus-based, oxime-based, and mixtures thereof.

11. The composition for sealing an organic light-emitting element according to claim 1, wherein the content of the photoinitiator is 0.1 to 10% by weight based on the total weight of the composition.

12. The composition for sealing an organic light-emitting element according to claim 1, wherein the composition for sealing an organic light-emitting element further comprises one or more additives selected from the group consisting of surfactants, curing accelerators, and antioxidants.

13. An organic light-emitting display device comprising a sealing portion containing the composition for sealing an organic light-emitting element according to any one of claims 1 to 12.

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