Organic light emitting display device

Abstract

The present disclosure relates to an organic light emitting display device, and an organic light emitting display device according to an exemplary embodiment of the present disclosure includes a filler filling a gap between a second substrate and an organic light emitting diode, and a dam structure disposed in a non-display area and surrounding the filler. At least one of the dam structure and the filler includes a getter. The getter of the present disclosure is composed of magnesium oxide particles whose surface is modified by a first surface modification part made of an amino silane-based compound and a second surface modification part bonded to the first surface modification part and made of a compound including an acrylate group and a methacrylate group. Accordingly, an organic light emitting display device having high transparency and whose lifespan and durability are improved by minimizing the penetration of water and oxygen can be provided.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0137019, filed with the Korean Intellectual Property Office on October 21, 2020, the disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to an organic light-emitting display device, and more particularly to an organic light-emitting display device having high transparency and whose lifespan and durability are improved by minimizing the permeation of water and oxygen. Background Technology

[0004] Recently, as society has entered the information age, the field of displays that visually represent electronic information signals is developing rapidly. Building upon this rapid development, various display devices with excellent properties such as thinness, light weight, and low power consumption have been developed. Specific examples of the display devices mentioned above may include liquid crystal displays (LCDs), plasma display panels (PDPs), field emission displays (FEDs), organic light-emitting diode displays (OLEDs), and the like.

[0005] In particular, organic light-emitting diode (OLED) displays are self-emissive and offer advantages over other display devices in terms of fast response time, high luminous efficiency, high brightness, and wide viewing angle. Therefore, OLED displays have attracted widespread attention. Furthermore, organic light-emitting diodes (OLEDs), used in OLED displays, are next-generation light sources with self-luminous properties. OLEDs outperform liquid crystal displays (LCDs) in terms of viewing angle, contrast ratio, response time, and power consumption.

[0006] However, organic light-emitting diodes (OLEDs) are based on organic materials and are susceptible to the effects of water or oxygen, which reduces their lifespan and degrades their reliability. Therefore, various techniques for sealing OLEDs have been used to minimize the degradation caused by water or oxygen.

[0007] Meanwhile, the demand for transparent organic light-emitting diode (OLED) display devices has recently increased. In transparent OLED display devices, organic layers such as the light-emitting layer and electrodes are made transparent, allowing objects behind the display device to be seen. To realize a transparent OLED display device, the materials sealing the organic light-emitting diodes, as well as the organic layers and electrodes, need to be transparent. Therefore, there is a need to develop sealing elements that minimize degradation caused by water or oxygen and possess high transparency. Summary of the Invention

[0008] One objective of this disclosure is to provide an organic light-emitting display device that exhibits high transparency, minimized degradation, and improved lifespan and durability through the use of a getter. The getter is used as a dam structure disposed in non-display areas and / or as a filler to fill the gap between the organic light-emitting diode and the upper substrate. The getter possesses excellent resistance to water and oxygen permeation and improved light transmittance.

[0009] Another inventive objective of this disclosure is to provide an organic light-emitting display device that maintains transparency because there is no color change before and after water adsorption. This organic light-emitting display device can maintain high resistance to water penetration for a long time because the adsorbed water or oxygen does not desorb.

[0010] Another inventive objective of this disclosure is to provide an organic light-emitting display device that maintains high transparency even when the amount of getter contained in the matrix resin is increased by improving the dispersion of the getter in the matrix resin.

[0011] The inventive objectives of this disclosure are not limited to those mentioned above, and other inventive objectives not mentioned above can be clearly understood by those skilled in the art based on the following description.

[0012] According to one aspect of this disclosure, the organic light-emitting display device includes a first substrate comprising a plurality of sub-pixels and defining a display area and a non-display area surrounding the display area within the first substrate. The organic light-emitting display device further includes a thin-film transistor disposed on the first substrate and an organic light-emitting diode disposed on the thin-film transistor. The organic light-emitting display device also includes a second substrate facing the first substrate and a filling portion filling the gap between the second substrate and the organic light-emitting diode. The organic light-emitting display device further includes a dam structure disposed in the non-display area and surrounding the filling portion. At least one of the dam structure and the filling portion includes a getter. The getter consists of magnesium oxide particles whose surface is modified to be made of an aminosilyl compound and a second surface modified portion bonded to the first surface modified portion and made of a compound comprising acrylate and methacrylate groups.

[0013] Further details of the exemplary embodiments are included in the detailed description and drawings.

[0014] According to this disclosure, getters with excellent resistance to water and oxygen permeation and improved light transmittance are used to improve the transparency of organic light-emitting display devices and minimize degradation. Therefore, the lifespan and durability of organic light-emitting display devices can be improved.

[0015] According to this disclosure, a getter is used that does not change color before and after water adsorption and in which the adsorbed water or oxygen is not easily desorbed. Therefore, a transparent and highly reliable organic light-emitting display device can be provided.

[0016] According to this disclosure, the dispersibility of the getter is improved through chemical bonds between the getter and the matrix resin. Therefore, an organic light-emitting display device can be provided that exhibits improved resistance to water penetration and transparency equal to or higher than that of conventional organic light-emitting display devices, even with increased getter amounts.

[0017] The effects of this disclosure are not limited to the examples above, and many more effects are included in this specification. Attached Figure Description

[0018] The above and other aspects, features and advantages of this disclosure will become more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0019] Figure 1 This is a schematic plan view provided to explain an exemplary embodiment of an organic light-emitting display device according to the present disclosure;

[0020] Figure 2 It is along Figure 1 A schematic cross-sectional view obtained from the straight line I-I' in the diagram;

[0021] Figure 3 This is a schematic diagram provided to explain the configuration of the dam structure of an organic light-emitting display device according to an exemplary embodiment of the present disclosure;

[0022] Figure 4A The X-ray diffraction pattern is based on the magnesium oxide nanoparticles prepared according to Embodiment 1.

[0023] Figure 4B The X-ray diffraction pattern is based on the surface-modified magnesium oxide nanoparticles prepared according to Embodiment 2.

[0024] Figure 4C The X-ray diffraction pattern of the surface-modified magnesium oxide nanoparticles prepared according to Embodiment 3 is shown.

[0025] Figure 5A This is a graph showing the change in weight of magnesium oxide nanoparticles prepared according to Example 1 as a function of relative humidity.

[0026] Figure 5B This is a graph showing the change in weight of the surface-modified magnesium oxide nanoparticles according to Preparation Embodiment 2 as a function of relative humidity.

[0027] Figure 5CThis is a graph showing the change in weight of the surface-modified magnesium oxide nanoparticles according to preparation embodiment 3 as a function of relative humidity.

[0028] Figure 6A It is a graph showing the transmittance of the dam structure according to Embodiment 1A, Comparative Embodiment 1A, and Comparative Embodiment 2A in the visible wavelength range.

[0029] Figure 6B It is a graph showing the transmittance of the dam structure according to Embodiment 1B, Comparative Embodiment 1B, and Comparative Embodiment 2B in the visible wavelength range.

[0030] Figure 6C It is a graph showing the transmittance of the dam structure according to Embodiment 1C, Comparative Embodiment 1C, and Comparative Embodiment 2C in the visible wavelength range.

[0031] Figure 6D This is a graph showing the transmittance of the dam structure according to Embodiment 1D, Comparative Embodiment 1D, and Comparative Embodiment 2D in the visible wavelength range; and

[0032] Figure 7 This is a schematic cross-sectional view of a sample prepared to evaluate its resistance to water penetration. Detailed Implementation

[0033] The advantages and features of this disclosure, and the methods for achieving these advantages and features, will be described with reference to the following and accompanying appendices. Figure 1 The exemplary embodiments described in detail herein will become clearer. However, this disclosure is not limited to the exemplary embodiments disclosed herein, but will be implemented in various forms. Exemplary embodiments are provided by way of example only to enable those skilled in the art to fully understand the disclosure and scope of this disclosure. Therefore, this disclosure will be limited only by the scope of the appended claims.

[0034] The shapes, dimensions, scales, angles, quantities, etc., shown in the accompanying drawings for the purpose of describing exemplary embodiments of this disclosure are merely examples and are not intended to limit the scope of this disclosure. Throughout the specification, similar reference numerals generally denote similar elements. Furthermore, in the description following this disclosure, detailed explanations of known related technologies may be omitted to avoid unnecessarily obscuring the subject matter of this disclosure. Terms such as “comprising,” “having,” and “consisting of” as used herein are generally intended to allow for the addition of additional components, unless these terms use the term “only.” Any singular reference may include the plural form unless explicitly stated otherwise.

[0035] Even if not explicitly stated, components are still interpreted as including the usual tolerance range.

[0036] When using terms such as “on top of,” “above,” “below,” and “adjacent to,” to describe the positional relationship between two parts, one or more parts may be located between the two parts, unless these terms use the terms “immediately adjacent” or “directly.”

[0037] When one element or layer is positioned "on" another element or layer, the other layer or element can be directly inserted onto or between the other element.

[0038] Although the terms "first," "second," etc., are used to describe various components, these components are not limited by these terms. These terms are merely used to distinguish one component from other components. Therefore, within the technical concept of this disclosure, the first component mentioned below can be a second component.

[0039] Throughout the specification, similar reference numerals generally indicate similar components.

[0040] The dimensions and thickness of each component shown in the accompanying drawings are shown for ease of description, but this disclosure is not limited to the dimensions and thickness of the components shown.

[0041] Features of the various embodiments of this disclosure may be combined or integrated with each other in part or in whole and may be technically interconnected and operable in various ways, and these embodiments may be implemented independently of each other or in combination with each other.

[0042] In this specification, a transparent display device refers to a transparent display device in which at least a portion of the screen of the display device as observed by the user is transparent. In this specification, the transparency of a transparent display device refers to the degree of transparency at least when the user can identify an object behind the display device. In this specification, a transparent display device refers to a transparent display device whose transmittance is, for example, equal to or greater than at least 20%.

[0043] In the following, an organic light-emitting display device according to an exemplary embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[0044] Figure 1 This is a schematic plan view provided to explain an exemplary embodiment of an organic light-emitting display device according to the present disclosure. Figure 2 It is along Figure 1 A schematic cross-sectional view obtained from the straight line I-I' in the diagram. Figure 1 and Figure 2 A transparent organic light-emitting display device is illustrated. While transparent organic light-emitting display devices will be described below, this disclosure is not limited thereto. This disclosure can also be applied to non-transparent organic light-emitting display devices whenever necessary.

[0045] Reference Figure 1 and Figure 2 The organic light-emitting display device 100 includes a first substrate 110, a thin film transistor 120, a white organic light-emitting diode (OLED) 140, an encapsulation layer 150, a filling portion 160, a second substrate 170, and a dam structure 180.

[0046] The first substrate 110 is used to support various components of the organic light-emitting display device 100. (Refer to...) Figure 1 The first substrate 110 includes a display area DA and a non-display area NDA. The display area DA refers to the area where multiple pixels are disposed and an image is displayed. Within the display area DA, pixels including light-emitting areas for displaying the image and driving circuitry for driving these pixels are disposed. The non-display area NDA refers to the outer periphery surrounding the display area DA. No image is displayed in the non-display area. Within the non-display area NDA, various lines, driver integrated circuits (ICs), and printed circuit boards for driving the pixels disposed in the display area and the driving circuitry are disposed.

[0047] Reference Figure 1 Multiple subpixels (SPs) are disposed in the display area of ​​the first substrate 110. Each of the multiple subpixels (SPs) is an area for displaying a single color. A white OLED is disposed in each of the multiple subpixels (SPs). The multiple subpixels (SPs) may include red subpixels, green subpixels, and blue subpixels, or may include red subpixels, green subpixels, blue subpixels, and white subpixels. The multiple subpixels (SPs) can be arranged as follows: Figure 1 The form of the matrix shown is limited.

[0048] Each of the plurality of sub-pixels SP in the organic light-emitting display device 100 includes an emitting region EA and a transmissive region TA. The emitting region EA is an area configured to display an image and not transmit external light. The transmissive region TA is an area configured to transmit external light. Therefore, when the organic light-emitting display device 100 is not driven, the user can observe the background, i.e., objects behind the display, through the transmissive region TA. When the organic light-emitting display device 100 is driven, the user can simultaneously observe the image displayed in the emitting region EA and observe the background through the transmissive region TA. The area ratio between the emitting region EA and the transmissive region TA in each sub-pixel SP can be set in various ways according to visibility and transmittance.

[0049] As mentioned above, Figure 1 and Figure 2 The illustration depicts a transparent organic light-emitting display device, but this disclosure is not limited thereto. This disclosure can also be applied to non-transparent organic light-emitting display devices. Non-transparent organic light-emitting display devices may not have a transmissive area or may have a very small transmissive area.

[0050] The first substrate 110 may be made of an insulating material. The first substrate 110 may be a flexible glass substrate or a plastic substrate. For example, a flexible plastic substrate may include materials selected from polyimide, polyethersulfone, polyethylene terephthalate, polyetherimide, polymethyl methacrylate, polystyrene, styrene-acrylnitrile copolymer, silicone-acryl resin, and polycarbonate. However, this disclosure is not limited thereto.

[0051] A buffer layer 131 may be formed on the first substrate 110. The buffer layer 131 is used to protect the various components of the organic light-emitting display device 100 from the penetration of water or oxygen and to inhibit the introduction of impurities remaining on the first substrate 110. The buffer layer 131 may be made of, for example, silicon nitride (SiNx) or silicon oxide (SiOx), but is not limited thereto.

[0052] The buffer layer 131 may have a single-layer or multi-layer structure. In particular, the plastic substrate has lower barrier properties than the glass substrate. Therefore, a multi-layer buffer layer 131 can be formed on the plastic substrate to ensure resistance to water and oxygen permeation. Furthermore, the buffer layer 131 may be omitted when there is almost no influence from external air or impurities such as water, or depending on the structure of the organic light-emitting display device 100.

[0053] A thin-film transistor 120, comprising a gate 121, an active layer 122, a source 123, and a drain 124, is disposed on a buffer layer 131. The thin-film transistor 120 may be disposed in each of a plurality of sub-pixel regions. For ease of description, Figure 2 Only the driving thin-film transistor among various thin-film transistors that can be included in the organic light-emitting display device 100 is illustrated. However, switching thin-film transistors, capacitors, or the like may also be included in the organic light-emitting display device 100. Furthermore, Figure 2 The diagram illustrates a thin-film transistor 120 with an interleaved structure, but a thin-film transistor with a coplanar structure can also be used.

[0054] An active layer 122 is formed on the first substrate 110, and a gate insulating layer 132 for insulating the active layer 122 from the gate 121 is formed on the active layer 122. Furthermore, an interlayer insulating layer 133 is formed for insulating the gate 121 from the source 123 and the drain 124. The source 123 and the drain 124, respectively in contact with the active layer 122, are formed on the interlayer insulating layer 133.

[0055] A planarization layer 134 is formed on the thin-film transistor 120. The planarization layer 134 is used to planarize the upper part of the thin-film transistor 120. The planarization layer 134 includes contact holes for electrically connecting the thin-film transistor 120 and the anode 141 of the white OLED 140. The planarization layer 134 may have a single-layer structure or a multi-layer structure and may be made of an organic insulating material. For example, the planarization layer 134 may be made of an acrylic resin, but is not limited thereto.

[0056] A passivation layer may be selectively formed on the planarization layer 134 if necessary. The passivation layer may be made of an inorganic insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx). Furthermore, the passivation layer may have a single-layer structure or a multi-layer structure, but is not limited thereto.

[0057] A white OLED 140 is disposed on a planarization layer 134. The white OLED 140 is electrically connected to a thin-film transistor 120 and includes an anode 141, a white organic light-emitting layer 142, and a cathode 143. The white OLED 140 is driven to display an image in the white organic light-emitting layer 142 by recombination between holes from the anode 141 and electrons from the cathode 143.

[0058] An anode 141 is disposed on the planarization layer 134. The anode 141 may be made of a material with a high work function to supply holes to the white organic light-emitting layer 142. For example, the anode 141 may be made of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), or indium tin zinc oxide (ITZO), but is not limited thereto. If the organic light-emitting display device 100 is a top-emitting type, the anode 141 may further include a reflective layer.

[0059] Anode 141 is electrically connected to thin-film transistor 120 through contact holes in planarization layer 134. For example, Figure 2The diagram illustrates that the anode 141 is electrically connected to the source 123 of the thin-film transistor 120, but the anode 141 can also be electrically connected to the drain 124. The anode 141 can be disposed in each sub-pixel SP. Furthermore, the anode 141 is formed in the emitter region EA of each sub-pixel SP. Even if the anode 141 is made of a transparent conductive material, the transmittance of the transmittance region TA will decrease when the anode 141 overlaps with the transmittance region TA. Therefore, the anode 141 can be formed only in the emitter region EA, and not in the transmittance region TA, but is not limited to this.

[0060] A cathode 143 is disposed on a white organic light-emitting layer 142. The cathode 143 is used to supply electrons to the white organic light-emitting layer 142. For example, the cathode 143 may be made of a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), zinc oxide (ZnO), and tin oxide (TO), or ytterbium (Yb) alloys, but is not limited thereto. As another example, the cathode 143 may be made of a metallic material including calcium (Ca), barium (Ba), aluminum (Al), silver (Ag), or similar materials. If the cathode 143 is made of a metallic material, it can be formed to have a very small thickness and therefore be substantially transparent. Furthermore, the cathode 143 is not patterned and can be formed as a single layer on the white organic light-emitting layer 142. That is, the cathode 143 is not separately disposed in each of the plurality of sub-pixels SP and can be formed as a single layer.

[0061] A white organic light-emitting layer 142 is disposed between an anode 141 and a cathode 143. The white organic light-emitting layer 142 is configured to emit white light. The white organic light-emitting layer 142 can be configured as a single light-emitting layer to emit white light. Alternatively, the white organic light-emitting layer 142 can have a stacked structure in which multiple light-emitting layers emitting different colors of light are laminated with an intermediate charge-generating layer to emit white light. For example, the color of light emitted from a first light-emitting layer can be complementary to the color of light emitted from a second light-emitting layer. Therefore, the light emitted from the first light-emitting layer and the light emitted from the second light-emitting layer can be mixed to ultimately emit white light. In addition to the white organic light-emitting layer 142, the white OLED 140 may further include at least one organic layer selected from a hole transport layer, an electron transport layer, a hole blocking layer, an electron blocking layer, a hole injection layer, and an electron injection layer. Such an organic layer enables the easy transport or injection of electrons or holes into the white organic light-emitting layer 142 and adjusts the charge balance between electrons and holes. Therefore, the luminous efficiency of the white organic light-emitting layer 142 can be further improved.

[0062] The white organic light-emitting layer 142 is not separately disposed in each sub-pixel, but can be a common layer formed in multiple sub-pixels SP. That is, as Figure 2As shown, the white organic light-emitting layer 142 can be formed as a single layer on the planarization layer 134 and the anode 141. The white organic light-emitting layer 142, which serves as a common layer among multiple sub-pixels SP, can be formed using an open mask. If the white organic light-emitting layer 142 is formed using an open mask, problems such as color mixing caused by mask overlap or misalignment that may occur when depositing patterns using a fine metal mask can be solved. Therefore, the white organic light-emitting layer 142 has excellent color coordinates, etc.

[0063] A dam layer 135 is formed on the anode 141 and the planarization layer 134. The dam layer 135 is used to divide adjacent sub-pixels SP, and additionally to divide the emission region EA and transmission region TA within a sub-pixel SP. Therefore, the dam layer 135 is disposed between adjacent sub-pixels SP and between the emission region EA and transmission region TA within a sub-pixel SP. Furthermore, the dam layer 135 may be formed as part of an open anode 141. The dam layer 135 may be made of an organic insulating material. For example, the dam layer 135 may be made of one or more materials selected from polyimide, photoacrylic, and benzocyclobutene (BCB). The dam layer 135 may be formed in a tapered shape.

[0064] at the same time, Figure 2 The diagram illustrates the formation of a white organic light-emitting layer 142 and a cathode 143 constituting a white OLED 140 on the entire surface of the embankment layer 135 and the planarization layer 134. Although not shown in the diagram, the white organic light-emitting layer and the cathode may be formed only in the emission region EA of each sub-pixel SP.

[0065] An encapsulation layer 150 is disposed on a white OLED 140. The encapsulation layer 150 inhibits the degradation of the white OLED 140 caused by the penetration of impurities such as water from the outside and flattens the upper portion of the white OLED 140. The encapsulation layer 150 may be made of an inorganic insulating material. Figure 2 The diagram illustrates a single-layer encapsulation layer 150, but the encapsulation layer 150 may be formed into a multi-layer structure if necessary. For example, the encapsulation layer may include a first inorganic encapsulation layer, an organic encapsulation layer, and a second inorganic encapsulation layer.

[0066] For example, the first inorganic encapsulation layer and the second inorganic encapsulation layer may be made independently of one or more materials selected from silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride (SiON), or aluminum oxide (Al2O3), but are not limited thereto.

[0067] For example, the organic encapsulation layer may be made of one or more materials selected from, but not limited to, polyimide, polystyrene resin, acrylic resin, epoxy resin, urea resin, isocyanate resin, xylene resin, and silicon oxycarbon (SiOC).

[0068] A filler portion 160 is formed on the encapsulation layer 150. The filler portion fills the gap between the encapsulation layer 150 and the second substrate 170.

[0069] When the first substrate 110 is bonded to the second substrate 170, if the space between the first substrate 110 and the second substrate 170 is not filled with a separate material, the organic light-emitting display device 100 may be relatively susceptible to the permeation of water and oxygen from the outside. Therefore, a filling portion 160 is formed in the space between the first substrate 110 and the second substrate 170 to suppress the permeation of water and oxygen.

[0070] For example, the filler 160 includes a matrix resin and a getter.

[0071] The matrix resin is a resin composition made of binder compounds and used to disperse the getter. The matrix resin itself can block water. Furthermore, the matrix resin can be a transparent binder resin that can bond the encapsulation layer 150 to the second substrate 170. The getter can more effectively suppress the permeation of water or oxygen from outside the organic light-emitting display device 100 by adsorbing water or blocking the permeation and advance path of water and oxygen. The matrix resin and getter constituting the filler portion 160 will be described in detail below.

[0072] A second substrate 170 is disposed on the filling portion 160. The second substrate 170 is disposed facing the first substrate 110. The second substrate 170 is used to support various components of the organic light-emitting display device 100. A color filter is formed on the second substrate 170. The second substrate 170 may be a color filter substrate on which a color filter layer 171 for realizing the color and black matrix 172 of the organic light-emitting display device 100 is formed.

[0073] A black matrix 172 is formed on the lower surface of the second substrate 170. The black matrix 172 is formed at the boundaries between sub-pixels SP and at the boundaries between the emitting region EA and the transmissive region TA within a sub-pixel SP. The black matrix 172 is used to delineate the light-emitting regions passing through the color filter layer 171, ensuring that the light passing through each color filter does not overlap or mix with each other. For example, the black matrix 172 can be formed as a non-transparent metal film such as chromium (Cr), or it can be formed as a pigment and resin comprising black pigment or multiple colors.

[0074] A color filter layer 171 is formed on the lower surface of the second substrate 170. For each sub-pixel SP, the color filter layer 171 may be formed on the second substrate 170. Specifically, the color filter layer 171 may include a red color filter, a green color filter, and a blue color filter patterned respectively corresponding to the colors of the plurality of sub-pixels SP. According to one embodiment of this disclosure, white light is emitted from the white OLED 140, and therefore, a color image can be represented by the color filter layer 171 patterned for each sub-pixel SP.

[0075] A dam structure 180 is formed between a first substrate 110 and a second substrate 170 in the non-display area NDA. The dam structure 180 is configured to surround the filler portion 160. The dam structure 180 is configured to contact both the first substrate 110 and the second substrate 170. The dam structure 180 bonds the first substrate 110 to the second substrate 170 to enhance the adhesive strength of the filler portion 160. The dam structure 180 can block the penetration of water and oxygen through the side surfaces of the organic light-emitting display device 100. The dam structure 180 acts as an element for sealing the components between the first substrate 110 and the second substrate 170, and can therefore be referred to as a sealant.

[0076] Figure 3 This is a schematic diagram provided to explain the configuration of the dam structure of an organic light-emitting display device according to an exemplary embodiment of the present disclosure.

[0077] Reference Figure 3 The dam structure 180 includes a matrix resin 181 and a getter 182.

[0078] Getter 182 can be surface-modified magnesium oxide particles.

[0079] Porous silica or metal-organic frameworks, typically used as getters, are physically bound to water, but physically adsorbed water can easily desorb depending on the external environment. Meanwhile, magnesium oxide particles chemically react with water, making desorption less likely. Therefore, magnesium oxide particles exhibit excellent water absorption properties and maintain high resistance to water permeation for a considerable period. Furthermore, calcium oxide, commonly used as a getter, consists of colored particles, thus reducing transparency. If calcium oxide adsorbs excessive water, it can easily degrade. Magnesium oxide particles, while possessing excellent water absorption properties, suffer from reduced transparency. Therefore, nano-sized magnesium oxide particles are used to improve transmittance while maintaining high water absorption. However, it is difficult to uniformly disperse these nano-sized particles in the matrix resin due to particle agglomeration. If particle agglomeration occurs, the size of the getter dispersed in the matrix resin increases from the nanoscale to the microscale, resulting in increased haze. Therefore, there are limitations in improving transmittance.

[0080] According to this disclosure, surface-modified magnesium oxide particles are used as getter 182. Therefore, transparency is greatly improved, and water absorption properties are also enhanced.

[0081] First, the magnesium oxide particles can have an average diameter ranging from 10 nm to 300 nm or from 10 nm to 100 nm. If the average diameter of the magnesium oxide particles is within the range described above, the transparency can be improved, and the amount of water adsorbed can be increased.

[0082] The surface of the magnesium oxide particles is modified into a first surface modification part and a second surface modification part.

[0083] The first surface-modified portion is formed by modifying the surface of magnesium oxide particles with an aminosilyl compound. That is, the first surface-modified portion is made of an aminosilyl compound. For example, the aminosilyl compound may include at least one selected from 3-(trimethoxysilylpropyl)diethylenetriamine, (3-aminopropyl)trimethoxysilane, 1-(3-(trimethoxysilyl)propyl)urea, (3-aminopropyl)triethoxysilane, 3-aminopropyl-methyl-diethoxysilane, N-3-(trimethoxysilyl)propylethylenediamine, and N-(3-(dimethoxymethylsilyl)propylethylenediamine).

[0084] Specifically, magnesium oxide particles are added to a mixture of alcohol and distilled water, and an acid is added to form hydroxyl groups on the surface of the magnesium oxide particles. If an aminosilyl compound is added, the hydroxyl groups react with the aminosilyl compound. Therefore, the surface of the magnesium oxide particles is modified with an aminosilyl compound.

[0085] For example, 3-(trimethoxysilylpropyl)diethylenetriamine is used as an aminosilyl compound. When the surface of magnesium oxide particles is modified using this compound, a product represented by the following general formula 1 can be obtained.

[0086] [General Formula 1]

[0087]

[0088] Aminosilyl compounds have an alkoxysilyl group and an amino group in their molecules. As shown in general formula 1, the alkoxysilyl group reacts with the hydroxyl group on the surface of magnesium oxide particles to form a bond. Therefore, an amino group is introduced into the surface of magnesium oxide particles modified with an aminosilyl compound. Specifically, a primary amino group (-NH2) is introduced into the surface of magnesium oxide particles modified with an aminosilyl compound.

[0089] Amino groups can form hydrogen bonds with water, thus inhibiting the advance of water. Therefore, in addition to the water-repellent properties of magnesium oxide, the first surface modification can also inhibit the advance of water, thus providing even greater resistance to water penetration.

[0090] Referring to general formula 1, if 3-(trimethoxysilylpropyl)diethylenetriamine is used as the aminosilyl compound, the surface-modified magnesium oxide has a primary amino group at the end of the first surface-modified portion. Furthermore, the surface-modified magnesium oxide has two secondary amino groups (-NH-) in the middle of the first surface-modified portion. Therefore, water propagation can be further inhibited, thus providing high resistance to water penetration.

[0091] The second surface-modified portion is bonded to the first surface-modified portion. The second surface-modified portion may be made of a compound comprising acrylate groups and methacrylate groups. For example, the compound comprising acrylate groups and methacrylate groups may be 3-(acryloyloxy)-2-hydroxypropyl methacrylate represented by the following chemical formula 1.

[0092] [Chemical Formula 1]

[0093]

[0094] As shown in Formula 1, 3-(acryloyloxy)-2-hydroxypropyl methacrylate has an acrylate group at one end and a methacrylate group at the other end.

[0095] As described above, the magnesium oxide particles are surface-treated with an aminosilyl compound, thereby introducing amino groups onto the surface of the magnesium oxide particles. Amino groups can undergo a Michael addition reaction with acrylate groups, but not with methacrylate groups. Therefore, the second surface-modified portion can be bonded to the first surface-modified portion via a Michael addition reaction between the amino and acrylate groups of the first surface-modified portion.

[0096] If a Michael addition reaction occurs between 3-(acryloyloxy)-2-hydroxypropyl methacrylate and magnesium oxide particles whose surfaces are modified into a first surface modification portion and represented by general formula 1, magnesium oxide particles whose surfaces are modified into a first surface modification portion and a second surface modification portion and represented by the following general formula 2 can be obtained.

[0097] [General Formula 2]

[0098]

[0099] For ease of description, general formula 2 illustrates the formation of a bond through a Michael addition reaction between the amino group at the end of the first surface-modified portion and 3-(acryloyloxy)-2-hydroxypropyl methacrylate. However, the amino group at the middle of the chain of the first surface-modified portion can also undergo a Michael addition reaction. That is, if 3-(trimethoxysilylpropyl)diethylenetriamine is used as a surface modifier to form the first surface-modified portion, each of the plurality of amino groups included in the molecule can undergo a Michael addition reaction with 3-(acryloyloxy)-2-hydroxypropyl methacrylate.

[0100] Specifically, referring again to general formula 1, each of the primary amino group (-NH2) at the end of the first surface-modified portion and the secondary amino group (-NH-) in the middle of the first surface-modified portion, introduced by surface modification with 3-(trimethoxysilylpropyl)diethylenetriamine, can undergo a Michael addition reaction with the acrylate group of 3-(acryloyloxy)-2-hydroxypropyl methacrylate. Therefore, surface-modified magnesium oxide particles represented by the following general formula 3 can be obtained.

[0101] [Formula 3]

[0102]

[0103] As shown in Formula 3, if a surface-modified portion in the form of a basin is formed on the surface of magnesium oxide particles, the advance of water introduced from the outside or desorbed from the magnesium oxide particles can be suppressed. Therefore, resistance to water penetration can be further improved.

[0104] Furthermore, referring to general formula 3, a secondary amino group (-NH-) formed from the Michael addition reaction between a primary amino group (-NH2) and 3-(acryloyloxy)-2-hydroxypropyl methacrylate can also undergo a Michael addition reaction with 3-(acryloyloxy)-2-hydroxypropyl methacrylate. The resulting product can be represented by the following general formula 3'.

[0105] [General Formula 3']

[0106]

[0107] As shown in Formulas 2 and 3, methacrylate groups are introduced onto the surface of magnesium oxide particles whose surface has been modified into a second surface-modified portion.

[0108] The matrix resin 181 is a resin composition made of a binder compound and is used to disperse the getter 182. The matrix resin 181 itself is water-resistant. Preferably, the matrix resin 181 may have high transparency to ensure the optical properties of the organic light-emitting display device 100. Furthermore, the dam structure 180 bonds the first substrate 110 to the second substrate 170. Therefore, the matrix resin can be a transparent binder resin.

[0109] The matrix resin 181 can be formed by the polymerization of an adhesive compound. For example, the adhesive compound constituting the matrix resin can be an acrylic monomer or oligomer containing at least two (meth)acrylate groups. The acrylic monomer or oligomer is cured to form an acrylic resin. For example, the adhesive compound can be bisphenol A glycerol di(meth)acrylate. This adhesive compound is preferred because it is transparent and includes hydroxyl groups that impart intramolecular adhesion. However, this disclosure is not limited thereto. Any transparent (meth)acrylate monomer and / or oligomer material with adhesive properties known in the art can be used.

[0110] The (meth)acrylate groups of the adhesive compound can be chemically bonded to the methacrylate groups of the second surface-modified portion. Therefore, when the matrix resin 181 is formed, the matrix resin 181 and the getter 182 can be chemically bonded to each other through a reaction between the methacrylate groups of the second surface-modified portion of the surface-modified getter 182 and the (meth)acrylate groups of the adhesive compound. As a result, the matrix resin 181 is chemically bonded to the getter 182, and thus, the high resistance to water permeation of the dam structure 180 can be maintained and its optical properties greatly improved.

[0111] Generally, increasing the amount of getter dispersed in the matrix resin improves water absorption but reduces transmittance. Furthermore, if nano-sized getters are used, it becomes difficult to uniformly disperse them in the matrix resin due to particle agglomeration, and the getter size increases from the nanometer to the micrometer level. Therefore, the haze value increases. Accordingly, there are limitations in improving transmittance. Furthermore, nano-sized getters have a large specific surface area, and therefore, the getter particles can degrade due to rapid water absorption. Consequently, resistance to water penetration lasts for a shorter period.

[0112] According to this disclosure, magnesium oxide particles with surfaces modified into first and second surface-modified portions are used as getter 182. Here, the first and second surface-modified portions, made of different compounds, are chemically bonded to each other. That is, the surface of the magnesium oxide particles is modified to form surface-modified portions in the long chains, thereby increasing the hydrophobic properties of getter 182. Therefore, the compatibility between getter 182 and matrix resin 181 is greatly increased. Furthermore, when matrix resin 181 is formed, matrix resin 181 and getter 182 are chemically bonded to each other through a reaction between the methacrylate groups of the second surface-modified portion and the (meth)acrylate groups of the binder compound. Therefore, even when the amount of getter 182 is increased, the transmittance of the dam structure 180 does not decrease significantly, and the water absorption properties are further improved.

[0113] For example, the getter 182 can be included in proportions ranging from 0.5 wt% to 20 wt%, from 1 wt% to 10 wt%, or from 3 wt% to 7 wt% based on the total weight of the matrix resin 181 and the getter 182. Within this range, the dam structure 180 exhibits high light transmittance and low haze values, and therefore excellent transparency and excellent resistance to water penetration. If the getter 182 is included in proportions less than 0.5 wt%, the water absorption properties are too low, and therefore the waterproof properties of the dam structure 180 may be reduced. If the getter 182 is included in proportions greater than 20 wt%, the haze value increases, and therefore the transmittance may decrease.

[0114] Furthermore, the first surface-modified portion has at least one amino group, and the second surface-modified portion has a hydroxyl group. These functional groups can interact with water. That is, these functional groups can bind to water introduced from the outside or water desorbed from magnesium oxide particles, which inhibits or delays the propagation of water toward the OLED 140.

[0115] Therefore, the transparency of the entire organic light-emitting display device can be increased, and thus the optical properties can be improved. Furthermore, resistance to water penetration can be increased, and therefore, display quality and durability can be improved.

[0116] The dam structure 180 may further include additives without reducing optical properties or adhesion strength. Additives can be used to compensate for the shape and properties of the dam structure 180. For example, spacers and / or fillers can be used as additives.

[0117] The spacer maintains the height of the dam structure 180 to maintain the gap between the first substrate 110 and the second substrate 170. In addition, the spacer blocks the seepage path of water introduced from the outside.

[0118] The spacer can be made of an elastic material. Therefore, the gap between the first substrate 110 and the second substrate 170 can be easily adjusted. Furthermore, the elastic spacer can more stably bond the first substrate 110 to the second substrate 170. More specifically, when the first substrate 110 is bonded to the second substrate 170, by applying a predetermined stress, they undergo elastic deformation and are stably bonded to each other. When the stress is reduced or eliminated, the elastic deformation is restored, and thus, the gap between the substrates can be maintained more uniformly.

[0119] The filler material can be used to increase the movement path of water that permeates through the side surface of the organic light-emitting display device 100, thereby inhibiting water infiltration. Furthermore, the filler material can have waterproof properties. Therefore, the dam structure's resistance to water infiltration can be further improved. For example, the filler material can be selected from at least one of, but is not limited to, clay, talc, silicon dioxide, barium sulfate, aluminum hydroxide, calcium carbonate, magnesium carbonate, zeolite, zirconium oxide, titanium dioxide, montmorillonite, aluminum oxide, aluminum nitride, cerium oxide, hafnium oxide, niobium pentoxide, tantalum pentoxide, indium oxide, tin oxide, indium tin oxide, zinc oxide, zinc sulfide, and silicon nitride.

[0120] The packing material can be sheet-like. Sheet-like packing has a larger aspect ratio than spherical packing, thus resulting in a longer and more complex water movement path. Therefore, sheet-like packing can further improve the dam structure's resistance to water seepage. However, this disclosure is not limited thereto. Various packing materials, such as spherical packing, elliptical packing, and amorphous packing, can be used.

[0121] The filler can be surface-treated with a silane coupling agent to facilitate its dispersion in the matrix resin 181.

[0122] As described above, the filler portion 160 of this disclosure includes a matrix resin and a getter. The matrix resin and getter constituting the filler portion 160 may be the same as the matrix resin 181 and getter 182 constituting the dam structure 180. In this case, the water permeability resistance and transmittance of the organic light-emitting display device 100 can be further improved. Therefore, a display device with excellent reliability and durability as well as superior optical properties can be provided.

[0123] Furthermore, the filling section 160 may further include filler material, and the filler material may be the same as that included in the dam structure 180.

[0124] In exemplary embodiments of this disclosure, magnesium oxide particles modified into a first surface modification portion and a second surface modification portion have been described as being used as getters in each of the dam structure 180 and the filler portion 160. However, this disclosure is not limited thereto. The magnesium oxide particles modified into the first surface modification portion and the second surface modification portion may be applied only to either the dam structure or the filler portion.

[0125] The effects of this disclosure will be described in more detail below with reference to the following embodiments. However, the following embodiments are provided merely to illustrate examples of this disclosure and do not limit the scope of this disclosure.

[0126] [Preparation Implementation Method 1]

[0127] A precursor solution was prepared by dissolving 0.51 g of magnesium nitrate hexahydrate (Mg(NO3)2·6H2O) in 10 ml of distilled water and stirring. After dissolving 0.84 g of polyethylene glycol and 0.25 g of sodium hydroxide in 20 ml of distilled water, the resulting product was added to the precursor solution, and the mixture was stirred at room temperature for 1 hour to synthesize magnesium oxide nanoparticles. The product was centrifuged to separate the precipitate. The separated precipitate was then placed in ethanol, followed by centrifugation and purification. The purified product was then dried at 60 °C for 5 hours and calcined at 400 °C for 1 hour to obtain magnesium oxide nanoparticle powder.

[0128] [Preparation Implementation Method 2]

[0129] 1. First surface modification

[0130] The solvent was prepared by adjusting the pH to 4 by adding 0.02 ml of hydrochloric acid to a mixed solution of 10 ml of ethanol and distilled water. Then, 0.2 g of magnesium oxide nanoparticle powder prepared in Example 1 and 2 g of 3-(trimethoxysilylpropyl)diethylenetriamine (TPDT) as the first surface modifier were added to the solvent, and the mixture was reacted in a silicone oil tank at 80°C in boiling water for 6 hours while stirring.

[0131]

[0132] 2. Second surface modification

[0133] Then, 16 g of 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AHM) as a second surface modifier was added to the reaction bath and reacted for 12 hours with continuous stirring. Afterward, the product was centrifuged to separate the precipitate. The precipitate was then placed in ethanol, followed by centrifugation and purification. The product was then dried at 50°C for 3 hours, thereby obtaining magnesium oxide nanoparticles with surface modified by TPDT and AHM.

[0134]

[0135] [Preparation Implementation Method 3]

[0136] The preparation involved adjusting the pH of a solvent to 4 by adding 0.02 ml of hydrochloric acid to a mixture of 10 ml of ethanol and distilled water. Then, 0.2 g of magnesium oxide nanoparticle powder (similar to preparation method 1) and 4 g of 3-methacryloyloxypropyltrimethoxysilane (MPS) as a surface modifier were added to this solvent, and the mixture was reacted in a silicone oil tank at 80°C in boiling water for 12 hours. The product was centrifuged to separate the precipitate. The precipitate was then placed in ethanol, followed by centrifugation and purification. Afterward, the product was dried at 50°C for 3 hours, thereby obtaining magnesium oxide nanoparticles with MPS surface modification.

[0137]

[0138] [Experimental Implementation Method 1]

[0139] The crystallinity and adsorption properties of the magnesium oxide nanoparticles prepared according to Example 1, as well as the surface-modified magnesium oxide nanoparticles prepared according to Examples 2 and 3, were measured. Crystallinity was measured using X-ray diffraction analysis, and the results are shown below. Figures 4A to 4C As shown in the figure. Furthermore, the adsorption capacity was measured using a dynamic vapor adsorption apparatus by analyzing the change in sample weight while simultaneously increasing the relative humidity from 0% to 90% at 25°C to achieve saturation. The measurement results are as follows. Figures 5A to 5C As shown in the image.

[0140] first, Figure 4A The image shows the X-ray diffraction pattern of the magnesium oxide nanoparticles prepared according to Embodiment 1. Figure 4B The X-ray diffraction pattern is that of the surface-modified magnesium oxide nanoparticles prepared according to Embodiment 2. Figure 4C The X-ray diffraction pattern is that of the surface-modified magnesium oxide nanoparticles prepared according to Embodiment 3.

[0141] Reference Figures 4A to 4CAs can be seen, only a magnesium oxide (MgO) peak was observed for the magnesium oxide nanoparticles prepared in Example 1, but a weak Mg(OH)2 peak was observed for the surface-modified magnesium oxide nanoparticles prepared in Examples 2 and 3. Therefore, it can be seen that the magnesium oxide nanoparticles prepared in Examples 2 and 3 are surface-modified particles.

[0142] Figures 5A to 5C These are graphs showing the changes in weight of magnesium oxide nanoparticles prepared according to Embodiment 1 to Embodiment 3 as a function of relative humidity.

[0143] Reference Figures 5A to 5C As can be seen, the surface-modified magnesium oxide nanoparticles prepared in Embodiment 2 and Embodiment 3 exhibit similar adsorption behavior. However, it can be seen that, compared with the surface-modified magnesium oxide nanoparticles of Embodiment 3, which are surface-modified with MPS, the surface-modified magnesium oxide nanoparticles of Embodiment 2, which are surface-modified with TPDT and AHM and have long chains in the surface-modified portion, exhibit a higher maximum water absorption.

[0144] [Implementation Method 1A]

[0145] A dam-forming composition was prepared using surface-modified magnesium oxide nanoparticles prepared in Example 2 as a getter. Specifically, 0.01 g of surface-modified magnesium oxide nanoparticles prepared in Example 2 were dispersed in 0.99 g of an adhesive resin (bisphenol A glycerol dimethacrylate oligomer) containing 1 wt% photoinitiator to prepare a dam-forming composition (1 wt% getter).

[0146] [Implementation Method 1B]

[0147] The dam-forming composition was prepared in the same manner as in Embodiment 1A, except that the amounts of the surface-modified magnesium oxide nanoparticles and the binder resin prepared in Embodiment 2 were changed to 0.02 g and 0.98 g, respectively.

[0148] [Implementation Method 1C]

[0149] The dam-forming composition was prepared in the same manner as in Embodiment 1A, except that the amounts of the surface-modified magnesium oxide nanoparticles and the binder resin prepared in Embodiment 2 were changed to 0.03 g and 0.97 g, respectively.

[0150] [Implementation Method 1D]

[0151] The dam-forming composition was prepared in the same manner as in Embodiment 1A, except that the amounts of the surface-modified magnesium oxide nanoparticles and the binder resin prepared in Embodiment 2 were changed to 0.05 g and 0.95 g, respectively.

[0152] [Comparative Implementation Method 1A]

[0153] The dam-forming composition was prepared in the same manner as in Embodiment 1A, except that the surface-unmodified magnesium oxide nanoparticles of Embodiment 1 were used instead of the surface-modified magnesium oxide nanoparticles of Embodiment 2.

[0154] [Comparative Implementation Method 1B]

[0155] The dam-forming composition was prepared in the same manner as in Embodiment 1B, except that the surface-unmodified magnesium oxide nanoparticles of Embodiment 1 were used instead of the surface-modified magnesium oxide nanoparticles of Embodiment 2.

[0156] [Comparative Implementation Method 1C]

[0157] The dam-forming composition was prepared in the same manner as in Embodiment 1C, except that the surface-unmodified magnesium oxide nanoparticles of Embodiment 1 were used instead of the surface-modified magnesium oxide nanoparticles of Embodiment 2.

[0158] [Comparative Implementation Method 1D]

[0159] The dam-forming composition was prepared in the same manner as in Embodiment 1D, except that the surface-unmodified magnesium oxide nanoparticles of Embodiment 1 were used instead of the surface-modified magnesium oxide nanoparticles of Embodiment 2.

[0160] [Comparative Implementation Method 2A]

[0161] The dam-forming composition was prepared in the same manner as in Embodiment 1A, except that the surface-modified magnesium oxide nanoparticles prepared in Embodiment 3 were used instead of the surface-modified magnesium oxide nanoparticles prepared in Embodiment 2.

[0162] [Comparative Implementation Method 2B]

[0163] The dam-forming composition was prepared in the same manner as in Embodiment 1B, except that the surface-modified magnesium oxide nanoparticles prepared in Embodiment 3 were used instead of the surface-modified magnesium oxide nanoparticles prepared in Embodiment 2.

[0164] [Comparative Implementation Method 2C]

[0165] The dam-forming composition was prepared in the same manner as in Embodiment 1C, except that the surface-modified magnesium oxide nanoparticles prepared in Embodiment 3 were used instead of the surface-modified magnesium oxide nanoparticles prepared in Embodiment 2.

[0166] [Comparative Implementation Method 2D]

[0167] The dam-forming composition was prepared in the same manner as in Embodiment 1D, except that the surface-modified magnesium oxide nanoparticles prepared in Embodiment 3 were used instead of the surface-modified magnesium oxide nanoparticles prepared in Embodiment 2.

[0168] [Comparative Implementation Method 3]

[0169] The dam-forming composition was prepared in the same manner as in Embodiment 1D, except that unmodified calcium oxide nanoparticles were used instead of the surface-modified magnesium oxide nanoparticles prepared in Embodiment 2.

[0170] [Experimental Implementation Method 2]

[0171] The transmittance and haze of dam structures made from the dam-forming compositions of Embodiments 1A to 1D, Comparative Embodiments 1A to 1D, and Comparative Embodiments 2A to 2D were measured. To measure transmittance and haze, the dam-forming composition was applied to a glass substrate using a rod coating method, and then passed through a UV lamp at 70 mJ / cm². 2 Curing was performed using UV irradiation to fabricate a film sample with a thickness of 10 μm. Transmittance and haze were measured at a wavelength of 550 nm using a UV-Vis spectrometer. The measurement results are shown in Table 1 and... Figures 6A to 6D As shown in the image.

[0172] Figure 6A It is a graph showing the transmittance of the dam structure according to Embodiment 1A, Comparative Embodiment 1A, and Comparative Embodiment 2A in the visible wavelength range. Figure 6B It is a graph showing the transmittance of the dam structure according to Embodiment 1B, Comparative Embodiment 1B, and Comparative Embodiment 2B in the visible wavelength range. Figure 6C It is a graph showing the transmittance of the dam structure according to Embodiment 1C, Comparative Embodiment 1C, and Comparative Embodiment 2C in the visible wavelength range. Figure 6D It is a graph showing the transmittance of the dam structure according to Embodiment 1D, Comparative Embodiment 1D, and Comparative Embodiment 2D in the visible wavelength range.

[0173] [Table 1]

[0174]

[0175] Refer to Table 1 and Figures 6A to 6DAs can be seen, with the same amount of getter, compared with Comparative Embodiments 1A to 1D and Comparative Embodiments 2A to 2D, Embodiments 1A to 1D, in which magnesium oxide nanoparticles with surface modified with TPAP and AHM are used as getters, show higher transmittance and lower haze.

[0176] As can be seen, with the increase of the amount of getter, Comparative Embodiments 1A to 1D and Comparative Embodiments 2A to 2D show a significant decrease in transmittance and a significant increase in haze. If unmodified magnesium oxide nanoparticles are included, it can be seen that when the getter is included at 3% by weight as shown in Comparative Embodiment 1C, the transmittance decreases to less than 90%, and the haze increases to 5% or more. Furthermore, if magnesium oxide nanoparticles with MPS surface modification are included, it can be seen that when the getter is included at 5% by weight as shown in Comparative Embodiment 2D, the transmittance decreases to less than 90%.

[0177] Unlike the above cases, if magnesium oxide nanoparticles with surface modified with TPDT and AHM are included as shown in Embodiment 1D, it can be seen that even when a getter is included at 5% by weight, the transmittance is as high as 90% or greater, and the haze is as low as 3.5% or less. Therefore, the optical properties are excellent.

[0178] Referring to the results of Embodiment 1A, Comparative Embodiment 1A, and Comparative Embodiment 2A, compared with Comparative Embodiment 1A without surface modification, Embodiment 1A and Comparative Embodiment 2A with surface modification exhibit higher transmittance and lower haze. Therefore, it can be seen that the optical properties are excellent. This is a result of improved dispersion of the getter in the matrix resin due to the strong chemical bonds between the methacrylate groups of the getter introduced by the surface modifier and the acrylic matrix resin.

[0179] Meanwhile, comparing the results of Embodiment 1A and Comparative Embodiment 2A, it can be seen that when the getter is included at 1% by weight, the two samples are similar in terms of transmittance and haze. However, it can be seen that for the magnesium oxide nanoparticles with MPS-modified surfaces according to Comparative Embodiment 2, the optical properties decrease sharply with increasing amounts of getter. Unlike this, for the magnesium oxide nanoparticles with TPDT and AHM-modified surfaces according to Embodiment 1, the rate of decrease in optical properties is very small even with increasing amounts of getter. Therefore, even when the getter is included at 5% by weight, Embodiment 1 shows a transmittance of 92% or greater and a low haze of 3.5% or less. Therefore, it can be seen that the optical properties of Embodiment 1 are maintained at a high level.

[0180] [Experimental Implementation Method 3]

[0181] The maximum water absorption, resistance to water infiltration, transmittance, and fog density of dam structures made from the dam-forming compositions of Embodiment 1D, Comparative Embodiment 1D, Comparative Embodiment 2D, and Comparative Embodiment 3 were measured. The measurement results are shown in Table 2.

[0182] The maximum water absorption was measured using a dynamic steam adsorption device in the same manner as in Experiment 1 described above, and the transmittance and haze were measured in the same manner as in Experiment 2 described above.

[0183] like Figure 7 The samples shown were manufactured using the dam-forming compositions of Embodiment 1D, Comparative Embodiment 1D, Comparative Embodiment 2D, and Comparative Embodiment 3, and then their resistance to water permeation was measured. Specifically, refer to... Figure 7 Anhydrous cobalt chloride test paper 20 for testing water permeability is placed on the lower substrate 11, and a dam-forming composition is coated along the side surface of the lower substrate 11. After this, the upper substrate 12 is bonded to it, and then the dam-forming composition is passed through a UV lamp at 70 mJ / cm². 2 UV irradiation for 20 seconds is used for curing to form a dam structure 30 with a width of 5 mm. Ultimately, a structure like... Figure 7 The sample shown is an example. The prepared sample was placed in a thermo-humidifier set to 85°C and 85% relative humidity, and the color change of cobalt chloride test paper was observed with the naked eye. The resistance to water penetration was evaluated based on the time taken for the cobalt chloride test paper to change color.

[0184] [Table 2]

[0185]

[0186] Referring to Table 2 above, it can be seen that, compared with Embodiment 1D, Comparative Embodiment 3, which includes calcium oxide nanoparticles commonly used as getters, and Comparative Embodiment 1D, which includes unmodified magnesium oxide nanoparticles, exhibit significantly lower water absorption and optical properties.

[0187] Meanwhile, the compatibility of the magnesium oxide nanoparticles with MPS-modified surfaces according to Comparative Embodiment 2D with the matrix resin increases due to surface modification. Therefore, compared to Comparative Embodiment 1D and Comparative Embodiment 3, Comparative Embodiment 2D exhibits improved optical properties, but shows low maximum water absorption and low resistance to water penetration. Therefore, it can be seen that Comparative Embodiment 2D does not possess excellent waterproof properties.

[0188] In contrast, Embodiment 1D, which includes magnesium oxide nanoparticles modified with TPDT and AHM, exhibits high maximum water absorption and superior resistance to water penetration. Furthermore, Embodiment 1D demonstrates excellent optical properties. Therefore, it can be seen that if the getter according to the embodiment is included in the dam structure and / or filling portion, high transmittance of the organic light-emitting display device can be maintained and water penetration from the outside can be suppressed. Moreover, the water movement path can be made complex, thus delaying the advance of water towards the OLED. Therefore, the transparency of the organic light-emitting display device can be improved. Furthermore, the display quality, durability, and lifespan of the organic light-emitting display device can be improved.

[0189] Alternatively, the exemplary embodiments of this disclosure may be described below:

[0190] According to one aspect of this disclosure, an organic light-emitting display device includes: a first substrate, the first substrate including a plurality of sub-pixels and defining a display area and a non-display area surrounding the display area in the first substrate; a thin-film transistor disposed on the first substrate; an organic light-emitting diode disposed on the thin-film transistor; a second substrate facing the first substrate; a filling portion filling a gap between the second substrate and the organic light-emitting diode; and a dam structure disposed in the non-display area and surrounding the filling portion, wherein at least one of the dam structure and the filling portion includes a getter, and the getter is composed of magnesium oxide particles whose surface is modified to be made of an aminosilyl compound and a second surface modified portion bonded to the first surface modified portion and made of a compound including acrylate groups and methacrylate groups.

[0191] The magnesium oxide particles may have an average diameter ranging from 10 nm to 300 nm.

[0192] The aminosilyl compound may include at least one selected from 3-(trimethoxysilylpropyl)diethylenetriamine, (3-aminopropyl)trimethoxysilane, 1-(3-(trimethoxysilyl)propyl)urea, (3-aminopropyl)triethoxysilane, 3-aminopropyl-methyl-diethoxysilane, N-3-(trimethoxysilyl)propylethylenediamine, and N-(3-(dimethoxymethylsilyl)propylethylenediamine).

[0193] The compound comprising acrylate and methacrylate groups may be 3-(acryloyloxy)-2-hydroxypropyl methacrylate.

[0194] The amino group of the aminosilyl compound and the acrylate group of the compound comprising acrylate and methacrylate groups can be chemically bonded to each other via a Michael addition reaction.

[0195] At least one of the dam structure and the filling portion may include the getter and a matrix resin having functional groups to be bound to the getter.

[0196] The matrix resin may be an acrylic resin and the functional group to be bound to the getter may be a (meth)acrylate group.

[0197] The getter may be included in a proportion of 0.5% to 20% by weight based on the total weight of the matrix resin and the getter.

[0198] The dam structure may further include spacers and filler.

[0199] The filling portion may further include filler.

[0200] The first substrate may include a plurality of sub-pixels in the display area, and the organic light-emitting diode emits white light, and the organic light-emitting display device may further include a color filter disposed in a portion of the second substrate.

[0201] Each of the plurality of sub-pixels may include an emission region and a transmission region.

[0202] The organic light-emitting diode may include an anode disposed on the thin-film transistor, a white organic light-emitting layer disposed on the anode, and a cathode disposed on the white organic light-emitting layer, wherein the anode may overlap with the transmission region, and the white organic light-emitting layer may overlap with the emission region and the transmission region.

[0203] Although exemplary embodiments of this disclosure have been described in detail with reference to the accompanying drawings, this disclosure is not limited thereto and may be embodied in many different forms without departing from the technical concept of this disclosure. Therefore, the exemplary embodiments of this disclosure are provided for illustrative purposes only and are not intended to limit the technical concept of this disclosure. The scope of the technical concept of this disclosure is not limited thereto. Therefore, it should be understood that the above exemplary embodiments are illustrative in all respects and do not limit this disclosure. The scope of protection of this disclosure should be interpreted based on the following claims, and all technical concepts within the equivalent scope of this disclosure should be interpreted as falling within the scope of this disclosure.

Claims

1.An organic light emitting display device, comprising: a first substrate including a plurality of sub-pixels, and defining a display area and a non-display area surrounding the display area in the first substrate; a thin film transistor disposed on the first substrate; an organic light emitting diode disposed on the thin film transistor; a second substrate facing the first substrate; a filling portion filling a gap between the second substrate and the organic light emitting diode; and a dam structure disposed in the non-display area and surrounding the filling portion, wherein at least one of the dam structure and the filling portion includes a getter, and the getter is composed of magnesium oxide particles having a first surface modification portion modified by an amino silane-based compound and a second surface modification portion bonded to the first surface modification portion and made of a compound including an acrylate group and a methacrylate group. 2.The organic light emitting display device of claim 1, wherein the magnesium oxide particles have an average diameter of from 10 nm to 300 nm. 3.The organic light emitting display device of claim 1, wherein the amino silane-based compound includes at least one selected from 3-(trimethoxysilylpropyl)diethylenetriamine, (3-aminopropyl)trimethoxysilane, 1-(3-(trimethoxysilyl)propyl)urea, (3-aminopropyl)triethoxysilane, 3-aminopropyl-methyl-diethoxysilane, N-3-(trimethoxysilyl)propyl ethylene diamine, and N-(3-(dimethoxymethylsilyl)propyl ethylene diamine). 4.The organic light emitting display device of claim 1, wherein the compound including an acrylate group and a methacrylate group is 3-(acryloyloxy)-2-hydroxypropyl methacrylate. 5.The organic light emitting display device of claim 1, wherein an amino group of the amino silane-based compound and an acrylate group of the compound including an acrylate group and a methacrylate group are chemically bonded to each other by a Michael addition reaction. 6.The organic light emitting display device of claim 1, wherein at least one of the dam structure and the filling portion includes the getter and a matrix resin having a functional group to be bonded to the getter. 7.The organic light emitting display device of claim 6, wherein the matrix resin is an acrylic-based resin and the functional group to be bonded to the getter is a (meth)acrylate group. 8.The organic light emitting display device of claim 6, wherein the getter is included in a proportion of 0.5 wt% to 20 wt% based on the total weight of the matrix resin and the getter. 9.The organic light emitting display device of claim 1, wherein the dam structure further includes a spacer and a filler. 10.The organic light emitting display device of claim 1, wherein the filling portion further includes a filler. 11.The organic light emitting display device of claim 1, wherein the first substrate includes a plurality of sub-pixels in the display area, and the organic light emitting diode emits white light, and ​ The organic light emitting display device further includes a color filter disposed in a portion of the second substrate. 12.The organic light emitting display device of claim 11, wherein each of the plurality of sub-pixels comprises an emission area and a transmission area. 13.The organic light emitting display device of claim 12, wherein the organic light emitting diode comprises an anode disposed on the thin film transistor, a white organic light emitting layer disposed on the anode, and a cathode disposed on the white organic light emitting layer, and the anode overlaps the transmission area, and the white organic light emitting layer overlaps the emission area and the transmission area.

Images