Window and display device including same

Abstract

The invention relates to a window and a display device including the same. A window according to an embodiment includes a base substrate, a first coating layer on a first surface of the base substrate, and a second coating layer on a second surface of the base substrate overlapping the first surface, the base substrate includes a vertical surface orthogonal to the first surface and the second surface, and the first coating layer overlaps the vertical surface.

Description

Technical Field

[0001] The present disclosure relates to a window and a display device including the window. Background Art

[0002] Recently, people use a variety of mobile electronic devices using display devices including liquid crystal display devices (LCD) or organic light emitting display devices (OLED), such as mobile phones, navigation devices, digital cameras, electronic books, portable game consoles, or various terminal devices.

[0003] A typical display device used in such a mobile electronic device may be provided with a cover window (hereinafter referred to as a window), and the cover window is configured to be transparent so that a user can view the display portion in front of the display panel. Since the window is located at the outermost structure of the display device, it should have a strong ability to resist external impacts so as to protect the display panel and the like inside the display device.

[0004] In addition, unlike previous electronic devices that used switches or keyboards as input devices, structures that use touch panels integrated with display screens have recently become widely used instead, and compared to previous mobile devices, the surface of the window is more likely to come into contact with fingers, etc., thereby creating a demand for windows with higher strength. Summary of the invention

[0005] Technical issues solved

[0006] The embodiment provides a window having a small thickness, a light weight and excellent impact resistance, and a display device including the window.

[0007] Workaround

[0008] According to one embodiment, a window includes a base substrate, a first coating layer, and a second coating layer, wherein the first coating layer is located on a first surface of the base substrate, the second coating layer is located on a second surface of the base substrate overlapping the first surface, the base substrate includes a vertical surface orthogonal to the first surface and the second surface, and the first coating layer overlaps the vertical surface.

[0009] The base substrate may include a first inclined surface, wherein the first inclined surface is inclined with respect to the first surface, and the first inclined surface may connect the first surface and the vertical surface.

[0010] The first coating layer may overlap the first inclined surface.

[0011] An end of the first coating layer may be inclined with respect to the vertical surface of the base substrate.

[0012] The first coating layer may be in direct contact with the second coating layer.

[0013] The base substrate may include a second inclined surface, wherein the second inclined surface is inclined relative to the second surface, and the second inclined surface may connect the second surface and the vertical surface.

[0014] The second inclined surface may include a curved surface.

[0015] The second coating layer may overlap the second inclined surface.

[0016] The first coating layer may include METHYL T POLYDIMETHYLSILOXANE.

[0017] The first coating layer may further include at least one of octamethylcyclotetrasiloxane and dimethylsiloxane.

[0018] The first coating layer may further include melamine resin.

[0019] The first coating layer may have a thickness of 7 μm to 13 μm.

[0020] The base substrate and the first coating layer may be connected in a covalently bonded manner.

[0021] According to one embodiment, a window includes a base substrate and a first coating layer, wherein the base substrate includes a first surface and a second surface overlapping each other, the first coating layer is located on the first surface of the base substrate, the base substrate includes a vertical surface orthogonal to the first surface and the second surface, and the first coating layer overlaps the vertical surface.

[0022] The window may further include a second coating layer disposed on a second surface of the base substrate.

[0023] According to one embodiment, a display device includes a display panel and a window, wherein the window overlaps with the display panel, and the window includes a base substrate, a first coating layer, and a second coating layer, wherein the first coating layer is located on a first surface of the base substrate, the second coating layer is located on a second surface of the base substrate overlapping with the first surface, the base substrate includes a vertical surface orthogonal to the first surface and the second surface, and the first coating layer overlaps with the vertical surface.

[0024] The first surface of the base substrate may be a surface facing the display panel.

[0025] The display panel may have flexibility.

[0026] The base substrate may include a first inclined surface, wherein the first inclined surface is inclined relative to the first surface, the first inclined surface may connect the first surface and the vertical surface, and the first coating layer may overlap the first inclined surface.

[0027] The first surface of the base substrate may include grooves, and the first coating layer may fill the grooves.

[0028] The display device may further include an adhesive layer and a light shielding layer, the adhesive layer and the light shielding layer being located between the first coating layer and the display panel.

[0029] Beneficial Effects

[0030] According to the embodiment, the impact resistance of the window can be improved. In addition, even in the case of including a thin base substrate, sufficient impact resistance can be provided, so that the thickness and weight of the window itself can be reduced. The thickness and weight of a display device including such a window can be reduced. In addition, by reducing the thickness of the window and increasing the thickness of a battery included in the display device, a display device with excellent performance can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1a is a cross-sectional view of a display device including a window according to an embodiment.

[0032] Figure 1b is a cross-sectional view of a display device including a window according to an embodiment.

[0033] Figure 2 is a cross-sectional view of a display device including a window according to an embodiment.

[0034] Figure 3 is a cross-sectional view of a window according to an embodiment.

[0035] Figure 4 is a cross-sectional view of a window according to an embodiment.

[0036] Figure 5 is a cross-sectional view of a window according to an embodiment.

[0037] Figure 6 is a cross-sectional view of a window according to an embodiment.

[0038] Figure 7 is a view showing a manufacturing process of a window according to an embodiment.

[0039] Figure 8: is a graph showing the break energy according to the example and the comparative example.

[0040] Fig. 9 This is a graph showing the results of a falling ball test performed on Examples and Comparative Examples.

[0041] Fig.10 is a graph showing the destruction energy according to the thickness of the first coating layer.

[0042] Fig.11 : is a graph showing the destruction energy according to whether the plasma process is performed and the process order.

[0043] Fig.12 : is a graph showing the destruction energy according to the embodiment and the comparative example.

[0044] Fig.13 Yes Fig.12 A graph showing the results of the drop ball test performed on the comparative examples and embodiments.

[0045] Fig.14 This is a graph showing the results of testing the heights of bright spots in comparative examples and examples.

[0046] Fig.15 This is a graph showing the results of testing the impact resistance of comparative examples and examples.

[0047] Fig.16 The images are the results of the crack growth test on the comparative example and the embodiment.

[0048] Description of Reference Numerals

[0049] 300: Window

[0050] 310: Base material

[0051] 320: First coating layer

[0052] 330: Second coating layer DETAILED DESCRIPTION

[0053] Various embodiments of the present invention are described in detail below with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. The present invention can be implemented in various forms and is not limited to the embodiments described herein.

[0054] In order to clearly describe the present invention, parts not related to the description are omitted, and the same reference numerals are given to the same or similar components throughout the specification.

[0055] In addition, for the convenience of explanation, the size and thickness of each structure shown in the drawings are arbitrarily shown, so the present invention is not necessarily limited to what is shown in the drawings. In order to clearly show each layer and region, the thickness is enlarged in the drawings. In addition, for the convenience of explanation, the thickness of some layers and regions is exaggerated in the drawings.

[0056] Furthermore, when a layer, film, region, plate or the like is referred to as being "on" or "above" another part, it includes not only the case where it is "directly" "on" another part, but also the case where there are other parts in between. Conversely, when a part is referred to as being "directly" "on" another part, it means that there are no other parts in between. Furthermore, being "on" or "above" a reference part means being above or below the reference part, and does not necessarily mean being "on" or "above" in the direction opposite to gravity.

[0057] Furthermore, throughout the specification, when a part is referred to as “comprising” a certain constituent element, unless otherwise explicitly stated otherwise, it means that other constituent elements may also be included, rather than excluding other constituent elements.

[0058] Furthermore, throughout the specification, when referred to as “on a plane”, it means a case where the object portion is viewed from above, and when referred to as “on a cross section”, it means a case where a vertically cut cross section of the object portion is viewed from the side.

[0059] Refer to below Figure 1a A window according to an embodiment and a display device including the window are described. Figure 1a is a schematic cross-sectional view of a display device including a window according to an embodiment.

[0060] like Figure 1a As shown in FIG. 1 , a display device according to an embodiment includes a display panel 100 and a window 300 located on the display panel 100. An adhesive layer 220 is positioned between the display panel 100 and the window 300 to combine the display panel 100 and the window 300.

[0061] The display panel 100 may be flexible, stretchable, foldable, bendable, or rollable. The display panel 100 may have flexibility to bend, but is not limited thereto, and may also be a flat display panel 100 .

[0062] The display panel 100 may be an organic light emitting display panel and may include a substrate, a plurality of thin film transistors and a plurality of electrodes on the substrate.

[0063] Although the embodiment in which the display panel 100 is an organic light emitting display panel is described, the present invention is not limited thereto. According to other embodiments, the display panel 100 may be a liquid crystal display panel, an electrophoretic display panel, an electrowetting display panel, etc.

[0064] The adhesive layer 220 is located between the display panel 100 and the window 300 , and combines the display panel 100 with the window 300 .

[0065] The adhesive layer 220 may be a transparent polymer resin layer, and as an example, may include at least one of an optical clear adhesive (OCA), an optical clear resin (OCR), a pressure sensitive adhesive (PSA), and a Super View Resin (SVR).

[0066] A light shielding layer 210 may be positioned between the adhesive layer 220 and the window 300. The light shielding layer 210 includes a material capable of blocking light. According to an embodiment, the light shielding layer 210 may be positioned to correspond to a frame area of ​​the display device. According to an embodiment, the light shielding layer 210 may also be omitted.

[0067] The window 300 may be located on the display panel 100 and combined with the display panel 100 through the adhesive layer 220. The window 300 may protect the display panel 100 from external influences.

[0068] A window 300 according to an embodiment includes a base substrate 310 , a first coating layer 320 , and a second coating layer 330 .

[0069] The base substrate 310 may have a plate-like form and may be a glass substrate or a plastic substrate according to an embodiment. Although the present specification shows a structure in which the base substrate 310 is formed as a single layer, it is not limited thereto and the base substrate 310 may also be formed as a plurality of layers.

[0070] As an example, the base substrate 310 may include a glass material including silicate. The glass material may also include additional materials to achieve excellent durability, surface smoothness, and transparency. For example, the base substrate 310 may include aluminosilicate, borosilicate, boroaluminosilicate, etc. The base substrate 310 may also include alkali metals, alkaline earth metals, oxides thereof, etc., and is not limited to the aforementioned materials.

[0071] The base substrate 310 may include a first surface 311 opposite to the first coating layer 320 and a second surface 312 opposite to the second coating layer 330. In addition, the base substrate 310 includes a vertical surface 315 orthogonal to the first surface 311 and the second surface 312.

[0072] The first coating layer 320 is located between the base substrate 310 and the adhesive layer 220. The first coating layer 320 according to an embodiment may overlap the first surface 311 and the vertical surface 315 of the base substrate 310. The first coating layer 320 may overlap the entirety of the first surface 311 and may overlap a portion of the vertical surface 315. However, it is not limited thereto, and the first coating layer 320 may also overlap the entirety of the vertical surface 315.

[0073] The first coating layer 320 can improve the impact resistance of the window 300. When the base substrate 310 is impacted, the first coating layer 320 can offset the stress generated on the base substrate 310 due to the impact, thereby preventing the base substrate 310 from being damaged. The first coating layer 320 can absorb the impact energy and have good adhesion to the base substrate 310.

[0074] The first coating layer 320 may be in direct contact with the base substrate 310. In addition, the first coating layer 320 may also overlap with the adhesive layer 220 and the light shielding layer 210. The first coating layer 320 according to an embodiment may be in a state of chemically bonding with the base substrate 310. As an example, the first coating layer 320 may be in a state of covalently bonding with the Si-O bond of the base substrate 310. Since the first coating layer 320 and the first surface 311 of the base substrate 310 are in a state of being connected by an extremely strong bonding force, they may have a morphology showing excellent bonding force and being completely attached.

[0075] The first coating layer 320 may be formed on the base substrate 310 by wet coating. For example, the first coating layer 320 may be formed by slide coating, bar coating, spin coating, spray coating, or the like.

[0076] The first coating layer 320 may have a thickness of about 7 μm to about 13 μm. In the case where the thickness of the first coating layer 320 is less than about 7 μm, sufficient impact resistance required for the window may not be provided. In the case where the thickness of the first coating layer 320 exceeds about 13 μm, yellowing may occur on the window. Although the present specification shows an embodiment in which the first coating layer 320 has a uniform thickness relative to the vertical surface 315, it is not limited thereto, and the thickness of the first coating layer 320 may become thinner as it approaches the end of the first coating layer 320.

[0077] The first coating layer 320 may include a hardened body hardened from the first solution.

[0078] The first solution may include a primary binder, a defoamer, and a leveling agent. The primary binder may include METHYL T POLYDIMETHYLSILOXANE, the defoamer may include Octamethylcyclotetrasiloxane, and the leveling agent may include DIMETHYLSILOXANE. The first solution may also include a solvent, and as an example, the solvent may be diethylene glycol monobutyl ether.

[0079] The first solution may include 70wt% to 80wt% of a main binder relative to the entire content of the first solution, 1wt% to 5wt% of a defoaming agent relative to the entire content of the first solution, 0.1wt% to 0.8wt% of a leveling agent relative to the entire content of the first solution, and the remainder being a solvent.

[0080] According to an embodiment, the first solution may further include melamine resin. The content of the melamine resin may be 8wt% to 12wt% relative to the entire content of the first solution. The melamine resin may improve the alkali resistance of the window.

[0081] The first solution may have a viscosity of about 6 cps to about 8 cps.

[0082] The first coating layer 320 including the hardened body hardened by the first solution may include a main binder, a defoaming agent, and a leveling agent remaining on the first coating layer 320. According to one embodiment, the first coating layer 320 may include at least one of METHYL T POLYDIMETHYLSILOXANE, Octamethylcyclotetrasiloxane, and DIMETHYLSILOXANE.

[0083] The second coating layer 330 is located on the outer peripheral surface of the window 300. The second coating layer 330 may overlap the second surface 312 of the base substrate 310. The second coating layer 330 may be located on the second surface 312 directly touched by a user. The second coating layer 330 may improve the surface hardness of the window 300.

[0084] The second coating layer 330 may include one or more selected from the group consisting of organic matter, inorganic matter and organic-inorganic composite compound. The organic matter may include acrylic compound, epoxy compound or a combination thereof, the inorganic matter may include silicon dioxide, aluminum oxide or a combination thereof, and the organic-inorganic composite compound may include polysilsesquioxane.

[0085] The second coating layer 330 may be a single layer or a multi-layer. The thickness of the second coating layer 330 may be about 10 μm to about 30 μm.

[0086] The second coating layer 330 may include an anti-fingerprint layer or an anti-reflection layer, etc. The problem of fingerprints being stained on the surface of the window may be solved by the anti-fingerprint layer, or the problem of increased reflectivity of external light may be solved by the anti-reflection layer.

[0087] The display device including the window according to an embodiment can provide sufficient impact resistance and rigidity by providing the first coating layer 320 having a very small thickness on the base substrate 310. Therefore, the weight and volume of the window 300 itself can be reduced, and the cost consumed in manufacturing the window 300 can be reduced. Since the weight and volume occupied by the window 300 are reduced, the weight and volume of the display device including such a window 300 can also be reduced. In addition, the space generated by the window 300 with a reduced thickness can also be used to increase the capacity of the battery provided in the display device.

[0088] Refer to below Figure 1b A window according to an embodiment and a display device including the window are described. Figure 1b is a schematic cross-sectional view of a display device including a window according to an embodiment. Figure 1a Descriptions of the same structures as the components described in will be omitted.

[0089] The window 300 according to an embodiment may include a base substrate 310 and a first coating layer 320. Figure 1a The second coating layer 330 in the embodiment shown in FIG. The window 300 according to an embodiment may include only the first coating layer 320 located at the first surface 311 of the base substrate 310 .

[0090] Refer to below Figure 2 A display device including a window according to an embodiment is described. Figure 2 2 is a cross-sectional view of a display device including a window according to an embodiment. Description of components identical or similar to the aforementioned components will be omitted.

[0091] The display device according to an embodiment may include a housing 400 surrounding the display panel 100 and the window 300. The housing 400 is not limited to the form shown in the drawings, and may have any form surrounding the display panel 100 and the window 300.

[0092] A window 300 according to an embodiment includes a base substrate 310 , a first coating layer 320 , and a second coating layer 330 .

[0093] The base substrate 310 includes a first surface 311 opposite to the first coating layer 320, a second surface 312 opposite to the second coating layer 330, and a vertical surface 315 orthogonal to the first surface 311 and the second surface 312. The first surface 311 is a surface of the base substrate 310 facing the display panel 100, and the second surface 312 is a surface of the base substrate 310 facing the user.

[0094] The base substrate 310 includes a first inclined surface 313 inclined relative to the first surface 311, and the first inclined surface 313 is a surface connecting the first surface 311 and the vertical surface 315. The base substrate 310 may include a second inclined surface 314 inclined relative to the second surface 312. The second inclined surface 314 is a surface connecting the second surface 312 and the vertical surface 315.

[0095] The first coating layer 320 is located between the base substrate 310 and the adhesive layer 220. The first coating layer 320 according to an embodiment may overlap the first surface 311, the first inclined surface 313, and the vertical surface 315 of the base substrate 310. The first coating layer 320 may overlap the entirety of the first surface 311 and the entirety of the first inclined surface 313. Although the present specification shows an embodiment in which the first coating layer 320 overlaps the entirety of the vertical surface 315, it is not limited thereto, and the first coating layer 320 may also overlap a portion of the vertical surface 315.

[0096] The first coating layer 320 not only overlaps the first surface 311 of the base substrate 310, but also overlaps the first inclined surface 313 and the vertical surface 315, thereby improving the impact resistance of the window 300. When an impact is applied to the base substrate 310, the first coating layer 320 can offset the stress generated on the base substrate 310 due to the impact, thereby preventing the base substrate 310 from being damaged.

[0097] In addition, when the base substrate 310 according to one embodiment is a glass material, as shown in FIG. Figure 2 As shown in FIG. 1 , a surface of the base substrate 310 may have a flaw. The flaw may be a defect and may cause damage to the window 300 .

[0098] The first coating layer 320 according to an embodiment may fill the surface of the base substrate 310 where a flaw is formed. The first coating layer 320 may have a shape that fills the flaw. The first coating layer 320 may completely cover the flaw, thereby reducing the possibility of damage to the window 300.

[0099] The second coating layer 330 may overlap the second surface 312 of the base substrate 310. In addition, although the second coating layer 330 may overlap a portion of the second inclined surface 314, it is not limited thereto.

[0100] The display device including the window 300 according to an embodiment can prevent the window 300 from being damaged by improving the impact resistance of the window 300 through the first coating layer 320 covering the first surface 311 , the first inclined surface 313 , and the vertical surface 315 of the base substrate 310 .

[0101] Refer to below Figures 3 to 6 A window according to an embodiment is described. Figures 3 to 6 The window can be replaced Figure 2 The window shown in . Figure 3 is a cross-sectional view of a window according to an embodiment, Figure 4 is a cross-sectional view of a window according to another embodiment, Figure 5 is a cross-sectional view of a window according to yet another embodiment, and Figure 6 2 is a cross-sectional view of a window according to another embodiment. The description of the same or similar structure as the aforementioned window will be omitted.

[0102] Reference Figure 3 , the end 321 of the first coating layer 320 may have a shape inclined toward the vertical surface 315 of the base substrate 310. The first coating layer 320 may be formed of a solution having a predetermined viscosity. In the process of coating the solution and hardening the solution, the end 321 of the first coating layer 320 may have a tapered shape toward a surface of the base substrate 310. The thickness of the end 321 of the first coating layer 320 may become thinner along the vertical surface 315 of the base substrate 310.

[0103] Although this specification shows an embodiment in which the end 321 of the first coating layer 320 is aligned with the end of the vertical surface 315, it is not limited thereto, and any embodiment in which the end 321 of the first coating layer 320 is located on the second inclined surface 314 or on the vertical surface 315 is possible.

[0104] Reference Figure 4, the second coating layer 330 may be located not only on the second surface 312 of the base substrate 310, but also on the second inclined surface 314. According to an embodiment, the second coating layer 330 may completely cover the second inclined surface 314, and may contact the first coating layer 320. Although the first coating layer 320 and the second coating layer 330 may contact at the end where the second inclined surface 314 meets the vertical surface 315, it is not limited thereto, and according to an embodiment, the contact surface of the first coating layer 320 and the second coating layer 330 may also be located on the second inclined surface 314.

[0105] In addition, although the present specification shows a structure in which a surface at the end of the first coating layer 320 contacts a surface at the end of the second coating layer 330, it is not limited to this, and may also be in a form in which the end of the second coating layer 330 covers the end of the first coating layer 320 or the end of the first coating layer 320 covers the end of the second coating layer 330.

[0106] Reference Figure 5 The second inclined surface 314 connecting the second surface 312 of the base substrate 310 and the vertical surface 315 may include a convex curved surface. Although the second inclined surface 314 having a convex curved surface is shown in the present specification, it is not limited thereto and may also include a concave curved surface.

[0107] Since the first inclined surface 313 of the base substrate 310 is a flat surface and the second inclined surface 314 is a curved surface, the base substrate 310 may have an asymmetric shape along the y-axis direction.

[0108] Reference Figure 6 According to an embodiment, the second coating layer 330 may overlap the second surface 312 of the base substrate 310 and the curved second inclined surface 314. The second coating layer 330 may completely cover the second inclined surface 314 and, according to an embodiment, may contact the first coating layer 320.

[0109] The first coating layer 320 and the second coating layer 330 may contact each other at the end where the curved second inclined surface 314 meets the vertical surface 315. However, this is not limited thereto, and the boundary where the first coating layer 320 and the second coating layer 330 contact each other may be located on the second inclined surface 314 or on the vertical surface 315.

[0110] In addition, although the present specification shows a structure in which a surface at the end of the first coating layer 320 contacts a surface at the end of the second coating layer 330, it is not limited to this, and may also be in a form in which the end of the second coating layer 330 covers the end of the first coating layer 320 or the end of the first coating layer 320 covers the end of the second coating layer 330.

[0111] This manual refers to Figures 3 to 6 The window 300 according to an embodiment is described, and it is apparent that the structures included in each window 300 may be combined for implementation.

[0112] Refer to below Figure 7 A method for manufacturing a window according to an embodiment is briefly described. Figure 7 is a view showing a manufacturing process of a window according to an embodiment. Figure 7 The base substrate is a flat plate having a rectangular shape, but the base substrate may have a shape such as Figures 3 to 6 Many variations are possible as shown in .

[0113] Reference Figure 7 , plasma treatment is performed on the first surface 311 of the base substrate 310. The plasma treatment may be performed at N 2 or in an argon atmosphere.

[0114] Subsequently, the first solution is coated on the first surface 311 of the plasma-treated base substrate 310. The first surface 311 of the plasma-treated base substrate 310 may have excellent bonding with the first solution. Although there is no limitation on the coating method, according to one embodiment, spray coating may be used.

[0115] Subsequently, the applied solution may be hardened at 170 degrees (° C.) for 30 minutes to form the first coating layer 320 on the first surface 311 of the base substrate 310 .

[0116] Refer to below Figures 8 to 16 Windows according to Examples and Comparative Examples are described. Figure 8 is a graph showing the break energy for Examples and Comparative Examples. Fig. 9 Yes Figure 8 A chart showing the results of the falling ball test performed on the embodiments and comparative examples, Fig.10 is a graph showing the destruction energy according to the thickness of the first coating layer, Fig.11 is a graph showing the destructive energy according to whether or not a plasma process is performed and the process sequence, Fig.12 is a graph showing the destructive energy according to the embodiment and the comparative example, Fig.13 Yes Fig.12 A chart showing the results of the falling ball test performed on the embodiments and comparative examples, Fig.14 This is a graph showing the results of testing the height of the bright spot in the comparative example and the embodiment. Fig.15 is a graph showing the results of testing the impact resistance of the comparative example and the embodiment, and Fig.16 The images are the results of the crack growth test on the comparative example and the embodiment.

[0117] Reference Figure 8 , Comparative Example 1 is a base substrate having a destruction energy of about 0.7 J. For Example 1 in which a first coating layer according to an embodiment is formed on the same base substrate, the destruction energy is shown to be about 0.95 J. It can be confirmed that Example 1 has a destruction energy increased by about 1.4 times compared to Comparative Example 1.

[0118] Comparative Example 2 is a base substrate having a destruction energy of about 0.61 J. For Example 2 in which a first coating layer according to an embodiment is formed on the same base substrate, the destruction energy is shown to be about 0.89 J. It can be confirmed that Example 2 has a greater destruction energy of about 1.5 times than Comparative Example 2.

[0119] Comparative Example 3 is a base substrate having a destruction energy of about 0.53 J. For Example 3 in which a first coating layer according to an embodiment is formed on the same base substrate, the destruction energy is shown to be about 0.9 J. It can be confirmed that Example 3 has a greater destruction energy of about 1.7 times than Comparative Example 3.

[0120] Comparative Example 4 is a base substrate having a destruction energy of about 0.59 J. For Example 4 in which a first coating layer according to an embodiment is formed on the same base substrate, the destruction energy is shown to be about 1.20 J. It can be confirmed that Example 4 has a greater destruction energy of about 2.0 times than Comparative Example 4.

[0121] According to the results of comparing Comparative Examples 1 to 4 with Examples 1 to 4, it can be confirmed that the window including the first coating layer has a greater destruction energy of about 1.4 to 2.0 times than the window not including the first coating layer. The destruction energy represents the energy required to break the window, and the greater the destruction energy, the better the impact resistance of the window. That is, it can be confirmed that the impact resistance of the window according to the embodiment is improved.

[0122] Fig. 9 Shows the Figure 8 The results of the ball drop test on the windows of Examples 1 to 4 and Comparative Examples 1 to 4 are shown. The ball drop test was repeated multiple times, and the quartiles are shown in the graph.

[0123] The ball drop test is to drop a 151g metal ball onto the window from different heights and record the maximum height at which the window does not whiten or crack. The ball drop test is an experiment to measure the impact resistance of the window, and the higher the maximum height, the better the impact resistance.

[0124] according to Fig. 9It can be confirmed that the limit height of Comparative Example 1 is about 47.1cm, and the limit height of Example 1 is about 64.3cm. It can be confirmed that the limit height of Comparative Example 2 is about 41.3cm, and the limit height of Example 2 is about 60.0cm. It can be confirmed that the limit height of Comparative Example 3 is 36.0cm, and the limit height of Example 3 is 61.1cm. It can be confirmed that the limit height of Comparative Example 4 is 40.0cm, and the limit height of Example 4 is 81.3cm. It can be confirmed that Examples 1 to 4 have greater limit heights than Comparative Examples 1 to 4. It can be confirmed that the impact resistance of the window is excellent when the first coating layer is included as in the embodiment.

[0125] Reference Fig.10 , in the case of a base substrate without the first coating layer, it can have a destruction energy of about 0.59 J. At this time, the base substrate is subjected to multiple coating processes, and the change in the destruction energy according to the thickness of the first coating layer is observed. A coating layer with a thickness of about 2 μm can be formed by a single coating process (scan).

[0126] First, in the case where a 2 μm thick first coating layer is formed on the base substrate by implementing a single coating process, the damage energy increases to about 0.85 J. In the case where a 6 μm thick first coating layer is formed on the base substrate by three coating processes, the damage energy increases to about 0.92 J. In the case where a 10 μm thick first coating layer is formed on the base substrate by five coating processes, the damage energy increases to about 1.20 J. In the case where a 14 μm thick first coating layer is formed on the base substrate by seven coating processes, the damage energy decreases to about 0.85 J.

[0127] According to the above content, the impact resistance is not simply improved as the thickness of the first coating layer increases, but when the thickness of the first coating layer is about 7μm to about 13μm, the impact resistance is optimal and the rigidity effect of the first coating layer is the greatest.

[0128] [Table 1]

[0129] Uncoated One-time coating Three coatings Five coatings Seven coatings Yellowing Index (YI) 0.23 0.25 0.30 0.34 0.68

[0130] In addition, it can be confirmed from the above Table 1 that the base substrate in a state without the first coating layer has a yellowing index of 0.23, and as the number of coatings increases, the yellowing index of the window increases. In particular, it can be confirmed that the yellowing index increases significantly when the coating process is performed seven times compared to the case of performing the coating process five times.

[0131] according to Fig.10As shown in Table 1, when the thickness of the first coating layer is too thin or too thick, the destruction energy may be small. In addition, when the thickness of the first coating layer is too thick, the yellowing index of the window may be large. It can be confirmed that in order to meet the impact resistance and transparency required for the window, the first coating layer according to an embodiment may have a thickness of about 7 μm to about 13 μm.

[0132] Next, Fig.11 Comparative Example 1 in the example includes only a base substrate and has a destruction energy of 0.59 J. Comparative Example 2 includes a first coating layer formed on a base substrate without performing a plasma treatment process, and Comparative Example 3 includes a plasma process after forming the first coating layer on the base substrate. Example 1 includes a first coating layer formed after surface treatment of one surface of the base substrate by a plasma process, and Example 2 is the same as Example 1 but additionally performs a plasma treatment process after forming the first coating layer.

[0133] Comparative Example 1 was shown to have a destruction energy of about 0.59 J, Comparative Example 2 was shown to have a destruction energy of about 0.92 J, and Comparative Example 3 was shown to have a destruction energy of about 0.89 J. In addition, Example 1 was shown to have a destruction energy of about 1.20 J, and Example 2 was shown to have a destruction energy of about 1.15 J.

[0134] Examples 1 and 2 have excellent destruction energy values ​​compared to Comparative Examples 1 to 3. It can be confirmed that when a plasma treatment process is performed on the surface of the base substrate before forming the first coating layer, the bonding force between the base substrate and the first coating layer is improved, so that the window has excellent impact resistance.

[0135] [Table 2]

[0136]

[0137] The contact angle of ultrapure water to the base substrate is shown in Table 2. It was confirmed that the contact angle of the base substrate without additional surface treatment as in Comparative Example 1 was 65 degrees, while the contact angle after washing one surface of the base substrate was 25 degrees.

[0138] In addition, after the surface of the base substrate was plasma treated as in Example 1, the contact angle of ultrapure water was about 5 degrees. The surface of the base substrate was hydrophilic by the plasma treatment process. It can be confirmed that the contact angle of ultrapure water after the first coating layer was formed was 80 degrees, and when the coating layer was plasma treated, a contact angle of about 5 degrees was shown.

[0139] According to Table 2, one surface of the base substrate subjected to the hydrophilic treatment may have excellent bonding force with respect to the solution for forming the first coating layer. In addition, the solution for forming the first coating layer may be uniformly distributed on the base substrate.

[0140] Next, according to Fig.12 , Comparative Example 1 is a case where the thickness of the base substrate is 650 μm, and Example 1 is a case where the base substrate and the first coating layer of Comparative Example 1 are included. Comparative Example 2 is a case where the thickness of the base substrate is 750 μm, and Example 2 is a case where the base substrate and the first coating layer of Comparative Example 2 are included.

[0141] according to Fig.12 It can be seen that Comparative Example 1 has a fracture energy of about 0.59 J, and Example 1 has a fracture energy of about 1.20 J. It can be confirmed that in the case of including the first coating layer, the fracture energy increases by about 2 times.

[0142] It was confirmed that Comparative Example 2 had a fracture energy of about 1.09 J, and Example 2 had a fracture energy of about 1.63 J. It was confirmed that, in the case of Example 2 as well, the fracture energy increased with the inclusion of the first coating layer.

[0143] Furthermore, when the comparative example 1 is compared with the case where the thickness of the base substrate is increased by 100 μm as in the comparative example 2, the increased destruction energy is about 0.5 J. In addition, when the comparative example 1 is compared with the embodiment 1, it can be confirmed that in the case where the first coating layer having a thickness of 10 μm is additionally included, the destruction energy is increased by about 0.61 J. Since stronger impact resistance can be provided by including a coating layer having a small thickness, the thickness and weight of the window can be reduced.

[0144] Fig.13 It shows Fig.12 The drop ball test is the same as the above drop ball test, and a 130 g steel ball is used in this experiment.

[0145] Reference Fig.13 , the limit height of Comparative Example 1, which includes a base substrate with a destruction energy of 0.59 J, is about 46.5 cm. The limit height of Example 1, which adds a first coating layer relative to Comparative Example 1, is about 94.4 cm. The limit height of Comparative Example 2, which includes a base substrate with a destruction energy of 1.09 J, is about 85.6 cm. The limit height of Example 2, which adds a second coating layer relative to Comparative Example 2, is about 128.3 cm.

[0146] When the case where the thickness of the base substrate was increased by 100 μm as in Comparative Example 1 and Comparative Example 2 was compared, the limit height increased by about 40 cm. In addition, by observing Comparative Example 1 and Example 1, it was confirmed that in the case where the first coating layer having a thickness of 10 μm was additionally included, the limit height increased by about 48 cm. It was confirmed that a stronger impact resistance can be provided by a coating layer having a small thickness.

[0147] Reference Fig.14 The height of the bright spot was measured for the comparative example including only the base substrate and the example including the base substrate and the first coating layer. A 30 g drop jig was used to apply an impact, and whether a bright spot was generated was confirmed.

[0148] In the case of the comparative example, the maximum height of the generated bright spot was shown to be about 30 cm, and in the case of the embodiment, the maximum height of the generated bright spot was shown to be about 36 cm. In addition, as a result of repeated multiple tests on the comparative example and the embodiment, it can be confirmed that, with respect to the number of generated bright spots, 6 were generated in the comparative example, and 3 were generated in the embodiment, based on 10 pieces. It can be confirmed that, in the case of the embodiment, the impact resistance is improved.

[0149] Reference Fig.15 , the windows according to the comparative example and the embodiment were combined with the model panel, and the height at which the window broke with free fall was measured. The display device combined with the window and the model panel was dropped onto a granite substrate from a height of 50 cm. It can be confirmed that in the case of the comparative example, the window broke from about 90 cm, and in the case of the embodiment, the window broke from about 110 cm. It can be confirmed that for the display device including the window according to an embodiment, the bonding strength between the display panel and the window is excellent and the impact resistance is improved.

[0150] Reference Fig.16 , confirm whether the cracks generated in the windows according to the comparative example and the embodiment grow.

[0151] For the comparative example not including the first coating layer, it can be seen that the cracks are transmitted to the entire window as the base substrate is broken, which shows a morphology in which the impact applied to the predetermined area of ​​the window extends toward the periphery.

[0152] In addition, it can be confirmed that, for the embodiment including the first coating layer, even if cracks are generated in a part of the region, the cracks do not extend to the surrounding region. It can be confirmed that, in the case according to the embodiment, since the impact of the window is easily absorbed, the growth of the cracks is effectively suppressed. That is, even if a part of the region of the window according to the embodiment is damaged, the impact will not be transmitted to the surrounding area, so the amount and length of the crack itself can be suppressed.

[0153] Table 3 below shows the results of triaxial bending tests on the comparative example including the base substrate and the example including the base substrate and the first coating layer.

[0154] As shown in Table 3, it can be confirmed that the maximum breaking strength increased from 553.10N to 715.25N, the maximum bending elongation increased from 4.16mm to 5.55mm, that is, increased by about 1.3 times, the bending strength increased from 843.53mPa to 1097.30mPa, that is, increased by about 1.3 times, and the elongation increased from 1.14% to 1.52%, that is, increased by 1.3 times.

[0155] [Table 3]

[0156]

[0157] Table 4 below shows the results of a four-axis bending test on the comparative example including a base substrate and the example including a base substrate and a first coating layer.

[0158] It can be confirmed that the average value (Avg) of the results of measuring the bending elastic modulus increased from 933.43mPa to 1273.94mPa, that is, increased by 1.4 times, and the value of the smallest 10% of the bending elastic modulus values ​​(B10) increased from about 665.36mPa to 1060.18mPa, that is, increased by 1.6 times. In addition, it can be confirmed that the maximum breaking strength increased from 961.87N to 1312.76N.

[0159] [Table 4]

[0160]

[0161] As can be seen from the foregoing, a display device including a window according to the embodiment can improve the impact resistance of the window by the first coating layer covering the back and vertical surfaces of the base substrate, thereby preventing the window from being damaged.

[0162] Although the embodiments of the present invention are described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concepts of the present invention defined in the appended claims also fall within the scope of the present invention.

Claims

1. A window for a display device, comprising: A base substrate comprising a first surface, a second surface opposite to the first surface, a first inclined surface inclined relative to the first surface, and a second inclined surface inclined relative to the second surface, and a first coating layer disposed directly on the first surface of the base substrate and configured to fix the base substrate to the display device, wherein the first coating layer directly overlaps the first inclined surface and the second inclined surface, and The first coating layer includes at least one of methyl-T-polydimethylsiloxane, octamethylcyclotetrasiloxane and dimethylsiloxane.

2. The window according to claim 1, wherein: The base substrate further includes a vertical surface perpendicular to the first surface and the second surface, and the first coating layer directly overlaps the vertical surface.

3. The window according to claim 2, wherein: The first inclined surface connects the first surface and the vertical surface.

4. The window according to claim 2, wherein: The second inclined surface connects the second surface and the vertical surface.

5. The window according to claim 1, wherein: The base substrate and the first coating layer are covalently bonded to each other.

6. The window of claim 1, wherein: The first surface of the base substrate includes grooves, and the first coating layer fills the grooves.

7. The window of claim 1, wherein: The second surface does not directly contact the first coating layer.

8. A display device, comprising: Display panel; as well as a window configured to cover the display panel, Wherein, the window comprises: A base substrate comprises a first surface, a second surface opposite to the first surface, a first inclined surface inclined relative to the first surface, and a second inclined surface inclined relative to the second surface, a first coating layer disposed directly on the first surface of the base substrate and configured to fix the base substrate to the display device, wherein the first coating layer directly overlaps the first inclined surface and the second inclined surface, and The first coating layer includes at least one of methyl-T-polydimethylsiloxane, octamethylcyclotetrasiloxane and dimethylsiloxane.

9. The display device according to claim 8, wherein: The base substrate further includes a vertical surface perpendicular to the first surface and the second surface, and the first coating layer directly overlaps the vertical surface.

10. The display device according to claim 9, wherein: The first inclined surface connects the first surface and the vertical surface.

11. The display device according to claim 9, wherein: The second inclined surface connects the second surface and the vertical surface.

12. The display device according to claim 8, wherein: The base substrate and the first coating layer are covalently bonded to each other.

13. The display device according to claim 8, wherein: The first surface of the base substrate includes grooves, and the first coating layer fills the grooves.

14. The display device according to claim 8, wherein: The second surface does not directly contact the first coating layer.

15. The display device according to claim 8, further comprising: An adhesive layer and a light shielding layer are provided between the first coating layer and the display panel.

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