Adhesive member and display device including the same

Abstract

A display device and an adhesive member are provided. The display device according to an embodiment of the disclosure includes a display panel, a cover window disposed on the display panel, and a first adhesive member disposed between the display panel and the cover window, wherein the first adhesive member contains a urethane monomer, and the urethane monomer includes 5 wt% or more and 10 wt% or less of 2,6-diisopropylphenyl isocyanate (2,6-DIPPI) with respect to the total weight of the first adhesive member.

Description

Technical Field

[0001] This disclosure relates to adhesive components and display devices including adhesive components. Background Technology

[0002] With the advancement of multimedia, display devices have become increasingly important in providing high-quality images. In response to this trend, various types of display devices have been developed, such as organic light-emitting diode (OLED) displays and liquid crystal displays (LCDs). These diverse types of display devices have diversified their applications in various mobile electronic devices, such as portable electronic devices like smartphones, smartwatches, and tablet PCs.

[0003] The display device may include a display panel for generating screen images, a cover window covering the display panel, and an adhesive component for adhering the cover window to the display panel.

[0004] After the display panel and cover window are attached to each other by adhesive components, air bubbles may remain in the adhesive components, and the design of the display device may be limited because the penetration depth of the residual air bubbles becomes longer. Summary of the Invention

[0005] This disclosure relates to providing an adhesive component that can reduce the occurrence of air bubbles during the manufacturing process of a display device, and a display device including said adhesive component. For example, this disclosure provides an adhesive component that can reduce the occurrence of air bubbles after an autoclave process by bonding a display panel to a cover window, and a display device including said adhesive component.

[0006] The aspects of this disclosure are not limited to those mentioned above, and other features of this disclosure (not mentioned herein) will be clearly understood by those skilled in the art based on the following description of this disclosure.

[0007] According to an embodiment of the present disclosure, the display device includes: a display panel; a cover window disposed on the display panel; and a first adhesive member disposed between the display panel and the cover window, wherein the first adhesive member comprises a urethane monomer, and the urethane monomer comprises 2,6-diisopropylphenyl isocyanate (2,6-DIPPI) in an amount of more than about 5 wt% and less than about 10 wt% relative to the total weight of the first adhesive member.

[0008] According to an embodiment of this disclosure, the display device includes: a display panel; a cover window disposed on the display panel; and an adhesive member disposed between the display panel and the cover window, wherein the adhesive member is manufactured as a cylindrical sample having a diameter of 8 mm and a height of 600 μm, and exhibits approximately 100% or less of the maximum strain during a creep test of the sample at 60°C for 600 seconds under a shear stress of 2000 Pa, and the adhesive member exhibits a shear stress of more than 3000 Pa and less than 4000 Pa during a stress relaxation test of the cylindrical sample at 60°C with a strain of 25%.

[0009] According to embodiments of this disclosure, the adhesive component comprises an acrylic monomer; a urethane monomer; and a photoinitiator, wherein the urethane monomer comprises 2,6-diisopropylphenyl isocyanate (2,6-DIPPI) in an amount of more than about 5 wt% and less than about 10 wt% relative to the total weight.

[0010] According to embodiments of this disclosure, a display device includes: a display panel; a cover window disposed on the display panel; and an adhesive member disposed between the display panel and the cover window, wherein the adhesive member comprises: a urethane monomer; a photoinitiator; and an acrylic monomer. Relative to the total weight of the adhesive member, the acrylic monomer comprises about 45 wt% and more but less than about 55 wt% of 2-ethylhexyl acrylate (2-EHA); more than 0 wt% and less than about 5 wt% of methyl methacrylate; about 10 wt% and more but less than about 20 wt% of octyl methacrylate; and about 20 wt% and more but less than about 30 wt% of 2-hydroxyethyl acrylate (2-HEA). Attached Figure Description

[0011] The above and other aspects and features of this disclosure will become more apparent from the exemplary embodiments described in detail with reference to the accompanying drawings, in which:

[0012] Figure 1 This is a perspective view illustrating a display device according to an embodiment of the present disclosure;

[0013] Figure 2 It is along Figure 1 A cross-sectional view taken from line II-II';

[0014] Figure 3 It is along Figure 1 A cross-sectional view taken from line III-III';

[0015] Figure 4This is a schematic diagram illustrating the bonding process of a cover window in a display device according to an embodiment of the present disclosure;

[0016] Figure 5 and Figure 6 This is a cross-sectional view illustrating an autoclave process according to an embodiment of the present disclosure;

[0017] Figure 7 and Figure 8 This is a schematic diagram illustrating the creep test and stress relaxation test process;

[0018] Figure 9 This is an example. Figure 7 and Figure 8 A graph showing the results of the creep test; and

[0019] Figure 10 This is an example. Figure 7 and Figure 8 The figure shows the results of the stress relaxation test.

[0020] because Figures 1 to 8 The accompanying drawings are for illustrative purposes only, and therefore the elements in the drawings are not necessarily drawn to scale. For example, some elements may be enlarged or scaled up for clarity. Detailed Implementation

[0021] Detailed embodiments of this disclosure will be described below with reference to the accompanying drawings.

[0022] Figure 1 This is a perspective view illustrating a display device according to an embodiment of the present disclosure.

[0023] refer to Figure 1 The display device 1 can be provided in a rectangular shape on a plane. For example, the display device 1 may include a short side extending along a first direction X and a long side extending along a second direction Y. The corner where the short side extending along the first direction X intersects the long side extending along the second direction Y may be rounded to have a predetermined curvature or formed as a right angle. The planar shape of the display device 1 is not limited to a rectangular shape or other quadrilateral shapes, and may be formed into a circular shape, an elliptical shape, or other polygonal shapes, such as a triangular shape, a pentagonal shape, or a hexagonal shape.

[0024] In the embodiments of this disclosure, the first direction X and the second direction Y are different from each other and intersect each other. Figure 1In this embodiment, the first direction X can refer to the extension direction of the short side of the display device 1, and the second direction Y can refer to the extension direction of the long side of the display device 1. Furthermore, the third direction Z can refer to the direction intersecting the first direction X and the second direction Y. In embodiments of this disclosure, the first direction X, the second direction Y, and the third direction Z can be perpendicular to each other. However, it should be understood that the directions mentioned in the embodiments refer to relative directions, and the embodiments are not limited to the mentioned directions.

[0025] Display device 1 may include a planarized portion MR comprising a flat surface, and an edge portion SR extending from at least one side of the planarized portion MR. The planar shape of the planarized portion MR may be similar to the planar shape of display device 1. For example, the planarized portion MR may include a short side extending along a first direction X and a long side extending along a second direction Y. In the planarized portion MR, the corner where the short side extending along the first direction X intersects the long side extending along the second direction Y may be rounded to have a predetermined curvature or formed as a right angle. The planar shape of the planarized portion MR may be formed as a circular shape, an elliptical shape, or other polygonal shapes, such as a triangle, pentagon, or hexagon, and is not limited to a rectangular shape or other quadrilateral shapes.

[0026] In embodiments of this disclosure, the central region of the planarized portion MR is flat, and the edge region of the planarized portion MR surrounding the central region can be a curve with a predetermined curvature. However, this disclosure is not limited thereto. For example, in embodiments of this disclosure, the planarized portion MR can be completely flat.

[0027] According to embodiments of this disclosure, edge portions SR can be provided in multiple quantities. For example, four edge portions SR can be provided. Assume that in the long sides of the planarized portion MR, the long side located on one side in the first direction X is called the first long side and the long side located on the other side in the first direction X is called the second long side; and in the short sides of the planarized portion MR, the short side located on one side in the second direction Y is called the first short side and the short side located on the other side in the second direction Y is called the second short side. The edge portions SR may include a first edge portion SR1 extending from the first long side of the planarized portion MR, a second edge portion SR2 extending from the second long side of the planarized portion MR, a third edge portion SR3 extending from the first short side of the planarized portion MR, and a fourth edge portion SR4 extending from the second short side of the planarized portion MR.

[0028] The planarized portion MR may include a first long side and a second long side facing each other along a first direction X, and may include a first short side and a second short side facing each other along a second direction Y.

[0029] In embodiments of this disclosure, the planarized portion MR is generally parallel to the plane defined by the first direction X and the second direction Y. The edge portion SR can be configured to surround the planarized portion MR and can be curved from the planarized portion MR toward the underside of the display device 1. For example, the edge portion SR can be curved from the planarized portion MR to the opposite side in the third direction Z. In other words, the edge portion SR can be located on at least one side of the planarized portion MR and can be curved from the planarized portion MR in the thickness direction of the display device 1 (i.e., the third direction Z). A portion of each edge portion SR may include a curve with a predetermined curvature, and other portions may be flat. Specifically, in the edge portion SR, the area adjacent to the planarized portion MR may be a curve with a predetermined curvature, and other portions may be flat.

[0030] The horizontal (or angle) of each edge portion SR that bends from the planarized portion MR can be an obtuse angle, but it can also be a right angle or an acute angle, and is not limited to an obtuse angle.

[0031] In embodiments of this disclosure, each edge portion SR may include a curve with a predetermined curvature. The curvature of each edge portion SR may be constant in each region, but may be different in each region. Furthermore, in embodiments of this disclosure, the edge portion SR may be completely flat.

[0032] In a view of the screen display, the display device 1 may include a display area DA and a non-display area NDA. The display area DA may be an area on which a screen is displayed, and the non-display area NDA may be an area on which no screen is displayed. For example, the display area DA may be an area in which pixels are arranged to display an image. The non-display area NDA may be an area that does not display an image because no pixels are arranged there. In embodiments of this disclosure, each pixel may include a light-emitting element, such as an organic light-emitting diode. The display area DA may be located at the center of the display device 1, and the non-display area NDA may be located on the periphery of the display area DA. For example, the non-display area NDA may be positioned around the display area DA.

[0033] In embodiments of this disclosure, a portion of the planarized portion MR and a portion of each edge portion SR adjacent to the edge of the planarized portion MR may be located in the display area DA. The planarized portion MR may not be located in the non-display area NDA, and a portion of the edge portion SR may be located in the non-display area NDA. A portion of the edge portion SR located in the non-display area NDA may surround another portion of the edge portion SR located in the display area DA.

[0034] Figure 2 It is along Figure 1A cross-sectional view taken from line II-II'. Figure 3 It is along Figure 1 A cross-sectional view taken from line III-III'.

[0035] refer to Figure 2 and Figure 3 The display device 1 may include a display panel 100, a polarizing member 200 disposed on the display panel 100, a cover window 300 disposed on the polarizing member 200, and a lower cover panel 400 disposed below the display panel 100.

[0036] The display panel 100, polarizing member 200, cover window 300, and lower cover panel 400 can be arranged throughout the planar portion MR and edge portion SR of the display device 1.

[0037] Display panel 100 may include elements and circuitry for displaying images, such as pixel circuitry including switching elements, and self-emissive elements for emitting light by operating the pixel circuitry. In embodiments of this disclosure, the self-emissive element may include at least one of, for example, organic light-emitting diodes (OLEDs), quantum dot OLEDs, inorganic micro-LEDs (e.g., microLEDs), or inorganic OLEDs (e.g., nanoLEDs) having at least one nanometer-sized width or length. In embodiments of this disclosure, the pixel circuitry may include at least driving thin-film transistors (TFTs), switching TFTs, and storage capacitors. The number of TFTs and storage capacitors may vary in various ways depending on the design of the pixel circuitry. For example, the pixel circuitry may include three or more TFTs and / or two or more storage capacitors. Display panel 100 may include one surface oriented toward polarizing member 200 and cover window 300 and another surface oriented toward lower cover panel 400.

[0038] A polarizing member 200 may be disposed on the display panel 100. Specifically, the polarizing member 200 may be disposed on one surface of the display panel 100. The polarizing member 200 may be used to reduce external light reflection and may be attached to the display panel 100 by a second adhesive member 502. For example, the polarizing member 200 may reduce the reflectivity of external light incident on the cover window 300 from above. The second adhesive member 502 may be disposed between the polarizing member 200 and the display panel 100 and may be optically transparent. For example, the second adhesive member 502 may be, but is not limited to, an optically transparent adhesive or an optically transparent resin.

[0039] This disclosure is not limited to the above description. For example, in embodiments of this disclosure, the polarizing member 200 may be omitted. The polarizing member 200 may be integrated into the display panel 100. When the polarizing member 200 is omitted, the cover window 300 and the display panel 100 can be directly adhered to each other via the first adhesive member 501, with the second adhesive member 502 omitted. Hereinafter, an exemplary description will be given based on the provision of the polarizing member 200.

[0040] A cover window 300 may be disposed above the polarizing member 200. The cover window 300 may be disposed above the display panel 100 to protect the display panel 100 and to transmit light emitted from the display panel 100. The cover window 300 may be made of a transparent insulating material and may also contain a rigid material, such as glass or quartz. In embodiments of this disclosure, the cover window 300 may contain plastic. For example, the cover window 300 may be a transparent polyimide film.

[0041] The overlay window 300 can be configured to overlap the display panel 100 and cover the entire surface of the display panel 100. Therefore, the overlay window 300 can protect the surface of the display panel 100 (wherein the surface is oriented towards the polarizing member 200 and the overlay window 300) and can indicate the display surface on which an image is displayed. The overlay window 300 generally has a shape similar to that of the display panel 100 in a plane, but its size can be larger than that of the display panel 100. For example, the overlay window 300 can protrude further outward than the display panel 100 at the two short sides of the display device 1. Even at the two long sides of the display device 1, the overlay window 300 can protrude from the display panel 100. The length by which the overlay window 300 protrudes further outward than the display panel 100 in a plane can differ between the two long sides and the two short sides. However, this disclosure is not limited thereto. For example, in embodiments of this disclosure, the length by which the overlay window 300 protrudes further outward than the display panel 100 can be equal between the two long sides and the two short sides. The planar shape of the cover window 300 can be the same as the planar shape of the display device 1. For example, the planar shape of the cover window 300 can be a rectangle including two long sides and two short sides.

[0042] The display device 1 may further include an adhesive member 500. Specifically, the display device 1 may further include a first adhesive member 501 disposed between the polarizing member 200 and the cover window 300, a second adhesive member 502 disposed between the display panel 100 and the polarizing member 200, and a third adhesive member 503 disposed between the display panel 100 and the lower cover panel 400. For example, the adhesive member 500 may include the first adhesive member 501, the second adhesive member 502, and the third adhesive member 503.

[0043] The first adhesive component 501 may be disposed between the cover window 300 and the polarizing component 200, and may be used to adhere the polarizing component 200 and the cover window 300 to each other. The first adhesive component 501 may be optically transparent. For example, the first adhesive component 501 may be, but is not limited to, an optically transparent adhesive or an optically transparent resin. Typically, optically transparent adhesives or optically transparent resins may have optical transparency and provide impact resistance. Moreover, the first adhesive component 501 may contain, but is not limited to, the same material as the second adhesive component 502.

[0044] The first adhesive member 501 may cover the inner edge of the printed pattern 600 and a portion of another surface. The first adhesive member 501 may be directly adjacent to the inner edge of the printed pattern 600 and a portion of another surface.

[0045] The display device 1 can be formed by performing an autoclave process after the polarizing member 200 is adhered to the cover window 300 via the first adhesive member 501. For example, the cover window 300 can be adhered to the polarizing member 200 via an adhesive process. In other words, the first adhesive member 501 of the display device 1 according to the embodiments of the present disclosure can be formed by both an adhesive process and an autoclave process. When the display device is restored to room temperature and atmospheric pressure after the autoclave process, the air bubbles present before the autoclave process (see...) Figure 5 The "BB" bubbles may regenerate. When BB bubbles remain in the display device 1, they can contribute to reducing the quality of the display device 1 for the user. Therefore, to prevent the quality of the display device 1 from deteriorating, the first adhesive component 501 can be made of components and compositions that can prevent the generation of BB bubbles after the autoclave process.

[0046] The lower cover panel 400 can be disposed below the display panel 100. Specifically, the lower cover panel 400 can be disposed on another surface of the display panel 100 and can be attached to the rear surface of the display area DA of the display panel 100. The lower cover panel 400 includes at least one functional layer. The functional layer can be a layer that performs functions such as heat dissipation, electromagnetic wave shielding, grounding, buffering, strength enhancement, support, and / or digitization. The functional layer can be a sheet made of a sheet, a film made of a film, a thin film layer, a coating, a panel, a plate, etc. A functional layer can be made of a single layer, but it can also be made of multiple deposited thin films or coatings. The functional layer can be, for example, a support member, a heat dissipation layer, an electromagnetic wave shielding layer, a shock absorption layer, a digitizer, etc.

[0047] The lower cover panel 400 can be attached to another surface of the display panel 100 via a third adhesive member 503. The third adhesive member 503 can be disposed between the lower cover panel 400 and the display panel 100, and can be a pressure-sensitive adhesive (PSA). Alternatively, the third adhesive member 503 can comprise a thermosetting resin and / or a light-curing resin.

[0048] The display device 1 according to an embodiment of this disclosure may further include a printed pattern 600 disposed on a surface oriented from the cover window 300 toward the display panel 100. The printed pattern 600 may be disposed in a non-display area NDA of the display device 1. The printed pattern 600 may extend from an end of the cover window 300 and be configured to partially overlap the display panel 100.

[0049] The printed pattern 600 may include a surface in contact with one surface of the overlay window 300, another surface (which is oriented opposite to the surface of the printed pattern 600), and edges. The edges of the printed pattern 600 may include outer edges and inner edges. The outer edge of the printed pattern 600 may be aligned with the outer edge of the overlay window 300, and the inner edge of the printed pattern 600 may be aligned at the boundary between the non-display area NDA and the display area DA.

[0050] The first adhesive component 501 will be described in detail below. The following description will be based on the first adhesive component 501, but may be applied to the second adhesive component 502 and the third adhesive component 503.

[0051] The first adhesive component 501 comprises an adhesive polymer resin. The adhesive polymer resin is prepared by polymerizing and / or crosslinking the monomers and photoinitiator constituting the first adhesive component 501. Furthermore, monomers and photoinitiators that do not react with each other can be retained in the adhesive polymer resin by being dispersed within it. For example, the monomers contained in the first adhesive component 501 can be polymerized and / or crosslinked to form the adhesive polymer resin, wherein the reaction is catalyzed by free radicals generated by the photoinitiator through a photoprocess and / or a thermosetting process.

[0052] The first adhesive component 501 according to an embodiment of this disclosure may comprise an acrylic monomer and a urethane monomer. Furthermore, the first adhesive component 501 may further comprise a photoinitiator.

[0053] According to an embodiment of this disclosure, the first adhesive component 501 may contain at least one of the following acrylic monomers: 2-ethylhexyl acrylate (2-EHA) represented by Chemical Formula 1, 2-hydroxyethyl acrylate (2-HEA) represented by Chemical Formula 2, methyl methacrylate represented by Chemical Formula 3, octyl methacrylate represented by Chemical Formula 4, isobornyl methacrylate represented by Chemical Formula 5, and methyl acrylate represented by Chemical Formula 6.

[0054] [Chemical Formula 1]

[0055]

[0056] [Chemical Formula 2]

[0057]

[0058] [Chemical Formula 3]

[0059]

[0060] [Chemical Formula 4]

[0061]

[0062] [Chemical Formula 5]

[0063]

[0064] [Chemical Formula 6]

[0065]

[0066] In detail, relative to the total weight, the first adhesive component 501 according to an embodiment of this disclosure may contain more than 45 wt% and less than about 55 wt% of 2-ethylhexyl acrylate (2-EHA) represented by Formula 1, more than 20 wt% and less than about 30 wt% of 2-hydroxyethyl acrylate (2-HEA) represented by Formula 2, more than 0 wt% and less than about 5 wt% of methyl methacrylate represented by Formula 3, and more than 10 wt% and less than about 20 wt% of octyl methacrylate represented by Formula 4. The term “about” as used herein includes a specified value and means within an acceptable range of deviation from a specific value as determined by a person skilled in the art considering the relevant measurements and the errors associated with the measurement of the specific amount (i.e., limitations of the measurement system). For example, “about” may mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the specified value.

[0067] In the first adhesive component 501, the content of acrylic monomers ranges from about 75 wt% to about 95 wt% relative to the total weight. When the content of acrylic monomers is about 75 wt% to about 95 wt%, the curing of the first adhesive component 501 can be actively carried out by exposure. When the content of acrylic monomers is about 75 wt% to about 95 wt%, excellent strength of the first adhesive component 501 can be obtained. For example, when a large portion of the first adhesive component 501 is polymerizable and / or crosslinkable, the resulting adhesive polymer resin can have excellent strength.

[0068] In addition to the acrylic monomer, the first adhesive component 501 according to an embodiment of this disclosure may further comprise about 5 wt% and about 15 wt% of 2,6-diisopropylphenyl isocyanate (2,6-DIPPI) represented by the following chemical formula 7 as a urethane monomer. 2,6-diisopropylphenyl isocyanate (2,6-DIPPI) represented by chemical formula 7 can be used as a crosslinking agent. For example, where the polymer chains are extensively linked together by covalent bonds, the polymer can be more rigid, and therefore the first adhesive component 501 can have excellent strength.

[0069] [Chemical Formula 7]

[0070]

[0071] In the first adhesive component 501 according to an embodiment of the present disclosure, the content of 2,6-diisopropylphenyl isocyanate (2,6-DIPPI), represented by Chemical Formula 7, ranges from about 5 wt% to about 15 wt% relative to the total weight. When the content of 2,6-diisopropylphenyl isocyanate (2,6-DIPPI), represented by Chemical Formula 7, is about 5 wt% to about 15 wt%, the curing of the first adhesive component 501 can be actively carried out by exposure. When the content of 2,6-diisopropylphenyl isocyanate (2,6-DIPPI), represented by Chemical Formula 7, is about 5 wt% or greater relative to the total weight of the first adhesive component 501, the first adhesive component 501 can exhibit excellent elasticity at high temperatures, thereby preventing the formation of permeable air bubbles (BBs). Furthermore, when the content of 2,6-diisopropylphenyl isocyanate (2,6-DIPPI) represented by Formula 7 is about 15 wt% or less relative to the total weight of the first adhesive component 501, excessive increase in elasticity of the first adhesive component 501 at high temperatures can be prevented, and the formation of bubbles (BB) can be prevented due to the absence of over-curing. For example, in embodiments of this disclosure, the first adhesive component 501 may comprise a carbamate monomer comprising 2,6-diisopropylphenyl isocyanate (2,6-DIPPI) at a weight of about 5 wt% and about 10 wt% relative to the total weight of the first adhesive component 501.

[0072] The first adhesive component 501 according to an embodiment of this disclosure may further comprise a benzophenone monomer as a photoinitiator. For example, the first adhesive component 501 may comprise at least one of 4-methylbenzophenone represented by the following chemical formula 8 and 2,4,6-trimethylbenzophenone represented by the following chemical formula 9. For example, during photoexposure, 4-methylbenzophenone or 2,4,6-trimethylbenzophenone can generate free radicals to catalyze the polymerization of acrylic acid monomers. In embodiments of this disclosure, the content of the photoinitiator 4-methylbenzophenone or 2,4,6-trimethylbenzophenone contained in the first adhesive component 501 may range from about 0 wt% to about 20 wt% relative to the total weight, but this disclosure is not limited thereto.

[0073] [Chemical Formula 8]

[0074]

[0075] [Chemical Formula 9]

[0076]

[0077] When a creep test is performed at 60°C under a shear stress of 2000 Pa for 600 seconds, the first adhesive component 501 according to an embodiment of this disclosure may exhibit a maximum strain of 100% or less, 80% or less, 70% or less, or 50% or less. The creep test measures the maximum strain exhibited when both ends of the sample SMP are held by the test apparatus TD and then rotated for 600 seconds under a shear stress of 2000 Pa. In this case, the maximum strain may indicate the rotation rate of the sample SMP. For example, 100% strain means one rotation, and 200% strain means two rotations. Further details will be provided later. Figure 7 and Figure 8 Provide a detailed description.

[0078] When a stress relaxation test is performed at 60°C based on a 25% strain, the first adhesive component 501 according to an embodiment of this disclosure can exhibit shear stresses of approximately 2500 Pa to approximately 4500 Pa, approximately 3000 Pa to approximately 4000 Pa, approximately 3200 Pa to approximately 3800 Pa, or approximately 3400 Pa to approximately 3600 Pa. The stress relaxation test is a test that measures the shear stress at 25% strain when a sample SMP having a circular plate or coin shape is held on both sides using a test apparatus TD. Further details will be provided later. Figure 7 and Figure 8 Provide a detailed description.

[0079] The first adhesive component 501 according to an embodiment of this disclosure may have an adhesive strength of about 3400 gf / inch or greater. As described in Example 5, an adhesive strength test was performed between the cover window 300 and the polarizing member 200 using the first adhesive component 501 to obtain an adhesive strength of about 3400 gf / inch or greater. When the polarizing member 200 is omitted, the cover window 300 and the display panel 100 can be directly adhered to each other via the first adhesive component 501. In this case, the adhesive strength between the first adhesive component 501 and the display panel 100, or between the first adhesive component 501 and the cover window 300, may be about 3400 gf / inch or greater. With the first adhesive component 501 positioned between the cover window 300 and the polarizing component 200, the first adhesive component 501 having an adhesive strength of approximately 3400 gf / inch or greater can provide sufficient adhesion to allow the cover window 300 and the polarizing component 200 to adhere to each other.

[0080] Figure 4 This is a schematic diagram illustrating the bonding process of a cover window in a display device according to an embodiment of the present disclosure. Figure 5 and Figure 6 This is a cross-sectional view illustrating an autoclave process according to an embodiment of the present disclosure. In detail, Figure 5 For example, a display device 1 is installed inside the autoclave process chamber CH before the autoclave process, and Figure 6 An example is shown where a display device 1 is installed in the process chamber CH of a high-pressure reactor during the process.

[0081] Reference Figures 4 to 6 Describes the bonding process of the cover window 300 during the manufacturing process of the display device 1.

[0082] The cover window 300 can be adhered to the polarizing member 200 attached to the display panel 100. Specifically, the cover window 300 can be disposed on the polarizing member 200 with the polarizing member 200 disposed on one surface of the display panel 100 and the lower cover panel 400 disposed on the other surface of the display panel 100. In this case, the adhesive member 500, including the first adhesive member 501, the second adhesive member 502, and the third adhesive member 503, can be disposed between the cover window 300, the polarizing member 200, the display panel 100, and the lower cover panel 400, respectively, so that the various components adhere to each other. Specifically, the second adhesive member 502 can be inserted between the display panel 100 and the polarizing member 200 to adhere the display panel 100 to the polarizing member 200, and the third adhesive member 503 can be inserted between the display panel 100 and the lower cover panel 400 to adhere the display panel 100 to the lower cover panel 400.

[0083] The first adhesive component 501 may be disposed on one surface of the polarizing component 200, and the cover window 300 is adhered to said one surface of the polarizing component 200. The first adhesive component 501 may be disposed entirely on one surface of the polarizing component 200.

[0084] First, the cover window 300 can be attached to the first adhesive member 501, which is attached to the polarizing member 200. When the cover window 300 is attached to the first adhesive member 501, air bubbles BB may be generated between the cover window 300 and the polarizing member 200 and then inserted therebetween. Air bubbles BB can be generated by being trapped between the cover window 300 and the polarizing member 200 during the attachment of the cover window 300 to the polarizing member 200. The cover window 300 can be made of a transparent material, so that the air bubbles BB can be easily seen. Moreover, since the cover window 300 can transmit light emitted from the display panel 100, the air bubbles BB trapped between the cover window 300 and the polarizing member 200 can interfere with the light emitted from the display panel 100. Although Figure 5The diagram shows a bubble BB positioned between the cover window 300 and the first adhesive member 501, but this disclosure is not limited thereto. For example, the bubble BB may be inserted into and then surrounded by the first adhesive member 501, or positioned between the first adhesive member 501 and the polarizing member 200. The bubble BB can be a factor that interferes with the recognition of the image provided by the display panel 100. For example, the image quality of the display device 1 may be degraded due to the bubble BB trapped between the cover window 300 and the polarizing member 200. Therefore, the bubble BB can be removed by the autoclave process described later.

[0085] Autoclave processes can be used to enhance the adhesion between bonding targets while simultaneously removing air bubbles (BBs) through high-temperature and high-pressure processes. For example, although autoclave processes can be carried out at a temperature of 60°C and atmospheric pressure of 8 bar, this is not an isolated case; autoclave processes can be carried out at higher temperatures or higher atmospheric pressures, or at lower temperatures or lower atmospheric pressures. Autoclave processes can be carried out in a chamber (CH).

[0086] refer to Figure 5 In the display device 1 prior to the autoclave process, the first adhesive component 501 may have a first thickness a1. The first thickness a1 may refer to the average thickness of the first adhesive component 501 prior to the autoclave process. Furthermore, in the display device 1 prior to the autoclave process, the bubble BB may be disposed between the cover window 300 and the polarizing component 200.

[0087] refer to Figure 6 In the display device 1 during the autoclave process, the first adhesive component 501 may have a second thickness a2 that is thinner than the first thickness a1. The second thickness a2 may refer to the average thickness of the first adhesive component 501 after the autoclave process.

[0088] Air bubbles (BBs) inserted between the cover window 300 and the polarizing member 200 prior to the autoclave process can be removed by the autoclave process. The air bubbles can be melted in the first adhesive member 501 under high pressure, or they can be discharged to the outside and then removed. In this case, although the removal of air bubbles can mean that the air bubbles are completely removed, this disclosure is not limited thereto. For example, the size of the air bubbles can be reduced so that they are not visible to the user, or the air bubbles can be moved to an area overlapping with the printed pattern 600 and then made invisible to the user.

[0089] After the autoclave process, the display device 1 can be restored to room temperature and atmospheric pressure. At this time, the solubility of the bubbles BB in the first adhesive component 501 may decrease due to the pressure reduction from high pressure to atmospheric pressure. Alternatively, the bubbles BB may penetrate into the edge portions of the first adhesive component 501 due to the pressure reduction to atmospheric pressure. Therefore, the removed bubbles BB can be regenerated and become visible. However, in the display device 1 according to the embodiment of the present disclosure, even if the display device 1 is restored to room temperature and atmospheric pressure after the autoclave process, the bubbles BB cannot be regenerated or become visible due to the components and composition of the components constituting the first adhesive component 501. For example, the first adhesive component 501 according to the embodiment of the present disclosure may be made of components and compositions that can prevent the bubbles BB from regenerating after the autoclave process and restoration to room temperature and atmospheric pressure. For example, the first adhesive component 501 according to an embodiment of the present disclosure may contain a component such as 2,6-diisopropylphenyl isocyanate (2,6-DIPPI) at a weight of more than about 5 wt% and less than about 10 wt% relative to the total weight of the first adhesive component 501, such that the first adhesive component 501 can have excellent elasticity at high temperatures, thereby preventing the formation of permeable bubbles BB, and accordingly, the permeable bubbles BB cannot be regenerated after the display device 1 is subjected to an autoclave process and restored to room temperature and atmospheric pressure.

[0090] The adhesive composition that allows the first adhesive component 501 to be invisible in the display device 1 will be described in more detail below by means of experimental examples based on manufacturing examples and comparative examples of embodiments according to the present disclosure.

[0091] <Manufacturing Example 1>

[0092] An adhesive composition is manufactured according to an embodiment of the present disclosure, the adhesive composition comprising 2-ethylhexyl acrylate (2-EHA) represented by Formula 1, 2-hydroxyethyl acrylate (2-HEA) represented by Formula 2, methyl methacrylate represented by Formula 3, isobornyl methacrylate represented by Formula 5, octyl methacrylate represented by Formula 4, and methyl acrylate represented by Formula 6 as acrylic monomers, comprising 2,6-diisopropylphenyl isocyanate (2,6-DIPPI) represented by Formula 7 as a carbamate monomer, and comprising 4-methylbenzophenone represented by Formula 8 and 2,4,6-trimethylbenzophenone represented by Formula 9 as photoinitiators.

[0093] The above components can be identified by pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) analysis.

[0094] The content of some of the above components can also be identified by nuclear magnetic resonance spectroscopy (NMR). In manufacturing example 1, relative to the total weight of the adhesive composition, 2-ethylhexyl acrylate (2-EHA) represented by chemical formula 1 may be 47.26 wt%, 2-hydroxyethyl acrylate (2-HEA) represented by chemical formula 2 may be 25.45 wt%, methyl methacrylate represented by chemical formula 3 may be 2.78 wt%, octyl methacrylate represented by chemical formula 4 may be 15.52 wt%, and 2,6-diisopropylphenyl isocyanate (2,6-DIPPI) represented by chemical formula 7 may be 8.89 wt%.

[0095] <Comparative Example 1>

[0096] An adhesive composition is manufactured comprising 2-ethylhexyl acrylate (2-EHA) represented by Formula 1, octyl methacrylate represented by Formula 4, and isobornyl acrylate represented by Formula 10 as acrylic monomers, and comprising 4-hydroxybenzophenone represented by Formula 11 and irgacure651 (2,2-dimethoxy-1,2-diphenylethyl-1-one) represented by Formula 12 as photoinitiators.

[0097] [Chemical Formula 10]

[0098]

[0099] [Chemical Formula 11]

[0100]

[0101] [Chemical Formula 12]

[0102]

[0103] The above components can be identified by pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) analysis.

[0104] <Comparative Example 2>

[0105] An adhesive composition is manufactured comprising 2-ethylhexyl acrylate (2-EHA) represented by Formula 1, 2-hydroxyethyl acrylate (2-HEA) represented by Formula 2, octyl methacrylate represented by Formula 4, and 2-hydroxyethyl methacrylate represented by Formula 13 as acrylic monomers, and comprising 4-hydroxybenzophenone represented by Formula 11, methyl 4-benzoylbenzoate represented by Formula 14, and irgacure 651 represented by Formula 12 as photoinitiators.

[0106] [Chemical Formula 13]

[0107]

[0108] [Chemical Formula 14]

[0109]

[0110] The above components can be identified by pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) analysis.

[0111] <Comparative Example 3>

[0112] An adhesive composition is prepared comprising 2-ethylhexyl acrylate (2-EHA) represented by Formula 1, methyl methacrylate represented by Formula 3, octyl methacrylate represented by Formula 4, isobornyl methacrylate represented by Formula 5, methyl acrylate represented by Formula 6, lauryl acrylate represented by Formula 15, pentaerythritol triacrylate represented by Formula 16, and 2-ethylhexyl methacrylate represented by Formula 17 as acrylic monomers, and comprising 4-methylbenzophenone represented by Formula 8 and 2,4,6-trimethylbenzophenone represented by Formula 9 as photoinitiators.

[0113] [Chemical Formula 15]

[0114]

[0115] [Chemical Formula 16]

[0116]

[0117] [Chemical Formula 17]

[0118]

[0119] The above components can be identified by pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) analysis.

[0120] The content of some of the above-mentioned components can also be identified by nuclear magnetic resonance spectroscopy (NMR). Regarding the content of some components in Comparative Example 3, relative to the total weight of the adhesive composition, 2-ethylhexyl acrylate (2-EHA) represented by Formula 1 may be 20.58 wt%, 2-ethylhexyl methacrylate represented by Formula 17 may be 60.74 wt%, and methyl methacrylate represented by Formula 3 may be 16.09 wt%.

[0121] Figure 7 and Figure 8 This is a schematic diagram illustrating the creep test and stress relaxation test process. Figure 9This is an example. Figure 7 and Figure 8 The graph shows the results of the creep test. Figure 10 This is an example. Figure 7 and Figure 8 The figure shows the results of the stress relaxation test.

[0122] In the following description, each of the sample SMPs has been manufactured in the shape of a circular plate or coin, having a diameter 'd' of 8 mm and a thickness 't' of 600 μm on the base side. The first sample SMP1 is a sample SMP manufactured using Manufacturing Example 1, the second sample SMP2 is a sample SMP manufactured using Comparative Example 1, the third sample SMP3 is a sample SMP manufactured using Comparative Example 2, and the fourth sample SMP4 is a sample SMP manufactured using Comparative Example 3.

[0123] <Experimental Example 1: Creep Test Conducted at 60℃>

[0124] Creep tests were conducted using samples SMP1, SMP2, SMP3, and SMP4 at 60°C under a shear stress of 2000 Pa for 600 seconds. Figure 9 The strain exhibited when samples SMP (including samples SMP1, SMP2, SMP3, and SMP4) manufactured by Manufacturing Example 1 and Comparative Examples 1 to 3, respectively, were removed after applying a shear stress of 2000 Pa to the sample for 600 seconds is illustrated as a result of Experimental Example 1. In this case, strain can refer to the level of rotation of the sample SMP. For example, when the strain is 100% in this experiment, it means that the sample SMP rotates one revolution, and when the strain is 200%, it means that the sample SMP rotates two revolutions.

[0125] refer to Figure 9 In Experimental Example 1, each of the first and second samples, SMP1 and SMP2, exhibited approximately 100% or less of its maximum strain at the 600-second mark. Specifically, the first sample, SMP1, exhibited approximately 50% of its maximum strain at the 600-second mark, and the second sample, SMP2, exhibited approximately 90% of its maximum strain at the 600-second mark. Meanwhile, in Experimental Example 1, the third sample, SMP3, exhibited approximately 350% to approximately 400% of its maximum strain at the 600-second mark, and the fourth sample, SMP4, exhibited approximately 500% to approximately 550% of its maximum strain at the 600-second mark.

[0126] As a result, among the first to fourth samples SMP1, SMP2, SMP3 and SMP4, when a shear stress of 2000 Pa was applied to the first sample SMP1 manufactured by manufacturing example 1 for 600 seconds, the first sample SMP1 manufactured by manufacturing example 1 showed the smallest amount of maximum strain.

[0127] Experimental Example 1 demonstrates that a low maximum strain minimizes the occurrence of air bubbles (BB) in the display device 1. Specifically, when Experimental Example 1 shows a low maximum strain, this indicates that the adhesive composition has been well cross-linked, and thus well cured. Therefore, the first sample SMP1 manufactured using Manufacturing Example 1, with its minimal maximum strain, can exhibit a high ability to minimize the occurrence of air bubbles (BB).

[0128] Note that the first sample SMP1 cured better at 60°C than the second to fourth samples SMP2, SMP3, and SMP4. In other words, since the first sample SMP1 cured better at 60°C than the second to fourth samples SMP2, SMP3, and SMP4, the first sample SMP1 using the manufacturing example 1 according to the present disclosure can be applied to the first adhesive component 501 to reduce the occurrence of air bubbles (BBs).

[0129] <Experimental Example 2: Stress relaxation test conducted at 60℃>

[0130] Stress relaxation tests were performed using samples SMP1, SMP2, SMP3, and SMP4 (samples 1 through 4) at 60°C. The results of Experimental Example 2 show... Figure 10 middle.

[0131] refer to Figure 10 In Experiment 2, when a shear stress of approximately 3000 Pa to approximately 4000 Pa was applied at approximately 1.2 seconds, the first sample SMP1 exhibited 25% strain. When a shear stress of approximately 4000 Pa to approximately 5000 Pa was applied at approximately 1.2 seconds, the second sample SMP2 exhibited 25% strain. When a shear stress of approximately 2000 Pa to approximately 3000 Pa was applied at approximately 1.2 seconds, the third sample SMP3 exhibited 25% strain. When a shear stress of approximately 1500 Pa to approximately 2500 Pa was applied at approximately 1.2 seconds, the fourth sample SMP4 exhibited 25% strain.

[0132] Experimental Example 2 shows that a shear stress of approximately 3000 Pa or more but less than approximately 4000 Pa is a suitable range for shear stress to minimize the occurrence of air bubbles (BB) in the display device 1. When Experimental Example 2 shows a shear stress of approximately 3000 Pa or more, the flow of the adhesive composition weakens, thereby preventing overflow. Furthermore, when Experimental Example 2 shows a shear stress of approximately 4000 Pa or less, excessive hardening of the adhesive composition can be prevented, thereby exhibiting high adhesion.

[0133] In view of preventing overflow and achieving sufficient adhesion, the first sample SMP1 of Manufacturing Example 1 according to the embodiment of this disclosure, which shows a shear stress of about 3000 Pa and less than about 4000 Pa as shown in Experimental Example 2, can be applied to the first adhesive component 501 to reduce the occurrence of air bubbles BB.

[0134] <Experiment Example 3: Test on the appearance of bubbles after the autoclave process>

[0135] Reference samples were prepared using each adhesive composition of Manufacturing Example 1 and Comparative Examples 1 to 3. Figures 2 to 6 The first adhesive component 501 is described, which attaches the cover window 300 to the polarizing component 200, and observes whether visible bubbles BB are present after the autoclave process.

[0136] As observed in Experiment 3, it was noted that when the first adhesive component 501 was manufactured using Manufacturing Example 1, Comparative Example 2, and Comparative Example 3, the air bubble BB was not visible; however, when the first adhesive component 501 was manufactured using Comparative Example 1, the air bubble BB was visible. Therefore, it was noted that, considering the aspect that the air bubble BB was not visible in Experiment 3, the first adhesive component 501 could be manufactured using Manufacturing Example 1, Comparative Example 2, and Comparative Example 3.

[0137] <Experiment Example 4: Overflow Test>

[0138] Reference samples were prepared using each adhesive composition of Manufacturing Example 1 and Comparative Examples 1 to 3. Figures 2 to 6 The first adhesive component 501 is described, which attaches the cover window 300 to the polarizing component 200, and whether there is overflow of the first adhesive component 501 made of each adhesive composition after the autoclave process.

[0139] Because the first adhesive component 501 manufactured using Comparative Example 2 was not sufficiently cured, overflow was observed, causing partial outflow of the first adhesive component 501. Meanwhile, the first adhesive components 501 manufactured using Manufacturing Example 1, as well as Comparative Examples 1 and 3, were sufficiently cured, and therefore no overflow was observed.

[0140] As observed in Experiment 4, considering the aspect of preventing overflow, the adhesive compositions of Manufacturing Example 1, Comparative Example 1 and Comparative Example 3 can be applied to the first adhesive component 501.

[0141] <Experiment Example 5: Adhesion Test>

[0142] Reference samples were prepared using each adhesive composition of Manufacturing Example 1 and Comparative Examples 1 to 3. Figures 2 to 6The first adhesive component 501 is described, which is used to attach the cover window 300 to the polarizing component 200, and the adhesion of the first adhesive component 501, made from each adhesive composition, is tested after the autoclave process. Specifically, the adhesion between the cover window 300 and the polarizing component 200 is tested using the first adhesive component 501.

[0143] The first adhesive component 501 manufactured using Comparative Example 3 exhibits an adhesion of approximately 800 gf / inch. This adhesion may be too low to be used when attaching the cover window 300 to the polarizing member 200. The first adhesive component 501 manufactured using Manufacturing Example 1, as well as Comparative Examples 1 and 2, exhibits an adhesion of approximately 3400 gf / inch or greater.

[0144] As a result of the adhesion test in Experimental Example 5, considering the aspect of achieving sufficient adhesion, the adhesive compositions of Manufacturing Example 1, Comparative Example 1 and Comparative Example 2 can be applied to the first adhesive component 501.

[0145] In short, when the adhesive composition of Manufacturing Example 1 is used as the first adhesive component 501 in the display device 1 according to the embodiment of this disclosure, even if the display device 1 returns to room temperature and atmospheric pressure after the autoclave process, the bubbles BB can remain invisible. Furthermore, when the adhesive composition of Manufacturing Example 1 is used as the first adhesive component 501, overflow that would cause the first adhesive component 501 to flow out can be prevented in the display device 1, and due to sufficient adhesion, the adhesive targets can be stably adhered to each other through the first adhesive component 501. Moreover, when the adhesive composition of Manufacturing Example 1 is used as the first adhesive component 501, the first adhesive component 501 is well hardened, as demonstrated in creep tests and stress relaxation tests.

[0146] Although embodiments of the present disclosure have been shown and described above, it will be apparent to those skilled in the art that modifications and variations may be made without departing from the spirit and scope of the present disclosure as defined by the appended claims.

Claims

1. A display device, comprising: Display panel; A cover window is provided on the display panel; as well as A first adhesive component is disposed between the display panel and the cover window. The first adhesive component comprises urethane monomers and acrylic monomers. The urethane monomer comprises 2,6-diisopropylphenyl isocyanate in an amount of 5 wt% to 10 wt% relative to the total weight of the first adhesive component, and The total weight of the acrylic monomer relative to the first adhesive component includes: 45 wt% or more and 55 wt% of 2-ethylhexyl acrylate; Methyl methacrylate in amounts greater than 0 wt% and less than 5 wt%; Octyl methacrylate, 10 wt% or more and 20 wt% or less; and 20 wt% or more and 30 wt% of 2-hydroxyethyl acrylate.

2. The display device of claim 1, wherein the first adhesive component further comprises a photoinitiator, and The photoinitiator includes at least one of 4-methylbenzophenone and 2,4,6-trimethylbenzophenone.

3. The display device of claim 1, wherein the adhesion between the first adhesive member and the display panel or the adhesion between the first adhesive member and the cover window is 3400 gf / inch or greater than 3400 gf / inch.

4. The display device of claim 1, wherein the first adhesive component is manufactured as a cylindrical sample having a diameter of 8 mm and a height of 600 μm, and exhibits 100% or less of the maximum strain during a creep test of the cylindrical sample at 60°C for 600 seconds under a shear stress of 2000 Pa.

5. The display device of claim 1, wherein the first adhesive component is manufactured as a cylindrical sample having a diameter of 8 mm and a height of 600 μm, and exhibits a shear stress of more than 3000 Pa and less than 4000 Pa during a stress relaxation test of the cylindrical sample at 60°C with a strain of 25%.

6. The display device of claim 1, wherein a planarized portion positioned on a plane and an edge portion positioned on at least one side of the planarized portion and curved from the planarized portion in the thickness direction are defined in the display device. The display panel and the overlay window are disposed over the planarized portion and the edge portion.

7. The display device of claim 6, wherein the edge portion is configured to surround the planarized portion.

8. The display device of claim 6, further comprising a polarizing member disposed between the display panel and the cover window. The first adhesive component is disposed between the cover window and the polarizing component.

9. The display device of claim 8, further comprising a second adhesive member disposed between the polarizing member and the display panel. The second adhesive component is made of the same material as the first adhesive component.

10. The display device of claim 4, wherein the first adhesive component further comprises a photoinitiator, and The photoinitiator includes at least one of 4-methylbenzophenone and 2,4,6-trimethylbenzophenone.

11. The display device of claim 4, wherein the adhesion between the first adhesive member and the display panel or the adhesion between the adhesive member and the cover window is 3400 gf / inch or greater than 3400 gf / inch.

12. An adhesive component, comprising: Acrylic monomers; Carbamate monomers; and Photoinitiator, The carbamate monomer comprises 2,6-diisopropylphenyl isocyanate in an amount of 5 wt% to 10 wt% relative to the total weight. The acrylic monomers contained, relative to the total weight, comprised: 45 wt% or more and 55 wt% of 2-ethylhexyl acrylate; Methyl methacrylate in amounts greater than 0 wt% and less than 5 wt%; Octyl methacrylate, 10 wt% or more and 20 wt% or less; and 20 wt% or more and 30 wt% of 2-hydroxyethyl acrylate.

13. The adhesive component of claim 12, wherein the photoinitiator comprises at least one of 4-methylbenzophenone and 2,4,6-trimethylbenzophenone.

14. The adhesive component of claim 12, wherein the adhesive component is manufactured as a cylindrical sample having a diameter of 8 mm and a height of 600 μm, and exhibits 100% or less of the maximum strain during a creep test of the cylindrical sample at 60°C for 600 seconds under a shear stress of 2000 Pa.

15. The adhesive component of claim 12, wherein the adhesive component is manufactured as a cylindrical sample having a diameter of 8 mm and a height of 600 μm, and exhibits a shear stress of more than 3000 Pa and less than 4000 Pa during stress relaxation testing of the cylindrical sample at 60°C with 25% strain.

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