Protective cover plate, flexible display assembly, and foldable electronic device

Abstract

This application provides a protective cover, a flexible display assembly, and a foldable electronic device. The protective cover of this application includes a glass protective layer; a base layer, which is laminated onto the surface of the glass protective layer, wherein the water droplet angle of the base layer facing away from the surface of the glass protective layer is greater than that of the surface of the glass protective layer; and an organic coating, which is laminated onto the surface of the base layer facing away from the glass protective layer, for protecting the glass protective layer. The protective cover provided by the embodiments of this application is less prone to delamination and has a longer service life.

Description

Technical Field

[0001] This application relates to the field of electronics, specifically to a protective cover, a flexible display assembly, and a foldable electronic device. Background Technology

[0002] The development of foldable electronic devices with display functions has led to the emergence of foldable electronic devices. These devices aim to offer a larger display area when in use and a smaller size when portable. Flexible displays are an indispensable display component in foldable electronic devices. Flexible displays are typically protected by protective covers; however, existing protective covers are prone to delamination. Summary of the Invention

[0003] This application provides a protective cover that is less prone to delamination and has a longer service life.

[0004] A first aspect of this application provides a protective cover, which includes:

[0005] Glass protective layer;

[0006] A base coat, wherein the base coat is layered on the surface of the glass protective layer, and the water droplet angle of the base coat away from the surface of the glass protective layer is greater than the water droplet angle of the surface of the glass protective layer; and

[0007] An organic coating is stacked on the surface of the underlayer that is opposite to the glass protective layer, and is used to protect the glass protective layer.

[0008] A second aspect of this application provides a flexible display assembly, characterized in that it comprises:

[0009] A flexible display screen, the flexible display screen having a display surface; and

[0010] The protective cover plate described in the first aspect of this application is stacked on the display surface side of the flexible display screen to protect the flexible display screen.

[0011] A third aspect of this application provides a foldable electronic device, characterized in that it includes:

[0012] Foldable mid-frame; and

[0013] The flexible display assembly described in the second aspect of this application is supported on the foldable mid-frame and folded or flattened under the drive of the foldable mid-frame, wherein the protective cover is further away from the foldable mid-frame than the flexible display.

[0014] In this embodiment, by setting a primer layer between the glass protective layer and the organic coating layer, and ensuring that the droplet angle of the primer layer is larger than that of the glass protective layer, the adhesion between the organic coating layer and the primer layer is greater than the adhesion between the organic coating layer and the glass protective layer. This allows the protective cover to withstand repeated bending without easily delaminating, improving the reliability and lifespan of the protective cover. Furthermore, the organic coating can protect and cushion the glass protective layer, improving its impact and drop resistance. Moreover, it can cover any remaining etching marks on the surface of the glass protective layer. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a protective cover plate according to an embodiment of this application.

[0017] Figure 2 This is a protective cover plate along one embodiment of the present application. Figure 1 A schematic diagram of the structure in the AA direction.

[0018] Figure 3 This is an embodiment of the glass protective layer along... Figure 1 A schematic diagram of the local structure along the AA direction.

[0019] Figure 4 This is another embodiment of the glass protective layer along... Figure 1 A schematic diagram of the structure in the AA direction.

[0020] Figure 5 This is a schematic diagram of the interface interaction between the glass protective layer and the base layer of this application.

[0021] Figure 6 This is another embodiment of the glass protective layer along... Figure 1 A schematic diagram of the local structure along the AA direction.

[0022] Figure 7 This is another embodiment of the glass protective layer along... Figure 1 A schematic diagram of the local structure along the AA direction.

[0023] Figure 8 This is a schematic flowchart of a method for preparing a protective cover plate according to an embodiment of this application.

[0024] Figure 9 This is an optical microscope after the protective cover of Comparative Example 1 has undergone a bending test.

[0025] Figure 10 This is a schematic diagram of the structure of a flexible display assembly according to an embodiment of this application.

[0026] Figure 11 This application describes a flexible display assembly along... Figure 10 A schematic diagram of the cross-section along the BB direction.

[0027] Figure 12 This is a schematic diagram of the structure of a foldable electronic device according to an embodiment of this application in a flattened state.

[0028] Figure 13 This is a schematic diagram of the structure of a foldable electronic device in a folded state according to an embodiment of this application.

[0029] Figure 14 This is a circuit block diagram of an electronic device according to an embodiment of this application.

[0030] Explanation of reference numerals in the attached figures:

[0031] 100 - Protective cover plate, 10 - Glass protective layer, 11 - First protective part, 12 - Bendable part, 13 - Second protective part, 101 - First groove, 14 - Peripheral side, 20 - Undercoat, 21 - Second groove, 30 - Organic coating, 31 - First part, 32 - Second part, 33 - Third part, 34 - Third groove, 300 - Flexible display assembly, 310 - Flexible display, 311 - Display surface, 400 - Foldable electronic device, 410 - Foldable middle frame, 411 - First middle frame, 412 - Hinge, 413 - Second middle frame, 420 - Processor, 430 - Memory, 440 - Camera module. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0033] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0034] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0035] It should be noted that, for ease of explanation, the same reference numerals denote the same components in the embodiments of this application, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0036] With the continuous development of smart electronic devices such as mobile phones, foldable screen electronic devices, such as foldable screen phones, have emerged. The cover plates of foldable screen electronic devices are typically made of materials such as transparent polyimide (CPI) and ultra-thin glass (UTG). While CPI, a plastic material, has good bending performance, it suffers from drawbacks such as yellowing, creases at the bending hinge area, scratches, and insufficient impact resistance. UTG ultra-thin glass, on the other hand, with its advantages of high quality, high transmittance, high hardness, and scratch resistance, has gradually been favored by major mobile phone manufacturers and is being used in foldable screen products. Ultra-thin glass typically refers to glass cover plates with a thickness of less than 0.1mm. Compared to rigid cover plates with a thickness greater than 0.1mm, it inevitably suffers from cracking and poor impact resistance during use. Ultra-thin glass can be protected with an organic coating. However, due to the chemical incompatibility between the inorganic materials of glass and the organic coating, the organic coating adheres directly to the CFG glass, making the protective cover plate prone to delamination.

[0037] Please see Figure 1 and Figure 2 This application provides a protective cover plate 100, which includes a glass protective layer 10, a base layer 20, and an organic coating 30. The base layer 20 is stacked on the surface of the glass protective layer 10, and the water droplet angle of the surface of the base layer 20 facing the organic coating 30 is greater than the water droplet angle (also known as the water contact angle) of the surface of the glass protective layer 10. The organic coating 30 is stacked on the surface of the base layer 20 away from the glass protective layer 10, and is used to protect the glass protective layer 10.

[0038] The protective cover 100 of this application embodiment is applied to a flexible display assembly of a foldable electronic device to protect the flexible display screen of the flexible display assembly. When the protective cover 100 is used to protect the flexible display screen, the glass protective layer 10 is further away from the flexible display screen than the organic coating 30. In other words, the organic coating 30 is closer to the flexible display screen. Foldable electronic devices include at least one of foldable mobile phones, foldable tablets, foldable e-readers, foldable laptops, etc.

[0039] Understandably, the glass protective layer 10, the primer layer 20, and the organic coating layer 30 are stacked sequentially.

[0040] The water droplet angle of the surface of the base coat 20 facing the organic coating 30 is greater than the water droplet angle of the surface of the glass protective layer 10. In other words, the water droplet angle of the surface of the base coat 20 away from the glass protective layer 10 is greater than the water droplet angle of the surface of the glass protective layer 10.

[0041] In this embodiment, by providing a primer layer 20 between the glass protective layer 10 and the organic coating 30, and ensuring that the water droplet angle of the primer layer 20 is greater than that of the glass protective layer 10, the adhesion between the organic coating 30 and the primer layer 20 is greater than the adhesion between the organic coating 30 and the glass protective layer 10. This allows the protective cover plate 100 to withstand repeated bending without easily delaminating, improving the reliability and lifespan of the protective cover plate 100. Furthermore, the organic coating 30 can protect and cushion the glass protective layer 10, improving its impact resistance and drop resistance. Moreover, when etching marks remain on the surface of the glass protective layer 10, the organic coating 30 can cover them.

[0042] Please see Figure 3 In some embodiments, the glass protective layer 10 includes a first protective portion 11, a bendable portion 12, and a second protective portion 13 connected in sequence. The bendable portion 12 is recessed on the surface of the base layer 20 facing the first protective portion 11 facing the base layer 20, and the bendable portion 12 is recessed on the surface of the base layer 20 facing the second protective portion 13.

[0043] Understandably, in this embodiment, the glass protective layer 10 is a center-folded glass (CFG) layer of unequal thickness. In other embodiments, the glass protective layer 10 may also be glass of equal thickness.

[0044] It should be noted that when the protective cover 100 is applied to a foldable electronic device, and the foldable electronic device is folded, the protective cover 100 bends along the position of the bendable portion 12.

[0045] The bendable portion 12 is recessed on the surface of the base layer 20 facing the first protective portion 11 facing the base layer 20, and the bendable portion 12 is recessed on the surface of the second protective portion 13 facing the base layer 20. Understandably, the glass protective layer 10 has a first groove 101 located on its surface facing the base layer 20. The first protective portion 11, the bendable portion 12, and the second protective portion 13 enclose the first groove 101. Understandably, the first groove 101 is located on the bendable portion 12.

[0046] Understandably, the glass protective layer 10 is planar away from the surface of the base layer 20. In other words, the first protective layer is planar away from the surface of the base layer 20, the bendable portion 12 is planar away from the surface of the base layer 20, and the second protective layer is planar away from the surface of the base layer 20.

[0047] Understandably, the thickness of the first protective part 11 is greater than the thickness of the bendable part 12, and the thickness of the second protective part 13 is greater than the thickness of the bendable part 12.

[0048] Understandably, the first protective part 11, the bendable part 12, and the second protective part 13 are different parts of the glass protective layer 10, and the three are an integral structure.

[0049] In this embodiment, the first protective part 11 and the second protective part 13 are relatively thick, which makes the glass protective layer 10 have better impact resistance and drop resistance. The flexible part 12 is relatively thin, which makes the glass protective layer 10 have better bending performance. Thus, the flexible display assembly has both good impact resistance and good bending performance.

[0050] Optionally, along the stacking direction of the glass protective layer 10, the underlayer 20, and the organic coating 30, the thickness of the first protective portion 11 ranges from 60 μm to 240 μm. Specifically, the thickness of the first protective portion 11 can be, but is not limited to, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm, 220 μm, 240 μm, etc. If the thickness of the first protective portion 11 is too thin, the protective cover 100, when applied to the flexible display assembly, reduces the impact resistance and drop resistance of the flexible display assembly; if the thickness of the first protective portion 11 is too thick, it increases the thickness of the flexible display assembly, which is not conducive to the thinning and lightening of the flexible display assembly.

[0051] In the embodiments of this application, when the numerical range a to b is involved, unless otherwise specified, the numerical value can be any value between a and b, including the endpoint value a and the endpoint value b.

[0052] Optionally, along the stacking direction of the glass protective layer 10, the underlayer 20, and the organic coating 30, the thickness of the bendable portion 12 ranges from 10 μm to 40 μm. Specifically, the thickness of the bendable portion 12 can be, but is not limited to, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, etc. If the thickness of the bendable portion 12 is too thin, the protective cover 100, when applied to the flexible display assembly, reduces the impact resistance and drop resistance of the flexible display assembly, as well as its supporting and protective function for the flexible display; if the thickness of the bendable portion 12 is too thick, the bending performance of the protective cover 100 is reduced, which is not conducive to reducing the bending radius of the flexible display assembly.

[0053] Optionally, along the stacking direction of the glass protective layer 10, the underlayer 20, and the organic coating 30, the thickness of the second protective portion 13 ranges from 60 μm to 240 μm. Specifically, the thickness of the second protective portion 13 can be, but is not limited to, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 120 μm, 140 μm, 160 μm, 180 μm, 200 μm, 220 μm, 240 μm, etc. If the thickness of the second protective portion 13 is too thin, the protective cover 100, when applied to the flexible display assembly, reduces the impact resistance and drop resistance of the flexible display assembly; if the thickness of the second protective portion 13 is too thick, it increases the thickness of the flexible display assembly, which is not conducive to the thinning and lightening of the flexible display assembly.

[0054] Please see Figure 4 In some embodiments, the undercoat 20 covers the surface of the glass protective layer 10 facing the organic coating 30 and the peripheral side surface 14 of the glass protective layer 10; the organic coating 30 covers the surface of the undercoat 20 away from the glass protective layer 10 and covers the peripheral side surface 14 of the glass protective layer 10.

[0055] Understandably, the peripheral side 14 of the glass protective layer 10 refers to the surfaces of the glass protective layer 10 that are connected to the surfaces of the glass protective layer 10 facing the organic coating 30 and the surfaces of the glass protective layer 10 that are away from the organic coating 30, respectively.

[0056] Understandably, the base coat 20 covers the entire surface of the glass protective layer 10 facing the organic coating 30 and the entire peripheral side surface 14 of the glass protective layer 10.

[0057] Understandably, the underlayer 20 and organic coating 30 extend outward relative to the glass protective layer 10. In other words, the glass protective layer 10 is recessed relative to the organic coating 30 and the underlayer 20.

[0058] It should be noted that, in this embodiment, both the undercoat 20 and the organic coating 30 cover the peripheral side surface 14 of the glass protective layer 10. In other embodiments, the undercoat 20 and the organic coating 30 may not cover the peripheral side surface 14 of the glass protective layer 10, that is, they may be disposed away from the peripheral side surface 14 of the glass protective layer 10.

[0059] In this embodiment, an organic coating 30 is provided on the peripheral side 14 of the glass protective layer 10, which can better protect the edge portion of the glass protective layer 10 and improve the impact resistance and drop resistance of the glass protective layer 10.

[0060] In some embodiments, the difference between the water droplet angle θ1 of the surface of the undercoat 20 facing the organic coating 30 and the water droplet angle θ2 of the surface of the glass protective layer 10 facing the organic coating 30 is in the range of 30°≤θ1-θ2≤50°. Specifically, θ1-θ2 can be, but is not limited to, 30°, 33°, 35°, 38°, 40°, 42°, 45°, 48°, 50°, etc. If θ1-θ2 is too low, the bonding force between the undercoat 20 and the organic coating 30 is insufficient, which is not conducive to improving the bonding force between the various film layers of the protective cover 100 and increases the probability of delamination during the bending process of the protective cover 100; if θ1-θ2 is too high, a larger amount needs to be applied when preparing the undercoat 20, which is prone to liquid accumulation, affecting the appearance of the undercoat 20, and thus affecting the appearance effect of the protective cover 100.

[0061] In some embodiments, the water droplet angle of the undercoat 20 facing the organic coating 30 ranges from 40° to 60°. Specifically, the water droplet angle of the undercoat 20 facing the organic coating 30 can be, but is not limited to, 40°, 42°, 45°, 48°, 50°, 52°, 55°, 58°, 60°, etc. If the water droplet angle of the undercoat 20 facing the organic coating 30 is too low, the bonding force between the undercoat 20 and the organic coating 30 will be insufficient, which is not conducive to improving the bonding force between the various film layers of the protective cover 100 and increases the probability of delamination during the bending process of the protective cover 100. If the water droplet angle of the undercoat 20 facing the organic coating 30 is too high, a larger amount needs to be applied when preparing the undercoat 20, which is prone to liquid accumulation, affecting the appearance of the undercoat 20 and thus affecting the appearance of the protective cover 100.

[0062] Furthermore, the water droplet angle of the base coat 20 facing the organic coating 30 ranges from 45° to 55°. This allows for a higher bonding strength between the base coat 20 and the organic coating 30, making it less prone to delamination, while also giving the base coat 20 a better appearance.

[0063] In some embodiments, the water droplet angle of the glass protective layer 10 is less than or equal to 30°. Further, the water droplet angle of the glass protective layer 10 is less than or equal to 35°. Even further, the water droplet angle of the glass protective layer 10 is less than or equal to 30°. Even further, the water droplet angle of the glass protective layer 10 is less than or equal to 25°. Even further, the water droplet angle of the glass protective layer 10 is less than or equal to 20°. Even further, the water droplet angle of the glass protective layer 10 is less than or equal to 15°. Even further, the water droplet angle of the glass protective layer 10 is less than or equal to 10°. Even further, the water droplet angle of the glass protective layer 10 is less than or equal to 8°.

[0064] In some embodiments, the thickness of the underlayer 20 is from 1 nm to 1000 nm. Specifically, the thickness of the underlayer 20 can be, but is not limited to, 1 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 80 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1000 nm, etc. If the thickness of the underlayer 20 is too thin, the amount of underlayer 20 will be insufficient, and it may not be able to completely cover the glass protective layer 10, reducing the adhesion between the organic coating 30 and the underlayer 20; if the thickness of the underlayer 20 is too thick, liquid is prone to accumulate during the preparation of the underlayer 20, resulting in poor uniformity of the appearance of the underlayer 20, thereby affecting the appearance of the protective cover plate 100.

[0065] Understandably, the thickness of the underlayment 20 is uniform. The underlayment 20 does not fill the first groove 101 on the surface of the glass protective layer 10 facing the underlayment 20, thereby forming a second groove 21 on the surface of the underlayment 20 away from the surface of the glass protective layer 10. Understandably, the first groove 101 and the second groove 21 are correspondingly arranged. It can also be understood that the first groove 101 and the second groove 21 are stacked.

[0066] Furthermore, the thickness of the underlayer 20 is between 30 nm and 800 nm. This allows for good adhesion between the underlayer 20 and the organic coating 30, while also giving the underlayer 20 a good appearance.

[0067] Furthermore, the thickness of the underlayer 20 is 50nm to 500nm. This allows for good adhesion between the underlayer 20 and the organic coating 30, while also giving the underlayer 20 a good appearance.

[0068] Optionally, the material of the base layer 20 can be, but is not limited to, a silane coupling agent.

[0069] In some embodiments, the underlayer 20 includes at least one of γ-aminopropyltriethoxysilane (KH550), γ-glycidoxypropyltrimethoxysilane (KH560), γ-(methacryloyloxy)propyltrimethoxysilane (KH570), N-(β-aminoethyl)-γ-aminopropyltrimeth(eth)oxysilane (KH792), N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane (DL602), and vinyltrimethoxysilane (DL171).

[0070] Understandably, the bottom layer 20 can be one of the following silane coupling agents: γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimeth(eth)oxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, vinyltrimethoxysilane, etc., or it can be a combination of two or more of these silane coupling agents.

[0071] In this embodiment, a silane coupling agent is used as the underlayer 20. The silane coupling agent can react with the silica of the glass protective layer 10 to form chemical bonds, thereby enabling the underlayer 20 and the glass protective layer 10 to be bonded together by chemical bonds (e.g., ...). Figure 5 (As shown); Furthermore, although the underlayer 20 and the organic coating 30 are bonded by van der Waals forces and hydrogen bonds, the silane coupling agent contains polar groups, giving the underlayer 20 a higher polarity, which can better improve the surface energy of the underlayer 20. Also, the underlayer 20 and the organic coating 30 have a high degree of similarity, resulting in lower interfacial tension. The combined effect of these two factors makes the bonding force between the underlayer 20 and the organic coating 30 greater than the bonding force between the glass protective layer 10 and the organic coating 30. This results in greater bonding force between the various film layers of the protective cover plate 100, allowing it to withstand more bending and reducing the likelihood of delamination.

[0072] Please see Figure 6In some embodiments, the organic coating 30 includes a first part 31, a second part 32, and a third part 33 connected in sequence. The first part 31 covers the first protective part 11, the second part 32 covers the bendable part 12, and the third part 33 covers the second protective part 13. The thickness of the organic coating 30 is uneven, and the surface of the organic coating 30 facing away from the glass protective layer 10 is planar.

[0073] Understandably, the first part 31 is stacked with the first protective part 11, the second part 32 is stacked with the bendable part 12, and the third part 33 is stacked with the second protective part 13.

[0074] Understandably, in this embodiment, the organic coating 30 fills the second groove 21 formed on the side of the underlayer 20 away from the glass protective layer 10.

[0075] It can also be understood that the thickness of the first part 31 is less than the thickness of the second part 32, and the thickness of the third part 33 is less than the thickness of the second part 32.

[0076] It should be noted that Part 31, Part 32 and Part 33 are different parts of the organic coating 30, and the three are an integral structure.

[0077] In this embodiment, the organic coating 30 is designed with uneven thickness, which can fill the second groove 21 on the surface of the underlayer 20 facing the organic coating 30, so that the protective cover 100 has a better appearance. In addition, when the protective cover 100 is applied to the flexible display assembly, it is necessary to use transparent optical adhesive (such as OCA adhesive) to bond the protective cover 100 to the flexible display. The surface of the organic coating 30 facing away from the glass protective layer 10 is flat, which allows for more selection of transparent optical adhesive.

[0078] Please see Figure 7 In other embodiments, the organic coating 30 includes a first part 31, a second part 32, and a third part 33 connected in sequence. The first part 31 covers the first protective part 11, the second part 32 covers the bendable part 12, and the third part 33 covers the second protective part 13. The organic coating 30 has a uniform thickness. The second part 32 is recessed from the surface of the base coat 20 away from the surface of the first part 31 away from the surface of the base coat 20, and the second part 32 is recessed from the surface of the base coat 20 away from the surface of the third part 33 away from the surface of the base coat 20.

[0079] Understandably, in this embodiment, the organic coating 30 forms a third groove 34 on the surface opposite to the glass protective layer 10. The first groove 101, the second groove 21, and the third groove 34 are stacked sequentially.

[0080] In this embodiment, a recess is formed on the surface of the organic coating 30 facing away from the glass protective layer 10 at the positions corresponding to the bendable portion 12 and the second portion 32 of the protective cover 100. Although this reduces the appearance of the protective cover 100, it allows for better control of the thickness of the organic coating 30, resulting in a thinner thickness at the position corresponding to the bendable portion 12 and lower bending stress, thus improving the bending performance of the protective cover 100. Furthermore, this simplifies the process of forming the organic coating 30, ensuring consistent evaporation of the adhesive used to form the organic coating 30 at all locations after application. This results in more even stress distribution on the glass protective layer 10, reducing stress concentration and making the glass protective layer 10 less prone to warping.

[0081] In some embodiments, the thickness of the first part 31 ranges from 0 μm to 100 μm. Specifically, the thickness of the first part 31 can be, but is not limited to, 0 μm, 5 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, etc. If the thickness of the first part 31 is too thick, the bending stress of the protective cover plate 100 will be too large, reducing the bending performance of the protective cover plate 100; if the thickness of the first part 31 is too thin, it will be difficult to cover the etching patterns on the glass protective layer 10, making the protective cover plate 100 prone to wrinkles, light shadows, and other problems.

[0082] Understandably, the thickness of the first part 31 can be 0; in other words, the organic coating 30 can be without the first part 31.

[0083] In some embodiments, the thickness of the second part 32 ranges from 5 μm to 330 μm. Specifically, the thickness of the second part 32 can be, but is not limited to, 5 μm, 10 μm, 20 μm, 30 μm, 50 μm, 80 μm, 100 μm, 130 μm, 150 μm, 180 μm, 200 μm, 230 μm, 250 μm, 280 μm, 300 μm, 330 μm, etc. If the thickness of the second part 32 is too thick, the bending stress of the protective cover plate 100 will be too large, reducing the bending performance of the protective cover plate 100; if the thickness of the second part 32 is too thin, it will be difficult to cover the etching patterns on the glass protective layer 10, making the protective cover plate 100 prone to wrinkles, light shadows, and other problems.

[0084] In some embodiments, the thickness of the third part 33 ranges from 0 μm to 100 μm. Specifically, the thickness of the third part 33 can be, but is not limited to, 0 μm, 5 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, etc. If the thickness of the third part 33 is too thick, the bending stress of the protective cover plate 100 will be too large, reducing the bending performance of the protective cover plate 100; if the thickness of the third part 33 is too thin, it will be difficult to cover the etching patterns on the glass protective layer 10, making the protective cover plate 100 prone to wrinkles, light shadows, and other problems.

[0085] Understandably, the thickness of the third part 33 can be 0; in other words, the organic coating 30 can be without the third part 33.

[0086] In some embodiments, the thickness of the first portion 31 ranges from 3 μm to 80 μm; the thickness of the second portion 32 ranges from 8 μm to 200 μm; and the thickness of the third portion 33 ranges from 3 μm to 80 μm. This allows the protective cover 100 to have lower bending stress and better bending performance, and to better cover the etched patterns on the protective cover 100.

[0087] In other embodiments, the thickness of the first portion 31 ranges from 3 μm to 50 μm; the thickness of the second portion 32 ranges from 8 μm to 150 μm; and the thickness of the third portion 33 ranges from 3 μm to 50 μm. This allows the protective cover 100 to have lower bending stress and better bending performance, and to better cover the etched patterns on the protective cover 100.

[0088] In other embodiments, the thickness of the first portion 31 ranges from 3 μm to 30 μm; the thickness of the second portion 32 ranges from 8 μm to 100 μm; and the thickness of the third portion 33 ranges from 3 μm to 30 μm. This allows the protective cover 100 to have lower bending stress and better bending performance, and to better cover the etched patterns on the protective cover 100.

[0089] Optionally, the organic coating 30 includes at least one of epoxy resin, polyurethane resin, polyester resin, polyurethane acrylic resin, and hydroxyl acrylic resin. Using these materials provides better protection for the glass protective layer 10, improving its impact and drop resistance. Furthermore, these materials have good bending properties, reducing the bending stress on the protective cover 100. Moreover, these materials have good light transmittance, low haze, and low yellowness, resulting in a better appearance for the protective cover 100 and, when applied to flexible display components, enhancing the display performance of the flexible display.

[0090] Optionally, the organic coating 30 has an optical transmittance of greater than or equal to 90% in the visible light region of 380nm to 780nm. Further, the organic coating 30 has an optical transmittance of greater than or equal to 93% in the visible light region of 380nm to 780nm. Even further, the organic coating 30 has an optical transmittance of greater than or equal to 95% in the visible light region of 380nm to 780nm. Specifically, the optical transmittance of the organic coating 30 in the visible light region of 380nm to 780nm can be, but is not limited to, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, etc.

[0091] Optionally, the organic coating 30 has a haze of less than 1% and a yellowness (YI) of less than 2.

[0092] In some embodiments, the energy storage modulus of the organic coating 30 at room temperature ranges from 0.5 MPa to 1000 MPa. Specifically, the energy storage modulus of the organic coating 30 at room temperature can be, but is not limited to, 0.5 MPa, 1 MPa, 10 MPa, 50 MPa, 80 MPa, 100 MPa, 130 MPa, 150 MPa, 180 MPa, 200 MPa, 300 MPa, 400 MPa, 500 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa, 1000 MPa, etc. If the energy storage modulus of the organic coating 30 is too high, its bending performance will be poor, especially with high low-temperature bending stress and low low-temperature creep recovery rate, making it prone to creases. If the energy storage modulus of the organic coating 30 is too low, its deformation will be large. When applied to flexible display components, deformation will occur in both the shear and compression directions when the flexible display component is folded or bent, resulting in a high deformation rate and easy creases. In addition, edge defects are likely to occur during the edge processing of the protective cover 100, reducing the yield of the protective cover 100.

[0093] Understandably, the "room temperature" in this application refers to room temperature conditions, typically 25°C.

[0094] Furthermore, the organic coating 30 has a storage modulus ranging from 0.5 MPa to 500 MPa at room temperature. This allows the protective cover 100 to have lower bending stress, is less prone to creases, and has a higher yield rate.

[0095] Furthermore, the organic coating 30 has a storage modulus ranging from 0.5 MPa to 200 MPa at room temperature. This allows the protective cover 100 to have lower bending stress, is less prone to creases, and has a higher yield rate.

[0096] In some embodiments, the energy storage modulus (low-temperature energy storage modulus) of the organic coating 30 at -20°C ranges from 0.5 MPa to 5000 MPa. Specifically, the energy storage modulus of the organic coating 30 at -20°C can be, but is not limited to, 0.5 MPa, 1 MPa, 10 MPa, 50 MPa, 80 MPa, 100 MPa, 130 MPa, 150 MPa, 180 MPa, 200 MPa, 300 MPa, 400 MPa, 500 MPa, 600 MPa, 700 MPa, 800 MPa, 900 MPa, 1000 MPa, 2000 MPa, 3000 MPa, 4000 MPa, 5000 MPa, etc. If the energy storage modulus of the organic coating 30 is too high, its bending performance will be poor, especially with high low-temperature bending stress and low low-temperature creep recovery rate, making it prone to creases. If the energy storage modulus of the organic coating 30 is too low, its deformation will be large. When applied to flexible display components, deformation will occur in both the shear and compression directions when the flexible display component is folded or bent, resulting in a high deformation rate and easy creases. In addition, edge defects are likely to occur during the edge processing of the protective cover 100, reducing the yield of the protective cover 100.

[0097] Furthermore, the storage modulus of the organic coating 30 at -20°C ranges from 0.5 MPa to 3000 MPa. This allows the protective cover 100 to have lower bending stress, is less prone to creases, and has a higher yield rate.

[0098] Furthermore, the storage modulus of the organic coating 30 at -20°C ranges from 0.5 MPa to 2000 MPa. This allows the protective cover 100 to have lower bending stress, is less prone to creases, and has a higher yield rate.

[0099] In some embodiments, the glass transition temperature of the organic coating 30 ranges from -50°C to 50°C. Specifically, the glass transition temperature of the organic coating 30 can be, but is not limited to, -50°C, -40°C, -30°C, -20°C, -10°C, -0°C, 10°C, 20°C, 30°C, 40°C, 50°C, etc. If the glass transition temperature of the organic coating 30 is too high, the modulus of the organic coating 30 will be too high, resulting in excessive stress when the protective cover 100 is bent, reducing the bending performance of the protective cover 100, making it prone to cracking or creases when bent; if the glass transition temperature of the organic coating 30 is too low, the requirements for the material will be higher.

[0100] The protective cover 100 of this application embodiment can be prepared by the method described in the following embodiments of this application. In addition, it can also be prepared by other methods. The preparation method of this application embodiment is only one or more preparation methods of the protective cover 100 of this application and should not be construed as a limitation on the protective cover 100 provided in the embodiments of this application.

[0101] Please see Figure 8 This application embodiment also provides a method for preparing a protective cover 100, the method comprising:

[0102] S201 provides a glass protective layer 10;

[0103] Optionally, the glass protective layer 10 can be a glass layer of equal thickness or a glass layer of unequal thickness. When the glass protective layer 10 is a glass layer of unequal thickness, one of the two opposing surfaces of the unequal thickness glass layer is a plane, and the other surface has a first groove 101 located in the bendable portion 12.

[0104] Optionally, the glass protective layer 10 is dried after being cleaned (e.g., acid-washed, water-washed, etc.) to remove oil or dust from the surface of the glass protective layer 10.

[0105] S202, forming a primer layer 20 on the surface of the glass protective layer 10; and

[0106] Optionally, a coating process such as spraying, curtain coating or spin coating is used to coat the surface of the glass protective layer 10 with a solution composed of the raw material components of the primer 20, so as to form the primer 20 on the surface of the glass protective layer 10.

[0107] It should be noted that when the glass protective layer 10 is a glass layer of unequal thickness, the underlayer 20 is formed on the surface of the glass protective layer 10 having the first groove 101, and the underlayer 20 is designed with equal thickness, and the underlayer 20 has a second groove 21 on the surface of the glass protective layer 10 away from the surface of the glass protective layer 10.

[0108] S203, an organic coating 30 is formed on the surface of the underlayer 20 that is away from the glass protective layer 10.

[0109] Optionally, a coating process such as spraying, roller coating, scraping, or slot coating is used to coat the surface of the underlayer 20 away from the glass protective layer 10 with the raw material slurry of the organic coating 30, and then cure it (such as photocuring or thermal curing) to obtain the organic coating 30.

[0110] The protective cover 100 of this application will be further described below through specific embodiments.

[0111] Example 1

[0112] The protective cover 100 in this embodiment is prepared by the following steps:

[0113] 1) Provide a glass layer of unequal thickness (i.e., glass protective layer 10), and clean the glass layer of unequal thickness to remove oil or dust from the surface of the glass layer of unequal thickness. The glass layer of unequal thickness has a first groove 101 on one surface. The glass layer of unequal thickness includes a first protective part 11, a bendable part 12 and a second protective part 13 connected in sequence. The thickness of the first protective part 11 and the second protective part 13 is 100 μm. The thickness of the bendable part 12 is 30 μm. The first groove 101 is located in the bendable part 12.

[0114] 2) γ-aminopropyltriethoxysilane (KH550) is sprayed onto the surface of a glass layer of unequal thickness having a first groove 101 to form a primer layer 20. The water droplet angle of the primer layer 20 away from the surface of the glass layer of unequal thickness is measured to be 50°; and

[0115] 3) A stock solution was prepared by mixing polyurethane resin monomer and hexamethylene diisocyanate at a mass ratio of 10:1 and stirring. The prepared stock solution was then applied to the surface of the primer layer 20, away from the unequal thickness glass layer, using a slot coater. The surface was then dried and cured in a tunnel oven to form an organic coating 30. Measurements showed that the organic coating 30 in this embodiment has a room temperature storage modulus of 200 MPa, a low-temperature storage modulus of 2000 MPa at -20°C, and a glass transition temperature (Tg) of 20°C.

[0116] The protective cover 100 of this embodiment was tested and found to have a light transmittance of 95% in the visible light area, a haze of less than 1%, and a yellowness of less than 1.

[0117] The protective cover 100 of this embodiment was tested with a dry cross-cut test and the result was 5B. The protective cover 100 of this embodiment was placed in a water bath and boiled at 100°C for 2 hours (2h). After being removed, it was tested with a cross-cut test and the result was 5B. It was also tested under the same boiling conditions at 100°C for 4 hours. After being removed, it was tested with a cross-cut test and the result was 5B.

[0118] The protective cover 100 of the embodiment was placed in a bending device with a bending radius of 1.0 mm, a low temperature of -20°C, a bending angle of 180°, and a bending radius of 1.0 mm. After 200,000 dynamic bending cycles, it was removed. There was no delamination between the unequal thickness glass layer and the organic coating 30.

[0119] Comparative Example 1

[0120] The protective cover 100 of this comparative example is prepared by the following steps:

[0121] 1) Provide a glass layer of unequal thickness (glass protective layer 10), and clean the glass layer of unequal thickness to remove oil or dust from its surface. One surface of the glass layer of unequal thickness has a groove. The glass layer of unequal thickness includes a first protective portion 11, a bendable portion 12, and a second protective portion 13 connected in sequence. The thickness of the first protective portion 11 and the second protective portion 13 is 100 μm, and the thickness of the bendable portion 12 is 30 μm. The groove is located in the bendable portion 12.

[0122] 2) A stock solution was prepared by mixing polyurethane resin monomer and hexamethylene diisocyanate at a mass ratio of 10:1 and stirring. The prepared stock solution was then applied to the grooved surface of the glass layer of unequal thickness using a slot coater. The surface was then dried and cured in a tunnel oven to form an organic coating 30. Measurements showed that the room temperature storage modulus of the organic coating 30 in this comparative example was 200 MPa, the low-temperature storage modulus at -20°C was 2000 MPa, and the glass transition temperature (Tg) was 20°C.

[0123] The protective cover 100 of this comparative example was tested, and its light transmittance in the visible light area was 95%, haze was less than 1%, and yellowness was less than 1.

[0124] The protective cover plate 100 of the comparative example was tested by dry cross-cut adhesion and the result was 4B. The protective cover plate 100 of the comparative example was placed in a water bath and boiled at 100°C for 2 hours (2h). After taking it out, the organic coating 30 large pieces were peeled off from the glass layer of unequal thickness.

[0125] The protective cover plate 100 of the comparative example was placed in a bending device with a bending radius of 1.0 mm. The temperature was set to -20°C, the bending angle was 180°, and the bending radius was 1.0 mm. After 200,000 dynamic bending cycles, the cover plate was removed. Local wrinkles were observed in the organic coating 30, and local delamination occurred between the organic coating 30 and the glass layers of unequal thickness (e.g., Figure 9 (As shown).

[0126] Please see Figure 10 and Figure 11 This application embodiment also provides a flexible display assembly 300, including: a flexible display 310 and a protective cover plate 100 as described in this application embodiment. The flexible display 310 has a display surface 311; the protective cover plate 100 is stacked on the display surface 311 side of the flexible display 310 to protect the flexible display 310.

[0127] For a detailed description of other aspects of the protective cover, please refer to the description of the corresponding section of the above embodiments, which will not be repeated here.

[0128] Understandably, the display surface 311 is the light-emitting surface of the flexible display screen 310.

[0129] Optionally, the protective cover 100 is bonded to the flexible display screen using transparent optical adhesive.

[0130] Optionally, the flexible display screen 310 may be, but is not limited to, an organic display layer, such as an active matrix organic light-emitting diode (AMOLED).

[0131] Please see Figure 12 and Figure 13 This application also provides a foldable electronic device 400, which includes a foldable mid-frame 410 and a flexible display assembly 300 as described in the above embodiments of this application. The flexible display assembly 300 is supported by the foldable mid-frame 410 and is folded or flattened under the drive of the foldable mid-frame 410. The protective cover 100 is further away from the foldable mid-frame 410 than the flexible display 310.

[0132] The foldable electronic devices according to embodiments of this application include at least one of foldable mobile phones, foldable tablets, foldable e-readers, foldable laptops, etc.

[0133] In some embodiments, the foldable middle frame 410 includes a first middle frame 411, a pivot 412, and a second middle frame 413 sequentially and movably connected; the first middle frame 411 and the second middle frame 413 are respectively rotatable relative to the pivot 412 in a direction that approaches or moves away from each other; the first middle frame 411, the pivot 412, and the second middle frame 413 cooperate with each other to support the flexible display assembly 300; the foldable middle frame 410 has a flattened state (e.g., ...). Figure 12 (as shown) and folded state (as shown) Figure 13 As shown, when the foldable middle frame 410 is in the flattened state, the first middle frame 411, the pivot 412 and the second middle frame 413 form a planar structure; when the foldable middle frame 410 is in the folded state, the first middle frame 411 and the second middle frame 413 overlap.

[0134] Please see also Figure 14 In some embodiments, the foldable electronic device 400 of this application further includes a processor 420 and a memory 430. The processor 420 is electrically connected to the flexible display assembly 300 and the memory 430, respectively. The processor 420 is used to control the flexible display assembly 300 to display, and the memory 430 is used to store the program code required for the processor 420 to run, the program code required to control the flexible display assembly 300, the display content of the flexible display assembly 300, etc.

[0135] Optionally, processor 420 includes one or more general-purpose processors, wherein the general-purpose processor can be any type of device capable of processing electronic instructions, including a central processing unit (CPU), microprocessor, microcontroller, main processor, controller, and ASIC, etc. Processor 420 is used to execute various types of digital storage instructions, such as software or firmware programs stored in memory 430, which enables the computing device to provide a wide range of services.

[0136] Optionally, memory 430 may include volatile memory, such as random access memory (RAM); memory 430 may also include non-volatile memory (NVM), such as read-only memory (ROM), flash memory (FM), hard disk drive (HDD), or solid-state drive (SSD). Memory 430 may also include combinations of the above types of memory 430.

[0137] In some embodiments, the foldable electronic device 400 of this application further includes a camera module 440, which is electrically connected to a processor 420 and is used to take pictures under the control of the processor 420. Optionally, the camera module 440 can be at least one of a front-facing camera module and a rear-facing camera module.

[0138] In this application, the terms "embodiment" and "implementation" mean that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of these phrases in various locations throughout the specification does not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described in this application can be combined with other embodiments. Furthermore, it should be understood that the features, structures, or characteristics described in the various embodiments of this application can be arbitrarily combined to form yet another embodiment that does not depart from the spirit and scope of the technical solution of this application, provided there is no contradiction between them.

[0139] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. A protective cover, characterized in that, include: Glass protective layer; A base coat is layered on the surface of the glass protective layer. The water droplet angle of the base coat facing away from the surface of the glass protective layer is greater than that of the surface of the glass protective layer. The material of the base coat is a silane coupling agent. The difference between the water droplet angle θ1 of the surface of the base coat facing the organic coating and the water droplet angle θ2 of the surface of the glass protective layer facing the organic coating is in the range of 30° ≤ θ1 - θ2 ≤ 50°. An organic coating is stacked on the surface of the underlayer that is opposite to the glass protective layer, and is used to protect the glass protective layer.

2. The protective cover plate according to claim 1, characterized in that, The water droplet angle of the undercoat facing the surface of the organic coating ranges from 40° to 60°.

3. The protective cover plate according to claim 1, characterized in that, The thickness of the underlayer is from 1 nm to 1000 nm, and the underlayer includes at least one of γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimeth(eth)oxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, and vinyltrimethoxysilane.

4. The protective cover plate according to claim 1, characterized in that, The glass protective layer includes a first protective part, a bendable part, and a second protective part connected in sequence. The surface of the bendable part facing the base layer is recessed in the surface of the first protective part facing the base layer, and the surface of the bendable part facing the base layer is recessed in the surface of the second protective part facing the base layer. The undercoat covers the surface of the glass protective layer facing the organic coating and the peripheral side surface of the glass protective layer; the organic coating covers the surface of the undercoat away from the glass protective layer and covers the peripheral side surface of the glass protective layer.

5. The protective cover plate according to claim 4, characterized in that, The organic coating comprises a first part, a second part, and a third part connected in sequence, wherein the first part covers the first protective part, the second part covers the bendable part, and the third part covers the second protective part; The organic coating has an uneven thickness, and the surface of the organic coating facing away from the glass protective layer is flat; or, the organic coating has an even thickness, and the second part of the surface facing away from the base layer is recessed into the first part of the surface facing away from the base layer, and the second part of the surface facing away from the base layer is recessed into the third part of the surface facing away from the base layer.

6. The protective cover plate according to claim 5, characterized in that, The thickness of the first part ranges from 0 μm to 100 μm; the thickness of the second part ranges from 5 μm to 330 μm; and the thickness of the third part ranges from 0 μm to 100 μm.

7. The protective cover plate according to any one of claims 1-6, characterized in that, The energy storage modulus of the organic coating at room temperature ranges from 0.5 MPa to 1000 MPa; the energy storage modulus of the organic coating at -20°C ranges from 0.5 MPa to 5000 MPa.

8. The protective cover plate according to any one of claims 1-6, characterized in that, The glass transition temperature of the organic coating ranges from -50°C to 50°C.

9. A flexible display screen assembly, characterized in that, include: A flexible display screen having a display surface; as well as The protective cover plate according to any one of claims 1-8, wherein the protective cover plate is stacked on the display surface side of the flexible display screen for protecting the flexible display screen.

10. A foldable electronic device, characterized in that, include: Foldable mid-frame; as well as The flexible display assembly of claim 9, wherein the flexible display assembly is supported on the foldable mid-frame and is folded or flattened under the drive of the foldable mid-frame, and the protective cover is further away from the foldable mid-frame than the flexible display.

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