Protective film, cover sheet, and method for removing a protective film

Abstract

The application relates to the technical field of display devices, and particularly provides a protective film, a cover plate and a protective film removing method. The protective film comprises a base film layer and an adjusting adhesive layer, and the adjusting adhesive layer is located on one side of the base film layer. At least one side edge of the adjusting adhesive layer is recessed relative to the corresponding edge of the base film layer under preset conditions. The protective film provided by the application can be adjusted according to the conditions of the protective film to make the adjusting adhesive layer shrink when needed, and an angle allowance is formed at the edge of the adjusting adhesive layer and the base film layer to facilitate film tearing, so that the difficulty of removing the protective film is reduced, and the probability of film tearing abnormity during the removal of the protective film is reduced.

Description

Technical Field

[0001] This application belongs to the field of display device technology, and more specifically, relates to a protective film, a cover plate, and a method for removing the protective film. Background Technology

[0002] Flexible display modules are the core components of flexible display panels. To achieve bendable and foldable functionality, display modules have specific requirements regarding thickness and materials; therefore, the thickness of the cover plate used has gradually decreased with technological advancements. As the cover plate thickness decreases, the structure of the protective film attached to and protecting the cover plate also needs improvement to enhance its performance and better suit the thinned cover plate. Summary of the Invention

[0003] This application provides a protective film, a cover plate, and a method for removing the protective film, so as to improve the performance of the protective film to at least a certain extent.

[0004] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, a protective film is provided, comprising a substrate film layer and an adjusting adhesive layer, wherein the adjusting adhesive layer is located on one side of the substrate film layer;

[0005] Under preset conditions, at least one edge of the adjusting adhesive layer is recessed relative to the corresponding edge of the substrate film layer.

[0006] Optionally, the preset condition is that the temperature at the adjustable adhesive layer meets a preset temperature and after meeting the preset temperature.

[0007] Optionally, the preset temperature is not lower than 150°C.

[0008] Optionally, the conditioning adhesive layer includes a conditioning layer and an adhesive layer, wherein the adhesive layer is located on the side of the conditioning layer opposite to the substrate film layer.

[0009] Optionally, the thickness of the adjusting adhesive layer is 15μm-30μm.

[0010] Optionally, the thickness of the adjustment layer is 5μm-10μm.

[0011] Optionally, the thickness of the adhesive layer is 10μm-20μm.

[0012] Optionally, the adjustment layer includes a deformation adjustment layer and an auxiliary adhesive layer, wherein the auxiliary adhesive layer is located on the side of the deformation adjustment layer close to the substrate film layer.

[0013] Optionally, the thickness of the deformation adjustment layer is 3μm-6μm.

[0014] Optionally, the thickness of the auxiliary adhesive layer is 2μm-4μm.

[0015] Optionally, the adhesive layer is a double-sided differential adhesive.

[0016] Optionally, the material of the adjustment layer includes a shape memory polymer material with a modulus of 100-300 MPa.

[0017] Optionally, the shape memory polymer material includes either electro-memory polymer materials or thermo-memory polymer materials.

[0018] Optionally, the material of the substrate film layer includes polyethylene terephthalate.

[0019] Optionally, the material of the conditioning layer may further include doped particles, which may include at least one of carbon black and metal powder.

[0020] Optionally, the radius of the doped particles is in the range of 3nm-5nm.

[0021] Optionally, the ratio of the doped particles to the shape memory polymer material is 0.05‰-0.2‰, where the ratio is a mass ratio or a volume ratio.

[0022] Optionally, under preset conditions, the shrinkage ratio of the adjusting adhesive layer is not less than 5%.

[0023] Optionally, under preset conditions, the shrinkage ratio of the adjusting adhesive layer is not less than 8%.

[0024] Optionally, under preset conditions, the shrinkage ratio of the adjusting adhesive layer is no more than 20%.

[0025] Optionally, under preset conditions, the shrinkage ratio of the adjusting adhesive layer is no more than 12%.

[0026] Optionally, under preset conditions, the shrinkage ratio of the adjusting adhesive layer is 8% to 12%.

[0027] Optionally, the substrate film layer has a first side edge, and the adjusting adhesive layer has a second side edge corresponding to the first side edge;

[0028] Under preset conditions, the projection of the second side edge in the thickness direction of the substrate film layer is located within the projection range of the substrate film layer in the thickness direction.

[0029] Optionally, the substrate film layer further includes a third side edge, and the third side edge is provided with a corner portion at the junction with the first side edge; under preset conditions, the projection of the corner portion in the thickness direction of the substrate film layer does not overlap with the projection of the adjusting adhesive layer in the thickness direction of the substrate film layer.

[0030] Optionally, under preset conditions, there is a gap between the projection of the first side edge in the thickness direction of the substrate film layer and the projection of the second side edge in the thickness direction of the substrate film layer, and the gap is not less than 10 mm.

[0031] Optionally, the spacing is not less than 12mm.

[0032] Optionally, the spacing shall not exceed 20 mm.

[0033] Optionally, the spacing shall not exceed 18 mm.

[0034] Optionally, the spacing ranges from 12mm to 18mm.

[0035] Optionally, under non-preset conditions, the projected outer contour of the substrate film layer in the thickness direction of the substrate film layer coincides with the projected outer contour of the adjusting adhesive layer in the thickness direction of the substrate film layer.

[0036] Under preset conditions, the projection of the adjusting adhesive layer in the thickness direction of the substrate film layer is located within the projection range of the substrate film layer in the thickness direction of the substrate film layer.

[0037] In a second aspect, this application also provides a cover plate, including a cover plate body and a protective film as described in any of the above claims, the protective film being located on at least one side of the cover plate body in the thickness direction.

[0038] Optionally, the number of protective films is at least two, and the protective films are provided on both sides of the cover plate body in the thickness direction.

[0039] In a third aspect, this application also provides a method for removing a protective film, applied to the cover plate described above, the method comprising:

[0040] Under preset conditions, a tensile force is applied to a portion of the side edge of the substrate film layer to tear the protective film off the cover plate body.

[0041] Optionally, it also includes a film-peeling tool for applying the preset conditions to the protective film, and / or for applying tension to the substrate film layer.

[0042] Optionally, the method further includes attaching a film-peeling tool to the substrate film layer.

[0043] The beneficial effects of the protective film, cover plate, and protective film removal method provided in this application are as follows: By adjusting the conditions of the protective film, the morphology of the adjusting adhesive layer in the protective film is changed, thereby causing the adjusting adhesive layer to shrink when needed. At this time, a certain step difference appears between the substrate film layer and the adjusting adhesive layer in the protective film, forming a corner allowance that facilitates tearing, thus reducing the difficulty of tearing the corner. This effectively reduces the difficulty of removing the protective film, achieving the goal of convenient and quick removal of the protective film compared to the cover plate, and reducing the probability of tearing abnormalities during the protective film removal process. For the cover plate and display module, the above-mentioned protective film structure helps to improve the production yield and efficiency of the display module. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art 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.

[0045] Figure 1 This is a schematic diagram of the structure of the protective film provided in the embodiments of this application under non-preset conditions;

[0046] Figure 2 This is a schematic diagram of the structure of the protective film provided in the embodiments of this application under preset conditions;

[0047] Figure 3 for Figure 2 Top view;

[0048] Figure 4 This is another structural schematic diagram of the protective film provided in the embodiments of this application under preset conditions;

[0049] Figure 5 for Figure 4 Enlarged view of the structure of region A in the middle;

[0050] Figure 6 for Figure 4 Top view;

[0051] Figure 7 This is a schematic diagram of the structure of the protective film provided in another embodiment of this application under non-preset conditions;

[0052] Figure 8 for Figure 7 A cross-sectional view of the adjusting adhesive layer in the middle;

[0053] Figure 9 This is a schematic diagram of the structure of the cover plate provided in an embodiment of this application;

[0054] Figure 10This is another structural schematic diagram of the cover plate provided in an embodiment of this application;

[0055] Figure 11 A schematic flowchart illustrating the protective film removal method provided in this application embodiment;

[0056] Figure 12 This is a schematic diagram showing the state of the cover plate when the protective film is removed, as provided in an embodiment of this application.

[0057] The following are the labeling elements in the figure:

[0058] 1. Substrate film layer; 101. First side edge; 102. Third side edge; 103. Corner; 2. Adjusting adhesive layer; 21. Adjusting layer; 211. Doped particles; 2101. Deformation adjusting layer; 2102. Auxiliary adhesive layer; 22. Adhesive layer; 201. Second side edge; 202. Thickened part; 10. Protective film; 100. Cover plate; 20. Cover plate body. Detailed Implementation

[0059] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0060] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0061] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0062] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0063] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0064] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0065] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0066] With the development of display technology, the types of display panels on the market are gradually increasing, and their performance is constantly improving. To meet the personalized needs of different devices, such as foldable products, some display panels need to be thinned. Taking a display module with a flexible cover plate as an example, to meet the needs of foldable products, some modules in the display module need to be thinned to a certain extent, taking the thinning of the flexible cover plate as an example. During the process of thinning the flexible cover plate, the inventors discovered the following problem: as the cover plate thickness decreases, the difficulty of controlling the cover plate warpage gradually increases, especially during the storage and transportation stages. To overcome this problem, the protective film needs to be thickened to balance the warpage of the cover plate and improve the cover plate yield. However, in the production stage, an excessively thick protective film will cause difficulties in the film peeling process, leading to an increased film peeling defect rate, and ultimately affecting the production yield and efficiency of the display module.

[0067] Based on this, this application provides a protective film 10, which is applicable to cover plate 100 and other similar products to help improve the above-mentioned problems.

[0068] Specifically, the protective film 10 includes a substrate film layer 1 and an adjusting adhesive layer 2, with the adjusting adhesive layer 2 located on one side of the substrate film layer 1. Please refer to [link / reference]. Figures 1-3 Under preset conditions, at least one edge of the adhesive layer 2 is recessed relative to the corresponding edge of the substrate film layer 1.

[0069] When using the protective film 10 to protect the corresponding device, take cover plate 100 as an example. The protective film 10 can be attached to the surface of cover plate 100 by adjusting the adhesive layer 2. At this time, the protective film 10 can provide a certain degree of protection to the surface of cover plate 100 to prevent cover plate 100 from being damaged or contaminated by the external environment before use.

[0070] Please see Figure 1 The aforementioned substrate film layer 1 and adjusting adhesive layer 2 are stacked along the thickness direction. The substrate film layer 1 can be adhered to the surface of the corresponding device through the adjusting adhesive layer 2. At this time, the substrate film layer 1 can play a protective role for the device. For example, the substrate film layer 1 can prevent external hard objects from acting on the surface of the protected device, and prevent scratches from appearing on the surface of the device.

[0071] Specifically, the material of the aforementioned substrate film layer 1 includes polyethylene terephthalate (PET). PET has high transparency, high strength, and good barrier properties, which can provide good protection for the cover plate 100 and the like.

[0072] Specifically, the material of the aforementioned adjusting adhesive layer 2 includes shape memory polymers (SMPs). SMPs refer to products with an initial shape. These products, after having their initial conditions changed and fixed under certain conditions, can recover their initial shape under external stimuli (such as heat, electricity, light, chemical induction, etc.).

[0073] In this embodiment, the SMP can recover its initial shape under preset conditions, which manifests as shrinkage relative to the substrate film layer 1. Ultimately, this means that at least one edge of the adjusting adhesive layer 2 is retracted relative to the corresponding edge of the substrate film layer 1.

[0074] When the adjusting adhesive layer 2 shrinks under preset conditions, its edge will shrink relative to the corresponding edge of the substrate film layer 1, causing the edge of the adjusting adhesive layer 2 to be in an inward state relative to the edge of the substrate film layer 1. Please refer to [link to relevant documentation]. Figure 2 At this time, a certain step difference is generated between the edge of the substrate film layer 1 and the edge of the adjusting adhesive layer 2. This step difference can form a starting angle allowance for tearing off the protective film 10, thereby reducing the difficulty of tearing off the protective film 10.

[0075] Under preset conditions, the protective film 10 can reduce the difficulty of removing the corners through the retractable adjustable adhesive layer 2. After forming a corner removal allowance on the protective film 10 that facilitates the application of force, the operator can quickly tear off the protective film 10 by applying pulling force to the corner removal area.

[0076] Of course, considering the transportation and storage of the protective film 10 itself, the protective film 10 can also be provided with a release film that is easy to remove, which is located on the side of the adjusting adhesive layer 2 facing away from the substrate film layer 1. Alternatively, the protective film 10 can be directly processed onto the surface of the protected device (e.g., cover plate 100), in which case the protective film 10 does not need to be provided with the above-mentioned release film structure.

[0077] In this embodiment, the preset conditions for controlling the shrinkage of the adhesive layer 2 are: the temperature at the adhesive layer 2 meets the preset temperature and after the preset temperature is met.

[0078] The preset temperature is no lower than 150℃.

[0079] Specifically, in some embodiments, the aforementioned preset conditions may be adjusting the temperature at adhesive layer 2 to 150°C or 160°C, etc. It is important to note that the temperature must be controlled to not exceed the melting temperature of the relevant film layer and related devices to prevent damage to them.

[0080] By processing the above-mentioned adjusting adhesive layer 2 under the condition of meeting the preset temperature, the adjusting adhesive layer 2 can shrink and recede inward relative to the corresponding substrate film layer 1, so as to more easily form a starting corner for tearing.

[0081] In some embodiments, the shrinkage ratio of the above-mentioned adjusting adhesive layer 2 under preset conditions is not less than 5%; and / or, the shrinkage ratio is not greater than 20%.

[0082] Specifically, the shrinkage ratio can be set to be no less than 8%; and / or, the shrinkage ratio can be no greater than 12%.

[0083] In other words, the shrinkage ratio of the adhesive layer 2 under preset conditions can be controlled within the range of 8% to 12%, and the specific value range can be adjusted according to actual needs.

[0084] For example, the shrinkage ratio of the adhesive layer 2 under preset conditions can be any value among 85%, 9%, 10%, 11%, 12%, etc.

[0085] The following description uses a side edge of the substrate film layer 1 in the extension direction as an example to illustrate the relative state changes of the substrate film layer 1 and the conditioning adhesive layer 2 under non-preset conditions and preset conditions.

[0086] The substrate film layer 1 is defined to have a first side edge 101 at one end in the extension direction. At the same end, the adjusting adhesive layer 2 has a second side edge 201, with the first side edge 101 corresponding to the second side edge 201. Under preset conditions, the adjusting adhesive layer 2 shrinks. At this time, the second side edge 201 will retract inward relative to the first side edge 101 towards the center position as the adjusting adhesive layer 2 shrinks. (See [link to relevant documentation]). Figure 2 At this time, the projection of the second side edge 201 in the thickness direction of the substrate film layer 1 is located within the projection range of the substrate film layer 1 in the thickness direction.

[0087] Specifically, under non-preset conditions, the first side edge 101 and the second side edge 201 in the aforementioned substrate film layer 1 can be arranged exactly opposite each other. In this case, the projected outline of the first side edge 101 in the thickness direction of the substrate film layer 1 coincides with the projected outline of the second side edge 201 in the thickness direction of the substrate film layer 1. Please refer to [link to relevant documentation]. Figure 1 Of course, there are also cases where the size of the substrate film layer 1 is relatively large compared to the size of the adjusting adhesive layer 2. This embodiment does not limit this.

[0088] Non-preset conditions refer to the temperature at the obtained conditioning adhesive layer 2 always being lower than the preset temperature. At this time, the conditioning adhesive layer 2 maintains its initial shape and does not undergo deformation.

[0089] It is important to note that once the adjusting adhesive layer 2 shrinks under the preset conditions, this shrinkage will persist. In other words, even if the temperature at the point where the adjusting adhesive layer 2 has already shrunk gradually decreases below the preset temperature (i.e., the preset temperature condition is no longer met), the adjusting adhesive layer 2 will maintain its shrinkage state and will not revert to its unshrunken state as the temperature decreases. Therefore, all the non-preset conditions mentioned above should be understood as the adjusting adhesive layer 2 not yet shrinking.

[0090] Below, this application embodiment will only describe the structure of the protective film 10 as an integrally cut film. In this case, the shape and size of the substrate film layer 1 and the adjusting adhesive layer 2 in the protective film 10 are consistent, and each side edge is exactly aligned.

[0091] Under non-preset conditions, the projected outer contour of the substrate film layer 1 in the thickness direction coincides exactly with the projected outer contour of the adjusting adhesive layer 2 in the thickness direction of the substrate film layer 1. Under preset conditions, the adjusting adhesive layer 2 shrinks relative to the substrate film layer 1, causing the outer contour of the adjusting adhesive layer 2 to recede inward relative to the outer contour of the substrate film layer 1.

[0092] Please see Figure 3 The projection of the aforementioned adjusting adhesive layer 2 in the thickness direction of the substrate film layer 1 is located within the projection range of the substrate film layer 1 in the thickness direction of the substrate film layer 1. Figure 3 The dashed line in the figure represents the outer contour of the adjusting adhesive layer 2.

[0093] After the adjusting adhesive layer 2 shrinks relative to the substrate film layer 1 and recedes inward to a certain extent, there is a certain gap between the projection contour formed by the first side edge 101 in the thickness direction projection of the substrate film layer 1 and the projection contour formed by the second side edge 201 in the thickness direction projection of the adjusting adhesive layer 2. This gap is d, and its position and size can be found in [reference needed]. Figure 3 .

[0094] In some embodiments, under preset conditions, there is a distance d between the projection of the first side edge 101 in the thickness direction of the substrate film layer 1 and the projection of the second side edge 201 in the thickness direction of the substrate film layer 1, and the distance is not less than 10 mm.

[0095] The aforementioned spacing is the length by which the adhesive layer 2 is recessed relative to the corresponding edge of the substrate film layer 1. Taking the first side edge 101 and the second side edge 201 mentioned above as examples, this spacing is the length by which the second side edge 201 is recessed relative to the first side edge 101.

[0096] Of course, the edge of the adjusting adhesive layer 2 may also recede inward relative to the substrate film layer 1 at other locations on the protective film 10. For example, when the protective film 10 is a rectangular structure with a certain thickness, both the substrate film layer 1 and the adjusting adhesive layer 2 are rectangular. The adjusting adhesive layer 2 will shrink under preset conditions to form a rectangle with a size slightly smaller than the substrate film layer 1. At this time, there is a gap between the four side edges of the substrate film layer 1 and the corresponding side edges of the adjusting adhesive layer 2. Of course, the protective film 10 can also be a rounded rectangle or a strip structure. Correspondingly, the shape and size of the substrate film layer 1 and the adjusting adhesive layer 2 will also be adjusted accordingly. This embodiment does not limit the specific shape and size of the protective film 10.

[0097] In some embodiments, taking the spacing formed between the first side edge 101 and the second side edge 201 as an example, the size of the spacing can be limited to no more than 20 mm, and the size range of the spacing is 10 mm to 20 mm.

[0098] Specifically, the spacing can be limited to no less than 12mm, in which case the spacing range is 12mm-20mm.

[0099] Specifically, the above spacing can be further limited to no more than 18mm. In this case, the spacing can be limited to the range of 12mm-18mm, and its specific value range can be adjusted according to actual needs.

[0100] For example, the spacing can be any value among 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, etc.

[0101] Under normal circumstances, the adjusting adhesive layer 2 should shrink uniformly at all locations under preset conditions to create a tear-off allowance that is easy to handle between the edge of the adjusting adhesive layer 2 and the corresponding edge of the substrate film layer 1. In some special cases, such as when different areas of the adjusting adhesive layer 2 shrink unevenly, please refer to [the relevant documentation]. Figure 4 and Figure 5 When the adhesive layer 2 shrinks under preset conditions, the film layer at its edge may thicken, forming a thickened portion 202.

[0102] At this time, due to the lifting effect of the thickened portion 202, the substrate film layer 1 opposite to the thickened portion 202 in the thickness direction will bend towards the side away from the adjusting adhesive layer 2, and cause the side edge of the substrate film layer 1 adjacent to the thickened portion 202 to shift towards the side away from the adjusting adhesive layer 2. Please refer to Figure 5 .

[0103] If the edge of the substrate film layer 1 near the thickened portion 202 is raised, the step difference between the edge of the substrate film layer 1 and the edge of the adjusting adhesive layer 2 can be further increased, provided that a corner raising margin is formed between the substrate film layer 1 and the adjusting adhesive layer 2, thereby reducing the difficulty of corner raising and ultimately achieving the effect of reducing the difficulty of film tearing.

[0104] Please see Figure 6 The substrate film layer 1 also includes a third side edge 102 that is connected to the first side edge 101. A corner 103 is formed at the junction of the first side edge 101 and the third side edge 102.

[0105] Under non-preset conditions, the projection of the corner 103 formed by the intersection of the first side edge 101 and the third side edge 102 onto the thickness direction of the substrate film layer 1 (that is, the thickness direction of the protective film 10 itself) can coincide with the projection of the adjusting adhesive layer 2 onto the thickness direction of the substrate film layer 1. This means that the projection of the corner 103 falls exactly on the projection outline of the corresponding position of the substrate film layer 1.

[0106] Under preset conditions, the shrinkage of the adjusting adhesive layer 2 causes its projection range to decrease, while the projection position of the corner 103 remains unchanged. This results in the projection of the corner 103 in the thickness direction of the substrate film layer 1 being located outside the projection of the adjusting adhesive layer 2 in the thickness direction of the substrate film layer 1. Please refer to [link to relevant documentation]. Figure 6 At this time, the projection of the corner portion 103 in the thickness direction of the substrate film layer 1 does not overlap with the projection of the adjusting adhesive layer 2 in the thickness direction of the substrate film layer 1, and there is a certain gap between the two.

[0107] After the thickened portion 202 is formed in the adjusting adhesive layer 2, both the first side edge 101 and the third side edge 102 can be raised relative to the adjusting adhesive layer 2, and the corner 103 located at the intersection of the first side edge 101 and the third side edge 102 has the largest raising amplitude.

[0108] When both the first side edge 101 and the second side edge 201 curl up relative to the substrate film layer 1, a local stress concentration area is formed at the intersection (i.e., corner 103), resulting in a larger curling amplitude at corner 103. The bending deformation at corner 103 is greater than that at the first side edge 101 and the second side edge 201. Therefore, the curling at corner 103 can provide a better starting point for removing the protective film 10, making the removal process simpler.

[0109] When the operator needs to remove the protective film 10, the slight lifting of the corner 103 makes it easier for the operator to find the operating position, thus reducing the difficulty of the operation.

[0110] The structure and composition of the above-mentioned conditioning adhesive layer 2 will be described in detail below.

[0111] In some embodiments, the adjusting adhesive layer 2 is a double-layer film, including an adjusting layer 21 and an adhesive layer 22. The adjusting layer 21 is located on one side of the substrate film layer 1, and the adhesive layer 22 is located on the side of the adjusting layer 21 facing away from the substrate film layer 1. Please refer to [link to relevant documentation]. Figure 7 .

[0112] The adhesive layer 22 is used to provide adhesive force to adhere to the surface of the device to be protected, at which time the substrate film layer 1 can play the function of protecting the device.

[0113] In some embodiments, the adhesive layer 22 may be a double-sided differential adhesive.

[0114] Double-sided differential adhesive is an adhesive with different peel forces on both sides, with one side having relatively high adhesion and the other side having relatively low adhesion. In this embodiment, the side of the adhesive layer 22 with lower adhesion is used to contact the device to be protected, while the side with higher adhesion is used to adhere to the adjustment layer 21. This ensures that the adhesive layer 22 can be firmly bonded to the substrate film layer 1 through the adjustment layer 21, and can shrink synchronously with the shrinkage of the adjustment layer 21 under preset conditions, so that the edge of the adjustment adhesive layer 2 can be retracted relative to the corresponding edge of the substrate film layer 1. At the same time, it is more convenient to peel the substrate film layer 1 off the surface of the protected device.

[0115] Specifically, the adhesive force of the adhesive layer 22 facing the adjustment layer 21 is not less than 1000gF / mm, and the adhesive force of the adhesive layer 22 facing away from the adjustment layer 21 is 3gF / mm-20gF / mm.

[0116] In some embodiments, the adhesive layer 22 may include an acrylic adhesive. The specific composition of this type of adhesive has been disclosed in related technologies and will not be repeated here.

[0117] The conditioning layer 21 is located between the adhesive layer 22 and the substrate film layer 1, and the aforementioned shape memory polymer (i.e., SMP, hereinafter referred to as SMP) is distributed within the conditioning layer 21.

[0118] SMP, a type of polymer, can deform and recover under certain conditions. Its mechanism of action is based on the structural characteristics of the stationary and reversible phases within the material, as well as the movement and interaction of molecular chains. SMP can be classified into thermo-induced, electro-induced, photo-induced, and chemiluminescent types according to its deformation and recovery principles.

[0119] The deformation process of SMP materials mainly includes two stages: shape programming (deformation and fixation) and shape recovery. The shape programming stage primarily includes three phases: heating and softening, deformation, and cooling and fixation.

[0120] (1) Softening by heating

[0121] SMP needs to be heated to a specific temperature, which is usually higher than the glass transition temperature or melting point of the material. When the temperature reaches this range, the microscopic Brownian motion of the reversible phase molecular chains in SMP intensifies, the molecular chain segments change from a frozen state to a more free motion state, and the material changes from a glassy state to a rubbery state, exhibiting a certain degree of fluidity, similar to the state of rubber at high temperatures.

[0122] (2) Deformation by applying external force

[0123] When a material is in a softened state, external forces can be applied to it to elongate and orient the molecular chains of the reversible phase, causing the material to deform and form a temporary shape different from its initial shape. For example, an SMP rod can be bent into a specific angle, or an SMP film can be stretched into a specific shape.

[0124] (3) Cooling and fixing

[0125] Under the influence of external force, the material is cooled. During the cooling process, the reversible phase undergoes crystallization or a glass transition, the movement of the molecular chains is frozen again, and the material hardens, thus fixing the deformed shape. At this point, even if the external force is removed, the material can still maintain its deformed shape.

[0126] The shape recovery phase primarily involves a stimulus-triggered process. When a specific external stimulus is applied to the shape-programmed SMP, the material begins to recover its initial shape. At this time, the molecular chains of the reversible phase gradually unorient, returning to their original random coiled state. Simultaneously, the stationary phase maintains the stability of the overall material structure and remembers the initial shape, guiding the molecular chains of the reversible phase to move in the direction of the initial shape. With the movement of the molecular chains, the material macroscopically recovers its initial shape.

[0127] Common stimulation methods include thermal stimulation, electrical stimulation, light stimulation, and chemical stimulation. For example, for thermotropic SMP, when heated to a certain temperature (usually higher than the temperature during shape programming or reaching the material's shape recovery temperature), the molecular structure and interactions within the material change, triggering the shape recovery process. For electrotropic SMP, heat is generated in the material by passing an electric current, thereby reaching the temperature conditions for shape recovery. For phototropic SMP, under ultraviolet or visible light irradiation, photochromic groups in the material undergo photoisomerization reactions, causing changes in the state of the molecular chains, leading to shape recovery.

[0128] Please refer to the structure of the conditioning layer 21 with the above-mentioned SMP material. Figure 8 The modulus of the SMP material is 100-300 MPa, and the material of the adjustment layer 21 includes the aforementioned SMP.

[0129] In some embodiments, the SMP material can be configured as an electro-induced SMP material or a thermo-induced SMP material.

[0130] In order to meet the usage requirements of the protective film 10, in some embodiments, the thickness range of the adhesive layer 2 can be set to 15μm-30μm, and the specific value range can be adjusted according to actual needs.

[0131] For example, the thickness of the adhesive layer 2 can be any value among 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, etc.

[0132] Since the adjusting adhesive layer 2 has a double-layer structure, the thickness of the adjusting layer 21 in the adjusting adhesive layer 2 can be set to a range of 5μm-10μm, and correspondingly, the thickness of the adhesive layer 22 can be set to a range of 10μm-20μm. Please refer to [link / reference]. Figure 7 In the figure, d1 is used to indicate the thickness of the adjustment layer 21, and d2 is used to indicate the thickness of the adhesive layer 22.

[0133] When the thickness of the adjustment layer 21 is 5 μm, the thickness of the adhesive layer 22 can be any value between 10 μm and 20 μm; when the thickness of the adjustment layer 21 is 6 μm, the thickness of the adhesive layer 22 can be any value between 10 μm and 19 μm; when the thickness of the adjustment layer 21 is 7 μm, the thickness of the adhesive layer 22 can be any value between 10 μm and 18 μm; when the thickness of the adjustment layer 21 is 8 μm, the thickness of the adhesive layer 22 can be any value between 10 μm and 17 μm; when the thickness of the adjustment layer 21 is 9 μm, the thickness of the adhesive layer 22 can be any value between 10 μm and 16 μm; when the thickness of the adjustment layer 21 is 10 μm, the thickness of the adhesive layer 22 can be any value between 10 μm and 15 μm.

[0134] In some embodiments, to further ensure that the adjustment layer 21 can be firmly bonded to the substrate film layer 1, the adjustment layer 21 has a double-layer structure, including a deformation adjustment layer 2101 and an auxiliary adhesive layer 2102. Please refer to [link to relevant documentation]. Figure 8 .

[0135] The deformation adjustment layer 2101 includes the shape memory polymer material described above. The auxiliary adhesive layer 2102 is located between the deformation adjustment layer 2101 and the substrate film layer 1, that is, on the side of the deformation adjustment layer 2101 closer to the substrate film layer 1. The auxiliary adhesive layer 2102 is used to achieve adhesion between the deformation adjustment layer 2101 and the substrate film layer 1.

[0136] In this embodiment, the thickness of the deformation adjustment layer 2101 is 3μm-6μm, and the thickness of the auxiliary adhesive layer 2102 is 2μm-4μm. The specific numerical range can be adjusted according to actual needs.

[0137] When the thickness of the deformation adjustment layer 2101 is 3μm, the thickness of the auxiliary adhesive layer 2102 can be any value among 2μm, 3μm, and 4μm; when the thickness of the deformation adjustment layer 2101 is 4μm, the thickness of the auxiliary adhesive layer 2102 can be any value among 2μm, 3μm, and 4μm; when the thickness of the deformation adjustment layer 2101 is 5μm, the thickness of the auxiliary adhesive layer 2102 can be any value among 2μm, 3μm, and 4μm; when the thickness of the deformation adjustment layer 2101 is 6μm, the thickness of the auxiliary adhesive layer 2102 can be any value among 2μm, 3μm, and 4μm.

[0138] In some embodiments, the deformation conditioning layer 2101 with SMP material further includes doped particles 211. The doped particles 211 can be used to improve the conductivity of the deformation conditioning layer 2101. For electro-induced SMPs, the doped particles 211 enable the deformation conditioning layer 2101 to have a certain conductivity, facilitating shape recovery triggered by electrical stimulation of the SMP, rather than solely relying on thermal stimulation. For example, when a current is applied to an SMP doped with carbon black, the current generates heat through the conductive network formed by the carbon black particles, raising the material temperature and triggering shape recovery, thereby increasing the deformation recovery rate of the conditioning adhesive layer 2.

[0139] Of course, the aforementioned doped particles 211 can also improve the mechanical properties of SMP materials.

[0140] Specifically, the doped particles 211 include at least one of carbon black and metal powder. The metal powder may be at least one of copper powder, aluminum powder, iron powder, and nickel powder.

[0141] Of course, other conductive materials such as graphene and carbon nanotubes can also be selected as dopants as needed.

[0142] The radius of the doped particles 211 ranges from 3 nm to 5 nm. This radius range can be understood as the radius of all doped particles 211 meeting this range requirement, or as the average radius of the doped particles 211 meeting this range requirement.

[0143] In this embodiment, please refer to Figure 8 The ratio of doped particles 211 to shape memory polymer material is 0.05‰-0.2‰, and the specific value range can be adjusted according to actual needs. For example, this ratio can be any value among 0.05‰, 0.10‰, 0.15‰, 0.20‰, etc.

[0144] Specifically, the above ratio is a volume ratio. Of course, in other similar embodiments, this ratio can also be a mass ratio.

[0145] For clarity of illustration, Figure 8 The size of the doped particles 211 distributed within the deformation control layer 2101 may have been exaggerated.

[0146] The deformation adjustment layer 2101, containing the aforementioned SMP material and doped particles 211, can adhere to the substrate film 1 at room temperature without deformation. When the deformation adjustment layer 2101 in the protective film 10 is energized, the charge can move within the SMP material and generate heat within the material. When the heat within the deformation adjustment layer 2101 meets a preset condition, the SMP shrinks, causing the auxiliary adhesive layer 2102 and adhesive layer 22, which are bonded to it, to shrink synchronously. Macroscopically, this manifests as the edge of the adjustment adhesive layer 2 shrinking inward relative to the edge of the substrate film 1.

[0147] It is understood that the protective film 10 provided in this application embodiment, by adjusting the conditions of the protective film 10, changes the shape of the adjusting adhesive layer 2 in the protective film 10, so that the adjusting adhesive layer 2 shrinks when needed. At this time, a certain step difference appears between the substrate film layer 1 and the adjusting adhesive layer 2 in the protective film 10, and a corner allowance that is easy to peel off is formed, which reduces the difficulty of peeling off the corner and helps to solve the problem of reverse release when peeling off the film. It can effectively reduce the difficulty of peeling off the protective film 10. When it is necessary to remove the protective film 10 from the surface of the protected item, the operation is more convenient and can greatly reduce the probability of peeling abnormalities during the removal of the protective film 10, so as to achieve the smooth removal of the protective film 10.

[0148] In a second aspect, this application also provides a cover plate 100, please refer to... Figure 9 and Figure 10 .

[0149] The cover plate 100 includes a cover plate body 20 and a protective film 10 as described above, wherein the protective film 10 is located on at least one side of the cover plate body 20 in the thickness direction. The structure and properties of the protective film 10 can be referred to the above description and will not be repeated here.

[0150] Please see Figure 9 A protective film 10 is attached to the upper surface of the cover plate body 20 in the figure; please refer to Figure 10 In the figure, protective films 10 are attached to both the upper and lower surfaces of the cover plate body 20. The protective film 10 is adhered to the surface of the cover plate body 20 by adjusting the adhesive layer 2.

[0151] When protective films 10 are provided on both sides of the cover plate body 20 in the thickness direction, the number of protective films 10 is at least two.

[0152] Generally speaking, the size of the protective film 10 should not be smaller than the size of the corresponding surface of the cover body 20. In this case, there is one and only one protective film 10 on the corresponding surface of the cover body 20.

[0153] Since the cover plate 100 provided in this application embodiment includes the above-mentioned protective film 10, the cover plate 100 has at least the beneficial effects of any one or more of the above-mentioned protective films 10. The specific effects are described in the foregoing embodiments and will not be repeated here.

[0154] When assembling the cover plate body 20 onto the corresponding display module, the protective film 10 attached to at least one side of the surface of the cover plate body 20 needs to be removed.

[0155] In a third aspect, embodiments of this application also provide a method for removing the protective film 10, which is applied to removing the cover plate body 20 and other devices to which the protective film 10 is attached.

[0156] This method includes the following steps:

[0157] Step S10: Under preset conditions, apply tension to a portion of the side edge of the substrate film layer 1 to tear the protective film 10 off the cover plate body 20.

[0158] When removing the cover body 20 or other similar structures with two protective films 10, the two protective films 10 can be removed sequentially, or the protective film 10 located on one side of the cover body 20 can be removed first, and after the cover body 20 has completed the required pretreatment, the protective film 10 located on the other side of the cover body 20 can be removed according to the process requirements.

[0159] The method also includes a film-peeling tool for providing preset conditions to the protective film 10, and / or for applying tension to the substrate film layer 1.

[0160] Please see Figure 11 Step S10 for removing the protective film 10 includes:

[0161] Step S11: Provide preset conditions to the protective film 10 using a film-peeling tool;

[0162] Step S12: Apply tension to the substrate film layer 1 of the protective film 10 using a film-tearing tool to tear the protective film 10 off the cover plate body 20.

[0163] In step S11, the provision of preset conditions to the protective film 10 by the film-tearing tool can be understood as the film-tearing tool being connected to the protective film 10 and forming an electrical circuit, at which time the protective film 10 is in an energized state and can be heated to meet the preset temperature; or, the film-tearing tool releasing heat, at which time the protective film 10 is heated to meet the preset temperature by the heat released by the film-tearing tool.

[0164] In step S12, applying a pulling force to the substrate film layer 1 of the protective film 10 using the film-tearing tool can be understood as the film-tearing tool being able to adhere to the substrate film layer 1 of the protective film 10. Under the action of the adhesive force, the force applied to the film-tearing tool and used to drive the film-tearing tool to move can act on the substrate film layer 1 and pull the substrate film layer 1 to move.

[0165] Specifically, the aforementioned film-tearing tool is a film-tearing roller, the structure of which is existing technology and will not be described in detail here.

[0166] When the protective film 10 is removed from the cover plate body 20, please refer to its shape. Figure 12 It can be seen that at this time, the adjusting adhesive layer 2 recedes inward relative to the substrate film layer 1, and as the protective film 10 is removed, part of the edge of the protective film 10 separates from the surface of the cover plate body 20.

[0167] It should be noted that after the protective film 10 adhering to the surface of the cover plate 100 is removed, the protective film 10 will not have any effect on the cover plate 100, and the adjusting adhesive layer 2 of the protective film 10, especially the adhesive layer 22, will not remain on the surface of the cover plate 100.

[0168] In some embodiments, when the film-tearing tool applies tension to the substrate film layer 1 of the protective film 10, the temperature of the film-tearing tool should be reduced to room temperature to prevent burns to the operator and improve the safety of the operation.

[0169] To facilitate the peeling operation, in some embodiments, a tearing position can be provided on the surface of the substrate film layer 1 facing away from the adjusting adhesive layer 2, and a pulling force can be applied to the tearing position to achieve smooth removal of the protective film 10.

[0170] In some embodiments, as described above, a region located in the first side edge 101 of the substrate film layer 1 or a portion of the substrate film layer 1 adjacent to the first side edge 101 can be torn off.

[0171] Under preset conditions, the first side edge 101 of the substrate film layer 1 can be adjusted accordingly to form a corner allowance in the adhesive layer 2. This corner allowance can provide some convenience for removing the protective film 10. By using a portion of the corner allowance as the tearing position and attaching it to the tearing tool as the starting point for tearing, the difficulty of peeling off the film can be effectively reduced, allowing the protective film 10 to be peeled off smoothly and quickly from the surface of the cover plate body 20.

[0172] Specifically, the tear-off position can be set in the middle of the first side edge 101, or the tear-off position can be set in the corner 103 mentioned above.

[0173] It should be noted that the method also includes attaching the film-peeling tool to the substrate film layer 1 before performing step S10.

[0174] It is understood that the protective film 10 removal method provided in this application embodiment is applicable to cover plates 100 and other similar electronic devices with the protective film 10 attached. This method can change the shape of the adjusting adhesive layer 2 in the protective film 10 by adjusting the conditions of the protective film 10, so that the adjusting adhesive layer 2 shrinks when needed. At this time, a certain step difference appears between the substrate film layer 1 and the adjusting adhesive layer 2 in the protective film 10, and a corner allowance that is easy to peel off is formed, thereby reducing the difficulty of peeling off the corner. This can effectively reduce the difficulty of peeling off the protective film 10, and achieve the purpose of convenient and quick removal of the protective film 10 relative to the cover plate 100, reducing the probability of peeling abnormalities during the removal of the protective film 10.

[0175] For the cover plate 100 and the display module having the cover plate 100, the method for removing the protective film 10 also helps to improve the production yield and efficiency of the display module.

[0176] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A protective film, characterized by, The application relates to a base film layer (1) and an adjusting adhesive layer (2) arranged on one side of the base film layer (1), wherein the adjusting adhesive layer (2) comprises an adjusting layer (21) and a sticking layer (22), the sticking layer (22) is arranged on the side of the adjusting layer (21) away from the base film layer (1), the sticking layer (22) is a double-sided differential force adhesive, and the side with higher bonding force of the sticking layer (22) is used to be attached to the adjusting layer (21). At least one side edge of the adjusting adhesive layer (2) is inwardly retracted relative to the corresponding edge of the base film layer (1) under a preset condition. The preset condition is that the temperature at the adjusting adhesive layer (2) satisfies a preset temperature and after satisfying the preset temperature. The preset temperature is not lower than 150 DEG C.

2. The protective film according to claim 1, characterized by The thickness of the adjusting adhesive layer (2) is 15-30 microns.

3. The protective film according to claim 2, characterized in that, The thickness of the adjusting layer (21) is 5-10 microns.

4. The protective film according to claim 1, characterized by The thickness of the sticking layer (22) is 10-20 microns.

5. The protective film according to claim 1, characterized by The adjusting layer (21) comprises a deformation adjusting layer (2101) and an auxiliary sticking layer (2102), and the auxiliary sticking layer (2102) is arranged on the side of the deformation adjusting layer (2101) close to the base film layer (1).

6. The protective film according to claim 1, characterized by The thickness of the deformation adjusting layer (2101) is 3-6 microns.

7. The protective film according to claim 1, characterized by The thickness of the auxiliary sticking layer (2102) is 2-4 microns.

8. The protective film according to claim 7, characterized in that, The material of the adjusting layer (21) comprises a shape memory high polymer material, and the modulus of the shape memory high polymer material is 100-300 MPa.

9. The protective film according to claim 7, characterized by The shape memory high polymer material comprises any one of an electro-memorized high polymer material and a thermo-memorized high polymer material.

10. The protective film according to claim 1, characterized by The material of the base film layer (1) comprises polyethylene terephthalate.

11. The protective film according to claim 10, characterized in that, The material of the adjusting layer (21) further comprises doped particles (211), and the doped particles (211) comprise at least one of carbon black and metal powder.

12. The protective film according to claim 1, characterized by The radius of the doped particles (211) ranges from 3 nm to 5 nm, all the doped particles (211) satisfy the radius range requirement, or the average radius of all the doped particles (211) satisfies the radius range requirement.

13. The protective film according to claim 10, wherein The ratio of the doped particles (211) to the shape memory high polymer material is 0.05‰-0.2‰, and the ratio is a mass ratio or a volume ratio.

14. The protective film according to claim 13, characterized by Under the preset condition, the shrinkage ratio of the adjusting adhesive layer (2) is not less than 5%.

15. The protective film according to claim 13, wherein Under the preset condition, the shrinkage ratio of the adjusting adhesive layer (2) is not less than 8%.

16. The protective film according to any one of claims 10 to 15, characterized in that, Under the preset condition, the shrinkage ratio of the adjusting adhesive layer (2) is not greater than 20%.

17. The protective film according to any one of claims 10 to 15, characterized in that, Under the preset condition, the shrinkage ratio of the adjusting adhesive layer (2) is not greater than 12%.

18. The protective film according to any one of claims 10 to 15, characterized in that, Under the preset condition, the shrinkage ratio of the adjusting adhesive layer (2) is 8%-12%.

19. The protective film according to any one of claims 10 to 15, characterized in that, The base film layer (1) has a first side edge (101), and the adjusting adhesive layer (2) has a second side edge (201) corresponding to the first side edge (101).

20. The protective film according to any one of claims 10 to 15, characterized in that, Under the preset condition, the projection of the second side edge (201) in the thickness direction of the base film layer (1) is located in the projection range of the base film layer (1) in the thickness direction.

21. The protective film according to claim 1, characterized by ​ ​ 22. The protective film according to claim 21, wherein The substrate film layer (1) further comprises a third side edge (102), and an angle portion (103) is arranged at the joint of the third side edge (102) and the first side edge (101), and under a preset condition, a projection of the angle portion (103) in the thickness direction of the substrate film layer (1) does not overlap with a projection of the adjusting adhesive layer (2) in the thickness direction of the substrate film layer (1).

23. The protective film according to claim 21, characterized by Under a preset condition, a projection of the first side edge (101) in the thickness direction of the substrate film layer (1) has a spacing with a projection of the second side edge (201) in the thickness direction of the substrate film layer (1), and the spacing is not less than 10 mm.

24. The protective film according to claim 23, characterized in that, The spacing is not less than 12 mm.

25. The protective film according to claim 23, characterized by The spacing is not more than 20 mm.

26. The protective film according to claim 23, characterized by The spacing is not more than 18 mm.

27. The protective film according to claim 23, characterized by The spacing ranges from 12 mm to 18 mm.

28. The protective film of claim 1, wherein Under a non-preset condition, an outer contour of a projection of the substrate film layer (1) in the thickness direction of the substrate film layer (1) just coincides with an outer contour of a projection of the adjusting adhesive layer (2) in the thickness direction of the substrate film layer (1); Under a preset condition, a projection of the adjusting adhesive layer (2) in the thickness direction of the substrate film layer (1) is located within the projection range of the substrate film layer (1) in the thickness direction of the substrate film layer (1).

29. A cover plate characterized by Comprise: A cover plate body (20); A protective film (10) as claimed in any one of claims 1-28, the protective film (10) being located on at least one side of the cover plate body (20) in the thickness direction.

30. A protective film removal method characterized by, The method is applied to the cover plate (100) as claimed in claim 29, and the method comprises: Under a preset condition, a pulling force is applied to a part of the side edge of the substrate film layer (1) to tear the protective film (10) from the cover plate body (20).

31. The protective film removal method according to claim 30, wherein Further comprising a film tearing tool, the film tearing tool is used to apply the preset condition to the protective film (10), and / or the film tearing tool is used to apply the pulling force to the substrate film layer (1).

Images