Composite coating, display module and electronic equipment

Abstract

The invention provides a composite coating, a display module and electronic equipment, and relates to the technical field of terminals, the composite coating is applied to the display module, the display module further comprises a cover plate, and the composite coating is arranged on the light emitting side of the cover plate; the composite coating comprises a bonding layer, an anti-impact layer and a hardened coating, the bonding layer is attached to the cover plate, and the anti-impact layer is arranged between the bonding layer and the hardened coating; the anti-impact layer comprises a buffer layer and a force bearing layer, the modulus of the buffer layer ranges from 100 MPa to 1000 MPa, and the elastic modulus of the force bearing layer ranges from 3 GPa to 5 GPa. Therefore, when the composite coating is subjected to large external impact force under the conditions of collision, falling and the like, the composite coating has very good impact resistance.

Description

Technical Field

[0001] The present application relates to the field of terminal technology, and in particular to a composite coating, a display module and an electronic device. Background Art

[0002] With the advancement of technology, touch-screen electronic devices are becoming increasingly popular. For example, users of touch-screen phones rely on touching and clicking on the phone's display to operate it. However, these displays are very fragile and are often damaged by collisions and drops, resulting in high repair costs and a shortened phone lifespan. A broken display can also pose a threat to the user's safety.

[0003] In order to protect the display screen of a mobile phone from damage, a composite coating is usually applied on the display screen as a protective layer to protect the display screen.

[0004] However, most of the current composite coatings only play a major role in wear resistance and scratch resistance, and have very limited effect on improving the impact resistance of display screens, causing the display screens to be fragile when collided or dropped, seriously affecting the performance of electronic devices. Summary of the Invention

[0005] The present application provides a composite coating, a display module and an electronic device. The composite coating improves the impact resistance of the composite coating through the cooperation of the load-bearing layer and the buffer layer therein, thereby improving the ability of the display module to resist external impacts, protecting the display module from damage, and increasing the service life and reliability of the electronic device, reducing maintenance costs, and providing a good user experience.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] In a first aspect, a composite coating for a display module is provided, wherein the display module further comprises a cover plate, and the composite coating is arranged on the light-emitting side of the cover plate; the composite coating comprises an adhesive layer, an impact-resistant layer, and a hardening coating, wherein the adhesive layer is bonded to the cover plate, and the impact-resistant layer is arranged between the adhesive layer and the hardening coating; the impact-resistant layer comprises a buffer layer and a load-bearing layer, wherein the modulus range of the buffer layer comprises 100 MPa to 1000 MPa, and the elastic modulus range of the load-bearing layer comprises 3 GPa to 5 GPa.

[0008] An embodiment of the present application provides a composite coating applied to a display module, wherein the composite coating is bonded to a cover plate via an adhesive layer, and a buffer layer, a load-bearing layer, and a hardened coating are sequentially stacked on the adhesive layer. In this way, when the composite coating is subjected to a large external impact force due to collision, falling, etc., the hardened coating reduces the friction damage of the impact force on the composite coating. Then, the load-bearing layer absorbs part of the impact energy by relying on its slight deformation in the vertical direction, and resists the penetration of sharp objects to a certain extent by destroying the impact object or causing it to deform. Then, the buffer layer absorbs more energy during the deformation process by producing a larger deformation, absorbs and disperses most of the impact energy, and significantly improves the impact resistance of the composite coating.

[0009] In a possible implementation of the first aspect, the tensile strength of the bearing layer is greater than or equal to 50 MPa.

[0010] In this implementation, when the composite coating is subjected to a large external force such as impact or pressure, the load-bearing layer is less likely to rupture.

[0011] In a possible implementation of the first aspect, the ratio of the thickness of the buffer layer to the thickness of the composite coating ranges from 16% to 56%; the ratio of the thickness of the load-bearing layer to the thickness of the composite coating ranges from 15% to 50%.

[0012] In this implementation, since the buffer layer is soft and has a relatively low elastic modulus, it has a good buffering and energy absorption effect. Therefore, the thickness of the buffer layer is set to be relatively thicker to ensure the overall fit of the composite coating. The load-bearing layer is harder than the buffer layer, so the thickness of the load-bearing layer is set to be lower. This can ensure higher rigidity and tensile strength, and better performance as a load-bearing layer, while preventing the overall composite coating from being too hard and affecting the fit.

[0013] In a possible implementation of the first aspect, the load-bearing layer is disposed between the buffer layer and the hardening coating; the buffer layer includes at least one sub-buffer layer, and the load-bearing layer includes at least one sub-load-bearing layer.

[0014] In this implementation method, the load-bearing layer first absorbs part of the impact energy by relying on its slight deformation in the vertical direction, and resists the penetration of sharp objects to a certain extent by destroying the impact object or causing it to deform. Then the buffer layer produces a larger deformation, which can absorb more energy during the deformation process, absorbing and dispersing most of the impact energy, thereby greatly improving the impact resistance of the composite coating.

[0015] In a possible implementation of the first aspect, the buffer layer is disposed between the load-bearing layer and the hardening coating layer; the buffer layer includes at least one sub-buffer layer, and the load-bearing layer includes at least one sub-load-bearing layer.

[0016] In this implementation method, the buffer layer first produces a larger deformation, which can absorb more energy during the deformation process, absorbing and dispersing most of the impact energy. Then the load-bearing layer relies on its slight deformation in the vertical direction to absorb part of the impact energy, and by destroying the impact object or causing it to deform, it can resist the penetration of sharp objects to a certain extent, thereby improving the impact resistance of the composite coating.

[0017] In a possible implementation of the first aspect, the buffer layer includes a sub-buffer layer, and a material of the sub-buffer layer is thermoplastic polyurethane elastomer.

[0018] In this implementation, the thermoplastic polyurethane elastomer is soft and has a low elastic modulus, and has a buffering and energy-absorbing effect, so that the buffer layer has excellent buffering properties.

[0019] In a possible implementation of the first aspect, the buffer layer includes multiple sub-buffer layers, the material of at least one sub-buffer layer includes thermoplastic polyurethane elastomer, and the thickness of the sub-buffer layer composed of thermoplastic polyurethane elastomer accounts for a ratio of greater than or equal to 50% of the thickness of the buffer layer.

[0020] In this implementation, thermoplastic polyurethane elastomers, silicone and silicone gel are soft and have low elastic modulus, and have a buffering and energy-absorbing effect, so that the sub-buffer layer has good buffering properties. However, the thickness of the sub-buffer layer composed of thermoplastic polyurethane elastomer is relatively high, which can make the overall elastic modulus and hardness of the buffer layer appropriate, and the offset printing and feel are better.

[0021] In a possible implementation of the first aspect, when the buffer layer is provided between the load-bearing layer and the hardening coating, at least one sub-buffer layer composed of thermoplastic polyurethane elastomer is bonded to the hardening coating.

[0022] In this implementation, the sub-buffer layer and the hardened coating layer can be well bonded, and the overall performance of the buffer layer can be ensured to be good.

[0023] In a possible implementation of the first aspect, the buffer layer includes at least a first sub-buffer layer and a second sub-buffer layer, the first sub-buffer layer is arranged between the load-bearing layer and the second sub-buffer layer, and the second sub-buffer layer is arranged between the first sub-buffer layer and the hardening coating; the material of the first sub-buffer layer includes any one of silicone and silicone gel, and the material of the second sub-buffer layer includes thermoplastic polyurethane elastomer.

[0024] In this implementation, there are more interfaces in the composite coating, and the elastic modulus of the first sub-buffer layer and the second sub-buffer layer are different. In this way, every time the shock wave passes through an interface, part of the shock wave propagation direction is changed, thereby dispersing the stress. The more interfaces the shock wave passes through, the more the shock wave is dispersed. At the same time, the greater the difference in material properties between the first sub-buffer layer and the second sub-buffer layer, the greater the change in the shock wave direction, the smaller the energy transmitted along the original direction, and the energy is consumed step by step by more layers. In this way, when the composite coating is subjected to a large external impact force, the impact resistance of the composite coating can be further improved.

[0025] In a possible implementation of the first aspect, the buffer layer includes an even number of sub-buffer layers, and the load-bearing layer includes an even number of sub-load-bearing layers, and each sub-buffer layer in the even number of sub-buffer layers is alternately arranged with each sub-load-bearing layer in the even number of sub-load-bearing layers.

[0026] In this implementation, there are more interfaces in the composite coating, and the elastic moduli of the two adjacent layers are also different. In this way, every time the shock wave passes through an interface, part of the shock wave propagation direction is changed, thereby dispersing the stress. The more interfaces it passes through, the more the shock wave is dispersed. At the same time, the material difference between the two adjacent layers is large, the greater the change in the shock wave direction, the smaller the energy transmitted along the original direction, and the energy is consumed step by step by more layers. In this way, when the composite coating is subjected to a large external impact force, the impact resistance of the composite coating can be further improved.

[0027] In a possible implementation of the first aspect, the buffer layer includes an odd number of sub-buffer layers, and the load-bearing layer includes an even number of sub-load-bearing layers, and one sub-buffer layer is disposed between two adjacent sub-load-bearing layers.

[0028] In this implementation, there are more interfaces in the composite coating, and the elastic moduli of the two adjacent layers are also different. In this way, every time the shock wave passes through an interface, part of the shock wave propagation direction is changed, thereby dispersing the stress. The more interfaces it passes through, the more the shock wave is dispersed. At the same time, the material difference between the two adjacent layers is large, the greater the change in the shock wave direction, the smaller the energy transmitted along the original direction, and the energy is consumed step by step by more layers. In this way, when the composite coating is subjected to a large external impact force, the impact resistance of the composite coating can be further improved.

[0029] In a possible implementation of the first aspect, the buffer layer includes an even number of sub-buffer layers, and the load-bearing layer includes an odd number of sub-load-bearing layers, and one sub-load-bearing layer is disposed between two adjacent sub-buffer layers.

[0030] In this implementation, there are more interfaces in the composite coating, and the elastic moduli of the two adjacent layers are also different. In this way, every time the shock wave passes through an interface, part of the shock wave propagation direction is changed, thereby dispersing the stress. The more interfaces it passes through, the more the shock wave is dispersed. At the same time, the material difference between the two adjacent layers is large, the greater the change in the shock wave direction, the smaller the energy transmitted along the original direction, and the energy is consumed step by step by more layers. In this way, when the composite coating is subjected to a large external impact force, the impact resistance of the composite coating can be further improved.

[0031] In a possible implementation of the first aspect, the material of at least one sub-buffer layer includes thermoplastic polyurethane elastomer, and the ratio of the thickness of the sub-buffer layer composed of thermoplastic polyurethane elastomer to the thickness of the buffer layer is greater than or equal to 50%; at least one sub-buffer layer composed of thermoplastic polyurethane elastomer is bonded to the hardened coating.

[0032] In this implementation, the overall elastic modulus and hardness of the buffer layer are appropriate, and the offset printing and feel are relatively good. In addition, the sub-buffer layer can be well fitted with the hardened coating, and the overall performance of the buffer layer is ensured to be good.

[0033] In a possible implementation manner of the first aspect, the material of the sub-load-bearing layer includes any one of polyethylene terephthalate, polycarbonate, polyimide, and polysulfone.

[0034] In this implementation, the load-bearing layer has higher rigidity and is not so hard as a whole, which does not affect the fit. It also has better performance as a load-bearing layer and is simple and easy to implement.

[0035] In a possible implementation of the first aspect, the buffering energy absorption rate of the composite coating is greater than 25%; and / or the dynamic friction coefficient of the composite coating is less than or equal to 0.1; and / or the impact energy range that the composite coating can withstand includes 0.2J to 1J; and / or the haze of the composite coating is less than or equal to 2%; and / or the light transmittance of the composite coating is greater than 85%.

[0036] In this implementation, the composite coating has good impact resistance and strong wear resistance, and does not affect the display effect of the display screen.

[0037] In a possible implementation of the first aspect, the material of the hardened coating includes any one of acrylic resin, siloxane, silicon oxide, titanium oxide and aluminum oxide; and the ratio of the thickness of the hardened coating to the thickness of the composite coating ranges from 1% to 3%.

[0038] In this implementation, the hardened coating can enhance the hardness, wear resistance and scratch resistance of the composite coating, reduce the friction damage of the impact object to the composite coating, and ensure the surface feel, and it is simple and easy to implement.

[0039] In a possible implementation of the first aspect, the material of the adhesive layer includes any one of silicone, silicone gel, optical adhesive and polyurethane; the ratio of the thickness of the adhesive layer to the thickness of the composite coating ranges from 10% to 16%.

[0040] In this implementation, the adhesive layer mainly serves to bond the impact-resistant layer to the cover plate, and also plays a certain role in buffering and absorbing energy, and is simple and easy to implement.

[0041] In a second aspect, a display module is provided, comprising a display screen, a cover plate, and a composite coating as in the first aspect or any possible implementation of the first aspect, wherein the cover plate is arranged on the light-emitting side of the display screen, and the composite coating is arranged on the side of the cover plate away from the display screen.

[0042] An embodiment of the present application provides a display module. When the display module is accidentally collided or dropped, the composite coating in the display module can effectively absorb the impact force generated by the collision or drop, thereby greatly improving the ability of the display module to resist external impacts and protecting the display module from damage.

[0043] In a third aspect, an electronic device is provided, comprising a display module as in the second aspect or any possible implementation of the second aspect.

[0044] The embodiments of the present application provide an electronic device, which has an extended service life, greatly improved reliability, reduced maintenance costs, ensured user safety, and good user experience.

[0045] An embodiment of the present application provides a composite coating, which is bonded to a cover plate via an adhesive layer, and a buffer layer, a load-bearing layer, and a hardened coating are provided on the adhesive layer. In this way, when the composite coating is subjected to a large external impact force due to collision, falling, etc., the hardened coating reduces the friction damage to the composite coating caused by the impact force. The load-bearing layer absorbs part of the impact energy by relying on its slight deformation in the vertical direction, and resists the penetration of sharp objects to a certain extent by destroying the impact object or causing it to deform. The buffer layer can absorb more energy during the deformation process by producing a large deformation, and absorbs and disperses most of the impact energy. Therefore, the cooperation between the load-bearing layer and the buffer layer significantly improves the impact resistance of the composite coating, thereby greatly improving the ability of the display screen in the electronic device using the composite coating to resist external impact, protecting the display screen from damage, and effectively extending the service life of the electronic device, greatly improving reliability, reducing maintenance costs, and ensuring user safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the overall structure of an electronic device provided in an embodiment of the present application;

[0047] Figure 2 for Figure 1 Schematic diagram of the disassembled structure of the electronic device;

[0048] Figure 3 A schematic diagram of the structure of a display screen and a cover provided for related technology;

[0049] Figure 4 A schematic structural diagram of a composite coating, display screen, and cover provided for related technologies;

[0050] Figure 5 A schematic structural diagram of the first composite coating provided in an embodiment of the present application;

[0051] Figure 6 A schematic structural diagram of a composite coating prepolymer provided in an embodiment of the present application;

[0052] Figure 7 for Figure 6 Preparation process flow chart of composite coating prepolymer;

[0053] Figure 8 This is a diagram showing the stress effect of the composite coating provided in an embodiment of the present application;

[0054] Figure 9 A schematic structural diagram of a second composite coating provided in an embodiment of the present application;

[0055] Figure 10 To have Figure 9 Flow chart of the preparation process of composite coating prepolymer for composite coating;

[0056] Figure 11 A schematic structural diagram of a third composite coating provided in an embodiment of the present application;

[0057] Figure 12 To have Figure 11 Flow chart of the preparation process of composite coating prepolymer for composite coating;

[0058] Figure 13 A schematic structural diagram of a fourth composite coating provided in an embodiment of the present application;

[0059] Figure 14 To have Figure 13 Flow chart of the preparation process of composite coating prepolymer for composite coating;

[0060] Figure 15 A schematic structural diagram of a fifth composite coating provided in an embodiment of the present application;

[0061] Figure 16 A schematic structural diagram of a sixth composite coating provided in an embodiment of the present application;

[0062] Figure 17A schematic structural diagram of a seventh composite coating provided in an embodiment of the present application;

[0063] Figure 18 To have Figure 17 Flow chart of the preparation process of composite coating prepolymer for composite coating;

[0064] Figure 19 A schematic structural diagram of an eighth composite coating provided in an embodiment of the present application;

[0065] Figure 20 A schematic structural diagram of a ninth composite coating provided in an embodiment of the present application;

[0066] Figure 21 A schematic structural diagram of a tenth composite coating provided in an embodiment of the present application;

[0067] Figure 22 A schematic structural diagram of an eleventh composite coating provided in an embodiment of the present application;

[0068] Figure 23 A schematic structural diagram of a twelfth composite coating provided in an embodiment of the present application;

[0069] Figure 24 A schematic structural diagram of a thirteenth composite coating provided in an embodiment of the present application;

[0070] Figure 25 Schematic diagram of test points for impact resistance testing of the composite coating provided in an embodiment of the present application.

[0071] Reference numerals:

[0072] 01-mobile phone; 100-display screen; 101-middle frame; 102-back cover; 103-circuit board assembly; 1031-main circuit board; 1032-electronic components; 104-battery; 105-cover plate; 02-composite coating; 03-composite coating preparation; 1-adhesive layer; 2-impact resistant layer; 3-hardening coating; 4-buffer layer; 5-load-bearing layer; 41-first sub-buffer layer; 42-second sub-buffer layer; 51-first sub-load-bearing layer; 52-second sub-load-bearing layer; 10-first protective film; 11-second protective film; 1051-glass cover plate; 13-anti-fingerprint layer. DETAILED DESCRIPTION

[0073] The following is a clear and detailed description of the technical solutions in the embodiments of the present application, with reference to the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " represents the meaning of "or." For example, A / B can represent A or B. "and / or" in the text is merely a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone.

[0074] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of this application, unless otherwise specified, "multiple" means two or more. "At least one" means one or more.

[0075] First, some of the terms used in the embodiments of the present application are explained so that those skilled in the art can better understand them.

[0076] 1. Anti-fingerprint (AF) layer

[0077] The anti-fingerprint layer uses a special coating material that can effectively absorb the oil and sweat left by fingerprints, making the traces left by fingerprints very faint. It can also prevent the traces left by fingerprints from being discovered and copied by others, thereby improving the security and accuracy of fingerprint recognition.

[0078] 2. Dynamic friction coefficient

[0079] The coefficient of kinetic friction is the ratio of friction to normal pressure when two objects in contact are in relative motion. When the objects are in horizontal motion, the normal pressure equals gravity. The coefficient of kinetic friction of a hard particle layer is an important parameter for measuring the frictional performance of that layer under relative motion. The coefficient of kinetic friction varies between objects of different materials. For example, the rougher the object, the greater the coefficient of kinetic friction.

[0080] 3. 2D display

[0081] A 2D display is one where the display surface (more precisely, the glass cover above the display) is completely flat. For example, the display surface is parallel to the frame, or the display is enclosed by the frame (the frame is slightly higher than the display, and the glass cover is slightly lower than the frame).

[0082] 4. 2.5D display

[0083] A 2.5D display, compared to a 2D display, features a glass cover slightly higher than the frame, with curved edges. From the side, it appears to float above the phone's surface, like a water droplet. This curvature eliminates the sharp edges between the glass cover and the midframe, creating a smooth, rounded feel when your finger swipes across the edge. It also uses light refraction to create the illusion of a narrower bezel.

[0084] 5. 3D display

[0085] A 3D display screen refers to a display screen with significantly curved side bezels, creating a 3D curved visual effect. It can display black edges on the screen that are invisible from the front, visually making the bezel appear narrower. The 3D display screen can also allow the side screens to work independently to display notification messages or shortcut icons.

[0086] 6. Elastic modulus

[0087] Elastic modulus refers to the positive proportional relationship between stress and strain of a material during the elastic deformation stage (i.e., it conforms to Hooke's law), and its proportional coefficient is called the elastic modulus.

[0088] 7. Buffering

[0089] Cushioning refers to the ability of a material to absorb and disperse the energy when it is impacted or pressurized, thereby reducing the impact on the display.

[0090] 8. Mohs hardness

[0091] Mohs hardness is a standard for indicating the hardness of a material. It involves scratching the surface of a test material with a pyramidal diamond needle using a scratching method and measuring the depth of the scratch. The depth of the scratch is the Mohs hardness.

[0092] 9. Vickers hardness

[0093] Vickers hardness is a standard for expressing the hardness of materials. It refers to using a diamond right pyramid indenter with an angle of 136° between the relative surfaces to press into the surface of the tested material under a specified load. After maintaining the load for a certain period of time, the load is removed and the diagonal length of the indentation is measured. The surface area of ​​the indentation is then calculated. The average pressure on the indentation surface area is the Vickers hardness value of the tested material, represented by the symbol HV.

[0094] 10. Tensile strength

[0095] Tensile strength refers to the critical value of the material's transition from uniform plastic deformation to local concentrated plastic deformation. It is also the material's maximum bearing capacity under static tension, that is, the resistance to the material's maximum uniform plastic deformation.

[0096] Before the tensile specimen is subjected to the maximum tensile stress, the deformation is uniform and consistent, but after exceeding the maximum tensile stress, the material begins to neck, that is, concentrated deformation occurs. For brittle materials with no (or very little) uniform plastic deformation, it reflects the material's fracture resistance.

[0097] 11. Refractive Index

[0098] Refractive index is a fundamental physical property of materials, defined as the ratio of the speed of light in a vacuum to the speed of light in the material.

[0099] 12. Buffer energy absorption rate

[0100] Cushioning energy absorption rate refers to the ability of the composite coating to absorb and disperse energy when it is impacted.

[0101] The above is a brief introduction to the nouns involved in the embodiments of this application, and no further details will be given below.

[0102] In order to facilitate understanding of the embodiments of the present application, the application background of the present application is first introduced below.

[0103] In modern life, mobile phones and other electronic devices play an increasingly important role and are becoming one of the necessities of people's lives. The embodiments of the present application do not impose any restrictions on the specific types of electronic devices. In some embodiments, the electronic devices of the present application may include mobile phones, laptops, wearable devices (such as smart bracelets, smart watches, headphones, etc.), tablet computers, laptop computers, handheld computers, ultra-mobile personal computers (UMPCs), cellular phones, personal digital assistants (PDAs), augmented reality (AR) and virtual reality (VR) devices, and other Internet of Things (IoT) devices, in-vehicle electronic devices, and may also be televisions, large screens, printers, projectors, and other devices.

[0104] The embodiments of the present application do not limit the specific form of the electronic device. For the convenience of description, the following description will first be given by taking a mobile phone as an example.

[0105] Please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of a mobile phone 01 applicable to some embodiments of the present application. Figure 2 for Figure 1 The disassembly diagram of the mobile phone 01 is shown in FIG. Figure 1 and Figure 2The mobile phone 01 shown is described by taking a tablet phone as an example. In other embodiments, it can also be other types of mobile phones, such as a foldable mobile phone.

[0106] exist Figure 1 and Figure 2 In the example of FIG, the mobile phone 01 may include a display screen 100, a middle frame 101, a rear shell 102, a circuit board assembly 103 and a battery 104. It is understood that, Figure 1 and Figure 2 The following figures and the related drawings only schematically illustrate some components of the mobile phone 01, and the actual shape, size, position and structure of these components are not affected by Figure 1 and Figure 2 and the limitations of the accompanying drawings below.

[0107] like Figure 1 and Figure 2 As shown, the display screen 100 is located on one side of the middle frame 101 and can be used to display images, videos, etc. The display screen 100 can include any one of a liquid crystal display (LCD), an organic light emitting diode (OLED) display screen, a sub-millimeter light emitting diode (Mini LED) display screen, a micro light emitting diode (MicroLED) display screen, etc.

[0108] In addition, the display screen 100 can also be a folding screen, which depends on the actual application.

[0109] refer to Figure 2 As shown, the back cover 102 is disposed on a side of the middle frame 101 away from the display screen 100, and the space between the back cover 102 and the middle frame 101 forms an internal storage space for the mobile phone 01. The internal storage space can accommodate the circuit board assembly 103 and the battery 104. The battery 104 can be used to provide power to the mobile phone 01, such as the display screen 100 and the circuit board assembly 103.

[0110] like Figure 2 As shown, the circuit board assembly 103 includes a main circuit board 1031 and electronic components 1032 , etc. The main circuit board 1031 can be used to carry the electronic components 1032 and perform signal interaction with the electronic components 1032 . Figure 2 The following description is given by taking the circuit board assembly 103 including two electronic components 1032 as an example. Of course, the number of electronic components 1032 is not limited to two, and the specific number depends on actual application.

[0111] In applications, the main circuit board 1031 may include printed circuit boards (PCBs), flexible printed circuits (FPCs), etc.

[0112] The electronic components 1032 may include, but are not limited to, chips, resistors, capacitors, inductors, potentiometers, electron tubes, heat sinks, electromechanical components, connectors, discrete semiconductors, sensors, power supplies, switches, micro motors, electronic transformers, relays, subscriber identity modules (SIM) cards, etc.

[0113] Please refer to Figure 2 The mobile phone 01 further includes a cover plate 105, which can be stacked with the display screen 100 and is mainly used to protect the display screen 100 and prevent dust, and the cover plate 105 can also be fixed on the frame.

[0114] In practice, the cover plate can be made of glass, such as ordinary glass or other glass. Other glass here refers to a type of glass with special materials and functions, such as glass-ceramic, that is different from ordinary glass. Since the cover plate 105 directly covers the display screen 100, in order to avoid affecting the normal display of the display screen 100, the cover plate 105 is preferably made of translucent glass. In this case, the cover plate 105 is a translucent glass cover plate.

[0115] Will Figure 2 The display screen 100 and the cover plate 105 are cut along the cutting line F1F2 to obtain Figure 3 A cross-sectional view of the display screen 100 and the cover plate 105 is shown.

[0116] In the related art, the display screen 100 is often subjected to a large impact force when colliding or falling, resulting in damage. This makes the display screen 100 one of the most fragile parts of the mobile phone 01 and one of the parts with the highest repair probability and cost. It will also greatly reduce the service life of the mobile phone 01 and may threaten the user's safety due to the broken display screen 100.

[0117] In order to solve the above problems, Figure 4 As shown, the related art generally adopts the method of applying a composite coating 02 on the cover plate 105 to form a protective layer, thereby protecting the cover plate 105 from being scratched, nicked, broken, etc. as much as possible through the protective layer.

[0118] However, most current protective layers only play a role in wear resistance and scratch resistance, and have very limited effect on improving the impact resistance of the display screen 100. As a result, the display screen 100 is still prone to breakage when it collides or falls, which leads to a poor user experience.

[0119] The above only introduces the content related to the invention. The rest of the content can be obtained by referring to the relevant technology and will not be described in detail here.

[0120] Please refer to the following Figures 5 to 24 , a detailed introduction is given to the composite coatings 02 of various structures provided in the embodiments of the present application.

[0121] 1. Case 1

[0122] Example 1 (reference Figures 5 to 10 ):

[0123] As an example, Figure 5 As shown, the composite coating 02 provided in the embodiment of the present application is provided on the cover plate of the display screen of the display module in the electronic device.

[0124] Composite coating 02 includes: adhesive layer 1, impact resistant layer 2 and hardening coating 3, adhesive layer 1 and cover plate ( Figure 5 The impact-resistant layer 2 is arranged between the adhesive layer 1 and the hardening coating 3 (not shown).

[0125] The impact-resistant layer 2 includes a buffer layer 4 and a load-bearing layer 5. The buffer layer 4 is arranged between the adhesive layer 1 and the load-bearing layer 5, and the load-bearing layer 5 is arranged between the buffer layer 4 and the hardened coating 3. The material of the buffer layer 4 is thermoplastic polyurethane (TPU). The elastic modulus of the buffer layer 4 ranges from 100MPa to 1000MPa, and the elastic modulus of the load-bearing layer 5 ranges from 3GPa to 5GPa.

[0126] It should be understood that thermoplastic polyurethane elastomer has a buffering and energy-absorbing effect. It is inherently soft and has a low elastic modulus (for example, an elastic modulus range of 100MPa to 1000MPa), thus having excellent cushioning properties. The resulting cushioning layer 4 also has high cushioning properties. Therefore, when the display screen is subjected to significant impact or pressure due to collisions, falls, etc., the composite coating 02 includes a cushioning layer 4 made of a material with buffering and energy-absorbing properties. This cushioning layer 4 can significantly deform when subjected to impact or pressure, and can absorb a significant amount of energy during this deformation process, thereby absorbing and dissipating the vast majority of the impact energy, significantly reducing the impact of external impact forces on the display screen.

[0127] Nowadays, with the development of science and technology, touch screen (touch panel, TP) is the most widely used display screen. When the display screen is a touch screen, the elastic modulus of the buffer layer 4 is more important, because if the elastic modulus is too high, the cushioning property of the buffer layer 4 will be weaker, but if the elastic modulus is too low, the composite coating 02 will be softer as a whole, and the nail mark problem will be more serious. Therefore, the elastic modulus of the buffer layer 4 is set in the range of 100MPa to 1000MPa in the embodiment of the present application. When used to protect the touch screen, the cushioning property is very good, and it will not be soft as a whole, which effectively improves the nail mark problem. Exemplarily, the elastic modulus of the buffer layer 4 can be 100MPa, 200MPa, 400MPa, 600MPa, 800MPa or 1000MPa, etc.

[0128] Furthermore, the ratio of the thickness of the buffer layer 4 to the thickness of the composite coating can range from 16% to 56%. For example, the ratio of the thickness of the buffer layer 4 to the thickness of the composite coating can be 16%, 20%, 26%, 36%, 46%, or 56%. The buffer layer is soft and has a relatively low elastic modulus, providing good energy absorption. Therefore, setting the buffer layer relatively thick can ensure the overall conformability of the composite coating.

[0129] On the basis of the above, the thermoplastic polyurethane elastomer needs to be coated with a bearing layer to achieve a composite coating 02 with better protection function. Therefore, the embodiment of the present application further provides a bearing layer 5 on the side of the buffer layer 4 away from the cover plate.

[0130] However, if the elastic modulus and thickness of the bearing layer 5 are both too high, the composite coating 02 may be harder as a whole, affecting the adhesion. If the elastic modulus and thickness of the bearing layer 5 are both too low, its performance as the bearing layer 5 may be reduced. Therefore, in the embodiment of the present application, the elastic modulus of the bearing layer 5 is set in the range of 3GPa to 5GPa. In this way, the bearing layer 5 has a higher elastic modulus, that is, it has higher rigidity. Then, when subjected to a large impact or pressure, the deformation degree of the bearing layer 5 is small. For example, the elastic modulus of the bearing layer 5 can be 3GPa, 3.5GPa, 4GPa, 4.5GPa, 4.8GPa or 5GPa, etc.

[0131] In addition, the load-bearing layer 5 may also have a high tensile strength, so that when subjected to a large external force such as impact or pressure, the load-bearing layer 5 is less likely to break. Therefore, in the embodiment of the present application, the tensile strength of the load-bearing layer 5 may be greater than or equal to 50 MPa. For example, the tensile strength of the load-bearing layer 5 may be 50 MPa, 60 MPa, 70 MPa, 80 MPa, 90 MPa, or 100 MPa.

[0132] Therefore, the load-bearing layer 5 of the embodiment of the present application has a high elastic modulus and high tensile strength, so that the load-bearing layer 5 can significantly reduce the kinetic energy of the impact object while it itself is not prone to large deformation. Then, when the stress wave reaches the surface of the load-bearing layer 5, the lateral and longitudinal deformations of the load-bearing layer 5 are small, and the load-bearing layer 5 relies on the tiny deformation in the vertical direction to absorb part of the impact energy, and can resist the penetration of sharp objects to a certain extent by destroying the impact object or causing it to deform.

[0133] The material of the load-bearing layer 5 can include any one of polyethylene terephthalate (PET), polycarbonate (PC), polyimide (PI) and polysulfone (PSU), etc. These materials have high elastic modulus and high tensile strength, which can enable the load-bearing layer 5 to achieve high elastic modulus and high tensile strength.

[0134] Furthermore, considering the comprehensive cost and the requirements of the composite coating 02 for the touch screen, the material of the load-bearing layer 5 is preferably polyethylene terephthalate.

[0135] Furthermore, the ratio of the thickness of the load-bearing layer 5 to the thickness of the composite coating can range from 15% to 50%. For example, the ratio of the thickness of the load-bearing layer 5 to the thickness of the composite coating 02 can be 15%, 20%, 25%, 30%, 40%, or 50%. As a result, the load-bearing layer has higher rigidity, is not too hard as a whole, does not affect the lamination, and has better performance as a load-bearing layer.

[0136] It should be noted that when the thickness of the buffer layer 4 and the load-bearing layer 5 in the composite coating 02 are both relatively high, for example, when the thickness of the load-bearing layer 5 reaches more than 50 μm, the overall stiffness of the composite coating 02 is relatively high. At this time, the composite coating 02 is suitable for bonding to straight screens without curvature (for example, 2D, 2.5D display screens); and if the thickness of the load-bearing layer 5 is slightly reduced, the composite coating 02 at this time can be bonded to, for example, a 3D curved screen by hot pressing.

[0137] In application, the material of the hardened coating 3 of the embodiment of the present application may include resin or hard particles, wherein the resin may include acrylic resin, etc., and the hard particles may include any one of silicone, silicon oxide (SiO2), titanium oxide (TiO2), aluminum oxide (Al2O3), etc.

[0138] Specifically, the silicon oxide may be nano silicon oxide, the titanium oxide may be nano titanium oxide, and the aluminum oxide may be nano aluminum oxide.

[0139] The ratio of the thickness of the hardened coating 3 to the thickness of the composite coating 02 can range from 1% to 3%. For example, the ratio of the thickness of the hardened coating 3 to the thickness of the composite coating 02 can be 1%, 1.8%, 2%, 2.2%, 2.5%, or 3%. Thus, the hardened coating 3 can enhance the hardness, wear resistance, and scratch resistance of the composite coating 02, reduce friction damage to the composite coating 02 caused by impacting objects, and ensure a good surface feel.

[0140] Furthermore, when the hardened coating 3 is applied to the surface of the anti-scratch layer 2, the dynamic friction coefficient of the composite coating 02 can be less than or equal to 0.1. For example, the dynamic friction coefficient of the composite coating 02 can be 0.01, 0.02, 0.03, 0.04, 0.05, or 0.1. This improves the friction resistance of the composite coating 02 and slows down the failure rate and duration of the composite coating 02, thereby effectively protecting the cover plate and even the display screen.

[0141] In practice, the material of the adhesive layer of the embodiment of the present application can include any one of silicone, silicone gel, optically clear adhesive (OCA), and polyurethane (PU). Therefore, the adhesive layer 1 mainly serves to bond the impact-resistant layer 2 to the cover plate and also plays a certain role in buffering and absorbing energy.

[0142] Moreover, the ratio of the thickness of the bonding layer 1 to the thickness of the composite coating 02 may range from 10% to 16%. For example, the ratio of the thickness of the bonding layer 1 to the thickness of the composite coating 02 may be 10%, 11%, 12%, 14%, 15% or 16%, etc.

[0143] It should be noted that before the composite coating 02 (also called the use layer) is produced and attached to the cover plate, a first protective film 10 is usually attached to the side of the hardening coating 3 of the composite coating 02 away from the impact-resistant layer 2, and a second protective film 11 is attached to the side of the adhesive layer 1 away from the impact-resistant layer 2 to obtain a composite coating preparation 03, so that the composite coating 02 can be well protected by the first protective film 10 and the second protective film 11. When it needs to be used, the first protective film 10 and the second protective film 11 need to be torn off before it can be used.

[0144] In practice, the first protective film 10 and the second protective film 11 can both be release films composed of polyethylene terephthalate and an adhesive layer. The adhesive layer can be made of any of silicone, silicone gel, optical adhesive, and polyurethane. Of course, the first protective film 10 and the second protective film 11 can also be made of different materials, as long as they can protect the active layer before removal.

[0145] The thickness of the first protective film 10 may range from 30 μm to 75 μm. For example, the thickness of the first protective film 10 may be 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, or 75 μm.

[0146] The thickness of the second protective film 11 may range from 30 μm to 75 μm. For example, the thickness of the second protective film 11 may be 30 μm, 40 μm, 50 μm, 60 μm, 70 μm or 75 μm.

[0147] Figure 7 Shows a Figure 6 Preparation process route of composite coating preparation 03.

[0148] like Figure 7 As shown in Figure (a), take out the polyethylene terephthalate plastic particles; Figure 7 As shown in FIG. 2( b ), polyethylene terephthalate plastic particles are made into a load-bearing layer 5 by extrusion + uniaxial stretching or extrusion + biaxial stretching; Figure 7 As shown in Figure (c), nano-silicon oxide is coated on one side of the bearing layer 5 to form a hardened coating 3; Figure 7 As shown in Figure (d), a thermoplastic polyurethane elastomer is coated on the side of the bearing layer 5 away from the hardening coating 3 and cured to form a buffer layer 4; Figure 7 As shown in Figure (e), silicone is coated on the side of the buffer layer 4 away from the bearing layer 5 to form an adhesive layer 1; Figure 7 As shown in Figure (f), a first protective film 10 is attached to the side of the hardening coating 3 away from the bearing layer 5, and a second protective film 11 is attached to the side of the adhesive layer 1 away from the buffer layer 4 to obtain a composite coating preparation.

[0149] In one or more embodiments, when the display screen is a touch screen, a reasonable thickness range of the composite coating for the touch screen is generally less than or equal to 0.2 mm.

[0150] On this basis, if Figure 5 As shown, along the OY direction, the thickness d4 of the buffer layer may range from 25 μm to 85 μm. For example, d4 may be 25 μm, 35 μm, 45 μm, 55 μm, 65 μm or 85 μm.

[0151] like Figure 5 As shown, along the OY direction, the thickness d5 of the bearing layer may range from 23 μm to 75 μm. For example, d5 may be 23 μm, 35 μm, 45 μm, 55 μm, 65 μm or 75 μm.

[0152] like Figure 5As shown, along the OY direction, the thickness d3 of the hardened coating layer may range from 2 μm to 8 μm. For example, d3 may be 2 μm, 3 μm, 4 μm, 5 μm, 6 μm or 8 μm.

[0153] The adhesive layer 1 is mainly used to enhance the bonding strength between the cover plate and other upper film layers, so it cannot be too thick. Figure 5 As shown, along the OY direction, the thickness d1 of the adhesive layer may range from 15 μm to 25 μm. For example, d1 may be 15 μm, 16 μm, 18 μm, 20 μm, 22 μm or 25 μm.

[0154] It should be noted that after the thickness of each layer is determined, the thickness tolerance of each layer can be controlled within ±5 μm, ensuring that the composite coating 02 as a whole can withstand an impact energy of 0.2J to 1J.

[0155] Within the allowable range of thickness of electronic equipment, taking the thickness range of the composite coating 02 as 100μm to 200μm as an example, it is preferred that the thickness of the buffer layer 4 accounts for a greater proportion of the thickness of the composite coating 02 than the thickness of the load-bearing layer 5 in the thickness of the composite coating 02. For example, d3=3μm, d5=50μm, d4=82μm, and d1=15μm.

[0156] In addition, the thickness of the load-bearing layer 5 may account for a greater proportion of the thickness of the composite coating 02 than the thickness of the buffer layer 4. For example, d3 = 3 μm, d5 = 75 μm, d4 = 57 μm, and d1 = 15 μm.

[0157] In addition, the refractive index of the buffer layer 4 can be set to be in the range of 1 to 2, and the optical transmittance of the buffer layer 4 can be greater than or equal to 85%. For example, the refractive index of the buffer layer 4 can be 1, 1.2, 1.4, 1.6, 1.8, or 2, and the optical transmittance of the buffer layer 4 can be 85%, 87%, 89%, 90%, 91%, or 92%.

[0158] The refractive index of the supporting layer 5 can be set to be in the range of 1 to 2, and the optical transmittance of the supporting layer 5 can be greater than or equal to 85%. For example, the refractive index of the supporting layer 5 can be 1, 1.2, 1.4, 1.6, 1.8, or 2, and the optical transmittance of the supporting layer 5 can be 85%, 87%, 89%, 90%, 91%, or 92%.

[0159] The refractive index of the hardened coating layer 3 may be set to be in the range of 1 to 2. For example, the refractive index of the hardened coating layer 3 may be 1, 1.2, 1.4, 1.6, 1.8 or 2.

[0160] Therefore, the refractive index of the buffer layer 4, the bearing layer 5 and the hardened coating 3 can make the transmittance of the composite coating 02 higher, so that when the composite coating 02 is applied on the transparent glass cover, it can adapt to the transparent glass cover to present a better transparent effect without affecting the normal display of the display screen.

[0161] It should be noted that the transparent glass cover is set on the display screen, and the light emitted from the display screen enters the composite coating 02 after passing through the transparent glass cover, and the side of the transparent glass cover away from the display screen is the light-emitting side.

[0162] Figure 8 Shown with Figure 5 The simplified model diagram of the force on the cover 105 when the electronic device with the composite coating 02 falls is shown.

[0163] like Figure 8 As shown, the moment the electronic device falls and touches the ground, it is subjected to a strong initial impact force F from the outside world. 总 The impact force generates a shock wave, which carries the impact energy and propagates through the medium. The bearing layer 5 in the composite coating 02, leveraging its high rigidity, can largely reflect and refract the shock wave, significantly reducing the kinetic energy of the impacting object without significantly deforming itself, thus providing resistance to external penetration. Furthermore, the buffer layer 4, through its own significant deformation, absorbs the impact energy that causes the composite coating 02 to deform laterally and longitudinally. The impact energy absorbed in these two processes ultimately manifests as deformation or damage to the composite coating 02. At the same time, at the interface between the composite coating 02 and the glass cover plate 1051, the shock wave not only advances along the direction of the composite coating 02 toward the glass cover plate 1051, but also forms a reflected wave that is reflected from the glass cover plate 1051 back to the composite coating 02. Part of the reflected wave returns along the original direction, while another part of the propagation direction is changed, thereby traveling at the interface between the composite coating 02 and the glass cover plate 1051. This part of the shock wave may cause delamination at the interface between the composite coating 02 and the glass cover plate 1051. That is, the impact energy absorbed in this process manifests as interface delamination, which is also a way to reduce the force transmitted to the glass cover plate 1051. Through the above process, the shock wave is gradually attenuated, and the corresponding impact force is dispersed, so that the force F finally transmitted to the surface of the glass cover plate 1051 can be reduced compared to the initial impact force F. 总 Therefore, the glass cover 1051 is not easily broken.

[0164] Among them, F 总 Determined by the actual application scenario, and because F 总 It is random, so the range of F cannot be defined, but the buffer energy absorption rate of composite coating 02 can be used to estimate F compared to F 总 The percentage range of reduction.

[0165] Thus, the composite coating 02 can provide excellent impact protection for the display screen. The composite coating 02 has a buffering energy absorption rate greater than 25% and can withstand impact energies of 0.2J to 1J. The overall light transmittance of the composite coating 02 is greater than 85%, and the haze of the composite coating 02 is less than or equal to 2%, so that the composite coating 02 does not affect the display effect of the display screen. For example, the buffering energy absorption rate of the composite coating 02 can be 25%, 30%, 33%, 35%, 40%, or 45%, etc. The impact energy that the composite coating 02 can withstand can be 0.2J, 0.4J, 0.6J, 0.8J, 0.9J, or 1J, etc. The overall light transmittance of the composite coating 02 can be 90%, 91%, 92%, 93%, 94%, or 95%, etc. The haze of the composite coating 02 can be 0.5%, 0.8%, 1%, 1.4%, 1.7%, or 2%, etc.

[0166] The composite coating provided in the embodiment of the present application is bonded to the cover plate through an adhesive layer, and a buffer layer, a load-bearing layer and a hardened coating are sequentially stacked on the adhesive layer. In this way, when the composite coating is subjected to a large external impact force due to collision, falling, etc., the hardened coating reduces the friction damage of the impact force to the composite coating. Then the load-bearing layer relies on its slight deformation in the vertical direction to absorb part of the impact energy, and by destroying the impact object or causing it to deform, it resists the penetration of sharp objects to a certain extent. Then the buffer layer can absorb more energy during the deformation process by producing a larger deformation, absorb and disperse most of the impact energy, and significantly improve the impact resistance of the composite coating.

[0167] Therefore, when an electronic device using the composite coating of the embodiment of the present application is accidentally colliding or falling, the composite coating can effectively absorb the impact force generated by the collision or falling, greatly improving the ability of the display screen to resist external impact, protecting the display screen from damage, and effectively extending the service life of the electronic device, greatly improving reliability, reducing maintenance costs, and ensuring user safety and a good user experience.

[0168] As Figure 5 The deformation, Figure 9 Composite coating 02 with Figure 5 The difference of composite coating 02 is:

[0169] like Figure 9 As shown, the buffer layer 4 is arranged between the bearing layer 5 and the hardening coating 3 , and the bearing layer 5 is arranged between the adhesive layer 1 and the buffer layer 4 .

[0170] Figure 10 Shows a Figure 9 Preparation process route of composite coating preparation of composite coating 02.

[0171] like Figure 10As shown in Figure (a), take out the polyethylene terephthalate plastic particles; Figure 10 As shown in FIG. 2( b ), polyethylene terephthalate plastic particles are made into a load-bearing layer 5 by extrusion + uniaxial stretching or extrusion + biaxial stretching; Figure 10 As shown in Figure (c), a thermoplastic polyurethane elastomer is coated on one side of the bearing layer 5 and cured to form a buffer layer 4; Figure 10 As shown in Figure (d), nano-silicon oxide is coated on the side of the buffer layer 4 away from the bearing layer 5 to form a hardened coating 3; Figure 10 As shown in Figure (e), silicone is coated on the side of the buffer layer 4 away from the bearing layer 5 to form an adhesive layer 1; Figure 10 As shown in Figure (f), a first protective film 10 is attached to the side of the hardening coating 3 away from the bearing layer 5, and a second protective film 11 is attached to the side of the adhesive layer 1 away from the buffer layer 4 to obtain a composite coating preparation.

[0172] The composite coating provided in the embodiment of the present application is bonded to the cover plate through an adhesive layer, and a load-bearing layer, a buffer layer and a hardened coating are sequentially stacked on the adhesive layer. In this way, when the composite coating is subjected to a large external impact force, the hardened coating reduces the friction damage of the impact force on the composite coating. Then the buffer layer absorbs more energy during the deformation process by producing a large deformation, and absorbs and disperses most of the impact energy. Then the load-bearing layer relies on its slight deformation in the vertical direction to absorb part of the impact energy, and by destroying the impact object or causing it to deform, it resists the penetration of sharp objects to a certain extent, thereby improving the impact resistance of the composite coating, and further improving the ability of the display screen in the electronic device using the composite coating to resist external impact, protecting the display screen from damage, extending the service life of the electronic device, improving reliability, reducing maintenance costs, ensuring user safety, and providing a good user experience.

[0173] 2. The second situation

[0174] Example 2 (reference Figures 11 to 14 ):

[0175] As an example, Figure 11 The composite coating 02 shown with Figure 5 The differences of the composite coating 02 shown are:

[0176] like Figure 11 As shown, the load-bearing layer 5 in the impact-resistant layer 2 includes a first sub-load-bearing layer 51 and a second sub-load-bearing layer 52. The first sub-load-bearing layer 51 is arranged between the buffer layer 4 and the second sub-load-bearing layer 52, and the second sub-load-bearing layer 52 is arranged between the first sub-load-bearing layer 51 and the hardening coating 3.

[0177] The more layers there are in a composite coating, the more interfaces there are in the composite coating. As the shock wave passes through each interface, the propagation direction of part of the shock wave is changed, thereby dispersing the stress. The greater the difference between the upper and lower layers, the greater the change in the direction of the shock wave, and the smaller the energy transmitted along the original direction, thereby achieving the purpose of gradually consuming energy.

[0178] In practice, the materials of the first sub-supporting layer 51 and the second sub-supporting layer 52 can be the same or different, as long as the overall elastic modulus of the support layer 5 is between 3GPa and 5GPa, thereby balancing impact resistance and conformability. For example, the material of the first sub-supporting layer 51 can be polycarbonate, and the material of the second sub-supporting layer 52 can be polyethylene terephthalate; alternatively, the material of the first sub-supporting layer 51 can be polyethylene terephthalate, and the material of the second sub-supporting layer 52 can be polycarbonate. Of course, other materials are also possible, depending on the actual application.

[0179] It should be noted that when the materials of the first sub-bearing layer 51 and the second sub-bearing layer 52 are the same, the number of interfaces of the composite coating 02 is increased, but the difference between the two is not large. However, the propagation direction of the shock wave can be changed after passing through different interfaces, thereby dispersing the stress well.

[0180] When the materials of the first sub-supporting layer 51 and the second sub-supporting layer 52 are different, not only does the number of interfaces of the composite coating 02 increase, but also because the difference between the first sub-supporting layer 51 and the second sub-supporting layer 52 is large, the elastic modulus of the first sub-supporting layer 51 and the second sub-supporting layer 52 is different, which makes the direction of the shock wave change more greatly and the energy transmitted along the original direction is smaller.

[0181] The following description uses the example of a first sub-supporting layer 51 made of polycarbonate and a second sub-supporting layer 52 made of polyethylene terephthalate. Specifically, the first sub-supporting layer 51 can be made of polycarbonate plastic particles or a prefabricated polycarbonate film, and the second sub-supporting layer 52 can be made of polyethylene terephthalate plastic particles or a prefabricated polyethylene terephthalate film.

[0182] It should be noted that, since polyethylene terephthalate generally provides better transparency and optical properties, the thickness of the second sub-supporting layer 52 composed of polyethylene terephthalate needs to account for a ratio greater than or equal to 50% of the thickness of the supporting layer 5. For example, the thickness of the second sub-supporting layer 52 can account for 50%, 55%, 60%, 65%, 70%, 80%, or 90% of the thickness of the supporting layer 5.

[0183] like Figure 11As shown, along the OY direction, when the thickness d5 of the bearing layer ranges from 23 μm to 75 μm, the thickness d51 of the first sub-bearing layer can be set to 9 μm and the thickness d52 of the second sub-bearing layer can be set to 14 μm, of course, it is not limited thereto.

[0184] In applications, the first sub-load-bearing layer 51 and the second sub-load-bearing layer 52 can be prepared by extrusion lamination, hot pressing lamination, radiation cross-linking, and the like.

[0185] Extrusion compounding refers to using a multi-layer co-extruder to heat and melt two identical material particles or two different material particles through independent extruders, and the molten materials converge in the compounding head to form the desired multi-layer structure.

[0186] Hot-press lamination involves physically bonding two films of the same or different materials in a softened state by applying pressure at high temperature. This process is typically performed under specific temperature and pressure conditions to ensure a distinct interface between the films and bond them together without compromising the fundamental properties of the materials.

[0187] Radiation crosslinking involves using a radiation source, such as an electron beam or ultraviolet light, to induce a crosslinking reaction between two films of the same material or two films of different materials. This process can achieve a tight bond between the films without the use of adhesives, improving the overall performance of the composite material.

[0188] It should be noted that the load-bearing layer 5 may also include three or more sub-load-bearing layers, which is not specifically limited here. As long as the overall elastic modulus of the load-bearing layer 5 meets 3GPa~5GPa, it can balance the impact resistance and conformability.

[0189] Figure 12 Shown with Figure 11 The preparation process route of the composite coating preparation of the composite coating 02 is shown.

[0190] like Figure 12 As shown in FIG. 2 (a), polycarbonate plastic particles and polyethylene terephthalate plastic particles, or prefabricated polycarbonate film and prefabricated polyethylene terephthalate film are taken out; Figure 12 As shown in FIG. 2( b ), polycarbonate plastic particles and polyethylene terephthalate plastic particles are extruded and compounded, or a prefabricated polycarbonate film and a prefabricated polyethylene terephthalate film are hot-pressed and compounded or radiation-crosslinked to form a first sub-supporting layer 51 and a second sub-supporting layer 52 on one side of the first sub-supporting layer 51, respectively; Figure 12 As shown in FIG. 5( c ), nano-silicon oxide is coated on the side of the second sub-supporting layer 52 away from the first sub-supporting layer 51 to form a hardened coating 3; Figure 12As shown in FIG. 5(d), a thermoplastic polyurethane elastomer is coated on the side of the first sub-supporting layer 51 away from the second sub-supporting layer 52 and cured to form a buffer layer 4; Figure 12 As shown in FIG. 5 (e), silicone is coated on the side of the buffer layer 4 away from the first sub-load-bearing layer 51 to form an adhesive layer 1; Figure 12 As shown in Figure (f), a first protective film 10 is attached to the side of the hardening coating 3 away from the second sub-bearing layer 52, and a second protective film 11 is attached to the side of the adhesive layer 1 away from the buffer layer 4 to obtain a composite coating preparation.

[0191] The composite coating provided in the embodiment of the present application has a load-bearing layer consisting of two sub-load-bearing layers, so that there are more interfaces in the composite coating. In this way, each time the shock wave passes through an interface, a part of the shock wave propagation direction is changed, thereby dispersing the stress. The more interfaces the shock wave passes through, the more the shock wave is dispersed. At the same time, the greater the change in the direction of the shock wave, the smaller the energy transmitted along the original direction, and the energy is consumed step by step by more layers. In this way, when the composite coating is subjected to a large external impact force, the impact resistance of the composite coating can be further improved, thereby improving the ability of the display screen in the electronic device using the composite coating to resist external impact, protecting the display screen from damage, extending the service life of the electronic device, improving reliability, reducing maintenance costs, ensuring user safety, and providing a good user experience.

[0192] As another example, Figure 13 The composite coating 02 shown with Figure 9 The differences of the composite coating 02 shown are:

[0193] like Figure 13 As shown, the buffer layer 4 in the impact-resistant layer 2 includes a first sub-buffer layer 41 and a second sub-buffer layer 42. The first sub-buffer layer 41 is arranged between the bearing layer 5 and the second sub-buffer layer 42, and the second sub-buffer layer 42 is arranged between the first sub-buffer layer 41 and the hardening coating 3.

[0194] In application, since thermoplastic polyurethane elastomers, silicone and silicone gel are homogeneous and soft, with low elastic modulus and buffering energy absorption effect, the sub-buffer layer can have good buffering properties. Then, when the display screen is subjected to a large impact or pressure due to collision, falling, etc., since the composite coating 02 has a buffer layer 4 made of a material with buffering energy absorption effect, the buffer layer 4 can produce a large deformation when subjected to impact or pressure, and can absorb a lot of energy during the deformation process, thereby absorbing and dispersing most of the impact energy, greatly reducing the impact of external impact force on the display screen.

[0195] However, since the elastic modulus of silicone and silicone gel is much lower than that of thermoplastic polyurethane elastomer, it is necessary to set the material of at least one sub-buffer layer to be thermoplastic polyurethane elastomer to ensure the overall performance of the buffer layer 4.

[0196] Therefore, the materials of the first sub-buffer layer 41 and the second sub-buffer layer 42 can both be thermoplastic polyurethane elastomers; or, the material of one of the first sub-buffer layer 41 and the second sub-buffer layer 42 can be thermoplastic polyurethane elastomer, and the material of the other sub-buffer layer can be other substances, such as silicone or silicone gel, as long as the overall elastic modulus of the buffer layer 4 is between 100 MPa and 1000 MPa, and the impact resistance and conformability can be balanced.

[0197] It should be noted that when the materials of the first sub-buffer layer 41 and the second sub-buffer layer 42 are the same, the number of interfaces of the composite coating 02 is increased, but the difference between the two is not large. However, the propagation direction of the shock wave can be changed after passing through different interfaces, thereby dispersing the stress well.

[0198] When the materials of the first sub-buffer layer 41 and the second sub-buffer layer 42 are different, not only does the number of interfaces of the composite coating 02 increase, but also because the difference between the first sub-buffer layer 41 and the second sub-buffer layer 42 is large and the elastic modulus of the first sub-buffer layer 41 and the second sub-buffer layer 42 is different, the direction of the shock wave changes more greatly and the energy transmitted along the original direction is smaller.

[0199] On this basis, since the elastic modulus of silicone and silicone gel is lower than that of thermoplastic polyurethane elastomer, the proportion of silicone and silicone gel in the buffer layer 4 cannot be too large. Otherwise, the elastic modulus of the buffer layer 4 will be too low, and the corresponding elastic modulus and hardness (e.g., Mohs hardness and Vickers hardness) of the composite coating 02 as a whole will be low, resulting in poor offset and hand feel. Therefore, when the thickness of the sub-buffer layer composed of thermoplastic polyurethane elastomer accounts for a high proportion of the thickness of the entire buffer layer, the overall elastic modulus and hardness of the buffer layer can be appropriate, and the offset and hand feel can be relatively good. Therefore, the ratio of the thickness of the sub-buffer layer composed of thermoplastic polyurethane elastomer to the thickness of the buffer layer can be set to be greater than or equal to 50%. For example, the ratio of the thickness of the sub-buffer layer composed of thermoplastic polyurethane elastomer to the thickness of the buffer layer can be 50%, 60%, 65%, 70%, 80%, or 90%, etc.

[0200] In addition, to ensure good adhesion between the sub-buffer layer and the hardening coating 3 and to ensure good overall performance of the buffer layer 4, it is necessary to set a sub-buffer layer composed of thermoplastic polyurethane elastomer to adhere to the hardening coating. Figure 13 As shown, since the second sub-buffer layer 42 is in contact with the hardening coating 3 , the material of the second sub-buffer layer 42 is thermoplastic polyurethane elastomer, and the material of the first sub-buffer layer 41 is silicone or silicone gel.

[0201] The following description will be made by taking as an example the case where the material of the first sub-buffer layer 41 is silicone and the material of the second sub-buffer layer 42 is thermoplastic polyurethane elastomer.

[0202] like Figure 13 As shown, along the OY direction, when the thickness of the buffer layer 4 ranges from 25 μm to 85 μm, the thickness d41 of the first sub-buffer layer 41 can be set to 11 μm, and the thickness d42 of the second sub-buffer layer 42 can be set to 14 μm.

[0203] In applications, the first sub-buffer layer 41 and the second sub-buffer layer 42 can be prepared by coating or other methods.

[0204] It should be noted that the buffer layer 4 may also include three or more sub-buffer layers, which is not specifically limited here, as long as the overall elastic modulus of the buffer layer 4 is between 100 MPa and 1000 MPa, the buffering performance and offset printing issues can be balanced.

[0205] Based on this, the material design of the sub-buffer layer is explained by taking an example in which the buffer layer 4 includes three sub-buffer layers, namely a first sub-buffer layer, a second sub-buffer layer and a third sub-buffer layer stacked in sequence on the bearing layer. Exemplarily, the material of the first sub-buffer layer may be silicone, the material of the second sub-buffer layer may be silicone gel, and the material of the third sub-buffer layer may be thermoplastic polyurethane elastomer; or, the material of the first sub-buffer layer may be thermoplastic polyurethane elastomer, the material of the second sub-buffer layer may be silicone gel, and the material of the third sub-buffer layer may be thermoplastic polyurethane elastomer; or, the material of the first sub-buffer layer may be thermoplastic polyurethane elastomer, the material of the second sub-buffer layer may be thermoplastic polyurethane elastomer, and the material of the third sub-buffer layer may be thermoplastic polyurethane elastomer; or, the material of the first sub-buffer layer may be silicone, the material of the second sub-buffer layer may be thermoplastic polyurethane elastomer, and the material of the third sub-buffer layer may be thermoplastic polyurethane elastomer; or, the material of the first sub-buffer layer may be silicone gel, the material of the second sub-buffer layer may be thermoplastic polyurethane elastomer, and the material of the third sub-buffer layer may be thermoplastic polyurethane elastomer, etc. The specific material shall be subject to actual application, as long as the material of the sub-buffer layer bonded to the hardening coating 3 is thermoplastic polyurethane elastomer.

[0206] Figure 14 Shown with Figure 13 The preparation process route of the composite coating preparation of the composite coating 02 is shown.

[0207] like Figure 14 As shown in Figure (a), take out the polyethylene terephthalate plastic particles; Figure 14 As shown in FIG. 2( b ), polyethylene terephthalate plastic particles are made into a load-bearing layer 5 by extrusion + uniaxial stretching or extrusion + biaxial stretching. Figure 14As shown in FIG. 5( c ), silica gel is coated on one side of the bearing layer 5 to form a first sub-buffer layer 41; Figure 14 As shown in FIG. 5 (d), a thermoplastic polyurethane elastomer is coated on the side of the first sub-buffer layer 41 away from the bearing layer 5 and cured to form a second sub-buffer layer 42; Figure 14 As shown in FIG. 5 (e), nano-silicon oxide is coated on the side of the second sub-buffer layer 42 away from the first sub-buffer layer 41 to form a hardened coating 3; Figure 14 As shown in FIG. 5 (f), silicone is coated on the side of the bearing layer 5 away from the first sub-buffer layer 41 to form an adhesive layer 1; Figure 14 As shown in Figure (g), a first protective film 10 is attached to the side of the hardening coating 3 away from the second sub-buffer layer 42, and a second protective film 11 is attached to the side of the adhesive layer 1 away from the bearing layer 5 to obtain a composite coating preparation.

[0208] The composite coating provided in the embodiment of the present application has a buffer layer consisting of two sub-buffer layers, which increases the overall stacking interface of the composite coating. In this way, each time the shock wave passes through an interface, a portion of the shock wave propagation direction is changed, thereby dispersing the stress. The more interfaces the shock wave passes through, the more the shock wave is dispersed. At the same time, the greater the change in the direction of the shock wave, the smaller the energy transmitted along the original direction, and the energy is consumed step by step by more layers. In this way, when the composite coating is subjected to a large external impact force, the impact resistance of the composite coating can be further improved, thereby improving the ability of the display screen in the electronic device using the composite coating to resist external impact, protecting the display screen from damage, extending the service life of the electronic device, improving reliability, reducing maintenance costs, ensuring user safety, and providing a good user experience.

[0209] As another example, Figure 15 The composite coating 02 shown with Figure 5 The differences of the composite coating 02 shown are:

[0210] like Figure 15 As shown, the buffer layer 4 in the impact-resistant layer 2 includes a first sub-buffer layer 41 and a second sub-buffer layer 42. The first sub-buffer layer 41 is arranged between the adhesive layer 1 and the second sub-buffer layer 42, and the second sub-buffer layer 42 is arranged between the first sub-buffer layer 41 and the bearing layer 5.

[0211] It should be noted that in Figure 15 In the embodiment, the material of the first sub-buffer layer 41 and the material of the second sub-buffer layer 42 are both thermoplastic polyurethane elastomers; alternatively, the material of the first sub-buffer layer 41 is thermoplastic polyurethane elastomer, and the material of the second sub-buffer layer 42 is silicone or silicone gel; alternatively, the material of the first sub-buffer layer 41 is silicone or silicone gel, and the material of the second sub-buffer layer 42 is thermoplastic polyurethane elastomer. In addition, the thickness of the sub-buffer layer composed of thermoplastic polyurethane elastomer accounts for greater than or equal to 50% of the thickness of the buffer layer 4.

[0212] The composite coating provided in the embodiment of the present application has a buffer layer consisting of two sub-buffer layers. In this way, each time the shock wave passes through an interface, a portion of the shock wave propagation direction is changed, thereby dispersing the stress. The more interfaces the shock wave passes through, the more the shock wave is dispersed. At the same time, the greater the change in the direction of the shock wave, the smaller the energy transmitted along the original direction, and the energy is consumed step by step by more layers. In this way, when the composite coating is subjected to a large external impact force, the impact resistance of the composite coating can be further improved, thereby improving the ability of the display screen in the electronic device using the composite coating to resist external impact, protecting the display screen from damage, extending the service life of the electronic device, improving reliability, reducing maintenance costs, ensuring user safety, and providing a good user experience.

[0213] As another example, Figure 16 The composite coating 02 shown with Figure 9 The differences of the composite coating 02 shown are:

[0214] like Figure 16 As shown, the load-bearing layer 5 in the impact-resistant layer 2 includes a first sub-load-bearing layer 51 and a second sub-load-bearing layer 52. The first sub-load-bearing layer 51 is arranged between the adhesive layer 1 and the second sub-load-bearing layer 52, and the second sub-load-bearing layer 52 is arranged between the first sub-load-bearing layer 51 and the buffer layer 4.

[0215] The composite coating provided in the embodiment of the present application has a load-bearing layer consisting of two sub-load-bearing layers. In this way, each time the shock wave passes through an interface, a portion of the shock wave propagation direction is changed, thereby dispersing the stress. The more interfaces the shock wave passes through, the more the shock wave is dispersed. At the same time, the greater the change in the direction of the shock wave, the smaller the energy transmitted along the original direction, and the energy is consumed step by step by more layers. In this way, when the composite coating is subjected to a large external impact force, the impact resistance of the composite coating can be further improved, thereby improving the ability of the display screen in the electronic device using the composite coating to resist external impact, protecting the display screen from damage, extending the service life of the electronic device, improving reliability, reducing maintenance costs, ensuring user safety, and providing a good user experience.

[0216] 3. The third situation

[0217] Example 3 (reference Figures 17 to 19 ):

[0218] As an example, Figure 17 The composite coating 02 shown with Figure 5 The differences of the composite coating 02 shown are:

[0219] like Figure 17As shown, the load-bearing layer 5 in the impact-resistant layer 2 includes a first sub-load-bearing layer 51 and a second sub-load-bearing layer 52 . The first sub-load-bearing layer 51 is arranged between the adhesive layer 1 and the buffer layer 4 , and the second sub-load-bearing layer 52 is arranged between the buffer layer 4 and the hardening coating 3 .

[0220] Figure 18 Shown with Figure 17 The preparation process route of the composite coating preparation of the composite coating 02 is shown.

[0221] like Figure 18 As shown in FIG. 2( a ), polycarbonate plastic particles, thermoplastic polyurethane elastomer plastic particles, and polyethylene terephthalate plastic particles, or prefabricated polycarbonate films, prefabricated thermoplastic polyurethane elastomer films, and prefabricated polyethylene terephthalate films are taken out; Figure 18 As shown in FIG. 2( b ), polycarbonate plastic particles, thermoplastic polyurethane elastomer plastic particles, and polyethylene terephthalate plastic particles are extruded and compounded, or a prefabricated polycarbonate film, a prefabricated thermoplastic polyurethane elastomer film, and a prefabricated polyethylene terephthalate film are heat-pressed and compounded or radiation-crosslinked to form a first sub-supporting layer 51, and a buffer layer 4 and a second sub-supporting layer 52 sequentially stacked on one side of the first sub-supporting layer 51; Figure 18 As shown in FIG. 5( c ), nano-silicon oxide is coated on the side of the second sub-supporting layer 52 away from the buffer layer 4 to form a hardened coating 3; Figure 18 As shown in FIG. 5(d), silicone is coated on the side of the first sub-supporting layer 51 away from the buffer layer 4 to form an adhesive layer 1; Figure 18 As shown in Figure (e), a first protective film 10 is attached to the side of the hardened coating 3 away from the second sub-bearing layer 52, and a second protective film 11 is attached to the side of the adhesive layer 1 away from the first sub-bearing layer 51 to obtain a composite coating preparation.

[0222] The composite coating provided in the embodiment of the present application has a load-bearing layer consisting of two sub-load-bearing layers, and the two sub-load-bearing layers are respectively arranged on both sides of the buffer layer. In this way, each time the shock wave passes through an interface, a part of the shock wave propagation direction is changed, thereby dispersing the stress. The more interfaces the shock wave passes through, the more the shock wave is dispersed. At the same time, the greater the change in the direction of the shock wave, the smaller the energy transmitted along the original direction, and the energy is consumed step by step by more layers. In this way, when the composite coating is subjected to a large external impact force, the impact resistance of the composite coating can be further improved, thereby improving the ability of the display screen in the electronic device using the composite coating to resist external impact, protecting the display screen from damage, extending the service life of the electronic device, improving reliability, reducing maintenance costs, ensuring user safety, and providing a good user experience.

[0223] As another example, Figure 19 The composite coating 02 shown with Figure 9The differences of the composite coating 02 shown are:

[0224] like Figure 19 As shown, the buffer layer 4 in the impact-resistant layer 2 includes a first sub-buffer layer 41 and a second sub-buffer layer 42 . The first sub-buffer layer 41 is arranged between the adhesive layer 1 and the load-bearing layer 5 , and the second sub-buffer layer 42 is arranged between the load-bearing layer 5 and the hardening coating 3 .

[0225] It should be noted that in Figure 19 In the embodiment, the material of the second sub-buffer layer 42 is thermoplastic polyurethane elastomer, the material of the first sub-buffer layer 41 can be any one of thermoplastic polyurethane elastomer, silicone, and silicone gel, and the ratio of the thickness of the second sub-buffer layer 42 to the thickness of the buffer layer 4 is greater than or equal to 50%.

[0226] The composite coating provided in the embodiment of the present application has a buffer layer consisting of two sub-buffer layers, and the two sub-buffer layers are respectively arranged on both sides of the bearing layer. In this way, each time the shock wave passes through an interface, a part of the shock wave propagation direction is changed, thereby dispersing the stress. The more interfaces the shock wave passes through, the more the shock wave is dispersed. At the same time, the greater the change in the direction of the shock wave, the smaller the energy transmitted along the original direction, and the energy is consumed step by step by more layers. In this way, when the composite coating is subjected to a large external impact force, the impact resistance of the composite coating can be further improved, thereby improving the ability of the display screen in the electronic device using the composite coating to resist external impact, protecting the display screen from damage, extending the service life of the electronic device, improving reliability, reducing maintenance costs, ensuring user safety, and providing a good user experience.

[0227] 3. The fourth situation

[0228] Example 4 (reference Figures 20 to 23 ):

[0229] As an example, Figure 20 The composite coating 02 shown with Figure 5 The differences of the composite coating 02 shown are:

[0230] like Figure 20 As shown, the bearing layer 5 in the impact-resistant layer 2 includes a first sub-bearing layer 51 and a second sub-bearing layer 52, and the buffer layer 4 includes a first sub-buffer layer 41 and a second sub-buffer layer 42, the first sub-buffer layer 41 is arranged between the adhesive layer 1 and the first sub-bearing layer 51, the first sub-bearing layer 51 is arranged between the first sub-buffer layer 41 and the second sub-buffer layer 42, the second sub-buffer layer 42 is arranged between the first sub-bearing layer 51 and the second sub-bearing layer 52, and the second sub-bearing layer 52 is arranged between the second sub-buffer layer 42 and the hardening coating 3.

[0231] It should be noted that in Figure 20In the embodiment, the material of the first sub-buffer layer 41 and the material of the second sub-buffer layer 42 are both thermoplastic polyurethane elastomers; alternatively, the material of the first sub-buffer layer 41 is thermoplastic polyurethane elastomer, and the material of the second sub-buffer layer 42 is silicone or silicone gel; alternatively, the material of the first sub-buffer layer 41 is silicone or silicone gel, and the material of the second sub-buffer layer 42 is thermoplastic polyurethane elastomer. In addition, the thickness of the sub-buffer layer composed of thermoplastic polyurethane elastomer accounts for greater than or equal to 50% of the thickness of the buffer layer 4.

[0232] As Figure 20 The deformation, Figure 21 The composite coating 02 shown with Figure 20 The differences of the composite coating 02 shown are:

[0233] like Figure 21 As shown, the first sub-load-bearing layer 51 is arranged between the adhesive layer 1 and the first sub-buffer layer 41, the first sub-buffer layer 41 is arranged between the first sub-load-bearing layer 51 and the second sub-load-bearing layer 52, the second sub-load-bearing layer 52 is arranged between the first sub-buffer layer 41 and the second sub-buffer layer 42, and the second sub-buffer layer 42 is arranged between the second sub-load-bearing layer 52 and the hardening coating 3.

[0234] It should be noted that in Figure 21 In the embodiment, the material of the second sub-buffer layer 42 is thermoplastic polyurethane elastomer, the material of the first sub-buffer layer 41 can be any one of thermoplastic polyurethane elastomer, silicone, and silicone gel, and the ratio of the thickness of the second sub-buffer layer 42 to the thickness of the buffer layer 4 is greater than or equal to 50%.

[0235] As Figure 20 The deformation, Figure 22 The composite coating 02 shown with Figure 20 The differences of the composite coating 02 shown are:

[0236] like Figure 22 As shown, the first sub-buffer layer 41 is arranged between the adhesive layer 1 and the second sub-buffer layer 42, the second sub-buffer layer 42 is arranged between the first sub-buffer layer 41 and the first sub-load-bearing layer 51, the first sub-load-bearing layer 51 is arranged between the second sub-buffer layer 42 and the second sub-load-bearing layer 52, and the second sub-load-bearing layer 52 is arranged between the first sub-load-bearing layer 51 and the hardening coating 3.

[0237] It should be noted that in Figure 22In the embodiment, the material of the first sub-buffer layer 41 and the material of the second sub-buffer layer 42 are both thermoplastic polyurethane elastomers; alternatively, the material of the first sub-buffer layer 41 is thermoplastic polyurethane elastomer, and the material of the second sub-buffer layer 42 is silicone or silicone gel; alternatively, the material of the first sub-buffer layer 41 is silicone or silicone gel, and the material of the second sub-buffer layer 42 is thermoplastic polyurethane elastomer. In addition, the thickness of the sub-buffer layer composed of thermoplastic polyurethane elastomer accounts for greater than or equal to 50% of the thickness of the buffer layer 4.

[0238] As Figure 20 The deformation, Figure 23 The composite coating 02 shown with Figure 20 The differences of the composite coating 02 shown are:

[0239] like Figure 23 As shown, the first sub-load-bearing layer 51 is arranged between the adhesive layer 1 and the second sub-load-bearing layer 52, the second sub-load-bearing layer 52 is arranged between the first sub-load-bearing layer 51 and the first sub-buffer layer 41, the first sub-buffer layer 41 is arranged between the second sub-load-bearing layer 52 and the second sub-buffer layer 42, and the second sub-buffer layer 42 is arranged between the first sub-buffer layer 41 and the hardening coating 3.

[0240] It should be noted that in Figure 23 In the embodiment, the material of the second sub-buffer layer 42 is thermoplastic polyurethane elastomer, the material of the first sub-buffer layer 41 can be any one of thermoplastic polyurethane elastomer, silicone, and silicone gel, and the ratio of the thickness of the second sub-buffer layer 42 to the thickness of the buffer layer 4 is greater than or equal to 50%.

[0241] The composite coating provided in the embodiment of the present application has a buffer layer consisting of two sub-buffer layers and a load-bearing layer consisting of two sub-load-bearing layers. Each sub-buffer layer is repeatedly stacked alternately with each sub-load-bearing layer, and the elastic moduli of the two adjacent layers are different. This increases the number of interfaces while also increasing the difference in interfaces between the two adjacent layers, further increasing the dissipation of impact energy. In this way, when the composite coating is subjected to a large external impact force, the impact resistance of the composite coating can be further improved, thereby improving the ability of the display screen in the electronic device using the composite coating to resist external impact, protecting the display screen from damage, extending the service life of the electronic device, improving reliability, reducing maintenance costs, ensuring user safety, and providing a good user experience.

[0242] Optionally, as an implementable approach, Figure 24 The composite coating 02 shown with Figure 20 The differences of the composite coating 02 shown are:

[0243] like Figure 24 As shown, the composite coating 02 further includes an anti-fingerprint layer 13 , which is disposed on a side of the hardened coating 3 away from the bearing layer 5 .

[0244] The composite coating provided in the embodiment of the present application can enhance the wear resistance of the composite coating through the anti-fingerprint layer, especially when the user rubs along the palm direction, the friction resistance is stronger, effectively delaying the failure speed and time of the composite coating without affecting the display, thereby effectively extending the use time of the electronic device and improving performance.

[0245] In order to verify the progressiveness of the embodiments of the present application, the samples prepared from the comparative examples and embodiments 1 to 3 are tested below.

[0246] The test method is as follows:

[0247] 1. Dynamic friction coefficient test:

[0248] Testing instrument: MXD-02 friction coefficient tester or other equipment of the same type and specification.

[0249] Set load: 200±20g.

[0250] Start the test: Fix the test sample and move the load 50 mm at 100 mm / min.

[0251] Each sample was tested 3 times.

[0252] 2. Refractive index test:

[0253] Measurement can be performed using refractometer method, interferometer method, critical angle method, etc.

[0254] 3. Light transmittance test:

[0255] GB 2410-2008 “Test method for light transmittance and haze of transparent plastics”.

[0256] Place the test sample in a transmittance meter or spectrophotometer, use the instrument's light source to illuminate the test sample, and record the light intensity when it passes through the test sample without the test sample (i.e., the light intensity of the blank sample) and the light intensity after it passes through the test sample.

[0257] The formula for calculating the light transmittance is: light transmittance (%) = (light intensity passing through the sample / light intensity of the blank sample) × 100%.

[0258] 4. Buffer energy absorption rate test:

[0259] Place the test sample on a stainless steel plate sensor and drop a 32g steel ball from a height of 600mm onto the surface of the test sample. Calculate the percentage of force reduction received by the sensor after the test sample is attached compared to when the test sample is not attached.

[0260] 5. Tensile strength test:

[0261] ASTM D882 Test Method for Tensile Properties of Thin Plastic Films

[0262] Cut out a test sample of standard size from the composite coating, use a tensile testing machine to stretch the sample at an appropriate rate until the test sample breaks, record the force and displacement data, and the maximum tensile force divided by the original cross-sectional area is the tensile strength of the test sample.

[0263] 6. Impact resistance test:

[0264] The test method is steel ball impact, and the specific test steps are as follows:

[0265] The composite coating is applied to the glass cover of the mobile phone display. The thickness and type of the glass cover are fixed. In this test, a commonly used 0.7mm glass cover is selected. A steel ball weighing 66.8±1g is dropped from a certain height onto different parts of the glass cover surface until the glass cover breaks. Figure 25 , Figure 25 Nine test points are shown, with one impact at each point. The height starts from 31.5 cm and increases in steps of 15.5 cm to 126 cm. The corresponding impact energy starts from 0.2 J and increases in steps of 0.1 J to 0.8 J. The energy corresponding to the shattering of the display is recorded. The test sample size is not less than 6 pieces.

[0266] It should be noted that if Figure 25 As shown, the width of the 9 test points along the OX direction is w, and the length along the OY direction is h, the width of every two adjacent test points along the OX direction is 1 / 3w, and the length of every two adjacent test points along the OY direction is 1 / 3h.

[0267] The performance test results are shown in Table 1 below:

[0268] Table 1

[0269]

[0270] It should be noted that in order to prevent the glass in the glass cover from splashing, the same release film was attached to the lower surface of the glass cover during the test.

[0271] As can be seen from Table 1, compared with the comparative example, Examples 1 to 3 of the present application have a composite coating on the surface of the glass cover plate, and the composite coating has excellent impact resistance. Therefore, the composite coatings of Examples 1 to 3 can withstand an average impact energy that is much greater than the average impact energy that the composite coatings of the comparative example can withstand.

[0272] Compared with Examples 2-3, Example 1 of the present application is that the composite coating in Example 2 and the composite coating in Example 3 have a load-bearing layer arranged on the buffer layer near the load-bearing part, while the composite coating in Example 1 has a buffer layer arranged on the load-bearing layer near the load-bearing part. Therefore, in the composite coating in Example 2 and the composite coating in Example 3, most of the impact energy is first borne by the load-bearing layer, and then some of the impact energy is further absorbed by the buffer layer. Therefore, the average impact energy that the composite coating in Example 2 and the composite coating in Example 3 can withstand is higher than the average impact energy that the composite coating in Example 1 can withstand.

[0273] Compared with Example 3, Example 2 of the present application is slightly smaller in thickness of the load-bearing layer in the composite coating in Example 3 than in thickness of the load-bearing layer in the composite coating in Example 2, but the thickness of the buffer layer in the composite coating in Example 3 is larger than that in thickness of the buffer layer in the composite coating in Example 2, so that the buffer layer can better absorb more buffering energy. Therefore, the average impact energy that the composite coating in Example 3 can withstand is higher than the average impact energy that the composite coating in Example 2 can withstand.

[0274] In addition, the coated glass cover prepared based on the embodiment of the present application has anti-scratch and anti-fingerprint effectiveness.

[0275] It should be understood that the above is only intended to help those skilled in the art better understand the embodiments of the present application, and is not intended to limit the scope of the embodiments of the present application. Based on the above examples, those skilled in the art can obviously make various equivalent modifications or changes. Or a combination of any two or any multiple of the above embodiments. Such modifications, changes, or combinations also fall within the scope of the embodiments of the present application.

[0276] It should also be understood that the above description of the embodiments of the present application focuses on emphasizing the differences between the various embodiments. The same or similar points that are not mentioned can be referenced with each other. For the sake of brevity, they will not be repeated here.

[0277] It should also be understood that the division of the modes, situations, categories and embodiments in the embodiments of the present application is only for the convenience of description and should not constitute a special limitation. The features of various modes, categories, situations and embodiments can be combined without contradiction.

[0278] It should also be understood that in the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form new embodiments according to their internal logical relationships.

[0279] Finally, it should be noted that the above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application shall be covered by the scope of protection of the present application. Therefore, the scope of protection of the present application shall be based on the scope of protection of the claims.

Claims

1. A composite coating, characterized in that: Applied to a display module, the display module further includes a cover plate, and the composite coating is provided on the light-emitting side of the cover plate; The composite coating comprises an adhesive layer, an impact-resistant layer and a hardening coating, wherein the adhesive layer is bonded to the cover plate, and the impact-resistant layer is arranged between the adhesive layer and the hardening coating; The impact-resistant layer includes a buffer layer and a load-bearing layer. The modulus of the buffer layer ranges from 100 MPa to 1000 MPa, and the elastic modulus of the load-bearing layer ranges from 3 GPa to 5 GPa.

2. The composite coating according to claim 1, characterized in that The tensile strength of the bearing layer is greater than or equal to 50 MPa.

3. The composite coating according to claim 1 or 2, characterized in that: The ratio of the thickness of the buffer layer to the thickness of the composite coating ranges from 16% to 56%; The ratio of the thickness of the bearing layer to the thickness of the composite coating ranges from 15% to 50%.

4. The composite coating according to any one of claims 1 to 3, characterized in that The bearing layer is arranged between the buffer layer and the hardening coating; The buffer layer includes at least one sub-buffer layer, and the load-bearing layer includes at least one sub-load-bearing layer.

5. The composite coating according to any one of claims 1 to 3, characterized in that The buffer layer is arranged between the bearing layer and the hardening coating; The buffer layer includes at least one sub-buffer layer, and the load-bearing layer includes at least one sub-load-bearing layer.

6. The composite coating according to claim 4 or 5, characterized in that: The buffer layer includes a sub-buffer layer, and the material of the sub-buffer layer is thermoplastic polyurethane elastomer.

7. The composite coating according to claim 4 or 5, characterized in that: The buffer layer includes multiple sub-buffer layers, at least one of which is made of thermoplastic polyurethane elastomer, and the thickness of the sub-buffer layer made of thermoplastic polyurethane elastomer accounts for more than or equal to 50% of the thickness of the buffer layer.

8. The composite coating according to claim 7, characterized in that In the case where the buffer layer is arranged between the load-bearing layer and the hardening coating layer, at least one sub-buffer layer composed of thermoplastic polyurethane elastomer is adhered to the hardening coating layer.

9. The composite coating according to claim 8, characterized in that The buffer layer includes at least a first sub-buffer layer and a second sub-buffer layer, the first sub-buffer layer is arranged between the bearing layer and the second sub-buffer layer, and the second sub-buffer layer is arranged between the first sub-buffer layer and the hardening coating layer; The material of the first sub-buffer layer includes any one of silicone and silicone gel, and the material of the second sub-buffer layer includes thermoplastic polyurethane elastomer.

10. The composite coating according to any one of claims 1 to 3, characterized in that The buffer layer includes an even number of sub-buffer layers, and the load-bearing layer includes an even number of sub-load-bearing layers. Each sub-buffer layer in the even number of sub-buffer layers is alternately arranged with each sub-load-bearing layer in the even number of sub-load-bearing layers.

11. The composite coating according to any one of claims 1 to 3, characterized in that The buffer layer includes an odd number of sub-buffer layers, and the load-bearing layer includes an even number of sub-load-bearing layers, and one sub-buffer layer is arranged between two adjacent sub-load-bearing layers; or, The buffer layer includes an even number of sub-buffer layers, and the load-bearing layer includes an odd number of sub-load-bearing layers, and one sub-load-bearing layer is arranged between two adjacent sub-buffer layers.

12. The composite coating according to claim 10 or 11, characterized in that: The material of at least one sub-buffer layer includes thermoplastic polyurethane elastomer, and the thickness of the sub-buffer layer composed of thermoplastic polyurethane elastomer accounts for greater than or equal to 50% of the thickness of the buffer layer; At least one sub-buffer layer made of thermoplastic polyurethane elastomer is adhered to the hardened coating.

13. The composite coating according to any one of claims 4 to 12, characterized in that The material of the sub-load-bearing layer includes any one of polyethylene terephthalate, polycarbonate, polyimide and polysulfone.

14. The composite coating according to any one of claims 1 to 13, characterized in that The buffer energy absorption rate of the composite coating is greater than 25%; and / or, The dynamic friction coefficient of the composite coating is less than or equal to 0.1; and / or, The composite coating can withstand an impact energy ranging from 0.2J to 1J; and / or, The haze of the composite coating is less than or equal to 2%; and / or, The light transmittance of the composite coating is greater than 85%.

15. The composite coating according to any one of claims 1 to 14, characterized in that The material of the hardening coating layer includes any one of acrylic resin, siloxane, silicon oxide, titanium oxide and aluminum oxide; The ratio of the thickness of the hardened coating to the thickness of the composite coating ranges from 1% to 3%.

16. The composite coating according to any one of claims 1 to 14, characterized in that The material of the adhesive layer includes any one of silicone, silicone gel, optical glue and polyurethane; The ratio of the thickness of the bonding layer to the thickness of the composite coating ranges from 10% to 16%.

17. A display module, characterized in that: The device comprises a display screen, a cover plate and the composite coating according to any one of claims 1 to 16, wherein the cover plate is arranged on the light-emitting side of the display screen, and the composite coating is arranged on a side of the cover plate away from the display screen.

18. An electronic device, characterized in that: Comprising the display module as claimed in claim 17.

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