Appearance part with skin feeling, manufacturing method thereof and electronic equipment

Abstract

The invention provides an appearance part with a skin feeling, a manufacturing method of the appearance part and electronic equipment, and relates to the technical field of electronic products. According to the appearance piece, the middle paint layer and the skin-touch finish paint layer are sequentially arranged on the base material layer, the middle paint layer has the effects of being combined with the base material layer, developing, achieving the texture effect and the like, and the skin-touch finish paint layer is used for enabling the appearance piece to have the skin-touch effect. Wherein the raw materials of the skin-touch finish paint layer comprise organic silicon modified acrylate with the molecular weight of 8000-20000 and polyurethane acrylic resin with the molecular weight of 6000-20000, and after the organic silicon modified acrylate and the polyurethane acrylic resin are mixed according to the proportion of 3: 7-9: 1, a nanoscale micro-wrinkle structure can be formed in the skin-touch finish paint layer through excimer lamp curing and ultraviolet lamp curing in sequence. Due to the nanoscale micro-wrinkle structure, the skin-touch finish paint layer shows an ultra-matte appearance effect, has a smooth and elastic skin-touch effect, and also has good toughness and anti-pollution performance.

Description

Technical Field

[0001] This application relates to the field of electronic product technology, and in particular to a skin-feeling appearance component, its manufacturing method, and electronic equipment. Background Technology

[0002] When purchasing electronic products such as mobile phones, tablets, and laptops, consumers not only consider the performance and configuration of the products, but also have certain requirements for their appearance and texture.

[0003] Currently, an increasing number of manufacturers are focusing on coating designs for the casings and protective cases of electronic products to give them a silky, elastic, or velvety feel. However, existing electronic products cannot simultaneously achieve both a silky and elastic feel in their casings, failing to achieve a truly skin-like experience, and the stain resistance of these casings needs improvement. Summary of the Invention

[0004] This application provides a skin-feeling exterior component, its manufacturing method, and an electronic device. The exterior component has a nanoscale micro-fold structure, presenting an ultra-matte appearance effect while possessing a silky and elastic skin-feeling effect. Furthermore, the exterior component has good toughness and excellent stain resistance.

[0005] The first aspect of this application provides a skin-feeling appearance part, comprising: a substrate layer; an intermediate paint layer disposed on one side of the substrate layer; and a skin-feeling topcoat layer disposed on the surface of the intermediate paint layer facing away from the substrate layer; wherein the skin-feeling topcoat layer comprises an organosilicon-modified acrylate with a molecular weight of 8000-20000 and a polyurethane acrylic resin with a molecular weight of 6000-20000, the ratio of the organosilicon-modified acrylate to the polyurethane acrylic resin being 3:7-9:1, and the skin-feeling topcoat layer having a nanoscale micro-wrinkled structure.

[0006] The skin-feel finish provided in this application consists of an intermediate paint layer and a skin-feel topcoat layer sequentially applied to a substrate layer. The intermediate paint layer serves to bond with the substrate layer, provide color development, and achieve texture effects. The skin-feel topcoat layer imparts a skin-feel effect to the finish. The raw materials for the skin-feel topcoat layer include silicone-modified acrylate with a molecular weight of 8000-20000 and polyurethane acrylic resin with a molecular weight of 6000-20000. By mixing these two materials in a ratio of 3:7-9:1 and then sequentially curing them under an excimer lamp and a UV lamp, a nanoscale micro-wrinkled structure can be formed in the skin-feel topcoat layer. Because both the silicone-modified acrylate and the polyurethane acrylic resin used in the skin-feel topcoat layer have high molecular weights, the coating of the finish has good toughness. The silicone-modified acrylate provides a silky feel and good stain resistance, while the polyurethane acrylic resin provides good elasticity. Furthermore, the nanoscale micro-wrinkled structure gives the skin-feel topcoat layer an ultra-matte finish. Therefore, while the exterior parts have a silky, elastic feel and an ultra-matte finish, they also have good toughness and stain resistance.

[0007] In one possible implementation, the width of the micro-fold structure is 5nm-50nm.

[0008] By controlling the ratio of high molecular weight silicone-modified acrylate and high molecular weight polyurethane acrylic resin, the width distribution of the micro-wrinkled structure in the skin-feel coating layer is made between 5nm and 50nm, and the size of the micro-wrinkled structure reaches the nanometer scale. The nanometer-scale micro-wrinkled structure enables the skin-feel coating layer to truly achieve a skin-feel effect, giving the appearance parts a baby-like tactile experience.

[0009] In one possible implementation, the width of the micro-fold structure is 5nm-20nm.

[0010] By more precisely controlling the ratio of high molecular weight silicone-modified acrylate and high molecular weight polyurethane acrylic resin, the width distribution of the micro-wrinkled structure in the skin-feel coating layer is made between 5nm and 20nm. This results in a more concentrated, uniform, and refined width of the micro-wrinkled structure, achieving a more refined skin-feel effect.

[0011] In one possible implementation, the cross-sectional thickness of the micro-folded structure is less than or equal to 8 μm.

[0012] By controlling the cross-sectional thickness of the micro-folded structure to within 8μm, the micro-folded structure occupies a small space in the thickness direction of the skin-feel coating layer. While achieving a realistic skin-feel effect, this avoids cracking of the skin-feel coating layer, ensuring its integrity and stability.

[0013] In one possible implementation, the cross-sectional thickness of the micro-folded structure is less than or equal to 6.5 μm.

[0014] By controlling the cross-sectional thickness of the micro-fold structure to within 6.5μm, and ensuring that the space occupied by the micro-fold structure in the thickness direction of the skin-feel coating layer is less than half, the skin-feel coating layer can be effectively prevented from cracking, thus improving the integrity and stability of the skin-feel coating layer and ensuring its reliability.

[0015] In one possible implementation, the coefficient of dynamic friction of the skin-feel coating layer is less than or equal to 0.12.

[0016] The coefficient of dynamic friction of the skin-feel coating layer is below 0.12, proving that the surface roughness of the skin-feel coating layer is very low and the surface is very smooth. The skin-feel coating layer truly achieves a silky smooth feel, achieving a baby-like skin-feel experience.

[0017] In one possible implementation, the silicone-modified acrylate has a molecular weight of 8,000-10,000, and the polyurethane acrylic resin has a molecular weight of 6,000-10,000.

[0018] By setting the molecular weight of the silicone-modified acrylate between 8000-10000 and the polyurethane acrylic resin between 6000-10000, it is possible to ensure that both the silicone-modified acrylate and the polyurethane acrylic resin have sufficiently large molecular weights to form a skin-feel topcoat layer with good toughness, preventing cracking and ensuring the integrity and smoothness of the topcoat layer. At the same time, it avoids excessively large molecular weights of the silicone-modified acrylate and polyurethane acrylic resin, which could prevent them from failing to react effectively and form a stable skin-feel topcoat layer.

[0019] In one possible implementation, the thickness of the skin-feel coating layer is 15μm-40μm.

[0020] In one possible implementation, the intermediate paint layer includes a primer layer.

[0021] A primer layer is applied to a substrate layer, upon which the skin-like topcoat layer is then placed. The primer layer enhances the adhesion between paint layers, improving the fullness and decorative effect of the skin-like topcoat. Furthermore, the primer layer provides corrosion resistance, moisture resistance, and salt and alkali resistance, protecting the overall coating of the exterior component and extending its service life. In addition, the primer layer can compensate for surface defects in the substrate layer, enhance the overall coating's hiding power, and improve the appearance of the exterior component.

[0022] In one possible implementation, the intermediate paint layer further includes: a middle paint layer disposed between the primer layer and the skin-feel topcoat layer; or, the intermediate paint layer further includes a color paint layer disposed between the primer layer and the skin-feel topcoat layer.

[0023] By placing an intermediate coat between the primer layer and the skin-feel topcoat layer, the intermediate coat can effectively bond the primer and topcoat layers. Furthermore, the intermediate coat can increase the overall coating thickness and improve its durability. Additionally, the intermediate coat also has leveling properties, eliminating surface defects in the substrate layer and improving the overall smoothness of the coating.

[0024] By setting a color paint layer between the primer layer and the skin-feel topcoat layer, the color paint layer can impart color to the overall coating, serving to color, cover, and decorate, thereby enhancing the color effect of the appearance component. Furthermore, the color paint layer can enhance the mechanical and chemical properties of the overall coating.

[0025] In one possible implementation, the intermediate paint layer includes a color paint layer.

[0026] A skin-like topcoat layer is applied directly onto the substrate layer. The color paint layer imparts color to the overall coating, serving to color, cover, and decorate, enhancing the overall appearance. Furthermore, the color paint layer strengthens the mechanical and chemical properties of the overall coating. Additionally, the color paint layer improves the adhesion of the overall coating, providing protection against corrosion, moisture, and salt and alkali.

[0027] In one possible implementation, the substrate layer is a metal layer, and a micro-arc oxidation layer is provided between the substrate layer and the intermediate paint layer.

[0028] When the substrate layer is a metal layer, by setting a micro-arc oxidation layer between the substrate layer and the intermediate paint layer, the micro-arc oxidation layer can improve the hardness, wear resistance and corrosion resistance of the substrate layer, enhance the adhesion of the paint layer on the substrate layer, improve the stability and reliability of the appearance parts, and extend the service life of the appearance parts.

[0029] In one possible implementation, the substrate layer is an aramid fiber layer, and a polishing paint layer is provided between the substrate layer and the intermediate paint layer.

[0030] When the substrate layer is an aramid fiber layer, a sanding paint layer is placed between the substrate layer and the intermediate paint layer. This sanding paint layer is then sanded 1-3 times before the intermediate paint layer is applied. The sanding paint layer fills in surface defects in the aramid fiber layer, improving the smoothness and finish of the finished product. Furthermore, sanding the sanding paint layer increases its roughness, enhancing the adhesion of the paint layer to it.

[0031] A second aspect of this application provides a method for manufacturing a skin-feeling appearance part, comprising: providing a substrate layer; forming an intermediate paint layer on the substrate layer; and forming a skin-feeling topcoat layer on the intermediate paint layer.

[0032] The process of forming a skin-feel topcoat layer on the intermediate paint layer includes: mixing silicone-modified acrylate with a molecular weight of 8,000-20,000 and polyurethane acrylic resin with a molecular weight of 6,000-20,000 in a ratio of 3:7-9:1 to form a topcoat coating; applying the topcoat coating to the surface of the intermediate paint layer to form a topcoat coating layer; irradiating the topcoat coating layer with an excimer lamp to partially cure the topcoat coating layer; and irradiating the topcoat coating layer with an ultraviolet lamp to completely cure the topcoat coating layer to form a skin-feel topcoat layer.

[0033] The method for manufacturing the appearance part provided in this application involves sequentially forming an intermediate paint layer and a skin-feel topcoat layer on a substrate layer. The intermediate paint layer serves to bond with the substrate layer, provide color development, and achieve texture effects. The skin-feel topcoat layer is used to give the appearance part a skin-feel effect. Specifically, a topcoat coating is formed by mixing a silicone-modified acrylate with a molecular weight of 8000-20000 and a polyurethane acrylic resin with a molecular weight of 6000-20000 in a ratio of 3:7-9:1. After applying the topcoat coating onto the intermediate paint layer to form a topcoat layer, the topcoat layer is cured by sequentially irradiating it with an excimer lamp and then with an ultraviolet lamp to form the skin-feel topcoat layer. This allows for the formation of nanoscale micro-wrinkles within the skin-feel topcoat layer. Because both the silicone-modified acrylate and the polyurethane acrylic resin used in the skin-feel topcoat layer have high molecular weights, the coating on the appearance part possesses good toughness. The silicone-modified acrylate provides a silky feel and good stain resistance, while the polyurethane acrylic resin provides good elasticity. Furthermore, the nanoscale micro-fold structure gives the skin-feel coating an ultra-matte finish. Therefore, while possessing a silky, elastic feel and an ultra-matte finish, the exterior components also exhibit good toughness and stain resistance.

[0034] In one possible implementation, before irradiating the topcoat coating with an excimer lamp, the method further includes: irradiating the topcoat coating with an LED lamp to pre-cure the topcoat coating.

[0035] The topcoat coating is pre-cured by irradiating it with LED lights to allow it to dry, which facilitates subsequent curing with excimer lamps.

[0036] In one possible implementation, before irradiating the topcoat coating with LED lights, the process further includes baking the topcoat coating at a preset temperature for a predetermined time.

[0037] In one possible implementation, forming an intermediate paint layer on a substrate layer includes: applying a primer layer on the substrate layer.

[0038] When the intermediate paint layer includes a primer layer, the primer layer can be applied first to the substrate layer, followed by the application of other intermediate paint layers or a skin-feel topcoat layer. Alternatively, the substrate layer can be surface-treated, for example, by forming a micro-arc oxidation layer or sanding the primer layer before applying the primer layer.

[0039] In one possible implementation, forming an intermediate paint layer on a substrate layer further includes: applying an intermediate paint layer on a primer layer, or applying a color paint layer on a primer layer.

[0040] When the intermediate paint layer also includes a middle paint layer, a primer layer is applied to the substrate layer to form a primer layer, and then a middle paint layer is applied to the primer layer to form a middle paint layer. When the intermediate paint layer also includes a color paint layer, a primer layer is applied to the substrate layer to form a primer layer, and then a color paint layer is applied to the primer layer to form a color paint layer.

[0041] In one possible implementation, forming an intermediate paint layer on a substrate layer includes: coating a colored paint layer on the substrate layer.

[0042] When the intermediate paint layer does not include the primer layer, the color paint layer can be directly applied to the substrate layer, followed by a skin-feel topcoat layer. This can be achieved by surface treatment of the substrate layer, such as forming a micro-arc oxidation layer or sanding the primer layer before applying the color paint layer.

[0043] A third aspect of this application provides an electronic device including a skin-feeling appearance component as described above.

[0044] The electronic device provided in this application includes a skin-feeling exterior component. The exterior component is constructed by sequentially applying an intermediate paint layer and a skin-feeling topcoat layer to a substrate layer. The intermediate paint layer serves to bond with the substrate layer, provide color development, and achieve texture effects. The skin-feeling topcoat layer imparts a skin-feeling effect to the exterior component. The raw materials for the skin-feeling topcoat layer include silicone-modified acrylate with a molecular weight of 8000-20000 and polyurethane acrylic resin with a molecular weight of 6000-20000. By mixing the two in a ratio of 3:7-9:1 and then sequentially curing them under an excimer lamp and a UV lamp, a nanoscale micro-wrinkled structure can be formed in the skin-feeling topcoat layer. Because both the silicone-modified acrylate and the polyurethane acrylic resin used in the skin-feeling topcoat layer have high molecular weights, the coating of the exterior component possesses good toughness. The silicone-modified acrylate provides a silky feel and good stain resistance, while the polyurethane acrylic resin provides good elasticity. Furthermore, the nanoscale micro-wrinkled structure gives the skin-feeling topcoat layer an ultra-matte finish. Therefore, while the exterior parts have a silky, elastic feel and an ultra-matte finish, they also have good toughness and stain resistance. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application;

[0046] Figure 2 for Figure 1 The exploded structure diagram of the electronic device shown;

[0047] Figure 3 This is a schematic diagram of another electronic device in an open state provided in an embodiment of this application;

[0048] Figure 4 for Figure 3 A schematic diagram of the electronic devices in a locked state;

[0049] Figure 5 This is a schematic diagram of the structure of a third electronic device provided in an embodiment of this application;

[0050] Figure 6 This is a structural schematic diagram of an appearance component in the related technology;

[0051] Figure 7 This is a structural schematic diagram of another appearance component in the related technology;

[0052] Figure 8 This is a structural schematic diagram of the third type of appearance component in the related technology;

[0053] Figure 9 This is a structural schematic diagram of the first type of appearance component provided in the embodiments of this application;

[0054] Figure 10 This is a structural schematic diagram of the second type of appearance component provided in the embodiments of this application;

[0055] Figure 11 This is a structural schematic diagram of the third type of appearance component provided in the embodiments of this application;

[0056] Figure 12 This is a structural schematic diagram of the fourth type of appearance component provided in the embodiments of this application;

[0057] Figure 13 This is a structural schematic diagram of the fifth type of appearance component provided in the embodiments of this application;

[0058] Figure 14 This is a structural schematic diagram of the sixth type of appearance component provided in the embodiments of this application;

[0059] Figure 15 This is a structural schematic diagram of the seventh type of appearance component provided in the embodiments of this application;

[0060] Figure 16 This is a structural schematic diagram of the eighth type of appearance component provided in the embodiments of this application;

[0061] Figure 17 A comparison of SEM results between the skin-feel coating layer and the ordinary skin-feel coating layer provided in the embodiments of this application;

[0062] Figure 18 SEM results of the skin-feel coating layer provided in the embodiments of this application;

[0063] Figure 19 SEM results of the micro-wrinkle structure in the skin-feel coating layer provided in the embodiments of this application;

[0064] Figure 20 The friction coefficient test results of the skin-feel coating layer provided in the embodiments of this application;

[0065] Figure 21 A flowchart illustrating the steps of a method for manufacturing an exterior component according to an embodiment of this application;

[0066] Figure 22 This is a flowchart illustrating the steps of forming a skin-feel topcoat layer on an intermediate paint layer, as provided in an embodiment of this application.

[0067] Explanation of reference numerals in the attached figures:

[0068] 10-Electronic devices;

[0069] 100 - Display screen; 200 - Housing; 300 - Circuit board; 400 - Battery; 500 - Camera; 600 - Monitor; 700 - Main unit; 800 - Keyboard; 900 - Exterior parts;

[0070] 210 - Mid-frame; 220 - Back cover; 230 - Back shell; 610 - Display screen; 620 - Back cover; 710 - Main unit shell; 720 - Keyboard; 730 - Touchpad; 910 - Substrate layer; 920 - Intermediate paint layer; 930 - Skin-feel topcoat layer;

[0071] 711 - Main unit top cover; 712 - Main unit bottom cover; 911 - Magnesium alloy layer; 912 - Polycarbonate layer; 913 - Aramid fiber layer; 914 - Composite material layer; 915 - TPU layer; 921 - Primer layer; 922 - Color paint layer; 923 - Intermediate paint layer;

[0072] 9201 - Micro-arc oxidation layer; 9202 - Polished paint layer; 9203 - Solid color paint layer; 9231 - Transparent intermediate paint layer; 9232 - Colored intermediate paint layer; 9301 - Micro-wrinkled structure;

[0073] 92321 - Light-transmitting hole. Detailed Implementation

[0074] The terminology used in the implementation section of this application is for the purpose of explaining specific embodiments of this application only, and is not intended to limit this application.

[0075] This application provides an electronic device, which can be a consumer electronics product. Exemplary examples include, but are not limited to, mobile phones, portable Android devices (PADs), laptops, laptop computers, netbooks, ultra-mobile personal computers (UMPCs), walkie-talkies, point-of-sale (POS) machines, personal digital assistants (PDAs), multimedia players, e-book readers, in-vehicle devices, wearable devices, virtual reality (VR) devices, and augmented reality (AR) devices. Wearable devices include, but are not limited to, smart bracelets, smartwatches, smart head-mounted displays, and smart glasses.

[0076] Figure 1 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. (Refer to...) Figure 1As shown in the figure, taking a mobile phone as an example, the electronic device 10 may include a display screen 100 and a housing 200. One side surface of the display screen 100 is used to display images, text, and other information; this side surface is typically defined as its front, and the opposite side surface is its back. The housing 200 surrounds the periphery and back of the display screen 100, supporting and securing it, and providing protection. The front of the display screen 100 is exposed outside the housing 200, allowing the user to view the content displayed on the display screen 100 or perform input operations on the electronic device 10.

[0077] Figure 2 for Figure 1 The diagram shows the exploded structure of the electronic device. (Refer to...) Figure 2 As shown, the housing 200 of the electronic device 10 may include a mid-frame 210 and a rear cover 220. The mid-frame 210 is connected between the display screen 100 and the rear cover 220. The display screen 100 is supported on one side surface of the mid-frame 210, and the rear cover 220 is connected to the other side surface of the mid-frame 210.

[0078] The display screen 100 is typically mounted integrally on the mid-frame 210 to ensure its strength and stability, and to meet its usage requirements. The back cover 220 is usually connected to the mid-frame 210 by overlapping. The mid-frame 210 and the back cover 220 together form a receiving cavity, which is used to install components such as the circuit board 300, battery 400, camera 500, and speaker (not shown in the figure).

[0079] Figure 3 This is a schematic diagram of another electronic device in an open state, provided in an embodiment of this application. Figure 4 for Figure 3 A schematic diagram of the electronic devices in a locked state. (Refer to...) Figure 3 and Figure 4 As shown in the figure, taking a laptop computer as an example, electronic device 10 can include a display 600 and a host computer 700, with the display 600 electrically connected to the host computer 700. The display 600 is used to display images, text, and other information. A display 600 equipped with a touchscreen can also provide input functionality. The host computer 700 is used to process information and data. In some cases, such as when the display 600 can be used independently of the host computer 700, the display 600 can also process information and data in addition to displaying and inputting information.

[0080] Taking the rotating connection between the monitor 600 and the host 700 as an example, when the electronic device 10 needs to be used, the monitor 600 can be rotated to a position away from the host 700. There is an angle θ between the monitor 600 and the host 700 (0° < θ < 180°). Usually, this angle θ > 90° (refer to...). Figure 3 (As shown). At this time, the electronic device 10 is in the open state, and the user can perform input operations through the host 700 and view images, text, and other information using the display 600. When the electronic device 10 is not needed, the display 600 can be flipped towards the host, so that the display 600 covers the host 700 (see reference). Figure 4 (As shown). At this time, the electronic device 10 is in a locked state, and the user cannot perform input operations or view images, text, or other information on the display 600.

[0081] Among them, combined Figure 3 and Figure 4 As shown, the display 600 may include a display screen 610 and a back cover 620. The front of the display screen 610 is used to display images, text and other information. The back cover 620 is disposed around the back and sides of the display screen 610 and is used to support the display screen 610 and provide protection for the display screen 610.

[0082] The host 700 may include a host casing 710, a keyboard 720, and a touchpad 730. The host casing 710 includes a top cover 711 and a bottom cover 712. The keyboard 720 and touchpad 730 may be mounted on the top cover 711. The keyboard 720 is used to input commands or data. The touchpad 730 can be used as a mouse. The user's finger touches on the touchpad 730 (including swiping, clicking, etc.) control the cursor movement on the display 600 to perform mouse operations such as "cursor navigation," "selection," and "confirmation." The host casing 710 can house components such as a motherboard, battery, and heat sink.

[0083] Figure 5 This is a schematic diagram of the structure of a third electronic device provided in an embodiment of this application. (Refer to...) Figure 5 As shown in the figure, taking a tablet computer as an example, the electronic device 10 may include a display screen 100 and a housing 200. The front of the display screen 100 is used to display images, text, and other information. The housing 200 surrounds the periphery and back of the display screen 100, and is used to support and fix the display screen 100 and provide protection.

[0084] The housing 200 may include a rear housing 230 and a support plate (not shown in the figure). The support plate is connected to the side of the rear housing 230 facing the display screen 100, and the display screen 100 can be mounted on the support plate. The rear housing 230 and the support plate together form a receiving cavity, which is used to install circuit boards, batteries, cameras, speakers, and other devices.

[0085] like Figure 5As shown, the tablet computer can also be equipped with a keyboard 800, which is independent of the tablet computer. The keyboard 800 and the tablet computer can communicate and connect via wireless transmission methods such as Bluetooth, allowing input operations to be performed through the keyboard 800. Furthermore, in some embodiments, the keyboard 800 can also support the tablet computer, allowing the tablet computer to be placed at a suitable angle on the keyboard 800 for easy user operation.

[0086] As described in the background section, in order to improve the appearance and texture of the electronic device 10, the manufacturer will apply a coating design to the exterior components of the electronic device 10 to give them a silky, elastic, or velvety feel. These exterior components of the electronic device 10 may include the mid-frame 210 and back cover 220 of the aforementioned mobile phone; the back cover 620, top cover 711, bottom cover 712, and keycaps of the keyboard 720 of the aforementioned laptop; the back cover 230 and keycaps of the keyboard 800 of the aforementioned tablet computer; and may also include protective cases for the aforementioned mobile phones, tablet computers, and other electronic devices.

[0087] However, in existing electronic devices, the exterior components typically cannot simultaneously achieve a silky smooth and elastic feel, failing to deliver a truly realistic skin-like experience. Furthermore, in achieving elasticity and a velvety texture, the stain resistance of the exterior components cannot be guaranteed, affecting the long-term performance of the electronic device.

[0088] Figure 6 This is a structural schematic diagram of an appearance component in related technologies. (Refer to...) Figure 6 As shown, taking the back cover of a laptop as an example, the back cover can use a magnesium alloy substrate 11 as the main structural component. A micro-arc oxidation layer 12, a primer layer 13, a color paint layer 14, and a velvety topcoat layer 15 are sequentially formed on the magnesium alloy substrate 11. The thickness of the micro-arc oxidation layer 12 can be 5μm-8μm, the thickness of the primer layer 13 can be 5μm-12μm, the thickness of the color paint layer 14 can be 5μm-12μm, and the thickness of the velvety topcoat layer 15 can be 20μm-40μm. The primer layer 13, the color paint layer 14, and the velvety topcoat layer 15 are all ordinary polyurethane coatings. The velvety topcoat layer 15 is made by adding velvety powder to the polyurethane coating to give it a velvety feel.

[0089] Although the magnesium alloy substrate 11 is lighter than that of ordinary aluminum alloy substrates, thus reducing the weight of the back cover, and the velvety finish 15 gives the back cover a slightly velvety feel, the velvety finish 15 uses a polyurethane coating and incorporates velvety powder to achieve the velvety feel. This results in low cross-linking degree and poor anti-caking effect of the velvety finish 15, leading to poor stain resistance of the back cover. Furthermore, the particle size of the velvety powder added to the velvety finish 15 is typically between 10μm and 80μm, making the slightly velvety feel of the back cover somewhat rough.

[0090] Figure 7 This is a structural schematic diagram of another appearance component in the related art. (Refer to...) Figure 7 As shown, taking the outer part 2 as a protective case for a mobile phone or tablet as an example, the protective case can use an aramid fiber substrate 21 as the main structure. A polishing paint layer 22, a transparent primer layer 23, a middle coat layer 24, and a topcoat layer 25 are sequentially formed on the aramid fiber substrate 21. The thickness of the polishing paint layer 22 can be 8μm-20μm, the thickness of the transparent primer layer 23 can be 5μm-12μm, the thickness of the middle coat layer 24 can be 5μm-12μm, and the thickness of the topcoat layer 25 can be 20μm-40μm. The transparent primer layer 23, the middle coat layer 24, and the topcoat layer 25 are all ordinary polyurethane coatings.

[0091] Although the polyurethane coating on the topcoat layer 25 provides good elasticity and the coating thickness on the aramid fiber substrate 21 is large, resulting in a high yield rate for the protective case, the topcoat layer 25, being solely a polyurethane coating, lacks a silky feel. Furthermore, the topcoat layer 25 relies entirely on the resin's own elasticity for its elasticity, leading to lower cross-linking and poorer stain resistance for the protective case. Additionally, during long-term use, polyurethane hydrolysis can occur, causing the topcoat layer 25 to become sticky to the touch.

[0092] Figure 8 This is a structural schematic diagram of the third type of appearance component in the related technology. (Refer to...) Figure 8 As shown, taking the outer part 3 as a protective case for a mobile phone or tablet as an example, the protective case can use a composite substrate 31 composed of polycarbonate (PC) with 10%-20% glass fiber (GF) as the main structure. A colored paint layer 32 and a matte topcoat layer 33 are sequentially formed on the composite substrate 31. The thickness of the colored paint layer 32 can be 5μm-12μm, and the thickness of the matte topcoat layer 33 can be 15μm-25μm. The colored paint layer 32 can be a common polyurethane coating, and the matte topcoat layer 33 can be a UV topcoat layer formed by ultraviolet (UV) curing.

[0093] Although the matte topcoat layer 33 uses silicone-modified resin for cross-linking and matting powder (fumed silica) for gloss removal, achieving a silky smooth feel and good stain resistance due to its high degree of cross-linking, the silicone-modified resin itself lacks elasticity, resulting in a hard and inelastic paint film on the protective shell. Furthermore, the addition of matting powder to the matte topcoat layer 33 leads to poor light transmittance in the paint film of the protective shell.

[0094] In view of this, this application embodiment improves the coating of appearance components in electronic devices by sequentially setting an intermediate paint layer and a skin-feel topcoat layer on a substrate layer. The intermediate paint layer serves to bond with the substrate layer, develop color, and achieve texture effects, while the skin-feel topcoat layer is used to give the appearance component a skin-feel effect. The raw materials of the skin-feel topcoat layer include silicone-modified acrylate with a molecular weight of 8000-20000 and polyurethane acrylic resin with a molecular weight of 6000-20000. By mixing the two in a ratio of 3:7-9:1 and then sequentially curing them under an excimer lamp and a UV lamp, a nanoscale micro-wrinkled structure can be formed in the skin-feel topcoat layer. Since both the silicone-modified acrylate and the polyurethane acrylic resin used in the skin-feel topcoat layer have high molecular weights, the coating of the appearance component can have good toughness. The silicone-modified acrylate gives the skin-feel topcoat layer a silky feel and good stain resistance, while the polyurethane acrylic resin gives it good elasticity. Furthermore, the nanoscale micro-wrinkled structure gives the skin-feel topcoat layer an ultra-matte appearance. Therefore, while the exterior parts have a silky, elastic feel and an ultra-matte finish, they also have good toughness and stain resistance.

[0095] The following provides a detailed description of the appearance components according to the embodiments of this application. It is understood that an appearance component is a structural component in an electronic device that is at least partially exposed on its surface. For example, an appearance component may be the mid-frame 210 and back cover 220 in the aforementioned mobile phone, or the back cover 620, top cover 711, bottom cover 712, and keycaps of the keyboard 720 in the aforementioned laptop, or the back cover 230 and keycaps of the keyboard 800 in the aforementioned tablet computer, etc., and may also be a protective case for the aforementioned mobile phone, tablet computer, or other electronic devices.

[0096] Figure 9 This is a structural schematic diagram of the first appearance component provided in the embodiments of this application. Figure 10 This is a structural schematic diagram of a second appearance component provided in an embodiment of this application. Figure 11 This is a structural schematic diagram of the third appearance component provided in the embodiments of this application. Figure 12 This is a structural schematic diagram of the fourth appearance component provided in the embodiments of this application. Figure 13 This is a structural schematic diagram of the fifth appearance component provided in the embodiments of this application. Figure 14 This is a structural schematic diagram of the sixth appearance component provided in the embodiments of this application. Figure 15 This is a structural schematic diagram of the seventh appearance component provided in the embodiments of this application. Figure 16 This is a structural schematic diagram of the eighth appearance component provided in the embodiments of this application.

[0097] Reference Figures 9-16As shown in any embodiment, the appearance component 900 includes a substrate layer 910, an intermediate paint layer 920, and a skin-feel topcoat layer 930. The intermediate paint layer 920 and the skin-feel topcoat layer 930 are sequentially disposed on the substrate layer 910, and all paint layers on the substrate layer 910 constitute the overall coating of the appearance component 900. The substrate layer 910 serves as the main structural component of the appearance component 900, ensuring its structural strength and meeting its reliability requirements. The intermediate paint layer 920 is disposed between the substrate layer 910 and the skin-feel topcoat layer 930. The intermediate paint layer 920 serves to bond with the substrate layer 910 and also enriches the color and texture effects of the appearance component 900. The skin-feel topcoat layer 930 is the topcoat layer of the appearance component 900 that is touched by the user. The skin-feel topcoat layer 930 enhances the texture (or tactile feel) of the appearance component 900, giving it a skin-like feel (hereinafter referred to as skin feel).

[0098] Depending on the structural strength, texture, and functional requirements of the appearance component 900, the material of the substrate layer 910 may include magnesium alloy (profile magnesium alloy or die-cast magnesium alloy), polycarbonate (PC), a composite material composed of polycarbonate (PC) with 10%-40% glass fiber (GF), polyamide (PA), a composite material composed of polyamide (PA) with 30%-70% glass fiber (GF), aramid fiber, and thermoplastic polyurethane elastomer rubber (TPU).

[0099] The intermediate paint layer 920 may include a primer layer 921, a color paint layer 922, and a middle paint layer 923. The primer layer 921 can be directly applied to the surface of the substrate layer 910. The color paint layer 922 can be applied over the primer layer 921, or it can be directly applied to the surface of the substrate layer 910. The middle paint layer 923 is typically applied over the primer layer 921.

[0100] The primer layer 921 is used to bond with the substrate layer 910, enhancing the adhesion between the paint layers and improving the fullness and decorative effect of the skin-feel topcoat layer 930. Furthermore, the primer layer 921 typically also possesses properties such as corrosion resistance, moisture resistance, and salt and alkali resistance, protecting the overall coating of the appearance part 900 and extending its service life. In addition, since the primer layer 921 directly covers the surface of the substrate layer 910, it can also compensate for surface defects in the substrate layer 910, enhancing the hiding power of the overall coating composed of all paint layers and improving the appearance of the appearance part 900.

[0101] The color paint layer 922 imparts color to the overall coating, blocks light transmission, and serves to color, cover, and decorate, enhancing the color effect of the appearance component 900. Furthermore, since the color paint layer 922 is formed by adding additives such as colorant and filler to the paint, it can enhance the mechanical and chemical properties of the overall coating. Additionally, when the color paint layer 922 is directly applied to the substrate layer 910, it can also enhance the adhesion of the overall coating and protect it from corrosion, moisture, and salt and alkali.

[0102] A mid-coat layer 923 is disposed between the primer layer 921 and the skin-feel topcoat layer 930. The mid-coat layer 923 needs to have good adhesion to both the paint layers below and above it. The mid-coat layer 923 can firmly adhere to the surface of the paint layer below it (e.g., the primer layer 921) and easily bond with the paint layer above it (e.g., the skin-feel topcoat layer 930). Furthermore, the mid-coat layer 923 can increase the overall coating thickness and improve the overall coating durability. In addition, the mid-coat layer 923 also has leveling properties, eliminating pinholes and textures on the surface of the substrate layer 910 to improve the smoothness of the overall coating and enhance its brightness and fullness.

[0103] The intermediate coat 923 may include a transparent intermediate coat 9231 and a colored intermediate coat 9232. As the name suggests, the transparent intermediate coat 9231 may be transparent and has high light transmittance. The colored intermediate coat 9232 has a color; for example, it may be black or white. The colored intermediate coat 9232 may be opaque or have very low light transmittance.

[0104] For example, the intermediate coat 923 may consist of only one of a transparent intermediate coat 9231 and a colored intermediate coat 9232. Either the transparent intermediate coat 9231 or the colored intermediate coat 9232 is directly applied onto the primer layer 921, and the skin-feel topcoat layer 930 is applied onto either the transparent intermediate coat 9231 or the colored intermediate coat 9232. In this case, the transparent intermediate coat 9231 primarily serves to bond the upper and lower coats. While the colored intermediate coat 9232 also serves a bonding function, it may also impart color to the overall coating.

[0105] Alternatively, the intermediate coat 923 may include both a transparent intermediate coat 9231 and a colored intermediate coat 9232. The colored intermediate coat 9232 can be directly applied onto the primer 921, and the transparent intermediate coat 9231 can be applied onto the colored intermediate coat 9232. In this case, both the colored intermediate coat 9232 and the transparent intermediate coat 9231 serve to bond the upper and lower coats, and the transparent intermediate coat 9231 also protects the colored intermediate coat 9232. In some examples, local areas of the colored intermediate coat 9232 can be removed using laser engraving or other methods to give the exterior part 900 a pattern or texture.

[0106] Specifically, such as Figure 9 As shown in the figure, the substrate layer 910 is used as an example of a metal layer, specifically a magnesium alloy layer 911. Compared to aluminum alloys, magnesium alloys not only have good mechanical properties, but also have a lower weight, which can reduce the weight of the appearance component 900. For example, the magnesium alloy can be a profile magnesium alloy or a die-cast magnesium alloy, such as a semi-solid die-cast magnesium alloy. The appearance component 900, with the substrate layer 910 as the main structural body, is, for example, the back cover 620 of a laptop, the main body cover 711 of a laptop, or the back cover 230 of a tablet computer.

[0107] A micro-arc oxidation layer 9201, a primer layer 921, a color paint layer 922, and a skin-feel topcoat layer 930 are sequentially stacked on a magnesium alloy substrate layer 910. The primer layer 921 and the color paint layer 922 can be polyurethane coatings. The thickness of the micro-arc oxidation layer 9201 can be 4μm-9μm, for example, 4.5μm, 5.0μm, 5.5μm, 6.0μm, 6.5μm, 7.0μm, 7.5μm, 8.0μm, 8.5μm, etc. The thickness of the primer layer 921 can be 4μm-15μm, for example, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the color paint layer 922 can be 4μm-15μm, for example, the thickness of the color paint layer 922 can be 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the skin-feel topcoat layer 930 can be 15μm-40μm, for example, the thickness of the skin-feel topcoat layer 930 can be 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, 32μm, 34μm, 36μm, 38μm, etc.

[0108] It should be noted that when the substrate layer 910 is a metal layer, a micro-arc oxidation layer 9201 is usually formed on the substrate layer 910 before applying the paint layer. Micro-arc oxidation is a surface treatment technology that can form an oxide layer on the surface of the metal substrate layer 910. The micro-arc oxidation layer 9201 can improve the hardness, wear resistance, and corrosion resistance of the substrate layer 910, enhance the adhesion of the paint layer to the substrate layer 910, improve the stability and reliability of the appearance part 900, and extend the service life of the appearance part 900.

[0109] like Figure 10As shown in the figure, the substrate layer 910 is used as an example of a metal layer, specifically a magnesium alloy layer 911. The magnesium alloy can be a profile magnesium alloy or a die-cast magnesium alloy, such as a semi-solid die-cast magnesium alloy. The substrate layer 910 serves as the main structural element 900, such as the back cover 620 of a laptop, the main body cover 711 of a laptop, or the back cover 230 of a tablet computer.

[0110] A micro-arc oxidation layer 9201, a color paint layer 922, and a skin-feel topcoat layer 930 are sequentially stacked on the magnesium alloy layer 911. The color paint layer 922 can be a polyurethane coating. The thickness of the micro-arc oxidation layer 9201 can be 4μm-9μm, for example, 4.5μm, 5.0μm, 5.5μm, 6.0μm, 6.5μm, 7.0μm, 7.5μm, 8.0μm, 8.5μm, etc. The thickness of the color paint layer 922 can be 4μm-15μm, for example, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the skin-feel coating layer 930 can be 15μm-40μm, for example, the thickness of the skin-feel coating layer 930 is 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, 32μm, 34μm, 36μm, 38μm, etc.

[0111] like Figure 11 As shown in the figure, the substrate layer 910 is a polycarbonate layer 912 as an example. The exterior component 900, with this substrate layer 910 as the main structural element, is, for example, the bottom cover 712 of a laptop computer, the keycaps of a keyboard 720, or the protective case of an electronic device 10 such as a mobile phone or tablet computer. A primer layer 921, a colored intermediate coat layer 9232, a transparent intermediate coat layer 9231, and a skin-feel topcoat layer 930 are sequentially layered on the polycarbonate layer 912. The primer layer 921 is, for example, a white primer layer, and the colored intermediate coat layer 9232 is, for example, a black intermediate coat layer. All three layers—primer layer 921, colored intermediate coat layer 9232, and transparent intermediate coat layer 9231—are polyurethane coatings. Specifically, the colored intermediate coat layer 9232 can have light-transmitting holes 92321, which are, for example, laser-engraved holes, to achieve pattern or texture effects on the exterior component 900.

[0112] The thickness of the primer layer 921 can be 4μm-15μm, for example, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the colored intermediate coat layer 9232 can be 4μm-15μm, for example, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the transparent intermediate coat layer 9231 can be 4μm-15μm, for example, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the skin-feel coating layer 930 can be 15μm-40μm, for example, the thickness of the skin-feel coating layer 930 is 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, 32μm, 34μm, 36μm, 38μm, etc.

[0113] like Figure 12 As shown in the figure, the substrate layer 910 is an aramid fiber layer 913 as an example. The substrate layer 910 serves as the main structural element of the exterior component 900, such as a protective case for an electronic device 10 like a mobile phone or tablet. The aramid fiber layer 913 is sequentially layered with a polishing paint layer 9202, a primer layer 921, a transparent intermediate paint layer 9231, and a skin-feel topcoat layer 930. Both the primer layer 921 and the transparent intermediate paint layer 9231 are polyurethane coatings; the primer layer 921 is, for example, a transparent primer layer.

[0114] The thickness of the polishing paint layer 9202 can range from 8μm to 20μm, for example, thicknesses of 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, and 19μm. The thickness of the primer layer 921 can range from 4μm to 15μm, for example, thicknesses of 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, and 14μm. The thickness of the transparent intermediate coat layer 9231 can range from 4μm to 15μm, for example, thicknesses of 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, and 14μm. The thickness of the skin-feel coating layer 930 can be 15μm-40μm, for example, the thickness of the skin-feel coating layer 930 is 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, 32μm, 34μm, 36μm, 38μm, etc.

[0115] It should be noted that when the substrate layer 910 is made of aramid fiber layer 913, a polishing paint layer 9202 is usually applied to the substrate layer 910 before applying the primer layer 921. After applying the polishing paint layer 9202, it can be polished 1-3 times. Then, the primer layer 921 is applied on the polishing paint layer 9202. By setting the polishing paint layer 9202 on the aramid fiber layer 913, the polishing paint layer 9202 can fill the surface defects such as pits, protrusions, gaps, and burrs of the aramid fiber layer 913, improving the smoothness and fineness of the appearance part 900 and enhancing its appearance. Furthermore, by polishing the polishing paint layer, the roughness of the polishing paint layer 9202 can be increased, improving the adhesion of the primer layer 921 to the polishing paint layer 9202. This, in turn, improves the overall mechanical properties and reliability of the coating.

[0116] like Figure 13 As shown in the figure, the substrate layer 910 is a composite material made of polycarbonate (PC) with 10%-20% glass fiber (GF) added, which serves as an example. The substrate layer 910 is a composite material layer 914 made of the above materials. This substrate layer 910 serves as the main structural element 900, such as the mid-frame 210 of a mobile phone, or a protective case for electronic devices 10 such as mobile phones and tablets. A color paint layer 922 and a skin-feel coating layer 930 are sequentially disposed on the composite material layer 914. The color paint layer 922 is a polyurethane coating.

[0117] The thickness of the color paint layer 922 can be 4μm-15μm, for example, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the skin-feel coating layer 930 can be 15μm-40μm, for example, 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, 32μm, 34μm, 36μm, 38μm, etc.

[0118] like Figure 14 As shown in the figure, the substrate layer 910 is a composite material made of polyamide (PA) with 30%-70% glass fiber (GF) added, which is taken as an example. The substrate layer 910 is a composite material layer 914 made of the above materials. The outer part 900 with this substrate layer 910 as the main structure is, for example, the middle frame 210 of a mobile phone, the back cover 220 of a mobile phone, the back cover 620 of a laptop computer, and the back cover 230 of a tablet computer.

[0119] The composite material layer 914 is sequentially provided with a primer layer 921, a color paint layer 922, and a skin-feel topcoat layer 930. The primer layer 921 and the color paint layer 922 are polyurethane coatings. A solid color paint layer 9203 can also be applied over the primer layer 921, and the color paint layer 922 can be applied over the solid color paint layer 9203. Solid color paint, also called plain color paint, is a colored paint with hiding power. The hiding power in solid color paint comes from organic and inorganic pigments.

[0120] The thickness of the primer layer 921, or the total thickness of the primer layer 921 and the solid color paint layer 9203, can be 4μm-15μm. For example, the thickness of the primer layer 921 or the total thickness of the primer layer 921 and the solid color paint layer 9203 can be 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the color paint layer 922 can be 4μm-15μm. For example, the thickness of the color paint layer 922 can be 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the skin-feel coating layer 930 can be 15μm-40μm, for example, the thickness of the skin-feel coating layer 930 is 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, 32μm, 34μm, 36μm, 38μm, etc.

[0121] like Figure 15 As shown in the figure, the material of the substrate layer 910 is thermoplastic polyurethane elastomer rubber (TPU), and the substrate layer 910 is a TPU layer 915. This substrate layer 910 serves as the main structural element 900, for example, a protective case for electronic devices 10 such as mobile phones and tablets. A primer layer 921 and a skin-feel topcoat layer 930 are sequentially disposed on the TPU layer 915. The primer layer 921 is a polyurethane coating. A solid color paint layer 9203 can also be coated on the primer layer 921, and the skin-feel topcoat layer 930 is coated on top of the solid color paint layer 9203.

[0122] The thickness of the primer layer 921, or the total thickness of the primer layer 921 and the solid color paint layer 9203, can be 4μm-15μm. For example, the thickness of the primer layer 921 or the total thickness of the primer layer 921 and the solid color paint layer 9203 can be 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the skin-feel topcoat layer 930 can be 15μm-40μm. For example, the thickness of the skin-feel topcoat layer 930 can be 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, 32μm, 34μm, 36μm, 38μm, etc.

[0123] like Figure 16As shown in the figure, the material of the substrate layer 910 is thermoplastic polyurethane elastomer rubber (TPU), and the substrate layer 910 is a TPU layer 915. This substrate layer 910 serves as the main structural element 900, such as a protective case for electronic devices 10 like mobile phones and tablets. A primer layer 921, a color paint layer 922, and a skin-feel topcoat layer 930 are sequentially disposed on the TPU layer 915. The primer layer 921 and the color paint layer 922 are polyurethane coatings. A solid color paint layer 9203 can also be coated on the primer layer 921, and the color paint layer 922 can be coated on top of the solid color paint layer 9203.

[0124] The thickness of the primer layer 921, or the total thickness of the primer layer 921 and the solid color paint layer 9203, can be 4μm-15μm. For example, the thickness of the primer layer 921 or the total thickness of the primer layer 921 and the solid color paint layer 9203 can be 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the color paint layer 922 can be 4μm-15μm. For example, the thickness of the color paint layer 922 can be 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, etc. The thickness of the skin-feel coating layer 930 can be 15μm-40μm, for example, the thickness of the skin-feel coating layer 930 is 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm, 32μm, 34μm, 36μm, 38μm, etc.

[0125] In this embodiment, the raw materials for the skin-feel topcoat layer 930 include high molecular weight silicone-modified acrylate and high molecular weight polyurethane acrylic resin. The high molecular weight silicone-modified acrylate and high molecular weight polyurethane acrylic resin are mixed in a certain proportion to form a topcoat coating. This topcoat coating is then applied to the surface of the intermediate paint layer 920 to form a topcoat layer. The topcoat layer is then sequentially cured under an excimer lamp and a UV lamp. The silicone-modified acrylate and polyurethane acrylic resin undergo a chemical reaction, causing the topcoat layer to cure and form the skin-feel topcoat layer 930, ensuring that the skin-feel topcoat layer 930 is stably and reliably adhered to the intermediate paint layer 920.

[0126] The molecular weight of the silicone-modified acrylate can be 8000-20000, and the molecular weight of the polyurethane acrylic resin can be 6000-20000. This ensures that both the silicone-modified acrylate and the polyurethane acrylic resin have sufficiently large molecular weights to form a skin-feel coating layer 930 with good toughness, preventing cracking and ensuring the integrity and smoothness of the skin-feel coating layer 930, thus improving the appearance of the exterior part 900. Furthermore, it also avoids the silicone-modified acrylate and polyurethane acrylic resin having excessively large molecular weights, which could prevent them from failing to produce an effective chemical reaction and thus hinder the formation of a stable skin-feel coating layer 930.

[0127] For example, the molecular weight of silicone-modified acrylates can be 8000-10000. Examples include molecular weights of 8200, 8400, 8600, 8800, 9000, 9200, 9400, 9600, and 9800. The molecular weight of polyurethane acrylic resins can be 6000-10000. Examples include molecular weights of 6500, 7000, 7500, 8000, 8500, 9000, and 9500.

[0128] Both silicone-modified acrylates and polyurethane acrylic resins possess functional groups (or double bonds). When they are mixed and cured, a chemical reaction occurs, breaking the double bonds in the monomers and bonding between them. High molecular weight silicone-modified acrylates exhibit high functionality; for example, their functionality can be 5 or 6, or even 9, 10, or higher. In contrast, high molecular weight polyurethane acrylic resins have lower functionality, typically 2 or 3.

[0129] A high molecular weight silicone-modified acrylate and a high molecular weight polyurethane acrylic resin are mixed to form a topcoat. This topcoat is then applied to the surface of the intermediate paint layer 920 to form a topcoat coating. The topcoat coating is first irradiated with an excimer lamp to partially cure it. Then, it is irradiated with an ultraviolet lamp to fully cure it, forming a skin-feel topcoat layer 930.

[0130] The excimer lamp emits near-ultraviolet light, which has good penetrating power on the surface of the topcoat coating, causing a chemical reaction on the surface while the inner layer remains uncured. At this point, the surface of the topcoat shrinks, creating a stress difference between the surface and inner layers, resulting in micro-wrinkles within the coating. The topcoat is then fully cured by ultraviolet light emitted from the ultraviolet lamp. Even after complete curing, the internal micro-wrinkles remain, forming a stable and reliable skin-feel topcoat layer 930 on the outer surface of the exterior part 900.

[0131] In this embodiment, the ratio of high molecular weight silicone-modified acrylate and high molecular weight polyurethane acrylic resin is controlled to control the ratio of high-functionality resin and low-functionality resin in the topcoat. Furthermore, during excimer lamp curing of the topcoat coating, the curing shrinkage ratio of the topcoat coating can be controlled to form a micro-wrinkled structure of suitable size in the skin-feel topcoat layer 930.

[0132] Figure 17 SEM comparison images of the skin-feel coating layer and the ordinary skin-feel coating layer provided in the embodiments of this application. (Refer to...) Figure 17 As shown, Figure 17 (a) shows the microstructure of a typical tactile coating layer as captured by a scanning electron microscope (SEM). It can be seen that the typical tactile coating layer is in a uniform cross-linked state. Figure 17 (b) shows the microstructure of the skin-feel coating layer 930 of this embodiment of the application as captured by a scanning electron microscope at the same magnification. It can be seen that the skin-feel coating layer 930 of this embodiment has a micro-wrinkle structure 9301.

[0133] In this embodiment, the ratio of high molecular weight silicone-modified acrylate to high molecular weight polyurethane acrylic resin can be controlled between 3:7 and 9:1. This avoids both an excessively high proportion of high-functionality resin in the topcoat, preventing excessive shrinkage of the topcoat layer and preventing the formation of micro-wrinkled structures 9301 in the skin-feel topcoat layer 930 to reach the micrometer scale, and an excessively high proportion of low-functionality resin in the topcoat, preventing insufficient shrinkage of the topcoat layer and ensuring effective formation of micro-wrinkled structures 9301 in the skin-feel topcoat layer 930. With this setting, the appropriate ratio of high-functionality to low-functionality resin in the topcoat allows the micro-wrinkled structures 9301 formed in the skin-feel topcoat layer 930 to reach the nanometer scale.

[0134] In other words, by controlling the ratio of high-functionality resin to low-functionality resin between 3:7 and 9:1, a nanoscale micro-wrinkled structure 9301 is formed in the skin-feel coating layer 930. This nanoscale micro-wrinkled structure 9301 enables the skin-feel coating layer 930 to truly achieve a skin-feel texture. The presence of the micro-wrinkled structure 9301 causes diffuse reflection of light within the skin-feel coating layer 930, giving it an ultra-matte appearance.

[0135] High molecular weight silicone-modified acrylate and high molecular weight polyurethane acrylic resin are cured and cross-linked to form a high molecular weight skin-feel topcoat layer 930. This skin-feel topcoat layer 930 has a nanoscale micro-wrinkled structure 9301, and the properties of the polyurethane acrylic resin give the skin-feel topcoat layer 930 an elastic feel, while the properties of the silicone acrylate give it a silky smooth feel. Therefore, the nanoscale micro-wrinkled structure 9301 in the skin-feel topcoat layer 930, combined with the elasticity and silky smoothness of the skin-feel topcoat layer 930, allows the exterior part 900 to achieve a baby-like skin-feel experience.

[0136] Furthermore, the high molecular weight silicone-modified acrylate and high molecular weight polyurethane acrylic resin are cured and cross-linked to form a high molecular weight skin-feel topcoat layer 930 with good toughness, ensuring the reliability and durability of the skin-feel topcoat layer 930 and extending the overall service life of the coating of the appearance part 900. In addition, the addition of silicone-modified acrylate gives the skin-feel topcoat layer 930 excellent stain resistance, which can improve the user experience of the appearance part 900 and extend its service life.

[0137] In some embodiments, before the skin-feel topcoat layer 930 cures, that is, during the process of mixing high molecular weight silicone-modified acrylate and high molecular weight polyurethane acrylic resin to form the topcoat, a trace amount of pearlescent powder (or matte powder) can be added to the topcoat. The proportion of pearlescent powder (or matte powder) in the topcoat can be less than or equal to 0.5% to give the skin-feel topcoat layer 930 a brighter matte finish.

[0138] Figure 18 SEM results for the skin-feel coating layer provided in the embodiments of this application. (Refer to...) Figure 18 As shown in the figure, the microstructure of the skin-feel coating layer 930 of this embodiment of the application is captured by scanning electron microscopy at a higher magnification. The dimensions of the micro-wrinkle structure 9301 in the skin-feel coating layer 930 are measured in the figure. Specifically, the width of the micro-wrinkle structure 9301 in the planar direction of the skin-feel coating layer 930 is measured.

[0139] Depend on Figure 18The measurement results show that, by measuring the micro-wrinkled structures 9301 at different locations of the skin-feel coating layer 930, the width of the micro-wrinkled structures 9301 in this embodiment is 5nm-50nm. In other words, the width of the micro-wrinkled structures 9301 is between 5nm and 50nm. The figure shows four micro-wrinkled structures 9301 in the skin-feel coating layer 930: one with a very small width, one with a moderate width, and one with a very large width. Thus, measurements were taken for the micro-wrinkled structures 9301 with extremely small, extremely large, and moderate widths, allowing for a precise determination of the width range of the micro-wrinkled structures 9301. The widths of the four measured micro-wrinkled structures 9301, from smallest to largest, are 7.15nm, 8.72nm, 11.17nm, and 14.56nm, respectively. Therefore, it can be seen that nanoscale micro-wrinkled structures 9301 are formed in the skin-feel coating layer 930 of this embodiment.

[0140] Among them, by Figure 18 The scanning results show that among the four measured micro-wrinkle structures 9301, the widest micro-wrinkle structure 9301 in the skin-feel coating layer 930 is 14.56 nm wide. In other words, the width of the micro-wrinkle structure 9301 in the skin-feel coating layer 930 of this embodiment is between 5 nm and 20 nm. Thus, in the skin-feel coating layer 930 of this embodiment, the overall width of the micro-wrinkle structure 9301 is more concentrated, the overall width of the micro-wrinkle structure 9301 is more uniform, and the dimensions of the micro-wrinkle structure 9301 are more refined, achieving a more refined skin-feel effect.

[0141] Furthermore, in this embodiment, by controlling the ratio of high molecular weight silicone-modified acrylate to high molecular weight polyurethane acrylic resin between 3:7 and 9:1, the width of the micro-wrinkled structure 9301 formed in the skin-feel coating layer 930 is controlled between 5 nm and 20 nm. Furthermore, the cross-sectional dimension of the micro-wrinkled structure 9301 in the thickness direction of the skin-feel coating layer 930 can be controlled to within 8 μm. In other words, the cross-sectional thickness of the micro-wrinkled structure 9301 in the thickness direction of the skin-feel coating layer 930 can be less than or equal to 8 μm.

[0142] If the cross-sectional thickness of the micro-wrinkled structure 9301 is too large, it will occupy too much space in the thickness direction of the skin-feel coating layer 930, easily causing the skin-feel coating layer 930 to crack and affecting its integrity and stability. As mentioned above, the overall thickness of the skin-feel coating layer 930 is between 15μm and 40μm. In this embodiment, the cross-sectional thickness of the micro-wrinkled structure 9301 is controlled within 8μm, resulting in a smaller space occupied by the micro-wrinkled structure 9301 in the thickness direction of the skin-feel coating layer 930. While achieving a realistic skin-feel effect, cracking of the skin-feel coating layer 930 can be avoided, ensuring its integrity and stability.

[0143] In some embodiments, the cross-sectional dimension of the micro-wrinkled structure 9301 in the thickness direction of the skin-feel coating layer 930 can be less than or equal to 6.5 μm. In other words, the cross-sectional thickness of the micro-wrinkled structure 9301 is within 6.5 μm. Thus, the space occupied by the micro-wrinkled structure 9301 in the thickness direction of the skin-feel coating layer 930 is less than half, which can effectively prevent the skin-feel coating layer 930 from becoming brittle, improve the integrity and stability of the skin-feel coating layer 930, and ensure the reliability of the skin-feel coating layer 930.

[0144] Figure 19 SEM results of the micro-wrinkle structure in the skin-feel coating layer provided in the embodiments of this application. (Refer to...) Figure 19 As shown in the figure, the microstructure of the skin-feel coating layer 930 in the embodiment of this application is shown by scanning electron microscopy, specifically the cross-sectional structure of the micro-wrinkle structure 9301 in the thickness direction of the skin-feel coating layer 930.

[0145] Depend on Figure 19 The scan results show that Figure 19 (a) A section of micro-folded structure 9301 with relatively uniform undulation is measured. By measuring the height difference between the highest and lowest points of the micro-folded structure 9301, the overall cross-sectional thickness of the micro-folded structure 9301 is 3.498 μm. Figure 19 (b) A section of micro-folded structure 9301 with varying undulations and steep and gentle slopes was measured. The height difference between the highest and lowest points of different sections of the micro-folded structure 9301 was measured. In the micro-folded structure 9301, the profile thickness of the gentlest section was 312.6 nm, the profile thickness of the steepest section was 1.898 μm, and the profile thickness of a section with undulations between the gentlest and steepest sections was 960.2 nm. Figure 19(c) In this paper, a section of micro-folded structure 9301 with large fluctuations is measured. By measuring the height difference between the highest and lowest points of the micro-folded structure 9301, the overall cross-sectional thickness of the micro-folded structure 9301 is 6.029 μm.

[0146] Figure 20 The friction coefficient test results for the skin-feel coating layer provided in the embodiments of this application. (Refer to...) Figure 20 As shown, in this embodiment, the coefficient of friction of the skin-feel topcoat layer 930 was also tested using an FPT-F1 friction coefficient / peel tester. Among other things, Figure 20 The test conditions for (a) are: force 0.173 N, displacement 50.0 mm, time 36.1 s, temperature 24.1 ℃, and number of friction cycles 9. Under these test conditions, the static friction coefficient of the skin-feel coating layer 930 is 0.212 and the dynamic friction coefficient is 0.095. Figure 20 The test conditions in (b) are: force 0.143N, displacement 50.0mm, time 36.2s, temperature 24.0℃, and number of friction cycles 5. Under these test conditions, the static friction coefficient of the skin-feel coating layer 930 was detected to be 0.203 and the dynamic friction coefficient was 0.117.

[0147] Therefore, the coefficient of kinetic friction of the skin-feel coating layer 930 in this embodiment is less than or equal to 0.12, or in other words, the coefficient of kinetic friction of the skin-feel coating layer 930 is below 0.12. Specifically, the coefficient of kinetic friction of the skin-feel coating layer 930 can be between 0.09 and 0.12. That is to say, the coefficient of kinetic friction of the skin-feel coating layer 930 is very small, the surface roughness of the skin-feel coating layer 930 is very low, and the surface of the skin-feel coating layer 930 is very smooth. The touch of the skin-feel coating layer 930 truly achieves a silky smooth feel, reaching a baby-like skin-feeling experience.

[0148] In addition, this embodiment can also control the ratio of high-functionality silicone-modified acrylate and low-functionality polyurethane acrylic resin in the skin-feel coating layer 930 according to the application scenario and material of the appearance part 900, so as to meet the performance requirements of different appearance parts 900.

[0149] In scenarios where the exterior component 900 is used, such as as a keycap on a laptop keyboard 720 or a tablet keyboard 800, the keycap uses, for example, the aforementioned polycarbonate layer 912 as the base layer 910. The exterior component 900 is protected by a shell structure, and it does not require protection against sharp edges, drops, or bending. Taking keyboard keycaps as an example, the focus is more on wear resistance.

[0150] At this point, in the skin-feel coating layer 930, the ratio of high-functionality silicone-modified acrylate to low-functionality polyurethane acrylic resin can be slightly higher, the curing shrinkage ratio of the skin-feel coating layer 930 can be slightly higher, the number of micro-wrinkled structures 9301 in the skin-feel coating layer 930 can be slightly greater, and the width of the micro-wrinkled structures 9301 can be slightly larger. For example, the ratio of high-functionality silicone-modified acrylate to low-functionality polyurethane acrylic resin can be between 9:1 and 8:2.

[0151] When the exterior component 900 is used in scenarios with high risk requirements, it has performance requirements such as edge drop and impact resistance. For example, the exterior component 900 is the mid-frame 210 and back cover 220 of a mobile phone, the back cover 620 or top cover 711 and bottom cover 712 of a laptop, and the back cover 230 of a tablet computer. The base layer 910 of the exterior component 900 can be made of magnesium alloy layer 911, polycarbonate layer 912, composite material layer 914 made of polycarbonate with 10%-40% glass fiber, or composite material layer 914 made of polyamide with 30%-70% glass fiber, etc. Alternatively, the outer casing 900 can be a protective case for electronic devices 10 such as mobile phones and tablets. The base layer 910 of the outer casing 900 can be made of aramid fiber layer 913, polycarbonate layer 912, composite material layer 914 made of polycarbonate with 10%-40% glass fiber, or composite material layer 914 made of polyamide with 30%-70% glass fiber.

[0152] At this point, in the skin-feel coating layer 930, the ratio of high-functionality silicone-modified acrylate to low-functionality polyurethane acrylic resin can be nearly balanced, and the curing shrinkage ratio of the skin-feel coating layer 930 is moderate. The number of micro-wrinkled structures 9301 in the skin-feel coating layer 930 can be slightly reduced, and the width of the micro-wrinkled structures 9301 can be slightly smaller. This ensures that the skin-feel coating layer 930 has sufficient toughness to meet the risk performance requirements of the appearance part 900. For example, the ratio of high-functionality silicone-modified acrylate to low-functionality polyurethane acrylic resin can be between 8:2 and 5:5.

[0153] When the outer component 900 is used in scenarios requiring high bending performance, high toughness and greater resistance to bending are required. For example, if the outer component 900 is a protective case for electronic devices 10 such as mobile phones and tablets, the base material layer 910 of the outer component 900 can be the aforementioned TPU layer 915. Protective cases using TPU layer 915 as the base material layer 910 need high toughness and good bending performance, typically requiring the protective case to not crack when folded.

[0154] At this point, the amount of high-functionality resin in the skin-feel coating layer 930 should not be too high, and the ratio of high-functionality silicone-modified acrylate to low-functionality polyurethane acrylic resin can be slightly smaller to reduce the curing shrinkage ratio of the skin-feel coating layer 930. The number of micro-wrinkled structures 9301 in the skin-feel coating layer 930 can be reduced, and the width of the micro-wrinkled structures 9301 can be smaller. This allows the skin-feel coating layer 930 to have higher toughness, ensuring that it does not crack under bending conditions, thus meeting the bending resistance requirements of the appearance part 900. For example, the ratio of high-functionality silicone-modified acrylate to low-functionality polyurethane acrylic resin can be between 5:5 and 3:7.

[0155] This application also provides a method for manufacturing an appearance part 900, which is used to manufacture the appearance part 900 provided in this embodiment. The appearance part 900 manufactured by this method has a silky, elastic skin-feel effect and an ultra-matte appearance effect, while also having good toughness and stain resistance.

[0156] Figure 21 A flowchart illustrating the steps of a method for manufacturing an exterior component according to an embodiment of this application. (Refer to...) Figure 21 As shown, the manufacturing method of the appearance part 900 provided in this application embodiment includes the following steps:

[0157] S100, provides a substrate layer.

[0158] First, a substrate layer 910 is provided for the appearance component 900. Depending on the structural strength, texture, and functional requirements of the appearance component 900, the material of the substrate layer 910 may include magnesium alloy (profile magnesium alloy or die-cast magnesium alloy), polycarbonate, a composite material of polycarbonate containing 10%-40% glass fiber, polyamide, a composite material of polyamide containing 30%-70% glass fiber, aramid fiber, thermoplastic polyurethane elastomer rubber (TPU), etc.

[0159] For example, when the exterior component 900 is the mid-frame 210, back cover 220 of a machine, the back cover 620 of a laptop, or the top cover 711 and bottom cover 712 of a host, or the back cover 230 of a tablet computer, the base layer 910 of the exterior component 900 can be made of magnesium alloy layer 911, polycarbonate layer 912, composite material layer 914 made of polycarbonate with 10%-40% glass fiber added, or composite material layer 914 made of polyamide with 30%-70% glass fiber added. When the exterior component 900 is a keycap on the keyboard 720 of a laptop or a keycap on the keyboard 800 of a tablet computer, the base layer 910 of the exterior component 900 can be made of polycarbonate. When the outer casing 900 is a protective case for electronic devices 10 such as mobile phones and tablets, the base material layer 910 of the outer casing 900 can be made of aramid fiber, polycarbonate, a composite material made of polycarbonate with 10%-40% glass fiber, a composite material made of polyamide with 30%-70% glass fiber, thermoplastic polyurethane elastomer rubber (TPU), etc.

[0160] S200, an intermediate paint layer is formed on the substrate layer.

[0161] After preparing the substrate layer 910, the next step is to apply the intermediate paint layer 920 required for the appearance part 900 onto the substrate layer 910. The intermediate paint layer 920 may include a primer layer 921, a color paint layer 922, and a middle paint layer 923. Depending on the performance, color, and texture requirements of the appearance part 900, the intermediate paint layer 920 applied to the substrate layer 910 may consist of only one layer or at least two layers stacked sequentially.

[0162] When the intermediate paint layer 920 includes a primer layer 921, the primer layer 921 typically serves as the bottom layer of the overall coating and can be applied first to the substrate layer 910. It should be noted that for some substrate layers 910, surface treatment can be performed before applying the primer layer 921. For example, when the substrate layer 910 is a metal layer, a micro-arc oxidation layer 9201 can be formed on the substrate layer 910 before applying the primer layer 921, and then the primer layer 921 can be applied over the micro-arc oxidation layer 9201. When the substrate layer 910 is made of aramid fiber layer 913, before applying the primer layer 921 to the substrate layer 910, a sanding paint layer 9202 can be applied to the substrate layer 910, and the sanding paint layer 9202 can be sanded 1-3 times. After that, the primer layer 921 can be applied to the sanding paint layer 9202.

[0163] If the intermediate paint layer 920 includes other paint layers besides the primer layer 921, these other paint layers can be sequentially applied onto the primer layer 921. For example, if the intermediate paint layer 920 also includes a mid-coat layer 923, the mid-coat layer 923 can be applied onto the primer layer 921, for example, a colored mid-coat layer 9232 and a transparent mid-coat layer 9231 can be sequentially applied onto the primer layer 921. Alternatively, if the intermediate paint layer 920 also includes a colored paint layer 922, the colored paint layer 922 can be applied onto the primer layer 921. In some embodiments, a solid color paint layer 9203 can also be added to the overall coating of the appearance component 900. The solid color paint layer 9203 can be applied onto the primer layer 921, and other paint layers can be sequentially applied onto the solid color paint layer 9203.

[0164] When the intermediate paint layer 920 does not include the primer layer 921, the color paint layer 922 can be directly applied to the substrate layer 910. Of course, for some substrate layers 910 made of different materials, surface treatment can be performed on the substrate layer 910 before applying the color paint layer 922. For example, when the substrate layer 910 is a metal layer, a micro-arc oxidation layer 9201 can be formed on the substrate layer 910 first, and then the color paint layer 922 can be applied on the micro-arc oxidation layer 9201. When the substrate layer 910 is an aramid fiber layer 913, a polishing paint layer 9202 is applied to the substrate layer 910, and after polishing the polishing paint layer 9202 1-3 times, the color paint layer 922 is applied on the polishing paint layer 9202.

[0165] S300, A skin-feel topcoat layer is formed on the intermediate paint layer.

[0166] After the intermediate paint layer 920 is formed on the substrate layer 910, the next step is to form the skin-feel topcoat layer 930 on the intermediate paint layer 920.

[0167] Figure 22 This is a flowchart illustrating the steps involved in forming a skin-feel topcoat layer on an intermediate paint layer, as provided in an embodiment of this application. (Refer to...) Figure 22 As shown, a skin-feel topcoat layer 930 is formed on the intermediate paint layer 920, specifically including the following steps:

[0168] S310. A silicone-modified acrylate with a molecular weight of 8000-20000 and a polyurethane acrylic resin with a molecular weight of 6000-20000 are mixed in a ratio of 3:7-9:1 to form a topcoat.

[0169] The molecular weight of the silicone-modified acrylate can be between 8,000 and 10,000, and the molecular weight of the polyurethane acrylic resin can be between 6,000 and 10,000. Furthermore, in this embodiment, the ratio of high-functionality silicone-modified acrylate to low-functionality polyurethane acrylic resin in the skin-feel coating layer 930 can be controlled according to the application scenario and material of the appearance part 900.

[0170] When the appearance component 900 is used in scenarios with low-risk requirements, such as when the appearance component 900 is a keycap on a laptop keyboard 720 or a keyboard 800 configured for a tablet computer, the keycap uses, for example, the aforementioned polycarbonate layer 912 as the substrate layer 910. In this case, the ratio of high-functionality silicone-modified acrylate to low-functionality polyurethane acrylic resin can be between 9:1 and 8:2.

[0171] When the exterior component 900 is used in scenarios with high risk requirements, it has performance requirements such as edge drop and impact resistance. For example, the exterior component 900 is the mid-frame 210 and back cover 220 of a mobile phone, the back cover 620 or top cover 711 and bottom cover 712 of a laptop, and the back cover 230 of a tablet computer. The base layer 910 of the exterior component 900 can be made of magnesium alloy layer 911, polycarbonate layer 912, composite material layer 914 made of polycarbonate with 10%-40% glass fiber, or composite material layer 914 made of polyamide with 30%-70% glass fiber, etc. Alternatively, the outer casing 900 can be a protective case for electronic devices 10 such as mobile phones and tablets. The base layer 910 of the outer casing 900 can be made of aramid fiber layer 913, polycarbonate layer 912, composite material layer 914 composed of polycarbonate with 10%-40% glass fiber, or composite material layer 914 composed of polyamide with 30%-70% glass fiber. In this case, the ratio of high-functionality silicone-modified acrylate to low-functionality polyurethane acrylic resin can be between 8:2 and 5:5.

[0172] When the outer component 900 is used in scenarios requiring high bending performance, high toughness and greater resistance to bending are required. For example, if the outer component 900 is a protective case for electronic devices 10 such as mobile phones and tablets, the substrate layer 910 of the outer component 900 can be the aforementioned TPU layer 915. In this case, the ratio of high-functionality silicone-modified acrylate to low-functionality polyurethane acrylic resin can be between 5:5 and 3:7.

[0173] S320. Apply the topcoat paint to the surface of the intermediate paint layer to form a topcoat coating.

[0174] S330. Use an excimer lamp to irradiate the topcoat coating to partially cure it.

[0175] The process can be carried out in a protective gas atmosphere, such as a nitrogen atmosphere, using an excimer lamp to cure the topcoat coating.

[0176] Excimer lamps emit near-ultraviolet light, typically with a wavelength range of 100nm-280nm, with 172nm or 254nm being the most commonly used wavelengths. Near-ultraviolet light has good penetration into the surface of the topcoat, causing a chemical reaction on its surface while leaving the inner layers uncured. This causes the surface of the topcoat to shrink, creating a stress difference between the surface and inner layers, which in turn generates micro-wrinkles within the topcoat.

[0177] By controlling the ratio of high-functionality silicone-modified acrylate to low-functionality polyurethane acrylic resin between 3:7 and 9:1, the size of the micro-wrinkled structure 9301 formed in the skin-feel coating layer 930 can reach the nanoscale. In other words, nanoscale micro-wrinkled structures 9301 can be formed in the skin-feel coating layer 930. The width of the micro-wrinkled structure 9301 is in the range of 5nm-50nm, for example, the width of the micro-wrinkled structure 9301 reaches 5nm-20nm.

[0178] S340. Use ultraviolet light to irradiate the topcoat coating to fully cure it and form a skin-feel topcoat layer.

[0179] For example, a high-pressure mercury lamp can be used as the ultraviolet lamp. The ultraviolet light emitted by the lamp can completely cure the topcoat coating, forming a skin-feeling topcoat layer 930 with strong adhesion and reliable stability on the outer surface of the exterior part 900. After the topcoat coating is fully cured, the internal micro-wrinkle structure 9301 still exists.

[0180] The skin-feel coating layer 930 contains a nanoscale micro-wrinkled structure 9301. The properties of the polyurethane acrylic resin give the skin-feel coating layer 930 an elastic feel, while the properties of the silicone acrylate give it a silky smooth feel. Therefore, the nanoscale micro-wrinkled structure 9301 in the skin-feel coating layer 930, combined with its elasticity and silky smoothness, allows the exterior part 900 to achieve a baby-like skin-feel experience.

[0181] After the topcoat is applied onto the intermediate paint layer 920 to form the topcoat coating, before irradiating the topcoat coating with an excimer lamp, the entire topcoat coating, including the exterior component 900, is typically placed in an oven and baked at a preset temperature for a predetermined time to remove moisture from the topcoat and fix it onto the exterior component 900. For example, the preset baking temperature can be 50℃-60℃, and the preset baking time can be 3min-5min.

[0182] After baking the topcoat, an LED lamp can be used to irradiate the topcoat for pre-curing. The wavelength range of the LED lamp is 45nm-600nm. The main purpose of using an LED lamp to pre-cur the topcoat is to dry it, which is beneficial for subsequent curing with an excimer lamp.

[0183] Specifically Figure 9 Taking the layered structure of the exterior component 900 shown as an example, a magnesium alloy layer 911 is first provided as a substrate layer 910, and then a micro-arc oxidation layer 9201 is formed on the magnesium alloy layer 911. For example, after preparing the magnesium alloy profile, the magnesium alloy profile is sequentially subjected to degreasing, water washing, removal of the surface film (surface film layer), water washing, neutralization, water washing, micro-arc oxidation, water washing, hot water washing, drying, and baking, and the magnesium alloy profile is then inspected.

[0184] The micro-arc oxidation process utilizes an electrolyte primarily composed of silicates mixed with phosphates. The current density is 1A-2A, the electrolyte temperature is ≤30℃, the duty cycle of the electrolytic cell is 10-20%, the frequency is 300-500Hz, and the time is 15min. The tested micro-arc oxidation layer 9201 has a film thickness of 4μm-9μm, a resistivity ≥3 megohms, a surface roughness ≥40A, a porosity ≤10%, and a pore size ≤20μm.

[0185] After forming a micro-arc oxidation layer 9201 on the magnesium alloy layer 911, a primer layer 921 is applied onto the micro-arc oxidation layer 9201. This primer layer 921 can be made by adding a silane coupling agent to an epoxy resin or polyester resin, and an appropriate colorant can be added according to the appearance color requirements of the exterior part 900. The primer layer 921 with a thickness of 4μm-15μm is formed by baking at a temperature of 70℃-80℃ for 8-15 minutes.

[0186] Then, a color paint layer 922 is applied over the primer layer 921. This color paint layer 922 can be made by adding fillers such as talc, color paste, and pearlescent powder to a low-hydroxy acrylic resin, allowing the hydroxy acrylic resin to react with an isocyanate curing agent. The mixture is then baked at 70℃-80℃ for 10-20 minutes to form a color paint layer 922 with a thickness of 4μm-15μm.

[0187] Finally, a topcoat is applied over the 922 color paint layer and baked at 50℃-60℃ for 3-5 minutes to form a topcoat coating with a thickness of 15μm-40μm. The topcoat coating is pre-cured under an LED lamp with a wavelength of 395nm. Then, under a nitrogen atmosphere, the topcoat coating is cured using an excimer lamp with a wavelength of 172nm or 254nm, curing the surface layer of the topcoat coating while leaving the inner layers uncured. Finally, it is cured at an energy of 600mJ / cm². 2 -800mJ / cm2 The power is 80mw / cm 2 -120mw / cm 2 Under high-pressure mercury lamps (ultraviolet lamps), the topcoat coating is fully cured to form a skin-feel topcoat layer 930.

[0188] An environmental test was conducted on an exterior part 900 with a skin-feel coating layer 930 formed on it. The exterior part 900 was baked at 70℃-80℃ for 4-6 hours, and then boiled in water at 80℃ for 30 minutes. The environmental tests showed that the appearance of the exterior part 900 remained unchanged, and the overall coating adhesion was ≥4B. The exterior part 900 met the coating test requirements for the entire electronic device 10, including high temperature and high humidity, and salt spray tests.

[0189] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0190] The terms "first," "second," "third," "fourth," etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

Claims

1. An appearance piece having a skin feel, characterized by, The skin-sensing surface paint layer comprises organic silicon modified acrylate with a molecular weight of 8000-20000 and polyurethane acrylate resin with a molecular weight of 6000-20000, and the ratio of the organic silicon modified acrylate and the polyurethane acrylate resin is 3:7-9:1, and the skin-sensing surface paint layer has a nano-level micro-crease structure. The width of the micro-crease structure is 5nm-50nm. The width of the micro-crease structure is 5nm-20nm. The cross-sectional thickness of the micro-crease structure is less than or equal to 8μm. The cross-sectional thickness of the micro-crease structure is less than or equal to 6.5μm.

2. The skin-appearing article of claim 1, wherein The dynamic friction coefficient of the skin-sensing surface paint layer is less than or equal to 0.

12.

3. The skin-appearing article of claim 2, wherein The molecular weight of the organic silicon modified acrylate is 8000-10000, and the molecular weight of the polyurethane acrylate resin is 6000-10000.

4. The skin-textured appearance piece according to any one of claims 1 to 3, wherein The thickness of the skin-sensing surface paint layer is 15μm-40μm.

5. The skin-textured appearance piece of claim 4, wherein, The intermediate paint layer comprises a primer layer.

6. The skin-textured appearance piece according to any one of claims 1-3, wherein, The intermediate paint layer further comprises a midcoat layer, which is arranged between the primer layer and the skin-sensing surface paint layer.

7. The skin-textured appearance piece according to any one of claims 1-3, wherein, Alternatively, the intermediate paint layer further comprises a color paint layer, which is arranged between the primer layer and the skin-sensing surface paint layer.

8. The skin-textured appearance piece according to any one of claims 1-3, wherein, The intermediate paint layer comprises a color paint layer.

9. The skin-textured appearance piece of any of claims 1-3, wherein, The substrate layer is a metal layer, and a micro-arc oxidation layer is further arranged between the substrate layer and the intermediate paint layer.

10. The skin-textured appearance piece of claim 9, wherein, The substrate layer is an aramid fiber layer, and a sanding paint layer is further arranged between the substrate layer and the intermediate paint layer. The skin-sensing surface paint layer comprises organic silicon modified acrylate with a molecular weight of 8000-20000 and polyurethane acrylate resin with a molecular weight of 6000-20000, and the ratio of the organic silicon modified acrylate and the polyurethane acrylate resin is 3:7-9:1, and the skin-sensing surface paint layer has a nano-level micro-crease structure.

11. The skin-textured appearance piece of any of claims 1-3, wherein, The width of the micro-crease structure is 5nm-50nm.

12. The skin-textured appearance piece of any of claims 1-3, wherein, The width of the micro-crease structure is 5nm-20nm.

13. The skin-textured appearance piece of any of claims 1-3, wherein, The cross-sectional thickness of the micro-crease structure is less than or equal to 8μm.

14. A method of making an appearance piece having a skin feel, the method comprising: The cross-sectional thickness of the micro-crease structure is less than or equal to 6.5μm. The dynamic friction coefficient of the skin-sensing surface paint layer is less than or equal to 0.

12. The molecular weight of the organic silicon modified acrylate is 8000-10000, and the molecular weight of the polyurethane acrylate resin is 6000-10000. The thickness of the skin-sensing surface paint layer is 15μm-40μm. The intermediate paint layer comprises a primer layer. The intermediate paint layer further comprises a midcoat layer, which is arranged between the primer layer and the skin-sensing surface paint layer. Alternatively, the intermediate paint layer further comprises a color paint layer, which is arranged between the primer layer and the skin-sensing surface paint layer. The intermediate paint layer comprises a color paint layer. The substrate layer is a metal layer, and a micro-arc oxidation layer is further arranged between the substrate layer and the intermediate paint layer.

15. The method of claim 14, wherein the skin-like appearance is achieved by, The substrate layer is an aramid fiber layer, and a sanding paint layer is further arranged between the substrate layer and the intermediate paint layer. The skin-sensing surface paint layer comprises organic silicon modified acrylate with a molecular weight of 8000-20000 and polyurethane acrylate resin with a molecular weight of 6000-20000, and the ratio of the organic silicon modified acrylate and the polyurethane acrylate resin is 3:7-9:1, and the skin-sensing surface paint layer has a nano-level micro-crease structure.

16. The method of claim 15, wherein the skin-like appearance is achieved by, The width of the micro-crease structure is 5nm-50nm. The width of the micro-crease structure is 5nm-20nm.

17. The method of claim 14-16, wherein the method further comprises, The cross-sectional thickness of the micro-crease structure is less than or equal to 8μm. The cross-sectional thickness of the micro-crease structure is less than or equal to 6.5μm.

18. The method of claim 17, wherein the skin-like appearance is achieved by, The dynamic friction coefficient of the skin-sensing surface paint layer is less than or equal to 0.

12. The molecular weight of the organic silicon modified acrylate is 8000-10000, and the molecular weight of the polyurethane acrylate resin is 6000-10000.

19. The method of claim 14-16, wherein the method further comprises, The thickness of the skin-sensing surface paint layer is 15μm-40μm. The skin-sensing surface paint layer comprises organic silicon modified acrylate with a molecular weight of 8000-20000 and polyurethane acrylate resin with a molecular weight of 6000-20000, and the ratio of the organic silicon modified acrylate and the polyurethane acrylate resin is 3:7-9:1, and the skin-sensing surface paint layer has a nano-level micro-crease structure.

20. An electronic device, comprising: The width of the micro-crease structure is 5nm-50nm. The width of the micro-crease structure is 5nm-20nm. The cross-sectional thickness of the micro-crease structure is less than or equal to 8μm. The cross-sectional thickness of the micro-crease structure is less than or equal to 6.5μm. The dynamic friction coefficient of the skin-sensing surface paint layer is less than or equal to 0.

12. The molecular weight of the organic silicon modified acrylate is 8000-10000, and the molecular weight of the polyurethane acrylate resin is 6000-10000. The thickness of the skin-sensing surface paint layer is 15μm-40μm. The skin-sensing surface paint layer comprises organic silicon modified acrylate with a molecular weight of 8000-20000 and polyurethane acrylate resin with a molecular weight of 6000-20000, and the ratio of the organic silicon modified acrylate and the polyurethane acrylate resin is 3:7-9:1, and the skin-sensing surface paint layer has a nano-level micro-crease structure. The width of the micro-crease structure is 5nm-50nm. The width of the micro-crease structure is 5nm-20nm. The cross-sectional thickness of the micro-crease structure is less than or equal to 8μm. The cross-sectional thickness of the micro-crease structure is less than or equal to 6.5μm. The dynamic friction coefficient of the skin-sensing surface paint layer is less than or equal to 0.

12. The molecular weight of the organic silicon modified acrylate is 8000-10000, and the molecular weight of the polyurethane acrylate resin is 6000-10000. The thickness of the skin-sensing surface paint layer is 15μm-40μm. The skin-sensing surface paint layer comprises organic silicon modified acrylate with a molecular weight of 8000-20000 and polyurethane acrylate resin with a molecular weight of 6000-20000, and the ratio of the organic silicon modified acrylate and the polyurethane acrylate resin is 3:7-9:1, and the skin-sensing surface paint layer has a nano-level micro-crease structure. The width of the micro-crease structure is 5nm-50nm. The width of the micro-crease structure is 5nm-20nm. The cross-sectional thickness of the micro-crease structure is less than or equal to 8μm. The cross-sectional thickness of the micro-crease structure is less than or equal to 6.5μm. The dynamic friction coefficient of the skin-sensing surface paint layer is less than or equal to 0.

12. The molecular weight of the organic silicon modified acrylate is 8000-10000, and the molecular weight of the polyurethane acrylate resin is 6000-10000. The thickness of the skin-sensing surface paint layer is 15μm-40μm. The skin-sensing surface paint layer comprises organic silicon modified acrylate with a molecular weight of 8000-20000 and polyurethane acrylate resin with a molecular weight of 6000-20000, and the ratio of the organic silicon modified acrylate and the polyurethane acrylate resin is 3:7-9:1, and the skin-sensing surface paint layer has a nano-level micro-crease structure. The width of the micro-crease structure is 5nm-50nm. The width of the micro-crease structure is 5nm-20nm. The cross-sectional thickness of the micro-crease structure is less than or equal to 8μm. The cross-sectional thickness of the micro-crease structure is less than or equal to 6.5μm. The dynamic friction coefficient of the skin-sensing surface paint layer is less than or equal to 0.

12. The molecular weight of the organic silicon modified acrylate is 8000-10000, and the molecular weight of the polyurethane acrylate resin is 6000-10000. The thickness of the skin-sensing surface paint layer is 15μm-40μm. The skin-sensing surface paint layer comprises organic silicon modified acrylate with a molecular weight of 8000-20000

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