Equipment housing with top coating

Abstract

An exemplary device housing includes a substrate and a top coating including a top coating formulation disposed on a surface of the substrate. The topcoat formulation comprises a polymer, a pigment, and a balance of water, the pigment comprising zirconium dioxide nanoparticles present in an amount of from about 0.3 weight percent to about 5 weight percent of the total weight of the topcoat formulation.

Description

Background of the Invention

[0002] Electronic devices such as laptop computers and mobile phones are used by many people for personal, entertainment and commercial purposes. Electronic devices include electronic components that may be covered or enclosed by a device housing. Many electronic devices are portable so that others can see them, and the aesthetic finish of the device housing is of increasing interest. For example, users may select electronic devices based on aesthetics, in addition to other technical features. The device housing may provide various functional features, including protection of internal electronic components from damage and aesthetics.

[0003] BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Figure 1 is an example of a device housing including a top coating according to an example of the present disclosure.

[0005] Figures 2A-2D is an example of a top coating formulation for a top coating according to an example of the present disclosure.

[0006] Figure 3 An exemplary electronic device including a device housing according to an example of the present disclosure is provided.

[0007] Figure 4 is an exemplary device housing including a plastic substrate and a top coating according to examples of the present disclosure.

[0008] Figure 5A-5B is an exemplary device housing including a metal substrate and a top coating according to examples of the present disclosure.

[0009] Figure 6 An exemplary method of forming a device housing including a top coating according to an example of the present disclosure.

[0010] Figure 7A-7B is an experimental example of zirconium dioxide nanoparticles according to an example of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the following detailed description, reference is made to the accompanying drawings which form a part thereof, and in which specific embodiments in which the present disclosure may be implemented are shown by way of illustration. It should be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. Therefore, the following detailed description should not be considered to have a limiting meaning, and the scope of the present disclosure is defined by the appended claims. It should be understood that, unless otherwise specifically stated, the features of the various examples described herein may be combined with each other in part or in whole.

[0013] Device housing, sometimes referred to as device cover, can cover and protect the electronic components of electronic devices such as laptop computers, tablet computers and mobile phones. For the purpose of aesthetics, the device housing can have a paint formulation layer applied thereto so that a colored appearance is provided for the device housing. The device housing can include a substrate formed by materials such as plastic or metal, wherein the paint formulation is on the outer surface of the substrate. The inner surface of the substrate can be close to and / or additionally face the electronic components of the electronic device, wherein the outer surface is relative to the inner surface and is exposed to the environment. Because the outer surface of the device housing is exposed to the environment, the paint layer may be scratched, peeled off or otherwise removed, which may expose the substrate below. The substrate can be formed by a material with a different color from the paint layer, and the substrate color and / or different colors may be aesthetically unpleasant to the user.

[0014] Examples of the present disclosure relate to a device housing, an electronic device including a device housing, and a method for forming a device housing, wherein the device housing includes a top coating that is scratch-resistant, peelable, or otherwise removed. The top coating includes a top coating formulation disposed on the surface of a substrate forming the device housing. The top coating formulation may include a polymer, a pigment including zirconium dioxide nanoparticles, and a balance of water, such as deionized water. The pigment including zirconium dioxide nanoparticles may be present in an amount of about 0.3 weight % (wt %) to about 5 weight % of the total weight of the top coating formulation. Compared with other top coatings, zirconium dioxide nanoparticles may enhance the surface hardness of the top coating on the surface of the device housing. For example, the top coating may have a pencil hardness of at least 3 or at least 4 and / or a Mohs hardness of at least 6. The enhanced surface hardness may reduce scratching and / or peeling of paint from the device housing. In addition, compared with other top coatings, the top coating and / or the top coating formulation forming the top coating may have reduced volatile organic compound (VOC) emissions, thereby providing a more environmentally friendly top coating formulation. For example, the topcoat formulation can have a VOC emission of less than about 500 grams per liter (g / L). In some examples, the topcoat formulation can have a VOC emission of about 400 g / L to about 500 g / L, or less than about 420 g / L.

[0015] As used herein, a device housing includes and / or refers to a housing or outer casing of an electronic device. A device housing may include a substrate that may be formed of a metal or non-metallic material such as plastic. The device housing may be formed by molding, casting, machining, bending, processing, stamping, and the like. The device housing may contain or cover electronic components of an electronic device and may be an integral part of the electronic device. A device housing is not meant to refer to a removable protective case that may be purchased separately from the electronic device (such as for smartphones and tablets).

[0016] Electronic devices include and / or refer to devices with electronic components. Exemplary electronic devices include portable electronic devices, such as laptop computers, tablet computers, mobile phones, game consoles, e-books or readers, and audio players, as well as non-portable electronic devices or other devices, such as desktop computers, keyboards, monitors, television screens and combinations thereof. Electronic components can be enclosed by a device housing. As used herein, encapsulation or surrounding includes and / or refers to the complete or partial encapsulation of the electronic components. For example, the device housing may include holes or openings to contact at least some electronic components, such as input / output ports (e.g., charging ports, universal serial bus ports, headphone ports), speakers and microphones, and components such as cameras. Other electronic components can be completely enclosed by the device housing, such as motherboards, batteries, sim cards, wireless transceivers, memory storage drives, etc.

[0017] In some examples, a device housing may be formed from multiple sections or substrates, and multiple sections may be assembled with electronic components to enclose the electronic device. The term "device housing" may refer to individual sections or to a common section that is assembled with electronic components to make a complete electronic device. In other examples, a device housing may be formed from one section.

[0018] Turning now to the accompanying drawings, Figure 1 1 is an example of a device housing including a top coating according to an example of the present disclosure. The device housing 100 may enclose electronic components of an electronic device and / or otherwise form a part of the electronic device.

[0019] like Figure 1 As shown, the device housing 100 includes a substrate 102 and a top coating 104. The top coating 104 is disposed on the surface of the substrate 102. As used herein, "disposed on" is not limited to being directly disposed on the surface of the substrate 102, and may include a layer between the surface of the substrate 102 and the top coating 104.

[0020] The substrate 102 may be formed of a metal material or a plastic material. The thickness of the substrate 102 may be selected to provide a certain level of strength and / or weight for the device housing 100 of the electronic device. In some examples, the substrate 102 may have a thickness of about 0.5 mm to about 2 centimeters (cm), about 1 millimeter (mm) to about 1.5 cm, about 1.5 mm to about 1.5 cm, about 2 mm to about 1 cm, about 3 mm to about 1 cm, about 4 mm to about 1 cm, or about 1 mm to about 5 mm. The substrate 102 may be formed to fit any type of electronic device and may have any thickness suitable for any type of electronic device.

[0021] Exemplary metal materials forming the substrate 102 include aluminum, aluminum alloys, magnesium, magnesium alloys, lithium, lithium alloys, titanium, titanium alloys, stainless steel, composite metals, and various combinations thereof. Other exemplary metal materials include niobium, zinc, bismuth, copper, cadmium, iron, thorium, strontium, zirconium, manganese, nickel, lead, silver, chromium, silicon, tin, gadolinium, yttrium, calcium, antimony, cerium, lanthanum, and the like, and various combinations thereof. Exemplary plastic materials forming the substrate 102 include polycarbonate (PC), acrylonitrile butadiene styrene (ABS), PC and ABS, polyphenylene sulfide (PPS), high impact polystyrene (HIPS), and the like, and various combinations thereof.

[0022] The topcoat layer 104 includes (e.g., is formed from) a topcoat formulation 106 disposed on a surface of the substrate 102. Figure 3 As further described and illustrated, the substrate 102 may include an inner surface facing electronic components of the electronic device and an outer surface opposite the inner surface. The surface of the substrate 102 on which the topcoat formulation 106 is disposed may include an outer surface that is exposed to the environment and visible to a user.

[0023] like Figure 1 As shown, the top coating formulation 106 includes a polymer 108, a pigment 110, and a balance of water 112. The top coating 104 can be applied over the primer layer on the outer surface of the substrate 102, which includes the pigment and imparts visual color to the device housing 100. The top coating 104 can provide protection for the primer layer, such as preventing or reducing scratching or peeling of the primer layer.

[0024] Exemplary polymers in the topcoat formulation 106 include polyesters, acrylics, epoxies, polyurethanes, alkyd resins, and polyurethane copolymers, and combinations thereof. In some examples, the topcoat formulation 106 may include a polymer 108 present in an amount of about 25 wt % to about 40 wt % of the total weight of the topcoat formulation 106. In some examples, the polymer 108 is present in an amount of about 30 wt % to about 40 wt %, about 35 wt % to about 40 wt %, about 25 wt % to about 35 wt %, about 25 wt % to about 30 wt %, about 25 wt %, about 30 wt %, about 35 wt % or about 40 wt %, etc., of the total weight of the topcoat formulation 106.

[0025] The pigment 110 includes zirconium dioxide nanoparticles present in an amount of about 0.3 wt % to about 5 wt % of the total weight of the topcoat formulation 106. The zirconium dioxide nanoparticles include and / or refer to particles formed of zirconium (Zr) and two oxide (e.g., OH) compounds. In some examples, the zirconium dioxide nanoparticles are present in an amount of about 0.5 wt % to about 5 wt %, about 1 wt % to about 5 wt %, about 1.5 wt % to about 5 wt %, about 2 wt % to about 5 wt %, about 2.5 wt % to about 5 wt %, about 3 wt % to about 5 wt %, about 3.5 wt % to about 5 wt %, about 4 wt % to about 5 wt %, about 4.5 wt % to about 5 wt %, about 0.3 wt % to about 4.5 wt %, about 0.3 wt % to about 4 wt %, about 0.3 wt % to about 3.5 wt % The invention also provides an amount of about 0.3 wt % to about 3 wt %, about 0.3 wt % to about 2.5 wt %, about 0.3 wt % to about 2 wt %, about 0.3 wt % to about 1.5 wt %, about 0.3 wt % to about 1 wt %, about 1 wt % to about 2 wt %, about 1 wt % to about 3 wt %, about 1 wt % to about 4 wt %, about 1.5 wt % to about 3 wt %, about 1.5 wt % to about 4 wt %, about 2 wt % to about 4 wt %, about 2 wt % to about 3 wt %, or about 2 wt % to about 4 wt %.

[0026] The zirconium dioxide nanoparticles in the top coating formulation 106 can provide hardness to the top coating 104. For example, the top coating 104 has a pencil hardness (H) of at least 3 or at least 4 or greater, such as up to about 6. In some examples, the top coating 104 can have a Mohs hardness of at least 6. In some examples, the top coating 104 has a Mohs hardness of about 5 to at least 10, at least 6, at least 7, at least 8, at least 9, at least 10 or greater. In addition, the top coating formulation 106 can be environmentally friendly. For example, the top coating formulation 106 can be associated with VOC emissions of less than about 500g / L, such as about 400g / L to about 500g / L or less than about 420g / L.

[0027] The top coating formulation 106 may include Figure 1 Variations shown, such as those containing additional components. Exemplary variations include surface modifiers, surfactants, and solvents. Figure 2A-2B 1 shows an exemplary variation of a topcoat formulation 106. In some examples, the device housing 100 may include a Figure 1 Variations are shown, such as additional layers on the device housing 100. Figure 4 A-5 shows various examples of device housings.

[0028] Figures 2A-2D is an example of a top coating formulation for a top coating according to an example of the present disclosure.

[0029] Figure 2A The top coating formulation 206 may include Figure 1 The exemplary embodiment of the top coating formulation 106 shown and / or includes at least some Figure 1 The top coating formulation 106 shown has substantially the same features, and for ease of reference, common features are not repeated in full, but may include examples previously described. For example, similar to Figure 1 , Figure 2A The topcoat formulation 206 includes a polymer 208 , a pigment 210 including zirconium dioxide nanoparticles 211 , and water 212 .

[0030] The zirconium dioxide nanoparticles 211 may include or be powder particles having a diameter of about 5 nanometers (nm) to about 100 nm. In some examples, the zirconium dioxide nanoparticles 211 may include or be powder particles having a diameter of about 20 nm to about 50 nm. For example, the pigment 210 may be composed of zirconium dioxide nanoparticles 211 of similar size or different sizes within a diameter range. As used herein, size refers to the diameter of a spherical particle or the average diameter of a non-spherical particle. In some examples, the zirconium dioxide nanoparticles 211 may be tetrahedral in shape. In some examples, the zirconium dioxide nanoparticles 211 may be round. In some examples, analytical chemical analysis may be used to measure the diameter or average diameter of the zirconium dioxide nanoparticles 211. For example, the average diameter of the zirconium dioxide nanoparticles 211 may be measured using a volume-based size distribution. The size of the zirconium dioxide nanoparticles 211 may be measured by using a static light scattering technique such as laser diffraction. In some examples, the zirconium dioxide nanoparticles 211 may be refractive and have a Mohs hardness of at least 6.

[0031] In some instances, such as Figure 2B As shown, the pigment 210 further includes a surface modifier 213 combined with the zirconium dioxide nanoparticles 211. That is, the zirconium dioxide nanoparticles 211 can be surface-modified. Exemplary surface modifiers 213 include vinyl trimethoxy silane, 10-methacryloxy-decyl-dihydrogen-phosphate (10-MDP), 3-methacryloxypropyl trimethoxy silane, vinyl triisopropoxy silane, methyl triethoxy silane (MTES) and tetraethoxy silane (TEOS), methyl trichloro silane, methyl trimethoxy silane and methyl triethoxy silane. In some examples, the surface modifier 213 includes vinyl trimethoxy silane (such as Figure 2C ) or 10-MDP (as Figure 2D). The surface modifier 213 may be bonded to the zirconium dioxide nanoparticles 211 via hydrogen bonding and / or chemical bonding.

[0032] Modifying the zirconium dioxide nanoparticles 211 with a surface modifier 213 can improve the sprayability or flowability of the top coating formulation compared to unmodified zirconium dioxide nanoparticles 211. For example, unmodified zirconium dioxide nanoparticles 211 may settle at a high density, or may agglomerate together without spreading. The surface modifier 213 can improve the distribution and dispersion of the zirconium dioxide nanoparticles 211 in the top coating, as well as reduce or avoid sedimentation or agglomeration.

[0033] Return to reference Figure 2A In some examples, the top coating formulation 206 may include additional components, such as a surfactant 214 and / or a solvent 216. The surfactant 214 may improve the sprayability of the top coating formulation 206 and / or allow the top coating formulation 206 to be evenly dispersed into the top coating when applied. For example, the solvent 216 may be used to dissolve the components and / or disperse the zirconium dioxide nanoparticles 211 into the solution.

[0034] Exemplary surfactants include alcohol sulfates, alkylbenzene sulfonates, sodium caseinate, sodium polyacrylate, sodium polyoxyethylene alkyl ether carboxylates, and sodium lauryl sulfate, and combinations thereof. The surfactant 214 may be present in an amount of about 0.3 wt % to about 2 wt % of the total weight of the top coating formulation 206. In some examples, the surfactant 214 is present in an amount of about 0.5 wt % to about 2 wt %, about 1 wt % to about 2 wt %, about 1.5 wt % to about 2 wt %, about 0.3 wt % to about 1.5 wt %, about 0.3 wt % to about 1 wt %, about 0.3 wt % to about 0.5 wt %, about 0.5 wt % to about 1.5 wt %, or about 1 wt % to about 1.5 wt %, etc., of the total weight of the top coating formulation 206.

[0035] Exemplary solvents include methyl ethyl ketone, methyl isobutyl ketone, 3-methoxy-3-methyl-1-butyl acetate, ethyl acetate, and butyl acetate. The solvent 216 can be present in an amount of about 15 wt % to about 25 wt % of the total weight of the top coating formulation 206. In some examples, the solvent 216 is present in an amount of about 15 wt % to about 20 wt %, about 18 wt % to about 20 wt %, about 20 wt % to about 25 wt %, about 22 wt % to about 25 wt %, about 15 wt %, about 20 wt %, or about 25 wt %, etc., of the total weight of the top coating formulation 206.

[0036] In some examples, the top coating formulation 206 includes: (i) about 25 wt % to about 40 wt % of polymer 208; (ii) about 0.3 wt % to about 5 wt % of pigment 210 containing zirconium dioxide nanoparticles 211; (iii) about 0.3 wt % to about 2 wt % of surfactant 214; (iv) about 15 wt % to about 25 wt % of solvent 216; and (v) the balance of water 212 (e.g., deionized water). The weight % provided above includes the amount of the total weight of the top coating formulation 206.

[0037] Figure 2C-2D Exemplary surface-modified zirconium dioxide nanoparticles 219-1, 219-2, 219-3, 219-4 are shown. More specifically, Figure 2C Surface-modified zirconium dioxide nanoparticles 219 - 1 are shown, which are formed by surface-modifying or reacting zirconium dioxide nanoparticles 211 with a surface modifier 213 - 1 including vinyltrimethoxysilane. Figure 2D Surface-modified zirconium dioxide nanoparticles 219 - 2 , 219 - 3 , 219 - 4 formed by surface-modifying or reacting zirconium dioxide nanoparticles 211 with surface modifiers 213 - 2 , 213 - 3 , 213 - 4 , 213 - 5 containing 10-MDP are shown.

[0038] Figure 3 An exemplary electronic device including a device housing according to an example of the present disclosure is provided. Figure 3 The device housing 300 and the top coating formulation 306 may include Figure 1 and Figure 2A-2B The exemplary embodiments of the device housing 100 and top coating formulations 106, 206 shown and / or including at least some Figure 1 and Figure 2A-2B The device housing 100 and topcoat formulations 106, 206 are shown to have substantially identical features, and for ease of reference, common features are not repeated in full, but may include examples previously described.

[0039] The electronic device 320 includes an electronic component 322 and a device housing 300 that accommodates the electronic component 322. Figure 3 A single electronic component 322 is shown, and the electronic device 320 may include a group of electronic components enclosed by the device housing 100.

[0040] The device housing 300 includes a base 302, which includes an inner surface 326 facing an electronic component 322 and an outer surface 324 opposite the inner surface 326. As previously described, the outer surface 324 may be visible to the user and may be exposed to the environment. In contrast, the inner surface 326 may not be visible to the user and / or may not be easily visible.

[0041] Similar to Figure 1 , the device housing 300 further includes a top coating 304, the top coating 304 including a top coating formulation 306 disposed on the outer surface 324 of the substrate 302. The top coating formulation 306 includes a polymer 308, a pigment 310 including zirconium dioxide nanoparticles, and water 312. As previously described, the pigment 310 may be present in an amount of about 0.3 wt % to about 5 wt % of the total weight of the top coating formulation 306. Figure 2A As shown, topcoat formulation 306 may include additional components, such as surfactants and / or solvents.

[0042] The device housing 300 and / or the top coating formulation 306 may include variations such as Figure 2A-2B and / or Figure 4-5B In some examples, such as Figure 2A As shown, the top coating formulation 306 may include additional components, such as surfactants and / or solvents. In some examples, the zirconium dioxide nanoparticles of the pigment 310 are surface modified to improve distribution and dispersion and to avoid sedimentation of the zirconium dioxide nanoparticles in the top coating 304 (e.g., to reduce agglomeration), such as by Figure 2B Surface modifiers as shown.

[0043] In some examples, the device housing 300 includes an additional layer. For example, the device housing 300 may further include a primer layer between the outer surface 324 of the substrate 302 and the top coating 304. The primer layer may include or be formed by a primer formulation, and the primer formulation includes a second polymer and a second pigment. The second polymer may include epoxy resin, epoxy-polyester, polyester, polyurethane or polyurethane copolymer and a combination thereof. In some examples, the second polymer may be present in an amount of about 20% by weight to about 45% by weight of the total weight of the primer formulation. The second pigment may provide a colored appearance for the device housing 300. Exemplary pigments include talc, carbon black, titanium dioxide, clay, mica, barium sulfate, calcium carbonate or another color pigment and a combination thereof. In some examples, the pigment may be present in an amount of about 2% by weight to about 15% by weight of the total weight of the primer formulation. The primer formulation may include other components, such as surfactants, solvents and additives, such as buffers and / or biocides. The remainder of the primer formulation may include water.

[0044] In some examples, substrate 302 can be formed of a plastic material, and device housing 300 can further include a primer layer between outer surface 324 of substrate 302 and top coating 304 , the primer layer including a primer formulation including a second polymer and a second pigment.

[0045] In other examples, substrate 302 can be formed of a metal material. In such examples, device housing 300 can further include a treatment layer disposed on an outer surface 324 (e.g., between outer surface 324 and a primer layer) and an inner surface 326 of the metal substrate. As further described herein, the treatment layer can include a passivation layer or an oxide layer. The passivation layer or oxide layer can be disposed on the outer surface 324 of the substrate, or on both the outer surface 324 and the inner surface 326 of the substrate. The treatment layer can help provide resistance to corrosion and wear against the metal substrate. The treatment layer can further help provide electrical insulation and durability to the metal substrate.

[0046] Figure 4 is an exemplary device housing including a plastic substrate and a top coating according to an example of the present disclosure. As previously described, Figure 4 The device housing 400 shown includes a plastic substrate 402, a top coating layer 404, and a primer layer 430 disposed between an outer surface 424 of the plastic substrate 402 and the top coating layer 404. For ease of reference, the details thereof will not be repeated.

[0047] Primer layer 430 can be formed by applying primer formulation to the outer surface 424 of plastic substrate 402. Primer formulation can include a second polymer and a second pigment. As previously mentioned, the second polymer can include epoxy resin, epoxy-polyester, polyester, polyurethane or polyurethane copolymer and a combination thereof, and it exists in an amount of about 20% by weight to about 45% by weight of the gross weight of the primer formulation. The second pigment can include talcum, carbon black, titanium dioxide, clay, mica, barium sulfate, calcium carbonate or another color pigment and a combination thereof, and it exists in an amount of about 2% by weight to about 15% by weight of the gross weight of the primer formulation. In some instances, the primer formulation applied can be cured by baking the surface 424 at a temperature of about 80 degrees Celsius (℃) to about 140℃ for about 15 minutes to about 40 minutes.

[0048] The top coating 404 can be formed by applying a top coating formulation to the primer layer 430. The top coating formulation can include any of the aforementioned formulations. In some examples, the applied top coating formulation can be cured by baking the surface 424 at a temperature of about 80° C. to about 140° C. for about 15 minutes to about 40 minutes.

[0049] In some examples, the thickness of the primer layer 430 is about 10 μm to about 18 μm, and the thickness of the top coating layer 404 is about 6 μm to about 15 μm. However, examples are not limited thereto, and different layers may have various thicknesses. The thickness of various layers such as the primer layer, the top coating layer, and / or the treatment layer may be measured after forming the layers, for example, using a screw micrometer or a scanning electron microscope (SEM).

[0050] Figure 5A-5B is an exemplary device housing including a metal substrate and a top coating according to an example of the present disclosure. As previously described, Figure 5A-5B Each of the illustrated device housings 500, 501 includes a metal substrate 502, a top coating 504, and a primer layer 530 disposed between an outer surface 524 of the metal substrate 502 and the top coating 504. Details thereof will not be repeated.

[0051] In some examples, the metal material used for the metal substrate 502 can be a light metal. The term "light metal" includes and / or refers to metals and alloys having a relatively low density, including a density of less than about 5 g / cm 3 In some examples, the light metal may be a material including aluminum, magnesium, titanium, lithium, zinc, alloys thereof, and / or combinations thereof. These light metals may have useful properties, such as low weight, high strength, and an attractive appearance. Metallic materials such as aluminum or magnesium may have porous surfaces susceptible to chemical reactions or corrosion at the surface. As further described herein, the metal substrate may be treated to form a treatment layer, such as a passivation layer or an oxide layer, on the outer and inner surfaces of the substrate.

[0052] Figure 5A An exemplary device housing 500 is shown including a metal substrate 502 and first and second passivation layers 532-1, 532-2. For example, the first passivation layer 532-1 is disposed on an outer surface 524 of the metal substrate 502, and the second passivation layer 532-2 is disposed on an inner surface 526 of the metal substrate 502. A primer layer 530 is disposed between the first passivation layer 532-1 and the top coating layer 504.

[0053] The first and second passivation layers 532-1, 532-2 may include or be formed of a passivation agent, the passivation agent including a passivation agent selected from molybdates, vanadates, phosphates, chromates, stannates, and manganese salts. The passivation agent includes and / or refers to a chemical that reacts with the surface of the substrate to turn at least a portion of the substrate into a non-metal. In order to form the passivation layers 532-1, 532-2, the inner surface 524 and the outer surface 526 of the metal substrate 502 may be chemically treated with or using a passivation agent so that the surfaces 524, 526 react with the passivation agent and become non-metallic surfaces, such as salt films. In some examples, the metal substrate 502 may be chemically treated for a time of about 0.5 minutes to about 3 minutes at a temperature range of about 25°C to about 40°C to obtain the passivation layers 532-1, 532-2. In some examples, the passivation agent may include a passivation agent present in an amount of about 3% by weight to about 15% by weight of the total weight of the passivation agent, and the remainder of water.

[0054] In some examples, the primer layer 530 has a thickness of about 10 μm to about 18 μm, the top coating layer 504 has a thickness of about 6 μm to about 15 μm, and the first and second passivation layers 532-1, 532-2 have a thickness of about 1 μm to about 5 μm. However, examples are not limited thereto, and different layers may have various thicknesses.

[0055] The passivation layer may include and / or refer to a layer or coating on the metal substrate 502. Passivation may refer to the use of a coating of a protective material such as a metal oxide to create a shell that resists corrosion. A passivating agent (e.g., a chemical) may be applied to the surface of the metal substrate 502 to induce the passivation layers 532-1, 532-2. The passivation layers 532-1, 532-2 may be transparent. It should be noted that, for convenience, the passivation layer is described as a layer and may be in the form of a layer. However, the term "passivation layer" also includes the metal surface treatment of the exposed metal substrate 502.

[0056] In some examples, the passivation layer 532-1, 532-2 may include a chelating agent and a metal ion or a chelated metal complex thereof, wherein the metal ion is an aluminum ion, an indium ion, a nickel ion, a chromium ion, a tin ion or a zinc ion. In some examples, a passivation treatment may be applied at a pH of about 2 to about 6. In some examples, the pH may be about 2.5 to about 3.5. In a further example, the passivation layer 532-1, 532-2 may include an oxide of one of these metals. In some examples, various pollutants may be present on the surface of the metal substrate 502. Chelating agents may be used to chelate such pollutants and prevent pollutants from being attached to the surface of the metal substrate 502. Non-limiting examples of chelating agents may include ethylenediaminetetraacetic acid, ethylenediamine, nitrilotriacetic acid, diethylenetriaminepenta(methylenephosphonic acid), nitrilotri(methylenephosphonic acid) and 1-hydroxyethane-1,1-diphosphonic acid. Meanwhile, a passivation layer may be formed on the surface of the metal substrate 502. In some examples, the passivation layers 532-1, 532-2 may be added to a pre-existing surface of the metal substrate 502 such that the passivation layers 532-1, 532-2 include additional material added to the surface of the metal substrate 502. In other examples, the passivation layers 532-1, 532-2 may involve converting an existing surface of the metal substrate 502 into the passivation layer such that no net addition of material to the pre-existing surface occurs.

[0057] The passivation layers 532-1, 532-2 can be applied via any of the above-mentioned passivation treatments, which can be applied for a period of about 0.5 minutes to about 3 minutes. The primer layer 530 can be formed by applying a primer formulation to the first passivation layer 532-1. The primer formulation can include any of the aforementioned formulations. The applied primer formulation can be cured by baking the surface at a temperature of about 80°C to about 140°C for about 15 minutes to about 40 minutes. And, the top coating 504 can be formed by applying a top coating formulation to the primer layer 530. The top coating formulation can include any of the aforementioned formulations. The applied top coating formulation can be cured by baking the surface at a temperature of about 80°C to about 140°C for about 15 minutes to about 40 minutes.

[0058] Figure 5B An exemplary device housing 501 including a metal substrate 502 and first and second oxide layers 534-1, 534-2 is shown. For example, the first oxide layer 534-1 is disposed on the outer surface 524 of the metal substrate 502, and the second oxide layer 534-2 is disposed on the inner surface 526 of the metal substrate 502, wherein the first oxide layer 534-1 and the second oxide layer 534-2 include oxide films. A primer layer 530 is disposed between the first oxide layer 534-1 and the top coating layer 504.

[0059] In some examples, the primer layer 530 has a thickness of about 10 μm to about 18 μm, the top coating layer 504 has a thickness of about 6 μm to about 15 μm, and the first and second oxide layers 534-1, 534-2 have a thickness of about 2 μm to about 7 μm. However, examples are not limited thereto, and different layers may have various thicknesses.

[0060] The oxide layer 534-1, 534-2 may be applied to the metal substrate 502 via a micro-arc oxidation (MAO) treatment. MAO, also known as plasma electrolytic oxidation, is an electrochemical process in which a micro-discharge of compounds on the surface of the metal substrate 502 is used to oxidize the surface of the metal substrate 502 when immersed in a chemical or electrolytic bath in an electrolytic solution (e.g., such as an alkaline electrolyte). The electrolytic solution may primarily contain water and about 1 wt % to about 5 wt % of an oxidant, such as an alkali metal silicate, an alkali metal hydroxide, an alkali metal fluoride, an alkali metal phosphate, an alkali metal aluminate, or the like, or a combination thereof. The oxidant includes and / or refers to an electrolytic compound that can decompose into cations and ions when dissolved. Exemplary electrolyte solutions include alkaline solutions having an electrolyte selected from sodium silicate, sodium phosphate, potassium fluoride, potassium hydroxide, sodium hydroxide, fluorozirconate, sodium hexametaphosphate, sodium fluoride, aluminum oxide, silicon dioxide, ferric ammonium oxalate, phosphates, polyethylene oxide alkylphenol ethers, and combinations thereof. The oxidizing agent may be included in an amount of about 1.5 wt % to about 3.5 wt %, or about 2 wt % to about 3 wt % based on the total weight of the electrolyte solution, although examples are not limited thereto.

[0061] In some examples, the electrolyte solution can be maintained inside the electrolytic bath and maintained at a temperature of about 10°C to about 45°C. In some examples, the electrolyte solution can be maintained inside the electrolytic bath and maintained at a temperature of about 15°C to about 40°C, about 20°C to about 40°C, or about 25°C to about 35°C. The surfaces 524, 526 of the metal substrate 502 are then immersed in the electrolyte solution inside the electrolytic bath. In some examples, an electric current or voltage can be applied to the metal substrate 502 to generate plasma on the surface of the metal substrate 502. In this process, the metal substrate 502 can act as an electrode immersed in the electrolyte solution, and the counter electrode can be any other electrode that is also in contact with the electrolyte. In some examples, the counter electrode can be an inert metal, such as stainless steel. In some examples, the bath containing the electrolyte solution is conductive, and the bath itself can be used as a counter electrode.

[0062] In some examples, a high direct current or alternating voltage can be applied to the metal substrate 502 and the counter electrode. In some examples, the voltage can be about 200 volts (V) or higher, such as about 200V to about 600V, about 250V to about 600V, about 250V to about 500V, or about 200V to about 300V, and the bath is in the above temperature range at the same time. The process can oxidize the surface 524, 526 to form an oxide layer from the substrate material. Various metal or metal alloy substrates can be used, including, for example, aluminum, titanium, lithium, magnesium and / or alloys thereof. Oxidation can extend below the surface 524, 526 to form an oxide layer 534-1, 534-2.

[0063] The thickness of the oxide layers 534-1, 534-2 may depend on the time for which the electrolysis is performed. In some examples, the oxide layers 534-1, 534-2 may have a thickness of about 2 μm to about 7 μm. The oxide layers 534-1, 534-2 may enhance the mechanical, wear, thermal, dielectric and / or corrosion properties of the metal substrate 502. The electrolyte solution may include various electrolytes, such as potassium hydroxide solution.

[0064] The oxide layers 534-1, 534-2 can be formed via any of the above-mentioned MAO treatments. The primer layer 530 can be formed by applying a primer formulation to the first oxide layer 534-1. The primer formulation can include any of the aforementioned formulations. The applied primer formulation can be cured by baking the surface at a temperature of about 80°C to about 140°C for a time of about 15 minutes to about 40 minutes. And, the top coating 504 can be formed by applying a top coating formulation to the primer layer 530. The top coating formulation can include any of the aforementioned formulations. The applied top coating formulation can be cured by baking the surface at a temperature of about 80°C to about 140°C for a time of about 15 minutes to about 40 minutes.

[0065] Figure 6 is an exemplary method of forming a device housing including a top coating according to an example of the present disclosure. The method 650 can be implemented to form any of the previously described device housings and / or top coatings.

[0066] At 652, method 650 includes applying a primer formulation on the outer surface of the substrate of the device housing. At 654, the method includes curing the primer formulation via applying heat to form a primer layer. At 656, method 650 includes applying a topcoat formulation to the primer layer, the topcoat formulation comprising a polymer, a pigment comprising zirconium dioxide nanoparticles, and a balance of water, the pigment being present in an amount of about 0.3 wt % to about 5 wt % of the total weight of the topcoat formulation. And, at 658, method 650 includes curing the topcoat formulation via applying heat to form a topcoat on the primer layer. For example, curing the primer formulation and the topcoat formulation may each include applying heat (to the substrate) at a temperature of about 80°C to about 140°C for a time of about 15 minutes to about 40 minutes.

[0067] Top coating formulation and / or primer formulation can be a paint composition, which can print, spray and / or be sprayed on the device housing. In some instances, the top coating formulation is applied to the primer layer to include a digital printing top coating formulation. In some instances, further digital printing primer formulation. In some instances, a layer can be formed by spraying the formulation or electrostatically applying the formulation to the surface of the substrate. Primer layer and top coating can provide aesthetic appeal and / or protection to the shell.

[0068] In various examples, method 650 further includes treating an outer surface of the device housing and an inner surface opposite the outer surface with a passivating agent or an oxidizing agent to form a treated layer prior to applying the primer formulation. For example, method 650 may include treating the outer surface and the inner surface with a passivating agent or an oxidizing agent to form a first passivating or oxidizing layer disposed on the outer surface of the substrate, such that the first passivating or oxidizing layer is disposed between the primer layer and the outer surface of the substrate, and / or a second passivating or oxidizing layer is disposed on the inner surface of the substrate.

[0069] In some instances, the device housing described herein can be manufactured by first forming a substrate. This can be achieved using various processes, including molding, insert molding, forging, casting, machining, stamping, bending, working, etc. The substrate can be made of various metals, plastics and / or other materials. In one example, a sheet or forged metal insert is molded into the shape of an outer cover. The metal used for the substrate can be aluminum, magnesium, lithium, titanium and alloys thereof. As described above, in some instances, the substrate can be a single workpiece, and in other instances, the substrate can include multiple workpieces, each of which constitutes a part of the outer cover. In addition, in some instances, the substrate can be a composite material composed of a combination of multiple metals and / or plastics, such as a layer with multiple different metals, plastics and / or other materials, or a panel or other parts of the substrate are different materials.

[0070] Various examples can relate to methods of forming a topcoat formulation. The method can include mixing a pigment comprising zirconium dioxide nanoparticles with a polymer, a solvent, a surfactant, and water. The mixing can be provided by various sources, such as a mixer. Exemplary mixers include industrial paddle mixers, high shear mixers, resonant acoustic mixers, and jet mills, etc. In some instances, a mixing grinder, such as a ball mill or a pulverizer, can be used.

[0071] Above-mentioned top coating preparation is used to form top coating on metal or plastic equipment housing, so that obtain at least 3H or 4H pencil hardness via using zirconium dioxide nanoparticles, and it can be in powder form.Zirconium dioxide nanoparticles can be used for mitigating or reducing the scratching and / or peeling of primer layer by providing enhanced surface wear resistance and hardness.The shape of zirconium dioxide nanoparticles can be tetrahedron and / or circular, and can set up chemical bonding with resin and show stable dispersion in top coating preparation.Top coating preparation and / or primer preparation can be paint composition, and it can print, spray and / or be sprayed on the equipment housing.

[0072] The various ranges provided herein include the range and any value or sub-range within the range. In addition, when "about" is used to describe a value, this includes, refers to and / or encompasses a variation (up to + / - 10%) from the value. As used herein, wt % includes or refers to the weight of a component as a percentage of the total weight of a composition or solution.

[0073] As used herein, "pigment" generally includes pigment colorants, magnetic particles, aluminum oxide, silicon dioxide and / or other ceramics, organic metals or other opaque particles, whether or not such particles impart color. Thus, although this specification primarily exemplifies the use of color pigments, the term "pigment" can be used more generally to describe color pigments and other pigments, such as organic metals, ferrites, ceramics, etc. However, in a specific example, the pigment is a color pigment or a colorant.

[0074] References throughout this specification to "an example," "an example," "some examples," etc., mean that specific elements (e.g., features, structures, and / or characteristics) described in conjunction with the example are included in the example described herein and may or may not be present in other examples. Furthermore, it is to be understood that the elements of any example may be combined in any suitable manner in the various examples unless the context clearly dictates otherwise.

[0075] When describing and claiming the examples disclosed herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0076] Although specific examples have been shown and described herein, various alternative and / or equivalent embodiments may be used to replace the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any modifications or variations of the specific examples discussed herein. Therefore, the present disclosure is intended to be limited only by the claims and their equivalents. Example

[0077] Exemplary top coating formulations containing zirconium dioxide nanoparticles, and related aspects described herein, are shown below. These examples should not be considered to limit the present disclosure, but are merely examples of how to make top coating formulations. Various experiments were involved in generating top coating formulations.

[0078] Figure 7A-7B is an experimental example of zirconium dioxide nanoparticles according to an example of the present disclosure. More particularly, the image is an image of a top coating layer comprising zirconium dioxide nanoparticles. The shape of the zirconium dioxide nanoparticles is tetrahedral, such as Fig. 7A As shown, or the shape is circular, such as Figure 7B In addition, the diameter of the zirconium dioxide nanoparticles is about 5 nm to 100 nm, and a Mohs hardness of at least 6 is achieved.

Claims

1. A device housing, comprising: substrate; and A topcoat layer comprising a topcoat formulation disposed on a surface of the substrate, the topcoat formulation comprising: polymer; a pigment comprising zirconium dioxide nanoparticles present in an amount from about 0.3 weight percent (wt %) to about 5 wt % of the total weight of the topcoat formulation; and The remaining amount of water.

2. The device housing of claim 1, wherein the polymer is present in an amount of about 25 wt % to about 40 wt % of the total weight of the top coat formulation, and the top coat has a pencil hardness (H) of at least 3.

3. The device housing of claim 1, wherein the zirconium dioxide nanoparticles are powder particles having a diameter of about 5 to about 100 nanometers (nm).

4. The device enclosure of claim 1, wherein the topcoat formulation is associated with volatile organic compound (VOC) emissions of less than about 500 grams per liter.

5. The device housing of claim 1, wherein the pigment further comprises a surface modifier bonded to the zirconium dioxide nanoparticles.

6. The device housing of claim 5, wherein the surface modifier comprises vinyltrimethoxysilane or 10-methacryloyloxy-decyl-dihydrogen-phosphate (10-MDP).

7. The device housing of claim 5, wherein the surface modifier is selected from: Vinyltrimethoxysilane, 10-methacryloxy-decyl-dihydrogen-phosphate (10-MDP), 3-methacryloxypropyltrimethoxysilane, vinyltriisopropoxysilane, methyltriethoxysilane (MTES) and tetraethoxysilane (TEOS), methyltrichlorosilane, methyltrimethoxysilane and methyltriethoxysilane.

8. An electronic device comprising: Electronic components; and A device housing, which houses the electronic components, the device housing comprising: a substrate comprising an inner surface facing the electronic component and an outer surface opposite to the inner surface; A topcoat layer comprising a topcoat formulation disposed on an outer surface of the substrate, the topcoat formulation comprising: polymers; and a pigment comprising zirconium dioxide nanoparticles, the pigment being present in an amount of about 0.3 weight percent (wt %) to about 5 wt % of the total weight of the topcoat formulation; and The remaining amount of water.

9. The device of claim 8, wherein the zirconium dioxide nanoparticles are surface modified to improve the distribution and dispersion of the zirconium dioxide nanoparticles in the top coating.

10. The device of claim 8, wherein the substrate comprises a plastic material, and the device housing further comprises: A primer layer is between the outer surface of the substrate and the topcoat layer, the primer layer comprising a primer formulation comprising a second polymer and a second pigment.

11. The device of claim 8, wherein the substrate comprises a metallic material, and the device housing further comprises: a first passivation layer disposed on an outer surface of the substrate; A second passivation layer disposed on the inner surface of the substrate, wherein the first and second passivation layers include a passivation formulation comprising a passivating agent selected from: molybdates, vanadates, phosphates, chromates, stannates, and manganese salts; and A primer layer is disposed between the first passivation layer and the top coating layer.

12. The device of claim 8, wherein the substrate comprises a metallic material, and the device housing further comprises: a first oxide layer disposed on an outer surface of the substrate; a second oxide layer disposed on an inner surface of the substrate, wherein the first and second oxide layers include oxide films; and A primer layer is disposed between the first oxide layer and the top coating layer.

13. A method comprising: applying a primer formulation to an exterior surface of a substrate of a device housing; curing the primer formulation via application of heat to form a primer layer; Applying a topcoat formulation onto the primer layer, the topcoat formulation comprising: polymer; a pigment comprising zirconium dioxide nanoparticles, the pigment being present in an amount of about 0.3 weight percent (wt %) to about 5 wt % of the total weight of the topcoat formulation; and The balance of water; and The topcoat formulation is cured via application of heat to form a topcoat layer on the primer layer.

14. The method of claim 13, wherein curing the primer formulation and the topcoat formulation each comprises applying heat at a temperature of about 80 degrees Celsius to about 140 degrees Celsius for a time of about 15 minutes to about 40 minutes.

15. The method of claim 13, further comprising treating an outer surface of the device housing and an inner surface opposite the outer surface with a passivating agent or an oxidizing agent prior to applying the primer formulation to form: a first passivation or oxide layer disposed on the outer surface of the substrate such that the first passivation or oxide layer is disposed between the primer layer and the outer surface of the substrate; and A second passivation or oxide layer is disposed on the inner surface of the substrate.

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