WO2023279792A1

WO2023279792A1 - Housing and preparation method therefor, and electronic device

Info

Publication number: WO2023279792A1
Application number: PCT/CN2022/086131
Authority: WO
Inventors: 陈奕君; 胡梦; 李聪
Original assignee: Oppo广东移动通信有限公司
Priority date: 2021-07-07
Filing date: 2022-04-11
Publication date: 2023-01-12
Also published as: CN113507806A

Abstract

The present application provides a housing, the housing comprising a polymer ceramic layer, the polymer ceramic layer comprising ceramic particles and a polymer, the surface of the ceramic particles having a recessed structure, and the polymer filling the recessed structure. The surface of the ceramic particles in the housing has a recessed structure, and the polymer fills the recessed structure, which helps to increase the contact area between the ceramic particles and the polymer, improving the interface adhesion performance of the ceramic particles and the polymer, thereby helping to improve the mechanical properties of the housing, and the housing has a ceramic texture, which better facilitates the application of the housing. The present application further provides a preparation method for a housing, and an electronic device.

Description

Shell and its preparation method and electronic equipment

technical field

The application belongs to the technical field of electronic products, and in particular relates to a casing, a preparation method thereof, and electronic equipment.

Background technique

With the improvement of consumption level, consumers not only pursue the diversification of functions of electronic products, but also have higher and higher requirements for their appearance and texture. In recent years, ceramic materials have become a hot spot in the research of electronic equipment casings due to their warm and moist texture. However, the current ceramic shell and its preparation method still need to be improved.

Contents of the invention

In view of this, the present application provides a casing, a preparation method thereof, and an electronic device.

In a first aspect, the present application provides a casing, the casing includes a polymer ceramic layer, the polymer ceramic layer includes ceramic particles and a polymer, the surface of the ceramic particles has a concave structure, and the polymer The recessed structure is filled.

In a second aspect, the present application provides a method for preparing a shell, including:

modifying the ceramic particles to obtain modified ceramic particles, wherein the surface of the ceramic particles has a concave structure;

The modified ceramic particles and the polymer are blended, and the injection molding feed is formed through banburying and granulation;

The injection molding feed is injected to obtain a polymer ceramic sheet, and the polymer ceramic sheet is pressed to obtain a polymer ceramic layer to obtain a shell, wherein the polymer fills the concave structure.

In a third aspect, the present application provides an electronic device, including a casing, the casing includes a polymer ceramic layer, the polymer ceramic layer includes ceramic particles and a polymer, and the surface of the ceramic particles has a concave structure, The polymer fills the recessed structures.

Description of drawings

In order to more clearly describe the technical solutions in the embodiments of the present application, the following will describe the drawings that need to be used in the embodiments of the present application.

FIG. 1 is a schematic structural diagram of a casing provided by an embodiment of the present application.

Fig. 2 is a schematic cross-sectional view of ceramic particles provided by an embodiment of the present application.

Fig. 3 is a schematic cross-sectional view of ceramic particles provided by another embodiment of the present application.

Fig. 4 is a schematic structural diagram of a housing provided in another embodiment of the present application.

FIG. 5 is a flowchart of a method for preparing a housing provided in an embodiment of the present application.

FIG. 6 is a flowchart of a method for preparing a housing provided in another embodiment of the present application.

FIG. 7 is a flowchart of a method for preparing a housing provided in another embodiment of the present application.

FIG. 8 is a schematic structural diagram of an electronic device provided by an embodiment of the present application.

FIG. 9 is a schematic diagram of the structure and composition of an electronic device provided by an embodiment of the present application.

FIG. 10 is a schematic diagram of the interior of the casing produced in Example 1.

FIG. 11 is a schematic diagram of the interior of the casing produced in Comparative Example 1. FIG.

detailed description

The following are preferred embodiments of the application. It should be pointed out that for those skilled in the art, without departing from the principle of the application, some improvements and modifications can also be made, and these improvements and modifications are also considered as the present invention. The scope of protection applied for.

The following disclosure provides many different implementations or examples for implementing different structures of the present application. To simplify the disclosure of the present application, components and arrangements of specific examples are described below. Of course, they are examples only and are not intended to limit the application. Furthermore, the present application may repeat reference numerals and/or reference letters in various instances, such repetition is for simplicity and clarity and does not in itself indicate a relationship between the various embodiments and/or arrangements discussed. In addition, various specific process and material examples are provided herein, but one of ordinary skill in the art may recognize the use of other processes and/or the use of other materials.

An embodiment of the present application provides a casing, the casing includes a polymer ceramic layer, the polymer ceramic layer includes ceramic particles and a polymer, the surface of the ceramic particles has a concave structure, and the polymer fills the The concave structure.

Wherein, the particle diameter D50 of the ceramic particles is 0.5 μm-2 μm.

Wherein, the specific surface area of the ceramic particles is greater than or equal to 3m ² /g.

Wherein, the specific surface area of the ceramic particles is 20m ² /g-150m ² /g.

Wherein, the depth of the recessed structure is greater than or equal to 5 nm.

Wherein, the depth of the recessed structure is 5nm-200nm.

Wherein, the concave structure includes at least one of a pit and a hole structure, and the hole structure includes at least one of a through hole and a blind hole.

Wherein, the pore diameter of the pore structure is 20nm-200nm, and the porosity of the ceramic particles is less than or equal to 20%.

Wherein, the porosity of the ceramic particles is 5%-20%.

Wherein, the mass proportion of the ceramic particles in the polymer ceramic layer is 50%-90%, and the mass proportion of the polymer is 10%-50%.

Wherein, the ceramic particles include at least one of ZrO ₂ , Al ₂ O ₃ , TiO ₂ , ZnO, CaCO ₃ , Si ₃ N ₄ , Si, and SiO ₂ , and the polymer includes polyphenylene sulfide, polycarbonate At least one of ester, polyamide, polybutylene terephthalate and polymethyl methacrylate.

Wherein, the refractive index of the ceramic particles is greater than 2.

Wherein, the porosity of the polymer ceramic layer is less than 1%.

Wherein, the housing further includes a protective layer, and the protective layer is arranged on the surface of the polymer ceramic layer.

The embodiment of the present application provides a method for preparing a shell, including: modifying ceramic particles to obtain modified ceramic particles, wherein the surface of the ceramic particles has a concave structure; the modified ceramic particles and a polymer co- Mixing, mixing and granulating to form injection molding feed; the injection molding feed is injection molded to obtain polymer ceramic sheets, and the polymer ceramic sheets are pressed to obtain a polymer ceramic layer to obtain a shell, wherein the polymer filled The recessed structure.

Wherein, providing the ceramic particles includes: pre-treating the ceramic particle precursor to obtain the ceramic particles, wherein the pre-treatment includes at least one of grinding and chemical etching, and the grinding speed in the grinding is 50r/ min-200r/min, the particle size of the grinding beads is 0.5mm-10mm, and the grinding time is less than 30min; the temperature of the chemical etching is 0°C-80°C, and the time is 0.5h-5h.

Wherein, the modification of the ceramic particles includes: mixing the ceramic particles with a surface modifier and drying to obtain the modified ceramic particles, and the mass of the surface modifier accounts for 0.5%- 3%.

Wherein, pressing the polymer ceramic sheet includes: subjecting the polymer ceramic sheet to warm isostatic pressing, the temperature of the warm isostatic pressing is 80°C-300°C, and the temperature of the warm isostatic pressing is as high as At the glass transition temperature of the polymer, the pressure of the warm isostatic pressing is 50MPa-500MPa, and the time of the warm isostatic pressing is 0.5h-2h.

Wherein, heat treatment is also included after the pressing, the temperature of the heat treatment is 100°C-360°C, and the time of the heat treatment is 5h-48h.

An embodiment of the present application provides an electronic device, which is characterized in that it includes a casing, the casing includes a polymer ceramic layer, the polymer ceramic layer includes ceramic particles and a polymer, and the surface of the ceramic particles has depressions structure, the polymer fills the recessed structure.

Please refer to FIG. 1 , which is a schematic structural diagram of a housing provided in an embodiment of the present application. The housing 100 includes a polymer ceramic layer 10, and the polymer ceramic layer 10 includes ceramic particles and polymers. The surface of the ceramic particles has a concave structure, and the polymer ceramic layer 10 includes material to fill the recessed structure.

In this application, the surface of the ceramic particles has a concave structure, which increases the contact area between the polymer and the ceramic particles, and the polymer fills the concave structure, so that the ceramic particles and the polymer are meshed and fixed, which promotes the contact between the ceramic particles and the polymer. The interfacial bonding strength between the polymers improves the strength and toughness of the overall structure, thereby helping to improve the mechanical properties of the housing 100 . In related technologies, the surface of ceramic particles is relatively smooth, the surface friction coefficient is small, and the relative movement resistance is small, which makes separation between ceramic particles and polymers easy, thereby reducing the adhesion strength between the two and the mechanical properties of the overall structure. Performance, the bonding performance between the ceramic particles and the polymer in the shell 100 provided by the present application is good, which improves the mechanical properties of the shell 100 . Compared with plastic shells, the shell 100 provided by this application has ceramic particles, thereby improving the hardness, wear resistance and glossiness of the shell 100, and has a high-grade texture of ceramics, which improves product competitiveness; compared with ceramic shells , the shell 100 provided in the present application has a polymer, which improves the toughness and dielectric properties of the shell 100, while reducing the quality of the shell 100, meeting the need for lightness and thinning.

In the embodiment of the present application, the concave structure includes at least one of a pit and a hole structure. It can be understood that the pits make the surface of the ceramic particles appear uneven, increasing the contact area between the ceramic particles and the polymer; the pore structure makes the ceramic particles have pores, and the polymer can penetrate into the interior of the ceramic particles, increasing the contact area between the ceramic particles and the polymer. The contact area between the objects is improved, the engagement and fixation between the ceramic particles and the polymer is improved, and the adhesion strength of the interface between the ceramic particles and the polymer is improved, thereby helping to improve the mechanical properties of the housing 100 . In the present application, the cross-sectional shape of the opening of the recessed structure may be, but not limited to, a circle, an ellipse, a square, a rectangle, a rhombus, an irregular shape, and the like.

In the present application, the pore structure in the ceramic particles may be a regular structure or an irregular structure. In the embodiments of the present application, the hole structure includes at least one of a through hole and a blind hole. It can be understood that the pore structure on the surface of the ceramic particles in the present application connects the inside of the ceramic particles with the outside of the ceramic particles. In an embodiment of the present application, the pore size of the hole structure is 20 nm-200 nm. Further, the pore size of the hole structure is 50nm-180nm. Furthermore, the pore size of the hole structure is 75nm-150nm. Specifically, the pore size of the hole structure may be, but not limited to, 20nm, 40nm, 65nm, 80nm, 100nm, 115nm, 120nm, 130nm, 145nm or 150nm. The pore size of the above-mentioned pore structure is not only conducive to the embedding of the polymer, but also does not affect the particle strength of the ceramic particles, which is beneficial to the improvement of the performance of the housing 100 . In the present application, the pore structure may include a trunk and at least one branch connected to the trunk, wherein the trunk directly communicates with the exterior of the ceramic particle, and the branch communicates with the exterior of the ceramic particle through the trunk; multiple pore structures may communicate with each other inside the ceramic particle.

In the embodiment of the present application, the porosity of the ceramic particles is less than or equal to 20%. The ceramic particles with the above-mentioned porosity can not only increase the contact area between the polymer and the ceramic particles, improve the adhesion between the polymer and the ceramic particles, but also ensure the particle strength of the ceramic particles. Furthermore, the porosity of the ceramic particles is 5%-20%, which further increases the specific surface area of the ceramic particles, which is beneficial to the improvement of the mechanical properties of the housing 100 . Specifically, the porosity of the ceramic particles may be, but not limited to, 5%, 7%, 9%, 10%, 12%, 13%, 15%, 16%, 17%, 18% or 20%.

Please refer to Fig. 2, which is a schematic cross-sectional view of a ceramic particle provided by an embodiment of the present application, wherein the surface of the ceramic particle has a plurality of pits, so that the ceramic particle presents an uneven effect, improves the roughness of the ceramic particle surface, and increases The contact area between polymer and ceramic particles. Please refer to FIG. 3 , which is a cross-sectional schematic view of ceramic particles provided by another embodiment of the present application, wherein the ceramic particles have a pore structure, and the pore structure includes through holes and blind holes, thereby improving the porosity of the ceramic particles, which is beneficial to the polymer and contact between ceramic particles.

In the embodiment of the present application, the particle size D50 of the ceramic particles is 0.5 μm-2 μm. The ceramic particles with the above particle size are beneficial to improve the delicate texture of the casing 100 and the strength and hardness of the casing 100 . Further, the particle size D50 of the ceramic particles is 0.8 μm-1.7 μm. Furthermore, the particle size D50 of the ceramic particles is 1 μm-1.5 μm. Specifically, the particle size of the ceramic particles may be, but not limited to, 0.5 μm, 0.6 μm, 0.9 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.6 μm or 1.8 μm. In this application, the particle size D50 of ceramic particles can be detected by a laser particle size analyzer. In the present application, the shape of the ceramic particles may be, but not limited to, sphere, spheroid, cube, irregular cube and the like. In an embodiment of the present application, the depth of the recessed structure is greater than or equal to 5 nm. In the present application, the depth of the recessed structure is the maximum vertical distance from the inner wall of the recessed structure to the opening of the recessed structure. It can be understood that when the recessed structure is a through hole, the maximum depth of the through hole is the particle size of the ceramic particle. Furthermore, the depth of the concave structure is 5nm-200nm, which is beneficial to increase the specific surface area of the ceramic particles, increase the contact with the polymer, and improve the interface bonding performance between the ceramic particles and the polymer.

In the embodiment of the present application, the specific surface area of the ceramic particles is greater than or equal to 3m ² /g. In this application, the surface of the ceramic particles has a concave structure, thereby increasing the specific surface area of the ceramic particles, which in turn is beneficial to increase the contact area between the polymer and the ceramic particles and the adhesion strength between the two. In an embodiment of the present application, when the particle diameter D50 of the ceramic particles is 0.5 μm, the specific surface area of the ceramic particles is greater than or equal to 3 m ² /g. Further, when the particle size D50 of the ceramic particles is 0.5 μm, the specific surface area of the ceramic particles is greater than or equal to 5 m ² /g. In another embodiment of the present application, when the surface of the ceramic particle only has pits, the specific surface area of the ceramic particle is greater than or equal to 3 m ² /g. Further, the specific surface area of the ceramic particles is greater than or equal to 5m ² /g. In a specific embodiment, when the surface of the ceramic particle only has pits, the specific surface area of the ceramic particle is 3m ² /g-10m ² /g. In yet another embodiment of the present application, when the surface of the ceramic particle has a pore structure, the specific surface area of the ceramic particle is greater than or equal to 20 m ² /g. Further, the specific surface area of the ceramic particles is 20m ² /g-150m ² /g. In a specific embodiment, when the particle size D50 of the ceramic particles is 0.5 μm, the specific surface area of the ceramic particles is greater than or equal to 20 m ² /g. Specifically, when the surface of the ceramic particles has a porous structure, the specific surface area of the ceramic particles can be, but not limited to, 20m ² /g, 30m ² /g, 40m ² /g, 50m ² /g, 60m ² /g, 70m ² /g g, 80m ² /g, 90m ² /g, 100m ² /g, 120m ² /g, 130m ² /g, 140m ² /g or 150m ² /g, etc. In this application, the GB/T19587-2017 standard is used to detect the specific surface area and porosity of ceramic particles.

In the embodiment of the present application, the mass proportion of ceramic particles in the polymer ceramic layer 10 is 50%-90%. The higher content of ceramic particles in the polymer ceramic layer 10 can improve the surface hardness and enhance the texture of ceramics. In one embodiment, the content of ceramic particles in the polymer ceramic layer 10 is 60%-85%. In another embodiment, the content of ceramic particles in the polymer ceramic layer 10 is 65%-80%. Specifically, the content of ceramic particles in the polymer ceramic layer 10 may be, but not limited to, 55%, 60%, 65%, 70%, 72%, 75%, 80% or 85%. In the embodiment of the present application, the ceramic particles include at least one of ZrO ₂ , Al ₂ O ₃ , TiO ₂ , ZnO, CaCO ₃ , Si ₃ N ₄ , Si and SiO ₂ . The above-mentioned ceramic particles are resistant to high temperature, have high hardness and good strength, and are easy to form a concave structure on the surface, which is beneficial to the improvement of the performance of the casing 100 . In the embodiment of the present application, the refractive index of the ceramic particles is greater than 2. By arranging ceramic particles with a high refractive index, the surface gloss and ceramic texture of the housing 100 are improved, so that the appearance of the housing 100 is closer to a ceramic shell.

In the present application, the polymer in the polymer ceramic layer 10 is cross-linked to form a three-dimensional network structure, which improves the internal bonding force and toughness of the housing 100 . In the embodiment of the present application, the mass proportion of the polymer in the polymer ceramic layer 10 is 10%-50%. Further, the mass proportion of the polymer in the polymer ceramic layer 10 is 10%-35%. Furthermore, the mass proportion of the polymer in the polymer ceramic layer 10 is 15%-30%. Specifically, the mass proportion of the polymer in the polymer ceramic layer 10 can be, but not limited to, 12%, 15%, 18%, 20%, 25%, 32%, 37%, 40%, 45%, 48%, or 50% etc. Using the polymer in the above content can not only improve the toughness inside the casing 100 , reduce the weight of the casing 100 , but also not affect the ceramic texture of the casing 100 . In the embodiment of the present application, the polymer includes at least one of polyphenylene sulfide, polycarbonate, polyamide, polybutylene terephthalate and polymethyl methacrylate. The physical and chemical properties of the above-mentioned polymer can match the preparation process of the housing 100 , and will not decompose during the preparation process, and will not increase the difficulty of the preparation process, which is beneficial to reduce production costs. It can be understood that the materials of the ceramic particles and the polymer can also be selected from other materials not listed above that are suitable for manufacturing the casing 100 .

In the embodiment of the present application, the polymer ceramic layer 10 may also have a colorant, so that the casing 100 has different color appearances and improves the visual effect. Specifically, the coloring agent can be, but not limited to, at least one selected from iron oxide, cobalt oxide, cerium oxide, nickel oxide, bismuth oxide, zinc oxide, manganese oxide, chromium oxide, copper oxide, vanadium oxide and tin oxide. . In one embodiment, the mass content of the colorant in the polymer ceramic layer 10 is less than or equal to 10%, so as to improve the color of the polymer ceramic layer 10 without affecting the content of ceramic particles and polymer. Further, the mass content of the colorant in the polymer ceramic layer 10 is 0.5%-10%.

Please refer to FIG. 4 , which is a schematic structural diagram of a housing provided in another embodiment of the present application. The housing 100 may further include a protective layer 20 disposed on the surface of the polymer ceramic layer 10 . The casing 100 has an inner surface and an outer surface oppositely disposed during use, and the protective layer 20 is located on one side of the outer surface, so as to play a protective role in the use of the casing 100 . Specifically, the protective layer 20 may be, but not limited to, an anti-fingerprint layer, a hardened layer, and the like. Specifically, the thickness of the protection layer 20 may be, but not limited to, 5nm-20nm. In one embodiment, the protection layer 20 includes an anti-fingerprint layer. Optionally, the contact angle of the anti-fingerprint layer is greater than 105°. The contact angle is an important parameter to measure the wettability of the liquid on the surface of the material. The contact angle of the anti-fingerprint layer is greater than 105°, indicating that the liquid is easy to move on the anti-fingerprint layer, thereby avoiding pollution to its surface, and has excellent anti-fingerprint properties. performance. Optionally, the anti-fingerprint layer includes fluorine-containing compounds. Specifically, the fluorine-containing compound may be, but not limited to, fluorosilicone resin, perfluoropolyether, fluorine-containing acrylate, and the like. Further, the anti-fingerprint layer also includes silicon dioxide, and the friction resistance of the anti-fingerprint layer is further improved by adding silicon dioxide. In another embodiment, the protective layer 20 includes a hardened layer. The surface hardness of the casing 100 is further improved by providing a hardened layer. hardened layer. The material of the hardened layer includes at least one of polyurethane acrylate, silicone resin, and perfluoropolyether acrylate.

In this application, the thickness of the housing 100 can be selected according to the needs of its application scenarios, which is not limited; in one embodiment, the housing 100 can be used as the shell, middle frame, decoration, etc. of the electronic device 200, such as As the casing of mobile phones, tablet computers, notebook computers, watches, MP3, MP4, GPS navigators, digital cameras, etc. The casing 100 in the embodiment of the present application may have a 2D structure, a 2.5D structure, a 3D structure, etc., which may be selected according to needs. In one embodiment, when the casing 100 is used as a mobile phone back cover, the thickness of the casing 100 is 0.6mm-1.2mm. Specifically, the thickness of the housing 100 may be, but not limited to, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm or 1.2mm. In another embodiment, when the case 100 is used as the back cover of a mobile phone, the case 100 includes a main body and an extension portion disposed on the edge of the main body, and the extension is bent toward the main body; at this time, the case 100 is curved.

In the present application, the performance of the housing 100 is tested by using a falling ball impact performance test, wherein the falling ball is a 32g stainless steel ball, and the thickness of the housing 100 is 0.8mm. In one embodiment, the housing 100 is supported on the jig, wherein the surrounding edges of the housing 100 are supported by 3 mm, and the middle part is suspended; a 32 g stainless steel ball is freely dropped from a certain height to the surface of the housing 100 to be tested. For the point to be detected, record the height at which the casing 100 is broken as the falling ball height. Further, a 32g stainless steel ball was freely dropped from a certain height to five detection points at the four corners and the center of the surface of the casing 100 to be tested, and the height at which the casing 100 was broken was recorded as the falling ball height. In the embodiment of the present application, the height of the falling ball is greater than or equal to 65 cm. Further, the height of the falling ball is 65cm-110cm. Furthermore, the height of the falling ball is 80cm-110cm.

In this application, the bending strength of the four-point bending of the casing 100 is detected by adopting the GB/T 6569-2006 standard. In the embodiment of the present application, the bending strength of the casing 100 is greater than 400 MPa. Further, the bending strength of the casing 100 is 410MPa-550MPa. Specifically, the bending strength of the casing 100 may be, but not limited to, 420MPa, 450MPa, 470MPa, 500MPa, 520MPa, 530MPa, 540MPa, or 550MPa.

In this application, the porosity of the casing 100 is detected by adopting the GB/T 25995-2010 standard. In the embodiment of the present application, the porosity of the casing 100 is less than 1%. That is, the density of the casing 100 is greater than or equal to 99%. The low porosity of the casing 100 ensures the bonding strength inside the casing 100 , which is beneficial to the improvement of the mechanical properties of the casing 100 . Further, the porosity of the casing 100 is less than 0.5%. The compactness of the casing 100 is further improved.

In the embodiment of the present application, the surface roughness of the casing 100 is less than 0.1 μm. By providing the housing 100 with a small surface roughness, it is beneficial to enhance its ceramic texture, improve the appearance effect, and facilitate the use of the housing 100 . Further, the surface roughness of the casing 100 is 0.02 μm-0.08 μm.

Please refer to FIG. 5 , which is a flowchart of a method for preparing a housing provided in an embodiment of the present application. The method is used to prepare the housing 100 in any of the above embodiments, including:

S101: modifying the ceramic particles to obtain modified ceramic particles, wherein the surface of the ceramic particles has a concave structure.

S102: The modified ceramic particles are blended with the polymer, and then mixed and granulated to form injection molding feed.

S103: The injection molding feed is injected to obtain a polymer ceramic sheet, and the polymer ceramic sheet is pressed to obtain a polymer ceramic layer to obtain a shell, wherein the polymer fills the concave structure.

The preparation method of the shell 100 provided in the present application is simple to operate, easy to produce on a large scale, and can produce the shell 100 with excellent performance, which is beneficial to its application.

In S101, the modification of the ceramic particles can improve the compatibility between the ceramic particles and the polymer, so that the polymer can be completely filled into the concave structure of the ceramic particles, for example, it is beneficial for the polymer to fill the pits and penetrate into the pore structure, etc. As a result, the engagement and fixation between the ceramic particles and the polymer are generated, and the interface adhesion between the two is improved, thereby improving the mechanical properties of the housing 100 .

In the embodiment of the present application, the modification of the ceramic particles includes: mixing the ceramic particles with a surface modifier and drying to obtain the modified ceramic particles. In this application, the surface modifier may include, but is not limited to, at least one of coupling agent, surfactant, silicone, dispersant, etc., and the surface modifier may be selected according to the properties of the polymer. In one embodiment, a coupling agent can be selected for modification. Specifically, the coupling agent may be, but not limited to, a silane coupling agent, a titanate coupling agent, and the like. Further, the surface modifier also includes a dispersant. Specifically, the dispersant can be but not limited to at least one of sodium benzoate, sodium hexametaphosphate and polyethylene glycol. In another embodiment, the mass of the surface modifier accounts for 0.5%-3% of the mass of the ceramic particles, so that the surface modification of the ceramic particles can be completed without causing agglomeration among the surface modifiers. Further, the mass of the surface modifier accounts for 0.7%-2.5% of the mass of the ceramic particles. Specifically, the mass of the surface modifier accounts for 0.8%, 1%, 1.5%, 2%, 2.3%, 2.5%, 2.7% or 3% of the mass of the ceramic particles. For example, the mass of the coupling agent accounts for 0.5%-3% of the mass of the ceramic particles, etc. In a specific embodiment, the modification is carried out by mixing and grinding ceramic particles, surface modifiers and sanding beads. Specifically, the particle size of the sanding beads may be, but not limited to, 0.5 nm-10 nm, and the sanding beads may be, but not limited to, zirconium beads. Further, the grinding includes 300r/min-1500r/min, the number of grinding cycles is 10-100 times, and the grinding time is 5min/cycle-30min/cycle. In another specific embodiment, the surface modifier is dissolved in an alcohol solvent, water or a mixed solvent of alcohol and water, and then ceramic particles are added for mixed sanding and drying.

In S102, the injection molding feed is formed by blending the modified ceramic particles and the polymer, banburying and granulating, which is beneficial to the subsequent injection molding. In one embodiment, the polymer includes at least one of polyphenylene sulfide, polycarbonate, polyamide, polybutylene terephthalate, and polymethyl methacrylate. It can be understood that other suitable polymers for the housing 100 can also be selected. In a specific embodiment, when the polymer is polyphenylene sulfide, a coupling agent with epoxy groups can be selected to modify the ceramic particles, which is more conducive to improving the compatibility between the polymer and the ceramic particles.

It can be understood that when the modified ceramic particles and the polymer are blended, the mixing ratio of the modified ceramic particles and the polymer can be selected according to the content of each substance in the polymer ceramic layer 10 , which is not limited. In one embodiment, the mass ratio of the ceramic particles to the polymer is 1-10, which is beneficial to obtain the polymer ceramic layer 10 with high hardness, good toughness, high gloss and strong ceramic texture. In the embodiment of the present application, the blending includes dry grinding or wet grinding, such as ball mill or sand mill. In one embodiment, the blending is carried out by a dry method, which is beneficial to improve the blending efficiency. In a specific embodiment, the modified ceramic particles, polymer and ball milling beads are placed together in a dry ball mill for grinding for 2h-10h. In this application, banburying and granulation is beneficial to the injection molding process, for example, the blended mixture can be placed in a banburying and granulating integrated machine for banburying and granulation. In one embodiment, the temperature of the mixer granulation is higher than the melting point of the selected polymer and lower than the decomposition temperature of the selected polymer. Specifically, the temperature of banburying and granulation can be but not limited to 200°C-350°C, and the time of banburying and granulation can be but not limited to 1h-12h. Furthermore, the banburying process is in a negative pressure state, and the absolute value of the pressure is less than 0.01MPa, which can effectively prevent the selected polymer from being oxidized, and can effectively promote the removal of gases generated by side reactions.

In S103 , the polymer ceramic layer 10 is obtained by injecting and pressing the injection molding material, and the shell 100 is manufactured.

In this application, the injection molding temperature can be selected according to the properties of the selected polymer. For example, the injection molding temperature can be but not limited to 200°C-350°C; 330°C. The thickness of the polymer ceramic sheet obtained by injection molding can be selected according to needs, and the thickness of the polymer ceramic sheet will be reduced during the subsequent pressing and processing, so the thickness of the polymer ceramic sheet can be increased during injection molding. In this application, the method of injection molding is simpler to operate. Compared with tape casting, there is no need to consider the compatibility between solvents and polymers, and the preparation cost is low. Contact, enhance the adhesion between the two. It can be understood that other molding methods such as tape casting can also be used to prepare polymer ceramic sheets.

In the embodiment of the present application, pressing the polymer ceramic sheet includes performing warm isostatic pressing on the polymer ceramic sheet. The porosity inside the polymer ceramic sheet is reduced by warm isostatic pressing, and the contact area between the ceramic particles and the polymer is increased, which is conducive to the polymer completely filling the concave structure on the surface of the ceramic particles, and improving the contact area between the ceramic particles and the polymer. interface adhesion. Isostatic pressing technology is a technology that uses the products in the closed high-pressure container to form under the uniform ultra-high pressure state in all directions. Isostatic pressing technology is divided into three different types: cold isostatic pressing, warm isostatic pressing, and hot isostatic pressing according to the temperature during forming and consolidation. In this application, the temperature of warm isostatic pressing is higher than the glass transition temperature of the polymer, so that the polymer in the polymer ceramic sheet can be softened, and at the same time, the density is better under pressure, thereby eliminating the polymer ceramic sheet The internal pores improve the bonding force between ceramic particles and polymers. In one embodiment, the pressure of warm isostatic pressing is 50MPa-500MPa, which is conducive to fully compacting the polymer ceramic sheet, and the process has low requirements for equipment, good safety, and is more conducive to practical operation and application . Further, the pressure of warm isostatic pressing is 100MPa-400MPa. In this application, the time of warm isostatic pressing can be selected according to the thickness of the polymer ceramic sheet. In one embodiment, the temperature of warm isostatic pressing is 80°C-300°C, the time of warm isostatic pressing is 0.5h-2h, and the pressure of warm isostatic pressing is 50MPa-500MPa, which can further reduce the Porosity, improve the internal bonding force. In a specific embodiment, the polymer ceramic sheet can be packed into the package, the gas adsorbed on the surface of the green body and the internal space and the package can be sucked out, and then vacuum-sealed and then placed in a pressure vessel with a heating furnace for heating. Isostatic pressing.

Please refer to FIG. 6 , which is a flowchart of a method for preparing a housing provided in another embodiment of the present application. The preparation method prepares the housing 100 of any of the above embodiments, including:

S201: Perform pretreatment on the ceramic particle precursor to obtain ceramic particles, wherein the pretreatment includes at least one of grinding and chemical etching, and the surface of the ceramic particle has a concave structure.

S202: modifying the ceramic particles to obtain modified ceramic particles.

S203: The modified ceramic particles are blended with the polymer, and then mixed and granulated to form injection molding feed.

S204: The injection molding feed is injected to obtain a polymer ceramic sheet, and the polymer ceramic sheet is pressed to obtain a polymer ceramic layer to obtain a shell, wherein the polymer fills the concave structure.

It can be understood that, for detailed descriptions of S202, S203, and S204, refer to descriptions of corresponding parts of S101, S102, and S103 in the foregoing implementation manners, and details are not repeated here.

In S201, the ceramic particle precursor is processed by at least one pretreatment process of grinding and chemical etching, so as to obtain ceramic particles with a concave structure on the surface. It can be understood that the difference between the ceramic particle precursor and the ceramic particle lies in whether it has been pre-treated, the surface of the ceramic particle precursor is relatively smooth, and the specific surface area of the ceramic particle precursor is smaller than that of the ceramic particle. In the present application, the surface state of the ceramic particle precursor is changed through grinding and chemical etching, so that pits and/or hole structures are produced on the ceramic particle precursor to obtain ceramic particles.

In one embodiment of the present application, the ceramic particle precursor is treated by grinding to obtain ceramic particles, and the surface of the ceramic particle has a concave structure. In an embodiment of the present application, the grinding speed is 50r/min-200r/min, the particle size of the grinding beads is 0.5mm-10mm, and the grinding time is less than 30min. Through the above grinding process, ceramic particles with pits on the surface can be obtained, and the grinding time is relatively short, but changing the particle size of the ceramic particles allows the ceramic particles to maintain the original particle size and increase the specific surface area, thus increasing the specific surface area. The contact area between polymers is conducive to improving the adhesion between ceramic particles and polymers. Further, during grinding, the grinding speed is 80r/min-170r/min, the particle size of the grinding beads is 1mm-8mm, and the grinding time is 10min-25min. Furthermore, the grinding speed during grinding is 100r/min-150r/min, the particle size of the grinding beads is 2mm-7mm, and the grinding time is 12min-20min. In an embodiment of the present application, the mass ratio of the ceramic particle precursor to the grinding beads is 1:(2-5), which is beneficial to the sufficient grinding of the ceramic particle precursor and obtains ceramic particles with increased specific surface area. Specifically, the mass ratio of the ceramic particle precursor to the grinding beads may be, but not limited to, 1:2, 1:3, 1:4 or 1:5. In a specific embodiment, the ceramic particle precursor and grinding beads can be placed in a grinding machine for grinding treatment, and the grinding beads can be but not limited to zirconium beads and the like. In the embodiment of the present application, ceramic particles with a particle size D50 of 0.5 μm-2 μm and a specific surface area greater than or equal to 3 m ² /g can be obtained by grinding. Further, the specific surface area of the ceramic particles is 3m ² /g-10m ² /g. In another embodiment of the present application, other grinding processes can also be used, such as increasing the grinding speed, increasing the grinding time, etc., so as to obtain ceramic particles with a pore structure, which will not be repeated here.

In another embodiment of the present application, the ceramic particle precursor is treated by chemical etching to obtain ceramic particles, and the surface of the ceramic particle has a concave structure. In the present application, the surface roughness of the ceramic particle precursor can be increased by chemical etching, and pits and/or hole structures can be produced on the ceramic particle precursor, thereby obtaining ceramic particles. It can be understood that chemical etching is performed by using a chemical etching solution, and the chemical etching solution is selected to be able to chemically react with the ceramic particle precursor, such as acid, lye, etc.; you can choose to slowly chemically react with the ceramic particle precursor. The reacting etchant can better control the slow progress of the etching process. Specifically, the etching solution may be, but not limited to, hydrochloric acid, sulfuric acid, acetic acid, hypochlorous acid, sodium hydroxide, ammonia water, and the like. In a specific embodiment, the precursor of zirconia ceramic particles can be chemically etched with hydrochloric acid or sodium hydroxide, the precursor of alumina ceramic particles can be chemically etched with sodium hydroxide solution or sulfuric acid, and the precursor of zinc oxide ceramic particles Acetic acid or hypochlorous acid can be selected for chemical etching. In the present application, the mixing ratio of the ceramic particle precursor and the chemical etching solution is calculated according to the stoichiometric ratio of the amount of the ceramic particle precursor to be etched and the reaction of the chemical etching solution. In an embodiment of the present application, the temperature of the chemical etching is 0°C-80°C, and the time is 0.5h-5h, which is beneficial to the formation of the pore structure and increases the specific surface area and porosity of the ceramic particles. Further, the chemical etching temperature is 20°C-60°C, and the time is 1h-3.5h. Stirring is maintained during the chemical etching process to facilitate uniform etching of the ceramic particle precursor and obtain ceramic particles with uniform morphology. In a specific embodiment, the ceramic particle precursor is mixed with a chemical etching solution, stirred at 0°C-80°C for 0.5h-5h, filtered and dried to obtain ceramic particles. In the embodiment of the present application, ceramic particles with a particle size D50 of 0.5 μm-2 μm and a specific surface area greater than or equal to 20 m ² /g can be obtained by chemical etching. Further, the specific surface area of the ceramic particles is 20m ² /g-150m ² /g. In another embodiment of the present application, other chemical etching processes may also be used, such as reducing the chemical etching temperature, reducing the chemical etching time, etc., so as to obtain ceramic particles with pits, which will not be repeated here.

It can be understood that the above-mentioned grinding and chemical etching processes are only used as examples to help understand the present application; according to the idea of the present application, those skilled in the art can also obtain the present application through other processes other than the above-mentioned grinding and chemical etching processes. Ceramic particles with a concave structure are also within the protection scope of the present application.

Please refer to FIG. 7 , which is a flow chart of a method for preparing a housing provided in another embodiment of the present application. The preparation method prepares the housing 100 of any of the above embodiments, including:

S301: modifying the ceramic particles to obtain modified ceramic particles, wherein the surface of the ceramic particles has a concave structure.

S302: Modified ceramic particles and polymers are blended, and then mixed and granulated to form injection molding feed.

S303: The injection molding feed is injected to obtain a polymer ceramic sheet, and after the polymer ceramic sheet is pressed together, heat treatment is performed to obtain a polymer ceramic layer, and a shell is prepared, wherein the polymer fills the concave structure.

It can be understood that, for detailed descriptions of S301 and S302, refer to the descriptions of corresponding parts of S101 and S102 in the foregoing implementation manners, and details are not repeated here.

In S303, heat treatment is also included after the pressing. Heat treatment further promotes chain extension, crosslinking and other reactions of polymer molecular chains, realizes effective control of crystallinity and crosslinking degree, and further improves strength and toughness. In this application, the heat treatment temperature is determined by the specific crystallization, crosslinking, and degradation properties of the selected polymer; for example, the heat treatment temperature is greater than the melting temperature of the polymer and less than the decomposition temperature of the polymer. In one embodiment, the heat treatment temperature is 100°C-360°C, and the heat treatment time is 5h-48h. In a specific embodiment, when the polymer is polyphenylene sulfide, heat treatment may be performed, the heat treatment temperature is 100°C-360°C, and the heat treatment time is 5h-48h. Further, the heat treatment temperature is 270°C-360°C. Specifically, the heat treatment can be carried out in an inert atmosphere or in air to cause oxidative cross-linking.

In an embodiment of the present application, the manufacturing method of the housing 100 further includes performing computer digital control precision machining (CNC machining) on the housing 100 . The housing 100 with the final required assembly size is obtained through CNC machining. For example, the casing 100 is made flatter by CNC machining. In another embodiment of the present application, the manufacturing method of the housing 100 further includes grinding the housing 100 . By polishing and grinding the surface of the housing 100 , the roughness of the surface of the housing 100 is reduced, and the ceramic texture of the surface of the housing 100 is improved. In one embodiment, the surface roughness of the casing 100 is less than 0.1 μm. By providing the casing 100 with a small surface roughness, it is beneficial to enhance its surface gloss and ceramic texture, and improve the visual effect. Further, the surface roughness of the casing 100 is 0.02 μm-0.08 μm.

In an embodiment of the present application, the manufacturing method of the casing 100 further includes spraying or evaporating a protective material on the surface of the polymer ceramic layer 10 to form the protective layer 20 . In one embodiment, an anti-fingerprint layer is formed by vapor-depositing an anti-fingerprint material on the surface of the polymer ceramic layer 10 to improve the anti-fingerprint effect of the casing 100 .

The present application also provides an electronic device 200, including the housing 100 in any one of the above-mentioned implementation manners. It can be understood that the electronic device 200 may be, but not limited to, a mobile phone, a tablet computer, a notebook computer, a watch, an MP3, an MP4, a GPS navigator, a digital camera, and the like. Please refer to FIG. 8 , which is a schematic structural diagram of an electronic device provided in an embodiment of the present application, wherein the electronic device 200 includes a casing 100 . The casing 100 can improve the mechanical properties of the electronic device 200, and the electronic device 200 has a ceramic-like appearance, which has excellent product competitiveness. Please refer to FIG. 9 , which is a schematic diagram of the structure and composition of an electronic device provided in an embodiment of the present application. The structure of the electronic device 200 may include an RF circuit 210, a memory 220, an input unit 230, a display unit 240, a sensor 250, an audio circuit 260, a WiFi Module 270, processor 280, power supply 290 and so on. Wherein, RF circuit 210 , memory 220 , input unit 230 , display unit 240 , sensor 250 , audio circuit 260 , and WiFi module 270 are respectively connected to processor 280 ; power supply 290 is used to provide electric energy for the entire electronic device 200 . Specifically, the RF circuit 210 is used for sending and receiving signals; the memory 220 is used for storing data instruction information; the input unit 230 is used for inputting information, and may specifically include other input devices such as a touch panel and operation buttons; the display unit 240 may include a display screen, etc.; sensor 250 includes an infrared sensor, a laser sensor, etc., and is used to detect user approach signals, distance signals, etc.; speaker 261 and microphone 262 are connected to processor 280 through audio circuit 260, and are used to receive and send sound signals; WiFi module 270 It is used to receive and transmit WiFi signals; the processor 280 is used to process data information of the electronic device 200 .

The preparation method of the casing provided by the implementation of the present application and the performance of the obtained casing will be further described below through specific examples and comparative examples.

Example 1

A shell comprising Al ₂ O ₃ and polyphenylene sulfide (PPS), wherein the mass proportion of Al ₂ O ₃ in the shell is 60%, the particle size D50 of Al ₂ O ₃ is 0.8 μm, and the prepared shell The bulk Al ₂ O ₃ has undergone chemical etching treatment, and its surface has a porous structure, the specific surface area of Al ₂ O ₃ is 35m ² /g, and the porosity of Al ₂ O ₃ is 8%. Please refer to Figure 10, which is a schematic diagram of the interior of the shell prepared in Example 1, wherein the Al ₂ O ₃ particles have a porous structure, the Al ₂ O ₃ particles are uniformly dispersed in polyphenylene sulfide, and the polyphenylene sulfide is embedded in the porous structure .

Example 2

A shell comprising Al ₂ O ₃ and polyphenylene sulfide, wherein the mass proportion of Al ₂ O ₃ in the shell is 60%, the particle size D50 of Al ₂ O ₃ is 0.8 μm, and the Al The ₂ O ₃ has been ground and has pits on its surface, the specific surface area of Al ₂ O ₃ is 4.1m ² /g, and the porosity of Al ₂ O ₃ is 0.5%.

Example 3

A shell comprising Al ₂ O ₃ and polyphenylene sulfide, wherein the mass proportion of Al ₂ O ₃ in the shell is 60%, the particle size D50 of Al ₂ O ₃ is 0.8 μm, and the Al ₂ O ₃ has Pore structure, the specific surface area of Al ₂ O ₃ is 56m ² /g, and the porosity of Al ₂ O ₃ is 14%.

Example 4

A shell comprising Al ₂ O ₃ and polyphenylene sulfide, wherein the mass proportion of Al ₂ O ₃ in the shell is 60%, the particle size D50 of Al ₂ O ₃ is 0.8 μm, and the Al ₂ O ₃ has Pore structure, the specific surface area of Al ₂ O ₃ is 81m ² /g, and the porosity of Al ₂ O ₃ is 20%.

Example 5

A shell comprising Al ₂ O ₃ and polyphenylene sulfide, wherein the mass proportion of Al ₂ O ₃ in the shell is 60%, the particle size D50 of Al ₂ O ₃ is 0.8 μm, and the Al ₂ O ₃ has Pore structure, the specific surface area of Al ₂ O ₃ is 56m ² /g, and the porosity of Al ₂ O ₃ is 30%.

Comparative example 1

A shell comprising Al ₂ O ₃ and polyphenylene sulfide, wherein the mass proportion of Al ₂ O ₃ in the shell is 60%, the particle size D50 of Al ₂ O ₃ is 0.8 μm, and the Al The surface of ₂ O ₃ is smooth without pretreatment, the specific surface area of Al ₂ O ₃ is 2.2m ² /g, and the porosity of Al ₂ O ₃ is 0.2%. Please refer to FIG. 11 , which is a schematic diagram of the interior of the shell prepared in Comparative Example 1, in which the Al ₂ O ₃ particles have a smooth surface, and the Al ₂ O ₃ particles are uniformly dispersed in polyphenylene sulfide.

performance testing

Adopt GB/T 6569-2006 to carry out four-point bending test to the housing provided by the above-mentioned embodiment and comparative example, obtain the bending strength of the housing; provide the housing in the above-mentioned embodiment and comparative example, and the housing size is 150mm ×73mm×0.8mm, respectively support the above-mentioned shells on the jig (the four sides are supported by 3mm, and the middle part is suspended), and use 32g stainless steel balls to freely fall from a certain height to the surface to be tested. There are five shells in the four corners and the center. Each point is measured 5 times until it is broken, and the height of the falling ball is recorded. The test results are shown in Table 1.

Table 1 performance test results

the	抗弯强度/MPaBending strength/MPa	落球高度/cmFalling ball height/cm
实施例1Example 1	450450	8080
实施例2Example 2	410410	6565
实施例3Example 3	500500	9090
实施例4Example 4	530530	9595
实施例5Example 5	460460	8282
对比例1Comparative example 1	360360	6060

The Al ₂ O ₃ used in the examples of this application has been pre-treated. The surface of the Al ₂ O ₃ has a pit or hole structure, and the resulting shell has high bending strength and a large falling ball height, and the shell has excellent strength. and toughness. In Comparative Example 1, untreated Al ₂ O ₃ was used, and the performance of the shell produced was lower than that of the shell produced in the embodiment of the present application. Therefore, compared with the comparative example, the housing provided by the present application has excellent mechanical properties, which is beneficial to its application.

The content provided by the implementation of the application has been introduced in detail above, and the principle and implementation of the application have been described and explained in this paper. The above description is only used to help understand the method and core idea of the application; at the same time, for those in the field Ordinary technicians, based on the idea of this application, will have changes in specific implementation methods and application ranges. In summary, the content of this specification should not be construed as limiting this application.

Claims

A housing, characterized in that the housing includes a polymer ceramic layer, the polymer ceramic layer includes ceramic particles and polymers, the surface of the ceramic particles has a concave structure, and the polymer fills the depressions structure.
The housing according to claim 1, wherein the particle size D50 of the ceramic particles is 0.5 μm-2 μm.
The casing according to claim 1, wherein the specific surface area of the ceramic particles is greater than or equal to 3m 2 /g.
The casing according to claim 3, wherein the specific surface area of the ceramic particles is 20m 2 /g-150m 2 /g.
The casing according to claim 1, wherein the depth of the concave structure is greater than or equal to 5 nm.
The casing according to claim 5, wherein the depth of the recessed structure is 5nm-200nm.
The casing according to claim 1, wherein the concave structure comprises at least one of a pit and a hole structure, and the hole structure comprises at least one of a through hole and a blind hole.
The casing according to claim 7, wherein the pore structure has a pore diameter of 20nm-200nm, and the porosity of the ceramic particles is less than or equal to 20%.
The casing according to claim 8, wherein the porosity of the ceramic particles is 5%-20%.
The housing according to claim 1, wherein the mass proportion of the ceramic particles in the polymer ceramic layer is 50%-90%, and the mass proportion of the polymer is 10%-50%. .
The housing according to claim 1, wherein the ceramic particles comprise at least one of ZrO 2 , Al 2 O 3 , TiO 2 , ZnO, CaCO 3 , Si 3 N 4 , Si and SiO 2 , The polymer includes at least one of polyphenylene sulfide, polycarbonate, polyamide, polybutylene terephthalate and polymethyl methacrylate.
The casing of claim 1, wherein the ceramic particles have a refractive index greater than 2.
The housing of claim 1, wherein the polymer ceramic layer has a porosity of less than 1%.
The casing according to claim 1, characterized in that the casing further comprises a protective layer, and the protective layer is disposed on the surface of the polymer ceramic layer.
A method for preparing a shell, characterized in that it comprises:

modifying the ceramic particles to obtain modified ceramic particles, wherein the surface of the ceramic particles has a concave structure;

The modified ceramic particles and the polymer are blended, and the injection molding feed is formed through banburying and granulation;

The injection molding feed is injected to obtain a polymer ceramic sheet, and the polymer ceramic sheet is pressed to obtain a polymer ceramic layer to obtain a shell, wherein the polymer fills the concave structure.
The preparation method according to claim 15, wherein providing the ceramic particles comprises:

The ceramic particle precursor is pretreated to obtain the ceramic particles, wherein the pretreatment includes at least one of grinding and chemical etching, the grinding speed in the grinding is 50r/min-200r/min, and the grinding beads The particle size is 0.5mm-10mm, and the grinding time is less than 30min; the temperature of the chemical etching is 0°C-80°C, and the time is 0.5h-5h.
The preparation method according to claim 15, wherein the modification of the ceramic particles comprises:

The modified ceramic particles are obtained by mixing the ceramic particles with a surface modifying agent and drying, and the mass of the surface modifying agent accounts for 0.5%-3% of the mass of the ceramic particles.
The preparation method according to claim 15, wherein pressing the polymer ceramic sheet comprises: performing warm isostatic pressing on the polymer ceramic sheet, and the temperature of the warm isostatic pressing is 80°C-300°C. °C, and the temperature of the warm isostatic pressing is higher than the glass transition temperature of the polymer, the pressure of the warm isostatic pressing is 50MPa-500MPa, and the time of the warm isostatic pressing is 0.5h-2h.
The preparation method according to claim 18, further comprising heat treatment after the pressing, the temperature of the heat treatment is 100°C-360°C, and the time of the heat treatment is 5h-48h.
An electronic device, characterized in that it includes a casing, the casing includes a polymer ceramic layer, the polymer ceramic layer includes ceramic particles and a polymer, the surface of the ceramic particles has a concave structure, and the polymer ceramic layer The recessed structure is filled.