1. A polymer-matrix composite, wherein the polymer-matrix composite comprises: ceramic powder, a coupling agent, a low molecular weight polymer and a chain extender;

the additive amount of the coupling agent is 0.5-3% of the weight of the ceramic powder, the additive amount of the low-molecular-weight polymer is 5-20% of the weight of the ceramic powder, and the additive amount of the chain extender is 0.5-3% of the weight of the ceramic powder.

2. Polymer-matrix composite material according to claim 1,

the low molecular weight polymer has a melt index greater than 1000 g/min.

3. The polymer-matrix composite according to claim 1, wherein the ceramic powder is selected from Al₂O₃、ZrO₂、Si₃N₄、SiO₂At least one of;

the coupling agent is selected from at least one of silane coupling agent and titanate coupling agent;

the low molecular weight polymer is selected from at least one of polyphenylene sulfide, polycarbonate and polyamide;

the chain extender is selected from at least one of isocyanate compounds, oxazoline compounds, epoxides, diacid anhydride compounds and diacid halide compounds.

4. A method of making a polymer matrix composite, the method comprising:

mixing ceramic powder with a coupling agent to obtain modified ceramic powder, wherein the coupling agent is used for modifying the surface of the ceramic powder, and the addition amount of the coupling agent is 0.5-3% of the weight of the ceramic powder;

mixing modified ceramic powder, a low molecular weight polymer and a chain extender, wherein the chain extender is used for chain extension of the low molecular weight polymer to obtain a mixture, the addition amount of the low molecular weight polymer is 5-20% of the weight of the ceramic powder, and the addition amount of the chain extender is 0.5-3% of the weight of the ceramic powder;

and co-extruding and granulating the mixture to obtain the polymer matrix composite material.

5. The production method according to claim 4,

the low molecular weight polymer has a melt index greater than 1000 g/min.

6. The method according to claim 4, wherein the ceramic powder is selected from Al₂O₃、ZrO₂、Si₃N₄、SiO₂At least one of;

the coupling agent is selected from at least one of silane coupling agent and titanate coupling agent;

the low molecular weight polymer is selected from at least one of polyphenylene sulfide, polyethylene terephthalate, polycarbonate and polyamide;

the chain extender is selected from at least one of isocyanate compounds, oxazoline compounds, epoxides, diacid anhydride compounds and diacid halide compounds.

7. A method of making a structural member, the method comprising:

shaping a polymer matrix composite material to obtain a green body, wherein the polymer matrix composite material is the polymer matrix composite material as defined in any one of claims 1 to 3 or a binder prepared by the preparation method as defined in any one of claims 4 to 6; and

carrying out warm isostatic pressing on the green body, wherein the low molecular weight polymer in the green body is densified to obtain a densified green body;

and heating the densified green compact, wherein the low molecular weight polymer in the green compact is subjected to a molecular chain extension reaction to obtain a rough blank of the structural member.

8. The production method according to claim 7, wherein the molding process includes injection molding, tape casting, or dry press molding.

9. The preparation method according to claim 8, wherein in the step of molding the polymer matrix composite material to obtain the green body, the injection molding temperature is 200 to 350 ℃.

10. The method according to claim 7, wherein in the step of subjecting the green compact to warm isostatic pressing, the pressing temperature is 80 to 300 ℃ and the pressing pressure is 50 to 500 MPa.

11. The method according to claim 7, wherein in the step of subjecting the densified green body to a temperature raising treatment, the temperature of the temperature raising treatment is 220 to 300 ℃.

12. The production method according to claim 11,

when the low-molecular-weight polymer is polyamide 11 and the chain extender is bisoxazoline, the temperature of the heating treatment is 220-250 ℃;

when the low-molecular-weight polymer is polyethylene terephthalate and the chain extender is 1, 3-phenylene-bis (2-oxazoline), the temperature of the heating treatment is 270-290 ℃;

when the low molecular weight polymer is polyphenylene sulfide and the chain extender is diphenylmethane diisocyanate, the temperature of the heating treatment is 280-300 ℃.

13. The method of manufacturing according to claim 7, further comprising:

carrying out CNC machining on the rough blank to obtain a blank body;

and polishing the blank body, and/or forming a fingerprint-resistant coating on the outer surface of the blank body.

14. A structural member produced by the production method according to any one of claims 7 to 13.

15. A structural member, comprising:

a blank body, which is prepared by carrying out molding treatment, warm isostatic pressing and heating treatment on a polymer-based composite material, wherein the polymer-based composite material is the polymer-based composite material as defined in any one of claims 1 to 3 or a binder prepared by the preparation method as defined in any one of claims 4 to 6;

and the fingerprint-resistant coating is formed on the outer surface of the blank body.

16. The structural member according to claim 15, wherein the thickness of the fingerprint-resistant coating is 5-20 nm, the water contact angle of the fingerprint-resistant coating is larger than 105 degrees, and the fingerprint-resistant coating is made of perfluoropolyether compounds.

17. An electronic device comprising the structural member of claim 14 or any one of claims 15 to 16.

18. The structure of claim 17, wherein the structure is at least one of a battery back cover, a center frame, an integrated housing, a volume key, and a power key.

Background

The ceramic material has the properties of high strength, high gloss, high fracture toughness, excellent heat insulation, high temperature resistance, wear resistance and the like, and can be widely applied to electronic equipment, such as a base material of a structural member of the electronic equipment, and particularly, the ceramic material can be used as a base material of a rear cover and a middle frame of a battery. In particular, the ceramic material has low dielectric constant, does not shield signals and is a structural material with good 5G communication.

However, the disadvantages of ceramic materials are also evident: firstly, the ceramic has high density, and a shell prepared by the ceramic is heavy, so that the ceramic is not beneficial to being applied to electronic equipment requiring light weight; secondly, ceramic materials are fragile, CNC processing time is long, cost is high, yield is low, and complex three-dimensional structures are difficult to make.

Disclosure of Invention

The present application is directed to solving, at least to some extent, one of the technical problems in the related art.

In a first aspect of the present application, there is provided a polymer-based composite comprising: ceramic powder, a coupling agent, a low molecular weight polymer and a chain extender; wherein the adding amount of the coupling agent is 0.5-3% of the weight of the ceramic powder, the adding amount of the low molecular weight polymer is 5-20% of the weight of the ceramic powder, and the adding amount of the chain extender is 0.5-3% of the weight of the ceramic powder.

In a second aspect of the present application, there is provided a method of making a polymer matrix composite, the method comprising: mixing ceramic powder with a coupling agent to obtain modified ceramic powder, wherein the coupling agent is used for modifying the surface of the ceramic powder, and the addition amount of the coupling agent is 0.5-3% of the weight of the ceramic powder; mixing modified ceramic powder, a low molecular weight polymer and a chain extender, wherein the chain extender is used for chain extension of the low molecular weight polymer to obtain a mixture, wherein the addition amount of the low molecular weight polymer is 5-20% of the weight of the ceramic powder, and the addition amount of the chain extender is 0.5-3% of the weight of the ceramic powder; and co-extruding and granulating the mixture to obtain the polymer matrix composite material.

In a third aspect of the present application, a method of making a structural member is presented, the method comprising: molding the polymer matrix composite material to obtain a green body, wherein the polymer matrix composite material is the polymer matrix composite material or the binder prepared by the preparation method; and carrying out warm isostatic pressing on the green body, wherein the low molecular weight polymer in the green body is densified to obtain a densified green body; and (3) heating the densified green body, wherein the low molecular weight polymer in the green body is subjected to a molecular chain extension reaction to obtain a green body of the structural member.

In a fourth aspect of the present application, a structural member is provided, the structural member being made by a method of manufacture as described above.

In a fifth aspect of the present application, a structural member is presented, the structural member comprising: the blank is prepared by molding, warm isostatic pressing and heating the polymer matrix composite material, wherein the polymer matrix composite material is the polymer matrix composite material or the binder prepared by the preparation method; and the fingerprint-resistant coating is formed on the outer surface of the blank.

In a sixth aspect of the present application, the present application proposes an electronic device comprising a structural member as described above.

The technical scheme provided by the embodiment of the application can bring the following beneficial effects:

the polymer matrix composite of the present application comprises: the composite material comprises ceramic powder, a coupling agent, a low molecular weight polymer and a chain extender, wherein the low molecular weight polymer has the characteristics of low density, low hardness, low melting point, good fluidity and the like, so that the composite material has low density, can be applied to electronic equipment requiring light weight, can reduce the subsequent processing difficulty, and is easy to prepare complex and various three-dimensional structural parts. Meanwhile, due to the addition of the chain extender, the chain extension increasing reaction of the low molecular weight polymer can be promoted under certain conditions, so that the high molecular weight polymer of a three-dimensional network is formed, the ceramic texture of the structural member is realized, the integral toughness of the structural member can be improved, and the impact strength of the structural member is high. Compared with the prior art, the problems of poor fluidity, difficulty in injection molding and the like caused by too high molecular weight and too high viscosity of the high molecular polymer when the high molecular polymer and the filler are directly blended and injected are solved, and compared with a pure ceramic shell, the structural member prepared from the polymer-based composite material has the advantages of light weight, low cost, adaptability to a complex three-dimensional structure, good dielectric property and the like.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts. Wherein:

FIG. 1 is a schematic flow chart illustrating one embodiment of a method for preparing a polymer matrix composite according to the present application;

FIG. 2 is a schematic flow chart of a first embodiment of a method for making a structural member according to the present application;

FIG. 3 is a schematic flow chart of a second embodiment of a method for making a structural member according to the present application;

FIG. 4 is a schematic flow chart of a third embodiment of a method for making a structural member according to the present application;

FIG. 5 is a schematic flow chart of a fourth embodiment of a method for making a structural member according to the present application;

fig. 6 is a schematic structural diagram of an electronic device according to the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In one aspect of the present application, there is provided a polymer matrix composite comprising: ceramic powder, a coupling agent, a low molecular weight polymer and a chain extender. Wherein the adding amount of the coupling agent is 0.5-3% of the weight of the ceramic powder, the adding amount of the low molecular weight polymer is 5-20% of the weight of the ceramic powder, and the adding amount of the chain extender is 0.5-3% of the weight of the ceramic powder.

The chain extender is a substance which can react with functional groups on the linear low molecular weight polymer chain to expand the molecular chain and increase the molecular weight. The coupling agent is a substance which can modify the surface of the ceramic powder so that the ceramic powder is easier to be connected with the low molecular weight polymer.

In the long-term research and development process, the inventor finds that incomplete modification of the surface of the ceramic powder can be caused by too low addition amount of the coupling agent, and the multilayer coupling agent molecular layer can be deposited on the surface of the ceramic powder and is easy to form coupling agent agglomeration and precipitation due to too high addition amount of the coupling agent. Therefore, the amount of the coupling agent is preferably controlled to 0.5 to 3% by weight based on the weight of the ceramic powder.

In the long-term research and development process, the inventor of the application finds that the low-molecular-weight polymer has sufficiently low melt viscosity, so that the low-molecular-weight polymer still has good fluidity after being blended with ceramic powder, and is convenient for subsequent injection molding. Therefore, the melt index of the low molecular weight polymer is more than 1000g/min most preferably.

Specifically, the ceramic powder in the above embodiments may be selected from Al₂O₃、ZrO₂、Si₃N₄、SiO₂At least one of (1).

The coupling agent in the above embodiments is at least one selected from a silane coupling agent and a titanate coupling agent.

The low molecular weight polymer in the above embodiments is selected from at least one of polyphenylene sulfide, polyethylene terephthalate, polycarbonate, and polyamide. Wherein the polymerization degree of the low molecular weight polymer is 1 to 100.

The chain extender in the above embodiment is at least one selected from the group consisting of isocyanate compounds, oxazoline compounds, epoxides, diacid anhydride compounds and diacid halide compounds.

In the above embodiment, the polymer matrix composite further comprises: the sinterable pigment is a colored glaze, a powder color material or an enamel color material. It should be noted that the sinterable pigment includes, but is not limited to, conventional high-temperature colored glaze, low-temperature colored glaze, pastel and enamel color, and any sinterable pigment that can be sintered in a kiln is intended to be within the scope of the present application.

The polymer matrix composite of the present application comprises: the composite material comprises ceramic powder, a coupling agent, a low molecular weight polymer and a chain extender, wherein the low molecular weight polymer has the characteristics of low density, low hardness, low melting point, good fluidity and the like, so that the composite material has low density, can be applied to electronic equipment requiring light weight, can reduce the subsequent processing difficulty, and is easy to prepare complex and various three-dimensional structural parts. Meanwhile, due to the addition of the chain extender, the chain extension increasing reaction of the low molecular weight polymer can be promoted under certain conditions, so that the high molecular weight polymer of a three-dimensional network is formed, the ceramic texture of the structural member is realized, the integral toughness of the structural member can be improved, and the impact strength of the structural member is high. Compared with the prior art, the problems of poor fluidity, difficulty in injection molding and the like caused by too high molecular weight and too high viscosity of the high molecular polymer when the high molecular polymer and the filler are directly blended and injected are solved, and compared with a pure ceramic shell, the structural member prepared from the polymer-based composite material has the advantages of light weight, low cost, adaptability to a complex three-dimensional structure, good dielectric property and the like.

In one aspect, the present application provides a method for preparing a polymer matrix composite, referring to fig. 1, the method comprising the steps of:

s11: and mixing the ceramic powder with a coupling agent to obtain the modified ceramic powder.

The coupling agent is used for modifying the surface of the ceramic powder, and the addition amount of the coupling agent is 0.5-3% of the weight of the ceramic powder.

Specifically, the ceramic powder is modified by a coupling agent, and the specific modification method comprises the following steps: dissolving a coupling agent in a solvent (the solvent can be alcohol, water or an alcohol-water mixed solvent), adding the prepared coupling agent solution into the ceramic powder, wherein the addition amount of the coupling agent is 0.5-3% of the weight of the ceramic powder, fully stirring, mixing and standing, filtering out supernatant to obtain modified ceramic powder, cleaning the modified ceramic powder with the solvent, and drying and grinding the modified ceramic powder for later use.

S12: and mixing the modified ceramic powder, the low molecular weight polymer and a chain extender, wherein the chain extender is used for chain extension of the low molecular weight polymer to obtain a mixture.

Wherein the addition amount of the low molecular weight polymer is 5-20% of the weight of the ceramic powder, and the addition amount of the chain extender is 0.5-3% of the weight of the ceramic powder.

S13: and co-extruding and granulating the mixture to obtain the polymer matrix composite material.

Specifically, the blended modified ceramic powder, low molecular weight polymer and chain extender are put into a high-speed stirrer to be stirred so as to be uniformly mixed. And then carrying out melt reaction extrusion on the mixture by using a parallel double-screw extruder to obtain the polymer-based composite material.

Wherein the low molecular weight polymer has a melt index greater than 1000 g/min.

Wherein the ceramic powder is selected from Al₂O₃、ZrO₂、Si₃N₄、SiO₂The coupling agent is at least one of silane coupling agent and titanate coupling agent, the low molecular weight polymer is at least one of polyphenylene sulfide, polyethylene terephthalate, polycarbonate and polyamide, and the chain extender is at least one of isocyanate compound, oxazoline compound, epoxide, diacid anhydride compound and diacid halide compound.

In one aspect of the present application, a method of making a structural member is provided, referring to fig. 2, the method comprising:

s21: and (3) forming the polymer matrix composite material to obtain a green body.

Wherein, the polymer-based composite material is the polymer-based composite material in the above embodiment or the binder prepared by the preparation method in the above embodiment.

S22: and (3) carrying out warm isostatic pressing on the green body, wherein the low molecular weight polymer in the green body is densified to obtain the densified green body.

S23: and (3) heating the densified green body, wherein the low molecular weight polymer in the green body is subjected to a molecular chain extension reaction to obtain a rough blank of the structural member.

The molding process in step S21 includes injection molding, tape casting, or dry pressing.

Specifically, the dry press molding process comprises placing the pelletized polymer-based composite material in a mold, pressing on a press machine to bring the polymer-based composite material close to each other in the mold, and firmly bonding the polymer-based composite material by internal friction to form a green body of a certain shape. The dry pressing forming process has the advantages of high production efficiency, less labor, low rejection rate, short production period, high density and strength of the produced products, suitability for large-scale industrial production and the like.

The tape casting is to make the polymer-based composite material into slurry with certain viscosity, make the slurry flow down from the container, and to be scraped and coated on a special belt by a scraper with certain thickness, after drying and curing, to peel off the film to form a green belt, and then to make the green belt undergo the processing treatments of punching, laminating, etc. according to the size and shape of the finished product, to make the green body to be sintered.

The injection molding is to heat the polymer matrix composite material to a molten state, and inject the heated polymer matrix composite material into an injection mold to form a green body to be sintered.

After the green body is formed by any one of the processes, the formed green body is sintered to obtain a rough blank of the structural member.

In one embodiment, referring to fig. 3, the method for manufacturing the structural member includes the following steps:

s21: and (3) forming the polymer matrix composite material to obtain a green body.

Wherein, the polymer-based composite material is the polymer-based composite material in the above embodiment or the binder prepared by the preparation method in the above embodiment.

S22: and (3) carrying out warm isostatic pressing on the green body, wherein the low molecular weight polymer in the green body is densified to obtain the densified green body.

S23: and (3) heating the densified green body, wherein the low molecular weight polymer in the green body is subjected to a molecular chain extension reaction to obtain a rough blank of the structural member.

S24: and carrying out CNC (computer numerical control) processing on the rough blank to obtain a blank body.

S25: and polishing the blank.

In one embodiment, referring to fig. 4, the method for manufacturing the structural member includes the following steps:

s21: and (3) forming the polymer matrix composite material to obtain a green body.

Wherein, the polymer-based composite material is the polymer-based composite material in the above embodiment or the binder prepared by the preparation method in the above embodiment.

S22: and (3) carrying out warm isostatic pressing on the green body, wherein the low molecular weight polymer in the green body is densified to obtain the densified green body.

S23: and (3) heating the densified green body, wherein the low molecular weight polymer in the green body is subjected to a molecular chain extension reaction to obtain a rough blank of the structural member.

S24: and carrying out CNC (computer numerical control) processing on the rough blank to obtain a blank body.

S26: forming a fingerprint resistant coating on the outer surface of the blank.

In one embodiment, referring to fig. 5, the method for manufacturing the structural member includes the following steps:

s21: and (3) forming the polymer matrix composite material to obtain a green body.

Wherein, the polymer-based composite material is the polymer-based composite material in the above embodiment or the binder prepared by the preparation method in the above embodiment.

S22: and (3) carrying out warm isostatic pressing on the green body, wherein the low molecular weight polymer in the green body is densified to obtain the densified green body.

S23: and (3) heating the densified green body, wherein the low molecular weight polymer in the green body is subjected to a molecular chain extension reaction to obtain a rough blank of the structural member.

S24: and carrying out CNC (computer numerical control) processing on the rough blank to obtain a blank body.

S25: and polishing the blank.

S26: forming a fingerprint resistant coating on the outer surface of the blank.

In the present application, "outer surface" refers to an appearance surface of the structural member, i.e., a surface that can be observed by human eyes after the structural member is assembled in an electronic device.

In some embodiments, in step S21, the polymer-matrix composite material is heated to a molten state and injected into an injection mold to form a green body to be sintered. The injection temperature during injection molding is 200-350 ℃, for example 200 ℃, 250 ℃, 300 ℃ or 350 ℃, and injection molding is carried out at different injection temperatures according to different low molecular weight polymers.

In some embodiments, the green compact is placed in a capsule, the gas adsorbed on the surface and the internal voids of the green compact and the capsule is removed, and the green compact is placed in a pressure vessel with a heating furnace for isostatic pressing after vacuum sealing in step S22. The inventors of the present invention have found that the pressing temperature of the static pressing needs to be higher than the glass transition temperature of the low molecular weight polymer, so that the low molecular weight polymer in the green body can be softened at the pressing temperature and densified under pressure, which helps to eliminate the pores in the polymer matrix composite system and enhance the acting force between the modified ceramic powder and the low molecular weight polymer, and therefore, the pressing temperature should be controlled to be between 80 ℃ and 300 ℃, for example, 80 ℃, 100 ℃, 150 ℃, 200 ℃, 250 ℃, 300 ℃ or 350 ℃, and the pressing temperature is selected according to the specific low molecular weight polymer. Further, the present inventors have found that it is difficult to sufficiently compact the green body when the pressing pressure is too low, and that too high a pressing pressure has little value for compacting the green body but high equipment requirements and an increased operational risk factor, and therefore the pressing pressure should be controlled to be between 50 and 500MPa, for example, 50MPa, 100MPa, 150MPa, 200MPa, 300MPa, 400MPa or 500 MPa.

In some embodiments, in the step S23, in the step of heating the densified green body, the temperature of the heating process is 220 to 300 ℃. Specifically, the temperature rise treatment temperature used differs for different chain extenders and low molecular weight polymers. For example, when the low molecular weight polymer is polyamide 11 and the chain extender is bisoxazoline, the temperature of the heating treatment is 220-250 ℃; when the low molecular weight polymer is polyethylene terephthalate and the chain extender is 1, 3-phenylene-bis (2-oxazoline), the temperature of the heating treatment is 270-290 ℃; when the low molecular weight polymer is polyphenylene sulfide and the chain extender is diphenylmethane diisocyanate, the temperature of the heating treatment is 280-300 ℃.

In some embodiments, in the step S24, the CNC machining process may include: (1) milling burrs with redundant thickness on the bottom wall and the side wall of the rough blank by CNC; (2) a step structure is formed on the outer wall of the arc corner between the side wall and the bottom wall in an inward CNC milling mode, and C-angle edges are formed on the step structure close to the bottom wall and the side wall respectively; (3) c angle edges are milled for CNC high gloss of the step structure. The forming of the structural part is completed by combining the forming treatment and the CNC machining, the process is stable, the machining precision is high, the production efficiency is high, the machining time is short, and the production cost is low.

In some embodiments, in step S25, the outer surface of the blank may be polished mechanically, chemically, electrochemically, ultrasonically, or the like. So as to reduce the roughness of the surface of the blank and obtain the outer surface of the blank with a bright and flat surface. Wherein, the chemical polishing mode is to regularly dissolve the outer surface of the blank body to achieve smoothness and flatness. The electrochemical polishing mode is that the outer surface of the blank is used as an anode, insoluble metal is used as a cathode, the two electrodes are immersed into an electrolytic tank at the same time, and direct current is conducted to generate selective anode solution, so that the brightness of the outer surface of the blank is increased. The mechanical polishing mode is that the outer surface of the blank body is cut to make the outer surface of the blank body plastically deform and remove the polished convex part to obtain a smooth surface. The ultrasonic polishing mode is that the blank is put into the abrasive suspension and put into an ultrasonic field together, and the abrasive is ground and polished on the surface of the workpiece under the oscillation action of the ultrasonic wave.

In some embodiments, before polishing the outer surface of the blank, the outer surface of the blank may be polished, and then the polished outer surface of the blank may be polished, so that the polishing effect is better, and the outer surface of the blank is smoother. Here, it should be noted that the grinding process is understood as a rough process before the polishing process. Namely, the outer surface of the blank body can be subjected to primary rough grinding and then to primary fine grinding to finish the polishing treatment.

After the polishing treatment of the step S25, the roughness Ra of the outer surface of the blank is 0.02-0.08, the ceramic texture with high glossiness can be realized, and the surface hardness of the polished blank is more than 3H.

In step S26, the fingerprint-resistant coating may be made of an oleophobic coating that makes it difficult for fingerprints to adhere to the terminal surface, so as to reduce the visibility of fingerprints, where the oleophobic coating may be silicone or fluorine compounds, such as perfluoropolyether and polydimethylsiloxane.

The structural member may be prepared as a 2D structure, a 2.5D structure, or a 3D structure as needed, and is not limited herein.

In one aspect of the present application, a structural member is provided, the structural member being made by the method of making in the above embodiments.

In one aspect of the present application, a structural member is presented, the structural member comprising: a blank body and a fingerprint resistant coating formed on the outer surface of the blank body.

And the blank is prepared by performing molding treatment, warm isostatic pressing and heating treatment on the polymer-based composite material, wherein the polymer-based composite material is the polymer-based composite material in the embodiment or the binder prepared by the preparation method in the embodiment.

In some embodiments, the thickness of the fingerprint-resistant coating is 5-20 nm, the water contact angle of the fingerprint-resistant coating is more than 105 degrees, and the material of the fingerprint-resistant coating is a perfluoropolyether compound.

The polymer matrix composite of the present application comprises: the composite material comprises ceramic powder, a coupling agent, a low molecular weight polymer and a chain extender, wherein the low molecular weight polymer has the characteristics of low density, low hardness, low melting point, good fluidity and the like, so that the composite material has low density, can be applied to electronic equipment requiring light weight, can reduce the subsequent processing difficulty, and is easy to prepare complex and various three-dimensional structural parts. Meanwhile, due to the addition of the chain extender, the chain extension increasing reaction of the low molecular weight polymer can be promoted under certain conditions, so that the high molecular weight polymer of a three-dimensional network is formed, the ceramic texture of the structural member is realized, the integral toughness of the structural member can be improved, and the impact strength of the structural member is high. Compared with the prior art, the problems of poor fluidity, difficulty in injection molding and the like caused by too high molecular weight and too high viscosity of the high molecular polymer when the high molecular polymer and the filler are directly blended and injected are solved, and compared with a pure ceramic shell, the structural member prepared from the polymer-based composite material has the advantages of light weight, low cost, adaptability to a complex three-dimensional structure, good dielectric property and the like.

The following examples describe various features and advantages provided by the present application and are in no way intended to limit the present application and the appended claims.

The structural member was prepared according to the conditions listed in table 1 below.

TABLE 1

The structural members prepared under the conditions listed in examples 1-2 and comparative examples 1-2, wherein the high molecular weight polyphenylene sulfide has a molecular weight of up to 10⁴～10⁶. The pencil hardness was measured according to GB/T6739-: taking a flat sample with the volume of 150mm multiplied by 73mm multiplied by 0.8mm, supporting the flat sample on a jig (four sides are respectively provided with 3mm supports, the middle part is suspended), using a 32g stainless steel ball to freely fall from a certain height to the surface of the sample to be measured, wherein the four corners and the center of the sample are divided into five points, and each point is measured for 5 times until the sample is broken. The results of the experiment are shown in table 2.

TABLE 2

As can be seen from table 2, when the mass percentage content of the ceramic powder Al2O3 is reduced to 80% in example 1, the impact resistance can be improved while maintaining the pencil hardness thereof, as compared with comparative example 1; example 2 improved the ceramic powder Al compared with comparative example 2₂O₃When the mass percent of the low molecular polymer is 90%, the pencil hardness can be improved, the impact resistance can be improved, and meanwhile, the injection molding process can be still carried out due to the small molecular weight of the low molecular polymer in the embodiment 2, so that a normal and complete sample wafer can be prepared.

The structural members were prepared according to the conditions listed in table 3 below. Taking the structural part prepared under the conditions listed in example 3 and comparative example 3, measuring the hardness of the pencil according to the GB/T6739-: taking a flat sample with the volume of 150 x 73 x 0.8mm, supporting the flat sample on a jig (four sides are respectively provided with 3mm supports, the middle part is suspended), using a 32g stainless steel ball to freely fall from a certain height to the surface of the sample to be measured, wherein the four corners and the center of the sample are divided into five points, and each point is measured for 5 times until the sample is broken. The results of the experiment are shown in table 3.

TABLE 3

As can be seen from table 3, the addition of the chain extender in example 3 can promote the chain extension reaction of the low molecular weight polymer under certain conditions, so as to form a high molecular weight polymer with a three-dimensional network, thereby improving the overall toughness of the structural member while achieving the ceramic texture of the structural member, and increasing the impact strength of the structural member. In contrast, comparative example 3, in which no chain extender was added, had significantly weaker impact strength than the sample of example 3.

In one aspect of the present application, please refer to fig. 6, which proposes an electronic device 100, wherein the electronic device 100 may be any device with communication and storage functions. For example: the system comprises intelligent equipment with a network function, such as a tablet Computer, a mobile phone, an electronic reader, a remote controller, a Personal Computer (PC), a notebook Computer, vehicle-mounted equipment, a network television, wearable equipment and the like. The electronic device 100 comprises structural members 10, 20. Further, the structural members 10 and 20 are at least one of a battery rear cover, a middle frame, an integrated casing, a volume key and a power key. The structural members 10, 20 are the structural members described in the previous embodiments.

Thus, the electronic device has all the features and advantages of the structural member described above, which are not described in detail herein. Generally, the electronic equipment has good ceramic texture and hand feeling and good appearance effect.

In the description of the present application, the terms "upper", "lower", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present application but do not require that the present application must be constructed and operated in a specific orientation, and thus, cannot be construed as limiting the present application.

Various examples and features of different examples described in this specification can be combined and combined by one skilled in the art without contradiction. In addition, it should be noted that the terms "first" and "second" in this specification are used for descriptive purposes only and are used for visually distinguishing the first region from the second region, as well as the first coating layer from the second coating layer, and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated.

Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.