A heat-conducting wave-absorbing material composition and a preparation method of the heat-conducting wave-absorbing material

Abstract

The application discloses a heat-conducting wave-absorbing material composition, which comprises component A and component B, wherein the component A comprises the following components in parts by mass: 3.5-5 parts of silicone oil, 30-50 parts of graphene-modified spherical silicon carbide, 40-50 parts of heat-conducting filler and 0.02-0.03 parts of catalyst; and the component B comprises the following components in parts by mass: 3.5-5 parts of silicone oil, 30-50 parts of graphene-modified spherical silicon carbide, 40-50 parts of heat-conducting filler and 0.01-0.02 parts of inhibitor. The heat-conducting wave-absorbing material composition has super-high heat-conducting performance, and can effectively inhibit electromagnetic problems in the frequency range of 0.1-8 GHz in communication equipment; after the graphene-modified silicon carbide is applied to products, the dielectric loss can be obviously improved, and the proportion of the magnetic absorbent with poor heat conduction and the improvement of the heat-conducting performance can be reduced in product design.

Description

Technical Field

[0001] This application relates to the field of materials technology, and in particular to a thermally conductive and microwave-absorbing material composition and a method for preparing the thermally conductive and microwave-absorbing material. Background Technology

[0002] Thermally conductive and microwave-absorbing materials are materials that possess both thermal conductivity and microwave absorption capabilities. They can absorb electromagnetic waves while conducting heat, and have broad application prospects. These materials play an important role in fields such as electronic communications, aerospace, and medical devices, and have therefore received widespread attention.

[0003] Most of the thermally conductive and microwave absorbing materials provided in the prior art have low thermal conductivity. US20230320049A1 provides a thermally conductive and microwave absorbing material composed of silicon carbide, magnetic absorber, alumina, and polymer substrate. The thermal conductivity of the provided thermally conductive and microwave absorbing material is 2~4 W / (m·K), which is low thermal conductivity.

[0004] CN117844250A provides a thermally conductive microwave absorbing material. This technology uses thermally conductive microwave absorbing powder with a carbon-based material core and a silicon carbide shell, filled into an organic silicone to obtain a thermally conductive microwave absorbing material. The carbon-based material is one or more of graphite, graphite oxide, graphene, carbon nanotubes, or carbon fibers. According to its embodiments, the thermally conductive microwave absorbing material provided by this technology has a thermal conductivity of 3.5~5.7 W / (m·K), which has good microwave absorption performance, but low thermal conductivity.

[0005] Therefore, providing a thermally conductive and microwave-absorbing material with a simple preparation method and ultra-high thermal conductivity (≥10 W / (m·K)) is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, this application provides a thermally conductive and microwave absorbing material composition with ultra-high thermal conductivity (≥10 W / (m·K)), and the raw materials are simple to prepare and have a low specific surface area, which facilitates the filling of the material.

[0007] This application provides a thermally conductive and microwave absorbing material composition, comprising component A and component B. Component A comprises, by weight parts: 3.5 to 5 parts silicone oil, 30 to 50 parts graphene-modified spherical silicon carbide, 40 to 50 parts thermally conductive filler, and 0.02 to 0.03 parts catalyst; component B comprises, by weight parts: 3.5 to 5 parts silicone oil, 30 to 50 parts graphene-modified spherical silicon carbide, 40 to 50 parts thermally conductive filler, and 0.01 to 0.02 parts inhibitor.

[0008] This application uses component A and component B as raw materials to prepare a thermally conductive and microwave absorbing material composition. Component A, by mass parts, comprises: 3.5 to 5 parts silicone oil, 30 to 50 parts graphene-modified spherical silicon carbide, 40 to 50 parts thermally conductive filler, and 0.02 to 0.03 parts catalyst; component B, by mass parts, comprises: 3.5 to 5 parts silicone oil, 30 to 50 parts graphene-modified spherical silicon carbide, 40 to 50 parts thermally conductive filler, and 0.01 to 0.02 parts inhibitor. This application modifies micron-sized spherical silicon carbide with graphene, utilizing the thermal conductivity of both silicon carbide and graphene, while simultaneously improving the dielectric loss of the product to reduce the amount of magnetic absorbers with poor thermal conductivity, achieving both excellent microwave absorption performance and ultra-high thermal conductivity. The thermally conductive and microwave-absorbing material composition described in this application possesses ultra-high thermal conductivity of 10~12 W / (m·K), effectively solving electromagnetic problems in the 0.1~8 GHz frequency band while providing efficient heat transfer for equipment. Through optimized selection of components, this application can meet microwave absorption requirements and improve thermal conductivity while reducing the use of iron-based absorbers.

[0009] The thermally conductive and microwave-absorbing material composition described in this application includes silicone oil. The silicone oil in components A and B includes, but is not limited to, vinyl silicone oil and / or hydrogen-containing silicone oil. This application does not have specific requirements regarding the selection of silicone oil. The mass fractions of silicone oil in components A and B are each independently 3.5 to 5 parts, and can be 3.5, 3.7, 3.9, 4, 4.2, 4.4, 4.5, 4.6, 4.8, or 5 parts. In some specific implementations, the silicone oil in component B includes vinyl silicone oil and hydrogen-containing silicone oil, comprising, by mass fraction: 4 to 4.15 parts vinyl silicone oil and 0.3 to 0.4 parts hydrogen-containing silicone oil, preferably 4.1 to 4.12 parts vinyl silicone oil and 0.38 to 0.4 parts hydrogen-containing silicone oil.

[0010] The thermally conductive and microwave-absorbing material composition described in this application comprises graphene-modified spherical silicon carbide. In some specific implementations, the specific surface area of ​​the graphene-modified spherical silicon carbide in component A and component B is each independently 0.2 m². 2 / g to 1 m 2 / g; the particle size of the graphene-modified spherical silicon carbide in components A and B is independently from 10 μm to 100 μm, preferably from 20 μm to 70 μm. In some specific implementations, the spherical silicon carbide in the graphene-modified spherical silicon carbide in components A and B independently includes large-particle-size spherical silicon carbide and / or small-particle-size spherical silicon carbide, wherein the particle size of the large-particle-size spherical silicon carbide is 70 μm and the particle size of the small-particle-size spherical silicon carbide is 20 μm. In some specific implementations, the preparation method of the graphene-modified spherical silicon carbide in components A and B independently includes: mixing spherical silicon carbide with graphene, and ball milling to obtain graphene-modified spherical silicon carbide. In some specific implementations, the spherical silicon carbide is obtained by spray granulation of silicon carbide; the mass ratio of graphene to spherical silicon carbide is independently (0.05-1):(95-100), preferably 0.1:100; the ball milling time is 4h to 10h, which can be 4h, 5h, 6h, 7h, 8h, 9h, or 10h. In some specific implementations, the thickness of the graphene in the graphene-modified spherical silicon carbide of component A and component B is independently 1 nm to 4 nm; the sheet diameter of the graphene is independently 1 μm to 5 μm; and the specific surface area of ​​the graphene is independently 50 m². 2 / g to 85m 2 / g. This application uses pre-prepared graphene, whose specifications (thickness, sheet diameter, specific surface area, etc.) are more controllable, which is more conducive to material dispersion. When mixed with silicon carbide for modification, it can be completed by ball milling with low energy (speed ≤100RPM, duration 4~10h), which improves efficiency and reduces damage to the surface of spherical silicon carbide during ball milling. Combined with micron-sized spherical silicon carbide, the obtained graphene-modified silicon carbide powder has a lower specific surface area, which is more conducive to material filling and to achieving ultra-high thermal conductivity. Both silicon carbide and graphene are high thermal conductivity materials and also have wave absorption properties. In particular, after modifying silicon carbide with graphene, its application in products can significantly improve dielectric loss, which is conducive to reducing the proportion of magnetic absorbers with poor thermal conductivity in product design and improving the thermal conductivity of the product. After modification with micron-sized spherical silicon carbide, the specific surface area is even lower, which is not only easier to fill, but also more conducive to improving thermal conductivity.

[0011] The thermally conductive and microwave-absorbing material composition described in this application includes thermally conductive fillers. The thermally conductive fillers in component A and component B are each independently including, but not limited to, one or more of alumina, aluminum nitride, boron nitride, or zinc oxide. This application does not have specific requirements for the selection of thermally conductive fillers. In some specific implementations, the particle size of the thermally conductive fillers in component A and component B is each independently from 1 μm to 96 μm. The mass fractions of the thermally conductive fillers in component A and component B are each independently from 40 parts to 50 parts, and can be 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, or 50 parts.

[0012] The thermally conductive and microwave-absorbing material composition described in this application includes a catalyst. The catalyst in component A includes, but is not limited to, a platinum catalyst; this application does not have specific requirements for the selection of the catalyst. In some specific implementations, the platinum content in the platinum catalyst is 0.05%. The mass fraction of the catalyst in component A is 0.02 to 0.03 parts, and can be 0.02 parts, 0.022 parts, 0.024 parts, 0.026 parts, 0.028 parts, or 0.03 parts.

[0013] The thermally conductive and microwave-absorbing material composition described in this application includes an inhibitor. The inhibitor in component B includes, but is not limited to, one or more of methyltris(1,1-dimethyl-1-ethynylmethoxy)silane, vinyltris(1,1-dimethyl-1-ethynylmethoxy)silane, phenyltris(1,1-dimethyl-1-ethynylmethoxy)silane, 3-methyl-1-butyn-3-ol, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, N,N,N',N'-tetraallylterephthalamide, or monoallyl maleate. This application does not have specific requirements for the selection of the inhibitor. The mass fraction of the inhibitor in component B is from 0.01 to 0.02 parts, and can be 0.01 parts, 0.012 parts, 0.014 parts, 0.015 parts, 0.016 parts, 0.018 parts, or 0.02 parts.

[0014] The thermally conductive and microwave-absorbing material composition described in this application further includes an iron-based absorber. In some specific implementations, the iron-based absorber includes, but is not limited to, iron-based amorphous alloy powder. This application does not have special requirements for the selection of the iron-based absorber; the particle size of the iron-based absorber is 1 μm to 10 μm. The mass fraction of the iron-based absorber is 9 to 18 parts, and can be 9, 10, 11, 12, 13, 14, 15, 16, 17, or 18 parts.

[0015] In some specific implementations, the volume ratio of component A to component B is (0.8~1.2):1, preferably 1:1.

[0016] This application also provides a method for preparing a thermally conductive and microwave-absorbing material, including:

[0017] Component A is obtained by mixing graphene-modified spherical silicon carbide, thermally conductive filler, silicone oil, and catalyst.

[0018] Component B is obtained by mixing graphene-modified spherical silicon carbide, thermally conductive filler, silicone oil, and inhibitor.

[0019] Component A and component B are mixed and cured to obtain a thermally conductive and microwave-absorbing material.

[0020] This application first prepares graphene-modified spherical silicon carbide. In some specific implementations, silicon carbide is spray-granulated to obtain spherical silicon carbide; the spherical silicon carbide is then mixed with graphene and ball-milled to obtain graphene-modified spherical silicon carbide. In some specific implementations, the mass ratio of graphene to spherical silicon carbide is (0.05-1):(95-100); the ball-milling time is 4 to 10 hours. Spheroidization can improve the filling effect of the powder, which is beneficial for high filling in product manufacturing. Simultaneously, the preparation method uses graphene with a relatively low specific surface area and requires a low dosage, resulting in modified spherical silicon carbide with good filling performance, which is beneficial for achieving ultra-high thermal conductivity.

[0021] This application then mixes graphene-modified spherical silicon carbide, thermally conductive filler, silicone oil, and catalyst to obtain component A. In some specific implementations, the mixing is carried out under stirring; the mixing time is 20 min to 30 min, preferably 30 min; the mixing is carried out under vacuum conditions; the vacuum degree is 4 Pa ​​to 10 Pa. In some specific implementations, the silicone oil includes, but is not limited to, vinyl silicone oil and / or hydrogen-containing silicone oil; this application does not have special requirements for the selection of silicone oil.

[0022] This application then mixes graphene-modified spherical silicon carbide, thermally conductive filler, silicone oil, and inhibitor to obtain component B. In some specific implementations, the mixing is carried out under stirring; the mixing time is 20 min to 30 min, preferably 30 min; the mixing is carried out under vacuum conditions; the vacuum degree is 4 Pa ​​to 10 Pa. In some specific implementations, the silicone oil includes, but is not limited to, vinyl silicone oil and / or hydrogen-containing silicone oil; this application does not have special requirements for the selection of silicone oil.

[0023] This application then mixes component A and component B, and cures them to obtain a thermally conductive and microwave-absorbing material. In some specific implementations, the curing temperature is 120°C to 130°C, preferably 125°C; the curing time is 20 min to 40 min. In some specific implementations, the volume ratio of component A to component B is (0.8~1.2):1, preferably 1:1.

[0024] The thermally conductive and microwave-absorbing material composition provided in this application possesses ultra-high thermal conductivity, with a thermal conductivity coefficient of 10~12 W / (m·K) and a hardness of 65±5 Shore OO after curing. It exhibits highly efficient microwave absorption performance, effectively suppressing electromagnetic problems in the 0.1~8GHz frequency band of communication equipment. Both silicon carbide and graphene are high thermal conductivity materials and also possess microwave absorption properties. In particular, graphene-modified silicon carbide significantly improves dielectric loss when applied to products, thereby reducing the proportion of poorly conductive magnetic absorbers in product design and improving the product's thermal conductivity. The graphene-modified spherical silicon carbide in the raw materials of the thermally conductive and microwave-absorbing material composition has a specific surface area of ​​<1 m². 2 / g has good filling properties, which is beneficial for achieving ultra-high thermal conductivity. Attached Figure Description

[0025] Figure 1 This is a flowchart illustrating the fabrication process of the thermally conductive and microwave-absorbing material provided in this application.

[0026] Figure 2 This is a test effect diagram of the application of the test fixture for the thermally conductive and microwave-absorbing material provided in Embodiment 1 of this application;

[0027] Figure 3 This is a test effect diagram of the application of the test fixture for the thermally conductive and microwave-absorbing material provided in Embodiment 2 of this application;

[0028] Figure 4 This is a test effect diagram of the application of the test fixture for the thermally conductive and microwave-absorbing material provided in Embodiment 3 of this application;

[0029] Figure 5 The image shows the application test effect of the test fixture for the thermally conductive and microwave-absorbing material provided in Comparative Example 1 of this application. Detailed Implementation

[0030] It should be understood that the expression “one or more of…” individually includes each of the objects described after the expression, as well as various different combinations of two or more of the described objects, unless otherwise understood from the context and usage. The expression “and / or” combined with three or more described objects should be understood to have the same meaning, unless otherwise understood from the context.

[0031] The terms “including,” “having,” or “containing,” including the use of their grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unstated elements or steps, unless otherwise specifically stated or understood from the context.

[0032] It should be understood that the order of steps or the sequence of actions is not important as long as this application remains operational. Furthermore, two or more steps or actions can be performed simultaneously.

[0033] The use of any and all instances or exemplary language such as “e.g.” or “including” herein is merely intended to better illustrate the application and does not constitute a limitation on the scope of the application unless the claims are made. No language in this specification should be construed as indicating that any unclaimed element is essential to the practice of this application.

[0034] Furthermore, the numerical ranges and parameters used to define this application are approximate values, and the relevant values ​​in the specific embodiments have been presented as precisely as possible. However, any numerical value inevitably contains standard deviations due to individual test methods. Therefore, unless otherwise explicitly stated, it should be understood that all ranges, quantities, values, and percentages used in this disclosure are modified with the word "approximately." Here, "approximately" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specific value or range.

[0035] This application provides a thermally conductive and microwave absorbing material composition, comprising component A and component B. Component A comprises, by weight parts: 3.5 to 5 parts silicone oil, 30 to 50 parts graphene-modified spherical silicon carbide, 40 to 50 parts thermally conductive filler, and 0.02 to 0.03 parts catalyst; component B comprises, by weight parts: 3.5 to 5 parts silicone oil, 30 to 50 parts graphene-modified spherical silicon carbide, 40 to 50 parts thermally conductive filler, and 0.01 to 0.02 parts inhibitor.

[0036] The thermally conductive and microwave-absorbing material composition provided in this application possesses ultra-high thermal conductivity, with a thermal conductivity coefficient of 10~12 W / (m·K) and a hardness of 65±5 Shore OO after curing. It exhibits highly efficient microwave absorption performance, effectively suppressing electromagnetic problems in the 0.1~8GHz frequency band of communication equipment. Both silicon carbide and graphene are high thermal conductivity materials and also possess microwave absorption properties. In particular, graphene-modified silicon carbide significantly improves dielectric loss when applied to products, thereby reducing the proportion of poorly conductive magnetic absorbers in product design and improving the product's thermal conductivity. The graphene-modified spherical silicon carbide in the raw materials of the thermally conductive and microwave-absorbing material composition has a specific surface area of ​​<1 m². 2 / g has good filling properties, which is beneficial for achieving ultra-high thermal conductivity.

[0037] The present application is further illustrated below with reference to embodiments. The scope of protection of the present application is not limited to the following embodiments.

[0038] Example 1

[0039] This embodiment provides a thermally conductive and microwave-absorbing material composition, comprising component A and component B. Component A, by mass parts, comprises: 4.5 parts vinyl silicone oil, 24.9 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 7.1 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 20 μm, 18 parts iron-based amorphous alloy powder, 36 parts aluminum nitride powder with a particle size (D50) of approximately 96, 9.5 parts zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.025 parts catalyst. The agent; component B, by mass parts, comprises: 4.1 parts vinyl silicone oil, 0.4 parts hydrogen-containing silicone oil, 24.9 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 7.1 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 20 μm, 18 parts iron-based amorphous alloy powder, 36 parts aluminum nitride powder with a particle size (D50) of approximately 96, 9.5 parts zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.02 parts inhibitor; the volume ratio of component A to component B is 1:1.

[0040] Methods for preparing thermally conductive and microwave-absorbing materials include:

[0041] Spherical silicon carbide powder was prepared by spray granulation, and after sieving, spherical silicon carbide powder with a particle size (D50) of approximately 70 μm and spherical silicon carbide powder with a particle size (D50) of approximately 20 μm were obtained. The aforementioned spherical silicon carbide powder was modified by ball milling. During the ball milling process, an ethanol slurry of graphene was added, and the amount of graphene used was 0.1% of the mass of silicon carbide. After ball milling, the powder was dried to obtain graphene-modified spherical silicon carbide.

[0042] 4.5 parts of vinyl silicone oil, 24.9 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 7.1 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 20 μm, 18 parts of iron-based amorphous alloy powder, 36 parts of aluminum nitride powder with a particle size (D50) of approximately 96, 9.5 parts of zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.025 parts of catalyst were mixed and stirred evenly at room temperature. During the stirring process, the vacuum was maintained at ≤10 Pa, and the stirring time was 30 min to obtain component A.

[0043] Component B was prepared by mixing and stirring 4.1 parts of vinyl silicone oil, 0.4 parts of hydrogen-containing silicone oil, 24.9 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 7.1 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 20 μm, 18 parts of iron-based amorphous alloy powder, 36 parts of aluminum nitride powder with a particle size (D50) of approximately 96, 9.5 parts of zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.02 parts of inhibitor at room temperature. The mixture was stirred under a vacuum of ≤10 Pa for 30 min to obtain component B.

[0044] The aforementioned components A and B were mixed in a volume ratio of 1:1 and then cured to obtain a thermally conductive and microwave-absorbing material.

[0045] The preparation process flow chart of the thermally conductive and microwave absorbing material is as follows: Figure 1 As shown.

[0046] Example 2

[0047] This embodiment provides a thermally conductive and microwave-absorbing material composition, comprising component A and component B. Component A, by mass parts, comprises: 4.5 parts vinyl silicone oil, 24.7 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 12.5 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 20 μm, 9.3 parts iron-based amorphous alloy powder, 39 parts aluminum nitride powder with a particle size (D50) of approximately 96, 10 parts alumina powder with a particle size (D50) of approximately 1 μm, and 0.025 parts catalyst. The agent; component B, by mass parts, comprises: 4.1 parts vinyl silicone oil, 0.4 parts hydrogen-containing silicone oil, 24.7 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 12.5 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 20 μm, 9.3 parts iron-based amorphous alloy powder, 39 parts aluminum nitride powder with a particle size (D50) of approximately 96, 10 parts zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.02 parts inhibitor; the volume ratio of component A to component B is 1:1.

[0048] Methods for preparing thermally conductive and microwave-absorbing materials include:

[0049] Spherical silicon carbide powder was prepared by spray granulation and then sieved to obtain spherical silicon carbide powder with particle sizes (D50) of approximately 70 μm and approximately 20 μm. The aforementioned spherical silicon carbide powder was then modified using a ball milling process. During ball milling, an ethanol slurry containing graphene was added, with the amount of graphene being 0.1% of the silicon carbide mass. After ball milling, the powder was dried to obtain graphene-modified spherical silicon carbide.

[0050] 4.5 parts of vinyl silicone oil, 24.7 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 12.5 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 20 μm, 9.3 parts of iron-based amorphous alloy powder, 39 parts of aluminum nitride powder with a particle size (D50) of approximately 96, 10 parts of zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.025 parts of catalyst were mixed and stirred evenly at room temperature. During the stirring process, the vacuum was maintained at ≤10 Pa, and the stirring time was 30 min to obtain component A.

[0051] Component B was prepared by mixing and stirring 4.1 parts of vinyl silicone oil, 0.4 parts of hydrogen-containing silicone oil, 24.7 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 12.5 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 20 μm, 9.3 parts of iron-based amorphous alloy powder, 39 parts of aluminum nitride powder with a particle size (D50) of approximately 96, 10 parts of zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.02 parts of inhibitor at room temperature. The mixture was stirred under a vacuum of ≤10 Pa for 30 min to obtain component B.

[0052] The aforementioned components A and B were mixed in a volume ratio of 1:1 and then cured to obtain a thermally conductive and microwave-absorbing material.

[0053] Example 3

[0054] This embodiment provides a thermally conductive and microwave-absorbing material composition, comprising component A and component B. Component A, by mass parts, comprises: 4.5 parts vinyl silicone oil, 30 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 20 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 45 μm, 31 parts aluminum nitride powder with a particle size (D50) of approximately 96, 9 parts alumina powder with a particle size (D50) of approximately 2.5 μm, 5.5 parts zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.025 parts catalyst. Component B, by mass parts, comprises: 4.12 parts vinyl silicone oil, 0.38 parts hydrogen-containing silicone oil, 30 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 20 parts graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 45 μm, 31 parts aluminum nitride powder with a particle size (D50) of approximately 96, 9 parts alumina powder with a particle size (D50) of approximately 2.5 μm, 5.5 parts zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.02 parts inhibitor; the volume ratio of component A to component B is 1:1.

[0055] Methods for preparing thermally conductive and microwave-absorbing materials include:

[0056] Spherical silicon carbide powder was prepared by spray granulation and then sieved to obtain spherical silicon carbide powder with particle sizes (D50) of approximately 70 μm and 45 μm. The aforementioned spherical silicon carbide powder was then modified using a ball milling process. During ball milling, an ethanol slurry containing graphene was added, with the amount of graphene being 0.1% of the silicon carbide mass. After ball milling, the powder was dried to obtain graphene-modified spherical silicon carbide.

[0057] 4.5 parts of vinyl silicone oil, 30 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 20 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 45 μm, 31 parts of aluminum nitride powder with a particle size (D50) of approximately 96, 9 parts of alumina powder with a particle size (D50) of approximately 2.5 μm, 5.5 parts of zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.025 parts of catalyst were mixed and stirred evenly at room temperature. During the stirring process, the vacuum was maintained at ≤10 Pa, and the stirring time was 30 min to obtain component A.

[0058] Component B was prepared by mixing and stirring 4.12 parts of vinyl silicone oil, 0.38 parts of hydrogen-containing silicone oil, 30 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 70 μm, 20 parts of graphene-modified spherical silicon carbide powder with a particle size (D50) of approximately 45 μm, 31 parts of aluminum nitride powder with a particle size (D50) of approximately 96, 9 parts of alumina powder with a particle size (D50) of approximately 2.5 μm, 5.5 parts of zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.02 parts of inhibitor at room temperature. The mixture was stirred under a vacuum of ≤10 Pa for 30 min to obtain component B.

[0059] The aforementioned components A and B were mixed in a volume ratio of 1:1 and then cured to obtain a thermally conductive and microwave-absorbing material.

[0060] Comparative Example 1

[0061] This comparative example provides a thermally conductive and microwave-absorbing material composition, which differs from Example 1 in that the graphene-modified spherical silicon carbide is replaced with graphene-modified micron-sized amorphous silicon carbide.

[0062] The difference between the preparation method of graphene-modified micron-sized amorphous silicon carbide and the preparation method of graphene-modified spherical silicon carbide powder in Example 1 is that the spherical silicon carbide with a particle size (D50) of about 70 μm and about 45 μm is replaced with amorphous silicon carbide with a particle size (D50) of about 70 μm and about 45 μm.

[0063] 4.5 parts of vinyl silicone oil, 20.3 parts and 6.7 parts of the aforementioned modified amorphous silicon carbide powder with particle sizes (D50) of approximately 70 μm and 45 μm, respectively, 26 parts of iron-based amorphous alloy powder, 34 parts of aluminum nitride powder with a particle size (D50) of approximately 96 μm, 8.5 parts of zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.025 parts of catalyst were mixed and stirred evenly at room temperature. During the stirring process, the vacuum was maintained at ≤10 Pa, and the stirring time was 30 min to obtain component A.

[0064] 4.1 parts of vinyl silicone oil, 0.4 parts of hydrogen-containing silicone oil, 20.3 parts and 6.7 parts of the aforementioned modified amorphous silicon carbide powder with particle sizes (D50) of approximately 70 μm and approximately 20 μm, respectively, 26 parts of iron-based amorphous alloy powder, 34 parts of aluminum nitride powder with a particle size (D50) of approximately 96, 8.5 parts of zinc oxide powder with a particle size (D50) of approximately 1 μm, and 0.02 parts of inhibitor were mixed and stirred evenly at room temperature. During the stirring process, the vacuum was maintained at ≤10 Pa, and the stirring time was 30 min to obtain component B.

[0065] The aforementioned components A and B were mixed in a volume ratio of 1:1 and then cured to obtain a thermally conductive and microwave-absorbing material.

[0066] The thermally conductive and microwave-absorbing material provided in this application was coated onto a test fixture (simulating a communication device) with a thickness of approximately 0.7 mm. After assembly, S21 was tested at 0.1~8 GHz. The same test was performed without the thermally conductive and microwave-absorbing material as a blank control. The application test effect diagrams of Examples 1 to 3 are shown below. Figure 2 , Figure 3 , Figure 4 As shown in the figure, the application test results of Comparative Example 1 are as follows. Figure 5 As shown in the figure; the results show that the thermally conductive and microwave absorbing material provided in this application can effectively solve the electromagnetic problems in the 0.1~8 GHz frequency band of the equipment while providing ultra-high thermal conductivity (thermal conductivity ≥10 W / (m·K)) and with a relatively thin application thickness of 0.7 mm.

[0067] The thermally conductive and microwave-absorbing materials provided in Examples 1-3 and Comparative Example 1 were subjected to performance tests, and the test methods are as follows:

[0068] Thermal conductivity: Tested according to the method standard ISO 22007-2:2008;

[0069] Hardness: Shore OO hardness tester, reading in 3 seconds.

[0070] The test results are shown in Table 1.

[0071] Table 1

[0072]

[0073] As shown in Table 1, the thermal conductivity of the thermally conductive and microwave-absorbing material used in this application can reach more than 10 W / (m·K), and the hardness is between 63 and 65. In Example 3, no iron-based absorber was added, and the thermal conductivity was significantly improved to 12.057 W / (m·K) while meeting the microwave absorption performance requirements. In contrast, the thermal conductivity of Comparative Example 1 was <10 W / (m·K) while meeting the microwave absorption performance requirements.

[0074] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and application concept of this application, should be included within the scope of protection of this application.

Claims

1. A thermally and wave-absorbing material composition, characterized by comprising: The component A comprises, in parts by mass: 3.5 to 5 parts of silicone oil, 30 to 50 parts of graphene-modified spherical silicon carbide, 40 to 50 parts of thermally conductive filler, and 0.02 to 0.03 parts of catalyst; and the component B comprises, in parts by mass: 3.5 to 5 parts of silicone oil, 30 to 50 parts of graphene-modified spherical silicon carbide, 40 to 50 parts of thermally conductive filler, and 0.01 to 0.02 parts of inhibitor. The mass ratio of graphene to spherical silicon carbide in the graphene-modified spherical silicon carbide in the component A and the component B is independently (0.05-1):(95-100). The specific surface area of the graphene-modified spherical silicon carbide in the component A, component B is each independently 0.2 m 2 / g to 1 m 2 / g; the thickness of the graphene in the graphene-modified spherical silicon carbide in Component A, Component B is each independently 1 nm to 4 nm; the flake diameter of the graphene is each independently 1 pm to 5 pm; the specific surface area of the graphene is each independently 50 m 2 / g to 85 m 2 / g; The preparation method of the graphene-modified spherical silicon carbide comprises: mixing spherical silicon carbide and graphene, and performing ball milling to obtain graphene-modified spherical silicon carbide.

2. The thermally and wave-absorptively conductive material composition according to claim 1, characterized by The particle size of the spherical silicon carbide in the graphene-modified spherical silicon carbide in the component A and the component B is independently 10 μm to 100 μm.

3. The thermally and wave-absorptively conductive material composition according to claim 1, wherein The spherical silicon carbide in the graphene-modified spherical silicon carbide in the component A and the component B independently comprises large-particle-size spherical silicon carbide and / or small-particle-size spherical silicon carbide; the particle size of the large-particle-size spherical silicon carbide is 70 μm, and the particle size of the small-particle-size spherical silicon carbide is 20 μm.

4. The thermally and wave-absorptively conductive material composition according to claim 1, wherein The silicone oil in the component A and the component B independently comprises vinyl silicone oil and / or hydrogen-containing silicone oil; the thermally conductive filler in the component A and the component B independently comprises one or more of aluminum oxide, aluminum nitride, boron nitride, or zinc oxide; the particle size of the thermally conductive filler in the component A and the component B is independently 1 μm to 96 μm; and the volume ratio of the component A to the component B is (0.8-1.2):

1.

5. The thermally and wave-absorptively conductive material composition according to claim 1, wherein The catalyst in the component A comprises platinum-gold catalyst; and the inhibitor in the component B comprises one or more of methyltris(1,1-dimethyl-1-ethynylmethoxy)silane, vinyltris(1,1-dimethyl-1-ethynylmethoxy)silane, phenyltris(1,1-dimethyl-1-ethynylmethoxy)silane, 3-methyl-1-butyne-3-ol, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, N,N,N',N'-tetraallylterephthalamide, or maleic acid monoallyl ester.

6. The thermally and wave-absorptively conductive material composition according to claim 1, wherein The component A and the component B independently further comprise, in parts by mass, 9 to 18 parts of iron-based absorber; the iron-based absorber comprises iron-based amorphous alloy powder; and the particle size of the iron-based absorber is 1 μm to 10 μm.

7. A method of producing a thermally and wave-absorbing material as claimed in any one of claims 1-6, characterized in that, The component A and the component B independently further comprise, in parts by mass, 9 to 18 parts of iron-based absorber; the iron-based absorber comprises iron-based amorphous alloy powder; and the particle size of the iron-based absorber is 1 μm to 10 μm. The component A and the component B are mixed, and cured to obtain the thermally conductive wave-absorbing material. The preparation method of the graphene-modified spherical silicon carbide independently comprises: mixing spherical silicon carbide and graphene, and performing ball milling to obtain graphene-modified spherical silicon carbide. ​ 8. The preparation method according to claim 7, characterized in that, ​

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