CN117767019A - Heat-conducting wave-absorbing material, and preparation method and application thereof - Google Patents

Abstract

The application relates to a heat-conducting wave-absorbing material, a preparation method and application thereof, and belongs to the technical field of heat-conducting wave-absorbing materials. A heat conduction wave-absorbing material comprises a first gasket and a first copper ring which is horizontally arranged on the first gasket; wherein, the first gasket comprises the following components in percentage by mass: 30-40% of wave absorber, 50-60% of heat conducting powder, 5-12% of silicone oil carrier, 0.01-0.03% of inhibitor and 0.1-0.4% of catalyst. In this application, be provided with first copper ring on first gasket, under the condition that has the electromagnetic wave to shine, can produce the induced magnetic field of an interact between first copper ring and the outside electromagnetic field, this induced magnetic field and outside electromagnetic field interact have further strengthened the absorption and the conversion to the electromagnetic wave, therefore the wave absorbing performance of wave absorbing material can further be strengthened to the addition of first copper ring.

Description

Heat-conducting wave-absorbing material, and preparation method and application thereof

Technical Field

The application relates to the technical field of heat-conducting wave-absorbing materials, and in particular relates to a heat-conducting wave-absorbing material, a preparation method and application thereof.

Background

In the problems of electromagnetic wave interference, planar standing waves and the like, the performance of a common wave absorbing material is generally affected by the incident angle of electromagnetic waves, so that the wave absorbing capacity gradually changes under different incident angles. Although the reflection loss performance is basically consistent at the 0 degree horizontal incidence and the 90 degree vertical incidence, the performance of the traditional wave absorbing material in the aspect of absorbing the horizontal incidence electromagnetic wave still needs to be improved for the electromagnetic interference problem of the 0 degree incidence and the solution of the plane standing wave.

Moreover, conventional wave absorbing materials still have the problem of limited absorption range, thereby limiting the application of the materials in a wider frequency band. Therefore, for ultra-wideband absorption, improving compatibility of materials and providing applicability of materials in complex environments remains a problem to be solved.

Disclosure of Invention

In view of the shortcomings of the prior art, the purpose of the embodiments of the present application includes providing a heat-conducting wave-absorbing material, and a preparation method and application thereof, so as to enhance the absorption efficiency of electromagnetic waves incident at 0 ° and provide a wider absorption range, and enhance the applicability of the wave-absorbing material to various environments.

In a first aspect, embodiments of the present application provide a thermally conductive wave-absorbing material, including a first gasket and a first copper ring laid flat on the first gasket; wherein, the first gasket comprises the following components in percentage by mass: 30-40% of wave absorber, 50-60% of heat conducting powder, 5-12% of silicone oil carrier, 0.01-0.03% of inhibitor and 0.1-0.4% of catalyst.

In this application, be provided with first copper ring on first gasket, under the condition that has the electromagnetic wave to shine, can produce the induced magnetic field of an interact between first copper ring and the outside electromagnetic field, this induced magnetic field and outside electromagnetic field interact have further strengthened the absorption and the conversion to the electromagnetic wave, therefore the wave absorbing performance of wave absorbing material can further be strengthened to the addition of first copper ring. Moreover, by adding the first copper ring to the wave-absorbing material, which has a resonance phenomenon in an environment with electromagnetic waves, the first copper ring serves as a resonance ring, and the first copper ring can also improve the impedance matching of the wave-absorbing material to enhance the wave-absorbing performance. When the wave-absorbing material interacts with the electromagnetic field, the wave-absorbing material is more efficient in receiving and converting electromagnetic energy if its impedance matches that of the external electromagnetic field. Therefore, the addition of the first copper ring can change the impedance property of the wave-absorbing material, so that the impedance of the wave-absorbing material is more matched with the impedance of an external electromagnetic field, and the wave-absorbing performance of the wave-absorbing material can be improved. That is, the first copper ring is added into the wave-absorbing material to enhance the wave-absorbing performance, and the wave-absorbing performance is mainly realized through electromagnetic induction, electromagnetic conversion, impedance matching and other mechanisms. These mechanisms work together to enable the wave-absorbing material to more effectively absorb and convert electromagnetic energy.

In some embodiments of the present application, the first copper ring has a thickness of 80-120 μm.

In some embodiments of the present application, the thermally conductive wave-absorbing material further includes a second copper ring laid flat on the first pad, the second copper ring being located within the first copper ring, the second copper ring having a diameter of 55-70% of the width of the first pad, the first copper ring having a diameter of 85-95% of the width of the first pad. The double copper ring acts more on itself with resonance characteristics than the single copper ring. When electromagnetic waves are incident on a single copper ring, induced current is generated in the copper ring, and an eddy current effect is formed. At resonance, the impedance of the single copper ring changes, thereby affecting the propagation and absorption of electromagnetic waves. The double copper rings can be regarded as being formed by connecting two single copper rings, and when electromagnetic waves are incident on the double copper rings, a coupling effect is generated between the two single copper rings, so that a complex resonance system is formed. The system has a higher impedance variation range and can absorb and attenuate electromagnetic waves more effectively.

When the diameter of the second copper ring is 55-70% of the width of the first gasket, and the diameter of the first copper ring is 85-95% of the width of the first gasket, the coverage of the application area of the wave-absorbing material can be completed.

In some embodiments of the present application, the thermally conductive wave-absorbing material further includes a second spacer, the second spacer and the first spacer sandwiching the first copper ring and the second copper ring.

In some embodiments of the present application, the wave absorber comprises at least one of carbonyl iron powder, silicon carbide, acetylene black, and ferrite. The combined use of these wave-absorbing materials can optimize the wave-absorbing properties of the wave-absorbing materials because they exhibit complementary wave-absorbing mechanisms in different frequency ranges. By adjusting the content and proportion of each component, the effective absorption of a specific frequency band can be realized. In addition, the combination of these wave-absorbing materials can also improve the applicability of the materials, so that the materials can play a role in wider electromagnetic environments.

In some embodiments of the present application, the carbonyl iron powder has a particle size of 2-50 μm. The particle size of the carbonyl iron powder is limited to be in the range of 2-50 mu m, so that the carbonyl iron powder can show better wave absorbing effect on electromagnetic waves with different frequencies; it may also help to improve the dispersibility of the material, i.e. the particles are uniformly distributed in the matrix. The uniformly dispersed particles can better interact with the matrix, and the electromagnetic wave absorption is improved. In addition, the particle size range helps to stabilize the properties of the material.

In some embodiments of the present application, the wave absorber is a mixture of carbonyl iron powder, silicon carbide, acetylene black and ferrite with different particle sizes, and the wave absorber comprises the following components in percentage by mass: 25-30% of 2.7 mu m carbonyl iron powder, 6-10% of 10 mu m carbonyl iron powder, 12-16% of 50 mu m carbonyl iron powder, 3-8% of silicon carbide, 1-5% of acetylene black and 40-44% of ferrite; or the wave absorber is a mixture of carbonyl iron powder, silicon carbide and acetylene black with different particle sizes, and comprises the following components in percentage by mass: 68-73% of 2.7 mu m carbonyl iron powder, 6-10% of 10 mu m carbonyl iron powder, 12-16% of 50 mu m carbonyl iron powder, 3-8% of silicon carbide and 1-5% of acetylene black; or the wave absorber is a mixture of carbonyl iron powder, silicon carbide and ferrite with different particle sizes, and comprises the following components in percentage by mass: 25-30% of 2.7 mu m carbonyl iron powder, 6-10% of 10 mu m carbonyl iron powder, 12-16% of 50 mu m carbonyl iron powder, 3-8% of silicon carbide and 41-44% of ferrite; or the wave absorber is a mixture of carbonyl iron powder with different particle sizes, and comprises the following components in percentage by mass: 68-73% of 2.7 mu m carbonyl iron powder, 12-16% of 10 mu m carbonyl iron powder and 12-16% of 50 mu m carbonyl iron powder.

In some embodiments of the present application, the thermally conductive powder includes at least one of an aluminum oxide powder, an aluminum nitride powder, a zinc oxide powder, a graphene powder, a boron nitride powder, and a diamond powder. The effective heat conducting performance in a wide frequency range can be realized by selecting various heat conducting powder, and the heat conducting effect of the whole material is improved. The wave absorbing performance of the wave absorbing material under different frequencies can be optimized, and a wider application range is provided.

In some embodiments of the present application, the alumina powder has a particle size of 0.5 to 120 μm. The alumina powder with the grain diameter of 0.5-120 mu m can better improve the heat conduction performance and electromagnetic wave absorption performance of the heat conduction wave-absorbing material.

In some embodiments of the present application, the heat conductive powder includes, in mass percent: 1-5% of 0.5 mu m alumina powder, 35-50% of 75 mu m alumina powder, 5-15% of zinc oxide powder, 1-5% of graphene powder and 35-50% of aluminum nitride powder; or, the heat conducting powder comprises the following components in percentage by mass: 1-5% of 0.5 mu m alumina powder, 38-62% of 75 mu m alumina powder, 8-20% of zinc oxide powder, 38-62% of aluminum nitride powder and 8-20% of boron nitride powder; or, the heat conducting powder comprises the following components in percentage by mass: 1-5% of 0.5 mu m alumina powder, 35-50% of 75 mu m alumina powder, 35-50% of aluminum nitride powder, 8-15% of boron nitride powder and 1-5% of graphene powder; or, the heat conducting powder comprises the following components in percentage by mass: 45-60% of 75 mu m aluminum oxide powder, 5-15% of zinc oxide powder, 1-7% of graphene powder and 30-45% of aluminum nitride powder.

In some embodiments of the present application, the silicone oil carrier comprises a vinyl silicone oil and/or an H-containing silicone oil. The vinyl silicone oil and the H-containing silicone oil have good heat conduction performance, are favorable for improving the overall heat conduction of the heat conduction wave-absorbing material, and enable the material to conduct heat efficiently in the electromagnetic wave absorption process.

In some embodiments of the present application, the inhibitor includes ethynyl cyclohexanol and/or methylbutynol.

In some embodiments of the present application, the catalyst comprises a platinum catalyst. Platinum is a high-efficiency catalyst and has good catalytic activity. It can promote specific reaction, raise reaction rate and speed up preparation process.

In a second aspect, an embodiment of the present application provides a method for preparing the heat conductive and wave absorbing material, including: stirring and mixing the raw materials, and then carrying out vacuum treatment to obtain slurry; carrying out calendaring molding treatment on the slurry to obtain a sheet; heating and curing the sheet to obtain a first gasket; and (3) horizontally placing the first copper ring on the first gasket to obtain the heat-conducting wave-absorbing material.

In some embodiments of the present application, the rotational speed of the agitation is 2500-3500r/min and the time of the agitation is 15-30min.

In some embodiments of the present application, the temperature of the heat cure is 100-130℃and the time of the heat cure is 30-60 minutes.

In some embodiments of the present application, the thickness of the first spacer is 0.2-2mm.

In a third aspect, an embodiment of the present application provides an application of the above heat-conducting and wave-absorbing material in the radar technical field.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered limiting the scope, and that other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a heat conductive wave absorbing material prepared according to mode 1 in the present application;

fig. 2 is a schematic structural diagram 1 of a heat conducting and wave absorbing material prepared in mode 2 in the present application;

fig. 3 is a schematic structural diagram 2 of a heat conducting and wave absorbing material prepared in mode 2 in the present application.

Icon: 101-a first gasket; 102-a second gasket; 201-a first copper ring; 202-a second copper ring.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

The embodiment of the application provides a heat conduction wave-absorbing material, which comprises a first gasket 101 and a first copper ring 201 arranged on the first gasket 101; wherein the first gasket 101 comprises the following components in percentage by mass: 30-40% of wave absorber, 50-60% of heat conducting powder, 5-12% of silicone oil carrier, 0.01-0.03% of inhibitor and 0.1-0.4% of catalyst; the first copper ring 201 is formed into a ring shape by enclosing a copper pipe, and the ring-shaped copper pipe is the first copper ring 201.

The first copper ring 201 is arranged on the first gasket 101, and under the condition of electromagnetic wave irradiation, an interaction induction magnetic field is generated between the first copper ring 201 and an external electromagnetic field, and the interaction of the induction magnetic field and the external electromagnetic field further enhances the absorption and conversion of electromagnetic waves, so that the wave absorbing performance of a wave absorbing material can be further enhanced by adding the first copper ring 201. Also, by adding the first copper ring 201 to the wave-absorbing material, which has a resonance phenomenon in an environment having electromagnetic waves, the first copper ring 201 serves as a resonance ring, and the first copper ring 201 can also enhance impedance matching of the wave-absorbing material to enhance wave-absorbing performance. When the wave-absorbing material interacts with the electromagnetic field, the wave-absorbing material is more efficient in receiving and converting electromagnetic energy if its impedance matches that of the external electromagnetic field. Therefore, the addition of the first copper ring 201 can change the impedance property of the wave-absorbing material to be more matched with the impedance of the external electromagnetic field, so that the wave-absorbing performance of the wave-absorbing material can be improved. That is, the present application can enhance the wave absorbing performance by adding the first copper ring 201 to the wave absorbing material, which is mainly achieved by electromagnetic induction, electromagnetic conversion, impedance matching, and other mechanisms. These mechanisms work together to enable the wave-absorbing material to more effectively absorb and convert electromagnetic energy.

The impedance matching refers to the degree to which the impedance between two interconnected circuits or media is adapted to each other during the propagation or transfer of energy of electromagnetic waves. Impedance is the resistance of a circuit or medium to the propagation of electromagnetic waves, while the goal of impedance matching is to enable efficient transfer of energy from one system to another, reducing reflection and improving transmission efficiency.

The impedance matching of the wave-absorbing material with the external electromagnetic field means that the impedance of the wave-absorbing material matches the impedance of the surrounding environment or the electromagnetic field, which helps to improve the absorption and conversion efficiency of the wave-absorbing material to electromagnetic waves. If impedance matched properly, electromagnetic waves can enter the wave absorbing material more efficiently and the material can absorb and dissipate the energy of the electromagnetic waves more efficiently without substantial reflection. The first copper ring 201 in this application has a thickness of 50-200 μm, that is, the diameter of the annular copper tube is 50-200 μm.

In the application, the heat-conducting and wave-absorbing material further comprises a second copper ring 202 which is horizontally placed on the first gasket 101, the second copper ring 202 is located in the first copper ring 201, the diameter of the second copper ring 202 is 55-70% of the width of the first gasket 101, and the diameter of the first copper ring 201 is 85-95% of the width of the first gasket 101. The thickness of the second copper ring 202 is the same as that of the first copper ring 201, and the width of the first spacer 101 may be 5-300mm, or may be other dimensions, which may be determined according to specific material requirements, which is not limited in this application. For example, the first shim 101 may have a width of 300mm, the first copper ring 201 may have a diameter of 255-285mm, and the second copper ring 202 may have a diameter of 165-210mm. That is, the diameters of the first copper ring 201 and the second copper ring 202 are mainly determined by the width of the first spacer 101, which is not limited in this application.

The double copper ring acts more on itself with resonance characteristics than the single copper ring. When electromagnetic waves are incident on a single copper ring, induced current is generated in the copper ring, and an eddy current effect is formed. At resonance, the impedance of the single copper ring changes, thereby affecting the propagation and absorption of electromagnetic waves. The double copper rings can be regarded as being formed by connecting two single copper rings, and when electromagnetic waves are incident on the double copper rings, a coupling effect is generated between the two single copper rings, so that a complex resonance system is formed. The system has a higher impedance variation range and can absorb and attenuate electromagnetic waves more effectively.

In this application, the heat conducting and wave absorbing material further includes a second gasket 102, and the second gasket 102 and the first gasket 101 sandwich a first copper ring 201 and a second copper ring 202. The diameter of the second copper ring 202 is 55-70% of the width of the first gasket 101, the diameter of the first copper ring 201 is 85-95% of the width of the first gasket 101, and the size of the first gasket 101 is the same as the size of the second gasket 102, and the diameters of the first copper ring 201 and the second copper ring 202 mainly depend on the width of the first gasket 101, which is not limited in this application.

In the embodiment of the application, the wave absorber comprises at least one of carbonyl iron powder, silicon carbide, acetylene black and ferrite. Wherein the particle size of the carbonyl iron powder is 2-50 mu m. Carbonyl iron powder, silicon carbide, acetylene black, ferrite and other wave-absorbing materials have different wave-absorbing mechanisms in different frequency ranges. For example carbonyl iron powder is mainly concentrated in the medium and low frequency and radio frequency range, which absorbs electromagnetic wave energy mainly by magnetic losses under external magnetic fields. This is because the iron element in the iron powder undergoes magnetic anisotropy and hysteresis loop in an external magnetic field, resulting in energy dissipation. Silicon carbide mainly includes microwave and millimeter wave bands, and silicon carbide exhibits dielectric loss mainly due to the polarity of silicon-carbon bonds and molecular swing, and conductivity loss due to the conductive nature of the material. Both of these loss mechanisms cause silicon carbide to absorb electromagnetic wave energy. Dielectric losses are generally more pronounced in the high frequency range, while conductance losses are more pronounced in the low frequency range. Therefore, silicon carbide can exhibit excellent wave-absorbing performance over a wide frequency range. Acetylene black can include a range from radio frequencies to millimeter waves, which absorb electromagnetic waves primarily through electrical and magnetic losses, the conductivity and magnetic properties of the black being such that it absorbs energy efficiently at different frequencies. Ferrites are commonly used in low and medium frequency applications, which absorb electromagnetic waves primarily through magnetic losses, and which have high magnetic permeability, and which can absorb and release magnetic energy under external magnetic fields. Thus, the combined use of these wave-absorbing materials can optimize the wave-absorbing properties of the wave-absorbing materials, since they exhibit complementary wave-absorbing mechanisms in different frequency ranges. By adjusting the content and proportion of each component, the effective absorption of a specific frequency band can be realized. In addition, the combination of these wave-absorbing materials can also improve the applicability of the materials, so that the materials can play a role in wider electromagnetic environments.

The particle size of the carbonyl iron powder is limited to be in the range of 2-50 mu m, so that the carbonyl iron powder can show better wave absorbing effect on electromagnetic waves with different frequencies; it may also help to improve the dispersibility of the material, i.e. the particles are uniformly distributed in the matrix. The uniformly dispersed particles can better interact with the matrix, and the electromagnetic wave absorption is improved. In addition, the particle size range helps to stabilize the properties of the material. And carbonyl iron powder in the above particle size range is easier to process and mix into the gasket 201, which can facilitate control of the production process and provide consistent performance of the final prepared heat conductive wave absorbing material.

In the embodiment of the application, the wave absorber is a mixture of carbonyl iron powder, silicon carbide, acetylene black and ferrite with different particle sizes, and comprises the following components in percentage by mass: 25-30% of 2.7 mu m carbonyl iron powder, 6-10% of 10 mu m carbonyl iron powder, 12-16% of 50 mu m carbonyl iron powder, 3-8% of silicon carbide, 1-5% of acetylene black and 40-44% of ferrite; or the wave absorber is a mixture of carbonyl iron powder, silicon carbide and acetylene black with different particle sizes, and comprises the following components in percentage by mass: 68-73% of 2.7 mu m carbonyl iron powder, 6-10% of 10 mu m carbonyl iron powder, 12-16% of 50 mu m carbonyl iron powder, 3-8% of silicon carbide and 1-5% of acetylene black; or the wave absorber is a mixture of carbonyl iron powder, silicon carbide and ferrite with different particle sizes, and comprises the following components in percentage by mass: 25-30% of 2.7 mu m carbonyl iron powder, 6-10% of 10 mu m carbonyl iron powder, 12-16% of 50 mu m carbonyl iron powder, 3-8% of silicon carbide and 41-44% of ferrite; or the wave absorber is a mixture of carbonyl iron powder with different particle sizes, and comprises the following components in percentage by mass: 68-73% of 2.7 mu m carbonyl iron powder, 12-16% of 10 mu m carbonyl iron powder and 12-16% of 50 mu m carbonyl iron powder.

In the embodiment of the application, the heat conductive powder includes at least one of aluminum oxide powder, aluminum nitride powder, zinc oxide powder, graphene powder, boron nitride powder, and diamond powder. Wherein the particle size of the alumina powder is 0.5-120 μm. The aluminum oxide has better heat conductivity, and can show better electromagnetic wave absorption performance in a high-frequency range, and has good wave absorbing effect on electromagnetic waves with microwave and other frequencies. Aluminum nitride has excellent heat conducting performance, which is far higher than aluminum oxide, and is a material with high heat conductivity. In the high frequency range, aluminum nitride also shows good electromagnetic wave absorption performance, and is suitable for high-frequency electromagnetic wave absorbing materials. Zinc oxide has good heat conducting performance, and can show good electromagnetic wave absorption performance in a certain frequency range, especially in ultraviolet light and visible light ranges. Graphene has excellent heat conduction properties, and is one of the materials with the best known heat conduction. The graphene has excellent electromagnetic wave absorption performance in a wide frequency range, and has remarkable effects on frequency bands such as microwaves, millimeter waves and the like. Boron nitride has better heat conductivity and is a ceramic material with high heat conductivity. In the high frequency range, the boron nitride can show better electromagnetic wave absorption performance, and is suitable for some high frequency application scenes. Diamond is one of the materials with the best thermal conductivity in nature, has extremely high thermal conductivity, and can also show certain electromagnetic wave absorption performance in a high-frequency range. Therefore, the effective heat conducting performance in a wide frequency range can be realized by selecting various heat conducting powder, and the heat conducting effect of the whole material is improved. The wave absorbing performance of the wave absorbing material under different frequencies can be optimized, and a wider application range is provided.

The alumina powder with the grain diameter of 0.5-120 mu m can better improve the heat conduction performance and electromagnetic wave absorption performance of the heat conduction wave-absorbing material.

In this embodiment of the application, the heat conductive powder includes, in percentage by mass: 1-5% of 0.5 mu m alumina powder, 35-50% of 75 mu m alumina powder, 5-15% of zinc oxide powder, 1-5% of graphene powder and 35-50% of aluminum nitride powder; or, the heat conducting powder comprises the following components in percentage by mass: 1-5% of 0.5 mu m alumina powder, 38-62% of 75 mu m alumina powder, 8-20% of zinc oxide powder, 38-62% of aluminum nitride powder and 8-20% of boron nitride powder; or, the heat conducting powder comprises the following components in percentage by mass: 1-5% of 0.5 mu m alumina powder, 35-50% of 75 mu m alumina powder, 35-50% of aluminum nitride powder, 8-15% of boron nitride powder and 1-5% of graphene powder; or, the heat conducting powder comprises the following components in percentage by mass: 45-60% of 75 mu m aluminum oxide powder, 5-15% of zinc oxide powder, 1-7% of graphene powder and 30-45% of aluminum nitride powder.

In embodiments of the present application, the silicone oil carrier comprises a vinyl silicone oil and/or an H-containing silicone oil. The vinyl silicone oil and the H-containing silicone oil have good heat conduction performance, are favorable for improving the overall heat conduction of the heat conduction wave-absorbing material, and enable the material to conduct heat efficiently in the electromagnetic wave absorption process. In addition, the vinyl silicone oil and the H-containing silicone oil have lower viscosity, are favorable for improving the fluidity of the material, and can enable the material to be better suitable for surfaces with different shapes. In addition, vinyl silicone oils and H-containing silicone oils have a high thermal stability and can be operated at relatively high temperatures without losing their properties.

In the present application, the viscosity of the H-containing silicone oil is in the range of 100-1000mpa.s and the viscosity of the vinyl silicone oil is in the range of 500-100000mpa.s. The viscosity of the vinyl silicone oil includes, but is not limited to, 500cps, 1000cps, 2000cps, 3000cps, 4000cps, 5000cps, 6000cps, 7000cps, 8000cps, 9000cps, 10000cps, 20000cps, 30000cps, 40000cps, 50000cps, 60000cps, 70000cps, 80000cps, 90000cps, 100000cps; the viscosity of the H-containing silicone oil includes, but is not limited to, 100cps, 300cps, 500cps, 600cps, 700cps, 800cps, 900cps, 1000cps.

In embodiments of the present application, the inhibitors include ethynyl cyclohexanol and/or methylbutynol. The inhibitor has the function of controlling the operation time of the product at normal temperature and preventing the cross-linking and curing from being too fast and affecting the implementation of the calendaring molding process.

In embodiments of the present application, the catalyst comprises a platinum catalyst. Platinum is a high-efficiency catalyst and has good catalytic activity. It can promote specific reaction, raise reaction rate and speed up preparation process.

The method for preparing the heat-conducting and wave-absorbing material is further described below.

The preparation method of the heat-conducting wave-absorbing material comprises the following steps:

(1) And stirring and mixing the raw materials, and then carrying out vacuum treatment to obtain slurry. Wherein the stirring speed is 2500-3500r/min, and the stirring time is 15-30min.

(2) And (3) carrying out calendaring molding treatment on the slurry prepared in the step (1) to obtain the sheet.

(3) And (3) performing heat curing treatment on the sheet in the step (2) to obtain a first gasket 101. Wherein the temperature of the heating and curing is 100-130 ℃, and the time of the heating and curing is 30-60min.

In the embodiment of the present application, the thickness of the first spacer 101 is 0.2-2mm.

(4) The first copper ring 201 is placed on the first pad 101, and the heat conducting and wave absorbing material is obtained. After the first copper ring 201 is placed on the first pad 101, the first copper ring 201 is further bonded by using conductive glue, so that the first copper ring 201 can be placed on the first pad 101 firmly.

The second copper ring 202 and the second gasket 102 can also be added into the heat-conducting and wave-absorbing material, so that the heat-conducting and wave-absorbing material provided by the application can be prepared in the following two modes, namely mode 1: placing the first copper ring 201 and/or the second copper ring 202 on the first gasket 101, wherein if the first copper ring 201 and the second copper ring 202 exist at the same time, the second copper ring 202 is positioned in the first copper ring 201; then bonding the first copper ring 201 and the second copper ring 202 to the first gasket 101 using a conductive adhesive; then coating the slurry prepared in the step (1) on the surfaces of the first copper ring 201 and the second copper ring 202 to form a second gasket 102, wherein the size of the second gasket 102 is the same as that of the first gasket 101, which is equivalent to the fact that the first copper ring 201 and the second copper ring 202 are clamped between the second gasket 102 and the first gasket 101; then, calendaring and forming treatment is carried out, and finally the heat conduction wave-absorbing material with the required thickness and the first copper ring 201 and/or the second copper ring 202 is obtained. In the heat-conducting wave-absorbing material, if the thickness of the heat-conducting wave-absorbing material is 1mm, the thickness of the two gaskets is 0.5mm respectively. Mode 2: placing the first copper ring 201 and/or the second copper ring 202 on the first gasket 101, wherein if the first copper ring 201 and the second copper ring 202 exist at the same time, the second copper ring 202 is positioned in the first copper ring 201; and then bonding the first copper ring 201 and the second copper ring 202 on the first gasket 101 by using an electric conduction adhesive to obtain the heat conduction wave-absorbing material with the first copper ring 201 and/or the second copper ring 202.

The schematic structural diagrams of the heat-conducting and wave-absorbing material prepared in the mode 1 are shown in fig. 1 and 3, and the schematic structural diagram of the heat-conducting and wave-absorbing material prepared in the mode 2 is shown in fig. 2.

The preparation of the conductive adhesive comprises the following steps: copper powder or silver powder with different particle sizes is added into acrylic resin or epoxy resin, wherein the epoxy resin comprises but is not limited to thermosetting epoxy resin unsaturated polyester, acrylic epoxy resin, triphosphazene epoxy resin, dicyclopentadiene epoxy resin, polybutadiene epoxy resin, organic titanium epoxy resin, organic silicon epoxy resin and fluorine-containing epoxy resin; the mass ratio of the copper powder or the silver powder is 80-95%, and the rest is resin. Particle sizes of copper powder or silver powder include, but are not limited to, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm.

The features and capabilities of the present application are described in further detail below in connection with the examples.

Example 1

The embodiment provides a heat-conducting wave-absorbing material, and the preparation method thereof comprises the following steps:

(1) 35g of a wave absorber (wherein, carbonyl iron powder 2.7 μm 10g, 50 μm 5g, 10 μm 3g, siC 2g, acetylene black 1g, ferrite 15 g), 55g of a heat conductive powder (wherein, alumina powder 0.5 μm1.5g, alumina powder 75 μm 17g, zinc oxide powder 3 μm 5g, graphene powder 1 μm1.5g and aluminum nitride powder 120 μm 30 g), 4.8g of vinyl silicone oil 1000cps, 1.2g of vinyl silicone oil 10000cps, 0.4g of H-containing silicone oil, 0.02g of ethynyl cyclohexanol and 0.2g of platinum catalyst) were stirred and mixed, followed by vacuum treatment to obtain a slurry. Wherein the stirring speed is 3000r/min, and the stirring time is 25min.

(2) And (3) carrying out calendaring molding treatment on the slurry prepared in the step (1) to obtain a sheet with the thickness of 0.5mm.

(3) The sheet in step (2) was subjected to heat curing treatment to obtain a first gasket 101 (thickness of 0.5mm, width of 300 mm). Wherein the temperature of the heating and curing is 130 ℃, and the time of the heating and curing is 45min.

(4) Placing a first copper ring 201 (100 μm thick and 270mm diameter) and a second copper ring 202 (100 μm thick and 180mm diameter) on the first spacer 101 in step (3), the second copper ring 202 being located within the first copper ring 201; then bonding the first copper ring 201 and the second copper ring 202 to the first gasket 101 using a conductive adhesive; then coating the slurry prepared in the step (1) on the surfaces of the first copper ring 201 and the second copper ring 202 to form a second gasket 102, wherein the size of the second gasket 102 is the same as that of the first gasket 101, which is equivalent to the fact that the first copper ring 201 and the second copper ring 202 are clamped between the second gasket 102 and the first gasket 101; then, a calendaring process is performed, and finally the heat conduction wave-absorbing material with the first copper ring 201 and the second copper ring 202 is obtained, wherein the thickness of the heat conduction wave-absorbing material is 1mm.

Example 2

This embodiment is substantially the same as embodiment 1 except that: the compositions of the wave absorbers were different, wherein the carbonyl iron powder was 2.7 μm 25g, 50 μm 5g, 10 μm 3g, siC 2g, and acetylene black 1g.

Example 3

This embodiment is substantially the same as embodiment 1 except that: the compositions of the wave absorbers were different, wherein the carbonyl iron powder was 2.7 μm 10g, 50 μm 5g, 10 μm 3g, siC 2g, and ferrite 15g.

Example 4

This embodiment is substantially the same as embodiment 1 except that: the composition of the heat conductive powder was different, in which alumina powder 0.5 μm1.5g, alumina powder 75 μm 23.5g, zinc oxide powder 3 μm 5g, aluminum nitride powder 120 μm 20g, and boron nitride 10 μm 5g.

Example 5

This embodiment is substantially the same as embodiment 1 except that: the composition of the heat conductive powder was different, in which alumina powder 0.5 μm1.5g, alumina powder 75 μm 25g, aluminum nitride powder 120 μm 22g, boron nitride 10 μm 5.5g, and graphene powder 1 μm 1g.

Example 6

This comparative example is substantially the same as example 1, except that: the diameter of the first copper ring 201 is 294mm and the diameter of the second copper ring 202 is 180mm.

Example 7

This comparative example is substantially the same as example 1, except that: the diameter of the first copper ring 201 is 225mm and the diameter of the second copper ring 202 is 180mm.

Example 8

This comparative example is substantially the same as example 1, except that: the diameter of the first copper ring 201 is 270mm and the diameter of the second copper ring 202 is 240mm.

Example 9

This comparative example is substantially the same as example 1, except that: the diameter of the first copper ring 201 is 270mm and the diameter of the second copper ring 202 is 135mm.

Example 10

This embodiment is substantially the same as embodiment 1 except that: only the first copper ring 201 is used, and the diameter of the first copper ring 201 is 270mm.

Comparative example

This comparative example is substantially the same as example 1, except that: the first copper ring 201 and the second copper ring 202 are not added; the preparation method comprises the following steps:

(1) 35g of a wave absorber (wherein, carbonyl iron powder 2.7 μm 10g, 50 μm 5g, 10 μm 3g, siC 2g, acetylene black 1g, ferrite 15 g), 55g of a heat conductive powder (wherein, alumina powder 0.5 μm1.5g, alumina powder 75 μm 17g, zinc oxide powder 3 μm 5g, graphene powder 1 μm1.5g and aluminum nitride powder 120 μm 30 g), 4.8g of vinyl silicone oil 1000cps, 1.2g of vinyl silicone oil 10000cps, 0.4g of H-containing silicone oil, 0.02g of ethynyl cyclohexanol and 0.2g of platinum catalyst) were stirred and mixed, followed by vacuum treatment to obtain a slurry. Wherein the stirring speed is 3000r/min, and the stirring time is 25min.

(2) And (3) sequentially carrying out calendaring molding treatment and heating curing treatment on the slurry prepared in the step (1) to obtain the heat-conducting wave-absorbing material with the thickness of 1mm. Wherein the temperature of the heating and curing is 130 ℃, and the time of the heating and curing is 45min.

Test examples

In the test example, the heat conduction wave-absorbing materials prepared in the comparative examples 1 to 8 are subjected to performance tests, including a heat conduction coefficient test and a wave-absorbing reflection loss test; the heat conductivity coefficient test is performed according to a standard ASTM D5470, and the wave-absorbing reflection loss test is performed according to a standard GJB 2038A-2011; the test results of the thermal conductivity test and the absorption reflection loss test are shown in table 1.

TABLE 1

As can be seen from Table 1, the heat conduction wave-absorbing material provided by the application has a limited absorption frequency range of-10 db from 15GHz to 30GHz, and a peak value of-45 db at 21 GHz. The effective absorption bandwidth is increased from the original 7G width to 15G width, and the wave absorption peak value is increased from-20 db to-45 db.

As can be seen from comparing examples 1 and 6 to 9, the diameter of the second copper ring 202 is 55 to 70% of the width of the first gasket 101, and when the diameter of the first copper ring 201 is 85 to 95% of the width of the first gasket 101, the prepared heat conductive wave absorbing material has the best effect in both directions of 90 degrees of incidence angle and 0 degrees of incidence angle, and the effect of adding the copper ring is more obvious at the low incidence angle.

The embodiments described above are some, but not all, of the embodiments of the present application. The detailed description of the embodiments of the present application is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

Claims (10)

1. The heat conduction wave-absorbing material is characterized by comprising a first gasket and a first copper ring which is horizontally arranged on the first gasket; wherein, the first gasket comprises the following components in percentage by mass:

30-40% of wave absorber, 50-60% of heat conducting powder, 5-12% of silicone oil carrier, 0.01-0.03% of inhibitor and 0.1-0.4% of catalyst.

2. The heat conductive wave absorbing material of claim 1, wherein the thickness of the first copper ring is 50-200 μm in the thickness direction of the first spacer;

optionally, the heat-conducting and wave-absorbing material further comprises a second copper ring which is horizontally placed on the first gasket, the second copper ring is located in the first copper ring, the diameter of the second copper ring is 55-70% of the width of the first gasket, and the diameter of the first copper ring is 85-95% of the width of the first gasket; the thickness of the second copper ring is the same as that of the first copper ring;

optionally, the heat conducting and wave absorbing material further comprises a second gasket, and the first gasket and the second gasket sandwich the first copper ring and the second copper ring.

3. The thermally conductive wave-absorbing material of claim 1, wherein the wave-absorbing agent comprises at least one of carbonyl iron powder, silicon carbide, acetylene black, and ferrite;

optionally, the particle size of the carbonyl iron powder is 2-50 μm.

4. A thermally conductive wave-absorbing material as claimed in claim 3, wherein the wave-absorbing agent is a mixture of carbonyl iron powder, silicon carbide, acetylene black and ferrite of different particle sizes, comprising, in mass percent: 25-30% of 2.7 mu m carbonyl iron powder, 6-10% of 10 mu m carbonyl iron powder, 12-16% of 50 mu m carbonyl iron powder, 3-8% of silicon carbide, 1-5% of acetylene black and 40-44% of ferrite;

or the wave absorber is a mixture of carbonyl iron powder, silicon carbide and acetylene black with different particle sizes, and comprises the following components in percentage by mass: 68-73% of 2.7 mu m carbonyl iron powder, 6-10% of 10 mu m carbonyl iron powder, 12-16% of 50 mu m carbonyl iron powder, 3-8% of silicon carbide and 1-5% of acetylene black;

or the wave absorber is a mixture of carbonyl iron powder, silicon carbide and ferrite with different particle sizes, and comprises the following components in percentage by mass: 25-30% of 2.7 mu m carbonyl iron powder, 6-10% of 10 mu m carbonyl iron powder, 12-16% of 50 mu m carbonyl iron powder, 3-8% of silicon carbide and 41-44% of ferrite;

or the wave absorber is a mixture of carbonyl iron powder with different particle sizes, and comprises the following components in percentage by mass: 68-73% of 2.7 mu m carbonyl iron powder, 12-16% of 10 mu m carbonyl iron powder and 12-16% of 50 mu m carbonyl iron powder.

5. A thermally conductive wave-absorbing material according to any one of claims 1-3, wherein the thermally conductive powder comprises at least one of an aluminum oxide powder, an aluminum nitride powder, a zinc oxide powder, a graphene powder, a boron nitride powder, and a diamond powder;

optionally, the alumina powder has a particle size of 0.5-120 μm.

6. The heat conducting and wave absorbing material according to claim 5, wherein the heat conducting powder comprises, in mass percent: 1-5% of 0.5 mu m alumina powder, 35-50% of 75 mu m alumina powder, 5-15% of zinc oxide powder, 1-5% of graphene powder and 35-50% of aluminum nitride powder;

or, the heat conducting powder comprises the following components in percentage by mass: 1-5% of 0.5 mu m alumina powder, 38-62% of 75 mu m alumina powder, 8-20% of zinc oxide powder, 38-62% of aluminum nitride powder and 8-20% of boron nitride powder;

or, the heat conducting powder comprises the following components in percentage by mass: 1-5% of 0.5 mu m alumina powder, 35-50% of 75 mu m alumina powder, 35-50% of aluminum nitride powder, 8-15% of boron nitride powder and 1-5% of graphene powder;

or, the heat conducting powder comprises the following components in percentage by mass: 45-60% of 75 mu m aluminum oxide powder, 5-15% of zinc oxide powder, 1-7% of graphene powder and 30-45% of aluminum nitride powder.

7. A thermally conductive wave-absorbing material according to any of claims 1-4, wherein the silicone oil carrier comprises vinyl silicone oil and/or H-containing silicone oil;

optionally, the inhibitor comprises ethynyl cyclohexanol and/or methylbutynol;

optionally, the catalyst comprises a platinum catalyst.

8. A method for producing the heat conductive wave absorbing material according to any one of claims 1 to 7, comprising:

stirring and mixing the raw materials, and then carrying out vacuum treatment to obtain slurry; carrying out calendaring molding treatment on the slurry to obtain a sheet; heating and curing the sheet to obtain the first gasket; and placing the first copper ring on the first gasket horizontally to obtain the heat-conducting wave-absorbing material.

9. The method according to claim 8, wherein the stirring speed is 2500-3500r/min, and the stirring time is 15-30min;

optionally, the temperature of the heating and curing is 100-130 ℃, and the time of the heating and curing is 30-60min;

optionally, the thickness of the first spacer is 0.2-2mm.

10. Use of a thermally conductive wave-absorbing material as claimed in any one of claims 1 to 7 in the field of radar technology.