CN112208183A - Composite wave-absorbing material and preparation method thereof - Google Patents
Composite wave-absorbing material and preparation method thereof Download PDFInfo
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- CN112208183A CN112208183A CN202010993334.9A CN202010993334A CN112208183A CN 112208183 A CN112208183 A CN 112208183A CN 202010993334 A CN202010993334 A CN 202010993334A CN 112208183 A CN112208183 A CN 112208183A
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- B32B27/00—Layered products comprising a layer of synthetic resin
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- B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
- B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
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- B32B33/00—Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
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Abstract
The invention discloses a composite wave-absorbing material and a preparation method thereof, wherein the composite wave-absorbing material comprises the following components: the wave absorbing layers comprise a wave absorbing agent and first epoxy resin, and the curing temperature of the first epoxy resin is 130-180 ℃, and the viscosity of the first epoxy resin at 50 ℃ is 2000-8000 mPa & s; the epoxy resin layer is arranged among the wave absorbing layers and comprises second epoxy resin and a curing agent, the curing temperature of the second epoxy resin is 170-200 ℃, and the viscosity of the second epoxy resin at 50 ℃ is 20000-70000 mPa & s. The compatibility of the first epoxy resin and wave absorbent particles is good, the second epoxy resin has better extension tensile property, the addition of the curing agent can improve the crosslinking degree of the cured second epoxy resin, so that the bonding between wave absorbing layers is stable, and the problems that a single layered structure cannot meet the wave impedance matching and high loss performance at the same time are solved.
Description
Technical Field
The invention relates to the technical field of wave-absorbing materials, in particular to a composite wave-absorbing material and a preparation method thereof.
Background
With the rapid development of the electronic industry, serious electromagnetic wave pollution is generated in communication systems, science, medical equipment and the like, and great interference is caused to the operation of high-precision instruments, so that the preparation of a high-efficiency wave-absorbing material is necessary. In the military field, the wave-absorbing material can absorb electromagnetic waves emitted by enemy radars, reduce the probability of reconnaissance and discovery of own military units such as airplanes, missiles and the like, and improve the strategic deterrence, so that the comprehensive performance of the equipped wave-absorbing material can control the victory or defeat of one war to a great extent.
The absorption efficiency of the wave-absorbing material to the electromagnetic wave depends on the incidence and loss of the electromagnetic wave. The incident rate of the electromagnetic waves is improved, the electromagnetic performance of the wave-absorbing material is required to be similar to that of air, and wave impedance matching is achieved, so that the reflectivity of the incident electromagnetic waves on the surface of the wave-absorbing material is reduced; the improvement of the loss of the incident electromagnetic wave requires that the wave-absorbing material has electromagnetic wave attenuation performance different from that of air, which is contradictory to the above requirements. At present, the wave-absorbing material on the market mostly adopts a single layered structure, and can only meet one of wave impedance matching or high loss performance, so that the produced wave-absorbing material cannot simultaneously have the characteristics of wide frequency band, strong absorption and the like.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art. Therefore, the composite wave-absorbing material provided by the invention can set the content of the wave-absorbing agent in the multiple wave-absorbing layers according to requirements, and avoids the problem that a single layered structure cannot simultaneously meet the wave impedance matching and high loss performance.
The invention also provides a preparation method of the composite wave-absorbing material.
The composite wave-absorbing material provided by the embodiment of the first aspect of the invention comprises:
the wave absorbing layers comprise a wave absorbing agent and first epoxy resin, and the curing temperature of the first epoxy resin is 130-180 ℃, and the viscosity of the first epoxy resin at 50 ℃ is 2000-8000 mPa & s;
the epoxy resin layer is arranged among the wave absorbing layers and comprises second epoxy resin and a curing agent, the curing temperature of the second epoxy resin is 170-200 ℃, and the viscosity of the second epoxy resin at 50 ℃ is 20000-70000 mPa & s.
The composite wave-absorbing material provided by the embodiment of the invention at least has the following beneficial effects:
the composite wave-absorbing material provided by the embodiment of the invention can set the content of the wave-absorbing agent in the multiple wave-absorbing layers according to requirements, and avoids the problem that a single layered structure cannot simultaneously meet the wave impedance matching and high loss performance. In addition, the first epoxy resin adopted in the wave absorbing layer is high-temperature epoxy resin, the curing temperature is 130-180 ℃, the viscosity is 2000-8000 mPa.s (50 ℃), the compatibility with wave absorbing agent particles is good, and a tight combination part can be formed. Different from the first epoxy resin in the wave-absorbing layer, the second epoxy resin used in the epoxy resin layer has better extension tensile property, the addition of the curing agent can improve the crosslinking degree of the cured second epoxy resin, and the formed epoxy resin layer as the middle layer can ensure the bonding between the wave-absorbing layers to be stable, and is particularly embodied in the wave-absorbing layer with high wave-absorbing agent content (more than or equal to 80%). In addition, the properties of the first epoxy resin used in the wave absorbing layer and the second epoxy resin used in the epoxy resin layer are different, so that the composite wave absorbing material can be bonded firmly without hot pressing (namely, hot pressing is avoided) in the preparation process, and the problem that the wave absorbing layers with high wave absorbing agent content are difficult to tightly attach is solved.
According to some embodiments of the invention, the mass fraction of the wave absorbing agent in the plurality of wave absorbing layers is gradually increased or decreased along the thickness direction of the composite wave absorbing material. The content of the wave absorbing agent in the wave absorbing layer is gradually increased or gradually decreased to form the composite wave absorbing material with a gradual change type structure, which can simultaneously meet the impedance matching with air waves and the high loss performance to incident waves and is an ideal wave absorbing material.
According to some embodiments of the invention, the wave absorbing agent comprises at least two of iron nitride, iron hydroxyl powder, iron-silicon-aluminum powder, activated carbon fiber, carbon nanotube, hollow glass bead. The iron nitride, the hydroxyl iron powder and the iron-silicon-aluminum powder are used for absorbing and losing incident electromagnetic waves, the activated carbon fiber and the carbon nano tube are used for improving the mechanical property of the composite material, and the cavity of the hollow glass bead can be used as a resonant cavity of the electromagnetic waves and can enhance the loss capacity of the composite material to the incident electromagnetic waves.
According to some embodiments of the invention, the wave absorbing agent comprises iron hydroxyl powder and hollow glass microspheres.
According to some embodiments of the invention, the curing agent is methyl tetrahydrophthalic anhydride or dicyandiamide.
According to some embodiments of the invention, in the epoxy resin layer, a mass ratio of the curing agent to the second epoxy resin is 1: (1.5 to 3).
According to some embodiments of the present invention, the wave-absorbing layer further includes an organic solvent, and the organic solvent is at least two of ethyl acetate, N-dimethylformamide, absolute ethyl alcohol, and acetone.
The preparation method of the composite wave-absorbing material according to the embodiment of the second aspect of the invention comprises the following steps:
taking the raw materials of the wave absorbing layer and the epoxy resin layer, and preparing and forming a plurality of double-layer green sheets by using a double-layer slit coating process;
and overlapping a plurality of double-layer green sheets, and heating and curing to obtain the composite wave-absorbing material.
The preparation method of the composite wave-absorbing material according to the embodiment of the invention at least has the following beneficial effects:
according to the embodiment of the invention, a double-layer slit coating machine is utilized to prepare the material of the wave-absorbing layer and the material of the epoxy resin layer into a double-layer green sheet coated on the surface of the base material, the base material at the bottom is torn off, then the double-layer green sheet is superposed to obtain a precursor of the multi-layer composite wave-absorbing material with the epoxy resin layer as a middle layer, and then the precursor is heated and cured to obtain the composite wave-absorbing material. The preparation method provided by the embodiment of the invention is simple and convenient, has high stacking efficiency and is beneficial to large-scale industrial production.
According to some embodiments of the invention, before the stacking, the double-layer green sheet is further subjected to a drying treatment, wherein the temperature of the drying treatment is increased from 30-40 ℃ to 90-100 ℃, and then is cooled to 25-35 ℃. In the drying treatment process, if the constant high temperature is kept, the solvent in the green sheet is quickly volatilized and can be quickly dried, but thermal shock caused by the drastic temperature change can crack the green sheet and influence the subsequent process; if the drying is kept at a lower temperature, the drying rate is slow, which is not favorable for continuous production. Compared with a drying mode at a constant temperature, the drying method has the advantages that the drying speed and the drying quality can be considered by adopting gradient temperature rise, the temperature is reduced gradually, the influence of thermal shock on the green sheet can be reduced, meanwhile, the viscosity of resin can be reduced by reducing the temperature, and the phenomenon that the roll is stuck when the roll passes through the roll and the overall appearance of the roll is damaged is avoided.
According to some embodiments of the invention, the raw materials of the wave-absorbing layer or the raw materials of the epoxy resin layer in the step (1) are processed by a ball milling method, the ball milling speed is 200-400 r/min, and the ball milling time is 2-12 hours.
According to some embodiments of the invention, the double-layer slit coating process is provided with the first slits with the spacing of 20-40 μm, so as to control the thickness of the epoxy resin layer to be a thin film resin layer, and the epoxy resin layer is used for bonding each wave-absorbing layer and not influencing the wave-absorbing performance as much as possible. The distance between the second slits is 200-300 mu m, and the thickness of the single-layer wave-absorbing layer is adjusted to be 200-300 mu m.
Drawings
The invention is further described with reference to the following figures and examples, in which:
FIG. 1 is a schematic structural view of a composite wave-absorbing material in example 1;
FIG. 2 is a schematic view of a process flow for preparing the composite wave-absorbing material in example 1;
fig. 3 is a schematic structural view of the apparatus used in the double-slit coating process in example 1;
FIG. 4 is a representation of the wave-absorbing material of comparative example 2 by means of an optical microscope;
FIG. 5 is a representation of the composite wave-absorbing material of example 4 by an optical microscope.
Reference numerals: 100-hydroxyl iron powder, 200-hollow glass beads, 300-epoxy resin layer, 1-first trough, 2-second trough, 3-precision screw pump, 4-motor, 5-double-layer slit coater, 6-first slit, 7-second slit, 8-carrier roller, 9-PET film roll, 10-middle layer, 11-functional layer, 12-PET film substrate, 13-leading-off roller, 14-a plurality of ovens, 15-slicer and 16-winder.
Detailed Description
The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.
In the description of the invention, several means more than one. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.
Example 1
The wave absorbing agent used in the embodiment is hydroxyl iron powder and hollow glass beads, the curing temperature of the epoxy resin a is 130-180 ℃, the viscosity at 50 ℃ is 4500-5800 mPa & s, the curing temperature of the epoxy resin b is 170-200 ℃, the viscosity at 50 ℃ is 35000-42000 mPa & s, and the structural schematic diagram of the prepared composite wave absorbing material is shown in figure 1, wherein 100 is hydroxyl iron powder, 200 is hollow glass beads, and 300 is an epoxy resin layer, and the preparation process refers to figure 2, and the composite wave absorbing material is specifically prepared according to the following steps:
5 g of hydroxyl iron powder, 3 g of hollow glass beads, 100 g of epoxy resin a and 16 ml of organic solvent (obtained by mixing ethyl acetate and N, N-dimethylformamide according to a ratio of 1: 1) are respectively added into a tank body of a planetary ball mill, ball milling is carried out for 3 hours at a speed of 350r/min, and slurry obtained after filtration is sealed for later use. The slurry is marked as P5, wherein the wave absorbing agent (hydroxyl iron powder and hollow glass beads) accounts for about 5 percent;
30 g of hydroxyl iron powder, 4 g of hollow glass beads, 100 g of epoxy resin a and 20 ml of organic solvent (obtained by mixing ethyl acetate and N, N-dimethylformamide according to a ratio of 1: 1) are respectively added into a tank body of a planetary ball mill, ball milling is carried out for 3 hours at a speed of 350r/min, and slurry obtained after filtration is sealed for later use. The slurry is designated as P25, wherein the wave absorbing agent (hydroxyl iron powder and hollow glass beads) accounts for about 25 percent;
78 g of hydroxyl iron powder, 5 g of hollow glass beads, 100 g of epoxy resin a and 27 ml of organic solvent (obtained by mixing ethyl acetate and N, N-dimethylformamide according to a ratio of 1: 1) are respectively added into a tank body of a planetary ball mill, ball milling is carried out for 3 hours at a speed of 350r/min, and slurry obtained after filtration is sealed for later use. The slurry was designated as P45, in which the wave absorber (iron hydroxyl powder + hollow glass beads) accounted for about 45%;
177 g of hydroxyl iron powder, 8 g of hollow glass beads, 100 g of epoxy resin a and 43 ml of organic solvent (obtained by mixing ethyl acetate and N, N-dimethylformamide according to a ratio of 1: 1) are respectively added into a tank body of a planetary ball mill, ball milling is carried out for 3 hours at a speed of 350r/min, and slurry obtained after filtration is sealed for later use. The slurry was designated as P65, in which the wave absorber (iron hydroxyl powder + hollow glass beads) accounted for about 65%;
547 g of hydroxyl iron powder, 20 g of hollow glass beads, 100 g of epoxy resin a and 100 ml of organic solvent (obtained by mixing ethyl acetate and N, N-dimethylformamide according to a ratio of 1: 1) are respectively added into a tank body of a planetary ball mill, ball milling is carried out for 3 hours at a speed of 350r/min, and slurry obtained after filtration is sealed for later use. The slurry is designated as P85, wherein the wave absorbing agent (hydroxyl iron powder and hollow glass beads) accounts for about 85 percent;
weighing 100 g of epoxy resin b, 35 g of curing agent methyltetrahydrophthalic anhydride and 115 ml of organic solvent, adding into a ball milling tank, ball milling for 6 hours at the speed of 300r/min, filtering to obtain slurry, and removing bubbles in vacuum for 30 minutes for later use, wherein the vacuum degree is 0.08 MPa. The resulting paste was designated as P0, and was a resin paste for preparing an intermediate layer.
The slurry is transferred to a trough in batches, and the double-layer wave-absorbing material is prepared by a double-layer slit coating process shown in figure 3. The specific experimental steps are set as follows:
transferring the slurry P0 to a first tank 1 of a double-layer slit coating apparatus 5, using a precision screw pump 3 and a motor 4, and adjusting the extrusion pitch of a first slit 6 to 30 μm; the slurry P65 was transferred to the second tank 2 of the two-layer slit coater 5, and the extrusion pitch of the second slit 7 was adjusted to 250 μm. The running speed is 0.3m/min, the slurry P0 and P65 is made into a double-layer green sheet consisting of an epoxy resin layer and a wave-absorbing layer by a double-layer slit coating machine 5, meanwhile, a carrier roller 8 is used for combining a base material provided by a PET film roll 9 with the double-layer green sheet, then a guide roller 13 is used for sending the double-layer green sheet into an oven 14 for heating treatment, the temperature gradient of the oven is set to be 30-60-85-75-60-50-40 ℃, the dried green tape is trimmed by a slicer 15, and is rolled by a rolling device 16 and stored for later use. The double-layer green tape prepared by the method is marked as M65, and comprises an epoxy resin layer 10, a wave-absorbing layer 11 and a PET film substrate 12, wherein the composite wave-absorbing agent accounts for 65% of the wave-absorbing layer.
Transferring the slurry P0 to a first tank 1 of a two-layer slit coater 5, and adjusting the extrusion pitch of a first slit 6 to 30 μm; the slurry P85 was transferred to the second tank 2 of the two-layer slit coater 5, and the extrusion pitch of the second slit 7 was adjusted to 250 μm. The running speed is 0.3m/min, the temperature gradient of the oven is set to be 30-60-85-75-60-50-40 ℃, and the dried raw belt is trimmed, rolled and stored for later use. The double-layer green tape prepared by the method is named as M85, and comprises an epoxy resin layer formed by slurry P0 and a wave absorbing layer formed by slurry P85, wherein the wave absorbing agent accounts for 85% of the wave absorbing layer.
Hot-pressing-free lamination curing: taking two layers of raw belts M5, M25, M45, M65 and M85 with the same area, and tearing off the PET film substrate for standby. Sequentially and orderly overlapping M5, M25, M45, M65 and M85 from bottom to top, lightly pressing to enable the layers to be tightly attached to each other to obtain a multilayer green tape, and then curing the multilayer green tape at the high temperature of 170 ℃ for about 30 minutes to obtain the composite wave-absorbing material with the gradual change type structure, wherein the thickness of the composite wave-absorbing material is about 1000 microns. The thickness of the double-layer green tape can be controlled by adjusting the extrusion distance of the slit, so that the thickness of the final product, namely the multi-layer composite wave-absorbing material is controlled, and the scheme has good flexibility.
Example 2
The wave absorbing agent used in the embodiment is iron nitride and activated carbon fiber, the mass ratio of the iron nitride to the activated carbon fiber is 10:1, the curing temperature of the epoxy resin a is 130-180 ℃, the viscosity at 50 ℃ is 2000-8000 mPa & s, the curing temperature of the epoxy resin b is 170-200 ℃, and the viscosity at 50 ℃ is 20000-70000 mPa & s, the preparation method is as in embodiment 1, wherein the wave absorbing agent accounts for 10%, 25%, 40%, 55%, 70%, and 85% of the different wave absorbing layers respectively, the thickness of the single double-layer green belt is 150 μm, and the thickness of the multilayer composite wave absorbing material obtained after lamination and curing is about 700 μm, and can be flexibly adjusted according to actual requirements.
Example 3
The wave absorbing agent used in the embodiment is ferrosilicon aluminum powder and carbon nano tubes, the ratio of the ferrosilicon aluminum powder to the carbon nano tubes is 15:1, the curing temperature of the epoxy resin a is 130-180 ℃, the viscosity at 50 ℃ is 2000-8000 mPa & s, the curing temperature of the epoxy resin b is 170-200 ℃, and the viscosity at 50 ℃ is 20000-70000 mPa & s, the preparation method is prepared according to the preparation steps of the embodiment 1, wherein the wave absorbing agent accounts for 5%, 20%, 35%, 50%, 65% and 80% respectively in different wave absorbing layers, the thickness of a single double-layer green tape is 150 μm, and the thickness of the multilayer composite wave absorbing material obtained after lamination and curing is about 1100 μm, and the wave absorbing agent can be flexibly adjusted according to actual requirements.
Effect example 1
Example 4: embodiment 4 provides a composite wave-absorbing material, which includes a first wave-absorbing layer, an epoxy resin layer, and a second wave-absorbing layer, where the raw material of the first wave-absorbing layer is slurry P65 in embodiment 1, the raw material of the epoxy resin layer is slurry P0 in embodiment 1, and the raw material of the second wave-absorbing layer is slurry P85 in embodiment 1, and the slurries P65, P0, and P85 are respectively made into green sheets by a slit coating process, and are dried according to the temperature gradient of the oven in embodiment 1, and then are cured according to the hot-pressing-free lamination curing manner in embodiment 1.
Comparative example 1: comparative example 1 provides a wave-absorbing material, which is the same as example 4, except that the first wave-absorbing layer and the second wave-absorbing layer are directly subjected to hot-press-free lamination curing without using an epoxy resin layer formed by resin paste P0 of the intermediate layer.
Comparative example 2: comparative example 2 provides a wave-absorbing material, which is the same as example 4 except that the epoxy resin layer formed of resin paste P0 of the intermediate layer was not used, and the first and second wave-absorbing layers were directly subjected to thermocompression curing at 170 ℃ and a pressure of 0.2MPa (gauge pressure).
Comparative example 3: comparative example 3 provides a wave-absorbing material, which is the same as that in example 4, except that epoxy resin a (curing temperature of 130-180 ℃ and viscosity of 4500-5800 mPa · s at 50 ℃) is used in the slurry P0 of the epoxy resin layer, that is, the epoxy resin is the same as that used in the wave-absorbing layer.
When this application is tested in the initial stage, adopt the mode of comparative example 1 to prepare, when the experiment finds that wave-absorbing agent content is high, when the wave-absorbing layer is heating solidification, resin in first wave-absorbing layer and the second wave-absorbing layer takes place the thermosetting reaction respectively, does not cohere between the layer, can not bind between the wave-absorbing layer completely. Then the wave-absorbing material is prepared by adopting the mode of the comparative example 2, and the wave-absorbing material is characterized by adopting an optical microscope, and the result is shown in figure 4. Subsequently, the application adopts a mode of a comparative example 3, tries to add epoxy resin between the wave absorbing layers, and the epoxy resin adopted in the initial trial is the same as the epoxy resin in the wave absorbing agent layer, so that the casting film forming property of the epoxy resin is poor, the viscosity is low, the epoxy resin can be generally adhered to the two wave absorbing layers after being cured, but the epoxy resin is layered under the action of smaller external force (slight bending), and the adhesiveness is poor. Finally, according to the application, through adjusting an experimental scheme, epoxy resin of different types from the wave absorbing agent layer is introduced between the wave absorbing agent layers by adopting the mode of the embodiment 4, a curing agent is added, and the prepared composite wave absorbing material is characterized by adopting an optical microscope, and the result is shown in figure 5. Subsequently, the application continues to test, researches show that epoxy resin with the curing temperature of 170-200 ℃ and the viscosity of 20000-70000 mPa & s at 50 ℃ is selected as the intermediate layer, the curing agent is introduced, the bonding effect is shown in figure 5, and no delamination is found after the prepared material is characterized by an optical microscope.
Claims (10)
1. The composite wave-absorbing material is characterized by comprising:
the wave absorbing layers comprise a wave absorbing agent and first epoxy resin, and the curing temperature of the first epoxy resin is 130-180 ℃, and the viscosity of the first epoxy resin at 50 ℃ is 2000-8000 mPa & s;
the epoxy resin layer is arranged among the wave absorbing layers and comprises second epoxy resin and a curing agent, the curing temperature of the second epoxy resin is 170-200 ℃, and the viscosity of the second epoxy resin at 50 ℃ is 20000-70000 mPa & s.
2. The composite wave-absorbing material of claim 1, wherein the mass fraction of the wave-absorbing agent in the plurality of wave-absorbing layers is gradually increased or decreased along the thickness direction of the composite wave-absorbing material.
3. The composite wave-absorbing material of claim 1, wherein the wave-absorbing agent comprises at least two of iron nitride, hydroxyl iron powder, iron-silicon-aluminum powder, activated carbon fiber, carbon nanotube, and hollow glass microsphere.
4. The composite wave-absorbing material according to any one of claims 1 to 3, wherein the curing agent is methyl tetrahydrophthalic anhydride or dicyandiamide.
5. The composite wave-absorbing material according to any one of claims 1 to 3, wherein the mass ratio of the curing agent to the second epoxy resin in the epoxy resin layer is 1: (1.5 to 3).
6. The composite wave-absorbing material according to any one of claims 1 to 3, wherein the wave-absorbing layer further comprises an organic solvent, and the organic solvent is at least two of ethyl acetate, N, N-dimethylformamide, absolute ethyl alcohol and acetone.
7. A preparation method of the composite wave-absorbing material of any one of claims 1 to 6, characterized by comprising the following steps:
(1) taking the raw materials of the wave absorbing layer and the epoxy resin layer, and preparing and forming a plurality of double-layer green sheets by using a double-layer slit coating process;
(2) and overlapping a plurality of double-layer green sheets, and heating and curing to obtain the composite wave-absorbing material.
8. The method for preparing the composite wave-absorbing material according to claim 7, further comprising drying the double-layer green sheets before stacking, wherein the temperature of the drying is increased from 30-40 ℃ to 90-100 ℃, and then is cooled to 25-35 ℃.
9. The preparation method of the composite wave-absorbing material according to claim 7, wherein the raw materials of the wave-absorbing layer or the epoxy resin layer in the step (1) are processed by a ball milling method, the ball milling speed is 200-400 r/min, and the ball milling time is 2-12 hours.
10. The preparation method of the composite wave-absorbing material according to claim 7, wherein the double-layer slit coating process is characterized in that the pitch of the first slits is 20-40 μm, and the pitch of the second slits is 200-300 μm.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114213995A (en) * | 2021-12-14 | 2022-03-22 | 武汉康泰威新材料技术有限公司 | Multi-frequency wave-absorbing patch for offshore wind power project and preparation method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103261262A (en) * | 2010-10-22 | 2013-08-21 | 新日铁住金化学株式会社 | High-molecular-eight epoxy resin and resin film, resin composition, and cured article using high-molecular-weight epoxy resin |
-
2020
- 2020-09-21 CN CN202010993334.9A patent/CN112208183A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103261262A (en) * | 2010-10-22 | 2013-08-21 | 新日铁住金化学株式会社 | High-molecular-eight epoxy resin and resin film, resin composition, and cured article using high-molecular-weight epoxy resin |
Non-Patent Citations (2)
| Title |
|---|
| 胡明宇等: "流延法制备铁基吸波电磁厚膜的工艺和吸波性能研究", 《电子元件与材料》 * |
| 陈伟鹏等: "碳纤维膜多层复合结构吸波体的宽化设计与制备", 《功能材料》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114213995A (en) * | 2021-12-14 | 2022-03-22 | 武汉康泰威新材料技术有限公司 | Multi-frequency wave-absorbing patch for offshore wind power project and preparation method |
| CN114213995B (en) * | 2021-12-14 | 2023-05-23 | 武汉康泰威新材料技术有限公司 | Multi-frequency wave-absorbing patch for offshore wind power project and preparation method |
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