Wave-absorbing patch material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of wave-absorbing materials, and provides a wave-absorbing patch material as well as a preparation method and application thereof. The wave-absorbing patch material comprises the following raw materials in parts by weight: 100 parts of chloroprene rubber, 20-30 parts of polycrystalline iron fibers, 5-8 parts of a vulcanizing agent, 0.5-1 part of an accelerant and 3-5 parts of an anti-aging agent, the polycrystalline iron fibers are composite polycrystalline iron fibers of an aminochloropyrimidinethione compound, and the aminochloropyrimidinethione compound comprises 5-amino-6-chloro-1H-pyrimidine-4-thioketone. According to the technical scheme, the problem of high reflectivity of the wave-absorbing patch material in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave absorbing materials, and specifically, to a microwave absorbing patch material, a preparation method thereof, and an application thereof. Background Art

[0002] A microwave absorbing patch material is a type of functional material that can absorb and attenuate incident electromagnetic waves and convert electromagnetic energy into thermal energy or other forms of energy for dissipation. It is usually composed of a matrix material and a microwave absorber. By reasonably designing the composition and structure of the material, efficient absorption of electromagnetic waves in a specific frequency band can be achieved, and it is widely used in fields such as electronic information, medical health, and aerospace.

[0003] However, at present, the absorption efficiency of some microwave absorbing patch materials for electromagnetic waves is not ideal, resulting in a high reflectivity. This means that a relatively large amount of electromagnetic waves are still reflected back, which not only fails to effectively reduce the electromagnetic signal characteristics of the target object but may also generate additional electromagnetic interference to the surrounding environment. For example, in the aerospace field, in a busy air traffic environment, civil airliners rely on accurate radar monitoring for air traffic control. If the reflectivity of the microwave absorbing patch material on the surface of the airliner is high, it will cause abnormal signals on the radar screen, confusing with normal signals. The air traffic control radar may misjudge the abnormal signals generated by the high reflectivity as other aircraft or obstacles, resulting in incorrect control instructions and increasing the risk of collisions between flights, seriously threatening flight safety. Therefore, it is necessary to develop a microwave absorbing patch material with a low reflectivity. Summary of the Invention

[0004] The present invention provides a microwave absorbing patch material, a preparation method thereof, and an application thereof, which solve the problem of high reflectivity of microwave absorbing patch materials in related technologies.

[0005] The technical solution of the present invention is as follows: The present invention provides a microwave absorbing patch material, which comprises the following raw materials in parts by weight: 100 parts of chloroprene rubber, 20 - 30 parts of polycrystalline iron fibers, 5 - 8 parts of vulcanizing agent, 0.5 - 1 part of accelerator, and 3 - 5 parts of antioxidant. The polycrystalline iron fibers are polycrystalline iron fibers compounded with an aminochloropyrimidine thione compound, and the aminochloropyrimidine thione compound comprises 5 - amino - 6 - chloro - 1H - pyrimidine - 4 - thione.

[0006] As a further technical solution, the preparation method of the polycrystalline iron fibers compounded with an aminochloropyrimidine thione compound comprises the following steps: dispersing the aminochloropyrimidine thione compound in a solvent, adding polycrystalline iron fibers and a dispersant, and after reaction, filtering and drying to obtain the polycrystalline iron fibers compounded with an aminochloropyrimidine thione compound.

[0007] As a further technical solution, the reaction time is 2h.

[0008] As a further technical solution, the dispersant is polyvinylpyrrolidone.

[0009] As a further technical solution, the mass ratio of the dispersant to the polycrystalline iron fiber is 1:30.

[0010] In the present invention, during the preparation of the aminochloropyrimidine thione compound composite polycrystalline iron fiber, polyvinylpyrrolidone is added as a dispersant to promote the uniform dispersion of the polycrystalline iron fiber, enabling the subsequent reaction with the aminochloropyrimidine thione compound to be more sufficient and uniform, and ensuring the consistency and stability of the final composite product.

[0011] As a further technical solution, the raw materials of the aminochloropyrimidine thione compound composite polycrystalline iron fiber include the aminochloropyrimidine thione compound and the polycrystalline iron fiber with a mass ratio of 1-2:15.

[0012] As a further technical solution, the chloroprene rubber is composed of a first chloroprene rubber and a second chloroprene rubber, and the crystallization rates of the first chloroprene rubber and the second chloroprene rubber are different.

[0013] In an aircraft, the wave-absorbing material is often applied to structural components such as wings and fuselages. During flight, the aircraft has to withstand powerful external forces such as air pressure, gravity, and engine vibration. If the mechanical strength of the wave-absorbing material is insufficient, it is prone to breakage and shedding, damaging the aerodynamic shape of the aircraft, increasing flight resistance, and even endangering flight safety. In the present invention, the first chloroprene rubber and the second chloroprene rubber with different crystallization rates are added as raw materials. The quickly crystallizing chloroprene rubber forms more crystallization regions in a shorter time, tightly connecting the molecular chains together, significantly improving the overall strength of the material. The slowly crystallizing chloroprene rubber has more time for regular arrangement during the material forming process, forming a relatively large and complete crystal structure, enabling the material to absorb energy through the slip and rearrangement of molecular chains when stressed, avoiding the generation and rapid propagation of cracks due to stress concentration, and enhancing the mechanical strength of the wave-absorbing patch material; As a further technical solution, the crystallization rate of the first chloroprene rubber > the crystallization rate of the second chloroprene rubber, and the mass ratio of the first chloroprene rubber to the second chloroprene rubber is 3:1-2.

[0014] In the present invention, by reasonably adjusting the mass ratio of the first chloroprene rubber and the second chloroprene rubber, the synergistic effect of the two is exerted to enhance the mechanical strength of the wave-absorbing patch material.

[0015] As a further technical solution, the vulcanizing agent includes one or two of zinc oxide and magnesium oxide.

[0016] In the present invention, a vulcanizing agent is added to promote the process of vulcanization reaction and facilitate the formation of a crosslinked network. The crosslinked network structure endows the rubber material with better elasticity and stability, enabling the microwave absorbing patch material to maintain a specific shape and performance.

[0017] As a further technical solution, the accelerator includes one or more of accelerator NA-22, accelerator TMTD, and accelerator TMTM.

[0018] As a further technical solution, the accelerator is preferably accelerator NA-22.

[0019] In the present invention, an accelerator is added to further accelerate the vulcanization reaction, increase the crosslinking speed, facilitate the formation of a more uniform and perfect crosslinked structure, stabilize the vulcanization reaction process, and reduce the change in product quality caused by fluctuations in factors such as vulcanization time and temperature.

[0020] As a further technical solution, the antioxidant includes one or both of antioxidant 4010NA and antioxidant 4020.

[0021] In the present invention, an antioxidant is added. High temperature and oxygen can cause the rubber molecular chains to break, generate free radicals, and then trigger a chain reaction, resulting in a decline in material performance. The addition of the antioxidant can slow down the deterioration rate of the material performance and extend the service life of the material.

[0022] The present invention also provides a preparation method for a microwave absorbing patch material, comprising the following steps: S1. Weigh the remaining raw materials except the accelerator, mix them evenly to obtain a slurry; S2. Add the accelerator to the slurry, mix and knead, and then vulcanize to obtain the microwave absorbing patch material.

[0023] As a further technical solution, the mixing time in S1 is 45 - 60 min.

[0024] As a further technical solution, the mixing and kneading time in S2 is 5 - 10 min.

[0025] The present invention also provides an application of the microwave absorbing patch material or the microwave absorbing patch material obtained by the preparation method in the field of anti-radar interference.

[0026] The working principle and beneficial effects of the present invention are as follows: In the present invention, using chloroprene rubber as the raw material, polycrystalline iron fibers as the wave-absorbing material, adding vulcanizing agents, accelerators and anti-aging agents, a wave-absorbing patch material is prepared. Chloroprene rubber itself has certain flexibility and dielectric properties, providing good matrix support for the wave-absorbing material. The reasonable dosages of vulcanizing agents, accelerators and anti-aging agents ensure good processing properties and physical and mechanical properties of the material, making the material more stable during the forming process, and having good durability and anti-aging ability, extending the service life of the wave-absorbing patch material and broadening its application range under different environmental conditions. Using polycrystalline iron fibers as the wave-absorbing material, it has good magnetic permeability and magnetic loss characteristics, and can produce a strong magnetic loss effect on electromagnetic waves. After compounding with an aminochloropyrimidine thione compound, the surface electronic structure and electromagnetic characteristics of the polycrystalline iron fibers are changed, making it achieve a better match with the chloroprene rubber matrix and other components in electromagnetic properties. This synergistic effect greatly enhances the electromagnetic wave absorption ability of the wave-absorbing patch material and effectively reduces the reflectivity of the wave-absorbing patch material. Specific Embodiments

[0027] The following will describe clearly and completely the technical solutions in the embodiments of the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the scope of protection of the present invention.

[0028] In the following examples and comparative examples: Polycrystalline iron fibers: with a diameter of 5 - 10 μm and an aspect ratio ≥ 500; The first chloroprene rubber: fast-crystallizing chloroprene rubber, model G-40S-1; The second chloroprene rubber: slow-crystallizing chloroprene rubber, model S-40; Polyvinylpyrrolidone: with an average molecular weight of 58000, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0029] Example 1 The preparation method of the aminochloropyrimidine thione compound composite polycrystalline iron fibers includes the following steps: Disperse 2 parts of 5-amino-6-chloro-1H-pyrimidine-4-thione in 300 parts of dimethyl sulfoxide, add 30 parts of polycrystalline iron fibers and 1 part of polyvinylpyrrolidone, and after reacting for 2 h, filter and dry to obtain the aminochloropyrimidine thione compound composite polycrystalline iron fibers; A preparation method of a wave-absorbing patch material includes the following steps: S1. Weigh 100 parts of chloroprene rubber, 5 parts of zinc oxide, 20 parts of polycrystalline iron fibers, and 3 parts of antioxidant 4010NA. After mixing for 45 minutes, mix evenly to obtain a slurry. Among them, the chloroprene rubber is the first chloroprene rubber, and the polycrystalline iron fibers are amino-chloropyrimidine thione compound composite polycrystalline iron fibers obtained by the above preparation method; S2. Add 0.5 part of accelerator NA-22 to the slurry, mix for 5 minutes, and then vulcanize to obtain the wave-absorbing patch material.

[0030] Example 2 The preparation method of amino-chloropyrimidine thione compound composite polycrystalline iron fibers includes the following steps: Disperse 2 parts of 5-amino-6-chloro-1H-pyrimidine-4-thione in 300 parts of dimethyl sulfoxide, add 30 parts of polycrystalline iron fibers and 1 part of polyvinylpyrrolidone, and after reacting for 2 hours, filter and dry to obtain amino-chloropyrimidine thione compound composite polycrystalline iron fibers; A preparation method of a wave-absorbing patch material includes the following steps: S1. Weigh 100 parts of chloroprene rubber, 6 parts of zinc oxide, 25 parts of polycrystalline iron fibers, and 4 parts of antioxidant 4010NA. After mixing for 55 minutes, mix evenly to obtain a slurry. Among them, the chloroprene rubber is the first chloroprene rubber, and the polycrystalline iron fibers are amino-chloropyrimidine thione compound composite polycrystalline iron fibers obtained by the above preparation method; S2. Add 0.8 part of accelerator NA-22 to the slurry, mix for 8 minutes, and then vulcanize to obtain the wave-absorbing patch material.

[0031] Example 3 The preparation method of amino-chloropyrimidine thione compound composite polycrystalline iron fibers includes the following steps: Disperse 2 parts of 5-amino-6-chloro-1H-pyrimidine-4-thione in 300 parts of dimethyl sulfoxide, add 30 parts of polycrystalline iron fibers and 1 part of polyvinylpyrrolidone, and after reacting for 2 hours, filter and dry to obtain amino-chloropyrimidine thione compound composite polycrystalline iron fibers; A preparation method of a wave-absorbing patch material includes the following steps: S1. Weigh 100 parts of chloroprene rubber, 8 parts of magnesium oxide, 30 parts of polycrystalline iron fibers, and 5 parts of antioxidant 4020. After mixing for 60 minutes, mix evenly to obtain a slurry. Among them, the chloroprene rubber is the first chloroprene rubber, and the polycrystalline iron fibers are amino-chloropyrimidine thione compound composite polycrystalline iron fibers obtained by the above preparation method; S2. Add 1 part of accelerator NA-22 to the slurry, mix for 10 minutes, and then vulcanize to obtain the wave-absorbing patch material.

[0032] Example 4 Compared with Example 1, the difference in Example 4 is that the addition amount of 5-amino-6-chloro-1H-pyrimidine-4-thione is 3 parts.

[0033] Example 5 Compared with Example 1, the difference in Example 5 is that the chloroprene rubber is the second chloroprene rubber.

[0034] Example 6 Compared with Example 1, the difference in Example 6 is that the chloroprene rubber is composed of the first chloroprene rubber and the second chloroprene rubber with a mass ratio of 3:1.

[0035] Example 7 Compared with Example 1, the difference in Example 7 is that the chloroprene rubber is composed of the first chloroprene rubber and the second chloroprene rubber with a mass ratio of 3:2.

[0036] Comparative Example 1 Compared with Example 1, the difference in Comparative Example 1 is that the aminochloropyrimidine thione compound - composite polycrystalline iron fiber is replaced with an equal amount of polycrystalline iron fiber.

[0037] Experimental Example 1 For the radar - absorbing patch materials prepared in Examples 1 - 4 and Comparative Example 1, according to the test method specified in GJB 2038A - 2011 "Test Method for Reflectivity of Radar - Absorbing Materials", the reflectivity of the samples was tested. The test method was the bow - tie test method, and the test frequency was 8 - 18 GHz.

[0038] The test results are shown in Table 1: Table 1 Performance test results of the radar - absorbing patch materials prepared in Examples 1 - 4 and Comparative Example 1

[0039] Compared with Comparative Example 1, the reflectivities of Examples 1 - 4 are all less than that of Comparative Example 1, indicating that when adding the aminochloropyrimidine thione compound - composite polycrystalline iron fiber, the reflectivity of the radar - absorbing patch material can be reduced.

[0040] Experimental Example 2 For the radar - absorbing patch materials prepared in Example 1 and Examples 5 - 7, according to the test method specified in GB / T 528 - 2009 "Determination of Tensile Stress - Strain Properties of Vulcanized Rubber or Thermoplastic Rubber", the tensile strength of the samples was tested. The specimen was dumbbell - shaped type I, and the tensile rate was 500 mm / min.

[0041] The test results are shown in Table 2: Table 2 Performance test results of the radar - absorbing patch materials prepared in Example 1 and Examples 5 - 7

[0042] Compared with Examples 1 and 5, the tensile strength of Examples 6 and 7 is higher than that of Examples 1 and 5, indicating that the first chloroprene rubber and the second chloroprene rubber play a synergistic role and can improve the mechanical properties of the microwave absorbing patch material.

[0043] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A microwave absorbing patch material, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of chloroprene rubber, 20-30 parts of polycrystalline iron fiber, 5-8 parts of vulcanizing agent, 0.5-1 part of accelerator and 3-5 parts of antioxidant. The polycrystalline iron fiber is an aminochloropyrimidinethione compound composite polycrystalline iron fiber, and the aminochloropyrimidinethione compound comprises 5-amino-6-chloro-1H-pyrimidine-4-thione.

2. The absorbing patch material according to claim 1, characterized in that: The preparation method of the aminochloropyrimidinethione compound composite polycrystalline iron fiber comprises the following steps: dispersing the aminochloropyrimidinethione compound in a solvent, adding polycrystalline iron fiber and a dispersant, filtering and drying after reaction, so as to obtain the aminochloropyrimidinethione compound composite polycrystalline iron fiber.

3. The absorbing patch material according to claim 2, characterized in that: The dispersant is polyvinyl pyrrolidone.

4. The absorbing patch material according to claim 1, characterized in that: The raw materials of the aminochloropyrimidinethione compound composite polycrystalline iron fiber include aminochloropyrimidinethione compound and polycrystalline iron fiber in a mass ratio of 1 to 2:

15.

5. The absorbing patch material according to claim 1, characterized in that: The chloroprene rubber consists of a first chloroprene rubber and a second chloroprene rubber, and the first chloroprene rubber and the second chloroprene rubber have different crystallization rates.

6. The absorbing patch material according to claim 5, characterized in that: The crystallization rate of the first chloroprene rubber is greater than the crystallization rate of the second chloroprene rubber, and the mass ratio of the first chloroprene rubber to the second chloroprene rubber is 3:1-2.

7. The microwave absorbing patch material according to claim 1, characterized in that: The vulcanizing agent includes one or both of zinc oxide and magnesium oxide.

8. The absorbing patch material according to claim 1, characterized in that: It also includes at least one of the following technical features: The accelerator includes one or more of accelerator NA-22, accelerator TMTD, and accelerator TMTM; The antioxidant includes one or both of antioxidant 4010NA and antioxidant 4020.

9. The method for preparing an absorbing patch material according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Weigh the remaining raw materials except the accelerator, mix them evenly, and obtain a slurry; S2. Add an accelerator to the slurry, mix and vulcanize it to obtain the absorbing patch material.

10. Use of the absorbing patch material according to any one of claims 1 to 8 or the absorbing patch material obtained by the preparation method according to claim 9 in the field of anti-radar interference.

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