Wave-transparent prepreg, method for preparing the same, and use thereof

Abstract

The present application relates to the field of prepreg, in particular to a wave-transparent prepreg, a preparation method and application thereof, the wave-transparent prepreg comprises a quartz fiber cloth and a polyimide resin loaded on the quartz fiber cloth; 100-400 g of the polyimide resin is compounded per square meter of the quartz fiber cloth.The present application compounds the polyimide resin on the quartz fiber cloth, and the grammage of the polyimide resin and the quartz fiber cloth is screened, the obtained wave-transparent prepreg has good physical properties, has high strength and modulus in aspects of tensile, compression, bending, interlaminar shear and the like, and the wave-transparent prepreg has excellent wave-transparent performance, the dielectric constant is between 3.25-3.45, and the dielectric loss is as low as 0.002.

Description

Technical Field

[0001] This invention relates to the field of prepregs, and more specifically, to microwave-transparent prepregs, their preparation methods, and applications. Background Technology

[0002] Wave-transparent prepregs are widely used in aviation, aerospace, electronic warfare, and radar stealth fields. Their performance directly affects the electromagnetic wave absorption capacity, structural strength, and service life of equipment. Wave-transparent prepregs are typically composed of reinforcing fibers and matrix resin. The resin is uniformly impregnated into the fibers through an impregnation process, followed by curing to obtain stable electromagnetic properties.

[0003] However, the currently mainstream wet impregnation prepreg preparation process faces the prominent problem of poor resin distribution uniformity, resulting in numerous air bubbles, voids, and localized resin-rich or resin-poor areas within the material. These defects not only weaken the mechanical properties of the prepreg but also lead to unstable microwave transmission performance in microwave-transparent prepregs. Furthermore, the interfacial bonding strength between the resin and fiber in existing processes is insufficient, making it prone to interlayer delamination or performance degradation at high temperatures, thus failing to meet the application requirements of high temperature resistance, high microwave transmission, and high product stability.

[0004] Based on this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a high-temperature resistant, high-transmittance, and highly stable translucent prepreg, as well as its preparation method and application.

[0006] This invention is implemented as follows: In a first aspect, the present invention provides a microwave-transparent prepreg comprising a quartz fiber cloth and a polyimide resin loaded on the quartz fiber cloth; Each square meter of the quartz fiber cloth is compounded with 100-400 g of the polyimide resin.

[0007] In an optional embodiment, the basis weight of the quartz fiber cloth is 100~400 g / m².

[0008] In an optional embodiment, the polyimide resin is selected from at least one of ZTS-350, SQPI-04, and FRPI-4216.

[0009] Secondly, the present invention provides a method for preparing the above-mentioned microwave-transparent prepreg, comprising the following steps: The polyimide resin is made into a film; The adhesive film is pressed onto the opposite sides of the quartz fiber cloth to obtain the microwave-transparent prepreg.

[0010] In an optional embodiment, the thickness of the adhesive film is 0.10~0.12 mm.

[0011] In an optional embodiment, the polyimide resin is formed into a film using a coating machine, wherein the roller temperature of the coating machine is 40~80°C.

[0012] In an optional embodiment, a laminating machine is used to press the membrane-like microwave absorbing material onto the opposite sides of the quartz fiber cloth, and the temperature of the heating roller is 60~90°C.

[0013] In an optional embodiment, the thickness of the microwave-transparent prepreg is 0.23~0.26 mm.

[0014] In an optional embodiment, the dielectric constant of the microwave-transparent prepreg is <3.5.

[0015] In an optional embodiment, the glass transition temperature of the microwave-transparent prepreg is >400°C.

[0016] Thirdly, the present invention provides the application of the above-mentioned microwave-transparent prepreg or the microwave-transparent prepreg prepared by the above-mentioned preparation method in the preparation of microwave-transparent composite materials and / or microwave-absorbing composite materials.

[0017] Fourthly, the present invention provides a wave-transparent composite material, including the wave-transparent prepreg described above.

[0018] The present invention has the following beneficial effects: This invention obtains a microwave-transparent prepreg by composited polyimide resin onto quartz fiber cloth and screening the basis weight of the polyimide resin and quartz fiber cloth. The prepreg has good physical properties, with high strength and modulus in tensile, compression, bending and interlaminar shear, and excellent microwave transmission performance. The dielectric constant is between 3.25 and 3.45 and the dielectric loss is as low as 0.002. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the coating machine.

[0021] Figure 2 This is a schematic diagram of the composite machine. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0023] A specific embodiment of the present invention provides a microwave-transparent prepreg, comprising a quartz fiber cloth and a polyimide resin loaded on the quartz fiber cloth; Each square meter of quartz fiber cloth is composited with 100~400 g of polyimide resin.

[0024] Quartz fiber possesses extremely low dielectric constant (approximately 3.0~3.7) and dielectric loss, and its long-term operating temperature can reach 1050℃~1200℃. Polyimide resin, on the other hand, exhibits good thermal stability (glass transition temperature exceeding 350℃) and excellent dielectric properties, ensuring that the material maintains extremely low signal loss even at high temperatures. The prepreg obtained by combining quartz fiber and polyimide in this invention possesses good physical properties, exhibiting high strength in tensile, compressive, bending, and interlaminar shear resistance. Its glass transition temperature reaches 400~440℃, its dielectric constant is between 3.25 and 3.45, and its dielectric loss is as low as 0.002. Therefore, the microwave-transparent prepreg provided in this application has the characteristics of high temperature resistance and high microwave transparency compared to existing technologies.

[0025] Optionally, the weight of the quartz fiber cloth is 100~400 g / m².

[0026] Optionally, the polyimide resin is selected from at least one of ZTS-350, SQPI-04, and FRPI-4216.

[0027] The present invention also provides a method for preparing the above-mentioned microwave-transparent prepreg, comprising the following steps: Polyimide resin is made into a film; The adhesive film is pressed onto the opposite sides of the quartz fiber cloth to obtain a microwave-transparent prepreg.

[0028] Specifically, the preparation method is as follows: Ambient temperature and humidity requirements: (23±3)℃, RH≤65%; S1: Coating The equipment is a coating machine, such as Figure 1 As shown; Heating and heat preservation: the temperature of the comma roller is (40~80)℃, the temperature of the C roller is (40~80)℃, the temperature of the large heating plate is (40~80)℃, and after reaching the specified temperature, heat preservation is carried out for (60~120) min. Calibrate the gap; the gap between the C roller and the comma roller is (0.10~0.11) mm. For the resin to be melted and paper-threaded, the resin is divided into small pieces and placed on a large heating plate to melt the resin. The melting time is (30~120) min. Release paper is then threaded and PE film is pasted on the equipment. Start the equipment with the overall machine speed at (8~15) m / min, B roller speed at (80~120)%, C roller speed ratio at (80~120)%, unwinding tension at (280~320) N, and winding tension at (130~160) N. The coating process is completed to obtain a film with a thickness of 0.10~0.12 mm.

[0029] S2: Composite The equipment is a composite machine, such as Figure 2 As shown; Heating and heat preservation: the temperature of the coating roller is (25~40)℃, the temperature of the No. 3 heating roller is (60~90)℃, the temperature of the No. 2 heating roller is (60~90)℃, the temperature of the No. 1 heating roller is (60~90)℃, and after reaching the specified temperature, heat preservation is carried out for (60~120) min. Calibrate the gaps; adjust the gaps between heating rollers #1, #2, and #3 to (0.3~0.6) mm. Threading and splicing: The two prepared rolls of adhesive film are fed onto the machine, and release paper is threaded through them. Start the equipment. The overall speed is (2~6) m / min. The winding tension is (200~240) N for the top adhesive film and (200~240) N for the bottom adhesive film. The winding tension is (150~190) N for the finished product, (150~190) N for the top paper, (50~90) N for the top PE film, and (50~90) N for the bottom PE film. The composite process yields a microwave-transparent prepreg.

[0030] In an optional embodiment, the thickness of the obtained microwave-transparent prepreg is 0.23-0.26 mm.

[0031] In an optional embodiment, the dielectric constant of the resulting microwave-transparent prepreg is <3.5.

[0032] In an optional embodiment, the glass transition temperature of the resulting microwave-transparent prepreg is >400°C.

[0033] Thirdly, the present invention provides the application of the above-mentioned microwave-transparent prepreg or the microwave-transparent prepreg prepared by the above-mentioned preparation method in the preparation of microwave-transparent composite materials and / or microwave-absorbing composite materials.

[0034] Fourthly, the present invention also provides a wave-transparent composite material comprising the above-mentioned wave-transparent prepreg.

[0035] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0036] Example 1 The quartz fiber cloth used in this embodiment is of brand name FQWA-280S8-100HK-36*20, with a basis weight of 288g / m². 2 The polyimide resin used is grade SQPI-04.

[0037] The specific preparation method is as follows: S1: Coating The equipment is a coating machine, such as Figure 1 As shown; Heating and heat preservation: comma roller temperature 55℃, C roller temperature 55℃, large heating plate temperature 55℃, heat preservation for 60 minutes after reaching the specified temperature. Calibrate the gap; the gap between roller C and roller comma is 0.1 mm. For the resin melting and paper threading process, the resin is divided into small pieces and placed on a large heating plate for melting. The melting time is 30 minutes. Release paper is then threaded onto the equipment and PE film is pasted on. Start the equipment with the overall machine speed at 10m / min, B roller speed at 100%, C roller speed ratio at 100%, unwinding tension at 300N, and winding tension at 150N. The coating process is completed to obtain a film with a thickness of 0.10~0.12 mm.

[0038] S2: Composite The equipment is a composite machine, such as Figure 2 As shown; Heating and heat preservation: the temperature of the coating roller is 30℃, the temperature of heating roller #3 is 75℃, the temperature of heating roller #2 is 75℃, and the temperature of heating roller #1 is 70℃. After reaching the specified temperature, heat preservation is carried out for 60 minutes. The gaps were calibrated, and the gaps between the three sets of heating rollers (1#, 2#, and 3#) were adjusted to 0.49mm. Threading and splicing: The two prepared rolls of adhesive film are fed onto the machine, and release paper is threaded through them. Start the equipment with a total speed of 4m / min, and the winding tension is 240N for the top adhesive film and 220N for the bottom adhesive film. The winding tension is 170N for the finished product, 170N for the top paper, 70N for the top PE film, and 70N for the bottom PE film. The composite process yields a microwave-transparent prepreg.

[0039] The microwave-transparent prepreg prepared in this embodiment has a thickness of 0.24 mm and contains 240 g / m² of polyimide resin. 2 .

[0040] Comparative Example 1 The quartz fiber cloth used in this comparative example is FQWA-280S8-100HK-36*20, with a basis weight of 288 g / m. 2 The high-temperature epoxy resin used is grade JCXB-SZ-GH01.

[0041] The specific preparation method is as follows: S1: Coating The equipment is a coating machine, such as Figure 1 As shown; Heating and heat preservation: comma roller temperature 75℃, C roller temperature 75℃, large heating plate temperature 75℃, heat preservation for 60 minutes after reaching the specified temperature. Calibrate the gap; the gap between roller C and roller comma is 0.1mm. For the resin melting and paper threading process, the resin is divided into small pieces and placed on a large heating plate for melting. The melting time is 30 minutes. Release paper is then threaded onto the equipment and PE film is pasted on. Start the equipment with the overall machine speed at 10m / min, B roller speed at 100%, C roller speed ratio at 100%, unwinding tension at 300N, and winding tension at 150N. The coating process is completed to obtain a film with a thickness of 0.10~0.12 mm.

[0042] S2: Composite The equipment is a composite machine, such as Figure 2 As shown; Heating and heat preservation: the temperature of the coating roller is 30℃, the temperature of heating roller #3 is 80℃, the temperature of heating roller #2 is 80℃, and the temperature of heating roller #1 is 75℃. After reaching the specified temperature, heat preservation is carried out for 60 minutes. The gaps were calibrated, and the gaps between the three sets of heating rollers (1#, 2#, and 3#) were adjusted to 0.49mm. Threading and splicing: The two prepared rolls of adhesive film are fed onto the machine, and release paper is threaded through them. Start the equipment with a total speed of 4m / min, and the winding tension is 240N for the top adhesive film and 220N for the bottom adhesive film. The winding tension is 170N for the finished product, 170N for the top paper, 70N for the top PE film, and 70N for the bottom PE film. The composite process yields a microwave-transparent prepreg.

[0043] The microwave-transparent prepreg prepared in this comparative example has a thickness of 0.25 mm and contains 177 g / m² of high-temperature epoxy resin. 2 .

[0044] Performance testing The performance of the microwave-transparent prepregs prepared in Example 1 and Comparative Example 1 was tested. The performance of the microwave-transparent prepregs provided in each example and comparative example was tested, wherein: The tensile property test method is: ASTM D3039 The test method for compressive properties is: ASTM D6641 The test method for bending performance is: ASTM D7264 The test method for glass transition temperature is: ASTM D7028 The interlaminar shear strength is tested according to ASTM D2344. The method for testing dielectric constant is: GB / T 5597 The test method for dielectric loss is: GB / T 5597 The results are shown in Table 1.

[0045] Table 1

[0046] In summary, the present invention, by compounding polyimide resin with quartz fiber cloth and screening the compounding ratio, produces a microwave-transparent prepreg with excellent high-temperature resistance and microwave transmission properties.

Claims

1. A microwave-transparent prepreg, characterized in that, Includes quartz fiber cloth and polyimide resin loaded on the quartz fiber cloth; Each square meter of the quartz fiber cloth is compounded with 100-400 g of the polyimide resin.

2. The microwave-transparent prepreg according to claim 1, characterized in that, The weight of the quartz fiber cloth is 100~400 g / m².

3. The microwave-transparent prepreg according to claim 1, characterized in that, The polyimide resin is selected from at least one of ZTS-350, SQPI-04, and FRPI-4216.

4. The method for preparing the microwave-transparent prepreg as described in claim 1, characterized in that, Includes the following steps: The polyimide resin is made into a film; The adhesive film is pressed onto the opposite sides of the quartz fiber cloth to obtain the microwave-transparent prepreg.

5. The preparation method according to claim 4, characterized in that, The thickness of the adhesive film is 0.10~0.12 mm.

6. The preparation method according to claim 4, characterized in that, The thickness of the microwave-transparent prepreg is, Optionally, the dielectric constant of the microwave-transparent prepreg is <3.5; Optionally, the glass transition temperature of the microwave-transparent prepreg is >400°C.

7. The preparation method according to claim 4, characterized in that, The polyimide resin is made into a film using a coating machine, wherein the roller temperature of the coating machine is 40~80℃.

8. The preparation method according to claim 4, characterized in that, A laminating machine is used to press the adhesive film onto the two opposite sides of the quartz fiber cloth. The temperature of the heating roller of the laminating machine is 60~90℃.

9. The application of the microwave-transparent prepreg as described in any one of claims 1 to 3, or the preparation method as described in any one of claims 4 to 7, in the preparation of microwave-transparent composite materials and / or microwave-absorbing composite materials.

10. A composite material, characterized in that, Includes the microwave-transparent prepreg as described in any one of claims 1 to 3.

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