Composite film with electrostatic discharge function and preparation method thereof

Abstract

The application discloses a composite film with electrostatic discharge function and a preparation method thereof. The composite film is a multilayer film structure and is used for co-curing forming with a composite material component. The composite film comprises a peelable release paper layer, a glue layer used for bonding with the composite material component, an insulating isolation layer used for electrical isolation with the composite material component, a conductive connection layer arranged on a local area above the insulating isolation layer and used for establishing electrical connection, an electric field enhancement layer located above the conductive connection layer and used for regulating and enhancing electric field distribution, a discharge layer located above the electric field enhancement layer and comprising a high-temperature-resistant resin matrix and high-resistance discharge fibers, and a protection layer covering the discharge layer. The multilayer composite film structure can be co-cured and formed with the composite material component, the integration of the electrostatic discharge function is realized, the aerodynamic resistance and weight are significantly reduced, and the discharge efficiency and long-term reliability are improved.

Description

Technical Field

[0001] This invention relates to the field of electrostatic protection technology, and in particular to a composite film with electrostatic discharge function and its preparation method. Background Technology

[0002] During flight, aircraft accumulate static electricity (P-Static) due to friction with media such as rain, snow, ice crystals, and dust. If this static electricity cannot be effectively released, it may cause interference from corona discharge noise to airborne communication and navigation equipment, and in severe cases, affect flight safety; there is also a risk of ignition near the fuel system.

[0003] Traditional aircraft electrostatic dischargers (ESDs) typically employ exposed rod-like structures, which suffer from high aerodynamic drag, susceptibility to damage, and high maintenance costs. Patch-type ESD devices embed conductive structures into a non-conductive substrate and adhere to the aircraft surface, significantly reducing drag and the risk of damage. However, this device still requires prefabrication and secondary bonding, and there is still room for improvement in terms of surface adaptability, ease of installation, and long-term bonding reliability.

[0004] Electrospinning technology has been used to prepare multilayer thin film microstructures, where a polymer solution is drawn into a jet using a high-voltage electrostatic field to form a multilayer film. Although electrospinning provides a new approach to the preparation of multilayer films, existing electrostatic discharge thin film structures prepared using this technology have not yet been able to achieve co-curing with composite material components (such as aircraft composite components), still requiring secondary bonding, resulting in weak interfacial bonding and poor adaptability to curved surfaces. Furthermore, these films still have shortcomings in electric field distribution control, high-density integration of micro-discharge tips, and optimization of thickness and weight, making it difficult to simultaneously meet the requirements of low initial discharge voltage, high discharge stability, and the stringent lightweight requirements of aircraft. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a composite membrane with electrostatic discharge functionality and its preparation method. This invention achieves integrated electrostatic discharge functionality through a multilayer composite membrane structure that can be co-cured with composite material components, significantly reducing aerodynamic drag and weight while improving discharge efficiency and long-term reliability.

[0006] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution: This invention discloses a composite film with electrostatic discharge function, which is a multilayer thin film structure used for co-curing with composite material components; the composite film comprises, from the side to be pasted to the side exposed to air, the following components in sequence: Peelable release paper layer; Adhesive layer, used for bonding to composite material components; An insulating layer is provided for electrical isolation from the composite material component. A conductive connection layer is disposed in a local area above the insulating isolation layer for establishing an electrical connection; An electric field enhancement layer, located above the conductive connection layer, is used to regulate and enhance the electric field distribution; The discharge layer, located above the electric field enhancement layer, comprises a high-temperature resistant resin matrix and high-resistance discharge fibers, and its trailing edge is constructed with a serrated structure for concentrating the electric field. A protective layer covers the discharge layer.

[0007] Furthermore, the volume resistivity of the insulating layer is not less than 10. 14 Ω·cm is used to isolate the discharge layer from the composite material component, allowing static charge to be guided into the discharge path through the conductive connection layer.

[0008] Furthermore, the conductive connection layer is disposed in the leading edge region of the composite film, and its sheet resistance is not greater than 5Ω / □.

[0009] As a preferred embodiment of the present invention, the electric field enhancement layer is made of a high dielectric constant material, and its dielectric constant gradually increases from the leading edge region to the trailing edge serrated structure direction, with a dielectric constant range of 10 to 30.

[0010] As another preferred embodiment of the present invention, the electric field enhancement layer is made of an electrostrictive material or an electrovariant material, whose dielectric constant and / or microstructure can change automatically in response to the externally applied electric field strength, so that the composite film has adaptive discharge capability.

[0011] Furthermore, the electric field enhancement layer and the discharge layer have complementary rectangular toothed edges on the front side.

[0012] Furthermore, in the discharge layer, at least in the serrated structure region at its trailing edge, some of the high-resistance discharge fibers are arranged perpendicular to the edge of the serrated structure; the protective layer is locally thinned in the region corresponding to the serrated structure of the discharge layer, exposing the ends of the high-resistance discharge fibers, thereby forming a micro-discharge tip array.

[0013] Preferably, the adhesive layer is an acrylic pressure-sensitive adhesive layer, an epoxy resin film, or a bismaleimide film, and the bonding or curing temperature of the adhesive layer is matched with the molding process of the composite material component.

[0014] Furthermore, the total thickness of the composite membrane is no greater than 0.8 mm, and the areal density is no greater than 100 g / m³. 2 .

[0015] Another aspect of the present invention provides a method for preparing the composite film with electrostatic discharge function described above, comprising the following steps: S1: Provide release paper; S2: Form an adhesive layer on the release paper; S3: An insulating layer is formed on the adhesive layer; S4: A conductive connection layer is formed in a predetermined leading edge region on the upper surface of the insulating layer; S5: An electric field enhancement layer is formed by coating the insulating isolation layer and the conductive connection layer; S6: Form a discharge layer containing high-resistance discharge fibers and having a serrated structure at the trailing edge on the electric field enhancement layer; S7: A protective layer is coated on the discharge layer to form a protective layer, and local thinning is performed in the area corresponding to the sawtooth structure; S8: Wind up the film to obtain the composite film.

[0016] The beneficial effects of this invention are as follows: (1) Co-curing and integral molding can be achieved. The composite film in this invention can be directly co-cured with the composite material component during the manufacturing process, eliminating the need for secondary bonding, eliminating the risk of interface peeling, and is especially suitable for curved parts, improving construction efficiency and structural reliability; (2) It can achieve low starting discharge voltage and high efficiency discharge. The sawtooth structure at the trailing edge of the discharge layer in this invention concentrates the electric field, and together with the high-resistance discharge fiber, it forms a discharge channel, which significantly reduces the corona discharge threshold and ensures rapid and stable release of static charge.

[0017] (3) Active electric field control can be achieved: The electric field enhancement layer in this invention is located below the discharge layer, which can optimize the surface electric field distribution, guide the charge to concentrate in the sawtooth region, and enhance the discharge efficiency.

[0018] (4) Achieving electrical isolation safety: The insulating isolation layer isolates the discharge layer from the composite material components. Static charge enters the discharge path only through the conductive connection layer, avoiding charge from entering the body structure and eliminating the risk of ignition near the fuel system.

[0019] (5) Minimal aerodynamic and weight loss: The overall film structure is thin and has low surface density. After attachment, it hardly changes the aerodynamic shape and the added weight is negligible.

[0020] (6) The protective layer and release paper layer facilitate construction: the release paper layer can protect the adhesive layer and facilitate storage and application; the protective layer covers the discharge layer, with only the serrated area exposed or the micro-tip retained, taking into account both environmental aging resistance and discharge function. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the cross-sectional structure of the composite membrane with electrostatic discharge function of the present invention in the width direction.

[0022] Figure 2This is a schematic diagram of the conductive connection layer in the composite film with electrostatic discharge function of the present invention.

[0023] Figure 3 This is a schematic diagram of the electric field enhancement layer in the composite film with electrostatic discharge function of the present invention.

[0024] Figure 4 This is a schematic diagram of the discharge layer in the composite film with electrostatic discharge function of the present invention.

[0025] In the diagram, 10: release paper layer; 20: adhesive layer; 30: insulating layer; 40: conductive connection layer; 50: electric field enhancement layer; 60: discharge layer; 70: protective layer. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] The present invention aims to provide a composite membrane with electrostatic discharge function and its preparation method, so as to solve the problems of high aerodynamic resistance, poor reliability of secondary bonding construction and insufficient adaptability to curved surfaces in existing electrostatic discharge devices.

[0028] The composite film with electrostatic discharge function provided by this invention is a multilayer thin film structure, used for co-curing with composite material components (e.g., aircraft composite material components: carbon fiber reinforced resin matrix composite wings, vertical tails, rotor blades, etc.). Figure 1 As shown, the composite film, from the side to be pasted (i.e. the side closest to the composite material component) to the side exposed to air, includes: a peelable release paper layer 10, an adhesive layer 20, an insulating isolation layer 30, a conductive connection layer 40, an electric field enhancement layer 50, a discharge layer 60, and a protective layer 70.

[0029] For example, the main functions and thickness ranges of each layer are as follows: the thickness of the release paper layer 10 is 50-100 μm, the thickness of the adhesive layer 20 is 20-40 μm, the thickness of the insulating isolation layer 30 is 50-100 μm, the thickness of the conductive connection layer 40 is 10-20 μm, the thickness of the electric field enhancement layer 50 is 20-50 μm, the thickness of the discharge layer 60 is 100-300 μm, and the thickness of the protective layer 70 is 10-30 μm.

[0030] Release paper layer 10 is located at the bottom and serves as a protective layer before construction. Its main function is to protect the second adhesive layer 20 during storage, transportation, and cutting, preventing the adhesive layer 20 from being contaminated or adhering to other materials. In the integrated molding process of composite materials, the operator peels off the release paper layer 10 before application, exposing the adhesive layer 20, and then applies the composite film to the surface of the uncured prepreg of the composite material component. Exemplarily, the release paper layer 10 can be made of PET release film or fluorinated release paper, with a release force preferably of 5–15 g / 25 mm and a temperature resistance of not less than 180°C to match the curing process of the composite material.

[0031] Adhesive layer 20 is used for bonding to the composite material component. Exemplarily, adhesive layer 20 can be an acrylic pressure-sensitive adhesive layer, an epoxy resin film, or a bismaleimide film. Preferably, the bonding or curing temperature of adhesive layer 20 is matched to the molding process of the composite material component, so that during co-curing, adhesive layer 20 undergoes a cross-linking reaction with the composite matrix to form a chemical bond. The room temperature peel strength of adhesive layer 20 is preferably not less than 6.0 kN / m, and the temperature resistance range is -55℃ to +180℃.

[0032] The insulating layer 30 serves to electrically isolate the composite material component. Exemplarily, the insulating layer 30 may be made of materials such as polyimide film or glass fiber reinforced polyimide. Preferably, the volume resistivity of the insulating layer 30 is not less than 10 Ω·cm. 14 The dielectric strength is not less than 150 kV / mm and the dielectric strength is Ω·cm. Its core function is to electrically isolate the discharge layer 60 from the composite material components (especially conductive carbon fiber composite materials), forcing static charges to enter the discharge path only through the conductive connection layer 40, and preventing charges from entering the body structure.

[0033] A conductive connection layer 40 is disposed in a localized area above the insulating isolation layer 30 to establish an electrical connection. Exemplarily, the conductive connection layer 40 is disposed at the leading edge region of the composite film, covering an area of ​​approximately 15% of the total area of ​​the composite film, and the width of the leading edge region is preferably 10–20 mm. The conductive connection layer 40 can be made of conductive fabric (such as nickel-plated carbon cloth), a conductive coating, or screen-printed conductive silver paste. Its sheet resistance is preferably not greater than 5 Ω / □ to provide a low-impedance discharge path.

[0034] An electric field enhancement layer 50 is located above the conductive connection layer 40 and is used to modulate and enhance the electric field distribution. Exemplarily, the electric field enhancement layer 50 is made of a high dielectric constant material with a dielectric constant ranging from 10 to 30. Preferably, its dielectric constant gradually increases from the leading edge region towards the trailing edge serrated structure, for example, the dielectric constant of the leading edge region is approximately 10, and the dielectric constant of the trailing edge region is approximately 30. This gradient dielectric constant can be achieved by controlling the doping concentration of the high dielectric nanoparticles: a lower doping concentration in the leading edge region and a higher doping concentration in the trailing edge region. This gradient structure, based on electric field theory, can concentrate the electric field strength at the serrated tip of the trailing edge of the discharge layer 60, typically enhancing it by 8 to 15 times, thereby significantly reducing the discharge initiation voltage. The material of the electric field enhancement layer 50 can be, for example, a barium titanate / polyimide composite material or a strontium titanate / epoxy composite material.

[0035] In another preferred embodiment, the electric field enhancement layer 50 is made of an electrostrictive or electrovariant material whose dielectric constant and / or microstructure can automatically change in response to the intensity of an externally applied electric field, so that the composite film has adaptive discharge capability and maintains stable discharge performance under different altitudes and electrostatic accumulation levels.

[0036] The discharge layer 60 is located above the electric field enhancement layer 50 and comprises a high-temperature resistant resin matrix (such as bismaleimide, polyimide, etc.) and high-resistance discharge fibers (such as silicon carbide fibers, doped carbon fibers, or conductive polymer fibers). The resistivity of the high-resistance discharge fibers is preferably 10 Ω·cm. 6 ~10 9 The fiber diameter is 5–15 μm, and the fiber volume fraction is 15%–30%. The trailing edge of the discharge layer 60 is constructed with a serrated structure for concentrating the electric field. The serration height is 10–50 mm, the serration width is 2–6 mm, and the radius of curvature of the serration tip is ≤2 mm. In a preferred embodiment, the electric field enhancement layer 50 and the discharge layer 60 have complementary rectangular toothed edges on their front sides to increase the bonding area and structural stability. More preferably, the high-resistance discharge fibers in the discharge layer 60 are oriented along the direction from the leading edge to the trailing edge of the composite film; and, at least in the serrated structure region at its trailing edge, a portion of the high-resistance discharge fibers are arranged perpendicular to the edge of the serrated structure. The protective layer 70 is locally thinned in the region corresponding to the serrated structure of the discharge layer 60, exposing the ends of the high-resistance discharge fibers (e.g., exposing 20–50 μm), thereby forming a micro-discharge tip array. The macro-serrations and the micro-tip array work together to further reduce the corona discharge threshold and improve the discharge efficiency.

[0037] A protective layer 70 covers the discharge layer 60. Exemplarily, the protective layer 70 may be a fluorinated polyimide or polyetheretherketone (PEEK) film with a thickness of 10–30 μm. The main function of the protective layer 70 is to protect the underlying discharge layer 60 from mechanical abrasion, ultraviolet radiation, rain erosion, and the effects of the curing process. Preferably, the protective layer 70 is locally thinned (e.g., to 5 μm) in areas corresponding to the serrated structure of the discharge layer 60, exposing the ends of the high-resistance discharge fibers while maintaining overall coverage. This ensures both discharge functionality and resistance to environmental aging.

[0038] Preferably, the total thickness of the composite membrane is no greater than 0.8 mm, and the areal density is no greater than 100 g / m³. 2 In a more preferred embodiment, the total thickness is no more than 0.5 mm to achieve the goal of ultra-thin and lightweight.

[0039] The present invention also provides a method for preparing the above-mentioned composite film with electrostatic discharge function. Exemplarily, it includes the following steps: S1: Provide release paper. For example, use a 75μm thick high-temperature resistant PET release film, coated with a fluorinated release agent and cured.

[0040] S2: Form an adhesive layer 20 on the release paper. For example, apply a high-temperature curing acrylic pressure-sensitive adhesive with a coating thickness of 30 μm and dry at 80°C for 5 minutes.

[0041] S3: An insulating layer 30 is formed on the adhesive layer 20. For example, a 75 μm thick polyimide film is bonded to the adhesive layer 20 and hot-pressed at 100°C and 0.2 MPa.

[0042] S4: A conductive connection layer 40 is formed in a designated leading edge region on the upper surface of the insulating layer 30. For example, nickel-plated carbon conductive fabric is laid in a 15mm leading edge region, or conductive silver paste is screen-printed and then dried and cured, with the thickness controlled at 15μm.

[0043] S5: An electric field enhancement layer 50 is formed by coating the insulating isolation layer 30 and the conductive connection layer 40. For example, a barium titanate / polyimide precursor solution is prepared, coated using a blade coating process to a thickness of 30 μm, and pre-cured at 120°C for 10 minutes.

[0044] S6: Form a discharge layer 60 containing high-resistance discharge fibers and having a serrated structure at the trailing edge on the electric field enhancement layer 50. For example, prepare a high-resistance discharge fiber reinforced prepreg (fiber volume fraction 20%), with the high-resistance discharge fibers arranged parallel to the length direction of the composite film (i.e., from the leading edge region to the trailing edge serrated structure, which is basically consistent with the airflow direction on the aircraft surface after installation), and hot press it at 150°C and 0.5MPa. At the same time, form a continuous multi-serrated structure at the trailing edge using a mold, with the thickness controlled to 200μm.

[0045] S7: A protective layer 70 is formed by coating the discharge layer 60, and local thinning is performed in the area corresponding to the serrated structure. For example, a fluorinated polyimide solution is coated with a thickness of 20 μm, and the trailing edge serrated area is locally thinned to 5 μm through a mask, and pre-cured at 150°C for 10 minutes.

[0046] S8: Wind up the film to obtain the composite film. Cut to the designed width, wind up, and vacuum pack.

[0047] The present invention will be further described below through a specific embodiment.

[0048] Example This embodiment provides a composite membrane with electrostatic discharge function, and its preparation process is as follows: First, prepare the release paper: Select a 75μm thick high-temperature resistant PET release film, coat it with a fluorinated release agent, and cure it. Then, coat the surface of the release paper with a high-temperature curing acrylic pressure-sensitive adhesive, with a coating thickness of 30μm, and dry it at 80℃ for 5 minutes to form a 20μm adhesive layer.

[0049] Next, a 75μm thick polyimide film is bonded to the adhesive layer 20 and hot-pressed at 100℃ and 0.2MPa to form an insulating layer 30. Then, nickel-plated carbon conductive fabric (or screen-printed conductive silver paste and dried and cured) with a thickness of 15μm is laid on the leading edge area (15mm wide) to form a conductive connection layer 40.

[0050] A barium titanate / polyimide precursor solution was prepared, wherein the doping concentration of barium titanate nanoparticles was designed to be gradient distribution (lower concentration in the leading edge region and higher concentration in the trailing edge region). The solution was coated using a blade coating process to a thickness of 30 μm and pre-cured at 120 °C for 10 minutes to form an electric field enhancement layer 50.

[0051] Preparation of discharge layer 60: A high-resistance discharge fiber-reinforced prepreg was prepared using silicon carbide fiber (10 μm in diameter, 108 Ω·cm resistivity) and bismaleimide resin. The fiber volume fraction was 20%. During layup, the fiber arrangement direction was parallel to the length direction of the composite film (i.e., from the leading edge to the trailing edge serrated structure). The film was hot-pressed at 150℃ and 0.5 MPa. At the same time, a continuous multi-serrated structure (serration height 30 mm, width 4 mm, tooth tip curvature radius 1.5 mm) was formed on the trailing edge using a mold. The thickness was controlled to be 200 μm.

[0052] A fluorinated polyimide solution is coated as a protective layer 70 with a thickness of 20 μm. The trailing edge serrated area is locally thinned to 5 μm using a mask to expose the ends of the high-resistance discharge fibers (exposed length approximately 20–50 μm), forming a microscopic discharge tip array. The mixture is then pre-cured at 150°C for 10 minutes. Finally, it is cut to the designed width, wound up, and vacuum-packed to obtain the composite film.

[0053] like Figure 2 As shown, the composite film prepared in this embodiment includes, from bottom to top, the following layers: release paper layer 10, adhesive layer 20, insulating isolation layer 30, conductive connection layer 40, electric field enhancement layer 50 (30μm barium titanate / polyimide gradient dielectric constant material, leading edge ε≈10, trailing edge ε≈30), discharge layer 60 (200μm silicon carbide fiber / bismaleimide, trailing edge continuous multi-serrated structure, fibers arranged along the direction from leading edge to trailing edge, some fibers in the serrated structure area perpendicular to the serrated edge), and protective layer 70 (20μm fluorinated polyimide, locally thinned to 5μm in the trailing edge serrated area).

[0054] The composite membrane prepared in this embodiment has a total thickness of approximately 0.48 mm and an areal density of approximately 95 g / m³. 2 In use, peel off the release paper layer 10 and apply the composite film to the surface of the uncured carbon fiber prepreg (such as the prepreg layup surface of composite components like wings, vertical tails, or rotor blades). Then, place the film and mold together in an autoclave for co-curing (curing parameters are consistent with those of the composite component, e.g., 180℃, 0.6MPa, 2 hours). After curing, the composite film and the composite component form an integrated structure, achieving integrated electrostatic discharge functionality with the composite component.

[0055] The composite film was subjected to performance testing, and its leading-edge to trailing-edge resistance was within 10. 6 ~10 9 Within the Ω range, it meets the requirements for electrostatic discharge pathways; the adhesion was tested using the cross-cut test and reached the Class 1 standard, indicating that there is good bonding strength between the layers and between the composite film and the composite material component.

[0056] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0057] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A composite membrane with electrostatic discharge function, characterized in that, It is a multi-layer thin film structure used for co-curing with composite material components; the composite film comprises, from the side to be bonded to the side exposed to air, the following components in sequence: Peelable release paper layer; Adhesive layer, used for bonding to composite material components; An insulating layer is provided for electrical isolation from the composite material component. A conductive connection layer is disposed in a local area above the insulating isolation layer for establishing an electrical connection; An electric field enhancement layer, located above the conductive connection layer, is used to regulate and enhance the electric field distribution; The discharge layer, located above the electric field enhancement layer, comprises a high-temperature resistant resin matrix and high-resistance discharge fibers, and its trailing edge is constructed with a serrated structure for concentrating the electric field. A protective layer covers the discharge layer.

2. The composite membrane with electrostatic discharge function according to claim 1, characterized in that, The volume resistivity of the insulating layer is not less than 10. 14 Ω·cm is used to isolate the discharge layer from the composite material component, allowing static charge to be guided into the discharge path through the conductive connection layer.

3. The composite membrane with electrostatic discharge function according to claim 1, characterized in that, The conductive connection layer is disposed in the leading edge region of the composite film, and its sheet resistance is not greater than 5Ω / □.

4. The composite membrane with electrostatic discharge function according to claim 1, characterized in that, The electric field enhancement layer is made of a high dielectric constant material, and its dielectric constant gradually increases from the leading edge region to the trailing edge serrated structure, with a dielectric constant range of 10 to 30.

5. The composite membrane with electrostatic discharge function according to claim 1, characterized in that, The electric field enhancement layer is made of an electrostrictive or electrovariant material, whose dielectric constant and / or microstructure can change automatically in response to the intensity of an externally applied electric field, thereby enabling the composite film to have adaptive discharge capability.

6. The composite membrane with electrostatic discharge function according to claim 1, characterized in that, The electric field enhancement layer and the discharge layer have complementary rectangular toothed edges on the front side.

7. The composite membrane with electrostatic discharge function according to claim 1, characterized in that, In the discharge layer, at least in the serrated structure region at its trailing edge, some of the high-resistance discharge fibers are arranged perpendicular to the edge of the serrated structure; the protective layer is locally thinned in the region corresponding to the serrated structure of the discharge layer, exposing the ends of the high-resistance discharge fibers, thereby forming a micro-discharge tip array.

8. The composite membrane with electrostatic discharge function according to claim 1, characterized in that, The adhesive layer is an acrylic pressure-sensitive adhesive layer, an epoxy resin film, or a bismaleimide film, and the bonding or curing temperature of the adhesive layer is matched with the molding process of the composite material component.

9. The composite membrane with electrostatic discharge function according to claim 1, characterized in that, The total thickness of the composite membrane is no greater than 0.8 mm, and the areal density is no greater than 100 g / m³. 2 .

10. A method for preparing a composite film with electrostatic discharge function as described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Provide release paper; S2: Form an adhesive layer on the release paper; S3: An insulating layer is formed on the adhesive layer; S4: A conductive connection layer is formed in a predetermined leading edge region on the upper surface of the insulating layer; S5: An electric field enhancement layer is formed by coating the insulating isolation layer and the conductive connection layer; S6: Form a discharge layer containing high-resistance discharge fibers and having a serrated structure at the trailing edge on the electric field enhancement layer; S7: A protective layer is coated on the discharge layer to form a protective layer, and local thinning is performed in the area corresponding to the sawtooth structure; S8: Wind up the film to obtain the composite film.

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