A method for preparing high-strength multi-component mica tape

Abstract

The application relates to the technical field of insulating material preparation, and discloses a preparation method of high-strength multi-component mica tape, which comprises the following steps: S1. adhesive preparation: 100 parts of base resin, 20 parts of active toughening agent and 5 parts of surface modified nano filler are placed in a reaction kettle, high shear dispersion is carried out at 75 DEG C and a rotating speed of 3000 rpm for 50 minutes, and a homogeneous multi-component adhesive is prepared; S2. primary substrate impregnation: glass fiber cloth is guided to pass through a constant-temperature impregnation tank with a temperature controlled at 45 DEG C, so that the double sides of the glass fiber cloth are uniformly attached with the multi-component adhesive. In the high-strength multi-component mica tape preparation method, during high-temperature crosslinking, a rubber phase and an epoxy-silicone resin phase form an interpenetrating polymer network, and nano whiskers are uniformly inserted into the network, the structure can cause matrix crazing and shear bands when stress is applied, and can effectively dissipate external force impact energy.

Description

Technical Field

[0001] This invention relates to the field of insulating material preparation technology, specifically a method for preparing high-strength multi-component mica tape. Background Technology

[0002] Mica tape, as a high-performance insulating material, is widely used in the main insulation systems of coils in large generators, high-voltage motors, and traction motors due to its excellent corona resistance and high-temperature resistance. With the development of modern motors towards high voltage, large capacity, and miniaturization, motor coils are typically manufactured using high-speed automated winding processes, which places extremely high demands on the mechanical properties of mica tape (especially tensile strength and bending resistance).

[0003] Currently, the closest existing technology in the industry usually uses conventional epoxy resin or polyester resin as an adhesive to combine glass fiber cloth and mica paper through a simple impregnation and baking process, which improves production efficiency by adding a single latent curing agent. However, the aforementioned existing technologies have significant technical drawbacks in practical applications: due to the significant differences in polarity and coefficient of thermal expansion among mica, glass fiber, and resin, conventional adhesives struggle to form strong chemical bonds between the multiphase interfaces. Under the high tension of high-speed mechanical wrapping, stress concentration easily occurs at the internal multiphase interfaces, leading to micro-cracks or breakage of the mica tape. Furthermore, the single resin is prone to embrittlement at high temperatures, failing to effectively buffer the thermomechanical stress during motor operation, ultimately causing insulation layer peeling and reducing the motor's service life. Summary of the Invention

[0004] This invention provides a method for preparing high-strength multi-component mica tape, which has the advantages of improved tensile strength under normal conditions and greatly reduced tape breakage rate, thus solving the problems mentioned in the background art.

[0005] This invention provides the following technical solution: A method for preparing a high-strength multi-component mica tape includes the following steps: S1. Adhesive preparation: 100 parts of base resin, 20 parts of active toughening agent and 5 parts of surface-modified nanofiller are placed in a reaction vessel and dispersed under high shear at 3000 rpm for 50 minutes at 75°C to obtain a homogeneous multi-component adhesive. S2. Initial impregnation of substrate: Guide the glass fiber cloth through a constant temperature impregnation bath with the temperature controlled at 45°C, so that the multi-component adhesive is evenly adhered to both sides of the glass fiber cloth. S3. Composite Roll Pressing and Lamination: The powdered mica paper and the impregnated glass fiber cloth are simultaneously fed into the hot press roller and compositely laminated under a linear pressure of 1MPa and a roller surface temperature of 80°C to form a preliminary mica tape product. S4. Gradient crosslinking and curing: The initial mica tape is fed into a multi-temperature zone tunnel oven and subjected to gradient heating, solvent removal and semi-curing treatments in sequence. After cooling, it is wound up to obtain the high-strength multi-component mica tape.

[0006] Further: In step S1, the base resin is a composite of bisphenol F type epoxy resin and organosilicon resin mixed in a mass ratio of 4:1; the active toughening agent is carboxyl-terminated butadiene-acrylonitrile rubber; and the surface-modified nanofiller is nano-silica whiskers treated with silane coupling agent KH-560.

[0007] Further: In step S2, the constant temperature impregnation tank is equipped with a multi-stage ultrasonic generator. During the impregnation process, ultrasonic oscillation is activated, the ultrasonic frequency is set to 35kHz, and the ultrasonic power density is 0.4W / cm³. 2 .

[0008] Further: In step S4, the gradient crosslinking curing specifically includes the following sub-steps: S41. Desolventization stage: Bake at a constant temperature of 90°C for 4 minutes in the first temperature zone; S42. Pre-crosslinking stage: Increase the temperature to 140°C at a heating rate of 5°C / min in the second temperature zone and hold for 6 minutes; S43. Semi-curing stage: Bake at 170°C for 3 minutes in the third temperature zone to control the gelation degree of the adhesive to between 30%.

[0009] Further: In step S1, before high-shear dispersion, a mixed solvent needs to be added to the reaction vessel to adjust the viscosity of the system; the mixed solvent is a mixture of toluene and methyl ethyl ketone in a volume ratio of 1:1; after dispersion, the dynamic viscosity of the multi-component adhesive at an ambient temperature of 25°C is precisely controlled at 280 mPa·s.

[0010] Further: The pre-preparation process of the surface-modified nanofiller (i.e., nano-silica whiskers treated with KH-560) includes: dispersing nano-silica whiskers with an aspect ratio of 10:1 in anhydrous ethanol, adding 2% by mass of silane coupling agent KH-560, refluxing at 70°C for 3 hours, and then obtaining the product after centrifugation, washing and vacuum drying.

[0011] Further: In step S3, when the powdered mica paper and the impregnated glass fiber cloth are simultaneously fed into the hot press roller, dynamic micro-tension control is implemented; wherein, the unwinding tension of the glass fiber cloth is controlled at 20 N / m, and the unwinding tension of the powdered mica paper is controlled at 8 N / m.

[0012] Further: After step S4, there is also a thermodynamic stress release and cooling step before winding: the semi-cured mica tape is sent into a slow cooling zone and cooled at a uniform rate of 3°C / min to below 30°C; the slow cooling zone is equipped with an array of electrostatic elimination devices to neutralize the static electricity accumulation on the surface of the mica tape.

[0013] Furthermore: the total thickness of the mica tape is 0.10 mm; wherein, the diameter of the single filament of the glass fiber cloth is 5 μm, and the interpenetrating polymer network formed by the glass fiber cloth and the multi-component adhesive after curing exhibits a mechanical anchoring structure at the microscopic interface; and the tensile strength of the mica tape under normal conditions is not less than 150 N / 10 mm, and the volatile content is controlled at 1.5%.

[0014] Beneficial effects: The high-strength multi-component mica tape preparation method of this invention introduces carboxyl-terminated nitrile butadiene rubber and surface-modified nano-silica whiskers into a multi-component adhesive. During high-temperature crosslinking, the rubber phase and the epoxy-organic silicone resin phase form an interpenetrating polymer network, with the nano-whiskers uniformly interwoven within. This structure can induce crazing and shear banding in the matrix under stress, effectively dissipating the impact energy of external forces. Compared with traditional methods, the mica tape prepared by this invention has a 18%-25% higher tensile strength under normal conditions than other high-strength multi-component mica tape preparation methods. This effectively meets the high-tension requirements of high-speed automated wrapping in high-strength multi-component mica tape preparation methods at 600-800 rpm, and greatly reduces the tape breakage rate.

[0015] The high-strength multi-component mica tape preparation method of this invention utilizes a composite ultrasonic oscillation process in a constant-temperature impregnation bath to break the surface tension of the adhesive through cavitation, allowing the adhesive to deeply penetrate the micropores of the glass fiber and the interlayer gaps of the mica paper, forcibly expelling tiny air bubbles between the multiphase interfaces. This improvement in physical dimensions results in a denser interfacial bond in the mica tape, increasing the peel strength at high temperature (155°C) by more than 15% compared to other high-strength multi-component mica tape preparation methods, while effectively avoiding the risk of partial discharge.

[0016] The high-strength multi-component mica tape preparation method of this invention employs a three-stage gradient crosslinking and curing process—solvent removal, pre-crosslinking, and semi-curing—to match the solvent evaporation rate with the three-dimensional network crosslinking rate of the resin. This technique avoids the surface skinning and internal thermal stress residue problems caused by traditional rapid heating processes, ensuring the final product maintains excellent flexibility. Simultaneously, it precisely controls the degree of gelation in the semi-cured state within the 25%-35% range of other high-strength multi-component mica tape preparation methods, guaranteeing excellent flowability and curing quality of the mica tape during subsequent hot pressing of motor coils. Attached Figure Description

[0017] Figure 1 This is a hierarchical technical flow diagram of the present invention; Figure 2 Analysis of test results for this invention and comparative examples; Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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. Example 1

[0019] Please see Figure 1-2 A method for preparing high-strength multi-component mica tape includes the following steps: S1. Adhesive preparation: 100 parts of base resin, 20 parts of active toughening agent and 5 parts of surface modified nanofiller were placed in a reaction vessel and dispersed under high shear at 3000 rpm for 50 minutes at 75°C to obtain a homogeneous multi-component adhesive. S2. Initial impregnation of the substrate: Guide the glass fiber cloth through the constant temperature impregnation bath controlled at 45°C, so that the high-strength multi-component mica tape preparation method glass fiber cloth is uniformly adhered to both sides by the high-strength multi-component mica tape preparation method multi-component adhesive. S3. Composite Roll Pressing and Lamination: The powdered mica paper and the glass fiber cloth impregnated with high-strength multi-component mica tape are simultaneously fed into the hot press roller and compositely laminated under a linear pressure of 1MPa and a roller surface temperature of 80°C to form the initial mica tape product. S4. Gradient crosslinking and curing: The initial mica tape prepared by the high-strength multi-component mica tape preparation method is fed into a multi-temperature zone tunnel furnace, and sequentially subjected to gradient heating, solvent removal and semi-curing treatment. After cooling, it is wound up to obtain the high-strength multi-component mica tape prepared by the high-strength multi-component mica tape preparation method.

[0020] In step S1, the base resin, active toughening agent, and nanofiller are subjected to high-shear dispersion at 75°C. This temperature range effectively reduces resin viscosity to facilitate uniform dispersion of the nanofiller and prevents early cross-linking reactions in the toughening system. A rotation speed of 3000 rpm provides sufficient mechanical shear force to break up the agglomeration of nanoparticles, ensuring a homogeneous system. In step S2, glass fiber cloth is passed through a 45°C constant-temperature impregnation bath. This constant temperature control is crucial for maintaining the penetration dynamics of the adhesive: excessively high temperatures cause rapid solvent evaporation, leading to a sharp increase in viscosity, while excessively low temperatures restrict molecular chain activity and result in insufficient penetration. In step S3, a hot-press roller composites the powdered mica paper and impregnated glass fiber cloth under a linear pressure of 1 MPa and a roller surface temperature of 80°C. This pressure range is precisely controlled to ensure that the resin can be effectively squeezed into the micro-layer gaps between the two materials to form a "mechanical interlocking effect," while avoiding excessive pressure that could crush the fragile mica flake crystal structure. Finally, gradient crosslinking and curing were carried out in a multi-temperature zone tunnel oven in step S4, which achieved stable solvent removal and controllable crosslinking of the polymer network, ultimately producing a finished mica tape with extremely high tensile strength.

[0021] In step S1, the base resin in the high-strength multi-component mica tape preparation method is a composite of bisphenol F type epoxy resin and organosilicon resin mixed in a mass ratio of 4:1; the active toughening agent in the high-strength multi-component mica tape preparation method is carboxyl-terminated butadiene-acrylonitrile rubber; and the surface-modified nanofiller in the high-strength multi-component mica tape preparation method is nano-silica whiskers treated with silane coupling agent KH-560.

[0022] The base resins are bisphenol F epoxy resin and silicone resin (mass ratio 4:1). Bisphenol F epoxy resin provides excellent room temperature mechanical strength and low operating viscosity, while the introduction of silicone, relying on the high bond energy of its Si-O bonds, significantly improves the system's heat resistance (H class or above) and high-frequency electrical insulation. The active toughening agent, carboxyl-terminated nitrile butadiene rubber (CTBN), acts as a "flexible bridge" in the formulation. During high-temperature curing, CTBN undergoes microphase separation, with its terminal carboxyl groups reacting with epoxy groups in a ring-opening reaction. This forms elastic rubber spherical microphases that interpenetrate within the rigid epoxy-silicone network, constructing an interpenetrating polymer network (IPN). When the mica tape is subjected to high-speed wrapping tension, this flexible microphase absorbs and deforms to dissipate impact energy. Furthermore, the nano-silica crystals require pre-treatment with the silane coupling agent KH-560. The alkoxy groups at one end of KH-560 condense with the hydroxyl groups on the whisker surface, while the epoxy groups at the other end directly participate in the cross-linking reaction of the matrix resin. This makes the nanowhiskers no longer simple physical impurity fillers, but rather "anchored" in the polymer network by strong chemical bonds. When micro-stress cracks occur, the whiskers can effectively induce crazes and forcibly block the further propagation of microcracks, achieving synergistic toughening with both rigidity and flexibility.

[0023] In step S2, the constant-temperature impregnation bath in the high-strength multi-component mica tape preparation method is equipped with a multi-stage ultrasonic generator. During the impregnation process, ultrasonic oscillation is activated, with the ultrasonic frequency set to 35 kHz and the ultrasonic power density to 0.4 W / cm². 2 Fiberglass cloth is composed of countless micron-sized monofilaments bundled together. Conventional static gravity impregnation is insufficient to squeeze high-viscosity multi-component resin into the capillary-like interfiber spaces, easily leaving micron-sized air bubbles, thus creating weak points for electrical breakdown. This application employs an array of multi-stage ultrasonic generators within a constant-temperature impregnation bath, strictly locking the ultrasonic frequency at 35kHz and controlling the ultrasonic power density at 0.4W / cm². 2 At this frequency and power level, ultrasound induces a strong cavitation effect in liquid adhesives: in the negative pressure phase, tens of thousands of tiny vacuum bubbles are generated in the adhesive; in the positive pressure phase, these bubbles instantly close and collapse, generating strong microjets and shock waves. This microscopic physical impact force, reaching hundreds of atmospheres, acts like a "miniature pump," forcibly stripping gas molecules attached to the surfaces of glass fibers and mica, and forcing the adhesive to penetrate deeply into the glass fiber bundles. It is important to emphasize that if the power density is below 0.3 W / cm², the effect is less pronounced. 2 If the cavitation energy level is insufficient, degassing will be incomplete; if it is higher than 0.5 W / cm 2 Excessive shock waves can break the molecular chains of glass fibers, thereby damaging the mechanical framework of the substrate. This precise control procedure completely eliminates the potential for air gaps at multiphase interfaces.

[0024] In step S4, the gradient crosslinking and curing method for preparing high-strength multi-component mica tape specifically includes the following sub-steps: S41. Desolventization stage: Bake at a constant temperature of 90°C for 4 minutes in the first temperature zone; S42. Pre-crosslinking stage: Increase the temperature to 140°C at a heating rate of 5°C / min in the second temperature zone and hold for 6 minutes; S43. Semi-curing stage: Bake at 170°C for 3 minutes in the third temperature zone to control the gelation degree of the adhesive to between 30%.

[0025] As a semi-cured insulating material, the degree of curing of mica tape directly determines the density and smoothness of its coating on motor coils. In the S41 desolventizing stage (90°C, 4 minutes), a gentle baking process is used, with the temperature below or near the solvent's boiling point, allowing volatiles to gradually escape from the inside out. Rapid heating at high temperatures is strictly prohibited in this stage, otherwise, premature cross-linking and skin formation of the surface adhesive will block the evaporation channels, leading to rapid vaporization of the internal solvent and the formation of "bursting bubble defects." In the S42 pre-crosslinking stage (heating to 140°C and holding for 6 minutes), the latent curing agent in the system is thermodynamically activated, and the polymer undergoes initial molecular chain extension and mild cross-linking. The system viscosity increases but has not yet lost its macroscopic fluidity. In the crucial S43 semi-curing stage (170°C, 3 minutes), the cross-linking reaction accelerates dramatically. This invention precisely anchors the final gelation degree of the adhesive within a 30% process window by precisely controlling the baking time in this temperature range. Theory and extensive experiments show that if the gelation degree is below 25%, the mica tape is prone to stickiness, glue flow, and delamination during storage and transportation at room temperature; if the gelation degree is above 35%, the excessively deep three-dimensional network cross-linking of the resin causes the mica tape to harden and become brittle, making it extremely easy to break during high-speed winding and unable to remelt and flow to fill the microscopic pores between the coils during the final hot-pressing and curing of the motor. This three-stage temperature control perfectly balances storage stability and final molding processability.

[0026] In step S1, before high-shear dispersion, a mixed solvent needs to be added to the reactor to adjust the viscosity of the system; the mixed solvent is a mixture of toluene and methyl ethyl ketone in a volume ratio of 1:1; after dispersion, the dynamic viscosity of the multi-component adhesive at an ambient temperature of 25°C is precisely controlled at 280 mPa·s.

[0027] This invention specifies that the mixed solvent is a 1:1 volume ratio of toluene and methyl ethyl ketone (MEK). Toluene, as a non-polar solvent, is mainly used to ensure the full extension of the bisphenol F epoxy resin molecular chains and the swelling of the toughening rubber phase; while MEK, as a moderately polar solvent, can significantly reduce the surface tension of the system. The 1:1 ratio balances the solvent's solubility and the stepwise evaporation gradient of the subsequent S41 stage. In this embodiment, the dynamic viscosity of the multi-component adhesive at 25°C is precisely locked at 280 mPa·s using this solvent system. This viscosity value is determined based on the rheological requirements of the subsequent ultrasonic cavitation infiltration process: if the viscosity is higher than 280 mPa·s, the energy of the microjets generated by the ultrasound will be dissipated by high internal friction, resulting in a "dry zone" in the center of the fiber bundle; if the viscosity is too low, the adhesive will be severely affected by gravity after coating, and it will be unable to maintain a uniform coating thickness on the fiberglass cloth surface. 280 mPa·s ensures that the adhesive has excellent permeability while possessing sufficient initial tack.

[0028] The pre-preparation process of surface-modified nanofiller (i.e., nano-silica whiskers treated with KH-560) includes: dispersing nano-silica whiskers with an aspect ratio of 10:1 in anhydrous ethanol, adding 2% by mass of silane coupling agent KH-560, refluxing at 70°C for 3 hours, and then centrifuging, washing and vacuum drying to obtain the final product.

[0029] This embodiment uses nano-silica whiskers with an aspect ratio of 10:1. This aspect ratio provides effective bridging and toughening in macroscopic mechanics while avoiding breakage due to shear forces during dispersion caused by an excessively large aspect ratio. 2% KH-560 (by mass) was added dropwise to anhydrous ethanol and refluxed at 70°C for 3 hours. From a reaction kinetics perspective, 70°C provides sufficient activation energy to promote the hydrolysis of the alkoxy groups in the silane coupling agent and their condensation with the hydroxyl groups on the whisker surface, while the 3-hour duration ensures that the grafting density reaches saturation. The 2% concentration is an optimized critical point: below this value, insufficient exposure of active sites on the whisker surface prevents effective covalent bonding with the resin matrix during curing; above 2%, excess silane undergoes self-condensation to form a loose physical adsorption layer, which becomes a weak point for interfacial slip under stress, leading to a decrease in tensile strength.

[0030] In step S3, dynamic micro-tension control is implemented when the powdered mica paper and the impregnated glass fiber cloth are simultaneously fed into the hot press roller; wherein, the unwinding tension of the glass fiber cloth is controlled at 20 N / m, and the unwinding tension of the powdered mica paper is controlled at 8 N / m.

[0031] This invention introduces asymmetric dynamic micro-tension control. Specifically, the unwinding tension of the glass fiber cloth is set at 20 N / m, and the unwinding tension of the powdered mica paper is set at 8 N / m. This 2.5:1 tension difference is designed based on the significant difference in Young's modulus between the two materials. As the main load-bearing skeleton, the glass fiber cloth requires a high tension (20 N / m) to ensure its flatness under high-speed rolling and prevent physical wrinkling; while the powdered mica paper has an extremely brittle structure and poor tensile strength. If the tension exceeds 10 N / m, it is prone to micro-tears at the point of lowest strength when it comes into contact with the adhesive and becomes wetted. By controlling the tension of the mica paper at 8 N / m, it adheres to the glass fiber cloth in a nearly "relaxed" state, and the glass fiber cloth carries the mica paper into the hot-pressing zone, effectively eliminating the accumulation of internal stress during the composite process and ensuring that the finished product does not curl or delaminate.

[0032] After step S4, there is also a thermodynamic stress release and cooling step before winding: the semi-cured mica tape is sent into the slow cooling zone and cooled at a uniform rate of 3°C / min to below 30°C; the slow cooling zone is equipped with an array of static elimination devices to neutralize the static electricity accumulation on the surface of the mica tape.

[0033] Before winding, the semi-cured mica tape undergoes a uniform slow cooling process at a rate of 3°C / min. From a polymer physics perspective, the semi-cured resin is in the sensitive region of glass transition. A cooling rate of 3°C / min allows sufficient time for the macromolecular chains to undergo thermodynamic relaxation, thereby releasing the thermal stress caused by the high temperature of the tunnel oven. If the cooling rate is too fast (e.g., greater than 10°C / min), due to the mismatch in thermal expansion coefficients between mica and glass fiber, a huge microscopic thermal shear force will be generated at the interface, leading to peeling after winding. A synchronously configured array electrostatic eliminator neutralizes the charge and solves the electrostatic attraction generated by the mica tape under high-speed friction. This not only ensures the neatness of winding but, more importantly, prevents the risk of ignition of residual solvent in the resin by electrostatic sparks and avoids the adsorption of environmental dust by charged particles, ensuring the purity of electrical insulation.

[0034] The total thickness of the mica tape is 0.10 mm; the diameter of the single filament of the glass fiber cloth is 5 μm, and the interpenetrating polymer network formed by it and the multi-component adhesive after curing exhibits a mechanical anchoring structure at the microscopic interface; and the tensile strength of the mica tape under normal conditions is not less than 150 N / 10 mm, and the volatile content is controlled at 1.5%.

[0035] The final high-strength multi-component mica tape has a total thickness of 0.10 mm. To achieve a tensile strength of ≥150 N / 10 mm at such a thin scale, this embodiment specifically selected ultra-fine glass fiber monofilaments with a diameter of 5 μm. The ultra-fine monofilaments provide a huge specific surface area, allowing the resin to form a high-density interpenetrating polymer network (IPN) and physical-mechanical anchoring with the fiber even with a low volatile content of 1.5%. The 1.5% volatile content is the golden balance point between storage stability and processability: if it is below 1%, the mica tape will lose its "sticky feel" and fail to adhere properly when wrapped around the motor coil; if it is above 1.5%, excessive residual solvent vaporization will produce macroscopic pores during subsequent overall motor heating and curing (after the VPI process). Therefore, this value ensures the electrical reliability of the finished product under subsequent high-temperature and high-pressure service environments.

[0036] Compare with Example 1 Compared to Example 1, this comparative example has no toughening network, and the adhesive consists of 100 parts of base resin and 5 parts of surface-modified nanofiller, with the rest being the same as in Example 1.

[0037] Compare with Example 2 Compared with Example 1, in step S2, this comparative example did not have ultrasonic defoaming, but the rest was the same as in Example 1.

[0038] Compare with Example 3 Compared with Example 1, in step S3, this comparative example uses a 15 N / m constant tension composite, and the rest is the same as in Example 1.

[0039] Compare with Example 4 Compared with Example 1, in step S4, this comparative example does not have gradient curing treatment, but uses constant temperature curing at 100°C, and the rest is the same as Example 1.

[0040] The products prepared using the technical solution of this invention and the control examples were subjected to performance tests, and the results are as follows: Figure 2 As shown, the product prepared by this invention has a smooth and conforming macroscopic appearance, good strength, and a gelation degree within the golden range, exhibiting excellent overall performance.

[0041] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing high-strength multi-component mica tape, characterized in that, Includes the following steps: S1. Adhesive preparation: 100 parts of base resin, 20 parts of active toughening agent and 5 parts of surface modified nanofiller were placed in a reaction vessel and dispersed under high shear at 3000 rpm for 50 minutes at 75°C to obtain a homogeneous multi-component adhesive. S2. Initial impregnation of substrate: Guide the glass fiber cloth through a constant temperature impregnation bath with the temperature controlled at 45°C, so that the multi-component adhesive is evenly attached to both sides of the glass fiber cloth. S3. Composite Roll Pressing and Lamination: The powdered mica paper and the impregnated glass fiber cloth are simultaneously fed into the hot press roller and compositely laminated under a linear pressure of 1MPa and a roller surface temperature of 80°C to form a preliminary mica tape product. S4. Gradient crosslinking and curing: The initial mica tape is fed into a multi-temperature zone tunnel oven and subjected to gradient heating, solvent removal and semi-curing treatments in sequence. After cooling, it is wound up to obtain the high-strength multi-component mica tape.

2. The preparation method according to claim 1, characterized in that: In step S1, the base resin is a composite of bisphenol F type epoxy resin and organosilicon resin mixed in a mass ratio of 4:1; the active toughening agent is carboxyl-terminated butadiene-acrylonitrile rubber; and the surface-modified nanofiller is nano-silica whiskers treated with silane coupling agent KH-560.

3. The preparation method according to claim 1, characterized in that: In step S2, the constant temperature impregnation tank is equipped with a multi-stage ultrasonic generator. During the impregnation process, ultrasonic oscillation is activated, with the ultrasonic frequency set to 35 kHz and the ultrasonic power density to 0.4 W / cm². 2 .

4. The preparation method according to claim 1, characterized in that: In step S4, the gradient crosslinking curing specifically includes the following sub-steps: S41. Desolventization stage: Bake at a constant temperature of 90°C for 4 minutes in the first temperature zone; S42. Pre-crosslinking stage: Increase the temperature to 140°C at a heating rate of 5°C / min in the second temperature zone and hold for 6 minutes; S43. Semi-curing stage: Bake at 170°C for 3 minutes in the third temperature zone to control the gelation degree of the adhesive to between 30%.

5. High-strength multi-component mica tape prepared by the preparation method according to any one of claims 1 to 4.

6. The preparation method according to claim 1, characterized in that: In step S1, before high-shear dispersion, a mixed solvent needs to be added to the reaction vessel to adjust the viscosity of the system; the mixed solvent is a mixture of toluene and methyl ethyl ketone in a volume ratio of 1:1; after dispersion, the dynamic viscosity of the multi-component adhesive at an ambient temperature of 25°C is precisely controlled at 280 mPa·s.

7. The preparation method according to claim 2, characterized in that: The pre-preparation process of the surface-modified nanofiller (i.e., nano-silica whiskers treated with KH-560) includes: dispersing nano-silica whiskers with an aspect ratio of 10:1 in anhydrous ethanol, adding 2% by mass of silane coupling agent KH-560, refluxing at 70°C for 3 hours, and then centrifuging, washing and vacuum drying to obtain the final product.

8. The preparation method according to claim 1, characterized in that: In step S3, dynamic micro-tension control is implemented when the powdered mica paper and the impregnated glass fiber cloth are simultaneously fed into the hot press roller; wherein, the unwinding tension of the glass fiber cloth is controlled at 20 N / m, and the unwinding tension of the powdered mica paper is controlled at 8 N / m.

9. The preparation method according to claim 1 or 4, characterized in that: After step S4, the process further includes: feeding the semi-cured mica tape sample into a slow cooling zone and cooling it uniformly to below 30°C at a cooling rate of 3°C / min; the slow cooling zone is equipped with an array of electrostatic elimination devices to neutralize the static electricity buildup on the surface of the mica tape.

10. The high-strength multi-component mica tape according to claim 5, characterized in that: The total thickness of the mica tape is 0.10 mm; the diameter of the single filament of the glass fiber cloth is 5 μm, and the interpenetrating polymer network formed by the glass fiber cloth and the multi-component adhesive after curing exhibits a mechanical anchoring structure at the microscopic interface; and the tensile strength of the mica tape under normal conditions is not less than 150 N / 10 mm, and the volatile content is controlled at 1.5%.

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