Low-dielectric high-heat-resistance motor outgoing line insulation material and preparation method thereof

Abstract

The invention discloses a low-dielectric high-heat-resistance motor outgoing line insulation material and a preparation method thereof, and belongs to the technical field of polymer insulation materials. The insulation material is composed of a component A and a component B. The component A comprises boric acid terminated EPDM, a polyolefin elastomer, polypropylene, N-(3, 4-dihydroxyphenethyl)-2-naphthyl formamide and an antioxidant. And the component B comprises LLDPE, polypropylene, a catalyst and an antioxidant. The preparation method comprises the following steps: respectively preparing the component A and the component B, and mixing the component A and the component B in proportion. A dynamic boric acid ester cross-linked network is formed between the boric acid terminated EPDM and the dopamine derivative, so that the final product has excellent low dielectric constant, low dielectric loss, high heat resistance, high insulating strength and unique self-repairing capability; the technical problems that the dielectric property of a traditional silane crosslinking insulating material is deteriorated and damage cannot be self-repaired due to polar small molecules are effectively solved, and the silane crosslinking insulating material is particularly suitable for high-end lead-out wire application scenes such as a high-frequency motor and a metal shielding layer-containing high-end lead-out wire application scene.

Description

Technical Field

[0001] This invention relates to the field of polymer insulating materials technology, and in particular to a special insulating material for motor lead wires with low dielectric constant, high heat resistance and self-healing function, and its preparation method. Background Technology

[0002] Motor leads are key components for power transmission and signal control in motors, and the performance of their insulation materials directly affects the reliability, efficiency, and lifespan of the motor. With industrial development, especially advancements in new energy vehicles and servo motors, higher requirements are being placed on motor leads: higher operating frequencies, higher operating temperatures, and more complex electromagnetic shielding structures.

[0003] Currently, the commonly used insulation materials for motor lead wires are mostly ordinary cross-linked polyethylene (XLPE) or silane cross-linked polyethylene. During the cross-linking process, especially in silane cross-linking systems, these traditional materials are prone to producing polar small molecule byproducts such as alcohols. These residual polar small molecules lead to an increase in the dielectric constant and dielectric loss factor of the insulation material, causing significant signal attenuation and interference under high-speed frequency conversion or high-frequency signal transmission. This problem is particularly prominent in cable structures with metal shielding.

[0004] Furthermore, existing material systems have the following limitations: First, their heat resistance is insufficient, with long-term operating temperatures typically unable to exceed 125°C, failing to meet the demands of higher-temperature operating conditions; second, the uniformity of dispersion of the material's components is difficult to guarantee, affecting the consistency of product performance; third, it is often difficult to simultaneously achieve both mechanical strength and electrical properties. More importantly, once traditional insulating materials suffer even minor scratches or defects during production, installation, or use, their insulation performance will irreversibly decline, potentially leading to insulation failure and posing safety hazards.

[0005] Therefore, there is an urgent need in this field to develop a new type of insulating material that not only has a low dielectric constant, high heat resistance and stable electrical insulation properties, but also has certain functional characteristics, such as the ability to self-repair minor damage, thereby significantly improving the long-term reliability and safety of motor leads. Summary of the Invention

[0006] In order to overcome the shortcomings of the existing technology, the purpose of this application is to provide a low dielectric high heat-resistant motor lead wire insulation material and its preparation method.

[0007] Firstly, the low-dielectric, high-heat-resistant motor lead wire insulation material provided in this application adopts the following technical solution: A low-dielectric, high-heat-resistant motor lead wire insulation material comprising component A and component B; Component A comprises the following raw materials in parts by weight: 15-40 parts of boric acid-terminated EPDM; 25-40 parts of polyolefin elastomer; 25-40 parts of polypropylene; 1.0-2.5 parts of N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide; and 0.5-1.0 parts of antioxidant. Component B comprises the following raw materials in parts by weight: 50-70 parts LLDPE; 20-30 parts polypropylene; 0.02-0.06 parts catalyst; and 0.8-1.5 parts antioxidant.

[0008] By employing the above technical solution, a specific ratio of boric acid-terminated EPDM and N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide is introduced into the insulating material system. During processing and use, these two components reversibly form dynamic boric acid ester bonds, constructing a robust and self-healing three-dimensional cross-linked network. This network structure not only effectively avoids the dielectric property deterioration problem caused by the generation of polar small molecules in traditional silane cross-linking processes, but also endows the material with excellent heat resistance and unique damage self-healing capabilities, thus achieving a high degree of unity between low dielectric constant, low dielectric loss, high heat resistance, and self-healing ability.

[0009] Optionally, the weight ratio of component A to component B is (88-96):(4-12).

[0010] Optionally, the boric acid-capped EPDM is prepared by a method comprising the following steps: dissolving epoxidized EPDM in an organic solvent, reacting it with 3-aminophenylboronic acid at 60-85°C, and obtaining the product by precipitation, washing and drying after the reaction is completed.

[0011] By employing the above technical solution, EPDM is first epoxidized and then its epoxy groups react with the amino groups of 3-aminophenylboronic acid, allowing boric acid groups to be precisely grafted onto the ends of the EPDM molecular chains in a stable chemical bond form. The functionalized polymer prepared by this method serves as a dynamic crosslinking agent, ensuring good compatibility and high reactivity within the matrix, making it a key precursor for achieving high-performance self-healing insulation materials.

[0012] Optionally, the N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide is prepared by a method comprising the following steps: reacting dopamine hydrochloride with 2-naphthoic acid in a buffer solution at pH=8.5 at 25°C, and after the reaction is completed, acidifying, precipitating, washing and drying are performed to obtain the product.

[0013] By employing the above-mentioned technical solution, this synthesis method successfully combines the catechol structure (derived from dopamine) with strong coordination and bonding capabilities with a naphthalene ring possessing hydrophobic and rigid structures. The resulting product not only serves as a dynamic crosslinking point for efficient reaction with boric acid-capped EPDM, but its naphthalene ring structure also generates π-π stacking interactions with the polymer matrix, enhancing interfacial bonding and thus synergistically improving the material's self-healing efficiency and mechanical strength.

[0014] Optionally, component A further includes a functional filler, wherein the functional filler is at least one of boron nitride nanosheets and nano-silica, and the amount added is 1-8 parts.

[0015] Optionally, the functional filler is boron nitride nanosheets with a particle size of 30-50 nm, and the addition amount is 3-6 parts.

[0016] Optionally, component A may further include 5-10 parts of a flame retardant, wherein the flame retardant is ammonium polyphosphate.

[0017] Optionally, the antioxidant is a compound of hindered phenolic antioxidant 1010 and phosphite antioxidant 168, with a compound weight ratio of 1:(0.5-1.5).

[0018] By adopting the above technical solution and using the hindered phenol / phosphite composite antioxidant system, the two work synergistically to provide more comprehensive and long-lasting thermo-oxidative stability protection for the material during high-temperature processing and use, significantly improving the performance retention rate of the material under long-term high-temperature aging environment and extending its service life.

[0019] Secondly, this application provides a method for preparing a low-dielectric, high-heat-resistant motor lead wire insulation material, which adopts the following technical solution: Preparation of Component A: The raw materials of Component A are melt-blended and dynamically cross-linked through a twin-screw extruder, and then pelletized underwater to obtain Component A particles; Preparation of component B: The raw materials of component B are mixed, melt-extruded and granulated to obtain B masterbatch; Preparation of finished product: Mix material A particles with material B masterbatch, and then cool to obtain the insulating material.

[0020] By adopting the above technical solution, the preparation process route is rationally designed. First, the high shear and precise temperature control of the twin-screw extruder ensure that all materials in component A, especially boric acid-terminated EPDM and dopamine derivatives, can be fully melt-mixed and undergo dynamic cross-linking reactions. Second, pre-preparing the catalyst into component B masterbatch facilitates its uniform dispersion in the final product, thereby initiating uniform and controllable cross-linking during subsequent processing or use. This process achieves efficient construction of a dynamic cross-linking network, ensuring the stability and consistency of product performance.

[0021] Thirdly, the motor lead wire provided in this application is made of the low dielectric and high heat resistant motor lead wire insulation material described in the first aspect.

[0022] By adopting the above technical solution, the motor lead wires manufactured using the innovative insulating material of this application have lower signal transmission loss, stronger anti-interference ability, higher upper limit of operating temperature, and inherent damage self-repair ability, thereby significantly improving the operating reliability and service life of the motor under harsh conditions such as high speed, high frequency, and high temperature.

[0023] In summary, this application includes at least one of the following beneficial technical effects: In this application, a dynamic covalent cross-linking network is constructed by using boric acid-terminated EPDM and N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide. This network structure is stable and can avoid the generation of polar small molecules in the traditional cross-linking process, thus enabling the insulating material to have excellent electrical properties with low dielectric constant and low dielectric loss. This application utilizes the reversible properties of dynamic borate ester bonds to enable materials to self-repair through bond reconstruction when damaged. This property solves the industry problem of irreversible performance degradation of traditional insulating materials due to minute defects, thus greatly improving the reliability and service life of the product. 3. By adjusting the A / B group ratio and adding different types of functional additives, the insulating material in this application can flexibly impart higher heat resistance, thermal conductivity, flame retardancy or better processing fluidity to the material while maintaining the core electrical properties, thus meeting the diverse needs of different application scenarios. Detailed Implementation

[0024] The present application will be further described in detail below with reference to the embodiments.

[0025] All raw materials used in the examples are commercially available. EPDM was provided by Mitsui Chemicals, model 4045M, with a Mooney viscosity of 45 (100°C); LLDPE was provided by Mitsui Chemicals, model SP0540, with an MFR of 3.8 g / 10 min (190°C × 2.16 kg); polypropylene was provided by Yanshan Petrochemical; antioxidants 168, 1010, 1024, 1076, and 300 were provided by BASF; silane coupling agent A-171 was provided by Hubei Xinlantian New Materials Co., Ltd.; peroxide DCP was provided by Akzo; and dibutyltin dilaurate was provided by Nantong Haotai Chemical Products Co., Ltd., model HT2401A.

[0026] Preparation Example 1: Preparation of Epoxidized EPDM Dissolving process: Cut 100 parts of EPDM rubber into small pieces, add 600 parts of chloroform, and stir at 50°C for 4 hours to dissolve and obtain a uniform viscous solution.

[0027] Cooling protection: Cool the solution to 5±1℃ and stir continuously under nitrogen protection.

[0028] Epoxidation reaction: Add 15 parts of m-CPBA in 5 batches, with an interval of 10 minutes between each batch, and control the temperature within the range of 5-10℃. After all the addition is completed, react in the dark at 25±2℃ for 24 hours.

[0029] Quenching and purification: Slowly add 200 parts of 5% sodium sulfite solution, stir for 30 minutes, and test with starch-KI test paper until no blue color appears.

[0030] Separation and washing: Allow the reaction mixture to stand and separate into layers, drain the aqueous phase, and wash the organic phase repeatedly with deionized water until the aqueous phase is neutral.

[0031] Precipitation purification: The organic phase is slowly added to 1000 parts of methanol, and a white fibrous product is precipitated. After standing for 2 hours, it is filtered.

[0032] Post-treatment: The solid was washed three times with 300 parts methanol and then vacuum dried at 40°C for 48 hours.

[0033] Product processing: The dried product is crushed into particles with a particle size ≤2mm to obtain epoxidized EPDM.

[0034] Preparation Example 2: Preparation of Boric Acid-Terminated EPDM Dissolution process: 100 parts of the epoxidized EPDM obtained in Preparation Example 1 were added to the reaction vessel, and 500 parts of toluene were added. The mixture was stirred and dissolved at 60°C for 3 hours to obtain a homogeneous polymer solution. Boric acidification process: 12.4 parts of 3-aminophenylboronic acid were added to the system, the temperature was raised to 85°C, and the system was stirred for 12 hours under nitrogen protection. During the reaction, the viscosity of the system gradually increased. Termination and Cooling: After the reaction is complete, stop heating, maintain a nitrogen atmosphere, and allow it to cool naturally to room temperature for about 2 hours. Precipitation separation: Slowly pour the reaction solution into 800 parts of vigorously stirred methanol, and a light yellow fibrous product will precipitate. Continue stirring for 30 minutes and then let it stand for 1 hour. Filtration and washing: The solid product was collected by filtration and washed three times with 300 parts of methanol to thoroughly remove unreacted 3-aminophenylboronic acid and other impurities. Vacuum drying: The washed solid is vacuum dried at 60°C for 24 hours; Product processing: The dried product is crushed into particles with a particle size ≤2mm to obtain boric acid-terminated EPDM.

[0035] Preparation Example 3: Preparation of N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide Preparation of reaction materials: Add 10 parts of dopamine hydrochloride and 15.3 parts of 2-naphthoboric acid to the reaction vessel, add 300 parts of Tris-HCl buffer solution with pH=8.5, and stir until completely dissolved; Amide reaction: The reaction was carried out under continuous stirring at 25°C for 24 hours, and kept in the dark during the reaction. Product precipitation: After the reaction is complete, concentrated hydrochloric acid is slowly added to adjust the pH to 2.0. At this time, a large amount of gray precipitate is formed. Separation and purification: The precipitate is collected by filtration and repeatedly washed with pre-cooled deionized water until the filtrate is neutral; Drying treatment: The washed product was freeze-dried under vacuum to obtain a grayish-white powder product, namely N-(3,4-dihydroxyphenylethyl)-2-naphthoamide.

[0036] Example 1

[0037] An insulating material comprising two components, A and B, wherein component A comprises: 20 parts of boric acid-terminated EPDM (obtained in Preparation Example 2), 35 parts of polyolefin elastomer, 30 parts of polypropylene, 1.8 parts of N-(3,4-dihydroxyphenylethyl)-2-naphthoamide (obtained in Preparation Example 3), 0.3 parts of antioxidant 1010, and 0.3 parts of antioxidant 168; Component B contains: 60 parts LLDPE, 20 parts polypropylene, 1 part antioxidant 1010, 0.2 parts antioxidant 1024, and 0.03 parts dibutyltin dilaurate.

[0038] Preparation method: Preparation of component A: Accurately weigh each raw material according to the A component formula, and use a twin-screw extruder for melt blending and dynamic cross-linking reaction; use an automatic solid particle weighing scale for feeding, and control the measurement error within ±0.005%.

[0039] The twin-screw compressor has 14 temperature zones with temperature gradients of 150℃, 160℃, 175℃, 175℃, 175℃, 185℃, 185℃, 185℃, 190℃, 190℃, 195℃, 195℃, 195℃, 195℃, and 195℃. The main engine speed is set to 300 rpm. The material, after dynamic cross-linking via a twin-screw extruder, enters a second-stage single-screw extruder. The single-screw temperature zones are set sequentially as follows: 160℃, 185℃, 195℃, 195℃, with the neck zone at 180℃ and the head zone at 180℃. During production, temperature fluctuations in each zone are controlled within ±0.5℃, and current fluctuations within ±3%. The output is set at 350 kg / h, and material A particles are obtained through melt extrusion and underwater pelletizing.

[0040] Preparation of component B: Accurately weigh each raw material according to the B component formula and put them into a mixer. Mix the materials thoroughly and uniformly at 200℃. Then, feed the mixed material into a single-screw extruder for melt extrusion granulation. The single-screw extruder barrel has five temperature zones: 150℃, 155℃, 160℃, 165℃, and 170℃. The neck temperature is 170℃, and the head temperature is 180℃. After granulation, the material is cooled to obtain B component masterbatch, which is then sealed and packaged for later use.

[0041] Finished product preparation: The prepared A-material particles and B-material masterbatch are initially mixed in a dry nitrogen-protected silo at a weight ratio of 92:8. The mixture is then cooled to no more than 3°C above ambient temperature to obtain the final insulation product.

[0042] Example 2

[0043] The difference between this embodiment and Embodiment 1 is that, in Component A, there are 40 parts of boric acid-terminated EPDM, 25 parts of polyolefin elastomer, 25 parts of polypropylene, 2.0 parts of N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide, and 0.4 parts of antioxidant 1010; in Component B, there are 50 parts of LLDPE, 30 parts of polypropylene, 1.2 parts of antioxidant 1010, and 0.05 parts of dibutyltin dilaurate; and the weight ratio of Component A to Component B is 90:10.

[0044] Example 3

[0045] The difference between this embodiment and Embodiment 1 is that component A further includes 5 parts of 40nm boron nitride nanosheets.

[0046] Example 4

[0047] The difference between this embodiment and Example 1 is that component A contains 2.2 parts of N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide and 0.5 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; component B contains 1.5 parts of antioxidant 1010 and 0.06 parts of dibutyltin dilaurate; and the weight ratio of component A to component B is 88:12.

[0048] Example 5

[0049] The difference between this embodiment and Example 1 is that, in component A, there are 20 parts of boric acid-terminated EPDM, 40 parts of polyolefin elastomer, 35 parts of polypropylene, 1.0 part of N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide, and 0.2 parts of antioxidant 1010; in component B, there are 70 parts of LLDPE, 0.8 parts of antioxidant 1010, and 0.02 parts of dibutyltin dilaurate; and the weight ratio of component A to component B is 95:5.

[0050] Example 6

[0051] The difference between this embodiment and Embodiment 1 is that component A further includes 8 parts of ammonium polyphosphate.

[0052] Example 7

[0053] The difference between this embodiment and Embodiment 1 is that component A further includes 3 parts of nano-silica.

[0054] Example 8

[0055] The difference between this embodiment and Embodiment 1 is that component A further includes 0.5 parts of ultraviolet absorber UV-531.

[0056] Example 9

[0057] The difference between this embodiment and Example 1 is that, in component A, there are 15 parts of boric acid-terminated EPDM, 40 parts of polyolefin elastomer, 40 parts of polypropylene, 1.2 parts of N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide, and 0.2 parts of antioxidant 1010; in component B, there are 70 parts of LLDPE, 0.8 parts of antioxidant 1010, and 0.02 parts of dibutyltin dilaurate; and the weight ratio of component A to component B is 96:4.

[0058] Comparative Example 1 The difference between this comparative example and Example 1 is that component A does not contain boric acid-terminated EPDM and N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide, but instead uses 20 parts EPDM, 50 parts LLDPE, 30 parts polypropylene, and contains 1.5 parts silane coupling agent A-171 and 0.2 parts peroxide DCP; the weight ratio of component A to component B is 95:5.

[0059] Comparative Example 2 The difference between this comparative example and Example 1 is that component A does not contain boric acid-terminated EPDM and N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide.

[0060] Comparative Example 3 The difference between this comparative example and Example 1 is that 1.8 parts of ordinary phenylboronic acid were used instead of N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide in component A.

[0061] Performance testing Dielectric properties: The dielectric constant (Dk) and dielectric loss factor (Df) were measured using a dielectric spectrometer at a frequency of 1 MHz and a temperature of 23 °C.

[0062] Volume resistivity: measured according to ASTM D257 standard at 500V DC and 23℃.

[0063] Dielectric strength: According to ASTM D149 standard, in oil using a short-time method, voltage is increased at a rate of 500V / s until breakdown.

[0064] Mechanical properties: Tensile strength and elongation at break were determined according to ASTM D638.

[0065] Thermal properties: Heat distortion temperature (HDT) was determined according to ASTM D648 standard (1.82 MPa); heat aging resistance was determined by measuring the change rate of tensile strength and elongation at break after being placed in an oven at 158°C for 168 hours.

[0066] Self-healing efficiency: Standard scratches were created on the sample surface using a blade, followed by heat treatment at 80°C for 2 hours. The change in scratch width was measured using a microscope, and the repair efficiency was calculated.

[0067]

[0068] Example 1, as the basic formulation, successfully constructed a dynamic borate ester crosslinking network through the synergistic effect of boric acid-terminated EPDM and dopamine derivatives (N-CA). This system not only ensures the stable three-dimensional structure of the material but also endows it with excellent self-healing ability, while avoiding the generation of polar small molecules, thus achieving a good balance between electrical, mechanical, and functional properties.

[0069] Example 2 enhanced the crosslinking network density by increasing the proportion of boric acid-terminated EPDM. This, combined with the dopamine derivative providing more dynamic bonding sites, synergistically improved the material's self-healing efficiency and heat deformation resistance, demonstrating the targeted performance enhancement effect of key component content.

[0070] Example 3 introduced boron nitride nanosheets into the basic dynamic crosslinking system. The sheet-like boron nitride formed an effective insulating and thermally conductive barrier in the matrix. Its synergistic effect with the dense dynamic crosslinking network significantly improved the thermal conductivity and dielectric strength of the material while maintaining excellent electrical insulation properties.

[0071] Example 4 further enhanced the thermal stability of the dynamic cross-linked network by optimizing the antioxidant system and increasing the amount of dopamine derivative. The synergistic effect of the high-performance antioxidant and the more stable cross-linked network enabled the material to exhibit excellent performance retention under long-term high-temperature aging conditions.

[0072] Example 5 reduced the system viscosity by adjusting the ratio of the base resin. This formulation, while retaining the necessary dynamic crosslinking function, achieves a synergy between processing flowability and basic properties by increasing the content of flexible polymers, making it suitable for scenarios with higher processing performance requirements.

[0073] Example 6 introduces ammonium polyphosphate flame retardant into the system. This component works together with the polymer matrix to promote char formation during combustion, insulate against heat and oxygen, and expand the flame-retardant function of the insulation material, demonstrating a synergistic design of electrical properties and flame retardancy.

[0074] Example 7 shows that by adding nano-silica, its uniform dispersion and interfacial effect in the matrix, combined with the dynamic cross-linking network, synergistically enhances the mechanical strength and dielectric strength of the material, demonstrating the effective improvement of the overall performance of the material by nanofillers.

[0075] Example 8 incorporates a UV absorber into the formulation. This component effectively absorbs and dissipates UV energy, synergistically interacting with the matrix polymer to compensate for the shortcomings of organic materials in terms of weather resistance, thus expanding the material's application potential in outdoor or sun-exposed environments.

[0076] Example 9, as a cost-optimized formulation, achieves a good balance between cost and performance by adjusting the ratio of base resin to functional components while ensuring the presence of core functional components, demonstrating that the technical solution has good economic efficiency and market adaptability.

[0077] In contrast, Comparative Example 1, employing a traditional silane crosslinking system, suffers from significant shortcomings in both electrical and functional properties due to the lack of dynamic covalent bonds and molecular structure. Comparative Example 2 completely eliminates the key component for dynamic crosslinking, resulting in material performance reverting to a normal level, demonstrating the core necessity of this functional system. Comparative Example 3 shows that simply physically mixing small-molecule boric acid cannot effectively construct a stable dynamic network; instead, it may degrade performance due to compatibility issues, highlighting the importance of molecular-level structure design.

[0078] In summary, this series of embodiments has successfully developed a series of motor lead wire insulation materials that possess excellent electrical insulation properties, good thermal stability, self-healing capabilities, and adjustable processability by optimizing the core dynamic crosslinking system composed of boric acid-terminated EPDM and dopamine derivatives, and by synergistically designing it with different types of functional fillers or additives (such as boron nitride, nano-silica, antioxidants, flame retardants, etc.). This technical solution effectively solves the performance bottlenecks of traditional materials in high-end applications through the design of molecular structure and composite materials.

[0079] The embodiments described herein are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are indicated by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be included within the scope of protection of this application.

Claims

1. A low-dielectric, high-heat-resistant insulation material for motor lead wires, characterized in that, It contains component A and component B; Component A comprises the following raw materials in parts by weight: 15-40 parts of boric acid-terminated EPDM; 25-40 parts of polyolefin elastomer; 25-40 parts of polypropylene; 1.0-2.5 parts of N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide; and 0.5-1.0 parts of antioxidant. Component B comprises the following raw materials in parts by weight: 50-70 parts LLDPE; 20-30 parts polypropylene; 0.02-0.06 parts catalyst; and 0.8-1.5 parts antioxidant.

2. The low-dielectric, high-heat-resistant motor lead wire insulation material according to claim 1, characterized in that, The weight ratio of component A to component B is (88-96):(4-12).

3. The low-dielectric, high-heat-resistant motor lead wire insulation material according to claim 1, characterized in that, The boric acid-terminated EPDM is prepared by a method comprising the following steps: dissolving epoxidized EPDM in an organic solvent and reacting it with 3-aminophenylboronic acid at 60-85°C; after the reaction is completed, the EPDM is obtained by precipitation, washing and drying.

4. The low-dielectric, high-heat-resistant motor lead wire insulation material according to claim 1, characterized in that, The N-(3,4-dihydroxyphenylethyl)-2-naphthylcarboxamide is prepared by a method comprising the following steps: reacting dopamine hydrochloride with 2-naphthoboric acid in a buffer solution at pH=8.5 at 25°C, and after the reaction is completed, acidifying, precipitating, washing and drying are performed to obtain the product.

5. The low-dielectric, high-heat-resistant motor lead wire insulation material according to claim 1, characterized in that, Component A also includes a functional filler, which is at least one of boron nitride nanosheets and nano-silica, and the amount added is 1-8 parts.

6. The low-dielectric, high-heat-resistant motor lead wire insulation material according to claim 5, characterized in that, The functional filler is boron nitride nanosheets with a particle size of 30-50 nm, and the addition amount is 3-6 parts.

7. The low-dielectric, high-heat-resistant motor lead wire insulation material according to claim 1, characterized in that, Component A also includes 5-10 parts of a flame retardant, wherein the flame retardant is ammonium polyphosphate.

8. The low-dielectric, high-heat-resistant motor lead wire insulation material according to claim 1, characterized in that, The antioxidant is a compound of hindered phenolic antioxidant 1010 and phosphite antioxidant 168, with a compound weight ratio of 1:(0.5-1.5).

9. A method for preparing a low-dielectric, high-heat-resistant motor lead wire insulation material as described in any one of claims 1-8, characterized in that, Includes the following steps: Preparation of Component A: The raw materials of Component A are melt-blended and dynamically cross-linked through a twin-screw extruder, and then pelletized underwater to obtain Component A particles; Preparation of component B: The raw materials of component B are mixed, melt-extruded and granulated to obtain B masterbatch; Preparation of finished product: Mix material A particles with material B masterbatch, and then cool to obtain the insulating material.

10. A motor lead wire, characterized in that, The insulation layer is made of the low dielectric high heat resistant motor lead wire insulation material as described in any one of claims 1-8.

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