New energy automobile motor controller wire harness protection material and preparation method thereof

Abstract

This application relates to the field of wiring harness protection materials, and discloses a wiring harness protection material for a new energy vehicle motor controller and its preparation method. The wiring harness protection material for a new energy vehicle motor controller is made by impregnating a base fabric layer with a polyurethane adhesive and then curing it. The polyurethane adhesive is prepared from the following raw materials in parts by weight: 70-80 parts of silane-modified polyurethane prepolymer, 22-28 parts of conductive filler, 4.5-7.5 parts of dispersant, 1-3 parts of antioxidant, 2-4 parts of curing agent, and 80-100 parts of solvent. The silane-modified polyurethane prepolymer is prepared by reacting isoflurane diisocyanate, N-(p-maleimide-phenyl)isocyanate, 3-isocyanatopropyltriethoxysilane, polyether polyol, and a catalyst, with DMF as the solvent. The wiring harness protection material of this application, when applied to a new energy vehicle motor controller, exhibits good electromagnetic shielding stability under long-term high-temperature conditions and good flexibility and bending resistance.

Description

Technical Field

[0001] This application relates to the field of wire harness protection materials, and in particular to a wire harness protection material for a new energy vehicle motor controller and its preparation method. Background Technology

[0002] As the core carrier of power transmission and signal transmission, the wiring harness of the motor controller in new energy vehicles is mainly used in key components such as the position sensor wiring harness connecting the motor stator and rotor, the connection wiring harness between the inverter and current sensor, and the transmission wiring harness between the high-voltage box and the motor controller. It also covers the high-voltage connection area between the motor controller and the power battery and charger. These wiring harnesses operate under complex conditions of high temperature, high-frequency vibration, and chemical corrosion, and must meet the power transmission requirements of a 300V-1500V high-voltage platform. Therefore, their protective materials must possess excellent electromagnetic shielding performance to prevent interference from high-voltage electromagnetic fields to the vehicle's precision electronic equipment, good flexibility to adapt to complex wiring and assembly bending requirements, and meet core performance requirements such as resistance to high and low temperatures, resistance to damp heat aging, and resistance to chemical corrosion. High-performance wiring harness protective materials can effectively block electromagnetic interference, prevent insulation breakdown, and delay material aging, thereby ensuring the signal integrity and operational stability of the motor controller, extending the service life of the wiring harness, and reducing overall vehicle safety hazards.

[0003] Currently, the manufacturing processes for protective materials for wiring harnesses of new energy vehicle motor controllers are mainly divided into three categories: First, the metal shielding process, which forms a shielding layer by weaving tin-plated copper wire or wrapping with aluminum-plastic composite tape, utilizing the conductive properties of metal to construct an electromagnetic shielding path. This process has a mature production process and stable shielding effectiveness control capabilities. Second, the polymer coating process, which directly coats the surface of the wiring harness with a resin coating containing conductive fillers, and then cures it to form a protective layer. This process has the advantages of convenient processing and controllable cost, and can be adapted to different protection needs through formula adjustments. Third, the non-woven fabric impregnation process, which selects polyester or polyether non-woven fabric as the substrate, impregnates it with an adhesive containing functional additives, and then cures it to form a protective material. Compared with the above two processes, this process, through the synergistic effect of the fiber interwoven structure and the adhesive, can give the material better mechanical strength and structural stability, and is widely used in flexible protection scenarios. Among these, polyurethane, due to its good adhesion and weather resistance, is often used as the adhesive matrix in the impregnation process, while the addition of conductive fillers such as silver powder and copper powder can improve the electromagnetic shielding function.

[0004] However, existing wire harness protection materials still have many technical defects: although non-woven fabric impregnated protective materials have a certain degree of flexibility, the multi-filler compound system is prone to problems such as increased material rigidity and decreased bending performance, and reduced electromagnetic shielding stability under long-term high temperature conditions. Summary of the Invention

[0005] To address the issues of unstable electromagnetic shielding performance and low flexibility of existing protective materials for wiring harnesses used in new energy vehicle motor controllers under long-term high-temperature conditions, this application provides a protective material for wiring harnesses of new energy vehicle motor controllers and its preparation method.

[0006] In a first aspect, this application provides a protective material for the wiring harness of a new energy vehicle motor controller, employing the following technical solution: A protective material for the wiring harness of a new energy vehicle motor controller is made by impregnating a base fabric layer with polyurethane adhesive and then curing it. The polyurethane adhesive is prepared from the following raw materials in parts by weight: 70-80 parts of silane-modified polyurethane prepolymer 22-28 parts of conductive filler Dispersant 4.5-7.5 parts 1-3 parts antioxidant 2-4 parts of curing agent Solvent: 80-100 parts; The silane-modified polyurethane prepolymer is prepared by reacting isoflurane diisocyanate, N-(p-maleimide phenyl)isocyanate, 3-isocyanopropyltriethoxysilane, polyether polyol and catalyst, with DMF as the solvent.

[0007] By adopting the above technical solution, the wire harness protection material is made by impregnating a base fabric layer with a specific component of polyurethane adhesive and then curing it. Specifically, the silane-modified polyurethane prepolymer is prepared by reacting isoflurane diisocyanate, N-(p-maleimide-phenyl)isocyanate, 3-isocyanatopropyltriethoxysilane, polyether polyol, and a catalyst. This silane-modified structure improves the dispersion uniformity of conductive fillers during the impregnation process of the polyurethane adhesive, while also enhancing the flexibility of the wire harness protection material, allowing it to maintain good physical and chemical properties under long-term high-temperature environments. The conductive filler helps to construct effective conductive pathways, improving the electromagnetic shielding performance of the wire harness protection material; the dispersant synergizes with the silane-modified polyurethane prepolymer to further ensure uniform dispersion of the components, preventing agglomeration and further improving the overall performance of the wire harness protection material; the antioxidant slows down the oxidative aging process of the wire harness protection material; the curing agent enables the polyurethane adhesive to cure and mold, giving the material the necessary strength and hardness; and the solvent DMF plays a role in diluting and improving impregnation uniformity. The wire harness protection material of this application solves the problems of unstable electromagnetic shielding performance and low flexibility of existing wire harness protection materials used in new energy vehicle motor controllers under long-term high temperature conditions. It has good electromagnetic shielding stability under long-term high temperature conditions and good flexibility and bending resistance.

[0008] Preferably, the silane-modified polyurethane prepolymer is prepared from the following raw materials in parts by weight: 30-40 parts of isoflurane diisocyanate 8-12 parts of N-(p-maleimide phenyl) isocyanate 4.5-5.8 parts of 3-isocyanate-propyltriethoxysilane 25-30 parts of polyether polyol Catalyst 0.1-0.25 parts.

[0009] By adopting the above technical solution, isoflurane diisocyanate provides certain rigidity and reactivity, while N-(p-maleimide-phenyl)isocyanate, with its steric hindrance effect of phenyl and maleimide groups, can synergistically enhance the refraction of electromagnetic waves by 3-isocyanate-propyltriethoxysilane, thereby improving electromagnetic shielding performance while imparting good flexibility and stability to the wire harness protection material. Polyether polyol, as a soft segment active material, contributes to the flexibility and high / low temperature resistance of the wire harness protection material, reacting under the action of a catalyst. The optimized dosage of each component ensures that the resulting silane-modified polyurethane prepolymer improves the electromagnetic shielding stability of the protection material under long-term high-temperature conditions, enhances its flexibility and bending resistance, thereby ensuring the signal integrity and operational stability of the motor controller, extending the service life of the wire harness, and reducing overall vehicle safety hazards.

[0010] Preferably, the polyether polyol is polytetrahydrofuran ether diol, and Mn is 400-600.

[0011] By adopting the above technical solution, polytetrahydrofuran ether diol with Mn of 400-600 is selected as the polyether polyol to participate in the reaction. Polytetrahydrofuran ether diol has good flexibility and hydrolysis resistance, which enables the prepared silane-modified polyurethane prepolymer to have good flexibility, thereby improving the flexibility and bending resistance of the wiring harness protection material for new energy vehicle motor controllers. At the same time, its hydrolysis resistance helps to improve the stability of the protection material during long-term use.

[0012] Preferably, the silane-modified polyurethane prepolymer is prepared by the following steps: Isoflurone diisocyanate, N-(p-maleimide phenyl)isocyanate, 3-isocyanatopropyltriethoxysilane, polyether polyol and catalyst were added to a reaction apparatus and the reaction was carried out under vacuum until the NCO content was 5-8%, and the reaction was stopped to obtain silane-modified polyurethane prepolymer.

[0013] By employing the above technical solution and controlling the reaction to stop at an NCO content of 5-8%, the resulting silane-modified polyurethane prepolymer can possess suitable reactivity and crosslinking density. Suitable reactivity ensures that when subsequently combined with other raw materials to form a polyurethane adhesive, it can smoothly disperse or react with conductive fillers, dispersants, and other components to form a stable protective material structure. Suitable crosslinking density allows the protective material to maintain good electromagnetic shielding stability under long-term high-temperature conditions and also imparts good flexibility and bending resistance, avoiding problems such as increased rigidity and decreased bending performance.

[0014] Preferably, the heating reaction temperature is 80-90℃.

[0015] By adopting the above technical solution and the optimal reaction temperature, the system can react stably.

[0016] Preferably, the conductive filler is composed of flake silver powder, graphene oxide, and silver-plated nickel powder in a weight ratio of 1:(0.2-0.4):(0.4-0.6); the flake silver powder has an aspect ratio ≥10 and a particle size of 50-150 nm; the graphene oxide has a particle size of 3-5 μm; and the silver content in the silver-plated nickel powder is 25-35 wt%, with a particle size of 1-3 μm.

[0017] By adopting the above technical solution, flake silver powder, graphene oxide, and silver-plated nickel powder with specific weight ratios and specifications are selected and compounded as conductive fillers. The flake silver powder has a large aspect ratio and small particle size, the graphene oxide has a moderate particle size, and the silver content and particle size of the silver-plated nickel powder are appropriate. These conductive fillers with superior specifications work together to significantly improve the electromagnetic shielding stability of the protective material, enabling it to maintain good electromagnetic shielding performance under long-term high temperature conditions. At the same time, it can be stably dispersed, improving the flexibility of the wire harness protective material.

[0018] Preferably, the dispersant is composed of methacryloyloxypropylcyclotetrasiloxane and hydroxyl polyethylene glycol acrylamide in a weight ratio of 1:(2-3).

[0019] By adopting the above technical solution, methacryloyloxypropylcyclotetrasiloxane has good dispersibility and surface activity, which can reduce the surface tension of the system and make conductive fillers uniformly dispersed in the polyurethane adhesive; hydroxyl polyethylene glycol acrylamide has hydrophilicity and a certain steric hindrance effect, which can further prevent the agglomeration of conductive fillers. The combination of the two can improve the dispersion stability of conductive fillers in polyurethane adhesive, thereby making the prepared new energy vehicle motor controller wiring harness protection material have better electromagnetic shielding stability and flexibility and bending resistance under long-term high temperature conditions.

[0020] Preferably, the curing agent is composed of isoflurane diamine and polyetheramine in a weight ratio of 1:(1-2).

[0021] By adopting the above technical solution and selecting isoflurane diamine and polyetheramine as curing agents, the polyurethane adhesive can be cured better, thereby improving the crosslinking degree and stability of the protective material.

[0022] Secondly, this application provides a method for preparing a protective material for the wiring harness of a new energy vehicle motor controller, using the following technical solution: A method for preparing a protective material for a wiring harness of a new energy vehicle motor controller includes the following steps: (1) Pretreatment of the base fabric layer: The base fabric layer is washed and dried; (2) Impregnation treatment: The base fabric layer is immersed in polyurethane adhesive and rolled repeatedly to obtain the impregnated base fabric layer; (3) Coagulation treatment: The impregnated base fabric layer is repeatedly immersed in the coagulation water bath, drained, and the protective material semi-finished product is obtained; (4) Gradient curing: The protective material semi-finished product is pre-cured at 30-40℃ for 20-30 minutes and then cured at 110-120℃ for 30-40 minutes to obtain the protective material.

[0023] By adopting the above technical solution, the water washing and drying of the base fabric layer in the pretreatment step can remove impurities and moisture from the surface of the base fabric layer, ensuring better bonding between the polyurethane adhesive and the base fabric layer during the subsequent impregnation process; the impregnation process involves immersing the base fabric layer in the polyurethane adhesive and rolling it multiple times, allowing the polyurethane adhesive to fully penetrate into the interior of the base fabric layer, ensuring uniform performance of all parts of the protective material, and producing an impregnated base fabric layer; the coagulation process involves immersing the impregnated base fabric layer in a coagulation water bath multiple times and draining it, allowing the polyurethane adhesive to initially form in the base fabric layer, removing excess solvent, and obtaining a semi-finished protective material; the gradient curing process first pre-cures at 30-40℃ for 20-30 minutes, allowing the semi-finished protective material to slowly and initially cure, reducing internal stress, and then cures at 110-120℃ for 30-40 minutes, allowing the protective material to fully cure and form a stable structure, ultimately producing a protective material for the wiring harness of the motor controller of a new energy vehicle with good electromagnetic shielding stability and flexible bending resistance under long-term high-temperature conditions.

[0024] Preferably, in step (2), the dry weight ratio controlled by roller pressing is 1:(1.4-1.5).

[0025] By adopting the above technical solution, the dry weight ratio refers to the weight ratio of the total dry weight of the wire harness protective material after impregnation and curing to the dry weight of the substrate layer before impregnation. Its core function is to quantify the amount of polyurethane adhesive adhering to the substrate layer, ensuring uniform impregnation and stable material performance. This allows the base fabric layer and the polyurethane adhesive to achieve a suitable degree of bonding. On the one hand, it ensures sufficient polyurethane adhesive adheres to the base fabric layer, guaranteeing the protective material possesses good electromagnetic shielding performance, flexibility, resistance to high and low temperatures, resistance to damp heat aging, and resistance to chemical corrosion; on the other hand, it prevents excessive adhesive from increasing material rigidity and decreasing bending performance.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. The new energy vehicle motor controller wiring harness protection material of this application is made by impregnating a base fabric layer with a polyurethane adhesive obtained by preparing a silane-modified polyurethane prepolymer, conductive filler, dispersant, antioxidant, curing agent and solvent, and then curing it. The silane-modified polyurethane prepolymer is prepared by reacting isoflurane diisocyanate, N-(p-maleimide phenyl)isocyanate, 3-isocyanate-propyltriethoxysilane, polyether polyol and catalyst. This material solves the problems of unstable electromagnetic shielding performance and low flexibility of existing new energy vehicle motor controller wiring harness protection materials under long-term high temperature conditions. It has good electromagnetic shielding stability under long-term high temperature conditions and good flexibility and bending resistance.

[0027] 2. The use of a dispersant composed of methacryloyloxypropylcyclotetrasiloxane and hydroxyl polyethylene glycol acrylamide can further improve the electromagnetic shielding performance and flexibility of wire harness protection materials.

[0028] 3. The preparation method of the new energy vehicle motor controller wiring harness protection material of this application is to obtain a new energy vehicle motor controller wiring harness protection material with good electromagnetic shielding stability and flexible bending resistance under long-term high temperature conditions by means of base fabric layer pretreatment, impregnation treatment, coagulation treatment and gradient curing. Detailed Implementation

[0029] The present application will be further described in detail below with reference to preparation examples and embodiments.

[0030] The following are some of the sources and specifications of the raw materials used in this application. The raw materials used in the preparation examples and embodiments of this application can all be obtained commercially, including but not limited to the following models and manufacturers of raw materials. Raw materials with equivalent performance can also be used: 1. Hydroxy-coated polyethylene glycol acrylamide: n = 10 - 20; 2. Polyetheramine: BASF D230; 3. Base fabric layer: 220g / m2 Nylon needle-punched fabric.

[0031] Preparation example of silane-modified polyurethane prepolymer Preparation Example 1 Preparation Example 1 discloses a silane-modified polyurethane prepolymer, which is prepared by the following steps: 3 kg of isoflurane diisocyanate, 0.8 kg of N-(p-maleimide phenyl)isocyanate, 0.58 kg of 3-isocyanatopropyltriethoxysilane, 2.5 kg of polyether polyol and 0.01 kg of catalyst were added to the reaction equipment and the temperature was raised to 80 °C under a vacuum of -0.085 MPa. The reaction was stopped when the NCO content was 8% to obtain silane-modified polyurethane prepolymer. The polyether polyol is polytetrahydrofuran ether diol with Mn of 600, and the catalyst is dibutyltin dilaurate.

[0032] Preparation Examples 2-3 The difference between Preparation Example 2-3 and Preparation Example 1 lies in the amount of raw materials used and the preparation conditions, as detailed in Table 1 below.

[0033] Table 1. Parameters for Preparation Examples 1-3

[0034] Preparation of Comparative Example 1 The difference between Comparative Example 1 and Preparation Example 1 is that N-(p-maleimide phenyl) isocyanate was replaced with isoflurane diisocyanate in equal amounts, while the rest was the same as Preparation Example 1.

[0035] Preparation of Comparative Example 2 The difference between Comparative Example 2 and Preparation Example 1 is that N-(p-maleimide phenyl) isocyanate was replaced with toluene diisocyanate in equal amounts, while the rest was the same as Preparation Example 1.

[0036] Preparation of Comparative Example 3 The difference between Comparative Example 3 and Preparation Example 3 is that 3-isocyanate-propyltriethoxysilane was replaced in equal amounts with dihydroxyl-terminated polydimethylsiloxane, Mn=2000, while the rest was the same as Preparation Example 1.

[0037] Example Example 1

[0038] Example 1 discloses a protective material for the wiring harness of a new energy vehicle motor controller, which is prepared by the following steps: (1) Pretreatment of the base fabric layer: The base fabric layer is washed and dried; (2) Impregnation treatment: The base fabric layer is immersed in polyurethane adhesive and rolled multiple times. The dry weight ratio is controlled at 1:1.4 during rolling to obtain the impregnated base fabric layer. (3) Coagulation treatment: The impregnated base fabric layer is repeatedly immersed in the coagulation water bath, drained, and the protective material semi-finished product is obtained; (4) Gradient curing: The protective material semi-finished product is pre-cured at 30℃ for 30 min and then cured at 110℃ for 40 min to obtain the protective material; The polyurethane adhesive was prepared from 7 kg of silane-modified polyurethane prepolymer obtained in Preparation Example 1, 2.2 kg of conductive filler, 0.6 kg of dispersant, 0.1 kg of antioxidant, 0.2 kg of curing agent, and 8 kg of solvent. The conductive filler consisted of flake silver powder, graphene oxide, and silver-plated nickel powder in a weight ratio of 1:0.2:0.4. The flake silver powder had an aspect ratio ≥10 and a particle size of 50-150 nm. The graphene oxide had a particle size of 3-5 μm. The silver content in the silver-plated nickel powder was 25 wt%, and the particle size was 1-3 μm. The dispersant was methacryloyloxypropylcyclotetrasiloxane. The curing agent consisted of isoflurane diamine and polyetheramine in a weight ratio of 1:1, and the solvent was DMF.

[0039] Example 2-3 The difference between Examples 2-3 and Example 1 lies in the amount of raw materials used and the preparation process parameters, as detailed in Table 2 below.

[0040] Table 2 Parameter table for Examples 1-3

[0041] Example 4

[0042] The difference between Example 4 and Example 1 is that the dispersant is composed of methacryloyloxypropylcyclotetrasiloxane and hydroxyl polyethylene glycol acrylamide in a weight ratio of 1:2, while the rest is the same as in Example 1.

[0043] Example 5

[0044] The difference between Example 5 and Example 1 is that the dispersant is composed of methacryloyloxypropylcyclotetrasiloxane and hydroxyl polyethylene glycol acrylamide in a weight ratio of 1:3, while the rest is the same as in Example 1.

[0045] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that the silane-modified polyurethane prepolymer was derived from the preparation of Comparative Example 1, while the rest is the same as Example 1.

[0046] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that the silane-modified polyurethane prepolymer was derived from the preparation of Comparative Example 2, while the rest is the same as Example 1.

[0047] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that the silane-modified polyurethane prepolymer is from the preparation of Comparative Example 3, and the others are the same as those in Example 1.

[0048] Comparative Example 4 The difference between Comparative Example 4 and Example 5 is that the dispersant is replaced with the silane-modified polyurethane prepolymer in equal amount, and the others are the same as those in Example 5.

[0049] Performance detection test The following is a performance test on the protective materials for the wire harness of the new energy vehicle motor controller prepared in Examples 1-5 and Comparative Examples 1-4: 1. Electromagnetic shielding stability test Cut a rectangular specimen of 200mm×25mm. After placing the specimen at a temperature of 125°C for 7 days, fix the specimen on the testing machine, set the bending radius to 1mm and the angle to ±90°, start the equipment, and complete 500 reciprocating bends at a temperature of 80°C. After bending, use the tubular wave coupler (TWC) method in the standard of GB / T 33012-2016 to test the electromagnetic shielding effectiveness in the 100kHz frequency band, compare it with the initial value of the shielding effectiveness before bending, and calculate the attenuation; after 500 bends, if the specimen has no cracking and the decrease in electromagnetic shielding effectiveness is ≤3dB, it is qualified; 2. Elongation at break test Refer to the test method in GB / T 1040.3-2006, the tensile speed: 50mm / min, cut dumbbell-shaped specimens, test the elongation at break (unit: %), and test and record the test results; The following are the performance test data of the protective materials for the wire harness of the new energy vehicle motor controller prepared in Examples 1-5 and Comparative Examples 1-4. For details, see Table 3 below.

[0050] Table 3 Data table of the protective materials for the wire harness of the new energy vehicle motor controller prepared in Examples 1-5 and Comparative Examples 1-4

[0051] Based on Examples 1-3 and Comparative Examples 1-3, and in conjunction with Table 3, it can be concluded that using the silane-modified polyurethane prepolymer prepared with the specific components of this application to prepare wire harness protective materials can significantly improve the flexibility and electromagnetic shielding stability of the prepared wire harness protective materials. Compared with Example 1, Comparative Examples 1-2 reduced the synergistic effect of N-(p-maleimide-phenyl)isocyanate and isoflurane diisocyanate, resulting in a significant increase in the electromagnetic shielding attenuation of the prepared wire harness protective materials, and slight cracking of the wire harness occurred. Compared with Example 1, Comparative Example 3 replaced 3-isocyanate-propyltriethoxysilane with an equal amount of hydroxyl-terminated polydimethylsiloxane. Although the elongation at break of the wire harness protective material did not change significantly, the electromagnetic shielding attenuation decreased.

[0052] Based on Examples 1, 4-5, and Comparative Example 4, and in conjunction with Table 3, it can be concluded that further optimization of the type and amount of dispersant in this application can enhance the synergistic effect with the silane-modified polyurethane prepolymer, thereby further improving the flexibility and electromagnetic shielding stability of the prepared wire harness protection material.

[0053] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A protective material for the wiring harness of a new energy vehicle motor controller, characterized in that, It is made by impregnating and curing a base fabric layer with a polyurethane adhesive, wherein the polyurethane adhesive is obtained from the following raw materials in parts by weight: 70-80 parts of silane-modified polyurethane prepolymer 22-28 parts of conductive filler Dispersant 4.5-7.5 parts 1-3 parts antioxidant 2-4 parts of curing agent Solvent: 80-100 parts; The silane-modified polyurethane prepolymer is prepared by reacting isoflurane diisocyanate, N-(p-maleimide phenyl)isocyanate, 3-isocyanopropyltriethoxysilane, polyether polyol and catalyst, with DMF as the solvent.

2. The protective material for the wiring harness of a new energy vehicle motor controller according to claim 1, characterized in that, The silane-modified polyurethane prepolymer is prepared from the following raw materials in parts by weight: 30-40 parts of isoflurane diisocyanate 8-12 parts of N-(p-maleimide phenyl) isocyanate 4.5-5.8 parts of 3-isocyanate-propyltriethoxysilane 25-30 parts of polyether polyol Catalyst 0.1-0.25 parts.

3. The protective material for the wiring harness of a new energy vehicle motor controller according to claim 2, characterized in that, The polyether polyol is polytetrahydrofuran ether diol, with Mn of 400-600.

4. A protective material for a wiring harness of a new energy vehicle motor controller according to any one of claims 1-3, characterized in that, The silane-modified polyurethane prepolymer is prepared by the following steps: Isoflurone diisocyanate, N-(p-maleimide phenyl)isocyanate, 3-isocyanatopropyltriethoxysilane, polyether polyol and catalyst were added to a reaction apparatus and the reaction was carried out under vacuum until the NCO content was 5-8%, and the reaction was stopped to obtain silane-modified polyurethane prepolymer.

5. The protective material for the wiring harness of a new energy vehicle motor controller according to claim 4, characterized in that, The temperature for the heating reaction is 80-90℃.

6. The protective material for the wiring harness of a new energy vehicle motor controller according to claim 1, characterized in that, The conductive filler is composed of flake silver powder, graphene oxide, and silver-plated nickel powder in a weight ratio of 1:(0.2-0.4):(0.4-0.6); the flake silver powder has an aspect ratio ≥10 and a particle size of 50-150 nm; the graphene oxide has a particle size of 3-5 μm; and the silver content in the silver-plated nickel powder is 25-35 wt%, with a particle size of 1-3 μm.

7. The protective material for the wiring harness of a new energy vehicle motor controller according to claim 1, characterized in that, The dispersant is composed of methacryloyloxypropylcyclotetrasiloxane and hydroxyl polyethylene glycol acrylamide in a weight ratio of 1:(2-3).

8. The protective material for the wiring harness of a new energy vehicle motor controller according to claim 1, characterized in that, The curing agent is composed of isoflurane diamine and polyetheramine in a weight ratio of 1:(1-2).

9. A method for preparing a protective material for a wiring harness of a new energy vehicle motor controller as described in any one of claims 1-8, characterized in that, Includes the following steps: (1) Pretreatment of the base fabric layer: The base fabric layer is washed and dried; (2) Impregnation treatment: The base fabric layer is immersed in polyurethane adhesive and rolled repeatedly to obtain the impregnated base fabric layer; (3) Coagulation treatment: The impregnated base fabric layer is repeatedly immersed in the coagulation water bath, drained, and the protective material semi-finished product is obtained; (4) Gradient curing: The protective material semi-finished product is pre-cured at 30-40℃ for 20-30 minutes and then cured at 110-120℃ for 30-40 minutes to obtain the protective material.

10. A method for preparing a protective material for a wiring harness of a new energy vehicle motor controller according to claim 9, characterized in that, (2) In the step, the dry weight ratio is controlled by roller pressing to be 1:(1.4-1.5).

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