New energy vehicle cable material and preparation method thereof

Abstract

This invention relates to a new energy vehicle cable material and its preparation method, belonging to the field of automotive cable technology. The invention involves preparing a modifier, then blending the modifier with polyethylene, melt-extruding it, and subsequently subjecting it to radiation crosslinking to obtain a new energy vehicle cable outer sheath material. During combustion, the outer sheath of this invention achieves halogen-free flame retardancy through phosphorus-silicon synergy, delaying the spread of flames when the new energy vehicle cable is exposed to fire. Furthermore, the phosphate ester structure can coordinate with copper ions on the shielding layer surface, improving the bonding ability between the shielding layer and the polyethylene sheath, reducing the penetration of moisture and oxygen, and inhibiting chemical corrosion, thereby ensuring the long-term stability of the shielding performance of the new energy cable. In addition, the multiple double bonds and siloxanes in the modifier enhance the mechanical and heat resistance properties of the cable outer sheath by increasing the crosslinking density and substrate compatibility.

Description

Technical Field

[0001] This invention belongs to the field of automotive cable technology, specifically, it relates to a new energy vehicle cable material and its preparation method, and more specifically, it relates to a new energy vehicle cable outer sheath material and its preparation method. Background Technology

[0002] New energy vehicles, especially pure electric vehicles, have much higher requirements for cable performance than traditional vehicles. They contain high-voltage and high-current power cables and high-power charging cables. These cables operate in harsh environments, making it difficult for traditional materials to meet the demands.

[0003] Traditional charging cables for new energy vehicles often use materials such as polyvinyl chloride (PVC) resin as the outer sheath. This material has limited flame retardancy and moderate heat resistance, and produces large amounts of toxic fumes and corrosive gases when burned, posing significant safety hazards. Polyethylene, due to its excellent electrical insulation and chemical stability, is often chosen as the base material for cable modification. Current technologies typically use the addition of metal hydroxide flame retardants, but this suffers from insufficient flame retardant efficiency and the potential for degradation of other properties due to large addition amounts. Furthermore, new energy vehicles operate at high temperatures during charging or under high loads, making cable materials prone to thermal aging, surface embrittlement, and cracking under prolonged high temperatures, affecting the cable's electrical insulation performance and lifespan. Simultaneously, the interface gap between the copper-plastic composite shielding layer and the outer sheath cannot completely prevent the penetration of corrosive media, leading to corrosion that causes shielding failure and ultimately resulting in the failure of the entire high-voltage cable system.

[0004] Based on this, the present invention will provide a new energy vehicle cable material and its preparation method. Summary of the Invention

[0005] The purpose of this invention is to provide a new energy vehicle cable material and its preparation method, in order to solve the problems mentioned in the background art.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] A method for preparing a cable material for new energy vehicles includes the following steps:

[0008] Step 1: Add phosphoric acid, vinyl ethylene oxide and tetrahydrofuran to a three-necked flask, attach a condenser and a thermometer, turn on magnetic stirring, and react at 60-90℃ for 1-3 hours. After the reaction is completed and cooled to room temperature, remove the solvent by rotary evaporation, wash the product with saturated sodium bicarbonate solution, and then dry and elute by column chromatography to obtain the flame retardant monomer.

[0009] The second step involves adding the flame retardant monomer, silane coupling agent, potassium carbonate, acid binder, and acetonitrile to a three-necked flask, attaching a condenser and thermometer, turning on the magnetic stirrer, and reacting at 60–80°C for 8–12 hours. After the reaction is complete and the product is cooled to room temperature, the organic phase is extracted with dichloromethane and retained. The organic phase is then washed with saturated brine and deionized water, and then dried and rotary evaporated to obtain the modifier.

[0010] The third step involves mixing high-density polyethylene, low-density polyethylene, fumed silica, modifier, zinc borate, lubricant, and antioxidant, then adding the mixture to a screw extruder for melt extrusion. The mixture is then subjected to irradiation crosslinking in an electron accelerator. After crosslinking, the mixture is transferred to a vacuum oven and vacuum-treated at 80–100°C for 30–40 hours to eliminate internal stress, thus obtaining the outer sheath material for new energy vehicle cables.

[0011] Furthermore, in the first step, the mass ratio of phosphoric acid, vinyl ethylene oxide, and tetrahydrofuran is 1.5–3: 2.7–5.5: 16–20.

[0012] Furthermore, the silane coupling agent in the second step is at least one of chloropropyltriethoxysilane and chloropropyltrimethoxysilane.

[0013] Furthermore, the acid-binding agent in the second step is at least one of pyridine, 4-dimethylaminopyridine, and triethanolamine.

[0014] Furthermore, in the second step, the mass ratio of flame retardant monomer, silane coupling agent, potassium carbonate, acid binder and acetonitrile is 2.5-5.5: 5.5-9.5: 4-8: 5-10: 80-100.

[0015] Furthermore, the lubricant in the third step is at least one of polyethylene wax and oxidized polyethylene wax.

[0016] Furthermore, the temperature of melt extrusion in the third step is 150–180°C.

[0017] Furthermore, the irradiation dose in the third step of crosslinking is 70–90 kGy, and the irradiation time is 10–15 s.

[0018] Furthermore, the antioxidant in the third step is at least one of antioxidant 300, antioxidant 1010, and antioxidant 3114.

[0019] Furthermore, in the third step, the mass ratio of high-density polyethylene, low-density polyethylene, fumed silica, modifier, zinc borate, lubricant, and antioxidant is 65–75: 25–35: 15–20: 5–10: 3–5: 0.4–0.6: 0.4–0.6.

[0020] A new energy vehicle cable material is prepared by any of the above preparation steps.

[0021] The beneficial effects of this invention are:

[0022] This invention prepares an outer sheath material for new energy vehicles. During combustion, the phosphorus element promotes charring on the polymer surface, isolating heat and oxygen, while silicon forms a robust ceramic protective layer, further strengthening the char layer. The two elements work synergistically to form a highly efficient composite flame-retardant mechanism, achieving halogen-free flame retardancy. The excellent flame-retardant properties of the outer sheath can delay the spread of flames when new energy vehicle cables encounter fire, preventing the fire from rapidly expanding and causing larger safety accidents. Simultaneously, it can reduce the release of toxic and harmful gases during cable combustion, providing more escape time for vehicle occupants and reducing the risk of secondary injuries.

[0023] The new energy vehicle cable outer sheath material of this invention wraps a shielding layer composed of copper braided tape or copper foil. The phosphate ester structure in the material can coordinate with the ions on the surface of the shielding layer, improving the bonding ability between the copper braided tape and the polyethylene sheath, reducing the interface gap, reducing the penetration of moisture and oxygen, and inhibiting the occurrence of chemical corrosion. This ensures the long-term stability of the shielding performance of the new energy cable, guarantees the reliability of the electrical system of the new energy vehicle, and improves the quality and safety of the new energy vehicle.

[0024] The modifier of this invention contains multiple double bonds, which can bond with polyethylene at the molecular level after irradiation crosslinking, thereby increasing the overall crosslinking density of the material. The siloxane in the modifier improves the dispersion stability of fumed silica and avoids performance defects caused by agglomeration. The two work together to significantly improve the mechanical properties and heat resistance of the cable outer sheath, enabling new energy vehicle cables to better resist vibration, friction and compression during driving. They can also avoid aging failure caused by high temperature and external force, thereby extending the service life of the cable and reducing the risk of short circuits, ensuring stable power transmission. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments in this application specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection claimed in this application.

[0026] The raw materials used in this invention are not particularly restricted in terms of their source; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0027] Example 1

[0028] A method for preparing a cable material for new energy vehicles includes the following steps:

[0029] Step 1: Add 1.5g of phosphoric acid, 2.7g of vinyl ethylene oxide and 16g of tetrahydrofuran to a three-necked flask, attach a condenser and a thermometer, turn on magnetic stirring, and react at 60℃ for 3h. After the reaction is completed and cooled to room temperature, remove the solvent by rotary evaporation, wash the product with saturated sodium bicarbonate solution, and then dry and elute by column chromatography to obtain the flame retardant monomer.

[0030] Step 2: Add 2.5g of flame retardant monomer, 5.5g of chloropropyltriethoxysilane, 4g of potassium carbonate, 5g of pyridine and 80g of acetonitrile to a three-necked flask, attach a condenser and thermometer, turn on magnetic stirring, and react at 60℃ for 12h. After the reaction is completed and the product is cooled to room temperature, extract with dichloromethane and retain the organic phase. Then wash the organic phase with saturated brine and deionized water, and then dry and rotary evaporate to obtain the modifier.

[0031] The third step involves mixing 65g of high-density polyethylene, 35g of low-density polyethylene, 15g of fumed silica, 5g of modifier, 3g of zinc borate, 0.4g of polyethylene wax, and 0.4g of antioxidant 300, then adding the mixture to a screw extruder for melt extrusion at 150°C. The mixture is then crosslinked by irradiation at 70kGy in an electron accelerator for 10 seconds, followed by vacuum treatment at 80°C for 40 hours in a vacuum oven to eliminate internal stress, thus obtaining the outer sheath material for new energy vehicle cables.

[0032] A new energy vehicle cable material is prepared by the above-described preparation steps.

[0033] Example 2

[0034] A method for preparing a cable material for new energy vehicles includes the following steps:

[0035] Step 1: Add 2.25g of phosphoric acid, 4.1g of vinyl ethylene oxide and 18g of tetrahydrofuran to a three-necked flask, attach a condenser and a thermometer, turn on magnetic stirring, and react at 75℃ for 2h. After the reaction is completed and cooled to room temperature, remove the solvent by rotary evaporation, wash the product with saturated sodium bicarbonate solution, and then dry and elute by column chromatography to obtain the flame retardant monomer.

[0036] Step 2: Add 4g of flame retardant monomer, 7.5g of chloropropyltrimethoxysilane, 6g of potassium carbonate, 7.5g of 4-dimethylaminopyridine and 90g of acetonitrile to a three-necked flask, attach a condenser and thermometer, turn on magnetic stirring, and react at 70℃ for 10h. After the reaction is completed and the product is cooled to room temperature, extract with dichloromethane and retain the organic phase. Then wash the organic phase with saturated brine and deionized water, and then dry and rotary evaporate to obtain the modifier.

[0037] The third step involves mixing 30g of high-density polyethylene, 30g of low-density polyethylene, 17.5g of fumed silica, 7.5g of modifier, 4g of zinc borate, 0.5g of oxidized polyethylene wax, and 0.5g of antioxidant 1010, then adding the mixture to a screw extruder and melting it at 165°C. The mixture is then crosslinked by irradiation at 80kGy in an electron accelerator for 12.5s. Finally, it is placed in a vacuum oven at 90°C for 35 hours to eliminate internal stress, thus obtaining the outer sheath material for new energy vehicle cables.

[0038] A new energy vehicle cable material is prepared by the above-described preparation steps.

[0039] Example 3

[0040] A method for preparing a cable material for new energy vehicles includes the following steps:

[0041] Step 1: Add 3g of phosphoric acid, 5.5g of vinyl ethylene oxide and 20g of tetrahydrofuran to a three-necked flask, attach a condenser and a thermometer, turn on magnetic stirring, and react at 90℃ for 1h. After the reaction is completed and cooled to room temperature, remove the solvent by rotary evaporation, wash the product with saturated sodium bicarbonate solution, and then dry and elute by column chromatography to obtain the flame retardant monomer.

[0042] Step 2: Add 5.5g of flame retardant monomer, 9.5g of chloropropyltriethoxysilane, 8g of potassium carbonate, 10g of triethanolamine and 100g of acetonitrile to a three-necked flask, attach a condenser and thermometer, turn on magnetic stirring, and react at 80℃ for 8h. After the reaction is completed and the product is cooled to room temperature, extract with dichloromethane and retain the organic phase. Then wash the organic phase with saturated brine and deionized water, and then dry and rotary evaporate to obtain the modifier.

[0043] The third step involves mixing 75g of high-density polyethylene, 25g of low-density polyethylene, 20g of fumed silica, 10g of modifier, 5g of zinc borate, 0.6g of polyethylene wax, and 0.6g of antioxidant 3114, then adding the mixture to a screw extruder for melt extrusion at 180°C. The mixture is then crosslinked for 15 seconds under 90kGy irradiation in an electron accelerator. After crosslinking, it is transferred to a vacuum oven and vacuum-treated at 100°C for 30 hours to eliminate internal stress, thus obtaining the outer sheath material for new energy vehicle cables.

[0044] A new energy vehicle cable material is prepared by the above-described preparation steps.

[0045] Comparative Example 1

[0046] The difference between this comparative example and Example 2 is that the modifier is replaced with commercially available phosphate flame retardant APP, while the other raw materials and preparation steps remain unchanged.

[0047] Experimental Example 1

[0048] The outer sheaths of Examples 1-3 and Comparative Example 1 were subjected to performance tests. The tensile strength and elongation at break of the outer sheaths of each group of new energy vehicle cables were tested according to GB / T2951.21-2008 "General Test Methods for Insulation and Sheath Materials of Cables and Optical Wires". The tensile strength retention rate and elongation at break of the outer sheaths of each group of new energy vehicle cables after constant temperature treatment at 150-160℃ for 1 hour were tested according to GB / T15065-2009 "Black Polyethylene Plastic for Wires and Cables". The flame retardant rating of the outer sheaths of each group of new energy vehicle cables was tested according to GB / T19666-2019 "General Rules for Flame Retardant and Fire Resistant Wires, Cables or Optical Wires". The peel strength between the outer sheath and the metal shielding layer of each group of new energy vehicle cables was tested according to GB / T 17737.313-2018 "Coaxial Communication Cables" at a peel angle of 180° and a constant tensile speed of 90-105 mm / min. The test results are shown in Table 1.

[0049] Table 1

[0050]

[0051] As can be seen from Table 1, Examples 1-3 have higher tensile strength, elongation at break, tensile strength retention rate, elongation at break retention rate, flame retardancy rating, and peel strength compared to Comparative Example 1. This indicates that the mechanical properties, heat resistance, flame retardancy, and bonding strength with the metal shielding layer of Examples 1-3 are all superior to those of Comparative Example 1. Combined with Comparative Example 1, it can be seen that the addition of the modifier can effectively improve the mechanical properties, UV resistance, flame retardancy, and bonding strength with the metal shielding layer of the outer sheath material of new energy vehicle cables.

[0052] The present invention provides a detailed description of a new energy vehicle cable material and its preparation method. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely for the purpose of helping to understand the method and core ideas of the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including manufacturing and using any device or system, and implementing any combination method. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles. In particular, as long as there is no structural conflict, the features in the embodiments disclosed in this invention can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for preparing a cable material for new energy vehicles, characterized in that, Includes the following steps: Preparation of modifier: Flame retardant monomer is obtained by nucleophilic substitution reaction of phosphoric acid and vinyl ethylene oxide, and then modifier is obtained by nucleophilic substitution reaction of flame retardant monomer and silane coupling agent under the action of potassium carbonate and acid binder. The mass ratio of phosphoric acid to vinyl ethylene oxide is 1.5–3:2.7–5.5; The silane coupling agent is at least one of chloropropyltriethoxysilane and chloropropyltrimethoxysilane; The mass ratio of flame retardant monomer, silane coupling agent, potassium carbonate, and acid binder is 2.5–5.5: 5.5–9.5: 4–8: 5–10; Preparation of outer sheath material for new energy vehicle cables: High-density polyethylene, low-density polyethylene, fumed silica, modifier, zinc borate, lubricant, and antioxidant are blended, melt-extruded, and then irradiated and cross-linked to obtain the outer sheath material for new energy vehicle cables. The mass ratio of high-density polyethylene, low-density polyethylene, modifier, fumed silica, zinc borate, lubricant, and antioxidant is 65-75: 25-35: 15-20: 5-10: 3-5: 0.4-0.6: 0.4-0.

6.

2. The method for preparing a new energy vehicle cable material according to claim 1, characterized in that, The acid-binding agent is at least one of pyridine, 4-dimethylaminopyridine, and triethanolamine.

3. The method for preparing a new energy vehicle cable material according to claim 1, characterized in that, The lubricant is at least one of polyethylene wax and oxidized polyethylene wax, and the antioxidant is at least one of antioxidant 300, antioxidant 1010, and antioxidant 3114.

4. The method for preparing a new energy vehicle cable material according to claim 1, characterized in that, The temperature for melt extrusion is 150–180℃.

5. The method for preparing a new energy vehicle cable material according to claim 1, characterized in that, The irradiation dose in the irradiation crosslinking is 70–90 kGy, and the irradiation time is 10–15 s.

6. A cable material for new energy vehicles, characterized in that, New energy vehicle cable materials are prepared by the preparation method described in any one of claims 1 to 5.

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